29 * Packet type contexts, so that ssh2_pkt_type can correctly decode
30 * the ambiguous type numbers back into the correct type strings.
41 SSH2_PKTCTX_PUBLICKEY,
47 static const char *const ssh2_disconnect_reasons[] = {
49 "host not allowed to connect",
51 "key exchange failed",
52 "host authentication failed",
55 "service not available",
56 "protocol version not supported",
57 "host key not verifiable",
60 "too many connections",
61 "auth cancelled by user",
62 "no more auth methods available",
67 * Various remote-bug flags.
69 #define BUG_CHOKES_ON_SSH1_IGNORE 1
70 #define BUG_SSH2_HMAC 2
71 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
72 #define BUG_CHOKES_ON_RSA 8
73 #define BUG_SSH2_RSA_PADDING 16
74 #define BUG_SSH2_DERIVEKEY 32
75 #define BUG_SSH2_REKEY 64
76 #define BUG_SSH2_PK_SESSIONID 128
77 #define BUG_SSH2_MAXPKT 256
78 #define BUG_CHOKES_ON_SSH2_IGNORE 512
79 #define BUG_CHOKES_ON_WINADJ 1024
80 #define BUG_SENDS_LATE_REQUEST_REPLY 2048
81 #define BUG_SSH2_OLDGEX 4096
83 #define DH_MIN_SIZE 1024
84 #define DH_MAX_SIZE 8192
87 * Codes for terminal modes.
88 * Most of these are the same in SSH-1 and SSH-2.
89 * This list is derived from RFC 4254 and
93 const char* const mode;
95 enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
97 /* "V" prefix discarded for special characters relative to SSH specs */
98 { "INTR", 1, TTY_OP_CHAR },
99 { "QUIT", 2, TTY_OP_CHAR },
100 { "ERASE", 3, TTY_OP_CHAR },
101 { "KILL", 4, TTY_OP_CHAR },
102 { "EOF", 5, TTY_OP_CHAR },
103 { "EOL", 6, TTY_OP_CHAR },
104 { "EOL2", 7, TTY_OP_CHAR },
105 { "START", 8, TTY_OP_CHAR },
106 { "STOP", 9, TTY_OP_CHAR },
107 { "SUSP", 10, TTY_OP_CHAR },
108 { "DSUSP", 11, TTY_OP_CHAR },
109 { "REPRINT", 12, TTY_OP_CHAR },
110 { "WERASE", 13, TTY_OP_CHAR },
111 { "LNEXT", 14, TTY_OP_CHAR },
112 { "FLUSH", 15, TTY_OP_CHAR },
113 { "SWTCH", 16, TTY_OP_CHAR },
114 { "STATUS", 17, TTY_OP_CHAR },
115 { "DISCARD", 18, TTY_OP_CHAR },
116 { "IGNPAR", 30, TTY_OP_BOOL },
117 { "PARMRK", 31, TTY_OP_BOOL },
118 { "INPCK", 32, TTY_OP_BOOL },
119 { "ISTRIP", 33, TTY_OP_BOOL },
120 { "INLCR", 34, TTY_OP_BOOL },
121 { "IGNCR", 35, TTY_OP_BOOL },
122 { "ICRNL", 36, TTY_OP_BOOL },
123 { "IUCLC", 37, TTY_OP_BOOL },
124 { "IXON", 38, TTY_OP_BOOL },
125 { "IXANY", 39, TTY_OP_BOOL },
126 { "IXOFF", 40, TTY_OP_BOOL },
127 { "IMAXBEL", 41, TTY_OP_BOOL },
128 { "ISIG", 50, TTY_OP_BOOL },
129 { "ICANON", 51, TTY_OP_BOOL },
130 { "XCASE", 52, TTY_OP_BOOL },
131 { "ECHO", 53, TTY_OP_BOOL },
132 { "ECHOE", 54, TTY_OP_BOOL },
133 { "ECHOK", 55, TTY_OP_BOOL },
134 { "ECHONL", 56, TTY_OP_BOOL },
135 { "NOFLSH", 57, TTY_OP_BOOL },
136 { "TOSTOP", 58, TTY_OP_BOOL },
137 { "IEXTEN", 59, TTY_OP_BOOL },
138 { "ECHOCTL", 60, TTY_OP_BOOL },
139 { "ECHOKE", 61, TTY_OP_BOOL },
140 { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */
141 { "OPOST", 70, TTY_OP_BOOL },
142 { "OLCUC", 71, TTY_OP_BOOL },
143 { "ONLCR", 72, TTY_OP_BOOL },
144 { "OCRNL", 73, TTY_OP_BOOL },
145 { "ONOCR", 74, TTY_OP_BOOL },
146 { "ONLRET", 75, TTY_OP_BOOL },
147 { "CS7", 90, TTY_OP_BOOL },
148 { "CS8", 91, TTY_OP_BOOL },
149 { "PARENB", 92, TTY_OP_BOOL },
150 { "PARODD", 93, TTY_OP_BOOL }
153 /* Miscellaneous other tty-related constants. */
154 #define SSH_TTY_OP_END 0
155 /* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */
156 #define SSH1_TTY_OP_ISPEED 192
157 #define SSH1_TTY_OP_OSPEED 193
158 #define SSH2_TTY_OP_ISPEED 128
159 #define SSH2_TTY_OP_OSPEED 129
161 /* Helper functions for parsing tty-related config. */
162 static unsigned int ssh_tty_parse_specchar(char *s)
167 ret = ctrlparse(s, &next);
168 if (!next) ret = s[0];
170 ret = 255; /* special value meaning "don't set" */
174 static unsigned int ssh_tty_parse_boolean(char *s)
176 if (stricmp(s, "yes") == 0 ||
177 stricmp(s, "on") == 0 ||
178 stricmp(s, "true") == 0 ||
179 stricmp(s, "+") == 0)
181 else if (stricmp(s, "no") == 0 ||
182 stricmp(s, "off") == 0 ||
183 stricmp(s, "false") == 0 ||
184 stricmp(s, "-") == 0)
185 return 0; /* false */
187 return (atoi(s) != 0);
190 #define translate(x) if (type == x) return #x
191 #define translatek(x,ctx) if (type == x && (pkt_kctx == ctx)) return #x
192 #define translatea(x,ctx) if (type == x && (pkt_actx == ctx)) return #x
193 static const char *ssh1_pkt_type(int type)
195 translate(SSH1_MSG_DISCONNECT);
196 translate(SSH1_SMSG_PUBLIC_KEY);
197 translate(SSH1_CMSG_SESSION_KEY);
198 translate(SSH1_CMSG_USER);
199 translate(SSH1_CMSG_AUTH_RSA);
200 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
201 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
202 translate(SSH1_CMSG_AUTH_PASSWORD);
203 translate(SSH1_CMSG_REQUEST_PTY);
204 translate(SSH1_CMSG_WINDOW_SIZE);
205 translate(SSH1_CMSG_EXEC_SHELL);
206 translate(SSH1_CMSG_EXEC_CMD);
207 translate(SSH1_SMSG_SUCCESS);
208 translate(SSH1_SMSG_FAILURE);
209 translate(SSH1_CMSG_STDIN_DATA);
210 translate(SSH1_SMSG_STDOUT_DATA);
211 translate(SSH1_SMSG_STDERR_DATA);
212 translate(SSH1_CMSG_EOF);
213 translate(SSH1_SMSG_EXIT_STATUS);
214 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
215 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
216 translate(SSH1_MSG_CHANNEL_DATA);
217 translate(SSH1_MSG_CHANNEL_CLOSE);
218 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
219 translate(SSH1_SMSG_X11_OPEN);
220 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
221 translate(SSH1_MSG_PORT_OPEN);
222 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
223 translate(SSH1_SMSG_AGENT_OPEN);
224 translate(SSH1_MSG_IGNORE);
225 translate(SSH1_CMSG_EXIT_CONFIRMATION);
226 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
227 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
228 translate(SSH1_MSG_DEBUG);
229 translate(SSH1_CMSG_REQUEST_COMPRESSION);
230 translate(SSH1_CMSG_AUTH_TIS);
231 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
232 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
233 translate(SSH1_CMSG_AUTH_CCARD);
234 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
235 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
238 static const char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx,
241 translatea(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,SSH2_PKTCTX_GSSAPI);
242 translatea(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,SSH2_PKTCTX_GSSAPI);
243 translatea(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,SSH2_PKTCTX_GSSAPI);
244 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERROR,SSH2_PKTCTX_GSSAPI);
245 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK,SSH2_PKTCTX_GSSAPI);
246 translatea(SSH2_MSG_USERAUTH_GSSAPI_MIC, SSH2_PKTCTX_GSSAPI);
247 translate(SSH2_MSG_DISCONNECT);
248 translate(SSH2_MSG_IGNORE);
249 translate(SSH2_MSG_UNIMPLEMENTED);
250 translate(SSH2_MSG_DEBUG);
251 translate(SSH2_MSG_SERVICE_REQUEST);
252 translate(SSH2_MSG_SERVICE_ACCEPT);
253 translate(SSH2_MSG_KEXINIT);
254 translate(SSH2_MSG_NEWKEYS);
255 translatek(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
256 translatek(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
257 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST_OLD, SSH2_PKTCTX_DHGEX);
258 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
259 translatek(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
260 translatek(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
261 translatek(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
262 translatek(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX);
263 translatek(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX);
264 translatek(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX);
265 translatek(SSH2_MSG_KEX_ECDH_INIT, SSH2_PKTCTX_ECDHKEX);
266 translatek(SSH2_MSG_KEX_ECDH_REPLY, SSH2_PKTCTX_ECDHKEX);
267 translate(SSH2_MSG_USERAUTH_REQUEST);
268 translate(SSH2_MSG_USERAUTH_FAILURE);
269 translate(SSH2_MSG_USERAUTH_SUCCESS);
270 translate(SSH2_MSG_USERAUTH_BANNER);
271 translatea(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
272 translatea(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
273 translatea(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
274 translatea(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
275 translate(SSH2_MSG_GLOBAL_REQUEST);
276 translate(SSH2_MSG_REQUEST_SUCCESS);
277 translate(SSH2_MSG_REQUEST_FAILURE);
278 translate(SSH2_MSG_CHANNEL_OPEN);
279 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
280 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
281 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
282 translate(SSH2_MSG_CHANNEL_DATA);
283 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
284 translate(SSH2_MSG_CHANNEL_EOF);
285 translate(SSH2_MSG_CHANNEL_CLOSE);
286 translate(SSH2_MSG_CHANNEL_REQUEST);
287 translate(SSH2_MSG_CHANNEL_SUCCESS);
288 translate(SSH2_MSG_CHANNEL_FAILURE);
294 /* Enumeration values for fields in SSH-1 packets */
296 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
300 * Coroutine mechanics for the sillier bits of the code. If these
301 * macros look impenetrable to you, you might find it helpful to
304 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
306 * which explains the theory behind these macros.
308 * In particular, if you are getting `case expression not constant'
309 * errors when building with MS Visual Studio, this is because MS's
310 * Edit and Continue debugging feature causes their compiler to
311 * violate ANSI C. To disable Edit and Continue debugging:
313 * - right-click ssh.c in the FileView
315 * - select the C/C++ tab and the General category
316 * - under `Debug info:', select anything _other_ than `Program
317 * Database for Edit and Continue'.
319 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
320 #define crBeginState crBegin(s->crLine)
321 #define crStateP(t, v) \
323 if (!(v)) { s = (v) = snew(struct t); s->crLine = 0; } \
325 #define crState(t) crStateP(t, ssh->t)
326 #define crFinish(z) } *crLine = 0; return (z); }
327 #define crFinishV } *crLine = 0; return; }
328 #define crFinishFree(z) } sfree(s); return (z); }
329 #define crFinishFreeV } sfree(s); return; }
330 #define crReturn(z) \
332 *crLine =__LINE__; return (z); case __LINE__:;\
336 *crLine=__LINE__; return; case __LINE__:;\
338 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
339 #define crStopV do{ *crLine = 0; return; }while(0)
340 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
341 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
345 static struct Packet *ssh1_pkt_init(int pkt_type);
346 static struct Packet *ssh2_pkt_init(int pkt_type);
347 static void ssh_pkt_ensure(struct Packet *, int length);
348 static void ssh_pkt_adddata(struct Packet *, const void *data, int len);
349 static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
350 static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
351 static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
352 static void ssh_pkt_addstring_start(struct Packet *);
353 static void ssh_pkt_addstring_str(struct Packet *, const char *data);
354 static void ssh_pkt_addstring_data(struct Packet *, const char *data, int len);
355 static void ssh_pkt_addstring(struct Packet *, const char *data);
356 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
357 static void ssh1_pkt_addmp(struct Packet *, Bignum b);
358 static void ssh2_pkt_addmp(struct Packet *, Bignum b);
359 static int ssh2_pkt_construct(Ssh, struct Packet *);
360 static void ssh2_pkt_send(Ssh, struct Packet *);
361 static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
362 static int do_ssh1_login(Ssh ssh, const unsigned char *in, int inlen,
363 struct Packet *pktin);
364 static void do_ssh2_authconn(Ssh ssh, const unsigned char *in, int inlen,
365 struct Packet *pktin);
366 static void ssh2_channel_check_close(struct ssh_channel *c);
367 static void ssh_channel_destroy(struct ssh_channel *c);
368 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin);
371 * Buffer management constants. There are several of these for
372 * various different purposes:
374 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
375 * on a local data stream before we throttle the whole SSH
376 * connection (in SSH-1 only). Throttling the whole connection is
377 * pretty drastic so we set this high in the hope it won't
380 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
381 * on the SSH connection itself before we defensively throttle
382 * _all_ local data streams. This is pretty drastic too (though
383 * thankfully unlikely in SSH-2 since the window mechanism should
384 * ensure that the server never has any need to throttle its end
385 * of the connection), so we set this high as well.
387 * - OUR_V2_WINSIZE is the default window size we present on SSH-2
390 * - OUR_V2_BIGWIN is the window size we advertise for the only
391 * channel in a simple connection. It must be <= INT_MAX.
393 * - OUR_V2_MAXPKT is the official "maximum packet size" we send
394 * to the remote side. This actually has nothing to do with the
395 * size of the _packet_, but is instead a limit on the amount
396 * of data we're willing to receive in a single SSH2 channel
399 * - OUR_V2_PACKETLIMIT is actually the maximum size of SSH
400 * _packet_ we're prepared to cope with. It must be a multiple
401 * of the cipher block size, and must be at least 35000.
404 #define SSH1_BUFFER_LIMIT 32768
405 #define SSH_MAX_BACKLOG 32768
406 #define OUR_V2_WINSIZE 16384
407 #define OUR_V2_BIGWIN 0x7fffffff
408 #define OUR_V2_MAXPKT 0x4000UL
409 #define OUR_V2_PACKETLIMIT 0x9000UL
411 struct ssh_signkey_with_user_pref_id {
412 const struct ssh_signkey *alg;
415 const static struct ssh_signkey_with_user_pref_id hostkey_algs[] = {
416 { &ssh_ecdsa_ed25519, HK_ED25519 },
417 { &ssh_ecdsa_nistp256, HK_ECDSA },
418 { &ssh_ecdsa_nistp384, HK_ECDSA },
419 { &ssh_ecdsa_nistp521, HK_ECDSA },
420 { &ssh_dss, HK_DSA },
421 { &ssh_rsa, HK_RSA },
424 const static struct ssh_mac *const macs[] = {
425 &ssh_hmac_sha256, &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
427 const static struct ssh_mac *const buggymacs[] = {
428 &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
431 static void *ssh_comp_none_init(void)
435 static void ssh_comp_none_cleanup(void *handle)
438 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
439 unsigned char **outblock, int *outlen)
443 static int ssh_comp_none_disable(void *handle)
447 const static struct ssh_compress ssh_comp_none = {
449 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
450 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
451 ssh_comp_none_disable, NULL
453 extern const struct ssh_compress ssh_zlib;
454 const static struct ssh_compress *const compressions[] = {
455 &ssh_zlib, &ssh_comp_none
458 enum { /* channel types */
463 CHAN_SOCKDATA_DORMANT, /* one the remote hasn't confirmed */
465 * CHAN_SHARING indicates a channel which is tracked here on
466 * behalf of a connection-sharing downstream. We do almost nothing
467 * with these channels ourselves: all messages relating to them
468 * get thrown straight to sshshare.c and passed on almost
469 * unmodified to downstream.
473 * CHAN_ZOMBIE is used to indicate a channel for which we've
474 * already destroyed the local data source: for instance, if a
475 * forwarded port experiences a socket error on the local side, we
476 * immediately destroy its local socket and turn the SSH channel
482 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
483 typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
484 typedef void (*cchandler_fn_t)(struct ssh_channel *, struct Packet *, void *);
487 * Each channel has a queue of outstanding CHANNEL_REQUESTS and their
490 struct outstanding_channel_request {
491 cchandler_fn_t handler;
493 struct outstanding_channel_request *next;
497 * 2-3-4 tree storing channels.
500 Ssh ssh; /* pointer back to main context */
501 unsigned remoteid, localid;
503 /* True if we opened this channel but server hasn't confirmed. */
506 * In SSH-1, this value contains four bits:
508 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
509 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
510 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
511 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
513 * A channel is completely finished with when all four bits are set.
515 * In SSH-2, the four bits mean:
517 * 1 We have sent SSH2_MSG_CHANNEL_EOF.
518 * 2 We have sent SSH2_MSG_CHANNEL_CLOSE.
519 * 4 We have received SSH2_MSG_CHANNEL_EOF.
520 * 8 We have received SSH2_MSG_CHANNEL_CLOSE.
522 * A channel is completely finished with when we have both sent
523 * and received CLOSE.
525 * The symbolic constants below use the SSH-2 terminology, which
526 * is a bit confusing in SSH-1, but we have to use _something_.
528 #define CLOSES_SENT_EOF 1
529 #define CLOSES_SENT_CLOSE 2
530 #define CLOSES_RCVD_EOF 4
531 #define CLOSES_RCVD_CLOSE 8
535 * This flag indicates that an EOF is pending on the outgoing side
536 * of the channel: that is, wherever we're getting the data for
537 * this channel has sent us some data followed by EOF. We can't
538 * actually send the EOF until we've finished sending the data, so
539 * we set this flag instead to remind us to do so once our buffer
545 * True if this channel is causing the underlying connection to be
550 struct ssh2_data_channel {
552 unsigned remwindow, remmaxpkt;
553 /* locwindow is signed so we can cope with excess data. */
554 int locwindow, locmaxwin;
556 * remlocwin is the amount of local window that we think
557 * the remote end had available to it after it sent the
558 * last data packet or window adjust ack.
562 * These store the list of channel requests that haven't
565 struct outstanding_channel_request *chanreq_head, *chanreq_tail;
566 enum { THROTTLED, UNTHROTTLING, UNTHROTTLED } throttle_state;
570 struct ssh_agent_channel {
571 unsigned char *message;
572 unsigned char msglen[4];
573 unsigned lensofar, totallen;
574 int outstanding_requests;
576 struct ssh_x11_channel {
577 struct X11Connection *xconn;
580 struct ssh_pfd_channel {
581 struct PortForwarding *pf;
583 struct ssh_sharing_channel {
590 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
591 * use this structure in different ways, reflecting SSH-2's
592 * altogether saner approach to port forwarding.
594 * In SSH-1, you arrange a remote forwarding by sending the server
595 * the remote port number, and the local destination host:port.
596 * When a connection comes in, the server sends you back that
597 * host:port pair, and you connect to it. This is a ready-made
598 * security hole if you're not on the ball: a malicious server
599 * could send you back _any_ host:port pair, so if you trustingly
600 * connect to the address it gives you then you've just opened the
601 * entire inside of your corporate network just by connecting
602 * through it to a dodgy SSH server. Hence, we must store a list of
603 * host:port pairs we _are_ trying to forward to, and reject a
604 * connection request from the server if it's not in the list.
606 * In SSH-2, each side of the connection minds its own business and
607 * doesn't send unnecessary information to the other. You arrange a
608 * remote forwarding by sending the server just the remote port
609 * number. When a connection comes in, the server tells you which
610 * of its ports was connected to; and _you_ have to remember what
611 * local host:port pair went with that port number.
613 * Hence, in SSH-1 this structure is indexed by destination
614 * host:port pair, whereas in SSH-2 it is indexed by source port.
616 struct ssh_portfwd; /* forward declaration */
618 struct ssh_rportfwd {
619 unsigned sport, dport;
623 struct ssh_portfwd *pfrec;
626 static void free_rportfwd(struct ssh_rportfwd *pf)
629 sfree(pf->sportdesc);
637 * Separately to the rportfwd tree (which is for looking up port
638 * open requests from the server), a tree of _these_ structures is
639 * used to keep track of all the currently open port forwardings,
640 * so that we can reconfigure in mid-session if the user requests
644 enum { DESTROY, KEEP, CREATE } status;
646 unsigned sport, dport;
649 struct ssh_rportfwd *remote;
651 struct PortListener *local;
653 #define free_portfwd(pf) ( \
654 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
655 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
658 long length; /* length of packet: see below */
659 long forcepad; /* SSH-2: force padding to at least this length */
660 int type; /* only used for incoming packets */
661 unsigned long sequence; /* SSH-2 incoming sequence number */
662 unsigned char *data; /* allocated storage */
663 unsigned char *body; /* offset of payload within `data' */
664 long savedpos; /* dual-purpose saved packet position: see below */
665 long maxlen; /* amount of storage allocated for `data' */
666 long encrypted_len; /* for SSH-2 total-size counting */
669 * A note on the 'length' and 'savedpos' fields above.
671 * Incoming packets are set up so that pkt->length is measured
672 * relative to pkt->body, which itself points to a few bytes after
673 * pkt->data (skipping some uninteresting header fields including
674 * the packet type code). The ssh_pkt_get* functions all expect
675 * this setup, and they also use pkt->savedpos to indicate how far
676 * through the packet being decoded they've got - and that, too,
677 * is an offset from pkt->body rather than pkt->data.
679 * During construction of an outgoing packet, however, pkt->length
680 * is measured relative to the base pointer pkt->data, and
681 * pkt->body is not really used for anything until the packet is
682 * ready for sending. In this mode, pkt->savedpos is reused as a
683 * temporary variable by the addstring functions, which write out
684 * a string length field and then keep going back and updating it
685 * as more data is appended to the subsequent string data field;
686 * pkt->savedpos stores the offset (again relative to pkt->data)
687 * of the start of the string data field.
690 /* Extra metadata used in SSH packet logging mode, allowing us to
691 * log in the packet header line that the packet came from a
692 * connection-sharing downstream and what if anything unusual was
693 * done to it. The additional_log_text field is expected to be a
694 * static string - it will not be freed. */
695 unsigned downstream_id;
696 const char *additional_log_text;
699 static void ssh1_protocol(Ssh ssh, const void *vin, int inlen,
700 struct Packet *pktin);
701 static void ssh2_protocol(Ssh ssh, const void *vin, int inlen,
702 struct Packet *pktin);
703 static void ssh2_bare_connection_protocol(Ssh ssh, const void *vin, int inlen,
704 struct Packet *pktin);
705 static void ssh1_protocol_setup(Ssh ssh);
706 static void ssh2_protocol_setup(Ssh ssh);
707 static void ssh2_bare_connection_protocol_setup(Ssh ssh);
708 static void ssh_size(void *handle, int width, int height);
709 static void ssh_special(void *handle, Telnet_Special);
710 static int ssh2_try_send(struct ssh_channel *c);
711 static int ssh_send_channel_data(struct ssh_channel *c,
712 const char *buf, int len);
713 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
714 static void ssh2_set_window(struct ssh_channel *c, int newwin);
715 static int ssh_sendbuffer(void *handle);
716 static int ssh_do_close(Ssh ssh, int notify_exit);
717 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
718 static int ssh2_pkt_getbool(struct Packet *pkt);
719 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
720 static void ssh2_timer(void *ctx, unsigned long now);
721 static void do_ssh2_transport(Ssh ssh, const void *vin, int inlen,
722 struct Packet *pktin);
723 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin);
725 struct rdpkt1_state_tag {
726 long len, pad, biglen, to_read;
727 unsigned long realcrc, gotcrc;
731 struct Packet *pktin;
734 struct rdpkt2_state_tag {
735 long len, pad, payload, packetlen, maclen;
738 unsigned long incoming_sequence;
739 struct Packet *pktin;
742 struct rdpkt2_bare_state_tag {
746 unsigned long incoming_sequence;
747 struct Packet *pktin;
750 struct queued_handler;
751 struct queued_handler {
753 chandler_fn_t handler;
755 struct queued_handler *next;
759 const struct plug_function_table *fn;
760 /* the above field _must_ be first in the structure */
770 unsigned char session_key[32];
772 int v1_remote_protoflags;
773 int v1_local_protoflags;
774 int agentfwd_enabled;
777 const struct ssh_cipher *cipher;
780 const struct ssh2_cipher *cscipher, *sccipher;
781 void *cs_cipher_ctx, *sc_cipher_ctx;
782 const struct ssh_mac *csmac, *scmac;
783 int csmac_etm, scmac_etm;
784 void *cs_mac_ctx, *sc_mac_ctx;
785 const struct ssh_compress *cscomp, *sccomp;
786 void *cs_comp_ctx, *sc_comp_ctx;
787 const struct ssh_kex *kex;
788 const struct ssh_signkey *hostkey;
789 char *hostkey_str; /* string representation, for easy checking in rekeys */
790 unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN];
791 int v2_session_id_len;
795 int attempting_connshare;
801 int echoing, editing;
806 int ospeed, ispeed; /* temporaries */
807 int term_width, term_height;
809 tree234 *channels; /* indexed by local id */
810 struct ssh_channel *mainchan; /* primary session channel */
811 int ncmode; /* is primary channel direct-tcpip? */
816 tree234 *rportfwds, *portfwds;
820 SSH_STATE_BEFORE_SIZE,
826 int size_needed, eof_needed;
827 int sent_console_eof;
828 int got_pty; /* affects EOF behaviour on main channel */
830 struct Packet **queue;
831 int queuelen, queuesize;
833 unsigned char *deferred_send_data;
834 int deferred_len, deferred_size;
837 * Gross hack: pscp will try to start SFTP but fall back to
838 * scp1 if that fails. This variable is the means by which
839 * scp.c can reach into the SSH code and find out which one it
844 bufchain banner; /* accumulates banners during do_ssh2_authconn */
849 struct X11Display *x11disp;
850 struct X11FakeAuth *x11auth;
851 tree234 *x11authtree;
854 int conn_throttle_count;
857 int v1_stdout_throttling;
858 unsigned long v2_outgoing_sequence;
860 int ssh1_rdpkt_crstate;
861 int ssh2_rdpkt_crstate;
862 int ssh2_bare_rdpkt_crstate;
863 int ssh_gotdata_crstate;
864 int do_ssh1_connection_crstate;
866 void *do_ssh_init_state;
867 void *do_ssh1_login_state;
868 void *do_ssh2_transport_state;
869 void *do_ssh2_authconn_state;
870 void *do_ssh_connection_init_state;
872 struct rdpkt1_state_tag rdpkt1_state;
873 struct rdpkt2_state_tag rdpkt2_state;
874 struct rdpkt2_bare_state_tag rdpkt2_bare_state;
876 /* SSH-1 and SSH-2 use this for different things, but both use it */
877 int protocol_initial_phase_done;
879 void (*protocol) (Ssh ssh, const void *vin, int inlen,
881 struct Packet *(*s_rdpkt) (Ssh ssh, const unsigned char **data,
883 int (*do_ssh_init)(Ssh ssh, unsigned char c);
886 * We maintain our own copy of a Conf structure here. That way,
887 * when we're passed a new one for reconfiguration, we can check
888 * the differences and potentially reconfigure port forwardings
889 * etc in mid-session.
894 * Values cached out of conf so as to avoid the tree234 lookup
895 * cost every time they're used.
900 * Dynamically allocated username string created during SSH
901 * login. Stored in here rather than in the coroutine state so
902 * that it'll be reliably freed if we shut down the SSH session
903 * at some unexpected moment.
908 * Used to transfer data back from async callbacks.
910 void *agent_response;
911 int agent_response_len;
915 * The SSH connection can be set as `frozen', meaning we are
916 * not currently accepting incoming data from the network. This
917 * is slightly more serious than setting the _socket_ as
918 * frozen, because we may already have had data passed to us
919 * from the network which we need to delay processing until
920 * after the freeze is lifted, so we also need a bufchain to
924 bufchain queued_incoming_data;
927 * Dispatch table for packet types that we may have to deal
930 handler_fn_t packet_dispatch[256];
933 * Queues of one-off handler functions for success/failure
934 * indications from a request.
936 struct queued_handler *qhead, *qtail;
937 handler_fn_t q_saved_handler1, q_saved_handler2;
940 * This module deals with sending keepalives.
945 * Track incoming and outgoing data sizes and time, for
948 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
949 unsigned long max_data_size;
951 unsigned long next_rekey, last_rekey;
952 const char *deferred_rekey_reason;
955 * Fully qualified host name, which we need if doing GSSAPI.
961 * GSSAPI libraries for this session.
963 struct ssh_gss_liblist *gsslibs;
967 * The last list returned from get_specials.
969 struct telnet_special *specials;
972 * List of host key algorithms for which we _don't_ have a stored
973 * host key. These are indices into the main hostkey_algs[] array
975 int uncert_hostkeys[lenof(hostkey_algs)];
976 int n_uncert_hostkeys;
979 * Flag indicating that the current rekey is intended to finish
980 * with a newly cross-certified host key.
982 int cross_certifying;
985 #define logevent(s) logevent(ssh->frontend, s)
987 /* logevent, only printf-formatted. */
988 static void logeventf(Ssh ssh, const char *fmt, ...)
994 buf = dupvprintf(fmt, ap);
1000 static void bomb_out(Ssh ssh, char *text)
1002 ssh_do_close(ssh, FALSE);
1004 connection_fatal(ssh->frontend, "%s", text);
1008 #define bombout(msg) bomb_out(ssh, dupprintf msg)
1010 /* Helper function for common bits of parsing ttymodes. */
1011 static void parse_ttymodes(Ssh ssh,
1012 void (*do_mode)(void *data, char *mode, char *val),
1017 for (val = conf_get_str_strs(ssh->conf, CONF_ttymodes, NULL, &key);
1019 val = conf_get_str_strs(ssh->conf, CONF_ttymodes, key, &key)) {
1021 * val[0] is either 'V', indicating that an explicit value
1022 * follows it, or 'A' indicating that we should pass the
1023 * value through from the local environment via get_ttymode.
1025 if (val[0] == 'A') {
1026 val = get_ttymode(ssh->frontend, key);
1028 do_mode(data, key, val);
1032 do_mode(data, key, val + 1); /* skip the 'V' */
1036 static int ssh_channelcmp(void *av, void *bv)
1038 struct ssh_channel *a = (struct ssh_channel *) av;
1039 struct ssh_channel *b = (struct ssh_channel *) bv;
1040 if (a->localid < b->localid)
1042 if (a->localid > b->localid)
1046 static int ssh_channelfind(void *av, void *bv)
1048 unsigned *a = (unsigned *) av;
1049 struct ssh_channel *b = (struct ssh_channel *) bv;
1050 if (*a < b->localid)
1052 if (*a > b->localid)
1057 static int ssh_rportcmp_ssh1(void *av, void *bv)
1059 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1060 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1062 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
1063 return i < 0 ? -1 : +1;
1064 if (a->dport > b->dport)
1066 if (a->dport < b->dport)
1071 static int ssh_rportcmp_ssh2(void *av, void *bv)
1073 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1074 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1076 if ( (i = strcmp(a->shost, b->shost)) != 0)
1077 return i < 0 ? -1 : +1;
1078 if (a->sport > b->sport)
1080 if (a->sport < b->sport)
1086 * Special form of strcmp which can cope with NULL inputs. NULL is
1087 * defined to sort before even the empty string.
1089 static int nullstrcmp(const char *a, const char *b)
1091 if (a == NULL && b == NULL)
1097 return strcmp(a, b);
1100 static int ssh_portcmp(void *av, void *bv)
1102 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
1103 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
1105 if (a->type > b->type)
1107 if (a->type < b->type)
1109 if (a->addressfamily > b->addressfamily)
1111 if (a->addressfamily < b->addressfamily)
1113 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
1114 return i < 0 ? -1 : +1;
1115 if (a->sport > b->sport)
1117 if (a->sport < b->sport)
1119 if (a->type != 'D') {
1120 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
1121 return i < 0 ? -1 : +1;
1122 if (a->dport > b->dport)
1124 if (a->dport < b->dport)
1130 static int alloc_channel_id(Ssh ssh)
1132 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1133 unsigned low, high, mid;
1135 struct ssh_channel *c;
1138 * First-fit allocation of channel numbers: always pick the
1139 * lowest unused one. To do this, binary-search using the
1140 * counted B-tree to find the largest channel ID which is in a
1141 * contiguous sequence from the beginning. (Precisely
1142 * everything in that sequence must have ID equal to its tree
1143 * index plus CHANNEL_NUMBER_OFFSET.)
1145 tsize = count234(ssh->channels);
1149 while (high - low > 1) {
1150 mid = (high + low) / 2;
1151 c = index234(ssh->channels, mid);
1152 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1153 low = mid; /* this one is fine */
1155 high = mid; /* this one is past it */
1158 * Now low points to either -1, or the tree index of the
1159 * largest ID in the initial sequence.
1162 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
1163 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
1165 return low + 1 + CHANNEL_NUMBER_OFFSET;
1168 static void c_write_stderr(int trusted, const char *buf, int len)
1171 for (i = 0; i < len; i++)
1172 if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60)))
1173 fputc(buf[i], stderr);
1176 static void c_write(Ssh ssh, const char *buf, int len)
1178 if (flags & FLAG_STDERR)
1179 c_write_stderr(1, buf, len);
1181 from_backend(ssh->frontend, 1, buf, len);
1184 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
1186 if (flags & FLAG_STDERR)
1187 c_write_stderr(0, buf, len);
1189 from_backend_untrusted(ssh->frontend, buf, len);
1192 static void c_write_str(Ssh ssh, const char *buf)
1194 c_write(ssh, buf, strlen(buf));
1197 static void ssh_free_packet(struct Packet *pkt)
1202 static struct Packet *ssh_new_packet(void)
1204 struct Packet *pkt = snew(struct Packet);
1206 pkt->body = pkt->data = NULL;
1212 static void ssh1_log_incoming_packet(Ssh ssh, struct Packet *pkt)
1215 struct logblank_t blanks[4];
1221 if (ssh->logomitdata &&
1222 (pkt->type == SSH1_SMSG_STDOUT_DATA ||
1223 pkt->type == SSH1_SMSG_STDERR_DATA ||
1224 pkt->type == SSH1_MSG_CHANNEL_DATA)) {
1225 /* "Session data" packets - omit the data string. */
1226 if (pkt->type == SSH1_MSG_CHANNEL_DATA)
1227 ssh_pkt_getuint32(pkt); /* skip channel id */
1228 blanks[nblanks].offset = pkt->savedpos + 4;
1229 blanks[nblanks].type = PKTLOG_OMIT;
1230 ssh_pkt_getstring(pkt, &str, &slen);
1232 blanks[nblanks].len = slen;
1236 log_packet(ssh->logctx, PKT_INCOMING, pkt->type,
1237 ssh1_pkt_type(pkt->type),
1238 pkt->body, pkt->length, nblanks, blanks, NULL,
1242 static void ssh1_log_outgoing_packet(Ssh ssh, struct Packet *pkt)
1245 struct logblank_t blanks[4];
1250 * For outgoing packets, pkt->length represents the length of the
1251 * whole packet starting at pkt->data (including some header), and
1252 * pkt->body refers to the point within that where the log-worthy
1253 * payload begins. However, incoming packets expect pkt->length to
1254 * represent only the payload length (that is, it's measured from
1255 * pkt->body not from pkt->data). Temporarily adjust our outgoing
1256 * packet to conform to the incoming-packet semantics, so that we
1257 * can analyse it with the ssh_pkt_get functions.
1259 pkt->length -= (pkt->body - pkt->data);
1262 if (ssh->logomitdata &&
1263 (pkt->type == SSH1_CMSG_STDIN_DATA ||
1264 pkt->type == SSH1_MSG_CHANNEL_DATA)) {
1265 /* "Session data" packets - omit the data string. */
1266 if (pkt->type == SSH1_MSG_CHANNEL_DATA)
1267 ssh_pkt_getuint32(pkt); /* skip channel id */
1268 blanks[nblanks].offset = pkt->savedpos + 4;
1269 blanks[nblanks].type = PKTLOG_OMIT;
1270 ssh_pkt_getstring(pkt, &str, &slen);
1272 blanks[nblanks].len = slen;
1277 if ((pkt->type == SSH1_CMSG_AUTH_PASSWORD ||
1278 pkt->type == SSH1_CMSG_AUTH_TIS_RESPONSE ||
1279 pkt->type == SSH1_CMSG_AUTH_CCARD_RESPONSE) &&
1280 conf_get_int(ssh->conf, CONF_logomitpass)) {
1281 /* If this is a password or similar packet, blank the password(s). */
1282 blanks[nblanks].offset = 0;
1283 blanks[nblanks].len = pkt->length;
1284 blanks[nblanks].type = PKTLOG_BLANK;
1286 } else if (pkt->type == SSH1_CMSG_X11_REQUEST_FORWARDING &&
1287 conf_get_int(ssh->conf, CONF_logomitpass)) {
1289 * If this is an X forwarding request packet, blank the fake
1292 * Note that while we blank the X authentication data here, we
1293 * don't take any special action to blank the start of an X11
1294 * channel, so using MIT-MAGIC-COOKIE-1 and actually opening
1295 * an X connection without having session blanking enabled is
1296 * likely to leak your cookie into the log.
1299 ssh_pkt_getstring(pkt, &str, &slen);
1300 blanks[nblanks].offset = pkt->savedpos;
1301 blanks[nblanks].type = PKTLOG_BLANK;
1302 ssh_pkt_getstring(pkt, &str, &slen);
1304 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1309 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1310 ssh1_pkt_type(pkt->data[12]),
1311 pkt->body, pkt->length,
1312 nblanks, blanks, NULL, 0, NULL);
1315 * Undo the above adjustment of pkt->length, to put the packet
1316 * back in the state we found it.
1318 pkt->length += (pkt->body - pkt->data);
1322 * Collect incoming data in the incoming packet buffer.
1323 * Decipher and verify the packet when it is completely read.
1324 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1325 * Update the *data and *datalen variables.
1326 * Return a Packet structure when a packet is completed.
1328 static struct Packet *ssh1_rdpkt(Ssh ssh, const unsigned char **data,
1331 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
1333 crBegin(ssh->ssh1_rdpkt_crstate);
1335 st->pktin = ssh_new_packet();
1337 st->pktin->type = 0;
1338 st->pktin->length = 0;
1340 for (st->i = st->len = 0; st->i < 4; st->i++) {
1341 while ((*datalen) == 0)
1343 st->len = (st->len << 8) + **data;
1344 (*data)++, (*datalen)--;
1347 st->pad = 8 - (st->len % 8);
1348 st->biglen = st->len + st->pad;
1349 st->pktin->length = st->len - 5;
1351 if (st->biglen < 0) {
1352 bombout(("Extremely large packet length from server suggests"
1353 " data stream corruption"));
1354 ssh_free_packet(st->pktin);
1358 st->pktin->maxlen = st->biglen;
1359 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1361 st->to_read = st->biglen;
1362 st->p = st->pktin->data;
1363 while (st->to_read > 0) {
1364 st->chunk = st->to_read;
1365 while ((*datalen) == 0)
1367 if (st->chunk > (*datalen))
1368 st->chunk = (*datalen);
1369 memcpy(st->p, *data, st->chunk);
1371 *datalen -= st->chunk;
1373 st->to_read -= st->chunk;
1376 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1377 st->biglen, NULL)) {
1378 bombout(("Network attack (CRC compensation) detected!"));
1379 ssh_free_packet(st->pktin);
1384 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1386 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1387 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1388 if (st->gotcrc != st->realcrc) {
1389 bombout(("Incorrect CRC received on packet"));
1390 ssh_free_packet(st->pktin);
1394 st->pktin->body = st->pktin->data + st->pad + 1;
1396 if (ssh->v1_compressing) {
1397 unsigned char *decompblk;
1399 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1400 st->pktin->body - 1, st->pktin->length + 1,
1401 &decompblk, &decomplen)) {
1402 bombout(("Zlib decompression encountered invalid data"));
1403 ssh_free_packet(st->pktin);
1407 if (st->pktin->maxlen < st->pad + decomplen) {
1408 st->pktin->maxlen = st->pad + decomplen;
1409 st->pktin->data = sresize(st->pktin->data,
1410 st->pktin->maxlen + APIEXTRA,
1412 st->pktin->body = st->pktin->data + st->pad + 1;
1415 memcpy(st->pktin->body - 1, decompblk, decomplen);
1417 st->pktin->length = decomplen - 1;
1420 st->pktin->type = st->pktin->body[-1];
1423 * Now pktin->body and pktin->length identify the semantic content
1424 * of the packet, excluding the initial type byte.
1428 ssh1_log_incoming_packet(ssh, st->pktin);
1430 st->pktin->savedpos = 0;
1432 crFinish(st->pktin);
1435 static void ssh2_log_incoming_packet(Ssh ssh, struct Packet *pkt)
1438 struct logblank_t blanks[4];
1444 if (ssh->logomitdata &&
1445 (pkt->type == SSH2_MSG_CHANNEL_DATA ||
1446 pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)) {
1447 /* "Session data" packets - omit the data string. */
1448 ssh_pkt_getuint32(pkt); /* skip channel id */
1449 if (pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)
1450 ssh_pkt_getuint32(pkt); /* skip extended data type */
1451 blanks[nblanks].offset = pkt->savedpos + 4;
1452 blanks[nblanks].type = PKTLOG_OMIT;
1453 ssh_pkt_getstring(pkt, &str, &slen);
1455 blanks[nblanks].len = slen;
1460 log_packet(ssh->logctx, PKT_INCOMING, pkt->type,
1461 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->type),
1462 pkt->body, pkt->length, nblanks, blanks, &pkt->sequence,
1466 static void ssh2_log_outgoing_packet(Ssh ssh, struct Packet *pkt)
1469 struct logblank_t blanks[4];
1474 * For outgoing packets, pkt->length represents the length of the
1475 * whole packet starting at pkt->data (including some header), and
1476 * pkt->body refers to the point within that where the log-worthy
1477 * payload begins. However, incoming packets expect pkt->length to
1478 * represent only the payload length (that is, it's measured from
1479 * pkt->body not from pkt->data). Temporarily adjust our outgoing
1480 * packet to conform to the incoming-packet semantics, so that we
1481 * can analyse it with the ssh_pkt_get functions.
1483 pkt->length -= (pkt->body - pkt->data);
1486 if (ssh->logomitdata &&
1487 (pkt->type == SSH2_MSG_CHANNEL_DATA ||
1488 pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)) {
1489 /* "Session data" packets - omit the data string. */
1490 ssh_pkt_getuint32(pkt); /* skip channel id */
1491 if (pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)
1492 ssh_pkt_getuint32(pkt); /* skip extended data type */
1493 blanks[nblanks].offset = pkt->savedpos + 4;
1494 blanks[nblanks].type = PKTLOG_OMIT;
1495 ssh_pkt_getstring(pkt, &str, &slen);
1497 blanks[nblanks].len = slen;
1502 if (pkt->type == SSH2_MSG_USERAUTH_REQUEST &&
1503 conf_get_int(ssh->conf, CONF_logomitpass)) {
1504 /* If this is a password packet, blank the password(s). */
1506 ssh_pkt_getstring(pkt, &str, &slen);
1507 ssh_pkt_getstring(pkt, &str, &slen);
1508 ssh_pkt_getstring(pkt, &str, &slen);
1509 if (slen == 8 && !memcmp(str, "password", 8)) {
1510 ssh2_pkt_getbool(pkt);
1511 /* Blank the password field. */
1512 blanks[nblanks].offset = pkt->savedpos;
1513 blanks[nblanks].type = PKTLOG_BLANK;
1514 ssh_pkt_getstring(pkt, &str, &slen);
1516 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1518 /* If there's another password field beyond it (change of
1519 * password), blank that too. */
1520 ssh_pkt_getstring(pkt, &str, &slen);
1522 blanks[nblanks-1].len =
1523 pkt->savedpos - blanks[nblanks].offset;
1526 } else if (ssh->pkt_actx == SSH2_PKTCTX_KBDINTER &&
1527 pkt->type == SSH2_MSG_USERAUTH_INFO_RESPONSE &&
1528 conf_get_int(ssh->conf, CONF_logomitpass)) {
1529 /* If this is a keyboard-interactive response packet, blank
1532 ssh_pkt_getuint32(pkt);
1533 blanks[nblanks].offset = pkt->savedpos;
1534 blanks[nblanks].type = PKTLOG_BLANK;
1536 ssh_pkt_getstring(pkt, &str, &slen);
1540 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1542 } else if (pkt->type == SSH2_MSG_CHANNEL_REQUEST &&
1543 conf_get_int(ssh->conf, CONF_logomitpass)) {
1545 * If this is an X forwarding request packet, blank the fake
1548 * Note that while we blank the X authentication data here, we
1549 * don't take any special action to blank the start of an X11
1550 * channel, so using MIT-MAGIC-COOKIE-1 and actually opening
1551 * an X connection without having session blanking enabled is
1552 * likely to leak your cookie into the log.
1555 ssh_pkt_getuint32(pkt);
1556 ssh_pkt_getstring(pkt, &str, &slen);
1557 if (slen == 7 && !memcmp(str, "x11-req", 0)) {
1558 ssh2_pkt_getbool(pkt);
1559 ssh2_pkt_getbool(pkt);
1560 ssh_pkt_getstring(pkt, &str, &slen);
1561 blanks[nblanks].offset = pkt->savedpos;
1562 blanks[nblanks].type = PKTLOG_BLANK;
1563 ssh_pkt_getstring(pkt, &str, &slen);
1565 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1571 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1572 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]),
1573 pkt->body, pkt->length, nblanks, blanks,
1574 &ssh->v2_outgoing_sequence,
1575 pkt->downstream_id, pkt->additional_log_text);
1578 * Undo the above adjustment of pkt->length, to put the packet
1579 * back in the state we found it.
1581 pkt->length += (pkt->body - pkt->data);
1584 static struct Packet *ssh2_rdpkt(Ssh ssh, const unsigned char **data,
1587 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1589 crBegin(ssh->ssh2_rdpkt_crstate);
1591 st->pktin = ssh_new_packet();
1593 st->pktin->type = 0;
1594 st->pktin->length = 0;
1596 st->cipherblk = ssh->sccipher->blksize;
1599 if (st->cipherblk < 8)
1601 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1603 if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_IS_CBC) &&
1604 ssh->scmac && !ssh->scmac_etm) {
1606 * When dealing with a CBC-mode cipher, we want to avoid the
1607 * possibility of an attacker's tweaking the ciphertext stream
1608 * so as to cause us to feed the same block to the block
1609 * cipher more than once and thus leak information
1610 * (VU#958563). The way we do this is not to take any
1611 * decisions on the basis of anything we've decrypted until
1612 * we've verified it with a MAC. That includes the packet
1613 * length, so we just read data and check the MAC repeatedly,
1614 * and when the MAC passes, see if the length we've got is
1617 * This defence is unnecessary in OpenSSH ETM mode, because
1618 * the whole point of ETM mode is that the attacker can't
1619 * tweak the ciphertext stream at all without the MAC
1620 * detecting it before we decrypt anything.
1623 /* May as well allocate the whole lot now. */
1624 st->pktin->data = snewn(OUR_V2_PACKETLIMIT + st->maclen + APIEXTRA,
1627 /* Read an amount corresponding to the MAC. */
1628 for (st->i = 0; st->i < st->maclen; st->i++) {
1629 while ((*datalen) == 0)
1631 st->pktin->data[st->i] = *(*data)++;
1637 unsigned char seq[4];
1638 ssh->scmac->start(ssh->sc_mac_ctx);
1639 PUT_32BIT(seq, st->incoming_sequence);
1640 ssh->scmac->bytes(ssh->sc_mac_ctx, seq, 4);
1643 for (;;) { /* Once around this loop per cipher block. */
1644 /* Read another cipher-block's worth, and tack it onto the end. */
1645 for (st->i = 0; st->i < st->cipherblk; st->i++) {
1646 while ((*datalen) == 0)
1648 st->pktin->data[st->packetlen+st->maclen+st->i] = *(*data)++;
1651 /* Decrypt one more block (a little further back in the stream). */
1652 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1653 st->pktin->data + st->packetlen,
1655 /* Feed that block to the MAC. */
1656 ssh->scmac->bytes(ssh->sc_mac_ctx,
1657 st->pktin->data + st->packetlen, st->cipherblk);
1658 st->packetlen += st->cipherblk;
1659 /* See if that gives us a valid packet. */
1660 if (ssh->scmac->verresult(ssh->sc_mac_ctx,
1661 st->pktin->data + st->packetlen) &&
1662 ((st->len = toint(GET_32BIT(st->pktin->data))) ==
1665 if (st->packetlen >= OUR_V2_PACKETLIMIT) {
1666 bombout(("No valid incoming packet found"));
1667 ssh_free_packet(st->pktin);
1671 st->pktin->maxlen = st->packetlen + st->maclen;
1672 st->pktin->data = sresize(st->pktin->data,
1673 st->pktin->maxlen + APIEXTRA,
1675 } else if (ssh->scmac && ssh->scmac_etm) {
1676 st->pktin->data = snewn(4 + APIEXTRA, unsigned char);
1679 * OpenSSH encrypt-then-MAC mode: the packet length is
1680 * unencrypted, unless the cipher supports length encryption.
1682 for (st->i = st->len = 0; st->i < 4; st->i++) {
1683 while ((*datalen) == 0)
1685 st->pktin->data[st->i] = *(*data)++;
1688 /* Cipher supports length decryption, so do it */
1689 if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_SEPARATE_LENGTH)) {
1690 /* Keep the packet the same though, so the MAC passes */
1691 unsigned char len[4];
1692 memcpy(len, st->pktin->data, 4);
1693 ssh->sccipher->decrypt_length(ssh->sc_cipher_ctx, len, 4, st->incoming_sequence);
1694 st->len = toint(GET_32BIT(len));
1696 st->len = toint(GET_32BIT(st->pktin->data));
1700 * _Completely_ silly lengths should be stomped on before they
1701 * do us any more damage.
1703 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1704 st->len % st->cipherblk != 0) {
1705 bombout(("Incoming packet length field was garbled"));
1706 ssh_free_packet(st->pktin);
1711 * So now we can work out the total packet length.
1713 st->packetlen = st->len + 4;
1716 * Allocate memory for the rest of the packet.
1718 st->pktin->maxlen = st->packetlen + st->maclen;
1719 st->pktin->data = sresize(st->pktin->data,
1720 st->pktin->maxlen + APIEXTRA,
1724 * Read the remainder of the packet.
1726 for (st->i = 4; st->i < st->packetlen + st->maclen; st->i++) {
1727 while ((*datalen) == 0)
1729 st->pktin->data[st->i] = *(*data)++;
1737 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1738 st->len + 4, st->incoming_sequence)) {
1739 bombout(("Incorrect MAC received on packet"));
1740 ssh_free_packet(st->pktin);
1744 /* Decrypt everything between the length field and the MAC. */
1746 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1747 st->pktin->data + 4,
1750 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1753 * Acquire and decrypt the first block of the packet. This will
1754 * contain the length and padding details.
1756 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1757 while ((*datalen) == 0)
1759 st->pktin->data[st->i] = *(*data)++;
1764 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1765 st->pktin->data, st->cipherblk);
1768 * Now get the length figure.
1770 st->len = toint(GET_32BIT(st->pktin->data));
1773 * _Completely_ silly lengths should be stomped on before they
1774 * do us any more damage.
1776 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1777 (st->len + 4) % st->cipherblk != 0) {
1778 bombout(("Incoming packet was garbled on decryption"));
1779 ssh_free_packet(st->pktin);
1784 * So now we can work out the total packet length.
1786 st->packetlen = st->len + 4;
1789 * Allocate memory for the rest of the packet.
1791 st->pktin->maxlen = st->packetlen + st->maclen;
1792 st->pktin->data = sresize(st->pktin->data,
1793 st->pktin->maxlen + APIEXTRA,
1797 * Read and decrypt the remainder of the packet.
1799 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1801 while ((*datalen) == 0)
1803 st->pktin->data[st->i] = *(*data)++;
1806 /* Decrypt everything _except_ the MAC. */
1808 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1809 st->pktin->data + st->cipherblk,
1810 st->packetlen - st->cipherblk);
1816 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1817 st->len + 4, st->incoming_sequence)) {
1818 bombout(("Incorrect MAC received on packet"));
1819 ssh_free_packet(st->pktin);
1823 /* Get and sanity-check the amount of random padding. */
1824 st->pad = st->pktin->data[4];
1825 if (st->pad < 4 || st->len - st->pad < 1) {
1826 bombout(("Invalid padding length on received packet"));
1827 ssh_free_packet(st->pktin);
1831 * This enables us to deduce the payload length.
1833 st->payload = st->len - st->pad - 1;
1835 st->pktin->length = st->payload + 5;
1836 st->pktin->encrypted_len = st->packetlen;
1838 st->pktin->sequence = st->incoming_sequence++;
1840 st->pktin->length = st->packetlen - st->pad;
1841 assert(st->pktin->length >= 0);
1844 * Decompress packet payload.
1847 unsigned char *newpayload;
1850 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1851 st->pktin->data + 5, st->pktin->length - 5,
1852 &newpayload, &newlen)) {
1853 if (st->pktin->maxlen < newlen + 5) {
1854 st->pktin->maxlen = newlen + 5;
1855 st->pktin->data = sresize(st->pktin->data,
1856 st->pktin->maxlen + APIEXTRA,
1859 st->pktin->length = 5 + newlen;
1860 memcpy(st->pktin->data + 5, newpayload, newlen);
1866 * RFC 4253 doesn't explicitly say that completely empty packets
1867 * with no type byte are forbidden, so treat them as deserving
1868 * an SSH_MSG_UNIMPLEMENTED.
1870 if (st->pktin->length <= 5) { /* == 5 we hope, but robustness */
1871 ssh2_msg_something_unimplemented(ssh, st->pktin);
1875 * pktin->body and pktin->length should identify the semantic
1876 * content of the packet, excluding the initial type byte.
1878 st->pktin->type = st->pktin->data[5];
1879 st->pktin->body = st->pktin->data + 6;
1880 st->pktin->length -= 6;
1881 assert(st->pktin->length >= 0); /* one last double-check */
1884 ssh2_log_incoming_packet(ssh, st->pktin);
1886 st->pktin->savedpos = 0;
1888 crFinish(st->pktin);
1891 static struct Packet *ssh2_bare_connection_rdpkt(Ssh ssh,
1892 const unsigned char **data,
1895 struct rdpkt2_bare_state_tag *st = &ssh->rdpkt2_bare_state;
1897 crBegin(ssh->ssh2_bare_rdpkt_crstate);
1900 * Read the packet length field.
1902 for (st->i = 0; st->i < 4; st->i++) {
1903 while ((*datalen) == 0)
1905 st->length[st->i] = *(*data)++;
1909 st->packetlen = toint(GET_32BIT_MSB_FIRST(st->length));
1910 if (st->packetlen <= 0 || st->packetlen >= OUR_V2_PACKETLIMIT) {
1911 bombout(("Invalid packet length received"));
1915 st->pktin = ssh_new_packet();
1916 st->pktin->data = snewn(st->packetlen, unsigned char);
1918 st->pktin->encrypted_len = st->packetlen;
1920 st->pktin->sequence = st->incoming_sequence++;
1923 * Read the remainder of the packet.
1925 for (st->i = 0; st->i < st->packetlen; st->i++) {
1926 while ((*datalen) == 0)
1928 st->pktin->data[st->i] = *(*data)++;
1933 * pktin->body and pktin->length should identify the semantic
1934 * content of the packet, excluding the initial type byte.
1936 st->pktin->type = st->pktin->data[0];
1937 st->pktin->body = st->pktin->data + 1;
1938 st->pktin->length = st->packetlen - 1;
1941 * Log incoming packet, possibly omitting sensitive fields.
1944 ssh2_log_incoming_packet(ssh, st->pktin);
1946 st->pktin->savedpos = 0;
1948 crFinish(st->pktin);
1951 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1953 int pad, biglen, i, pktoffs;
1957 * XXX various versions of SC (including 8.8.4) screw up the
1958 * register allocation in this function and use the same register
1959 * (D6) for len and as a temporary, with predictable results. The
1960 * following sledgehammer prevents this.
1967 ssh1_log_outgoing_packet(ssh, pkt);
1969 if (ssh->v1_compressing) {
1970 unsigned char *compblk;
1972 zlib_compress_block(ssh->cs_comp_ctx,
1973 pkt->data + 12, pkt->length - 12,
1974 &compblk, &complen);
1975 ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */
1976 memcpy(pkt->data + 12, compblk, complen);
1978 pkt->length = complen + 12;
1981 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1983 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
1984 pad = 8 - (len % 8);
1986 biglen = len + pad; /* len(padding+type+data+CRC) */
1988 for (i = pktoffs; i < 4+8; i++)
1989 pkt->data[i] = random_byte();
1990 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1991 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1992 PUT_32BIT(pkt->data + pktoffs, len);
1995 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1996 pkt->data + pktoffs + 4, biglen);
1998 if (offset_p) *offset_p = pktoffs;
1999 return biglen + 4; /* len(length+padding+type+data+CRC) */
2002 static int s_write(Ssh ssh, void *data, int len)
2005 log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len,
2006 0, NULL, NULL, 0, NULL);
2009 return sk_write(ssh->s, (char *)data, len);
2012 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
2014 int len, backlog, offset;
2015 len = s_wrpkt_prepare(ssh, pkt, &offset);
2016 backlog = s_write(ssh, pkt->data + offset, len);
2017 if (backlog > SSH_MAX_BACKLOG)
2018 ssh_throttle_all(ssh, 1, backlog);
2019 ssh_free_packet(pkt);
2022 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
2025 len = s_wrpkt_prepare(ssh, pkt, &offset);
2026 if (ssh->deferred_len + len > ssh->deferred_size) {
2027 ssh->deferred_size = ssh->deferred_len + len + 128;
2028 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2032 memcpy(ssh->deferred_send_data + ssh->deferred_len,
2033 pkt->data + offset, len);
2034 ssh->deferred_len += len;
2035 ssh_free_packet(pkt);
2039 * Construct a SSH-1 packet with the specified contents.
2040 * (This all-at-once interface used to be the only one, but now SSH-1
2041 * packets can also be constructed incrementally.)
2043 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
2049 pkt = ssh1_pkt_init(pkttype);
2051 while ((argtype = va_arg(ap, int)) != PKT_END) {
2052 unsigned char *argp, argchar;
2054 unsigned long argint;
2057 /* Actual fields in the packet */
2059 argint = va_arg(ap, int);
2060 ssh_pkt_adduint32(pkt, argint);
2063 argchar = (unsigned char) va_arg(ap, int);
2064 ssh_pkt_addbyte(pkt, argchar);
2067 argp = va_arg(ap, unsigned char *);
2068 arglen = va_arg(ap, int);
2069 ssh_pkt_adddata(pkt, argp, arglen);
2072 sargp = va_arg(ap, char *);
2073 ssh_pkt_addstring(pkt, sargp);
2076 bn = va_arg(ap, Bignum);
2077 ssh1_pkt_addmp(pkt, bn);
2085 static void send_packet(Ssh ssh, int pkttype, ...)
2089 va_start(ap, pkttype);
2090 pkt = construct_packet(ssh, pkttype, ap);
2095 static void defer_packet(Ssh ssh, int pkttype, ...)
2099 va_start(ap, pkttype);
2100 pkt = construct_packet(ssh, pkttype, ap);
2102 s_wrpkt_defer(ssh, pkt);
2105 static int ssh_versioncmp(const char *a, const char *b)
2108 unsigned long av, bv;
2110 av = strtoul(a, &ae, 10);
2111 bv = strtoul(b, &be, 10);
2113 return (av < bv ? -1 : +1);
2118 av = strtoul(ae, &ae, 10);
2119 bv = strtoul(be, &be, 10);
2121 return (av < bv ? -1 : +1);
2126 * Utility routines for putting an SSH-protocol `string' and
2127 * `uint32' into a hash state.
2129 static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
2131 unsigned char lenblk[4];
2132 PUT_32BIT(lenblk, len);
2133 h->bytes(s, lenblk, 4);
2134 h->bytes(s, str, len);
2137 static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
2139 unsigned char intblk[4];
2140 PUT_32BIT(intblk, i);
2141 h->bytes(s, intblk, 4);
2145 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
2147 static void ssh_pkt_ensure(struct Packet *pkt, int length)
2149 if (pkt->maxlen < length) {
2150 unsigned char *body = pkt->body;
2151 int offset = body ? body - pkt->data : 0;
2152 pkt->maxlen = length + 256;
2153 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
2154 if (body) pkt->body = pkt->data + offset;
2157 static void ssh_pkt_adddata(struct Packet *pkt, const void *data, int len)
2160 ssh_pkt_ensure(pkt, pkt->length);
2161 memcpy(pkt->data + pkt->length - len, data, len);
2163 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
2165 ssh_pkt_adddata(pkt, &byte, 1);
2167 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
2169 ssh_pkt_adddata(pkt, &value, 1);
2171 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
2174 PUT_32BIT(x, value);
2175 ssh_pkt_adddata(pkt, x, 4);
2177 static void ssh_pkt_addstring_start(struct Packet *pkt)
2179 ssh_pkt_adduint32(pkt, 0);
2180 pkt->savedpos = pkt->length;
2182 static void ssh_pkt_addstring_data(struct Packet *pkt, const char *data,
2185 ssh_pkt_adddata(pkt, data, len);
2186 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
2188 static void ssh_pkt_addstring_str(struct Packet *pkt, const char *data)
2190 ssh_pkt_addstring_data(pkt, data, strlen(data));
2192 static void ssh_pkt_addstring(struct Packet *pkt, const char *data)
2194 ssh_pkt_addstring_start(pkt);
2195 ssh_pkt_addstring_str(pkt, data);
2197 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
2199 int len = ssh1_bignum_length(b);
2200 unsigned char *data = snewn(len, unsigned char);
2201 (void) ssh1_write_bignum(data, b);
2202 ssh_pkt_adddata(pkt, data, len);
2205 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
2208 int i, n = (bignum_bitcount(b) + 7) / 8;
2209 p = snewn(n + 1, unsigned char);
2211 for (i = 1; i <= n; i++)
2212 p[i] = bignum_byte(b, n - i);
2214 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
2216 memmove(p, p + i, n + 1 - i);
2220 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
2224 p = ssh2_mpint_fmt(b, &len);
2225 ssh_pkt_addstring_start(pkt);
2226 ssh_pkt_addstring_data(pkt, (char *)p, len);
2230 static struct Packet *ssh1_pkt_init(int pkt_type)
2232 struct Packet *pkt = ssh_new_packet();
2233 pkt->length = 4 + 8; /* space for length + max padding */
2234 ssh_pkt_addbyte(pkt, pkt_type);
2235 pkt->body = pkt->data + pkt->length;
2236 pkt->type = pkt_type;
2237 pkt->downstream_id = 0;
2238 pkt->additional_log_text = NULL;
2242 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
2243 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
2244 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
2245 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
2246 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
2247 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
2248 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
2249 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
2250 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
2252 static struct Packet *ssh2_pkt_init(int pkt_type)
2254 struct Packet *pkt = ssh_new_packet();
2255 pkt->length = 5; /* space for packet length + padding length */
2257 pkt->type = pkt_type;
2258 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
2259 pkt->body = pkt->data + pkt->length; /* after packet type */
2260 pkt->downstream_id = 0;
2261 pkt->additional_log_text = NULL;
2266 * Construct an SSH-2 final-form packet: compress it, encrypt it,
2267 * put the MAC on it. Final packet, ready to be sent, is stored in
2268 * pkt->data. Total length is returned.
2270 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
2272 int cipherblk, maclen, padding, unencrypted_prefix, i;
2275 ssh2_log_outgoing_packet(ssh, pkt);
2277 if (ssh->bare_connection) {
2279 * Trivial packet construction for the bare connection
2282 PUT_32BIT(pkt->data + 1, pkt->length - 5);
2283 pkt->body = pkt->data + 1;
2284 ssh->v2_outgoing_sequence++; /* only for diagnostics, really */
2285 return pkt->length - 1;
2289 * Compress packet payload.
2292 unsigned char *newpayload;
2295 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
2297 &newpayload, &newlen)) {
2299 ssh2_pkt_adddata(pkt, newpayload, newlen);
2305 * Add padding. At least four bytes, and must also bring total
2306 * length (minus MAC) up to a multiple of the block size.
2307 * If pkt->forcepad is set, make sure the packet is at least that size
2310 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
2311 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
2313 unencrypted_prefix = (ssh->csmac && ssh->csmac_etm) ? 4 : 0;
2314 if (pkt->length + padding < pkt->forcepad)
2315 padding = pkt->forcepad - pkt->length;
2317 (cipherblk - (pkt->length - unencrypted_prefix + padding) % cipherblk)
2319 assert(padding <= 255);
2320 maclen = ssh->csmac ? ssh->csmac->len : 0;
2321 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
2322 pkt->data[4] = padding;
2323 for (i = 0; i < padding; i++)
2324 pkt->data[pkt->length + i] = random_byte();
2325 PUT_32BIT(pkt->data, pkt->length + padding - 4);
2327 /* Encrypt length if the scheme requires it */
2328 if (ssh->cscipher && (ssh->cscipher->flags & SSH_CIPHER_SEPARATE_LENGTH)) {
2329 ssh->cscipher->encrypt_length(ssh->cs_cipher_ctx, pkt->data, 4,
2330 ssh->v2_outgoing_sequence);
2333 if (ssh->csmac && ssh->csmac_etm) {
2335 * OpenSSH-defined encrypt-then-MAC protocol.
2338 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
2339 pkt->data + 4, pkt->length + padding - 4);
2340 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
2341 pkt->length + padding,
2342 ssh->v2_outgoing_sequence);
2345 * SSH-2 standard protocol.
2348 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
2349 pkt->length + padding,
2350 ssh->v2_outgoing_sequence);
2352 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
2353 pkt->data, pkt->length + padding);
2356 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
2357 pkt->encrypted_len = pkt->length + padding;
2359 /* Ready-to-send packet starts at pkt->data. We return length. */
2360 pkt->body = pkt->data;
2361 return pkt->length + padding + maclen;
2365 * Routines called from the main SSH code to send packets. There
2366 * are quite a few of these, because we have two separate
2367 * mechanisms for delaying the sending of packets:
2369 * - In order to send an IGNORE message and a password message in
2370 * a single fixed-length blob, we require the ability to
2371 * concatenate the encrypted forms of those two packets _into_ a
2372 * single blob and then pass it to our <network.h> transport
2373 * layer in one go. Hence, there's a deferment mechanism which
2374 * works after packet encryption.
2376 * - In order to avoid sending any connection-layer messages
2377 * during repeat key exchange, we have to queue up any such
2378 * outgoing messages _before_ they are encrypted (and in
2379 * particular before they're allocated sequence numbers), and
2380 * then send them once we've finished.
2382 * I call these mechanisms `defer' and `queue' respectively, so as
2383 * to distinguish them reasonably easily.
2385 * The functions send_noqueue() and defer_noqueue() free the packet
2386 * structure they are passed. Every outgoing packet goes through
2387 * precisely one of these functions in its life; packets passed to
2388 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
2389 * these or get queued, and then when the queue is later emptied
2390 * the packets are all passed to defer_noqueue().
2392 * When using a CBC-mode cipher, it's necessary to ensure that an
2393 * attacker can't provide data to be encrypted using an IV that they
2394 * know. We ensure this by prefixing each packet that might contain
2395 * user data with an SSH_MSG_IGNORE. This is done using the deferral
2396 * mechanism, so in this case send_noqueue() ends up redirecting to
2397 * defer_noqueue(). If you don't like this inefficiency, don't use
2401 static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
2402 static void ssh_pkt_defersend(Ssh);
2405 * Send an SSH-2 packet immediately, without queuing or deferring.
2407 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
2411 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
2412 /* We need to send two packets, so use the deferral mechanism. */
2413 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2414 ssh_pkt_defersend(ssh);
2417 len = ssh2_pkt_construct(ssh, pkt);
2418 backlog = s_write(ssh, pkt->body, len);
2419 if (backlog > SSH_MAX_BACKLOG)
2420 ssh_throttle_all(ssh, 1, backlog);
2422 ssh->outgoing_data_size += pkt->encrypted_len;
2423 if (!ssh->kex_in_progress &&
2424 !ssh->bare_connection &&
2425 ssh->max_data_size != 0 &&
2426 ssh->outgoing_data_size > ssh->max_data_size)
2427 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2429 ssh_free_packet(pkt);
2433 * Defer an SSH-2 packet.
2435 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
2438 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
2439 ssh->deferred_len == 0 && !noignore &&
2440 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2442 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2443 * get encrypted with a known IV.
2445 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2446 ssh2_pkt_addstring_start(ipkt);
2447 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
2449 len = ssh2_pkt_construct(ssh, pkt);
2450 if (ssh->deferred_len + len > ssh->deferred_size) {
2451 ssh->deferred_size = ssh->deferred_len + len + 128;
2452 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2456 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->body, len);
2457 ssh->deferred_len += len;
2458 ssh->deferred_data_size += pkt->encrypted_len;
2459 ssh_free_packet(pkt);
2463 * Queue an SSH-2 packet.
2465 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
2467 assert(ssh->queueing);
2469 if (ssh->queuelen >= ssh->queuesize) {
2470 ssh->queuesize = ssh->queuelen + 32;
2471 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
2474 ssh->queue[ssh->queuelen++] = pkt;
2478 * Either queue or send a packet, depending on whether queueing is
2481 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
2484 ssh2_pkt_queue(ssh, pkt);
2486 ssh2_pkt_send_noqueue(ssh, pkt);
2490 * Either queue or defer a packet, depending on whether queueing is
2493 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
2496 ssh2_pkt_queue(ssh, pkt);
2498 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2502 * Send the whole deferred data block constructed by
2503 * ssh2_pkt_defer() or SSH-1's defer_packet().
2505 * The expected use of the defer mechanism is that you call
2506 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2507 * not currently queueing, this simply sets up deferred_send_data
2508 * and then sends it. If we _are_ currently queueing, the calls to
2509 * ssh2_pkt_defer() put the deferred packets on to the queue
2510 * instead, and therefore ssh_pkt_defersend() has no deferred data
2511 * to send. Hence, there's no need to make it conditional on
2514 static void ssh_pkt_defersend(Ssh ssh)
2517 backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
2518 ssh->deferred_len = ssh->deferred_size = 0;
2519 sfree(ssh->deferred_send_data);
2520 ssh->deferred_send_data = NULL;
2521 if (backlog > SSH_MAX_BACKLOG)
2522 ssh_throttle_all(ssh, 1, backlog);
2524 ssh->outgoing_data_size += ssh->deferred_data_size;
2525 if (!ssh->kex_in_progress &&
2526 !ssh->bare_connection &&
2527 ssh->max_data_size != 0 &&
2528 ssh->outgoing_data_size > ssh->max_data_size)
2529 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2530 ssh->deferred_data_size = 0;
2534 * Send a packet whose length needs to be disguised (typically
2535 * passwords or keyboard-interactive responses).
2537 static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
2543 * The simplest way to do this is to adjust the
2544 * variable-length padding field in the outgoing packet.
2546 * Currently compiled out, because some Cisco SSH servers
2547 * don't like excessively padded packets (bah, why's it
2550 pkt->forcepad = padsize;
2551 ssh2_pkt_send(ssh, pkt);
2556 * If we can't do that, however, an alternative approach is
2557 * to use the pkt_defer mechanism to bundle the packet
2558 * tightly together with an SSH_MSG_IGNORE such that their
2559 * combined length is a constant. So first we construct the
2560 * final form of this packet and defer its sending.
2562 ssh2_pkt_defer(ssh, pkt);
2565 * Now construct an SSH_MSG_IGNORE which includes a string
2566 * that's an exact multiple of the cipher block size. (If
2567 * the cipher is NULL so that the block size is
2568 * unavailable, we don't do this trick at all, because we
2569 * gain nothing by it.)
2571 if (ssh->cscipher &&
2572 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2575 stringlen = (256 - ssh->deferred_len);
2576 stringlen += ssh->cscipher->blksize - 1;
2577 stringlen -= (stringlen % ssh->cscipher->blksize);
2580 * Temporarily disable actual compression, so we
2581 * can guarantee to get this string exactly the
2582 * length we want it. The compression-disabling
2583 * routine should return an integer indicating how
2584 * many bytes we should adjust our string length
2588 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
2590 pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2591 ssh2_pkt_addstring_start(pkt);
2592 for (i = 0; i < stringlen; i++) {
2593 char c = (char) random_byte();
2594 ssh2_pkt_addstring_data(pkt, &c, 1);
2596 ssh2_pkt_defer(ssh, pkt);
2598 ssh_pkt_defersend(ssh);
2603 * Send all queued SSH-2 packets. We send them by means of
2604 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2605 * packets that needed to be lumped together.
2607 static void ssh2_pkt_queuesend(Ssh ssh)
2611 assert(!ssh->queueing);
2613 for (i = 0; i < ssh->queuelen; i++)
2614 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
2617 ssh_pkt_defersend(ssh);
2621 void bndebug(char *string, Bignum b)
2625 p = ssh2_mpint_fmt(b, &len);
2626 debug(("%s", string));
2627 for (i = 0; i < len; i++)
2628 debug((" %02x", p[i]));
2634 static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
2638 p = ssh2_mpint_fmt(b, &len);
2639 hash_string(h, s, p, len);
2644 * Packet decode functions for both SSH-1 and SSH-2.
2646 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
2648 unsigned long value;
2649 if (pkt->length - pkt->savedpos < 4)
2650 return 0; /* arrgh, no way to decline (FIXME?) */
2651 value = GET_32BIT(pkt->body + pkt->savedpos);
2655 static int ssh2_pkt_getbool(struct Packet *pkt)
2657 unsigned long value;
2658 if (pkt->length - pkt->savedpos < 1)
2659 return 0; /* arrgh, no way to decline (FIXME?) */
2660 value = pkt->body[pkt->savedpos] != 0;
2664 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
2669 if (pkt->length - pkt->savedpos < 4)
2671 len = toint(GET_32BIT(pkt->body + pkt->savedpos));
2676 if (pkt->length - pkt->savedpos < *length)
2678 *p = (char *)(pkt->body + pkt->savedpos);
2679 pkt->savedpos += *length;
2681 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
2683 if (pkt->length - pkt->savedpos < length)
2685 pkt->savedpos += length;
2686 return pkt->body + (pkt->savedpos - length);
2688 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2689 const unsigned char **keystr)
2693 j = makekey(pkt->body + pkt->savedpos,
2694 pkt->length - pkt->savedpos,
2701 assert(pkt->savedpos < pkt->length);
2705 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2710 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2711 pkt->length - pkt->savedpos, &b);
2719 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2725 ssh_pkt_getstring(pkt, &p, &length);
2730 b = bignum_from_bytes((unsigned char *)p, length);
2735 * Helper function to add an SSH-2 signature blob to a packet.
2736 * Expects to be shown the public key blob as well as the signature
2737 * blob. Normally works just like ssh2_pkt_addstring, but will
2738 * fiddle with the signature packet if necessary for
2739 * BUG_SSH2_RSA_PADDING.
2741 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2742 void *pkblob_v, int pkblob_len,
2743 void *sigblob_v, int sigblob_len)
2745 unsigned char *pkblob = (unsigned char *)pkblob_v;
2746 unsigned char *sigblob = (unsigned char *)sigblob_v;
2748 /* dmemdump(pkblob, pkblob_len); */
2749 /* dmemdump(sigblob, sigblob_len); */
2752 * See if this is in fact an ssh-rsa signature and a buggy
2753 * server; otherwise we can just do this the easy way.
2755 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) && pkblob_len > 4+7+4 &&
2756 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2757 int pos, len, siglen;
2760 * Find the byte length of the modulus.
2763 pos = 4+7; /* skip over "ssh-rsa" */
2764 len = toint(GET_32BIT(pkblob+pos)); /* get length of exponent */
2765 if (len < 0 || len > pkblob_len - pos - 4)
2767 pos += 4 + len; /* skip over exponent */
2768 if (pkblob_len - pos < 4)
2770 len = toint(GET_32BIT(pkblob+pos)); /* find length of modulus */
2771 if (len < 0 || len > pkblob_len - pos - 4)
2773 pos += 4; /* find modulus itself */
2774 while (len > 0 && pkblob[pos] == 0)
2776 /* debug(("modulus length is %d\n", len)); */
2779 * Now find the signature integer.
2781 pos = 4+7; /* skip over "ssh-rsa" */
2782 if (sigblob_len < pos+4)
2784 siglen = toint(GET_32BIT(sigblob+pos));
2785 if (siglen != sigblob_len - pos - 4)
2787 /* debug(("signature length is %d\n", siglen)); */
2789 if (len != siglen) {
2790 unsigned char newlen[4];
2791 ssh2_pkt_addstring_start(pkt);
2792 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2793 /* dmemdump(sigblob, pos); */
2794 pos += 4; /* point to start of actual sig */
2795 PUT_32BIT(newlen, len);
2796 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2797 /* dmemdump(newlen, 4); */
2799 while (len-- > siglen) {
2800 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2801 /* dmemdump(newlen, 1); */
2803 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2804 /* dmemdump(sigblob+pos, siglen); */
2808 /* Otherwise fall through and do it the easy way. We also come
2809 * here as a fallback if we discover above that the key blob
2810 * is misformatted in some way. */
2814 ssh2_pkt_addstring_start(pkt);
2815 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2819 * Examine the remote side's version string and compare it against
2820 * a list of known buggy implementations.
2822 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2824 char *imp; /* pointer to implementation part */
2826 imp += strcspn(imp, "-");
2828 imp += strcspn(imp, "-");
2831 ssh->remote_bugs = 0;
2834 * General notes on server version strings:
2835 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2836 * here -- in particular, we've heard of one that's perfectly happy
2837 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2838 * so we can't distinguish them.
2840 if (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == FORCE_ON ||
2841 (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == AUTO &&
2842 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2843 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2844 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2845 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2847 * These versions don't support SSH1_MSG_IGNORE, so we have
2848 * to use a different defence against password length
2851 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2852 logevent("We believe remote version has SSH-1 ignore bug");
2855 if (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == FORCE_ON ||
2856 (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == AUTO &&
2857 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2859 * These versions need a plain password sent; they can't
2860 * handle having a null and a random length of data after
2863 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2864 logevent("We believe remote version needs a plain SSH-1 password");
2867 if (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == FORCE_ON ||
2868 (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == AUTO &&
2869 (!strcmp(imp, "Cisco-1.25")))) {
2871 * These versions apparently have no clue whatever about
2872 * RSA authentication and will panic and die if they see
2873 * an AUTH_RSA message.
2875 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2876 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2879 if (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == FORCE_ON ||
2880 (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == AUTO &&
2881 !wc_match("* VShell", imp) &&
2882 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2883 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2884 wc_match("2.1 *", imp)))) {
2886 * These versions have the HMAC bug.
2888 ssh->remote_bugs |= BUG_SSH2_HMAC;
2889 logevent("We believe remote version has SSH-2 HMAC bug");
2892 if (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == FORCE_ON ||
2893 (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == AUTO &&
2894 !wc_match("* VShell", imp) &&
2895 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2897 * These versions have the key-derivation bug (failing to
2898 * include the literal shared secret in the hashes that
2899 * generate the keys).
2901 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2902 logevent("We believe remote version has SSH-2 key-derivation bug");
2905 if (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == FORCE_ON ||
2906 (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == AUTO &&
2907 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2908 wc_match("OpenSSH_3.[0-2]*", imp) ||
2909 wc_match("mod_sftp/0.[0-8]*", imp) ||
2910 wc_match("mod_sftp/0.9.[0-8]", imp)))) {
2912 * These versions have the SSH-2 RSA padding bug.
2914 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2915 logevent("We believe remote version has SSH-2 RSA padding bug");
2918 if (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == FORCE_ON ||
2919 (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == AUTO &&
2920 wc_match("OpenSSH_2.[0-2]*", imp))) {
2922 * These versions have the SSH-2 session-ID bug in
2923 * public-key authentication.
2925 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2926 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2929 if (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == FORCE_ON ||
2930 (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == AUTO &&
2931 (wc_match("DigiSSH_2.0", imp) ||
2932 wc_match("OpenSSH_2.[0-4]*", imp) ||
2933 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2934 wc_match("Sun_SSH_1.0", imp) ||
2935 wc_match("Sun_SSH_1.0.1", imp) ||
2936 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2937 wc_match("WeOnlyDo-*", imp)))) {
2939 * These versions have the SSH-2 rekey bug.
2941 ssh->remote_bugs |= BUG_SSH2_REKEY;
2942 logevent("We believe remote version has SSH-2 rekey bug");
2945 if (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == FORCE_ON ||
2946 (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == AUTO &&
2947 (wc_match("1.36_sshlib GlobalSCAPE", imp) ||
2948 wc_match("1.36 sshlib: GlobalScape", imp)))) {
2950 * This version ignores our makpkt and needs to be throttled.
2952 ssh->remote_bugs |= BUG_SSH2_MAXPKT;
2953 logevent("We believe remote version ignores SSH-2 maximum packet size");
2956 if (conf_get_int(ssh->conf, CONF_sshbug_ignore2) == FORCE_ON) {
2958 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2959 * none detected automatically.
2961 ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE;
2962 logevent("We believe remote version has SSH-2 ignore bug");
2965 if (conf_get_int(ssh->conf, CONF_sshbug_oldgex2) == FORCE_ON ||
2966 (conf_get_int(ssh->conf, CONF_sshbug_oldgex2) == AUTO &&
2967 (wc_match("OpenSSH_2.[235]*", imp)))) {
2969 * These versions only support the original (pre-RFC4419)
2970 * SSH-2 GEX request, and disconnect with a protocol error if
2971 * we use the newer version.
2973 ssh->remote_bugs |= BUG_SSH2_OLDGEX;
2974 logevent("We believe remote version has outdated SSH-2 GEX");
2977 if (conf_get_int(ssh->conf, CONF_sshbug_winadj) == FORCE_ON) {
2979 * Servers that don't support our winadj request for one
2980 * reason or another. Currently, none detected automatically.
2982 ssh->remote_bugs |= BUG_CHOKES_ON_WINADJ;
2983 logevent("We believe remote version has winadj bug");
2986 if (conf_get_int(ssh->conf, CONF_sshbug_chanreq) == FORCE_ON ||
2987 (conf_get_int(ssh->conf, CONF_sshbug_chanreq) == AUTO &&
2988 (wc_match("OpenSSH_[2-5].*", imp) ||
2989 wc_match("OpenSSH_6.[0-6]*", imp) ||
2990 wc_match("dropbear_0.[2-4][0-9]*", imp) ||
2991 wc_match("dropbear_0.5[01]*", imp)))) {
2993 * These versions have the SSH-2 channel request bug.
2994 * OpenSSH 6.7 and above do not:
2995 * https://bugzilla.mindrot.org/show_bug.cgi?id=1818
2996 * dropbear_0.52 and above do not:
2997 * https://secure.ucc.asn.au/hg/dropbear/rev/cd02449b709c
2999 ssh->remote_bugs |= BUG_SENDS_LATE_REQUEST_REPLY;
3000 logevent("We believe remote version has SSH-2 channel request bug");
3005 * The `software version' part of an SSH version string is required
3006 * to contain no spaces or minus signs.
3008 static void ssh_fix_verstring(char *str)
3010 /* Eat "<protoversion>-". */
3011 while (*str && *str != '-') str++;
3012 assert(*str == '-'); str++;
3014 /* Convert minus signs and spaces in the remaining string into
3017 if (*str == '-' || *str == ' ')
3024 * Send an appropriate SSH version string.
3026 static void ssh_send_verstring(Ssh ssh, const char *protoname, char *svers)
3030 if (ssh->version == 2) {
3032 * Construct a v2 version string.
3034 verstring = dupprintf("%s2.0-%s\015\012", protoname, sshver);
3037 * Construct a v1 version string.
3039 assert(!strcmp(protoname, "SSH-")); /* no v1 bare connection protocol */
3040 verstring = dupprintf("SSH-%s-%s\012",
3041 (ssh_versioncmp(svers, "1.5") <= 0 ?
3046 ssh_fix_verstring(verstring + strlen(protoname));
3048 /* FUZZING make PuTTY insecure, so make live use difficult. */
3052 if (ssh->version == 2) {
3055 * Record our version string.
3057 len = strcspn(verstring, "\015\012");
3058 ssh->v_c = snewn(len + 1, char);
3059 memcpy(ssh->v_c, verstring, len);
3063 logeventf(ssh, "We claim version: %.*s",
3064 strcspn(verstring, "\015\012"), verstring);
3065 s_write(ssh, verstring, strlen(verstring));
3069 static int do_ssh_init(Ssh ssh, unsigned char c)
3071 static const char protoname[] = "SSH-";
3073 struct do_ssh_init_state {
3082 crState(do_ssh_init_state);
3086 /* Search for a line beginning with the protocol name prefix in
3089 for (s->i = 0; protoname[s->i]; s->i++) {
3090 if ((char)c != protoname[s->i]) goto no;
3100 ssh->session_started = TRUE;
3102 s->vstrsize = sizeof(protoname) + 16;
3103 s->vstring = snewn(s->vstrsize, char);
3104 strcpy(s->vstring, protoname);
3105 s->vslen = strlen(protoname);
3108 if (s->vslen >= s->vstrsize - 1) {
3110 s->vstring = sresize(s->vstring, s->vstrsize, char);
3112 s->vstring[s->vslen++] = c;
3115 s->version[s->i] = '\0';
3117 } else if (s->i < sizeof(s->version) - 1)
3118 s->version[s->i++] = c;
3119 } else if (c == '\012')
3121 crReturn(1); /* get another char */
3124 ssh->agentfwd_enabled = FALSE;
3125 ssh->rdpkt2_state.incoming_sequence = 0;
3127 s->vstring[s->vslen] = 0;
3128 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
3129 logeventf(ssh, "Server version: %s", s->vstring);
3130 ssh_detect_bugs(ssh, s->vstring);
3133 * Decide which SSH protocol version to support.
3136 /* Anything strictly below "2.0" means protocol 1 is supported. */
3137 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
3138 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
3139 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
3141 if (conf_get_int(ssh->conf, CONF_sshprot) == 0) {
3143 bombout(("SSH protocol version 1 required by our configuration "
3144 "but not provided by server"));
3147 } else if (conf_get_int(ssh->conf, CONF_sshprot) == 3) {
3149 bombout(("SSH protocol version 2 required by our configuration "
3150 "but server only provides (old, insecure) SSH-1"));
3154 /* No longer support values 1 or 2 for CONF_sshprot */
3155 assert(!"Unexpected value for CONF_sshprot");
3158 if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1))
3163 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
3165 /* Send the version string, if we haven't already */
3166 if (conf_get_int(ssh->conf, CONF_sshprot) != 3)
3167 ssh_send_verstring(ssh, protoname, s->version);
3169 if (ssh->version == 2) {
3172 * Record their version string.
3174 len = strcspn(s->vstring, "\015\012");
3175 ssh->v_s = snewn(len + 1, char);
3176 memcpy(ssh->v_s, s->vstring, len);
3180 * Initialise SSH-2 protocol.
3182 ssh->protocol = ssh2_protocol;
3183 ssh2_protocol_setup(ssh);
3184 ssh->s_rdpkt = ssh2_rdpkt;
3187 * Initialise SSH-1 protocol.
3189 ssh->protocol = ssh1_protocol;
3190 ssh1_protocol_setup(ssh);
3191 ssh->s_rdpkt = ssh1_rdpkt;
3193 if (ssh->version == 2)
3194 do_ssh2_transport(ssh, NULL, -1, NULL);
3196 update_specials_menu(ssh->frontend);
3197 ssh->state = SSH_STATE_BEFORE_SIZE;
3198 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3205 static int do_ssh_connection_init(Ssh ssh, unsigned char c)
3208 * Ordinary SSH begins with the banner "SSH-x.y-...". This is just
3209 * the ssh-connection part, extracted and given a trivial binary
3210 * packet protocol, so we replace 'SSH-' at the start with a new
3211 * name. In proper SSH style (though of course this part of the
3212 * proper SSH protocol _isn't_ subject to this kind of
3213 * DNS-domain-based extension), we define the new name in our
3216 static const char protoname[] =
3217 "SSHCONNECTION@putty.projects.tartarus.org-";
3219 struct do_ssh_connection_init_state {
3227 crState(do_ssh_connection_init_state);
3231 /* Search for a line beginning with the protocol name prefix in
3234 for (s->i = 0; protoname[s->i]; s->i++) {
3235 if ((char)c != protoname[s->i]) goto no;
3245 s->vstrsize = sizeof(protoname) + 16;
3246 s->vstring = snewn(s->vstrsize, char);
3247 strcpy(s->vstring, protoname);
3248 s->vslen = strlen(protoname);
3251 if (s->vslen >= s->vstrsize - 1) {
3253 s->vstring = sresize(s->vstring, s->vstrsize, char);
3255 s->vstring[s->vslen++] = c;
3258 s->version[s->i] = '\0';
3260 } else if (s->i < sizeof(s->version) - 1)
3261 s->version[s->i++] = c;
3262 } else if (c == '\012')
3264 crReturn(1); /* get another char */
3267 ssh->agentfwd_enabled = FALSE;
3268 ssh->rdpkt2_bare_state.incoming_sequence = 0;
3270 s->vstring[s->vslen] = 0;
3271 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
3272 logeventf(ssh, "Server version: %s", s->vstring);
3273 ssh_detect_bugs(ssh, s->vstring);
3276 * Decide which SSH protocol version to support. This is easy in
3277 * bare ssh-connection mode: only 2.0 is legal.
3279 if (ssh_versioncmp(s->version, "2.0") < 0) {
3280 bombout(("Server announces compatibility with SSH-1 in bare ssh-connection protocol"));
3283 if (conf_get_int(ssh->conf, CONF_sshprot) == 0) {
3284 bombout(("Bare ssh-connection protocol cannot be run in SSH-1-only mode"));
3290 logeventf(ssh, "Using bare ssh-connection protocol");
3292 /* Send the version string, if we haven't already */
3293 ssh_send_verstring(ssh, protoname, s->version);
3296 * Initialise bare connection protocol.
3298 ssh->protocol = ssh2_bare_connection_protocol;
3299 ssh2_bare_connection_protocol_setup(ssh);
3300 ssh->s_rdpkt = ssh2_bare_connection_rdpkt;
3302 update_specials_menu(ssh->frontend);
3303 ssh->state = SSH_STATE_BEFORE_SIZE;
3304 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3307 * Get authconn (really just conn) under way.
3309 do_ssh2_authconn(ssh, NULL, 0, NULL);
3316 static void ssh_process_incoming_data(Ssh ssh,
3317 const unsigned char **data, int *datalen)
3319 struct Packet *pktin;
3321 pktin = ssh->s_rdpkt(ssh, data, datalen);
3323 ssh->protocol(ssh, NULL, 0, pktin);
3324 ssh_free_packet(pktin);
3328 static void ssh_queue_incoming_data(Ssh ssh,
3329 const unsigned char **data, int *datalen)
3331 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
3336 static void ssh_process_queued_incoming_data(Ssh ssh)
3339 const unsigned char *data;
3342 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
3343 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
3347 while (!ssh->frozen && len > 0)
3348 ssh_process_incoming_data(ssh, &data, &len);
3351 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
3355 static void ssh_set_frozen(Ssh ssh, int frozen)
3358 sk_set_frozen(ssh->s, frozen);
3359 ssh->frozen = frozen;
3362 static void ssh_gotdata(Ssh ssh, const unsigned char *data, int datalen)
3364 /* Log raw data, if we're in that mode. */
3366 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
3367 0, NULL, NULL, 0, NULL);
3369 crBegin(ssh->ssh_gotdata_crstate);
3372 * To begin with, feed the characters one by one to the
3373 * protocol initialisation / selection function do_ssh_init().
3374 * When that returns 0, we're done with the initial greeting
3375 * exchange and can move on to packet discipline.
3378 int ret; /* need not be kept across crReturn */
3380 crReturnV; /* more data please */
3381 ret = ssh->do_ssh_init(ssh, *data);
3389 * We emerge from that loop when the initial negotiation is
3390 * over and we have selected an s_rdpkt function. Now pass
3391 * everything to s_rdpkt, and then pass the resulting packets
3392 * to the proper protocol handler.
3396 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
3398 ssh_queue_incoming_data(ssh, &data, &datalen);
3399 /* This uses up all data and cannot cause anything interesting
3400 * to happen; indeed, for anything to happen at all, we must
3401 * return, so break out. */
3403 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
3404 /* This uses up some or all data, and may freeze the
3406 ssh_process_queued_incoming_data(ssh);
3408 /* This uses up some or all data, and may freeze the
3410 ssh_process_incoming_data(ssh, &data, &datalen);
3412 /* FIXME this is probably EBW. */
3413 if (ssh->state == SSH_STATE_CLOSED)
3416 /* We're out of data. Go and get some more. */
3422 static int ssh_do_close(Ssh ssh, int notify_exit)
3425 struct ssh_channel *c;
3427 ssh->state = SSH_STATE_CLOSED;
3428 expire_timer_context(ssh);
3433 notify_remote_exit(ssh->frontend);
3438 * Now we must shut down any port- and X-forwarded channels going
3439 * through this connection.
3441 if (ssh->channels) {
3442 while (NULL != (c = index234(ssh->channels, 0))) {
3445 x11_close(c->u.x11.xconn);
3448 case CHAN_SOCKDATA_DORMANT:
3449 pfd_close(c->u.pfd.pf);
3452 del234(ssh->channels, c); /* moving next one to index 0 */
3453 if (ssh->version == 2)
3454 bufchain_clear(&c->v.v2.outbuffer);
3459 * Go through port-forwardings, and close any associated
3460 * listening sockets.
3462 if (ssh->portfwds) {
3463 struct ssh_portfwd *pf;
3464 while (NULL != (pf = index234(ssh->portfwds, 0))) {
3465 /* Dispose of any listening socket. */
3467 pfl_terminate(pf->local);
3468 del234(ssh->portfwds, pf); /* moving next one to index 0 */
3471 freetree234(ssh->portfwds);
3472 ssh->portfwds = NULL;
3476 * Also stop attempting to connection-share.
3478 if (ssh->connshare) {
3479 sharestate_free(ssh->connshare);
3480 ssh->connshare = NULL;
3486 static void ssh_socket_log(Plug plug, int type, SockAddr addr, int port,
3487 const char *error_msg, int error_code)
3489 Ssh ssh = (Ssh) plug;
3492 * While we're attempting connection sharing, don't loudly log
3493 * everything that happens. Real TCP connections need to be logged
3494 * when we _start_ trying to connect, because it might be ages
3495 * before they respond if something goes wrong; but connection
3496 * sharing is local and quick to respond, and it's sufficient to
3497 * simply wait and see whether it worked afterwards.
3500 if (!ssh->attempting_connshare)
3501 backend_socket_log(ssh->frontend, type, addr, port,
3502 error_msg, error_code, ssh->conf,
3503 ssh->session_started);
3506 void ssh_connshare_log(Ssh ssh, int event, const char *logtext,
3507 const char *ds_err, const char *us_err)
3509 if (event == SHARE_NONE) {
3510 /* In this case, 'logtext' is an error message indicating a
3511 * reason why connection sharing couldn't be set up _at all_.
3512 * Failing that, ds_err and us_err indicate why we couldn't be
3513 * a downstream and an upstream respectively. */
3515 logeventf(ssh, "Could not set up connection sharing: %s", logtext);
3518 logeventf(ssh, "Could not set up connection sharing"
3519 " as downstream: %s", ds_err);
3521 logeventf(ssh, "Could not set up connection sharing"
3522 " as upstream: %s", us_err);
3524 } else if (event == SHARE_DOWNSTREAM) {
3525 /* In this case, 'logtext' is a local endpoint address */
3526 logeventf(ssh, "Using existing shared connection at %s", logtext);
3527 /* Also we should mention this in the console window to avoid
3528 * confusing users as to why this window doesn't behave the
3530 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3531 c_write_str(ssh,"Reusing a shared connection to this server.\r\n");
3533 } else if (event == SHARE_UPSTREAM) {
3534 /* In this case, 'logtext' is a local endpoint address too */
3535 logeventf(ssh, "Sharing this connection at %s", logtext);
3539 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
3542 Ssh ssh = (Ssh) plug;
3543 int need_notify = ssh_do_close(ssh, FALSE);
3546 if (!ssh->close_expected)
3547 error_msg = "Server unexpectedly closed network connection";
3549 error_msg = "Server closed network connection";
3552 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
3556 notify_remote_exit(ssh->frontend);
3559 logevent(error_msg);
3560 if (!ssh->close_expected || !ssh->clean_exit)
3561 connection_fatal(ssh->frontend, "%s", error_msg);
3565 static int ssh_receive(Plug plug, int urgent, char *data, int len)
3567 Ssh ssh = (Ssh) plug;
3568 ssh_gotdata(ssh, (unsigned char *)data, len);
3569 if (ssh->state == SSH_STATE_CLOSED) {
3570 ssh_do_close(ssh, TRUE);
3576 static void ssh_sent(Plug plug, int bufsize)
3578 Ssh ssh = (Ssh) plug;
3580 * If the send backlog on the SSH socket itself clears, we
3581 * should unthrottle the whole world if it was throttled.
3583 if (bufsize < SSH_MAX_BACKLOG)
3584 ssh_throttle_all(ssh, 0, bufsize);
3587 static void ssh_hostport_setup(const char *host, int port, Conf *conf,
3588 char **savedhost, int *savedport,
3591 char *loghost = conf_get_str(conf, CONF_loghost);
3593 *loghost_ret = loghost;
3599 tmphost = dupstr(loghost);
3600 *savedport = 22; /* default ssh port */
3603 * A colon suffix on the hostname string also lets us affect
3604 * savedport. (Unless there are multiple colons, in which case
3605 * we assume this is an unbracketed IPv6 literal.)
3607 colon = host_strrchr(tmphost, ':');
3608 if (colon && colon == host_strchr(tmphost, ':')) {
3611 *savedport = atoi(colon);
3614 *savedhost = host_strduptrim(tmphost);
3617 *savedhost = host_strduptrim(host);
3619 port = 22; /* default ssh port */
3624 static int ssh_test_for_upstream(const char *host, int port, Conf *conf)
3630 random_ref(); /* platform may need this to determine share socket name */
3631 ssh_hostport_setup(host, port, conf, &savedhost, &savedport, NULL);
3632 ret = ssh_share_test_for_upstream(savedhost, savedport, conf);
3640 * Connect to specified host and port.
3641 * Returns an error message, or NULL on success.
3642 * Also places the canonical host name into `realhost'. It must be
3643 * freed by the caller.
3645 static const char *connect_to_host(Ssh ssh, const char *host, int port,
3646 char **realhost, int nodelay, int keepalive)
3648 static const struct plug_function_table fn_table = {
3659 int addressfamily, sshprot;
3661 ssh_hostport_setup(host, port, ssh->conf,
3662 &ssh->savedhost, &ssh->savedport, &loghost);
3664 ssh->fn = &fn_table; /* make 'ssh' usable as a Plug */
3667 * Try connection-sharing, in case that means we don't open a
3668 * socket after all. ssh_connection_sharing_init will connect to a
3669 * previously established upstream if it can, and failing that,
3670 * establish a listening socket for _us_ to be the upstream. In
3671 * the latter case it will return NULL just as if it had done
3672 * nothing, because here we only need to care if we're a
3673 * downstream and need to do our connection setup differently.
3675 ssh->connshare = NULL;
3676 ssh->attempting_connshare = TRUE; /* affects socket logging behaviour */
3677 ssh->s = ssh_connection_sharing_init(ssh->savedhost, ssh->savedport,
3678 ssh->conf, ssh, &ssh->connshare);
3679 ssh->attempting_connshare = FALSE;
3680 if (ssh->s != NULL) {
3682 * We are a downstream.
3684 ssh->bare_connection = TRUE;
3685 ssh->do_ssh_init = do_ssh_connection_init;
3686 ssh->fullhostname = NULL;
3687 *realhost = dupstr(host); /* best we can do */
3690 * We're not a downstream, so open a normal socket.
3692 ssh->do_ssh_init = do_ssh_init;
3697 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
3698 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily,
3699 ssh->frontend, "SSH connection");
3700 if ((err = sk_addr_error(addr)) != NULL) {
3704 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3706 ssh->s = new_connection(addr, *realhost, port,
3707 0, 1, nodelay, keepalive,
3708 (Plug) ssh, ssh->conf);
3709 if ((err = sk_socket_error(ssh->s)) != NULL) {
3711 notify_remote_exit(ssh->frontend);
3717 * The SSH version number is always fixed (since we no longer support
3718 * fallback between versions), so set it now, and if it's SSH-2,
3719 * send the version string now too.
3721 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3722 assert(sshprot == 0 || sshprot == 3);
3726 if (sshprot == 3 && !ssh->bare_connection) {
3729 ssh_send_verstring(ssh, "SSH-", NULL);
3733 * loghost, if configured, overrides realhost.
3737 *realhost = dupstr(loghost);
3744 * Throttle or unthrottle the SSH connection.
3746 static void ssh_throttle_conn(Ssh ssh, int adjust)
3748 int old_count = ssh->conn_throttle_count;
3749 ssh->conn_throttle_count += adjust;
3750 assert(ssh->conn_throttle_count >= 0);
3751 if (ssh->conn_throttle_count && !old_count) {
3752 ssh_set_frozen(ssh, 1);
3753 } else if (!ssh->conn_throttle_count && old_count) {
3754 ssh_set_frozen(ssh, 0);
3759 * Throttle or unthrottle _all_ local data streams (for when sends
3760 * on the SSH connection itself back up).
3762 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3765 struct ssh_channel *c;
3767 if (enable == ssh->throttled_all)
3769 ssh->throttled_all = enable;
3770 ssh->overall_bufsize = bufsize;
3773 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3775 case CHAN_MAINSESSION:
3777 * This is treated separately, outside the switch.
3781 x11_override_throttle(c->u.x11.xconn, enable);
3784 /* Agent channels require no buffer management. */
3787 pfd_override_throttle(c->u.pfd.pf, enable);
3793 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3795 Ssh ssh = (Ssh) sshv;
3797 ssh->agent_response = reply;
3798 ssh->agent_response_len = replylen;
3800 if (ssh->version == 1)
3801 do_ssh1_login(ssh, NULL, -1, NULL);
3803 do_ssh2_authconn(ssh, NULL, -1, NULL);
3806 static void ssh_dialog_callback(void *sshv, int ret)
3808 Ssh ssh = (Ssh) sshv;
3810 ssh->user_response = ret;
3812 if (ssh->version == 1)
3813 do_ssh1_login(ssh, NULL, -1, NULL);
3815 do_ssh2_transport(ssh, NULL, -1, NULL);
3818 * This may have unfrozen the SSH connection, so do a
3821 ssh_process_queued_incoming_data(ssh);
3824 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3826 struct ssh_channel *c = (struct ssh_channel *)cv;
3827 const void *sentreply = reply;
3829 c->u.a.outstanding_requests--;
3831 /* Fake SSH_AGENT_FAILURE. */
3832 sentreply = "\0\0\0\1\5";
3835 ssh_send_channel_data(c, sentreply, replylen);
3839 * If we've already seen an incoming EOF but haven't sent an
3840 * outgoing one, this may be the moment to send it.
3842 if (c->u.a.outstanding_requests == 0 && (c->closes & CLOSES_RCVD_EOF))
3843 sshfwd_write_eof(c);
3847 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3848 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3849 * => log `wire_reason'.
3851 static void ssh_disconnect(Ssh ssh, const char *client_reason,
3852 const char *wire_reason,
3853 int code, int clean_exit)
3857 client_reason = wire_reason;
3859 error = dupprintf("Disconnected: %s", client_reason);
3861 error = dupstr("Disconnected");
3863 if (ssh->version == 1) {
3864 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3866 } else if (ssh->version == 2) {
3867 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3868 ssh2_pkt_adduint32(pktout, code);
3869 ssh2_pkt_addstring(pktout, wire_reason);
3870 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3871 ssh2_pkt_send_noqueue(ssh, pktout);
3874 ssh->close_expected = TRUE;
3875 ssh->clean_exit = clean_exit;
3876 ssh_closing((Plug)ssh, error, 0, 0);
3880 int verify_ssh_manual_host_key(Ssh ssh, const char *fingerprint,
3881 const struct ssh_signkey *ssh2keytype,
3884 if (!conf_get_str_nthstrkey(ssh->conf, CONF_ssh_manual_hostkeys, 0)) {
3885 return -1; /* no manual keys configured */
3890 * The fingerprint string we've been given will have things
3891 * like 'ssh-rsa 2048' at the front of it. Strip those off and
3892 * narrow down to just the colon-separated hex block at the
3893 * end of the string.
3895 const char *p = strrchr(fingerprint, ' ');
3896 fingerprint = p ? p+1 : fingerprint;
3897 /* Quick sanity checks, including making sure it's in lowercase */
3898 assert(strlen(fingerprint) == 16*3 - 1);
3899 assert(fingerprint[2] == ':');
3900 assert(fingerprint[strspn(fingerprint, "0123456789abcdef:")] == 0);
3902 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3904 return 1; /* success */
3909 * Construct the base64-encoded public key blob and see if
3912 unsigned char *binblob;
3914 int binlen, atoms, i;
3915 binblob = ssh2keytype->public_blob(ssh2keydata, &binlen);
3916 atoms = (binlen + 2) / 3;
3917 base64blob = snewn(atoms * 4 + 1, char);
3918 for (i = 0; i < atoms; i++)
3919 base64_encode_atom(binblob + 3*i, binlen - 3*i, base64blob + 4*i);
3920 base64blob[atoms * 4] = '\0';
3922 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3925 return 1; /* success */
3934 * Handle the key exchange and user authentication phases.
3936 static int do_ssh1_login(Ssh ssh, const unsigned char *in, int inlen,
3937 struct Packet *pktin)
3940 unsigned char cookie[8], *ptr;
3941 struct MD5Context md5c;
3942 struct do_ssh1_login_state {
3945 unsigned char *rsabuf;
3946 const unsigned char *keystr1, *keystr2;
3947 unsigned long supported_ciphers_mask, supported_auths_mask;
3948 int tried_publickey, tried_agent;
3949 int tis_auth_refused, ccard_auth_refused;
3950 unsigned char session_id[16];
3952 void *publickey_blob;
3953 int publickey_bloblen;
3954 char *publickey_comment;
3955 int privatekey_available, privatekey_encrypted;
3956 prompts_t *cur_prompt;
3959 unsigned char request[5], *response, *p;
3969 struct RSAKey servkey, hostkey;
3971 crState(do_ssh1_login_state);
3978 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
3979 bombout(("Public key packet not received"));
3983 logevent("Received public keys");
3985 ptr = ssh_pkt_getdata(pktin, 8);
3987 bombout(("SSH-1 public key packet stopped before random cookie"));
3990 memcpy(cookie, ptr, 8);
3992 if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) ||
3993 !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) {
3994 bombout(("Failed to read SSH-1 public keys from public key packet"));
3999 * Log the host key fingerprint.
4003 logevent("Host key fingerprint is:");
4004 strcpy(logmsg, " ");
4005 s->hostkey.comment = NULL;
4006 rsa_fingerprint(logmsg + strlen(logmsg),
4007 sizeof(logmsg) - strlen(logmsg), &s->hostkey);
4011 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
4012 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
4013 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
4014 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
4015 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
4017 ssh->v1_local_protoflags =
4018 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
4019 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
4022 MD5Update(&md5c, s->keystr2, s->hostkey.bytes);
4023 MD5Update(&md5c, s->keystr1, s->servkey.bytes);
4024 MD5Update(&md5c, cookie, 8);
4025 MD5Final(s->session_id, &md5c);
4027 for (i = 0; i < 32; i++)
4028 ssh->session_key[i] = random_byte();
4031 * Verify that the `bits' and `bytes' parameters match.
4033 if (s->hostkey.bits > s->hostkey.bytes * 8 ||
4034 s->servkey.bits > s->servkey.bytes * 8) {
4035 bombout(("SSH-1 public keys were badly formatted"));
4039 s->len = (s->hostkey.bytes > s->servkey.bytes ?
4040 s->hostkey.bytes : s->servkey.bytes);
4042 s->rsabuf = snewn(s->len, unsigned char);
4045 * Verify the host key.
4049 * First format the key into a string.
4051 int len = rsastr_len(&s->hostkey);
4052 char fingerprint[100];
4053 char *keystr = snewn(len, char);
4054 rsastr_fmt(keystr, &s->hostkey);
4055 rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey);
4057 /* First check against manually configured host keys. */
4058 s->dlgret = verify_ssh_manual_host_key(ssh, fingerprint, NULL, NULL);
4059 if (s->dlgret == 0) { /* did not match */
4060 bombout(("Host key did not appear in manually configured list"));
4063 } else if (s->dlgret < 0) { /* none configured; use standard handling */
4064 ssh_set_frozen(ssh, 1);
4065 s->dlgret = verify_ssh_host_key(ssh->frontend,
4066 ssh->savedhost, ssh->savedport,
4067 "rsa", keystr, fingerprint,
4068 ssh_dialog_callback, ssh);
4073 if (s->dlgret < 0) {
4077 bombout(("Unexpected data from server while waiting"
4078 " for user host key response"));
4081 } while (pktin || inlen > 0);
4082 s->dlgret = ssh->user_response;
4084 ssh_set_frozen(ssh, 0);
4086 if (s->dlgret == 0) {
4087 ssh_disconnect(ssh, "User aborted at host key verification",
4096 for (i = 0; i < 32; i++) {
4097 s->rsabuf[i] = ssh->session_key[i];
4099 s->rsabuf[i] ^= s->session_id[i];
4102 if (s->hostkey.bytes > s->servkey.bytes) {
4103 ret = rsaencrypt(s->rsabuf, 32, &s->servkey);
4105 ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey);
4107 ret = rsaencrypt(s->rsabuf, 32, &s->hostkey);
4109 ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey);
4112 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
4116 logevent("Encrypted session key");
4119 int cipher_chosen = 0, warn = 0;
4120 const char *cipher_string = NULL;
4122 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
4123 int next_cipher = conf_get_int_int(ssh->conf,
4124 CONF_ssh_cipherlist, i);
4125 if (next_cipher == CIPHER_WARN) {
4126 /* If/when we choose a cipher, warn about it */
4128 } else if (next_cipher == CIPHER_AES) {
4129 /* XXX Probably don't need to mention this. */
4130 logevent("AES not supported in SSH-1, skipping");
4132 switch (next_cipher) {
4133 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
4134 cipher_string = "3DES"; break;
4135 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
4136 cipher_string = "Blowfish"; break;
4137 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
4138 cipher_string = "single-DES"; break;
4140 if (s->supported_ciphers_mask & (1 << s->cipher_type))
4144 if (!cipher_chosen) {
4145 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
4146 bombout(("Server violates SSH-1 protocol by not "
4147 "supporting 3DES encryption"));
4149 /* shouldn't happen */
4150 bombout(("No supported ciphers found"));
4154 /* Warn about chosen cipher if necessary. */
4156 ssh_set_frozen(ssh, 1);
4157 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
4158 ssh_dialog_callback, ssh);
4159 if (s->dlgret < 0) {
4163 bombout(("Unexpected data from server while waiting"
4164 " for user response"));
4167 } while (pktin || inlen > 0);
4168 s->dlgret = ssh->user_response;
4170 ssh_set_frozen(ssh, 0);
4171 if (s->dlgret == 0) {
4172 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
4179 switch (s->cipher_type) {
4180 case SSH_CIPHER_3DES:
4181 logevent("Using 3DES encryption");
4183 case SSH_CIPHER_DES:
4184 logevent("Using single-DES encryption");
4186 case SSH_CIPHER_BLOWFISH:
4187 logevent("Using Blowfish encryption");
4191 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
4192 PKT_CHAR, s->cipher_type,
4193 PKT_DATA, cookie, 8,
4194 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
4195 PKT_DATA, s->rsabuf, s->len,
4196 PKT_INT, ssh->v1_local_protoflags, PKT_END);
4198 logevent("Trying to enable encryption...");
4202 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
4203 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
4205 ssh->v1_cipher_ctx = ssh->cipher->make_context();
4206 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
4207 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
4209 ssh->crcda_ctx = crcda_make_context();
4210 logevent("Installing CRC compensation attack detector");
4212 if (s->servkey.modulus) {
4213 sfree(s->servkey.modulus);
4214 s->servkey.modulus = NULL;
4216 if (s->servkey.exponent) {
4217 sfree(s->servkey.exponent);
4218 s->servkey.exponent = NULL;
4220 if (s->hostkey.modulus) {
4221 sfree(s->hostkey.modulus);
4222 s->hostkey.modulus = NULL;
4224 if (s->hostkey.exponent) {
4225 sfree(s->hostkey.exponent);
4226 s->hostkey.exponent = NULL;
4230 if (pktin->type != SSH1_SMSG_SUCCESS) {
4231 bombout(("Encryption not successfully enabled"));
4235 logevent("Successfully started encryption");
4237 fflush(stdout); /* FIXME eh? */
4239 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
4240 int ret; /* need not be kept over crReturn */
4241 s->cur_prompt = new_prompts(ssh->frontend);
4242 s->cur_prompt->to_server = TRUE;
4243 s->cur_prompt->name = dupstr("SSH login name");
4244 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
4245 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4248 crWaitUntil(!pktin);
4249 ret = get_userpass_input(s->cur_prompt, in, inlen);
4254 * Failed to get a username. Terminate.
4256 free_prompts(s->cur_prompt);
4257 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
4260 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
4261 free_prompts(s->cur_prompt);
4264 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
4266 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
4268 if (flags & FLAG_INTERACTIVE &&
4269 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
4270 c_write_str(ssh, userlog);
4271 c_write_str(ssh, "\r\n");
4279 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
4280 /* We must not attempt PK auth. Pretend we've already tried it. */
4281 s->tried_publickey = s->tried_agent = 1;
4283 s->tried_publickey = s->tried_agent = 0;
4285 s->tis_auth_refused = s->ccard_auth_refused = 0;
4287 * Load the public half of any configured keyfile for later use.
4289 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4290 if (!filename_is_null(s->keyfile)) {
4292 logeventf(ssh, "Reading key file \"%.150s\"",
4293 filename_to_str(s->keyfile));
4294 keytype = key_type(s->keyfile);
4295 if (keytype == SSH_KEYTYPE_SSH1 ||
4296 keytype == SSH_KEYTYPE_SSH1_PUBLIC) {
4298 if (rsakey_pubblob(s->keyfile,
4299 &s->publickey_blob, &s->publickey_bloblen,
4300 &s->publickey_comment, &error)) {
4301 s->privatekey_available = (keytype == SSH_KEYTYPE_SSH1);
4302 if (!s->privatekey_available)
4303 logeventf(ssh, "Key file contains public key only");
4304 s->privatekey_encrypted = rsakey_encrypted(s->keyfile,
4308 logeventf(ssh, "Unable to load key (%s)", error);
4309 msgbuf = dupprintf("Unable to load key file "
4310 "\"%.150s\" (%s)\r\n",
4311 filename_to_str(s->keyfile),
4313 c_write_str(ssh, msgbuf);
4315 s->publickey_blob = NULL;
4319 logeventf(ssh, "Unable to use this key file (%s)",
4320 key_type_to_str(keytype));
4321 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4323 filename_to_str(s->keyfile),
4324 key_type_to_str(keytype));
4325 c_write_str(ssh, msgbuf);
4327 s->publickey_blob = NULL;
4330 s->publickey_blob = NULL;
4332 while (pktin->type == SSH1_SMSG_FAILURE) {
4333 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
4335 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
4337 * Attempt RSA authentication using Pageant.
4343 logevent("Pageant is running. Requesting keys.");
4345 /* Request the keys held by the agent. */
4346 PUT_32BIT(s->request, 1);
4347 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
4348 if (!agent_query(s->request, 5, &r, &s->responselen,
4349 ssh_agent_callback, ssh)) {
4353 bombout(("Unexpected data from server while waiting"
4354 " for agent response"));
4357 } while (pktin || inlen > 0);
4358 r = ssh->agent_response;
4359 s->responselen = ssh->agent_response_len;
4361 s->response = (unsigned char *) r;
4362 if (s->response && s->responselen >= 5 &&
4363 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
4364 s->p = s->response + 5;
4365 s->nkeys = toint(GET_32BIT(s->p));
4367 logeventf(ssh, "Pageant reported negative key count %d",
4372 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
4373 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4374 unsigned char *pkblob = s->p;
4378 do { /* do while (0) to make breaking easy */
4379 n = ssh1_read_bignum
4380 (s->p, toint(s->responselen-(s->p-s->response)),
4385 n = ssh1_read_bignum
4386 (s->p, toint(s->responselen-(s->p-s->response)),
4391 if (s->responselen - (s->p-s->response) < 4)
4393 s->commentlen = toint(GET_32BIT(s->p));
4395 if (s->commentlen < 0 ||
4396 toint(s->responselen - (s->p-s->response)) <
4399 s->commentp = (char *)s->p;
4400 s->p += s->commentlen;
4404 logevent("Pageant key list packet was truncated");
4408 if (s->publickey_blob) {
4409 if (!memcmp(pkblob, s->publickey_blob,
4410 s->publickey_bloblen)) {
4411 logeventf(ssh, "Pageant key #%d matches "
4412 "configured key file", s->keyi);
4413 s->tried_publickey = 1;
4415 /* Skip non-configured key */
4418 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
4419 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4420 PKT_BIGNUM, s->key.modulus, PKT_END);
4422 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4423 logevent("Key refused");
4426 logevent("Received RSA challenge");
4427 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4428 bombout(("Server's RSA challenge was badly formatted"));
4433 char *agentreq, *q, *ret;
4436 len = 1 + 4; /* message type, bit count */
4437 len += ssh1_bignum_length(s->key.exponent);
4438 len += ssh1_bignum_length(s->key.modulus);
4439 len += ssh1_bignum_length(s->challenge);
4440 len += 16; /* session id */
4441 len += 4; /* response format */
4442 agentreq = snewn(4 + len, char);
4443 PUT_32BIT(agentreq, len);
4445 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
4446 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
4448 q += ssh1_write_bignum(q, s->key.exponent);
4449 q += ssh1_write_bignum(q, s->key.modulus);
4450 q += ssh1_write_bignum(q, s->challenge);
4451 memcpy(q, s->session_id, 16);
4453 PUT_32BIT(q, 1); /* response format */
4454 if (!agent_query(agentreq, len + 4, &vret, &retlen,
4455 ssh_agent_callback, ssh)) {
4460 bombout(("Unexpected data from server"
4461 " while waiting for agent"
4465 } while (pktin || inlen > 0);
4466 vret = ssh->agent_response;
4467 retlen = ssh->agent_response_len;
4472 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
4473 logevent("Sending Pageant's response");
4474 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4475 PKT_DATA, ret + 5, 16,
4479 if (pktin->type == SSH1_SMSG_SUCCESS) {
4481 ("Pageant's response accepted");
4482 if (flags & FLAG_VERBOSE) {
4483 c_write_str(ssh, "Authenticated using"
4485 c_write(ssh, s->commentp,
4487 c_write_str(ssh, "\" from agent\r\n");
4492 ("Pageant's response not accepted");
4495 ("Pageant failed to answer challenge");
4499 logevent("No reply received from Pageant");
4502 freebn(s->key.exponent);
4503 freebn(s->key.modulus);
4504 freebn(s->challenge);
4509 if (s->publickey_blob && !s->tried_publickey)
4510 logevent("Configured key file not in Pageant");
4512 logevent("Failed to get reply from Pageant");
4517 if (s->publickey_blob && s->privatekey_available &&
4518 !s->tried_publickey) {
4520 * Try public key authentication with the specified
4523 int got_passphrase; /* need not be kept over crReturn */
4524 if (flags & FLAG_VERBOSE)
4525 c_write_str(ssh, "Trying public key authentication.\r\n");
4526 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4527 logeventf(ssh, "Trying public key \"%s\"",
4528 filename_to_str(s->keyfile));
4529 s->tried_publickey = 1;
4530 got_passphrase = FALSE;
4531 while (!got_passphrase) {
4533 * Get a passphrase, if necessary.
4535 char *passphrase = NULL; /* only written after crReturn */
4537 if (!s->privatekey_encrypted) {
4538 if (flags & FLAG_VERBOSE)
4539 c_write_str(ssh, "No passphrase required.\r\n");
4542 int ret; /* need not be kept over crReturn */
4543 s->cur_prompt = new_prompts(ssh->frontend);
4544 s->cur_prompt->to_server = FALSE;
4545 s->cur_prompt->name = dupstr("SSH key passphrase");
4546 add_prompt(s->cur_prompt,
4547 dupprintf("Passphrase for key \"%.100s\": ",
4548 s->publickey_comment), FALSE);
4549 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4552 crWaitUntil(!pktin);
4553 ret = get_userpass_input(s->cur_prompt, in, inlen);
4557 /* Failed to get a passphrase. Terminate. */
4558 free_prompts(s->cur_prompt);
4559 ssh_disconnect(ssh, NULL, "Unable to authenticate",
4563 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
4564 free_prompts(s->cur_prompt);
4567 * Try decrypting key with passphrase.
4569 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4570 ret = loadrsakey(s->keyfile, &s->key, passphrase,
4573 smemclr(passphrase, strlen(passphrase));
4577 /* Correct passphrase. */
4578 got_passphrase = TRUE;
4579 } else if (ret == 0) {
4580 c_write_str(ssh, "Couldn't load private key from ");
4581 c_write_str(ssh, filename_to_str(s->keyfile));
4582 c_write_str(ssh, " (");
4583 c_write_str(ssh, error);
4584 c_write_str(ssh, ").\r\n");
4585 got_passphrase = FALSE;
4586 break; /* go and try something else */
4587 } else if (ret == -1) {
4588 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
4589 got_passphrase = FALSE;
4592 assert(0 && "unexpected return from loadrsakey()");
4593 got_passphrase = FALSE; /* placate optimisers */
4597 if (got_passphrase) {
4600 * Send a public key attempt.
4602 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4603 PKT_BIGNUM, s->key.modulus, PKT_END);
4606 if (pktin->type == SSH1_SMSG_FAILURE) {
4607 c_write_str(ssh, "Server refused our public key.\r\n");
4608 continue; /* go and try something else */
4610 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4611 bombout(("Bizarre response to offer of public key"));
4617 unsigned char buffer[32];
4618 Bignum challenge, response;
4620 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4621 bombout(("Server's RSA challenge was badly formatted"));
4624 response = rsadecrypt(challenge, &s->key);
4625 freebn(s->key.private_exponent);/* burn the evidence */
4627 for (i = 0; i < 32; i++) {
4628 buffer[i] = bignum_byte(response, 31 - i);
4632 MD5Update(&md5c, buffer, 32);
4633 MD5Update(&md5c, s->session_id, 16);
4634 MD5Final(buffer, &md5c);
4636 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4637 PKT_DATA, buffer, 16, PKT_END);
4644 if (pktin->type == SSH1_SMSG_FAILURE) {
4645 if (flags & FLAG_VERBOSE)
4646 c_write_str(ssh, "Failed to authenticate with"
4647 " our public key.\r\n");
4648 continue; /* go and try something else */
4649 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4650 bombout(("Bizarre response to RSA authentication response"));
4654 break; /* we're through! */
4660 * Otherwise, try various forms of password-like authentication.
4662 s->cur_prompt = new_prompts(ssh->frontend);
4664 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4665 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
4666 !s->tis_auth_refused) {
4667 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
4668 logevent("Requested TIS authentication");
4669 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
4671 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
4672 logevent("TIS authentication declined");
4673 if (flags & FLAG_INTERACTIVE)
4674 c_write_str(ssh, "TIS authentication refused.\r\n");
4675 s->tis_auth_refused = 1;
4680 char *instr_suf, *prompt;
4682 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4684 bombout(("TIS challenge packet was badly formed"));
4687 logevent("Received TIS challenge");
4688 s->cur_prompt->to_server = TRUE;
4689 s->cur_prompt->name = dupstr("SSH TIS authentication");
4690 /* Prompt heuristic comes from OpenSSH */
4691 if (memchr(challenge, '\n', challengelen)) {
4692 instr_suf = dupstr("");
4693 prompt = dupprintf("%.*s", challengelen, challenge);
4695 instr_suf = dupprintf("%.*s", challengelen, challenge);
4696 prompt = dupstr("Response: ");
4698 s->cur_prompt->instruction =
4699 dupprintf("Using TIS authentication.%s%s",
4700 (*instr_suf) ? "\n" : "",
4702 s->cur_prompt->instr_reqd = TRUE;
4703 add_prompt(s->cur_prompt, prompt, FALSE);
4707 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4708 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
4709 !s->ccard_auth_refused) {
4710 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
4711 logevent("Requested CryptoCard authentication");
4712 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
4714 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
4715 logevent("CryptoCard authentication declined");
4716 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4717 s->ccard_auth_refused = 1;
4722 char *instr_suf, *prompt;
4724 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4726 bombout(("CryptoCard challenge packet was badly formed"));
4729 logevent("Received CryptoCard challenge");
4730 s->cur_prompt->to_server = TRUE;
4731 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4732 s->cur_prompt->name_reqd = FALSE;
4733 /* Prompt heuristic comes from OpenSSH */
4734 if (memchr(challenge, '\n', challengelen)) {
4735 instr_suf = dupstr("");
4736 prompt = dupprintf("%.*s", challengelen, challenge);
4738 instr_suf = dupprintf("%.*s", challengelen, challenge);
4739 prompt = dupstr("Response: ");
4741 s->cur_prompt->instruction =
4742 dupprintf("Using CryptoCard authentication.%s%s",
4743 (*instr_suf) ? "\n" : "",
4745 s->cur_prompt->instr_reqd = TRUE;
4746 add_prompt(s->cur_prompt, prompt, FALSE);
4750 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4751 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4752 bombout(("No supported authentication methods available"));
4755 s->cur_prompt->to_server = TRUE;
4756 s->cur_prompt->name = dupstr("SSH password");
4757 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4758 ssh->username, ssh->savedhost),
4763 * Show password prompt, having first obtained it via a TIS
4764 * or CryptoCard exchange if we're doing TIS or CryptoCard
4768 int ret; /* need not be kept over crReturn */
4769 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4772 crWaitUntil(!pktin);
4773 ret = get_userpass_input(s->cur_prompt, in, inlen);
4778 * Failed to get a password (for example
4779 * because one was supplied on the command line
4780 * which has already failed to work). Terminate.
4782 free_prompts(s->cur_prompt);
4783 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4788 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4790 * Defence against traffic analysis: we send a
4791 * whole bunch of packets containing strings of
4792 * different lengths. One of these strings is the
4793 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4794 * The others are all random data in
4795 * SSH1_MSG_IGNORE packets. This way a passive
4796 * listener can't tell which is the password, and
4797 * hence can't deduce the password length.
4799 * Anybody with a password length greater than 16
4800 * bytes is going to have enough entropy in their
4801 * password that a listener won't find it _that_
4802 * much help to know how long it is. So what we'll
4805 * - if password length < 16, we send 15 packets
4806 * containing string lengths 1 through 15
4808 * - otherwise, we let N be the nearest multiple
4809 * of 8 below the password length, and send 8
4810 * packets containing string lengths N through
4811 * N+7. This won't obscure the order of
4812 * magnitude of the password length, but it will
4813 * introduce a bit of extra uncertainty.
4815 * A few servers can't deal with SSH1_MSG_IGNORE, at
4816 * least in this context. For these servers, we need
4817 * an alternative defence. We make use of the fact
4818 * that the password is interpreted as a C string:
4819 * so we can append a NUL, then some random data.
4821 * A few servers can deal with neither SSH1_MSG_IGNORE
4822 * here _nor_ a padded password string.
4823 * For these servers we are left with no defences
4824 * against password length sniffing.
4826 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4827 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4829 * The server can deal with SSH1_MSG_IGNORE, so
4830 * we can use the primary defence.
4832 int bottom, top, pwlen, i;
4835 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4837 bottom = 0; /* zero length passwords are OK! :-) */
4840 bottom = pwlen & ~7;
4844 assert(pwlen >= bottom && pwlen <= top);
4846 randomstr = snewn(top + 1, char);
4848 for (i = bottom; i <= top; i++) {
4850 defer_packet(ssh, s->pwpkt_type,
4851 PKT_STR,s->cur_prompt->prompts[0]->result,
4854 for (j = 0; j < i; j++) {
4856 randomstr[j] = random_byte();
4857 } while (randomstr[j] == '\0');
4859 randomstr[i] = '\0';
4860 defer_packet(ssh, SSH1_MSG_IGNORE,
4861 PKT_STR, randomstr, PKT_END);
4864 logevent("Sending password with camouflage packets");
4865 ssh_pkt_defersend(ssh);
4868 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4870 * The server can't deal with SSH1_MSG_IGNORE
4871 * but can deal with padded passwords, so we
4872 * can use the secondary defence.
4878 len = strlen(s->cur_prompt->prompts[0]->result);
4879 if (len < sizeof(string)) {
4881 strcpy(string, s->cur_prompt->prompts[0]->result);
4882 len++; /* cover the zero byte */
4883 while (len < sizeof(string)) {
4884 string[len++] = (char) random_byte();
4887 ss = s->cur_prompt->prompts[0]->result;
4889 logevent("Sending length-padded password");
4890 send_packet(ssh, s->pwpkt_type,
4891 PKT_INT, len, PKT_DATA, ss, len,
4895 * The server is believed unable to cope with
4896 * any of our password camouflage methods.
4899 len = strlen(s->cur_prompt->prompts[0]->result);
4900 logevent("Sending unpadded password");
4901 send_packet(ssh, s->pwpkt_type,
4903 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4907 send_packet(ssh, s->pwpkt_type,
4908 PKT_STR, s->cur_prompt->prompts[0]->result,
4911 logevent("Sent password");
4912 free_prompts(s->cur_prompt);
4914 if (pktin->type == SSH1_SMSG_FAILURE) {
4915 if (flags & FLAG_VERBOSE)
4916 c_write_str(ssh, "Access denied\r\n");
4917 logevent("Authentication refused");
4918 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4919 bombout(("Strange packet received, type %d", pktin->type));
4925 if (s->publickey_blob) {
4926 sfree(s->publickey_blob);
4927 sfree(s->publickey_comment);
4930 logevent("Authentication successful");
4935 static void ssh_channel_try_eof(struct ssh_channel *c)
4938 assert(c->pending_eof); /* precondition for calling us */
4940 return; /* can't close: not even opened yet */
4941 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4942 return; /* can't send EOF: pending outgoing data */
4944 c->pending_eof = FALSE; /* we're about to send it */
4945 if (ssh->version == 1) {
4946 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4948 c->closes |= CLOSES_SENT_EOF;
4950 struct Packet *pktout;
4951 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4952 ssh2_pkt_adduint32(pktout, c->remoteid);
4953 ssh2_pkt_send(ssh, pktout);
4954 c->closes |= CLOSES_SENT_EOF;
4955 ssh2_channel_check_close(c);
4959 Conf *sshfwd_get_conf(struct ssh_channel *c)
4965 void sshfwd_write_eof(struct ssh_channel *c)
4969 if (ssh->state == SSH_STATE_CLOSED)
4972 if (c->closes & CLOSES_SENT_EOF)
4975 c->pending_eof = TRUE;
4976 ssh_channel_try_eof(c);
4979 void sshfwd_unclean_close(struct ssh_channel *c, const char *err)
4983 if (ssh->state == SSH_STATE_CLOSED)
4988 x11_close(c->u.x11.xconn);
4989 logeventf(ssh, "Forwarded X11 connection terminated due to local "
4993 case CHAN_SOCKDATA_DORMANT:
4994 pfd_close(c->u.pfd.pf);
4995 logeventf(ssh, "Forwarded port closed due to local error: %s", err);
4998 c->type = CHAN_ZOMBIE;
4999 c->pending_eof = FALSE; /* this will confuse a zombie channel */
5001 ssh2_channel_check_close(c);
5004 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
5008 if (ssh->state == SSH_STATE_CLOSED)
5011 return ssh_send_channel_data(c, buf, len);
5014 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
5019 if (ssh->state == SSH_STATE_CLOSED)
5022 if (ssh->version == 1) {
5023 buflimit = SSH1_BUFFER_LIMIT;
5025 buflimit = c->v.v2.locmaxwin;
5026 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
5028 if (c->throttling_conn && bufsize <= buflimit) {
5029 c->throttling_conn = 0;
5030 ssh_throttle_conn(ssh, -1);
5034 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
5036 struct queued_handler *qh = ssh->qhead;
5040 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
5043 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
5044 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
5047 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
5048 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
5052 ssh->qhead = qh->next;
5054 if (ssh->qhead->msg1 > 0) {
5055 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
5056 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
5058 if (ssh->qhead->msg2 > 0) {
5059 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
5060 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
5063 ssh->qhead = ssh->qtail = NULL;
5066 qh->handler(ssh, pktin, qh->ctx);
5071 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
5072 chandler_fn_t handler, void *ctx)
5074 struct queued_handler *qh;
5076 qh = snew(struct queued_handler);
5079 qh->handler = handler;
5083 if (ssh->qtail == NULL) {
5087 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
5088 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
5091 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
5092 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
5095 ssh->qtail->next = qh;
5100 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
5102 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
5104 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
5105 SSH2_MSG_REQUEST_SUCCESS)) {
5106 logeventf(ssh, "Remote port forwarding from %s enabled",
5109 logeventf(ssh, "Remote port forwarding from %s refused",
5112 rpf = del234(ssh->rportfwds, pf);
5114 pf->pfrec->remote = NULL;
5119 int ssh_alloc_sharing_rportfwd(Ssh ssh, const char *shost, int sport,
5122 struct ssh_rportfwd *pf = snew(struct ssh_rportfwd);
5125 pf->share_ctx = share_ctx;
5126 pf->shost = dupstr(shost);
5128 pf->sportdesc = NULL;
5129 if (!ssh->rportfwds) {
5130 assert(ssh->version == 2);
5131 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5133 if (add234(ssh->rportfwds, pf) != pf) {
5141 static void ssh_sharing_global_request_response(Ssh ssh, struct Packet *pktin,
5144 share_got_pkt_from_server(ctx, pktin->type,
5145 pktin->body, pktin->length);
5148 void ssh_sharing_queue_global_request(Ssh ssh, void *share_ctx)
5150 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, SSH2_MSG_REQUEST_FAILURE,
5151 ssh_sharing_global_request_response, share_ctx);
5154 static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
5156 struct ssh_portfwd *epf;
5160 if (!ssh->portfwds) {
5161 ssh->portfwds = newtree234(ssh_portcmp);
5164 * Go through the existing port forwardings and tag them
5165 * with status==DESTROY. Any that we want to keep will be
5166 * re-enabled (status==KEEP) as we go through the
5167 * configuration and find out which bits are the same as
5170 struct ssh_portfwd *epf;
5172 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5173 epf->status = DESTROY;
5176 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
5178 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
5179 char *kp, *kp2, *vp, *vp2;
5180 char address_family, type;
5181 int sport,dport,sserv,dserv;
5182 char *sports, *dports, *saddr, *host;
5186 address_family = 'A';
5188 if (*kp == 'A' || *kp == '4' || *kp == '6')
5189 address_family = *kp++;
5190 if (*kp == 'L' || *kp == 'R')
5193 if ((kp2 = host_strchr(kp, ':')) != NULL) {
5195 * There's a colon in the middle of the source port
5196 * string, which means that the part before it is
5197 * actually a source address.
5199 char *saddr_tmp = dupprintf("%.*s", (int)(kp2 - kp), kp);
5200 saddr = host_strduptrim(saddr_tmp);
5207 sport = atoi(sports);
5211 sport = net_service_lookup(sports);
5213 logeventf(ssh, "Service lookup failed for source"
5214 " port \"%s\"", sports);
5218 if (type == 'L' && !strcmp(val, "D")) {
5219 /* dynamic forwarding */
5226 /* ordinary forwarding */
5228 vp2 = vp + host_strcspn(vp, ":");
5229 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
5233 dport = atoi(dports);
5237 dport = net_service_lookup(dports);
5239 logeventf(ssh, "Service lookup failed for destination"
5240 " port \"%s\"", dports);
5245 if (sport && dport) {
5246 /* Set up a description of the source port. */
5247 struct ssh_portfwd *pfrec, *epfrec;
5249 pfrec = snew(struct ssh_portfwd);
5251 pfrec->saddr = saddr;
5252 pfrec->sserv = sserv ? dupstr(sports) : NULL;
5253 pfrec->sport = sport;
5254 pfrec->daddr = host;
5255 pfrec->dserv = dserv ? dupstr(dports) : NULL;
5256 pfrec->dport = dport;
5257 pfrec->local = NULL;
5258 pfrec->remote = NULL;
5259 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
5260 address_family == '6' ? ADDRTYPE_IPV6 :
5263 epfrec = add234(ssh->portfwds, pfrec);
5264 if (epfrec != pfrec) {
5265 if (epfrec->status == DESTROY) {
5267 * We already have a port forwarding up and running
5268 * with precisely these parameters. Hence, no need
5269 * to do anything; simply re-tag the existing one
5272 epfrec->status = KEEP;
5275 * Anything else indicates that there was a duplicate
5276 * in our input, which we'll silently ignore.
5278 free_portfwd(pfrec);
5280 pfrec->status = CREATE;
5289 * Now go through and destroy any port forwardings which were
5292 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5293 if (epf->status == DESTROY) {
5296 message = dupprintf("%s port forwarding from %s%s%d",
5297 epf->type == 'L' ? "local" :
5298 epf->type == 'R' ? "remote" : "dynamic",
5299 epf->saddr ? epf->saddr : "",
5300 epf->saddr ? ":" : "",
5303 if (epf->type != 'D') {
5304 char *msg2 = dupprintf("%s to %s:%d", message,
5305 epf->daddr, epf->dport);
5310 logeventf(ssh, "Cancelling %s", message);
5313 /* epf->remote or epf->local may be NULL if setting up a
5314 * forwarding failed. */
5316 struct ssh_rportfwd *rpf = epf->remote;
5317 struct Packet *pktout;
5320 * Cancel the port forwarding at the server
5323 if (ssh->version == 1) {
5325 * We cannot cancel listening ports on the
5326 * server side in SSH-1! There's no message
5327 * to support it. Instead, we simply remove
5328 * the rportfwd record from the local end
5329 * so that any connections the server tries
5330 * to make on it are rejected.
5333 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5334 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
5335 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
5337 ssh2_pkt_addstring(pktout, epf->saddr);
5338 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5339 /* XXX: rport_acceptall may not represent
5340 * what was used to open the original connection,
5341 * since it's reconfigurable. */
5342 ssh2_pkt_addstring(pktout, "");
5344 ssh2_pkt_addstring(pktout, "localhost");
5346 ssh2_pkt_adduint32(pktout, epf->sport);
5347 ssh2_pkt_send(ssh, pktout);
5350 del234(ssh->rportfwds, rpf);
5352 } else if (epf->local) {
5353 pfl_terminate(epf->local);
5356 delpos234(ssh->portfwds, i);
5358 i--; /* so we don't skip one in the list */
5362 * And finally, set up any new port forwardings (status==CREATE).
5364 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5365 if (epf->status == CREATE) {
5366 char *sportdesc, *dportdesc;
5367 sportdesc = dupprintf("%s%s%s%s%d%s",
5368 epf->saddr ? epf->saddr : "",
5369 epf->saddr ? ":" : "",
5370 epf->sserv ? epf->sserv : "",
5371 epf->sserv ? "(" : "",
5373 epf->sserv ? ")" : "");
5374 if (epf->type == 'D') {
5377 dportdesc = dupprintf("%s:%s%s%d%s",
5379 epf->dserv ? epf->dserv : "",
5380 epf->dserv ? "(" : "",
5382 epf->dserv ? ")" : "");
5385 if (epf->type == 'L') {
5386 char *err = pfl_listen(epf->daddr, epf->dport,
5387 epf->saddr, epf->sport,
5388 ssh, conf, &epf->local,
5389 epf->addressfamily);
5391 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
5392 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5393 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5394 sportdesc, dportdesc,
5395 err ? " failed: " : "", err ? err : "");
5398 } else if (epf->type == 'D') {
5399 char *err = pfl_listen(NULL, -1, epf->saddr, epf->sport,
5400 ssh, conf, &epf->local,
5401 epf->addressfamily);
5403 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
5404 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5405 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5407 err ? " failed: " : "", err ? err : "");
5412 struct ssh_rportfwd *pf;
5415 * Ensure the remote port forwardings tree exists.
5417 if (!ssh->rportfwds) {
5418 if (ssh->version == 1)
5419 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
5421 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5424 pf = snew(struct ssh_rportfwd);
5425 pf->share_ctx = NULL;
5426 pf->dhost = dupstr(epf->daddr);
5427 pf->dport = epf->dport;
5429 pf->shost = dupstr(epf->saddr);
5430 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5431 pf->shost = dupstr("");
5433 pf->shost = dupstr("localhost");
5435 pf->sport = epf->sport;
5436 if (add234(ssh->rportfwds, pf) != pf) {
5437 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
5438 epf->daddr, epf->dport);
5441 logeventf(ssh, "Requesting remote port %s"
5442 " forward to %s", sportdesc, dportdesc);
5444 pf->sportdesc = sportdesc;
5449 if (ssh->version == 1) {
5450 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
5451 PKT_INT, epf->sport,
5452 PKT_STR, epf->daddr,
5453 PKT_INT, epf->dport,
5455 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
5457 ssh_rportfwd_succfail, pf);
5459 struct Packet *pktout;
5460 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5461 ssh2_pkt_addstring(pktout, "tcpip-forward");
5462 ssh2_pkt_addbool(pktout, 1);/* want reply */
5463 ssh2_pkt_addstring(pktout, pf->shost);
5464 ssh2_pkt_adduint32(pktout, pf->sport);
5465 ssh2_pkt_send(ssh, pktout);
5467 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
5468 SSH2_MSG_REQUEST_FAILURE,
5469 ssh_rportfwd_succfail, pf);
5478 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
5481 int stringlen, bufsize;
5483 ssh_pkt_getstring(pktin, &string, &stringlen);
5484 if (string == NULL) {
5485 bombout(("Incoming terminal data packet was badly formed"));
5489 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
5491 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
5492 ssh->v1_stdout_throttling = 1;
5493 ssh_throttle_conn(ssh, +1);
5497 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
5499 /* Remote side is trying to open a channel to talk to our
5500 * X-Server. Give them back a local channel number. */
5501 struct ssh_channel *c;
5502 int remoteid = ssh_pkt_getuint32(pktin);
5504 logevent("Received X11 connect request");
5505 /* Refuse if X11 forwarding is disabled. */
5506 if (!ssh->X11_fwd_enabled) {
5507 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5508 PKT_INT, remoteid, PKT_END);
5509 logevent("Rejected X11 connect request");
5511 c = snew(struct ssh_channel);
5514 c->u.x11.xconn = x11_init(ssh->x11authtree, c, NULL, -1);
5515 c->remoteid = remoteid;
5516 c->halfopen = FALSE;
5517 c->localid = alloc_channel_id(ssh);
5519 c->pending_eof = FALSE;
5520 c->throttling_conn = 0;
5521 c->type = CHAN_X11; /* identify channel type */
5522 add234(ssh->channels, c);
5523 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5524 PKT_INT, c->remoteid, PKT_INT,
5525 c->localid, PKT_END);
5526 logevent("Opened X11 forward channel");
5530 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
5532 /* Remote side is trying to open a channel to talk to our
5533 * agent. Give them back a local channel number. */
5534 struct ssh_channel *c;
5535 int remoteid = ssh_pkt_getuint32(pktin);
5537 /* Refuse if agent forwarding is disabled. */
5538 if (!ssh->agentfwd_enabled) {
5539 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5540 PKT_INT, remoteid, PKT_END);
5542 c = snew(struct ssh_channel);
5544 c->remoteid = remoteid;
5545 c->halfopen = FALSE;
5546 c->localid = alloc_channel_id(ssh);
5548 c->pending_eof = FALSE;
5549 c->throttling_conn = 0;
5550 c->type = CHAN_AGENT; /* identify channel type */
5551 c->u.a.lensofar = 0;
5552 c->u.a.message = NULL;
5553 c->u.a.outstanding_requests = 0;
5554 add234(ssh->channels, c);
5555 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5556 PKT_INT, c->remoteid, PKT_INT, c->localid,
5561 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
5563 /* Remote side is trying to open a channel to talk to a
5564 * forwarded port. Give them back a local channel number. */
5565 struct ssh_rportfwd pf, *pfp;
5571 remoteid = ssh_pkt_getuint32(pktin);
5572 ssh_pkt_getstring(pktin, &host, &hostsize);
5573 port = ssh_pkt_getuint32(pktin);
5575 pf.dhost = dupprintf("%.*s", hostsize, NULLTOEMPTY(host));
5577 pfp = find234(ssh->rportfwds, &pf, NULL);
5580 logeventf(ssh, "Rejected remote port open request for %s:%d",
5582 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5583 PKT_INT, remoteid, PKT_END);
5585 struct ssh_channel *c = snew(struct ssh_channel);
5588 logeventf(ssh, "Received remote port open request for %s:%d",
5590 err = pfd_connect(&c->u.pfd.pf, pf.dhost, port,
5591 c, ssh->conf, pfp->pfrec->addressfamily);
5593 logeventf(ssh, "Port open failed: %s", err);
5596 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5597 PKT_INT, remoteid, PKT_END);
5599 c->remoteid = remoteid;
5600 c->halfopen = FALSE;
5601 c->localid = alloc_channel_id(ssh);
5603 c->pending_eof = FALSE;
5604 c->throttling_conn = 0;
5605 c->type = CHAN_SOCKDATA; /* identify channel type */
5606 add234(ssh->channels, c);
5607 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5608 PKT_INT, c->remoteid, PKT_INT,
5609 c->localid, PKT_END);
5610 logevent("Forwarded port opened successfully");
5617 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5619 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5620 unsigned int localid = ssh_pkt_getuint32(pktin);
5621 struct ssh_channel *c;
5623 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5624 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5625 c->remoteid = localid;
5626 c->halfopen = FALSE;
5627 c->type = CHAN_SOCKDATA;
5628 c->throttling_conn = 0;
5629 pfd_confirm(c->u.pfd.pf);
5632 if (c && c->pending_eof) {
5634 * We have a pending close on this channel,
5635 * which we decided on before the server acked
5636 * the channel open. So now we know the
5637 * remoteid, we can close it again.
5639 ssh_channel_try_eof(c);
5643 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5645 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5646 struct ssh_channel *c;
5648 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5649 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5650 logevent("Forwarded connection refused by server");
5651 pfd_close(c->u.pfd.pf);
5652 del234(ssh->channels, c);
5657 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
5659 /* Remote side closes a channel. */
5660 unsigned i = ssh_pkt_getuint32(pktin);
5661 struct ssh_channel *c;
5662 c = find234(ssh->channels, &i, ssh_channelfind);
5663 if (c && !c->halfopen) {
5665 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
5666 !(c->closes & CLOSES_RCVD_EOF)) {
5668 * Received CHANNEL_CLOSE, which we translate into
5671 int send_close = FALSE;
5673 c->closes |= CLOSES_RCVD_EOF;
5678 x11_send_eof(c->u.x11.xconn);
5684 pfd_send_eof(c->u.pfd.pf);
5693 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
5694 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
5696 c->closes |= CLOSES_SENT_EOF;
5700 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
5701 !(c->closes & CLOSES_RCVD_CLOSE)) {
5703 if (!(c->closes & CLOSES_SENT_EOF)) {
5704 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
5705 " for which we never sent CHANNEL_CLOSE\n", i));
5708 c->closes |= CLOSES_RCVD_CLOSE;
5711 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
5712 !(c->closes & CLOSES_SENT_CLOSE)) {
5713 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
5714 PKT_INT, c->remoteid, PKT_END);
5715 c->closes |= CLOSES_SENT_CLOSE;
5718 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5719 ssh_channel_destroy(c);
5721 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5722 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
5723 "_CONFIRMATION", c ? "half-open" : "nonexistent",
5729 * Handle incoming data on an SSH-1 or SSH-2 agent-forwarding channel.
5731 static int ssh_agent_channel_data(struct ssh_channel *c, char *data,
5734 while (length > 0) {
5735 if (c->u.a.lensofar < 4) {
5736 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)length);
5737 memcpy(c->u.a.msglen + c->u.a.lensofar, data, l);
5740 c->u.a.lensofar += l;
5742 if (c->u.a.lensofar == 4) {
5743 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
5744 c->u.a.message = snewn(c->u.a.totallen, unsigned char);
5745 memcpy(c->u.a.message, c->u.a.msglen, 4);
5747 if (c->u.a.lensofar >= 4 && length > 0) {
5748 unsigned int l = min(c->u.a.totallen - c->u.a.lensofar,
5750 memcpy(c->u.a.message + c->u.a.lensofar, data, l);
5753 c->u.a.lensofar += l;
5755 if (c->u.a.lensofar == c->u.a.totallen) {
5758 c->u.a.outstanding_requests++;
5759 if (agent_query(c->u.a.message, c->u.a.totallen, &reply, &replylen,
5760 ssh_agentf_callback, c))
5761 ssh_agentf_callback(c, reply, replylen);
5762 sfree(c->u.a.message);
5763 c->u.a.message = NULL;
5764 c->u.a.lensofar = 0;
5767 return 0; /* agent channels never back up */
5770 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5772 /* Data sent down one of our channels. */
5773 int i = ssh_pkt_getuint32(pktin);
5776 struct ssh_channel *c;
5778 ssh_pkt_getstring(pktin, &p, &len);
5780 c = find234(ssh->channels, &i, ssh_channelfind);
5785 bufsize = x11_send(c->u.x11.xconn, p, len);
5788 bufsize = pfd_send(c->u.pfd.pf, p, len);
5791 bufsize = ssh_agent_channel_data(c, p, len);
5794 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5795 c->throttling_conn = 1;
5796 ssh_throttle_conn(ssh, +1);
5801 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5803 ssh->exitcode = ssh_pkt_getuint32(pktin);
5804 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5805 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5807 * In case `helpful' firewalls or proxies tack
5808 * extra human-readable text on the end of the
5809 * session which we might mistake for another
5810 * encrypted packet, we close the session once
5811 * we've sent EXIT_CONFIRMATION.
5813 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5816 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5817 static void ssh1_send_ttymode(void *data, char *mode, char *val)
5819 struct Packet *pktout = (struct Packet *)data;
5821 unsigned int arg = 0;
5822 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5823 if (i == lenof(ssh_ttymodes)) return;
5824 switch (ssh_ttymodes[i].type) {
5826 arg = ssh_tty_parse_specchar(val);
5829 arg = ssh_tty_parse_boolean(val);
5832 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5833 ssh2_pkt_addbyte(pktout, arg);
5836 int ssh_agent_forwarding_permitted(Ssh ssh)
5838 return conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists();
5841 static void do_ssh1_connection(Ssh ssh, const unsigned char *in, int inlen,
5842 struct Packet *pktin)
5844 crBegin(ssh->do_ssh1_connection_crstate);
5846 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5847 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5848 ssh1_smsg_stdout_stderr_data;
5850 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5851 ssh1_msg_channel_open_confirmation;
5852 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5853 ssh1_msg_channel_open_failure;
5854 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5855 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5856 ssh1_msg_channel_close;
5857 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5858 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5860 if (ssh_agent_forwarding_permitted(ssh)) {
5861 logevent("Requesting agent forwarding");
5862 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5866 if (pktin->type != SSH1_SMSG_SUCCESS
5867 && pktin->type != SSH1_SMSG_FAILURE) {
5868 bombout(("Protocol confusion"));
5870 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5871 logevent("Agent forwarding refused");
5873 logevent("Agent forwarding enabled");
5874 ssh->agentfwd_enabled = TRUE;
5875 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5879 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
5881 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5883 if (!ssh->x11disp) {
5884 /* FIXME: return an error message from x11_setup_display */
5885 logevent("X11 forwarding not enabled: unable to"
5886 " initialise X display");
5888 ssh->x11auth = x11_invent_fake_auth
5889 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
5890 ssh->x11auth->disp = ssh->x11disp;
5892 logevent("Requesting X11 forwarding");
5893 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5894 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5895 PKT_STR, ssh->x11auth->protoname,
5896 PKT_STR, ssh->x11auth->datastring,
5897 PKT_INT, ssh->x11disp->screennum,
5900 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5901 PKT_STR, ssh->x11auth->protoname,
5902 PKT_STR, ssh->x11auth->datastring,
5908 if (pktin->type != SSH1_SMSG_SUCCESS
5909 && pktin->type != SSH1_SMSG_FAILURE) {
5910 bombout(("Protocol confusion"));
5912 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5913 logevent("X11 forwarding refused");
5915 logevent("X11 forwarding enabled");
5916 ssh->X11_fwd_enabled = TRUE;
5917 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5922 ssh_setup_portfwd(ssh, ssh->conf);
5923 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5925 if (!conf_get_int(ssh->conf, CONF_nopty)) {
5927 /* Unpick the terminal-speed string. */
5928 /* XXX perhaps we should allow no speeds to be sent. */
5929 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5930 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
5931 /* Send the pty request. */
5932 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5933 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
5934 ssh_pkt_adduint32(pkt, ssh->term_height);
5935 ssh_pkt_adduint32(pkt, ssh->term_width);
5936 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5937 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5938 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
5939 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5940 ssh_pkt_adduint32(pkt, ssh->ispeed);
5941 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5942 ssh_pkt_adduint32(pkt, ssh->ospeed);
5943 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5945 ssh->state = SSH_STATE_INTERMED;
5949 if (pktin->type != SSH1_SMSG_SUCCESS
5950 && pktin->type != SSH1_SMSG_FAILURE) {
5951 bombout(("Protocol confusion"));
5953 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5954 c_write_str(ssh, "Server refused to allocate pty\r\n");
5955 ssh->editing = ssh->echoing = 1;
5957 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5958 ssh->ospeed, ssh->ispeed);
5959 ssh->got_pty = TRUE;
5962 ssh->editing = ssh->echoing = 1;
5965 if (conf_get_int(ssh->conf, CONF_compression)) {
5966 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5970 if (pktin->type != SSH1_SMSG_SUCCESS
5971 && pktin->type != SSH1_SMSG_FAILURE) {
5972 bombout(("Protocol confusion"));
5974 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5975 c_write_str(ssh, "Server refused to compress\r\n");
5977 logevent("Started compression");
5978 ssh->v1_compressing = TRUE;
5979 ssh->cs_comp_ctx = zlib_compress_init();
5980 logevent("Initialised zlib (RFC1950) compression");
5981 ssh->sc_comp_ctx = zlib_decompress_init();
5982 logevent("Initialised zlib (RFC1950) decompression");
5986 * Start the shell or command.
5988 * Special case: if the first-choice command is an SSH-2
5989 * subsystem (hence not usable here) and the second choice
5990 * exists, we fall straight back to that.
5993 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
5995 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
5996 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
5997 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
5998 ssh->fallback_cmd = TRUE;
6001 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
6003 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
6004 logevent("Started session");
6007 ssh->state = SSH_STATE_SESSION;
6008 if (ssh->size_needed)
6009 ssh_size(ssh, ssh->term_width, ssh->term_height);
6010 if (ssh->eof_needed)
6011 ssh_special(ssh, TS_EOF);
6014 ldisc_echoedit_update(ssh->ldisc); /* cause ldisc to notice changes */
6016 ssh->channels = newtree234(ssh_channelcmp);
6020 * By this point, most incoming packets are already being
6021 * handled by the dispatch table, and we need only pay
6022 * attention to the unusual ones.
6027 if (pktin->type == SSH1_SMSG_SUCCESS) {
6028 /* may be from EXEC_SHELL on some servers */
6029 } else if (pktin->type == SSH1_SMSG_FAILURE) {
6030 /* may be from EXEC_SHELL on some servers
6031 * if no pty is available or in other odd cases. Ignore */
6033 bombout(("Strange packet received: type %d", pktin->type));
6038 int len = min(inlen, 512);
6039 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
6040 PKT_INT, len, PKT_DATA, in, len,
6052 * Handle the top-level SSH-2 protocol.
6054 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
6059 ssh_pkt_getstring(pktin, &msg, &msglen);
6060 logeventf(ssh, "Remote debug message: %.*s", msglen, NULLTOEMPTY(msg));
6063 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
6065 /* log reason code in disconnect message */
6069 ssh_pkt_getstring(pktin, &msg, &msglen);
6070 bombout(("Server sent disconnect message:\n\"%.*s\"",
6071 msglen, NULLTOEMPTY(msg)));
6074 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
6076 /* Do nothing, because we're ignoring it! Duhh. */
6079 static void ssh1_protocol_setup(Ssh ssh)
6084 * Most messages are handled by the coroutines.
6086 for (i = 0; i < 256; i++)
6087 ssh->packet_dispatch[i] = NULL;
6090 * These special message types we install handlers for.
6092 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
6093 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
6094 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
6097 static void ssh1_protocol(Ssh ssh, const void *vin, int inlen,
6098 struct Packet *pktin)
6100 const unsigned char *in = (const unsigned char *)vin;
6101 if (ssh->state == SSH_STATE_CLOSED)
6104 if (pktin && ssh->packet_dispatch[pktin->type]) {
6105 ssh->packet_dispatch[pktin->type](ssh, pktin);
6109 if (!ssh->protocol_initial_phase_done) {
6110 if (do_ssh1_login(ssh, in, inlen, pktin))
6111 ssh->protocol_initial_phase_done = TRUE;
6116 do_ssh1_connection(ssh, in, inlen, pktin);
6120 * Utility routines for decoding comma-separated strings in KEXINIT.
6122 static int first_in_commasep_string(char const *needle, char const *haystack,
6126 if (!needle || !haystack) /* protect against null pointers */
6128 needlen = strlen(needle);
6130 if (haylen >= needlen && /* haystack is long enough */
6131 !memcmp(needle, haystack, needlen) && /* initial match */
6132 (haylen == needlen || haystack[needlen] == ',')
6133 /* either , or EOS follows */
6139 static int in_commasep_string(char const *needle, char const *haystack,
6144 if (!needle || !haystack) /* protect against null pointers */
6147 * Is it at the start of the string?
6149 if (first_in_commasep_string(needle, haystack, haylen))
6152 * If not, search for the next comma and resume after that.
6153 * If no comma found, terminate.
6155 p = memchr(haystack, ',', haylen);
6157 /* + 1 to skip over comma */
6158 return in_commasep_string(needle, p + 1, haylen - (p + 1 - haystack));
6162 * Add a value to the comma-separated string at the end of the packet.
6164 static void ssh2_pkt_addstring_commasep(struct Packet *pkt, const char *data)
6166 if (pkt->length - pkt->savedpos > 0)
6167 ssh_pkt_addstring_str(pkt, ",");
6168 ssh_pkt_addstring_str(pkt, data);
6173 * SSH-2 key derivation (RFC 4253 section 7.2).
6175 static unsigned char *ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
6176 char chr, int keylen)
6178 const struct ssh_hash *h = ssh->kex->hash;
6186 /* Round up to the next multiple of hash length. */
6187 keylen_padded = ((keylen + h->hlen - 1) / h->hlen) * h->hlen;
6189 key = snewn(keylen_padded, unsigned char);
6191 /* First hlen bytes. */
6193 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6194 hash_mpint(h, s, K);
6195 h->bytes(s, H, h->hlen);
6196 h->bytes(s, &chr, 1);
6197 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
6200 /* Subsequent blocks of hlen bytes. */
6201 if (keylen_padded > h->hlen) {
6205 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6206 hash_mpint(h, s, K);
6207 h->bytes(s, H, h->hlen);
6209 for (offset = h->hlen; offset < keylen_padded; offset += h->hlen) {
6210 h->bytes(s, key + offset - h->hlen, h->hlen);
6212 h->final(s2, key + offset);
6218 /* Now clear any extra bytes of key material beyond the length
6219 * we're officially returning, because the caller won't know to
6221 if (keylen_padded > keylen)
6222 smemclr(key + keylen, keylen_padded - keylen);
6228 * Structure for constructing KEXINIT algorithm lists.
6230 #define MAXKEXLIST 16
6231 struct kexinit_algorithm {
6235 const struct ssh_kex *kex;
6239 const struct ssh_signkey *hostkey;
6243 const struct ssh2_cipher *cipher;
6247 const struct ssh_mac *mac;
6250 const struct ssh_compress *comp;
6255 * Find a slot in a KEXINIT algorithm list to use for a new algorithm.
6256 * If the algorithm is already in the list, return a pointer to its
6257 * entry, otherwise return an entry from the end of the list.
6258 * This assumes that every time a particular name is passed in, it
6259 * comes from the same string constant. If this isn't true, this
6260 * function may need to be rewritten to use strcmp() instead.
6262 static struct kexinit_algorithm *ssh2_kexinit_addalg(struct kexinit_algorithm
6263 *list, const char *name)
6267 for (i = 0; i < MAXKEXLIST; i++)
6268 if (list[i].name == NULL || list[i].name == name) {
6269 list[i].name = name;
6272 assert(!"No space in KEXINIT list");
6277 * Handle the SSH-2 transport layer.
6279 static void do_ssh2_transport(Ssh ssh, const void *vin, int inlen,
6280 struct Packet *pktin)
6282 const unsigned char *in = (const unsigned char *)vin;
6284 KEXLIST_KEX, KEXLIST_HOSTKEY, KEXLIST_CSCIPHER, KEXLIST_SCCIPHER,
6285 KEXLIST_CSMAC, KEXLIST_SCMAC, KEXLIST_CSCOMP, KEXLIST_SCCOMP,
6288 const char * kexlist_descr[NKEXLIST] = {
6289 "key exchange algorithm", "host key algorithm",
6290 "client-to-server cipher", "server-to-client cipher",
6291 "client-to-server MAC", "server-to-client MAC",
6292 "client-to-server compression method",
6293 "server-to-client compression method" };
6294 struct do_ssh2_transport_state {
6296 int nbits, pbits, warn_kex, warn_hk, warn_cscipher, warn_sccipher;
6297 Bignum p, g, e, f, K;
6300 int kex_init_value, kex_reply_value;
6301 const struct ssh_mac *const *maclist;
6303 const struct ssh2_cipher *cscipher_tobe;
6304 const struct ssh2_cipher *sccipher_tobe;
6305 const struct ssh_mac *csmac_tobe;
6306 const struct ssh_mac *scmac_tobe;
6307 int csmac_etm_tobe, scmac_etm_tobe;
6308 const struct ssh_compress *cscomp_tobe;
6309 const struct ssh_compress *sccomp_tobe;
6310 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
6311 int hostkeylen, siglen, rsakeylen;
6312 void *hkey; /* actual host key */
6313 void *rsakey; /* for RSA kex */
6314 void *eckey; /* for ECDH kex */
6315 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
6316 int n_preferred_kex;
6317 const struct ssh_kexes *preferred_kex[KEX_MAX];
6319 int preferred_hk[HK_MAX];
6320 int n_preferred_ciphers;
6321 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
6322 const struct ssh_compress *preferred_comp;
6323 int userauth_succeeded; /* for delayed compression */
6324 int pending_compression;
6325 int got_session_id, activated_authconn;
6326 struct Packet *pktout;
6330 struct kexinit_algorithm kexlists[NKEXLIST][MAXKEXLIST];
6332 crState(do_ssh2_transport_state);
6334 assert(!ssh->bare_connection);
6338 s->cscipher_tobe = s->sccipher_tobe = NULL;
6339 s->csmac_tobe = s->scmac_tobe = NULL;
6340 s->cscomp_tobe = s->sccomp_tobe = NULL;
6342 s->got_session_id = s->activated_authconn = FALSE;
6343 s->userauth_succeeded = FALSE;
6344 s->pending_compression = FALSE;
6347 * Be prepared to work around the buggy MAC problem.
6349 if (ssh->remote_bugs & BUG_SSH2_HMAC)
6350 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
6352 s->maclist = macs, s->nmacs = lenof(macs);
6355 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
6358 struct kexinit_algorithm *alg;
6361 * Set up the preferred key exchange. (NULL => warn below here)
6363 s->n_preferred_kex = 0;
6364 for (i = 0; i < KEX_MAX; i++) {
6365 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
6367 s->preferred_kex[s->n_preferred_kex++] =
6368 &ssh_diffiehellman_gex;
6371 s->preferred_kex[s->n_preferred_kex++] =
6372 &ssh_diffiehellman_group14;
6375 s->preferred_kex[s->n_preferred_kex++] =
6376 &ssh_diffiehellman_group1;
6379 s->preferred_kex[s->n_preferred_kex++] =
6383 s->preferred_kex[s->n_preferred_kex++] =
6387 /* Flag for later. Don't bother if it's the last in
6389 if (i < KEX_MAX - 1) {
6390 s->preferred_kex[s->n_preferred_kex++] = NULL;
6397 * Set up the preferred host key types. These are just the ids
6398 * in the enum in putty.h, so 'warn below here' is indicated
6401 s->n_preferred_hk = 0;
6402 for (i = 0; i < HK_MAX; i++) {
6403 int id = conf_get_int_int(ssh->conf, CONF_ssh_hklist, i);
6404 /* As above, don't bother with HK_WARN if it's last in the
6406 if (id != HK_WARN || i < HK_MAX - 1)
6407 s->preferred_hk[s->n_preferred_hk++] = id;
6411 * Set up the preferred ciphers. (NULL => warn below here)
6413 s->n_preferred_ciphers = 0;
6414 for (i = 0; i < CIPHER_MAX; i++) {
6415 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
6416 case CIPHER_BLOWFISH:
6417 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
6420 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
6421 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
6425 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
6428 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
6430 case CIPHER_ARCFOUR:
6431 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
6433 case CIPHER_CHACHA20:
6434 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_ccp;
6437 /* Flag for later. Don't bother if it's the last in
6439 if (i < CIPHER_MAX - 1) {
6440 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
6447 * Set up preferred compression.
6449 if (conf_get_int(ssh->conf, CONF_compression))
6450 s->preferred_comp = &ssh_zlib;
6452 s->preferred_comp = &ssh_comp_none;
6455 * Enable queueing of outgoing auth- or connection-layer
6456 * packets while we are in the middle of a key exchange.
6458 ssh->queueing = TRUE;
6461 * Flag that KEX is in progress.
6463 ssh->kex_in_progress = TRUE;
6465 for (i = 0; i < NKEXLIST; i++)
6466 for (j = 0; j < MAXKEXLIST; j++)
6467 s->kexlists[i][j].name = NULL;
6468 /* List key exchange algorithms. */
6470 for (i = 0; i < s->n_preferred_kex; i++) {
6471 const struct ssh_kexes *k = s->preferred_kex[i];
6472 if (!k) warn = TRUE;
6473 else for (j = 0; j < k->nkexes; j++) {
6474 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_KEX],
6476 alg->u.kex.kex = k->list[j];
6477 alg->u.kex.warn = warn;
6480 /* List server host key algorithms. */
6481 if (!s->got_session_id) {
6483 * In the first key exchange, we list all the algorithms
6484 * we're prepared to cope with, but prefer those algorithms
6485 * for which we have a host key for this host.
6487 * If the host key algorithm is below the warning
6488 * threshold, we warn even if we did already have a key
6489 * for it, on the basis that if the user has just
6490 * reconfigured that host key type to be warned about,
6491 * they surely _do_ want to be alerted that a server
6492 * they're actually connecting to is using it.
6495 for (i = 0; i < s->n_preferred_hk; i++) {
6496 if (s->preferred_hk[i] == HK_WARN)
6498 for (j = 0; j < lenof(hostkey_algs); j++) {
6499 if (hostkey_algs[j].id != s->preferred_hk[i])
6501 if (have_ssh_host_key(ssh->savedhost, ssh->savedport,
6502 hostkey_algs[j].alg->keytype)) {
6503 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY],
6504 hostkey_algs[j].alg->name);
6505 alg->u.hk.hostkey = hostkey_algs[j].alg;
6506 alg->u.hk.warn = warn;
6511 for (i = 0; i < s->n_preferred_hk; i++) {
6512 if (s->preferred_hk[i] == HK_WARN)
6514 for (j = 0; j < lenof(hostkey_algs); j++) {
6515 if (hostkey_algs[j].id != s->preferred_hk[i])
6517 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY],
6518 hostkey_algs[j].alg->name);
6519 alg->u.hk.hostkey = hostkey_algs[j].alg;
6520 alg->u.hk.warn = warn;
6525 * In subsequent key exchanges, we list only the kex
6526 * algorithm that was selected in the first key exchange,
6527 * so that we keep getting the same host key and hence
6528 * don't have to interrupt the user's session to ask for
6532 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY],
6533 ssh->hostkey->name);
6534 alg->u.hk.hostkey = ssh->hostkey;
6535 alg->u.hk.warn = FALSE;
6537 /* List encryption algorithms (client->server then server->client). */
6538 for (k = KEXLIST_CSCIPHER; k <= KEXLIST_SCCIPHER; k++) {
6541 alg = ssh2_kexinit_addalg(s->kexlists[k], "none");
6542 alg->u.cipher.cipher = NULL;
6543 alg->u.cipher.warn = warn;
6544 #endif /* FUZZING */
6545 for (i = 0; i < s->n_preferred_ciphers; i++) {
6546 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6547 if (!c) warn = TRUE;
6548 else for (j = 0; j < c->nciphers; j++) {
6549 alg = ssh2_kexinit_addalg(s->kexlists[k],
6551 alg->u.cipher.cipher = c->list[j];
6552 alg->u.cipher.warn = warn;
6556 /* List MAC algorithms (client->server then server->client). */
6557 for (j = KEXLIST_CSMAC; j <= KEXLIST_SCMAC; j++) {
6559 alg = ssh2_kexinit_addalg(s->kexlists[j], "none");
6560 alg->u.mac.mac = NULL;
6561 alg->u.mac.etm = FALSE;
6562 #endif /* FUZZING */
6563 for (i = 0; i < s->nmacs; i++) {
6564 alg = ssh2_kexinit_addalg(s->kexlists[j], s->maclist[i]->name);
6565 alg->u.mac.mac = s->maclist[i];
6566 alg->u.mac.etm = FALSE;
6568 for (i = 0; i < s->nmacs; i++)
6569 /* For each MAC, there may also be an ETM version,
6570 * which we list second. */
6571 if (s->maclist[i]->etm_name) {
6572 alg = ssh2_kexinit_addalg(s->kexlists[j],
6573 s->maclist[i]->etm_name);
6574 alg->u.mac.mac = s->maclist[i];
6575 alg->u.mac.etm = TRUE;
6578 /* List client->server compression algorithms,
6579 * then server->client compression algorithms. (We use the
6580 * same set twice.) */
6581 for (j = KEXLIST_CSCOMP; j <= KEXLIST_SCCOMP; j++) {
6582 assert(lenof(compressions) > 1);
6583 /* Prefer non-delayed versions */
6584 alg = ssh2_kexinit_addalg(s->kexlists[j], s->preferred_comp->name);
6585 alg->u.comp = s->preferred_comp;
6586 /* We don't even list delayed versions of algorithms until
6587 * they're allowed to be used, to avoid a race. See the end of
6589 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
6590 alg = ssh2_kexinit_addalg(s->kexlists[j],
6591 s->preferred_comp->delayed_name);
6592 alg->u.comp = s->preferred_comp;
6594 for (i = 0; i < lenof(compressions); i++) {
6595 const struct ssh_compress *c = compressions[i];
6596 alg = ssh2_kexinit_addalg(s->kexlists[j], c->name);
6598 if (s->userauth_succeeded && c->delayed_name) {
6599 alg = ssh2_kexinit_addalg(s->kexlists[j], c->delayed_name);
6605 * Construct and send our key exchange packet.
6607 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
6608 for (i = 0; i < 16; i++)
6609 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
6610 for (i = 0; i < NKEXLIST; i++) {
6611 ssh2_pkt_addstring_start(s->pktout);
6612 for (j = 0; j < MAXKEXLIST; j++) {
6613 if (s->kexlists[i][j].name == NULL) break;
6614 ssh2_pkt_addstring_commasep(s->pktout, s->kexlists[i][j].name);
6617 /* List client->server languages. Empty list. */
6618 ssh2_pkt_addstring_start(s->pktout);
6619 /* List server->client languages. Empty list. */
6620 ssh2_pkt_addstring_start(s->pktout);
6621 /* First KEX packet does _not_ follow, because we're not that brave. */
6622 ssh2_pkt_addbool(s->pktout, FALSE);
6624 ssh2_pkt_adduint32(s->pktout, 0);
6627 s->our_kexinitlen = s->pktout->length - 5;
6628 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
6629 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
6631 ssh2_pkt_send_noqueue(ssh, s->pktout);
6634 crWaitUntilV(pktin);
6637 * Now examine the other side's KEXINIT to see what we're up
6644 if (pktin->type != SSH2_MSG_KEXINIT) {
6645 bombout(("expected key exchange packet from server"));
6649 ssh->hostkey = NULL;
6650 s->cscipher_tobe = NULL;
6651 s->sccipher_tobe = NULL;
6652 s->csmac_tobe = NULL;
6653 s->scmac_tobe = NULL;
6654 s->cscomp_tobe = NULL;
6655 s->sccomp_tobe = NULL;
6656 s->warn_kex = s->warn_hk = FALSE;
6657 s->warn_cscipher = s->warn_sccipher = FALSE;
6659 pktin->savedpos += 16; /* skip garbage cookie */
6662 for (i = 0; i < NKEXLIST; i++) {
6663 ssh_pkt_getstring(pktin, &str, &len);
6665 bombout(("KEXINIT packet was incomplete"));
6669 /* If we've already selected a cipher which requires a
6670 * particular MAC, then just select that, and don't even
6671 * bother looking through the server's KEXINIT string for
6673 if (i == KEXLIST_CSMAC && s->cscipher_tobe &&
6674 s->cscipher_tobe->required_mac) {
6675 s->csmac_tobe = s->cscipher_tobe->required_mac;
6676 s->csmac_etm_tobe = !!(s->csmac_tobe->etm_name);
6679 if (i == KEXLIST_SCMAC && s->sccipher_tobe &&
6680 s->sccipher_tobe->required_mac) {
6681 s->scmac_tobe = s->sccipher_tobe->required_mac;
6682 s->scmac_etm_tobe = !!(s->scmac_tobe->etm_name);
6686 for (j = 0; j < MAXKEXLIST; j++) {
6687 struct kexinit_algorithm *alg = &s->kexlists[i][j];
6688 if (alg->name == NULL) break;
6689 if (in_commasep_string(alg->name, str, len)) {
6690 /* We've found a matching algorithm. */
6691 if (i == KEXLIST_KEX || i == KEXLIST_HOSTKEY) {
6692 /* Check if we might need to ignore first kex pkt */
6694 !first_in_commasep_string(alg->name, str, len))
6697 if (i == KEXLIST_KEX) {
6698 ssh->kex = alg->u.kex.kex;
6699 s->warn_kex = alg->u.kex.warn;
6700 } else if (i == KEXLIST_HOSTKEY) {
6701 ssh->hostkey = alg->u.hk.hostkey;
6702 s->warn_hk = alg->u.hk.warn;
6703 } else if (i == KEXLIST_CSCIPHER) {
6704 s->cscipher_tobe = alg->u.cipher.cipher;
6705 s->warn_cscipher = alg->u.cipher.warn;
6706 } else if (i == KEXLIST_SCCIPHER) {
6707 s->sccipher_tobe = alg->u.cipher.cipher;
6708 s->warn_sccipher = alg->u.cipher.warn;
6709 } else if (i == KEXLIST_CSMAC) {
6710 s->csmac_tobe = alg->u.mac.mac;
6711 s->csmac_etm_tobe = alg->u.mac.etm;
6712 } else if (i == KEXLIST_SCMAC) {
6713 s->scmac_tobe = alg->u.mac.mac;
6714 s->scmac_etm_tobe = alg->u.mac.etm;
6715 } else if (i == KEXLIST_CSCOMP) {
6716 s->cscomp_tobe = alg->u.comp;
6717 } else if (i == KEXLIST_SCCOMP) {
6718 s->sccomp_tobe = alg->u.comp;
6722 if ((i == KEXLIST_CSCOMP || i == KEXLIST_SCCOMP) &&
6723 in_commasep_string(alg->u.comp->delayed_name, str, len))
6724 s->pending_compression = TRUE; /* try this later */
6726 bombout(("Couldn't agree a %s (available: %.*s)",
6727 kexlist_descr[i], len, str));
6731 if (i == KEXLIST_HOSTKEY) {
6735 * In addition to deciding which host key we're
6736 * actually going to use, we should make a list of the
6737 * host keys offered by the server which we _don't_
6738 * have cached. These will be offered as cross-
6739 * certification options by ssh_get_specials.
6741 * We also count the key we're currently using for KEX
6742 * as one we've already got, because by the time this
6743 * menu becomes visible, it will be.
6745 ssh->n_uncert_hostkeys = 0;
6747 for (j = 0; j < lenof(hostkey_algs); j++) {
6748 if (hostkey_algs[j].alg != ssh->hostkey &&
6749 in_commasep_string(hostkey_algs[j].alg->name,
6751 !have_ssh_host_key(ssh->savedhost, ssh->savedport,
6752 hostkey_algs[j].alg->keytype)) {
6753 ssh->uncert_hostkeys[ssh->n_uncert_hostkeys++] = j;
6759 if (s->pending_compression) {
6760 logevent("Server supports delayed compression; "
6761 "will try this later");
6763 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
6764 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
6765 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
6767 ssh->exhash = ssh->kex->hash->init();
6768 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
6769 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
6770 hash_string(ssh->kex->hash, ssh->exhash,
6771 s->our_kexinit, s->our_kexinitlen);
6772 sfree(s->our_kexinit);
6773 /* Include the type byte in the hash of server's KEXINIT */
6774 hash_string(ssh->kex->hash, ssh->exhash,
6775 pktin->body - 1, pktin->length + 1);
6778 ssh_set_frozen(ssh, 1);
6779 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
6781 ssh_dialog_callback, ssh);
6782 if (s->dlgret < 0) {
6786 bombout(("Unexpected data from server while"
6787 " waiting for user response"));
6790 } while (pktin || inlen > 0);
6791 s->dlgret = ssh->user_response;
6793 ssh_set_frozen(ssh, 0);
6794 if (s->dlgret == 0) {
6795 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
6805 ssh_set_frozen(ssh, 1);
6808 * Change warning box wording depending on why we chose a
6809 * warning-level host key algorithm. If it's because
6810 * that's all we have *cached*, use the askhk mechanism,
6811 * and list the host keys we could usefully cross-certify.
6812 * Otherwise, use askalg for the standard wording.
6815 for (j = 0; j < ssh->n_uncert_hostkeys; j++) {
6816 const struct ssh_signkey_with_user_pref_id *hktype =
6817 &hostkey_algs[ssh->uncert_hostkeys[j]];
6819 for (k = 0; k < HK_MAX; k++) {
6820 int id = conf_get_int_int(ssh->conf, CONF_ssh_hklist, k);
6821 if (id == HK_WARN) {
6823 } else if (id == hktype->id) {
6830 char *old_ba = betteralgs;
6831 betteralgs = dupcat(betteralgs, ",",
6833 (const char *)NULL);
6836 betteralgs = dupstr(hktype->alg->name);
6841 s->dlgret = askhk(ssh->frontend, ssh->hostkey->name,
6842 betteralgs, ssh_dialog_callback, ssh);
6845 s->dlgret = askalg(ssh->frontend, "host key type",
6847 ssh_dialog_callback, ssh);
6849 if (s->dlgret < 0) {
6853 bombout(("Unexpected data from server while"
6854 " waiting for user response"));
6857 } while (pktin || inlen > 0);
6858 s->dlgret = ssh->user_response;
6860 ssh_set_frozen(ssh, 0);
6861 if (s->dlgret == 0) {
6862 ssh_disconnect(ssh, "User aborted at host key warning", NULL,
6868 if (s->warn_cscipher) {
6869 ssh_set_frozen(ssh, 1);
6870 s->dlgret = askalg(ssh->frontend,
6871 "client-to-server cipher",
6872 s->cscipher_tobe->name,
6873 ssh_dialog_callback, ssh);
6874 if (s->dlgret < 0) {
6878 bombout(("Unexpected data from server while"
6879 " waiting for user response"));
6882 } while (pktin || inlen > 0);
6883 s->dlgret = ssh->user_response;
6885 ssh_set_frozen(ssh, 0);
6886 if (s->dlgret == 0) {
6887 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6893 if (s->warn_sccipher) {
6894 ssh_set_frozen(ssh, 1);
6895 s->dlgret = askalg(ssh->frontend,
6896 "server-to-client cipher",
6897 s->sccipher_tobe->name,
6898 ssh_dialog_callback, ssh);
6899 if (s->dlgret < 0) {
6903 bombout(("Unexpected data from server while"
6904 " waiting for user response"));
6907 } while (pktin || inlen > 0);
6908 s->dlgret = ssh->user_response;
6910 ssh_set_frozen(ssh, 0);
6911 if (s->dlgret == 0) {
6912 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6918 if (s->ignorepkt) /* first_kex_packet_follows */
6919 crWaitUntilV(pktin); /* Ignore packet */
6922 if (ssh->kex->main_type == KEXTYPE_DH) {
6924 * Work out the number of bits of key we will need from the
6925 * key exchange. We start with the maximum key length of
6931 csbits = s->cscipher_tobe ? s->cscipher_tobe->real_keybits : 0;
6932 scbits = s->sccipher_tobe ? s->sccipher_tobe->real_keybits : 0;
6933 s->nbits = (csbits > scbits ? csbits : scbits);
6935 /* The keys only have hlen-bit entropy, since they're based on
6936 * a hash. So cap the key size at hlen bits. */
6937 if (s->nbits > ssh->kex->hash->hlen * 8)
6938 s->nbits = ssh->kex->hash->hlen * 8;
6941 * If we're doing Diffie-Hellman group exchange, start by
6942 * requesting a group.
6944 if (dh_is_gex(ssh->kex)) {
6945 logevent("Doing Diffie-Hellman group exchange");
6946 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
6948 * Work out how big a DH group we will need to allow that
6951 s->pbits = 512 << ((s->nbits - 1) / 64);
6952 if (s->pbits < DH_MIN_SIZE)
6953 s->pbits = DH_MIN_SIZE;
6954 if (s->pbits > DH_MAX_SIZE)
6955 s->pbits = DH_MAX_SIZE;
6956 if ((ssh->remote_bugs & BUG_SSH2_OLDGEX)) {
6957 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST_OLD);
6958 ssh2_pkt_adduint32(s->pktout, s->pbits);
6960 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6961 ssh2_pkt_adduint32(s->pktout, DH_MIN_SIZE);
6962 ssh2_pkt_adduint32(s->pktout, s->pbits);
6963 ssh2_pkt_adduint32(s->pktout, DH_MAX_SIZE);
6965 ssh2_pkt_send_noqueue(ssh, s->pktout);
6967 crWaitUntilV(pktin);
6968 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6969 bombout(("expected key exchange group packet from server"));
6972 s->p = ssh2_pkt_getmp(pktin);
6973 s->g = ssh2_pkt_getmp(pktin);
6974 if (!s->p || !s->g) {
6975 bombout(("unable to read mp-ints from incoming group packet"));
6978 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6979 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6980 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6982 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
6983 ssh->kex_ctx = dh_setup_group(ssh->kex);
6984 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6985 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6986 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6987 ssh->kex->groupname);
6990 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6991 ssh->kex->hash->text_name);
6993 * Now generate and send e for Diffie-Hellman.
6995 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6996 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6997 s->pktout = ssh2_pkt_init(s->kex_init_value);
6998 ssh2_pkt_addmp(s->pktout, s->e);
6999 ssh2_pkt_send_noqueue(ssh, s->pktout);
7001 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
7002 crWaitUntilV(pktin);
7003 if (pktin->type != s->kex_reply_value) {
7004 bombout(("expected key exchange reply packet from server"));
7007 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
7008 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
7009 if (!s->hostkeydata) {
7010 bombout(("unable to parse key exchange reply packet"));
7013 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
7014 s->hostkeydata, s->hostkeylen);
7015 s->f = ssh2_pkt_getmp(pktin);
7017 bombout(("unable to parse key exchange reply packet"));
7020 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
7022 bombout(("unable to parse key exchange reply packet"));
7027 const char *err = dh_validate_f(ssh->kex_ctx, s->f);
7029 bombout(("key exchange reply failed validation: %s", err));
7033 s->K = dh_find_K(ssh->kex_ctx, s->f);
7035 /* We assume everything from now on will be quick, and it might
7036 * involve user interaction. */
7037 set_busy_status(ssh->frontend, BUSY_NOT);
7039 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
7040 if (dh_is_gex(ssh->kex)) {
7041 if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX))
7042 hash_uint32(ssh->kex->hash, ssh->exhash, DH_MIN_SIZE);
7043 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
7044 if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX))
7045 hash_uint32(ssh->kex->hash, ssh->exhash, DH_MAX_SIZE);
7046 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
7047 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
7049 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
7050 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
7052 dh_cleanup(ssh->kex_ctx);
7054 if (dh_is_gex(ssh->kex)) {
7058 } else if (ssh->kex->main_type == KEXTYPE_ECDH) {
7060 logeventf(ssh, "Doing ECDH key exchange with curve %s and hash %s",
7061 ssh_ecdhkex_curve_textname(ssh->kex),
7062 ssh->kex->hash->text_name);
7063 ssh->pkt_kctx = SSH2_PKTCTX_ECDHKEX;
7065 s->eckey = ssh_ecdhkex_newkey(ssh->kex);
7067 bombout(("Unable to generate key for ECDH"));
7073 int publicPointLength;
7074 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
7076 ssh_ecdhkex_freekey(s->eckey);
7077 bombout(("Unable to encode public key for ECDH"));
7080 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_ECDH_INIT);
7081 ssh2_pkt_addstring_start(s->pktout);
7082 ssh2_pkt_addstring_data(s->pktout, publicPoint, publicPointLength);
7086 ssh2_pkt_send_noqueue(ssh, s->pktout);
7088 crWaitUntilV(pktin);
7089 if (pktin->type != SSH2_MSG_KEX_ECDH_REPLY) {
7090 ssh_ecdhkex_freekey(s->eckey);
7091 bombout(("expected ECDH reply packet from server"));
7095 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
7096 if (!s->hostkeydata) {
7097 bombout(("unable to parse ECDH reply packet"));
7100 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
7101 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
7102 s->hostkeydata, s->hostkeylen);
7106 int publicPointLength;
7107 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
7109 ssh_ecdhkex_freekey(s->eckey);
7110 bombout(("Unable to encode public key for ECDH hash"));
7113 hash_string(ssh->kex->hash, ssh->exhash,
7114 publicPoint, publicPointLength);
7121 ssh_pkt_getstring(pktin, &keydata, &keylen);
7123 bombout(("unable to parse ECDH reply packet"));
7126 hash_string(ssh->kex->hash, ssh->exhash, keydata, keylen);
7127 s->K = ssh_ecdhkex_getkey(s->eckey, keydata, keylen);
7129 ssh_ecdhkex_freekey(s->eckey);
7130 bombout(("point received in ECDH was not valid"));
7135 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
7137 bombout(("unable to parse key exchange reply packet"));
7141 ssh_ecdhkex_freekey(s->eckey);
7143 logeventf(ssh, "Doing RSA key exchange with hash %s",
7144 ssh->kex->hash->text_name);
7145 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
7147 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
7150 crWaitUntilV(pktin);
7151 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
7152 bombout(("expected RSA public key packet from server"));
7156 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
7157 if (!s->hostkeydata) {
7158 bombout(("unable to parse RSA public key packet"));
7161 hash_string(ssh->kex->hash, ssh->exhash,
7162 s->hostkeydata, s->hostkeylen);
7163 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
7164 s->hostkeydata, s->hostkeylen);
7168 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
7170 bombout(("unable to parse RSA public key packet"));
7173 s->rsakeydata = snewn(s->rsakeylen, char);
7174 memcpy(s->rsakeydata, keydata, s->rsakeylen);
7177 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
7179 sfree(s->rsakeydata);
7180 bombout(("unable to parse RSA public key from server"));
7184 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
7187 * Next, set up a shared secret K, of precisely KLEN -
7188 * 2*HLEN - 49 bits, where KLEN is the bit length of the
7189 * RSA key modulus and HLEN is the bit length of the hash
7193 int klen = ssh_rsakex_klen(s->rsakey);
7194 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
7196 unsigned char *kstr1, *kstr2, *outstr;
7197 int kstr1len, kstr2len, outstrlen;
7199 s->K = bn_power_2(nbits - 1);
7201 for (i = 0; i < nbits; i++) {
7203 byte = random_byte();
7205 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
7209 * Encode this as an mpint.
7211 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
7212 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
7213 PUT_32BIT(kstr2, kstr1len);
7214 memcpy(kstr2 + 4, kstr1, kstr1len);
7217 * Encrypt it with the given RSA key.
7219 outstrlen = (klen + 7) / 8;
7220 outstr = snewn(outstrlen, unsigned char);
7221 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
7222 outstr, outstrlen, s->rsakey);
7225 * And send it off in a return packet.
7227 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
7228 ssh2_pkt_addstring_start(s->pktout);
7229 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
7230 ssh2_pkt_send_noqueue(ssh, s->pktout);
7232 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
7239 ssh_rsakex_freekey(s->rsakey);
7241 crWaitUntilV(pktin);
7242 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
7243 sfree(s->rsakeydata);
7244 bombout(("expected signature packet from server"));
7248 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
7250 bombout(("unable to parse signature packet"));
7254 sfree(s->rsakeydata);
7257 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
7258 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
7259 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
7261 ssh->kex_ctx = NULL;
7264 debug(("Exchange hash is:\n"));
7265 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
7269 bombout(("Server's host key is invalid"));
7273 if (!ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
7274 (char *)s->exchange_hash,
7275 ssh->kex->hash->hlen)) {
7277 bombout(("Server's host key did not match the signature supplied"));
7282 s->keystr = ssh->hostkey->fmtkey(s->hkey);
7283 if (!s->got_session_id) {
7285 * Make a note of any other host key formats that are available.
7288 int i, j, nkeys = 0;
7290 for (i = 0; i < lenof(hostkey_algs); i++) {
7291 if (hostkey_algs[i].alg == ssh->hostkey)
7294 for (j = 0; j < ssh->n_uncert_hostkeys; j++)
7295 if (ssh->uncert_hostkeys[j] == i)
7298 if (j < ssh->n_uncert_hostkeys) {
7301 newlist = dupprintf("%s/%s", list,
7302 hostkey_algs[i].alg->name);
7304 newlist = dupprintf("%s", hostkey_algs[i].alg->name);
7312 "Server also has %s host key%s, but we "
7313 "don't know %s", list,
7314 nkeys > 1 ? "s" : "",
7315 nkeys > 1 ? "any of them" : "it");
7321 * Authenticate remote host: verify host key. (We've already
7322 * checked the signature of the exchange hash.)
7324 s->fingerprint = ssh2_fingerprint(ssh->hostkey, s->hkey);
7325 logevent("Host key fingerprint is:");
7326 logevent(s->fingerprint);
7327 /* First check against manually configured host keys. */
7328 s->dlgret = verify_ssh_manual_host_key(ssh, s->fingerprint,
7329 ssh->hostkey, s->hkey);
7330 if (s->dlgret == 0) { /* did not match */
7331 bombout(("Host key did not appear in manually configured list"));
7333 } else if (s->dlgret < 0) { /* none configured; use standard handling */
7334 ssh_set_frozen(ssh, 1);
7335 s->dlgret = verify_ssh_host_key(ssh->frontend,
7336 ssh->savedhost, ssh->savedport,
7337 ssh->hostkey->keytype, s->keystr,
7339 ssh_dialog_callback, ssh);
7343 if (s->dlgret < 0) {
7347 bombout(("Unexpected data from server while waiting"
7348 " for user host key response"));
7351 } while (pktin || inlen > 0);
7352 s->dlgret = ssh->user_response;
7354 ssh_set_frozen(ssh, 0);
7355 if (s->dlgret == 0) {
7356 ssh_disconnect(ssh, "Aborted at host key verification", NULL,
7361 sfree(s->fingerprint);
7363 * Save this host key, to check against the one presented in
7364 * subsequent rekeys.
7366 ssh->hostkey_str = s->keystr;
7367 } else if (ssh->cross_certifying) {
7368 s->fingerprint = ssh2_fingerprint(ssh->hostkey, s->hkey);
7369 logevent("Storing additional host key for this host:");
7370 logevent(s->fingerprint);
7371 store_host_key(ssh->savedhost, ssh->savedport,
7372 ssh->hostkey->keytype, s->keystr);
7373 ssh->cross_certifying = FALSE;
7375 * Don't forget to store the new key as the one we'll be
7376 * re-checking in future normal rekeys.
7378 ssh->hostkey_str = s->keystr;
7381 * In a rekey, we never present an interactive host key
7382 * verification request to the user. Instead, we simply
7383 * enforce that the key we're seeing this time is identical to
7384 * the one we saw before.
7386 if (strcmp(ssh->hostkey_str, s->keystr)) {
7388 bombout(("Host key was different in repeat key exchange"));
7394 ssh->hostkey->freekey(s->hkey);
7397 * The exchange hash from the very first key exchange is also
7398 * the session id, used in session key construction and
7401 if (!s->got_session_id) {
7402 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
7403 memcpy(ssh->v2_session_id, s->exchange_hash,
7404 sizeof(s->exchange_hash));
7405 ssh->v2_session_id_len = ssh->kex->hash->hlen;
7406 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
7407 s->got_session_id = TRUE;
7411 * Send SSH2_MSG_NEWKEYS.
7413 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
7414 ssh2_pkt_send_noqueue(ssh, s->pktout);
7415 ssh->outgoing_data_size = 0; /* start counting from here */
7418 * We've sent client NEWKEYS, so create and initialise
7419 * client-to-server session keys.
7421 if (ssh->cs_cipher_ctx)
7422 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7423 ssh->cscipher = s->cscipher_tobe;
7424 if (ssh->cscipher) ssh->cs_cipher_ctx = ssh->cscipher->make_context();
7426 if (ssh->cs_mac_ctx)
7427 ssh->csmac->free_context(ssh->cs_mac_ctx);
7428 ssh->csmac = s->csmac_tobe;
7429 ssh->csmac_etm = s->csmac_etm_tobe;
7431 ssh->cs_mac_ctx = ssh->csmac->make_context(ssh->cs_cipher_ctx);
7433 if (ssh->cs_comp_ctx)
7434 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7435 ssh->cscomp = s->cscomp_tobe;
7436 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
7439 * Set IVs on client-to-server keys. Here we use the exchange
7440 * hash from the _first_ key exchange.
7442 if (ssh->cscipher) {
7445 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'C',
7446 ssh->cscipher->padded_keybytes);
7447 ssh->cscipher->setkey(ssh->cs_cipher_ctx, key);
7448 smemclr(key, ssh->cscipher->padded_keybytes);
7451 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'A',
7452 ssh->cscipher->blksize);
7453 ssh->cscipher->setiv(ssh->cs_cipher_ctx, key);
7454 smemclr(key, ssh->cscipher->blksize);
7460 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'E',
7461 ssh->csmac->keylen);
7462 ssh->csmac->setkey(ssh->cs_mac_ctx, key);
7463 smemclr(key, ssh->csmac->keylen);
7468 logeventf(ssh, "Initialised %.200s client->server encryption",
7469 ssh->cscipher->text_name);
7471 logeventf(ssh, "Initialised %.200s client->server MAC algorithm%s%s",
7472 ssh->csmac->text_name,
7473 ssh->csmac_etm ? " (in ETM mode)" : "",
7474 ssh->cscipher->required_mac ? " (required by cipher)" : "");
7475 if (ssh->cscomp->text_name)
7476 logeventf(ssh, "Initialised %s compression",
7477 ssh->cscomp->text_name);
7480 * Now our end of the key exchange is complete, we can send all
7481 * our queued higher-layer packets.
7483 ssh->queueing = FALSE;
7484 ssh2_pkt_queuesend(ssh);
7487 * Expect SSH2_MSG_NEWKEYS from server.
7489 crWaitUntilV(pktin);
7490 if (pktin->type != SSH2_MSG_NEWKEYS) {
7491 bombout(("expected new-keys packet from server"));
7494 ssh->incoming_data_size = 0; /* start counting from here */
7497 * We've seen server NEWKEYS, so create and initialise
7498 * server-to-client session keys.
7500 if (ssh->sc_cipher_ctx)
7501 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7502 if (s->sccipher_tobe) {
7503 ssh->sccipher = s->sccipher_tobe;
7504 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
7507 if (ssh->sc_mac_ctx)
7508 ssh->scmac->free_context(ssh->sc_mac_ctx);
7509 if (s->scmac_tobe) {
7510 ssh->scmac = s->scmac_tobe;
7511 ssh->scmac_etm = s->scmac_etm_tobe;
7512 ssh->sc_mac_ctx = ssh->scmac->make_context(ssh->sc_cipher_ctx);
7515 if (ssh->sc_comp_ctx)
7516 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7517 ssh->sccomp = s->sccomp_tobe;
7518 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
7521 * Set IVs on server-to-client keys. Here we use the exchange
7522 * hash from the _first_ key exchange.
7524 if (ssh->sccipher) {
7527 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'D',
7528 ssh->sccipher->padded_keybytes);
7529 ssh->sccipher->setkey(ssh->sc_cipher_ctx, key);
7530 smemclr(key, ssh->sccipher->padded_keybytes);
7533 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'B',
7534 ssh->sccipher->blksize);
7535 ssh->sccipher->setiv(ssh->sc_cipher_ctx, key);
7536 smemclr(key, ssh->sccipher->blksize);
7542 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'F',
7543 ssh->scmac->keylen);
7544 ssh->scmac->setkey(ssh->sc_mac_ctx, key);
7545 smemclr(key, ssh->scmac->keylen);
7549 logeventf(ssh, "Initialised %.200s server->client encryption",
7550 ssh->sccipher->text_name);
7552 logeventf(ssh, "Initialised %.200s server->client MAC algorithm%s%s",
7553 ssh->scmac->text_name,
7554 ssh->scmac_etm ? " (in ETM mode)" : "",
7555 ssh->sccipher->required_mac ? " (required by cipher)" : "");
7556 if (ssh->sccomp->text_name)
7557 logeventf(ssh, "Initialised %s decompression",
7558 ssh->sccomp->text_name);
7561 * Free shared secret.
7566 * Update the specials menu to list the remaining uncertified host
7569 update_specials_menu(ssh->frontend);
7572 * Key exchange is over. Loop straight back round if we have a
7573 * deferred rekey reason.
7575 if (ssh->deferred_rekey_reason) {
7576 logevent(ssh->deferred_rekey_reason);
7578 ssh->deferred_rekey_reason = NULL;
7579 goto begin_key_exchange;
7583 * Otherwise, schedule a timer for our next rekey.
7585 ssh->kex_in_progress = FALSE;
7586 ssh->last_rekey = GETTICKCOUNT();
7587 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
7588 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7592 * Now we're encrypting. Begin returning 1 to the protocol main
7593 * function so that other things can run on top of the
7594 * transport. If we ever see a KEXINIT, we must go back to the
7597 * We _also_ go back to the start if we see pktin==NULL and
7598 * inlen negative, because this is a special signal meaning
7599 * `initiate client-driven rekey', and `in' contains a message
7600 * giving the reason for the rekey.
7602 * inlen==-1 means always initiate a rekey;
7603 * inlen==-2 means that userauth has completed successfully and
7604 * we should consider rekeying (for delayed compression).
7606 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
7607 (!pktin && inlen < 0))) {
7609 if (!ssh->protocol_initial_phase_done) {
7610 ssh->protocol_initial_phase_done = TRUE;
7612 * Allow authconn to initialise itself.
7614 do_ssh2_authconn(ssh, NULL, 0, NULL);
7619 logevent("Server initiated key re-exchange");
7623 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
7624 * delayed compression, if it's available.
7626 * draft-miller-secsh-compression-delayed-00 says that you
7627 * negotiate delayed compression in the first key exchange, and
7628 * both sides start compressing when the server has sent
7629 * USERAUTH_SUCCESS. This has a race condition -- the server
7630 * can't know when the client has seen it, and thus which incoming
7631 * packets it should treat as compressed.
7633 * Instead, we do the initial key exchange without offering the
7634 * delayed methods, but note if the server offers them; when we
7635 * get here, if a delayed method was available that was higher
7636 * on our list than what we got, we initiate a rekey in which we
7637 * _do_ list the delayed methods (and hopefully get it as a
7638 * result). Subsequent rekeys will do the same.
7640 assert(!s->userauth_succeeded); /* should only happen once */
7641 s->userauth_succeeded = TRUE;
7642 if (!s->pending_compression)
7643 /* Can't see any point rekeying. */
7644 goto wait_for_rekey; /* this is utterly horrid */
7645 /* else fall through to rekey... */
7646 s->pending_compression = FALSE;
7649 * Now we've decided to rekey.
7651 * Special case: if the server bug is set that doesn't
7652 * allow rekeying, we give a different log message and
7653 * continue waiting. (If such a server _initiates_ a rekey,
7654 * we process it anyway!)
7656 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
7657 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
7659 /* Reset the counters, so that at least this message doesn't
7660 * hit the event log _too_ often. */
7661 ssh->outgoing_data_size = 0;
7662 ssh->incoming_data_size = 0;
7663 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
7665 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7668 goto wait_for_rekey; /* this is still utterly horrid */
7670 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
7673 goto begin_key_exchange;
7679 * Send data on an SSH channel. In SSH-2, this involves buffering it
7682 static int ssh_send_channel_data(struct ssh_channel *c, const char *buf,
7685 if (c->ssh->version == 2) {
7686 bufchain_add(&c->v.v2.outbuffer, buf, len);
7687 return ssh2_try_send(c);
7689 send_packet(c->ssh, SSH1_MSG_CHANNEL_DATA,
7690 PKT_INT, c->remoteid,
7695 * In SSH-1 we can return 0 here - implying that channels are
7696 * never individually throttled - because the only
7697 * circumstance that can cause throttling will be the whole
7698 * SSH connection backing up, in which case _everything_ will
7699 * be throttled as a whole.
7706 * Attempt to send data on an SSH-2 channel.
7708 static int ssh2_try_send(struct ssh_channel *c)
7711 struct Packet *pktout;
7714 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
7717 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
7718 if ((unsigned)len > c->v.v2.remwindow)
7719 len = c->v.v2.remwindow;
7720 if ((unsigned)len > c->v.v2.remmaxpkt)
7721 len = c->v.v2.remmaxpkt;
7722 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
7723 ssh2_pkt_adduint32(pktout, c->remoteid);
7724 ssh2_pkt_addstring_start(pktout);
7725 ssh2_pkt_addstring_data(pktout, data, len);
7726 ssh2_pkt_send(ssh, pktout);
7727 bufchain_consume(&c->v.v2.outbuffer, len);
7728 c->v.v2.remwindow -= len;
7732 * After having sent as much data as we can, return the amount
7735 ret = bufchain_size(&c->v.v2.outbuffer);
7738 * And if there's no data pending but we need to send an EOF, send
7741 if (!ret && c->pending_eof)
7742 ssh_channel_try_eof(c);
7747 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
7750 if (c->closes & CLOSES_SENT_EOF)
7751 return; /* don't send on channels we've EOFed */
7752 bufsize = ssh2_try_send(c);
7755 case CHAN_MAINSESSION:
7756 /* stdin need not receive an unthrottle
7757 * notification since it will be polled */
7760 x11_unthrottle(c->u.x11.xconn);
7763 /* agent sockets are request/response and need no
7764 * buffer management */
7767 pfd_unthrottle(c->u.pfd.pf);
7773 static int ssh_is_simple(Ssh ssh)
7776 * We use the 'simple' variant of the SSH protocol if we're asked
7777 * to, except not if we're also doing connection-sharing (either
7778 * tunnelling our packets over an upstream or expecting to be
7779 * tunnelled over ourselves), since then the assumption that we
7780 * have only one channel to worry about is not true after all.
7782 return (conf_get_int(ssh->conf, CONF_ssh_simple) &&
7783 !ssh->bare_connection && !ssh->connshare);
7787 * Set up most of a new ssh_channel for SSH-2.
7789 static void ssh2_channel_init(struct ssh_channel *c)
7792 c->localid = alloc_channel_id(ssh);
7794 c->pending_eof = FALSE;
7795 c->throttling_conn = FALSE;
7796 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
7797 ssh_is_simple(ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
7798 c->v.v2.chanreq_head = NULL;
7799 c->v.v2.throttle_state = UNTHROTTLED;
7800 bufchain_init(&c->v.v2.outbuffer);
7804 * Construct the common parts of a CHANNEL_OPEN.
7806 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c,
7809 struct Packet *pktout;
7811 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7812 ssh2_pkt_addstring(pktout, type);
7813 ssh2_pkt_adduint32(pktout, c->localid);
7814 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7815 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7820 * CHANNEL_FAILURE doesn't come with any indication of what message
7821 * caused it, so we have to keep track of the outstanding
7822 * CHANNEL_REQUESTs ourselves.
7824 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
7825 cchandler_fn_t handler, void *ctx)
7827 struct outstanding_channel_request *ocr =
7828 snew(struct outstanding_channel_request);
7830 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7831 ocr->handler = handler;
7834 if (!c->v.v2.chanreq_head)
7835 c->v.v2.chanreq_head = ocr;
7837 c->v.v2.chanreq_tail->next = ocr;
7838 c->v.v2.chanreq_tail = ocr;
7842 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
7843 * NULL then a reply will be requested and the handler will be called
7844 * when it arrives. The returned packet is ready to have any
7845 * request-specific data added and be sent. Note that if a handler is
7846 * provided, it's essential that the request actually be sent.
7848 * The handler will usually be passed the response packet in pktin. If
7849 * pktin is NULL, this means that no reply will ever be forthcoming
7850 * (e.g. because the entire connection is being destroyed, or because
7851 * the server initiated channel closure before we saw the response)
7852 * and the handler should free any storage it's holding.
7854 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c,
7856 cchandler_fn_t handler, void *ctx)
7858 struct Packet *pktout;
7860 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7861 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7862 ssh2_pkt_adduint32(pktout, c->remoteid);
7863 ssh2_pkt_addstring(pktout, type);
7864 ssh2_pkt_addbool(pktout, handler != NULL);
7865 if (handler != NULL)
7866 ssh2_queue_chanreq_handler(c, handler, ctx);
7871 * Potentially enlarge the window on an SSH-2 channel.
7873 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
7875 static void ssh2_set_window(struct ssh_channel *c, int newwin)
7880 * Never send WINDOW_ADJUST for a channel that the remote side has
7881 * already sent EOF on; there's no point, since it won't be
7882 * sending any more data anyway. Ditto if _we've_ already sent
7885 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
7889 * Also, never widen the window for an X11 channel when we're
7890 * still waiting to see its initial auth and may yet hand it off
7893 if (c->type == CHAN_X11 && c->u.x11.initial)
7897 * If the remote end has a habit of ignoring maxpkt, limit the
7898 * window so that it has no choice (assuming it doesn't ignore the
7901 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
7902 newwin = OUR_V2_MAXPKT;
7905 * Only send a WINDOW_ADJUST if there's significantly more window
7906 * available than the other end thinks there is. This saves us
7907 * sending a WINDOW_ADJUST for every character in a shell session.
7909 * "Significant" is arbitrarily defined as half the window size.
7911 if (newwin / 2 >= c->v.v2.locwindow) {
7912 struct Packet *pktout;
7916 * In order to keep track of how much window the client
7917 * actually has available, we'd like it to acknowledge each
7918 * WINDOW_ADJUST. We can't do that directly, so we accompany
7919 * it with a CHANNEL_REQUEST that has to be acknowledged.
7921 * This is only necessary if we're opening the window wide.
7922 * If we're not, then throughput is being constrained by
7923 * something other than the maximum window size anyway.
7925 if (newwin == c->v.v2.locmaxwin &&
7926 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
7927 up = snew(unsigned);
7928 *up = newwin - c->v.v2.locwindow;
7929 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
7930 ssh2_handle_winadj_response, up);
7931 ssh2_pkt_send(ssh, pktout);
7933 if (c->v.v2.throttle_state != UNTHROTTLED)
7934 c->v.v2.throttle_state = UNTHROTTLING;
7936 /* Pretend the WINDOW_ADJUST was acked immediately. */
7937 c->v.v2.remlocwin = newwin;
7938 c->v.v2.throttle_state = THROTTLED;
7940 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7941 ssh2_pkt_adduint32(pktout, c->remoteid);
7942 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
7943 ssh2_pkt_send(ssh, pktout);
7944 c->v.v2.locwindow = newwin;
7949 * Find the channel associated with a message. If there's no channel,
7950 * or it's not properly open, make a noise about it and return NULL.
7952 static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
7954 unsigned localid = ssh_pkt_getuint32(pktin);
7955 struct ssh_channel *c;
7957 c = find234(ssh->channels, &localid, ssh_channelfind);
7959 (c->type != CHAN_SHARING && c->halfopen &&
7960 pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
7961 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
7962 char *buf = dupprintf("Received %s for %s channel %u",
7963 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
7965 c ? "half-open" : "nonexistent", localid);
7966 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
7973 static void ssh2_handle_winadj_response(struct ssh_channel *c,
7974 struct Packet *pktin, void *ctx)
7976 unsigned *sizep = ctx;
7979 * Winadj responses should always be failures. However, at least
7980 * one server ("boks_sshd") is known to return SUCCESS for channel
7981 * requests it's never heard of, such as "winadj@putty". Raised
7982 * with foxt.com as bug 090916-090424, but for the sake of a quiet
7983 * life, we don't worry about what kind of response we got.
7986 c->v.v2.remlocwin += *sizep;
7989 * winadj messages are only sent when the window is fully open, so
7990 * if we get an ack of one, we know any pending unthrottle is
7993 if (c->v.v2.throttle_state == UNTHROTTLING)
7994 c->v.v2.throttle_state = UNTHROTTLED;
7997 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
7999 struct ssh_channel *c = ssh2_channel_msg(ssh, pktin);
8000 struct outstanding_channel_request *ocr;
8003 if (c->type == CHAN_SHARING) {
8004 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8005 pktin->body, pktin->length);
8008 ocr = c->v.v2.chanreq_head;
8010 ssh2_msg_unexpected(ssh, pktin);
8013 ocr->handler(c, pktin, ocr->ctx);
8014 c->v.v2.chanreq_head = ocr->next;
8017 * We may now initiate channel-closing procedures, if that
8018 * CHANNEL_REQUEST was the last thing outstanding before we send
8021 ssh2_channel_check_close(c);
8024 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
8026 struct ssh_channel *c;
8027 c = ssh2_channel_msg(ssh, pktin);
8030 if (c->type == CHAN_SHARING) {
8031 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8032 pktin->body, pktin->length);
8035 if (!(c->closes & CLOSES_SENT_EOF)) {
8036 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
8037 ssh2_try_send_and_unthrottle(ssh, c);
8041 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
8045 struct ssh_channel *c;
8046 c = ssh2_channel_msg(ssh, pktin);
8049 if (c->type == CHAN_SHARING) {
8050 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8051 pktin->body, pktin->length);
8054 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
8055 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
8056 return; /* extended but not stderr */
8057 ssh_pkt_getstring(pktin, &data, &length);
8060 c->v.v2.locwindow -= length;
8061 c->v.v2.remlocwin -= length;
8063 case CHAN_MAINSESSION:
8065 from_backend(ssh->frontend, pktin->type ==
8066 SSH2_MSG_CHANNEL_EXTENDED_DATA,
8070 bufsize = x11_send(c->u.x11.xconn, data, length);
8073 bufsize = pfd_send(c->u.pfd.pf, data, length);
8076 bufsize = ssh_agent_channel_data(c, data, length);
8080 * If it looks like the remote end hit the end of its window,
8081 * and we didn't want it to do that, think about using a
8084 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
8085 c->v.v2.locmaxwin < 0x40000000)
8086 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
8088 * If we are not buffering too much data,
8089 * enlarge the window again at the remote side.
8090 * If we are buffering too much, we may still
8091 * need to adjust the window if the server's
8094 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
8095 c->v.v2.locmaxwin - bufsize : 0);
8097 * If we're either buffering way too much data, or if we're
8098 * buffering anything at all and we're in "simple" mode,
8099 * throttle the whole channel.
8101 if ((bufsize > c->v.v2.locmaxwin || (ssh_is_simple(ssh) && bufsize>0))
8102 && !c->throttling_conn) {
8103 c->throttling_conn = 1;
8104 ssh_throttle_conn(ssh, +1);
8109 static void ssh_check_termination(Ssh ssh)
8111 if (ssh->version == 2 &&
8112 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
8113 (ssh->channels && count234(ssh->channels) == 0) &&
8114 !(ssh->connshare && share_ndownstreams(ssh->connshare) > 0)) {
8116 * We used to send SSH_MSG_DISCONNECT here, because I'd
8117 * believed that _every_ conforming SSH-2 connection had to
8118 * end with a disconnect being sent by at least one side;
8119 * apparently I was wrong and it's perfectly OK to
8120 * unceremoniously slam the connection shut when you're done,
8121 * and indeed OpenSSH feels this is more polite than sending a
8122 * DISCONNECT. So now we don't.
8124 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
8128 void ssh_sharing_downstream_connected(Ssh ssh, unsigned id,
8129 const char *peerinfo)
8132 logeventf(ssh, "Connection sharing downstream #%u connected from %s",
8135 logeventf(ssh, "Connection sharing downstream #%u connected", id);
8138 void ssh_sharing_downstream_disconnected(Ssh ssh, unsigned id)
8140 logeventf(ssh, "Connection sharing downstream #%u disconnected", id);
8141 ssh_check_termination(ssh);
8144 void ssh_sharing_logf(Ssh ssh, unsigned id, const char *logfmt, ...)
8149 va_start(ap, logfmt);
8150 buf = dupvprintf(logfmt, ap);
8153 logeventf(ssh, "Connection sharing downstream #%u: %s", id, buf);
8155 logeventf(ssh, "Connection sharing: %s", buf);
8159 static void ssh_channel_destroy(struct ssh_channel *c)
8164 case CHAN_MAINSESSION:
8165 ssh->mainchan = NULL;
8166 update_specials_menu(ssh->frontend);
8169 if (c->u.x11.xconn != NULL)
8170 x11_close(c->u.x11.xconn);
8171 logevent("Forwarded X11 connection terminated");
8174 sfree(c->u.a.message);
8177 if (c->u.pfd.pf != NULL)
8178 pfd_close(c->u.pfd.pf);
8179 logevent("Forwarded port closed");
8183 del234(ssh->channels, c);
8184 if (ssh->version == 2) {
8185 bufchain_clear(&c->v.v2.outbuffer);
8186 assert(c->v.v2.chanreq_head == NULL);
8191 * If that was the last channel left open, we might need to
8194 ssh_check_termination(ssh);
8197 static void ssh2_channel_check_close(struct ssh_channel *c)
8200 struct Packet *pktout;
8204 * If we've sent out our own CHANNEL_OPEN but not yet seen
8205 * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
8206 * it's too early to be sending close messages of any kind.
8211 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
8212 c->type == CHAN_ZOMBIE) &&
8213 !c->v.v2.chanreq_head &&
8214 !(c->closes & CLOSES_SENT_CLOSE)) {
8216 * We have both sent and received EOF (or the channel is a
8217 * zombie), and we have no outstanding channel requests, which
8218 * means the channel is in final wind-up. But we haven't sent
8219 * CLOSE, so let's do so now.
8221 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
8222 ssh2_pkt_adduint32(pktout, c->remoteid);
8223 ssh2_pkt_send(ssh, pktout);
8224 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
8227 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
8228 assert(c->v.v2.chanreq_head == NULL);
8230 * We have both sent and received CLOSE, which means we're
8231 * completely done with the channel.
8233 ssh_channel_destroy(c);
8237 static void ssh2_channel_got_eof(struct ssh_channel *c)
8239 if (c->closes & CLOSES_RCVD_EOF)
8240 return; /* already seen EOF */
8241 c->closes |= CLOSES_RCVD_EOF;
8243 if (c->type == CHAN_X11) {
8244 x11_send_eof(c->u.x11.xconn);
8245 } else if (c->type == CHAN_AGENT) {
8246 if (c->u.a.outstanding_requests == 0) {
8247 /* Manufacture an outgoing EOF in response to the incoming one. */
8248 sshfwd_write_eof(c);
8250 } else if (c->type == CHAN_SOCKDATA) {
8251 pfd_send_eof(c->u.pfd.pf);
8252 } else if (c->type == CHAN_MAINSESSION) {
8255 if (!ssh->sent_console_eof &&
8256 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
8258 * Either from_backend_eof told us that the front end
8259 * wants us to close the outgoing side of the connection
8260 * as soon as we see EOF from the far end, or else we've
8261 * unilaterally decided to do that because we've allocated
8262 * a remote pty and hence EOF isn't a particularly
8263 * meaningful concept.
8265 sshfwd_write_eof(c);
8267 ssh->sent_console_eof = TRUE;
8270 ssh2_channel_check_close(c);
8273 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
8275 struct ssh_channel *c;
8277 c = ssh2_channel_msg(ssh, pktin);
8280 if (c->type == CHAN_SHARING) {
8281 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8282 pktin->body, pktin->length);
8285 ssh2_channel_got_eof(c);
8288 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
8290 struct ssh_channel *c;
8292 c = ssh2_channel_msg(ssh, pktin);
8295 if (c->type == CHAN_SHARING) {
8296 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8297 pktin->body, pktin->length);
8302 * When we receive CLOSE on a channel, we assume it comes with an
8303 * implied EOF if we haven't seen EOF yet.
8305 ssh2_channel_got_eof(c);
8307 if (!(ssh->remote_bugs & BUG_SENDS_LATE_REQUEST_REPLY)) {
8309 * It also means we stop expecting to see replies to any
8310 * outstanding channel requests, so clean those up too.
8311 * (ssh_chanreq_init will enforce by assertion that we don't
8312 * subsequently put anything back on this list.)
8314 while (c->v.v2.chanreq_head) {
8315 struct outstanding_channel_request *ocr = c->v.v2.chanreq_head;
8316 ocr->handler(c, NULL, ocr->ctx);
8317 c->v.v2.chanreq_head = ocr->next;
8323 * And we also send an outgoing EOF, if we haven't already, on the
8324 * assumption that CLOSE is a pretty forceful announcement that
8325 * the remote side is doing away with the entire channel. (If it
8326 * had wanted to send us EOF and continue receiving data from us,
8327 * it would have just sent CHANNEL_EOF.)
8329 if (!(c->closes & CLOSES_SENT_EOF)) {
8331 * Make sure we don't read any more from whatever our local
8332 * data source is for this channel.
8335 case CHAN_MAINSESSION:
8336 ssh->send_ok = 0; /* stop trying to read from stdin */
8339 x11_override_throttle(c->u.x11.xconn, 1);
8342 pfd_override_throttle(c->u.pfd.pf, 1);
8347 * Abandon any buffered data we still wanted to send to this
8348 * channel. Receiving a CHANNEL_CLOSE is an indication that
8349 * the server really wants to get on and _destroy_ this
8350 * channel, and it isn't going to send us any further
8351 * WINDOW_ADJUSTs to permit us to send pending stuff.
8353 bufchain_clear(&c->v.v2.outbuffer);
8356 * Send outgoing EOF.
8358 sshfwd_write_eof(c);
8362 * Now process the actual close.
8364 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
8365 c->closes |= CLOSES_RCVD_CLOSE;
8366 ssh2_channel_check_close(c);
8370 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
8372 struct ssh_channel *c;
8374 c = ssh2_channel_msg(ssh, pktin);
8377 if (c->type == CHAN_SHARING) {
8378 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8379 pktin->body, pktin->length);
8382 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
8383 c->remoteid = ssh_pkt_getuint32(pktin);
8384 c->halfopen = FALSE;
8385 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8386 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
8388 if (c->type == CHAN_SOCKDATA_DORMANT) {
8389 c->type = CHAN_SOCKDATA;
8391 pfd_confirm(c->u.pfd.pf);
8392 } else if (c->type == CHAN_ZOMBIE) {
8394 * This case can occur if a local socket error occurred
8395 * between us sending out CHANNEL_OPEN and receiving
8396 * OPEN_CONFIRMATION. In this case, all we can do is
8397 * immediately initiate close proceedings now that we know the
8398 * server's id to put in the close message.
8400 ssh2_channel_check_close(c);
8403 * We never expect to receive OPEN_CONFIRMATION for any
8404 * *other* channel type (since only local-to-remote port
8405 * forwardings cause us to send CHANNEL_OPEN after the main
8406 * channel is live - all other auxiliary channel types are
8407 * initiated from the server end). It's safe to enforce this
8408 * by assertion rather than by ssh_disconnect, because the
8409 * real point is that we never constructed a half-open channel
8410 * structure in the first place with any type other than the
8413 assert(!"Funny channel type in ssh2_msg_channel_open_confirmation");
8417 ssh_channel_try_eof(c); /* in case we had a pending EOF */
8420 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
8422 static const char *const reasons[] = {
8423 "<unknown reason code>",
8424 "Administratively prohibited",
8426 "Unknown channel type",
8427 "Resource shortage",
8429 unsigned reason_code;
8430 char *reason_string;
8432 struct ssh_channel *c;
8434 c = ssh2_channel_msg(ssh, pktin);
8437 if (c->type == CHAN_SHARING) {
8438 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8439 pktin->body, pktin->length);
8442 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
8444 if (c->type == CHAN_SOCKDATA_DORMANT) {
8445 reason_code = ssh_pkt_getuint32(pktin);
8446 if (reason_code >= lenof(reasons))
8447 reason_code = 0; /* ensure reasons[reason_code] in range */
8448 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
8449 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
8450 reasons[reason_code], reason_length,
8451 NULLTOEMPTY(reason_string));
8453 pfd_close(c->u.pfd.pf);
8454 } else if (c->type == CHAN_ZOMBIE) {
8456 * This case can occur if a local socket error occurred
8457 * between us sending out CHANNEL_OPEN and receiving
8458 * OPEN_FAILURE. In this case, we need do nothing except allow
8459 * the code below to throw the half-open channel away.
8463 * We never expect to receive OPEN_FAILURE for any *other*
8464 * channel type (since only local-to-remote port forwardings
8465 * cause us to send CHANNEL_OPEN after the main channel is
8466 * live - all other auxiliary channel types are initiated from
8467 * the server end). It's safe to enforce this by assertion
8468 * rather than by ssh_disconnect, because the real point is
8469 * that we never constructed a half-open channel structure in
8470 * the first place with any type other than the above.
8472 assert(!"Funny channel type in ssh2_msg_channel_open_failure");
8475 del234(ssh->channels, c);
8479 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
8482 int typelen, want_reply;
8483 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
8484 struct ssh_channel *c;
8485 struct Packet *pktout;
8487 c = ssh2_channel_msg(ssh, pktin);
8490 if (c->type == CHAN_SHARING) {
8491 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8492 pktin->body, pktin->length);
8495 ssh_pkt_getstring(pktin, &type, &typelen);
8496 want_reply = ssh2_pkt_getbool(pktin);
8498 if (c->closes & CLOSES_SENT_CLOSE) {
8500 * We don't reply to channel requests after we've sent
8501 * CHANNEL_CLOSE for the channel, because our reply might
8502 * cross in the network with the other side's CHANNEL_CLOSE
8503 * and arrive after they have wound the channel up completely.
8509 * Having got the channel number, we now look at
8510 * the request type string to see if it's something
8513 if (c == ssh->mainchan) {
8515 * We recognise "exit-status" and "exit-signal" on
8516 * the primary channel.
8518 if (typelen == 11 &&
8519 !memcmp(type, "exit-status", 11)) {
8521 ssh->exitcode = ssh_pkt_getuint32(pktin);
8522 logeventf(ssh, "Server sent command exit status %d",
8524 reply = SSH2_MSG_CHANNEL_SUCCESS;
8526 } else if (typelen == 11 &&
8527 !memcmp(type, "exit-signal", 11)) {
8529 int is_plausible = TRUE, is_int = FALSE;
8530 char *fmt_sig = NULL, *fmt_msg = NULL;
8532 int msglen = 0, core = FALSE;
8533 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
8534 * provide an `int' for the signal, despite its
8535 * having been a `string' in the drafts of RFC 4254 since at
8536 * least 2001. (Fixed in session.c 1.147.) Try to
8537 * infer which we can safely parse it as. */
8539 unsigned char *p = pktin->body +
8541 long len = pktin->length - pktin->savedpos;
8542 unsigned long num = GET_32BIT(p); /* what is it? */
8543 /* If it's 0, it hardly matters; assume string */
8547 int maybe_int = FALSE, maybe_str = FALSE;
8548 #define CHECK_HYPOTHESIS(offset, result) \
8551 int q = toint(offset); \
8552 if (q >= 0 && q+4 <= len) { \
8553 q = toint(q + 4 + GET_32BIT(p+q)); \
8554 if (q >= 0 && q+4 <= len && \
8555 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
8560 CHECK_HYPOTHESIS(4+1, maybe_int);
8561 CHECK_HYPOTHESIS(4+num+1, maybe_str);
8562 #undef CHECK_HYPOTHESIS
8563 if (maybe_int && !maybe_str)
8565 else if (!maybe_int && maybe_str)
8568 /* Crikey. Either or neither. Panic. */
8569 is_plausible = FALSE;
8572 ssh->exitcode = 128; /* means `unknown signal' */
8575 /* Old non-standard OpenSSH. */
8576 int signum = ssh_pkt_getuint32(pktin);
8577 fmt_sig = dupprintf(" %d", signum);
8578 ssh->exitcode = 128 + signum;
8580 /* As per RFC 4254. */
8583 ssh_pkt_getstring(pktin, &sig, &siglen);
8584 /* Signal name isn't supposed to be blank, but
8585 * let's cope gracefully if it is. */
8587 fmt_sig = dupprintf(" \"%.*s\"",
8592 * Really hideous method of translating the
8593 * signal description back into a locally
8594 * meaningful number.
8599 #define TRANSLATE_SIGNAL(s) \
8600 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
8601 ssh->exitcode = 128 + SIG ## s
8603 TRANSLATE_SIGNAL(ABRT);
8606 TRANSLATE_SIGNAL(ALRM);
8609 TRANSLATE_SIGNAL(FPE);
8612 TRANSLATE_SIGNAL(HUP);
8615 TRANSLATE_SIGNAL(ILL);
8618 TRANSLATE_SIGNAL(INT);
8621 TRANSLATE_SIGNAL(KILL);
8624 TRANSLATE_SIGNAL(PIPE);
8627 TRANSLATE_SIGNAL(QUIT);
8630 TRANSLATE_SIGNAL(SEGV);
8633 TRANSLATE_SIGNAL(TERM);
8636 TRANSLATE_SIGNAL(USR1);
8639 TRANSLATE_SIGNAL(USR2);
8641 #undef TRANSLATE_SIGNAL
8643 ssh->exitcode = 128;
8645 core = ssh2_pkt_getbool(pktin);
8646 ssh_pkt_getstring(pktin, &msg, &msglen);
8648 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
8650 /* ignore lang tag */
8651 } /* else don't attempt to parse */
8652 logeventf(ssh, "Server exited on signal%s%s%s",
8653 fmt_sig ? fmt_sig : "",
8654 core ? " (core dumped)" : "",
8655 fmt_msg ? fmt_msg : "");
8658 reply = SSH2_MSG_CHANNEL_SUCCESS;
8663 * This is a channel request we don't know
8664 * about, so we now either ignore the request
8665 * or respond with CHANNEL_FAILURE, depending
8668 reply = SSH2_MSG_CHANNEL_FAILURE;
8671 pktout = ssh2_pkt_init(reply);
8672 ssh2_pkt_adduint32(pktout, c->remoteid);
8673 ssh2_pkt_send(ssh, pktout);
8677 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
8680 int typelen, want_reply;
8681 struct Packet *pktout;
8683 ssh_pkt_getstring(pktin, &type, &typelen);
8684 want_reply = ssh2_pkt_getbool(pktin);
8687 * We currently don't support any global requests
8688 * at all, so we either ignore the request or
8689 * respond with REQUEST_FAILURE, depending on
8693 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
8694 ssh2_pkt_send(ssh, pktout);
8698 struct X11FakeAuth *ssh_sharing_add_x11_display(Ssh ssh, int authtype,
8702 struct X11FakeAuth *auth;
8705 * Make up a new set of fake X11 auth data, and add it to the tree
8706 * of currently valid ones with an indication of the sharing
8707 * context that it's relevant to.
8709 auth = x11_invent_fake_auth(ssh->x11authtree, authtype);
8710 auth->share_cs = share_cs;
8711 auth->share_chan = share_chan;
8716 void ssh_sharing_remove_x11_display(Ssh ssh, struct X11FakeAuth *auth)
8718 del234(ssh->x11authtree, auth);
8719 x11_free_fake_auth(auth);
8722 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
8729 const char *error = NULL;
8730 struct ssh_channel *c;
8731 unsigned remid, winsize, pktsize;
8732 unsigned our_winsize_override = 0;
8733 struct Packet *pktout;
8735 ssh_pkt_getstring(pktin, &type, &typelen);
8736 c = snew(struct ssh_channel);
8739 remid = ssh_pkt_getuint32(pktin);
8740 winsize = ssh_pkt_getuint32(pktin);
8741 pktsize = ssh_pkt_getuint32(pktin);
8743 if (typelen == 3 && !memcmp(type, "x11", 3)) {
8746 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8747 addrstr = dupprintf("%.*s", peeraddrlen, NULLTOEMPTY(peeraddr));
8748 peerport = ssh_pkt_getuint32(pktin);
8750 logeventf(ssh, "Received X11 connect request from %s:%d",
8753 if (!ssh->X11_fwd_enabled && !ssh->connshare)
8754 error = "X11 forwarding is not enabled";
8756 c->u.x11.xconn = x11_init(ssh->x11authtree, c,
8759 c->u.x11.initial = TRUE;
8762 * If we are a connection-sharing upstream, then we should
8763 * initially present a very small window, adequate to take
8764 * the X11 initial authorisation packet but not much more.
8765 * Downstream will then present us a larger window (by
8766 * fiat of the connection-sharing protocol) and we can
8767 * guarantee to send a positive-valued WINDOW_ADJUST.
8770 our_winsize_override = 128;
8772 logevent("Opened X11 forward channel");
8776 } else if (typelen == 15 &&
8777 !memcmp(type, "forwarded-tcpip", 15)) {
8778 struct ssh_rportfwd pf, *realpf;
8781 ssh_pkt_getstring(pktin, &shost, &shostlen);/* skip address */
8782 pf.shost = dupprintf("%.*s", shostlen, NULLTOEMPTY(shost));
8783 pf.sport = ssh_pkt_getuint32(pktin);
8784 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8785 peerport = ssh_pkt_getuint32(pktin);
8786 realpf = find234(ssh->rportfwds, &pf, NULL);
8787 logeventf(ssh, "Received remote port %s:%d open request "
8788 "from %.*s:%d", pf.shost, pf.sport,
8789 peeraddrlen, NULLTOEMPTY(peeraddr), peerport);
8792 if (realpf == NULL) {
8793 error = "Remote port is not recognised";
8797 if (realpf->share_ctx) {
8799 * This port forwarding is on behalf of a
8800 * connection-sharing downstream, so abandon our own
8801 * channel-open procedure and just pass the message on
8804 share_got_pkt_from_server(realpf->share_ctx, pktin->type,
8805 pktin->body, pktin->length);
8810 err = pfd_connect(&c->u.pfd.pf, realpf->dhost, realpf->dport,
8811 c, ssh->conf, realpf->pfrec->addressfamily);
8812 logeventf(ssh, "Attempting to forward remote port to "
8813 "%s:%d", realpf->dhost, realpf->dport);
8815 logeventf(ssh, "Port open failed: %s", err);
8817 error = "Port open failed";
8819 logevent("Forwarded port opened successfully");
8820 c->type = CHAN_SOCKDATA;
8823 } else if (typelen == 22 &&
8824 !memcmp(type, "auth-agent@openssh.com", 22)) {
8825 if (!ssh->agentfwd_enabled)
8826 error = "Agent forwarding is not enabled";
8828 c->type = CHAN_AGENT; /* identify channel type */
8829 c->u.a.lensofar = 0;
8830 c->u.a.message = NULL;
8831 c->u.a.outstanding_requests = 0;
8834 error = "Unsupported channel type requested";
8837 c->remoteid = remid;
8838 c->halfopen = FALSE;
8840 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
8841 ssh2_pkt_adduint32(pktout, c->remoteid);
8842 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
8843 ssh2_pkt_addstring(pktout, error);
8844 ssh2_pkt_addstring(pktout, "en"); /* language tag */
8845 ssh2_pkt_send(ssh, pktout);
8846 logeventf(ssh, "Rejected channel open: %s", error);
8849 ssh2_channel_init(c);
8850 c->v.v2.remwindow = winsize;
8851 c->v.v2.remmaxpkt = pktsize;
8852 if (our_winsize_override) {
8853 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
8854 our_winsize_override;
8856 add234(ssh->channels, c);
8857 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
8858 ssh2_pkt_adduint32(pktout, c->remoteid);
8859 ssh2_pkt_adduint32(pktout, c->localid);
8860 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
8861 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8862 ssh2_pkt_send(ssh, pktout);
8866 void sshfwd_x11_sharing_handover(struct ssh_channel *c,
8867 void *share_cs, void *share_chan,
8868 const char *peer_addr, int peer_port,
8869 int endian, int protomajor, int protominor,
8870 const void *initial_data, int initial_len)
8873 * This function is called when we've just discovered that an X
8874 * forwarding channel on which we'd been handling the initial auth
8875 * ourselves turns out to be destined for a connection-sharing
8876 * downstream. So we turn the channel into a CHAN_SHARING, meaning
8877 * that we completely stop tracking windows and buffering data and
8878 * just pass more or less unmodified SSH messages back and forth.
8880 c->type = CHAN_SHARING;
8881 c->u.sharing.ctx = share_cs;
8882 share_setup_x11_channel(share_cs, share_chan,
8883 c->localid, c->remoteid, c->v.v2.remwindow,
8884 c->v.v2.remmaxpkt, c->v.v2.locwindow,
8885 peer_addr, peer_port, endian,
8886 protomajor, protominor,
8887 initial_data, initial_len);
8890 void sshfwd_x11_is_local(struct ssh_channel *c)
8893 * This function is called when we've just discovered that an X
8894 * forwarding channel is _not_ destined for a connection-sharing
8895 * downstream but we're going to handle it ourselves. We stop
8896 * presenting a cautiously small window and go into ordinary data
8899 c->u.x11.initial = FALSE;
8900 ssh2_set_window(c, ssh_is_simple(c->ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE);
8904 * Buffer banner messages for later display at some convenient point,
8905 * if we're going to display them.
8907 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
8909 /* Arbitrary limit to prevent unbounded inflation of buffer */
8910 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
8911 bufchain_size(&ssh->banner) <= 131072) {
8912 char *banner = NULL;
8914 ssh_pkt_getstring(pktin, &banner, &size);
8916 bufchain_add(&ssh->banner, banner, size);
8920 /* Helper function to deal with sending tty modes for "pty-req" */
8921 static void ssh2_send_ttymode(void *data, char *mode, char *val)
8923 struct Packet *pktout = (struct Packet *)data;
8925 unsigned int arg = 0;
8926 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
8927 if (i == lenof(ssh_ttymodes)) return;
8928 switch (ssh_ttymodes[i].type) {
8930 arg = ssh_tty_parse_specchar(val);
8933 arg = ssh_tty_parse_boolean(val);
8936 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
8937 ssh2_pkt_adduint32(pktout, arg);
8940 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
8943 struct ssh2_setup_x11_state {
8947 struct Packet *pktout;
8948 crStateP(ssh2_setup_x11_state, ctx);
8952 logevent("Requesting X11 forwarding");
8953 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
8955 ssh2_pkt_addbool(pktout, 0); /* many connections */
8956 ssh2_pkt_addstring(pktout, ssh->x11auth->protoname);
8957 ssh2_pkt_addstring(pktout, ssh->x11auth->datastring);
8958 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
8959 ssh2_pkt_send(ssh, pktout);
8961 /* Wait to be called back with either a response packet, or NULL
8962 * meaning clean up and free our data */
8966 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8967 logevent("X11 forwarding enabled");
8968 ssh->X11_fwd_enabled = TRUE;
8970 logevent("X11 forwarding refused");
8976 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
8979 struct ssh2_setup_agent_state {
8983 struct Packet *pktout;
8984 crStateP(ssh2_setup_agent_state, ctx);
8988 logevent("Requesting OpenSSH-style agent forwarding");
8989 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
8990 ssh2_setup_agent, s);
8991 ssh2_pkt_send(ssh, pktout);
8993 /* Wait to be called back with either a response packet, or NULL
8994 * meaning clean up and free our data */
8998 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8999 logevent("Agent forwarding enabled");
9000 ssh->agentfwd_enabled = TRUE;
9002 logevent("Agent forwarding refused");
9008 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
9011 struct ssh2_setup_pty_state {
9015 struct Packet *pktout;
9016 crStateP(ssh2_setup_pty_state, ctx);
9020 /* Unpick the terminal-speed string. */
9021 /* XXX perhaps we should allow no speeds to be sent. */
9022 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
9023 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
9024 /* Build the pty request. */
9025 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
9027 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
9028 ssh2_pkt_adduint32(pktout, ssh->term_width);
9029 ssh2_pkt_adduint32(pktout, ssh->term_height);
9030 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
9031 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
9032 ssh2_pkt_addstring_start(pktout);
9033 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
9034 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
9035 ssh2_pkt_adduint32(pktout, ssh->ispeed);
9036 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
9037 ssh2_pkt_adduint32(pktout, ssh->ospeed);
9038 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
9039 ssh2_pkt_send(ssh, pktout);
9040 ssh->state = SSH_STATE_INTERMED;
9042 /* Wait to be called back with either a response packet, or NULL
9043 * meaning clean up and free our data */
9047 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
9048 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
9049 ssh->ospeed, ssh->ispeed);
9050 ssh->got_pty = TRUE;
9052 c_write_str(ssh, "Server refused to allocate pty\r\n");
9053 ssh->editing = ssh->echoing = 1;
9060 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
9063 struct ssh2_setup_env_state {
9065 int num_env, env_left, env_ok;
9068 struct Packet *pktout;
9069 crStateP(ssh2_setup_env_state, ctx);
9074 * Send environment variables.
9076 * Simplest thing here is to send all the requests at once, and
9077 * then wait for a whole bunch of successes or failures.
9083 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
9085 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
9086 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
9087 ssh2_pkt_addstring(pktout, key);
9088 ssh2_pkt_addstring(pktout, val);
9089 ssh2_pkt_send(ssh, pktout);
9094 logeventf(ssh, "Sent %d environment variables", s->num_env);
9099 s->env_left = s->num_env;
9101 while (s->env_left > 0) {
9102 /* Wait to be called back with either a response packet,
9103 * or NULL meaning clean up and free our data */
9105 if (!pktin) goto out;
9106 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
9111 if (s->env_ok == s->num_env) {
9112 logevent("All environment variables successfully set");
9113 } else if (s->env_ok == 0) {
9114 logevent("All environment variables refused");
9115 c_write_str(ssh, "Server refused to set environment variables\r\n");
9117 logeventf(ssh, "%d environment variables refused",
9118 s->num_env - s->env_ok);
9119 c_write_str(ssh, "Server refused to set all environment variables\r\n");
9127 * Handle the SSH-2 userauth and connection layers.
9129 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
9131 do_ssh2_authconn(ssh, NULL, 0, pktin);
9134 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
9138 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
9141 static void do_ssh2_authconn(Ssh ssh, const unsigned char *in, int inlen,
9142 struct Packet *pktin)
9144 struct do_ssh2_authconn_state {
9148 AUTH_TYPE_PUBLICKEY,
9149 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
9150 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
9152 AUTH_TYPE_GSSAPI, /* always QUIET */
9153 AUTH_TYPE_KEYBOARD_INTERACTIVE,
9154 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
9156 int done_service_req;
9157 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
9158 int tried_pubkey_config, done_agent;
9163 int kbd_inter_refused;
9164 int we_are_in, userauth_success;
9165 prompts_t *cur_prompt;
9170 void *publickey_blob;
9171 int publickey_bloblen;
9172 int privatekey_available, privatekey_encrypted;
9173 char *publickey_algorithm;
9174 char *publickey_comment;
9175 unsigned char agent_request[5], *agent_response, *agentp;
9176 int agent_responselen;
9177 unsigned char *pkblob_in_agent;
9179 char *pkblob, *alg, *commentp;
9180 int pklen, alglen, commentlen;
9181 int siglen, retlen, len;
9182 char *q, *agentreq, *ret;
9183 struct Packet *pktout;
9186 struct ssh_gss_library *gsslib;
9187 Ssh_gss_ctx gss_ctx;
9188 Ssh_gss_buf gss_buf;
9189 Ssh_gss_buf gss_rcvtok, gss_sndtok;
9190 Ssh_gss_name gss_srv_name;
9191 Ssh_gss_stat gss_stat;
9194 crState(do_ssh2_authconn_state);
9198 /* Register as a handler for all the messages this coroutine handles. */
9199 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
9200 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
9201 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
9202 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
9203 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
9204 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
9205 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
9206 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
9207 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
9208 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
9209 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
9210 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
9211 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
9212 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
9213 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
9214 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
9215 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
9216 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
9217 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
9218 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
9220 s->done_service_req = FALSE;
9221 s->we_are_in = s->userauth_success = FALSE;
9222 s->agent_response = NULL;
9224 s->tried_gssapi = FALSE;
9227 if (!ssh->bare_connection) {
9228 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
9230 * Request userauth protocol, and await a response to it.
9232 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
9233 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
9234 ssh2_pkt_send(ssh, s->pktout);
9235 crWaitUntilV(pktin);
9236 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
9237 s->done_service_req = TRUE;
9239 if (!s->done_service_req) {
9241 * Request connection protocol directly, without authentication.
9243 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
9244 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9245 ssh2_pkt_send(ssh, s->pktout);
9246 crWaitUntilV(pktin);
9247 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
9248 s->we_are_in = TRUE; /* no auth required */
9250 bombout(("Server refused service request"));
9255 s->we_are_in = TRUE;
9258 /* Arrange to be able to deal with any BANNERs that come in.
9259 * (We do this now as packets may come in during the next bit.) */
9260 bufchain_init(&ssh->banner);
9261 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
9262 ssh2_msg_userauth_banner;
9265 * Misc one-time setup for authentication.
9267 s->publickey_blob = NULL;
9268 if (!s->we_are_in) {
9271 * Load the public half of any configured public key file
9274 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9275 if (!filename_is_null(s->keyfile)) {
9277 logeventf(ssh, "Reading key file \"%.150s\"",
9278 filename_to_str(s->keyfile));
9279 keytype = key_type(s->keyfile);
9280 if (keytype == SSH_KEYTYPE_SSH2 ||
9281 keytype == SSH_KEYTYPE_SSH2_PUBLIC_RFC4716 ||
9282 keytype == SSH_KEYTYPE_SSH2_PUBLIC_OPENSSH) {
9285 ssh2_userkey_loadpub(s->keyfile,
9286 &s->publickey_algorithm,
9287 &s->publickey_bloblen,
9288 &s->publickey_comment, &error);
9289 if (s->publickey_blob) {
9290 s->privatekey_available = (keytype == SSH_KEYTYPE_SSH2);
9291 if (!s->privatekey_available)
9292 logeventf(ssh, "Key file contains public key only");
9293 s->privatekey_encrypted =
9294 ssh2_userkey_encrypted(s->keyfile, NULL);
9297 logeventf(ssh, "Unable to load key (%s)",
9299 msgbuf = dupprintf("Unable to load key file "
9300 "\"%.150s\" (%s)\r\n",
9301 filename_to_str(s->keyfile),
9303 c_write_str(ssh, msgbuf);
9308 logeventf(ssh, "Unable to use this key file (%s)",
9309 key_type_to_str(keytype));
9310 msgbuf = dupprintf("Unable to use key file \"%.150s\""
9312 filename_to_str(s->keyfile),
9313 key_type_to_str(keytype));
9314 c_write_str(ssh, msgbuf);
9316 s->publickey_blob = NULL;
9321 * Find out about any keys Pageant has (but if there's a
9322 * public key configured, filter out all others).
9325 s->agent_response = NULL;
9326 s->pkblob_in_agent = NULL;
9327 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
9331 logevent("Pageant is running. Requesting keys.");
9333 /* Request the keys held by the agent. */
9334 PUT_32BIT(s->agent_request, 1);
9335 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
9336 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
9337 ssh_agent_callback, ssh)) {
9341 bombout(("Unexpected data from server while"
9342 " waiting for agent response"));
9345 } while (pktin || inlen > 0);
9346 r = ssh->agent_response;
9347 s->agent_responselen = ssh->agent_response_len;
9349 s->agent_response = (unsigned char *) r;
9350 if (s->agent_response && s->agent_responselen >= 5 &&
9351 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
9354 p = s->agent_response + 5;
9355 s->nkeys = toint(GET_32BIT(p));
9358 * Vet the Pageant response to ensure that the key
9359 * count and blob lengths make sense.
9362 logeventf(ssh, "Pageant response contained a negative"
9363 " key count %d", s->nkeys);
9365 goto done_agent_query;
9367 unsigned char *q = p + 4;
9368 int lenleft = s->agent_responselen - 5 - 4;
9370 for (keyi = 0; keyi < s->nkeys; keyi++) {
9371 int bloblen, commentlen;
9373 logeventf(ssh, "Pageant response was truncated");
9375 goto done_agent_query;
9377 bloblen = toint(GET_32BIT(q));
9378 if (bloblen < 0 || bloblen > lenleft) {
9379 logeventf(ssh, "Pageant response was truncated");
9381 goto done_agent_query;
9383 lenleft -= 4 + bloblen;
9385 commentlen = toint(GET_32BIT(q));
9386 if (commentlen < 0 || commentlen > lenleft) {
9387 logeventf(ssh, "Pageant response was truncated");
9389 goto done_agent_query;
9391 lenleft -= 4 + commentlen;
9392 q += 4 + commentlen;
9397 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
9398 if (s->publickey_blob) {
9399 /* See if configured key is in agent. */
9400 for (keyi = 0; keyi < s->nkeys; keyi++) {
9401 s->pklen = toint(GET_32BIT(p));
9402 if (s->pklen == s->publickey_bloblen &&
9403 !memcmp(p+4, s->publickey_blob,
9404 s->publickey_bloblen)) {
9405 logeventf(ssh, "Pageant key #%d matches "
9406 "configured key file", keyi);
9408 s->pkblob_in_agent = p;
9412 p += toint(GET_32BIT(p)) + 4; /* comment */
9414 if (!s->pkblob_in_agent) {
9415 logevent("Configured key file not in Pageant");
9420 logevent("Failed to get reply from Pageant");
9428 * We repeat this whole loop, including the username prompt,
9429 * until we manage a successful authentication. If the user
9430 * types the wrong _password_, they can be sent back to the
9431 * beginning to try another username, if this is configured on.
9432 * (If they specify a username in the config, they are never
9433 * asked, even if they do give a wrong password.)
9435 * I think this best serves the needs of
9437 * - the people who have no configuration, no keys, and just
9438 * want to try repeated (username,password) pairs until they
9439 * type both correctly
9441 * - people who have keys and configuration but occasionally
9442 * need to fall back to passwords
9444 * - people with a key held in Pageant, who might not have
9445 * logged in to a particular machine before; so they want to
9446 * type a username, and then _either_ their key will be
9447 * accepted, _or_ they will type a password. If they mistype
9448 * the username they will want to be able to get back and
9451 s->got_username = FALSE;
9452 while (!s->we_are_in) {
9456 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
9458 * We got a username last time round this loop, and
9459 * with change_username turned off we don't try to get
9462 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
9463 int ret; /* need not be kept over crReturn */
9464 s->cur_prompt = new_prompts(ssh->frontend);
9465 s->cur_prompt->to_server = TRUE;
9466 s->cur_prompt->name = dupstr("SSH login name");
9467 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
9468 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9471 crWaitUntilV(!pktin);
9472 ret = get_userpass_input(s->cur_prompt, in, inlen);
9477 * get_userpass_input() failed to get a username.
9480 free_prompts(s->cur_prompt);
9481 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
9484 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
9485 free_prompts(s->cur_prompt);
9488 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
9489 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
9490 c_write_str(ssh, stuff);
9494 s->got_username = TRUE;
9497 * Send an authentication request using method "none": (a)
9498 * just in case it succeeds, and (b) so that we know what
9499 * authentication methods we can usefully try next.
9501 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9503 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9504 ssh2_pkt_addstring(s->pktout, ssh->username);
9505 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
9506 ssh2_pkt_addstring(s->pktout, "none"); /* method */
9507 ssh2_pkt_send(ssh, s->pktout);
9508 s->type = AUTH_TYPE_NONE;
9510 s->we_are_in = FALSE;
9512 s->tried_pubkey_config = FALSE;
9513 s->kbd_inter_refused = FALSE;
9515 /* Reset agent request state. */
9516 s->done_agent = FALSE;
9517 if (s->agent_response) {
9518 if (s->pkblob_in_agent) {
9519 s->agentp = s->pkblob_in_agent;
9521 s->agentp = s->agent_response + 5 + 4;
9527 char *methods = NULL;
9531 * Wait for the result of the last authentication request.
9534 crWaitUntilV(pktin);
9536 * Now is a convenient point to spew any banner material
9537 * that we've accumulated. (This should ensure that when
9538 * we exit the auth loop, we haven't any left to deal
9542 int size = bufchain_size(&ssh->banner);
9544 * Don't show the banner if we're operating in
9545 * non-verbose non-interactive mode. (It's probably
9546 * a script, which means nobody will read the
9547 * banner _anyway_, and moreover the printing of
9548 * the banner will screw up processing on the
9549 * output of (say) plink.)
9551 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
9552 char *banner = snewn(size, char);
9553 bufchain_fetch(&ssh->banner, banner, size);
9554 c_write_untrusted(ssh, banner, size);
9557 bufchain_clear(&ssh->banner);
9559 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
9560 logevent("Access granted");
9561 s->we_are_in = s->userauth_success = TRUE;
9565 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
9566 bombout(("Strange packet received during authentication: "
9567 "type %d", pktin->type));
9574 * OK, we're now sitting on a USERAUTH_FAILURE message, so
9575 * we can look at the string in it and know what we can
9576 * helpfully try next.
9578 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
9579 ssh_pkt_getstring(pktin, &methods, &methlen);
9580 if (!ssh2_pkt_getbool(pktin)) {
9582 * We have received an unequivocal Access
9583 * Denied. This can translate to a variety of
9584 * messages, or no message at all.
9586 * For forms of authentication which are attempted
9587 * implicitly, by which I mean without printing
9588 * anything in the window indicating that we're
9589 * trying them, we should never print 'Access
9592 * If we do print a message saying that we're
9593 * attempting some kind of authentication, it's OK
9594 * to print a followup message saying it failed -
9595 * but the message may sometimes be more specific
9596 * than simply 'Access denied'.
9598 * Additionally, if we'd just tried password
9599 * authentication, we should break out of this
9600 * whole loop so as to go back to the username
9601 * prompt (iff we're configured to allow
9602 * username change attempts).
9604 if (s->type == AUTH_TYPE_NONE) {
9606 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
9607 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
9608 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
9609 c_write_str(ssh, "Server refused our key\r\n");
9610 logevent("Server refused our key");
9611 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
9612 /* This _shouldn't_ happen except by a
9613 * protocol bug causing client and server to
9614 * disagree on what is a correct signature. */
9615 c_write_str(ssh, "Server refused public-key signature"
9616 " despite accepting key!\r\n");
9617 logevent("Server refused public-key signature"
9618 " despite accepting key!");
9619 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
9620 /* quiet, so no c_write */
9621 logevent("Server refused keyboard-interactive authentication");
9622 } else if (s->type==AUTH_TYPE_GSSAPI) {
9623 /* always quiet, so no c_write */
9624 /* also, the code down in the GSSAPI block has
9625 * already logged this in the Event Log */
9626 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
9627 logevent("Keyboard-interactive authentication failed");
9628 c_write_str(ssh, "Access denied\r\n");
9630 assert(s->type == AUTH_TYPE_PASSWORD);
9631 logevent("Password authentication failed");
9632 c_write_str(ssh, "Access denied\r\n");
9634 if (conf_get_int(ssh->conf, CONF_change_username)) {
9635 /* XXX perhaps we should allow
9636 * keyboard-interactive to do this too? */
9637 s->we_are_in = FALSE;
9642 c_write_str(ssh, "Further authentication required\r\n");
9643 logevent("Further authentication required");
9647 in_commasep_string("publickey", methods, methlen);
9649 in_commasep_string("password", methods, methlen);
9650 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
9651 in_commasep_string("keyboard-interactive", methods, methlen);
9653 if (conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
9654 in_commasep_string("gssapi-with-mic", methods, methlen)) {
9655 /* Try loading the GSS libraries and see if we
9658 ssh->gsslibs = ssh_gss_setup(ssh->conf);
9659 s->can_gssapi = (ssh->gsslibs->nlibraries > 0);
9661 /* No point in even bothering to try to load the
9662 * GSS libraries, if the user configuration and
9663 * server aren't both prepared to attempt GSSAPI
9664 * auth in the first place. */
9665 s->can_gssapi = FALSE;
9670 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9672 if (s->can_pubkey && !s->done_agent && s->nkeys) {
9675 * Attempt public-key authentication using a key from Pageant.
9678 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9680 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
9682 /* Unpack key from agent response */
9683 s->pklen = toint(GET_32BIT(s->agentp));
9685 s->pkblob = (char *)s->agentp;
9686 s->agentp += s->pklen;
9687 s->alglen = toint(GET_32BIT(s->pkblob));
9688 s->alg = s->pkblob + 4;
9689 s->commentlen = toint(GET_32BIT(s->agentp));
9691 s->commentp = (char *)s->agentp;
9692 s->agentp += s->commentlen;
9693 /* s->agentp now points at next key, if any */
9695 /* See if server will accept it */
9696 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9697 ssh2_pkt_addstring(s->pktout, ssh->username);
9698 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9699 /* service requested */
9700 ssh2_pkt_addstring(s->pktout, "publickey");
9702 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
9703 ssh2_pkt_addstring_start(s->pktout);
9704 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9705 ssh2_pkt_addstring_start(s->pktout);
9706 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9707 ssh2_pkt_send(ssh, s->pktout);
9708 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
9710 crWaitUntilV(pktin);
9711 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9713 /* Offer of key refused. */
9720 if (flags & FLAG_VERBOSE) {
9721 c_write_str(ssh, "Authenticating with "
9723 c_write(ssh, s->commentp, s->commentlen);
9724 c_write_str(ssh, "\" from agent\r\n");
9728 * Server is willing to accept the key.
9729 * Construct a SIGN_REQUEST.
9731 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9732 ssh2_pkt_addstring(s->pktout, ssh->username);
9733 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9734 /* service requested */
9735 ssh2_pkt_addstring(s->pktout, "publickey");
9737 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
9738 ssh2_pkt_addstring_start(s->pktout);
9739 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9740 ssh2_pkt_addstring_start(s->pktout);
9741 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9743 /* Ask agent for signature. */
9744 s->siglen = s->pktout->length - 5 + 4 +
9745 ssh->v2_session_id_len;
9746 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9748 s->len = 1; /* message type */
9749 s->len += 4 + s->pklen; /* key blob */
9750 s->len += 4 + s->siglen; /* data to sign */
9751 s->len += 4; /* flags */
9752 s->agentreq = snewn(4 + s->len, char);
9753 PUT_32BIT(s->agentreq, s->len);
9754 s->q = s->agentreq + 4;
9755 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
9756 PUT_32BIT(s->q, s->pklen);
9758 memcpy(s->q, s->pkblob, s->pklen);
9760 PUT_32BIT(s->q, s->siglen);
9762 /* Now the data to be signed... */
9763 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9764 PUT_32BIT(s->q, ssh->v2_session_id_len);
9767 memcpy(s->q, ssh->v2_session_id,
9768 ssh->v2_session_id_len);
9769 s->q += ssh->v2_session_id_len;
9770 memcpy(s->q, s->pktout->data + 5,
9771 s->pktout->length - 5);
9772 s->q += s->pktout->length - 5;
9773 /* And finally the (zero) flags word. */
9775 if (!agent_query(s->agentreq, s->len + 4,
9777 ssh_agent_callback, ssh)) {
9781 bombout(("Unexpected data from server"
9782 " while waiting for agent"
9786 } while (pktin || inlen > 0);
9787 vret = ssh->agent_response;
9788 s->retlen = ssh->agent_response_len;
9793 if (s->retlen >= 9 &&
9794 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
9795 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
9796 logevent("Sending Pageant's response");
9797 ssh2_add_sigblob(ssh, s->pktout,
9798 s->pkblob, s->pklen,
9800 GET_32BIT(s->ret + 5));
9801 ssh2_pkt_send(ssh, s->pktout);
9802 s->type = AUTH_TYPE_PUBLICKEY;
9804 /* FIXME: less drastic response */
9805 bombout(("Pageant failed to answer challenge"));
9811 /* Do we have any keys left to try? */
9812 if (s->pkblob_in_agent) {
9813 s->done_agent = TRUE;
9814 s->tried_pubkey_config = TRUE;
9817 if (s->keyi >= s->nkeys)
9818 s->done_agent = TRUE;
9821 } else if (s->can_pubkey && s->publickey_blob &&
9822 s->privatekey_available && !s->tried_pubkey_config) {
9824 struct ssh2_userkey *key; /* not live over crReturn */
9825 char *passphrase; /* not live over crReturn */
9827 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9829 s->tried_pubkey_config = TRUE;
9832 * Try the public key supplied in the configuration.
9834 * First, offer the public blob to see if the server is
9835 * willing to accept it.
9837 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9838 ssh2_pkt_addstring(s->pktout, ssh->username);
9839 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9840 /* service requested */
9841 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
9842 ssh2_pkt_addbool(s->pktout, FALSE);
9843 /* no signature included */
9844 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
9845 ssh2_pkt_addstring_start(s->pktout);
9846 ssh2_pkt_addstring_data(s->pktout,
9847 (char *)s->publickey_blob,
9848 s->publickey_bloblen);
9849 ssh2_pkt_send(ssh, s->pktout);
9850 logevent("Offered public key");
9852 crWaitUntilV(pktin);
9853 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9854 /* Key refused. Give up. */
9855 s->gotit = TRUE; /* reconsider message next loop */
9856 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
9857 continue; /* process this new message */
9859 logevent("Offer of public key accepted");
9862 * Actually attempt a serious authentication using
9865 if (flags & FLAG_VERBOSE) {
9866 c_write_str(ssh, "Authenticating with public key \"");
9867 c_write_str(ssh, s->publickey_comment);
9868 c_write_str(ssh, "\"\r\n");
9872 const char *error; /* not live over crReturn */
9873 if (s->privatekey_encrypted) {
9875 * Get a passphrase from the user.
9877 int ret; /* need not be kept over crReturn */
9878 s->cur_prompt = new_prompts(ssh->frontend);
9879 s->cur_prompt->to_server = FALSE;
9880 s->cur_prompt->name = dupstr("SSH key passphrase");
9881 add_prompt(s->cur_prompt,
9882 dupprintf("Passphrase for key \"%.100s\": ",
9883 s->publickey_comment),
9885 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9888 crWaitUntilV(!pktin);
9889 ret = get_userpass_input(s->cur_prompt,
9894 /* Failed to get a passphrase. Terminate. */
9895 free_prompts(s->cur_prompt);
9896 ssh_disconnect(ssh, NULL,
9897 "Unable to authenticate",
9898 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9903 dupstr(s->cur_prompt->prompts[0]->result);
9904 free_prompts(s->cur_prompt);
9906 passphrase = NULL; /* no passphrase needed */
9910 * Try decrypting the key.
9912 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9913 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
9915 /* burn the evidence */
9916 smemclr(passphrase, strlen(passphrase));
9919 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
9921 (key == SSH2_WRONG_PASSPHRASE)) {
9922 c_write_str(ssh, "Wrong passphrase\r\n");
9924 /* and loop again */
9926 c_write_str(ssh, "Unable to load private key (");
9927 c_write_str(ssh, error);
9928 c_write_str(ssh, ")\r\n");
9930 break; /* try something else */
9936 unsigned char *pkblob, *sigblob, *sigdata;
9937 int pkblob_len, sigblob_len, sigdata_len;
9941 * We have loaded the private key and the server
9942 * has announced that it's willing to accept it.
9943 * Hallelujah. Generate a signature and send it.
9945 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9946 ssh2_pkt_addstring(s->pktout, ssh->username);
9947 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9948 /* service requested */
9949 ssh2_pkt_addstring(s->pktout, "publickey");
9951 ssh2_pkt_addbool(s->pktout, TRUE);
9952 /* signature follows */
9953 ssh2_pkt_addstring(s->pktout, key->alg->name);
9954 pkblob = key->alg->public_blob(key->data,
9956 ssh2_pkt_addstring_start(s->pktout);
9957 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
9961 * The data to be signed is:
9965 * followed by everything so far placed in the
9968 sigdata_len = s->pktout->length - 5 + 4 +
9969 ssh->v2_session_id_len;
9970 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9972 sigdata = snewn(sigdata_len, unsigned char);
9974 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9975 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
9978 memcpy(sigdata+p, ssh->v2_session_id,
9979 ssh->v2_session_id_len);
9980 p += ssh->v2_session_id_len;
9981 memcpy(sigdata+p, s->pktout->data + 5,
9982 s->pktout->length - 5);
9983 p += s->pktout->length - 5;
9984 assert(p == sigdata_len);
9985 sigblob = key->alg->sign(key->data, (char *)sigdata,
9986 sigdata_len, &sigblob_len);
9987 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
9988 sigblob, sigblob_len);
9993 ssh2_pkt_send(ssh, s->pktout);
9994 logevent("Sent public key signature");
9995 s->type = AUTH_TYPE_PUBLICKEY;
9996 key->alg->freekey(key->data);
9997 sfree(key->comment);
10002 } else if (s->can_gssapi && !s->tried_gssapi) {
10004 /* GSSAPI Authentication */
10006 int micoffset, len;
10009 s->type = AUTH_TYPE_GSSAPI;
10010 s->tried_gssapi = TRUE;
10012 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
10015 * Pick the highest GSS library on the preference
10021 for (i = 0; i < ngsslibs; i++) {
10022 int want_id = conf_get_int_int(ssh->conf,
10023 CONF_ssh_gsslist, i);
10024 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
10025 if (ssh->gsslibs->libraries[j].id == want_id) {
10026 s->gsslib = &ssh->gsslibs->libraries[j];
10027 goto got_gsslib; /* double break */
10032 * We always expect to have found something in
10033 * the above loop: we only came here if there
10034 * was at least one viable GSS library, and the
10035 * preference list should always mention
10036 * everything and only change the order.
10041 if (s->gsslib->gsslogmsg)
10042 logevent(s->gsslib->gsslogmsg);
10044 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
10045 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10046 ssh2_pkt_addstring(s->pktout, ssh->username);
10047 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10048 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
10049 logevent("Attempting GSSAPI authentication");
10051 /* add mechanism info */
10052 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
10054 /* number of GSSAPI mechanisms */
10055 ssh2_pkt_adduint32(s->pktout,1);
10057 /* length of OID + 2 */
10058 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
10059 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
10061 /* length of OID */
10062 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
10064 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
10065 s->gss_buf.length);
10066 ssh2_pkt_send(ssh, s->pktout);
10067 crWaitUntilV(pktin);
10068 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
10069 logevent("GSSAPI authentication request refused");
10073 /* check returned packet ... */
10075 ssh_pkt_getstring(pktin, &data, &len);
10076 s->gss_rcvtok.value = data;
10077 s->gss_rcvtok.length = len;
10078 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
10079 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
10080 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
10081 memcmp((char *)s->gss_rcvtok.value + 2,
10082 s->gss_buf.value,s->gss_buf.length) ) {
10083 logevent("GSSAPI authentication - wrong response from server");
10087 /* now start running */
10088 s->gss_stat = s->gsslib->import_name(s->gsslib,
10091 if (s->gss_stat != SSH_GSS_OK) {
10092 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
10093 logevent("GSSAPI import name failed - Bad service name");
10095 logevent("GSSAPI import name failed");
10099 /* fetch TGT into GSS engine */
10100 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
10102 if (s->gss_stat != SSH_GSS_OK) {
10103 logevent("GSSAPI authentication failed to get credentials");
10104 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
10108 /* initial tokens are empty */
10109 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
10110 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
10112 /* now enter the loop */
10114 s->gss_stat = s->gsslib->init_sec_context
10118 conf_get_int(ssh->conf, CONF_gssapifwd),
10122 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
10123 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
10124 logevent("GSSAPI authentication initialisation failed");
10126 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
10127 &s->gss_buf) == SSH_GSS_OK) {
10128 logevent(s->gss_buf.value);
10129 sfree(s->gss_buf.value);
10134 logevent("GSSAPI authentication initialised");
10136 /* Client and server now exchange tokens until GSSAPI
10137 * no longer says CONTINUE_NEEDED */
10139 if (s->gss_sndtok.length != 0) {
10140 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
10141 ssh_pkt_addstring_start(s->pktout);
10142 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
10143 ssh2_pkt_send(ssh, s->pktout);
10144 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
10147 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
10148 crWaitUntilV(pktin);
10149 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
10150 logevent("GSSAPI authentication - bad server response");
10151 s->gss_stat = SSH_GSS_FAILURE;
10154 ssh_pkt_getstring(pktin, &data, &len);
10155 s->gss_rcvtok.value = data;
10156 s->gss_rcvtok.length = len;
10158 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
10160 if (s->gss_stat != SSH_GSS_OK) {
10161 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
10162 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
10165 logevent("GSSAPI authentication loop finished OK");
10167 /* Now send the MIC */
10169 s->pktout = ssh2_pkt_init(0);
10170 micoffset = s->pktout->length;
10171 ssh_pkt_addstring_start(s->pktout);
10172 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
10173 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
10174 ssh_pkt_addstring(s->pktout, ssh->username);
10175 ssh_pkt_addstring(s->pktout, "ssh-connection");
10176 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
10178 s->gss_buf.value = (char *)s->pktout->data + micoffset;
10179 s->gss_buf.length = s->pktout->length - micoffset;
10181 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
10182 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
10183 ssh_pkt_addstring_start(s->pktout);
10184 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
10185 ssh2_pkt_send(ssh, s->pktout);
10186 s->gsslib->free_mic(s->gsslib, &mic);
10190 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
10191 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
10194 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
10197 * Keyboard-interactive authentication.
10200 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
10202 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
10204 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10205 ssh2_pkt_addstring(s->pktout, ssh->username);
10206 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10207 /* service requested */
10208 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
10210 ssh2_pkt_addstring(s->pktout, ""); /* lang */
10211 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
10212 ssh2_pkt_send(ssh, s->pktout);
10214 logevent("Attempting keyboard-interactive authentication");
10216 crWaitUntilV(pktin);
10217 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
10218 /* Server is not willing to do keyboard-interactive
10219 * at all (or, bizarrely but legally, accepts the
10220 * user without actually issuing any prompts).
10221 * Give up on it entirely. */
10223 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
10224 s->kbd_inter_refused = TRUE; /* don't try it again */
10229 * Loop while the server continues to send INFO_REQUESTs.
10231 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
10233 char *name, *inst, *lang;
10234 int name_len, inst_len, lang_len;
10238 * We've got a fresh USERAUTH_INFO_REQUEST.
10239 * Get the preamble and start building a prompt.
10241 ssh_pkt_getstring(pktin, &name, &name_len);
10242 ssh_pkt_getstring(pktin, &inst, &inst_len);
10243 ssh_pkt_getstring(pktin, &lang, &lang_len);
10244 s->cur_prompt = new_prompts(ssh->frontend);
10245 s->cur_prompt->to_server = TRUE;
10248 * Get any prompt(s) from the packet.
10250 s->num_prompts = ssh_pkt_getuint32(pktin);
10251 for (i = 0; i < s->num_prompts; i++) {
10255 static char noprompt[] =
10256 "<server failed to send prompt>: ";
10258 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
10259 echo = ssh2_pkt_getbool(pktin);
10262 prompt_len = lenof(noprompt)-1;
10264 add_prompt(s->cur_prompt,
10265 dupprintf("%.*s", prompt_len, prompt),
10270 /* FIXME: better prefix to distinguish from
10271 * local prompts? */
10272 s->cur_prompt->name =
10273 dupprintf("SSH server: %.*s", name_len, name);
10274 s->cur_prompt->name_reqd = TRUE;
10276 s->cur_prompt->name =
10277 dupstr("SSH server authentication");
10278 s->cur_prompt->name_reqd = FALSE;
10280 /* We add a prefix to try to make it clear that a prompt
10281 * has come from the server.
10282 * FIXME: ugly to print "Using..." in prompt _every_
10283 * time round. Can this be done more subtly? */
10284 /* Special case: for reasons best known to themselves,
10285 * some servers send k-i requests with no prompts and
10286 * nothing to display. Keep quiet in this case. */
10287 if (s->num_prompts || name_len || inst_len) {
10288 s->cur_prompt->instruction =
10289 dupprintf("Using keyboard-interactive authentication.%s%.*s",
10290 inst_len ? "\n" : "", inst_len, inst);
10291 s->cur_prompt->instr_reqd = TRUE;
10293 s->cur_prompt->instr_reqd = FALSE;
10297 * Display any instructions, and get the user's
10301 int ret; /* not live over crReturn */
10302 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10305 crWaitUntilV(!pktin);
10306 ret = get_userpass_input(s->cur_prompt, in, inlen);
10311 * Failed to get responses. Terminate.
10313 free_prompts(s->cur_prompt);
10314 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10315 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10322 * Send the response(s) to the server.
10324 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
10325 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
10326 for (i=0; i < s->num_prompts; i++) {
10327 ssh2_pkt_addstring(s->pktout,
10328 s->cur_prompt->prompts[i]->result);
10330 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10333 * Free the prompts structure from this iteration.
10334 * If there's another, a new one will be allocated
10335 * when we return to the top of this while loop.
10337 free_prompts(s->cur_prompt);
10340 * Get the next packet in case it's another
10343 crWaitUntilV(pktin);
10348 * We should have SUCCESS or FAILURE now.
10352 } else if (s->can_passwd) {
10355 * Plain old password authentication.
10357 int ret; /* not live over crReturn */
10358 int changereq_first_time; /* not live over crReturn */
10360 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
10362 s->cur_prompt = new_prompts(ssh->frontend);
10363 s->cur_prompt->to_server = TRUE;
10364 s->cur_prompt->name = dupstr("SSH password");
10365 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
10370 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10373 crWaitUntilV(!pktin);
10374 ret = get_userpass_input(s->cur_prompt, in, inlen);
10379 * Failed to get responses. Terminate.
10381 free_prompts(s->cur_prompt);
10382 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10383 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10388 * Squirrel away the password. (We may need it later if
10389 * asked to change it.)
10391 s->password = dupstr(s->cur_prompt->prompts[0]->result);
10392 free_prompts(s->cur_prompt);
10395 * Send the password packet.
10397 * We pad out the password packet to 256 bytes to make
10398 * it harder for an attacker to find the length of the
10401 * Anyone using a password longer than 256 bytes
10402 * probably doesn't have much to worry about from
10403 * people who find out how long their password is!
10405 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10406 ssh2_pkt_addstring(s->pktout, ssh->username);
10407 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10408 /* service requested */
10409 ssh2_pkt_addstring(s->pktout, "password");
10410 ssh2_pkt_addbool(s->pktout, FALSE);
10411 ssh2_pkt_addstring(s->pktout, s->password);
10412 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10413 logevent("Sent password");
10414 s->type = AUTH_TYPE_PASSWORD;
10417 * Wait for next packet, in case it's a password change
10420 crWaitUntilV(pktin);
10421 changereq_first_time = TRUE;
10423 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
10426 * We're being asked for a new password
10427 * (perhaps not for the first time).
10428 * Loop until the server accepts it.
10431 int got_new = FALSE; /* not live over crReturn */
10432 char *prompt; /* not live over crReturn */
10433 int prompt_len; /* not live over crReturn */
10437 if (changereq_first_time)
10438 msg = "Server requested password change";
10440 msg = "Server rejected new password";
10442 c_write_str(ssh, msg);
10443 c_write_str(ssh, "\r\n");
10446 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
10448 s->cur_prompt = new_prompts(ssh->frontend);
10449 s->cur_prompt->to_server = TRUE;
10450 s->cur_prompt->name = dupstr("New SSH password");
10451 s->cur_prompt->instruction =
10452 dupprintf("%.*s", prompt_len, NULLTOEMPTY(prompt));
10453 s->cur_prompt->instr_reqd = TRUE;
10455 * There's no explicit requirement in the protocol
10456 * for the "old" passwords in the original and
10457 * password-change messages to be the same, and
10458 * apparently some Cisco kit supports password change
10459 * by the user entering a blank password originally
10460 * and the real password subsequently, so,
10461 * reluctantly, we prompt for the old password again.
10463 * (On the other hand, some servers don't even bother
10464 * to check this field.)
10466 add_prompt(s->cur_prompt,
10467 dupstr("Current password (blank for previously entered password): "),
10469 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
10471 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
10475 * Loop until the user manages to enter the same
10480 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10483 crWaitUntilV(!pktin);
10484 ret = get_userpass_input(s->cur_prompt, in, inlen);
10489 * Failed to get responses. Terminate.
10491 /* burn the evidence */
10492 free_prompts(s->cur_prompt);
10493 smemclr(s->password, strlen(s->password));
10494 sfree(s->password);
10495 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10496 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10502 * If the user specified a new original password
10503 * (IYSWIM), overwrite any previously specified
10505 * (A side effect is that the user doesn't have to
10506 * re-enter it if they louse up the new password.)
10508 if (s->cur_prompt->prompts[0]->result[0]) {
10509 smemclr(s->password, strlen(s->password));
10510 /* burn the evidence */
10511 sfree(s->password);
10513 dupstr(s->cur_prompt->prompts[0]->result);
10517 * Check the two new passwords match.
10519 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
10520 s->cur_prompt->prompts[2]->result)
10523 /* They don't. Silly user. */
10524 c_write_str(ssh, "Passwords do not match\r\n");
10529 * Send the new password (along with the old one).
10530 * (see above for padding rationale)
10532 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10533 ssh2_pkt_addstring(s->pktout, ssh->username);
10534 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10535 /* service requested */
10536 ssh2_pkt_addstring(s->pktout, "password");
10537 ssh2_pkt_addbool(s->pktout, TRUE);
10538 ssh2_pkt_addstring(s->pktout, s->password);
10539 ssh2_pkt_addstring(s->pktout,
10540 s->cur_prompt->prompts[1]->result);
10541 free_prompts(s->cur_prompt);
10542 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10543 logevent("Sent new password");
10546 * Now see what the server has to say about it.
10547 * (If it's CHANGEREQ again, it's not happy with the
10550 crWaitUntilV(pktin);
10551 changereq_first_time = FALSE;
10556 * We need to reexamine the current pktin at the top
10557 * of the loop. Either:
10558 * - we weren't asked to change password at all, in
10559 * which case it's a SUCCESS or FAILURE with the
10561 * - we sent a new password, and the server was
10562 * either OK with it (SUCCESS or FAILURE w/partial
10563 * success) or unhappy with the _old_ password
10564 * (FAILURE w/o partial success)
10565 * In any of these cases, we go back to the top of
10566 * the loop and start again.
10571 * We don't need the old password any more, in any
10572 * case. Burn the evidence.
10574 smemclr(s->password, strlen(s->password));
10575 sfree(s->password);
10578 char *str = dupprintf("No supported authentication methods available"
10579 " (server sent: %.*s)",
10582 ssh_disconnect(ssh, str,
10583 "No supported authentication methods available",
10584 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
10594 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
10596 /* Clear up various bits and pieces from authentication. */
10597 if (s->publickey_blob) {
10598 sfree(s->publickey_algorithm);
10599 sfree(s->publickey_blob);
10600 sfree(s->publickey_comment);
10602 if (s->agent_response)
10603 sfree(s->agent_response);
10605 if (s->userauth_success && !ssh->bare_connection) {
10607 * We've just received USERAUTH_SUCCESS, and we haven't sent any
10608 * packets since. Signal the transport layer to consider enacting
10609 * delayed compression.
10611 * (Relying on we_are_in is not sufficient, as
10612 * draft-miller-secsh-compression-delayed is quite clear that it
10613 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
10614 * become set for other reasons.)
10616 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
10619 ssh->channels = newtree234(ssh_channelcmp);
10622 * Set up handlers for some connection protocol messages, so we
10623 * don't have to handle them repeatedly in this coroutine.
10625 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
10626 ssh2_msg_channel_window_adjust;
10627 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
10628 ssh2_msg_global_request;
10631 * Create the main session channel.
10633 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
10634 ssh->mainchan = NULL;
10636 ssh->mainchan = snew(struct ssh_channel);
10637 ssh->mainchan->ssh = ssh;
10638 ssh2_channel_init(ssh->mainchan);
10640 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
10642 * Just start a direct-tcpip channel and use it as the main
10645 ssh_send_port_open(ssh->mainchan,
10646 conf_get_str(ssh->conf, CONF_ssh_nc_host),
10647 conf_get_int(ssh->conf, CONF_ssh_nc_port),
10649 ssh->ncmode = TRUE;
10651 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
10652 logevent("Opening session as main channel");
10653 ssh2_pkt_send(ssh, s->pktout);
10654 ssh->ncmode = FALSE;
10656 crWaitUntilV(pktin);
10657 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
10658 bombout(("Server refused to open channel"));
10660 /* FIXME: error data comes back in FAILURE packet */
10662 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
10663 bombout(("Server's channel confirmation cited wrong channel"));
10666 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
10667 ssh->mainchan->halfopen = FALSE;
10668 ssh->mainchan->type = CHAN_MAINSESSION;
10669 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
10670 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
10671 add234(ssh->channels, ssh->mainchan);
10672 update_specials_menu(ssh->frontend);
10673 logevent("Opened main channel");
10677 * Now we have a channel, make dispatch table entries for
10678 * general channel-based messages.
10680 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
10681 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
10682 ssh2_msg_channel_data;
10683 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
10684 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
10685 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
10686 ssh2_msg_channel_open_confirmation;
10687 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
10688 ssh2_msg_channel_open_failure;
10689 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
10690 ssh2_msg_channel_request;
10691 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
10692 ssh2_msg_channel_open;
10693 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
10694 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
10697 * Now the connection protocol is properly up and running, with
10698 * all those dispatch table entries, so it's safe to let
10699 * downstreams start trying to open extra channels through us.
10701 if (ssh->connshare)
10702 share_activate(ssh->connshare, ssh->v_s);
10704 if (ssh->mainchan && ssh_is_simple(ssh)) {
10706 * This message indicates to the server that we promise
10707 * not to try to run any other channel in parallel with
10708 * this one, so it's safe for it to advertise a very large
10709 * window and leave the flow control to TCP.
10711 s->pktout = ssh2_chanreq_init(ssh->mainchan,
10712 "simple@putty.projects.tartarus.org",
10714 ssh2_pkt_send(ssh, s->pktout);
10718 * Enable port forwardings.
10720 ssh_setup_portfwd(ssh, ssh->conf);
10722 if (ssh->mainchan && !ssh->ncmode) {
10724 * Send the CHANNEL_REQUESTS for the main session channel.
10725 * Each one is handled by its own little asynchronous
10729 /* Potentially enable X11 forwarding. */
10730 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
10732 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
10734 if (!ssh->x11disp) {
10735 /* FIXME: return an error message from x11_setup_display */
10736 logevent("X11 forwarding not enabled: unable to"
10737 " initialise X display");
10739 ssh->x11auth = x11_invent_fake_auth
10740 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
10741 ssh->x11auth->disp = ssh->x11disp;
10743 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
10747 /* Potentially enable agent forwarding. */
10748 if (ssh_agent_forwarding_permitted(ssh))
10749 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
10751 /* Now allocate a pty for the session. */
10752 if (!conf_get_int(ssh->conf, CONF_nopty))
10753 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
10755 /* Send environment variables. */
10756 ssh2_setup_env(ssh->mainchan, NULL, NULL);
10759 * Start a shell or a remote command. We may have to attempt
10760 * this twice if the config data has provided a second choice
10767 if (ssh->fallback_cmd) {
10768 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
10769 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
10771 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
10772 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
10776 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
10777 ssh2_response_authconn, NULL);
10778 ssh2_pkt_addstring(s->pktout, cmd);
10780 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
10781 ssh2_response_authconn, NULL);
10782 ssh2_pkt_addstring(s->pktout, cmd);
10784 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
10785 ssh2_response_authconn, NULL);
10787 ssh2_pkt_send(ssh, s->pktout);
10789 crWaitUntilV(pktin);
10791 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
10792 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
10793 bombout(("Unexpected response to shell/command request:"
10794 " packet type %d", pktin->type));
10798 * We failed to start the command. If this is the
10799 * fallback command, we really are finished; if it's
10800 * not, and if the fallback command exists, try falling
10801 * back to it before complaining.
10803 if (!ssh->fallback_cmd &&
10804 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
10805 logevent("Primary command failed; attempting fallback");
10806 ssh->fallback_cmd = TRUE;
10809 bombout(("Server refused to start a shell/command"));
10812 logevent("Started a shell/command");
10817 ssh->editing = ssh->echoing = TRUE;
10820 ssh->state = SSH_STATE_SESSION;
10821 if (ssh->size_needed)
10822 ssh_size(ssh, ssh->term_width, ssh->term_height);
10823 if (ssh->eof_needed)
10824 ssh_special(ssh, TS_EOF);
10830 ldisc_echoedit_update(ssh->ldisc); /* cause ldisc to notice changes */
10838 * _All_ the connection-layer packets we expect to
10839 * receive are now handled by the dispatch table.
10840 * Anything that reaches here must be bogus.
10843 bombout(("Strange packet received: type %d", pktin->type));
10845 } else if (ssh->mainchan) {
10847 * We have spare data. Add it to the channel buffer.
10849 ssh_send_channel_data(ssh->mainchan, (char *)in, inlen);
10857 * Handlers for SSH-2 messages that might arrive at any moment.
10859 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
10861 /* log reason code in disconnect message */
10863 int reason, msglen;
10865 reason = ssh_pkt_getuint32(pktin);
10866 ssh_pkt_getstring(pktin, &msg, &msglen);
10868 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
10869 buf = dupprintf("Received disconnect message (%s)",
10870 ssh2_disconnect_reasons[reason]);
10872 buf = dupprintf("Received disconnect message (unknown"
10873 " type %d)", reason);
10877 buf = dupprintf("Disconnection message text: %.*s",
10878 msglen, NULLTOEMPTY(msg));
10880 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
10882 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
10883 ssh2_disconnect_reasons[reason] : "unknown",
10884 msglen, NULLTOEMPTY(msg)));
10888 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
10890 /* log the debug message */
10894 /* XXX maybe we should actually take notice of the return value */
10895 ssh2_pkt_getbool(pktin);
10896 ssh_pkt_getstring(pktin, &msg, &msglen);
10898 logeventf(ssh, "Remote debug message: %.*s", msglen, NULLTOEMPTY(msg));
10901 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
10903 do_ssh2_transport(ssh, NULL, 0, pktin);
10907 * Called if we receive a packet that isn't allowed by the protocol.
10908 * This only applies to packets whose meaning PuTTY understands.
10909 * Entirely unknown packets are handled below.
10911 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
10913 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
10914 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
10916 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
10920 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
10922 struct Packet *pktout;
10923 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
10924 ssh2_pkt_adduint32(pktout, pktin->sequence);
10926 * UNIMPLEMENTED messages MUST appear in the same order as the
10927 * messages they respond to. Hence, never queue them.
10929 ssh2_pkt_send_noqueue(ssh, pktout);
10933 * Handle the top-level SSH-2 protocol.
10935 static void ssh2_protocol_setup(Ssh ssh)
10940 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10942 for (i = 0; i < 256; i++)
10943 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10946 * Initially, we only accept transport messages (and a few generic
10947 * ones). do_ssh2_authconn will add more when it starts.
10948 * Messages that are understood but not currently acceptable go to
10949 * ssh2_msg_unexpected.
10951 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10952 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
10953 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
10954 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
10955 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
10956 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
10957 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
10958 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
10959 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
10960 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
10961 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
10962 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
10963 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
10964 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
10965 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
10966 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
10967 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
10968 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
10969 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
10970 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10971 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10972 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10973 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10974 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10975 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10976 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10977 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10978 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10979 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10980 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10981 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10982 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10983 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10986 * These messages have a special handler from the start.
10988 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10989 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
10990 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10993 static void ssh2_bare_connection_protocol_setup(Ssh ssh)
10998 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
11000 for (i = 0; i < 256; i++)
11001 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
11004 * Initially, we set all ssh-connection messages to 'unexpected';
11005 * do_ssh2_authconn will fill things in properly. We also handle a
11006 * couple of messages from the transport protocol which aren't
11007 * related to key exchange (UNIMPLEMENTED, IGNORE, DEBUG,
11010 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
11011 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
11012 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
11013 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
11014 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
11015 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
11016 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
11017 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
11018 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
11019 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
11020 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
11021 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
11022 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
11023 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
11025 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
11028 * These messages have a special handler from the start.
11030 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
11031 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore;
11032 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
11035 static void ssh2_timer(void *ctx, unsigned long now)
11037 Ssh ssh = (Ssh)ctx;
11039 if (ssh->state == SSH_STATE_CLOSED)
11042 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11043 conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
11044 now == ssh->next_rekey) {
11045 do_ssh2_transport(ssh, "timeout", -1, NULL);
11049 static void ssh2_protocol(Ssh ssh, const void *vin, int inlen,
11050 struct Packet *pktin)
11052 const unsigned char *in = (const unsigned char *)vin;
11053 if (ssh->state == SSH_STATE_CLOSED)
11057 ssh->incoming_data_size += pktin->encrypted_len;
11058 if (!ssh->kex_in_progress &&
11059 ssh->max_data_size != 0 &&
11060 ssh->incoming_data_size > ssh->max_data_size)
11061 do_ssh2_transport(ssh, "too much data received", -1, NULL);
11065 ssh->packet_dispatch[pktin->type](ssh, pktin);
11066 else if (!ssh->protocol_initial_phase_done)
11067 do_ssh2_transport(ssh, in, inlen, pktin);
11069 do_ssh2_authconn(ssh, in, inlen, pktin);
11072 static void ssh2_bare_connection_protocol(Ssh ssh, const void *vin, int inlen,
11073 struct Packet *pktin)
11075 const unsigned char *in = (const unsigned char *)vin;
11076 if (ssh->state == SSH_STATE_CLOSED)
11080 ssh->packet_dispatch[pktin->type](ssh, pktin);
11082 do_ssh2_authconn(ssh, in, inlen, pktin);
11085 static void ssh_cache_conf_values(Ssh ssh)
11087 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
11091 * Called to set up the connection.
11093 * Returns an error message, or NULL on success.
11095 static const char *ssh_init(void *frontend_handle, void **backend_handle,
11097 const char *host, int port, char **realhost,
11098 int nodelay, int keepalive)
11103 ssh = snew(struct ssh_tag);
11104 ssh->conf = conf_copy(conf);
11105 ssh_cache_conf_values(ssh);
11106 ssh->version = 0; /* when not ready yet */
11108 ssh->cipher = NULL;
11109 ssh->v1_cipher_ctx = NULL;
11110 ssh->crcda_ctx = NULL;
11111 ssh->cscipher = NULL;
11112 ssh->cs_cipher_ctx = NULL;
11113 ssh->sccipher = NULL;
11114 ssh->sc_cipher_ctx = NULL;
11116 ssh->cs_mac_ctx = NULL;
11118 ssh->sc_mac_ctx = NULL;
11119 ssh->cscomp = NULL;
11120 ssh->cs_comp_ctx = NULL;
11121 ssh->sccomp = NULL;
11122 ssh->sc_comp_ctx = NULL;
11124 ssh->kex_ctx = NULL;
11125 ssh->hostkey = NULL;
11126 ssh->hostkey_str = NULL;
11127 ssh->exitcode = -1;
11128 ssh->close_expected = FALSE;
11129 ssh->clean_exit = FALSE;
11130 ssh->state = SSH_STATE_PREPACKET;
11131 ssh->size_needed = FALSE;
11132 ssh->eof_needed = FALSE;
11134 ssh->logctx = NULL;
11135 ssh->deferred_send_data = NULL;
11136 ssh->deferred_len = 0;
11137 ssh->deferred_size = 0;
11138 ssh->fallback_cmd = 0;
11139 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
11140 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
11141 ssh->x11disp = NULL;
11142 ssh->x11auth = NULL;
11143 ssh->x11authtree = newtree234(x11_authcmp);
11144 ssh->v1_compressing = FALSE;
11145 ssh->v2_outgoing_sequence = 0;
11146 ssh->ssh1_rdpkt_crstate = 0;
11147 ssh->ssh2_rdpkt_crstate = 0;
11148 ssh->ssh2_bare_rdpkt_crstate = 0;
11149 ssh->ssh_gotdata_crstate = 0;
11150 ssh->do_ssh1_connection_crstate = 0;
11151 ssh->do_ssh_init_state = NULL;
11152 ssh->do_ssh_connection_init_state = NULL;
11153 ssh->do_ssh1_login_state = NULL;
11154 ssh->do_ssh2_transport_state = NULL;
11155 ssh->do_ssh2_authconn_state = NULL;
11158 ssh->mainchan = NULL;
11159 ssh->throttled_all = 0;
11160 ssh->v1_stdout_throttling = 0;
11162 ssh->queuelen = ssh->queuesize = 0;
11163 ssh->queueing = FALSE;
11164 ssh->qhead = ssh->qtail = NULL;
11165 ssh->deferred_rekey_reason = NULL;
11166 bufchain_init(&ssh->queued_incoming_data);
11167 ssh->frozen = FALSE;
11168 ssh->username = NULL;
11169 ssh->sent_console_eof = FALSE;
11170 ssh->got_pty = FALSE;
11171 ssh->bare_connection = FALSE;
11172 ssh->X11_fwd_enabled = FALSE;
11173 ssh->connshare = NULL;
11174 ssh->attempting_connshare = FALSE;
11175 ssh->session_started = FALSE;
11176 ssh->specials = NULL;
11177 ssh->n_uncert_hostkeys = 0;
11178 ssh->cross_certifying = FALSE;
11180 *backend_handle = ssh;
11183 if (crypto_startup() == 0)
11184 return "Microsoft high encryption pack not installed!";
11187 ssh->frontend = frontend_handle;
11188 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
11189 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
11191 ssh->channels = NULL;
11192 ssh->rportfwds = NULL;
11193 ssh->portfwds = NULL;
11198 ssh->conn_throttle_count = 0;
11199 ssh->overall_bufsize = 0;
11200 ssh->fallback_cmd = 0;
11202 ssh->protocol = NULL;
11204 ssh->protocol_initial_phase_done = FALSE;
11206 ssh->pinger = NULL;
11208 ssh->incoming_data_size = ssh->outgoing_data_size =
11209 ssh->deferred_data_size = 0L;
11210 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
11211 CONF_ssh_rekey_data));
11212 ssh->kex_in_progress = FALSE;
11215 ssh->gsslibs = NULL;
11218 random_ref(); /* do this now - may be needed by sharing setup code */
11220 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
11229 static void ssh_free(void *handle)
11231 Ssh ssh = (Ssh) handle;
11232 struct ssh_channel *c;
11233 struct ssh_rportfwd *pf;
11234 struct X11FakeAuth *auth;
11236 if (ssh->v1_cipher_ctx)
11237 ssh->cipher->free_context(ssh->v1_cipher_ctx);
11238 if (ssh->cs_cipher_ctx)
11239 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
11240 if (ssh->sc_cipher_ctx)
11241 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
11242 if (ssh->cs_mac_ctx)
11243 ssh->csmac->free_context(ssh->cs_mac_ctx);
11244 if (ssh->sc_mac_ctx)
11245 ssh->scmac->free_context(ssh->sc_mac_ctx);
11246 if (ssh->cs_comp_ctx) {
11248 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
11250 zlib_compress_cleanup(ssh->cs_comp_ctx);
11252 if (ssh->sc_comp_ctx) {
11254 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
11256 zlib_decompress_cleanup(ssh->sc_comp_ctx);
11259 dh_cleanup(ssh->kex_ctx);
11260 sfree(ssh->savedhost);
11262 while (ssh->queuelen-- > 0)
11263 ssh_free_packet(ssh->queue[ssh->queuelen]);
11266 while (ssh->qhead) {
11267 struct queued_handler *qh = ssh->qhead;
11268 ssh->qhead = qh->next;
11271 ssh->qhead = ssh->qtail = NULL;
11273 if (ssh->channels) {
11274 while ((c = delpos234(ssh->channels, 0)) != NULL) {
11277 if (c->u.x11.xconn != NULL)
11278 x11_close(c->u.x11.xconn);
11280 case CHAN_SOCKDATA:
11281 case CHAN_SOCKDATA_DORMANT:
11282 if (c->u.pfd.pf != NULL)
11283 pfd_close(c->u.pfd.pf);
11286 if (ssh->version == 2) {
11287 struct outstanding_channel_request *ocr, *nocr;
11288 ocr = c->v.v2.chanreq_head;
11290 ocr->handler(c, NULL, ocr->ctx);
11295 bufchain_clear(&c->v.v2.outbuffer);
11299 freetree234(ssh->channels);
11300 ssh->channels = NULL;
11303 if (ssh->connshare)
11304 sharestate_free(ssh->connshare);
11306 if (ssh->rportfwds) {
11307 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
11309 freetree234(ssh->rportfwds);
11310 ssh->rportfwds = NULL;
11312 sfree(ssh->deferred_send_data);
11314 x11_free_display(ssh->x11disp);
11315 while ((auth = delpos234(ssh->x11authtree, 0)) != NULL)
11316 x11_free_fake_auth(auth);
11317 freetree234(ssh->x11authtree);
11318 sfree(ssh->do_ssh_init_state);
11319 sfree(ssh->do_ssh1_login_state);
11320 sfree(ssh->do_ssh2_transport_state);
11321 sfree(ssh->do_ssh2_authconn_state);
11324 sfree(ssh->fullhostname);
11325 sfree(ssh->hostkey_str);
11326 sfree(ssh->specials);
11327 if (ssh->crcda_ctx) {
11328 crcda_free_context(ssh->crcda_ctx);
11329 ssh->crcda_ctx = NULL;
11332 ssh_do_close(ssh, TRUE);
11333 expire_timer_context(ssh);
11335 pinger_free(ssh->pinger);
11336 bufchain_clear(&ssh->queued_incoming_data);
11337 sfree(ssh->username);
11338 conf_free(ssh->conf);
11341 ssh_gss_cleanup(ssh->gsslibs);
11349 * Reconfigure the SSH backend.
11351 static void ssh_reconfig(void *handle, Conf *conf)
11353 Ssh ssh = (Ssh) handle;
11354 const char *rekeying = NULL;
11355 int rekey_mandatory = FALSE;
11356 unsigned long old_max_data_size;
11359 pinger_reconfig(ssh->pinger, ssh->conf, conf);
11361 ssh_setup_portfwd(ssh, conf);
11363 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
11364 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
11366 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
11367 unsigned long now = GETTICKCOUNT();
11369 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
11370 rekeying = "timeout shortened";
11372 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
11376 old_max_data_size = ssh->max_data_size;
11377 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
11378 CONF_ssh_rekey_data));
11379 if (old_max_data_size != ssh->max_data_size &&
11380 ssh->max_data_size != 0) {
11381 if (ssh->outgoing_data_size > ssh->max_data_size ||
11382 ssh->incoming_data_size > ssh->max_data_size)
11383 rekeying = "data limit lowered";
11386 if (conf_get_int(ssh->conf, CONF_compression) !=
11387 conf_get_int(conf, CONF_compression)) {
11388 rekeying = "compression setting changed";
11389 rekey_mandatory = TRUE;
11392 for (i = 0; i < CIPHER_MAX; i++)
11393 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
11394 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
11395 rekeying = "cipher settings changed";
11396 rekey_mandatory = TRUE;
11398 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
11399 conf_get_int(conf, CONF_ssh2_des_cbc)) {
11400 rekeying = "cipher settings changed";
11401 rekey_mandatory = TRUE;
11404 conf_free(ssh->conf);
11405 ssh->conf = conf_copy(conf);
11406 ssh_cache_conf_values(ssh);
11408 if (!ssh->bare_connection && rekeying) {
11409 if (!ssh->kex_in_progress) {
11410 do_ssh2_transport(ssh, rekeying, -1, NULL);
11411 } else if (rekey_mandatory) {
11412 ssh->deferred_rekey_reason = rekeying;
11418 * Called to send data down the SSH connection.
11420 static int ssh_send(void *handle, const char *buf, int len)
11422 Ssh ssh = (Ssh) handle;
11424 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
11427 ssh->protocol(ssh, (const unsigned char *)buf, len, 0);
11429 return ssh_sendbuffer(ssh);
11433 * Called to query the current amount of buffered stdin data.
11435 static int ssh_sendbuffer(void *handle)
11437 Ssh ssh = (Ssh) handle;
11438 int override_value;
11440 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
11444 * If the SSH socket itself has backed up, add the total backup
11445 * size on that to any individual buffer on the stdin channel.
11447 override_value = 0;
11448 if (ssh->throttled_all)
11449 override_value = ssh->overall_bufsize;
11451 if (ssh->version == 1) {
11452 return override_value;
11453 } else if (ssh->version == 2) {
11454 if (!ssh->mainchan)
11455 return override_value;
11457 return (override_value +
11458 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
11465 * Called to set the size of the window from SSH's POV.
11467 static void ssh_size(void *handle, int width, int height)
11469 Ssh ssh = (Ssh) handle;
11470 struct Packet *pktout;
11472 ssh->term_width = width;
11473 ssh->term_height = height;
11475 switch (ssh->state) {
11476 case SSH_STATE_BEFORE_SIZE:
11477 case SSH_STATE_PREPACKET:
11478 case SSH_STATE_CLOSED:
11479 break; /* do nothing */
11480 case SSH_STATE_INTERMED:
11481 ssh->size_needed = TRUE; /* buffer for later */
11483 case SSH_STATE_SESSION:
11484 if (!conf_get_int(ssh->conf, CONF_nopty)) {
11485 if (ssh->version == 1) {
11486 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
11487 PKT_INT, ssh->term_height,
11488 PKT_INT, ssh->term_width,
11489 PKT_INT, 0, PKT_INT, 0, PKT_END);
11490 } else if (ssh->mainchan) {
11491 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
11493 ssh2_pkt_adduint32(pktout, ssh->term_width);
11494 ssh2_pkt_adduint32(pktout, ssh->term_height);
11495 ssh2_pkt_adduint32(pktout, 0);
11496 ssh2_pkt_adduint32(pktout, 0);
11497 ssh2_pkt_send(ssh, pktout);
11505 * Return a list of the special codes that make sense in this
11508 static const struct telnet_special *ssh_get_specials(void *handle)
11510 static const struct telnet_special ssh1_ignore_special[] = {
11511 {"IGNORE message", TS_NOP}
11513 static const struct telnet_special ssh2_ignore_special[] = {
11514 {"IGNORE message", TS_NOP},
11516 static const struct telnet_special ssh2_rekey_special[] = {
11517 {"Repeat key exchange", TS_REKEY},
11519 static const struct telnet_special ssh2_session_specials[] = {
11522 /* These are the signal names defined by RFC 4254.
11523 * They include all the ISO C signals, but are a subset of the POSIX
11524 * required signals. */
11525 {"SIGINT (Interrupt)", TS_SIGINT},
11526 {"SIGTERM (Terminate)", TS_SIGTERM},
11527 {"SIGKILL (Kill)", TS_SIGKILL},
11528 {"SIGQUIT (Quit)", TS_SIGQUIT},
11529 {"SIGHUP (Hangup)", TS_SIGHUP},
11530 {"More signals", TS_SUBMENU},
11531 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
11532 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
11533 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
11534 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
11535 {NULL, TS_EXITMENU}
11537 static const struct telnet_special specials_end[] = {
11538 {NULL, TS_EXITMENU}
11541 struct telnet_special *specials = NULL;
11542 int nspecials = 0, specialsize = 0;
11544 Ssh ssh = (Ssh) handle;
11546 sfree(ssh->specials);
11548 #define ADD_SPECIALS(name) do \
11550 int len = lenof(name); \
11551 if (nspecials + len > specialsize) { \
11552 specialsize = (nspecials + len) * 5 / 4 + 32; \
11553 specials = sresize(specials, specialsize, struct telnet_special); \
11555 memcpy(specials+nspecials, name, len*sizeof(struct telnet_special)); \
11556 nspecials += len; \
11559 if (ssh->version == 1) {
11560 /* Don't bother offering IGNORE if we've decided the remote
11561 * won't cope with it, since we wouldn't bother sending it if
11563 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11564 ADD_SPECIALS(ssh1_ignore_special);
11565 } else if (ssh->version == 2) {
11566 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
11567 ADD_SPECIALS(ssh2_ignore_special);
11568 if (!(ssh->remote_bugs & BUG_SSH2_REKEY) && !ssh->bare_connection)
11569 ADD_SPECIALS(ssh2_rekey_special);
11571 ADD_SPECIALS(ssh2_session_specials);
11573 if (ssh->n_uncert_hostkeys) {
11574 static const struct telnet_special uncert_start[] = {
11576 {"Cache new host key type", TS_SUBMENU},
11578 static const struct telnet_special uncert_end[] = {
11579 {NULL, TS_EXITMENU},
11583 ADD_SPECIALS(uncert_start);
11584 for (i = 0; i < ssh->n_uncert_hostkeys; i++) {
11585 struct telnet_special uncert[1];
11586 const struct ssh_signkey *alg =
11587 hostkey_algs[ssh->uncert_hostkeys[i]].alg;
11588 uncert[0].name = alg->name;
11589 uncert[0].code = TS_LOCALSTART + ssh->uncert_hostkeys[i];
11590 ADD_SPECIALS(uncert);
11592 ADD_SPECIALS(uncert_end);
11594 } /* else we're not ready yet */
11597 ADD_SPECIALS(specials_end);
11599 ssh->specials = specials;
11606 #undef ADD_SPECIALS
11610 * Send special codes. TS_EOF is useful for `plink', so you
11611 * can send an EOF and collect resulting output (e.g. `plink
11614 static void ssh_special(void *handle, Telnet_Special code)
11616 Ssh ssh = (Ssh) handle;
11617 struct Packet *pktout;
11619 if (code == TS_EOF) {
11620 if (ssh->state != SSH_STATE_SESSION) {
11622 * Buffer the EOF in case we are pre-SESSION, so we can
11623 * send it as soon as we reach SESSION.
11625 if (code == TS_EOF)
11626 ssh->eof_needed = TRUE;
11629 if (ssh->version == 1) {
11630 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
11631 } else if (ssh->mainchan) {
11632 sshfwd_write_eof(ssh->mainchan);
11633 ssh->send_ok = 0; /* now stop trying to read from stdin */
11635 logevent("Sent EOF message");
11636 } else if (code == TS_PING || code == TS_NOP) {
11637 if (ssh->state == SSH_STATE_CLOSED
11638 || ssh->state == SSH_STATE_PREPACKET) return;
11639 if (ssh->version == 1) {
11640 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11641 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
11643 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
11644 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
11645 ssh2_pkt_addstring_start(pktout);
11646 ssh2_pkt_send_noqueue(ssh, pktout);
11649 } else if (code == TS_REKEY) {
11650 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11651 ssh->version == 2) {
11652 do_ssh2_transport(ssh, "at user request", -1, NULL);
11654 } else if (code >= TS_LOCALSTART) {
11655 ssh->hostkey = hostkey_algs[code - TS_LOCALSTART].alg;
11656 ssh->cross_certifying = TRUE;
11657 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11658 ssh->version == 2) {
11659 do_ssh2_transport(ssh, "cross-certifying new host key", -1, NULL);
11661 } else if (code == TS_BRK) {
11662 if (ssh->state == SSH_STATE_CLOSED
11663 || ssh->state == SSH_STATE_PREPACKET) return;
11664 if (ssh->version == 1) {
11665 logevent("Unable to send BREAK signal in SSH-1");
11666 } else if (ssh->mainchan) {
11667 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
11668 ssh2_pkt_adduint32(pktout, 0); /* default break length */
11669 ssh2_pkt_send(ssh, pktout);
11672 /* Is is a POSIX signal? */
11673 const char *signame = NULL;
11674 if (code == TS_SIGABRT) signame = "ABRT";
11675 if (code == TS_SIGALRM) signame = "ALRM";
11676 if (code == TS_SIGFPE) signame = "FPE";
11677 if (code == TS_SIGHUP) signame = "HUP";
11678 if (code == TS_SIGILL) signame = "ILL";
11679 if (code == TS_SIGINT) signame = "INT";
11680 if (code == TS_SIGKILL) signame = "KILL";
11681 if (code == TS_SIGPIPE) signame = "PIPE";
11682 if (code == TS_SIGQUIT) signame = "QUIT";
11683 if (code == TS_SIGSEGV) signame = "SEGV";
11684 if (code == TS_SIGTERM) signame = "TERM";
11685 if (code == TS_SIGUSR1) signame = "USR1";
11686 if (code == TS_SIGUSR2) signame = "USR2";
11687 /* The SSH-2 protocol does in principle support arbitrary named
11688 * signals, including signame@domain, but we don't support those. */
11690 /* It's a signal. */
11691 if (ssh->version == 2 && ssh->mainchan) {
11692 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
11693 ssh2_pkt_addstring(pktout, signame);
11694 ssh2_pkt_send(ssh, pktout);
11695 logeventf(ssh, "Sent signal SIG%s", signame);
11698 /* Never heard of it. Do nothing */
11703 void *new_sock_channel(void *handle, struct PortForwarding *pf)
11705 Ssh ssh = (Ssh) handle;
11706 struct ssh_channel *c;
11707 c = snew(struct ssh_channel);
11710 ssh2_channel_init(c);
11711 c->halfopen = TRUE;
11712 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
11714 add234(ssh->channels, c);
11718 unsigned ssh_alloc_sharing_channel(Ssh ssh, void *sharing_ctx)
11720 struct ssh_channel *c;
11721 c = snew(struct ssh_channel);
11724 ssh2_channel_init(c);
11725 c->type = CHAN_SHARING;
11726 c->u.sharing.ctx = sharing_ctx;
11727 add234(ssh->channels, c);
11731 void ssh_delete_sharing_channel(Ssh ssh, unsigned localid)
11733 struct ssh_channel *c;
11735 c = find234(ssh->channels, &localid, ssh_channelfind);
11737 ssh_channel_destroy(c);
11740 void ssh_send_packet_from_downstream(Ssh ssh, unsigned id, int type,
11741 const void *data, int datalen,
11742 const char *additional_log_text)
11744 struct Packet *pkt;
11746 pkt = ssh2_pkt_init(type);
11747 pkt->downstream_id = id;
11748 pkt->additional_log_text = additional_log_text;
11749 ssh2_pkt_adddata(pkt, data, datalen);
11750 ssh2_pkt_send(ssh, pkt);
11754 * This is called when stdout/stderr (the entity to which
11755 * from_backend sends data) manages to clear some backlog.
11757 static void ssh_unthrottle(void *handle, int bufsize)
11759 Ssh ssh = (Ssh) handle;
11762 if (ssh->version == 1) {
11763 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
11764 ssh->v1_stdout_throttling = 0;
11765 ssh_throttle_conn(ssh, -1);
11768 if (ssh->mainchan) {
11769 ssh2_set_window(ssh->mainchan,
11770 bufsize < ssh->mainchan->v.v2.locmaxwin ?
11771 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
11772 if (ssh_is_simple(ssh))
11775 buflimit = ssh->mainchan->v.v2.locmaxwin;
11776 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
11777 ssh->mainchan->throttling_conn = 0;
11778 ssh_throttle_conn(ssh, -1);
11784 * Now process any SSH connection data that was stashed in our
11785 * queue while we were frozen.
11787 ssh_process_queued_incoming_data(ssh);
11790 void ssh_send_port_open(void *channel, const char *hostname, int port,
11793 struct ssh_channel *c = (struct ssh_channel *)channel;
11795 struct Packet *pktout;
11797 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
11799 if (ssh->version == 1) {
11800 send_packet(ssh, SSH1_MSG_PORT_OPEN,
11801 PKT_INT, c->localid,
11804 /* PKT_STR, <org:orgport>, */
11807 pktout = ssh2_chanopen_init(c, "direct-tcpip");
11809 char *trimmed_host = host_strduptrim(hostname);
11810 ssh2_pkt_addstring(pktout, trimmed_host);
11811 sfree(trimmed_host);
11813 ssh2_pkt_adduint32(pktout, port);
11815 * We make up values for the originator data; partly it's
11816 * too much hassle to keep track, and partly I'm not
11817 * convinced the server should be told details like that
11818 * about my local network configuration.
11819 * The "originator IP address" is syntactically a numeric
11820 * IP address, and some servers (e.g., Tectia) get upset
11821 * if it doesn't match this syntax.
11823 ssh2_pkt_addstring(pktout, "0.0.0.0");
11824 ssh2_pkt_adduint32(pktout, 0);
11825 ssh2_pkt_send(ssh, pktout);
11829 static int ssh_connected(void *handle)
11831 Ssh ssh = (Ssh) handle;
11832 return ssh->s != NULL;
11835 static int ssh_sendok(void *handle)
11837 Ssh ssh = (Ssh) handle;
11838 return ssh->send_ok;
11841 static int ssh_ldisc(void *handle, int option)
11843 Ssh ssh = (Ssh) handle;
11844 if (option == LD_ECHO)
11845 return ssh->echoing;
11846 if (option == LD_EDIT)
11847 return ssh->editing;
11851 static void ssh_provide_ldisc(void *handle, void *ldisc)
11853 Ssh ssh = (Ssh) handle;
11854 ssh->ldisc = ldisc;
11857 static void ssh_provide_logctx(void *handle, void *logctx)
11859 Ssh ssh = (Ssh) handle;
11860 ssh->logctx = logctx;
11863 static int ssh_return_exitcode(void *handle)
11865 Ssh ssh = (Ssh) handle;
11866 if (ssh->s != NULL)
11869 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
11873 * cfg_info for SSH is the protocol running in this session.
11874 * (1 or 2 for the full SSH-1 or SSH-2 protocol; -1 for the bare
11875 * SSH-2 connection protocol, i.e. a downstream; 0 for not-decided-yet.)
11877 static int ssh_cfg_info(void *handle)
11879 Ssh ssh = (Ssh) handle;
11880 if (ssh->version == 0)
11881 return 0; /* don't know yet */
11882 else if (ssh->bare_connection)
11885 return ssh->version;
11889 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
11890 * that fails. This variable is the means by which scp.c can reach
11891 * into the SSH code and find out which one it got.
11893 extern int ssh_fallback_cmd(void *handle)
11895 Ssh ssh = (Ssh) handle;
11896 return ssh->fallback_cmd;
11899 Backend ssh_backend = {
11909 ssh_return_exitcode,
11913 ssh_provide_logctx,
11916 ssh_test_for_upstream,