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 maximum 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 void ssh2_add_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 && !s->proto1) {
3142 bombout(("SSH protocol version 1 required by configuration but "
3143 "not provided by server"));
3146 if (conf_get_int(ssh->conf, CONF_sshprot) == 3 && !s->proto2) {
3147 bombout(("SSH protocol version 2 required by configuration but "
3148 "not provided by server"));
3152 if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1))
3157 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
3159 /* Send the version string, if we haven't already */
3160 if (conf_get_int(ssh->conf, CONF_sshprot) != 3)
3161 ssh_send_verstring(ssh, protoname, s->version);
3163 if (ssh->version == 2) {
3166 * Record their version string.
3168 len = strcspn(s->vstring, "\015\012");
3169 ssh->v_s = snewn(len + 1, char);
3170 memcpy(ssh->v_s, s->vstring, len);
3174 * Initialise SSH-2 protocol.
3176 ssh->protocol = ssh2_protocol;
3177 ssh2_protocol_setup(ssh);
3178 ssh->s_rdpkt = ssh2_rdpkt;
3181 * Initialise SSH-1 protocol.
3183 ssh->protocol = ssh1_protocol;
3184 ssh1_protocol_setup(ssh);
3185 ssh->s_rdpkt = ssh1_rdpkt;
3187 if (ssh->version == 2)
3188 do_ssh2_transport(ssh, NULL, -1, NULL);
3190 update_specials_menu(ssh->frontend);
3191 ssh->state = SSH_STATE_BEFORE_SIZE;
3192 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3199 static int do_ssh_connection_init(Ssh ssh, unsigned char c)
3202 * Ordinary SSH begins with the banner "SSH-x.y-...". This is just
3203 * the ssh-connection part, extracted and given a trivial binary
3204 * packet protocol, so we replace 'SSH-' at the start with a new
3205 * name. In proper SSH style (though of course this part of the
3206 * proper SSH protocol _isn't_ subject to this kind of
3207 * DNS-domain-based extension), we define the new name in our
3210 static const char protoname[] =
3211 "SSHCONNECTION@putty.projects.tartarus.org-";
3213 struct do_ssh_connection_init_state {
3221 crState(do_ssh_connection_init_state);
3225 /* Search for a line beginning with the protocol name prefix in
3228 for (s->i = 0; protoname[s->i]; s->i++) {
3229 if ((char)c != protoname[s->i]) goto no;
3239 s->vstrsize = sizeof(protoname) + 16;
3240 s->vstring = snewn(s->vstrsize, char);
3241 strcpy(s->vstring, protoname);
3242 s->vslen = strlen(protoname);
3245 if (s->vslen >= s->vstrsize - 1) {
3247 s->vstring = sresize(s->vstring, s->vstrsize, char);
3249 s->vstring[s->vslen++] = c;
3252 s->version[s->i] = '\0';
3254 } else if (s->i < sizeof(s->version) - 1)
3255 s->version[s->i++] = c;
3256 } else if (c == '\012')
3258 crReturn(1); /* get another char */
3261 ssh->agentfwd_enabled = FALSE;
3262 ssh->rdpkt2_bare_state.incoming_sequence = 0;
3264 s->vstring[s->vslen] = 0;
3265 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
3266 logeventf(ssh, "Server version: %s", s->vstring);
3267 ssh_detect_bugs(ssh, s->vstring);
3270 * Decide which SSH protocol version to support. This is easy in
3271 * bare ssh-connection mode: only 2.0 is legal.
3273 if (ssh_versioncmp(s->version, "2.0") < 0) {
3274 bombout(("Server announces compatibility with SSH-1 in bare ssh-connection protocol"));
3277 if (conf_get_int(ssh->conf, CONF_sshprot) == 0) {
3278 bombout(("Bare ssh-connection protocol cannot be run in SSH-1-only mode"));
3284 logeventf(ssh, "Using bare ssh-connection protocol");
3286 /* Send the version string, if we haven't already */
3287 ssh_send_verstring(ssh, protoname, s->version);
3290 * Initialise bare connection protocol.
3292 ssh->protocol = ssh2_bare_connection_protocol;
3293 ssh2_bare_connection_protocol_setup(ssh);
3294 ssh->s_rdpkt = ssh2_bare_connection_rdpkt;
3296 update_specials_menu(ssh->frontend);
3297 ssh->state = SSH_STATE_BEFORE_SIZE;
3298 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3301 * Get authconn (really just conn) under way.
3303 do_ssh2_authconn(ssh, NULL, 0, NULL);
3310 static void ssh_process_incoming_data(Ssh ssh,
3311 const unsigned char **data, int *datalen)
3313 struct Packet *pktin;
3315 pktin = ssh->s_rdpkt(ssh, data, datalen);
3317 ssh->protocol(ssh, NULL, 0, pktin);
3318 ssh_free_packet(pktin);
3322 static void ssh_queue_incoming_data(Ssh ssh,
3323 const unsigned char **data, int *datalen)
3325 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
3330 static void ssh_process_queued_incoming_data(Ssh ssh)
3333 const unsigned char *data;
3336 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
3337 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
3341 while (!ssh->frozen && len > 0)
3342 ssh_process_incoming_data(ssh, &data, &len);
3345 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
3349 static void ssh_set_frozen(Ssh ssh, int frozen)
3352 sk_set_frozen(ssh->s, frozen);
3353 ssh->frozen = frozen;
3356 static void ssh_gotdata(Ssh ssh, const unsigned char *data, int datalen)
3358 /* Log raw data, if we're in that mode. */
3360 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
3361 0, NULL, NULL, 0, NULL);
3363 crBegin(ssh->ssh_gotdata_crstate);
3366 * To begin with, feed the characters one by one to the
3367 * protocol initialisation / selection function do_ssh_init().
3368 * When that returns 0, we're done with the initial greeting
3369 * exchange and can move on to packet discipline.
3372 int ret; /* need not be kept across crReturn */
3374 crReturnV; /* more data please */
3375 ret = ssh->do_ssh_init(ssh, *data);
3383 * We emerge from that loop when the initial negotiation is
3384 * over and we have selected an s_rdpkt function. Now pass
3385 * everything to s_rdpkt, and then pass the resulting packets
3386 * to the proper protocol handler.
3390 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
3392 ssh_queue_incoming_data(ssh, &data, &datalen);
3393 /* This uses up all data and cannot cause anything interesting
3394 * to happen; indeed, for anything to happen at all, we must
3395 * return, so break out. */
3397 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
3398 /* This uses up some or all data, and may freeze the
3400 ssh_process_queued_incoming_data(ssh);
3402 /* This uses up some or all data, and may freeze the
3404 ssh_process_incoming_data(ssh, &data, &datalen);
3406 /* FIXME this is probably EBW. */
3407 if (ssh->state == SSH_STATE_CLOSED)
3410 /* We're out of data. Go and get some more. */
3416 static int ssh_do_close(Ssh ssh, int notify_exit)
3419 struct ssh_channel *c;
3421 ssh->state = SSH_STATE_CLOSED;
3422 expire_timer_context(ssh);
3427 notify_remote_exit(ssh->frontend);
3432 * Now we must shut down any port- and X-forwarded channels going
3433 * through this connection.
3435 if (ssh->channels) {
3436 while (NULL != (c = index234(ssh->channels, 0))) {
3439 x11_close(c->u.x11.xconn);
3442 case CHAN_SOCKDATA_DORMANT:
3443 pfd_close(c->u.pfd.pf);
3446 del234(ssh->channels, c); /* moving next one to index 0 */
3447 if (ssh->version == 2)
3448 bufchain_clear(&c->v.v2.outbuffer);
3453 * Go through port-forwardings, and close any associated
3454 * listening sockets.
3456 if (ssh->portfwds) {
3457 struct ssh_portfwd *pf;
3458 while (NULL != (pf = index234(ssh->portfwds, 0))) {
3459 /* Dispose of any listening socket. */
3461 pfl_terminate(pf->local);
3462 del234(ssh->portfwds, pf); /* moving next one to index 0 */
3465 freetree234(ssh->portfwds);
3466 ssh->portfwds = NULL;
3470 * Also stop attempting to connection-share.
3472 if (ssh->connshare) {
3473 sharestate_free(ssh->connshare);
3474 ssh->connshare = NULL;
3480 static void ssh_socket_log(Plug plug, int type, SockAddr addr, int port,
3481 const char *error_msg, int error_code)
3483 Ssh ssh = (Ssh) plug;
3486 * While we're attempting connection sharing, don't loudly log
3487 * everything that happens. Real TCP connections need to be logged
3488 * when we _start_ trying to connect, because it might be ages
3489 * before they respond if something goes wrong; but connection
3490 * sharing is local and quick to respond, and it's sufficient to
3491 * simply wait and see whether it worked afterwards.
3494 if (!ssh->attempting_connshare)
3495 backend_socket_log(ssh->frontend, type, addr, port,
3496 error_msg, error_code, ssh->conf,
3497 ssh->session_started);
3500 void ssh_connshare_log(Ssh ssh, int event, const char *logtext,
3501 const char *ds_err, const char *us_err)
3503 if (event == SHARE_NONE) {
3504 /* In this case, 'logtext' is an error message indicating a
3505 * reason why connection sharing couldn't be set up _at all_.
3506 * Failing that, ds_err and us_err indicate why we couldn't be
3507 * a downstream and an upstream respectively. */
3509 logeventf(ssh, "Could not set up connection sharing: %s", logtext);
3512 logeventf(ssh, "Could not set up connection sharing"
3513 " as downstream: %s", ds_err);
3515 logeventf(ssh, "Could not set up connection sharing"
3516 " as upstream: %s", us_err);
3518 } else if (event == SHARE_DOWNSTREAM) {
3519 /* In this case, 'logtext' is a local endpoint address */
3520 logeventf(ssh, "Using existing shared connection at %s", logtext);
3521 /* Also we should mention this in the console window to avoid
3522 * confusing users as to why this window doesn't behave the
3524 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3525 c_write_str(ssh,"Reusing a shared connection to this server.\r\n");
3527 } else if (event == SHARE_UPSTREAM) {
3528 /* In this case, 'logtext' is a local endpoint address too */
3529 logeventf(ssh, "Sharing this connection at %s", logtext);
3533 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
3536 Ssh ssh = (Ssh) plug;
3537 int need_notify = ssh_do_close(ssh, FALSE);
3540 if (!ssh->close_expected)
3541 error_msg = "Server unexpectedly closed network connection";
3543 error_msg = "Server closed network connection";
3546 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
3550 notify_remote_exit(ssh->frontend);
3553 logevent(error_msg);
3554 if (!ssh->close_expected || !ssh->clean_exit)
3555 connection_fatal(ssh->frontend, "%s", error_msg);
3559 static int ssh_receive(Plug plug, int urgent, char *data, int len)
3561 Ssh ssh = (Ssh) plug;
3562 ssh_gotdata(ssh, (unsigned char *)data, len);
3563 if (ssh->state == SSH_STATE_CLOSED) {
3564 ssh_do_close(ssh, TRUE);
3570 static void ssh_sent(Plug plug, int bufsize)
3572 Ssh ssh = (Ssh) plug;
3574 * If the send backlog on the SSH socket itself clears, we
3575 * should unthrottle the whole world if it was throttled.
3577 if (bufsize < SSH_MAX_BACKLOG)
3578 ssh_throttle_all(ssh, 0, bufsize);
3581 static void ssh_hostport_setup(const char *host, int port, Conf *conf,
3582 char **savedhost, int *savedport,
3585 char *loghost = conf_get_str(conf, CONF_loghost);
3587 *loghost_ret = loghost;
3593 tmphost = dupstr(loghost);
3594 *savedport = 22; /* default ssh port */
3597 * A colon suffix on the hostname string also lets us affect
3598 * savedport. (Unless there are multiple colons, in which case
3599 * we assume this is an unbracketed IPv6 literal.)
3601 colon = host_strrchr(tmphost, ':');
3602 if (colon && colon == host_strchr(tmphost, ':')) {
3605 *savedport = atoi(colon);
3608 *savedhost = host_strduptrim(tmphost);
3611 *savedhost = host_strduptrim(host);
3613 port = 22; /* default ssh port */
3618 static int ssh_test_for_upstream(const char *host, int port, Conf *conf)
3624 random_ref(); /* platform may need this to determine share socket name */
3625 ssh_hostport_setup(host, port, conf, &savedhost, &savedport, NULL);
3626 ret = ssh_share_test_for_upstream(savedhost, savedport, conf);
3634 * Connect to specified host and port.
3635 * Returns an error message, or NULL on success.
3636 * Also places the canonical host name into `realhost'. It must be
3637 * freed by the caller.
3639 static const char *connect_to_host(Ssh ssh, const char *host, int port,
3640 char **realhost, int nodelay, int keepalive)
3642 static const struct plug_function_table fn_table = {
3653 int addressfamily, sshprot;
3655 ssh_hostport_setup(host, port, ssh->conf,
3656 &ssh->savedhost, &ssh->savedport, &loghost);
3658 ssh->fn = &fn_table; /* make 'ssh' usable as a Plug */
3661 * Try connection-sharing, in case that means we don't open a
3662 * socket after all. ssh_connection_sharing_init will connect to a
3663 * previously established upstream if it can, and failing that,
3664 * establish a listening socket for _us_ to be the upstream. In
3665 * the latter case it will return NULL just as if it had done
3666 * nothing, because here we only need to care if we're a
3667 * downstream and need to do our connection setup differently.
3669 ssh->connshare = NULL;
3670 ssh->attempting_connshare = TRUE; /* affects socket logging behaviour */
3671 ssh->s = ssh_connection_sharing_init(ssh->savedhost, ssh->savedport,
3672 ssh->conf, ssh, &ssh->connshare);
3673 ssh->attempting_connshare = FALSE;
3674 if (ssh->s != NULL) {
3676 * We are a downstream.
3678 ssh->bare_connection = TRUE;
3679 ssh->do_ssh_init = do_ssh_connection_init;
3680 ssh->fullhostname = NULL;
3681 *realhost = dupstr(host); /* best we can do */
3684 * We're not a downstream, so open a normal socket.
3686 ssh->do_ssh_init = do_ssh_init;
3691 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
3692 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily,
3693 ssh->frontend, "SSH connection");
3694 if ((err = sk_addr_error(addr)) != NULL) {
3698 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3700 ssh->s = new_connection(addr, *realhost, port,
3701 0, 1, nodelay, keepalive,
3702 (Plug) ssh, ssh->conf);
3703 if ((err = sk_socket_error(ssh->s)) != NULL) {
3705 notify_remote_exit(ssh->frontend);
3711 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3712 * send the version string too.
3714 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3717 if (sshprot == 3 && !ssh->bare_connection) {
3719 ssh_send_verstring(ssh, "SSH-", NULL);
3723 * loghost, if configured, overrides realhost.
3727 *realhost = dupstr(loghost);
3734 * Throttle or unthrottle the SSH connection.
3736 static void ssh_throttle_conn(Ssh ssh, int adjust)
3738 int old_count = ssh->conn_throttle_count;
3739 ssh->conn_throttle_count += adjust;
3740 assert(ssh->conn_throttle_count >= 0);
3741 if (ssh->conn_throttle_count && !old_count) {
3742 ssh_set_frozen(ssh, 1);
3743 } else if (!ssh->conn_throttle_count && old_count) {
3744 ssh_set_frozen(ssh, 0);
3749 * Throttle or unthrottle _all_ local data streams (for when sends
3750 * on the SSH connection itself back up).
3752 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3755 struct ssh_channel *c;
3757 if (enable == ssh->throttled_all)
3759 ssh->throttled_all = enable;
3760 ssh->overall_bufsize = bufsize;
3763 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3765 case CHAN_MAINSESSION:
3767 * This is treated separately, outside the switch.
3771 x11_override_throttle(c->u.x11.xconn, enable);
3774 /* Agent channels require no buffer management. */
3777 pfd_override_throttle(c->u.pfd.pf, enable);
3783 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3785 Ssh ssh = (Ssh) sshv;
3787 ssh->agent_response = reply;
3788 ssh->agent_response_len = replylen;
3790 if (ssh->version == 1)
3791 do_ssh1_login(ssh, NULL, -1, NULL);
3793 do_ssh2_authconn(ssh, NULL, -1, NULL);
3796 static void ssh_dialog_callback(void *sshv, int ret)
3798 Ssh ssh = (Ssh) sshv;
3800 ssh->user_response = ret;
3802 if (ssh->version == 1)
3803 do_ssh1_login(ssh, NULL, -1, NULL);
3805 do_ssh2_transport(ssh, NULL, -1, NULL);
3808 * This may have unfrozen the SSH connection, so do a
3811 ssh_process_queued_incoming_data(ssh);
3814 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3816 struct ssh_channel *c = (struct ssh_channel *)cv;
3818 const void *sentreply = reply;
3820 c->u.a.outstanding_requests--;
3822 /* Fake SSH_AGENT_FAILURE. */
3823 sentreply = "\0\0\0\1\5";
3826 if (ssh->version == 2) {
3827 ssh2_add_channel_data(c, sentreply, replylen);
3830 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3831 PKT_INT, c->remoteid,
3833 PKT_DATA, 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 if (ssh->version == 1) {
5012 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
5013 PKT_INT, c->remoteid,
5014 PKT_INT, len, PKT_DATA, buf, len,
5017 * In SSH-1 we can return 0 here - implying that forwarded
5018 * connections are never individually throttled - because
5019 * the only circumstance that can cause throttling will be
5020 * the whole SSH connection backing up, in which case
5021 * _everything_ will be throttled as a whole.
5025 ssh2_add_channel_data(c, buf, len);
5026 return ssh2_try_send(c);
5030 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
5035 if (ssh->state == SSH_STATE_CLOSED)
5038 if (ssh->version == 1) {
5039 buflimit = SSH1_BUFFER_LIMIT;
5041 buflimit = c->v.v2.locmaxwin;
5042 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
5044 if (c->throttling_conn && bufsize <= buflimit) {
5045 c->throttling_conn = 0;
5046 ssh_throttle_conn(ssh, -1);
5050 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
5052 struct queued_handler *qh = ssh->qhead;
5056 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
5059 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
5060 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
5063 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
5064 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
5068 ssh->qhead = qh->next;
5070 if (ssh->qhead->msg1 > 0) {
5071 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
5072 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
5074 if (ssh->qhead->msg2 > 0) {
5075 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
5076 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
5079 ssh->qhead = ssh->qtail = NULL;
5082 qh->handler(ssh, pktin, qh->ctx);
5087 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
5088 chandler_fn_t handler, void *ctx)
5090 struct queued_handler *qh;
5092 qh = snew(struct queued_handler);
5095 qh->handler = handler;
5099 if (ssh->qtail == NULL) {
5103 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
5104 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
5107 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
5108 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
5111 ssh->qtail->next = qh;
5116 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
5118 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
5120 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
5121 SSH2_MSG_REQUEST_SUCCESS)) {
5122 logeventf(ssh, "Remote port forwarding from %s enabled",
5125 logeventf(ssh, "Remote port forwarding from %s refused",
5128 rpf = del234(ssh->rportfwds, pf);
5130 pf->pfrec->remote = NULL;
5135 int ssh_alloc_sharing_rportfwd(Ssh ssh, const char *shost, int sport,
5138 struct ssh_rportfwd *pf = snew(struct ssh_rportfwd);
5141 pf->share_ctx = share_ctx;
5142 pf->shost = dupstr(shost);
5144 pf->sportdesc = NULL;
5145 if (!ssh->rportfwds) {
5146 assert(ssh->version == 2);
5147 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5149 if (add234(ssh->rportfwds, pf) != pf) {
5157 static void ssh_sharing_global_request_response(Ssh ssh, struct Packet *pktin,
5160 share_got_pkt_from_server(ctx, pktin->type,
5161 pktin->body, pktin->length);
5164 void ssh_sharing_queue_global_request(Ssh ssh, void *share_ctx)
5166 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, SSH2_MSG_REQUEST_FAILURE,
5167 ssh_sharing_global_request_response, share_ctx);
5170 static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
5172 struct ssh_portfwd *epf;
5176 if (!ssh->portfwds) {
5177 ssh->portfwds = newtree234(ssh_portcmp);
5180 * Go through the existing port forwardings and tag them
5181 * with status==DESTROY. Any that we want to keep will be
5182 * re-enabled (status==KEEP) as we go through the
5183 * configuration and find out which bits are the same as
5186 struct ssh_portfwd *epf;
5188 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5189 epf->status = DESTROY;
5192 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
5194 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
5195 char *kp, *kp2, *vp, *vp2;
5196 char address_family, type;
5197 int sport,dport,sserv,dserv;
5198 char *sports, *dports, *saddr, *host;
5202 address_family = 'A';
5204 if (*kp == 'A' || *kp == '4' || *kp == '6')
5205 address_family = *kp++;
5206 if (*kp == 'L' || *kp == 'R')
5209 if ((kp2 = host_strchr(kp, ':')) != NULL) {
5211 * There's a colon in the middle of the source port
5212 * string, which means that the part before it is
5213 * actually a source address.
5215 char *saddr_tmp = dupprintf("%.*s", (int)(kp2 - kp), kp);
5216 saddr = host_strduptrim(saddr_tmp);
5223 sport = atoi(sports);
5227 sport = net_service_lookup(sports);
5229 logeventf(ssh, "Service lookup failed for source"
5230 " port \"%s\"", sports);
5234 if (type == 'L' && !strcmp(val, "D")) {
5235 /* dynamic forwarding */
5242 /* ordinary forwarding */
5244 vp2 = vp + host_strcspn(vp, ":");
5245 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
5249 dport = atoi(dports);
5253 dport = net_service_lookup(dports);
5255 logeventf(ssh, "Service lookup failed for destination"
5256 " port \"%s\"", dports);
5261 if (sport && dport) {
5262 /* Set up a description of the source port. */
5263 struct ssh_portfwd *pfrec, *epfrec;
5265 pfrec = snew(struct ssh_portfwd);
5267 pfrec->saddr = saddr;
5268 pfrec->sserv = sserv ? dupstr(sports) : NULL;
5269 pfrec->sport = sport;
5270 pfrec->daddr = host;
5271 pfrec->dserv = dserv ? dupstr(dports) : NULL;
5272 pfrec->dport = dport;
5273 pfrec->local = NULL;
5274 pfrec->remote = NULL;
5275 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
5276 address_family == '6' ? ADDRTYPE_IPV6 :
5279 epfrec = add234(ssh->portfwds, pfrec);
5280 if (epfrec != pfrec) {
5281 if (epfrec->status == DESTROY) {
5283 * We already have a port forwarding up and running
5284 * with precisely these parameters. Hence, no need
5285 * to do anything; simply re-tag the existing one
5288 epfrec->status = KEEP;
5291 * Anything else indicates that there was a duplicate
5292 * in our input, which we'll silently ignore.
5294 free_portfwd(pfrec);
5296 pfrec->status = CREATE;
5305 * Now go through and destroy any port forwardings which were
5308 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5309 if (epf->status == DESTROY) {
5312 message = dupprintf("%s port forwarding from %s%s%d",
5313 epf->type == 'L' ? "local" :
5314 epf->type == 'R' ? "remote" : "dynamic",
5315 epf->saddr ? epf->saddr : "",
5316 epf->saddr ? ":" : "",
5319 if (epf->type != 'D') {
5320 char *msg2 = dupprintf("%s to %s:%d", message,
5321 epf->daddr, epf->dport);
5326 logeventf(ssh, "Cancelling %s", message);
5329 /* epf->remote or epf->local may be NULL if setting up a
5330 * forwarding failed. */
5332 struct ssh_rportfwd *rpf = epf->remote;
5333 struct Packet *pktout;
5336 * Cancel the port forwarding at the server
5339 if (ssh->version == 1) {
5341 * We cannot cancel listening ports on the
5342 * server side in SSH-1! There's no message
5343 * to support it. Instead, we simply remove
5344 * the rportfwd record from the local end
5345 * so that any connections the server tries
5346 * to make on it are rejected.
5349 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5350 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
5351 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
5353 ssh2_pkt_addstring(pktout, epf->saddr);
5354 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5355 /* XXX: rport_acceptall may not represent
5356 * what was used to open the original connection,
5357 * since it's reconfigurable. */
5358 ssh2_pkt_addstring(pktout, "");
5360 ssh2_pkt_addstring(pktout, "localhost");
5362 ssh2_pkt_adduint32(pktout, epf->sport);
5363 ssh2_pkt_send(ssh, pktout);
5366 del234(ssh->rportfwds, rpf);
5368 } else if (epf->local) {
5369 pfl_terminate(epf->local);
5372 delpos234(ssh->portfwds, i);
5374 i--; /* so we don't skip one in the list */
5378 * And finally, set up any new port forwardings (status==CREATE).
5380 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5381 if (epf->status == CREATE) {
5382 char *sportdesc, *dportdesc;
5383 sportdesc = dupprintf("%s%s%s%s%d%s",
5384 epf->saddr ? epf->saddr : "",
5385 epf->saddr ? ":" : "",
5386 epf->sserv ? epf->sserv : "",
5387 epf->sserv ? "(" : "",
5389 epf->sserv ? ")" : "");
5390 if (epf->type == 'D') {
5393 dportdesc = dupprintf("%s:%s%s%d%s",
5395 epf->dserv ? epf->dserv : "",
5396 epf->dserv ? "(" : "",
5398 epf->dserv ? ")" : "");
5401 if (epf->type == 'L') {
5402 char *err = pfl_listen(epf->daddr, epf->dport,
5403 epf->saddr, epf->sport,
5404 ssh, conf, &epf->local,
5405 epf->addressfamily);
5407 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
5408 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5409 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5410 sportdesc, dportdesc,
5411 err ? " failed: " : "", err ? err : "");
5414 } else if (epf->type == 'D') {
5415 char *err = pfl_listen(NULL, -1, epf->saddr, epf->sport,
5416 ssh, conf, &epf->local,
5417 epf->addressfamily);
5419 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
5420 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5421 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5423 err ? " failed: " : "", err ? err : "");
5428 struct ssh_rportfwd *pf;
5431 * Ensure the remote port forwardings tree exists.
5433 if (!ssh->rportfwds) {
5434 if (ssh->version == 1)
5435 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
5437 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5440 pf = snew(struct ssh_rportfwd);
5441 pf->share_ctx = NULL;
5442 pf->dhost = dupstr(epf->daddr);
5443 pf->dport = epf->dport;
5445 pf->shost = dupstr(epf->saddr);
5446 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5447 pf->shost = dupstr("");
5449 pf->shost = dupstr("localhost");
5451 pf->sport = epf->sport;
5452 if (add234(ssh->rportfwds, pf) != pf) {
5453 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
5454 epf->daddr, epf->dport);
5457 logeventf(ssh, "Requesting remote port %s"
5458 " forward to %s", sportdesc, dportdesc);
5460 pf->sportdesc = sportdesc;
5465 if (ssh->version == 1) {
5466 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
5467 PKT_INT, epf->sport,
5468 PKT_STR, epf->daddr,
5469 PKT_INT, epf->dport,
5471 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
5473 ssh_rportfwd_succfail, pf);
5475 struct Packet *pktout;
5476 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5477 ssh2_pkt_addstring(pktout, "tcpip-forward");
5478 ssh2_pkt_addbool(pktout, 1);/* want reply */
5479 ssh2_pkt_addstring(pktout, pf->shost);
5480 ssh2_pkt_adduint32(pktout, pf->sport);
5481 ssh2_pkt_send(ssh, pktout);
5483 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
5484 SSH2_MSG_REQUEST_FAILURE,
5485 ssh_rportfwd_succfail, pf);
5494 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
5497 int stringlen, bufsize;
5499 ssh_pkt_getstring(pktin, &string, &stringlen);
5500 if (string == NULL) {
5501 bombout(("Incoming terminal data packet was badly formed"));
5505 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
5507 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
5508 ssh->v1_stdout_throttling = 1;
5509 ssh_throttle_conn(ssh, +1);
5513 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
5515 /* Remote side is trying to open a channel to talk to our
5516 * X-Server. Give them back a local channel number. */
5517 struct ssh_channel *c;
5518 int remoteid = ssh_pkt_getuint32(pktin);
5520 logevent("Received X11 connect request");
5521 /* Refuse if X11 forwarding is disabled. */
5522 if (!ssh->X11_fwd_enabled) {
5523 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5524 PKT_INT, remoteid, PKT_END);
5525 logevent("Rejected X11 connect request");
5527 c = snew(struct ssh_channel);
5530 c->u.x11.xconn = x11_init(ssh->x11authtree, c, NULL, -1);
5531 c->remoteid = remoteid;
5532 c->halfopen = FALSE;
5533 c->localid = alloc_channel_id(ssh);
5535 c->pending_eof = FALSE;
5536 c->throttling_conn = 0;
5537 c->type = CHAN_X11; /* identify channel type */
5538 add234(ssh->channels, c);
5539 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5540 PKT_INT, c->remoteid, PKT_INT,
5541 c->localid, PKT_END);
5542 logevent("Opened X11 forward channel");
5546 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
5548 /* Remote side is trying to open a channel to talk to our
5549 * agent. Give them back a local channel number. */
5550 struct ssh_channel *c;
5551 int remoteid = ssh_pkt_getuint32(pktin);
5553 /* Refuse if agent forwarding is disabled. */
5554 if (!ssh->agentfwd_enabled) {
5555 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5556 PKT_INT, remoteid, PKT_END);
5558 c = snew(struct ssh_channel);
5560 c->remoteid = remoteid;
5561 c->halfopen = FALSE;
5562 c->localid = alloc_channel_id(ssh);
5564 c->pending_eof = FALSE;
5565 c->throttling_conn = 0;
5566 c->type = CHAN_AGENT; /* identify channel type */
5567 c->u.a.lensofar = 0;
5568 c->u.a.message = NULL;
5569 c->u.a.outstanding_requests = 0;
5570 add234(ssh->channels, c);
5571 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5572 PKT_INT, c->remoteid, PKT_INT, c->localid,
5577 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
5579 /* Remote side is trying to open a channel to talk to a
5580 * forwarded port. Give them back a local channel number. */
5581 struct ssh_rportfwd pf, *pfp;
5587 remoteid = ssh_pkt_getuint32(pktin);
5588 ssh_pkt_getstring(pktin, &host, &hostsize);
5589 port = ssh_pkt_getuint32(pktin);
5591 pf.dhost = dupprintf("%.*s", hostsize, NULLTOEMPTY(host));
5593 pfp = find234(ssh->rportfwds, &pf, NULL);
5596 logeventf(ssh, "Rejected remote port open request for %s:%d",
5598 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5599 PKT_INT, remoteid, PKT_END);
5601 struct ssh_channel *c = snew(struct ssh_channel);
5604 logeventf(ssh, "Received remote port open request for %s:%d",
5606 err = pfd_connect(&c->u.pfd.pf, pf.dhost, port,
5607 c, ssh->conf, pfp->pfrec->addressfamily);
5609 logeventf(ssh, "Port open failed: %s", err);
5612 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5613 PKT_INT, remoteid, PKT_END);
5615 c->remoteid = remoteid;
5616 c->halfopen = FALSE;
5617 c->localid = alloc_channel_id(ssh);
5619 c->pending_eof = FALSE;
5620 c->throttling_conn = 0;
5621 c->type = CHAN_SOCKDATA; /* identify channel type */
5622 add234(ssh->channels, c);
5623 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5624 PKT_INT, c->remoteid, PKT_INT,
5625 c->localid, PKT_END);
5626 logevent("Forwarded port opened successfully");
5633 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5635 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5636 unsigned int localid = ssh_pkt_getuint32(pktin);
5637 struct ssh_channel *c;
5639 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5640 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5641 c->remoteid = localid;
5642 c->halfopen = FALSE;
5643 c->type = CHAN_SOCKDATA;
5644 c->throttling_conn = 0;
5645 pfd_confirm(c->u.pfd.pf);
5648 if (c && c->pending_eof) {
5650 * We have a pending close on this channel,
5651 * which we decided on before the server acked
5652 * the channel open. So now we know the
5653 * remoteid, we can close it again.
5655 ssh_channel_try_eof(c);
5659 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5661 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5662 struct ssh_channel *c;
5664 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5665 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5666 logevent("Forwarded connection refused by server");
5667 pfd_close(c->u.pfd.pf);
5668 del234(ssh->channels, c);
5673 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
5675 /* Remote side closes a channel. */
5676 unsigned i = ssh_pkt_getuint32(pktin);
5677 struct ssh_channel *c;
5678 c = find234(ssh->channels, &i, ssh_channelfind);
5679 if (c && !c->halfopen) {
5681 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
5682 !(c->closes & CLOSES_RCVD_EOF)) {
5684 * Received CHANNEL_CLOSE, which we translate into
5687 int send_close = FALSE;
5689 c->closes |= CLOSES_RCVD_EOF;
5694 x11_send_eof(c->u.x11.xconn);
5700 pfd_send_eof(c->u.pfd.pf);
5709 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
5710 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
5712 c->closes |= CLOSES_SENT_EOF;
5716 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
5717 !(c->closes & CLOSES_RCVD_CLOSE)) {
5719 if (!(c->closes & CLOSES_SENT_EOF)) {
5720 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
5721 " for which we never sent CHANNEL_CLOSE\n", i));
5724 c->closes |= CLOSES_RCVD_CLOSE;
5727 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
5728 !(c->closes & CLOSES_SENT_CLOSE)) {
5729 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
5730 PKT_INT, c->remoteid, PKT_END);
5731 c->closes |= CLOSES_SENT_CLOSE;
5734 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5735 ssh_channel_destroy(c);
5737 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5738 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
5739 "_CONFIRMATION", c ? "half-open" : "nonexistent",
5744 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5746 /* Data sent down one of our channels. */
5747 int i = ssh_pkt_getuint32(pktin);
5750 struct ssh_channel *c;
5752 ssh_pkt_getstring(pktin, &p, &len);
5754 c = find234(ssh->channels, &i, ssh_channelfind);
5759 bufsize = x11_send(c->u.x11.xconn, p, len);
5762 bufsize = pfd_send(c->u.pfd.pf, p, len);
5765 /* Data for an agent message. Buffer it. */
5767 if (c->u.a.lensofar < 4) {
5768 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
5769 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
5773 c->u.a.lensofar += l;
5775 if (c->u.a.lensofar == 4) {
5777 4 + GET_32BIT(c->u.a.msglen);
5778 c->u.a.message = snewn(c->u.a.totallen,
5780 memcpy(c->u.a.message, c->u.a.msglen, 4);
5782 if (c->u.a.lensofar >= 4 && len > 0) {
5784 min(c->u.a.totallen - c->u.a.lensofar,
5786 memcpy(c->u.a.message + c->u.a.lensofar, p,
5790 c->u.a.lensofar += l;
5792 if (c->u.a.lensofar == c->u.a.totallen) {
5795 c->u.a.outstanding_requests++;
5796 if (agent_query(c->u.a.message,
5799 ssh_agentf_callback, c))
5800 ssh_agentf_callback(c, reply, replylen);
5801 sfree(c->u.a.message);
5802 c->u.a.lensofar = 0;
5805 bufsize = 0; /* agent channels never back up */
5808 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5809 c->throttling_conn = 1;
5810 ssh_throttle_conn(ssh, +1);
5815 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5817 ssh->exitcode = ssh_pkt_getuint32(pktin);
5818 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5819 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5821 * In case `helpful' firewalls or proxies tack
5822 * extra human-readable text on the end of the
5823 * session which we might mistake for another
5824 * encrypted packet, we close the session once
5825 * we've sent EXIT_CONFIRMATION.
5827 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5830 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5831 static void ssh1_send_ttymode(void *data, char *mode, char *val)
5833 struct Packet *pktout = (struct Packet *)data;
5835 unsigned int arg = 0;
5836 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5837 if (i == lenof(ssh_ttymodes)) return;
5838 switch (ssh_ttymodes[i].type) {
5840 arg = ssh_tty_parse_specchar(val);
5843 arg = ssh_tty_parse_boolean(val);
5846 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5847 ssh2_pkt_addbyte(pktout, arg);
5850 int ssh_agent_forwarding_permitted(Ssh ssh)
5852 return conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists();
5855 static void do_ssh1_connection(Ssh ssh, const unsigned char *in, int inlen,
5856 struct Packet *pktin)
5858 crBegin(ssh->do_ssh1_connection_crstate);
5860 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5861 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5862 ssh1_smsg_stdout_stderr_data;
5864 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5865 ssh1_msg_channel_open_confirmation;
5866 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5867 ssh1_msg_channel_open_failure;
5868 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5869 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5870 ssh1_msg_channel_close;
5871 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5872 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5874 if (ssh_agent_forwarding_permitted(ssh)) {
5875 logevent("Requesting agent forwarding");
5876 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5880 if (pktin->type != SSH1_SMSG_SUCCESS
5881 && pktin->type != SSH1_SMSG_FAILURE) {
5882 bombout(("Protocol confusion"));
5884 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5885 logevent("Agent forwarding refused");
5887 logevent("Agent forwarding enabled");
5888 ssh->agentfwd_enabled = TRUE;
5889 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5893 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
5895 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5897 if (!ssh->x11disp) {
5898 /* FIXME: return an error message from x11_setup_display */
5899 logevent("X11 forwarding not enabled: unable to"
5900 " initialise X display");
5902 ssh->x11auth = x11_invent_fake_auth
5903 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
5904 ssh->x11auth->disp = ssh->x11disp;
5906 logevent("Requesting X11 forwarding");
5907 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5908 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5909 PKT_STR, ssh->x11auth->protoname,
5910 PKT_STR, ssh->x11auth->datastring,
5911 PKT_INT, ssh->x11disp->screennum,
5914 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5915 PKT_STR, ssh->x11auth->protoname,
5916 PKT_STR, ssh->x11auth->datastring,
5922 if (pktin->type != SSH1_SMSG_SUCCESS
5923 && pktin->type != SSH1_SMSG_FAILURE) {
5924 bombout(("Protocol confusion"));
5926 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5927 logevent("X11 forwarding refused");
5929 logevent("X11 forwarding enabled");
5930 ssh->X11_fwd_enabled = TRUE;
5931 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5936 ssh_setup_portfwd(ssh, ssh->conf);
5937 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5939 if (!conf_get_int(ssh->conf, CONF_nopty)) {
5941 /* Unpick the terminal-speed string. */
5942 /* XXX perhaps we should allow no speeds to be sent. */
5943 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5944 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
5945 /* Send the pty request. */
5946 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5947 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
5948 ssh_pkt_adduint32(pkt, ssh->term_height);
5949 ssh_pkt_adduint32(pkt, ssh->term_width);
5950 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5951 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5952 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
5953 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5954 ssh_pkt_adduint32(pkt, ssh->ispeed);
5955 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5956 ssh_pkt_adduint32(pkt, ssh->ospeed);
5957 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5959 ssh->state = SSH_STATE_INTERMED;
5963 if (pktin->type != SSH1_SMSG_SUCCESS
5964 && pktin->type != SSH1_SMSG_FAILURE) {
5965 bombout(("Protocol confusion"));
5967 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5968 c_write_str(ssh, "Server refused to allocate pty\r\n");
5969 ssh->editing = ssh->echoing = 1;
5971 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5972 ssh->ospeed, ssh->ispeed);
5973 ssh->got_pty = TRUE;
5976 ssh->editing = ssh->echoing = 1;
5979 if (conf_get_int(ssh->conf, CONF_compression)) {
5980 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5984 if (pktin->type != SSH1_SMSG_SUCCESS
5985 && pktin->type != SSH1_SMSG_FAILURE) {
5986 bombout(("Protocol confusion"));
5988 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5989 c_write_str(ssh, "Server refused to compress\r\n");
5991 logevent("Started compression");
5992 ssh->v1_compressing = TRUE;
5993 ssh->cs_comp_ctx = zlib_compress_init();
5994 logevent("Initialised zlib (RFC1950) compression");
5995 ssh->sc_comp_ctx = zlib_decompress_init();
5996 logevent("Initialised zlib (RFC1950) decompression");
6000 * Start the shell or command.
6002 * Special case: if the first-choice command is an SSH-2
6003 * subsystem (hence not usable here) and the second choice
6004 * exists, we fall straight back to that.
6007 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
6009 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
6010 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
6011 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
6012 ssh->fallback_cmd = TRUE;
6015 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
6017 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
6018 logevent("Started session");
6021 ssh->state = SSH_STATE_SESSION;
6022 if (ssh->size_needed)
6023 ssh_size(ssh, ssh->term_width, ssh->term_height);
6024 if (ssh->eof_needed)
6025 ssh_special(ssh, TS_EOF);
6028 ldisc_echoedit_update(ssh->ldisc); /* cause ldisc to notice changes */
6030 ssh->channels = newtree234(ssh_channelcmp);
6034 * By this point, most incoming packets are already being
6035 * handled by the dispatch table, and we need only pay
6036 * attention to the unusual ones.
6041 if (pktin->type == SSH1_SMSG_SUCCESS) {
6042 /* may be from EXEC_SHELL on some servers */
6043 } else if (pktin->type == SSH1_SMSG_FAILURE) {
6044 /* may be from EXEC_SHELL on some servers
6045 * if no pty is available or in other odd cases. Ignore */
6047 bombout(("Strange packet received: type %d", pktin->type));
6052 int len = min(inlen, 512);
6053 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
6054 PKT_INT, len, PKT_DATA, in, len,
6066 * Handle the top-level SSH-2 protocol.
6068 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
6073 ssh_pkt_getstring(pktin, &msg, &msglen);
6074 logeventf(ssh, "Remote debug message: %.*s", msglen, NULLTOEMPTY(msg));
6077 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
6079 /* log reason code in disconnect message */
6083 ssh_pkt_getstring(pktin, &msg, &msglen);
6084 bombout(("Server sent disconnect message:\n\"%.*s\"",
6085 msglen, NULLTOEMPTY(msg)));
6088 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
6090 /* Do nothing, because we're ignoring it! Duhh. */
6093 static void ssh1_protocol_setup(Ssh ssh)
6098 * Most messages are handled by the coroutines.
6100 for (i = 0; i < 256; i++)
6101 ssh->packet_dispatch[i] = NULL;
6104 * These special message types we install handlers for.
6106 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
6107 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
6108 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
6111 static void ssh1_protocol(Ssh ssh, const void *vin, int inlen,
6112 struct Packet *pktin)
6114 const unsigned char *in = (const unsigned char *)vin;
6115 if (ssh->state == SSH_STATE_CLOSED)
6118 if (pktin && ssh->packet_dispatch[pktin->type]) {
6119 ssh->packet_dispatch[pktin->type](ssh, pktin);
6123 if (!ssh->protocol_initial_phase_done) {
6124 if (do_ssh1_login(ssh, in, inlen, pktin))
6125 ssh->protocol_initial_phase_done = TRUE;
6130 do_ssh1_connection(ssh, in, inlen, pktin);
6134 * Utility routines for decoding comma-separated strings in KEXINIT.
6136 static int first_in_commasep_string(char const *needle, char const *haystack,
6140 if (!needle || !haystack) /* protect against null pointers */
6142 needlen = strlen(needle);
6144 if (haylen >= needlen && /* haystack is long enough */
6145 !memcmp(needle, haystack, needlen) && /* initial match */
6146 (haylen == needlen || haystack[needlen] == ',')
6147 /* either , or EOS follows */
6153 static int in_commasep_string(char const *needle, char const *haystack,
6158 if (!needle || !haystack) /* protect against null pointers */
6161 * Is it at the start of the string?
6163 if (first_in_commasep_string(needle, haystack, haylen))
6166 * If not, search for the next comma and resume after that.
6167 * If no comma found, terminate.
6169 p = memchr(haystack, ',', haylen);
6171 /* + 1 to skip over comma */
6172 return in_commasep_string(needle, p + 1, haylen - (p + 1 - haystack));
6176 * Add a value to the comma-separated string at the end of the packet.
6178 static void ssh2_pkt_addstring_commasep(struct Packet *pkt, const char *data)
6180 if (pkt->length - pkt->savedpos > 0)
6181 ssh_pkt_addstring_str(pkt, ",");
6182 ssh_pkt_addstring_str(pkt, data);
6187 * SSH-2 key derivation (RFC 4253 section 7.2).
6189 static unsigned char *ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
6190 char chr, int keylen)
6192 const struct ssh_hash *h = ssh->kex->hash;
6200 /* Round up to the next multiple of hash length. */
6201 keylen_padded = ((keylen + h->hlen - 1) / h->hlen) * h->hlen;
6203 key = snewn(keylen_padded, unsigned char);
6205 /* First hlen bytes. */
6207 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6208 hash_mpint(h, s, K);
6209 h->bytes(s, H, h->hlen);
6210 h->bytes(s, &chr, 1);
6211 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
6214 /* Subsequent blocks of hlen bytes. */
6215 if (keylen_padded > h->hlen) {
6219 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6220 hash_mpint(h, s, K);
6221 h->bytes(s, H, h->hlen);
6223 for (offset = h->hlen; offset < keylen_padded; offset += h->hlen) {
6224 h->bytes(s, key + offset - h->hlen, h->hlen);
6226 h->final(s2, key + offset);
6232 /* Now clear any extra bytes of key material beyond the length
6233 * we're officially returning, because the caller won't know to
6235 if (keylen_padded > keylen)
6236 smemclr(key + keylen, keylen_padded - keylen);
6242 * Structure for constructing KEXINIT algorithm lists.
6244 #define MAXKEXLIST 16
6245 struct kexinit_algorithm {
6249 const struct ssh_kex *kex;
6253 const struct ssh_signkey *hostkey;
6257 const struct ssh2_cipher *cipher;
6261 const struct ssh_mac *mac;
6264 const struct ssh_compress *comp;
6269 * Find a slot in a KEXINIT algorithm list to use for a new algorithm.
6270 * If the algorithm is already in the list, return a pointer to its
6271 * entry, otherwise return an entry from the end of the list.
6272 * This assumes that every time a particular name is passed in, it
6273 * comes from the same string constant. If this isn't true, this
6274 * function may need to be rewritten to use strcmp() instead.
6276 static struct kexinit_algorithm *ssh2_kexinit_addalg(struct kexinit_algorithm
6277 *list, const char *name)
6281 for (i = 0; i < MAXKEXLIST; i++)
6282 if (list[i].name == NULL || list[i].name == name) {
6283 list[i].name = name;
6286 assert(!"No space in KEXINIT list");
6291 * Handle the SSH-2 transport layer.
6293 static void do_ssh2_transport(Ssh ssh, const void *vin, int inlen,
6294 struct Packet *pktin)
6296 const unsigned char *in = (const unsigned char *)vin;
6298 KEXLIST_KEX, KEXLIST_HOSTKEY, KEXLIST_CSCIPHER, KEXLIST_SCCIPHER,
6299 KEXLIST_CSMAC, KEXLIST_SCMAC, KEXLIST_CSCOMP, KEXLIST_SCCOMP,
6302 const char * kexlist_descr[NKEXLIST] = {
6303 "key exchange algorithm", "host key algorithm",
6304 "client-to-server cipher", "server-to-client cipher",
6305 "client-to-server MAC", "server-to-client MAC",
6306 "client-to-server compression method",
6307 "server-to-client compression method" };
6308 struct do_ssh2_transport_state {
6310 int nbits, pbits, warn_kex, warn_hk, warn_cscipher, warn_sccipher;
6311 Bignum p, g, e, f, K;
6314 int kex_init_value, kex_reply_value;
6315 const struct ssh_mac *const *maclist;
6317 const struct ssh2_cipher *cscipher_tobe;
6318 const struct ssh2_cipher *sccipher_tobe;
6319 const struct ssh_mac *csmac_tobe;
6320 const struct ssh_mac *scmac_tobe;
6321 int csmac_etm_tobe, scmac_etm_tobe;
6322 const struct ssh_compress *cscomp_tobe;
6323 const struct ssh_compress *sccomp_tobe;
6324 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
6325 int hostkeylen, siglen, rsakeylen;
6326 void *hkey; /* actual host key */
6327 void *rsakey; /* for RSA kex */
6328 void *eckey; /* for ECDH kex */
6329 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
6330 int n_preferred_kex;
6331 const struct ssh_kexes *preferred_kex[KEX_MAX];
6333 int preferred_hk[HK_MAX];
6334 int n_preferred_ciphers;
6335 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
6336 const struct ssh_compress *preferred_comp;
6337 int userauth_succeeded; /* for delayed compression */
6338 int pending_compression;
6339 int got_session_id, activated_authconn;
6340 struct Packet *pktout;
6344 struct kexinit_algorithm kexlists[NKEXLIST][MAXKEXLIST];
6346 crState(do_ssh2_transport_state);
6348 assert(!ssh->bare_connection);
6352 s->cscipher_tobe = s->sccipher_tobe = NULL;
6353 s->csmac_tobe = s->scmac_tobe = NULL;
6354 s->cscomp_tobe = s->sccomp_tobe = NULL;
6356 s->got_session_id = s->activated_authconn = FALSE;
6357 s->userauth_succeeded = FALSE;
6358 s->pending_compression = FALSE;
6361 * Be prepared to work around the buggy MAC problem.
6363 if (ssh->remote_bugs & BUG_SSH2_HMAC)
6364 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
6366 s->maclist = macs, s->nmacs = lenof(macs);
6369 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
6372 struct kexinit_algorithm *alg;
6375 * Set up the preferred key exchange. (NULL => warn below here)
6377 s->n_preferred_kex = 0;
6378 for (i = 0; i < KEX_MAX; i++) {
6379 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
6381 s->preferred_kex[s->n_preferred_kex++] =
6382 &ssh_diffiehellman_gex;
6385 s->preferred_kex[s->n_preferred_kex++] =
6386 &ssh_diffiehellman_group14;
6389 s->preferred_kex[s->n_preferred_kex++] =
6390 &ssh_diffiehellman_group1;
6393 s->preferred_kex[s->n_preferred_kex++] =
6397 s->preferred_kex[s->n_preferred_kex++] =
6401 /* Flag for later. Don't bother if it's the last in
6403 if (i < KEX_MAX - 1) {
6404 s->preferred_kex[s->n_preferred_kex++] = NULL;
6411 * Set up the preferred host key types. These are just the ids
6412 * in the enum in putty.h, so 'warn below here' is indicated
6415 s->n_preferred_hk = 0;
6416 for (i = 0; i < HK_MAX; i++) {
6417 int id = conf_get_int_int(ssh->conf, CONF_ssh_hklist, i);
6418 /* As above, don't bother with HK_WARN if it's last in the
6420 if (id != HK_WARN || i < HK_MAX - 1)
6421 s->preferred_hk[s->n_preferred_hk++] = id;
6425 * Set up the preferred ciphers. (NULL => warn below here)
6427 s->n_preferred_ciphers = 0;
6428 for (i = 0; i < CIPHER_MAX; i++) {
6429 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
6430 case CIPHER_BLOWFISH:
6431 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
6434 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
6435 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
6439 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
6442 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
6444 case CIPHER_ARCFOUR:
6445 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
6447 case CIPHER_CHACHA20:
6448 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_ccp;
6451 /* Flag for later. Don't bother if it's the last in
6453 if (i < CIPHER_MAX - 1) {
6454 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
6461 * Set up preferred compression.
6463 if (conf_get_int(ssh->conf, CONF_compression))
6464 s->preferred_comp = &ssh_zlib;
6466 s->preferred_comp = &ssh_comp_none;
6469 * Enable queueing of outgoing auth- or connection-layer
6470 * packets while we are in the middle of a key exchange.
6472 ssh->queueing = TRUE;
6475 * Flag that KEX is in progress.
6477 ssh->kex_in_progress = TRUE;
6479 for (i = 0; i < NKEXLIST; i++)
6480 for (j = 0; j < MAXKEXLIST; j++)
6481 s->kexlists[i][j].name = NULL;
6482 /* List key exchange algorithms. */
6484 for (i = 0; i < s->n_preferred_kex; i++) {
6485 const struct ssh_kexes *k = s->preferred_kex[i];
6486 if (!k) warn = TRUE;
6487 else for (j = 0; j < k->nkexes; j++) {
6488 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_KEX],
6490 alg->u.kex.kex = k->list[j];
6491 alg->u.kex.warn = warn;
6494 /* List server host key algorithms. */
6495 if (!s->got_session_id) {
6497 * In the first key exchange, we list all the algorithms
6498 * we're prepared to cope with, but prefer those algorithms
6499 * for which we have a host key for this host.
6501 * If the host key algorithm is below the warning
6502 * threshold, we warn even if we did already have a key
6503 * for it, on the basis that if the user has just
6504 * reconfigured that host key type to be warned about,
6505 * they surely _do_ want to be alerted that a server
6506 * they're actually connecting to is using it.
6509 for (i = 0; i < s->n_preferred_hk; i++) {
6510 if (s->preferred_hk[i] == HK_WARN)
6512 for (j = 0; j < lenof(hostkey_algs); j++) {
6513 if (hostkey_algs[j].id != s->preferred_hk[i])
6515 if (have_ssh_host_key(ssh->savedhost, ssh->savedport,
6516 hostkey_algs[j].alg->keytype)) {
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 for (i = 0; i < s->n_preferred_hk; i++) {
6526 if (s->preferred_hk[i] == HK_WARN)
6528 for (j = 0; j < lenof(hostkey_algs); j++) {
6529 if (hostkey_algs[j].id != s->preferred_hk[i])
6531 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY],
6532 hostkey_algs[j].alg->name);
6533 alg->u.hk.hostkey = hostkey_algs[j].alg;
6534 alg->u.hk.warn = warn;
6539 * In subsequent key exchanges, we list only the kex
6540 * algorithm that was selected in the first key exchange,
6541 * so that we keep getting the same host key and hence
6542 * don't have to interrupt the user's session to ask for
6546 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY],
6547 ssh->hostkey->name);
6548 alg->u.hk.hostkey = ssh->hostkey;
6549 alg->u.hk.warn = FALSE;
6551 /* List encryption algorithms (client->server then server->client). */
6552 for (k = KEXLIST_CSCIPHER; k <= KEXLIST_SCCIPHER; k++) {
6555 alg = ssh2_kexinit_addalg(s->kexlists[k], "none");
6556 alg->u.cipher.cipher = NULL;
6557 alg->u.cipher.warn = warn;
6558 #endif /* FUZZING */
6559 for (i = 0; i < s->n_preferred_ciphers; i++) {
6560 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6561 if (!c) warn = TRUE;
6562 else for (j = 0; j < c->nciphers; j++) {
6563 alg = ssh2_kexinit_addalg(s->kexlists[k],
6565 alg->u.cipher.cipher = c->list[j];
6566 alg->u.cipher.warn = warn;
6570 /* List MAC algorithms (client->server then server->client). */
6571 for (j = KEXLIST_CSMAC; j <= KEXLIST_SCMAC; j++) {
6573 alg = ssh2_kexinit_addalg(s->kexlists[j], "none");
6574 alg->u.mac.mac = NULL;
6575 alg->u.mac.etm = FALSE;
6576 #endif /* FUZZING */
6577 for (i = 0; i < s->nmacs; i++) {
6578 alg = ssh2_kexinit_addalg(s->kexlists[j], s->maclist[i]->name);
6579 alg->u.mac.mac = s->maclist[i];
6580 alg->u.mac.etm = FALSE;
6582 for (i = 0; i < s->nmacs; i++)
6583 /* For each MAC, there may also be an ETM version,
6584 * which we list second. */
6585 if (s->maclist[i]->etm_name) {
6586 alg = ssh2_kexinit_addalg(s->kexlists[j],
6587 s->maclist[i]->etm_name);
6588 alg->u.mac.mac = s->maclist[i];
6589 alg->u.mac.etm = TRUE;
6592 /* List client->server compression algorithms,
6593 * then server->client compression algorithms. (We use the
6594 * same set twice.) */
6595 for (j = KEXLIST_CSCOMP; j <= KEXLIST_SCCOMP; j++) {
6596 assert(lenof(compressions) > 1);
6597 /* Prefer non-delayed versions */
6598 alg = ssh2_kexinit_addalg(s->kexlists[j], s->preferred_comp->name);
6599 alg->u.comp = s->preferred_comp;
6600 /* We don't even list delayed versions of algorithms until
6601 * they're allowed to be used, to avoid a race. See the end of
6603 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
6604 alg = ssh2_kexinit_addalg(s->kexlists[j],
6605 s->preferred_comp->delayed_name);
6606 alg->u.comp = s->preferred_comp;
6608 for (i = 0; i < lenof(compressions); i++) {
6609 const struct ssh_compress *c = compressions[i];
6610 alg = ssh2_kexinit_addalg(s->kexlists[j], c->name);
6612 if (s->userauth_succeeded && c->delayed_name) {
6613 alg = ssh2_kexinit_addalg(s->kexlists[j], c->delayed_name);
6619 * Construct and send our key exchange packet.
6621 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
6622 for (i = 0; i < 16; i++)
6623 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
6624 for (i = 0; i < NKEXLIST; i++) {
6625 ssh2_pkt_addstring_start(s->pktout);
6626 for (j = 0; j < MAXKEXLIST; j++) {
6627 if (s->kexlists[i][j].name == NULL) break;
6628 ssh2_pkt_addstring_commasep(s->pktout, s->kexlists[i][j].name);
6631 /* List client->server languages. Empty list. */
6632 ssh2_pkt_addstring_start(s->pktout);
6633 /* List server->client languages. Empty list. */
6634 ssh2_pkt_addstring_start(s->pktout);
6635 /* First KEX packet does _not_ follow, because we're not that brave. */
6636 ssh2_pkt_addbool(s->pktout, FALSE);
6638 ssh2_pkt_adduint32(s->pktout, 0);
6641 s->our_kexinitlen = s->pktout->length - 5;
6642 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
6643 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
6645 ssh2_pkt_send_noqueue(ssh, s->pktout);
6648 crWaitUntilV(pktin);
6651 * Now examine the other side's KEXINIT to see what we're up
6658 if (pktin->type != SSH2_MSG_KEXINIT) {
6659 bombout(("expected key exchange packet from server"));
6663 ssh->hostkey = NULL;
6664 s->cscipher_tobe = NULL;
6665 s->sccipher_tobe = NULL;
6666 s->csmac_tobe = NULL;
6667 s->scmac_tobe = NULL;
6668 s->cscomp_tobe = NULL;
6669 s->sccomp_tobe = NULL;
6670 s->warn_kex = s->warn_hk = FALSE;
6671 s->warn_cscipher = s->warn_sccipher = FALSE;
6673 pktin->savedpos += 16; /* skip garbage cookie */
6676 for (i = 0; i < NKEXLIST; i++) {
6677 ssh_pkt_getstring(pktin, &str, &len);
6679 bombout(("KEXINIT packet was incomplete"));
6683 /* If we've already selected a cipher which requires a
6684 * particular MAC, then just select that, and don't even
6685 * bother looking through the server's KEXINIT string for
6687 if (i == KEXLIST_CSMAC && s->cscipher_tobe &&
6688 s->cscipher_tobe->required_mac) {
6689 s->csmac_tobe = s->cscipher_tobe->required_mac;
6690 s->csmac_etm_tobe = !!(s->csmac_tobe->etm_name);
6693 if (i == KEXLIST_SCMAC && s->sccipher_tobe &&
6694 s->sccipher_tobe->required_mac) {
6695 s->scmac_tobe = s->sccipher_tobe->required_mac;
6696 s->scmac_etm_tobe = !!(s->scmac_tobe->etm_name);
6700 for (j = 0; j < MAXKEXLIST; j++) {
6701 struct kexinit_algorithm *alg = &s->kexlists[i][j];
6702 if (alg->name == NULL) break;
6703 if (in_commasep_string(alg->name, str, len)) {
6704 /* We've found a matching algorithm. */
6705 if (i == KEXLIST_KEX || i == KEXLIST_HOSTKEY) {
6706 /* Check if we might need to ignore first kex pkt */
6708 !first_in_commasep_string(alg->name, str, len))
6711 if (i == KEXLIST_KEX) {
6712 ssh->kex = alg->u.kex.kex;
6713 s->warn_kex = alg->u.kex.warn;
6714 } else if (i == KEXLIST_HOSTKEY) {
6715 ssh->hostkey = alg->u.hk.hostkey;
6716 s->warn_hk = alg->u.hk.warn;
6717 } else if (i == KEXLIST_CSCIPHER) {
6718 s->cscipher_tobe = alg->u.cipher.cipher;
6719 s->warn_cscipher = alg->u.cipher.warn;
6720 } else if (i == KEXLIST_SCCIPHER) {
6721 s->sccipher_tobe = alg->u.cipher.cipher;
6722 s->warn_sccipher = alg->u.cipher.warn;
6723 } else if (i == KEXLIST_CSMAC) {
6724 s->csmac_tobe = alg->u.mac.mac;
6725 s->csmac_etm_tobe = alg->u.mac.etm;
6726 } else if (i == KEXLIST_SCMAC) {
6727 s->scmac_tobe = alg->u.mac.mac;
6728 s->scmac_etm_tobe = alg->u.mac.etm;
6729 } else if (i == KEXLIST_CSCOMP) {
6730 s->cscomp_tobe = alg->u.comp;
6731 } else if (i == KEXLIST_SCCOMP) {
6732 s->sccomp_tobe = alg->u.comp;
6736 if ((i == KEXLIST_CSCOMP || i == KEXLIST_SCCOMP) &&
6737 in_commasep_string(alg->u.comp->delayed_name, str, len))
6738 s->pending_compression = TRUE; /* try this later */
6740 bombout(("Couldn't agree a %s (available: %.*s)",
6741 kexlist_descr[i], len, str));
6745 if (i == KEXLIST_HOSTKEY) {
6749 * In addition to deciding which host key we're
6750 * actually going to use, we should make a list of the
6751 * host keys offered by the server which we _don't_
6752 * have cached. These will be offered as cross-
6753 * certification options by ssh_get_specials.
6755 * We also count the key we're currently using for KEX
6756 * as one we've already got, because by the time this
6757 * menu becomes visible, it will be.
6759 ssh->n_uncert_hostkeys = 0;
6761 for (j = 0; j < lenof(hostkey_algs); j++) {
6762 if (hostkey_algs[j].alg != ssh->hostkey &&
6763 in_commasep_string(hostkey_algs[j].alg->name,
6765 !have_ssh_host_key(ssh->savedhost, ssh->savedport,
6766 hostkey_algs[j].alg->keytype)) {
6767 ssh->uncert_hostkeys[ssh->n_uncert_hostkeys++] = j;
6773 if (s->pending_compression) {
6774 logevent("Server supports delayed compression; "
6775 "will try this later");
6777 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
6778 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
6779 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
6781 ssh->exhash = ssh->kex->hash->init();
6782 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
6783 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
6784 hash_string(ssh->kex->hash, ssh->exhash,
6785 s->our_kexinit, s->our_kexinitlen);
6786 sfree(s->our_kexinit);
6787 /* Include the type byte in the hash of server's KEXINIT */
6788 hash_string(ssh->kex->hash, ssh->exhash,
6789 pktin->body - 1, pktin->length + 1);
6792 ssh_set_frozen(ssh, 1);
6793 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
6795 ssh_dialog_callback, ssh);
6796 if (s->dlgret < 0) {
6800 bombout(("Unexpected data from server while"
6801 " waiting for user response"));
6804 } while (pktin || inlen > 0);
6805 s->dlgret = ssh->user_response;
6807 ssh_set_frozen(ssh, 0);
6808 if (s->dlgret == 0) {
6809 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
6816 ssh_set_frozen(ssh, 1);
6817 s->dlgret = askalg(ssh->frontend, "host key type",
6819 ssh_dialog_callback, ssh);
6820 if (s->dlgret < 0) {
6824 bombout(("Unexpected data from server while"
6825 " waiting for user response"));
6828 } while (pktin || inlen > 0);
6829 s->dlgret = ssh->user_response;
6831 ssh_set_frozen(ssh, 0);
6832 if (s->dlgret == 0) {
6833 ssh_disconnect(ssh, "User aborted at host key warning", NULL,
6839 if (s->warn_cscipher) {
6840 ssh_set_frozen(ssh, 1);
6841 s->dlgret = askalg(ssh->frontend,
6842 "client-to-server cipher",
6843 s->cscipher_tobe->name,
6844 ssh_dialog_callback, ssh);
6845 if (s->dlgret < 0) {
6849 bombout(("Unexpected data from server while"
6850 " waiting for user response"));
6853 } while (pktin || inlen > 0);
6854 s->dlgret = ssh->user_response;
6856 ssh_set_frozen(ssh, 0);
6857 if (s->dlgret == 0) {
6858 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6864 if (s->warn_sccipher) {
6865 ssh_set_frozen(ssh, 1);
6866 s->dlgret = askalg(ssh->frontend,
6867 "server-to-client cipher",
6868 s->sccipher_tobe->name,
6869 ssh_dialog_callback, ssh);
6870 if (s->dlgret < 0) {
6874 bombout(("Unexpected data from server while"
6875 " waiting for user response"));
6878 } while (pktin || inlen > 0);
6879 s->dlgret = ssh->user_response;
6881 ssh_set_frozen(ssh, 0);
6882 if (s->dlgret == 0) {
6883 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6889 if (s->ignorepkt) /* first_kex_packet_follows */
6890 crWaitUntilV(pktin); /* Ignore packet */
6893 if (ssh->kex->main_type == KEXTYPE_DH) {
6895 * Work out the number of bits of key we will need from the
6896 * key exchange. We start with the maximum key length of
6902 csbits = s->cscipher_tobe ? s->cscipher_tobe->real_keybits : 0;
6903 scbits = s->sccipher_tobe ? s->sccipher_tobe->real_keybits : 0;
6904 s->nbits = (csbits > scbits ? csbits : scbits);
6906 /* The keys only have hlen-bit entropy, since they're based on
6907 * a hash. So cap the key size at hlen bits. */
6908 if (s->nbits > ssh->kex->hash->hlen * 8)
6909 s->nbits = ssh->kex->hash->hlen * 8;
6912 * If we're doing Diffie-Hellman group exchange, start by
6913 * requesting a group.
6915 if (dh_is_gex(ssh->kex)) {
6916 logevent("Doing Diffie-Hellman group exchange");
6917 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
6919 * Work out how big a DH group we will need to allow that
6922 s->pbits = 512 << ((s->nbits - 1) / 64);
6923 if (s->pbits < DH_MIN_SIZE)
6924 s->pbits = DH_MIN_SIZE;
6925 if (s->pbits > DH_MAX_SIZE)
6926 s->pbits = DH_MAX_SIZE;
6927 if ((ssh->remote_bugs & BUG_SSH2_OLDGEX)) {
6928 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST_OLD);
6929 ssh2_pkt_adduint32(s->pktout, s->pbits);
6931 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6932 ssh2_pkt_adduint32(s->pktout, DH_MIN_SIZE);
6933 ssh2_pkt_adduint32(s->pktout, s->pbits);
6934 ssh2_pkt_adduint32(s->pktout, DH_MAX_SIZE);
6936 ssh2_pkt_send_noqueue(ssh, s->pktout);
6938 crWaitUntilV(pktin);
6939 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6940 bombout(("expected key exchange group packet from server"));
6943 s->p = ssh2_pkt_getmp(pktin);
6944 s->g = ssh2_pkt_getmp(pktin);
6945 if (!s->p || !s->g) {
6946 bombout(("unable to read mp-ints from incoming group packet"));
6949 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6950 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6951 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6953 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
6954 ssh->kex_ctx = dh_setup_group(ssh->kex);
6955 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6956 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6957 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6958 ssh->kex->groupname);
6961 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6962 ssh->kex->hash->text_name);
6964 * Now generate and send e for Diffie-Hellman.
6966 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6967 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6968 s->pktout = ssh2_pkt_init(s->kex_init_value);
6969 ssh2_pkt_addmp(s->pktout, s->e);
6970 ssh2_pkt_send_noqueue(ssh, s->pktout);
6972 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
6973 crWaitUntilV(pktin);
6974 if (pktin->type != s->kex_reply_value) {
6975 bombout(("expected key exchange reply packet from server"));
6978 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
6979 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6980 if (!s->hostkeydata) {
6981 bombout(("unable to parse key exchange reply packet"));
6984 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
6985 s->hostkeydata, s->hostkeylen);
6986 s->f = ssh2_pkt_getmp(pktin);
6988 bombout(("unable to parse key exchange reply packet"));
6991 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6993 bombout(("unable to parse key exchange reply packet"));
6998 const char *err = dh_validate_f(ssh->kex_ctx, s->f);
7000 bombout(("key exchange reply failed validation: %s", err));
7004 s->K = dh_find_K(ssh->kex_ctx, s->f);
7006 /* We assume everything from now on will be quick, and it might
7007 * involve user interaction. */
7008 set_busy_status(ssh->frontend, BUSY_NOT);
7010 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
7011 if (dh_is_gex(ssh->kex)) {
7012 if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX))
7013 hash_uint32(ssh->kex->hash, ssh->exhash, DH_MIN_SIZE);
7014 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
7015 if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX))
7016 hash_uint32(ssh->kex->hash, ssh->exhash, DH_MAX_SIZE);
7017 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
7018 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
7020 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
7021 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
7023 dh_cleanup(ssh->kex_ctx);
7025 if (dh_is_gex(ssh->kex)) {
7029 } else if (ssh->kex->main_type == KEXTYPE_ECDH) {
7031 logeventf(ssh, "Doing ECDH key exchange with curve %s and hash %s",
7032 ssh_ecdhkex_curve_textname(ssh->kex),
7033 ssh->kex->hash->text_name);
7034 ssh->pkt_kctx = SSH2_PKTCTX_ECDHKEX;
7036 s->eckey = ssh_ecdhkex_newkey(ssh->kex);
7038 bombout(("Unable to generate key for ECDH"));
7044 int publicPointLength;
7045 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
7047 ssh_ecdhkex_freekey(s->eckey);
7048 bombout(("Unable to encode public key for ECDH"));
7051 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_ECDH_INIT);
7052 ssh2_pkt_addstring_start(s->pktout);
7053 ssh2_pkt_addstring_data(s->pktout, publicPoint, publicPointLength);
7057 ssh2_pkt_send_noqueue(ssh, s->pktout);
7059 crWaitUntilV(pktin);
7060 if (pktin->type != SSH2_MSG_KEX_ECDH_REPLY) {
7061 ssh_ecdhkex_freekey(s->eckey);
7062 bombout(("expected ECDH reply packet from server"));
7066 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
7067 if (!s->hostkeydata) {
7068 bombout(("unable to parse ECDH reply packet"));
7071 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
7072 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
7073 s->hostkeydata, s->hostkeylen);
7077 int publicPointLength;
7078 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
7080 ssh_ecdhkex_freekey(s->eckey);
7081 bombout(("Unable to encode public key for ECDH hash"));
7084 hash_string(ssh->kex->hash, ssh->exhash,
7085 publicPoint, publicPointLength);
7092 ssh_pkt_getstring(pktin, &keydata, &keylen);
7094 bombout(("unable to parse ECDH reply packet"));
7097 hash_string(ssh->kex->hash, ssh->exhash, keydata, keylen);
7098 s->K = ssh_ecdhkex_getkey(s->eckey, keydata, keylen);
7100 ssh_ecdhkex_freekey(s->eckey);
7101 bombout(("point received in ECDH was not valid"));
7106 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
7108 bombout(("unable to parse key exchange reply packet"));
7112 ssh_ecdhkex_freekey(s->eckey);
7114 logeventf(ssh, "Doing RSA key exchange with hash %s",
7115 ssh->kex->hash->text_name);
7116 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
7118 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
7121 crWaitUntilV(pktin);
7122 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
7123 bombout(("expected RSA public key packet from server"));
7127 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
7128 if (!s->hostkeydata) {
7129 bombout(("unable to parse RSA public key packet"));
7132 hash_string(ssh->kex->hash, ssh->exhash,
7133 s->hostkeydata, s->hostkeylen);
7134 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
7135 s->hostkeydata, s->hostkeylen);
7139 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
7141 bombout(("unable to parse RSA public key packet"));
7144 s->rsakeydata = snewn(s->rsakeylen, char);
7145 memcpy(s->rsakeydata, keydata, s->rsakeylen);
7148 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
7150 sfree(s->rsakeydata);
7151 bombout(("unable to parse RSA public key from server"));
7155 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
7158 * Next, set up a shared secret K, of precisely KLEN -
7159 * 2*HLEN - 49 bits, where KLEN is the bit length of the
7160 * RSA key modulus and HLEN is the bit length of the hash
7164 int klen = ssh_rsakex_klen(s->rsakey);
7165 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
7167 unsigned char *kstr1, *kstr2, *outstr;
7168 int kstr1len, kstr2len, outstrlen;
7170 s->K = bn_power_2(nbits - 1);
7172 for (i = 0; i < nbits; i++) {
7174 byte = random_byte();
7176 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
7180 * Encode this as an mpint.
7182 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
7183 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
7184 PUT_32BIT(kstr2, kstr1len);
7185 memcpy(kstr2 + 4, kstr1, kstr1len);
7188 * Encrypt it with the given RSA key.
7190 outstrlen = (klen + 7) / 8;
7191 outstr = snewn(outstrlen, unsigned char);
7192 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
7193 outstr, outstrlen, s->rsakey);
7196 * And send it off in a return packet.
7198 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
7199 ssh2_pkt_addstring_start(s->pktout);
7200 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
7201 ssh2_pkt_send_noqueue(ssh, s->pktout);
7203 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
7210 ssh_rsakex_freekey(s->rsakey);
7212 crWaitUntilV(pktin);
7213 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
7214 sfree(s->rsakeydata);
7215 bombout(("expected signature packet from server"));
7219 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
7221 bombout(("unable to parse signature packet"));
7225 sfree(s->rsakeydata);
7228 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
7229 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
7230 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
7232 ssh->kex_ctx = NULL;
7235 debug(("Exchange hash is:\n"));
7236 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
7240 bombout(("Server's host key is invalid"));
7244 if (!ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
7245 (char *)s->exchange_hash,
7246 ssh->kex->hash->hlen)) {
7248 bombout(("Server's host key did not match the signature supplied"));
7253 s->keystr = ssh->hostkey->fmtkey(s->hkey);
7254 if (!s->got_session_id) {
7256 * Make a note of any host key format we'd have preferred to use,
7257 * had we already known the corresponding keys.
7262 for (i = 0; i < lenof(hostkey_algs); i++) {
7263 if (hostkey_algs[i].alg == ssh->hostkey)
7264 /* Not worth mentioning key types we wouldn't use */
7266 else if (ssh->uncert_hostkeys[j] == i) {
7269 newlist = dupprintf("%s/%s", list,
7270 hostkey_algs[i].alg->name);
7272 newlist = dupprintf("%s", hostkey_algs[i].alg->name);
7276 /* Assumes that hostkey_algs and uncert_hostkeys are
7277 * sorted in the same order */
7278 if (j == ssh->n_uncert_hostkeys)
7281 assert(ssh->uncert_hostkeys[j] >
7282 ssh->uncert_hostkeys[j-1]);
7287 "Server has %s host key%s, but we don't know %s; "
7289 list, j ? "s" : "", j ? "any of them" : "it",
7290 ssh->hostkey->name);
7296 * Authenticate remote host: verify host key. (We've already
7297 * checked the signature of the exchange hash.)
7299 s->fingerprint = ssh2_fingerprint(ssh->hostkey, s->hkey);
7300 logevent("Host key fingerprint is:");
7301 logevent(s->fingerprint);
7302 /* First check against manually configured host keys. */
7303 s->dlgret = verify_ssh_manual_host_key(ssh, s->fingerprint,
7304 ssh->hostkey, s->hkey);
7305 if (s->dlgret == 0) { /* did not match */
7306 bombout(("Host key did not appear in manually configured list"));
7308 } else if (s->dlgret < 0) { /* none configured; use standard handling */
7309 ssh_set_frozen(ssh, 1);
7310 s->dlgret = verify_ssh_host_key(ssh->frontend,
7311 ssh->savedhost, ssh->savedport,
7312 ssh->hostkey->keytype, s->keystr,
7314 ssh_dialog_callback, ssh);
7318 if (s->dlgret < 0) {
7322 bombout(("Unexpected data from server while waiting"
7323 " for user host key response"));
7326 } while (pktin || inlen > 0);
7327 s->dlgret = ssh->user_response;
7329 ssh_set_frozen(ssh, 0);
7330 if (s->dlgret == 0) {
7331 ssh_disconnect(ssh, "Aborted at host key verification", NULL,
7336 sfree(s->fingerprint);
7338 * Save this host key, to check against the one presented in
7339 * subsequent rekeys.
7341 ssh->hostkey_str = s->keystr;
7342 } else if (ssh->cross_certifying) {
7343 s->fingerprint = ssh2_fingerprint(ssh->hostkey, s->hkey);
7344 logevent("Storing additional host key for this host:");
7345 logevent(s->fingerprint);
7346 store_host_key(ssh->savedhost, ssh->savedport,
7347 ssh->hostkey->keytype, s->keystr);
7348 ssh->cross_certifying = FALSE;
7350 * Don't forget to store the new key as the one we'll be
7351 * re-checking in future normal rekeys.
7353 ssh->hostkey_str = s->keystr;
7356 * In a rekey, we never present an interactive host key
7357 * verification request to the user. Instead, we simply
7358 * enforce that the key we're seeing this time is identical to
7359 * the one we saw before.
7361 if (strcmp(ssh->hostkey_str, s->keystr)) {
7363 bombout(("Host key was different in repeat key exchange"));
7369 ssh->hostkey->freekey(s->hkey);
7372 * The exchange hash from the very first key exchange is also
7373 * the session id, used in session key construction and
7376 if (!s->got_session_id) {
7377 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
7378 memcpy(ssh->v2_session_id, s->exchange_hash,
7379 sizeof(s->exchange_hash));
7380 ssh->v2_session_id_len = ssh->kex->hash->hlen;
7381 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
7382 s->got_session_id = TRUE;
7386 * Send SSH2_MSG_NEWKEYS.
7388 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
7389 ssh2_pkt_send_noqueue(ssh, s->pktout);
7390 ssh->outgoing_data_size = 0; /* start counting from here */
7393 * We've sent client NEWKEYS, so create and initialise
7394 * client-to-server session keys.
7396 if (ssh->cs_cipher_ctx)
7397 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7398 ssh->cscipher = s->cscipher_tobe;
7399 if (ssh->cscipher) ssh->cs_cipher_ctx = ssh->cscipher->make_context();
7401 if (ssh->cs_mac_ctx)
7402 ssh->csmac->free_context(ssh->cs_mac_ctx);
7403 ssh->csmac = s->csmac_tobe;
7404 ssh->csmac_etm = s->csmac_etm_tobe;
7406 ssh->cs_mac_ctx = ssh->csmac->make_context(ssh->cs_cipher_ctx);
7408 if (ssh->cs_comp_ctx)
7409 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7410 ssh->cscomp = s->cscomp_tobe;
7411 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
7414 * Set IVs on client-to-server keys. Here we use the exchange
7415 * hash from the _first_ key exchange.
7417 if (ssh->cscipher) {
7420 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'C',
7421 ssh->cscipher->padded_keybytes);
7422 ssh->cscipher->setkey(ssh->cs_cipher_ctx, key);
7423 smemclr(key, ssh->cscipher->padded_keybytes);
7426 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'A',
7427 ssh->cscipher->blksize);
7428 ssh->cscipher->setiv(ssh->cs_cipher_ctx, key);
7429 smemclr(key, ssh->cscipher->blksize);
7435 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'E',
7436 ssh->csmac->keylen);
7437 ssh->csmac->setkey(ssh->cs_mac_ctx, key);
7438 smemclr(key, ssh->csmac->keylen);
7443 logeventf(ssh, "Initialised %.200s client->server encryption",
7444 ssh->cscipher->text_name);
7446 logeventf(ssh, "Initialised %.200s client->server MAC algorithm%s%s",
7447 ssh->csmac->text_name,
7448 ssh->csmac_etm ? " (in ETM mode)" : "",
7449 ssh->cscipher->required_mac ? " (required by cipher)" : "");
7450 if (ssh->cscomp->text_name)
7451 logeventf(ssh, "Initialised %s compression",
7452 ssh->cscomp->text_name);
7455 * Now our end of the key exchange is complete, we can send all
7456 * our queued higher-layer packets.
7458 ssh->queueing = FALSE;
7459 ssh2_pkt_queuesend(ssh);
7462 * Expect SSH2_MSG_NEWKEYS from server.
7464 crWaitUntilV(pktin);
7465 if (pktin->type != SSH2_MSG_NEWKEYS) {
7466 bombout(("expected new-keys packet from server"));
7469 ssh->incoming_data_size = 0; /* start counting from here */
7472 * We've seen server NEWKEYS, so create and initialise
7473 * server-to-client session keys.
7475 if (ssh->sc_cipher_ctx)
7476 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7477 if (s->sccipher_tobe) {
7478 ssh->sccipher = s->sccipher_tobe;
7479 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
7482 if (ssh->sc_mac_ctx)
7483 ssh->scmac->free_context(ssh->sc_mac_ctx);
7484 if (s->scmac_tobe) {
7485 ssh->scmac = s->scmac_tobe;
7486 ssh->scmac_etm = s->scmac_etm_tobe;
7487 ssh->sc_mac_ctx = ssh->scmac->make_context(ssh->sc_cipher_ctx);
7490 if (ssh->sc_comp_ctx)
7491 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7492 ssh->sccomp = s->sccomp_tobe;
7493 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
7496 * Set IVs on server-to-client keys. Here we use the exchange
7497 * hash from the _first_ key exchange.
7499 if (ssh->sccipher) {
7502 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'D',
7503 ssh->sccipher->padded_keybytes);
7504 ssh->sccipher->setkey(ssh->sc_cipher_ctx, key);
7505 smemclr(key, ssh->sccipher->padded_keybytes);
7508 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'B',
7509 ssh->sccipher->blksize);
7510 ssh->sccipher->setiv(ssh->sc_cipher_ctx, key);
7511 smemclr(key, ssh->sccipher->blksize);
7517 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'F',
7518 ssh->scmac->keylen);
7519 ssh->scmac->setkey(ssh->sc_mac_ctx, key);
7520 smemclr(key, ssh->scmac->keylen);
7524 logeventf(ssh, "Initialised %.200s server->client encryption",
7525 ssh->sccipher->text_name);
7527 logeventf(ssh, "Initialised %.200s server->client MAC algorithm%s%s",
7528 ssh->scmac->text_name,
7529 ssh->scmac_etm ? " (in ETM mode)" : "",
7530 ssh->sccipher->required_mac ? " (required by cipher)" : "");
7531 if (ssh->sccomp->text_name)
7532 logeventf(ssh, "Initialised %s decompression",
7533 ssh->sccomp->text_name);
7536 * Free shared secret.
7541 * Update the specials menu to list the remaining uncertified host
7544 update_specials_menu(ssh->frontend);
7547 * Key exchange is over. Loop straight back round if we have a
7548 * deferred rekey reason.
7550 if (ssh->deferred_rekey_reason) {
7551 logevent(ssh->deferred_rekey_reason);
7553 ssh->deferred_rekey_reason = NULL;
7554 goto begin_key_exchange;
7558 * Otherwise, schedule a timer for our next rekey.
7560 ssh->kex_in_progress = FALSE;
7561 ssh->last_rekey = GETTICKCOUNT();
7562 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
7563 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7567 * Now we're encrypting. Begin returning 1 to the protocol main
7568 * function so that other things can run on top of the
7569 * transport. If we ever see a KEXINIT, we must go back to the
7572 * We _also_ go back to the start if we see pktin==NULL and
7573 * inlen negative, because this is a special signal meaning
7574 * `initiate client-driven rekey', and `in' contains a message
7575 * giving the reason for the rekey.
7577 * inlen==-1 means always initiate a rekey;
7578 * inlen==-2 means that userauth has completed successfully and
7579 * we should consider rekeying (for delayed compression).
7581 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
7582 (!pktin && inlen < 0))) {
7584 if (!ssh->protocol_initial_phase_done) {
7585 ssh->protocol_initial_phase_done = TRUE;
7587 * Allow authconn to initialise itself.
7589 do_ssh2_authconn(ssh, NULL, 0, NULL);
7594 logevent("Server initiated key re-exchange");
7598 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
7599 * delayed compression, if it's available.
7601 * draft-miller-secsh-compression-delayed-00 says that you
7602 * negotiate delayed compression in the first key exchange, and
7603 * both sides start compressing when the server has sent
7604 * USERAUTH_SUCCESS. This has a race condition -- the server
7605 * can't know when the client has seen it, and thus which incoming
7606 * packets it should treat as compressed.
7608 * Instead, we do the initial key exchange without offering the
7609 * delayed methods, but note if the server offers them; when we
7610 * get here, if a delayed method was available that was higher
7611 * on our list than what we got, we initiate a rekey in which we
7612 * _do_ list the delayed methods (and hopefully get it as a
7613 * result). Subsequent rekeys will do the same.
7615 assert(!s->userauth_succeeded); /* should only happen once */
7616 s->userauth_succeeded = TRUE;
7617 if (!s->pending_compression)
7618 /* Can't see any point rekeying. */
7619 goto wait_for_rekey; /* this is utterly horrid */
7620 /* else fall through to rekey... */
7621 s->pending_compression = FALSE;
7624 * Now we've decided to rekey.
7626 * Special case: if the server bug is set that doesn't
7627 * allow rekeying, we give a different log message and
7628 * continue waiting. (If such a server _initiates_ a rekey,
7629 * we process it anyway!)
7631 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
7632 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
7634 /* Reset the counters, so that at least this message doesn't
7635 * hit the event log _too_ often. */
7636 ssh->outgoing_data_size = 0;
7637 ssh->incoming_data_size = 0;
7638 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
7640 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7643 goto wait_for_rekey; /* this is still utterly horrid */
7645 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
7648 goto begin_key_exchange;
7654 * Add data to an SSH-2 channel output buffer.
7656 static void ssh2_add_channel_data(struct ssh_channel *c, const char *buf,
7659 bufchain_add(&c->v.v2.outbuffer, buf, len);
7663 * Attempt to send data on an SSH-2 channel.
7665 static int ssh2_try_send(struct ssh_channel *c)
7668 struct Packet *pktout;
7671 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
7674 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
7675 if ((unsigned)len > c->v.v2.remwindow)
7676 len = c->v.v2.remwindow;
7677 if ((unsigned)len > c->v.v2.remmaxpkt)
7678 len = c->v.v2.remmaxpkt;
7679 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
7680 ssh2_pkt_adduint32(pktout, c->remoteid);
7681 ssh2_pkt_addstring_start(pktout);
7682 ssh2_pkt_addstring_data(pktout, data, len);
7683 ssh2_pkt_send(ssh, pktout);
7684 bufchain_consume(&c->v.v2.outbuffer, len);
7685 c->v.v2.remwindow -= len;
7689 * After having sent as much data as we can, return the amount
7692 ret = bufchain_size(&c->v.v2.outbuffer);
7695 * And if there's no data pending but we need to send an EOF, send
7698 if (!ret && c->pending_eof)
7699 ssh_channel_try_eof(c);
7704 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
7707 if (c->closes & CLOSES_SENT_EOF)
7708 return; /* don't send on channels we've EOFed */
7709 bufsize = ssh2_try_send(c);
7712 case CHAN_MAINSESSION:
7713 /* stdin need not receive an unthrottle
7714 * notification since it will be polled */
7717 x11_unthrottle(c->u.x11.xconn);
7720 /* agent sockets are request/response and need no
7721 * buffer management */
7724 pfd_unthrottle(c->u.pfd.pf);
7730 static int ssh_is_simple(Ssh ssh)
7733 * We use the 'simple' variant of the SSH protocol if we're asked
7734 * to, except not if we're also doing connection-sharing (either
7735 * tunnelling our packets over an upstream or expecting to be
7736 * tunnelled over ourselves), since then the assumption that we
7737 * have only one channel to worry about is not true after all.
7739 return (conf_get_int(ssh->conf, CONF_ssh_simple) &&
7740 !ssh->bare_connection && !ssh->connshare);
7744 * Set up most of a new ssh_channel for SSH-2.
7746 static void ssh2_channel_init(struct ssh_channel *c)
7749 c->localid = alloc_channel_id(ssh);
7751 c->pending_eof = FALSE;
7752 c->throttling_conn = FALSE;
7753 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
7754 ssh_is_simple(ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
7755 c->v.v2.chanreq_head = NULL;
7756 c->v.v2.throttle_state = UNTHROTTLED;
7757 bufchain_init(&c->v.v2.outbuffer);
7761 * Construct the common parts of a CHANNEL_OPEN.
7763 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c,
7766 struct Packet *pktout;
7768 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7769 ssh2_pkt_addstring(pktout, type);
7770 ssh2_pkt_adduint32(pktout, c->localid);
7771 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7772 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7777 * CHANNEL_FAILURE doesn't come with any indication of what message
7778 * caused it, so we have to keep track of the outstanding
7779 * CHANNEL_REQUESTs ourselves.
7781 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
7782 cchandler_fn_t handler, void *ctx)
7784 struct outstanding_channel_request *ocr =
7785 snew(struct outstanding_channel_request);
7787 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7788 ocr->handler = handler;
7791 if (!c->v.v2.chanreq_head)
7792 c->v.v2.chanreq_head = ocr;
7794 c->v.v2.chanreq_tail->next = ocr;
7795 c->v.v2.chanreq_tail = ocr;
7799 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
7800 * NULL then a reply will be requested and the handler will be called
7801 * when it arrives. The returned packet is ready to have any
7802 * request-specific data added and be sent. Note that if a handler is
7803 * provided, it's essential that the request actually be sent.
7805 * The handler will usually be passed the response packet in pktin. If
7806 * pktin is NULL, this means that no reply will ever be forthcoming
7807 * (e.g. because the entire connection is being destroyed, or because
7808 * the server initiated channel closure before we saw the response)
7809 * and the handler should free any storage it's holding.
7811 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c,
7813 cchandler_fn_t handler, void *ctx)
7815 struct Packet *pktout;
7817 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7818 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7819 ssh2_pkt_adduint32(pktout, c->remoteid);
7820 ssh2_pkt_addstring(pktout, type);
7821 ssh2_pkt_addbool(pktout, handler != NULL);
7822 if (handler != NULL)
7823 ssh2_queue_chanreq_handler(c, handler, ctx);
7828 * Potentially enlarge the window on an SSH-2 channel.
7830 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
7832 static void ssh2_set_window(struct ssh_channel *c, int newwin)
7837 * Never send WINDOW_ADJUST for a channel that the remote side has
7838 * already sent EOF on; there's no point, since it won't be
7839 * sending any more data anyway. Ditto if _we've_ already sent
7842 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
7846 * Also, never widen the window for an X11 channel when we're
7847 * still waiting to see its initial auth and may yet hand it off
7850 if (c->type == CHAN_X11 && c->u.x11.initial)
7854 * If the remote end has a habit of ignoring maxpkt, limit the
7855 * window so that it has no choice (assuming it doesn't ignore the
7858 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
7859 newwin = OUR_V2_MAXPKT;
7862 * Only send a WINDOW_ADJUST if there's significantly more window
7863 * available than the other end thinks there is. This saves us
7864 * sending a WINDOW_ADJUST for every character in a shell session.
7866 * "Significant" is arbitrarily defined as half the window size.
7868 if (newwin / 2 >= c->v.v2.locwindow) {
7869 struct Packet *pktout;
7873 * In order to keep track of how much window the client
7874 * actually has available, we'd like it to acknowledge each
7875 * WINDOW_ADJUST. We can't do that directly, so we accompany
7876 * it with a CHANNEL_REQUEST that has to be acknowledged.
7878 * This is only necessary if we're opening the window wide.
7879 * If we're not, then throughput is being constrained by
7880 * something other than the maximum window size anyway.
7882 if (newwin == c->v.v2.locmaxwin &&
7883 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
7884 up = snew(unsigned);
7885 *up = newwin - c->v.v2.locwindow;
7886 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
7887 ssh2_handle_winadj_response, up);
7888 ssh2_pkt_send(ssh, pktout);
7890 if (c->v.v2.throttle_state != UNTHROTTLED)
7891 c->v.v2.throttle_state = UNTHROTTLING;
7893 /* Pretend the WINDOW_ADJUST was acked immediately. */
7894 c->v.v2.remlocwin = newwin;
7895 c->v.v2.throttle_state = THROTTLED;
7897 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7898 ssh2_pkt_adduint32(pktout, c->remoteid);
7899 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
7900 ssh2_pkt_send(ssh, pktout);
7901 c->v.v2.locwindow = newwin;
7906 * Find the channel associated with a message. If there's no channel,
7907 * or it's not properly open, make a noise about it and return NULL.
7909 static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
7911 unsigned localid = ssh_pkt_getuint32(pktin);
7912 struct ssh_channel *c;
7914 c = find234(ssh->channels, &localid, ssh_channelfind);
7916 (c->type != CHAN_SHARING && c->halfopen &&
7917 pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
7918 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
7919 char *buf = dupprintf("Received %s for %s channel %u",
7920 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
7922 c ? "half-open" : "nonexistent", localid);
7923 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
7930 static void ssh2_handle_winadj_response(struct ssh_channel *c,
7931 struct Packet *pktin, void *ctx)
7933 unsigned *sizep = ctx;
7936 * Winadj responses should always be failures. However, at least
7937 * one server ("boks_sshd") is known to return SUCCESS for channel
7938 * requests it's never heard of, such as "winadj@putty". Raised
7939 * with foxt.com as bug 090916-090424, but for the sake of a quiet
7940 * life, we don't worry about what kind of response we got.
7943 c->v.v2.remlocwin += *sizep;
7946 * winadj messages are only sent when the window is fully open, so
7947 * if we get an ack of one, we know any pending unthrottle is
7950 if (c->v.v2.throttle_state == UNTHROTTLING)
7951 c->v.v2.throttle_state = UNTHROTTLED;
7954 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
7956 struct ssh_channel *c = ssh2_channel_msg(ssh, pktin);
7957 struct outstanding_channel_request *ocr;
7960 if (c->type == CHAN_SHARING) {
7961 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7962 pktin->body, pktin->length);
7965 ocr = c->v.v2.chanreq_head;
7967 ssh2_msg_unexpected(ssh, pktin);
7970 ocr->handler(c, pktin, ocr->ctx);
7971 c->v.v2.chanreq_head = ocr->next;
7974 * We may now initiate channel-closing procedures, if that
7975 * CHANNEL_REQUEST was the last thing outstanding before we send
7978 ssh2_channel_check_close(c);
7981 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
7983 struct ssh_channel *c;
7984 c = ssh2_channel_msg(ssh, pktin);
7987 if (c->type == CHAN_SHARING) {
7988 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7989 pktin->body, pktin->length);
7992 if (!(c->closes & CLOSES_SENT_EOF)) {
7993 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
7994 ssh2_try_send_and_unthrottle(ssh, c);
7998 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
8002 struct ssh_channel *c;
8003 c = ssh2_channel_msg(ssh, pktin);
8006 if (c->type == CHAN_SHARING) {
8007 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8008 pktin->body, pktin->length);
8011 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
8012 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
8013 return; /* extended but not stderr */
8014 ssh_pkt_getstring(pktin, &data, &length);
8017 c->v.v2.locwindow -= length;
8018 c->v.v2.remlocwin -= length;
8020 case CHAN_MAINSESSION:
8022 from_backend(ssh->frontend, pktin->type ==
8023 SSH2_MSG_CHANNEL_EXTENDED_DATA,
8027 bufsize = x11_send(c->u.x11.xconn, data, length);
8030 bufsize = pfd_send(c->u.pfd.pf, data, length);
8033 while (length > 0) {
8034 if (c->u.a.lensofar < 4) {
8035 unsigned int l = min(4 - c->u.a.lensofar,
8037 memcpy(c->u.a.msglen + c->u.a.lensofar,
8041 c->u.a.lensofar += l;
8043 if (c->u.a.lensofar == 4) {
8045 4 + GET_32BIT(c->u.a.msglen);
8046 c->u.a.message = snewn(c->u.a.totallen,
8048 memcpy(c->u.a.message, c->u.a.msglen, 4);
8050 if (c->u.a.lensofar >= 4 && length > 0) {
8052 min(c->u.a.totallen - c->u.a.lensofar,
8054 memcpy(c->u.a.message + c->u.a.lensofar,
8058 c->u.a.lensofar += l;
8060 if (c->u.a.lensofar == c->u.a.totallen) {
8063 c->u.a.outstanding_requests++;
8064 if (agent_query(c->u.a.message,
8067 ssh_agentf_callback, c))
8068 ssh_agentf_callback(c, reply, replylen);
8069 sfree(c->u.a.message);
8070 c->u.a.message = NULL;
8071 c->u.a.lensofar = 0;
8078 * If it looks like the remote end hit the end of its window,
8079 * and we didn't want it to do that, think about using a
8082 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
8083 c->v.v2.locmaxwin < 0x40000000)
8084 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
8086 * If we are not buffering too much data,
8087 * enlarge the window again at the remote side.
8088 * If we are buffering too much, we may still
8089 * need to adjust the window if the server's
8092 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
8093 c->v.v2.locmaxwin - bufsize : 0);
8095 * If we're either buffering way too much data, or if we're
8096 * buffering anything at all and we're in "simple" mode,
8097 * throttle the whole channel.
8099 if ((bufsize > c->v.v2.locmaxwin || (ssh_is_simple(ssh) && bufsize>0))
8100 && !c->throttling_conn) {
8101 c->throttling_conn = 1;
8102 ssh_throttle_conn(ssh, +1);
8107 static void ssh_check_termination(Ssh ssh)
8109 if (ssh->version == 2 &&
8110 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
8111 (ssh->channels && count234(ssh->channels) == 0) &&
8112 !(ssh->connshare && share_ndownstreams(ssh->connshare) > 0)) {
8114 * We used to send SSH_MSG_DISCONNECT here, because I'd
8115 * believed that _every_ conforming SSH-2 connection had to
8116 * end with a disconnect being sent by at least one side;
8117 * apparently I was wrong and it's perfectly OK to
8118 * unceremoniously slam the connection shut when you're done,
8119 * and indeed OpenSSH feels this is more polite than sending a
8120 * DISCONNECT. So now we don't.
8122 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
8126 void ssh_sharing_downstream_connected(Ssh ssh, unsigned id,
8127 const char *peerinfo)
8130 logeventf(ssh, "Connection sharing downstream #%u connected from %s",
8133 logeventf(ssh, "Connection sharing downstream #%u connected", id);
8136 void ssh_sharing_downstream_disconnected(Ssh ssh, unsigned id)
8138 logeventf(ssh, "Connection sharing downstream #%u disconnected", id);
8139 ssh_check_termination(ssh);
8142 void ssh_sharing_logf(Ssh ssh, unsigned id, const char *logfmt, ...)
8147 va_start(ap, logfmt);
8148 buf = dupvprintf(logfmt, ap);
8151 logeventf(ssh, "Connection sharing downstream #%u: %s", id, buf);
8153 logeventf(ssh, "Connection sharing: %s", buf);
8157 static void ssh_channel_destroy(struct ssh_channel *c)
8162 case CHAN_MAINSESSION:
8163 ssh->mainchan = NULL;
8164 update_specials_menu(ssh->frontend);
8167 if (c->u.x11.xconn != NULL)
8168 x11_close(c->u.x11.xconn);
8169 logevent("Forwarded X11 connection terminated");
8172 sfree(c->u.a.message);
8175 if (c->u.pfd.pf != NULL)
8176 pfd_close(c->u.pfd.pf);
8177 logevent("Forwarded port closed");
8181 del234(ssh->channels, c);
8182 if (ssh->version == 2) {
8183 bufchain_clear(&c->v.v2.outbuffer);
8184 assert(c->v.v2.chanreq_head == NULL);
8189 * If that was the last channel left open, we might need to
8192 ssh_check_termination(ssh);
8195 static void ssh2_channel_check_close(struct ssh_channel *c)
8198 struct Packet *pktout;
8202 * If we've sent out our own CHANNEL_OPEN but not yet seen
8203 * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
8204 * it's too early to be sending close messages of any kind.
8209 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
8210 c->type == CHAN_ZOMBIE) &&
8211 !c->v.v2.chanreq_head &&
8212 !(c->closes & CLOSES_SENT_CLOSE)) {
8214 * We have both sent and received EOF (or the channel is a
8215 * zombie), and we have no outstanding channel requests, which
8216 * means the channel is in final wind-up. But we haven't sent
8217 * CLOSE, so let's do so now.
8219 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
8220 ssh2_pkt_adduint32(pktout, c->remoteid);
8221 ssh2_pkt_send(ssh, pktout);
8222 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
8225 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
8226 assert(c->v.v2.chanreq_head == NULL);
8228 * We have both sent and received CLOSE, which means we're
8229 * completely done with the channel.
8231 ssh_channel_destroy(c);
8235 static void ssh2_channel_got_eof(struct ssh_channel *c)
8237 if (c->closes & CLOSES_RCVD_EOF)
8238 return; /* already seen EOF */
8239 c->closes |= CLOSES_RCVD_EOF;
8241 if (c->type == CHAN_X11) {
8242 x11_send_eof(c->u.x11.xconn);
8243 } else if (c->type == CHAN_AGENT) {
8244 if (c->u.a.outstanding_requests == 0) {
8245 /* Manufacture an outgoing EOF in response to the incoming one. */
8246 sshfwd_write_eof(c);
8248 } else if (c->type == CHAN_SOCKDATA) {
8249 pfd_send_eof(c->u.pfd.pf);
8250 } else if (c->type == CHAN_MAINSESSION) {
8253 if (!ssh->sent_console_eof &&
8254 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
8256 * Either from_backend_eof told us that the front end
8257 * wants us to close the outgoing side of the connection
8258 * as soon as we see EOF from the far end, or else we've
8259 * unilaterally decided to do that because we've allocated
8260 * a remote pty and hence EOF isn't a particularly
8261 * meaningful concept.
8263 sshfwd_write_eof(c);
8265 ssh->sent_console_eof = TRUE;
8268 ssh2_channel_check_close(c);
8271 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
8273 struct ssh_channel *c;
8275 c = ssh2_channel_msg(ssh, pktin);
8278 if (c->type == CHAN_SHARING) {
8279 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8280 pktin->body, pktin->length);
8283 ssh2_channel_got_eof(c);
8286 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
8288 struct ssh_channel *c;
8290 c = ssh2_channel_msg(ssh, pktin);
8293 if (c->type == CHAN_SHARING) {
8294 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8295 pktin->body, pktin->length);
8300 * When we receive CLOSE on a channel, we assume it comes with an
8301 * implied EOF if we haven't seen EOF yet.
8303 ssh2_channel_got_eof(c);
8305 if (!(ssh->remote_bugs & BUG_SENDS_LATE_REQUEST_REPLY)) {
8307 * It also means we stop expecting to see replies to any
8308 * outstanding channel requests, so clean those up too.
8309 * (ssh_chanreq_init will enforce by assertion that we don't
8310 * subsequently put anything back on this list.)
8312 while (c->v.v2.chanreq_head) {
8313 struct outstanding_channel_request *ocr = c->v.v2.chanreq_head;
8314 ocr->handler(c, NULL, ocr->ctx);
8315 c->v.v2.chanreq_head = ocr->next;
8321 * And we also send an outgoing EOF, if we haven't already, on the
8322 * assumption that CLOSE is a pretty forceful announcement that
8323 * the remote side is doing away with the entire channel. (If it
8324 * had wanted to send us EOF and continue receiving data from us,
8325 * it would have just sent CHANNEL_EOF.)
8327 if (!(c->closes & CLOSES_SENT_EOF)) {
8329 * Make sure we don't read any more from whatever our local
8330 * data source is for this channel.
8333 case CHAN_MAINSESSION:
8334 ssh->send_ok = 0; /* stop trying to read from stdin */
8337 x11_override_throttle(c->u.x11.xconn, 1);
8340 pfd_override_throttle(c->u.pfd.pf, 1);
8345 * Abandon any buffered data we still wanted to send to this
8346 * channel. Receiving a CHANNEL_CLOSE is an indication that
8347 * the server really wants to get on and _destroy_ this
8348 * channel, and it isn't going to send us any further
8349 * WINDOW_ADJUSTs to permit us to send pending stuff.
8351 bufchain_clear(&c->v.v2.outbuffer);
8354 * Send outgoing EOF.
8356 sshfwd_write_eof(c);
8360 * Now process the actual close.
8362 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
8363 c->closes |= CLOSES_RCVD_CLOSE;
8364 ssh2_channel_check_close(c);
8368 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
8370 struct ssh_channel *c;
8372 c = ssh2_channel_msg(ssh, pktin);
8375 if (c->type == CHAN_SHARING) {
8376 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8377 pktin->body, pktin->length);
8380 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
8381 c->remoteid = ssh_pkt_getuint32(pktin);
8382 c->halfopen = FALSE;
8383 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8384 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
8386 if (c->type == CHAN_SOCKDATA_DORMANT) {
8387 c->type = CHAN_SOCKDATA;
8389 pfd_confirm(c->u.pfd.pf);
8390 } else if (c->type == CHAN_ZOMBIE) {
8392 * This case can occur if a local socket error occurred
8393 * between us sending out CHANNEL_OPEN and receiving
8394 * OPEN_CONFIRMATION. In this case, all we can do is
8395 * immediately initiate close proceedings now that we know the
8396 * server's id to put in the close message.
8398 ssh2_channel_check_close(c);
8401 * We never expect to receive OPEN_CONFIRMATION for any
8402 * *other* channel type (since only local-to-remote port
8403 * forwardings cause us to send CHANNEL_OPEN after the main
8404 * channel is live - all other auxiliary channel types are
8405 * initiated from the server end). It's safe to enforce this
8406 * by assertion rather than by ssh_disconnect, because the
8407 * real point is that we never constructed a half-open channel
8408 * structure in the first place with any type other than the
8411 assert(!"Funny channel type in ssh2_msg_channel_open_confirmation");
8415 ssh_channel_try_eof(c); /* in case we had a pending EOF */
8418 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
8420 static const char *const reasons[] = {
8421 "<unknown reason code>",
8422 "Administratively prohibited",
8424 "Unknown channel type",
8425 "Resource shortage",
8427 unsigned reason_code;
8428 char *reason_string;
8430 struct ssh_channel *c;
8432 c = ssh2_channel_msg(ssh, pktin);
8435 if (c->type == CHAN_SHARING) {
8436 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8437 pktin->body, pktin->length);
8440 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
8442 if (c->type == CHAN_SOCKDATA_DORMANT) {
8443 reason_code = ssh_pkt_getuint32(pktin);
8444 if (reason_code >= lenof(reasons))
8445 reason_code = 0; /* ensure reasons[reason_code] in range */
8446 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
8447 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
8448 reasons[reason_code], reason_length,
8449 NULLTOEMPTY(reason_string));
8451 pfd_close(c->u.pfd.pf);
8452 } else if (c->type == CHAN_ZOMBIE) {
8454 * This case can occur if a local socket error occurred
8455 * between us sending out CHANNEL_OPEN and receiving
8456 * OPEN_FAILURE. In this case, we need do nothing except allow
8457 * the code below to throw the half-open channel away.
8461 * We never expect to receive OPEN_FAILURE for any *other*
8462 * channel type (since only local-to-remote port forwardings
8463 * cause us to send CHANNEL_OPEN after the main channel is
8464 * live - all other auxiliary channel types are initiated from
8465 * the server end). It's safe to enforce this by assertion
8466 * rather than by ssh_disconnect, because the real point is
8467 * that we never constructed a half-open channel structure in
8468 * the first place with any type other than the above.
8470 assert(!"Funny channel type in ssh2_msg_channel_open_failure");
8473 del234(ssh->channels, c);
8477 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
8480 int typelen, want_reply;
8481 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
8482 struct ssh_channel *c;
8483 struct Packet *pktout;
8485 c = ssh2_channel_msg(ssh, pktin);
8488 if (c->type == CHAN_SHARING) {
8489 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8490 pktin->body, pktin->length);
8493 ssh_pkt_getstring(pktin, &type, &typelen);
8494 want_reply = ssh2_pkt_getbool(pktin);
8496 if (c->closes & CLOSES_SENT_CLOSE) {
8498 * We don't reply to channel requests after we've sent
8499 * CHANNEL_CLOSE for the channel, because our reply might
8500 * cross in the network with the other side's CHANNEL_CLOSE
8501 * and arrive after they have wound the channel up completely.
8507 * Having got the channel number, we now look at
8508 * the request type string to see if it's something
8511 if (c == ssh->mainchan) {
8513 * We recognise "exit-status" and "exit-signal" on
8514 * the primary channel.
8516 if (typelen == 11 &&
8517 !memcmp(type, "exit-status", 11)) {
8519 ssh->exitcode = ssh_pkt_getuint32(pktin);
8520 logeventf(ssh, "Server sent command exit status %d",
8522 reply = SSH2_MSG_CHANNEL_SUCCESS;
8524 } else if (typelen == 11 &&
8525 !memcmp(type, "exit-signal", 11)) {
8527 int is_plausible = TRUE, is_int = FALSE;
8528 char *fmt_sig = NULL, *fmt_msg = NULL;
8530 int msglen = 0, core = FALSE;
8531 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
8532 * provide an `int' for the signal, despite its
8533 * having been a `string' in the drafts of RFC 4254 since at
8534 * least 2001. (Fixed in session.c 1.147.) Try to
8535 * infer which we can safely parse it as. */
8537 unsigned char *p = pktin->body +
8539 long len = pktin->length - pktin->savedpos;
8540 unsigned long num = GET_32BIT(p); /* what is it? */
8541 /* If it's 0, it hardly matters; assume string */
8545 int maybe_int = FALSE, maybe_str = FALSE;
8546 #define CHECK_HYPOTHESIS(offset, result) \
8549 int q = toint(offset); \
8550 if (q >= 0 && q+4 <= len) { \
8551 q = toint(q + 4 + GET_32BIT(p+q)); \
8552 if (q >= 0 && q+4 <= len && \
8553 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
8558 CHECK_HYPOTHESIS(4+1, maybe_int);
8559 CHECK_HYPOTHESIS(4+num+1, maybe_str);
8560 #undef CHECK_HYPOTHESIS
8561 if (maybe_int && !maybe_str)
8563 else if (!maybe_int && maybe_str)
8566 /* Crikey. Either or neither. Panic. */
8567 is_plausible = FALSE;
8570 ssh->exitcode = 128; /* means `unknown signal' */
8573 /* Old non-standard OpenSSH. */
8574 int signum = ssh_pkt_getuint32(pktin);
8575 fmt_sig = dupprintf(" %d", signum);
8576 ssh->exitcode = 128 + signum;
8578 /* As per RFC 4254. */
8581 ssh_pkt_getstring(pktin, &sig, &siglen);
8582 /* Signal name isn't supposed to be blank, but
8583 * let's cope gracefully if it is. */
8585 fmt_sig = dupprintf(" \"%.*s\"",
8590 * Really hideous method of translating the
8591 * signal description back into a locally
8592 * meaningful number.
8597 #define TRANSLATE_SIGNAL(s) \
8598 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
8599 ssh->exitcode = 128 + SIG ## s
8601 TRANSLATE_SIGNAL(ABRT);
8604 TRANSLATE_SIGNAL(ALRM);
8607 TRANSLATE_SIGNAL(FPE);
8610 TRANSLATE_SIGNAL(HUP);
8613 TRANSLATE_SIGNAL(ILL);
8616 TRANSLATE_SIGNAL(INT);
8619 TRANSLATE_SIGNAL(KILL);
8622 TRANSLATE_SIGNAL(PIPE);
8625 TRANSLATE_SIGNAL(QUIT);
8628 TRANSLATE_SIGNAL(SEGV);
8631 TRANSLATE_SIGNAL(TERM);
8634 TRANSLATE_SIGNAL(USR1);
8637 TRANSLATE_SIGNAL(USR2);
8639 #undef TRANSLATE_SIGNAL
8641 ssh->exitcode = 128;
8643 core = ssh2_pkt_getbool(pktin);
8644 ssh_pkt_getstring(pktin, &msg, &msglen);
8646 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
8648 /* ignore lang tag */
8649 } /* else don't attempt to parse */
8650 logeventf(ssh, "Server exited on signal%s%s%s",
8651 fmt_sig ? fmt_sig : "",
8652 core ? " (core dumped)" : "",
8653 fmt_msg ? fmt_msg : "");
8656 reply = SSH2_MSG_CHANNEL_SUCCESS;
8661 * This is a channel request we don't know
8662 * about, so we now either ignore the request
8663 * or respond with CHANNEL_FAILURE, depending
8666 reply = SSH2_MSG_CHANNEL_FAILURE;
8669 pktout = ssh2_pkt_init(reply);
8670 ssh2_pkt_adduint32(pktout, c->remoteid);
8671 ssh2_pkt_send(ssh, pktout);
8675 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
8678 int typelen, want_reply;
8679 struct Packet *pktout;
8681 ssh_pkt_getstring(pktin, &type, &typelen);
8682 want_reply = ssh2_pkt_getbool(pktin);
8685 * We currently don't support any global requests
8686 * at all, so we either ignore the request or
8687 * respond with REQUEST_FAILURE, depending on
8691 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
8692 ssh2_pkt_send(ssh, pktout);
8696 struct X11FakeAuth *ssh_sharing_add_x11_display(Ssh ssh, int authtype,
8700 struct X11FakeAuth *auth;
8703 * Make up a new set of fake X11 auth data, and add it to the tree
8704 * of currently valid ones with an indication of the sharing
8705 * context that it's relevant to.
8707 auth = x11_invent_fake_auth(ssh->x11authtree, authtype);
8708 auth->share_cs = share_cs;
8709 auth->share_chan = share_chan;
8714 void ssh_sharing_remove_x11_display(Ssh ssh, struct X11FakeAuth *auth)
8716 del234(ssh->x11authtree, auth);
8717 x11_free_fake_auth(auth);
8720 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
8727 const char *error = NULL;
8728 struct ssh_channel *c;
8729 unsigned remid, winsize, pktsize;
8730 unsigned our_winsize_override = 0;
8731 struct Packet *pktout;
8733 ssh_pkt_getstring(pktin, &type, &typelen);
8734 c = snew(struct ssh_channel);
8737 remid = ssh_pkt_getuint32(pktin);
8738 winsize = ssh_pkt_getuint32(pktin);
8739 pktsize = ssh_pkt_getuint32(pktin);
8741 if (typelen == 3 && !memcmp(type, "x11", 3)) {
8744 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8745 addrstr = dupprintf("%.*s", peeraddrlen, NULLTOEMPTY(peeraddr));
8746 peerport = ssh_pkt_getuint32(pktin);
8748 logeventf(ssh, "Received X11 connect request from %s:%d",
8751 if (!ssh->X11_fwd_enabled && !ssh->connshare)
8752 error = "X11 forwarding is not enabled";
8754 c->u.x11.xconn = x11_init(ssh->x11authtree, c,
8757 c->u.x11.initial = TRUE;
8760 * If we are a connection-sharing upstream, then we should
8761 * initially present a very small window, adequate to take
8762 * the X11 initial authorisation packet but not much more.
8763 * Downstream will then present us a larger window (by
8764 * fiat of the connection-sharing protocol) and we can
8765 * guarantee to send a positive-valued WINDOW_ADJUST.
8768 our_winsize_override = 128;
8770 logevent("Opened X11 forward channel");
8774 } else if (typelen == 15 &&
8775 !memcmp(type, "forwarded-tcpip", 15)) {
8776 struct ssh_rportfwd pf, *realpf;
8779 ssh_pkt_getstring(pktin, &shost, &shostlen);/* skip address */
8780 pf.shost = dupprintf("%.*s", shostlen, NULLTOEMPTY(shost));
8781 pf.sport = ssh_pkt_getuint32(pktin);
8782 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8783 peerport = ssh_pkt_getuint32(pktin);
8784 realpf = find234(ssh->rportfwds, &pf, NULL);
8785 logeventf(ssh, "Received remote port %s:%d open request "
8786 "from %.*s:%d", pf.shost, pf.sport,
8787 peeraddrlen, NULLTOEMPTY(peeraddr), peerport);
8790 if (realpf == NULL) {
8791 error = "Remote port is not recognised";
8795 if (realpf->share_ctx) {
8797 * This port forwarding is on behalf of a
8798 * connection-sharing downstream, so abandon our own
8799 * channel-open procedure and just pass the message on
8802 share_got_pkt_from_server(realpf->share_ctx, pktin->type,
8803 pktin->body, pktin->length);
8808 err = pfd_connect(&c->u.pfd.pf, realpf->dhost, realpf->dport,
8809 c, ssh->conf, realpf->pfrec->addressfamily);
8810 logeventf(ssh, "Attempting to forward remote port to "
8811 "%s:%d", realpf->dhost, realpf->dport);
8813 logeventf(ssh, "Port open failed: %s", err);
8815 error = "Port open failed";
8817 logevent("Forwarded port opened successfully");
8818 c->type = CHAN_SOCKDATA;
8821 } else if (typelen == 22 &&
8822 !memcmp(type, "auth-agent@openssh.com", 22)) {
8823 if (!ssh->agentfwd_enabled)
8824 error = "Agent forwarding is not enabled";
8826 c->type = CHAN_AGENT; /* identify channel type */
8827 c->u.a.lensofar = 0;
8828 c->u.a.message = NULL;
8829 c->u.a.outstanding_requests = 0;
8832 error = "Unsupported channel type requested";
8835 c->remoteid = remid;
8836 c->halfopen = FALSE;
8838 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
8839 ssh2_pkt_adduint32(pktout, c->remoteid);
8840 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
8841 ssh2_pkt_addstring(pktout, error);
8842 ssh2_pkt_addstring(pktout, "en"); /* language tag */
8843 ssh2_pkt_send(ssh, pktout);
8844 logeventf(ssh, "Rejected channel open: %s", error);
8847 ssh2_channel_init(c);
8848 c->v.v2.remwindow = winsize;
8849 c->v.v2.remmaxpkt = pktsize;
8850 if (our_winsize_override) {
8851 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
8852 our_winsize_override;
8854 add234(ssh->channels, c);
8855 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
8856 ssh2_pkt_adduint32(pktout, c->remoteid);
8857 ssh2_pkt_adduint32(pktout, c->localid);
8858 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
8859 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8860 ssh2_pkt_send(ssh, pktout);
8864 void sshfwd_x11_sharing_handover(struct ssh_channel *c,
8865 void *share_cs, void *share_chan,
8866 const char *peer_addr, int peer_port,
8867 int endian, int protomajor, int protominor,
8868 const void *initial_data, int initial_len)
8871 * This function is called when we've just discovered that an X
8872 * forwarding channel on which we'd been handling the initial auth
8873 * ourselves turns out to be destined for a connection-sharing
8874 * downstream. So we turn the channel into a CHAN_SHARING, meaning
8875 * that we completely stop tracking windows and buffering data and
8876 * just pass more or less unmodified SSH messages back and forth.
8878 c->type = CHAN_SHARING;
8879 c->u.sharing.ctx = share_cs;
8880 share_setup_x11_channel(share_cs, share_chan,
8881 c->localid, c->remoteid, c->v.v2.remwindow,
8882 c->v.v2.remmaxpkt, c->v.v2.locwindow,
8883 peer_addr, peer_port, endian,
8884 protomajor, protominor,
8885 initial_data, initial_len);
8888 void sshfwd_x11_is_local(struct ssh_channel *c)
8891 * This function is called when we've just discovered that an X
8892 * forwarding channel is _not_ destined for a connection-sharing
8893 * downstream but we're going to handle it ourselves. We stop
8894 * presenting a cautiously small window and go into ordinary data
8897 c->u.x11.initial = FALSE;
8898 ssh2_set_window(c, ssh_is_simple(c->ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE);
8902 * Buffer banner messages for later display at some convenient point,
8903 * if we're going to display them.
8905 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
8907 /* Arbitrary limit to prevent unbounded inflation of buffer */
8908 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
8909 bufchain_size(&ssh->banner) <= 131072) {
8910 char *banner = NULL;
8912 ssh_pkt_getstring(pktin, &banner, &size);
8914 bufchain_add(&ssh->banner, banner, size);
8918 /* Helper function to deal with sending tty modes for "pty-req" */
8919 static void ssh2_send_ttymode(void *data, char *mode, char *val)
8921 struct Packet *pktout = (struct Packet *)data;
8923 unsigned int arg = 0;
8924 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
8925 if (i == lenof(ssh_ttymodes)) return;
8926 switch (ssh_ttymodes[i].type) {
8928 arg = ssh_tty_parse_specchar(val);
8931 arg = ssh_tty_parse_boolean(val);
8934 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
8935 ssh2_pkt_adduint32(pktout, arg);
8938 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
8941 struct ssh2_setup_x11_state {
8945 struct Packet *pktout;
8946 crStateP(ssh2_setup_x11_state, ctx);
8950 logevent("Requesting X11 forwarding");
8951 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
8953 ssh2_pkt_addbool(pktout, 0); /* many connections */
8954 ssh2_pkt_addstring(pktout, ssh->x11auth->protoname);
8955 ssh2_pkt_addstring(pktout, ssh->x11auth->datastring);
8956 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
8957 ssh2_pkt_send(ssh, pktout);
8959 /* Wait to be called back with either a response packet, or NULL
8960 * meaning clean up and free our data */
8964 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8965 logevent("X11 forwarding enabled");
8966 ssh->X11_fwd_enabled = TRUE;
8968 logevent("X11 forwarding refused");
8974 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
8977 struct ssh2_setup_agent_state {
8981 struct Packet *pktout;
8982 crStateP(ssh2_setup_agent_state, ctx);
8986 logevent("Requesting OpenSSH-style agent forwarding");
8987 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
8988 ssh2_setup_agent, s);
8989 ssh2_pkt_send(ssh, pktout);
8991 /* Wait to be called back with either a response packet, or NULL
8992 * meaning clean up and free our data */
8996 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8997 logevent("Agent forwarding enabled");
8998 ssh->agentfwd_enabled = TRUE;
9000 logevent("Agent forwarding refused");
9006 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
9009 struct ssh2_setup_pty_state {
9013 struct Packet *pktout;
9014 crStateP(ssh2_setup_pty_state, ctx);
9018 /* Unpick the terminal-speed string. */
9019 /* XXX perhaps we should allow no speeds to be sent. */
9020 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
9021 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
9022 /* Build the pty request. */
9023 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
9025 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
9026 ssh2_pkt_adduint32(pktout, ssh->term_width);
9027 ssh2_pkt_adduint32(pktout, ssh->term_height);
9028 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
9029 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
9030 ssh2_pkt_addstring_start(pktout);
9031 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
9032 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
9033 ssh2_pkt_adduint32(pktout, ssh->ispeed);
9034 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
9035 ssh2_pkt_adduint32(pktout, ssh->ospeed);
9036 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
9037 ssh2_pkt_send(ssh, pktout);
9038 ssh->state = SSH_STATE_INTERMED;
9040 /* Wait to be called back with either a response packet, or NULL
9041 * meaning clean up and free our data */
9045 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
9046 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
9047 ssh->ospeed, ssh->ispeed);
9048 ssh->got_pty = TRUE;
9050 c_write_str(ssh, "Server refused to allocate pty\r\n");
9051 ssh->editing = ssh->echoing = 1;
9058 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
9061 struct ssh2_setup_env_state {
9063 int num_env, env_left, env_ok;
9066 struct Packet *pktout;
9067 crStateP(ssh2_setup_env_state, ctx);
9072 * Send environment variables.
9074 * Simplest thing here is to send all the requests at once, and
9075 * then wait for a whole bunch of successes or failures.
9081 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
9083 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
9084 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
9085 ssh2_pkt_addstring(pktout, key);
9086 ssh2_pkt_addstring(pktout, val);
9087 ssh2_pkt_send(ssh, pktout);
9092 logeventf(ssh, "Sent %d environment variables", s->num_env);
9097 s->env_left = s->num_env;
9099 while (s->env_left > 0) {
9100 /* Wait to be called back with either a response packet,
9101 * or NULL meaning clean up and free our data */
9103 if (!pktin) goto out;
9104 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
9109 if (s->env_ok == s->num_env) {
9110 logevent("All environment variables successfully set");
9111 } else if (s->env_ok == 0) {
9112 logevent("All environment variables refused");
9113 c_write_str(ssh, "Server refused to set environment variables\r\n");
9115 logeventf(ssh, "%d environment variables refused",
9116 s->num_env - s->env_ok);
9117 c_write_str(ssh, "Server refused to set all environment variables\r\n");
9125 * Handle the SSH-2 userauth and connection layers.
9127 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
9129 do_ssh2_authconn(ssh, NULL, 0, pktin);
9132 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
9136 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
9139 static void do_ssh2_authconn(Ssh ssh, const unsigned char *in, int inlen,
9140 struct Packet *pktin)
9142 struct do_ssh2_authconn_state {
9146 AUTH_TYPE_PUBLICKEY,
9147 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
9148 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
9150 AUTH_TYPE_GSSAPI, /* always QUIET */
9151 AUTH_TYPE_KEYBOARD_INTERACTIVE,
9152 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
9154 int done_service_req;
9155 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
9156 int tried_pubkey_config, done_agent;
9161 int kbd_inter_refused;
9162 int we_are_in, userauth_success;
9163 prompts_t *cur_prompt;
9168 void *publickey_blob;
9169 int publickey_bloblen;
9170 int privatekey_available, privatekey_encrypted;
9171 char *publickey_algorithm;
9172 char *publickey_comment;
9173 unsigned char agent_request[5], *agent_response, *agentp;
9174 int agent_responselen;
9175 unsigned char *pkblob_in_agent;
9177 char *pkblob, *alg, *commentp;
9178 int pklen, alglen, commentlen;
9179 int siglen, retlen, len;
9180 char *q, *agentreq, *ret;
9182 struct Packet *pktout;
9185 struct ssh_gss_library *gsslib;
9186 Ssh_gss_ctx gss_ctx;
9187 Ssh_gss_buf gss_buf;
9188 Ssh_gss_buf gss_rcvtok, gss_sndtok;
9189 Ssh_gss_name gss_srv_name;
9190 Ssh_gss_stat gss_stat;
9193 crState(do_ssh2_authconn_state);
9197 /* Register as a handler for all the messages this coroutine handles. */
9198 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
9199 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
9200 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
9201 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
9202 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
9203 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
9204 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
9205 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
9206 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
9207 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
9208 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
9209 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
9210 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
9211 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
9212 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
9213 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
9214 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
9215 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
9216 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
9217 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
9219 s->done_service_req = FALSE;
9220 s->we_are_in = s->userauth_success = FALSE;
9221 s->agent_response = NULL;
9223 s->tried_gssapi = FALSE;
9226 if (!ssh->bare_connection) {
9227 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
9229 * Request userauth protocol, and await a response to it.
9231 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
9232 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
9233 ssh2_pkt_send(ssh, s->pktout);
9234 crWaitUntilV(pktin);
9235 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
9236 s->done_service_req = TRUE;
9238 if (!s->done_service_req) {
9240 * Request connection protocol directly, without authentication.
9242 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
9243 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9244 ssh2_pkt_send(ssh, s->pktout);
9245 crWaitUntilV(pktin);
9246 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
9247 s->we_are_in = TRUE; /* no auth required */
9249 bombout(("Server refused service request"));
9254 s->we_are_in = TRUE;
9257 /* Arrange to be able to deal with any BANNERs that come in.
9258 * (We do this now as packets may come in during the next bit.) */
9259 bufchain_init(&ssh->banner);
9260 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
9261 ssh2_msg_userauth_banner;
9264 * Misc one-time setup for authentication.
9266 s->publickey_blob = NULL;
9267 if (!s->we_are_in) {
9270 * Load the public half of any configured public key file
9273 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9274 if (!filename_is_null(s->keyfile)) {
9276 logeventf(ssh, "Reading key file \"%.150s\"",
9277 filename_to_str(s->keyfile));
9278 keytype = key_type(s->keyfile);
9279 if (keytype == SSH_KEYTYPE_SSH2 ||
9280 keytype == SSH_KEYTYPE_SSH2_PUBLIC_RFC4716 ||
9281 keytype == SSH_KEYTYPE_SSH2_PUBLIC_OPENSSH) {
9284 ssh2_userkey_loadpub(s->keyfile,
9285 &s->publickey_algorithm,
9286 &s->publickey_bloblen,
9287 &s->publickey_comment, &error);
9288 if (s->publickey_blob) {
9289 s->privatekey_available = (keytype == SSH_KEYTYPE_SSH2);
9290 if (!s->privatekey_available)
9291 logeventf(ssh, "Key file contains public key only");
9292 s->privatekey_encrypted =
9293 ssh2_userkey_encrypted(s->keyfile, NULL);
9296 logeventf(ssh, "Unable to load key (%s)",
9298 msgbuf = dupprintf("Unable to load key file "
9299 "\"%.150s\" (%s)\r\n",
9300 filename_to_str(s->keyfile),
9302 c_write_str(ssh, msgbuf);
9307 logeventf(ssh, "Unable to use this key file (%s)",
9308 key_type_to_str(keytype));
9309 msgbuf = dupprintf("Unable to use key file \"%.150s\""
9311 filename_to_str(s->keyfile),
9312 key_type_to_str(keytype));
9313 c_write_str(ssh, msgbuf);
9315 s->publickey_blob = NULL;
9320 * Find out about any keys Pageant has (but if there's a
9321 * public key configured, filter out all others).
9324 s->agent_response = NULL;
9325 s->pkblob_in_agent = NULL;
9326 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
9330 logevent("Pageant is running. Requesting keys.");
9332 /* Request the keys held by the agent. */
9333 PUT_32BIT(s->agent_request, 1);
9334 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
9335 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
9336 ssh_agent_callback, ssh)) {
9340 bombout(("Unexpected data from server while"
9341 " waiting for agent response"));
9344 } while (pktin || inlen > 0);
9345 r = ssh->agent_response;
9346 s->agent_responselen = ssh->agent_response_len;
9348 s->agent_response = (unsigned char *) r;
9349 if (s->agent_response && s->agent_responselen >= 5 &&
9350 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
9353 p = s->agent_response + 5;
9354 s->nkeys = toint(GET_32BIT(p));
9357 * Vet the Pageant response to ensure that the key
9358 * count and blob lengths make sense.
9361 logeventf(ssh, "Pageant response contained a negative"
9362 " key count %d", s->nkeys);
9364 goto done_agent_query;
9366 unsigned char *q = p + 4;
9367 int lenleft = s->agent_responselen - 5 - 4;
9369 for (keyi = 0; keyi < s->nkeys; keyi++) {
9370 int bloblen, commentlen;
9372 logeventf(ssh, "Pageant response was truncated");
9374 goto done_agent_query;
9376 bloblen = toint(GET_32BIT(q));
9377 if (bloblen < 0 || bloblen > lenleft) {
9378 logeventf(ssh, "Pageant response was truncated");
9380 goto done_agent_query;
9382 lenleft -= 4 + bloblen;
9384 commentlen = toint(GET_32BIT(q));
9385 if (commentlen < 0 || commentlen > lenleft) {
9386 logeventf(ssh, "Pageant response was truncated");
9388 goto done_agent_query;
9390 lenleft -= 4 + commentlen;
9391 q += 4 + commentlen;
9396 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
9397 if (s->publickey_blob) {
9398 /* See if configured key is in agent. */
9399 for (keyi = 0; keyi < s->nkeys; keyi++) {
9400 s->pklen = toint(GET_32BIT(p));
9401 if (s->pklen == s->publickey_bloblen &&
9402 !memcmp(p+4, s->publickey_blob,
9403 s->publickey_bloblen)) {
9404 logeventf(ssh, "Pageant key #%d matches "
9405 "configured key file", keyi);
9407 s->pkblob_in_agent = p;
9411 p += toint(GET_32BIT(p)) + 4; /* comment */
9413 if (!s->pkblob_in_agent) {
9414 logevent("Configured key file not in Pageant");
9419 logevent("Failed to get reply from Pageant");
9427 * We repeat this whole loop, including the username prompt,
9428 * until we manage a successful authentication. If the user
9429 * types the wrong _password_, they can be sent back to the
9430 * beginning to try another username, if this is configured on.
9431 * (If they specify a username in the config, they are never
9432 * asked, even if they do give a wrong password.)
9434 * I think this best serves the needs of
9436 * - the people who have no configuration, no keys, and just
9437 * want to try repeated (username,password) pairs until they
9438 * type both correctly
9440 * - people who have keys and configuration but occasionally
9441 * need to fall back to passwords
9443 * - people with a key held in Pageant, who might not have
9444 * logged in to a particular machine before; so they want to
9445 * type a username, and then _either_ their key will be
9446 * accepted, _or_ they will type a password. If they mistype
9447 * the username they will want to be able to get back and
9450 s->got_username = FALSE;
9451 while (!s->we_are_in) {
9455 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
9457 * We got a username last time round this loop, and
9458 * with change_username turned off we don't try to get
9461 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
9462 int ret; /* need not be kept over crReturn */
9463 s->cur_prompt = new_prompts(ssh->frontend);
9464 s->cur_prompt->to_server = TRUE;
9465 s->cur_prompt->name = dupstr("SSH login name");
9466 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
9467 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9470 crWaitUntilV(!pktin);
9471 ret = get_userpass_input(s->cur_prompt, in, inlen);
9476 * get_userpass_input() failed to get a username.
9479 free_prompts(s->cur_prompt);
9480 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
9483 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
9484 free_prompts(s->cur_prompt);
9487 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
9488 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
9489 c_write_str(ssh, stuff);
9493 s->got_username = TRUE;
9496 * Send an authentication request using method "none": (a)
9497 * just in case it succeeds, and (b) so that we know what
9498 * authentication methods we can usefully try next.
9500 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9502 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9503 ssh2_pkt_addstring(s->pktout, ssh->username);
9504 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
9505 ssh2_pkt_addstring(s->pktout, "none"); /* method */
9506 ssh2_pkt_send(ssh, s->pktout);
9507 s->type = AUTH_TYPE_NONE;
9509 s->we_are_in = FALSE;
9511 s->tried_pubkey_config = FALSE;
9512 s->kbd_inter_refused = FALSE;
9514 /* Reset agent request state. */
9515 s->done_agent = FALSE;
9516 if (s->agent_response) {
9517 if (s->pkblob_in_agent) {
9518 s->agentp = s->pkblob_in_agent;
9520 s->agentp = s->agent_response + 5 + 4;
9526 char *methods = NULL;
9530 * Wait for the result of the last authentication request.
9533 crWaitUntilV(pktin);
9535 * Now is a convenient point to spew any banner material
9536 * that we've accumulated. (This should ensure that when
9537 * we exit the auth loop, we haven't any left to deal
9541 int size = bufchain_size(&ssh->banner);
9543 * Don't show the banner if we're operating in
9544 * non-verbose non-interactive mode. (It's probably
9545 * a script, which means nobody will read the
9546 * banner _anyway_, and moreover the printing of
9547 * the banner will screw up processing on the
9548 * output of (say) plink.)
9550 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
9551 char *banner = snewn(size, char);
9552 bufchain_fetch(&ssh->banner, banner, size);
9553 c_write_untrusted(ssh, banner, size);
9556 bufchain_clear(&ssh->banner);
9558 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
9559 logevent("Access granted");
9560 s->we_are_in = s->userauth_success = TRUE;
9564 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
9565 bombout(("Strange packet received during authentication: "
9566 "type %d", pktin->type));
9573 * OK, we're now sitting on a USERAUTH_FAILURE message, so
9574 * we can look at the string in it and know what we can
9575 * helpfully try next.
9577 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
9578 ssh_pkt_getstring(pktin, &methods, &methlen);
9579 if (!ssh2_pkt_getbool(pktin)) {
9581 * We have received an unequivocal Access
9582 * Denied. This can translate to a variety of
9583 * messages, or no message at all.
9585 * For forms of authentication which are attempted
9586 * implicitly, by which I mean without printing
9587 * anything in the window indicating that we're
9588 * trying them, we should never print 'Access
9591 * If we do print a message saying that we're
9592 * attempting some kind of authentication, it's OK
9593 * to print a followup message saying it failed -
9594 * but the message may sometimes be more specific
9595 * than simply 'Access denied'.
9597 * Additionally, if we'd just tried password
9598 * authentication, we should break out of this
9599 * whole loop so as to go back to the username
9600 * prompt (iff we're configured to allow
9601 * username change attempts).
9603 if (s->type == AUTH_TYPE_NONE) {
9605 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
9606 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
9607 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
9608 c_write_str(ssh, "Server refused our key\r\n");
9609 logevent("Server refused our key");
9610 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
9611 /* This _shouldn't_ happen except by a
9612 * protocol bug causing client and server to
9613 * disagree on what is a correct signature. */
9614 c_write_str(ssh, "Server refused public-key signature"
9615 " despite accepting key!\r\n");
9616 logevent("Server refused public-key signature"
9617 " despite accepting key!");
9618 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
9619 /* quiet, so no c_write */
9620 logevent("Server refused keyboard-interactive authentication");
9621 } else if (s->type==AUTH_TYPE_GSSAPI) {
9622 /* always quiet, so no c_write */
9623 /* also, the code down in the GSSAPI block has
9624 * already logged this in the Event Log */
9625 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
9626 logevent("Keyboard-interactive authentication failed");
9627 c_write_str(ssh, "Access denied\r\n");
9629 assert(s->type == AUTH_TYPE_PASSWORD);
9630 logevent("Password authentication failed");
9631 c_write_str(ssh, "Access denied\r\n");
9633 if (conf_get_int(ssh->conf, CONF_change_username)) {
9634 /* XXX perhaps we should allow
9635 * keyboard-interactive to do this too? */
9636 s->we_are_in = FALSE;
9641 c_write_str(ssh, "Further authentication required\r\n");
9642 logevent("Further authentication required");
9646 in_commasep_string("publickey", methods, methlen);
9648 in_commasep_string("password", methods, methlen);
9649 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
9650 in_commasep_string("keyboard-interactive", methods, methlen);
9652 if (conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
9653 in_commasep_string("gssapi-with-mic", methods, methlen)) {
9654 /* Try loading the GSS libraries and see if we
9657 ssh->gsslibs = ssh_gss_setup(ssh->conf);
9658 s->can_gssapi = (ssh->gsslibs->nlibraries > 0);
9660 /* No point in even bothering to try to load the
9661 * GSS libraries, if the user configuration and
9662 * server aren't both prepared to attempt GSSAPI
9663 * auth in the first place. */
9664 s->can_gssapi = FALSE;
9669 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9671 if (s->can_pubkey && !s->done_agent && s->nkeys) {
9674 * Attempt public-key authentication using a key from Pageant.
9677 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9679 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
9681 /* Unpack key from agent response */
9682 s->pklen = toint(GET_32BIT(s->agentp));
9684 s->pkblob = (char *)s->agentp;
9685 s->agentp += s->pklen;
9686 s->alglen = toint(GET_32BIT(s->pkblob));
9687 s->alg = s->pkblob + 4;
9688 s->commentlen = toint(GET_32BIT(s->agentp));
9690 s->commentp = (char *)s->agentp;
9691 s->agentp += s->commentlen;
9692 /* s->agentp now points at next key, if any */
9694 /* See if server will accept it */
9695 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9696 ssh2_pkt_addstring(s->pktout, ssh->username);
9697 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9698 /* service requested */
9699 ssh2_pkt_addstring(s->pktout, "publickey");
9701 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
9702 ssh2_pkt_addstring_start(s->pktout);
9703 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9704 ssh2_pkt_addstring_start(s->pktout);
9705 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9706 ssh2_pkt_send(ssh, s->pktout);
9707 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
9709 crWaitUntilV(pktin);
9710 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9712 /* Offer of key refused. */
9719 if (flags & FLAG_VERBOSE) {
9720 c_write_str(ssh, "Authenticating with "
9722 c_write(ssh, s->commentp, s->commentlen);
9723 c_write_str(ssh, "\" from agent\r\n");
9727 * Server is willing to accept the key.
9728 * Construct a SIGN_REQUEST.
9730 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9731 ssh2_pkt_addstring(s->pktout, ssh->username);
9732 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9733 /* service requested */
9734 ssh2_pkt_addstring(s->pktout, "publickey");
9736 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
9737 ssh2_pkt_addstring_start(s->pktout);
9738 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9739 ssh2_pkt_addstring_start(s->pktout);
9740 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9742 /* Ask agent for signature. */
9743 s->siglen = s->pktout->length - 5 + 4 +
9744 ssh->v2_session_id_len;
9745 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9747 s->len = 1; /* message type */
9748 s->len += 4 + s->pklen; /* key blob */
9749 s->len += 4 + s->siglen; /* data to sign */
9750 s->len += 4; /* flags */
9751 s->agentreq = snewn(4 + s->len, char);
9752 PUT_32BIT(s->agentreq, s->len);
9753 s->q = s->agentreq + 4;
9754 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
9755 PUT_32BIT(s->q, s->pklen);
9757 memcpy(s->q, s->pkblob, s->pklen);
9759 PUT_32BIT(s->q, s->siglen);
9761 /* Now the data to be signed... */
9762 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9763 PUT_32BIT(s->q, ssh->v2_session_id_len);
9766 memcpy(s->q, ssh->v2_session_id,
9767 ssh->v2_session_id_len);
9768 s->q += ssh->v2_session_id_len;
9769 memcpy(s->q, s->pktout->data + 5,
9770 s->pktout->length - 5);
9771 s->q += s->pktout->length - 5;
9772 /* And finally the (zero) flags word. */
9774 if (!agent_query(s->agentreq, s->len + 4,
9776 ssh_agent_callback, ssh)) {
9780 bombout(("Unexpected data from server"
9781 " while waiting for agent"
9785 } while (pktin || inlen > 0);
9786 vret = ssh->agent_response;
9787 s->retlen = ssh->agent_response_len;
9792 if (s->retlen >= 9 &&
9793 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
9794 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
9795 logevent("Sending Pageant's response");
9796 ssh2_add_sigblob(ssh, s->pktout,
9797 s->pkblob, s->pklen,
9799 GET_32BIT(s->ret + 5));
9800 ssh2_pkt_send(ssh, s->pktout);
9801 s->type = AUTH_TYPE_PUBLICKEY;
9803 /* FIXME: less drastic response */
9804 bombout(("Pageant failed to answer challenge"));
9810 /* Do we have any keys left to try? */
9811 if (s->pkblob_in_agent) {
9812 s->done_agent = TRUE;
9813 s->tried_pubkey_config = TRUE;
9816 if (s->keyi >= s->nkeys)
9817 s->done_agent = TRUE;
9820 } else if (s->can_pubkey && s->publickey_blob &&
9821 s->privatekey_available && !s->tried_pubkey_config) {
9823 struct ssh2_userkey *key; /* not live over crReturn */
9824 char *passphrase; /* not live over crReturn */
9826 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9828 s->tried_pubkey_config = TRUE;
9831 * Try the public key supplied in the configuration.
9833 * First, offer the public blob to see if the server is
9834 * willing to accept it.
9836 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9837 ssh2_pkt_addstring(s->pktout, ssh->username);
9838 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9839 /* service requested */
9840 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
9841 ssh2_pkt_addbool(s->pktout, FALSE);
9842 /* no signature included */
9843 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
9844 ssh2_pkt_addstring_start(s->pktout);
9845 ssh2_pkt_addstring_data(s->pktout,
9846 (char *)s->publickey_blob,
9847 s->publickey_bloblen);
9848 ssh2_pkt_send(ssh, s->pktout);
9849 logevent("Offered public key");
9851 crWaitUntilV(pktin);
9852 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9853 /* Key refused. Give up. */
9854 s->gotit = TRUE; /* reconsider message next loop */
9855 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
9856 continue; /* process this new message */
9858 logevent("Offer of public key accepted");
9861 * Actually attempt a serious authentication using
9864 if (flags & FLAG_VERBOSE) {
9865 c_write_str(ssh, "Authenticating with public key \"");
9866 c_write_str(ssh, s->publickey_comment);
9867 c_write_str(ssh, "\"\r\n");
9871 const char *error; /* not live over crReturn */
9872 if (s->privatekey_encrypted) {
9874 * Get a passphrase from the user.
9876 int ret; /* need not be kept over crReturn */
9877 s->cur_prompt = new_prompts(ssh->frontend);
9878 s->cur_prompt->to_server = FALSE;
9879 s->cur_prompt->name = dupstr("SSH key passphrase");
9880 add_prompt(s->cur_prompt,
9881 dupprintf("Passphrase for key \"%.100s\": ",
9882 s->publickey_comment),
9884 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9887 crWaitUntilV(!pktin);
9888 ret = get_userpass_input(s->cur_prompt,
9893 /* Failed to get a passphrase. Terminate. */
9894 free_prompts(s->cur_prompt);
9895 ssh_disconnect(ssh, NULL,
9896 "Unable to authenticate",
9897 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9902 dupstr(s->cur_prompt->prompts[0]->result);
9903 free_prompts(s->cur_prompt);
9905 passphrase = NULL; /* no passphrase needed */
9909 * Try decrypting the key.
9911 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9912 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
9914 /* burn the evidence */
9915 smemclr(passphrase, strlen(passphrase));
9918 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
9920 (key == SSH2_WRONG_PASSPHRASE)) {
9921 c_write_str(ssh, "Wrong passphrase\r\n");
9923 /* and loop again */
9925 c_write_str(ssh, "Unable to load private key (");
9926 c_write_str(ssh, error);
9927 c_write_str(ssh, ")\r\n");
9929 break; /* try something else */
9935 unsigned char *pkblob, *sigblob, *sigdata;
9936 int pkblob_len, sigblob_len, sigdata_len;
9940 * We have loaded the private key and the server
9941 * has announced that it's willing to accept it.
9942 * Hallelujah. Generate a signature and send it.
9944 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9945 ssh2_pkt_addstring(s->pktout, ssh->username);
9946 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9947 /* service requested */
9948 ssh2_pkt_addstring(s->pktout, "publickey");
9950 ssh2_pkt_addbool(s->pktout, TRUE);
9951 /* signature follows */
9952 ssh2_pkt_addstring(s->pktout, key->alg->name);
9953 pkblob = key->alg->public_blob(key->data,
9955 ssh2_pkt_addstring_start(s->pktout);
9956 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
9960 * The data to be signed is:
9964 * followed by everything so far placed in the
9967 sigdata_len = s->pktout->length - 5 + 4 +
9968 ssh->v2_session_id_len;
9969 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9971 sigdata = snewn(sigdata_len, unsigned char);
9973 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9974 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
9977 memcpy(sigdata+p, ssh->v2_session_id,
9978 ssh->v2_session_id_len);
9979 p += ssh->v2_session_id_len;
9980 memcpy(sigdata+p, s->pktout->data + 5,
9981 s->pktout->length - 5);
9982 p += s->pktout->length - 5;
9983 assert(p == sigdata_len);
9984 sigblob = key->alg->sign(key->data, (char *)sigdata,
9985 sigdata_len, &sigblob_len);
9986 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
9987 sigblob, sigblob_len);
9992 ssh2_pkt_send(ssh, s->pktout);
9993 logevent("Sent public key signature");
9994 s->type = AUTH_TYPE_PUBLICKEY;
9995 key->alg->freekey(key->data);
9996 sfree(key->comment);
10001 } else if (s->can_gssapi && !s->tried_gssapi) {
10003 /* GSSAPI Authentication */
10005 int micoffset, len;
10008 s->type = AUTH_TYPE_GSSAPI;
10009 s->tried_gssapi = TRUE;
10011 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
10014 * Pick the highest GSS library on the preference
10020 for (i = 0; i < ngsslibs; i++) {
10021 int want_id = conf_get_int_int(ssh->conf,
10022 CONF_ssh_gsslist, i);
10023 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
10024 if (ssh->gsslibs->libraries[j].id == want_id) {
10025 s->gsslib = &ssh->gsslibs->libraries[j];
10026 goto got_gsslib; /* double break */
10031 * We always expect to have found something in
10032 * the above loop: we only came here if there
10033 * was at least one viable GSS library, and the
10034 * preference list should always mention
10035 * everything and only change the order.
10040 if (s->gsslib->gsslogmsg)
10041 logevent(s->gsslib->gsslogmsg);
10043 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
10044 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10045 ssh2_pkt_addstring(s->pktout, ssh->username);
10046 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10047 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
10048 logevent("Attempting GSSAPI authentication");
10050 /* add mechanism info */
10051 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
10053 /* number of GSSAPI mechanisms */
10054 ssh2_pkt_adduint32(s->pktout,1);
10056 /* length of OID + 2 */
10057 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
10058 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
10060 /* length of OID */
10061 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
10063 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
10064 s->gss_buf.length);
10065 ssh2_pkt_send(ssh, s->pktout);
10066 crWaitUntilV(pktin);
10067 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
10068 logevent("GSSAPI authentication request refused");
10072 /* check returned packet ... */
10074 ssh_pkt_getstring(pktin, &data, &len);
10075 s->gss_rcvtok.value = data;
10076 s->gss_rcvtok.length = len;
10077 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
10078 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
10079 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
10080 memcmp((char *)s->gss_rcvtok.value + 2,
10081 s->gss_buf.value,s->gss_buf.length) ) {
10082 logevent("GSSAPI authentication - wrong response from server");
10086 /* now start running */
10087 s->gss_stat = s->gsslib->import_name(s->gsslib,
10090 if (s->gss_stat != SSH_GSS_OK) {
10091 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
10092 logevent("GSSAPI import name failed - Bad service name");
10094 logevent("GSSAPI import name failed");
10098 /* fetch TGT into GSS engine */
10099 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
10101 if (s->gss_stat != SSH_GSS_OK) {
10102 logevent("GSSAPI authentication failed to get credentials");
10103 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
10107 /* initial tokens are empty */
10108 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
10109 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
10111 /* now enter the loop */
10113 s->gss_stat = s->gsslib->init_sec_context
10117 conf_get_int(ssh->conf, CONF_gssapifwd),
10121 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
10122 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
10123 logevent("GSSAPI authentication initialisation failed");
10125 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
10126 &s->gss_buf) == SSH_GSS_OK) {
10127 logevent(s->gss_buf.value);
10128 sfree(s->gss_buf.value);
10133 logevent("GSSAPI authentication initialised");
10135 /* Client and server now exchange tokens until GSSAPI
10136 * no longer says CONTINUE_NEEDED */
10138 if (s->gss_sndtok.length != 0) {
10139 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
10140 ssh_pkt_addstring_start(s->pktout);
10141 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
10142 ssh2_pkt_send(ssh, s->pktout);
10143 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
10146 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
10147 crWaitUntilV(pktin);
10148 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
10149 logevent("GSSAPI authentication - bad server response");
10150 s->gss_stat = SSH_GSS_FAILURE;
10153 ssh_pkt_getstring(pktin, &data, &len);
10154 s->gss_rcvtok.value = data;
10155 s->gss_rcvtok.length = len;
10157 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
10159 if (s->gss_stat != SSH_GSS_OK) {
10160 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
10161 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
10164 logevent("GSSAPI authentication loop finished OK");
10166 /* Now send the MIC */
10168 s->pktout = ssh2_pkt_init(0);
10169 micoffset = s->pktout->length;
10170 ssh_pkt_addstring_start(s->pktout);
10171 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
10172 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
10173 ssh_pkt_addstring(s->pktout, ssh->username);
10174 ssh_pkt_addstring(s->pktout, "ssh-connection");
10175 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
10177 s->gss_buf.value = (char *)s->pktout->data + micoffset;
10178 s->gss_buf.length = s->pktout->length - micoffset;
10180 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
10181 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
10182 ssh_pkt_addstring_start(s->pktout);
10183 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
10184 ssh2_pkt_send(ssh, s->pktout);
10185 s->gsslib->free_mic(s->gsslib, &mic);
10189 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
10190 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
10193 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
10196 * Keyboard-interactive authentication.
10199 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
10201 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
10203 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10204 ssh2_pkt_addstring(s->pktout, ssh->username);
10205 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10206 /* service requested */
10207 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
10209 ssh2_pkt_addstring(s->pktout, ""); /* lang */
10210 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
10211 ssh2_pkt_send(ssh, s->pktout);
10213 logevent("Attempting keyboard-interactive authentication");
10215 crWaitUntilV(pktin);
10216 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
10217 /* Server is not willing to do keyboard-interactive
10218 * at all (or, bizarrely but legally, accepts the
10219 * user without actually issuing any prompts).
10220 * Give up on it entirely. */
10222 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
10223 s->kbd_inter_refused = TRUE; /* don't try it again */
10228 * Loop while the server continues to send INFO_REQUESTs.
10230 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
10232 char *name, *inst, *lang;
10233 int name_len, inst_len, lang_len;
10237 * We've got a fresh USERAUTH_INFO_REQUEST.
10238 * Get the preamble and start building a prompt.
10240 ssh_pkt_getstring(pktin, &name, &name_len);
10241 ssh_pkt_getstring(pktin, &inst, &inst_len);
10242 ssh_pkt_getstring(pktin, &lang, &lang_len);
10243 s->cur_prompt = new_prompts(ssh->frontend);
10244 s->cur_prompt->to_server = TRUE;
10247 * Get any prompt(s) from the packet.
10249 s->num_prompts = ssh_pkt_getuint32(pktin);
10250 for (i = 0; i < s->num_prompts; i++) {
10254 static char noprompt[] =
10255 "<server failed to send prompt>: ";
10257 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
10258 echo = ssh2_pkt_getbool(pktin);
10261 prompt_len = lenof(noprompt)-1;
10263 add_prompt(s->cur_prompt,
10264 dupprintf("%.*s", prompt_len, prompt),
10269 /* FIXME: better prefix to distinguish from
10270 * local prompts? */
10271 s->cur_prompt->name =
10272 dupprintf("SSH server: %.*s", name_len, name);
10273 s->cur_prompt->name_reqd = TRUE;
10275 s->cur_prompt->name =
10276 dupstr("SSH server authentication");
10277 s->cur_prompt->name_reqd = FALSE;
10279 /* We add a prefix to try to make it clear that a prompt
10280 * has come from the server.
10281 * FIXME: ugly to print "Using..." in prompt _every_
10282 * time round. Can this be done more subtly? */
10283 /* Special case: for reasons best known to themselves,
10284 * some servers send k-i requests with no prompts and
10285 * nothing to display. Keep quiet in this case. */
10286 if (s->num_prompts || name_len || inst_len) {
10287 s->cur_prompt->instruction =
10288 dupprintf("Using keyboard-interactive authentication.%s%.*s",
10289 inst_len ? "\n" : "", inst_len, inst);
10290 s->cur_prompt->instr_reqd = TRUE;
10292 s->cur_prompt->instr_reqd = FALSE;
10296 * Display any instructions, and get the user's
10300 int ret; /* not live over crReturn */
10301 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10304 crWaitUntilV(!pktin);
10305 ret = get_userpass_input(s->cur_prompt, in, inlen);
10310 * Failed to get responses. Terminate.
10312 free_prompts(s->cur_prompt);
10313 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10314 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10321 * Send the response(s) to the server.
10323 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
10324 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
10325 for (i=0; i < s->num_prompts; i++) {
10326 ssh2_pkt_addstring(s->pktout,
10327 s->cur_prompt->prompts[i]->result);
10329 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10332 * Free the prompts structure from this iteration.
10333 * If there's another, a new one will be allocated
10334 * when we return to the top of this while loop.
10336 free_prompts(s->cur_prompt);
10339 * Get the next packet in case it's another
10342 crWaitUntilV(pktin);
10347 * We should have SUCCESS or FAILURE now.
10351 } else if (s->can_passwd) {
10354 * Plain old password authentication.
10356 int ret; /* not live over crReturn */
10357 int changereq_first_time; /* not live over crReturn */
10359 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
10361 s->cur_prompt = new_prompts(ssh->frontend);
10362 s->cur_prompt->to_server = TRUE;
10363 s->cur_prompt->name = dupstr("SSH password");
10364 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
10369 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10372 crWaitUntilV(!pktin);
10373 ret = get_userpass_input(s->cur_prompt, in, inlen);
10378 * Failed to get responses. Terminate.
10380 free_prompts(s->cur_prompt);
10381 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10382 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10387 * Squirrel away the password. (We may need it later if
10388 * asked to change it.)
10390 s->password = dupstr(s->cur_prompt->prompts[0]->result);
10391 free_prompts(s->cur_prompt);
10394 * Send the password packet.
10396 * We pad out the password packet to 256 bytes to make
10397 * it harder for an attacker to find the length of the
10400 * Anyone using a password longer than 256 bytes
10401 * probably doesn't have much to worry about from
10402 * people who find out how long their password is!
10404 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10405 ssh2_pkt_addstring(s->pktout, ssh->username);
10406 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10407 /* service requested */
10408 ssh2_pkt_addstring(s->pktout, "password");
10409 ssh2_pkt_addbool(s->pktout, FALSE);
10410 ssh2_pkt_addstring(s->pktout, s->password);
10411 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10412 logevent("Sent password");
10413 s->type = AUTH_TYPE_PASSWORD;
10416 * Wait for next packet, in case it's a password change
10419 crWaitUntilV(pktin);
10420 changereq_first_time = TRUE;
10422 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
10425 * We're being asked for a new password
10426 * (perhaps not for the first time).
10427 * Loop until the server accepts it.
10430 int got_new = FALSE; /* not live over crReturn */
10431 char *prompt; /* not live over crReturn */
10432 int prompt_len; /* not live over crReturn */
10436 if (changereq_first_time)
10437 msg = "Server requested password change";
10439 msg = "Server rejected new password";
10441 c_write_str(ssh, msg);
10442 c_write_str(ssh, "\r\n");
10445 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
10447 s->cur_prompt = new_prompts(ssh->frontend);
10448 s->cur_prompt->to_server = TRUE;
10449 s->cur_prompt->name = dupstr("New SSH password");
10450 s->cur_prompt->instruction =
10451 dupprintf("%.*s", prompt_len, NULLTOEMPTY(prompt));
10452 s->cur_prompt->instr_reqd = TRUE;
10454 * There's no explicit requirement in the protocol
10455 * for the "old" passwords in the original and
10456 * password-change messages to be the same, and
10457 * apparently some Cisco kit supports password change
10458 * by the user entering a blank password originally
10459 * and the real password subsequently, so,
10460 * reluctantly, we prompt for the old password again.
10462 * (On the other hand, some servers don't even bother
10463 * to check this field.)
10465 add_prompt(s->cur_prompt,
10466 dupstr("Current password (blank for previously entered password): "),
10468 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
10470 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
10474 * Loop until the user manages to enter the same
10479 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10482 crWaitUntilV(!pktin);
10483 ret = get_userpass_input(s->cur_prompt, in, inlen);
10488 * Failed to get responses. Terminate.
10490 /* burn the evidence */
10491 free_prompts(s->cur_prompt);
10492 smemclr(s->password, strlen(s->password));
10493 sfree(s->password);
10494 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10495 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10501 * If the user specified a new original password
10502 * (IYSWIM), overwrite any previously specified
10504 * (A side effect is that the user doesn't have to
10505 * re-enter it if they louse up the new password.)
10507 if (s->cur_prompt->prompts[0]->result[0]) {
10508 smemclr(s->password, strlen(s->password));
10509 /* burn the evidence */
10510 sfree(s->password);
10512 dupstr(s->cur_prompt->prompts[0]->result);
10516 * Check the two new passwords match.
10518 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
10519 s->cur_prompt->prompts[2]->result)
10522 /* They don't. Silly user. */
10523 c_write_str(ssh, "Passwords do not match\r\n");
10528 * Send the new password (along with the old one).
10529 * (see above for padding rationale)
10531 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10532 ssh2_pkt_addstring(s->pktout, ssh->username);
10533 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10534 /* service requested */
10535 ssh2_pkt_addstring(s->pktout, "password");
10536 ssh2_pkt_addbool(s->pktout, TRUE);
10537 ssh2_pkt_addstring(s->pktout, s->password);
10538 ssh2_pkt_addstring(s->pktout,
10539 s->cur_prompt->prompts[1]->result);
10540 free_prompts(s->cur_prompt);
10541 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10542 logevent("Sent new password");
10545 * Now see what the server has to say about it.
10546 * (If it's CHANGEREQ again, it's not happy with the
10549 crWaitUntilV(pktin);
10550 changereq_first_time = FALSE;
10555 * We need to reexamine the current pktin at the top
10556 * of the loop. Either:
10557 * - we weren't asked to change password at all, in
10558 * which case it's a SUCCESS or FAILURE with the
10560 * - we sent a new password, and the server was
10561 * either OK with it (SUCCESS or FAILURE w/partial
10562 * success) or unhappy with the _old_ password
10563 * (FAILURE w/o partial success)
10564 * In any of these cases, we go back to the top of
10565 * the loop and start again.
10570 * We don't need the old password any more, in any
10571 * case. Burn the evidence.
10573 smemclr(s->password, strlen(s->password));
10574 sfree(s->password);
10577 char *str = dupprintf("No supported authentication methods available"
10578 " (server sent: %.*s)",
10581 ssh_disconnect(ssh, str,
10582 "No supported authentication methods available",
10583 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
10593 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
10595 /* Clear up various bits and pieces from authentication. */
10596 if (s->publickey_blob) {
10597 sfree(s->publickey_algorithm);
10598 sfree(s->publickey_blob);
10599 sfree(s->publickey_comment);
10601 if (s->agent_response)
10602 sfree(s->agent_response);
10604 if (s->userauth_success && !ssh->bare_connection) {
10606 * We've just received USERAUTH_SUCCESS, and we haven't sent any
10607 * packets since. Signal the transport layer to consider enacting
10608 * delayed compression.
10610 * (Relying on we_are_in is not sufficient, as
10611 * draft-miller-secsh-compression-delayed is quite clear that it
10612 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
10613 * become set for other reasons.)
10615 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
10618 ssh->channels = newtree234(ssh_channelcmp);
10621 * Set up handlers for some connection protocol messages, so we
10622 * don't have to handle them repeatedly in this coroutine.
10624 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
10625 ssh2_msg_channel_window_adjust;
10626 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
10627 ssh2_msg_global_request;
10630 * Create the main session channel.
10632 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
10633 ssh->mainchan = NULL;
10635 ssh->mainchan = snew(struct ssh_channel);
10636 ssh->mainchan->ssh = ssh;
10637 ssh2_channel_init(ssh->mainchan);
10639 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
10641 * Just start a direct-tcpip channel and use it as the main
10644 ssh_send_port_open(ssh->mainchan,
10645 conf_get_str(ssh->conf, CONF_ssh_nc_host),
10646 conf_get_int(ssh->conf, CONF_ssh_nc_port),
10648 ssh->ncmode = TRUE;
10650 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
10651 logevent("Opening session as main channel");
10652 ssh2_pkt_send(ssh, s->pktout);
10653 ssh->ncmode = FALSE;
10655 crWaitUntilV(pktin);
10656 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
10657 bombout(("Server refused to open channel"));
10659 /* FIXME: error data comes back in FAILURE packet */
10661 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
10662 bombout(("Server's channel confirmation cited wrong channel"));
10665 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
10666 ssh->mainchan->halfopen = FALSE;
10667 ssh->mainchan->type = CHAN_MAINSESSION;
10668 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
10669 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
10670 add234(ssh->channels, ssh->mainchan);
10671 update_specials_menu(ssh->frontend);
10672 logevent("Opened main channel");
10676 * Now we have a channel, make dispatch table entries for
10677 * general channel-based messages.
10679 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
10680 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
10681 ssh2_msg_channel_data;
10682 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
10683 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
10684 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
10685 ssh2_msg_channel_open_confirmation;
10686 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
10687 ssh2_msg_channel_open_failure;
10688 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
10689 ssh2_msg_channel_request;
10690 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
10691 ssh2_msg_channel_open;
10692 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
10693 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
10696 * Now the connection protocol is properly up and running, with
10697 * all those dispatch table entries, so it's safe to let
10698 * downstreams start trying to open extra channels through us.
10700 if (ssh->connshare)
10701 share_activate(ssh->connshare, ssh->v_s);
10703 if (ssh->mainchan && ssh_is_simple(ssh)) {
10705 * This message indicates to the server that we promise
10706 * not to try to run any other channel in parallel with
10707 * this one, so it's safe for it to advertise a very large
10708 * window and leave the flow control to TCP.
10710 s->pktout = ssh2_chanreq_init(ssh->mainchan,
10711 "simple@putty.projects.tartarus.org",
10713 ssh2_pkt_send(ssh, s->pktout);
10717 * Enable port forwardings.
10719 ssh_setup_portfwd(ssh, ssh->conf);
10721 if (ssh->mainchan && !ssh->ncmode) {
10723 * Send the CHANNEL_REQUESTS for the main session channel.
10724 * Each one is handled by its own little asynchronous
10728 /* Potentially enable X11 forwarding. */
10729 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
10731 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
10733 if (!ssh->x11disp) {
10734 /* FIXME: return an error message from x11_setup_display */
10735 logevent("X11 forwarding not enabled: unable to"
10736 " initialise X display");
10738 ssh->x11auth = x11_invent_fake_auth
10739 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
10740 ssh->x11auth->disp = ssh->x11disp;
10742 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
10746 /* Potentially enable agent forwarding. */
10747 if (ssh_agent_forwarding_permitted(ssh))
10748 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
10750 /* Now allocate a pty for the session. */
10751 if (!conf_get_int(ssh->conf, CONF_nopty))
10752 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
10754 /* Send environment variables. */
10755 ssh2_setup_env(ssh->mainchan, NULL, NULL);
10758 * Start a shell or a remote command. We may have to attempt
10759 * this twice if the config data has provided a second choice
10766 if (ssh->fallback_cmd) {
10767 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
10768 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
10770 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
10771 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
10775 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
10776 ssh2_response_authconn, NULL);
10777 ssh2_pkt_addstring(s->pktout, cmd);
10779 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
10780 ssh2_response_authconn, NULL);
10781 ssh2_pkt_addstring(s->pktout, cmd);
10783 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
10784 ssh2_response_authconn, NULL);
10786 ssh2_pkt_send(ssh, s->pktout);
10788 crWaitUntilV(pktin);
10790 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
10791 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
10792 bombout(("Unexpected response to shell/command request:"
10793 " packet type %d", pktin->type));
10797 * We failed to start the command. If this is the
10798 * fallback command, we really are finished; if it's
10799 * not, and if the fallback command exists, try falling
10800 * back to it before complaining.
10802 if (!ssh->fallback_cmd &&
10803 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
10804 logevent("Primary command failed; attempting fallback");
10805 ssh->fallback_cmd = TRUE;
10808 bombout(("Server refused to start a shell/command"));
10811 logevent("Started a shell/command");
10816 ssh->editing = ssh->echoing = TRUE;
10819 ssh->state = SSH_STATE_SESSION;
10820 if (ssh->size_needed)
10821 ssh_size(ssh, ssh->term_width, ssh->term_height);
10822 if (ssh->eof_needed)
10823 ssh_special(ssh, TS_EOF);
10829 ldisc_echoedit_update(ssh->ldisc); /* cause ldisc to notice changes */
10834 s->try_send = FALSE;
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 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
10850 s->try_send = TRUE;
10854 struct ssh_channel *c;
10856 * Try to send data on all channels if we can.
10858 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
10859 if (c->type != CHAN_SHARING)
10860 ssh2_try_send_and_unthrottle(ssh, c);
10868 * Handlers for SSH-2 messages that might arrive at any moment.
10870 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
10872 /* log reason code in disconnect message */
10874 int reason, msglen;
10876 reason = ssh_pkt_getuint32(pktin);
10877 ssh_pkt_getstring(pktin, &msg, &msglen);
10879 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
10880 buf = dupprintf("Received disconnect message (%s)",
10881 ssh2_disconnect_reasons[reason]);
10883 buf = dupprintf("Received disconnect message (unknown"
10884 " type %d)", reason);
10888 buf = dupprintf("Disconnection message text: %.*s",
10889 msglen, NULLTOEMPTY(msg));
10891 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
10893 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
10894 ssh2_disconnect_reasons[reason] : "unknown",
10895 msglen, NULLTOEMPTY(msg)));
10899 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
10901 /* log the debug message */
10905 /* XXX maybe we should actually take notice of the return value */
10906 ssh2_pkt_getbool(pktin);
10907 ssh_pkt_getstring(pktin, &msg, &msglen);
10909 logeventf(ssh, "Remote debug message: %.*s", msglen, NULLTOEMPTY(msg));
10912 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
10914 do_ssh2_transport(ssh, NULL, 0, pktin);
10918 * Called if we receive a packet that isn't allowed by the protocol.
10919 * This only applies to packets whose meaning PuTTY understands.
10920 * Entirely unknown packets are handled below.
10922 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
10924 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
10925 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
10927 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
10931 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
10933 struct Packet *pktout;
10934 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
10935 ssh2_pkt_adduint32(pktout, pktin->sequence);
10937 * UNIMPLEMENTED messages MUST appear in the same order as the
10938 * messages they respond to. Hence, never queue them.
10940 ssh2_pkt_send_noqueue(ssh, pktout);
10944 * Handle the top-level SSH-2 protocol.
10946 static void ssh2_protocol_setup(Ssh ssh)
10951 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10953 for (i = 0; i < 256; i++)
10954 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10957 * Initially, we only accept transport messages (and a few generic
10958 * ones). do_ssh2_authconn will add more when it starts.
10959 * Messages that are understood but not currently acceptable go to
10960 * ssh2_msg_unexpected.
10962 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10963 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
10964 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
10965 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
10966 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
10967 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
10968 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
10969 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
10970 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
10971 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
10972 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
10973 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
10974 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
10975 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
10976 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
10977 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
10978 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
10979 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
10980 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
10981 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10982 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10983 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10984 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10985 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10986 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10987 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10988 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10989 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10990 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10991 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10992 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10993 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10994 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10997 * These messages have a special handler from the start.
10999 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
11000 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
11001 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
11004 static void ssh2_bare_connection_protocol_setup(Ssh ssh)
11009 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
11011 for (i = 0; i < 256; i++)
11012 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
11015 * Initially, we set all ssh-connection messages to 'unexpected';
11016 * do_ssh2_authconn will fill things in properly. We also handle a
11017 * couple of messages from the transport protocol which aren't
11018 * related to key exchange (UNIMPLEMENTED, IGNORE, DEBUG,
11021 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
11022 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
11023 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
11024 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
11025 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
11026 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
11027 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
11028 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
11029 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
11030 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
11031 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
11032 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
11033 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
11034 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
11036 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
11039 * These messages have a special handler from the start.
11041 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
11042 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore;
11043 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
11046 static void ssh2_timer(void *ctx, unsigned long now)
11048 Ssh ssh = (Ssh)ctx;
11050 if (ssh->state == SSH_STATE_CLOSED)
11053 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11054 conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
11055 now == ssh->next_rekey) {
11056 do_ssh2_transport(ssh, "timeout", -1, NULL);
11060 static void ssh2_protocol(Ssh ssh, const void *vin, int inlen,
11061 struct Packet *pktin)
11063 const unsigned char *in = (const unsigned char *)vin;
11064 if (ssh->state == SSH_STATE_CLOSED)
11068 ssh->incoming_data_size += pktin->encrypted_len;
11069 if (!ssh->kex_in_progress &&
11070 ssh->max_data_size != 0 &&
11071 ssh->incoming_data_size > ssh->max_data_size)
11072 do_ssh2_transport(ssh, "too much data received", -1, NULL);
11076 ssh->packet_dispatch[pktin->type](ssh, pktin);
11077 else if (!ssh->protocol_initial_phase_done)
11078 do_ssh2_transport(ssh, in, inlen, pktin);
11080 do_ssh2_authconn(ssh, in, inlen, pktin);
11083 static void ssh2_bare_connection_protocol(Ssh ssh, const void *vin, int inlen,
11084 struct Packet *pktin)
11086 const unsigned char *in = (const unsigned char *)vin;
11087 if (ssh->state == SSH_STATE_CLOSED)
11091 ssh->packet_dispatch[pktin->type](ssh, pktin);
11093 do_ssh2_authconn(ssh, in, inlen, pktin);
11096 static void ssh_cache_conf_values(Ssh ssh)
11098 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
11102 * Called to set up the connection.
11104 * Returns an error message, or NULL on success.
11106 static const char *ssh_init(void *frontend_handle, void **backend_handle,
11108 const char *host, int port, char **realhost,
11109 int nodelay, int keepalive)
11114 ssh = snew(struct ssh_tag);
11115 ssh->conf = conf_copy(conf);
11116 ssh_cache_conf_values(ssh);
11117 ssh->version = 0; /* when not ready yet */
11119 ssh->cipher = NULL;
11120 ssh->v1_cipher_ctx = NULL;
11121 ssh->crcda_ctx = NULL;
11122 ssh->cscipher = NULL;
11123 ssh->cs_cipher_ctx = NULL;
11124 ssh->sccipher = NULL;
11125 ssh->sc_cipher_ctx = NULL;
11127 ssh->cs_mac_ctx = NULL;
11129 ssh->sc_mac_ctx = NULL;
11130 ssh->cscomp = NULL;
11131 ssh->cs_comp_ctx = NULL;
11132 ssh->sccomp = NULL;
11133 ssh->sc_comp_ctx = NULL;
11135 ssh->kex_ctx = NULL;
11136 ssh->hostkey = NULL;
11137 ssh->hostkey_str = NULL;
11138 ssh->exitcode = -1;
11139 ssh->close_expected = FALSE;
11140 ssh->clean_exit = FALSE;
11141 ssh->state = SSH_STATE_PREPACKET;
11142 ssh->size_needed = FALSE;
11143 ssh->eof_needed = FALSE;
11145 ssh->logctx = NULL;
11146 ssh->deferred_send_data = NULL;
11147 ssh->deferred_len = 0;
11148 ssh->deferred_size = 0;
11149 ssh->fallback_cmd = 0;
11150 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
11151 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
11152 ssh->x11disp = NULL;
11153 ssh->x11auth = NULL;
11154 ssh->x11authtree = newtree234(x11_authcmp);
11155 ssh->v1_compressing = FALSE;
11156 ssh->v2_outgoing_sequence = 0;
11157 ssh->ssh1_rdpkt_crstate = 0;
11158 ssh->ssh2_rdpkt_crstate = 0;
11159 ssh->ssh2_bare_rdpkt_crstate = 0;
11160 ssh->ssh_gotdata_crstate = 0;
11161 ssh->do_ssh1_connection_crstate = 0;
11162 ssh->do_ssh_init_state = NULL;
11163 ssh->do_ssh_connection_init_state = NULL;
11164 ssh->do_ssh1_login_state = NULL;
11165 ssh->do_ssh2_transport_state = NULL;
11166 ssh->do_ssh2_authconn_state = NULL;
11169 ssh->mainchan = NULL;
11170 ssh->throttled_all = 0;
11171 ssh->v1_stdout_throttling = 0;
11173 ssh->queuelen = ssh->queuesize = 0;
11174 ssh->queueing = FALSE;
11175 ssh->qhead = ssh->qtail = NULL;
11176 ssh->deferred_rekey_reason = NULL;
11177 bufchain_init(&ssh->queued_incoming_data);
11178 ssh->frozen = FALSE;
11179 ssh->username = NULL;
11180 ssh->sent_console_eof = FALSE;
11181 ssh->got_pty = FALSE;
11182 ssh->bare_connection = FALSE;
11183 ssh->X11_fwd_enabled = FALSE;
11184 ssh->connshare = NULL;
11185 ssh->attempting_connshare = FALSE;
11186 ssh->session_started = FALSE;
11187 ssh->specials = NULL;
11188 ssh->n_uncert_hostkeys = 0;
11189 ssh->cross_certifying = FALSE;
11191 *backend_handle = ssh;
11194 if (crypto_startup() == 0)
11195 return "Microsoft high encryption pack not installed!";
11198 ssh->frontend = frontend_handle;
11199 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
11200 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
11202 ssh->channels = NULL;
11203 ssh->rportfwds = NULL;
11204 ssh->portfwds = NULL;
11209 ssh->conn_throttle_count = 0;
11210 ssh->overall_bufsize = 0;
11211 ssh->fallback_cmd = 0;
11213 ssh->protocol = NULL;
11215 ssh->protocol_initial_phase_done = FALSE;
11217 ssh->pinger = NULL;
11219 ssh->incoming_data_size = ssh->outgoing_data_size =
11220 ssh->deferred_data_size = 0L;
11221 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
11222 CONF_ssh_rekey_data));
11223 ssh->kex_in_progress = FALSE;
11226 ssh->gsslibs = NULL;
11229 random_ref(); /* do this now - may be needed by sharing setup code */
11231 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
11240 static void ssh_free(void *handle)
11242 Ssh ssh = (Ssh) handle;
11243 struct ssh_channel *c;
11244 struct ssh_rportfwd *pf;
11245 struct X11FakeAuth *auth;
11247 if (ssh->v1_cipher_ctx)
11248 ssh->cipher->free_context(ssh->v1_cipher_ctx);
11249 if (ssh->cs_cipher_ctx)
11250 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
11251 if (ssh->sc_cipher_ctx)
11252 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
11253 if (ssh->cs_mac_ctx)
11254 ssh->csmac->free_context(ssh->cs_mac_ctx);
11255 if (ssh->sc_mac_ctx)
11256 ssh->scmac->free_context(ssh->sc_mac_ctx);
11257 if (ssh->cs_comp_ctx) {
11259 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
11261 zlib_compress_cleanup(ssh->cs_comp_ctx);
11263 if (ssh->sc_comp_ctx) {
11265 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
11267 zlib_decompress_cleanup(ssh->sc_comp_ctx);
11270 dh_cleanup(ssh->kex_ctx);
11271 sfree(ssh->savedhost);
11273 while (ssh->queuelen-- > 0)
11274 ssh_free_packet(ssh->queue[ssh->queuelen]);
11277 while (ssh->qhead) {
11278 struct queued_handler *qh = ssh->qhead;
11279 ssh->qhead = qh->next;
11282 ssh->qhead = ssh->qtail = NULL;
11284 if (ssh->channels) {
11285 while ((c = delpos234(ssh->channels, 0)) != NULL) {
11288 if (c->u.x11.xconn != NULL)
11289 x11_close(c->u.x11.xconn);
11291 case CHAN_SOCKDATA:
11292 case CHAN_SOCKDATA_DORMANT:
11293 if (c->u.pfd.pf != NULL)
11294 pfd_close(c->u.pfd.pf);
11297 if (ssh->version == 2) {
11298 struct outstanding_channel_request *ocr, *nocr;
11299 ocr = c->v.v2.chanreq_head;
11301 ocr->handler(c, NULL, ocr->ctx);
11306 bufchain_clear(&c->v.v2.outbuffer);
11310 freetree234(ssh->channels);
11311 ssh->channels = NULL;
11314 if (ssh->connshare)
11315 sharestate_free(ssh->connshare);
11317 if (ssh->rportfwds) {
11318 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
11320 freetree234(ssh->rportfwds);
11321 ssh->rportfwds = NULL;
11323 sfree(ssh->deferred_send_data);
11325 x11_free_display(ssh->x11disp);
11326 while ((auth = delpos234(ssh->x11authtree, 0)) != NULL)
11327 x11_free_fake_auth(auth);
11328 freetree234(ssh->x11authtree);
11329 sfree(ssh->do_ssh_init_state);
11330 sfree(ssh->do_ssh1_login_state);
11331 sfree(ssh->do_ssh2_transport_state);
11332 sfree(ssh->do_ssh2_authconn_state);
11335 sfree(ssh->fullhostname);
11336 sfree(ssh->hostkey_str);
11337 sfree(ssh->specials);
11338 if (ssh->crcda_ctx) {
11339 crcda_free_context(ssh->crcda_ctx);
11340 ssh->crcda_ctx = NULL;
11343 ssh_do_close(ssh, TRUE);
11344 expire_timer_context(ssh);
11346 pinger_free(ssh->pinger);
11347 bufchain_clear(&ssh->queued_incoming_data);
11348 sfree(ssh->username);
11349 conf_free(ssh->conf);
11352 ssh_gss_cleanup(ssh->gsslibs);
11360 * Reconfigure the SSH backend.
11362 static void ssh_reconfig(void *handle, Conf *conf)
11364 Ssh ssh = (Ssh) handle;
11365 const char *rekeying = NULL;
11366 int rekey_mandatory = FALSE;
11367 unsigned long old_max_data_size;
11370 pinger_reconfig(ssh->pinger, ssh->conf, conf);
11372 ssh_setup_portfwd(ssh, conf);
11374 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
11375 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
11377 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
11378 unsigned long now = GETTICKCOUNT();
11380 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
11381 rekeying = "timeout shortened";
11383 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
11387 old_max_data_size = ssh->max_data_size;
11388 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
11389 CONF_ssh_rekey_data));
11390 if (old_max_data_size != ssh->max_data_size &&
11391 ssh->max_data_size != 0) {
11392 if (ssh->outgoing_data_size > ssh->max_data_size ||
11393 ssh->incoming_data_size > ssh->max_data_size)
11394 rekeying = "data limit lowered";
11397 if (conf_get_int(ssh->conf, CONF_compression) !=
11398 conf_get_int(conf, CONF_compression)) {
11399 rekeying = "compression setting changed";
11400 rekey_mandatory = TRUE;
11403 for (i = 0; i < CIPHER_MAX; i++)
11404 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
11405 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
11406 rekeying = "cipher settings changed";
11407 rekey_mandatory = TRUE;
11409 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
11410 conf_get_int(conf, CONF_ssh2_des_cbc)) {
11411 rekeying = "cipher settings changed";
11412 rekey_mandatory = TRUE;
11415 conf_free(ssh->conf);
11416 ssh->conf = conf_copy(conf);
11417 ssh_cache_conf_values(ssh);
11419 if (!ssh->bare_connection && rekeying) {
11420 if (!ssh->kex_in_progress) {
11421 do_ssh2_transport(ssh, rekeying, -1, NULL);
11422 } else if (rekey_mandatory) {
11423 ssh->deferred_rekey_reason = rekeying;
11429 * Called to send data down the SSH connection.
11431 static int ssh_send(void *handle, const char *buf, int len)
11433 Ssh ssh = (Ssh) handle;
11435 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
11438 ssh->protocol(ssh, (const unsigned char *)buf, len, 0);
11440 return ssh_sendbuffer(ssh);
11444 * Called to query the current amount of buffered stdin data.
11446 static int ssh_sendbuffer(void *handle)
11448 Ssh ssh = (Ssh) handle;
11449 int override_value;
11451 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
11455 * If the SSH socket itself has backed up, add the total backup
11456 * size on that to any individual buffer on the stdin channel.
11458 override_value = 0;
11459 if (ssh->throttled_all)
11460 override_value = ssh->overall_bufsize;
11462 if (ssh->version == 1) {
11463 return override_value;
11464 } else if (ssh->version == 2) {
11465 if (!ssh->mainchan)
11466 return override_value;
11468 return (override_value +
11469 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
11476 * Called to set the size of the window from SSH's POV.
11478 static void ssh_size(void *handle, int width, int height)
11480 Ssh ssh = (Ssh) handle;
11481 struct Packet *pktout;
11483 ssh->term_width = width;
11484 ssh->term_height = height;
11486 switch (ssh->state) {
11487 case SSH_STATE_BEFORE_SIZE:
11488 case SSH_STATE_PREPACKET:
11489 case SSH_STATE_CLOSED:
11490 break; /* do nothing */
11491 case SSH_STATE_INTERMED:
11492 ssh->size_needed = TRUE; /* buffer for later */
11494 case SSH_STATE_SESSION:
11495 if (!conf_get_int(ssh->conf, CONF_nopty)) {
11496 if (ssh->version == 1) {
11497 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
11498 PKT_INT, ssh->term_height,
11499 PKT_INT, ssh->term_width,
11500 PKT_INT, 0, PKT_INT, 0, PKT_END);
11501 } else if (ssh->mainchan) {
11502 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
11504 ssh2_pkt_adduint32(pktout, ssh->term_width);
11505 ssh2_pkt_adduint32(pktout, ssh->term_height);
11506 ssh2_pkt_adduint32(pktout, 0);
11507 ssh2_pkt_adduint32(pktout, 0);
11508 ssh2_pkt_send(ssh, pktout);
11516 * Return a list of the special codes that make sense in this
11519 static const struct telnet_special *ssh_get_specials(void *handle)
11521 static const struct telnet_special ssh1_ignore_special[] = {
11522 {"IGNORE message", TS_NOP}
11524 static const struct telnet_special ssh2_ignore_special[] = {
11525 {"IGNORE message", TS_NOP},
11527 static const struct telnet_special ssh2_rekey_special[] = {
11528 {"Repeat key exchange", TS_REKEY},
11530 static const struct telnet_special ssh2_session_specials[] = {
11533 /* These are the signal names defined by RFC 4254.
11534 * They include all the ISO C signals, but are a subset of the POSIX
11535 * required signals. */
11536 {"SIGINT (Interrupt)", TS_SIGINT},
11537 {"SIGTERM (Terminate)", TS_SIGTERM},
11538 {"SIGKILL (Kill)", TS_SIGKILL},
11539 {"SIGQUIT (Quit)", TS_SIGQUIT},
11540 {"SIGHUP (Hangup)", TS_SIGHUP},
11541 {"More signals", TS_SUBMENU},
11542 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
11543 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
11544 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
11545 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
11546 {NULL, TS_EXITMENU}
11548 static const struct telnet_special specials_end[] = {
11549 {NULL, TS_EXITMENU}
11552 struct telnet_special *specials = NULL;
11553 int nspecials = 0, specialsize = 0;
11555 Ssh ssh = (Ssh) handle;
11557 sfree(ssh->specials);
11559 #define ADD_SPECIALS(name) do \
11561 int len = lenof(name); \
11562 if (nspecials + len > specialsize) { \
11563 specialsize = (nspecials + len) * 5 / 4 + 32; \
11564 specials = sresize(specials, specialsize, struct telnet_special); \
11566 memcpy(specials+nspecials, name, len*sizeof(struct telnet_special)); \
11567 nspecials += len; \
11570 if (ssh->version == 1) {
11571 /* Don't bother offering IGNORE if we've decided the remote
11572 * won't cope with it, since we wouldn't bother sending it if
11574 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11575 ADD_SPECIALS(ssh1_ignore_special);
11576 } else if (ssh->version == 2) {
11577 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
11578 ADD_SPECIALS(ssh2_ignore_special);
11579 if (!(ssh->remote_bugs & BUG_SSH2_REKEY) && !ssh->bare_connection)
11580 ADD_SPECIALS(ssh2_rekey_special);
11582 ADD_SPECIALS(ssh2_session_specials);
11584 if (ssh->n_uncert_hostkeys) {
11585 static const struct telnet_special uncert_start[] = {
11587 {"Cache new host key type", TS_SUBMENU},
11589 static const struct telnet_special uncert_end[] = {
11590 {NULL, TS_EXITMENU},
11594 ADD_SPECIALS(uncert_start);
11595 for (i = 0; i < ssh->n_uncert_hostkeys; i++) {
11596 struct telnet_special uncert[1];
11597 const struct ssh_signkey *alg =
11598 hostkey_algs[ssh->uncert_hostkeys[i]].alg;
11599 uncert[0].name = alg->name;
11600 uncert[0].code = TS_LOCALSTART + ssh->uncert_hostkeys[i];
11601 ADD_SPECIALS(uncert);
11603 ADD_SPECIALS(uncert_end);
11605 } /* else we're not ready yet */
11608 ADD_SPECIALS(specials_end);
11610 ssh->specials = specials;
11617 #undef ADD_SPECIALS
11621 * Send special codes. TS_EOF is useful for `plink', so you
11622 * can send an EOF and collect resulting output (e.g. `plink
11625 static void ssh_special(void *handle, Telnet_Special code)
11627 Ssh ssh = (Ssh) handle;
11628 struct Packet *pktout;
11630 if (code == TS_EOF) {
11631 if (ssh->state != SSH_STATE_SESSION) {
11633 * Buffer the EOF in case we are pre-SESSION, so we can
11634 * send it as soon as we reach SESSION.
11636 if (code == TS_EOF)
11637 ssh->eof_needed = TRUE;
11640 if (ssh->version == 1) {
11641 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
11642 } else if (ssh->mainchan) {
11643 sshfwd_write_eof(ssh->mainchan);
11644 ssh->send_ok = 0; /* now stop trying to read from stdin */
11646 logevent("Sent EOF message");
11647 } else if (code == TS_PING || code == TS_NOP) {
11648 if (ssh->state == SSH_STATE_CLOSED
11649 || ssh->state == SSH_STATE_PREPACKET) return;
11650 if (ssh->version == 1) {
11651 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11652 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
11654 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
11655 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
11656 ssh2_pkt_addstring_start(pktout);
11657 ssh2_pkt_send_noqueue(ssh, pktout);
11660 } else if (code == TS_REKEY) {
11661 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11662 ssh->version == 2) {
11663 do_ssh2_transport(ssh, "at user request", -1, NULL);
11665 } else if (code >= TS_LOCALSTART) {
11666 ssh->hostkey = hostkey_algs[code - TS_LOCALSTART].alg;
11667 ssh->cross_certifying = TRUE;
11668 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11669 ssh->version == 2) {
11670 do_ssh2_transport(ssh, "cross-certifying new host key", -1, NULL);
11672 } else if (code == TS_BRK) {
11673 if (ssh->state == SSH_STATE_CLOSED
11674 || ssh->state == SSH_STATE_PREPACKET) return;
11675 if (ssh->version == 1) {
11676 logevent("Unable to send BREAK signal in SSH-1");
11677 } else if (ssh->mainchan) {
11678 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
11679 ssh2_pkt_adduint32(pktout, 0); /* default break length */
11680 ssh2_pkt_send(ssh, pktout);
11683 /* Is is a POSIX signal? */
11684 const char *signame = NULL;
11685 if (code == TS_SIGABRT) signame = "ABRT";
11686 if (code == TS_SIGALRM) signame = "ALRM";
11687 if (code == TS_SIGFPE) signame = "FPE";
11688 if (code == TS_SIGHUP) signame = "HUP";
11689 if (code == TS_SIGILL) signame = "ILL";
11690 if (code == TS_SIGINT) signame = "INT";
11691 if (code == TS_SIGKILL) signame = "KILL";
11692 if (code == TS_SIGPIPE) signame = "PIPE";
11693 if (code == TS_SIGQUIT) signame = "QUIT";
11694 if (code == TS_SIGSEGV) signame = "SEGV";
11695 if (code == TS_SIGTERM) signame = "TERM";
11696 if (code == TS_SIGUSR1) signame = "USR1";
11697 if (code == TS_SIGUSR2) signame = "USR2";
11698 /* The SSH-2 protocol does in principle support arbitrary named
11699 * signals, including signame@domain, but we don't support those. */
11701 /* It's a signal. */
11702 if (ssh->version == 2 && ssh->mainchan) {
11703 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
11704 ssh2_pkt_addstring(pktout, signame);
11705 ssh2_pkt_send(ssh, pktout);
11706 logeventf(ssh, "Sent signal SIG%s", signame);
11709 /* Never heard of it. Do nothing */
11714 void *new_sock_channel(void *handle, struct PortForwarding *pf)
11716 Ssh ssh = (Ssh) handle;
11717 struct ssh_channel *c;
11718 c = snew(struct ssh_channel);
11721 ssh2_channel_init(c);
11722 c->halfopen = TRUE;
11723 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
11725 add234(ssh->channels, c);
11729 unsigned ssh_alloc_sharing_channel(Ssh ssh, void *sharing_ctx)
11731 struct ssh_channel *c;
11732 c = snew(struct ssh_channel);
11735 ssh2_channel_init(c);
11736 c->type = CHAN_SHARING;
11737 c->u.sharing.ctx = sharing_ctx;
11738 add234(ssh->channels, c);
11742 void ssh_delete_sharing_channel(Ssh ssh, unsigned localid)
11744 struct ssh_channel *c;
11746 c = find234(ssh->channels, &localid, ssh_channelfind);
11748 ssh_channel_destroy(c);
11751 void ssh_send_packet_from_downstream(Ssh ssh, unsigned id, int type,
11752 const void *data, int datalen,
11753 const char *additional_log_text)
11755 struct Packet *pkt;
11757 pkt = ssh2_pkt_init(type);
11758 pkt->downstream_id = id;
11759 pkt->additional_log_text = additional_log_text;
11760 ssh2_pkt_adddata(pkt, data, datalen);
11761 ssh2_pkt_send(ssh, pkt);
11765 * This is called when stdout/stderr (the entity to which
11766 * from_backend sends data) manages to clear some backlog.
11768 static void ssh_unthrottle(void *handle, int bufsize)
11770 Ssh ssh = (Ssh) handle;
11773 if (ssh->version == 1) {
11774 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
11775 ssh->v1_stdout_throttling = 0;
11776 ssh_throttle_conn(ssh, -1);
11779 if (ssh->mainchan) {
11780 ssh2_set_window(ssh->mainchan,
11781 bufsize < ssh->mainchan->v.v2.locmaxwin ?
11782 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
11783 if (ssh_is_simple(ssh))
11786 buflimit = ssh->mainchan->v.v2.locmaxwin;
11787 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
11788 ssh->mainchan->throttling_conn = 0;
11789 ssh_throttle_conn(ssh, -1);
11795 * Now process any SSH connection data that was stashed in our
11796 * queue while we were frozen.
11798 ssh_process_queued_incoming_data(ssh);
11801 void ssh_send_port_open(void *channel, const char *hostname, int port,
11804 struct ssh_channel *c = (struct ssh_channel *)channel;
11806 struct Packet *pktout;
11808 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
11810 if (ssh->version == 1) {
11811 send_packet(ssh, SSH1_MSG_PORT_OPEN,
11812 PKT_INT, c->localid,
11815 /* PKT_STR, <org:orgport>, */
11818 pktout = ssh2_chanopen_init(c, "direct-tcpip");
11820 char *trimmed_host = host_strduptrim(hostname);
11821 ssh2_pkt_addstring(pktout, trimmed_host);
11822 sfree(trimmed_host);
11824 ssh2_pkt_adduint32(pktout, port);
11826 * We make up values for the originator data; partly it's
11827 * too much hassle to keep track, and partly I'm not
11828 * convinced the server should be told details like that
11829 * about my local network configuration.
11830 * The "originator IP address" is syntactically a numeric
11831 * IP address, and some servers (e.g., Tectia) get upset
11832 * if it doesn't match this syntax.
11834 ssh2_pkt_addstring(pktout, "0.0.0.0");
11835 ssh2_pkt_adduint32(pktout, 0);
11836 ssh2_pkt_send(ssh, pktout);
11840 static int ssh_connected(void *handle)
11842 Ssh ssh = (Ssh) handle;
11843 return ssh->s != NULL;
11846 static int ssh_sendok(void *handle)
11848 Ssh ssh = (Ssh) handle;
11849 return ssh->send_ok;
11852 static int ssh_ldisc(void *handle, int option)
11854 Ssh ssh = (Ssh) handle;
11855 if (option == LD_ECHO)
11856 return ssh->echoing;
11857 if (option == LD_EDIT)
11858 return ssh->editing;
11862 static void ssh_provide_ldisc(void *handle, void *ldisc)
11864 Ssh ssh = (Ssh) handle;
11865 ssh->ldisc = ldisc;
11868 static void ssh_provide_logctx(void *handle, void *logctx)
11870 Ssh ssh = (Ssh) handle;
11871 ssh->logctx = logctx;
11874 static int ssh_return_exitcode(void *handle)
11876 Ssh ssh = (Ssh) handle;
11877 if (ssh->s != NULL)
11880 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
11884 * cfg_info for SSH is the protocol running in this session.
11885 * (1 or 2 for the full SSH-1 or SSH-2 protocol; -1 for the bare
11886 * SSH-2 connection protocol, i.e. a downstream; 0 for not-decided-yet.)
11888 static int ssh_cfg_info(void *handle)
11890 Ssh ssh = (Ssh) handle;
11891 if (ssh->version == 0)
11892 return 0; /* don't know yet */
11893 else if (ssh->bare_connection)
11896 return ssh->version;
11900 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
11901 * that fails. This variable is the means by which scp.c can reach
11902 * into the SSH code and find out which one it got.
11904 extern int ssh_fallback_cmd(void *handle)
11906 Ssh ssh = (Ssh) handle;
11907 return ssh->fallback_cmd;
11910 Backend ssh_backend = {
11920 ssh_return_exitcode,
11924 ssh_provide_logctx,
11927 ssh_test_for_upstream,