28 * Packet type contexts, so that ssh2_pkt_type can correctly decode
29 * the ambiguous type numbers back into the correct type strings.
40 SSH2_PKTCTX_PUBLICKEY,
46 static const char *const ssh2_disconnect_reasons[] = {
48 "host not allowed to connect",
50 "key exchange failed",
51 "host authentication failed",
54 "service not available",
55 "protocol version not supported",
56 "host key not verifiable",
59 "too many connections",
60 "auth cancelled by user",
61 "no more auth methods available",
66 * Various remote-bug flags.
68 #define BUG_CHOKES_ON_SSH1_IGNORE 1
69 #define BUG_SSH2_HMAC 2
70 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
71 #define BUG_CHOKES_ON_RSA 8
72 #define BUG_SSH2_RSA_PADDING 16
73 #define BUG_SSH2_DERIVEKEY 32
74 #define BUG_SSH2_REKEY 64
75 #define BUG_SSH2_PK_SESSIONID 128
76 #define BUG_SSH2_MAXPKT 256
77 #define BUG_CHOKES_ON_SSH2_IGNORE 512
78 #define BUG_CHOKES_ON_WINADJ 1024
79 #define BUG_SENDS_LATE_REQUEST_REPLY 2048
80 #define BUG_SSH2_OLDGEX 4096
82 #define DH_MIN_SIZE 1024
83 #define DH_MAX_SIZE 8192
86 * Codes for terminal modes.
87 * Most of these are the same in SSH-1 and SSH-2.
88 * This list is derived from RFC 4254 and
92 const char* const mode;
94 enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
96 /* "V" prefix discarded for special characters relative to SSH specs */
97 { "INTR", 1, TTY_OP_CHAR },
98 { "QUIT", 2, TTY_OP_CHAR },
99 { "ERASE", 3, TTY_OP_CHAR },
100 { "KILL", 4, TTY_OP_CHAR },
101 { "EOF", 5, TTY_OP_CHAR },
102 { "EOL", 6, TTY_OP_CHAR },
103 { "EOL2", 7, TTY_OP_CHAR },
104 { "START", 8, TTY_OP_CHAR },
105 { "STOP", 9, TTY_OP_CHAR },
106 { "SUSP", 10, TTY_OP_CHAR },
107 { "DSUSP", 11, TTY_OP_CHAR },
108 { "REPRINT", 12, TTY_OP_CHAR },
109 { "WERASE", 13, TTY_OP_CHAR },
110 { "LNEXT", 14, TTY_OP_CHAR },
111 { "FLUSH", 15, TTY_OP_CHAR },
112 { "SWTCH", 16, TTY_OP_CHAR },
113 { "STATUS", 17, TTY_OP_CHAR },
114 { "DISCARD", 18, TTY_OP_CHAR },
115 { "IGNPAR", 30, TTY_OP_BOOL },
116 { "PARMRK", 31, TTY_OP_BOOL },
117 { "INPCK", 32, TTY_OP_BOOL },
118 { "ISTRIP", 33, TTY_OP_BOOL },
119 { "INLCR", 34, TTY_OP_BOOL },
120 { "IGNCR", 35, TTY_OP_BOOL },
121 { "ICRNL", 36, TTY_OP_BOOL },
122 { "IUCLC", 37, TTY_OP_BOOL },
123 { "IXON", 38, TTY_OP_BOOL },
124 { "IXANY", 39, TTY_OP_BOOL },
125 { "IXOFF", 40, TTY_OP_BOOL },
126 { "IMAXBEL", 41, TTY_OP_BOOL },
127 { "ISIG", 50, TTY_OP_BOOL },
128 { "ICANON", 51, TTY_OP_BOOL },
129 { "XCASE", 52, TTY_OP_BOOL },
130 { "ECHO", 53, TTY_OP_BOOL },
131 { "ECHOE", 54, TTY_OP_BOOL },
132 { "ECHOK", 55, TTY_OP_BOOL },
133 { "ECHONL", 56, TTY_OP_BOOL },
134 { "NOFLSH", 57, TTY_OP_BOOL },
135 { "TOSTOP", 58, TTY_OP_BOOL },
136 { "IEXTEN", 59, TTY_OP_BOOL },
137 { "ECHOCTL", 60, TTY_OP_BOOL },
138 { "ECHOKE", 61, TTY_OP_BOOL },
139 { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */
140 { "OPOST", 70, TTY_OP_BOOL },
141 { "OLCUC", 71, TTY_OP_BOOL },
142 { "ONLCR", 72, TTY_OP_BOOL },
143 { "OCRNL", 73, TTY_OP_BOOL },
144 { "ONOCR", 74, TTY_OP_BOOL },
145 { "ONLRET", 75, TTY_OP_BOOL },
146 { "CS7", 90, TTY_OP_BOOL },
147 { "CS8", 91, TTY_OP_BOOL },
148 { "PARENB", 92, TTY_OP_BOOL },
149 { "PARODD", 93, TTY_OP_BOOL }
152 /* Miscellaneous other tty-related constants. */
153 #define SSH_TTY_OP_END 0
154 /* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */
155 #define SSH1_TTY_OP_ISPEED 192
156 #define SSH1_TTY_OP_OSPEED 193
157 #define SSH2_TTY_OP_ISPEED 128
158 #define SSH2_TTY_OP_OSPEED 129
160 /* Helper functions for parsing tty-related config. */
161 static unsigned int ssh_tty_parse_specchar(char *s)
166 ret = ctrlparse(s, &next);
167 if (!next) ret = s[0];
169 ret = 255; /* special value meaning "don't set" */
173 static unsigned int ssh_tty_parse_boolean(char *s)
175 if (stricmp(s, "yes") == 0 ||
176 stricmp(s, "on") == 0 ||
177 stricmp(s, "true") == 0 ||
178 stricmp(s, "+") == 0)
180 else if (stricmp(s, "no") == 0 ||
181 stricmp(s, "off") == 0 ||
182 stricmp(s, "false") == 0 ||
183 stricmp(s, "-") == 0)
184 return 0; /* false */
186 return (atoi(s) != 0);
189 #define translate(x) if (type == x) return #x
190 #define translatek(x,ctx) if (type == x && (pkt_kctx == ctx)) return #x
191 #define translatea(x,ctx) if (type == x && (pkt_actx == ctx)) return #x
192 static const char *ssh1_pkt_type(int type)
194 translate(SSH1_MSG_DISCONNECT);
195 translate(SSH1_SMSG_PUBLIC_KEY);
196 translate(SSH1_CMSG_SESSION_KEY);
197 translate(SSH1_CMSG_USER);
198 translate(SSH1_CMSG_AUTH_RSA);
199 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
200 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
201 translate(SSH1_CMSG_AUTH_PASSWORD);
202 translate(SSH1_CMSG_REQUEST_PTY);
203 translate(SSH1_CMSG_WINDOW_SIZE);
204 translate(SSH1_CMSG_EXEC_SHELL);
205 translate(SSH1_CMSG_EXEC_CMD);
206 translate(SSH1_SMSG_SUCCESS);
207 translate(SSH1_SMSG_FAILURE);
208 translate(SSH1_CMSG_STDIN_DATA);
209 translate(SSH1_SMSG_STDOUT_DATA);
210 translate(SSH1_SMSG_STDERR_DATA);
211 translate(SSH1_CMSG_EOF);
212 translate(SSH1_SMSG_EXIT_STATUS);
213 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
214 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
215 translate(SSH1_MSG_CHANNEL_DATA);
216 translate(SSH1_MSG_CHANNEL_CLOSE);
217 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
218 translate(SSH1_SMSG_X11_OPEN);
219 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
220 translate(SSH1_MSG_PORT_OPEN);
221 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
222 translate(SSH1_SMSG_AGENT_OPEN);
223 translate(SSH1_MSG_IGNORE);
224 translate(SSH1_CMSG_EXIT_CONFIRMATION);
225 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
226 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
227 translate(SSH1_MSG_DEBUG);
228 translate(SSH1_CMSG_REQUEST_COMPRESSION);
229 translate(SSH1_CMSG_AUTH_TIS);
230 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
231 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
232 translate(SSH1_CMSG_AUTH_CCARD);
233 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
234 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
237 static const char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx,
240 translatea(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,SSH2_PKTCTX_GSSAPI);
241 translatea(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,SSH2_PKTCTX_GSSAPI);
242 translatea(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,SSH2_PKTCTX_GSSAPI);
243 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERROR,SSH2_PKTCTX_GSSAPI);
244 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK,SSH2_PKTCTX_GSSAPI);
245 translatea(SSH2_MSG_USERAUTH_GSSAPI_MIC, SSH2_PKTCTX_GSSAPI);
246 translate(SSH2_MSG_DISCONNECT);
247 translate(SSH2_MSG_IGNORE);
248 translate(SSH2_MSG_UNIMPLEMENTED);
249 translate(SSH2_MSG_DEBUG);
250 translate(SSH2_MSG_SERVICE_REQUEST);
251 translate(SSH2_MSG_SERVICE_ACCEPT);
252 translate(SSH2_MSG_KEXINIT);
253 translate(SSH2_MSG_NEWKEYS);
254 translatek(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
255 translatek(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
256 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST_OLD, SSH2_PKTCTX_DHGEX);
257 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
258 translatek(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
259 translatek(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
260 translatek(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
261 translatek(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX);
262 translatek(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX);
263 translatek(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX);
264 translatek(SSH2_MSG_KEX_ECDH_INIT, SSH2_PKTCTX_ECDHKEX);
265 translatek(SSH2_MSG_KEX_ECDH_REPLY, SSH2_PKTCTX_ECDHKEX);
266 translate(SSH2_MSG_USERAUTH_REQUEST);
267 translate(SSH2_MSG_USERAUTH_FAILURE);
268 translate(SSH2_MSG_USERAUTH_SUCCESS);
269 translate(SSH2_MSG_USERAUTH_BANNER);
270 translatea(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
271 translatea(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
272 translatea(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
273 translatea(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
274 translate(SSH2_MSG_GLOBAL_REQUEST);
275 translate(SSH2_MSG_REQUEST_SUCCESS);
276 translate(SSH2_MSG_REQUEST_FAILURE);
277 translate(SSH2_MSG_CHANNEL_OPEN);
278 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
279 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
280 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
281 translate(SSH2_MSG_CHANNEL_DATA);
282 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
283 translate(SSH2_MSG_CHANNEL_EOF);
284 translate(SSH2_MSG_CHANNEL_CLOSE);
285 translate(SSH2_MSG_CHANNEL_REQUEST);
286 translate(SSH2_MSG_CHANNEL_SUCCESS);
287 translate(SSH2_MSG_CHANNEL_FAILURE);
293 /* Enumeration values for fields in SSH-1 packets */
295 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
299 * Coroutine mechanics for the sillier bits of the code. If these
300 * macros look impenetrable to you, you might find it helpful to
303 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
305 * which explains the theory behind these macros.
307 * In particular, if you are getting `case expression not constant'
308 * errors when building with MS Visual Studio, this is because MS's
309 * Edit and Continue debugging feature causes their compiler to
310 * violate ANSI C. To disable Edit and Continue debugging:
312 * - right-click ssh.c in the FileView
314 * - select the C/C++ tab and the General category
315 * - under `Debug info:', select anything _other_ than `Program
316 * Database for Edit and Continue'.
318 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
319 #define crBeginState crBegin(s->crLine)
320 #define crStateP(t, v) \
322 if (!(v)) { s = (v) = snew(struct t); s->crLine = 0; } \
324 #define crState(t) crStateP(t, ssh->t)
325 #define crFinish(z) } *crLine = 0; return (z); }
326 #define crFinishV } *crLine = 0; return; }
327 #define crFinishFree(z) } sfree(s); return (z); }
328 #define crFinishFreeV } sfree(s); return; }
329 #define crReturn(z) \
331 *crLine =__LINE__; return (z); case __LINE__:;\
335 *crLine=__LINE__; return; case __LINE__:;\
337 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
338 #define crStopV do{ *crLine = 0; return; }while(0)
339 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
340 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
344 static struct Packet *ssh1_pkt_init(int pkt_type);
345 static struct Packet *ssh2_pkt_init(int pkt_type);
346 static void ssh_pkt_ensure(struct Packet *, int length);
347 static void ssh_pkt_adddata(struct Packet *, const void *data, int len);
348 static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
349 static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
350 static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
351 static void ssh_pkt_addstring_start(struct Packet *);
352 static void ssh_pkt_addstring_str(struct Packet *, const char *data);
353 static void ssh_pkt_addstring_data(struct Packet *, const char *data, int len);
354 static void ssh_pkt_addstring(struct Packet *, const char *data);
355 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
356 static void ssh1_pkt_addmp(struct Packet *, Bignum b);
357 static void ssh2_pkt_addmp(struct Packet *, Bignum b);
358 static int ssh2_pkt_construct(Ssh, struct Packet *);
359 static void ssh2_pkt_send(Ssh, struct Packet *);
360 static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
361 static int do_ssh1_login(Ssh ssh, const unsigned char *in, int inlen,
362 struct Packet *pktin);
363 static void do_ssh2_authconn(Ssh ssh, const unsigned char *in, int inlen,
364 struct Packet *pktin);
365 static void ssh2_channel_check_close(struct ssh_channel *c);
366 static void ssh_channel_destroy(struct ssh_channel *c);
369 * Buffer management constants. There are several of these for
370 * various different purposes:
372 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
373 * on a local data stream before we throttle the whole SSH
374 * connection (in SSH-1 only). Throttling the whole connection is
375 * pretty drastic so we set this high in the hope it won't
378 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
379 * on the SSH connection itself before we defensively throttle
380 * _all_ local data streams. This is pretty drastic too (though
381 * thankfully unlikely in SSH-2 since the window mechanism should
382 * ensure that the server never has any need to throttle its end
383 * of the connection), so we set this high as well.
385 * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
388 * - OUR_V2_BIGWIN is the window size we advertise for the only
389 * channel in a simple connection. It must be <= INT_MAX.
391 * - OUR_V2_MAXPKT is the official "maximum packet size" we send
392 * to the remote side. This actually has nothing to do with the
393 * size of the _packet_, but is instead a limit on the amount
394 * of data we're willing to receive in a single SSH2 channel
397 * - OUR_V2_PACKETLIMIT is actually the maximum size of SSH
398 * _packet_ we're prepared to cope with. It must be a multiple
399 * of the cipher block size, and must be at least 35000.
402 #define SSH1_BUFFER_LIMIT 32768
403 #define SSH_MAX_BACKLOG 32768
404 #define OUR_V2_WINSIZE 16384
405 #define OUR_V2_BIGWIN 0x7fffffff
406 #define OUR_V2_MAXPKT 0x4000UL
407 #define OUR_V2_PACKETLIMIT 0x9000UL
409 const static struct ssh_signkey *hostkey_algs[] = {
411 &ssh_ecdsa_nistp256, &ssh_ecdsa_nistp384, &ssh_ecdsa_nistp521,
415 const static struct ssh_mac *macs[] = {
416 &ssh_hmac_sha256, &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
418 const static struct ssh_mac *buggymacs[] = {
419 &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
422 static void *ssh_comp_none_init(void)
426 static void ssh_comp_none_cleanup(void *handle)
429 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
430 unsigned char **outblock, int *outlen)
434 static int ssh_comp_none_disable(void *handle)
438 const static struct ssh_compress ssh_comp_none = {
440 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
441 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
442 ssh_comp_none_disable, NULL
444 extern const struct ssh_compress ssh_zlib;
445 const static struct ssh_compress *compressions[] = {
446 &ssh_zlib, &ssh_comp_none
449 enum { /* channel types */
454 CHAN_SOCKDATA_DORMANT, /* one the remote hasn't confirmed */
456 * CHAN_SHARING indicates a channel which is tracked here on
457 * behalf of a connection-sharing downstream. We do almost nothing
458 * with these channels ourselves: all messages relating to them
459 * get thrown straight to sshshare.c and passed on almost
460 * unmodified to downstream.
464 * CHAN_ZOMBIE is used to indicate a channel for which we've
465 * already destroyed the local data source: for instance, if a
466 * forwarded port experiences a socket error on the local side, we
467 * immediately destroy its local socket and turn the SSH channel
473 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
474 typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
475 typedef void (*cchandler_fn_t)(struct ssh_channel *, struct Packet *, void *);
478 * Each channel has a queue of outstanding CHANNEL_REQUESTS and their
481 struct outstanding_channel_request {
482 cchandler_fn_t handler;
484 struct outstanding_channel_request *next;
488 * 2-3-4 tree storing channels.
491 Ssh ssh; /* pointer back to main context */
492 unsigned remoteid, localid;
494 /* True if we opened this channel but server hasn't confirmed. */
497 * In SSH-1, this value contains four bits:
499 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
500 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
501 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
502 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
504 * A channel is completely finished with when all four bits are set.
506 * In SSH-2, the four bits mean:
508 * 1 We have sent SSH2_MSG_CHANNEL_EOF.
509 * 2 We have sent SSH2_MSG_CHANNEL_CLOSE.
510 * 4 We have received SSH2_MSG_CHANNEL_EOF.
511 * 8 We have received SSH2_MSG_CHANNEL_CLOSE.
513 * A channel is completely finished with when we have both sent
514 * and received CLOSE.
516 * The symbolic constants below use the SSH-2 terminology, which
517 * is a bit confusing in SSH-1, but we have to use _something_.
519 #define CLOSES_SENT_EOF 1
520 #define CLOSES_SENT_CLOSE 2
521 #define CLOSES_RCVD_EOF 4
522 #define CLOSES_RCVD_CLOSE 8
526 * This flag indicates that an EOF is pending on the outgoing side
527 * of the channel: that is, wherever we're getting the data for
528 * this channel has sent us some data followed by EOF. We can't
529 * actually send the EOF until we've finished sending the data, so
530 * we set this flag instead to remind us to do so once our buffer
536 * True if this channel is causing the underlying connection to be
541 struct ssh2_data_channel {
543 unsigned remwindow, remmaxpkt;
544 /* locwindow is signed so we can cope with excess data. */
545 int locwindow, locmaxwin;
547 * remlocwin is the amount of local window that we think
548 * the remote end had available to it after it sent the
549 * last data packet or window adjust ack.
553 * These store the list of channel requests that haven't
556 struct outstanding_channel_request *chanreq_head, *chanreq_tail;
557 enum { THROTTLED, UNTHROTTLING, UNTHROTTLED } throttle_state;
561 struct ssh_agent_channel {
562 unsigned char *message;
563 unsigned char msglen[4];
564 unsigned lensofar, totallen;
565 int outstanding_requests;
567 struct ssh_x11_channel {
568 struct X11Connection *xconn;
571 struct ssh_pfd_channel {
572 struct PortForwarding *pf;
574 struct ssh_sharing_channel {
581 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
582 * use this structure in different ways, reflecting SSH-2's
583 * altogether saner approach to port forwarding.
585 * In SSH-1, you arrange a remote forwarding by sending the server
586 * the remote port number, and the local destination host:port.
587 * When a connection comes in, the server sends you back that
588 * host:port pair, and you connect to it. This is a ready-made
589 * security hole if you're not on the ball: a malicious server
590 * could send you back _any_ host:port pair, so if you trustingly
591 * connect to the address it gives you then you've just opened the
592 * entire inside of your corporate network just by connecting
593 * through it to a dodgy SSH server. Hence, we must store a list of
594 * host:port pairs we _are_ trying to forward to, and reject a
595 * connection request from the server if it's not in the list.
597 * In SSH-2, each side of the connection minds its own business and
598 * doesn't send unnecessary information to the other. You arrange a
599 * remote forwarding by sending the server just the remote port
600 * number. When a connection comes in, the server tells you which
601 * of its ports was connected to; and _you_ have to remember what
602 * local host:port pair went with that port number.
604 * Hence, in SSH-1 this structure is indexed by destination
605 * host:port pair, whereas in SSH-2 it is indexed by source port.
607 struct ssh_portfwd; /* forward declaration */
609 struct ssh_rportfwd {
610 unsigned sport, dport;
614 struct ssh_portfwd *pfrec;
617 static void free_rportfwd(struct ssh_rportfwd *pf)
620 sfree(pf->sportdesc);
628 * Separately to the rportfwd tree (which is for looking up port
629 * open requests from the server), a tree of _these_ structures is
630 * used to keep track of all the currently open port forwardings,
631 * so that we can reconfigure in mid-session if the user requests
635 enum { DESTROY, KEEP, CREATE } status;
637 unsigned sport, dport;
640 struct ssh_rportfwd *remote;
642 struct PortListener *local;
644 #define free_portfwd(pf) ( \
645 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
646 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
649 long length; /* length of packet: see below */
650 long forcepad; /* SSH-2: force padding to at least this length */
651 int type; /* only used for incoming packets */
652 unsigned long sequence; /* SSH-2 incoming sequence number */
653 unsigned char *data; /* allocated storage */
654 unsigned char *body; /* offset of payload within `data' */
655 long savedpos; /* dual-purpose saved packet position: see below */
656 long maxlen; /* amount of storage allocated for `data' */
657 long encrypted_len; /* for SSH-2 total-size counting */
660 * A note on the 'length' and 'savedpos' fields above.
662 * Incoming packets are set up so that pkt->length is measured
663 * relative to pkt->body, which itself points to a few bytes after
664 * pkt->data (skipping some uninteresting header fields including
665 * the packet type code). The ssh_pkt_get* functions all expect
666 * this setup, and they also use pkt->savedpos to indicate how far
667 * through the packet being decoded they've got - and that, too,
668 * is an offset from pkt->body rather than pkt->data.
670 * During construction of an outgoing packet, however, pkt->length
671 * is measured relative to the base pointer pkt->data, and
672 * pkt->body is not really used for anything until the packet is
673 * ready for sending. In this mode, pkt->savedpos is reused as a
674 * temporary variable by the addstring functions, which write out
675 * a string length field and then keep going back and updating it
676 * as more data is appended to the subsequent string data field;
677 * pkt->savedpos stores the offset (again relative to pkt->data)
678 * of the start of the string data field.
681 /* Extra metadata used in SSH packet logging mode, allowing us to
682 * log in the packet header line that the packet came from a
683 * connection-sharing downstream and what if anything unusual was
684 * done to it. The additional_log_text field is expected to be a
685 * static string - it will not be freed. */
686 unsigned downstream_id;
687 const char *additional_log_text;
690 static void ssh1_protocol(Ssh ssh, const void *vin, int inlen,
691 struct Packet *pktin);
692 static void ssh2_protocol(Ssh ssh, const void *vin, int inlen,
693 struct Packet *pktin);
694 static void ssh2_bare_connection_protocol(Ssh ssh, const void *vin, int inlen,
695 struct Packet *pktin);
696 static void ssh1_protocol_setup(Ssh ssh);
697 static void ssh2_protocol_setup(Ssh ssh);
698 static void ssh2_bare_connection_protocol_setup(Ssh ssh);
699 static void ssh_size(void *handle, int width, int height);
700 static void ssh_special(void *handle, Telnet_Special);
701 static int ssh2_try_send(struct ssh_channel *c);
702 static void ssh2_add_channel_data(struct ssh_channel *c,
703 const char *buf, int len);
704 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
705 static void ssh2_set_window(struct ssh_channel *c, int newwin);
706 static int ssh_sendbuffer(void *handle);
707 static int ssh_do_close(Ssh ssh, int notify_exit);
708 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
709 static int ssh2_pkt_getbool(struct Packet *pkt);
710 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
711 static void ssh2_timer(void *ctx, unsigned long now);
712 static void do_ssh2_transport(Ssh ssh, const void *vin, int inlen,
713 struct Packet *pktin);
714 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin);
716 struct rdpkt1_state_tag {
717 long len, pad, biglen, to_read;
718 unsigned long realcrc, gotcrc;
722 struct Packet *pktin;
725 struct rdpkt2_state_tag {
726 long len, pad, payload, packetlen, maclen;
729 unsigned long incoming_sequence;
730 struct Packet *pktin;
733 struct rdpkt2_bare_state_tag {
737 unsigned long incoming_sequence;
738 struct Packet *pktin;
741 struct queued_handler;
742 struct queued_handler {
744 chandler_fn_t handler;
746 struct queued_handler *next;
750 const struct plug_function_table *fn;
751 /* the above field _must_ be first in the structure */
761 unsigned char session_key[32];
763 int v1_remote_protoflags;
764 int v1_local_protoflags;
765 int agentfwd_enabled;
768 const struct ssh_cipher *cipher;
771 const struct ssh2_cipher *cscipher, *sccipher;
772 void *cs_cipher_ctx, *sc_cipher_ctx;
773 const struct ssh_mac *csmac, *scmac;
774 int csmac_etm, scmac_etm;
775 void *cs_mac_ctx, *sc_mac_ctx;
776 const struct ssh_compress *cscomp, *sccomp;
777 void *cs_comp_ctx, *sc_comp_ctx;
778 const struct ssh_kex *kex;
779 const struct ssh_signkey *hostkey;
780 char *hostkey_str; /* string representation, for easy checking in rekeys */
781 unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN];
782 int v2_session_id_len;
786 int attempting_connshare;
792 int echoing, editing;
796 int ospeed, ispeed; /* temporaries */
797 int term_width, term_height;
799 tree234 *channels; /* indexed by local id */
800 struct ssh_channel *mainchan; /* primary session channel */
801 int ncmode; /* is primary channel direct-tcpip? */
806 tree234 *rportfwds, *portfwds;
810 SSH_STATE_BEFORE_SIZE,
816 int size_needed, eof_needed;
817 int sent_console_eof;
818 int got_pty; /* affects EOF behaviour on main channel */
820 struct Packet **queue;
821 int queuelen, queuesize;
823 unsigned char *deferred_send_data;
824 int deferred_len, deferred_size;
827 * Gross hack: pscp will try to start SFTP but fall back to
828 * scp1 if that fails. This variable is the means by which
829 * scp.c can reach into the SSH code and find out which one it
834 bufchain banner; /* accumulates banners during do_ssh2_authconn */
839 struct X11Display *x11disp;
840 struct X11FakeAuth *x11auth;
841 tree234 *x11authtree;
844 int conn_throttle_count;
847 int v1_stdout_throttling;
848 unsigned long v2_outgoing_sequence;
850 int ssh1_rdpkt_crstate;
851 int ssh2_rdpkt_crstate;
852 int ssh2_bare_rdpkt_crstate;
853 int ssh_gotdata_crstate;
854 int do_ssh1_connection_crstate;
856 void *do_ssh_init_state;
857 void *do_ssh1_login_state;
858 void *do_ssh2_transport_state;
859 void *do_ssh2_authconn_state;
860 void *do_ssh_connection_init_state;
862 struct rdpkt1_state_tag rdpkt1_state;
863 struct rdpkt2_state_tag rdpkt2_state;
864 struct rdpkt2_bare_state_tag rdpkt2_bare_state;
866 /* SSH-1 and SSH-2 use this for different things, but both use it */
867 int protocol_initial_phase_done;
869 void (*protocol) (Ssh ssh, const void *vin, int inlen,
871 struct Packet *(*s_rdpkt) (Ssh ssh, const unsigned char **data,
873 int (*do_ssh_init)(Ssh ssh, unsigned char c);
876 * We maintain our own copy of a Conf structure here. That way,
877 * when we're passed a new one for reconfiguration, we can check
878 * the differences and potentially reconfigure port forwardings
879 * etc in mid-session.
884 * Values cached out of conf so as to avoid the tree234 lookup
885 * cost every time they're used.
890 * Dynamically allocated username string created during SSH
891 * login. Stored in here rather than in the coroutine state so
892 * that it'll be reliably freed if we shut down the SSH session
893 * at some unexpected moment.
898 * Used to transfer data back from async callbacks.
900 void *agent_response;
901 int agent_response_len;
905 * The SSH connection can be set as `frozen', meaning we are
906 * not currently accepting incoming data from the network. This
907 * is slightly more serious than setting the _socket_ as
908 * frozen, because we may already have had data passed to us
909 * from the network which we need to delay processing until
910 * after the freeze is lifted, so we also need a bufchain to
914 bufchain queued_incoming_data;
917 * Dispatch table for packet types that we may have to deal
920 handler_fn_t packet_dispatch[256];
923 * Queues of one-off handler functions for success/failure
924 * indications from a request.
926 struct queued_handler *qhead, *qtail;
927 handler_fn_t q_saved_handler1, q_saved_handler2;
930 * This module deals with sending keepalives.
935 * Track incoming and outgoing data sizes and time, for
938 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
939 unsigned long max_data_size;
941 unsigned long next_rekey, last_rekey;
942 const char *deferred_rekey_reason;
945 * Fully qualified host name, which we need if doing GSSAPI.
951 * GSSAPI libraries for this session.
953 struct ssh_gss_liblist *gsslibs;
957 #define logevent(s) logevent(ssh->frontend, s)
959 /* logevent, only printf-formatted. */
960 static void logeventf(Ssh ssh, const char *fmt, ...)
966 buf = dupvprintf(fmt, ap);
972 static void bomb_out(Ssh ssh, char *text)
974 ssh_do_close(ssh, FALSE);
976 connection_fatal(ssh->frontend, "%s", text);
980 #define bombout(msg) bomb_out(ssh, dupprintf msg)
982 /* Helper function for common bits of parsing ttymodes. */
983 static void parse_ttymodes(Ssh ssh,
984 void (*do_mode)(void *data, char *mode, char *val),
989 for (val = conf_get_str_strs(ssh->conf, CONF_ttymodes, NULL, &key);
991 val = conf_get_str_strs(ssh->conf, CONF_ttymodes, key, &key)) {
993 * val[0] is either 'V', indicating that an explicit value
994 * follows it, or 'A' indicating that we should pass the
995 * value through from the local environment via get_ttymode.
998 val = get_ttymode(ssh->frontend, key);
1000 do_mode(data, key, val);
1004 do_mode(data, key, val + 1); /* skip the 'V' */
1008 static int ssh_channelcmp(void *av, void *bv)
1010 struct ssh_channel *a = (struct ssh_channel *) av;
1011 struct ssh_channel *b = (struct ssh_channel *) bv;
1012 if (a->localid < b->localid)
1014 if (a->localid > b->localid)
1018 static int ssh_channelfind(void *av, void *bv)
1020 unsigned *a = (unsigned *) av;
1021 struct ssh_channel *b = (struct ssh_channel *) bv;
1022 if (*a < b->localid)
1024 if (*a > b->localid)
1029 static int ssh_rportcmp_ssh1(void *av, void *bv)
1031 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1032 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1034 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
1035 return i < 0 ? -1 : +1;
1036 if (a->dport > b->dport)
1038 if (a->dport < b->dport)
1043 static int ssh_rportcmp_ssh2(void *av, void *bv)
1045 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1046 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1048 if ( (i = strcmp(a->shost, b->shost)) != 0)
1049 return i < 0 ? -1 : +1;
1050 if (a->sport > b->sport)
1052 if (a->sport < b->sport)
1058 * Special form of strcmp which can cope with NULL inputs. NULL is
1059 * defined to sort before even the empty string.
1061 static int nullstrcmp(const char *a, const char *b)
1063 if (a == NULL && b == NULL)
1069 return strcmp(a, b);
1072 static int ssh_portcmp(void *av, void *bv)
1074 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
1075 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
1077 if (a->type > b->type)
1079 if (a->type < b->type)
1081 if (a->addressfamily > b->addressfamily)
1083 if (a->addressfamily < b->addressfamily)
1085 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
1086 return i < 0 ? -1 : +1;
1087 if (a->sport > b->sport)
1089 if (a->sport < b->sport)
1091 if (a->type != 'D') {
1092 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
1093 return i < 0 ? -1 : +1;
1094 if (a->dport > b->dport)
1096 if (a->dport < b->dport)
1102 static int alloc_channel_id(Ssh ssh)
1104 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1105 unsigned low, high, mid;
1107 struct ssh_channel *c;
1110 * First-fit allocation of channel numbers: always pick the
1111 * lowest unused one. To do this, binary-search using the
1112 * counted B-tree to find the largest channel ID which is in a
1113 * contiguous sequence from the beginning. (Precisely
1114 * everything in that sequence must have ID equal to its tree
1115 * index plus CHANNEL_NUMBER_OFFSET.)
1117 tsize = count234(ssh->channels);
1121 while (high - low > 1) {
1122 mid = (high + low) / 2;
1123 c = index234(ssh->channels, mid);
1124 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1125 low = mid; /* this one is fine */
1127 high = mid; /* this one is past it */
1130 * Now low points to either -1, or the tree index of the
1131 * largest ID in the initial sequence.
1134 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
1135 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
1137 return low + 1 + CHANNEL_NUMBER_OFFSET;
1140 static void c_write_stderr(int trusted, const char *buf, int len)
1143 for (i = 0; i < len; i++)
1144 if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60)))
1145 fputc(buf[i], stderr);
1148 static void c_write(Ssh ssh, const char *buf, int len)
1150 if (flags & FLAG_STDERR)
1151 c_write_stderr(1, buf, len);
1153 from_backend(ssh->frontend, 1, buf, len);
1156 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
1158 if (flags & FLAG_STDERR)
1159 c_write_stderr(0, buf, len);
1161 from_backend_untrusted(ssh->frontend, buf, len);
1164 static void c_write_str(Ssh ssh, const char *buf)
1166 c_write(ssh, buf, strlen(buf));
1169 static void ssh_free_packet(struct Packet *pkt)
1174 static struct Packet *ssh_new_packet(void)
1176 struct Packet *pkt = snew(struct Packet);
1178 pkt->body = pkt->data = NULL;
1184 static void ssh1_log_incoming_packet(Ssh ssh, struct Packet *pkt)
1187 struct logblank_t blanks[4];
1193 if (ssh->logomitdata &&
1194 (pkt->type == SSH1_SMSG_STDOUT_DATA ||
1195 pkt->type == SSH1_SMSG_STDERR_DATA ||
1196 pkt->type == SSH1_MSG_CHANNEL_DATA)) {
1197 /* "Session data" packets - omit the data string. */
1198 if (pkt->type == SSH1_MSG_CHANNEL_DATA)
1199 ssh_pkt_getuint32(pkt); /* skip channel id */
1200 blanks[nblanks].offset = pkt->savedpos + 4;
1201 blanks[nblanks].type = PKTLOG_OMIT;
1202 ssh_pkt_getstring(pkt, &str, &slen);
1204 blanks[nblanks].len = slen;
1208 log_packet(ssh->logctx, PKT_INCOMING, pkt->type,
1209 ssh1_pkt_type(pkt->type),
1210 pkt->body, pkt->length, nblanks, blanks, NULL,
1214 static void ssh1_log_outgoing_packet(Ssh ssh, struct Packet *pkt)
1217 struct logblank_t blanks[4];
1222 * For outgoing packets, pkt->length represents the length of the
1223 * whole packet starting at pkt->data (including some header), and
1224 * pkt->body refers to the point within that where the log-worthy
1225 * payload begins. However, incoming packets expect pkt->length to
1226 * represent only the payload length (that is, it's measured from
1227 * pkt->body not from pkt->data). Temporarily adjust our outgoing
1228 * packet to conform to the incoming-packet semantics, so that we
1229 * can analyse it with the ssh_pkt_get functions.
1231 pkt->length -= (pkt->body - pkt->data);
1234 if (ssh->logomitdata &&
1235 (pkt->type == SSH1_CMSG_STDIN_DATA ||
1236 pkt->type == SSH1_MSG_CHANNEL_DATA)) {
1237 /* "Session data" packets - omit the data string. */
1238 if (pkt->type == SSH1_MSG_CHANNEL_DATA)
1239 ssh_pkt_getuint32(pkt); /* skip channel id */
1240 blanks[nblanks].offset = pkt->savedpos + 4;
1241 blanks[nblanks].type = PKTLOG_OMIT;
1242 ssh_pkt_getstring(pkt, &str, &slen);
1244 blanks[nblanks].len = slen;
1249 if ((pkt->type == SSH1_CMSG_AUTH_PASSWORD ||
1250 pkt->type == SSH1_CMSG_AUTH_TIS_RESPONSE ||
1251 pkt->type == SSH1_CMSG_AUTH_CCARD_RESPONSE) &&
1252 conf_get_int(ssh->conf, CONF_logomitpass)) {
1253 /* If this is a password or similar packet, blank the password(s). */
1254 blanks[nblanks].offset = 0;
1255 blanks[nblanks].len = pkt->length;
1256 blanks[nblanks].type = PKTLOG_BLANK;
1258 } else if (pkt->type == SSH1_CMSG_X11_REQUEST_FORWARDING &&
1259 conf_get_int(ssh->conf, CONF_logomitpass)) {
1261 * If this is an X forwarding request packet, blank the fake
1264 * Note that while we blank the X authentication data here, we
1265 * don't take any special action to blank the start of an X11
1266 * channel, so using MIT-MAGIC-COOKIE-1 and actually opening
1267 * an X connection without having session blanking enabled is
1268 * likely to leak your cookie into the log.
1271 ssh_pkt_getstring(pkt, &str, &slen);
1272 blanks[nblanks].offset = pkt->savedpos;
1273 blanks[nblanks].type = PKTLOG_BLANK;
1274 ssh_pkt_getstring(pkt, &str, &slen);
1276 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1281 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1282 ssh1_pkt_type(pkt->data[12]),
1283 pkt->body, pkt->length,
1284 nblanks, blanks, NULL, 0, NULL);
1287 * Undo the above adjustment of pkt->length, to put the packet
1288 * back in the state we found it.
1290 pkt->length += (pkt->body - pkt->data);
1294 * Collect incoming data in the incoming packet buffer.
1295 * Decipher and verify the packet when it is completely read.
1296 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1297 * Update the *data and *datalen variables.
1298 * Return a Packet structure when a packet is completed.
1300 static struct Packet *ssh1_rdpkt(Ssh ssh, const unsigned char **data,
1303 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
1305 crBegin(ssh->ssh1_rdpkt_crstate);
1307 st->pktin = ssh_new_packet();
1309 st->pktin->type = 0;
1310 st->pktin->length = 0;
1312 for (st->i = st->len = 0; st->i < 4; st->i++) {
1313 while ((*datalen) == 0)
1315 st->len = (st->len << 8) + **data;
1316 (*data)++, (*datalen)--;
1319 st->pad = 8 - (st->len % 8);
1320 st->biglen = st->len + st->pad;
1321 st->pktin->length = st->len - 5;
1323 if (st->biglen < 0) {
1324 bombout(("Extremely large packet length from server suggests"
1325 " data stream corruption"));
1326 ssh_free_packet(st->pktin);
1330 st->pktin->maxlen = st->biglen;
1331 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1333 st->to_read = st->biglen;
1334 st->p = st->pktin->data;
1335 while (st->to_read > 0) {
1336 st->chunk = st->to_read;
1337 while ((*datalen) == 0)
1339 if (st->chunk > (*datalen))
1340 st->chunk = (*datalen);
1341 memcpy(st->p, *data, st->chunk);
1343 *datalen -= st->chunk;
1345 st->to_read -= st->chunk;
1348 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1349 st->biglen, NULL)) {
1350 bombout(("Network attack (CRC compensation) detected!"));
1351 ssh_free_packet(st->pktin);
1356 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1358 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1359 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1360 if (st->gotcrc != st->realcrc) {
1361 bombout(("Incorrect CRC received on packet"));
1362 ssh_free_packet(st->pktin);
1366 st->pktin->body = st->pktin->data + st->pad + 1;
1368 if (ssh->v1_compressing) {
1369 unsigned char *decompblk;
1371 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1372 st->pktin->body - 1, st->pktin->length + 1,
1373 &decompblk, &decomplen)) {
1374 bombout(("Zlib decompression encountered invalid data"));
1375 ssh_free_packet(st->pktin);
1379 if (st->pktin->maxlen < st->pad + decomplen) {
1380 st->pktin->maxlen = st->pad + decomplen;
1381 st->pktin->data = sresize(st->pktin->data,
1382 st->pktin->maxlen + APIEXTRA,
1384 st->pktin->body = st->pktin->data + st->pad + 1;
1387 memcpy(st->pktin->body - 1, decompblk, decomplen);
1389 st->pktin->length = decomplen - 1;
1392 st->pktin->type = st->pktin->body[-1];
1395 * Now pktin->body and pktin->length identify the semantic content
1396 * of the packet, excluding the initial type byte.
1400 ssh1_log_incoming_packet(ssh, st->pktin);
1402 st->pktin->savedpos = 0;
1404 crFinish(st->pktin);
1407 static void ssh2_log_incoming_packet(Ssh ssh, struct Packet *pkt)
1410 struct logblank_t blanks[4];
1416 if (ssh->logomitdata &&
1417 (pkt->type == SSH2_MSG_CHANNEL_DATA ||
1418 pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)) {
1419 /* "Session data" packets - omit the data string. */
1420 ssh_pkt_getuint32(pkt); /* skip channel id */
1421 if (pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)
1422 ssh_pkt_getuint32(pkt); /* skip extended data type */
1423 blanks[nblanks].offset = pkt->savedpos + 4;
1424 blanks[nblanks].type = PKTLOG_OMIT;
1425 ssh_pkt_getstring(pkt, &str, &slen);
1427 blanks[nblanks].len = slen;
1432 log_packet(ssh->logctx, PKT_INCOMING, pkt->type,
1433 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->type),
1434 pkt->body, pkt->length, nblanks, blanks, &pkt->sequence,
1438 static void ssh2_log_outgoing_packet(Ssh ssh, struct Packet *pkt)
1441 struct logblank_t blanks[4];
1446 * For outgoing packets, pkt->length represents the length of the
1447 * whole packet starting at pkt->data (including some header), and
1448 * pkt->body refers to the point within that where the log-worthy
1449 * payload begins. However, incoming packets expect pkt->length to
1450 * represent only the payload length (that is, it's measured from
1451 * pkt->body not from pkt->data). Temporarily adjust our outgoing
1452 * packet to conform to the incoming-packet semantics, so that we
1453 * can analyse it with the ssh_pkt_get functions.
1455 pkt->length -= (pkt->body - pkt->data);
1458 if (ssh->logomitdata &&
1459 (pkt->type == SSH2_MSG_CHANNEL_DATA ||
1460 pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)) {
1461 /* "Session data" packets - omit the data string. */
1462 ssh_pkt_getuint32(pkt); /* skip channel id */
1463 if (pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)
1464 ssh_pkt_getuint32(pkt); /* skip extended data type */
1465 blanks[nblanks].offset = pkt->savedpos + 4;
1466 blanks[nblanks].type = PKTLOG_OMIT;
1467 ssh_pkt_getstring(pkt, &str, &slen);
1469 blanks[nblanks].len = slen;
1474 if (pkt->type == SSH2_MSG_USERAUTH_REQUEST &&
1475 conf_get_int(ssh->conf, CONF_logomitpass)) {
1476 /* If this is a password packet, blank the password(s). */
1478 ssh_pkt_getstring(pkt, &str, &slen);
1479 ssh_pkt_getstring(pkt, &str, &slen);
1480 ssh_pkt_getstring(pkt, &str, &slen);
1481 if (slen == 8 && !memcmp(str, "password", 8)) {
1482 ssh2_pkt_getbool(pkt);
1483 /* Blank the password field. */
1484 blanks[nblanks].offset = pkt->savedpos;
1485 blanks[nblanks].type = PKTLOG_BLANK;
1486 ssh_pkt_getstring(pkt, &str, &slen);
1488 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1490 /* If there's another password field beyond it (change of
1491 * password), blank that too. */
1492 ssh_pkt_getstring(pkt, &str, &slen);
1494 blanks[nblanks-1].len =
1495 pkt->savedpos - blanks[nblanks].offset;
1498 } else if (ssh->pkt_actx == SSH2_PKTCTX_KBDINTER &&
1499 pkt->type == SSH2_MSG_USERAUTH_INFO_RESPONSE &&
1500 conf_get_int(ssh->conf, CONF_logomitpass)) {
1501 /* If this is a keyboard-interactive response packet, blank
1504 ssh_pkt_getuint32(pkt);
1505 blanks[nblanks].offset = pkt->savedpos;
1506 blanks[nblanks].type = PKTLOG_BLANK;
1508 ssh_pkt_getstring(pkt, &str, &slen);
1512 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1514 } else if (pkt->type == SSH2_MSG_CHANNEL_REQUEST &&
1515 conf_get_int(ssh->conf, CONF_logomitpass)) {
1517 * If this is an X forwarding request packet, blank the fake
1520 * Note that while we blank the X authentication data here, we
1521 * don't take any special action to blank the start of an X11
1522 * channel, so using MIT-MAGIC-COOKIE-1 and actually opening
1523 * an X connection without having session blanking enabled is
1524 * likely to leak your cookie into the log.
1527 ssh_pkt_getuint32(pkt);
1528 ssh_pkt_getstring(pkt, &str, &slen);
1529 if (slen == 7 && !memcmp(str, "x11-req", 0)) {
1530 ssh2_pkt_getbool(pkt);
1531 ssh2_pkt_getbool(pkt);
1532 ssh_pkt_getstring(pkt, &str, &slen);
1533 blanks[nblanks].offset = pkt->savedpos;
1534 blanks[nblanks].type = PKTLOG_BLANK;
1535 ssh_pkt_getstring(pkt, &str, &slen);
1537 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1543 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1544 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]),
1545 pkt->body, pkt->length, nblanks, blanks,
1546 &ssh->v2_outgoing_sequence,
1547 pkt->downstream_id, pkt->additional_log_text);
1550 * Undo the above adjustment of pkt->length, to put the packet
1551 * back in the state we found it.
1553 pkt->length += (pkt->body - pkt->data);
1556 static struct Packet *ssh2_rdpkt(Ssh ssh, const unsigned char **data,
1559 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1561 crBegin(ssh->ssh2_rdpkt_crstate);
1563 st->pktin = ssh_new_packet();
1565 st->pktin->type = 0;
1566 st->pktin->length = 0;
1568 st->cipherblk = ssh->sccipher->blksize;
1571 if (st->cipherblk < 8)
1573 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1575 if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_IS_CBC) &&
1576 ssh->scmac && !ssh->scmac_etm) {
1578 * When dealing with a CBC-mode cipher, we want to avoid the
1579 * possibility of an attacker's tweaking the ciphertext stream
1580 * so as to cause us to feed the same block to the block
1581 * cipher more than once and thus leak information
1582 * (VU#958563). The way we do this is not to take any
1583 * decisions on the basis of anything we've decrypted until
1584 * we've verified it with a MAC. That includes the packet
1585 * length, so we just read data and check the MAC repeatedly,
1586 * and when the MAC passes, see if the length we've got is
1589 * This defence is unnecessary in OpenSSH ETM mode, because
1590 * the whole point of ETM mode is that the attacker can't
1591 * tweak the ciphertext stream at all without the MAC
1592 * detecting it before we decrypt anything.
1595 /* May as well allocate the whole lot now. */
1596 st->pktin->data = snewn(OUR_V2_PACKETLIMIT + st->maclen + APIEXTRA,
1599 /* Read an amount corresponding to the MAC. */
1600 for (st->i = 0; st->i < st->maclen; st->i++) {
1601 while ((*datalen) == 0)
1603 st->pktin->data[st->i] = *(*data)++;
1609 unsigned char seq[4];
1610 ssh->scmac->start(ssh->sc_mac_ctx);
1611 PUT_32BIT(seq, st->incoming_sequence);
1612 ssh->scmac->bytes(ssh->sc_mac_ctx, seq, 4);
1615 for (;;) { /* Once around this loop per cipher block. */
1616 /* Read another cipher-block's worth, and tack it onto the end. */
1617 for (st->i = 0; st->i < st->cipherblk; st->i++) {
1618 while ((*datalen) == 0)
1620 st->pktin->data[st->packetlen+st->maclen+st->i] = *(*data)++;
1623 /* Decrypt one more block (a little further back in the stream). */
1624 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1625 st->pktin->data + st->packetlen,
1627 /* Feed that block to the MAC. */
1628 ssh->scmac->bytes(ssh->sc_mac_ctx,
1629 st->pktin->data + st->packetlen, st->cipherblk);
1630 st->packetlen += st->cipherblk;
1631 /* See if that gives us a valid packet. */
1632 if (ssh->scmac->verresult(ssh->sc_mac_ctx,
1633 st->pktin->data + st->packetlen) &&
1634 ((st->len = toint(GET_32BIT(st->pktin->data))) ==
1637 if (st->packetlen >= OUR_V2_PACKETLIMIT) {
1638 bombout(("No valid incoming packet found"));
1639 ssh_free_packet(st->pktin);
1643 st->pktin->maxlen = st->packetlen + st->maclen;
1644 st->pktin->data = sresize(st->pktin->data,
1645 st->pktin->maxlen + APIEXTRA,
1647 } else if (ssh->scmac && ssh->scmac_etm) {
1648 st->pktin->data = snewn(4 + APIEXTRA, unsigned char);
1651 * OpenSSH encrypt-then-MAC mode: the packet length is
1652 * unencrypted, unless the cipher supports length encryption.
1654 for (st->i = st->len = 0; st->i < 4; st->i++) {
1655 while ((*datalen) == 0)
1657 st->pktin->data[st->i] = *(*data)++;
1660 /* Cipher supports length decryption, so do it */
1661 if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_SEPARATE_LENGTH)) {
1662 /* Keep the packet the same though, so the MAC passes */
1663 unsigned char len[4];
1664 memcpy(len, st->pktin->data, 4);
1665 ssh->sccipher->decrypt_length(ssh->sc_cipher_ctx, len, 4, st->incoming_sequence);
1666 st->len = toint(GET_32BIT(len));
1668 st->len = toint(GET_32BIT(st->pktin->data));
1672 * _Completely_ silly lengths should be stomped on before they
1673 * do us any more damage.
1675 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1676 st->len % st->cipherblk != 0) {
1677 bombout(("Incoming packet length field was garbled"));
1678 ssh_free_packet(st->pktin);
1683 * So now we can work out the total packet length.
1685 st->packetlen = st->len + 4;
1688 * Allocate memory for the rest of the packet.
1690 st->pktin->maxlen = st->packetlen + st->maclen;
1691 st->pktin->data = sresize(st->pktin->data,
1692 st->pktin->maxlen + APIEXTRA,
1696 * Read the remainder of the packet.
1698 for (st->i = 4; st->i < st->packetlen + st->maclen; st->i++) {
1699 while ((*datalen) == 0)
1701 st->pktin->data[st->i] = *(*data)++;
1709 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1710 st->len + 4, st->incoming_sequence)) {
1711 bombout(("Incorrect MAC received on packet"));
1712 ssh_free_packet(st->pktin);
1716 /* Decrypt everything between the length field and the MAC. */
1718 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1719 st->pktin->data + 4,
1722 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1725 * Acquire and decrypt the first block of the packet. This will
1726 * contain the length and padding details.
1728 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1729 while ((*datalen) == 0)
1731 st->pktin->data[st->i] = *(*data)++;
1736 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1737 st->pktin->data, st->cipherblk);
1740 * Now get the length figure.
1742 st->len = toint(GET_32BIT(st->pktin->data));
1745 * _Completely_ silly lengths should be stomped on before they
1746 * do us any more damage.
1748 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1749 (st->len + 4) % st->cipherblk != 0) {
1750 bombout(("Incoming packet was garbled on decryption"));
1751 ssh_free_packet(st->pktin);
1756 * So now we can work out the total packet length.
1758 st->packetlen = st->len + 4;
1761 * Allocate memory for the rest of the packet.
1763 st->pktin->maxlen = st->packetlen + st->maclen;
1764 st->pktin->data = sresize(st->pktin->data,
1765 st->pktin->maxlen + APIEXTRA,
1769 * Read and decrypt the remainder of the packet.
1771 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1773 while ((*datalen) == 0)
1775 st->pktin->data[st->i] = *(*data)++;
1778 /* Decrypt everything _except_ the MAC. */
1780 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1781 st->pktin->data + st->cipherblk,
1782 st->packetlen - st->cipherblk);
1788 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1789 st->len + 4, st->incoming_sequence)) {
1790 bombout(("Incorrect MAC received on packet"));
1791 ssh_free_packet(st->pktin);
1795 /* Get and sanity-check the amount of random padding. */
1796 st->pad = st->pktin->data[4];
1797 if (st->pad < 4 || st->len - st->pad < 1) {
1798 bombout(("Invalid padding length on received packet"));
1799 ssh_free_packet(st->pktin);
1803 * This enables us to deduce the payload length.
1805 st->payload = st->len - st->pad - 1;
1807 st->pktin->length = st->payload + 5;
1808 st->pktin->encrypted_len = st->packetlen;
1810 st->pktin->sequence = st->incoming_sequence++;
1812 st->pktin->length = st->packetlen - st->pad;
1813 assert(st->pktin->length >= 0);
1816 * Decompress packet payload.
1819 unsigned char *newpayload;
1822 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1823 st->pktin->data + 5, st->pktin->length - 5,
1824 &newpayload, &newlen)) {
1825 if (st->pktin->maxlen < newlen + 5) {
1826 st->pktin->maxlen = newlen + 5;
1827 st->pktin->data = sresize(st->pktin->data,
1828 st->pktin->maxlen + APIEXTRA,
1831 st->pktin->length = 5 + newlen;
1832 memcpy(st->pktin->data + 5, newpayload, newlen);
1838 * pktin->body and pktin->length should identify the semantic
1839 * content of the packet, excluding the initial type byte.
1841 st->pktin->type = st->pktin->data[5];
1842 st->pktin->body = st->pktin->data + 6;
1843 st->pktin->length -= 6;
1844 assert(st->pktin->length >= 0); /* one last double-check */
1847 ssh2_log_incoming_packet(ssh, st->pktin);
1849 st->pktin->savedpos = 0;
1851 crFinish(st->pktin);
1854 static struct Packet *ssh2_bare_connection_rdpkt(Ssh ssh,
1855 const unsigned char **data,
1858 struct rdpkt2_bare_state_tag *st = &ssh->rdpkt2_bare_state;
1860 crBegin(ssh->ssh2_bare_rdpkt_crstate);
1863 * Read the packet length field.
1865 for (st->i = 0; st->i < 4; st->i++) {
1866 while ((*datalen) == 0)
1868 st->length[st->i] = *(*data)++;
1872 st->packetlen = toint(GET_32BIT_MSB_FIRST(st->length));
1873 if (st->packetlen <= 0 || st->packetlen >= OUR_V2_PACKETLIMIT) {
1874 bombout(("Invalid packet length received"));
1878 st->pktin = ssh_new_packet();
1879 st->pktin->data = snewn(st->packetlen, unsigned char);
1881 st->pktin->encrypted_len = st->packetlen;
1883 st->pktin->sequence = st->incoming_sequence++;
1886 * Read the remainder of the packet.
1888 for (st->i = 0; st->i < st->packetlen; st->i++) {
1889 while ((*datalen) == 0)
1891 st->pktin->data[st->i] = *(*data)++;
1896 * pktin->body and pktin->length should identify the semantic
1897 * content of the packet, excluding the initial type byte.
1899 st->pktin->type = st->pktin->data[0];
1900 st->pktin->body = st->pktin->data + 1;
1901 st->pktin->length = st->packetlen - 1;
1904 * Log incoming packet, possibly omitting sensitive fields.
1907 ssh2_log_incoming_packet(ssh, st->pktin);
1909 st->pktin->savedpos = 0;
1911 crFinish(st->pktin);
1914 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1916 int pad, biglen, i, pktoffs;
1920 * XXX various versions of SC (including 8.8.4) screw up the
1921 * register allocation in this function and use the same register
1922 * (D6) for len and as a temporary, with predictable results. The
1923 * following sledgehammer prevents this.
1930 ssh1_log_outgoing_packet(ssh, pkt);
1932 if (ssh->v1_compressing) {
1933 unsigned char *compblk;
1935 zlib_compress_block(ssh->cs_comp_ctx,
1936 pkt->data + 12, pkt->length - 12,
1937 &compblk, &complen);
1938 ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */
1939 memcpy(pkt->data + 12, compblk, complen);
1941 pkt->length = complen + 12;
1944 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1946 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
1947 pad = 8 - (len % 8);
1949 biglen = len + pad; /* len(padding+type+data+CRC) */
1951 for (i = pktoffs; i < 4+8; i++)
1952 pkt->data[i] = random_byte();
1953 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1954 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1955 PUT_32BIT(pkt->data + pktoffs, len);
1958 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1959 pkt->data + pktoffs + 4, biglen);
1961 if (offset_p) *offset_p = pktoffs;
1962 return biglen + 4; /* len(length+padding+type+data+CRC) */
1965 static int s_write(Ssh ssh, void *data, int len)
1968 log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len,
1969 0, NULL, NULL, 0, NULL);
1972 return sk_write(ssh->s, (char *)data, len);
1975 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1977 int len, backlog, offset;
1978 len = s_wrpkt_prepare(ssh, pkt, &offset);
1979 backlog = s_write(ssh, pkt->data + offset, len);
1980 if (backlog > SSH_MAX_BACKLOG)
1981 ssh_throttle_all(ssh, 1, backlog);
1982 ssh_free_packet(pkt);
1985 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1988 len = s_wrpkt_prepare(ssh, pkt, &offset);
1989 if (ssh->deferred_len + len > ssh->deferred_size) {
1990 ssh->deferred_size = ssh->deferred_len + len + 128;
1991 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1995 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1996 pkt->data + offset, len);
1997 ssh->deferred_len += len;
1998 ssh_free_packet(pkt);
2002 * Construct a SSH-1 packet with the specified contents.
2003 * (This all-at-once interface used to be the only one, but now SSH-1
2004 * packets can also be constructed incrementally.)
2006 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
2012 pkt = ssh1_pkt_init(pkttype);
2014 while ((argtype = va_arg(ap, int)) != PKT_END) {
2015 unsigned char *argp, argchar;
2017 unsigned long argint;
2020 /* Actual fields in the packet */
2022 argint = va_arg(ap, int);
2023 ssh_pkt_adduint32(pkt, argint);
2026 argchar = (unsigned char) va_arg(ap, int);
2027 ssh_pkt_addbyte(pkt, argchar);
2030 argp = va_arg(ap, unsigned char *);
2031 arglen = va_arg(ap, int);
2032 ssh_pkt_adddata(pkt, argp, arglen);
2035 sargp = va_arg(ap, char *);
2036 ssh_pkt_addstring(pkt, sargp);
2039 bn = va_arg(ap, Bignum);
2040 ssh1_pkt_addmp(pkt, bn);
2048 static void send_packet(Ssh ssh, int pkttype, ...)
2052 va_start(ap, pkttype);
2053 pkt = construct_packet(ssh, pkttype, ap);
2058 static void defer_packet(Ssh ssh, int pkttype, ...)
2062 va_start(ap, pkttype);
2063 pkt = construct_packet(ssh, pkttype, ap);
2065 s_wrpkt_defer(ssh, pkt);
2068 static int ssh_versioncmp(const char *a, const char *b)
2071 unsigned long av, bv;
2073 av = strtoul(a, &ae, 10);
2074 bv = strtoul(b, &be, 10);
2076 return (av < bv ? -1 : +1);
2081 av = strtoul(ae, &ae, 10);
2082 bv = strtoul(be, &be, 10);
2084 return (av < bv ? -1 : +1);
2089 * Utility routines for putting an SSH-protocol `string' and
2090 * `uint32' into a hash state.
2092 static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
2094 unsigned char lenblk[4];
2095 PUT_32BIT(lenblk, len);
2096 h->bytes(s, lenblk, 4);
2097 h->bytes(s, str, len);
2100 static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
2102 unsigned char intblk[4];
2103 PUT_32BIT(intblk, i);
2104 h->bytes(s, intblk, 4);
2108 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
2110 static void ssh_pkt_ensure(struct Packet *pkt, int length)
2112 if (pkt->maxlen < length) {
2113 unsigned char *body = pkt->body;
2114 int offset = body ? body - pkt->data : 0;
2115 pkt->maxlen = length + 256;
2116 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
2117 if (body) pkt->body = pkt->data + offset;
2120 static void ssh_pkt_adddata(struct Packet *pkt, const void *data, int len)
2123 ssh_pkt_ensure(pkt, pkt->length);
2124 memcpy(pkt->data + pkt->length - len, data, len);
2126 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
2128 ssh_pkt_adddata(pkt, &byte, 1);
2130 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
2132 ssh_pkt_adddata(pkt, &value, 1);
2134 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
2137 PUT_32BIT(x, value);
2138 ssh_pkt_adddata(pkt, x, 4);
2140 static void ssh_pkt_addstring_start(struct Packet *pkt)
2142 ssh_pkt_adduint32(pkt, 0);
2143 pkt->savedpos = pkt->length;
2145 static void ssh_pkt_addstring_data(struct Packet *pkt, const char *data,
2148 ssh_pkt_adddata(pkt, data, len);
2149 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
2151 static void ssh_pkt_addstring_str(struct Packet *pkt, const char *data)
2153 ssh_pkt_addstring_data(pkt, data, strlen(data));
2155 static void ssh_pkt_addstring(struct Packet *pkt, const char *data)
2157 ssh_pkt_addstring_start(pkt);
2158 ssh_pkt_addstring_str(pkt, data);
2160 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
2162 int len = ssh1_bignum_length(b);
2163 unsigned char *data = snewn(len, unsigned char);
2164 (void) ssh1_write_bignum(data, b);
2165 ssh_pkt_adddata(pkt, data, len);
2168 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
2171 int i, n = (bignum_bitcount(b) + 7) / 8;
2172 p = snewn(n + 1, unsigned char);
2174 for (i = 1; i <= n; i++)
2175 p[i] = bignum_byte(b, n - i);
2177 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
2179 memmove(p, p + i, n + 1 - i);
2183 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
2187 p = ssh2_mpint_fmt(b, &len);
2188 ssh_pkt_addstring_start(pkt);
2189 ssh_pkt_addstring_data(pkt, (char *)p, len);
2193 static struct Packet *ssh1_pkt_init(int pkt_type)
2195 struct Packet *pkt = ssh_new_packet();
2196 pkt->length = 4 + 8; /* space for length + max padding */
2197 ssh_pkt_addbyte(pkt, pkt_type);
2198 pkt->body = pkt->data + pkt->length;
2199 pkt->type = pkt_type;
2200 pkt->downstream_id = 0;
2201 pkt->additional_log_text = NULL;
2205 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
2206 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
2207 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
2208 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
2209 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
2210 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
2211 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
2212 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
2213 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
2215 static struct Packet *ssh2_pkt_init(int pkt_type)
2217 struct Packet *pkt = ssh_new_packet();
2218 pkt->length = 5; /* space for packet length + padding length */
2220 pkt->type = pkt_type;
2221 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
2222 pkt->body = pkt->data + pkt->length; /* after packet type */
2223 pkt->downstream_id = 0;
2224 pkt->additional_log_text = NULL;
2229 * Construct an SSH-2 final-form packet: compress it, encrypt it,
2230 * put the MAC on it. Final packet, ready to be sent, is stored in
2231 * pkt->data. Total length is returned.
2233 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
2235 int cipherblk, maclen, padding, unencrypted_prefix, i;
2238 ssh2_log_outgoing_packet(ssh, pkt);
2240 if (ssh->bare_connection) {
2242 * Trivial packet construction for the bare connection
2245 PUT_32BIT(pkt->data + 1, pkt->length - 5);
2246 pkt->body = pkt->data + 1;
2247 ssh->v2_outgoing_sequence++; /* only for diagnostics, really */
2248 return pkt->length - 1;
2252 * Compress packet payload.
2255 unsigned char *newpayload;
2258 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
2260 &newpayload, &newlen)) {
2262 ssh2_pkt_adddata(pkt, newpayload, newlen);
2268 * Add padding. At least four bytes, and must also bring total
2269 * length (minus MAC) up to a multiple of the block size.
2270 * If pkt->forcepad is set, make sure the packet is at least that size
2273 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
2274 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
2276 unencrypted_prefix = (ssh->csmac && ssh->csmac_etm) ? 4 : 0;
2277 if (pkt->length + padding < pkt->forcepad)
2278 padding = pkt->forcepad - pkt->length;
2280 (cipherblk - (pkt->length - unencrypted_prefix + padding) % cipherblk)
2282 assert(padding <= 255);
2283 maclen = ssh->csmac ? ssh->csmac->len : 0;
2284 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
2285 pkt->data[4] = padding;
2286 for (i = 0; i < padding; i++)
2287 pkt->data[pkt->length + i] = random_byte();
2288 PUT_32BIT(pkt->data, pkt->length + padding - 4);
2290 /* Encrypt length if the scheme requires it */
2291 if (ssh->cscipher && (ssh->cscipher->flags & SSH_CIPHER_SEPARATE_LENGTH)) {
2292 ssh->cscipher->encrypt_length(ssh->cs_cipher_ctx, pkt->data, 4,
2293 ssh->v2_outgoing_sequence);
2296 if (ssh->csmac && ssh->csmac_etm) {
2298 * OpenSSH-defined encrypt-then-MAC protocol.
2301 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
2302 pkt->data + 4, pkt->length + padding - 4);
2303 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
2304 pkt->length + padding,
2305 ssh->v2_outgoing_sequence);
2308 * SSH-2 standard protocol.
2311 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
2312 pkt->length + padding,
2313 ssh->v2_outgoing_sequence);
2315 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
2316 pkt->data, pkt->length + padding);
2319 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
2320 pkt->encrypted_len = pkt->length + padding;
2322 /* Ready-to-send packet starts at pkt->data. We return length. */
2323 pkt->body = pkt->data;
2324 return pkt->length + padding + maclen;
2328 * Routines called from the main SSH code to send packets. There
2329 * are quite a few of these, because we have two separate
2330 * mechanisms for delaying the sending of packets:
2332 * - In order to send an IGNORE message and a password message in
2333 * a single fixed-length blob, we require the ability to
2334 * concatenate the encrypted forms of those two packets _into_ a
2335 * single blob and then pass it to our <network.h> transport
2336 * layer in one go. Hence, there's a deferment mechanism which
2337 * works after packet encryption.
2339 * - In order to avoid sending any connection-layer messages
2340 * during repeat key exchange, we have to queue up any such
2341 * outgoing messages _before_ they are encrypted (and in
2342 * particular before they're allocated sequence numbers), and
2343 * then send them once we've finished.
2345 * I call these mechanisms `defer' and `queue' respectively, so as
2346 * to distinguish them reasonably easily.
2348 * The functions send_noqueue() and defer_noqueue() free the packet
2349 * structure they are passed. Every outgoing packet goes through
2350 * precisely one of these functions in its life; packets passed to
2351 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
2352 * these or get queued, and then when the queue is later emptied
2353 * the packets are all passed to defer_noqueue().
2355 * When using a CBC-mode cipher, it's necessary to ensure that an
2356 * attacker can't provide data to be encrypted using an IV that they
2357 * know. We ensure this by prefixing each packet that might contain
2358 * user data with an SSH_MSG_IGNORE. This is done using the deferral
2359 * mechanism, so in this case send_noqueue() ends up redirecting to
2360 * defer_noqueue(). If you don't like this inefficiency, don't use
2364 static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
2365 static void ssh_pkt_defersend(Ssh);
2368 * Send an SSH-2 packet immediately, without queuing or deferring.
2370 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
2374 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
2375 /* We need to send two packets, so use the deferral mechanism. */
2376 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2377 ssh_pkt_defersend(ssh);
2380 len = ssh2_pkt_construct(ssh, pkt);
2381 backlog = s_write(ssh, pkt->body, len);
2382 if (backlog > SSH_MAX_BACKLOG)
2383 ssh_throttle_all(ssh, 1, backlog);
2385 ssh->outgoing_data_size += pkt->encrypted_len;
2386 if (!ssh->kex_in_progress &&
2387 !ssh->bare_connection &&
2388 ssh->max_data_size != 0 &&
2389 ssh->outgoing_data_size > ssh->max_data_size)
2390 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2392 ssh_free_packet(pkt);
2396 * Defer an SSH-2 packet.
2398 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
2401 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
2402 ssh->deferred_len == 0 && !noignore &&
2403 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2405 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2406 * get encrypted with a known IV.
2408 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2409 ssh2_pkt_addstring_start(ipkt);
2410 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
2412 len = ssh2_pkt_construct(ssh, pkt);
2413 if (ssh->deferred_len + len > ssh->deferred_size) {
2414 ssh->deferred_size = ssh->deferred_len + len + 128;
2415 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2419 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->body, len);
2420 ssh->deferred_len += len;
2421 ssh->deferred_data_size += pkt->encrypted_len;
2422 ssh_free_packet(pkt);
2426 * Queue an SSH-2 packet.
2428 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
2430 assert(ssh->queueing);
2432 if (ssh->queuelen >= ssh->queuesize) {
2433 ssh->queuesize = ssh->queuelen + 32;
2434 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
2437 ssh->queue[ssh->queuelen++] = pkt;
2441 * Either queue or send a packet, depending on whether queueing is
2444 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
2447 ssh2_pkt_queue(ssh, pkt);
2449 ssh2_pkt_send_noqueue(ssh, pkt);
2453 * Either queue or defer a packet, depending on whether queueing is
2456 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
2459 ssh2_pkt_queue(ssh, pkt);
2461 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2465 * Send the whole deferred data block constructed by
2466 * ssh2_pkt_defer() or SSH-1's defer_packet().
2468 * The expected use of the defer mechanism is that you call
2469 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2470 * not currently queueing, this simply sets up deferred_send_data
2471 * and then sends it. If we _are_ currently queueing, the calls to
2472 * ssh2_pkt_defer() put the deferred packets on to the queue
2473 * instead, and therefore ssh_pkt_defersend() has no deferred data
2474 * to send. Hence, there's no need to make it conditional on
2477 static void ssh_pkt_defersend(Ssh ssh)
2480 backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
2481 ssh->deferred_len = ssh->deferred_size = 0;
2482 sfree(ssh->deferred_send_data);
2483 ssh->deferred_send_data = NULL;
2484 if (backlog > SSH_MAX_BACKLOG)
2485 ssh_throttle_all(ssh, 1, backlog);
2487 ssh->outgoing_data_size += ssh->deferred_data_size;
2488 if (!ssh->kex_in_progress &&
2489 !ssh->bare_connection &&
2490 ssh->max_data_size != 0 &&
2491 ssh->outgoing_data_size > ssh->max_data_size)
2492 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2493 ssh->deferred_data_size = 0;
2497 * Send a packet whose length needs to be disguised (typically
2498 * passwords or keyboard-interactive responses).
2500 static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
2506 * The simplest way to do this is to adjust the
2507 * variable-length padding field in the outgoing packet.
2509 * Currently compiled out, because some Cisco SSH servers
2510 * don't like excessively padded packets (bah, why's it
2513 pkt->forcepad = padsize;
2514 ssh2_pkt_send(ssh, pkt);
2519 * If we can't do that, however, an alternative approach is
2520 * to use the pkt_defer mechanism to bundle the packet
2521 * tightly together with an SSH_MSG_IGNORE such that their
2522 * combined length is a constant. So first we construct the
2523 * final form of this packet and defer its sending.
2525 ssh2_pkt_defer(ssh, pkt);
2528 * Now construct an SSH_MSG_IGNORE which includes a string
2529 * that's an exact multiple of the cipher block size. (If
2530 * the cipher is NULL so that the block size is
2531 * unavailable, we don't do this trick at all, because we
2532 * gain nothing by it.)
2534 if (ssh->cscipher &&
2535 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2538 stringlen = (256 - ssh->deferred_len);
2539 stringlen += ssh->cscipher->blksize - 1;
2540 stringlen -= (stringlen % ssh->cscipher->blksize);
2543 * Temporarily disable actual compression, so we
2544 * can guarantee to get this string exactly the
2545 * length we want it. The compression-disabling
2546 * routine should return an integer indicating how
2547 * many bytes we should adjust our string length
2551 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
2553 pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2554 ssh2_pkt_addstring_start(pkt);
2555 for (i = 0; i < stringlen; i++) {
2556 char c = (char) random_byte();
2557 ssh2_pkt_addstring_data(pkt, &c, 1);
2559 ssh2_pkt_defer(ssh, pkt);
2561 ssh_pkt_defersend(ssh);
2566 * Send all queued SSH-2 packets. We send them by means of
2567 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2568 * packets that needed to be lumped together.
2570 static void ssh2_pkt_queuesend(Ssh ssh)
2574 assert(!ssh->queueing);
2576 for (i = 0; i < ssh->queuelen; i++)
2577 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
2580 ssh_pkt_defersend(ssh);
2584 void bndebug(char *string, Bignum b)
2588 p = ssh2_mpint_fmt(b, &len);
2589 debug(("%s", string));
2590 for (i = 0; i < len; i++)
2591 debug((" %02x", p[i]));
2597 static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
2601 p = ssh2_mpint_fmt(b, &len);
2602 hash_string(h, s, p, len);
2607 * Packet decode functions for both SSH-1 and SSH-2.
2609 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
2611 unsigned long value;
2612 if (pkt->length - pkt->savedpos < 4)
2613 return 0; /* arrgh, no way to decline (FIXME?) */
2614 value = GET_32BIT(pkt->body + pkt->savedpos);
2618 static int ssh2_pkt_getbool(struct Packet *pkt)
2620 unsigned long value;
2621 if (pkt->length - pkt->savedpos < 1)
2622 return 0; /* arrgh, no way to decline (FIXME?) */
2623 value = pkt->body[pkt->savedpos] != 0;
2627 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
2632 if (pkt->length - pkt->savedpos < 4)
2634 len = toint(GET_32BIT(pkt->body + pkt->savedpos));
2639 if (pkt->length - pkt->savedpos < *length)
2641 *p = (char *)(pkt->body + pkt->savedpos);
2642 pkt->savedpos += *length;
2644 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
2646 if (pkt->length - pkt->savedpos < length)
2648 pkt->savedpos += length;
2649 return pkt->body + (pkt->savedpos - length);
2651 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2652 const unsigned char **keystr)
2656 j = makekey(pkt->body + pkt->savedpos,
2657 pkt->length - pkt->savedpos,
2664 assert(pkt->savedpos < pkt->length);
2668 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2673 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2674 pkt->length - pkt->savedpos, &b);
2682 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2688 ssh_pkt_getstring(pkt, &p, &length);
2693 b = bignum_from_bytes((unsigned char *)p, length);
2698 * Helper function to add an SSH-2 signature blob to a packet.
2699 * Expects to be shown the public key blob as well as the signature
2700 * blob. Normally works just like ssh2_pkt_addstring, but will
2701 * fiddle with the signature packet if necessary for
2702 * BUG_SSH2_RSA_PADDING.
2704 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2705 void *pkblob_v, int pkblob_len,
2706 void *sigblob_v, int sigblob_len)
2708 unsigned char *pkblob = (unsigned char *)pkblob_v;
2709 unsigned char *sigblob = (unsigned char *)sigblob_v;
2711 /* dmemdump(pkblob, pkblob_len); */
2712 /* dmemdump(sigblob, sigblob_len); */
2715 * See if this is in fact an ssh-rsa signature and a buggy
2716 * server; otherwise we can just do this the easy way.
2718 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) && pkblob_len > 4+7+4 &&
2719 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2720 int pos, len, siglen;
2723 * Find the byte length of the modulus.
2726 pos = 4+7; /* skip over "ssh-rsa" */
2727 len = toint(GET_32BIT(pkblob+pos)); /* get length of exponent */
2728 if (len < 0 || len > pkblob_len - pos - 4)
2730 pos += 4 + len; /* skip over exponent */
2731 if (pkblob_len - pos < 4)
2733 len = toint(GET_32BIT(pkblob+pos)); /* find length of modulus */
2734 if (len < 0 || len > pkblob_len - pos - 4)
2736 pos += 4; /* find modulus itself */
2737 while (len > 0 && pkblob[pos] == 0)
2739 /* debug(("modulus length is %d\n", len)); */
2742 * Now find the signature integer.
2744 pos = 4+7; /* skip over "ssh-rsa" */
2745 if (sigblob_len < pos+4)
2747 siglen = toint(GET_32BIT(sigblob+pos));
2748 if (siglen != sigblob_len - pos - 4)
2750 /* debug(("signature length is %d\n", siglen)); */
2752 if (len != siglen) {
2753 unsigned char newlen[4];
2754 ssh2_pkt_addstring_start(pkt);
2755 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2756 /* dmemdump(sigblob, pos); */
2757 pos += 4; /* point to start of actual sig */
2758 PUT_32BIT(newlen, len);
2759 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2760 /* dmemdump(newlen, 4); */
2762 while (len-- > siglen) {
2763 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2764 /* dmemdump(newlen, 1); */
2766 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2767 /* dmemdump(sigblob+pos, siglen); */
2771 /* Otherwise fall through and do it the easy way. We also come
2772 * here as a fallback if we discover above that the key blob
2773 * is misformatted in some way. */
2777 ssh2_pkt_addstring_start(pkt);
2778 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2782 * Examine the remote side's version string and compare it against
2783 * a list of known buggy implementations.
2785 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2787 char *imp; /* pointer to implementation part */
2789 imp += strcspn(imp, "-");
2791 imp += strcspn(imp, "-");
2794 ssh->remote_bugs = 0;
2797 * General notes on server version strings:
2798 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2799 * here -- in particular, we've heard of one that's perfectly happy
2800 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2801 * so we can't distinguish them.
2803 if (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == FORCE_ON ||
2804 (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == AUTO &&
2805 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2806 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2807 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2808 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2810 * These versions don't support SSH1_MSG_IGNORE, so we have
2811 * to use a different defence against password length
2814 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2815 logevent("We believe remote version has SSH-1 ignore bug");
2818 if (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == FORCE_ON ||
2819 (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == AUTO &&
2820 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2822 * These versions need a plain password sent; they can't
2823 * handle having a null and a random length of data after
2826 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2827 logevent("We believe remote version needs a plain SSH-1 password");
2830 if (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == FORCE_ON ||
2831 (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == AUTO &&
2832 (!strcmp(imp, "Cisco-1.25")))) {
2834 * These versions apparently have no clue whatever about
2835 * RSA authentication and will panic and die if they see
2836 * an AUTH_RSA message.
2838 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2839 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2842 if (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == FORCE_ON ||
2843 (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == AUTO &&
2844 !wc_match("* VShell", imp) &&
2845 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2846 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2847 wc_match("2.1 *", imp)))) {
2849 * These versions have the HMAC bug.
2851 ssh->remote_bugs |= BUG_SSH2_HMAC;
2852 logevent("We believe remote version has SSH-2 HMAC bug");
2855 if (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == FORCE_ON ||
2856 (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == AUTO &&
2857 !wc_match("* VShell", imp) &&
2858 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2860 * These versions have the key-derivation bug (failing to
2861 * include the literal shared secret in the hashes that
2862 * generate the keys).
2864 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2865 logevent("We believe remote version has SSH-2 key-derivation bug");
2868 if (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == FORCE_ON ||
2869 (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == AUTO &&
2870 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2871 wc_match("OpenSSH_3.[0-2]*", imp) ||
2872 wc_match("mod_sftp/0.[0-8]*", imp) ||
2873 wc_match("mod_sftp/0.9.[0-8]", imp)))) {
2875 * These versions have the SSH-2 RSA padding bug.
2877 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2878 logevent("We believe remote version has SSH-2 RSA padding bug");
2881 if (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == FORCE_ON ||
2882 (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == AUTO &&
2883 wc_match("OpenSSH_2.[0-2]*", imp))) {
2885 * These versions have the SSH-2 session-ID bug in
2886 * public-key authentication.
2888 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2889 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2892 if (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == FORCE_ON ||
2893 (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == AUTO &&
2894 (wc_match("DigiSSH_2.0", imp) ||
2895 wc_match("OpenSSH_2.[0-4]*", imp) ||
2896 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2897 wc_match("Sun_SSH_1.0", imp) ||
2898 wc_match("Sun_SSH_1.0.1", imp) ||
2899 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2900 wc_match("WeOnlyDo-*", imp)))) {
2902 * These versions have the SSH-2 rekey bug.
2904 ssh->remote_bugs |= BUG_SSH2_REKEY;
2905 logevent("We believe remote version has SSH-2 rekey bug");
2908 if (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == FORCE_ON ||
2909 (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == AUTO &&
2910 (wc_match("1.36_sshlib GlobalSCAPE", imp) ||
2911 wc_match("1.36 sshlib: GlobalScape", imp)))) {
2913 * This version ignores our makpkt and needs to be throttled.
2915 ssh->remote_bugs |= BUG_SSH2_MAXPKT;
2916 logevent("We believe remote version ignores SSH-2 maximum packet size");
2919 if (conf_get_int(ssh->conf, CONF_sshbug_ignore2) == FORCE_ON) {
2921 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2922 * none detected automatically.
2924 ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE;
2925 logevent("We believe remote version has SSH-2 ignore bug");
2928 if (conf_get_int(ssh->conf, CONF_sshbug_oldgex2) == FORCE_ON ||
2929 (conf_get_int(ssh->conf, CONF_sshbug_oldgex2) == AUTO &&
2930 (wc_match("OpenSSH_2.[235]*", imp)))) {
2932 * These versions only support the original (pre-RFC4419)
2933 * SSH-2 GEX request, and disconnect with a protocol error if
2934 * we use the newer version.
2936 ssh->remote_bugs |= BUG_SSH2_OLDGEX;
2937 logevent("We believe remote version has outdated SSH-2 GEX");
2940 if (conf_get_int(ssh->conf, CONF_sshbug_winadj) == FORCE_ON) {
2942 * Servers that don't support our winadj request for one
2943 * reason or another. Currently, none detected automatically.
2945 ssh->remote_bugs |= BUG_CHOKES_ON_WINADJ;
2946 logevent("We believe remote version has winadj bug");
2949 if (conf_get_int(ssh->conf, CONF_sshbug_chanreq) == FORCE_ON ||
2950 (conf_get_int(ssh->conf, CONF_sshbug_chanreq) == AUTO &&
2951 (wc_match("OpenSSH_[2-5].*", imp) ||
2952 wc_match("OpenSSH_6.[0-6]*", imp) ||
2953 wc_match("dropbear_0.[2-4][0-9]*", imp) ||
2954 wc_match("dropbear_0.5[01]*", imp)))) {
2956 * These versions have the SSH-2 channel request bug.
2957 * OpenSSH 6.7 and above do not:
2958 * https://bugzilla.mindrot.org/show_bug.cgi?id=1818
2959 * dropbear_0.52 and above do not:
2960 * https://secure.ucc.asn.au/hg/dropbear/rev/cd02449b709c
2962 ssh->remote_bugs |= BUG_SENDS_LATE_REQUEST_REPLY;
2963 logevent("We believe remote version has SSH-2 channel request bug");
2968 * The `software version' part of an SSH version string is required
2969 * to contain no spaces or minus signs.
2971 static void ssh_fix_verstring(char *str)
2973 /* Eat "<protoversion>-". */
2974 while (*str && *str != '-') str++;
2975 assert(*str == '-'); str++;
2977 /* Convert minus signs and spaces in the remaining string into
2980 if (*str == '-' || *str == ' ')
2987 * Send an appropriate SSH version string.
2989 static void ssh_send_verstring(Ssh ssh, const char *protoname, char *svers)
2993 if (ssh->version == 2) {
2995 * Construct a v2 version string.
2997 verstring = dupprintf("%s2.0-%s\015\012", protoname, sshver);
3000 * Construct a v1 version string.
3002 assert(!strcmp(protoname, "SSH-")); /* no v1 bare connection protocol */
3003 verstring = dupprintf("SSH-%s-%s\012",
3004 (ssh_versioncmp(svers, "1.5") <= 0 ?
3009 ssh_fix_verstring(verstring + strlen(protoname));
3011 if (ssh->version == 2) {
3014 * Record our version string.
3016 len = strcspn(verstring, "\015\012");
3017 ssh->v_c = snewn(len + 1, char);
3018 memcpy(ssh->v_c, verstring, len);
3022 logeventf(ssh, "We claim version: %.*s",
3023 strcspn(verstring, "\015\012"), verstring);
3024 s_write(ssh, verstring, strlen(verstring));
3028 static int do_ssh_init(Ssh ssh, unsigned char c)
3030 static const char protoname[] = "SSH-";
3032 struct do_ssh_init_state {
3041 crState(do_ssh_init_state);
3045 /* Search for a line beginning with the protocol name prefix in
3048 for (s->i = 0; protoname[s->i]; s->i++) {
3049 if ((char)c != protoname[s->i]) goto no;
3059 s->vstrsize = sizeof(protoname) + 16;
3060 s->vstring = snewn(s->vstrsize, char);
3061 strcpy(s->vstring, protoname);
3062 s->vslen = strlen(protoname);
3065 if (s->vslen >= s->vstrsize - 1) {
3067 s->vstring = sresize(s->vstring, s->vstrsize, char);
3069 s->vstring[s->vslen++] = c;
3072 s->version[s->i] = '\0';
3074 } else if (s->i < sizeof(s->version) - 1)
3075 s->version[s->i++] = c;
3076 } else if (c == '\012')
3078 crReturn(1); /* get another char */
3081 ssh->agentfwd_enabled = FALSE;
3082 ssh->rdpkt2_state.incoming_sequence = 0;
3084 s->vstring[s->vslen] = 0;
3085 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
3086 logeventf(ssh, "Server version: %s", s->vstring);
3087 ssh_detect_bugs(ssh, s->vstring);
3090 * Decide which SSH protocol version to support.
3093 /* Anything strictly below "2.0" means protocol 1 is supported. */
3094 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
3095 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
3096 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
3098 if (conf_get_int(ssh->conf, CONF_sshprot) == 0 && !s->proto1) {
3099 bombout(("SSH protocol version 1 required by configuration but "
3100 "not provided by server"));
3103 if (conf_get_int(ssh->conf, CONF_sshprot) == 3 && !s->proto2) {
3104 bombout(("SSH protocol version 2 required by configuration but "
3105 "not provided by server"));
3109 if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1))
3114 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
3116 /* Send the version string, if we haven't already */
3117 if (conf_get_int(ssh->conf, CONF_sshprot) != 3)
3118 ssh_send_verstring(ssh, protoname, s->version);
3120 if (ssh->version == 2) {
3123 * Record their version string.
3125 len = strcspn(s->vstring, "\015\012");
3126 ssh->v_s = snewn(len + 1, char);
3127 memcpy(ssh->v_s, s->vstring, len);
3131 * Initialise SSH-2 protocol.
3133 ssh->protocol = ssh2_protocol;
3134 ssh2_protocol_setup(ssh);
3135 ssh->s_rdpkt = ssh2_rdpkt;
3138 * Initialise SSH-1 protocol.
3140 ssh->protocol = ssh1_protocol;
3141 ssh1_protocol_setup(ssh);
3142 ssh->s_rdpkt = ssh1_rdpkt;
3144 if (ssh->version == 2)
3145 do_ssh2_transport(ssh, NULL, -1, NULL);
3147 update_specials_menu(ssh->frontend);
3148 ssh->state = SSH_STATE_BEFORE_SIZE;
3149 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3156 static int do_ssh_connection_init(Ssh ssh, unsigned char c)
3159 * Ordinary SSH begins with the banner "SSH-x.y-...". This is just
3160 * the ssh-connection part, extracted and given a trivial binary
3161 * packet protocol, so we replace 'SSH-' at the start with a new
3162 * name. In proper SSH style (though of course this part of the
3163 * proper SSH protocol _isn't_ subject to this kind of
3164 * DNS-domain-based extension), we define the new name in our
3167 static const char protoname[] =
3168 "SSHCONNECTION@putty.projects.tartarus.org-";
3170 struct do_ssh_connection_init_state {
3178 crState(do_ssh_connection_init_state);
3182 /* Search for a line beginning with the protocol name prefix in
3185 for (s->i = 0; protoname[s->i]; s->i++) {
3186 if ((char)c != protoname[s->i]) goto no;
3196 s->vstrsize = sizeof(protoname) + 16;
3197 s->vstring = snewn(s->vstrsize, char);
3198 strcpy(s->vstring, protoname);
3199 s->vslen = strlen(protoname);
3202 if (s->vslen >= s->vstrsize - 1) {
3204 s->vstring = sresize(s->vstring, s->vstrsize, char);
3206 s->vstring[s->vslen++] = c;
3209 s->version[s->i] = '\0';
3211 } else if (s->i < sizeof(s->version) - 1)
3212 s->version[s->i++] = c;
3213 } else if (c == '\012')
3215 crReturn(1); /* get another char */
3218 ssh->agentfwd_enabled = FALSE;
3219 ssh->rdpkt2_bare_state.incoming_sequence = 0;
3221 s->vstring[s->vslen] = 0;
3222 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
3223 logeventf(ssh, "Server version: %s", s->vstring);
3224 ssh_detect_bugs(ssh, s->vstring);
3227 * Decide which SSH protocol version to support. This is easy in
3228 * bare ssh-connection mode: only 2.0 is legal.
3230 if (ssh_versioncmp(s->version, "2.0") < 0) {
3231 bombout(("Server announces compatibility with SSH-1 in bare ssh-connection protocol"));
3234 if (conf_get_int(ssh->conf, CONF_sshprot) == 0) {
3235 bombout(("Bare ssh-connection protocol cannot be run in SSH-1-only mode"));
3241 logeventf(ssh, "Using bare ssh-connection protocol");
3243 /* Send the version string, if we haven't already */
3244 ssh_send_verstring(ssh, protoname, s->version);
3247 * Initialise bare connection protocol.
3249 ssh->protocol = ssh2_bare_connection_protocol;
3250 ssh2_bare_connection_protocol_setup(ssh);
3251 ssh->s_rdpkt = ssh2_bare_connection_rdpkt;
3253 update_specials_menu(ssh->frontend);
3254 ssh->state = SSH_STATE_BEFORE_SIZE;
3255 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3258 * Get authconn (really just conn) under way.
3260 do_ssh2_authconn(ssh, NULL, 0, NULL);
3267 static void ssh_process_incoming_data(Ssh ssh,
3268 const unsigned char **data, int *datalen)
3270 struct Packet *pktin;
3272 pktin = ssh->s_rdpkt(ssh, data, datalen);
3274 ssh->protocol(ssh, NULL, 0, pktin);
3275 ssh_free_packet(pktin);
3279 static void ssh_queue_incoming_data(Ssh ssh,
3280 const unsigned char **data, int *datalen)
3282 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
3287 static void ssh_process_queued_incoming_data(Ssh ssh)
3290 const unsigned char *data;
3293 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
3294 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
3298 while (!ssh->frozen && len > 0)
3299 ssh_process_incoming_data(ssh, &data, &len);
3302 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
3306 static void ssh_set_frozen(Ssh ssh, int frozen)
3309 sk_set_frozen(ssh->s, frozen);
3310 ssh->frozen = frozen;
3313 static void ssh_gotdata(Ssh ssh, const unsigned char *data, int datalen)
3315 /* Log raw data, if we're in that mode. */
3317 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
3318 0, NULL, NULL, 0, NULL);
3320 crBegin(ssh->ssh_gotdata_crstate);
3323 * To begin with, feed the characters one by one to the
3324 * protocol initialisation / selection function do_ssh_init().
3325 * When that returns 0, we're done with the initial greeting
3326 * exchange and can move on to packet discipline.
3329 int ret; /* need not be kept across crReturn */
3331 crReturnV; /* more data please */
3332 ret = ssh->do_ssh_init(ssh, *data);
3340 * We emerge from that loop when the initial negotiation is
3341 * over and we have selected an s_rdpkt function. Now pass
3342 * everything to s_rdpkt, and then pass the resulting packets
3343 * to the proper protocol handler.
3347 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
3349 ssh_queue_incoming_data(ssh, &data, &datalen);
3350 /* This uses up all data and cannot cause anything interesting
3351 * to happen; indeed, for anything to happen at all, we must
3352 * return, so break out. */
3354 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
3355 /* This uses up some or all data, and may freeze the
3357 ssh_process_queued_incoming_data(ssh);
3359 /* This uses up some or all data, and may freeze the
3361 ssh_process_incoming_data(ssh, &data, &datalen);
3363 /* FIXME this is probably EBW. */
3364 if (ssh->state == SSH_STATE_CLOSED)
3367 /* We're out of data. Go and get some more. */
3373 static int ssh_do_close(Ssh ssh, int notify_exit)
3376 struct ssh_channel *c;
3378 ssh->state = SSH_STATE_CLOSED;
3379 expire_timer_context(ssh);
3384 notify_remote_exit(ssh->frontend);
3389 * Now we must shut down any port- and X-forwarded channels going
3390 * through this connection.
3392 if (ssh->channels) {
3393 while (NULL != (c = index234(ssh->channels, 0))) {
3396 x11_close(c->u.x11.xconn);
3399 case CHAN_SOCKDATA_DORMANT:
3400 pfd_close(c->u.pfd.pf);
3403 del234(ssh->channels, c); /* moving next one to index 0 */
3404 if (ssh->version == 2)
3405 bufchain_clear(&c->v.v2.outbuffer);
3410 * Go through port-forwardings, and close any associated
3411 * listening sockets.
3413 if (ssh->portfwds) {
3414 struct ssh_portfwd *pf;
3415 while (NULL != (pf = index234(ssh->portfwds, 0))) {
3416 /* Dispose of any listening socket. */
3418 pfl_terminate(pf->local);
3419 del234(ssh->portfwds, pf); /* moving next one to index 0 */
3422 freetree234(ssh->portfwds);
3423 ssh->portfwds = NULL;
3427 * Also stop attempting to connection-share.
3429 if (ssh->connshare) {
3430 sharestate_free(ssh->connshare);
3431 ssh->connshare = NULL;
3437 static void ssh_socket_log(Plug plug, int type, SockAddr addr, int port,
3438 const char *error_msg, int error_code)
3440 Ssh ssh = (Ssh) plug;
3441 char addrbuf[256], *msg;
3443 if (ssh->attempting_connshare) {
3445 * While we're attempting connection sharing, don't loudly log
3446 * everything that happens. Real TCP connections need to be
3447 * logged when we _start_ trying to connect, because it might
3448 * be ages before they respond if something goes wrong; but
3449 * connection sharing is local and quick to respond, and it's
3450 * sufficient to simply wait and see whether it worked
3454 sk_getaddr(addr, addrbuf, lenof(addrbuf));
3457 if (sk_addr_needs_port(addr)) {
3458 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
3460 msg = dupprintf("Connecting to %s", addrbuf);
3463 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
3471 void ssh_connshare_log(Ssh ssh, int event, const char *logtext,
3472 const char *ds_err, const char *us_err)
3474 if (event == SHARE_NONE) {
3475 /* In this case, 'logtext' is an error message indicating a
3476 * reason why connection sharing couldn't be set up _at all_.
3477 * Failing that, ds_err and us_err indicate why we couldn't be
3478 * a downstream and an upstream respectively. */
3480 logeventf(ssh, "Could not set up connection sharing: %s", logtext);
3483 logeventf(ssh, "Could not set up connection sharing"
3484 " as downstream: %s", ds_err);
3486 logeventf(ssh, "Could not set up connection sharing"
3487 " as upstream: %s", us_err);
3489 } else if (event == SHARE_DOWNSTREAM) {
3490 /* In this case, 'logtext' is a local endpoint address */
3491 logeventf(ssh, "Using existing shared connection at %s", logtext);
3492 /* Also we should mention this in the console window to avoid
3493 * confusing users as to why this window doesn't behave the
3495 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3496 c_write_str(ssh,"Reusing a shared connection to this server.\r\n");
3498 } else if (event == SHARE_UPSTREAM) {
3499 /* In this case, 'logtext' is a local endpoint address too */
3500 logeventf(ssh, "Sharing this connection at %s", logtext);
3504 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
3507 Ssh ssh = (Ssh) plug;
3508 int need_notify = ssh_do_close(ssh, FALSE);
3511 if (!ssh->close_expected)
3512 error_msg = "Server unexpectedly closed network connection";
3514 error_msg = "Server closed network connection";
3517 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
3521 notify_remote_exit(ssh->frontend);
3524 logevent(error_msg);
3525 if (!ssh->close_expected || !ssh->clean_exit)
3526 connection_fatal(ssh->frontend, "%s", error_msg);
3530 static int ssh_receive(Plug plug, int urgent, char *data, int len)
3532 Ssh ssh = (Ssh) plug;
3533 ssh_gotdata(ssh, (unsigned char *)data, len);
3534 if (ssh->state == SSH_STATE_CLOSED) {
3535 ssh_do_close(ssh, TRUE);
3541 static void ssh_sent(Plug plug, int bufsize)
3543 Ssh ssh = (Ssh) plug;
3545 * If the send backlog on the SSH socket itself clears, we
3546 * should unthrottle the whole world if it was throttled.
3548 if (bufsize < SSH_MAX_BACKLOG)
3549 ssh_throttle_all(ssh, 0, bufsize);
3552 static void ssh_hostport_setup(const char *host, int port, Conf *conf,
3553 char **savedhost, int *savedport,
3556 char *loghost = conf_get_str(conf, CONF_loghost);
3558 *loghost_ret = loghost;
3564 tmphost = dupstr(loghost);
3565 *savedport = 22; /* default ssh port */
3568 * A colon suffix on the hostname string also lets us affect
3569 * savedport. (Unless there are multiple colons, in which case
3570 * we assume this is an unbracketed IPv6 literal.)
3572 colon = host_strrchr(tmphost, ':');
3573 if (colon && colon == host_strchr(tmphost, ':')) {
3576 *savedport = atoi(colon);
3579 *savedhost = host_strduptrim(tmphost);
3582 *savedhost = host_strduptrim(host);
3584 port = 22; /* default ssh port */
3589 static int ssh_test_for_upstream(const char *host, int port, Conf *conf)
3595 ssh_hostport_setup(host, port, conf, &savedhost, &savedport, NULL);
3596 ret = ssh_share_test_for_upstream(savedhost, savedport, conf);
3603 * Connect to specified host and port.
3604 * Returns an error message, or NULL on success.
3605 * Also places the canonical host name into `realhost'. It must be
3606 * freed by the caller.
3608 static const char *connect_to_host(Ssh ssh, const char *host, int port,
3609 char **realhost, int nodelay, int keepalive)
3611 static const struct plug_function_table fn_table = {
3622 int addressfamily, sshprot;
3624 ssh_hostport_setup(host, port, ssh->conf,
3625 &ssh->savedhost, &ssh->savedport, &loghost);
3627 ssh->fn = &fn_table; /* make 'ssh' usable as a Plug */
3630 * Try connection-sharing, in case that means we don't open a
3631 * socket after all. ssh_connection_sharing_init will connect to a
3632 * previously established upstream if it can, and failing that,
3633 * establish a listening socket for _us_ to be the upstream. In
3634 * the latter case it will return NULL just as if it had done
3635 * nothing, because here we only need to care if we're a
3636 * downstream and need to do our connection setup differently.
3638 ssh->connshare = NULL;
3639 ssh->attempting_connshare = TRUE; /* affects socket logging behaviour */
3640 ssh->s = ssh_connection_sharing_init(ssh->savedhost, ssh->savedport,
3641 ssh->conf, ssh, &ssh->connshare);
3642 ssh->attempting_connshare = FALSE;
3643 if (ssh->s != NULL) {
3645 * We are a downstream.
3647 ssh->bare_connection = TRUE;
3648 ssh->do_ssh_init = do_ssh_connection_init;
3649 ssh->fullhostname = NULL;
3650 *realhost = dupstr(host); /* best we can do */
3653 * We're not a downstream, so open a normal socket.
3655 ssh->do_ssh_init = do_ssh_init;
3660 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
3661 logeventf(ssh, "Looking up host \"%s\"%s", host,
3662 (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
3663 (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
3664 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily);
3665 if ((err = sk_addr_error(addr)) != NULL) {
3669 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3671 ssh->s = new_connection(addr, *realhost, port,
3672 0, 1, nodelay, keepalive,
3673 (Plug) ssh, ssh->conf);
3674 if ((err = sk_socket_error(ssh->s)) != NULL) {
3676 notify_remote_exit(ssh->frontend);
3682 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3683 * send the version string too.
3685 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3688 if (sshprot == 3 && !ssh->bare_connection) {
3690 ssh_send_verstring(ssh, "SSH-", NULL);
3694 * loghost, if configured, overrides realhost.
3698 *realhost = dupstr(loghost);
3705 * Throttle or unthrottle the SSH connection.
3707 static void ssh_throttle_conn(Ssh ssh, int adjust)
3709 int old_count = ssh->conn_throttle_count;
3710 ssh->conn_throttle_count += adjust;
3711 assert(ssh->conn_throttle_count >= 0);
3712 if (ssh->conn_throttle_count && !old_count) {
3713 ssh_set_frozen(ssh, 1);
3714 } else if (!ssh->conn_throttle_count && old_count) {
3715 ssh_set_frozen(ssh, 0);
3720 * Throttle or unthrottle _all_ local data streams (for when sends
3721 * on the SSH connection itself back up).
3723 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3726 struct ssh_channel *c;
3728 if (enable == ssh->throttled_all)
3730 ssh->throttled_all = enable;
3731 ssh->overall_bufsize = bufsize;
3734 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3736 case CHAN_MAINSESSION:
3738 * This is treated separately, outside the switch.
3742 x11_override_throttle(c->u.x11.xconn, enable);
3745 /* Agent channels require no buffer management. */
3748 pfd_override_throttle(c->u.pfd.pf, enable);
3754 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3756 Ssh ssh = (Ssh) sshv;
3758 ssh->agent_response = reply;
3759 ssh->agent_response_len = replylen;
3761 if (ssh->version == 1)
3762 do_ssh1_login(ssh, NULL, -1, NULL);
3764 do_ssh2_authconn(ssh, NULL, -1, NULL);
3767 static void ssh_dialog_callback(void *sshv, int ret)
3769 Ssh ssh = (Ssh) sshv;
3771 ssh->user_response = ret;
3773 if (ssh->version == 1)
3774 do_ssh1_login(ssh, NULL, -1, NULL);
3776 do_ssh2_transport(ssh, NULL, -1, NULL);
3779 * This may have unfrozen the SSH connection, so do a
3782 ssh_process_queued_incoming_data(ssh);
3785 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3787 struct ssh_channel *c = (struct ssh_channel *)cv;
3789 const void *sentreply = reply;
3791 c->u.a.outstanding_requests--;
3793 /* Fake SSH_AGENT_FAILURE. */
3794 sentreply = "\0\0\0\1\5";
3797 if (ssh->version == 2) {
3798 ssh2_add_channel_data(c, sentreply, replylen);
3801 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3802 PKT_INT, c->remoteid,
3804 PKT_DATA, sentreply, replylen,
3810 * If we've already seen an incoming EOF but haven't sent an
3811 * outgoing one, this may be the moment to send it.
3813 if (c->u.a.outstanding_requests == 0 && (c->closes & CLOSES_RCVD_EOF))
3814 sshfwd_write_eof(c);
3818 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3819 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3820 * => log `wire_reason'.
3822 static void ssh_disconnect(Ssh ssh, const char *client_reason,
3823 const char *wire_reason,
3824 int code, int clean_exit)
3828 client_reason = wire_reason;
3830 error = dupprintf("Disconnected: %s", client_reason);
3832 error = dupstr("Disconnected");
3834 if (ssh->version == 1) {
3835 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3837 } else if (ssh->version == 2) {
3838 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3839 ssh2_pkt_adduint32(pktout, code);
3840 ssh2_pkt_addstring(pktout, wire_reason);
3841 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3842 ssh2_pkt_send_noqueue(ssh, pktout);
3845 ssh->close_expected = TRUE;
3846 ssh->clean_exit = clean_exit;
3847 ssh_closing((Plug)ssh, error, 0, 0);
3851 int verify_ssh_manual_host_key(Ssh ssh, const char *fingerprint,
3852 const struct ssh_signkey *ssh2keytype,
3855 if (!conf_get_str_nthstrkey(ssh->conf, CONF_ssh_manual_hostkeys, 0)) {
3856 return -1; /* no manual keys configured */
3861 * The fingerprint string we've been given will have things
3862 * like 'ssh-rsa 2048' at the front of it. Strip those off and
3863 * narrow down to just the colon-separated hex block at the
3864 * end of the string.
3866 const char *p = strrchr(fingerprint, ' ');
3867 fingerprint = p ? p+1 : fingerprint;
3868 /* Quick sanity checks, including making sure it's in lowercase */
3869 assert(strlen(fingerprint) == 16*3 - 1);
3870 assert(fingerprint[2] == ':');
3871 assert(fingerprint[strspn(fingerprint, "0123456789abcdef:")] == 0);
3873 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3875 return 1; /* success */
3880 * Construct the base64-encoded public key blob and see if
3883 unsigned char *binblob;
3885 int binlen, atoms, i;
3886 binblob = ssh2keytype->public_blob(ssh2keydata, &binlen);
3887 atoms = (binlen + 2) / 3;
3888 base64blob = snewn(atoms * 4 + 1, char);
3889 for (i = 0; i < atoms; i++)
3890 base64_encode_atom(binblob + 3*i, binlen - 3*i, base64blob + 4*i);
3891 base64blob[atoms * 4] = '\0';
3893 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3896 return 1; /* success */
3905 * Handle the key exchange and user authentication phases.
3907 static int do_ssh1_login(Ssh ssh, const unsigned char *in, int inlen,
3908 struct Packet *pktin)
3911 unsigned char cookie[8], *ptr;
3912 struct MD5Context md5c;
3913 struct do_ssh1_login_state {
3916 unsigned char *rsabuf;
3917 const unsigned char *keystr1, *keystr2;
3918 unsigned long supported_ciphers_mask, supported_auths_mask;
3919 int tried_publickey, tried_agent;
3920 int tis_auth_refused, ccard_auth_refused;
3921 unsigned char session_id[16];
3923 void *publickey_blob;
3924 int publickey_bloblen;
3925 char *publickey_comment;
3926 int privatekey_available, privatekey_encrypted;
3927 prompts_t *cur_prompt;
3930 unsigned char request[5], *response, *p;
3940 struct RSAKey servkey, hostkey;
3942 crState(do_ssh1_login_state);
3949 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
3950 bombout(("Public key packet not received"));
3954 logevent("Received public keys");
3956 ptr = ssh_pkt_getdata(pktin, 8);
3958 bombout(("SSH-1 public key packet stopped before random cookie"));
3961 memcpy(cookie, ptr, 8);
3963 if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) ||
3964 !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) {
3965 bombout(("Failed to read SSH-1 public keys from public key packet"));
3970 * Log the host key fingerprint.
3974 logevent("Host key fingerprint is:");
3975 strcpy(logmsg, " ");
3976 s->hostkey.comment = NULL;
3977 rsa_fingerprint(logmsg + strlen(logmsg),
3978 sizeof(logmsg) - strlen(logmsg), &s->hostkey);
3982 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3983 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3984 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
3985 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
3986 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
3988 ssh->v1_local_protoflags =
3989 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3990 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
3993 MD5Update(&md5c, s->keystr2, s->hostkey.bytes);
3994 MD5Update(&md5c, s->keystr1, s->servkey.bytes);
3995 MD5Update(&md5c, cookie, 8);
3996 MD5Final(s->session_id, &md5c);
3998 for (i = 0; i < 32; i++)
3999 ssh->session_key[i] = random_byte();
4002 * Verify that the `bits' and `bytes' parameters match.
4004 if (s->hostkey.bits > s->hostkey.bytes * 8 ||
4005 s->servkey.bits > s->servkey.bytes * 8) {
4006 bombout(("SSH-1 public keys were badly formatted"));
4010 s->len = (s->hostkey.bytes > s->servkey.bytes ?
4011 s->hostkey.bytes : s->servkey.bytes);
4013 s->rsabuf = snewn(s->len, unsigned char);
4016 * Verify the host key.
4020 * First format the key into a string.
4022 int len = rsastr_len(&s->hostkey);
4023 char fingerprint[100];
4024 char *keystr = snewn(len, char);
4025 rsastr_fmt(keystr, &s->hostkey);
4026 rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey);
4028 /* First check against manually configured host keys. */
4029 s->dlgret = verify_ssh_manual_host_key(ssh, fingerprint, NULL, NULL);
4030 if (s->dlgret == 0) { /* did not match */
4031 bombout(("Host key did not appear in manually configured list"));
4034 } else if (s->dlgret < 0) { /* none configured; use standard handling */
4035 ssh_set_frozen(ssh, 1);
4036 s->dlgret = verify_ssh_host_key(ssh->frontend,
4037 ssh->savedhost, ssh->savedport,
4038 "rsa", keystr, fingerprint,
4039 ssh_dialog_callback, ssh);
4041 if (s->dlgret < 0) {
4045 bombout(("Unexpected data from server while waiting"
4046 " for user host key response"));
4049 } while (pktin || inlen > 0);
4050 s->dlgret = ssh->user_response;
4052 ssh_set_frozen(ssh, 0);
4054 if (s->dlgret == 0) {
4055 ssh_disconnect(ssh, "User aborted at host key verification",
4064 for (i = 0; i < 32; i++) {
4065 s->rsabuf[i] = ssh->session_key[i];
4067 s->rsabuf[i] ^= s->session_id[i];
4070 if (s->hostkey.bytes > s->servkey.bytes) {
4071 ret = rsaencrypt(s->rsabuf, 32, &s->servkey);
4073 ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey);
4075 ret = rsaencrypt(s->rsabuf, 32, &s->hostkey);
4077 ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey);
4080 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
4084 logevent("Encrypted session key");
4087 int cipher_chosen = 0, warn = 0;
4088 const char *cipher_string = NULL;
4090 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
4091 int next_cipher = conf_get_int_int(ssh->conf,
4092 CONF_ssh_cipherlist, i);
4093 if (next_cipher == CIPHER_WARN) {
4094 /* If/when we choose a cipher, warn about it */
4096 } else if (next_cipher == CIPHER_AES) {
4097 /* XXX Probably don't need to mention this. */
4098 logevent("AES not supported in SSH-1, skipping");
4100 switch (next_cipher) {
4101 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
4102 cipher_string = "3DES"; break;
4103 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
4104 cipher_string = "Blowfish"; break;
4105 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
4106 cipher_string = "single-DES"; break;
4108 if (s->supported_ciphers_mask & (1 << s->cipher_type))
4112 if (!cipher_chosen) {
4113 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
4114 bombout(("Server violates SSH-1 protocol by not "
4115 "supporting 3DES encryption"));
4117 /* shouldn't happen */
4118 bombout(("No supported ciphers found"));
4122 /* Warn about chosen cipher if necessary. */
4124 ssh_set_frozen(ssh, 1);
4125 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
4126 ssh_dialog_callback, ssh);
4127 if (s->dlgret < 0) {
4131 bombout(("Unexpected data from server while waiting"
4132 " for user response"));
4135 } while (pktin || inlen > 0);
4136 s->dlgret = ssh->user_response;
4138 ssh_set_frozen(ssh, 0);
4139 if (s->dlgret == 0) {
4140 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
4147 switch (s->cipher_type) {
4148 case SSH_CIPHER_3DES:
4149 logevent("Using 3DES encryption");
4151 case SSH_CIPHER_DES:
4152 logevent("Using single-DES encryption");
4154 case SSH_CIPHER_BLOWFISH:
4155 logevent("Using Blowfish encryption");
4159 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
4160 PKT_CHAR, s->cipher_type,
4161 PKT_DATA, cookie, 8,
4162 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
4163 PKT_DATA, s->rsabuf, s->len,
4164 PKT_INT, ssh->v1_local_protoflags, PKT_END);
4166 logevent("Trying to enable encryption...");
4170 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
4171 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
4173 ssh->v1_cipher_ctx = ssh->cipher->make_context();
4174 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
4175 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
4177 ssh->crcda_ctx = crcda_make_context();
4178 logevent("Installing CRC compensation attack detector");
4180 if (s->servkey.modulus) {
4181 sfree(s->servkey.modulus);
4182 s->servkey.modulus = NULL;
4184 if (s->servkey.exponent) {
4185 sfree(s->servkey.exponent);
4186 s->servkey.exponent = NULL;
4188 if (s->hostkey.modulus) {
4189 sfree(s->hostkey.modulus);
4190 s->hostkey.modulus = NULL;
4192 if (s->hostkey.exponent) {
4193 sfree(s->hostkey.exponent);
4194 s->hostkey.exponent = NULL;
4198 if (pktin->type != SSH1_SMSG_SUCCESS) {
4199 bombout(("Encryption not successfully enabled"));
4203 logevent("Successfully started encryption");
4205 fflush(stdout); /* FIXME eh? */
4207 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
4208 int ret; /* need not be kept over crReturn */
4209 s->cur_prompt = new_prompts(ssh->frontend);
4210 s->cur_prompt->to_server = TRUE;
4211 s->cur_prompt->name = dupstr("SSH login name");
4212 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
4213 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4216 crWaitUntil(!pktin);
4217 ret = get_userpass_input(s->cur_prompt, in, inlen);
4222 * Failed to get a username. Terminate.
4224 free_prompts(s->cur_prompt);
4225 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
4228 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
4229 free_prompts(s->cur_prompt);
4232 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
4234 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
4236 if (flags & FLAG_INTERACTIVE &&
4237 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
4238 c_write_str(ssh, userlog);
4239 c_write_str(ssh, "\r\n");
4247 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
4248 /* We must not attempt PK auth. Pretend we've already tried it. */
4249 s->tried_publickey = s->tried_agent = 1;
4251 s->tried_publickey = s->tried_agent = 0;
4253 s->tis_auth_refused = s->ccard_auth_refused = 0;
4255 * Load the public half of any configured keyfile for later use.
4257 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4258 if (!filename_is_null(s->keyfile)) {
4260 logeventf(ssh, "Reading key file \"%.150s\"",
4261 filename_to_str(s->keyfile));
4262 keytype = key_type(s->keyfile);
4263 if (keytype == SSH_KEYTYPE_SSH1 ||
4264 keytype == SSH_KEYTYPE_SSH1_PUBLIC) {
4266 if (rsakey_pubblob(s->keyfile,
4267 &s->publickey_blob, &s->publickey_bloblen,
4268 &s->publickey_comment, &error)) {
4269 s->privatekey_available = (keytype == SSH_KEYTYPE_SSH1);
4270 if (!s->privatekey_available)
4271 logeventf(ssh, "Key file contains public key only");
4272 s->privatekey_encrypted = rsakey_encrypted(s->keyfile,
4276 logeventf(ssh, "Unable to load key (%s)", error);
4277 msgbuf = dupprintf("Unable to load key file "
4278 "\"%.150s\" (%s)\r\n",
4279 filename_to_str(s->keyfile),
4281 c_write_str(ssh, msgbuf);
4283 s->publickey_blob = NULL;
4287 logeventf(ssh, "Unable to use this key file (%s)",
4288 key_type_to_str(keytype));
4289 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4291 filename_to_str(s->keyfile),
4292 key_type_to_str(keytype));
4293 c_write_str(ssh, msgbuf);
4295 s->publickey_blob = NULL;
4298 s->publickey_blob = NULL;
4300 while (pktin->type == SSH1_SMSG_FAILURE) {
4301 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
4303 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
4305 * Attempt RSA authentication using Pageant.
4311 logevent("Pageant is running. Requesting keys.");
4313 /* Request the keys held by the agent. */
4314 PUT_32BIT(s->request, 1);
4315 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
4316 if (!agent_query(s->request, 5, &r, &s->responselen,
4317 ssh_agent_callback, ssh)) {
4321 bombout(("Unexpected data from server while waiting"
4322 " for agent response"));
4325 } while (pktin || inlen > 0);
4326 r = ssh->agent_response;
4327 s->responselen = ssh->agent_response_len;
4329 s->response = (unsigned char *) r;
4330 if (s->response && s->responselen >= 5 &&
4331 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
4332 s->p = s->response + 5;
4333 s->nkeys = toint(GET_32BIT(s->p));
4335 logeventf(ssh, "Pageant reported negative key count %d",
4340 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
4341 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4342 unsigned char *pkblob = s->p;
4346 do { /* do while (0) to make breaking easy */
4347 n = ssh1_read_bignum
4348 (s->p, toint(s->responselen-(s->p-s->response)),
4353 n = ssh1_read_bignum
4354 (s->p, toint(s->responselen-(s->p-s->response)),
4359 if (s->responselen - (s->p-s->response) < 4)
4361 s->commentlen = toint(GET_32BIT(s->p));
4363 if (s->commentlen < 0 ||
4364 toint(s->responselen - (s->p-s->response)) <
4367 s->commentp = (char *)s->p;
4368 s->p += s->commentlen;
4372 logevent("Pageant key list packet was truncated");
4376 if (s->publickey_blob) {
4377 if (!memcmp(pkblob, s->publickey_blob,
4378 s->publickey_bloblen)) {
4379 logeventf(ssh, "Pageant key #%d matches "
4380 "configured key file", s->keyi);
4381 s->tried_publickey = 1;
4383 /* Skip non-configured key */
4386 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
4387 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4388 PKT_BIGNUM, s->key.modulus, PKT_END);
4390 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4391 logevent("Key refused");
4394 logevent("Received RSA challenge");
4395 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4396 bombout(("Server's RSA challenge was badly formatted"));
4401 char *agentreq, *q, *ret;
4404 len = 1 + 4; /* message type, bit count */
4405 len += ssh1_bignum_length(s->key.exponent);
4406 len += ssh1_bignum_length(s->key.modulus);
4407 len += ssh1_bignum_length(s->challenge);
4408 len += 16; /* session id */
4409 len += 4; /* response format */
4410 agentreq = snewn(4 + len, char);
4411 PUT_32BIT(agentreq, len);
4413 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
4414 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
4416 q += ssh1_write_bignum(q, s->key.exponent);
4417 q += ssh1_write_bignum(q, s->key.modulus);
4418 q += ssh1_write_bignum(q, s->challenge);
4419 memcpy(q, s->session_id, 16);
4421 PUT_32BIT(q, 1); /* response format */
4422 if (!agent_query(agentreq, len + 4, &vret, &retlen,
4423 ssh_agent_callback, ssh)) {
4428 bombout(("Unexpected data from server"
4429 " while waiting for agent"
4433 } while (pktin || inlen > 0);
4434 vret = ssh->agent_response;
4435 retlen = ssh->agent_response_len;
4440 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
4441 logevent("Sending Pageant's response");
4442 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4443 PKT_DATA, ret + 5, 16,
4447 if (pktin->type == SSH1_SMSG_SUCCESS) {
4449 ("Pageant's response accepted");
4450 if (flags & FLAG_VERBOSE) {
4451 c_write_str(ssh, "Authenticated using"
4453 c_write(ssh, s->commentp,
4455 c_write_str(ssh, "\" from agent\r\n");
4460 ("Pageant's response not accepted");
4463 ("Pageant failed to answer challenge");
4467 logevent("No reply received from Pageant");
4470 freebn(s->key.exponent);
4471 freebn(s->key.modulus);
4472 freebn(s->challenge);
4477 if (s->publickey_blob && !s->tried_publickey)
4478 logevent("Configured key file not in Pageant");
4480 logevent("Failed to get reply from Pageant");
4485 if (s->publickey_blob && s->privatekey_available &&
4486 !s->tried_publickey) {
4488 * Try public key authentication with the specified
4491 int got_passphrase; /* need not be kept over crReturn */
4492 if (flags & FLAG_VERBOSE)
4493 c_write_str(ssh, "Trying public key authentication.\r\n");
4494 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4495 logeventf(ssh, "Trying public key \"%s\"",
4496 filename_to_str(s->keyfile));
4497 s->tried_publickey = 1;
4498 got_passphrase = FALSE;
4499 while (!got_passphrase) {
4501 * Get a passphrase, if necessary.
4503 char *passphrase = NULL; /* only written after crReturn */
4505 if (!s->privatekey_encrypted) {
4506 if (flags & FLAG_VERBOSE)
4507 c_write_str(ssh, "No passphrase required.\r\n");
4510 int ret; /* need not be kept over crReturn */
4511 s->cur_prompt = new_prompts(ssh->frontend);
4512 s->cur_prompt->to_server = FALSE;
4513 s->cur_prompt->name = dupstr("SSH key passphrase");
4514 add_prompt(s->cur_prompt,
4515 dupprintf("Passphrase for key \"%.100s\": ",
4516 s->publickey_comment), FALSE);
4517 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4520 crWaitUntil(!pktin);
4521 ret = get_userpass_input(s->cur_prompt, in, inlen);
4525 /* Failed to get a passphrase. Terminate. */
4526 free_prompts(s->cur_prompt);
4527 ssh_disconnect(ssh, NULL, "Unable to authenticate",
4531 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
4532 free_prompts(s->cur_prompt);
4535 * Try decrypting key with passphrase.
4537 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4538 ret = loadrsakey(s->keyfile, &s->key, passphrase,
4541 smemclr(passphrase, strlen(passphrase));
4545 /* Correct passphrase. */
4546 got_passphrase = TRUE;
4547 } else if (ret == 0) {
4548 c_write_str(ssh, "Couldn't load private key from ");
4549 c_write_str(ssh, filename_to_str(s->keyfile));
4550 c_write_str(ssh, " (");
4551 c_write_str(ssh, error);
4552 c_write_str(ssh, ").\r\n");
4553 got_passphrase = FALSE;
4554 break; /* go and try something else */
4555 } else if (ret == -1) {
4556 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
4557 got_passphrase = FALSE;
4560 assert(0 && "unexpected return from loadrsakey()");
4561 got_passphrase = FALSE; /* placate optimisers */
4565 if (got_passphrase) {
4568 * Send a public key attempt.
4570 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4571 PKT_BIGNUM, s->key.modulus, PKT_END);
4574 if (pktin->type == SSH1_SMSG_FAILURE) {
4575 c_write_str(ssh, "Server refused our public key.\r\n");
4576 continue; /* go and try something else */
4578 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4579 bombout(("Bizarre response to offer of public key"));
4585 unsigned char buffer[32];
4586 Bignum challenge, response;
4588 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4589 bombout(("Server's RSA challenge was badly formatted"));
4592 response = rsadecrypt(challenge, &s->key);
4593 freebn(s->key.private_exponent);/* burn the evidence */
4595 for (i = 0; i < 32; i++) {
4596 buffer[i] = bignum_byte(response, 31 - i);
4600 MD5Update(&md5c, buffer, 32);
4601 MD5Update(&md5c, s->session_id, 16);
4602 MD5Final(buffer, &md5c);
4604 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4605 PKT_DATA, buffer, 16, PKT_END);
4612 if (pktin->type == SSH1_SMSG_FAILURE) {
4613 if (flags & FLAG_VERBOSE)
4614 c_write_str(ssh, "Failed to authenticate with"
4615 " our public key.\r\n");
4616 continue; /* go and try something else */
4617 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4618 bombout(("Bizarre response to RSA authentication response"));
4622 break; /* we're through! */
4628 * Otherwise, try various forms of password-like authentication.
4630 s->cur_prompt = new_prompts(ssh->frontend);
4632 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4633 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
4634 !s->tis_auth_refused) {
4635 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
4636 logevent("Requested TIS authentication");
4637 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
4639 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
4640 logevent("TIS authentication declined");
4641 if (flags & FLAG_INTERACTIVE)
4642 c_write_str(ssh, "TIS authentication refused.\r\n");
4643 s->tis_auth_refused = 1;
4648 char *instr_suf, *prompt;
4650 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4652 bombout(("TIS challenge packet was badly formed"));
4655 logevent("Received TIS challenge");
4656 s->cur_prompt->to_server = TRUE;
4657 s->cur_prompt->name = dupstr("SSH TIS authentication");
4658 /* Prompt heuristic comes from OpenSSH */
4659 if (memchr(challenge, '\n', challengelen)) {
4660 instr_suf = dupstr("");
4661 prompt = dupprintf("%.*s", challengelen, challenge);
4663 instr_suf = dupprintf("%.*s", challengelen, challenge);
4664 prompt = dupstr("Response: ");
4666 s->cur_prompt->instruction =
4667 dupprintf("Using TIS authentication.%s%s",
4668 (*instr_suf) ? "\n" : "",
4670 s->cur_prompt->instr_reqd = TRUE;
4671 add_prompt(s->cur_prompt, prompt, FALSE);
4675 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4676 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
4677 !s->ccard_auth_refused) {
4678 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
4679 logevent("Requested CryptoCard authentication");
4680 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
4682 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
4683 logevent("CryptoCard authentication declined");
4684 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4685 s->ccard_auth_refused = 1;
4690 char *instr_suf, *prompt;
4692 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4694 bombout(("CryptoCard challenge packet was badly formed"));
4697 logevent("Received CryptoCard challenge");
4698 s->cur_prompt->to_server = TRUE;
4699 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4700 s->cur_prompt->name_reqd = FALSE;
4701 /* Prompt heuristic comes from OpenSSH */
4702 if (memchr(challenge, '\n', challengelen)) {
4703 instr_suf = dupstr("");
4704 prompt = dupprintf("%.*s", challengelen, challenge);
4706 instr_suf = dupprintf("%.*s", challengelen, challenge);
4707 prompt = dupstr("Response: ");
4709 s->cur_prompt->instruction =
4710 dupprintf("Using CryptoCard authentication.%s%s",
4711 (*instr_suf) ? "\n" : "",
4713 s->cur_prompt->instr_reqd = TRUE;
4714 add_prompt(s->cur_prompt, prompt, FALSE);
4718 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4719 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4720 bombout(("No supported authentication methods available"));
4723 s->cur_prompt->to_server = TRUE;
4724 s->cur_prompt->name = dupstr("SSH password");
4725 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4726 ssh->username, ssh->savedhost),
4731 * Show password prompt, having first obtained it via a TIS
4732 * or CryptoCard exchange if we're doing TIS or CryptoCard
4736 int ret; /* need not be kept over crReturn */
4737 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4740 crWaitUntil(!pktin);
4741 ret = get_userpass_input(s->cur_prompt, in, inlen);
4746 * Failed to get a password (for example
4747 * because one was supplied on the command line
4748 * which has already failed to work). Terminate.
4750 free_prompts(s->cur_prompt);
4751 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4756 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4758 * Defence against traffic analysis: we send a
4759 * whole bunch of packets containing strings of
4760 * different lengths. One of these strings is the
4761 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4762 * The others are all random data in
4763 * SSH1_MSG_IGNORE packets. This way a passive
4764 * listener can't tell which is the password, and
4765 * hence can't deduce the password length.
4767 * Anybody with a password length greater than 16
4768 * bytes is going to have enough entropy in their
4769 * password that a listener won't find it _that_
4770 * much help to know how long it is. So what we'll
4773 * - if password length < 16, we send 15 packets
4774 * containing string lengths 1 through 15
4776 * - otherwise, we let N be the nearest multiple
4777 * of 8 below the password length, and send 8
4778 * packets containing string lengths N through
4779 * N+7. This won't obscure the order of
4780 * magnitude of the password length, but it will
4781 * introduce a bit of extra uncertainty.
4783 * A few servers can't deal with SSH1_MSG_IGNORE, at
4784 * least in this context. For these servers, we need
4785 * an alternative defence. We make use of the fact
4786 * that the password is interpreted as a C string:
4787 * so we can append a NUL, then some random data.
4789 * A few servers can deal with neither SSH1_MSG_IGNORE
4790 * here _nor_ a padded password string.
4791 * For these servers we are left with no defences
4792 * against password length sniffing.
4794 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4795 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4797 * The server can deal with SSH1_MSG_IGNORE, so
4798 * we can use the primary defence.
4800 int bottom, top, pwlen, i;
4803 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4805 bottom = 0; /* zero length passwords are OK! :-) */
4808 bottom = pwlen & ~7;
4812 assert(pwlen >= bottom && pwlen <= top);
4814 randomstr = snewn(top + 1, char);
4816 for (i = bottom; i <= top; i++) {
4818 defer_packet(ssh, s->pwpkt_type,
4819 PKT_STR,s->cur_prompt->prompts[0]->result,
4822 for (j = 0; j < i; j++) {
4824 randomstr[j] = random_byte();
4825 } while (randomstr[j] == '\0');
4827 randomstr[i] = '\0';
4828 defer_packet(ssh, SSH1_MSG_IGNORE,
4829 PKT_STR, randomstr, PKT_END);
4832 logevent("Sending password with camouflage packets");
4833 ssh_pkt_defersend(ssh);
4836 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4838 * The server can't deal with SSH1_MSG_IGNORE
4839 * but can deal with padded passwords, so we
4840 * can use the secondary defence.
4846 len = strlen(s->cur_prompt->prompts[0]->result);
4847 if (len < sizeof(string)) {
4849 strcpy(string, s->cur_prompt->prompts[0]->result);
4850 len++; /* cover the zero byte */
4851 while (len < sizeof(string)) {
4852 string[len++] = (char) random_byte();
4855 ss = s->cur_prompt->prompts[0]->result;
4857 logevent("Sending length-padded password");
4858 send_packet(ssh, s->pwpkt_type,
4859 PKT_INT, len, PKT_DATA, ss, len,
4863 * The server is believed unable to cope with
4864 * any of our password camouflage methods.
4867 len = strlen(s->cur_prompt->prompts[0]->result);
4868 logevent("Sending unpadded password");
4869 send_packet(ssh, s->pwpkt_type,
4871 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4875 send_packet(ssh, s->pwpkt_type,
4876 PKT_STR, s->cur_prompt->prompts[0]->result,
4879 logevent("Sent password");
4880 free_prompts(s->cur_prompt);
4882 if (pktin->type == SSH1_SMSG_FAILURE) {
4883 if (flags & FLAG_VERBOSE)
4884 c_write_str(ssh, "Access denied\r\n");
4885 logevent("Authentication refused");
4886 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4887 bombout(("Strange packet received, type %d", pktin->type));
4893 if (s->publickey_blob) {
4894 sfree(s->publickey_blob);
4895 sfree(s->publickey_comment);
4898 logevent("Authentication successful");
4903 static void ssh_channel_try_eof(struct ssh_channel *c)
4906 assert(c->pending_eof); /* precondition for calling us */
4908 return; /* can't close: not even opened yet */
4909 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4910 return; /* can't send EOF: pending outgoing data */
4912 c->pending_eof = FALSE; /* we're about to send it */
4913 if (ssh->version == 1) {
4914 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4916 c->closes |= CLOSES_SENT_EOF;
4918 struct Packet *pktout;
4919 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4920 ssh2_pkt_adduint32(pktout, c->remoteid);
4921 ssh2_pkt_send(ssh, pktout);
4922 c->closes |= CLOSES_SENT_EOF;
4923 ssh2_channel_check_close(c);
4927 Conf *sshfwd_get_conf(struct ssh_channel *c)
4933 void sshfwd_write_eof(struct ssh_channel *c)
4937 if (ssh->state == SSH_STATE_CLOSED)
4940 if (c->closes & CLOSES_SENT_EOF)
4943 c->pending_eof = TRUE;
4944 ssh_channel_try_eof(c);
4947 void sshfwd_unclean_close(struct ssh_channel *c, const char *err)
4951 if (ssh->state == SSH_STATE_CLOSED)
4956 x11_close(c->u.x11.xconn);
4957 logeventf(ssh, "Forwarded X11 connection terminated due to local "
4961 case CHAN_SOCKDATA_DORMANT:
4962 pfd_close(c->u.pfd.pf);
4963 logeventf(ssh, "Forwarded port closed due to local error: %s", err);
4966 c->type = CHAN_ZOMBIE;
4967 c->pending_eof = FALSE; /* this will confuse a zombie channel */
4969 ssh2_channel_check_close(c);
4972 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
4976 if (ssh->state == SSH_STATE_CLOSED)
4979 if (ssh->version == 1) {
4980 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
4981 PKT_INT, c->remoteid,
4982 PKT_INT, len, PKT_DATA, buf, len,
4985 * In SSH-1 we can return 0 here - implying that forwarded
4986 * connections are never individually throttled - because
4987 * the only circumstance that can cause throttling will be
4988 * the whole SSH connection backing up, in which case
4989 * _everything_ will be throttled as a whole.
4993 ssh2_add_channel_data(c, buf, len);
4994 return ssh2_try_send(c);
4998 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
5003 if (ssh->state == SSH_STATE_CLOSED)
5006 if (ssh->version == 1) {
5007 buflimit = SSH1_BUFFER_LIMIT;
5009 buflimit = c->v.v2.locmaxwin;
5010 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
5012 if (c->throttling_conn && bufsize <= buflimit) {
5013 c->throttling_conn = 0;
5014 ssh_throttle_conn(ssh, -1);
5018 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
5020 struct queued_handler *qh = ssh->qhead;
5024 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
5027 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
5028 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
5031 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
5032 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
5036 ssh->qhead = qh->next;
5038 if (ssh->qhead->msg1 > 0) {
5039 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
5040 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
5042 if (ssh->qhead->msg2 > 0) {
5043 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
5044 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
5047 ssh->qhead = ssh->qtail = NULL;
5050 qh->handler(ssh, pktin, qh->ctx);
5055 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
5056 chandler_fn_t handler, void *ctx)
5058 struct queued_handler *qh;
5060 qh = snew(struct queued_handler);
5063 qh->handler = handler;
5067 if (ssh->qtail == NULL) {
5071 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
5072 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
5075 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
5076 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
5079 ssh->qtail->next = qh;
5084 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
5086 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
5088 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
5089 SSH2_MSG_REQUEST_SUCCESS)) {
5090 logeventf(ssh, "Remote port forwarding from %s enabled",
5093 logeventf(ssh, "Remote port forwarding from %s refused",
5096 rpf = del234(ssh->rportfwds, pf);
5098 pf->pfrec->remote = NULL;
5103 int ssh_alloc_sharing_rportfwd(Ssh ssh, const char *shost, int sport,
5106 struct ssh_rportfwd *pf = snew(struct ssh_rportfwd);
5109 pf->share_ctx = share_ctx;
5110 pf->shost = dupstr(shost);
5112 pf->sportdesc = NULL;
5113 if (!ssh->rportfwds) {
5114 assert(ssh->version == 2);
5115 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5117 if (add234(ssh->rportfwds, pf) != pf) {
5125 static void ssh_sharing_global_request_response(Ssh ssh, struct Packet *pktin,
5128 share_got_pkt_from_server(ctx, pktin->type,
5129 pktin->body, pktin->length);
5132 void ssh_sharing_queue_global_request(Ssh ssh, void *share_ctx)
5134 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, SSH2_MSG_REQUEST_FAILURE,
5135 ssh_sharing_global_request_response, share_ctx);
5138 static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
5140 struct ssh_portfwd *epf;
5144 if (!ssh->portfwds) {
5145 ssh->portfwds = newtree234(ssh_portcmp);
5148 * Go through the existing port forwardings and tag them
5149 * with status==DESTROY. Any that we want to keep will be
5150 * re-enabled (status==KEEP) as we go through the
5151 * configuration and find out which bits are the same as
5154 struct ssh_portfwd *epf;
5156 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5157 epf->status = DESTROY;
5160 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
5162 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
5163 char *kp, *kp2, *vp, *vp2;
5164 char address_family, type;
5165 int sport,dport,sserv,dserv;
5166 char *sports, *dports, *saddr, *host;
5170 address_family = 'A';
5172 if (*kp == 'A' || *kp == '4' || *kp == '6')
5173 address_family = *kp++;
5174 if (*kp == 'L' || *kp == 'R')
5177 if ((kp2 = host_strchr(kp, ':')) != NULL) {
5179 * There's a colon in the middle of the source port
5180 * string, which means that the part before it is
5181 * actually a source address.
5183 char *saddr_tmp = dupprintf("%.*s", (int)(kp2 - kp), kp);
5184 saddr = host_strduptrim(saddr_tmp);
5191 sport = atoi(sports);
5195 sport = net_service_lookup(sports);
5197 logeventf(ssh, "Service lookup failed for source"
5198 " port \"%s\"", sports);
5202 if (type == 'L' && !strcmp(val, "D")) {
5203 /* dynamic forwarding */
5210 /* ordinary forwarding */
5212 vp2 = vp + host_strcspn(vp, ":");
5213 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
5217 dport = atoi(dports);
5221 dport = net_service_lookup(dports);
5223 logeventf(ssh, "Service lookup failed for destination"
5224 " port \"%s\"", dports);
5229 if (sport && dport) {
5230 /* Set up a description of the source port. */
5231 struct ssh_portfwd *pfrec, *epfrec;
5233 pfrec = snew(struct ssh_portfwd);
5235 pfrec->saddr = saddr;
5236 pfrec->sserv = sserv ? dupstr(sports) : NULL;
5237 pfrec->sport = sport;
5238 pfrec->daddr = host;
5239 pfrec->dserv = dserv ? dupstr(dports) : NULL;
5240 pfrec->dport = dport;
5241 pfrec->local = NULL;
5242 pfrec->remote = NULL;
5243 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
5244 address_family == '6' ? ADDRTYPE_IPV6 :
5247 epfrec = add234(ssh->portfwds, pfrec);
5248 if (epfrec != pfrec) {
5249 if (epfrec->status == DESTROY) {
5251 * We already have a port forwarding up and running
5252 * with precisely these parameters. Hence, no need
5253 * to do anything; simply re-tag the existing one
5256 epfrec->status = KEEP;
5259 * Anything else indicates that there was a duplicate
5260 * in our input, which we'll silently ignore.
5262 free_portfwd(pfrec);
5264 pfrec->status = CREATE;
5273 * Now go through and destroy any port forwardings which were
5276 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5277 if (epf->status == DESTROY) {
5280 message = dupprintf("%s port forwarding from %s%s%d",
5281 epf->type == 'L' ? "local" :
5282 epf->type == 'R' ? "remote" : "dynamic",
5283 epf->saddr ? epf->saddr : "",
5284 epf->saddr ? ":" : "",
5287 if (epf->type != 'D') {
5288 char *msg2 = dupprintf("%s to %s:%d", message,
5289 epf->daddr, epf->dport);
5294 logeventf(ssh, "Cancelling %s", message);
5297 /* epf->remote or epf->local may be NULL if setting up a
5298 * forwarding failed. */
5300 struct ssh_rportfwd *rpf = epf->remote;
5301 struct Packet *pktout;
5304 * Cancel the port forwarding at the server
5307 if (ssh->version == 1) {
5309 * We cannot cancel listening ports on the
5310 * server side in SSH-1! There's no message
5311 * to support it. Instead, we simply remove
5312 * the rportfwd record from the local end
5313 * so that any connections the server tries
5314 * to make on it are rejected.
5317 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5318 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
5319 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
5321 ssh2_pkt_addstring(pktout, epf->saddr);
5322 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5323 /* XXX: rport_acceptall may not represent
5324 * what was used to open the original connection,
5325 * since it's reconfigurable. */
5326 ssh2_pkt_addstring(pktout, "");
5328 ssh2_pkt_addstring(pktout, "localhost");
5330 ssh2_pkt_adduint32(pktout, epf->sport);
5331 ssh2_pkt_send(ssh, pktout);
5334 del234(ssh->rportfwds, rpf);
5336 } else if (epf->local) {
5337 pfl_terminate(epf->local);
5340 delpos234(ssh->portfwds, i);
5342 i--; /* so we don't skip one in the list */
5346 * And finally, set up any new port forwardings (status==CREATE).
5348 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5349 if (epf->status == CREATE) {
5350 char *sportdesc, *dportdesc;
5351 sportdesc = dupprintf("%s%s%s%s%d%s",
5352 epf->saddr ? epf->saddr : "",
5353 epf->saddr ? ":" : "",
5354 epf->sserv ? epf->sserv : "",
5355 epf->sserv ? "(" : "",
5357 epf->sserv ? ")" : "");
5358 if (epf->type == 'D') {
5361 dportdesc = dupprintf("%s:%s%s%d%s",
5363 epf->dserv ? epf->dserv : "",
5364 epf->dserv ? "(" : "",
5366 epf->dserv ? ")" : "");
5369 if (epf->type == 'L') {
5370 char *err = pfl_listen(epf->daddr, epf->dport,
5371 epf->saddr, epf->sport,
5372 ssh, conf, &epf->local,
5373 epf->addressfamily);
5375 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
5376 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5377 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5378 sportdesc, dportdesc,
5379 err ? " failed: " : "", err ? err : "");
5382 } else if (epf->type == 'D') {
5383 char *err = pfl_listen(NULL, -1, epf->saddr, epf->sport,
5384 ssh, conf, &epf->local,
5385 epf->addressfamily);
5387 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
5388 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5389 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5391 err ? " failed: " : "", err ? err : "");
5396 struct ssh_rportfwd *pf;
5399 * Ensure the remote port forwardings tree exists.
5401 if (!ssh->rportfwds) {
5402 if (ssh->version == 1)
5403 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
5405 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5408 pf = snew(struct ssh_rportfwd);
5409 pf->share_ctx = NULL;
5410 pf->dhost = dupstr(epf->daddr);
5411 pf->dport = epf->dport;
5413 pf->shost = dupstr(epf->saddr);
5414 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5415 pf->shost = dupstr("");
5417 pf->shost = dupstr("localhost");
5419 pf->sport = epf->sport;
5420 if (add234(ssh->rportfwds, pf) != pf) {
5421 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
5422 epf->daddr, epf->dport);
5425 logeventf(ssh, "Requesting remote port %s"
5426 " forward to %s", sportdesc, dportdesc);
5428 pf->sportdesc = sportdesc;
5433 if (ssh->version == 1) {
5434 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
5435 PKT_INT, epf->sport,
5436 PKT_STR, epf->daddr,
5437 PKT_INT, epf->dport,
5439 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
5441 ssh_rportfwd_succfail, pf);
5443 struct Packet *pktout;
5444 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5445 ssh2_pkt_addstring(pktout, "tcpip-forward");
5446 ssh2_pkt_addbool(pktout, 1);/* want reply */
5447 ssh2_pkt_addstring(pktout, pf->shost);
5448 ssh2_pkt_adduint32(pktout, pf->sport);
5449 ssh2_pkt_send(ssh, pktout);
5451 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
5452 SSH2_MSG_REQUEST_FAILURE,
5453 ssh_rportfwd_succfail, pf);
5462 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
5465 int stringlen, bufsize;
5467 ssh_pkt_getstring(pktin, &string, &stringlen);
5468 if (string == NULL) {
5469 bombout(("Incoming terminal data packet was badly formed"));
5473 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
5475 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
5476 ssh->v1_stdout_throttling = 1;
5477 ssh_throttle_conn(ssh, +1);
5481 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
5483 /* Remote side is trying to open a channel to talk to our
5484 * X-Server. Give them back a local channel number. */
5485 struct ssh_channel *c;
5486 int remoteid = ssh_pkt_getuint32(pktin);
5488 logevent("Received X11 connect request");
5489 /* Refuse if X11 forwarding is disabled. */
5490 if (!ssh->X11_fwd_enabled) {
5491 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5492 PKT_INT, remoteid, PKT_END);
5493 logevent("Rejected X11 connect request");
5495 c = snew(struct ssh_channel);
5498 c->u.x11.xconn = x11_init(ssh->x11authtree, c, NULL, -1);
5499 c->remoteid = remoteid;
5500 c->halfopen = FALSE;
5501 c->localid = alloc_channel_id(ssh);
5503 c->pending_eof = FALSE;
5504 c->throttling_conn = 0;
5505 c->type = CHAN_X11; /* identify channel type */
5506 add234(ssh->channels, c);
5507 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5508 PKT_INT, c->remoteid, PKT_INT,
5509 c->localid, PKT_END);
5510 logevent("Opened X11 forward channel");
5514 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
5516 /* Remote side is trying to open a channel to talk to our
5517 * agent. Give them back a local channel number. */
5518 struct ssh_channel *c;
5519 int remoteid = ssh_pkt_getuint32(pktin);
5521 /* Refuse if agent forwarding is disabled. */
5522 if (!ssh->agentfwd_enabled) {
5523 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5524 PKT_INT, remoteid, PKT_END);
5526 c = snew(struct ssh_channel);
5528 c->remoteid = remoteid;
5529 c->halfopen = FALSE;
5530 c->localid = alloc_channel_id(ssh);
5532 c->pending_eof = FALSE;
5533 c->throttling_conn = 0;
5534 c->type = CHAN_AGENT; /* identify channel type */
5535 c->u.a.lensofar = 0;
5536 c->u.a.message = NULL;
5537 c->u.a.outstanding_requests = 0;
5538 add234(ssh->channels, c);
5539 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5540 PKT_INT, c->remoteid, PKT_INT, c->localid,
5545 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
5547 /* Remote side is trying to open a channel to talk to a
5548 * forwarded port. Give them back a local channel number. */
5549 struct ssh_rportfwd pf, *pfp;
5555 remoteid = ssh_pkt_getuint32(pktin);
5556 ssh_pkt_getstring(pktin, &host, &hostsize);
5557 port = ssh_pkt_getuint32(pktin);
5559 pf.dhost = dupprintf("%.*s", hostsize, host);
5561 pfp = find234(ssh->rportfwds, &pf, NULL);
5564 logeventf(ssh, "Rejected remote port open request for %s:%d",
5566 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5567 PKT_INT, remoteid, PKT_END);
5569 struct ssh_channel *c = snew(struct ssh_channel);
5572 logeventf(ssh, "Received remote port open request for %s:%d",
5574 err = pfd_connect(&c->u.pfd.pf, pf.dhost, port,
5575 c, ssh->conf, pfp->pfrec->addressfamily);
5577 logeventf(ssh, "Port open failed: %s", err);
5580 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5581 PKT_INT, remoteid, PKT_END);
5583 c->remoteid = remoteid;
5584 c->halfopen = FALSE;
5585 c->localid = alloc_channel_id(ssh);
5587 c->pending_eof = FALSE;
5588 c->throttling_conn = 0;
5589 c->type = CHAN_SOCKDATA; /* identify channel type */
5590 add234(ssh->channels, c);
5591 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5592 PKT_INT, c->remoteid, PKT_INT,
5593 c->localid, PKT_END);
5594 logevent("Forwarded port opened successfully");
5601 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5603 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5604 unsigned int localid = ssh_pkt_getuint32(pktin);
5605 struct ssh_channel *c;
5607 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5608 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5609 c->remoteid = localid;
5610 c->halfopen = FALSE;
5611 c->type = CHAN_SOCKDATA;
5612 c->throttling_conn = 0;
5613 pfd_confirm(c->u.pfd.pf);
5616 if (c && c->pending_eof) {
5618 * We have a pending close on this channel,
5619 * which we decided on before the server acked
5620 * the channel open. So now we know the
5621 * remoteid, we can close it again.
5623 ssh_channel_try_eof(c);
5627 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5629 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5630 struct ssh_channel *c;
5632 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5633 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5634 logevent("Forwarded connection refused by server");
5635 pfd_close(c->u.pfd.pf);
5636 del234(ssh->channels, c);
5641 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
5643 /* Remote side closes a channel. */
5644 unsigned i = ssh_pkt_getuint32(pktin);
5645 struct ssh_channel *c;
5646 c = find234(ssh->channels, &i, ssh_channelfind);
5647 if (c && !c->halfopen) {
5649 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
5650 !(c->closes & CLOSES_RCVD_EOF)) {
5652 * Received CHANNEL_CLOSE, which we translate into
5655 int send_close = FALSE;
5657 c->closes |= CLOSES_RCVD_EOF;
5662 x11_send_eof(c->u.x11.xconn);
5668 pfd_send_eof(c->u.pfd.pf);
5677 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
5678 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
5680 c->closes |= CLOSES_SENT_EOF;
5684 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
5685 !(c->closes & CLOSES_RCVD_CLOSE)) {
5687 if (!(c->closes & CLOSES_SENT_EOF)) {
5688 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
5689 " for which we never sent CHANNEL_CLOSE\n", i));
5692 c->closes |= CLOSES_RCVD_CLOSE;
5695 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
5696 !(c->closes & CLOSES_SENT_CLOSE)) {
5697 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
5698 PKT_INT, c->remoteid, PKT_END);
5699 c->closes |= CLOSES_SENT_CLOSE;
5702 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5703 ssh_channel_destroy(c);
5705 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5706 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
5707 "_CONFIRMATION", c ? "half-open" : "nonexistent",
5712 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5714 /* Data sent down one of our channels. */
5715 int i = ssh_pkt_getuint32(pktin);
5718 struct ssh_channel *c;
5720 ssh_pkt_getstring(pktin, &p, &len);
5722 c = find234(ssh->channels, &i, ssh_channelfind);
5727 bufsize = x11_send(c->u.x11.xconn, p, len);
5730 bufsize = pfd_send(c->u.pfd.pf, p, len);
5733 /* Data for an agent message. Buffer it. */
5735 if (c->u.a.lensofar < 4) {
5736 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
5737 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
5741 c->u.a.lensofar += l;
5743 if (c->u.a.lensofar == 4) {
5745 4 + GET_32BIT(c->u.a.msglen);
5746 c->u.a.message = snewn(c->u.a.totallen,
5748 memcpy(c->u.a.message, c->u.a.msglen, 4);
5750 if (c->u.a.lensofar >= 4 && len > 0) {
5752 min(c->u.a.totallen - c->u.a.lensofar,
5754 memcpy(c->u.a.message + c->u.a.lensofar, p,
5758 c->u.a.lensofar += l;
5760 if (c->u.a.lensofar == c->u.a.totallen) {
5763 c->u.a.outstanding_requests++;
5764 if (agent_query(c->u.a.message,
5767 ssh_agentf_callback, c))
5768 ssh_agentf_callback(c, reply, replylen);
5769 sfree(c->u.a.message);
5770 c->u.a.lensofar = 0;
5773 bufsize = 0; /* agent channels never back up */
5776 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5777 c->throttling_conn = 1;
5778 ssh_throttle_conn(ssh, +1);
5783 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5785 ssh->exitcode = ssh_pkt_getuint32(pktin);
5786 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5787 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5789 * In case `helpful' firewalls or proxies tack
5790 * extra human-readable text on the end of the
5791 * session which we might mistake for another
5792 * encrypted packet, we close the session once
5793 * we've sent EXIT_CONFIRMATION.
5795 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5798 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5799 static void ssh1_send_ttymode(void *data, char *mode, char *val)
5801 struct Packet *pktout = (struct Packet *)data;
5803 unsigned int arg = 0;
5804 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5805 if (i == lenof(ssh_ttymodes)) return;
5806 switch (ssh_ttymodes[i].type) {
5808 arg = ssh_tty_parse_specchar(val);
5811 arg = ssh_tty_parse_boolean(val);
5814 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5815 ssh2_pkt_addbyte(pktout, arg);
5818 int ssh_agent_forwarding_permitted(Ssh ssh)
5820 return conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists();
5823 static void do_ssh1_connection(Ssh ssh, const unsigned char *in, int inlen,
5824 struct Packet *pktin)
5826 crBegin(ssh->do_ssh1_connection_crstate);
5828 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5829 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5830 ssh1_smsg_stdout_stderr_data;
5832 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5833 ssh1_msg_channel_open_confirmation;
5834 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5835 ssh1_msg_channel_open_failure;
5836 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5837 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5838 ssh1_msg_channel_close;
5839 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5840 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5842 if (ssh_agent_forwarding_permitted(ssh)) {
5843 logevent("Requesting agent forwarding");
5844 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5848 if (pktin->type != SSH1_SMSG_SUCCESS
5849 && pktin->type != SSH1_SMSG_FAILURE) {
5850 bombout(("Protocol confusion"));
5852 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5853 logevent("Agent forwarding refused");
5855 logevent("Agent forwarding enabled");
5856 ssh->agentfwd_enabled = TRUE;
5857 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5861 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
5863 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5865 if (!ssh->x11disp) {
5866 /* FIXME: return an error message from x11_setup_display */
5867 logevent("X11 forwarding not enabled: unable to"
5868 " initialise X display");
5870 ssh->x11auth = x11_invent_fake_auth
5871 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
5872 ssh->x11auth->disp = ssh->x11disp;
5874 logevent("Requesting X11 forwarding");
5875 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5876 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5877 PKT_STR, ssh->x11auth->protoname,
5878 PKT_STR, ssh->x11auth->datastring,
5879 PKT_INT, ssh->x11disp->screennum,
5882 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5883 PKT_STR, ssh->x11auth->protoname,
5884 PKT_STR, ssh->x11auth->datastring,
5890 if (pktin->type != SSH1_SMSG_SUCCESS
5891 && pktin->type != SSH1_SMSG_FAILURE) {
5892 bombout(("Protocol confusion"));
5894 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5895 logevent("X11 forwarding refused");
5897 logevent("X11 forwarding enabled");
5898 ssh->X11_fwd_enabled = TRUE;
5899 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5904 ssh_setup_portfwd(ssh, ssh->conf);
5905 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5907 if (!conf_get_int(ssh->conf, CONF_nopty)) {
5909 /* Unpick the terminal-speed string. */
5910 /* XXX perhaps we should allow no speeds to be sent. */
5911 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5912 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
5913 /* Send the pty request. */
5914 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5915 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
5916 ssh_pkt_adduint32(pkt, ssh->term_height);
5917 ssh_pkt_adduint32(pkt, ssh->term_width);
5918 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5919 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5920 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
5921 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5922 ssh_pkt_adduint32(pkt, ssh->ispeed);
5923 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5924 ssh_pkt_adduint32(pkt, ssh->ospeed);
5925 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5927 ssh->state = SSH_STATE_INTERMED;
5931 if (pktin->type != SSH1_SMSG_SUCCESS
5932 && pktin->type != SSH1_SMSG_FAILURE) {
5933 bombout(("Protocol confusion"));
5935 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5936 c_write_str(ssh, "Server refused to allocate pty\r\n");
5937 ssh->editing = ssh->echoing = 1;
5939 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5940 ssh->ospeed, ssh->ispeed);
5941 ssh->got_pty = TRUE;
5944 ssh->editing = ssh->echoing = 1;
5947 if (conf_get_int(ssh->conf, CONF_compression)) {
5948 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5952 if (pktin->type != SSH1_SMSG_SUCCESS
5953 && pktin->type != SSH1_SMSG_FAILURE) {
5954 bombout(("Protocol confusion"));
5956 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5957 c_write_str(ssh, "Server refused to compress\r\n");
5959 logevent("Started compression");
5960 ssh->v1_compressing = TRUE;
5961 ssh->cs_comp_ctx = zlib_compress_init();
5962 logevent("Initialised zlib (RFC1950) compression");
5963 ssh->sc_comp_ctx = zlib_decompress_init();
5964 logevent("Initialised zlib (RFC1950) decompression");
5968 * Start the shell or command.
5970 * Special case: if the first-choice command is an SSH-2
5971 * subsystem (hence not usable here) and the second choice
5972 * exists, we fall straight back to that.
5975 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
5977 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
5978 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
5979 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
5980 ssh->fallback_cmd = TRUE;
5983 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
5985 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
5986 logevent("Started session");
5989 ssh->state = SSH_STATE_SESSION;
5990 if (ssh->size_needed)
5991 ssh_size(ssh, ssh->term_width, ssh->term_height);
5992 if (ssh->eof_needed)
5993 ssh_special(ssh, TS_EOF);
5996 ldisc_echoedit_update(ssh->ldisc); /* cause ldisc to notice changes */
5998 ssh->channels = newtree234(ssh_channelcmp);
6002 * By this point, most incoming packets are already being
6003 * handled by the dispatch table, and we need only pay
6004 * attention to the unusual ones.
6009 if (pktin->type == SSH1_SMSG_SUCCESS) {
6010 /* may be from EXEC_SHELL on some servers */
6011 } else if (pktin->type == SSH1_SMSG_FAILURE) {
6012 /* may be from EXEC_SHELL on some servers
6013 * if no pty is available or in other odd cases. Ignore */
6015 bombout(("Strange packet received: type %d", pktin->type));
6020 int len = min(inlen, 512);
6021 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
6022 PKT_INT, len, PKT_DATA, in, len,
6034 * Handle the top-level SSH-2 protocol.
6036 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
6041 ssh_pkt_getstring(pktin, &msg, &msglen);
6042 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
6045 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
6047 /* log reason code in disconnect message */
6051 ssh_pkt_getstring(pktin, &msg, &msglen);
6052 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
6055 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
6057 /* Do nothing, because we're ignoring it! Duhh. */
6060 static void ssh1_protocol_setup(Ssh ssh)
6065 * Most messages are handled by the coroutines.
6067 for (i = 0; i < 256; i++)
6068 ssh->packet_dispatch[i] = NULL;
6071 * These special message types we install handlers for.
6073 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
6074 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
6075 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
6078 static void ssh1_protocol(Ssh ssh, const void *vin, int inlen,
6079 struct Packet *pktin)
6081 const unsigned char *in = (const unsigned char *)vin;
6082 if (ssh->state == SSH_STATE_CLOSED)
6085 if (pktin && ssh->packet_dispatch[pktin->type]) {
6086 ssh->packet_dispatch[pktin->type](ssh, pktin);
6090 if (!ssh->protocol_initial_phase_done) {
6091 if (do_ssh1_login(ssh, in, inlen, pktin))
6092 ssh->protocol_initial_phase_done = TRUE;
6097 do_ssh1_connection(ssh, in, inlen, pktin);
6101 * Utility routines for decoding comma-separated strings in KEXINIT.
6103 static int first_in_commasep_string(char const *needle, char const *haystack,
6107 if (!needle || !haystack) /* protect against null pointers */
6109 needlen = strlen(needle);
6111 if (haylen >= needlen && /* haystack is long enough */
6112 !memcmp(needle, haystack, needlen) && /* initial match */
6113 (haylen == needlen || haystack[needlen] == ',')
6114 /* either , or EOS follows */
6120 static int in_commasep_string(char const *needle, char const *haystack,
6125 if (!needle || !haystack) /* protect against null pointers */
6128 * Is it at the start of the string?
6130 if (first_in_commasep_string(needle, haystack, haylen))
6133 * If not, search for the next comma and resume after that.
6134 * If no comma found, terminate.
6136 p = memchr(haystack, ',', haylen);
6138 /* + 1 to skip over comma */
6139 return in_commasep_string(needle, p + 1, haylen - (p + 1 - haystack));
6143 * Add a value to the comma-separated string at the end of the packet.
6145 static void ssh2_pkt_addstring_commasep(struct Packet *pkt, const char *data)
6147 if (pkt->length - pkt->savedpos > 0)
6148 ssh_pkt_addstring_str(pkt, ",");
6149 ssh_pkt_addstring_str(pkt, data);
6154 * SSH-2 key derivation (RFC 4253 section 7.2).
6156 static unsigned char *ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
6157 char chr, int keylen)
6159 const struct ssh_hash *h = ssh->kex->hash;
6167 /* Round up to the next multiple of hash length. */
6168 keylen_padded = ((keylen + h->hlen - 1) / h->hlen) * h->hlen;
6170 key = snewn(keylen_padded, unsigned char);
6172 /* First hlen bytes. */
6174 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6175 hash_mpint(h, s, K);
6176 h->bytes(s, H, h->hlen);
6177 h->bytes(s, &chr, 1);
6178 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
6181 /* Subsequent blocks of hlen bytes. */
6182 if (keylen_padded > h->hlen) {
6186 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6187 hash_mpint(h, s, K);
6188 h->bytes(s, H, h->hlen);
6190 for (offset = h->hlen; offset < keylen_padded; offset += h->hlen) {
6191 h->bytes(s, key + offset - h->hlen, h->hlen);
6193 h->final(s2, key + offset);
6199 /* Now clear any extra bytes of key material beyond the length
6200 * we're officially returning, because the caller won't know to
6202 if (keylen_padded > keylen)
6203 smemclr(key + keylen, keylen_padded - keylen);
6209 * Structure for constructing KEXINIT algorithm lists.
6211 #define MAXKEXLIST 16
6212 struct kexinit_algorithm {
6216 const struct ssh_kex *kex;
6219 const struct ssh_signkey *hostkey;
6221 const struct ssh2_cipher *cipher;
6225 const struct ssh_mac *mac;
6228 const struct ssh_compress *comp;
6233 * Find a slot in a KEXINIT algorithm list to use for a new algorithm.
6234 * If the algorithm is already in the list, return a pointer to its
6235 * entry, otherwise return an entry from the end of the list.
6236 * This assumes that every time a particular name is passed in, it
6237 * comes from the same string constant. If this isn't true, this
6238 * function may need to be rewritten to use strcmp() instead.
6240 static struct kexinit_algorithm *ssh2_kexinit_addalg(struct kexinit_algorithm
6241 *list, const char *name)
6245 for (i = 0; i < MAXKEXLIST; i++)
6246 if (list[i].name == NULL || list[i].name == name) {
6247 list[i].name = name;
6250 assert(!"No space in KEXINIT list");
6255 * Handle the SSH-2 transport layer.
6257 static void do_ssh2_transport(Ssh ssh, const void *vin, int inlen,
6258 struct Packet *pktin)
6260 const unsigned char *in = (const unsigned char *)vin;
6262 KEXLIST_KEX, KEXLIST_HOSTKEY, KEXLIST_CSCIPHER, KEXLIST_SCCIPHER,
6263 KEXLIST_CSMAC, KEXLIST_SCMAC, KEXLIST_CSCOMP, KEXLIST_SCCOMP,
6266 const char * kexlist_descr[NKEXLIST] = {
6267 "key exchange algorithm", "host key algorithm",
6268 "client-to-server cipher", "server-to-client cipher",
6269 "client-to-server MAC", "server-to-client MAC",
6270 "client-to-server compression method",
6271 "server-to-client compression method" };
6272 struct do_ssh2_transport_state {
6274 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
6275 Bignum p, g, e, f, K;
6278 int kex_init_value, kex_reply_value;
6279 const struct ssh_mac **maclist;
6281 const struct ssh2_cipher *cscipher_tobe;
6282 const struct ssh2_cipher *sccipher_tobe;
6283 const struct ssh_mac *csmac_tobe;
6284 const struct ssh_mac *scmac_tobe;
6285 int csmac_etm_tobe, scmac_etm_tobe;
6286 const struct ssh_compress *cscomp_tobe;
6287 const struct ssh_compress *sccomp_tobe;
6288 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
6289 int hostkeylen, siglen, rsakeylen;
6290 void *hkey; /* actual host key */
6291 void *rsakey; /* for RSA kex */
6292 void *eckey; /* for ECDH kex */
6293 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
6294 int n_preferred_kex;
6295 const struct ssh_kexes *preferred_kex[KEX_MAX];
6296 int n_preferred_ciphers;
6297 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
6298 const struct ssh_compress *preferred_comp;
6299 int userauth_succeeded; /* for delayed compression */
6300 int pending_compression;
6301 int got_session_id, activated_authconn;
6302 struct Packet *pktout;
6306 struct kexinit_algorithm kexlists[NKEXLIST][MAXKEXLIST];
6308 crState(do_ssh2_transport_state);
6310 assert(!ssh->bare_connection);
6314 s->cscipher_tobe = s->sccipher_tobe = NULL;
6315 s->csmac_tobe = s->scmac_tobe = NULL;
6316 s->cscomp_tobe = s->sccomp_tobe = NULL;
6318 s->got_session_id = s->activated_authconn = FALSE;
6319 s->userauth_succeeded = FALSE;
6320 s->pending_compression = FALSE;
6323 * Be prepared to work around the buggy MAC problem.
6325 if (ssh->remote_bugs & BUG_SSH2_HMAC)
6326 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
6328 s->maclist = macs, s->nmacs = lenof(macs);
6331 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
6334 struct kexinit_algorithm *alg;
6337 * Set up the preferred key exchange. (NULL => warn below here)
6339 s->n_preferred_kex = 0;
6340 for (i = 0; i < KEX_MAX; i++) {
6341 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
6343 s->preferred_kex[s->n_preferred_kex++] =
6344 &ssh_diffiehellman_gex;
6347 s->preferred_kex[s->n_preferred_kex++] =
6348 &ssh_diffiehellman_group14;
6351 s->preferred_kex[s->n_preferred_kex++] =
6352 &ssh_diffiehellman_group1;
6355 s->preferred_kex[s->n_preferred_kex++] =
6359 s->preferred_kex[s->n_preferred_kex++] =
6363 /* Flag for later. Don't bother if it's the last in
6365 if (i < KEX_MAX - 1) {
6366 s->preferred_kex[s->n_preferred_kex++] = NULL;
6373 * Set up the preferred ciphers. (NULL => warn below here)
6375 s->n_preferred_ciphers = 0;
6376 for (i = 0; i < CIPHER_MAX; i++) {
6377 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
6378 case CIPHER_BLOWFISH:
6379 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
6382 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
6383 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
6387 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
6390 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
6392 case CIPHER_ARCFOUR:
6393 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
6395 case CIPHER_CHACHA20:
6396 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_ccp;
6399 /* Flag for later. Don't bother if it's the last in
6401 if (i < CIPHER_MAX - 1) {
6402 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
6409 * Set up preferred compression.
6411 if (conf_get_int(ssh->conf, CONF_compression))
6412 s->preferred_comp = &ssh_zlib;
6414 s->preferred_comp = &ssh_comp_none;
6417 * Enable queueing of outgoing auth- or connection-layer
6418 * packets while we are in the middle of a key exchange.
6420 ssh->queueing = TRUE;
6423 * Flag that KEX is in progress.
6425 ssh->kex_in_progress = TRUE;
6427 for (i = 0; i < NKEXLIST; i++)
6428 for (j = 0; j < MAXKEXLIST; j++)
6429 s->kexlists[i][j].name = NULL;
6430 /* List key exchange algorithms. */
6432 for (i = 0; i < s->n_preferred_kex; i++) {
6433 const struct ssh_kexes *k = s->preferred_kex[i];
6434 if (!k) warn = TRUE;
6435 else for (j = 0; j < k->nkexes; j++) {
6436 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_KEX],
6438 alg->u.kex.kex = k->list[j];
6439 alg->u.kex.warn = warn;
6442 /* List server host key algorithms. */
6443 if (!s->got_session_id) {
6445 * In the first key exchange, we list all the algorithms
6446 * we're prepared to cope with, but prefer those algorithms
6447 * for which we have a host key for this host.
6449 for (i = 0; i < lenof(hostkey_algs); i++) {
6450 if (have_ssh_host_key(ssh->savedhost, ssh->savedport,
6451 hostkey_algs[i]->keytype)) {
6452 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY],
6453 hostkey_algs[i]->name);
6454 alg->u.hostkey = hostkey_algs[i];
6457 for (i = 0; i < lenof(hostkey_algs); i++) {
6458 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY],
6459 hostkey_algs[i]->name);
6460 alg->u.hostkey = hostkey_algs[i];
6464 * In subsequent key exchanges, we list only the kex
6465 * algorithm that was selected in the first key exchange,
6466 * so that we keep getting the same host key and hence
6467 * don't have to interrupt the user's session to ask for
6471 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY],
6472 ssh->hostkey->name);
6473 alg->u.hostkey = ssh->hostkey;
6475 /* List encryption algorithms (client->server then server->client). */
6476 for (k = KEXLIST_CSCIPHER; k <= KEXLIST_SCCIPHER; k++) {
6478 for (i = 0; i < s->n_preferred_ciphers; i++) {
6479 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6480 if (!c) warn = TRUE;
6481 else for (j = 0; j < c->nciphers; j++) {
6482 alg = ssh2_kexinit_addalg(s->kexlists[k],
6484 alg->u.cipher.cipher = c->list[j];
6485 alg->u.cipher.warn = warn;
6489 /* List MAC algorithms (client->server then server->client). */
6490 for (j = KEXLIST_CSMAC; j <= KEXLIST_SCMAC; j++) {
6491 for (i = 0; i < s->nmacs; i++) {
6492 alg = ssh2_kexinit_addalg(s->kexlists[j], s->maclist[i]->name);
6493 alg->u.mac.mac = s->maclist[i];
6494 alg->u.mac.etm = FALSE;
6496 for (i = 0; i < s->nmacs; i++)
6497 /* For each MAC, there may also be an ETM version,
6498 * which we list second. */
6499 if (s->maclist[i]->etm_name) {
6500 alg = ssh2_kexinit_addalg(s->kexlists[j],
6501 s->maclist[i]->etm_name);
6502 alg->u.mac.mac = s->maclist[i];
6503 alg->u.mac.etm = TRUE;
6506 /* List client->server compression algorithms,
6507 * then server->client compression algorithms. (We use the
6508 * same set twice.) */
6509 for (j = KEXLIST_CSCOMP; j <= KEXLIST_SCCOMP; j++) {
6510 assert(lenof(compressions) > 1);
6511 /* Prefer non-delayed versions */
6512 alg = ssh2_kexinit_addalg(s->kexlists[j], s->preferred_comp->name);
6513 alg->u.comp = s->preferred_comp;
6514 /* We don't even list delayed versions of algorithms until
6515 * they're allowed to be used, to avoid a race. See the end of
6517 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
6518 alg = ssh2_kexinit_addalg(s->kexlists[j],
6519 s->preferred_comp->delayed_name);
6520 alg->u.comp = s->preferred_comp;
6522 for (i = 0; i < lenof(compressions); i++) {
6523 const struct ssh_compress *c = compressions[i];
6524 alg = ssh2_kexinit_addalg(s->kexlists[j], c->name);
6526 if (s->userauth_succeeded && c->delayed_name) {
6527 alg = ssh2_kexinit_addalg(s->kexlists[j], c->delayed_name);
6533 * Construct and send our key exchange packet.
6535 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
6536 for (i = 0; i < 16; i++)
6537 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
6538 for (i = 0; i < NKEXLIST; i++) {
6539 ssh2_pkt_addstring_start(s->pktout);
6540 for (j = 0; j < MAXKEXLIST; j++) {
6541 if (s->kexlists[i][j].name == NULL) break;
6542 ssh2_pkt_addstring_commasep(s->pktout, s->kexlists[i][j].name);
6545 /* List client->server languages. Empty list. */
6546 ssh2_pkt_addstring_start(s->pktout);
6547 /* List server->client languages. Empty list. */
6548 ssh2_pkt_addstring_start(s->pktout);
6549 /* First KEX packet does _not_ follow, because we're not that brave. */
6550 ssh2_pkt_addbool(s->pktout, FALSE);
6552 ssh2_pkt_adduint32(s->pktout, 0);
6555 s->our_kexinitlen = s->pktout->length - 5;
6556 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
6557 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
6559 ssh2_pkt_send_noqueue(ssh, s->pktout);
6562 crWaitUntilV(pktin);
6565 * Now examine the other side's KEXINIT to see what we're up
6572 if (pktin->type != SSH2_MSG_KEXINIT) {
6573 bombout(("expected key exchange packet from server"));
6577 ssh->hostkey = NULL;
6578 s->cscipher_tobe = NULL;
6579 s->sccipher_tobe = NULL;
6580 s->csmac_tobe = NULL;
6581 s->scmac_tobe = NULL;
6582 s->cscomp_tobe = NULL;
6583 s->sccomp_tobe = NULL;
6584 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
6586 pktin->savedpos += 16; /* skip garbage cookie */
6589 for (i = 0; i < NKEXLIST; i++) {
6590 ssh_pkt_getstring(pktin, &str, &len);
6592 bombout(("KEXINIT packet was incomplete"));
6596 /* If we've already selected a cipher which requires a
6597 * particular MAC, then just select that, and don't even
6598 * bother looking through the server's KEXINIT string for
6600 if (i == KEXLIST_CSMAC && s->cscipher_tobe &&
6601 s->cscipher_tobe->required_mac) {
6602 s->csmac_tobe = s->cscipher_tobe->required_mac;
6603 s->csmac_etm_tobe = !!(s->csmac_tobe->etm_name);
6606 if (i == KEXLIST_SCMAC && s->sccipher_tobe &&
6607 s->sccipher_tobe->required_mac) {
6608 s->scmac_tobe = s->sccipher_tobe->required_mac;
6609 s->scmac_etm_tobe = !!(s->scmac_tobe->etm_name);
6613 for (j = 0; j < MAXKEXLIST; j++) {
6614 struct kexinit_algorithm *alg = &s->kexlists[i][j];
6615 if (alg->name == NULL) break;
6616 if (in_commasep_string(alg->name, str, len)) {
6617 /* We've found a matching algorithm. */
6618 if (i == KEXLIST_KEX || i == KEXLIST_HOSTKEY) {
6619 /* Check if we might need to ignore first kex pkt */
6621 !first_in_commasep_string(alg->name, str, len))
6624 if (i == KEXLIST_KEX) {
6625 ssh->kex = alg->u.kex.kex;
6626 s->warn_kex = alg->u.kex.warn;
6627 } else if (i == KEXLIST_HOSTKEY) {
6628 ssh->hostkey = alg->u.hostkey;
6629 } else if (i == KEXLIST_CSCIPHER) {
6630 s->cscipher_tobe = alg->u.cipher.cipher;
6631 s->warn_cscipher = alg->u.cipher.warn;
6632 } else if (i == KEXLIST_SCCIPHER) {
6633 s->sccipher_tobe = alg->u.cipher.cipher;
6634 s->warn_sccipher = alg->u.cipher.warn;
6635 } else if (i == KEXLIST_CSMAC) {
6636 s->csmac_tobe = alg->u.mac.mac;
6637 s->csmac_etm_tobe = alg->u.mac.etm;
6638 } else if (i == KEXLIST_SCMAC) {
6639 s->scmac_tobe = alg->u.mac.mac;
6640 s->scmac_etm_tobe = alg->u.mac.etm;
6641 } else if (i == KEXLIST_CSCOMP) {
6642 s->cscomp_tobe = alg->u.comp;
6643 } else if (i == KEXLIST_SCCOMP) {
6644 s->sccomp_tobe = alg->u.comp;
6648 if ((i == KEXLIST_CSCOMP || i == KEXLIST_SCCOMP) &&
6649 in_commasep_string(alg->u.comp->delayed_name, str, len))
6650 s->pending_compression = TRUE; /* try this later */
6652 bombout(("Couldn't agree a %s ((available: %.*s)",
6653 kexlist_descr[i], len, str));
6658 if (s->pending_compression) {
6659 logevent("Server supports delayed compression; "
6660 "will try this later");
6662 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
6663 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
6664 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
6666 ssh->exhash = ssh->kex->hash->init();
6667 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
6668 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
6669 hash_string(ssh->kex->hash, ssh->exhash,
6670 s->our_kexinit, s->our_kexinitlen);
6671 sfree(s->our_kexinit);
6672 /* Include the type byte in the hash of server's KEXINIT */
6673 hash_string(ssh->kex->hash, ssh->exhash,
6674 pktin->body - 1, pktin->length + 1);
6677 ssh_set_frozen(ssh, 1);
6678 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
6680 ssh_dialog_callback, ssh);
6681 if (s->dlgret < 0) {
6685 bombout(("Unexpected data from server while"
6686 " waiting for user response"));
6689 } while (pktin || inlen > 0);
6690 s->dlgret = ssh->user_response;
6692 ssh_set_frozen(ssh, 0);
6693 if (s->dlgret == 0) {
6694 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
6700 if (s->warn_cscipher) {
6701 ssh_set_frozen(ssh, 1);
6702 s->dlgret = askalg(ssh->frontend,
6703 "client-to-server cipher",
6704 s->cscipher_tobe->name,
6705 ssh_dialog_callback, ssh);
6706 if (s->dlgret < 0) {
6710 bombout(("Unexpected data from server while"
6711 " waiting for user response"));
6714 } while (pktin || inlen > 0);
6715 s->dlgret = ssh->user_response;
6717 ssh_set_frozen(ssh, 0);
6718 if (s->dlgret == 0) {
6719 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6725 if (s->warn_sccipher) {
6726 ssh_set_frozen(ssh, 1);
6727 s->dlgret = askalg(ssh->frontend,
6728 "server-to-client cipher",
6729 s->sccipher_tobe->name,
6730 ssh_dialog_callback, ssh);
6731 if (s->dlgret < 0) {
6735 bombout(("Unexpected data from server while"
6736 " waiting for user response"));
6739 } while (pktin || inlen > 0);
6740 s->dlgret = ssh->user_response;
6742 ssh_set_frozen(ssh, 0);
6743 if (s->dlgret == 0) {
6744 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6750 if (s->ignorepkt) /* first_kex_packet_follows */
6751 crWaitUntilV(pktin); /* Ignore packet */
6754 if (ssh->kex->main_type == KEXTYPE_DH) {
6756 * Work out the number of bits of key we will need from the
6757 * key exchange. We start with the maximum key length of
6763 csbits = s->cscipher_tobe->real_keybits;
6764 scbits = s->sccipher_tobe->real_keybits;
6765 s->nbits = (csbits > scbits ? csbits : scbits);
6767 /* The keys only have hlen-bit entropy, since they're based on
6768 * a hash. So cap the key size at hlen bits. */
6769 if (s->nbits > ssh->kex->hash->hlen * 8)
6770 s->nbits = ssh->kex->hash->hlen * 8;
6773 * If we're doing Diffie-Hellman group exchange, start by
6774 * requesting a group.
6776 if (dh_is_gex(ssh->kex)) {
6777 logevent("Doing Diffie-Hellman group exchange");
6778 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
6780 * Work out how big a DH group we will need to allow that
6783 s->pbits = 512 << ((s->nbits - 1) / 64);
6784 if (s->pbits < DH_MIN_SIZE)
6785 s->pbits = DH_MIN_SIZE;
6786 if (s->pbits > DH_MAX_SIZE)
6787 s->pbits = DH_MAX_SIZE;
6788 if ((ssh->remote_bugs & BUG_SSH2_OLDGEX)) {
6789 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST_OLD);
6790 ssh2_pkt_adduint32(s->pktout, s->pbits);
6792 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6793 ssh2_pkt_adduint32(s->pktout, DH_MIN_SIZE);
6794 ssh2_pkt_adduint32(s->pktout, s->pbits);
6795 ssh2_pkt_adduint32(s->pktout, DH_MAX_SIZE);
6797 ssh2_pkt_send_noqueue(ssh, s->pktout);
6799 crWaitUntilV(pktin);
6800 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6801 bombout(("expected key exchange group packet from server"));
6804 s->p = ssh2_pkt_getmp(pktin);
6805 s->g = ssh2_pkt_getmp(pktin);
6806 if (!s->p || !s->g) {
6807 bombout(("unable to read mp-ints from incoming group packet"));
6810 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6811 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6812 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6814 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
6815 ssh->kex_ctx = dh_setup_group(ssh->kex);
6816 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6817 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6818 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6819 ssh->kex->groupname);
6822 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6823 ssh->kex->hash->text_name);
6825 * Now generate and send e for Diffie-Hellman.
6827 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6828 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6829 s->pktout = ssh2_pkt_init(s->kex_init_value);
6830 ssh2_pkt_addmp(s->pktout, s->e);
6831 ssh2_pkt_send_noqueue(ssh, s->pktout);
6833 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
6834 crWaitUntilV(pktin);
6835 if (pktin->type != s->kex_reply_value) {
6836 bombout(("expected key exchange reply packet from server"));
6839 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
6840 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6841 if (!s->hostkeydata) {
6842 bombout(("unable to parse key exchange reply packet"));
6845 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
6846 s->hostkeydata, s->hostkeylen);
6847 s->f = ssh2_pkt_getmp(pktin);
6849 bombout(("unable to parse key exchange reply packet"));
6852 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6854 bombout(("unable to parse key exchange reply packet"));
6859 const char *err = dh_validate_f(ssh->kex_ctx, s->f);
6861 bombout(("key exchange reply failed validation: %s", err));
6865 s->K = dh_find_K(ssh->kex_ctx, s->f);
6867 /* We assume everything from now on will be quick, and it might
6868 * involve user interaction. */
6869 set_busy_status(ssh->frontend, BUSY_NOT);
6871 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6872 if (dh_is_gex(ssh->kex)) {
6873 if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX))
6874 hash_uint32(ssh->kex->hash, ssh->exhash, DH_MIN_SIZE);
6875 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
6876 if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX))
6877 hash_uint32(ssh->kex->hash, ssh->exhash, DH_MAX_SIZE);
6878 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
6879 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
6881 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
6882 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
6884 dh_cleanup(ssh->kex_ctx);
6886 if (dh_is_gex(ssh->kex)) {
6890 } else if (ssh->kex->main_type == KEXTYPE_ECDH) {
6892 logeventf(ssh, "Doing ECDH key exchange with curve %s and hash %s",
6893 ssh_ecdhkex_curve_textname(ssh->kex),
6894 ssh->kex->hash->text_name);
6895 ssh->pkt_kctx = SSH2_PKTCTX_ECDHKEX;
6897 s->eckey = ssh_ecdhkex_newkey(ssh->kex);
6899 bombout(("Unable to generate key for ECDH"));
6905 int publicPointLength;
6906 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
6908 ssh_ecdhkex_freekey(s->eckey);
6909 bombout(("Unable to encode public key for ECDH"));
6912 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_ECDH_INIT);
6913 ssh2_pkt_addstring_start(s->pktout);
6914 ssh2_pkt_addstring_data(s->pktout, publicPoint, publicPointLength);
6918 ssh2_pkt_send_noqueue(ssh, s->pktout);
6920 crWaitUntilV(pktin);
6921 if (pktin->type != SSH2_MSG_KEX_ECDH_REPLY) {
6922 ssh_ecdhkex_freekey(s->eckey);
6923 bombout(("expected ECDH reply packet from server"));
6927 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6928 if (!s->hostkeydata) {
6929 bombout(("unable to parse ECDH reply packet"));
6932 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6933 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
6934 s->hostkeydata, s->hostkeylen);
6938 int publicPointLength;
6939 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
6941 ssh_ecdhkex_freekey(s->eckey);
6942 bombout(("Unable to encode public key for ECDH hash"));
6945 hash_string(ssh->kex->hash, ssh->exhash,
6946 publicPoint, publicPointLength);
6953 ssh_pkt_getstring(pktin, &keydata, &keylen);
6955 bombout(("unable to parse ECDH reply packet"));
6958 hash_string(ssh->kex->hash, ssh->exhash, keydata, keylen);
6959 s->K = ssh_ecdhkex_getkey(s->eckey, keydata, keylen);
6961 ssh_ecdhkex_freekey(s->eckey);
6962 bombout(("point received in ECDH was not valid"));
6967 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6969 bombout(("unable to parse key exchange reply packet"));
6973 ssh_ecdhkex_freekey(s->eckey);
6975 logeventf(ssh, "Doing RSA key exchange with hash %s",
6976 ssh->kex->hash->text_name);
6977 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
6979 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6982 crWaitUntilV(pktin);
6983 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
6984 bombout(("expected RSA public key packet from server"));
6988 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6989 if (!s->hostkeydata) {
6990 bombout(("unable to parse RSA public key packet"));
6993 hash_string(ssh->kex->hash, ssh->exhash,
6994 s->hostkeydata, s->hostkeylen);
6995 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
6996 s->hostkeydata, s->hostkeylen);
7000 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
7002 bombout(("unable to parse RSA public key packet"));
7005 s->rsakeydata = snewn(s->rsakeylen, char);
7006 memcpy(s->rsakeydata, keydata, s->rsakeylen);
7009 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
7011 sfree(s->rsakeydata);
7012 bombout(("unable to parse RSA public key from server"));
7016 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
7019 * Next, set up a shared secret K, of precisely KLEN -
7020 * 2*HLEN - 49 bits, where KLEN is the bit length of the
7021 * RSA key modulus and HLEN is the bit length of the hash
7025 int klen = ssh_rsakex_klen(s->rsakey);
7026 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
7028 unsigned char *kstr1, *kstr2, *outstr;
7029 int kstr1len, kstr2len, outstrlen;
7031 s->K = bn_power_2(nbits - 1);
7033 for (i = 0; i < nbits; i++) {
7035 byte = random_byte();
7037 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
7041 * Encode this as an mpint.
7043 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
7044 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
7045 PUT_32BIT(kstr2, kstr1len);
7046 memcpy(kstr2 + 4, kstr1, kstr1len);
7049 * Encrypt it with the given RSA key.
7051 outstrlen = (klen + 7) / 8;
7052 outstr = snewn(outstrlen, unsigned char);
7053 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
7054 outstr, outstrlen, s->rsakey);
7057 * And send it off in a return packet.
7059 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
7060 ssh2_pkt_addstring_start(s->pktout);
7061 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
7062 ssh2_pkt_send_noqueue(ssh, s->pktout);
7064 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
7071 ssh_rsakex_freekey(s->rsakey);
7073 crWaitUntilV(pktin);
7074 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
7075 sfree(s->rsakeydata);
7076 bombout(("expected signature packet from server"));
7080 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
7082 bombout(("unable to parse signature packet"));
7086 sfree(s->rsakeydata);
7089 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
7090 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
7091 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
7093 ssh->kex_ctx = NULL;
7096 debug(("Exchange hash is:\n"));
7097 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
7101 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
7102 (char *)s->exchange_hash,
7103 ssh->kex->hash->hlen)) {
7104 bombout(("Server's host key did not match the signature supplied"));
7108 s->keystr = ssh->hostkey->fmtkey(s->hkey);
7109 if (!s->got_session_id) {
7111 * Authenticate remote host: verify host key. (We've already
7112 * checked the signature of the exchange hash.)
7114 s->fingerprint = ssh2_fingerprint(ssh->hostkey, s->hkey);
7115 logevent("Host key fingerprint is:");
7116 logevent(s->fingerprint);
7117 /* First check against manually configured host keys. */
7118 s->dlgret = verify_ssh_manual_host_key(ssh, s->fingerprint,
7119 ssh->hostkey, s->hkey);
7120 if (s->dlgret == 0) { /* did not match */
7121 bombout(("Host key did not appear in manually configured list"));
7123 } else if (s->dlgret < 0) { /* none configured; use standard handling */
7124 ssh_set_frozen(ssh, 1);
7125 s->dlgret = verify_ssh_host_key(ssh->frontend,
7126 ssh->savedhost, ssh->savedport,
7127 ssh->hostkey->keytype, s->keystr,
7129 ssh_dialog_callback, ssh);
7130 if (s->dlgret < 0) {
7134 bombout(("Unexpected data from server while waiting"
7135 " for user host key response"));
7138 } while (pktin || inlen > 0);
7139 s->dlgret = ssh->user_response;
7141 ssh_set_frozen(ssh, 0);
7142 if (s->dlgret == 0) {
7143 ssh_disconnect(ssh, "Aborted at host key verification", NULL,
7148 sfree(s->fingerprint);
7150 * Save this host key, to check against the one presented in
7151 * subsequent rekeys.
7153 ssh->hostkey_str = s->keystr;
7156 * In a rekey, we never present an interactive host key
7157 * verification request to the user. Instead, we simply
7158 * enforce that the key we're seeing this time is identical to
7159 * the one we saw before.
7161 if (strcmp(ssh->hostkey_str, s->keystr)) {
7162 bombout(("Host key was different in repeat key exchange"));
7167 ssh->hostkey->freekey(s->hkey);
7170 * The exchange hash from the very first key exchange is also
7171 * the session id, used in session key construction and
7174 if (!s->got_session_id) {
7175 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
7176 memcpy(ssh->v2_session_id, s->exchange_hash,
7177 sizeof(s->exchange_hash));
7178 ssh->v2_session_id_len = ssh->kex->hash->hlen;
7179 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
7180 s->got_session_id = TRUE;
7184 * Send SSH2_MSG_NEWKEYS.
7186 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
7187 ssh2_pkt_send_noqueue(ssh, s->pktout);
7188 ssh->outgoing_data_size = 0; /* start counting from here */
7191 * We've sent client NEWKEYS, so create and initialise
7192 * client-to-server session keys.
7194 if (ssh->cs_cipher_ctx)
7195 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7196 ssh->cscipher = s->cscipher_tobe;
7197 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
7199 if (ssh->cs_mac_ctx)
7200 ssh->csmac->free_context(ssh->cs_mac_ctx);
7201 ssh->csmac = s->csmac_tobe;
7202 ssh->csmac_etm = s->csmac_etm_tobe;
7203 ssh->cs_mac_ctx = ssh->csmac->make_context(ssh->cs_cipher_ctx);
7205 if (ssh->cs_comp_ctx)
7206 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7207 ssh->cscomp = s->cscomp_tobe;
7208 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
7211 * Set IVs on client-to-server keys. Here we use the exchange
7212 * hash from the _first_ key exchange.
7217 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'C',
7218 ssh->cscipher->padded_keybytes);
7219 ssh->cscipher->setkey(ssh->cs_cipher_ctx, key);
7220 smemclr(key, ssh->cscipher->padded_keybytes);
7223 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'A',
7224 ssh->cscipher->blksize);
7225 ssh->cscipher->setiv(ssh->cs_cipher_ctx, key);
7226 smemclr(key, ssh->cscipher->blksize);
7229 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'E',
7230 ssh->csmac->keylen);
7231 ssh->csmac->setkey(ssh->cs_mac_ctx, key);
7232 smemclr(key, ssh->csmac->keylen);
7236 logeventf(ssh, "Initialised %.200s client->server encryption",
7237 ssh->cscipher->text_name);
7238 logeventf(ssh, "Initialised %.200s client->server MAC algorithm%s%s",
7239 ssh->csmac->text_name,
7240 ssh->csmac_etm ? " (in ETM mode)" : "",
7241 ssh->cscipher->required_mac ? " (required by cipher)" : "");
7242 if (ssh->cscomp->text_name)
7243 logeventf(ssh, "Initialised %s compression",
7244 ssh->cscomp->text_name);
7247 * Now our end of the key exchange is complete, we can send all
7248 * our queued higher-layer packets.
7250 ssh->queueing = FALSE;
7251 ssh2_pkt_queuesend(ssh);
7254 * Expect SSH2_MSG_NEWKEYS from server.
7256 crWaitUntilV(pktin);
7257 if (pktin->type != SSH2_MSG_NEWKEYS) {
7258 bombout(("expected new-keys packet from server"));
7261 ssh->incoming_data_size = 0; /* start counting from here */
7264 * We've seen server NEWKEYS, so create and initialise
7265 * server-to-client session keys.
7267 if (ssh->sc_cipher_ctx)
7268 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7269 ssh->sccipher = s->sccipher_tobe;
7270 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
7272 if (ssh->sc_mac_ctx)
7273 ssh->scmac->free_context(ssh->sc_mac_ctx);
7274 ssh->scmac = s->scmac_tobe;
7275 ssh->scmac_etm = s->scmac_etm_tobe;
7276 ssh->sc_mac_ctx = ssh->scmac->make_context(ssh->sc_cipher_ctx);
7278 if (ssh->sc_comp_ctx)
7279 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7280 ssh->sccomp = s->sccomp_tobe;
7281 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
7284 * Set IVs on server-to-client keys. Here we use the exchange
7285 * hash from the _first_ key exchange.
7290 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'D',
7291 ssh->sccipher->padded_keybytes);
7292 ssh->sccipher->setkey(ssh->sc_cipher_ctx, key);
7293 smemclr(key, ssh->sccipher->padded_keybytes);
7296 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'B',
7297 ssh->sccipher->blksize);
7298 ssh->sccipher->setiv(ssh->sc_cipher_ctx, key);
7299 smemclr(key, ssh->sccipher->blksize);
7302 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'F',
7303 ssh->scmac->keylen);
7304 ssh->scmac->setkey(ssh->sc_mac_ctx, key);
7305 smemclr(key, ssh->scmac->keylen);
7308 logeventf(ssh, "Initialised %.200s server->client encryption",
7309 ssh->sccipher->text_name);
7310 logeventf(ssh, "Initialised %.200s server->client MAC algorithm%s%s",
7311 ssh->scmac->text_name,
7312 ssh->scmac_etm ? " (in ETM mode)" : "",
7313 ssh->sccipher->required_mac ? " (required by cipher)" : "");
7314 if (ssh->sccomp->text_name)
7315 logeventf(ssh, "Initialised %s decompression",
7316 ssh->sccomp->text_name);
7319 * Free shared secret.
7324 * Key exchange is over. Loop straight back round if we have a
7325 * deferred rekey reason.
7327 if (ssh->deferred_rekey_reason) {
7328 logevent(ssh->deferred_rekey_reason);
7330 ssh->deferred_rekey_reason = NULL;
7331 goto begin_key_exchange;
7335 * Otherwise, schedule a timer for our next rekey.
7337 ssh->kex_in_progress = FALSE;
7338 ssh->last_rekey = GETTICKCOUNT();
7339 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
7340 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7344 * Now we're encrypting. Begin returning 1 to the protocol main
7345 * function so that other things can run on top of the
7346 * transport. If we ever see a KEXINIT, we must go back to the
7349 * We _also_ go back to the start if we see pktin==NULL and
7350 * inlen negative, because this is a special signal meaning
7351 * `initiate client-driven rekey', and `in' contains a message
7352 * giving the reason for the rekey.
7354 * inlen==-1 means always initiate a rekey;
7355 * inlen==-2 means that userauth has completed successfully and
7356 * we should consider rekeying (for delayed compression).
7358 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
7359 (!pktin && inlen < 0))) {
7361 if (!ssh->protocol_initial_phase_done) {
7362 ssh->protocol_initial_phase_done = TRUE;
7364 * Allow authconn to initialise itself.
7366 do_ssh2_authconn(ssh, NULL, 0, NULL);
7371 logevent("Server initiated key re-exchange");
7375 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
7376 * delayed compression, if it's available.
7378 * draft-miller-secsh-compression-delayed-00 says that you
7379 * negotiate delayed compression in the first key exchange, and
7380 * both sides start compressing when the server has sent
7381 * USERAUTH_SUCCESS. This has a race condition -- the server
7382 * can't know when the client has seen it, and thus which incoming
7383 * packets it should treat as compressed.
7385 * Instead, we do the initial key exchange without offering the
7386 * delayed methods, but note if the server offers them; when we
7387 * get here, if a delayed method was available that was higher
7388 * on our list than what we got, we initiate a rekey in which we
7389 * _do_ list the delayed methods (and hopefully get it as a
7390 * result). Subsequent rekeys will do the same.
7392 assert(!s->userauth_succeeded); /* should only happen once */
7393 s->userauth_succeeded = TRUE;
7394 if (!s->pending_compression)
7395 /* Can't see any point rekeying. */
7396 goto wait_for_rekey; /* this is utterly horrid */
7397 /* else fall through to rekey... */
7398 s->pending_compression = FALSE;
7401 * Now we've decided to rekey.
7403 * Special case: if the server bug is set that doesn't
7404 * allow rekeying, we give a different log message and
7405 * continue waiting. (If such a server _initiates_ a rekey,
7406 * we process it anyway!)
7408 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
7409 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
7411 /* Reset the counters, so that at least this message doesn't
7412 * hit the event log _too_ often. */
7413 ssh->outgoing_data_size = 0;
7414 ssh->incoming_data_size = 0;
7415 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
7417 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7420 goto wait_for_rekey; /* this is still utterly horrid */
7422 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
7425 goto begin_key_exchange;
7431 * Add data to an SSH-2 channel output buffer.
7433 static void ssh2_add_channel_data(struct ssh_channel *c, const char *buf,
7436 bufchain_add(&c->v.v2.outbuffer, buf, len);
7440 * Attempt to send data on an SSH-2 channel.
7442 static int ssh2_try_send(struct ssh_channel *c)
7445 struct Packet *pktout;
7448 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
7451 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
7452 if ((unsigned)len > c->v.v2.remwindow)
7453 len = c->v.v2.remwindow;
7454 if ((unsigned)len > c->v.v2.remmaxpkt)
7455 len = c->v.v2.remmaxpkt;
7456 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
7457 ssh2_pkt_adduint32(pktout, c->remoteid);
7458 ssh2_pkt_addstring_start(pktout);
7459 ssh2_pkt_addstring_data(pktout, data, len);
7460 ssh2_pkt_send(ssh, pktout);
7461 bufchain_consume(&c->v.v2.outbuffer, len);
7462 c->v.v2.remwindow -= len;
7466 * After having sent as much data as we can, return the amount
7469 ret = bufchain_size(&c->v.v2.outbuffer);
7472 * And if there's no data pending but we need to send an EOF, send
7475 if (!ret && c->pending_eof)
7476 ssh_channel_try_eof(c);
7481 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
7484 if (c->closes & CLOSES_SENT_EOF)
7485 return; /* don't send on channels we've EOFed */
7486 bufsize = ssh2_try_send(c);
7489 case CHAN_MAINSESSION:
7490 /* stdin need not receive an unthrottle
7491 * notification since it will be polled */
7494 x11_unthrottle(c->u.x11.xconn);
7497 /* agent sockets are request/response and need no
7498 * buffer management */
7501 pfd_unthrottle(c->u.pfd.pf);
7507 static int ssh_is_simple(Ssh ssh)
7510 * We use the 'simple' variant of the SSH protocol if we're asked
7511 * to, except not if we're also doing connection-sharing (either
7512 * tunnelling our packets over an upstream or expecting to be
7513 * tunnelled over ourselves), since then the assumption that we
7514 * have only one channel to worry about is not true after all.
7516 return (conf_get_int(ssh->conf, CONF_ssh_simple) &&
7517 !ssh->bare_connection && !ssh->connshare);
7521 * Set up most of a new ssh_channel for SSH-2.
7523 static void ssh2_channel_init(struct ssh_channel *c)
7526 c->localid = alloc_channel_id(ssh);
7528 c->pending_eof = FALSE;
7529 c->throttling_conn = FALSE;
7530 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
7531 ssh_is_simple(ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
7532 c->v.v2.chanreq_head = NULL;
7533 c->v.v2.throttle_state = UNTHROTTLED;
7534 bufchain_init(&c->v.v2.outbuffer);
7538 * Construct the common parts of a CHANNEL_OPEN.
7540 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c,
7543 struct Packet *pktout;
7545 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7546 ssh2_pkt_addstring(pktout, type);
7547 ssh2_pkt_adduint32(pktout, c->localid);
7548 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7549 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7554 * CHANNEL_FAILURE doesn't come with any indication of what message
7555 * caused it, so we have to keep track of the outstanding
7556 * CHANNEL_REQUESTs ourselves.
7558 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
7559 cchandler_fn_t handler, void *ctx)
7561 struct outstanding_channel_request *ocr =
7562 snew(struct outstanding_channel_request);
7564 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7565 ocr->handler = handler;
7568 if (!c->v.v2.chanreq_head)
7569 c->v.v2.chanreq_head = ocr;
7571 c->v.v2.chanreq_tail->next = ocr;
7572 c->v.v2.chanreq_tail = ocr;
7576 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
7577 * NULL then a reply will be requested and the handler will be called
7578 * when it arrives. The returned packet is ready to have any
7579 * request-specific data added and be sent. Note that if a handler is
7580 * provided, it's essential that the request actually be sent.
7582 * The handler will usually be passed the response packet in pktin. If
7583 * pktin is NULL, this means that no reply will ever be forthcoming
7584 * (e.g. because the entire connection is being destroyed, or because
7585 * the server initiated channel closure before we saw the response)
7586 * and the handler should free any storage it's holding.
7588 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c,
7590 cchandler_fn_t handler, void *ctx)
7592 struct Packet *pktout;
7594 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7595 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7596 ssh2_pkt_adduint32(pktout, c->remoteid);
7597 ssh2_pkt_addstring(pktout, type);
7598 ssh2_pkt_addbool(pktout, handler != NULL);
7599 if (handler != NULL)
7600 ssh2_queue_chanreq_handler(c, handler, ctx);
7605 * Potentially enlarge the window on an SSH-2 channel.
7607 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
7609 static void ssh2_set_window(struct ssh_channel *c, int newwin)
7614 * Never send WINDOW_ADJUST for a channel that the remote side has
7615 * already sent EOF on; there's no point, since it won't be
7616 * sending any more data anyway. Ditto if _we've_ already sent
7619 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
7623 * Also, never widen the window for an X11 channel when we're
7624 * still waiting to see its initial auth and may yet hand it off
7627 if (c->type == CHAN_X11 && c->u.x11.initial)
7631 * If the remote end has a habit of ignoring maxpkt, limit the
7632 * window so that it has no choice (assuming it doesn't ignore the
7635 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
7636 newwin = OUR_V2_MAXPKT;
7639 * Only send a WINDOW_ADJUST if there's significantly more window
7640 * available than the other end thinks there is. This saves us
7641 * sending a WINDOW_ADJUST for every character in a shell session.
7643 * "Significant" is arbitrarily defined as half the window size.
7645 if (newwin / 2 >= c->v.v2.locwindow) {
7646 struct Packet *pktout;
7650 * In order to keep track of how much window the client
7651 * actually has available, we'd like it to acknowledge each
7652 * WINDOW_ADJUST. We can't do that directly, so we accompany
7653 * it with a CHANNEL_REQUEST that has to be acknowledged.
7655 * This is only necessary if we're opening the window wide.
7656 * If we're not, then throughput is being constrained by
7657 * something other than the maximum window size anyway.
7659 if (newwin == c->v.v2.locmaxwin &&
7660 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
7661 up = snew(unsigned);
7662 *up = newwin - c->v.v2.locwindow;
7663 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
7664 ssh2_handle_winadj_response, up);
7665 ssh2_pkt_send(ssh, pktout);
7667 if (c->v.v2.throttle_state != UNTHROTTLED)
7668 c->v.v2.throttle_state = UNTHROTTLING;
7670 /* Pretend the WINDOW_ADJUST was acked immediately. */
7671 c->v.v2.remlocwin = newwin;
7672 c->v.v2.throttle_state = THROTTLED;
7674 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7675 ssh2_pkt_adduint32(pktout, c->remoteid);
7676 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
7677 ssh2_pkt_send(ssh, pktout);
7678 c->v.v2.locwindow = newwin;
7683 * Find the channel associated with a message. If there's no channel,
7684 * or it's not properly open, make a noise about it and return NULL.
7686 static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
7688 unsigned localid = ssh_pkt_getuint32(pktin);
7689 struct ssh_channel *c;
7691 c = find234(ssh->channels, &localid, ssh_channelfind);
7693 (c->type != CHAN_SHARING && c->halfopen &&
7694 pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
7695 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
7696 char *buf = dupprintf("Received %s for %s channel %u",
7697 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
7699 c ? "half-open" : "nonexistent", localid);
7700 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
7707 static void ssh2_handle_winadj_response(struct ssh_channel *c,
7708 struct Packet *pktin, void *ctx)
7710 unsigned *sizep = ctx;
7713 * Winadj responses should always be failures. However, at least
7714 * one server ("boks_sshd") is known to return SUCCESS for channel
7715 * requests it's never heard of, such as "winadj@putty". Raised
7716 * with foxt.com as bug 090916-090424, but for the sake of a quiet
7717 * life, we don't worry about what kind of response we got.
7720 c->v.v2.remlocwin += *sizep;
7723 * winadj messages are only sent when the window is fully open, so
7724 * if we get an ack of one, we know any pending unthrottle is
7727 if (c->v.v2.throttle_state == UNTHROTTLING)
7728 c->v.v2.throttle_state = UNTHROTTLED;
7731 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
7733 struct ssh_channel *c = ssh2_channel_msg(ssh, pktin);
7734 struct outstanding_channel_request *ocr;
7737 if (c->type == CHAN_SHARING) {
7738 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7739 pktin->body, pktin->length);
7742 ocr = c->v.v2.chanreq_head;
7744 ssh2_msg_unexpected(ssh, pktin);
7747 ocr->handler(c, pktin, ocr->ctx);
7748 c->v.v2.chanreq_head = ocr->next;
7751 * We may now initiate channel-closing procedures, if that
7752 * CHANNEL_REQUEST was the last thing outstanding before we send
7755 ssh2_channel_check_close(c);
7758 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
7760 struct ssh_channel *c;
7761 c = ssh2_channel_msg(ssh, pktin);
7764 if (c->type == CHAN_SHARING) {
7765 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7766 pktin->body, pktin->length);
7769 if (!(c->closes & CLOSES_SENT_EOF)) {
7770 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
7771 ssh2_try_send_and_unthrottle(ssh, c);
7775 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
7779 struct ssh_channel *c;
7780 c = ssh2_channel_msg(ssh, pktin);
7783 if (c->type == CHAN_SHARING) {
7784 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7785 pktin->body, pktin->length);
7788 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
7789 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
7790 return; /* extended but not stderr */
7791 ssh_pkt_getstring(pktin, &data, &length);
7794 c->v.v2.locwindow -= length;
7795 c->v.v2.remlocwin -= length;
7797 case CHAN_MAINSESSION:
7799 from_backend(ssh->frontend, pktin->type ==
7800 SSH2_MSG_CHANNEL_EXTENDED_DATA,
7804 bufsize = x11_send(c->u.x11.xconn, data, length);
7807 bufsize = pfd_send(c->u.pfd.pf, data, length);
7810 while (length > 0) {
7811 if (c->u.a.lensofar < 4) {
7812 unsigned int l = min(4 - c->u.a.lensofar,
7814 memcpy(c->u.a.msglen + c->u.a.lensofar,
7818 c->u.a.lensofar += l;
7820 if (c->u.a.lensofar == 4) {
7822 4 + GET_32BIT(c->u.a.msglen);
7823 c->u.a.message = snewn(c->u.a.totallen,
7825 memcpy(c->u.a.message, c->u.a.msglen, 4);
7827 if (c->u.a.lensofar >= 4 && length > 0) {
7829 min(c->u.a.totallen - c->u.a.lensofar,
7831 memcpy(c->u.a.message + c->u.a.lensofar,
7835 c->u.a.lensofar += l;
7837 if (c->u.a.lensofar == c->u.a.totallen) {
7840 c->u.a.outstanding_requests++;
7841 if (agent_query(c->u.a.message,
7844 ssh_agentf_callback, c))
7845 ssh_agentf_callback(c, reply, replylen);
7846 sfree(c->u.a.message);
7847 c->u.a.message = NULL;
7848 c->u.a.lensofar = 0;
7855 * If it looks like the remote end hit the end of its window,
7856 * and we didn't want it to do that, think about using a
7859 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
7860 c->v.v2.locmaxwin < 0x40000000)
7861 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
7863 * If we are not buffering too much data,
7864 * enlarge the window again at the remote side.
7865 * If we are buffering too much, we may still
7866 * need to adjust the window if the server's
7869 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
7870 c->v.v2.locmaxwin - bufsize : 0);
7872 * If we're either buffering way too much data, or if we're
7873 * buffering anything at all and we're in "simple" mode,
7874 * throttle the whole channel.
7876 if ((bufsize > c->v.v2.locmaxwin || (ssh_is_simple(ssh) && bufsize>0))
7877 && !c->throttling_conn) {
7878 c->throttling_conn = 1;
7879 ssh_throttle_conn(ssh, +1);
7884 static void ssh_check_termination(Ssh ssh)
7886 if (ssh->version == 2 &&
7887 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
7888 (ssh->channels && count234(ssh->channels) == 0) &&
7889 !(ssh->connshare && share_ndownstreams(ssh->connshare) > 0)) {
7891 * We used to send SSH_MSG_DISCONNECT here, because I'd
7892 * believed that _every_ conforming SSH-2 connection had to
7893 * end with a disconnect being sent by at least one side;
7894 * apparently I was wrong and it's perfectly OK to
7895 * unceremoniously slam the connection shut when you're done,
7896 * and indeed OpenSSH feels this is more polite than sending a
7897 * DISCONNECT. So now we don't.
7899 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
7903 void ssh_sharing_downstream_connected(Ssh ssh, unsigned id,
7904 const char *peerinfo)
7907 logeventf(ssh, "Connection sharing downstream #%u connected from %s",
7910 logeventf(ssh, "Connection sharing downstream #%u connected", id);
7913 void ssh_sharing_downstream_disconnected(Ssh ssh, unsigned id)
7915 logeventf(ssh, "Connection sharing downstream #%u disconnected", id);
7916 ssh_check_termination(ssh);
7919 void ssh_sharing_logf(Ssh ssh, unsigned id, const char *logfmt, ...)
7924 va_start(ap, logfmt);
7925 buf = dupvprintf(logfmt, ap);
7928 logeventf(ssh, "Connection sharing downstream #%u: %s", id, buf);
7930 logeventf(ssh, "Connection sharing: %s", buf);
7934 static void ssh_channel_destroy(struct ssh_channel *c)
7939 case CHAN_MAINSESSION:
7940 ssh->mainchan = NULL;
7941 update_specials_menu(ssh->frontend);
7944 if (c->u.x11.xconn != NULL)
7945 x11_close(c->u.x11.xconn);
7946 logevent("Forwarded X11 connection terminated");
7949 sfree(c->u.a.message);
7952 if (c->u.pfd.pf != NULL)
7953 pfd_close(c->u.pfd.pf);
7954 logevent("Forwarded port closed");
7958 del234(ssh->channels, c);
7959 if (ssh->version == 2) {
7960 bufchain_clear(&c->v.v2.outbuffer);
7961 assert(c->v.v2.chanreq_head == NULL);
7966 * If that was the last channel left open, we might need to
7969 ssh_check_termination(ssh);
7972 static void ssh2_channel_check_close(struct ssh_channel *c)
7975 struct Packet *pktout;
7979 * If we've sent out our own CHANNEL_OPEN but not yet seen
7980 * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
7981 * it's too early to be sending close messages of any kind.
7986 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
7987 c->type == CHAN_ZOMBIE) &&
7988 !c->v.v2.chanreq_head &&
7989 !(c->closes & CLOSES_SENT_CLOSE)) {
7991 * We have both sent and received EOF (or the channel is a
7992 * zombie), and we have no outstanding channel requests, which
7993 * means the channel is in final wind-up. But we haven't sent
7994 * CLOSE, so let's do so now.
7996 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
7997 ssh2_pkt_adduint32(pktout, c->remoteid);
7998 ssh2_pkt_send(ssh, pktout);
7999 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
8002 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
8003 assert(c->v.v2.chanreq_head == NULL);
8005 * We have both sent and received CLOSE, which means we're
8006 * completely done with the channel.
8008 ssh_channel_destroy(c);
8012 static void ssh2_channel_got_eof(struct ssh_channel *c)
8014 if (c->closes & CLOSES_RCVD_EOF)
8015 return; /* already seen EOF */
8016 c->closes |= CLOSES_RCVD_EOF;
8018 if (c->type == CHAN_X11) {
8019 x11_send_eof(c->u.x11.xconn);
8020 } else if (c->type == CHAN_AGENT) {
8021 if (c->u.a.outstanding_requests == 0) {
8022 /* Manufacture an outgoing EOF in response to the incoming one. */
8023 sshfwd_write_eof(c);
8025 } else if (c->type == CHAN_SOCKDATA) {
8026 pfd_send_eof(c->u.pfd.pf);
8027 } else if (c->type == CHAN_MAINSESSION) {
8030 if (!ssh->sent_console_eof &&
8031 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
8033 * Either from_backend_eof told us that the front end
8034 * wants us to close the outgoing side of the connection
8035 * as soon as we see EOF from the far end, or else we've
8036 * unilaterally decided to do that because we've allocated
8037 * a remote pty and hence EOF isn't a particularly
8038 * meaningful concept.
8040 sshfwd_write_eof(c);
8042 ssh->sent_console_eof = TRUE;
8045 ssh2_channel_check_close(c);
8048 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
8050 struct ssh_channel *c;
8052 c = ssh2_channel_msg(ssh, pktin);
8055 if (c->type == CHAN_SHARING) {
8056 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8057 pktin->body, pktin->length);
8060 ssh2_channel_got_eof(c);
8063 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
8065 struct ssh_channel *c;
8067 c = ssh2_channel_msg(ssh, pktin);
8070 if (c->type == CHAN_SHARING) {
8071 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8072 pktin->body, pktin->length);
8077 * When we receive CLOSE on a channel, we assume it comes with an
8078 * implied EOF if we haven't seen EOF yet.
8080 ssh2_channel_got_eof(c);
8082 if (!(ssh->remote_bugs & BUG_SENDS_LATE_REQUEST_REPLY)) {
8084 * It also means we stop expecting to see replies to any
8085 * outstanding channel requests, so clean those up too.
8086 * (ssh_chanreq_init will enforce by assertion that we don't
8087 * subsequently put anything back on this list.)
8089 while (c->v.v2.chanreq_head) {
8090 struct outstanding_channel_request *ocr = c->v.v2.chanreq_head;
8091 ocr->handler(c, NULL, ocr->ctx);
8092 c->v.v2.chanreq_head = ocr->next;
8098 * And we also send an outgoing EOF, if we haven't already, on the
8099 * assumption that CLOSE is a pretty forceful announcement that
8100 * the remote side is doing away with the entire channel. (If it
8101 * had wanted to send us EOF and continue receiving data from us,
8102 * it would have just sent CHANNEL_EOF.)
8104 if (!(c->closes & CLOSES_SENT_EOF)) {
8106 * Make sure we don't read any more from whatever our local
8107 * data source is for this channel.
8110 case CHAN_MAINSESSION:
8111 ssh->send_ok = 0; /* stop trying to read from stdin */
8114 x11_override_throttle(c->u.x11.xconn, 1);
8117 pfd_override_throttle(c->u.pfd.pf, 1);
8122 * Abandon any buffered data we still wanted to send to this
8123 * channel. Receiving a CHANNEL_CLOSE is an indication that
8124 * the server really wants to get on and _destroy_ this
8125 * channel, and it isn't going to send us any further
8126 * WINDOW_ADJUSTs to permit us to send pending stuff.
8128 bufchain_clear(&c->v.v2.outbuffer);
8131 * Send outgoing EOF.
8133 sshfwd_write_eof(c);
8137 * Now process the actual close.
8139 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
8140 c->closes |= CLOSES_RCVD_CLOSE;
8141 ssh2_channel_check_close(c);
8145 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
8147 struct ssh_channel *c;
8149 c = ssh2_channel_msg(ssh, pktin);
8152 if (c->type == CHAN_SHARING) {
8153 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8154 pktin->body, pktin->length);
8157 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
8158 c->remoteid = ssh_pkt_getuint32(pktin);
8159 c->halfopen = FALSE;
8160 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8161 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
8163 if (c->type == CHAN_SOCKDATA_DORMANT) {
8164 c->type = CHAN_SOCKDATA;
8166 pfd_confirm(c->u.pfd.pf);
8167 } else if (c->type == CHAN_ZOMBIE) {
8169 * This case can occur if a local socket error occurred
8170 * between us sending out CHANNEL_OPEN and receiving
8171 * OPEN_CONFIRMATION. In this case, all we can do is
8172 * immediately initiate close proceedings now that we know the
8173 * server's id to put in the close message.
8175 ssh2_channel_check_close(c);
8178 * We never expect to receive OPEN_CONFIRMATION for any
8179 * *other* channel type (since only local-to-remote port
8180 * forwardings cause us to send CHANNEL_OPEN after the main
8181 * channel is live - all other auxiliary channel types are
8182 * initiated from the server end). It's safe to enforce this
8183 * by assertion rather than by ssh_disconnect, because the
8184 * real point is that we never constructed a half-open channel
8185 * structure in the first place with any type other than the
8188 assert(!"Funny channel type in ssh2_msg_channel_open_confirmation");
8192 ssh_channel_try_eof(c); /* in case we had a pending EOF */
8195 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
8197 static const char *const reasons[] = {
8198 "<unknown reason code>",
8199 "Administratively prohibited",
8201 "Unknown channel type",
8202 "Resource shortage",
8204 unsigned reason_code;
8205 char *reason_string;
8207 struct ssh_channel *c;
8209 c = ssh2_channel_msg(ssh, pktin);
8212 if (c->type == CHAN_SHARING) {
8213 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8214 pktin->body, pktin->length);
8217 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
8219 if (c->type == CHAN_SOCKDATA_DORMANT) {
8220 reason_code = ssh_pkt_getuint32(pktin);
8221 if (reason_code >= lenof(reasons))
8222 reason_code = 0; /* ensure reasons[reason_code] in range */
8223 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
8224 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
8225 reasons[reason_code], reason_length, reason_string);
8227 pfd_close(c->u.pfd.pf);
8228 } else if (c->type == CHAN_ZOMBIE) {
8230 * This case can occur if a local socket error occurred
8231 * between us sending out CHANNEL_OPEN and receiving
8232 * OPEN_FAILURE. In this case, we need do nothing except allow
8233 * the code below to throw the half-open channel away.
8237 * We never expect to receive OPEN_FAILURE for any *other*
8238 * channel type (since only local-to-remote port forwardings
8239 * cause us to send CHANNEL_OPEN after the main channel is
8240 * live - all other auxiliary channel types are initiated from
8241 * the server end). It's safe to enforce this by assertion
8242 * rather than by ssh_disconnect, because the real point is
8243 * that we never constructed a half-open channel structure in
8244 * the first place with any type other than the above.
8246 assert(!"Funny channel type in ssh2_msg_channel_open_failure");
8249 del234(ssh->channels, c);
8253 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
8256 int typelen, want_reply;
8257 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
8258 struct ssh_channel *c;
8259 struct Packet *pktout;
8261 c = ssh2_channel_msg(ssh, pktin);
8264 if (c->type == CHAN_SHARING) {
8265 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8266 pktin->body, pktin->length);
8269 ssh_pkt_getstring(pktin, &type, &typelen);
8270 want_reply = ssh2_pkt_getbool(pktin);
8272 if (c->closes & CLOSES_SENT_CLOSE) {
8274 * We don't reply to channel requests after we've sent
8275 * CHANNEL_CLOSE for the channel, because our reply might
8276 * cross in the network with the other side's CHANNEL_CLOSE
8277 * and arrive after they have wound the channel up completely.
8283 * Having got the channel number, we now look at
8284 * the request type string to see if it's something
8287 if (c == ssh->mainchan) {
8289 * We recognise "exit-status" and "exit-signal" on
8290 * the primary channel.
8292 if (typelen == 11 &&
8293 !memcmp(type, "exit-status", 11)) {
8295 ssh->exitcode = ssh_pkt_getuint32(pktin);
8296 logeventf(ssh, "Server sent command exit status %d",
8298 reply = SSH2_MSG_CHANNEL_SUCCESS;
8300 } else if (typelen == 11 &&
8301 !memcmp(type, "exit-signal", 11)) {
8303 int is_plausible = TRUE, is_int = FALSE;
8304 char *fmt_sig = NULL, *fmt_msg = NULL;
8306 int msglen = 0, core = FALSE;
8307 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
8308 * provide an `int' for the signal, despite its
8309 * having been a `string' in the drafts of RFC 4254 since at
8310 * least 2001. (Fixed in session.c 1.147.) Try to
8311 * infer which we can safely parse it as. */
8313 unsigned char *p = pktin->body +
8315 long len = pktin->length - pktin->savedpos;
8316 unsigned long num = GET_32BIT(p); /* what is it? */
8317 /* If it's 0, it hardly matters; assume string */
8321 int maybe_int = FALSE, maybe_str = FALSE;
8322 #define CHECK_HYPOTHESIS(offset, result) \
8325 int q = toint(offset); \
8326 if (q >= 0 && q+4 <= len) { \
8327 q = toint(q + 4 + GET_32BIT(p+q)); \
8328 if (q >= 0 && q+4 <= len && \
8329 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
8334 CHECK_HYPOTHESIS(4+1, maybe_int);
8335 CHECK_HYPOTHESIS(4+num+1, maybe_str);
8336 #undef CHECK_HYPOTHESIS
8337 if (maybe_int && !maybe_str)
8339 else if (!maybe_int && maybe_str)
8342 /* Crikey. Either or neither. Panic. */
8343 is_plausible = FALSE;
8346 ssh->exitcode = 128; /* means `unknown signal' */
8349 /* Old non-standard OpenSSH. */
8350 int signum = ssh_pkt_getuint32(pktin);
8351 fmt_sig = dupprintf(" %d", signum);
8352 ssh->exitcode = 128 + signum;
8354 /* As per RFC 4254. */
8357 ssh_pkt_getstring(pktin, &sig, &siglen);
8358 /* Signal name isn't supposed to be blank, but
8359 * let's cope gracefully if it is. */
8361 fmt_sig = dupprintf(" \"%.*s\"",
8366 * Really hideous method of translating the
8367 * signal description back into a locally
8368 * meaningful number.
8373 #define TRANSLATE_SIGNAL(s) \
8374 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
8375 ssh->exitcode = 128 + SIG ## s
8377 TRANSLATE_SIGNAL(ABRT);
8380 TRANSLATE_SIGNAL(ALRM);
8383 TRANSLATE_SIGNAL(FPE);
8386 TRANSLATE_SIGNAL(HUP);
8389 TRANSLATE_SIGNAL(ILL);
8392 TRANSLATE_SIGNAL(INT);
8395 TRANSLATE_SIGNAL(KILL);
8398 TRANSLATE_SIGNAL(PIPE);
8401 TRANSLATE_SIGNAL(QUIT);
8404 TRANSLATE_SIGNAL(SEGV);
8407 TRANSLATE_SIGNAL(TERM);
8410 TRANSLATE_SIGNAL(USR1);
8413 TRANSLATE_SIGNAL(USR2);
8415 #undef TRANSLATE_SIGNAL
8417 ssh->exitcode = 128;
8419 core = ssh2_pkt_getbool(pktin);
8420 ssh_pkt_getstring(pktin, &msg, &msglen);
8422 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
8424 /* ignore lang tag */
8425 } /* else don't attempt to parse */
8426 logeventf(ssh, "Server exited on signal%s%s%s",
8427 fmt_sig ? fmt_sig : "",
8428 core ? " (core dumped)" : "",
8429 fmt_msg ? fmt_msg : "");
8432 reply = SSH2_MSG_CHANNEL_SUCCESS;
8437 * This is a channel request we don't know
8438 * about, so we now either ignore the request
8439 * or respond with CHANNEL_FAILURE, depending
8442 reply = SSH2_MSG_CHANNEL_FAILURE;
8445 pktout = ssh2_pkt_init(reply);
8446 ssh2_pkt_adduint32(pktout, c->remoteid);
8447 ssh2_pkt_send(ssh, pktout);
8451 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
8454 int typelen, want_reply;
8455 struct Packet *pktout;
8457 ssh_pkt_getstring(pktin, &type, &typelen);
8458 want_reply = ssh2_pkt_getbool(pktin);
8461 * We currently don't support any global requests
8462 * at all, so we either ignore the request or
8463 * respond with REQUEST_FAILURE, depending on
8467 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
8468 ssh2_pkt_send(ssh, pktout);
8472 struct X11FakeAuth *ssh_sharing_add_x11_display(Ssh ssh, int authtype,
8476 struct X11FakeAuth *auth;
8479 * Make up a new set of fake X11 auth data, and add it to the tree
8480 * of currently valid ones with an indication of the sharing
8481 * context that it's relevant to.
8483 auth = x11_invent_fake_auth(ssh->x11authtree, authtype);
8484 auth->share_cs = share_cs;
8485 auth->share_chan = share_chan;
8490 void ssh_sharing_remove_x11_display(Ssh ssh, struct X11FakeAuth *auth)
8492 del234(ssh->x11authtree, auth);
8493 x11_free_fake_auth(auth);
8496 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
8503 const char *error = NULL;
8504 struct ssh_channel *c;
8505 unsigned remid, winsize, pktsize;
8506 unsigned our_winsize_override = 0;
8507 struct Packet *pktout;
8509 ssh_pkt_getstring(pktin, &type, &typelen);
8510 c = snew(struct ssh_channel);
8513 remid = ssh_pkt_getuint32(pktin);
8514 winsize = ssh_pkt_getuint32(pktin);
8515 pktsize = ssh_pkt_getuint32(pktin);
8517 if (typelen == 3 && !memcmp(type, "x11", 3)) {
8520 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8521 addrstr = snewn(peeraddrlen+1, char);
8522 memcpy(addrstr, peeraddr, peeraddrlen);
8523 addrstr[peeraddrlen] = '\0';
8524 peerport = ssh_pkt_getuint32(pktin);
8526 logeventf(ssh, "Received X11 connect request from %s:%d",
8529 if (!ssh->X11_fwd_enabled && !ssh->connshare)
8530 error = "X11 forwarding is not enabled";
8532 c->u.x11.xconn = x11_init(ssh->x11authtree, c,
8535 c->u.x11.initial = TRUE;
8538 * If we are a connection-sharing upstream, then we should
8539 * initially present a very small window, adequate to take
8540 * the X11 initial authorisation packet but not much more.
8541 * Downstream will then present us a larger window (by
8542 * fiat of the connection-sharing protocol) and we can
8543 * guarantee to send a positive-valued WINDOW_ADJUST.
8546 our_winsize_override = 128;
8548 logevent("Opened X11 forward channel");
8552 } else if (typelen == 15 &&
8553 !memcmp(type, "forwarded-tcpip", 15)) {
8554 struct ssh_rportfwd pf, *realpf;
8557 ssh_pkt_getstring(pktin, &shost, &shostlen);/* skip address */
8558 pf.shost = dupprintf("%.*s", shostlen, shost);
8559 pf.sport = ssh_pkt_getuint32(pktin);
8560 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8561 peerport = ssh_pkt_getuint32(pktin);
8562 realpf = find234(ssh->rportfwds, &pf, NULL);
8563 logeventf(ssh, "Received remote port %s:%d open request "
8564 "from %s:%d", pf.shost, pf.sport, peeraddr, peerport);
8567 if (realpf == NULL) {
8568 error = "Remote port is not recognised";
8572 if (realpf->share_ctx) {
8574 * This port forwarding is on behalf of a
8575 * connection-sharing downstream, so abandon our own
8576 * channel-open procedure and just pass the message on
8579 share_got_pkt_from_server(realpf->share_ctx, pktin->type,
8580 pktin->body, pktin->length);
8585 err = pfd_connect(&c->u.pfd.pf, realpf->dhost, realpf->dport,
8586 c, ssh->conf, realpf->pfrec->addressfamily);
8587 logeventf(ssh, "Attempting to forward remote port to "
8588 "%s:%d", realpf->dhost, realpf->dport);
8590 logeventf(ssh, "Port open failed: %s", err);
8592 error = "Port open failed";
8594 logevent("Forwarded port opened successfully");
8595 c->type = CHAN_SOCKDATA;
8598 } else if (typelen == 22 &&
8599 !memcmp(type, "auth-agent@openssh.com", 22)) {
8600 if (!ssh->agentfwd_enabled)
8601 error = "Agent forwarding is not enabled";
8603 c->type = CHAN_AGENT; /* identify channel type */
8604 c->u.a.lensofar = 0;
8605 c->u.a.message = NULL;
8606 c->u.a.outstanding_requests = 0;
8609 error = "Unsupported channel type requested";
8612 c->remoteid = remid;
8613 c->halfopen = FALSE;
8615 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
8616 ssh2_pkt_adduint32(pktout, c->remoteid);
8617 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
8618 ssh2_pkt_addstring(pktout, error);
8619 ssh2_pkt_addstring(pktout, "en"); /* language tag */
8620 ssh2_pkt_send(ssh, pktout);
8621 logeventf(ssh, "Rejected channel open: %s", error);
8624 ssh2_channel_init(c);
8625 c->v.v2.remwindow = winsize;
8626 c->v.v2.remmaxpkt = pktsize;
8627 if (our_winsize_override) {
8628 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
8629 our_winsize_override;
8631 add234(ssh->channels, c);
8632 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
8633 ssh2_pkt_adduint32(pktout, c->remoteid);
8634 ssh2_pkt_adduint32(pktout, c->localid);
8635 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
8636 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8637 ssh2_pkt_send(ssh, pktout);
8641 void sshfwd_x11_sharing_handover(struct ssh_channel *c,
8642 void *share_cs, void *share_chan,
8643 const char *peer_addr, int peer_port,
8644 int endian, int protomajor, int protominor,
8645 const void *initial_data, int initial_len)
8648 * This function is called when we've just discovered that an X
8649 * forwarding channel on which we'd been handling the initial auth
8650 * ourselves turns out to be destined for a connection-sharing
8651 * downstream. So we turn the channel into a CHAN_SHARING, meaning
8652 * that we completely stop tracking windows and buffering data and
8653 * just pass more or less unmodified SSH messages back and forth.
8655 c->type = CHAN_SHARING;
8656 c->u.sharing.ctx = share_cs;
8657 share_setup_x11_channel(share_cs, share_chan,
8658 c->localid, c->remoteid, c->v.v2.remwindow,
8659 c->v.v2.remmaxpkt, c->v.v2.locwindow,
8660 peer_addr, peer_port, endian,
8661 protomajor, protominor,
8662 initial_data, initial_len);
8665 void sshfwd_x11_is_local(struct ssh_channel *c)
8668 * This function is called when we've just discovered that an X
8669 * forwarding channel is _not_ destined for a connection-sharing
8670 * downstream but we're going to handle it ourselves. We stop
8671 * presenting a cautiously small window and go into ordinary data
8674 c->u.x11.initial = FALSE;
8675 ssh2_set_window(c, ssh_is_simple(c->ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE);
8679 * Buffer banner messages for later display at some convenient point,
8680 * if we're going to display them.
8682 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
8684 /* Arbitrary limit to prevent unbounded inflation of buffer */
8685 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
8686 bufchain_size(&ssh->banner) <= 131072) {
8687 char *banner = NULL;
8689 ssh_pkt_getstring(pktin, &banner, &size);
8691 bufchain_add(&ssh->banner, banner, size);
8695 /* Helper function to deal with sending tty modes for "pty-req" */
8696 static void ssh2_send_ttymode(void *data, char *mode, char *val)
8698 struct Packet *pktout = (struct Packet *)data;
8700 unsigned int arg = 0;
8701 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
8702 if (i == lenof(ssh_ttymodes)) return;
8703 switch (ssh_ttymodes[i].type) {
8705 arg = ssh_tty_parse_specchar(val);
8708 arg = ssh_tty_parse_boolean(val);
8711 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
8712 ssh2_pkt_adduint32(pktout, arg);
8715 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
8718 struct ssh2_setup_x11_state {
8722 struct Packet *pktout;
8723 crStateP(ssh2_setup_x11_state, ctx);
8727 logevent("Requesting X11 forwarding");
8728 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
8730 ssh2_pkt_addbool(pktout, 0); /* many connections */
8731 ssh2_pkt_addstring(pktout, ssh->x11auth->protoname);
8732 ssh2_pkt_addstring(pktout, ssh->x11auth->datastring);
8733 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
8734 ssh2_pkt_send(ssh, pktout);
8736 /* Wait to be called back with either a response packet, or NULL
8737 * meaning clean up and free our data */
8741 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8742 logevent("X11 forwarding enabled");
8743 ssh->X11_fwd_enabled = TRUE;
8745 logevent("X11 forwarding refused");
8751 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
8754 struct ssh2_setup_agent_state {
8758 struct Packet *pktout;
8759 crStateP(ssh2_setup_agent_state, ctx);
8763 logevent("Requesting OpenSSH-style agent forwarding");
8764 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
8765 ssh2_setup_agent, s);
8766 ssh2_pkt_send(ssh, pktout);
8768 /* Wait to be called back with either a response packet, or NULL
8769 * meaning clean up and free our data */
8773 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8774 logevent("Agent forwarding enabled");
8775 ssh->agentfwd_enabled = TRUE;
8777 logevent("Agent forwarding refused");
8783 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
8786 struct ssh2_setup_pty_state {
8790 struct Packet *pktout;
8791 crStateP(ssh2_setup_pty_state, ctx);
8795 /* Unpick the terminal-speed string. */
8796 /* XXX perhaps we should allow no speeds to be sent. */
8797 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
8798 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
8799 /* Build the pty request. */
8800 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
8802 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
8803 ssh2_pkt_adduint32(pktout, ssh->term_width);
8804 ssh2_pkt_adduint32(pktout, ssh->term_height);
8805 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
8806 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
8807 ssh2_pkt_addstring_start(pktout);
8808 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
8809 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
8810 ssh2_pkt_adduint32(pktout, ssh->ispeed);
8811 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
8812 ssh2_pkt_adduint32(pktout, ssh->ospeed);
8813 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
8814 ssh2_pkt_send(ssh, pktout);
8815 ssh->state = SSH_STATE_INTERMED;
8817 /* Wait to be called back with either a response packet, or NULL
8818 * meaning clean up and free our data */
8822 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8823 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
8824 ssh->ospeed, ssh->ispeed);
8825 ssh->got_pty = TRUE;
8827 c_write_str(ssh, "Server refused to allocate pty\r\n");
8828 ssh->editing = ssh->echoing = 1;
8835 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
8838 struct ssh2_setup_env_state {
8840 int num_env, env_left, env_ok;
8843 struct Packet *pktout;
8844 crStateP(ssh2_setup_env_state, ctx);
8849 * Send environment variables.
8851 * Simplest thing here is to send all the requests at once, and
8852 * then wait for a whole bunch of successes or failures.
8858 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
8860 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
8861 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
8862 ssh2_pkt_addstring(pktout, key);
8863 ssh2_pkt_addstring(pktout, val);
8864 ssh2_pkt_send(ssh, pktout);
8869 logeventf(ssh, "Sent %d environment variables", s->num_env);
8874 s->env_left = s->num_env;
8876 while (s->env_left > 0) {
8877 /* Wait to be called back with either a response packet,
8878 * or NULL meaning clean up and free our data */
8880 if (!pktin) goto out;
8881 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
8886 if (s->env_ok == s->num_env) {
8887 logevent("All environment variables successfully set");
8888 } else if (s->env_ok == 0) {
8889 logevent("All environment variables refused");
8890 c_write_str(ssh, "Server refused to set environment variables\r\n");
8892 logeventf(ssh, "%d environment variables refused",
8893 s->num_env - s->env_ok);
8894 c_write_str(ssh, "Server refused to set all environment variables\r\n");
8902 * Handle the SSH-2 userauth and connection layers.
8904 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
8906 do_ssh2_authconn(ssh, NULL, 0, pktin);
8909 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
8913 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
8916 static void do_ssh2_authconn(Ssh ssh, const unsigned char *in, int inlen,
8917 struct Packet *pktin)
8919 struct do_ssh2_authconn_state {
8923 AUTH_TYPE_PUBLICKEY,
8924 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
8925 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
8927 AUTH_TYPE_GSSAPI, /* always QUIET */
8928 AUTH_TYPE_KEYBOARD_INTERACTIVE,
8929 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
8931 int done_service_req;
8932 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
8933 int tried_pubkey_config, done_agent;
8938 int kbd_inter_refused;
8939 int we_are_in, userauth_success;
8940 prompts_t *cur_prompt;
8945 void *publickey_blob;
8946 int publickey_bloblen;
8947 int privatekey_available, privatekey_encrypted;
8948 char *publickey_algorithm;
8949 char *publickey_comment;
8950 unsigned char agent_request[5], *agent_response, *agentp;
8951 int agent_responselen;
8952 unsigned char *pkblob_in_agent;
8954 char *pkblob, *alg, *commentp;
8955 int pklen, alglen, commentlen;
8956 int siglen, retlen, len;
8957 char *q, *agentreq, *ret;
8959 struct Packet *pktout;
8962 struct ssh_gss_library *gsslib;
8963 Ssh_gss_ctx gss_ctx;
8964 Ssh_gss_buf gss_buf;
8965 Ssh_gss_buf gss_rcvtok, gss_sndtok;
8966 Ssh_gss_name gss_srv_name;
8967 Ssh_gss_stat gss_stat;
8970 crState(do_ssh2_authconn_state);
8974 /* Register as a handler for all the messages this coroutine handles. */
8975 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
8976 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
8977 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
8978 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
8979 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
8980 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
8981 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
8982 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
8983 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
8984 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
8985 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
8986 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
8987 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
8988 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
8989 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
8990 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
8991 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
8992 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
8993 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
8994 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
8996 s->done_service_req = FALSE;
8997 s->we_are_in = s->userauth_success = FALSE;
8998 s->agent_response = NULL;
9000 s->tried_gssapi = FALSE;
9003 if (!ssh->bare_connection) {
9004 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
9006 * Request userauth protocol, and await a response to it.
9008 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
9009 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
9010 ssh2_pkt_send(ssh, s->pktout);
9011 crWaitUntilV(pktin);
9012 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
9013 s->done_service_req = TRUE;
9015 if (!s->done_service_req) {
9017 * Request connection protocol directly, without authentication.
9019 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
9020 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9021 ssh2_pkt_send(ssh, s->pktout);
9022 crWaitUntilV(pktin);
9023 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
9024 s->we_are_in = TRUE; /* no auth required */
9026 bombout(("Server refused service request"));
9031 s->we_are_in = TRUE;
9034 /* Arrange to be able to deal with any BANNERs that come in.
9035 * (We do this now as packets may come in during the next bit.) */
9036 bufchain_init(&ssh->banner);
9037 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
9038 ssh2_msg_userauth_banner;
9041 * Misc one-time setup for authentication.
9043 s->publickey_blob = NULL;
9044 if (!s->we_are_in) {
9047 * Load the public half of any configured public key file
9050 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9051 if (!filename_is_null(s->keyfile)) {
9053 logeventf(ssh, "Reading key file \"%.150s\"",
9054 filename_to_str(s->keyfile));
9055 keytype = key_type(s->keyfile);
9056 if (keytype == SSH_KEYTYPE_SSH2 ||
9057 keytype == SSH_KEYTYPE_SSH2_PUBLIC_RFC4716 ||
9058 keytype == SSH_KEYTYPE_SSH2_PUBLIC_OPENSSH) {
9061 ssh2_userkey_loadpub(s->keyfile,
9062 &s->publickey_algorithm,
9063 &s->publickey_bloblen,
9064 &s->publickey_comment, &error);
9065 if (s->publickey_blob) {
9066 s->privatekey_available = (keytype == SSH_KEYTYPE_SSH2);
9067 if (!s->privatekey_available)
9068 logeventf(ssh, "Key file contains public key only");
9069 s->privatekey_encrypted =
9070 ssh2_userkey_encrypted(s->keyfile, NULL);
9073 logeventf(ssh, "Unable to load key (%s)",
9075 msgbuf = dupprintf("Unable to load key file "
9076 "\"%.150s\" (%s)\r\n",
9077 filename_to_str(s->keyfile),
9079 c_write_str(ssh, msgbuf);
9084 logeventf(ssh, "Unable to use this key file (%s)",
9085 key_type_to_str(keytype));
9086 msgbuf = dupprintf("Unable to use key file \"%.150s\""
9088 filename_to_str(s->keyfile),
9089 key_type_to_str(keytype));
9090 c_write_str(ssh, msgbuf);
9092 s->publickey_blob = NULL;
9097 * Find out about any keys Pageant has (but if there's a
9098 * public key configured, filter out all others).
9101 s->agent_response = NULL;
9102 s->pkblob_in_agent = NULL;
9103 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
9107 logevent("Pageant is running. Requesting keys.");
9109 /* Request the keys held by the agent. */
9110 PUT_32BIT(s->agent_request, 1);
9111 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
9112 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
9113 ssh_agent_callback, ssh)) {
9117 bombout(("Unexpected data from server while"
9118 " waiting for agent response"));
9121 } while (pktin || inlen > 0);
9122 r = ssh->agent_response;
9123 s->agent_responselen = ssh->agent_response_len;
9125 s->agent_response = (unsigned char *) r;
9126 if (s->agent_response && s->agent_responselen >= 5 &&
9127 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
9130 p = s->agent_response + 5;
9131 s->nkeys = toint(GET_32BIT(p));
9134 * Vet the Pageant response to ensure that the key
9135 * count and blob lengths make sense.
9138 logeventf(ssh, "Pageant response contained a negative"
9139 " key count %d", s->nkeys);
9141 goto done_agent_query;
9143 unsigned char *q = p + 4;
9144 int lenleft = s->agent_responselen - 5 - 4;
9146 for (keyi = 0; keyi < s->nkeys; keyi++) {
9147 int bloblen, commentlen;
9149 logeventf(ssh, "Pageant response was truncated");
9151 goto done_agent_query;
9153 bloblen = toint(GET_32BIT(q));
9154 if (bloblen < 0 || bloblen > lenleft) {
9155 logeventf(ssh, "Pageant response was truncated");
9157 goto done_agent_query;
9159 lenleft -= 4 + bloblen;
9161 commentlen = toint(GET_32BIT(q));
9162 if (commentlen < 0 || commentlen > lenleft) {
9163 logeventf(ssh, "Pageant response was truncated");
9165 goto done_agent_query;
9167 lenleft -= 4 + commentlen;
9168 q += 4 + commentlen;
9173 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
9174 if (s->publickey_blob) {
9175 /* See if configured key is in agent. */
9176 for (keyi = 0; keyi < s->nkeys; keyi++) {
9177 s->pklen = toint(GET_32BIT(p));
9178 if (s->pklen == s->publickey_bloblen &&
9179 !memcmp(p+4, s->publickey_blob,
9180 s->publickey_bloblen)) {
9181 logeventf(ssh, "Pageant key #%d matches "
9182 "configured key file", keyi);
9184 s->pkblob_in_agent = p;
9188 p += toint(GET_32BIT(p)) + 4; /* comment */
9190 if (!s->pkblob_in_agent) {
9191 logevent("Configured key file not in Pageant");
9196 logevent("Failed to get reply from Pageant");
9204 * We repeat this whole loop, including the username prompt,
9205 * until we manage a successful authentication. If the user
9206 * types the wrong _password_, they can be sent back to the
9207 * beginning to try another username, if this is configured on.
9208 * (If they specify a username in the config, they are never
9209 * asked, even if they do give a wrong password.)
9211 * I think this best serves the needs of
9213 * - the people who have no configuration, no keys, and just
9214 * want to try repeated (username,password) pairs until they
9215 * type both correctly
9217 * - people who have keys and configuration but occasionally
9218 * need to fall back to passwords
9220 * - people with a key held in Pageant, who might not have
9221 * logged in to a particular machine before; so they want to
9222 * type a username, and then _either_ their key will be
9223 * accepted, _or_ they will type a password. If they mistype
9224 * the username they will want to be able to get back and
9227 s->got_username = FALSE;
9228 while (!s->we_are_in) {
9232 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
9234 * We got a username last time round this loop, and
9235 * with change_username turned off we don't try to get
9238 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
9239 int ret; /* need not be kept over crReturn */
9240 s->cur_prompt = new_prompts(ssh->frontend);
9241 s->cur_prompt->to_server = TRUE;
9242 s->cur_prompt->name = dupstr("SSH login name");
9243 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
9244 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9247 crWaitUntilV(!pktin);
9248 ret = get_userpass_input(s->cur_prompt, in, inlen);
9253 * get_userpass_input() failed to get a username.
9256 free_prompts(s->cur_prompt);
9257 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
9260 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
9261 free_prompts(s->cur_prompt);
9264 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
9265 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
9266 c_write_str(ssh, stuff);
9270 s->got_username = TRUE;
9273 * Send an authentication request using method "none": (a)
9274 * just in case it succeeds, and (b) so that we know what
9275 * authentication methods we can usefully try next.
9277 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9279 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9280 ssh2_pkt_addstring(s->pktout, ssh->username);
9281 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
9282 ssh2_pkt_addstring(s->pktout, "none"); /* method */
9283 ssh2_pkt_send(ssh, s->pktout);
9284 s->type = AUTH_TYPE_NONE;
9286 s->we_are_in = FALSE;
9288 s->tried_pubkey_config = FALSE;
9289 s->kbd_inter_refused = FALSE;
9291 /* Reset agent request state. */
9292 s->done_agent = FALSE;
9293 if (s->agent_response) {
9294 if (s->pkblob_in_agent) {
9295 s->agentp = s->pkblob_in_agent;
9297 s->agentp = s->agent_response + 5 + 4;
9303 char *methods = NULL;
9307 * Wait for the result of the last authentication request.
9310 crWaitUntilV(pktin);
9312 * Now is a convenient point to spew any banner material
9313 * that we've accumulated. (This should ensure that when
9314 * we exit the auth loop, we haven't any left to deal
9318 int size = bufchain_size(&ssh->banner);
9320 * Don't show the banner if we're operating in
9321 * non-verbose non-interactive mode. (It's probably
9322 * a script, which means nobody will read the
9323 * banner _anyway_, and moreover the printing of
9324 * the banner will screw up processing on the
9325 * output of (say) plink.)
9327 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
9328 char *banner = snewn(size, char);
9329 bufchain_fetch(&ssh->banner, banner, size);
9330 c_write_untrusted(ssh, banner, size);
9333 bufchain_clear(&ssh->banner);
9335 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
9336 logevent("Access granted");
9337 s->we_are_in = s->userauth_success = TRUE;
9341 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
9342 bombout(("Strange packet received during authentication: "
9343 "type %d", pktin->type));
9350 * OK, we're now sitting on a USERAUTH_FAILURE message, so
9351 * we can look at the string in it and know what we can
9352 * helpfully try next.
9354 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
9355 ssh_pkt_getstring(pktin, &methods, &methlen);
9356 if (!ssh2_pkt_getbool(pktin)) {
9358 * We have received an unequivocal Access
9359 * Denied. This can translate to a variety of
9360 * messages, or no message at all.
9362 * For forms of authentication which are attempted
9363 * implicitly, by which I mean without printing
9364 * anything in the window indicating that we're
9365 * trying them, we should never print 'Access
9368 * If we do print a message saying that we're
9369 * attempting some kind of authentication, it's OK
9370 * to print a followup message saying it failed -
9371 * but the message may sometimes be more specific
9372 * than simply 'Access denied'.
9374 * Additionally, if we'd just tried password
9375 * authentication, we should break out of this
9376 * whole loop so as to go back to the username
9377 * prompt (iff we're configured to allow
9378 * username change attempts).
9380 if (s->type == AUTH_TYPE_NONE) {
9382 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
9383 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
9384 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
9385 c_write_str(ssh, "Server refused our key\r\n");
9386 logevent("Server refused our key");
9387 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
9388 /* This _shouldn't_ happen except by a
9389 * protocol bug causing client and server to
9390 * disagree on what is a correct signature. */
9391 c_write_str(ssh, "Server refused public-key signature"
9392 " despite accepting key!\r\n");
9393 logevent("Server refused public-key signature"
9394 " despite accepting key!");
9395 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
9396 /* quiet, so no c_write */
9397 logevent("Server refused keyboard-interactive authentication");
9398 } else if (s->type==AUTH_TYPE_GSSAPI) {
9399 /* always quiet, so no c_write */
9400 /* also, the code down in the GSSAPI block has
9401 * already logged this in the Event Log */
9402 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
9403 logevent("Keyboard-interactive authentication failed");
9404 c_write_str(ssh, "Access denied\r\n");
9406 assert(s->type == AUTH_TYPE_PASSWORD);
9407 logevent("Password authentication failed");
9408 c_write_str(ssh, "Access denied\r\n");
9410 if (conf_get_int(ssh->conf, CONF_change_username)) {
9411 /* XXX perhaps we should allow
9412 * keyboard-interactive to do this too? */
9413 s->we_are_in = FALSE;
9418 c_write_str(ssh, "Further authentication required\r\n");
9419 logevent("Further authentication required");
9423 in_commasep_string("publickey", methods, methlen);
9425 in_commasep_string("password", methods, methlen);
9426 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
9427 in_commasep_string("keyboard-interactive", methods, methlen);
9429 if (conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
9430 in_commasep_string("gssapi-with-mic", methods, methlen)) {
9431 /* Try loading the GSS libraries and see if we
9434 ssh->gsslibs = ssh_gss_setup(ssh->conf);
9435 s->can_gssapi = (ssh->gsslibs->nlibraries > 0);
9437 /* No point in even bothering to try to load the
9438 * GSS libraries, if the user configuration and
9439 * server aren't both prepared to attempt GSSAPI
9440 * auth in the first place. */
9441 s->can_gssapi = FALSE;
9446 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9448 if (s->can_pubkey && !s->done_agent && s->nkeys) {
9451 * Attempt public-key authentication using a key from Pageant.
9454 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9456 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
9458 /* Unpack key from agent response */
9459 s->pklen = toint(GET_32BIT(s->agentp));
9461 s->pkblob = (char *)s->agentp;
9462 s->agentp += s->pklen;
9463 s->alglen = toint(GET_32BIT(s->pkblob));
9464 s->alg = s->pkblob + 4;
9465 s->commentlen = toint(GET_32BIT(s->agentp));
9467 s->commentp = (char *)s->agentp;
9468 s->agentp += s->commentlen;
9469 /* s->agentp now points at next key, if any */
9471 /* See if server will accept it */
9472 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9473 ssh2_pkt_addstring(s->pktout, ssh->username);
9474 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9475 /* service requested */
9476 ssh2_pkt_addstring(s->pktout, "publickey");
9478 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
9479 ssh2_pkt_addstring_start(s->pktout);
9480 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9481 ssh2_pkt_addstring_start(s->pktout);
9482 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9483 ssh2_pkt_send(ssh, s->pktout);
9484 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
9486 crWaitUntilV(pktin);
9487 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9489 /* Offer of key refused. */
9496 if (flags & FLAG_VERBOSE) {
9497 c_write_str(ssh, "Authenticating with "
9499 c_write(ssh, s->commentp, s->commentlen);
9500 c_write_str(ssh, "\" from agent\r\n");
9504 * Server is willing to accept the key.
9505 * Construct a SIGN_REQUEST.
9507 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9508 ssh2_pkt_addstring(s->pktout, ssh->username);
9509 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9510 /* service requested */
9511 ssh2_pkt_addstring(s->pktout, "publickey");
9513 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
9514 ssh2_pkt_addstring_start(s->pktout);
9515 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9516 ssh2_pkt_addstring_start(s->pktout);
9517 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9519 /* Ask agent for signature. */
9520 s->siglen = s->pktout->length - 5 + 4 +
9521 ssh->v2_session_id_len;
9522 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9524 s->len = 1; /* message type */
9525 s->len += 4 + s->pklen; /* key blob */
9526 s->len += 4 + s->siglen; /* data to sign */
9527 s->len += 4; /* flags */
9528 s->agentreq = snewn(4 + s->len, char);
9529 PUT_32BIT(s->agentreq, s->len);
9530 s->q = s->agentreq + 4;
9531 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
9532 PUT_32BIT(s->q, s->pklen);
9534 memcpy(s->q, s->pkblob, s->pklen);
9536 PUT_32BIT(s->q, s->siglen);
9538 /* Now the data to be signed... */
9539 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9540 PUT_32BIT(s->q, ssh->v2_session_id_len);
9543 memcpy(s->q, ssh->v2_session_id,
9544 ssh->v2_session_id_len);
9545 s->q += ssh->v2_session_id_len;
9546 memcpy(s->q, s->pktout->data + 5,
9547 s->pktout->length - 5);
9548 s->q += s->pktout->length - 5;
9549 /* And finally the (zero) flags word. */
9551 if (!agent_query(s->agentreq, s->len + 4,
9553 ssh_agent_callback, ssh)) {
9557 bombout(("Unexpected data from server"
9558 " while waiting for agent"
9562 } while (pktin || inlen > 0);
9563 vret = ssh->agent_response;
9564 s->retlen = ssh->agent_response_len;
9569 if (s->retlen >= 9 &&
9570 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
9571 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
9572 logevent("Sending Pageant's response");
9573 ssh2_add_sigblob(ssh, s->pktout,
9574 s->pkblob, s->pklen,
9576 GET_32BIT(s->ret + 5));
9577 ssh2_pkt_send(ssh, s->pktout);
9578 s->type = AUTH_TYPE_PUBLICKEY;
9580 /* FIXME: less drastic response */
9581 bombout(("Pageant failed to answer challenge"));
9587 /* Do we have any keys left to try? */
9588 if (s->pkblob_in_agent) {
9589 s->done_agent = TRUE;
9590 s->tried_pubkey_config = TRUE;
9593 if (s->keyi >= s->nkeys)
9594 s->done_agent = TRUE;
9597 } else if (s->can_pubkey && s->publickey_blob &&
9598 s->privatekey_available && !s->tried_pubkey_config) {
9600 struct ssh2_userkey *key; /* not live over crReturn */
9601 char *passphrase; /* not live over crReturn */
9603 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9605 s->tried_pubkey_config = TRUE;
9608 * Try the public key supplied in the configuration.
9610 * First, offer the public blob to see if the server is
9611 * willing to accept it.
9613 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9614 ssh2_pkt_addstring(s->pktout, ssh->username);
9615 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9616 /* service requested */
9617 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
9618 ssh2_pkt_addbool(s->pktout, FALSE);
9619 /* no signature included */
9620 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
9621 ssh2_pkt_addstring_start(s->pktout);
9622 ssh2_pkt_addstring_data(s->pktout,
9623 (char *)s->publickey_blob,
9624 s->publickey_bloblen);
9625 ssh2_pkt_send(ssh, s->pktout);
9626 logevent("Offered public key");
9628 crWaitUntilV(pktin);
9629 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9630 /* Key refused. Give up. */
9631 s->gotit = TRUE; /* reconsider message next loop */
9632 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
9633 continue; /* process this new message */
9635 logevent("Offer of public key accepted");
9638 * Actually attempt a serious authentication using
9641 if (flags & FLAG_VERBOSE) {
9642 c_write_str(ssh, "Authenticating with public key \"");
9643 c_write_str(ssh, s->publickey_comment);
9644 c_write_str(ssh, "\"\r\n");
9648 const char *error; /* not live over crReturn */
9649 if (s->privatekey_encrypted) {
9651 * Get a passphrase from the user.
9653 int ret; /* need not be kept over crReturn */
9654 s->cur_prompt = new_prompts(ssh->frontend);
9655 s->cur_prompt->to_server = FALSE;
9656 s->cur_prompt->name = dupstr("SSH key passphrase");
9657 add_prompt(s->cur_prompt,
9658 dupprintf("Passphrase for key \"%.100s\": ",
9659 s->publickey_comment),
9661 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9664 crWaitUntilV(!pktin);
9665 ret = get_userpass_input(s->cur_prompt,
9670 /* Failed to get a passphrase. Terminate. */
9671 free_prompts(s->cur_prompt);
9672 ssh_disconnect(ssh, NULL,
9673 "Unable to authenticate",
9674 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9679 dupstr(s->cur_prompt->prompts[0]->result);
9680 free_prompts(s->cur_prompt);
9682 passphrase = NULL; /* no passphrase needed */
9686 * Try decrypting the key.
9688 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9689 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
9691 /* burn the evidence */
9692 smemclr(passphrase, strlen(passphrase));
9695 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
9697 (key == SSH2_WRONG_PASSPHRASE)) {
9698 c_write_str(ssh, "Wrong passphrase\r\n");
9700 /* and loop again */
9702 c_write_str(ssh, "Unable to load private key (");
9703 c_write_str(ssh, error);
9704 c_write_str(ssh, ")\r\n");
9706 break; /* try something else */
9712 unsigned char *pkblob, *sigblob, *sigdata;
9713 int pkblob_len, sigblob_len, sigdata_len;
9717 * We have loaded the private key and the server
9718 * has announced that it's willing to accept it.
9719 * Hallelujah. Generate a signature and send it.
9721 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9722 ssh2_pkt_addstring(s->pktout, ssh->username);
9723 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9724 /* service requested */
9725 ssh2_pkt_addstring(s->pktout, "publickey");
9727 ssh2_pkt_addbool(s->pktout, TRUE);
9728 /* signature follows */
9729 ssh2_pkt_addstring(s->pktout, key->alg->name);
9730 pkblob = key->alg->public_blob(key->data,
9732 ssh2_pkt_addstring_start(s->pktout);
9733 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
9737 * The data to be signed is:
9741 * followed by everything so far placed in the
9744 sigdata_len = s->pktout->length - 5 + 4 +
9745 ssh->v2_session_id_len;
9746 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9748 sigdata = snewn(sigdata_len, unsigned char);
9750 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9751 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
9754 memcpy(sigdata+p, ssh->v2_session_id,
9755 ssh->v2_session_id_len);
9756 p += ssh->v2_session_id_len;
9757 memcpy(sigdata+p, s->pktout->data + 5,
9758 s->pktout->length - 5);
9759 p += s->pktout->length - 5;
9760 assert(p == sigdata_len);
9761 sigblob = key->alg->sign(key->data, (char *)sigdata,
9762 sigdata_len, &sigblob_len);
9763 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
9764 sigblob, sigblob_len);
9769 ssh2_pkt_send(ssh, s->pktout);
9770 logevent("Sent public key signature");
9771 s->type = AUTH_TYPE_PUBLICKEY;
9772 key->alg->freekey(key->data);
9773 sfree(key->comment);
9778 } else if (s->can_gssapi && !s->tried_gssapi) {
9780 /* GSSAPI Authentication */
9785 s->type = AUTH_TYPE_GSSAPI;
9786 s->tried_gssapi = TRUE;
9788 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
9791 * Pick the highest GSS library on the preference
9797 for (i = 0; i < ngsslibs; i++) {
9798 int want_id = conf_get_int_int(ssh->conf,
9799 CONF_ssh_gsslist, i);
9800 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
9801 if (ssh->gsslibs->libraries[j].id == want_id) {
9802 s->gsslib = &ssh->gsslibs->libraries[j];
9803 goto got_gsslib; /* double break */
9808 * We always expect to have found something in
9809 * the above loop: we only came here if there
9810 * was at least one viable GSS library, and the
9811 * preference list should always mention
9812 * everything and only change the order.
9817 if (s->gsslib->gsslogmsg)
9818 logevent(s->gsslib->gsslogmsg);
9820 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
9821 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9822 ssh2_pkt_addstring(s->pktout, ssh->username);
9823 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9824 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
9825 logevent("Attempting GSSAPI authentication");
9827 /* add mechanism info */
9828 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
9830 /* number of GSSAPI mechanisms */
9831 ssh2_pkt_adduint32(s->pktout,1);
9833 /* length of OID + 2 */
9834 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
9835 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
9838 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
9840 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
9842 ssh2_pkt_send(ssh, s->pktout);
9843 crWaitUntilV(pktin);
9844 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
9845 logevent("GSSAPI authentication request refused");
9849 /* check returned packet ... */
9851 ssh_pkt_getstring(pktin, &data, &len);
9852 s->gss_rcvtok.value = data;
9853 s->gss_rcvtok.length = len;
9854 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
9855 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
9856 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
9857 memcmp((char *)s->gss_rcvtok.value + 2,
9858 s->gss_buf.value,s->gss_buf.length) ) {
9859 logevent("GSSAPI authentication - wrong response from server");
9863 /* now start running */
9864 s->gss_stat = s->gsslib->import_name(s->gsslib,
9867 if (s->gss_stat != SSH_GSS_OK) {
9868 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
9869 logevent("GSSAPI import name failed - Bad service name");
9871 logevent("GSSAPI import name failed");
9875 /* fetch TGT into GSS engine */
9876 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
9878 if (s->gss_stat != SSH_GSS_OK) {
9879 logevent("GSSAPI authentication failed to get credentials");
9880 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9884 /* initial tokens are empty */
9885 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
9886 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
9888 /* now enter the loop */
9890 s->gss_stat = s->gsslib->init_sec_context
9894 conf_get_int(ssh->conf, CONF_gssapifwd),
9898 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
9899 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
9900 logevent("GSSAPI authentication initialisation failed");
9902 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
9903 &s->gss_buf) == SSH_GSS_OK) {
9904 logevent(s->gss_buf.value);
9905 sfree(s->gss_buf.value);
9910 logevent("GSSAPI authentication initialised");
9912 /* Client and server now exchange tokens until GSSAPI
9913 * no longer says CONTINUE_NEEDED */
9915 if (s->gss_sndtok.length != 0) {
9916 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
9917 ssh_pkt_addstring_start(s->pktout);
9918 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
9919 ssh2_pkt_send(ssh, s->pktout);
9920 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
9923 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
9924 crWaitUntilV(pktin);
9925 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
9926 logevent("GSSAPI authentication - bad server response");
9927 s->gss_stat = SSH_GSS_FAILURE;
9930 ssh_pkt_getstring(pktin, &data, &len);
9931 s->gss_rcvtok.value = data;
9932 s->gss_rcvtok.length = len;
9934 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
9936 if (s->gss_stat != SSH_GSS_OK) {
9937 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9938 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9941 logevent("GSSAPI authentication loop finished OK");
9943 /* Now send the MIC */
9945 s->pktout = ssh2_pkt_init(0);
9946 micoffset = s->pktout->length;
9947 ssh_pkt_addstring_start(s->pktout);
9948 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
9949 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
9950 ssh_pkt_addstring(s->pktout, ssh->username);
9951 ssh_pkt_addstring(s->pktout, "ssh-connection");
9952 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
9954 s->gss_buf.value = (char *)s->pktout->data + micoffset;
9955 s->gss_buf.length = s->pktout->length - micoffset;
9957 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
9958 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
9959 ssh_pkt_addstring_start(s->pktout);
9960 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
9961 ssh2_pkt_send(ssh, s->pktout);
9962 s->gsslib->free_mic(s->gsslib, &mic);
9966 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9967 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9970 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
9973 * Keyboard-interactive authentication.
9976 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
9978 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
9980 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9981 ssh2_pkt_addstring(s->pktout, ssh->username);
9982 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9983 /* service requested */
9984 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
9986 ssh2_pkt_addstring(s->pktout, ""); /* lang */
9987 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
9988 ssh2_pkt_send(ssh, s->pktout);
9990 logevent("Attempting keyboard-interactive authentication");
9992 crWaitUntilV(pktin);
9993 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
9994 /* Server is not willing to do keyboard-interactive
9995 * at all (or, bizarrely but legally, accepts the
9996 * user without actually issuing any prompts).
9997 * Give up on it entirely. */
9999 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
10000 s->kbd_inter_refused = TRUE; /* don't try it again */
10005 * Loop while the server continues to send INFO_REQUESTs.
10007 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
10009 char *name, *inst, *lang;
10010 int name_len, inst_len, lang_len;
10014 * We've got a fresh USERAUTH_INFO_REQUEST.
10015 * Get the preamble and start building a prompt.
10017 ssh_pkt_getstring(pktin, &name, &name_len);
10018 ssh_pkt_getstring(pktin, &inst, &inst_len);
10019 ssh_pkt_getstring(pktin, &lang, &lang_len);
10020 s->cur_prompt = new_prompts(ssh->frontend);
10021 s->cur_prompt->to_server = TRUE;
10024 * Get any prompt(s) from the packet.
10026 s->num_prompts = ssh_pkt_getuint32(pktin);
10027 for (i = 0; i < s->num_prompts; i++) {
10031 static char noprompt[] =
10032 "<server failed to send prompt>: ";
10034 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
10035 echo = ssh2_pkt_getbool(pktin);
10038 prompt_len = lenof(noprompt)-1;
10040 add_prompt(s->cur_prompt,
10041 dupprintf("%.*s", prompt_len, prompt),
10046 /* FIXME: better prefix to distinguish from
10047 * local prompts? */
10048 s->cur_prompt->name =
10049 dupprintf("SSH server: %.*s", name_len, name);
10050 s->cur_prompt->name_reqd = TRUE;
10052 s->cur_prompt->name =
10053 dupstr("SSH server authentication");
10054 s->cur_prompt->name_reqd = FALSE;
10056 /* We add a prefix to try to make it clear that a prompt
10057 * has come from the server.
10058 * FIXME: ugly to print "Using..." in prompt _every_
10059 * time round. Can this be done more subtly? */
10060 /* Special case: for reasons best known to themselves,
10061 * some servers send k-i requests with no prompts and
10062 * nothing to display. Keep quiet in this case. */
10063 if (s->num_prompts || name_len || inst_len) {
10064 s->cur_prompt->instruction =
10065 dupprintf("Using keyboard-interactive authentication.%s%.*s",
10066 inst_len ? "\n" : "", inst_len, inst);
10067 s->cur_prompt->instr_reqd = TRUE;
10069 s->cur_prompt->instr_reqd = FALSE;
10073 * Display any instructions, and get the user's
10077 int ret; /* not live over crReturn */
10078 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10081 crWaitUntilV(!pktin);
10082 ret = get_userpass_input(s->cur_prompt, in, inlen);
10087 * Failed to get responses. Terminate.
10089 free_prompts(s->cur_prompt);
10090 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10091 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10098 * Send the response(s) to the server.
10100 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
10101 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
10102 for (i=0; i < s->num_prompts; i++) {
10103 ssh2_pkt_addstring(s->pktout,
10104 s->cur_prompt->prompts[i]->result);
10106 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10109 * Free the prompts structure from this iteration.
10110 * If there's another, a new one will be allocated
10111 * when we return to the top of this while loop.
10113 free_prompts(s->cur_prompt);
10116 * Get the next packet in case it's another
10119 crWaitUntilV(pktin);
10124 * We should have SUCCESS or FAILURE now.
10128 } else if (s->can_passwd) {
10131 * Plain old password authentication.
10133 int ret; /* not live over crReturn */
10134 int changereq_first_time; /* not live over crReturn */
10136 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
10138 s->cur_prompt = new_prompts(ssh->frontend);
10139 s->cur_prompt->to_server = TRUE;
10140 s->cur_prompt->name = dupstr("SSH password");
10141 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
10146 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10149 crWaitUntilV(!pktin);
10150 ret = get_userpass_input(s->cur_prompt, in, inlen);
10155 * Failed to get responses. Terminate.
10157 free_prompts(s->cur_prompt);
10158 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10159 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10164 * Squirrel away the password. (We may need it later if
10165 * asked to change it.)
10167 s->password = dupstr(s->cur_prompt->prompts[0]->result);
10168 free_prompts(s->cur_prompt);
10171 * Send the password packet.
10173 * We pad out the password packet to 256 bytes to make
10174 * it harder for an attacker to find the length of the
10177 * Anyone using a password longer than 256 bytes
10178 * probably doesn't have much to worry about from
10179 * people who find out how long their password is!
10181 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10182 ssh2_pkt_addstring(s->pktout, ssh->username);
10183 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10184 /* service requested */
10185 ssh2_pkt_addstring(s->pktout, "password");
10186 ssh2_pkt_addbool(s->pktout, FALSE);
10187 ssh2_pkt_addstring(s->pktout, s->password);
10188 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10189 logevent("Sent password");
10190 s->type = AUTH_TYPE_PASSWORD;
10193 * Wait for next packet, in case it's a password change
10196 crWaitUntilV(pktin);
10197 changereq_first_time = TRUE;
10199 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
10202 * We're being asked for a new password
10203 * (perhaps not for the first time).
10204 * Loop until the server accepts it.
10207 int got_new = FALSE; /* not live over crReturn */
10208 char *prompt; /* not live over crReturn */
10209 int prompt_len; /* not live over crReturn */
10213 if (changereq_first_time)
10214 msg = "Server requested password change";
10216 msg = "Server rejected new password";
10218 c_write_str(ssh, msg);
10219 c_write_str(ssh, "\r\n");
10222 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
10224 s->cur_prompt = new_prompts(ssh->frontend);
10225 s->cur_prompt->to_server = TRUE;
10226 s->cur_prompt->name = dupstr("New SSH password");
10227 s->cur_prompt->instruction =
10228 dupprintf("%.*s", prompt_len, prompt);
10229 s->cur_prompt->instr_reqd = TRUE;
10231 * There's no explicit requirement in the protocol
10232 * for the "old" passwords in the original and
10233 * password-change messages to be the same, and
10234 * apparently some Cisco kit supports password change
10235 * by the user entering a blank password originally
10236 * and the real password subsequently, so,
10237 * reluctantly, we prompt for the old password again.
10239 * (On the other hand, some servers don't even bother
10240 * to check this field.)
10242 add_prompt(s->cur_prompt,
10243 dupstr("Current password (blank for previously entered password): "),
10245 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
10247 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
10251 * Loop until the user manages to enter the same
10256 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10259 crWaitUntilV(!pktin);
10260 ret = get_userpass_input(s->cur_prompt, in, inlen);
10265 * Failed to get responses. Terminate.
10267 /* burn the evidence */
10268 free_prompts(s->cur_prompt);
10269 smemclr(s->password, strlen(s->password));
10270 sfree(s->password);
10271 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10272 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10278 * If the user specified a new original password
10279 * (IYSWIM), overwrite any previously specified
10281 * (A side effect is that the user doesn't have to
10282 * re-enter it if they louse up the new password.)
10284 if (s->cur_prompt->prompts[0]->result[0]) {
10285 smemclr(s->password, strlen(s->password));
10286 /* burn the evidence */
10287 sfree(s->password);
10289 dupstr(s->cur_prompt->prompts[0]->result);
10293 * Check the two new passwords match.
10295 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
10296 s->cur_prompt->prompts[2]->result)
10299 /* They don't. Silly user. */
10300 c_write_str(ssh, "Passwords do not match\r\n");
10305 * Send the new password (along with the old one).
10306 * (see above for padding rationale)
10308 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10309 ssh2_pkt_addstring(s->pktout, ssh->username);
10310 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10311 /* service requested */
10312 ssh2_pkt_addstring(s->pktout, "password");
10313 ssh2_pkt_addbool(s->pktout, TRUE);
10314 ssh2_pkt_addstring(s->pktout, s->password);
10315 ssh2_pkt_addstring(s->pktout,
10316 s->cur_prompt->prompts[1]->result);
10317 free_prompts(s->cur_prompt);
10318 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10319 logevent("Sent new password");
10322 * Now see what the server has to say about it.
10323 * (If it's CHANGEREQ again, it's not happy with the
10326 crWaitUntilV(pktin);
10327 changereq_first_time = FALSE;
10332 * We need to reexamine the current pktin at the top
10333 * of the loop. Either:
10334 * - we weren't asked to change password at all, in
10335 * which case it's a SUCCESS or FAILURE with the
10337 * - we sent a new password, and the server was
10338 * either OK with it (SUCCESS or FAILURE w/partial
10339 * success) or unhappy with the _old_ password
10340 * (FAILURE w/o partial success)
10341 * In any of these cases, we go back to the top of
10342 * the loop and start again.
10347 * We don't need the old password any more, in any
10348 * case. Burn the evidence.
10350 smemclr(s->password, strlen(s->password));
10351 sfree(s->password);
10354 char *str = dupprintf("No supported authentication methods available"
10355 " (server sent: %.*s)",
10358 ssh_disconnect(ssh, str,
10359 "No supported authentication methods available",
10360 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
10370 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
10372 /* Clear up various bits and pieces from authentication. */
10373 if (s->publickey_blob) {
10374 sfree(s->publickey_algorithm);
10375 sfree(s->publickey_blob);
10376 sfree(s->publickey_comment);
10378 if (s->agent_response)
10379 sfree(s->agent_response);
10381 if (s->userauth_success && !ssh->bare_connection) {
10383 * We've just received USERAUTH_SUCCESS, and we haven't sent any
10384 * packets since. Signal the transport layer to consider enacting
10385 * delayed compression.
10387 * (Relying on we_are_in is not sufficient, as
10388 * draft-miller-secsh-compression-delayed is quite clear that it
10389 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
10390 * become set for other reasons.)
10392 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
10395 ssh->channels = newtree234(ssh_channelcmp);
10398 * Set up handlers for some connection protocol messages, so we
10399 * don't have to handle them repeatedly in this coroutine.
10401 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
10402 ssh2_msg_channel_window_adjust;
10403 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
10404 ssh2_msg_global_request;
10407 * Create the main session channel.
10409 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
10410 ssh->mainchan = NULL;
10412 ssh->mainchan = snew(struct ssh_channel);
10413 ssh->mainchan->ssh = ssh;
10414 ssh2_channel_init(ssh->mainchan);
10416 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
10418 * Just start a direct-tcpip channel and use it as the main
10421 ssh_send_port_open(ssh->mainchan,
10422 conf_get_str(ssh->conf, CONF_ssh_nc_host),
10423 conf_get_int(ssh->conf, CONF_ssh_nc_port),
10425 ssh->ncmode = TRUE;
10427 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
10428 logevent("Opening session as main channel");
10429 ssh2_pkt_send(ssh, s->pktout);
10430 ssh->ncmode = FALSE;
10432 crWaitUntilV(pktin);
10433 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
10434 bombout(("Server refused to open channel"));
10436 /* FIXME: error data comes back in FAILURE packet */
10438 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
10439 bombout(("Server's channel confirmation cited wrong channel"));
10442 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
10443 ssh->mainchan->halfopen = FALSE;
10444 ssh->mainchan->type = CHAN_MAINSESSION;
10445 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
10446 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
10447 add234(ssh->channels, ssh->mainchan);
10448 update_specials_menu(ssh->frontend);
10449 logevent("Opened main channel");
10453 * Now we have a channel, make dispatch table entries for
10454 * general channel-based messages.
10456 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
10457 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
10458 ssh2_msg_channel_data;
10459 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
10460 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
10461 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
10462 ssh2_msg_channel_open_confirmation;
10463 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
10464 ssh2_msg_channel_open_failure;
10465 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
10466 ssh2_msg_channel_request;
10467 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
10468 ssh2_msg_channel_open;
10469 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
10470 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
10473 * Now the connection protocol is properly up and running, with
10474 * all those dispatch table entries, so it's safe to let
10475 * downstreams start trying to open extra channels through us.
10477 if (ssh->connshare)
10478 share_activate(ssh->connshare, ssh->v_s);
10480 if (ssh->mainchan && ssh_is_simple(ssh)) {
10482 * This message indicates to the server that we promise
10483 * not to try to run any other channel in parallel with
10484 * this one, so it's safe for it to advertise a very large
10485 * window and leave the flow control to TCP.
10487 s->pktout = ssh2_chanreq_init(ssh->mainchan,
10488 "simple@putty.projects.tartarus.org",
10490 ssh2_pkt_send(ssh, s->pktout);
10494 * Enable port forwardings.
10496 ssh_setup_portfwd(ssh, ssh->conf);
10498 if (ssh->mainchan && !ssh->ncmode) {
10500 * Send the CHANNEL_REQUESTS for the main session channel.
10501 * Each one is handled by its own little asynchronous
10505 /* Potentially enable X11 forwarding. */
10506 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
10508 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
10510 if (!ssh->x11disp) {
10511 /* FIXME: return an error message from x11_setup_display */
10512 logevent("X11 forwarding not enabled: unable to"
10513 " initialise X display");
10515 ssh->x11auth = x11_invent_fake_auth
10516 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
10517 ssh->x11auth->disp = ssh->x11disp;
10519 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
10523 /* Potentially enable agent forwarding. */
10524 if (ssh_agent_forwarding_permitted(ssh))
10525 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
10527 /* Now allocate a pty for the session. */
10528 if (!conf_get_int(ssh->conf, CONF_nopty))
10529 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
10531 /* Send environment variables. */
10532 ssh2_setup_env(ssh->mainchan, NULL, NULL);
10535 * Start a shell or a remote command. We may have to attempt
10536 * this twice if the config data has provided a second choice
10543 if (ssh->fallback_cmd) {
10544 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
10545 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
10547 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
10548 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
10552 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
10553 ssh2_response_authconn, NULL);
10554 ssh2_pkt_addstring(s->pktout, cmd);
10556 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
10557 ssh2_response_authconn, NULL);
10558 ssh2_pkt_addstring(s->pktout, cmd);
10560 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
10561 ssh2_response_authconn, NULL);
10563 ssh2_pkt_send(ssh, s->pktout);
10565 crWaitUntilV(pktin);
10567 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
10568 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
10569 bombout(("Unexpected response to shell/command request:"
10570 " packet type %d", pktin->type));
10574 * We failed to start the command. If this is the
10575 * fallback command, we really are finished; if it's
10576 * not, and if the fallback command exists, try falling
10577 * back to it before complaining.
10579 if (!ssh->fallback_cmd &&
10580 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
10581 logevent("Primary command failed; attempting fallback");
10582 ssh->fallback_cmd = TRUE;
10585 bombout(("Server refused to start a shell/command"));
10588 logevent("Started a shell/command");
10593 ssh->editing = ssh->echoing = TRUE;
10596 ssh->state = SSH_STATE_SESSION;
10597 if (ssh->size_needed)
10598 ssh_size(ssh, ssh->term_width, ssh->term_height);
10599 if (ssh->eof_needed)
10600 ssh_special(ssh, TS_EOF);
10606 ldisc_echoedit_update(ssh->ldisc); /* cause ldisc to notice changes */
10611 s->try_send = FALSE;
10615 * _All_ the connection-layer packets we expect to
10616 * receive are now handled by the dispatch table.
10617 * Anything that reaches here must be bogus.
10620 bombout(("Strange packet received: type %d", pktin->type));
10622 } else if (ssh->mainchan) {
10624 * We have spare data. Add it to the channel buffer.
10626 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
10627 s->try_send = TRUE;
10631 struct ssh_channel *c;
10633 * Try to send data on all channels if we can.
10635 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
10636 if (c->type != CHAN_SHARING)
10637 ssh2_try_send_and_unthrottle(ssh, c);
10645 * Handlers for SSH-2 messages that might arrive at any moment.
10647 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
10649 /* log reason code in disconnect message */
10651 int reason, msglen;
10653 reason = ssh_pkt_getuint32(pktin);
10654 ssh_pkt_getstring(pktin, &msg, &msglen);
10656 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
10657 buf = dupprintf("Received disconnect message (%s)",
10658 ssh2_disconnect_reasons[reason]);
10660 buf = dupprintf("Received disconnect message (unknown"
10661 " type %d)", reason);
10665 buf = dupprintf("Disconnection message text: %.*s",
10668 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
10670 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
10671 ssh2_disconnect_reasons[reason] : "unknown",
10676 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
10678 /* log the debug message */
10682 /* XXX maybe we should actually take notice of the return value */
10683 ssh2_pkt_getbool(pktin);
10684 ssh_pkt_getstring(pktin, &msg, &msglen);
10686 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
10689 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
10691 do_ssh2_transport(ssh, NULL, 0, pktin);
10695 * Called if we receive a packet that isn't allowed by the protocol.
10696 * This only applies to packets whose meaning PuTTY understands.
10697 * Entirely unknown packets are handled below.
10699 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
10701 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
10702 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
10704 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
10708 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
10710 struct Packet *pktout;
10711 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
10712 ssh2_pkt_adduint32(pktout, pktin->sequence);
10714 * UNIMPLEMENTED messages MUST appear in the same order as the
10715 * messages they respond to. Hence, never queue them.
10717 ssh2_pkt_send_noqueue(ssh, pktout);
10721 * Handle the top-level SSH-2 protocol.
10723 static void ssh2_protocol_setup(Ssh ssh)
10728 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10730 for (i = 0; i < 256; i++)
10731 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10734 * Initially, we only accept transport messages (and a few generic
10735 * ones). do_ssh2_authconn will add more when it starts.
10736 * Messages that are understood but not currently acceptable go to
10737 * ssh2_msg_unexpected.
10739 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10740 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
10741 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
10742 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
10743 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
10744 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
10745 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
10746 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
10747 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
10748 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
10749 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
10750 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
10751 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
10752 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
10753 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
10754 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
10755 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
10756 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
10757 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
10758 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10759 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10760 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10761 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10762 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10763 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10764 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10765 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10766 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10767 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10768 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10769 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10770 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10771 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10774 * These messages have a special handler from the start.
10776 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10777 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
10778 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10781 static void ssh2_bare_connection_protocol_setup(Ssh ssh)
10786 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10788 for (i = 0; i < 256; i++)
10789 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10792 * Initially, we set all ssh-connection messages to 'unexpected';
10793 * do_ssh2_authconn will fill things in properly. We also handle a
10794 * couple of messages from the transport protocol which aren't
10795 * related to key exchange (UNIMPLEMENTED, IGNORE, DEBUG,
10798 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10799 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10800 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10801 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10802 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10803 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10804 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10805 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10806 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10807 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10808 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10809 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10810 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10811 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10813 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10816 * These messages have a special handler from the start.
10818 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10819 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore;
10820 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10823 static void ssh2_timer(void *ctx, unsigned long now)
10825 Ssh ssh = (Ssh)ctx;
10827 if (ssh->state == SSH_STATE_CLOSED)
10830 if (!ssh->kex_in_progress && !ssh->bare_connection &&
10831 conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
10832 now == ssh->next_rekey) {
10833 do_ssh2_transport(ssh, "timeout", -1, NULL);
10837 static void ssh2_protocol(Ssh ssh, const void *vin, int inlen,
10838 struct Packet *pktin)
10840 const unsigned char *in = (const unsigned char *)vin;
10841 if (ssh->state == SSH_STATE_CLOSED)
10845 ssh->incoming_data_size += pktin->encrypted_len;
10846 if (!ssh->kex_in_progress &&
10847 ssh->max_data_size != 0 &&
10848 ssh->incoming_data_size > ssh->max_data_size)
10849 do_ssh2_transport(ssh, "too much data received", -1, NULL);
10853 ssh->packet_dispatch[pktin->type](ssh, pktin);
10854 else if (!ssh->protocol_initial_phase_done)
10855 do_ssh2_transport(ssh, in, inlen, pktin);
10857 do_ssh2_authconn(ssh, in, inlen, pktin);
10860 static void ssh2_bare_connection_protocol(Ssh ssh, const void *vin, int inlen,
10861 struct Packet *pktin)
10863 const unsigned char *in = (const unsigned char *)vin;
10864 if (ssh->state == SSH_STATE_CLOSED)
10868 ssh->packet_dispatch[pktin->type](ssh, pktin);
10870 do_ssh2_authconn(ssh, in, inlen, pktin);
10873 static void ssh_cache_conf_values(Ssh ssh)
10875 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
10879 * Called to set up the connection.
10881 * Returns an error message, or NULL on success.
10883 static const char *ssh_init(void *frontend_handle, void **backend_handle,
10885 const char *host, int port, char **realhost,
10886 int nodelay, int keepalive)
10891 ssh = snew(struct ssh_tag);
10892 ssh->conf = conf_copy(conf);
10893 ssh_cache_conf_values(ssh);
10894 ssh->version = 0; /* when not ready yet */
10896 ssh->cipher = NULL;
10897 ssh->v1_cipher_ctx = NULL;
10898 ssh->crcda_ctx = NULL;
10899 ssh->cscipher = NULL;
10900 ssh->cs_cipher_ctx = NULL;
10901 ssh->sccipher = NULL;
10902 ssh->sc_cipher_ctx = NULL;
10904 ssh->cs_mac_ctx = NULL;
10906 ssh->sc_mac_ctx = NULL;
10907 ssh->cscomp = NULL;
10908 ssh->cs_comp_ctx = NULL;
10909 ssh->sccomp = NULL;
10910 ssh->sc_comp_ctx = NULL;
10912 ssh->kex_ctx = NULL;
10913 ssh->hostkey = NULL;
10914 ssh->hostkey_str = NULL;
10915 ssh->exitcode = -1;
10916 ssh->close_expected = FALSE;
10917 ssh->clean_exit = FALSE;
10918 ssh->state = SSH_STATE_PREPACKET;
10919 ssh->size_needed = FALSE;
10920 ssh->eof_needed = FALSE;
10922 ssh->logctx = NULL;
10923 ssh->deferred_send_data = NULL;
10924 ssh->deferred_len = 0;
10925 ssh->deferred_size = 0;
10926 ssh->fallback_cmd = 0;
10927 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
10928 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
10929 ssh->x11disp = NULL;
10930 ssh->x11auth = NULL;
10931 ssh->x11authtree = newtree234(x11_authcmp);
10932 ssh->v1_compressing = FALSE;
10933 ssh->v2_outgoing_sequence = 0;
10934 ssh->ssh1_rdpkt_crstate = 0;
10935 ssh->ssh2_rdpkt_crstate = 0;
10936 ssh->ssh2_bare_rdpkt_crstate = 0;
10937 ssh->ssh_gotdata_crstate = 0;
10938 ssh->do_ssh1_connection_crstate = 0;
10939 ssh->do_ssh_init_state = NULL;
10940 ssh->do_ssh_connection_init_state = NULL;
10941 ssh->do_ssh1_login_state = NULL;
10942 ssh->do_ssh2_transport_state = NULL;
10943 ssh->do_ssh2_authconn_state = NULL;
10946 ssh->mainchan = NULL;
10947 ssh->throttled_all = 0;
10948 ssh->v1_stdout_throttling = 0;
10950 ssh->queuelen = ssh->queuesize = 0;
10951 ssh->queueing = FALSE;
10952 ssh->qhead = ssh->qtail = NULL;
10953 ssh->deferred_rekey_reason = NULL;
10954 bufchain_init(&ssh->queued_incoming_data);
10955 ssh->frozen = FALSE;
10956 ssh->username = NULL;
10957 ssh->sent_console_eof = FALSE;
10958 ssh->got_pty = FALSE;
10959 ssh->bare_connection = FALSE;
10960 ssh->X11_fwd_enabled = FALSE;
10961 ssh->connshare = NULL;
10962 ssh->attempting_connshare = FALSE;
10964 *backend_handle = ssh;
10967 if (crypto_startup() == 0)
10968 return "Microsoft high encryption pack not installed!";
10971 ssh->frontend = frontend_handle;
10972 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
10973 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
10975 ssh->channels = NULL;
10976 ssh->rportfwds = NULL;
10977 ssh->portfwds = NULL;
10982 ssh->conn_throttle_count = 0;
10983 ssh->overall_bufsize = 0;
10984 ssh->fallback_cmd = 0;
10986 ssh->protocol = NULL;
10988 ssh->protocol_initial_phase_done = FALSE;
10990 ssh->pinger = NULL;
10992 ssh->incoming_data_size = ssh->outgoing_data_size =
10993 ssh->deferred_data_size = 0L;
10994 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10995 CONF_ssh_rekey_data));
10996 ssh->kex_in_progress = FALSE;
10999 ssh->gsslibs = NULL;
11002 random_ref(); /* do this now - may be needed by sharing setup code */
11004 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
11013 static void ssh_free(void *handle)
11015 Ssh ssh = (Ssh) handle;
11016 struct ssh_channel *c;
11017 struct ssh_rportfwd *pf;
11018 struct X11FakeAuth *auth;
11020 if (ssh->v1_cipher_ctx)
11021 ssh->cipher->free_context(ssh->v1_cipher_ctx);
11022 if (ssh->cs_cipher_ctx)
11023 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
11024 if (ssh->sc_cipher_ctx)
11025 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
11026 if (ssh->cs_mac_ctx)
11027 ssh->csmac->free_context(ssh->cs_mac_ctx);
11028 if (ssh->sc_mac_ctx)
11029 ssh->scmac->free_context(ssh->sc_mac_ctx);
11030 if (ssh->cs_comp_ctx) {
11032 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
11034 zlib_compress_cleanup(ssh->cs_comp_ctx);
11036 if (ssh->sc_comp_ctx) {
11038 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
11040 zlib_decompress_cleanup(ssh->sc_comp_ctx);
11043 dh_cleanup(ssh->kex_ctx);
11044 sfree(ssh->savedhost);
11046 while (ssh->queuelen-- > 0)
11047 ssh_free_packet(ssh->queue[ssh->queuelen]);
11050 while (ssh->qhead) {
11051 struct queued_handler *qh = ssh->qhead;
11052 ssh->qhead = qh->next;
11055 ssh->qhead = ssh->qtail = NULL;
11057 if (ssh->channels) {
11058 while ((c = delpos234(ssh->channels, 0)) != NULL) {
11061 if (c->u.x11.xconn != NULL)
11062 x11_close(c->u.x11.xconn);
11064 case CHAN_SOCKDATA:
11065 case CHAN_SOCKDATA_DORMANT:
11066 if (c->u.pfd.pf != NULL)
11067 pfd_close(c->u.pfd.pf);
11070 if (ssh->version == 2) {
11071 struct outstanding_channel_request *ocr, *nocr;
11072 ocr = c->v.v2.chanreq_head;
11074 ocr->handler(c, NULL, ocr->ctx);
11079 bufchain_clear(&c->v.v2.outbuffer);
11083 freetree234(ssh->channels);
11084 ssh->channels = NULL;
11087 if (ssh->connshare)
11088 sharestate_free(ssh->connshare);
11090 if (ssh->rportfwds) {
11091 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
11093 freetree234(ssh->rportfwds);
11094 ssh->rportfwds = NULL;
11096 sfree(ssh->deferred_send_data);
11098 x11_free_display(ssh->x11disp);
11099 while ((auth = delpos234(ssh->x11authtree, 0)) != NULL)
11100 x11_free_fake_auth(auth);
11101 freetree234(ssh->x11authtree);
11102 sfree(ssh->do_ssh_init_state);
11103 sfree(ssh->do_ssh1_login_state);
11104 sfree(ssh->do_ssh2_transport_state);
11105 sfree(ssh->do_ssh2_authconn_state);
11108 sfree(ssh->fullhostname);
11109 sfree(ssh->hostkey_str);
11110 if (ssh->crcda_ctx) {
11111 crcda_free_context(ssh->crcda_ctx);
11112 ssh->crcda_ctx = NULL;
11115 ssh_do_close(ssh, TRUE);
11116 expire_timer_context(ssh);
11118 pinger_free(ssh->pinger);
11119 bufchain_clear(&ssh->queued_incoming_data);
11120 sfree(ssh->username);
11121 conf_free(ssh->conf);
11124 ssh_gss_cleanup(ssh->gsslibs);
11132 * Reconfigure the SSH backend.
11134 static void ssh_reconfig(void *handle, Conf *conf)
11136 Ssh ssh = (Ssh) handle;
11137 const char *rekeying = NULL;
11138 int rekey_mandatory = FALSE;
11139 unsigned long old_max_data_size;
11142 pinger_reconfig(ssh->pinger, ssh->conf, conf);
11144 ssh_setup_portfwd(ssh, conf);
11146 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
11147 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
11149 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
11150 unsigned long now = GETTICKCOUNT();
11152 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
11153 rekeying = "timeout shortened";
11155 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
11159 old_max_data_size = ssh->max_data_size;
11160 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
11161 CONF_ssh_rekey_data));
11162 if (old_max_data_size != ssh->max_data_size &&
11163 ssh->max_data_size != 0) {
11164 if (ssh->outgoing_data_size > ssh->max_data_size ||
11165 ssh->incoming_data_size > ssh->max_data_size)
11166 rekeying = "data limit lowered";
11169 if (conf_get_int(ssh->conf, CONF_compression) !=
11170 conf_get_int(conf, CONF_compression)) {
11171 rekeying = "compression setting changed";
11172 rekey_mandatory = TRUE;
11175 for (i = 0; i < CIPHER_MAX; i++)
11176 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
11177 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
11178 rekeying = "cipher settings changed";
11179 rekey_mandatory = TRUE;
11181 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
11182 conf_get_int(conf, CONF_ssh2_des_cbc)) {
11183 rekeying = "cipher settings changed";
11184 rekey_mandatory = TRUE;
11187 conf_free(ssh->conf);
11188 ssh->conf = conf_copy(conf);
11189 ssh_cache_conf_values(ssh);
11191 if (!ssh->bare_connection && rekeying) {
11192 if (!ssh->kex_in_progress) {
11193 do_ssh2_transport(ssh, rekeying, -1, NULL);
11194 } else if (rekey_mandatory) {
11195 ssh->deferred_rekey_reason = rekeying;
11201 * Called to send data down the SSH connection.
11203 static int ssh_send(void *handle, const char *buf, int len)
11205 Ssh ssh = (Ssh) handle;
11207 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
11210 ssh->protocol(ssh, (const unsigned char *)buf, len, 0);
11212 return ssh_sendbuffer(ssh);
11216 * Called to query the current amount of buffered stdin data.
11218 static int ssh_sendbuffer(void *handle)
11220 Ssh ssh = (Ssh) handle;
11221 int override_value;
11223 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
11227 * If the SSH socket itself has backed up, add the total backup
11228 * size on that to any individual buffer on the stdin channel.
11230 override_value = 0;
11231 if (ssh->throttled_all)
11232 override_value = ssh->overall_bufsize;
11234 if (ssh->version == 1) {
11235 return override_value;
11236 } else if (ssh->version == 2) {
11237 if (!ssh->mainchan)
11238 return override_value;
11240 return (override_value +
11241 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
11248 * Called to set the size of the window from SSH's POV.
11250 static void ssh_size(void *handle, int width, int height)
11252 Ssh ssh = (Ssh) handle;
11253 struct Packet *pktout;
11255 ssh->term_width = width;
11256 ssh->term_height = height;
11258 switch (ssh->state) {
11259 case SSH_STATE_BEFORE_SIZE:
11260 case SSH_STATE_PREPACKET:
11261 case SSH_STATE_CLOSED:
11262 break; /* do nothing */
11263 case SSH_STATE_INTERMED:
11264 ssh->size_needed = TRUE; /* buffer for later */
11266 case SSH_STATE_SESSION:
11267 if (!conf_get_int(ssh->conf, CONF_nopty)) {
11268 if (ssh->version == 1) {
11269 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
11270 PKT_INT, ssh->term_height,
11271 PKT_INT, ssh->term_width,
11272 PKT_INT, 0, PKT_INT, 0, PKT_END);
11273 } else if (ssh->mainchan) {
11274 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
11276 ssh2_pkt_adduint32(pktout, ssh->term_width);
11277 ssh2_pkt_adduint32(pktout, ssh->term_height);
11278 ssh2_pkt_adduint32(pktout, 0);
11279 ssh2_pkt_adduint32(pktout, 0);
11280 ssh2_pkt_send(ssh, pktout);
11288 * Return a list of the special codes that make sense in this
11291 static const struct telnet_special *ssh_get_specials(void *handle)
11293 static const struct telnet_special ssh1_ignore_special[] = {
11294 {"IGNORE message", TS_NOP}
11296 static const struct telnet_special ssh2_ignore_special[] = {
11297 {"IGNORE message", TS_NOP},
11299 static const struct telnet_special ssh2_rekey_special[] = {
11300 {"Repeat key exchange", TS_REKEY},
11302 static const struct telnet_special ssh2_session_specials[] = {
11305 /* These are the signal names defined by RFC 4254.
11306 * They include all the ISO C signals, but are a subset of the POSIX
11307 * required signals. */
11308 {"SIGINT (Interrupt)", TS_SIGINT},
11309 {"SIGTERM (Terminate)", TS_SIGTERM},
11310 {"SIGKILL (Kill)", TS_SIGKILL},
11311 {"SIGQUIT (Quit)", TS_SIGQUIT},
11312 {"SIGHUP (Hangup)", TS_SIGHUP},
11313 {"More signals", TS_SUBMENU},
11314 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
11315 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
11316 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
11317 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
11318 {NULL, TS_EXITMENU}
11320 static const struct telnet_special specials_end[] = {
11321 {NULL, TS_EXITMENU}
11323 /* XXX review this length for any changes: */
11324 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
11325 lenof(ssh2_rekey_special) +
11326 lenof(ssh2_session_specials) +
11327 lenof(specials_end)];
11328 Ssh ssh = (Ssh) handle;
11330 #define ADD_SPECIALS(name) \
11332 assert((i + lenof(name)) <= lenof(ssh_specials)); \
11333 memcpy(&ssh_specials[i], name, sizeof name); \
11334 i += lenof(name); \
11337 if (ssh->version == 1) {
11338 /* Don't bother offering IGNORE if we've decided the remote
11339 * won't cope with it, since we wouldn't bother sending it if
11341 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11342 ADD_SPECIALS(ssh1_ignore_special);
11343 } else if (ssh->version == 2) {
11344 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
11345 ADD_SPECIALS(ssh2_ignore_special);
11346 if (!(ssh->remote_bugs & BUG_SSH2_REKEY) && !ssh->bare_connection)
11347 ADD_SPECIALS(ssh2_rekey_special);
11349 ADD_SPECIALS(ssh2_session_specials);
11350 } /* else we're not ready yet */
11353 ADD_SPECIALS(specials_end);
11354 return ssh_specials;
11358 #undef ADD_SPECIALS
11362 * Send special codes. TS_EOF is useful for `plink', so you
11363 * can send an EOF and collect resulting output (e.g. `plink
11366 static void ssh_special(void *handle, Telnet_Special code)
11368 Ssh ssh = (Ssh) handle;
11369 struct Packet *pktout;
11371 if (code == TS_EOF) {
11372 if (ssh->state != SSH_STATE_SESSION) {
11374 * Buffer the EOF in case we are pre-SESSION, so we can
11375 * send it as soon as we reach SESSION.
11377 if (code == TS_EOF)
11378 ssh->eof_needed = TRUE;
11381 if (ssh->version == 1) {
11382 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
11383 } else if (ssh->mainchan) {
11384 sshfwd_write_eof(ssh->mainchan);
11385 ssh->send_ok = 0; /* now stop trying to read from stdin */
11387 logevent("Sent EOF message");
11388 } else if (code == TS_PING || code == TS_NOP) {
11389 if (ssh->state == SSH_STATE_CLOSED
11390 || ssh->state == SSH_STATE_PREPACKET) return;
11391 if (ssh->version == 1) {
11392 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11393 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
11395 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
11396 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
11397 ssh2_pkt_addstring_start(pktout);
11398 ssh2_pkt_send_noqueue(ssh, pktout);
11401 } else if (code == TS_REKEY) {
11402 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11403 ssh->version == 2) {
11404 do_ssh2_transport(ssh, "at user request", -1, NULL);
11406 } else if (code == TS_BRK) {
11407 if (ssh->state == SSH_STATE_CLOSED
11408 || ssh->state == SSH_STATE_PREPACKET) return;
11409 if (ssh->version == 1) {
11410 logevent("Unable to send BREAK signal in SSH-1");
11411 } else if (ssh->mainchan) {
11412 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
11413 ssh2_pkt_adduint32(pktout, 0); /* default break length */
11414 ssh2_pkt_send(ssh, pktout);
11417 /* Is is a POSIX signal? */
11418 const char *signame = NULL;
11419 if (code == TS_SIGABRT) signame = "ABRT";
11420 if (code == TS_SIGALRM) signame = "ALRM";
11421 if (code == TS_SIGFPE) signame = "FPE";
11422 if (code == TS_SIGHUP) signame = "HUP";
11423 if (code == TS_SIGILL) signame = "ILL";
11424 if (code == TS_SIGINT) signame = "INT";
11425 if (code == TS_SIGKILL) signame = "KILL";
11426 if (code == TS_SIGPIPE) signame = "PIPE";
11427 if (code == TS_SIGQUIT) signame = "QUIT";
11428 if (code == TS_SIGSEGV) signame = "SEGV";
11429 if (code == TS_SIGTERM) signame = "TERM";
11430 if (code == TS_SIGUSR1) signame = "USR1";
11431 if (code == TS_SIGUSR2) signame = "USR2";
11432 /* The SSH-2 protocol does in principle support arbitrary named
11433 * signals, including signame@domain, but we don't support those. */
11435 /* It's a signal. */
11436 if (ssh->version == 2 && ssh->mainchan) {
11437 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
11438 ssh2_pkt_addstring(pktout, signame);
11439 ssh2_pkt_send(ssh, pktout);
11440 logeventf(ssh, "Sent signal SIG%s", signame);
11443 /* Never heard of it. Do nothing */
11448 void *new_sock_channel(void *handle, struct PortForwarding *pf)
11450 Ssh ssh = (Ssh) handle;
11451 struct ssh_channel *c;
11452 c = snew(struct ssh_channel);
11455 ssh2_channel_init(c);
11456 c->halfopen = TRUE;
11457 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
11459 add234(ssh->channels, c);
11463 unsigned ssh_alloc_sharing_channel(Ssh ssh, void *sharing_ctx)
11465 struct ssh_channel *c;
11466 c = snew(struct ssh_channel);
11469 ssh2_channel_init(c);
11470 c->type = CHAN_SHARING;
11471 c->u.sharing.ctx = sharing_ctx;
11472 add234(ssh->channels, c);
11476 void ssh_delete_sharing_channel(Ssh ssh, unsigned localid)
11478 struct ssh_channel *c;
11480 c = find234(ssh->channels, &localid, ssh_channelfind);
11482 ssh_channel_destroy(c);
11485 void ssh_send_packet_from_downstream(Ssh ssh, unsigned id, int type,
11486 const void *data, int datalen,
11487 const char *additional_log_text)
11489 struct Packet *pkt;
11491 pkt = ssh2_pkt_init(type);
11492 pkt->downstream_id = id;
11493 pkt->additional_log_text = additional_log_text;
11494 ssh2_pkt_adddata(pkt, data, datalen);
11495 ssh2_pkt_send(ssh, pkt);
11499 * This is called when stdout/stderr (the entity to which
11500 * from_backend sends data) manages to clear some backlog.
11502 static void ssh_unthrottle(void *handle, int bufsize)
11504 Ssh ssh = (Ssh) handle;
11507 if (ssh->version == 1) {
11508 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
11509 ssh->v1_stdout_throttling = 0;
11510 ssh_throttle_conn(ssh, -1);
11513 if (ssh->mainchan) {
11514 ssh2_set_window(ssh->mainchan,
11515 bufsize < ssh->mainchan->v.v2.locmaxwin ?
11516 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
11517 if (ssh_is_simple(ssh))
11520 buflimit = ssh->mainchan->v.v2.locmaxwin;
11521 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
11522 ssh->mainchan->throttling_conn = 0;
11523 ssh_throttle_conn(ssh, -1);
11529 * Now process any SSH connection data that was stashed in our
11530 * queue while we were frozen.
11532 ssh_process_queued_incoming_data(ssh);
11535 void ssh_send_port_open(void *channel, const char *hostname, int port,
11538 struct ssh_channel *c = (struct ssh_channel *)channel;
11540 struct Packet *pktout;
11542 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
11544 if (ssh->version == 1) {
11545 send_packet(ssh, SSH1_MSG_PORT_OPEN,
11546 PKT_INT, c->localid,
11549 /* PKT_STR, <org:orgport>, */
11552 pktout = ssh2_chanopen_init(c, "direct-tcpip");
11554 char *trimmed_host = host_strduptrim(hostname);
11555 ssh2_pkt_addstring(pktout, trimmed_host);
11556 sfree(trimmed_host);
11558 ssh2_pkt_adduint32(pktout, port);
11560 * We make up values for the originator data; partly it's
11561 * too much hassle to keep track, and partly I'm not
11562 * convinced the server should be told details like that
11563 * about my local network configuration.
11564 * The "originator IP address" is syntactically a numeric
11565 * IP address, and some servers (e.g., Tectia) get upset
11566 * if it doesn't match this syntax.
11568 ssh2_pkt_addstring(pktout, "0.0.0.0");
11569 ssh2_pkt_adduint32(pktout, 0);
11570 ssh2_pkt_send(ssh, pktout);
11574 static int ssh_connected(void *handle)
11576 Ssh ssh = (Ssh) handle;
11577 return ssh->s != NULL;
11580 static int ssh_sendok(void *handle)
11582 Ssh ssh = (Ssh) handle;
11583 return ssh->send_ok;
11586 static int ssh_ldisc(void *handle, int option)
11588 Ssh ssh = (Ssh) handle;
11589 if (option == LD_ECHO)
11590 return ssh->echoing;
11591 if (option == LD_EDIT)
11592 return ssh->editing;
11596 static void ssh_provide_ldisc(void *handle, void *ldisc)
11598 Ssh ssh = (Ssh) handle;
11599 ssh->ldisc = ldisc;
11602 static void ssh_provide_logctx(void *handle, void *logctx)
11604 Ssh ssh = (Ssh) handle;
11605 ssh->logctx = logctx;
11608 static int ssh_return_exitcode(void *handle)
11610 Ssh ssh = (Ssh) handle;
11611 if (ssh->s != NULL)
11614 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
11618 * cfg_info for SSH is the protocol running in this session.
11619 * (1 or 2 for the full SSH-1 or SSH-2 protocol; -1 for the bare
11620 * SSH-2 connection protocol, i.e. a downstream; 0 for not-decided-yet.)
11622 static int ssh_cfg_info(void *handle)
11624 Ssh ssh = (Ssh) handle;
11625 if (ssh->version == 0)
11626 return 0; /* don't know yet */
11627 else if (ssh->bare_connection)
11630 return ssh->version;
11634 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
11635 * that fails. This variable is the means by which scp.c can reach
11636 * into the SSH code and find out which one it got.
11638 extern int ssh_fallback_cmd(void *handle)
11640 Ssh ssh = (Ssh) handle;
11641 return ssh->fallback_cmd;
11644 Backend ssh_backend = {
11654 ssh_return_exitcode,
11658 ssh_provide_logctx,
11661 ssh_test_for_upstream,