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 */
3590 * Connect to specified host and port.
3591 * Returns an error message, or NULL on success.
3592 * Also places the canonical host name into `realhost'. It must be
3593 * freed by the caller.
3595 static const char *connect_to_host(Ssh ssh, const char *host, int port,
3596 char **realhost, int nodelay, int keepalive)
3598 static const struct plug_function_table fn_table = {
3609 int addressfamily, sshprot;
3611 ssh_hostport_setup(host, port, ssh->conf,
3612 &ssh->savedhost, &ssh->savedport, &loghost);
3614 ssh->fn = &fn_table; /* make 'ssh' usable as a Plug */
3617 * Try connection-sharing, in case that means we don't open a
3618 * socket after all. ssh_connection_sharing_init will connect to a
3619 * previously established upstream if it can, and failing that,
3620 * establish a listening socket for _us_ to be the upstream. In
3621 * the latter case it will return NULL just as if it had done
3622 * nothing, because here we only need to care if we're a
3623 * downstream and need to do our connection setup differently.
3625 ssh->connshare = NULL;
3626 ssh->attempting_connshare = TRUE; /* affects socket logging behaviour */
3627 ssh->s = ssh_connection_sharing_init(ssh->savedhost, ssh->savedport,
3628 ssh->conf, ssh, &ssh->connshare);
3629 ssh->attempting_connshare = FALSE;
3630 if (ssh->s != NULL) {
3632 * We are a downstream.
3634 ssh->bare_connection = TRUE;
3635 ssh->do_ssh_init = do_ssh_connection_init;
3636 ssh->fullhostname = NULL;
3637 *realhost = dupstr(host); /* best we can do */
3640 * We're not a downstream, so open a normal socket.
3642 ssh->do_ssh_init = do_ssh_init;
3647 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
3648 logeventf(ssh, "Looking up host \"%s\"%s", host,
3649 (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
3650 (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
3651 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily);
3652 if ((err = sk_addr_error(addr)) != NULL) {
3656 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3658 ssh->s = new_connection(addr, *realhost, port,
3659 0, 1, nodelay, keepalive,
3660 (Plug) ssh, ssh->conf);
3661 if ((err = sk_socket_error(ssh->s)) != NULL) {
3663 notify_remote_exit(ssh->frontend);
3669 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3670 * send the version string too.
3672 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3675 if (sshprot == 3 && !ssh->bare_connection) {
3677 ssh_send_verstring(ssh, "SSH-", NULL);
3681 * loghost, if configured, overrides realhost.
3685 *realhost = dupstr(loghost);
3692 * Throttle or unthrottle the SSH connection.
3694 static void ssh_throttle_conn(Ssh ssh, int adjust)
3696 int old_count = ssh->conn_throttle_count;
3697 ssh->conn_throttle_count += adjust;
3698 assert(ssh->conn_throttle_count >= 0);
3699 if (ssh->conn_throttle_count && !old_count) {
3700 ssh_set_frozen(ssh, 1);
3701 } else if (!ssh->conn_throttle_count && old_count) {
3702 ssh_set_frozen(ssh, 0);
3707 * Throttle or unthrottle _all_ local data streams (for when sends
3708 * on the SSH connection itself back up).
3710 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3713 struct ssh_channel *c;
3715 if (enable == ssh->throttled_all)
3717 ssh->throttled_all = enable;
3718 ssh->overall_bufsize = bufsize;
3721 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3723 case CHAN_MAINSESSION:
3725 * This is treated separately, outside the switch.
3729 x11_override_throttle(c->u.x11.xconn, enable);
3732 /* Agent channels require no buffer management. */
3735 pfd_override_throttle(c->u.pfd.pf, enable);
3741 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3743 Ssh ssh = (Ssh) sshv;
3745 ssh->agent_response = reply;
3746 ssh->agent_response_len = replylen;
3748 if (ssh->version == 1)
3749 do_ssh1_login(ssh, NULL, -1, NULL);
3751 do_ssh2_authconn(ssh, NULL, -1, NULL);
3754 static void ssh_dialog_callback(void *sshv, int ret)
3756 Ssh ssh = (Ssh) sshv;
3758 ssh->user_response = ret;
3760 if (ssh->version == 1)
3761 do_ssh1_login(ssh, NULL, -1, NULL);
3763 do_ssh2_transport(ssh, NULL, -1, NULL);
3766 * This may have unfrozen the SSH connection, so do a
3769 ssh_process_queued_incoming_data(ssh);
3772 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3774 struct ssh_channel *c = (struct ssh_channel *)cv;
3776 const void *sentreply = reply;
3778 c->u.a.outstanding_requests--;
3780 /* Fake SSH_AGENT_FAILURE. */
3781 sentreply = "\0\0\0\1\5";
3784 if (ssh->version == 2) {
3785 ssh2_add_channel_data(c, sentreply, replylen);
3788 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3789 PKT_INT, c->remoteid,
3791 PKT_DATA, sentreply, replylen,
3797 * If we've already seen an incoming EOF but haven't sent an
3798 * outgoing one, this may be the moment to send it.
3800 if (c->u.a.outstanding_requests == 0 && (c->closes & CLOSES_RCVD_EOF))
3801 sshfwd_write_eof(c);
3805 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3806 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3807 * => log `wire_reason'.
3809 static void ssh_disconnect(Ssh ssh, const char *client_reason,
3810 const char *wire_reason,
3811 int code, int clean_exit)
3815 client_reason = wire_reason;
3817 error = dupprintf("Disconnected: %s", client_reason);
3819 error = dupstr("Disconnected");
3821 if (ssh->version == 1) {
3822 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3824 } else if (ssh->version == 2) {
3825 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3826 ssh2_pkt_adduint32(pktout, code);
3827 ssh2_pkt_addstring(pktout, wire_reason);
3828 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3829 ssh2_pkt_send_noqueue(ssh, pktout);
3832 ssh->close_expected = TRUE;
3833 ssh->clean_exit = clean_exit;
3834 ssh_closing((Plug)ssh, error, 0, 0);
3838 int verify_ssh_manual_host_key(Ssh ssh, const char *fingerprint,
3839 const struct ssh_signkey *ssh2keytype,
3842 if (!conf_get_str_nthstrkey(ssh->conf, CONF_ssh_manual_hostkeys, 0)) {
3843 return -1; /* no manual keys configured */
3848 * The fingerprint string we've been given will have things
3849 * like 'ssh-rsa 2048' at the front of it. Strip those off and
3850 * narrow down to just the colon-separated hex block at the
3851 * end of the string.
3853 const char *p = strrchr(fingerprint, ' ');
3854 fingerprint = p ? p+1 : fingerprint;
3855 /* Quick sanity checks, including making sure it's in lowercase */
3856 assert(strlen(fingerprint) == 16*3 - 1);
3857 assert(fingerprint[2] == ':');
3858 assert(fingerprint[strspn(fingerprint, "0123456789abcdef:")] == 0);
3860 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3862 return 1; /* success */
3867 * Construct the base64-encoded public key blob and see if
3870 unsigned char *binblob;
3872 int binlen, atoms, i;
3873 binblob = ssh2keytype->public_blob(ssh2keydata, &binlen);
3874 atoms = (binlen + 2) / 3;
3875 base64blob = snewn(atoms * 4 + 1, char);
3876 for (i = 0; i < atoms; i++)
3877 base64_encode_atom(binblob + 3*i, binlen - 3*i, base64blob + 4*i);
3878 base64blob[atoms * 4] = '\0';
3880 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3883 return 1; /* success */
3892 * Handle the key exchange and user authentication phases.
3894 static int do_ssh1_login(Ssh ssh, const unsigned char *in, int inlen,
3895 struct Packet *pktin)
3898 unsigned char cookie[8], *ptr;
3899 struct MD5Context md5c;
3900 struct do_ssh1_login_state {
3903 unsigned char *rsabuf;
3904 const unsigned char *keystr1, *keystr2;
3905 unsigned long supported_ciphers_mask, supported_auths_mask;
3906 int tried_publickey, tried_agent;
3907 int tis_auth_refused, ccard_auth_refused;
3908 unsigned char session_id[16];
3910 void *publickey_blob;
3911 int publickey_bloblen;
3912 char *publickey_comment;
3913 int privatekey_available, privatekey_encrypted;
3914 prompts_t *cur_prompt;
3917 unsigned char request[5], *response, *p;
3927 struct RSAKey servkey, hostkey;
3929 crState(do_ssh1_login_state);
3936 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
3937 bombout(("Public key packet not received"));
3941 logevent("Received public keys");
3943 ptr = ssh_pkt_getdata(pktin, 8);
3945 bombout(("SSH-1 public key packet stopped before random cookie"));
3948 memcpy(cookie, ptr, 8);
3950 if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) ||
3951 !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) {
3952 bombout(("Failed to read SSH-1 public keys from public key packet"));
3957 * Log the host key fingerprint.
3961 logevent("Host key fingerprint is:");
3962 strcpy(logmsg, " ");
3963 s->hostkey.comment = NULL;
3964 rsa_fingerprint(logmsg + strlen(logmsg),
3965 sizeof(logmsg) - strlen(logmsg), &s->hostkey);
3969 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3970 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3971 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
3972 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
3973 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
3975 ssh->v1_local_protoflags =
3976 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3977 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
3980 MD5Update(&md5c, s->keystr2, s->hostkey.bytes);
3981 MD5Update(&md5c, s->keystr1, s->servkey.bytes);
3982 MD5Update(&md5c, cookie, 8);
3983 MD5Final(s->session_id, &md5c);
3985 for (i = 0; i < 32; i++)
3986 ssh->session_key[i] = random_byte();
3989 * Verify that the `bits' and `bytes' parameters match.
3991 if (s->hostkey.bits > s->hostkey.bytes * 8 ||
3992 s->servkey.bits > s->servkey.bytes * 8) {
3993 bombout(("SSH-1 public keys were badly formatted"));
3997 s->len = (s->hostkey.bytes > s->servkey.bytes ?
3998 s->hostkey.bytes : s->servkey.bytes);
4000 s->rsabuf = snewn(s->len, unsigned char);
4003 * Verify the host key.
4007 * First format the key into a string.
4009 int len = rsastr_len(&s->hostkey);
4010 char fingerprint[100];
4011 char *keystr = snewn(len, char);
4012 rsastr_fmt(keystr, &s->hostkey);
4013 rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey);
4015 /* First check against manually configured host keys. */
4016 s->dlgret = verify_ssh_manual_host_key(ssh, fingerprint, NULL, NULL);
4017 if (s->dlgret == 0) { /* did not match */
4018 bombout(("Host key did not appear in manually configured list"));
4021 } else if (s->dlgret < 0) { /* none configured; use standard handling */
4022 ssh_set_frozen(ssh, 1);
4023 s->dlgret = verify_ssh_host_key(ssh->frontend,
4024 ssh->savedhost, ssh->savedport,
4025 "rsa", keystr, fingerprint,
4026 ssh_dialog_callback, ssh);
4028 if (s->dlgret < 0) {
4032 bombout(("Unexpected data from server while waiting"
4033 " for user host key response"));
4036 } while (pktin || inlen > 0);
4037 s->dlgret = ssh->user_response;
4039 ssh_set_frozen(ssh, 0);
4041 if (s->dlgret == 0) {
4042 ssh_disconnect(ssh, "User aborted at host key verification",
4051 for (i = 0; i < 32; i++) {
4052 s->rsabuf[i] = ssh->session_key[i];
4054 s->rsabuf[i] ^= s->session_id[i];
4057 if (s->hostkey.bytes > s->servkey.bytes) {
4058 ret = rsaencrypt(s->rsabuf, 32, &s->servkey);
4060 ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey);
4062 ret = rsaencrypt(s->rsabuf, 32, &s->hostkey);
4064 ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey);
4067 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
4071 logevent("Encrypted session key");
4074 int cipher_chosen = 0, warn = 0;
4075 const char *cipher_string = NULL;
4077 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
4078 int next_cipher = conf_get_int_int(ssh->conf,
4079 CONF_ssh_cipherlist, i);
4080 if (next_cipher == CIPHER_WARN) {
4081 /* If/when we choose a cipher, warn about it */
4083 } else if (next_cipher == CIPHER_AES) {
4084 /* XXX Probably don't need to mention this. */
4085 logevent("AES not supported in SSH-1, skipping");
4087 switch (next_cipher) {
4088 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
4089 cipher_string = "3DES"; break;
4090 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
4091 cipher_string = "Blowfish"; break;
4092 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
4093 cipher_string = "single-DES"; break;
4095 if (s->supported_ciphers_mask & (1 << s->cipher_type))
4099 if (!cipher_chosen) {
4100 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
4101 bombout(("Server violates SSH-1 protocol by not "
4102 "supporting 3DES encryption"));
4104 /* shouldn't happen */
4105 bombout(("No supported ciphers found"));
4109 /* Warn about chosen cipher if necessary. */
4111 ssh_set_frozen(ssh, 1);
4112 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
4113 ssh_dialog_callback, ssh);
4114 if (s->dlgret < 0) {
4118 bombout(("Unexpected data from server while waiting"
4119 " for user response"));
4122 } while (pktin || inlen > 0);
4123 s->dlgret = ssh->user_response;
4125 ssh_set_frozen(ssh, 0);
4126 if (s->dlgret == 0) {
4127 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
4134 switch (s->cipher_type) {
4135 case SSH_CIPHER_3DES:
4136 logevent("Using 3DES encryption");
4138 case SSH_CIPHER_DES:
4139 logevent("Using single-DES encryption");
4141 case SSH_CIPHER_BLOWFISH:
4142 logevent("Using Blowfish encryption");
4146 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
4147 PKT_CHAR, s->cipher_type,
4148 PKT_DATA, cookie, 8,
4149 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
4150 PKT_DATA, s->rsabuf, s->len,
4151 PKT_INT, ssh->v1_local_protoflags, PKT_END);
4153 logevent("Trying to enable encryption...");
4157 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
4158 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
4160 ssh->v1_cipher_ctx = ssh->cipher->make_context();
4161 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
4162 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
4164 ssh->crcda_ctx = crcda_make_context();
4165 logevent("Installing CRC compensation attack detector");
4167 if (s->servkey.modulus) {
4168 sfree(s->servkey.modulus);
4169 s->servkey.modulus = NULL;
4171 if (s->servkey.exponent) {
4172 sfree(s->servkey.exponent);
4173 s->servkey.exponent = NULL;
4175 if (s->hostkey.modulus) {
4176 sfree(s->hostkey.modulus);
4177 s->hostkey.modulus = NULL;
4179 if (s->hostkey.exponent) {
4180 sfree(s->hostkey.exponent);
4181 s->hostkey.exponent = NULL;
4185 if (pktin->type != SSH1_SMSG_SUCCESS) {
4186 bombout(("Encryption not successfully enabled"));
4190 logevent("Successfully started encryption");
4192 fflush(stdout); /* FIXME eh? */
4194 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
4195 int ret; /* need not be kept over crReturn */
4196 s->cur_prompt = new_prompts(ssh->frontend);
4197 s->cur_prompt->to_server = TRUE;
4198 s->cur_prompt->name = dupstr("SSH login name");
4199 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
4200 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4203 crWaitUntil(!pktin);
4204 ret = get_userpass_input(s->cur_prompt, in, inlen);
4209 * Failed to get a username. Terminate.
4211 free_prompts(s->cur_prompt);
4212 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
4215 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
4216 free_prompts(s->cur_prompt);
4219 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
4221 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
4223 if (flags & FLAG_INTERACTIVE &&
4224 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
4225 c_write_str(ssh, userlog);
4226 c_write_str(ssh, "\r\n");
4234 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
4235 /* We must not attempt PK auth. Pretend we've already tried it. */
4236 s->tried_publickey = s->tried_agent = 1;
4238 s->tried_publickey = s->tried_agent = 0;
4240 s->tis_auth_refused = s->ccard_auth_refused = 0;
4242 * Load the public half of any configured keyfile for later use.
4244 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4245 if (!filename_is_null(s->keyfile)) {
4247 logeventf(ssh, "Reading key file \"%.150s\"",
4248 filename_to_str(s->keyfile));
4249 keytype = key_type(s->keyfile);
4250 if (keytype == SSH_KEYTYPE_SSH1 ||
4251 keytype == SSH_KEYTYPE_SSH1_PUBLIC) {
4253 if (rsakey_pubblob(s->keyfile,
4254 &s->publickey_blob, &s->publickey_bloblen,
4255 &s->publickey_comment, &error)) {
4256 s->privatekey_available = (keytype == SSH_KEYTYPE_SSH1);
4257 if (!s->privatekey_available)
4258 logeventf(ssh, "Key file contains public key only");
4259 s->privatekey_encrypted = rsakey_encrypted(s->keyfile,
4263 logeventf(ssh, "Unable to load key (%s)", error);
4264 msgbuf = dupprintf("Unable to load key file "
4265 "\"%.150s\" (%s)\r\n",
4266 filename_to_str(s->keyfile),
4268 c_write_str(ssh, msgbuf);
4270 s->publickey_blob = NULL;
4274 logeventf(ssh, "Unable to use this key file (%s)",
4275 key_type_to_str(keytype));
4276 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4278 filename_to_str(s->keyfile),
4279 key_type_to_str(keytype));
4280 c_write_str(ssh, msgbuf);
4282 s->publickey_blob = NULL;
4285 s->publickey_blob = NULL;
4287 while (pktin->type == SSH1_SMSG_FAILURE) {
4288 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
4290 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
4292 * Attempt RSA authentication using Pageant.
4298 logevent("Pageant is running. Requesting keys.");
4300 /* Request the keys held by the agent. */
4301 PUT_32BIT(s->request, 1);
4302 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
4303 if (!agent_query(s->request, 5, &r, &s->responselen,
4304 ssh_agent_callback, ssh)) {
4308 bombout(("Unexpected data from server while waiting"
4309 " for agent response"));
4312 } while (pktin || inlen > 0);
4313 r = ssh->agent_response;
4314 s->responselen = ssh->agent_response_len;
4316 s->response = (unsigned char *) r;
4317 if (s->response && s->responselen >= 5 &&
4318 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
4319 s->p = s->response + 5;
4320 s->nkeys = toint(GET_32BIT(s->p));
4322 logeventf(ssh, "Pageant reported negative key count %d",
4327 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
4328 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4329 unsigned char *pkblob = s->p;
4333 do { /* do while (0) to make breaking easy */
4334 n = ssh1_read_bignum
4335 (s->p, toint(s->responselen-(s->p-s->response)),
4340 n = ssh1_read_bignum
4341 (s->p, toint(s->responselen-(s->p-s->response)),
4346 if (s->responselen - (s->p-s->response) < 4)
4348 s->commentlen = toint(GET_32BIT(s->p));
4350 if (s->commentlen < 0 ||
4351 toint(s->responselen - (s->p-s->response)) <
4354 s->commentp = (char *)s->p;
4355 s->p += s->commentlen;
4359 logevent("Pageant key list packet was truncated");
4363 if (s->publickey_blob) {
4364 if (!memcmp(pkblob, s->publickey_blob,
4365 s->publickey_bloblen)) {
4366 logeventf(ssh, "Pageant key #%d matches "
4367 "configured key file", s->keyi);
4368 s->tried_publickey = 1;
4370 /* Skip non-configured key */
4373 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
4374 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4375 PKT_BIGNUM, s->key.modulus, PKT_END);
4377 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4378 logevent("Key refused");
4381 logevent("Received RSA challenge");
4382 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4383 bombout(("Server's RSA challenge was badly formatted"));
4388 char *agentreq, *q, *ret;
4391 len = 1 + 4; /* message type, bit count */
4392 len += ssh1_bignum_length(s->key.exponent);
4393 len += ssh1_bignum_length(s->key.modulus);
4394 len += ssh1_bignum_length(s->challenge);
4395 len += 16; /* session id */
4396 len += 4; /* response format */
4397 agentreq = snewn(4 + len, char);
4398 PUT_32BIT(agentreq, len);
4400 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
4401 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
4403 q += ssh1_write_bignum(q, s->key.exponent);
4404 q += ssh1_write_bignum(q, s->key.modulus);
4405 q += ssh1_write_bignum(q, s->challenge);
4406 memcpy(q, s->session_id, 16);
4408 PUT_32BIT(q, 1); /* response format */
4409 if (!agent_query(agentreq, len + 4, &vret, &retlen,
4410 ssh_agent_callback, ssh)) {
4415 bombout(("Unexpected data from server"
4416 " while waiting for agent"
4420 } while (pktin || inlen > 0);
4421 vret = ssh->agent_response;
4422 retlen = ssh->agent_response_len;
4427 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
4428 logevent("Sending Pageant's response");
4429 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4430 PKT_DATA, ret + 5, 16,
4434 if (pktin->type == SSH1_SMSG_SUCCESS) {
4436 ("Pageant's response accepted");
4437 if (flags & FLAG_VERBOSE) {
4438 c_write_str(ssh, "Authenticated using"
4440 c_write(ssh, s->commentp,
4442 c_write_str(ssh, "\" from agent\r\n");
4447 ("Pageant's response not accepted");
4450 ("Pageant failed to answer challenge");
4454 logevent("No reply received from Pageant");
4457 freebn(s->key.exponent);
4458 freebn(s->key.modulus);
4459 freebn(s->challenge);
4464 if (s->publickey_blob && !s->tried_publickey)
4465 logevent("Configured key file not in Pageant");
4467 logevent("Failed to get reply from Pageant");
4472 if (s->publickey_blob && s->privatekey_available &&
4473 !s->tried_publickey) {
4475 * Try public key authentication with the specified
4478 int got_passphrase; /* need not be kept over crReturn */
4479 if (flags & FLAG_VERBOSE)
4480 c_write_str(ssh, "Trying public key authentication.\r\n");
4481 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4482 logeventf(ssh, "Trying public key \"%s\"",
4483 filename_to_str(s->keyfile));
4484 s->tried_publickey = 1;
4485 got_passphrase = FALSE;
4486 while (!got_passphrase) {
4488 * Get a passphrase, if necessary.
4490 char *passphrase = NULL; /* only written after crReturn */
4492 if (!s->privatekey_encrypted) {
4493 if (flags & FLAG_VERBOSE)
4494 c_write_str(ssh, "No passphrase required.\r\n");
4497 int ret; /* need not be kept over crReturn */
4498 s->cur_prompt = new_prompts(ssh->frontend);
4499 s->cur_prompt->to_server = FALSE;
4500 s->cur_prompt->name = dupstr("SSH key passphrase");
4501 add_prompt(s->cur_prompt,
4502 dupprintf("Passphrase for key \"%.100s\": ",
4503 s->publickey_comment), FALSE);
4504 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4507 crWaitUntil(!pktin);
4508 ret = get_userpass_input(s->cur_prompt, in, inlen);
4512 /* Failed to get a passphrase. Terminate. */
4513 free_prompts(s->cur_prompt);
4514 ssh_disconnect(ssh, NULL, "Unable to authenticate",
4518 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
4519 free_prompts(s->cur_prompt);
4522 * Try decrypting key with passphrase.
4524 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4525 ret = loadrsakey(s->keyfile, &s->key, passphrase,
4528 smemclr(passphrase, strlen(passphrase));
4532 /* Correct passphrase. */
4533 got_passphrase = TRUE;
4534 } else if (ret == 0) {
4535 c_write_str(ssh, "Couldn't load private key from ");
4536 c_write_str(ssh, filename_to_str(s->keyfile));
4537 c_write_str(ssh, " (");
4538 c_write_str(ssh, error);
4539 c_write_str(ssh, ").\r\n");
4540 got_passphrase = FALSE;
4541 break; /* go and try something else */
4542 } else if (ret == -1) {
4543 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
4544 got_passphrase = FALSE;
4547 assert(0 && "unexpected return from loadrsakey()");
4548 got_passphrase = FALSE; /* placate optimisers */
4552 if (got_passphrase) {
4555 * Send a public key attempt.
4557 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4558 PKT_BIGNUM, s->key.modulus, PKT_END);
4561 if (pktin->type == SSH1_SMSG_FAILURE) {
4562 c_write_str(ssh, "Server refused our public key.\r\n");
4563 continue; /* go and try something else */
4565 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4566 bombout(("Bizarre response to offer of public key"));
4572 unsigned char buffer[32];
4573 Bignum challenge, response;
4575 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4576 bombout(("Server's RSA challenge was badly formatted"));
4579 response = rsadecrypt(challenge, &s->key);
4580 freebn(s->key.private_exponent);/* burn the evidence */
4582 for (i = 0; i < 32; i++) {
4583 buffer[i] = bignum_byte(response, 31 - i);
4587 MD5Update(&md5c, buffer, 32);
4588 MD5Update(&md5c, s->session_id, 16);
4589 MD5Final(buffer, &md5c);
4591 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4592 PKT_DATA, buffer, 16, PKT_END);
4599 if (pktin->type == SSH1_SMSG_FAILURE) {
4600 if (flags & FLAG_VERBOSE)
4601 c_write_str(ssh, "Failed to authenticate with"
4602 " our public key.\r\n");
4603 continue; /* go and try something else */
4604 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4605 bombout(("Bizarre response to RSA authentication response"));
4609 break; /* we're through! */
4615 * Otherwise, try various forms of password-like authentication.
4617 s->cur_prompt = new_prompts(ssh->frontend);
4619 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4620 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
4621 !s->tis_auth_refused) {
4622 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
4623 logevent("Requested TIS authentication");
4624 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
4626 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
4627 logevent("TIS authentication declined");
4628 if (flags & FLAG_INTERACTIVE)
4629 c_write_str(ssh, "TIS authentication refused.\r\n");
4630 s->tis_auth_refused = 1;
4635 char *instr_suf, *prompt;
4637 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4639 bombout(("TIS challenge packet was badly formed"));
4642 logevent("Received TIS challenge");
4643 s->cur_prompt->to_server = TRUE;
4644 s->cur_prompt->name = dupstr("SSH TIS authentication");
4645 /* Prompt heuristic comes from OpenSSH */
4646 if (memchr(challenge, '\n', challengelen)) {
4647 instr_suf = dupstr("");
4648 prompt = dupprintf("%.*s", challengelen, challenge);
4650 instr_suf = dupprintf("%.*s", challengelen, challenge);
4651 prompt = dupstr("Response: ");
4653 s->cur_prompt->instruction =
4654 dupprintf("Using TIS authentication.%s%s",
4655 (*instr_suf) ? "\n" : "",
4657 s->cur_prompt->instr_reqd = TRUE;
4658 add_prompt(s->cur_prompt, prompt, FALSE);
4662 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4663 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
4664 !s->ccard_auth_refused) {
4665 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
4666 logevent("Requested CryptoCard authentication");
4667 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
4669 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
4670 logevent("CryptoCard authentication declined");
4671 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4672 s->ccard_auth_refused = 1;
4677 char *instr_suf, *prompt;
4679 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4681 bombout(("CryptoCard challenge packet was badly formed"));
4684 logevent("Received CryptoCard challenge");
4685 s->cur_prompt->to_server = TRUE;
4686 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4687 s->cur_prompt->name_reqd = FALSE;
4688 /* Prompt heuristic comes from OpenSSH */
4689 if (memchr(challenge, '\n', challengelen)) {
4690 instr_suf = dupstr("");
4691 prompt = dupprintf("%.*s", challengelen, challenge);
4693 instr_suf = dupprintf("%.*s", challengelen, challenge);
4694 prompt = dupstr("Response: ");
4696 s->cur_prompt->instruction =
4697 dupprintf("Using CryptoCard authentication.%s%s",
4698 (*instr_suf) ? "\n" : "",
4700 s->cur_prompt->instr_reqd = TRUE;
4701 add_prompt(s->cur_prompt, prompt, FALSE);
4705 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4706 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4707 bombout(("No supported authentication methods available"));
4710 s->cur_prompt->to_server = TRUE;
4711 s->cur_prompt->name = dupstr("SSH password");
4712 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4713 ssh->username, ssh->savedhost),
4718 * Show password prompt, having first obtained it via a TIS
4719 * or CryptoCard exchange if we're doing TIS or CryptoCard
4723 int ret; /* need not be kept over crReturn */
4724 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4727 crWaitUntil(!pktin);
4728 ret = get_userpass_input(s->cur_prompt, in, inlen);
4733 * Failed to get a password (for example
4734 * because one was supplied on the command line
4735 * which has already failed to work). Terminate.
4737 free_prompts(s->cur_prompt);
4738 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4743 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4745 * Defence against traffic analysis: we send a
4746 * whole bunch of packets containing strings of
4747 * different lengths. One of these strings is the
4748 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4749 * The others are all random data in
4750 * SSH1_MSG_IGNORE packets. This way a passive
4751 * listener can't tell which is the password, and
4752 * hence can't deduce the password length.
4754 * Anybody with a password length greater than 16
4755 * bytes is going to have enough entropy in their
4756 * password that a listener won't find it _that_
4757 * much help to know how long it is. So what we'll
4760 * - if password length < 16, we send 15 packets
4761 * containing string lengths 1 through 15
4763 * - otherwise, we let N be the nearest multiple
4764 * of 8 below the password length, and send 8
4765 * packets containing string lengths N through
4766 * N+7. This won't obscure the order of
4767 * magnitude of the password length, but it will
4768 * introduce a bit of extra uncertainty.
4770 * A few servers can't deal with SSH1_MSG_IGNORE, at
4771 * least in this context. For these servers, we need
4772 * an alternative defence. We make use of the fact
4773 * that the password is interpreted as a C string:
4774 * so we can append a NUL, then some random data.
4776 * A few servers can deal with neither SSH1_MSG_IGNORE
4777 * here _nor_ a padded password string.
4778 * For these servers we are left with no defences
4779 * against password length sniffing.
4781 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4782 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4784 * The server can deal with SSH1_MSG_IGNORE, so
4785 * we can use the primary defence.
4787 int bottom, top, pwlen, i;
4790 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4792 bottom = 0; /* zero length passwords are OK! :-) */
4795 bottom = pwlen & ~7;
4799 assert(pwlen >= bottom && pwlen <= top);
4801 randomstr = snewn(top + 1, char);
4803 for (i = bottom; i <= top; i++) {
4805 defer_packet(ssh, s->pwpkt_type,
4806 PKT_STR,s->cur_prompt->prompts[0]->result,
4809 for (j = 0; j < i; j++) {
4811 randomstr[j] = random_byte();
4812 } while (randomstr[j] == '\0');
4814 randomstr[i] = '\0';
4815 defer_packet(ssh, SSH1_MSG_IGNORE,
4816 PKT_STR, randomstr, PKT_END);
4819 logevent("Sending password with camouflage packets");
4820 ssh_pkt_defersend(ssh);
4823 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4825 * The server can't deal with SSH1_MSG_IGNORE
4826 * but can deal with padded passwords, so we
4827 * can use the secondary defence.
4833 len = strlen(s->cur_prompt->prompts[0]->result);
4834 if (len < sizeof(string)) {
4836 strcpy(string, s->cur_prompt->prompts[0]->result);
4837 len++; /* cover the zero byte */
4838 while (len < sizeof(string)) {
4839 string[len++] = (char) random_byte();
4842 ss = s->cur_prompt->prompts[0]->result;
4844 logevent("Sending length-padded password");
4845 send_packet(ssh, s->pwpkt_type,
4846 PKT_INT, len, PKT_DATA, ss, len,
4850 * The server is believed unable to cope with
4851 * any of our password camouflage methods.
4854 len = strlen(s->cur_prompt->prompts[0]->result);
4855 logevent("Sending unpadded password");
4856 send_packet(ssh, s->pwpkt_type,
4858 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4862 send_packet(ssh, s->pwpkt_type,
4863 PKT_STR, s->cur_prompt->prompts[0]->result,
4866 logevent("Sent password");
4867 free_prompts(s->cur_prompt);
4869 if (pktin->type == SSH1_SMSG_FAILURE) {
4870 if (flags & FLAG_VERBOSE)
4871 c_write_str(ssh, "Access denied\r\n");
4872 logevent("Authentication refused");
4873 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4874 bombout(("Strange packet received, type %d", pktin->type));
4880 if (s->publickey_blob) {
4881 sfree(s->publickey_blob);
4882 sfree(s->publickey_comment);
4885 logevent("Authentication successful");
4890 static void ssh_channel_try_eof(struct ssh_channel *c)
4893 assert(c->pending_eof); /* precondition for calling us */
4895 return; /* can't close: not even opened yet */
4896 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4897 return; /* can't send EOF: pending outgoing data */
4899 c->pending_eof = FALSE; /* we're about to send it */
4900 if (ssh->version == 1) {
4901 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4903 c->closes |= CLOSES_SENT_EOF;
4905 struct Packet *pktout;
4906 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4907 ssh2_pkt_adduint32(pktout, c->remoteid);
4908 ssh2_pkt_send(ssh, pktout);
4909 c->closes |= CLOSES_SENT_EOF;
4910 ssh2_channel_check_close(c);
4914 Conf *sshfwd_get_conf(struct ssh_channel *c)
4920 void sshfwd_write_eof(struct ssh_channel *c)
4924 if (ssh->state == SSH_STATE_CLOSED)
4927 if (c->closes & CLOSES_SENT_EOF)
4930 c->pending_eof = TRUE;
4931 ssh_channel_try_eof(c);
4934 void sshfwd_unclean_close(struct ssh_channel *c, const char *err)
4938 if (ssh->state == SSH_STATE_CLOSED)
4943 x11_close(c->u.x11.xconn);
4944 logeventf(ssh, "Forwarded X11 connection terminated due to local "
4948 case CHAN_SOCKDATA_DORMANT:
4949 pfd_close(c->u.pfd.pf);
4950 logeventf(ssh, "Forwarded port closed due to local error: %s", err);
4953 c->type = CHAN_ZOMBIE;
4954 c->pending_eof = FALSE; /* this will confuse a zombie channel */
4956 ssh2_channel_check_close(c);
4959 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
4963 if (ssh->state == SSH_STATE_CLOSED)
4966 if (ssh->version == 1) {
4967 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
4968 PKT_INT, c->remoteid,
4969 PKT_INT, len, PKT_DATA, buf, len,
4972 * In SSH-1 we can return 0 here - implying that forwarded
4973 * connections are never individually throttled - because
4974 * the only circumstance that can cause throttling will be
4975 * the whole SSH connection backing up, in which case
4976 * _everything_ will be throttled as a whole.
4980 ssh2_add_channel_data(c, buf, len);
4981 return ssh2_try_send(c);
4985 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4990 if (ssh->state == SSH_STATE_CLOSED)
4993 if (ssh->version == 1) {
4994 buflimit = SSH1_BUFFER_LIMIT;
4996 buflimit = c->v.v2.locmaxwin;
4997 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
4999 if (c->throttling_conn && bufsize <= buflimit) {
5000 c->throttling_conn = 0;
5001 ssh_throttle_conn(ssh, -1);
5005 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
5007 struct queued_handler *qh = ssh->qhead;
5011 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
5014 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
5015 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
5018 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
5019 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
5023 ssh->qhead = qh->next;
5025 if (ssh->qhead->msg1 > 0) {
5026 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
5027 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
5029 if (ssh->qhead->msg2 > 0) {
5030 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
5031 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
5034 ssh->qhead = ssh->qtail = NULL;
5037 qh->handler(ssh, pktin, qh->ctx);
5042 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
5043 chandler_fn_t handler, void *ctx)
5045 struct queued_handler *qh;
5047 qh = snew(struct queued_handler);
5050 qh->handler = handler;
5054 if (ssh->qtail == NULL) {
5058 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
5059 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
5062 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
5063 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
5066 ssh->qtail->next = qh;
5071 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
5073 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
5075 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
5076 SSH2_MSG_REQUEST_SUCCESS)) {
5077 logeventf(ssh, "Remote port forwarding from %s enabled",
5080 logeventf(ssh, "Remote port forwarding from %s refused",
5083 rpf = del234(ssh->rportfwds, pf);
5085 pf->pfrec->remote = NULL;
5090 int ssh_alloc_sharing_rportfwd(Ssh ssh, const char *shost, int sport,
5093 struct ssh_rportfwd *pf = snew(struct ssh_rportfwd);
5096 pf->share_ctx = share_ctx;
5097 pf->shost = dupstr(shost);
5099 pf->sportdesc = NULL;
5100 if (!ssh->rportfwds) {
5101 assert(ssh->version == 2);
5102 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5104 if (add234(ssh->rportfwds, pf) != pf) {
5112 static void ssh_sharing_global_request_response(Ssh ssh, struct Packet *pktin,
5115 share_got_pkt_from_server(ctx, pktin->type,
5116 pktin->body, pktin->length);
5119 void ssh_sharing_queue_global_request(Ssh ssh, void *share_ctx)
5121 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, SSH2_MSG_REQUEST_FAILURE,
5122 ssh_sharing_global_request_response, share_ctx);
5125 static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
5127 struct ssh_portfwd *epf;
5131 if (!ssh->portfwds) {
5132 ssh->portfwds = newtree234(ssh_portcmp);
5135 * Go through the existing port forwardings and tag them
5136 * with status==DESTROY. Any that we want to keep will be
5137 * re-enabled (status==KEEP) as we go through the
5138 * configuration and find out which bits are the same as
5141 struct ssh_portfwd *epf;
5143 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5144 epf->status = DESTROY;
5147 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
5149 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
5150 char *kp, *kp2, *vp, *vp2;
5151 char address_family, type;
5152 int sport,dport,sserv,dserv;
5153 char *sports, *dports, *saddr, *host;
5157 address_family = 'A';
5159 if (*kp == 'A' || *kp == '4' || *kp == '6')
5160 address_family = *kp++;
5161 if (*kp == 'L' || *kp == 'R')
5164 if ((kp2 = host_strchr(kp, ':')) != NULL) {
5166 * There's a colon in the middle of the source port
5167 * string, which means that the part before it is
5168 * actually a source address.
5170 char *saddr_tmp = dupprintf("%.*s", (int)(kp2 - kp), kp);
5171 saddr = host_strduptrim(saddr_tmp);
5178 sport = atoi(sports);
5182 sport = net_service_lookup(sports);
5184 logeventf(ssh, "Service lookup failed for source"
5185 " port \"%s\"", sports);
5189 if (type == 'L' && !strcmp(val, "D")) {
5190 /* dynamic forwarding */
5197 /* ordinary forwarding */
5199 vp2 = vp + host_strcspn(vp, ":");
5200 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
5204 dport = atoi(dports);
5208 dport = net_service_lookup(dports);
5210 logeventf(ssh, "Service lookup failed for destination"
5211 " port \"%s\"", dports);
5216 if (sport && dport) {
5217 /* Set up a description of the source port. */
5218 struct ssh_portfwd *pfrec, *epfrec;
5220 pfrec = snew(struct ssh_portfwd);
5222 pfrec->saddr = saddr;
5223 pfrec->sserv = sserv ? dupstr(sports) : NULL;
5224 pfrec->sport = sport;
5225 pfrec->daddr = host;
5226 pfrec->dserv = dserv ? dupstr(dports) : NULL;
5227 pfrec->dport = dport;
5228 pfrec->local = NULL;
5229 pfrec->remote = NULL;
5230 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
5231 address_family == '6' ? ADDRTYPE_IPV6 :
5234 epfrec = add234(ssh->portfwds, pfrec);
5235 if (epfrec != pfrec) {
5236 if (epfrec->status == DESTROY) {
5238 * We already have a port forwarding up and running
5239 * with precisely these parameters. Hence, no need
5240 * to do anything; simply re-tag the existing one
5243 epfrec->status = KEEP;
5246 * Anything else indicates that there was a duplicate
5247 * in our input, which we'll silently ignore.
5249 free_portfwd(pfrec);
5251 pfrec->status = CREATE;
5260 * Now go through and destroy any port forwardings which were
5263 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5264 if (epf->status == DESTROY) {
5267 message = dupprintf("%s port forwarding from %s%s%d",
5268 epf->type == 'L' ? "local" :
5269 epf->type == 'R' ? "remote" : "dynamic",
5270 epf->saddr ? epf->saddr : "",
5271 epf->saddr ? ":" : "",
5274 if (epf->type != 'D') {
5275 char *msg2 = dupprintf("%s to %s:%d", message,
5276 epf->daddr, epf->dport);
5281 logeventf(ssh, "Cancelling %s", message);
5284 /* epf->remote or epf->local may be NULL if setting up a
5285 * forwarding failed. */
5287 struct ssh_rportfwd *rpf = epf->remote;
5288 struct Packet *pktout;
5291 * Cancel the port forwarding at the server
5294 if (ssh->version == 1) {
5296 * We cannot cancel listening ports on the
5297 * server side in SSH-1! There's no message
5298 * to support it. Instead, we simply remove
5299 * the rportfwd record from the local end
5300 * so that any connections the server tries
5301 * to make on it are rejected.
5304 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5305 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
5306 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
5308 ssh2_pkt_addstring(pktout, epf->saddr);
5309 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5310 /* XXX: rport_acceptall may not represent
5311 * what was used to open the original connection,
5312 * since it's reconfigurable. */
5313 ssh2_pkt_addstring(pktout, "");
5315 ssh2_pkt_addstring(pktout, "localhost");
5317 ssh2_pkt_adduint32(pktout, epf->sport);
5318 ssh2_pkt_send(ssh, pktout);
5321 del234(ssh->rportfwds, rpf);
5323 } else if (epf->local) {
5324 pfl_terminate(epf->local);
5327 delpos234(ssh->portfwds, i);
5329 i--; /* so we don't skip one in the list */
5333 * And finally, set up any new port forwardings (status==CREATE).
5335 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5336 if (epf->status == CREATE) {
5337 char *sportdesc, *dportdesc;
5338 sportdesc = dupprintf("%s%s%s%s%d%s",
5339 epf->saddr ? epf->saddr : "",
5340 epf->saddr ? ":" : "",
5341 epf->sserv ? epf->sserv : "",
5342 epf->sserv ? "(" : "",
5344 epf->sserv ? ")" : "");
5345 if (epf->type == 'D') {
5348 dportdesc = dupprintf("%s:%s%s%d%s",
5350 epf->dserv ? epf->dserv : "",
5351 epf->dserv ? "(" : "",
5353 epf->dserv ? ")" : "");
5356 if (epf->type == 'L') {
5357 char *err = pfl_listen(epf->daddr, epf->dport,
5358 epf->saddr, epf->sport,
5359 ssh, conf, &epf->local,
5360 epf->addressfamily);
5362 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
5363 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5364 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5365 sportdesc, dportdesc,
5366 err ? " failed: " : "", err ? err : "");
5369 } else if (epf->type == 'D') {
5370 char *err = pfl_listen(NULL, -1, epf->saddr, epf->sport,
5371 ssh, conf, &epf->local,
5372 epf->addressfamily);
5374 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
5375 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5376 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5378 err ? " failed: " : "", err ? err : "");
5383 struct ssh_rportfwd *pf;
5386 * Ensure the remote port forwardings tree exists.
5388 if (!ssh->rportfwds) {
5389 if (ssh->version == 1)
5390 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
5392 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5395 pf = snew(struct ssh_rportfwd);
5396 pf->share_ctx = NULL;
5397 pf->dhost = dupstr(epf->daddr);
5398 pf->dport = epf->dport;
5400 pf->shost = dupstr(epf->saddr);
5401 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5402 pf->shost = dupstr("");
5404 pf->shost = dupstr("localhost");
5406 pf->sport = epf->sport;
5407 if (add234(ssh->rportfwds, pf) != pf) {
5408 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
5409 epf->daddr, epf->dport);
5412 logeventf(ssh, "Requesting remote port %s"
5413 " forward to %s", sportdesc, dportdesc);
5415 pf->sportdesc = sportdesc;
5420 if (ssh->version == 1) {
5421 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
5422 PKT_INT, epf->sport,
5423 PKT_STR, epf->daddr,
5424 PKT_INT, epf->dport,
5426 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
5428 ssh_rportfwd_succfail, pf);
5430 struct Packet *pktout;
5431 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5432 ssh2_pkt_addstring(pktout, "tcpip-forward");
5433 ssh2_pkt_addbool(pktout, 1);/* want reply */
5434 ssh2_pkt_addstring(pktout, pf->shost);
5435 ssh2_pkt_adduint32(pktout, pf->sport);
5436 ssh2_pkt_send(ssh, pktout);
5438 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
5439 SSH2_MSG_REQUEST_FAILURE,
5440 ssh_rportfwd_succfail, pf);
5449 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
5452 int stringlen, bufsize;
5454 ssh_pkt_getstring(pktin, &string, &stringlen);
5455 if (string == NULL) {
5456 bombout(("Incoming terminal data packet was badly formed"));
5460 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
5462 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
5463 ssh->v1_stdout_throttling = 1;
5464 ssh_throttle_conn(ssh, +1);
5468 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
5470 /* Remote side is trying to open a channel to talk to our
5471 * X-Server. Give them back a local channel number. */
5472 struct ssh_channel *c;
5473 int remoteid = ssh_pkt_getuint32(pktin);
5475 logevent("Received X11 connect request");
5476 /* Refuse if X11 forwarding is disabled. */
5477 if (!ssh->X11_fwd_enabled) {
5478 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5479 PKT_INT, remoteid, PKT_END);
5480 logevent("Rejected X11 connect request");
5482 c = snew(struct ssh_channel);
5485 c->u.x11.xconn = x11_init(ssh->x11authtree, c, NULL, -1);
5486 c->remoteid = remoteid;
5487 c->halfopen = FALSE;
5488 c->localid = alloc_channel_id(ssh);
5490 c->pending_eof = FALSE;
5491 c->throttling_conn = 0;
5492 c->type = CHAN_X11; /* identify channel type */
5493 add234(ssh->channels, c);
5494 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5495 PKT_INT, c->remoteid, PKT_INT,
5496 c->localid, PKT_END);
5497 logevent("Opened X11 forward channel");
5501 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
5503 /* Remote side is trying to open a channel to talk to our
5504 * agent. Give them back a local channel number. */
5505 struct ssh_channel *c;
5506 int remoteid = ssh_pkt_getuint32(pktin);
5508 /* Refuse if agent forwarding is disabled. */
5509 if (!ssh->agentfwd_enabled) {
5510 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5511 PKT_INT, remoteid, PKT_END);
5513 c = snew(struct ssh_channel);
5515 c->remoteid = remoteid;
5516 c->halfopen = FALSE;
5517 c->localid = alloc_channel_id(ssh);
5519 c->pending_eof = FALSE;
5520 c->throttling_conn = 0;
5521 c->type = CHAN_AGENT; /* identify channel type */
5522 c->u.a.lensofar = 0;
5523 c->u.a.message = NULL;
5524 c->u.a.outstanding_requests = 0;
5525 add234(ssh->channels, c);
5526 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5527 PKT_INT, c->remoteid, PKT_INT, c->localid,
5532 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
5534 /* Remote side is trying to open a channel to talk to a
5535 * forwarded port. Give them back a local channel number. */
5536 struct ssh_rportfwd pf, *pfp;
5542 remoteid = ssh_pkt_getuint32(pktin);
5543 ssh_pkt_getstring(pktin, &host, &hostsize);
5544 port = ssh_pkt_getuint32(pktin);
5546 pf.dhost = dupprintf("%.*s", hostsize, host);
5548 pfp = find234(ssh->rportfwds, &pf, NULL);
5551 logeventf(ssh, "Rejected remote port open request for %s:%d",
5553 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5554 PKT_INT, remoteid, PKT_END);
5556 struct ssh_channel *c = snew(struct ssh_channel);
5559 logeventf(ssh, "Received remote port open request for %s:%d",
5561 err = pfd_connect(&c->u.pfd.pf, pf.dhost, port,
5562 c, ssh->conf, pfp->pfrec->addressfamily);
5564 logeventf(ssh, "Port open failed: %s", err);
5567 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5568 PKT_INT, remoteid, PKT_END);
5570 c->remoteid = remoteid;
5571 c->halfopen = FALSE;
5572 c->localid = alloc_channel_id(ssh);
5574 c->pending_eof = FALSE;
5575 c->throttling_conn = 0;
5576 c->type = CHAN_SOCKDATA; /* identify channel type */
5577 add234(ssh->channels, c);
5578 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5579 PKT_INT, c->remoteid, PKT_INT,
5580 c->localid, PKT_END);
5581 logevent("Forwarded port opened successfully");
5588 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5590 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5591 unsigned int localid = ssh_pkt_getuint32(pktin);
5592 struct ssh_channel *c;
5594 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5595 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5596 c->remoteid = localid;
5597 c->halfopen = FALSE;
5598 c->type = CHAN_SOCKDATA;
5599 c->throttling_conn = 0;
5600 pfd_confirm(c->u.pfd.pf);
5603 if (c && c->pending_eof) {
5605 * We have a pending close on this channel,
5606 * which we decided on before the server acked
5607 * the channel open. So now we know the
5608 * remoteid, we can close it again.
5610 ssh_channel_try_eof(c);
5614 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5616 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5617 struct ssh_channel *c;
5619 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5620 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5621 logevent("Forwarded connection refused by server");
5622 pfd_close(c->u.pfd.pf);
5623 del234(ssh->channels, c);
5628 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
5630 /* Remote side closes a channel. */
5631 unsigned i = ssh_pkt_getuint32(pktin);
5632 struct ssh_channel *c;
5633 c = find234(ssh->channels, &i, ssh_channelfind);
5634 if (c && !c->halfopen) {
5636 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
5637 !(c->closes & CLOSES_RCVD_EOF)) {
5639 * Received CHANNEL_CLOSE, which we translate into
5642 int send_close = FALSE;
5644 c->closes |= CLOSES_RCVD_EOF;
5649 x11_send_eof(c->u.x11.xconn);
5655 pfd_send_eof(c->u.pfd.pf);
5664 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
5665 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
5667 c->closes |= CLOSES_SENT_EOF;
5671 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
5672 !(c->closes & CLOSES_RCVD_CLOSE)) {
5674 if (!(c->closes & CLOSES_SENT_EOF)) {
5675 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
5676 " for which we never sent CHANNEL_CLOSE\n", i));
5679 c->closes |= CLOSES_RCVD_CLOSE;
5682 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
5683 !(c->closes & CLOSES_SENT_CLOSE)) {
5684 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
5685 PKT_INT, c->remoteid, PKT_END);
5686 c->closes |= CLOSES_SENT_CLOSE;
5689 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5690 ssh_channel_destroy(c);
5692 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5693 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
5694 "_CONFIRMATION", c ? "half-open" : "nonexistent",
5699 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5701 /* Data sent down one of our channels. */
5702 int i = ssh_pkt_getuint32(pktin);
5705 struct ssh_channel *c;
5707 ssh_pkt_getstring(pktin, &p, &len);
5709 c = find234(ssh->channels, &i, ssh_channelfind);
5714 bufsize = x11_send(c->u.x11.xconn, p, len);
5717 bufsize = pfd_send(c->u.pfd.pf, p, len);
5720 /* Data for an agent message. Buffer it. */
5722 if (c->u.a.lensofar < 4) {
5723 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
5724 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
5728 c->u.a.lensofar += l;
5730 if (c->u.a.lensofar == 4) {
5732 4 + GET_32BIT(c->u.a.msglen);
5733 c->u.a.message = snewn(c->u.a.totallen,
5735 memcpy(c->u.a.message, c->u.a.msglen, 4);
5737 if (c->u.a.lensofar >= 4 && len > 0) {
5739 min(c->u.a.totallen - c->u.a.lensofar,
5741 memcpy(c->u.a.message + c->u.a.lensofar, p,
5745 c->u.a.lensofar += l;
5747 if (c->u.a.lensofar == c->u.a.totallen) {
5750 c->u.a.outstanding_requests++;
5751 if (agent_query(c->u.a.message,
5754 ssh_agentf_callback, c))
5755 ssh_agentf_callback(c, reply, replylen);
5756 sfree(c->u.a.message);
5757 c->u.a.lensofar = 0;
5760 bufsize = 0; /* agent channels never back up */
5763 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5764 c->throttling_conn = 1;
5765 ssh_throttle_conn(ssh, +1);
5770 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5772 ssh->exitcode = ssh_pkt_getuint32(pktin);
5773 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5774 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5776 * In case `helpful' firewalls or proxies tack
5777 * extra human-readable text on the end of the
5778 * session which we might mistake for another
5779 * encrypted packet, we close the session once
5780 * we've sent EXIT_CONFIRMATION.
5782 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5785 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5786 static void ssh1_send_ttymode(void *data, char *mode, char *val)
5788 struct Packet *pktout = (struct Packet *)data;
5790 unsigned int arg = 0;
5791 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5792 if (i == lenof(ssh_ttymodes)) return;
5793 switch (ssh_ttymodes[i].type) {
5795 arg = ssh_tty_parse_specchar(val);
5798 arg = ssh_tty_parse_boolean(val);
5801 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5802 ssh2_pkt_addbyte(pktout, arg);
5805 int ssh_agent_forwarding_permitted(Ssh ssh)
5807 return conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists();
5810 static void do_ssh1_connection(Ssh ssh, const unsigned char *in, int inlen,
5811 struct Packet *pktin)
5813 crBegin(ssh->do_ssh1_connection_crstate);
5815 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5816 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5817 ssh1_smsg_stdout_stderr_data;
5819 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5820 ssh1_msg_channel_open_confirmation;
5821 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5822 ssh1_msg_channel_open_failure;
5823 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5824 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5825 ssh1_msg_channel_close;
5826 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5827 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5829 if (ssh_agent_forwarding_permitted(ssh)) {
5830 logevent("Requesting agent forwarding");
5831 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5835 if (pktin->type != SSH1_SMSG_SUCCESS
5836 && pktin->type != SSH1_SMSG_FAILURE) {
5837 bombout(("Protocol confusion"));
5839 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5840 logevent("Agent forwarding refused");
5842 logevent("Agent forwarding enabled");
5843 ssh->agentfwd_enabled = TRUE;
5844 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5848 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
5850 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5852 if (!ssh->x11disp) {
5853 /* FIXME: return an error message from x11_setup_display */
5854 logevent("X11 forwarding not enabled: unable to"
5855 " initialise X display");
5857 ssh->x11auth = x11_invent_fake_auth
5858 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
5859 ssh->x11auth->disp = ssh->x11disp;
5861 logevent("Requesting X11 forwarding");
5862 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5863 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5864 PKT_STR, ssh->x11auth->protoname,
5865 PKT_STR, ssh->x11auth->datastring,
5866 PKT_INT, ssh->x11disp->screennum,
5869 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5870 PKT_STR, ssh->x11auth->protoname,
5871 PKT_STR, ssh->x11auth->datastring,
5877 if (pktin->type != SSH1_SMSG_SUCCESS
5878 && pktin->type != SSH1_SMSG_FAILURE) {
5879 bombout(("Protocol confusion"));
5881 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5882 logevent("X11 forwarding refused");
5884 logevent("X11 forwarding enabled");
5885 ssh->X11_fwd_enabled = TRUE;
5886 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5891 ssh_setup_portfwd(ssh, ssh->conf);
5892 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5894 if (!conf_get_int(ssh->conf, CONF_nopty)) {
5896 /* Unpick the terminal-speed string. */
5897 /* XXX perhaps we should allow no speeds to be sent. */
5898 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5899 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
5900 /* Send the pty request. */
5901 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5902 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
5903 ssh_pkt_adduint32(pkt, ssh->term_height);
5904 ssh_pkt_adduint32(pkt, ssh->term_width);
5905 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5906 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5907 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
5908 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5909 ssh_pkt_adduint32(pkt, ssh->ispeed);
5910 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5911 ssh_pkt_adduint32(pkt, ssh->ospeed);
5912 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5914 ssh->state = SSH_STATE_INTERMED;
5918 if (pktin->type != SSH1_SMSG_SUCCESS
5919 && pktin->type != SSH1_SMSG_FAILURE) {
5920 bombout(("Protocol confusion"));
5922 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5923 c_write_str(ssh, "Server refused to allocate pty\r\n");
5924 ssh->editing = ssh->echoing = 1;
5926 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5927 ssh->ospeed, ssh->ispeed);
5928 ssh->got_pty = TRUE;
5931 ssh->editing = ssh->echoing = 1;
5934 if (conf_get_int(ssh->conf, CONF_compression)) {
5935 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5939 if (pktin->type != SSH1_SMSG_SUCCESS
5940 && pktin->type != SSH1_SMSG_FAILURE) {
5941 bombout(("Protocol confusion"));
5943 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5944 c_write_str(ssh, "Server refused to compress\r\n");
5946 logevent("Started compression");
5947 ssh->v1_compressing = TRUE;
5948 ssh->cs_comp_ctx = zlib_compress_init();
5949 logevent("Initialised zlib (RFC1950) compression");
5950 ssh->sc_comp_ctx = zlib_decompress_init();
5951 logevent("Initialised zlib (RFC1950) decompression");
5955 * Start the shell or command.
5957 * Special case: if the first-choice command is an SSH-2
5958 * subsystem (hence not usable here) and the second choice
5959 * exists, we fall straight back to that.
5962 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
5964 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
5965 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
5966 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
5967 ssh->fallback_cmd = TRUE;
5970 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
5972 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
5973 logevent("Started session");
5976 ssh->state = SSH_STATE_SESSION;
5977 if (ssh->size_needed)
5978 ssh_size(ssh, ssh->term_width, ssh->term_height);
5979 if (ssh->eof_needed)
5980 ssh_special(ssh, TS_EOF);
5983 ldisc_echoedit_update(ssh->ldisc); /* cause ldisc to notice changes */
5985 ssh->channels = newtree234(ssh_channelcmp);
5989 * By this point, most incoming packets are already being
5990 * handled by the dispatch table, and we need only pay
5991 * attention to the unusual ones.
5996 if (pktin->type == SSH1_SMSG_SUCCESS) {
5997 /* may be from EXEC_SHELL on some servers */
5998 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5999 /* may be from EXEC_SHELL on some servers
6000 * if no pty is available or in other odd cases. Ignore */
6002 bombout(("Strange packet received: type %d", pktin->type));
6007 int len = min(inlen, 512);
6008 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
6009 PKT_INT, len, PKT_DATA, in, len,
6021 * Handle the top-level SSH-2 protocol.
6023 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
6028 ssh_pkt_getstring(pktin, &msg, &msglen);
6029 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
6032 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
6034 /* log reason code in disconnect message */
6038 ssh_pkt_getstring(pktin, &msg, &msglen);
6039 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
6042 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
6044 /* Do nothing, because we're ignoring it! Duhh. */
6047 static void ssh1_protocol_setup(Ssh ssh)
6052 * Most messages are handled by the coroutines.
6054 for (i = 0; i < 256; i++)
6055 ssh->packet_dispatch[i] = NULL;
6058 * These special message types we install handlers for.
6060 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
6061 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
6062 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
6065 static void ssh1_protocol(Ssh ssh, const void *vin, int inlen,
6066 struct Packet *pktin)
6068 const unsigned char *in = (const unsigned char *)vin;
6069 if (ssh->state == SSH_STATE_CLOSED)
6072 if (pktin && ssh->packet_dispatch[pktin->type]) {
6073 ssh->packet_dispatch[pktin->type](ssh, pktin);
6077 if (!ssh->protocol_initial_phase_done) {
6078 if (do_ssh1_login(ssh, in, inlen, pktin))
6079 ssh->protocol_initial_phase_done = TRUE;
6084 do_ssh1_connection(ssh, in, inlen, pktin);
6088 * Utility routines for decoding comma-separated strings in KEXINIT.
6090 static int first_in_commasep_string(char const *needle, char const *haystack,
6094 if (!needle || !haystack) /* protect against null pointers */
6096 needlen = strlen(needle);
6098 if (haylen >= needlen && /* haystack is long enough */
6099 !memcmp(needle, haystack, needlen) && /* initial match */
6100 (haylen == needlen || haystack[needlen] == ',')
6101 /* either , or EOS follows */
6107 static int in_commasep_string(char const *needle, char const *haystack,
6112 if (!needle || !haystack) /* protect against null pointers */
6115 * Is it at the start of the string?
6117 if (first_in_commasep_string(needle, haystack, haylen))
6120 * If not, search for the next comma and resume after that.
6121 * If no comma found, terminate.
6123 p = memchr(haystack, ',', haylen);
6125 /* + 1 to skip over comma */
6126 return in_commasep_string(needle, p + 1, haylen - (p + 1 - haystack));
6130 * Add a value to the comma-separated string at the end of the packet.
6132 static void ssh2_pkt_addstring_commasep(struct Packet *pkt, const char *data)
6134 if (pkt->length - pkt->savedpos > 0)
6135 ssh_pkt_addstring_str(pkt, ",");
6136 ssh_pkt_addstring_str(pkt, data);
6141 * SSH-2 key derivation (RFC 4253 section 7.2).
6143 static unsigned char *ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
6144 char chr, int keylen)
6146 const struct ssh_hash *h = ssh->kex->hash;
6154 /* Round up to the next multiple of hash length. */
6155 keylen_padded = ((keylen + h->hlen - 1) / h->hlen) * h->hlen;
6157 key = snewn(keylen_padded, unsigned char);
6159 /* First hlen bytes. */
6161 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6162 hash_mpint(h, s, K);
6163 h->bytes(s, H, h->hlen);
6164 h->bytes(s, &chr, 1);
6165 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
6168 /* Subsequent blocks of hlen bytes. */
6169 if (keylen_padded > h->hlen) {
6173 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6174 hash_mpint(h, s, K);
6175 h->bytes(s, H, h->hlen);
6177 for (offset = h->hlen; offset < keylen_padded; offset += h->hlen) {
6178 h->bytes(s, key + offset - h->hlen, h->hlen);
6180 h->final(s2, key + offset);
6186 /* Now clear any extra bytes of key material beyond the length
6187 * we're officially returning, because the caller won't know to
6189 if (keylen_padded > keylen)
6190 smemclr(key + keylen, keylen_padded - keylen);
6196 * Structure for constructing KEXINIT algorithm lists.
6198 #define MAXKEXLIST 16
6199 struct kexinit_algorithm {
6203 const struct ssh_kex *kex;
6206 const struct ssh_signkey *hostkey;
6208 const struct ssh2_cipher *cipher;
6212 const struct ssh_mac *mac;
6215 const struct ssh_compress *comp;
6220 * Find a slot in a KEXINIT algorithm list to use for a new algorithm.
6221 * If the algorithm is already in the list, return a pointer to its
6222 * entry, otherwise return an entry from the end of the list.
6223 * This assumes that every time a particular name is passed in, it
6224 * comes from the same string constant. If this isn't true, this
6225 * function may need to be rewritten to use strcmp() instead.
6227 static struct kexinit_algorithm *ssh2_kexinit_addalg(struct kexinit_algorithm
6228 *list, const char *name)
6232 for (i = 0; i < MAXKEXLIST; i++)
6233 if (list[i].name == NULL || list[i].name == name) {
6234 list[i].name = name;
6237 assert(!"No space in KEXINIT list");
6242 * Handle the SSH-2 transport layer.
6244 static void do_ssh2_transport(Ssh ssh, const void *vin, int inlen,
6245 struct Packet *pktin)
6247 const unsigned char *in = (const unsigned char *)vin;
6249 KEXLIST_KEX, KEXLIST_HOSTKEY, KEXLIST_CSCIPHER, KEXLIST_SCCIPHER,
6250 KEXLIST_CSMAC, KEXLIST_SCMAC, KEXLIST_CSCOMP, KEXLIST_SCCOMP,
6253 const char * kexlist_descr[NKEXLIST] = {
6254 "key exchange algorithm", "host key algorithm",
6255 "client-to-server cipher", "server-to-client cipher",
6256 "client-to-server MAC", "server-to-client MAC",
6257 "client-to-server compression method",
6258 "server-to-client compression method" };
6259 struct do_ssh2_transport_state {
6261 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
6262 Bignum p, g, e, f, K;
6265 int kex_init_value, kex_reply_value;
6266 const struct ssh_mac **maclist;
6268 const struct ssh2_cipher *cscipher_tobe;
6269 const struct ssh2_cipher *sccipher_tobe;
6270 const struct ssh_mac *csmac_tobe;
6271 const struct ssh_mac *scmac_tobe;
6272 int csmac_etm_tobe, scmac_etm_tobe;
6273 const struct ssh_compress *cscomp_tobe;
6274 const struct ssh_compress *sccomp_tobe;
6275 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
6276 int hostkeylen, siglen, rsakeylen;
6277 void *hkey; /* actual host key */
6278 void *rsakey; /* for RSA kex */
6279 void *eckey; /* for ECDH kex */
6280 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
6281 int n_preferred_kex;
6282 const struct ssh_kexes *preferred_kex[KEX_MAX];
6283 int n_preferred_ciphers;
6284 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
6285 const struct ssh_compress *preferred_comp;
6286 int userauth_succeeded; /* for delayed compression */
6287 int pending_compression;
6288 int got_session_id, activated_authconn;
6289 struct Packet *pktout;
6293 struct kexinit_algorithm kexlists[NKEXLIST][MAXKEXLIST];
6295 crState(do_ssh2_transport_state);
6297 assert(!ssh->bare_connection);
6301 s->cscipher_tobe = s->sccipher_tobe = NULL;
6302 s->csmac_tobe = s->scmac_tobe = NULL;
6303 s->cscomp_tobe = s->sccomp_tobe = NULL;
6305 s->got_session_id = s->activated_authconn = FALSE;
6306 s->userauth_succeeded = FALSE;
6307 s->pending_compression = FALSE;
6310 * Be prepared to work around the buggy MAC problem.
6312 if (ssh->remote_bugs & BUG_SSH2_HMAC)
6313 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
6315 s->maclist = macs, s->nmacs = lenof(macs);
6318 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
6321 struct kexinit_algorithm *alg;
6324 * Set up the preferred key exchange. (NULL => warn below here)
6326 s->n_preferred_kex = 0;
6327 for (i = 0; i < KEX_MAX; i++) {
6328 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
6330 s->preferred_kex[s->n_preferred_kex++] =
6331 &ssh_diffiehellman_gex;
6334 s->preferred_kex[s->n_preferred_kex++] =
6335 &ssh_diffiehellman_group14;
6338 s->preferred_kex[s->n_preferred_kex++] =
6339 &ssh_diffiehellman_group1;
6342 s->preferred_kex[s->n_preferred_kex++] =
6346 s->preferred_kex[s->n_preferred_kex++] =
6350 /* Flag for later. Don't bother if it's the last in
6352 if (i < KEX_MAX - 1) {
6353 s->preferred_kex[s->n_preferred_kex++] = NULL;
6360 * Set up the preferred ciphers. (NULL => warn below here)
6362 s->n_preferred_ciphers = 0;
6363 for (i = 0; i < CIPHER_MAX; i++) {
6364 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
6365 case CIPHER_BLOWFISH:
6366 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
6369 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
6370 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
6374 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
6377 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
6379 case CIPHER_ARCFOUR:
6380 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
6382 case CIPHER_CHACHA20:
6383 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_ccp;
6386 /* Flag for later. Don't bother if it's the last in
6388 if (i < CIPHER_MAX - 1) {
6389 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
6396 * Set up preferred compression.
6398 if (conf_get_int(ssh->conf, CONF_compression))
6399 s->preferred_comp = &ssh_zlib;
6401 s->preferred_comp = &ssh_comp_none;
6404 * Enable queueing of outgoing auth- or connection-layer
6405 * packets while we are in the middle of a key exchange.
6407 ssh->queueing = TRUE;
6410 * Flag that KEX is in progress.
6412 ssh->kex_in_progress = TRUE;
6414 for (i = 0; i < NKEXLIST; i++)
6415 for (j = 0; j < MAXKEXLIST; j++)
6416 s->kexlists[i][j].name = NULL;
6417 /* List key exchange algorithms. */
6419 for (i = 0; i < s->n_preferred_kex; i++) {
6420 const struct ssh_kexes *k = s->preferred_kex[i];
6421 if (!k) warn = TRUE;
6422 else for (j = 0; j < k->nkexes; j++) {
6423 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_KEX],
6425 alg->u.kex.kex = k->list[j];
6426 alg->u.kex.warn = warn;
6429 /* List server host key algorithms. */
6430 if (!s->got_session_id) {
6432 * In the first key exchange, we list all the algorithms
6433 * we're prepared to cope with, but prefer those algorithms
6434 * for which we have a host key for this host.
6436 for (i = 0; i < lenof(hostkey_algs); i++) {
6437 if (have_ssh_host_key(ssh->savedhost, ssh->savedport,
6438 hostkey_algs[i]->keytype)) {
6439 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY],
6440 hostkey_algs[i]->name);
6441 alg->u.hostkey = hostkey_algs[i];
6444 for (i = 0; i < lenof(hostkey_algs); i++) {
6445 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY],
6446 hostkey_algs[i]->name);
6447 alg->u.hostkey = hostkey_algs[i];
6451 * In subsequent key exchanges, we list only the kex
6452 * algorithm that was selected in the first key exchange,
6453 * so that we keep getting the same host key and hence
6454 * don't have to interrupt the user's session to ask for
6458 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY],
6459 ssh->hostkey->name);
6460 alg->u.hostkey = ssh->hostkey;
6462 /* List encryption algorithms (client->server then server->client). */
6463 for (k = KEXLIST_CSCIPHER; k <= KEXLIST_SCCIPHER; k++) {
6465 for (i = 0; i < s->n_preferred_ciphers; i++) {
6466 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6467 if (!c) warn = TRUE;
6468 else for (j = 0; j < c->nciphers; j++) {
6469 alg = ssh2_kexinit_addalg(s->kexlists[k],
6471 alg->u.cipher.cipher = c->list[j];
6472 alg->u.cipher.warn = warn;
6476 /* List MAC algorithms (client->server then server->client). */
6477 for (j = KEXLIST_CSMAC; j <= KEXLIST_SCMAC; j++) {
6478 for (i = 0; i < s->nmacs; i++) {
6479 alg = ssh2_kexinit_addalg(s->kexlists[j], s->maclist[i]->name);
6480 alg->u.mac.mac = s->maclist[i];
6481 alg->u.mac.etm = FALSE;
6483 for (i = 0; i < s->nmacs; i++)
6484 /* For each MAC, there may also be an ETM version,
6485 * which we list second. */
6486 if (s->maclist[i]->etm_name) {
6487 alg = ssh2_kexinit_addalg(s->kexlists[j],
6488 s->maclist[i]->etm_name);
6489 alg->u.mac.mac = s->maclist[i];
6490 alg->u.mac.etm = TRUE;
6493 /* List client->server compression algorithms,
6494 * then server->client compression algorithms. (We use the
6495 * same set twice.) */
6496 for (j = KEXLIST_CSCOMP; j <= KEXLIST_SCCOMP; j++) {
6497 assert(lenof(compressions) > 1);
6498 /* Prefer non-delayed versions */
6499 alg = ssh2_kexinit_addalg(s->kexlists[j], s->preferred_comp->name);
6500 alg->u.comp = s->preferred_comp;
6501 /* We don't even list delayed versions of algorithms until
6502 * they're allowed to be used, to avoid a race. See the end of
6504 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
6505 alg = ssh2_kexinit_addalg(s->kexlists[j],
6506 s->preferred_comp->delayed_name);
6507 alg->u.comp = s->preferred_comp;
6509 for (i = 0; i < lenof(compressions); i++) {
6510 const struct ssh_compress *c = compressions[i];
6511 alg = ssh2_kexinit_addalg(s->kexlists[j], c->name);
6513 if (s->userauth_succeeded && c->delayed_name) {
6514 alg = ssh2_kexinit_addalg(s->kexlists[j], c->delayed_name);
6520 * Construct and send our key exchange packet.
6522 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
6523 for (i = 0; i < 16; i++)
6524 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
6525 for (i = 0; i < NKEXLIST; i++) {
6526 ssh2_pkt_addstring_start(s->pktout);
6527 for (j = 0; j < MAXKEXLIST; j++) {
6528 if (s->kexlists[i][j].name == NULL) break;
6529 ssh2_pkt_addstring_commasep(s->pktout, s->kexlists[i][j].name);
6532 /* List client->server languages. Empty list. */
6533 ssh2_pkt_addstring_start(s->pktout);
6534 /* List server->client languages. Empty list. */
6535 ssh2_pkt_addstring_start(s->pktout);
6536 /* First KEX packet does _not_ follow, because we're not that brave. */
6537 ssh2_pkt_addbool(s->pktout, FALSE);
6539 ssh2_pkt_adduint32(s->pktout, 0);
6542 s->our_kexinitlen = s->pktout->length - 5;
6543 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
6544 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
6546 ssh2_pkt_send_noqueue(ssh, s->pktout);
6549 crWaitUntilV(pktin);
6552 * Now examine the other side's KEXINIT to see what we're up
6559 if (pktin->type != SSH2_MSG_KEXINIT) {
6560 bombout(("expected key exchange packet from server"));
6564 ssh->hostkey = NULL;
6565 s->cscipher_tobe = NULL;
6566 s->sccipher_tobe = NULL;
6567 s->csmac_tobe = NULL;
6568 s->scmac_tobe = NULL;
6569 s->cscomp_tobe = NULL;
6570 s->sccomp_tobe = NULL;
6571 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
6573 pktin->savedpos += 16; /* skip garbage cookie */
6576 for (i = 0; i < NKEXLIST; i++) {
6577 ssh_pkt_getstring(pktin, &str, &len);
6579 bombout(("KEXINIT packet was incomplete"));
6583 /* If we've already selected a cipher which requires a
6584 * particular MAC, then just select that, and don't even
6585 * bother looking through the server's KEXINIT string for
6587 if (i == KEXLIST_CSMAC && s->cscipher_tobe &&
6588 s->cscipher_tobe->required_mac) {
6589 s->csmac_tobe = s->cscipher_tobe->required_mac;
6590 s->csmac_etm_tobe = !!(s->csmac_tobe->etm_name);
6593 if (i == KEXLIST_SCMAC && s->sccipher_tobe &&
6594 s->sccipher_tobe->required_mac) {
6595 s->scmac_tobe = s->sccipher_tobe->required_mac;
6596 s->scmac_etm_tobe = !!(s->scmac_tobe->etm_name);
6600 for (j = 0; j < MAXKEXLIST; j++) {
6601 struct kexinit_algorithm *alg = &s->kexlists[i][j];
6602 if (alg->name == NULL) break;
6603 if (in_commasep_string(alg->name, str, len)) {
6604 /* We've found a matching algorithm. */
6605 if (i == KEXLIST_KEX || i == KEXLIST_HOSTKEY) {
6606 /* Check if we might need to ignore first kex pkt */
6608 !first_in_commasep_string(alg->name, str, len))
6611 if (i == KEXLIST_KEX) {
6612 ssh->kex = alg->u.kex.kex;
6613 s->warn_kex = alg->u.kex.warn;
6614 } else if (i == KEXLIST_HOSTKEY) {
6615 ssh->hostkey = alg->u.hostkey;
6616 } else if (i == KEXLIST_CSCIPHER) {
6617 s->cscipher_tobe = alg->u.cipher.cipher;
6618 s->warn_cscipher = alg->u.cipher.warn;
6619 } else if (i == KEXLIST_SCCIPHER) {
6620 s->sccipher_tobe = alg->u.cipher.cipher;
6621 s->warn_sccipher = alg->u.cipher.warn;
6622 } else if (i == KEXLIST_CSMAC) {
6623 s->csmac_tobe = alg->u.mac.mac;
6624 s->csmac_etm_tobe = alg->u.mac.etm;
6625 } else if (i == KEXLIST_SCMAC) {
6626 s->scmac_tobe = alg->u.mac.mac;
6627 s->scmac_etm_tobe = alg->u.mac.etm;
6628 } else if (i == KEXLIST_CSCOMP) {
6629 s->cscomp_tobe = alg->u.comp;
6630 } else if (i == KEXLIST_SCCOMP) {
6631 s->sccomp_tobe = alg->u.comp;
6635 if ((i == KEXLIST_CSCOMP || i == KEXLIST_SCCOMP) &&
6636 in_commasep_string(alg->u.comp->delayed_name, str, len))
6637 s->pending_compression = TRUE; /* try this later */
6639 bombout(("Couldn't agree a %s ((available: %.*s)",
6640 kexlist_descr[i], len, str));
6645 if (s->pending_compression) {
6646 logevent("Server supports delayed compression; "
6647 "will try this later");
6649 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
6650 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
6651 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
6653 ssh->exhash = ssh->kex->hash->init();
6654 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
6655 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
6656 hash_string(ssh->kex->hash, ssh->exhash,
6657 s->our_kexinit, s->our_kexinitlen);
6658 sfree(s->our_kexinit);
6659 /* Include the type byte in the hash of server's KEXINIT */
6660 hash_string(ssh->kex->hash, ssh->exhash,
6661 pktin->body - 1, pktin->length + 1);
6664 ssh_set_frozen(ssh, 1);
6665 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
6667 ssh_dialog_callback, ssh);
6668 if (s->dlgret < 0) {
6672 bombout(("Unexpected data from server while"
6673 " waiting for user response"));
6676 } while (pktin || inlen > 0);
6677 s->dlgret = ssh->user_response;
6679 ssh_set_frozen(ssh, 0);
6680 if (s->dlgret == 0) {
6681 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
6687 if (s->warn_cscipher) {
6688 ssh_set_frozen(ssh, 1);
6689 s->dlgret = askalg(ssh->frontend,
6690 "client-to-server cipher",
6691 s->cscipher_tobe->name,
6692 ssh_dialog_callback, ssh);
6693 if (s->dlgret < 0) {
6697 bombout(("Unexpected data from server while"
6698 " waiting for user response"));
6701 } while (pktin || inlen > 0);
6702 s->dlgret = ssh->user_response;
6704 ssh_set_frozen(ssh, 0);
6705 if (s->dlgret == 0) {
6706 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6712 if (s->warn_sccipher) {
6713 ssh_set_frozen(ssh, 1);
6714 s->dlgret = askalg(ssh->frontend,
6715 "server-to-client cipher",
6716 s->sccipher_tobe->name,
6717 ssh_dialog_callback, ssh);
6718 if (s->dlgret < 0) {
6722 bombout(("Unexpected data from server while"
6723 " waiting for user response"));
6726 } while (pktin || inlen > 0);
6727 s->dlgret = ssh->user_response;
6729 ssh_set_frozen(ssh, 0);
6730 if (s->dlgret == 0) {
6731 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6737 if (s->ignorepkt) /* first_kex_packet_follows */
6738 crWaitUntilV(pktin); /* Ignore packet */
6741 if (ssh->kex->main_type == KEXTYPE_DH) {
6743 * Work out the number of bits of key we will need from the
6744 * key exchange. We start with the maximum key length of
6750 csbits = s->cscipher_tobe->real_keybits;
6751 scbits = s->sccipher_tobe->real_keybits;
6752 s->nbits = (csbits > scbits ? csbits : scbits);
6754 /* The keys only have hlen-bit entropy, since they're based on
6755 * a hash. So cap the key size at hlen bits. */
6756 if (s->nbits > ssh->kex->hash->hlen * 8)
6757 s->nbits = ssh->kex->hash->hlen * 8;
6760 * If we're doing Diffie-Hellman group exchange, start by
6761 * requesting a group.
6763 if (dh_is_gex(ssh->kex)) {
6764 logevent("Doing Diffie-Hellman group exchange");
6765 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
6767 * Work out how big a DH group we will need to allow that
6770 s->pbits = 512 << ((s->nbits - 1) / 64);
6771 if (s->pbits < DH_MIN_SIZE)
6772 s->pbits = DH_MIN_SIZE;
6773 if (s->pbits > DH_MAX_SIZE)
6774 s->pbits = DH_MAX_SIZE;
6775 if ((ssh->remote_bugs & BUG_SSH2_OLDGEX)) {
6776 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST_OLD);
6777 ssh2_pkt_adduint32(s->pktout, s->pbits);
6779 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6780 ssh2_pkt_adduint32(s->pktout, DH_MIN_SIZE);
6781 ssh2_pkt_adduint32(s->pktout, s->pbits);
6782 ssh2_pkt_adduint32(s->pktout, DH_MAX_SIZE);
6784 ssh2_pkt_send_noqueue(ssh, s->pktout);
6786 crWaitUntilV(pktin);
6787 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6788 bombout(("expected key exchange group packet from server"));
6791 s->p = ssh2_pkt_getmp(pktin);
6792 s->g = ssh2_pkt_getmp(pktin);
6793 if (!s->p || !s->g) {
6794 bombout(("unable to read mp-ints from incoming group packet"));
6797 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6798 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6799 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6801 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
6802 ssh->kex_ctx = dh_setup_group(ssh->kex);
6803 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6804 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6805 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6806 ssh->kex->groupname);
6809 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6810 ssh->kex->hash->text_name);
6812 * Now generate and send e for Diffie-Hellman.
6814 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6815 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6816 s->pktout = ssh2_pkt_init(s->kex_init_value);
6817 ssh2_pkt_addmp(s->pktout, s->e);
6818 ssh2_pkt_send_noqueue(ssh, s->pktout);
6820 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
6821 crWaitUntilV(pktin);
6822 if (pktin->type != s->kex_reply_value) {
6823 bombout(("expected key exchange reply packet from server"));
6826 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
6827 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6828 if (!s->hostkeydata) {
6829 bombout(("unable to parse key exchange reply packet"));
6832 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
6833 s->hostkeydata, s->hostkeylen);
6834 s->f = ssh2_pkt_getmp(pktin);
6836 bombout(("unable to parse key exchange reply packet"));
6839 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6841 bombout(("unable to parse key exchange reply packet"));
6846 const char *err = dh_validate_f(ssh->kex_ctx, s->f);
6848 bombout(("key exchange reply failed validation: %s", err));
6852 s->K = dh_find_K(ssh->kex_ctx, s->f);
6854 /* We assume everything from now on will be quick, and it might
6855 * involve user interaction. */
6856 set_busy_status(ssh->frontend, BUSY_NOT);
6858 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6859 if (dh_is_gex(ssh->kex)) {
6860 if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX))
6861 hash_uint32(ssh->kex->hash, ssh->exhash, DH_MIN_SIZE);
6862 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
6863 if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX))
6864 hash_uint32(ssh->kex->hash, ssh->exhash, DH_MAX_SIZE);
6865 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
6866 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
6868 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
6869 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
6871 dh_cleanup(ssh->kex_ctx);
6873 if (dh_is_gex(ssh->kex)) {
6877 } else if (ssh->kex->main_type == KEXTYPE_ECDH) {
6879 logeventf(ssh, "Doing ECDH key exchange with curve %s and hash %s",
6880 ssh_ecdhkex_curve_textname(ssh->kex),
6881 ssh->kex->hash->text_name);
6882 ssh->pkt_kctx = SSH2_PKTCTX_ECDHKEX;
6884 s->eckey = ssh_ecdhkex_newkey(ssh->kex);
6886 bombout(("Unable to generate key for ECDH"));
6892 int publicPointLength;
6893 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
6895 ssh_ecdhkex_freekey(s->eckey);
6896 bombout(("Unable to encode public key for ECDH"));
6899 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_ECDH_INIT);
6900 ssh2_pkt_addstring_start(s->pktout);
6901 ssh2_pkt_addstring_data(s->pktout, publicPoint, publicPointLength);
6905 ssh2_pkt_send_noqueue(ssh, s->pktout);
6907 crWaitUntilV(pktin);
6908 if (pktin->type != SSH2_MSG_KEX_ECDH_REPLY) {
6909 ssh_ecdhkex_freekey(s->eckey);
6910 bombout(("expected ECDH reply packet from server"));
6914 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6915 if (!s->hostkeydata) {
6916 bombout(("unable to parse ECDH reply packet"));
6919 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6920 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
6921 s->hostkeydata, s->hostkeylen);
6925 int publicPointLength;
6926 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
6928 ssh_ecdhkex_freekey(s->eckey);
6929 bombout(("Unable to encode public key for ECDH hash"));
6932 hash_string(ssh->kex->hash, ssh->exhash,
6933 publicPoint, publicPointLength);
6940 ssh_pkt_getstring(pktin, &keydata, &keylen);
6942 bombout(("unable to parse ECDH reply packet"));
6945 hash_string(ssh->kex->hash, ssh->exhash, keydata, keylen);
6946 s->K = ssh_ecdhkex_getkey(s->eckey, keydata, keylen);
6948 ssh_ecdhkex_freekey(s->eckey);
6949 bombout(("point received in ECDH was not valid"));
6954 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6956 bombout(("unable to parse key exchange reply packet"));
6960 ssh_ecdhkex_freekey(s->eckey);
6962 logeventf(ssh, "Doing RSA key exchange with hash %s",
6963 ssh->kex->hash->text_name);
6964 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
6966 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6969 crWaitUntilV(pktin);
6970 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
6971 bombout(("expected RSA public key packet from server"));
6975 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6976 if (!s->hostkeydata) {
6977 bombout(("unable to parse RSA public key packet"));
6980 hash_string(ssh->kex->hash, ssh->exhash,
6981 s->hostkeydata, s->hostkeylen);
6982 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
6983 s->hostkeydata, s->hostkeylen);
6987 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
6989 bombout(("unable to parse RSA public key packet"));
6992 s->rsakeydata = snewn(s->rsakeylen, char);
6993 memcpy(s->rsakeydata, keydata, s->rsakeylen);
6996 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
6998 sfree(s->rsakeydata);
6999 bombout(("unable to parse RSA public key from server"));
7003 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
7006 * Next, set up a shared secret K, of precisely KLEN -
7007 * 2*HLEN - 49 bits, where KLEN is the bit length of the
7008 * RSA key modulus and HLEN is the bit length of the hash
7012 int klen = ssh_rsakex_klen(s->rsakey);
7013 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
7015 unsigned char *kstr1, *kstr2, *outstr;
7016 int kstr1len, kstr2len, outstrlen;
7018 s->K = bn_power_2(nbits - 1);
7020 for (i = 0; i < nbits; i++) {
7022 byte = random_byte();
7024 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
7028 * Encode this as an mpint.
7030 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
7031 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
7032 PUT_32BIT(kstr2, kstr1len);
7033 memcpy(kstr2 + 4, kstr1, kstr1len);
7036 * Encrypt it with the given RSA key.
7038 outstrlen = (klen + 7) / 8;
7039 outstr = snewn(outstrlen, unsigned char);
7040 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
7041 outstr, outstrlen, s->rsakey);
7044 * And send it off in a return packet.
7046 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
7047 ssh2_pkt_addstring_start(s->pktout);
7048 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
7049 ssh2_pkt_send_noqueue(ssh, s->pktout);
7051 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
7058 ssh_rsakex_freekey(s->rsakey);
7060 crWaitUntilV(pktin);
7061 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
7062 sfree(s->rsakeydata);
7063 bombout(("expected signature packet from server"));
7067 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
7069 bombout(("unable to parse signature packet"));
7073 sfree(s->rsakeydata);
7076 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
7077 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
7078 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
7080 ssh->kex_ctx = NULL;
7083 debug(("Exchange hash is:\n"));
7084 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
7088 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
7089 (char *)s->exchange_hash,
7090 ssh->kex->hash->hlen)) {
7091 bombout(("Server's host key did not match the signature supplied"));
7095 s->keystr = ssh->hostkey->fmtkey(s->hkey);
7096 if (!s->got_session_id) {
7098 * Authenticate remote host: verify host key. (We've already
7099 * checked the signature of the exchange hash.)
7101 s->fingerprint = ssh2_fingerprint(ssh->hostkey, s->hkey);
7102 logevent("Host key fingerprint is:");
7103 logevent(s->fingerprint);
7104 /* First check against manually configured host keys. */
7105 s->dlgret = verify_ssh_manual_host_key(ssh, s->fingerprint,
7106 ssh->hostkey, s->hkey);
7107 if (s->dlgret == 0) { /* did not match */
7108 bombout(("Host key did not appear in manually configured list"));
7110 } else if (s->dlgret < 0) { /* none configured; use standard handling */
7111 ssh_set_frozen(ssh, 1);
7112 s->dlgret = verify_ssh_host_key(ssh->frontend,
7113 ssh->savedhost, ssh->savedport,
7114 ssh->hostkey->keytype, s->keystr,
7116 ssh_dialog_callback, ssh);
7117 if (s->dlgret < 0) {
7121 bombout(("Unexpected data from server while waiting"
7122 " for user host key response"));
7125 } while (pktin || inlen > 0);
7126 s->dlgret = ssh->user_response;
7128 ssh_set_frozen(ssh, 0);
7129 if (s->dlgret == 0) {
7130 ssh_disconnect(ssh, "Aborted at host key verification", NULL,
7135 sfree(s->fingerprint);
7137 * Save this host key, to check against the one presented in
7138 * subsequent rekeys.
7140 ssh->hostkey_str = s->keystr;
7143 * In a rekey, we never present an interactive host key
7144 * verification request to the user. Instead, we simply
7145 * enforce that the key we're seeing this time is identical to
7146 * the one we saw before.
7148 if (strcmp(ssh->hostkey_str, s->keystr)) {
7149 bombout(("Host key was different in repeat key exchange"));
7154 ssh->hostkey->freekey(s->hkey);
7157 * The exchange hash from the very first key exchange is also
7158 * the session id, used in session key construction and
7161 if (!s->got_session_id) {
7162 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
7163 memcpy(ssh->v2_session_id, s->exchange_hash,
7164 sizeof(s->exchange_hash));
7165 ssh->v2_session_id_len = ssh->kex->hash->hlen;
7166 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
7167 s->got_session_id = TRUE;
7171 * Send SSH2_MSG_NEWKEYS.
7173 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
7174 ssh2_pkt_send_noqueue(ssh, s->pktout);
7175 ssh->outgoing_data_size = 0; /* start counting from here */
7178 * We've sent client NEWKEYS, so create and initialise
7179 * client-to-server session keys.
7181 if (ssh->cs_cipher_ctx)
7182 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7183 ssh->cscipher = s->cscipher_tobe;
7184 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
7186 if (ssh->cs_mac_ctx)
7187 ssh->csmac->free_context(ssh->cs_mac_ctx);
7188 ssh->csmac = s->csmac_tobe;
7189 ssh->csmac_etm = s->csmac_etm_tobe;
7190 ssh->cs_mac_ctx = ssh->csmac->make_context(ssh->cs_cipher_ctx);
7192 if (ssh->cs_comp_ctx)
7193 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7194 ssh->cscomp = s->cscomp_tobe;
7195 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
7198 * Set IVs on client-to-server keys. Here we use the exchange
7199 * hash from the _first_ key exchange.
7204 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'C',
7205 ssh->cscipher->padded_keybytes);
7206 ssh->cscipher->setkey(ssh->cs_cipher_ctx, key);
7207 smemclr(key, ssh->cscipher->padded_keybytes);
7210 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'A',
7211 ssh->cscipher->blksize);
7212 ssh->cscipher->setiv(ssh->cs_cipher_ctx, key);
7213 smemclr(key, ssh->cscipher->blksize);
7216 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'E',
7217 ssh->csmac->keylen);
7218 ssh->csmac->setkey(ssh->cs_mac_ctx, key);
7219 smemclr(key, ssh->csmac->keylen);
7223 logeventf(ssh, "Initialised %.200s client->server encryption",
7224 ssh->cscipher->text_name);
7225 logeventf(ssh, "Initialised %.200s client->server MAC algorithm%s%s",
7226 ssh->csmac->text_name,
7227 ssh->csmac_etm ? " (in ETM mode)" : "",
7228 ssh->cscipher->required_mac ? " (required by cipher)" : "");
7229 if (ssh->cscomp->text_name)
7230 logeventf(ssh, "Initialised %s compression",
7231 ssh->cscomp->text_name);
7234 * Now our end of the key exchange is complete, we can send all
7235 * our queued higher-layer packets.
7237 ssh->queueing = FALSE;
7238 ssh2_pkt_queuesend(ssh);
7241 * Expect SSH2_MSG_NEWKEYS from server.
7243 crWaitUntilV(pktin);
7244 if (pktin->type != SSH2_MSG_NEWKEYS) {
7245 bombout(("expected new-keys packet from server"));
7248 ssh->incoming_data_size = 0; /* start counting from here */
7251 * We've seen server NEWKEYS, so create and initialise
7252 * server-to-client session keys.
7254 if (ssh->sc_cipher_ctx)
7255 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7256 ssh->sccipher = s->sccipher_tobe;
7257 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
7259 if (ssh->sc_mac_ctx)
7260 ssh->scmac->free_context(ssh->sc_mac_ctx);
7261 ssh->scmac = s->scmac_tobe;
7262 ssh->scmac_etm = s->scmac_etm_tobe;
7263 ssh->sc_mac_ctx = ssh->scmac->make_context(ssh->sc_cipher_ctx);
7265 if (ssh->sc_comp_ctx)
7266 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7267 ssh->sccomp = s->sccomp_tobe;
7268 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
7271 * Set IVs on server-to-client keys. Here we use the exchange
7272 * hash from the _first_ key exchange.
7277 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'D',
7278 ssh->sccipher->padded_keybytes);
7279 ssh->sccipher->setkey(ssh->sc_cipher_ctx, key);
7280 smemclr(key, ssh->sccipher->padded_keybytes);
7283 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'B',
7284 ssh->sccipher->blksize);
7285 ssh->sccipher->setiv(ssh->sc_cipher_ctx, key);
7286 smemclr(key, ssh->sccipher->blksize);
7289 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'F',
7290 ssh->scmac->keylen);
7291 ssh->scmac->setkey(ssh->sc_mac_ctx, key);
7292 smemclr(key, ssh->scmac->keylen);
7295 logeventf(ssh, "Initialised %.200s server->client encryption",
7296 ssh->sccipher->text_name);
7297 logeventf(ssh, "Initialised %.200s server->client MAC algorithm%s%s",
7298 ssh->scmac->text_name,
7299 ssh->scmac_etm ? " (in ETM mode)" : "",
7300 ssh->sccipher->required_mac ? " (required by cipher)" : "");
7301 if (ssh->sccomp->text_name)
7302 logeventf(ssh, "Initialised %s decompression",
7303 ssh->sccomp->text_name);
7306 * Free shared secret.
7311 * Key exchange is over. Loop straight back round if we have a
7312 * deferred rekey reason.
7314 if (ssh->deferred_rekey_reason) {
7315 logevent(ssh->deferred_rekey_reason);
7317 ssh->deferred_rekey_reason = NULL;
7318 goto begin_key_exchange;
7322 * Otherwise, schedule a timer for our next rekey.
7324 ssh->kex_in_progress = FALSE;
7325 ssh->last_rekey = GETTICKCOUNT();
7326 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
7327 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7331 * Now we're encrypting. Begin returning 1 to the protocol main
7332 * function so that other things can run on top of the
7333 * transport. If we ever see a KEXINIT, we must go back to the
7336 * We _also_ go back to the start if we see pktin==NULL and
7337 * inlen negative, because this is a special signal meaning
7338 * `initiate client-driven rekey', and `in' contains a message
7339 * giving the reason for the rekey.
7341 * inlen==-1 means always initiate a rekey;
7342 * inlen==-2 means that userauth has completed successfully and
7343 * we should consider rekeying (for delayed compression).
7345 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
7346 (!pktin && inlen < 0))) {
7348 if (!ssh->protocol_initial_phase_done) {
7349 ssh->protocol_initial_phase_done = TRUE;
7351 * Allow authconn to initialise itself.
7353 do_ssh2_authconn(ssh, NULL, 0, NULL);
7358 logevent("Server initiated key re-exchange");
7362 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
7363 * delayed compression, if it's available.
7365 * draft-miller-secsh-compression-delayed-00 says that you
7366 * negotiate delayed compression in the first key exchange, and
7367 * both sides start compressing when the server has sent
7368 * USERAUTH_SUCCESS. This has a race condition -- the server
7369 * can't know when the client has seen it, and thus which incoming
7370 * packets it should treat as compressed.
7372 * Instead, we do the initial key exchange without offering the
7373 * delayed methods, but note if the server offers them; when we
7374 * get here, if a delayed method was available that was higher
7375 * on our list than what we got, we initiate a rekey in which we
7376 * _do_ list the delayed methods (and hopefully get it as a
7377 * result). Subsequent rekeys will do the same.
7379 assert(!s->userauth_succeeded); /* should only happen once */
7380 s->userauth_succeeded = TRUE;
7381 if (!s->pending_compression)
7382 /* Can't see any point rekeying. */
7383 goto wait_for_rekey; /* this is utterly horrid */
7384 /* else fall through to rekey... */
7385 s->pending_compression = FALSE;
7388 * Now we've decided to rekey.
7390 * Special case: if the server bug is set that doesn't
7391 * allow rekeying, we give a different log message and
7392 * continue waiting. (If such a server _initiates_ a rekey,
7393 * we process it anyway!)
7395 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
7396 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
7398 /* Reset the counters, so that at least this message doesn't
7399 * hit the event log _too_ often. */
7400 ssh->outgoing_data_size = 0;
7401 ssh->incoming_data_size = 0;
7402 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
7404 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7407 goto wait_for_rekey; /* this is still utterly horrid */
7409 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
7412 goto begin_key_exchange;
7418 * Add data to an SSH-2 channel output buffer.
7420 static void ssh2_add_channel_data(struct ssh_channel *c, const char *buf,
7423 bufchain_add(&c->v.v2.outbuffer, buf, len);
7427 * Attempt to send data on an SSH-2 channel.
7429 static int ssh2_try_send(struct ssh_channel *c)
7432 struct Packet *pktout;
7435 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
7438 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
7439 if ((unsigned)len > c->v.v2.remwindow)
7440 len = c->v.v2.remwindow;
7441 if ((unsigned)len > c->v.v2.remmaxpkt)
7442 len = c->v.v2.remmaxpkt;
7443 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
7444 ssh2_pkt_adduint32(pktout, c->remoteid);
7445 ssh2_pkt_addstring_start(pktout);
7446 ssh2_pkt_addstring_data(pktout, data, len);
7447 ssh2_pkt_send(ssh, pktout);
7448 bufchain_consume(&c->v.v2.outbuffer, len);
7449 c->v.v2.remwindow -= len;
7453 * After having sent as much data as we can, return the amount
7456 ret = bufchain_size(&c->v.v2.outbuffer);
7459 * And if there's no data pending but we need to send an EOF, send
7462 if (!ret && c->pending_eof)
7463 ssh_channel_try_eof(c);
7468 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
7471 if (c->closes & CLOSES_SENT_EOF)
7472 return; /* don't send on channels we've EOFed */
7473 bufsize = ssh2_try_send(c);
7476 case CHAN_MAINSESSION:
7477 /* stdin need not receive an unthrottle
7478 * notification since it will be polled */
7481 x11_unthrottle(c->u.x11.xconn);
7484 /* agent sockets are request/response and need no
7485 * buffer management */
7488 pfd_unthrottle(c->u.pfd.pf);
7494 static int ssh_is_simple(Ssh ssh)
7497 * We use the 'simple' variant of the SSH protocol if we're asked
7498 * to, except not if we're also doing connection-sharing (either
7499 * tunnelling our packets over an upstream or expecting to be
7500 * tunnelled over ourselves), since then the assumption that we
7501 * have only one channel to worry about is not true after all.
7503 return (conf_get_int(ssh->conf, CONF_ssh_simple) &&
7504 !ssh->bare_connection && !ssh->connshare);
7508 * Set up most of a new ssh_channel for SSH-2.
7510 static void ssh2_channel_init(struct ssh_channel *c)
7513 c->localid = alloc_channel_id(ssh);
7515 c->pending_eof = FALSE;
7516 c->throttling_conn = FALSE;
7517 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
7518 ssh_is_simple(ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
7519 c->v.v2.chanreq_head = NULL;
7520 c->v.v2.throttle_state = UNTHROTTLED;
7521 bufchain_init(&c->v.v2.outbuffer);
7525 * Construct the common parts of a CHANNEL_OPEN.
7527 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c,
7530 struct Packet *pktout;
7532 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7533 ssh2_pkt_addstring(pktout, type);
7534 ssh2_pkt_adduint32(pktout, c->localid);
7535 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7536 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7541 * CHANNEL_FAILURE doesn't come with any indication of what message
7542 * caused it, so we have to keep track of the outstanding
7543 * CHANNEL_REQUESTs ourselves.
7545 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
7546 cchandler_fn_t handler, void *ctx)
7548 struct outstanding_channel_request *ocr =
7549 snew(struct outstanding_channel_request);
7551 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7552 ocr->handler = handler;
7555 if (!c->v.v2.chanreq_head)
7556 c->v.v2.chanreq_head = ocr;
7558 c->v.v2.chanreq_tail->next = ocr;
7559 c->v.v2.chanreq_tail = ocr;
7563 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
7564 * NULL then a reply will be requested and the handler will be called
7565 * when it arrives. The returned packet is ready to have any
7566 * request-specific data added and be sent. Note that if a handler is
7567 * provided, it's essential that the request actually be sent.
7569 * The handler will usually be passed the response packet in pktin. If
7570 * pktin is NULL, this means that no reply will ever be forthcoming
7571 * (e.g. because the entire connection is being destroyed, or because
7572 * the server initiated channel closure before we saw the response)
7573 * and the handler should free any storage it's holding.
7575 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c,
7577 cchandler_fn_t handler, void *ctx)
7579 struct Packet *pktout;
7581 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7582 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7583 ssh2_pkt_adduint32(pktout, c->remoteid);
7584 ssh2_pkt_addstring(pktout, type);
7585 ssh2_pkt_addbool(pktout, handler != NULL);
7586 if (handler != NULL)
7587 ssh2_queue_chanreq_handler(c, handler, ctx);
7592 * Potentially enlarge the window on an SSH-2 channel.
7594 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
7596 static void ssh2_set_window(struct ssh_channel *c, int newwin)
7601 * Never send WINDOW_ADJUST for a channel that the remote side has
7602 * already sent EOF on; there's no point, since it won't be
7603 * sending any more data anyway. Ditto if _we've_ already sent
7606 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
7610 * Also, never widen the window for an X11 channel when we're
7611 * still waiting to see its initial auth and may yet hand it off
7614 if (c->type == CHAN_X11 && c->u.x11.initial)
7618 * If the remote end has a habit of ignoring maxpkt, limit the
7619 * window so that it has no choice (assuming it doesn't ignore the
7622 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
7623 newwin = OUR_V2_MAXPKT;
7626 * Only send a WINDOW_ADJUST if there's significantly more window
7627 * available than the other end thinks there is. This saves us
7628 * sending a WINDOW_ADJUST for every character in a shell session.
7630 * "Significant" is arbitrarily defined as half the window size.
7632 if (newwin / 2 >= c->v.v2.locwindow) {
7633 struct Packet *pktout;
7637 * In order to keep track of how much window the client
7638 * actually has available, we'd like it to acknowledge each
7639 * WINDOW_ADJUST. We can't do that directly, so we accompany
7640 * it with a CHANNEL_REQUEST that has to be acknowledged.
7642 * This is only necessary if we're opening the window wide.
7643 * If we're not, then throughput is being constrained by
7644 * something other than the maximum window size anyway.
7646 if (newwin == c->v.v2.locmaxwin &&
7647 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
7648 up = snew(unsigned);
7649 *up = newwin - c->v.v2.locwindow;
7650 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
7651 ssh2_handle_winadj_response, up);
7652 ssh2_pkt_send(ssh, pktout);
7654 if (c->v.v2.throttle_state != UNTHROTTLED)
7655 c->v.v2.throttle_state = UNTHROTTLING;
7657 /* Pretend the WINDOW_ADJUST was acked immediately. */
7658 c->v.v2.remlocwin = newwin;
7659 c->v.v2.throttle_state = THROTTLED;
7661 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7662 ssh2_pkt_adduint32(pktout, c->remoteid);
7663 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
7664 ssh2_pkt_send(ssh, pktout);
7665 c->v.v2.locwindow = newwin;
7670 * Find the channel associated with a message. If there's no channel,
7671 * or it's not properly open, make a noise about it and return NULL.
7673 static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
7675 unsigned localid = ssh_pkt_getuint32(pktin);
7676 struct ssh_channel *c;
7678 c = find234(ssh->channels, &localid, ssh_channelfind);
7680 (c->type != CHAN_SHARING && c->halfopen &&
7681 pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
7682 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
7683 char *buf = dupprintf("Received %s for %s channel %u",
7684 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
7686 c ? "half-open" : "nonexistent", localid);
7687 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
7694 static void ssh2_handle_winadj_response(struct ssh_channel *c,
7695 struct Packet *pktin, void *ctx)
7697 unsigned *sizep = ctx;
7700 * Winadj responses should always be failures. However, at least
7701 * one server ("boks_sshd") is known to return SUCCESS for channel
7702 * requests it's never heard of, such as "winadj@putty". Raised
7703 * with foxt.com as bug 090916-090424, but for the sake of a quiet
7704 * life, we don't worry about what kind of response we got.
7707 c->v.v2.remlocwin += *sizep;
7710 * winadj messages are only sent when the window is fully open, so
7711 * if we get an ack of one, we know any pending unthrottle is
7714 if (c->v.v2.throttle_state == UNTHROTTLING)
7715 c->v.v2.throttle_state = UNTHROTTLED;
7718 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
7720 struct ssh_channel *c = ssh2_channel_msg(ssh, pktin);
7721 struct outstanding_channel_request *ocr;
7724 if (c->type == CHAN_SHARING) {
7725 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7726 pktin->body, pktin->length);
7729 ocr = c->v.v2.chanreq_head;
7731 ssh2_msg_unexpected(ssh, pktin);
7734 ocr->handler(c, pktin, ocr->ctx);
7735 c->v.v2.chanreq_head = ocr->next;
7738 * We may now initiate channel-closing procedures, if that
7739 * CHANNEL_REQUEST was the last thing outstanding before we send
7742 ssh2_channel_check_close(c);
7745 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
7747 struct ssh_channel *c;
7748 c = ssh2_channel_msg(ssh, pktin);
7751 if (c->type == CHAN_SHARING) {
7752 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7753 pktin->body, pktin->length);
7756 if (!(c->closes & CLOSES_SENT_EOF)) {
7757 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
7758 ssh2_try_send_and_unthrottle(ssh, c);
7762 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
7766 struct ssh_channel *c;
7767 c = ssh2_channel_msg(ssh, pktin);
7770 if (c->type == CHAN_SHARING) {
7771 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7772 pktin->body, pktin->length);
7775 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
7776 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
7777 return; /* extended but not stderr */
7778 ssh_pkt_getstring(pktin, &data, &length);
7781 c->v.v2.locwindow -= length;
7782 c->v.v2.remlocwin -= length;
7784 case CHAN_MAINSESSION:
7786 from_backend(ssh->frontend, pktin->type ==
7787 SSH2_MSG_CHANNEL_EXTENDED_DATA,
7791 bufsize = x11_send(c->u.x11.xconn, data, length);
7794 bufsize = pfd_send(c->u.pfd.pf, data, length);
7797 while (length > 0) {
7798 if (c->u.a.lensofar < 4) {
7799 unsigned int l = min(4 - c->u.a.lensofar,
7801 memcpy(c->u.a.msglen + c->u.a.lensofar,
7805 c->u.a.lensofar += l;
7807 if (c->u.a.lensofar == 4) {
7809 4 + GET_32BIT(c->u.a.msglen);
7810 c->u.a.message = snewn(c->u.a.totallen,
7812 memcpy(c->u.a.message, c->u.a.msglen, 4);
7814 if (c->u.a.lensofar >= 4 && length > 0) {
7816 min(c->u.a.totallen - c->u.a.lensofar,
7818 memcpy(c->u.a.message + c->u.a.lensofar,
7822 c->u.a.lensofar += l;
7824 if (c->u.a.lensofar == c->u.a.totallen) {
7827 c->u.a.outstanding_requests++;
7828 if (agent_query(c->u.a.message,
7831 ssh_agentf_callback, c))
7832 ssh_agentf_callback(c, reply, replylen);
7833 sfree(c->u.a.message);
7834 c->u.a.message = NULL;
7835 c->u.a.lensofar = 0;
7842 * If it looks like the remote end hit the end of its window,
7843 * and we didn't want it to do that, think about using a
7846 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
7847 c->v.v2.locmaxwin < 0x40000000)
7848 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
7850 * If we are not buffering too much data,
7851 * enlarge the window again at the remote side.
7852 * If we are buffering too much, we may still
7853 * need to adjust the window if the server's
7856 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
7857 c->v.v2.locmaxwin - bufsize : 0);
7859 * If we're either buffering way too much data, or if we're
7860 * buffering anything at all and we're in "simple" mode,
7861 * throttle the whole channel.
7863 if ((bufsize > c->v.v2.locmaxwin || (ssh_is_simple(ssh) && bufsize>0))
7864 && !c->throttling_conn) {
7865 c->throttling_conn = 1;
7866 ssh_throttle_conn(ssh, +1);
7871 static void ssh_check_termination(Ssh ssh)
7873 if (ssh->version == 2 &&
7874 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
7875 (ssh->channels && count234(ssh->channels) == 0) &&
7876 !(ssh->connshare && share_ndownstreams(ssh->connshare) > 0)) {
7878 * We used to send SSH_MSG_DISCONNECT here, because I'd
7879 * believed that _every_ conforming SSH-2 connection had to
7880 * end with a disconnect being sent by at least one side;
7881 * apparently I was wrong and it's perfectly OK to
7882 * unceremoniously slam the connection shut when you're done,
7883 * and indeed OpenSSH feels this is more polite than sending a
7884 * DISCONNECT. So now we don't.
7886 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
7890 void ssh_sharing_downstream_connected(Ssh ssh, unsigned id,
7891 const char *peerinfo)
7894 logeventf(ssh, "Connection sharing downstream #%u connected from %s",
7897 logeventf(ssh, "Connection sharing downstream #%u connected", id);
7900 void ssh_sharing_downstream_disconnected(Ssh ssh, unsigned id)
7902 logeventf(ssh, "Connection sharing downstream #%u disconnected", id);
7903 ssh_check_termination(ssh);
7906 void ssh_sharing_logf(Ssh ssh, unsigned id, const char *logfmt, ...)
7911 va_start(ap, logfmt);
7912 buf = dupvprintf(logfmt, ap);
7915 logeventf(ssh, "Connection sharing downstream #%u: %s", id, buf);
7917 logeventf(ssh, "Connection sharing: %s", buf);
7921 static void ssh_channel_destroy(struct ssh_channel *c)
7926 case CHAN_MAINSESSION:
7927 ssh->mainchan = NULL;
7928 update_specials_menu(ssh->frontend);
7931 if (c->u.x11.xconn != NULL)
7932 x11_close(c->u.x11.xconn);
7933 logevent("Forwarded X11 connection terminated");
7936 sfree(c->u.a.message);
7939 if (c->u.pfd.pf != NULL)
7940 pfd_close(c->u.pfd.pf);
7941 logevent("Forwarded port closed");
7945 del234(ssh->channels, c);
7946 if (ssh->version == 2) {
7947 bufchain_clear(&c->v.v2.outbuffer);
7948 assert(c->v.v2.chanreq_head == NULL);
7953 * If that was the last channel left open, we might need to
7956 ssh_check_termination(ssh);
7959 static void ssh2_channel_check_close(struct ssh_channel *c)
7962 struct Packet *pktout;
7966 * If we've sent out our own CHANNEL_OPEN but not yet seen
7967 * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
7968 * it's too early to be sending close messages of any kind.
7973 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
7974 c->type == CHAN_ZOMBIE) &&
7975 !c->v.v2.chanreq_head &&
7976 !(c->closes & CLOSES_SENT_CLOSE)) {
7978 * We have both sent and received EOF (or the channel is a
7979 * zombie), and we have no outstanding channel requests, which
7980 * means the channel is in final wind-up. But we haven't sent
7981 * CLOSE, so let's do so now.
7983 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
7984 ssh2_pkt_adduint32(pktout, c->remoteid);
7985 ssh2_pkt_send(ssh, pktout);
7986 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
7989 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
7990 assert(c->v.v2.chanreq_head == NULL);
7992 * We have both sent and received CLOSE, which means we're
7993 * completely done with the channel.
7995 ssh_channel_destroy(c);
7999 static void ssh2_channel_got_eof(struct ssh_channel *c)
8001 if (c->closes & CLOSES_RCVD_EOF)
8002 return; /* already seen EOF */
8003 c->closes |= CLOSES_RCVD_EOF;
8005 if (c->type == CHAN_X11) {
8006 x11_send_eof(c->u.x11.xconn);
8007 } else if (c->type == CHAN_AGENT) {
8008 if (c->u.a.outstanding_requests == 0) {
8009 /* Manufacture an outgoing EOF in response to the incoming one. */
8010 sshfwd_write_eof(c);
8012 } else if (c->type == CHAN_SOCKDATA) {
8013 pfd_send_eof(c->u.pfd.pf);
8014 } else if (c->type == CHAN_MAINSESSION) {
8017 if (!ssh->sent_console_eof &&
8018 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
8020 * Either from_backend_eof told us that the front end
8021 * wants us to close the outgoing side of the connection
8022 * as soon as we see EOF from the far end, or else we've
8023 * unilaterally decided to do that because we've allocated
8024 * a remote pty and hence EOF isn't a particularly
8025 * meaningful concept.
8027 sshfwd_write_eof(c);
8029 ssh->sent_console_eof = TRUE;
8032 ssh2_channel_check_close(c);
8035 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
8037 struct ssh_channel *c;
8039 c = ssh2_channel_msg(ssh, pktin);
8042 if (c->type == CHAN_SHARING) {
8043 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8044 pktin->body, pktin->length);
8047 ssh2_channel_got_eof(c);
8050 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
8052 struct ssh_channel *c;
8054 c = ssh2_channel_msg(ssh, pktin);
8057 if (c->type == CHAN_SHARING) {
8058 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8059 pktin->body, pktin->length);
8064 * When we receive CLOSE on a channel, we assume it comes with an
8065 * implied EOF if we haven't seen EOF yet.
8067 ssh2_channel_got_eof(c);
8069 if (!(ssh->remote_bugs & BUG_SENDS_LATE_REQUEST_REPLY)) {
8071 * It also means we stop expecting to see replies to any
8072 * outstanding channel requests, so clean those up too.
8073 * (ssh_chanreq_init will enforce by assertion that we don't
8074 * subsequently put anything back on this list.)
8076 while (c->v.v2.chanreq_head) {
8077 struct outstanding_channel_request *ocr = c->v.v2.chanreq_head;
8078 ocr->handler(c, NULL, ocr->ctx);
8079 c->v.v2.chanreq_head = ocr->next;
8085 * And we also send an outgoing EOF, if we haven't already, on the
8086 * assumption that CLOSE is a pretty forceful announcement that
8087 * the remote side is doing away with the entire channel. (If it
8088 * had wanted to send us EOF and continue receiving data from us,
8089 * it would have just sent CHANNEL_EOF.)
8091 if (!(c->closes & CLOSES_SENT_EOF)) {
8093 * Make sure we don't read any more from whatever our local
8094 * data source is for this channel.
8097 case CHAN_MAINSESSION:
8098 ssh->send_ok = 0; /* stop trying to read from stdin */
8101 x11_override_throttle(c->u.x11.xconn, 1);
8104 pfd_override_throttle(c->u.pfd.pf, 1);
8109 * Abandon any buffered data we still wanted to send to this
8110 * channel. Receiving a CHANNEL_CLOSE is an indication that
8111 * the server really wants to get on and _destroy_ this
8112 * channel, and it isn't going to send us any further
8113 * WINDOW_ADJUSTs to permit us to send pending stuff.
8115 bufchain_clear(&c->v.v2.outbuffer);
8118 * Send outgoing EOF.
8120 sshfwd_write_eof(c);
8124 * Now process the actual close.
8126 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
8127 c->closes |= CLOSES_RCVD_CLOSE;
8128 ssh2_channel_check_close(c);
8132 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
8134 struct ssh_channel *c;
8136 c = ssh2_channel_msg(ssh, pktin);
8139 if (c->type == CHAN_SHARING) {
8140 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8141 pktin->body, pktin->length);
8144 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
8145 c->remoteid = ssh_pkt_getuint32(pktin);
8146 c->halfopen = FALSE;
8147 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8148 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
8150 if (c->type == CHAN_SOCKDATA_DORMANT) {
8151 c->type = CHAN_SOCKDATA;
8153 pfd_confirm(c->u.pfd.pf);
8154 } else if (c->type == CHAN_ZOMBIE) {
8156 * This case can occur if a local socket error occurred
8157 * between us sending out CHANNEL_OPEN and receiving
8158 * OPEN_CONFIRMATION. In this case, all we can do is
8159 * immediately initiate close proceedings now that we know the
8160 * server's id to put in the close message.
8162 ssh2_channel_check_close(c);
8165 * We never expect to receive OPEN_CONFIRMATION for any
8166 * *other* channel type (since only local-to-remote port
8167 * forwardings cause us to send CHANNEL_OPEN after the main
8168 * channel is live - all other auxiliary channel types are
8169 * initiated from the server end). It's safe to enforce this
8170 * by assertion rather than by ssh_disconnect, because the
8171 * real point is that we never constructed a half-open channel
8172 * structure in the first place with any type other than the
8175 assert(!"Funny channel type in ssh2_msg_channel_open_confirmation");
8179 ssh_channel_try_eof(c); /* in case we had a pending EOF */
8182 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
8184 static const char *const reasons[] = {
8185 "<unknown reason code>",
8186 "Administratively prohibited",
8188 "Unknown channel type",
8189 "Resource shortage",
8191 unsigned reason_code;
8192 char *reason_string;
8194 struct ssh_channel *c;
8196 c = ssh2_channel_msg(ssh, pktin);
8199 if (c->type == CHAN_SHARING) {
8200 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8201 pktin->body, pktin->length);
8204 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
8206 if (c->type == CHAN_SOCKDATA_DORMANT) {
8207 reason_code = ssh_pkt_getuint32(pktin);
8208 if (reason_code >= lenof(reasons))
8209 reason_code = 0; /* ensure reasons[reason_code] in range */
8210 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
8211 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
8212 reasons[reason_code], reason_length, reason_string);
8214 pfd_close(c->u.pfd.pf);
8215 } else if (c->type == CHAN_ZOMBIE) {
8217 * This case can occur if a local socket error occurred
8218 * between us sending out CHANNEL_OPEN and receiving
8219 * OPEN_FAILURE. In this case, we need do nothing except allow
8220 * the code below to throw the half-open channel away.
8224 * We never expect to receive OPEN_FAILURE for any *other*
8225 * channel type (since only local-to-remote port forwardings
8226 * cause us to send CHANNEL_OPEN after the main channel is
8227 * live - all other auxiliary channel types are initiated from
8228 * the server end). It's safe to enforce this by assertion
8229 * rather than by ssh_disconnect, because the real point is
8230 * that we never constructed a half-open channel structure in
8231 * the first place with any type other than the above.
8233 assert(!"Funny channel type in ssh2_msg_channel_open_failure");
8236 del234(ssh->channels, c);
8240 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
8243 int typelen, want_reply;
8244 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
8245 struct ssh_channel *c;
8246 struct Packet *pktout;
8248 c = ssh2_channel_msg(ssh, pktin);
8251 if (c->type == CHAN_SHARING) {
8252 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8253 pktin->body, pktin->length);
8256 ssh_pkt_getstring(pktin, &type, &typelen);
8257 want_reply = ssh2_pkt_getbool(pktin);
8259 if (c->closes & CLOSES_SENT_CLOSE) {
8261 * We don't reply to channel requests after we've sent
8262 * CHANNEL_CLOSE for the channel, because our reply might
8263 * cross in the network with the other side's CHANNEL_CLOSE
8264 * and arrive after they have wound the channel up completely.
8270 * Having got the channel number, we now look at
8271 * the request type string to see if it's something
8274 if (c == ssh->mainchan) {
8276 * We recognise "exit-status" and "exit-signal" on
8277 * the primary channel.
8279 if (typelen == 11 &&
8280 !memcmp(type, "exit-status", 11)) {
8282 ssh->exitcode = ssh_pkt_getuint32(pktin);
8283 logeventf(ssh, "Server sent command exit status %d",
8285 reply = SSH2_MSG_CHANNEL_SUCCESS;
8287 } else if (typelen == 11 &&
8288 !memcmp(type, "exit-signal", 11)) {
8290 int is_plausible = TRUE, is_int = FALSE;
8291 char *fmt_sig = NULL, *fmt_msg = NULL;
8293 int msglen = 0, core = FALSE;
8294 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
8295 * provide an `int' for the signal, despite its
8296 * having been a `string' in the drafts of RFC 4254 since at
8297 * least 2001. (Fixed in session.c 1.147.) Try to
8298 * infer which we can safely parse it as. */
8300 unsigned char *p = pktin->body +
8302 long len = pktin->length - pktin->savedpos;
8303 unsigned long num = GET_32BIT(p); /* what is it? */
8304 /* If it's 0, it hardly matters; assume string */
8308 int maybe_int = FALSE, maybe_str = FALSE;
8309 #define CHECK_HYPOTHESIS(offset, result) \
8312 int q = toint(offset); \
8313 if (q >= 0 && q+4 <= len) { \
8314 q = toint(q + 4 + GET_32BIT(p+q)); \
8315 if (q >= 0 && q+4 <= len && \
8316 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
8321 CHECK_HYPOTHESIS(4+1, maybe_int);
8322 CHECK_HYPOTHESIS(4+num+1, maybe_str);
8323 #undef CHECK_HYPOTHESIS
8324 if (maybe_int && !maybe_str)
8326 else if (!maybe_int && maybe_str)
8329 /* Crikey. Either or neither. Panic. */
8330 is_plausible = FALSE;
8333 ssh->exitcode = 128; /* means `unknown signal' */
8336 /* Old non-standard OpenSSH. */
8337 int signum = ssh_pkt_getuint32(pktin);
8338 fmt_sig = dupprintf(" %d", signum);
8339 ssh->exitcode = 128 + signum;
8341 /* As per RFC 4254. */
8344 ssh_pkt_getstring(pktin, &sig, &siglen);
8345 /* Signal name isn't supposed to be blank, but
8346 * let's cope gracefully if it is. */
8348 fmt_sig = dupprintf(" \"%.*s\"",
8353 * Really hideous method of translating the
8354 * signal description back into a locally
8355 * meaningful number.
8360 #define TRANSLATE_SIGNAL(s) \
8361 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
8362 ssh->exitcode = 128 + SIG ## s
8364 TRANSLATE_SIGNAL(ABRT);
8367 TRANSLATE_SIGNAL(ALRM);
8370 TRANSLATE_SIGNAL(FPE);
8373 TRANSLATE_SIGNAL(HUP);
8376 TRANSLATE_SIGNAL(ILL);
8379 TRANSLATE_SIGNAL(INT);
8382 TRANSLATE_SIGNAL(KILL);
8385 TRANSLATE_SIGNAL(PIPE);
8388 TRANSLATE_SIGNAL(QUIT);
8391 TRANSLATE_SIGNAL(SEGV);
8394 TRANSLATE_SIGNAL(TERM);
8397 TRANSLATE_SIGNAL(USR1);
8400 TRANSLATE_SIGNAL(USR2);
8402 #undef TRANSLATE_SIGNAL
8404 ssh->exitcode = 128;
8406 core = ssh2_pkt_getbool(pktin);
8407 ssh_pkt_getstring(pktin, &msg, &msglen);
8409 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
8411 /* ignore lang tag */
8412 } /* else don't attempt to parse */
8413 logeventf(ssh, "Server exited on signal%s%s%s",
8414 fmt_sig ? fmt_sig : "",
8415 core ? " (core dumped)" : "",
8416 fmt_msg ? fmt_msg : "");
8419 reply = SSH2_MSG_CHANNEL_SUCCESS;
8424 * This is a channel request we don't know
8425 * about, so we now either ignore the request
8426 * or respond with CHANNEL_FAILURE, depending
8429 reply = SSH2_MSG_CHANNEL_FAILURE;
8432 pktout = ssh2_pkt_init(reply);
8433 ssh2_pkt_adduint32(pktout, c->remoteid);
8434 ssh2_pkt_send(ssh, pktout);
8438 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
8441 int typelen, want_reply;
8442 struct Packet *pktout;
8444 ssh_pkt_getstring(pktin, &type, &typelen);
8445 want_reply = ssh2_pkt_getbool(pktin);
8448 * We currently don't support any global requests
8449 * at all, so we either ignore the request or
8450 * respond with REQUEST_FAILURE, depending on
8454 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
8455 ssh2_pkt_send(ssh, pktout);
8459 struct X11FakeAuth *ssh_sharing_add_x11_display(Ssh ssh, int authtype,
8463 struct X11FakeAuth *auth;
8466 * Make up a new set of fake X11 auth data, and add it to the tree
8467 * of currently valid ones with an indication of the sharing
8468 * context that it's relevant to.
8470 auth = x11_invent_fake_auth(ssh->x11authtree, authtype);
8471 auth->share_cs = share_cs;
8472 auth->share_chan = share_chan;
8477 void ssh_sharing_remove_x11_display(Ssh ssh, struct X11FakeAuth *auth)
8479 del234(ssh->x11authtree, auth);
8480 x11_free_fake_auth(auth);
8483 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
8490 const char *error = NULL;
8491 struct ssh_channel *c;
8492 unsigned remid, winsize, pktsize;
8493 unsigned our_winsize_override = 0;
8494 struct Packet *pktout;
8496 ssh_pkt_getstring(pktin, &type, &typelen);
8497 c = snew(struct ssh_channel);
8500 remid = ssh_pkt_getuint32(pktin);
8501 winsize = ssh_pkt_getuint32(pktin);
8502 pktsize = ssh_pkt_getuint32(pktin);
8504 if (typelen == 3 && !memcmp(type, "x11", 3)) {
8507 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8508 addrstr = snewn(peeraddrlen+1, char);
8509 memcpy(addrstr, peeraddr, peeraddrlen);
8510 addrstr[peeraddrlen] = '\0';
8511 peerport = ssh_pkt_getuint32(pktin);
8513 logeventf(ssh, "Received X11 connect request from %s:%d",
8516 if (!ssh->X11_fwd_enabled && !ssh->connshare)
8517 error = "X11 forwarding is not enabled";
8519 c->u.x11.xconn = x11_init(ssh->x11authtree, c,
8522 c->u.x11.initial = TRUE;
8525 * If we are a connection-sharing upstream, then we should
8526 * initially present a very small window, adequate to take
8527 * the X11 initial authorisation packet but not much more.
8528 * Downstream will then present us a larger window (by
8529 * fiat of the connection-sharing protocol) and we can
8530 * guarantee to send a positive-valued WINDOW_ADJUST.
8533 our_winsize_override = 128;
8535 logevent("Opened X11 forward channel");
8539 } else if (typelen == 15 &&
8540 !memcmp(type, "forwarded-tcpip", 15)) {
8541 struct ssh_rportfwd pf, *realpf;
8544 ssh_pkt_getstring(pktin, &shost, &shostlen);/* skip address */
8545 pf.shost = dupprintf("%.*s", shostlen, shost);
8546 pf.sport = ssh_pkt_getuint32(pktin);
8547 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8548 peerport = ssh_pkt_getuint32(pktin);
8549 realpf = find234(ssh->rportfwds, &pf, NULL);
8550 logeventf(ssh, "Received remote port %s:%d open request "
8551 "from %s:%d", pf.shost, pf.sport, peeraddr, peerport);
8554 if (realpf == NULL) {
8555 error = "Remote port is not recognised";
8559 if (realpf->share_ctx) {
8561 * This port forwarding is on behalf of a
8562 * connection-sharing downstream, so abandon our own
8563 * channel-open procedure and just pass the message on
8566 share_got_pkt_from_server(realpf->share_ctx, pktin->type,
8567 pktin->body, pktin->length);
8572 err = pfd_connect(&c->u.pfd.pf, realpf->dhost, realpf->dport,
8573 c, ssh->conf, realpf->pfrec->addressfamily);
8574 logeventf(ssh, "Attempting to forward remote port to "
8575 "%s:%d", realpf->dhost, realpf->dport);
8577 logeventf(ssh, "Port open failed: %s", err);
8579 error = "Port open failed";
8581 logevent("Forwarded port opened successfully");
8582 c->type = CHAN_SOCKDATA;
8585 } else if (typelen == 22 &&
8586 !memcmp(type, "auth-agent@openssh.com", 22)) {
8587 if (!ssh->agentfwd_enabled)
8588 error = "Agent forwarding is not enabled";
8590 c->type = CHAN_AGENT; /* identify channel type */
8591 c->u.a.lensofar = 0;
8592 c->u.a.message = NULL;
8593 c->u.a.outstanding_requests = 0;
8596 error = "Unsupported channel type requested";
8599 c->remoteid = remid;
8600 c->halfopen = FALSE;
8602 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
8603 ssh2_pkt_adduint32(pktout, c->remoteid);
8604 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
8605 ssh2_pkt_addstring(pktout, error);
8606 ssh2_pkt_addstring(pktout, "en"); /* language tag */
8607 ssh2_pkt_send(ssh, pktout);
8608 logeventf(ssh, "Rejected channel open: %s", error);
8611 ssh2_channel_init(c);
8612 c->v.v2.remwindow = winsize;
8613 c->v.v2.remmaxpkt = pktsize;
8614 if (our_winsize_override) {
8615 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
8616 our_winsize_override;
8618 add234(ssh->channels, c);
8619 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
8620 ssh2_pkt_adduint32(pktout, c->remoteid);
8621 ssh2_pkt_adduint32(pktout, c->localid);
8622 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
8623 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8624 ssh2_pkt_send(ssh, pktout);
8628 void sshfwd_x11_sharing_handover(struct ssh_channel *c,
8629 void *share_cs, void *share_chan,
8630 const char *peer_addr, int peer_port,
8631 int endian, int protomajor, int protominor,
8632 const void *initial_data, int initial_len)
8635 * This function is called when we've just discovered that an X
8636 * forwarding channel on which we'd been handling the initial auth
8637 * ourselves turns out to be destined for a connection-sharing
8638 * downstream. So we turn the channel into a CHAN_SHARING, meaning
8639 * that we completely stop tracking windows and buffering data and
8640 * just pass more or less unmodified SSH messages back and forth.
8642 c->type = CHAN_SHARING;
8643 c->u.sharing.ctx = share_cs;
8644 share_setup_x11_channel(share_cs, share_chan,
8645 c->localid, c->remoteid, c->v.v2.remwindow,
8646 c->v.v2.remmaxpkt, c->v.v2.locwindow,
8647 peer_addr, peer_port, endian,
8648 protomajor, protominor,
8649 initial_data, initial_len);
8652 void sshfwd_x11_is_local(struct ssh_channel *c)
8655 * This function is called when we've just discovered that an X
8656 * forwarding channel is _not_ destined for a connection-sharing
8657 * downstream but we're going to handle it ourselves. We stop
8658 * presenting a cautiously small window and go into ordinary data
8661 c->u.x11.initial = FALSE;
8662 ssh2_set_window(c, ssh_is_simple(c->ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE);
8666 * Buffer banner messages for later display at some convenient point,
8667 * if we're going to display them.
8669 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
8671 /* Arbitrary limit to prevent unbounded inflation of buffer */
8672 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
8673 bufchain_size(&ssh->banner) <= 131072) {
8674 char *banner = NULL;
8676 ssh_pkt_getstring(pktin, &banner, &size);
8678 bufchain_add(&ssh->banner, banner, size);
8682 /* Helper function to deal with sending tty modes for "pty-req" */
8683 static void ssh2_send_ttymode(void *data, char *mode, char *val)
8685 struct Packet *pktout = (struct Packet *)data;
8687 unsigned int arg = 0;
8688 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
8689 if (i == lenof(ssh_ttymodes)) return;
8690 switch (ssh_ttymodes[i].type) {
8692 arg = ssh_tty_parse_specchar(val);
8695 arg = ssh_tty_parse_boolean(val);
8698 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
8699 ssh2_pkt_adduint32(pktout, arg);
8702 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
8705 struct ssh2_setup_x11_state {
8709 struct Packet *pktout;
8710 crStateP(ssh2_setup_x11_state, ctx);
8714 logevent("Requesting X11 forwarding");
8715 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
8717 ssh2_pkt_addbool(pktout, 0); /* many connections */
8718 ssh2_pkt_addstring(pktout, ssh->x11auth->protoname);
8719 ssh2_pkt_addstring(pktout, ssh->x11auth->datastring);
8720 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
8721 ssh2_pkt_send(ssh, pktout);
8723 /* Wait to be called back with either a response packet, or NULL
8724 * meaning clean up and free our data */
8728 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8729 logevent("X11 forwarding enabled");
8730 ssh->X11_fwd_enabled = TRUE;
8732 logevent("X11 forwarding refused");
8738 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
8741 struct ssh2_setup_agent_state {
8745 struct Packet *pktout;
8746 crStateP(ssh2_setup_agent_state, ctx);
8750 logevent("Requesting OpenSSH-style agent forwarding");
8751 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
8752 ssh2_setup_agent, s);
8753 ssh2_pkt_send(ssh, pktout);
8755 /* Wait to be called back with either a response packet, or NULL
8756 * meaning clean up and free our data */
8760 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8761 logevent("Agent forwarding enabled");
8762 ssh->agentfwd_enabled = TRUE;
8764 logevent("Agent forwarding refused");
8770 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
8773 struct ssh2_setup_pty_state {
8777 struct Packet *pktout;
8778 crStateP(ssh2_setup_pty_state, ctx);
8782 /* Unpick the terminal-speed string. */
8783 /* XXX perhaps we should allow no speeds to be sent. */
8784 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
8785 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
8786 /* Build the pty request. */
8787 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
8789 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
8790 ssh2_pkt_adduint32(pktout, ssh->term_width);
8791 ssh2_pkt_adduint32(pktout, ssh->term_height);
8792 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
8793 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
8794 ssh2_pkt_addstring_start(pktout);
8795 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
8796 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
8797 ssh2_pkt_adduint32(pktout, ssh->ispeed);
8798 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
8799 ssh2_pkt_adduint32(pktout, ssh->ospeed);
8800 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
8801 ssh2_pkt_send(ssh, pktout);
8802 ssh->state = SSH_STATE_INTERMED;
8804 /* Wait to be called back with either a response packet, or NULL
8805 * meaning clean up and free our data */
8809 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8810 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
8811 ssh->ospeed, ssh->ispeed);
8812 ssh->got_pty = TRUE;
8814 c_write_str(ssh, "Server refused to allocate pty\r\n");
8815 ssh->editing = ssh->echoing = 1;
8822 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
8825 struct ssh2_setup_env_state {
8827 int num_env, env_left, env_ok;
8830 struct Packet *pktout;
8831 crStateP(ssh2_setup_env_state, ctx);
8836 * Send environment variables.
8838 * Simplest thing here is to send all the requests at once, and
8839 * then wait for a whole bunch of successes or failures.
8845 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
8847 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
8848 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
8849 ssh2_pkt_addstring(pktout, key);
8850 ssh2_pkt_addstring(pktout, val);
8851 ssh2_pkt_send(ssh, pktout);
8856 logeventf(ssh, "Sent %d environment variables", s->num_env);
8861 s->env_left = s->num_env;
8863 while (s->env_left > 0) {
8864 /* Wait to be called back with either a response packet,
8865 * or NULL meaning clean up and free our data */
8867 if (!pktin) goto out;
8868 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
8873 if (s->env_ok == s->num_env) {
8874 logevent("All environment variables successfully set");
8875 } else if (s->env_ok == 0) {
8876 logevent("All environment variables refused");
8877 c_write_str(ssh, "Server refused to set environment variables\r\n");
8879 logeventf(ssh, "%d environment variables refused",
8880 s->num_env - s->env_ok);
8881 c_write_str(ssh, "Server refused to set all environment variables\r\n");
8889 * Handle the SSH-2 userauth and connection layers.
8891 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
8893 do_ssh2_authconn(ssh, NULL, 0, pktin);
8896 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
8900 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
8903 static void do_ssh2_authconn(Ssh ssh, const unsigned char *in, int inlen,
8904 struct Packet *pktin)
8906 struct do_ssh2_authconn_state {
8910 AUTH_TYPE_PUBLICKEY,
8911 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
8912 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
8914 AUTH_TYPE_GSSAPI, /* always QUIET */
8915 AUTH_TYPE_KEYBOARD_INTERACTIVE,
8916 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
8918 int done_service_req;
8919 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
8920 int tried_pubkey_config, done_agent;
8925 int kbd_inter_refused;
8926 int we_are_in, userauth_success;
8927 prompts_t *cur_prompt;
8932 void *publickey_blob;
8933 int publickey_bloblen;
8934 int privatekey_available, privatekey_encrypted;
8935 char *publickey_algorithm;
8936 char *publickey_comment;
8937 unsigned char agent_request[5], *agent_response, *agentp;
8938 int agent_responselen;
8939 unsigned char *pkblob_in_agent;
8941 char *pkblob, *alg, *commentp;
8942 int pklen, alglen, commentlen;
8943 int siglen, retlen, len;
8944 char *q, *agentreq, *ret;
8946 struct Packet *pktout;
8949 struct ssh_gss_library *gsslib;
8950 Ssh_gss_ctx gss_ctx;
8951 Ssh_gss_buf gss_buf;
8952 Ssh_gss_buf gss_rcvtok, gss_sndtok;
8953 Ssh_gss_name gss_srv_name;
8954 Ssh_gss_stat gss_stat;
8957 crState(do_ssh2_authconn_state);
8961 /* Register as a handler for all the messages this coroutine handles. */
8962 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
8963 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
8964 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
8965 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
8966 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
8967 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
8968 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
8969 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
8970 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
8971 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
8972 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
8973 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
8974 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
8975 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
8976 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
8977 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
8978 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
8979 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
8980 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
8981 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
8983 s->done_service_req = FALSE;
8984 s->we_are_in = s->userauth_success = FALSE;
8985 s->agent_response = NULL;
8987 s->tried_gssapi = FALSE;
8990 if (!ssh->bare_connection) {
8991 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
8993 * Request userauth protocol, and await a response to it.
8995 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8996 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
8997 ssh2_pkt_send(ssh, s->pktout);
8998 crWaitUntilV(pktin);
8999 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
9000 s->done_service_req = TRUE;
9002 if (!s->done_service_req) {
9004 * Request connection protocol directly, without authentication.
9006 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
9007 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9008 ssh2_pkt_send(ssh, s->pktout);
9009 crWaitUntilV(pktin);
9010 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
9011 s->we_are_in = TRUE; /* no auth required */
9013 bombout(("Server refused service request"));
9018 s->we_are_in = TRUE;
9021 /* Arrange to be able to deal with any BANNERs that come in.
9022 * (We do this now as packets may come in during the next bit.) */
9023 bufchain_init(&ssh->banner);
9024 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
9025 ssh2_msg_userauth_banner;
9028 * Misc one-time setup for authentication.
9030 s->publickey_blob = NULL;
9031 if (!s->we_are_in) {
9034 * Load the public half of any configured public key file
9037 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9038 if (!filename_is_null(s->keyfile)) {
9040 logeventf(ssh, "Reading key file \"%.150s\"",
9041 filename_to_str(s->keyfile));
9042 keytype = key_type(s->keyfile);
9043 if (keytype == SSH_KEYTYPE_SSH2 ||
9044 keytype == SSH_KEYTYPE_SSH2_PUBLIC_RFC4716 ||
9045 keytype == SSH_KEYTYPE_SSH2_PUBLIC_OPENSSH) {
9048 ssh2_userkey_loadpub(s->keyfile,
9049 &s->publickey_algorithm,
9050 &s->publickey_bloblen,
9051 &s->publickey_comment, &error);
9052 if (s->publickey_blob) {
9053 s->privatekey_available = (keytype == SSH_KEYTYPE_SSH2);
9054 if (!s->privatekey_available)
9055 logeventf(ssh, "Key file contains public key only");
9056 s->privatekey_encrypted =
9057 ssh2_userkey_encrypted(s->keyfile, NULL);
9060 logeventf(ssh, "Unable to load key (%s)",
9062 msgbuf = dupprintf("Unable to load key file "
9063 "\"%.150s\" (%s)\r\n",
9064 filename_to_str(s->keyfile),
9066 c_write_str(ssh, msgbuf);
9071 logeventf(ssh, "Unable to use this key file (%s)",
9072 key_type_to_str(keytype));
9073 msgbuf = dupprintf("Unable to use key file \"%.150s\""
9075 filename_to_str(s->keyfile),
9076 key_type_to_str(keytype));
9077 c_write_str(ssh, msgbuf);
9079 s->publickey_blob = NULL;
9084 * Find out about any keys Pageant has (but if there's a
9085 * public key configured, filter out all others).
9088 s->agent_response = NULL;
9089 s->pkblob_in_agent = NULL;
9090 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
9094 logevent("Pageant is running. Requesting keys.");
9096 /* Request the keys held by the agent. */
9097 PUT_32BIT(s->agent_request, 1);
9098 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
9099 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
9100 ssh_agent_callback, ssh)) {
9104 bombout(("Unexpected data from server while"
9105 " waiting for agent response"));
9108 } while (pktin || inlen > 0);
9109 r = ssh->agent_response;
9110 s->agent_responselen = ssh->agent_response_len;
9112 s->agent_response = (unsigned char *) r;
9113 if (s->agent_response && s->agent_responselen >= 5 &&
9114 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
9117 p = s->agent_response + 5;
9118 s->nkeys = toint(GET_32BIT(p));
9121 * Vet the Pageant response to ensure that the key
9122 * count and blob lengths make sense.
9125 logeventf(ssh, "Pageant response contained a negative"
9126 " key count %d", s->nkeys);
9128 goto done_agent_query;
9130 unsigned char *q = p + 4;
9131 int lenleft = s->agent_responselen - 5 - 4;
9133 for (keyi = 0; keyi < s->nkeys; keyi++) {
9134 int bloblen, commentlen;
9136 logeventf(ssh, "Pageant response was truncated");
9138 goto done_agent_query;
9140 bloblen = toint(GET_32BIT(q));
9141 if (bloblen < 0 || bloblen > lenleft) {
9142 logeventf(ssh, "Pageant response was truncated");
9144 goto done_agent_query;
9146 lenleft -= 4 + bloblen;
9148 commentlen = toint(GET_32BIT(q));
9149 if (commentlen < 0 || commentlen > lenleft) {
9150 logeventf(ssh, "Pageant response was truncated");
9152 goto done_agent_query;
9154 lenleft -= 4 + commentlen;
9155 q += 4 + commentlen;
9160 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
9161 if (s->publickey_blob) {
9162 /* See if configured key is in agent. */
9163 for (keyi = 0; keyi < s->nkeys; keyi++) {
9164 s->pklen = toint(GET_32BIT(p));
9165 if (s->pklen == s->publickey_bloblen &&
9166 !memcmp(p+4, s->publickey_blob,
9167 s->publickey_bloblen)) {
9168 logeventf(ssh, "Pageant key #%d matches "
9169 "configured key file", keyi);
9171 s->pkblob_in_agent = p;
9175 p += toint(GET_32BIT(p)) + 4; /* comment */
9177 if (!s->pkblob_in_agent) {
9178 logevent("Configured key file not in Pageant");
9183 logevent("Failed to get reply from Pageant");
9191 * We repeat this whole loop, including the username prompt,
9192 * until we manage a successful authentication. If the user
9193 * types the wrong _password_, they can be sent back to the
9194 * beginning to try another username, if this is configured on.
9195 * (If they specify a username in the config, they are never
9196 * asked, even if they do give a wrong password.)
9198 * I think this best serves the needs of
9200 * - the people who have no configuration, no keys, and just
9201 * want to try repeated (username,password) pairs until they
9202 * type both correctly
9204 * - people who have keys and configuration but occasionally
9205 * need to fall back to passwords
9207 * - people with a key held in Pageant, who might not have
9208 * logged in to a particular machine before; so they want to
9209 * type a username, and then _either_ their key will be
9210 * accepted, _or_ they will type a password. If they mistype
9211 * the username they will want to be able to get back and
9214 s->got_username = FALSE;
9215 while (!s->we_are_in) {
9219 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
9221 * We got a username last time round this loop, and
9222 * with change_username turned off we don't try to get
9225 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
9226 int ret; /* need not be kept over crReturn */
9227 s->cur_prompt = new_prompts(ssh->frontend);
9228 s->cur_prompt->to_server = TRUE;
9229 s->cur_prompt->name = dupstr("SSH login name");
9230 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
9231 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9234 crWaitUntilV(!pktin);
9235 ret = get_userpass_input(s->cur_prompt, in, inlen);
9240 * get_userpass_input() failed to get a username.
9243 free_prompts(s->cur_prompt);
9244 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
9247 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
9248 free_prompts(s->cur_prompt);
9251 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
9252 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
9253 c_write_str(ssh, stuff);
9257 s->got_username = TRUE;
9260 * Send an authentication request using method "none": (a)
9261 * just in case it succeeds, and (b) so that we know what
9262 * authentication methods we can usefully try next.
9264 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9266 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9267 ssh2_pkt_addstring(s->pktout, ssh->username);
9268 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
9269 ssh2_pkt_addstring(s->pktout, "none"); /* method */
9270 ssh2_pkt_send(ssh, s->pktout);
9271 s->type = AUTH_TYPE_NONE;
9273 s->we_are_in = FALSE;
9275 s->tried_pubkey_config = FALSE;
9276 s->kbd_inter_refused = FALSE;
9278 /* Reset agent request state. */
9279 s->done_agent = FALSE;
9280 if (s->agent_response) {
9281 if (s->pkblob_in_agent) {
9282 s->agentp = s->pkblob_in_agent;
9284 s->agentp = s->agent_response + 5 + 4;
9290 char *methods = NULL;
9294 * Wait for the result of the last authentication request.
9297 crWaitUntilV(pktin);
9299 * Now is a convenient point to spew any banner material
9300 * that we've accumulated. (This should ensure that when
9301 * we exit the auth loop, we haven't any left to deal
9305 int size = bufchain_size(&ssh->banner);
9307 * Don't show the banner if we're operating in
9308 * non-verbose non-interactive mode. (It's probably
9309 * a script, which means nobody will read the
9310 * banner _anyway_, and moreover the printing of
9311 * the banner will screw up processing on the
9312 * output of (say) plink.)
9314 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
9315 char *banner = snewn(size, char);
9316 bufchain_fetch(&ssh->banner, banner, size);
9317 c_write_untrusted(ssh, banner, size);
9320 bufchain_clear(&ssh->banner);
9322 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
9323 logevent("Access granted");
9324 s->we_are_in = s->userauth_success = TRUE;
9328 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
9329 bombout(("Strange packet received during authentication: "
9330 "type %d", pktin->type));
9337 * OK, we're now sitting on a USERAUTH_FAILURE message, so
9338 * we can look at the string in it and know what we can
9339 * helpfully try next.
9341 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
9342 ssh_pkt_getstring(pktin, &methods, &methlen);
9343 if (!ssh2_pkt_getbool(pktin)) {
9345 * We have received an unequivocal Access
9346 * Denied. This can translate to a variety of
9347 * messages, or no message at all.
9349 * For forms of authentication which are attempted
9350 * implicitly, by which I mean without printing
9351 * anything in the window indicating that we're
9352 * trying them, we should never print 'Access
9355 * If we do print a message saying that we're
9356 * attempting some kind of authentication, it's OK
9357 * to print a followup message saying it failed -
9358 * but the message may sometimes be more specific
9359 * than simply 'Access denied'.
9361 * Additionally, if we'd just tried password
9362 * authentication, we should break out of this
9363 * whole loop so as to go back to the username
9364 * prompt (iff we're configured to allow
9365 * username change attempts).
9367 if (s->type == AUTH_TYPE_NONE) {
9369 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
9370 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
9371 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
9372 c_write_str(ssh, "Server refused our key\r\n");
9373 logevent("Server refused our key");
9374 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
9375 /* This _shouldn't_ happen except by a
9376 * protocol bug causing client and server to
9377 * disagree on what is a correct signature. */
9378 c_write_str(ssh, "Server refused public-key signature"
9379 " despite accepting key!\r\n");
9380 logevent("Server refused public-key signature"
9381 " despite accepting key!");
9382 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
9383 /* quiet, so no c_write */
9384 logevent("Server refused keyboard-interactive authentication");
9385 } else if (s->type==AUTH_TYPE_GSSAPI) {
9386 /* always quiet, so no c_write */
9387 /* also, the code down in the GSSAPI block has
9388 * already logged this in the Event Log */
9389 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
9390 logevent("Keyboard-interactive authentication failed");
9391 c_write_str(ssh, "Access denied\r\n");
9393 assert(s->type == AUTH_TYPE_PASSWORD);
9394 logevent("Password authentication failed");
9395 c_write_str(ssh, "Access denied\r\n");
9397 if (conf_get_int(ssh->conf, CONF_change_username)) {
9398 /* XXX perhaps we should allow
9399 * keyboard-interactive to do this too? */
9400 s->we_are_in = FALSE;
9405 c_write_str(ssh, "Further authentication required\r\n");
9406 logevent("Further authentication required");
9410 in_commasep_string("publickey", methods, methlen);
9412 in_commasep_string("password", methods, methlen);
9413 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
9414 in_commasep_string("keyboard-interactive", methods, methlen);
9416 if (conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
9417 in_commasep_string("gssapi-with-mic", methods, methlen)) {
9418 /* Try loading the GSS libraries and see if we
9421 ssh->gsslibs = ssh_gss_setup(ssh->conf);
9422 s->can_gssapi = (ssh->gsslibs->nlibraries > 0);
9424 /* No point in even bothering to try to load the
9425 * GSS libraries, if the user configuration and
9426 * server aren't both prepared to attempt GSSAPI
9427 * auth in the first place. */
9428 s->can_gssapi = FALSE;
9433 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9435 if (s->can_pubkey && !s->done_agent && s->nkeys) {
9438 * Attempt public-key authentication using a key from Pageant.
9441 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9443 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
9445 /* Unpack key from agent response */
9446 s->pklen = toint(GET_32BIT(s->agentp));
9448 s->pkblob = (char *)s->agentp;
9449 s->agentp += s->pklen;
9450 s->alglen = toint(GET_32BIT(s->pkblob));
9451 s->alg = s->pkblob + 4;
9452 s->commentlen = toint(GET_32BIT(s->agentp));
9454 s->commentp = (char *)s->agentp;
9455 s->agentp += s->commentlen;
9456 /* s->agentp now points at next key, if any */
9458 /* See if server will accept it */
9459 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9460 ssh2_pkt_addstring(s->pktout, ssh->username);
9461 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9462 /* service requested */
9463 ssh2_pkt_addstring(s->pktout, "publickey");
9465 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
9466 ssh2_pkt_addstring_start(s->pktout);
9467 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9468 ssh2_pkt_addstring_start(s->pktout);
9469 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9470 ssh2_pkt_send(ssh, s->pktout);
9471 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
9473 crWaitUntilV(pktin);
9474 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9476 /* Offer of key refused. */
9483 if (flags & FLAG_VERBOSE) {
9484 c_write_str(ssh, "Authenticating with "
9486 c_write(ssh, s->commentp, s->commentlen);
9487 c_write_str(ssh, "\" from agent\r\n");
9491 * Server is willing to accept the key.
9492 * Construct a SIGN_REQUEST.
9494 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9495 ssh2_pkt_addstring(s->pktout, ssh->username);
9496 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9497 /* service requested */
9498 ssh2_pkt_addstring(s->pktout, "publickey");
9500 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
9501 ssh2_pkt_addstring_start(s->pktout);
9502 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9503 ssh2_pkt_addstring_start(s->pktout);
9504 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9506 /* Ask agent for signature. */
9507 s->siglen = s->pktout->length - 5 + 4 +
9508 ssh->v2_session_id_len;
9509 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9511 s->len = 1; /* message type */
9512 s->len += 4 + s->pklen; /* key blob */
9513 s->len += 4 + s->siglen; /* data to sign */
9514 s->len += 4; /* flags */
9515 s->agentreq = snewn(4 + s->len, char);
9516 PUT_32BIT(s->agentreq, s->len);
9517 s->q = s->agentreq + 4;
9518 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
9519 PUT_32BIT(s->q, s->pklen);
9521 memcpy(s->q, s->pkblob, s->pklen);
9523 PUT_32BIT(s->q, s->siglen);
9525 /* Now the data to be signed... */
9526 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9527 PUT_32BIT(s->q, ssh->v2_session_id_len);
9530 memcpy(s->q, ssh->v2_session_id,
9531 ssh->v2_session_id_len);
9532 s->q += ssh->v2_session_id_len;
9533 memcpy(s->q, s->pktout->data + 5,
9534 s->pktout->length - 5);
9535 s->q += s->pktout->length - 5;
9536 /* And finally the (zero) flags word. */
9538 if (!agent_query(s->agentreq, s->len + 4,
9540 ssh_agent_callback, ssh)) {
9544 bombout(("Unexpected data from server"
9545 " while waiting for agent"
9549 } while (pktin || inlen > 0);
9550 vret = ssh->agent_response;
9551 s->retlen = ssh->agent_response_len;
9556 if (s->retlen >= 9 &&
9557 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
9558 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
9559 logevent("Sending Pageant's response");
9560 ssh2_add_sigblob(ssh, s->pktout,
9561 s->pkblob, s->pklen,
9563 GET_32BIT(s->ret + 5));
9564 ssh2_pkt_send(ssh, s->pktout);
9565 s->type = AUTH_TYPE_PUBLICKEY;
9567 /* FIXME: less drastic response */
9568 bombout(("Pageant failed to answer challenge"));
9574 /* Do we have any keys left to try? */
9575 if (s->pkblob_in_agent) {
9576 s->done_agent = TRUE;
9577 s->tried_pubkey_config = TRUE;
9580 if (s->keyi >= s->nkeys)
9581 s->done_agent = TRUE;
9584 } else if (s->can_pubkey && s->publickey_blob &&
9585 s->privatekey_available && !s->tried_pubkey_config) {
9587 struct ssh2_userkey *key; /* not live over crReturn */
9588 char *passphrase; /* not live over crReturn */
9590 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9592 s->tried_pubkey_config = TRUE;
9595 * Try the public key supplied in the configuration.
9597 * First, offer the public blob to see if the server is
9598 * willing to accept it.
9600 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9601 ssh2_pkt_addstring(s->pktout, ssh->username);
9602 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9603 /* service requested */
9604 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
9605 ssh2_pkt_addbool(s->pktout, FALSE);
9606 /* no signature included */
9607 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
9608 ssh2_pkt_addstring_start(s->pktout);
9609 ssh2_pkt_addstring_data(s->pktout,
9610 (char *)s->publickey_blob,
9611 s->publickey_bloblen);
9612 ssh2_pkt_send(ssh, s->pktout);
9613 logevent("Offered public key");
9615 crWaitUntilV(pktin);
9616 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9617 /* Key refused. Give up. */
9618 s->gotit = TRUE; /* reconsider message next loop */
9619 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
9620 continue; /* process this new message */
9622 logevent("Offer of public key accepted");
9625 * Actually attempt a serious authentication using
9628 if (flags & FLAG_VERBOSE) {
9629 c_write_str(ssh, "Authenticating with public key \"");
9630 c_write_str(ssh, s->publickey_comment);
9631 c_write_str(ssh, "\"\r\n");
9635 const char *error; /* not live over crReturn */
9636 if (s->privatekey_encrypted) {
9638 * Get a passphrase from the user.
9640 int ret; /* need not be kept over crReturn */
9641 s->cur_prompt = new_prompts(ssh->frontend);
9642 s->cur_prompt->to_server = FALSE;
9643 s->cur_prompt->name = dupstr("SSH key passphrase");
9644 add_prompt(s->cur_prompt,
9645 dupprintf("Passphrase for key \"%.100s\": ",
9646 s->publickey_comment),
9648 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9651 crWaitUntilV(!pktin);
9652 ret = get_userpass_input(s->cur_prompt,
9657 /* Failed to get a passphrase. Terminate. */
9658 free_prompts(s->cur_prompt);
9659 ssh_disconnect(ssh, NULL,
9660 "Unable to authenticate",
9661 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9666 dupstr(s->cur_prompt->prompts[0]->result);
9667 free_prompts(s->cur_prompt);
9669 passphrase = NULL; /* no passphrase needed */
9673 * Try decrypting the key.
9675 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9676 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
9678 /* burn the evidence */
9679 smemclr(passphrase, strlen(passphrase));
9682 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
9684 (key == SSH2_WRONG_PASSPHRASE)) {
9685 c_write_str(ssh, "Wrong passphrase\r\n");
9687 /* and loop again */
9689 c_write_str(ssh, "Unable to load private key (");
9690 c_write_str(ssh, error);
9691 c_write_str(ssh, ")\r\n");
9693 break; /* try something else */
9699 unsigned char *pkblob, *sigblob, *sigdata;
9700 int pkblob_len, sigblob_len, sigdata_len;
9704 * We have loaded the private key and the server
9705 * has announced that it's willing to accept it.
9706 * Hallelujah. Generate a signature and send it.
9708 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9709 ssh2_pkt_addstring(s->pktout, ssh->username);
9710 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9711 /* service requested */
9712 ssh2_pkt_addstring(s->pktout, "publickey");
9714 ssh2_pkt_addbool(s->pktout, TRUE);
9715 /* signature follows */
9716 ssh2_pkt_addstring(s->pktout, key->alg->name);
9717 pkblob = key->alg->public_blob(key->data,
9719 ssh2_pkt_addstring_start(s->pktout);
9720 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
9724 * The data to be signed is:
9728 * followed by everything so far placed in the
9731 sigdata_len = s->pktout->length - 5 + 4 +
9732 ssh->v2_session_id_len;
9733 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9735 sigdata = snewn(sigdata_len, unsigned char);
9737 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9738 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
9741 memcpy(sigdata+p, ssh->v2_session_id,
9742 ssh->v2_session_id_len);
9743 p += ssh->v2_session_id_len;
9744 memcpy(sigdata+p, s->pktout->data + 5,
9745 s->pktout->length - 5);
9746 p += s->pktout->length - 5;
9747 assert(p == sigdata_len);
9748 sigblob = key->alg->sign(key->data, (char *)sigdata,
9749 sigdata_len, &sigblob_len);
9750 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
9751 sigblob, sigblob_len);
9756 ssh2_pkt_send(ssh, s->pktout);
9757 logevent("Sent public key signature");
9758 s->type = AUTH_TYPE_PUBLICKEY;
9759 key->alg->freekey(key->data);
9760 sfree(key->comment);
9765 } else if (s->can_gssapi && !s->tried_gssapi) {
9767 /* GSSAPI Authentication */
9772 s->type = AUTH_TYPE_GSSAPI;
9773 s->tried_gssapi = TRUE;
9775 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
9778 * Pick the highest GSS library on the preference
9784 for (i = 0; i < ngsslibs; i++) {
9785 int want_id = conf_get_int_int(ssh->conf,
9786 CONF_ssh_gsslist, i);
9787 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
9788 if (ssh->gsslibs->libraries[j].id == want_id) {
9789 s->gsslib = &ssh->gsslibs->libraries[j];
9790 goto got_gsslib; /* double break */
9795 * We always expect to have found something in
9796 * the above loop: we only came here if there
9797 * was at least one viable GSS library, and the
9798 * preference list should always mention
9799 * everything and only change the order.
9804 if (s->gsslib->gsslogmsg)
9805 logevent(s->gsslib->gsslogmsg);
9807 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
9808 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9809 ssh2_pkt_addstring(s->pktout, ssh->username);
9810 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9811 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
9812 logevent("Attempting GSSAPI authentication");
9814 /* add mechanism info */
9815 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
9817 /* number of GSSAPI mechanisms */
9818 ssh2_pkt_adduint32(s->pktout,1);
9820 /* length of OID + 2 */
9821 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
9822 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
9825 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
9827 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
9829 ssh2_pkt_send(ssh, s->pktout);
9830 crWaitUntilV(pktin);
9831 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
9832 logevent("GSSAPI authentication request refused");
9836 /* check returned packet ... */
9838 ssh_pkt_getstring(pktin, &data, &len);
9839 s->gss_rcvtok.value = data;
9840 s->gss_rcvtok.length = len;
9841 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
9842 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
9843 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
9844 memcmp((char *)s->gss_rcvtok.value + 2,
9845 s->gss_buf.value,s->gss_buf.length) ) {
9846 logevent("GSSAPI authentication - wrong response from server");
9850 /* now start running */
9851 s->gss_stat = s->gsslib->import_name(s->gsslib,
9854 if (s->gss_stat != SSH_GSS_OK) {
9855 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
9856 logevent("GSSAPI import name failed - Bad service name");
9858 logevent("GSSAPI import name failed");
9862 /* fetch TGT into GSS engine */
9863 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
9865 if (s->gss_stat != SSH_GSS_OK) {
9866 logevent("GSSAPI authentication failed to get credentials");
9867 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9871 /* initial tokens are empty */
9872 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
9873 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
9875 /* now enter the loop */
9877 s->gss_stat = s->gsslib->init_sec_context
9881 conf_get_int(ssh->conf, CONF_gssapifwd),
9885 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
9886 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
9887 logevent("GSSAPI authentication initialisation failed");
9889 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
9890 &s->gss_buf) == SSH_GSS_OK) {
9891 logevent(s->gss_buf.value);
9892 sfree(s->gss_buf.value);
9897 logevent("GSSAPI authentication initialised");
9899 /* Client and server now exchange tokens until GSSAPI
9900 * no longer says CONTINUE_NEEDED */
9902 if (s->gss_sndtok.length != 0) {
9903 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
9904 ssh_pkt_addstring_start(s->pktout);
9905 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
9906 ssh2_pkt_send(ssh, s->pktout);
9907 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
9910 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
9911 crWaitUntilV(pktin);
9912 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
9913 logevent("GSSAPI authentication - bad server response");
9914 s->gss_stat = SSH_GSS_FAILURE;
9917 ssh_pkt_getstring(pktin, &data, &len);
9918 s->gss_rcvtok.value = data;
9919 s->gss_rcvtok.length = len;
9921 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
9923 if (s->gss_stat != SSH_GSS_OK) {
9924 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9925 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9928 logevent("GSSAPI authentication loop finished OK");
9930 /* Now send the MIC */
9932 s->pktout = ssh2_pkt_init(0);
9933 micoffset = s->pktout->length;
9934 ssh_pkt_addstring_start(s->pktout);
9935 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
9936 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
9937 ssh_pkt_addstring(s->pktout, ssh->username);
9938 ssh_pkt_addstring(s->pktout, "ssh-connection");
9939 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
9941 s->gss_buf.value = (char *)s->pktout->data + micoffset;
9942 s->gss_buf.length = s->pktout->length - micoffset;
9944 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
9945 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
9946 ssh_pkt_addstring_start(s->pktout);
9947 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
9948 ssh2_pkt_send(ssh, s->pktout);
9949 s->gsslib->free_mic(s->gsslib, &mic);
9953 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9954 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9957 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
9960 * Keyboard-interactive authentication.
9963 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
9965 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
9967 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9968 ssh2_pkt_addstring(s->pktout, ssh->username);
9969 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9970 /* service requested */
9971 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
9973 ssh2_pkt_addstring(s->pktout, ""); /* lang */
9974 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
9975 ssh2_pkt_send(ssh, s->pktout);
9977 logevent("Attempting keyboard-interactive authentication");
9979 crWaitUntilV(pktin);
9980 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
9981 /* Server is not willing to do keyboard-interactive
9982 * at all (or, bizarrely but legally, accepts the
9983 * user without actually issuing any prompts).
9984 * Give up on it entirely. */
9986 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
9987 s->kbd_inter_refused = TRUE; /* don't try it again */
9992 * Loop while the server continues to send INFO_REQUESTs.
9994 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
9996 char *name, *inst, *lang;
9997 int name_len, inst_len, lang_len;
10001 * We've got a fresh USERAUTH_INFO_REQUEST.
10002 * Get the preamble and start building a prompt.
10004 ssh_pkt_getstring(pktin, &name, &name_len);
10005 ssh_pkt_getstring(pktin, &inst, &inst_len);
10006 ssh_pkt_getstring(pktin, &lang, &lang_len);
10007 s->cur_prompt = new_prompts(ssh->frontend);
10008 s->cur_prompt->to_server = TRUE;
10011 * Get any prompt(s) from the packet.
10013 s->num_prompts = ssh_pkt_getuint32(pktin);
10014 for (i = 0; i < s->num_prompts; i++) {
10018 static char noprompt[] =
10019 "<server failed to send prompt>: ";
10021 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
10022 echo = ssh2_pkt_getbool(pktin);
10025 prompt_len = lenof(noprompt)-1;
10027 add_prompt(s->cur_prompt,
10028 dupprintf("%.*s", prompt_len, prompt),
10033 /* FIXME: better prefix to distinguish from
10034 * local prompts? */
10035 s->cur_prompt->name =
10036 dupprintf("SSH server: %.*s", name_len, name);
10037 s->cur_prompt->name_reqd = TRUE;
10039 s->cur_prompt->name =
10040 dupstr("SSH server authentication");
10041 s->cur_prompt->name_reqd = FALSE;
10043 /* We add a prefix to try to make it clear that a prompt
10044 * has come from the server.
10045 * FIXME: ugly to print "Using..." in prompt _every_
10046 * time round. Can this be done more subtly? */
10047 /* Special case: for reasons best known to themselves,
10048 * some servers send k-i requests with no prompts and
10049 * nothing to display. Keep quiet in this case. */
10050 if (s->num_prompts || name_len || inst_len) {
10051 s->cur_prompt->instruction =
10052 dupprintf("Using keyboard-interactive authentication.%s%.*s",
10053 inst_len ? "\n" : "", inst_len, inst);
10054 s->cur_prompt->instr_reqd = TRUE;
10056 s->cur_prompt->instr_reqd = FALSE;
10060 * Display any instructions, and get the user's
10064 int ret; /* not live over crReturn */
10065 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10068 crWaitUntilV(!pktin);
10069 ret = get_userpass_input(s->cur_prompt, in, inlen);
10074 * Failed to get responses. Terminate.
10076 free_prompts(s->cur_prompt);
10077 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10078 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10085 * Send the response(s) to the server.
10087 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
10088 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
10089 for (i=0; i < s->num_prompts; i++) {
10090 ssh2_pkt_addstring(s->pktout,
10091 s->cur_prompt->prompts[i]->result);
10093 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10096 * Free the prompts structure from this iteration.
10097 * If there's another, a new one will be allocated
10098 * when we return to the top of this while loop.
10100 free_prompts(s->cur_prompt);
10103 * Get the next packet in case it's another
10106 crWaitUntilV(pktin);
10111 * We should have SUCCESS or FAILURE now.
10115 } else if (s->can_passwd) {
10118 * Plain old password authentication.
10120 int ret; /* not live over crReturn */
10121 int changereq_first_time; /* not live over crReturn */
10123 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
10125 s->cur_prompt = new_prompts(ssh->frontend);
10126 s->cur_prompt->to_server = TRUE;
10127 s->cur_prompt->name = dupstr("SSH password");
10128 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
10133 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10136 crWaitUntilV(!pktin);
10137 ret = get_userpass_input(s->cur_prompt, in, inlen);
10142 * Failed to get responses. Terminate.
10144 free_prompts(s->cur_prompt);
10145 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10146 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10151 * Squirrel away the password. (We may need it later if
10152 * asked to change it.)
10154 s->password = dupstr(s->cur_prompt->prompts[0]->result);
10155 free_prompts(s->cur_prompt);
10158 * Send the password packet.
10160 * We pad out the password packet to 256 bytes to make
10161 * it harder for an attacker to find the length of the
10164 * Anyone using a password longer than 256 bytes
10165 * probably doesn't have much to worry about from
10166 * people who find out how long their password is!
10168 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10169 ssh2_pkt_addstring(s->pktout, ssh->username);
10170 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10171 /* service requested */
10172 ssh2_pkt_addstring(s->pktout, "password");
10173 ssh2_pkt_addbool(s->pktout, FALSE);
10174 ssh2_pkt_addstring(s->pktout, s->password);
10175 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10176 logevent("Sent password");
10177 s->type = AUTH_TYPE_PASSWORD;
10180 * Wait for next packet, in case it's a password change
10183 crWaitUntilV(pktin);
10184 changereq_first_time = TRUE;
10186 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
10189 * We're being asked for a new password
10190 * (perhaps not for the first time).
10191 * Loop until the server accepts it.
10194 int got_new = FALSE; /* not live over crReturn */
10195 char *prompt; /* not live over crReturn */
10196 int prompt_len; /* not live over crReturn */
10200 if (changereq_first_time)
10201 msg = "Server requested password change";
10203 msg = "Server rejected new password";
10205 c_write_str(ssh, msg);
10206 c_write_str(ssh, "\r\n");
10209 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
10211 s->cur_prompt = new_prompts(ssh->frontend);
10212 s->cur_prompt->to_server = TRUE;
10213 s->cur_prompt->name = dupstr("New SSH password");
10214 s->cur_prompt->instruction =
10215 dupprintf("%.*s", prompt_len, prompt);
10216 s->cur_prompt->instr_reqd = TRUE;
10218 * There's no explicit requirement in the protocol
10219 * for the "old" passwords in the original and
10220 * password-change messages to be the same, and
10221 * apparently some Cisco kit supports password change
10222 * by the user entering a blank password originally
10223 * and the real password subsequently, so,
10224 * reluctantly, we prompt for the old password again.
10226 * (On the other hand, some servers don't even bother
10227 * to check this field.)
10229 add_prompt(s->cur_prompt,
10230 dupstr("Current password (blank for previously entered password): "),
10232 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
10234 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
10238 * Loop until the user manages to enter the same
10243 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10246 crWaitUntilV(!pktin);
10247 ret = get_userpass_input(s->cur_prompt, in, inlen);
10252 * Failed to get responses. Terminate.
10254 /* burn the evidence */
10255 free_prompts(s->cur_prompt);
10256 smemclr(s->password, strlen(s->password));
10257 sfree(s->password);
10258 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10259 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10265 * If the user specified a new original password
10266 * (IYSWIM), overwrite any previously specified
10268 * (A side effect is that the user doesn't have to
10269 * re-enter it if they louse up the new password.)
10271 if (s->cur_prompt->prompts[0]->result[0]) {
10272 smemclr(s->password, strlen(s->password));
10273 /* burn the evidence */
10274 sfree(s->password);
10276 dupstr(s->cur_prompt->prompts[0]->result);
10280 * Check the two new passwords match.
10282 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
10283 s->cur_prompt->prompts[2]->result)
10286 /* They don't. Silly user. */
10287 c_write_str(ssh, "Passwords do not match\r\n");
10292 * Send the new password (along with the old one).
10293 * (see above for padding rationale)
10295 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10296 ssh2_pkt_addstring(s->pktout, ssh->username);
10297 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10298 /* service requested */
10299 ssh2_pkt_addstring(s->pktout, "password");
10300 ssh2_pkt_addbool(s->pktout, TRUE);
10301 ssh2_pkt_addstring(s->pktout, s->password);
10302 ssh2_pkt_addstring(s->pktout,
10303 s->cur_prompt->prompts[1]->result);
10304 free_prompts(s->cur_prompt);
10305 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10306 logevent("Sent new password");
10309 * Now see what the server has to say about it.
10310 * (If it's CHANGEREQ again, it's not happy with the
10313 crWaitUntilV(pktin);
10314 changereq_first_time = FALSE;
10319 * We need to reexamine the current pktin at the top
10320 * of the loop. Either:
10321 * - we weren't asked to change password at all, in
10322 * which case it's a SUCCESS or FAILURE with the
10324 * - we sent a new password, and the server was
10325 * either OK with it (SUCCESS or FAILURE w/partial
10326 * success) or unhappy with the _old_ password
10327 * (FAILURE w/o partial success)
10328 * In any of these cases, we go back to the top of
10329 * the loop and start again.
10334 * We don't need the old password any more, in any
10335 * case. Burn the evidence.
10337 smemclr(s->password, strlen(s->password));
10338 sfree(s->password);
10341 char *str = dupprintf("No supported authentication methods available"
10342 " (server sent: %.*s)",
10345 ssh_disconnect(ssh, str,
10346 "No supported authentication methods available",
10347 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
10357 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
10359 /* Clear up various bits and pieces from authentication. */
10360 if (s->publickey_blob) {
10361 sfree(s->publickey_algorithm);
10362 sfree(s->publickey_blob);
10363 sfree(s->publickey_comment);
10365 if (s->agent_response)
10366 sfree(s->agent_response);
10368 if (s->userauth_success && !ssh->bare_connection) {
10370 * We've just received USERAUTH_SUCCESS, and we haven't sent any
10371 * packets since. Signal the transport layer to consider enacting
10372 * delayed compression.
10374 * (Relying on we_are_in is not sufficient, as
10375 * draft-miller-secsh-compression-delayed is quite clear that it
10376 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
10377 * become set for other reasons.)
10379 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
10382 ssh->channels = newtree234(ssh_channelcmp);
10385 * Set up handlers for some connection protocol messages, so we
10386 * don't have to handle them repeatedly in this coroutine.
10388 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
10389 ssh2_msg_channel_window_adjust;
10390 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
10391 ssh2_msg_global_request;
10394 * Create the main session channel.
10396 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
10397 ssh->mainchan = NULL;
10399 ssh->mainchan = snew(struct ssh_channel);
10400 ssh->mainchan->ssh = ssh;
10401 ssh2_channel_init(ssh->mainchan);
10403 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
10405 * Just start a direct-tcpip channel and use it as the main
10408 ssh_send_port_open(ssh->mainchan,
10409 conf_get_str(ssh->conf, CONF_ssh_nc_host),
10410 conf_get_int(ssh->conf, CONF_ssh_nc_port),
10412 ssh->ncmode = TRUE;
10414 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
10415 logevent("Opening session as main channel");
10416 ssh2_pkt_send(ssh, s->pktout);
10417 ssh->ncmode = FALSE;
10419 crWaitUntilV(pktin);
10420 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
10421 bombout(("Server refused to open channel"));
10423 /* FIXME: error data comes back in FAILURE packet */
10425 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
10426 bombout(("Server's channel confirmation cited wrong channel"));
10429 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
10430 ssh->mainchan->halfopen = FALSE;
10431 ssh->mainchan->type = CHAN_MAINSESSION;
10432 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
10433 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
10434 add234(ssh->channels, ssh->mainchan);
10435 update_specials_menu(ssh->frontend);
10436 logevent("Opened main channel");
10440 * Now we have a channel, make dispatch table entries for
10441 * general channel-based messages.
10443 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
10444 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
10445 ssh2_msg_channel_data;
10446 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
10447 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
10448 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
10449 ssh2_msg_channel_open_confirmation;
10450 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
10451 ssh2_msg_channel_open_failure;
10452 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
10453 ssh2_msg_channel_request;
10454 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
10455 ssh2_msg_channel_open;
10456 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
10457 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
10460 * Now the connection protocol is properly up and running, with
10461 * all those dispatch table entries, so it's safe to let
10462 * downstreams start trying to open extra channels through us.
10464 if (ssh->connshare)
10465 share_activate(ssh->connshare, ssh->v_s);
10467 if (ssh->mainchan && ssh_is_simple(ssh)) {
10469 * This message indicates to the server that we promise
10470 * not to try to run any other channel in parallel with
10471 * this one, so it's safe for it to advertise a very large
10472 * window and leave the flow control to TCP.
10474 s->pktout = ssh2_chanreq_init(ssh->mainchan,
10475 "simple@putty.projects.tartarus.org",
10477 ssh2_pkt_send(ssh, s->pktout);
10481 * Enable port forwardings.
10483 ssh_setup_portfwd(ssh, ssh->conf);
10485 if (ssh->mainchan && !ssh->ncmode) {
10487 * Send the CHANNEL_REQUESTS for the main session channel.
10488 * Each one is handled by its own little asynchronous
10492 /* Potentially enable X11 forwarding. */
10493 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
10495 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
10497 if (!ssh->x11disp) {
10498 /* FIXME: return an error message from x11_setup_display */
10499 logevent("X11 forwarding not enabled: unable to"
10500 " initialise X display");
10502 ssh->x11auth = x11_invent_fake_auth
10503 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
10504 ssh->x11auth->disp = ssh->x11disp;
10506 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
10510 /* Potentially enable agent forwarding. */
10511 if (ssh_agent_forwarding_permitted(ssh))
10512 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
10514 /* Now allocate a pty for the session. */
10515 if (!conf_get_int(ssh->conf, CONF_nopty))
10516 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
10518 /* Send environment variables. */
10519 ssh2_setup_env(ssh->mainchan, NULL, NULL);
10522 * Start a shell or a remote command. We may have to attempt
10523 * this twice if the config data has provided a second choice
10530 if (ssh->fallback_cmd) {
10531 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
10532 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
10534 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
10535 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
10539 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
10540 ssh2_response_authconn, NULL);
10541 ssh2_pkt_addstring(s->pktout, cmd);
10543 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
10544 ssh2_response_authconn, NULL);
10545 ssh2_pkt_addstring(s->pktout, cmd);
10547 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
10548 ssh2_response_authconn, NULL);
10550 ssh2_pkt_send(ssh, s->pktout);
10552 crWaitUntilV(pktin);
10554 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
10555 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
10556 bombout(("Unexpected response to shell/command request:"
10557 " packet type %d", pktin->type));
10561 * We failed to start the command. If this is the
10562 * fallback command, we really are finished; if it's
10563 * not, and if the fallback command exists, try falling
10564 * back to it before complaining.
10566 if (!ssh->fallback_cmd &&
10567 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
10568 logevent("Primary command failed; attempting fallback");
10569 ssh->fallback_cmd = TRUE;
10572 bombout(("Server refused to start a shell/command"));
10575 logevent("Started a shell/command");
10580 ssh->editing = ssh->echoing = TRUE;
10583 ssh->state = SSH_STATE_SESSION;
10584 if (ssh->size_needed)
10585 ssh_size(ssh, ssh->term_width, ssh->term_height);
10586 if (ssh->eof_needed)
10587 ssh_special(ssh, TS_EOF);
10593 ldisc_echoedit_update(ssh->ldisc); /* cause ldisc to notice changes */
10598 s->try_send = FALSE;
10602 * _All_ the connection-layer packets we expect to
10603 * receive are now handled by the dispatch table.
10604 * Anything that reaches here must be bogus.
10607 bombout(("Strange packet received: type %d", pktin->type));
10609 } else if (ssh->mainchan) {
10611 * We have spare data. Add it to the channel buffer.
10613 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
10614 s->try_send = TRUE;
10618 struct ssh_channel *c;
10620 * Try to send data on all channels if we can.
10622 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
10623 if (c->type != CHAN_SHARING)
10624 ssh2_try_send_and_unthrottle(ssh, c);
10632 * Handlers for SSH-2 messages that might arrive at any moment.
10634 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
10636 /* log reason code in disconnect message */
10638 int reason, msglen;
10640 reason = ssh_pkt_getuint32(pktin);
10641 ssh_pkt_getstring(pktin, &msg, &msglen);
10643 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
10644 buf = dupprintf("Received disconnect message (%s)",
10645 ssh2_disconnect_reasons[reason]);
10647 buf = dupprintf("Received disconnect message (unknown"
10648 " type %d)", reason);
10652 buf = dupprintf("Disconnection message text: %.*s",
10655 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
10657 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
10658 ssh2_disconnect_reasons[reason] : "unknown",
10663 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
10665 /* log the debug message */
10669 /* XXX maybe we should actually take notice of the return value */
10670 ssh2_pkt_getbool(pktin);
10671 ssh_pkt_getstring(pktin, &msg, &msglen);
10673 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
10676 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
10678 do_ssh2_transport(ssh, NULL, 0, pktin);
10682 * Called if we receive a packet that isn't allowed by the protocol.
10683 * This only applies to packets whose meaning PuTTY understands.
10684 * Entirely unknown packets are handled below.
10686 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
10688 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
10689 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
10691 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
10695 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
10697 struct Packet *pktout;
10698 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
10699 ssh2_pkt_adduint32(pktout, pktin->sequence);
10701 * UNIMPLEMENTED messages MUST appear in the same order as the
10702 * messages they respond to. Hence, never queue them.
10704 ssh2_pkt_send_noqueue(ssh, pktout);
10708 * Handle the top-level SSH-2 protocol.
10710 static void ssh2_protocol_setup(Ssh ssh)
10715 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10717 for (i = 0; i < 256; i++)
10718 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10721 * Initially, we only accept transport messages (and a few generic
10722 * ones). do_ssh2_authconn will add more when it starts.
10723 * Messages that are understood but not currently acceptable go to
10724 * ssh2_msg_unexpected.
10726 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10727 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
10728 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
10729 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
10730 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
10731 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
10732 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
10733 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
10734 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
10735 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
10736 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
10737 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
10738 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
10739 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
10740 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
10741 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
10742 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
10743 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
10744 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
10745 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10746 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10747 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10748 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10749 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10750 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10751 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10752 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10753 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10754 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10755 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10756 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10757 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10758 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10761 * These messages have a special handler from the start.
10763 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10764 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
10765 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10768 static void ssh2_bare_connection_protocol_setup(Ssh ssh)
10773 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10775 for (i = 0; i < 256; i++)
10776 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10779 * Initially, we set all ssh-connection messages to 'unexpected';
10780 * do_ssh2_authconn will fill things in properly. We also handle a
10781 * couple of messages from the transport protocol which aren't
10782 * related to key exchange (UNIMPLEMENTED, IGNORE, DEBUG,
10785 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10786 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10787 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10788 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10789 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10790 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10791 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10792 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10793 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10794 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10795 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10796 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10797 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10798 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10800 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10803 * These messages have a special handler from the start.
10805 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10806 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore;
10807 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10810 static void ssh2_timer(void *ctx, unsigned long now)
10812 Ssh ssh = (Ssh)ctx;
10814 if (ssh->state == SSH_STATE_CLOSED)
10817 if (!ssh->kex_in_progress && !ssh->bare_connection &&
10818 conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
10819 now == ssh->next_rekey) {
10820 do_ssh2_transport(ssh, "timeout", -1, NULL);
10824 static void ssh2_protocol(Ssh ssh, const void *vin, int inlen,
10825 struct Packet *pktin)
10827 const unsigned char *in = (const unsigned char *)vin;
10828 if (ssh->state == SSH_STATE_CLOSED)
10832 ssh->incoming_data_size += pktin->encrypted_len;
10833 if (!ssh->kex_in_progress &&
10834 ssh->max_data_size != 0 &&
10835 ssh->incoming_data_size > ssh->max_data_size)
10836 do_ssh2_transport(ssh, "too much data received", -1, NULL);
10840 ssh->packet_dispatch[pktin->type](ssh, pktin);
10841 else if (!ssh->protocol_initial_phase_done)
10842 do_ssh2_transport(ssh, in, inlen, pktin);
10844 do_ssh2_authconn(ssh, in, inlen, pktin);
10847 static void ssh2_bare_connection_protocol(Ssh ssh, const void *vin, int inlen,
10848 struct Packet *pktin)
10850 const unsigned char *in = (const unsigned char *)vin;
10851 if (ssh->state == SSH_STATE_CLOSED)
10855 ssh->packet_dispatch[pktin->type](ssh, pktin);
10857 do_ssh2_authconn(ssh, in, inlen, pktin);
10860 static void ssh_cache_conf_values(Ssh ssh)
10862 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
10866 * Called to set up the connection.
10868 * Returns an error message, or NULL on success.
10870 static const char *ssh_init(void *frontend_handle, void **backend_handle,
10872 const char *host, int port, char **realhost,
10873 int nodelay, int keepalive)
10878 ssh = snew(struct ssh_tag);
10879 ssh->conf = conf_copy(conf);
10880 ssh_cache_conf_values(ssh);
10881 ssh->version = 0; /* when not ready yet */
10883 ssh->cipher = NULL;
10884 ssh->v1_cipher_ctx = NULL;
10885 ssh->crcda_ctx = NULL;
10886 ssh->cscipher = NULL;
10887 ssh->cs_cipher_ctx = NULL;
10888 ssh->sccipher = NULL;
10889 ssh->sc_cipher_ctx = NULL;
10891 ssh->cs_mac_ctx = NULL;
10893 ssh->sc_mac_ctx = NULL;
10894 ssh->cscomp = NULL;
10895 ssh->cs_comp_ctx = NULL;
10896 ssh->sccomp = NULL;
10897 ssh->sc_comp_ctx = NULL;
10899 ssh->kex_ctx = NULL;
10900 ssh->hostkey = NULL;
10901 ssh->hostkey_str = NULL;
10902 ssh->exitcode = -1;
10903 ssh->close_expected = FALSE;
10904 ssh->clean_exit = FALSE;
10905 ssh->state = SSH_STATE_PREPACKET;
10906 ssh->size_needed = FALSE;
10907 ssh->eof_needed = FALSE;
10909 ssh->logctx = NULL;
10910 ssh->deferred_send_data = NULL;
10911 ssh->deferred_len = 0;
10912 ssh->deferred_size = 0;
10913 ssh->fallback_cmd = 0;
10914 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
10915 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
10916 ssh->x11disp = NULL;
10917 ssh->x11auth = NULL;
10918 ssh->x11authtree = newtree234(x11_authcmp);
10919 ssh->v1_compressing = FALSE;
10920 ssh->v2_outgoing_sequence = 0;
10921 ssh->ssh1_rdpkt_crstate = 0;
10922 ssh->ssh2_rdpkt_crstate = 0;
10923 ssh->ssh2_bare_rdpkt_crstate = 0;
10924 ssh->ssh_gotdata_crstate = 0;
10925 ssh->do_ssh1_connection_crstate = 0;
10926 ssh->do_ssh_init_state = NULL;
10927 ssh->do_ssh_connection_init_state = NULL;
10928 ssh->do_ssh1_login_state = NULL;
10929 ssh->do_ssh2_transport_state = NULL;
10930 ssh->do_ssh2_authconn_state = NULL;
10933 ssh->mainchan = NULL;
10934 ssh->throttled_all = 0;
10935 ssh->v1_stdout_throttling = 0;
10937 ssh->queuelen = ssh->queuesize = 0;
10938 ssh->queueing = FALSE;
10939 ssh->qhead = ssh->qtail = NULL;
10940 ssh->deferred_rekey_reason = NULL;
10941 bufchain_init(&ssh->queued_incoming_data);
10942 ssh->frozen = FALSE;
10943 ssh->username = NULL;
10944 ssh->sent_console_eof = FALSE;
10945 ssh->got_pty = FALSE;
10946 ssh->bare_connection = FALSE;
10947 ssh->X11_fwd_enabled = FALSE;
10948 ssh->connshare = NULL;
10949 ssh->attempting_connshare = FALSE;
10951 *backend_handle = ssh;
10954 if (crypto_startup() == 0)
10955 return "Microsoft high encryption pack not installed!";
10958 ssh->frontend = frontend_handle;
10959 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
10960 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
10962 ssh->channels = NULL;
10963 ssh->rportfwds = NULL;
10964 ssh->portfwds = NULL;
10969 ssh->conn_throttle_count = 0;
10970 ssh->overall_bufsize = 0;
10971 ssh->fallback_cmd = 0;
10973 ssh->protocol = NULL;
10975 ssh->protocol_initial_phase_done = FALSE;
10977 ssh->pinger = NULL;
10979 ssh->incoming_data_size = ssh->outgoing_data_size =
10980 ssh->deferred_data_size = 0L;
10981 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10982 CONF_ssh_rekey_data));
10983 ssh->kex_in_progress = FALSE;
10986 ssh->gsslibs = NULL;
10989 random_ref(); /* do this now - may be needed by sharing setup code */
10991 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
11000 static void ssh_free(void *handle)
11002 Ssh ssh = (Ssh) handle;
11003 struct ssh_channel *c;
11004 struct ssh_rportfwd *pf;
11005 struct X11FakeAuth *auth;
11007 if (ssh->v1_cipher_ctx)
11008 ssh->cipher->free_context(ssh->v1_cipher_ctx);
11009 if (ssh->cs_cipher_ctx)
11010 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
11011 if (ssh->sc_cipher_ctx)
11012 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
11013 if (ssh->cs_mac_ctx)
11014 ssh->csmac->free_context(ssh->cs_mac_ctx);
11015 if (ssh->sc_mac_ctx)
11016 ssh->scmac->free_context(ssh->sc_mac_ctx);
11017 if (ssh->cs_comp_ctx) {
11019 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
11021 zlib_compress_cleanup(ssh->cs_comp_ctx);
11023 if (ssh->sc_comp_ctx) {
11025 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
11027 zlib_decompress_cleanup(ssh->sc_comp_ctx);
11030 dh_cleanup(ssh->kex_ctx);
11031 sfree(ssh->savedhost);
11033 while (ssh->queuelen-- > 0)
11034 ssh_free_packet(ssh->queue[ssh->queuelen]);
11037 while (ssh->qhead) {
11038 struct queued_handler *qh = ssh->qhead;
11039 ssh->qhead = qh->next;
11042 ssh->qhead = ssh->qtail = NULL;
11044 if (ssh->channels) {
11045 while ((c = delpos234(ssh->channels, 0)) != NULL) {
11048 if (c->u.x11.xconn != NULL)
11049 x11_close(c->u.x11.xconn);
11051 case CHAN_SOCKDATA:
11052 case CHAN_SOCKDATA_DORMANT:
11053 if (c->u.pfd.pf != NULL)
11054 pfd_close(c->u.pfd.pf);
11057 if (ssh->version == 2) {
11058 struct outstanding_channel_request *ocr, *nocr;
11059 ocr = c->v.v2.chanreq_head;
11061 ocr->handler(c, NULL, ocr->ctx);
11066 bufchain_clear(&c->v.v2.outbuffer);
11070 freetree234(ssh->channels);
11071 ssh->channels = NULL;
11074 if (ssh->connshare)
11075 sharestate_free(ssh->connshare);
11077 if (ssh->rportfwds) {
11078 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
11080 freetree234(ssh->rportfwds);
11081 ssh->rportfwds = NULL;
11083 sfree(ssh->deferred_send_data);
11085 x11_free_display(ssh->x11disp);
11086 while ((auth = delpos234(ssh->x11authtree, 0)) != NULL)
11087 x11_free_fake_auth(auth);
11088 freetree234(ssh->x11authtree);
11089 sfree(ssh->do_ssh_init_state);
11090 sfree(ssh->do_ssh1_login_state);
11091 sfree(ssh->do_ssh2_transport_state);
11092 sfree(ssh->do_ssh2_authconn_state);
11095 sfree(ssh->fullhostname);
11096 sfree(ssh->hostkey_str);
11097 if (ssh->crcda_ctx) {
11098 crcda_free_context(ssh->crcda_ctx);
11099 ssh->crcda_ctx = NULL;
11102 ssh_do_close(ssh, TRUE);
11103 expire_timer_context(ssh);
11105 pinger_free(ssh->pinger);
11106 bufchain_clear(&ssh->queued_incoming_data);
11107 sfree(ssh->username);
11108 conf_free(ssh->conf);
11111 ssh_gss_cleanup(ssh->gsslibs);
11119 * Reconfigure the SSH backend.
11121 static void ssh_reconfig(void *handle, Conf *conf)
11123 Ssh ssh = (Ssh) handle;
11124 const char *rekeying = NULL;
11125 int rekey_mandatory = FALSE;
11126 unsigned long old_max_data_size;
11129 pinger_reconfig(ssh->pinger, ssh->conf, conf);
11131 ssh_setup_portfwd(ssh, conf);
11133 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
11134 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
11136 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
11137 unsigned long now = GETTICKCOUNT();
11139 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
11140 rekeying = "timeout shortened";
11142 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
11146 old_max_data_size = ssh->max_data_size;
11147 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
11148 CONF_ssh_rekey_data));
11149 if (old_max_data_size != ssh->max_data_size &&
11150 ssh->max_data_size != 0) {
11151 if (ssh->outgoing_data_size > ssh->max_data_size ||
11152 ssh->incoming_data_size > ssh->max_data_size)
11153 rekeying = "data limit lowered";
11156 if (conf_get_int(ssh->conf, CONF_compression) !=
11157 conf_get_int(conf, CONF_compression)) {
11158 rekeying = "compression setting changed";
11159 rekey_mandatory = TRUE;
11162 for (i = 0; i < CIPHER_MAX; i++)
11163 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
11164 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
11165 rekeying = "cipher settings changed";
11166 rekey_mandatory = TRUE;
11168 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
11169 conf_get_int(conf, CONF_ssh2_des_cbc)) {
11170 rekeying = "cipher settings changed";
11171 rekey_mandatory = TRUE;
11174 conf_free(ssh->conf);
11175 ssh->conf = conf_copy(conf);
11176 ssh_cache_conf_values(ssh);
11178 if (!ssh->bare_connection && rekeying) {
11179 if (!ssh->kex_in_progress) {
11180 do_ssh2_transport(ssh, rekeying, -1, NULL);
11181 } else if (rekey_mandatory) {
11182 ssh->deferred_rekey_reason = rekeying;
11188 * Called to send data down the SSH connection.
11190 static int ssh_send(void *handle, const char *buf, int len)
11192 Ssh ssh = (Ssh) handle;
11194 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
11197 ssh->protocol(ssh, (const unsigned char *)buf, len, 0);
11199 return ssh_sendbuffer(ssh);
11203 * Called to query the current amount of buffered stdin data.
11205 static int ssh_sendbuffer(void *handle)
11207 Ssh ssh = (Ssh) handle;
11208 int override_value;
11210 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
11214 * If the SSH socket itself has backed up, add the total backup
11215 * size on that to any individual buffer on the stdin channel.
11217 override_value = 0;
11218 if (ssh->throttled_all)
11219 override_value = ssh->overall_bufsize;
11221 if (ssh->version == 1) {
11222 return override_value;
11223 } else if (ssh->version == 2) {
11224 if (!ssh->mainchan)
11225 return override_value;
11227 return (override_value +
11228 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
11235 * Called to set the size of the window from SSH's POV.
11237 static void ssh_size(void *handle, int width, int height)
11239 Ssh ssh = (Ssh) handle;
11240 struct Packet *pktout;
11242 ssh->term_width = width;
11243 ssh->term_height = height;
11245 switch (ssh->state) {
11246 case SSH_STATE_BEFORE_SIZE:
11247 case SSH_STATE_PREPACKET:
11248 case SSH_STATE_CLOSED:
11249 break; /* do nothing */
11250 case SSH_STATE_INTERMED:
11251 ssh->size_needed = TRUE; /* buffer for later */
11253 case SSH_STATE_SESSION:
11254 if (!conf_get_int(ssh->conf, CONF_nopty)) {
11255 if (ssh->version == 1) {
11256 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
11257 PKT_INT, ssh->term_height,
11258 PKT_INT, ssh->term_width,
11259 PKT_INT, 0, PKT_INT, 0, PKT_END);
11260 } else if (ssh->mainchan) {
11261 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
11263 ssh2_pkt_adduint32(pktout, ssh->term_width);
11264 ssh2_pkt_adduint32(pktout, ssh->term_height);
11265 ssh2_pkt_adduint32(pktout, 0);
11266 ssh2_pkt_adduint32(pktout, 0);
11267 ssh2_pkt_send(ssh, pktout);
11275 * Return a list of the special codes that make sense in this
11278 static const struct telnet_special *ssh_get_specials(void *handle)
11280 static const struct telnet_special ssh1_ignore_special[] = {
11281 {"IGNORE message", TS_NOP}
11283 static const struct telnet_special ssh2_ignore_special[] = {
11284 {"IGNORE message", TS_NOP},
11286 static const struct telnet_special ssh2_rekey_special[] = {
11287 {"Repeat key exchange", TS_REKEY},
11289 static const struct telnet_special ssh2_session_specials[] = {
11292 /* These are the signal names defined by RFC 4254.
11293 * They include all the ISO C signals, but are a subset of the POSIX
11294 * required signals. */
11295 {"SIGINT (Interrupt)", TS_SIGINT},
11296 {"SIGTERM (Terminate)", TS_SIGTERM},
11297 {"SIGKILL (Kill)", TS_SIGKILL},
11298 {"SIGQUIT (Quit)", TS_SIGQUIT},
11299 {"SIGHUP (Hangup)", TS_SIGHUP},
11300 {"More signals", TS_SUBMENU},
11301 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
11302 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
11303 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
11304 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
11305 {NULL, TS_EXITMENU}
11307 static const struct telnet_special specials_end[] = {
11308 {NULL, TS_EXITMENU}
11310 /* XXX review this length for any changes: */
11311 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
11312 lenof(ssh2_rekey_special) +
11313 lenof(ssh2_session_specials) +
11314 lenof(specials_end)];
11315 Ssh ssh = (Ssh) handle;
11317 #define ADD_SPECIALS(name) \
11319 assert((i + lenof(name)) <= lenof(ssh_specials)); \
11320 memcpy(&ssh_specials[i], name, sizeof name); \
11321 i += lenof(name); \
11324 if (ssh->version == 1) {
11325 /* Don't bother offering IGNORE if we've decided the remote
11326 * won't cope with it, since we wouldn't bother sending it if
11328 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11329 ADD_SPECIALS(ssh1_ignore_special);
11330 } else if (ssh->version == 2) {
11331 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
11332 ADD_SPECIALS(ssh2_ignore_special);
11333 if (!(ssh->remote_bugs & BUG_SSH2_REKEY) && !ssh->bare_connection)
11334 ADD_SPECIALS(ssh2_rekey_special);
11336 ADD_SPECIALS(ssh2_session_specials);
11337 } /* else we're not ready yet */
11340 ADD_SPECIALS(specials_end);
11341 return ssh_specials;
11345 #undef ADD_SPECIALS
11349 * Send special codes. TS_EOF is useful for `plink', so you
11350 * can send an EOF and collect resulting output (e.g. `plink
11353 static void ssh_special(void *handle, Telnet_Special code)
11355 Ssh ssh = (Ssh) handle;
11356 struct Packet *pktout;
11358 if (code == TS_EOF) {
11359 if (ssh->state != SSH_STATE_SESSION) {
11361 * Buffer the EOF in case we are pre-SESSION, so we can
11362 * send it as soon as we reach SESSION.
11364 if (code == TS_EOF)
11365 ssh->eof_needed = TRUE;
11368 if (ssh->version == 1) {
11369 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
11370 } else if (ssh->mainchan) {
11371 sshfwd_write_eof(ssh->mainchan);
11372 ssh->send_ok = 0; /* now stop trying to read from stdin */
11374 logevent("Sent EOF message");
11375 } else if (code == TS_PING || code == TS_NOP) {
11376 if (ssh->state == SSH_STATE_CLOSED
11377 || ssh->state == SSH_STATE_PREPACKET) return;
11378 if (ssh->version == 1) {
11379 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11380 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
11382 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
11383 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
11384 ssh2_pkt_addstring_start(pktout);
11385 ssh2_pkt_send_noqueue(ssh, pktout);
11388 } else if (code == TS_REKEY) {
11389 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11390 ssh->version == 2) {
11391 do_ssh2_transport(ssh, "at user request", -1, NULL);
11393 } else if (code == TS_BRK) {
11394 if (ssh->state == SSH_STATE_CLOSED
11395 || ssh->state == SSH_STATE_PREPACKET) return;
11396 if (ssh->version == 1) {
11397 logevent("Unable to send BREAK signal in SSH-1");
11398 } else if (ssh->mainchan) {
11399 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
11400 ssh2_pkt_adduint32(pktout, 0); /* default break length */
11401 ssh2_pkt_send(ssh, pktout);
11404 /* Is is a POSIX signal? */
11405 const char *signame = NULL;
11406 if (code == TS_SIGABRT) signame = "ABRT";
11407 if (code == TS_SIGALRM) signame = "ALRM";
11408 if (code == TS_SIGFPE) signame = "FPE";
11409 if (code == TS_SIGHUP) signame = "HUP";
11410 if (code == TS_SIGILL) signame = "ILL";
11411 if (code == TS_SIGINT) signame = "INT";
11412 if (code == TS_SIGKILL) signame = "KILL";
11413 if (code == TS_SIGPIPE) signame = "PIPE";
11414 if (code == TS_SIGQUIT) signame = "QUIT";
11415 if (code == TS_SIGSEGV) signame = "SEGV";
11416 if (code == TS_SIGTERM) signame = "TERM";
11417 if (code == TS_SIGUSR1) signame = "USR1";
11418 if (code == TS_SIGUSR2) signame = "USR2";
11419 /* The SSH-2 protocol does in principle support arbitrary named
11420 * signals, including signame@domain, but we don't support those. */
11422 /* It's a signal. */
11423 if (ssh->version == 2 && ssh->mainchan) {
11424 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
11425 ssh2_pkt_addstring(pktout, signame);
11426 ssh2_pkt_send(ssh, pktout);
11427 logeventf(ssh, "Sent signal SIG%s", signame);
11430 /* Never heard of it. Do nothing */
11435 void *new_sock_channel(void *handle, struct PortForwarding *pf)
11437 Ssh ssh = (Ssh) handle;
11438 struct ssh_channel *c;
11439 c = snew(struct ssh_channel);
11442 ssh2_channel_init(c);
11443 c->halfopen = TRUE;
11444 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
11446 add234(ssh->channels, c);
11450 unsigned ssh_alloc_sharing_channel(Ssh ssh, void *sharing_ctx)
11452 struct ssh_channel *c;
11453 c = snew(struct ssh_channel);
11456 ssh2_channel_init(c);
11457 c->type = CHAN_SHARING;
11458 c->u.sharing.ctx = sharing_ctx;
11459 add234(ssh->channels, c);
11463 void ssh_delete_sharing_channel(Ssh ssh, unsigned localid)
11465 struct ssh_channel *c;
11467 c = find234(ssh->channels, &localid, ssh_channelfind);
11469 ssh_channel_destroy(c);
11472 void ssh_send_packet_from_downstream(Ssh ssh, unsigned id, int type,
11473 const void *data, int datalen,
11474 const char *additional_log_text)
11476 struct Packet *pkt;
11478 pkt = ssh2_pkt_init(type);
11479 pkt->downstream_id = id;
11480 pkt->additional_log_text = additional_log_text;
11481 ssh2_pkt_adddata(pkt, data, datalen);
11482 ssh2_pkt_send(ssh, pkt);
11486 * This is called when stdout/stderr (the entity to which
11487 * from_backend sends data) manages to clear some backlog.
11489 static void ssh_unthrottle(void *handle, int bufsize)
11491 Ssh ssh = (Ssh) handle;
11494 if (ssh->version == 1) {
11495 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
11496 ssh->v1_stdout_throttling = 0;
11497 ssh_throttle_conn(ssh, -1);
11500 if (ssh->mainchan) {
11501 ssh2_set_window(ssh->mainchan,
11502 bufsize < ssh->mainchan->v.v2.locmaxwin ?
11503 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
11504 if (ssh_is_simple(ssh))
11507 buflimit = ssh->mainchan->v.v2.locmaxwin;
11508 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
11509 ssh->mainchan->throttling_conn = 0;
11510 ssh_throttle_conn(ssh, -1);
11516 * Now process any SSH connection data that was stashed in our
11517 * queue while we were frozen.
11519 ssh_process_queued_incoming_data(ssh);
11522 void ssh_send_port_open(void *channel, const char *hostname, int port,
11525 struct ssh_channel *c = (struct ssh_channel *)channel;
11527 struct Packet *pktout;
11529 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
11531 if (ssh->version == 1) {
11532 send_packet(ssh, SSH1_MSG_PORT_OPEN,
11533 PKT_INT, c->localid,
11536 /* PKT_STR, <org:orgport>, */
11539 pktout = ssh2_chanopen_init(c, "direct-tcpip");
11541 char *trimmed_host = host_strduptrim(hostname);
11542 ssh2_pkt_addstring(pktout, trimmed_host);
11543 sfree(trimmed_host);
11545 ssh2_pkt_adduint32(pktout, port);
11547 * We make up values for the originator data; partly it's
11548 * too much hassle to keep track, and partly I'm not
11549 * convinced the server should be told details like that
11550 * about my local network configuration.
11551 * The "originator IP address" is syntactically a numeric
11552 * IP address, and some servers (e.g., Tectia) get upset
11553 * if it doesn't match this syntax.
11555 ssh2_pkt_addstring(pktout, "0.0.0.0");
11556 ssh2_pkt_adduint32(pktout, 0);
11557 ssh2_pkt_send(ssh, pktout);
11561 static int ssh_connected(void *handle)
11563 Ssh ssh = (Ssh) handle;
11564 return ssh->s != NULL;
11567 static int ssh_sendok(void *handle)
11569 Ssh ssh = (Ssh) handle;
11570 return ssh->send_ok;
11573 static int ssh_ldisc(void *handle, int option)
11575 Ssh ssh = (Ssh) handle;
11576 if (option == LD_ECHO)
11577 return ssh->echoing;
11578 if (option == LD_EDIT)
11579 return ssh->editing;
11583 static void ssh_provide_ldisc(void *handle, void *ldisc)
11585 Ssh ssh = (Ssh) handle;
11586 ssh->ldisc = ldisc;
11589 static void ssh_provide_logctx(void *handle, void *logctx)
11591 Ssh ssh = (Ssh) handle;
11592 ssh->logctx = logctx;
11595 static int ssh_return_exitcode(void *handle)
11597 Ssh ssh = (Ssh) handle;
11598 if (ssh->s != NULL)
11601 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
11605 * cfg_info for SSH is the protocol running in this session.
11606 * (1 or 2 for the full SSH-1 or SSH-2 protocol; -1 for the bare
11607 * SSH-2 connection protocol, i.e. a downstream; 0 for not-decided-yet.)
11609 static int ssh_cfg_info(void *handle)
11611 Ssh ssh = (Ssh) handle;
11612 if (ssh->version == 0)
11613 return 0; /* don't know yet */
11614 else if (ssh->bare_connection)
11617 return ssh->version;
11621 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
11622 * that fails. This variable is the means by which scp.c can reach
11623 * into the SSH code and find out which one it got.
11625 extern int ssh_fallback_cmd(void *handle)
11627 Ssh ssh = (Ssh) handle;
11628 return ssh->fallback_cmd;
11631 Backend ssh_backend = {
11641 ssh_return_exitcode,
11645 ssh_provide_logctx,