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
1654 for (st->i = st->len = 0; st->i < 4; st->i++) {
1655 while ((*datalen) == 0)
1657 st->pktin->data[st->i] = *(*data)++;
1660 st->len = toint(GET_32BIT(st->pktin->data));
1663 * _Completely_ silly lengths should be stomped on before they
1664 * do us any more damage.
1666 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1667 st->len % st->cipherblk != 0) {
1668 bombout(("Incoming packet length field was garbled"));
1669 ssh_free_packet(st->pktin);
1674 * So now we can work out the total packet length.
1676 st->packetlen = st->len + 4;
1679 * Allocate memory for the rest of the packet.
1681 st->pktin->maxlen = st->packetlen + st->maclen;
1682 st->pktin->data = sresize(st->pktin->data,
1683 st->pktin->maxlen + APIEXTRA,
1687 * Read the remainder of the packet.
1689 for (st->i = 4; st->i < st->packetlen + st->maclen; st->i++) {
1690 while ((*datalen) == 0)
1692 st->pktin->data[st->i] = *(*data)++;
1700 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1701 st->len + 4, st->incoming_sequence)) {
1702 bombout(("Incorrect MAC received on packet"));
1703 ssh_free_packet(st->pktin);
1707 /* Decrypt everything between the length field and the MAC. */
1709 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1710 st->pktin->data + 4,
1713 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1716 * Acquire and decrypt the first block of the packet. This will
1717 * contain the length and padding details.
1719 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1720 while ((*datalen) == 0)
1722 st->pktin->data[st->i] = *(*data)++;
1727 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1728 st->pktin->data, st->cipherblk);
1731 * Now get the length figure.
1733 st->len = toint(GET_32BIT(st->pktin->data));
1736 * _Completely_ silly lengths should be stomped on before they
1737 * do us any more damage.
1739 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1740 (st->len + 4) % st->cipherblk != 0) {
1741 bombout(("Incoming packet was garbled on decryption"));
1742 ssh_free_packet(st->pktin);
1747 * So now we can work out the total packet length.
1749 st->packetlen = st->len + 4;
1752 * Allocate memory for the rest of the packet.
1754 st->pktin->maxlen = st->packetlen + st->maclen;
1755 st->pktin->data = sresize(st->pktin->data,
1756 st->pktin->maxlen + APIEXTRA,
1760 * Read and decrypt the remainder of the packet.
1762 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1764 while ((*datalen) == 0)
1766 st->pktin->data[st->i] = *(*data)++;
1769 /* Decrypt everything _except_ the MAC. */
1771 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1772 st->pktin->data + st->cipherblk,
1773 st->packetlen - st->cipherblk);
1779 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1780 st->len + 4, st->incoming_sequence)) {
1781 bombout(("Incorrect MAC received on packet"));
1782 ssh_free_packet(st->pktin);
1786 /* Get and sanity-check the amount of random padding. */
1787 st->pad = st->pktin->data[4];
1788 if (st->pad < 4 || st->len - st->pad < 1) {
1789 bombout(("Invalid padding length on received packet"));
1790 ssh_free_packet(st->pktin);
1794 * This enables us to deduce the payload length.
1796 st->payload = st->len - st->pad - 1;
1798 st->pktin->length = st->payload + 5;
1799 st->pktin->encrypted_len = st->packetlen;
1801 st->pktin->sequence = st->incoming_sequence++;
1803 st->pktin->length = st->packetlen - st->pad;
1804 assert(st->pktin->length >= 0);
1807 * Decompress packet payload.
1810 unsigned char *newpayload;
1813 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1814 st->pktin->data + 5, st->pktin->length - 5,
1815 &newpayload, &newlen)) {
1816 if (st->pktin->maxlen < newlen + 5) {
1817 st->pktin->maxlen = newlen + 5;
1818 st->pktin->data = sresize(st->pktin->data,
1819 st->pktin->maxlen + APIEXTRA,
1822 st->pktin->length = 5 + newlen;
1823 memcpy(st->pktin->data + 5, newpayload, newlen);
1829 * pktin->body and pktin->length should identify the semantic
1830 * content of the packet, excluding the initial type byte.
1832 st->pktin->type = st->pktin->data[5];
1833 st->pktin->body = st->pktin->data + 6;
1834 st->pktin->length -= 6;
1835 assert(st->pktin->length >= 0); /* one last double-check */
1838 ssh2_log_incoming_packet(ssh, st->pktin);
1840 st->pktin->savedpos = 0;
1842 crFinish(st->pktin);
1845 static struct Packet *ssh2_bare_connection_rdpkt(Ssh ssh,
1846 const unsigned char **data,
1849 struct rdpkt2_bare_state_tag *st = &ssh->rdpkt2_bare_state;
1851 crBegin(ssh->ssh2_bare_rdpkt_crstate);
1854 * Read the packet length field.
1856 for (st->i = 0; st->i < 4; st->i++) {
1857 while ((*datalen) == 0)
1859 st->length[st->i] = *(*data)++;
1863 st->packetlen = toint(GET_32BIT_MSB_FIRST(st->length));
1864 if (st->packetlen <= 0 || st->packetlen >= OUR_V2_PACKETLIMIT) {
1865 bombout(("Invalid packet length received"));
1869 st->pktin = ssh_new_packet();
1870 st->pktin->data = snewn(st->packetlen, unsigned char);
1872 st->pktin->encrypted_len = st->packetlen;
1874 st->pktin->sequence = st->incoming_sequence++;
1877 * Read the remainder of the packet.
1879 for (st->i = 0; st->i < st->packetlen; st->i++) {
1880 while ((*datalen) == 0)
1882 st->pktin->data[st->i] = *(*data)++;
1887 * pktin->body and pktin->length should identify the semantic
1888 * content of the packet, excluding the initial type byte.
1890 st->pktin->type = st->pktin->data[0];
1891 st->pktin->body = st->pktin->data + 1;
1892 st->pktin->length = st->packetlen - 1;
1895 * Log incoming packet, possibly omitting sensitive fields.
1898 ssh2_log_incoming_packet(ssh, st->pktin);
1900 st->pktin->savedpos = 0;
1902 crFinish(st->pktin);
1905 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1907 int pad, biglen, i, pktoffs;
1911 * XXX various versions of SC (including 8.8.4) screw up the
1912 * register allocation in this function and use the same register
1913 * (D6) for len and as a temporary, with predictable results. The
1914 * following sledgehammer prevents this.
1921 ssh1_log_outgoing_packet(ssh, pkt);
1923 if (ssh->v1_compressing) {
1924 unsigned char *compblk;
1926 zlib_compress_block(ssh->cs_comp_ctx,
1927 pkt->data + 12, pkt->length - 12,
1928 &compblk, &complen);
1929 ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */
1930 memcpy(pkt->data + 12, compblk, complen);
1932 pkt->length = complen + 12;
1935 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1937 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
1938 pad = 8 - (len % 8);
1940 biglen = len + pad; /* len(padding+type+data+CRC) */
1942 for (i = pktoffs; i < 4+8; i++)
1943 pkt->data[i] = random_byte();
1944 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1945 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1946 PUT_32BIT(pkt->data + pktoffs, len);
1949 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1950 pkt->data + pktoffs + 4, biglen);
1952 if (offset_p) *offset_p = pktoffs;
1953 return biglen + 4; /* len(length+padding+type+data+CRC) */
1956 static int s_write(Ssh ssh, void *data, int len)
1959 log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len,
1960 0, NULL, NULL, 0, NULL);
1963 return sk_write(ssh->s, (char *)data, len);
1966 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1968 int len, backlog, offset;
1969 len = s_wrpkt_prepare(ssh, pkt, &offset);
1970 backlog = s_write(ssh, pkt->data + offset, len);
1971 if (backlog > SSH_MAX_BACKLOG)
1972 ssh_throttle_all(ssh, 1, backlog);
1973 ssh_free_packet(pkt);
1976 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1979 len = s_wrpkt_prepare(ssh, pkt, &offset);
1980 if (ssh->deferred_len + len > ssh->deferred_size) {
1981 ssh->deferred_size = ssh->deferred_len + len + 128;
1982 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1986 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1987 pkt->data + offset, len);
1988 ssh->deferred_len += len;
1989 ssh_free_packet(pkt);
1993 * Construct a SSH-1 packet with the specified contents.
1994 * (This all-at-once interface used to be the only one, but now SSH-1
1995 * packets can also be constructed incrementally.)
1997 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
2003 pkt = ssh1_pkt_init(pkttype);
2005 while ((argtype = va_arg(ap, int)) != PKT_END) {
2006 unsigned char *argp, argchar;
2008 unsigned long argint;
2011 /* Actual fields in the packet */
2013 argint = va_arg(ap, int);
2014 ssh_pkt_adduint32(pkt, argint);
2017 argchar = (unsigned char) va_arg(ap, int);
2018 ssh_pkt_addbyte(pkt, argchar);
2021 argp = va_arg(ap, unsigned char *);
2022 arglen = va_arg(ap, int);
2023 ssh_pkt_adddata(pkt, argp, arglen);
2026 sargp = va_arg(ap, char *);
2027 ssh_pkt_addstring(pkt, sargp);
2030 bn = va_arg(ap, Bignum);
2031 ssh1_pkt_addmp(pkt, bn);
2039 static void send_packet(Ssh ssh, int pkttype, ...)
2043 va_start(ap, pkttype);
2044 pkt = construct_packet(ssh, pkttype, ap);
2049 static void defer_packet(Ssh ssh, int pkttype, ...)
2053 va_start(ap, pkttype);
2054 pkt = construct_packet(ssh, pkttype, ap);
2056 s_wrpkt_defer(ssh, pkt);
2059 static int ssh_versioncmp(const char *a, const char *b)
2062 unsigned long av, bv;
2064 av = strtoul(a, &ae, 10);
2065 bv = strtoul(b, &be, 10);
2067 return (av < bv ? -1 : +1);
2072 av = strtoul(ae, &ae, 10);
2073 bv = strtoul(be, &be, 10);
2075 return (av < bv ? -1 : +1);
2080 * Utility routines for putting an SSH-protocol `string' and
2081 * `uint32' into a hash state.
2083 static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
2085 unsigned char lenblk[4];
2086 PUT_32BIT(lenblk, len);
2087 h->bytes(s, lenblk, 4);
2088 h->bytes(s, str, len);
2091 static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
2093 unsigned char intblk[4];
2094 PUT_32BIT(intblk, i);
2095 h->bytes(s, intblk, 4);
2099 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
2101 static void ssh_pkt_ensure(struct Packet *pkt, int length)
2103 if (pkt->maxlen < length) {
2104 unsigned char *body = pkt->body;
2105 int offset = body ? body - pkt->data : 0;
2106 pkt->maxlen = length + 256;
2107 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
2108 if (body) pkt->body = pkt->data + offset;
2111 static void ssh_pkt_adddata(struct Packet *pkt, const void *data, int len)
2114 ssh_pkt_ensure(pkt, pkt->length);
2115 memcpy(pkt->data + pkt->length - len, data, len);
2117 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
2119 ssh_pkt_adddata(pkt, &byte, 1);
2121 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
2123 ssh_pkt_adddata(pkt, &value, 1);
2125 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
2128 PUT_32BIT(x, value);
2129 ssh_pkt_adddata(pkt, x, 4);
2131 static void ssh_pkt_addstring_start(struct Packet *pkt)
2133 ssh_pkt_adduint32(pkt, 0);
2134 pkt->savedpos = pkt->length;
2136 static void ssh_pkt_addstring_data(struct Packet *pkt, const char *data,
2139 ssh_pkt_adddata(pkt, data, len);
2140 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
2142 static void ssh_pkt_addstring_str(struct Packet *pkt, const char *data)
2144 ssh_pkt_addstring_data(pkt, data, strlen(data));
2146 static void ssh_pkt_addstring(struct Packet *pkt, const char *data)
2148 ssh_pkt_addstring_start(pkt);
2149 ssh_pkt_addstring_str(pkt, data);
2151 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
2153 int len = ssh1_bignum_length(b);
2154 unsigned char *data = snewn(len, unsigned char);
2155 (void) ssh1_write_bignum(data, b);
2156 ssh_pkt_adddata(pkt, data, len);
2159 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
2162 int i, n = (bignum_bitcount(b) + 7) / 8;
2163 p = snewn(n + 1, unsigned char);
2165 for (i = 1; i <= n; i++)
2166 p[i] = bignum_byte(b, n - i);
2168 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
2170 memmove(p, p + i, n + 1 - i);
2174 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
2178 p = ssh2_mpint_fmt(b, &len);
2179 ssh_pkt_addstring_start(pkt);
2180 ssh_pkt_addstring_data(pkt, (char *)p, len);
2184 static struct Packet *ssh1_pkt_init(int pkt_type)
2186 struct Packet *pkt = ssh_new_packet();
2187 pkt->length = 4 + 8; /* space for length + max padding */
2188 ssh_pkt_addbyte(pkt, pkt_type);
2189 pkt->body = pkt->data + pkt->length;
2190 pkt->type = pkt_type;
2191 pkt->downstream_id = 0;
2192 pkt->additional_log_text = NULL;
2196 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
2197 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
2198 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
2199 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
2200 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
2201 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
2202 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
2203 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
2204 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
2206 static struct Packet *ssh2_pkt_init(int pkt_type)
2208 struct Packet *pkt = ssh_new_packet();
2209 pkt->length = 5; /* space for packet length + padding length */
2211 pkt->type = pkt_type;
2212 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
2213 pkt->body = pkt->data + pkt->length; /* after packet type */
2214 pkt->downstream_id = 0;
2215 pkt->additional_log_text = NULL;
2220 * Construct an SSH-2 final-form packet: compress it, encrypt it,
2221 * put the MAC on it. Final packet, ready to be sent, is stored in
2222 * pkt->data. Total length is returned.
2224 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
2226 int cipherblk, maclen, padding, unencrypted_prefix, i;
2229 ssh2_log_outgoing_packet(ssh, pkt);
2231 if (ssh->bare_connection) {
2233 * Trivial packet construction for the bare connection
2236 PUT_32BIT(pkt->data + 1, pkt->length - 5);
2237 pkt->body = pkt->data + 1;
2238 ssh->v2_outgoing_sequence++; /* only for diagnostics, really */
2239 return pkt->length - 1;
2243 * Compress packet payload.
2246 unsigned char *newpayload;
2249 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
2251 &newpayload, &newlen)) {
2253 ssh2_pkt_adddata(pkt, newpayload, newlen);
2259 * Add padding. At least four bytes, and must also bring total
2260 * length (minus MAC) up to a multiple of the block size.
2261 * If pkt->forcepad is set, make sure the packet is at least that size
2264 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
2265 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
2267 unencrypted_prefix = (ssh->csmac && ssh->csmac_etm) ? 4 : 0;
2268 if (pkt->length + padding < pkt->forcepad)
2269 padding = pkt->forcepad - pkt->length;
2271 (cipherblk - (pkt->length - unencrypted_prefix + padding) % cipherblk)
2273 assert(padding <= 255);
2274 maclen = ssh->csmac ? ssh->csmac->len : 0;
2275 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
2276 pkt->data[4] = padding;
2277 for (i = 0; i < padding; i++)
2278 pkt->data[pkt->length + i] = random_byte();
2279 PUT_32BIT(pkt->data, pkt->length + padding - 4);
2280 if (ssh->csmac && ssh->csmac_etm) {
2282 * OpenSSH-defined encrypt-then-MAC protocol.
2285 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
2286 pkt->data + 4, pkt->length + padding - 4);
2287 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
2288 pkt->length + padding,
2289 ssh->v2_outgoing_sequence);
2292 * SSH-2 standard protocol.
2295 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
2296 pkt->length + padding,
2297 ssh->v2_outgoing_sequence);
2299 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
2300 pkt->data, pkt->length + padding);
2303 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
2304 pkt->encrypted_len = pkt->length + padding;
2306 /* Ready-to-send packet starts at pkt->data. We return length. */
2307 pkt->body = pkt->data;
2308 return pkt->length + padding + maclen;
2312 * Routines called from the main SSH code to send packets. There
2313 * are quite a few of these, because we have two separate
2314 * mechanisms for delaying the sending of packets:
2316 * - In order to send an IGNORE message and a password message in
2317 * a single fixed-length blob, we require the ability to
2318 * concatenate the encrypted forms of those two packets _into_ a
2319 * single blob and then pass it to our <network.h> transport
2320 * layer in one go. Hence, there's a deferment mechanism which
2321 * works after packet encryption.
2323 * - In order to avoid sending any connection-layer messages
2324 * during repeat key exchange, we have to queue up any such
2325 * outgoing messages _before_ they are encrypted (and in
2326 * particular before they're allocated sequence numbers), and
2327 * then send them once we've finished.
2329 * I call these mechanisms `defer' and `queue' respectively, so as
2330 * to distinguish them reasonably easily.
2332 * The functions send_noqueue() and defer_noqueue() free the packet
2333 * structure they are passed. Every outgoing packet goes through
2334 * precisely one of these functions in its life; packets passed to
2335 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
2336 * these or get queued, and then when the queue is later emptied
2337 * the packets are all passed to defer_noqueue().
2339 * When using a CBC-mode cipher, it's necessary to ensure that an
2340 * attacker can't provide data to be encrypted using an IV that they
2341 * know. We ensure this by prefixing each packet that might contain
2342 * user data with an SSH_MSG_IGNORE. This is done using the deferral
2343 * mechanism, so in this case send_noqueue() ends up redirecting to
2344 * defer_noqueue(). If you don't like this inefficiency, don't use
2348 static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
2349 static void ssh_pkt_defersend(Ssh);
2352 * Send an SSH-2 packet immediately, without queuing or deferring.
2354 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
2358 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
2359 /* We need to send two packets, so use the deferral mechanism. */
2360 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2361 ssh_pkt_defersend(ssh);
2364 len = ssh2_pkt_construct(ssh, pkt);
2365 backlog = s_write(ssh, pkt->body, len);
2366 if (backlog > SSH_MAX_BACKLOG)
2367 ssh_throttle_all(ssh, 1, backlog);
2369 ssh->outgoing_data_size += pkt->encrypted_len;
2370 if (!ssh->kex_in_progress &&
2371 !ssh->bare_connection &&
2372 ssh->max_data_size != 0 &&
2373 ssh->outgoing_data_size > ssh->max_data_size)
2374 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2376 ssh_free_packet(pkt);
2380 * Defer an SSH-2 packet.
2382 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
2385 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
2386 ssh->deferred_len == 0 && !noignore &&
2387 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2389 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2390 * get encrypted with a known IV.
2392 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2393 ssh2_pkt_addstring_start(ipkt);
2394 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
2396 len = ssh2_pkt_construct(ssh, pkt);
2397 if (ssh->deferred_len + len > ssh->deferred_size) {
2398 ssh->deferred_size = ssh->deferred_len + len + 128;
2399 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2403 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->body, len);
2404 ssh->deferred_len += len;
2405 ssh->deferred_data_size += pkt->encrypted_len;
2406 ssh_free_packet(pkt);
2410 * Queue an SSH-2 packet.
2412 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
2414 assert(ssh->queueing);
2416 if (ssh->queuelen >= ssh->queuesize) {
2417 ssh->queuesize = ssh->queuelen + 32;
2418 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
2421 ssh->queue[ssh->queuelen++] = pkt;
2425 * Either queue or send a packet, depending on whether queueing is
2428 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
2431 ssh2_pkt_queue(ssh, pkt);
2433 ssh2_pkt_send_noqueue(ssh, pkt);
2437 * Either queue or defer a packet, depending on whether queueing is
2440 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
2443 ssh2_pkt_queue(ssh, pkt);
2445 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2449 * Send the whole deferred data block constructed by
2450 * ssh2_pkt_defer() or SSH-1's defer_packet().
2452 * The expected use of the defer mechanism is that you call
2453 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2454 * not currently queueing, this simply sets up deferred_send_data
2455 * and then sends it. If we _are_ currently queueing, the calls to
2456 * ssh2_pkt_defer() put the deferred packets on to the queue
2457 * instead, and therefore ssh_pkt_defersend() has no deferred data
2458 * to send. Hence, there's no need to make it conditional on
2461 static void ssh_pkt_defersend(Ssh ssh)
2464 backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
2465 ssh->deferred_len = ssh->deferred_size = 0;
2466 sfree(ssh->deferred_send_data);
2467 ssh->deferred_send_data = NULL;
2468 if (backlog > SSH_MAX_BACKLOG)
2469 ssh_throttle_all(ssh, 1, backlog);
2471 ssh->outgoing_data_size += ssh->deferred_data_size;
2472 if (!ssh->kex_in_progress &&
2473 !ssh->bare_connection &&
2474 ssh->max_data_size != 0 &&
2475 ssh->outgoing_data_size > ssh->max_data_size)
2476 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2477 ssh->deferred_data_size = 0;
2481 * Send a packet whose length needs to be disguised (typically
2482 * passwords or keyboard-interactive responses).
2484 static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
2490 * The simplest way to do this is to adjust the
2491 * variable-length padding field in the outgoing packet.
2493 * Currently compiled out, because some Cisco SSH servers
2494 * don't like excessively padded packets (bah, why's it
2497 pkt->forcepad = padsize;
2498 ssh2_pkt_send(ssh, pkt);
2503 * If we can't do that, however, an alternative approach is
2504 * to use the pkt_defer mechanism to bundle the packet
2505 * tightly together with an SSH_MSG_IGNORE such that their
2506 * combined length is a constant. So first we construct the
2507 * final form of this packet and defer its sending.
2509 ssh2_pkt_defer(ssh, pkt);
2512 * Now construct an SSH_MSG_IGNORE which includes a string
2513 * that's an exact multiple of the cipher block size. (If
2514 * the cipher is NULL so that the block size is
2515 * unavailable, we don't do this trick at all, because we
2516 * gain nothing by it.)
2518 if (ssh->cscipher &&
2519 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2522 stringlen = (256 - ssh->deferred_len);
2523 stringlen += ssh->cscipher->blksize - 1;
2524 stringlen -= (stringlen % ssh->cscipher->blksize);
2527 * Temporarily disable actual compression, so we
2528 * can guarantee to get this string exactly the
2529 * length we want it. The compression-disabling
2530 * routine should return an integer indicating how
2531 * many bytes we should adjust our string length
2535 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
2537 pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2538 ssh2_pkt_addstring_start(pkt);
2539 for (i = 0; i < stringlen; i++) {
2540 char c = (char) random_byte();
2541 ssh2_pkt_addstring_data(pkt, &c, 1);
2543 ssh2_pkt_defer(ssh, pkt);
2545 ssh_pkt_defersend(ssh);
2550 * Send all queued SSH-2 packets. We send them by means of
2551 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2552 * packets that needed to be lumped together.
2554 static void ssh2_pkt_queuesend(Ssh ssh)
2558 assert(!ssh->queueing);
2560 for (i = 0; i < ssh->queuelen; i++)
2561 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
2564 ssh_pkt_defersend(ssh);
2568 void bndebug(char *string, Bignum b)
2572 p = ssh2_mpint_fmt(b, &len);
2573 debug(("%s", string));
2574 for (i = 0; i < len; i++)
2575 debug((" %02x", p[i]));
2581 static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
2585 p = ssh2_mpint_fmt(b, &len);
2586 hash_string(h, s, p, len);
2591 * Packet decode functions for both SSH-1 and SSH-2.
2593 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
2595 unsigned long value;
2596 if (pkt->length - pkt->savedpos < 4)
2597 return 0; /* arrgh, no way to decline (FIXME?) */
2598 value = GET_32BIT(pkt->body + pkt->savedpos);
2602 static int ssh2_pkt_getbool(struct Packet *pkt)
2604 unsigned long value;
2605 if (pkt->length - pkt->savedpos < 1)
2606 return 0; /* arrgh, no way to decline (FIXME?) */
2607 value = pkt->body[pkt->savedpos] != 0;
2611 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
2616 if (pkt->length - pkt->savedpos < 4)
2618 len = toint(GET_32BIT(pkt->body + pkt->savedpos));
2623 if (pkt->length - pkt->savedpos < *length)
2625 *p = (char *)(pkt->body + pkt->savedpos);
2626 pkt->savedpos += *length;
2628 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
2630 if (pkt->length - pkt->savedpos < length)
2632 pkt->savedpos += length;
2633 return pkt->body + (pkt->savedpos - length);
2635 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2636 const unsigned char **keystr)
2640 j = makekey(pkt->body + pkt->savedpos,
2641 pkt->length - pkt->savedpos,
2648 assert(pkt->savedpos < pkt->length);
2652 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2657 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2658 pkt->length - pkt->savedpos, &b);
2666 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2672 ssh_pkt_getstring(pkt, &p, &length);
2677 b = bignum_from_bytes((unsigned char *)p, length);
2682 * Helper function to add an SSH-2 signature blob to a packet.
2683 * Expects to be shown the public key blob as well as the signature
2684 * blob. Normally works just like ssh2_pkt_addstring, but will
2685 * fiddle with the signature packet if necessary for
2686 * BUG_SSH2_RSA_PADDING.
2688 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2689 void *pkblob_v, int pkblob_len,
2690 void *sigblob_v, int sigblob_len)
2692 unsigned char *pkblob = (unsigned char *)pkblob_v;
2693 unsigned char *sigblob = (unsigned char *)sigblob_v;
2695 /* dmemdump(pkblob, pkblob_len); */
2696 /* dmemdump(sigblob, sigblob_len); */
2699 * See if this is in fact an ssh-rsa signature and a buggy
2700 * server; otherwise we can just do this the easy way.
2702 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) && pkblob_len > 4+7+4 &&
2703 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2704 int pos, len, siglen;
2707 * Find the byte length of the modulus.
2710 pos = 4+7; /* skip over "ssh-rsa" */
2711 len = toint(GET_32BIT(pkblob+pos)); /* get length of exponent */
2712 if (len < 0 || len > pkblob_len - pos - 4)
2714 pos += 4 + len; /* skip over exponent */
2715 if (pkblob_len - pos < 4)
2717 len = toint(GET_32BIT(pkblob+pos)); /* find length of modulus */
2718 if (len < 0 || len > pkblob_len - pos - 4)
2720 pos += 4; /* find modulus itself */
2721 while (len > 0 && pkblob[pos] == 0)
2723 /* debug(("modulus length is %d\n", len)); */
2726 * Now find the signature integer.
2728 pos = 4+7; /* skip over "ssh-rsa" */
2729 if (sigblob_len < pos+4)
2731 siglen = toint(GET_32BIT(sigblob+pos));
2732 if (siglen != sigblob_len - pos - 4)
2734 /* debug(("signature length is %d\n", siglen)); */
2736 if (len != siglen) {
2737 unsigned char newlen[4];
2738 ssh2_pkt_addstring_start(pkt);
2739 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2740 /* dmemdump(sigblob, pos); */
2741 pos += 4; /* point to start of actual sig */
2742 PUT_32BIT(newlen, len);
2743 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2744 /* dmemdump(newlen, 4); */
2746 while (len-- > siglen) {
2747 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2748 /* dmemdump(newlen, 1); */
2750 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2751 /* dmemdump(sigblob+pos, siglen); */
2755 /* Otherwise fall through and do it the easy way. We also come
2756 * here as a fallback if we discover above that the key blob
2757 * is misformatted in some way. */
2761 ssh2_pkt_addstring_start(pkt);
2762 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2766 * Examine the remote side's version string and compare it against
2767 * a list of known buggy implementations.
2769 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2771 char *imp; /* pointer to implementation part */
2773 imp += strcspn(imp, "-");
2775 imp += strcspn(imp, "-");
2778 ssh->remote_bugs = 0;
2781 * General notes on server version strings:
2782 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2783 * here -- in particular, we've heard of one that's perfectly happy
2784 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2785 * so we can't distinguish them.
2787 if (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == FORCE_ON ||
2788 (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == AUTO &&
2789 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2790 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2791 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2792 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2794 * These versions don't support SSH1_MSG_IGNORE, so we have
2795 * to use a different defence against password length
2798 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2799 logevent("We believe remote version has SSH-1 ignore bug");
2802 if (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == FORCE_ON ||
2803 (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == AUTO &&
2804 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2806 * These versions need a plain password sent; they can't
2807 * handle having a null and a random length of data after
2810 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2811 logevent("We believe remote version needs a plain SSH-1 password");
2814 if (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == FORCE_ON ||
2815 (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == AUTO &&
2816 (!strcmp(imp, "Cisco-1.25")))) {
2818 * These versions apparently have no clue whatever about
2819 * RSA authentication and will panic and die if they see
2820 * an AUTH_RSA message.
2822 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2823 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2826 if (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == FORCE_ON ||
2827 (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == AUTO &&
2828 !wc_match("* VShell", imp) &&
2829 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2830 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2831 wc_match("2.1 *", imp)))) {
2833 * These versions have the HMAC bug.
2835 ssh->remote_bugs |= BUG_SSH2_HMAC;
2836 logevent("We believe remote version has SSH-2 HMAC bug");
2839 if (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == FORCE_ON ||
2840 (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == AUTO &&
2841 !wc_match("* VShell", imp) &&
2842 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2844 * These versions have the key-derivation bug (failing to
2845 * include the literal shared secret in the hashes that
2846 * generate the keys).
2848 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2849 logevent("We believe remote version has SSH-2 key-derivation bug");
2852 if (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == FORCE_ON ||
2853 (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == AUTO &&
2854 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2855 wc_match("OpenSSH_3.[0-2]*", imp) ||
2856 wc_match("mod_sftp/0.[0-8]*", imp) ||
2857 wc_match("mod_sftp/0.9.[0-8]", imp)))) {
2859 * These versions have the SSH-2 RSA padding bug.
2861 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2862 logevent("We believe remote version has SSH-2 RSA padding bug");
2865 if (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == FORCE_ON ||
2866 (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == AUTO &&
2867 wc_match("OpenSSH_2.[0-2]*", imp))) {
2869 * These versions have the SSH-2 session-ID bug in
2870 * public-key authentication.
2872 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2873 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2876 if (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == FORCE_ON ||
2877 (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == AUTO &&
2878 (wc_match("DigiSSH_2.0", imp) ||
2879 wc_match("OpenSSH_2.[0-4]*", imp) ||
2880 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2881 wc_match("Sun_SSH_1.0", imp) ||
2882 wc_match("Sun_SSH_1.0.1", imp) ||
2883 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2884 wc_match("WeOnlyDo-*", imp)))) {
2886 * These versions have the SSH-2 rekey bug.
2888 ssh->remote_bugs |= BUG_SSH2_REKEY;
2889 logevent("We believe remote version has SSH-2 rekey bug");
2892 if (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == FORCE_ON ||
2893 (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == AUTO &&
2894 (wc_match("1.36_sshlib GlobalSCAPE", imp) ||
2895 wc_match("1.36 sshlib: GlobalScape", imp)))) {
2897 * This version ignores our makpkt and needs to be throttled.
2899 ssh->remote_bugs |= BUG_SSH2_MAXPKT;
2900 logevent("We believe remote version ignores SSH-2 maximum packet size");
2903 if (conf_get_int(ssh->conf, CONF_sshbug_ignore2) == FORCE_ON) {
2905 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2906 * none detected automatically.
2908 ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE;
2909 logevent("We believe remote version has SSH-2 ignore bug");
2912 if (conf_get_int(ssh->conf, CONF_sshbug_oldgex2) == FORCE_ON ||
2913 (conf_get_int(ssh->conf, CONF_sshbug_oldgex2) == AUTO &&
2914 (wc_match("OpenSSH_2.[235]*", imp)))) {
2916 * These versions only support the original (pre-RFC4419)
2917 * SSH-2 GEX request, and disconnect with a protocol error if
2918 * we use the newer version.
2920 ssh->remote_bugs |= BUG_SSH2_OLDGEX;
2921 logevent("We believe remote version has outdated SSH-2 GEX");
2924 if (conf_get_int(ssh->conf, CONF_sshbug_winadj) == FORCE_ON) {
2926 * Servers that don't support our winadj request for one
2927 * reason or another. Currently, none detected automatically.
2929 ssh->remote_bugs |= BUG_CHOKES_ON_WINADJ;
2930 logevent("We believe remote version has winadj bug");
2933 if (conf_get_int(ssh->conf, CONF_sshbug_chanreq) == FORCE_ON ||
2934 (conf_get_int(ssh->conf, CONF_sshbug_chanreq) == AUTO &&
2935 (wc_match("OpenSSH_[2-5].*", imp) ||
2936 wc_match("OpenSSH_6.[0-6]*", imp) ||
2937 wc_match("dropbear_0.[2-4][0-9]*", imp) ||
2938 wc_match("dropbear_0.5[01]*", imp)))) {
2940 * These versions have the SSH-2 channel request bug.
2941 * OpenSSH 6.7 and above do not:
2942 * https://bugzilla.mindrot.org/show_bug.cgi?id=1818
2943 * dropbear_0.52 and above do not:
2944 * https://secure.ucc.asn.au/hg/dropbear/rev/cd02449b709c
2946 ssh->remote_bugs |= BUG_SENDS_LATE_REQUEST_REPLY;
2947 logevent("We believe remote version has SSH-2 channel request bug");
2952 * The `software version' part of an SSH version string is required
2953 * to contain no spaces or minus signs.
2955 static void ssh_fix_verstring(char *str)
2957 /* Eat "<protoversion>-". */
2958 while (*str && *str != '-') str++;
2959 assert(*str == '-'); str++;
2961 /* Convert minus signs and spaces in the remaining string into
2964 if (*str == '-' || *str == ' ')
2971 * Send an appropriate SSH version string.
2973 static void ssh_send_verstring(Ssh ssh, const char *protoname, char *svers)
2977 if (ssh->version == 2) {
2979 * Construct a v2 version string.
2981 verstring = dupprintf("%s2.0-%s\015\012", protoname, sshver);
2984 * Construct a v1 version string.
2986 assert(!strcmp(protoname, "SSH-")); /* no v1 bare connection protocol */
2987 verstring = dupprintf("SSH-%s-%s\012",
2988 (ssh_versioncmp(svers, "1.5") <= 0 ?
2993 ssh_fix_verstring(verstring + strlen(protoname));
2995 if (ssh->version == 2) {
2998 * Record our version string.
3000 len = strcspn(verstring, "\015\012");
3001 ssh->v_c = snewn(len + 1, char);
3002 memcpy(ssh->v_c, verstring, len);
3006 logeventf(ssh, "We claim version: %.*s",
3007 strcspn(verstring, "\015\012"), verstring);
3008 s_write(ssh, verstring, strlen(verstring));
3012 static int do_ssh_init(Ssh ssh, unsigned char c)
3014 static const char protoname[] = "SSH-";
3016 struct do_ssh_init_state {
3025 crState(do_ssh_init_state);
3029 /* Search for a line beginning with the protocol name prefix in
3032 for (s->i = 0; protoname[s->i]; s->i++) {
3033 if ((char)c != protoname[s->i]) goto no;
3043 s->vstrsize = sizeof(protoname) + 16;
3044 s->vstring = snewn(s->vstrsize, char);
3045 strcpy(s->vstring, protoname);
3046 s->vslen = strlen(protoname);
3049 if (s->vslen >= s->vstrsize - 1) {
3051 s->vstring = sresize(s->vstring, s->vstrsize, char);
3053 s->vstring[s->vslen++] = c;
3056 s->version[s->i] = '\0';
3058 } else if (s->i < sizeof(s->version) - 1)
3059 s->version[s->i++] = c;
3060 } else if (c == '\012')
3062 crReturn(1); /* get another char */
3065 ssh->agentfwd_enabled = FALSE;
3066 ssh->rdpkt2_state.incoming_sequence = 0;
3068 s->vstring[s->vslen] = 0;
3069 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
3070 logeventf(ssh, "Server version: %s", s->vstring);
3071 ssh_detect_bugs(ssh, s->vstring);
3074 * Decide which SSH protocol version to support.
3077 /* Anything strictly below "2.0" means protocol 1 is supported. */
3078 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
3079 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
3080 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
3082 if (conf_get_int(ssh->conf, CONF_sshprot) == 0 && !s->proto1) {
3083 bombout(("SSH protocol version 1 required by configuration but "
3084 "not provided by server"));
3087 if (conf_get_int(ssh->conf, CONF_sshprot) == 3 && !s->proto2) {
3088 bombout(("SSH protocol version 2 required by configuration but "
3089 "not provided by server"));
3093 if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1))
3098 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
3100 /* Send the version string, if we haven't already */
3101 if (conf_get_int(ssh->conf, CONF_sshprot) != 3)
3102 ssh_send_verstring(ssh, protoname, s->version);
3104 if (ssh->version == 2) {
3107 * Record their version string.
3109 len = strcspn(s->vstring, "\015\012");
3110 ssh->v_s = snewn(len + 1, char);
3111 memcpy(ssh->v_s, s->vstring, len);
3115 * Initialise SSH-2 protocol.
3117 ssh->protocol = ssh2_protocol;
3118 ssh2_protocol_setup(ssh);
3119 ssh->s_rdpkt = ssh2_rdpkt;
3122 * Initialise SSH-1 protocol.
3124 ssh->protocol = ssh1_protocol;
3125 ssh1_protocol_setup(ssh);
3126 ssh->s_rdpkt = ssh1_rdpkt;
3128 if (ssh->version == 2)
3129 do_ssh2_transport(ssh, NULL, -1, NULL);
3131 update_specials_menu(ssh->frontend);
3132 ssh->state = SSH_STATE_BEFORE_SIZE;
3133 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3140 static int do_ssh_connection_init(Ssh ssh, unsigned char c)
3143 * Ordinary SSH begins with the banner "SSH-x.y-...". This is just
3144 * the ssh-connection part, extracted and given a trivial binary
3145 * packet protocol, so we replace 'SSH-' at the start with a new
3146 * name. In proper SSH style (though of course this part of the
3147 * proper SSH protocol _isn't_ subject to this kind of
3148 * DNS-domain-based extension), we define the new name in our
3151 static const char protoname[] =
3152 "SSHCONNECTION@putty.projects.tartarus.org-";
3154 struct do_ssh_connection_init_state {
3162 crState(do_ssh_connection_init_state);
3166 /* Search for a line beginning with the protocol name prefix in
3169 for (s->i = 0; protoname[s->i]; s->i++) {
3170 if ((char)c != protoname[s->i]) goto no;
3180 s->vstrsize = sizeof(protoname) + 16;
3181 s->vstring = snewn(s->vstrsize, char);
3182 strcpy(s->vstring, protoname);
3183 s->vslen = strlen(protoname);
3186 if (s->vslen >= s->vstrsize - 1) {
3188 s->vstring = sresize(s->vstring, s->vstrsize, char);
3190 s->vstring[s->vslen++] = c;
3193 s->version[s->i] = '\0';
3195 } else if (s->i < sizeof(s->version) - 1)
3196 s->version[s->i++] = c;
3197 } else if (c == '\012')
3199 crReturn(1); /* get another char */
3202 ssh->agentfwd_enabled = FALSE;
3203 ssh->rdpkt2_bare_state.incoming_sequence = 0;
3205 s->vstring[s->vslen] = 0;
3206 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
3207 logeventf(ssh, "Server version: %s", s->vstring);
3208 ssh_detect_bugs(ssh, s->vstring);
3211 * Decide which SSH protocol version to support. This is easy in
3212 * bare ssh-connection mode: only 2.0 is legal.
3214 if (ssh_versioncmp(s->version, "2.0") < 0) {
3215 bombout(("Server announces compatibility with SSH-1 in bare ssh-connection protocol"));
3218 if (conf_get_int(ssh->conf, CONF_sshprot) == 0) {
3219 bombout(("Bare ssh-connection protocol cannot be run in SSH-1-only mode"));
3225 logeventf(ssh, "Using bare ssh-connection protocol");
3227 /* Send the version string, if we haven't already */
3228 ssh_send_verstring(ssh, protoname, s->version);
3231 * Initialise bare connection protocol.
3233 ssh->protocol = ssh2_bare_connection_protocol;
3234 ssh2_bare_connection_protocol_setup(ssh);
3235 ssh->s_rdpkt = ssh2_bare_connection_rdpkt;
3237 update_specials_menu(ssh->frontend);
3238 ssh->state = SSH_STATE_BEFORE_SIZE;
3239 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3242 * Get authconn (really just conn) under way.
3244 do_ssh2_authconn(ssh, NULL, 0, NULL);
3251 static void ssh_process_incoming_data(Ssh ssh,
3252 const unsigned char **data, int *datalen)
3254 struct Packet *pktin;
3256 pktin = ssh->s_rdpkt(ssh, data, datalen);
3258 ssh->protocol(ssh, NULL, 0, pktin);
3259 ssh_free_packet(pktin);
3263 static void ssh_queue_incoming_data(Ssh ssh,
3264 const unsigned char **data, int *datalen)
3266 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
3271 static void ssh_process_queued_incoming_data(Ssh ssh)
3274 const unsigned char *data;
3277 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
3278 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
3282 while (!ssh->frozen && len > 0)
3283 ssh_process_incoming_data(ssh, &data, &len);
3286 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
3290 static void ssh_set_frozen(Ssh ssh, int frozen)
3293 sk_set_frozen(ssh->s, frozen);
3294 ssh->frozen = frozen;
3297 static void ssh_gotdata(Ssh ssh, const unsigned char *data, int datalen)
3299 /* Log raw data, if we're in that mode. */
3301 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
3302 0, NULL, NULL, 0, NULL);
3304 crBegin(ssh->ssh_gotdata_crstate);
3307 * To begin with, feed the characters one by one to the
3308 * protocol initialisation / selection function do_ssh_init().
3309 * When that returns 0, we're done with the initial greeting
3310 * exchange and can move on to packet discipline.
3313 int ret; /* need not be kept across crReturn */
3315 crReturnV; /* more data please */
3316 ret = ssh->do_ssh_init(ssh, *data);
3324 * We emerge from that loop when the initial negotiation is
3325 * over and we have selected an s_rdpkt function. Now pass
3326 * everything to s_rdpkt, and then pass the resulting packets
3327 * to the proper protocol handler.
3331 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
3333 ssh_queue_incoming_data(ssh, &data, &datalen);
3334 /* This uses up all data and cannot cause anything interesting
3335 * to happen; indeed, for anything to happen at all, we must
3336 * return, so break out. */
3338 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
3339 /* This uses up some or all data, and may freeze the
3341 ssh_process_queued_incoming_data(ssh);
3343 /* This uses up some or all data, and may freeze the
3345 ssh_process_incoming_data(ssh, &data, &datalen);
3347 /* FIXME this is probably EBW. */
3348 if (ssh->state == SSH_STATE_CLOSED)
3351 /* We're out of data. Go and get some more. */
3357 static int ssh_do_close(Ssh ssh, int notify_exit)
3360 struct ssh_channel *c;
3362 ssh->state = SSH_STATE_CLOSED;
3363 expire_timer_context(ssh);
3368 notify_remote_exit(ssh->frontend);
3373 * Now we must shut down any port- and X-forwarded channels going
3374 * through this connection.
3376 if (ssh->channels) {
3377 while (NULL != (c = index234(ssh->channels, 0))) {
3380 x11_close(c->u.x11.xconn);
3383 case CHAN_SOCKDATA_DORMANT:
3384 pfd_close(c->u.pfd.pf);
3387 del234(ssh->channels, c); /* moving next one to index 0 */
3388 if (ssh->version == 2)
3389 bufchain_clear(&c->v.v2.outbuffer);
3394 * Go through port-forwardings, and close any associated
3395 * listening sockets.
3397 if (ssh->portfwds) {
3398 struct ssh_portfwd *pf;
3399 while (NULL != (pf = index234(ssh->portfwds, 0))) {
3400 /* Dispose of any listening socket. */
3402 pfl_terminate(pf->local);
3403 del234(ssh->portfwds, pf); /* moving next one to index 0 */
3406 freetree234(ssh->portfwds);
3407 ssh->portfwds = NULL;
3411 * Also stop attempting to connection-share.
3413 if (ssh->connshare) {
3414 sharestate_free(ssh->connshare);
3415 ssh->connshare = NULL;
3421 static void ssh_socket_log(Plug plug, int type, SockAddr addr, int port,
3422 const char *error_msg, int error_code)
3424 Ssh ssh = (Ssh) plug;
3425 char addrbuf[256], *msg;
3427 if (ssh->attempting_connshare) {
3429 * While we're attempting connection sharing, don't loudly log
3430 * everything that happens. Real TCP connections need to be
3431 * logged when we _start_ trying to connect, because it might
3432 * be ages before they respond if something goes wrong; but
3433 * connection sharing is local and quick to respond, and it's
3434 * sufficient to simply wait and see whether it worked
3438 sk_getaddr(addr, addrbuf, lenof(addrbuf));
3441 if (sk_addr_needs_port(addr)) {
3442 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
3444 msg = dupprintf("Connecting to %s", addrbuf);
3447 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
3455 void ssh_connshare_log(Ssh ssh, int event, const char *logtext,
3456 const char *ds_err, const char *us_err)
3458 if (event == SHARE_NONE) {
3459 /* In this case, 'logtext' is an error message indicating a
3460 * reason why connection sharing couldn't be set up _at all_.
3461 * Failing that, ds_err and us_err indicate why we couldn't be
3462 * a downstream and an upstream respectively. */
3464 logeventf(ssh, "Could not set up connection sharing: %s", logtext);
3467 logeventf(ssh, "Could not set up connection sharing"
3468 " as downstream: %s", ds_err);
3470 logeventf(ssh, "Could not set up connection sharing"
3471 " as upstream: %s", us_err);
3473 } else if (event == SHARE_DOWNSTREAM) {
3474 /* In this case, 'logtext' is a local endpoint address */
3475 logeventf(ssh, "Using existing shared connection at %s", logtext);
3476 /* Also we should mention this in the console window to avoid
3477 * confusing users as to why this window doesn't behave the
3479 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3480 c_write_str(ssh,"Reusing a shared connection to this server.\r\n");
3482 } else if (event == SHARE_UPSTREAM) {
3483 /* In this case, 'logtext' is a local endpoint address too */
3484 logeventf(ssh, "Sharing this connection at %s", logtext);
3488 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
3491 Ssh ssh = (Ssh) plug;
3492 int need_notify = ssh_do_close(ssh, FALSE);
3495 if (!ssh->close_expected)
3496 error_msg = "Server unexpectedly closed network connection";
3498 error_msg = "Server closed network connection";
3501 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
3505 notify_remote_exit(ssh->frontend);
3508 logevent(error_msg);
3509 if (!ssh->close_expected || !ssh->clean_exit)
3510 connection_fatal(ssh->frontend, "%s", error_msg);
3514 static int ssh_receive(Plug plug, int urgent, char *data, int len)
3516 Ssh ssh = (Ssh) plug;
3517 ssh_gotdata(ssh, (unsigned char *)data, len);
3518 if (ssh->state == SSH_STATE_CLOSED) {
3519 ssh_do_close(ssh, TRUE);
3525 static void ssh_sent(Plug plug, int bufsize)
3527 Ssh ssh = (Ssh) plug;
3529 * If the send backlog on the SSH socket itself clears, we
3530 * should unthrottle the whole world if it was throttled.
3532 if (bufsize < SSH_MAX_BACKLOG)
3533 ssh_throttle_all(ssh, 0, bufsize);
3537 * Connect to specified host and port.
3538 * Returns an error message, or NULL on success.
3539 * Also places the canonical host name into `realhost'. It must be
3540 * freed by the caller.
3542 static const char *connect_to_host(Ssh ssh, const char *host, int port,
3543 char **realhost, int nodelay, int keepalive)
3545 static const struct plug_function_table fn_table = {
3556 int addressfamily, sshprot;
3558 loghost = conf_get_str(ssh->conf, CONF_loghost);
3563 tmphost = dupstr(loghost);
3564 ssh->savedport = 22; /* default ssh port */
3567 * A colon suffix on the hostname string also lets us affect
3568 * savedport. (Unless there are multiple colons, in which case
3569 * we assume this is an unbracketed IPv6 literal.)
3571 colon = host_strrchr(tmphost, ':');
3572 if (colon && colon == host_strchr(tmphost, ':')) {
3575 ssh->savedport = atoi(colon);
3578 ssh->savedhost = host_strduptrim(tmphost);
3581 ssh->savedhost = host_strduptrim(host);
3583 port = 22; /* default ssh port */
3584 ssh->savedport = port;
3587 ssh->fn = &fn_table; /* make 'ssh' usable as a Plug */
3590 * Try connection-sharing, in case that means we don't open a
3591 * socket after all. ssh_connection_sharing_init will connect to a
3592 * previously established upstream if it can, and failing that,
3593 * establish a listening socket for _us_ to be the upstream. In
3594 * the latter case it will return NULL just as if it had done
3595 * nothing, because here we only need to care if we're a
3596 * downstream and need to do our connection setup differently.
3598 ssh->connshare = NULL;
3599 ssh->attempting_connshare = TRUE; /* affects socket logging behaviour */
3600 ssh->s = ssh_connection_sharing_init(ssh->savedhost, ssh->savedport,
3601 ssh->conf, ssh, &ssh->connshare);
3602 ssh->attempting_connshare = FALSE;
3603 if (ssh->s != NULL) {
3605 * We are a downstream.
3607 ssh->bare_connection = TRUE;
3608 ssh->do_ssh_init = do_ssh_connection_init;
3609 ssh->fullhostname = NULL;
3610 *realhost = dupstr(host); /* best we can do */
3613 * We're not a downstream, so open a normal socket.
3615 ssh->do_ssh_init = do_ssh_init;
3620 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
3621 logeventf(ssh, "Looking up host \"%s\"%s", host,
3622 (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
3623 (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
3624 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily);
3625 if ((err = sk_addr_error(addr)) != NULL) {
3629 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3631 ssh->s = new_connection(addr, *realhost, port,
3632 0, 1, nodelay, keepalive,
3633 (Plug) ssh, ssh->conf);
3634 if ((err = sk_socket_error(ssh->s)) != NULL) {
3636 notify_remote_exit(ssh->frontend);
3642 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3643 * send the version string too.
3645 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3648 if (sshprot == 3 && !ssh->bare_connection) {
3650 ssh_send_verstring(ssh, "SSH-", NULL);
3654 * loghost, if configured, overrides realhost.
3658 *realhost = dupstr(loghost);
3665 * Throttle or unthrottle the SSH connection.
3667 static void ssh_throttle_conn(Ssh ssh, int adjust)
3669 int old_count = ssh->conn_throttle_count;
3670 ssh->conn_throttle_count += adjust;
3671 assert(ssh->conn_throttle_count >= 0);
3672 if (ssh->conn_throttle_count && !old_count) {
3673 ssh_set_frozen(ssh, 1);
3674 } else if (!ssh->conn_throttle_count && old_count) {
3675 ssh_set_frozen(ssh, 0);
3680 * Throttle or unthrottle _all_ local data streams (for when sends
3681 * on the SSH connection itself back up).
3683 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3686 struct ssh_channel *c;
3688 if (enable == ssh->throttled_all)
3690 ssh->throttled_all = enable;
3691 ssh->overall_bufsize = bufsize;
3694 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3696 case CHAN_MAINSESSION:
3698 * This is treated separately, outside the switch.
3702 x11_override_throttle(c->u.x11.xconn, enable);
3705 /* Agent channels require no buffer management. */
3708 pfd_override_throttle(c->u.pfd.pf, enable);
3714 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3716 Ssh ssh = (Ssh) sshv;
3718 ssh->agent_response = reply;
3719 ssh->agent_response_len = replylen;
3721 if (ssh->version == 1)
3722 do_ssh1_login(ssh, NULL, -1, NULL);
3724 do_ssh2_authconn(ssh, NULL, -1, NULL);
3727 static void ssh_dialog_callback(void *sshv, int ret)
3729 Ssh ssh = (Ssh) sshv;
3731 ssh->user_response = ret;
3733 if (ssh->version == 1)
3734 do_ssh1_login(ssh, NULL, -1, NULL);
3736 do_ssh2_transport(ssh, NULL, -1, NULL);
3739 * This may have unfrozen the SSH connection, so do a
3742 ssh_process_queued_incoming_data(ssh);
3745 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3747 struct ssh_channel *c = (struct ssh_channel *)cv;
3749 const void *sentreply = reply;
3751 c->u.a.outstanding_requests--;
3753 /* Fake SSH_AGENT_FAILURE. */
3754 sentreply = "\0\0\0\1\5";
3757 if (ssh->version == 2) {
3758 ssh2_add_channel_data(c, sentreply, replylen);
3761 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3762 PKT_INT, c->remoteid,
3764 PKT_DATA, sentreply, replylen,
3770 * If we've already seen an incoming EOF but haven't sent an
3771 * outgoing one, this may be the moment to send it.
3773 if (c->u.a.outstanding_requests == 0 && (c->closes & CLOSES_RCVD_EOF))
3774 sshfwd_write_eof(c);
3778 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3779 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3780 * => log `wire_reason'.
3782 static void ssh_disconnect(Ssh ssh, const char *client_reason,
3783 const char *wire_reason,
3784 int code, int clean_exit)
3788 client_reason = wire_reason;
3790 error = dupprintf("Disconnected: %s", client_reason);
3792 error = dupstr("Disconnected");
3794 if (ssh->version == 1) {
3795 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3797 } else if (ssh->version == 2) {
3798 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3799 ssh2_pkt_adduint32(pktout, code);
3800 ssh2_pkt_addstring(pktout, wire_reason);
3801 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3802 ssh2_pkt_send_noqueue(ssh, pktout);
3805 ssh->close_expected = TRUE;
3806 ssh->clean_exit = clean_exit;
3807 ssh_closing((Plug)ssh, error, 0, 0);
3811 int verify_ssh_manual_host_key(Ssh ssh, const char *fingerprint,
3812 const struct ssh_signkey *ssh2keytype,
3815 if (!conf_get_str_nthstrkey(ssh->conf, CONF_ssh_manual_hostkeys, 0)) {
3816 return -1; /* no manual keys configured */
3821 * The fingerprint string we've been given will have things
3822 * like 'ssh-rsa 2048' at the front of it. Strip those off and
3823 * narrow down to just the colon-separated hex block at the
3824 * end of the string.
3826 const char *p = strrchr(fingerprint, ' ');
3827 fingerprint = p ? p+1 : fingerprint;
3828 /* Quick sanity checks, including making sure it's in lowercase */
3829 assert(strlen(fingerprint) == 16*3 - 1);
3830 assert(fingerprint[2] == ':');
3831 assert(fingerprint[strspn(fingerprint, "0123456789abcdef:")] == 0);
3833 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3835 return 1; /* success */
3840 * Construct the base64-encoded public key blob and see if
3843 unsigned char *binblob;
3845 int binlen, atoms, i;
3846 binblob = ssh2keytype->public_blob(ssh2keydata, &binlen);
3847 atoms = (binlen + 2) / 3;
3848 base64blob = snewn(atoms * 4 + 1, char);
3849 for (i = 0; i < atoms; i++)
3850 base64_encode_atom(binblob + 3*i, binlen - 3*i, base64blob + 4*i);
3851 base64blob[atoms * 4] = '\0';
3853 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3856 return 1; /* success */
3865 * Handle the key exchange and user authentication phases.
3867 static int do_ssh1_login(Ssh ssh, const unsigned char *in, int inlen,
3868 struct Packet *pktin)
3871 unsigned char cookie[8], *ptr;
3872 struct MD5Context md5c;
3873 struct do_ssh1_login_state {
3876 unsigned char *rsabuf;
3877 const unsigned char *keystr1, *keystr2;
3878 unsigned long supported_ciphers_mask, supported_auths_mask;
3879 int tried_publickey, tried_agent;
3880 int tis_auth_refused, ccard_auth_refused;
3881 unsigned char session_id[16];
3883 void *publickey_blob;
3884 int publickey_bloblen;
3885 char *publickey_comment;
3886 int privatekey_available, privatekey_encrypted;
3887 prompts_t *cur_prompt;
3890 unsigned char request[5], *response, *p;
3900 struct RSAKey servkey, hostkey;
3902 crState(do_ssh1_login_state);
3909 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
3910 bombout(("Public key packet not received"));
3914 logevent("Received public keys");
3916 ptr = ssh_pkt_getdata(pktin, 8);
3918 bombout(("SSH-1 public key packet stopped before random cookie"));
3921 memcpy(cookie, ptr, 8);
3923 if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) ||
3924 !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) {
3925 bombout(("Failed to read SSH-1 public keys from public key packet"));
3930 * Log the host key fingerprint.
3934 logevent("Host key fingerprint is:");
3935 strcpy(logmsg, " ");
3936 s->hostkey.comment = NULL;
3937 rsa_fingerprint(logmsg + strlen(logmsg),
3938 sizeof(logmsg) - strlen(logmsg), &s->hostkey);
3942 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3943 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3944 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
3945 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
3946 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
3948 ssh->v1_local_protoflags =
3949 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3950 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
3953 MD5Update(&md5c, s->keystr2, s->hostkey.bytes);
3954 MD5Update(&md5c, s->keystr1, s->servkey.bytes);
3955 MD5Update(&md5c, cookie, 8);
3956 MD5Final(s->session_id, &md5c);
3958 for (i = 0; i < 32; i++)
3959 ssh->session_key[i] = random_byte();
3962 * Verify that the `bits' and `bytes' parameters match.
3964 if (s->hostkey.bits > s->hostkey.bytes * 8 ||
3965 s->servkey.bits > s->servkey.bytes * 8) {
3966 bombout(("SSH-1 public keys were badly formatted"));
3970 s->len = (s->hostkey.bytes > s->servkey.bytes ?
3971 s->hostkey.bytes : s->servkey.bytes);
3973 s->rsabuf = snewn(s->len, unsigned char);
3976 * Verify the host key.
3980 * First format the key into a string.
3982 int len = rsastr_len(&s->hostkey);
3983 char fingerprint[100];
3984 char *keystr = snewn(len, char);
3985 rsastr_fmt(keystr, &s->hostkey);
3986 rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey);
3988 /* First check against manually configured host keys. */
3989 s->dlgret = verify_ssh_manual_host_key(ssh, fingerprint, NULL, NULL);
3990 if (s->dlgret == 0) { /* did not match */
3991 bombout(("Host key did not appear in manually configured list"));
3994 } else if (s->dlgret < 0) { /* none configured; use standard handling */
3995 ssh_set_frozen(ssh, 1);
3996 s->dlgret = verify_ssh_host_key(ssh->frontend,
3997 ssh->savedhost, ssh->savedport,
3998 "rsa", keystr, fingerprint,
3999 ssh_dialog_callback, ssh);
4001 if (s->dlgret < 0) {
4005 bombout(("Unexpected data from server while waiting"
4006 " for user host key response"));
4009 } while (pktin || inlen > 0);
4010 s->dlgret = ssh->user_response;
4012 ssh_set_frozen(ssh, 0);
4014 if (s->dlgret == 0) {
4015 ssh_disconnect(ssh, "User aborted at host key verification",
4024 for (i = 0; i < 32; i++) {
4025 s->rsabuf[i] = ssh->session_key[i];
4027 s->rsabuf[i] ^= s->session_id[i];
4030 if (s->hostkey.bytes > s->servkey.bytes) {
4031 ret = rsaencrypt(s->rsabuf, 32, &s->servkey);
4033 ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey);
4035 ret = rsaencrypt(s->rsabuf, 32, &s->hostkey);
4037 ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey);
4040 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
4044 logevent("Encrypted session key");
4047 int cipher_chosen = 0, warn = 0;
4048 const char *cipher_string = NULL;
4050 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
4051 int next_cipher = conf_get_int_int(ssh->conf,
4052 CONF_ssh_cipherlist, i);
4053 if (next_cipher == CIPHER_WARN) {
4054 /* If/when we choose a cipher, warn about it */
4056 } else if (next_cipher == CIPHER_AES) {
4057 /* XXX Probably don't need to mention this. */
4058 logevent("AES not supported in SSH-1, skipping");
4060 switch (next_cipher) {
4061 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
4062 cipher_string = "3DES"; break;
4063 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
4064 cipher_string = "Blowfish"; break;
4065 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
4066 cipher_string = "single-DES"; break;
4068 if (s->supported_ciphers_mask & (1 << s->cipher_type))
4072 if (!cipher_chosen) {
4073 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
4074 bombout(("Server violates SSH-1 protocol by not "
4075 "supporting 3DES encryption"));
4077 /* shouldn't happen */
4078 bombout(("No supported ciphers found"));
4082 /* Warn about chosen cipher if necessary. */
4084 ssh_set_frozen(ssh, 1);
4085 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
4086 ssh_dialog_callback, ssh);
4087 if (s->dlgret < 0) {
4091 bombout(("Unexpected data from server while waiting"
4092 " for user response"));
4095 } while (pktin || inlen > 0);
4096 s->dlgret = ssh->user_response;
4098 ssh_set_frozen(ssh, 0);
4099 if (s->dlgret == 0) {
4100 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
4107 switch (s->cipher_type) {
4108 case SSH_CIPHER_3DES:
4109 logevent("Using 3DES encryption");
4111 case SSH_CIPHER_DES:
4112 logevent("Using single-DES encryption");
4114 case SSH_CIPHER_BLOWFISH:
4115 logevent("Using Blowfish encryption");
4119 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
4120 PKT_CHAR, s->cipher_type,
4121 PKT_DATA, cookie, 8,
4122 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
4123 PKT_DATA, s->rsabuf, s->len,
4124 PKT_INT, ssh->v1_local_protoflags, PKT_END);
4126 logevent("Trying to enable encryption...");
4130 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
4131 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
4133 ssh->v1_cipher_ctx = ssh->cipher->make_context();
4134 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
4135 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
4137 ssh->crcda_ctx = crcda_make_context();
4138 logevent("Installing CRC compensation attack detector");
4140 if (s->servkey.modulus) {
4141 sfree(s->servkey.modulus);
4142 s->servkey.modulus = NULL;
4144 if (s->servkey.exponent) {
4145 sfree(s->servkey.exponent);
4146 s->servkey.exponent = NULL;
4148 if (s->hostkey.modulus) {
4149 sfree(s->hostkey.modulus);
4150 s->hostkey.modulus = NULL;
4152 if (s->hostkey.exponent) {
4153 sfree(s->hostkey.exponent);
4154 s->hostkey.exponent = NULL;
4158 if (pktin->type != SSH1_SMSG_SUCCESS) {
4159 bombout(("Encryption not successfully enabled"));
4163 logevent("Successfully started encryption");
4165 fflush(stdout); /* FIXME eh? */
4167 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
4168 int ret; /* need not be kept over crReturn */
4169 s->cur_prompt = new_prompts(ssh->frontend);
4170 s->cur_prompt->to_server = TRUE;
4171 s->cur_prompt->name = dupstr("SSH login name");
4172 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
4173 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4176 crWaitUntil(!pktin);
4177 ret = get_userpass_input(s->cur_prompt, in, inlen);
4182 * Failed to get a username. Terminate.
4184 free_prompts(s->cur_prompt);
4185 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
4188 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
4189 free_prompts(s->cur_prompt);
4192 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
4194 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
4196 if (flags & FLAG_INTERACTIVE &&
4197 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
4198 c_write_str(ssh, userlog);
4199 c_write_str(ssh, "\r\n");
4207 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
4208 /* We must not attempt PK auth. Pretend we've already tried it. */
4209 s->tried_publickey = s->tried_agent = 1;
4211 s->tried_publickey = s->tried_agent = 0;
4213 s->tis_auth_refused = s->ccard_auth_refused = 0;
4215 * Load the public half of any configured keyfile for later use.
4217 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4218 if (!filename_is_null(s->keyfile)) {
4220 logeventf(ssh, "Reading key file \"%.150s\"",
4221 filename_to_str(s->keyfile));
4222 keytype = key_type(s->keyfile);
4223 if (keytype == SSH_KEYTYPE_SSH1 ||
4224 keytype == SSH_KEYTYPE_SSH1_PUBLIC) {
4226 if (rsakey_pubblob(s->keyfile,
4227 &s->publickey_blob, &s->publickey_bloblen,
4228 &s->publickey_comment, &error)) {
4229 s->privatekey_available = (keytype == SSH_KEYTYPE_SSH1);
4230 if (!s->privatekey_available)
4231 logeventf(ssh, "Key file contains public key only");
4232 s->privatekey_encrypted = rsakey_encrypted(s->keyfile,
4236 logeventf(ssh, "Unable to load key (%s)", error);
4237 msgbuf = dupprintf("Unable to load key file "
4238 "\"%.150s\" (%s)\r\n",
4239 filename_to_str(s->keyfile),
4241 c_write_str(ssh, msgbuf);
4243 s->publickey_blob = NULL;
4247 logeventf(ssh, "Unable to use this key file (%s)",
4248 key_type_to_str(keytype));
4249 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4251 filename_to_str(s->keyfile),
4252 key_type_to_str(keytype));
4253 c_write_str(ssh, msgbuf);
4255 s->publickey_blob = NULL;
4258 s->publickey_blob = NULL;
4260 while (pktin->type == SSH1_SMSG_FAILURE) {
4261 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
4263 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
4265 * Attempt RSA authentication using Pageant.
4271 logevent("Pageant is running. Requesting keys.");
4273 /* Request the keys held by the agent. */
4274 PUT_32BIT(s->request, 1);
4275 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
4276 if (!agent_query(s->request, 5, &r, &s->responselen,
4277 ssh_agent_callback, ssh)) {
4281 bombout(("Unexpected data from server while waiting"
4282 " for agent response"));
4285 } while (pktin || inlen > 0);
4286 r = ssh->agent_response;
4287 s->responselen = ssh->agent_response_len;
4289 s->response = (unsigned char *) r;
4290 if (s->response && s->responselen >= 5 &&
4291 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
4292 s->p = s->response + 5;
4293 s->nkeys = toint(GET_32BIT(s->p));
4295 logeventf(ssh, "Pageant reported negative key count %d",
4300 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
4301 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4302 unsigned char *pkblob = s->p;
4306 do { /* do while (0) to make breaking easy */
4307 n = ssh1_read_bignum
4308 (s->p, toint(s->responselen-(s->p-s->response)),
4313 n = ssh1_read_bignum
4314 (s->p, toint(s->responselen-(s->p-s->response)),
4319 if (s->responselen - (s->p-s->response) < 4)
4321 s->commentlen = toint(GET_32BIT(s->p));
4323 if (s->commentlen < 0 ||
4324 toint(s->responselen - (s->p-s->response)) <
4327 s->commentp = (char *)s->p;
4328 s->p += s->commentlen;
4332 logevent("Pageant key list packet was truncated");
4336 if (s->publickey_blob) {
4337 if (!memcmp(pkblob, s->publickey_blob,
4338 s->publickey_bloblen)) {
4339 logeventf(ssh, "Pageant key #%d matches "
4340 "configured key file", s->keyi);
4341 s->tried_publickey = 1;
4343 /* Skip non-configured key */
4346 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
4347 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4348 PKT_BIGNUM, s->key.modulus, PKT_END);
4350 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4351 logevent("Key refused");
4354 logevent("Received RSA challenge");
4355 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4356 bombout(("Server's RSA challenge was badly formatted"));
4361 char *agentreq, *q, *ret;
4364 len = 1 + 4; /* message type, bit count */
4365 len += ssh1_bignum_length(s->key.exponent);
4366 len += ssh1_bignum_length(s->key.modulus);
4367 len += ssh1_bignum_length(s->challenge);
4368 len += 16; /* session id */
4369 len += 4; /* response format */
4370 agentreq = snewn(4 + len, char);
4371 PUT_32BIT(agentreq, len);
4373 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
4374 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
4376 q += ssh1_write_bignum(q, s->key.exponent);
4377 q += ssh1_write_bignum(q, s->key.modulus);
4378 q += ssh1_write_bignum(q, s->challenge);
4379 memcpy(q, s->session_id, 16);
4381 PUT_32BIT(q, 1); /* response format */
4382 if (!agent_query(agentreq, len + 4, &vret, &retlen,
4383 ssh_agent_callback, ssh)) {
4388 bombout(("Unexpected data from server"
4389 " while waiting for agent"
4393 } while (pktin || inlen > 0);
4394 vret = ssh->agent_response;
4395 retlen = ssh->agent_response_len;
4400 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
4401 logevent("Sending Pageant's response");
4402 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4403 PKT_DATA, ret + 5, 16,
4407 if (pktin->type == SSH1_SMSG_SUCCESS) {
4409 ("Pageant's response accepted");
4410 if (flags & FLAG_VERBOSE) {
4411 c_write_str(ssh, "Authenticated using"
4413 c_write(ssh, s->commentp,
4415 c_write_str(ssh, "\" from agent\r\n");
4420 ("Pageant's response not accepted");
4423 ("Pageant failed to answer challenge");
4427 logevent("No reply received from Pageant");
4430 freebn(s->key.exponent);
4431 freebn(s->key.modulus);
4432 freebn(s->challenge);
4437 if (s->publickey_blob && !s->tried_publickey)
4438 logevent("Configured key file not in Pageant");
4440 logevent("Failed to get reply from Pageant");
4445 if (s->publickey_blob && s->privatekey_available &&
4446 !s->tried_publickey) {
4448 * Try public key authentication with the specified
4451 int got_passphrase; /* need not be kept over crReturn */
4452 if (flags & FLAG_VERBOSE)
4453 c_write_str(ssh, "Trying public key authentication.\r\n");
4454 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4455 logeventf(ssh, "Trying public key \"%s\"",
4456 filename_to_str(s->keyfile));
4457 s->tried_publickey = 1;
4458 got_passphrase = FALSE;
4459 while (!got_passphrase) {
4461 * Get a passphrase, if necessary.
4463 char *passphrase = NULL; /* only written after crReturn */
4465 if (!s->privatekey_encrypted) {
4466 if (flags & FLAG_VERBOSE)
4467 c_write_str(ssh, "No passphrase required.\r\n");
4470 int ret; /* need not be kept over crReturn */
4471 s->cur_prompt = new_prompts(ssh->frontend);
4472 s->cur_prompt->to_server = FALSE;
4473 s->cur_prompt->name = dupstr("SSH key passphrase");
4474 add_prompt(s->cur_prompt,
4475 dupprintf("Passphrase for key \"%.100s\": ",
4476 s->publickey_comment), FALSE);
4477 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4480 crWaitUntil(!pktin);
4481 ret = get_userpass_input(s->cur_prompt, in, inlen);
4485 /* Failed to get a passphrase. Terminate. */
4486 free_prompts(s->cur_prompt);
4487 ssh_disconnect(ssh, NULL, "Unable to authenticate",
4491 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
4492 free_prompts(s->cur_prompt);
4495 * Try decrypting key with passphrase.
4497 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4498 ret = loadrsakey(s->keyfile, &s->key, passphrase,
4501 smemclr(passphrase, strlen(passphrase));
4505 /* Correct passphrase. */
4506 got_passphrase = TRUE;
4507 } else if (ret == 0) {
4508 c_write_str(ssh, "Couldn't load private key from ");
4509 c_write_str(ssh, filename_to_str(s->keyfile));
4510 c_write_str(ssh, " (");
4511 c_write_str(ssh, error);
4512 c_write_str(ssh, ").\r\n");
4513 got_passphrase = FALSE;
4514 break; /* go and try something else */
4515 } else if (ret == -1) {
4516 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
4517 got_passphrase = FALSE;
4520 assert(0 && "unexpected return from loadrsakey()");
4521 got_passphrase = FALSE; /* placate optimisers */
4525 if (got_passphrase) {
4528 * Send a public key attempt.
4530 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4531 PKT_BIGNUM, s->key.modulus, PKT_END);
4534 if (pktin->type == SSH1_SMSG_FAILURE) {
4535 c_write_str(ssh, "Server refused our public key.\r\n");
4536 continue; /* go and try something else */
4538 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4539 bombout(("Bizarre response to offer of public key"));
4545 unsigned char buffer[32];
4546 Bignum challenge, response;
4548 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4549 bombout(("Server's RSA challenge was badly formatted"));
4552 response = rsadecrypt(challenge, &s->key);
4553 freebn(s->key.private_exponent);/* burn the evidence */
4555 for (i = 0; i < 32; i++) {
4556 buffer[i] = bignum_byte(response, 31 - i);
4560 MD5Update(&md5c, buffer, 32);
4561 MD5Update(&md5c, s->session_id, 16);
4562 MD5Final(buffer, &md5c);
4564 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4565 PKT_DATA, buffer, 16, PKT_END);
4572 if (pktin->type == SSH1_SMSG_FAILURE) {
4573 if (flags & FLAG_VERBOSE)
4574 c_write_str(ssh, "Failed to authenticate with"
4575 " our public key.\r\n");
4576 continue; /* go and try something else */
4577 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4578 bombout(("Bizarre response to RSA authentication response"));
4582 break; /* we're through! */
4588 * Otherwise, try various forms of password-like authentication.
4590 s->cur_prompt = new_prompts(ssh->frontend);
4592 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4593 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
4594 !s->tis_auth_refused) {
4595 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
4596 logevent("Requested TIS authentication");
4597 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
4599 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
4600 logevent("TIS authentication declined");
4601 if (flags & FLAG_INTERACTIVE)
4602 c_write_str(ssh, "TIS authentication refused.\r\n");
4603 s->tis_auth_refused = 1;
4608 char *instr_suf, *prompt;
4610 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4612 bombout(("TIS challenge packet was badly formed"));
4615 logevent("Received TIS challenge");
4616 s->cur_prompt->to_server = TRUE;
4617 s->cur_prompt->name = dupstr("SSH TIS authentication");
4618 /* Prompt heuristic comes from OpenSSH */
4619 if (memchr(challenge, '\n', challengelen)) {
4620 instr_suf = dupstr("");
4621 prompt = dupprintf("%.*s", challengelen, challenge);
4623 instr_suf = dupprintf("%.*s", challengelen, challenge);
4624 prompt = dupstr("Response: ");
4626 s->cur_prompt->instruction =
4627 dupprintf("Using TIS authentication.%s%s",
4628 (*instr_suf) ? "\n" : "",
4630 s->cur_prompt->instr_reqd = TRUE;
4631 add_prompt(s->cur_prompt, prompt, FALSE);
4635 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4636 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
4637 !s->ccard_auth_refused) {
4638 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
4639 logevent("Requested CryptoCard authentication");
4640 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
4642 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
4643 logevent("CryptoCard authentication declined");
4644 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4645 s->ccard_auth_refused = 1;
4650 char *instr_suf, *prompt;
4652 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4654 bombout(("CryptoCard challenge packet was badly formed"));
4657 logevent("Received CryptoCard challenge");
4658 s->cur_prompt->to_server = TRUE;
4659 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4660 s->cur_prompt->name_reqd = FALSE;
4661 /* Prompt heuristic comes from OpenSSH */
4662 if (memchr(challenge, '\n', challengelen)) {
4663 instr_suf = dupstr("");
4664 prompt = dupprintf("%.*s", challengelen, challenge);
4666 instr_suf = dupprintf("%.*s", challengelen, challenge);
4667 prompt = dupstr("Response: ");
4669 s->cur_prompt->instruction =
4670 dupprintf("Using CryptoCard authentication.%s%s",
4671 (*instr_suf) ? "\n" : "",
4673 s->cur_prompt->instr_reqd = TRUE;
4674 add_prompt(s->cur_prompt, prompt, FALSE);
4678 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4679 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4680 bombout(("No supported authentication methods available"));
4683 s->cur_prompt->to_server = TRUE;
4684 s->cur_prompt->name = dupstr("SSH password");
4685 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4686 ssh->username, ssh->savedhost),
4691 * Show password prompt, having first obtained it via a TIS
4692 * or CryptoCard exchange if we're doing TIS or CryptoCard
4696 int ret; /* need not be kept over crReturn */
4697 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4700 crWaitUntil(!pktin);
4701 ret = get_userpass_input(s->cur_prompt, in, inlen);
4706 * Failed to get a password (for example
4707 * because one was supplied on the command line
4708 * which has already failed to work). Terminate.
4710 free_prompts(s->cur_prompt);
4711 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4716 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4718 * Defence against traffic analysis: we send a
4719 * whole bunch of packets containing strings of
4720 * different lengths. One of these strings is the
4721 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4722 * The others are all random data in
4723 * SSH1_MSG_IGNORE packets. This way a passive
4724 * listener can't tell which is the password, and
4725 * hence can't deduce the password length.
4727 * Anybody with a password length greater than 16
4728 * bytes is going to have enough entropy in their
4729 * password that a listener won't find it _that_
4730 * much help to know how long it is. So what we'll
4733 * - if password length < 16, we send 15 packets
4734 * containing string lengths 1 through 15
4736 * - otherwise, we let N be the nearest multiple
4737 * of 8 below the password length, and send 8
4738 * packets containing string lengths N through
4739 * N+7. This won't obscure the order of
4740 * magnitude of the password length, but it will
4741 * introduce a bit of extra uncertainty.
4743 * A few servers can't deal with SSH1_MSG_IGNORE, at
4744 * least in this context. For these servers, we need
4745 * an alternative defence. We make use of the fact
4746 * that the password is interpreted as a C string:
4747 * so we can append a NUL, then some random data.
4749 * A few servers can deal with neither SSH1_MSG_IGNORE
4750 * here _nor_ a padded password string.
4751 * For these servers we are left with no defences
4752 * against password length sniffing.
4754 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4755 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4757 * The server can deal with SSH1_MSG_IGNORE, so
4758 * we can use the primary defence.
4760 int bottom, top, pwlen, i;
4763 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4765 bottom = 0; /* zero length passwords are OK! :-) */
4768 bottom = pwlen & ~7;
4772 assert(pwlen >= bottom && pwlen <= top);
4774 randomstr = snewn(top + 1, char);
4776 for (i = bottom; i <= top; i++) {
4778 defer_packet(ssh, s->pwpkt_type,
4779 PKT_STR,s->cur_prompt->prompts[0]->result,
4782 for (j = 0; j < i; j++) {
4784 randomstr[j] = random_byte();
4785 } while (randomstr[j] == '\0');
4787 randomstr[i] = '\0';
4788 defer_packet(ssh, SSH1_MSG_IGNORE,
4789 PKT_STR, randomstr, PKT_END);
4792 logevent("Sending password with camouflage packets");
4793 ssh_pkt_defersend(ssh);
4796 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4798 * The server can't deal with SSH1_MSG_IGNORE
4799 * but can deal with padded passwords, so we
4800 * can use the secondary defence.
4806 len = strlen(s->cur_prompt->prompts[0]->result);
4807 if (len < sizeof(string)) {
4809 strcpy(string, s->cur_prompt->prompts[0]->result);
4810 len++; /* cover the zero byte */
4811 while (len < sizeof(string)) {
4812 string[len++] = (char) random_byte();
4815 ss = s->cur_prompt->prompts[0]->result;
4817 logevent("Sending length-padded password");
4818 send_packet(ssh, s->pwpkt_type,
4819 PKT_INT, len, PKT_DATA, ss, len,
4823 * The server is believed unable to cope with
4824 * any of our password camouflage methods.
4827 len = strlen(s->cur_prompt->prompts[0]->result);
4828 logevent("Sending unpadded password");
4829 send_packet(ssh, s->pwpkt_type,
4831 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4835 send_packet(ssh, s->pwpkt_type,
4836 PKT_STR, s->cur_prompt->prompts[0]->result,
4839 logevent("Sent password");
4840 free_prompts(s->cur_prompt);
4842 if (pktin->type == SSH1_SMSG_FAILURE) {
4843 if (flags & FLAG_VERBOSE)
4844 c_write_str(ssh, "Access denied\r\n");
4845 logevent("Authentication refused");
4846 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4847 bombout(("Strange packet received, type %d", pktin->type));
4853 if (s->publickey_blob) {
4854 sfree(s->publickey_blob);
4855 sfree(s->publickey_comment);
4858 logevent("Authentication successful");
4863 static void ssh_channel_try_eof(struct ssh_channel *c)
4866 assert(c->pending_eof); /* precondition for calling us */
4868 return; /* can't close: not even opened yet */
4869 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4870 return; /* can't send EOF: pending outgoing data */
4872 c->pending_eof = FALSE; /* we're about to send it */
4873 if (ssh->version == 1) {
4874 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4876 c->closes |= CLOSES_SENT_EOF;
4878 struct Packet *pktout;
4879 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4880 ssh2_pkt_adduint32(pktout, c->remoteid);
4881 ssh2_pkt_send(ssh, pktout);
4882 c->closes |= CLOSES_SENT_EOF;
4883 ssh2_channel_check_close(c);
4887 Conf *sshfwd_get_conf(struct ssh_channel *c)
4893 void sshfwd_write_eof(struct ssh_channel *c)
4897 if (ssh->state == SSH_STATE_CLOSED)
4900 if (c->closes & CLOSES_SENT_EOF)
4903 c->pending_eof = TRUE;
4904 ssh_channel_try_eof(c);
4907 void sshfwd_unclean_close(struct ssh_channel *c, const char *err)
4911 if (ssh->state == SSH_STATE_CLOSED)
4916 x11_close(c->u.x11.xconn);
4917 logeventf(ssh, "Forwarded X11 connection terminated due to local "
4921 case CHAN_SOCKDATA_DORMANT:
4922 pfd_close(c->u.pfd.pf);
4923 logeventf(ssh, "Forwarded port closed due to local error: %s", err);
4926 c->type = CHAN_ZOMBIE;
4927 c->pending_eof = FALSE; /* this will confuse a zombie channel */
4929 ssh2_channel_check_close(c);
4932 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
4936 if (ssh->state == SSH_STATE_CLOSED)
4939 if (ssh->version == 1) {
4940 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
4941 PKT_INT, c->remoteid,
4942 PKT_INT, len, PKT_DATA, buf, len,
4945 * In SSH-1 we can return 0 here - implying that forwarded
4946 * connections are never individually throttled - because
4947 * the only circumstance that can cause throttling will be
4948 * the whole SSH connection backing up, in which case
4949 * _everything_ will be throttled as a whole.
4953 ssh2_add_channel_data(c, buf, len);
4954 return ssh2_try_send(c);
4958 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4963 if (ssh->state == SSH_STATE_CLOSED)
4966 if (ssh->version == 1) {
4967 buflimit = SSH1_BUFFER_LIMIT;
4969 buflimit = c->v.v2.locmaxwin;
4970 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
4972 if (c->throttling_conn && bufsize <= buflimit) {
4973 c->throttling_conn = 0;
4974 ssh_throttle_conn(ssh, -1);
4978 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
4980 struct queued_handler *qh = ssh->qhead;
4984 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
4987 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
4988 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
4991 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
4992 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
4996 ssh->qhead = qh->next;
4998 if (ssh->qhead->msg1 > 0) {
4999 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
5000 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
5002 if (ssh->qhead->msg2 > 0) {
5003 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
5004 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
5007 ssh->qhead = ssh->qtail = NULL;
5010 qh->handler(ssh, pktin, qh->ctx);
5015 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
5016 chandler_fn_t handler, void *ctx)
5018 struct queued_handler *qh;
5020 qh = snew(struct queued_handler);
5023 qh->handler = handler;
5027 if (ssh->qtail == NULL) {
5031 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
5032 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
5035 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
5036 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
5039 ssh->qtail->next = qh;
5044 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
5046 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
5048 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
5049 SSH2_MSG_REQUEST_SUCCESS)) {
5050 logeventf(ssh, "Remote port forwarding from %s enabled",
5053 logeventf(ssh, "Remote port forwarding from %s refused",
5056 rpf = del234(ssh->rportfwds, pf);
5058 pf->pfrec->remote = NULL;
5063 int ssh_alloc_sharing_rportfwd(Ssh ssh, const char *shost, int sport,
5066 struct ssh_rportfwd *pf = snew(struct ssh_rportfwd);
5069 pf->share_ctx = share_ctx;
5070 pf->shost = dupstr(shost);
5072 pf->sportdesc = NULL;
5073 if (!ssh->rportfwds) {
5074 assert(ssh->version == 2);
5075 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5077 if (add234(ssh->rportfwds, pf) != pf) {
5085 static void ssh_sharing_global_request_response(Ssh ssh, struct Packet *pktin,
5088 share_got_pkt_from_server(ctx, pktin->type,
5089 pktin->body, pktin->length);
5092 void ssh_sharing_queue_global_request(Ssh ssh, void *share_ctx)
5094 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, SSH2_MSG_REQUEST_FAILURE,
5095 ssh_sharing_global_request_response, share_ctx);
5098 static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
5100 struct ssh_portfwd *epf;
5104 if (!ssh->portfwds) {
5105 ssh->portfwds = newtree234(ssh_portcmp);
5108 * Go through the existing port forwardings and tag them
5109 * with status==DESTROY. Any that we want to keep will be
5110 * re-enabled (status==KEEP) as we go through the
5111 * configuration and find out which bits are the same as
5114 struct ssh_portfwd *epf;
5116 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5117 epf->status = DESTROY;
5120 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
5122 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
5123 char *kp, *kp2, *vp, *vp2;
5124 char address_family, type;
5125 int sport,dport,sserv,dserv;
5126 char *sports, *dports, *saddr, *host;
5130 address_family = 'A';
5132 if (*kp == 'A' || *kp == '4' || *kp == '6')
5133 address_family = *kp++;
5134 if (*kp == 'L' || *kp == 'R')
5137 if ((kp2 = host_strchr(kp, ':')) != NULL) {
5139 * There's a colon in the middle of the source port
5140 * string, which means that the part before it is
5141 * actually a source address.
5143 char *saddr_tmp = dupprintf("%.*s", (int)(kp2 - kp), kp);
5144 saddr = host_strduptrim(saddr_tmp);
5151 sport = atoi(sports);
5155 sport = net_service_lookup(sports);
5157 logeventf(ssh, "Service lookup failed for source"
5158 " port \"%s\"", sports);
5162 if (type == 'L' && !strcmp(val, "D")) {
5163 /* dynamic forwarding */
5170 /* ordinary forwarding */
5172 vp2 = vp + host_strcspn(vp, ":");
5173 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
5177 dport = atoi(dports);
5181 dport = net_service_lookup(dports);
5183 logeventf(ssh, "Service lookup failed for destination"
5184 " port \"%s\"", dports);
5189 if (sport && dport) {
5190 /* Set up a description of the source port. */
5191 struct ssh_portfwd *pfrec, *epfrec;
5193 pfrec = snew(struct ssh_portfwd);
5195 pfrec->saddr = saddr;
5196 pfrec->sserv = sserv ? dupstr(sports) : NULL;
5197 pfrec->sport = sport;
5198 pfrec->daddr = host;
5199 pfrec->dserv = dserv ? dupstr(dports) : NULL;
5200 pfrec->dport = dport;
5201 pfrec->local = NULL;
5202 pfrec->remote = NULL;
5203 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
5204 address_family == '6' ? ADDRTYPE_IPV6 :
5207 epfrec = add234(ssh->portfwds, pfrec);
5208 if (epfrec != pfrec) {
5209 if (epfrec->status == DESTROY) {
5211 * We already have a port forwarding up and running
5212 * with precisely these parameters. Hence, no need
5213 * to do anything; simply re-tag the existing one
5216 epfrec->status = KEEP;
5219 * Anything else indicates that there was a duplicate
5220 * in our input, which we'll silently ignore.
5222 free_portfwd(pfrec);
5224 pfrec->status = CREATE;
5233 * Now go through and destroy any port forwardings which were
5236 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5237 if (epf->status == DESTROY) {
5240 message = dupprintf("%s port forwarding from %s%s%d",
5241 epf->type == 'L' ? "local" :
5242 epf->type == 'R' ? "remote" : "dynamic",
5243 epf->saddr ? epf->saddr : "",
5244 epf->saddr ? ":" : "",
5247 if (epf->type != 'D') {
5248 char *msg2 = dupprintf("%s to %s:%d", message,
5249 epf->daddr, epf->dport);
5254 logeventf(ssh, "Cancelling %s", message);
5257 /* epf->remote or epf->local may be NULL if setting up a
5258 * forwarding failed. */
5260 struct ssh_rportfwd *rpf = epf->remote;
5261 struct Packet *pktout;
5264 * Cancel the port forwarding at the server
5267 if (ssh->version == 1) {
5269 * We cannot cancel listening ports on the
5270 * server side in SSH-1! There's no message
5271 * to support it. Instead, we simply remove
5272 * the rportfwd record from the local end
5273 * so that any connections the server tries
5274 * to make on it are rejected.
5277 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5278 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
5279 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
5281 ssh2_pkt_addstring(pktout, epf->saddr);
5282 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5283 /* XXX: rport_acceptall may not represent
5284 * what was used to open the original connection,
5285 * since it's reconfigurable. */
5286 ssh2_pkt_addstring(pktout, "");
5288 ssh2_pkt_addstring(pktout, "localhost");
5290 ssh2_pkt_adduint32(pktout, epf->sport);
5291 ssh2_pkt_send(ssh, pktout);
5294 del234(ssh->rportfwds, rpf);
5296 } else if (epf->local) {
5297 pfl_terminate(epf->local);
5300 delpos234(ssh->portfwds, i);
5302 i--; /* so we don't skip one in the list */
5306 * And finally, set up any new port forwardings (status==CREATE).
5308 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5309 if (epf->status == CREATE) {
5310 char *sportdesc, *dportdesc;
5311 sportdesc = dupprintf("%s%s%s%s%d%s",
5312 epf->saddr ? epf->saddr : "",
5313 epf->saddr ? ":" : "",
5314 epf->sserv ? epf->sserv : "",
5315 epf->sserv ? "(" : "",
5317 epf->sserv ? ")" : "");
5318 if (epf->type == 'D') {
5321 dportdesc = dupprintf("%s:%s%s%d%s",
5323 epf->dserv ? epf->dserv : "",
5324 epf->dserv ? "(" : "",
5326 epf->dserv ? ")" : "");
5329 if (epf->type == 'L') {
5330 char *err = pfl_listen(epf->daddr, epf->dport,
5331 epf->saddr, epf->sport,
5332 ssh, conf, &epf->local,
5333 epf->addressfamily);
5335 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
5336 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5337 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5338 sportdesc, dportdesc,
5339 err ? " failed: " : "", err ? err : "");
5342 } else if (epf->type == 'D') {
5343 char *err = pfl_listen(NULL, -1, epf->saddr, epf->sport,
5344 ssh, conf, &epf->local,
5345 epf->addressfamily);
5347 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
5348 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5349 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5351 err ? " failed: " : "", err ? err : "");
5356 struct ssh_rportfwd *pf;
5359 * Ensure the remote port forwardings tree exists.
5361 if (!ssh->rportfwds) {
5362 if (ssh->version == 1)
5363 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
5365 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5368 pf = snew(struct ssh_rportfwd);
5369 pf->share_ctx = NULL;
5370 pf->dhost = dupstr(epf->daddr);
5371 pf->dport = epf->dport;
5373 pf->shost = dupstr(epf->saddr);
5374 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5375 pf->shost = dupstr("");
5377 pf->shost = dupstr("localhost");
5379 pf->sport = epf->sport;
5380 if (add234(ssh->rportfwds, pf) != pf) {
5381 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
5382 epf->daddr, epf->dport);
5385 logeventf(ssh, "Requesting remote port %s"
5386 " forward to %s", sportdesc, dportdesc);
5388 pf->sportdesc = sportdesc;
5393 if (ssh->version == 1) {
5394 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
5395 PKT_INT, epf->sport,
5396 PKT_STR, epf->daddr,
5397 PKT_INT, epf->dport,
5399 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
5401 ssh_rportfwd_succfail, pf);
5403 struct Packet *pktout;
5404 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5405 ssh2_pkt_addstring(pktout, "tcpip-forward");
5406 ssh2_pkt_addbool(pktout, 1);/* want reply */
5407 ssh2_pkt_addstring(pktout, pf->shost);
5408 ssh2_pkt_adduint32(pktout, pf->sport);
5409 ssh2_pkt_send(ssh, pktout);
5411 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
5412 SSH2_MSG_REQUEST_FAILURE,
5413 ssh_rportfwd_succfail, pf);
5422 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
5425 int stringlen, bufsize;
5427 ssh_pkt_getstring(pktin, &string, &stringlen);
5428 if (string == NULL) {
5429 bombout(("Incoming terminal data packet was badly formed"));
5433 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
5435 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
5436 ssh->v1_stdout_throttling = 1;
5437 ssh_throttle_conn(ssh, +1);
5441 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
5443 /* Remote side is trying to open a channel to talk to our
5444 * X-Server. Give them back a local channel number. */
5445 struct ssh_channel *c;
5446 int remoteid = ssh_pkt_getuint32(pktin);
5448 logevent("Received X11 connect request");
5449 /* Refuse if X11 forwarding is disabled. */
5450 if (!ssh->X11_fwd_enabled) {
5451 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5452 PKT_INT, remoteid, PKT_END);
5453 logevent("Rejected X11 connect request");
5455 c = snew(struct ssh_channel);
5458 c->u.x11.xconn = x11_init(ssh->x11authtree, c, NULL, -1);
5459 c->remoteid = remoteid;
5460 c->halfopen = FALSE;
5461 c->localid = alloc_channel_id(ssh);
5463 c->pending_eof = FALSE;
5464 c->throttling_conn = 0;
5465 c->type = CHAN_X11; /* identify channel type */
5466 add234(ssh->channels, c);
5467 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5468 PKT_INT, c->remoteid, PKT_INT,
5469 c->localid, PKT_END);
5470 logevent("Opened X11 forward channel");
5474 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
5476 /* Remote side is trying to open a channel to talk to our
5477 * agent. Give them back a local channel number. */
5478 struct ssh_channel *c;
5479 int remoteid = ssh_pkt_getuint32(pktin);
5481 /* Refuse if agent forwarding is disabled. */
5482 if (!ssh->agentfwd_enabled) {
5483 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5484 PKT_INT, remoteid, PKT_END);
5486 c = snew(struct ssh_channel);
5488 c->remoteid = remoteid;
5489 c->halfopen = FALSE;
5490 c->localid = alloc_channel_id(ssh);
5492 c->pending_eof = FALSE;
5493 c->throttling_conn = 0;
5494 c->type = CHAN_AGENT; /* identify channel type */
5495 c->u.a.lensofar = 0;
5496 c->u.a.message = NULL;
5497 c->u.a.outstanding_requests = 0;
5498 add234(ssh->channels, c);
5499 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5500 PKT_INT, c->remoteid, PKT_INT, c->localid,
5505 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
5507 /* Remote side is trying to open a channel to talk to a
5508 * forwarded port. Give them back a local channel number. */
5509 struct ssh_rportfwd pf, *pfp;
5515 remoteid = ssh_pkt_getuint32(pktin);
5516 ssh_pkt_getstring(pktin, &host, &hostsize);
5517 port = ssh_pkt_getuint32(pktin);
5519 pf.dhost = dupprintf("%.*s", hostsize, host);
5521 pfp = find234(ssh->rportfwds, &pf, NULL);
5524 logeventf(ssh, "Rejected remote port open request for %s:%d",
5526 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5527 PKT_INT, remoteid, PKT_END);
5529 struct ssh_channel *c = snew(struct ssh_channel);
5532 logeventf(ssh, "Received remote port open request for %s:%d",
5534 err = pfd_connect(&c->u.pfd.pf, pf.dhost, port,
5535 c, ssh->conf, pfp->pfrec->addressfamily);
5537 logeventf(ssh, "Port open failed: %s", err);
5540 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5541 PKT_INT, remoteid, PKT_END);
5543 c->remoteid = remoteid;
5544 c->halfopen = FALSE;
5545 c->localid = alloc_channel_id(ssh);
5547 c->pending_eof = FALSE;
5548 c->throttling_conn = 0;
5549 c->type = CHAN_SOCKDATA; /* identify channel type */
5550 add234(ssh->channels, c);
5551 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5552 PKT_INT, c->remoteid, PKT_INT,
5553 c->localid, PKT_END);
5554 logevent("Forwarded port opened successfully");
5561 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5563 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5564 unsigned int localid = ssh_pkt_getuint32(pktin);
5565 struct ssh_channel *c;
5567 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5568 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5569 c->remoteid = localid;
5570 c->halfopen = FALSE;
5571 c->type = CHAN_SOCKDATA;
5572 c->throttling_conn = 0;
5573 pfd_confirm(c->u.pfd.pf);
5576 if (c && c->pending_eof) {
5578 * We have a pending close on this channel,
5579 * which we decided on before the server acked
5580 * the channel open. So now we know the
5581 * remoteid, we can close it again.
5583 ssh_channel_try_eof(c);
5587 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5589 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5590 struct ssh_channel *c;
5592 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5593 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5594 logevent("Forwarded connection refused by server");
5595 pfd_close(c->u.pfd.pf);
5596 del234(ssh->channels, c);
5601 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
5603 /* Remote side closes a channel. */
5604 unsigned i = ssh_pkt_getuint32(pktin);
5605 struct ssh_channel *c;
5606 c = find234(ssh->channels, &i, ssh_channelfind);
5607 if (c && !c->halfopen) {
5609 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
5610 !(c->closes & CLOSES_RCVD_EOF)) {
5612 * Received CHANNEL_CLOSE, which we translate into
5615 int send_close = FALSE;
5617 c->closes |= CLOSES_RCVD_EOF;
5622 x11_send_eof(c->u.x11.xconn);
5628 pfd_send_eof(c->u.pfd.pf);
5637 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
5638 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
5640 c->closes |= CLOSES_SENT_EOF;
5644 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
5645 !(c->closes & CLOSES_RCVD_CLOSE)) {
5647 if (!(c->closes & CLOSES_SENT_EOF)) {
5648 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
5649 " for which we never sent CHANNEL_CLOSE\n", i));
5652 c->closes |= CLOSES_RCVD_CLOSE;
5655 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
5656 !(c->closes & CLOSES_SENT_CLOSE)) {
5657 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
5658 PKT_INT, c->remoteid, PKT_END);
5659 c->closes |= CLOSES_SENT_CLOSE;
5662 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5663 ssh_channel_destroy(c);
5665 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5666 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
5667 "_CONFIRMATION", c ? "half-open" : "nonexistent",
5672 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5674 /* Data sent down one of our channels. */
5675 int i = ssh_pkt_getuint32(pktin);
5678 struct ssh_channel *c;
5680 ssh_pkt_getstring(pktin, &p, &len);
5682 c = find234(ssh->channels, &i, ssh_channelfind);
5687 bufsize = x11_send(c->u.x11.xconn, p, len);
5690 bufsize = pfd_send(c->u.pfd.pf, p, len);
5693 /* Data for an agent message. Buffer it. */
5695 if (c->u.a.lensofar < 4) {
5696 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
5697 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
5701 c->u.a.lensofar += l;
5703 if (c->u.a.lensofar == 4) {
5705 4 + GET_32BIT(c->u.a.msglen);
5706 c->u.a.message = snewn(c->u.a.totallen,
5708 memcpy(c->u.a.message, c->u.a.msglen, 4);
5710 if (c->u.a.lensofar >= 4 && len > 0) {
5712 min(c->u.a.totallen - c->u.a.lensofar,
5714 memcpy(c->u.a.message + c->u.a.lensofar, p,
5718 c->u.a.lensofar += l;
5720 if (c->u.a.lensofar == c->u.a.totallen) {
5723 c->u.a.outstanding_requests++;
5724 if (agent_query(c->u.a.message,
5727 ssh_agentf_callback, c))
5728 ssh_agentf_callback(c, reply, replylen);
5729 sfree(c->u.a.message);
5730 c->u.a.lensofar = 0;
5733 bufsize = 0; /* agent channels never back up */
5736 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5737 c->throttling_conn = 1;
5738 ssh_throttle_conn(ssh, +1);
5743 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5745 ssh->exitcode = ssh_pkt_getuint32(pktin);
5746 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5747 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5749 * In case `helpful' firewalls or proxies tack
5750 * extra human-readable text on the end of the
5751 * session which we might mistake for another
5752 * encrypted packet, we close the session once
5753 * we've sent EXIT_CONFIRMATION.
5755 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5758 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5759 static void ssh1_send_ttymode(void *data, char *mode, char *val)
5761 struct Packet *pktout = (struct Packet *)data;
5763 unsigned int arg = 0;
5764 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5765 if (i == lenof(ssh_ttymodes)) return;
5766 switch (ssh_ttymodes[i].type) {
5768 arg = ssh_tty_parse_specchar(val);
5771 arg = ssh_tty_parse_boolean(val);
5774 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5775 ssh2_pkt_addbyte(pktout, arg);
5778 int ssh_agent_forwarding_permitted(Ssh ssh)
5780 return conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists();
5783 static void do_ssh1_connection(Ssh ssh, const unsigned char *in, int inlen,
5784 struct Packet *pktin)
5786 crBegin(ssh->do_ssh1_connection_crstate);
5788 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5789 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5790 ssh1_smsg_stdout_stderr_data;
5792 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5793 ssh1_msg_channel_open_confirmation;
5794 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5795 ssh1_msg_channel_open_failure;
5796 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5797 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5798 ssh1_msg_channel_close;
5799 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5800 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5802 if (ssh_agent_forwarding_permitted(ssh)) {
5803 logevent("Requesting agent forwarding");
5804 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5808 if (pktin->type != SSH1_SMSG_SUCCESS
5809 && pktin->type != SSH1_SMSG_FAILURE) {
5810 bombout(("Protocol confusion"));
5812 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5813 logevent("Agent forwarding refused");
5815 logevent("Agent forwarding enabled");
5816 ssh->agentfwd_enabled = TRUE;
5817 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5821 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
5823 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5825 if (!ssh->x11disp) {
5826 /* FIXME: return an error message from x11_setup_display */
5827 logevent("X11 forwarding not enabled: unable to"
5828 " initialise X display");
5830 ssh->x11auth = x11_invent_fake_auth
5831 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
5832 ssh->x11auth->disp = ssh->x11disp;
5834 logevent("Requesting X11 forwarding");
5835 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5836 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5837 PKT_STR, ssh->x11auth->protoname,
5838 PKT_STR, ssh->x11auth->datastring,
5839 PKT_INT, ssh->x11disp->screennum,
5842 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5843 PKT_STR, ssh->x11auth->protoname,
5844 PKT_STR, ssh->x11auth->datastring,
5850 if (pktin->type != SSH1_SMSG_SUCCESS
5851 && pktin->type != SSH1_SMSG_FAILURE) {
5852 bombout(("Protocol confusion"));
5854 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5855 logevent("X11 forwarding refused");
5857 logevent("X11 forwarding enabled");
5858 ssh->X11_fwd_enabled = TRUE;
5859 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5864 ssh_setup_portfwd(ssh, ssh->conf);
5865 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5867 if (!conf_get_int(ssh->conf, CONF_nopty)) {
5869 /* Unpick the terminal-speed string. */
5870 /* XXX perhaps we should allow no speeds to be sent. */
5871 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5872 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
5873 /* Send the pty request. */
5874 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5875 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
5876 ssh_pkt_adduint32(pkt, ssh->term_height);
5877 ssh_pkt_adduint32(pkt, ssh->term_width);
5878 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5879 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5880 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
5881 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5882 ssh_pkt_adduint32(pkt, ssh->ispeed);
5883 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5884 ssh_pkt_adduint32(pkt, ssh->ospeed);
5885 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5887 ssh->state = SSH_STATE_INTERMED;
5891 if (pktin->type != SSH1_SMSG_SUCCESS
5892 && pktin->type != SSH1_SMSG_FAILURE) {
5893 bombout(("Protocol confusion"));
5895 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5896 c_write_str(ssh, "Server refused to allocate pty\r\n");
5897 ssh->editing = ssh->echoing = 1;
5899 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5900 ssh->ospeed, ssh->ispeed);
5901 ssh->got_pty = TRUE;
5904 ssh->editing = ssh->echoing = 1;
5907 if (conf_get_int(ssh->conf, CONF_compression)) {
5908 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5912 if (pktin->type != SSH1_SMSG_SUCCESS
5913 && pktin->type != SSH1_SMSG_FAILURE) {
5914 bombout(("Protocol confusion"));
5916 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5917 c_write_str(ssh, "Server refused to compress\r\n");
5919 logevent("Started compression");
5920 ssh->v1_compressing = TRUE;
5921 ssh->cs_comp_ctx = zlib_compress_init();
5922 logevent("Initialised zlib (RFC1950) compression");
5923 ssh->sc_comp_ctx = zlib_decompress_init();
5924 logevent("Initialised zlib (RFC1950) decompression");
5928 * Start the shell or command.
5930 * Special case: if the first-choice command is an SSH-2
5931 * subsystem (hence not usable here) and the second choice
5932 * exists, we fall straight back to that.
5935 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
5937 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
5938 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
5939 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
5940 ssh->fallback_cmd = TRUE;
5943 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
5945 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
5946 logevent("Started session");
5949 ssh->state = SSH_STATE_SESSION;
5950 if (ssh->size_needed)
5951 ssh_size(ssh, ssh->term_width, ssh->term_height);
5952 if (ssh->eof_needed)
5953 ssh_special(ssh, TS_EOF);
5956 ldisc_echoedit_update(ssh->ldisc); /* cause ldisc to notice changes */
5958 ssh->channels = newtree234(ssh_channelcmp);
5962 * By this point, most incoming packets are already being
5963 * handled by the dispatch table, and we need only pay
5964 * attention to the unusual ones.
5969 if (pktin->type == SSH1_SMSG_SUCCESS) {
5970 /* may be from EXEC_SHELL on some servers */
5971 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5972 /* may be from EXEC_SHELL on some servers
5973 * if no pty is available or in other odd cases. Ignore */
5975 bombout(("Strange packet received: type %d", pktin->type));
5980 int len = min(inlen, 512);
5981 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
5982 PKT_INT, len, PKT_DATA, in, len,
5994 * Handle the top-level SSH-2 protocol.
5996 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
6001 ssh_pkt_getstring(pktin, &msg, &msglen);
6002 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
6005 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
6007 /* log reason code in disconnect message */
6011 ssh_pkt_getstring(pktin, &msg, &msglen);
6012 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
6015 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
6017 /* Do nothing, because we're ignoring it! Duhh. */
6020 static void ssh1_protocol_setup(Ssh ssh)
6025 * Most messages are handled by the coroutines.
6027 for (i = 0; i < 256; i++)
6028 ssh->packet_dispatch[i] = NULL;
6031 * These special message types we install handlers for.
6033 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
6034 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
6035 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
6038 static void ssh1_protocol(Ssh ssh, const void *vin, int inlen,
6039 struct Packet *pktin)
6041 const unsigned char *in = (const unsigned char *)vin;
6042 if (ssh->state == SSH_STATE_CLOSED)
6045 if (pktin && ssh->packet_dispatch[pktin->type]) {
6046 ssh->packet_dispatch[pktin->type](ssh, pktin);
6050 if (!ssh->protocol_initial_phase_done) {
6051 if (do_ssh1_login(ssh, in, inlen, pktin))
6052 ssh->protocol_initial_phase_done = TRUE;
6057 do_ssh1_connection(ssh, in, inlen, pktin);
6061 * Utility routines for decoding comma-separated strings in KEXINIT.
6063 static int first_in_commasep_string(char const *needle, char const *haystack,
6067 if (!needle || !haystack) /* protect against null pointers */
6069 needlen = strlen(needle);
6071 if (haylen >= needlen && /* haystack is long enough */
6072 !memcmp(needle, haystack, needlen) && /* initial match */
6073 (haylen == needlen || haystack[needlen] == ',')
6074 /* either , or EOS follows */
6080 static int in_commasep_string(char const *needle, char const *haystack,
6085 if (!needle || !haystack) /* protect against null pointers */
6088 * Is it at the start of the string?
6090 if (first_in_commasep_string(needle, haystack, haylen))
6093 * If not, search for the next comma and resume after that.
6094 * If no comma found, terminate.
6096 p = memchr(haystack, ',', haylen);
6098 /* + 1 to skip over comma */
6099 return in_commasep_string(needle, p + 1, haylen - (p + 1 - haystack));
6103 * Add a value to the comma-separated string at the end of the packet.
6104 * If the value is already in the string, don't bother adding it again.
6106 static void ssh2_pkt_addstring_commasep(struct Packet *pkt, const char *data)
6108 if (in_commasep_string(data, (char *)pkt->data + pkt->savedpos,
6109 pkt->length - pkt->savedpos)) return;
6110 if (pkt->length - pkt->savedpos > 0)
6111 ssh_pkt_addstring_str(pkt, ",");
6112 ssh_pkt_addstring_str(pkt, data);
6117 * SSH-2 key creation method.
6118 * (Currently assumes 2 lots of any hash are sufficient to generate
6119 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
6121 #define SSH2_MKKEY_ITERS (2)
6122 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
6123 unsigned char *keyspace)
6125 const struct ssh_hash *h = ssh->kex->hash;
6127 /* First hlen bytes. */
6129 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6130 hash_mpint(h, s, K);
6131 h->bytes(s, H, h->hlen);
6132 h->bytes(s, &chr, 1);
6133 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
6134 h->final(s, keyspace);
6135 /* Next hlen bytes. */
6137 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6138 hash_mpint(h, s, K);
6139 h->bytes(s, H, h->hlen);
6140 h->bytes(s, keyspace, h->hlen);
6141 h->final(s, keyspace + h->hlen);
6145 * Handle the SSH-2 transport layer.
6147 static void do_ssh2_transport(Ssh ssh, const void *vin, int inlen,
6148 struct Packet *pktin)
6150 const unsigned char *in = (const unsigned char *)vin;
6152 KEXLIST_KEX, KEXLIST_HOSTKEY, KEXLIST_CSCIPHER, KEXLIST_SCCIPHER,
6153 KEXLIST_CSMAC, KEXLIST_SCMAC, KEXLIST_CSCOMP, KEXLIST_SCCOMP,
6156 const char * kexlist_descr[NKEXLIST] = {
6157 "key exchange algorithm", "host key algorithm",
6158 "client-to-server cipher", "server-to-client cipher",
6159 "client-to-server MAC", "server-to-client MAC",
6160 "client-to-server compression method",
6161 "server-to-client compression method" };
6162 struct do_ssh2_transport_state {
6164 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
6165 Bignum p, g, e, f, K;
6168 int kex_init_value, kex_reply_value;
6169 const struct ssh_mac **maclist;
6171 const struct ssh2_cipher *cscipher_tobe;
6172 const struct ssh2_cipher *sccipher_tobe;
6173 const struct ssh_mac *csmac_tobe;
6174 const struct ssh_mac *scmac_tobe;
6175 int csmac_etm_tobe, scmac_etm_tobe;
6176 const struct ssh_compress *cscomp_tobe;
6177 const struct ssh_compress *sccomp_tobe;
6178 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
6179 int hostkeylen, siglen, rsakeylen;
6180 void *hkey; /* actual host key */
6181 void *rsakey; /* for RSA kex */
6182 void *eckey; /* for ECDH kex */
6183 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
6184 int n_preferred_kex;
6185 const struct ssh_kexes *preferred_kex[KEX_MAX];
6186 int n_preferred_ciphers;
6187 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
6188 const struct ssh_compress *preferred_comp;
6189 int userauth_succeeded; /* for delayed compression */
6190 int pending_compression;
6191 int got_session_id, activated_authconn;
6192 struct Packet *pktout;
6196 #define MAXKEXLIST 16
6197 struct kexinit_algorithm {
6201 const struct ssh_kex *kex;
6204 const struct ssh_signkey *hostkey;
6206 const struct ssh2_cipher *cipher;
6210 const struct ssh_mac *mac;
6213 const struct ssh_compress *comp;
6215 } kexlists[NKEXLIST][MAXKEXLIST];
6217 crState(do_ssh2_transport_state);
6219 assert(!ssh->bare_connection);
6223 s->cscipher_tobe = s->sccipher_tobe = NULL;
6224 s->csmac_tobe = s->scmac_tobe = NULL;
6225 s->cscomp_tobe = s->sccomp_tobe = NULL;
6227 s->got_session_id = s->activated_authconn = FALSE;
6228 s->userauth_succeeded = FALSE;
6229 s->pending_compression = FALSE;
6232 * Be prepared to work around the buggy MAC problem.
6234 if (ssh->remote_bugs & BUG_SSH2_HMAC)
6235 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
6237 s->maclist = macs, s->nmacs = lenof(macs);
6240 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
6242 int i, j, k, n, warn;
6245 * Set up the preferred key exchange. (NULL => warn below here)
6247 s->n_preferred_kex = 0;
6248 for (i = 0; i < KEX_MAX; i++) {
6249 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
6251 s->preferred_kex[s->n_preferred_kex++] =
6252 &ssh_diffiehellman_gex;
6255 s->preferred_kex[s->n_preferred_kex++] =
6256 &ssh_diffiehellman_group14;
6259 s->preferred_kex[s->n_preferred_kex++] =
6260 &ssh_diffiehellman_group1;
6263 s->preferred_kex[s->n_preferred_kex++] =
6267 s->preferred_kex[s->n_preferred_kex++] =
6271 /* Flag for later. Don't bother if it's the last in
6273 if (i < KEX_MAX - 1) {
6274 s->preferred_kex[s->n_preferred_kex++] = NULL;
6281 * Set up the preferred ciphers. (NULL => warn below here)
6283 s->n_preferred_ciphers = 0;
6284 for (i = 0; i < CIPHER_MAX; i++) {
6285 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
6286 case CIPHER_BLOWFISH:
6287 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
6290 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
6291 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
6295 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
6298 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
6300 case CIPHER_ARCFOUR:
6301 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
6304 /* Flag for later. Don't bother if it's the last in
6306 if (i < CIPHER_MAX - 1) {
6307 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
6314 * Set up preferred compression.
6316 if (conf_get_int(ssh->conf, CONF_compression))
6317 s->preferred_comp = &ssh_zlib;
6319 s->preferred_comp = &ssh_comp_none;
6322 * Enable queueing of outgoing auth- or connection-layer
6323 * packets while we are in the middle of a key exchange.
6325 ssh->queueing = TRUE;
6328 * Flag that KEX is in progress.
6330 ssh->kex_in_progress = TRUE;
6332 for (i = 0; i < NKEXLIST; i++)
6333 for (j = 0; j < MAXKEXLIST; j++)
6334 s->kexlists[i][j].name = NULL;
6335 /* List key exchange algorithms. */
6338 for (i = 0; i < s->n_preferred_kex; i++) {
6339 const struct ssh_kexes *k = s->preferred_kex[i];
6340 if (!k) warn = TRUE;
6341 else for (j = 0; j < k->nkexes; j++) {
6342 assert(n < MAXKEXLIST);
6343 s->kexlists[KEXLIST_KEX][n].name = k->list[j]->name;
6344 s->kexlists[KEXLIST_KEX][n].u.kex.kex = k->list[j];
6345 s->kexlists[KEXLIST_KEX][n].u.kex.warn = warn;
6349 /* List server host key algorithms. */
6350 if (!s->got_session_id) {
6352 * In the first key exchange, we list all the algorithms
6353 * we're prepared to cope with.
6356 for (i = 0; i < lenof(hostkey_algs); i++) {
6357 assert(n < MAXKEXLIST);
6358 s->kexlists[KEXLIST_HOSTKEY][n].name = hostkey_algs[i]->name;
6359 s->kexlists[KEXLIST_HOSTKEY][n].u.hostkey = hostkey_algs[i];
6364 * In subsequent key exchanges, we list only the kex
6365 * algorithm that was selected in the first key exchange,
6366 * so that we keep getting the same host key and hence
6367 * don't have to interrupt the user's session to ask for
6371 s->kexlists[KEXLIST_HOSTKEY][0].name = ssh->hostkey->name;
6372 s->kexlists[KEXLIST_HOSTKEY][0].u.hostkey = ssh->hostkey;
6374 /* List encryption algorithms (client->server then server->client). */
6375 for (k = KEXLIST_CSCIPHER; k <= KEXLIST_SCCIPHER; k++) {
6378 for (i = 0; i < s->n_preferred_ciphers; i++) {
6379 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6380 if (!c) warn = TRUE;
6381 else for (j = 0; j < c->nciphers; j++) {
6382 assert(n < MAXKEXLIST);
6383 s->kexlists[k][n].name = c->list[j]->name;
6384 s->kexlists[k][n].u.cipher.cipher = c->list[j];
6385 s->kexlists[k][n].u.cipher.warn = warn;
6390 /* List MAC algorithms (client->server then server->client). */
6391 for (j = KEXLIST_CSMAC; j <= KEXLIST_SCMAC; j++) {
6393 for (i = 0; i < s->nmacs; i++) {
6394 assert(n < MAXKEXLIST);
6395 s->kexlists[j][n].name = s->maclist[i]->name;
6396 s->kexlists[j][n].u.mac.mac = s->maclist[i];
6397 s->kexlists[j][n].u.mac.etm = FALSE;
6400 for (i = 0; i < s->nmacs; i++)
6401 /* For each MAC, there may also be an ETM version,
6402 * which we list second. */
6403 if (s->maclist[i]->etm_name) {
6404 assert(n < MAXKEXLIST);
6405 s->kexlists[j][n].name = s->maclist[i]->etm_name;
6406 s->kexlists[j][n].u.mac.mac = s->maclist[i];
6407 s->kexlists[j][n].u.mac.etm = TRUE;
6411 /* List client->server compression algorithms,
6412 * then server->client compression algorithms. (We use the
6413 * same set twice.) */
6414 for (j = KEXLIST_CSCOMP; j <= KEXLIST_SCCOMP; j++) {
6415 assert(lenof(compressions) > 1);
6416 /* Prefer non-delayed versions */
6417 s->kexlists[j][0].name = s->preferred_comp->name;
6418 s->kexlists[j][0].u.comp = s->preferred_comp;
6419 /* We don't even list delayed versions of algorithms until
6420 * they're allowed to be used, to avoid a race. See the end of
6423 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
6424 s->kexlists[j][1].name = s->preferred_comp->delayed_name;
6425 s->kexlists[j][1].u.comp = s->preferred_comp;
6428 for (i = 0; i < lenof(compressions); i++) {
6429 const struct ssh_compress *c = compressions[i];
6430 s->kexlists[j][n].name = c->name;
6431 s->kexlists[j][n].u.comp = c;
6433 if (s->userauth_succeeded && c->delayed_name) {
6434 s->kexlists[j][n].name = c->delayed_name;
6435 s->kexlists[j][n].u.comp = c;
6441 * Construct and send our key exchange packet.
6443 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
6444 for (i = 0; i < 16; i++)
6445 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
6446 for (i = 0; i < NKEXLIST; i++) {
6447 ssh2_pkt_addstring_start(s->pktout);
6448 for (j = 0; j < MAXKEXLIST; j++) {
6449 if (s->kexlists[i][j].name == NULL) break;
6450 ssh2_pkt_addstring_commasep(s->pktout, s->kexlists[i][j].name);
6453 /* List client->server languages. Empty list. */
6454 ssh2_pkt_addstring_start(s->pktout);
6455 /* List server->client languages. Empty list. */
6456 ssh2_pkt_addstring_start(s->pktout);
6457 /* First KEX packet does _not_ follow, because we're not that brave. */
6458 ssh2_pkt_addbool(s->pktout, FALSE);
6460 ssh2_pkt_adduint32(s->pktout, 0);
6463 s->our_kexinitlen = s->pktout->length - 5;
6464 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
6465 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
6467 ssh2_pkt_send_noqueue(ssh, s->pktout);
6470 crWaitUntilV(pktin);
6473 * Now examine the other side's KEXINIT to see what we're up
6480 if (pktin->type != SSH2_MSG_KEXINIT) {
6481 bombout(("expected key exchange packet from server"));
6485 ssh->hostkey = NULL;
6486 s->cscipher_tobe = NULL;
6487 s->sccipher_tobe = NULL;
6488 s->csmac_tobe = NULL;
6489 s->scmac_tobe = NULL;
6490 s->cscomp_tobe = NULL;
6491 s->sccomp_tobe = NULL;
6492 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
6494 pktin->savedpos += 16; /* skip garbage cookie */
6497 for (i = 0; i < NKEXLIST; i++) {
6498 ssh_pkt_getstring(pktin, &str, &len);
6500 bombout(("KEXINIT packet was incomplete"));
6503 for (j = 0; j < MAXKEXLIST; j++) {
6504 struct kexinit_algorithm *alg = &s->kexlists[i][j];
6505 if (alg->name == NULL) break;
6506 if (in_commasep_string(alg->name, str, len)) {
6507 /* We've found a matching algorithm. */
6508 if (i == KEXLIST_KEX || i == KEXLIST_HOSTKEY) {
6509 /* Check if we might need to ignore first kex pkt */
6511 !first_in_commasep_string(alg->name, str, len))
6514 if (i == KEXLIST_KEX) {
6515 ssh->kex = alg->u.kex.kex;
6516 s->warn_kex = alg->u.kex.warn;
6517 } else if (i == KEXLIST_HOSTKEY) {
6518 ssh->hostkey = alg->u.hostkey;
6519 } else if (i == KEXLIST_CSCIPHER) {
6520 s->cscipher_tobe = alg->u.cipher.cipher;
6521 s->warn_cscipher = alg->u.cipher.warn;
6522 } else if (i == KEXLIST_SCCIPHER) {
6523 s->sccipher_tobe = alg->u.cipher.cipher;
6524 s->warn_sccipher = alg->u.cipher.warn;
6525 } else if (i == KEXLIST_CSMAC) {
6526 s->csmac_tobe = alg->u.mac.mac;
6527 s->csmac_etm_tobe = alg->u.mac.etm;
6528 } else if (i == KEXLIST_SCMAC) {
6529 s->scmac_tobe = alg->u.mac.mac;
6530 s->scmac_etm_tobe = alg->u.mac.etm;
6531 } else if (i == KEXLIST_CSCOMP) {
6532 s->cscomp_tobe = alg->u.comp;
6533 } else if (i == KEXLIST_SCCOMP) {
6534 s->sccomp_tobe = alg->u.comp;
6538 if ((i == KEXLIST_CSCOMP || i == KEXLIST_SCCOMP) &&
6539 in_commasep_string(alg->u.comp->delayed_name, str, len))
6540 s->pending_compression = TRUE; /* try this later */
6542 bombout(("Couldn't agree a %s ((available: %.*s)",
6543 kexlist_descr[i], len, str));
6547 if (s->pending_compression) {
6548 logevent("Server supports delayed compression; "
6549 "will try this later");
6551 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
6552 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
6553 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
6555 ssh->exhash = ssh->kex->hash->init();
6556 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
6557 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
6558 hash_string(ssh->kex->hash, ssh->exhash,
6559 s->our_kexinit, s->our_kexinitlen);
6560 sfree(s->our_kexinit);
6561 /* Include the type byte in the hash of server's KEXINIT */
6562 hash_string(ssh->kex->hash, ssh->exhash,
6563 pktin->body - 1, pktin->length + 1);
6566 ssh_set_frozen(ssh, 1);
6567 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
6569 ssh_dialog_callback, ssh);
6570 if (s->dlgret < 0) {
6574 bombout(("Unexpected data from server while"
6575 " waiting for user response"));
6578 } while (pktin || inlen > 0);
6579 s->dlgret = ssh->user_response;
6581 ssh_set_frozen(ssh, 0);
6582 if (s->dlgret == 0) {
6583 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
6589 if (s->warn_cscipher) {
6590 ssh_set_frozen(ssh, 1);
6591 s->dlgret = askalg(ssh->frontend,
6592 "client-to-server cipher",
6593 s->cscipher_tobe->name,
6594 ssh_dialog_callback, ssh);
6595 if (s->dlgret < 0) {
6599 bombout(("Unexpected data from server while"
6600 " waiting for user response"));
6603 } while (pktin || inlen > 0);
6604 s->dlgret = ssh->user_response;
6606 ssh_set_frozen(ssh, 0);
6607 if (s->dlgret == 0) {
6608 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6614 if (s->warn_sccipher) {
6615 ssh_set_frozen(ssh, 1);
6616 s->dlgret = askalg(ssh->frontend,
6617 "server-to-client cipher",
6618 s->sccipher_tobe->name,
6619 ssh_dialog_callback, ssh);
6620 if (s->dlgret < 0) {
6624 bombout(("Unexpected data from server while"
6625 " waiting for user response"));
6628 } while (pktin || inlen > 0);
6629 s->dlgret = ssh->user_response;
6631 ssh_set_frozen(ssh, 0);
6632 if (s->dlgret == 0) {
6633 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6639 if (s->ignorepkt) /* first_kex_packet_follows */
6640 crWaitUntilV(pktin); /* Ignore packet */
6643 if (ssh->kex->main_type == KEXTYPE_DH) {
6645 * Work out the number of bits of key we will need from the
6646 * key exchange. We start with the maximum key length of
6652 csbits = s->cscipher_tobe->keylen;
6653 scbits = s->sccipher_tobe->keylen;
6654 s->nbits = (csbits > scbits ? csbits : scbits);
6656 /* The keys only have hlen-bit entropy, since they're based on
6657 * a hash. So cap the key size at hlen bits. */
6658 if (s->nbits > ssh->kex->hash->hlen * 8)
6659 s->nbits = ssh->kex->hash->hlen * 8;
6662 * If we're doing Diffie-Hellman group exchange, start by
6663 * requesting a group.
6665 if (dh_is_gex(ssh->kex)) {
6666 logevent("Doing Diffie-Hellman group exchange");
6667 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
6669 * Work out how big a DH group we will need to allow that
6672 s->pbits = 512 << ((s->nbits - 1) / 64);
6673 if (s->pbits < DH_MIN_SIZE)
6674 s->pbits = DH_MIN_SIZE;
6675 if (s->pbits > DH_MAX_SIZE)
6676 s->pbits = DH_MAX_SIZE;
6677 if ((ssh->remote_bugs & BUG_SSH2_OLDGEX)) {
6678 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST_OLD);
6679 ssh2_pkt_adduint32(s->pktout, s->pbits);
6681 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6682 ssh2_pkt_adduint32(s->pktout, DH_MIN_SIZE);
6683 ssh2_pkt_adduint32(s->pktout, s->pbits);
6684 ssh2_pkt_adduint32(s->pktout, DH_MAX_SIZE);
6686 ssh2_pkt_send_noqueue(ssh, s->pktout);
6688 crWaitUntilV(pktin);
6689 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6690 bombout(("expected key exchange group packet from server"));
6693 s->p = ssh2_pkt_getmp(pktin);
6694 s->g = ssh2_pkt_getmp(pktin);
6695 if (!s->p || !s->g) {
6696 bombout(("unable to read mp-ints from incoming group packet"));
6699 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6700 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6701 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6703 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
6704 ssh->kex_ctx = dh_setup_group(ssh->kex);
6705 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6706 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6707 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6708 ssh->kex->groupname);
6711 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6712 ssh->kex->hash->text_name);
6714 * Now generate and send e for Diffie-Hellman.
6716 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6717 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6718 s->pktout = ssh2_pkt_init(s->kex_init_value);
6719 ssh2_pkt_addmp(s->pktout, s->e);
6720 ssh2_pkt_send_noqueue(ssh, s->pktout);
6722 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
6723 crWaitUntilV(pktin);
6724 if (pktin->type != s->kex_reply_value) {
6725 bombout(("expected key exchange reply packet from server"));
6728 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
6729 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6730 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
6731 s->hostkeydata, s->hostkeylen);
6732 s->f = ssh2_pkt_getmp(pktin);
6734 bombout(("unable to parse key exchange reply packet"));
6737 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6740 const char *err = dh_validate_f(ssh->kex_ctx, s->f);
6742 bombout(("key exchange reply failed validation: %s", err));
6746 s->K = dh_find_K(ssh->kex_ctx, s->f);
6748 /* We assume everything from now on will be quick, and it might
6749 * involve user interaction. */
6750 set_busy_status(ssh->frontend, BUSY_NOT);
6752 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6753 if (dh_is_gex(ssh->kex)) {
6754 if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX))
6755 hash_uint32(ssh->kex->hash, ssh->exhash, DH_MIN_SIZE);
6756 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
6757 if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX))
6758 hash_uint32(ssh->kex->hash, ssh->exhash, DH_MAX_SIZE);
6759 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
6760 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
6762 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
6763 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
6765 dh_cleanup(ssh->kex_ctx);
6767 if (dh_is_gex(ssh->kex)) {
6771 } else if (ssh->kex->main_type == KEXTYPE_ECDH) {
6773 logeventf(ssh, "Doing ECDH key exchange with curve %s and hash %s",
6774 ssh_ecdhkex_curve_textname(ssh->kex),
6775 ssh->kex->hash->text_name);
6776 ssh->pkt_kctx = SSH2_PKTCTX_ECDHKEX;
6778 s->eckey = ssh_ecdhkex_newkey(ssh->kex);
6780 bombout(("Unable to generate key for ECDH"));
6786 int publicPointLength;
6787 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
6789 ssh_ecdhkex_freekey(s->eckey);
6790 bombout(("Unable to encode public key for ECDH"));
6793 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_ECDH_INIT);
6794 ssh2_pkt_addstring_start(s->pktout);
6795 ssh2_pkt_addstring_data(s->pktout, publicPoint, publicPointLength);
6799 ssh2_pkt_send_noqueue(ssh, s->pktout);
6801 crWaitUntilV(pktin);
6802 if (pktin->type != SSH2_MSG_KEX_ECDH_REPLY) {
6803 ssh_ecdhkex_freekey(s->eckey);
6804 bombout(("expected ECDH reply packet from server"));
6808 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6809 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6810 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
6811 s->hostkeydata, s->hostkeylen);
6815 int publicPointLength;
6816 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
6818 ssh_ecdhkex_freekey(s->eckey);
6819 bombout(("Unable to encode public key for ECDH hash"));
6822 hash_string(ssh->kex->hash, ssh->exhash,
6823 publicPoint, publicPointLength);
6830 ssh_pkt_getstring(pktin, &keydata, &keylen);
6831 hash_string(ssh->kex->hash, ssh->exhash, keydata, keylen);
6832 s->K = ssh_ecdhkex_getkey(s->eckey, keydata, keylen);
6834 ssh_ecdhkex_freekey(s->eckey);
6835 bombout(("point received in ECDH was not valid"));
6840 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6842 ssh_ecdhkex_freekey(s->eckey);
6844 logeventf(ssh, "Doing RSA key exchange with hash %s",
6845 ssh->kex->hash->text_name);
6846 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
6848 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6851 crWaitUntilV(pktin);
6852 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
6853 bombout(("expected RSA public key packet from server"));
6857 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6858 hash_string(ssh->kex->hash, ssh->exhash,
6859 s->hostkeydata, s->hostkeylen);
6860 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
6861 s->hostkeydata, s->hostkeylen);
6865 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
6866 s->rsakeydata = snewn(s->rsakeylen, char);
6867 memcpy(s->rsakeydata, keydata, s->rsakeylen);
6870 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
6872 sfree(s->rsakeydata);
6873 bombout(("unable to parse RSA public key from server"));
6877 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
6880 * Next, set up a shared secret K, of precisely KLEN -
6881 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6882 * RSA key modulus and HLEN is the bit length of the hash
6886 int klen = ssh_rsakex_klen(s->rsakey);
6887 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
6889 unsigned char *kstr1, *kstr2, *outstr;
6890 int kstr1len, kstr2len, outstrlen;
6892 s->K = bn_power_2(nbits - 1);
6894 for (i = 0; i < nbits; i++) {
6896 byte = random_byte();
6898 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
6902 * Encode this as an mpint.
6904 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
6905 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
6906 PUT_32BIT(kstr2, kstr1len);
6907 memcpy(kstr2 + 4, kstr1, kstr1len);
6910 * Encrypt it with the given RSA key.
6912 outstrlen = (klen + 7) / 8;
6913 outstr = snewn(outstrlen, unsigned char);
6914 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
6915 outstr, outstrlen, s->rsakey);
6918 * And send it off in a return packet.
6920 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
6921 ssh2_pkt_addstring_start(s->pktout);
6922 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
6923 ssh2_pkt_send_noqueue(ssh, s->pktout);
6925 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
6932 ssh_rsakex_freekey(s->rsakey);
6934 crWaitUntilV(pktin);
6935 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
6936 sfree(s->rsakeydata);
6937 bombout(("expected signature packet from server"));
6941 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6943 sfree(s->rsakeydata);
6946 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
6947 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
6948 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
6950 ssh->kex_ctx = NULL;
6953 debug(("Exchange hash is:\n"));
6954 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
6958 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
6959 (char *)s->exchange_hash,
6960 ssh->kex->hash->hlen)) {
6961 bombout(("Server's host key did not match the signature supplied"));
6965 s->keystr = ssh->hostkey->fmtkey(s->hkey);
6966 if (!s->got_session_id) {
6968 * Authenticate remote host: verify host key. (We've already
6969 * checked the signature of the exchange hash.)
6971 s->fingerprint = ssh2_fingerprint(ssh->hostkey, s->hkey);
6972 logevent("Host key fingerprint is:");
6973 logevent(s->fingerprint);
6974 /* First check against manually configured host keys. */
6975 s->dlgret = verify_ssh_manual_host_key(ssh, s->fingerprint,
6976 ssh->hostkey, s->hkey);
6977 if (s->dlgret == 0) { /* did not match */
6978 bombout(("Host key did not appear in manually configured list"));
6980 } else if (s->dlgret < 0) { /* none configured; use standard handling */
6981 ssh_set_frozen(ssh, 1);
6982 s->dlgret = verify_ssh_host_key(ssh->frontend,
6983 ssh->savedhost, ssh->savedport,
6984 ssh->hostkey->keytype, s->keystr,
6986 ssh_dialog_callback, ssh);
6987 if (s->dlgret < 0) {
6991 bombout(("Unexpected data from server while waiting"
6992 " for user host key response"));
6995 } while (pktin || inlen > 0);
6996 s->dlgret = ssh->user_response;
6998 ssh_set_frozen(ssh, 0);
6999 if (s->dlgret == 0) {
7000 ssh_disconnect(ssh, "Aborted at host key verification", NULL,
7005 sfree(s->fingerprint);
7007 * Save this host key, to check against the one presented in
7008 * subsequent rekeys.
7010 ssh->hostkey_str = s->keystr;
7013 * In a rekey, we never present an interactive host key
7014 * verification request to the user. Instead, we simply
7015 * enforce that the key we're seeing this time is identical to
7016 * the one we saw before.
7018 if (strcmp(ssh->hostkey_str, s->keystr)) {
7019 bombout(("Host key was different in repeat key exchange"));
7024 ssh->hostkey->freekey(s->hkey);
7027 * The exchange hash from the very first key exchange is also
7028 * the session id, used in session key construction and
7031 if (!s->got_session_id) {
7032 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
7033 memcpy(ssh->v2_session_id, s->exchange_hash,
7034 sizeof(s->exchange_hash));
7035 ssh->v2_session_id_len = ssh->kex->hash->hlen;
7036 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
7037 s->got_session_id = TRUE;
7041 * Send SSH2_MSG_NEWKEYS.
7043 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
7044 ssh2_pkt_send_noqueue(ssh, s->pktout);
7045 ssh->outgoing_data_size = 0; /* start counting from here */
7048 * We've sent client NEWKEYS, so create and initialise
7049 * client-to-server session keys.
7051 if (ssh->cs_cipher_ctx)
7052 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7053 ssh->cscipher = s->cscipher_tobe;
7054 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
7056 if (ssh->cs_mac_ctx)
7057 ssh->csmac->free_context(ssh->cs_mac_ctx);
7058 ssh->csmac = s->csmac_tobe;
7059 ssh->csmac_etm = s->csmac_etm_tobe;
7060 ssh->cs_mac_ctx = ssh->csmac->make_context();
7062 if (ssh->cs_comp_ctx)
7063 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7064 ssh->cscomp = s->cscomp_tobe;
7065 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
7068 * Set IVs on client-to-server keys. Here we use the exchange
7069 * hash from the _first_ key exchange.
7072 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
7073 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7074 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
7075 assert((ssh->cscipher->keylen+7) / 8 <=
7076 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7077 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
7078 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
7079 assert(ssh->cscipher->blksize <=
7080 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7081 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
7082 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
7083 assert(ssh->csmac->len <=
7084 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7085 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
7086 smemclr(keyspace, sizeof(keyspace));
7089 logeventf(ssh, "Initialised %.200s client->server encryption",
7090 ssh->cscipher->text_name);
7091 logeventf(ssh, "Initialised %.200s client->server MAC algorithm%s",
7092 ssh->csmac->text_name,
7093 ssh->csmac_etm ? " (in ETM mode)" : "");
7094 if (ssh->cscomp->text_name)
7095 logeventf(ssh, "Initialised %s compression",
7096 ssh->cscomp->text_name);
7099 * Now our end of the key exchange is complete, we can send all
7100 * our queued higher-layer packets.
7102 ssh->queueing = FALSE;
7103 ssh2_pkt_queuesend(ssh);
7106 * Expect SSH2_MSG_NEWKEYS from server.
7108 crWaitUntilV(pktin);
7109 if (pktin->type != SSH2_MSG_NEWKEYS) {
7110 bombout(("expected new-keys packet from server"));
7113 ssh->incoming_data_size = 0; /* start counting from here */
7116 * We've seen server NEWKEYS, so create and initialise
7117 * server-to-client session keys.
7119 if (ssh->sc_cipher_ctx)
7120 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7121 ssh->sccipher = s->sccipher_tobe;
7122 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
7124 if (ssh->sc_mac_ctx)
7125 ssh->scmac->free_context(ssh->sc_mac_ctx);
7126 ssh->scmac = s->scmac_tobe;
7127 ssh->scmac_etm = s->scmac_etm_tobe;
7128 ssh->sc_mac_ctx = ssh->scmac->make_context();
7130 if (ssh->sc_comp_ctx)
7131 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7132 ssh->sccomp = s->sccomp_tobe;
7133 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
7136 * Set IVs on server-to-client keys. Here we use the exchange
7137 * hash from the _first_ key exchange.
7140 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
7141 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7142 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
7143 assert((ssh->sccipher->keylen+7) / 8 <=
7144 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7145 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
7146 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
7147 assert(ssh->sccipher->blksize <=
7148 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7149 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
7150 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
7151 assert(ssh->scmac->len <=
7152 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7153 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
7154 smemclr(keyspace, sizeof(keyspace));
7156 logeventf(ssh, "Initialised %.200s server->client encryption",
7157 ssh->sccipher->text_name);
7158 logeventf(ssh, "Initialised %.200s server->client MAC algorithm%s",
7159 ssh->scmac->text_name,
7160 ssh->scmac_etm ? " (in ETM mode)" : "");
7161 if (ssh->sccomp->text_name)
7162 logeventf(ssh, "Initialised %s decompression",
7163 ssh->sccomp->text_name);
7166 * Free shared secret.
7171 * Key exchange is over. Loop straight back round if we have a
7172 * deferred rekey reason.
7174 if (ssh->deferred_rekey_reason) {
7175 logevent(ssh->deferred_rekey_reason);
7177 ssh->deferred_rekey_reason = NULL;
7178 goto begin_key_exchange;
7182 * Otherwise, schedule a timer for our next rekey.
7184 ssh->kex_in_progress = FALSE;
7185 ssh->last_rekey = GETTICKCOUNT();
7186 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
7187 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7191 * Now we're encrypting. Begin returning 1 to the protocol main
7192 * function so that other things can run on top of the
7193 * transport. If we ever see a KEXINIT, we must go back to the
7196 * We _also_ go back to the start if we see pktin==NULL and
7197 * inlen negative, because this is a special signal meaning
7198 * `initiate client-driven rekey', and `in' contains a message
7199 * giving the reason for the rekey.
7201 * inlen==-1 means always initiate a rekey;
7202 * inlen==-2 means that userauth has completed successfully and
7203 * we should consider rekeying (for delayed compression).
7205 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
7206 (!pktin && inlen < 0))) {
7208 if (!ssh->protocol_initial_phase_done) {
7209 ssh->protocol_initial_phase_done = TRUE;
7211 * Allow authconn to initialise itself.
7213 do_ssh2_authconn(ssh, NULL, 0, NULL);
7218 logevent("Server initiated key re-exchange");
7222 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
7223 * delayed compression, if it's available.
7225 * draft-miller-secsh-compression-delayed-00 says that you
7226 * negotiate delayed compression in the first key exchange, and
7227 * both sides start compressing when the server has sent
7228 * USERAUTH_SUCCESS. This has a race condition -- the server
7229 * can't know when the client has seen it, and thus which incoming
7230 * packets it should treat as compressed.
7232 * Instead, we do the initial key exchange without offering the
7233 * delayed methods, but note if the server offers them; when we
7234 * get here, if a delayed method was available that was higher
7235 * on our list than what we got, we initiate a rekey in which we
7236 * _do_ list the delayed methods (and hopefully get it as a
7237 * result). Subsequent rekeys will do the same.
7239 assert(!s->userauth_succeeded); /* should only happen once */
7240 s->userauth_succeeded = TRUE;
7241 if (!s->pending_compression)
7242 /* Can't see any point rekeying. */
7243 goto wait_for_rekey; /* this is utterly horrid */
7244 /* else fall through to rekey... */
7245 s->pending_compression = FALSE;
7248 * Now we've decided to rekey.
7250 * Special case: if the server bug is set that doesn't
7251 * allow rekeying, we give a different log message and
7252 * continue waiting. (If such a server _initiates_ a rekey,
7253 * we process it anyway!)
7255 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
7256 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
7258 /* Reset the counters, so that at least this message doesn't
7259 * hit the event log _too_ often. */
7260 ssh->outgoing_data_size = 0;
7261 ssh->incoming_data_size = 0;
7262 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
7264 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7267 goto wait_for_rekey; /* this is still utterly horrid */
7269 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
7272 goto begin_key_exchange;
7278 * Add data to an SSH-2 channel output buffer.
7280 static void ssh2_add_channel_data(struct ssh_channel *c, const char *buf,
7283 bufchain_add(&c->v.v2.outbuffer, buf, len);
7287 * Attempt to send data on an SSH-2 channel.
7289 static int ssh2_try_send(struct ssh_channel *c)
7292 struct Packet *pktout;
7295 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
7298 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
7299 if ((unsigned)len > c->v.v2.remwindow)
7300 len = c->v.v2.remwindow;
7301 if ((unsigned)len > c->v.v2.remmaxpkt)
7302 len = c->v.v2.remmaxpkt;
7303 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
7304 ssh2_pkt_adduint32(pktout, c->remoteid);
7305 ssh2_pkt_addstring_start(pktout);
7306 ssh2_pkt_addstring_data(pktout, data, len);
7307 ssh2_pkt_send(ssh, pktout);
7308 bufchain_consume(&c->v.v2.outbuffer, len);
7309 c->v.v2.remwindow -= len;
7313 * After having sent as much data as we can, return the amount
7316 ret = bufchain_size(&c->v.v2.outbuffer);
7319 * And if there's no data pending but we need to send an EOF, send
7322 if (!ret && c->pending_eof)
7323 ssh_channel_try_eof(c);
7328 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
7331 if (c->closes & CLOSES_SENT_EOF)
7332 return; /* don't send on channels we've EOFed */
7333 bufsize = ssh2_try_send(c);
7336 case CHAN_MAINSESSION:
7337 /* stdin need not receive an unthrottle
7338 * notification since it will be polled */
7341 x11_unthrottle(c->u.x11.xconn);
7344 /* agent sockets are request/response and need no
7345 * buffer management */
7348 pfd_unthrottle(c->u.pfd.pf);
7354 static int ssh_is_simple(Ssh ssh)
7357 * We use the 'simple' variant of the SSH protocol if we're asked
7358 * to, except not if we're also doing connection-sharing (either
7359 * tunnelling our packets over an upstream or expecting to be
7360 * tunnelled over ourselves), since then the assumption that we
7361 * have only one channel to worry about is not true after all.
7363 return (conf_get_int(ssh->conf, CONF_ssh_simple) &&
7364 !ssh->bare_connection && !ssh->connshare);
7368 * Set up most of a new ssh_channel for SSH-2.
7370 static void ssh2_channel_init(struct ssh_channel *c)
7373 c->localid = alloc_channel_id(ssh);
7375 c->pending_eof = FALSE;
7376 c->throttling_conn = FALSE;
7377 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
7378 ssh_is_simple(ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
7379 c->v.v2.chanreq_head = NULL;
7380 c->v.v2.throttle_state = UNTHROTTLED;
7381 bufchain_init(&c->v.v2.outbuffer);
7385 * Construct the common parts of a CHANNEL_OPEN.
7387 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c,
7390 struct Packet *pktout;
7392 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7393 ssh2_pkt_addstring(pktout, type);
7394 ssh2_pkt_adduint32(pktout, c->localid);
7395 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7396 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7401 * CHANNEL_FAILURE doesn't come with any indication of what message
7402 * caused it, so we have to keep track of the outstanding
7403 * CHANNEL_REQUESTs ourselves.
7405 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
7406 cchandler_fn_t handler, void *ctx)
7408 struct outstanding_channel_request *ocr =
7409 snew(struct outstanding_channel_request);
7411 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7412 ocr->handler = handler;
7415 if (!c->v.v2.chanreq_head)
7416 c->v.v2.chanreq_head = ocr;
7418 c->v.v2.chanreq_tail->next = ocr;
7419 c->v.v2.chanreq_tail = ocr;
7423 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
7424 * NULL then a reply will be requested and the handler will be called
7425 * when it arrives. The returned packet is ready to have any
7426 * request-specific data added and be sent. Note that if a handler is
7427 * provided, it's essential that the request actually be sent.
7429 * The handler will usually be passed the response packet in pktin. If
7430 * pktin is NULL, this means that no reply will ever be forthcoming
7431 * (e.g. because the entire connection is being destroyed, or because
7432 * the server initiated channel closure before we saw the response)
7433 * and the handler should free any storage it's holding.
7435 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c,
7437 cchandler_fn_t handler, void *ctx)
7439 struct Packet *pktout;
7441 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7442 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7443 ssh2_pkt_adduint32(pktout, c->remoteid);
7444 ssh2_pkt_addstring(pktout, type);
7445 ssh2_pkt_addbool(pktout, handler != NULL);
7446 if (handler != NULL)
7447 ssh2_queue_chanreq_handler(c, handler, ctx);
7452 * Potentially enlarge the window on an SSH-2 channel.
7454 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
7456 static void ssh2_set_window(struct ssh_channel *c, int newwin)
7461 * Never send WINDOW_ADJUST for a channel that the remote side has
7462 * already sent EOF on; there's no point, since it won't be
7463 * sending any more data anyway. Ditto if _we've_ already sent
7466 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
7470 * Also, never widen the window for an X11 channel when we're
7471 * still waiting to see its initial auth and may yet hand it off
7474 if (c->type == CHAN_X11 && c->u.x11.initial)
7478 * If the remote end has a habit of ignoring maxpkt, limit the
7479 * window so that it has no choice (assuming it doesn't ignore the
7482 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
7483 newwin = OUR_V2_MAXPKT;
7486 * Only send a WINDOW_ADJUST if there's significantly more window
7487 * available than the other end thinks there is. This saves us
7488 * sending a WINDOW_ADJUST for every character in a shell session.
7490 * "Significant" is arbitrarily defined as half the window size.
7492 if (newwin / 2 >= c->v.v2.locwindow) {
7493 struct Packet *pktout;
7497 * In order to keep track of how much window the client
7498 * actually has available, we'd like it to acknowledge each
7499 * WINDOW_ADJUST. We can't do that directly, so we accompany
7500 * it with a CHANNEL_REQUEST that has to be acknowledged.
7502 * This is only necessary if we're opening the window wide.
7503 * If we're not, then throughput is being constrained by
7504 * something other than the maximum window size anyway.
7506 if (newwin == c->v.v2.locmaxwin &&
7507 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
7508 up = snew(unsigned);
7509 *up = newwin - c->v.v2.locwindow;
7510 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
7511 ssh2_handle_winadj_response, up);
7512 ssh2_pkt_send(ssh, pktout);
7514 if (c->v.v2.throttle_state != UNTHROTTLED)
7515 c->v.v2.throttle_state = UNTHROTTLING;
7517 /* Pretend the WINDOW_ADJUST was acked immediately. */
7518 c->v.v2.remlocwin = newwin;
7519 c->v.v2.throttle_state = THROTTLED;
7521 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7522 ssh2_pkt_adduint32(pktout, c->remoteid);
7523 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
7524 ssh2_pkt_send(ssh, pktout);
7525 c->v.v2.locwindow = newwin;
7530 * Find the channel associated with a message. If there's no channel,
7531 * or it's not properly open, make a noise about it and return NULL.
7533 static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
7535 unsigned localid = ssh_pkt_getuint32(pktin);
7536 struct ssh_channel *c;
7538 c = find234(ssh->channels, &localid, ssh_channelfind);
7540 (c->type != CHAN_SHARING && c->halfopen &&
7541 pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
7542 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
7543 char *buf = dupprintf("Received %s for %s channel %u",
7544 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
7546 c ? "half-open" : "nonexistent", localid);
7547 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
7554 static void ssh2_handle_winadj_response(struct ssh_channel *c,
7555 struct Packet *pktin, void *ctx)
7557 unsigned *sizep = ctx;
7560 * Winadj responses should always be failures. However, at least
7561 * one server ("boks_sshd") is known to return SUCCESS for channel
7562 * requests it's never heard of, such as "winadj@putty". Raised
7563 * with foxt.com as bug 090916-090424, but for the sake of a quiet
7564 * life, we don't worry about what kind of response we got.
7567 c->v.v2.remlocwin += *sizep;
7570 * winadj messages are only sent when the window is fully open, so
7571 * if we get an ack of one, we know any pending unthrottle is
7574 if (c->v.v2.throttle_state == UNTHROTTLING)
7575 c->v.v2.throttle_state = UNTHROTTLED;
7578 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
7580 struct ssh_channel *c = ssh2_channel_msg(ssh, pktin);
7581 struct outstanding_channel_request *ocr;
7584 if (c->type == CHAN_SHARING) {
7585 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7586 pktin->body, pktin->length);
7589 ocr = c->v.v2.chanreq_head;
7591 ssh2_msg_unexpected(ssh, pktin);
7594 ocr->handler(c, pktin, ocr->ctx);
7595 c->v.v2.chanreq_head = ocr->next;
7598 * We may now initiate channel-closing procedures, if that
7599 * CHANNEL_REQUEST was the last thing outstanding before we send
7602 ssh2_channel_check_close(c);
7605 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
7607 struct ssh_channel *c;
7608 c = ssh2_channel_msg(ssh, pktin);
7611 if (c->type == CHAN_SHARING) {
7612 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7613 pktin->body, pktin->length);
7616 if (!(c->closes & CLOSES_SENT_EOF)) {
7617 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
7618 ssh2_try_send_and_unthrottle(ssh, c);
7622 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
7626 struct ssh_channel *c;
7627 c = ssh2_channel_msg(ssh, pktin);
7630 if (c->type == CHAN_SHARING) {
7631 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7632 pktin->body, pktin->length);
7635 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
7636 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
7637 return; /* extended but not stderr */
7638 ssh_pkt_getstring(pktin, &data, &length);
7641 c->v.v2.locwindow -= length;
7642 c->v.v2.remlocwin -= length;
7644 case CHAN_MAINSESSION:
7646 from_backend(ssh->frontend, pktin->type ==
7647 SSH2_MSG_CHANNEL_EXTENDED_DATA,
7651 bufsize = x11_send(c->u.x11.xconn, data, length);
7654 bufsize = pfd_send(c->u.pfd.pf, data, length);
7657 while (length > 0) {
7658 if (c->u.a.lensofar < 4) {
7659 unsigned int l = min(4 - c->u.a.lensofar,
7661 memcpy(c->u.a.msglen + c->u.a.lensofar,
7665 c->u.a.lensofar += l;
7667 if (c->u.a.lensofar == 4) {
7669 4 + GET_32BIT(c->u.a.msglen);
7670 c->u.a.message = snewn(c->u.a.totallen,
7672 memcpy(c->u.a.message, c->u.a.msglen, 4);
7674 if (c->u.a.lensofar >= 4 && length > 0) {
7676 min(c->u.a.totallen - c->u.a.lensofar,
7678 memcpy(c->u.a.message + c->u.a.lensofar,
7682 c->u.a.lensofar += l;
7684 if (c->u.a.lensofar == c->u.a.totallen) {
7687 c->u.a.outstanding_requests++;
7688 if (agent_query(c->u.a.message,
7691 ssh_agentf_callback, c))
7692 ssh_agentf_callback(c, reply, replylen);
7693 sfree(c->u.a.message);
7694 c->u.a.message = NULL;
7695 c->u.a.lensofar = 0;
7702 * If it looks like the remote end hit the end of its window,
7703 * and we didn't want it to do that, think about using a
7706 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
7707 c->v.v2.locmaxwin < 0x40000000)
7708 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
7710 * If we are not buffering too much data,
7711 * enlarge the window again at the remote side.
7712 * If we are buffering too much, we may still
7713 * need to adjust the window if the server's
7716 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
7717 c->v.v2.locmaxwin - bufsize : 0);
7719 * If we're either buffering way too much data, or if we're
7720 * buffering anything at all and we're in "simple" mode,
7721 * throttle the whole channel.
7723 if ((bufsize > c->v.v2.locmaxwin || (ssh_is_simple(ssh) && bufsize>0))
7724 && !c->throttling_conn) {
7725 c->throttling_conn = 1;
7726 ssh_throttle_conn(ssh, +1);
7731 static void ssh_check_termination(Ssh ssh)
7733 if (ssh->version == 2 &&
7734 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
7735 count234(ssh->channels) == 0 &&
7736 !(ssh->connshare && share_ndownstreams(ssh->connshare) > 0)) {
7738 * We used to send SSH_MSG_DISCONNECT here, because I'd
7739 * believed that _every_ conforming SSH-2 connection had to
7740 * end with a disconnect being sent by at least one side;
7741 * apparently I was wrong and it's perfectly OK to
7742 * unceremoniously slam the connection shut when you're done,
7743 * and indeed OpenSSH feels this is more polite than sending a
7744 * DISCONNECT. So now we don't.
7746 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
7750 void ssh_sharing_downstream_connected(Ssh ssh, unsigned id,
7751 const char *peerinfo)
7754 logeventf(ssh, "Connection sharing downstream #%u connected from %s",
7757 logeventf(ssh, "Connection sharing downstream #%u connected", id);
7760 void ssh_sharing_downstream_disconnected(Ssh ssh, unsigned id)
7762 logeventf(ssh, "Connection sharing downstream #%u disconnected", id);
7763 ssh_check_termination(ssh);
7766 void ssh_sharing_logf(Ssh ssh, unsigned id, const char *logfmt, ...)
7771 va_start(ap, logfmt);
7772 buf = dupvprintf(logfmt, ap);
7775 logeventf(ssh, "Connection sharing downstream #%u: %s", id, buf);
7777 logeventf(ssh, "Connection sharing: %s", buf);
7781 static void ssh_channel_destroy(struct ssh_channel *c)
7786 case CHAN_MAINSESSION:
7787 ssh->mainchan = NULL;
7788 update_specials_menu(ssh->frontend);
7791 if (c->u.x11.xconn != NULL)
7792 x11_close(c->u.x11.xconn);
7793 logevent("Forwarded X11 connection terminated");
7796 sfree(c->u.a.message);
7799 if (c->u.pfd.pf != NULL)
7800 pfd_close(c->u.pfd.pf);
7801 logevent("Forwarded port closed");
7805 del234(ssh->channels, c);
7806 if (ssh->version == 2) {
7807 bufchain_clear(&c->v.v2.outbuffer);
7808 assert(c->v.v2.chanreq_head == NULL);
7813 * If that was the last channel left open, we might need to
7816 ssh_check_termination(ssh);
7819 static void ssh2_channel_check_close(struct ssh_channel *c)
7822 struct Packet *pktout;
7826 * If we've sent out our own CHANNEL_OPEN but not yet seen
7827 * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
7828 * it's too early to be sending close messages of any kind.
7833 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
7834 c->type == CHAN_ZOMBIE) &&
7835 !c->v.v2.chanreq_head &&
7836 !(c->closes & CLOSES_SENT_CLOSE)) {
7838 * We have both sent and received EOF (or the channel is a
7839 * zombie), and we have no outstanding channel requests, which
7840 * means the channel is in final wind-up. But we haven't sent
7841 * CLOSE, so let's do so now.
7843 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
7844 ssh2_pkt_adduint32(pktout, c->remoteid);
7845 ssh2_pkt_send(ssh, pktout);
7846 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
7849 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
7850 assert(c->v.v2.chanreq_head == NULL);
7852 * We have both sent and received CLOSE, which means we're
7853 * completely done with the channel.
7855 ssh_channel_destroy(c);
7859 static void ssh2_channel_got_eof(struct ssh_channel *c)
7861 if (c->closes & CLOSES_RCVD_EOF)
7862 return; /* already seen EOF */
7863 c->closes |= CLOSES_RCVD_EOF;
7865 if (c->type == CHAN_X11) {
7866 x11_send_eof(c->u.x11.xconn);
7867 } else if (c->type == CHAN_AGENT) {
7868 if (c->u.a.outstanding_requests == 0) {
7869 /* Manufacture an outgoing EOF in response to the incoming one. */
7870 sshfwd_write_eof(c);
7872 } else if (c->type == CHAN_SOCKDATA) {
7873 pfd_send_eof(c->u.pfd.pf);
7874 } else if (c->type == CHAN_MAINSESSION) {
7877 if (!ssh->sent_console_eof &&
7878 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
7880 * Either from_backend_eof told us that the front end
7881 * wants us to close the outgoing side of the connection
7882 * as soon as we see EOF from the far end, or else we've
7883 * unilaterally decided to do that because we've allocated
7884 * a remote pty and hence EOF isn't a particularly
7885 * meaningful concept.
7887 sshfwd_write_eof(c);
7889 ssh->sent_console_eof = TRUE;
7892 ssh2_channel_check_close(c);
7895 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
7897 struct ssh_channel *c;
7899 c = ssh2_channel_msg(ssh, pktin);
7902 if (c->type == CHAN_SHARING) {
7903 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7904 pktin->body, pktin->length);
7907 ssh2_channel_got_eof(c);
7910 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
7912 struct ssh_channel *c;
7914 c = ssh2_channel_msg(ssh, pktin);
7917 if (c->type == CHAN_SHARING) {
7918 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7919 pktin->body, pktin->length);
7924 * When we receive CLOSE on a channel, we assume it comes with an
7925 * implied EOF if we haven't seen EOF yet.
7927 ssh2_channel_got_eof(c);
7929 if (!(ssh->remote_bugs & BUG_SENDS_LATE_REQUEST_REPLY)) {
7931 * It also means we stop expecting to see replies to any
7932 * outstanding channel requests, so clean those up too.
7933 * (ssh_chanreq_init will enforce by assertion that we don't
7934 * subsequently put anything back on this list.)
7936 while (c->v.v2.chanreq_head) {
7937 struct outstanding_channel_request *ocr = c->v.v2.chanreq_head;
7938 ocr->handler(c, NULL, ocr->ctx);
7939 c->v.v2.chanreq_head = ocr->next;
7945 * And we also send an outgoing EOF, if we haven't already, on the
7946 * assumption that CLOSE is a pretty forceful announcement that
7947 * the remote side is doing away with the entire channel. (If it
7948 * had wanted to send us EOF and continue receiving data from us,
7949 * it would have just sent CHANNEL_EOF.)
7951 if (!(c->closes & CLOSES_SENT_EOF)) {
7953 * Make sure we don't read any more from whatever our local
7954 * data source is for this channel.
7957 case CHAN_MAINSESSION:
7958 ssh->send_ok = 0; /* stop trying to read from stdin */
7961 x11_override_throttle(c->u.x11.xconn, 1);
7964 pfd_override_throttle(c->u.pfd.pf, 1);
7969 * Abandon any buffered data we still wanted to send to this
7970 * channel. Receiving a CHANNEL_CLOSE is an indication that
7971 * the server really wants to get on and _destroy_ this
7972 * channel, and it isn't going to send us any further
7973 * WINDOW_ADJUSTs to permit us to send pending stuff.
7975 bufchain_clear(&c->v.v2.outbuffer);
7978 * Send outgoing EOF.
7980 sshfwd_write_eof(c);
7984 * Now process the actual close.
7986 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
7987 c->closes |= CLOSES_RCVD_CLOSE;
7988 ssh2_channel_check_close(c);
7992 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
7994 struct ssh_channel *c;
7996 c = ssh2_channel_msg(ssh, pktin);
7999 if (c->type == CHAN_SHARING) {
8000 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8001 pktin->body, pktin->length);
8004 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
8005 c->remoteid = ssh_pkt_getuint32(pktin);
8006 c->halfopen = FALSE;
8007 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8008 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
8010 if (c->type == CHAN_SOCKDATA_DORMANT) {
8011 c->type = CHAN_SOCKDATA;
8013 pfd_confirm(c->u.pfd.pf);
8014 } else if (c->type == CHAN_ZOMBIE) {
8016 * This case can occur if a local socket error occurred
8017 * between us sending out CHANNEL_OPEN and receiving
8018 * OPEN_CONFIRMATION. In this case, all we can do is
8019 * immediately initiate close proceedings now that we know the
8020 * server's id to put in the close message.
8022 ssh2_channel_check_close(c);
8025 * We never expect to receive OPEN_CONFIRMATION for any
8026 * *other* channel type (since only local-to-remote port
8027 * forwardings cause us to send CHANNEL_OPEN after the main
8028 * channel is live - all other auxiliary channel types are
8029 * initiated from the server end). It's safe to enforce this
8030 * by assertion rather than by ssh_disconnect, because the
8031 * real point is that we never constructed a half-open channel
8032 * structure in the first place with any type other than the
8035 assert(!"Funny channel type in ssh2_msg_channel_open_confirmation");
8039 ssh_channel_try_eof(c); /* in case we had a pending EOF */
8042 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
8044 static const char *const reasons[] = {
8045 "<unknown reason code>",
8046 "Administratively prohibited",
8048 "Unknown channel type",
8049 "Resource shortage",
8051 unsigned reason_code;
8052 char *reason_string;
8054 struct ssh_channel *c;
8056 c = ssh2_channel_msg(ssh, pktin);
8059 if (c->type == CHAN_SHARING) {
8060 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8061 pktin->body, pktin->length);
8064 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
8066 if (c->type == CHAN_SOCKDATA_DORMANT) {
8067 reason_code = ssh_pkt_getuint32(pktin);
8068 if (reason_code >= lenof(reasons))
8069 reason_code = 0; /* ensure reasons[reason_code] in range */
8070 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
8071 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
8072 reasons[reason_code], reason_length, reason_string);
8074 pfd_close(c->u.pfd.pf);
8075 } else if (c->type == CHAN_ZOMBIE) {
8077 * This case can occur if a local socket error occurred
8078 * between us sending out CHANNEL_OPEN and receiving
8079 * OPEN_FAILURE. In this case, we need do nothing except allow
8080 * the code below to throw the half-open channel away.
8084 * We never expect to receive OPEN_FAILURE for any *other*
8085 * channel type (since only local-to-remote port forwardings
8086 * cause us to send CHANNEL_OPEN after the main channel is
8087 * live - all other auxiliary channel types are initiated from
8088 * the server end). It's safe to enforce this by assertion
8089 * rather than by ssh_disconnect, because the real point is
8090 * that we never constructed a half-open channel structure in
8091 * the first place with any type other than the above.
8093 assert(!"Funny channel type in ssh2_msg_channel_open_failure");
8096 del234(ssh->channels, c);
8100 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
8103 int typelen, want_reply;
8104 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
8105 struct ssh_channel *c;
8106 struct Packet *pktout;
8108 c = ssh2_channel_msg(ssh, pktin);
8111 if (c->type == CHAN_SHARING) {
8112 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8113 pktin->body, pktin->length);
8116 ssh_pkt_getstring(pktin, &type, &typelen);
8117 want_reply = ssh2_pkt_getbool(pktin);
8119 if (c->closes & CLOSES_SENT_CLOSE) {
8121 * We don't reply to channel requests after we've sent
8122 * CHANNEL_CLOSE for the channel, because our reply might
8123 * cross in the network with the other side's CHANNEL_CLOSE
8124 * and arrive after they have wound the channel up completely.
8130 * Having got the channel number, we now look at
8131 * the request type string to see if it's something
8134 if (c == ssh->mainchan) {
8136 * We recognise "exit-status" and "exit-signal" on
8137 * the primary channel.
8139 if (typelen == 11 &&
8140 !memcmp(type, "exit-status", 11)) {
8142 ssh->exitcode = ssh_pkt_getuint32(pktin);
8143 logeventf(ssh, "Server sent command exit status %d",
8145 reply = SSH2_MSG_CHANNEL_SUCCESS;
8147 } else if (typelen == 11 &&
8148 !memcmp(type, "exit-signal", 11)) {
8150 int is_plausible = TRUE, is_int = FALSE;
8151 char *fmt_sig = NULL, *fmt_msg = NULL;
8153 int msglen = 0, core = FALSE;
8154 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
8155 * provide an `int' for the signal, despite its
8156 * having been a `string' in the drafts of RFC 4254 since at
8157 * least 2001. (Fixed in session.c 1.147.) Try to
8158 * infer which we can safely parse it as. */
8160 unsigned char *p = pktin->body +
8162 long len = pktin->length - pktin->savedpos;
8163 unsigned long num = GET_32BIT(p); /* what is it? */
8164 /* If it's 0, it hardly matters; assume string */
8168 int maybe_int = FALSE, maybe_str = FALSE;
8169 #define CHECK_HYPOTHESIS(offset, result) \
8172 int q = toint(offset); \
8173 if (q >= 0 && q+4 <= len) { \
8174 q = toint(q + 4 + GET_32BIT(p+q)); \
8175 if (q >= 0 && q+4 <= len && \
8176 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
8181 CHECK_HYPOTHESIS(4+1, maybe_int);
8182 CHECK_HYPOTHESIS(4+num+1, maybe_str);
8183 #undef CHECK_HYPOTHESIS
8184 if (maybe_int && !maybe_str)
8186 else if (!maybe_int && maybe_str)
8189 /* Crikey. Either or neither. Panic. */
8190 is_plausible = FALSE;
8193 ssh->exitcode = 128; /* means `unknown signal' */
8196 /* Old non-standard OpenSSH. */
8197 int signum = ssh_pkt_getuint32(pktin);
8198 fmt_sig = dupprintf(" %d", signum);
8199 ssh->exitcode = 128 + signum;
8201 /* As per RFC 4254. */
8204 ssh_pkt_getstring(pktin, &sig, &siglen);
8205 /* Signal name isn't supposed to be blank, but
8206 * let's cope gracefully if it is. */
8208 fmt_sig = dupprintf(" \"%.*s\"",
8213 * Really hideous method of translating the
8214 * signal description back into a locally
8215 * meaningful number.
8220 #define TRANSLATE_SIGNAL(s) \
8221 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
8222 ssh->exitcode = 128 + SIG ## s
8224 TRANSLATE_SIGNAL(ABRT);
8227 TRANSLATE_SIGNAL(ALRM);
8230 TRANSLATE_SIGNAL(FPE);
8233 TRANSLATE_SIGNAL(HUP);
8236 TRANSLATE_SIGNAL(ILL);
8239 TRANSLATE_SIGNAL(INT);
8242 TRANSLATE_SIGNAL(KILL);
8245 TRANSLATE_SIGNAL(PIPE);
8248 TRANSLATE_SIGNAL(QUIT);
8251 TRANSLATE_SIGNAL(SEGV);
8254 TRANSLATE_SIGNAL(TERM);
8257 TRANSLATE_SIGNAL(USR1);
8260 TRANSLATE_SIGNAL(USR2);
8262 #undef TRANSLATE_SIGNAL
8264 ssh->exitcode = 128;
8266 core = ssh2_pkt_getbool(pktin);
8267 ssh_pkt_getstring(pktin, &msg, &msglen);
8269 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
8271 /* ignore lang tag */
8272 } /* else don't attempt to parse */
8273 logeventf(ssh, "Server exited on signal%s%s%s",
8274 fmt_sig ? fmt_sig : "",
8275 core ? " (core dumped)" : "",
8276 fmt_msg ? fmt_msg : "");
8279 reply = SSH2_MSG_CHANNEL_SUCCESS;
8284 * This is a channel request we don't know
8285 * about, so we now either ignore the request
8286 * or respond with CHANNEL_FAILURE, depending
8289 reply = SSH2_MSG_CHANNEL_FAILURE;
8292 pktout = ssh2_pkt_init(reply);
8293 ssh2_pkt_adduint32(pktout, c->remoteid);
8294 ssh2_pkt_send(ssh, pktout);
8298 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
8301 int typelen, want_reply;
8302 struct Packet *pktout;
8304 ssh_pkt_getstring(pktin, &type, &typelen);
8305 want_reply = ssh2_pkt_getbool(pktin);
8308 * We currently don't support any global requests
8309 * at all, so we either ignore the request or
8310 * respond with REQUEST_FAILURE, depending on
8314 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
8315 ssh2_pkt_send(ssh, pktout);
8319 struct X11FakeAuth *ssh_sharing_add_x11_display(Ssh ssh, int authtype,
8323 struct X11FakeAuth *auth;
8326 * Make up a new set of fake X11 auth data, and add it to the tree
8327 * of currently valid ones with an indication of the sharing
8328 * context that it's relevant to.
8330 auth = x11_invent_fake_auth(ssh->x11authtree, authtype);
8331 auth->share_cs = share_cs;
8332 auth->share_chan = share_chan;
8337 void ssh_sharing_remove_x11_display(Ssh ssh, struct X11FakeAuth *auth)
8339 del234(ssh->x11authtree, auth);
8340 x11_free_fake_auth(auth);
8343 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
8350 const char *error = NULL;
8351 struct ssh_channel *c;
8352 unsigned remid, winsize, pktsize;
8353 unsigned our_winsize_override = 0;
8354 struct Packet *pktout;
8356 ssh_pkt_getstring(pktin, &type, &typelen);
8357 c = snew(struct ssh_channel);
8360 remid = ssh_pkt_getuint32(pktin);
8361 winsize = ssh_pkt_getuint32(pktin);
8362 pktsize = ssh_pkt_getuint32(pktin);
8364 if (typelen == 3 && !memcmp(type, "x11", 3)) {
8367 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8368 addrstr = snewn(peeraddrlen+1, char);
8369 memcpy(addrstr, peeraddr, peeraddrlen);
8370 addrstr[peeraddrlen] = '\0';
8371 peerport = ssh_pkt_getuint32(pktin);
8373 logeventf(ssh, "Received X11 connect request from %s:%d",
8376 if (!ssh->X11_fwd_enabled && !ssh->connshare)
8377 error = "X11 forwarding is not enabled";
8379 c->u.x11.xconn = x11_init(ssh->x11authtree, c,
8382 c->u.x11.initial = TRUE;
8385 * If we are a connection-sharing upstream, then we should
8386 * initially present a very small window, adequate to take
8387 * the X11 initial authorisation packet but not much more.
8388 * Downstream will then present us a larger window (by
8389 * fiat of the connection-sharing protocol) and we can
8390 * guarantee to send a positive-valued WINDOW_ADJUST.
8393 our_winsize_override = 128;
8395 logevent("Opened X11 forward channel");
8399 } else if (typelen == 15 &&
8400 !memcmp(type, "forwarded-tcpip", 15)) {
8401 struct ssh_rportfwd pf, *realpf;
8404 ssh_pkt_getstring(pktin, &shost, &shostlen);/* skip address */
8405 pf.shost = dupprintf("%.*s", shostlen, shost);
8406 pf.sport = ssh_pkt_getuint32(pktin);
8407 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8408 peerport = ssh_pkt_getuint32(pktin);
8409 realpf = find234(ssh->rportfwds, &pf, NULL);
8410 logeventf(ssh, "Received remote port %s:%d open request "
8411 "from %s:%d", pf.shost, pf.sport, peeraddr, peerport);
8414 if (realpf == NULL) {
8415 error = "Remote port is not recognised";
8419 if (realpf->share_ctx) {
8421 * This port forwarding is on behalf of a
8422 * connection-sharing downstream, so abandon our own
8423 * channel-open procedure and just pass the message on
8426 share_got_pkt_from_server(realpf->share_ctx, pktin->type,
8427 pktin->body, pktin->length);
8432 err = pfd_connect(&c->u.pfd.pf, realpf->dhost, realpf->dport,
8433 c, ssh->conf, realpf->pfrec->addressfamily);
8434 logeventf(ssh, "Attempting to forward remote port to "
8435 "%s:%d", realpf->dhost, realpf->dport);
8437 logeventf(ssh, "Port open failed: %s", err);
8439 error = "Port open failed";
8441 logevent("Forwarded port opened successfully");
8442 c->type = CHAN_SOCKDATA;
8445 } else if (typelen == 22 &&
8446 !memcmp(type, "auth-agent@openssh.com", 22)) {
8447 if (!ssh->agentfwd_enabled)
8448 error = "Agent forwarding is not enabled";
8450 c->type = CHAN_AGENT; /* identify channel type */
8451 c->u.a.lensofar = 0;
8452 c->u.a.message = NULL;
8453 c->u.a.outstanding_requests = 0;
8456 error = "Unsupported channel type requested";
8459 c->remoteid = remid;
8460 c->halfopen = FALSE;
8462 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
8463 ssh2_pkt_adduint32(pktout, c->remoteid);
8464 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
8465 ssh2_pkt_addstring(pktout, error);
8466 ssh2_pkt_addstring(pktout, "en"); /* language tag */
8467 ssh2_pkt_send(ssh, pktout);
8468 logeventf(ssh, "Rejected channel open: %s", error);
8471 ssh2_channel_init(c);
8472 c->v.v2.remwindow = winsize;
8473 c->v.v2.remmaxpkt = pktsize;
8474 if (our_winsize_override) {
8475 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
8476 our_winsize_override;
8478 add234(ssh->channels, c);
8479 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
8480 ssh2_pkt_adduint32(pktout, c->remoteid);
8481 ssh2_pkt_adduint32(pktout, c->localid);
8482 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
8483 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8484 ssh2_pkt_send(ssh, pktout);
8488 void sshfwd_x11_sharing_handover(struct ssh_channel *c,
8489 void *share_cs, void *share_chan,
8490 const char *peer_addr, int peer_port,
8491 int endian, int protomajor, int protominor,
8492 const void *initial_data, int initial_len)
8495 * This function is called when we've just discovered that an X
8496 * forwarding channel on which we'd been handling the initial auth
8497 * ourselves turns out to be destined for a connection-sharing
8498 * downstream. So we turn the channel into a CHAN_SHARING, meaning
8499 * that we completely stop tracking windows and buffering data and
8500 * just pass more or less unmodified SSH messages back and forth.
8502 c->type = CHAN_SHARING;
8503 c->u.sharing.ctx = share_cs;
8504 share_setup_x11_channel(share_cs, share_chan,
8505 c->localid, c->remoteid, c->v.v2.remwindow,
8506 c->v.v2.remmaxpkt, c->v.v2.locwindow,
8507 peer_addr, peer_port, endian,
8508 protomajor, protominor,
8509 initial_data, initial_len);
8512 void sshfwd_x11_is_local(struct ssh_channel *c)
8515 * This function is called when we've just discovered that an X
8516 * forwarding channel is _not_ destined for a connection-sharing
8517 * downstream but we're going to handle it ourselves. We stop
8518 * presenting a cautiously small window and go into ordinary data
8521 c->u.x11.initial = FALSE;
8522 ssh2_set_window(c, ssh_is_simple(c->ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE);
8526 * Buffer banner messages for later display at some convenient point,
8527 * if we're going to display them.
8529 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
8531 /* Arbitrary limit to prevent unbounded inflation of buffer */
8532 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
8533 bufchain_size(&ssh->banner) <= 131072) {
8534 char *banner = NULL;
8536 ssh_pkt_getstring(pktin, &banner, &size);
8538 bufchain_add(&ssh->banner, banner, size);
8542 /* Helper function to deal with sending tty modes for "pty-req" */
8543 static void ssh2_send_ttymode(void *data, char *mode, char *val)
8545 struct Packet *pktout = (struct Packet *)data;
8547 unsigned int arg = 0;
8548 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
8549 if (i == lenof(ssh_ttymodes)) return;
8550 switch (ssh_ttymodes[i].type) {
8552 arg = ssh_tty_parse_specchar(val);
8555 arg = ssh_tty_parse_boolean(val);
8558 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
8559 ssh2_pkt_adduint32(pktout, arg);
8562 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
8565 struct ssh2_setup_x11_state {
8569 struct Packet *pktout;
8570 crStateP(ssh2_setup_x11_state, ctx);
8574 logevent("Requesting X11 forwarding");
8575 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
8577 ssh2_pkt_addbool(pktout, 0); /* many connections */
8578 ssh2_pkt_addstring(pktout, ssh->x11auth->protoname);
8579 ssh2_pkt_addstring(pktout, ssh->x11auth->datastring);
8580 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
8581 ssh2_pkt_send(ssh, pktout);
8583 /* Wait to be called back with either a response packet, or NULL
8584 * meaning clean up and free our data */
8588 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8589 logevent("X11 forwarding enabled");
8590 ssh->X11_fwd_enabled = TRUE;
8592 logevent("X11 forwarding refused");
8598 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
8601 struct ssh2_setup_agent_state {
8605 struct Packet *pktout;
8606 crStateP(ssh2_setup_agent_state, ctx);
8610 logevent("Requesting OpenSSH-style agent forwarding");
8611 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
8612 ssh2_setup_agent, s);
8613 ssh2_pkt_send(ssh, pktout);
8615 /* Wait to be called back with either a response packet, or NULL
8616 * meaning clean up and free our data */
8620 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8621 logevent("Agent forwarding enabled");
8622 ssh->agentfwd_enabled = TRUE;
8624 logevent("Agent forwarding refused");
8630 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
8633 struct ssh2_setup_pty_state {
8637 struct Packet *pktout;
8638 crStateP(ssh2_setup_pty_state, ctx);
8642 /* Unpick the terminal-speed string. */
8643 /* XXX perhaps we should allow no speeds to be sent. */
8644 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
8645 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
8646 /* Build the pty request. */
8647 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
8649 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
8650 ssh2_pkt_adduint32(pktout, ssh->term_width);
8651 ssh2_pkt_adduint32(pktout, ssh->term_height);
8652 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
8653 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
8654 ssh2_pkt_addstring_start(pktout);
8655 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
8656 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
8657 ssh2_pkt_adduint32(pktout, ssh->ispeed);
8658 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
8659 ssh2_pkt_adduint32(pktout, ssh->ospeed);
8660 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
8661 ssh2_pkt_send(ssh, pktout);
8662 ssh->state = SSH_STATE_INTERMED;
8664 /* Wait to be called back with either a response packet, or NULL
8665 * meaning clean up and free our data */
8669 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8670 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
8671 ssh->ospeed, ssh->ispeed);
8672 ssh->got_pty = TRUE;
8674 c_write_str(ssh, "Server refused to allocate pty\r\n");
8675 ssh->editing = ssh->echoing = 1;
8682 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
8685 struct ssh2_setup_env_state {
8687 int num_env, env_left, env_ok;
8690 struct Packet *pktout;
8691 crStateP(ssh2_setup_env_state, ctx);
8696 * Send environment variables.
8698 * Simplest thing here is to send all the requests at once, and
8699 * then wait for a whole bunch of successes or failures.
8705 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
8707 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
8708 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
8709 ssh2_pkt_addstring(pktout, key);
8710 ssh2_pkt_addstring(pktout, val);
8711 ssh2_pkt_send(ssh, pktout);
8716 logeventf(ssh, "Sent %d environment variables", s->num_env);
8721 s->env_left = s->num_env;
8723 while (s->env_left > 0) {
8724 /* Wait to be called back with either a response packet,
8725 * or NULL meaning clean up and free our data */
8727 if (!pktin) goto out;
8728 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
8733 if (s->env_ok == s->num_env) {
8734 logevent("All environment variables successfully set");
8735 } else if (s->env_ok == 0) {
8736 logevent("All environment variables refused");
8737 c_write_str(ssh, "Server refused to set environment variables\r\n");
8739 logeventf(ssh, "%d environment variables refused",
8740 s->num_env - s->env_ok);
8741 c_write_str(ssh, "Server refused to set all environment variables\r\n");
8749 * Handle the SSH-2 userauth and connection layers.
8751 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
8753 do_ssh2_authconn(ssh, NULL, 0, pktin);
8756 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
8760 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
8763 static void do_ssh2_authconn(Ssh ssh, const unsigned char *in, int inlen,
8764 struct Packet *pktin)
8766 struct do_ssh2_authconn_state {
8770 AUTH_TYPE_PUBLICKEY,
8771 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
8772 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
8774 AUTH_TYPE_GSSAPI, /* always QUIET */
8775 AUTH_TYPE_KEYBOARD_INTERACTIVE,
8776 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
8778 int done_service_req;
8779 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
8780 int tried_pubkey_config, done_agent;
8785 int kbd_inter_refused;
8786 int we_are_in, userauth_success;
8787 prompts_t *cur_prompt;
8792 void *publickey_blob;
8793 int publickey_bloblen;
8794 int privatekey_available, privatekey_encrypted;
8795 char *publickey_algorithm;
8796 char *publickey_comment;
8797 unsigned char agent_request[5], *agent_response, *agentp;
8798 int agent_responselen;
8799 unsigned char *pkblob_in_agent;
8801 char *pkblob, *alg, *commentp;
8802 int pklen, alglen, commentlen;
8803 int siglen, retlen, len;
8804 char *q, *agentreq, *ret;
8806 struct Packet *pktout;
8809 struct ssh_gss_library *gsslib;
8810 Ssh_gss_ctx gss_ctx;
8811 Ssh_gss_buf gss_buf;
8812 Ssh_gss_buf gss_rcvtok, gss_sndtok;
8813 Ssh_gss_name gss_srv_name;
8814 Ssh_gss_stat gss_stat;
8817 crState(do_ssh2_authconn_state);
8821 /* Register as a handler for all the messages this coroutine handles. */
8822 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
8823 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
8824 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
8825 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
8826 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
8827 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
8828 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
8829 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
8830 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
8831 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
8832 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
8833 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
8834 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
8835 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
8836 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
8837 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
8838 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
8839 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
8840 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
8841 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
8843 s->done_service_req = FALSE;
8844 s->we_are_in = s->userauth_success = FALSE;
8845 s->agent_response = NULL;
8847 s->tried_gssapi = FALSE;
8850 if (!ssh->bare_connection) {
8851 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
8853 * Request userauth protocol, and await a response to it.
8855 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8856 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
8857 ssh2_pkt_send(ssh, s->pktout);
8858 crWaitUntilV(pktin);
8859 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
8860 s->done_service_req = TRUE;
8862 if (!s->done_service_req) {
8864 * Request connection protocol directly, without authentication.
8866 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8867 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8868 ssh2_pkt_send(ssh, s->pktout);
8869 crWaitUntilV(pktin);
8870 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
8871 s->we_are_in = TRUE; /* no auth required */
8873 bombout(("Server refused service request"));
8878 s->we_are_in = TRUE;
8881 /* Arrange to be able to deal with any BANNERs that come in.
8882 * (We do this now as packets may come in during the next bit.) */
8883 bufchain_init(&ssh->banner);
8884 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
8885 ssh2_msg_userauth_banner;
8888 * Misc one-time setup for authentication.
8890 s->publickey_blob = NULL;
8891 if (!s->we_are_in) {
8894 * Load the public half of any configured public key file
8897 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
8898 if (!filename_is_null(s->keyfile)) {
8900 logeventf(ssh, "Reading key file \"%.150s\"",
8901 filename_to_str(s->keyfile));
8902 keytype = key_type(s->keyfile);
8903 if (keytype == SSH_KEYTYPE_SSH2 ||
8904 keytype == SSH_KEYTYPE_SSH2_PUBLIC_RFC4716 ||
8905 keytype == SSH_KEYTYPE_SSH2_PUBLIC_OPENSSH) {
8908 ssh2_userkey_loadpub(s->keyfile,
8909 &s->publickey_algorithm,
8910 &s->publickey_bloblen,
8911 &s->publickey_comment, &error);
8912 if (s->publickey_blob) {
8913 s->privatekey_available = (keytype == SSH_KEYTYPE_SSH2);
8914 if (!s->privatekey_available)
8915 logeventf(ssh, "Key file contains public key only");
8916 s->privatekey_encrypted =
8917 ssh2_userkey_encrypted(s->keyfile, NULL);
8920 logeventf(ssh, "Unable to load key (%s)",
8922 msgbuf = dupprintf("Unable to load key file "
8923 "\"%.150s\" (%s)\r\n",
8924 filename_to_str(s->keyfile),
8926 c_write_str(ssh, msgbuf);
8931 logeventf(ssh, "Unable to use this key file (%s)",
8932 key_type_to_str(keytype));
8933 msgbuf = dupprintf("Unable to use key file \"%.150s\""
8935 filename_to_str(s->keyfile),
8936 key_type_to_str(keytype));
8937 c_write_str(ssh, msgbuf);
8939 s->publickey_blob = NULL;
8944 * Find out about any keys Pageant has (but if there's a
8945 * public key configured, filter out all others).
8948 s->agent_response = NULL;
8949 s->pkblob_in_agent = NULL;
8950 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
8954 logevent("Pageant is running. Requesting keys.");
8956 /* Request the keys held by the agent. */
8957 PUT_32BIT(s->agent_request, 1);
8958 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
8959 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
8960 ssh_agent_callback, ssh)) {
8964 bombout(("Unexpected data from server while"
8965 " waiting for agent response"));
8968 } while (pktin || inlen > 0);
8969 r = ssh->agent_response;
8970 s->agent_responselen = ssh->agent_response_len;
8972 s->agent_response = (unsigned char *) r;
8973 if (s->agent_response && s->agent_responselen >= 5 &&
8974 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
8977 p = s->agent_response + 5;
8978 s->nkeys = toint(GET_32BIT(p));
8981 * Vet the Pageant response to ensure that the key
8982 * count and blob lengths make sense.
8985 logeventf(ssh, "Pageant response contained a negative"
8986 " key count %d", s->nkeys);
8988 goto done_agent_query;
8990 unsigned char *q = p + 4;
8991 int lenleft = s->agent_responselen - 5 - 4;
8993 for (keyi = 0; keyi < s->nkeys; keyi++) {
8994 int bloblen, commentlen;
8996 logeventf(ssh, "Pageant response was truncated");
8998 goto done_agent_query;
9000 bloblen = toint(GET_32BIT(q));
9001 if (bloblen < 0 || bloblen > lenleft) {
9002 logeventf(ssh, "Pageant response was truncated");
9004 goto done_agent_query;
9006 lenleft -= 4 + bloblen;
9008 commentlen = toint(GET_32BIT(q));
9009 if (commentlen < 0 || commentlen > lenleft) {
9010 logeventf(ssh, "Pageant response was truncated");
9012 goto done_agent_query;
9014 lenleft -= 4 + commentlen;
9015 q += 4 + commentlen;
9020 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
9021 if (s->publickey_blob) {
9022 /* See if configured key is in agent. */
9023 for (keyi = 0; keyi < s->nkeys; keyi++) {
9024 s->pklen = toint(GET_32BIT(p));
9025 if (s->pklen == s->publickey_bloblen &&
9026 !memcmp(p+4, s->publickey_blob,
9027 s->publickey_bloblen)) {
9028 logeventf(ssh, "Pageant key #%d matches "
9029 "configured key file", keyi);
9031 s->pkblob_in_agent = p;
9035 p += toint(GET_32BIT(p)) + 4; /* comment */
9037 if (!s->pkblob_in_agent) {
9038 logevent("Configured key file not in Pageant");
9043 logevent("Failed to get reply from Pageant");
9051 * We repeat this whole loop, including the username prompt,
9052 * until we manage a successful authentication. If the user
9053 * types the wrong _password_, they can be sent back to the
9054 * beginning to try another username, if this is configured on.
9055 * (If they specify a username in the config, they are never
9056 * asked, even if they do give a wrong password.)
9058 * I think this best serves the needs of
9060 * - the people who have no configuration, no keys, and just
9061 * want to try repeated (username,password) pairs until they
9062 * type both correctly
9064 * - people who have keys and configuration but occasionally
9065 * need to fall back to passwords
9067 * - people with a key held in Pageant, who might not have
9068 * logged in to a particular machine before; so they want to
9069 * type a username, and then _either_ their key will be
9070 * accepted, _or_ they will type a password. If they mistype
9071 * the username they will want to be able to get back and
9074 s->got_username = FALSE;
9075 while (!s->we_are_in) {
9079 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
9081 * We got a username last time round this loop, and
9082 * with change_username turned off we don't try to get
9085 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
9086 int ret; /* need not be kept over crReturn */
9087 s->cur_prompt = new_prompts(ssh->frontend);
9088 s->cur_prompt->to_server = TRUE;
9089 s->cur_prompt->name = dupstr("SSH login name");
9090 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
9091 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9094 crWaitUntilV(!pktin);
9095 ret = get_userpass_input(s->cur_prompt, in, inlen);
9100 * get_userpass_input() failed to get a username.
9103 free_prompts(s->cur_prompt);
9104 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
9107 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
9108 free_prompts(s->cur_prompt);
9111 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
9112 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
9113 c_write_str(ssh, stuff);
9117 s->got_username = TRUE;
9120 * Send an authentication request using method "none": (a)
9121 * just in case it succeeds, and (b) so that we know what
9122 * authentication methods we can usefully try next.
9124 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9126 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9127 ssh2_pkt_addstring(s->pktout, ssh->username);
9128 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
9129 ssh2_pkt_addstring(s->pktout, "none"); /* method */
9130 ssh2_pkt_send(ssh, s->pktout);
9131 s->type = AUTH_TYPE_NONE;
9133 s->we_are_in = FALSE;
9135 s->tried_pubkey_config = FALSE;
9136 s->kbd_inter_refused = FALSE;
9138 /* Reset agent request state. */
9139 s->done_agent = FALSE;
9140 if (s->agent_response) {
9141 if (s->pkblob_in_agent) {
9142 s->agentp = s->pkblob_in_agent;
9144 s->agentp = s->agent_response + 5 + 4;
9150 char *methods = NULL;
9154 * Wait for the result of the last authentication request.
9157 crWaitUntilV(pktin);
9159 * Now is a convenient point to spew any banner material
9160 * that we've accumulated. (This should ensure that when
9161 * we exit the auth loop, we haven't any left to deal
9165 int size = bufchain_size(&ssh->banner);
9167 * Don't show the banner if we're operating in
9168 * non-verbose non-interactive mode. (It's probably
9169 * a script, which means nobody will read the
9170 * banner _anyway_, and moreover the printing of
9171 * the banner will screw up processing on the
9172 * output of (say) plink.)
9174 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
9175 char *banner = snewn(size, char);
9176 bufchain_fetch(&ssh->banner, banner, size);
9177 c_write_untrusted(ssh, banner, size);
9180 bufchain_clear(&ssh->banner);
9182 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
9183 logevent("Access granted");
9184 s->we_are_in = s->userauth_success = TRUE;
9188 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
9189 bombout(("Strange packet received during authentication: "
9190 "type %d", pktin->type));
9197 * OK, we're now sitting on a USERAUTH_FAILURE message, so
9198 * we can look at the string in it and know what we can
9199 * helpfully try next.
9201 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
9202 ssh_pkt_getstring(pktin, &methods, &methlen);
9203 if (!ssh2_pkt_getbool(pktin)) {
9205 * We have received an unequivocal Access
9206 * Denied. This can translate to a variety of
9207 * messages, or no message at all.
9209 * For forms of authentication which are attempted
9210 * implicitly, by which I mean without printing
9211 * anything in the window indicating that we're
9212 * trying them, we should never print 'Access
9215 * If we do print a message saying that we're
9216 * attempting some kind of authentication, it's OK
9217 * to print a followup message saying it failed -
9218 * but the message may sometimes be more specific
9219 * than simply 'Access denied'.
9221 * Additionally, if we'd just tried password
9222 * authentication, we should break out of this
9223 * whole loop so as to go back to the username
9224 * prompt (iff we're configured to allow
9225 * username change attempts).
9227 if (s->type == AUTH_TYPE_NONE) {
9229 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
9230 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
9231 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
9232 c_write_str(ssh, "Server refused our key\r\n");
9233 logevent("Server refused our key");
9234 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
9235 /* This _shouldn't_ happen except by a
9236 * protocol bug causing client and server to
9237 * disagree on what is a correct signature. */
9238 c_write_str(ssh, "Server refused public-key signature"
9239 " despite accepting key!\r\n");
9240 logevent("Server refused public-key signature"
9241 " despite accepting key!");
9242 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
9243 /* quiet, so no c_write */
9244 logevent("Server refused keyboard-interactive authentication");
9245 } else if (s->type==AUTH_TYPE_GSSAPI) {
9246 /* always quiet, so no c_write */
9247 /* also, the code down in the GSSAPI block has
9248 * already logged this in the Event Log */
9249 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
9250 logevent("Keyboard-interactive authentication failed");
9251 c_write_str(ssh, "Access denied\r\n");
9253 assert(s->type == AUTH_TYPE_PASSWORD);
9254 logevent("Password authentication failed");
9255 c_write_str(ssh, "Access denied\r\n");
9257 if (conf_get_int(ssh->conf, CONF_change_username)) {
9258 /* XXX perhaps we should allow
9259 * keyboard-interactive to do this too? */
9260 s->we_are_in = FALSE;
9265 c_write_str(ssh, "Further authentication required\r\n");
9266 logevent("Further authentication required");
9270 in_commasep_string("publickey", methods, methlen);
9272 in_commasep_string("password", methods, methlen);
9273 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
9274 in_commasep_string("keyboard-interactive", methods, methlen);
9277 ssh->gsslibs = ssh_gss_setup(ssh->conf);
9278 s->can_gssapi = conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
9279 in_commasep_string("gssapi-with-mic", methods, methlen) &&
9280 ssh->gsslibs->nlibraries > 0;
9284 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9286 if (s->can_pubkey && !s->done_agent && s->nkeys) {
9289 * Attempt public-key authentication using a key from Pageant.
9292 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9294 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
9296 /* Unpack key from agent response */
9297 s->pklen = toint(GET_32BIT(s->agentp));
9299 s->pkblob = (char *)s->agentp;
9300 s->agentp += s->pklen;
9301 s->alglen = toint(GET_32BIT(s->pkblob));
9302 s->alg = s->pkblob + 4;
9303 s->commentlen = toint(GET_32BIT(s->agentp));
9305 s->commentp = (char *)s->agentp;
9306 s->agentp += s->commentlen;
9307 /* s->agentp now points at next key, if any */
9309 /* See if server will accept it */
9310 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9311 ssh2_pkt_addstring(s->pktout, ssh->username);
9312 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9313 /* service requested */
9314 ssh2_pkt_addstring(s->pktout, "publickey");
9316 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
9317 ssh2_pkt_addstring_start(s->pktout);
9318 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9319 ssh2_pkt_addstring_start(s->pktout);
9320 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9321 ssh2_pkt_send(ssh, s->pktout);
9322 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
9324 crWaitUntilV(pktin);
9325 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9327 /* Offer of key refused. */
9334 if (flags & FLAG_VERBOSE) {
9335 c_write_str(ssh, "Authenticating with "
9337 c_write(ssh, s->commentp, s->commentlen);
9338 c_write_str(ssh, "\" from agent\r\n");
9342 * Server is willing to accept the key.
9343 * Construct a SIGN_REQUEST.
9345 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9346 ssh2_pkt_addstring(s->pktout, ssh->username);
9347 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9348 /* service requested */
9349 ssh2_pkt_addstring(s->pktout, "publickey");
9351 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
9352 ssh2_pkt_addstring_start(s->pktout);
9353 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9354 ssh2_pkt_addstring_start(s->pktout);
9355 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9357 /* Ask agent for signature. */
9358 s->siglen = s->pktout->length - 5 + 4 +
9359 ssh->v2_session_id_len;
9360 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9362 s->len = 1; /* message type */
9363 s->len += 4 + s->pklen; /* key blob */
9364 s->len += 4 + s->siglen; /* data to sign */
9365 s->len += 4; /* flags */
9366 s->agentreq = snewn(4 + s->len, char);
9367 PUT_32BIT(s->agentreq, s->len);
9368 s->q = s->agentreq + 4;
9369 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
9370 PUT_32BIT(s->q, s->pklen);
9372 memcpy(s->q, s->pkblob, s->pklen);
9374 PUT_32BIT(s->q, s->siglen);
9376 /* Now the data to be signed... */
9377 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9378 PUT_32BIT(s->q, ssh->v2_session_id_len);
9381 memcpy(s->q, ssh->v2_session_id,
9382 ssh->v2_session_id_len);
9383 s->q += ssh->v2_session_id_len;
9384 memcpy(s->q, s->pktout->data + 5,
9385 s->pktout->length - 5);
9386 s->q += s->pktout->length - 5;
9387 /* And finally the (zero) flags word. */
9389 if (!agent_query(s->agentreq, s->len + 4,
9391 ssh_agent_callback, ssh)) {
9395 bombout(("Unexpected data from server"
9396 " while waiting for agent"
9400 } while (pktin || inlen > 0);
9401 vret = ssh->agent_response;
9402 s->retlen = ssh->agent_response_len;
9407 if (s->retlen >= 9 &&
9408 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
9409 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
9410 logevent("Sending Pageant's response");
9411 ssh2_add_sigblob(ssh, s->pktout,
9412 s->pkblob, s->pklen,
9414 GET_32BIT(s->ret + 5));
9415 ssh2_pkt_send(ssh, s->pktout);
9416 s->type = AUTH_TYPE_PUBLICKEY;
9418 /* FIXME: less drastic response */
9419 bombout(("Pageant failed to answer challenge"));
9425 /* Do we have any keys left to try? */
9426 if (s->pkblob_in_agent) {
9427 s->done_agent = TRUE;
9428 s->tried_pubkey_config = TRUE;
9431 if (s->keyi >= s->nkeys)
9432 s->done_agent = TRUE;
9435 } else if (s->can_pubkey && s->publickey_blob &&
9436 s->privatekey_available && !s->tried_pubkey_config) {
9438 struct ssh2_userkey *key; /* not live over crReturn */
9439 char *passphrase; /* not live over crReturn */
9441 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9443 s->tried_pubkey_config = TRUE;
9446 * Try the public key supplied in the configuration.
9448 * First, offer the public blob to see if the server is
9449 * willing to accept it.
9451 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9452 ssh2_pkt_addstring(s->pktout, ssh->username);
9453 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9454 /* service requested */
9455 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
9456 ssh2_pkt_addbool(s->pktout, FALSE);
9457 /* no signature included */
9458 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
9459 ssh2_pkt_addstring_start(s->pktout);
9460 ssh2_pkt_addstring_data(s->pktout,
9461 (char *)s->publickey_blob,
9462 s->publickey_bloblen);
9463 ssh2_pkt_send(ssh, s->pktout);
9464 logevent("Offered public key");
9466 crWaitUntilV(pktin);
9467 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9468 /* Key refused. Give up. */
9469 s->gotit = TRUE; /* reconsider message next loop */
9470 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
9471 continue; /* process this new message */
9473 logevent("Offer of public key accepted");
9476 * Actually attempt a serious authentication using
9479 if (flags & FLAG_VERBOSE) {
9480 c_write_str(ssh, "Authenticating with public key \"");
9481 c_write_str(ssh, s->publickey_comment);
9482 c_write_str(ssh, "\"\r\n");
9486 const char *error; /* not live over crReturn */
9487 if (s->privatekey_encrypted) {
9489 * Get a passphrase from the user.
9491 int ret; /* need not be kept over crReturn */
9492 s->cur_prompt = new_prompts(ssh->frontend);
9493 s->cur_prompt->to_server = FALSE;
9494 s->cur_prompt->name = dupstr("SSH key passphrase");
9495 add_prompt(s->cur_prompt,
9496 dupprintf("Passphrase for key \"%.100s\": ",
9497 s->publickey_comment),
9499 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9502 crWaitUntilV(!pktin);
9503 ret = get_userpass_input(s->cur_prompt,
9508 /* Failed to get a passphrase. Terminate. */
9509 free_prompts(s->cur_prompt);
9510 ssh_disconnect(ssh, NULL,
9511 "Unable to authenticate",
9512 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9517 dupstr(s->cur_prompt->prompts[0]->result);
9518 free_prompts(s->cur_prompt);
9520 passphrase = NULL; /* no passphrase needed */
9524 * Try decrypting the key.
9526 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9527 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
9529 /* burn the evidence */
9530 smemclr(passphrase, strlen(passphrase));
9533 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
9535 (key == SSH2_WRONG_PASSPHRASE)) {
9536 c_write_str(ssh, "Wrong passphrase\r\n");
9538 /* and loop again */
9540 c_write_str(ssh, "Unable to load private key (");
9541 c_write_str(ssh, error);
9542 c_write_str(ssh, ")\r\n");
9544 break; /* try something else */
9550 unsigned char *pkblob, *sigblob, *sigdata;
9551 int pkblob_len, sigblob_len, sigdata_len;
9555 * We have loaded the private key and the server
9556 * has announced that it's willing to accept it.
9557 * Hallelujah. Generate a signature and send it.
9559 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9560 ssh2_pkt_addstring(s->pktout, ssh->username);
9561 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9562 /* service requested */
9563 ssh2_pkt_addstring(s->pktout, "publickey");
9565 ssh2_pkt_addbool(s->pktout, TRUE);
9566 /* signature follows */
9567 ssh2_pkt_addstring(s->pktout, key->alg->name);
9568 pkblob = key->alg->public_blob(key->data,
9570 ssh2_pkt_addstring_start(s->pktout);
9571 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
9575 * The data to be signed is:
9579 * followed by everything so far placed in the
9582 sigdata_len = s->pktout->length - 5 + 4 +
9583 ssh->v2_session_id_len;
9584 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9586 sigdata = snewn(sigdata_len, unsigned char);
9588 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9589 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
9592 memcpy(sigdata+p, ssh->v2_session_id,
9593 ssh->v2_session_id_len);
9594 p += ssh->v2_session_id_len;
9595 memcpy(sigdata+p, s->pktout->data + 5,
9596 s->pktout->length - 5);
9597 p += s->pktout->length - 5;
9598 assert(p == sigdata_len);
9599 sigblob = key->alg->sign(key->data, (char *)sigdata,
9600 sigdata_len, &sigblob_len);
9601 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
9602 sigblob, sigblob_len);
9607 ssh2_pkt_send(ssh, s->pktout);
9608 logevent("Sent public key signature");
9609 s->type = AUTH_TYPE_PUBLICKEY;
9610 key->alg->freekey(key->data);
9611 sfree(key->comment);
9616 } else if (s->can_gssapi && !s->tried_gssapi) {
9618 /* GSSAPI Authentication */
9623 s->type = AUTH_TYPE_GSSAPI;
9624 s->tried_gssapi = TRUE;
9626 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
9629 * Pick the highest GSS library on the preference
9635 for (i = 0; i < ngsslibs; i++) {
9636 int want_id = conf_get_int_int(ssh->conf,
9637 CONF_ssh_gsslist, i);
9638 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
9639 if (ssh->gsslibs->libraries[j].id == want_id) {
9640 s->gsslib = &ssh->gsslibs->libraries[j];
9641 goto got_gsslib; /* double break */
9646 * We always expect to have found something in
9647 * the above loop: we only came here if there
9648 * was at least one viable GSS library, and the
9649 * preference list should always mention
9650 * everything and only change the order.
9655 if (s->gsslib->gsslogmsg)
9656 logevent(s->gsslib->gsslogmsg);
9658 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
9659 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9660 ssh2_pkt_addstring(s->pktout, ssh->username);
9661 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9662 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
9663 logevent("Attempting GSSAPI authentication");
9665 /* add mechanism info */
9666 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
9668 /* number of GSSAPI mechanisms */
9669 ssh2_pkt_adduint32(s->pktout,1);
9671 /* length of OID + 2 */
9672 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
9673 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
9676 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
9678 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
9680 ssh2_pkt_send(ssh, s->pktout);
9681 crWaitUntilV(pktin);
9682 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
9683 logevent("GSSAPI authentication request refused");
9687 /* check returned packet ... */
9689 ssh_pkt_getstring(pktin, &data, &len);
9690 s->gss_rcvtok.value = data;
9691 s->gss_rcvtok.length = len;
9692 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
9693 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
9694 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
9695 memcmp((char *)s->gss_rcvtok.value + 2,
9696 s->gss_buf.value,s->gss_buf.length) ) {
9697 logevent("GSSAPI authentication - wrong response from server");
9701 /* now start running */
9702 s->gss_stat = s->gsslib->import_name(s->gsslib,
9705 if (s->gss_stat != SSH_GSS_OK) {
9706 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
9707 logevent("GSSAPI import name failed - Bad service name");
9709 logevent("GSSAPI import name failed");
9713 /* fetch TGT into GSS engine */
9714 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
9716 if (s->gss_stat != SSH_GSS_OK) {
9717 logevent("GSSAPI authentication failed to get credentials");
9718 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9722 /* initial tokens are empty */
9723 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
9724 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
9726 /* now enter the loop */
9728 s->gss_stat = s->gsslib->init_sec_context
9732 conf_get_int(ssh->conf, CONF_gssapifwd),
9736 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
9737 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
9738 logevent("GSSAPI authentication initialisation failed");
9740 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
9741 &s->gss_buf) == SSH_GSS_OK) {
9742 logevent(s->gss_buf.value);
9743 sfree(s->gss_buf.value);
9748 logevent("GSSAPI authentication initialised");
9750 /* Client and server now exchange tokens until GSSAPI
9751 * no longer says CONTINUE_NEEDED */
9753 if (s->gss_sndtok.length != 0) {
9754 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
9755 ssh_pkt_addstring_start(s->pktout);
9756 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
9757 ssh2_pkt_send(ssh, s->pktout);
9758 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
9761 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
9762 crWaitUntilV(pktin);
9763 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
9764 logevent("GSSAPI authentication - bad server response");
9765 s->gss_stat = SSH_GSS_FAILURE;
9768 ssh_pkt_getstring(pktin, &data, &len);
9769 s->gss_rcvtok.value = data;
9770 s->gss_rcvtok.length = len;
9772 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
9774 if (s->gss_stat != SSH_GSS_OK) {
9775 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9776 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9779 logevent("GSSAPI authentication loop finished OK");
9781 /* Now send the MIC */
9783 s->pktout = ssh2_pkt_init(0);
9784 micoffset = s->pktout->length;
9785 ssh_pkt_addstring_start(s->pktout);
9786 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
9787 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
9788 ssh_pkt_addstring(s->pktout, ssh->username);
9789 ssh_pkt_addstring(s->pktout, "ssh-connection");
9790 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
9792 s->gss_buf.value = (char *)s->pktout->data + micoffset;
9793 s->gss_buf.length = s->pktout->length - micoffset;
9795 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
9796 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
9797 ssh_pkt_addstring_start(s->pktout);
9798 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
9799 ssh2_pkt_send(ssh, s->pktout);
9800 s->gsslib->free_mic(s->gsslib, &mic);
9804 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9805 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9808 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
9811 * Keyboard-interactive authentication.
9814 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
9816 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
9818 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9819 ssh2_pkt_addstring(s->pktout, ssh->username);
9820 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9821 /* service requested */
9822 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
9824 ssh2_pkt_addstring(s->pktout, ""); /* lang */
9825 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
9826 ssh2_pkt_send(ssh, s->pktout);
9828 logevent("Attempting keyboard-interactive authentication");
9830 crWaitUntilV(pktin);
9831 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
9832 /* Server is not willing to do keyboard-interactive
9833 * at all (or, bizarrely but legally, accepts the
9834 * user without actually issuing any prompts).
9835 * Give up on it entirely. */
9837 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
9838 s->kbd_inter_refused = TRUE; /* don't try it again */
9843 * Loop while the server continues to send INFO_REQUESTs.
9845 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
9847 char *name, *inst, *lang;
9848 int name_len, inst_len, lang_len;
9852 * We've got a fresh USERAUTH_INFO_REQUEST.
9853 * Get the preamble and start building a prompt.
9855 ssh_pkt_getstring(pktin, &name, &name_len);
9856 ssh_pkt_getstring(pktin, &inst, &inst_len);
9857 ssh_pkt_getstring(pktin, &lang, &lang_len);
9858 s->cur_prompt = new_prompts(ssh->frontend);
9859 s->cur_prompt->to_server = TRUE;
9862 * Get any prompt(s) from the packet.
9864 s->num_prompts = ssh_pkt_getuint32(pktin);
9865 for (i = 0; i < s->num_prompts; i++) {
9869 static char noprompt[] =
9870 "<server failed to send prompt>: ";
9872 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9873 echo = ssh2_pkt_getbool(pktin);
9876 prompt_len = lenof(noprompt)-1;
9878 add_prompt(s->cur_prompt,
9879 dupprintf("%.*s", prompt_len, prompt),
9884 /* FIXME: better prefix to distinguish from
9886 s->cur_prompt->name =
9887 dupprintf("SSH server: %.*s", name_len, name);
9888 s->cur_prompt->name_reqd = TRUE;
9890 s->cur_prompt->name =
9891 dupstr("SSH server authentication");
9892 s->cur_prompt->name_reqd = FALSE;
9894 /* We add a prefix to try to make it clear that a prompt
9895 * has come from the server.
9896 * FIXME: ugly to print "Using..." in prompt _every_
9897 * time round. Can this be done more subtly? */
9898 /* Special case: for reasons best known to themselves,
9899 * some servers send k-i requests with no prompts and
9900 * nothing to display. Keep quiet in this case. */
9901 if (s->num_prompts || name_len || inst_len) {
9902 s->cur_prompt->instruction =
9903 dupprintf("Using keyboard-interactive authentication.%s%.*s",
9904 inst_len ? "\n" : "", inst_len, inst);
9905 s->cur_prompt->instr_reqd = TRUE;
9907 s->cur_prompt->instr_reqd = FALSE;
9911 * Display any instructions, and get the user's
9915 int ret; /* not live over crReturn */
9916 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9919 crWaitUntilV(!pktin);
9920 ret = get_userpass_input(s->cur_prompt, in, inlen);
9925 * Failed to get responses. Terminate.
9927 free_prompts(s->cur_prompt);
9928 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9929 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9936 * Send the response(s) to the server.
9938 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
9939 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
9940 for (i=0; i < s->num_prompts; i++) {
9941 ssh2_pkt_addstring(s->pktout,
9942 s->cur_prompt->prompts[i]->result);
9944 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9947 * Free the prompts structure from this iteration.
9948 * If there's another, a new one will be allocated
9949 * when we return to the top of this while loop.
9951 free_prompts(s->cur_prompt);
9954 * Get the next packet in case it's another
9957 crWaitUntilV(pktin);
9962 * We should have SUCCESS or FAILURE now.
9966 } else if (s->can_passwd) {
9969 * Plain old password authentication.
9971 int ret; /* not live over crReturn */
9972 int changereq_first_time; /* not live over crReturn */
9974 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
9976 s->cur_prompt = new_prompts(ssh->frontend);
9977 s->cur_prompt->to_server = TRUE;
9978 s->cur_prompt->name = dupstr("SSH password");
9979 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
9984 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9987 crWaitUntilV(!pktin);
9988 ret = get_userpass_input(s->cur_prompt, in, inlen);
9993 * Failed to get responses. Terminate.
9995 free_prompts(s->cur_prompt);
9996 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9997 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10002 * Squirrel away the password. (We may need it later if
10003 * asked to change it.)
10005 s->password = dupstr(s->cur_prompt->prompts[0]->result);
10006 free_prompts(s->cur_prompt);
10009 * Send the password packet.
10011 * We pad out the password packet to 256 bytes to make
10012 * it harder for an attacker to find the length of the
10015 * Anyone using a password longer than 256 bytes
10016 * probably doesn't have much to worry about from
10017 * people who find out how long their password is!
10019 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10020 ssh2_pkt_addstring(s->pktout, ssh->username);
10021 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10022 /* service requested */
10023 ssh2_pkt_addstring(s->pktout, "password");
10024 ssh2_pkt_addbool(s->pktout, FALSE);
10025 ssh2_pkt_addstring(s->pktout, s->password);
10026 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10027 logevent("Sent password");
10028 s->type = AUTH_TYPE_PASSWORD;
10031 * Wait for next packet, in case it's a password change
10034 crWaitUntilV(pktin);
10035 changereq_first_time = TRUE;
10037 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
10040 * We're being asked for a new password
10041 * (perhaps not for the first time).
10042 * Loop until the server accepts it.
10045 int got_new = FALSE; /* not live over crReturn */
10046 char *prompt; /* not live over crReturn */
10047 int prompt_len; /* not live over crReturn */
10051 if (changereq_first_time)
10052 msg = "Server requested password change";
10054 msg = "Server rejected new password";
10056 c_write_str(ssh, msg);
10057 c_write_str(ssh, "\r\n");
10060 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
10062 s->cur_prompt = new_prompts(ssh->frontend);
10063 s->cur_prompt->to_server = TRUE;
10064 s->cur_prompt->name = dupstr("New SSH password");
10065 s->cur_prompt->instruction =
10066 dupprintf("%.*s", prompt_len, prompt);
10067 s->cur_prompt->instr_reqd = TRUE;
10069 * There's no explicit requirement in the protocol
10070 * for the "old" passwords in the original and
10071 * password-change messages to be the same, and
10072 * apparently some Cisco kit supports password change
10073 * by the user entering a blank password originally
10074 * and the real password subsequently, so,
10075 * reluctantly, we prompt for the old password again.
10077 * (On the other hand, some servers don't even bother
10078 * to check this field.)
10080 add_prompt(s->cur_prompt,
10081 dupstr("Current password (blank for previously entered password): "),
10083 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
10085 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
10089 * Loop until the user manages to enter the same
10094 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10097 crWaitUntilV(!pktin);
10098 ret = get_userpass_input(s->cur_prompt, in, inlen);
10103 * Failed to get responses. Terminate.
10105 /* burn the evidence */
10106 free_prompts(s->cur_prompt);
10107 smemclr(s->password, strlen(s->password));
10108 sfree(s->password);
10109 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10110 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10116 * If the user specified a new original password
10117 * (IYSWIM), overwrite any previously specified
10119 * (A side effect is that the user doesn't have to
10120 * re-enter it if they louse up the new password.)
10122 if (s->cur_prompt->prompts[0]->result[0]) {
10123 smemclr(s->password, strlen(s->password));
10124 /* burn the evidence */
10125 sfree(s->password);
10127 dupstr(s->cur_prompt->prompts[0]->result);
10131 * Check the two new passwords match.
10133 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
10134 s->cur_prompt->prompts[2]->result)
10137 /* They don't. Silly user. */
10138 c_write_str(ssh, "Passwords do not match\r\n");
10143 * Send the new password (along with the old one).
10144 * (see above for padding rationale)
10146 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10147 ssh2_pkt_addstring(s->pktout, ssh->username);
10148 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10149 /* service requested */
10150 ssh2_pkt_addstring(s->pktout, "password");
10151 ssh2_pkt_addbool(s->pktout, TRUE);
10152 ssh2_pkt_addstring(s->pktout, s->password);
10153 ssh2_pkt_addstring(s->pktout,
10154 s->cur_prompt->prompts[1]->result);
10155 free_prompts(s->cur_prompt);
10156 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10157 logevent("Sent new password");
10160 * Now see what the server has to say about it.
10161 * (If it's CHANGEREQ again, it's not happy with the
10164 crWaitUntilV(pktin);
10165 changereq_first_time = FALSE;
10170 * We need to reexamine the current pktin at the top
10171 * of the loop. Either:
10172 * - we weren't asked to change password at all, in
10173 * which case it's a SUCCESS or FAILURE with the
10175 * - we sent a new password, and the server was
10176 * either OK with it (SUCCESS or FAILURE w/partial
10177 * success) or unhappy with the _old_ password
10178 * (FAILURE w/o partial success)
10179 * In any of these cases, we go back to the top of
10180 * the loop and start again.
10185 * We don't need the old password any more, in any
10186 * case. Burn the evidence.
10188 smemclr(s->password, strlen(s->password));
10189 sfree(s->password);
10192 char *str = dupprintf("No supported authentication methods available"
10193 " (server sent: %.*s)",
10196 ssh_disconnect(ssh, str,
10197 "No supported authentication methods available",
10198 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
10208 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
10210 /* Clear up various bits and pieces from authentication. */
10211 if (s->publickey_blob) {
10212 sfree(s->publickey_algorithm);
10213 sfree(s->publickey_blob);
10214 sfree(s->publickey_comment);
10216 if (s->agent_response)
10217 sfree(s->agent_response);
10219 if (s->userauth_success && !ssh->bare_connection) {
10221 * We've just received USERAUTH_SUCCESS, and we haven't sent any
10222 * packets since. Signal the transport layer to consider enacting
10223 * delayed compression.
10225 * (Relying on we_are_in is not sufficient, as
10226 * draft-miller-secsh-compression-delayed is quite clear that it
10227 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
10228 * become set for other reasons.)
10230 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
10233 ssh->channels = newtree234(ssh_channelcmp);
10236 * Set up handlers for some connection protocol messages, so we
10237 * don't have to handle them repeatedly in this coroutine.
10239 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
10240 ssh2_msg_channel_window_adjust;
10241 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
10242 ssh2_msg_global_request;
10245 * Create the main session channel.
10247 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
10248 ssh->mainchan = NULL;
10250 ssh->mainchan = snew(struct ssh_channel);
10251 ssh->mainchan->ssh = ssh;
10252 ssh2_channel_init(ssh->mainchan);
10254 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
10256 * Just start a direct-tcpip channel and use it as the main
10259 ssh_send_port_open(ssh->mainchan,
10260 conf_get_str(ssh->conf, CONF_ssh_nc_host),
10261 conf_get_int(ssh->conf, CONF_ssh_nc_port),
10263 ssh->ncmode = TRUE;
10265 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
10266 logevent("Opening session as main channel");
10267 ssh2_pkt_send(ssh, s->pktout);
10268 ssh->ncmode = FALSE;
10270 crWaitUntilV(pktin);
10271 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
10272 bombout(("Server refused to open channel"));
10274 /* FIXME: error data comes back in FAILURE packet */
10276 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
10277 bombout(("Server's channel confirmation cited wrong channel"));
10280 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
10281 ssh->mainchan->halfopen = FALSE;
10282 ssh->mainchan->type = CHAN_MAINSESSION;
10283 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
10284 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
10285 add234(ssh->channels, ssh->mainchan);
10286 update_specials_menu(ssh->frontend);
10287 logevent("Opened main channel");
10291 * Now we have a channel, make dispatch table entries for
10292 * general channel-based messages.
10294 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
10295 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
10296 ssh2_msg_channel_data;
10297 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
10298 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
10299 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
10300 ssh2_msg_channel_open_confirmation;
10301 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
10302 ssh2_msg_channel_open_failure;
10303 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
10304 ssh2_msg_channel_request;
10305 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
10306 ssh2_msg_channel_open;
10307 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
10308 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
10311 * Now the connection protocol is properly up and running, with
10312 * all those dispatch table entries, so it's safe to let
10313 * downstreams start trying to open extra channels through us.
10315 if (ssh->connshare)
10316 share_activate(ssh->connshare, ssh->v_s);
10318 if (ssh->mainchan && ssh_is_simple(ssh)) {
10320 * This message indicates to the server that we promise
10321 * not to try to run any other channel in parallel with
10322 * this one, so it's safe for it to advertise a very large
10323 * window and leave the flow control to TCP.
10325 s->pktout = ssh2_chanreq_init(ssh->mainchan,
10326 "simple@putty.projects.tartarus.org",
10328 ssh2_pkt_send(ssh, s->pktout);
10332 * Enable port forwardings.
10334 ssh_setup_portfwd(ssh, ssh->conf);
10336 if (ssh->mainchan && !ssh->ncmode) {
10338 * Send the CHANNEL_REQUESTS for the main session channel.
10339 * Each one is handled by its own little asynchronous
10343 /* Potentially enable X11 forwarding. */
10344 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
10346 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
10348 if (!ssh->x11disp) {
10349 /* FIXME: return an error message from x11_setup_display */
10350 logevent("X11 forwarding not enabled: unable to"
10351 " initialise X display");
10353 ssh->x11auth = x11_invent_fake_auth
10354 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
10355 ssh->x11auth->disp = ssh->x11disp;
10357 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
10361 /* Potentially enable agent forwarding. */
10362 if (ssh_agent_forwarding_permitted(ssh))
10363 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
10365 /* Now allocate a pty for the session. */
10366 if (!conf_get_int(ssh->conf, CONF_nopty))
10367 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
10369 /* Send environment variables. */
10370 ssh2_setup_env(ssh->mainchan, NULL, NULL);
10373 * Start a shell or a remote command. We may have to attempt
10374 * this twice if the config data has provided a second choice
10381 if (ssh->fallback_cmd) {
10382 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
10383 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
10385 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
10386 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
10390 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
10391 ssh2_response_authconn, NULL);
10392 ssh2_pkt_addstring(s->pktout, cmd);
10394 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
10395 ssh2_response_authconn, NULL);
10396 ssh2_pkt_addstring(s->pktout, cmd);
10398 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
10399 ssh2_response_authconn, NULL);
10401 ssh2_pkt_send(ssh, s->pktout);
10403 crWaitUntilV(pktin);
10405 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
10406 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
10407 bombout(("Unexpected response to shell/command request:"
10408 " packet type %d", pktin->type));
10412 * We failed to start the command. If this is the
10413 * fallback command, we really are finished; if it's
10414 * not, and if the fallback command exists, try falling
10415 * back to it before complaining.
10417 if (!ssh->fallback_cmd &&
10418 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
10419 logevent("Primary command failed; attempting fallback");
10420 ssh->fallback_cmd = TRUE;
10423 bombout(("Server refused to start a shell/command"));
10426 logevent("Started a shell/command");
10431 ssh->editing = ssh->echoing = TRUE;
10434 ssh->state = SSH_STATE_SESSION;
10435 if (ssh->size_needed)
10436 ssh_size(ssh, ssh->term_width, ssh->term_height);
10437 if (ssh->eof_needed)
10438 ssh_special(ssh, TS_EOF);
10444 ldisc_echoedit_update(ssh->ldisc); /* cause ldisc to notice changes */
10449 s->try_send = FALSE;
10453 * _All_ the connection-layer packets we expect to
10454 * receive are now handled by the dispatch table.
10455 * Anything that reaches here must be bogus.
10458 bombout(("Strange packet received: type %d", pktin->type));
10460 } else if (ssh->mainchan) {
10462 * We have spare data. Add it to the channel buffer.
10464 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
10465 s->try_send = TRUE;
10469 struct ssh_channel *c;
10471 * Try to send data on all channels if we can.
10473 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
10474 ssh2_try_send_and_unthrottle(ssh, c);
10482 * Handlers for SSH-2 messages that might arrive at any moment.
10484 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
10486 /* log reason code in disconnect message */
10488 int reason, msglen;
10490 reason = ssh_pkt_getuint32(pktin);
10491 ssh_pkt_getstring(pktin, &msg, &msglen);
10493 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
10494 buf = dupprintf("Received disconnect message (%s)",
10495 ssh2_disconnect_reasons[reason]);
10497 buf = dupprintf("Received disconnect message (unknown"
10498 " type %d)", reason);
10502 buf = dupprintf("Disconnection message text: %.*s",
10505 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
10507 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
10508 ssh2_disconnect_reasons[reason] : "unknown",
10513 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
10515 /* log the debug message */
10519 /* XXX maybe we should actually take notice of the return value */
10520 ssh2_pkt_getbool(pktin);
10521 ssh_pkt_getstring(pktin, &msg, &msglen);
10523 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
10526 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
10528 do_ssh2_transport(ssh, NULL, 0, pktin);
10532 * Called if we receive a packet that isn't allowed by the protocol.
10533 * This only applies to packets whose meaning PuTTY understands.
10534 * Entirely unknown packets are handled below.
10536 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
10538 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
10539 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
10541 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
10545 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
10547 struct Packet *pktout;
10548 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
10549 ssh2_pkt_adduint32(pktout, pktin->sequence);
10551 * UNIMPLEMENTED messages MUST appear in the same order as the
10552 * messages they respond to. Hence, never queue them.
10554 ssh2_pkt_send_noqueue(ssh, pktout);
10558 * Handle the top-level SSH-2 protocol.
10560 static void ssh2_protocol_setup(Ssh ssh)
10565 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10567 for (i = 0; i < 256; i++)
10568 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10571 * Initially, we only accept transport messages (and a few generic
10572 * ones). do_ssh2_authconn will add more when it starts.
10573 * Messages that are understood but not currently acceptable go to
10574 * ssh2_msg_unexpected.
10576 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10577 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
10578 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
10579 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
10580 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
10581 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
10582 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
10583 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
10584 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
10585 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
10586 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
10587 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
10588 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
10589 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
10590 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
10591 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
10592 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
10593 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
10594 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
10595 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10596 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10597 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10598 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10599 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10600 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10601 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10602 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10603 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10604 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10605 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10606 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10607 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10608 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10611 * These messages have a special handler from the start.
10613 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10614 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
10615 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10618 static void ssh2_bare_connection_protocol_setup(Ssh ssh)
10623 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10625 for (i = 0; i < 256; i++)
10626 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10629 * Initially, we set all ssh-connection messages to 'unexpected';
10630 * do_ssh2_authconn will fill things in properly. We also handle a
10631 * couple of messages from the transport protocol which aren't
10632 * related to key exchange (UNIMPLEMENTED, IGNORE, DEBUG,
10635 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10636 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10637 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10638 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10639 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10640 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10641 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10642 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10643 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10644 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10645 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10646 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10647 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10648 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10650 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10653 * These messages have a special handler from the start.
10655 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10656 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore;
10657 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10660 static void ssh2_timer(void *ctx, unsigned long now)
10662 Ssh ssh = (Ssh)ctx;
10664 if (ssh->state == SSH_STATE_CLOSED)
10667 if (!ssh->kex_in_progress && !ssh->bare_connection &&
10668 conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
10669 now == ssh->next_rekey) {
10670 do_ssh2_transport(ssh, "timeout", -1, NULL);
10674 static void ssh2_protocol(Ssh ssh, const void *vin, int inlen,
10675 struct Packet *pktin)
10677 const unsigned char *in = (const unsigned char *)vin;
10678 if (ssh->state == SSH_STATE_CLOSED)
10682 ssh->incoming_data_size += pktin->encrypted_len;
10683 if (!ssh->kex_in_progress &&
10684 ssh->max_data_size != 0 &&
10685 ssh->incoming_data_size > ssh->max_data_size)
10686 do_ssh2_transport(ssh, "too much data received", -1, NULL);
10690 ssh->packet_dispatch[pktin->type](ssh, pktin);
10691 else if (!ssh->protocol_initial_phase_done)
10692 do_ssh2_transport(ssh, in, inlen, pktin);
10694 do_ssh2_authconn(ssh, in, inlen, pktin);
10697 static void ssh2_bare_connection_protocol(Ssh ssh, const void *vin, int inlen,
10698 struct Packet *pktin)
10700 const unsigned char *in = (const unsigned char *)vin;
10701 if (ssh->state == SSH_STATE_CLOSED)
10705 ssh->packet_dispatch[pktin->type](ssh, pktin);
10707 do_ssh2_authconn(ssh, in, inlen, pktin);
10710 static void ssh_cache_conf_values(Ssh ssh)
10712 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
10716 * Called to set up the connection.
10718 * Returns an error message, or NULL on success.
10720 static const char *ssh_init(void *frontend_handle, void **backend_handle,
10722 const char *host, int port, char **realhost,
10723 int nodelay, int keepalive)
10728 ssh = snew(struct ssh_tag);
10729 ssh->conf = conf_copy(conf);
10730 ssh_cache_conf_values(ssh);
10731 ssh->version = 0; /* when not ready yet */
10733 ssh->cipher = NULL;
10734 ssh->v1_cipher_ctx = NULL;
10735 ssh->crcda_ctx = NULL;
10736 ssh->cscipher = NULL;
10737 ssh->cs_cipher_ctx = NULL;
10738 ssh->sccipher = NULL;
10739 ssh->sc_cipher_ctx = NULL;
10741 ssh->cs_mac_ctx = NULL;
10743 ssh->sc_mac_ctx = NULL;
10744 ssh->cscomp = NULL;
10745 ssh->cs_comp_ctx = NULL;
10746 ssh->sccomp = NULL;
10747 ssh->sc_comp_ctx = NULL;
10749 ssh->kex_ctx = NULL;
10750 ssh->hostkey = NULL;
10751 ssh->hostkey_str = NULL;
10752 ssh->exitcode = -1;
10753 ssh->close_expected = FALSE;
10754 ssh->clean_exit = FALSE;
10755 ssh->state = SSH_STATE_PREPACKET;
10756 ssh->size_needed = FALSE;
10757 ssh->eof_needed = FALSE;
10759 ssh->logctx = NULL;
10760 ssh->deferred_send_data = NULL;
10761 ssh->deferred_len = 0;
10762 ssh->deferred_size = 0;
10763 ssh->fallback_cmd = 0;
10764 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
10765 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
10766 ssh->x11disp = NULL;
10767 ssh->x11auth = NULL;
10768 ssh->x11authtree = newtree234(x11_authcmp);
10769 ssh->v1_compressing = FALSE;
10770 ssh->v2_outgoing_sequence = 0;
10771 ssh->ssh1_rdpkt_crstate = 0;
10772 ssh->ssh2_rdpkt_crstate = 0;
10773 ssh->ssh2_bare_rdpkt_crstate = 0;
10774 ssh->ssh_gotdata_crstate = 0;
10775 ssh->do_ssh1_connection_crstate = 0;
10776 ssh->do_ssh_init_state = NULL;
10777 ssh->do_ssh_connection_init_state = NULL;
10778 ssh->do_ssh1_login_state = NULL;
10779 ssh->do_ssh2_transport_state = NULL;
10780 ssh->do_ssh2_authconn_state = NULL;
10783 ssh->mainchan = NULL;
10784 ssh->throttled_all = 0;
10785 ssh->v1_stdout_throttling = 0;
10787 ssh->queuelen = ssh->queuesize = 0;
10788 ssh->queueing = FALSE;
10789 ssh->qhead = ssh->qtail = NULL;
10790 ssh->deferred_rekey_reason = NULL;
10791 bufchain_init(&ssh->queued_incoming_data);
10792 ssh->frozen = FALSE;
10793 ssh->username = NULL;
10794 ssh->sent_console_eof = FALSE;
10795 ssh->got_pty = FALSE;
10796 ssh->bare_connection = FALSE;
10797 ssh->X11_fwd_enabled = FALSE;
10798 ssh->connshare = NULL;
10799 ssh->attempting_connshare = FALSE;
10801 *backend_handle = ssh;
10804 if (crypto_startup() == 0)
10805 return "Microsoft high encryption pack not installed!";
10808 ssh->frontend = frontend_handle;
10809 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
10810 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
10812 ssh->channels = NULL;
10813 ssh->rportfwds = NULL;
10814 ssh->portfwds = NULL;
10819 ssh->conn_throttle_count = 0;
10820 ssh->overall_bufsize = 0;
10821 ssh->fallback_cmd = 0;
10823 ssh->protocol = NULL;
10825 ssh->protocol_initial_phase_done = FALSE;
10827 ssh->pinger = NULL;
10829 ssh->incoming_data_size = ssh->outgoing_data_size =
10830 ssh->deferred_data_size = 0L;
10831 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10832 CONF_ssh_rekey_data));
10833 ssh->kex_in_progress = FALSE;
10836 ssh->gsslibs = NULL;
10839 random_ref(); /* do this now - may be needed by sharing setup code */
10841 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
10850 static void ssh_free(void *handle)
10852 Ssh ssh = (Ssh) handle;
10853 struct ssh_channel *c;
10854 struct ssh_rportfwd *pf;
10855 struct X11FakeAuth *auth;
10857 if (ssh->v1_cipher_ctx)
10858 ssh->cipher->free_context(ssh->v1_cipher_ctx);
10859 if (ssh->cs_cipher_ctx)
10860 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
10861 if (ssh->sc_cipher_ctx)
10862 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
10863 if (ssh->cs_mac_ctx)
10864 ssh->csmac->free_context(ssh->cs_mac_ctx);
10865 if (ssh->sc_mac_ctx)
10866 ssh->scmac->free_context(ssh->sc_mac_ctx);
10867 if (ssh->cs_comp_ctx) {
10869 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
10871 zlib_compress_cleanup(ssh->cs_comp_ctx);
10873 if (ssh->sc_comp_ctx) {
10875 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
10877 zlib_decompress_cleanup(ssh->sc_comp_ctx);
10880 dh_cleanup(ssh->kex_ctx);
10881 sfree(ssh->savedhost);
10883 while (ssh->queuelen-- > 0)
10884 ssh_free_packet(ssh->queue[ssh->queuelen]);
10887 while (ssh->qhead) {
10888 struct queued_handler *qh = ssh->qhead;
10889 ssh->qhead = qh->next;
10892 ssh->qhead = ssh->qtail = NULL;
10894 if (ssh->channels) {
10895 while ((c = delpos234(ssh->channels, 0)) != NULL) {
10898 if (c->u.x11.xconn != NULL)
10899 x11_close(c->u.x11.xconn);
10901 case CHAN_SOCKDATA:
10902 case CHAN_SOCKDATA_DORMANT:
10903 if (c->u.pfd.pf != NULL)
10904 pfd_close(c->u.pfd.pf);
10907 if (ssh->version == 2) {
10908 struct outstanding_channel_request *ocr, *nocr;
10909 ocr = c->v.v2.chanreq_head;
10911 ocr->handler(c, NULL, ocr->ctx);
10916 bufchain_clear(&c->v.v2.outbuffer);
10920 freetree234(ssh->channels);
10921 ssh->channels = NULL;
10924 if (ssh->connshare)
10925 sharestate_free(ssh->connshare);
10927 if (ssh->rportfwds) {
10928 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
10930 freetree234(ssh->rportfwds);
10931 ssh->rportfwds = NULL;
10933 sfree(ssh->deferred_send_data);
10935 x11_free_display(ssh->x11disp);
10936 while ((auth = delpos234(ssh->x11authtree, 0)) != NULL)
10937 x11_free_fake_auth(auth);
10938 freetree234(ssh->x11authtree);
10939 sfree(ssh->do_ssh_init_state);
10940 sfree(ssh->do_ssh1_login_state);
10941 sfree(ssh->do_ssh2_transport_state);
10942 sfree(ssh->do_ssh2_authconn_state);
10945 sfree(ssh->fullhostname);
10946 sfree(ssh->hostkey_str);
10947 if (ssh->crcda_ctx) {
10948 crcda_free_context(ssh->crcda_ctx);
10949 ssh->crcda_ctx = NULL;
10952 ssh_do_close(ssh, TRUE);
10953 expire_timer_context(ssh);
10955 pinger_free(ssh->pinger);
10956 bufchain_clear(&ssh->queued_incoming_data);
10957 sfree(ssh->username);
10958 conf_free(ssh->conf);
10961 ssh_gss_cleanup(ssh->gsslibs);
10969 * Reconfigure the SSH backend.
10971 static void ssh_reconfig(void *handle, Conf *conf)
10973 Ssh ssh = (Ssh) handle;
10974 const char *rekeying = NULL;
10975 int rekey_mandatory = FALSE;
10976 unsigned long old_max_data_size;
10979 pinger_reconfig(ssh->pinger, ssh->conf, conf);
10981 ssh_setup_portfwd(ssh, conf);
10983 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
10984 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
10986 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
10987 unsigned long now = GETTICKCOUNT();
10989 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
10990 rekeying = "timeout shortened";
10992 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
10996 old_max_data_size = ssh->max_data_size;
10997 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10998 CONF_ssh_rekey_data));
10999 if (old_max_data_size != ssh->max_data_size &&
11000 ssh->max_data_size != 0) {
11001 if (ssh->outgoing_data_size > ssh->max_data_size ||
11002 ssh->incoming_data_size > ssh->max_data_size)
11003 rekeying = "data limit lowered";
11006 if (conf_get_int(ssh->conf, CONF_compression) !=
11007 conf_get_int(conf, CONF_compression)) {
11008 rekeying = "compression setting changed";
11009 rekey_mandatory = TRUE;
11012 for (i = 0; i < CIPHER_MAX; i++)
11013 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
11014 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
11015 rekeying = "cipher settings changed";
11016 rekey_mandatory = TRUE;
11018 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
11019 conf_get_int(conf, CONF_ssh2_des_cbc)) {
11020 rekeying = "cipher settings changed";
11021 rekey_mandatory = TRUE;
11024 conf_free(ssh->conf);
11025 ssh->conf = conf_copy(conf);
11026 ssh_cache_conf_values(ssh);
11028 if (!ssh->bare_connection && rekeying) {
11029 if (!ssh->kex_in_progress) {
11030 do_ssh2_transport(ssh, rekeying, -1, NULL);
11031 } else if (rekey_mandatory) {
11032 ssh->deferred_rekey_reason = rekeying;
11038 * Called to send data down the SSH connection.
11040 static int ssh_send(void *handle, const char *buf, int len)
11042 Ssh ssh = (Ssh) handle;
11044 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
11047 ssh->protocol(ssh, (const unsigned char *)buf, len, 0);
11049 return ssh_sendbuffer(ssh);
11053 * Called to query the current amount of buffered stdin data.
11055 static int ssh_sendbuffer(void *handle)
11057 Ssh ssh = (Ssh) handle;
11058 int override_value;
11060 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
11064 * If the SSH socket itself has backed up, add the total backup
11065 * size on that to any individual buffer on the stdin channel.
11067 override_value = 0;
11068 if (ssh->throttled_all)
11069 override_value = ssh->overall_bufsize;
11071 if (ssh->version == 1) {
11072 return override_value;
11073 } else if (ssh->version == 2) {
11074 if (!ssh->mainchan)
11075 return override_value;
11077 return (override_value +
11078 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
11085 * Called to set the size of the window from SSH's POV.
11087 static void ssh_size(void *handle, int width, int height)
11089 Ssh ssh = (Ssh) handle;
11090 struct Packet *pktout;
11092 ssh->term_width = width;
11093 ssh->term_height = height;
11095 switch (ssh->state) {
11096 case SSH_STATE_BEFORE_SIZE:
11097 case SSH_STATE_PREPACKET:
11098 case SSH_STATE_CLOSED:
11099 break; /* do nothing */
11100 case SSH_STATE_INTERMED:
11101 ssh->size_needed = TRUE; /* buffer for later */
11103 case SSH_STATE_SESSION:
11104 if (!conf_get_int(ssh->conf, CONF_nopty)) {
11105 if (ssh->version == 1) {
11106 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
11107 PKT_INT, ssh->term_height,
11108 PKT_INT, ssh->term_width,
11109 PKT_INT, 0, PKT_INT, 0, PKT_END);
11110 } else if (ssh->mainchan) {
11111 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
11113 ssh2_pkt_adduint32(pktout, ssh->term_width);
11114 ssh2_pkt_adduint32(pktout, ssh->term_height);
11115 ssh2_pkt_adduint32(pktout, 0);
11116 ssh2_pkt_adduint32(pktout, 0);
11117 ssh2_pkt_send(ssh, pktout);
11125 * Return a list of the special codes that make sense in this
11128 static const struct telnet_special *ssh_get_specials(void *handle)
11130 static const struct telnet_special ssh1_ignore_special[] = {
11131 {"IGNORE message", TS_NOP}
11133 static const struct telnet_special ssh2_ignore_special[] = {
11134 {"IGNORE message", TS_NOP},
11136 static const struct telnet_special ssh2_rekey_special[] = {
11137 {"Repeat key exchange", TS_REKEY},
11139 static const struct telnet_special ssh2_session_specials[] = {
11142 /* These are the signal names defined by RFC 4254.
11143 * They include all the ISO C signals, but are a subset of the POSIX
11144 * required signals. */
11145 {"SIGINT (Interrupt)", TS_SIGINT},
11146 {"SIGTERM (Terminate)", TS_SIGTERM},
11147 {"SIGKILL (Kill)", TS_SIGKILL},
11148 {"SIGQUIT (Quit)", TS_SIGQUIT},
11149 {"SIGHUP (Hangup)", TS_SIGHUP},
11150 {"More signals", TS_SUBMENU},
11151 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
11152 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
11153 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
11154 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
11155 {NULL, TS_EXITMENU}
11157 static const struct telnet_special specials_end[] = {
11158 {NULL, TS_EXITMENU}
11160 /* XXX review this length for any changes: */
11161 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
11162 lenof(ssh2_rekey_special) +
11163 lenof(ssh2_session_specials) +
11164 lenof(specials_end)];
11165 Ssh ssh = (Ssh) handle;
11167 #define ADD_SPECIALS(name) \
11169 assert((i + lenof(name)) <= lenof(ssh_specials)); \
11170 memcpy(&ssh_specials[i], name, sizeof name); \
11171 i += lenof(name); \
11174 if (ssh->version == 1) {
11175 /* Don't bother offering IGNORE if we've decided the remote
11176 * won't cope with it, since we wouldn't bother sending it if
11178 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11179 ADD_SPECIALS(ssh1_ignore_special);
11180 } else if (ssh->version == 2) {
11181 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
11182 ADD_SPECIALS(ssh2_ignore_special);
11183 if (!(ssh->remote_bugs & BUG_SSH2_REKEY) && !ssh->bare_connection)
11184 ADD_SPECIALS(ssh2_rekey_special);
11186 ADD_SPECIALS(ssh2_session_specials);
11187 } /* else we're not ready yet */
11190 ADD_SPECIALS(specials_end);
11191 return ssh_specials;
11195 #undef ADD_SPECIALS
11199 * Send special codes. TS_EOF is useful for `plink', so you
11200 * can send an EOF and collect resulting output (e.g. `plink
11203 static void ssh_special(void *handle, Telnet_Special code)
11205 Ssh ssh = (Ssh) handle;
11206 struct Packet *pktout;
11208 if (code == TS_EOF) {
11209 if (ssh->state != SSH_STATE_SESSION) {
11211 * Buffer the EOF in case we are pre-SESSION, so we can
11212 * send it as soon as we reach SESSION.
11214 if (code == TS_EOF)
11215 ssh->eof_needed = TRUE;
11218 if (ssh->version == 1) {
11219 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
11220 } else if (ssh->mainchan) {
11221 sshfwd_write_eof(ssh->mainchan);
11222 ssh->send_ok = 0; /* now stop trying to read from stdin */
11224 logevent("Sent EOF message");
11225 } else if (code == TS_PING || code == TS_NOP) {
11226 if (ssh->state == SSH_STATE_CLOSED
11227 || ssh->state == SSH_STATE_PREPACKET) return;
11228 if (ssh->version == 1) {
11229 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11230 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
11232 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
11233 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
11234 ssh2_pkt_addstring_start(pktout);
11235 ssh2_pkt_send_noqueue(ssh, pktout);
11238 } else if (code == TS_REKEY) {
11239 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11240 ssh->version == 2) {
11241 do_ssh2_transport(ssh, "at user request", -1, NULL);
11243 } else if (code == TS_BRK) {
11244 if (ssh->state == SSH_STATE_CLOSED
11245 || ssh->state == SSH_STATE_PREPACKET) return;
11246 if (ssh->version == 1) {
11247 logevent("Unable to send BREAK signal in SSH-1");
11248 } else if (ssh->mainchan) {
11249 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
11250 ssh2_pkt_adduint32(pktout, 0); /* default break length */
11251 ssh2_pkt_send(ssh, pktout);
11254 /* Is is a POSIX signal? */
11255 const char *signame = NULL;
11256 if (code == TS_SIGABRT) signame = "ABRT";
11257 if (code == TS_SIGALRM) signame = "ALRM";
11258 if (code == TS_SIGFPE) signame = "FPE";
11259 if (code == TS_SIGHUP) signame = "HUP";
11260 if (code == TS_SIGILL) signame = "ILL";
11261 if (code == TS_SIGINT) signame = "INT";
11262 if (code == TS_SIGKILL) signame = "KILL";
11263 if (code == TS_SIGPIPE) signame = "PIPE";
11264 if (code == TS_SIGQUIT) signame = "QUIT";
11265 if (code == TS_SIGSEGV) signame = "SEGV";
11266 if (code == TS_SIGTERM) signame = "TERM";
11267 if (code == TS_SIGUSR1) signame = "USR1";
11268 if (code == TS_SIGUSR2) signame = "USR2";
11269 /* The SSH-2 protocol does in principle support arbitrary named
11270 * signals, including signame@domain, but we don't support those. */
11272 /* It's a signal. */
11273 if (ssh->version == 2 && ssh->mainchan) {
11274 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
11275 ssh2_pkt_addstring(pktout, signame);
11276 ssh2_pkt_send(ssh, pktout);
11277 logeventf(ssh, "Sent signal SIG%s", signame);
11280 /* Never heard of it. Do nothing */
11285 void *new_sock_channel(void *handle, struct PortForwarding *pf)
11287 Ssh ssh = (Ssh) handle;
11288 struct ssh_channel *c;
11289 c = snew(struct ssh_channel);
11292 ssh2_channel_init(c);
11293 c->halfopen = TRUE;
11294 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
11296 add234(ssh->channels, c);
11300 unsigned ssh_alloc_sharing_channel(Ssh ssh, void *sharing_ctx)
11302 struct ssh_channel *c;
11303 c = snew(struct ssh_channel);
11306 ssh2_channel_init(c);
11307 c->type = CHAN_SHARING;
11308 c->u.sharing.ctx = sharing_ctx;
11309 add234(ssh->channels, c);
11313 void ssh_delete_sharing_channel(Ssh ssh, unsigned localid)
11315 struct ssh_channel *c;
11317 c = find234(ssh->channels, &localid, ssh_channelfind);
11319 ssh_channel_destroy(c);
11322 void ssh_send_packet_from_downstream(Ssh ssh, unsigned id, int type,
11323 const void *data, int datalen,
11324 const char *additional_log_text)
11326 struct Packet *pkt;
11328 pkt = ssh2_pkt_init(type);
11329 pkt->downstream_id = id;
11330 pkt->additional_log_text = additional_log_text;
11331 ssh2_pkt_adddata(pkt, data, datalen);
11332 ssh2_pkt_send(ssh, pkt);
11336 * This is called when stdout/stderr (the entity to which
11337 * from_backend sends data) manages to clear some backlog.
11339 static void ssh_unthrottle(void *handle, int bufsize)
11341 Ssh ssh = (Ssh) handle;
11344 if (ssh->version == 1) {
11345 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
11346 ssh->v1_stdout_throttling = 0;
11347 ssh_throttle_conn(ssh, -1);
11350 if (ssh->mainchan) {
11351 ssh2_set_window(ssh->mainchan,
11352 bufsize < ssh->mainchan->v.v2.locmaxwin ?
11353 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
11354 if (ssh_is_simple(ssh))
11357 buflimit = ssh->mainchan->v.v2.locmaxwin;
11358 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
11359 ssh->mainchan->throttling_conn = 0;
11360 ssh_throttle_conn(ssh, -1);
11366 * Now process any SSH connection data that was stashed in our
11367 * queue while we were frozen.
11369 ssh_process_queued_incoming_data(ssh);
11372 void ssh_send_port_open(void *channel, const char *hostname, int port,
11375 struct ssh_channel *c = (struct ssh_channel *)channel;
11377 struct Packet *pktout;
11379 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
11381 if (ssh->version == 1) {
11382 send_packet(ssh, SSH1_MSG_PORT_OPEN,
11383 PKT_INT, c->localid,
11386 /* PKT_STR, <org:orgport>, */
11389 pktout = ssh2_chanopen_init(c, "direct-tcpip");
11391 char *trimmed_host = host_strduptrim(hostname);
11392 ssh2_pkt_addstring(pktout, trimmed_host);
11393 sfree(trimmed_host);
11395 ssh2_pkt_adduint32(pktout, port);
11397 * We make up values for the originator data; partly it's
11398 * too much hassle to keep track, and partly I'm not
11399 * convinced the server should be told details like that
11400 * about my local network configuration.
11401 * The "originator IP address" is syntactically a numeric
11402 * IP address, and some servers (e.g., Tectia) get upset
11403 * if it doesn't match this syntax.
11405 ssh2_pkt_addstring(pktout, "0.0.0.0");
11406 ssh2_pkt_adduint32(pktout, 0);
11407 ssh2_pkt_send(ssh, pktout);
11411 static int ssh_connected(void *handle)
11413 Ssh ssh = (Ssh) handle;
11414 return ssh->s != NULL;
11417 static int ssh_sendok(void *handle)
11419 Ssh ssh = (Ssh) handle;
11420 return ssh->send_ok;
11423 static int ssh_ldisc(void *handle, int option)
11425 Ssh ssh = (Ssh) handle;
11426 if (option == LD_ECHO)
11427 return ssh->echoing;
11428 if (option == LD_EDIT)
11429 return ssh->editing;
11433 static void ssh_provide_ldisc(void *handle, void *ldisc)
11435 Ssh ssh = (Ssh) handle;
11436 ssh->ldisc = ldisc;
11439 static void ssh_provide_logctx(void *handle, void *logctx)
11441 Ssh ssh = (Ssh) handle;
11442 ssh->logctx = logctx;
11445 static int ssh_return_exitcode(void *handle)
11447 Ssh ssh = (Ssh) handle;
11448 if (ssh->s != NULL)
11451 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
11455 * cfg_info for SSH is the protocol running in this session.
11456 * (1 or 2 for the full SSH-1 or SSH-2 protocol; -1 for the bare
11457 * SSH-2 connection protocol, i.e. a downstream; 0 for not-decided-yet.)
11459 static int ssh_cfg_info(void *handle)
11461 Ssh ssh = (Ssh) handle;
11462 if (ssh->version == 0)
11463 return 0; /* don't know yet */
11464 else if (ssh->bare_connection)
11467 return ssh->version;
11471 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
11472 * that fails. This variable is the means by which scp.c can reach
11473 * into the SSH code and find out which one it got.
11475 extern int ssh_fallback_cmd(void *handle)
11477 Ssh ssh = (Ssh) handle;
11478 return ssh->fallback_cmd;
11481 Backend ssh_backend = {
11491 ssh_return_exitcode,
11495 ssh_provide_logctx,