28 * Packet type contexts, so that ssh2_pkt_type can correctly decode
29 * the ambiguous type numbers back into the correct type strings.
40 SSH2_PKTCTX_PUBLICKEY,
46 static const char *const ssh2_disconnect_reasons[] = {
48 "host not allowed to connect",
50 "key exchange failed",
51 "host authentication failed",
54 "service not available",
55 "protocol version not supported",
56 "host key not verifiable",
59 "too many connections",
60 "auth cancelled by user",
61 "no more auth methods available",
66 * Various remote-bug flags.
68 #define BUG_CHOKES_ON_SSH1_IGNORE 1
69 #define BUG_SSH2_HMAC 2
70 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
71 #define BUG_CHOKES_ON_RSA 8
72 #define BUG_SSH2_RSA_PADDING 16
73 #define BUG_SSH2_DERIVEKEY 32
74 #define BUG_SSH2_REKEY 64
75 #define BUG_SSH2_PK_SESSIONID 128
76 #define BUG_SSH2_MAXPKT 256
77 #define BUG_CHOKES_ON_SSH2_IGNORE 512
78 #define BUG_CHOKES_ON_WINADJ 1024
79 #define BUG_SENDS_LATE_REQUEST_REPLY 2048
80 #define BUG_SSH2_OLDGEX 4096
82 #define DH_MIN_SIZE 1024
83 #define DH_MAX_SIZE 8192
86 * Codes for terminal modes.
87 * Most of these are the same in SSH-1 and SSH-2.
88 * This list is derived from RFC 4254 and
92 const char* const mode;
94 enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
96 /* "V" prefix discarded for special characters relative to SSH specs */
97 { "INTR", 1, TTY_OP_CHAR },
98 { "QUIT", 2, TTY_OP_CHAR },
99 { "ERASE", 3, TTY_OP_CHAR },
100 { "KILL", 4, TTY_OP_CHAR },
101 { "EOF", 5, TTY_OP_CHAR },
102 { "EOL", 6, TTY_OP_CHAR },
103 { "EOL2", 7, TTY_OP_CHAR },
104 { "START", 8, TTY_OP_CHAR },
105 { "STOP", 9, TTY_OP_CHAR },
106 { "SUSP", 10, TTY_OP_CHAR },
107 { "DSUSP", 11, TTY_OP_CHAR },
108 { "REPRINT", 12, TTY_OP_CHAR },
109 { "WERASE", 13, TTY_OP_CHAR },
110 { "LNEXT", 14, TTY_OP_CHAR },
111 { "FLUSH", 15, TTY_OP_CHAR },
112 { "SWTCH", 16, TTY_OP_CHAR },
113 { "STATUS", 17, TTY_OP_CHAR },
114 { "DISCARD", 18, TTY_OP_CHAR },
115 { "IGNPAR", 30, TTY_OP_BOOL },
116 { "PARMRK", 31, TTY_OP_BOOL },
117 { "INPCK", 32, TTY_OP_BOOL },
118 { "ISTRIP", 33, TTY_OP_BOOL },
119 { "INLCR", 34, TTY_OP_BOOL },
120 { "IGNCR", 35, TTY_OP_BOOL },
121 { "ICRNL", 36, TTY_OP_BOOL },
122 { "IUCLC", 37, TTY_OP_BOOL },
123 { "IXON", 38, TTY_OP_BOOL },
124 { "IXANY", 39, TTY_OP_BOOL },
125 { "IXOFF", 40, TTY_OP_BOOL },
126 { "IMAXBEL", 41, TTY_OP_BOOL },
127 { "ISIG", 50, TTY_OP_BOOL },
128 { "ICANON", 51, TTY_OP_BOOL },
129 { "XCASE", 52, TTY_OP_BOOL },
130 { "ECHO", 53, TTY_OP_BOOL },
131 { "ECHOE", 54, TTY_OP_BOOL },
132 { "ECHOK", 55, TTY_OP_BOOL },
133 { "ECHONL", 56, TTY_OP_BOOL },
134 { "NOFLSH", 57, TTY_OP_BOOL },
135 { "TOSTOP", 58, TTY_OP_BOOL },
136 { "IEXTEN", 59, TTY_OP_BOOL },
137 { "ECHOCTL", 60, TTY_OP_BOOL },
138 { "ECHOKE", 61, TTY_OP_BOOL },
139 { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */
140 { "OPOST", 70, TTY_OP_BOOL },
141 { "OLCUC", 71, TTY_OP_BOOL },
142 { "ONLCR", 72, TTY_OP_BOOL },
143 { "OCRNL", 73, TTY_OP_BOOL },
144 { "ONOCR", 74, TTY_OP_BOOL },
145 { "ONLRET", 75, TTY_OP_BOOL },
146 { "CS7", 90, TTY_OP_BOOL },
147 { "CS8", 91, TTY_OP_BOOL },
148 { "PARENB", 92, TTY_OP_BOOL },
149 { "PARODD", 93, TTY_OP_BOOL }
152 /* Miscellaneous other tty-related constants. */
153 #define SSH_TTY_OP_END 0
154 /* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */
155 #define SSH1_TTY_OP_ISPEED 192
156 #define SSH1_TTY_OP_OSPEED 193
157 #define SSH2_TTY_OP_ISPEED 128
158 #define SSH2_TTY_OP_OSPEED 129
160 /* Helper functions for parsing tty-related config. */
161 static unsigned int ssh_tty_parse_specchar(char *s)
166 ret = ctrlparse(s, &next);
167 if (!next) ret = s[0];
169 ret = 255; /* special value meaning "don't set" */
173 static unsigned int ssh_tty_parse_boolean(char *s)
175 if (stricmp(s, "yes") == 0 ||
176 stricmp(s, "on") == 0 ||
177 stricmp(s, "true") == 0 ||
178 stricmp(s, "+") == 0)
180 else if (stricmp(s, "no") == 0 ||
181 stricmp(s, "off") == 0 ||
182 stricmp(s, "false") == 0 ||
183 stricmp(s, "-") == 0)
184 return 0; /* false */
186 return (atoi(s) != 0);
189 #define translate(x) if (type == x) return #x
190 #define translatek(x,ctx) if (type == x && (pkt_kctx == ctx)) return #x
191 #define translatea(x,ctx) if (type == x && (pkt_actx == ctx)) return #x
192 static const char *ssh1_pkt_type(int type)
194 translate(SSH1_MSG_DISCONNECT);
195 translate(SSH1_SMSG_PUBLIC_KEY);
196 translate(SSH1_CMSG_SESSION_KEY);
197 translate(SSH1_CMSG_USER);
198 translate(SSH1_CMSG_AUTH_RSA);
199 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
200 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
201 translate(SSH1_CMSG_AUTH_PASSWORD);
202 translate(SSH1_CMSG_REQUEST_PTY);
203 translate(SSH1_CMSG_WINDOW_SIZE);
204 translate(SSH1_CMSG_EXEC_SHELL);
205 translate(SSH1_CMSG_EXEC_CMD);
206 translate(SSH1_SMSG_SUCCESS);
207 translate(SSH1_SMSG_FAILURE);
208 translate(SSH1_CMSG_STDIN_DATA);
209 translate(SSH1_SMSG_STDOUT_DATA);
210 translate(SSH1_SMSG_STDERR_DATA);
211 translate(SSH1_CMSG_EOF);
212 translate(SSH1_SMSG_EXIT_STATUS);
213 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
214 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
215 translate(SSH1_MSG_CHANNEL_DATA);
216 translate(SSH1_MSG_CHANNEL_CLOSE);
217 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
218 translate(SSH1_SMSG_X11_OPEN);
219 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
220 translate(SSH1_MSG_PORT_OPEN);
221 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
222 translate(SSH1_SMSG_AGENT_OPEN);
223 translate(SSH1_MSG_IGNORE);
224 translate(SSH1_CMSG_EXIT_CONFIRMATION);
225 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
226 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
227 translate(SSH1_MSG_DEBUG);
228 translate(SSH1_CMSG_REQUEST_COMPRESSION);
229 translate(SSH1_CMSG_AUTH_TIS);
230 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
231 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
232 translate(SSH1_CMSG_AUTH_CCARD);
233 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
234 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
237 static const char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx,
240 translatea(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,SSH2_PKTCTX_GSSAPI);
241 translatea(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,SSH2_PKTCTX_GSSAPI);
242 translatea(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,SSH2_PKTCTX_GSSAPI);
243 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERROR,SSH2_PKTCTX_GSSAPI);
244 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK,SSH2_PKTCTX_GSSAPI);
245 translatea(SSH2_MSG_USERAUTH_GSSAPI_MIC, SSH2_PKTCTX_GSSAPI);
246 translate(SSH2_MSG_DISCONNECT);
247 translate(SSH2_MSG_IGNORE);
248 translate(SSH2_MSG_UNIMPLEMENTED);
249 translate(SSH2_MSG_DEBUG);
250 translate(SSH2_MSG_SERVICE_REQUEST);
251 translate(SSH2_MSG_SERVICE_ACCEPT);
252 translate(SSH2_MSG_KEXINIT);
253 translate(SSH2_MSG_NEWKEYS);
254 translatek(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
255 translatek(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
256 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST_OLD, SSH2_PKTCTX_DHGEX);
257 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
258 translatek(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
259 translatek(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
260 translatek(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
261 translatek(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX);
262 translatek(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX);
263 translatek(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX);
264 translatek(SSH2_MSG_KEX_ECDH_INIT, SSH2_PKTCTX_ECDHKEX);
265 translatek(SSH2_MSG_KEX_ECDH_REPLY, SSH2_PKTCTX_ECDHKEX);
266 translate(SSH2_MSG_USERAUTH_REQUEST);
267 translate(SSH2_MSG_USERAUTH_FAILURE);
268 translate(SSH2_MSG_USERAUTH_SUCCESS);
269 translate(SSH2_MSG_USERAUTH_BANNER);
270 translatea(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
271 translatea(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
272 translatea(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
273 translatea(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
274 translate(SSH2_MSG_GLOBAL_REQUEST);
275 translate(SSH2_MSG_REQUEST_SUCCESS);
276 translate(SSH2_MSG_REQUEST_FAILURE);
277 translate(SSH2_MSG_CHANNEL_OPEN);
278 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
279 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
280 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
281 translate(SSH2_MSG_CHANNEL_DATA);
282 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
283 translate(SSH2_MSG_CHANNEL_EOF);
284 translate(SSH2_MSG_CHANNEL_CLOSE);
285 translate(SSH2_MSG_CHANNEL_REQUEST);
286 translate(SSH2_MSG_CHANNEL_SUCCESS);
287 translate(SSH2_MSG_CHANNEL_FAILURE);
293 /* Enumeration values for fields in SSH-1 packets */
295 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
299 * Coroutine mechanics for the sillier bits of the code. If these
300 * macros look impenetrable to you, you might find it helpful to
303 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
305 * which explains the theory behind these macros.
307 * In particular, if you are getting `case expression not constant'
308 * errors when building with MS Visual Studio, this is because MS's
309 * Edit and Continue debugging feature causes their compiler to
310 * violate ANSI C. To disable Edit and Continue debugging:
312 * - right-click ssh.c in the FileView
314 * - select the C/C++ tab and the General category
315 * - under `Debug info:', select anything _other_ than `Program
316 * Database for Edit and Continue'.
318 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
319 #define crBeginState crBegin(s->crLine)
320 #define crStateP(t, v) \
322 if (!(v)) { s = (v) = snew(struct t); s->crLine = 0; } \
324 #define crState(t) crStateP(t, ssh->t)
325 #define crFinish(z) } *crLine = 0; return (z); }
326 #define crFinishV } *crLine = 0; return; }
327 #define crFinishFree(z) } sfree(s); return (z); }
328 #define crFinishFreeV } sfree(s); return; }
329 #define crReturn(z) \
331 *crLine =__LINE__; return (z); case __LINE__:;\
335 *crLine=__LINE__; return; case __LINE__:;\
337 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
338 #define crStopV do{ *crLine = 0; return; }while(0)
339 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
340 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
344 static struct Packet *ssh1_pkt_init(int pkt_type);
345 static struct Packet *ssh2_pkt_init(int pkt_type);
346 static void ssh_pkt_ensure(struct Packet *, int length);
347 static void ssh_pkt_adddata(struct Packet *, const void *data, int len);
348 static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
349 static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
350 static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
351 static void ssh_pkt_addstring_start(struct Packet *);
352 static void ssh_pkt_addstring_str(struct Packet *, const char *data);
353 static void ssh_pkt_addstring_data(struct Packet *, const char *data, int len);
354 static void ssh_pkt_addstring(struct Packet *, const char *data);
355 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
356 static void ssh1_pkt_addmp(struct Packet *, Bignum b);
357 static void ssh2_pkt_addmp(struct Packet *, Bignum b);
358 static int ssh2_pkt_construct(Ssh, struct Packet *);
359 static void ssh2_pkt_send(Ssh, struct Packet *);
360 static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
361 static int do_ssh1_login(Ssh ssh, const unsigned char *in, int inlen,
362 struct Packet *pktin);
363 static void do_ssh2_authconn(Ssh ssh, const unsigned char *in, int inlen,
364 struct Packet *pktin);
365 static void ssh2_channel_check_close(struct ssh_channel *c);
366 static void ssh_channel_destroy(struct ssh_channel *c);
369 * Buffer management constants. There are several of these for
370 * various different purposes:
372 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
373 * on a local data stream before we throttle the whole SSH
374 * connection (in SSH-1 only). Throttling the whole connection is
375 * pretty drastic so we set this high in the hope it won't
378 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
379 * on the SSH connection itself before we defensively throttle
380 * _all_ local data streams. This is pretty drastic too (though
381 * thankfully unlikely in SSH-2 since the window mechanism should
382 * ensure that the server never has any need to throttle its end
383 * of the connection), so we set this high as well.
385 * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
388 * - OUR_V2_BIGWIN is the window size we advertise for the only
389 * channel in a simple connection. It must be <= INT_MAX.
391 * - OUR_V2_MAXPKT is the official "maximum packet size" we send
392 * to the remote side. This actually has nothing to do with the
393 * size of the _packet_, but is instead a limit on the amount
394 * of data we're willing to receive in a single SSH2 channel
397 * - OUR_V2_PACKETLIMIT is actually the maximum size of SSH
398 * _packet_ we're prepared to cope with. It must be a multiple
399 * of the cipher block size, and must be at least 35000.
402 #define SSH1_BUFFER_LIMIT 32768
403 #define SSH_MAX_BACKLOG 32768
404 #define OUR_V2_WINSIZE 16384
405 #define OUR_V2_BIGWIN 0x7fffffff
406 #define OUR_V2_MAXPKT 0x4000UL
407 #define OUR_V2_PACKETLIMIT 0x9000UL
409 const static struct ssh_signkey *hostkey_algs[] = {
411 &ssh_ecdsa_nistp256, &ssh_ecdsa_nistp384, &ssh_ecdsa_nistp521,
415 const static struct ssh_mac *macs[] = {
416 &ssh_hmac_sha256, &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
418 const static struct ssh_mac *buggymacs[] = {
419 &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
422 static void *ssh_comp_none_init(void)
426 static void ssh_comp_none_cleanup(void *handle)
429 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
430 unsigned char **outblock, int *outlen)
434 static int ssh_comp_none_disable(void *handle)
438 const static struct ssh_compress ssh_comp_none = {
440 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
441 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
442 ssh_comp_none_disable, NULL
444 extern const struct ssh_compress ssh_zlib;
445 const static struct ssh_compress *compressions[] = {
446 &ssh_zlib, &ssh_comp_none
449 enum { /* channel types */
454 CHAN_SOCKDATA_DORMANT, /* one the remote hasn't confirmed */
456 * CHAN_SHARING indicates a channel which is tracked here on
457 * behalf of a connection-sharing downstream. We do almost nothing
458 * with these channels ourselves: all messages relating to them
459 * get thrown straight to sshshare.c and passed on almost
460 * unmodified to downstream.
464 * CHAN_ZOMBIE is used to indicate a channel for which we've
465 * already destroyed the local data source: for instance, if a
466 * forwarded port experiences a socket error on the local side, we
467 * immediately destroy its local socket and turn the SSH channel
473 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
474 typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
475 typedef void (*cchandler_fn_t)(struct ssh_channel *, struct Packet *, void *);
478 * Each channel has a queue of outstanding CHANNEL_REQUESTS and their
481 struct outstanding_channel_request {
482 cchandler_fn_t handler;
484 struct outstanding_channel_request *next;
488 * 2-3-4 tree storing channels.
491 Ssh ssh; /* pointer back to main context */
492 unsigned remoteid, localid;
494 /* True if we opened this channel but server hasn't confirmed. */
497 * In SSH-1, this value contains four bits:
499 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
500 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
501 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
502 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
504 * A channel is completely finished with when all four bits are set.
506 * In SSH-2, the four bits mean:
508 * 1 We have sent SSH2_MSG_CHANNEL_EOF.
509 * 2 We have sent SSH2_MSG_CHANNEL_CLOSE.
510 * 4 We have received SSH2_MSG_CHANNEL_EOF.
511 * 8 We have received SSH2_MSG_CHANNEL_CLOSE.
513 * A channel is completely finished with when we have both sent
514 * and received CLOSE.
516 * The symbolic constants below use the SSH-2 terminology, which
517 * is a bit confusing in SSH-1, but we have to use _something_.
519 #define CLOSES_SENT_EOF 1
520 #define CLOSES_SENT_CLOSE 2
521 #define CLOSES_RCVD_EOF 4
522 #define CLOSES_RCVD_CLOSE 8
526 * This flag indicates that an EOF is pending on the outgoing side
527 * of the channel: that is, wherever we're getting the data for
528 * this channel has sent us some data followed by EOF. We can't
529 * actually send the EOF until we've finished sending the data, so
530 * we set this flag instead to remind us to do so once our buffer
536 * True if this channel is causing the underlying connection to be
541 struct ssh2_data_channel {
543 unsigned remwindow, remmaxpkt;
544 /* locwindow is signed so we can cope with excess data. */
545 int locwindow, locmaxwin;
547 * remlocwin is the amount of local window that we think
548 * the remote end had available to it after it sent the
549 * last data packet or window adjust ack.
553 * These store the list of channel requests that haven't
556 struct outstanding_channel_request *chanreq_head, *chanreq_tail;
557 enum { THROTTLED, UNTHROTTLING, UNTHROTTLED } throttle_state;
561 struct ssh_agent_channel {
562 unsigned char *message;
563 unsigned char msglen[4];
564 unsigned lensofar, totallen;
565 int outstanding_requests;
567 struct ssh_x11_channel {
568 struct X11Connection *xconn;
571 struct ssh_pfd_channel {
572 struct PortForwarding *pf;
574 struct ssh_sharing_channel {
581 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
582 * use this structure in different ways, reflecting SSH-2's
583 * altogether saner approach to port forwarding.
585 * In SSH-1, you arrange a remote forwarding by sending the server
586 * the remote port number, and the local destination host:port.
587 * When a connection comes in, the server sends you back that
588 * host:port pair, and you connect to it. This is a ready-made
589 * security hole if you're not on the ball: a malicious server
590 * could send you back _any_ host:port pair, so if you trustingly
591 * connect to the address it gives you then you've just opened the
592 * entire inside of your corporate network just by connecting
593 * through it to a dodgy SSH server. Hence, we must store a list of
594 * host:port pairs we _are_ trying to forward to, and reject a
595 * connection request from the server if it's not in the list.
597 * In SSH-2, each side of the connection minds its own business and
598 * doesn't send unnecessary information to the other. You arrange a
599 * remote forwarding by sending the server just the remote port
600 * number. When a connection comes in, the server tells you which
601 * of its ports was connected to; and _you_ have to remember what
602 * local host:port pair went with that port number.
604 * Hence, in SSH-1 this structure is indexed by destination
605 * host:port pair, whereas in SSH-2 it is indexed by source port.
607 struct ssh_portfwd; /* forward declaration */
609 struct ssh_rportfwd {
610 unsigned sport, dport;
614 struct ssh_portfwd *pfrec;
617 static void free_rportfwd(struct ssh_rportfwd *pf)
620 sfree(pf->sportdesc);
628 * Separately to the rportfwd tree (which is for looking up port
629 * open requests from the server), a tree of _these_ structures is
630 * used to keep track of all the currently open port forwardings,
631 * so that we can reconfigure in mid-session if the user requests
635 enum { DESTROY, KEEP, CREATE } status;
637 unsigned sport, dport;
640 struct ssh_rportfwd *remote;
642 struct PortListener *local;
644 #define free_portfwd(pf) ( \
645 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
646 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
649 long length; /* length of packet: see below */
650 long forcepad; /* SSH-2: force padding to at least this length */
651 int type; /* only used for incoming packets */
652 unsigned long sequence; /* SSH-2 incoming sequence number */
653 unsigned char *data; /* allocated storage */
654 unsigned char *body; /* offset of payload within `data' */
655 long savedpos; /* dual-purpose saved packet position: see below */
656 long maxlen; /* amount of storage allocated for `data' */
657 long encrypted_len; /* for SSH-2 total-size counting */
660 * A note on the 'length' and 'savedpos' fields above.
662 * Incoming packets are set up so that pkt->length is measured
663 * relative to pkt->body, which itself points to a few bytes after
664 * pkt->data (skipping some uninteresting header fields including
665 * the packet type code). The ssh_pkt_get* functions all expect
666 * this setup, and they also use pkt->savedpos to indicate how far
667 * through the packet being decoded they've got - and that, too,
668 * is an offset from pkt->body rather than pkt->data.
670 * During construction of an outgoing packet, however, pkt->length
671 * is measured relative to the base pointer pkt->data, and
672 * pkt->body is not really used for anything until the packet is
673 * ready for sending. In this mode, pkt->savedpos is reused as a
674 * temporary variable by the addstring functions, which write out
675 * a string length field and then keep going back and updating it
676 * as more data is appended to the subsequent string data field;
677 * pkt->savedpos stores the offset (again relative to pkt->data)
678 * of the start of the string data field.
681 /* Extra metadata used in SSH packet logging mode, allowing us to
682 * log in the packet header line that the packet came from a
683 * connection-sharing downstream and what if anything unusual was
684 * done to it. The additional_log_text field is expected to be a
685 * static string - it will not be freed. */
686 unsigned downstream_id;
687 const char *additional_log_text;
690 static void ssh1_protocol(Ssh ssh, const void *vin, int inlen,
691 struct Packet *pktin);
692 static void ssh2_protocol(Ssh ssh, const void *vin, int inlen,
693 struct Packet *pktin);
694 static void ssh2_bare_connection_protocol(Ssh ssh, const void *vin, int inlen,
695 struct Packet *pktin);
696 static void ssh1_protocol_setup(Ssh ssh);
697 static void ssh2_protocol_setup(Ssh ssh);
698 static void ssh2_bare_connection_protocol_setup(Ssh ssh);
699 static void ssh_size(void *handle, int width, int height);
700 static void ssh_special(void *handle, Telnet_Special);
701 static int ssh2_try_send(struct ssh_channel *c);
702 static void ssh2_add_channel_data(struct ssh_channel *c,
703 const char *buf, int len);
704 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
705 static void ssh2_set_window(struct ssh_channel *c, int newwin);
706 static int ssh_sendbuffer(void *handle);
707 static int ssh_do_close(Ssh ssh, int notify_exit);
708 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
709 static int ssh2_pkt_getbool(struct Packet *pkt);
710 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
711 static void ssh2_timer(void *ctx, unsigned long now);
712 static void do_ssh2_transport(Ssh ssh, const void *vin, int inlen,
713 struct Packet *pktin);
714 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin);
716 struct rdpkt1_state_tag {
717 long len, pad, biglen, to_read;
718 unsigned long realcrc, gotcrc;
722 struct Packet *pktin;
725 struct rdpkt2_state_tag {
726 long len, pad, payload, packetlen, maclen;
729 unsigned long incoming_sequence;
730 struct Packet *pktin;
733 struct rdpkt2_bare_state_tag {
737 unsigned long incoming_sequence;
738 struct Packet *pktin;
741 struct queued_handler;
742 struct queued_handler {
744 chandler_fn_t handler;
746 struct queued_handler *next;
750 const struct plug_function_table *fn;
751 /* the above field _must_ be first in the structure */
761 unsigned char session_key[32];
763 int v1_remote_protoflags;
764 int v1_local_protoflags;
765 int agentfwd_enabled;
768 const struct ssh_cipher *cipher;
771 const struct ssh2_cipher *cscipher, *sccipher;
772 void *cs_cipher_ctx, *sc_cipher_ctx;
773 const struct ssh_mac *csmac, *scmac;
774 int csmac_etm, scmac_etm;
775 void *cs_mac_ctx, *sc_mac_ctx;
776 const struct ssh_compress *cscomp, *sccomp;
777 void *cs_comp_ctx, *sc_comp_ctx;
778 const struct ssh_kex *kex;
779 const struct ssh_signkey *hostkey;
780 char *hostkey_str; /* string representation, for easy checking in rekeys */
781 unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN];
782 int v2_session_id_len;
786 int attempting_connshare;
792 int echoing, editing;
796 int ospeed, ispeed; /* temporaries */
797 int term_width, term_height;
799 tree234 *channels; /* indexed by local id */
800 struct ssh_channel *mainchan; /* primary session channel */
801 int ncmode; /* is primary channel direct-tcpip? */
806 tree234 *rportfwds, *portfwds;
810 SSH_STATE_BEFORE_SIZE,
816 int size_needed, eof_needed;
817 int sent_console_eof;
818 int got_pty; /* affects EOF behaviour on main channel */
820 struct Packet **queue;
821 int queuelen, queuesize;
823 unsigned char *deferred_send_data;
824 int deferred_len, deferred_size;
827 * Gross hack: pscp will try to start SFTP but fall back to
828 * scp1 if that fails. This variable is the means by which
829 * scp.c can reach into the SSH code and find out which one it
834 bufchain banner; /* accumulates banners during do_ssh2_authconn */
839 struct X11Display *x11disp;
840 struct X11FakeAuth *x11auth;
841 tree234 *x11authtree;
844 int conn_throttle_count;
847 int v1_stdout_throttling;
848 unsigned long v2_outgoing_sequence;
850 int ssh1_rdpkt_crstate;
851 int ssh2_rdpkt_crstate;
852 int ssh2_bare_rdpkt_crstate;
853 int ssh_gotdata_crstate;
854 int do_ssh1_connection_crstate;
856 void *do_ssh_init_state;
857 void *do_ssh1_login_state;
858 void *do_ssh2_transport_state;
859 void *do_ssh2_authconn_state;
860 void *do_ssh_connection_init_state;
862 struct rdpkt1_state_tag rdpkt1_state;
863 struct rdpkt2_state_tag rdpkt2_state;
864 struct rdpkt2_bare_state_tag rdpkt2_bare_state;
866 /* SSH-1 and SSH-2 use this for different things, but both use it */
867 int protocol_initial_phase_done;
869 void (*protocol) (Ssh ssh, const void *vin, int inlen,
871 struct Packet *(*s_rdpkt) (Ssh ssh, const unsigned char **data,
873 int (*do_ssh_init)(Ssh ssh, unsigned char c);
876 * We maintain our own copy of a Conf structure here. That way,
877 * when we're passed a new one for reconfiguration, we can check
878 * the differences and potentially reconfigure port forwardings
879 * etc in mid-session.
884 * Values cached out of conf so as to avoid the tree234 lookup
885 * cost every time they're used.
890 * Dynamically allocated username string created during SSH
891 * login. Stored in here rather than in the coroutine state so
892 * that it'll be reliably freed if we shut down the SSH session
893 * at some unexpected moment.
898 * Used to transfer data back from async callbacks.
900 void *agent_response;
901 int agent_response_len;
905 * The SSH connection can be set as `frozen', meaning we are
906 * not currently accepting incoming data from the network. This
907 * is slightly more serious than setting the _socket_ as
908 * frozen, because we may already have had data passed to us
909 * from the network which we need to delay processing until
910 * after the freeze is lifted, so we also need a bufchain to
914 bufchain queued_incoming_data;
917 * Dispatch table for packet types that we may have to deal
920 handler_fn_t packet_dispatch[256];
923 * Queues of one-off handler functions for success/failure
924 * indications from a request.
926 struct queued_handler *qhead, *qtail;
927 handler_fn_t q_saved_handler1, q_saved_handler2;
930 * This module deals with sending keepalives.
935 * Track incoming and outgoing data sizes and time, for
938 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
939 unsigned long max_data_size;
941 unsigned long next_rekey, last_rekey;
942 const char *deferred_rekey_reason;
945 * Fully qualified host name, which we need if doing GSSAPI.
951 * GSSAPI libraries for this session.
953 struct ssh_gss_liblist *gsslibs;
957 #define logevent(s) logevent(ssh->frontend, s)
959 /* logevent, only printf-formatted. */
960 static void logeventf(Ssh ssh, const char *fmt, ...)
966 buf = dupvprintf(fmt, ap);
972 static void bomb_out(Ssh ssh, char *text)
974 ssh_do_close(ssh, FALSE);
976 connection_fatal(ssh->frontend, "%s", text);
980 #define bombout(msg) bomb_out(ssh, dupprintf msg)
982 /* Helper function for common bits of parsing ttymodes. */
983 static void parse_ttymodes(Ssh ssh,
984 void (*do_mode)(void *data, char *mode, char *val),
989 for (val = conf_get_str_strs(ssh->conf, CONF_ttymodes, NULL, &key);
991 val = conf_get_str_strs(ssh->conf, CONF_ttymodes, key, &key)) {
993 * val[0] is either 'V', indicating that an explicit value
994 * follows it, or 'A' indicating that we should pass the
995 * value through from the local environment via get_ttymode.
998 val = get_ttymode(ssh->frontend, key);
1000 do_mode(data, key, val);
1004 do_mode(data, key, val + 1); /* skip the 'V' */
1008 static int ssh_channelcmp(void *av, void *bv)
1010 struct ssh_channel *a = (struct ssh_channel *) av;
1011 struct ssh_channel *b = (struct ssh_channel *) bv;
1012 if (a->localid < b->localid)
1014 if (a->localid > b->localid)
1018 static int ssh_channelfind(void *av, void *bv)
1020 unsigned *a = (unsigned *) av;
1021 struct ssh_channel *b = (struct ssh_channel *) bv;
1022 if (*a < b->localid)
1024 if (*a > b->localid)
1029 static int ssh_rportcmp_ssh1(void *av, void *bv)
1031 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1032 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1034 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
1035 return i < 0 ? -1 : +1;
1036 if (a->dport > b->dport)
1038 if (a->dport < b->dport)
1043 static int ssh_rportcmp_ssh2(void *av, void *bv)
1045 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1046 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1048 if ( (i = strcmp(a->shost, b->shost)) != 0)
1049 return i < 0 ? -1 : +1;
1050 if (a->sport > b->sport)
1052 if (a->sport < b->sport)
1058 * Special form of strcmp which can cope with NULL inputs. NULL is
1059 * defined to sort before even the empty string.
1061 static int nullstrcmp(const char *a, const char *b)
1063 if (a == NULL && b == NULL)
1069 return strcmp(a, b);
1072 static int ssh_portcmp(void *av, void *bv)
1074 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
1075 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
1077 if (a->type > b->type)
1079 if (a->type < b->type)
1081 if (a->addressfamily > b->addressfamily)
1083 if (a->addressfamily < b->addressfamily)
1085 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
1086 return i < 0 ? -1 : +1;
1087 if (a->sport > b->sport)
1089 if (a->sport < b->sport)
1091 if (a->type != 'D') {
1092 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
1093 return i < 0 ? -1 : +1;
1094 if (a->dport > b->dport)
1096 if (a->dport < b->dport)
1102 static int alloc_channel_id(Ssh ssh)
1104 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1105 unsigned low, high, mid;
1107 struct ssh_channel *c;
1110 * First-fit allocation of channel numbers: always pick the
1111 * lowest unused one. To do this, binary-search using the
1112 * counted B-tree to find the largest channel ID which is in a
1113 * contiguous sequence from the beginning. (Precisely
1114 * everything in that sequence must have ID equal to its tree
1115 * index plus CHANNEL_NUMBER_OFFSET.)
1117 tsize = count234(ssh->channels);
1121 while (high - low > 1) {
1122 mid = (high + low) / 2;
1123 c = index234(ssh->channels, mid);
1124 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1125 low = mid; /* this one is fine */
1127 high = mid; /* this one is past it */
1130 * Now low points to either -1, or the tree index of the
1131 * largest ID in the initial sequence.
1134 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
1135 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
1137 return low + 1 + CHANNEL_NUMBER_OFFSET;
1140 static void c_write_stderr(int trusted, const char *buf, int len)
1143 for (i = 0; i < len; i++)
1144 if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60)))
1145 fputc(buf[i], stderr);
1148 static void c_write(Ssh ssh, const char *buf, int len)
1150 if (flags & FLAG_STDERR)
1151 c_write_stderr(1, buf, len);
1153 from_backend(ssh->frontend, 1, buf, len);
1156 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
1158 if (flags & FLAG_STDERR)
1159 c_write_stderr(0, buf, len);
1161 from_backend_untrusted(ssh->frontend, buf, len);
1164 static void c_write_str(Ssh ssh, const char *buf)
1166 c_write(ssh, buf, strlen(buf));
1169 static void ssh_free_packet(struct Packet *pkt)
1174 static struct Packet *ssh_new_packet(void)
1176 struct Packet *pkt = snew(struct Packet);
1178 pkt->body = pkt->data = NULL;
1184 static void ssh1_log_incoming_packet(Ssh ssh, struct Packet *pkt)
1187 struct logblank_t blanks[4];
1193 if (ssh->logomitdata &&
1194 (pkt->type == SSH1_SMSG_STDOUT_DATA ||
1195 pkt->type == SSH1_SMSG_STDERR_DATA ||
1196 pkt->type == SSH1_MSG_CHANNEL_DATA)) {
1197 /* "Session data" packets - omit the data string. */
1198 if (pkt->type == SSH1_MSG_CHANNEL_DATA)
1199 ssh_pkt_getuint32(pkt); /* skip channel id */
1200 blanks[nblanks].offset = pkt->savedpos + 4;
1201 blanks[nblanks].type = PKTLOG_OMIT;
1202 ssh_pkt_getstring(pkt, &str, &slen);
1204 blanks[nblanks].len = slen;
1208 log_packet(ssh->logctx, PKT_INCOMING, pkt->type,
1209 ssh1_pkt_type(pkt->type),
1210 pkt->body, pkt->length, nblanks, blanks, NULL,
1214 static void ssh1_log_outgoing_packet(Ssh ssh, struct Packet *pkt)
1217 struct logblank_t blanks[4];
1222 * For outgoing packets, pkt->length represents the length of the
1223 * whole packet starting at pkt->data (including some header), and
1224 * pkt->body refers to the point within that where the log-worthy
1225 * payload begins. However, incoming packets expect pkt->length to
1226 * represent only the payload length (that is, it's measured from
1227 * pkt->body not from pkt->data). Temporarily adjust our outgoing
1228 * packet to conform to the incoming-packet semantics, so that we
1229 * can analyse it with the ssh_pkt_get functions.
1231 pkt->length -= (pkt->body - pkt->data);
1234 if (ssh->logomitdata &&
1235 (pkt->type == SSH1_CMSG_STDIN_DATA ||
1236 pkt->type == SSH1_MSG_CHANNEL_DATA)) {
1237 /* "Session data" packets - omit the data string. */
1238 if (pkt->type == SSH1_MSG_CHANNEL_DATA)
1239 ssh_pkt_getuint32(pkt); /* skip channel id */
1240 blanks[nblanks].offset = pkt->savedpos + 4;
1241 blanks[nblanks].type = PKTLOG_OMIT;
1242 ssh_pkt_getstring(pkt, &str, &slen);
1244 blanks[nblanks].len = slen;
1249 if ((pkt->type == SSH1_CMSG_AUTH_PASSWORD ||
1250 pkt->type == SSH1_CMSG_AUTH_TIS_RESPONSE ||
1251 pkt->type == SSH1_CMSG_AUTH_CCARD_RESPONSE) &&
1252 conf_get_int(ssh->conf, CONF_logomitpass)) {
1253 /* If this is a password or similar packet, blank the password(s). */
1254 blanks[nblanks].offset = 0;
1255 blanks[nblanks].len = pkt->length;
1256 blanks[nblanks].type = PKTLOG_BLANK;
1258 } else if (pkt->type == SSH1_CMSG_X11_REQUEST_FORWARDING &&
1259 conf_get_int(ssh->conf, CONF_logomitpass)) {
1261 * If this is an X forwarding request packet, blank the fake
1264 * Note that while we blank the X authentication data here, we
1265 * don't take any special action to blank the start of an X11
1266 * channel, so using MIT-MAGIC-COOKIE-1 and actually opening
1267 * an X connection without having session blanking enabled is
1268 * likely to leak your cookie into the log.
1271 ssh_pkt_getstring(pkt, &str, &slen);
1272 blanks[nblanks].offset = pkt->savedpos;
1273 blanks[nblanks].type = PKTLOG_BLANK;
1274 ssh_pkt_getstring(pkt, &str, &slen);
1276 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1281 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1282 ssh1_pkt_type(pkt->data[12]),
1283 pkt->body, pkt->length,
1284 nblanks, blanks, NULL, 0, NULL);
1287 * Undo the above adjustment of pkt->length, to put the packet
1288 * back in the state we found it.
1290 pkt->length += (pkt->body - pkt->data);
1294 * Collect incoming data in the incoming packet buffer.
1295 * Decipher and verify the packet when it is completely read.
1296 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1297 * Update the *data and *datalen variables.
1298 * Return a Packet structure when a packet is completed.
1300 static struct Packet *ssh1_rdpkt(Ssh ssh, const unsigned char **data,
1303 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
1305 crBegin(ssh->ssh1_rdpkt_crstate);
1307 st->pktin = ssh_new_packet();
1309 st->pktin->type = 0;
1310 st->pktin->length = 0;
1312 for (st->i = st->len = 0; st->i < 4; st->i++) {
1313 while ((*datalen) == 0)
1315 st->len = (st->len << 8) + **data;
1316 (*data)++, (*datalen)--;
1319 st->pad = 8 - (st->len % 8);
1320 st->biglen = st->len + st->pad;
1321 st->pktin->length = st->len - 5;
1323 if (st->biglen < 0) {
1324 bombout(("Extremely large packet length from server suggests"
1325 " data stream corruption"));
1326 ssh_free_packet(st->pktin);
1330 st->pktin->maxlen = st->biglen;
1331 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1333 st->to_read = st->biglen;
1334 st->p = st->pktin->data;
1335 while (st->to_read > 0) {
1336 st->chunk = st->to_read;
1337 while ((*datalen) == 0)
1339 if (st->chunk > (*datalen))
1340 st->chunk = (*datalen);
1341 memcpy(st->p, *data, st->chunk);
1343 *datalen -= st->chunk;
1345 st->to_read -= st->chunk;
1348 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1349 st->biglen, NULL)) {
1350 bombout(("Network attack (CRC compensation) detected!"));
1351 ssh_free_packet(st->pktin);
1356 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1358 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1359 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1360 if (st->gotcrc != st->realcrc) {
1361 bombout(("Incorrect CRC received on packet"));
1362 ssh_free_packet(st->pktin);
1366 st->pktin->body = st->pktin->data + st->pad + 1;
1368 if (ssh->v1_compressing) {
1369 unsigned char *decompblk;
1371 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1372 st->pktin->body - 1, st->pktin->length + 1,
1373 &decompblk, &decomplen)) {
1374 bombout(("Zlib decompression encountered invalid data"));
1375 ssh_free_packet(st->pktin);
1379 if (st->pktin->maxlen < st->pad + decomplen) {
1380 st->pktin->maxlen = st->pad + decomplen;
1381 st->pktin->data = sresize(st->pktin->data,
1382 st->pktin->maxlen + APIEXTRA,
1384 st->pktin->body = st->pktin->data + st->pad + 1;
1387 memcpy(st->pktin->body - 1, decompblk, decomplen);
1389 st->pktin->length = decomplen - 1;
1392 st->pktin->type = st->pktin->body[-1];
1395 * Now pktin->body and pktin->length identify the semantic content
1396 * of the packet, excluding the initial type byte.
1400 ssh1_log_incoming_packet(ssh, st->pktin);
1402 st->pktin->savedpos = 0;
1404 crFinish(st->pktin);
1407 static void ssh2_log_incoming_packet(Ssh ssh, struct Packet *pkt)
1410 struct logblank_t blanks[4];
1416 if (ssh->logomitdata &&
1417 (pkt->type == SSH2_MSG_CHANNEL_DATA ||
1418 pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)) {
1419 /* "Session data" packets - omit the data string. */
1420 ssh_pkt_getuint32(pkt); /* skip channel id */
1421 if (pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)
1422 ssh_pkt_getuint32(pkt); /* skip extended data type */
1423 blanks[nblanks].offset = pkt->savedpos + 4;
1424 blanks[nblanks].type = PKTLOG_OMIT;
1425 ssh_pkt_getstring(pkt, &str, &slen);
1427 blanks[nblanks].len = slen;
1432 log_packet(ssh->logctx, PKT_INCOMING, pkt->type,
1433 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->type),
1434 pkt->body, pkt->length, nblanks, blanks, &pkt->sequence,
1438 static void ssh2_log_outgoing_packet(Ssh ssh, struct Packet *pkt)
1441 struct logblank_t blanks[4];
1446 * For outgoing packets, pkt->length represents the length of the
1447 * whole packet starting at pkt->data (including some header), and
1448 * pkt->body refers to the point within that where the log-worthy
1449 * payload begins. However, incoming packets expect pkt->length to
1450 * represent only the payload length (that is, it's measured from
1451 * pkt->body not from pkt->data). Temporarily adjust our outgoing
1452 * packet to conform to the incoming-packet semantics, so that we
1453 * can analyse it with the ssh_pkt_get functions.
1455 pkt->length -= (pkt->body - pkt->data);
1458 if (ssh->logomitdata &&
1459 (pkt->type == SSH2_MSG_CHANNEL_DATA ||
1460 pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)) {
1461 /* "Session data" packets - omit the data string. */
1462 ssh_pkt_getuint32(pkt); /* skip channel id */
1463 if (pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)
1464 ssh_pkt_getuint32(pkt); /* skip extended data type */
1465 blanks[nblanks].offset = pkt->savedpos + 4;
1466 blanks[nblanks].type = PKTLOG_OMIT;
1467 ssh_pkt_getstring(pkt, &str, &slen);
1469 blanks[nblanks].len = slen;
1474 if (pkt->type == SSH2_MSG_USERAUTH_REQUEST &&
1475 conf_get_int(ssh->conf, CONF_logomitpass)) {
1476 /* If this is a password packet, blank the password(s). */
1478 ssh_pkt_getstring(pkt, &str, &slen);
1479 ssh_pkt_getstring(pkt, &str, &slen);
1480 ssh_pkt_getstring(pkt, &str, &slen);
1481 if (slen == 8 && !memcmp(str, "password", 8)) {
1482 ssh2_pkt_getbool(pkt);
1483 /* Blank the password field. */
1484 blanks[nblanks].offset = pkt->savedpos;
1485 blanks[nblanks].type = PKTLOG_BLANK;
1486 ssh_pkt_getstring(pkt, &str, &slen);
1488 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1490 /* If there's another password field beyond it (change of
1491 * password), blank that too. */
1492 ssh_pkt_getstring(pkt, &str, &slen);
1494 blanks[nblanks-1].len =
1495 pkt->savedpos - blanks[nblanks].offset;
1498 } else if (ssh->pkt_actx == SSH2_PKTCTX_KBDINTER &&
1499 pkt->type == SSH2_MSG_USERAUTH_INFO_RESPONSE &&
1500 conf_get_int(ssh->conf, CONF_logomitpass)) {
1501 /* If this is a keyboard-interactive response packet, blank
1504 ssh_pkt_getuint32(pkt);
1505 blanks[nblanks].offset = pkt->savedpos;
1506 blanks[nblanks].type = PKTLOG_BLANK;
1508 ssh_pkt_getstring(pkt, &str, &slen);
1512 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1514 } else if (pkt->type == SSH2_MSG_CHANNEL_REQUEST &&
1515 conf_get_int(ssh->conf, CONF_logomitpass)) {
1517 * If this is an X forwarding request packet, blank the fake
1520 * Note that while we blank the X authentication data here, we
1521 * don't take any special action to blank the start of an X11
1522 * channel, so using MIT-MAGIC-COOKIE-1 and actually opening
1523 * an X connection without having session blanking enabled is
1524 * likely to leak your cookie into the log.
1527 ssh_pkt_getuint32(pkt);
1528 ssh_pkt_getstring(pkt, &str, &slen);
1529 if (slen == 7 && !memcmp(str, "x11-req", 0)) {
1530 ssh2_pkt_getbool(pkt);
1531 ssh2_pkt_getbool(pkt);
1532 ssh_pkt_getstring(pkt, &str, &slen);
1533 blanks[nblanks].offset = pkt->savedpos;
1534 blanks[nblanks].type = PKTLOG_BLANK;
1535 ssh_pkt_getstring(pkt, &str, &slen);
1537 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1543 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1544 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]),
1545 pkt->body, pkt->length, nblanks, blanks,
1546 &ssh->v2_outgoing_sequence,
1547 pkt->downstream_id, pkt->additional_log_text);
1550 * Undo the above adjustment of pkt->length, to put the packet
1551 * back in the state we found it.
1553 pkt->length += (pkt->body - pkt->data);
1556 static struct Packet *ssh2_rdpkt(Ssh ssh, const unsigned char **data,
1559 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1561 crBegin(ssh->ssh2_rdpkt_crstate);
1563 st->pktin = ssh_new_packet();
1565 st->pktin->type = 0;
1566 st->pktin->length = 0;
1568 st->cipherblk = ssh->sccipher->blksize;
1571 if (st->cipherblk < 8)
1573 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1575 if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_IS_CBC) &&
1576 ssh->scmac && !ssh->scmac_etm) {
1578 * When dealing with a CBC-mode cipher, we want to avoid the
1579 * possibility of an attacker's tweaking the ciphertext stream
1580 * so as to cause us to feed the same block to the block
1581 * cipher more than once and thus leak information
1582 * (VU#958563). The way we do this is not to take any
1583 * decisions on the basis of anything we've decrypted until
1584 * we've verified it with a MAC. That includes the packet
1585 * length, so we just read data and check the MAC repeatedly,
1586 * and when the MAC passes, see if the length we've got is
1589 * This defence is unnecessary in OpenSSH ETM mode, because
1590 * the whole point of ETM mode is that the attacker can't
1591 * tweak the ciphertext stream at all without the MAC
1592 * detecting it before we decrypt anything.
1595 /* May as well allocate the whole lot now. */
1596 st->pktin->data = snewn(OUR_V2_PACKETLIMIT + st->maclen + APIEXTRA,
1599 /* Read an amount corresponding to the MAC. */
1600 for (st->i = 0; st->i < st->maclen; st->i++) {
1601 while ((*datalen) == 0)
1603 st->pktin->data[st->i] = *(*data)++;
1609 unsigned char seq[4];
1610 ssh->scmac->start(ssh->sc_mac_ctx);
1611 PUT_32BIT(seq, st->incoming_sequence);
1612 ssh->scmac->bytes(ssh->sc_mac_ctx, seq, 4);
1615 for (;;) { /* Once around this loop per cipher block. */
1616 /* Read another cipher-block's worth, and tack it onto the end. */
1617 for (st->i = 0; st->i < st->cipherblk; st->i++) {
1618 while ((*datalen) == 0)
1620 st->pktin->data[st->packetlen+st->maclen+st->i] = *(*data)++;
1623 /* Decrypt one more block (a little further back in the stream). */
1624 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1625 st->pktin->data + st->packetlen,
1627 /* Feed that block to the MAC. */
1628 ssh->scmac->bytes(ssh->sc_mac_ctx,
1629 st->pktin->data + st->packetlen, st->cipherblk);
1630 st->packetlen += st->cipherblk;
1631 /* See if that gives us a valid packet. */
1632 if (ssh->scmac->verresult(ssh->sc_mac_ctx,
1633 st->pktin->data + st->packetlen) &&
1634 ((st->len = toint(GET_32BIT(st->pktin->data))) ==
1637 if (st->packetlen >= OUR_V2_PACKETLIMIT) {
1638 bombout(("No valid incoming packet found"));
1639 ssh_free_packet(st->pktin);
1643 st->pktin->maxlen = st->packetlen + st->maclen;
1644 st->pktin->data = sresize(st->pktin->data,
1645 st->pktin->maxlen + APIEXTRA,
1647 } else if (ssh->scmac && ssh->scmac_etm) {
1648 st->pktin->data = snewn(4 + APIEXTRA, unsigned char);
1651 * OpenSSH encrypt-then-MAC mode: the packet length is
1652 * unencrypted, unless the cipher supports length encryption.
1654 for (st->i = st->len = 0; st->i < 4; st->i++) {
1655 while ((*datalen) == 0)
1657 st->pktin->data[st->i] = *(*data)++;
1660 /* Cipher supports length decryption, so do it */
1661 if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_SEPARATE_LENGTH)) {
1662 /* Keep the packet the same though, so the MAC passes */
1663 unsigned char len[4];
1664 memcpy(len, st->pktin->data, 4);
1665 ssh->sccipher->decrypt_length(ssh->sc_cipher_ctx, len, 4, st->incoming_sequence);
1666 st->len = toint(GET_32BIT(len));
1668 st->len = toint(GET_32BIT(st->pktin->data));
1672 * _Completely_ silly lengths should be stomped on before they
1673 * do us any more damage.
1675 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1676 st->len % st->cipherblk != 0) {
1677 bombout(("Incoming packet length field was garbled"));
1678 ssh_free_packet(st->pktin);
1683 * So now we can work out the total packet length.
1685 st->packetlen = st->len + 4;
1688 * Allocate memory for the rest of the packet.
1690 st->pktin->maxlen = st->packetlen + st->maclen;
1691 st->pktin->data = sresize(st->pktin->data,
1692 st->pktin->maxlen + APIEXTRA,
1696 * Read the remainder of the packet.
1698 for (st->i = 4; st->i < st->packetlen + st->maclen; st->i++) {
1699 while ((*datalen) == 0)
1701 st->pktin->data[st->i] = *(*data)++;
1709 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1710 st->len + 4, st->incoming_sequence)) {
1711 bombout(("Incorrect MAC received on packet"));
1712 ssh_free_packet(st->pktin);
1716 /* Decrypt everything between the length field and the MAC. */
1718 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1719 st->pktin->data + 4,
1722 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1725 * Acquire and decrypt the first block of the packet. This will
1726 * contain the length and padding details.
1728 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1729 while ((*datalen) == 0)
1731 st->pktin->data[st->i] = *(*data)++;
1736 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1737 st->pktin->data, st->cipherblk);
1740 * Now get the length figure.
1742 st->len = toint(GET_32BIT(st->pktin->data));
1745 * _Completely_ silly lengths should be stomped on before they
1746 * do us any more damage.
1748 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1749 (st->len + 4) % st->cipherblk != 0) {
1750 bombout(("Incoming packet was garbled on decryption"));
1751 ssh_free_packet(st->pktin);
1756 * So now we can work out the total packet length.
1758 st->packetlen = st->len + 4;
1761 * Allocate memory for the rest of the packet.
1763 st->pktin->maxlen = st->packetlen + st->maclen;
1764 st->pktin->data = sresize(st->pktin->data,
1765 st->pktin->maxlen + APIEXTRA,
1769 * Read and decrypt the remainder of the packet.
1771 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1773 while ((*datalen) == 0)
1775 st->pktin->data[st->i] = *(*data)++;
1778 /* Decrypt everything _except_ the MAC. */
1780 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1781 st->pktin->data + st->cipherblk,
1782 st->packetlen - st->cipherblk);
1788 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1789 st->len + 4, st->incoming_sequence)) {
1790 bombout(("Incorrect MAC received on packet"));
1791 ssh_free_packet(st->pktin);
1795 /* Get and sanity-check the amount of random padding. */
1796 st->pad = st->pktin->data[4];
1797 if (st->pad < 4 || st->len - st->pad < 1) {
1798 bombout(("Invalid padding length on received packet"));
1799 ssh_free_packet(st->pktin);
1803 * This enables us to deduce the payload length.
1805 st->payload = st->len - st->pad - 1;
1807 st->pktin->length = st->payload + 5;
1808 st->pktin->encrypted_len = st->packetlen;
1810 st->pktin->sequence = st->incoming_sequence++;
1812 st->pktin->length = st->packetlen - st->pad;
1813 assert(st->pktin->length >= 0);
1816 * Decompress packet payload.
1819 unsigned char *newpayload;
1822 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1823 st->pktin->data + 5, st->pktin->length - 5,
1824 &newpayload, &newlen)) {
1825 if (st->pktin->maxlen < newlen + 5) {
1826 st->pktin->maxlen = newlen + 5;
1827 st->pktin->data = sresize(st->pktin->data,
1828 st->pktin->maxlen + APIEXTRA,
1831 st->pktin->length = 5 + newlen;
1832 memcpy(st->pktin->data + 5, newpayload, newlen);
1838 * pktin->body and pktin->length should identify the semantic
1839 * content of the packet, excluding the initial type byte.
1841 st->pktin->type = st->pktin->data[5];
1842 st->pktin->body = st->pktin->data + 6;
1843 st->pktin->length -= 6;
1844 assert(st->pktin->length >= 0); /* one last double-check */
1847 ssh2_log_incoming_packet(ssh, st->pktin);
1849 st->pktin->savedpos = 0;
1851 crFinish(st->pktin);
1854 static struct Packet *ssh2_bare_connection_rdpkt(Ssh ssh,
1855 const unsigned char **data,
1858 struct rdpkt2_bare_state_tag *st = &ssh->rdpkt2_bare_state;
1860 crBegin(ssh->ssh2_bare_rdpkt_crstate);
1863 * Read the packet length field.
1865 for (st->i = 0; st->i < 4; st->i++) {
1866 while ((*datalen) == 0)
1868 st->length[st->i] = *(*data)++;
1872 st->packetlen = toint(GET_32BIT_MSB_FIRST(st->length));
1873 if (st->packetlen <= 0 || st->packetlen >= OUR_V2_PACKETLIMIT) {
1874 bombout(("Invalid packet length received"));
1878 st->pktin = ssh_new_packet();
1879 st->pktin->data = snewn(st->packetlen, unsigned char);
1881 st->pktin->encrypted_len = st->packetlen;
1883 st->pktin->sequence = st->incoming_sequence++;
1886 * Read the remainder of the packet.
1888 for (st->i = 0; st->i < st->packetlen; st->i++) {
1889 while ((*datalen) == 0)
1891 st->pktin->data[st->i] = *(*data)++;
1896 * pktin->body and pktin->length should identify the semantic
1897 * content of the packet, excluding the initial type byte.
1899 st->pktin->type = st->pktin->data[0];
1900 st->pktin->body = st->pktin->data + 1;
1901 st->pktin->length = st->packetlen - 1;
1904 * Log incoming packet, possibly omitting sensitive fields.
1907 ssh2_log_incoming_packet(ssh, st->pktin);
1909 st->pktin->savedpos = 0;
1911 crFinish(st->pktin);
1914 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1916 int pad, biglen, i, pktoffs;
1920 * XXX various versions of SC (including 8.8.4) screw up the
1921 * register allocation in this function and use the same register
1922 * (D6) for len and as a temporary, with predictable results. The
1923 * following sledgehammer prevents this.
1930 ssh1_log_outgoing_packet(ssh, pkt);
1932 if (ssh->v1_compressing) {
1933 unsigned char *compblk;
1935 zlib_compress_block(ssh->cs_comp_ctx,
1936 pkt->data + 12, pkt->length - 12,
1937 &compblk, &complen);
1938 ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */
1939 memcpy(pkt->data + 12, compblk, complen);
1941 pkt->length = complen + 12;
1944 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1946 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
1947 pad = 8 - (len % 8);
1949 biglen = len + pad; /* len(padding+type+data+CRC) */
1951 for (i = pktoffs; i < 4+8; i++)
1952 pkt->data[i] = random_byte();
1953 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1954 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1955 PUT_32BIT(pkt->data + pktoffs, len);
1958 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1959 pkt->data + pktoffs + 4, biglen);
1961 if (offset_p) *offset_p = pktoffs;
1962 return biglen + 4; /* len(length+padding+type+data+CRC) */
1965 static int s_write(Ssh ssh, void *data, int len)
1968 log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len,
1969 0, NULL, NULL, 0, NULL);
1972 return sk_write(ssh->s, (char *)data, len);
1975 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1977 int len, backlog, offset;
1978 len = s_wrpkt_prepare(ssh, pkt, &offset);
1979 backlog = s_write(ssh, pkt->data + offset, len);
1980 if (backlog > SSH_MAX_BACKLOG)
1981 ssh_throttle_all(ssh, 1, backlog);
1982 ssh_free_packet(pkt);
1985 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1988 len = s_wrpkt_prepare(ssh, pkt, &offset);
1989 if (ssh->deferred_len + len > ssh->deferred_size) {
1990 ssh->deferred_size = ssh->deferred_len + len + 128;
1991 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1995 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1996 pkt->data + offset, len);
1997 ssh->deferred_len += len;
1998 ssh_free_packet(pkt);
2002 * Construct a SSH-1 packet with the specified contents.
2003 * (This all-at-once interface used to be the only one, but now SSH-1
2004 * packets can also be constructed incrementally.)
2006 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
2012 pkt = ssh1_pkt_init(pkttype);
2014 while ((argtype = va_arg(ap, int)) != PKT_END) {
2015 unsigned char *argp, argchar;
2017 unsigned long argint;
2020 /* Actual fields in the packet */
2022 argint = va_arg(ap, int);
2023 ssh_pkt_adduint32(pkt, argint);
2026 argchar = (unsigned char) va_arg(ap, int);
2027 ssh_pkt_addbyte(pkt, argchar);
2030 argp = va_arg(ap, unsigned char *);
2031 arglen = va_arg(ap, int);
2032 ssh_pkt_adddata(pkt, argp, arglen);
2035 sargp = va_arg(ap, char *);
2036 ssh_pkt_addstring(pkt, sargp);
2039 bn = va_arg(ap, Bignum);
2040 ssh1_pkt_addmp(pkt, bn);
2048 static void send_packet(Ssh ssh, int pkttype, ...)
2052 va_start(ap, pkttype);
2053 pkt = construct_packet(ssh, pkttype, ap);
2058 static void defer_packet(Ssh ssh, int pkttype, ...)
2062 va_start(ap, pkttype);
2063 pkt = construct_packet(ssh, pkttype, ap);
2065 s_wrpkt_defer(ssh, pkt);
2068 static int ssh_versioncmp(const char *a, const char *b)
2071 unsigned long av, bv;
2073 av = strtoul(a, &ae, 10);
2074 bv = strtoul(b, &be, 10);
2076 return (av < bv ? -1 : +1);
2081 av = strtoul(ae, &ae, 10);
2082 bv = strtoul(be, &be, 10);
2084 return (av < bv ? -1 : +1);
2089 * Utility routines for putting an SSH-protocol `string' and
2090 * `uint32' into a hash state.
2092 static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
2094 unsigned char lenblk[4];
2095 PUT_32BIT(lenblk, len);
2096 h->bytes(s, lenblk, 4);
2097 h->bytes(s, str, len);
2100 static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
2102 unsigned char intblk[4];
2103 PUT_32BIT(intblk, i);
2104 h->bytes(s, intblk, 4);
2108 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
2110 static void ssh_pkt_ensure(struct Packet *pkt, int length)
2112 if (pkt->maxlen < length) {
2113 unsigned char *body = pkt->body;
2114 int offset = body ? body - pkt->data : 0;
2115 pkt->maxlen = length + 256;
2116 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
2117 if (body) pkt->body = pkt->data + offset;
2120 static void ssh_pkt_adddata(struct Packet *pkt, const void *data, int len)
2123 ssh_pkt_ensure(pkt, pkt->length);
2124 memcpy(pkt->data + pkt->length - len, data, len);
2126 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
2128 ssh_pkt_adddata(pkt, &byte, 1);
2130 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
2132 ssh_pkt_adddata(pkt, &value, 1);
2134 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
2137 PUT_32BIT(x, value);
2138 ssh_pkt_adddata(pkt, x, 4);
2140 static void ssh_pkt_addstring_start(struct Packet *pkt)
2142 ssh_pkt_adduint32(pkt, 0);
2143 pkt->savedpos = pkt->length;
2145 static void ssh_pkt_addstring_data(struct Packet *pkt, const char *data,
2148 ssh_pkt_adddata(pkt, data, len);
2149 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
2151 static void ssh_pkt_addstring_str(struct Packet *pkt, const char *data)
2153 ssh_pkt_addstring_data(pkt, data, strlen(data));
2155 static void ssh_pkt_addstring(struct Packet *pkt, const char *data)
2157 ssh_pkt_addstring_start(pkt);
2158 ssh_pkt_addstring_str(pkt, data);
2160 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
2162 int len = ssh1_bignum_length(b);
2163 unsigned char *data = snewn(len, unsigned char);
2164 (void) ssh1_write_bignum(data, b);
2165 ssh_pkt_adddata(pkt, data, len);
2168 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
2171 int i, n = (bignum_bitcount(b) + 7) / 8;
2172 p = snewn(n + 1, unsigned char);
2174 for (i = 1; i <= n; i++)
2175 p[i] = bignum_byte(b, n - i);
2177 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
2179 memmove(p, p + i, n + 1 - i);
2183 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
2187 p = ssh2_mpint_fmt(b, &len);
2188 ssh_pkt_addstring_start(pkt);
2189 ssh_pkt_addstring_data(pkt, (char *)p, len);
2193 static struct Packet *ssh1_pkt_init(int pkt_type)
2195 struct Packet *pkt = ssh_new_packet();
2196 pkt->length = 4 + 8; /* space for length + max padding */
2197 ssh_pkt_addbyte(pkt, pkt_type);
2198 pkt->body = pkt->data + pkt->length;
2199 pkt->type = pkt_type;
2200 pkt->downstream_id = 0;
2201 pkt->additional_log_text = NULL;
2205 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
2206 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
2207 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
2208 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
2209 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
2210 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
2211 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
2212 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
2213 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
2215 static struct Packet *ssh2_pkt_init(int pkt_type)
2217 struct Packet *pkt = ssh_new_packet();
2218 pkt->length = 5; /* space for packet length + padding length */
2220 pkt->type = pkt_type;
2221 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
2222 pkt->body = pkt->data + pkt->length; /* after packet type */
2223 pkt->downstream_id = 0;
2224 pkt->additional_log_text = NULL;
2229 * Construct an SSH-2 final-form packet: compress it, encrypt it,
2230 * put the MAC on it. Final packet, ready to be sent, is stored in
2231 * pkt->data. Total length is returned.
2233 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
2235 int cipherblk, maclen, padding, unencrypted_prefix, i;
2238 ssh2_log_outgoing_packet(ssh, pkt);
2240 if (ssh->bare_connection) {
2242 * Trivial packet construction for the bare connection
2245 PUT_32BIT(pkt->data + 1, pkt->length - 5);
2246 pkt->body = pkt->data + 1;
2247 ssh->v2_outgoing_sequence++; /* only for diagnostics, really */
2248 return pkt->length - 1;
2252 * Compress packet payload.
2255 unsigned char *newpayload;
2258 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
2260 &newpayload, &newlen)) {
2262 ssh2_pkt_adddata(pkt, newpayload, newlen);
2268 * Add padding. At least four bytes, and must also bring total
2269 * length (minus MAC) up to a multiple of the block size.
2270 * If pkt->forcepad is set, make sure the packet is at least that size
2273 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
2274 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
2276 unencrypted_prefix = (ssh->csmac && ssh->csmac_etm) ? 4 : 0;
2277 if (pkt->length + padding < pkt->forcepad)
2278 padding = pkt->forcepad - pkt->length;
2280 (cipherblk - (pkt->length - unencrypted_prefix + padding) % cipherblk)
2282 assert(padding <= 255);
2283 maclen = ssh->csmac ? ssh->csmac->len : 0;
2284 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
2285 pkt->data[4] = padding;
2286 for (i = 0; i < padding; i++)
2287 pkt->data[pkt->length + i] = random_byte();
2288 PUT_32BIT(pkt->data, pkt->length + padding - 4);
2290 /* Encrypt length if the scheme requires it */
2291 if (ssh->cscipher && (ssh->cscipher->flags & SSH_CIPHER_SEPARATE_LENGTH)) {
2292 ssh->cscipher->encrypt_length(ssh->cs_cipher_ctx, pkt->data, 4,
2293 ssh->v2_outgoing_sequence);
2296 if (ssh->csmac && ssh->csmac_etm) {
2298 * OpenSSH-defined encrypt-then-MAC protocol.
2301 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
2302 pkt->data + 4, pkt->length + padding - 4);
2303 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
2304 pkt->length + padding,
2305 ssh->v2_outgoing_sequence);
2308 * SSH-2 standard protocol.
2311 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
2312 pkt->length + padding,
2313 ssh->v2_outgoing_sequence);
2315 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
2316 pkt->data, pkt->length + padding);
2319 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
2320 pkt->encrypted_len = pkt->length + padding;
2322 /* Ready-to-send packet starts at pkt->data. We return length. */
2323 pkt->body = pkt->data;
2324 return pkt->length + padding + maclen;
2328 * Routines called from the main SSH code to send packets. There
2329 * are quite a few of these, because we have two separate
2330 * mechanisms for delaying the sending of packets:
2332 * - In order to send an IGNORE message and a password message in
2333 * a single fixed-length blob, we require the ability to
2334 * concatenate the encrypted forms of those two packets _into_ a
2335 * single blob and then pass it to our <network.h> transport
2336 * layer in one go. Hence, there's a deferment mechanism which
2337 * works after packet encryption.
2339 * - In order to avoid sending any connection-layer messages
2340 * during repeat key exchange, we have to queue up any such
2341 * outgoing messages _before_ they are encrypted (and in
2342 * particular before they're allocated sequence numbers), and
2343 * then send them once we've finished.
2345 * I call these mechanisms `defer' and `queue' respectively, so as
2346 * to distinguish them reasonably easily.
2348 * The functions send_noqueue() and defer_noqueue() free the packet
2349 * structure they are passed. Every outgoing packet goes through
2350 * precisely one of these functions in its life; packets passed to
2351 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
2352 * these or get queued, and then when the queue is later emptied
2353 * the packets are all passed to defer_noqueue().
2355 * When using a CBC-mode cipher, it's necessary to ensure that an
2356 * attacker can't provide data to be encrypted using an IV that they
2357 * know. We ensure this by prefixing each packet that might contain
2358 * user data with an SSH_MSG_IGNORE. This is done using the deferral
2359 * mechanism, so in this case send_noqueue() ends up redirecting to
2360 * defer_noqueue(). If you don't like this inefficiency, don't use
2364 static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
2365 static void ssh_pkt_defersend(Ssh);
2368 * Send an SSH-2 packet immediately, without queuing or deferring.
2370 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
2374 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
2375 /* We need to send two packets, so use the deferral mechanism. */
2376 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2377 ssh_pkt_defersend(ssh);
2380 len = ssh2_pkt_construct(ssh, pkt);
2381 backlog = s_write(ssh, pkt->body, len);
2382 if (backlog > SSH_MAX_BACKLOG)
2383 ssh_throttle_all(ssh, 1, backlog);
2385 ssh->outgoing_data_size += pkt->encrypted_len;
2386 if (!ssh->kex_in_progress &&
2387 !ssh->bare_connection &&
2388 ssh->max_data_size != 0 &&
2389 ssh->outgoing_data_size > ssh->max_data_size)
2390 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2392 ssh_free_packet(pkt);
2396 * Defer an SSH-2 packet.
2398 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
2401 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
2402 ssh->deferred_len == 0 && !noignore &&
2403 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2405 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2406 * get encrypted with a known IV.
2408 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2409 ssh2_pkt_addstring_start(ipkt);
2410 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
2412 len = ssh2_pkt_construct(ssh, pkt);
2413 if (ssh->deferred_len + len > ssh->deferred_size) {
2414 ssh->deferred_size = ssh->deferred_len + len + 128;
2415 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2419 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->body, len);
2420 ssh->deferred_len += len;
2421 ssh->deferred_data_size += pkt->encrypted_len;
2422 ssh_free_packet(pkt);
2426 * Queue an SSH-2 packet.
2428 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
2430 assert(ssh->queueing);
2432 if (ssh->queuelen >= ssh->queuesize) {
2433 ssh->queuesize = ssh->queuelen + 32;
2434 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
2437 ssh->queue[ssh->queuelen++] = pkt;
2441 * Either queue or send a packet, depending on whether queueing is
2444 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
2447 ssh2_pkt_queue(ssh, pkt);
2449 ssh2_pkt_send_noqueue(ssh, pkt);
2453 * Either queue or defer a packet, depending on whether queueing is
2456 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
2459 ssh2_pkt_queue(ssh, pkt);
2461 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2465 * Send the whole deferred data block constructed by
2466 * ssh2_pkt_defer() or SSH-1's defer_packet().
2468 * The expected use of the defer mechanism is that you call
2469 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2470 * not currently queueing, this simply sets up deferred_send_data
2471 * and then sends it. If we _are_ currently queueing, the calls to
2472 * ssh2_pkt_defer() put the deferred packets on to the queue
2473 * instead, and therefore ssh_pkt_defersend() has no deferred data
2474 * to send. Hence, there's no need to make it conditional on
2477 static void ssh_pkt_defersend(Ssh ssh)
2480 backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
2481 ssh->deferred_len = ssh->deferred_size = 0;
2482 sfree(ssh->deferred_send_data);
2483 ssh->deferred_send_data = NULL;
2484 if (backlog > SSH_MAX_BACKLOG)
2485 ssh_throttle_all(ssh, 1, backlog);
2487 ssh->outgoing_data_size += ssh->deferred_data_size;
2488 if (!ssh->kex_in_progress &&
2489 !ssh->bare_connection &&
2490 ssh->max_data_size != 0 &&
2491 ssh->outgoing_data_size > ssh->max_data_size)
2492 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2493 ssh->deferred_data_size = 0;
2497 * Send a packet whose length needs to be disguised (typically
2498 * passwords or keyboard-interactive responses).
2500 static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
2506 * The simplest way to do this is to adjust the
2507 * variable-length padding field in the outgoing packet.
2509 * Currently compiled out, because some Cisco SSH servers
2510 * don't like excessively padded packets (bah, why's it
2513 pkt->forcepad = padsize;
2514 ssh2_pkt_send(ssh, pkt);
2519 * If we can't do that, however, an alternative approach is
2520 * to use the pkt_defer mechanism to bundle the packet
2521 * tightly together with an SSH_MSG_IGNORE such that their
2522 * combined length is a constant. So first we construct the
2523 * final form of this packet and defer its sending.
2525 ssh2_pkt_defer(ssh, pkt);
2528 * Now construct an SSH_MSG_IGNORE which includes a string
2529 * that's an exact multiple of the cipher block size. (If
2530 * the cipher is NULL so that the block size is
2531 * unavailable, we don't do this trick at all, because we
2532 * gain nothing by it.)
2534 if (ssh->cscipher &&
2535 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2538 stringlen = (256 - ssh->deferred_len);
2539 stringlen += ssh->cscipher->blksize - 1;
2540 stringlen -= (stringlen % ssh->cscipher->blksize);
2543 * Temporarily disable actual compression, so we
2544 * can guarantee to get this string exactly the
2545 * length we want it. The compression-disabling
2546 * routine should return an integer indicating how
2547 * many bytes we should adjust our string length
2551 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
2553 pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2554 ssh2_pkt_addstring_start(pkt);
2555 for (i = 0; i < stringlen; i++) {
2556 char c = (char) random_byte();
2557 ssh2_pkt_addstring_data(pkt, &c, 1);
2559 ssh2_pkt_defer(ssh, pkt);
2561 ssh_pkt_defersend(ssh);
2566 * Send all queued SSH-2 packets. We send them by means of
2567 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2568 * packets that needed to be lumped together.
2570 static void ssh2_pkt_queuesend(Ssh ssh)
2574 assert(!ssh->queueing);
2576 for (i = 0; i < ssh->queuelen; i++)
2577 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
2580 ssh_pkt_defersend(ssh);
2584 void bndebug(char *string, Bignum b)
2588 p = ssh2_mpint_fmt(b, &len);
2589 debug(("%s", string));
2590 for (i = 0; i < len; i++)
2591 debug((" %02x", p[i]));
2597 static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
2601 p = ssh2_mpint_fmt(b, &len);
2602 hash_string(h, s, p, len);
2607 * Packet decode functions for both SSH-1 and SSH-2.
2609 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
2611 unsigned long value;
2612 if (pkt->length - pkt->savedpos < 4)
2613 return 0; /* arrgh, no way to decline (FIXME?) */
2614 value = GET_32BIT(pkt->body + pkt->savedpos);
2618 static int ssh2_pkt_getbool(struct Packet *pkt)
2620 unsigned long value;
2621 if (pkt->length - pkt->savedpos < 1)
2622 return 0; /* arrgh, no way to decline (FIXME?) */
2623 value = pkt->body[pkt->savedpos] != 0;
2627 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
2632 if (pkt->length - pkt->savedpos < 4)
2634 len = toint(GET_32BIT(pkt->body + pkt->savedpos));
2639 if (pkt->length - pkt->savedpos < *length)
2641 *p = (char *)(pkt->body + pkt->savedpos);
2642 pkt->savedpos += *length;
2644 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
2646 if (pkt->length - pkt->savedpos < length)
2648 pkt->savedpos += length;
2649 return pkt->body + (pkt->savedpos - length);
2651 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2652 const unsigned char **keystr)
2656 j = makekey(pkt->body + pkt->savedpos,
2657 pkt->length - pkt->savedpos,
2664 assert(pkt->savedpos < pkt->length);
2668 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2673 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2674 pkt->length - pkt->savedpos, &b);
2682 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2688 ssh_pkt_getstring(pkt, &p, &length);
2693 b = bignum_from_bytes((unsigned char *)p, length);
2698 * Helper function to add an SSH-2 signature blob to a packet.
2699 * Expects to be shown the public key blob as well as the signature
2700 * blob. Normally works just like ssh2_pkt_addstring, but will
2701 * fiddle with the signature packet if necessary for
2702 * BUG_SSH2_RSA_PADDING.
2704 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2705 void *pkblob_v, int pkblob_len,
2706 void *sigblob_v, int sigblob_len)
2708 unsigned char *pkblob = (unsigned char *)pkblob_v;
2709 unsigned char *sigblob = (unsigned char *)sigblob_v;
2711 /* dmemdump(pkblob, pkblob_len); */
2712 /* dmemdump(sigblob, sigblob_len); */
2715 * See if this is in fact an ssh-rsa signature and a buggy
2716 * server; otherwise we can just do this the easy way.
2718 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) && pkblob_len > 4+7+4 &&
2719 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2720 int pos, len, siglen;
2723 * Find the byte length of the modulus.
2726 pos = 4+7; /* skip over "ssh-rsa" */
2727 len = toint(GET_32BIT(pkblob+pos)); /* get length of exponent */
2728 if (len < 0 || len > pkblob_len - pos - 4)
2730 pos += 4 + len; /* skip over exponent */
2731 if (pkblob_len - pos < 4)
2733 len = toint(GET_32BIT(pkblob+pos)); /* find length of modulus */
2734 if (len < 0 || len > pkblob_len - pos - 4)
2736 pos += 4; /* find modulus itself */
2737 while (len > 0 && pkblob[pos] == 0)
2739 /* debug(("modulus length is %d\n", len)); */
2742 * Now find the signature integer.
2744 pos = 4+7; /* skip over "ssh-rsa" */
2745 if (sigblob_len < pos+4)
2747 siglen = toint(GET_32BIT(sigblob+pos));
2748 if (siglen != sigblob_len - pos - 4)
2750 /* debug(("signature length is %d\n", siglen)); */
2752 if (len != siglen) {
2753 unsigned char newlen[4];
2754 ssh2_pkt_addstring_start(pkt);
2755 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2756 /* dmemdump(sigblob, pos); */
2757 pos += 4; /* point to start of actual sig */
2758 PUT_32BIT(newlen, len);
2759 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2760 /* dmemdump(newlen, 4); */
2762 while (len-- > siglen) {
2763 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2764 /* dmemdump(newlen, 1); */
2766 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2767 /* dmemdump(sigblob+pos, siglen); */
2771 /* Otherwise fall through and do it the easy way. We also come
2772 * here as a fallback if we discover above that the key blob
2773 * is misformatted in some way. */
2777 ssh2_pkt_addstring_start(pkt);
2778 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2782 * Examine the remote side's version string and compare it against
2783 * a list of known buggy implementations.
2785 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2787 char *imp; /* pointer to implementation part */
2789 imp += strcspn(imp, "-");
2791 imp += strcspn(imp, "-");
2794 ssh->remote_bugs = 0;
2797 * General notes on server version strings:
2798 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2799 * here -- in particular, we've heard of one that's perfectly happy
2800 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2801 * so we can't distinguish them.
2803 if (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == FORCE_ON ||
2804 (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == AUTO &&
2805 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2806 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2807 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2808 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2810 * These versions don't support SSH1_MSG_IGNORE, so we have
2811 * to use a different defence against password length
2814 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2815 logevent("We believe remote version has SSH-1 ignore bug");
2818 if (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == FORCE_ON ||
2819 (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == AUTO &&
2820 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2822 * These versions need a plain password sent; they can't
2823 * handle having a null and a random length of data after
2826 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2827 logevent("We believe remote version needs a plain SSH-1 password");
2830 if (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == FORCE_ON ||
2831 (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == AUTO &&
2832 (!strcmp(imp, "Cisco-1.25")))) {
2834 * These versions apparently have no clue whatever about
2835 * RSA authentication and will panic and die if they see
2836 * an AUTH_RSA message.
2838 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2839 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2842 if (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == FORCE_ON ||
2843 (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == AUTO &&
2844 !wc_match("* VShell", imp) &&
2845 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2846 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2847 wc_match("2.1 *", imp)))) {
2849 * These versions have the HMAC bug.
2851 ssh->remote_bugs |= BUG_SSH2_HMAC;
2852 logevent("We believe remote version has SSH-2 HMAC bug");
2855 if (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == FORCE_ON ||
2856 (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == AUTO &&
2857 !wc_match("* VShell", imp) &&
2858 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2860 * These versions have the key-derivation bug (failing to
2861 * include the literal shared secret in the hashes that
2862 * generate the keys).
2864 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2865 logevent("We believe remote version has SSH-2 key-derivation bug");
2868 if (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == FORCE_ON ||
2869 (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == AUTO &&
2870 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2871 wc_match("OpenSSH_3.[0-2]*", imp) ||
2872 wc_match("mod_sftp/0.[0-8]*", imp) ||
2873 wc_match("mod_sftp/0.9.[0-8]", imp)))) {
2875 * These versions have the SSH-2 RSA padding bug.
2877 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2878 logevent("We believe remote version has SSH-2 RSA padding bug");
2881 if (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == FORCE_ON ||
2882 (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == AUTO &&
2883 wc_match("OpenSSH_2.[0-2]*", imp))) {
2885 * These versions have the SSH-2 session-ID bug in
2886 * public-key authentication.
2888 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2889 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2892 if (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == FORCE_ON ||
2893 (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == AUTO &&
2894 (wc_match("DigiSSH_2.0", imp) ||
2895 wc_match("OpenSSH_2.[0-4]*", imp) ||
2896 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2897 wc_match("Sun_SSH_1.0", imp) ||
2898 wc_match("Sun_SSH_1.0.1", imp) ||
2899 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2900 wc_match("WeOnlyDo-*", imp)))) {
2902 * These versions have the SSH-2 rekey bug.
2904 ssh->remote_bugs |= BUG_SSH2_REKEY;
2905 logevent("We believe remote version has SSH-2 rekey bug");
2908 if (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == FORCE_ON ||
2909 (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == AUTO &&
2910 (wc_match("1.36_sshlib GlobalSCAPE", imp) ||
2911 wc_match("1.36 sshlib: GlobalScape", imp)))) {
2913 * This version ignores our makpkt and needs to be throttled.
2915 ssh->remote_bugs |= BUG_SSH2_MAXPKT;
2916 logevent("We believe remote version ignores SSH-2 maximum packet size");
2919 if (conf_get_int(ssh->conf, CONF_sshbug_ignore2) == FORCE_ON) {
2921 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2922 * none detected automatically.
2924 ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE;
2925 logevent("We believe remote version has SSH-2 ignore bug");
2928 if (conf_get_int(ssh->conf, CONF_sshbug_oldgex2) == FORCE_ON ||
2929 (conf_get_int(ssh->conf, CONF_sshbug_oldgex2) == AUTO &&
2930 (wc_match("OpenSSH_2.[235]*", imp)))) {
2932 * These versions only support the original (pre-RFC4419)
2933 * SSH-2 GEX request, and disconnect with a protocol error if
2934 * we use the newer version.
2936 ssh->remote_bugs |= BUG_SSH2_OLDGEX;
2937 logevent("We believe remote version has outdated SSH-2 GEX");
2940 if (conf_get_int(ssh->conf, CONF_sshbug_winadj) == FORCE_ON) {
2942 * Servers that don't support our winadj request for one
2943 * reason or another. Currently, none detected automatically.
2945 ssh->remote_bugs |= BUG_CHOKES_ON_WINADJ;
2946 logevent("We believe remote version has winadj bug");
2949 if (conf_get_int(ssh->conf, CONF_sshbug_chanreq) == FORCE_ON ||
2950 (conf_get_int(ssh->conf, CONF_sshbug_chanreq) == AUTO &&
2951 (wc_match("OpenSSH_[2-5].*", imp) ||
2952 wc_match("OpenSSH_6.[0-6]*", imp) ||
2953 wc_match("dropbear_0.[2-4][0-9]*", imp) ||
2954 wc_match("dropbear_0.5[01]*", imp)))) {
2956 * These versions have the SSH-2 channel request bug.
2957 * OpenSSH 6.7 and above do not:
2958 * https://bugzilla.mindrot.org/show_bug.cgi?id=1818
2959 * dropbear_0.52 and above do not:
2960 * https://secure.ucc.asn.au/hg/dropbear/rev/cd02449b709c
2962 ssh->remote_bugs |= BUG_SENDS_LATE_REQUEST_REPLY;
2963 logevent("We believe remote version has SSH-2 channel request bug");
2968 * The `software version' part of an SSH version string is required
2969 * to contain no spaces or minus signs.
2971 static void ssh_fix_verstring(char *str)
2973 /* Eat "<protoversion>-". */
2974 while (*str && *str != '-') str++;
2975 assert(*str == '-'); str++;
2977 /* Convert minus signs and spaces in the remaining string into
2980 if (*str == '-' || *str == ' ')
2987 * Send an appropriate SSH version string.
2989 static void ssh_send_verstring(Ssh ssh, const char *protoname, char *svers)
2993 if (ssh->version == 2) {
2995 * Construct a v2 version string.
2997 verstring = dupprintf("%s2.0-%s\015\012", protoname, sshver);
3000 * Construct a v1 version string.
3002 assert(!strcmp(protoname, "SSH-")); /* no v1 bare connection protocol */
3003 verstring = dupprintf("SSH-%s-%s\012",
3004 (ssh_versioncmp(svers, "1.5") <= 0 ?
3009 ssh_fix_verstring(verstring + strlen(protoname));
3011 if (ssh->version == 2) {
3014 * Record our version string.
3016 len = strcspn(verstring, "\015\012");
3017 ssh->v_c = snewn(len + 1, char);
3018 memcpy(ssh->v_c, verstring, len);
3022 logeventf(ssh, "We claim version: %.*s",
3023 strcspn(verstring, "\015\012"), verstring);
3024 s_write(ssh, verstring, strlen(verstring));
3028 static int do_ssh_init(Ssh ssh, unsigned char c)
3030 static const char protoname[] = "SSH-";
3032 struct do_ssh_init_state {
3041 crState(do_ssh_init_state);
3045 /* Search for a line beginning with the protocol name prefix in
3048 for (s->i = 0; protoname[s->i]; s->i++) {
3049 if ((char)c != protoname[s->i]) goto no;
3059 s->vstrsize = sizeof(protoname) + 16;
3060 s->vstring = snewn(s->vstrsize, char);
3061 strcpy(s->vstring, protoname);
3062 s->vslen = strlen(protoname);
3065 if (s->vslen >= s->vstrsize - 1) {
3067 s->vstring = sresize(s->vstring, s->vstrsize, char);
3069 s->vstring[s->vslen++] = c;
3072 s->version[s->i] = '\0';
3074 } else if (s->i < sizeof(s->version) - 1)
3075 s->version[s->i++] = c;
3076 } else if (c == '\012')
3078 crReturn(1); /* get another char */
3081 ssh->agentfwd_enabled = FALSE;
3082 ssh->rdpkt2_state.incoming_sequence = 0;
3084 s->vstring[s->vslen] = 0;
3085 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
3086 logeventf(ssh, "Server version: %s", s->vstring);
3087 ssh_detect_bugs(ssh, s->vstring);
3090 * Decide which SSH protocol version to support.
3093 /* Anything strictly below "2.0" means protocol 1 is supported. */
3094 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
3095 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
3096 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
3098 if (conf_get_int(ssh->conf, CONF_sshprot) == 0 && !s->proto1) {
3099 bombout(("SSH protocol version 1 required by configuration but "
3100 "not provided by server"));
3103 if (conf_get_int(ssh->conf, CONF_sshprot) == 3 && !s->proto2) {
3104 bombout(("SSH protocol version 2 required by configuration but "
3105 "not provided by server"));
3109 if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1))
3114 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
3116 /* Send the version string, if we haven't already */
3117 if (conf_get_int(ssh->conf, CONF_sshprot) != 3)
3118 ssh_send_verstring(ssh, protoname, s->version);
3120 if (ssh->version == 2) {
3123 * Record their version string.
3125 len = strcspn(s->vstring, "\015\012");
3126 ssh->v_s = snewn(len + 1, char);
3127 memcpy(ssh->v_s, s->vstring, len);
3131 * Initialise SSH-2 protocol.
3133 ssh->protocol = ssh2_protocol;
3134 ssh2_protocol_setup(ssh);
3135 ssh->s_rdpkt = ssh2_rdpkt;
3138 * Initialise SSH-1 protocol.
3140 ssh->protocol = ssh1_protocol;
3141 ssh1_protocol_setup(ssh);
3142 ssh->s_rdpkt = ssh1_rdpkt;
3144 if (ssh->version == 2)
3145 do_ssh2_transport(ssh, NULL, -1, NULL);
3147 update_specials_menu(ssh->frontend);
3148 ssh->state = SSH_STATE_BEFORE_SIZE;
3149 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3156 static int do_ssh_connection_init(Ssh ssh, unsigned char c)
3159 * Ordinary SSH begins with the banner "SSH-x.y-...". This is just
3160 * the ssh-connection part, extracted and given a trivial binary
3161 * packet protocol, so we replace 'SSH-' at the start with a new
3162 * name. In proper SSH style (though of course this part of the
3163 * proper SSH protocol _isn't_ subject to this kind of
3164 * DNS-domain-based extension), we define the new name in our
3167 static const char protoname[] =
3168 "SSHCONNECTION@putty.projects.tartarus.org-";
3170 struct do_ssh_connection_init_state {
3178 crState(do_ssh_connection_init_state);
3182 /* Search for a line beginning with the protocol name prefix in
3185 for (s->i = 0; protoname[s->i]; s->i++) {
3186 if ((char)c != protoname[s->i]) goto no;
3196 s->vstrsize = sizeof(protoname) + 16;
3197 s->vstring = snewn(s->vstrsize, char);
3198 strcpy(s->vstring, protoname);
3199 s->vslen = strlen(protoname);
3202 if (s->vslen >= s->vstrsize - 1) {
3204 s->vstring = sresize(s->vstring, s->vstrsize, char);
3206 s->vstring[s->vslen++] = c;
3209 s->version[s->i] = '\0';
3211 } else if (s->i < sizeof(s->version) - 1)
3212 s->version[s->i++] = c;
3213 } else if (c == '\012')
3215 crReturn(1); /* get another char */
3218 ssh->agentfwd_enabled = FALSE;
3219 ssh->rdpkt2_bare_state.incoming_sequence = 0;
3221 s->vstring[s->vslen] = 0;
3222 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
3223 logeventf(ssh, "Server version: %s", s->vstring);
3224 ssh_detect_bugs(ssh, s->vstring);
3227 * Decide which SSH protocol version to support. This is easy in
3228 * bare ssh-connection mode: only 2.0 is legal.
3230 if (ssh_versioncmp(s->version, "2.0") < 0) {
3231 bombout(("Server announces compatibility with SSH-1 in bare ssh-connection protocol"));
3234 if (conf_get_int(ssh->conf, CONF_sshprot) == 0) {
3235 bombout(("Bare ssh-connection protocol cannot be run in SSH-1-only mode"));
3241 logeventf(ssh, "Using bare ssh-connection protocol");
3243 /* Send the version string, if we haven't already */
3244 ssh_send_verstring(ssh, protoname, s->version);
3247 * Initialise bare connection protocol.
3249 ssh->protocol = ssh2_bare_connection_protocol;
3250 ssh2_bare_connection_protocol_setup(ssh);
3251 ssh->s_rdpkt = ssh2_bare_connection_rdpkt;
3253 update_specials_menu(ssh->frontend);
3254 ssh->state = SSH_STATE_BEFORE_SIZE;
3255 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3258 * Get authconn (really just conn) under way.
3260 do_ssh2_authconn(ssh, NULL, 0, NULL);
3267 static void ssh_process_incoming_data(Ssh ssh,
3268 const unsigned char **data, int *datalen)
3270 struct Packet *pktin;
3272 pktin = ssh->s_rdpkt(ssh, data, datalen);
3274 ssh->protocol(ssh, NULL, 0, pktin);
3275 ssh_free_packet(pktin);
3279 static void ssh_queue_incoming_data(Ssh ssh,
3280 const unsigned char **data, int *datalen)
3282 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
3287 static void ssh_process_queued_incoming_data(Ssh ssh)
3290 const unsigned char *data;
3293 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
3294 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
3298 while (!ssh->frozen && len > 0)
3299 ssh_process_incoming_data(ssh, &data, &len);
3302 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
3306 static void ssh_set_frozen(Ssh ssh, int frozen)
3309 sk_set_frozen(ssh->s, frozen);
3310 ssh->frozen = frozen;
3313 static void ssh_gotdata(Ssh ssh, const unsigned char *data, int datalen)
3315 /* Log raw data, if we're in that mode. */
3317 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
3318 0, NULL, NULL, 0, NULL);
3320 crBegin(ssh->ssh_gotdata_crstate);
3323 * To begin with, feed the characters one by one to the
3324 * protocol initialisation / selection function do_ssh_init().
3325 * When that returns 0, we're done with the initial greeting
3326 * exchange and can move on to packet discipline.
3329 int ret; /* need not be kept across crReturn */
3331 crReturnV; /* more data please */
3332 ret = ssh->do_ssh_init(ssh, *data);
3340 * We emerge from that loop when the initial negotiation is
3341 * over and we have selected an s_rdpkt function. Now pass
3342 * everything to s_rdpkt, and then pass the resulting packets
3343 * to the proper protocol handler.
3347 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
3349 ssh_queue_incoming_data(ssh, &data, &datalen);
3350 /* This uses up all data and cannot cause anything interesting
3351 * to happen; indeed, for anything to happen at all, we must
3352 * return, so break out. */
3354 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
3355 /* This uses up some or all data, and may freeze the
3357 ssh_process_queued_incoming_data(ssh);
3359 /* This uses up some or all data, and may freeze the
3361 ssh_process_incoming_data(ssh, &data, &datalen);
3363 /* FIXME this is probably EBW. */
3364 if (ssh->state == SSH_STATE_CLOSED)
3367 /* We're out of data. Go and get some more. */
3373 static int ssh_do_close(Ssh ssh, int notify_exit)
3376 struct ssh_channel *c;
3378 ssh->state = SSH_STATE_CLOSED;
3379 expire_timer_context(ssh);
3384 notify_remote_exit(ssh->frontend);
3389 * Now we must shut down any port- and X-forwarded channels going
3390 * through this connection.
3392 if (ssh->channels) {
3393 while (NULL != (c = index234(ssh->channels, 0))) {
3396 x11_close(c->u.x11.xconn);
3399 case CHAN_SOCKDATA_DORMANT:
3400 pfd_close(c->u.pfd.pf);
3403 del234(ssh->channels, c); /* moving next one to index 0 */
3404 if (ssh->version == 2)
3405 bufchain_clear(&c->v.v2.outbuffer);
3410 * Go through port-forwardings, and close any associated
3411 * listening sockets.
3413 if (ssh->portfwds) {
3414 struct ssh_portfwd *pf;
3415 while (NULL != (pf = index234(ssh->portfwds, 0))) {
3416 /* Dispose of any listening socket. */
3418 pfl_terminate(pf->local);
3419 del234(ssh->portfwds, pf); /* moving next one to index 0 */
3422 freetree234(ssh->portfwds);
3423 ssh->portfwds = NULL;
3427 * Also stop attempting to connection-share.
3429 if (ssh->connshare) {
3430 sharestate_free(ssh->connshare);
3431 ssh->connshare = NULL;
3437 static void ssh_socket_log(Plug plug, int type, SockAddr addr, int port,
3438 const char *error_msg, int error_code)
3440 Ssh ssh = (Ssh) plug;
3441 char addrbuf[256], *msg;
3443 if (ssh->attempting_connshare) {
3445 * While we're attempting connection sharing, don't loudly log
3446 * everything that happens. Real TCP connections need to be
3447 * logged when we _start_ trying to connect, because it might
3448 * be ages before they respond if something goes wrong; but
3449 * connection sharing is local and quick to respond, and it's
3450 * sufficient to simply wait and see whether it worked
3454 sk_getaddr(addr, addrbuf, lenof(addrbuf));
3457 if (sk_addr_needs_port(addr)) {
3458 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
3460 msg = dupprintf("Connecting to %s", addrbuf);
3463 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
3471 void ssh_connshare_log(Ssh ssh, int event, const char *logtext,
3472 const char *ds_err, const char *us_err)
3474 if (event == SHARE_NONE) {
3475 /* In this case, 'logtext' is an error message indicating a
3476 * reason why connection sharing couldn't be set up _at all_.
3477 * Failing that, ds_err and us_err indicate why we couldn't be
3478 * a downstream and an upstream respectively. */
3480 logeventf(ssh, "Could not set up connection sharing: %s", logtext);
3483 logeventf(ssh, "Could not set up connection sharing"
3484 " as downstream: %s", ds_err);
3486 logeventf(ssh, "Could not set up connection sharing"
3487 " as upstream: %s", us_err);
3489 } else if (event == SHARE_DOWNSTREAM) {
3490 /* In this case, 'logtext' is a local endpoint address */
3491 logeventf(ssh, "Using existing shared connection at %s", logtext);
3492 /* Also we should mention this in the console window to avoid
3493 * confusing users as to why this window doesn't behave the
3495 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3496 c_write_str(ssh,"Reusing a shared connection to this server.\r\n");
3498 } else if (event == SHARE_UPSTREAM) {
3499 /* In this case, 'logtext' is a local endpoint address too */
3500 logeventf(ssh, "Sharing this connection at %s", logtext);
3504 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
3507 Ssh ssh = (Ssh) plug;
3508 int need_notify = ssh_do_close(ssh, FALSE);
3511 if (!ssh->close_expected)
3512 error_msg = "Server unexpectedly closed network connection";
3514 error_msg = "Server closed network connection";
3517 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
3521 notify_remote_exit(ssh->frontend);
3524 logevent(error_msg);
3525 if (!ssh->close_expected || !ssh->clean_exit)
3526 connection_fatal(ssh->frontend, "%s", error_msg);
3530 static int ssh_receive(Plug plug, int urgent, char *data, int len)
3532 Ssh ssh = (Ssh) plug;
3533 ssh_gotdata(ssh, (unsigned char *)data, len);
3534 if (ssh->state == SSH_STATE_CLOSED) {
3535 ssh_do_close(ssh, TRUE);
3541 static void ssh_sent(Plug plug, int bufsize)
3543 Ssh ssh = (Ssh) plug;
3545 * If the send backlog on the SSH socket itself clears, we
3546 * should unthrottle the whole world if it was throttled.
3548 if (bufsize < SSH_MAX_BACKLOG)
3549 ssh_throttle_all(ssh, 0, bufsize);
3552 static void ssh_hostport_setup(const char *host, int port, Conf *conf,
3553 char **savedhost, int *savedport,
3556 char *loghost = conf_get_str(conf, CONF_loghost);
3558 *loghost_ret = loghost;
3564 tmphost = dupstr(loghost);
3565 *savedport = 22; /* default ssh port */
3568 * A colon suffix on the hostname string also lets us affect
3569 * savedport. (Unless there are multiple colons, in which case
3570 * we assume this is an unbracketed IPv6 literal.)
3572 colon = host_strrchr(tmphost, ':');
3573 if (colon && colon == host_strchr(tmphost, ':')) {
3576 *savedport = atoi(colon);
3579 *savedhost = host_strduptrim(tmphost);
3582 *savedhost = host_strduptrim(host);
3584 port = 22; /* default ssh port */
3589 static int ssh_test_for_upstream(const char *host, int port, Conf *conf)
3595 random_ref(); /* platform may need this to determine share socket name */
3596 ssh_hostport_setup(host, port, conf, &savedhost, &savedport, NULL);
3597 ret = ssh_share_test_for_upstream(savedhost, savedport, conf);
3605 * Connect to specified host and port.
3606 * Returns an error message, or NULL on success.
3607 * Also places the canonical host name into `realhost'. It must be
3608 * freed by the caller.
3610 static const char *connect_to_host(Ssh ssh, const char *host, int port,
3611 char **realhost, int nodelay, int keepalive)
3613 static const struct plug_function_table fn_table = {
3624 int addressfamily, sshprot;
3626 ssh_hostport_setup(host, port, ssh->conf,
3627 &ssh->savedhost, &ssh->savedport, &loghost);
3629 ssh->fn = &fn_table; /* make 'ssh' usable as a Plug */
3632 * Try connection-sharing, in case that means we don't open a
3633 * socket after all. ssh_connection_sharing_init will connect to a
3634 * previously established upstream if it can, and failing that,
3635 * establish a listening socket for _us_ to be the upstream. In
3636 * the latter case it will return NULL just as if it had done
3637 * nothing, because here we only need to care if we're a
3638 * downstream and need to do our connection setup differently.
3640 ssh->connshare = NULL;
3641 ssh->attempting_connshare = TRUE; /* affects socket logging behaviour */
3642 ssh->s = ssh_connection_sharing_init(ssh->savedhost, ssh->savedport,
3643 ssh->conf, ssh, &ssh->connshare);
3644 ssh->attempting_connshare = FALSE;
3645 if (ssh->s != NULL) {
3647 * We are a downstream.
3649 ssh->bare_connection = TRUE;
3650 ssh->do_ssh_init = do_ssh_connection_init;
3651 ssh->fullhostname = NULL;
3652 *realhost = dupstr(host); /* best we can do */
3655 * We're not a downstream, so open a normal socket.
3657 ssh->do_ssh_init = do_ssh_init;
3662 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
3663 logeventf(ssh, "Looking up host \"%s\"%s", host,
3664 (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
3665 (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
3666 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily);
3667 if ((err = sk_addr_error(addr)) != NULL) {
3671 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3673 ssh->s = new_connection(addr, *realhost, port,
3674 0, 1, nodelay, keepalive,
3675 (Plug) ssh, ssh->conf);
3676 if ((err = sk_socket_error(ssh->s)) != NULL) {
3678 notify_remote_exit(ssh->frontend);
3684 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3685 * send the version string too.
3687 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3690 if (sshprot == 3 && !ssh->bare_connection) {
3692 ssh_send_verstring(ssh, "SSH-", NULL);
3696 * loghost, if configured, overrides realhost.
3700 *realhost = dupstr(loghost);
3707 * Throttle or unthrottle the SSH connection.
3709 static void ssh_throttle_conn(Ssh ssh, int adjust)
3711 int old_count = ssh->conn_throttle_count;
3712 ssh->conn_throttle_count += adjust;
3713 assert(ssh->conn_throttle_count >= 0);
3714 if (ssh->conn_throttle_count && !old_count) {
3715 ssh_set_frozen(ssh, 1);
3716 } else if (!ssh->conn_throttle_count && old_count) {
3717 ssh_set_frozen(ssh, 0);
3722 * Throttle or unthrottle _all_ local data streams (for when sends
3723 * on the SSH connection itself back up).
3725 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3728 struct ssh_channel *c;
3730 if (enable == ssh->throttled_all)
3732 ssh->throttled_all = enable;
3733 ssh->overall_bufsize = bufsize;
3736 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3738 case CHAN_MAINSESSION:
3740 * This is treated separately, outside the switch.
3744 x11_override_throttle(c->u.x11.xconn, enable);
3747 /* Agent channels require no buffer management. */
3750 pfd_override_throttle(c->u.pfd.pf, enable);
3756 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3758 Ssh ssh = (Ssh) sshv;
3760 ssh->agent_response = reply;
3761 ssh->agent_response_len = replylen;
3763 if (ssh->version == 1)
3764 do_ssh1_login(ssh, NULL, -1, NULL);
3766 do_ssh2_authconn(ssh, NULL, -1, NULL);
3769 static void ssh_dialog_callback(void *sshv, int ret)
3771 Ssh ssh = (Ssh) sshv;
3773 ssh->user_response = ret;
3775 if (ssh->version == 1)
3776 do_ssh1_login(ssh, NULL, -1, NULL);
3778 do_ssh2_transport(ssh, NULL, -1, NULL);
3781 * This may have unfrozen the SSH connection, so do a
3784 ssh_process_queued_incoming_data(ssh);
3787 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3789 struct ssh_channel *c = (struct ssh_channel *)cv;
3791 const void *sentreply = reply;
3793 c->u.a.outstanding_requests--;
3795 /* Fake SSH_AGENT_FAILURE. */
3796 sentreply = "\0\0\0\1\5";
3799 if (ssh->version == 2) {
3800 ssh2_add_channel_data(c, sentreply, replylen);
3803 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3804 PKT_INT, c->remoteid,
3806 PKT_DATA, sentreply, replylen,
3812 * If we've already seen an incoming EOF but haven't sent an
3813 * outgoing one, this may be the moment to send it.
3815 if (c->u.a.outstanding_requests == 0 && (c->closes & CLOSES_RCVD_EOF))
3816 sshfwd_write_eof(c);
3820 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3821 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3822 * => log `wire_reason'.
3824 static void ssh_disconnect(Ssh ssh, const char *client_reason,
3825 const char *wire_reason,
3826 int code, int clean_exit)
3830 client_reason = wire_reason;
3832 error = dupprintf("Disconnected: %s", client_reason);
3834 error = dupstr("Disconnected");
3836 if (ssh->version == 1) {
3837 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3839 } else if (ssh->version == 2) {
3840 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3841 ssh2_pkt_adduint32(pktout, code);
3842 ssh2_pkt_addstring(pktout, wire_reason);
3843 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3844 ssh2_pkt_send_noqueue(ssh, pktout);
3847 ssh->close_expected = TRUE;
3848 ssh->clean_exit = clean_exit;
3849 ssh_closing((Plug)ssh, error, 0, 0);
3853 int verify_ssh_manual_host_key(Ssh ssh, const char *fingerprint,
3854 const struct ssh_signkey *ssh2keytype,
3857 if (!conf_get_str_nthstrkey(ssh->conf, CONF_ssh_manual_hostkeys, 0)) {
3858 return -1; /* no manual keys configured */
3863 * The fingerprint string we've been given will have things
3864 * like 'ssh-rsa 2048' at the front of it. Strip those off and
3865 * narrow down to just the colon-separated hex block at the
3866 * end of the string.
3868 const char *p = strrchr(fingerprint, ' ');
3869 fingerprint = p ? p+1 : fingerprint;
3870 /* Quick sanity checks, including making sure it's in lowercase */
3871 assert(strlen(fingerprint) == 16*3 - 1);
3872 assert(fingerprint[2] == ':');
3873 assert(fingerprint[strspn(fingerprint, "0123456789abcdef:")] == 0);
3875 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3877 return 1; /* success */
3882 * Construct the base64-encoded public key blob and see if
3885 unsigned char *binblob;
3887 int binlen, atoms, i;
3888 binblob = ssh2keytype->public_blob(ssh2keydata, &binlen);
3889 atoms = (binlen + 2) / 3;
3890 base64blob = snewn(atoms * 4 + 1, char);
3891 for (i = 0; i < atoms; i++)
3892 base64_encode_atom(binblob + 3*i, binlen - 3*i, base64blob + 4*i);
3893 base64blob[atoms * 4] = '\0';
3895 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3898 return 1; /* success */
3907 * Handle the key exchange and user authentication phases.
3909 static int do_ssh1_login(Ssh ssh, const unsigned char *in, int inlen,
3910 struct Packet *pktin)
3913 unsigned char cookie[8], *ptr;
3914 struct MD5Context md5c;
3915 struct do_ssh1_login_state {
3918 unsigned char *rsabuf;
3919 const unsigned char *keystr1, *keystr2;
3920 unsigned long supported_ciphers_mask, supported_auths_mask;
3921 int tried_publickey, tried_agent;
3922 int tis_auth_refused, ccard_auth_refused;
3923 unsigned char session_id[16];
3925 void *publickey_blob;
3926 int publickey_bloblen;
3927 char *publickey_comment;
3928 int privatekey_available, privatekey_encrypted;
3929 prompts_t *cur_prompt;
3932 unsigned char request[5], *response, *p;
3942 struct RSAKey servkey, hostkey;
3944 crState(do_ssh1_login_state);
3951 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
3952 bombout(("Public key packet not received"));
3956 logevent("Received public keys");
3958 ptr = ssh_pkt_getdata(pktin, 8);
3960 bombout(("SSH-1 public key packet stopped before random cookie"));
3963 memcpy(cookie, ptr, 8);
3965 if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) ||
3966 !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) {
3967 bombout(("Failed to read SSH-1 public keys from public key packet"));
3972 * Log the host key fingerprint.
3976 logevent("Host key fingerprint is:");
3977 strcpy(logmsg, " ");
3978 s->hostkey.comment = NULL;
3979 rsa_fingerprint(logmsg + strlen(logmsg),
3980 sizeof(logmsg) - strlen(logmsg), &s->hostkey);
3984 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3985 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3986 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
3987 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
3988 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
3990 ssh->v1_local_protoflags =
3991 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3992 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
3995 MD5Update(&md5c, s->keystr2, s->hostkey.bytes);
3996 MD5Update(&md5c, s->keystr1, s->servkey.bytes);
3997 MD5Update(&md5c, cookie, 8);
3998 MD5Final(s->session_id, &md5c);
4000 for (i = 0; i < 32; i++)
4001 ssh->session_key[i] = random_byte();
4004 * Verify that the `bits' and `bytes' parameters match.
4006 if (s->hostkey.bits > s->hostkey.bytes * 8 ||
4007 s->servkey.bits > s->servkey.bytes * 8) {
4008 bombout(("SSH-1 public keys were badly formatted"));
4012 s->len = (s->hostkey.bytes > s->servkey.bytes ?
4013 s->hostkey.bytes : s->servkey.bytes);
4015 s->rsabuf = snewn(s->len, unsigned char);
4018 * Verify the host key.
4022 * First format the key into a string.
4024 int len = rsastr_len(&s->hostkey);
4025 char fingerprint[100];
4026 char *keystr = snewn(len, char);
4027 rsastr_fmt(keystr, &s->hostkey);
4028 rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey);
4030 /* First check against manually configured host keys. */
4031 s->dlgret = verify_ssh_manual_host_key(ssh, fingerprint, NULL, NULL);
4032 if (s->dlgret == 0) { /* did not match */
4033 bombout(("Host key did not appear in manually configured list"));
4036 } else if (s->dlgret < 0) { /* none configured; use standard handling */
4037 ssh_set_frozen(ssh, 1);
4038 s->dlgret = verify_ssh_host_key(ssh->frontend,
4039 ssh->savedhost, ssh->savedport,
4040 "rsa", keystr, fingerprint,
4041 ssh_dialog_callback, ssh);
4043 if (s->dlgret < 0) {
4047 bombout(("Unexpected data from server while waiting"
4048 " for user host key response"));
4051 } while (pktin || inlen > 0);
4052 s->dlgret = ssh->user_response;
4054 ssh_set_frozen(ssh, 0);
4056 if (s->dlgret == 0) {
4057 ssh_disconnect(ssh, "User aborted at host key verification",
4066 for (i = 0; i < 32; i++) {
4067 s->rsabuf[i] = ssh->session_key[i];
4069 s->rsabuf[i] ^= s->session_id[i];
4072 if (s->hostkey.bytes > s->servkey.bytes) {
4073 ret = rsaencrypt(s->rsabuf, 32, &s->servkey);
4075 ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey);
4077 ret = rsaencrypt(s->rsabuf, 32, &s->hostkey);
4079 ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey);
4082 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
4086 logevent("Encrypted session key");
4089 int cipher_chosen = 0, warn = 0;
4090 const char *cipher_string = NULL;
4092 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
4093 int next_cipher = conf_get_int_int(ssh->conf,
4094 CONF_ssh_cipherlist, i);
4095 if (next_cipher == CIPHER_WARN) {
4096 /* If/when we choose a cipher, warn about it */
4098 } else if (next_cipher == CIPHER_AES) {
4099 /* XXX Probably don't need to mention this. */
4100 logevent("AES not supported in SSH-1, skipping");
4102 switch (next_cipher) {
4103 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
4104 cipher_string = "3DES"; break;
4105 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
4106 cipher_string = "Blowfish"; break;
4107 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
4108 cipher_string = "single-DES"; break;
4110 if (s->supported_ciphers_mask & (1 << s->cipher_type))
4114 if (!cipher_chosen) {
4115 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
4116 bombout(("Server violates SSH-1 protocol by not "
4117 "supporting 3DES encryption"));
4119 /* shouldn't happen */
4120 bombout(("No supported ciphers found"));
4124 /* Warn about chosen cipher if necessary. */
4126 ssh_set_frozen(ssh, 1);
4127 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
4128 ssh_dialog_callback, ssh);
4129 if (s->dlgret < 0) {
4133 bombout(("Unexpected data from server while waiting"
4134 " for user response"));
4137 } while (pktin || inlen > 0);
4138 s->dlgret = ssh->user_response;
4140 ssh_set_frozen(ssh, 0);
4141 if (s->dlgret == 0) {
4142 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
4149 switch (s->cipher_type) {
4150 case SSH_CIPHER_3DES:
4151 logevent("Using 3DES encryption");
4153 case SSH_CIPHER_DES:
4154 logevent("Using single-DES encryption");
4156 case SSH_CIPHER_BLOWFISH:
4157 logevent("Using Blowfish encryption");
4161 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
4162 PKT_CHAR, s->cipher_type,
4163 PKT_DATA, cookie, 8,
4164 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
4165 PKT_DATA, s->rsabuf, s->len,
4166 PKT_INT, ssh->v1_local_protoflags, PKT_END);
4168 logevent("Trying to enable encryption...");
4172 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
4173 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
4175 ssh->v1_cipher_ctx = ssh->cipher->make_context();
4176 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
4177 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
4179 ssh->crcda_ctx = crcda_make_context();
4180 logevent("Installing CRC compensation attack detector");
4182 if (s->servkey.modulus) {
4183 sfree(s->servkey.modulus);
4184 s->servkey.modulus = NULL;
4186 if (s->servkey.exponent) {
4187 sfree(s->servkey.exponent);
4188 s->servkey.exponent = NULL;
4190 if (s->hostkey.modulus) {
4191 sfree(s->hostkey.modulus);
4192 s->hostkey.modulus = NULL;
4194 if (s->hostkey.exponent) {
4195 sfree(s->hostkey.exponent);
4196 s->hostkey.exponent = NULL;
4200 if (pktin->type != SSH1_SMSG_SUCCESS) {
4201 bombout(("Encryption not successfully enabled"));
4205 logevent("Successfully started encryption");
4207 fflush(stdout); /* FIXME eh? */
4209 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
4210 int ret; /* need not be kept over crReturn */
4211 s->cur_prompt = new_prompts(ssh->frontend);
4212 s->cur_prompt->to_server = TRUE;
4213 s->cur_prompt->name = dupstr("SSH login name");
4214 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
4215 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4218 crWaitUntil(!pktin);
4219 ret = get_userpass_input(s->cur_prompt, in, inlen);
4224 * Failed to get a username. Terminate.
4226 free_prompts(s->cur_prompt);
4227 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
4230 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
4231 free_prompts(s->cur_prompt);
4234 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
4236 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
4238 if (flags & FLAG_INTERACTIVE &&
4239 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
4240 c_write_str(ssh, userlog);
4241 c_write_str(ssh, "\r\n");
4249 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
4250 /* We must not attempt PK auth. Pretend we've already tried it. */
4251 s->tried_publickey = s->tried_agent = 1;
4253 s->tried_publickey = s->tried_agent = 0;
4255 s->tis_auth_refused = s->ccard_auth_refused = 0;
4257 * Load the public half of any configured keyfile for later use.
4259 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4260 if (!filename_is_null(s->keyfile)) {
4262 logeventf(ssh, "Reading key file \"%.150s\"",
4263 filename_to_str(s->keyfile));
4264 keytype = key_type(s->keyfile);
4265 if (keytype == SSH_KEYTYPE_SSH1 ||
4266 keytype == SSH_KEYTYPE_SSH1_PUBLIC) {
4268 if (rsakey_pubblob(s->keyfile,
4269 &s->publickey_blob, &s->publickey_bloblen,
4270 &s->publickey_comment, &error)) {
4271 s->privatekey_available = (keytype == SSH_KEYTYPE_SSH1);
4272 if (!s->privatekey_available)
4273 logeventf(ssh, "Key file contains public key only");
4274 s->privatekey_encrypted = rsakey_encrypted(s->keyfile,
4278 logeventf(ssh, "Unable to load key (%s)", error);
4279 msgbuf = dupprintf("Unable to load key file "
4280 "\"%.150s\" (%s)\r\n",
4281 filename_to_str(s->keyfile),
4283 c_write_str(ssh, msgbuf);
4285 s->publickey_blob = NULL;
4289 logeventf(ssh, "Unable to use this key file (%s)",
4290 key_type_to_str(keytype));
4291 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4293 filename_to_str(s->keyfile),
4294 key_type_to_str(keytype));
4295 c_write_str(ssh, msgbuf);
4297 s->publickey_blob = NULL;
4300 s->publickey_blob = NULL;
4302 while (pktin->type == SSH1_SMSG_FAILURE) {
4303 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
4305 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
4307 * Attempt RSA authentication using Pageant.
4313 logevent("Pageant is running. Requesting keys.");
4315 /* Request the keys held by the agent. */
4316 PUT_32BIT(s->request, 1);
4317 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
4318 if (!agent_query(s->request, 5, &r, &s->responselen,
4319 ssh_agent_callback, ssh)) {
4323 bombout(("Unexpected data from server while waiting"
4324 " for agent response"));
4327 } while (pktin || inlen > 0);
4328 r = ssh->agent_response;
4329 s->responselen = ssh->agent_response_len;
4331 s->response = (unsigned char *) r;
4332 if (s->response && s->responselen >= 5 &&
4333 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
4334 s->p = s->response + 5;
4335 s->nkeys = toint(GET_32BIT(s->p));
4337 logeventf(ssh, "Pageant reported negative key count %d",
4342 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
4343 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4344 unsigned char *pkblob = s->p;
4348 do { /* do while (0) to make breaking easy */
4349 n = ssh1_read_bignum
4350 (s->p, toint(s->responselen-(s->p-s->response)),
4355 n = ssh1_read_bignum
4356 (s->p, toint(s->responselen-(s->p-s->response)),
4361 if (s->responselen - (s->p-s->response) < 4)
4363 s->commentlen = toint(GET_32BIT(s->p));
4365 if (s->commentlen < 0 ||
4366 toint(s->responselen - (s->p-s->response)) <
4369 s->commentp = (char *)s->p;
4370 s->p += s->commentlen;
4374 logevent("Pageant key list packet was truncated");
4378 if (s->publickey_blob) {
4379 if (!memcmp(pkblob, s->publickey_blob,
4380 s->publickey_bloblen)) {
4381 logeventf(ssh, "Pageant key #%d matches "
4382 "configured key file", s->keyi);
4383 s->tried_publickey = 1;
4385 /* Skip non-configured key */
4388 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
4389 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4390 PKT_BIGNUM, s->key.modulus, PKT_END);
4392 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4393 logevent("Key refused");
4396 logevent("Received RSA challenge");
4397 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4398 bombout(("Server's RSA challenge was badly formatted"));
4403 char *agentreq, *q, *ret;
4406 len = 1 + 4; /* message type, bit count */
4407 len += ssh1_bignum_length(s->key.exponent);
4408 len += ssh1_bignum_length(s->key.modulus);
4409 len += ssh1_bignum_length(s->challenge);
4410 len += 16; /* session id */
4411 len += 4; /* response format */
4412 agentreq = snewn(4 + len, char);
4413 PUT_32BIT(agentreq, len);
4415 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
4416 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
4418 q += ssh1_write_bignum(q, s->key.exponent);
4419 q += ssh1_write_bignum(q, s->key.modulus);
4420 q += ssh1_write_bignum(q, s->challenge);
4421 memcpy(q, s->session_id, 16);
4423 PUT_32BIT(q, 1); /* response format */
4424 if (!agent_query(agentreq, len + 4, &vret, &retlen,
4425 ssh_agent_callback, ssh)) {
4430 bombout(("Unexpected data from server"
4431 " while waiting for agent"
4435 } while (pktin || inlen > 0);
4436 vret = ssh->agent_response;
4437 retlen = ssh->agent_response_len;
4442 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
4443 logevent("Sending Pageant's response");
4444 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4445 PKT_DATA, ret + 5, 16,
4449 if (pktin->type == SSH1_SMSG_SUCCESS) {
4451 ("Pageant's response accepted");
4452 if (flags & FLAG_VERBOSE) {
4453 c_write_str(ssh, "Authenticated using"
4455 c_write(ssh, s->commentp,
4457 c_write_str(ssh, "\" from agent\r\n");
4462 ("Pageant's response not accepted");
4465 ("Pageant failed to answer challenge");
4469 logevent("No reply received from Pageant");
4472 freebn(s->key.exponent);
4473 freebn(s->key.modulus);
4474 freebn(s->challenge);
4479 if (s->publickey_blob && !s->tried_publickey)
4480 logevent("Configured key file not in Pageant");
4482 logevent("Failed to get reply from Pageant");
4487 if (s->publickey_blob && s->privatekey_available &&
4488 !s->tried_publickey) {
4490 * Try public key authentication with the specified
4493 int got_passphrase; /* need not be kept over crReturn */
4494 if (flags & FLAG_VERBOSE)
4495 c_write_str(ssh, "Trying public key authentication.\r\n");
4496 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4497 logeventf(ssh, "Trying public key \"%s\"",
4498 filename_to_str(s->keyfile));
4499 s->tried_publickey = 1;
4500 got_passphrase = FALSE;
4501 while (!got_passphrase) {
4503 * Get a passphrase, if necessary.
4505 char *passphrase = NULL; /* only written after crReturn */
4507 if (!s->privatekey_encrypted) {
4508 if (flags & FLAG_VERBOSE)
4509 c_write_str(ssh, "No passphrase required.\r\n");
4512 int ret; /* need not be kept over crReturn */
4513 s->cur_prompt = new_prompts(ssh->frontend);
4514 s->cur_prompt->to_server = FALSE;
4515 s->cur_prompt->name = dupstr("SSH key passphrase");
4516 add_prompt(s->cur_prompt,
4517 dupprintf("Passphrase for key \"%.100s\": ",
4518 s->publickey_comment), FALSE);
4519 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4522 crWaitUntil(!pktin);
4523 ret = get_userpass_input(s->cur_prompt, in, inlen);
4527 /* Failed to get a passphrase. Terminate. */
4528 free_prompts(s->cur_prompt);
4529 ssh_disconnect(ssh, NULL, "Unable to authenticate",
4533 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
4534 free_prompts(s->cur_prompt);
4537 * Try decrypting key with passphrase.
4539 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4540 ret = loadrsakey(s->keyfile, &s->key, passphrase,
4543 smemclr(passphrase, strlen(passphrase));
4547 /* Correct passphrase. */
4548 got_passphrase = TRUE;
4549 } else if (ret == 0) {
4550 c_write_str(ssh, "Couldn't load private key from ");
4551 c_write_str(ssh, filename_to_str(s->keyfile));
4552 c_write_str(ssh, " (");
4553 c_write_str(ssh, error);
4554 c_write_str(ssh, ").\r\n");
4555 got_passphrase = FALSE;
4556 break; /* go and try something else */
4557 } else if (ret == -1) {
4558 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
4559 got_passphrase = FALSE;
4562 assert(0 && "unexpected return from loadrsakey()");
4563 got_passphrase = FALSE; /* placate optimisers */
4567 if (got_passphrase) {
4570 * Send a public key attempt.
4572 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4573 PKT_BIGNUM, s->key.modulus, PKT_END);
4576 if (pktin->type == SSH1_SMSG_FAILURE) {
4577 c_write_str(ssh, "Server refused our public key.\r\n");
4578 continue; /* go and try something else */
4580 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4581 bombout(("Bizarre response to offer of public key"));
4587 unsigned char buffer[32];
4588 Bignum challenge, response;
4590 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4591 bombout(("Server's RSA challenge was badly formatted"));
4594 response = rsadecrypt(challenge, &s->key);
4595 freebn(s->key.private_exponent);/* burn the evidence */
4597 for (i = 0; i < 32; i++) {
4598 buffer[i] = bignum_byte(response, 31 - i);
4602 MD5Update(&md5c, buffer, 32);
4603 MD5Update(&md5c, s->session_id, 16);
4604 MD5Final(buffer, &md5c);
4606 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4607 PKT_DATA, buffer, 16, PKT_END);
4614 if (pktin->type == SSH1_SMSG_FAILURE) {
4615 if (flags & FLAG_VERBOSE)
4616 c_write_str(ssh, "Failed to authenticate with"
4617 " our public key.\r\n");
4618 continue; /* go and try something else */
4619 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4620 bombout(("Bizarre response to RSA authentication response"));
4624 break; /* we're through! */
4630 * Otherwise, try various forms of password-like authentication.
4632 s->cur_prompt = new_prompts(ssh->frontend);
4634 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4635 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
4636 !s->tis_auth_refused) {
4637 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
4638 logevent("Requested TIS authentication");
4639 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
4641 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
4642 logevent("TIS authentication declined");
4643 if (flags & FLAG_INTERACTIVE)
4644 c_write_str(ssh, "TIS authentication refused.\r\n");
4645 s->tis_auth_refused = 1;
4650 char *instr_suf, *prompt;
4652 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4654 bombout(("TIS challenge packet was badly formed"));
4657 logevent("Received TIS challenge");
4658 s->cur_prompt->to_server = TRUE;
4659 s->cur_prompt->name = dupstr("SSH TIS authentication");
4660 /* Prompt heuristic comes from OpenSSH */
4661 if (memchr(challenge, '\n', challengelen)) {
4662 instr_suf = dupstr("");
4663 prompt = dupprintf("%.*s", challengelen, challenge);
4665 instr_suf = dupprintf("%.*s", challengelen, challenge);
4666 prompt = dupstr("Response: ");
4668 s->cur_prompt->instruction =
4669 dupprintf("Using TIS authentication.%s%s",
4670 (*instr_suf) ? "\n" : "",
4672 s->cur_prompt->instr_reqd = TRUE;
4673 add_prompt(s->cur_prompt, prompt, FALSE);
4677 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4678 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
4679 !s->ccard_auth_refused) {
4680 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
4681 logevent("Requested CryptoCard authentication");
4682 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
4684 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
4685 logevent("CryptoCard authentication declined");
4686 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4687 s->ccard_auth_refused = 1;
4692 char *instr_suf, *prompt;
4694 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4696 bombout(("CryptoCard challenge packet was badly formed"));
4699 logevent("Received CryptoCard challenge");
4700 s->cur_prompt->to_server = TRUE;
4701 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4702 s->cur_prompt->name_reqd = FALSE;
4703 /* Prompt heuristic comes from OpenSSH */
4704 if (memchr(challenge, '\n', challengelen)) {
4705 instr_suf = dupstr("");
4706 prompt = dupprintf("%.*s", challengelen, challenge);
4708 instr_suf = dupprintf("%.*s", challengelen, challenge);
4709 prompt = dupstr("Response: ");
4711 s->cur_prompt->instruction =
4712 dupprintf("Using CryptoCard authentication.%s%s",
4713 (*instr_suf) ? "\n" : "",
4715 s->cur_prompt->instr_reqd = TRUE;
4716 add_prompt(s->cur_prompt, prompt, FALSE);
4720 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4721 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4722 bombout(("No supported authentication methods available"));
4725 s->cur_prompt->to_server = TRUE;
4726 s->cur_prompt->name = dupstr("SSH password");
4727 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4728 ssh->username, ssh->savedhost),
4733 * Show password prompt, having first obtained it via a TIS
4734 * or CryptoCard exchange if we're doing TIS or CryptoCard
4738 int ret; /* need not be kept over crReturn */
4739 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4742 crWaitUntil(!pktin);
4743 ret = get_userpass_input(s->cur_prompt, in, inlen);
4748 * Failed to get a password (for example
4749 * because one was supplied on the command line
4750 * which has already failed to work). Terminate.
4752 free_prompts(s->cur_prompt);
4753 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4758 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4760 * Defence against traffic analysis: we send a
4761 * whole bunch of packets containing strings of
4762 * different lengths. One of these strings is the
4763 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4764 * The others are all random data in
4765 * SSH1_MSG_IGNORE packets. This way a passive
4766 * listener can't tell which is the password, and
4767 * hence can't deduce the password length.
4769 * Anybody with a password length greater than 16
4770 * bytes is going to have enough entropy in their
4771 * password that a listener won't find it _that_
4772 * much help to know how long it is. So what we'll
4775 * - if password length < 16, we send 15 packets
4776 * containing string lengths 1 through 15
4778 * - otherwise, we let N be the nearest multiple
4779 * of 8 below the password length, and send 8
4780 * packets containing string lengths N through
4781 * N+7. This won't obscure the order of
4782 * magnitude of the password length, but it will
4783 * introduce a bit of extra uncertainty.
4785 * A few servers can't deal with SSH1_MSG_IGNORE, at
4786 * least in this context. For these servers, we need
4787 * an alternative defence. We make use of the fact
4788 * that the password is interpreted as a C string:
4789 * so we can append a NUL, then some random data.
4791 * A few servers can deal with neither SSH1_MSG_IGNORE
4792 * here _nor_ a padded password string.
4793 * For these servers we are left with no defences
4794 * against password length sniffing.
4796 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4797 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4799 * The server can deal with SSH1_MSG_IGNORE, so
4800 * we can use the primary defence.
4802 int bottom, top, pwlen, i;
4805 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4807 bottom = 0; /* zero length passwords are OK! :-) */
4810 bottom = pwlen & ~7;
4814 assert(pwlen >= bottom && pwlen <= top);
4816 randomstr = snewn(top + 1, char);
4818 for (i = bottom; i <= top; i++) {
4820 defer_packet(ssh, s->pwpkt_type,
4821 PKT_STR,s->cur_prompt->prompts[0]->result,
4824 for (j = 0; j < i; j++) {
4826 randomstr[j] = random_byte();
4827 } while (randomstr[j] == '\0');
4829 randomstr[i] = '\0';
4830 defer_packet(ssh, SSH1_MSG_IGNORE,
4831 PKT_STR, randomstr, PKT_END);
4834 logevent("Sending password with camouflage packets");
4835 ssh_pkt_defersend(ssh);
4838 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4840 * The server can't deal with SSH1_MSG_IGNORE
4841 * but can deal with padded passwords, so we
4842 * can use the secondary defence.
4848 len = strlen(s->cur_prompt->prompts[0]->result);
4849 if (len < sizeof(string)) {
4851 strcpy(string, s->cur_prompt->prompts[0]->result);
4852 len++; /* cover the zero byte */
4853 while (len < sizeof(string)) {
4854 string[len++] = (char) random_byte();
4857 ss = s->cur_prompt->prompts[0]->result;
4859 logevent("Sending length-padded password");
4860 send_packet(ssh, s->pwpkt_type,
4861 PKT_INT, len, PKT_DATA, ss, len,
4865 * The server is believed unable to cope with
4866 * any of our password camouflage methods.
4869 len = strlen(s->cur_prompt->prompts[0]->result);
4870 logevent("Sending unpadded password");
4871 send_packet(ssh, s->pwpkt_type,
4873 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4877 send_packet(ssh, s->pwpkt_type,
4878 PKT_STR, s->cur_prompt->prompts[0]->result,
4881 logevent("Sent password");
4882 free_prompts(s->cur_prompt);
4884 if (pktin->type == SSH1_SMSG_FAILURE) {
4885 if (flags & FLAG_VERBOSE)
4886 c_write_str(ssh, "Access denied\r\n");
4887 logevent("Authentication refused");
4888 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4889 bombout(("Strange packet received, type %d", pktin->type));
4895 if (s->publickey_blob) {
4896 sfree(s->publickey_blob);
4897 sfree(s->publickey_comment);
4900 logevent("Authentication successful");
4905 static void ssh_channel_try_eof(struct ssh_channel *c)
4908 assert(c->pending_eof); /* precondition for calling us */
4910 return; /* can't close: not even opened yet */
4911 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4912 return; /* can't send EOF: pending outgoing data */
4914 c->pending_eof = FALSE; /* we're about to send it */
4915 if (ssh->version == 1) {
4916 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4918 c->closes |= CLOSES_SENT_EOF;
4920 struct Packet *pktout;
4921 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4922 ssh2_pkt_adduint32(pktout, c->remoteid);
4923 ssh2_pkt_send(ssh, pktout);
4924 c->closes |= CLOSES_SENT_EOF;
4925 ssh2_channel_check_close(c);
4929 Conf *sshfwd_get_conf(struct ssh_channel *c)
4935 void sshfwd_write_eof(struct ssh_channel *c)
4939 if (ssh->state == SSH_STATE_CLOSED)
4942 if (c->closes & CLOSES_SENT_EOF)
4945 c->pending_eof = TRUE;
4946 ssh_channel_try_eof(c);
4949 void sshfwd_unclean_close(struct ssh_channel *c, const char *err)
4953 if (ssh->state == SSH_STATE_CLOSED)
4958 x11_close(c->u.x11.xconn);
4959 logeventf(ssh, "Forwarded X11 connection terminated due to local "
4963 case CHAN_SOCKDATA_DORMANT:
4964 pfd_close(c->u.pfd.pf);
4965 logeventf(ssh, "Forwarded port closed due to local error: %s", err);
4968 c->type = CHAN_ZOMBIE;
4969 c->pending_eof = FALSE; /* this will confuse a zombie channel */
4971 ssh2_channel_check_close(c);
4974 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
4978 if (ssh->state == SSH_STATE_CLOSED)
4981 if (ssh->version == 1) {
4982 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
4983 PKT_INT, c->remoteid,
4984 PKT_INT, len, PKT_DATA, buf, len,
4987 * In SSH-1 we can return 0 here - implying that forwarded
4988 * connections are never individually throttled - because
4989 * the only circumstance that can cause throttling will be
4990 * the whole SSH connection backing up, in which case
4991 * _everything_ will be throttled as a whole.
4995 ssh2_add_channel_data(c, buf, len);
4996 return ssh2_try_send(c);
5000 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
5005 if (ssh->state == SSH_STATE_CLOSED)
5008 if (ssh->version == 1) {
5009 buflimit = SSH1_BUFFER_LIMIT;
5011 buflimit = c->v.v2.locmaxwin;
5012 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
5014 if (c->throttling_conn && bufsize <= buflimit) {
5015 c->throttling_conn = 0;
5016 ssh_throttle_conn(ssh, -1);
5020 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
5022 struct queued_handler *qh = ssh->qhead;
5026 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
5029 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
5030 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
5033 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
5034 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
5038 ssh->qhead = qh->next;
5040 if (ssh->qhead->msg1 > 0) {
5041 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
5042 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
5044 if (ssh->qhead->msg2 > 0) {
5045 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
5046 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
5049 ssh->qhead = ssh->qtail = NULL;
5052 qh->handler(ssh, pktin, qh->ctx);
5057 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
5058 chandler_fn_t handler, void *ctx)
5060 struct queued_handler *qh;
5062 qh = snew(struct queued_handler);
5065 qh->handler = handler;
5069 if (ssh->qtail == NULL) {
5073 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
5074 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
5077 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
5078 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
5081 ssh->qtail->next = qh;
5086 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
5088 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
5090 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
5091 SSH2_MSG_REQUEST_SUCCESS)) {
5092 logeventf(ssh, "Remote port forwarding from %s enabled",
5095 logeventf(ssh, "Remote port forwarding from %s refused",
5098 rpf = del234(ssh->rportfwds, pf);
5100 pf->pfrec->remote = NULL;
5105 int ssh_alloc_sharing_rportfwd(Ssh ssh, const char *shost, int sport,
5108 struct ssh_rportfwd *pf = snew(struct ssh_rportfwd);
5111 pf->share_ctx = share_ctx;
5112 pf->shost = dupstr(shost);
5114 pf->sportdesc = NULL;
5115 if (!ssh->rportfwds) {
5116 assert(ssh->version == 2);
5117 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5119 if (add234(ssh->rportfwds, pf) != pf) {
5127 static void ssh_sharing_global_request_response(Ssh ssh, struct Packet *pktin,
5130 share_got_pkt_from_server(ctx, pktin->type,
5131 pktin->body, pktin->length);
5134 void ssh_sharing_queue_global_request(Ssh ssh, void *share_ctx)
5136 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, SSH2_MSG_REQUEST_FAILURE,
5137 ssh_sharing_global_request_response, share_ctx);
5140 static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
5142 struct ssh_portfwd *epf;
5146 if (!ssh->portfwds) {
5147 ssh->portfwds = newtree234(ssh_portcmp);
5150 * Go through the existing port forwardings and tag them
5151 * with status==DESTROY. Any that we want to keep will be
5152 * re-enabled (status==KEEP) as we go through the
5153 * configuration and find out which bits are the same as
5156 struct ssh_portfwd *epf;
5158 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5159 epf->status = DESTROY;
5162 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
5164 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
5165 char *kp, *kp2, *vp, *vp2;
5166 char address_family, type;
5167 int sport,dport,sserv,dserv;
5168 char *sports, *dports, *saddr, *host;
5172 address_family = 'A';
5174 if (*kp == 'A' || *kp == '4' || *kp == '6')
5175 address_family = *kp++;
5176 if (*kp == 'L' || *kp == 'R')
5179 if ((kp2 = host_strchr(kp, ':')) != NULL) {
5181 * There's a colon in the middle of the source port
5182 * string, which means that the part before it is
5183 * actually a source address.
5185 char *saddr_tmp = dupprintf("%.*s", (int)(kp2 - kp), kp);
5186 saddr = host_strduptrim(saddr_tmp);
5193 sport = atoi(sports);
5197 sport = net_service_lookup(sports);
5199 logeventf(ssh, "Service lookup failed for source"
5200 " port \"%s\"", sports);
5204 if (type == 'L' && !strcmp(val, "D")) {
5205 /* dynamic forwarding */
5212 /* ordinary forwarding */
5214 vp2 = vp + host_strcspn(vp, ":");
5215 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
5219 dport = atoi(dports);
5223 dport = net_service_lookup(dports);
5225 logeventf(ssh, "Service lookup failed for destination"
5226 " port \"%s\"", dports);
5231 if (sport && dport) {
5232 /* Set up a description of the source port. */
5233 struct ssh_portfwd *pfrec, *epfrec;
5235 pfrec = snew(struct ssh_portfwd);
5237 pfrec->saddr = saddr;
5238 pfrec->sserv = sserv ? dupstr(sports) : NULL;
5239 pfrec->sport = sport;
5240 pfrec->daddr = host;
5241 pfrec->dserv = dserv ? dupstr(dports) : NULL;
5242 pfrec->dport = dport;
5243 pfrec->local = NULL;
5244 pfrec->remote = NULL;
5245 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
5246 address_family == '6' ? ADDRTYPE_IPV6 :
5249 epfrec = add234(ssh->portfwds, pfrec);
5250 if (epfrec != pfrec) {
5251 if (epfrec->status == DESTROY) {
5253 * We already have a port forwarding up and running
5254 * with precisely these parameters. Hence, no need
5255 * to do anything; simply re-tag the existing one
5258 epfrec->status = KEEP;
5261 * Anything else indicates that there was a duplicate
5262 * in our input, which we'll silently ignore.
5264 free_portfwd(pfrec);
5266 pfrec->status = CREATE;
5275 * Now go through and destroy any port forwardings which were
5278 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5279 if (epf->status == DESTROY) {
5282 message = dupprintf("%s port forwarding from %s%s%d",
5283 epf->type == 'L' ? "local" :
5284 epf->type == 'R' ? "remote" : "dynamic",
5285 epf->saddr ? epf->saddr : "",
5286 epf->saddr ? ":" : "",
5289 if (epf->type != 'D') {
5290 char *msg2 = dupprintf("%s to %s:%d", message,
5291 epf->daddr, epf->dport);
5296 logeventf(ssh, "Cancelling %s", message);
5299 /* epf->remote or epf->local may be NULL if setting up a
5300 * forwarding failed. */
5302 struct ssh_rportfwd *rpf = epf->remote;
5303 struct Packet *pktout;
5306 * Cancel the port forwarding at the server
5309 if (ssh->version == 1) {
5311 * We cannot cancel listening ports on the
5312 * server side in SSH-1! There's no message
5313 * to support it. Instead, we simply remove
5314 * the rportfwd record from the local end
5315 * so that any connections the server tries
5316 * to make on it are rejected.
5319 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5320 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
5321 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
5323 ssh2_pkt_addstring(pktout, epf->saddr);
5324 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5325 /* XXX: rport_acceptall may not represent
5326 * what was used to open the original connection,
5327 * since it's reconfigurable. */
5328 ssh2_pkt_addstring(pktout, "");
5330 ssh2_pkt_addstring(pktout, "localhost");
5332 ssh2_pkt_adduint32(pktout, epf->sport);
5333 ssh2_pkt_send(ssh, pktout);
5336 del234(ssh->rportfwds, rpf);
5338 } else if (epf->local) {
5339 pfl_terminate(epf->local);
5342 delpos234(ssh->portfwds, i);
5344 i--; /* so we don't skip one in the list */
5348 * And finally, set up any new port forwardings (status==CREATE).
5350 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5351 if (epf->status == CREATE) {
5352 char *sportdesc, *dportdesc;
5353 sportdesc = dupprintf("%s%s%s%s%d%s",
5354 epf->saddr ? epf->saddr : "",
5355 epf->saddr ? ":" : "",
5356 epf->sserv ? epf->sserv : "",
5357 epf->sserv ? "(" : "",
5359 epf->sserv ? ")" : "");
5360 if (epf->type == 'D') {
5363 dportdesc = dupprintf("%s:%s%s%d%s",
5365 epf->dserv ? epf->dserv : "",
5366 epf->dserv ? "(" : "",
5368 epf->dserv ? ")" : "");
5371 if (epf->type == 'L') {
5372 char *err = pfl_listen(epf->daddr, epf->dport,
5373 epf->saddr, epf->sport,
5374 ssh, conf, &epf->local,
5375 epf->addressfamily);
5377 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
5378 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5379 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5380 sportdesc, dportdesc,
5381 err ? " failed: " : "", err ? err : "");
5384 } else if (epf->type == 'D') {
5385 char *err = pfl_listen(NULL, -1, epf->saddr, epf->sport,
5386 ssh, conf, &epf->local,
5387 epf->addressfamily);
5389 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
5390 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5391 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5393 err ? " failed: " : "", err ? err : "");
5398 struct ssh_rportfwd *pf;
5401 * Ensure the remote port forwardings tree exists.
5403 if (!ssh->rportfwds) {
5404 if (ssh->version == 1)
5405 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
5407 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5410 pf = snew(struct ssh_rportfwd);
5411 pf->share_ctx = NULL;
5412 pf->dhost = dupstr(epf->daddr);
5413 pf->dport = epf->dport;
5415 pf->shost = dupstr(epf->saddr);
5416 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5417 pf->shost = dupstr("");
5419 pf->shost = dupstr("localhost");
5421 pf->sport = epf->sport;
5422 if (add234(ssh->rportfwds, pf) != pf) {
5423 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
5424 epf->daddr, epf->dport);
5427 logeventf(ssh, "Requesting remote port %s"
5428 " forward to %s", sportdesc, dportdesc);
5430 pf->sportdesc = sportdesc;
5435 if (ssh->version == 1) {
5436 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
5437 PKT_INT, epf->sport,
5438 PKT_STR, epf->daddr,
5439 PKT_INT, epf->dport,
5441 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
5443 ssh_rportfwd_succfail, pf);
5445 struct Packet *pktout;
5446 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5447 ssh2_pkt_addstring(pktout, "tcpip-forward");
5448 ssh2_pkt_addbool(pktout, 1);/* want reply */
5449 ssh2_pkt_addstring(pktout, pf->shost);
5450 ssh2_pkt_adduint32(pktout, pf->sport);
5451 ssh2_pkt_send(ssh, pktout);
5453 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
5454 SSH2_MSG_REQUEST_FAILURE,
5455 ssh_rportfwd_succfail, pf);
5464 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
5467 int stringlen, bufsize;
5469 ssh_pkt_getstring(pktin, &string, &stringlen);
5470 if (string == NULL) {
5471 bombout(("Incoming terminal data packet was badly formed"));
5475 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
5477 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
5478 ssh->v1_stdout_throttling = 1;
5479 ssh_throttle_conn(ssh, +1);
5483 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
5485 /* Remote side is trying to open a channel to talk to our
5486 * X-Server. Give them back a local channel number. */
5487 struct ssh_channel *c;
5488 int remoteid = ssh_pkt_getuint32(pktin);
5490 logevent("Received X11 connect request");
5491 /* Refuse if X11 forwarding is disabled. */
5492 if (!ssh->X11_fwd_enabled) {
5493 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5494 PKT_INT, remoteid, PKT_END);
5495 logevent("Rejected X11 connect request");
5497 c = snew(struct ssh_channel);
5500 c->u.x11.xconn = x11_init(ssh->x11authtree, c, NULL, -1);
5501 c->remoteid = remoteid;
5502 c->halfopen = FALSE;
5503 c->localid = alloc_channel_id(ssh);
5505 c->pending_eof = FALSE;
5506 c->throttling_conn = 0;
5507 c->type = CHAN_X11; /* identify channel type */
5508 add234(ssh->channels, c);
5509 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5510 PKT_INT, c->remoteid, PKT_INT,
5511 c->localid, PKT_END);
5512 logevent("Opened X11 forward channel");
5516 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
5518 /* Remote side is trying to open a channel to talk to our
5519 * agent. Give them back a local channel number. */
5520 struct ssh_channel *c;
5521 int remoteid = ssh_pkt_getuint32(pktin);
5523 /* Refuse if agent forwarding is disabled. */
5524 if (!ssh->agentfwd_enabled) {
5525 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5526 PKT_INT, remoteid, PKT_END);
5528 c = snew(struct ssh_channel);
5530 c->remoteid = remoteid;
5531 c->halfopen = FALSE;
5532 c->localid = alloc_channel_id(ssh);
5534 c->pending_eof = FALSE;
5535 c->throttling_conn = 0;
5536 c->type = CHAN_AGENT; /* identify channel type */
5537 c->u.a.lensofar = 0;
5538 c->u.a.message = NULL;
5539 c->u.a.outstanding_requests = 0;
5540 add234(ssh->channels, c);
5541 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5542 PKT_INT, c->remoteid, PKT_INT, c->localid,
5547 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
5549 /* Remote side is trying to open a channel to talk to a
5550 * forwarded port. Give them back a local channel number. */
5551 struct ssh_rportfwd pf, *pfp;
5557 remoteid = ssh_pkt_getuint32(pktin);
5558 ssh_pkt_getstring(pktin, &host, &hostsize);
5559 port = ssh_pkt_getuint32(pktin);
5561 pf.dhost = dupprintf("%.*s", hostsize, host);
5563 pfp = find234(ssh->rportfwds, &pf, NULL);
5566 logeventf(ssh, "Rejected remote port open request for %s:%d",
5568 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5569 PKT_INT, remoteid, PKT_END);
5571 struct ssh_channel *c = snew(struct ssh_channel);
5574 logeventf(ssh, "Received remote port open request for %s:%d",
5576 err = pfd_connect(&c->u.pfd.pf, pf.dhost, port,
5577 c, ssh->conf, pfp->pfrec->addressfamily);
5579 logeventf(ssh, "Port open failed: %s", err);
5582 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5583 PKT_INT, remoteid, PKT_END);
5585 c->remoteid = remoteid;
5586 c->halfopen = FALSE;
5587 c->localid = alloc_channel_id(ssh);
5589 c->pending_eof = FALSE;
5590 c->throttling_conn = 0;
5591 c->type = CHAN_SOCKDATA; /* identify channel type */
5592 add234(ssh->channels, c);
5593 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5594 PKT_INT, c->remoteid, PKT_INT,
5595 c->localid, PKT_END);
5596 logevent("Forwarded port opened successfully");
5603 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5605 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5606 unsigned int localid = ssh_pkt_getuint32(pktin);
5607 struct ssh_channel *c;
5609 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5610 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5611 c->remoteid = localid;
5612 c->halfopen = FALSE;
5613 c->type = CHAN_SOCKDATA;
5614 c->throttling_conn = 0;
5615 pfd_confirm(c->u.pfd.pf);
5618 if (c && c->pending_eof) {
5620 * We have a pending close on this channel,
5621 * which we decided on before the server acked
5622 * the channel open. So now we know the
5623 * remoteid, we can close it again.
5625 ssh_channel_try_eof(c);
5629 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5631 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5632 struct ssh_channel *c;
5634 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5635 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5636 logevent("Forwarded connection refused by server");
5637 pfd_close(c->u.pfd.pf);
5638 del234(ssh->channels, c);
5643 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
5645 /* Remote side closes a channel. */
5646 unsigned i = ssh_pkt_getuint32(pktin);
5647 struct ssh_channel *c;
5648 c = find234(ssh->channels, &i, ssh_channelfind);
5649 if (c && !c->halfopen) {
5651 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
5652 !(c->closes & CLOSES_RCVD_EOF)) {
5654 * Received CHANNEL_CLOSE, which we translate into
5657 int send_close = FALSE;
5659 c->closes |= CLOSES_RCVD_EOF;
5664 x11_send_eof(c->u.x11.xconn);
5670 pfd_send_eof(c->u.pfd.pf);
5679 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
5680 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
5682 c->closes |= CLOSES_SENT_EOF;
5686 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
5687 !(c->closes & CLOSES_RCVD_CLOSE)) {
5689 if (!(c->closes & CLOSES_SENT_EOF)) {
5690 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
5691 " for which we never sent CHANNEL_CLOSE\n", i));
5694 c->closes |= CLOSES_RCVD_CLOSE;
5697 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
5698 !(c->closes & CLOSES_SENT_CLOSE)) {
5699 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
5700 PKT_INT, c->remoteid, PKT_END);
5701 c->closes |= CLOSES_SENT_CLOSE;
5704 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5705 ssh_channel_destroy(c);
5707 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5708 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
5709 "_CONFIRMATION", c ? "half-open" : "nonexistent",
5714 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5716 /* Data sent down one of our channels. */
5717 int i = ssh_pkt_getuint32(pktin);
5720 struct ssh_channel *c;
5722 ssh_pkt_getstring(pktin, &p, &len);
5724 c = find234(ssh->channels, &i, ssh_channelfind);
5729 bufsize = x11_send(c->u.x11.xconn, p, len);
5732 bufsize = pfd_send(c->u.pfd.pf, p, len);
5735 /* Data for an agent message. Buffer it. */
5737 if (c->u.a.lensofar < 4) {
5738 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
5739 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
5743 c->u.a.lensofar += l;
5745 if (c->u.a.lensofar == 4) {
5747 4 + GET_32BIT(c->u.a.msglen);
5748 c->u.a.message = snewn(c->u.a.totallen,
5750 memcpy(c->u.a.message, c->u.a.msglen, 4);
5752 if (c->u.a.lensofar >= 4 && len > 0) {
5754 min(c->u.a.totallen - c->u.a.lensofar,
5756 memcpy(c->u.a.message + c->u.a.lensofar, p,
5760 c->u.a.lensofar += l;
5762 if (c->u.a.lensofar == c->u.a.totallen) {
5765 c->u.a.outstanding_requests++;
5766 if (agent_query(c->u.a.message,
5769 ssh_agentf_callback, c))
5770 ssh_agentf_callback(c, reply, replylen);
5771 sfree(c->u.a.message);
5772 c->u.a.lensofar = 0;
5775 bufsize = 0; /* agent channels never back up */
5778 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5779 c->throttling_conn = 1;
5780 ssh_throttle_conn(ssh, +1);
5785 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5787 ssh->exitcode = ssh_pkt_getuint32(pktin);
5788 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5789 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5791 * In case `helpful' firewalls or proxies tack
5792 * extra human-readable text on the end of the
5793 * session which we might mistake for another
5794 * encrypted packet, we close the session once
5795 * we've sent EXIT_CONFIRMATION.
5797 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5800 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5801 static void ssh1_send_ttymode(void *data, char *mode, char *val)
5803 struct Packet *pktout = (struct Packet *)data;
5805 unsigned int arg = 0;
5806 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5807 if (i == lenof(ssh_ttymodes)) return;
5808 switch (ssh_ttymodes[i].type) {
5810 arg = ssh_tty_parse_specchar(val);
5813 arg = ssh_tty_parse_boolean(val);
5816 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5817 ssh2_pkt_addbyte(pktout, arg);
5820 int ssh_agent_forwarding_permitted(Ssh ssh)
5822 return conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists();
5825 static void do_ssh1_connection(Ssh ssh, const unsigned char *in, int inlen,
5826 struct Packet *pktin)
5828 crBegin(ssh->do_ssh1_connection_crstate);
5830 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5831 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5832 ssh1_smsg_stdout_stderr_data;
5834 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5835 ssh1_msg_channel_open_confirmation;
5836 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5837 ssh1_msg_channel_open_failure;
5838 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5839 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5840 ssh1_msg_channel_close;
5841 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5842 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5844 if (ssh_agent_forwarding_permitted(ssh)) {
5845 logevent("Requesting agent forwarding");
5846 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
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("Agent forwarding refused");
5857 logevent("Agent forwarding enabled");
5858 ssh->agentfwd_enabled = TRUE;
5859 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5863 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
5865 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5867 if (!ssh->x11disp) {
5868 /* FIXME: return an error message from x11_setup_display */
5869 logevent("X11 forwarding not enabled: unable to"
5870 " initialise X display");
5872 ssh->x11auth = x11_invent_fake_auth
5873 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
5874 ssh->x11auth->disp = ssh->x11disp;
5876 logevent("Requesting X11 forwarding");
5877 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5878 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5879 PKT_STR, ssh->x11auth->protoname,
5880 PKT_STR, ssh->x11auth->datastring,
5881 PKT_INT, ssh->x11disp->screennum,
5884 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5885 PKT_STR, ssh->x11auth->protoname,
5886 PKT_STR, ssh->x11auth->datastring,
5892 if (pktin->type != SSH1_SMSG_SUCCESS
5893 && pktin->type != SSH1_SMSG_FAILURE) {
5894 bombout(("Protocol confusion"));
5896 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5897 logevent("X11 forwarding refused");
5899 logevent("X11 forwarding enabled");
5900 ssh->X11_fwd_enabled = TRUE;
5901 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5906 ssh_setup_portfwd(ssh, ssh->conf);
5907 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5909 if (!conf_get_int(ssh->conf, CONF_nopty)) {
5911 /* Unpick the terminal-speed string. */
5912 /* XXX perhaps we should allow no speeds to be sent. */
5913 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5914 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
5915 /* Send the pty request. */
5916 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5917 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
5918 ssh_pkt_adduint32(pkt, ssh->term_height);
5919 ssh_pkt_adduint32(pkt, ssh->term_width);
5920 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5921 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5922 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
5923 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5924 ssh_pkt_adduint32(pkt, ssh->ispeed);
5925 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5926 ssh_pkt_adduint32(pkt, ssh->ospeed);
5927 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5929 ssh->state = SSH_STATE_INTERMED;
5933 if (pktin->type != SSH1_SMSG_SUCCESS
5934 && pktin->type != SSH1_SMSG_FAILURE) {
5935 bombout(("Protocol confusion"));
5937 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5938 c_write_str(ssh, "Server refused to allocate pty\r\n");
5939 ssh->editing = ssh->echoing = 1;
5941 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5942 ssh->ospeed, ssh->ispeed);
5943 ssh->got_pty = TRUE;
5946 ssh->editing = ssh->echoing = 1;
5949 if (conf_get_int(ssh->conf, CONF_compression)) {
5950 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5954 if (pktin->type != SSH1_SMSG_SUCCESS
5955 && pktin->type != SSH1_SMSG_FAILURE) {
5956 bombout(("Protocol confusion"));
5958 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5959 c_write_str(ssh, "Server refused to compress\r\n");
5961 logevent("Started compression");
5962 ssh->v1_compressing = TRUE;
5963 ssh->cs_comp_ctx = zlib_compress_init();
5964 logevent("Initialised zlib (RFC1950) compression");
5965 ssh->sc_comp_ctx = zlib_decompress_init();
5966 logevent("Initialised zlib (RFC1950) decompression");
5970 * Start the shell or command.
5972 * Special case: if the first-choice command is an SSH-2
5973 * subsystem (hence not usable here) and the second choice
5974 * exists, we fall straight back to that.
5977 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
5979 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
5980 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
5981 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
5982 ssh->fallback_cmd = TRUE;
5985 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
5987 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
5988 logevent("Started session");
5991 ssh->state = SSH_STATE_SESSION;
5992 if (ssh->size_needed)
5993 ssh_size(ssh, ssh->term_width, ssh->term_height);
5994 if (ssh->eof_needed)
5995 ssh_special(ssh, TS_EOF);
5998 ldisc_echoedit_update(ssh->ldisc); /* cause ldisc to notice changes */
6000 ssh->channels = newtree234(ssh_channelcmp);
6004 * By this point, most incoming packets are already being
6005 * handled by the dispatch table, and we need only pay
6006 * attention to the unusual ones.
6011 if (pktin->type == SSH1_SMSG_SUCCESS) {
6012 /* may be from EXEC_SHELL on some servers */
6013 } else if (pktin->type == SSH1_SMSG_FAILURE) {
6014 /* may be from EXEC_SHELL on some servers
6015 * if no pty is available or in other odd cases. Ignore */
6017 bombout(("Strange packet received: type %d", pktin->type));
6022 int len = min(inlen, 512);
6023 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
6024 PKT_INT, len, PKT_DATA, in, len,
6036 * Handle the top-level SSH-2 protocol.
6038 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
6043 ssh_pkt_getstring(pktin, &msg, &msglen);
6044 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
6047 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
6049 /* log reason code in disconnect message */
6053 ssh_pkt_getstring(pktin, &msg, &msglen);
6054 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
6057 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
6059 /* Do nothing, because we're ignoring it! Duhh. */
6062 static void ssh1_protocol_setup(Ssh ssh)
6067 * Most messages are handled by the coroutines.
6069 for (i = 0; i < 256; i++)
6070 ssh->packet_dispatch[i] = NULL;
6073 * These special message types we install handlers for.
6075 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
6076 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
6077 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
6080 static void ssh1_protocol(Ssh ssh, const void *vin, int inlen,
6081 struct Packet *pktin)
6083 const unsigned char *in = (const unsigned char *)vin;
6084 if (ssh->state == SSH_STATE_CLOSED)
6087 if (pktin && ssh->packet_dispatch[pktin->type]) {
6088 ssh->packet_dispatch[pktin->type](ssh, pktin);
6092 if (!ssh->protocol_initial_phase_done) {
6093 if (do_ssh1_login(ssh, in, inlen, pktin))
6094 ssh->protocol_initial_phase_done = TRUE;
6099 do_ssh1_connection(ssh, in, inlen, pktin);
6103 * Utility routines for decoding comma-separated strings in KEXINIT.
6105 static int first_in_commasep_string(char const *needle, char const *haystack,
6109 if (!needle || !haystack) /* protect against null pointers */
6111 needlen = strlen(needle);
6113 if (haylen >= needlen && /* haystack is long enough */
6114 !memcmp(needle, haystack, needlen) && /* initial match */
6115 (haylen == needlen || haystack[needlen] == ',')
6116 /* either , or EOS follows */
6122 static int in_commasep_string(char const *needle, char const *haystack,
6127 if (!needle || !haystack) /* protect against null pointers */
6130 * Is it at the start of the string?
6132 if (first_in_commasep_string(needle, haystack, haylen))
6135 * If not, search for the next comma and resume after that.
6136 * If no comma found, terminate.
6138 p = memchr(haystack, ',', haylen);
6140 /* + 1 to skip over comma */
6141 return in_commasep_string(needle, p + 1, haylen - (p + 1 - haystack));
6145 * Add a value to the comma-separated string at the end of the packet.
6147 static void ssh2_pkt_addstring_commasep(struct Packet *pkt, const char *data)
6149 if (pkt->length - pkt->savedpos > 0)
6150 ssh_pkt_addstring_str(pkt, ",");
6151 ssh_pkt_addstring_str(pkt, data);
6156 * SSH-2 key derivation (RFC 4253 section 7.2).
6158 static unsigned char *ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
6159 char chr, int keylen)
6161 const struct ssh_hash *h = ssh->kex->hash;
6169 /* Round up to the next multiple of hash length. */
6170 keylen_padded = ((keylen + h->hlen - 1) / h->hlen) * h->hlen;
6172 key = snewn(keylen_padded, unsigned char);
6174 /* First hlen bytes. */
6176 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6177 hash_mpint(h, s, K);
6178 h->bytes(s, H, h->hlen);
6179 h->bytes(s, &chr, 1);
6180 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
6183 /* Subsequent blocks of hlen bytes. */
6184 if (keylen_padded > h->hlen) {
6188 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6189 hash_mpint(h, s, K);
6190 h->bytes(s, H, h->hlen);
6192 for (offset = h->hlen; offset < keylen_padded; offset += h->hlen) {
6193 h->bytes(s, key + offset - h->hlen, h->hlen);
6195 h->final(s2, key + offset);
6201 /* Now clear any extra bytes of key material beyond the length
6202 * we're officially returning, because the caller won't know to
6204 if (keylen_padded > keylen)
6205 smemclr(key + keylen, keylen_padded - keylen);
6211 * Structure for constructing KEXINIT algorithm lists.
6213 #define MAXKEXLIST 16
6214 struct kexinit_algorithm {
6218 const struct ssh_kex *kex;
6221 const struct ssh_signkey *hostkey;
6223 const struct ssh2_cipher *cipher;
6227 const struct ssh_mac *mac;
6230 const struct ssh_compress *comp;
6235 * Find a slot in a KEXINIT algorithm list to use for a new algorithm.
6236 * If the algorithm is already in the list, return a pointer to its
6237 * entry, otherwise return an entry from the end of the list.
6238 * This assumes that every time a particular name is passed in, it
6239 * comes from the same string constant. If this isn't true, this
6240 * function may need to be rewritten to use strcmp() instead.
6242 static struct kexinit_algorithm *ssh2_kexinit_addalg(struct kexinit_algorithm
6243 *list, const char *name)
6247 for (i = 0; i < MAXKEXLIST; i++)
6248 if (list[i].name == NULL || list[i].name == name) {
6249 list[i].name = name;
6252 assert(!"No space in KEXINIT list");
6257 * Handle the SSH-2 transport layer.
6259 static void do_ssh2_transport(Ssh ssh, const void *vin, int inlen,
6260 struct Packet *pktin)
6262 const unsigned char *in = (const unsigned char *)vin;
6264 KEXLIST_KEX, KEXLIST_HOSTKEY, KEXLIST_CSCIPHER, KEXLIST_SCCIPHER,
6265 KEXLIST_CSMAC, KEXLIST_SCMAC, KEXLIST_CSCOMP, KEXLIST_SCCOMP,
6268 const char * kexlist_descr[NKEXLIST] = {
6269 "key exchange algorithm", "host key algorithm",
6270 "client-to-server cipher", "server-to-client cipher",
6271 "client-to-server MAC", "server-to-client MAC",
6272 "client-to-server compression method",
6273 "server-to-client compression method" };
6274 struct do_ssh2_transport_state {
6276 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
6277 Bignum p, g, e, f, K;
6280 int kex_init_value, kex_reply_value;
6281 const struct ssh_mac **maclist;
6283 const struct ssh2_cipher *cscipher_tobe;
6284 const struct ssh2_cipher *sccipher_tobe;
6285 const struct ssh_mac *csmac_tobe;
6286 const struct ssh_mac *scmac_tobe;
6287 int csmac_etm_tobe, scmac_etm_tobe;
6288 const struct ssh_compress *cscomp_tobe;
6289 const struct ssh_compress *sccomp_tobe;
6290 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
6291 int hostkeylen, siglen, rsakeylen;
6292 void *hkey; /* actual host key */
6293 void *rsakey; /* for RSA kex */
6294 void *eckey; /* for ECDH kex */
6295 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
6296 int n_preferred_kex;
6297 const struct ssh_kexes *preferred_kex[KEX_MAX];
6298 int n_preferred_ciphers;
6299 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
6300 const struct ssh_compress *preferred_comp;
6301 int userauth_succeeded; /* for delayed compression */
6302 int pending_compression;
6303 int got_session_id, activated_authconn;
6304 struct Packet *pktout;
6308 struct kexinit_algorithm kexlists[NKEXLIST][MAXKEXLIST];
6310 crState(do_ssh2_transport_state);
6312 assert(!ssh->bare_connection);
6316 s->cscipher_tobe = s->sccipher_tobe = NULL;
6317 s->csmac_tobe = s->scmac_tobe = NULL;
6318 s->cscomp_tobe = s->sccomp_tobe = NULL;
6320 s->got_session_id = s->activated_authconn = FALSE;
6321 s->userauth_succeeded = FALSE;
6322 s->pending_compression = FALSE;
6325 * Be prepared to work around the buggy MAC problem.
6327 if (ssh->remote_bugs & BUG_SSH2_HMAC)
6328 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
6330 s->maclist = macs, s->nmacs = lenof(macs);
6333 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
6336 struct kexinit_algorithm *alg;
6339 * Set up the preferred key exchange. (NULL => warn below here)
6341 s->n_preferred_kex = 0;
6342 for (i = 0; i < KEX_MAX; i++) {
6343 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
6345 s->preferred_kex[s->n_preferred_kex++] =
6346 &ssh_diffiehellman_gex;
6349 s->preferred_kex[s->n_preferred_kex++] =
6350 &ssh_diffiehellman_group14;
6353 s->preferred_kex[s->n_preferred_kex++] =
6354 &ssh_diffiehellman_group1;
6357 s->preferred_kex[s->n_preferred_kex++] =
6361 s->preferred_kex[s->n_preferred_kex++] =
6365 /* Flag for later. Don't bother if it's the last in
6367 if (i < KEX_MAX - 1) {
6368 s->preferred_kex[s->n_preferred_kex++] = NULL;
6375 * Set up the preferred ciphers. (NULL => warn below here)
6377 s->n_preferred_ciphers = 0;
6378 for (i = 0; i < CIPHER_MAX; i++) {
6379 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
6380 case CIPHER_BLOWFISH:
6381 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
6384 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
6385 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
6389 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
6392 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
6394 case CIPHER_ARCFOUR:
6395 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
6397 case CIPHER_CHACHA20:
6398 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_ccp;
6401 /* Flag for later. Don't bother if it's the last in
6403 if (i < CIPHER_MAX - 1) {
6404 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
6411 * Set up preferred compression.
6413 if (conf_get_int(ssh->conf, CONF_compression))
6414 s->preferred_comp = &ssh_zlib;
6416 s->preferred_comp = &ssh_comp_none;
6419 * Enable queueing of outgoing auth- or connection-layer
6420 * packets while we are in the middle of a key exchange.
6422 ssh->queueing = TRUE;
6425 * Flag that KEX is in progress.
6427 ssh->kex_in_progress = TRUE;
6429 for (i = 0; i < NKEXLIST; i++)
6430 for (j = 0; j < MAXKEXLIST; j++)
6431 s->kexlists[i][j].name = NULL;
6432 /* List key exchange algorithms. */
6434 for (i = 0; i < s->n_preferred_kex; i++) {
6435 const struct ssh_kexes *k = s->preferred_kex[i];
6436 if (!k) warn = TRUE;
6437 else for (j = 0; j < k->nkexes; j++) {
6438 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_KEX],
6440 alg->u.kex.kex = k->list[j];
6441 alg->u.kex.warn = warn;
6444 /* List server host key algorithms. */
6445 if (!s->got_session_id) {
6447 * In the first key exchange, we list all the algorithms
6448 * we're prepared to cope with, but prefer those algorithms
6449 * for which we have a host key for this host.
6451 for (i = 0; i < lenof(hostkey_algs); i++) {
6452 if (have_ssh_host_key(ssh->savedhost, ssh->savedport,
6453 hostkey_algs[i]->keytype)) {
6454 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY],
6455 hostkey_algs[i]->name);
6456 alg->u.hostkey = hostkey_algs[i];
6459 for (i = 0; i < lenof(hostkey_algs); i++) {
6460 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY],
6461 hostkey_algs[i]->name);
6462 alg->u.hostkey = hostkey_algs[i];
6466 * In subsequent key exchanges, we list only the kex
6467 * algorithm that was selected in the first key exchange,
6468 * so that we keep getting the same host key and hence
6469 * don't have to interrupt the user's session to ask for
6473 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY],
6474 ssh->hostkey->name);
6475 alg->u.hostkey = ssh->hostkey;
6477 /* List encryption algorithms (client->server then server->client). */
6478 for (k = KEXLIST_CSCIPHER; k <= KEXLIST_SCCIPHER; k++) {
6480 for (i = 0; i < s->n_preferred_ciphers; i++) {
6481 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6482 if (!c) warn = TRUE;
6483 else for (j = 0; j < c->nciphers; j++) {
6484 alg = ssh2_kexinit_addalg(s->kexlists[k],
6486 alg->u.cipher.cipher = c->list[j];
6487 alg->u.cipher.warn = warn;
6491 /* List MAC algorithms (client->server then server->client). */
6492 for (j = KEXLIST_CSMAC; j <= KEXLIST_SCMAC; j++) {
6493 for (i = 0; i < s->nmacs; i++) {
6494 alg = ssh2_kexinit_addalg(s->kexlists[j], s->maclist[i]->name);
6495 alg->u.mac.mac = s->maclist[i];
6496 alg->u.mac.etm = FALSE;
6498 for (i = 0; i < s->nmacs; i++)
6499 /* For each MAC, there may also be an ETM version,
6500 * which we list second. */
6501 if (s->maclist[i]->etm_name) {
6502 alg = ssh2_kexinit_addalg(s->kexlists[j],
6503 s->maclist[i]->etm_name);
6504 alg->u.mac.mac = s->maclist[i];
6505 alg->u.mac.etm = TRUE;
6508 /* List client->server compression algorithms,
6509 * then server->client compression algorithms. (We use the
6510 * same set twice.) */
6511 for (j = KEXLIST_CSCOMP; j <= KEXLIST_SCCOMP; j++) {
6512 assert(lenof(compressions) > 1);
6513 /* Prefer non-delayed versions */
6514 alg = ssh2_kexinit_addalg(s->kexlists[j], s->preferred_comp->name);
6515 alg->u.comp = s->preferred_comp;
6516 /* We don't even list delayed versions of algorithms until
6517 * they're allowed to be used, to avoid a race. See the end of
6519 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
6520 alg = ssh2_kexinit_addalg(s->kexlists[j],
6521 s->preferred_comp->delayed_name);
6522 alg->u.comp = s->preferred_comp;
6524 for (i = 0; i < lenof(compressions); i++) {
6525 const struct ssh_compress *c = compressions[i];
6526 alg = ssh2_kexinit_addalg(s->kexlists[j], c->name);
6528 if (s->userauth_succeeded && c->delayed_name) {
6529 alg = ssh2_kexinit_addalg(s->kexlists[j], c->delayed_name);
6535 * Construct and send our key exchange packet.
6537 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
6538 for (i = 0; i < 16; i++)
6539 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
6540 for (i = 0; i < NKEXLIST; i++) {
6541 ssh2_pkt_addstring_start(s->pktout);
6542 for (j = 0; j < MAXKEXLIST; j++) {
6543 if (s->kexlists[i][j].name == NULL) break;
6544 ssh2_pkt_addstring_commasep(s->pktout, s->kexlists[i][j].name);
6547 /* List client->server languages. Empty list. */
6548 ssh2_pkt_addstring_start(s->pktout);
6549 /* List server->client languages. Empty list. */
6550 ssh2_pkt_addstring_start(s->pktout);
6551 /* First KEX packet does _not_ follow, because we're not that brave. */
6552 ssh2_pkt_addbool(s->pktout, FALSE);
6554 ssh2_pkt_adduint32(s->pktout, 0);
6557 s->our_kexinitlen = s->pktout->length - 5;
6558 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
6559 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
6561 ssh2_pkt_send_noqueue(ssh, s->pktout);
6564 crWaitUntilV(pktin);
6567 * Now examine the other side's KEXINIT to see what we're up
6574 if (pktin->type != SSH2_MSG_KEXINIT) {
6575 bombout(("expected key exchange packet from server"));
6579 ssh->hostkey = NULL;
6580 s->cscipher_tobe = NULL;
6581 s->sccipher_tobe = NULL;
6582 s->csmac_tobe = NULL;
6583 s->scmac_tobe = NULL;
6584 s->cscomp_tobe = NULL;
6585 s->sccomp_tobe = NULL;
6586 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
6588 pktin->savedpos += 16; /* skip garbage cookie */
6591 for (i = 0; i < NKEXLIST; i++) {
6592 ssh_pkt_getstring(pktin, &str, &len);
6594 bombout(("KEXINIT packet was incomplete"));
6598 /* If we've already selected a cipher which requires a
6599 * particular MAC, then just select that, and don't even
6600 * bother looking through the server's KEXINIT string for
6602 if (i == KEXLIST_CSMAC && s->cscipher_tobe &&
6603 s->cscipher_tobe->required_mac) {
6604 s->csmac_tobe = s->cscipher_tobe->required_mac;
6605 s->csmac_etm_tobe = !!(s->csmac_tobe->etm_name);
6608 if (i == KEXLIST_SCMAC && s->sccipher_tobe &&
6609 s->sccipher_tobe->required_mac) {
6610 s->scmac_tobe = s->sccipher_tobe->required_mac;
6611 s->scmac_etm_tobe = !!(s->scmac_tobe->etm_name);
6615 for (j = 0; j < MAXKEXLIST; j++) {
6616 struct kexinit_algorithm *alg = &s->kexlists[i][j];
6617 if (alg->name == NULL) break;
6618 if (in_commasep_string(alg->name, str, len)) {
6619 /* We've found a matching algorithm. */
6620 if (i == KEXLIST_KEX || i == KEXLIST_HOSTKEY) {
6621 /* Check if we might need to ignore first kex pkt */
6623 !first_in_commasep_string(alg->name, str, len))
6626 if (i == KEXLIST_KEX) {
6627 ssh->kex = alg->u.kex.kex;
6628 s->warn_kex = alg->u.kex.warn;
6629 } else if (i == KEXLIST_HOSTKEY) {
6630 ssh->hostkey = alg->u.hostkey;
6631 } else if (i == KEXLIST_CSCIPHER) {
6632 s->cscipher_tobe = alg->u.cipher.cipher;
6633 s->warn_cscipher = alg->u.cipher.warn;
6634 } else if (i == KEXLIST_SCCIPHER) {
6635 s->sccipher_tobe = alg->u.cipher.cipher;
6636 s->warn_sccipher = alg->u.cipher.warn;
6637 } else if (i == KEXLIST_CSMAC) {
6638 s->csmac_tobe = alg->u.mac.mac;
6639 s->csmac_etm_tobe = alg->u.mac.etm;
6640 } else if (i == KEXLIST_SCMAC) {
6641 s->scmac_tobe = alg->u.mac.mac;
6642 s->scmac_etm_tobe = alg->u.mac.etm;
6643 } else if (i == KEXLIST_CSCOMP) {
6644 s->cscomp_tobe = alg->u.comp;
6645 } else if (i == KEXLIST_SCCOMP) {
6646 s->sccomp_tobe = alg->u.comp;
6650 if ((i == KEXLIST_CSCOMP || i == KEXLIST_SCCOMP) &&
6651 in_commasep_string(alg->u.comp->delayed_name, str, len))
6652 s->pending_compression = TRUE; /* try this later */
6654 bombout(("Couldn't agree a %s ((available: %.*s)",
6655 kexlist_descr[i], len, str));
6660 if (s->pending_compression) {
6661 logevent("Server supports delayed compression; "
6662 "will try this later");
6664 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
6665 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
6666 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
6668 ssh->exhash = ssh->kex->hash->init();
6669 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
6670 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
6671 hash_string(ssh->kex->hash, ssh->exhash,
6672 s->our_kexinit, s->our_kexinitlen);
6673 sfree(s->our_kexinit);
6674 /* Include the type byte in the hash of server's KEXINIT */
6675 hash_string(ssh->kex->hash, ssh->exhash,
6676 pktin->body - 1, pktin->length + 1);
6679 ssh_set_frozen(ssh, 1);
6680 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
6682 ssh_dialog_callback, ssh);
6683 if (s->dlgret < 0) {
6687 bombout(("Unexpected data from server while"
6688 " waiting for user response"));
6691 } while (pktin || inlen > 0);
6692 s->dlgret = ssh->user_response;
6694 ssh_set_frozen(ssh, 0);
6695 if (s->dlgret == 0) {
6696 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
6702 if (s->warn_cscipher) {
6703 ssh_set_frozen(ssh, 1);
6704 s->dlgret = askalg(ssh->frontend,
6705 "client-to-server cipher",
6706 s->cscipher_tobe->name,
6707 ssh_dialog_callback, ssh);
6708 if (s->dlgret < 0) {
6712 bombout(("Unexpected data from server while"
6713 " waiting for user response"));
6716 } while (pktin || inlen > 0);
6717 s->dlgret = ssh->user_response;
6719 ssh_set_frozen(ssh, 0);
6720 if (s->dlgret == 0) {
6721 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6727 if (s->warn_sccipher) {
6728 ssh_set_frozen(ssh, 1);
6729 s->dlgret = askalg(ssh->frontend,
6730 "server-to-client cipher",
6731 s->sccipher_tobe->name,
6732 ssh_dialog_callback, ssh);
6733 if (s->dlgret < 0) {
6737 bombout(("Unexpected data from server while"
6738 " waiting for user response"));
6741 } while (pktin || inlen > 0);
6742 s->dlgret = ssh->user_response;
6744 ssh_set_frozen(ssh, 0);
6745 if (s->dlgret == 0) {
6746 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6752 if (s->ignorepkt) /* first_kex_packet_follows */
6753 crWaitUntilV(pktin); /* Ignore packet */
6756 if (ssh->kex->main_type == KEXTYPE_DH) {
6758 * Work out the number of bits of key we will need from the
6759 * key exchange. We start with the maximum key length of
6765 csbits = s->cscipher_tobe->real_keybits;
6766 scbits = s->sccipher_tobe->real_keybits;
6767 s->nbits = (csbits > scbits ? csbits : scbits);
6769 /* The keys only have hlen-bit entropy, since they're based on
6770 * a hash. So cap the key size at hlen bits. */
6771 if (s->nbits > ssh->kex->hash->hlen * 8)
6772 s->nbits = ssh->kex->hash->hlen * 8;
6775 * If we're doing Diffie-Hellman group exchange, start by
6776 * requesting a group.
6778 if (dh_is_gex(ssh->kex)) {
6779 logevent("Doing Diffie-Hellman group exchange");
6780 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
6782 * Work out how big a DH group we will need to allow that
6785 s->pbits = 512 << ((s->nbits - 1) / 64);
6786 if (s->pbits < DH_MIN_SIZE)
6787 s->pbits = DH_MIN_SIZE;
6788 if (s->pbits > DH_MAX_SIZE)
6789 s->pbits = DH_MAX_SIZE;
6790 if ((ssh->remote_bugs & BUG_SSH2_OLDGEX)) {
6791 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST_OLD);
6792 ssh2_pkt_adduint32(s->pktout, s->pbits);
6794 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6795 ssh2_pkt_adduint32(s->pktout, DH_MIN_SIZE);
6796 ssh2_pkt_adduint32(s->pktout, s->pbits);
6797 ssh2_pkt_adduint32(s->pktout, DH_MAX_SIZE);
6799 ssh2_pkt_send_noqueue(ssh, s->pktout);
6801 crWaitUntilV(pktin);
6802 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6803 bombout(("expected key exchange group packet from server"));
6806 s->p = ssh2_pkt_getmp(pktin);
6807 s->g = ssh2_pkt_getmp(pktin);
6808 if (!s->p || !s->g) {
6809 bombout(("unable to read mp-ints from incoming group packet"));
6812 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6813 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6814 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6816 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
6817 ssh->kex_ctx = dh_setup_group(ssh->kex);
6818 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6819 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6820 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6821 ssh->kex->groupname);
6824 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6825 ssh->kex->hash->text_name);
6827 * Now generate and send e for Diffie-Hellman.
6829 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6830 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6831 s->pktout = ssh2_pkt_init(s->kex_init_value);
6832 ssh2_pkt_addmp(s->pktout, s->e);
6833 ssh2_pkt_send_noqueue(ssh, s->pktout);
6835 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
6836 crWaitUntilV(pktin);
6837 if (pktin->type != s->kex_reply_value) {
6838 bombout(("expected key exchange reply packet from server"));
6841 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
6842 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6843 if (!s->hostkeydata) {
6844 bombout(("unable to parse key exchange reply packet"));
6847 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
6848 s->hostkeydata, s->hostkeylen);
6849 s->f = ssh2_pkt_getmp(pktin);
6851 bombout(("unable to parse key exchange reply packet"));
6854 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6856 bombout(("unable to parse key exchange reply packet"));
6861 const char *err = dh_validate_f(ssh->kex_ctx, s->f);
6863 bombout(("key exchange reply failed validation: %s", err));
6867 s->K = dh_find_K(ssh->kex_ctx, s->f);
6869 /* We assume everything from now on will be quick, and it might
6870 * involve user interaction. */
6871 set_busy_status(ssh->frontend, BUSY_NOT);
6873 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6874 if (dh_is_gex(ssh->kex)) {
6875 if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX))
6876 hash_uint32(ssh->kex->hash, ssh->exhash, DH_MIN_SIZE);
6877 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
6878 if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX))
6879 hash_uint32(ssh->kex->hash, ssh->exhash, DH_MAX_SIZE);
6880 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
6881 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
6883 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
6884 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
6886 dh_cleanup(ssh->kex_ctx);
6888 if (dh_is_gex(ssh->kex)) {
6892 } else if (ssh->kex->main_type == KEXTYPE_ECDH) {
6894 logeventf(ssh, "Doing ECDH key exchange with curve %s and hash %s",
6895 ssh_ecdhkex_curve_textname(ssh->kex),
6896 ssh->kex->hash->text_name);
6897 ssh->pkt_kctx = SSH2_PKTCTX_ECDHKEX;
6899 s->eckey = ssh_ecdhkex_newkey(ssh->kex);
6901 bombout(("Unable to generate key for ECDH"));
6907 int publicPointLength;
6908 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
6910 ssh_ecdhkex_freekey(s->eckey);
6911 bombout(("Unable to encode public key for ECDH"));
6914 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_ECDH_INIT);
6915 ssh2_pkt_addstring_start(s->pktout);
6916 ssh2_pkt_addstring_data(s->pktout, publicPoint, publicPointLength);
6920 ssh2_pkt_send_noqueue(ssh, s->pktout);
6922 crWaitUntilV(pktin);
6923 if (pktin->type != SSH2_MSG_KEX_ECDH_REPLY) {
6924 ssh_ecdhkex_freekey(s->eckey);
6925 bombout(("expected ECDH reply packet from server"));
6929 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6930 if (!s->hostkeydata) {
6931 bombout(("unable to parse ECDH reply packet"));
6934 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6935 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
6936 s->hostkeydata, s->hostkeylen);
6940 int publicPointLength;
6941 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
6943 ssh_ecdhkex_freekey(s->eckey);
6944 bombout(("Unable to encode public key for ECDH hash"));
6947 hash_string(ssh->kex->hash, ssh->exhash,
6948 publicPoint, publicPointLength);
6955 ssh_pkt_getstring(pktin, &keydata, &keylen);
6957 bombout(("unable to parse ECDH reply packet"));
6960 hash_string(ssh->kex->hash, ssh->exhash, keydata, keylen);
6961 s->K = ssh_ecdhkex_getkey(s->eckey, keydata, keylen);
6963 ssh_ecdhkex_freekey(s->eckey);
6964 bombout(("point received in ECDH was not valid"));
6969 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6971 bombout(("unable to parse key exchange reply packet"));
6975 ssh_ecdhkex_freekey(s->eckey);
6977 logeventf(ssh, "Doing RSA key exchange with hash %s",
6978 ssh->kex->hash->text_name);
6979 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
6981 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6984 crWaitUntilV(pktin);
6985 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
6986 bombout(("expected RSA public key packet from server"));
6990 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6991 if (!s->hostkeydata) {
6992 bombout(("unable to parse RSA public key packet"));
6995 hash_string(ssh->kex->hash, ssh->exhash,
6996 s->hostkeydata, s->hostkeylen);
6997 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
6998 s->hostkeydata, s->hostkeylen);
7002 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
7004 bombout(("unable to parse RSA public key packet"));
7007 s->rsakeydata = snewn(s->rsakeylen, char);
7008 memcpy(s->rsakeydata, keydata, s->rsakeylen);
7011 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
7013 sfree(s->rsakeydata);
7014 bombout(("unable to parse RSA public key from server"));
7018 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
7021 * Next, set up a shared secret K, of precisely KLEN -
7022 * 2*HLEN - 49 bits, where KLEN is the bit length of the
7023 * RSA key modulus and HLEN is the bit length of the hash
7027 int klen = ssh_rsakex_klen(s->rsakey);
7028 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
7030 unsigned char *kstr1, *kstr2, *outstr;
7031 int kstr1len, kstr2len, outstrlen;
7033 s->K = bn_power_2(nbits - 1);
7035 for (i = 0; i < nbits; i++) {
7037 byte = random_byte();
7039 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
7043 * Encode this as an mpint.
7045 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
7046 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
7047 PUT_32BIT(kstr2, kstr1len);
7048 memcpy(kstr2 + 4, kstr1, kstr1len);
7051 * Encrypt it with the given RSA key.
7053 outstrlen = (klen + 7) / 8;
7054 outstr = snewn(outstrlen, unsigned char);
7055 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
7056 outstr, outstrlen, s->rsakey);
7059 * And send it off in a return packet.
7061 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
7062 ssh2_pkt_addstring_start(s->pktout);
7063 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
7064 ssh2_pkt_send_noqueue(ssh, s->pktout);
7066 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
7073 ssh_rsakex_freekey(s->rsakey);
7075 crWaitUntilV(pktin);
7076 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
7077 sfree(s->rsakeydata);
7078 bombout(("expected signature packet from server"));
7082 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
7084 bombout(("unable to parse signature packet"));
7088 sfree(s->rsakeydata);
7091 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
7092 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
7093 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
7095 ssh->kex_ctx = NULL;
7098 debug(("Exchange hash is:\n"));
7099 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
7103 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
7104 (char *)s->exchange_hash,
7105 ssh->kex->hash->hlen)) {
7106 bombout(("Server's host key did not match the signature supplied"));
7110 s->keystr = ssh->hostkey->fmtkey(s->hkey);
7111 if (!s->got_session_id) {
7113 * Authenticate remote host: verify host key. (We've already
7114 * checked the signature of the exchange hash.)
7116 s->fingerprint = ssh2_fingerprint(ssh->hostkey, s->hkey);
7117 logevent("Host key fingerprint is:");
7118 logevent(s->fingerprint);
7119 /* First check against manually configured host keys. */
7120 s->dlgret = verify_ssh_manual_host_key(ssh, s->fingerprint,
7121 ssh->hostkey, s->hkey);
7122 if (s->dlgret == 0) { /* did not match */
7123 bombout(("Host key did not appear in manually configured list"));
7125 } else if (s->dlgret < 0) { /* none configured; use standard handling */
7126 ssh_set_frozen(ssh, 1);
7127 s->dlgret = verify_ssh_host_key(ssh->frontend,
7128 ssh->savedhost, ssh->savedport,
7129 ssh->hostkey->keytype, s->keystr,
7131 ssh_dialog_callback, ssh);
7132 if (s->dlgret < 0) {
7136 bombout(("Unexpected data from server while waiting"
7137 " for user host key response"));
7140 } while (pktin || inlen > 0);
7141 s->dlgret = ssh->user_response;
7143 ssh_set_frozen(ssh, 0);
7144 if (s->dlgret == 0) {
7145 ssh_disconnect(ssh, "Aborted at host key verification", NULL,
7150 sfree(s->fingerprint);
7152 * Save this host key, to check against the one presented in
7153 * subsequent rekeys.
7155 ssh->hostkey_str = s->keystr;
7158 * In a rekey, we never present an interactive host key
7159 * verification request to the user. Instead, we simply
7160 * enforce that the key we're seeing this time is identical to
7161 * the one we saw before.
7163 if (strcmp(ssh->hostkey_str, s->keystr)) {
7164 bombout(("Host key was different in repeat key exchange"));
7169 ssh->hostkey->freekey(s->hkey);
7172 * The exchange hash from the very first key exchange is also
7173 * the session id, used in session key construction and
7176 if (!s->got_session_id) {
7177 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
7178 memcpy(ssh->v2_session_id, s->exchange_hash,
7179 sizeof(s->exchange_hash));
7180 ssh->v2_session_id_len = ssh->kex->hash->hlen;
7181 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
7182 s->got_session_id = TRUE;
7186 * Send SSH2_MSG_NEWKEYS.
7188 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
7189 ssh2_pkt_send_noqueue(ssh, s->pktout);
7190 ssh->outgoing_data_size = 0; /* start counting from here */
7193 * We've sent client NEWKEYS, so create and initialise
7194 * client-to-server session keys.
7196 if (ssh->cs_cipher_ctx)
7197 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7198 ssh->cscipher = s->cscipher_tobe;
7199 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
7201 if (ssh->cs_mac_ctx)
7202 ssh->csmac->free_context(ssh->cs_mac_ctx);
7203 ssh->csmac = s->csmac_tobe;
7204 ssh->csmac_etm = s->csmac_etm_tobe;
7205 ssh->cs_mac_ctx = ssh->csmac->make_context(ssh->cs_cipher_ctx);
7207 if (ssh->cs_comp_ctx)
7208 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7209 ssh->cscomp = s->cscomp_tobe;
7210 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
7213 * Set IVs on client-to-server keys. Here we use the exchange
7214 * hash from the _first_ key exchange.
7219 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'C',
7220 ssh->cscipher->padded_keybytes);
7221 ssh->cscipher->setkey(ssh->cs_cipher_ctx, key);
7222 smemclr(key, ssh->cscipher->padded_keybytes);
7225 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'A',
7226 ssh->cscipher->blksize);
7227 ssh->cscipher->setiv(ssh->cs_cipher_ctx, key);
7228 smemclr(key, ssh->cscipher->blksize);
7231 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'E',
7232 ssh->csmac->keylen);
7233 ssh->csmac->setkey(ssh->cs_mac_ctx, key);
7234 smemclr(key, ssh->csmac->keylen);
7238 logeventf(ssh, "Initialised %.200s client->server encryption",
7239 ssh->cscipher->text_name);
7240 logeventf(ssh, "Initialised %.200s client->server MAC algorithm%s%s",
7241 ssh->csmac->text_name,
7242 ssh->csmac_etm ? " (in ETM mode)" : "",
7243 ssh->cscipher->required_mac ? " (required by cipher)" : "");
7244 if (ssh->cscomp->text_name)
7245 logeventf(ssh, "Initialised %s compression",
7246 ssh->cscomp->text_name);
7249 * Now our end of the key exchange is complete, we can send all
7250 * our queued higher-layer packets.
7252 ssh->queueing = FALSE;
7253 ssh2_pkt_queuesend(ssh);
7256 * Expect SSH2_MSG_NEWKEYS from server.
7258 crWaitUntilV(pktin);
7259 if (pktin->type != SSH2_MSG_NEWKEYS) {
7260 bombout(("expected new-keys packet from server"));
7263 ssh->incoming_data_size = 0; /* start counting from here */
7266 * We've seen server NEWKEYS, so create and initialise
7267 * server-to-client session keys.
7269 if (ssh->sc_cipher_ctx)
7270 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7271 ssh->sccipher = s->sccipher_tobe;
7272 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
7274 if (ssh->sc_mac_ctx)
7275 ssh->scmac->free_context(ssh->sc_mac_ctx);
7276 ssh->scmac = s->scmac_tobe;
7277 ssh->scmac_etm = s->scmac_etm_tobe;
7278 ssh->sc_mac_ctx = ssh->scmac->make_context(ssh->sc_cipher_ctx);
7280 if (ssh->sc_comp_ctx)
7281 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7282 ssh->sccomp = s->sccomp_tobe;
7283 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
7286 * Set IVs on server-to-client keys. Here we use the exchange
7287 * hash from the _first_ key exchange.
7292 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'D',
7293 ssh->sccipher->padded_keybytes);
7294 ssh->sccipher->setkey(ssh->sc_cipher_ctx, key);
7295 smemclr(key, ssh->sccipher->padded_keybytes);
7298 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'B',
7299 ssh->sccipher->blksize);
7300 ssh->sccipher->setiv(ssh->sc_cipher_ctx, key);
7301 smemclr(key, ssh->sccipher->blksize);
7304 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'F',
7305 ssh->scmac->keylen);
7306 ssh->scmac->setkey(ssh->sc_mac_ctx, key);
7307 smemclr(key, ssh->scmac->keylen);
7310 logeventf(ssh, "Initialised %.200s server->client encryption",
7311 ssh->sccipher->text_name);
7312 logeventf(ssh, "Initialised %.200s server->client MAC algorithm%s%s",
7313 ssh->scmac->text_name,
7314 ssh->scmac_etm ? " (in ETM mode)" : "",
7315 ssh->sccipher->required_mac ? " (required by cipher)" : "");
7316 if (ssh->sccomp->text_name)
7317 logeventf(ssh, "Initialised %s decompression",
7318 ssh->sccomp->text_name);
7321 * Free shared secret.
7326 * Key exchange is over. Loop straight back round if we have a
7327 * deferred rekey reason.
7329 if (ssh->deferred_rekey_reason) {
7330 logevent(ssh->deferred_rekey_reason);
7332 ssh->deferred_rekey_reason = NULL;
7333 goto begin_key_exchange;
7337 * Otherwise, schedule a timer for our next rekey.
7339 ssh->kex_in_progress = FALSE;
7340 ssh->last_rekey = GETTICKCOUNT();
7341 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
7342 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7346 * Now we're encrypting. Begin returning 1 to the protocol main
7347 * function so that other things can run on top of the
7348 * transport. If we ever see a KEXINIT, we must go back to the
7351 * We _also_ go back to the start if we see pktin==NULL and
7352 * inlen negative, because this is a special signal meaning
7353 * `initiate client-driven rekey', and `in' contains a message
7354 * giving the reason for the rekey.
7356 * inlen==-1 means always initiate a rekey;
7357 * inlen==-2 means that userauth has completed successfully and
7358 * we should consider rekeying (for delayed compression).
7360 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
7361 (!pktin && inlen < 0))) {
7363 if (!ssh->protocol_initial_phase_done) {
7364 ssh->protocol_initial_phase_done = TRUE;
7366 * Allow authconn to initialise itself.
7368 do_ssh2_authconn(ssh, NULL, 0, NULL);
7373 logevent("Server initiated key re-exchange");
7377 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
7378 * delayed compression, if it's available.
7380 * draft-miller-secsh-compression-delayed-00 says that you
7381 * negotiate delayed compression in the first key exchange, and
7382 * both sides start compressing when the server has sent
7383 * USERAUTH_SUCCESS. This has a race condition -- the server
7384 * can't know when the client has seen it, and thus which incoming
7385 * packets it should treat as compressed.
7387 * Instead, we do the initial key exchange without offering the
7388 * delayed methods, but note if the server offers them; when we
7389 * get here, if a delayed method was available that was higher
7390 * on our list than what we got, we initiate a rekey in which we
7391 * _do_ list the delayed methods (and hopefully get it as a
7392 * result). Subsequent rekeys will do the same.
7394 assert(!s->userauth_succeeded); /* should only happen once */
7395 s->userauth_succeeded = TRUE;
7396 if (!s->pending_compression)
7397 /* Can't see any point rekeying. */
7398 goto wait_for_rekey; /* this is utterly horrid */
7399 /* else fall through to rekey... */
7400 s->pending_compression = FALSE;
7403 * Now we've decided to rekey.
7405 * Special case: if the server bug is set that doesn't
7406 * allow rekeying, we give a different log message and
7407 * continue waiting. (If such a server _initiates_ a rekey,
7408 * we process it anyway!)
7410 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
7411 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
7413 /* Reset the counters, so that at least this message doesn't
7414 * hit the event log _too_ often. */
7415 ssh->outgoing_data_size = 0;
7416 ssh->incoming_data_size = 0;
7417 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
7419 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7422 goto wait_for_rekey; /* this is still utterly horrid */
7424 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
7427 goto begin_key_exchange;
7433 * Add data to an SSH-2 channel output buffer.
7435 static void ssh2_add_channel_data(struct ssh_channel *c, const char *buf,
7438 bufchain_add(&c->v.v2.outbuffer, buf, len);
7442 * Attempt to send data on an SSH-2 channel.
7444 static int ssh2_try_send(struct ssh_channel *c)
7447 struct Packet *pktout;
7450 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
7453 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
7454 if ((unsigned)len > c->v.v2.remwindow)
7455 len = c->v.v2.remwindow;
7456 if ((unsigned)len > c->v.v2.remmaxpkt)
7457 len = c->v.v2.remmaxpkt;
7458 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
7459 ssh2_pkt_adduint32(pktout, c->remoteid);
7460 ssh2_pkt_addstring_start(pktout);
7461 ssh2_pkt_addstring_data(pktout, data, len);
7462 ssh2_pkt_send(ssh, pktout);
7463 bufchain_consume(&c->v.v2.outbuffer, len);
7464 c->v.v2.remwindow -= len;
7468 * After having sent as much data as we can, return the amount
7471 ret = bufchain_size(&c->v.v2.outbuffer);
7474 * And if there's no data pending but we need to send an EOF, send
7477 if (!ret && c->pending_eof)
7478 ssh_channel_try_eof(c);
7483 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
7486 if (c->closes & CLOSES_SENT_EOF)
7487 return; /* don't send on channels we've EOFed */
7488 bufsize = ssh2_try_send(c);
7491 case CHAN_MAINSESSION:
7492 /* stdin need not receive an unthrottle
7493 * notification since it will be polled */
7496 x11_unthrottle(c->u.x11.xconn);
7499 /* agent sockets are request/response and need no
7500 * buffer management */
7503 pfd_unthrottle(c->u.pfd.pf);
7509 static int ssh_is_simple(Ssh ssh)
7512 * We use the 'simple' variant of the SSH protocol if we're asked
7513 * to, except not if we're also doing connection-sharing (either
7514 * tunnelling our packets over an upstream or expecting to be
7515 * tunnelled over ourselves), since then the assumption that we
7516 * have only one channel to worry about is not true after all.
7518 return (conf_get_int(ssh->conf, CONF_ssh_simple) &&
7519 !ssh->bare_connection && !ssh->connshare);
7523 * Set up most of a new ssh_channel for SSH-2.
7525 static void ssh2_channel_init(struct ssh_channel *c)
7528 c->localid = alloc_channel_id(ssh);
7530 c->pending_eof = FALSE;
7531 c->throttling_conn = FALSE;
7532 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
7533 ssh_is_simple(ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
7534 c->v.v2.chanreq_head = NULL;
7535 c->v.v2.throttle_state = UNTHROTTLED;
7536 bufchain_init(&c->v.v2.outbuffer);
7540 * Construct the common parts of a CHANNEL_OPEN.
7542 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c,
7545 struct Packet *pktout;
7547 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7548 ssh2_pkt_addstring(pktout, type);
7549 ssh2_pkt_adduint32(pktout, c->localid);
7550 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7551 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7556 * CHANNEL_FAILURE doesn't come with any indication of what message
7557 * caused it, so we have to keep track of the outstanding
7558 * CHANNEL_REQUESTs ourselves.
7560 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
7561 cchandler_fn_t handler, void *ctx)
7563 struct outstanding_channel_request *ocr =
7564 snew(struct outstanding_channel_request);
7566 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7567 ocr->handler = handler;
7570 if (!c->v.v2.chanreq_head)
7571 c->v.v2.chanreq_head = ocr;
7573 c->v.v2.chanreq_tail->next = ocr;
7574 c->v.v2.chanreq_tail = ocr;
7578 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
7579 * NULL then a reply will be requested and the handler will be called
7580 * when it arrives. The returned packet is ready to have any
7581 * request-specific data added and be sent. Note that if a handler is
7582 * provided, it's essential that the request actually be sent.
7584 * The handler will usually be passed the response packet in pktin. If
7585 * pktin is NULL, this means that no reply will ever be forthcoming
7586 * (e.g. because the entire connection is being destroyed, or because
7587 * the server initiated channel closure before we saw the response)
7588 * and the handler should free any storage it's holding.
7590 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c,
7592 cchandler_fn_t handler, void *ctx)
7594 struct Packet *pktout;
7596 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7597 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7598 ssh2_pkt_adduint32(pktout, c->remoteid);
7599 ssh2_pkt_addstring(pktout, type);
7600 ssh2_pkt_addbool(pktout, handler != NULL);
7601 if (handler != NULL)
7602 ssh2_queue_chanreq_handler(c, handler, ctx);
7607 * Potentially enlarge the window on an SSH-2 channel.
7609 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
7611 static void ssh2_set_window(struct ssh_channel *c, int newwin)
7616 * Never send WINDOW_ADJUST for a channel that the remote side has
7617 * already sent EOF on; there's no point, since it won't be
7618 * sending any more data anyway. Ditto if _we've_ already sent
7621 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
7625 * Also, never widen the window for an X11 channel when we're
7626 * still waiting to see its initial auth and may yet hand it off
7629 if (c->type == CHAN_X11 && c->u.x11.initial)
7633 * If the remote end has a habit of ignoring maxpkt, limit the
7634 * window so that it has no choice (assuming it doesn't ignore the
7637 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
7638 newwin = OUR_V2_MAXPKT;
7641 * Only send a WINDOW_ADJUST if there's significantly more window
7642 * available than the other end thinks there is. This saves us
7643 * sending a WINDOW_ADJUST for every character in a shell session.
7645 * "Significant" is arbitrarily defined as half the window size.
7647 if (newwin / 2 >= c->v.v2.locwindow) {
7648 struct Packet *pktout;
7652 * In order to keep track of how much window the client
7653 * actually has available, we'd like it to acknowledge each
7654 * WINDOW_ADJUST. We can't do that directly, so we accompany
7655 * it with a CHANNEL_REQUEST that has to be acknowledged.
7657 * This is only necessary if we're opening the window wide.
7658 * If we're not, then throughput is being constrained by
7659 * something other than the maximum window size anyway.
7661 if (newwin == c->v.v2.locmaxwin &&
7662 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
7663 up = snew(unsigned);
7664 *up = newwin - c->v.v2.locwindow;
7665 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
7666 ssh2_handle_winadj_response, up);
7667 ssh2_pkt_send(ssh, pktout);
7669 if (c->v.v2.throttle_state != UNTHROTTLED)
7670 c->v.v2.throttle_state = UNTHROTTLING;
7672 /* Pretend the WINDOW_ADJUST was acked immediately. */
7673 c->v.v2.remlocwin = newwin;
7674 c->v.v2.throttle_state = THROTTLED;
7676 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7677 ssh2_pkt_adduint32(pktout, c->remoteid);
7678 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
7679 ssh2_pkt_send(ssh, pktout);
7680 c->v.v2.locwindow = newwin;
7685 * Find the channel associated with a message. If there's no channel,
7686 * or it's not properly open, make a noise about it and return NULL.
7688 static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
7690 unsigned localid = ssh_pkt_getuint32(pktin);
7691 struct ssh_channel *c;
7693 c = find234(ssh->channels, &localid, ssh_channelfind);
7695 (c->type != CHAN_SHARING && c->halfopen &&
7696 pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
7697 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
7698 char *buf = dupprintf("Received %s for %s channel %u",
7699 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
7701 c ? "half-open" : "nonexistent", localid);
7702 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
7709 static void ssh2_handle_winadj_response(struct ssh_channel *c,
7710 struct Packet *pktin, void *ctx)
7712 unsigned *sizep = ctx;
7715 * Winadj responses should always be failures. However, at least
7716 * one server ("boks_sshd") is known to return SUCCESS for channel
7717 * requests it's never heard of, such as "winadj@putty". Raised
7718 * with foxt.com as bug 090916-090424, but for the sake of a quiet
7719 * life, we don't worry about what kind of response we got.
7722 c->v.v2.remlocwin += *sizep;
7725 * winadj messages are only sent when the window is fully open, so
7726 * if we get an ack of one, we know any pending unthrottle is
7729 if (c->v.v2.throttle_state == UNTHROTTLING)
7730 c->v.v2.throttle_state = UNTHROTTLED;
7733 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
7735 struct ssh_channel *c = ssh2_channel_msg(ssh, pktin);
7736 struct outstanding_channel_request *ocr;
7739 if (c->type == CHAN_SHARING) {
7740 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7741 pktin->body, pktin->length);
7744 ocr = c->v.v2.chanreq_head;
7746 ssh2_msg_unexpected(ssh, pktin);
7749 ocr->handler(c, pktin, ocr->ctx);
7750 c->v.v2.chanreq_head = ocr->next;
7753 * We may now initiate channel-closing procedures, if that
7754 * CHANNEL_REQUEST was the last thing outstanding before we send
7757 ssh2_channel_check_close(c);
7760 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
7762 struct ssh_channel *c;
7763 c = ssh2_channel_msg(ssh, pktin);
7766 if (c->type == CHAN_SHARING) {
7767 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7768 pktin->body, pktin->length);
7771 if (!(c->closes & CLOSES_SENT_EOF)) {
7772 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
7773 ssh2_try_send_and_unthrottle(ssh, c);
7777 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
7781 struct ssh_channel *c;
7782 c = ssh2_channel_msg(ssh, pktin);
7785 if (c->type == CHAN_SHARING) {
7786 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7787 pktin->body, pktin->length);
7790 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
7791 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
7792 return; /* extended but not stderr */
7793 ssh_pkt_getstring(pktin, &data, &length);
7796 c->v.v2.locwindow -= length;
7797 c->v.v2.remlocwin -= length;
7799 case CHAN_MAINSESSION:
7801 from_backend(ssh->frontend, pktin->type ==
7802 SSH2_MSG_CHANNEL_EXTENDED_DATA,
7806 bufsize = x11_send(c->u.x11.xconn, data, length);
7809 bufsize = pfd_send(c->u.pfd.pf, data, length);
7812 while (length > 0) {
7813 if (c->u.a.lensofar < 4) {
7814 unsigned int l = min(4 - c->u.a.lensofar,
7816 memcpy(c->u.a.msglen + c->u.a.lensofar,
7820 c->u.a.lensofar += l;
7822 if (c->u.a.lensofar == 4) {
7824 4 + GET_32BIT(c->u.a.msglen);
7825 c->u.a.message = snewn(c->u.a.totallen,
7827 memcpy(c->u.a.message, c->u.a.msglen, 4);
7829 if (c->u.a.lensofar >= 4 && length > 0) {
7831 min(c->u.a.totallen - c->u.a.lensofar,
7833 memcpy(c->u.a.message + c->u.a.lensofar,
7837 c->u.a.lensofar += l;
7839 if (c->u.a.lensofar == c->u.a.totallen) {
7842 c->u.a.outstanding_requests++;
7843 if (agent_query(c->u.a.message,
7846 ssh_agentf_callback, c))
7847 ssh_agentf_callback(c, reply, replylen);
7848 sfree(c->u.a.message);
7849 c->u.a.message = NULL;
7850 c->u.a.lensofar = 0;
7857 * If it looks like the remote end hit the end of its window,
7858 * and we didn't want it to do that, think about using a
7861 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
7862 c->v.v2.locmaxwin < 0x40000000)
7863 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
7865 * If we are not buffering too much data,
7866 * enlarge the window again at the remote side.
7867 * If we are buffering too much, we may still
7868 * need to adjust the window if the server's
7871 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
7872 c->v.v2.locmaxwin - bufsize : 0);
7874 * If we're either buffering way too much data, or if we're
7875 * buffering anything at all and we're in "simple" mode,
7876 * throttle the whole channel.
7878 if ((bufsize > c->v.v2.locmaxwin || (ssh_is_simple(ssh) && bufsize>0))
7879 && !c->throttling_conn) {
7880 c->throttling_conn = 1;
7881 ssh_throttle_conn(ssh, +1);
7886 static void ssh_check_termination(Ssh ssh)
7888 if (ssh->version == 2 &&
7889 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
7890 (ssh->channels && count234(ssh->channels) == 0) &&
7891 !(ssh->connshare && share_ndownstreams(ssh->connshare) > 0)) {
7893 * We used to send SSH_MSG_DISCONNECT here, because I'd
7894 * believed that _every_ conforming SSH-2 connection had to
7895 * end with a disconnect being sent by at least one side;
7896 * apparently I was wrong and it's perfectly OK to
7897 * unceremoniously slam the connection shut when you're done,
7898 * and indeed OpenSSH feels this is more polite than sending a
7899 * DISCONNECT. So now we don't.
7901 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
7905 void ssh_sharing_downstream_connected(Ssh ssh, unsigned id,
7906 const char *peerinfo)
7909 logeventf(ssh, "Connection sharing downstream #%u connected from %s",
7912 logeventf(ssh, "Connection sharing downstream #%u connected", id);
7915 void ssh_sharing_downstream_disconnected(Ssh ssh, unsigned id)
7917 logeventf(ssh, "Connection sharing downstream #%u disconnected", id);
7918 ssh_check_termination(ssh);
7921 void ssh_sharing_logf(Ssh ssh, unsigned id, const char *logfmt, ...)
7926 va_start(ap, logfmt);
7927 buf = dupvprintf(logfmt, ap);
7930 logeventf(ssh, "Connection sharing downstream #%u: %s", id, buf);
7932 logeventf(ssh, "Connection sharing: %s", buf);
7936 static void ssh_channel_destroy(struct ssh_channel *c)
7941 case CHAN_MAINSESSION:
7942 ssh->mainchan = NULL;
7943 update_specials_menu(ssh->frontend);
7946 if (c->u.x11.xconn != NULL)
7947 x11_close(c->u.x11.xconn);
7948 logevent("Forwarded X11 connection terminated");
7951 sfree(c->u.a.message);
7954 if (c->u.pfd.pf != NULL)
7955 pfd_close(c->u.pfd.pf);
7956 logevent("Forwarded port closed");
7960 del234(ssh->channels, c);
7961 if (ssh->version == 2) {
7962 bufchain_clear(&c->v.v2.outbuffer);
7963 assert(c->v.v2.chanreq_head == NULL);
7968 * If that was the last channel left open, we might need to
7971 ssh_check_termination(ssh);
7974 static void ssh2_channel_check_close(struct ssh_channel *c)
7977 struct Packet *pktout;
7981 * If we've sent out our own CHANNEL_OPEN but not yet seen
7982 * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
7983 * it's too early to be sending close messages of any kind.
7988 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
7989 c->type == CHAN_ZOMBIE) &&
7990 !c->v.v2.chanreq_head &&
7991 !(c->closes & CLOSES_SENT_CLOSE)) {
7993 * We have both sent and received EOF (or the channel is a
7994 * zombie), and we have no outstanding channel requests, which
7995 * means the channel is in final wind-up. But we haven't sent
7996 * CLOSE, so let's do so now.
7998 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
7999 ssh2_pkt_adduint32(pktout, c->remoteid);
8000 ssh2_pkt_send(ssh, pktout);
8001 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
8004 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
8005 assert(c->v.v2.chanreq_head == NULL);
8007 * We have both sent and received CLOSE, which means we're
8008 * completely done with the channel.
8010 ssh_channel_destroy(c);
8014 static void ssh2_channel_got_eof(struct ssh_channel *c)
8016 if (c->closes & CLOSES_RCVD_EOF)
8017 return; /* already seen EOF */
8018 c->closes |= CLOSES_RCVD_EOF;
8020 if (c->type == CHAN_X11) {
8021 x11_send_eof(c->u.x11.xconn);
8022 } else if (c->type == CHAN_AGENT) {
8023 if (c->u.a.outstanding_requests == 0) {
8024 /* Manufacture an outgoing EOF in response to the incoming one. */
8025 sshfwd_write_eof(c);
8027 } else if (c->type == CHAN_SOCKDATA) {
8028 pfd_send_eof(c->u.pfd.pf);
8029 } else if (c->type == CHAN_MAINSESSION) {
8032 if (!ssh->sent_console_eof &&
8033 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
8035 * Either from_backend_eof told us that the front end
8036 * wants us to close the outgoing side of the connection
8037 * as soon as we see EOF from the far end, or else we've
8038 * unilaterally decided to do that because we've allocated
8039 * a remote pty and hence EOF isn't a particularly
8040 * meaningful concept.
8042 sshfwd_write_eof(c);
8044 ssh->sent_console_eof = TRUE;
8047 ssh2_channel_check_close(c);
8050 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
8052 struct ssh_channel *c;
8054 c = ssh2_channel_msg(ssh, pktin);
8057 if (c->type == CHAN_SHARING) {
8058 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8059 pktin->body, pktin->length);
8062 ssh2_channel_got_eof(c);
8065 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
8067 struct ssh_channel *c;
8069 c = ssh2_channel_msg(ssh, pktin);
8072 if (c->type == CHAN_SHARING) {
8073 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8074 pktin->body, pktin->length);
8079 * When we receive CLOSE on a channel, we assume it comes with an
8080 * implied EOF if we haven't seen EOF yet.
8082 ssh2_channel_got_eof(c);
8084 if (!(ssh->remote_bugs & BUG_SENDS_LATE_REQUEST_REPLY)) {
8086 * It also means we stop expecting to see replies to any
8087 * outstanding channel requests, so clean those up too.
8088 * (ssh_chanreq_init will enforce by assertion that we don't
8089 * subsequently put anything back on this list.)
8091 while (c->v.v2.chanreq_head) {
8092 struct outstanding_channel_request *ocr = c->v.v2.chanreq_head;
8093 ocr->handler(c, NULL, ocr->ctx);
8094 c->v.v2.chanreq_head = ocr->next;
8100 * And we also send an outgoing EOF, if we haven't already, on the
8101 * assumption that CLOSE is a pretty forceful announcement that
8102 * the remote side is doing away with the entire channel. (If it
8103 * had wanted to send us EOF and continue receiving data from us,
8104 * it would have just sent CHANNEL_EOF.)
8106 if (!(c->closes & CLOSES_SENT_EOF)) {
8108 * Make sure we don't read any more from whatever our local
8109 * data source is for this channel.
8112 case CHAN_MAINSESSION:
8113 ssh->send_ok = 0; /* stop trying to read from stdin */
8116 x11_override_throttle(c->u.x11.xconn, 1);
8119 pfd_override_throttle(c->u.pfd.pf, 1);
8124 * Abandon any buffered data we still wanted to send to this
8125 * channel. Receiving a CHANNEL_CLOSE is an indication that
8126 * the server really wants to get on and _destroy_ this
8127 * channel, and it isn't going to send us any further
8128 * WINDOW_ADJUSTs to permit us to send pending stuff.
8130 bufchain_clear(&c->v.v2.outbuffer);
8133 * Send outgoing EOF.
8135 sshfwd_write_eof(c);
8139 * Now process the actual close.
8141 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
8142 c->closes |= CLOSES_RCVD_CLOSE;
8143 ssh2_channel_check_close(c);
8147 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
8149 struct ssh_channel *c;
8151 c = ssh2_channel_msg(ssh, pktin);
8154 if (c->type == CHAN_SHARING) {
8155 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8156 pktin->body, pktin->length);
8159 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
8160 c->remoteid = ssh_pkt_getuint32(pktin);
8161 c->halfopen = FALSE;
8162 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8163 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
8165 if (c->type == CHAN_SOCKDATA_DORMANT) {
8166 c->type = CHAN_SOCKDATA;
8168 pfd_confirm(c->u.pfd.pf);
8169 } else if (c->type == CHAN_ZOMBIE) {
8171 * This case can occur if a local socket error occurred
8172 * between us sending out CHANNEL_OPEN and receiving
8173 * OPEN_CONFIRMATION. In this case, all we can do is
8174 * immediately initiate close proceedings now that we know the
8175 * server's id to put in the close message.
8177 ssh2_channel_check_close(c);
8180 * We never expect to receive OPEN_CONFIRMATION for any
8181 * *other* channel type (since only local-to-remote port
8182 * forwardings cause us to send CHANNEL_OPEN after the main
8183 * channel is live - all other auxiliary channel types are
8184 * initiated from the server end). It's safe to enforce this
8185 * by assertion rather than by ssh_disconnect, because the
8186 * real point is that we never constructed a half-open channel
8187 * structure in the first place with any type other than the
8190 assert(!"Funny channel type in ssh2_msg_channel_open_confirmation");
8194 ssh_channel_try_eof(c); /* in case we had a pending EOF */
8197 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
8199 static const char *const reasons[] = {
8200 "<unknown reason code>",
8201 "Administratively prohibited",
8203 "Unknown channel type",
8204 "Resource shortage",
8206 unsigned reason_code;
8207 char *reason_string;
8209 struct ssh_channel *c;
8211 c = ssh2_channel_msg(ssh, pktin);
8214 if (c->type == CHAN_SHARING) {
8215 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8216 pktin->body, pktin->length);
8219 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
8221 if (c->type == CHAN_SOCKDATA_DORMANT) {
8222 reason_code = ssh_pkt_getuint32(pktin);
8223 if (reason_code >= lenof(reasons))
8224 reason_code = 0; /* ensure reasons[reason_code] in range */
8225 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
8226 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
8227 reasons[reason_code], reason_length, reason_string);
8229 pfd_close(c->u.pfd.pf);
8230 } else if (c->type == CHAN_ZOMBIE) {
8232 * This case can occur if a local socket error occurred
8233 * between us sending out CHANNEL_OPEN and receiving
8234 * OPEN_FAILURE. In this case, we need do nothing except allow
8235 * the code below to throw the half-open channel away.
8239 * We never expect to receive OPEN_FAILURE for any *other*
8240 * channel type (since only local-to-remote port forwardings
8241 * cause us to send CHANNEL_OPEN after the main channel is
8242 * live - all other auxiliary channel types are initiated from
8243 * the server end). It's safe to enforce this by assertion
8244 * rather than by ssh_disconnect, because the real point is
8245 * that we never constructed a half-open channel structure in
8246 * the first place with any type other than the above.
8248 assert(!"Funny channel type in ssh2_msg_channel_open_failure");
8251 del234(ssh->channels, c);
8255 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
8258 int typelen, want_reply;
8259 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
8260 struct ssh_channel *c;
8261 struct Packet *pktout;
8263 c = ssh2_channel_msg(ssh, pktin);
8266 if (c->type == CHAN_SHARING) {
8267 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8268 pktin->body, pktin->length);
8271 ssh_pkt_getstring(pktin, &type, &typelen);
8272 want_reply = ssh2_pkt_getbool(pktin);
8274 if (c->closes & CLOSES_SENT_CLOSE) {
8276 * We don't reply to channel requests after we've sent
8277 * CHANNEL_CLOSE for the channel, because our reply might
8278 * cross in the network with the other side's CHANNEL_CLOSE
8279 * and arrive after they have wound the channel up completely.
8285 * Having got the channel number, we now look at
8286 * the request type string to see if it's something
8289 if (c == ssh->mainchan) {
8291 * We recognise "exit-status" and "exit-signal" on
8292 * the primary channel.
8294 if (typelen == 11 &&
8295 !memcmp(type, "exit-status", 11)) {
8297 ssh->exitcode = ssh_pkt_getuint32(pktin);
8298 logeventf(ssh, "Server sent command exit status %d",
8300 reply = SSH2_MSG_CHANNEL_SUCCESS;
8302 } else if (typelen == 11 &&
8303 !memcmp(type, "exit-signal", 11)) {
8305 int is_plausible = TRUE, is_int = FALSE;
8306 char *fmt_sig = NULL, *fmt_msg = NULL;
8308 int msglen = 0, core = FALSE;
8309 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
8310 * provide an `int' for the signal, despite its
8311 * having been a `string' in the drafts of RFC 4254 since at
8312 * least 2001. (Fixed in session.c 1.147.) Try to
8313 * infer which we can safely parse it as. */
8315 unsigned char *p = pktin->body +
8317 long len = pktin->length - pktin->savedpos;
8318 unsigned long num = GET_32BIT(p); /* what is it? */
8319 /* If it's 0, it hardly matters; assume string */
8323 int maybe_int = FALSE, maybe_str = FALSE;
8324 #define CHECK_HYPOTHESIS(offset, result) \
8327 int q = toint(offset); \
8328 if (q >= 0 && q+4 <= len) { \
8329 q = toint(q + 4 + GET_32BIT(p+q)); \
8330 if (q >= 0 && q+4 <= len && \
8331 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
8336 CHECK_HYPOTHESIS(4+1, maybe_int);
8337 CHECK_HYPOTHESIS(4+num+1, maybe_str);
8338 #undef CHECK_HYPOTHESIS
8339 if (maybe_int && !maybe_str)
8341 else if (!maybe_int && maybe_str)
8344 /* Crikey. Either or neither. Panic. */
8345 is_plausible = FALSE;
8348 ssh->exitcode = 128; /* means `unknown signal' */
8351 /* Old non-standard OpenSSH. */
8352 int signum = ssh_pkt_getuint32(pktin);
8353 fmt_sig = dupprintf(" %d", signum);
8354 ssh->exitcode = 128 + signum;
8356 /* As per RFC 4254. */
8359 ssh_pkt_getstring(pktin, &sig, &siglen);
8360 /* Signal name isn't supposed to be blank, but
8361 * let's cope gracefully if it is. */
8363 fmt_sig = dupprintf(" \"%.*s\"",
8368 * Really hideous method of translating the
8369 * signal description back into a locally
8370 * meaningful number.
8375 #define TRANSLATE_SIGNAL(s) \
8376 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
8377 ssh->exitcode = 128 + SIG ## s
8379 TRANSLATE_SIGNAL(ABRT);
8382 TRANSLATE_SIGNAL(ALRM);
8385 TRANSLATE_SIGNAL(FPE);
8388 TRANSLATE_SIGNAL(HUP);
8391 TRANSLATE_SIGNAL(ILL);
8394 TRANSLATE_SIGNAL(INT);
8397 TRANSLATE_SIGNAL(KILL);
8400 TRANSLATE_SIGNAL(PIPE);
8403 TRANSLATE_SIGNAL(QUIT);
8406 TRANSLATE_SIGNAL(SEGV);
8409 TRANSLATE_SIGNAL(TERM);
8412 TRANSLATE_SIGNAL(USR1);
8415 TRANSLATE_SIGNAL(USR2);
8417 #undef TRANSLATE_SIGNAL
8419 ssh->exitcode = 128;
8421 core = ssh2_pkt_getbool(pktin);
8422 ssh_pkt_getstring(pktin, &msg, &msglen);
8424 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
8426 /* ignore lang tag */
8427 } /* else don't attempt to parse */
8428 logeventf(ssh, "Server exited on signal%s%s%s",
8429 fmt_sig ? fmt_sig : "",
8430 core ? " (core dumped)" : "",
8431 fmt_msg ? fmt_msg : "");
8434 reply = SSH2_MSG_CHANNEL_SUCCESS;
8439 * This is a channel request we don't know
8440 * about, so we now either ignore the request
8441 * or respond with CHANNEL_FAILURE, depending
8444 reply = SSH2_MSG_CHANNEL_FAILURE;
8447 pktout = ssh2_pkt_init(reply);
8448 ssh2_pkt_adduint32(pktout, c->remoteid);
8449 ssh2_pkt_send(ssh, pktout);
8453 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
8456 int typelen, want_reply;
8457 struct Packet *pktout;
8459 ssh_pkt_getstring(pktin, &type, &typelen);
8460 want_reply = ssh2_pkt_getbool(pktin);
8463 * We currently don't support any global requests
8464 * at all, so we either ignore the request or
8465 * respond with REQUEST_FAILURE, depending on
8469 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
8470 ssh2_pkt_send(ssh, pktout);
8474 struct X11FakeAuth *ssh_sharing_add_x11_display(Ssh ssh, int authtype,
8478 struct X11FakeAuth *auth;
8481 * Make up a new set of fake X11 auth data, and add it to the tree
8482 * of currently valid ones with an indication of the sharing
8483 * context that it's relevant to.
8485 auth = x11_invent_fake_auth(ssh->x11authtree, authtype);
8486 auth->share_cs = share_cs;
8487 auth->share_chan = share_chan;
8492 void ssh_sharing_remove_x11_display(Ssh ssh, struct X11FakeAuth *auth)
8494 del234(ssh->x11authtree, auth);
8495 x11_free_fake_auth(auth);
8498 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
8505 const char *error = NULL;
8506 struct ssh_channel *c;
8507 unsigned remid, winsize, pktsize;
8508 unsigned our_winsize_override = 0;
8509 struct Packet *pktout;
8511 ssh_pkt_getstring(pktin, &type, &typelen);
8512 c = snew(struct ssh_channel);
8515 remid = ssh_pkt_getuint32(pktin);
8516 winsize = ssh_pkt_getuint32(pktin);
8517 pktsize = ssh_pkt_getuint32(pktin);
8519 if (typelen == 3 && !memcmp(type, "x11", 3)) {
8522 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8523 addrstr = snewn(peeraddrlen+1, char);
8524 memcpy(addrstr, peeraddr, peeraddrlen);
8525 addrstr[peeraddrlen] = '\0';
8526 peerport = ssh_pkt_getuint32(pktin);
8528 logeventf(ssh, "Received X11 connect request from %s:%d",
8531 if (!ssh->X11_fwd_enabled && !ssh->connshare)
8532 error = "X11 forwarding is not enabled";
8534 c->u.x11.xconn = x11_init(ssh->x11authtree, c,
8537 c->u.x11.initial = TRUE;
8540 * If we are a connection-sharing upstream, then we should
8541 * initially present a very small window, adequate to take
8542 * the X11 initial authorisation packet but not much more.
8543 * Downstream will then present us a larger window (by
8544 * fiat of the connection-sharing protocol) and we can
8545 * guarantee to send a positive-valued WINDOW_ADJUST.
8548 our_winsize_override = 128;
8550 logevent("Opened X11 forward channel");
8554 } else if (typelen == 15 &&
8555 !memcmp(type, "forwarded-tcpip", 15)) {
8556 struct ssh_rportfwd pf, *realpf;
8559 ssh_pkt_getstring(pktin, &shost, &shostlen);/* skip address */
8560 pf.shost = dupprintf("%.*s", shostlen, shost);
8561 pf.sport = ssh_pkt_getuint32(pktin);
8562 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8563 peerport = ssh_pkt_getuint32(pktin);
8564 realpf = find234(ssh->rportfwds, &pf, NULL);
8565 logeventf(ssh, "Received remote port %s:%d open request "
8566 "from %s:%d", pf.shost, pf.sport, peeraddr, peerport);
8569 if (realpf == NULL) {
8570 error = "Remote port is not recognised";
8574 if (realpf->share_ctx) {
8576 * This port forwarding is on behalf of a
8577 * connection-sharing downstream, so abandon our own
8578 * channel-open procedure and just pass the message on
8581 share_got_pkt_from_server(realpf->share_ctx, pktin->type,
8582 pktin->body, pktin->length);
8587 err = pfd_connect(&c->u.pfd.pf, realpf->dhost, realpf->dport,
8588 c, ssh->conf, realpf->pfrec->addressfamily);
8589 logeventf(ssh, "Attempting to forward remote port to "
8590 "%s:%d", realpf->dhost, realpf->dport);
8592 logeventf(ssh, "Port open failed: %s", err);
8594 error = "Port open failed";
8596 logevent("Forwarded port opened successfully");
8597 c->type = CHAN_SOCKDATA;
8600 } else if (typelen == 22 &&
8601 !memcmp(type, "auth-agent@openssh.com", 22)) {
8602 if (!ssh->agentfwd_enabled)
8603 error = "Agent forwarding is not enabled";
8605 c->type = CHAN_AGENT; /* identify channel type */
8606 c->u.a.lensofar = 0;
8607 c->u.a.message = NULL;
8608 c->u.a.outstanding_requests = 0;
8611 error = "Unsupported channel type requested";
8614 c->remoteid = remid;
8615 c->halfopen = FALSE;
8617 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
8618 ssh2_pkt_adduint32(pktout, c->remoteid);
8619 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
8620 ssh2_pkt_addstring(pktout, error);
8621 ssh2_pkt_addstring(pktout, "en"); /* language tag */
8622 ssh2_pkt_send(ssh, pktout);
8623 logeventf(ssh, "Rejected channel open: %s", error);
8626 ssh2_channel_init(c);
8627 c->v.v2.remwindow = winsize;
8628 c->v.v2.remmaxpkt = pktsize;
8629 if (our_winsize_override) {
8630 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
8631 our_winsize_override;
8633 add234(ssh->channels, c);
8634 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
8635 ssh2_pkt_adduint32(pktout, c->remoteid);
8636 ssh2_pkt_adduint32(pktout, c->localid);
8637 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
8638 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8639 ssh2_pkt_send(ssh, pktout);
8643 void sshfwd_x11_sharing_handover(struct ssh_channel *c,
8644 void *share_cs, void *share_chan,
8645 const char *peer_addr, int peer_port,
8646 int endian, int protomajor, int protominor,
8647 const void *initial_data, int initial_len)
8650 * This function is called when we've just discovered that an X
8651 * forwarding channel on which we'd been handling the initial auth
8652 * ourselves turns out to be destined for a connection-sharing
8653 * downstream. So we turn the channel into a CHAN_SHARING, meaning
8654 * that we completely stop tracking windows and buffering data and
8655 * just pass more or less unmodified SSH messages back and forth.
8657 c->type = CHAN_SHARING;
8658 c->u.sharing.ctx = share_cs;
8659 share_setup_x11_channel(share_cs, share_chan,
8660 c->localid, c->remoteid, c->v.v2.remwindow,
8661 c->v.v2.remmaxpkt, c->v.v2.locwindow,
8662 peer_addr, peer_port, endian,
8663 protomajor, protominor,
8664 initial_data, initial_len);
8667 void sshfwd_x11_is_local(struct ssh_channel *c)
8670 * This function is called when we've just discovered that an X
8671 * forwarding channel is _not_ destined for a connection-sharing
8672 * downstream but we're going to handle it ourselves. We stop
8673 * presenting a cautiously small window and go into ordinary data
8676 c->u.x11.initial = FALSE;
8677 ssh2_set_window(c, ssh_is_simple(c->ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE);
8681 * Buffer banner messages for later display at some convenient point,
8682 * if we're going to display them.
8684 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
8686 /* Arbitrary limit to prevent unbounded inflation of buffer */
8687 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
8688 bufchain_size(&ssh->banner) <= 131072) {
8689 char *banner = NULL;
8691 ssh_pkt_getstring(pktin, &banner, &size);
8693 bufchain_add(&ssh->banner, banner, size);
8697 /* Helper function to deal with sending tty modes for "pty-req" */
8698 static void ssh2_send_ttymode(void *data, char *mode, char *val)
8700 struct Packet *pktout = (struct Packet *)data;
8702 unsigned int arg = 0;
8703 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
8704 if (i == lenof(ssh_ttymodes)) return;
8705 switch (ssh_ttymodes[i].type) {
8707 arg = ssh_tty_parse_specchar(val);
8710 arg = ssh_tty_parse_boolean(val);
8713 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
8714 ssh2_pkt_adduint32(pktout, arg);
8717 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
8720 struct ssh2_setup_x11_state {
8724 struct Packet *pktout;
8725 crStateP(ssh2_setup_x11_state, ctx);
8729 logevent("Requesting X11 forwarding");
8730 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
8732 ssh2_pkt_addbool(pktout, 0); /* many connections */
8733 ssh2_pkt_addstring(pktout, ssh->x11auth->protoname);
8734 ssh2_pkt_addstring(pktout, ssh->x11auth->datastring);
8735 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
8736 ssh2_pkt_send(ssh, pktout);
8738 /* Wait to be called back with either a response packet, or NULL
8739 * meaning clean up and free our data */
8743 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8744 logevent("X11 forwarding enabled");
8745 ssh->X11_fwd_enabled = TRUE;
8747 logevent("X11 forwarding refused");
8753 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
8756 struct ssh2_setup_agent_state {
8760 struct Packet *pktout;
8761 crStateP(ssh2_setup_agent_state, ctx);
8765 logevent("Requesting OpenSSH-style agent forwarding");
8766 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
8767 ssh2_setup_agent, s);
8768 ssh2_pkt_send(ssh, pktout);
8770 /* Wait to be called back with either a response packet, or NULL
8771 * meaning clean up and free our data */
8775 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8776 logevent("Agent forwarding enabled");
8777 ssh->agentfwd_enabled = TRUE;
8779 logevent("Agent forwarding refused");
8785 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
8788 struct ssh2_setup_pty_state {
8792 struct Packet *pktout;
8793 crStateP(ssh2_setup_pty_state, ctx);
8797 /* Unpick the terminal-speed string. */
8798 /* XXX perhaps we should allow no speeds to be sent. */
8799 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
8800 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
8801 /* Build the pty request. */
8802 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
8804 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
8805 ssh2_pkt_adduint32(pktout, ssh->term_width);
8806 ssh2_pkt_adduint32(pktout, ssh->term_height);
8807 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
8808 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
8809 ssh2_pkt_addstring_start(pktout);
8810 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
8811 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
8812 ssh2_pkt_adduint32(pktout, ssh->ispeed);
8813 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
8814 ssh2_pkt_adduint32(pktout, ssh->ospeed);
8815 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
8816 ssh2_pkt_send(ssh, pktout);
8817 ssh->state = SSH_STATE_INTERMED;
8819 /* Wait to be called back with either a response packet, or NULL
8820 * meaning clean up and free our data */
8824 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8825 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
8826 ssh->ospeed, ssh->ispeed);
8827 ssh->got_pty = TRUE;
8829 c_write_str(ssh, "Server refused to allocate pty\r\n");
8830 ssh->editing = ssh->echoing = 1;
8837 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
8840 struct ssh2_setup_env_state {
8842 int num_env, env_left, env_ok;
8845 struct Packet *pktout;
8846 crStateP(ssh2_setup_env_state, ctx);
8851 * Send environment variables.
8853 * Simplest thing here is to send all the requests at once, and
8854 * then wait for a whole bunch of successes or failures.
8860 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
8862 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
8863 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
8864 ssh2_pkt_addstring(pktout, key);
8865 ssh2_pkt_addstring(pktout, val);
8866 ssh2_pkt_send(ssh, pktout);
8871 logeventf(ssh, "Sent %d environment variables", s->num_env);
8876 s->env_left = s->num_env;
8878 while (s->env_left > 0) {
8879 /* Wait to be called back with either a response packet,
8880 * or NULL meaning clean up and free our data */
8882 if (!pktin) goto out;
8883 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
8888 if (s->env_ok == s->num_env) {
8889 logevent("All environment variables successfully set");
8890 } else if (s->env_ok == 0) {
8891 logevent("All environment variables refused");
8892 c_write_str(ssh, "Server refused to set environment variables\r\n");
8894 logeventf(ssh, "%d environment variables refused",
8895 s->num_env - s->env_ok);
8896 c_write_str(ssh, "Server refused to set all environment variables\r\n");
8904 * Handle the SSH-2 userauth and connection layers.
8906 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
8908 do_ssh2_authconn(ssh, NULL, 0, pktin);
8911 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
8915 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
8918 static void do_ssh2_authconn(Ssh ssh, const unsigned char *in, int inlen,
8919 struct Packet *pktin)
8921 struct do_ssh2_authconn_state {
8925 AUTH_TYPE_PUBLICKEY,
8926 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
8927 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
8929 AUTH_TYPE_GSSAPI, /* always QUIET */
8930 AUTH_TYPE_KEYBOARD_INTERACTIVE,
8931 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
8933 int done_service_req;
8934 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
8935 int tried_pubkey_config, done_agent;
8940 int kbd_inter_refused;
8941 int we_are_in, userauth_success;
8942 prompts_t *cur_prompt;
8947 void *publickey_blob;
8948 int publickey_bloblen;
8949 int privatekey_available, privatekey_encrypted;
8950 char *publickey_algorithm;
8951 char *publickey_comment;
8952 unsigned char agent_request[5], *agent_response, *agentp;
8953 int agent_responselen;
8954 unsigned char *pkblob_in_agent;
8956 char *pkblob, *alg, *commentp;
8957 int pklen, alglen, commentlen;
8958 int siglen, retlen, len;
8959 char *q, *agentreq, *ret;
8961 struct Packet *pktout;
8964 struct ssh_gss_library *gsslib;
8965 Ssh_gss_ctx gss_ctx;
8966 Ssh_gss_buf gss_buf;
8967 Ssh_gss_buf gss_rcvtok, gss_sndtok;
8968 Ssh_gss_name gss_srv_name;
8969 Ssh_gss_stat gss_stat;
8972 crState(do_ssh2_authconn_state);
8976 /* Register as a handler for all the messages this coroutine handles. */
8977 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
8978 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
8979 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
8980 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
8981 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
8982 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
8983 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
8984 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
8985 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
8986 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
8987 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
8988 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
8989 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
8990 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
8991 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
8992 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
8993 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
8994 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
8995 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
8996 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
8998 s->done_service_req = FALSE;
8999 s->we_are_in = s->userauth_success = FALSE;
9000 s->agent_response = NULL;
9002 s->tried_gssapi = FALSE;
9005 if (!ssh->bare_connection) {
9006 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
9008 * Request userauth protocol, and await a response to it.
9010 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
9011 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
9012 ssh2_pkt_send(ssh, s->pktout);
9013 crWaitUntilV(pktin);
9014 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
9015 s->done_service_req = TRUE;
9017 if (!s->done_service_req) {
9019 * Request connection protocol directly, without authentication.
9021 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
9022 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9023 ssh2_pkt_send(ssh, s->pktout);
9024 crWaitUntilV(pktin);
9025 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
9026 s->we_are_in = TRUE; /* no auth required */
9028 bombout(("Server refused service request"));
9033 s->we_are_in = TRUE;
9036 /* Arrange to be able to deal with any BANNERs that come in.
9037 * (We do this now as packets may come in during the next bit.) */
9038 bufchain_init(&ssh->banner);
9039 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
9040 ssh2_msg_userauth_banner;
9043 * Misc one-time setup for authentication.
9045 s->publickey_blob = NULL;
9046 if (!s->we_are_in) {
9049 * Load the public half of any configured public key file
9052 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9053 if (!filename_is_null(s->keyfile)) {
9055 logeventf(ssh, "Reading key file \"%.150s\"",
9056 filename_to_str(s->keyfile));
9057 keytype = key_type(s->keyfile);
9058 if (keytype == SSH_KEYTYPE_SSH2 ||
9059 keytype == SSH_KEYTYPE_SSH2_PUBLIC_RFC4716 ||
9060 keytype == SSH_KEYTYPE_SSH2_PUBLIC_OPENSSH) {
9063 ssh2_userkey_loadpub(s->keyfile,
9064 &s->publickey_algorithm,
9065 &s->publickey_bloblen,
9066 &s->publickey_comment, &error);
9067 if (s->publickey_blob) {
9068 s->privatekey_available = (keytype == SSH_KEYTYPE_SSH2);
9069 if (!s->privatekey_available)
9070 logeventf(ssh, "Key file contains public key only");
9071 s->privatekey_encrypted =
9072 ssh2_userkey_encrypted(s->keyfile, NULL);
9075 logeventf(ssh, "Unable to load key (%s)",
9077 msgbuf = dupprintf("Unable to load key file "
9078 "\"%.150s\" (%s)\r\n",
9079 filename_to_str(s->keyfile),
9081 c_write_str(ssh, msgbuf);
9086 logeventf(ssh, "Unable to use this key file (%s)",
9087 key_type_to_str(keytype));
9088 msgbuf = dupprintf("Unable to use key file \"%.150s\""
9090 filename_to_str(s->keyfile),
9091 key_type_to_str(keytype));
9092 c_write_str(ssh, msgbuf);
9094 s->publickey_blob = NULL;
9099 * Find out about any keys Pageant has (but if there's a
9100 * public key configured, filter out all others).
9103 s->agent_response = NULL;
9104 s->pkblob_in_agent = NULL;
9105 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
9109 logevent("Pageant is running. Requesting keys.");
9111 /* Request the keys held by the agent. */
9112 PUT_32BIT(s->agent_request, 1);
9113 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
9114 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
9115 ssh_agent_callback, ssh)) {
9119 bombout(("Unexpected data from server while"
9120 " waiting for agent response"));
9123 } while (pktin || inlen > 0);
9124 r = ssh->agent_response;
9125 s->agent_responselen = ssh->agent_response_len;
9127 s->agent_response = (unsigned char *) r;
9128 if (s->agent_response && s->agent_responselen >= 5 &&
9129 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
9132 p = s->agent_response + 5;
9133 s->nkeys = toint(GET_32BIT(p));
9136 * Vet the Pageant response to ensure that the key
9137 * count and blob lengths make sense.
9140 logeventf(ssh, "Pageant response contained a negative"
9141 " key count %d", s->nkeys);
9143 goto done_agent_query;
9145 unsigned char *q = p + 4;
9146 int lenleft = s->agent_responselen - 5 - 4;
9148 for (keyi = 0; keyi < s->nkeys; keyi++) {
9149 int bloblen, commentlen;
9151 logeventf(ssh, "Pageant response was truncated");
9153 goto done_agent_query;
9155 bloblen = toint(GET_32BIT(q));
9156 if (bloblen < 0 || bloblen > lenleft) {
9157 logeventf(ssh, "Pageant response was truncated");
9159 goto done_agent_query;
9161 lenleft -= 4 + bloblen;
9163 commentlen = toint(GET_32BIT(q));
9164 if (commentlen < 0 || commentlen > lenleft) {
9165 logeventf(ssh, "Pageant response was truncated");
9167 goto done_agent_query;
9169 lenleft -= 4 + commentlen;
9170 q += 4 + commentlen;
9175 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
9176 if (s->publickey_blob) {
9177 /* See if configured key is in agent. */
9178 for (keyi = 0; keyi < s->nkeys; keyi++) {
9179 s->pklen = toint(GET_32BIT(p));
9180 if (s->pklen == s->publickey_bloblen &&
9181 !memcmp(p+4, s->publickey_blob,
9182 s->publickey_bloblen)) {
9183 logeventf(ssh, "Pageant key #%d matches "
9184 "configured key file", keyi);
9186 s->pkblob_in_agent = p;
9190 p += toint(GET_32BIT(p)) + 4; /* comment */
9192 if (!s->pkblob_in_agent) {
9193 logevent("Configured key file not in Pageant");
9198 logevent("Failed to get reply from Pageant");
9206 * We repeat this whole loop, including the username prompt,
9207 * until we manage a successful authentication. If the user
9208 * types the wrong _password_, they can be sent back to the
9209 * beginning to try another username, if this is configured on.
9210 * (If they specify a username in the config, they are never
9211 * asked, even if they do give a wrong password.)
9213 * I think this best serves the needs of
9215 * - the people who have no configuration, no keys, and just
9216 * want to try repeated (username,password) pairs until they
9217 * type both correctly
9219 * - people who have keys and configuration but occasionally
9220 * need to fall back to passwords
9222 * - people with a key held in Pageant, who might not have
9223 * logged in to a particular machine before; so they want to
9224 * type a username, and then _either_ their key will be
9225 * accepted, _or_ they will type a password. If they mistype
9226 * the username they will want to be able to get back and
9229 s->got_username = FALSE;
9230 while (!s->we_are_in) {
9234 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
9236 * We got a username last time round this loop, and
9237 * with change_username turned off we don't try to get
9240 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
9241 int ret; /* need not be kept over crReturn */
9242 s->cur_prompt = new_prompts(ssh->frontend);
9243 s->cur_prompt->to_server = TRUE;
9244 s->cur_prompt->name = dupstr("SSH login name");
9245 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
9246 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9249 crWaitUntilV(!pktin);
9250 ret = get_userpass_input(s->cur_prompt, in, inlen);
9255 * get_userpass_input() failed to get a username.
9258 free_prompts(s->cur_prompt);
9259 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
9262 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
9263 free_prompts(s->cur_prompt);
9266 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
9267 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
9268 c_write_str(ssh, stuff);
9272 s->got_username = TRUE;
9275 * Send an authentication request using method "none": (a)
9276 * just in case it succeeds, and (b) so that we know what
9277 * authentication methods we can usefully try next.
9279 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9281 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9282 ssh2_pkt_addstring(s->pktout, ssh->username);
9283 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
9284 ssh2_pkt_addstring(s->pktout, "none"); /* method */
9285 ssh2_pkt_send(ssh, s->pktout);
9286 s->type = AUTH_TYPE_NONE;
9288 s->we_are_in = FALSE;
9290 s->tried_pubkey_config = FALSE;
9291 s->kbd_inter_refused = FALSE;
9293 /* Reset agent request state. */
9294 s->done_agent = FALSE;
9295 if (s->agent_response) {
9296 if (s->pkblob_in_agent) {
9297 s->agentp = s->pkblob_in_agent;
9299 s->agentp = s->agent_response + 5 + 4;
9305 char *methods = NULL;
9309 * Wait for the result of the last authentication request.
9312 crWaitUntilV(pktin);
9314 * Now is a convenient point to spew any banner material
9315 * that we've accumulated. (This should ensure that when
9316 * we exit the auth loop, we haven't any left to deal
9320 int size = bufchain_size(&ssh->banner);
9322 * Don't show the banner if we're operating in
9323 * non-verbose non-interactive mode. (It's probably
9324 * a script, which means nobody will read the
9325 * banner _anyway_, and moreover the printing of
9326 * the banner will screw up processing on the
9327 * output of (say) plink.)
9329 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
9330 char *banner = snewn(size, char);
9331 bufchain_fetch(&ssh->banner, banner, size);
9332 c_write_untrusted(ssh, banner, size);
9335 bufchain_clear(&ssh->banner);
9337 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
9338 logevent("Access granted");
9339 s->we_are_in = s->userauth_success = TRUE;
9343 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
9344 bombout(("Strange packet received during authentication: "
9345 "type %d", pktin->type));
9352 * OK, we're now sitting on a USERAUTH_FAILURE message, so
9353 * we can look at the string in it and know what we can
9354 * helpfully try next.
9356 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
9357 ssh_pkt_getstring(pktin, &methods, &methlen);
9358 if (!ssh2_pkt_getbool(pktin)) {
9360 * We have received an unequivocal Access
9361 * Denied. This can translate to a variety of
9362 * messages, or no message at all.
9364 * For forms of authentication which are attempted
9365 * implicitly, by which I mean without printing
9366 * anything in the window indicating that we're
9367 * trying them, we should never print 'Access
9370 * If we do print a message saying that we're
9371 * attempting some kind of authentication, it's OK
9372 * to print a followup message saying it failed -
9373 * but the message may sometimes be more specific
9374 * than simply 'Access denied'.
9376 * Additionally, if we'd just tried password
9377 * authentication, we should break out of this
9378 * whole loop so as to go back to the username
9379 * prompt (iff we're configured to allow
9380 * username change attempts).
9382 if (s->type == AUTH_TYPE_NONE) {
9384 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
9385 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
9386 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
9387 c_write_str(ssh, "Server refused our key\r\n");
9388 logevent("Server refused our key");
9389 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
9390 /* This _shouldn't_ happen except by a
9391 * protocol bug causing client and server to
9392 * disagree on what is a correct signature. */
9393 c_write_str(ssh, "Server refused public-key signature"
9394 " despite accepting key!\r\n");
9395 logevent("Server refused public-key signature"
9396 " despite accepting key!");
9397 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
9398 /* quiet, so no c_write */
9399 logevent("Server refused keyboard-interactive authentication");
9400 } else if (s->type==AUTH_TYPE_GSSAPI) {
9401 /* always quiet, so no c_write */
9402 /* also, the code down in the GSSAPI block has
9403 * already logged this in the Event Log */
9404 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
9405 logevent("Keyboard-interactive authentication failed");
9406 c_write_str(ssh, "Access denied\r\n");
9408 assert(s->type == AUTH_TYPE_PASSWORD);
9409 logevent("Password authentication failed");
9410 c_write_str(ssh, "Access denied\r\n");
9412 if (conf_get_int(ssh->conf, CONF_change_username)) {
9413 /* XXX perhaps we should allow
9414 * keyboard-interactive to do this too? */
9415 s->we_are_in = FALSE;
9420 c_write_str(ssh, "Further authentication required\r\n");
9421 logevent("Further authentication required");
9425 in_commasep_string("publickey", methods, methlen);
9427 in_commasep_string("password", methods, methlen);
9428 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
9429 in_commasep_string("keyboard-interactive", methods, methlen);
9431 if (conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
9432 in_commasep_string("gssapi-with-mic", methods, methlen)) {
9433 /* Try loading the GSS libraries and see if we
9436 ssh->gsslibs = ssh_gss_setup(ssh->conf);
9437 s->can_gssapi = (ssh->gsslibs->nlibraries > 0);
9439 /* No point in even bothering to try to load the
9440 * GSS libraries, if the user configuration and
9441 * server aren't both prepared to attempt GSSAPI
9442 * auth in the first place. */
9443 s->can_gssapi = FALSE;
9448 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9450 if (s->can_pubkey && !s->done_agent && s->nkeys) {
9453 * Attempt public-key authentication using a key from Pageant.
9456 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9458 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
9460 /* Unpack key from agent response */
9461 s->pklen = toint(GET_32BIT(s->agentp));
9463 s->pkblob = (char *)s->agentp;
9464 s->agentp += s->pklen;
9465 s->alglen = toint(GET_32BIT(s->pkblob));
9466 s->alg = s->pkblob + 4;
9467 s->commentlen = toint(GET_32BIT(s->agentp));
9469 s->commentp = (char *)s->agentp;
9470 s->agentp += s->commentlen;
9471 /* s->agentp now points at next key, if any */
9473 /* See if server will accept it */
9474 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9475 ssh2_pkt_addstring(s->pktout, ssh->username);
9476 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9477 /* service requested */
9478 ssh2_pkt_addstring(s->pktout, "publickey");
9480 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
9481 ssh2_pkt_addstring_start(s->pktout);
9482 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9483 ssh2_pkt_addstring_start(s->pktout);
9484 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9485 ssh2_pkt_send(ssh, s->pktout);
9486 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
9488 crWaitUntilV(pktin);
9489 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9491 /* Offer of key refused. */
9498 if (flags & FLAG_VERBOSE) {
9499 c_write_str(ssh, "Authenticating with "
9501 c_write(ssh, s->commentp, s->commentlen);
9502 c_write_str(ssh, "\" from agent\r\n");
9506 * Server is willing to accept the key.
9507 * Construct a SIGN_REQUEST.
9509 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9510 ssh2_pkt_addstring(s->pktout, ssh->username);
9511 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9512 /* service requested */
9513 ssh2_pkt_addstring(s->pktout, "publickey");
9515 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
9516 ssh2_pkt_addstring_start(s->pktout);
9517 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9518 ssh2_pkt_addstring_start(s->pktout);
9519 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9521 /* Ask agent for signature. */
9522 s->siglen = s->pktout->length - 5 + 4 +
9523 ssh->v2_session_id_len;
9524 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9526 s->len = 1; /* message type */
9527 s->len += 4 + s->pklen; /* key blob */
9528 s->len += 4 + s->siglen; /* data to sign */
9529 s->len += 4; /* flags */
9530 s->agentreq = snewn(4 + s->len, char);
9531 PUT_32BIT(s->agentreq, s->len);
9532 s->q = s->agentreq + 4;
9533 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
9534 PUT_32BIT(s->q, s->pklen);
9536 memcpy(s->q, s->pkblob, s->pklen);
9538 PUT_32BIT(s->q, s->siglen);
9540 /* Now the data to be signed... */
9541 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9542 PUT_32BIT(s->q, ssh->v2_session_id_len);
9545 memcpy(s->q, ssh->v2_session_id,
9546 ssh->v2_session_id_len);
9547 s->q += ssh->v2_session_id_len;
9548 memcpy(s->q, s->pktout->data + 5,
9549 s->pktout->length - 5);
9550 s->q += s->pktout->length - 5;
9551 /* And finally the (zero) flags word. */
9553 if (!agent_query(s->agentreq, s->len + 4,
9555 ssh_agent_callback, ssh)) {
9559 bombout(("Unexpected data from server"
9560 " while waiting for agent"
9564 } while (pktin || inlen > 0);
9565 vret = ssh->agent_response;
9566 s->retlen = ssh->agent_response_len;
9571 if (s->retlen >= 9 &&
9572 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
9573 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
9574 logevent("Sending Pageant's response");
9575 ssh2_add_sigblob(ssh, s->pktout,
9576 s->pkblob, s->pklen,
9578 GET_32BIT(s->ret + 5));
9579 ssh2_pkt_send(ssh, s->pktout);
9580 s->type = AUTH_TYPE_PUBLICKEY;
9582 /* FIXME: less drastic response */
9583 bombout(("Pageant failed to answer challenge"));
9589 /* Do we have any keys left to try? */
9590 if (s->pkblob_in_agent) {
9591 s->done_agent = TRUE;
9592 s->tried_pubkey_config = TRUE;
9595 if (s->keyi >= s->nkeys)
9596 s->done_agent = TRUE;
9599 } else if (s->can_pubkey && s->publickey_blob &&
9600 s->privatekey_available && !s->tried_pubkey_config) {
9602 struct ssh2_userkey *key; /* not live over crReturn */
9603 char *passphrase; /* not live over crReturn */
9605 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9607 s->tried_pubkey_config = TRUE;
9610 * Try the public key supplied in the configuration.
9612 * First, offer the public blob to see if the server is
9613 * willing to accept it.
9615 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9616 ssh2_pkt_addstring(s->pktout, ssh->username);
9617 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9618 /* service requested */
9619 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
9620 ssh2_pkt_addbool(s->pktout, FALSE);
9621 /* no signature included */
9622 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
9623 ssh2_pkt_addstring_start(s->pktout);
9624 ssh2_pkt_addstring_data(s->pktout,
9625 (char *)s->publickey_blob,
9626 s->publickey_bloblen);
9627 ssh2_pkt_send(ssh, s->pktout);
9628 logevent("Offered public key");
9630 crWaitUntilV(pktin);
9631 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9632 /* Key refused. Give up. */
9633 s->gotit = TRUE; /* reconsider message next loop */
9634 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
9635 continue; /* process this new message */
9637 logevent("Offer of public key accepted");
9640 * Actually attempt a serious authentication using
9643 if (flags & FLAG_VERBOSE) {
9644 c_write_str(ssh, "Authenticating with public key \"");
9645 c_write_str(ssh, s->publickey_comment);
9646 c_write_str(ssh, "\"\r\n");
9650 const char *error; /* not live over crReturn */
9651 if (s->privatekey_encrypted) {
9653 * Get a passphrase from the user.
9655 int ret; /* need not be kept over crReturn */
9656 s->cur_prompt = new_prompts(ssh->frontend);
9657 s->cur_prompt->to_server = FALSE;
9658 s->cur_prompt->name = dupstr("SSH key passphrase");
9659 add_prompt(s->cur_prompt,
9660 dupprintf("Passphrase for key \"%.100s\": ",
9661 s->publickey_comment),
9663 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9666 crWaitUntilV(!pktin);
9667 ret = get_userpass_input(s->cur_prompt,
9672 /* Failed to get a passphrase. Terminate. */
9673 free_prompts(s->cur_prompt);
9674 ssh_disconnect(ssh, NULL,
9675 "Unable to authenticate",
9676 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9681 dupstr(s->cur_prompt->prompts[0]->result);
9682 free_prompts(s->cur_prompt);
9684 passphrase = NULL; /* no passphrase needed */
9688 * Try decrypting the key.
9690 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9691 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
9693 /* burn the evidence */
9694 smemclr(passphrase, strlen(passphrase));
9697 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
9699 (key == SSH2_WRONG_PASSPHRASE)) {
9700 c_write_str(ssh, "Wrong passphrase\r\n");
9702 /* and loop again */
9704 c_write_str(ssh, "Unable to load private key (");
9705 c_write_str(ssh, error);
9706 c_write_str(ssh, ")\r\n");
9708 break; /* try something else */
9714 unsigned char *pkblob, *sigblob, *sigdata;
9715 int pkblob_len, sigblob_len, sigdata_len;
9719 * We have loaded the private key and the server
9720 * has announced that it's willing to accept it.
9721 * Hallelujah. Generate a signature and send it.
9723 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9724 ssh2_pkt_addstring(s->pktout, ssh->username);
9725 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9726 /* service requested */
9727 ssh2_pkt_addstring(s->pktout, "publickey");
9729 ssh2_pkt_addbool(s->pktout, TRUE);
9730 /* signature follows */
9731 ssh2_pkt_addstring(s->pktout, key->alg->name);
9732 pkblob = key->alg->public_blob(key->data,
9734 ssh2_pkt_addstring_start(s->pktout);
9735 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
9739 * The data to be signed is:
9743 * followed by everything so far placed in the
9746 sigdata_len = s->pktout->length - 5 + 4 +
9747 ssh->v2_session_id_len;
9748 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9750 sigdata = snewn(sigdata_len, unsigned char);
9752 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9753 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
9756 memcpy(sigdata+p, ssh->v2_session_id,
9757 ssh->v2_session_id_len);
9758 p += ssh->v2_session_id_len;
9759 memcpy(sigdata+p, s->pktout->data + 5,
9760 s->pktout->length - 5);
9761 p += s->pktout->length - 5;
9762 assert(p == sigdata_len);
9763 sigblob = key->alg->sign(key->data, (char *)sigdata,
9764 sigdata_len, &sigblob_len);
9765 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
9766 sigblob, sigblob_len);
9771 ssh2_pkt_send(ssh, s->pktout);
9772 logevent("Sent public key signature");
9773 s->type = AUTH_TYPE_PUBLICKEY;
9774 key->alg->freekey(key->data);
9775 sfree(key->comment);
9780 } else if (s->can_gssapi && !s->tried_gssapi) {
9782 /* GSSAPI Authentication */
9787 s->type = AUTH_TYPE_GSSAPI;
9788 s->tried_gssapi = TRUE;
9790 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
9793 * Pick the highest GSS library on the preference
9799 for (i = 0; i < ngsslibs; i++) {
9800 int want_id = conf_get_int_int(ssh->conf,
9801 CONF_ssh_gsslist, i);
9802 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
9803 if (ssh->gsslibs->libraries[j].id == want_id) {
9804 s->gsslib = &ssh->gsslibs->libraries[j];
9805 goto got_gsslib; /* double break */
9810 * We always expect to have found something in
9811 * the above loop: we only came here if there
9812 * was at least one viable GSS library, and the
9813 * preference list should always mention
9814 * everything and only change the order.
9819 if (s->gsslib->gsslogmsg)
9820 logevent(s->gsslib->gsslogmsg);
9822 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
9823 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9824 ssh2_pkt_addstring(s->pktout, ssh->username);
9825 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9826 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
9827 logevent("Attempting GSSAPI authentication");
9829 /* add mechanism info */
9830 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
9832 /* number of GSSAPI mechanisms */
9833 ssh2_pkt_adduint32(s->pktout,1);
9835 /* length of OID + 2 */
9836 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
9837 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
9840 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
9842 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
9844 ssh2_pkt_send(ssh, s->pktout);
9845 crWaitUntilV(pktin);
9846 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
9847 logevent("GSSAPI authentication request refused");
9851 /* check returned packet ... */
9853 ssh_pkt_getstring(pktin, &data, &len);
9854 s->gss_rcvtok.value = data;
9855 s->gss_rcvtok.length = len;
9856 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
9857 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
9858 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
9859 memcmp((char *)s->gss_rcvtok.value + 2,
9860 s->gss_buf.value,s->gss_buf.length) ) {
9861 logevent("GSSAPI authentication - wrong response from server");
9865 /* now start running */
9866 s->gss_stat = s->gsslib->import_name(s->gsslib,
9869 if (s->gss_stat != SSH_GSS_OK) {
9870 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
9871 logevent("GSSAPI import name failed - Bad service name");
9873 logevent("GSSAPI import name failed");
9877 /* fetch TGT into GSS engine */
9878 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
9880 if (s->gss_stat != SSH_GSS_OK) {
9881 logevent("GSSAPI authentication failed to get credentials");
9882 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9886 /* initial tokens are empty */
9887 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
9888 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
9890 /* now enter the loop */
9892 s->gss_stat = s->gsslib->init_sec_context
9896 conf_get_int(ssh->conf, CONF_gssapifwd),
9900 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
9901 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
9902 logevent("GSSAPI authentication initialisation failed");
9904 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
9905 &s->gss_buf) == SSH_GSS_OK) {
9906 logevent(s->gss_buf.value);
9907 sfree(s->gss_buf.value);
9912 logevent("GSSAPI authentication initialised");
9914 /* Client and server now exchange tokens until GSSAPI
9915 * no longer says CONTINUE_NEEDED */
9917 if (s->gss_sndtok.length != 0) {
9918 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
9919 ssh_pkt_addstring_start(s->pktout);
9920 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
9921 ssh2_pkt_send(ssh, s->pktout);
9922 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
9925 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
9926 crWaitUntilV(pktin);
9927 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
9928 logevent("GSSAPI authentication - bad server response");
9929 s->gss_stat = SSH_GSS_FAILURE;
9932 ssh_pkt_getstring(pktin, &data, &len);
9933 s->gss_rcvtok.value = data;
9934 s->gss_rcvtok.length = len;
9936 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
9938 if (s->gss_stat != SSH_GSS_OK) {
9939 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9940 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9943 logevent("GSSAPI authentication loop finished OK");
9945 /* Now send the MIC */
9947 s->pktout = ssh2_pkt_init(0);
9948 micoffset = s->pktout->length;
9949 ssh_pkt_addstring_start(s->pktout);
9950 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
9951 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
9952 ssh_pkt_addstring(s->pktout, ssh->username);
9953 ssh_pkt_addstring(s->pktout, "ssh-connection");
9954 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
9956 s->gss_buf.value = (char *)s->pktout->data + micoffset;
9957 s->gss_buf.length = s->pktout->length - micoffset;
9959 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
9960 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
9961 ssh_pkt_addstring_start(s->pktout);
9962 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
9963 ssh2_pkt_send(ssh, s->pktout);
9964 s->gsslib->free_mic(s->gsslib, &mic);
9968 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9969 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9972 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
9975 * Keyboard-interactive authentication.
9978 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
9980 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
9982 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9983 ssh2_pkt_addstring(s->pktout, ssh->username);
9984 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9985 /* service requested */
9986 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
9988 ssh2_pkt_addstring(s->pktout, ""); /* lang */
9989 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
9990 ssh2_pkt_send(ssh, s->pktout);
9992 logevent("Attempting keyboard-interactive authentication");
9994 crWaitUntilV(pktin);
9995 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
9996 /* Server is not willing to do keyboard-interactive
9997 * at all (or, bizarrely but legally, accepts the
9998 * user without actually issuing any prompts).
9999 * Give up on it entirely. */
10001 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
10002 s->kbd_inter_refused = TRUE; /* don't try it again */
10007 * Loop while the server continues to send INFO_REQUESTs.
10009 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
10011 char *name, *inst, *lang;
10012 int name_len, inst_len, lang_len;
10016 * We've got a fresh USERAUTH_INFO_REQUEST.
10017 * Get the preamble and start building a prompt.
10019 ssh_pkt_getstring(pktin, &name, &name_len);
10020 ssh_pkt_getstring(pktin, &inst, &inst_len);
10021 ssh_pkt_getstring(pktin, &lang, &lang_len);
10022 s->cur_prompt = new_prompts(ssh->frontend);
10023 s->cur_prompt->to_server = TRUE;
10026 * Get any prompt(s) from the packet.
10028 s->num_prompts = ssh_pkt_getuint32(pktin);
10029 for (i = 0; i < s->num_prompts; i++) {
10033 static char noprompt[] =
10034 "<server failed to send prompt>: ";
10036 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
10037 echo = ssh2_pkt_getbool(pktin);
10040 prompt_len = lenof(noprompt)-1;
10042 add_prompt(s->cur_prompt,
10043 dupprintf("%.*s", prompt_len, prompt),
10048 /* FIXME: better prefix to distinguish from
10049 * local prompts? */
10050 s->cur_prompt->name =
10051 dupprintf("SSH server: %.*s", name_len, name);
10052 s->cur_prompt->name_reqd = TRUE;
10054 s->cur_prompt->name =
10055 dupstr("SSH server authentication");
10056 s->cur_prompt->name_reqd = FALSE;
10058 /* We add a prefix to try to make it clear that a prompt
10059 * has come from the server.
10060 * FIXME: ugly to print "Using..." in prompt _every_
10061 * time round. Can this be done more subtly? */
10062 /* Special case: for reasons best known to themselves,
10063 * some servers send k-i requests with no prompts and
10064 * nothing to display. Keep quiet in this case. */
10065 if (s->num_prompts || name_len || inst_len) {
10066 s->cur_prompt->instruction =
10067 dupprintf("Using keyboard-interactive authentication.%s%.*s",
10068 inst_len ? "\n" : "", inst_len, inst);
10069 s->cur_prompt->instr_reqd = TRUE;
10071 s->cur_prompt->instr_reqd = FALSE;
10075 * Display any instructions, and get the user's
10079 int ret; /* not live over crReturn */
10080 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10083 crWaitUntilV(!pktin);
10084 ret = get_userpass_input(s->cur_prompt, in, inlen);
10089 * Failed to get responses. Terminate.
10091 free_prompts(s->cur_prompt);
10092 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10093 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10100 * Send the response(s) to the server.
10102 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
10103 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
10104 for (i=0; i < s->num_prompts; i++) {
10105 ssh2_pkt_addstring(s->pktout,
10106 s->cur_prompt->prompts[i]->result);
10108 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10111 * Free the prompts structure from this iteration.
10112 * If there's another, a new one will be allocated
10113 * when we return to the top of this while loop.
10115 free_prompts(s->cur_prompt);
10118 * Get the next packet in case it's another
10121 crWaitUntilV(pktin);
10126 * We should have SUCCESS or FAILURE now.
10130 } else if (s->can_passwd) {
10133 * Plain old password authentication.
10135 int ret; /* not live over crReturn */
10136 int changereq_first_time; /* not live over crReturn */
10138 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
10140 s->cur_prompt = new_prompts(ssh->frontend);
10141 s->cur_prompt->to_server = TRUE;
10142 s->cur_prompt->name = dupstr("SSH password");
10143 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
10148 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10151 crWaitUntilV(!pktin);
10152 ret = get_userpass_input(s->cur_prompt, in, inlen);
10157 * Failed to get responses. Terminate.
10159 free_prompts(s->cur_prompt);
10160 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10161 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10166 * Squirrel away the password. (We may need it later if
10167 * asked to change it.)
10169 s->password = dupstr(s->cur_prompt->prompts[0]->result);
10170 free_prompts(s->cur_prompt);
10173 * Send the password packet.
10175 * We pad out the password packet to 256 bytes to make
10176 * it harder for an attacker to find the length of the
10179 * Anyone using a password longer than 256 bytes
10180 * probably doesn't have much to worry about from
10181 * people who find out how long their password is!
10183 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10184 ssh2_pkt_addstring(s->pktout, ssh->username);
10185 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10186 /* service requested */
10187 ssh2_pkt_addstring(s->pktout, "password");
10188 ssh2_pkt_addbool(s->pktout, FALSE);
10189 ssh2_pkt_addstring(s->pktout, s->password);
10190 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10191 logevent("Sent password");
10192 s->type = AUTH_TYPE_PASSWORD;
10195 * Wait for next packet, in case it's a password change
10198 crWaitUntilV(pktin);
10199 changereq_first_time = TRUE;
10201 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
10204 * We're being asked for a new password
10205 * (perhaps not for the first time).
10206 * Loop until the server accepts it.
10209 int got_new = FALSE; /* not live over crReturn */
10210 char *prompt; /* not live over crReturn */
10211 int prompt_len; /* not live over crReturn */
10215 if (changereq_first_time)
10216 msg = "Server requested password change";
10218 msg = "Server rejected new password";
10220 c_write_str(ssh, msg);
10221 c_write_str(ssh, "\r\n");
10224 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
10226 s->cur_prompt = new_prompts(ssh->frontend);
10227 s->cur_prompt->to_server = TRUE;
10228 s->cur_prompt->name = dupstr("New SSH password");
10229 s->cur_prompt->instruction =
10230 dupprintf("%.*s", prompt_len, prompt);
10231 s->cur_prompt->instr_reqd = TRUE;
10233 * There's no explicit requirement in the protocol
10234 * for the "old" passwords in the original and
10235 * password-change messages to be the same, and
10236 * apparently some Cisco kit supports password change
10237 * by the user entering a blank password originally
10238 * and the real password subsequently, so,
10239 * reluctantly, we prompt for the old password again.
10241 * (On the other hand, some servers don't even bother
10242 * to check this field.)
10244 add_prompt(s->cur_prompt,
10245 dupstr("Current password (blank for previously entered password): "),
10247 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
10249 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
10253 * Loop until the user manages to enter the same
10258 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10261 crWaitUntilV(!pktin);
10262 ret = get_userpass_input(s->cur_prompt, in, inlen);
10267 * Failed to get responses. Terminate.
10269 /* burn the evidence */
10270 free_prompts(s->cur_prompt);
10271 smemclr(s->password, strlen(s->password));
10272 sfree(s->password);
10273 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10274 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10280 * If the user specified a new original password
10281 * (IYSWIM), overwrite any previously specified
10283 * (A side effect is that the user doesn't have to
10284 * re-enter it if they louse up the new password.)
10286 if (s->cur_prompt->prompts[0]->result[0]) {
10287 smemclr(s->password, strlen(s->password));
10288 /* burn the evidence */
10289 sfree(s->password);
10291 dupstr(s->cur_prompt->prompts[0]->result);
10295 * Check the two new passwords match.
10297 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
10298 s->cur_prompt->prompts[2]->result)
10301 /* They don't. Silly user. */
10302 c_write_str(ssh, "Passwords do not match\r\n");
10307 * Send the new password (along with the old one).
10308 * (see above for padding rationale)
10310 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10311 ssh2_pkt_addstring(s->pktout, ssh->username);
10312 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10313 /* service requested */
10314 ssh2_pkt_addstring(s->pktout, "password");
10315 ssh2_pkt_addbool(s->pktout, TRUE);
10316 ssh2_pkt_addstring(s->pktout, s->password);
10317 ssh2_pkt_addstring(s->pktout,
10318 s->cur_prompt->prompts[1]->result);
10319 free_prompts(s->cur_prompt);
10320 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10321 logevent("Sent new password");
10324 * Now see what the server has to say about it.
10325 * (If it's CHANGEREQ again, it's not happy with the
10328 crWaitUntilV(pktin);
10329 changereq_first_time = FALSE;
10334 * We need to reexamine the current pktin at the top
10335 * of the loop. Either:
10336 * - we weren't asked to change password at all, in
10337 * which case it's a SUCCESS or FAILURE with the
10339 * - we sent a new password, and the server was
10340 * either OK with it (SUCCESS or FAILURE w/partial
10341 * success) or unhappy with the _old_ password
10342 * (FAILURE w/o partial success)
10343 * In any of these cases, we go back to the top of
10344 * the loop and start again.
10349 * We don't need the old password any more, in any
10350 * case. Burn the evidence.
10352 smemclr(s->password, strlen(s->password));
10353 sfree(s->password);
10356 char *str = dupprintf("No supported authentication methods available"
10357 " (server sent: %.*s)",
10360 ssh_disconnect(ssh, str,
10361 "No supported authentication methods available",
10362 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
10372 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
10374 /* Clear up various bits and pieces from authentication. */
10375 if (s->publickey_blob) {
10376 sfree(s->publickey_algorithm);
10377 sfree(s->publickey_blob);
10378 sfree(s->publickey_comment);
10380 if (s->agent_response)
10381 sfree(s->agent_response);
10383 if (s->userauth_success && !ssh->bare_connection) {
10385 * We've just received USERAUTH_SUCCESS, and we haven't sent any
10386 * packets since. Signal the transport layer to consider enacting
10387 * delayed compression.
10389 * (Relying on we_are_in is not sufficient, as
10390 * draft-miller-secsh-compression-delayed is quite clear that it
10391 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
10392 * become set for other reasons.)
10394 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
10397 ssh->channels = newtree234(ssh_channelcmp);
10400 * Set up handlers for some connection protocol messages, so we
10401 * don't have to handle them repeatedly in this coroutine.
10403 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
10404 ssh2_msg_channel_window_adjust;
10405 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
10406 ssh2_msg_global_request;
10409 * Create the main session channel.
10411 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
10412 ssh->mainchan = NULL;
10414 ssh->mainchan = snew(struct ssh_channel);
10415 ssh->mainchan->ssh = ssh;
10416 ssh2_channel_init(ssh->mainchan);
10418 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
10420 * Just start a direct-tcpip channel and use it as the main
10423 ssh_send_port_open(ssh->mainchan,
10424 conf_get_str(ssh->conf, CONF_ssh_nc_host),
10425 conf_get_int(ssh->conf, CONF_ssh_nc_port),
10427 ssh->ncmode = TRUE;
10429 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
10430 logevent("Opening session as main channel");
10431 ssh2_pkt_send(ssh, s->pktout);
10432 ssh->ncmode = FALSE;
10434 crWaitUntilV(pktin);
10435 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
10436 bombout(("Server refused to open channel"));
10438 /* FIXME: error data comes back in FAILURE packet */
10440 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
10441 bombout(("Server's channel confirmation cited wrong channel"));
10444 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
10445 ssh->mainchan->halfopen = FALSE;
10446 ssh->mainchan->type = CHAN_MAINSESSION;
10447 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
10448 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
10449 add234(ssh->channels, ssh->mainchan);
10450 update_specials_menu(ssh->frontend);
10451 logevent("Opened main channel");
10455 * Now we have a channel, make dispatch table entries for
10456 * general channel-based messages.
10458 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
10459 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
10460 ssh2_msg_channel_data;
10461 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
10462 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
10463 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
10464 ssh2_msg_channel_open_confirmation;
10465 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
10466 ssh2_msg_channel_open_failure;
10467 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
10468 ssh2_msg_channel_request;
10469 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
10470 ssh2_msg_channel_open;
10471 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
10472 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
10475 * Now the connection protocol is properly up and running, with
10476 * all those dispatch table entries, so it's safe to let
10477 * downstreams start trying to open extra channels through us.
10479 if (ssh->connshare)
10480 share_activate(ssh->connshare, ssh->v_s);
10482 if (ssh->mainchan && ssh_is_simple(ssh)) {
10484 * This message indicates to the server that we promise
10485 * not to try to run any other channel in parallel with
10486 * this one, so it's safe for it to advertise a very large
10487 * window and leave the flow control to TCP.
10489 s->pktout = ssh2_chanreq_init(ssh->mainchan,
10490 "simple@putty.projects.tartarus.org",
10492 ssh2_pkt_send(ssh, s->pktout);
10496 * Enable port forwardings.
10498 ssh_setup_portfwd(ssh, ssh->conf);
10500 if (ssh->mainchan && !ssh->ncmode) {
10502 * Send the CHANNEL_REQUESTS for the main session channel.
10503 * Each one is handled by its own little asynchronous
10507 /* Potentially enable X11 forwarding. */
10508 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
10510 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
10512 if (!ssh->x11disp) {
10513 /* FIXME: return an error message from x11_setup_display */
10514 logevent("X11 forwarding not enabled: unable to"
10515 " initialise X display");
10517 ssh->x11auth = x11_invent_fake_auth
10518 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
10519 ssh->x11auth->disp = ssh->x11disp;
10521 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
10525 /* Potentially enable agent forwarding. */
10526 if (ssh_agent_forwarding_permitted(ssh))
10527 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
10529 /* Now allocate a pty for the session. */
10530 if (!conf_get_int(ssh->conf, CONF_nopty))
10531 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
10533 /* Send environment variables. */
10534 ssh2_setup_env(ssh->mainchan, NULL, NULL);
10537 * Start a shell or a remote command. We may have to attempt
10538 * this twice if the config data has provided a second choice
10545 if (ssh->fallback_cmd) {
10546 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
10547 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
10549 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
10550 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
10554 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
10555 ssh2_response_authconn, NULL);
10556 ssh2_pkt_addstring(s->pktout, cmd);
10558 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
10559 ssh2_response_authconn, NULL);
10560 ssh2_pkt_addstring(s->pktout, cmd);
10562 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
10563 ssh2_response_authconn, NULL);
10565 ssh2_pkt_send(ssh, s->pktout);
10567 crWaitUntilV(pktin);
10569 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
10570 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
10571 bombout(("Unexpected response to shell/command request:"
10572 " packet type %d", pktin->type));
10576 * We failed to start the command. If this is the
10577 * fallback command, we really are finished; if it's
10578 * not, and if the fallback command exists, try falling
10579 * back to it before complaining.
10581 if (!ssh->fallback_cmd &&
10582 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
10583 logevent("Primary command failed; attempting fallback");
10584 ssh->fallback_cmd = TRUE;
10587 bombout(("Server refused to start a shell/command"));
10590 logevent("Started a shell/command");
10595 ssh->editing = ssh->echoing = TRUE;
10598 ssh->state = SSH_STATE_SESSION;
10599 if (ssh->size_needed)
10600 ssh_size(ssh, ssh->term_width, ssh->term_height);
10601 if (ssh->eof_needed)
10602 ssh_special(ssh, TS_EOF);
10608 ldisc_echoedit_update(ssh->ldisc); /* cause ldisc to notice changes */
10613 s->try_send = FALSE;
10617 * _All_ the connection-layer packets we expect to
10618 * receive are now handled by the dispatch table.
10619 * Anything that reaches here must be bogus.
10622 bombout(("Strange packet received: type %d", pktin->type));
10624 } else if (ssh->mainchan) {
10626 * We have spare data. Add it to the channel buffer.
10628 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
10629 s->try_send = TRUE;
10633 struct ssh_channel *c;
10635 * Try to send data on all channels if we can.
10637 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
10638 if (c->type != CHAN_SHARING)
10639 ssh2_try_send_and_unthrottle(ssh, c);
10647 * Handlers for SSH-2 messages that might arrive at any moment.
10649 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
10651 /* log reason code in disconnect message */
10653 int reason, msglen;
10655 reason = ssh_pkt_getuint32(pktin);
10656 ssh_pkt_getstring(pktin, &msg, &msglen);
10658 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
10659 buf = dupprintf("Received disconnect message (%s)",
10660 ssh2_disconnect_reasons[reason]);
10662 buf = dupprintf("Received disconnect message (unknown"
10663 " type %d)", reason);
10667 buf = dupprintf("Disconnection message text: %.*s",
10670 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
10672 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
10673 ssh2_disconnect_reasons[reason] : "unknown",
10678 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
10680 /* log the debug message */
10684 /* XXX maybe we should actually take notice of the return value */
10685 ssh2_pkt_getbool(pktin);
10686 ssh_pkt_getstring(pktin, &msg, &msglen);
10688 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
10691 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
10693 do_ssh2_transport(ssh, NULL, 0, pktin);
10697 * Called if we receive a packet that isn't allowed by the protocol.
10698 * This only applies to packets whose meaning PuTTY understands.
10699 * Entirely unknown packets are handled below.
10701 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
10703 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
10704 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
10706 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
10710 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
10712 struct Packet *pktout;
10713 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
10714 ssh2_pkt_adduint32(pktout, pktin->sequence);
10716 * UNIMPLEMENTED messages MUST appear in the same order as the
10717 * messages they respond to. Hence, never queue them.
10719 ssh2_pkt_send_noqueue(ssh, pktout);
10723 * Handle the top-level SSH-2 protocol.
10725 static void ssh2_protocol_setup(Ssh ssh)
10730 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10732 for (i = 0; i < 256; i++)
10733 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10736 * Initially, we only accept transport messages (and a few generic
10737 * ones). do_ssh2_authconn will add more when it starts.
10738 * Messages that are understood but not currently acceptable go to
10739 * ssh2_msg_unexpected.
10741 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10742 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
10743 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
10744 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
10745 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
10746 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
10747 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
10748 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
10749 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
10750 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
10751 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
10752 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
10753 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
10754 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
10755 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
10756 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
10757 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
10758 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
10759 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
10760 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10761 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10762 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10763 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10764 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10765 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10766 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10767 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10768 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10769 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10770 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10771 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10772 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10773 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10776 * These messages have a special handler from the start.
10778 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10779 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
10780 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10783 static void ssh2_bare_connection_protocol_setup(Ssh ssh)
10788 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10790 for (i = 0; i < 256; i++)
10791 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10794 * Initially, we set all ssh-connection messages to 'unexpected';
10795 * do_ssh2_authconn will fill things in properly. We also handle a
10796 * couple of messages from the transport protocol which aren't
10797 * related to key exchange (UNIMPLEMENTED, IGNORE, DEBUG,
10800 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10801 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10802 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10803 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10804 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10805 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10806 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10807 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10808 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10809 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10810 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10811 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10812 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10813 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10815 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10818 * These messages have a special handler from the start.
10820 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10821 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore;
10822 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10825 static void ssh2_timer(void *ctx, unsigned long now)
10827 Ssh ssh = (Ssh)ctx;
10829 if (ssh->state == SSH_STATE_CLOSED)
10832 if (!ssh->kex_in_progress && !ssh->bare_connection &&
10833 conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
10834 now == ssh->next_rekey) {
10835 do_ssh2_transport(ssh, "timeout", -1, NULL);
10839 static void ssh2_protocol(Ssh ssh, const void *vin, int inlen,
10840 struct Packet *pktin)
10842 const unsigned char *in = (const unsigned char *)vin;
10843 if (ssh->state == SSH_STATE_CLOSED)
10847 ssh->incoming_data_size += pktin->encrypted_len;
10848 if (!ssh->kex_in_progress &&
10849 ssh->max_data_size != 0 &&
10850 ssh->incoming_data_size > ssh->max_data_size)
10851 do_ssh2_transport(ssh, "too much data received", -1, NULL);
10855 ssh->packet_dispatch[pktin->type](ssh, pktin);
10856 else if (!ssh->protocol_initial_phase_done)
10857 do_ssh2_transport(ssh, in, inlen, pktin);
10859 do_ssh2_authconn(ssh, in, inlen, pktin);
10862 static void ssh2_bare_connection_protocol(Ssh ssh, const void *vin, int inlen,
10863 struct Packet *pktin)
10865 const unsigned char *in = (const unsigned char *)vin;
10866 if (ssh->state == SSH_STATE_CLOSED)
10870 ssh->packet_dispatch[pktin->type](ssh, pktin);
10872 do_ssh2_authconn(ssh, in, inlen, pktin);
10875 static void ssh_cache_conf_values(Ssh ssh)
10877 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
10881 * Called to set up the connection.
10883 * Returns an error message, or NULL on success.
10885 static const char *ssh_init(void *frontend_handle, void **backend_handle,
10887 const char *host, int port, char **realhost,
10888 int nodelay, int keepalive)
10893 ssh = snew(struct ssh_tag);
10894 ssh->conf = conf_copy(conf);
10895 ssh_cache_conf_values(ssh);
10896 ssh->version = 0; /* when not ready yet */
10898 ssh->cipher = NULL;
10899 ssh->v1_cipher_ctx = NULL;
10900 ssh->crcda_ctx = NULL;
10901 ssh->cscipher = NULL;
10902 ssh->cs_cipher_ctx = NULL;
10903 ssh->sccipher = NULL;
10904 ssh->sc_cipher_ctx = NULL;
10906 ssh->cs_mac_ctx = NULL;
10908 ssh->sc_mac_ctx = NULL;
10909 ssh->cscomp = NULL;
10910 ssh->cs_comp_ctx = NULL;
10911 ssh->sccomp = NULL;
10912 ssh->sc_comp_ctx = NULL;
10914 ssh->kex_ctx = NULL;
10915 ssh->hostkey = NULL;
10916 ssh->hostkey_str = NULL;
10917 ssh->exitcode = -1;
10918 ssh->close_expected = FALSE;
10919 ssh->clean_exit = FALSE;
10920 ssh->state = SSH_STATE_PREPACKET;
10921 ssh->size_needed = FALSE;
10922 ssh->eof_needed = FALSE;
10924 ssh->logctx = NULL;
10925 ssh->deferred_send_data = NULL;
10926 ssh->deferred_len = 0;
10927 ssh->deferred_size = 0;
10928 ssh->fallback_cmd = 0;
10929 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
10930 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
10931 ssh->x11disp = NULL;
10932 ssh->x11auth = NULL;
10933 ssh->x11authtree = newtree234(x11_authcmp);
10934 ssh->v1_compressing = FALSE;
10935 ssh->v2_outgoing_sequence = 0;
10936 ssh->ssh1_rdpkt_crstate = 0;
10937 ssh->ssh2_rdpkt_crstate = 0;
10938 ssh->ssh2_bare_rdpkt_crstate = 0;
10939 ssh->ssh_gotdata_crstate = 0;
10940 ssh->do_ssh1_connection_crstate = 0;
10941 ssh->do_ssh_init_state = NULL;
10942 ssh->do_ssh_connection_init_state = NULL;
10943 ssh->do_ssh1_login_state = NULL;
10944 ssh->do_ssh2_transport_state = NULL;
10945 ssh->do_ssh2_authconn_state = NULL;
10948 ssh->mainchan = NULL;
10949 ssh->throttled_all = 0;
10950 ssh->v1_stdout_throttling = 0;
10952 ssh->queuelen = ssh->queuesize = 0;
10953 ssh->queueing = FALSE;
10954 ssh->qhead = ssh->qtail = NULL;
10955 ssh->deferred_rekey_reason = NULL;
10956 bufchain_init(&ssh->queued_incoming_data);
10957 ssh->frozen = FALSE;
10958 ssh->username = NULL;
10959 ssh->sent_console_eof = FALSE;
10960 ssh->got_pty = FALSE;
10961 ssh->bare_connection = FALSE;
10962 ssh->X11_fwd_enabled = FALSE;
10963 ssh->connshare = NULL;
10964 ssh->attempting_connshare = FALSE;
10966 *backend_handle = ssh;
10969 if (crypto_startup() == 0)
10970 return "Microsoft high encryption pack not installed!";
10973 ssh->frontend = frontend_handle;
10974 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
10975 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
10977 ssh->channels = NULL;
10978 ssh->rportfwds = NULL;
10979 ssh->portfwds = NULL;
10984 ssh->conn_throttle_count = 0;
10985 ssh->overall_bufsize = 0;
10986 ssh->fallback_cmd = 0;
10988 ssh->protocol = NULL;
10990 ssh->protocol_initial_phase_done = FALSE;
10992 ssh->pinger = NULL;
10994 ssh->incoming_data_size = ssh->outgoing_data_size =
10995 ssh->deferred_data_size = 0L;
10996 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10997 CONF_ssh_rekey_data));
10998 ssh->kex_in_progress = FALSE;
11001 ssh->gsslibs = NULL;
11004 random_ref(); /* do this now - may be needed by sharing setup code */
11006 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
11015 static void ssh_free(void *handle)
11017 Ssh ssh = (Ssh) handle;
11018 struct ssh_channel *c;
11019 struct ssh_rportfwd *pf;
11020 struct X11FakeAuth *auth;
11022 if (ssh->v1_cipher_ctx)
11023 ssh->cipher->free_context(ssh->v1_cipher_ctx);
11024 if (ssh->cs_cipher_ctx)
11025 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
11026 if (ssh->sc_cipher_ctx)
11027 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
11028 if (ssh->cs_mac_ctx)
11029 ssh->csmac->free_context(ssh->cs_mac_ctx);
11030 if (ssh->sc_mac_ctx)
11031 ssh->scmac->free_context(ssh->sc_mac_ctx);
11032 if (ssh->cs_comp_ctx) {
11034 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
11036 zlib_compress_cleanup(ssh->cs_comp_ctx);
11038 if (ssh->sc_comp_ctx) {
11040 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
11042 zlib_decompress_cleanup(ssh->sc_comp_ctx);
11045 dh_cleanup(ssh->kex_ctx);
11046 sfree(ssh->savedhost);
11048 while (ssh->queuelen-- > 0)
11049 ssh_free_packet(ssh->queue[ssh->queuelen]);
11052 while (ssh->qhead) {
11053 struct queued_handler *qh = ssh->qhead;
11054 ssh->qhead = qh->next;
11057 ssh->qhead = ssh->qtail = NULL;
11059 if (ssh->channels) {
11060 while ((c = delpos234(ssh->channels, 0)) != NULL) {
11063 if (c->u.x11.xconn != NULL)
11064 x11_close(c->u.x11.xconn);
11066 case CHAN_SOCKDATA:
11067 case CHAN_SOCKDATA_DORMANT:
11068 if (c->u.pfd.pf != NULL)
11069 pfd_close(c->u.pfd.pf);
11072 if (ssh->version == 2) {
11073 struct outstanding_channel_request *ocr, *nocr;
11074 ocr = c->v.v2.chanreq_head;
11076 ocr->handler(c, NULL, ocr->ctx);
11081 bufchain_clear(&c->v.v2.outbuffer);
11085 freetree234(ssh->channels);
11086 ssh->channels = NULL;
11089 if (ssh->connshare)
11090 sharestate_free(ssh->connshare);
11092 if (ssh->rportfwds) {
11093 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
11095 freetree234(ssh->rportfwds);
11096 ssh->rportfwds = NULL;
11098 sfree(ssh->deferred_send_data);
11100 x11_free_display(ssh->x11disp);
11101 while ((auth = delpos234(ssh->x11authtree, 0)) != NULL)
11102 x11_free_fake_auth(auth);
11103 freetree234(ssh->x11authtree);
11104 sfree(ssh->do_ssh_init_state);
11105 sfree(ssh->do_ssh1_login_state);
11106 sfree(ssh->do_ssh2_transport_state);
11107 sfree(ssh->do_ssh2_authconn_state);
11110 sfree(ssh->fullhostname);
11111 sfree(ssh->hostkey_str);
11112 if (ssh->crcda_ctx) {
11113 crcda_free_context(ssh->crcda_ctx);
11114 ssh->crcda_ctx = NULL;
11117 ssh_do_close(ssh, TRUE);
11118 expire_timer_context(ssh);
11120 pinger_free(ssh->pinger);
11121 bufchain_clear(&ssh->queued_incoming_data);
11122 sfree(ssh->username);
11123 conf_free(ssh->conf);
11126 ssh_gss_cleanup(ssh->gsslibs);
11134 * Reconfigure the SSH backend.
11136 static void ssh_reconfig(void *handle, Conf *conf)
11138 Ssh ssh = (Ssh) handle;
11139 const char *rekeying = NULL;
11140 int rekey_mandatory = FALSE;
11141 unsigned long old_max_data_size;
11144 pinger_reconfig(ssh->pinger, ssh->conf, conf);
11146 ssh_setup_portfwd(ssh, conf);
11148 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
11149 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
11151 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
11152 unsigned long now = GETTICKCOUNT();
11154 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
11155 rekeying = "timeout shortened";
11157 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
11161 old_max_data_size = ssh->max_data_size;
11162 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
11163 CONF_ssh_rekey_data));
11164 if (old_max_data_size != ssh->max_data_size &&
11165 ssh->max_data_size != 0) {
11166 if (ssh->outgoing_data_size > ssh->max_data_size ||
11167 ssh->incoming_data_size > ssh->max_data_size)
11168 rekeying = "data limit lowered";
11171 if (conf_get_int(ssh->conf, CONF_compression) !=
11172 conf_get_int(conf, CONF_compression)) {
11173 rekeying = "compression setting changed";
11174 rekey_mandatory = TRUE;
11177 for (i = 0; i < CIPHER_MAX; i++)
11178 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
11179 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
11180 rekeying = "cipher settings changed";
11181 rekey_mandatory = TRUE;
11183 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
11184 conf_get_int(conf, CONF_ssh2_des_cbc)) {
11185 rekeying = "cipher settings changed";
11186 rekey_mandatory = TRUE;
11189 conf_free(ssh->conf);
11190 ssh->conf = conf_copy(conf);
11191 ssh_cache_conf_values(ssh);
11193 if (!ssh->bare_connection && rekeying) {
11194 if (!ssh->kex_in_progress) {
11195 do_ssh2_transport(ssh, rekeying, -1, NULL);
11196 } else if (rekey_mandatory) {
11197 ssh->deferred_rekey_reason = rekeying;
11203 * Called to send data down the SSH connection.
11205 static int ssh_send(void *handle, const char *buf, int len)
11207 Ssh ssh = (Ssh) handle;
11209 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
11212 ssh->protocol(ssh, (const unsigned char *)buf, len, 0);
11214 return ssh_sendbuffer(ssh);
11218 * Called to query the current amount of buffered stdin data.
11220 static int ssh_sendbuffer(void *handle)
11222 Ssh ssh = (Ssh) handle;
11223 int override_value;
11225 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
11229 * If the SSH socket itself has backed up, add the total backup
11230 * size on that to any individual buffer on the stdin channel.
11232 override_value = 0;
11233 if (ssh->throttled_all)
11234 override_value = ssh->overall_bufsize;
11236 if (ssh->version == 1) {
11237 return override_value;
11238 } else if (ssh->version == 2) {
11239 if (!ssh->mainchan)
11240 return override_value;
11242 return (override_value +
11243 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
11250 * Called to set the size of the window from SSH's POV.
11252 static void ssh_size(void *handle, int width, int height)
11254 Ssh ssh = (Ssh) handle;
11255 struct Packet *pktout;
11257 ssh->term_width = width;
11258 ssh->term_height = height;
11260 switch (ssh->state) {
11261 case SSH_STATE_BEFORE_SIZE:
11262 case SSH_STATE_PREPACKET:
11263 case SSH_STATE_CLOSED:
11264 break; /* do nothing */
11265 case SSH_STATE_INTERMED:
11266 ssh->size_needed = TRUE; /* buffer for later */
11268 case SSH_STATE_SESSION:
11269 if (!conf_get_int(ssh->conf, CONF_nopty)) {
11270 if (ssh->version == 1) {
11271 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
11272 PKT_INT, ssh->term_height,
11273 PKT_INT, ssh->term_width,
11274 PKT_INT, 0, PKT_INT, 0, PKT_END);
11275 } else if (ssh->mainchan) {
11276 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
11278 ssh2_pkt_adduint32(pktout, ssh->term_width);
11279 ssh2_pkt_adduint32(pktout, ssh->term_height);
11280 ssh2_pkt_adduint32(pktout, 0);
11281 ssh2_pkt_adduint32(pktout, 0);
11282 ssh2_pkt_send(ssh, pktout);
11290 * Return a list of the special codes that make sense in this
11293 static const struct telnet_special *ssh_get_specials(void *handle)
11295 static const struct telnet_special ssh1_ignore_special[] = {
11296 {"IGNORE message", TS_NOP}
11298 static const struct telnet_special ssh2_ignore_special[] = {
11299 {"IGNORE message", TS_NOP},
11301 static const struct telnet_special ssh2_rekey_special[] = {
11302 {"Repeat key exchange", TS_REKEY},
11304 static const struct telnet_special ssh2_session_specials[] = {
11307 /* These are the signal names defined by RFC 4254.
11308 * They include all the ISO C signals, but are a subset of the POSIX
11309 * required signals. */
11310 {"SIGINT (Interrupt)", TS_SIGINT},
11311 {"SIGTERM (Terminate)", TS_SIGTERM},
11312 {"SIGKILL (Kill)", TS_SIGKILL},
11313 {"SIGQUIT (Quit)", TS_SIGQUIT},
11314 {"SIGHUP (Hangup)", TS_SIGHUP},
11315 {"More signals", TS_SUBMENU},
11316 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
11317 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
11318 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
11319 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
11320 {NULL, TS_EXITMENU}
11322 static const struct telnet_special specials_end[] = {
11323 {NULL, TS_EXITMENU}
11325 /* XXX review this length for any changes: */
11326 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
11327 lenof(ssh2_rekey_special) +
11328 lenof(ssh2_session_specials) +
11329 lenof(specials_end)];
11330 Ssh ssh = (Ssh) handle;
11332 #define ADD_SPECIALS(name) \
11334 assert((i + lenof(name)) <= lenof(ssh_specials)); \
11335 memcpy(&ssh_specials[i], name, sizeof name); \
11336 i += lenof(name); \
11339 if (ssh->version == 1) {
11340 /* Don't bother offering IGNORE if we've decided the remote
11341 * won't cope with it, since we wouldn't bother sending it if
11343 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11344 ADD_SPECIALS(ssh1_ignore_special);
11345 } else if (ssh->version == 2) {
11346 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
11347 ADD_SPECIALS(ssh2_ignore_special);
11348 if (!(ssh->remote_bugs & BUG_SSH2_REKEY) && !ssh->bare_connection)
11349 ADD_SPECIALS(ssh2_rekey_special);
11351 ADD_SPECIALS(ssh2_session_specials);
11352 } /* else we're not ready yet */
11355 ADD_SPECIALS(specials_end);
11356 return ssh_specials;
11360 #undef ADD_SPECIALS
11364 * Send special codes. TS_EOF is useful for `plink', so you
11365 * can send an EOF and collect resulting output (e.g. `plink
11368 static void ssh_special(void *handle, Telnet_Special code)
11370 Ssh ssh = (Ssh) handle;
11371 struct Packet *pktout;
11373 if (code == TS_EOF) {
11374 if (ssh->state != SSH_STATE_SESSION) {
11376 * Buffer the EOF in case we are pre-SESSION, so we can
11377 * send it as soon as we reach SESSION.
11379 if (code == TS_EOF)
11380 ssh->eof_needed = TRUE;
11383 if (ssh->version == 1) {
11384 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
11385 } else if (ssh->mainchan) {
11386 sshfwd_write_eof(ssh->mainchan);
11387 ssh->send_ok = 0; /* now stop trying to read from stdin */
11389 logevent("Sent EOF message");
11390 } else if (code == TS_PING || code == TS_NOP) {
11391 if (ssh->state == SSH_STATE_CLOSED
11392 || ssh->state == SSH_STATE_PREPACKET) return;
11393 if (ssh->version == 1) {
11394 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11395 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
11397 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
11398 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
11399 ssh2_pkt_addstring_start(pktout);
11400 ssh2_pkt_send_noqueue(ssh, pktout);
11403 } else if (code == TS_REKEY) {
11404 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11405 ssh->version == 2) {
11406 do_ssh2_transport(ssh, "at user request", -1, NULL);
11408 } else if (code == TS_BRK) {
11409 if (ssh->state == SSH_STATE_CLOSED
11410 || ssh->state == SSH_STATE_PREPACKET) return;
11411 if (ssh->version == 1) {
11412 logevent("Unable to send BREAK signal in SSH-1");
11413 } else if (ssh->mainchan) {
11414 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
11415 ssh2_pkt_adduint32(pktout, 0); /* default break length */
11416 ssh2_pkt_send(ssh, pktout);
11419 /* Is is a POSIX signal? */
11420 const char *signame = NULL;
11421 if (code == TS_SIGABRT) signame = "ABRT";
11422 if (code == TS_SIGALRM) signame = "ALRM";
11423 if (code == TS_SIGFPE) signame = "FPE";
11424 if (code == TS_SIGHUP) signame = "HUP";
11425 if (code == TS_SIGILL) signame = "ILL";
11426 if (code == TS_SIGINT) signame = "INT";
11427 if (code == TS_SIGKILL) signame = "KILL";
11428 if (code == TS_SIGPIPE) signame = "PIPE";
11429 if (code == TS_SIGQUIT) signame = "QUIT";
11430 if (code == TS_SIGSEGV) signame = "SEGV";
11431 if (code == TS_SIGTERM) signame = "TERM";
11432 if (code == TS_SIGUSR1) signame = "USR1";
11433 if (code == TS_SIGUSR2) signame = "USR2";
11434 /* The SSH-2 protocol does in principle support arbitrary named
11435 * signals, including signame@domain, but we don't support those. */
11437 /* It's a signal. */
11438 if (ssh->version == 2 && ssh->mainchan) {
11439 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
11440 ssh2_pkt_addstring(pktout, signame);
11441 ssh2_pkt_send(ssh, pktout);
11442 logeventf(ssh, "Sent signal SIG%s", signame);
11445 /* Never heard of it. Do nothing */
11450 void *new_sock_channel(void *handle, struct PortForwarding *pf)
11452 Ssh ssh = (Ssh) handle;
11453 struct ssh_channel *c;
11454 c = snew(struct ssh_channel);
11457 ssh2_channel_init(c);
11458 c->halfopen = TRUE;
11459 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
11461 add234(ssh->channels, c);
11465 unsigned ssh_alloc_sharing_channel(Ssh ssh, void *sharing_ctx)
11467 struct ssh_channel *c;
11468 c = snew(struct ssh_channel);
11471 ssh2_channel_init(c);
11472 c->type = CHAN_SHARING;
11473 c->u.sharing.ctx = sharing_ctx;
11474 add234(ssh->channels, c);
11478 void ssh_delete_sharing_channel(Ssh ssh, unsigned localid)
11480 struct ssh_channel *c;
11482 c = find234(ssh->channels, &localid, ssh_channelfind);
11484 ssh_channel_destroy(c);
11487 void ssh_send_packet_from_downstream(Ssh ssh, unsigned id, int type,
11488 const void *data, int datalen,
11489 const char *additional_log_text)
11491 struct Packet *pkt;
11493 pkt = ssh2_pkt_init(type);
11494 pkt->downstream_id = id;
11495 pkt->additional_log_text = additional_log_text;
11496 ssh2_pkt_adddata(pkt, data, datalen);
11497 ssh2_pkt_send(ssh, pkt);
11501 * This is called when stdout/stderr (the entity to which
11502 * from_backend sends data) manages to clear some backlog.
11504 static void ssh_unthrottle(void *handle, int bufsize)
11506 Ssh ssh = (Ssh) handle;
11509 if (ssh->version == 1) {
11510 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
11511 ssh->v1_stdout_throttling = 0;
11512 ssh_throttle_conn(ssh, -1);
11515 if (ssh->mainchan) {
11516 ssh2_set_window(ssh->mainchan,
11517 bufsize < ssh->mainchan->v.v2.locmaxwin ?
11518 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
11519 if (ssh_is_simple(ssh))
11522 buflimit = ssh->mainchan->v.v2.locmaxwin;
11523 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
11524 ssh->mainchan->throttling_conn = 0;
11525 ssh_throttle_conn(ssh, -1);
11531 * Now process any SSH connection data that was stashed in our
11532 * queue while we were frozen.
11534 ssh_process_queued_incoming_data(ssh);
11537 void ssh_send_port_open(void *channel, const char *hostname, int port,
11540 struct ssh_channel *c = (struct ssh_channel *)channel;
11542 struct Packet *pktout;
11544 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
11546 if (ssh->version == 1) {
11547 send_packet(ssh, SSH1_MSG_PORT_OPEN,
11548 PKT_INT, c->localid,
11551 /* PKT_STR, <org:orgport>, */
11554 pktout = ssh2_chanopen_init(c, "direct-tcpip");
11556 char *trimmed_host = host_strduptrim(hostname);
11557 ssh2_pkt_addstring(pktout, trimmed_host);
11558 sfree(trimmed_host);
11560 ssh2_pkt_adduint32(pktout, port);
11562 * We make up values for the originator data; partly it's
11563 * too much hassle to keep track, and partly I'm not
11564 * convinced the server should be told details like that
11565 * about my local network configuration.
11566 * The "originator IP address" is syntactically a numeric
11567 * IP address, and some servers (e.g., Tectia) get upset
11568 * if it doesn't match this syntax.
11570 ssh2_pkt_addstring(pktout, "0.0.0.0");
11571 ssh2_pkt_adduint32(pktout, 0);
11572 ssh2_pkt_send(ssh, pktout);
11576 static int ssh_connected(void *handle)
11578 Ssh ssh = (Ssh) handle;
11579 return ssh->s != NULL;
11582 static int ssh_sendok(void *handle)
11584 Ssh ssh = (Ssh) handle;
11585 return ssh->send_ok;
11588 static int ssh_ldisc(void *handle, int option)
11590 Ssh ssh = (Ssh) handle;
11591 if (option == LD_ECHO)
11592 return ssh->echoing;
11593 if (option == LD_EDIT)
11594 return ssh->editing;
11598 static void ssh_provide_ldisc(void *handle, void *ldisc)
11600 Ssh ssh = (Ssh) handle;
11601 ssh->ldisc = ldisc;
11604 static void ssh_provide_logctx(void *handle, void *logctx)
11606 Ssh ssh = (Ssh) handle;
11607 ssh->logctx = logctx;
11610 static int ssh_return_exitcode(void *handle)
11612 Ssh ssh = (Ssh) handle;
11613 if (ssh->s != NULL)
11616 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
11620 * cfg_info for SSH is the protocol running in this session.
11621 * (1 or 2 for the full SSH-1 or SSH-2 protocol; -1 for the bare
11622 * SSH-2 connection protocol, i.e. a downstream; 0 for not-decided-yet.)
11624 static int ssh_cfg_info(void *handle)
11626 Ssh ssh = (Ssh) handle;
11627 if (ssh->version == 0)
11628 return 0; /* don't know yet */
11629 else if (ssh->bare_connection)
11632 return ssh->version;
11636 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
11637 * that fails. This variable is the means by which scp.c can reach
11638 * into the SSH code and find out which one it got.
11640 extern int ssh_fallback_cmd(void *handle)
11642 Ssh ssh = (Ssh) handle;
11643 return ssh->fallback_cmd;
11646 Backend ssh_backend = {
11656 ssh_return_exitcode,
11660 ssh_provide_logctx,
11663 ssh_test_for_upstream,