28 * Packet type contexts, so that ssh2_pkt_type can correctly decode
29 * the ambiguous type numbers back into the correct type strings.
39 SSH2_PKTCTX_PUBLICKEY,
45 static const char *const ssh2_disconnect_reasons[] = {
47 "host not allowed to connect",
49 "key exchange failed",
50 "host authentication failed",
53 "service not available",
54 "protocol version not supported",
55 "host key not verifiable",
58 "too many connections",
59 "auth cancelled by user",
60 "no more auth methods available",
65 * Various remote-bug flags.
67 #define BUG_CHOKES_ON_SSH1_IGNORE 1
68 #define BUG_SSH2_HMAC 2
69 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
70 #define BUG_CHOKES_ON_RSA 8
71 #define BUG_SSH2_RSA_PADDING 16
72 #define BUG_SSH2_DERIVEKEY 32
73 #define BUG_SSH2_REKEY 64
74 #define BUG_SSH2_PK_SESSIONID 128
75 #define BUG_SSH2_MAXPKT 256
76 #define BUG_CHOKES_ON_SSH2_IGNORE 512
77 #define BUG_CHOKES_ON_WINADJ 1024
80 * Codes for terminal modes.
81 * Most of these are the same in SSH-1 and SSH-2.
82 * This list is derived from RFC 4254 and
86 const char* const mode;
88 enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
90 /* "V" prefix discarded for special characters relative to SSH specs */
91 { "INTR", 1, TTY_OP_CHAR },
92 { "QUIT", 2, TTY_OP_CHAR },
93 { "ERASE", 3, TTY_OP_CHAR },
94 { "KILL", 4, TTY_OP_CHAR },
95 { "EOF", 5, TTY_OP_CHAR },
96 { "EOL", 6, TTY_OP_CHAR },
97 { "EOL2", 7, TTY_OP_CHAR },
98 { "START", 8, TTY_OP_CHAR },
99 { "STOP", 9, TTY_OP_CHAR },
100 { "SUSP", 10, TTY_OP_CHAR },
101 { "DSUSP", 11, TTY_OP_CHAR },
102 { "REPRINT", 12, TTY_OP_CHAR },
103 { "WERASE", 13, TTY_OP_CHAR },
104 { "LNEXT", 14, TTY_OP_CHAR },
105 { "FLUSH", 15, TTY_OP_CHAR },
106 { "SWTCH", 16, TTY_OP_CHAR },
107 { "STATUS", 17, TTY_OP_CHAR },
108 { "DISCARD", 18, TTY_OP_CHAR },
109 { "IGNPAR", 30, TTY_OP_BOOL },
110 { "PARMRK", 31, TTY_OP_BOOL },
111 { "INPCK", 32, TTY_OP_BOOL },
112 { "ISTRIP", 33, TTY_OP_BOOL },
113 { "INLCR", 34, TTY_OP_BOOL },
114 { "IGNCR", 35, TTY_OP_BOOL },
115 { "ICRNL", 36, TTY_OP_BOOL },
116 { "IUCLC", 37, TTY_OP_BOOL },
117 { "IXON", 38, TTY_OP_BOOL },
118 { "IXANY", 39, TTY_OP_BOOL },
119 { "IXOFF", 40, TTY_OP_BOOL },
120 { "IMAXBEL", 41, TTY_OP_BOOL },
121 { "ISIG", 50, TTY_OP_BOOL },
122 { "ICANON", 51, TTY_OP_BOOL },
123 { "XCASE", 52, TTY_OP_BOOL },
124 { "ECHO", 53, TTY_OP_BOOL },
125 { "ECHOE", 54, TTY_OP_BOOL },
126 { "ECHOK", 55, TTY_OP_BOOL },
127 { "ECHONL", 56, TTY_OP_BOOL },
128 { "NOFLSH", 57, TTY_OP_BOOL },
129 { "TOSTOP", 58, TTY_OP_BOOL },
130 { "IEXTEN", 59, TTY_OP_BOOL },
131 { "ECHOCTL", 60, TTY_OP_BOOL },
132 { "ECHOKE", 61, TTY_OP_BOOL },
133 { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */
134 { "OPOST", 70, TTY_OP_BOOL },
135 { "OLCUC", 71, TTY_OP_BOOL },
136 { "ONLCR", 72, TTY_OP_BOOL },
137 { "OCRNL", 73, TTY_OP_BOOL },
138 { "ONOCR", 74, TTY_OP_BOOL },
139 { "ONLRET", 75, TTY_OP_BOOL },
140 { "CS7", 90, TTY_OP_BOOL },
141 { "CS8", 91, TTY_OP_BOOL },
142 { "PARENB", 92, TTY_OP_BOOL },
143 { "PARODD", 93, TTY_OP_BOOL }
146 /* Miscellaneous other tty-related constants. */
147 #define SSH_TTY_OP_END 0
148 /* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */
149 #define SSH1_TTY_OP_ISPEED 192
150 #define SSH1_TTY_OP_OSPEED 193
151 #define SSH2_TTY_OP_ISPEED 128
152 #define SSH2_TTY_OP_OSPEED 129
154 /* Helper functions for parsing tty-related config. */
155 static unsigned int ssh_tty_parse_specchar(char *s)
160 ret = ctrlparse(s, &next);
161 if (!next) ret = s[0];
163 ret = 255; /* special value meaning "don't set" */
167 static unsigned int ssh_tty_parse_boolean(char *s)
169 if (stricmp(s, "yes") == 0 ||
170 stricmp(s, "on") == 0 ||
171 stricmp(s, "true") == 0 ||
172 stricmp(s, "+") == 0)
174 else if (stricmp(s, "no") == 0 ||
175 stricmp(s, "off") == 0 ||
176 stricmp(s, "false") == 0 ||
177 stricmp(s, "-") == 0)
178 return 0; /* false */
180 return (atoi(s) != 0);
183 #define translate(x) if (type == x) return #x
184 #define translatek(x,ctx) if (type == x && (pkt_kctx == ctx)) return #x
185 #define translatea(x,ctx) if (type == x && (pkt_actx == ctx)) return #x
186 static char *ssh1_pkt_type(int type)
188 translate(SSH1_MSG_DISCONNECT);
189 translate(SSH1_SMSG_PUBLIC_KEY);
190 translate(SSH1_CMSG_SESSION_KEY);
191 translate(SSH1_CMSG_USER);
192 translate(SSH1_CMSG_AUTH_RSA);
193 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
194 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
195 translate(SSH1_CMSG_AUTH_PASSWORD);
196 translate(SSH1_CMSG_REQUEST_PTY);
197 translate(SSH1_CMSG_WINDOW_SIZE);
198 translate(SSH1_CMSG_EXEC_SHELL);
199 translate(SSH1_CMSG_EXEC_CMD);
200 translate(SSH1_SMSG_SUCCESS);
201 translate(SSH1_SMSG_FAILURE);
202 translate(SSH1_CMSG_STDIN_DATA);
203 translate(SSH1_SMSG_STDOUT_DATA);
204 translate(SSH1_SMSG_STDERR_DATA);
205 translate(SSH1_CMSG_EOF);
206 translate(SSH1_SMSG_EXIT_STATUS);
207 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
208 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
209 translate(SSH1_MSG_CHANNEL_DATA);
210 translate(SSH1_MSG_CHANNEL_CLOSE);
211 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
212 translate(SSH1_SMSG_X11_OPEN);
213 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
214 translate(SSH1_MSG_PORT_OPEN);
215 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
216 translate(SSH1_SMSG_AGENT_OPEN);
217 translate(SSH1_MSG_IGNORE);
218 translate(SSH1_CMSG_EXIT_CONFIRMATION);
219 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
220 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
221 translate(SSH1_MSG_DEBUG);
222 translate(SSH1_CMSG_REQUEST_COMPRESSION);
223 translate(SSH1_CMSG_AUTH_TIS);
224 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
225 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
226 translate(SSH1_CMSG_AUTH_CCARD);
227 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
228 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
231 static char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx, int type)
233 translatea(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,SSH2_PKTCTX_GSSAPI);
234 translatea(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,SSH2_PKTCTX_GSSAPI);
235 translatea(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,SSH2_PKTCTX_GSSAPI);
236 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERROR,SSH2_PKTCTX_GSSAPI);
237 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK,SSH2_PKTCTX_GSSAPI);
238 translatea(SSH2_MSG_USERAUTH_GSSAPI_MIC, SSH2_PKTCTX_GSSAPI);
239 translate(SSH2_MSG_DISCONNECT);
240 translate(SSH2_MSG_IGNORE);
241 translate(SSH2_MSG_UNIMPLEMENTED);
242 translate(SSH2_MSG_DEBUG);
243 translate(SSH2_MSG_SERVICE_REQUEST);
244 translate(SSH2_MSG_SERVICE_ACCEPT);
245 translate(SSH2_MSG_KEXINIT);
246 translate(SSH2_MSG_NEWKEYS);
247 translatek(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
248 translatek(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
249 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
250 translatek(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
251 translatek(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
252 translatek(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
253 translatek(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX);
254 translatek(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX);
255 translatek(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX);
256 translate(SSH2_MSG_USERAUTH_REQUEST);
257 translate(SSH2_MSG_USERAUTH_FAILURE);
258 translate(SSH2_MSG_USERAUTH_SUCCESS);
259 translate(SSH2_MSG_USERAUTH_BANNER);
260 translatea(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
261 translatea(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
262 translatea(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
263 translatea(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
264 translate(SSH2_MSG_GLOBAL_REQUEST);
265 translate(SSH2_MSG_REQUEST_SUCCESS);
266 translate(SSH2_MSG_REQUEST_FAILURE);
267 translate(SSH2_MSG_CHANNEL_OPEN);
268 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
269 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
270 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
271 translate(SSH2_MSG_CHANNEL_DATA);
272 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
273 translate(SSH2_MSG_CHANNEL_EOF);
274 translate(SSH2_MSG_CHANNEL_CLOSE);
275 translate(SSH2_MSG_CHANNEL_REQUEST);
276 translate(SSH2_MSG_CHANNEL_SUCCESS);
277 translate(SSH2_MSG_CHANNEL_FAILURE);
283 /* Enumeration values for fields in SSH-1 packets */
285 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
289 * Coroutine mechanics for the sillier bits of the code. If these
290 * macros look impenetrable to you, you might find it helpful to
293 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
295 * which explains the theory behind these macros.
297 * In particular, if you are getting `case expression not constant'
298 * errors when building with MS Visual Studio, this is because MS's
299 * Edit and Continue debugging feature causes their compiler to
300 * violate ANSI C. To disable Edit and Continue debugging:
302 * - right-click ssh.c in the FileView
304 * - select the C/C++ tab and the General category
305 * - under `Debug info:', select anything _other_ than `Program
306 * Database for Edit and Continue'.
308 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
309 #define crBeginState crBegin(s->crLine)
310 #define crStateP(t, v) \
312 if (!(v)) { s = (v) = snew(struct t); s->crLine = 0; } \
314 #define crState(t) crStateP(t, ssh->t)
315 #define crFinish(z) } *crLine = 0; return (z); }
316 #define crFinishV } *crLine = 0; return; }
317 #define crFinishFree(z) } sfree(s); return (z); }
318 #define crFinishFreeV } sfree(s); return; }
319 #define crReturn(z) \
321 *crLine =__LINE__; return (z); case __LINE__:;\
325 *crLine=__LINE__; return; case __LINE__:;\
327 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
328 #define crStopV do{ *crLine = 0; return; }while(0)
329 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
330 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
334 static struct Packet *ssh1_pkt_init(int pkt_type);
335 static struct Packet *ssh2_pkt_init(int pkt_type);
336 static void ssh_pkt_ensure(struct Packet *, int length);
337 static void ssh_pkt_adddata(struct Packet *, const void *data, int len);
338 static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
339 static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
340 static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
341 static void ssh_pkt_addstring_start(struct Packet *);
342 static void ssh_pkt_addstring_str(struct Packet *, const char *data);
343 static void ssh_pkt_addstring_data(struct Packet *, const char *data, int len);
344 static void ssh_pkt_addstring(struct Packet *, const char *data);
345 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
346 static void ssh1_pkt_addmp(struct Packet *, Bignum b);
347 static void ssh2_pkt_addmp(struct Packet *, Bignum b);
348 static int ssh2_pkt_construct(Ssh, struct Packet *);
349 static void ssh2_pkt_send(Ssh, struct Packet *);
350 static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
351 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
352 struct Packet *pktin);
353 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
354 struct Packet *pktin);
355 static void ssh2_channel_check_close(struct ssh_channel *c);
356 static void ssh_channel_destroy(struct ssh_channel *c);
359 * Buffer management constants. There are several of these for
360 * various different purposes:
362 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
363 * on a local data stream before we throttle the whole SSH
364 * connection (in SSH-1 only). Throttling the whole connection is
365 * pretty drastic so we set this high in the hope it won't
368 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
369 * on the SSH connection itself before we defensively throttle
370 * _all_ local data streams. This is pretty drastic too (though
371 * thankfully unlikely in SSH-2 since the window mechanism should
372 * ensure that the server never has any need to throttle its end
373 * of the connection), so we set this high as well.
375 * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
378 * - OUR_V2_BIGWIN is the window size we advertise for the only
379 * channel in a simple connection. It must be <= INT_MAX.
381 * - OUR_V2_MAXPKT is the official "maximum packet size" we send
382 * to the remote side. This actually has nothing to do with the
383 * size of the _packet_, but is instead a limit on the amount
384 * of data we're willing to receive in a single SSH2 channel
387 * - OUR_V2_PACKETLIMIT is actually the maximum size of SSH
388 * _packet_ we're prepared to cope with. It must be a multiple
389 * of the cipher block size, and must be at least 35000.
392 #define SSH1_BUFFER_LIMIT 32768
393 #define SSH_MAX_BACKLOG 32768
394 #define OUR_V2_WINSIZE 16384
395 #define OUR_V2_BIGWIN 0x7fffffff
396 #define OUR_V2_MAXPKT 0x4000UL
397 #define OUR_V2_PACKETLIMIT 0x9000UL
399 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
401 const static struct ssh_mac *macs[] = {
402 &ssh_hmac_sha256, &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
404 const static struct ssh_mac *buggymacs[] = {
405 &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
408 static void *ssh_comp_none_init(void)
412 static void ssh_comp_none_cleanup(void *handle)
415 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
416 unsigned char **outblock, int *outlen)
420 static int ssh_comp_none_disable(void *handle)
424 const static struct ssh_compress ssh_comp_none = {
426 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
427 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
428 ssh_comp_none_disable, NULL
430 extern const struct ssh_compress ssh_zlib;
431 const static struct ssh_compress *compressions[] = {
432 &ssh_zlib, &ssh_comp_none
435 enum { /* channel types */
440 CHAN_SOCKDATA_DORMANT, /* one the remote hasn't confirmed */
442 * CHAN_SHARING indicates a channel which is tracked here on
443 * behalf of a connection-sharing downstream. We do almost nothing
444 * with these channels ourselves: all messages relating to them
445 * get thrown straight to sshshare.c and passed on almost
446 * unmodified to downstream.
450 * CHAN_ZOMBIE is used to indicate a channel for which we've
451 * already destroyed the local data source: for instance, if a
452 * forwarded port experiences a socket error on the local side, we
453 * immediately destroy its local socket and turn the SSH channel
459 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
460 typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
461 typedef void (*cchandler_fn_t)(struct ssh_channel *, struct Packet *, void *);
464 * Each channel has a queue of outstanding CHANNEL_REQUESTS and their
467 struct outstanding_channel_request {
468 cchandler_fn_t handler;
470 struct outstanding_channel_request *next;
474 * 2-3-4 tree storing channels.
477 Ssh ssh; /* pointer back to main context */
478 unsigned remoteid, localid;
480 /* True if we opened this channel but server hasn't confirmed. */
483 * In SSH-1, this value contains four bits:
485 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
486 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
487 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
488 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
490 * A channel is completely finished with when all four bits are set.
492 * In SSH-2, the four bits mean:
494 * 1 We have sent SSH2_MSG_CHANNEL_EOF.
495 * 2 We have sent SSH2_MSG_CHANNEL_CLOSE.
496 * 4 We have received SSH2_MSG_CHANNEL_EOF.
497 * 8 We have received SSH2_MSG_CHANNEL_CLOSE.
499 * A channel is completely finished with when we have both sent
500 * and received CLOSE.
502 * The symbolic constants below use the SSH-2 terminology, which
503 * is a bit confusing in SSH-1, but we have to use _something_.
505 #define CLOSES_SENT_EOF 1
506 #define CLOSES_SENT_CLOSE 2
507 #define CLOSES_RCVD_EOF 4
508 #define CLOSES_RCVD_CLOSE 8
512 * This flag indicates that an EOF is pending on the outgoing side
513 * of the channel: that is, wherever we're getting the data for
514 * this channel has sent us some data followed by EOF. We can't
515 * actually send the EOF until we've finished sending the data, so
516 * we set this flag instead to remind us to do so once our buffer
522 * True if this channel is causing the underlying connection to be
527 struct ssh2_data_channel {
529 unsigned remwindow, remmaxpkt;
530 /* locwindow is signed so we can cope with excess data. */
531 int locwindow, locmaxwin;
533 * remlocwin is the amount of local window that we think
534 * the remote end had available to it after it sent the
535 * last data packet or window adjust ack.
539 * These store the list of channel requests that haven't
542 struct outstanding_channel_request *chanreq_head, *chanreq_tail;
543 enum { THROTTLED, UNTHROTTLING, UNTHROTTLED } throttle_state;
547 struct ssh_agent_channel {
548 unsigned char *message;
549 unsigned char msglen[4];
550 unsigned lensofar, totallen;
551 int outstanding_requests;
553 struct ssh_x11_channel {
554 struct X11Connection *xconn;
557 struct ssh_pfd_channel {
558 struct PortForwarding *pf;
560 struct ssh_sharing_channel {
567 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
568 * use this structure in different ways, reflecting SSH-2's
569 * altogether saner approach to port forwarding.
571 * In SSH-1, you arrange a remote forwarding by sending the server
572 * the remote port number, and the local destination host:port.
573 * When a connection comes in, the server sends you back that
574 * host:port pair, and you connect to it. This is a ready-made
575 * security hole if you're not on the ball: a malicious server
576 * could send you back _any_ host:port pair, so if you trustingly
577 * connect to the address it gives you then you've just opened the
578 * entire inside of your corporate network just by connecting
579 * through it to a dodgy SSH server. Hence, we must store a list of
580 * host:port pairs we _are_ trying to forward to, and reject a
581 * connection request from the server if it's not in the list.
583 * In SSH-2, each side of the connection minds its own business and
584 * doesn't send unnecessary information to the other. You arrange a
585 * remote forwarding by sending the server just the remote port
586 * number. When a connection comes in, the server tells you which
587 * of its ports was connected to; and _you_ have to remember what
588 * local host:port pair went with that port number.
590 * Hence, in SSH-1 this structure is indexed by destination
591 * host:port pair, whereas in SSH-2 it is indexed by source port.
593 struct ssh_portfwd; /* forward declaration */
595 struct ssh_rportfwd {
596 unsigned sport, dport;
600 struct ssh_portfwd *pfrec;
603 static void free_rportfwd(struct ssh_rportfwd *pf)
606 sfree(pf->sportdesc);
614 * Separately to the rportfwd tree (which is for looking up port
615 * open requests from the server), a tree of _these_ structures is
616 * used to keep track of all the currently open port forwardings,
617 * so that we can reconfigure in mid-session if the user requests
621 enum { DESTROY, KEEP, CREATE } status;
623 unsigned sport, dport;
626 struct ssh_rportfwd *remote;
628 struct PortListener *local;
630 #define free_portfwd(pf) ( \
631 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
632 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
635 long length; /* length of packet: see below */
636 long forcepad; /* SSH-2: force padding to at least this length */
637 int type; /* only used for incoming packets */
638 unsigned long sequence; /* SSH-2 incoming sequence number */
639 unsigned char *data; /* allocated storage */
640 unsigned char *body; /* offset of payload within `data' */
641 long savedpos; /* dual-purpose saved packet position: see below */
642 long maxlen; /* amount of storage allocated for `data' */
643 long encrypted_len; /* for SSH-2 total-size counting */
646 * A note on the 'length' and 'savedpos' fields above.
648 * Incoming packets are set up so that pkt->length is measured
649 * relative to pkt->body, which itself points to a few bytes after
650 * pkt->data (skipping some uninteresting header fields including
651 * the packet type code). The ssh_pkt_get* functions all expect
652 * this setup, and they also use pkt->savedpos to indicate how far
653 * through the packet being decoded they've got - and that, too,
654 * is an offset from pkt->body rather than pkt->data.
656 * During construction of an outgoing packet, however, pkt->length
657 * is measured relative to the base pointer pkt->data, and
658 * pkt->body is not really used for anything until the packet is
659 * ready for sending. In this mode, pkt->savedpos is reused as a
660 * temporary variable by the addstring functions, which write out
661 * a string length field and then keep going back and updating it
662 * as more data is appended to the subsequent string data field;
663 * pkt->savedpos stores the offset (again relative to pkt->data)
664 * of the start of the string data field.
667 /* Extra metadata used in SSH packet logging mode, allowing us to
668 * log in the packet header line that the packet came from a
669 * connection-sharing downstream and what if anything unusual was
670 * done to it. The additional_log_text field is expected to be a
671 * static string - it will not be freed. */
672 unsigned downstream_id;
673 const char *additional_log_text;
676 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
677 struct Packet *pktin);
678 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
679 struct Packet *pktin);
680 static void ssh2_bare_connection_protocol(Ssh ssh, void *vin, int inlen,
681 struct Packet *pktin);
682 static void ssh1_protocol_setup(Ssh ssh);
683 static void ssh2_protocol_setup(Ssh ssh);
684 static void ssh2_bare_connection_protocol_setup(Ssh ssh);
685 static void ssh_size(void *handle, int width, int height);
686 static void ssh_special(void *handle, Telnet_Special);
687 static int ssh2_try_send(struct ssh_channel *c);
688 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
689 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
690 static void ssh2_set_window(struct ssh_channel *c, int newwin);
691 static int ssh_sendbuffer(void *handle);
692 static int ssh_do_close(Ssh ssh, int notify_exit);
693 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
694 static int ssh2_pkt_getbool(struct Packet *pkt);
695 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
696 static void ssh2_timer(void *ctx, unsigned long now);
697 static void do_ssh2_transport(Ssh ssh, void *vin, int inlen,
698 struct Packet *pktin);
699 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin);
701 struct rdpkt1_state_tag {
702 long len, pad, biglen, to_read;
703 unsigned long realcrc, gotcrc;
707 struct Packet *pktin;
710 struct rdpkt2_state_tag {
711 long len, pad, payload, packetlen, maclen;
714 unsigned long incoming_sequence;
715 struct Packet *pktin;
718 struct rdpkt2_bare_state_tag {
722 unsigned long incoming_sequence;
723 struct Packet *pktin;
726 struct queued_handler;
727 struct queued_handler {
729 chandler_fn_t handler;
731 struct queued_handler *next;
735 const struct plug_function_table *fn;
736 /* the above field _must_ be first in the structure */
746 unsigned char session_key[32];
748 int v1_remote_protoflags;
749 int v1_local_protoflags;
750 int agentfwd_enabled;
753 const struct ssh_cipher *cipher;
756 const struct ssh2_cipher *cscipher, *sccipher;
757 void *cs_cipher_ctx, *sc_cipher_ctx;
758 const struct ssh_mac *csmac, *scmac;
759 void *cs_mac_ctx, *sc_mac_ctx;
760 const struct ssh_compress *cscomp, *sccomp;
761 void *cs_comp_ctx, *sc_comp_ctx;
762 const struct ssh_kex *kex;
763 const struct ssh_signkey *hostkey;
764 char *hostkey_str; /* string representation, for easy checking in rekeys */
765 unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN];
766 int v2_session_id_len;
770 int attempting_connshare;
776 int echoing, editing;
780 int ospeed, ispeed; /* temporaries */
781 int term_width, term_height;
783 tree234 *channels; /* indexed by local id */
784 struct ssh_channel *mainchan; /* primary session channel */
785 int ncmode; /* is primary channel direct-tcpip? */
790 tree234 *rportfwds, *portfwds;
794 SSH_STATE_BEFORE_SIZE,
800 int size_needed, eof_needed;
801 int sent_console_eof;
802 int got_pty; /* affects EOF behaviour on main channel */
804 struct Packet **queue;
805 int queuelen, queuesize;
807 unsigned char *deferred_send_data;
808 int deferred_len, deferred_size;
811 * Gross hack: pscp will try to start SFTP but fall back to
812 * scp1 if that fails. This variable is the means by which
813 * scp.c can reach into the SSH code and find out which one it
818 bufchain banner; /* accumulates banners during do_ssh2_authconn */
823 struct X11Display *x11disp;
824 struct X11FakeAuth *x11auth;
825 tree234 *x11authtree;
828 int conn_throttle_count;
831 int v1_stdout_throttling;
832 unsigned long v2_outgoing_sequence;
834 int ssh1_rdpkt_crstate;
835 int ssh2_rdpkt_crstate;
836 int ssh2_bare_rdpkt_crstate;
837 int ssh_gotdata_crstate;
838 int do_ssh1_connection_crstate;
840 void *do_ssh_init_state;
841 void *do_ssh1_login_state;
842 void *do_ssh2_transport_state;
843 void *do_ssh2_authconn_state;
844 void *do_ssh_connection_init_state;
846 struct rdpkt1_state_tag rdpkt1_state;
847 struct rdpkt2_state_tag rdpkt2_state;
848 struct rdpkt2_bare_state_tag rdpkt2_bare_state;
850 /* SSH-1 and SSH-2 use this for different things, but both use it */
851 int protocol_initial_phase_done;
853 void (*protocol) (Ssh ssh, void *vin, int inlen,
855 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
856 int (*do_ssh_init)(Ssh ssh, unsigned char c);
859 * We maintain our own copy of a Conf structure here. That way,
860 * when we're passed a new one for reconfiguration, we can check
861 * the differences and potentially reconfigure port forwardings
862 * etc in mid-session.
867 * Values cached out of conf so as to avoid the tree234 lookup
868 * cost every time they're used.
873 * Dynamically allocated username string created during SSH
874 * login. Stored in here rather than in the coroutine state so
875 * that it'll be reliably freed if we shut down the SSH session
876 * at some unexpected moment.
881 * Used to transfer data back from async callbacks.
883 void *agent_response;
884 int agent_response_len;
888 * The SSH connection can be set as `frozen', meaning we are
889 * not currently accepting incoming data from the network. This
890 * is slightly more serious than setting the _socket_ as
891 * frozen, because we may already have had data passed to us
892 * from the network which we need to delay processing until
893 * after the freeze is lifted, so we also need a bufchain to
897 bufchain queued_incoming_data;
900 * Dispatch table for packet types that we may have to deal
903 handler_fn_t packet_dispatch[256];
906 * Queues of one-off handler functions for success/failure
907 * indications from a request.
909 struct queued_handler *qhead, *qtail;
910 handler_fn_t q_saved_handler1, q_saved_handler2;
913 * This module deals with sending keepalives.
918 * Track incoming and outgoing data sizes and time, for
921 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
922 unsigned long max_data_size;
924 unsigned long next_rekey, last_rekey;
925 char *deferred_rekey_reason; /* points to STATIC string; don't free */
928 * Fully qualified host name, which we need if doing GSSAPI.
934 * GSSAPI libraries for this session.
936 struct ssh_gss_liblist *gsslibs;
940 #define logevent(s) logevent(ssh->frontend, s)
942 /* logevent, only printf-formatted. */
943 static void logeventf(Ssh ssh, const char *fmt, ...)
949 buf = dupvprintf(fmt, ap);
955 static void bomb_out(Ssh ssh, char *text)
957 ssh_do_close(ssh, FALSE);
959 connection_fatal(ssh->frontend, "%s", text);
963 #define bombout(msg) bomb_out(ssh, dupprintf msg)
965 /* Helper function for common bits of parsing ttymodes. */
966 static void parse_ttymodes(Ssh ssh,
967 void (*do_mode)(void *data, char *mode, char *val),
972 for (val = conf_get_str_strs(ssh->conf, CONF_ttymodes, NULL, &key);
974 val = conf_get_str_strs(ssh->conf, CONF_ttymodes, key, &key)) {
976 * val[0] is either 'V', indicating that an explicit value
977 * follows it, or 'A' indicating that we should pass the
978 * value through from the local environment via get_ttymode.
981 val = get_ttymode(ssh->frontend, key);
983 do_mode(data, key, val);
987 do_mode(data, key, val + 1); /* skip the 'V' */
991 static int ssh_channelcmp(void *av, void *bv)
993 struct ssh_channel *a = (struct ssh_channel *) av;
994 struct ssh_channel *b = (struct ssh_channel *) bv;
995 if (a->localid < b->localid)
997 if (a->localid > b->localid)
1001 static int ssh_channelfind(void *av, void *bv)
1003 unsigned *a = (unsigned *) av;
1004 struct ssh_channel *b = (struct ssh_channel *) bv;
1005 if (*a < b->localid)
1007 if (*a > b->localid)
1012 static int ssh_rportcmp_ssh1(void *av, void *bv)
1014 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1015 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1017 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
1018 return i < 0 ? -1 : +1;
1019 if (a->dport > b->dport)
1021 if (a->dport < b->dport)
1026 static int ssh_rportcmp_ssh2(void *av, void *bv)
1028 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1029 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1031 if ( (i = strcmp(a->shost, b->shost)) != 0)
1032 return i < 0 ? -1 : +1;
1033 if (a->sport > b->sport)
1035 if (a->sport < b->sport)
1041 * Special form of strcmp which can cope with NULL inputs. NULL is
1042 * defined to sort before even the empty string.
1044 static int nullstrcmp(const char *a, const char *b)
1046 if (a == NULL && b == NULL)
1052 return strcmp(a, b);
1055 static int ssh_portcmp(void *av, void *bv)
1057 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
1058 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
1060 if (a->type > b->type)
1062 if (a->type < b->type)
1064 if (a->addressfamily > b->addressfamily)
1066 if (a->addressfamily < b->addressfamily)
1068 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
1069 return i < 0 ? -1 : +1;
1070 if (a->sport > b->sport)
1072 if (a->sport < b->sport)
1074 if (a->type != 'D') {
1075 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
1076 return i < 0 ? -1 : +1;
1077 if (a->dport > b->dport)
1079 if (a->dport < b->dport)
1085 static int alloc_channel_id(Ssh ssh)
1087 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1088 unsigned low, high, mid;
1090 struct ssh_channel *c;
1093 * First-fit allocation of channel numbers: always pick the
1094 * lowest unused one. To do this, binary-search using the
1095 * counted B-tree to find the largest channel ID which is in a
1096 * contiguous sequence from the beginning. (Precisely
1097 * everything in that sequence must have ID equal to its tree
1098 * index plus CHANNEL_NUMBER_OFFSET.)
1100 tsize = count234(ssh->channels);
1104 while (high - low > 1) {
1105 mid = (high + low) / 2;
1106 c = index234(ssh->channels, mid);
1107 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1108 low = mid; /* this one is fine */
1110 high = mid; /* this one is past it */
1113 * Now low points to either -1, or the tree index of the
1114 * largest ID in the initial sequence.
1117 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
1118 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
1120 return low + 1 + CHANNEL_NUMBER_OFFSET;
1123 static void c_write_stderr(int trusted, const char *buf, int len)
1126 for (i = 0; i < len; i++)
1127 if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60)))
1128 fputc(buf[i], stderr);
1131 static void c_write(Ssh ssh, const char *buf, int len)
1133 if (flags & FLAG_STDERR)
1134 c_write_stderr(1, buf, len);
1136 from_backend(ssh->frontend, 1, buf, len);
1139 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
1141 if (flags & FLAG_STDERR)
1142 c_write_stderr(0, buf, len);
1144 from_backend_untrusted(ssh->frontend, buf, len);
1147 static void c_write_str(Ssh ssh, const char *buf)
1149 c_write(ssh, buf, strlen(buf));
1152 static void ssh_free_packet(struct Packet *pkt)
1157 static struct Packet *ssh_new_packet(void)
1159 struct Packet *pkt = snew(struct Packet);
1161 pkt->body = pkt->data = NULL;
1167 static void ssh1_log_incoming_packet(Ssh ssh, struct Packet *pkt)
1170 struct logblank_t blanks[4];
1176 if (ssh->logomitdata &&
1177 (pkt->type == SSH1_SMSG_STDOUT_DATA ||
1178 pkt->type == SSH1_SMSG_STDERR_DATA ||
1179 pkt->type == SSH1_MSG_CHANNEL_DATA)) {
1180 /* "Session data" packets - omit the data string. */
1181 if (pkt->type == SSH1_MSG_CHANNEL_DATA)
1182 ssh_pkt_getuint32(pkt); /* skip channel id */
1183 blanks[nblanks].offset = pkt->savedpos + 4;
1184 blanks[nblanks].type = PKTLOG_OMIT;
1185 ssh_pkt_getstring(pkt, &str, &slen);
1187 blanks[nblanks].len = slen;
1191 log_packet(ssh->logctx, PKT_INCOMING, pkt->type,
1192 ssh1_pkt_type(pkt->type),
1193 pkt->body, pkt->length, nblanks, blanks, NULL,
1197 static void ssh1_log_outgoing_packet(Ssh ssh, struct Packet *pkt)
1200 struct logblank_t blanks[4];
1205 * For outgoing packets, pkt->length represents the length of the
1206 * whole packet starting at pkt->data (including some header), and
1207 * pkt->body refers to the point within that where the log-worthy
1208 * payload begins. However, incoming packets expect pkt->length to
1209 * represent only the payload length (that is, it's measured from
1210 * pkt->body not from pkt->data). Temporarily adjust our outgoing
1211 * packet to conform to the incoming-packet semantics, so that we
1212 * can analyse it with the ssh_pkt_get functions.
1214 pkt->length -= (pkt->body - pkt->data);
1217 if (ssh->logomitdata &&
1218 (pkt->type == SSH1_CMSG_STDIN_DATA ||
1219 pkt->type == SSH1_MSG_CHANNEL_DATA)) {
1220 /* "Session data" packets - omit the data string. */
1221 if (pkt->type == SSH1_MSG_CHANNEL_DATA)
1222 ssh_pkt_getuint32(pkt); /* skip channel id */
1223 blanks[nblanks].offset = pkt->savedpos + 4;
1224 blanks[nblanks].type = PKTLOG_OMIT;
1225 ssh_pkt_getstring(pkt, &str, &slen);
1227 blanks[nblanks].len = slen;
1232 if ((pkt->type == SSH1_CMSG_AUTH_PASSWORD ||
1233 pkt->type == SSH1_CMSG_AUTH_TIS_RESPONSE ||
1234 pkt->type == SSH1_CMSG_AUTH_CCARD_RESPONSE) &&
1235 conf_get_int(ssh->conf, CONF_logomitpass)) {
1236 /* If this is a password or similar packet, blank the password(s). */
1237 blanks[nblanks].offset = 0;
1238 blanks[nblanks].len = pkt->length;
1239 blanks[nblanks].type = PKTLOG_BLANK;
1241 } else if (pkt->type == SSH1_CMSG_X11_REQUEST_FORWARDING &&
1242 conf_get_int(ssh->conf, CONF_logomitpass)) {
1244 * If this is an X forwarding request packet, blank the fake
1247 * Note that while we blank the X authentication data here, we
1248 * don't take any special action to blank the start of an X11
1249 * channel, so using MIT-MAGIC-COOKIE-1 and actually opening
1250 * an X connection without having session blanking enabled is
1251 * likely to leak your cookie into the log.
1254 ssh_pkt_getstring(pkt, &str, &slen);
1255 blanks[nblanks].offset = pkt->savedpos;
1256 blanks[nblanks].type = PKTLOG_BLANK;
1257 ssh_pkt_getstring(pkt, &str, &slen);
1259 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1264 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1265 ssh1_pkt_type(pkt->data[12]),
1266 pkt->body, pkt->length,
1267 nblanks, blanks, NULL, 0, NULL);
1270 * Undo the above adjustment of pkt->length, to put the packet
1271 * back in the state we found it.
1273 pkt->length += (pkt->body - pkt->data);
1277 * Collect incoming data in the incoming packet buffer.
1278 * Decipher and verify the packet when it is completely read.
1279 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1280 * Update the *data and *datalen variables.
1281 * Return a Packet structure when a packet is completed.
1283 static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1285 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
1287 crBegin(ssh->ssh1_rdpkt_crstate);
1289 st->pktin = ssh_new_packet();
1291 st->pktin->type = 0;
1292 st->pktin->length = 0;
1294 for (st->i = st->len = 0; st->i < 4; st->i++) {
1295 while ((*datalen) == 0)
1297 st->len = (st->len << 8) + **data;
1298 (*data)++, (*datalen)--;
1301 st->pad = 8 - (st->len % 8);
1302 st->biglen = st->len + st->pad;
1303 st->pktin->length = st->len - 5;
1305 if (st->biglen < 0) {
1306 bombout(("Extremely large packet length from server suggests"
1307 " data stream corruption"));
1308 ssh_free_packet(st->pktin);
1312 st->pktin->maxlen = st->biglen;
1313 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1315 st->to_read = st->biglen;
1316 st->p = st->pktin->data;
1317 while (st->to_read > 0) {
1318 st->chunk = st->to_read;
1319 while ((*datalen) == 0)
1321 if (st->chunk > (*datalen))
1322 st->chunk = (*datalen);
1323 memcpy(st->p, *data, st->chunk);
1325 *datalen -= st->chunk;
1327 st->to_read -= st->chunk;
1330 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1331 st->biglen, NULL)) {
1332 bombout(("Network attack (CRC compensation) detected!"));
1333 ssh_free_packet(st->pktin);
1338 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1340 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1341 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1342 if (st->gotcrc != st->realcrc) {
1343 bombout(("Incorrect CRC received on packet"));
1344 ssh_free_packet(st->pktin);
1348 st->pktin->body = st->pktin->data + st->pad + 1;
1350 if (ssh->v1_compressing) {
1351 unsigned char *decompblk;
1353 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1354 st->pktin->body - 1, st->pktin->length + 1,
1355 &decompblk, &decomplen)) {
1356 bombout(("Zlib decompression encountered invalid data"));
1357 ssh_free_packet(st->pktin);
1361 if (st->pktin->maxlen < st->pad + decomplen) {
1362 st->pktin->maxlen = st->pad + decomplen;
1363 st->pktin->data = sresize(st->pktin->data,
1364 st->pktin->maxlen + APIEXTRA,
1366 st->pktin->body = st->pktin->data + st->pad + 1;
1369 memcpy(st->pktin->body - 1, decompblk, decomplen);
1371 st->pktin->length = decomplen - 1;
1374 st->pktin->type = st->pktin->body[-1];
1377 * Now pktin->body and pktin->length identify the semantic content
1378 * of the packet, excluding the initial type byte.
1382 ssh1_log_incoming_packet(ssh, st->pktin);
1384 st->pktin->savedpos = 0;
1386 crFinish(st->pktin);
1389 static void ssh2_log_incoming_packet(Ssh ssh, struct Packet *pkt)
1392 struct logblank_t blanks[4];
1398 if (ssh->logomitdata &&
1399 (pkt->type == SSH2_MSG_CHANNEL_DATA ||
1400 pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)) {
1401 /* "Session data" packets - omit the data string. */
1402 ssh_pkt_getuint32(pkt); /* skip channel id */
1403 if (pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)
1404 ssh_pkt_getuint32(pkt); /* skip extended data type */
1405 blanks[nblanks].offset = pkt->savedpos + 4;
1406 blanks[nblanks].type = PKTLOG_OMIT;
1407 ssh_pkt_getstring(pkt, &str, &slen);
1409 blanks[nblanks].len = slen;
1414 log_packet(ssh->logctx, PKT_INCOMING, pkt->type,
1415 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->type),
1416 pkt->body, pkt->length, nblanks, blanks, &pkt->sequence,
1420 static void ssh2_log_outgoing_packet(Ssh ssh, struct Packet *pkt)
1423 struct logblank_t blanks[4];
1428 * For outgoing packets, pkt->length represents the length of the
1429 * whole packet starting at pkt->data (including some header), and
1430 * pkt->body refers to the point within that where the log-worthy
1431 * payload begins. However, incoming packets expect pkt->length to
1432 * represent only the payload length (that is, it's measured from
1433 * pkt->body not from pkt->data). Temporarily adjust our outgoing
1434 * packet to conform to the incoming-packet semantics, so that we
1435 * can analyse it with the ssh_pkt_get functions.
1437 pkt->length -= (pkt->body - pkt->data);
1440 if (ssh->logomitdata &&
1441 (pkt->type == SSH2_MSG_CHANNEL_DATA ||
1442 pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)) {
1443 /* "Session data" packets - omit the data string. */
1444 ssh_pkt_getuint32(pkt); /* skip channel id */
1445 if (pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)
1446 ssh_pkt_getuint32(pkt); /* skip extended data type */
1447 blanks[nblanks].offset = pkt->savedpos + 4;
1448 blanks[nblanks].type = PKTLOG_OMIT;
1449 ssh_pkt_getstring(pkt, &str, &slen);
1451 blanks[nblanks].len = slen;
1456 if (pkt->type == SSH2_MSG_USERAUTH_REQUEST &&
1457 conf_get_int(ssh->conf, CONF_logomitpass)) {
1458 /* If this is a password packet, blank the password(s). */
1460 ssh_pkt_getstring(pkt, &str, &slen);
1461 ssh_pkt_getstring(pkt, &str, &slen);
1462 ssh_pkt_getstring(pkt, &str, &slen);
1463 if (slen == 8 && !memcmp(str, "password", 8)) {
1464 ssh2_pkt_getbool(pkt);
1465 /* Blank the password field. */
1466 blanks[nblanks].offset = pkt->savedpos;
1467 blanks[nblanks].type = PKTLOG_BLANK;
1468 ssh_pkt_getstring(pkt, &str, &slen);
1470 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1472 /* If there's another password field beyond it (change of
1473 * password), blank that too. */
1474 ssh_pkt_getstring(pkt, &str, &slen);
1476 blanks[nblanks-1].len =
1477 pkt->savedpos - blanks[nblanks].offset;
1480 } else if (ssh->pkt_actx == SSH2_PKTCTX_KBDINTER &&
1481 pkt->type == SSH2_MSG_USERAUTH_INFO_RESPONSE &&
1482 conf_get_int(ssh->conf, CONF_logomitpass)) {
1483 /* If this is a keyboard-interactive response packet, blank
1486 ssh_pkt_getuint32(pkt);
1487 blanks[nblanks].offset = pkt->savedpos;
1488 blanks[nblanks].type = PKTLOG_BLANK;
1490 ssh_pkt_getstring(pkt, &str, &slen);
1494 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1496 } else if (pkt->type == SSH2_MSG_CHANNEL_REQUEST &&
1497 conf_get_int(ssh->conf, CONF_logomitpass)) {
1499 * If this is an X forwarding request packet, blank the fake
1502 * Note that while we blank the X authentication data here, we
1503 * don't take any special action to blank the start of an X11
1504 * channel, so using MIT-MAGIC-COOKIE-1 and actually opening
1505 * an X connection without having session blanking enabled is
1506 * likely to leak your cookie into the log.
1509 ssh_pkt_getuint32(pkt);
1510 ssh_pkt_getstring(pkt, &str, &slen);
1511 if (slen == 7 && !memcmp(str, "x11-req", 0)) {
1512 ssh2_pkt_getbool(pkt);
1513 ssh2_pkt_getbool(pkt);
1514 ssh_pkt_getstring(pkt, &str, &slen);
1515 blanks[nblanks].offset = pkt->savedpos;
1516 blanks[nblanks].type = PKTLOG_BLANK;
1517 ssh_pkt_getstring(pkt, &str, &slen);
1519 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1525 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1526 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]),
1527 pkt->body, pkt->length, nblanks, blanks,
1528 &ssh->v2_outgoing_sequence,
1529 pkt->downstream_id, pkt->additional_log_text);
1532 * Undo the above adjustment of pkt->length, to put the packet
1533 * back in the state we found it.
1535 pkt->length += (pkt->body - pkt->data);
1538 static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1540 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1542 crBegin(ssh->ssh2_rdpkt_crstate);
1544 st->pktin = ssh_new_packet();
1546 st->pktin->type = 0;
1547 st->pktin->length = 0;
1549 st->cipherblk = ssh->sccipher->blksize;
1552 if (st->cipherblk < 8)
1554 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1556 if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_IS_CBC) &&
1559 * When dealing with a CBC-mode cipher, we want to avoid the
1560 * possibility of an attacker's tweaking the ciphertext stream
1561 * so as to cause us to feed the same block to the block
1562 * cipher more than once and thus leak information
1563 * (VU#958563). The way we do this is not to take any
1564 * decisions on the basis of anything we've decrypted until
1565 * we've verified it with a MAC. That includes the packet
1566 * length, so we just read data and check the MAC repeatedly,
1567 * and when the MAC passes, see if the length we've got is
1571 /* May as well allocate the whole lot now. */
1572 st->pktin->data = snewn(OUR_V2_PACKETLIMIT + st->maclen + APIEXTRA,
1575 /* Read an amount corresponding to the MAC. */
1576 for (st->i = 0; st->i < st->maclen; st->i++) {
1577 while ((*datalen) == 0)
1579 st->pktin->data[st->i] = *(*data)++;
1585 unsigned char seq[4];
1586 ssh->scmac->start(ssh->sc_mac_ctx);
1587 PUT_32BIT(seq, st->incoming_sequence);
1588 ssh->scmac->bytes(ssh->sc_mac_ctx, seq, 4);
1591 for (;;) { /* Once around this loop per cipher block. */
1592 /* Read another cipher-block's worth, and tack it onto the end. */
1593 for (st->i = 0; st->i < st->cipherblk; st->i++) {
1594 while ((*datalen) == 0)
1596 st->pktin->data[st->packetlen+st->maclen+st->i] = *(*data)++;
1599 /* Decrypt one more block (a little further back in the stream). */
1600 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1601 st->pktin->data + st->packetlen,
1603 /* Feed that block to the MAC. */
1604 ssh->scmac->bytes(ssh->sc_mac_ctx,
1605 st->pktin->data + st->packetlen, st->cipherblk);
1606 st->packetlen += st->cipherblk;
1607 /* See if that gives us a valid packet. */
1608 if (ssh->scmac->verresult(ssh->sc_mac_ctx,
1609 st->pktin->data + st->packetlen) &&
1610 ((st->len = toint(GET_32BIT(st->pktin->data))) ==
1613 if (st->packetlen >= OUR_V2_PACKETLIMIT) {
1614 bombout(("No valid incoming packet found"));
1615 ssh_free_packet(st->pktin);
1619 st->pktin->maxlen = st->packetlen + st->maclen;
1620 st->pktin->data = sresize(st->pktin->data,
1621 st->pktin->maxlen + APIEXTRA,
1624 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1627 * Acquire and decrypt the first block of the packet. This will
1628 * contain the length and padding details.
1630 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1631 while ((*datalen) == 0)
1633 st->pktin->data[st->i] = *(*data)++;
1638 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1639 st->pktin->data, st->cipherblk);
1642 * Now get the length figure.
1644 st->len = toint(GET_32BIT(st->pktin->data));
1647 * _Completely_ silly lengths should be stomped on before they
1648 * do us any more damage.
1650 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1651 (st->len + 4) % st->cipherblk != 0) {
1652 bombout(("Incoming packet was garbled on decryption"));
1653 ssh_free_packet(st->pktin);
1658 * So now we can work out the total packet length.
1660 st->packetlen = st->len + 4;
1663 * Allocate memory for the rest of the packet.
1665 st->pktin->maxlen = st->packetlen + st->maclen;
1666 st->pktin->data = sresize(st->pktin->data,
1667 st->pktin->maxlen + APIEXTRA,
1671 * Read and decrypt the remainder of the packet.
1673 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1675 while ((*datalen) == 0)
1677 st->pktin->data[st->i] = *(*data)++;
1680 /* Decrypt everything _except_ the MAC. */
1682 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1683 st->pktin->data + st->cipherblk,
1684 st->packetlen - st->cipherblk);
1690 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1691 st->len + 4, st->incoming_sequence)) {
1692 bombout(("Incorrect MAC received on packet"));
1693 ssh_free_packet(st->pktin);
1697 /* Get and sanity-check the amount of random padding. */
1698 st->pad = st->pktin->data[4];
1699 if (st->pad < 4 || st->len - st->pad < 1) {
1700 bombout(("Invalid padding length on received packet"));
1701 ssh_free_packet(st->pktin);
1705 * This enables us to deduce the payload length.
1707 st->payload = st->len - st->pad - 1;
1709 st->pktin->length = st->payload + 5;
1710 st->pktin->encrypted_len = st->packetlen;
1712 st->pktin->sequence = st->incoming_sequence++;
1715 * Decompress packet payload.
1718 unsigned char *newpayload;
1721 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1722 st->pktin->data + 5, st->pktin->length - 5,
1723 &newpayload, &newlen)) {
1724 if (st->pktin->maxlen < newlen + 5) {
1725 st->pktin->maxlen = newlen + 5;
1726 st->pktin->data = sresize(st->pktin->data,
1727 st->pktin->maxlen + APIEXTRA,
1730 st->pktin->length = 5 + newlen;
1731 memcpy(st->pktin->data + 5, newpayload, newlen);
1737 * pktin->body and pktin->length should identify the semantic
1738 * content of the packet, excluding the initial type byte.
1740 st->pktin->type = st->pktin->data[5];
1741 st->pktin->body = st->pktin->data + 6;
1742 st->pktin->length = st->packetlen - 6 - st->pad;
1743 assert(st->pktin->length >= 0); /* one last double-check */
1746 ssh2_log_incoming_packet(ssh, st->pktin);
1748 st->pktin->savedpos = 0;
1750 crFinish(st->pktin);
1753 static struct Packet *ssh2_bare_connection_rdpkt(Ssh ssh, unsigned char **data,
1756 struct rdpkt2_bare_state_tag *st = &ssh->rdpkt2_bare_state;
1758 crBegin(ssh->ssh2_bare_rdpkt_crstate);
1761 * Read the packet length field.
1763 for (st->i = 0; st->i < 4; st->i++) {
1764 while ((*datalen) == 0)
1766 st->length[st->i] = *(*data)++;
1770 st->packetlen = toint(GET_32BIT_MSB_FIRST(st->length));
1771 if (st->packetlen <= 0 || st->packetlen >= OUR_V2_PACKETLIMIT) {
1772 bombout(("Invalid packet length received"));
1776 st->pktin = ssh_new_packet();
1777 st->pktin->data = snewn(st->packetlen, unsigned char);
1779 st->pktin->encrypted_len = st->packetlen;
1781 st->pktin->sequence = st->incoming_sequence++;
1784 * Read the remainder of the packet.
1786 for (st->i = 0; st->i < st->packetlen; st->i++) {
1787 while ((*datalen) == 0)
1789 st->pktin->data[st->i] = *(*data)++;
1794 * pktin->body and pktin->length should identify the semantic
1795 * content of the packet, excluding the initial type byte.
1797 st->pktin->type = st->pktin->data[0];
1798 st->pktin->body = st->pktin->data + 1;
1799 st->pktin->length = st->packetlen - 1;
1802 * Log incoming packet, possibly omitting sensitive fields.
1805 ssh2_log_incoming_packet(ssh, st->pktin);
1807 st->pktin->savedpos = 0;
1809 crFinish(st->pktin);
1812 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1814 int pad, biglen, i, pktoffs;
1818 * XXX various versions of SC (including 8.8.4) screw up the
1819 * register allocation in this function and use the same register
1820 * (D6) for len and as a temporary, with predictable results. The
1821 * following sledgehammer prevents this.
1828 ssh1_log_outgoing_packet(ssh, pkt);
1830 if (ssh->v1_compressing) {
1831 unsigned char *compblk;
1833 zlib_compress_block(ssh->cs_comp_ctx,
1834 pkt->data + 12, pkt->length - 12,
1835 &compblk, &complen);
1836 ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */
1837 memcpy(pkt->data + 12, compblk, complen);
1839 pkt->length = complen + 12;
1842 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1844 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
1845 pad = 8 - (len % 8);
1847 biglen = len + pad; /* len(padding+type+data+CRC) */
1849 for (i = pktoffs; i < 4+8; i++)
1850 pkt->data[i] = random_byte();
1851 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1852 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1853 PUT_32BIT(pkt->data + pktoffs, len);
1856 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1857 pkt->data + pktoffs + 4, biglen);
1859 if (offset_p) *offset_p = pktoffs;
1860 return biglen + 4; /* len(length+padding+type+data+CRC) */
1863 static int s_write(Ssh ssh, void *data, int len)
1866 log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len,
1867 0, NULL, NULL, 0, NULL);
1870 return sk_write(ssh->s, (char *)data, len);
1873 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1875 int len, backlog, offset;
1876 len = s_wrpkt_prepare(ssh, pkt, &offset);
1877 backlog = s_write(ssh, pkt->data + offset, len);
1878 if (backlog > SSH_MAX_BACKLOG)
1879 ssh_throttle_all(ssh, 1, backlog);
1880 ssh_free_packet(pkt);
1883 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1886 len = s_wrpkt_prepare(ssh, pkt, &offset);
1887 if (ssh->deferred_len + len > ssh->deferred_size) {
1888 ssh->deferred_size = ssh->deferred_len + len + 128;
1889 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1893 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1894 pkt->data + offset, len);
1895 ssh->deferred_len += len;
1896 ssh_free_packet(pkt);
1900 * Construct a SSH-1 packet with the specified contents.
1901 * (This all-at-once interface used to be the only one, but now SSH-1
1902 * packets can also be constructed incrementally.)
1904 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
1910 pkt = ssh1_pkt_init(pkttype);
1912 while ((argtype = va_arg(ap, int)) != PKT_END) {
1913 unsigned char *argp, argchar;
1915 unsigned long argint;
1918 /* Actual fields in the packet */
1920 argint = va_arg(ap, int);
1921 ssh_pkt_adduint32(pkt, argint);
1924 argchar = (unsigned char) va_arg(ap, int);
1925 ssh_pkt_addbyte(pkt, argchar);
1928 argp = va_arg(ap, unsigned char *);
1929 arglen = va_arg(ap, int);
1930 ssh_pkt_adddata(pkt, argp, arglen);
1933 sargp = va_arg(ap, char *);
1934 ssh_pkt_addstring(pkt, sargp);
1937 bn = va_arg(ap, Bignum);
1938 ssh1_pkt_addmp(pkt, bn);
1946 static void send_packet(Ssh ssh, int pkttype, ...)
1950 va_start(ap, pkttype);
1951 pkt = construct_packet(ssh, pkttype, ap);
1956 static void defer_packet(Ssh ssh, int pkttype, ...)
1960 va_start(ap, pkttype);
1961 pkt = construct_packet(ssh, pkttype, ap);
1963 s_wrpkt_defer(ssh, pkt);
1966 static int ssh_versioncmp(char *a, char *b)
1969 unsigned long av, bv;
1971 av = strtoul(a, &ae, 10);
1972 bv = strtoul(b, &be, 10);
1974 return (av < bv ? -1 : +1);
1979 av = strtoul(ae, &ae, 10);
1980 bv = strtoul(be, &be, 10);
1982 return (av < bv ? -1 : +1);
1987 * Utility routines for putting an SSH-protocol `string' and
1988 * `uint32' into a hash state.
1990 static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
1992 unsigned char lenblk[4];
1993 PUT_32BIT(lenblk, len);
1994 h->bytes(s, lenblk, 4);
1995 h->bytes(s, str, len);
1998 static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
2000 unsigned char intblk[4];
2001 PUT_32BIT(intblk, i);
2002 h->bytes(s, intblk, 4);
2006 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
2008 static void ssh_pkt_ensure(struct Packet *pkt, int length)
2010 if (pkt->maxlen < length) {
2011 unsigned char *body = pkt->body;
2012 int offset = body ? body - pkt->data : 0;
2013 pkt->maxlen = length + 256;
2014 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
2015 if (body) pkt->body = pkt->data + offset;
2018 static void ssh_pkt_adddata(struct Packet *pkt, const void *data, int len)
2021 ssh_pkt_ensure(pkt, pkt->length);
2022 memcpy(pkt->data + pkt->length - len, data, len);
2024 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
2026 ssh_pkt_adddata(pkt, &byte, 1);
2028 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
2030 ssh_pkt_adddata(pkt, &value, 1);
2032 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
2035 PUT_32BIT(x, value);
2036 ssh_pkt_adddata(pkt, x, 4);
2038 static void ssh_pkt_addstring_start(struct Packet *pkt)
2040 ssh_pkt_adduint32(pkt, 0);
2041 pkt->savedpos = pkt->length;
2043 static void ssh_pkt_addstring_str(struct Packet *pkt, const char *data)
2045 ssh_pkt_adddata(pkt, data, strlen(data));
2046 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
2048 static void ssh_pkt_addstring_data(struct Packet *pkt, const char *data,
2051 ssh_pkt_adddata(pkt, data, len);
2052 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
2054 static void ssh_pkt_addstring(struct Packet *pkt, const char *data)
2056 ssh_pkt_addstring_start(pkt);
2057 ssh_pkt_addstring_str(pkt, data);
2059 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
2061 int len = ssh1_bignum_length(b);
2062 unsigned char *data = snewn(len, unsigned char);
2063 (void) ssh1_write_bignum(data, b);
2064 ssh_pkt_adddata(pkt, data, len);
2067 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
2070 int i, n = (bignum_bitcount(b) + 7) / 8;
2071 p = snewn(n + 1, unsigned char);
2073 for (i = 1; i <= n; i++)
2074 p[i] = bignum_byte(b, n - i);
2076 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
2078 memmove(p, p + i, n + 1 - i);
2082 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
2086 p = ssh2_mpint_fmt(b, &len);
2087 ssh_pkt_addstring_start(pkt);
2088 ssh_pkt_addstring_data(pkt, (char *)p, len);
2092 static struct Packet *ssh1_pkt_init(int pkt_type)
2094 struct Packet *pkt = ssh_new_packet();
2095 pkt->length = 4 + 8; /* space for length + max padding */
2096 ssh_pkt_addbyte(pkt, pkt_type);
2097 pkt->body = pkt->data + pkt->length;
2098 pkt->type = pkt_type;
2099 pkt->downstream_id = 0;
2100 pkt->additional_log_text = NULL;
2104 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
2105 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
2106 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
2107 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
2108 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
2109 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
2110 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
2111 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
2112 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
2114 static struct Packet *ssh2_pkt_init(int pkt_type)
2116 struct Packet *pkt = ssh_new_packet();
2117 pkt->length = 5; /* space for packet length + padding length */
2119 pkt->type = pkt_type;
2120 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
2121 pkt->body = pkt->data + pkt->length; /* after packet type */
2122 pkt->downstream_id = 0;
2123 pkt->additional_log_text = NULL;
2128 * Construct an SSH-2 final-form packet: compress it, encrypt it,
2129 * put the MAC on it. Final packet, ready to be sent, is stored in
2130 * pkt->data. Total length is returned.
2132 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
2134 int cipherblk, maclen, padding, i;
2137 ssh2_log_outgoing_packet(ssh, pkt);
2139 if (ssh->bare_connection) {
2141 * Trivial packet construction for the bare connection
2144 PUT_32BIT(pkt->data + 1, pkt->length - 5);
2145 pkt->body = pkt->data + 1;
2146 ssh->v2_outgoing_sequence++; /* only for diagnostics, really */
2147 return pkt->length - 1;
2151 * Compress packet payload.
2154 unsigned char *newpayload;
2157 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
2159 &newpayload, &newlen)) {
2161 ssh2_pkt_adddata(pkt, newpayload, newlen);
2167 * Add padding. At least four bytes, and must also bring total
2168 * length (minus MAC) up to a multiple of the block size.
2169 * If pkt->forcepad is set, make sure the packet is at least that size
2172 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
2173 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
2175 if (pkt->length + padding < pkt->forcepad)
2176 padding = pkt->forcepad - pkt->length;
2178 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
2179 assert(padding <= 255);
2180 maclen = ssh->csmac ? ssh->csmac->len : 0;
2181 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
2182 pkt->data[4] = padding;
2183 for (i = 0; i < padding; i++)
2184 pkt->data[pkt->length + i] = random_byte();
2185 PUT_32BIT(pkt->data, pkt->length + padding - 4);
2187 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
2188 pkt->length + padding,
2189 ssh->v2_outgoing_sequence);
2190 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
2193 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
2194 pkt->data, pkt->length + padding);
2196 pkt->encrypted_len = pkt->length + padding;
2198 /* Ready-to-send packet starts at pkt->data. We return length. */
2199 pkt->body = pkt->data;
2200 return pkt->length + padding + maclen;
2204 * Routines called from the main SSH code to send packets. There
2205 * are quite a few of these, because we have two separate
2206 * mechanisms for delaying the sending of packets:
2208 * - In order to send an IGNORE message and a password message in
2209 * a single fixed-length blob, we require the ability to
2210 * concatenate the encrypted forms of those two packets _into_ a
2211 * single blob and then pass it to our <network.h> transport
2212 * layer in one go. Hence, there's a deferment mechanism which
2213 * works after packet encryption.
2215 * - In order to avoid sending any connection-layer messages
2216 * during repeat key exchange, we have to queue up any such
2217 * outgoing messages _before_ they are encrypted (and in
2218 * particular before they're allocated sequence numbers), and
2219 * then send them once we've finished.
2221 * I call these mechanisms `defer' and `queue' respectively, so as
2222 * to distinguish them reasonably easily.
2224 * The functions send_noqueue() and defer_noqueue() free the packet
2225 * structure they are passed. Every outgoing packet goes through
2226 * precisely one of these functions in its life; packets passed to
2227 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
2228 * these or get queued, and then when the queue is later emptied
2229 * the packets are all passed to defer_noqueue().
2231 * When using a CBC-mode cipher, it's necessary to ensure that an
2232 * attacker can't provide data to be encrypted using an IV that they
2233 * know. We ensure this by prefixing each packet that might contain
2234 * user data with an SSH_MSG_IGNORE. This is done using the deferral
2235 * mechanism, so in this case send_noqueue() ends up redirecting to
2236 * defer_noqueue(). If you don't like this inefficiency, don't use
2240 static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
2241 static void ssh_pkt_defersend(Ssh);
2244 * Send an SSH-2 packet immediately, without queuing or deferring.
2246 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
2250 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
2251 /* We need to send two packets, so use the deferral mechanism. */
2252 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2253 ssh_pkt_defersend(ssh);
2256 len = ssh2_pkt_construct(ssh, pkt);
2257 backlog = s_write(ssh, pkt->body, len);
2258 if (backlog > SSH_MAX_BACKLOG)
2259 ssh_throttle_all(ssh, 1, backlog);
2261 ssh->outgoing_data_size += pkt->encrypted_len;
2262 if (!ssh->kex_in_progress &&
2263 !ssh->bare_connection &&
2264 ssh->max_data_size != 0 &&
2265 ssh->outgoing_data_size > ssh->max_data_size)
2266 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2268 ssh_free_packet(pkt);
2272 * Defer an SSH-2 packet.
2274 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
2277 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
2278 ssh->deferred_len == 0 && !noignore &&
2279 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2281 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2282 * get encrypted with a known IV.
2284 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2285 ssh2_pkt_addstring_start(ipkt);
2286 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
2288 len = ssh2_pkt_construct(ssh, pkt);
2289 if (ssh->deferred_len + len > ssh->deferred_size) {
2290 ssh->deferred_size = ssh->deferred_len + len + 128;
2291 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2295 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->body, len);
2296 ssh->deferred_len += len;
2297 ssh->deferred_data_size += pkt->encrypted_len;
2298 ssh_free_packet(pkt);
2302 * Queue an SSH-2 packet.
2304 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
2306 assert(ssh->queueing);
2308 if (ssh->queuelen >= ssh->queuesize) {
2309 ssh->queuesize = ssh->queuelen + 32;
2310 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
2313 ssh->queue[ssh->queuelen++] = pkt;
2317 * Either queue or send a packet, depending on whether queueing is
2320 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
2323 ssh2_pkt_queue(ssh, pkt);
2325 ssh2_pkt_send_noqueue(ssh, pkt);
2329 * Either queue or defer a packet, depending on whether queueing is
2332 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
2335 ssh2_pkt_queue(ssh, pkt);
2337 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2341 * Send the whole deferred data block constructed by
2342 * ssh2_pkt_defer() or SSH-1's defer_packet().
2344 * The expected use of the defer mechanism is that you call
2345 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2346 * not currently queueing, this simply sets up deferred_send_data
2347 * and then sends it. If we _are_ currently queueing, the calls to
2348 * ssh2_pkt_defer() put the deferred packets on to the queue
2349 * instead, and therefore ssh_pkt_defersend() has no deferred data
2350 * to send. Hence, there's no need to make it conditional on
2353 static void ssh_pkt_defersend(Ssh ssh)
2356 backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
2357 ssh->deferred_len = ssh->deferred_size = 0;
2358 sfree(ssh->deferred_send_data);
2359 ssh->deferred_send_data = NULL;
2360 if (backlog > SSH_MAX_BACKLOG)
2361 ssh_throttle_all(ssh, 1, backlog);
2363 ssh->outgoing_data_size += ssh->deferred_data_size;
2364 if (!ssh->kex_in_progress &&
2365 !ssh->bare_connection &&
2366 ssh->max_data_size != 0 &&
2367 ssh->outgoing_data_size > ssh->max_data_size)
2368 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2369 ssh->deferred_data_size = 0;
2373 * Send a packet whose length needs to be disguised (typically
2374 * passwords or keyboard-interactive responses).
2376 static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
2382 * The simplest way to do this is to adjust the
2383 * variable-length padding field in the outgoing packet.
2385 * Currently compiled out, because some Cisco SSH servers
2386 * don't like excessively padded packets (bah, why's it
2389 pkt->forcepad = padsize;
2390 ssh2_pkt_send(ssh, pkt);
2395 * If we can't do that, however, an alternative approach is
2396 * to use the pkt_defer mechanism to bundle the packet
2397 * tightly together with an SSH_MSG_IGNORE such that their
2398 * combined length is a constant. So first we construct the
2399 * final form of this packet and defer its sending.
2401 ssh2_pkt_defer(ssh, pkt);
2404 * Now construct an SSH_MSG_IGNORE which includes a string
2405 * that's an exact multiple of the cipher block size. (If
2406 * the cipher is NULL so that the block size is
2407 * unavailable, we don't do this trick at all, because we
2408 * gain nothing by it.)
2410 if (ssh->cscipher &&
2411 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2414 stringlen = (256 - ssh->deferred_len);
2415 stringlen += ssh->cscipher->blksize - 1;
2416 stringlen -= (stringlen % ssh->cscipher->blksize);
2419 * Temporarily disable actual compression, so we
2420 * can guarantee to get this string exactly the
2421 * length we want it. The compression-disabling
2422 * routine should return an integer indicating how
2423 * many bytes we should adjust our string length
2427 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
2429 pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2430 ssh2_pkt_addstring_start(pkt);
2431 for (i = 0; i < stringlen; i++) {
2432 char c = (char) random_byte();
2433 ssh2_pkt_addstring_data(pkt, &c, 1);
2435 ssh2_pkt_defer(ssh, pkt);
2437 ssh_pkt_defersend(ssh);
2442 * Send all queued SSH-2 packets. We send them by means of
2443 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2444 * packets that needed to be lumped together.
2446 static void ssh2_pkt_queuesend(Ssh ssh)
2450 assert(!ssh->queueing);
2452 for (i = 0; i < ssh->queuelen; i++)
2453 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
2456 ssh_pkt_defersend(ssh);
2460 void bndebug(char *string, Bignum b)
2464 p = ssh2_mpint_fmt(b, &len);
2465 debug(("%s", string));
2466 for (i = 0; i < len; i++)
2467 debug((" %02x", p[i]));
2473 static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
2477 p = ssh2_mpint_fmt(b, &len);
2478 hash_string(h, s, p, len);
2483 * Packet decode functions for both SSH-1 and SSH-2.
2485 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
2487 unsigned long value;
2488 if (pkt->length - pkt->savedpos < 4)
2489 return 0; /* arrgh, no way to decline (FIXME?) */
2490 value = GET_32BIT(pkt->body + pkt->savedpos);
2494 static int ssh2_pkt_getbool(struct Packet *pkt)
2496 unsigned long value;
2497 if (pkt->length - pkt->savedpos < 1)
2498 return 0; /* arrgh, no way to decline (FIXME?) */
2499 value = pkt->body[pkt->savedpos] != 0;
2503 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
2508 if (pkt->length - pkt->savedpos < 4)
2510 len = toint(GET_32BIT(pkt->body + pkt->savedpos));
2515 if (pkt->length - pkt->savedpos < *length)
2517 *p = (char *)(pkt->body + pkt->savedpos);
2518 pkt->savedpos += *length;
2520 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
2522 if (pkt->length - pkt->savedpos < length)
2524 pkt->savedpos += length;
2525 return pkt->body + (pkt->savedpos - length);
2527 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2528 unsigned char **keystr)
2532 j = makekey(pkt->body + pkt->savedpos,
2533 pkt->length - pkt->savedpos,
2540 assert(pkt->savedpos < pkt->length);
2544 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2549 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2550 pkt->length - pkt->savedpos, &b);
2558 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2564 ssh_pkt_getstring(pkt, &p, &length);
2569 b = bignum_from_bytes((unsigned char *)p, length);
2574 * Helper function to add an SSH-2 signature blob to a packet.
2575 * Expects to be shown the public key blob as well as the signature
2576 * blob. Normally works just like ssh2_pkt_addstring, but will
2577 * fiddle with the signature packet if necessary for
2578 * BUG_SSH2_RSA_PADDING.
2580 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2581 void *pkblob_v, int pkblob_len,
2582 void *sigblob_v, int sigblob_len)
2584 unsigned char *pkblob = (unsigned char *)pkblob_v;
2585 unsigned char *sigblob = (unsigned char *)sigblob_v;
2587 /* dmemdump(pkblob, pkblob_len); */
2588 /* dmemdump(sigblob, sigblob_len); */
2591 * See if this is in fact an ssh-rsa signature and a buggy
2592 * server; otherwise we can just do this the easy way.
2594 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) && pkblob_len > 4+7+4 &&
2595 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2596 int pos, len, siglen;
2599 * Find the byte length of the modulus.
2602 pos = 4+7; /* skip over "ssh-rsa" */
2603 len = toint(GET_32BIT(pkblob+pos)); /* get length of exponent */
2604 if (len < 0 || len > pkblob_len - pos - 4)
2606 pos += 4 + len; /* skip over exponent */
2607 if (pkblob_len - pos < 4)
2609 len = toint(GET_32BIT(pkblob+pos)); /* find length of modulus */
2610 if (len < 0 || len > pkblob_len - pos - 4)
2612 pos += 4; /* find modulus itself */
2613 while (len > 0 && pkblob[pos] == 0)
2615 /* debug(("modulus length is %d\n", len)); */
2618 * Now find the signature integer.
2620 pos = 4+7; /* skip over "ssh-rsa" */
2621 if (sigblob_len < pos+4)
2623 siglen = toint(GET_32BIT(sigblob+pos));
2624 if (siglen != sigblob_len - pos - 4)
2626 /* debug(("signature length is %d\n", siglen)); */
2628 if (len != siglen) {
2629 unsigned char newlen[4];
2630 ssh2_pkt_addstring_start(pkt);
2631 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2632 /* dmemdump(sigblob, pos); */
2633 pos += 4; /* point to start of actual sig */
2634 PUT_32BIT(newlen, len);
2635 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2636 /* dmemdump(newlen, 4); */
2638 while (len-- > siglen) {
2639 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2640 /* dmemdump(newlen, 1); */
2642 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2643 /* dmemdump(sigblob+pos, siglen); */
2647 /* Otherwise fall through and do it the easy way. We also come
2648 * here as a fallback if we discover above that the key blob
2649 * is misformatted in some way. */
2653 ssh2_pkt_addstring_start(pkt);
2654 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2658 * Examine the remote side's version string and compare it against
2659 * a list of known buggy implementations.
2661 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2663 char *imp; /* pointer to implementation part */
2665 imp += strcspn(imp, "-");
2667 imp += strcspn(imp, "-");
2670 ssh->remote_bugs = 0;
2673 * General notes on server version strings:
2674 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2675 * here -- in particular, we've heard of one that's perfectly happy
2676 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2677 * so we can't distinguish them.
2679 if (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == FORCE_ON ||
2680 (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == AUTO &&
2681 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2682 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2683 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2684 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2686 * These versions don't support SSH1_MSG_IGNORE, so we have
2687 * to use a different defence against password length
2690 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2691 logevent("We believe remote version has SSH-1 ignore bug");
2694 if (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == FORCE_ON ||
2695 (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == AUTO &&
2696 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2698 * These versions need a plain password sent; they can't
2699 * handle having a null and a random length of data after
2702 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2703 logevent("We believe remote version needs a plain SSH-1 password");
2706 if (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == FORCE_ON ||
2707 (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == AUTO &&
2708 (!strcmp(imp, "Cisco-1.25")))) {
2710 * These versions apparently have no clue whatever about
2711 * RSA authentication and will panic and die if they see
2712 * an AUTH_RSA message.
2714 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2715 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2718 if (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == FORCE_ON ||
2719 (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == AUTO &&
2720 !wc_match("* VShell", imp) &&
2721 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2722 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2723 wc_match("2.1 *", imp)))) {
2725 * These versions have the HMAC bug.
2727 ssh->remote_bugs |= BUG_SSH2_HMAC;
2728 logevent("We believe remote version has SSH-2 HMAC bug");
2731 if (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == FORCE_ON ||
2732 (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == AUTO &&
2733 !wc_match("* VShell", imp) &&
2734 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2736 * These versions have the key-derivation bug (failing to
2737 * include the literal shared secret in the hashes that
2738 * generate the keys).
2740 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2741 logevent("We believe remote version has SSH-2 key-derivation bug");
2744 if (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == FORCE_ON ||
2745 (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == AUTO &&
2746 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2747 wc_match("OpenSSH_3.[0-2]*", imp)))) {
2749 * These versions have the SSH-2 RSA padding bug.
2751 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2752 logevent("We believe remote version has SSH-2 RSA padding bug");
2755 if (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == FORCE_ON ||
2756 (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == AUTO &&
2757 wc_match("OpenSSH_2.[0-2]*", imp))) {
2759 * These versions have the SSH-2 session-ID bug in
2760 * public-key authentication.
2762 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2763 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2766 if (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == FORCE_ON ||
2767 (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == AUTO &&
2768 (wc_match("DigiSSH_2.0", imp) ||
2769 wc_match("OpenSSH_2.[0-4]*", imp) ||
2770 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2771 wc_match("Sun_SSH_1.0", imp) ||
2772 wc_match("Sun_SSH_1.0.1", imp) ||
2773 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2774 wc_match("WeOnlyDo-*", imp)))) {
2776 * These versions have the SSH-2 rekey bug.
2778 ssh->remote_bugs |= BUG_SSH2_REKEY;
2779 logevent("We believe remote version has SSH-2 rekey bug");
2782 if (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == FORCE_ON ||
2783 (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == AUTO &&
2784 (wc_match("1.36_sshlib GlobalSCAPE", imp) ||
2785 wc_match("1.36 sshlib: GlobalScape", imp)))) {
2787 * This version ignores our makpkt and needs to be throttled.
2789 ssh->remote_bugs |= BUG_SSH2_MAXPKT;
2790 logevent("We believe remote version ignores SSH-2 maximum packet size");
2793 if (conf_get_int(ssh->conf, CONF_sshbug_ignore2) == FORCE_ON) {
2795 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2796 * none detected automatically.
2798 ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE;
2799 logevent("We believe remote version has SSH-2 ignore bug");
2802 if (conf_get_int(ssh->conf, CONF_sshbug_winadj) == FORCE_ON) {
2804 * Servers that don't support our winadj request for one
2805 * reason or another. Currently, none detected automatically.
2807 ssh->remote_bugs |= BUG_CHOKES_ON_WINADJ;
2808 logevent("We believe remote version has winadj bug");
2813 * The `software version' part of an SSH version string is required
2814 * to contain no spaces or minus signs.
2816 static void ssh_fix_verstring(char *str)
2818 /* Eat "<protoversion>-". */
2819 while (*str && *str != '-') str++;
2820 assert(*str == '-'); str++;
2822 /* Convert minus signs and spaces in the remaining string into
2825 if (*str == '-' || *str == ' ')
2832 * Send an appropriate SSH version string.
2834 static void ssh_send_verstring(Ssh ssh, const char *protoname, char *svers)
2838 if (ssh->version == 2) {
2840 * Construct a v2 version string.
2842 verstring = dupprintf("%s2.0-%s\015\012", protoname, sshver);
2845 * Construct a v1 version string.
2847 assert(!strcmp(protoname, "SSH-")); /* no v1 bare connection protocol */
2848 verstring = dupprintf("SSH-%s-%s\012",
2849 (ssh_versioncmp(svers, "1.5") <= 0 ?
2854 ssh_fix_verstring(verstring + strlen(protoname));
2856 if (ssh->version == 2) {
2859 * Record our version string.
2861 len = strcspn(verstring, "\015\012");
2862 ssh->v_c = snewn(len + 1, char);
2863 memcpy(ssh->v_c, verstring, len);
2867 logeventf(ssh, "We claim version: %.*s",
2868 strcspn(verstring, "\015\012"), verstring);
2869 s_write(ssh, verstring, strlen(verstring));
2873 static int do_ssh_init(Ssh ssh, unsigned char c)
2875 static const char protoname[] = "SSH-";
2877 struct do_ssh_init_state {
2886 crState(do_ssh_init_state);
2890 /* Search for a line beginning with the protocol name prefix in
2893 for (s->i = 0; protoname[s->i]; s->i++) {
2894 if ((char)c != protoname[s->i]) goto no;
2904 s->vstrsize = sizeof(protoname) + 16;
2905 s->vstring = snewn(s->vstrsize, char);
2906 strcpy(s->vstring, protoname);
2907 s->vslen = strlen(protoname);
2910 if (s->vslen >= s->vstrsize - 1) {
2912 s->vstring = sresize(s->vstring, s->vstrsize, char);
2914 s->vstring[s->vslen++] = c;
2917 s->version[s->i] = '\0';
2919 } else if (s->i < sizeof(s->version) - 1)
2920 s->version[s->i++] = c;
2921 } else if (c == '\012')
2923 crReturn(1); /* get another char */
2926 ssh->agentfwd_enabled = FALSE;
2927 ssh->rdpkt2_state.incoming_sequence = 0;
2929 s->vstring[s->vslen] = 0;
2930 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2931 logeventf(ssh, "Server version: %s", s->vstring);
2932 ssh_detect_bugs(ssh, s->vstring);
2935 * Decide which SSH protocol version to support.
2938 /* Anything strictly below "2.0" means protocol 1 is supported. */
2939 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2940 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2941 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2943 if (conf_get_int(ssh->conf, CONF_sshprot) == 0 && !s->proto1) {
2944 bombout(("SSH protocol version 1 required by user but not provided by server"));
2947 if (conf_get_int(ssh->conf, CONF_sshprot) == 3 && !s->proto2) {
2948 bombout(("SSH protocol version 2 required by user but not provided by server"));
2952 if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1))
2957 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2959 /* Send the version string, if we haven't already */
2960 if (conf_get_int(ssh->conf, CONF_sshprot) != 3)
2961 ssh_send_verstring(ssh, protoname, s->version);
2963 if (ssh->version == 2) {
2966 * Record their version string.
2968 len = strcspn(s->vstring, "\015\012");
2969 ssh->v_s = snewn(len + 1, char);
2970 memcpy(ssh->v_s, s->vstring, len);
2974 * Initialise SSH-2 protocol.
2976 ssh->protocol = ssh2_protocol;
2977 ssh2_protocol_setup(ssh);
2978 ssh->s_rdpkt = ssh2_rdpkt;
2981 * Initialise SSH-1 protocol.
2983 ssh->protocol = ssh1_protocol;
2984 ssh1_protocol_setup(ssh);
2985 ssh->s_rdpkt = ssh1_rdpkt;
2987 if (ssh->version == 2)
2988 do_ssh2_transport(ssh, NULL, -1, NULL);
2990 update_specials_menu(ssh->frontend);
2991 ssh->state = SSH_STATE_BEFORE_SIZE;
2992 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
2999 static int do_ssh_connection_init(Ssh ssh, unsigned char c)
3002 * Ordinary SSH begins with the banner "SSH-x.y-...". This is just
3003 * the ssh-connection part, extracted and given a trivial binary
3004 * packet protocol, so we replace 'SSH-' at the start with a new
3005 * name. In proper SSH style (though of course this part of the
3006 * proper SSH protocol _isn't_ subject to this kind of
3007 * DNS-domain-based extension), we define the new name in our
3010 static const char protoname[] =
3011 "SSHCONNECTION@putty.projects.tartarus.org-";
3013 struct do_ssh_connection_init_state {
3021 crState(do_ssh_connection_init_state);
3025 /* Search for a line beginning with the protocol name prefix in
3028 for (s->i = 0; protoname[s->i]; s->i++) {
3029 if ((char)c != protoname[s->i]) goto no;
3039 s->vstrsize = sizeof(protoname) + 16;
3040 s->vstring = snewn(s->vstrsize, char);
3041 strcpy(s->vstring, protoname);
3042 s->vslen = strlen(protoname);
3045 if (s->vslen >= s->vstrsize - 1) {
3047 s->vstring = sresize(s->vstring, s->vstrsize, char);
3049 s->vstring[s->vslen++] = c;
3052 s->version[s->i] = '\0';
3054 } else if (s->i < sizeof(s->version) - 1)
3055 s->version[s->i++] = c;
3056 } else if (c == '\012')
3058 crReturn(1); /* get another char */
3061 ssh->agentfwd_enabled = FALSE;
3062 ssh->rdpkt2_bare_state.incoming_sequence = 0;
3064 s->vstring[s->vslen] = 0;
3065 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
3066 logeventf(ssh, "Server version: %s", s->vstring);
3067 ssh_detect_bugs(ssh, s->vstring);
3070 * Decide which SSH protocol version to support. This is easy in
3071 * bare ssh-connection mode: only 2.0 is legal.
3073 if (ssh_versioncmp(s->version, "2.0") < 0) {
3074 bombout(("Server announces compatibility with SSH-1 in bare ssh-connection protocol"));
3077 if (conf_get_int(ssh->conf, CONF_sshprot) == 0) {
3078 bombout(("Bare ssh-connection protocol cannot be run in SSH-1-only mode"));
3084 logeventf(ssh, "Using bare ssh-connection protocol");
3086 /* Send the version string, if we haven't already */
3087 ssh_send_verstring(ssh, protoname, s->version);
3090 * Initialise bare connection protocol.
3092 ssh->protocol = ssh2_bare_connection_protocol;
3093 ssh2_bare_connection_protocol_setup(ssh);
3094 ssh->s_rdpkt = ssh2_bare_connection_rdpkt;
3096 update_specials_menu(ssh->frontend);
3097 ssh->state = SSH_STATE_BEFORE_SIZE;
3098 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3101 * Get authconn (really just conn) under way.
3103 do_ssh2_authconn(ssh, NULL, 0, NULL);
3110 static void ssh_process_incoming_data(Ssh ssh,
3111 unsigned char **data, int *datalen)
3113 struct Packet *pktin;
3115 pktin = ssh->s_rdpkt(ssh, data, datalen);
3117 ssh->protocol(ssh, NULL, 0, pktin);
3118 ssh_free_packet(pktin);
3122 static void ssh_queue_incoming_data(Ssh ssh,
3123 unsigned char **data, int *datalen)
3125 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
3130 static void ssh_process_queued_incoming_data(Ssh ssh)
3133 unsigned char *data;
3136 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
3137 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
3141 while (!ssh->frozen && len > 0)
3142 ssh_process_incoming_data(ssh, &data, &len);
3145 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
3149 static void ssh_set_frozen(Ssh ssh, int frozen)
3152 sk_set_frozen(ssh->s, frozen);
3153 ssh->frozen = frozen;
3156 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
3158 /* Log raw data, if we're in that mode. */
3160 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
3161 0, NULL, NULL, 0, NULL);
3163 crBegin(ssh->ssh_gotdata_crstate);
3166 * To begin with, feed the characters one by one to the
3167 * protocol initialisation / selection function do_ssh_init().
3168 * When that returns 0, we're done with the initial greeting
3169 * exchange and can move on to packet discipline.
3172 int ret; /* need not be kept across crReturn */
3174 crReturnV; /* more data please */
3175 ret = ssh->do_ssh_init(ssh, *data);
3183 * We emerge from that loop when the initial negotiation is
3184 * over and we have selected an s_rdpkt function. Now pass
3185 * everything to s_rdpkt, and then pass the resulting packets
3186 * to the proper protocol handler.
3190 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
3192 ssh_queue_incoming_data(ssh, &data, &datalen);
3193 /* This uses up all data and cannot cause anything interesting
3194 * to happen; indeed, for anything to happen at all, we must
3195 * return, so break out. */
3197 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
3198 /* This uses up some or all data, and may freeze the
3200 ssh_process_queued_incoming_data(ssh);
3202 /* This uses up some or all data, and may freeze the
3204 ssh_process_incoming_data(ssh, &data, &datalen);
3206 /* FIXME this is probably EBW. */
3207 if (ssh->state == SSH_STATE_CLOSED)
3210 /* We're out of data. Go and get some more. */
3216 static int ssh_do_close(Ssh ssh, int notify_exit)
3219 struct ssh_channel *c;
3221 ssh->state = SSH_STATE_CLOSED;
3222 expire_timer_context(ssh);
3227 notify_remote_exit(ssh->frontend);
3232 * Now we must shut down any port- and X-forwarded channels going
3233 * through this connection.
3235 if (ssh->channels) {
3236 while (NULL != (c = index234(ssh->channels, 0))) {
3239 x11_close(c->u.x11.xconn);
3242 case CHAN_SOCKDATA_DORMANT:
3243 pfd_close(c->u.pfd.pf);
3246 del234(ssh->channels, c); /* moving next one to index 0 */
3247 if (ssh->version == 2)
3248 bufchain_clear(&c->v.v2.outbuffer);
3253 * Go through port-forwardings, and close any associated
3254 * listening sockets.
3256 if (ssh->portfwds) {
3257 struct ssh_portfwd *pf;
3258 while (NULL != (pf = index234(ssh->portfwds, 0))) {
3259 /* Dispose of any listening socket. */
3261 pfl_terminate(pf->local);
3262 del234(ssh->portfwds, pf); /* moving next one to index 0 */
3265 freetree234(ssh->portfwds);
3266 ssh->portfwds = NULL;
3272 static void ssh_socket_log(Plug plug, int type, SockAddr addr, int port,
3273 const char *error_msg, int error_code)
3275 Ssh ssh = (Ssh) plug;
3276 char addrbuf[256], *msg;
3278 if (ssh->attempting_connshare) {
3280 * While we're attempting connection sharing, don't loudly log
3281 * everything that happens. Real TCP connections need to be
3282 * logged when we _start_ trying to connect, because it might
3283 * be ages before they respond if something goes wrong; but
3284 * connection sharing is local and quick to respond, and it's
3285 * sufficient to simply wait and see whether it worked
3289 sk_getaddr(addr, addrbuf, lenof(addrbuf));
3292 if (sk_addr_needs_port(addr)) {
3293 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
3295 msg = dupprintf("Connecting to %s", addrbuf);
3298 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
3306 void ssh_connshare_log(Ssh ssh, int event, const char *logtext,
3307 const char *ds_err, const char *us_err)
3309 if (event == SHARE_NONE) {
3310 /* In this case, 'logtext' is an error message indicating a
3311 * reason why connection sharing couldn't be set up _at all_.
3312 * Failing that, ds_err and us_err indicate why we couldn't be
3313 * a downstream and an upstream respectively. */
3315 logeventf(ssh, "Could not set up connection sharing: %s", logtext);
3318 logeventf(ssh, "Could not set up connection sharing"
3319 " as downstream: %s", ds_err);
3321 logeventf(ssh, "Could not set up connection sharing"
3322 " as upstream: %s", us_err);
3324 } else if (event == SHARE_DOWNSTREAM) {
3325 /* In this case, 'logtext' is a local endpoint address */
3326 logeventf(ssh, "Using existing shared connection at %s", logtext);
3327 /* Also we should mention this in the console window to avoid
3328 * confusing users as to why this window doesn't behave the
3330 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3331 c_write_str(ssh,"Reusing a shared connection to this server.\r\n");
3333 } else if (event == SHARE_UPSTREAM) {
3334 /* In this case, 'logtext' is a local endpoint address too */
3335 logeventf(ssh, "Sharing this connection at %s", logtext);
3339 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
3342 Ssh ssh = (Ssh) plug;
3343 int need_notify = ssh_do_close(ssh, FALSE);
3346 if (!ssh->close_expected)
3347 error_msg = "Server unexpectedly closed network connection";
3349 error_msg = "Server closed network connection";
3352 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
3356 notify_remote_exit(ssh->frontend);
3359 logevent(error_msg);
3360 if (!ssh->close_expected || !ssh->clean_exit)
3361 connection_fatal(ssh->frontend, "%s", error_msg);
3365 static int ssh_receive(Plug plug, int urgent, char *data, int len)
3367 Ssh ssh = (Ssh) plug;
3368 ssh_gotdata(ssh, (unsigned char *)data, len);
3369 if (ssh->state == SSH_STATE_CLOSED) {
3370 ssh_do_close(ssh, TRUE);
3376 static void ssh_sent(Plug plug, int bufsize)
3378 Ssh ssh = (Ssh) plug;
3380 * If the send backlog on the SSH socket itself clears, we
3381 * should unthrottle the whole world if it was throttled.
3383 if (bufsize < SSH_MAX_BACKLOG)
3384 ssh_throttle_all(ssh, 0, bufsize);
3388 * Connect to specified host and port.
3389 * Returns an error message, or NULL on success.
3390 * Also places the canonical host name into `realhost'. It must be
3391 * freed by the caller.
3393 static const char *connect_to_host(Ssh ssh, char *host, int port,
3394 char **realhost, int nodelay, int keepalive)
3396 static const struct plug_function_table fn_table = {
3407 int addressfamily, sshprot;
3409 loghost = conf_get_str(ssh->conf, CONF_loghost);
3413 ssh->savedhost = dupstr(loghost);
3414 ssh->savedport = 22; /* default ssh port */
3417 * A colon suffix on savedhost also lets us affect
3420 * (FIXME: do something about IPv6 address literals here.)
3422 colon = strrchr(ssh->savedhost, ':');
3426 ssh->savedport = atoi(colon);
3429 ssh->savedhost = dupstr(host);
3431 port = 22; /* default ssh port */
3432 ssh->savedport = port;
3435 ssh->fn = &fn_table; /* make 'ssh' usable as a Plug */
3438 * Try connection-sharing, in case that means we don't open a
3439 * socket after all. ssh_connection_sharing_init will connect to a
3440 * previously established upstream if it can, and failing that,
3441 * establish a listening socket for _us_ to be the upstream. In
3442 * the latter case it will return NULL just as if it had done
3443 * nothing, because here we only need to care if we're a
3444 * downstream and need to do our connection setup differently.
3446 ssh->connshare = NULL;
3447 ssh->attempting_connshare = TRUE; /* affects socket logging behaviour */
3448 ssh->s = ssh_connection_sharing_init(ssh->savedhost, ssh->savedport,
3449 ssh->conf, ssh, &ssh->connshare);
3450 ssh->attempting_connshare = FALSE;
3451 if (ssh->s != NULL) {
3453 * We are a downstream.
3455 ssh->bare_connection = TRUE;
3456 ssh->do_ssh_init = do_ssh_connection_init;
3457 ssh->fullhostname = NULL;
3458 *realhost = dupstr(host); /* best we can do */
3461 * We're not a downstream, so open a normal socket.
3463 ssh->do_ssh_init = do_ssh_init;
3468 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
3469 logeventf(ssh, "Looking up host \"%s\"%s", host,
3470 (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
3471 (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
3472 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily);
3473 if ((err = sk_addr_error(addr)) != NULL) {
3477 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3479 ssh->s = new_connection(addr, *realhost, port,
3480 0, 1, nodelay, keepalive,
3481 (Plug) ssh, ssh->conf);
3482 if ((err = sk_socket_error(ssh->s)) != NULL) {
3484 notify_remote_exit(ssh->frontend);
3490 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3491 * send the version string too.
3493 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3496 if (sshprot == 3 && !ssh->bare_connection) {
3498 ssh_send_verstring(ssh, "SSH-", NULL);
3502 * loghost, if configured, overrides realhost.
3506 *realhost = dupstr(loghost);
3513 * Throttle or unthrottle the SSH connection.
3515 static void ssh_throttle_conn(Ssh ssh, int adjust)
3517 int old_count = ssh->conn_throttle_count;
3518 ssh->conn_throttle_count += adjust;
3519 assert(ssh->conn_throttle_count >= 0);
3520 if (ssh->conn_throttle_count && !old_count) {
3521 ssh_set_frozen(ssh, 1);
3522 } else if (!ssh->conn_throttle_count && old_count) {
3523 ssh_set_frozen(ssh, 0);
3528 * Throttle or unthrottle _all_ local data streams (for when sends
3529 * on the SSH connection itself back up).
3531 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3534 struct ssh_channel *c;
3536 if (enable == ssh->throttled_all)
3538 ssh->throttled_all = enable;
3539 ssh->overall_bufsize = bufsize;
3542 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3544 case CHAN_MAINSESSION:
3546 * This is treated separately, outside the switch.
3550 x11_override_throttle(c->u.x11.xconn, enable);
3553 /* Agent channels require no buffer management. */
3556 pfd_override_throttle(c->u.pfd.pf, enable);
3562 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3564 Ssh ssh = (Ssh) sshv;
3566 ssh->agent_response = reply;
3567 ssh->agent_response_len = replylen;
3569 if (ssh->version == 1)
3570 do_ssh1_login(ssh, NULL, -1, NULL);
3572 do_ssh2_authconn(ssh, NULL, -1, NULL);
3575 static void ssh_dialog_callback(void *sshv, int ret)
3577 Ssh ssh = (Ssh) sshv;
3579 ssh->user_response = ret;
3581 if (ssh->version == 1)
3582 do_ssh1_login(ssh, NULL, -1, NULL);
3584 do_ssh2_transport(ssh, NULL, -1, NULL);
3587 * This may have unfrozen the SSH connection, so do a
3590 ssh_process_queued_incoming_data(ssh);
3593 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3595 struct ssh_channel *c = (struct ssh_channel *)cv;
3597 void *sentreply = reply;
3599 c->u.a.outstanding_requests--;
3601 /* Fake SSH_AGENT_FAILURE. */
3602 sentreply = "\0\0\0\1\5";
3605 if (ssh->version == 2) {
3606 ssh2_add_channel_data(c, sentreply, replylen);
3609 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3610 PKT_INT, c->remoteid,
3612 PKT_DATA, sentreply, replylen,
3618 * If we've already seen an incoming EOF but haven't sent an
3619 * outgoing one, this may be the moment to send it.
3621 if (c->u.a.outstanding_requests == 0 && (c->closes & CLOSES_RCVD_EOF))
3622 sshfwd_write_eof(c);
3626 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3627 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3628 * => log `wire_reason'.
3630 static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
3631 int code, int clean_exit)
3635 client_reason = wire_reason;
3637 error = dupprintf("Disconnected: %s", client_reason);
3639 error = dupstr("Disconnected");
3641 if (ssh->version == 1) {
3642 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3644 } else if (ssh->version == 2) {
3645 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3646 ssh2_pkt_adduint32(pktout, code);
3647 ssh2_pkt_addstring(pktout, wire_reason);
3648 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3649 ssh2_pkt_send_noqueue(ssh, pktout);
3652 ssh->close_expected = TRUE;
3653 ssh->clean_exit = clean_exit;
3654 ssh_closing((Plug)ssh, error, 0, 0);
3659 * Handle the key exchange and user authentication phases.
3661 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
3662 struct Packet *pktin)
3665 unsigned char cookie[8], *ptr;
3666 struct MD5Context md5c;
3667 struct do_ssh1_login_state {
3670 unsigned char *rsabuf, *keystr1, *keystr2;
3671 unsigned long supported_ciphers_mask, supported_auths_mask;
3672 int tried_publickey, tried_agent;
3673 int tis_auth_refused, ccard_auth_refused;
3674 unsigned char session_id[16];
3676 void *publickey_blob;
3677 int publickey_bloblen;
3678 char *publickey_comment;
3679 int publickey_encrypted;
3680 prompts_t *cur_prompt;
3683 unsigned char request[5], *response, *p;
3693 struct RSAKey servkey, hostkey;
3695 crState(do_ssh1_login_state);
3702 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
3703 bombout(("Public key packet not received"));
3707 logevent("Received public keys");
3709 ptr = ssh_pkt_getdata(pktin, 8);
3711 bombout(("SSH-1 public key packet stopped before random cookie"));
3714 memcpy(cookie, ptr, 8);
3716 if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) ||
3717 !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) {
3718 bombout(("Failed to read SSH-1 public keys from public key packet"));
3723 * Log the host key fingerprint.
3727 logevent("Host key fingerprint is:");
3728 strcpy(logmsg, " ");
3729 s->hostkey.comment = NULL;
3730 rsa_fingerprint(logmsg + strlen(logmsg),
3731 sizeof(logmsg) - strlen(logmsg), &s->hostkey);
3735 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3736 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3737 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
3738 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
3739 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
3741 ssh->v1_local_protoflags =
3742 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3743 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
3746 MD5Update(&md5c, s->keystr2, s->hostkey.bytes);
3747 MD5Update(&md5c, s->keystr1, s->servkey.bytes);
3748 MD5Update(&md5c, cookie, 8);
3749 MD5Final(s->session_id, &md5c);
3751 for (i = 0; i < 32; i++)
3752 ssh->session_key[i] = random_byte();
3755 * Verify that the `bits' and `bytes' parameters match.
3757 if (s->hostkey.bits > s->hostkey.bytes * 8 ||
3758 s->servkey.bits > s->servkey.bytes * 8) {
3759 bombout(("SSH-1 public keys were badly formatted"));
3763 s->len = (s->hostkey.bytes > s->servkey.bytes ?
3764 s->hostkey.bytes : s->servkey.bytes);
3766 s->rsabuf = snewn(s->len, unsigned char);
3769 * Verify the host key.
3773 * First format the key into a string.
3775 int len = rsastr_len(&s->hostkey);
3776 char fingerprint[100];
3777 char *keystr = snewn(len, char);
3778 rsastr_fmt(keystr, &s->hostkey);
3779 rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey);
3781 ssh_set_frozen(ssh, 1);
3782 s->dlgret = verify_ssh_host_key(ssh->frontend,
3783 ssh->savedhost, ssh->savedport,
3784 "rsa", keystr, fingerprint,
3785 ssh_dialog_callback, ssh);
3787 if (s->dlgret < 0) {
3791 bombout(("Unexpected data from server while waiting"
3792 " for user host key response"));
3795 } while (pktin || inlen > 0);
3796 s->dlgret = ssh->user_response;
3798 ssh_set_frozen(ssh, 0);
3800 if (s->dlgret == 0) {
3801 ssh_disconnect(ssh, "User aborted at host key verification",
3807 for (i = 0; i < 32; i++) {
3808 s->rsabuf[i] = ssh->session_key[i];
3810 s->rsabuf[i] ^= s->session_id[i];
3813 if (s->hostkey.bytes > s->servkey.bytes) {
3814 ret = rsaencrypt(s->rsabuf, 32, &s->servkey);
3816 ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey);
3818 ret = rsaencrypt(s->rsabuf, 32, &s->hostkey);
3820 ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey);
3823 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3827 logevent("Encrypted session key");
3830 int cipher_chosen = 0, warn = 0;
3831 char *cipher_string = NULL;
3833 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
3834 int next_cipher = conf_get_int_int(ssh->conf,
3835 CONF_ssh_cipherlist, i);
3836 if (next_cipher == CIPHER_WARN) {
3837 /* If/when we choose a cipher, warn about it */
3839 } else if (next_cipher == CIPHER_AES) {
3840 /* XXX Probably don't need to mention this. */
3841 logevent("AES not supported in SSH-1, skipping");
3843 switch (next_cipher) {
3844 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
3845 cipher_string = "3DES"; break;
3846 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
3847 cipher_string = "Blowfish"; break;
3848 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
3849 cipher_string = "single-DES"; break;
3851 if (s->supported_ciphers_mask & (1 << s->cipher_type))
3855 if (!cipher_chosen) {
3856 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
3857 bombout(("Server violates SSH-1 protocol by not "
3858 "supporting 3DES encryption"));
3860 /* shouldn't happen */
3861 bombout(("No supported ciphers found"));
3865 /* Warn about chosen cipher if necessary. */
3867 ssh_set_frozen(ssh, 1);
3868 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3869 ssh_dialog_callback, ssh);
3870 if (s->dlgret < 0) {
3874 bombout(("Unexpected data from server while waiting"
3875 " for user response"));
3878 } while (pktin || inlen > 0);
3879 s->dlgret = ssh->user_response;
3881 ssh_set_frozen(ssh, 0);
3882 if (s->dlgret == 0) {
3883 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3890 switch (s->cipher_type) {
3891 case SSH_CIPHER_3DES:
3892 logevent("Using 3DES encryption");
3894 case SSH_CIPHER_DES:
3895 logevent("Using single-DES encryption");
3897 case SSH_CIPHER_BLOWFISH:
3898 logevent("Using Blowfish encryption");
3902 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3903 PKT_CHAR, s->cipher_type,
3904 PKT_DATA, cookie, 8,
3905 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3906 PKT_DATA, s->rsabuf, s->len,
3907 PKT_INT, ssh->v1_local_protoflags, PKT_END);
3909 logevent("Trying to enable encryption...");
3913 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3914 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3916 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3917 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
3918 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
3920 ssh->crcda_ctx = crcda_make_context();
3921 logevent("Installing CRC compensation attack detector");
3923 if (s->servkey.modulus) {
3924 sfree(s->servkey.modulus);
3925 s->servkey.modulus = NULL;
3927 if (s->servkey.exponent) {
3928 sfree(s->servkey.exponent);
3929 s->servkey.exponent = NULL;
3931 if (s->hostkey.modulus) {
3932 sfree(s->hostkey.modulus);
3933 s->hostkey.modulus = NULL;
3935 if (s->hostkey.exponent) {
3936 sfree(s->hostkey.exponent);
3937 s->hostkey.exponent = NULL;
3941 if (pktin->type != SSH1_SMSG_SUCCESS) {
3942 bombout(("Encryption not successfully enabled"));
3946 logevent("Successfully started encryption");
3948 fflush(stdout); /* FIXME eh? */
3950 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
3951 int ret; /* need not be kept over crReturn */
3952 s->cur_prompt = new_prompts(ssh->frontend);
3953 s->cur_prompt->to_server = TRUE;
3954 s->cur_prompt->name = dupstr("SSH login name");
3955 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
3956 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3959 crWaitUntil(!pktin);
3960 ret = get_userpass_input(s->cur_prompt, in, inlen);
3965 * Failed to get a username. Terminate.
3967 free_prompts(s->cur_prompt);
3968 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
3971 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
3972 free_prompts(s->cur_prompt);
3975 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
3977 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
3979 if (flags & FLAG_INTERACTIVE &&
3980 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3981 c_write_str(ssh, userlog);
3982 c_write_str(ssh, "\r\n");
3990 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
3991 /* We must not attempt PK auth. Pretend we've already tried it. */
3992 s->tried_publickey = s->tried_agent = 1;
3994 s->tried_publickey = s->tried_agent = 0;
3996 s->tis_auth_refused = s->ccard_auth_refused = 0;
3998 * Load the public half of any configured keyfile for later use.
4000 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4001 if (!filename_is_null(s->keyfile)) {
4003 logeventf(ssh, "Reading private key file \"%.150s\"",
4004 filename_to_str(s->keyfile));
4005 keytype = key_type(s->keyfile);
4006 if (keytype == SSH_KEYTYPE_SSH1) {
4008 if (rsakey_pubblob(s->keyfile,
4009 &s->publickey_blob, &s->publickey_bloblen,
4010 &s->publickey_comment, &error)) {
4011 s->publickey_encrypted = rsakey_encrypted(s->keyfile,
4015 logeventf(ssh, "Unable to load private key (%s)", error);
4016 msgbuf = dupprintf("Unable to load private key file "
4017 "\"%.150s\" (%s)\r\n",
4018 filename_to_str(s->keyfile),
4020 c_write_str(ssh, msgbuf);
4022 s->publickey_blob = NULL;
4026 logeventf(ssh, "Unable to use this key file (%s)",
4027 key_type_to_str(keytype));
4028 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4030 filename_to_str(s->keyfile),
4031 key_type_to_str(keytype));
4032 c_write_str(ssh, msgbuf);
4034 s->publickey_blob = NULL;
4037 s->publickey_blob = NULL;
4039 while (pktin->type == SSH1_SMSG_FAILURE) {
4040 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
4042 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
4044 * Attempt RSA authentication using Pageant.
4050 logevent("Pageant is running. Requesting keys.");
4052 /* Request the keys held by the agent. */
4053 PUT_32BIT(s->request, 1);
4054 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
4055 if (!agent_query(s->request, 5, &r, &s->responselen,
4056 ssh_agent_callback, ssh)) {
4060 bombout(("Unexpected data from server while waiting"
4061 " for agent response"));
4064 } while (pktin || inlen > 0);
4065 r = ssh->agent_response;
4066 s->responselen = ssh->agent_response_len;
4068 s->response = (unsigned char *) r;
4069 if (s->response && s->responselen >= 5 &&
4070 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
4071 s->p = s->response + 5;
4072 s->nkeys = toint(GET_32BIT(s->p));
4074 logeventf(ssh, "Pageant reported negative key count %d",
4079 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
4080 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4081 unsigned char *pkblob = s->p;
4085 do { /* do while (0) to make breaking easy */
4086 n = ssh1_read_bignum
4087 (s->p, toint(s->responselen-(s->p-s->response)),
4092 n = ssh1_read_bignum
4093 (s->p, toint(s->responselen-(s->p-s->response)),
4098 if (s->responselen - (s->p-s->response) < 4)
4100 s->commentlen = toint(GET_32BIT(s->p));
4102 if (s->commentlen < 0 ||
4103 toint(s->responselen - (s->p-s->response)) <
4106 s->commentp = (char *)s->p;
4107 s->p += s->commentlen;
4111 logevent("Pageant key list packet was truncated");
4115 if (s->publickey_blob) {
4116 if (!memcmp(pkblob, s->publickey_blob,
4117 s->publickey_bloblen)) {
4118 logeventf(ssh, "Pageant key #%d matches "
4119 "configured key file", s->keyi);
4120 s->tried_publickey = 1;
4122 /* Skip non-configured key */
4125 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
4126 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4127 PKT_BIGNUM, s->key.modulus, PKT_END);
4129 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4130 logevent("Key refused");
4133 logevent("Received RSA challenge");
4134 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4135 bombout(("Server's RSA challenge was badly formatted"));
4140 char *agentreq, *q, *ret;
4143 len = 1 + 4; /* message type, bit count */
4144 len += ssh1_bignum_length(s->key.exponent);
4145 len += ssh1_bignum_length(s->key.modulus);
4146 len += ssh1_bignum_length(s->challenge);
4147 len += 16; /* session id */
4148 len += 4; /* response format */
4149 agentreq = snewn(4 + len, char);
4150 PUT_32BIT(agentreq, len);
4152 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
4153 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
4155 q += ssh1_write_bignum(q, s->key.exponent);
4156 q += ssh1_write_bignum(q, s->key.modulus);
4157 q += ssh1_write_bignum(q, s->challenge);
4158 memcpy(q, s->session_id, 16);
4160 PUT_32BIT(q, 1); /* response format */
4161 if (!agent_query(agentreq, len + 4, &vret, &retlen,
4162 ssh_agent_callback, ssh)) {
4167 bombout(("Unexpected data from server"
4168 " while waiting for agent"
4172 } while (pktin || inlen > 0);
4173 vret = ssh->agent_response;
4174 retlen = ssh->agent_response_len;
4179 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
4180 logevent("Sending Pageant's response");
4181 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4182 PKT_DATA, ret + 5, 16,
4186 if (pktin->type == SSH1_SMSG_SUCCESS) {
4188 ("Pageant's response accepted");
4189 if (flags & FLAG_VERBOSE) {
4190 c_write_str(ssh, "Authenticated using"
4192 c_write(ssh, s->commentp,
4194 c_write_str(ssh, "\" from agent\r\n");
4199 ("Pageant's response not accepted");
4202 ("Pageant failed to answer challenge");
4206 logevent("No reply received from Pageant");
4209 freebn(s->key.exponent);
4210 freebn(s->key.modulus);
4211 freebn(s->challenge);
4216 if (s->publickey_blob && !s->tried_publickey)
4217 logevent("Configured key file not in Pageant");
4219 logevent("Failed to get reply from Pageant");
4224 if (s->publickey_blob && !s->tried_publickey) {
4226 * Try public key authentication with the specified
4229 int got_passphrase; /* need not be kept over crReturn */
4230 if (flags & FLAG_VERBOSE)
4231 c_write_str(ssh, "Trying public key authentication.\r\n");
4232 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4233 logeventf(ssh, "Trying public key \"%s\"",
4234 filename_to_str(s->keyfile));
4235 s->tried_publickey = 1;
4236 got_passphrase = FALSE;
4237 while (!got_passphrase) {
4239 * Get a passphrase, if necessary.
4241 char *passphrase = NULL; /* only written after crReturn */
4243 if (!s->publickey_encrypted) {
4244 if (flags & FLAG_VERBOSE)
4245 c_write_str(ssh, "No passphrase required.\r\n");
4248 int ret; /* need not be kept over crReturn */
4249 s->cur_prompt = new_prompts(ssh->frontend);
4250 s->cur_prompt->to_server = FALSE;
4251 s->cur_prompt->name = dupstr("SSH key passphrase");
4252 add_prompt(s->cur_prompt,
4253 dupprintf("Passphrase for key \"%.100s\": ",
4254 s->publickey_comment), FALSE);
4255 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4258 crWaitUntil(!pktin);
4259 ret = get_userpass_input(s->cur_prompt, in, inlen);
4263 /* Failed to get a passphrase. Terminate. */
4264 free_prompts(s->cur_prompt);
4265 ssh_disconnect(ssh, NULL, "Unable to authenticate",
4269 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
4270 free_prompts(s->cur_prompt);
4273 * Try decrypting key with passphrase.
4275 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4276 ret = loadrsakey(s->keyfile, &s->key, passphrase,
4279 smemclr(passphrase, strlen(passphrase));
4283 /* Correct passphrase. */
4284 got_passphrase = TRUE;
4285 } else if (ret == 0) {
4286 c_write_str(ssh, "Couldn't load private key from ");
4287 c_write_str(ssh, filename_to_str(s->keyfile));
4288 c_write_str(ssh, " (");
4289 c_write_str(ssh, error);
4290 c_write_str(ssh, ").\r\n");
4291 got_passphrase = FALSE;
4292 break; /* go and try something else */
4293 } else if (ret == -1) {
4294 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
4295 got_passphrase = FALSE;
4298 assert(0 && "unexpected return from loadrsakey()");
4299 got_passphrase = FALSE; /* placate optimisers */
4303 if (got_passphrase) {
4306 * Send a public key attempt.
4308 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4309 PKT_BIGNUM, s->key.modulus, PKT_END);
4312 if (pktin->type == SSH1_SMSG_FAILURE) {
4313 c_write_str(ssh, "Server refused our public key.\r\n");
4314 continue; /* go and try something else */
4316 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4317 bombout(("Bizarre response to offer of public key"));
4323 unsigned char buffer[32];
4324 Bignum challenge, response;
4326 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4327 bombout(("Server's RSA challenge was badly formatted"));
4330 response = rsadecrypt(challenge, &s->key);
4331 freebn(s->key.private_exponent);/* burn the evidence */
4333 for (i = 0; i < 32; i++) {
4334 buffer[i] = bignum_byte(response, 31 - i);
4338 MD5Update(&md5c, buffer, 32);
4339 MD5Update(&md5c, s->session_id, 16);
4340 MD5Final(buffer, &md5c);
4342 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4343 PKT_DATA, buffer, 16, PKT_END);
4350 if (pktin->type == SSH1_SMSG_FAILURE) {
4351 if (flags & FLAG_VERBOSE)
4352 c_write_str(ssh, "Failed to authenticate with"
4353 " our public key.\r\n");
4354 continue; /* go and try something else */
4355 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4356 bombout(("Bizarre response to RSA authentication response"));
4360 break; /* we're through! */
4366 * Otherwise, try various forms of password-like authentication.
4368 s->cur_prompt = new_prompts(ssh->frontend);
4370 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4371 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
4372 !s->tis_auth_refused) {
4373 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
4374 logevent("Requested TIS authentication");
4375 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
4377 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
4378 logevent("TIS authentication declined");
4379 if (flags & FLAG_INTERACTIVE)
4380 c_write_str(ssh, "TIS authentication refused.\r\n");
4381 s->tis_auth_refused = 1;
4386 char *instr_suf, *prompt;
4388 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4390 bombout(("TIS challenge packet was badly formed"));
4393 logevent("Received TIS challenge");
4394 s->cur_prompt->to_server = TRUE;
4395 s->cur_prompt->name = dupstr("SSH TIS authentication");
4396 /* Prompt heuristic comes from OpenSSH */
4397 if (memchr(challenge, '\n', challengelen)) {
4398 instr_suf = dupstr("");
4399 prompt = dupprintf("%.*s", challengelen, challenge);
4401 instr_suf = dupprintf("%.*s", challengelen, challenge);
4402 prompt = dupstr("Response: ");
4404 s->cur_prompt->instruction =
4405 dupprintf("Using TIS authentication.%s%s",
4406 (*instr_suf) ? "\n" : "",
4408 s->cur_prompt->instr_reqd = TRUE;
4409 add_prompt(s->cur_prompt, prompt, FALSE);
4413 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4414 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
4415 !s->ccard_auth_refused) {
4416 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
4417 logevent("Requested CryptoCard authentication");
4418 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
4420 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
4421 logevent("CryptoCard authentication declined");
4422 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4423 s->ccard_auth_refused = 1;
4428 char *instr_suf, *prompt;
4430 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4432 bombout(("CryptoCard challenge packet was badly formed"));
4435 logevent("Received CryptoCard challenge");
4436 s->cur_prompt->to_server = TRUE;
4437 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4438 s->cur_prompt->name_reqd = FALSE;
4439 /* Prompt heuristic comes from OpenSSH */
4440 if (memchr(challenge, '\n', challengelen)) {
4441 instr_suf = dupstr("");
4442 prompt = dupprintf("%.*s", challengelen, challenge);
4444 instr_suf = dupprintf("%.*s", challengelen, challenge);
4445 prompt = dupstr("Response: ");
4447 s->cur_prompt->instruction =
4448 dupprintf("Using CryptoCard authentication.%s%s",
4449 (*instr_suf) ? "\n" : "",
4451 s->cur_prompt->instr_reqd = TRUE;
4452 add_prompt(s->cur_prompt, prompt, FALSE);
4456 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4457 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4458 bombout(("No supported authentication methods available"));
4461 s->cur_prompt->to_server = TRUE;
4462 s->cur_prompt->name = dupstr("SSH password");
4463 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4464 ssh->username, ssh->savedhost),
4469 * Show password prompt, having first obtained it via a TIS
4470 * or CryptoCard exchange if we're doing TIS or CryptoCard
4474 int ret; /* need not be kept over crReturn */
4475 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4478 crWaitUntil(!pktin);
4479 ret = get_userpass_input(s->cur_prompt, in, inlen);
4484 * Failed to get a password (for example
4485 * because one was supplied on the command line
4486 * which has already failed to work). Terminate.
4488 free_prompts(s->cur_prompt);
4489 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4494 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4496 * Defence against traffic analysis: we send a
4497 * whole bunch of packets containing strings of
4498 * different lengths. One of these strings is the
4499 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4500 * The others are all random data in
4501 * SSH1_MSG_IGNORE packets. This way a passive
4502 * listener can't tell which is the password, and
4503 * hence can't deduce the password length.
4505 * Anybody with a password length greater than 16
4506 * bytes is going to have enough entropy in their
4507 * password that a listener won't find it _that_
4508 * much help to know how long it is. So what we'll
4511 * - if password length < 16, we send 15 packets
4512 * containing string lengths 1 through 15
4514 * - otherwise, we let N be the nearest multiple
4515 * of 8 below the password length, and send 8
4516 * packets containing string lengths N through
4517 * N+7. This won't obscure the order of
4518 * magnitude of the password length, but it will
4519 * introduce a bit of extra uncertainty.
4521 * A few servers can't deal with SSH1_MSG_IGNORE, at
4522 * least in this context. For these servers, we need
4523 * an alternative defence. We make use of the fact
4524 * that the password is interpreted as a C string:
4525 * so we can append a NUL, then some random data.
4527 * A few servers can deal with neither SSH1_MSG_IGNORE
4528 * here _nor_ a padded password string.
4529 * For these servers we are left with no defences
4530 * against password length sniffing.
4532 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4533 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4535 * The server can deal with SSH1_MSG_IGNORE, so
4536 * we can use the primary defence.
4538 int bottom, top, pwlen, i;
4541 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4543 bottom = 0; /* zero length passwords are OK! :-) */
4546 bottom = pwlen & ~7;
4550 assert(pwlen >= bottom && pwlen <= top);
4552 randomstr = snewn(top + 1, char);
4554 for (i = bottom; i <= top; i++) {
4556 defer_packet(ssh, s->pwpkt_type,
4557 PKT_STR,s->cur_prompt->prompts[0]->result,
4560 for (j = 0; j < i; j++) {
4562 randomstr[j] = random_byte();
4563 } while (randomstr[j] == '\0');
4565 randomstr[i] = '\0';
4566 defer_packet(ssh, SSH1_MSG_IGNORE,
4567 PKT_STR, randomstr, PKT_END);
4570 logevent("Sending password with camouflage packets");
4571 ssh_pkt_defersend(ssh);
4574 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4576 * The server can't deal with SSH1_MSG_IGNORE
4577 * but can deal with padded passwords, so we
4578 * can use the secondary defence.
4584 len = strlen(s->cur_prompt->prompts[0]->result);
4585 if (len < sizeof(string)) {
4587 strcpy(string, s->cur_prompt->prompts[0]->result);
4588 len++; /* cover the zero byte */
4589 while (len < sizeof(string)) {
4590 string[len++] = (char) random_byte();
4593 ss = s->cur_prompt->prompts[0]->result;
4595 logevent("Sending length-padded password");
4596 send_packet(ssh, s->pwpkt_type,
4597 PKT_INT, len, PKT_DATA, ss, len,
4601 * The server is believed unable to cope with
4602 * any of our password camouflage methods.
4605 len = strlen(s->cur_prompt->prompts[0]->result);
4606 logevent("Sending unpadded password");
4607 send_packet(ssh, s->pwpkt_type,
4609 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4613 send_packet(ssh, s->pwpkt_type,
4614 PKT_STR, s->cur_prompt->prompts[0]->result,
4617 logevent("Sent password");
4618 free_prompts(s->cur_prompt);
4620 if (pktin->type == SSH1_SMSG_FAILURE) {
4621 if (flags & FLAG_VERBOSE)
4622 c_write_str(ssh, "Access denied\r\n");
4623 logevent("Authentication refused");
4624 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4625 bombout(("Strange packet received, type %d", pktin->type));
4631 if (s->publickey_blob) {
4632 sfree(s->publickey_blob);
4633 sfree(s->publickey_comment);
4636 logevent("Authentication successful");
4641 static void ssh_channel_try_eof(struct ssh_channel *c)
4644 assert(c->pending_eof); /* precondition for calling us */
4646 return; /* can't close: not even opened yet */
4647 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4648 return; /* can't send EOF: pending outgoing data */
4650 c->pending_eof = FALSE; /* we're about to send it */
4651 if (ssh->version == 1) {
4652 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4654 c->closes |= CLOSES_SENT_EOF;
4656 struct Packet *pktout;
4657 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4658 ssh2_pkt_adduint32(pktout, c->remoteid);
4659 ssh2_pkt_send(ssh, pktout);
4660 c->closes |= CLOSES_SENT_EOF;
4661 ssh2_channel_check_close(c);
4665 Conf *sshfwd_get_conf(struct ssh_channel *c)
4671 void sshfwd_write_eof(struct ssh_channel *c)
4675 if (ssh->state == SSH_STATE_CLOSED)
4678 if (c->closes & CLOSES_SENT_EOF)
4681 c->pending_eof = TRUE;
4682 ssh_channel_try_eof(c);
4685 void sshfwd_unclean_close(struct ssh_channel *c, const char *err)
4689 if (ssh->state == SSH_STATE_CLOSED)
4694 x11_close(c->u.x11.xconn);
4695 logeventf(ssh, "Forwarded X11 connection terminated due to local "
4699 case CHAN_SOCKDATA_DORMANT:
4700 pfd_close(c->u.pfd.pf);
4701 logeventf(ssh, "Forwarded port closed due to local error: %s", err);
4704 c->type = CHAN_ZOMBIE;
4705 c->pending_eof = FALSE; /* this will confuse a zombie channel */
4707 ssh2_channel_check_close(c);
4710 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
4714 if (ssh->state == SSH_STATE_CLOSED)
4717 if (ssh->version == 1) {
4718 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
4719 PKT_INT, c->remoteid,
4720 PKT_INT, len, PKT_DATA, buf, len,
4723 * In SSH-1 we can return 0 here - implying that forwarded
4724 * connections are never individually throttled - because
4725 * the only circumstance that can cause throttling will be
4726 * the whole SSH connection backing up, in which case
4727 * _everything_ will be throttled as a whole.
4731 ssh2_add_channel_data(c, buf, len);
4732 return ssh2_try_send(c);
4736 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4741 if (ssh->state == SSH_STATE_CLOSED)
4744 if (ssh->version == 1) {
4745 buflimit = SSH1_BUFFER_LIMIT;
4747 buflimit = c->v.v2.locmaxwin;
4748 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
4750 if (c->throttling_conn && bufsize <= buflimit) {
4751 c->throttling_conn = 0;
4752 ssh_throttle_conn(ssh, -1);
4756 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
4758 struct queued_handler *qh = ssh->qhead;
4762 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
4765 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
4766 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
4769 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
4770 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
4774 ssh->qhead = qh->next;
4776 if (ssh->qhead->msg1 > 0) {
4777 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4778 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
4780 if (ssh->qhead->msg2 > 0) {
4781 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4782 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
4785 ssh->qhead = ssh->qtail = NULL;
4788 qh->handler(ssh, pktin, qh->ctx);
4793 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
4794 chandler_fn_t handler, void *ctx)
4796 struct queued_handler *qh;
4798 qh = snew(struct queued_handler);
4801 qh->handler = handler;
4805 if (ssh->qtail == NULL) {
4809 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4810 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
4813 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4814 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
4817 ssh->qtail->next = qh;
4822 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
4824 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
4826 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
4827 SSH2_MSG_REQUEST_SUCCESS)) {
4828 logeventf(ssh, "Remote port forwarding from %s enabled",
4831 logeventf(ssh, "Remote port forwarding from %s refused",
4834 rpf = del234(ssh->rportfwds, pf);
4836 pf->pfrec->remote = NULL;
4841 int ssh_alloc_sharing_rportfwd(Ssh ssh, const char *shost, int sport,
4844 struct ssh_rportfwd *pf = snew(struct ssh_rportfwd);
4847 pf->share_ctx = share_ctx;
4848 pf->shost = dupstr(shost);
4850 pf->sportdesc = NULL;
4851 if (!ssh->rportfwds) {
4852 assert(ssh->version == 2);
4853 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4855 if (add234(ssh->rportfwds, pf) != pf) {
4863 static void ssh_sharing_global_request_response(Ssh ssh, struct Packet *pktin,
4866 share_got_pkt_from_server(ctx, pktin->type,
4867 pktin->body, pktin->length);
4870 void ssh_sharing_queue_global_request(Ssh ssh, void *share_ctx)
4872 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, SSH2_MSG_REQUEST_FAILURE,
4873 ssh_sharing_global_request_response, share_ctx);
4876 static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
4878 struct ssh_portfwd *epf;
4882 if (!ssh->portfwds) {
4883 ssh->portfwds = newtree234(ssh_portcmp);
4886 * Go through the existing port forwardings and tag them
4887 * with status==DESTROY. Any that we want to keep will be
4888 * re-enabled (status==KEEP) as we go through the
4889 * configuration and find out which bits are the same as
4892 struct ssh_portfwd *epf;
4894 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4895 epf->status = DESTROY;
4898 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
4900 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
4901 char *kp, *kp2, *vp, *vp2;
4902 char address_family, type;
4903 int sport,dport,sserv,dserv;
4904 char *sports, *dports, *saddr, *host;
4908 address_family = 'A';
4910 if (*kp == 'A' || *kp == '4' || *kp == '6')
4911 address_family = *kp++;
4912 if (*kp == 'L' || *kp == 'R')
4915 if ((kp2 = strchr(kp, ':')) != NULL) {
4917 * There's a colon in the middle of the source port
4918 * string, which means that the part before it is
4919 * actually a source address.
4921 saddr = dupprintf("%.*s", (int)(kp2 - kp), kp);
4927 sport = atoi(sports);
4931 sport = net_service_lookup(sports);
4933 logeventf(ssh, "Service lookup failed for source"
4934 " port \"%s\"", sports);
4938 if (type == 'L' && !strcmp(val, "D")) {
4939 /* dynamic forwarding */
4946 /* ordinary forwarding */
4948 vp2 = vp + strcspn(vp, ":");
4949 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
4953 dport = atoi(dports);
4957 dport = net_service_lookup(dports);
4959 logeventf(ssh, "Service lookup failed for destination"
4960 " port \"%s\"", dports);
4965 if (sport && dport) {
4966 /* Set up a description of the source port. */
4967 struct ssh_portfwd *pfrec, *epfrec;
4969 pfrec = snew(struct ssh_portfwd);
4971 pfrec->saddr = saddr;
4972 pfrec->sserv = sserv ? dupstr(sports) : NULL;
4973 pfrec->sport = sport;
4974 pfrec->daddr = host;
4975 pfrec->dserv = dserv ? dupstr(dports) : NULL;
4976 pfrec->dport = dport;
4977 pfrec->local = NULL;
4978 pfrec->remote = NULL;
4979 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
4980 address_family == '6' ? ADDRTYPE_IPV6 :
4983 epfrec = add234(ssh->portfwds, pfrec);
4984 if (epfrec != pfrec) {
4985 if (epfrec->status == DESTROY) {
4987 * We already have a port forwarding up and running
4988 * with precisely these parameters. Hence, no need
4989 * to do anything; simply re-tag the existing one
4992 epfrec->status = KEEP;
4995 * Anything else indicates that there was a duplicate
4996 * in our input, which we'll silently ignore.
4998 free_portfwd(pfrec);
5000 pfrec->status = CREATE;
5009 * Now go through and destroy any port forwardings which were
5012 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5013 if (epf->status == DESTROY) {
5016 message = dupprintf("%s port forwarding from %s%s%d",
5017 epf->type == 'L' ? "local" :
5018 epf->type == 'R' ? "remote" : "dynamic",
5019 epf->saddr ? epf->saddr : "",
5020 epf->saddr ? ":" : "",
5023 if (epf->type != 'D') {
5024 char *msg2 = dupprintf("%s to %s:%d", message,
5025 epf->daddr, epf->dport);
5030 logeventf(ssh, "Cancelling %s", message);
5033 /* epf->remote or epf->local may be NULL if setting up a
5034 * forwarding failed. */
5036 struct ssh_rportfwd *rpf = epf->remote;
5037 struct Packet *pktout;
5040 * Cancel the port forwarding at the server
5043 if (ssh->version == 1) {
5045 * We cannot cancel listening ports on the
5046 * server side in SSH-1! There's no message
5047 * to support it. Instead, we simply remove
5048 * the rportfwd record from the local end
5049 * so that any connections the server tries
5050 * to make on it are rejected.
5053 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5054 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
5055 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
5057 ssh2_pkt_addstring(pktout, epf->saddr);
5058 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5059 /* XXX: rport_acceptall may not represent
5060 * what was used to open the original connection,
5061 * since it's reconfigurable. */
5062 ssh2_pkt_addstring(pktout, "");
5064 ssh2_pkt_addstring(pktout, "localhost");
5066 ssh2_pkt_adduint32(pktout, epf->sport);
5067 ssh2_pkt_send(ssh, pktout);
5070 del234(ssh->rportfwds, rpf);
5072 } else if (epf->local) {
5073 pfl_terminate(epf->local);
5076 delpos234(ssh->portfwds, i);
5078 i--; /* so we don't skip one in the list */
5082 * And finally, set up any new port forwardings (status==CREATE).
5084 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5085 if (epf->status == CREATE) {
5086 char *sportdesc, *dportdesc;
5087 sportdesc = dupprintf("%s%s%s%s%d%s",
5088 epf->saddr ? epf->saddr : "",
5089 epf->saddr ? ":" : "",
5090 epf->sserv ? epf->sserv : "",
5091 epf->sserv ? "(" : "",
5093 epf->sserv ? ")" : "");
5094 if (epf->type == 'D') {
5097 dportdesc = dupprintf("%s:%s%s%d%s",
5099 epf->dserv ? epf->dserv : "",
5100 epf->dserv ? "(" : "",
5102 epf->dserv ? ")" : "");
5105 if (epf->type == 'L') {
5106 char *err = pfl_listen(epf->daddr, epf->dport,
5107 epf->saddr, epf->sport,
5108 ssh, conf, &epf->local,
5109 epf->addressfamily);
5111 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
5112 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5113 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5114 sportdesc, dportdesc,
5115 err ? " failed: " : "", err ? err : "");
5118 } else if (epf->type == 'D') {
5119 char *err = pfl_listen(NULL, -1, epf->saddr, epf->sport,
5120 ssh, conf, &epf->local,
5121 epf->addressfamily);
5123 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
5124 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5125 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5127 err ? " failed: " : "", err ? err : "");
5132 struct ssh_rportfwd *pf;
5135 * Ensure the remote port forwardings tree exists.
5137 if (!ssh->rportfwds) {
5138 if (ssh->version == 1)
5139 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
5141 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5144 pf = snew(struct ssh_rportfwd);
5145 pf->share_ctx = NULL;
5146 pf->dhost = dupstr(epf->daddr);
5147 pf->dport = epf->dport;
5149 pf->shost = dupstr(epf->saddr);
5150 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5151 pf->shost = dupstr("");
5153 pf->shost = dupstr("localhost");
5155 pf->sport = epf->sport;
5156 if (add234(ssh->rportfwds, pf) != pf) {
5157 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
5158 epf->daddr, epf->dport);
5161 logeventf(ssh, "Requesting remote port %s"
5162 " forward to %s", sportdesc, dportdesc);
5164 pf->sportdesc = sportdesc;
5169 if (ssh->version == 1) {
5170 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
5171 PKT_INT, epf->sport,
5172 PKT_STR, epf->daddr,
5173 PKT_INT, epf->dport,
5175 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
5177 ssh_rportfwd_succfail, pf);
5179 struct Packet *pktout;
5180 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5181 ssh2_pkt_addstring(pktout, "tcpip-forward");
5182 ssh2_pkt_addbool(pktout, 1);/* want reply */
5183 ssh2_pkt_addstring(pktout, pf->shost);
5184 ssh2_pkt_adduint32(pktout, pf->sport);
5185 ssh2_pkt_send(ssh, pktout);
5187 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
5188 SSH2_MSG_REQUEST_FAILURE,
5189 ssh_rportfwd_succfail, pf);
5198 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
5201 int stringlen, bufsize;
5203 ssh_pkt_getstring(pktin, &string, &stringlen);
5204 if (string == NULL) {
5205 bombout(("Incoming terminal data packet was badly formed"));
5209 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
5211 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
5212 ssh->v1_stdout_throttling = 1;
5213 ssh_throttle_conn(ssh, +1);
5217 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
5219 /* Remote side is trying to open a channel to talk to our
5220 * X-Server. Give them back a local channel number. */
5221 struct ssh_channel *c;
5222 int remoteid = ssh_pkt_getuint32(pktin);
5224 logevent("Received X11 connect request");
5225 /* Refuse if X11 forwarding is disabled. */
5226 if (!ssh->X11_fwd_enabled) {
5227 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5228 PKT_INT, remoteid, PKT_END);
5229 logevent("Rejected X11 connect request");
5231 c = snew(struct ssh_channel);
5234 c->u.x11.xconn = x11_init(ssh->x11authtree, c, NULL, -1);
5235 c->remoteid = remoteid;
5236 c->halfopen = FALSE;
5237 c->localid = alloc_channel_id(ssh);
5239 c->pending_eof = FALSE;
5240 c->throttling_conn = 0;
5241 c->type = CHAN_X11; /* identify channel type */
5242 add234(ssh->channels, c);
5243 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5244 PKT_INT, c->remoteid, PKT_INT,
5245 c->localid, PKT_END);
5246 logevent("Opened X11 forward channel");
5250 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
5252 /* Remote side is trying to open a channel to talk to our
5253 * agent. Give them back a local channel number. */
5254 struct ssh_channel *c;
5255 int remoteid = ssh_pkt_getuint32(pktin);
5257 /* Refuse if agent forwarding is disabled. */
5258 if (!ssh->agentfwd_enabled) {
5259 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5260 PKT_INT, remoteid, PKT_END);
5262 c = snew(struct ssh_channel);
5264 c->remoteid = remoteid;
5265 c->halfopen = FALSE;
5266 c->localid = alloc_channel_id(ssh);
5268 c->pending_eof = FALSE;
5269 c->throttling_conn = 0;
5270 c->type = CHAN_AGENT; /* identify channel type */
5271 c->u.a.lensofar = 0;
5272 c->u.a.message = NULL;
5273 c->u.a.outstanding_requests = 0;
5274 add234(ssh->channels, c);
5275 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5276 PKT_INT, c->remoteid, PKT_INT, c->localid,
5281 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
5283 /* Remote side is trying to open a channel to talk to a
5284 * forwarded port. Give them back a local channel number. */
5285 struct ssh_rportfwd pf, *pfp;
5291 remoteid = ssh_pkt_getuint32(pktin);
5292 ssh_pkt_getstring(pktin, &host, &hostsize);
5293 port = ssh_pkt_getuint32(pktin);
5295 pf.dhost = dupprintf("%.*s", hostsize, host);
5297 pfp = find234(ssh->rportfwds, &pf, NULL);
5300 logeventf(ssh, "Rejected remote port open request for %s:%d",
5302 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5303 PKT_INT, remoteid, PKT_END);
5305 struct ssh_channel *c = snew(struct ssh_channel);
5308 logeventf(ssh, "Received remote port open request for %s:%d",
5310 err = pfd_connect(&c->u.pfd.pf, pf.dhost, port,
5311 c, ssh->conf, pfp->pfrec->addressfamily);
5313 logeventf(ssh, "Port open failed: %s", err);
5316 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5317 PKT_INT, remoteid, PKT_END);
5319 c->remoteid = remoteid;
5320 c->halfopen = FALSE;
5321 c->localid = alloc_channel_id(ssh);
5323 c->pending_eof = FALSE;
5324 c->throttling_conn = 0;
5325 c->type = CHAN_SOCKDATA; /* identify channel type */
5326 add234(ssh->channels, c);
5327 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5328 PKT_INT, c->remoteid, PKT_INT,
5329 c->localid, PKT_END);
5330 logevent("Forwarded port opened successfully");
5337 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5339 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5340 unsigned int localid = ssh_pkt_getuint32(pktin);
5341 struct ssh_channel *c;
5343 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5344 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5345 c->remoteid = localid;
5346 c->halfopen = FALSE;
5347 c->type = CHAN_SOCKDATA;
5348 c->throttling_conn = 0;
5349 pfd_confirm(c->u.pfd.pf);
5352 if (c && c->pending_eof) {
5354 * We have a pending close on this channel,
5355 * which we decided on before the server acked
5356 * the channel open. So now we know the
5357 * remoteid, we can close it again.
5359 ssh_channel_try_eof(c);
5363 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5365 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5366 struct ssh_channel *c;
5368 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5369 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5370 logevent("Forwarded connection refused by server");
5371 pfd_close(c->u.pfd.pf);
5372 del234(ssh->channels, c);
5377 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
5379 /* Remote side closes a channel. */
5380 unsigned i = ssh_pkt_getuint32(pktin);
5381 struct ssh_channel *c;
5382 c = find234(ssh->channels, &i, ssh_channelfind);
5383 if (c && !c->halfopen) {
5385 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
5386 !(c->closes & CLOSES_RCVD_EOF)) {
5388 * Received CHANNEL_CLOSE, which we translate into
5391 int send_close = FALSE;
5393 c->closes |= CLOSES_RCVD_EOF;
5398 x11_send_eof(c->u.x11.xconn);
5404 pfd_send_eof(c->u.pfd.pf);
5413 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
5414 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
5416 c->closes |= CLOSES_SENT_EOF;
5420 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
5421 !(c->closes & CLOSES_RCVD_CLOSE)) {
5423 if (!(c->closes & CLOSES_SENT_EOF)) {
5424 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
5425 " for which we never sent CHANNEL_CLOSE\n", i));
5428 c->closes |= CLOSES_RCVD_CLOSE;
5431 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
5432 !(c->closes & CLOSES_SENT_CLOSE)) {
5433 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
5434 PKT_INT, c->remoteid, PKT_END);
5435 c->closes |= CLOSES_SENT_CLOSE;
5438 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5439 ssh_channel_destroy(c);
5441 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5442 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
5443 "_CONFIRMATION", c ? "half-open" : "nonexistent",
5448 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5450 /* Data sent down one of our channels. */
5451 int i = ssh_pkt_getuint32(pktin);
5454 struct ssh_channel *c;
5456 ssh_pkt_getstring(pktin, &p, &len);
5458 c = find234(ssh->channels, &i, ssh_channelfind);
5463 bufsize = x11_send(c->u.x11.xconn, p, len);
5466 bufsize = pfd_send(c->u.pfd.pf, p, len);
5469 /* Data for an agent message. Buffer it. */
5471 if (c->u.a.lensofar < 4) {
5472 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
5473 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
5477 c->u.a.lensofar += l;
5479 if (c->u.a.lensofar == 4) {
5481 4 + GET_32BIT(c->u.a.msglen);
5482 c->u.a.message = snewn(c->u.a.totallen,
5484 memcpy(c->u.a.message, c->u.a.msglen, 4);
5486 if (c->u.a.lensofar >= 4 && len > 0) {
5488 min(c->u.a.totallen - c->u.a.lensofar,
5490 memcpy(c->u.a.message + c->u.a.lensofar, p,
5494 c->u.a.lensofar += l;
5496 if (c->u.a.lensofar == c->u.a.totallen) {
5499 c->u.a.outstanding_requests++;
5500 if (agent_query(c->u.a.message,
5503 ssh_agentf_callback, c))
5504 ssh_agentf_callback(c, reply, replylen);
5505 sfree(c->u.a.message);
5506 c->u.a.lensofar = 0;
5509 bufsize = 0; /* agent channels never back up */
5512 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5513 c->throttling_conn = 1;
5514 ssh_throttle_conn(ssh, +1);
5519 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5521 ssh->exitcode = ssh_pkt_getuint32(pktin);
5522 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5523 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5525 * In case `helpful' firewalls or proxies tack
5526 * extra human-readable text on the end of the
5527 * session which we might mistake for another
5528 * encrypted packet, we close the session once
5529 * we've sent EXIT_CONFIRMATION.
5531 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5534 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5535 static void ssh1_send_ttymode(void *data, char *mode, char *val)
5537 struct Packet *pktout = (struct Packet *)data;
5539 unsigned int arg = 0;
5540 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5541 if (i == lenof(ssh_ttymodes)) return;
5542 switch (ssh_ttymodes[i].type) {
5544 arg = ssh_tty_parse_specchar(val);
5547 arg = ssh_tty_parse_boolean(val);
5550 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5551 ssh2_pkt_addbyte(pktout, arg);
5554 int ssh_agent_forwarding_permitted(Ssh ssh)
5556 return conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists();
5559 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
5560 struct Packet *pktin)
5562 crBegin(ssh->do_ssh1_connection_crstate);
5564 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5565 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5566 ssh1_smsg_stdout_stderr_data;
5568 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5569 ssh1_msg_channel_open_confirmation;
5570 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5571 ssh1_msg_channel_open_failure;
5572 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5573 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5574 ssh1_msg_channel_close;
5575 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5576 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5578 if (ssh_agent_forwarding_permitted(ssh)) {
5579 logevent("Requesting agent forwarding");
5580 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5584 if (pktin->type != SSH1_SMSG_SUCCESS
5585 && pktin->type != SSH1_SMSG_FAILURE) {
5586 bombout(("Protocol confusion"));
5588 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5589 logevent("Agent forwarding refused");
5591 logevent("Agent forwarding enabled");
5592 ssh->agentfwd_enabled = TRUE;
5593 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5597 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
5599 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5601 if (!ssh->x11disp) {
5602 /* FIXME: return an error message from x11_setup_display */
5603 logevent("X11 forwarding not enabled: unable to"
5604 " initialise X display");
5606 ssh->x11auth = x11_invent_fake_auth
5607 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
5608 ssh->x11auth->disp = ssh->x11disp;
5610 logevent("Requesting X11 forwarding");
5611 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5612 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5613 PKT_STR, ssh->x11auth->protoname,
5614 PKT_STR, ssh->x11auth->datastring,
5615 PKT_INT, ssh->x11disp->screennum,
5618 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5619 PKT_STR, ssh->x11auth->protoname,
5620 PKT_STR, ssh->x11auth->datastring,
5626 if (pktin->type != SSH1_SMSG_SUCCESS
5627 && pktin->type != SSH1_SMSG_FAILURE) {
5628 bombout(("Protocol confusion"));
5630 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5631 logevent("X11 forwarding refused");
5633 logevent("X11 forwarding enabled");
5634 ssh->X11_fwd_enabled = TRUE;
5635 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5640 ssh_setup_portfwd(ssh, ssh->conf);
5641 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5643 if (!conf_get_int(ssh->conf, CONF_nopty)) {
5645 /* Unpick the terminal-speed string. */
5646 /* XXX perhaps we should allow no speeds to be sent. */
5647 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5648 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
5649 /* Send the pty request. */
5650 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5651 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
5652 ssh_pkt_adduint32(pkt, ssh->term_height);
5653 ssh_pkt_adduint32(pkt, ssh->term_width);
5654 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5655 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5656 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
5657 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5658 ssh_pkt_adduint32(pkt, ssh->ispeed);
5659 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5660 ssh_pkt_adduint32(pkt, ssh->ospeed);
5661 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5663 ssh->state = SSH_STATE_INTERMED;
5667 if (pktin->type != SSH1_SMSG_SUCCESS
5668 && pktin->type != SSH1_SMSG_FAILURE) {
5669 bombout(("Protocol confusion"));
5671 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5672 c_write_str(ssh, "Server refused to allocate pty\r\n");
5673 ssh->editing = ssh->echoing = 1;
5675 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5676 ssh->ospeed, ssh->ispeed);
5677 ssh->got_pty = TRUE;
5680 ssh->editing = ssh->echoing = 1;
5683 if (conf_get_int(ssh->conf, CONF_compression)) {
5684 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5688 if (pktin->type != SSH1_SMSG_SUCCESS
5689 && pktin->type != SSH1_SMSG_FAILURE) {
5690 bombout(("Protocol confusion"));
5692 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5693 c_write_str(ssh, "Server refused to compress\r\n");
5695 logevent("Started compression");
5696 ssh->v1_compressing = TRUE;
5697 ssh->cs_comp_ctx = zlib_compress_init();
5698 logevent("Initialised zlib (RFC1950) compression");
5699 ssh->sc_comp_ctx = zlib_decompress_init();
5700 logevent("Initialised zlib (RFC1950) decompression");
5704 * Start the shell or command.
5706 * Special case: if the first-choice command is an SSH-2
5707 * subsystem (hence not usable here) and the second choice
5708 * exists, we fall straight back to that.
5711 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
5713 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
5714 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
5715 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
5716 ssh->fallback_cmd = TRUE;
5719 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
5721 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
5722 logevent("Started session");
5725 ssh->state = SSH_STATE_SESSION;
5726 if (ssh->size_needed)
5727 ssh_size(ssh, ssh->term_width, ssh->term_height);
5728 if (ssh->eof_needed)
5729 ssh_special(ssh, TS_EOF);
5732 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5734 ssh->channels = newtree234(ssh_channelcmp);
5738 * By this point, most incoming packets are already being
5739 * handled by the dispatch table, and we need only pay
5740 * attention to the unusual ones.
5745 if (pktin->type == SSH1_SMSG_SUCCESS) {
5746 /* may be from EXEC_SHELL on some servers */
5747 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5748 /* may be from EXEC_SHELL on some servers
5749 * if no pty is available or in other odd cases. Ignore */
5751 bombout(("Strange packet received: type %d", pktin->type));
5756 int len = min(inlen, 512);
5757 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
5758 PKT_INT, len, PKT_DATA, in, len,
5770 * Handle the top-level SSH-2 protocol.
5772 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
5777 ssh_pkt_getstring(pktin, &msg, &msglen);
5778 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
5781 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
5783 /* log reason code in disconnect message */
5787 ssh_pkt_getstring(pktin, &msg, &msglen);
5788 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
5791 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
5793 /* Do nothing, because we're ignoring it! Duhh. */
5796 static void ssh1_protocol_setup(Ssh ssh)
5801 * Most messages are handled by the coroutines.
5803 for (i = 0; i < 256; i++)
5804 ssh->packet_dispatch[i] = NULL;
5807 * These special message types we install handlers for.
5809 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
5810 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
5811 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
5814 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
5815 struct Packet *pktin)
5817 unsigned char *in=(unsigned char*)vin;
5818 if (ssh->state == SSH_STATE_CLOSED)
5821 if (pktin && ssh->packet_dispatch[pktin->type]) {
5822 ssh->packet_dispatch[pktin->type](ssh, pktin);
5826 if (!ssh->protocol_initial_phase_done) {
5827 if (do_ssh1_login(ssh, in, inlen, pktin))
5828 ssh->protocol_initial_phase_done = TRUE;
5833 do_ssh1_connection(ssh, in, inlen, pktin);
5837 * Utility routine for decoding comma-separated strings in KEXINIT.
5839 static int in_commasep_string(char *needle, char *haystack, int haylen)
5842 if (!needle || !haystack) /* protect against null pointers */
5844 needlen = strlen(needle);
5847 * Is it at the start of the string?
5849 if (haylen >= needlen && /* haystack is long enough */
5850 !memcmp(needle, haystack, needlen) && /* initial match */
5851 (haylen == needlen || haystack[needlen] == ',')
5852 /* either , or EOS follows */
5856 * If not, search for the next comma and resume after that.
5857 * If no comma found, terminate.
5859 while (haylen > 0 && *haystack != ',')
5860 haylen--, haystack++;
5863 haylen--, haystack++; /* skip over comma itself */
5868 * Similar routine for checking whether we have the first string in a list.
5870 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
5873 if (!needle || !haystack) /* protect against null pointers */
5875 needlen = strlen(needle);
5877 * Is it at the start of the string?
5879 if (haylen >= needlen && /* haystack is long enough */
5880 !memcmp(needle, haystack, needlen) && /* initial match */
5881 (haylen == needlen || haystack[needlen] == ',')
5882 /* either , or EOS follows */
5890 * SSH-2 key creation method.
5891 * (Currently assumes 2 lots of any hash are sufficient to generate
5892 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
5894 #define SSH2_MKKEY_ITERS (2)
5895 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
5896 unsigned char *keyspace)
5898 const struct ssh_hash *h = ssh->kex->hash;
5900 /* First hlen bytes. */
5902 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5903 hash_mpint(h, s, K);
5904 h->bytes(s, H, h->hlen);
5905 h->bytes(s, &chr, 1);
5906 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
5907 h->final(s, keyspace);
5908 /* Next hlen bytes. */
5910 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5911 hash_mpint(h, s, K);
5912 h->bytes(s, H, h->hlen);
5913 h->bytes(s, keyspace, h->hlen);
5914 h->final(s, keyspace + h->hlen);
5918 * Handle the SSH-2 transport layer.
5920 static void do_ssh2_transport(Ssh ssh, void *vin, int inlen,
5921 struct Packet *pktin)
5923 unsigned char *in = (unsigned char *)vin;
5924 struct do_ssh2_transport_state {
5926 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
5927 Bignum p, g, e, f, K;
5930 int kex_init_value, kex_reply_value;
5931 const struct ssh_mac **maclist;
5933 const struct ssh2_cipher *cscipher_tobe;
5934 const struct ssh2_cipher *sccipher_tobe;
5935 const struct ssh_mac *csmac_tobe;
5936 const struct ssh_mac *scmac_tobe;
5937 const struct ssh_compress *cscomp_tobe;
5938 const struct ssh_compress *sccomp_tobe;
5939 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
5940 int hostkeylen, siglen, rsakeylen;
5941 void *hkey; /* actual host key */
5942 void *rsakey; /* for RSA kex */
5943 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
5944 int n_preferred_kex;
5945 const struct ssh_kexes *preferred_kex[KEX_MAX];
5946 int n_preferred_ciphers;
5947 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
5948 const struct ssh_compress *preferred_comp;
5949 int userauth_succeeded; /* for delayed compression */
5950 int pending_compression;
5951 int got_session_id, activated_authconn;
5952 struct Packet *pktout;
5957 crState(do_ssh2_transport_state);
5959 assert(!ssh->bare_connection);
5963 s->cscipher_tobe = s->sccipher_tobe = NULL;
5964 s->csmac_tobe = s->scmac_tobe = NULL;
5965 s->cscomp_tobe = s->sccomp_tobe = NULL;
5967 s->got_session_id = s->activated_authconn = FALSE;
5968 s->userauth_succeeded = FALSE;
5969 s->pending_compression = FALSE;
5972 * Be prepared to work around the buggy MAC problem.
5974 if (ssh->remote_bugs & BUG_SSH2_HMAC)
5975 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
5977 s->maclist = macs, s->nmacs = lenof(macs);
5980 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
5982 int i, j, k, commalist_started;
5985 * Set up the preferred key exchange. (NULL => warn below here)
5987 s->n_preferred_kex = 0;
5988 for (i = 0; i < KEX_MAX; i++) {
5989 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
5991 s->preferred_kex[s->n_preferred_kex++] =
5992 &ssh_diffiehellman_gex;
5995 s->preferred_kex[s->n_preferred_kex++] =
5996 &ssh_diffiehellman_group14;
5999 s->preferred_kex[s->n_preferred_kex++] =
6000 &ssh_diffiehellman_group1;
6003 s->preferred_kex[s->n_preferred_kex++] =
6007 /* Flag for later. Don't bother if it's the last in
6009 if (i < KEX_MAX - 1) {
6010 s->preferred_kex[s->n_preferred_kex++] = NULL;
6017 * Set up the preferred ciphers. (NULL => warn below here)
6019 s->n_preferred_ciphers = 0;
6020 for (i = 0; i < CIPHER_MAX; i++) {
6021 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
6022 case CIPHER_BLOWFISH:
6023 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
6026 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
6027 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
6031 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
6034 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
6036 case CIPHER_ARCFOUR:
6037 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
6040 /* Flag for later. Don't bother if it's the last in
6042 if (i < CIPHER_MAX - 1) {
6043 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
6050 * Set up preferred compression.
6052 if (conf_get_int(ssh->conf, CONF_compression))
6053 s->preferred_comp = &ssh_zlib;
6055 s->preferred_comp = &ssh_comp_none;
6058 * Enable queueing of outgoing auth- or connection-layer
6059 * packets while we are in the middle of a key exchange.
6061 ssh->queueing = TRUE;
6064 * Flag that KEX is in progress.
6066 ssh->kex_in_progress = TRUE;
6069 * Construct and send our key exchange packet.
6071 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
6072 for (i = 0; i < 16; i++)
6073 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
6074 /* List key exchange algorithms. */
6075 ssh2_pkt_addstring_start(s->pktout);
6076 commalist_started = 0;
6077 for (i = 0; i < s->n_preferred_kex; i++) {
6078 const struct ssh_kexes *k = s->preferred_kex[i];
6079 if (!k) continue; /* warning flag */
6080 for (j = 0; j < k->nkexes; j++) {
6081 if (commalist_started)
6082 ssh2_pkt_addstring_str(s->pktout, ",");
6083 ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
6084 commalist_started = 1;
6087 /* List server host key algorithms. */
6088 if (!s->got_session_id) {
6090 * In the first key exchange, we list all the algorithms
6091 * we're prepared to cope with.
6093 ssh2_pkt_addstring_start(s->pktout);
6094 for (i = 0; i < lenof(hostkey_algs); i++) {
6095 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
6096 if (i < lenof(hostkey_algs) - 1)
6097 ssh2_pkt_addstring_str(s->pktout, ",");
6101 * In subsequent key exchanges, we list only the kex
6102 * algorithm that was selected in the first key exchange,
6103 * so that we keep getting the same host key and hence
6104 * don't have to interrupt the user's session to ask for
6108 ssh2_pkt_addstring(s->pktout, ssh->hostkey->name);
6110 /* List encryption algorithms (client->server then server->client). */
6111 for (k = 0; k < 2; k++) {
6112 ssh2_pkt_addstring_start(s->pktout);
6113 commalist_started = 0;
6114 for (i = 0; i < s->n_preferred_ciphers; i++) {
6115 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6116 if (!c) continue; /* warning flag */
6117 for (j = 0; j < c->nciphers; j++) {
6118 if (commalist_started)
6119 ssh2_pkt_addstring_str(s->pktout, ",");
6120 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
6121 commalist_started = 1;
6125 /* List MAC algorithms (client->server then server->client). */
6126 for (j = 0; j < 2; j++) {
6127 ssh2_pkt_addstring_start(s->pktout);
6128 for (i = 0; i < s->nmacs; i++) {
6129 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
6130 if (i < s->nmacs - 1)
6131 ssh2_pkt_addstring_str(s->pktout, ",");
6134 /* List client->server compression algorithms,
6135 * then server->client compression algorithms. (We use the
6136 * same set twice.) */
6137 for (j = 0; j < 2; j++) {
6138 ssh2_pkt_addstring_start(s->pktout);
6139 assert(lenof(compressions) > 1);
6140 /* Prefer non-delayed versions */
6141 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
6142 /* We don't even list delayed versions of algorithms until
6143 * they're allowed to be used, to avoid a race. See the end of
6145 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
6146 ssh2_pkt_addstring_str(s->pktout, ",");
6147 ssh2_pkt_addstring_str(s->pktout,
6148 s->preferred_comp->delayed_name);
6150 for (i = 0; i < lenof(compressions); i++) {
6151 const struct ssh_compress *c = compressions[i];
6152 if (c != s->preferred_comp) {
6153 ssh2_pkt_addstring_str(s->pktout, ",");
6154 ssh2_pkt_addstring_str(s->pktout, c->name);
6155 if (s->userauth_succeeded && c->delayed_name) {
6156 ssh2_pkt_addstring_str(s->pktout, ",");
6157 ssh2_pkt_addstring_str(s->pktout, c->delayed_name);
6162 /* List client->server languages. Empty list. */
6163 ssh2_pkt_addstring_start(s->pktout);
6164 /* List server->client languages. Empty list. */
6165 ssh2_pkt_addstring_start(s->pktout);
6166 /* First KEX packet does _not_ follow, because we're not that brave. */
6167 ssh2_pkt_addbool(s->pktout, FALSE);
6169 ssh2_pkt_adduint32(s->pktout, 0);
6172 s->our_kexinitlen = s->pktout->length - 5;
6173 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
6174 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
6176 ssh2_pkt_send_noqueue(ssh, s->pktout);
6179 crWaitUntilV(pktin);
6182 * Now examine the other side's KEXINIT to see what we're up
6186 char *str, *preferred;
6189 if (pktin->type != SSH2_MSG_KEXINIT) {
6190 bombout(("expected key exchange packet from server"));
6194 ssh->hostkey = NULL;
6195 s->cscipher_tobe = NULL;
6196 s->sccipher_tobe = NULL;
6197 s->csmac_tobe = NULL;
6198 s->scmac_tobe = NULL;
6199 s->cscomp_tobe = NULL;
6200 s->sccomp_tobe = NULL;
6201 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
6203 pktin->savedpos += 16; /* skip garbage cookie */
6204 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
6207 for (i = 0; i < s->n_preferred_kex; i++) {
6208 const struct ssh_kexes *k = s->preferred_kex[i];
6212 for (j = 0; j < k->nkexes; j++) {
6213 if (!preferred) preferred = k->list[j]->name;
6214 if (in_commasep_string(k->list[j]->name, str, len)) {
6215 ssh->kex = k->list[j];
6224 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
6225 str ? str : "(null)"));
6229 * Note that the server's guess is considered wrong if it doesn't match
6230 * the first algorithm in our list, even if it's still the algorithm
6233 s->guessok = first_in_commasep_string(preferred, str, len);
6234 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
6235 for (i = 0; i < lenof(hostkey_algs); i++) {
6236 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
6237 ssh->hostkey = hostkey_algs[i];
6241 if (!ssh->hostkey) {
6242 bombout(("Couldn't agree a host key algorithm (available: %s)",
6243 str ? str : "(null)"));
6247 s->guessok = s->guessok &&
6248 first_in_commasep_string(hostkey_algs[0]->name, str, len);
6249 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
6250 for (i = 0; i < s->n_preferred_ciphers; i++) {
6251 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6253 s->warn_cscipher = TRUE;
6255 for (j = 0; j < c->nciphers; j++) {
6256 if (in_commasep_string(c->list[j]->name, str, len)) {
6257 s->cscipher_tobe = c->list[j];
6262 if (s->cscipher_tobe)
6265 if (!s->cscipher_tobe) {
6266 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
6267 str ? str : "(null)"));
6271 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
6272 for (i = 0; i < s->n_preferred_ciphers; i++) {
6273 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6275 s->warn_sccipher = TRUE;
6277 for (j = 0; j < c->nciphers; j++) {
6278 if (in_commasep_string(c->list[j]->name, str, len)) {
6279 s->sccipher_tobe = c->list[j];
6284 if (s->sccipher_tobe)
6287 if (!s->sccipher_tobe) {
6288 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
6289 str ? str : "(null)"));
6293 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
6294 for (i = 0; i < s->nmacs; i++) {
6295 if (in_commasep_string(s->maclist[i]->name, str, len)) {
6296 s->csmac_tobe = s->maclist[i];
6300 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
6301 for (i = 0; i < s->nmacs; i++) {
6302 if (in_commasep_string(s->maclist[i]->name, str, len)) {
6303 s->scmac_tobe = s->maclist[i];
6307 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
6308 for (i = 0; i < lenof(compressions) + 1; i++) {
6309 const struct ssh_compress *c =
6310 i == 0 ? s->preferred_comp : compressions[i - 1];
6311 if (in_commasep_string(c->name, str, len)) {
6314 } else if (in_commasep_string(c->delayed_name, str, len)) {
6315 if (s->userauth_succeeded) {
6319 s->pending_compression = TRUE; /* try this later */
6323 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
6324 for (i = 0; i < lenof(compressions) + 1; i++) {
6325 const struct ssh_compress *c =
6326 i == 0 ? s->preferred_comp : compressions[i - 1];
6327 if (in_commasep_string(c->name, str, len)) {
6330 } else if (in_commasep_string(c->delayed_name, str, len)) {
6331 if (s->userauth_succeeded) {
6335 s->pending_compression = TRUE; /* try this later */
6339 if (s->pending_compression) {
6340 logevent("Server supports delayed compression; "
6341 "will try this later");
6343 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
6344 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
6345 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
6347 ssh->exhash = ssh->kex->hash->init();
6348 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
6349 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
6350 hash_string(ssh->kex->hash, ssh->exhash,
6351 s->our_kexinit, s->our_kexinitlen);
6352 sfree(s->our_kexinit);
6353 /* Include the type byte in the hash of server's KEXINIT */
6354 hash_string(ssh->kex->hash, ssh->exhash,
6355 pktin->body - 1, pktin->length + 1);
6358 ssh_set_frozen(ssh, 1);
6359 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
6361 ssh_dialog_callback, ssh);
6362 if (s->dlgret < 0) {
6366 bombout(("Unexpected data from server while"
6367 " waiting for user response"));
6370 } while (pktin || inlen > 0);
6371 s->dlgret = ssh->user_response;
6373 ssh_set_frozen(ssh, 0);
6374 if (s->dlgret == 0) {
6375 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
6381 if (s->warn_cscipher) {
6382 ssh_set_frozen(ssh, 1);
6383 s->dlgret = askalg(ssh->frontend,
6384 "client-to-server cipher",
6385 s->cscipher_tobe->name,
6386 ssh_dialog_callback, ssh);
6387 if (s->dlgret < 0) {
6391 bombout(("Unexpected data from server while"
6392 " waiting for user response"));
6395 } while (pktin || inlen > 0);
6396 s->dlgret = ssh->user_response;
6398 ssh_set_frozen(ssh, 0);
6399 if (s->dlgret == 0) {
6400 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6406 if (s->warn_sccipher) {
6407 ssh_set_frozen(ssh, 1);
6408 s->dlgret = askalg(ssh->frontend,
6409 "server-to-client cipher",
6410 s->sccipher_tobe->name,
6411 ssh_dialog_callback, ssh);
6412 if (s->dlgret < 0) {
6416 bombout(("Unexpected data from server while"
6417 " waiting for user response"));
6420 } while (pktin || inlen > 0);
6421 s->dlgret = ssh->user_response;
6423 ssh_set_frozen(ssh, 0);
6424 if (s->dlgret == 0) {
6425 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6431 if (s->ignorepkt) /* first_kex_packet_follows */
6432 crWaitUntilV(pktin); /* Ignore packet */
6435 if (ssh->kex->main_type == KEXTYPE_DH) {
6437 * Work out the number of bits of key we will need from the
6438 * key exchange. We start with the maximum key length of
6444 csbits = s->cscipher_tobe->keylen;
6445 scbits = s->sccipher_tobe->keylen;
6446 s->nbits = (csbits > scbits ? csbits : scbits);
6448 /* The keys only have hlen-bit entropy, since they're based on
6449 * a hash. So cap the key size at hlen bits. */
6450 if (s->nbits > ssh->kex->hash->hlen * 8)
6451 s->nbits = ssh->kex->hash->hlen * 8;
6454 * If we're doing Diffie-Hellman group exchange, start by
6455 * requesting a group.
6457 if (!ssh->kex->pdata) {
6458 logevent("Doing Diffie-Hellman group exchange");
6459 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
6461 * Work out how big a DH group we will need to allow that
6464 s->pbits = 512 << ((s->nbits - 1) / 64);
6465 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6466 ssh2_pkt_adduint32(s->pktout, s->pbits);
6467 ssh2_pkt_send_noqueue(ssh, s->pktout);
6469 crWaitUntilV(pktin);
6470 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6471 bombout(("expected key exchange group packet from server"));
6474 s->p = ssh2_pkt_getmp(pktin);
6475 s->g = ssh2_pkt_getmp(pktin);
6476 if (!s->p || !s->g) {
6477 bombout(("unable to read mp-ints from incoming group packet"));
6480 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6481 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6482 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6484 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
6485 ssh->kex_ctx = dh_setup_group(ssh->kex);
6486 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6487 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6488 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6489 ssh->kex->groupname);
6492 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6493 ssh->kex->hash->text_name);
6495 * Now generate and send e for Diffie-Hellman.
6497 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6498 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6499 s->pktout = ssh2_pkt_init(s->kex_init_value);
6500 ssh2_pkt_addmp(s->pktout, s->e);
6501 ssh2_pkt_send_noqueue(ssh, s->pktout);
6503 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
6504 crWaitUntilV(pktin);
6505 if (pktin->type != s->kex_reply_value) {
6506 bombout(("expected key exchange reply packet from server"));
6509 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
6510 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6511 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6512 s->f = ssh2_pkt_getmp(pktin);
6514 bombout(("unable to parse key exchange reply packet"));
6517 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6519 s->K = dh_find_K(ssh->kex_ctx, s->f);
6521 /* We assume everything from now on will be quick, and it might
6522 * involve user interaction. */
6523 set_busy_status(ssh->frontend, BUSY_NOT);
6525 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6526 if (!ssh->kex->pdata) {
6527 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
6528 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
6529 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
6531 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
6532 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
6534 dh_cleanup(ssh->kex_ctx);
6536 if (!ssh->kex->pdata) {
6541 logeventf(ssh, "Doing RSA key exchange with hash %s",
6542 ssh->kex->hash->text_name);
6543 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
6545 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6548 crWaitUntilV(pktin);
6549 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
6550 bombout(("expected RSA public key packet from server"));
6554 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6555 hash_string(ssh->kex->hash, ssh->exhash,
6556 s->hostkeydata, s->hostkeylen);
6557 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6561 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
6562 s->rsakeydata = snewn(s->rsakeylen, char);
6563 memcpy(s->rsakeydata, keydata, s->rsakeylen);
6566 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
6568 sfree(s->rsakeydata);
6569 bombout(("unable to parse RSA public key from server"));
6573 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
6576 * Next, set up a shared secret K, of precisely KLEN -
6577 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6578 * RSA key modulus and HLEN is the bit length of the hash
6582 int klen = ssh_rsakex_klen(s->rsakey);
6583 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
6585 unsigned char *kstr1, *kstr2, *outstr;
6586 int kstr1len, kstr2len, outstrlen;
6588 s->K = bn_power_2(nbits - 1);
6590 for (i = 0; i < nbits; i++) {
6592 byte = random_byte();
6594 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
6598 * Encode this as an mpint.
6600 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
6601 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
6602 PUT_32BIT(kstr2, kstr1len);
6603 memcpy(kstr2 + 4, kstr1, kstr1len);
6606 * Encrypt it with the given RSA key.
6608 outstrlen = (klen + 7) / 8;
6609 outstr = snewn(outstrlen, unsigned char);
6610 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
6611 outstr, outstrlen, s->rsakey);
6614 * And send it off in a return packet.
6616 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
6617 ssh2_pkt_addstring_start(s->pktout);
6618 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
6619 ssh2_pkt_send_noqueue(ssh, s->pktout);
6621 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
6628 ssh_rsakex_freekey(s->rsakey);
6630 crWaitUntilV(pktin);
6631 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
6632 sfree(s->rsakeydata);
6633 bombout(("expected signature packet from server"));
6637 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6639 sfree(s->rsakeydata);
6642 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
6643 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
6644 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
6646 ssh->kex_ctx = NULL;
6649 debug(("Exchange hash is:\n"));
6650 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
6654 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
6655 (char *)s->exchange_hash,
6656 ssh->kex->hash->hlen)) {
6657 bombout(("Server's host key did not match the signature supplied"));
6661 s->keystr = ssh->hostkey->fmtkey(s->hkey);
6662 if (!s->got_session_id) {
6664 * Authenticate remote host: verify host key. (We've already
6665 * checked the signature of the exchange hash.)
6667 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
6668 ssh_set_frozen(ssh, 1);
6669 s->dlgret = verify_ssh_host_key(ssh->frontend,
6670 ssh->savedhost, ssh->savedport,
6671 ssh->hostkey->keytype, s->keystr,
6673 ssh_dialog_callback, ssh);
6674 if (s->dlgret < 0) {
6678 bombout(("Unexpected data from server while waiting"
6679 " for user host key response"));
6682 } while (pktin || inlen > 0);
6683 s->dlgret = ssh->user_response;
6685 ssh_set_frozen(ssh, 0);
6686 if (s->dlgret == 0) {
6687 ssh_disconnect(ssh, "User aborted at host key verification", NULL,
6691 logevent("Host key fingerprint is:");
6692 logevent(s->fingerprint);
6693 sfree(s->fingerprint);
6695 * Save this host key, to check against the one presented in
6696 * subsequent rekeys.
6698 ssh->hostkey_str = s->keystr;
6701 * In a rekey, we never present an interactive host key
6702 * verification request to the user. Instead, we simply
6703 * enforce that the key we're seeing this time is identical to
6704 * the one we saw before.
6706 if (strcmp(ssh->hostkey_str, s->keystr)) {
6707 bombout(("Host key was different in repeat key exchange"));
6712 ssh->hostkey->freekey(s->hkey);
6715 * The exchange hash from the very first key exchange is also
6716 * the session id, used in session key construction and
6719 if (!s->got_session_id) {
6720 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
6721 memcpy(ssh->v2_session_id, s->exchange_hash,
6722 sizeof(s->exchange_hash));
6723 ssh->v2_session_id_len = ssh->kex->hash->hlen;
6724 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
6725 s->got_session_id = TRUE;
6729 * Send SSH2_MSG_NEWKEYS.
6731 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
6732 ssh2_pkt_send_noqueue(ssh, s->pktout);
6733 ssh->outgoing_data_size = 0; /* start counting from here */
6736 * We've sent client NEWKEYS, so create and initialise
6737 * client-to-server session keys.
6739 if (ssh->cs_cipher_ctx)
6740 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6741 ssh->cscipher = s->cscipher_tobe;
6742 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
6744 if (ssh->cs_mac_ctx)
6745 ssh->csmac->free_context(ssh->cs_mac_ctx);
6746 ssh->csmac = s->csmac_tobe;
6747 ssh->cs_mac_ctx = ssh->csmac->make_context();
6749 if (ssh->cs_comp_ctx)
6750 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6751 ssh->cscomp = s->cscomp_tobe;
6752 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
6755 * Set IVs on client-to-server keys. Here we use the exchange
6756 * hash from the _first_ key exchange.
6759 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6760 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6761 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
6762 assert((ssh->cscipher->keylen+7) / 8 <=
6763 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6764 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
6765 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
6766 assert(ssh->cscipher->blksize <=
6767 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6768 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
6769 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
6770 assert(ssh->csmac->len <=
6771 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6772 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
6773 smemclr(keyspace, sizeof(keyspace));
6776 logeventf(ssh, "Initialised %.200s client->server encryption",
6777 ssh->cscipher->text_name);
6778 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
6779 ssh->csmac->text_name);
6780 if (ssh->cscomp->text_name)
6781 logeventf(ssh, "Initialised %s compression",
6782 ssh->cscomp->text_name);
6785 * Now our end of the key exchange is complete, we can send all
6786 * our queued higher-layer packets.
6788 ssh->queueing = FALSE;
6789 ssh2_pkt_queuesend(ssh);
6792 * Expect SSH2_MSG_NEWKEYS from server.
6794 crWaitUntilV(pktin);
6795 if (pktin->type != SSH2_MSG_NEWKEYS) {
6796 bombout(("expected new-keys packet from server"));
6799 ssh->incoming_data_size = 0; /* start counting from here */
6802 * We've seen server NEWKEYS, so create and initialise
6803 * server-to-client session keys.
6805 if (ssh->sc_cipher_ctx)
6806 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6807 ssh->sccipher = s->sccipher_tobe;
6808 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
6810 if (ssh->sc_mac_ctx)
6811 ssh->scmac->free_context(ssh->sc_mac_ctx);
6812 ssh->scmac = s->scmac_tobe;
6813 ssh->sc_mac_ctx = ssh->scmac->make_context();
6815 if (ssh->sc_comp_ctx)
6816 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
6817 ssh->sccomp = s->sccomp_tobe;
6818 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
6821 * Set IVs on server-to-client keys. Here we use the exchange
6822 * hash from the _first_ key exchange.
6825 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6826 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6827 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
6828 assert((ssh->sccipher->keylen+7) / 8 <=
6829 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6830 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
6831 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
6832 assert(ssh->sccipher->blksize <=
6833 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6834 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
6835 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
6836 assert(ssh->scmac->len <=
6837 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6838 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
6839 smemclr(keyspace, sizeof(keyspace));
6841 logeventf(ssh, "Initialised %.200s server->client encryption",
6842 ssh->sccipher->text_name);
6843 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
6844 ssh->scmac->text_name);
6845 if (ssh->sccomp->text_name)
6846 logeventf(ssh, "Initialised %s decompression",
6847 ssh->sccomp->text_name);
6850 * Free shared secret.
6855 * Key exchange is over. Loop straight back round if we have a
6856 * deferred rekey reason.
6858 if (ssh->deferred_rekey_reason) {
6859 logevent(ssh->deferred_rekey_reason);
6861 ssh->deferred_rekey_reason = NULL;
6862 goto begin_key_exchange;
6866 * Otherwise, schedule a timer for our next rekey.
6868 ssh->kex_in_progress = FALSE;
6869 ssh->last_rekey = GETTICKCOUNT();
6870 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
6871 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
6875 * Now we're encrypting. Begin returning 1 to the protocol main
6876 * function so that other things can run on top of the
6877 * transport. If we ever see a KEXINIT, we must go back to the
6880 * We _also_ go back to the start if we see pktin==NULL and
6881 * inlen negative, because this is a special signal meaning
6882 * `initiate client-driven rekey', and `in' contains a message
6883 * giving the reason for the rekey.
6885 * inlen==-1 means always initiate a rekey;
6886 * inlen==-2 means that userauth has completed successfully and
6887 * we should consider rekeying (for delayed compression).
6889 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
6890 (!pktin && inlen < 0))) {
6892 if (!ssh->protocol_initial_phase_done) {
6893 ssh->protocol_initial_phase_done = TRUE;
6895 * Allow authconn to initialise itself.
6897 do_ssh2_authconn(ssh, NULL, 0, NULL);
6902 logevent("Server initiated key re-exchange");
6906 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
6907 * delayed compression, if it's available.
6909 * draft-miller-secsh-compression-delayed-00 says that you
6910 * negotiate delayed compression in the first key exchange, and
6911 * both sides start compressing when the server has sent
6912 * USERAUTH_SUCCESS. This has a race condition -- the server
6913 * can't know when the client has seen it, and thus which incoming
6914 * packets it should treat as compressed.
6916 * Instead, we do the initial key exchange without offering the
6917 * delayed methods, but note if the server offers them; when we
6918 * get here, if a delayed method was available that was higher
6919 * on our list than what we got, we initiate a rekey in which we
6920 * _do_ list the delayed methods (and hopefully get it as a
6921 * result). Subsequent rekeys will do the same.
6923 assert(!s->userauth_succeeded); /* should only happen once */
6924 s->userauth_succeeded = TRUE;
6925 if (!s->pending_compression)
6926 /* Can't see any point rekeying. */
6927 goto wait_for_rekey; /* this is utterly horrid */
6928 /* else fall through to rekey... */
6929 s->pending_compression = FALSE;
6932 * Now we've decided to rekey.
6934 * Special case: if the server bug is set that doesn't
6935 * allow rekeying, we give a different log message and
6936 * continue waiting. (If such a server _initiates_ a rekey,
6937 * we process it anyway!)
6939 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
6940 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
6942 /* Reset the counters, so that at least this message doesn't
6943 * hit the event log _too_ often. */
6944 ssh->outgoing_data_size = 0;
6945 ssh->incoming_data_size = 0;
6946 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
6948 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
6951 goto wait_for_rekey; /* this is still utterly horrid */
6953 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
6956 goto begin_key_exchange;
6962 * Add data to an SSH-2 channel output buffer.
6964 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
6967 bufchain_add(&c->v.v2.outbuffer, buf, len);
6971 * Attempt to send data on an SSH-2 channel.
6973 static int ssh2_try_send(struct ssh_channel *c)
6976 struct Packet *pktout;
6979 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
6982 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
6983 if ((unsigned)len > c->v.v2.remwindow)
6984 len = c->v.v2.remwindow;
6985 if ((unsigned)len > c->v.v2.remmaxpkt)
6986 len = c->v.v2.remmaxpkt;
6987 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
6988 ssh2_pkt_adduint32(pktout, c->remoteid);
6989 ssh2_pkt_addstring_start(pktout);
6990 ssh2_pkt_addstring_data(pktout, data, len);
6991 ssh2_pkt_send(ssh, pktout);
6992 bufchain_consume(&c->v.v2.outbuffer, len);
6993 c->v.v2.remwindow -= len;
6997 * After having sent as much data as we can, return the amount
7000 ret = bufchain_size(&c->v.v2.outbuffer);
7003 * And if there's no data pending but we need to send an EOF, send
7006 if (!ret && c->pending_eof)
7007 ssh_channel_try_eof(c);
7012 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
7015 if (c->closes & CLOSES_SENT_EOF)
7016 return; /* don't send on channels we've EOFed */
7017 bufsize = ssh2_try_send(c);
7020 case CHAN_MAINSESSION:
7021 /* stdin need not receive an unthrottle
7022 * notification since it will be polled */
7025 x11_unthrottle(c->u.x11.xconn);
7028 /* agent sockets are request/response and need no
7029 * buffer management */
7032 pfd_unthrottle(c->u.pfd.pf);
7038 static int ssh_is_simple(Ssh ssh)
7041 * We use the 'simple' variant of the SSH protocol if we're asked
7042 * to, except not if we're also doing connection-sharing (either
7043 * tunnelling our packets over an upstream or expecting to be
7044 * tunnelled over ourselves), since then the assumption that we
7045 * have only one channel to worry about is not true after all.
7047 return (conf_get_int(ssh->conf, CONF_ssh_simple) &&
7048 !ssh->bare_connection && !ssh->connshare);
7052 * Set up most of a new ssh_channel for SSH-2.
7054 static void ssh2_channel_init(struct ssh_channel *c)
7057 c->localid = alloc_channel_id(ssh);
7059 c->pending_eof = FALSE;
7060 c->throttling_conn = FALSE;
7061 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
7062 ssh_is_simple(ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
7063 c->v.v2.chanreq_head = NULL;
7064 c->v.v2.throttle_state = UNTHROTTLED;
7065 bufchain_init(&c->v.v2.outbuffer);
7069 * Construct the common parts of a CHANNEL_OPEN.
7071 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c, char *type)
7073 struct Packet *pktout;
7075 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7076 ssh2_pkt_addstring(pktout, type);
7077 ssh2_pkt_adduint32(pktout, c->localid);
7078 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7079 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7084 * CHANNEL_FAILURE doesn't come with any indication of what message
7085 * caused it, so we have to keep track of the outstanding
7086 * CHANNEL_REQUESTs ourselves.
7088 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
7089 cchandler_fn_t handler, void *ctx)
7091 struct outstanding_channel_request *ocr =
7092 snew(struct outstanding_channel_request);
7094 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7095 ocr->handler = handler;
7098 if (!c->v.v2.chanreq_head)
7099 c->v.v2.chanreq_head = ocr;
7101 c->v.v2.chanreq_tail->next = ocr;
7102 c->v.v2.chanreq_tail = ocr;
7106 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
7107 * NULL then a reply will be requested and the handler will be called
7108 * when it arrives. The returned packet is ready to have any
7109 * request-specific data added and be sent. Note that if a handler is
7110 * provided, it's essential that the request actually be sent.
7112 * The handler will usually be passed the response packet in pktin.
7113 * If pktin is NULL, this means that no reply will ever be forthcoming
7114 * (e.g. because the entire connection is being destroyed) and the
7115 * handler should free any storage it's holding.
7117 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c, char *type,
7118 cchandler_fn_t handler, void *ctx)
7120 struct Packet *pktout;
7122 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7123 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7124 ssh2_pkt_adduint32(pktout, c->remoteid);
7125 ssh2_pkt_addstring(pktout, type);
7126 ssh2_pkt_addbool(pktout, handler != NULL);
7127 if (handler != NULL)
7128 ssh2_queue_chanreq_handler(c, handler, ctx);
7133 * Potentially enlarge the window on an SSH-2 channel.
7135 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
7137 static void ssh2_set_window(struct ssh_channel *c, int newwin)
7142 * Never send WINDOW_ADJUST for a channel that the remote side has
7143 * already sent EOF on; there's no point, since it won't be
7144 * sending any more data anyway. Ditto if _we've_ already sent
7147 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
7151 * Also, never widen the window for an X11 channel when we're
7152 * still waiting to see its initial auth and may yet hand it off
7155 if (c->type == CHAN_X11 && c->u.x11.initial)
7159 * If the remote end has a habit of ignoring maxpkt, limit the
7160 * window so that it has no choice (assuming it doesn't ignore the
7163 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
7164 newwin = OUR_V2_MAXPKT;
7167 * Only send a WINDOW_ADJUST if there's significantly more window
7168 * available than the other end thinks there is. This saves us
7169 * sending a WINDOW_ADJUST for every character in a shell session.
7171 * "Significant" is arbitrarily defined as half the window size.
7173 if (newwin / 2 >= c->v.v2.locwindow) {
7174 struct Packet *pktout;
7178 * In order to keep track of how much window the client
7179 * actually has available, we'd like it to acknowledge each
7180 * WINDOW_ADJUST. We can't do that directly, so we accompany
7181 * it with a CHANNEL_REQUEST that has to be acknowledged.
7183 * This is only necessary if we're opening the window wide.
7184 * If we're not, then throughput is being constrained by
7185 * something other than the maximum window size anyway.
7187 if (newwin == c->v.v2.locmaxwin &&
7188 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
7189 up = snew(unsigned);
7190 *up = newwin - c->v.v2.locwindow;
7191 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
7192 ssh2_handle_winadj_response, up);
7193 ssh2_pkt_send(ssh, pktout);
7195 if (c->v.v2.throttle_state != UNTHROTTLED)
7196 c->v.v2.throttle_state = UNTHROTTLING;
7198 /* Pretend the WINDOW_ADJUST was acked immediately. */
7199 c->v.v2.remlocwin = newwin;
7200 c->v.v2.throttle_state = THROTTLED;
7202 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7203 ssh2_pkt_adduint32(pktout, c->remoteid);
7204 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
7205 ssh2_pkt_send(ssh, pktout);
7206 c->v.v2.locwindow = newwin;
7211 * Find the channel associated with a message. If there's no channel,
7212 * or it's not properly open, make a noise about it and return NULL.
7214 static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
7216 unsigned localid = ssh_pkt_getuint32(pktin);
7217 struct ssh_channel *c;
7219 c = find234(ssh->channels, &localid, ssh_channelfind);
7221 (c->type != CHAN_SHARING && c->halfopen &&
7222 pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
7223 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
7224 char *buf = dupprintf("Received %s for %s channel %u",
7225 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
7227 c ? "half-open" : "nonexistent", localid);
7228 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
7235 static void ssh2_handle_winadj_response(struct ssh_channel *c,
7236 struct Packet *pktin, void *ctx)
7238 unsigned *sizep = ctx;
7241 * Winadj responses should always be failures. However, at least
7242 * one server ("boks_sshd") is known to return SUCCESS for channel
7243 * requests it's never heard of, such as "winadj@putty". Raised
7244 * with foxt.com as bug 090916-090424, but for the sake of a quiet
7245 * life, we don't worry about what kind of response we got.
7248 c->v.v2.remlocwin += *sizep;
7251 * winadj messages are only sent when the window is fully open, so
7252 * if we get an ack of one, we know any pending unthrottle is
7255 if (c->v.v2.throttle_state == UNTHROTTLING)
7256 c->v.v2.throttle_state = UNTHROTTLED;
7259 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
7261 struct ssh_channel *c = ssh2_channel_msg(ssh, pktin);
7262 struct outstanding_channel_request *ocr;
7265 if (c->type == CHAN_SHARING) {
7266 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7267 pktin->body, pktin->length);
7270 ocr = c->v.v2.chanreq_head;
7272 ssh2_msg_unexpected(ssh, pktin);
7275 ocr->handler(c, pktin, ocr->ctx);
7276 c->v.v2.chanreq_head = ocr->next;
7279 * We may now initiate channel-closing procedures, if that
7280 * CHANNEL_REQUEST was the last thing outstanding before we send
7283 ssh2_channel_check_close(c);
7286 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
7288 struct ssh_channel *c;
7289 c = ssh2_channel_msg(ssh, pktin);
7292 if (c->type == CHAN_SHARING) {
7293 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7294 pktin->body, pktin->length);
7297 if (!(c->closes & CLOSES_SENT_EOF)) {
7298 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
7299 ssh2_try_send_and_unthrottle(ssh, c);
7303 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
7307 struct ssh_channel *c;
7308 c = ssh2_channel_msg(ssh, pktin);
7311 if (c->type == CHAN_SHARING) {
7312 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7313 pktin->body, pktin->length);
7316 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
7317 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
7318 return; /* extended but not stderr */
7319 ssh_pkt_getstring(pktin, &data, &length);
7322 c->v.v2.locwindow -= length;
7323 c->v.v2.remlocwin -= length;
7325 case CHAN_MAINSESSION:
7327 from_backend(ssh->frontend, pktin->type ==
7328 SSH2_MSG_CHANNEL_EXTENDED_DATA,
7332 bufsize = x11_send(c->u.x11.xconn, data, length);
7335 bufsize = pfd_send(c->u.pfd.pf, data, length);
7338 while (length > 0) {
7339 if (c->u.a.lensofar < 4) {
7340 unsigned int l = min(4 - c->u.a.lensofar,
7342 memcpy(c->u.a.msglen + c->u.a.lensofar,
7346 c->u.a.lensofar += l;
7348 if (c->u.a.lensofar == 4) {
7350 4 + GET_32BIT(c->u.a.msglen);
7351 c->u.a.message = snewn(c->u.a.totallen,
7353 memcpy(c->u.a.message, c->u.a.msglen, 4);
7355 if (c->u.a.lensofar >= 4 && length > 0) {
7357 min(c->u.a.totallen - c->u.a.lensofar,
7359 memcpy(c->u.a.message + c->u.a.lensofar,
7363 c->u.a.lensofar += l;
7365 if (c->u.a.lensofar == c->u.a.totallen) {
7368 c->u.a.outstanding_requests++;
7369 if (agent_query(c->u.a.message,
7372 ssh_agentf_callback, c))
7373 ssh_agentf_callback(c, reply, replylen);
7374 sfree(c->u.a.message);
7375 c->u.a.message = NULL;
7376 c->u.a.lensofar = 0;
7383 * If it looks like the remote end hit the end of its window,
7384 * and we didn't want it to do that, think about using a
7387 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
7388 c->v.v2.locmaxwin < 0x40000000)
7389 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
7391 * If we are not buffering too much data,
7392 * enlarge the window again at the remote side.
7393 * If we are buffering too much, we may still
7394 * need to adjust the window if the server's
7397 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
7398 c->v.v2.locmaxwin - bufsize : 0);
7400 * If we're either buffering way too much data, or if we're
7401 * buffering anything at all and we're in "simple" mode,
7402 * throttle the whole channel.
7404 if ((bufsize > c->v.v2.locmaxwin || (ssh_is_simple(ssh) && bufsize>0))
7405 && !c->throttling_conn) {
7406 c->throttling_conn = 1;
7407 ssh_throttle_conn(ssh, +1);
7412 static void ssh_check_termination(Ssh ssh)
7414 if (ssh->version == 2 &&
7415 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
7416 count234(ssh->channels) == 0 &&
7417 !(ssh->connshare && share_ndownstreams(ssh->connshare) > 0)) {
7419 * We used to send SSH_MSG_DISCONNECT here, because I'd
7420 * believed that _every_ conforming SSH-2 connection had to
7421 * end with a disconnect being sent by at least one side;
7422 * apparently I was wrong and it's perfectly OK to
7423 * unceremoniously slam the connection shut when you're done,
7424 * and indeed OpenSSH feels this is more polite than sending a
7425 * DISCONNECT. So now we don't.
7427 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
7431 void ssh_sharing_downstream_connected(Ssh ssh, unsigned id)
7433 logeventf(ssh, "Connection sharing downstream #%u connected", id);
7436 void ssh_sharing_downstream_disconnected(Ssh ssh, unsigned id)
7438 logeventf(ssh, "Connection sharing downstream #%u disconnected", id);
7439 ssh_check_termination(ssh);
7442 void ssh_sharing_logf(Ssh ssh, unsigned id, const char *logfmt, ...)
7447 va_start(ap, logfmt);
7448 buf = dupvprintf(logfmt, ap);
7451 logeventf(ssh, "Connection sharing downstream #%u: %s", id, buf);
7453 logeventf(ssh, "Connection sharing: %s", buf);
7457 static void ssh_channel_destroy(struct ssh_channel *c)
7462 case CHAN_MAINSESSION:
7463 ssh->mainchan = NULL;
7464 update_specials_menu(ssh->frontend);
7467 if (c->u.x11.xconn != NULL)
7468 x11_close(c->u.x11.xconn);
7469 logevent("Forwarded X11 connection terminated");
7472 sfree(c->u.a.message);
7475 if (c->u.pfd.pf != NULL)
7476 pfd_close(c->u.pfd.pf);
7477 logevent("Forwarded port closed");
7481 del234(ssh->channels, c);
7482 if (ssh->version == 2) {
7483 bufchain_clear(&c->v.v2.outbuffer);
7484 assert(c->v.v2.chanreq_head == NULL);
7489 * If that was the last channel left open, we might need to
7492 ssh_check_termination(ssh);
7495 static void ssh2_channel_check_close(struct ssh_channel *c)
7498 struct Packet *pktout;
7502 * If we've sent out our own CHANNEL_OPEN but not yet seen
7503 * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
7504 * it's too early to be sending close messages of any kind.
7509 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
7510 c->type == CHAN_ZOMBIE) &&
7511 !c->v.v2.chanreq_head &&
7512 !(c->closes & CLOSES_SENT_CLOSE)) {
7514 * We have both sent and received EOF (or the channel is a
7515 * zombie), and we have no outstanding channel requests, which
7516 * means the channel is in final wind-up. But we haven't sent
7517 * CLOSE, so let's do so now.
7519 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
7520 ssh2_pkt_adduint32(pktout, c->remoteid);
7521 ssh2_pkt_send(ssh, pktout);
7522 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
7525 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
7526 assert(c->v.v2.chanreq_head == NULL);
7528 * We have both sent and received CLOSE, which means we're
7529 * completely done with the channel.
7531 ssh_channel_destroy(c);
7535 static void ssh2_channel_got_eof(struct ssh_channel *c)
7537 if (c->closes & CLOSES_RCVD_EOF)
7538 return; /* already seen EOF */
7539 c->closes |= CLOSES_RCVD_EOF;
7541 if (c->type == CHAN_X11) {
7542 x11_send_eof(c->u.x11.xconn);
7543 } else if (c->type == CHAN_AGENT) {
7544 if (c->u.a.outstanding_requests == 0) {
7545 /* Manufacture an outgoing EOF in response to the incoming one. */
7546 sshfwd_write_eof(c);
7548 } else if (c->type == CHAN_SOCKDATA) {
7549 pfd_send_eof(c->u.pfd.pf);
7550 } else if (c->type == CHAN_MAINSESSION) {
7553 if (!ssh->sent_console_eof &&
7554 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
7556 * Either from_backend_eof told us that the front end
7557 * wants us to close the outgoing side of the connection
7558 * as soon as we see EOF from the far end, or else we've
7559 * unilaterally decided to do that because we've allocated
7560 * a remote pty and hence EOF isn't a particularly
7561 * meaningful concept.
7563 sshfwd_write_eof(c);
7565 ssh->sent_console_eof = TRUE;
7568 ssh2_channel_check_close(c);
7571 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
7573 struct ssh_channel *c;
7575 c = ssh2_channel_msg(ssh, pktin);
7578 if (c->type == CHAN_SHARING) {
7579 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7580 pktin->body, pktin->length);
7583 ssh2_channel_got_eof(c);
7586 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
7588 struct ssh_channel *c;
7590 c = ssh2_channel_msg(ssh, pktin);
7593 if (c->type == CHAN_SHARING) {
7594 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7595 pktin->body, pktin->length);
7600 * When we receive CLOSE on a channel, we assume it comes with an
7601 * implied EOF if we haven't seen EOF yet.
7603 ssh2_channel_got_eof(c);
7606 * And we also send an outgoing EOF, if we haven't already, on the
7607 * assumption that CLOSE is a pretty forceful announcement that
7608 * the remote side is doing away with the entire channel. (If it
7609 * had wanted to send us EOF and continue receiving data from us,
7610 * it would have just sent CHANNEL_EOF.)
7612 if (!(c->closes & CLOSES_SENT_EOF)) {
7614 * Make sure we don't read any more from whatever our local
7615 * data source is for this channel.
7618 case CHAN_MAINSESSION:
7619 ssh->send_ok = 0; /* stop trying to read from stdin */
7622 x11_override_throttle(c->u.x11.xconn, 1);
7625 pfd_override_throttle(c->u.pfd.pf, 1);
7630 * Abandon any buffered data we still wanted to send to this
7631 * channel. Receiving a CHANNEL_CLOSE is an indication that
7632 * the server really wants to get on and _destroy_ this
7633 * channel, and it isn't going to send us any further
7634 * WINDOW_ADJUSTs to permit us to send pending stuff.
7636 bufchain_clear(&c->v.v2.outbuffer);
7639 * Send outgoing EOF.
7641 sshfwd_write_eof(c);
7645 * Now process the actual close.
7647 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
7648 c->closes |= CLOSES_RCVD_CLOSE;
7649 ssh2_channel_check_close(c);
7653 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
7655 struct ssh_channel *c;
7657 c = ssh2_channel_msg(ssh, pktin);
7660 if (c->type == CHAN_SHARING) {
7661 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7662 pktin->body, pktin->length);
7665 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7666 c->remoteid = ssh_pkt_getuint32(pktin);
7667 c->halfopen = FALSE;
7668 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7669 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7671 if (c->type == CHAN_SOCKDATA_DORMANT) {
7672 c->type = CHAN_SOCKDATA;
7674 pfd_confirm(c->u.pfd.pf);
7675 } else if (c->type == CHAN_ZOMBIE) {
7677 * This case can occur if a local socket error occurred
7678 * between us sending out CHANNEL_OPEN and receiving
7679 * OPEN_CONFIRMATION. In this case, all we can do is
7680 * immediately initiate close proceedings now that we know the
7681 * server's id to put in the close message.
7683 ssh2_channel_check_close(c);
7686 * We never expect to receive OPEN_CONFIRMATION for any
7687 * *other* channel type (since only local-to-remote port
7688 * forwardings cause us to send CHANNEL_OPEN after the main
7689 * channel is live - all other auxiliary channel types are
7690 * initiated from the server end). It's safe to enforce this
7691 * by assertion rather than by ssh_disconnect, because the
7692 * real point is that we never constructed a half-open channel
7693 * structure in the first place with any type other than the
7696 assert(!"Funny channel type in ssh2_msg_channel_open_confirmation");
7700 ssh_channel_try_eof(c); /* in case we had a pending EOF */
7703 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
7705 static const char *const reasons[] = {
7706 "<unknown reason code>",
7707 "Administratively prohibited",
7709 "Unknown channel type",
7710 "Resource shortage",
7712 unsigned reason_code;
7713 char *reason_string;
7715 struct ssh_channel *c;
7717 c = ssh2_channel_msg(ssh, pktin);
7720 if (c->type == CHAN_SHARING) {
7721 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7722 pktin->body, pktin->length);
7725 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7727 if (c->type == CHAN_SOCKDATA_DORMANT) {
7728 reason_code = ssh_pkt_getuint32(pktin);
7729 if (reason_code >= lenof(reasons))
7730 reason_code = 0; /* ensure reasons[reason_code] in range */
7731 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
7732 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
7733 reasons[reason_code], reason_length, reason_string);
7735 pfd_close(c->u.pfd.pf);
7736 } else if (c->type == CHAN_ZOMBIE) {
7738 * This case can occur if a local socket error occurred
7739 * between us sending out CHANNEL_OPEN and receiving
7740 * OPEN_FAILURE. In this case, we need do nothing except allow
7741 * the code below to throw the half-open channel away.
7745 * We never expect to receive OPEN_FAILURE for any *other*
7746 * channel type (since only local-to-remote port forwardings
7747 * cause us to send CHANNEL_OPEN after the main channel is
7748 * live - all other auxiliary channel types are initiated from
7749 * the server end). It's safe to enforce this by assertion
7750 * rather than by ssh_disconnect, because the real point is
7751 * that we never constructed a half-open channel structure in
7752 * the first place with any type other than the above.
7754 assert(!"Funny channel type in ssh2_msg_channel_open_failure");
7757 del234(ssh->channels, c);
7761 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
7764 int typelen, want_reply;
7765 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
7766 struct ssh_channel *c;
7767 struct Packet *pktout;
7769 c = ssh2_channel_msg(ssh, pktin);
7772 if (c->type == CHAN_SHARING) {
7773 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7774 pktin->body, pktin->length);
7777 ssh_pkt_getstring(pktin, &type, &typelen);
7778 want_reply = ssh2_pkt_getbool(pktin);
7781 * Having got the channel number, we now look at
7782 * the request type string to see if it's something
7785 if (c == ssh->mainchan) {
7787 * We recognise "exit-status" and "exit-signal" on
7788 * the primary channel.
7790 if (typelen == 11 &&
7791 !memcmp(type, "exit-status", 11)) {
7793 ssh->exitcode = ssh_pkt_getuint32(pktin);
7794 logeventf(ssh, "Server sent command exit status %d",
7796 reply = SSH2_MSG_CHANNEL_SUCCESS;
7798 } else if (typelen == 11 &&
7799 !memcmp(type, "exit-signal", 11)) {
7801 int is_plausible = TRUE, is_int = FALSE;
7802 char *fmt_sig = "", *fmt_msg = "";
7804 int msglen = 0, core = FALSE;
7805 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
7806 * provide an `int' for the signal, despite its
7807 * having been a `string' in the drafts of RFC 4254 since at
7808 * least 2001. (Fixed in session.c 1.147.) Try to
7809 * infer which we can safely parse it as. */
7811 unsigned char *p = pktin->body +
7813 long len = pktin->length - pktin->savedpos;
7814 unsigned long num = GET_32BIT(p); /* what is it? */
7815 /* If it's 0, it hardly matters; assume string */
7819 int maybe_int = FALSE, maybe_str = FALSE;
7820 #define CHECK_HYPOTHESIS(offset, result) \
7823 int q = toint(offset); \
7824 if (q >= 0 && q+4 <= len) { \
7825 q = toint(q + 4 + GET_32BIT(p+q)); \
7826 if (q >= 0 && q+4 <= len && \
7827 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
7832 CHECK_HYPOTHESIS(4+1, maybe_int);
7833 CHECK_HYPOTHESIS(4+num+1, maybe_str);
7834 #undef CHECK_HYPOTHESIS
7835 if (maybe_int && !maybe_str)
7837 else if (!maybe_int && maybe_str)
7840 /* Crikey. Either or neither. Panic. */
7841 is_plausible = FALSE;
7844 ssh->exitcode = 128; /* means `unknown signal' */
7847 /* Old non-standard OpenSSH. */
7848 int signum = ssh_pkt_getuint32(pktin);
7849 fmt_sig = dupprintf(" %d", signum);
7850 ssh->exitcode = 128 + signum;
7852 /* As per RFC 4254. */
7855 ssh_pkt_getstring(pktin, &sig, &siglen);
7856 /* Signal name isn't supposed to be blank, but
7857 * let's cope gracefully if it is. */
7859 fmt_sig = dupprintf(" \"%.*s\"",
7864 * Really hideous method of translating the
7865 * signal description back into a locally
7866 * meaningful number.
7871 #define TRANSLATE_SIGNAL(s) \
7872 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
7873 ssh->exitcode = 128 + SIG ## s
7875 TRANSLATE_SIGNAL(ABRT);
7878 TRANSLATE_SIGNAL(ALRM);
7881 TRANSLATE_SIGNAL(FPE);
7884 TRANSLATE_SIGNAL(HUP);
7887 TRANSLATE_SIGNAL(ILL);
7890 TRANSLATE_SIGNAL(INT);
7893 TRANSLATE_SIGNAL(KILL);
7896 TRANSLATE_SIGNAL(PIPE);
7899 TRANSLATE_SIGNAL(QUIT);
7902 TRANSLATE_SIGNAL(SEGV);
7905 TRANSLATE_SIGNAL(TERM);
7908 TRANSLATE_SIGNAL(USR1);
7911 TRANSLATE_SIGNAL(USR2);
7913 #undef TRANSLATE_SIGNAL
7915 ssh->exitcode = 128;
7917 core = ssh2_pkt_getbool(pktin);
7918 ssh_pkt_getstring(pktin, &msg, &msglen);
7920 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
7922 /* ignore lang tag */
7923 } /* else don't attempt to parse */
7924 logeventf(ssh, "Server exited on signal%s%s%s",
7925 fmt_sig, core ? " (core dumped)" : "",
7927 if (*fmt_sig) sfree(fmt_sig);
7928 if (*fmt_msg) sfree(fmt_msg);
7929 reply = SSH2_MSG_CHANNEL_SUCCESS;
7934 * This is a channel request we don't know
7935 * about, so we now either ignore the request
7936 * or respond with CHANNEL_FAILURE, depending
7939 reply = SSH2_MSG_CHANNEL_FAILURE;
7942 pktout = ssh2_pkt_init(reply);
7943 ssh2_pkt_adduint32(pktout, c->remoteid);
7944 ssh2_pkt_send(ssh, pktout);
7948 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
7951 int typelen, want_reply;
7952 struct Packet *pktout;
7954 ssh_pkt_getstring(pktin, &type, &typelen);
7955 want_reply = ssh2_pkt_getbool(pktin);
7958 * We currently don't support any global requests
7959 * at all, so we either ignore the request or
7960 * respond with REQUEST_FAILURE, depending on
7964 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
7965 ssh2_pkt_send(ssh, pktout);
7969 struct X11FakeAuth *ssh_sharing_add_x11_display(Ssh ssh, int authtype,
7973 struct X11FakeAuth *auth;
7976 * Make up a new set of fake X11 auth data, and add it to the tree
7977 * of currently valid ones with an indication of the sharing
7978 * context that it's relevant to.
7980 auth = x11_invent_fake_auth(ssh->x11authtree, authtype);
7981 auth->share_cs = share_cs;
7982 auth->share_chan = share_chan;
7987 void ssh_sharing_remove_x11_display(Ssh ssh, struct X11FakeAuth *auth)
7989 del234(ssh->x11authtree, auth);
7990 x11_free_fake_auth(auth);
7993 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
8001 struct ssh_channel *c;
8002 unsigned remid, winsize, pktsize;
8003 unsigned our_winsize_override = 0;
8004 struct Packet *pktout;
8006 ssh_pkt_getstring(pktin, &type, &typelen);
8007 c = snew(struct ssh_channel);
8010 remid = ssh_pkt_getuint32(pktin);
8011 winsize = ssh_pkt_getuint32(pktin);
8012 pktsize = ssh_pkt_getuint32(pktin);
8014 if (typelen == 3 && !memcmp(type, "x11", 3)) {
8017 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8018 addrstr = snewn(peeraddrlen+1, char);
8019 memcpy(addrstr, peeraddr, peeraddrlen);
8020 addrstr[peeraddrlen] = '\0';
8021 peerport = ssh_pkt_getuint32(pktin);
8023 logeventf(ssh, "Received X11 connect request from %s:%d",
8026 if (!ssh->X11_fwd_enabled && !ssh->connshare)
8027 error = "X11 forwarding is not enabled";
8029 c->u.x11.xconn = x11_init(ssh->x11authtree, c,
8032 c->u.x11.initial = TRUE;
8035 * If we are a connection-sharing upstream, then we should
8036 * initially present a very small window, adequate to take
8037 * the X11 initial authorisation packet but not much more.
8038 * Downstream will then present us a larger window (by
8039 * fiat of the connection-sharing protocol) and we can
8040 * guarantee to send a positive-valued WINDOW_ADJUST.
8043 our_winsize_override = 128;
8045 logevent("Opened X11 forward channel");
8049 } else if (typelen == 15 &&
8050 !memcmp(type, "forwarded-tcpip", 15)) {
8051 struct ssh_rportfwd pf, *realpf;
8054 ssh_pkt_getstring(pktin, &shost, &shostlen);/* skip address */
8055 pf.shost = dupprintf("%.*s", shostlen, shost);
8056 pf.sport = ssh_pkt_getuint32(pktin);
8057 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8058 peerport = ssh_pkt_getuint32(pktin);
8059 realpf = find234(ssh->rportfwds, &pf, NULL);
8060 logeventf(ssh, "Received remote port %s:%d open request "
8061 "from %s:%d", pf.shost, pf.sport, peeraddr, peerport);
8064 if (realpf == NULL) {
8065 error = "Remote port is not recognised";
8069 if (realpf->share_ctx) {
8071 * This port forwarding is on behalf of a
8072 * connection-sharing downstream, so abandon our own
8073 * channel-open procedure and just pass the message on
8076 share_got_pkt_from_server(realpf->share_ctx, pktin->type,
8077 pktin->body, pktin->length);
8082 err = pfd_connect(&c->u.pfd.pf, realpf->dhost, realpf->dport,
8083 c, ssh->conf, realpf->pfrec->addressfamily);
8084 logeventf(ssh, "Attempting to forward remote port to "
8085 "%s:%d", realpf->dhost, realpf->dport);
8087 logeventf(ssh, "Port open failed: %s", err);
8089 error = "Port open failed";
8091 logevent("Forwarded port opened successfully");
8092 c->type = CHAN_SOCKDATA;
8095 } else if (typelen == 22 &&
8096 !memcmp(type, "auth-agent@openssh.com", 22)) {
8097 if (!ssh->agentfwd_enabled)
8098 error = "Agent forwarding is not enabled";
8100 c->type = CHAN_AGENT; /* identify channel type */
8101 c->u.a.lensofar = 0;
8102 c->u.a.message = NULL;
8103 c->u.a.outstanding_requests = 0;
8106 error = "Unsupported channel type requested";
8109 c->remoteid = remid;
8110 c->halfopen = FALSE;
8112 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
8113 ssh2_pkt_adduint32(pktout, c->remoteid);
8114 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
8115 ssh2_pkt_addstring(pktout, error);
8116 ssh2_pkt_addstring(pktout, "en"); /* language tag */
8117 ssh2_pkt_send(ssh, pktout);
8118 logeventf(ssh, "Rejected channel open: %s", error);
8121 ssh2_channel_init(c);
8122 c->v.v2.remwindow = winsize;
8123 c->v.v2.remmaxpkt = pktsize;
8124 if (our_winsize_override) {
8125 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
8126 our_winsize_override;
8128 add234(ssh->channels, c);
8129 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
8130 ssh2_pkt_adduint32(pktout, c->remoteid);
8131 ssh2_pkt_adduint32(pktout, c->localid);
8132 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
8133 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8134 ssh2_pkt_send(ssh, pktout);
8138 void sshfwd_x11_sharing_handover(struct ssh_channel *c,
8139 void *share_cs, void *share_chan,
8140 const char *peer_addr, int peer_port,
8141 int endian, int protomajor, int protominor,
8142 const void *initial_data, int initial_len)
8145 * This function is called when we've just discovered that an X
8146 * forwarding channel on which we'd been handling the initial auth
8147 * ourselves turns out to be destined for a connection-sharing
8148 * downstream. So we turn the channel into a CHAN_SHARING, meaning
8149 * that we completely stop tracking windows and buffering data and
8150 * just pass more or less unmodified SSH messages back and forth.
8152 c->type = CHAN_SHARING;
8153 c->u.sharing.ctx = share_cs;
8154 share_setup_x11_channel(share_cs, share_chan,
8155 c->localid, c->remoteid, c->v.v2.remwindow,
8156 c->v.v2.remmaxpkt, c->v.v2.locwindow,
8157 peer_addr, peer_port, endian,
8158 protomajor, protominor,
8159 initial_data, initial_len);
8162 void sshfwd_x11_is_local(struct ssh_channel *c)
8165 * This function is called when we've just discovered that an X
8166 * forwarding channel is _not_ destined for a connection-sharing
8167 * downstream but we're going to handle it ourselves. We stop
8168 * presenting a cautiously small window and go into ordinary data
8171 c->u.x11.initial = FALSE;
8172 ssh2_set_window(c, ssh_is_simple(c->ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE);
8176 * Buffer banner messages for later display at some convenient point,
8177 * if we're going to display them.
8179 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
8181 /* Arbitrary limit to prevent unbounded inflation of buffer */
8182 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
8183 bufchain_size(&ssh->banner) <= 131072) {
8184 char *banner = NULL;
8186 ssh_pkt_getstring(pktin, &banner, &size);
8188 bufchain_add(&ssh->banner, banner, size);
8192 /* Helper function to deal with sending tty modes for "pty-req" */
8193 static void ssh2_send_ttymode(void *data, char *mode, char *val)
8195 struct Packet *pktout = (struct Packet *)data;
8197 unsigned int arg = 0;
8198 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
8199 if (i == lenof(ssh_ttymodes)) return;
8200 switch (ssh_ttymodes[i].type) {
8202 arg = ssh_tty_parse_specchar(val);
8205 arg = ssh_tty_parse_boolean(val);
8208 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
8209 ssh2_pkt_adduint32(pktout, arg);
8212 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
8215 struct ssh2_setup_x11_state {
8219 struct Packet *pktout;
8220 crStateP(ssh2_setup_x11_state, ctx);
8224 logevent("Requesting X11 forwarding");
8225 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
8227 ssh2_pkt_addbool(pktout, 0); /* many connections */
8228 ssh2_pkt_addstring(pktout, ssh->x11auth->protoname);
8229 ssh2_pkt_addstring(pktout, ssh->x11auth->datastring);
8230 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
8231 ssh2_pkt_send(ssh, pktout);
8233 /* Wait to be called back with either a response packet, or NULL
8234 * meaning clean up and free our data */
8238 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8239 logevent("X11 forwarding enabled");
8240 ssh->X11_fwd_enabled = TRUE;
8242 logevent("X11 forwarding refused");
8248 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
8251 struct ssh2_setup_agent_state {
8255 struct Packet *pktout;
8256 crStateP(ssh2_setup_agent_state, ctx);
8260 logevent("Requesting OpenSSH-style agent forwarding");
8261 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
8262 ssh2_setup_agent, s);
8263 ssh2_pkt_send(ssh, pktout);
8265 /* Wait to be called back with either a response packet, or NULL
8266 * meaning clean up and free our data */
8270 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8271 logevent("Agent forwarding enabled");
8272 ssh->agentfwd_enabled = TRUE;
8274 logevent("Agent forwarding refused");
8280 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
8283 struct ssh2_setup_pty_state {
8287 struct Packet *pktout;
8288 crStateP(ssh2_setup_pty_state, ctx);
8292 /* Unpick the terminal-speed string. */
8293 /* XXX perhaps we should allow no speeds to be sent. */
8294 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
8295 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
8296 /* Build the pty request. */
8297 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
8299 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
8300 ssh2_pkt_adduint32(pktout, ssh->term_width);
8301 ssh2_pkt_adduint32(pktout, ssh->term_height);
8302 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
8303 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
8304 ssh2_pkt_addstring_start(pktout);
8305 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
8306 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
8307 ssh2_pkt_adduint32(pktout, ssh->ispeed);
8308 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
8309 ssh2_pkt_adduint32(pktout, ssh->ospeed);
8310 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
8311 ssh2_pkt_send(ssh, pktout);
8312 ssh->state = SSH_STATE_INTERMED;
8314 /* Wait to be called back with either a response packet, or NULL
8315 * meaning clean up and free our data */
8319 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8320 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
8321 ssh->ospeed, ssh->ispeed);
8322 ssh->got_pty = TRUE;
8324 c_write_str(ssh, "Server refused to allocate pty\r\n");
8325 ssh->editing = ssh->echoing = 1;
8332 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
8335 struct ssh2_setup_env_state {
8337 int num_env, env_left, env_ok;
8340 struct Packet *pktout;
8341 crStateP(ssh2_setup_env_state, ctx);
8346 * Send environment variables.
8348 * Simplest thing here is to send all the requests at once, and
8349 * then wait for a whole bunch of successes or failures.
8355 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
8357 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
8358 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
8359 ssh2_pkt_addstring(pktout, key);
8360 ssh2_pkt_addstring(pktout, val);
8361 ssh2_pkt_send(ssh, pktout);
8366 logeventf(ssh, "Sent %d environment variables", s->num_env);
8371 s->env_left = s->num_env;
8373 while (s->env_left > 0) {
8374 /* Wait to be called back with either a response packet,
8375 * or NULL meaning clean up and free our data */
8377 if (!pktin) goto out;
8378 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
8383 if (s->env_ok == s->num_env) {
8384 logevent("All environment variables successfully set");
8385 } else if (s->env_ok == 0) {
8386 logevent("All environment variables refused");
8387 c_write_str(ssh, "Server refused to set environment variables\r\n");
8389 logeventf(ssh, "%d environment variables refused",
8390 s->num_env - s->env_ok);
8391 c_write_str(ssh, "Server refused to set all environment variables\r\n");
8399 * Handle the SSH-2 userauth and connection layers.
8401 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
8403 do_ssh2_authconn(ssh, NULL, 0, pktin);
8406 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
8409 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
8412 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
8413 struct Packet *pktin)
8415 struct do_ssh2_authconn_state {
8419 AUTH_TYPE_PUBLICKEY,
8420 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
8421 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
8423 AUTH_TYPE_GSSAPI, /* always QUIET */
8424 AUTH_TYPE_KEYBOARD_INTERACTIVE,
8425 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
8427 int done_service_req;
8428 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
8429 int tried_pubkey_config, done_agent;
8434 int kbd_inter_refused;
8435 int we_are_in, userauth_success;
8436 prompts_t *cur_prompt;
8441 void *publickey_blob;
8442 int publickey_bloblen;
8443 int publickey_encrypted;
8444 char *publickey_algorithm;
8445 char *publickey_comment;
8446 unsigned char agent_request[5], *agent_response, *agentp;
8447 int agent_responselen;
8448 unsigned char *pkblob_in_agent;
8450 char *pkblob, *alg, *commentp;
8451 int pklen, alglen, commentlen;
8452 int siglen, retlen, len;
8453 char *q, *agentreq, *ret;
8455 struct Packet *pktout;
8458 struct ssh_gss_library *gsslib;
8459 Ssh_gss_ctx gss_ctx;
8460 Ssh_gss_buf gss_buf;
8461 Ssh_gss_buf gss_rcvtok, gss_sndtok;
8462 Ssh_gss_name gss_srv_name;
8463 Ssh_gss_stat gss_stat;
8466 crState(do_ssh2_authconn_state);
8470 /* Register as a handler for all the messages this coroutine handles. */
8471 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
8472 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
8473 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
8474 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
8475 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
8476 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
8477 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
8478 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
8479 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
8480 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
8481 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
8482 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
8483 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
8484 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
8485 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
8486 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
8487 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
8488 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
8489 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
8490 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
8492 s->done_service_req = FALSE;
8493 s->we_are_in = s->userauth_success = FALSE;
8494 s->agent_response = NULL;
8496 s->tried_gssapi = FALSE;
8499 if (!ssh->bare_connection) {
8500 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
8502 * Request userauth protocol, and await a response to it.
8504 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8505 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
8506 ssh2_pkt_send(ssh, s->pktout);
8507 crWaitUntilV(pktin);
8508 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
8509 s->done_service_req = TRUE;
8511 if (!s->done_service_req) {
8513 * Request connection protocol directly, without authentication.
8515 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8516 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8517 ssh2_pkt_send(ssh, s->pktout);
8518 crWaitUntilV(pktin);
8519 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
8520 s->we_are_in = TRUE; /* no auth required */
8522 bombout(("Server refused service request"));
8527 s->we_are_in = TRUE;
8530 /* Arrange to be able to deal with any BANNERs that come in.
8531 * (We do this now as packets may come in during the next bit.) */
8532 bufchain_init(&ssh->banner);
8533 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
8534 ssh2_msg_userauth_banner;
8537 * Misc one-time setup for authentication.
8539 s->publickey_blob = NULL;
8540 if (!s->we_are_in) {
8543 * Load the public half of any configured public key file
8546 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
8547 if (!filename_is_null(s->keyfile)) {
8549 logeventf(ssh, "Reading private key file \"%.150s\"",
8550 filename_to_str(s->keyfile));
8551 keytype = key_type(s->keyfile);
8552 if (keytype == SSH_KEYTYPE_SSH2) {
8555 ssh2_userkey_loadpub(s->keyfile,
8556 &s->publickey_algorithm,
8557 &s->publickey_bloblen,
8558 &s->publickey_comment, &error);
8559 if (s->publickey_blob) {
8560 s->publickey_encrypted =
8561 ssh2_userkey_encrypted(s->keyfile, NULL);
8564 logeventf(ssh, "Unable to load private key (%s)",
8566 msgbuf = dupprintf("Unable to load private key file "
8567 "\"%.150s\" (%s)\r\n",
8568 filename_to_str(s->keyfile),
8570 c_write_str(ssh, msgbuf);
8575 logeventf(ssh, "Unable to use this key file (%s)",
8576 key_type_to_str(keytype));
8577 msgbuf = dupprintf("Unable to use key file \"%.150s\""
8579 filename_to_str(s->keyfile),
8580 key_type_to_str(keytype));
8581 c_write_str(ssh, msgbuf);
8583 s->publickey_blob = NULL;
8588 * Find out about any keys Pageant has (but if there's a
8589 * public key configured, filter out all others).
8592 s->agent_response = NULL;
8593 s->pkblob_in_agent = NULL;
8594 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
8598 logevent("Pageant is running. Requesting keys.");
8600 /* Request the keys held by the agent. */
8601 PUT_32BIT(s->agent_request, 1);
8602 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
8603 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
8604 ssh_agent_callback, ssh)) {
8608 bombout(("Unexpected data from server while"
8609 " waiting for agent response"));
8612 } while (pktin || inlen > 0);
8613 r = ssh->agent_response;
8614 s->agent_responselen = ssh->agent_response_len;
8616 s->agent_response = (unsigned char *) r;
8617 if (s->agent_response && s->agent_responselen >= 5 &&
8618 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
8621 p = s->agent_response + 5;
8622 s->nkeys = toint(GET_32BIT(p));
8625 * Vet the Pageant response to ensure that the key
8626 * count and blob lengths make sense.
8629 logeventf(ssh, "Pageant response contained a negative"
8630 " key count %d", s->nkeys);
8632 goto done_agent_query;
8634 unsigned char *q = p + 4;
8635 int lenleft = s->agent_responselen - 5 - 4;
8637 for (keyi = 0; keyi < s->nkeys; keyi++) {
8638 int bloblen, commentlen;
8640 logeventf(ssh, "Pageant response was truncated");
8642 goto done_agent_query;
8644 bloblen = toint(GET_32BIT(q));
8645 if (bloblen < 0 || bloblen > lenleft) {
8646 logeventf(ssh, "Pageant response was truncated");
8648 goto done_agent_query;
8650 lenleft -= 4 + bloblen;
8652 commentlen = toint(GET_32BIT(q));
8653 if (commentlen < 0 || commentlen > lenleft) {
8654 logeventf(ssh, "Pageant response was truncated");
8656 goto done_agent_query;
8658 lenleft -= 4 + commentlen;
8659 q += 4 + commentlen;
8664 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
8665 if (s->publickey_blob) {
8666 /* See if configured key is in agent. */
8667 for (keyi = 0; keyi < s->nkeys; keyi++) {
8668 s->pklen = toint(GET_32BIT(p));
8669 if (s->pklen == s->publickey_bloblen &&
8670 !memcmp(p+4, s->publickey_blob,
8671 s->publickey_bloblen)) {
8672 logeventf(ssh, "Pageant key #%d matches "
8673 "configured key file", keyi);
8675 s->pkblob_in_agent = p;
8679 p += toint(GET_32BIT(p)) + 4; /* comment */
8681 if (!s->pkblob_in_agent) {
8682 logevent("Configured key file not in Pageant");
8687 logevent("Failed to get reply from Pageant");
8695 * We repeat this whole loop, including the username prompt,
8696 * until we manage a successful authentication. If the user
8697 * types the wrong _password_, they can be sent back to the
8698 * beginning to try another username, if this is configured on.
8699 * (If they specify a username in the config, they are never
8700 * asked, even if they do give a wrong password.)
8702 * I think this best serves the needs of
8704 * - the people who have no configuration, no keys, and just
8705 * want to try repeated (username,password) pairs until they
8706 * type both correctly
8708 * - people who have keys and configuration but occasionally
8709 * need to fall back to passwords
8711 * - people with a key held in Pageant, who might not have
8712 * logged in to a particular machine before; so they want to
8713 * type a username, and then _either_ their key will be
8714 * accepted, _or_ they will type a password. If they mistype
8715 * the username they will want to be able to get back and
8718 s->got_username = FALSE;
8719 while (!s->we_are_in) {
8723 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
8725 * We got a username last time round this loop, and
8726 * with change_username turned off we don't try to get
8729 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
8730 int ret; /* need not be kept over crReturn */
8731 s->cur_prompt = new_prompts(ssh->frontend);
8732 s->cur_prompt->to_server = TRUE;
8733 s->cur_prompt->name = dupstr("SSH login name");
8734 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
8735 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8738 crWaitUntilV(!pktin);
8739 ret = get_userpass_input(s->cur_prompt, in, inlen);
8744 * get_userpass_input() failed to get a username.
8747 free_prompts(s->cur_prompt);
8748 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
8751 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
8752 free_prompts(s->cur_prompt);
8755 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
8756 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
8757 c_write_str(ssh, stuff);
8761 s->got_username = TRUE;
8764 * Send an authentication request using method "none": (a)
8765 * just in case it succeeds, and (b) so that we know what
8766 * authentication methods we can usefully try next.
8768 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
8770 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8771 ssh2_pkt_addstring(s->pktout, ssh->username);
8772 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
8773 ssh2_pkt_addstring(s->pktout, "none"); /* method */
8774 ssh2_pkt_send(ssh, s->pktout);
8775 s->type = AUTH_TYPE_NONE;
8777 s->we_are_in = FALSE;
8779 s->tried_pubkey_config = FALSE;
8780 s->kbd_inter_refused = FALSE;
8782 /* Reset agent request state. */
8783 s->done_agent = FALSE;
8784 if (s->agent_response) {
8785 if (s->pkblob_in_agent) {
8786 s->agentp = s->pkblob_in_agent;
8788 s->agentp = s->agent_response + 5 + 4;
8794 char *methods = NULL;
8798 * Wait for the result of the last authentication request.
8801 crWaitUntilV(pktin);
8803 * Now is a convenient point to spew any banner material
8804 * that we've accumulated. (This should ensure that when
8805 * we exit the auth loop, we haven't any left to deal
8809 int size = bufchain_size(&ssh->banner);
8811 * Don't show the banner if we're operating in
8812 * non-verbose non-interactive mode. (It's probably
8813 * a script, which means nobody will read the
8814 * banner _anyway_, and moreover the printing of
8815 * the banner will screw up processing on the
8816 * output of (say) plink.)
8818 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
8819 char *banner = snewn(size, char);
8820 bufchain_fetch(&ssh->banner, banner, size);
8821 c_write_untrusted(ssh, banner, size);
8824 bufchain_clear(&ssh->banner);
8826 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
8827 logevent("Access granted");
8828 s->we_are_in = s->userauth_success = TRUE;
8832 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
8833 bombout(("Strange packet received during authentication: "
8834 "type %d", pktin->type));
8841 * OK, we're now sitting on a USERAUTH_FAILURE message, so
8842 * we can look at the string in it and know what we can
8843 * helpfully try next.
8845 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
8846 ssh_pkt_getstring(pktin, &methods, &methlen);
8847 if (!ssh2_pkt_getbool(pktin)) {
8849 * We have received an unequivocal Access
8850 * Denied. This can translate to a variety of
8851 * messages, or no message at all.
8853 * For forms of authentication which are attempted
8854 * implicitly, by which I mean without printing
8855 * anything in the window indicating that we're
8856 * trying them, we should never print 'Access
8859 * If we do print a message saying that we're
8860 * attempting some kind of authentication, it's OK
8861 * to print a followup message saying it failed -
8862 * but the message may sometimes be more specific
8863 * than simply 'Access denied'.
8865 * Additionally, if we'd just tried password
8866 * authentication, we should break out of this
8867 * whole loop so as to go back to the username
8868 * prompt (iff we're configured to allow
8869 * username change attempts).
8871 if (s->type == AUTH_TYPE_NONE) {
8873 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
8874 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
8875 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
8876 c_write_str(ssh, "Server refused our key\r\n");
8877 logevent("Server refused our key");
8878 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
8879 /* This _shouldn't_ happen except by a
8880 * protocol bug causing client and server to
8881 * disagree on what is a correct signature. */
8882 c_write_str(ssh, "Server refused public-key signature"
8883 " despite accepting key!\r\n");
8884 logevent("Server refused public-key signature"
8885 " despite accepting key!");
8886 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
8887 /* quiet, so no c_write */
8888 logevent("Server refused keyboard-interactive authentication");
8889 } else if (s->type==AUTH_TYPE_GSSAPI) {
8890 /* always quiet, so no c_write */
8891 /* also, the code down in the GSSAPI block has
8892 * already logged this in the Event Log */
8893 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
8894 logevent("Keyboard-interactive authentication failed");
8895 c_write_str(ssh, "Access denied\r\n");
8897 assert(s->type == AUTH_TYPE_PASSWORD);
8898 logevent("Password authentication failed");
8899 c_write_str(ssh, "Access denied\r\n");
8901 if (conf_get_int(ssh->conf, CONF_change_username)) {
8902 /* XXX perhaps we should allow
8903 * keyboard-interactive to do this too? */
8904 s->we_are_in = FALSE;
8909 c_write_str(ssh, "Further authentication required\r\n");
8910 logevent("Further authentication required");
8914 in_commasep_string("publickey", methods, methlen);
8916 in_commasep_string("password", methods, methlen);
8917 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
8918 in_commasep_string("keyboard-interactive", methods, methlen);
8921 ssh->gsslibs = ssh_gss_setup(ssh->conf);
8922 s->can_gssapi = conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
8923 in_commasep_string("gssapi-with-mic", methods, methlen) &&
8924 ssh->gsslibs->nlibraries > 0;
8928 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
8930 if (s->can_pubkey && !s->done_agent && s->nkeys) {
8933 * Attempt public-key authentication using a key from Pageant.
8936 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
8938 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
8940 /* Unpack key from agent response */
8941 s->pklen = toint(GET_32BIT(s->agentp));
8943 s->pkblob = (char *)s->agentp;
8944 s->agentp += s->pklen;
8945 s->alglen = toint(GET_32BIT(s->pkblob));
8946 s->alg = s->pkblob + 4;
8947 s->commentlen = toint(GET_32BIT(s->agentp));
8949 s->commentp = (char *)s->agentp;
8950 s->agentp += s->commentlen;
8951 /* s->agentp now points at next key, if any */
8953 /* See if server will accept it */
8954 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8955 ssh2_pkt_addstring(s->pktout, ssh->username);
8956 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8957 /* service requested */
8958 ssh2_pkt_addstring(s->pktout, "publickey");
8960 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
8961 ssh2_pkt_addstring_start(s->pktout);
8962 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
8963 ssh2_pkt_addstring_start(s->pktout);
8964 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
8965 ssh2_pkt_send(ssh, s->pktout);
8966 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
8968 crWaitUntilV(pktin);
8969 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
8971 /* Offer of key refused. */
8978 if (flags & FLAG_VERBOSE) {
8979 c_write_str(ssh, "Authenticating with "
8981 c_write(ssh, s->commentp, s->commentlen);
8982 c_write_str(ssh, "\" from agent\r\n");
8986 * Server is willing to accept the key.
8987 * Construct a SIGN_REQUEST.
8989 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8990 ssh2_pkt_addstring(s->pktout, ssh->username);
8991 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8992 /* service requested */
8993 ssh2_pkt_addstring(s->pktout, "publickey");
8995 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
8996 ssh2_pkt_addstring_start(s->pktout);
8997 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
8998 ssh2_pkt_addstring_start(s->pktout);
8999 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9001 /* Ask agent for signature. */
9002 s->siglen = s->pktout->length - 5 + 4 +
9003 ssh->v2_session_id_len;
9004 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9006 s->len = 1; /* message type */
9007 s->len += 4 + s->pklen; /* key blob */
9008 s->len += 4 + s->siglen; /* data to sign */
9009 s->len += 4; /* flags */
9010 s->agentreq = snewn(4 + s->len, char);
9011 PUT_32BIT(s->agentreq, s->len);
9012 s->q = s->agentreq + 4;
9013 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
9014 PUT_32BIT(s->q, s->pklen);
9016 memcpy(s->q, s->pkblob, s->pklen);
9018 PUT_32BIT(s->q, s->siglen);
9020 /* Now the data to be signed... */
9021 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9022 PUT_32BIT(s->q, ssh->v2_session_id_len);
9025 memcpy(s->q, ssh->v2_session_id,
9026 ssh->v2_session_id_len);
9027 s->q += ssh->v2_session_id_len;
9028 memcpy(s->q, s->pktout->data + 5,
9029 s->pktout->length - 5);
9030 s->q += s->pktout->length - 5;
9031 /* And finally the (zero) flags word. */
9033 if (!agent_query(s->agentreq, s->len + 4,
9035 ssh_agent_callback, ssh)) {
9039 bombout(("Unexpected data from server"
9040 " while waiting for agent"
9044 } while (pktin || inlen > 0);
9045 vret = ssh->agent_response;
9046 s->retlen = ssh->agent_response_len;
9051 if (s->retlen >= 9 &&
9052 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
9053 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
9054 logevent("Sending Pageant's response");
9055 ssh2_add_sigblob(ssh, s->pktout,
9056 s->pkblob, s->pklen,
9058 GET_32BIT(s->ret + 5));
9059 ssh2_pkt_send(ssh, s->pktout);
9060 s->type = AUTH_TYPE_PUBLICKEY;
9062 /* FIXME: less drastic response */
9063 bombout(("Pageant failed to answer challenge"));
9069 /* Do we have any keys left to try? */
9070 if (s->pkblob_in_agent) {
9071 s->done_agent = TRUE;
9072 s->tried_pubkey_config = TRUE;
9075 if (s->keyi >= s->nkeys)
9076 s->done_agent = TRUE;
9079 } else if (s->can_pubkey && s->publickey_blob &&
9080 !s->tried_pubkey_config) {
9082 struct ssh2_userkey *key; /* not live over crReturn */
9083 char *passphrase; /* not live over crReturn */
9085 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9087 s->tried_pubkey_config = TRUE;
9090 * Try the public key supplied in the configuration.
9092 * First, offer the public blob to see if the server is
9093 * willing to accept it.
9095 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9096 ssh2_pkt_addstring(s->pktout, ssh->username);
9097 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9098 /* service requested */
9099 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
9100 ssh2_pkt_addbool(s->pktout, FALSE);
9101 /* no signature included */
9102 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
9103 ssh2_pkt_addstring_start(s->pktout);
9104 ssh2_pkt_addstring_data(s->pktout,
9105 (char *)s->publickey_blob,
9106 s->publickey_bloblen);
9107 ssh2_pkt_send(ssh, s->pktout);
9108 logevent("Offered public key");
9110 crWaitUntilV(pktin);
9111 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9112 /* Key refused. Give up. */
9113 s->gotit = TRUE; /* reconsider message next loop */
9114 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
9115 continue; /* process this new message */
9117 logevent("Offer of public key accepted");
9120 * Actually attempt a serious authentication using
9123 if (flags & FLAG_VERBOSE) {
9124 c_write_str(ssh, "Authenticating with public key \"");
9125 c_write_str(ssh, s->publickey_comment);
9126 c_write_str(ssh, "\"\r\n");
9130 const char *error; /* not live over crReturn */
9131 if (s->publickey_encrypted) {
9133 * Get a passphrase from the user.
9135 int ret; /* need not be kept over crReturn */
9136 s->cur_prompt = new_prompts(ssh->frontend);
9137 s->cur_prompt->to_server = FALSE;
9138 s->cur_prompt->name = dupstr("SSH key passphrase");
9139 add_prompt(s->cur_prompt,
9140 dupprintf("Passphrase for key \"%.100s\": ",
9141 s->publickey_comment),
9143 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9146 crWaitUntilV(!pktin);
9147 ret = get_userpass_input(s->cur_prompt,
9152 /* Failed to get a passphrase. Terminate. */
9153 free_prompts(s->cur_prompt);
9154 ssh_disconnect(ssh, NULL,
9155 "Unable to authenticate",
9156 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9161 dupstr(s->cur_prompt->prompts[0]->result);
9162 free_prompts(s->cur_prompt);
9164 passphrase = NULL; /* no passphrase needed */
9168 * Try decrypting the key.
9170 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9171 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
9173 /* burn the evidence */
9174 smemclr(passphrase, strlen(passphrase));
9177 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
9179 (key == SSH2_WRONG_PASSPHRASE)) {
9180 c_write_str(ssh, "Wrong passphrase\r\n");
9182 /* and loop again */
9184 c_write_str(ssh, "Unable to load private key (");
9185 c_write_str(ssh, error);
9186 c_write_str(ssh, ")\r\n");
9188 break; /* try something else */
9194 unsigned char *pkblob, *sigblob, *sigdata;
9195 int pkblob_len, sigblob_len, sigdata_len;
9199 * We have loaded the private key and the server
9200 * has announced that it's willing to accept it.
9201 * Hallelujah. Generate a signature and send it.
9203 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9204 ssh2_pkt_addstring(s->pktout, ssh->username);
9205 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9206 /* service requested */
9207 ssh2_pkt_addstring(s->pktout, "publickey");
9209 ssh2_pkt_addbool(s->pktout, TRUE);
9210 /* signature follows */
9211 ssh2_pkt_addstring(s->pktout, key->alg->name);
9212 pkblob = key->alg->public_blob(key->data,
9214 ssh2_pkt_addstring_start(s->pktout);
9215 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
9219 * The data to be signed is:
9223 * followed by everything so far placed in the
9226 sigdata_len = s->pktout->length - 5 + 4 +
9227 ssh->v2_session_id_len;
9228 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9230 sigdata = snewn(sigdata_len, unsigned char);
9232 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9233 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
9236 memcpy(sigdata+p, ssh->v2_session_id,
9237 ssh->v2_session_id_len);
9238 p += ssh->v2_session_id_len;
9239 memcpy(sigdata+p, s->pktout->data + 5,
9240 s->pktout->length - 5);
9241 p += s->pktout->length - 5;
9242 assert(p == sigdata_len);
9243 sigblob = key->alg->sign(key->data, (char *)sigdata,
9244 sigdata_len, &sigblob_len);
9245 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
9246 sigblob, sigblob_len);
9251 ssh2_pkt_send(ssh, s->pktout);
9252 logevent("Sent public key signature");
9253 s->type = AUTH_TYPE_PUBLICKEY;
9254 key->alg->freekey(key->data);
9258 } else if (s->can_gssapi && !s->tried_gssapi) {
9260 /* GSSAPI Authentication */
9265 s->type = AUTH_TYPE_GSSAPI;
9266 s->tried_gssapi = TRUE;
9268 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
9271 * Pick the highest GSS library on the preference
9277 for (i = 0; i < ngsslibs; i++) {
9278 int want_id = conf_get_int_int(ssh->conf,
9279 CONF_ssh_gsslist, i);
9280 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
9281 if (ssh->gsslibs->libraries[j].id == want_id) {
9282 s->gsslib = &ssh->gsslibs->libraries[j];
9283 goto got_gsslib; /* double break */
9288 * We always expect to have found something in
9289 * the above loop: we only came here if there
9290 * was at least one viable GSS library, and the
9291 * preference list should always mention
9292 * everything and only change the order.
9297 if (s->gsslib->gsslogmsg)
9298 logevent(s->gsslib->gsslogmsg);
9300 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
9301 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9302 ssh2_pkt_addstring(s->pktout, ssh->username);
9303 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9304 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
9305 logevent("Attempting GSSAPI authentication");
9307 /* add mechanism info */
9308 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
9310 /* number of GSSAPI mechanisms */
9311 ssh2_pkt_adduint32(s->pktout,1);
9313 /* length of OID + 2 */
9314 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
9315 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
9318 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
9320 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
9322 ssh2_pkt_send(ssh, s->pktout);
9323 crWaitUntilV(pktin);
9324 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
9325 logevent("GSSAPI authentication request refused");
9329 /* check returned packet ... */
9331 ssh_pkt_getstring(pktin, &data, &len);
9332 s->gss_rcvtok.value = data;
9333 s->gss_rcvtok.length = len;
9334 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
9335 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
9336 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
9337 memcmp((char *)s->gss_rcvtok.value + 2,
9338 s->gss_buf.value,s->gss_buf.length) ) {
9339 logevent("GSSAPI authentication - wrong response from server");
9343 /* now start running */
9344 s->gss_stat = s->gsslib->import_name(s->gsslib,
9347 if (s->gss_stat != SSH_GSS_OK) {
9348 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
9349 logevent("GSSAPI import name failed - Bad service name");
9351 logevent("GSSAPI import name failed");
9355 /* fetch TGT into GSS engine */
9356 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
9358 if (s->gss_stat != SSH_GSS_OK) {
9359 logevent("GSSAPI authentication failed to get credentials");
9360 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9364 /* initial tokens are empty */
9365 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
9366 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
9368 /* now enter the loop */
9370 s->gss_stat = s->gsslib->init_sec_context
9374 conf_get_int(ssh->conf, CONF_gssapifwd),
9378 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
9379 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
9380 logevent("GSSAPI authentication initialisation failed");
9382 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
9383 &s->gss_buf) == SSH_GSS_OK) {
9384 logevent(s->gss_buf.value);
9385 sfree(s->gss_buf.value);
9390 logevent("GSSAPI authentication initialised");
9392 /* Client and server now exchange tokens until GSSAPI
9393 * no longer says CONTINUE_NEEDED */
9395 if (s->gss_sndtok.length != 0) {
9396 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
9397 ssh_pkt_addstring_start(s->pktout);
9398 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
9399 ssh2_pkt_send(ssh, s->pktout);
9400 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
9403 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
9404 crWaitUntilV(pktin);
9405 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
9406 logevent("GSSAPI authentication - bad server response");
9407 s->gss_stat = SSH_GSS_FAILURE;
9410 ssh_pkt_getstring(pktin, &data, &len);
9411 s->gss_rcvtok.value = data;
9412 s->gss_rcvtok.length = len;
9414 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
9416 if (s->gss_stat != SSH_GSS_OK) {
9417 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9418 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9421 logevent("GSSAPI authentication loop finished OK");
9423 /* Now send the MIC */
9425 s->pktout = ssh2_pkt_init(0);
9426 micoffset = s->pktout->length;
9427 ssh_pkt_addstring_start(s->pktout);
9428 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
9429 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
9430 ssh_pkt_addstring(s->pktout, ssh->username);
9431 ssh_pkt_addstring(s->pktout, "ssh-connection");
9432 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
9434 s->gss_buf.value = (char *)s->pktout->data + micoffset;
9435 s->gss_buf.length = s->pktout->length - micoffset;
9437 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
9438 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
9439 ssh_pkt_addstring_start(s->pktout);
9440 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
9441 ssh2_pkt_send(ssh, s->pktout);
9442 s->gsslib->free_mic(s->gsslib, &mic);
9446 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9447 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9450 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
9453 * Keyboard-interactive authentication.
9456 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
9458 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
9460 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9461 ssh2_pkt_addstring(s->pktout, ssh->username);
9462 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9463 /* service requested */
9464 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
9466 ssh2_pkt_addstring(s->pktout, ""); /* lang */
9467 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
9468 ssh2_pkt_send(ssh, s->pktout);
9470 logevent("Attempting keyboard-interactive authentication");
9472 crWaitUntilV(pktin);
9473 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
9474 /* Server is not willing to do keyboard-interactive
9475 * at all (or, bizarrely but legally, accepts the
9476 * user without actually issuing any prompts).
9477 * Give up on it entirely. */
9479 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
9480 s->kbd_inter_refused = TRUE; /* don't try it again */
9485 * Loop while the server continues to send INFO_REQUESTs.
9487 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
9489 char *name, *inst, *lang;
9490 int name_len, inst_len, lang_len;
9494 * We've got a fresh USERAUTH_INFO_REQUEST.
9495 * Get the preamble and start building a prompt.
9497 ssh_pkt_getstring(pktin, &name, &name_len);
9498 ssh_pkt_getstring(pktin, &inst, &inst_len);
9499 ssh_pkt_getstring(pktin, &lang, &lang_len);
9500 s->cur_prompt = new_prompts(ssh->frontend);
9501 s->cur_prompt->to_server = TRUE;
9504 * Get any prompt(s) from the packet.
9506 s->num_prompts = ssh_pkt_getuint32(pktin);
9507 for (i = 0; i < s->num_prompts; i++) {
9511 static char noprompt[] =
9512 "<server failed to send prompt>: ";
9514 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9515 echo = ssh2_pkt_getbool(pktin);
9518 prompt_len = lenof(noprompt)-1;
9520 add_prompt(s->cur_prompt,
9521 dupprintf("%.*s", prompt_len, prompt),
9526 /* FIXME: better prefix to distinguish from
9528 s->cur_prompt->name =
9529 dupprintf("SSH server: %.*s", name_len, name);
9530 s->cur_prompt->name_reqd = TRUE;
9532 s->cur_prompt->name =
9533 dupstr("SSH server authentication");
9534 s->cur_prompt->name_reqd = FALSE;
9536 /* We add a prefix to try to make it clear that a prompt
9537 * has come from the server.
9538 * FIXME: ugly to print "Using..." in prompt _every_
9539 * time round. Can this be done more subtly? */
9540 /* Special case: for reasons best known to themselves,
9541 * some servers send k-i requests with no prompts and
9542 * nothing to display. Keep quiet in this case. */
9543 if (s->num_prompts || name_len || inst_len) {
9544 s->cur_prompt->instruction =
9545 dupprintf("Using keyboard-interactive authentication.%s%.*s",
9546 inst_len ? "\n" : "", inst_len, inst);
9547 s->cur_prompt->instr_reqd = TRUE;
9549 s->cur_prompt->instr_reqd = FALSE;
9553 * Display any instructions, and get the user's
9557 int ret; /* not live over crReturn */
9558 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9561 crWaitUntilV(!pktin);
9562 ret = get_userpass_input(s->cur_prompt, in, inlen);
9567 * Failed to get responses. Terminate.
9569 free_prompts(s->cur_prompt);
9570 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9571 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9578 * Send the response(s) to the server.
9580 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
9581 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
9582 for (i=0; i < s->num_prompts; i++) {
9583 ssh2_pkt_addstring(s->pktout,
9584 s->cur_prompt->prompts[i]->result);
9586 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9589 * Free the prompts structure from this iteration.
9590 * If there's another, a new one will be allocated
9591 * when we return to the top of this while loop.
9593 free_prompts(s->cur_prompt);
9596 * Get the next packet in case it's another
9599 crWaitUntilV(pktin);
9604 * We should have SUCCESS or FAILURE now.
9608 } else if (s->can_passwd) {
9611 * Plain old password authentication.
9613 int ret; /* not live over crReturn */
9614 int changereq_first_time; /* not live over crReturn */
9616 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
9618 s->cur_prompt = new_prompts(ssh->frontend);
9619 s->cur_prompt->to_server = TRUE;
9620 s->cur_prompt->name = dupstr("SSH password");
9621 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
9626 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9629 crWaitUntilV(!pktin);
9630 ret = get_userpass_input(s->cur_prompt, in, inlen);
9635 * Failed to get responses. Terminate.
9637 free_prompts(s->cur_prompt);
9638 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9639 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9644 * Squirrel away the password. (We may need it later if
9645 * asked to change it.)
9647 s->password = dupstr(s->cur_prompt->prompts[0]->result);
9648 free_prompts(s->cur_prompt);
9651 * Send the password packet.
9653 * We pad out the password packet to 256 bytes to make
9654 * it harder for an attacker to find the length of the
9657 * Anyone using a password longer than 256 bytes
9658 * probably doesn't have much to worry about from
9659 * people who find out how long their password is!
9661 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9662 ssh2_pkt_addstring(s->pktout, ssh->username);
9663 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9664 /* service requested */
9665 ssh2_pkt_addstring(s->pktout, "password");
9666 ssh2_pkt_addbool(s->pktout, FALSE);
9667 ssh2_pkt_addstring(s->pktout, s->password);
9668 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9669 logevent("Sent password");
9670 s->type = AUTH_TYPE_PASSWORD;
9673 * Wait for next packet, in case it's a password change
9676 crWaitUntilV(pktin);
9677 changereq_first_time = TRUE;
9679 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
9682 * We're being asked for a new password
9683 * (perhaps not for the first time).
9684 * Loop until the server accepts it.
9687 int got_new = FALSE; /* not live over crReturn */
9688 char *prompt; /* not live over crReturn */
9689 int prompt_len; /* not live over crReturn */
9693 if (changereq_first_time)
9694 msg = "Server requested password change";
9696 msg = "Server rejected new password";
9698 c_write_str(ssh, msg);
9699 c_write_str(ssh, "\r\n");
9702 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9704 s->cur_prompt = new_prompts(ssh->frontend);
9705 s->cur_prompt->to_server = TRUE;
9706 s->cur_prompt->name = dupstr("New SSH password");
9707 s->cur_prompt->instruction =
9708 dupprintf("%.*s", prompt_len, prompt);
9709 s->cur_prompt->instr_reqd = TRUE;
9711 * There's no explicit requirement in the protocol
9712 * for the "old" passwords in the original and
9713 * password-change messages to be the same, and
9714 * apparently some Cisco kit supports password change
9715 * by the user entering a blank password originally
9716 * and the real password subsequently, so,
9717 * reluctantly, we prompt for the old password again.
9719 * (On the other hand, some servers don't even bother
9720 * to check this field.)
9722 add_prompt(s->cur_prompt,
9723 dupstr("Current password (blank for previously entered password): "),
9725 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
9727 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
9731 * Loop until the user manages to enter the same
9736 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9739 crWaitUntilV(!pktin);
9740 ret = get_userpass_input(s->cur_prompt, in, inlen);
9745 * Failed to get responses. Terminate.
9747 /* burn the evidence */
9748 free_prompts(s->cur_prompt);
9749 smemclr(s->password, strlen(s->password));
9751 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9752 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9758 * If the user specified a new original password
9759 * (IYSWIM), overwrite any previously specified
9761 * (A side effect is that the user doesn't have to
9762 * re-enter it if they louse up the new password.)
9764 if (s->cur_prompt->prompts[0]->result[0]) {
9765 smemclr(s->password, strlen(s->password));
9766 /* burn the evidence */
9769 dupstr(s->cur_prompt->prompts[0]->result);
9773 * Check the two new passwords match.
9775 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
9776 s->cur_prompt->prompts[2]->result)
9779 /* They don't. Silly user. */
9780 c_write_str(ssh, "Passwords do not match\r\n");
9785 * Send the new password (along with the old one).
9786 * (see above for padding rationale)
9788 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9789 ssh2_pkt_addstring(s->pktout, ssh->username);
9790 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9791 /* service requested */
9792 ssh2_pkt_addstring(s->pktout, "password");
9793 ssh2_pkt_addbool(s->pktout, TRUE);
9794 ssh2_pkt_addstring(s->pktout, s->password);
9795 ssh2_pkt_addstring(s->pktout,
9796 s->cur_prompt->prompts[1]->result);
9797 free_prompts(s->cur_prompt);
9798 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9799 logevent("Sent new password");
9802 * Now see what the server has to say about it.
9803 * (If it's CHANGEREQ again, it's not happy with the
9806 crWaitUntilV(pktin);
9807 changereq_first_time = FALSE;
9812 * We need to reexamine the current pktin at the top
9813 * of the loop. Either:
9814 * - we weren't asked to change password at all, in
9815 * which case it's a SUCCESS or FAILURE with the
9817 * - we sent a new password, and the server was
9818 * either OK with it (SUCCESS or FAILURE w/partial
9819 * success) or unhappy with the _old_ password
9820 * (FAILURE w/o partial success)
9821 * In any of these cases, we go back to the top of
9822 * the loop and start again.
9827 * We don't need the old password any more, in any
9828 * case. Burn the evidence.
9830 smemclr(s->password, strlen(s->password));
9834 char *str = dupprintf("No supported authentication methods available"
9835 " (server sent: %.*s)",
9838 ssh_disconnect(ssh, str,
9839 "No supported authentication methods available",
9840 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
9850 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
9852 /* Clear up various bits and pieces from authentication. */
9853 if (s->publickey_blob) {
9854 sfree(s->publickey_blob);
9855 sfree(s->publickey_comment);
9857 if (s->agent_response)
9858 sfree(s->agent_response);
9860 if (s->userauth_success && !ssh->bare_connection) {
9862 * We've just received USERAUTH_SUCCESS, and we haven't sent any
9863 * packets since. Signal the transport layer to consider enacting
9864 * delayed compression.
9866 * (Relying on we_are_in is not sufficient, as
9867 * draft-miller-secsh-compression-delayed is quite clear that it
9868 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
9869 * become set for other reasons.)
9871 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
9874 ssh->channels = newtree234(ssh_channelcmp);
9877 * Set up handlers for some connection protocol messages, so we
9878 * don't have to handle them repeatedly in this coroutine.
9880 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
9881 ssh2_msg_channel_window_adjust;
9882 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
9883 ssh2_msg_global_request;
9886 * Create the main session channel.
9888 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
9889 ssh->mainchan = NULL;
9891 ssh->mainchan = snew(struct ssh_channel);
9892 ssh->mainchan->ssh = ssh;
9893 ssh2_channel_init(ssh->mainchan);
9895 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
9897 * Just start a direct-tcpip channel and use it as the main
9900 ssh_send_port_open(ssh->mainchan,
9901 conf_get_str(ssh->conf, CONF_ssh_nc_host),
9902 conf_get_int(ssh->conf, CONF_ssh_nc_port),
9906 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
9907 logevent("Opening session as main channel");
9908 ssh2_pkt_send(ssh, s->pktout);
9909 ssh->ncmode = FALSE;
9911 crWaitUntilV(pktin);
9912 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
9913 bombout(("Server refused to open channel"));
9915 /* FIXME: error data comes back in FAILURE packet */
9917 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
9918 bombout(("Server's channel confirmation cited wrong channel"));
9921 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
9922 ssh->mainchan->halfopen = FALSE;
9923 ssh->mainchan->type = CHAN_MAINSESSION;
9924 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
9925 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
9926 add234(ssh->channels, ssh->mainchan);
9927 update_specials_menu(ssh->frontend);
9928 logevent("Opened main channel");
9932 * Now we have a channel, make dispatch table entries for
9933 * general channel-based messages.
9935 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
9936 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
9937 ssh2_msg_channel_data;
9938 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
9939 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
9940 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
9941 ssh2_msg_channel_open_confirmation;
9942 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
9943 ssh2_msg_channel_open_failure;
9944 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
9945 ssh2_msg_channel_request;
9946 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
9947 ssh2_msg_channel_open;
9948 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
9949 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
9952 * Now the connection protocol is properly up and running, with
9953 * all those dispatch table entries, so it's safe to let
9954 * downstreams start trying to open extra channels through us.
9957 share_activate(ssh->connshare, ssh->v_s);
9959 if (ssh->mainchan && ssh_is_simple(ssh)) {
9961 * This message indicates to the server that we promise
9962 * not to try to run any other channel in parallel with
9963 * this one, so it's safe for it to advertise a very large
9964 * window and leave the flow control to TCP.
9966 s->pktout = ssh2_chanreq_init(ssh->mainchan,
9967 "simple@putty.projects.tartarus.org",
9969 ssh2_pkt_send(ssh, s->pktout);
9973 * Enable port forwardings.
9975 ssh_setup_portfwd(ssh, ssh->conf);
9977 if (ssh->mainchan && !ssh->ncmode) {
9979 * Send the CHANNEL_REQUESTS for the main session channel.
9980 * Each one is handled by its own little asynchronous
9984 /* Potentially enable X11 forwarding. */
9985 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
9987 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
9989 if (!ssh->x11disp) {
9990 /* FIXME: return an error message from x11_setup_display */
9991 logevent("X11 forwarding not enabled: unable to"
9992 " initialise X display");
9994 ssh->x11auth = x11_invent_fake_auth
9995 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
9996 ssh->x11auth->disp = ssh->x11disp;
9998 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
10002 /* Potentially enable agent forwarding. */
10003 if (ssh_agent_forwarding_permitted(ssh))
10004 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
10006 /* Now allocate a pty for the session. */
10007 if (!conf_get_int(ssh->conf, CONF_nopty))
10008 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
10010 /* Send environment variables. */
10011 ssh2_setup_env(ssh->mainchan, NULL, NULL);
10014 * Start a shell or a remote command. We may have to attempt
10015 * this twice if the config data has provided a second choice
10022 if (ssh->fallback_cmd) {
10023 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
10024 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
10026 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
10027 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
10031 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
10032 ssh2_response_authconn, NULL);
10033 ssh2_pkt_addstring(s->pktout, cmd);
10035 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
10036 ssh2_response_authconn, NULL);
10037 ssh2_pkt_addstring(s->pktout, cmd);
10039 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
10040 ssh2_response_authconn, NULL);
10042 ssh2_pkt_send(ssh, s->pktout);
10044 crWaitUntilV(pktin);
10046 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
10047 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
10048 bombout(("Unexpected response to shell/command request:"
10049 " packet type %d", pktin->type));
10053 * We failed to start the command. If this is the
10054 * fallback command, we really are finished; if it's
10055 * not, and if the fallback command exists, try falling
10056 * back to it before complaining.
10058 if (!ssh->fallback_cmd &&
10059 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
10060 logevent("Primary command failed; attempting fallback");
10061 ssh->fallback_cmd = TRUE;
10064 bombout(("Server refused to start a shell/command"));
10067 logevent("Started a shell/command");
10072 ssh->editing = ssh->echoing = TRUE;
10075 ssh->state = SSH_STATE_SESSION;
10076 if (ssh->size_needed)
10077 ssh_size(ssh, ssh->term_width, ssh->term_height);
10078 if (ssh->eof_needed)
10079 ssh_special(ssh, TS_EOF);
10085 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
10090 s->try_send = FALSE;
10094 * _All_ the connection-layer packets we expect to
10095 * receive are now handled by the dispatch table.
10096 * Anything that reaches here must be bogus.
10099 bombout(("Strange packet received: type %d", pktin->type));
10101 } else if (ssh->mainchan) {
10103 * We have spare data. Add it to the channel buffer.
10105 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
10106 s->try_send = TRUE;
10110 struct ssh_channel *c;
10112 * Try to send data on all channels if we can.
10114 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
10115 ssh2_try_send_and_unthrottle(ssh, c);
10123 * Handlers for SSH-2 messages that might arrive at any moment.
10125 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
10127 /* log reason code in disconnect message */
10129 int reason, msglen;
10131 reason = ssh_pkt_getuint32(pktin);
10132 ssh_pkt_getstring(pktin, &msg, &msglen);
10134 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
10135 buf = dupprintf("Received disconnect message (%s)",
10136 ssh2_disconnect_reasons[reason]);
10138 buf = dupprintf("Received disconnect message (unknown"
10139 " type %d)", reason);
10143 buf = dupprintf("Disconnection message text: %.*s",
10146 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
10148 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
10149 ssh2_disconnect_reasons[reason] : "unknown",
10154 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
10156 /* log the debug message */
10160 /* XXX maybe we should actually take notice of the return value */
10161 ssh2_pkt_getbool(pktin);
10162 ssh_pkt_getstring(pktin, &msg, &msglen);
10164 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
10167 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
10169 do_ssh2_transport(ssh, NULL, 0, pktin);
10173 * Called if we receive a packet that isn't allowed by the protocol.
10174 * This only applies to packets whose meaning PuTTY understands.
10175 * Entirely unknown packets are handled below.
10177 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
10179 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
10180 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
10182 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
10186 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
10188 struct Packet *pktout;
10189 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
10190 ssh2_pkt_adduint32(pktout, pktin->sequence);
10192 * UNIMPLEMENTED messages MUST appear in the same order as the
10193 * messages they respond to. Hence, never queue them.
10195 ssh2_pkt_send_noqueue(ssh, pktout);
10199 * Handle the top-level SSH-2 protocol.
10201 static void ssh2_protocol_setup(Ssh ssh)
10206 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10208 for (i = 0; i < 256; i++)
10209 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10212 * Initially, we only accept transport messages (and a few generic
10213 * ones). do_ssh2_authconn will add more when it starts.
10214 * Messages that are understood but not currently acceptable go to
10215 * ssh2_msg_unexpected.
10217 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10218 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
10219 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
10220 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
10221 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
10222 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
10223 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
10224 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
10225 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
10226 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
10227 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
10228 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
10229 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
10230 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
10231 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
10232 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
10233 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
10234 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
10235 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
10236 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10237 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10238 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10239 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10240 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10241 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10242 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10243 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10244 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10245 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10246 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10247 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10248 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10249 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10252 * These messages have a special handler from the start.
10254 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10255 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
10256 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10259 static void ssh2_bare_connection_protocol_setup(Ssh ssh)
10264 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10266 for (i = 0; i < 256; i++)
10267 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10270 * Initially, we set all ssh-connection messages to 'unexpected';
10271 * do_ssh2_authconn will fill things in properly. We also handle a
10272 * couple of messages from the transport protocol which aren't
10273 * related to key exchange (UNIMPLEMENTED, IGNORE, DEBUG,
10276 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10277 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10278 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10279 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10280 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10281 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10282 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10283 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10284 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10285 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10286 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10287 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10288 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10289 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10291 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10294 * These messages have a special handler from the start.
10296 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10297 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore;
10298 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10301 static void ssh2_timer(void *ctx, unsigned long now)
10303 Ssh ssh = (Ssh)ctx;
10305 if (ssh->state == SSH_STATE_CLOSED)
10308 if (!ssh->kex_in_progress && !ssh->bare_connection &&
10309 conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
10310 now == ssh->next_rekey) {
10311 do_ssh2_transport(ssh, "timeout", -1, NULL);
10315 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
10316 struct Packet *pktin)
10318 unsigned char *in = (unsigned char *)vin;
10319 if (ssh->state == SSH_STATE_CLOSED)
10323 ssh->incoming_data_size += pktin->encrypted_len;
10324 if (!ssh->kex_in_progress &&
10325 ssh->max_data_size != 0 &&
10326 ssh->incoming_data_size > ssh->max_data_size)
10327 do_ssh2_transport(ssh, "too much data received", -1, NULL);
10331 ssh->packet_dispatch[pktin->type](ssh, pktin);
10332 else if (!ssh->protocol_initial_phase_done)
10333 do_ssh2_transport(ssh, in, inlen, pktin);
10335 do_ssh2_authconn(ssh, in, inlen, pktin);
10338 static void ssh2_bare_connection_protocol(Ssh ssh, void *vin, int inlen,
10339 struct Packet *pktin)
10341 unsigned char *in = (unsigned char *)vin;
10342 if (ssh->state == SSH_STATE_CLOSED)
10346 ssh->packet_dispatch[pktin->type](ssh, pktin);
10348 do_ssh2_authconn(ssh, in, inlen, pktin);
10351 static void ssh_cache_conf_values(Ssh ssh)
10353 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
10357 * Called to set up the connection.
10359 * Returns an error message, or NULL on success.
10361 static const char *ssh_init(void *frontend_handle, void **backend_handle,
10362 Conf *conf, char *host, int port, char **realhost,
10363 int nodelay, int keepalive)
10368 ssh = snew(struct ssh_tag);
10369 ssh->conf = conf_copy(conf);
10370 ssh_cache_conf_values(ssh);
10371 ssh->version = 0; /* when not ready yet */
10373 ssh->cipher = NULL;
10374 ssh->v1_cipher_ctx = NULL;
10375 ssh->crcda_ctx = NULL;
10376 ssh->cscipher = NULL;
10377 ssh->cs_cipher_ctx = NULL;
10378 ssh->sccipher = NULL;
10379 ssh->sc_cipher_ctx = NULL;
10381 ssh->cs_mac_ctx = NULL;
10383 ssh->sc_mac_ctx = NULL;
10384 ssh->cscomp = NULL;
10385 ssh->cs_comp_ctx = NULL;
10386 ssh->sccomp = NULL;
10387 ssh->sc_comp_ctx = NULL;
10389 ssh->kex_ctx = NULL;
10390 ssh->hostkey = NULL;
10391 ssh->hostkey_str = NULL;
10392 ssh->exitcode = -1;
10393 ssh->close_expected = FALSE;
10394 ssh->clean_exit = FALSE;
10395 ssh->state = SSH_STATE_PREPACKET;
10396 ssh->size_needed = FALSE;
10397 ssh->eof_needed = FALSE;
10399 ssh->logctx = NULL;
10400 ssh->deferred_send_data = NULL;
10401 ssh->deferred_len = 0;
10402 ssh->deferred_size = 0;
10403 ssh->fallback_cmd = 0;
10404 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
10405 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
10406 ssh->x11disp = NULL;
10407 ssh->x11auth = NULL;
10408 ssh->x11authtree = newtree234(x11_authcmp);
10409 ssh->v1_compressing = FALSE;
10410 ssh->v2_outgoing_sequence = 0;
10411 ssh->ssh1_rdpkt_crstate = 0;
10412 ssh->ssh2_rdpkt_crstate = 0;
10413 ssh->ssh2_bare_rdpkt_crstate = 0;
10414 ssh->ssh_gotdata_crstate = 0;
10415 ssh->do_ssh1_connection_crstate = 0;
10416 ssh->do_ssh_init_state = NULL;
10417 ssh->do_ssh_connection_init_state = NULL;
10418 ssh->do_ssh1_login_state = NULL;
10419 ssh->do_ssh2_transport_state = NULL;
10420 ssh->do_ssh2_authconn_state = NULL;
10423 ssh->mainchan = NULL;
10424 ssh->throttled_all = 0;
10425 ssh->v1_stdout_throttling = 0;
10427 ssh->queuelen = ssh->queuesize = 0;
10428 ssh->queueing = FALSE;
10429 ssh->qhead = ssh->qtail = NULL;
10430 ssh->deferred_rekey_reason = NULL;
10431 bufchain_init(&ssh->queued_incoming_data);
10432 ssh->frozen = FALSE;
10433 ssh->username = NULL;
10434 ssh->sent_console_eof = FALSE;
10435 ssh->got_pty = FALSE;
10436 ssh->bare_connection = FALSE;
10437 ssh->attempting_connshare = FALSE;
10439 *backend_handle = ssh;
10442 if (crypto_startup() == 0)
10443 return "Microsoft high encryption pack not installed!";
10446 ssh->frontend = frontend_handle;
10447 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
10448 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
10450 ssh->channels = NULL;
10451 ssh->rportfwds = NULL;
10452 ssh->portfwds = NULL;
10457 ssh->conn_throttle_count = 0;
10458 ssh->overall_bufsize = 0;
10459 ssh->fallback_cmd = 0;
10461 ssh->protocol = NULL;
10463 ssh->protocol_initial_phase_done = FALSE;
10465 ssh->pinger = NULL;
10467 ssh->incoming_data_size = ssh->outgoing_data_size =
10468 ssh->deferred_data_size = 0L;
10469 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10470 CONF_ssh_rekey_data));
10471 ssh->kex_in_progress = FALSE;
10474 ssh->gsslibs = NULL;
10477 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
10486 static void ssh_free(void *handle)
10488 Ssh ssh = (Ssh) handle;
10489 struct ssh_channel *c;
10490 struct ssh_rportfwd *pf;
10491 struct X11FakeAuth *auth;
10493 if (ssh->v1_cipher_ctx)
10494 ssh->cipher->free_context(ssh->v1_cipher_ctx);
10495 if (ssh->cs_cipher_ctx)
10496 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
10497 if (ssh->sc_cipher_ctx)
10498 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
10499 if (ssh->cs_mac_ctx)
10500 ssh->csmac->free_context(ssh->cs_mac_ctx);
10501 if (ssh->sc_mac_ctx)
10502 ssh->scmac->free_context(ssh->sc_mac_ctx);
10503 if (ssh->cs_comp_ctx) {
10505 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
10507 zlib_compress_cleanup(ssh->cs_comp_ctx);
10509 if (ssh->sc_comp_ctx) {
10511 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
10513 zlib_decompress_cleanup(ssh->sc_comp_ctx);
10516 dh_cleanup(ssh->kex_ctx);
10517 sfree(ssh->savedhost);
10519 while (ssh->queuelen-- > 0)
10520 ssh_free_packet(ssh->queue[ssh->queuelen]);
10523 while (ssh->qhead) {
10524 struct queued_handler *qh = ssh->qhead;
10525 ssh->qhead = qh->next;
10528 ssh->qhead = ssh->qtail = NULL;
10530 if (ssh->channels) {
10531 while ((c = delpos234(ssh->channels, 0)) != NULL) {
10534 if (c->u.x11.xconn != NULL)
10535 x11_close(c->u.x11.xconn);
10537 case CHAN_SOCKDATA:
10538 case CHAN_SOCKDATA_DORMANT:
10539 if (c->u.pfd.pf != NULL)
10540 pfd_close(c->u.pfd.pf);
10543 if (ssh->version == 2) {
10544 struct outstanding_channel_request *ocr, *nocr;
10545 ocr = c->v.v2.chanreq_head;
10547 ocr->handler(c, NULL, ocr->ctx);
10552 bufchain_clear(&c->v.v2.outbuffer);
10556 freetree234(ssh->channels);
10557 ssh->channels = NULL;
10560 if (ssh->connshare)
10561 sharestate_free(ssh->connshare);
10563 if (ssh->rportfwds) {
10564 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
10566 freetree234(ssh->rportfwds);
10567 ssh->rportfwds = NULL;
10569 sfree(ssh->deferred_send_data);
10571 x11_free_display(ssh->x11disp);
10572 while ((auth = delpos234(ssh->x11authtree, 0)) != NULL)
10573 x11_free_fake_auth(auth);
10574 freetree234(ssh->x11authtree);
10575 sfree(ssh->do_ssh_init_state);
10576 sfree(ssh->do_ssh1_login_state);
10577 sfree(ssh->do_ssh2_transport_state);
10578 sfree(ssh->do_ssh2_authconn_state);
10581 sfree(ssh->fullhostname);
10582 sfree(ssh->hostkey_str);
10583 if (ssh->crcda_ctx) {
10584 crcda_free_context(ssh->crcda_ctx);
10585 ssh->crcda_ctx = NULL;
10588 ssh_do_close(ssh, TRUE);
10589 expire_timer_context(ssh);
10591 pinger_free(ssh->pinger);
10592 bufchain_clear(&ssh->queued_incoming_data);
10593 sfree(ssh->username);
10594 conf_free(ssh->conf);
10597 ssh_gss_cleanup(ssh->gsslibs);
10605 * Reconfigure the SSH backend.
10607 static void ssh_reconfig(void *handle, Conf *conf)
10609 Ssh ssh = (Ssh) handle;
10610 char *rekeying = NULL, rekey_mandatory = FALSE;
10611 unsigned long old_max_data_size;
10614 pinger_reconfig(ssh->pinger, ssh->conf, conf);
10616 ssh_setup_portfwd(ssh, conf);
10618 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
10619 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
10621 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
10622 unsigned long now = GETTICKCOUNT();
10624 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
10625 rekeying = "timeout shortened";
10627 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
10631 old_max_data_size = ssh->max_data_size;
10632 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10633 CONF_ssh_rekey_data));
10634 if (old_max_data_size != ssh->max_data_size &&
10635 ssh->max_data_size != 0) {
10636 if (ssh->outgoing_data_size > ssh->max_data_size ||
10637 ssh->incoming_data_size > ssh->max_data_size)
10638 rekeying = "data limit lowered";
10641 if (conf_get_int(ssh->conf, CONF_compression) !=
10642 conf_get_int(conf, CONF_compression)) {
10643 rekeying = "compression setting changed";
10644 rekey_mandatory = TRUE;
10647 for (i = 0; i < CIPHER_MAX; i++)
10648 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
10649 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
10650 rekeying = "cipher settings changed";
10651 rekey_mandatory = TRUE;
10653 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
10654 conf_get_int(conf, CONF_ssh2_des_cbc)) {
10655 rekeying = "cipher settings changed";
10656 rekey_mandatory = TRUE;
10659 conf_free(ssh->conf);
10660 ssh->conf = conf_copy(conf);
10661 ssh_cache_conf_values(ssh);
10663 if (!ssh->bare_connection && rekeying) {
10664 if (!ssh->kex_in_progress) {
10665 do_ssh2_transport(ssh, rekeying, -1, NULL);
10666 } else if (rekey_mandatory) {
10667 ssh->deferred_rekey_reason = rekeying;
10673 * Called to send data down the SSH connection.
10675 static int ssh_send(void *handle, char *buf, int len)
10677 Ssh ssh = (Ssh) handle;
10679 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10682 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
10684 return ssh_sendbuffer(ssh);
10688 * Called to query the current amount of buffered stdin data.
10690 static int ssh_sendbuffer(void *handle)
10692 Ssh ssh = (Ssh) handle;
10693 int override_value;
10695 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10699 * If the SSH socket itself has backed up, add the total backup
10700 * size on that to any individual buffer on the stdin channel.
10702 override_value = 0;
10703 if (ssh->throttled_all)
10704 override_value = ssh->overall_bufsize;
10706 if (ssh->version == 1) {
10707 return override_value;
10708 } else if (ssh->version == 2) {
10709 if (!ssh->mainchan)
10710 return override_value;
10712 return (override_value +
10713 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
10720 * Called to set the size of the window from SSH's POV.
10722 static void ssh_size(void *handle, int width, int height)
10724 Ssh ssh = (Ssh) handle;
10725 struct Packet *pktout;
10727 ssh->term_width = width;
10728 ssh->term_height = height;
10730 switch (ssh->state) {
10731 case SSH_STATE_BEFORE_SIZE:
10732 case SSH_STATE_PREPACKET:
10733 case SSH_STATE_CLOSED:
10734 break; /* do nothing */
10735 case SSH_STATE_INTERMED:
10736 ssh->size_needed = TRUE; /* buffer for later */
10738 case SSH_STATE_SESSION:
10739 if (!conf_get_int(ssh->conf, CONF_nopty)) {
10740 if (ssh->version == 1) {
10741 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
10742 PKT_INT, ssh->term_height,
10743 PKT_INT, ssh->term_width,
10744 PKT_INT, 0, PKT_INT, 0, PKT_END);
10745 } else if (ssh->mainchan) {
10746 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
10748 ssh2_pkt_adduint32(pktout, ssh->term_width);
10749 ssh2_pkt_adduint32(pktout, ssh->term_height);
10750 ssh2_pkt_adduint32(pktout, 0);
10751 ssh2_pkt_adduint32(pktout, 0);
10752 ssh2_pkt_send(ssh, pktout);
10760 * Return a list of the special codes that make sense in this
10763 static const struct telnet_special *ssh_get_specials(void *handle)
10765 static const struct telnet_special ssh1_ignore_special[] = {
10766 {"IGNORE message", TS_NOP}
10768 static const struct telnet_special ssh2_ignore_special[] = {
10769 {"IGNORE message", TS_NOP},
10771 static const struct telnet_special ssh2_rekey_special[] = {
10772 {"Repeat key exchange", TS_REKEY},
10774 static const struct telnet_special ssh2_session_specials[] = {
10777 /* These are the signal names defined by RFC 4254.
10778 * They include all the ISO C signals, but are a subset of the POSIX
10779 * required signals. */
10780 {"SIGINT (Interrupt)", TS_SIGINT},
10781 {"SIGTERM (Terminate)", TS_SIGTERM},
10782 {"SIGKILL (Kill)", TS_SIGKILL},
10783 {"SIGQUIT (Quit)", TS_SIGQUIT},
10784 {"SIGHUP (Hangup)", TS_SIGHUP},
10785 {"More signals", TS_SUBMENU},
10786 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
10787 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
10788 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
10789 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
10790 {NULL, TS_EXITMENU}
10792 static const struct telnet_special specials_end[] = {
10793 {NULL, TS_EXITMENU}
10795 /* XXX review this length for any changes: */
10796 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
10797 lenof(ssh2_rekey_special) +
10798 lenof(ssh2_session_specials) +
10799 lenof(specials_end)];
10800 Ssh ssh = (Ssh) handle;
10802 #define ADD_SPECIALS(name) \
10804 assert((i + lenof(name)) <= lenof(ssh_specials)); \
10805 memcpy(&ssh_specials[i], name, sizeof name); \
10806 i += lenof(name); \
10809 if (ssh->version == 1) {
10810 /* Don't bother offering IGNORE if we've decided the remote
10811 * won't cope with it, since we wouldn't bother sending it if
10813 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
10814 ADD_SPECIALS(ssh1_ignore_special);
10815 } else if (ssh->version == 2) {
10816 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
10817 ADD_SPECIALS(ssh2_ignore_special);
10818 if (!(ssh->remote_bugs & BUG_SSH2_REKEY) && !ssh->bare_connection)
10819 ADD_SPECIALS(ssh2_rekey_special);
10821 ADD_SPECIALS(ssh2_session_specials);
10822 } /* else we're not ready yet */
10825 ADD_SPECIALS(specials_end);
10826 return ssh_specials;
10830 #undef ADD_SPECIALS
10834 * Send special codes. TS_EOF is useful for `plink', so you
10835 * can send an EOF and collect resulting output (e.g. `plink
10838 static void ssh_special(void *handle, Telnet_Special code)
10840 Ssh ssh = (Ssh) handle;
10841 struct Packet *pktout;
10843 if (code == TS_EOF) {
10844 if (ssh->state != SSH_STATE_SESSION) {
10846 * Buffer the EOF in case we are pre-SESSION, so we can
10847 * send it as soon as we reach SESSION.
10849 if (code == TS_EOF)
10850 ssh->eof_needed = TRUE;
10853 if (ssh->version == 1) {
10854 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
10855 } else if (ssh->mainchan) {
10856 sshfwd_write_eof(ssh->mainchan);
10857 ssh->send_ok = 0; /* now stop trying to read from stdin */
10859 logevent("Sent EOF message");
10860 } else if (code == TS_PING || code == TS_NOP) {
10861 if (ssh->state == SSH_STATE_CLOSED
10862 || ssh->state == SSH_STATE_PREPACKET) return;
10863 if (ssh->version == 1) {
10864 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
10865 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
10867 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
10868 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
10869 ssh2_pkt_addstring_start(pktout);
10870 ssh2_pkt_send_noqueue(ssh, pktout);
10873 } else if (code == TS_REKEY) {
10874 if (!ssh->kex_in_progress && !ssh->bare_connection &&
10875 ssh->version == 2) {
10876 do_ssh2_transport(ssh, "at user request", -1, NULL);
10878 } else if (code == TS_BRK) {
10879 if (ssh->state == SSH_STATE_CLOSED
10880 || ssh->state == SSH_STATE_PREPACKET) return;
10881 if (ssh->version == 1) {
10882 logevent("Unable to send BREAK signal in SSH-1");
10883 } else if (ssh->mainchan) {
10884 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
10885 ssh2_pkt_adduint32(pktout, 0); /* default break length */
10886 ssh2_pkt_send(ssh, pktout);
10889 /* Is is a POSIX signal? */
10890 char *signame = NULL;
10891 if (code == TS_SIGABRT) signame = "ABRT";
10892 if (code == TS_SIGALRM) signame = "ALRM";
10893 if (code == TS_SIGFPE) signame = "FPE";
10894 if (code == TS_SIGHUP) signame = "HUP";
10895 if (code == TS_SIGILL) signame = "ILL";
10896 if (code == TS_SIGINT) signame = "INT";
10897 if (code == TS_SIGKILL) signame = "KILL";
10898 if (code == TS_SIGPIPE) signame = "PIPE";
10899 if (code == TS_SIGQUIT) signame = "QUIT";
10900 if (code == TS_SIGSEGV) signame = "SEGV";
10901 if (code == TS_SIGTERM) signame = "TERM";
10902 if (code == TS_SIGUSR1) signame = "USR1";
10903 if (code == TS_SIGUSR2) signame = "USR2";
10904 /* The SSH-2 protocol does in principle support arbitrary named
10905 * signals, including signame@domain, but we don't support those. */
10907 /* It's a signal. */
10908 if (ssh->version == 2 && ssh->mainchan) {
10909 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
10910 ssh2_pkt_addstring(pktout, signame);
10911 ssh2_pkt_send(ssh, pktout);
10912 logeventf(ssh, "Sent signal SIG%s", signame);
10915 /* Never heard of it. Do nothing */
10920 void *new_sock_channel(void *handle, struct PortForwarding *pf)
10922 Ssh ssh = (Ssh) handle;
10923 struct ssh_channel *c;
10924 c = snew(struct ssh_channel);
10927 ssh2_channel_init(c);
10928 c->halfopen = TRUE;
10929 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
10931 add234(ssh->channels, c);
10935 unsigned ssh_alloc_sharing_channel(Ssh ssh, void *sharing_ctx)
10937 struct ssh_channel *c;
10938 c = snew(struct ssh_channel);
10941 ssh2_channel_init(c);
10942 c->type = CHAN_SHARING;
10943 c->u.sharing.ctx = sharing_ctx;
10944 add234(ssh->channels, c);
10948 void ssh_delete_sharing_channel(Ssh ssh, unsigned localid)
10950 struct ssh_channel *c;
10952 c = find234(ssh->channels, &localid, ssh_channelfind);
10954 ssh_channel_destroy(c);
10957 void ssh_send_packet_from_downstream(Ssh ssh, unsigned id, int type,
10958 const void *data, int datalen,
10959 const char *additional_log_text)
10961 struct Packet *pkt;
10963 pkt = ssh2_pkt_init(type);
10964 pkt->downstream_id = id;
10965 pkt->additional_log_text = additional_log_text;
10966 ssh2_pkt_adddata(pkt, data, datalen);
10967 ssh2_pkt_send(ssh, pkt);
10971 * This is called when stdout/stderr (the entity to which
10972 * from_backend sends data) manages to clear some backlog.
10974 static void ssh_unthrottle(void *handle, int bufsize)
10976 Ssh ssh = (Ssh) handle;
10979 if (ssh->version == 1) {
10980 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
10981 ssh->v1_stdout_throttling = 0;
10982 ssh_throttle_conn(ssh, -1);
10985 if (ssh->mainchan) {
10986 ssh2_set_window(ssh->mainchan,
10987 bufsize < ssh->mainchan->v.v2.locmaxwin ?
10988 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
10989 if (ssh_is_simple(ssh))
10992 buflimit = ssh->mainchan->v.v2.locmaxwin;
10993 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
10994 ssh->mainchan->throttling_conn = 0;
10995 ssh_throttle_conn(ssh, -1);
11001 * Now process any SSH connection data that was stashed in our
11002 * queue while we were frozen.
11004 ssh_process_queued_incoming_data(ssh);
11007 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
11009 struct ssh_channel *c = (struct ssh_channel *)channel;
11011 struct Packet *pktout;
11013 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
11015 if (ssh->version == 1) {
11016 send_packet(ssh, SSH1_MSG_PORT_OPEN,
11017 PKT_INT, c->localid,
11020 /* PKT_STR, <org:orgport>, */
11023 pktout = ssh2_chanopen_init(c, "direct-tcpip");
11024 ssh2_pkt_addstring(pktout, hostname);
11025 ssh2_pkt_adduint32(pktout, port);
11027 * We make up values for the originator data; partly it's
11028 * too much hassle to keep track, and partly I'm not
11029 * convinced the server should be told details like that
11030 * about my local network configuration.
11031 * The "originator IP address" is syntactically a numeric
11032 * IP address, and some servers (e.g., Tectia) get upset
11033 * if it doesn't match this syntax.
11035 ssh2_pkt_addstring(pktout, "0.0.0.0");
11036 ssh2_pkt_adduint32(pktout, 0);
11037 ssh2_pkt_send(ssh, pktout);
11041 static int ssh_connected(void *handle)
11043 Ssh ssh = (Ssh) handle;
11044 return ssh->s != NULL;
11047 static int ssh_sendok(void *handle)
11049 Ssh ssh = (Ssh) handle;
11050 return ssh->send_ok;
11053 static int ssh_ldisc(void *handle, int option)
11055 Ssh ssh = (Ssh) handle;
11056 if (option == LD_ECHO)
11057 return ssh->echoing;
11058 if (option == LD_EDIT)
11059 return ssh->editing;
11063 static void ssh_provide_ldisc(void *handle, void *ldisc)
11065 Ssh ssh = (Ssh) handle;
11066 ssh->ldisc = ldisc;
11069 static void ssh_provide_logctx(void *handle, void *logctx)
11071 Ssh ssh = (Ssh) handle;
11072 ssh->logctx = logctx;
11075 static int ssh_return_exitcode(void *handle)
11077 Ssh ssh = (Ssh) handle;
11078 if (ssh->s != NULL)
11081 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
11085 * cfg_info for SSH is the currently running version of the
11086 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
11088 static int ssh_cfg_info(void *handle)
11090 Ssh ssh = (Ssh) handle;
11091 return ssh->version;
11095 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
11096 * that fails. This variable is the means by which scp.c can reach
11097 * into the SSH code and find out which one it got.
11099 extern int ssh_fallback_cmd(void *handle)
11101 Ssh ssh = (Ssh) handle;
11102 return ssh->fallback_cmd;
11105 Backend ssh_backend = {
11115 ssh_return_exitcode,
11119 ssh_provide_logctx,