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++;
1714 st->pktin->length = st->packetlen - st->pad;
1715 assert(st->pktin->length >= 0);
1718 * Decompress packet payload.
1721 unsigned char *newpayload;
1724 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1725 st->pktin->data + 5, st->pktin->length - 5,
1726 &newpayload, &newlen)) {
1727 if (st->pktin->maxlen < newlen + 5) {
1728 st->pktin->maxlen = newlen + 5;
1729 st->pktin->data = sresize(st->pktin->data,
1730 st->pktin->maxlen + APIEXTRA,
1733 st->pktin->length = 5 + newlen;
1734 memcpy(st->pktin->data + 5, newpayload, newlen);
1740 * pktin->body and pktin->length should identify the semantic
1741 * content of the packet, excluding the initial type byte.
1743 st->pktin->type = st->pktin->data[5];
1744 st->pktin->body = st->pktin->data + 6;
1745 st->pktin->length -= 6;
1746 assert(st->pktin->length >= 0); /* one last double-check */
1749 ssh2_log_incoming_packet(ssh, st->pktin);
1751 st->pktin->savedpos = 0;
1753 crFinish(st->pktin);
1756 static struct Packet *ssh2_bare_connection_rdpkt(Ssh ssh, unsigned char **data,
1759 struct rdpkt2_bare_state_tag *st = &ssh->rdpkt2_bare_state;
1761 crBegin(ssh->ssh2_bare_rdpkt_crstate);
1764 * Read the packet length field.
1766 for (st->i = 0; st->i < 4; st->i++) {
1767 while ((*datalen) == 0)
1769 st->length[st->i] = *(*data)++;
1773 st->packetlen = toint(GET_32BIT_MSB_FIRST(st->length));
1774 if (st->packetlen <= 0 || st->packetlen >= OUR_V2_PACKETLIMIT) {
1775 bombout(("Invalid packet length received"));
1779 st->pktin = ssh_new_packet();
1780 st->pktin->data = snewn(st->packetlen, unsigned char);
1782 st->pktin->encrypted_len = st->packetlen;
1784 st->pktin->sequence = st->incoming_sequence++;
1787 * Read the remainder of the packet.
1789 for (st->i = 0; st->i < st->packetlen; st->i++) {
1790 while ((*datalen) == 0)
1792 st->pktin->data[st->i] = *(*data)++;
1797 * pktin->body and pktin->length should identify the semantic
1798 * content of the packet, excluding the initial type byte.
1800 st->pktin->type = st->pktin->data[0];
1801 st->pktin->body = st->pktin->data + 1;
1802 st->pktin->length = st->packetlen - 1;
1805 * Log incoming packet, possibly omitting sensitive fields.
1808 ssh2_log_incoming_packet(ssh, st->pktin);
1810 st->pktin->savedpos = 0;
1812 crFinish(st->pktin);
1815 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1817 int pad, biglen, i, pktoffs;
1821 * XXX various versions of SC (including 8.8.4) screw up the
1822 * register allocation in this function and use the same register
1823 * (D6) for len and as a temporary, with predictable results. The
1824 * following sledgehammer prevents this.
1831 ssh1_log_outgoing_packet(ssh, pkt);
1833 if (ssh->v1_compressing) {
1834 unsigned char *compblk;
1836 zlib_compress_block(ssh->cs_comp_ctx,
1837 pkt->data + 12, pkt->length - 12,
1838 &compblk, &complen);
1839 ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */
1840 memcpy(pkt->data + 12, compblk, complen);
1842 pkt->length = complen + 12;
1845 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1847 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
1848 pad = 8 - (len % 8);
1850 biglen = len + pad; /* len(padding+type+data+CRC) */
1852 for (i = pktoffs; i < 4+8; i++)
1853 pkt->data[i] = random_byte();
1854 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1855 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1856 PUT_32BIT(pkt->data + pktoffs, len);
1859 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1860 pkt->data + pktoffs + 4, biglen);
1862 if (offset_p) *offset_p = pktoffs;
1863 return biglen + 4; /* len(length+padding+type+data+CRC) */
1866 static int s_write(Ssh ssh, void *data, int len)
1869 log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len,
1870 0, NULL, NULL, 0, NULL);
1873 return sk_write(ssh->s, (char *)data, len);
1876 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1878 int len, backlog, offset;
1879 len = s_wrpkt_prepare(ssh, pkt, &offset);
1880 backlog = s_write(ssh, pkt->data + offset, len);
1881 if (backlog > SSH_MAX_BACKLOG)
1882 ssh_throttle_all(ssh, 1, backlog);
1883 ssh_free_packet(pkt);
1886 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1889 len = s_wrpkt_prepare(ssh, pkt, &offset);
1890 if (ssh->deferred_len + len > ssh->deferred_size) {
1891 ssh->deferred_size = ssh->deferred_len + len + 128;
1892 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1896 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1897 pkt->data + offset, len);
1898 ssh->deferred_len += len;
1899 ssh_free_packet(pkt);
1903 * Construct a SSH-1 packet with the specified contents.
1904 * (This all-at-once interface used to be the only one, but now SSH-1
1905 * packets can also be constructed incrementally.)
1907 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
1913 pkt = ssh1_pkt_init(pkttype);
1915 while ((argtype = va_arg(ap, int)) != PKT_END) {
1916 unsigned char *argp, argchar;
1918 unsigned long argint;
1921 /* Actual fields in the packet */
1923 argint = va_arg(ap, int);
1924 ssh_pkt_adduint32(pkt, argint);
1927 argchar = (unsigned char) va_arg(ap, int);
1928 ssh_pkt_addbyte(pkt, argchar);
1931 argp = va_arg(ap, unsigned char *);
1932 arglen = va_arg(ap, int);
1933 ssh_pkt_adddata(pkt, argp, arglen);
1936 sargp = va_arg(ap, char *);
1937 ssh_pkt_addstring(pkt, sargp);
1940 bn = va_arg(ap, Bignum);
1941 ssh1_pkt_addmp(pkt, bn);
1949 static void send_packet(Ssh ssh, int pkttype, ...)
1953 va_start(ap, pkttype);
1954 pkt = construct_packet(ssh, pkttype, ap);
1959 static void defer_packet(Ssh ssh, int pkttype, ...)
1963 va_start(ap, pkttype);
1964 pkt = construct_packet(ssh, pkttype, ap);
1966 s_wrpkt_defer(ssh, pkt);
1969 static int ssh_versioncmp(char *a, char *b)
1972 unsigned long av, bv;
1974 av = strtoul(a, &ae, 10);
1975 bv = strtoul(b, &be, 10);
1977 return (av < bv ? -1 : +1);
1982 av = strtoul(ae, &ae, 10);
1983 bv = strtoul(be, &be, 10);
1985 return (av < bv ? -1 : +1);
1990 * Utility routines for putting an SSH-protocol `string' and
1991 * `uint32' into a hash state.
1993 static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
1995 unsigned char lenblk[4];
1996 PUT_32BIT(lenblk, len);
1997 h->bytes(s, lenblk, 4);
1998 h->bytes(s, str, len);
2001 static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
2003 unsigned char intblk[4];
2004 PUT_32BIT(intblk, i);
2005 h->bytes(s, intblk, 4);
2009 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
2011 static void ssh_pkt_ensure(struct Packet *pkt, int length)
2013 if (pkt->maxlen < length) {
2014 unsigned char *body = pkt->body;
2015 int offset = body ? body - pkt->data : 0;
2016 pkt->maxlen = length + 256;
2017 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
2018 if (body) pkt->body = pkt->data + offset;
2021 static void ssh_pkt_adddata(struct Packet *pkt, const void *data, int len)
2024 ssh_pkt_ensure(pkt, pkt->length);
2025 memcpy(pkt->data + pkt->length - len, data, len);
2027 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
2029 ssh_pkt_adddata(pkt, &byte, 1);
2031 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
2033 ssh_pkt_adddata(pkt, &value, 1);
2035 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
2038 PUT_32BIT(x, value);
2039 ssh_pkt_adddata(pkt, x, 4);
2041 static void ssh_pkt_addstring_start(struct Packet *pkt)
2043 ssh_pkt_adduint32(pkt, 0);
2044 pkt->savedpos = pkt->length;
2046 static void ssh_pkt_addstring_str(struct Packet *pkt, const char *data)
2048 ssh_pkt_adddata(pkt, data, strlen(data));
2049 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
2051 static void ssh_pkt_addstring_data(struct Packet *pkt, const char *data,
2054 ssh_pkt_adddata(pkt, data, len);
2055 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
2057 static void ssh_pkt_addstring(struct Packet *pkt, const char *data)
2059 ssh_pkt_addstring_start(pkt);
2060 ssh_pkt_addstring_str(pkt, data);
2062 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
2064 int len = ssh1_bignum_length(b);
2065 unsigned char *data = snewn(len, unsigned char);
2066 (void) ssh1_write_bignum(data, b);
2067 ssh_pkt_adddata(pkt, data, len);
2070 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
2073 int i, n = (bignum_bitcount(b) + 7) / 8;
2074 p = snewn(n + 1, unsigned char);
2076 for (i = 1; i <= n; i++)
2077 p[i] = bignum_byte(b, n - i);
2079 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
2081 memmove(p, p + i, n + 1 - i);
2085 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
2089 p = ssh2_mpint_fmt(b, &len);
2090 ssh_pkt_addstring_start(pkt);
2091 ssh_pkt_addstring_data(pkt, (char *)p, len);
2095 static struct Packet *ssh1_pkt_init(int pkt_type)
2097 struct Packet *pkt = ssh_new_packet();
2098 pkt->length = 4 + 8; /* space for length + max padding */
2099 ssh_pkt_addbyte(pkt, pkt_type);
2100 pkt->body = pkt->data + pkt->length;
2101 pkt->type = pkt_type;
2102 pkt->downstream_id = 0;
2103 pkt->additional_log_text = NULL;
2107 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
2108 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
2109 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
2110 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
2111 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
2112 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
2113 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
2114 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
2115 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
2117 static struct Packet *ssh2_pkt_init(int pkt_type)
2119 struct Packet *pkt = ssh_new_packet();
2120 pkt->length = 5; /* space for packet length + padding length */
2122 pkt->type = pkt_type;
2123 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
2124 pkt->body = pkt->data + pkt->length; /* after packet type */
2125 pkt->downstream_id = 0;
2126 pkt->additional_log_text = NULL;
2131 * Construct an SSH-2 final-form packet: compress it, encrypt it,
2132 * put the MAC on it. Final packet, ready to be sent, is stored in
2133 * pkt->data. Total length is returned.
2135 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
2137 int cipherblk, maclen, padding, i;
2140 ssh2_log_outgoing_packet(ssh, pkt);
2142 if (ssh->bare_connection) {
2144 * Trivial packet construction for the bare connection
2147 PUT_32BIT(pkt->data + 1, pkt->length - 5);
2148 pkt->body = pkt->data + 1;
2149 ssh->v2_outgoing_sequence++; /* only for diagnostics, really */
2150 return pkt->length - 1;
2154 * Compress packet payload.
2157 unsigned char *newpayload;
2160 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
2162 &newpayload, &newlen)) {
2164 ssh2_pkt_adddata(pkt, newpayload, newlen);
2170 * Add padding. At least four bytes, and must also bring total
2171 * length (minus MAC) up to a multiple of the block size.
2172 * If pkt->forcepad is set, make sure the packet is at least that size
2175 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
2176 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
2178 if (pkt->length + padding < pkt->forcepad)
2179 padding = pkt->forcepad - pkt->length;
2181 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
2182 assert(padding <= 255);
2183 maclen = ssh->csmac ? ssh->csmac->len : 0;
2184 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
2185 pkt->data[4] = padding;
2186 for (i = 0; i < padding; i++)
2187 pkt->data[pkt->length + i] = random_byte();
2188 PUT_32BIT(pkt->data, pkt->length + padding - 4);
2190 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
2191 pkt->length + padding,
2192 ssh->v2_outgoing_sequence);
2193 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
2196 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
2197 pkt->data, pkt->length + padding);
2199 pkt->encrypted_len = pkt->length + padding;
2201 /* Ready-to-send packet starts at pkt->data. We return length. */
2202 pkt->body = pkt->data;
2203 return pkt->length + padding + maclen;
2207 * Routines called from the main SSH code to send packets. There
2208 * are quite a few of these, because we have two separate
2209 * mechanisms for delaying the sending of packets:
2211 * - In order to send an IGNORE message and a password message in
2212 * a single fixed-length blob, we require the ability to
2213 * concatenate the encrypted forms of those two packets _into_ a
2214 * single blob and then pass it to our <network.h> transport
2215 * layer in one go. Hence, there's a deferment mechanism which
2216 * works after packet encryption.
2218 * - In order to avoid sending any connection-layer messages
2219 * during repeat key exchange, we have to queue up any such
2220 * outgoing messages _before_ they are encrypted (and in
2221 * particular before they're allocated sequence numbers), and
2222 * then send them once we've finished.
2224 * I call these mechanisms `defer' and `queue' respectively, so as
2225 * to distinguish them reasonably easily.
2227 * The functions send_noqueue() and defer_noqueue() free the packet
2228 * structure they are passed. Every outgoing packet goes through
2229 * precisely one of these functions in its life; packets passed to
2230 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
2231 * these or get queued, and then when the queue is later emptied
2232 * the packets are all passed to defer_noqueue().
2234 * When using a CBC-mode cipher, it's necessary to ensure that an
2235 * attacker can't provide data to be encrypted using an IV that they
2236 * know. We ensure this by prefixing each packet that might contain
2237 * user data with an SSH_MSG_IGNORE. This is done using the deferral
2238 * mechanism, so in this case send_noqueue() ends up redirecting to
2239 * defer_noqueue(). If you don't like this inefficiency, don't use
2243 static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
2244 static void ssh_pkt_defersend(Ssh);
2247 * Send an SSH-2 packet immediately, without queuing or deferring.
2249 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
2253 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
2254 /* We need to send two packets, so use the deferral mechanism. */
2255 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2256 ssh_pkt_defersend(ssh);
2259 len = ssh2_pkt_construct(ssh, pkt);
2260 backlog = s_write(ssh, pkt->body, len);
2261 if (backlog > SSH_MAX_BACKLOG)
2262 ssh_throttle_all(ssh, 1, backlog);
2264 ssh->outgoing_data_size += pkt->encrypted_len;
2265 if (!ssh->kex_in_progress &&
2266 !ssh->bare_connection &&
2267 ssh->max_data_size != 0 &&
2268 ssh->outgoing_data_size > ssh->max_data_size)
2269 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2271 ssh_free_packet(pkt);
2275 * Defer an SSH-2 packet.
2277 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
2280 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
2281 ssh->deferred_len == 0 && !noignore &&
2282 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2284 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2285 * get encrypted with a known IV.
2287 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2288 ssh2_pkt_addstring_start(ipkt);
2289 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
2291 len = ssh2_pkt_construct(ssh, pkt);
2292 if (ssh->deferred_len + len > ssh->deferred_size) {
2293 ssh->deferred_size = ssh->deferred_len + len + 128;
2294 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2298 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->body, len);
2299 ssh->deferred_len += len;
2300 ssh->deferred_data_size += pkt->encrypted_len;
2301 ssh_free_packet(pkt);
2305 * Queue an SSH-2 packet.
2307 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
2309 assert(ssh->queueing);
2311 if (ssh->queuelen >= ssh->queuesize) {
2312 ssh->queuesize = ssh->queuelen + 32;
2313 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
2316 ssh->queue[ssh->queuelen++] = pkt;
2320 * Either queue or send a packet, depending on whether queueing is
2323 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
2326 ssh2_pkt_queue(ssh, pkt);
2328 ssh2_pkt_send_noqueue(ssh, pkt);
2332 * Either queue or defer a packet, depending on whether queueing is
2335 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
2338 ssh2_pkt_queue(ssh, pkt);
2340 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2344 * Send the whole deferred data block constructed by
2345 * ssh2_pkt_defer() or SSH-1's defer_packet().
2347 * The expected use of the defer mechanism is that you call
2348 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2349 * not currently queueing, this simply sets up deferred_send_data
2350 * and then sends it. If we _are_ currently queueing, the calls to
2351 * ssh2_pkt_defer() put the deferred packets on to the queue
2352 * instead, and therefore ssh_pkt_defersend() has no deferred data
2353 * to send. Hence, there's no need to make it conditional on
2356 static void ssh_pkt_defersend(Ssh ssh)
2359 backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
2360 ssh->deferred_len = ssh->deferred_size = 0;
2361 sfree(ssh->deferred_send_data);
2362 ssh->deferred_send_data = NULL;
2363 if (backlog > SSH_MAX_BACKLOG)
2364 ssh_throttle_all(ssh, 1, backlog);
2366 ssh->outgoing_data_size += ssh->deferred_data_size;
2367 if (!ssh->kex_in_progress &&
2368 !ssh->bare_connection &&
2369 ssh->max_data_size != 0 &&
2370 ssh->outgoing_data_size > ssh->max_data_size)
2371 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2372 ssh->deferred_data_size = 0;
2376 * Send a packet whose length needs to be disguised (typically
2377 * passwords or keyboard-interactive responses).
2379 static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
2385 * The simplest way to do this is to adjust the
2386 * variable-length padding field in the outgoing packet.
2388 * Currently compiled out, because some Cisco SSH servers
2389 * don't like excessively padded packets (bah, why's it
2392 pkt->forcepad = padsize;
2393 ssh2_pkt_send(ssh, pkt);
2398 * If we can't do that, however, an alternative approach is
2399 * to use the pkt_defer mechanism to bundle the packet
2400 * tightly together with an SSH_MSG_IGNORE such that their
2401 * combined length is a constant. So first we construct the
2402 * final form of this packet and defer its sending.
2404 ssh2_pkt_defer(ssh, pkt);
2407 * Now construct an SSH_MSG_IGNORE which includes a string
2408 * that's an exact multiple of the cipher block size. (If
2409 * the cipher is NULL so that the block size is
2410 * unavailable, we don't do this trick at all, because we
2411 * gain nothing by it.)
2413 if (ssh->cscipher &&
2414 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2417 stringlen = (256 - ssh->deferred_len);
2418 stringlen += ssh->cscipher->blksize - 1;
2419 stringlen -= (stringlen % ssh->cscipher->blksize);
2422 * Temporarily disable actual compression, so we
2423 * can guarantee to get this string exactly the
2424 * length we want it. The compression-disabling
2425 * routine should return an integer indicating how
2426 * many bytes we should adjust our string length
2430 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
2432 pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2433 ssh2_pkt_addstring_start(pkt);
2434 for (i = 0; i < stringlen; i++) {
2435 char c = (char) random_byte();
2436 ssh2_pkt_addstring_data(pkt, &c, 1);
2438 ssh2_pkt_defer(ssh, pkt);
2440 ssh_pkt_defersend(ssh);
2445 * Send all queued SSH-2 packets. We send them by means of
2446 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2447 * packets that needed to be lumped together.
2449 static void ssh2_pkt_queuesend(Ssh ssh)
2453 assert(!ssh->queueing);
2455 for (i = 0; i < ssh->queuelen; i++)
2456 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
2459 ssh_pkt_defersend(ssh);
2463 void bndebug(char *string, Bignum b)
2467 p = ssh2_mpint_fmt(b, &len);
2468 debug(("%s", string));
2469 for (i = 0; i < len; i++)
2470 debug((" %02x", p[i]));
2476 static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
2480 p = ssh2_mpint_fmt(b, &len);
2481 hash_string(h, s, p, len);
2486 * Packet decode functions for both SSH-1 and SSH-2.
2488 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
2490 unsigned long value;
2491 if (pkt->length - pkt->savedpos < 4)
2492 return 0; /* arrgh, no way to decline (FIXME?) */
2493 value = GET_32BIT(pkt->body + pkt->savedpos);
2497 static int ssh2_pkt_getbool(struct Packet *pkt)
2499 unsigned long value;
2500 if (pkt->length - pkt->savedpos < 1)
2501 return 0; /* arrgh, no way to decline (FIXME?) */
2502 value = pkt->body[pkt->savedpos] != 0;
2506 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
2511 if (pkt->length - pkt->savedpos < 4)
2513 len = toint(GET_32BIT(pkt->body + pkt->savedpos));
2518 if (pkt->length - pkt->savedpos < *length)
2520 *p = (char *)(pkt->body + pkt->savedpos);
2521 pkt->savedpos += *length;
2523 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
2525 if (pkt->length - pkt->savedpos < length)
2527 pkt->savedpos += length;
2528 return pkt->body + (pkt->savedpos - length);
2530 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2531 unsigned char **keystr)
2535 j = makekey(pkt->body + pkt->savedpos,
2536 pkt->length - pkt->savedpos,
2543 assert(pkt->savedpos < pkt->length);
2547 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2552 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2553 pkt->length - pkt->savedpos, &b);
2561 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2567 ssh_pkt_getstring(pkt, &p, &length);
2572 b = bignum_from_bytes((unsigned char *)p, length);
2577 * Helper function to add an SSH-2 signature blob to a packet.
2578 * Expects to be shown the public key blob as well as the signature
2579 * blob. Normally works just like ssh2_pkt_addstring, but will
2580 * fiddle with the signature packet if necessary for
2581 * BUG_SSH2_RSA_PADDING.
2583 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2584 void *pkblob_v, int pkblob_len,
2585 void *sigblob_v, int sigblob_len)
2587 unsigned char *pkblob = (unsigned char *)pkblob_v;
2588 unsigned char *sigblob = (unsigned char *)sigblob_v;
2590 /* dmemdump(pkblob, pkblob_len); */
2591 /* dmemdump(sigblob, sigblob_len); */
2594 * See if this is in fact an ssh-rsa signature and a buggy
2595 * server; otherwise we can just do this the easy way.
2597 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) && pkblob_len > 4+7+4 &&
2598 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2599 int pos, len, siglen;
2602 * Find the byte length of the modulus.
2605 pos = 4+7; /* skip over "ssh-rsa" */
2606 len = toint(GET_32BIT(pkblob+pos)); /* get length of exponent */
2607 if (len < 0 || len > pkblob_len - pos - 4)
2609 pos += 4 + len; /* skip over exponent */
2610 if (pkblob_len - pos < 4)
2612 len = toint(GET_32BIT(pkblob+pos)); /* find length of modulus */
2613 if (len < 0 || len > pkblob_len - pos - 4)
2615 pos += 4; /* find modulus itself */
2616 while (len > 0 && pkblob[pos] == 0)
2618 /* debug(("modulus length is %d\n", len)); */
2621 * Now find the signature integer.
2623 pos = 4+7; /* skip over "ssh-rsa" */
2624 if (sigblob_len < pos+4)
2626 siglen = toint(GET_32BIT(sigblob+pos));
2627 if (siglen != sigblob_len - pos - 4)
2629 /* debug(("signature length is %d\n", siglen)); */
2631 if (len != siglen) {
2632 unsigned char newlen[4];
2633 ssh2_pkt_addstring_start(pkt);
2634 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2635 /* dmemdump(sigblob, pos); */
2636 pos += 4; /* point to start of actual sig */
2637 PUT_32BIT(newlen, len);
2638 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2639 /* dmemdump(newlen, 4); */
2641 while (len-- > siglen) {
2642 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2643 /* dmemdump(newlen, 1); */
2645 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2646 /* dmemdump(sigblob+pos, siglen); */
2650 /* Otherwise fall through and do it the easy way. We also come
2651 * here as a fallback if we discover above that the key blob
2652 * is misformatted in some way. */
2656 ssh2_pkt_addstring_start(pkt);
2657 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2661 * Examine the remote side's version string and compare it against
2662 * a list of known buggy implementations.
2664 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2666 char *imp; /* pointer to implementation part */
2668 imp += strcspn(imp, "-");
2670 imp += strcspn(imp, "-");
2673 ssh->remote_bugs = 0;
2676 * General notes on server version strings:
2677 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2678 * here -- in particular, we've heard of one that's perfectly happy
2679 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2680 * so we can't distinguish them.
2682 if (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == FORCE_ON ||
2683 (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == AUTO &&
2684 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2685 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2686 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2687 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2689 * These versions don't support SSH1_MSG_IGNORE, so we have
2690 * to use a different defence against password length
2693 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2694 logevent("We believe remote version has SSH-1 ignore bug");
2697 if (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == FORCE_ON ||
2698 (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == AUTO &&
2699 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2701 * These versions need a plain password sent; they can't
2702 * handle having a null and a random length of data after
2705 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2706 logevent("We believe remote version needs a plain SSH-1 password");
2709 if (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == FORCE_ON ||
2710 (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == AUTO &&
2711 (!strcmp(imp, "Cisco-1.25")))) {
2713 * These versions apparently have no clue whatever about
2714 * RSA authentication and will panic and die if they see
2715 * an AUTH_RSA message.
2717 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2718 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2721 if (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == FORCE_ON ||
2722 (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == AUTO &&
2723 !wc_match("* VShell", imp) &&
2724 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2725 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2726 wc_match("2.1 *", imp)))) {
2728 * These versions have the HMAC bug.
2730 ssh->remote_bugs |= BUG_SSH2_HMAC;
2731 logevent("We believe remote version has SSH-2 HMAC bug");
2734 if (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == FORCE_ON ||
2735 (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == AUTO &&
2736 !wc_match("* VShell", imp) &&
2737 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2739 * These versions have the key-derivation bug (failing to
2740 * include the literal shared secret in the hashes that
2741 * generate the keys).
2743 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2744 logevent("We believe remote version has SSH-2 key-derivation bug");
2747 if (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == FORCE_ON ||
2748 (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == AUTO &&
2749 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2750 wc_match("OpenSSH_3.[0-2]*", imp)))) {
2752 * These versions have the SSH-2 RSA padding bug.
2754 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2755 logevent("We believe remote version has SSH-2 RSA padding bug");
2758 if (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == FORCE_ON ||
2759 (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == AUTO &&
2760 wc_match("OpenSSH_2.[0-2]*", imp))) {
2762 * These versions have the SSH-2 session-ID bug in
2763 * public-key authentication.
2765 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2766 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2769 if (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == FORCE_ON ||
2770 (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == AUTO &&
2771 (wc_match("DigiSSH_2.0", imp) ||
2772 wc_match("OpenSSH_2.[0-4]*", imp) ||
2773 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2774 wc_match("Sun_SSH_1.0", imp) ||
2775 wc_match("Sun_SSH_1.0.1", imp) ||
2776 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2777 wc_match("WeOnlyDo-*", imp)))) {
2779 * These versions have the SSH-2 rekey bug.
2781 ssh->remote_bugs |= BUG_SSH2_REKEY;
2782 logevent("We believe remote version has SSH-2 rekey bug");
2785 if (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == FORCE_ON ||
2786 (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == AUTO &&
2787 (wc_match("1.36_sshlib GlobalSCAPE", imp) ||
2788 wc_match("1.36 sshlib: GlobalScape", imp)))) {
2790 * This version ignores our makpkt and needs to be throttled.
2792 ssh->remote_bugs |= BUG_SSH2_MAXPKT;
2793 logevent("We believe remote version ignores SSH-2 maximum packet size");
2796 if (conf_get_int(ssh->conf, CONF_sshbug_ignore2) == FORCE_ON) {
2798 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2799 * none detected automatically.
2801 ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE;
2802 logevent("We believe remote version has SSH-2 ignore bug");
2805 if (conf_get_int(ssh->conf, CONF_sshbug_winadj) == FORCE_ON) {
2807 * Servers that don't support our winadj request for one
2808 * reason or another. Currently, none detected automatically.
2810 ssh->remote_bugs |= BUG_CHOKES_ON_WINADJ;
2811 logevent("We believe remote version has winadj bug");
2816 * The `software version' part of an SSH version string is required
2817 * to contain no spaces or minus signs.
2819 static void ssh_fix_verstring(char *str)
2821 /* Eat "<protoversion>-". */
2822 while (*str && *str != '-') str++;
2823 assert(*str == '-'); str++;
2825 /* Convert minus signs and spaces in the remaining string into
2828 if (*str == '-' || *str == ' ')
2835 * Send an appropriate SSH version string.
2837 static void ssh_send_verstring(Ssh ssh, const char *protoname, char *svers)
2841 if (ssh->version == 2) {
2843 * Construct a v2 version string.
2845 verstring = dupprintf("%s2.0-%s\015\012", protoname, sshver);
2848 * Construct a v1 version string.
2850 assert(!strcmp(protoname, "SSH-")); /* no v1 bare connection protocol */
2851 verstring = dupprintf("SSH-%s-%s\012",
2852 (ssh_versioncmp(svers, "1.5") <= 0 ?
2857 ssh_fix_verstring(verstring + strlen(protoname));
2859 if (ssh->version == 2) {
2862 * Record our version string.
2864 len = strcspn(verstring, "\015\012");
2865 ssh->v_c = snewn(len + 1, char);
2866 memcpy(ssh->v_c, verstring, len);
2870 logeventf(ssh, "We claim version: %.*s",
2871 strcspn(verstring, "\015\012"), verstring);
2872 s_write(ssh, verstring, strlen(verstring));
2876 static int do_ssh_init(Ssh ssh, unsigned char c)
2878 static const char protoname[] = "SSH-";
2880 struct do_ssh_init_state {
2889 crState(do_ssh_init_state);
2893 /* Search for a line beginning with the protocol name prefix in
2896 for (s->i = 0; protoname[s->i]; s->i++) {
2897 if ((char)c != protoname[s->i]) goto no;
2907 s->vstrsize = sizeof(protoname) + 16;
2908 s->vstring = snewn(s->vstrsize, char);
2909 strcpy(s->vstring, protoname);
2910 s->vslen = strlen(protoname);
2913 if (s->vslen >= s->vstrsize - 1) {
2915 s->vstring = sresize(s->vstring, s->vstrsize, char);
2917 s->vstring[s->vslen++] = c;
2920 s->version[s->i] = '\0';
2922 } else if (s->i < sizeof(s->version) - 1)
2923 s->version[s->i++] = c;
2924 } else if (c == '\012')
2926 crReturn(1); /* get another char */
2929 ssh->agentfwd_enabled = FALSE;
2930 ssh->rdpkt2_state.incoming_sequence = 0;
2932 s->vstring[s->vslen] = 0;
2933 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2934 logeventf(ssh, "Server version: %s", s->vstring);
2935 ssh_detect_bugs(ssh, s->vstring);
2938 * Decide which SSH protocol version to support.
2941 /* Anything strictly below "2.0" means protocol 1 is supported. */
2942 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2943 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2944 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2946 if (conf_get_int(ssh->conf, CONF_sshprot) == 0 && !s->proto1) {
2947 bombout(("SSH protocol version 1 required by user but not provided by server"));
2950 if (conf_get_int(ssh->conf, CONF_sshprot) == 3 && !s->proto2) {
2951 bombout(("SSH protocol version 2 required by user but not provided by server"));
2955 if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1))
2960 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2962 /* Send the version string, if we haven't already */
2963 if (conf_get_int(ssh->conf, CONF_sshprot) != 3)
2964 ssh_send_verstring(ssh, protoname, s->version);
2966 if (ssh->version == 2) {
2969 * Record their version string.
2971 len = strcspn(s->vstring, "\015\012");
2972 ssh->v_s = snewn(len + 1, char);
2973 memcpy(ssh->v_s, s->vstring, len);
2977 * Initialise SSH-2 protocol.
2979 ssh->protocol = ssh2_protocol;
2980 ssh2_protocol_setup(ssh);
2981 ssh->s_rdpkt = ssh2_rdpkt;
2984 * Initialise SSH-1 protocol.
2986 ssh->protocol = ssh1_protocol;
2987 ssh1_protocol_setup(ssh);
2988 ssh->s_rdpkt = ssh1_rdpkt;
2990 if (ssh->version == 2)
2991 do_ssh2_transport(ssh, NULL, -1, NULL);
2993 update_specials_menu(ssh->frontend);
2994 ssh->state = SSH_STATE_BEFORE_SIZE;
2995 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3002 static int do_ssh_connection_init(Ssh ssh, unsigned char c)
3005 * Ordinary SSH begins with the banner "SSH-x.y-...". This is just
3006 * the ssh-connection part, extracted and given a trivial binary
3007 * packet protocol, so we replace 'SSH-' at the start with a new
3008 * name. In proper SSH style (though of course this part of the
3009 * proper SSH protocol _isn't_ subject to this kind of
3010 * DNS-domain-based extension), we define the new name in our
3013 static const char protoname[] =
3014 "SSHCONNECTION@putty.projects.tartarus.org-";
3016 struct do_ssh_connection_init_state {
3024 crState(do_ssh_connection_init_state);
3028 /* Search for a line beginning with the protocol name prefix in
3031 for (s->i = 0; protoname[s->i]; s->i++) {
3032 if ((char)c != protoname[s->i]) goto no;
3042 s->vstrsize = sizeof(protoname) + 16;
3043 s->vstring = snewn(s->vstrsize, char);
3044 strcpy(s->vstring, protoname);
3045 s->vslen = strlen(protoname);
3048 if (s->vslen >= s->vstrsize - 1) {
3050 s->vstring = sresize(s->vstring, s->vstrsize, char);
3052 s->vstring[s->vslen++] = c;
3055 s->version[s->i] = '\0';
3057 } else if (s->i < sizeof(s->version) - 1)
3058 s->version[s->i++] = c;
3059 } else if (c == '\012')
3061 crReturn(1); /* get another char */
3064 ssh->agentfwd_enabled = FALSE;
3065 ssh->rdpkt2_bare_state.incoming_sequence = 0;
3067 s->vstring[s->vslen] = 0;
3068 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
3069 logeventf(ssh, "Server version: %s", s->vstring);
3070 ssh_detect_bugs(ssh, s->vstring);
3073 * Decide which SSH protocol version to support. This is easy in
3074 * bare ssh-connection mode: only 2.0 is legal.
3076 if (ssh_versioncmp(s->version, "2.0") < 0) {
3077 bombout(("Server announces compatibility with SSH-1 in bare ssh-connection protocol"));
3080 if (conf_get_int(ssh->conf, CONF_sshprot) == 0) {
3081 bombout(("Bare ssh-connection protocol cannot be run in SSH-1-only mode"));
3087 logeventf(ssh, "Using bare ssh-connection protocol");
3089 /* Send the version string, if we haven't already */
3090 ssh_send_verstring(ssh, protoname, s->version);
3093 * Initialise bare connection protocol.
3095 ssh->protocol = ssh2_bare_connection_protocol;
3096 ssh2_bare_connection_protocol_setup(ssh);
3097 ssh->s_rdpkt = ssh2_bare_connection_rdpkt;
3099 update_specials_menu(ssh->frontend);
3100 ssh->state = SSH_STATE_BEFORE_SIZE;
3101 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3104 * Get authconn (really just conn) under way.
3106 do_ssh2_authconn(ssh, NULL, 0, NULL);
3113 static void ssh_process_incoming_data(Ssh ssh,
3114 unsigned char **data, int *datalen)
3116 struct Packet *pktin;
3118 pktin = ssh->s_rdpkt(ssh, data, datalen);
3120 ssh->protocol(ssh, NULL, 0, pktin);
3121 ssh_free_packet(pktin);
3125 static void ssh_queue_incoming_data(Ssh ssh,
3126 unsigned char **data, int *datalen)
3128 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
3133 static void ssh_process_queued_incoming_data(Ssh ssh)
3136 unsigned char *data;
3139 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
3140 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
3144 while (!ssh->frozen && len > 0)
3145 ssh_process_incoming_data(ssh, &data, &len);
3148 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
3152 static void ssh_set_frozen(Ssh ssh, int frozen)
3155 sk_set_frozen(ssh->s, frozen);
3156 ssh->frozen = frozen;
3159 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
3161 /* Log raw data, if we're in that mode. */
3163 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
3164 0, NULL, NULL, 0, NULL);
3166 crBegin(ssh->ssh_gotdata_crstate);
3169 * To begin with, feed the characters one by one to the
3170 * protocol initialisation / selection function do_ssh_init().
3171 * When that returns 0, we're done with the initial greeting
3172 * exchange and can move on to packet discipline.
3175 int ret; /* need not be kept across crReturn */
3177 crReturnV; /* more data please */
3178 ret = ssh->do_ssh_init(ssh, *data);
3186 * We emerge from that loop when the initial negotiation is
3187 * over and we have selected an s_rdpkt function. Now pass
3188 * everything to s_rdpkt, and then pass the resulting packets
3189 * to the proper protocol handler.
3193 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
3195 ssh_queue_incoming_data(ssh, &data, &datalen);
3196 /* This uses up all data and cannot cause anything interesting
3197 * to happen; indeed, for anything to happen at all, we must
3198 * return, so break out. */
3200 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
3201 /* This uses up some or all data, and may freeze the
3203 ssh_process_queued_incoming_data(ssh);
3205 /* This uses up some or all data, and may freeze the
3207 ssh_process_incoming_data(ssh, &data, &datalen);
3209 /* FIXME this is probably EBW. */
3210 if (ssh->state == SSH_STATE_CLOSED)
3213 /* We're out of data. Go and get some more. */
3219 static int ssh_do_close(Ssh ssh, int notify_exit)
3222 struct ssh_channel *c;
3224 ssh->state = SSH_STATE_CLOSED;
3225 expire_timer_context(ssh);
3230 notify_remote_exit(ssh->frontend);
3235 * Now we must shut down any port- and X-forwarded channels going
3236 * through this connection.
3238 if (ssh->channels) {
3239 while (NULL != (c = index234(ssh->channels, 0))) {
3242 x11_close(c->u.x11.xconn);
3245 case CHAN_SOCKDATA_DORMANT:
3246 pfd_close(c->u.pfd.pf);
3249 del234(ssh->channels, c); /* moving next one to index 0 */
3250 if (ssh->version == 2)
3251 bufchain_clear(&c->v.v2.outbuffer);
3256 * Go through port-forwardings, and close any associated
3257 * listening sockets.
3259 if (ssh->portfwds) {
3260 struct ssh_portfwd *pf;
3261 while (NULL != (pf = index234(ssh->portfwds, 0))) {
3262 /* Dispose of any listening socket. */
3264 pfl_terminate(pf->local);
3265 del234(ssh->portfwds, pf); /* moving next one to index 0 */
3268 freetree234(ssh->portfwds);
3269 ssh->portfwds = NULL;
3275 static void ssh_socket_log(Plug plug, int type, SockAddr addr, int port,
3276 const char *error_msg, int error_code)
3278 Ssh ssh = (Ssh) plug;
3279 char addrbuf[256], *msg;
3281 if (ssh->attempting_connshare) {
3283 * While we're attempting connection sharing, don't loudly log
3284 * everything that happens. Real TCP connections need to be
3285 * logged when we _start_ trying to connect, because it might
3286 * be ages before they respond if something goes wrong; but
3287 * connection sharing is local and quick to respond, and it's
3288 * sufficient to simply wait and see whether it worked
3292 sk_getaddr(addr, addrbuf, lenof(addrbuf));
3295 if (sk_addr_needs_port(addr)) {
3296 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
3298 msg = dupprintf("Connecting to %s", addrbuf);
3301 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
3309 void ssh_connshare_log(Ssh ssh, int event, const char *logtext,
3310 const char *ds_err, const char *us_err)
3312 if (event == SHARE_NONE) {
3313 /* In this case, 'logtext' is an error message indicating a
3314 * reason why connection sharing couldn't be set up _at all_.
3315 * Failing that, ds_err and us_err indicate why we couldn't be
3316 * a downstream and an upstream respectively. */
3318 logeventf(ssh, "Could not set up connection sharing: %s", logtext);
3321 logeventf(ssh, "Could not set up connection sharing"
3322 " as downstream: %s", ds_err);
3324 logeventf(ssh, "Could not set up connection sharing"
3325 " as upstream: %s", us_err);
3327 } else if (event == SHARE_DOWNSTREAM) {
3328 /* In this case, 'logtext' is a local endpoint address */
3329 logeventf(ssh, "Using existing shared connection at %s", logtext);
3330 /* Also we should mention this in the console window to avoid
3331 * confusing users as to why this window doesn't behave the
3333 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3334 c_write_str(ssh,"Reusing a shared connection to this server.\r\n");
3336 } else if (event == SHARE_UPSTREAM) {
3337 /* In this case, 'logtext' is a local endpoint address too */
3338 logeventf(ssh, "Sharing this connection at %s", logtext);
3342 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
3345 Ssh ssh = (Ssh) plug;
3346 int need_notify = ssh_do_close(ssh, FALSE);
3349 if (!ssh->close_expected)
3350 error_msg = "Server unexpectedly closed network connection";
3352 error_msg = "Server closed network connection";
3355 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
3359 notify_remote_exit(ssh->frontend);
3362 logevent(error_msg);
3363 if (!ssh->close_expected || !ssh->clean_exit)
3364 connection_fatal(ssh->frontend, "%s", error_msg);
3368 static int ssh_receive(Plug plug, int urgent, char *data, int len)
3370 Ssh ssh = (Ssh) plug;
3371 ssh_gotdata(ssh, (unsigned char *)data, len);
3372 if (ssh->state == SSH_STATE_CLOSED) {
3373 ssh_do_close(ssh, TRUE);
3379 static void ssh_sent(Plug plug, int bufsize)
3381 Ssh ssh = (Ssh) plug;
3383 * If the send backlog on the SSH socket itself clears, we
3384 * should unthrottle the whole world if it was throttled.
3386 if (bufsize < SSH_MAX_BACKLOG)
3387 ssh_throttle_all(ssh, 0, bufsize);
3391 * Connect to specified host and port.
3392 * Returns an error message, or NULL on success.
3393 * Also places the canonical host name into `realhost'. It must be
3394 * freed by the caller.
3396 static const char *connect_to_host(Ssh ssh, char *host, int port,
3397 char **realhost, int nodelay, int keepalive)
3399 static const struct plug_function_table fn_table = {
3410 int addressfamily, sshprot;
3412 loghost = conf_get_str(ssh->conf, CONF_loghost);
3417 tmphost = dupstr(loghost);
3418 ssh->savedport = 22; /* default ssh port */
3421 * A colon suffix on the hostname string also lets us affect
3422 * savedport. (Unless there are multiple colons, in which case
3423 * we assume this is an unbracketed IPv6 literal.)
3425 colon = host_strrchr(tmphost, ':');
3426 if (colon && colon == host_strchr(tmphost, ':')) {
3429 ssh->savedport = atoi(colon);
3432 ssh->savedhost = host_strduptrim(tmphost);
3435 ssh->savedhost = host_strduptrim(host);
3437 port = 22; /* default ssh port */
3438 ssh->savedport = port;
3441 ssh->fn = &fn_table; /* make 'ssh' usable as a Plug */
3444 * Try connection-sharing, in case that means we don't open a
3445 * socket after all. ssh_connection_sharing_init will connect to a
3446 * previously established upstream if it can, and failing that,
3447 * establish a listening socket for _us_ to be the upstream. In
3448 * the latter case it will return NULL just as if it had done
3449 * nothing, because here we only need to care if we're a
3450 * downstream and need to do our connection setup differently.
3452 ssh->connshare = NULL;
3453 ssh->attempting_connshare = TRUE; /* affects socket logging behaviour */
3454 ssh->s = ssh_connection_sharing_init(ssh->savedhost, ssh->savedport,
3455 ssh->conf, ssh, &ssh->connshare);
3456 ssh->attempting_connshare = FALSE;
3457 if (ssh->s != NULL) {
3459 * We are a downstream.
3461 ssh->bare_connection = TRUE;
3462 ssh->do_ssh_init = do_ssh_connection_init;
3463 ssh->fullhostname = NULL;
3464 *realhost = dupstr(host); /* best we can do */
3467 * We're not a downstream, so open a normal socket.
3469 ssh->do_ssh_init = do_ssh_init;
3474 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
3475 logeventf(ssh, "Looking up host \"%s\"%s", host,
3476 (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
3477 (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
3478 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily);
3479 if ((err = sk_addr_error(addr)) != NULL) {
3483 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3485 ssh->s = new_connection(addr, *realhost, port,
3486 0, 1, nodelay, keepalive,
3487 (Plug) ssh, ssh->conf);
3488 if ((err = sk_socket_error(ssh->s)) != NULL) {
3490 notify_remote_exit(ssh->frontend);
3496 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3497 * send the version string too.
3499 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3502 if (sshprot == 3 && !ssh->bare_connection) {
3504 ssh_send_verstring(ssh, "SSH-", NULL);
3508 * loghost, if configured, overrides realhost.
3512 *realhost = dupstr(loghost);
3519 * Throttle or unthrottle the SSH connection.
3521 static void ssh_throttle_conn(Ssh ssh, int adjust)
3523 int old_count = ssh->conn_throttle_count;
3524 ssh->conn_throttle_count += adjust;
3525 assert(ssh->conn_throttle_count >= 0);
3526 if (ssh->conn_throttle_count && !old_count) {
3527 ssh_set_frozen(ssh, 1);
3528 } else if (!ssh->conn_throttle_count && old_count) {
3529 ssh_set_frozen(ssh, 0);
3534 * Throttle or unthrottle _all_ local data streams (for when sends
3535 * on the SSH connection itself back up).
3537 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3540 struct ssh_channel *c;
3542 if (enable == ssh->throttled_all)
3544 ssh->throttled_all = enable;
3545 ssh->overall_bufsize = bufsize;
3548 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3550 case CHAN_MAINSESSION:
3552 * This is treated separately, outside the switch.
3556 x11_override_throttle(c->u.x11.xconn, enable);
3559 /* Agent channels require no buffer management. */
3562 pfd_override_throttle(c->u.pfd.pf, enable);
3568 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3570 Ssh ssh = (Ssh) sshv;
3572 ssh->agent_response = reply;
3573 ssh->agent_response_len = replylen;
3575 if (ssh->version == 1)
3576 do_ssh1_login(ssh, NULL, -1, NULL);
3578 do_ssh2_authconn(ssh, NULL, -1, NULL);
3581 static void ssh_dialog_callback(void *sshv, int ret)
3583 Ssh ssh = (Ssh) sshv;
3585 ssh->user_response = ret;
3587 if (ssh->version == 1)
3588 do_ssh1_login(ssh, NULL, -1, NULL);
3590 do_ssh2_transport(ssh, NULL, -1, NULL);
3593 * This may have unfrozen the SSH connection, so do a
3596 ssh_process_queued_incoming_data(ssh);
3599 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3601 struct ssh_channel *c = (struct ssh_channel *)cv;
3603 void *sentreply = reply;
3605 c->u.a.outstanding_requests--;
3607 /* Fake SSH_AGENT_FAILURE. */
3608 sentreply = "\0\0\0\1\5";
3611 if (ssh->version == 2) {
3612 ssh2_add_channel_data(c, sentreply, replylen);
3615 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3616 PKT_INT, c->remoteid,
3618 PKT_DATA, sentreply, replylen,
3624 * If we've already seen an incoming EOF but haven't sent an
3625 * outgoing one, this may be the moment to send it.
3627 if (c->u.a.outstanding_requests == 0 && (c->closes & CLOSES_RCVD_EOF))
3628 sshfwd_write_eof(c);
3632 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3633 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3634 * => log `wire_reason'.
3636 static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
3637 int code, int clean_exit)
3641 client_reason = wire_reason;
3643 error = dupprintf("Disconnected: %s", client_reason);
3645 error = dupstr("Disconnected");
3647 if (ssh->version == 1) {
3648 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3650 } else if (ssh->version == 2) {
3651 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3652 ssh2_pkt_adduint32(pktout, code);
3653 ssh2_pkt_addstring(pktout, wire_reason);
3654 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3655 ssh2_pkt_send_noqueue(ssh, pktout);
3658 ssh->close_expected = TRUE;
3659 ssh->clean_exit = clean_exit;
3660 ssh_closing((Plug)ssh, error, 0, 0);
3665 * Handle the key exchange and user authentication phases.
3667 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
3668 struct Packet *pktin)
3671 unsigned char cookie[8], *ptr;
3672 struct MD5Context md5c;
3673 struct do_ssh1_login_state {
3676 unsigned char *rsabuf, *keystr1, *keystr2;
3677 unsigned long supported_ciphers_mask, supported_auths_mask;
3678 int tried_publickey, tried_agent;
3679 int tis_auth_refused, ccard_auth_refused;
3680 unsigned char session_id[16];
3682 void *publickey_blob;
3683 int publickey_bloblen;
3684 char *publickey_comment;
3685 int publickey_encrypted;
3686 prompts_t *cur_prompt;
3689 unsigned char request[5], *response, *p;
3699 struct RSAKey servkey, hostkey;
3701 crState(do_ssh1_login_state);
3708 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
3709 bombout(("Public key packet not received"));
3713 logevent("Received public keys");
3715 ptr = ssh_pkt_getdata(pktin, 8);
3717 bombout(("SSH-1 public key packet stopped before random cookie"));
3720 memcpy(cookie, ptr, 8);
3722 if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) ||
3723 !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) {
3724 bombout(("Failed to read SSH-1 public keys from public key packet"));
3729 * Log the host key fingerprint.
3733 logevent("Host key fingerprint is:");
3734 strcpy(logmsg, " ");
3735 s->hostkey.comment = NULL;
3736 rsa_fingerprint(logmsg + strlen(logmsg),
3737 sizeof(logmsg) - strlen(logmsg), &s->hostkey);
3741 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3742 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3743 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
3744 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
3745 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
3747 ssh->v1_local_protoflags =
3748 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3749 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
3752 MD5Update(&md5c, s->keystr2, s->hostkey.bytes);
3753 MD5Update(&md5c, s->keystr1, s->servkey.bytes);
3754 MD5Update(&md5c, cookie, 8);
3755 MD5Final(s->session_id, &md5c);
3757 for (i = 0; i < 32; i++)
3758 ssh->session_key[i] = random_byte();
3761 * Verify that the `bits' and `bytes' parameters match.
3763 if (s->hostkey.bits > s->hostkey.bytes * 8 ||
3764 s->servkey.bits > s->servkey.bytes * 8) {
3765 bombout(("SSH-1 public keys were badly formatted"));
3769 s->len = (s->hostkey.bytes > s->servkey.bytes ?
3770 s->hostkey.bytes : s->servkey.bytes);
3772 s->rsabuf = snewn(s->len, unsigned char);
3775 * Verify the host key.
3779 * First format the key into a string.
3781 int len = rsastr_len(&s->hostkey);
3782 char fingerprint[100];
3783 char *keystr = snewn(len, char);
3784 rsastr_fmt(keystr, &s->hostkey);
3785 rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey);
3787 ssh_set_frozen(ssh, 1);
3788 s->dlgret = verify_ssh_host_key(ssh->frontend,
3789 ssh->savedhost, ssh->savedport,
3790 "rsa", keystr, fingerprint,
3791 ssh_dialog_callback, ssh);
3793 if (s->dlgret < 0) {
3797 bombout(("Unexpected data from server while waiting"
3798 " for user host key response"));
3801 } while (pktin || inlen > 0);
3802 s->dlgret = ssh->user_response;
3804 ssh_set_frozen(ssh, 0);
3806 if (s->dlgret == 0) {
3807 ssh_disconnect(ssh, "User aborted at host key verification",
3813 for (i = 0; i < 32; i++) {
3814 s->rsabuf[i] = ssh->session_key[i];
3816 s->rsabuf[i] ^= s->session_id[i];
3819 if (s->hostkey.bytes > s->servkey.bytes) {
3820 ret = rsaencrypt(s->rsabuf, 32, &s->servkey);
3822 ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey);
3824 ret = rsaencrypt(s->rsabuf, 32, &s->hostkey);
3826 ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey);
3829 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3833 logevent("Encrypted session key");
3836 int cipher_chosen = 0, warn = 0;
3837 char *cipher_string = NULL;
3839 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
3840 int next_cipher = conf_get_int_int(ssh->conf,
3841 CONF_ssh_cipherlist, i);
3842 if (next_cipher == CIPHER_WARN) {
3843 /* If/when we choose a cipher, warn about it */
3845 } else if (next_cipher == CIPHER_AES) {
3846 /* XXX Probably don't need to mention this. */
3847 logevent("AES not supported in SSH-1, skipping");
3849 switch (next_cipher) {
3850 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
3851 cipher_string = "3DES"; break;
3852 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
3853 cipher_string = "Blowfish"; break;
3854 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
3855 cipher_string = "single-DES"; break;
3857 if (s->supported_ciphers_mask & (1 << s->cipher_type))
3861 if (!cipher_chosen) {
3862 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
3863 bombout(("Server violates SSH-1 protocol by not "
3864 "supporting 3DES encryption"));
3866 /* shouldn't happen */
3867 bombout(("No supported ciphers found"));
3871 /* Warn about chosen cipher if necessary. */
3873 ssh_set_frozen(ssh, 1);
3874 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3875 ssh_dialog_callback, ssh);
3876 if (s->dlgret < 0) {
3880 bombout(("Unexpected data from server while waiting"
3881 " for user response"));
3884 } while (pktin || inlen > 0);
3885 s->dlgret = ssh->user_response;
3887 ssh_set_frozen(ssh, 0);
3888 if (s->dlgret == 0) {
3889 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3896 switch (s->cipher_type) {
3897 case SSH_CIPHER_3DES:
3898 logevent("Using 3DES encryption");
3900 case SSH_CIPHER_DES:
3901 logevent("Using single-DES encryption");
3903 case SSH_CIPHER_BLOWFISH:
3904 logevent("Using Blowfish encryption");
3908 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3909 PKT_CHAR, s->cipher_type,
3910 PKT_DATA, cookie, 8,
3911 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3912 PKT_DATA, s->rsabuf, s->len,
3913 PKT_INT, ssh->v1_local_protoflags, PKT_END);
3915 logevent("Trying to enable encryption...");
3919 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3920 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3922 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3923 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
3924 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
3926 ssh->crcda_ctx = crcda_make_context();
3927 logevent("Installing CRC compensation attack detector");
3929 if (s->servkey.modulus) {
3930 sfree(s->servkey.modulus);
3931 s->servkey.modulus = NULL;
3933 if (s->servkey.exponent) {
3934 sfree(s->servkey.exponent);
3935 s->servkey.exponent = NULL;
3937 if (s->hostkey.modulus) {
3938 sfree(s->hostkey.modulus);
3939 s->hostkey.modulus = NULL;
3941 if (s->hostkey.exponent) {
3942 sfree(s->hostkey.exponent);
3943 s->hostkey.exponent = NULL;
3947 if (pktin->type != SSH1_SMSG_SUCCESS) {
3948 bombout(("Encryption not successfully enabled"));
3952 logevent("Successfully started encryption");
3954 fflush(stdout); /* FIXME eh? */
3956 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
3957 int ret; /* need not be kept over crReturn */
3958 s->cur_prompt = new_prompts(ssh->frontend);
3959 s->cur_prompt->to_server = TRUE;
3960 s->cur_prompt->name = dupstr("SSH login name");
3961 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
3962 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3965 crWaitUntil(!pktin);
3966 ret = get_userpass_input(s->cur_prompt, in, inlen);
3971 * Failed to get a username. Terminate.
3973 free_prompts(s->cur_prompt);
3974 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
3977 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
3978 free_prompts(s->cur_prompt);
3981 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
3983 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
3985 if (flags & FLAG_INTERACTIVE &&
3986 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3987 c_write_str(ssh, userlog);
3988 c_write_str(ssh, "\r\n");
3996 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
3997 /* We must not attempt PK auth. Pretend we've already tried it. */
3998 s->tried_publickey = s->tried_agent = 1;
4000 s->tried_publickey = s->tried_agent = 0;
4002 s->tis_auth_refused = s->ccard_auth_refused = 0;
4004 * Load the public half of any configured keyfile for later use.
4006 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4007 if (!filename_is_null(s->keyfile)) {
4009 logeventf(ssh, "Reading private key file \"%.150s\"",
4010 filename_to_str(s->keyfile));
4011 keytype = key_type(s->keyfile);
4012 if (keytype == SSH_KEYTYPE_SSH1) {
4014 if (rsakey_pubblob(s->keyfile,
4015 &s->publickey_blob, &s->publickey_bloblen,
4016 &s->publickey_comment, &error)) {
4017 s->publickey_encrypted = rsakey_encrypted(s->keyfile,
4021 logeventf(ssh, "Unable to load private key (%s)", error);
4022 msgbuf = dupprintf("Unable to load private key file "
4023 "\"%.150s\" (%s)\r\n",
4024 filename_to_str(s->keyfile),
4026 c_write_str(ssh, msgbuf);
4028 s->publickey_blob = NULL;
4032 logeventf(ssh, "Unable to use this key file (%s)",
4033 key_type_to_str(keytype));
4034 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4036 filename_to_str(s->keyfile),
4037 key_type_to_str(keytype));
4038 c_write_str(ssh, msgbuf);
4040 s->publickey_blob = NULL;
4043 s->publickey_blob = NULL;
4045 while (pktin->type == SSH1_SMSG_FAILURE) {
4046 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
4048 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
4050 * Attempt RSA authentication using Pageant.
4056 logevent("Pageant is running. Requesting keys.");
4058 /* Request the keys held by the agent. */
4059 PUT_32BIT(s->request, 1);
4060 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
4061 if (!agent_query(s->request, 5, &r, &s->responselen,
4062 ssh_agent_callback, ssh)) {
4066 bombout(("Unexpected data from server while waiting"
4067 " for agent response"));
4070 } while (pktin || inlen > 0);
4071 r = ssh->agent_response;
4072 s->responselen = ssh->agent_response_len;
4074 s->response = (unsigned char *) r;
4075 if (s->response && s->responselen >= 5 &&
4076 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
4077 s->p = s->response + 5;
4078 s->nkeys = toint(GET_32BIT(s->p));
4080 logeventf(ssh, "Pageant reported negative key count %d",
4085 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
4086 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4087 unsigned char *pkblob = s->p;
4091 do { /* do while (0) to make breaking easy */
4092 n = ssh1_read_bignum
4093 (s->p, toint(s->responselen-(s->p-s->response)),
4098 n = ssh1_read_bignum
4099 (s->p, toint(s->responselen-(s->p-s->response)),
4104 if (s->responselen - (s->p-s->response) < 4)
4106 s->commentlen = toint(GET_32BIT(s->p));
4108 if (s->commentlen < 0 ||
4109 toint(s->responselen - (s->p-s->response)) <
4112 s->commentp = (char *)s->p;
4113 s->p += s->commentlen;
4117 logevent("Pageant key list packet was truncated");
4121 if (s->publickey_blob) {
4122 if (!memcmp(pkblob, s->publickey_blob,
4123 s->publickey_bloblen)) {
4124 logeventf(ssh, "Pageant key #%d matches "
4125 "configured key file", s->keyi);
4126 s->tried_publickey = 1;
4128 /* Skip non-configured key */
4131 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
4132 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4133 PKT_BIGNUM, s->key.modulus, PKT_END);
4135 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4136 logevent("Key refused");
4139 logevent("Received RSA challenge");
4140 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4141 bombout(("Server's RSA challenge was badly formatted"));
4146 char *agentreq, *q, *ret;
4149 len = 1 + 4; /* message type, bit count */
4150 len += ssh1_bignum_length(s->key.exponent);
4151 len += ssh1_bignum_length(s->key.modulus);
4152 len += ssh1_bignum_length(s->challenge);
4153 len += 16; /* session id */
4154 len += 4; /* response format */
4155 agentreq = snewn(4 + len, char);
4156 PUT_32BIT(agentreq, len);
4158 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
4159 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
4161 q += ssh1_write_bignum(q, s->key.exponent);
4162 q += ssh1_write_bignum(q, s->key.modulus);
4163 q += ssh1_write_bignum(q, s->challenge);
4164 memcpy(q, s->session_id, 16);
4166 PUT_32BIT(q, 1); /* response format */
4167 if (!agent_query(agentreq, len + 4, &vret, &retlen,
4168 ssh_agent_callback, ssh)) {
4173 bombout(("Unexpected data from server"
4174 " while waiting for agent"
4178 } while (pktin || inlen > 0);
4179 vret = ssh->agent_response;
4180 retlen = ssh->agent_response_len;
4185 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
4186 logevent("Sending Pageant's response");
4187 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4188 PKT_DATA, ret + 5, 16,
4192 if (pktin->type == SSH1_SMSG_SUCCESS) {
4194 ("Pageant's response accepted");
4195 if (flags & FLAG_VERBOSE) {
4196 c_write_str(ssh, "Authenticated using"
4198 c_write(ssh, s->commentp,
4200 c_write_str(ssh, "\" from agent\r\n");
4205 ("Pageant's response not accepted");
4208 ("Pageant failed to answer challenge");
4212 logevent("No reply received from Pageant");
4215 freebn(s->key.exponent);
4216 freebn(s->key.modulus);
4217 freebn(s->challenge);
4222 if (s->publickey_blob && !s->tried_publickey)
4223 logevent("Configured key file not in Pageant");
4225 logevent("Failed to get reply from Pageant");
4230 if (s->publickey_blob && !s->tried_publickey) {
4232 * Try public key authentication with the specified
4235 int got_passphrase; /* need not be kept over crReturn */
4236 if (flags & FLAG_VERBOSE)
4237 c_write_str(ssh, "Trying public key authentication.\r\n");
4238 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4239 logeventf(ssh, "Trying public key \"%s\"",
4240 filename_to_str(s->keyfile));
4241 s->tried_publickey = 1;
4242 got_passphrase = FALSE;
4243 while (!got_passphrase) {
4245 * Get a passphrase, if necessary.
4247 char *passphrase = NULL; /* only written after crReturn */
4249 if (!s->publickey_encrypted) {
4250 if (flags & FLAG_VERBOSE)
4251 c_write_str(ssh, "No passphrase required.\r\n");
4254 int ret; /* need not be kept over crReturn */
4255 s->cur_prompt = new_prompts(ssh->frontend);
4256 s->cur_prompt->to_server = FALSE;
4257 s->cur_prompt->name = dupstr("SSH key passphrase");
4258 add_prompt(s->cur_prompt,
4259 dupprintf("Passphrase for key \"%.100s\": ",
4260 s->publickey_comment), FALSE);
4261 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4264 crWaitUntil(!pktin);
4265 ret = get_userpass_input(s->cur_prompt, in, inlen);
4269 /* Failed to get a passphrase. Terminate. */
4270 free_prompts(s->cur_prompt);
4271 ssh_disconnect(ssh, NULL, "Unable to authenticate",
4275 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
4276 free_prompts(s->cur_prompt);
4279 * Try decrypting key with passphrase.
4281 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4282 ret = loadrsakey(s->keyfile, &s->key, passphrase,
4285 smemclr(passphrase, strlen(passphrase));
4289 /* Correct passphrase. */
4290 got_passphrase = TRUE;
4291 } else if (ret == 0) {
4292 c_write_str(ssh, "Couldn't load private key from ");
4293 c_write_str(ssh, filename_to_str(s->keyfile));
4294 c_write_str(ssh, " (");
4295 c_write_str(ssh, error);
4296 c_write_str(ssh, ").\r\n");
4297 got_passphrase = FALSE;
4298 break; /* go and try something else */
4299 } else if (ret == -1) {
4300 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
4301 got_passphrase = FALSE;
4304 assert(0 && "unexpected return from loadrsakey()");
4305 got_passphrase = FALSE; /* placate optimisers */
4309 if (got_passphrase) {
4312 * Send a public key attempt.
4314 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4315 PKT_BIGNUM, s->key.modulus, PKT_END);
4318 if (pktin->type == SSH1_SMSG_FAILURE) {
4319 c_write_str(ssh, "Server refused our public key.\r\n");
4320 continue; /* go and try something else */
4322 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4323 bombout(("Bizarre response to offer of public key"));
4329 unsigned char buffer[32];
4330 Bignum challenge, response;
4332 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4333 bombout(("Server's RSA challenge was badly formatted"));
4336 response = rsadecrypt(challenge, &s->key);
4337 freebn(s->key.private_exponent);/* burn the evidence */
4339 for (i = 0; i < 32; i++) {
4340 buffer[i] = bignum_byte(response, 31 - i);
4344 MD5Update(&md5c, buffer, 32);
4345 MD5Update(&md5c, s->session_id, 16);
4346 MD5Final(buffer, &md5c);
4348 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4349 PKT_DATA, buffer, 16, PKT_END);
4356 if (pktin->type == SSH1_SMSG_FAILURE) {
4357 if (flags & FLAG_VERBOSE)
4358 c_write_str(ssh, "Failed to authenticate with"
4359 " our public key.\r\n");
4360 continue; /* go and try something else */
4361 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4362 bombout(("Bizarre response to RSA authentication response"));
4366 break; /* we're through! */
4372 * Otherwise, try various forms of password-like authentication.
4374 s->cur_prompt = new_prompts(ssh->frontend);
4376 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4377 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
4378 !s->tis_auth_refused) {
4379 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
4380 logevent("Requested TIS authentication");
4381 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
4383 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
4384 logevent("TIS authentication declined");
4385 if (flags & FLAG_INTERACTIVE)
4386 c_write_str(ssh, "TIS authentication refused.\r\n");
4387 s->tis_auth_refused = 1;
4392 char *instr_suf, *prompt;
4394 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4396 bombout(("TIS challenge packet was badly formed"));
4399 logevent("Received TIS challenge");
4400 s->cur_prompt->to_server = TRUE;
4401 s->cur_prompt->name = dupstr("SSH TIS authentication");
4402 /* Prompt heuristic comes from OpenSSH */
4403 if (memchr(challenge, '\n', challengelen)) {
4404 instr_suf = dupstr("");
4405 prompt = dupprintf("%.*s", challengelen, challenge);
4407 instr_suf = dupprintf("%.*s", challengelen, challenge);
4408 prompt = dupstr("Response: ");
4410 s->cur_prompt->instruction =
4411 dupprintf("Using TIS authentication.%s%s",
4412 (*instr_suf) ? "\n" : "",
4414 s->cur_prompt->instr_reqd = TRUE;
4415 add_prompt(s->cur_prompt, prompt, FALSE);
4419 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4420 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
4421 !s->ccard_auth_refused) {
4422 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
4423 logevent("Requested CryptoCard authentication");
4424 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
4426 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
4427 logevent("CryptoCard authentication declined");
4428 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4429 s->ccard_auth_refused = 1;
4434 char *instr_suf, *prompt;
4436 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4438 bombout(("CryptoCard challenge packet was badly formed"));
4441 logevent("Received CryptoCard challenge");
4442 s->cur_prompt->to_server = TRUE;
4443 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4444 s->cur_prompt->name_reqd = FALSE;
4445 /* Prompt heuristic comes from OpenSSH */
4446 if (memchr(challenge, '\n', challengelen)) {
4447 instr_suf = dupstr("");
4448 prompt = dupprintf("%.*s", challengelen, challenge);
4450 instr_suf = dupprintf("%.*s", challengelen, challenge);
4451 prompt = dupstr("Response: ");
4453 s->cur_prompt->instruction =
4454 dupprintf("Using CryptoCard authentication.%s%s",
4455 (*instr_suf) ? "\n" : "",
4457 s->cur_prompt->instr_reqd = TRUE;
4458 add_prompt(s->cur_prompt, prompt, FALSE);
4462 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4463 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4464 bombout(("No supported authentication methods available"));
4467 s->cur_prompt->to_server = TRUE;
4468 s->cur_prompt->name = dupstr("SSH password");
4469 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4470 ssh->username, ssh->savedhost),
4475 * Show password prompt, having first obtained it via a TIS
4476 * or CryptoCard exchange if we're doing TIS or CryptoCard
4480 int ret; /* need not be kept over crReturn */
4481 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4484 crWaitUntil(!pktin);
4485 ret = get_userpass_input(s->cur_prompt, in, inlen);
4490 * Failed to get a password (for example
4491 * because one was supplied on the command line
4492 * which has already failed to work). Terminate.
4494 free_prompts(s->cur_prompt);
4495 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4500 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4502 * Defence against traffic analysis: we send a
4503 * whole bunch of packets containing strings of
4504 * different lengths. One of these strings is the
4505 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4506 * The others are all random data in
4507 * SSH1_MSG_IGNORE packets. This way a passive
4508 * listener can't tell which is the password, and
4509 * hence can't deduce the password length.
4511 * Anybody with a password length greater than 16
4512 * bytes is going to have enough entropy in their
4513 * password that a listener won't find it _that_
4514 * much help to know how long it is. So what we'll
4517 * - if password length < 16, we send 15 packets
4518 * containing string lengths 1 through 15
4520 * - otherwise, we let N be the nearest multiple
4521 * of 8 below the password length, and send 8
4522 * packets containing string lengths N through
4523 * N+7. This won't obscure the order of
4524 * magnitude of the password length, but it will
4525 * introduce a bit of extra uncertainty.
4527 * A few servers can't deal with SSH1_MSG_IGNORE, at
4528 * least in this context. For these servers, we need
4529 * an alternative defence. We make use of the fact
4530 * that the password is interpreted as a C string:
4531 * so we can append a NUL, then some random data.
4533 * A few servers can deal with neither SSH1_MSG_IGNORE
4534 * here _nor_ a padded password string.
4535 * For these servers we are left with no defences
4536 * against password length sniffing.
4538 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4539 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4541 * The server can deal with SSH1_MSG_IGNORE, so
4542 * we can use the primary defence.
4544 int bottom, top, pwlen, i;
4547 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4549 bottom = 0; /* zero length passwords are OK! :-) */
4552 bottom = pwlen & ~7;
4556 assert(pwlen >= bottom && pwlen <= top);
4558 randomstr = snewn(top + 1, char);
4560 for (i = bottom; i <= top; i++) {
4562 defer_packet(ssh, s->pwpkt_type,
4563 PKT_STR,s->cur_prompt->prompts[0]->result,
4566 for (j = 0; j < i; j++) {
4568 randomstr[j] = random_byte();
4569 } while (randomstr[j] == '\0');
4571 randomstr[i] = '\0';
4572 defer_packet(ssh, SSH1_MSG_IGNORE,
4573 PKT_STR, randomstr, PKT_END);
4576 logevent("Sending password with camouflage packets");
4577 ssh_pkt_defersend(ssh);
4580 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4582 * The server can't deal with SSH1_MSG_IGNORE
4583 * but can deal with padded passwords, so we
4584 * can use the secondary defence.
4590 len = strlen(s->cur_prompt->prompts[0]->result);
4591 if (len < sizeof(string)) {
4593 strcpy(string, s->cur_prompt->prompts[0]->result);
4594 len++; /* cover the zero byte */
4595 while (len < sizeof(string)) {
4596 string[len++] = (char) random_byte();
4599 ss = s->cur_prompt->prompts[0]->result;
4601 logevent("Sending length-padded password");
4602 send_packet(ssh, s->pwpkt_type,
4603 PKT_INT, len, PKT_DATA, ss, len,
4607 * The server is believed unable to cope with
4608 * any of our password camouflage methods.
4611 len = strlen(s->cur_prompt->prompts[0]->result);
4612 logevent("Sending unpadded password");
4613 send_packet(ssh, s->pwpkt_type,
4615 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4619 send_packet(ssh, s->pwpkt_type,
4620 PKT_STR, s->cur_prompt->prompts[0]->result,
4623 logevent("Sent password");
4624 free_prompts(s->cur_prompt);
4626 if (pktin->type == SSH1_SMSG_FAILURE) {
4627 if (flags & FLAG_VERBOSE)
4628 c_write_str(ssh, "Access denied\r\n");
4629 logevent("Authentication refused");
4630 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4631 bombout(("Strange packet received, type %d", pktin->type));
4637 if (s->publickey_blob) {
4638 sfree(s->publickey_blob);
4639 sfree(s->publickey_comment);
4642 logevent("Authentication successful");
4647 static void ssh_channel_try_eof(struct ssh_channel *c)
4650 assert(c->pending_eof); /* precondition for calling us */
4652 return; /* can't close: not even opened yet */
4653 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4654 return; /* can't send EOF: pending outgoing data */
4656 c->pending_eof = FALSE; /* we're about to send it */
4657 if (ssh->version == 1) {
4658 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4660 c->closes |= CLOSES_SENT_EOF;
4662 struct Packet *pktout;
4663 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4664 ssh2_pkt_adduint32(pktout, c->remoteid);
4665 ssh2_pkt_send(ssh, pktout);
4666 c->closes |= CLOSES_SENT_EOF;
4667 ssh2_channel_check_close(c);
4671 Conf *sshfwd_get_conf(struct ssh_channel *c)
4677 void sshfwd_write_eof(struct ssh_channel *c)
4681 if (ssh->state == SSH_STATE_CLOSED)
4684 if (c->closes & CLOSES_SENT_EOF)
4687 c->pending_eof = TRUE;
4688 ssh_channel_try_eof(c);
4691 void sshfwd_unclean_close(struct ssh_channel *c, const char *err)
4695 if (ssh->state == SSH_STATE_CLOSED)
4700 x11_close(c->u.x11.xconn);
4701 logeventf(ssh, "Forwarded X11 connection terminated due to local "
4705 case CHAN_SOCKDATA_DORMANT:
4706 pfd_close(c->u.pfd.pf);
4707 logeventf(ssh, "Forwarded port closed due to local error: %s", err);
4710 c->type = CHAN_ZOMBIE;
4711 c->pending_eof = FALSE; /* this will confuse a zombie channel */
4713 ssh2_channel_check_close(c);
4716 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
4720 if (ssh->state == SSH_STATE_CLOSED)
4723 if (ssh->version == 1) {
4724 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
4725 PKT_INT, c->remoteid,
4726 PKT_INT, len, PKT_DATA, buf, len,
4729 * In SSH-1 we can return 0 here - implying that forwarded
4730 * connections are never individually throttled - because
4731 * the only circumstance that can cause throttling will be
4732 * the whole SSH connection backing up, in which case
4733 * _everything_ will be throttled as a whole.
4737 ssh2_add_channel_data(c, buf, len);
4738 return ssh2_try_send(c);
4742 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4747 if (ssh->state == SSH_STATE_CLOSED)
4750 if (ssh->version == 1) {
4751 buflimit = SSH1_BUFFER_LIMIT;
4753 buflimit = c->v.v2.locmaxwin;
4754 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
4756 if (c->throttling_conn && bufsize <= buflimit) {
4757 c->throttling_conn = 0;
4758 ssh_throttle_conn(ssh, -1);
4762 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
4764 struct queued_handler *qh = ssh->qhead;
4768 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
4771 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
4772 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
4775 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
4776 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
4780 ssh->qhead = qh->next;
4782 if (ssh->qhead->msg1 > 0) {
4783 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4784 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
4786 if (ssh->qhead->msg2 > 0) {
4787 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4788 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
4791 ssh->qhead = ssh->qtail = NULL;
4794 qh->handler(ssh, pktin, qh->ctx);
4799 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
4800 chandler_fn_t handler, void *ctx)
4802 struct queued_handler *qh;
4804 qh = snew(struct queued_handler);
4807 qh->handler = handler;
4811 if (ssh->qtail == NULL) {
4815 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4816 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
4819 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4820 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
4823 ssh->qtail->next = qh;
4828 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
4830 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
4832 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
4833 SSH2_MSG_REQUEST_SUCCESS)) {
4834 logeventf(ssh, "Remote port forwarding from %s enabled",
4837 logeventf(ssh, "Remote port forwarding from %s refused",
4840 rpf = del234(ssh->rportfwds, pf);
4842 pf->pfrec->remote = NULL;
4847 int ssh_alloc_sharing_rportfwd(Ssh ssh, const char *shost, int sport,
4850 struct ssh_rportfwd *pf = snew(struct ssh_rportfwd);
4853 pf->share_ctx = share_ctx;
4854 pf->shost = dupstr(shost);
4856 pf->sportdesc = NULL;
4857 if (!ssh->rportfwds) {
4858 assert(ssh->version == 2);
4859 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4861 if (add234(ssh->rportfwds, pf) != pf) {
4869 static void ssh_sharing_global_request_response(Ssh ssh, struct Packet *pktin,
4872 share_got_pkt_from_server(ctx, pktin->type,
4873 pktin->body, pktin->length);
4876 void ssh_sharing_queue_global_request(Ssh ssh, void *share_ctx)
4878 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, SSH2_MSG_REQUEST_FAILURE,
4879 ssh_sharing_global_request_response, share_ctx);
4882 static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
4884 struct ssh_portfwd *epf;
4888 if (!ssh->portfwds) {
4889 ssh->portfwds = newtree234(ssh_portcmp);
4892 * Go through the existing port forwardings and tag them
4893 * with status==DESTROY. Any that we want to keep will be
4894 * re-enabled (status==KEEP) as we go through the
4895 * configuration and find out which bits are the same as
4898 struct ssh_portfwd *epf;
4900 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4901 epf->status = DESTROY;
4904 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
4906 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
4907 char *kp, *kp2, *vp, *vp2;
4908 char address_family, type;
4909 int sport,dport,sserv,dserv;
4910 char *sports, *dports, *saddr, *host;
4914 address_family = 'A';
4916 if (*kp == 'A' || *kp == '4' || *kp == '6')
4917 address_family = *kp++;
4918 if (*kp == 'L' || *kp == 'R')
4921 if ((kp2 = host_strchr(kp, ':')) != NULL) {
4923 * There's a colon in the middle of the source port
4924 * string, which means that the part before it is
4925 * actually a source address.
4927 char *saddr_tmp = dupprintf("%.*s", (int)(kp2 - kp), kp);
4928 saddr = host_strduptrim(saddr_tmp);
4935 sport = atoi(sports);
4939 sport = net_service_lookup(sports);
4941 logeventf(ssh, "Service lookup failed for source"
4942 " port \"%s\"", sports);
4946 if (type == 'L' && !strcmp(val, "D")) {
4947 /* dynamic forwarding */
4954 /* ordinary forwarding */
4956 vp2 = vp + host_strcspn(vp, ":");
4957 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
4961 dport = atoi(dports);
4965 dport = net_service_lookup(dports);
4967 logeventf(ssh, "Service lookup failed for destination"
4968 " port \"%s\"", dports);
4973 if (sport && dport) {
4974 /* Set up a description of the source port. */
4975 struct ssh_portfwd *pfrec, *epfrec;
4977 pfrec = snew(struct ssh_portfwd);
4979 pfrec->saddr = saddr;
4980 pfrec->sserv = sserv ? dupstr(sports) : NULL;
4981 pfrec->sport = sport;
4982 pfrec->daddr = host;
4983 pfrec->dserv = dserv ? dupstr(dports) : NULL;
4984 pfrec->dport = dport;
4985 pfrec->local = NULL;
4986 pfrec->remote = NULL;
4987 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
4988 address_family == '6' ? ADDRTYPE_IPV6 :
4991 epfrec = add234(ssh->portfwds, pfrec);
4992 if (epfrec != pfrec) {
4993 if (epfrec->status == DESTROY) {
4995 * We already have a port forwarding up and running
4996 * with precisely these parameters. Hence, no need
4997 * to do anything; simply re-tag the existing one
5000 epfrec->status = KEEP;
5003 * Anything else indicates that there was a duplicate
5004 * in our input, which we'll silently ignore.
5006 free_portfwd(pfrec);
5008 pfrec->status = CREATE;
5017 * Now go through and destroy any port forwardings which were
5020 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5021 if (epf->status == DESTROY) {
5024 message = dupprintf("%s port forwarding from %s%s%d",
5025 epf->type == 'L' ? "local" :
5026 epf->type == 'R' ? "remote" : "dynamic",
5027 epf->saddr ? epf->saddr : "",
5028 epf->saddr ? ":" : "",
5031 if (epf->type != 'D') {
5032 char *msg2 = dupprintf("%s to %s:%d", message,
5033 epf->daddr, epf->dport);
5038 logeventf(ssh, "Cancelling %s", message);
5041 /* epf->remote or epf->local may be NULL if setting up a
5042 * forwarding failed. */
5044 struct ssh_rportfwd *rpf = epf->remote;
5045 struct Packet *pktout;
5048 * Cancel the port forwarding at the server
5051 if (ssh->version == 1) {
5053 * We cannot cancel listening ports on the
5054 * server side in SSH-1! There's no message
5055 * to support it. Instead, we simply remove
5056 * the rportfwd record from the local end
5057 * so that any connections the server tries
5058 * to make on it are rejected.
5061 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5062 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
5063 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
5065 ssh2_pkt_addstring(pktout, epf->saddr);
5066 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5067 /* XXX: rport_acceptall may not represent
5068 * what was used to open the original connection,
5069 * since it's reconfigurable. */
5070 ssh2_pkt_addstring(pktout, "");
5072 ssh2_pkt_addstring(pktout, "localhost");
5074 ssh2_pkt_adduint32(pktout, epf->sport);
5075 ssh2_pkt_send(ssh, pktout);
5078 del234(ssh->rportfwds, rpf);
5080 } else if (epf->local) {
5081 pfl_terminate(epf->local);
5084 delpos234(ssh->portfwds, i);
5086 i--; /* so we don't skip one in the list */
5090 * And finally, set up any new port forwardings (status==CREATE).
5092 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5093 if (epf->status == CREATE) {
5094 char *sportdesc, *dportdesc;
5095 sportdesc = dupprintf("%s%s%s%s%d%s",
5096 epf->saddr ? epf->saddr : "",
5097 epf->saddr ? ":" : "",
5098 epf->sserv ? epf->sserv : "",
5099 epf->sserv ? "(" : "",
5101 epf->sserv ? ")" : "");
5102 if (epf->type == 'D') {
5105 dportdesc = dupprintf("%s:%s%s%d%s",
5107 epf->dserv ? epf->dserv : "",
5108 epf->dserv ? "(" : "",
5110 epf->dserv ? ")" : "");
5113 if (epf->type == 'L') {
5114 char *err = pfl_listen(epf->daddr, epf->dport,
5115 epf->saddr, epf->sport,
5116 ssh, conf, &epf->local,
5117 epf->addressfamily);
5119 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
5120 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5121 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5122 sportdesc, dportdesc,
5123 err ? " failed: " : "", err ? err : "");
5126 } else if (epf->type == 'D') {
5127 char *err = pfl_listen(NULL, -1, epf->saddr, epf->sport,
5128 ssh, conf, &epf->local,
5129 epf->addressfamily);
5131 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
5132 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5133 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5135 err ? " failed: " : "", err ? err : "");
5140 struct ssh_rportfwd *pf;
5143 * Ensure the remote port forwardings tree exists.
5145 if (!ssh->rportfwds) {
5146 if (ssh->version == 1)
5147 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
5149 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5152 pf = snew(struct ssh_rportfwd);
5153 pf->share_ctx = NULL;
5154 pf->dhost = dupstr(epf->daddr);
5155 pf->dport = epf->dport;
5157 pf->shost = dupstr(epf->saddr);
5158 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5159 pf->shost = dupstr("");
5161 pf->shost = dupstr("localhost");
5163 pf->sport = epf->sport;
5164 if (add234(ssh->rportfwds, pf) != pf) {
5165 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
5166 epf->daddr, epf->dport);
5169 logeventf(ssh, "Requesting remote port %s"
5170 " forward to %s", sportdesc, dportdesc);
5172 pf->sportdesc = sportdesc;
5177 if (ssh->version == 1) {
5178 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
5179 PKT_INT, epf->sport,
5180 PKT_STR, epf->daddr,
5181 PKT_INT, epf->dport,
5183 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
5185 ssh_rportfwd_succfail, pf);
5187 struct Packet *pktout;
5188 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5189 ssh2_pkt_addstring(pktout, "tcpip-forward");
5190 ssh2_pkt_addbool(pktout, 1);/* want reply */
5191 ssh2_pkt_addstring(pktout, pf->shost);
5192 ssh2_pkt_adduint32(pktout, pf->sport);
5193 ssh2_pkt_send(ssh, pktout);
5195 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
5196 SSH2_MSG_REQUEST_FAILURE,
5197 ssh_rportfwd_succfail, pf);
5206 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
5209 int stringlen, bufsize;
5211 ssh_pkt_getstring(pktin, &string, &stringlen);
5212 if (string == NULL) {
5213 bombout(("Incoming terminal data packet was badly formed"));
5217 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
5219 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
5220 ssh->v1_stdout_throttling = 1;
5221 ssh_throttle_conn(ssh, +1);
5225 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
5227 /* Remote side is trying to open a channel to talk to our
5228 * X-Server. Give them back a local channel number. */
5229 struct ssh_channel *c;
5230 int remoteid = ssh_pkt_getuint32(pktin);
5232 logevent("Received X11 connect request");
5233 /* Refuse if X11 forwarding is disabled. */
5234 if (!ssh->X11_fwd_enabled) {
5235 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5236 PKT_INT, remoteid, PKT_END);
5237 logevent("Rejected X11 connect request");
5239 c = snew(struct ssh_channel);
5242 c->u.x11.xconn = x11_init(ssh->x11authtree, c, NULL, -1);
5243 c->remoteid = remoteid;
5244 c->halfopen = FALSE;
5245 c->localid = alloc_channel_id(ssh);
5247 c->pending_eof = FALSE;
5248 c->throttling_conn = 0;
5249 c->type = CHAN_X11; /* identify channel type */
5250 add234(ssh->channels, c);
5251 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5252 PKT_INT, c->remoteid, PKT_INT,
5253 c->localid, PKT_END);
5254 logevent("Opened X11 forward channel");
5258 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
5260 /* Remote side is trying to open a channel to talk to our
5261 * agent. Give them back a local channel number. */
5262 struct ssh_channel *c;
5263 int remoteid = ssh_pkt_getuint32(pktin);
5265 /* Refuse if agent forwarding is disabled. */
5266 if (!ssh->agentfwd_enabled) {
5267 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5268 PKT_INT, remoteid, PKT_END);
5270 c = snew(struct ssh_channel);
5272 c->remoteid = remoteid;
5273 c->halfopen = FALSE;
5274 c->localid = alloc_channel_id(ssh);
5276 c->pending_eof = FALSE;
5277 c->throttling_conn = 0;
5278 c->type = CHAN_AGENT; /* identify channel type */
5279 c->u.a.lensofar = 0;
5280 c->u.a.message = NULL;
5281 c->u.a.outstanding_requests = 0;
5282 add234(ssh->channels, c);
5283 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5284 PKT_INT, c->remoteid, PKT_INT, c->localid,
5289 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
5291 /* Remote side is trying to open a channel to talk to a
5292 * forwarded port. Give them back a local channel number. */
5293 struct ssh_rportfwd pf, *pfp;
5299 remoteid = ssh_pkt_getuint32(pktin);
5300 ssh_pkt_getstring(pktin, &host, &hostsize);
5301 port = ssh_pkt_getuint32(pktin);
5303 pf.dhost = dupprintf("%.*s", hostsize, host);
5305 pfp = find234(ssh->rportfwds, &pf, NULL);
5308 logeventf(ssh, "Rejected remote port open request for %s:%d",
5310 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5311 PKT_INT, remoteid, PKT_END);
5313 struct ssh_channel *c = snew(struct ssh_channel);
5316 logeventf(ssh, "Received remote port open request for %s:%d",
5318 err = pfd_connect(&c->u.pfd.pf, pf.dhost, port,
5319 c, ssh->conf, pfp->pfrec->addressfamily);
5321 logeventf(ssh, "Port open failed: %s", err);
5324 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5325 PKT_INT, remoteid, PKT_END);
5327 c->remoteid = remoteid;
5328 c->halfopen = FALSE;
5329 c->localid = alloc_channel_id(ssh);
5331 c->pending_eof = FALSE;
5332 c->throttling_conn = 0;
5333 c->type = CHAN_SOCKDATA; /* identify channel type */
5334 add234(ssh->channels, c);
5335 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5336 PKT_INT, c->remoteid, PKT_INT,
5337 c->localid, PKT_END);
5338 logevent("Forwarded port opened successfully");
5345 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5347 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5348 unsigned int localid = ssh_pkt_getuint32(pktin);
5349 struct ssh_channel *c;
5351 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5352 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5353 c->remoteid = localid;
5354 c->halfopen = FALSE;
5355 c->type = CHAN_SOCKDATA;
5356 c->throttling_conn = 0;
5357 pfd_confirm(c->u.pfd.pf);
5360 if (c && c->pending_eof) {
5362 * We have a pending close on this channel,
5363 * which we decided on before the server acked
5364 * the channel open. So now we know the
5365 * remoteid, we can close it again.
5367 ssh_channel_try_eof(c);
5371 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5373 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5374 struct ssh_channel *c;
5376 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5377 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5378 logevent("Forwarded connection refused by server");
5379 pfd_close(c->u.pfd.pf);
5380 del234(ssh->channels, c);
5385 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
5387 /* Remote side closes a channel. */
5388 unsigned i = ssh_pkt_getuint32(pktin);
5389 struct ssh_channel *c;
5390 c = find234(ssh->channels, &i, ssh_channelfind);
5391 if (c && !c->halfopen) {
5393 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
5394 !(c->closes & CLOSES_RCVD_EOF)) {
5396 * Received CHANNEL_CLOSE, which we translate into
5399 int send_close = FALSE;
5401 c->closes |= CLOSES_RCVD_EOF;
5406 x11_send_eof(c->u.x11.xconn);
5412 pfd_send_eof(c->u.pfd.pf);
5421 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
5422 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
5424 c->closes |= CLOSES_SENT_EOF;
5428 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
5429 !(c->closes & CLOSES_RCVD_CLOSE)) {
5431 if (!(c->closes & CLOSES_SENT_EOF)) {
5432 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
5433 " for which we never sent CHANNEL_CLOSE\n", i));
5436 c->closes |= CLOSES_RCVD_CLOSE;
5439 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
5440 !(c->closes & CLOSES_SENT_CLOSE)) {
5441 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
5442 PKT_INT, c->remoteid, PKT_END);
5443 c->closes |= CLOSES_SENT_CLOSE;
5446 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5447 ssh_channel_destroy(c);
5449 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5450 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
5451 "_CONFIRMATION", c ? "half-open" : "nonexistent",
5456 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5458 /* Data sent down one of our channels. */
5459 int i = ssh_pkt_getuint32(pktin);
5462 struct ssh_channel *c;
5464 ssh_pkt_getstring(pktin, &p, &len);
5466 c = find234(ssh->channels, &i, ssh_channelfind);
5471 bufsize = x11_send(c->u.x11.xconn, p, len);
5474 bufsize = pfd_send(c->u.pfd.pf, p, len);
5477 /* Data for an agent message. Buffer it. */
5479 if (c->u.a.lensofar < 4) {
5480 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
5481 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
5485 c->u.a.lensofar += l;
5487 if (c->u.a.lensofar == 4) {
5489 4 + GET_32BIT(c->u.a.msglen);
5490 c->u.a.message = snewn(c->u.a.totallen,
5492 memcpy(c->u.a.message, c->u.a.msglen, 4);
5494 if (c->u.a.lensofar >= 4 && len > 0) {
5496 min(c->u.a.totallen - c->u.a.lensofar,
5498 memcpy(c->u.a.message + c->u.a.lensofar, p,
5502 c->u.a.lensofar += l;
5504 if (c->u.a.lensofar == c->u.a.totallen) {
5507 c->u.a.outstanding_requests++;
5508 if (agent_query(c->u.a.message,
5511 ssh_agentf_callback, c))
5512 ssh_agentf_callback(c, reply, replylen);
5513 sfree(c->u.a.message);
5514 c->u.a.lensofar = 0;
5517 bufsize = 0; /* agent channels never back up */
5520 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5521 c->throttling_conn = 1;
5522 ssh_throttle_conn(ssh, +1);
5527 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5529 ssh->exitcode = ssh_pkt_getuint32(pktin);
5530 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5531 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5533 * In case `helpful' firewalls or proxies tack
5534 * extra human-readable text on the end of the
5535 * session which we might mistake for another
5536 * encrypted packet, we close the session once
5537 * we've sent EXIT_CONFIRMATION.
5539 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5542 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5543 static void ssh1_send_ttymode(void *data, char *mode, char *val)
5545 struct Packet *pktout = (struct Packet *)data;
5547 unsigned int arg = 0;
5548 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5549 if (i == lenof(ssh_ttymodes)) return;
5550 switch (ssh_ttymodes[i].type) {
5552 arg = ssh_tty_parse_specchar(val);
5555 arg = ssh_tty_parse_boolean(val);
5558 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5559 ssh2_pkt_addbyte(pktout, arg);
5562 int ssh_agent_forwarding_permitted(Ssh ssh)
5564 return conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists();
5567 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
5568 struct Packet *pktin)
5570 crBegin(ssh->do_ssh1_connection_crstate);
5572 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5573 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5574 ssh1_smsg_stdout_stderr_data;
5576 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5577 ssh1_msg_channel_open_confirmation;
5578 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5579 ssh1_msg_channel_open_failure;
5580 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5581 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5582 ssh1_msg_channel_close;
5583 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5584 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5586 if (ssh_agent_forwarding_permitted(ssh)) {
5587 logevent("Requesting agent forwarding");
5588 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5592 if (pktin->type != SSH1_SMSG_SUCCESS
5593 && pktin->type != SSH1_SMSG_FAILURE) {
5594 bombout(("Protocol confusion"));
5596 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5597 logevent("Agent forwarding refused");
5599 logevent("Agent forwarding enabled");
5600 ssh->agentfwd_enabled = TRUE;
5601 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5605 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
5607 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5609 if (!ssh->x11disp) {
5610 /* FIXME: return an error message from x11_setup_display */
5611 logevent("X11 forwarding not enabled: unable to"
5612 " initialise X display");
5614 ssh->x11auth = x11_invent_fake_auth
5615 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
5616 ssh->x11auth->disp = ssh->x11disp;
5618 logevent("Requesting X11 forwarding");
5619 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5620 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5621 PKT_STR, ssh->x11auth->protoname,
5622 PKT_STR, ssh->x11auth->datastring,
5623 PKT_INT, ssh->x11disp->screennum,
5626 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5627 PKT_STR, ssh->x11auth->protoname,
5628 PKT_STR, ssh->x11auth->datastring,
5634 if (pktin->type != SSH1_SMSG_SUCCESS
5635 && pktin->type != SSH1_SMSG_FAILURE) {
5636 bombout(("Protocol confusion"));
5638 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5639 logevent("X11 forwarding refused");
5641 logevent("X11 forwarding enabled");
5642 ssh->X11_fwd_enabled = TRUE;
5643 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5648 ssh_setup_portfwd(ssh, ssh->conf);
5649 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5651 if (!conf_get_int(ssh->conf, CONF_nopty)) {
5653 /* Unpick the terminal-speed string. */
5654 /* XXX perhaps we should allow no speeds to be sent. */
5655 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5656 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
5657 /* Send the pty request. */
5658 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5659 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
5660 ssh_pkt_adduint32(pkt, ssh->term_height);
5661 ssh_pkt_adduint32(pkt, ssh->term_width);
5662 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5663 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5664 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
5665 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5666 ssh_pkt_adduint32(pkt, ssh->ispeed);
5667 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5668 ssh_pkt_adduint32(pkt, ssh->ospeed);
5669 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5671 ssh->state = SSH_STATE_INTERMED;
5675 if (pktin->type != SSH1_SMSG_SUCCESS
5676 && pktin->type != SSH1_SMSG_FAILURE) {
5677 bombout(("Protocol confusion"));
5679 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5680 c_write_str(ssh, "Server refused to allocate pty\r\n");
5681 ssh->editing = ssh->echoing = 1;
5683 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5684 ssh->ospeed, ssh->ispeed);
5685 ssh->got_pty = TRUE;
5688 ssh->editing = ssh->echoing = 1;
5691 if (conf_get_int(ssh->conf, CONF_compression)) {
5692 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5696 if (pktin->type != SSH1_SMSG_SUCCESS
5697 && pktin->type != SSH1_SMSG_FAILURE) {
5698 bombout(("Protocol confusion"));
5700 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5701 c_write_str(ssh, "Server refused to compress\r\n");
5703 logevent("Started compression");
5704 ssh->v1_compressing = TRUE;
5705 ssh->cs_comp_ctx = zlib_compress_init();
5706 logevent("Initialised zlib (RFC1950) compression");
5707 ssh->sc_comp_ctx = zlib_decompress_init();
5708 logevent("Initialised zlib (RFC1950) decompression");
5712 * Start the shell or command.
5714 * Special case: if the first-choice command is an SSH-2
5715 * subsystem (hence not usable here) and the second choice
5716 * exists, we fall straight back to that.
5719 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
5721 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
5722 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
5723 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
5724 ssh->fallback_cmd = TRUE;
5727 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
5729 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
5730 logevent("Started session");
5733 ssh->state = SSH_STATE_SESSION;
5734 if (ssh->size_needed)
5735 ssh_size(ssh, ssh->term_width, ssh->term_height);
5736 if (ssh->eof_needed)
5737 ssh_special(ssh, TS_EOF);
5740 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5742 ssh->channels = newtree234(ssh_channelcmp);
5746 * By this point, most incoming packets are already being
5747 * handled by the dispatch table, and we need only pay
5748 * attention to the unusual ones.
5753 if (pktin->type == SSH1_SMSG_SUCCESS) {
5754 /* may be from EXEC_SHELL on some servers */
5755 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5756 /* may be from EXEC_SHELL on some servers
5757 * if no pty is available or in other odd cases. Ignore */
5759 bombout(("Strange packet received: type %d", pktin->type));
5764 int len = min(inlen, 512);
5765 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
5766 PKT_INT, len, PKT_DATA, in, len,
5778 * Handle the top-level SSH-2 protocol.
5780 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
5785 ssh_pkt_getstring(pktin, &msg, &msglen);
5786 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
5789 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
5791 /* log reason code in disconnect message */
5795 ssh_pkt_getstring(pktin, &msg, &msglen);
5796 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
5799 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
5801 /* Do nothing, because we're ignoring it! Duhh. */
5804 static void ssh1_protocol_setup(Ssh ssh)
5809 * Most messages are handled by the coroutines.
5811 for (i = 0; i < 256; i++)
5812 ssh->packet_dispatch[i] = NULL;
5815 * These special message types we install handlers for.
5817 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
5818 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
5819 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
5822 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
5823 struct Packet *pktin)
5825 unsigned char *in=(unsigned char*)vin;
5826 if (ssh->state == SSH_STATE_CLOSED)
5829 if (pktin && ssh->packet_dispatch[pktin->type]) {
5830 ssh->packet_dispatch[pktin->type](ssh, pktin);
5834 if (!ssh->protocol_initial_phase_done) {
5835 if (do_ssh1_login(ssh, in, inlen, pktin))
5836 ssh->protocol_initial_phase_done = TRUE;
5841 do_ssh1_connection(ssh, in, inlen, pktin);
5845 * Utility routine for decoding comma-separated strings in KEXINIT.
5847 static int in_commasep_string(char *needle, char *haystack, int haylen)
5850 if (!needle || !haystack) /* protect against null pointers */
5852 needlen = strlen(needle);
5855 * Is it at the start of the string?
5857 if (haylen >= needlen && /* haystack is long enough */
5858 !memcmp(needle, haystack, needlen) && /* initial match */
5859 (haylen == needlen || haystack[needlen] == ',')
5860 /* either , or EOS follows */
5864 * If not, search for the next comma and resume after that.
5865 * If no comma found, terminate.
5867 while (haylen > 0 && *haystack != ',')
5868 haylen--, haystack++;
5871 haylen--, haystack++; /* skip over comma itself */
5876 * Similar routine for checking whether we have the first string in a list.
5878 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
5881 if (!needle || !haystack) /* protect against null pointers */
5883 needlen = strlen(needle);
5885 * Is it at the start of the string?
5887 if (haylen >= needlen && /* haystack is long enough */
5888 !memcmp(needle, haystack, needlen) && /* initial match */
5889 (haylen == needlen || haystack[needlen] == ',')
5890 /* either , or EOS follows */
5898 * SSH-2 key creation method.
5899 * (Currently assumes 2 lots of any hash are sufficient to generate
5900 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
5902 #define SSH2_MKKEY_ITERS (2)
5903 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
5904 unsigned char *keyspace)
5906 const struct ssh_hash *h = ssh->kex->hash;
5908 /* First 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, &chr, 1);
5914 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
5915 h->final(s, keyspace);
5916 /* Next hlen bytes. */
5918 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5919 hash_mpint(h, s, K);
5920 h->bytes(s, H, h->hlen);
5921 h->bytes(s, keyspace, h->hlen);
5922 h->final(s, keyspace + h->hlen);
5926 * Handle the SSH-2 transport layer.
5928 static void do_ssh2_transport(Ssh ssh, void *vin, int inlen,
5929 struct Packet *pktin)
5931 unsigned char *in = (unsigned char *)vin;
5932 struct do_ssh2_transport_state {
5934 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
5935 Bignum p, g, e, f, K;
5938 int kex_init_value, kex_reply_value;
5939 const struct ssh_mac **maclist;
5941 const struct ssh2_cipher *cscipher_tobe;
5942 const struct ssh2_cipher *sccipher_tobe;
5943 const struct ssh_mac *csmac_tobe;
5944 const struct ssh_mac *scmac_tobe;
5945 const struct ssh_compress *cscomp_tobe;
5946 const struct ssh_compress *sccomp_tobe;
5947 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
5948 int hostkeylen, siglen, rsakeylen;
5949 void *hkey; /* actual host key */
5950 void *rsakey; /* for RSA kex */
5951 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
5952 int n_preferred_kex;
5953 const struct ssh_kexes *preferred_kex[KEX_MAX];
5954 int n_preferred_ciphers;
5955 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
5956 const struct ssh_compress *preferred_comp;
5957 int userauth_succeeded; /* for delayed compression */
5958 int pending_compression;
5959 int got_session_id, activated_authconn;
5960 struct Packet *pktout;
5965 crState(do_ssh2_transport_state);
5967 assert(!ssh->bare_connection);
5971 s->cscipher_tobe = s->sccipher_tobe = NULL;
5972 s->csmac_tobe = s->scmac_tobe = NULL;
5973 s->cscomp_tobe = s->sccomp_tobe = NULL;
5975 s->got_session_id = s->activated_authconn = FALSE;
5976 s->userauth_succeeded = FALSE;
5977 s->pending_compression = FALSE;
5980 * Be prepared to work around the buggy MAC problem.
5982 if (ssh->remote_bugs & BUG_SSH2_HMAC)
5983 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
5985 s->maclist = macs, s->nmacs = lenof(macs);
5988 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
5990 int i, j, k, commalist_started;
5993 * Set up the preferred key exchange. (NULL => warn below here)
5995 s->n_preferred_kex = 0;
5996 for (i = 0; i < KEX_MAX; i++) {
5997 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
5999 s->preferred_kex[s->n_preferred_kex++] =
6000 &ssh_diffiehellman_gex;
6003 s->preferred_kex[s->n_preferred_kex++] =
6004 &ssh_diffiehellman_group14;
6007 s->preferred_kex[s->n_preferred_kex++] =
6008 &ssh_diffiehellman_group1;
6011 s->preferred_kex[s->n_preferred_kex++] =
6015 /* Flag for later. Don't bother if it's the last in
6017 if (i < KEX_MAX - 1) {
6018 s->preferred_kex[s->n_preferred_kex++] = NULL;
6025 * Set up the preferred ciphers. (NULL => warn below here)
6027 s->n_preferred_ciphers = 0;
6028 for (i = 0; i < CIPHER_MAX; i++) {
6029 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
6030 case CIPHER_BLOWFISH:
6031 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
6034 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
6035 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
6039 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
6042 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
6044 case CIPHER_ARCFOUR:
6045 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
6048 /* Flag for later. Don't bother if it's the last in
6050 if (i < CIPHER_MAX - 1) {
6051 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
6058 * Set up preferred compression.
6060 if (conf_get_int(ssh->conf, CONF_compression))
6061 s->preferred_comp = &ssh_zlib;
6063 s->preferred_comp = &ssh_comp_none;
6066 * Enable queueing of outgoing auth- or connection-layer
6067 * packets while we are in the middle of a key exchange.
6069 ssh->queueing = TRUE;
6072 * Flag that KEX is in progress.
6074 ssh->kex_in_progress = TRUE;
6077 * Construct and send our key exchange packet.
6079 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
6080 for (i = 0; i < 16; i++)
6081 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
6082 /* List key exchange algorithms. */
6083 ssh2_pkt_addstring_start(s->pktout);
6084 commalist_started = 0;
6085 for (i = 0; i < s->n_preferred_kex; i++) {
6086 const struct ssh_kexes *k = s->preferred_kex[i];
6087 if (!k) continue; /* warning flag */
6088 for (j = 0; j < k->nkexes; j++) {
6089 if (commalist_started)
6090 ssh2_pkt_addstring_str(s->pktout, ",");
6091 ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
6092 commalist_started = 1;
6095 /* List server host key algorithms. */
6096 if (!s->got_session_id) {
6098 * In the first key exchange, we list all the algorithms
6099 * we're prepared to cope with.
6101 ssh2_pkt_addstring_start(s->pktout);
6102 for (i = 0; i < lenof(hostkey_algs); i++) {
6103 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
6104 if (i < lenof(hostkey_algs) - 1)
6105 ssh2_pkt_addstring_str(s->pktout, ",");
6109 * In subsequent key exchanges, we list only the kex
6110 * algorithm that was selected in the first key exchange,
6111 * so that we keep getting the same host key and hence
6112 * don't have to interrupt the user's session to ask for
6116 ssh2_pkt_addstring(s->pktout, ssh->hostkey->name);
6118 /* List encryption algorithms (client->server then server->client). */
6119 for (k = 0; k < 2; k++) {
6120 ssh2_pkt_addstring_start(s->pktout);
6121 commalist_started = 0;
6122 for (i = 0; i < s->n_preferred_ciphers; i++) {
6123 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6124 if (!c) continue; /* warning flag */
6125 for (j = 0; j < c->nciphers; j++) {
6126 if (commalist_started)
6127 ssh2_pkt_addstring_str(s->pktout, ",");
6128 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
6129 commalist_started = 1;
6133 /* List MAC algorithms (client->server then server->client). */
6134 for (j = 0; j < 2; j++) {
6135 ssh2_pkt_addstring_start(s->pktout);
6136 for (i = 0; i < s->nmacs; i++) {
6137 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
6138 if (i < s->nmacs - 1)
6139 ssh2_pkt_addstring_str(s->pktout, ",");
6142 /* List client->server compression algorithms,
6143 * then server->client compression algorithms. (We use the
6144 * same set twice.) */
6145 for (j = 0; j < 2; j++) {
6146 ssh2_pkt_addstring_start(s->pktout);
6147 assert(lenof(compressions) > 1);
6148 /* Prefer non-delayed versions */
6149 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
6150 /* We don't even list delayed versions of algorithms until
6151 * they're allowed to be used, to avoid a race. See the end of
6153 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
6154 ssh2_pkt_addstring_str(s->pktout, ",");
6155 ssh2_pkt_addstring_str(s->pktout,
6156 s->preferred_comp->delayed_name);
6158 for (i = 0; i < lenof(compressions); i++) {
6159 const struct ssh_compress *c = compressions[i];
6160 if (c != s->preferred_comp) {
6161 ssh2_pkt_addstring_str(s->pktout, ",");
6162 ssh2_pkt_addstring_str(s->pktout, c->name);
6163 if (s->userauth_succeeded && c->delayed_name) {
6164 ssh2_pkt_addstring_str(s->pktout, ",");
6165 ssh2_pkt_addstring_str(s->pktout, c->delayed_name);
6170 /* List client->server languages. Empty list. */
6171 ssh2_pkt_addstring_start(s->pktout);
6172 /* List server->client languages. Empty list. */
6173 ssh2_pkt_addstring_start(s->pktout);
6174 /* First KEX packet does _not_ follow, because we're not that brave. */
6175 ssh2_pkt_addbool(s->pktout, FALSE);
6177 ssh2_pkt_adduint32(s->pktout, 0);
6180 s->our_kexinitlen = s->pktout->length - 5;
6181 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
6182 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
6184 ssh2_pkt_send_noqueue(ssh, s->pktout);
6187 crWaitUntilV(pktin);
6190 * Now examine the other side's KEXINIT to see what we're up
6194 char *str, *preferred;
6197 if (pktin->type != SSH2_MSG_KEXINIT) {
6198 bombout(("expected key exchange packet from server"));
6202 ssh->hostkey = NULL;
6203 s->cscipher_tobe = NULL;
6204 s->sccipher_tobe = NULL;
6205 s->csmac_tobe = NULL;
6206 s->scmac_tobe = NULL;
6207 s->cscomp_tobe = NULL;
6208 s->sccomp_tobe = NULL;
6209 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
6211 pktin->savedpos += 16; /* skip garbage cookie */
6212 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
6215 for (i = 0; i < s->n_preferred_kex; i++) {
6216 const struct ssh_kexes *k = s->preferred_kex[i];
6220 for (j = 0; j < k->nkexes; j++) {
6221 if (!preferred) preferred = k->list[j]->name;
6222 if (in_commasep_string(k->list[j]->name, str, len)) {
6223 ssh->kex = k->list[j];
6232 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
6233 str ? str : "(null)"));
6237 * Note that the server's guess is considered wrong if it doesn't match
6238 * the first algorithm in our list, even if it's still the algorithm
6241 s->guessok = first_in_commasep_string(preferred, str, len);
6242 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
6243 for (i = 0; i < lenof(hostkey_algs); i++) {
6244 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
6245 ssh->hostkey = hostkey_algs[i];
6249 if (!ssh->hostkey) {
6250 bombout(("Couldn't agree a host key algorithm (available: %s)",
6251 str ? str : "(null)"));
6255 s->guessok = s->guessok &&
6256 first_in_commasep_string(hostkey_algs[0]->name, str, len);
6257 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
6258 for (i = 0; i < s->n_preferred_ciphers; i++) {
6259 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6261 s->warn_cscipher = TRUE;
6263 for (j = 0; j < c->nciphers; j++) {
6264 if (in_commasep_string(c->list[j]->name, str, len)) {
6265 s->cscipher_tobe = c->list[j];
6270 if (s->cscipher_tobe)
6273 if (!s->cscipher_tobe) {
6274 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
6275 str ? str : "(null)"));
6279 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
6280 for (i = 0; i < s->n_preferred_ciphers; i++) {
6281 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6283 s->warn_sccipher = TRUE;
6285 for (j = 0; j < c->nciphers; j++) {
6286 if (in_commasep_string(c->list[j]->name, str, len)) {
6287 s->sccipher_tobe = c->list[j];
6292 if (s->sccipher_tobe)
6295 if (!s->sccipher_tobe) {
6296 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
6297 str ? str : "(null)"));
6301 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
6302 for (i = 0; i < s->nmacs; i++) {
6303 if (in_commasep_string(s->maclist[i]->name, str, len)) {
6304 s->csmac_tobe = s->maclist[i];
6308 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
6309 for (i = 0; i < s->nmacs; i++) {
6310 if (in_commasep_string(s->maclist[i]->name, str, len)) {
6311 s->scmac_tobe = s->maclist[i];
6315 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
6316 for (i = 0; i < lenof(compressions) + 1; i++) {
6317 const struct ssh_compress *c =
6318 i == 0 ? s->preferred_comp : compressions[i - 1];
6319 if (in_commasep_string(c->name, str, len)) {
6322 } else if (in_commasep_string(c->delayed_name, str, len)) {
6323 if (s->userauth_succeeded) {
6327 s->pending_compression = TRUE; /* try this later */
6331 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
6332 for (i = 0; i < lenof(compressions) + 1; i++) {
6333 const struct ssh_compress *c =
6334 i == 0 ? s->preferred_comp : compressions[i - 1];
6335 if (in_commasep_string(c->name, str, len)) {
6338 } else if (in_commasep_string(c->delayed_name, str, len)) {
6339 if (s->userauth_succeeded) {
6343 s->pending_compression = TRUE; /* try this later */
6347 if (s->pending_compression) {
6348 logevent("Server supports delayed compression; "
6349 "will try this later");
6351 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
6352 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
6353 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
6355 ssh->exhash = ssh->kex->hash->init();
6356 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
6357 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
6358 hash_string(ssh->kex->hash, ssh->exhash,
6359 s->our_kexinit, s->our_kexinitlen);
6360 sfree(s->our_kexinit);
6361 /* Include the type byte in the hash of server's KEXINIT */
6362 hash_string(ssh->kex->hash, ssh->exhash,
6363 pktin->body - 1, pktin->length + 1);
6366 ssh_set_frozen(ssh, 1);
6367 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
6369 ssh_dialog_callback, ssh);
6370 if (s->dlgret < 0) {
6374 bombout(("Unexpected data from server while"
6375 " waiting for user response"));
6378 } while (pktin || inlen > 0);
6379 s->dlgret = ssh->user_response;
6381 ssh_set_frozen(ssh, 0);
6382 if (s->dlgret == 0) {
6383 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
6389 if (s->warn_cscipher) {
6390 ssh_set_frozen(ssh, 1);
6391 s->dlgret = askalg(ssh->frontend,
6392 "client-to-server cipher",
6393 s->cscipher_tobe->name,
6394 ssh_dialog_callback, ssh);
6395 if (s->dlgret < 0) {
6399 bombout(("Unexpected data from server while"
6400 " waiting for user response"));
6403 } while (pktin || inlen > 0);
6404 s->dlgret = ssh->user_response;
6406 ssh_set_frozen(ssh, 0);
6407 if (s->dlgret == 0) {
6408 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6414 if (s->warn_sccipher) {
6415 ssh_set_frozen(ssh, 1);
6416 s->dlgret = askalg(ssh->frontend,
6417 "server-to-client cipher",
6418 s->sccipher_tobe->name,
6419 ssh_dialog_callback, ssh);
6420 if (s->dlgret < 0) {
6424 bombout(("Unexpected data from server while"
6425 " waiting for user response"));
6428 } while (pktin || inlen > 0);
6429 s->dlgret = ssh->user_response;
6431 ssh_set_frozen(ssh, 0);
6432 if (s->dlgret == 0) {
6433 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6439 if (s->ignorepkt) /* first_kex_packet_follows */
6440 crWaitUntilV(pktin); /* Ignore packet */
6443 if (ssh->kex->main_type == KEXTYPE_DH) {
6445 * Work out the number of bits of key we will need from the
6446 * key exchange. We start with the maximum key length of
6452 csbits = s->cscipher_tobe->keylen;
6453 scbits = s->sccipher_tobe->keylen;
6454 s->nbits = (csbits > scbits ? csbits : scbits);
6456 /* The keys only have hlen-bit entropy, since they're based on
6457 * a hash. So cap the key size at hlen bits. */
6458 if (s->nbits > ssh->kex->hash->hlen * 8)
6459 s->nbits = ssh->kex->hash->hlen * 8;
6462 * If we're doing Diffie-Hellman group exchange, start by
6463 * requesting a group.
6465 if (!ssh->kex->pdata) {
6466 logevent("Doing Diffie-Hellman group exchange");
6467 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
6469 * Work out how big a DH group we will need to allow that
6472 s->pbits = 512 << ((s->nbits - 1) / 64);
6473 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6474 ssh2_pkt_adduint32(s->pktout, s->pbits);
6475 ssh2_pkt_send_noqueue(ssh, s->pktout);
6477 crWaitUntilV(pktin);
6478 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6479 bombout(("expected key exchange group packet from server"));
6482 s->p = ssh2_pkt_getmp(pktin);
6483 s->g = ssh2_pkt_getmp(pktin);
6484 if (!s->p || !s->g) {
6485 bombout(("unable to read mp-ints from incoming group packet"));
6488 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6489 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6490 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6492 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
6493 ssh->kex_ctx = dh_setup_group(ssh->kex);
6494 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6495 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6496 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6497 ssh->kex->groupname);
6500 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6501 ssh->kex->hash->text_name);
6503 * Now generate and send e for Diffie-Hellman.
6505 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6506 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6507 s->pktout = ssh2_pkt_init(s->kex_init_value);
6508 ssh2_pkt_addmp(s->pktout, s->e);
6509 ssh2_pkt_send_noqueue(ssh, s->pktout);
6511 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
6512 crWaitUntilV(pktin);
6513 if (pktin->type != s->kex_reply_value) {
6514 bombout(("expected key exchange reply packet from server"));
6517 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
6518 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6519 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6520 s->f = ssh2_pkt_getmp(pktin);
6522 bombout(("unable to parse key exchange reply packet"));
6525 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6527 s->K = dh_find_K(ssh->kex_ctx, s->f);
6529 /* We assume everything from now on will be quick, and it might
6530 * involve user interaction. */
6531 set_busy_status(ssh->frontend, BUSY_NOT);
6533 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6534 if (!ssh->kex->pdata) {
6535 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
6536 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
6537 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
6539 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
6540 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
6542 dh_cleanup(ssh->kex_ctx);
6544 if (!ssh->kex->pdata) {
6549 logeventf(ssh, "Doing RSA key exchange with hash %s",
6550 ssh->kex->hash->text_name);
6551 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
6553 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6556 crWaitUntilV(pktin);
6557 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
6558 bombout(("expected RSA public key packet from server"));
6562 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6563 hash_string(ssh->kex->hash, ssh->exhash,
6564 s->hostkeydata, s->hostkeylen);
6565 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6569 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
6570 s->rsakeydata = snewn(s->rsakeylen, char);
6571 memcpy(s->rsakeydata, keydata, s->rsakeylen);
6574 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
6576 sfree(s->rsakeydata);
6577 bombout(("unable to parse RSA public key from server"));
6581 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
6584 * Next, set up a shared secret K, of precisely KLEN -
6585 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6586 * RSA key modulus and HLEN is the bit length of the hash
6590 int klen = ssh_rsakex_klen(s->rsakey);
6591 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
6593 unsigned char *kstr1, *kstr2, *outstr;
6594 int kstr1len, kstr2len, outstrlen;
6596 s->K = bn_power_2(nbits - 1);
6598 for (i = 0; i < nbits; i++) {
6600 byte = random_byte();
6602 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
6606 * Encode this as an mpint.
6608 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
6609 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
6610 PUT_32BIT(kstr2, kstr1len);
6611 memcpy(kstr2 + 4, kstr1, kstr1len);
6614 * Encrypt it with the given RSA key.
6616 outstrlen = (klen + 7) / 8;
6617 outstr = snewn(outstrlen, unsigned char);
6618 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
6619 outstr, outstrlen, s->rsakey);
6622 * And send it off in a return packet.
6624 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
6625 ssh2_pkt_addstring_start(s->pktout);
6626 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
6627 ssh2_pkt_send_noqueue(ssh, s->pktout);
6629 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
6636 ssh_rsakex_freekey(s->rsakey);
6638 crWaitUntilV(pktin);
6639 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
6640 sfree(s->rsakeydata);
6641 bombout(("expected signature packet from server"));
6645 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6647 sfree(s->rsakeydata);
6650 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
6651 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
6652 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
6654 ssh->kex_ctx = NULL;
6657 debug(("Exchange hash is:\n"));
6658 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
6662 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
6663 (char *)s->exchange_hash,
6664 ssh->kex->hash->hlen)) {
6665 bombout(("Server's host key did not match the signature supplied"));
6669 s->keystr = ssh->hostkey->fmtkey(s->hkey);
6670 if (!s->got_session_id) {
6672 * Authenticate remote host: verify host key. (We've already
6673 * checked the signature of the exchange hash.)
6675 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
6676 ssh_set_frozen(ssh, 1);
6677 s->dlgret = verify_ssh_host_key(ssh->frontend,
6678 ssh->savedhost, ssh->savedport,
6679 ssh->hostkey->keytype, s->keystr,
6681 ssh_dialog_callback, ssh);
6682 if (s->dlgret < 0) {
6686 bombout(("Unexpected data from server while waiting"
6687 " for user host key response"));
6690 } while (pktin || inlen > 0);
6691 s->dlgret = ssh->user_response;
6693 ssh_set_frozen(ssh, 0);
6694 if (s->dlgret == 0) {
6695 ssh_disconnect(ssh, "User aborted at host key verification", NULL,
6699 logevent("Host key fingerprint is:");
6700 logevent(s->fingerprint);
6701 sfree(s->fingerprint);
6703 * Save this host key, to check against the one presented in
6704 * subsequent rekeys.
6706 ssh->hostkey_str = s->keystr;
6709 * In a rekey, we never present an interactive host key
6710 * verification request to the user. Instead, we simply
6711 * enforce that the key we're seeing this time is identical to
6712 * the one we saw before.
6714 if (strcmp(ssh->hostkey_str, s->keystr)) {
6715 bombout(("Host key was different in repeat key exchange"));
6720 ssh->hostkey->freekey(s->hkey);
6723 * The exchange hash from the very first key exchange is also
6724 * the session id, used in session key construction and
6727 if (!s->got_session_id) {
6728 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
6729 memcpy(ssh->v2_session_id, s->exchange_hash,
6730 sizeof(s->exchange_hash));
6731 ssh->v2_session_id_len = ssh->kex->hash->hlen;
6732 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
6733 s->got_session_id = TRUE;
6737 * Send SSH2_MSG_NEWKEYS.
6739 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
6740 ssh2_pkt_send_noqueue(ssh, s->pktout);
6741 ssh->outgoing_data_size = 0; /* start counting from here */
6744 * We've sent client NEWKEYS, so create and initialise
6745 * client-to-server session keys.
6747 if (ssh->cs_cipher_ctx)
6748 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6749 ssh->cscipher = s->cscipher_tobe;
6750 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
6752 if (ssh->cs_mac_ctx)
6753 ssh->csmac->free_context(ssh->cs_mac_ctx);
6754 ssh->csmac = s->csmac_tobe;
6755 ssh->cs_mac_ctx = ssh->csmac->make_context();
6757 if (ssh->cs_comp_ctx)
6758 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6759 ssh->cscomp = s->cscomp_tobe;
6760 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
6763 * Set IVs on client-to-server keys. Here we use the exchange
6764 * hash from the _first_ key exchange.
6767 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6768 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6769 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
6770 assert((ssh->cscipher->keylen+7) / 8 <=
6771 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6772 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
6773 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
6774 assert(ssh->cscipher->blksize <=
6775 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6776 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
6777 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
6778 assert(ssh->csmac->len <=
6779 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6780 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
6781 smemclr(keyspace, sizeof(keyspace));
6784 logeventf(ssh, "Initialised %.200s client->server encryption",
6785 ssh->cscipher->text_name);
6786 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
6787 ssh->csmac->text_name);
6788 if (ssh->cscomp->text_name)
6789 logeventf(ssh, "Initialised %s compression",
6790 ssh->cscomp->text_name);
6793 * Now our end of the key exchange is complete, we can send all
6794 * our queued higher-layer packets.
6796 ssh->queueing = FALSE;
6797 ssh2_pkt_queuesend(ssh);
6800 * Expect SSH2_MSG_NEWKEYS from server.
6802 crWaitUntilV(pktin);
6803 if (pktin->type != SSH2_MSG_NEWKEYS) {
6804 bombout(("expected new-keys packet from server"));
6807 ssh->incoming_data_size = 0; /* start counting from here */
6810 * We've seen server NEWKEYS, so create and initialise
6811 * server-to-client session keys.
6813 if (ssh->sc_cipher_ctx)
6814 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6815 ssh->sccipher = s->sccipher_tobe;
6816 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
6818 if (ssh->sc_mac_ctx)
6819 ssh->scmac->free_context(ssh->sc_mac_ctx);
6820 ssh->scmac = s->scmac_tobe;
6821 ssh->sc_mac_ctx = ssh->scmac->make_context();
6823 if (ssh->sc_comp_ctx)
6824 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
6825 ssh->sccomp = s->sccomp_tobe;
6826 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
6829 * Set IVs on server-to-client keys. Here we use the exchange
6830 * hash from the _first_ key exchange.
6833 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6834 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6835 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
6836 assert((ssh->sccipher->keylen+7) / 8 <=
6837 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6838 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
6839 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
6840 assert(ssh->sccipher->blksize <=
6841 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6842 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
6843 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
6844 assert(ssh->scmac->len <=
6845 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6846 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
6847 smemclr(keyspace, sizeof(keyspace));
6849 logeventf(ssh, "Initialised %.200s server->client encryption",
6850 ssh->sccipher->text_name);
6851 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
6852 ssh->scmac->text_name);
6853 if (ssh->sccomp->text_name)
6854 logeventf(ssh, "Initialised %s decompression",
6855 ssh->sccomp->text_name);
6858 * Free shared secret.
6863 * Key exchange is over. Loop straight back round if we have a
6864 * deferred rekey reason.
6866 if (ssh->deferred_rekey_reason) {
6867 logevent(ssh->deferred_rekey_reason);
6869 ssh->deferred_rekey_reason = NULL;
6870 goto begin_key_exchange;
6874 * Otherwise, schedule a timer for our next rekey.
6876 ssh->kex_in_progress = FALSE;
6877 ssh->last_rekey = GETTICKCOUNT();
6878 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
6879 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
6883 * Now we're encrypting. Begin returning 1 to the protocol main
6884 * function so that other things can run on top of the
6885 * transport. If we ever see a KEXINIT, we must go back to the
6888 * We _also_ go back to the start if we see pktin==NULL and
6889 * inlen negative, because this is a special signal meaning
6890 * `initiate client-driven rekey', and `in' contains a message
6891 * giving the reason for the rekey.
6893 * inlen==-1 means always initiate a rekey;
6894 * inlen==-2 means that userauth has completed successfully and
6895 * we should consider rekeying (for delayed compression).
6897 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
6898 (!pktin && inlen < 0))) {
6900 if (!ssh->protocol_initial_phase_done) {
6901 ssh->protocol_initial_phase_done = TRUE;
6903 * Allow authconn to initialise itself.
6905 do_ssh2_authconn(ssh, NULL, 0, NULL);
6910 logevent("Server initiated key re-exchange");
6914 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
6915 * delayed compression, if it's available.
6917 * draft-miller-secsh-compression-delayed-00 says that you
6918 * negotiate delayed compression in the first key exchange, and
6919 * both sides start compressing when the server has sent
6920 * USERAUTH_SUCCESS. This has a race condition -- the server
6921 * can't know when the client has seen it, and thus which incoming
6922 * packets it should treat as compressed.
6924 * Instead, we do the initial key exchange without offering the
6925 * delayed methods, but note if the server offers them; when we
6926 * get here, if a delayed method was available that was higher
6927 * on our list than what we got, we initiate a rekey in which we
6928 * _do_ list the delayed methods (and hopefully get it as a
6929 * result). Subsequent rekeys will do the same.
6931 assert(!s->userauth_succeeded); /* should only happen once */
6932 s->userauth_succeeded = TRUE;
6933 if (!s->pending_compression)
6934 /* Can't see any point rekeying. */
6935 goto wait_for_rekey; /* this is utterly horrid */
6936 /* else fall through to rekey... */
6937 s->pending_compression = FALSE;
6940 * Now we've decided to rekey.
6942 * Special case: if the server bug is set that doesn't
6943 * allow rekeying, we give a different log message and
6944 * continue waiting. (If such a server _initiates_ a rekey,
6945 * we process it anyway!)
6947 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
6948 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
6950 /* Reset the counters, so that at least this message doesn't
6951 * hit the event log _too_ often. */
6952 ssh->outgoing_data_size = 0;
6953 ssh->incoming_data_size = 0;
6954 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
6956 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
6959 goto wait_for_rekey; /* this is still utterly horrid */
6961 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
6964 goto begin_key_exchange;
6970 * Add data to an SSH-2 channel output buffer.
6972 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
6975 bufchain_add(&c->v.v2.outbuffer, buf, len);
6979 * Attempt to send data on an SSH-2 channel.
6981 static int ssh2_try_send(struct ssh_channel *c)
6984 struct Packet *pktout;
6987 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
6990 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
6991 if ((unsigned)len > c->v.v2.remwindow)
6992 len = c->v.v2.remwindow;
6993 if ((unsigned)len > c->v.v2.remmaxpkt)
6994 len = c->v.v2.remmaxpkt;
6995 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
6996 ssh2_pkt_adduint32(pktout, c->remoteid);
6997 ssh2_pkt_addstring_start(pktout);
6998 ssh2_pkt_addstring_data(pktout, data, len);
6999 ssh2_pkt_send(ssh, pktout);
7000 bufchain_consume(&c->v.v2.outbuffer, len);
7001 c->v.v2.remwindow -= len;
7005 * After having sent as much data as we can, return the amount
7008 ret = bufchain_size(&c->v.v2.outbuffer);
7011 * And if there's no data pending but we need to send an EOF, send
7014 if (!ret && c->pending_eof)
7015 ssh_channel_try_eof(c);
7020 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
7023 if (c->closes & CLOSES_SENT_EOF)
7024 return; /* don't send on channels we've EOFed */
7025 bufsize = ssh2_try_send(c);
7028 case CHAN_MAINSESSION:
7029 /* stdin need not receive an unthrottle
7030 * notification since it will be polled */
7033 x11_unthrottle(c->u.x11.xconn);
7036 /* agent sockets are request/response and need no
7037 * buffer management */
7040 pfd_unthrottle(c->u.pfd.pf);
7046 static int ssh_is_simple(Ssh ssh)
7049 * We use the 'simple' variant of the SSH protocol if we're asked
7050 * to, except not if we're also doing connection-sharing (either
7051 * tunnelling our packets over an upstream or expecting to be
7052 * tunnelled over ourselves), since then the assumption that we
7053 * have only one channel to worry about is not true after all.
7055 return (conf_get_int(ssh->conf, CONF_ssh_simple) &&
7056 !ssh->bare_connection && !ssh->connshare);
7060 * Set up most of a new ssh_channel for SSH-2.
7062 static void ssh2_channel_init(struct ssh_channel *c)
7065 c->localid = alloc_channel_id(ssh);
7067 c->pending_eof = FALSE;
7068 c->throttling_conn = FALSE;
7069 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
7070 ssh_is_simple(ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
7071 c->v.v2.chanreq_head = NULL;
7072 c->v.v2.throttle_state = UNTHROTTLED;
7073 bufchain_init(&c->v.v2.outbuffer);
7077 * Construct the common parts of a CHANNEL_OPEN.
7079 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c, char *type)
7081 struct Packet *pktout;
7083 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7084 ssh2_pkt_addstring(pktout, type);
7085 ssh2_pkt_adduint32(pktout, c->localid);
7086 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7087 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7092 * CHANNEL_FAILURE doesn't come with any indication of what message
7093 * caused it, so we have to keep track of the outstanding
7094 * CHANNEL_REQUESTs ourselves.
7096 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
7097 cchandler_fn_t handler, void *ctx)
7099 struct outstanding_channel_request *ocr =
7100 snew(struct outstanding_channel_request);
7102 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7103 ocr->handler = handler;
7106 if (!c->v.v2.chanreq_head)
7107 c->v.v2.chanreq_head = ocr;
7109 c->v.v2.chanreq_tail->next = ocr;
7110 c->v.v2.chanreq_tail = ocr;
7114 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
7115 * NULL then a reply will be requested and the handler will be called
7116 * when it arrives. The returned packet is ready to have any
7117 * request-specific data added and be sent. Note that if a handler is
7118 * provided, it's essential that the request actually be sent.
7120 * The handler will usually be passed the response packet in pktin.
7121 * If pktin is NULL, this means that no reply will ever be forthcoming
7122 * (e.g. because the entire connection is being destroyed) and the
7123 * handler should free any storage it's holding.
7125 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c, char *type,
7126 cchandler_fn_t handler, void *ctx)
7128 struct Packet *pktout;
7130 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7131 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7132 ssh2_pkt_adduint32(pktout, c->remoteid);
7133 ssh2_pkt_addstring(pktout, type);
7134 ssh2_pkt_addbool(pktout, handler != NULL);
7135 if (handler != NULL)
7136 ssh2_queue_chanreq_handler(c, handler, ctx);
7141 * Potentially enlarge the window on an SSH-2 channel.
7143 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
7145 static void ssh2_set_window(struct ssh_channel *c, int newwin)
7150 * Never send WINDOW_ADJUST for a channel that the remote side has
7151 * already sent EOF on; there's no point, since it won't be
7152 * sending any more data anyway. Ditto if _we've_ already sent
7155 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
7159 * Also, never widen the window for an X11 channel when we're
7160 * still waiting to see its initial auth and may yet hand it off
7163 if (c->type == CHAN_X11 && c->u.x11.initial)
7167 * If the remote end has a habit of ignoring maxpkt, limit the
7168 * window so that it has no choice (assuming it doesn't ignore the
7171 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
7172 newwin = OUR_V2_MAXPKT;
7175 * Only send a WINDOW_ADJUST if there's significantly more window
7176 * available than the other end thinks there is. This saves us
7177 * sending a WINDOW_ADJUST for every character in a shell session.
7179 * "Significant" is arbitrarily defined as half the window size.
7181 if (newwin / 2 >= c->v.v2.locwindow) {
7182 struct Packet *pktout;
7186 * In order to keep track of how much window the client
7187 * actually has available, we'd like it to acknowledge each
7188 * WINDOW_ADJUST. We can't do that directly, so we accompany
7189 * it with a CHANNEL_REQUEST that has to be acknowledged.
7191 * This is only necessary if we're opening the window wide.
7192 * If we're not, then throughput is being constrained by
7193 * something other than the maximum window size anyway.
7195 if (newwin == c->v.v2.locmaxwin &&
7196 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
7197 up = snew(unsigned);
7198 *up = newwin - c->v.v2.locwindow;
7199 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
7200 ssh2_handle_winadj_response, up);
7201 ssh2_pkt_send(ssh, pktout);
7203 if (c->v.v2.throttle_state != UNTHROTTLED)
7204 c->v.v2.throttle_state = UNTHROTTLING;
7206 /* Pretend the WINDOW_ADJUST was acked immediately. */
7207 c->v.v2.remlocwin = newwin;
7208 c->v.v2.throttle_state = THROTTLED;
7210 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7211 ssh2_pkt_adduint32(pktout, c->remoteid);
7212 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
7213 ssh2_pkt_send(ssh, pktout);
7214 c->v.v2.locwindow = newwin;
7219 * Find the channel associated with a message. If there's no channel,
7220 * or it's not properly open, make a noise about it and return NULL.
7222 static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
7224 unsigned localid = ssh_pkt_getuint32(pktin);
7225 struct ssh_channel *c;
7227 c = find234(ssh->channels, &localid, ssh_channelfind);
7229 (c->type != CHAN_SHARING && c->halfopen &&
7230 pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
7231 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
7232 char *buf = dupprintf("Received %s for %s channel %u",
7233 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
7235 c ? "half-open" : "nonexistent", localid);
7236 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
7243 static void ssh2_handle_winadj_response(struct ssh_channel *c,
7244 struct Packet *pktin, void *ctx)
7246 unsigned *sizep = ctx;
7249 * Winadj responses should always be failures. However, at least
7250 * one server ("boks_sshd") is known to return SUCCESS for channel
7251 * requests it's never heard of, such as "winadj@putty". Raised
7252 * with foxt.com as bug 090916-090424, but for the sake of a quiet
7253 * life, we don't worry about what kind of response we got.
7256 c->v.v2.remlocwin += *sizep;
7259 * winadj messages are only sent when the window is fully open, so
7260 * if we get an ack of one, we know any pending unthrottle is
7263 if (c->v.v2.throttle_state == UNTHROTTLING)
7264 c->v.v2.throttle_state = UNTHROTTLED;
7267 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
7269 struct ssh_channel *c = ssh2_channel_msg(ssh, pktin);
7270 struct outstanding_channel_request *ocr;
7273 if (c->type == CHAN_SHARING) {
7274 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7275 pktin->body, pktin->length);
7278 ocr = c->v.v2.chanreq_head;
7280 ssh2_msg_unexpected(ssh, pktin);
7283 ocr->handler(c, pktin, ocr->ctx);
7284 c->v.v2.chanreq_head = ocr->next;
7287 * We may now initiate channel-closing procedures, if that
7288 * CHANNEL_REQUEST was the last thing outstanding before we send
7291 ssh2_channel_check_close(c);
7294 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
7296 struct ssh_channel *c;
7297 c = ssh2_channel_msg(ssh, pktin);
7300 if (c->type == CHAN_SHARING) {
7301 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7302 pktin->body, pktin->length);
7305 if (!(c->closes & CLOSES_SENT_EOF)) {
7306 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
7307 ssh2_try_send_and_unthrottle(ssh, c);
7311 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
7315 struct ssh_channel *c;
7316 c = ssh2_channel_msg(ssh, pktin);
7319 if (c->type == CHAN_SHARING) {
7320 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7321 pktin->body, pktin->length);
7324 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
7325 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
7326 return; /* extended but not stderr */
7327 ssh_pkt_getstring(pktin, &data, &length);
7330 c->v.v2.locwindow -= length;
7331 c->v.v2.remlocwin -= length;
7333 case CHAN_MAINSESSION:
7335 from_backend(ssh->frontend, pktin->type ==
7336 SSH2_MSG_CHANNEL_EXTENDED_DATA,
7340 bufsize = x11_send(c->u.x11.xconn, data, length);
7343 bufsize = pfd_send(c->u.pfd.pf, data, length);
7346 while (length > 0) {
7347 if (c->u.a.lensofar < 4) {
7348 unsigned int l = min(4 - c->u.a.lensofar,
7350 memcpy(c->u.a.msglen + c->u.a.lensofar,
7354 c->u.a.lensofar += l;
7356 if (c->u.a.lensofar == 4) {
7358 4 + GET_32BIT(c->u.a.msglen);
7359 c->u.a.message = snewn(c->u.a.totallen,
7361 memcpy(c->u.a.message, c->u.a.msglen, 4);
7363 if (c->u.a.lensofar >= 4 && length > 0) {
7365 min(c->u.a.totallen - c->u.a.lensofar,
7367 memcpy(c->u.a.message + c->u.a.lensofar,
7371 c->u.a.lensofar += l;
7373 if (c->u.a.lensofar == c->u.a.totallen) {
7376 c->u.a.outstanding_requests++;
7377 if (agent_query(c->u.a.message,
7380 ssh_agentf_callback, c))
7381 ssh_agentf_callback(c, reply, replylen);
7382 sfree(c->u.a.message);
7383 c->u.a.message = NULL;
7384 c->u.a.lensofar = 0;
7391 * If it looks like the remote end hit the end of its window,
7392 * and we didn't want it to do that, think about using a
7395 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
7396 c->v.v2.locmaxwin < 0x40000000)
7397 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
7399 * If we are not buffering too much data,
7400 * enlarge the window again at the remote side.
7401 * If we are buffering too much, we may still
7402 * need to adjust the window if the server's
7405 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
7406 c->v.v2.locmaxwin - bufsize : 0);
7408 * If we're either buffering way too much data, or if we're
7409 * buffering anything at all and we're in "simple" mode,
7410 * throttle the whole channel.
7412 if ((bufsize > c->v.v2.locmaxwin || (ssh_is_simple(ssh) && bufsize>0))
7413 && !c->throttling_conn) {
7414 c->throttling_conn = 1;
7415 ssh_throttle_conn(ssh, +1);
7420 static void ssh_check_termination(Ssh ssh)
7422 if (ssh->version == 2 &&
7423 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
7424 count234(ssh->channels) == 0 &&
7425 !(ssh->connshare && share_ndownstreams(ssh->connshare) > 0)) {
7427 * We used to send SSH_MSG_DISCONNECT here, because I'd
7428 * believed that _every_ conforming SSH-2 connection had to
7429 * end with a disconnect being sent by at least one side;
7430 * apparently I was wrong and it's perfectly OK to
7431 * unceremoniously slam the connection shut when you're done,
7432 * and indeed OpenSSH feels this is more polite than sending a
7433 * DISCONNECT. So now we don't.
7435 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
7439 void ssh_sharing_downstream_connected(Ssh ssh, unsigned id)
7441 logeventf(ssh, "Connection sharing downstream #%u connected", id);
7444 void ssh_sharing_downstream_disconnected(Ssh ssh, unsigned id)
7446 logeventf(ssh, "Connection sharing downstream #%u disconnected", id);
7447 ssh_check_termination(ssh);
7450 void ssh_sharing_logf(Ssh ssh, unsigned id, const char *logfmt, ...)
7455 va_start(ap, logfmt);
7456 buf = dupvprintf(logfmt, ap);
7459 logeventf(ssh, "Connection sharing downstream #%u: %s", id, buf);
7461 logeventf(ssh, "Connection sharing: %s", buf);
7465 static void ssh_channel_destroy(struct ssh_channel *c)
7470 case CHAN_MAINSESSION:
7471 ssh->mainchan = NULL;
7472 update_specials_menu(ssh->frontend);
7475 if (c->u.x11.xconn != NULL)
7476 x11_close(c->u.x11.xconn);
7477 logevent("Forwarded X11 connection terminated");
7480 sfree(c->u.a.message);
7483 if (c->u.pfd.pf != NULL)
7484 pfd_close(c->u.pfd.pf);
7485 logevent("Forwarded port closed");
7489 del234(ssh->channels, c);
7490 if (ssh->version == 2) {
7491 bufchain_clear(&c->v.v2.outbuffer);
7492 assert(c->v.v2.chanreq_head == NULL);
7497 * If that was the last channel left open, we might need to
7500 ssh_check_termination(ssh);
7503 static void ssh2_channel_check_close(struct ssh_channel *c)
7506 struct Packet *pktout;
7510 * If we've sent out our own CHANNEL_OPEN but not yet seen
7511 * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
7512 * it's too early to be sending close messages of any kind.
7517 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
7518 c->type == CHAN_ZOMBIE) &&
7519 !c->v.v2.chanreq_head &&
7520 !(c->closes & CLOSES_SENT_CLOSE)) {
7522 * We have both sent and received EOF (or the channel is a
7523 * zombie), and we have no outstanding channel requests, which
7524 * means the channel is in final wind-up. But we haven't sent
7525 * CLOSE, so let's do so now.
7527 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
7528 ssh2_pkt_adduint32(pktout, c->remoteid);
7529 ssh2_pkt_send(ssh, pktout);
7530 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
7533 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
7534 assert(c->v.v2.chanreq_head == NULL);
7536 * We have both sent and received CLOSE, which means we're
7537 * completely done with the channel.
7539 ssh_channel_destroy(c);
7543 static void ssh2_channel_got_eof(struct ssh_channel *c)
7545 if (c->closes & CLOSES_RCVD_EOF)
7546 return; /* already seen EOF */
7547 c->closes |= CLOSES_RCVD_EOF;
7549 if (c->type == CHAN_X11) {
7550 x11_send_eof(c->u.x11.xconn);
7551 } else if (c->type == CHAN_AGENT) {
7552 if (c->u.a.outstanding_requests == 0) {
7553 /* Manufacture an outgoing EOF in response to the incoming one. */
7554 sshfwd_write_eof(c);
7556 } else if (c->type == CHAN_SOCKDATA) {
7557 pfd_send_eof(c->u.pfd.pf);
7558 } else if (c->type == CHAN_MAINSESSION) {
7561 if (!ssh->sent_console_eof &&
7562 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
7564 * Either from_backend_eof told us that the front end
7565 * wants us to close the outgoing side of the connection
7566 * as soon as we see EOF from the far end, or else we've
7567 * unilaterally decided to do that because we've allocated
7568 * a remote pty and hence EOF isn't a particularly
7569 * meaningful concept.
7571 sshfwd_write_eof(c);
7573 ssh->sent_console_eof = TRUE;
7576 ssh2_channel_check_close(c);
7579 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
7581 struct ssh_channel *c;
7583 c = ssh2_channel_msg(ssh, pktin);
7586 if (c->type == CHAN_SHARING) {
7587 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7588 pktin->body, pktin->length);
7591 ssh2_channel_got_eof(c);
7594 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
7596 struct ssh_channel *c;
7598 c = ssh2_channel_msg(ssh, pktin);
7601 if (c->type == CHAN_SHARING) {
7602 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7603 pktin->body, pktin->length);
7608 * When we receive CLOSE on a channel, we assume it comes with an
7609 * implied EOF if we haven't seen EOF yet.
7611 ssh2_channel_got_eof(c);
7614 * And we also send an outgoing EOF, if we haven't already, on the
7615 * assumption that CLOSE is a pretty forceful announcement that
7616 * the remote side is doing away with the entire channel. (If it
7617 * had wanted to send us EOF and continue receiving data from us,
7618 * it would have just sent CHANNEL_EOF.)
7620 if (!(c->closes & CLOSES_SENT_EOF)) {
7622 * Make sure we don't read any more from whatever our local
7623 * data source is for this channel.
7626 case CHAN_MAINSESSION:
7627 ssh->send_ok = 0; /* stop trying to read from stdin */
7630 x11_override_throttle(c->u.x11.xconn, 1);
7633 pfd_override_throttle(c->u.pfd.pf, 1);
7638 * Abandon any buffered data we still wanted to send to this
7639 * channel. Receiving a CHANNEL_CLOSE is an indication that
7640 * the server really wants to get on and _destroy_ this
7641 * channel, and it isn't going to send us any further
7642 * WINDOW_ADJUSTs to permit us to send pending stuff.
7644 bufchain_clear(&c->v.v2.outbuffer);
7647 * Send outgoing EOF.
7649 sshfwd_write_eof(c);
7653 * Now process the actual close.
7655 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
7656 c->closes |= CLOSES_RCVD_CLOSE;
7657 ssh2_channel_check_close(c);
7661 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
7663 struct ssh_channel *c;
7665 c = ssh2_channel_msg(ssh, pktin);
7668 if (c->type == CHAN_SHARING) {
7669 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7670 pktin->body, pktin->length);
7673 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7674 c->remoteid = ssh_pkt_getuint32(pktin);
7675 c->halfopen = FALSE;
7676 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7677 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7679 if (c->type == CHAN_SOCKDATA_DORMANT) {
7680 c->type = CHAN_SOCKDATA;
7682 pfd_confirm(c->u.pfd.pf);
7683 } else if (c->type == CHAN_ZOMBIE) {
7685 * This case can occur if a local socket error occurred
7686 * between us sending out CHANNEL_OPEN and receiving
7687 * OPEN_CONFIRMATION. In this case, all we can do is
7688 * immediately initiate close proceedings now that we know the
7689 * server's id to put in the close message.
7691 ssh2_channel_check_close(c);
7694 * We never expect to receive OPEN_CONFIRMATION for any
7695 * *other* channel type (since only local-to-remote port
7696 * forwardings cause us to send CHANNEL_OPEN after the main
7697 * channel is live - all other auxiliary channel types are
7698 * initiated from the server end). It's safe to enforce this
7699 * by assertion rather than by ssh_disconnect, because the
7700 * real point is that we never constructed a half-open channel
7701 * structure in the first place with any type other than the
7704 assert(!"Funny channel type in ssh2_msg_channel_open_confirmation");
7708 ssh_channel_try_eof(c); /* in case we had a pending EOF */
7711 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
7713 static const char *const reasons[] = {
7714 "<unknown reason code>",
7715 "Administratively prohibited",
7717 "Unknown channel type",
7718 "Resource shortage",
7720 unsigned reason_code;
7721 char *reason_string;
7723 struct ssh_channel *c;
7725 c = ssh2_channel_msg(ssh, pktin);
7728 if (c->type == CHAN_SHARING) {
7729 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7730 pktin->body, pktin->length);
7733 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7735 if (c->type == CHAN_SOCKDATA_DORMANT) {
7736 reason_code = ssh_pkt_getuint32(pktin);
7737 if (reason_code >= lenof(reasons))
7738 reason_code = 0; /* ensure reasons[reason_code] in range */
7739 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
7740 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
7741 reasons[reason_code], reason_length, reason_string);
7743 pfd_close(c->u.pfd.pf);
7744 } else if (c->type == CHAN_ZOMBIE) {
7746 * This case can occur if a local socket error occurred
7747 * between us sending out CHANNEL_OPEN and receiving
7748 * OPEN_FAILURE. In this case, we need do nothing except allow
7749 * the code below to throw the half-open channel away.
7753 * We never expect to receive OPEN_FAILURE for any *other*
7754 * channel type (since only local-to-remote port forwardings
7755 * cause us to send CHANNEL_OPEN after the main channel is
7756 * live - all other auxiliary channel types are initiated from
7757 * the server end). It's safe to enforce this by assertion
7758 * rather than by ssh_disconnect, because the real point is
7759 * that we never constructed a half-open channel structure in
7760 * the first place with any type other than the above.
7762 assert(!"Funny channel type in ssh2_msg_channel_open_failure");
7765 del234(ssh->channels, c);
7769 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
7772 int typelen, want_reply;
7773 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
7774 struct ssh_channel *c;
7775 struct Packet *pktout;
7777 c = ssh2_channel_msg(ssh, pktin);
7780 if (c->type == CHAN_SHARING) {
7781 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7782 pktin->body, pktin->length);
7785 ssh_pkt_getstring(pktin, &type, &typelen);
7786 want_reply = ssh2_pkt_getbool(pktin);
7789 * Having got the channel number, we now look at
7790 * the request type string to see if it's something
7793 if (c == ssh->mainchan) {
7795 * We recognise "exit-status" and "exit-signal" on
7796 * the primary channel.
7798 if (typelen == 11 &&
7799 !memcmp(type, "exit-status", 11)) {
7801 ssh->exitcode = ssh_pkt_getuint32(pktin);
7802 logeventf(ssh, "Server sent command exit status %d",
7804 reply = SSH2_MSG_CHANNEL_SUCCESS;
7806 } else if (typelen == 11 &&
7807 !memcmp(type, "exit-signal", 11)) {
7809 int is_plausible = TRUE, is_int = FALSE;
7810 char *fmt_sig = "", *fmt_msg = "";
7812 int msglen = 0, core = FALSE;
7813 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
7814 * provide an `int' for the signal, despite its
7815 * having been a `string' in the drafts of RFC 4254 since at
7816 * least 2001. (Fixed in session.c 1.147.) Try to
7817 * infer which we can safely parse it as. */
7819 unsigned char *p = pktin->body +
7821 long len = pktin->length - pktin->savedpos;
7822 unsigned long num = GET_32BIT(p); /* what is it? */
7823 /* If it's 0, it hardly matters; assume string */
7827 int maybe_int = FALSE, maybe_str = FALSE;
7828 #define CHECK_HYPOTHESIS(offset, result) \
7831 int q = toint(offset); \
7832 if (q >= 0 && q+4 <= len) { \
7833 q = toint(q + 4 + GET_32BIT(p+q)); \
7834 if (q >= 0 && q+4 <= len && \
7835 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
7840 CHECK_HYPOTHESIS(4+1, maybe_int);
7841 CHECK_HYPOTHESIS(4+num+1, maybe_str);
7842 #undef CHECK_HYPOTHESIS
7843 if (maybe_int && !maybe_str)
7845 else if (!maybe_int && maybe_str)
7848 /* Crikey. Either or neither. Panic. */
7849 is_plausible = FALSE;
7852 ssh->exitcode = 128; /* means `unknown signal' */
7855 /* Old non-standard OpenSSH. */
7856 int signum = ssh_pkt_getuint32(pktin);
7857 fmt_sig = dupprintf(" %d", signum);
7858 ssh->exitcode = 128 + signum;
7860 /* As per RFC 4254. */
7863 ssh_pkt_getstring(pktin, &sig, &siglen);
7864 /* Signal name isn't supposed to be blank, but
7865 * let's cope gracefully if it is. */
7867 fmt_sig = dupprintf(" \"%.*s\"",
7872 * Really hideous method of translating the
7873 * signal description back into a locally
7874 * meaningful number.
7879 #define TRANSLATE_SIGNAL(s) \
7880 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
7881 ssh->exitcode = 128 + SIG ## s
7883 TRANSLATE_SIGNAL(ABRT);
7886 TRANSLATE_SIGNAL(ALRM);
7889 TRANSLATE_SIGNAL(FPE);
7892 TRANSLATE_SIGNAL(HUP);
7895 TRANSLATE_SIGNAL(ILL);
7898 TRANSLATE_SIGNAL(INT);
7901 TRANSLATE_SIGNAL(KILL);
7904 TRANSLATE_SIGNAL(PIPE);
7907 TRANSLATE_SIGNAL(QUIT);
7910 TRANSLATE_SIGNAL(SEGV);
7913 TRANSLATE_SIGNAL(TERM);
7916 TRANSLATE_SIGNAL(USR1);
7919 TRANSLATE_SIGNAL(USR2);
7921 #undef TRANSLATE_SIGNAL
7923 ssh->exitcode = 128;
7925 core = ssh2_pkt_getbool(pktin);
7926 ssh_pkt_getstring(pktin, &msg, &msglen);
7928 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
7930 /* ignore lang tag */
7931 } /* else don't attempt to parse */
7932 logeventf(ssh, "Server exited on signal%s%s%s",
7933 fmt_sig, core ? " (core dumped)" : "",
7935 if (*fmt_sig) sfree(fmt_sig);
7936 if (*fmt_msg) sfree(fmt_msg);
7937 reply = SSH2_MSG_CHANNEL_SUCCESS;
7942 * This is a channel request we don't know
7943 * about, so we now either ignore the request
7944 * or respond with CHANNEL_FAILURE, depending
7947 reply = SSH2_MSG_CHANNEL_FAILURE;
7950 pktout = ssh2_pkt_init(reply);
7951 ssh2_pkt_adduint32(pktout, c->remoteid);
7952 ssh2_pkt_send(ssh, pktout);
7956 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
7959 int typelen, want_reply;
7960 struct Packet *pktout;
7962 ssh_pkt_getstring(pktin, &type, &typelen);
7963 want_reply = ssh2_pkt_getbool(pktin);
7966 * We currently don't support any global requests
7967 * at all, so we either ignore the request or
7968 * respond with REQUEST_FAILURE, depending on
7972 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
7973 ssh2_pkt_send(ssh, pktout);
7977 struct X11FakeAuth *ssh_sharing_add_x11_display(Ssh ssh, int authtype,
7981 struct X11FakeAuth *auth;
7984 * Make up a new set of fake X11 auth data, and add it to the tree
7985 * of currently valid ones with an indication of the sharing
7986 * context that it's relevant to.
7988 auth = x11_invent_fake_auth(ssh->x11authtree, authtype);
7989 auth->share_cs = share_cs;
7990 auth->share_chan = share_chan;
7995 void ssh_sharing_remove_x11_display(Ssh ssh, struct X11FakeAuth *auth)
7997 del234(ssh->x11authtree, auth);
7998 x11_free_fake_auth(auth);
8001 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
8009 struct ssh_channel *c;
8010 unsigned remid, winsize, pktsize;
8011 unsigned our_winsize_override = 0;
8012 struct Packet *pktout;
8014 ssh_pkt_getstring(pktin, &type, &typelen);
8015 c = snew(struct ssh_channel);
8018 remid = ssh_pkt_getuint32(pktin);
8019 winsize = ssh_pkt_getuint32(pktin);
8020 pktsize = ssh_pkt_getuint32(pktin);
8022 if (typelen == 3 && !memcmp(type, "x11", 3)) {
8025 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8026 addrstr = snewn(peeraddrlen+1, char);
8027 memcpy(addrstr, peeraddr, peeraddrlen);
8028 addrstr[peeraddrlen] = '\0';
8029 peerport = ssh_pkt_getuint32(pktin);
8031 logeventf(ssh, "Received X11 connect request from %s:%d",
8034 if (!ssh->X11_fwd_enabled && !ssh->connshare)
8035 error = "X11 forwarding is not enabled";
8037 c->u.x11.xconn = x11_init(ssh->x11authtree, c,
8040 c->u.x11.initial = TRUE;
8043 * If we are a connection-sharing upstream, then we should
8044 * initially present a very small window, adequate to take
8045 * the X11 initial authorisation packet but not much more.
8046 * Downstream will then present us a larger window (by
8047 * fiat of the connection-sharing protocol) and we can
8048 * guarantee to send a positive-valued WINDOW_ADJUST.
8051 our_winsize_override = 128;
8053 logevent("Opened X11 forward channel");
8057 } else if (typelen == 15 &&
8058 !memcmp(type, "forwarded-tcpip", 15)) {
8059 struct ssh_rportfwd pf, *realpf;
8062 ssh_pkt_getstring(pktin, &shost, &shostlen);/* skip address */
8063 pf.shost = dupprintf("%.*s", shostlen, shost);
8064 pf.sport = ssh_pkt_getuint32(pktin);
8065 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8066 peerport = ssh_pkt_getuint32(pktin);
8067 realpf = find234(ssh->rportfwds, &pf, NULL);
8068 logeventf(ssh, "Received remote port %s:%d open request "
8069 "from %s:%d", pf.shost, pf.sport, peeraddr, peerport);
8072 if (realpf == NULL) {
8073 error = "Remote port is not recognised";
8077 if (realpf->share_ctx) {
8079 * This port forwarding is on behalf of a
8080 * connection-sharing downstream, so abandon our own
8081 * channel-open procedure and just pass the message on
8084 share_got_pkt_from_server(realpf->share_ctx, pktin->type,
8085 pktin->body, pktin->length);
8090 err = pfd_connect(&c->u.pfd.pf, realpf->dhost, realpf->dport,
8091 c, ssh->conf, realpf->pfrec->addressfamily);
8092 logeventf(ssh, "Attempting to forward remote port to "
8093 "%s:%d", realpf->dhost, realpf->dport);
8095 logeventf(ssh, "Port open failed: %s", err);
8097 error = "Port open failed";
8099 logevent("Forwarded port opened successfully");
8100 c->type = CHAN_SOCKDATA;
8103 } else if (typelen == 22 &&
8104 !memcmp(type, "auth-agent@openssh.com", 22)) {
8105 if (!ssh->agentfwd_enabled)
8106 error = "Agent forwarding is not enabled";
8108 c->type = CHAN_AGENT; /* identify channel type */
8109 c->u.a.lensofar = 0;
8110 c->u.a.message = NULL;
8111 c->u.a.outstanding_requests = 0;
8114 error = "Unsupported channel type requested";
8117 c->remoteid = remid;
8118 c->halfopen = FALSE;
8120 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
8121 ssh2_pkt_adduint32(pktout, c->remoteid);
8122 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
8123 ssh2_pkt_addstring(pktout, error);
8124 ssh2_pkt_addstring(pktout, "en"); /* language tag */
8125 ssh2_pkt_send(ssh, pktout);
8126 logeventf(ssh, "Rejected channel open: %s", error);
8129 ssh2_channel_init(c);
8130 c->v.v2.remwindow = winsize;
8131 c->v.v2.remmaxpkt = pktsize;
8132 if (our_winsize_override) {
8133 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
8134 our_winsize_override;
8136 add234(ssh->channels, c);
8137 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
8138 ssh2_pkt_adduint32(pktout, c->remoteid);
8139 ssh2_pkt_adduint32(pktout, c->localid);
8140 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
8141 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8142 ssh2_pkt_send(ssh, pktout);
8146 void sshfwd_x11_sharing_handover(struct ssh_channel *c,
8147 void *share_cs, void *share_chan,
8148 const char *peer_addr, int peer_port,
8149 int endian, int protomajor, int protominor,
8150 const void *initial_data, int initial_len)
8153 * This function is called when we've just discovered that an X
8154 * forwarding channel on which we'd been handling the initial auth
8155 * ourselves turns out to be destined for a connection-sharing
8156 * downstream. So we turn the channel into a CHAN_SHARING, meaning
8157 * that we completely stop tracking windows and buffering data and
8158 * just pass more or less unmodified SSH messages back and forth.
8160 c->type = CHAN_SHARING;
8161 c->u.sharing.ctx = share_cs;
8162 share_setup_x11_channel(share_cs, share_chan,
8163 c->localid, c->remoteid, c->v.v2.remwindow,
8164 c->v.v2.remmaxpkt, c->v.v2.locwindow,
8165 peer_addr, peer_port, endian,
8166 protomajor, protominor,
8167 initial_data, initial_len);
8170 void sshfwd_x11_is_local(struct ssh_channel *c)
8173 * This function is called when we've just discovered that an X
8174 * forwarding channel is _not_ destined for a connection-sharing
8175 * downstream but we're going to handle it ourselves. We stop
8176 * presenting a cautiously small window and go into ordinary data
8179 c->u.x11.initial = FALSE;
8180 ssh2_set_window(c, ssh_is_simple(c->ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE);
8184 * Buffer banner messages for later display at some convenient point,
8185 * if we're going to display them.
8187 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
8189 /* Arbitrary limit to prevent unbounded inflation of buffer */
8190 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
8191 bufchain_size(&ssh->banner) <= 131072) {
8192 char *banner = NULL;
8194 ssh_pkt_getstring(pktin, &banner, &size);
8196 bufchain_add(&ssh->banner, banner, size);
8200 /* Helper function to deal with sending tty modes for "pty-req" */
8201 static void ssh2_send_ttymode(void *data, char *mode, char *val)
8203 struct Packet *pktout = (struct Packet *)data;
8205 unsigned int arg = 0;
8206 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
8207 if (i == lenof(ssh_ttymodes)) return;
8208 switch (ssh_ttymodes[i].type) {
8210 arg = ssh_tty_parse_specchar(val);
8213 arg = ssh_tty_parse_boolean(val);
8216 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
8217 ssh2_pkt_adduint32(pktout, arg);
8220 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
8223 struct ssh2_setup_x11_state {
8227 struct Packet *pktout;
8228 crStateP(ssh2_setup_x11_state, ctx);
8232 logevent("Requesting X11 forwarding");
8233 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
8235 ssh2_pkt_addbool(pktout, 0); /* many connections */
8236 ssh2_pkt_addstring(pktout, ssh->x11auth->protoname);
8237 ssh2_pkt_addstring(pktout, ssh->x11auth->datastring);
8238 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
8239 ssh2_pkt_send(ssh, pktout);
8241 /* Wait to be called back with either a response packet, or NULL
8242 * meaning clean up and free our data */
8246 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8247 logevent("X11 forwarding enabled");
8248 ssh->X11_fwd_enabled = TRUE;
8250 logevent("X11 forwarding refused");
8256 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
8259 struct ssh2_setup_agent_state {
8263 struct Packet *pktout;
8264 crStateP(ssh2_setup_agent_state, ctx);
8268 logevent("Requesting OpenSSH-style agent forwarding");
8269 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
8270 ssh2_setup_agent, s);
8271 ssh2_pkt_send(ssh, pktout);
8273 /* Wait to be called back with either a response packet, or NULL
8274 * meaning clean up and free our data */
8278 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8279 logevent("Agent forwarding enabled");
8280 ssh->agentfwd_enabled = TRUE;
8282 logevent("Agent forwarding refused");
8288 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
8291 struct ssh2_setup_pty_state {
8295 struct Packet *pktout;
8296 crStateP(ssh2_setup_pty_state, ctx);
8300 /* Unpick the terminal-speed string. */
8301 /* XXX perhaps we should allow no speeds to be sent. */
8302 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
8303 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
8304 /* Build the pty request. */
8305 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
8307 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
8308 ssh2_pkt_adduint32(pktout, ssh->term_width);
8309 ssh2_pkt_adduint32(pktout, ssh->term_height);
8310 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
8311 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
8312 ssh2_pkt_addstring_start(pktout);
8313 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
8314 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
8315 ssh2_pkt_adduint32(pktout, ssh->ispeed);
8316 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
8317 ssh2_pkt_adduint32(pktout, ssh->ospeed);
8318 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
8319 ssh2_pkt_send(ssh, pktout);
8320 ssh->state = SSH_STATE_INTERMED;
8322 /* Wait to be called back with either a response packet, or NULL
8323 * meaning clean up and free our data */
8327 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8328 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
8329 ssh->ospeed, ssh->ispeed);
8330 ssh->got_pty = TRUE;
8332 c_write_str(ssh, "Server refused to allocate pty\r\n");
8333 ssh->editing = ssh->echoing = 1;
8340 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
8343 struct ssh2_setup_env_state {
8345 int num_env, env_left, env_ok;
8348 struct Packet *pktout;
8349 crStateP(ssh2_setup_env_state, ctx);
8354 * Send environment variables.
8356 * Simplest thing here is to send all the requests at once, and
8357 * then wait for a whole bunch of successes or failures.
8363 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
8365 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
8366 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
8367 ssh2_pkt_addstring(pktout, key);
8368 ssh2_pkt_addstring(pktout, val);
8369 ssh2_pkt_send(ssh, pktout);
8374 logeventf(ssh, "Sent %d environment variables", s->num_env);
8379 s->env_left = s->num_env;
8381 while (s->env_left > 0) {
8382 /* Wait to be called back with either a response packet,
8383 * or NULL meaning clean up and free our data */
8385 if (!pktin) goto out;
8386 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
8391 if (s->env_ok == s->num_env) {
8392 logevent("All environment variables successfully set");
8393 } else if (s->env_ok == 0) {
8394 logevent("All environment variables refused");
8395 c_write_str(ssh, "Server refused to set environment variables\r\n");
8397 logeventf(ssh, "%d environment variables refused",
8398 s->num_env - s->env_ok);
8399 c_write_str(ssh, "Server refused to set all environment variables\r\n");
8407 * Handle the SSH-2 userauth and connection layers.
8409 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
8411 do_ssh2_authconn(ssh, NULL, 0, pktin);
8414 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
8417 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
8420 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
8421 struct Packet *pktin)
8423 struct do_ssh2_authconn_state {
8427 AUTH_TYPE_PUBLICKEY,
8428 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
8429 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
8431 AUTH_TYPE_GSSAPI, /* always QUIET */
8432 AUTH_TYPE_KEYBOARD_INTERACTIVE,
8433 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
8435 int done_service_req;
8436 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
8437 int tried_pubkey_config, done_agent;
8442 int kbd_inter_refused;
8443 int we_are_in, userauth_success;
8444 prompts_t *cur_prompt;
8449 void *publickey_blob;
8450 int publickey_bloblen;
8451 int publickey_encrypted;
8452 char *publickey_algorithm;
8453 char *publickey_comment;
8454 unsigned char agent_request[5], *agent_response, *agentp;
8455 int agent_responselen;
8456 unsigned char *pkblob_in_agent;
8458 char *pkblob, *alg, *commentp;
8459 int pklen, alglen, commentlen;
8460 int siglen, retlen, len;
8461 char *q, *agentreq, *ret;
8463 struct Packet *pktout;
8466 struct ssh_gss_library *gsslib;
8467 Ssh_gss_ctx gss_ctx;
8468 Ssh_gss_buf gss_buf;
8469 Ssh_gss_buf gss_rcvtok, gss_sndtok;
8470 Ssh_gss_name gss_srv_name;
8471 Ssh_gss_stat gss_stat;
8474 crState(do_ssh2_authconn_state);
8478 /* Register as a handler for all the messages this coroutine handles. */
8479 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
8480 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
8481 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
8482 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
8483 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
8484 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
8485 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
8486 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
8487 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
8488 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
8489 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
8490 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
8491 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
8492 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
8493 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
8494 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
8495 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
8496 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
8497 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
8498 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
8500 s->done_service_req = FALSE;
8501 s->we_are_in = s->userauth_success = FALSE;
8502 s->agent_response = NULL;
8504 s->tried_gssapi = FALSE;
8507 if (!ssh->bare_connection) {
8508 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
8510 * Request userauth protocol, and await a response to it.
8512 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8513 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
8514 ssh2_pkt_send(ssh, s->pktout);
8515 crWaitUntilV(pktin);
8516 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
8517 s->done_service_req = TRUE;
8519 if (!s->done_service_req) {
8521 * Request connection protocol directly, without authentication.
8523 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8524 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8525 ssh2_pkt_send(ssh, s->pktout);
8526 crWaitUntilV(pktin);
8527 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
8528 s->we_are_in = TRUE; /* no auth required */
8530 bombout(("Server refused service request"));
8535 s->we_are_in = TRUE;
8538 /* Arrange to be able to deal with any BANNERs that come in.
8539 * (We do this now as packets may come in during the next bit.) */
8540 bufchain_init(&ssh->banner);
8541 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
8542 ssh2_msg_userauth_banner;
8545 * Misc one-time setup for authentication.
8547 s->publickey_blob = NULL;
8548 if (!s->we_are_in) {
8551 * Load the public half of any configured public key file
8554 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
8555 if (!filename_is_null(s->keyfile)) {
8557 logeventf(ssh, "Reading private key file \"%.150s\"",
8558 filename_to_str(s->keyfile));
8559 keytype = key_type(s->keyfile);
8560 if (keytype == SSH_KEYTYPE_SSH2) {
8563 ssh2_userkey_loadpub(s->keyfile,
8564 &s->publickey_algorithm,
8565 &s->publickey_bloblen,
8566 &s->publickey_comment, &error);
8567 if (s->publickey_blob) {
8568 s->publickey_encrypted =
8569 ssh2_userkey_encrypted(s->keyfile, NULL);
8572 logeventf(ssh, "Unable to load private key (%s)",
8574 msgbuf = dupprintf("Unable to load private key file "
8575 "\"%.150s\" (%s)\r\n",
8576 filename_to_str(s->keyfile),
8578 c_write_str(ssh, msgbuf);
8583 logeventf(ssh, "Unable to use this key file (%s)",
8584 key_type_to_str(keytype));
8585 msgbuf = dupprintf("Unable to use key file \"%.150s\""
8587 filename_to_str(s->keyfile),
8588 key_type_to_str(keytype));
8589 c_write_str(ssh, msgbuf);
8591 s->publickey_blob = NULL;
8596 * Find out about any keys Pageant has (but if there's a
8597 * public key configured, filter out all others).
8600 s->agent_response = NULL;
8601 s->pkblob_in_agent = NULL;
8602 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
8606 logevent("Pageant is running. Requesting keys.");
8608 /* Request the keys held by the agent. */
8609 PUT_32BIT(s->agent_request, 1);
8610 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
8611 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
8612 ssh_agent_callback, ssh)) {
8616 bombout(("Unexpected data from server while"
8617 " waiting for agent response"));
8620 } while (pktin || inlen > 0);
8621 r = ssh->agent_response;
8622 s->agent_responselen = ssh->agent_response_len;
8624 s->agent_response = (unsigned char *) r;
8625 if (s->agent_response && s->agent_responselen >= 5 &&
8626 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
8629 p = s->agent_response + 5;
8630 s->nkeys = toint(GET_32BIT(p));
8633 * Vet the Pageant response to ensure that the key
8634 * count and blob lengths make sense.
8637 logeventf(ssh, "Pageant response contained a negative"
8638 " key count %d", s->nkeys);
8640 goto done_agent_query;
8642 unsigned char *q = p + 4;
8643 int lenleft = s->agent_responselen - 5 - 4;
8645 for (keyi = 0; keyi < s->nkeys; keyi++) {
8646 int bloblen, commentlen;
8648 logeventf(ssh, "Pageant response was truncated");
8650 goto done_agent_query;
8652 bloblen = toint(GET_32BIT(q));
8653 if (bloblen < 0 || bloblen > lenleft) {
8654 logeventf(ssh, "Pageant response was truncated");
8656 goto done_agent_query;
8658 lenleft -= 4 + bloblen;
8660 commentlen = toint(GET_32BIT(q));
8661 if (commentlen < 0 || commentlen > lenleft) {
8662 logeventf(ssh, "Pageant response was truncated");
8664 goto done_agent_query;
8666 lenleft -= 4 + commentlen;
8667 q += 4 + commentlen;
8672 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
8673 if (s->publickey_blob) {
8674 /* See if configured key is in agent. */
8675 for (keyi = 0; keyi < s->nkeys; keyi++) {
8676 s->pklen = toint(GET_32BIT(p));
8677 if (s->pklen == s->publickey_bloblen &&
8678 !memcmp(p+4, s->publickey_blob,
8679 s->publickey_bloblen)) {
8680 logeventf(ssh, "Pageant key #%d matches "
8681 "configured key file", keyi);
8683 s->pkblob_in_agent = p;
8687 p += toint(GET_32BIT(p)) + 4; /* comment */
8689 if (!s->pkblob_in_agent) {
8690 logevent("Configured key file not in Pageant");
8695 logevent("Failed to get reply from Pageant");
8703 * We repeat this whole loop, including the username prompt,
8704 * until we manage a successful authentication. If the user
8705 * types the wrong _password_, they can be sent back to the
8706 * beginning to try another username, if this is configured on.
8707 * (If they specify a username in the config, they are never
8708 * asked, even if they do give a wrong password.)
8710 * I think this best serves the needs of
8712 * - the people who have no configuration, no keys, and just
8713 * want to try repeated (username,password) pairs until they
8714 * type both correctly
8716 * - people who have keys and configuration but occasionally
8717 * need to fall back to passwords
8719 * - people with a key held in Pageant, who might not have
8720 * logged in to a particular machine before; so they want to
8721 * type a username, and then _either_ their key will be
8722 * accepted, _or_ they will type a password. If they mistype
8723 * the username they will want to be able to get back and
8726 s->got_username = FALSE;
8727 while (!s->we_are_in) {
8731 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
8733 * We got a username last time round this loop, and
8734 * with change_username turned off we don't try to get
8737 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
8738 int ret; /* need not be kept over crReturn */
8739 s->cur_prompt = new_prompts(ssh->frontend);
8740 s->cur_prompt->to_server = TRUE;
8741 s->cur_prompt->name = dupstr("SSH login name");
8742 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
8743 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8746 crWaitUntilV(!pktin);
8747 ret = get_userpass_input(s->cur_prompt, in, inlen);
8752 * get_userpass_input() failed to get a username.
8755 free_prompts(s->cur_prompt);
8756 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
8759 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
8760 free_prompts(s->cur_prompt);
8763 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
8764 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
8765 c_write_str(ssh, stuff);
8769 s->got_username = TRUE;
8772 * Send an authentication request using method "none": (a)
8773 * just in case it succeeds, and (b) so that we know what
8774 * authentication methods we can usefully try next.
8776 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
8778 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8779 ssh2_pkt_addstring(s->pktout, ssh->username);
8780 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
8781 ssh2_pkt_addstring(s->pktout, "none"); /* method */
8782 ssh2_pkt_send(ssh, s->pktout);
8783 s->type = AUTH_TYPE_NONE;
8785 s->we_are_in = FALSE;
8787 s->tried_pubkey_config = FALSE;
8788 s->kbd_inter_refused = FALSE;
8790 /* Reset agent request state. */
8791 s->done_agent = FALSE;
8792 if (s->agent_response) {
8793 if (s->pkblob_in_agent) {
8794 s->agentp = s->pkblob_in_agent;
8796 s->agentp = s->agent_response + 5 + 4;
8802 char *methods = NULL;
8806 * Wait for the result of the last authentication request.
8809 crWaitUntilV(pktin);
8811 * Now is a convenient point to spew any banner material
8812 * that we've accumulated. (This should ensure that when
8813 * we exit the auth loop, we haven't any left to deal
8817 int size = bufchain_size(&ssh->banner);
8819 * Don't show the banner if we're operating in
8820 * non-verbose non-interactive mode. (It's probably
8821 * a script, which means nobody will read the
8822 * banner _anyway_, and moreover the printing of
8823 * the banner will screw up processing on the
8824 * output of (say) plink.)
8826 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
8827 char *banner = snewn(size, char);
8828 bufchain_fetch(&ssh->banner, banner, size);
8829 c_write_untrusted(ssh, banner, size);
8832 bufchain_clear(&ssh->banner);
8834 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
8835 logevent("Access granted");
8836 s->we_are_in = s->userauth_success = TRUE;
8840 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
8841 bombout(("Strange packet received during authentication: "
8842 "type %d", pktin->type));
8849 * OK, we're now sitting on a USERAUTH_FAILURE message, so
8850 * we can look at the string in it and know what we can
8851 * helpfully try next.
8853 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
8854 ssh_pkt_getstring(pktin, &methods, &methlen);
8855 if (!ssh2_pkt_getbool(pktin)) {
8857 * We have received an unequivocal Access
8858 * Denied. This can translate to a variety of
8859 * messages, or no message at all.
8861 * For forms of authentication which are attempted
8862 * implicitly, by which I mean without printing
8863 * anything in the window indicating that we're
8864 * trying them, we should never print 'Access
8867 * If we do print a message saying that we're
8868 * attempting some kind of authentication, it's OK
8869 * to print a followup message saying it failed -
8870 * but the message may sometimes be more specific
8871 * than simply 'Access denied'.
8873 * Additionally, if we'd just tried password
8874 * authentication, we should break out of this
8875 * whole loop so as to go back to the username
8876 * prompt (iff we're configured to allow
8877 * username change attempts).
8879 if (s->type == AUTH_TYPE_NONE) {
8881 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
8882 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
8883 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
8884 c_write_str(ssh, "Server refused our key\r\n");
8885 logevent("Server refused our key");
8886 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
8887 /* This _shouldn't_ happen except by a
8888 * protocol bug causing client and server to
8889 * disagree on what is a correct signature. */
8890 c_write_str(ssh, "Server refused public-key signature"
8891 " despite accepting key!\r\n");
8892 logevent("Server refused public-key signature"
8893 " despite accepting key!");
8894 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
8895 /* quiet, so no c_write */
8896 logevent("Server refused keyboard-interactive authentication");
8897 } else if (s->type==AUTH_TYPE_GSSAPI) {
8898 /* always quiet, so no c_write */
8899 /* also, the code down in the GSSAPI block has
8900 * already logged this in the Event Log */
8901 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
8902 logevent("Keyboard-interactive authentication failed");
8903 c_write_str(ssh, "Access denied\r\n");
8905 assert(s->type == AUTH_TYPE_PASSWORD);
8906 logevent("Password authentication failed");
8907 c_write_str(ssh, "Access denied\r\n");
8909 if (conf_get_int(ssh->conf, CONF_change_username)) {
8910 /* XXX perhaps we should allow
8911 * keyboard-interactive to do this too? */
8912 s->we_are_in = FALSE;
8917 c_write_str(ssh, "Further authentication required\r\n");
8918 logevent("Further authentication required");
8922 in_commasep_string("publickey", methods, methlen);
8924 in_commasep_string("password", methods, methlen);
8925 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
8926 in_commasep_string("keyboard-interactive", methods, methlen);
8929 ssh->gsslibs = ssh_gss_setup(ssh->conf);
8930 s->can_gssapi = conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
8931 in_commasep_string("gssapi-with-mic", methods, methlen) &&
8932 ssh->gsslibs->nlibraries > 0;
8936 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
8938 if (s->can_pubkey && !s->done_agent && s->nkeys) {
8941 * Attempt public-key authentication using a key from Pageant.
8944 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
8946 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
8948 /* Unpack key from agent response */
8949 s->pklen = toint(GET_32BIT(s->agentp));
8951 s->pkblob = (char *)s->agentp;
8952 s->agentp += s->pklen;
8953 s->alglen = toint(GET_32BIT(s->pkblob));
8954 s->alg = s->pkblob + 4;
8955 s->commentlen = toint(GET_32BIT(s->agentp));
8957 s->commentp = (char *)s->agentp;
8958 s->agentp += s->commentlen;
8959 /* s->agentp now points at next key, if any */
8961 /* See if server will accept it */
8962 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8963 ssh2_pkt_addstring(s->pktout, ssh->username);
8964 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8965 /* service requested */
8966 ssh2_pkt_addstring(s->pktout, "publickey");
8968 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
8969 ssh2_pkt_addstring_start(s->pktout);
8970 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
8971 ssh2_pkt_addstring_start(s->pktout);
8972 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
8973 ssh2_pkt_send(ssh, s->pktout);
8974 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
8976 crWaitUntilV(pktin);
8977 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
8979 /* Offer of key refused. */
8986 if (flags & FLAG_VERBOSE) {
8987 c_write_str(ssh, "Authenticating with "
8989 c_write(ssh, s->commentp, s->commentlen);
8990 c_write_str(ssh, "\" from agent\r\n");
8994 * Server is willing to accept the key.
8995 * Construct a SIGN_REQUEST.
8997 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8998 ssh2_pkt_addstring(s->pktout, ssh->username);
8999 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9000 /* service requested */
9001 ssh2_pkt_addstring(s->pktout, "publickey");
9003 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
9004 ssh2_pkt_addstring_start(s->pktout);
9005 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9006 ssh2_pkt_addstring_start(s->pktout);
9007 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9009 /* Ask agent for signature. */
9010 s->siglen = s->pktout->length - 5 + 4 +
9011 ssh->v2_session_id_len;
9012 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9014 s->len = 1; /* message type */
9015 s->len += 4 + s->pklen; /* key blob */
9016 s->len += 4 + s->siglen; /* data to sign */
9017 s->len += 4; /* flags */
9018 s->agentreq = snewn(4 + s->len, char);
9019 PUT_32BIT(s->agentreq, s->len);
9020 s->q = s->agentreq + 4;
9021 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
9022 PUT_32BIT(s->q, s->pklen);
9024 memcpy(s->q, s->pkblob, s->pklen);
9026 PUT_32BIT(s->q, s->siglen);
9028 /* Now the data to be signed... */
9029 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9030 PUT_32BIT(s->q, ssh->v2_session_id_len);
9033 memcpy(s->q, ssh->v2_session_id,
9034 ssh->v2_session_id_len);
9035 s->q += ssh->v2_session_id_len;
9036 memcpy(s->q, s->pktout->data + 5,
9037 s->pktout->length - 5);
9038 s->q += s->pktout->length - 5;
9039 /* And finally the (zero) flags word. */
9041 if (!agent_query(s->agentreq, s->len + 4,
9043 ssh_agent_callback, ssh)) {
9047 bombout(("Unexpected data from server"
9048 " while waiting for agent"
9052 } while (pktin || inlen > 0);
9053 vret = ssh->agent_response;
9054 s->retlen = ssh->agent_response_len;
9059 if (s->retlen >= 9 &&
9060 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
9061 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
9062 logevent("Sending Pageant's response");
9063 ssh2_add_sigblob(ssh, s->pktout,
9064 s->pkblob, s->pklen,
9066 GET_32BIT(s->ret + 5));
9067 ssh2_pkt_send(ssh, s->pktout);
9068 s->type = AUTH_TYPE_PUBLICKEY;
9070 /* FIXME: less drastic response */
9071 bombout(("Pageant failed to answer challenge"));
9077 /* Do we have any keys left to try? */
9078 if (s->pkblob_in_agent) {
9079 s->done_agent = TRUE;
9080 s->tried_pubkey_config = TRUE;
9083 if (s->keyi >= s->nkeys)
9084 s->done_agent = TRUE;
9087 } else if (s->can_pubkey && s->publickey_blob &&
9088 !s->tried_pubkey_config) {
9090 struct ssh2_userkey *key; /* not live over crReturn */
9091 char *passphrase; /* not live over crReturn */
9093 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9095 s->tried_pubkey_config = TRUE;
9098 * Try the public key supplied in the configuration.
9100 * First, offer the public blob to see if the server is
9101 * willing to accept it.
9103 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9104 ssh2_pkt_addstring(s->pktout, ssh->username);
9105 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9106 /* service requested */
9107 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
9108 ssh2_pkt_addbool(s->pktout, FALSE);
9109 /* no signature included */
9110 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
9111 ssh2_pkt_addstring_start(s->pktout);
9112 ssh2_pkt_addstring_data(s->pktout,
9113 (char *)s->publickey_blob,
9114 s->publickey_bloblen);
9115 ssh2_pkt_send(ssh, s->pktout);
9116 logevent("Offered public key");
9118 crWaitUntilV(pktin);
9119 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9120 /* Key refused. Give up. */
9121 s->gotit = TRUE; /* reconsider message next loop */
9122 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
9123 continue; /* process this new message */
9125 logevent("Offer of public key accepted");
9128 * Actually attempt a serious authentication using
9131 if (flags & FLAG_VERBOSE) {
9132 c_write_str(ssh, "Authenticating with public key \"");
9133 c_write_str(ssh, s->publickey_comment);
9134 c_write_str(ssh, "\"\r\n");
9138 const char *error; /* not live over crReturn */
9139 if (s->publickey_encrypted) {
9141 * Get a passphrase from the user.
9143 int ret; /* need not be kept over crReturn */
9144 s->cur_prompt = new_prompts(ssh->frontend);
9145 s->cur_prompt->to_server = FALSE;
9146 s->cur_prompt->name = dupstr("SSH key passphrase");
9147 add_prompt(s->cur_prompt,
9148 dupprintf("Passphrase for key \"%.100s\": ",
9149 s->publickey_comment),
9151 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9154 crWaitUntilV(!pktin);
9155 ret = get_userpass_input(s->cur_prompt,
9160 /* Failed to get a passphrase. Terminate. */
9161 free_prompts(s->cur_prompt);
9162 ssh_disconnect(ssh, NULL,
9163 "Unable to authenticate",
9164 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9169 dupstr(s->cur_prompt->prompts[0]->result);
9170 free_prompts(s->cur_prompt);
9172 passphrase = NULL; /* no passphrase needed */
9176 * Try decrypting the key.
9178 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9179 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
9181 /* burn the evidence */
9182 smemclr(passphrase, strlen(passphrase));
9185 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
9187 (key == SSH2_WRONG_PASSPHRASE)) {
9188 c_write_str(ssh, "Wrong passphrase\r\n");
9190 /* and loop again */
9192 c_write_str(ssh, "Unable to load private key (");
9193 c_write_str(ssh, error);
9194 c_write_str(ssh, ")\r\n");
9196 break; /* try something else */
9202 unsigned char *pkblob, *sigblob, *sigdata;
9203 int pkblob_len, sigblob_len, sigdata_len;
9207 * We have loaded the private key and the server
9208 * has announced that it's willing to accept it.
9209 * Hallelujah. Generate a signature and send it.
9211 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9212 ssh2_pkt_addstring(s->pktout, ssh->username);
9213 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9214 /* service requested */
9215 ssh2_pkt_addstring(s->pktout, "publickey");
9217 ssh2_pkt_addbool(s->pktout, TRUE);
9218 /* signature follows */
9219 ssh2_pkt_addstring(s->pktout, key->alg->name);
9220 pkblob = key->alg->public_blob(key->data,
9222 ssh2_pkt_addstring_start(s->pktout);
9223 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
9227 * The data to be signed is:
9231 * followed by everything so far placed in the
9234 sigdata_len = s->pktout->length - 5 + 4 +
9235 ssh->v2_session_id_len;
9236 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9238 sigdata = snewn(sigdata_len, unsigned char);
9240 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9241 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
9244 memcpy(sigdata+p, ssh->v2_session_id,
9245 ssh->v2_session_id_len);
9246 p += ssh->v2_session_id_len;
9247 memcpy(sigdata+p, s->pktout->data + 5,
9248 s->pktout->length - 5);
9249 p += s->pktout->length - 5;
9250 assert(p == sigdata_len);
9251 sigblob = key->alg->sign(key->data, (char *)sigdata,
9252 sigdata_len, &sigblob_len);
9253 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
9254 sigblob, sigblob_len);
9259 ssh2_pkt_send(ssh, s->pktout);
9260 logevent("Sent public key signature");
9261 s->type = AUTH_TYPE_PUBLICKEY;
9262 key->alg->freekey(key->data);
9266 } else if (s->can_gssapi && !s->tried_gssapi) {
9268 /* GSSAPI Authentication */
9273 s->type = AUTH_TYPE_GSSAPI;
9274 s->tried_gssapi = TRUE;
9276 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
9279 * Pick the highest GSS library on the preference
9285 for (i = 0; i < ngsslibs; i++) {
9286 int want_id = conf_get_int_int(ssh->conf,
9287 CONF_ssh_gsslist, i);
9288 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
9289 if (ssh->gsslibs->libraries[j].id == want_id) {
9290 s->gsslib = &ssh->gsslibs->libraries[j];
9291 goto got_gsslib; /* double break */
9296 * We always expect to have found something in
9297 * the above loop: we only came here if there
9298 * was at least one viable GSS library, and the
9299 * preference list should always mention
9300 * everything and only change the order.
9305 if (s->gsslib->gsslogmsg)
9306 logevent(s->gsslib->gsslogmsg);
9308 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
9309 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9310 ssh2_pkt_addstring(s->pktout, ssh->username);
9311 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9312 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
9313 logevent("Attempting GSSAPI authentication");
9315 /* add mechanism info */
9316 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
9318 /* number of GSSAPI mechanisms */
9319 ssh2_pkt_adduint32(s->pktout,1);
9321 /* length of OID + 2 */
9322 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
9323 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
9326 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
9328 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
9330 ssh2_pkt_send(ssh, s->pktout);
9331 crWaitUntilV(pktin);
9332 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
9333 logevent("GSSAPI authentication request refused");
9337 /* check returned packet ... */
9339 ssh_pkt_getstring(pktin, &data, &len);
9340 s->gss_rcvtok.value = data;
9341 s->gss_rcvtok.length = len;
9342 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
9343 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
9344 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
9345 memcmp((char *)s->gss_rcvtok.value + 2,
9346 s->gss_buf.value,s->gss_buf.length) ) {
9347 logevent("GSSAPI authentication - wrong response from server");
9351 /* now start running */
9352 s->gss_stat = s->gsslib->import_name(s->gsslib,
9355 if (s->gss_stat != SSH_GSS_OK) {
9356 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
9357 logevent("GSSAPI import name failed - Bad service name");
9359 logevent("GSSAPI import name failed");
9363 /* fetch TGT into GSS engine */
9364 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
9366 if (s->gss_stat != SSH_GSS_OK) {
9367 logevent("GSSAPI authentication failed to get credentials");
9368 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9372 /* initial tokens are empty */
9373 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
9374 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
9376 /* now enter the loop */
9378 s->gss_stat = s->gsslib->init_sec_context
9382 conf_get_int(ssh->conf, CONF_gssapifwd),
9386 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
9387 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
9388 logevent("GSSAPI authentication initialisation failed");
9390 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
9391 &s->gss_buf) == SSH_GSS_OK) {
9392 logevent(s->gss_buf.value);
9393 sfree(s->gss_buf.value);
9398 logevent("GSSAPI authentication initialised");
9400 /* Client and server now exchange tokens until GSSAPI
9401 * no longer says CONTINUE_NEEDED */
9403 if (s->gss_sndtok.length != 0) {
9404 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
9405 ssh_pkt_addstring_start(s->pktout);
9406 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
9407 ssh2_pkt_send(ssh, s->pktout);
9408 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
9411 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
9412 crWaitUntilV(pktin);
9413 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
9414 logevent("GSSAPI authentication - bad server response");
9415 s->gss_stat = SSH_GSS_FAILURE;
9418 ssh_pkt_getstring(pktin, &data, &len);
9419 s->gss_rcvtok.value = data;
9420 s->gss_rcvtok.length = len;
9422 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
9424 if (s->gss_stat != SSH_GSS_OK) {
9425 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9426 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9429 logevent("GSSAPI authentication loop finished OK");
9431 /* Now send the MIC */
9433 s->pktout = ssh2_pkt_init(0);
9434 micoffset = s->pktout->length;
9435 ssh_pkt_addstring_start(s->pktout);
9436 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
9437 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
9438 ssh_pkt_addstring(s->pktout, ssh->username);
9439 ssh_pkt_addstring(s->pktout, "ssh-connection");
9440 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
9442 s->gss_buf.value = (char *)s->pktout->data + micoffset;
9443 s->gss_buf.length = s->pktout->length - micoffset;
9445 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
9446 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
9447 ssh_pkt_addstring_start(s->pktout);
9448 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
9449 ssh2_pkt_send(ssh, s->pktout);
9450 s->gsslib->free_mic(s->gsslib, &mic);
9454 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9455 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9458 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
9461 * Keyboard-interactive authentication.
9464 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
9466 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
9468 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9469 ssh2_pkt_addstring(s->pktout, ssh->username);
9470 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9471 /* service requested */
9472 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
9474 ssh2_pkt_addstring(s->pktout, ""); /* lang */
9475 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
9476 ssh2_pkt_send(ssh, s->pktout);
9478 logevent("Attempting keyboard-interactive authentication");
9480 crWaitUntilV(pktin);
9481 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
9482 /* Server is not willing to do keyboard-interactive
9483 * at all (or, bizarrely but legally, accepts the
9484 * user without actually issuing any prompts).
9485 * Give up on it entirely. */
9487 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
9488 s->kbd_inter_refused = TRUE; /* don't try it again */
9493 * Loop while the server continues to send INFO_REQUESTs.
9495 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
9497 char *name, *inst, *lang;
9498 int name_len, inst_len, lang_len;
9502 * We've got a fresh USERAUTH_INFO_REQUEST.
9503 * Get the preamble and start building a prompt.
9505 ssh_pkt_getstring(pktin, &name, &name_len);
9506 ssh_pkt_getstring(pktin, &inst, &inst_len);
9507 ssh_pkt_getstring(pktin, &lang, &lang_len);
9508 s->cur_prompt = new_prompts(ssh->frontend);
9509 s->cur_prompt->to_server = TRUE;
9512 * Get any prompt(s) from the packet.
9514 s->num_prompts = ssh_pkt_getuint32(pktin);
9515 for (i = 0; i < s->num_prompts; i++) {
9519 static char noprompt[] =
9520 "<server failed to send prompt>: ";
9522 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9523 echo = ssh2_pkt_getbool(pktin);
9526 prompt_len = lenof(noprompt)-1;
9528 add_prompt(s->cur_prompt,
9529 dupprintf("%.*s", prompt_len, prompt),
9534 /* FIXME: better prefix to distinguish from
9536 s->cur_prompt->name =
9537 dupprintf("SSH server: %.*s", name_len, name);
9538 s->cur_prompt->name_reqd = TRUE;
9540 s->cur_prompt->name =
9541 dupstr("SSH server authentication");
9542 s->cur_prompt->name_reqd = FALSE;
9544 /* We add a prefix to try to make it clear that a prompt
9545 * has come from the server.
9546 * FIXME: ugly to print "Using..." in prompt _every_
9547 * time round. Can this be done more subtly? */
9548 /* Special case: for reasons best known to themselves,
9549 * some servers send k-i requests with no prompts and
9550 * nothing to display. Keep quiet in this case. */
9551 if (s->num_prompts || name_len || inst_len) {
9552 s->cur_prompt->instruction =
9553 dupprintf("Using keyboard-interactive authentication.%s%.*s",
9554 inst_len ? "\n" : "", inst_len, inst);
9555 s->cur_prompt->instr_reqd = TRUE;
9557 s->cur_prompt->instr_reqd = FALSE;
9561 * Display any instructions, and get the user's
9565 int ret; /* not live over crReturn */
9566 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9569 crWaitUntilV(!pktin);
9570 ret = get_userpass_input(s->cur_prompt, in, inlen);
9575 * Failed to get responses. Terminate.
9577 free_prompts(s->cur_prompt);
9578 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9579 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9586 * Send the response(s) to the server.
9588 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
9589 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
9590 for (i=0; i < s->num_prompts; i++) {
9591 ssh2_pkt_addstring(s->pktout,
9592 s->cur_prompt->prompts[i]->result);
9594 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9597 * Free the prompts structure from this iteration.
9598 * If there's another, a new one will be allocated
9599 * when we return to the top of this while loop.
9601 free_prompts(s->cur_prompt);
9604 * Get the next packet in case it's another
9607 crWaitUntilV(pktin);
9612 * We should have SUCCESS or FAILURE now.
9616 } else if (s->can_passwd) {
9619 * Plain old password authentication.
9621 int ret; /* not live over crReturn */
9622 int changereq_first_time; /* not live over crReturn */
9624 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
9626 s->cur_prompt = new_prompts(ssh->frontend);
9627 s->cur_prompt->to_server = TRUE;
9628 s->cur_prompt->name = dupstr("SSH password");
9629 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
9634 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9637 crWaitUntilV(!pktin);
9638 ret = get_userpass_input(s->cur_prompt, in, inlen);
9643 * Failed to get responses. Terminate.
9645 free_prompts(s->cur_prompt);
9646 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9647 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9652 * Squirrel away the password. (We may need it later if
9653 * asked to change it.)
9655 s->password = dupstr(s->cur_prompt->prompts[0]->result);
9656 free_prompts(s->cur_prompt);
9659 * Send the password packet.
9661 * We pad out the password packet to 256 bytes to make
9662 * it harder for an attacker to find the length of the
9665 * Anyone using a password longer than 256 bytes
9666 * probably doesn't have much to worry about from
9667 * people who find out how long their password is!
9669 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9670 ssh2_pkt_addstring(s->pktout, ssh->username);
9671 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9672 /* service requested */
9673 ssh2_pkt_addstring(s->pktout, "password");
9674 ssh2_pkt_addbool(s->pktout, FALSE);
9675 ssh2_pkt_addstring(s->pktout, s->password);
9676 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9677 logevent("Sent password");
9678 s->type = AUTH_TYPE_PASSWORD;
9681 * Wait for next packet, in case it's a password change
9684 crWaitUntilV(pktin);
9685 changereq_first_time = TRUE;
9687 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
9690 * We're being asked for a new password
9691 * (perhaps not for the first time).
9692 * Loop until the server accepts it.
9695 int got_new = FALSE; /* not live over crReturn */
9696 char *prompt; /* not live over crReturn */
9697 int prompt_len; /* not live over crReturn */
9701 if (changereq_first_time)
9702 msg = "Server requested password change";
9704 msg = "Server rejected new password";
9706 c_write_str(ssh, msg);
9707 c_write_str(ssh, "\r\n");
9710 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9712 s->cur_prompt = new_prompts(ssh->frontend);
9713 s->cur_prompt->to_server = TRUE;
9714 s->cur_prompt->name = dupstr("New SSH password");
9715 s->cur_prompt->instruction =
9716 dupprintf("%.*s", prompt_len, prompt);
9717 s->cur_prompt->instr_reqd = TRUE;
9719 * There's no explicit requirement in the protocol
9720 * for the "old" passwords in the original and
9721 * password-change messages to be the same, and
9722 * apparently some Cisco kit supports password change
9723 * by the user entering a blank password originally
9724 * and the real password subsequently, so,
9725 * reluctantly, we prompt for the old password again.
9727 * (On the other hand, some servers don't even bother
9728 * to check this field.)
9730 add_prompt(s->cur_prompt,
9731 dupstr("Current password (blank for previously entered password): "),
9733 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
9735 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
9739 * Loop until the user manages to enter the same
9744 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9747 crWaitUntilV(!pktin);
9748 ret = get_userpass_input(s->cur_prompt, in, inlen);
9753 * Failed to get responses. Terminate.
9755 /* burn the evidence */
9756 free_prompts(s->cur_prompt);
9757 smemclr(s->password, strlen(s->password));
9759 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9760 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9766 * If the user specified a new original password
9767 * (IYSWIM), overwrite any previously specified
9769 * (A side effect is that the user doesn't have to
9770 * re-enter it if they louse up the new password.)
9772 if (s->cur_prompt->prompts[0]->result[0]) {
9773 smemclr(s->password, strlen(s->password));
9774 /* burn the evidence */
9777 dupstr(s->cur_prompt->prompts[0]->result);
9781 * Check the two new passwords match.
9783 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
9784 s->cur_prompt->prompts[2]->result)
9787 /* They don't. Silly user. */
9788 c_write_str(ssh, "Passwords do not match\r\n");
9793 * Send the new password (along with the old one).
9794 * (see above for padding rationale)
9796 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9797 ssh2_pkt_addstring(s->pktout, ssh->username);
9798 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9799 /* service requested */
9800 ssh2_pkt_addstring(s->pktout, "password");
9801 ssh2_pkt_addbool(s->pktout, TRUE);
9802 ssh2_pkt_addstring(s->pktout, s->password);
9803 ssh2_pkt_addstring(s->pktout,
9804 s->cur_prompt->prompts[1]->result);
9805 free_prompts(s->cur_prompt);
9806 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9807 logevent("Sent new password");
9810 * Now see what the server has to say about it.
9811 * (If it's CHANGEREQ again, it's not happy with the
9814 crWaitUntilV(pktin);
9815 changereq_first_time = FALSE;
9820 * We need to reexamine the current pktin at the top
9821 * of the loop. Either:
9822 * - we weren't asked to change password at all, in
9823 * which case it's a SUCCESS or FAILURE with the
9825 * - we sent a new password, and the server was
9826 * either OK with it (SUCCESS or FAILURE w/partial
9827 * success) or unhappy with the _old_ password
9828 * (FAILURE w/o partial success)
9829 * In any of these cases, we go back to the top of
9830 * the loop and start again.
9835 * We don't need the old password any more, in any
9836 * case. Burn the evidence.
9838 smemclr(s->password, strlen(s->password));
9842 char *str = dupprintf("No supported authentication methods available"
9843 " (server sent: %.*s)",
9846 ssh_disconnect(ssh, str,
9847 "No supported authentication methods available",
9848 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
9858 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
9860 /* Clear up various bits and pieces from authentication. */
9861 if (s->publickey_blob) {
9862 sfree(s->publickey_blob);
9863 sfree(s->publickey_comment);
9865 if (s->agent_response)
9866 sfree(s->agent_response);
9868 if (s->userauth_success && !ssh->bare_connection) {
9870 * We've just received USERAUTH_SUCCESS, and we haven't sent any
9871 * packets since. Signal the transport layer to consider enacting
9872 * delayed compression.
9874 * (Relying on we_are_in is not sufficient, as
9875 * draft-miller-secsh-compression-delayed is quite clear that it
9876 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
9877 * become set for other reasons.)
9879 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
9882 ssh->channels = newtree234(ssh_channelcmp);
9885 * Set up handlers for some connection protocol messages, so we
9886 * don't have to handle them repeatedly in this coroutine.
9888 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
9889 ssh2_msg_channel_window_adjust;
9890 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
9891 ssh2_msg_global_request;
9894 * Create the main session channel.
9896 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
9897 ssh->mainchan = NULL;
9899 ssh->mainchan = snew(struct ssh_channel);
9900 ssh->mainchan->ssh = ssh;
9901 ssh2_channel_init(ssh->mainchan);
9903 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
9905 * Just start a direct-tcpip channel and use it as the main
9908 ssh_send_port_open(ssh->mainchan,
9909 conf_get_str(ssh->conf, CONF_ssh_nc_host),
9910 conf_get_int(ssh->conf, CONF_ssh_nc_port),
9914 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
9915 logevent("Opening session as main channel");
9916 ssh2_pkt_send(ssh, s->pktout);
9917 ssh->ncmode = FALSE;
9919 crWaitUntilV(pktin);
9920 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
9921 bombout(("Server refused to open channel"));
9923 /* FIXME: error data comes back in FAILURE packet */
9925 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
9926 bombout(("Server's channel confirmation cited wrong channel"));
9929 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
9930 ssh->mainchan->halfopen = FALSE;
9931 ssh->mainchan->type = CHAN_MAINSESSION;
9932 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
9933 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
9934 add234(ssh->channels, ssh->mainchan);
9935 update_specials_menu(ssh->frontend);
9936 logevent("Opened main channel");
9940 * Now we have a channel, make dispatch table entries for
9941 * general channel-based messages.
9943 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
9944 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
9945 ssh2_msg_channel_data;
9946 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
9947 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
9948 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
9949 ssh2_msg_channel_open_confirmation;
9950 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
9951 ssh2_msg_channel_open_failure;
9952 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
9953 ssh2_msg_channel_request;
9954 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
9955 ssh2_msg_channel_open;
9956 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
9957 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
9960 * Now the connection protocol is properly up and running, with
9961 * all those dispatch table entries, so it's safe to let
9962 * downstreams start trying to open extra channels through us.
9965 share_activate(ssh->connshare, ssh->v_s);
9967 if (ssh->mainchan && ssh_is_simple(ssh)) {
9969 * This message indicates to the server that we promise
9970 * not to try to run any other channel in parallel with
9971 * this one, so it's safe for it to advertise a very large
9972 * window and leave the flow control to TCP.
9974 s->pktout = ssh2_chanreq_init(ssh->mainchan,
9975 "simple@putty.projects.tartarus.org",
9977 ssh2_pkt_send(ssh, s->pktout);
9981 * Enable port forwardings.
9983 ssh_setup_portfwd(ssh, ssh->conf);
9985 if (ssh->mainchan && !ssh->ncmode) {
9987 * Send the CHANNEL_REQUESTS for the main session channel.
9988 * Each one is handled by its own little asynchronous
9992 /* Potentially enable X11 forwarding. */
9993 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
9995 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
9997 if (!ssh->x11disp) {
9998 /* FIXME: return an error message from x11_setup_display */
9999 logevent("X11 forwarding not enabled: unable to"
10000 " initialise X display");
10002 ssh->x11auth = x11_invent_fake_auth
10003 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
10004 ssh->x11auth->disp = ssh->x11disp;
10006 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
10010 /* Potentially enable agent forwarding. */
10011 if (ssh_agent_forwarding_permitted(ssh))
10012 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
10014 /* Now allocate a pty for the session. */
10015 if (!conf_get_int(ssh->conf, CONF_nopty))
10016 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
10018 /* Send environment variables. */
10019 ssh2_setup_env(ssh->mainchan, NULL, NULL);
10022 * Start a shell or a remote command. We may have to attempt
10023 * this twice if the config data has provided a second choice
10030 if (ssh->fallback_cmd) {
10031 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
10032 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
10034 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
10035 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
10039 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
10040 ssh2_response_authconn, NULL);
10041 ssh2_pkt_addstring(s->pktout, cmd);
10043 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
10044 ssh2_response_authconn, NULL);
10045 ssh2_pkt_addstring(s->pktout, cmd);
10047 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
10048 ssh2_response_authconn, NULL);
10050 ssh2_pkt_send(ssh, s->pktout);
10052 crWaitUntilV(pktin);
10054 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
10055 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
10056 bombout(("Unexpected response to shell/command request:"
10057 " packet type %d", pktin->type));
10061 * We failed to start the command. If this is the
10062 * fallback command, we really are finished; if it's
10063 * not, and if the fallback command exists, try falling
10064 * back to it before complaining.
10066 if (!ssh->fallback_cmd &&
10067 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
10068 logevent("Primary command failed; attempting fallback");
10069 ssh->fallback_cmd = TRUE;
10072 bombout(("Server refused to start a shell/command"));
10075 logevent("Started a shell/command");
10080 ssh->editing = ssh->echoing = TRUE;
10083 ssh->state = SSH_STATE_SESSION;
10084 if (ssh->size_needed)
10085 ssh_size(ssh, ssh->term_width, ssh->term_height);
10086 if (ssh->eof_needed)
10087 ssh_special(ssh, TS_EOF);
10093 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
10098 s->try_send = FALSE;
10102 * _All_ the connection-layer packets we expect to
10103 * receive are now handled by the dispatch table.
10104 * Anything that reaches here must be bogus.
10107 bombout(("Strange packet received: type %d", pktin->type));
10109 } else if (ssh->mainchan) {
10111 * We have spare data. Add it to the channel buffer.
10113 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
10114 s->try_send = TRUE;
10118 struct ssh_channel *c;
10120 * Try to send data on all channels if we can.
10122 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
10123 ssh2_try_send_and_unthrottle(ssh, c);
10131 * Handlers for SSH-2 messages that might arrive at any moment.
10133 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
10135 /* log reason code in disconnect message */
10137 int reason, msglen;
10139 reason = ssh_pkt_getuint32(pktin);
10140 ssh_pkt_getstring(pktin, &msg, &msglen);
10142 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
10143 buf = dupprintf("Received disconnect message (%s)",
10144 ssh2_disconnect_reasons[reason]);
10146 buf = dupprintf("Received disconnect message (unknown"
10147 " type %d)", reason);
10151 buf = dupprintf("Disconnection message text: %.*s",
10154 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
10156 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
10157 ssh2_disconnect_reasons[reason] : "unknown",
10162 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
10164 /* log the debug message */
10168 /* XXX maybe we should actually take notice of the return value */
10169 ssh2_pkt_getbool(pktin);
10170 ssh_pkt_getstring(pktin, &msg, &msglen);
10172 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
10175 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
10177 do_ssh2_transport(ssh, NULL, 0, pktin);
10181 * Called if we receive a packet that isn't allowed by the protocol.
10182 * This only applies to packets whose meaning PuTTY understands.
10183 * Entirely unknown packets are handled below.
10185 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
10187 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
10188 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
10190 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
10194 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
10196 struct Packet *pktout;
10197 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
10198 ssh2_pkt_adduint32(pktout, pktin->sequence);
10200 * UNIMPLEMENTED messages MUST appear in the same order as the
10201 * messages they respond to. Hence, never queue them.
10203 ssh2_pkt_send_noqueue(ssh, pktout);
10207 * Handle the top-level SSH-2 protocol.
10209 static void ssh2_protocol_setup(Ssh ssh)
10214 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10216 for (i = 0; i < 256; i++)
10217 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10220 * Initially, we only accept transport messages (and a few generic
10221 * ones). do_ssh2_authconn will add more when it starts.
10222 * Messages that are understood but not currently acceptable go to
10223 * ssh2_msg_unexpected.
10225 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10226 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
10227 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
10228 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
10229 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
10230 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
10231 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
10232 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
10233 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
10234 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
10235 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
10236 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
10237 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
10238 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
10239 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
10240 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
10241 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
10242 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
10243 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
10244 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10245 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10246 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10247 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10248 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10249 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10250 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10251 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10252 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10253 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10254 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10255 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10256 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10257 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10260 * These messages have a special handler from the start.
10262 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10263 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
10264 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10267 static void ssh2_bare_connection_protocol_setup(Ssh ssh)
10272 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10274 for (i = 0; i < 256; i++)
10275 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10278 * Initially, we set all ssh-connection messages to 'unexpected';
10279 * do_ssh2_authconn will fill things in properly. We also handle a
10280 * couple of messages from the transport protocol which aren't
10281 * related to key exchange (UNIMPLEMENTED, IGNORE, DEBUG,
10284 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10285 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10286 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10287 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10288 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10289 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10290 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10291 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10292 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10293 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10294 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10295 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10296 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10297 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10299 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10302 * These messages have a special handler from the start.
10304 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10305 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore;
10306 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10309 static void ssh2_timer(void *ctx, unsigned long now)
10311 Ssh ssh = (Ssh)ctx;
10313 if (ssh->state == SSH_STATE_CLOSED)
10316 if (!ssh->kex_in_progress && !ssh->bare_connection &&
10317 conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
10318 now == ssh->next_rekey) {
10319 do_ssh2_transport(ssh, "timeout", -1, NULL);
10323 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
10324 struct Packet *pktin)
10326 unsigned char *in = (unsigned char *)vin;
10327 if (ssh->state == SSH_STATE_CLOSED)
10331 ssh->incoming_data_size += pktin->encrypted_len;
10332 if (!ssh->kex_in_progress &&
10333 ssh->max_data_size != 0 &&
10334 ssh->incoming_data_size > ssh->max_data_size)
10335 do_ssh2_transport(ssh, "too much data received", -1, NULL);
10339 ssh->packet_dispatch[pktin->type](ssh, pktin);
10340 else if (!ssh->protocol_initial_phase_done)
10341 do_ssh2_transport(ssh, in, inlen, pktin);
10343 do_ssh2_authconn(ssh, in, inlen, pktin);
10346 static void ssh2_bare_connection_protocol(Ssh ssh, void *vin, int inlen,
10347 struct Packet *pktin)
10349 unsigned char *in = (unsigned char *)vin;
10350 if (ssh->state == SSH_STATE_CLOSED)
10354 ssh->packet_dispatch[pktin->type](ssh, pktin);
10356 do_ssh2_authconn(ssh, in, inlen, pktin);
10359 static void ssh_cache_conf_values(Ssh ssh)
10361 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
10365 * Called to set up the connection.
10367 * Returns an error message, or NULL on success.
10369 static const char *ssh_init(void *frontend_handle, void **backend_handle,
10370 Conf *conf, char *host, int port, char **realhost,
10371 int nodelay, int keepalive)
10376 ssh = snew(struct ssh_tag);
10377 ssh->conf = conf_copy(conf);
10378 ssh_cache_conf_values(ssh);
10379 ssh->version = 0; /* when not ready yet */
10381 ssh->cipher = NULL;
10382 ssh->v1_cipher_ctx = NULL;
10383 ssh->crcda_ctx = NULL;
10384 ssh->cscipher = NULL;
10385 ssh->cs_cipher_ctx = NULL;
10386 ssh->sccipher = NULL;
10387 ssh->sc_cipher_ctx = NULL;
10389 ssh->cs_mac_ctx = NULL;
10391 ssh->sc_mac_ctx = NULL;
10392 ssh->cscomp = NULL;
10393 ssh->cs_comp_ctx = NULL;
10394 ssh->sccomp = NULL;
10395 ssh->sc_comp_ctx = NULL;
10397 ssh->kex_ctx = NULL;
10398 ssh->hostkey = NULL;
10399 ssh->hostkey_str = NULL;
10400 ssh->exitcode = -1;
10401 ssh->close_expected = FALSE;
10402 ssh->clean_exit = FALSE;
10403 ssh->state = SSH_STATE_PREPACKET;
10404 ssh->size_needed = FALSE;
10405 ssh->eof_needed = FALSE;
10407 ssh->logctx = NULL;
10408 ssh->deferred_send_data = NULL;
10409 ssh->deferred_len = 0;
10410 ssh->deferred_size = 0;
10411 ssh->fallback_cmd = 0;
10412 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
10413 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
10414 ssh->x11disp = NULL;
10415 ssh->x11auth = NULL;
10416 ssh->x11authtree = newtree234(x11_authcmp);
10417 ssh->v1_compressing = FALSE;
10418 ssh->v2_outgoing_sequence = 0;
10419 ssh->ssh1_rdpkt_crstate = 0;
10420 ssh->ssh2_rdpkt_crstate = 0;
10421 ssh->ssh2_bare_rdpkt_crstate = 0;
10422 ssh->ssh_gotdata_crstate = 0;
10423 ssh->do_ssh1_connection_crstate = 0;
10424 ssh->do_ssh_init_state = NULL;
10425 ssh->do_ssh_connection_init_state = NULL;
10426 ssh->do_ssh1_login_state = NULL;
10427 ssh->do_ssh2_transport_state = NULL;
10428 ssh->do_ssh2_authconn_state = NULL;
10431 ssh->mainchan = NULL;
10432 ssh->throttled_all = 0;
10433 ssh->v1_stdout_throttling = 0;
10435 ssh->queuelen = ssh->queuesize = 0;
10436 ssh->queueing = FALSE;
10437 ssh->qhead = ssh->qtail = NULL;
10438 ssh->deferred_rekey_reason = NULL;
10439 bufchain_init(&ssh->queued_incoming_data);
10440 ssh->frozen = FALSE;
10441 ssh->username = NULL;
10442 ssh->sent_console_eof = FALSE;
10443 ssh->got_pty = FALSE;
10444 ssh->bare_connection = FALSE;
10445 ssh->attempting_connshare = FALSE;
10447 *backend_handle = ssh;
10450 if (crypto_startup() == 0)
10451 return "Microsoft high encryption pack not installed!";
10454 ssh->frontend = frontend_handle;
10455 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
10456 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
10458 ssh->channels = NULL;
10459 ssh->rportfwds = NULL;
10460 ssh->portfwds = NULL;
10465 ssh->conn_throttle_count = 0;
10466 ssh->overall_bufsize = 0;
10467 ssh->fallback_cmd = 0;
10469 ssh->protocol = NULL;
10471 ssh->protocol_initial_phase_done = FALSE;
10473 ssh->pinger = NULL;
10475 ssh->incoming_data_size = ssh->outgoing_data_size =
10476 ssh->deferred_data_size = 0L;
10477 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10478 CONF_ssh_rekey_data));
10479 ssh->kex_in_progress = FALSE;
10482 ssh->gsslibs = NULL;
10485 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
10494 static void ssh_free(void *handle)
10496 Ssh ssh = (Ssh) handle;
10497 struct ssh_channel *c;
10498 struct ssh_rportfwd *pf;
10499 struct X11FakeAuth *auth;
10501 if (ssh->v1_cipher_ctx)
10502 ssh->cipher->free_context(ssh->v1_cipher_ctx);
10503 if (ssh->cs_cipher_ctx)
10504 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
10505 if (ssh->sc_cipher_ctx)
10506 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
10507 if (ssh->cs_mac_ctx)
10508 ssh->csmac->free_context(ssh->cs_mac_ctx);
10509 if (ssh->sc_mac_ctx)
10510 ssh->scmac->free_context(ssh->sc_mac_ctx);
10511 if (ssh->cs_comp_ctx) {
10513 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
10515 zlib_compress_cleanup(ssh->cs_comp_ctx);
10517 if (ssh->sc_comp_ctx) {
10519 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
10521 zlib_decompress_cleanup(ssh->sc_comp_ctx);
10524 dh_cleanup(ssh->kex_ctx);
10525 sfree(ssh->savedhost);
10527 while (ssh->queuelen-- > 0)
10528 ssh_free_packet(ssh->queue[ssh->queuelen]);
10531 while (ssh->qhead) {
10532 struct queued_handler *qh = ssh->qhead;
10533 ssh->qhead = qh->next;
10536 ssh->qhead = ssh->qtail = NULL;
10538 if (ssh->channels) {
10539 while ((c = delpos234(ssh->channels, 0)) != NULL) {
10542 if (c->u.x11.xconn != NULL)
10543 x11_close(c->u.x11.xconn);
10545 case CHAN_SOCKDATA:
10546 case CHAN_SOCKDATA_DORMANT:
10547 if (c->u.pfd.pf != NULL)
10548 pfd_close(c->u.pfd.pf);
10551 if (ssh->version == 2) {
10552 struct outstanding_channel_request *ocr, *nocr;
10553 ocr = c->v.v2.chanreq_head;
10555 ocr->handler(c, NULL, ocr->ctx);
10560 bufchain_clear(&c->v.v2.outbuffer);
10564 freetree234(ssh->channels);
10565 ssh->channels = NULL;
10568 if (ssh->connshare)
10569 sharestate_free(ssh->connshare);
10571 if (ssh->rportfwds) {
10572 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
10574 freetree234(ssh->rportfwds);
10575 ssh->rportfwds = NULL;
10577 sfree(ssh->deferred_send_data);
10579 x11_free_display(ssh->x11disp);
10580 while ((auth = delpos234(ssh->x11authtree, 0)) != NULL)
10581 x11_free_fake_auth(auth);
10582 freetree234(ssh->x11authtree);
10583 sfree(ssh->do_ssh_init_state);
10584 sfree(ssh->do_ssh1_login_state);
10585 sfree(ssh->do_ssh2_transport_state);
10586 sfree(ssh->do_ssh2_authconn_state);
10589 sfree(ssh->fullhostname);
10590 sfree(ssh->hostkey_str);
10591 if (ssh->crcda_ctx) {
10592 crcda_free_context(ssh->crcda_ctx);
10593 ssh->crcda_ctx = NULL;
10596 ssh_do_close(ssh, TRUE);
10597 expire_timer_context(ssh);
10599 pinger_free(ssh->pinger);
10600 bufchain_clear(&ssh->queued_incoming_data);
10601 sfree(ssh->username);
10602 conf_free(ssh->conf);
10605 ssh_gss_cleanup(ssh->gsslibs);
10613 * Reconfigure the SSH backend.
10615 static void ssh_reconfig(void *handle, Conf *conf)
10617 Ssh ssh = (Ssh) handle;
10618 char *rekeying = NULL, rekey_mandatory = FALSE;
10619 unsigned long old_max_data_size;
10622 pinger_reconfig(ssh->pinger, ssh->conf, conf);
10624 ssh_setup_portfwd(ssh, conf);
10626 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
10627 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
10629 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
10630 unsigned long now = GETTICKCOUNT();
10632 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
10633 rekeying = "timeout shortened";
10635 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
10639 old_max_data_size = ssh->max_data_size;
10640 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10641 CONF_ssh_rekey_data));
10642 if (old_max_data_size != ssh->max_data_size &&
10643 ssh->max_data_size != 0) {
10644 if (ssh->outgoing_data_size > ssh->max_data_size ||
10645 ssh->incoming_data_size > ssh->max_data_size)
10646 rekeying = "data limit lowered";
10649 if (conf_get_int(ssh->conf, CONF_compression) !=
10650 conf_get_int(conf, CONF_compression)) {
10651 rekeying = "compression setting changed";
10652 rekey_mandatory = TRUE;
10655 for (i = 0; i < CIPHER_MAX; i++)
10656 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
10657 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
10658 rekeying = "cipher settings changed";
10659 rekey_mandatory = TRUE;
10661 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
10662 conf_get_int(conf, CONF_ssh2_des_cbc)) {
10663 rekeying = "cipher settings changed";
10664 rekey_mandatory = TRUE;
10667 conf_free(ssh->conf);
10668 ssh->conf = conf_copy(conf);
10669 ssh_cache_conf_values(ssh);
10671 if (!ssh->bare_connection && rekeying) {
10672 if (!ssh->kex_in_progress) {
10673 do_ssh2_transport(ssh, rekeying, -1, NULL);
10674 } else if (rekey_mandatory) {
10675 ssh->deferred_rekey_reason = rekeying;
10681 * Called to send data down the SSH connection.
10683 static int ssh_send(void *handle, char *buf, int len)
10685 Ssh ssh = (Ssh) handle;
10687 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10690 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
10692 return ssh_sendbuffer(ssh);
10696 * Called to query the current amount of buffered stdin data.
10698 static int ssh_sendbuffer(void *handle)
10700 Ssh ssh = (Ssh) handle;
10701 int override_value;
10703 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10707 * If the SSH socket itself has backed up, add the total backup
10708 * size on that to any individual buffer on the stdin channel.
10710 override_value = 0;
10711 if (ssh->throttled_all)
10712 override_value = ssh->overall_bufsize;
10714 if (ssh->version == 1) {
10715 return override_value;
10716 } else if (ssh->version == 2) {
10717 if (!ssh->mainchan)
10718 return override_value;
10720 return (override_value +
10721 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
10728 * Called to set the size of the window from SSH's POV.
10730 static void ssh_size(void *handle, int width, int height)
10732 Ssh ssh = (Ssh) handle;
10733 struct Packet *pktout;
10735 ssh->term_width = width;
10736 ssh->term_height = height;
10738 switch (ssh->state) {
10739 case SSH_STATE_BEFORE_SIZE:
10740 case SSH_STATE_PREPACKET:
10741 case SSH_STATE_CLOSED:
10742 break; /* do nothing */
10743 case SSH_STATE_INTERMED:
10744 ssh->size_needed = TRUE; /* buffer for later */
10746 case SSH_STATE_SESSION:
10747 if (!conf_get_int(ssh->conf, CONF_nopty)) {
10748 if (ssh->version == 1) {
10749 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
10750 PKT_INT, ssh->term_height,
10751 PKT_INT, ssh->term_width,
10752 PKT_INT, 0, PKT_INT, 0, PKT_END);
10753 } else if (ssh->mainchan) {
10754 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
10756 ssh2_pkt_adduint32(pktout, ssh->term_width);
10757 ssh2_pkt_adduint32(pktout, ssh->term_height);
10758 ssh2_pkt_adduint32(pktout, 0);
10759 ssh2_pkt_adduint32(pktout, 0);
10760 ssh2_pkt_send(ssh, pktout);
10768 * Return a list of the special codes that make sense in this
10771 static const struct telnet_special *ssh_get_specials(void *handle)
10773 static const struct telnet_special ssh1_ignore_special[] = {
10774 {"IGNORE message", TS_NOP}
10776 static const struct telnet_special ssh2_ignore_special[] = {
10777 {"IGNORE message", TS_NOP},
10779 static const struct telnet_special ssh2_rekey_special[] = {
10780 {"Repeat key exchange", TS_REKEY},
10782 static const struct telnet_special ssh2_session_specials[] = {
10785 /* These are the signal names defined by RFC 4254.
10786 * They include all the ISO C signals, but are a subset of the POSIX
10787 * required signals. */
10788 {"SIGINT (Interrupt)", TS_SIGINT},
10789 {"SIGTERM (Terminate)", TS_SIGTERM},
10790 {"SIGKILL (Kill)", TS_SIGKILL},
10791 {"SIGQUIT (Quit)", TS_SIGQUIT},
10792 {"SIGHUP (Hangup)", TS_SIGHUP},
10793 {"More signals", TS_SUBMENU},
10794 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
10795 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
10796 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
10797 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
10798 {NULL, TS_EXITMENU}
10800 static const struct telnet_special specials_end[] = {
10801 {NULL, TS_EXITMENU}
10803 /* XXX review this length for any changes: */
10804 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
10805 lenof(ssh2_rekey_special) +
10806 lenof(ssh2_session_specials) +
10807 lenof(specials_end)];
10808 Ssh ssh = (Ssh) handle;
10810 #define ADD_SPECIALS(name) \
10812 assert((i + lenof(name)) <= lenof(ssh_specials)); \
10813 memcpy(&ssh_specials[i], name, sizeof name); \
10814 i += lenof(name); \
10817 if (ssh->version == 1) {
10818 /* Don't bother offering IGNORE if we've decided the remote
10819 * won't cope with it, since we wouldn't bother sending it if
10821 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
10822 ADD_SPECIALS(ssh1_ignore_special);
10823 } else if (ssh->version == 2) {
10824 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
10825 ADD_SPECIALS(ssh2_ignore_special);
10826 if (!(ssh->remote_bugs & BUG_SSH2_REKEY) && !ssh->bare_connection)
10827 ADD_SPECIALS(ssh2_rekey_special);
10829 ADD_SPECIALS(ssh2_session_specials);
10830 } /* else we're not ready yet */
10833 ADD_SPECIALS(specials_end);
10834 return ssh_specials;
10838 #undef ADD_SPECIALS
10842 * Send special codes. TS_EOF is useful for `plink', so you
10843 * can send an EOF and collect resulting output (e.g. `plink
10846 static void ssh_special(void *handle, Telnet_Special code)
10848 Ssh ssh = (Ssh) handle;
10849 struct Packet *pktout;
10851 if (code == TS_EOF) {
10852 if (ssh->state != SSH_STATE_SESSION) {
10854 * Buffer the EOF in case we are pre-SESSION, so we can
10855 * send it as soon as we reach SESSION.
10857 if (code == TS_EOF)
10858 ssh->eof_needed = TRUE;
10861 if (ssh->version == 1) {
10862 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
10863 } else if (ssh->mainchan) {
10864 sshfwd_write_eof(ssh->mainchan);
10865 ssh->send_ok = 0; /* now stop trying to read from stdin */
10867 logevent("Sent EOF message");
10868 } else if (code == TS_PING || code == TS_NOP) {
10869 if (ssh->state == SSH_STATE_CLOSED
10870 || ssh->state == SSH_STATE_PREPACKET) return;
10871 if (ssh->version == 1) {
10872 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
10873 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
10875 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
10876 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
10877 ssh2_pkt_addstring_start(pktout);
10878 ssh2_pkt_send_noqueue(ssh, pktout);
10881 } else if (code == TS_REKEY) {
10882 if (!ssh->kex_in_progress && !ssh->bare_connection &&
10883 ssh->version == 2) {
10884 do_ssh2_transport(ssh, "at user request", -1, NULL);
10886 } else if (code == TS_BRK) {
10887 if (ssh->state == SSH_STATE_CLOSED
10888 || ssh->state == SSH_STATE_PREPACKET) return;
10889 if (ssh->version == 1) {
10890 logevent("Unable to send BREAK signal in SSH-1");
10891 } else if (ssh->mainchan) {
10892 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
10893 ssh2_pkt_adduint32(pktout, 0); /* default break length */
10894 ssh2_pkt_send(ssh, pktout);
10897 /* Is is a POSIX signal? */
10898 char *signame = NULL;
10899 if (code == TS_SIGABRT) signame = "ABRT";
10900 if (code == TS_SIGALRM) signame = "ALRM";
10901 if (code == TS_SIGFPE) signame = "FPE";
10902 if (code == TS_SIGHUP) signame = "HUP";
10903 if (code == TS_SIGILL) signame = "ILL";
10904 if (code == TS_SIGINT) signame = "INT";
10905 if (code == TS_SIGKILL) signame = "KILL";
10906 if (code == TS_SIGPIPE) signame = "PIPE";
10907 if (code == TS_SIGQUIT) signame = "QUIT";
10908 if (code == TS_SIGSEGV) signame = "SEGV";
10909 if (code == TS_SIGTERM) signame = "TERM";
10910 if (code == TS_SIGUSR1) signame = "USR1";
10911 if (code == TS_SIGUSR2) signame = "USR2";
10912 /* The SSH-2 protocol does in principle support arbitrary named
10913 * signals, including signame@domain, but we don't support those. */
10915 /* It's a signal. */
10916 if (ssh->version == 2 && ssh->mainchan) {
10917 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
10918 ssh2_pkt_addstring(pktout, signame);
10919 ssh2_pkt_send(ssh, pktout);
10920 logeventf(ssh, "Sent signal SIG%s", signame);
10923 /* Never heard of it. Do nothing */
10928 void *new_sock_channel(void *handle, struct PortForwarding *pf)
10930 Ssh ssh = (Ssh) handle;
10931 struct ssh_channel *c;
10932 c = snew(struct ssh_channel);
10935 ssh2_channel_init(c);
10936 c->halfopen = TRUE;
10937 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
10939 add234(ssh->channels, c);
10943 unsigned ssh_alloc_sharing_channel(Ssh ssh, void *sharing_ctx)
10945 struct ssh_channel *c;
10946 c = snew(struct ssh_channel);
10949 ssh2_channel_init(c);
10950 c->type = CHAN_SHARING;
10951 c->u.sharing.ctx = sharing_ctx;
10952 add234(ssh->channels, c);
10956 void ssh_delete_sharing_channel(Ssh ssh, unsigned localid)
10958 struct ssh_channel *c;
10960 c = find234(ssh->channels, &localid, ssh_channelfind);
10962 ssh_channel_destroy(c);
10965 void ssh_send_packet_from_downstream(Ssh ssh, unsigned id, int type,
10966 const void *data, int datalen,
10967 const char *additional_log_text)
10969 struct Packet *pkt;
10971 pkt = ssh2_pkt_init(type);
10972 pkt->downstream_id = id;
10973 pkt->additional_log_text = additional_log_text;
10974 ssh2_pkt_adddata(pkt, data, datalen);
10975 ssh2_pkt_send(ssh, pkt);
10979 * This is called when stdout/stderr (the entity to which
10980 * from_backend sends data) manages to clear some backlog.
10982 static void ssh_unthrottle(void *handle, int bufsize)
10984 Ssh ssh = (Ssh) handle;
10987 if (ssh->version == 1) {
10988 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
10989 ssh->v1_stdout_throttling = 0;
10990 ssh_throttle_conn(ssh, -1);
10993 if (ssh->mainchan) {
10994 ssh2_set_window(ssh->mainchan,
10995 bufsize < ssh->mainchan->v.v2.locmaxwin ?
10996 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
10997 if (ssh_is_simple(ssh))
11000 buflimit = ssh->mainchan->v.v2.locmaxwin;
11001 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
11002 ssh->mainchan->throttling_conn = 0;
11003 ssh_throttle_conn(ssh, -1);
11009 * Now process any SSH connection data that was stashed in our
11010 * queue while we were frozen.
11012 ssh_process_queued_incoming_data(ssh);
11015 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
11017 struct ssh_channel *c = (struct ssh_channel *)channel;
11019 struct Packet *pktout;
11021 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
11023 if (ssh->version == 1) {
11024 send_packet(ssh, SSH1_MSG_PORT_OPEN,
11025 PKT_INT, c->localid,
11028 /* PKT_STR, <org:orgport>, */
11031 pktout = ssh2_chanopen_init(c, "direct-tcpip");
11033 char *trimmed_host = host_strduptrim(hostname);
11034 ssh2_pkt_addstring(pktout, trimmed_host);
11035 sfree(trimmed_host);
11037 ssh2_pkt_adduint32(pktout, port);
11039 * We make up values for the originator data; partly it's
11040 * too much hassle to keep track, and partly I'm not
11041 * convinced the server should be told details like that
11042 * about my local network configuration.
11043 * The "originator IP address" is syntactically a numeric
11044 * IP address, and some servers (e.g., Tectia) get upset
11045 * if it doesn't match this syntax.
11047 ssh2_pkt_addstring(pktout, "0.0.0.0");
11048 ssh2_pkt_adduint32(pktout, 0);
11049 ssh2_pkt_send(ssh, pktout);
11053 static int ssh_connected(void *handle)
11055 Ssh ssh = (Ssh) handle;
11056 return ssh->s != NULL;
11059 static int ssh_sendok(void *handle)
11061 Ssh ssh = (Ssh) handle;
11062 return ssh->send_ok;
11065 static int ssh_ldisc(void *handle, int option)
11067 Ssh ssh = (Ssh) handle;
11068 if (option == LD_ECHO)
11069 return ssh->echoing;
11070 if (option == LD_EDIT)
11071 return ssh->editing;
11075 static void ssh_provide_ldisc(void *handle, void *ldisc)
11077 Ssh ssh = (Ssh) handle;
11078 ssh->ldisc = ldisc;
11081 static void ssh_provide_logctx(void *handle, void *logctx)
11083 Ssh ssh = (Ssh) handle;
11084 ssh->logctx = logctx;
11087 static int ssh_return_exitcode(void *handle)
11089 Ssh ssh = (Ssh) handle;
11090 if (ssh->s != NULL)
11093 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
11097 * cfg_info for SSH is the currently running version of the
11098 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
11100 static int ssh_cfg_info(void *handle)
11102 Ssh ssh = (Ssh) handle;
11103 return ssh->version;
11107 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
11108 * that fails. This variable is the means by which scp.c can reach
11109 * into the SSH code and find out which one it got.
11111 extern int ssh_fallback_cmd(void *handle)
11113 Ssh ssh = (Ssh) handle;
11114 return ssh->fallback_cmd;
11117 Backend ssh_backend = {
11127 ssh_return_exitcode,
11131 ssh_provide_logctx,