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
3424 colon = host_strrchr(tmphost, ':');
3428 ssh->savedport = atoi(colon);
3431 ssh->savedhost = host_strduptrim(tmphost);
3434 ssh->savedhost = host_strduptrim(host);
3436 port = 22; /* default ssh port */
3437 ssh->savedport = port;
3440 ssh->fn = &fn_table; /* make 'ssh' usable as a Plug */
3443 * Try connection-sharing, in case that means we don't open a
3444 * socket after all. ssh_connection_sharing_init will connect to a
3445 * previously established upstream if it can, and failing that,
3446 * establish a listening socket for _us_ to be the upstream. In
3447 * the latter case it will return NULL just as if it had done
3448 * nothing, because here we only need to care if we're a
3449 * downstream and need to do our connection setup differently.
3451 ssh->connshare = NULL;
3452 ssh->attempting_connshare = TRUE; /* affects socket logging behaviour */
3453 ssh->s = ssh_connection_sharing_init(ssh->savedhost, ssh->savedport,
3454 ssh->conf, ssh, &ssh->connshare);
3455 ssh->attempting_connshare = FALSE;
3456 if (ssh->s != NULL) {
3458 * We are a downstream.
3460 ssh->bare_connection = TRUE;
3461 ssh->do_ssh_init = do_ssh_connection_init;
3462 ssh->fullhostname = NULL;
3463 *realhost = dupstr(host); /* best we can do */
3466 * We're not a downstream, so open a normal socket.
3468 ssh->do_ssh_init = do_ssh_init;
3473 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
3474 logeventf(ssh, "Looking up host \"%s\"%s", host,
3475 (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
3476 (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
3477 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily);
3478 if ((err = sk_addr_error(addr)) != NULL) {
3482 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3484 ssh->s = new_connection(addr, *realhost, port,
3485 0, 1, nodelay, keepalive,
3486 (Plug) ssh, ssh->conf);
3487 if ((err = sk_socket_error(ssh->s)) != NULL) {
3489 notify_remote_exit(ssh->frontend);
3495 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3496 * send the version string too.
3498 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3501 if (sshprot == 3 && !ssh->bare_connection) {
3503 ssh_send_verstring(ssh, "SSH-", NULL);
3507 * loghost, if configured, overrides realhost.
3511 *realhost = dupstr(loghost);
3518 * Throttle or unthrottle the SSH connection.
3520 static void ssh_throttle_conn(Ssh ssh, int adjust)
3522 int old_count = ssh->conn_throttle_count;
3523 ssh->conn_throttle_count += adjust;
3524 assert(ssh->conn_throttle_count >= 0);
3525 if (ssh->conn_throttle_count && !old_count) {
3526 ssh_set_frozen(ssh, 1);
3527 } else if (!ssh->conn_throttle_count && old_count) {
3528 ssh_set_frozen(ssh, 0);
3533 * Throttle or unthrottle _all_ local data streams (for when sends
3534 * on the SSH connection itself back up).
3536 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3539 struct ssh_channel *c;
3541 if (enable == ssh->throttled_all)
3543 ssh->throttled_all = enable;
3544 ssh->overall_bufsize = bufsize;
3547 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3549 case CHAN_MAINSESSION:
3551 * This is treated separately, outside the switch.
3555 x11_override_throttle(c->u.x11.xconn, enable);
3558 /* Agent channels require no buffer management. */
3561 pfd_override_throttle(c->u.pfd.pf, enable);
3567 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3569 Ssh ssh = (Ssh) sshv;
3571 ssh->agent_response = reply;
3572 ssh->agent_response_len = replylen;
3574 if (ssh->version == 1)
3575 do_ssh1_login(ssh, NULL, -1, NULL);
3577 do_ssh2_authconn(ssh, NULL, -1, NULL);
3580 static void ssh_dialog_callback(void *sshv, int ret)
3582 Ssh ssh = (Ssh) sshv;
3584 ssh->user_response = ret;
3586 if (ssh->version == 1)
3587 do_ssh1_login(ssh, NULL, -1, NULL);
3589 do_ssh2_transport(ssh, NULL, -1, NULL);
3592 * This may have unfrozen the SSH connection, so do a
3595 ssh_process_queued_incoming_data(ssh);
3598 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3600 struct ssh_channel *c = (struct ssh_channel *)cv;
3602 void *sentreply = reply;
3604 c->u.a.outstanding_requests--;
3606 /* Fake SSH_AGENT_FAILURE. */
3607 sentreply = "\0\0\0\1\5";
3610 if (ssh->version == 2) {
3611 ssh2_add_channel_data(c, sentreply, replylen);
3614 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3615 PKT_INT, c->remoteid,
3617 PKT_DATA, sentreply, replylen,
3623 * If we've already seen an incoming EOF but haven't sent an
3624 * outgoing one, this may be the moment to send it.
3626 if (c->u.a.outstanding_requests == 0 && (c->closes & CLOSES_RCVD_EOF))
3627 sshfwd_write_eof(c);
3631 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3632 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3633 * => log `wire_reason'.
3635 static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
3636 int code, int clean_exit)
3640 client_reason = wire_reason;
3642 error = dupprintf("Disconnected: %s", client_reason);
3644 error = dupstr("Disconnected");
3646 if (ssh->version == 1) {
3647 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3649 } else if (ssh->version == 2) {
3650 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3651 ssh2_pkt_adduint32(pktout, code);
3652 ssh2_pkt_addstring(pktout, wire_reason);
3653 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3654 ssh2_pkt_send_noqueue(ssh, pktout);
3657 ssh->close_expected = TRUE;
3658 ssh->clean_exit = clean_exit;
3659 ssh_closing((Plug)ssh, error, 0, 0);
3664 * Handle the key exchange and user authentication phases.
3666 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
3667 struct Packet *pktin)
3670 unsigned char cookie[8], *ptr;
3671 struct MD5Context md5c;
3672 struct do_ssh1_login_state {
3675 unsigned char *rsabuf, *keystr1, *keystr2;
3676 unsigned long supported_ciphers_mask, supported_auths_mask;
3677 int tried_publickey, tried_agent;
3678 int tis_auth_refused, ccard_auth_refused;
3679 unsigned char session_id[16];
3681 void *publickey_blob;
3682 int publickey_bloblen;
3683 char *publickey_comment;
3684 int publickey_encrypted;
3685 prompts_t *cur_prompt;
3688 unsigned char request[5], *response, *p;
3698 struct RSAKey servkey, hostkey;
3700 crState(do_ssh1_login_state);
3707 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
3708 bombout(("Public key packet not received"));
3712 logevent("Received public keys");
3714 ptr = ssh_pkt_getdata(pktin, 8);
3716 bombout(("SSH-1 public key packet stopped before random cookie"));
3719 memcpy(cookie, ptr, 8);
3721 if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) ||
3722 !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) {
3723 bombout(("Failed to read SSH-1 public keys from public key packet"));
3728 * Log the host key fingerprint.
3732 logevent("Host key fingerprint is:");
3733 strcpy(logmsg, " ");
3734 s->hostkey.comment = NULL;
3735 rsa_fingerprint(logmsg + strlen(logmsg),
3736 sizeof(logmsg) - strlen(logmsg), &s->hostkey);
3740 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3741 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3742 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
3743 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
3744 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
3746 ssh->v1_local_protoflags =
3747 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3748 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
3751 MD5Update(&md5c, s->keystr2, s->hostkey.bytes);
3752 MD5Update(&md5c, s->keystr1, s->servkey.bytes);
3753 MD5Update(&md5c, cookie, 8);
3754 MD5Final(s->session_id, &md5c);
3756 for (i = 0; i < 32; i++)
3757 ssh->session_key[i] = random_byte();
3760 * Verify that the `bits' and `bytes' parameters match.
3762 if (s->hostkey.bits > s->hostkey.bytes * 8 ||
3763 s->servkey.bits > s->servkey.bytes * 8) {
3764 bombout(("SSH-1 public keys were badly formatted"));
3768 s->len = (s->hostkey.bytes > s->servkey.bytes ?
3769 s->hostkey.bytes : s->servkey.bytes);
3771 s->rsabuf = snewn(s->len, unsigned char);
3774 * Verify the host key.
3778 * First format the key into a string.
3780 int len = rsastr_len(&s->hostkey);
3781 char fingerprint[100];
3782 char *keystr = snewn(len, char);
3783 rsastr_fmt(keystr, &s->hostkey);
3784 rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey);
3786 ssh_set_frozen(ssh, 1);
3787 s->dlgret = verify_ssh_host_key(ssh->frontend,
3788 ssh->savedhost, ssh->savedport,
3789 "rsa", keystr, fingerprint,
3790 ssh_dialog_callback, ssh);
3792 if (s->dlgret < 0) {
3796 bombout(("Unexpected data from server while waiting"
3797 " for user host key response"));
3800 } while (pktin || inlen > 0);
3801 s->dlgret = ssh->user_response;
3803 ssh_set_frozen(ssh, 0);
3805 if (s->dlgret == 0) {
3806 ssh_disconnect(ssh, "User aborted at host key verification",
3812 for (i = 0; i < 32; i++) {
3813 s->rsabuf[i] = ssh->session_key[i];
3815 s->rsabuf[i] ^= s->session_id[i];
3818 if (s->hostkey.bytes > s->servkey.bytes) {
3819 ret = rsaencrypt(s->rsabuf, 32, &s->servkey);
3821 ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey);
3823 ret = rsaencrypt(s->rsabuf, 32, &s->hostkey);
3825 ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey);
3828 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3832 logevent("Encrypted session key");
3835 int cipher_chosen = 0, warn = 0;
3836 char *cipher_string = NULL;
3838 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
3839 int next_cipher = conf_get_int_int(ssh->conf,
3840 CONF_ssh_cipherlist, i);
3841 if (next_cipher == CIPHER_WARN) {
3842 /* If/when we choose a cipher, warn about it */
3844 } else if (next_cipher == CIPHER_AES) {
3845 /* XXX Probably don't need to mention this. */
3846 logevent("AES not supported in SSH-1, skipping");
3848 switch (next_cipher) {
3849 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
3850 cipher_string = "3DES"; break;
3851 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
3852 cipher_string = "Blowfish"; break;
3853 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
3854 cipher_string = "single-DES"; break;
3856 if (s->supported_ciphers_mask & (1 << s->cipher_type))
3860 if (!cipher_chosen) {
3861 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
3862 bombout(("Server violates SSH-1 protocol by not "
3863 "supporting 3DES encryption"));
3865 /* shouldn't happen */
3866 bombout(("No supported ciphers found"));
3870 /* Warn about chosen cipher if necessary. */
3872 ssh_set_frozen(ssh, 1);
3873 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3874 ssh_dialog_callback, ssh);
3875 if (s->dlgret < 0) {
3879 bombout(("Unexpected data from server while waiting"
3880 " for user response"));
3883 } while (pktin || inlen > 0);
3884 s->dlgret = ssh->user_response;
3886 ssh_set_frozen(ssh, 0);
3887 if (s->dlgret == 0) {
3888 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3895 switch (s->cipher_type) {
3896 case SSH_CIPHER_3DES:
3897 logevent("Using 3DES encryption");
3899 case SSH_CIPHER_DES:
3900 logevent("Using single-DES encryption");
3902 case SSH_CIPHER_BLOWFISH:
3903 logevent("Using Blowfish encryption");
3907 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3908 PKT_CHAR, s->cipher_type,
3909 PKT_DATA, cookie, 8,
3910 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3911 PKT_DATA, s->rsabuf, s->len,
3912 PKT_INT, ssh->v1_local_protoflags, PKT_END);
3914 logevent("Trying to enable encryption...");
3918 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3919 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3921 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3922 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
3923 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
3925 ssh->crcda_ctx = crcda_make_context();
3926 logevent("Installing CRC compensation attack detector");
3928 if (s->servkey.modulus) {
3929 sfree(s->servkey.modulus);
3930 s->servkey.modulus = NULL;
3932 if (s->servkey.exponent) {
3933 sfree(s->servkey.exponent);
3934 s->servkey.exponent = NULL;
3936 if (s->hostkey.modulus) {
3937 sfree(s->hostkey.modulus);
3938 s->hostkey.modulus = NULL;
3940 if (s->hostkey.exponent) {
3941 sfree(s->hostkey.exponent);
3942 s->hostkey.exponent = NULL;
3946 if (pktin->type != SSH1_SMSG_SUCCESS) {
3947 bombout(("Encryption not successfully enabled"));
3951 logevent("Successfully started encryption");
3953 fflush(stdout); /* FIXME eh? */
3955 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
3956 int ret; /* need not be kept over crReturn */
3957 s->cur_prompt = new_prompts(ssh->frontend);
3958 s->cur_prompt->to_server = TRUE;
3959 s->cur_prompt->name = dupstr("SSH login name");
3960 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
3961 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3964 crWaitUntil(!pktin);
3965 ret = get_userpass_input(s->cur_prompt, in, inlen);
3970 * Failed to get a username. Terminate.
3972 free_prompts(s->cur_prompt);
3973 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
3976 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
3977 free_prompts(s->cur_prompt);
3980 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
3982 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
3984 if (flags & FLAG_INTERACTIVE &&
3985 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3986 c_write_str(ssh, userlog);
3987 c_write_str(ssh, "\r\n");
3995 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
3996 /* We must not attempt PK auth. Pretend we've already tried it. */
3997 s->tried_publickey = s->tried_agent = 1;
3999 s->tried_publickey = s->tried_agent = 0;
4001 s->tis_auth_refused = s->ccard_auth_refused = 0;
4003 * Load the public half of any configured keyfile for later use.
4005 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4006 if (!filename_is_null(s->keyfile)) {
4008 logeventf(ssh, "Reading private key file \"%.150s\"",
4009 filename_to_str(s->keyfile));
4010 keytype = key_type(s->keyfile);
4011 if (keytype == SSH_KEYTYPE_SSH1) {
4013 if (rsakey_pubblob(s->keyfile,
4014 &s->publickey_blob, &s->publickey_bloblen,
4015 &s->publickey_comment, &error)) {
4016 s->publickey_encrypted = rsakey_encrypted(s->keyfile,
4020 logeventf(ssh, "Unable to load private key (%s)", error);
4021 msgbuf = dupprintf("Unable to load private key file "
4022 "\"%.150s\" (%s)\r\n",
4023 filename_to_str(s->keyfile),
4025 c_write_str(ssh, msgbuf);
4027 s->publickey_blob = NULL;
4031 logeventf(ssh, "Unable to use this key file (%s)",
4032 key_type_to_str(keytype));
4033 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4035 filename_to_str(s->keyfile),
4036 key_type_to_str(keytype));
4037 c_write_str(ssh, msgbuf);
4039 s->publickey_blob = NULL;
4042 s->publickey_blob = NULL;
4044 while (pktin->type == SSH1_SMSG_FAILURE) {
4045 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
4047 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
4049 * Attempt RSA authentication using Pageant.
4055 logevent("Pageant is running. Requesting keys.");
4057 /* Request the keys held by the agent. */
4058 PUT_32BIT(s->request, 1);
4059 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
4060 if (!agent_query(s->request, 5, &r, &s->responselen,
4061 ssh_agent_callback, ssh)) {
4065 bombout(("Unexpected data from server while waiting"
4066 " for agent response"));
4069 } while (pktin || inlen > 0);
4070 r = ssh->agent_response;
4071 s->responselen = ssh->agent_response_len;
4073 s->response = (unsigned char *) r;
4074 if (s->response && s->responselen >= 5 &&
4075 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
4076 s->p = s->response + 5;
4077 s->nkeys = toint(GET_32BIT(s->p));
4079 logeventf(ssh, "Pageant reported negative key count %d",
4084 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
4085 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4086 unsigned char *pkblob = s->p;
4090 do { /* do while (0) to make breaking easy */
4091 n = ssh1_read_bignum
4092 (s->p, toint(s->responselen-(s->p-s->response)),
4097 n = ssh1_read_bignum
4098 (s->p, toint(s->responselen-(s->p-s->response)),
4103 if (s->responselen - (s->p-s->response) < 4)
4105 s->commentlen = toint(GET_32BIT(s->p));
4107 if (s->commentlen < 0 ||
4108 toint(s->responselen - (s->p-s->response)) <
4111 s->commentp = (char *)s->p;
4112 s->p += s->commentlen;
4116 logevent("Pageant key list packet was truncated");
4120 if (s->publickey_blob) {
4121 if (!memcmp(pkblob, s->publickey_blob,
4122 s->publickey_bloblen)) {
4123 logeventf(ssh, "Pageant key #%d matches "
4124 "configured key file", s->keyi);
4125 s->tried_publickey = 1;
4127 /* Skip non-configured key */
4130 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
4131 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4132 PKT_BIGNUM, s->key.modulus, PKT_END);
4134 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4135 logevent("Key refused");
4138 logevent("Received RSA challenge");
4139 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4140 bombout(("Server's RSA challenge was badly formatted"));
4145 char *agentreq, *q, *ret;
4148 len = 1 + 4; /* message type, bit count */
4149 len += ssh1_bignum_length(s->key.exponent);
4150 len += ssh1_bignum_length(s->key.modulus);
4151 len += ssh1_bignum_length(s->challenge);
4152 len += 16; /* session id */
4153 len += 4; /* response format */
4154 agentreq = snewn(4 + len, char);
4155 PUT_32BIT(agentreq, len);
4157 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
4158 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
4160 q += ssh1_write_bignum(q, s->key.exponent);
4161 q += ssh1_write_bignum(q, s->key.modulus);
4162 q += ssh1_write_bignum(q, s->challenge);
4163 memcpy(q, s->session_id, 16);
4165 PUT_32BIT(q, 1); /* response format */
4166 if (!agent_query(agentreq, len + 4, &vret, &retlen,
4167 ssh_agent_callback, ssh)) {
4172 bombout(("Unexpected data from server"
4173 " while waiting for agent"
4177 } while (pktin || inlen > 0);
4178 vret = ssh->agent_response;
4179 retlen = ssh->agent_response_len;
4184 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
4185 logevent("Sending Pageant's response");
4186 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4187 PKT_DATA, ret + 5, 16,
4191 if (pktin->type == SSH1_SMSG_SUCCESS) {
4193 ("Pageant's response accepted");
4194 if (flags & FLAG_VERBOSE) {
4195 c_write_str(ssh, "Authenticated using"
4197 c_write(ssh, s->commentp,
4199 c_write_str(ssh, "\" from agent\r\n");
4204 ("Pageant's response not accepted");
4207 ("Pageant failed to answer challenge");
4211 logevent("No reply received from Pageant");
4214 freebn(s->key.exponent);
4215 freebn(s->key.modulus);
4216 freebn(s->challenge);
4221 if (s->publickey_blob && !s->tried_publickey)
4222 logevent("Configured key file not in Pageant");
4224 logevent("Failed to get reply from Pageant");
4229 if (s->publickey_blob && !s->tried_publickey) {
4231 * Try public key authentication with the specified
4234 int got_passphrase; /* need not be kept over crReturn */
4235 if (flags & FLAG_VERBOSE)
4236 c_write_str(ssh, "Trying public key authentication.\r\n");
4237 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4238 logeventf(ssh, "Trying public key \"%s\"",
4239 filename_to_str(s->keyfile));
4240 s->tried_publickey = 1;
4241 got_passphrase = FALSE;
4242 while (!got_passphrase) {
4244 * Get a passphrase, if necessary.
4246 char *passphrase = NULL; /* only written after crReturn */
4248 if (!s->publickey_encrypted) {
4249 if (flags & FLAG_VERBOSE)
4250 c_write_str(ssh, "No passphrase required.\r\n");
4253 int ret; /* need not be kept over crReturn */
4254 s->cur_prompt = new_prompts(ssh->frontend);
4255 s->cur_prompt->to_server = FALSE;
4256 s->cur_prompt->name = dupstr("SSH key passphrase");
4257 add_prompt(s->cur_prompt,
4258 dupprintf("Passphrase for key \"%.100s\": ",
4259 s->publickey_comment), FALSE);
4260 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4263 crWaitUntil(!pktin);
4264 ret = get_userpass_input(s->cur_prompt, in, inlen);
4268 /* Failed to get a passphrase. Terminate. */
4269 free_prompts(s->cur_prompt);
4270 ssh_disconnect(ssh, NULL, "Unable to authenticate",
4274 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
4275 free_prompts(s->cur_prompt);
4278 * Try decrypting key with passphrase.
4280 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4281 ret = loadrsakey(s->keyfile, &s->key, passphrase,
4284 smemclr(passphrase, strlen(passphrase));
4288 /* Correct passphrase. */
4289 got_passphrase = TRUE;
4290 } else if (ret == 0) {
4291 c_write_str(ssh, "Couldn't load private key from ");
4292 c_write_str(ssh, filename_to_str(s->keyfile));
4293 c_write_str(ssh, " (");
4294 c_write_str(ssh, error);
4295 c_write_str(ssh, ").\r\n");
4296 got_passphrase = FALSE;
4297 break; /* go and try something else */
4298 } else if (ret == -1) {
4299 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
4300 got_passphrase = FALSE;
4303 assert(0 && "unexpected return from loadrsakey()");
4304 got_passphrase = FALSE; /* placate optimisers */
4308 if (got_passphrase) {
4311 * Send a public key attempt.
4313 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4314 PKT_BIGNUM, s->key.modulus, PKT_END);
4317 if (pktin->type == SSH1_SMSG_FAILURE) {
4318 c_write_str(ssh, "Server refused our public key.\r\n");
4319 continue; /* go and try something else */
4321 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4322 bombout(("Bizarre response to offer of public key"));
4328 unsigned char buffer[32];
4329 Bignum challenge, response;
4331 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4332 bombout(("Server's RSA challenge was badly formatted"));
4335 response = rsadecrypt(challenge, &s->key);
4336 freebn(s->key.private_exponent);/* burn the evidence */
4338 for (i = 0; i < 32; i++) {
4339 buffer[i] = bignum_byte(response, 31 - i);
4343 MD5Update(&md5c, buffer, 32);
4344 MD5Update(&md5c, s->session_id, 16);
4345 MD5Final(buffer, &md5c);
4347 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4348 PKT_DATA, buffer, 16, PKT_END);
4355 if (pktin->type == SSH1_SMSG_FAILURE) {
4356 if (flags & FLAG_VERBOSE)
4357 c_write_str(ssh, "Failed to authenticate with"
4358 " our public key.\r\n");
4359 continue; /* go and try something else */
4360 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4361 bombout(("Bizarre response to RSA authentication response"));
4365 break; /* we're through! */
4371 * Otherwise, try various forms of password-like authentication.
4373 s->cur_prompt = new_prompts(ssh->frontend);
4375 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4376 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
4377 !s->tis_auth_refused) {
4378 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
4379 logevent("Requested TIS authentication");
4380 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
4382 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
4383 logevent("TIS authentication declined");
4384 if (flags & FLAG_INTERACTIVE)
4385 c_write_str(ssh, "TIS authentication refused.\r\n");
4386 s->tis_auth_refused = 1;
4391 char *instr_suf, *prompt;
4393 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4395 bombout(("TIS challenge packet was badly formed"));
4398 logevent("Received TIS challenge");
4399 s->cur_prompt->to_server = TRUE;
4400 s->cur_prompt->name = dupstr("SSH TIS authentication");
4401 /* Prompt heuristic comes from OpenSSH */
4402 if (memchr(challenge, '\n', challengelen)) {
4403 instr_suf = dupstr("");
4404 prompt = dupprintf("%.*s", challengelen, challenge);
4406 instr_suf = dupprintf("%.*s", challengelen, challenge);
4407 prompt = dupstr("Response: ");
4409 s->cur_prompt->instruction =
4410 dupprintf("Using TIS authentication.%s%s",
4411 (*instr_suf) ? "\n" : "",
4413 s->cur_prompt->instr_reqd = TRUE;
4414 add_prompt(s->cur_prompt, prompt, FALSE);
4418 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4419 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
4420 !s->ccard_auth_refused) {
4421 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
4422 logevent("Requested CryptoCard authentication");
4423 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
4425 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
4426 logevent("CryptoCard authentication declined");
4427 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4428 s->ccard_auth_refused = 1;
4433 char *instr_suf, *prompt;
4435 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4437 bombout(("CryptoCard challenge packet was badly formed"));
4440 logevent("Received CryptoCard challenge");
4441 s->cur_prompt->to_server = TRUE;
4442 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4443 s->cur_prompt->name_reqd = FALSE;
4444 /* Prompt heuristic comes from OpenSSH */
4445 if (memchr(challenge, '\n', challengelen)) {
4446 instr_suf = dupstr("");
4447 prompt = dupprintf("%.*s", challengelen, challenge);
4449 instr_suf = dupprintf("%.*s", challengelen, challenge);
4450 prompt = dupstr("Response: ");
4452 s->cur_prompt->instruction =
4453 dupprintf("Using CryptoCard authentication.%s%s",
4454 (*instr_suf) ? "\n" : "",
4456 s->cur_prompt->instr_reqd = TRUE;
4457 add_prompt(s->cur_prompt, prompt, FALSE);
4461 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4462 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4463 bombout(("No supported authentication methods available"));
4466 s->cur_prompt->to_server = TRUE;
4467 s->cur_prompt->name = dupstr("SSH password");
4468 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4469 ssh->username, ssh->savedhost),
4474 * Show password prompt, having first obtained it via a TIS
4475 * or CryptoCard exchange if we're doing TIS or CryptoCard
4479 int ret; /* need not be kept over crReturn */
4480 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4483 crWaitUntil(!pktin);
4484 ret = get_userpass_input(s->cur_prompt, in, inlen);
4489 * Failed to get a password (for example
4490 * because one was supplied on the command line
4491 * which has already failed to work). Terminate.
4493 free_prompts(s->cur_prompt);
4494 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4499 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4501 * Defence against traffic analysis: we send a
4502 * whole bunch of packets containing strings of
4503 * different lengths. One of these strings is the
4504 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4505 * The others are all random data in
4506 * SSH1_MSG_IGNORE packets. This way a passive
4507 * listener can't tell which is the password, and
4508 * hence can't deduce the password length.
4510 * Anybody with a password length greater than 16
4511 * bytes is going to have enough entropy in their
4512 * password that a listener won't find it _that_
4513 * much help to know how long it is. So what we'll
4516 * - if password length < 16, we send 15 packets
4517 * containing string lengths 1 through 15
4519 * - otherwise, we let N be the nearest multiple
4520 * of 8 below the password length, and send 8
4521 * packets containing string lengths N through
4522 * N+7. This won't obscure the order of
4523 * magnitude of the password length, but it will
4524 * introduce a bit of extra uncertainty.
4526 * A few servers can't deal with SSH1_MSG_IGNORE, at
4527 * least in this context. For these servers, we need
4528 * an alternative defence. We make use of the fact
4529 * that the password is interpreted as a C string:
4530 * so we can append a NUL, then some random data.
4532 * A few servers can deal with neither SSH1_MSG_IGNORE
4533 * here _nor_ a padded password string.
4534 * For these servers we are left with no defences
4535 * against password length sniffing.
4537 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4538 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4540 * The server can deal with SSH1_MSG_IGNORE, so
4541 * we can use the primary defence.
4543 int bottom, top, pwlen, i;
4546 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4548 bottom = 0; /* zero length passwords are OK! :-) */
4551 bottom = pwlen & ~7;
4555 assert(pwlen >= bottom && pwlen <= top);
4557 randomstr = snewn(top + 1, char);
4559 for (i = bottom; i <= top; i++) {
4561 defer_packet(ssh, s->pwpkt_type,
4562 PKT_STR,s->cur_prompt->prompts[0]->result,
4565 for (j = 0; j < i; j++) {
4567 randomstr[j] = random_byte();
4568 } while (randomstr[j] == '\0');
4570 randomstr[i] = '\0';
4571 defer_packet(ssh, SSH1_MSG_IGNORE,
4572 PKT_STR, randomstr, PKT_END);
4575 logevent("Sending password with camouflage packets");
4576 ssh_pkt_defersend(ssh);
4579 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4581 * The server can't deal with SSH1_MSG_IGNORE
4582 * but can deal with padded passwords, so we
4583 * can use the secondary defence.
4589 len = strlen(s->cur_prompt->prompts[0]->result);
4590 if (len < sizeof(string)) {
4592 strcpy(string, s->cur_prompt->prompts[0]->result);
4593 len++; /* cover the zero byte */
4594 while (len < sizeof(string)) {
4595 string[len++] = (char) random_byte();
4598 ss = s->cur_prompt->prompts[0]->result;
4600 logevent("Sending length-padded password");
4601 send_packet(ssh, s->pwpkt_type,
4602 PKT_INT, len, PKT_DATA, ss, len,
4606 * The server is believed unable to cope with
4607 * any of our password camouflage methods.
4610 len = strlen(s->cur_prompt->prompts[0]->result);
4611 logevent("Sending unpadded password");
4612 send_packet(ssh, s->pwpkt_type,
4614 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4618 send_packet(ssh, s->pwpkt_type,
4619 PKT_STR, s->cur_prompt->prompts[0]->result,
4622 logevent("Sent password");
4623 free_prompts(s->cur_prompt);
4625 if (pktin->type == SSH1_SMSG_FAILURE) {
4626 if (flags & FLAG_VERBOSE)
4627 c_write_str(ssh, "Access denied\r\n");
4628 logevent("Authentication refused");
4629 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4630 bombout(("Strange packet received, type %d", pktin->type));
4636 if (s->publickey_blob) {
4637 sfree(s->publickey_blob);
4638 sfree(s->publickey_comment);
4641 logevent("Authentication successful");
4646 static void ssh_channel_try_eof(struct ssh_channel *c)
4649 assert(c->pending_eof); /* precondition for calling us */
4651 return; /* can't close: not even opened yet */
4652 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4653 return; /* can't send EOF: pending outgoing data */
4655 c->pending_eof = FALSE; /* we're about to send it */
4656 if (ssh->version == 1) {
4657 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4659 c->closes |= CLOSES_SENT_EOF;
4661 struct Packet *pktout;
4662 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4663 ssh2_pkt_adduint32(pktout, c->remoteid);
4664 ssh2_pkt_send(ssh, pktout);
4665 c->closes |= CLOSES_SENT_EOF;
4666 ssh2_channel_check_close(c);
4670 Conf *sshfwd_get_conf(struct ssh_channel *c)
4676 void sshfwd_write_eof(struct ssh_channel *c)
4680 if (ssh->state == SSH_STATE_CLOSED)
4683 if (c->closes & CLOSES_SENT_EOF)
4686 c->pending_eof = TRUE;
4687 ssh_channel_try_eof(c);
4690 void sshfwd_unclean_close(struct ssh_channel *c, const char *err)
4694 if (ssh->state == SSH_STATE_CLOSED)
4699 x11_close(c->u.x11.xconn);
4700 logeventf(ssh, "Forwarded X11 connection terminated due to local "
4704 case CHAN_SOCKDATA_DORMANT:
4705 pfd_close(c->u.pfd.pf);
4706 logeventf(ssh, "Forwarded port closed due to local error: %s", err);
4709 c->type = CHAN_ZOMBIE;
4710 c->pending_eof = FALSE; /* this will confuse a zombie channel */
4712 ssh2_channel_check_close(c);
4715 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
4719 if (ssh->state == SSH_STATE_CLOSED)
4722 if (ssh->version == 1) {
4723 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
4724 PKT_INT, c->remoteid,
4725 PKT_INT, len, PKT_DATA, buf, len,
4728 * In SSH-1 we can return 0 here - implying that forwarded
4729 * connections are never individually throttled - because
4730 * the only circumstance that can cause throttling will be
4731 * the whole SSH connection backing up, in which case
4732 * _everything_ will be throttled as a whole.
4736 ssh2_add_channel_data(c, buf, len);
4737 return ssh2_try_send(c);
4741 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4746 if (ssh->state == SSH_STATE_CLOSED)
4749 if (ssh->version == 1) {
4750 buflimit = SSH1_BUFFER_LIMIT;
4752 buflimit = c->v.v2.locmaxwin;
4753 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
4755 if (c->throttling_conn && bufsize <= buflimit) {
4756 c->throttling_conn = 0;
4757 ssh_throttle_conn(ssh, -1);
4761 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
4763 struct queued_handler *qh = ssh->qhead;
4767 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
4770 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
4771 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
4774 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
4775 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
4779 ssh->qhead = qh->next;
4781 if (ssh->qhead->msg1 > 0) {
4782 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4783 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
4785 if (ssh->qhead->msg2 > 0) {
4786 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4787 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
4790 ssh->qhead = ssh->qtail = NULL;
4793 qh->handler(ssh, pktin, qh->ctx);
4798 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
4799 chandler_fn_t handler, void *ctx)
4801 struct queued_handler *qh;
4803 qh = snew(struct queued_handler);
4806 qh->handler = handler;
4810 if (ssh->qtail == NULL) {
4814 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4815 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
4818 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4819 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
4822 ssh->qtail->next = qh;
4827 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
4829 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
4831 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
4832 SSH2_MSG_REQUEST_SUCCESS)) {
4833 logeventf(ssh, "Remote port forwarding from %s enabled",
4836 logeventf(ssh, "Remote port forwarding from %s refused",
4839 rpf = del234(ssh->rportfwds, pf);
4841 pf->pfrec->remote = NULL;
4846 int ssh_alloc_sharing_rportfwd(Ssh ssh, const char *shost, int sport,
4849 struct ssh_rportfwd *pf = snew(struct ssh_rportfwd);
4852 pf->share_ctx = share_ctx;
4853 pf->shost = dupstr(shost);
4855 pf->sportdesc = NULL;
4856 if (!ssh->rportfwds) {
4857 assert(ssh->version == 2);
4858 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4860 if (add234(ssh->rportfwds, pf) != pf) {
4868 static void ssh_sharing_global_request_response(Ssh ssh, struct Packet *pktin,
4871 share_got_pkt_from_server(ctx, pktin->type,
4872 pktin->body, pktin->length);
4875 void ssh_sharing_queue_global_request(Ssh ssh, void *share_ctx)
4877 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, SSH2_MSG_REQUEST_FAILURE,
4878 ssh_sharing_global_request_response, share_ctx);
4881 static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
4883 struct ssh_portfwd *epf;
4887 if (!ssh->portfwds) {
4888 ssh->portfwds = newtree234(ssh_portcmp);
4891 * Go through the existing port forwardings and tag them
4892 * with status==DESTROY. Any that we want to keep will be
4893 * re-enabled (status==KEEP) as we go through the
4894 * configuration and find out which bits are the same as
4897 struct ssh_portfwd *epf;
4899 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4900 epf->status = DESTROY;
4903 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
4905 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
4906 char *kp, *kp2, *vp, *vp2;
4907 char address_family, type;
4908 int sport,dport,sserv,dserv;
4909 char *sports, *dports, *saddr, *host;
4913 address_family = 'A';
4915 if (*kp == 'A' || *kp == '4' || *kp == '6')
4916 address_family = *kp++;
4917 if (*kp == 'L' || *kp == 'R')
4920 if ((kp2 = host_strchr(kp, ':')) != NULL) {
4922 * There's a colon in the middle of the source port
4923 * string, which means that the part before it is
4924 * actually a source address.
4926 char *saddr_tmp = dupprintf("%.*s", (int)(kp2 - kp), kp);
4927 saddr = host_strduptrim(saddr_tmp);
4934 sport = atoi(sports);
4938 sport = net_service_lookup(sports);
4940 logeventf(ssh, "Service lookup failed for source"
4941 " port \"%s\"", sports);
4945 if (type == 'L' && !strcmp(val, "D")) {
4946 /* dynamic forwarding */
4953 /* ordinary forwarding */
4955 vp2 = vp + host_strcspn(vp, ":");
4956 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
4960 dport = atoi(dports);
4964 dport = net_service_lookup(dports);
4966 logeventf(ssh, "Service lookup failed for destination"
4967 " port \"%s\"", dports);
4972 if (sport && dport) {
4973 /* Set up a description of the source port. */
4974 struct ssh_portfwd *pfrec, *epfrec;
4976 pfrec = snew(struct ssh_portfwd);
4978 pfrec->saddr = saddr;
4979 pfrec->sserv = sserv ? dupstr(sports) : NULL;
4980 pfrec->sport = sport;
4981 pfrec->daddr = host;
4982 pfrec->dserv = dserv ? dupstr(dports) : NULL;
4983 pfrec->dport = dport;
4984 pfrec->local = NULL;
4985 pfrec->remote = NULL;
4986 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
4987 address_family == '6' ? ADDRTYPE_IPV6 :
4990 epfrec = add234(ssh->portfwds, pfrec);
4991 if (epfrec != pfrec) {
4992 if (epfrec->status == DESTROY) {
4994 * We already have a port forwarding up and running
4995 * with precisely these parameters. Hence, no need
4996 * to do anything; simply re-tag the existing one
4999 epfrec->status = KEEP;
5002 * Anything else indicates that there was a duplicate
5003 * in our input, which we'll silently ignore.
5005 free_portfwd(pfrec);
5007 pfrec->status = CREATE;
5016 * Now go through and destroy any port forwardings which were
5019 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5020 if (epf->status == DESTROY) {
5023 message = dupprintf("%s port forwarding from %s%s%d",
5024 epf->type == 'L' ? "local" :
5025 epf->type == 'R' ? "remote" : "dynamic",
5026 epf->saddr ? epf->saddr : "",
5027 epf->saddr ? ":" : "",
5030 if (epf->type != 'D') {
5031 char *msg2 = dupprintf("%s to %s:%d", message,
5032 epf->daddr, epf->dport);
5037 logeventf(ssh, "Cancelling %s", message);
5040 /* epf->remote or epf->local may be NULL if setting up a
5041 * forwarding failed. */
5043 struct ssh_rportfwd *rpf = epf->remote;
5044 struct Packet *pktout;
5047 * Cancel the port forwarding at the server
5050 if (ssh->version == 1) {
5052 * We cannot cancel listening ports on the
5053 * server side in SSH-1! There's no message
5054 * to support it. Instead, we simply remove
5055 * the rportfwd record from the local end
5056 * so that any connections the server tries
5057 * to make on it are rejected.
5060 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5061 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
5062 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
5064 ssh2_pkt_addstring(pktout, epf->saddr);
5065 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5066 /* XXX: rport_acceptall may not represent
5067 * what was used to open the original connection,
5068 * since it's reconfigurable. */
5069 ssh2_pkt_addstring(pktout, "");
5071 ssh2_pkt_addstring(pktout, "localhost");
5073 ssh2_pkt_adduint32(pktout, epf->sport);
5074 ssh2_pkt_send(ssh, pktout);
5077 del234(ssh->rportfwds, rpf);
5079 } else if (epf->local) {
5080 pfl_terminate(epf->local);
5083 delpos234(ssh->portfwds, i);
5085 i--; /* so we don't skip one in the list */
5089 * And finally, set up any new port forwardings (status==CREATE).
5091 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5092 if (epf->status == CREATE) {
5093 char *sportdesc, *dportdesc;
5094 sportdesc = dupprintf("%s%s%s%s%d%s",
5095 epf->saddr ? epf->saddr : "",
5096 epf->saddr ? ":" : "",
5097 epf->sserv ? epf->sserv : "",
5098 epf->sserv ? "(" : "",
5100 epf->sserv ? ")" : "");
5101 if (epf->type == 'D') {
5104 dportdesc = dupprintf("%s:%s%s%d%s",
5106 epf->dserv ? epf->dserv : "",
5107 epf->dserv ? "(" : "",
5109 epf->dserv ? ")" : "");
5112 if (epf->type == 'L') {
5113 char *err = pfl_listen(epf->daddr, epf->dport,
5114 epf->saddr, epf->sport,
5115 ssh, conf, &epf->local,
5116 epf->addressfamily);
5118 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
5119 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5120 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5121 sportdesc, dportdesc,
5122 err ? " failed: " : "", err ? err : "");
5125 } else if (epf->type == 'D') {
5126 char *err = pfl_listen(NULL, -1, epf->saddr, epf->sport,
5127 ssh, conf, &epf->local,
5128 epf->addressfamily);
5130 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
5131 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5132 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5134 err ? " failed: " : "", err ? err : "");
5139 struct ssh_rportfwd *pf;
5142 * Ensure the remote port forwardings tree exists.
5144 if (!ssh->rportfwds) {
5145 if (ssh->version == 1)
5146 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
5148 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5151 pf = snew(struct ssh_rportfwd);
5152 pf->share_ctx = NULL;
5153 pf->dhost = dupstr(epf->daddr);
5154 pf->dport = epf->dport;
5156 pf->shost = dupstr(epf->saddr);
5157 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5158 pf->shost = dupstr("");
5160 pf->shost = dupstr("localhost");
5162 pf->sport = epf->sport;
5163 if (add234(ssh->rportfwds, pf) != pf) {
5164 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
5165 epf->daddr, epf->dport);
5168 logeventf(ssh, "Requesting remote port %s"
5169 " forward to %s", sportdesc, dportdesc);
5171 pf->sportdesc = sportdesc;
5176 if (ssh->version == 1) {
5177 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
5178 PKT_INT, epf->sport,
5179 PKT_STR, epf->daddr,
5180 PKT_INT, epf->dport,
5182 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
5184 ssh_rportfwd_succfail, pf);
5186 struct Packet *pktout;
5187 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5188 ssh2_pkt_addstring(pktout, "tcpip-forward");
5189 ssh2_pkt_addbool(pktout, 1);/* want reply */
5190 ssh2_pkt_addstring(pktout, pf->shost);
5191 ssh2_pkt_adduint32(pktout, pf->sport);
5192 ssh2_pkt_send(ssh, pktout);
5194 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
5195 SSH2_MSG_REQUEST_FAILURE,
5196 ssh_rportfwd_succfail, pf);
5205 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
5208 int stringlen, bufsize;
5210 ssh_pkt_getstring(pktin, &string, &stringlen);
5211 if (string == NULL) {
5212 bombout(("Incoming terminal data packet was badly formed"));
5216 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
5218 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
5219 ssh->v1_stdout_throttling = 1;
5220 ssh_throttle_conn(ssh, +1);
5224 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
5226 /* Remote side is trying to open a channel to talk to our
5227 * X-Server. Give them back a local channel number. */
5228 struct ssh_channel *c;
5229 int remoteid = ssh_pkt_getuint32(pktin);
5231 logevent("Received X11 connect request");
5232 /* Refuse if X11 forwarding is disabled. */
5233 if (!ssh->X11_fwd_enabled) {
5234 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5235 PKT_INT, remoteid, PKT_END);
5236 logevent("Rejected X11 connect request");
5238 c = snew(struct ssh_channel);
5241 c->u.x11.xconn = x11_init(ssh->x11authtree, c, NULL, -1);
5242 c->remoteid = remoteid;
5243 c->halfopen = FALSE;
5244 c->localid = alloc_channel_id(ssh);
5246 c->pending_eof = FALSE;
5247 c->throttling_conn = 0;
5248 c->type = CHAN_X11; /* identify channel type */
5249 add234(ssh->channels, c);
5250 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5251 PKT_INT, c->remoteid, PKT_INT,
5252 c->localid, PKT_END);
5253 logevent("Opened X11 forward channel");
5257 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
5259 /* Remote side is trying to open a channel to talk to our
5260 * agent. Give them back a local channel number. */
5261 struct ssh_channel *c;
5262 int remoteid = ssh_pkt_getuint32(pktin);
5264 /* Refuse if agent forwarding is disabled. */
5265 if (!ssh->agentfwd_enabled) {
5266 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5267 PKT_INT, remoteid, PKT_END);
5269 c = snew(struct ssh_channel);
5271 c->remoteid = remoteid;
5272 c->halfopen = FALSE;
5273 c->localid = alloc_channel_id(ssh);
5275 c->pending_eof = FALSE;
5276 c->throttling_conn = 0;
5277 c->type = CHAN_AGENT; /* identify channel type */
5278 c->u.a.lensofar = 0;
5279 c->u.a.message = NULL;
5280 c->u.a.outstanding_requests = 0;
5281 add234(ssh->channels, c);
5282 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5283 PKT_INT, c->remoteid, PKT_INT, c->localid,
5288 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
5290 /* Remote side is trying to open a channel to talk to a
5291 * forwarded port. Give them back a local channel number. */
5292 struct ssh_rportfwd pf, *pfp;
5298 remoteid = ssh_pkt_getuint32(pktin);
5299 ssh_pkt_getstring(pktin, &host, &hostsize);
5300 port = ssh_pkt_getuint32(pktin);
5302 pf.dhost = dupprintf("%.*s", hostsize, host);
5304 pfp = find234(ssh->rportfwds, &pf, NULL);
5307 logeventf(ssh, "Rejected remote port open request for %s:%d",
5309 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5310 PKT_INT, remoteid, PKT_END);
5312 struct ssh_channel *c = snew(struct ssh_channel);
5315 logeventf(ssh, "Received remote port open request for %s:%d",
5317 err = pfd_connect(&c->u.pfd.pf, pf.dhost, port,
5318 c, ssh->conf, pfp->pfrec->addressfamily);
5320 logeventf(ssh, "Port open failed: %s", err);
5323 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5324 PKT_INT, remoteid, PKT_END);
5326 c->remoteid = remoteid;
5327 c->halfopen = FALSE;
5328 c->localid = alloc_channel_id(ssh);
5330 c->pending_eof = FALSE;
5331 c->throttling_conn = 0;
5332 c->type = CHAN_SOCKDATA; /* identify channel type */
5333 add234(ssh->channels, c);
5334 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5335 PKT_INT, c->remoteid, PKT_INT,
5336 c->localid, PKT_END);
5337 logevent("Forwarded port opened successfully");
5344 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5346 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5347 unsigned int localid = ssh_pkt_getuint32(pktin);
5348 struct ssh_channel *c;
5350 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5351 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5352 c->remoteid = localid;
5353 c->halfopen = FALSE;
5354 c->type = CHAN_SOCKDATA;
5355 c->throttling_conn = 0;
5356 pfd_confirm(c->u.pfd.pf);
5359 if (c && c->pending_eof) {
5361 * We have a pending close on this channel,
5362 * which we decided on before the server acked
5363 * the channel open. So now we know the
5364 * remoteid, we can close it again.
5366 ssh_channel_try_eof(c);
5370 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5372 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5373 struct ssh_channel *c;
5375 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5376 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5377 logevent("Forwarded connection refused by server");
5378 pfd_close(c->u.pfd.pf);
5379 del234(ssh->channels, c);
5384 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
5386 /* Remote side closes a channel. */
5387 unsigned i = ssh_pkt_getuint32(pktin);
5388 struct ssh_channel *c;
5389 c = find234(ssh->channels, &i, ssh_channelfind);
5390 if (c && !c->halfopen) {
5392 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
5393 !(c->closes & CLOSES_RCVD_EOF)) {
5395 * Received CHANNEL_CLOSE, which we translate into
5398 int send_close = FALSE;
5400 c->closes |= CLOSES_RCVD_EOF;
5405 x11_send_eof(c->u.x11.xconn);
5411 pfd_send_eof(c->u.pfd.pf);
5420 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
5421 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
5423 c->closes |= CLOSES_SENT_EOF;
5427 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
5428 !(c->closes & CLOSES_RCVD_CLOSE)) {
5430 if (!(c->closes & CLOSES_SENT_EOF)) {
5431 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
5432 " for which we never sent CHANNEL_CLOSE\n", i));
5435 c->closes |= CLOSES_RCVD_CLOSE;
5438 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
5439 !(c->closes & CLOSES_SENT_CLOSE)) {
5440 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
5441 PKT_INT, c->remoteid, PKT_END);
5442 c->closes |= CLOSES_SENT_CLOSE;
5445 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5446 ssh_channel_destroy(c);
5448 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5449 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
5450 "_CONFIRMATION", c ? "half-open" : "nonexistent",
5455 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5457 /* Data sent down one of our channels. */
5458 int i = ssh_pkt_getuint32(pktin);
5461 struct ssh_channel *c;
5463 ssh_pkt_getstring(pktin, &p, &len);
5465 c = find234(ssh->channels, &i, ssh_channelfind);
5470 bufsize = x11_send(c->u.x11.xconn, p, len);
5473 bufsize = pfd_send(c->u.pfd.pf, p, len);
5476 /* Data for an agent message. Buffer it. */
5478 if (c->u.a.lensofar < 4) {
5479 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
5480 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
5484 c->u.a.lensofar += l;
5486 if (c->u.a.lensofar == 4) {
5488 4 + GET_32BIT(c->u.a.msglen);
5489 c->u.a.message = snewn(c->u.a.totallen,
5491 memcpy(c->u.a.message, c->u.a.msglen, 4);
5493 if (c->u.a.lensofar >= 4 && len > 0) {
5495 min(c->u.a.totallen - c->u.a.lensofar,
5497 memcpy(c->u.a.message + c->u.a.lensofar, p,
5501 c->u.a.lensofar += l;
5503 if (c->u.a.lensofar == c->u.a.totallen) {
5506 c->u.a.outstanding_requests++;
5507 if (agent_query(c->u.a.message,
5510 ssh_agentf_callback, c))
5511 ssh_agentf_callback(c, reply, replylen);
5512 sfree(c->u.a.message);
5513 c->u.a.lensofar = 0;
5516 bufsize = 0; /* agent channels never back up */
5519 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5520 c->throttling_conn = 1;
5521 ssh_throttle_conn(ssh, +1);
5526 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5528 ssh->exitcode = ssh_pkt_getuint32(pktin);
5529 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5530 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5532 * In case `helpful' firewalls or proxies tack
5533 * extra human-readable text on the end of the
5534 * session which we might mistake for another
5535 * encrypted packet, we close the session once
5536 * we've sent EXIT_CONFIRMATION.
5538 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5541 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5542 static void ssh1_send_ttymode(void *data, char *mode, char *val)
5544 struct Packet *pktout = (struct Packet *)data;
5546 unsigned int arg = 0;
5547 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5548 if (i == lenof(ssh_ttymodes)) return;
5549 switch (ssh_ttymodes[i].type) {
5551 arg = ssh_tty_parse_specchar(val);
5554 arg = ssh_tty_parse_boolean(val);
5557 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5558 ssh2_pkt_addbyte(pktout, arg);
5561 int ssh_agent_forwarding_permitted(Ssh ssh)
5563 return conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists();
5566 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
5567 struct Packet *pktin)
5569 crBegin(ssh->do_ssh1_connection_crstate);
5571 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5572 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5573 ssh1_smsg_stdout_stderr_data;
5575 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5576 ssh1_msg_channel_open_confirmation;
5577 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5578 ssh1_msg_channel_open_failure;
5579 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5580 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5581 ssh1_msg_channel_close;
5582 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5583 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5585 if (ssh_agent_forwarding_permitted(ssh)) {
5586 logevent("Requesting agent forwarding");
5587 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5591 if (pktin->type != SSH1_SMSG_SUCCESS
5592 && pktin->type != SSH1_SMSG_FAILURE) {
5593 bombout(("Protocol confusion"));
5595 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5596 logevent("Agent forwarding refused");
5598 logevent("Agent forwarding enabled");
5599 ssh->agentfwd_enabled = TRUE;
5600 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5604 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
5606 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5608 if (!ssh->x11disp) {
5609 /* FIXME: return an error message from x11_setup_display */
5610 logevent("X11 forwarding not enabled: unable to"
5611 " initialise X display");
5613 ssh->x11auth = x11_invent_fake_auth
5614 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
5615 ssh->x11auth->disp = ssh->x11disp;
5617 logevent("Requesting X11 forwarding");
5618 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5619 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5620 PKT_STR, ssh->x11auth->protoname,
5621 PKT_STR, ssh->x11auth->datastring,
5622 PKT_INT, ssh->x11disp->screennum,
5625 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5626 PKT_STR, ssh->x11auth->protoname,
5627 PKT_STR, ssh->x11auth->datastring,
5633 if (pktin->type != SSH1_SMSG_SUCCESS
5634 && pktin->type != SSH1_SMSG_FAILURE) {
5635 bombout(("Protocol confusion"));
5637 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5638 logevent("X11 forwarding refused");
5640 logevent("X11 forwarding enabled");
5641 ssh->X11_fwd_enabled = TRUE;
5642 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5647 ssh_setup_portfwd(ssh, ssh->conf);
5648 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5650 if (!conf_get_int(ssh->conf, CONF_nopty)) {
5652 /* Unpick the terminal-speed string. */
5653 /* XXX perhaps we should allow no speeds to be sent. */
5654 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5655 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
5656 /* Send the pty request. */
5657 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5658 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
5659 ssh_pkt_adduint32(pkt, ssh->term_height);
5660 ssh_pkt_adduint32(pkt, ssh->term_width);
5661 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5662 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5663 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
5664 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5665 ssh_pkt_adduint32(pkt, ssh->ispeed);
5666 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5667 ssh_pkt_adduint32(pkt, ssh->ospeed);
5668 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5670 ssh->state = SSH_STATE_INTERMED;
5674 if (pktin->type != SSH1_SMSG_SUCCESS
5675 && pktin->type != SSH1_SMSG_FAILURE) {
5676 bombout(("Protocol confusion"));
5678 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5679 c_write_str(ssh, "Server refused to allocate pty\r\n");
5680 ssh->editing = ssh->echoing = 1;
5682 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5683 ssh->ospeed, ssh->ispeed);
5684 ssh->got_pty = TRUE;
5687 ssh->editing = ssh->echoing = 1;
5690 if (conf_get_int(ssh->conf, CONF_compression)) {
5691 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5695 if (pktin->type != SSH1_SMSG_SUCCESS
5696 && pktin->type != SSH1_SMSG_FAILURE) {
5697 bombout(("Protocol confusion"));
5699 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5700 c_write_str(ssh, "Server refused to compress\r\n");
5702 logevent("Started compression");
5703 ssh->v1_compressing = TRUE;
5704 ssh->cs_comp_ctx = zlib_compress_init();
5705 logevent("Initialised zlib (RFC1950) compression");
5706 ssh->sc_comp_ctx = zlib_decompress_init();
5707 logevent("Initialised zlib (RFC1950) decompression");
5711 * Start the shell or command.
5713 * Special case: if the first-choice command is an SSH-2
5714 * subsystem (hence not usable here) and the second choice
5715 * exists, we fall straight back to that.
5718 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
5720 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
5721 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
5722 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
5723 ssh->fallback_cmd = TRUE;
5726 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
5728 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
5729 logevent("Started session");
5732 ssh->state = SSH_STATE_SESSION;
5733 if (ssh->size_needed)
5734 ssh_size(ssh, ssh->term_width, ssh->term_height);
5735 if (ssh->eof_needed)
5736 ssh_special(ssh, TS_EOF);
5739 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5741 ssh->channels = newtree234(ssh_channelcmp);
5745 * By this point, most incoming packets are already being
5746 * handled by the dispatch table, and we need only pay
5747 * attention to the unusual ones.
5752 if (pktin->type == SSH1_SMSG_SUCCESS) {
5753 /* may be from EXEC_SHELL on some servers */
5754 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5755 /* may be from EXEC_SHELL on some servers
5756 * if no pty is available or in other odd cases. Ignore */
5758 bombout(("Strange packet received: type %d", pktin->type));
5763 int len = min(inlen, 512);
5764 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
5765 PKT_INT, len, PKT_DATA, in, len,
5777 * Handle the top-level SSH-2 protocol.
5779 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
5784 ssh_pkt_getstring(pktin, &msg, &msglen);
5785 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
5788 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
5790 /* log reason code in disconnect message */
5794 ssh_pkt_getstring(pktin, &msg, &msglen);
5795 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
5798 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
5800 /* Do nothing, because we're ignoring it! Duhh. */
5803 static void ssh1_protocol_setup(Ssh ssh)
5808 * Most messages are handled by the coroutines.
5810 for (i = 0; i < 256; i++)
5811 ssh->packet_dispatch[i] = NULL;
5814 * These special message types we install handlers for.
5816 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
5817 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
5818 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
5821 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
5822 struct Packet *pktin)
5824 unsigned char *in=(unsigned char*)vin;
5825 if (ssh->state == SSH_STATE_CLOSED)
5828 if (pktin && ssh->packet_dispatch[pktin->type]) {
5829 ssh->packet_dispatch[pktin->type](ssh, pktin);
5833 if (!ssh->protocol_initial_phase_done) {
5834 if (do_ssh1_login(ssh, in, inlen, pktin))
5835 ssh->protocol_initial_phase_done = TRUE;
5840 do_ssh1_connection(ssh, in, inlen, pktin);
5844 * Utility routine for decoding comma-separated strings in KEXINIT.
5846 static int in_commasep_string(char *needle, char *haystack, int haylen)
5849 if (!needle || !haystack) /* protect against null pointers */
5851 needlen = strlen(needle);
5854 * Is it at the start of the string?
5856 if (haylen >= needlen && /* haystack is long enough */
5857 !memcmp(needle, haystack, needlen) && /* initial match */
5858 (haylen == needlen || haystack[needlen] == ',')
5859 /* either , or EOS follows */
5863 * If not, search for the next comma and resume after that.
5864 * If no comma found, terminate.
5866 while (haylen > 0 && *haystack != ',')
5867 haylen--, haystack++;
5870 haylen--, haystack++; /* skip over comma itself */
5875 * Similar routine for checking whether we have the first string in a list.
5877 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
5880 if (!needle || !haystack) /* protect against null pointers */
5882 needlen = strlen(needle);
5884 * Is it at the start of the string?
5886 if (haylen >= needlen && /* haystack is long enough */
5887 !memcmp(needle, haystack, needlen) && /* initial match */
5888 (haylen == needlen || haystack[needlen] == ',')
5889 /* either , or EOS follows */
5897 * SSH-2 key creation method.
5898 * (Currently assumes 2 lots of any hash are sufficient to generate
5899 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
5901 #define SSH2_MKKEY_ITERS (2)
5902 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
5903 unsigned char *keyspace)
5905 const struct ssh_hash *h = ssh->kex->hash;
5907 /* First hlen bytes. */
5909 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5910 hash_mpint(h, s, K);
5911 h->bytes(s, H, h->hlen);
5912 h->bytes(s, &chr, 1);
5913 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
5914 h->final(s, keyspace);
5915 /* Next hlen bytes. */
5917 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5918 hash_mpint(h, s, K);
5919 h->bytes(s, H, h->hlen);
5920 h->bytes(s, keyspace, h->hlen);
5921 h->final(s, keyspace + h->hlen);
5925 * Handle the SSH-2 transport layer.
5927 static void do_ssh2_transport(Ssh ssh, void *vin, int inlen,
5928 struct Packet *pktin)
5930 unsigned char *in = (unsigned char *)vin;
5931 struct do_ssh2_transport_state {
5933 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
5934 Bignum p, g, e, f, K;
5937 int kex_init_value, kex_reply_value;
5938 const struct ssh_mac **maclist;
5940 const struct ssh2_cipher *cscipher_tobe;
5941 const struct ssh2_cipher *sccipher_tobe;
5942 const struct ssh_mac *csmac_tobe;
5943 const struct ssh_mac *scmac_tobe;
5944 const struct ssh_compress *cscomp_tobe;
5945 const struct ssh_compress *sccomp_tobe;
5946 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
5947 int hostkeylen, siglen, rsakeylen;
5948 void *hkey; /* actual host key */
5949 void *rsakey; /* for RSA kex */
5950 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
5951 int n_preferred_kex;
5952 const struct ssh_kexes *preferred_kex[KEX_MAX];
5953 int n_preferred_ciphers;
5954 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
5955 const struct ssh_compress *preferred_comp;
5956 int userauth_succeeded; /* for delayed compression */
5957 int pending_compression;
5958 int got_session_id, activated_authconn;
5959 struct Packet *pktout;
5964 crState(do_ssh2_transport_state);
5966 assert(!ssh->bare_connection);
5970 s->cscipher_tobe = s->sccipher_tobe = NULL;
5971 s->csmac_tobe = s->scmac_tobe = NULL;
5972 s->cscomp_tobe = s->sccomp_tobe = NULL;
5974 s->got_session_id = s->activated_authconn = FALSE;
5975 s->userauth_succeeded = FALSE;
5976 s->pending_compression = FALSE;
5979 * Be prepared to work around the buggy MAC problem.
5981 if (ssh->remote_bugs & BUG_SSH2_HMAC)
5982 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
5984 s->maclist = macs, s->nmacs = lenof(macs);
5987 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
5989 int i, j, k, commalist_started;
5992 * Set up the preferred key exchange. (NULL => warn below here)
5994 s->n_preferred_kex = 0;
5995 for (i = 0; i < KEX_MAX; i++) {
5996 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
5998 s->preferred_kex[s->n_preferred_kex++] =
5999 &ssh_diffiehellman_gex;
6002 s->preferred_kex[s->n_preferred_kex++] =
6003 &ssh_diffiehellman_group14;
6006 s->preferred_kex[s->n_preferred_kex++] =
6007 &ssh_diffiehellman_group1;
6010 s->preferred_kex[s->n_preferred_kex++] =
6014 /* Flag for later. Don't bother if it's the last in
6016 if (i < KEX_MAX - 1) {
6017 s->preferred_kex[s->n_preferred_kex++] = NULL;
6024 * Set up the preferred ciphers. (NULL => warn below here)
6026 s->n_preferred_ciphers = 0;
6027 for (i = 0; i < CIPHER_MAX; i++) {
6028 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
6029 case CIPHER_BLOWFISH:
6030 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
6033 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
6034 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
6038 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
6041 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
6043 case CIPHER_ARCFOUR:
6044 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
6047 /* Flag for later. Don't bother if it's the last in
6049 if (i < CIPHER_MAX - 1) {
6050 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
6057 * Set up preferred compression.
6059 if (conf_get_int(ssh->conf, CONF_compression))
6060 s->preferred_comp = &ssh_zlib;
6062 s->preferred_comp = &ssh_comp_none;
6065 * Enable queueing of outgoing auth- or connection-layer
6066 * packets while we are in the middle of a key exchange.
6068 ssh->queueing = TRUE;
6071 * Flag that KEX is in progress.
6073 ssh->kex_in_progress = TRUE;
6076 * Construct and send our key exchange packet.
6078 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
6079 for (i = 0; i < 16; i++)
6080 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
6081 /* List key exchange algorithms. */
6082 ssh2_pkt_addstring_start(s->pktout);
6083 commalist_started = 0;
6084 for (i = 0; i < s->n_preferred_kex; i++) {
6085 const struct ssh_kexes *k = s->preferred_kex[i];
6086 if (!k) continue; /* warning flag */
6087 for (j = 0; j < k->nkexes; j++) {
6088 if (commalist_started)
6089 ssh2_pkt_addstring_str(s->pktout, ",");
6090 ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
6091 commalist_started = 1;
6094 /* List server host key algorithms. */
6095 if (!s->got_session_id) {
6097 * In the first key exchange, we list all the algorithms
6098 * we're prepared to cope with.
6100 ssh2_pkt_addstring_start(s->pktout);
6101 for (i = 0; i < lenof(hostkey_algs); i++) {
6102 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
6103 if (i < lenof(hostkey_algs) - 1)
6104 ssh2_pkt_addstring_str(s->pktout, ",");
6108 * In subsequent key exchanges, we list only the kex
6109 * algorithm that was selected in the first key exchange,
6110 * so that we keep getting the same host key and hence
6111 * don't have to interrupt the user's session to ask for
6115 ssh2_pkt_addstring(s->pktout, ssh->hostkey->name);
6117 /* List encryption algorithms (client->server then server->client). */
6118 for (k = 0; k < 2; k++) {
6119 ssh2_pkt_addstring_start(s->pktout);
6120 commalist_started = 0;
6121 for (i = 0; i < s->n_preferred_ciphers; i++) {
6122 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6123 if (!c) continue; /* warning flag */
6124 for (j = 0; j < c->nciphers; j++) {
6125 if (commalist_started)
6126 ssh2_pkt_addstring_str(s->pktout, ",");
6127 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
6128 commalist_started = 1;
6132 /* List MAC algorithms (client->server then server->client). */
6133 for (j = 0; j < 2; j++) {
6134 ssh2_pkt_addstring_start(s->pktout);
6135 for (i = 0; i < s->nmacs; i++) {
6136 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
6137 if (i < s->nmacs - 1)
6138 ssh2_pkt_addstring_str(s->pktout, ",");
6141 /* List client->server compression algorithms,
6142 * then server->client compression algorithms. (We use the
6143 * same set twice.) */
6144 for (j = 0; j < 2; j++) {
6145 ssh2_pkt_addstring_start(s->pktout);
6146 assert(lenof(compressions) > 1);
6147 /* Prefer non-delayed versions */
6148 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
6149 /* We don't even list delayed versions of algorithms until
6150 * they're allowed to be used, to avoid a race. See the end of
6152 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
6153 ssh2_pkt_addstring_str(s->pktout, ",");
6154 ssh2_pkt_addstring_str(s->pktout,
6155 s->preferred_comp->delayed_name);
6157 for (i = 0; i < lenof(compressions); i++) {
6158 const struct ssh_compress *c = compressions[i];
6159 if (c != s->preferred_comp) {
6160 ssh2_pkt_addstring_str(s->pktout, ",");
6161 ssh2_pkt_addstring_str(s->pktout, c->name);
6162 if (s->userauth_succeeded && c->delayed_name) {
6163 ssh2_pkt_addstring_str(s->pktout, ",");
6164 ssh2_pkt_addstring_str(s->pktout, c->delayed_name);
6169 /* List client->server languages. Empty list. */
6170 ssh2_pkt_addstring_start(s->pktout);
6171 /* List server->client languages. Empty list. */
6172 ssh2_pkt_addstring_start(s->pktout);
6173 /* First KEX packet does _not_ follow, because we're not that brave. */
6174 ssh2_pkt_addbool(s->pktout, FALSE);
6176 ssh2_pkt_adduint32(s->pktout, 0);
6179 s->our_kexinitlen = s->pktout->length - 5;
6180 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
6181 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
6183 ssh2_pkt_send_noqueue(ssh, s->pktout);
6186 crWaitUntilV(pktin);
6189 * Now examine the other side's KEXINIT to see what we're up
6193 char *str, *preferred;
6196 if (pktin->type != SSH2_MSG_KEXINIT) {
6197 bombout(("expected key exchange packet from server"));
6201 ssh->hostkey = NULL;
6202 s->cscipher_tobe = NULL;
6203 s->sccipher_tobe = NULL;
6204 s->csmac_tobe = NULL;
6205 s->scmac_tobe = NULL;
6206 s->cscomp_tobe = NULL;
6207 s->sccomp_tobe = NULL;
6208 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
6210 pktin->savedpos += 16; /* skip garbage cookie */
6211 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
6214 for (i = 0; i < s->n_preferred_kex; i++) {
6215 const struct ssh_kexes *k = s->preferred_kex[i];
6219 for (j = 0; j < k->nkexes; j++) {
6220 if (!preferred) preferred = k->list[j]->name;
6221 if (in_commasep_string(k->list[j]->name, str, len)) {
6222 ssh->kex = k->list[j];
6231 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
6232 str ? str : "(null)"));
6236 * Note that the server's guess is considered wrong if it doesn't match
6237 * the first algorithm in our list, even if it's still the algorithm
6240 s->guessok = first_in_commasep_string(preferred, str, len);
6241 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
6242 for (i = 0; i < lenof(hostkey_algs); i++) {
6243 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
6244 ssh->hostkey = hostkey_algs[i];
6248 if (!ssh->hostkey) {
6249 bombout(("Couldn't agree a host key algorithm (available: %s)",
6250 str ? str : "(null)"));
6254 s->guessok = s->guessok &&
6255 first_in_commasep_string(hostkey_algs[0]->name, str, len);
6256 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
6257 for (i = 0; i < s->n_preferred_ciphers; i++) {
6258 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6260 s->warn_cscipher = TRUE;
6262 for (j = 0; j < c->nciphers; j++) {
6263 if (in_commasep_string(c->list[j]->name, str, len)) {
6264 s->cscipher_tobe = c->list[j];
6269 if (s->cscipher_tobe)
6272 if (!s->cscipher_tobe) {
6273 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
6274 str ? str : "(null)"));
6278 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
6279 for (i = 0; i < s->n_preferred_ciphers; i++) {
6280 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6282 s->warn_sccipher = TRUE;
6284 for (j = 0; j < c->nciphers; j++) {
6285 if (in_commasep_string(c->list[j]->name, str, len)) {
6286 s->sccipher_tobe = c->list[j];
6291 if (s->sccipher_tobe)
6294 if (!s->sccipher_tobe) {
6295 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
6296 str ? str : "(null)"));
6300 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
6301 for (i = 0; i < s->nmacs; i++) {
6302 if (in_commasep_string(s->maclist[i]->name, str, len)) {
6303 s->csmac_tobe = s->maclist[i];
6307 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
6308 for (i = 0; i < s->nmacs; i++) {
6309 if (in_commasep_string(s->maclist[i]->name, str, len)) {
6310 s->scmac_tobe = s->maclist[i];
6314 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
6315 for (i = 0; i < lenof(compressions) + 1; i++) {
6316 const struct ssh_compress *c =
6317 i == 0 ? s->preferred_comp : compressions[i - 1];
6318 if (in_commasep_string(c->name, str, len)) {
6321 } else if (in_commasep_string(c->delayed_name, str, len)) {
6322 if (s->userauth_succeeded) {
6326 s->pending_compression = TRUE; /* try this later */
6330 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
6331 for (i = 0; i < lenof(compressions) + 1; i++) {
6332 const struct ssh_compress *c =
6333 i == 0 ? s->preferred_comp : compressions[i - 1];
6334 if (in_commasep_string(c->name, str, len)) {
6337 } else if (in_commasep_string(c->delayed_name, str, len)) {
6338 if (s->userauth_succeeded) {
6342 s->pending_compression = TRUE; /* try this later */
6346 if (s->pending_compression) {
6347 logevent("Server supports delayed compression; "
6348 "will try this later");
6350 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
6351 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
6352 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
6354 ssh->exhash = ssh->kex->hash->init();
6355 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
6356 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
6357 hash_string(ssh->kex->hash, ssh->exhash,
6358 s->our_kexinit, s->our_kexinitlen);
6359 sfree(s->our_kexinit);
6360 /* Include the type byte in the hash of server's KEXINIT */
6361 hash_string(ssh->kex->hash, ssh->exhash,
6362 pktin->body - 1, pktin->length + 1);
6365 ssh_set_frozen(ssh, 1);
6366 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
6368 ssh_dialog_callback, ssh);
6369 if (s->dlgret < 0) {
6373 bombout(("Unexpected data from server while"
6374 " waiting for user response"));
6377 } while (pktin || inlen > 0);
6378 s->dlgret = ssh->user_response;
6380 ssh_set_frozen(ssh, 0);
6381 if (s->dlgret == 0) {
6382 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
6388 if (s->warn_cscipher) {
6389 ssh_set_frozen(ssh, 1);
6390 s->dlgret = askalg(ssh->frontend,
6391 "client-to-server cipher",
6392 s->cscipher_tobe->name,
6393 ssh_dialog_callback, ssh);
6394 if (s->dlgret < 0) {
6398 bombout(("Unexpected data from server while"
6399 " waiting for user response"));
6402 } while (pktin || inlen > 0);
6403 s->dlgret = ssh->user_response;
6405 ssh_set_frozen(ssh, 0);
6406 if (s->dlgret == 0) {
6407 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6413 if (s->warn_sccipher) {
6414 ssh_set_frozen(ssh, 1);
6415 s->dlgret = askalg(ssh->frontend,
6416 "server-to-client cipher",
6417 s->sccipher_tobe->name,
6418 ssh_dialog_callback, ssh);
6419 if (s->dlgret < 0) {
6423 bombout(("Unexpected data from server while"
6424 " waiting for user response"));
6427 } while (pktin || inlen > 0);
6428 s->dlgret = ssh->user_response;
6430 ssh_set_frozen(ssh, 0);
6431 if (s->dlgret == 0) {
6432 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6438 if (s->ignorepkt) /* first_kex_packet_follows */
6439 crWaitUntilV(pktin); /* Ignore packet */
6442 if (ssh->kex->main_type == KEXTYPE_DH) {
6444 * Work out the number of bits of key we will need from the
6445 * key exchange. We start with the maximum key length of
6451 csbits = s->cscipher_tobe->keylen;
6452 scbits = s->sccipher_tobe->keylen;
6453 s->nbits = (csbits > scbits ? csbits : scbits);
6455 /* The keys only have hlen-bit entropy, since they're based on
6456 * a hash. So cap the key size at hlen bits. */
6457 if (s->nbits > ssh->kex->hash->hlen * 8)
6458 s->nbits = ssh->kex->hash->hlen * 8;
6461 * If we're doing Diffie-Hellman group exchange, start by
6462 * requesting a group.
6464 if (!ssh->kex->pdata) {
6465 logevent("Doing Diffie-Hellman group exchange");
6466 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
6468 * Work out how big a DH group we will need to allow that
6471 s->pbits = 512 << ((s->nbits - 1) / 64);
6472 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6473 ssh2_pkt_adduint32(s->pktout, s->pbits);
6474 ssh2_pkt_send_noqueue(ssh, s->pktout);
6476 crWaitUntilV(pktin);
6477 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6478 bombout(("expected key exchange group packet from server"));
6481 s->p = ssh2_pkt_getmp(pktin);
6482 s->g = ssh2_pkt_getmp(pktin);
6483 if (!s->p || !s->g) {
6484 bombout(("unable to read mp-ints from incoming group packet"));
6487 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6488 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6489 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6491 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
6492 ssh->kex_ctx = dh_setup_group(ssh->kex);
6493 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6494 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6495 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6496 ssh->kex->groupname);
6499 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6500 ssh->kex->hash->text_name);
6502 * Now generate and send e for Diffie-Hellman.
6504 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6505 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6506 s->pktout = ssh2_pkt_init(s->kex_init_value);
6507 ssh2_pkt_addmp(s->pktout, s->e);
6508 ssh2_pkt_send_noqueue(ssh, s->pktout);
6510 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
6511 crWaitUntilV(pktin);
6512 if (pktin->type != s->kex_reply_value) {
6513 bombout(("expected key exchange reply packet from server"));
6516 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
6517 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6518 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6519 s->f = ssh2_pkt_getmp(pktin);
6521 bombout(("unable to parse key exchange reply packet"));
6524 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6526 s->K = dh_find_K(ssh->kex_ctx, s->f);
6528 /* We assume everything from now on will be quick, and it might
6529 * involve user interaction. */
6530 set_busy_status(ssh->frontend, BUSY_NOT);
6532 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6533 if (!ssh->kex->pdata) {
6534 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
6535 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
6536 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
6538 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
6539 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
6541 dh_cleanup(ssh->kex_ctx);
6543 if (!ssh->kex->pdata) {
6548 logeventf(ssh, "Doing RSA key exchange with hash %s",
6549 ssh->kex->hash->text_name);
6550 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
6552 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6555 crWaitUntilV(pktin);
6556 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
6557 bombout(("expected RSA public key packet from server"));
6561 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6562 hash_string(ssh->kex->hash, ssh->exhash,
6563 s->hostkeydata, s->hostkeylen);
6564 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6568 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
6569 s->rsakeydata = snewn(s->rsakeylen, char);
6570 memcpy(s->rsakeydata, keydata, s->rsakeylen);
6573 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
6575 sfree(s->rsakeydata);
6576 bombout(("unable to parse RSA public key from server"));
6580 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
6583 * Next, set up a shared secret K, of precisely KLEN -
6584 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6585 * RSA key modulus and HLEN is the bit length of the hash
6589 int klen = ssh_rsakex_klen(s->rsakey);
6590 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
6592 unsigned char *kstr1, *kstr2, *outstr;
6593 int kstr1len, kstr2len, outstrlen;
6595 s->K = bn_power_2(nbits - 1);
6597 for (i = 0; i < nbits; i++) {
6599 byte = random_byte();
6601 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
6605 * Encode this as an mpint.
6607 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
6608 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
6609 PUT_32BIT(kstr2, kstr1len);
6610 memcpy(kstr2 + 4, kstr1, kstr1len);
6613 * Encrypt it with the given RSA key.
6615 outstrlen = (klen + 7) / 8;
6616 outstr = snewn(outstrlen, unsigned char);
6617 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
6618 outstr, outstrlen, s->rsakey);
6621 * And send it off in a return packet.
6623 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
6624 ssh2_pkt_addstring_start(s->pktout);
6625 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
6626 ssh2_pkt_send_noqueue(ssh, s->pktout);
6628 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
6635 ssh_rsakex_freekey(s->rsakey);
6637 crWaitUntilV(pktin);
6638 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
6639 sfree(s->rsakeydata);
6640 bombout(("expected signature packet from server"));
6644 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6646 sfree(s->rsakeydata);
6649 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
6650 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
6651 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
6653 ssh->kex_ctx = NULL;
6656 debug(("Exchange hash is:\n"));
6657 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
6661 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
6662 (char *)s->exchange_hash,
6663 ssh->kex->hash->hlen)) {
6664 bombout(("Server's host key did not match the signature supplied"));
6668 s->keystr = ssh->hostkey->fmtkey(s->hkey);
6669 if (!s->got_session_id) {
6671 * Authenticate remote host: verify host key. (We've already
6672 * checked the signature of the exchange hash.)
6674 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
6675 ssh_set_frozen(ssh, 1);
6676 s->dlgret = verify_ssh_host_key(ssh->frontend,
6677 ssh->savedhost, ssh->savedport,
6678 ssh->hostkey->keytype, s->keystr,
6680 ssh_dialog_callback, ssh);
6681 if (s->dlgret < 0) {
6685 bombout(("Unexpected data from server while waiting"
6686 " for user host key response"));
6689 } while (pktin || inlen > 0);
6690 s->dlgret = ssh->user_response;
6692 ssh_set_frozen(ssh, 0);
6693 if (s->dlgret == 0) {
6694 ssh_disconnect(ssh, "User aborted at host key verification", NULL,
6698 logevent("Host key fingerprint is:");
6699 logevent(s->fingerprint);
6700 sfree(s->fingerprint);
6702 * Save this host key, to check against the one presented in
6703 * subsequent rekeys.
6705 ssh->hostkey_str = s->keystr;
6708 * In a rekey, we never present an interactive host key
6709 * verification request to the user. Instead, we simply
6710 * enforce that the key we're seeing this time is identical to
6711 * the one we saw before.
6713 if (strcmp(ssh->hostkey_str, s->keystr)) {
6714 bombout(("Host key was different in repeat key exchange"));
6719 ssh->hostkey->freekey(s->hkey);
6722 * The exchange hash from the very first key exchange is also
6723 * the session id, used in session key construction and
6726 if (!s->got_session_id) {
6727 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
6728 memcpy(ssh->v2_session_id, s->exchange_hash,
6729 sizeof(s->exchange_hash));
6730 ssh->v2_session_id_len = ssh->kex->hash->hlen;
6731 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
6732 s->got_session_id = TRUE;
6736 * Send SSH2_MSG_NEWKEYS.
6738 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
6739 ssh2_pkt_send_noqueue(ssh, s->pktout);
6740 ssh->outgoing_data_size = 0; /* start counting from here */
6743 * We've sent client NEWKEYS, so create and initialise
6744 * client-to-server session keys.
6746 if (ssh->cs_cipher_ctx)
6747 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6748 ssh->cscipher = s->cscipher_tobe;
6749 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
6751 if (ssh->cs_mac_ctx)
6752 ssh->csmac->free_context(ssh->cs_mac_ctx);
6753 ssh->csmac = s->csmac_tobe;
6754 ssh->cs_mac_ctx = ssh->csmac->make_context();
6756 if (ssh->cs_comp_ctx)
6757 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6758 ssh->cscomp = s->cscomp_tobe;
6759 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
6762 * Set IVs on client-to-server keys. Here we use the exchange
6763 * hash from the _first_ key exchange.
6766 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6767 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6768 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
6769 assert((ssh->cscipher->keylen+7) / 8 <=
6770 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6771 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
6772 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
6773 assert(ssh->cscipher->blksize <=
6774 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6775 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
6776 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
6777 assert(ssh->csmac->len <=
6778 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6779 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
6780 smemclr(keyspace, sizeof(keyspace));
6783 logeventf(ssh, "Initialised %.200s client->server encryption",
6784 ssh->cscipher->text_name);
6785 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
6786 ssh->csmac->text_name);
6787 if (ssh->cscomp->text_name)
6788 logeventf(ssh, "Initialised %s compression",
6789 ssh->cscomp->text_name);
6792 * Now our end of the key exchange is complete, we can send all
6793 * our queued higher-layer packets.
6795 ssh->queueing = FALSE;
6796 ssh2_pkt_queuesend(ssh);
6799 * Expect SSH2_MSG_NEWKEYS from server.
6801 crWaitUntilV(pktin);
6802 if (pktin->type != SSH2_MSG_NEWKEYS) {
6803 bombout(("expected new-keys packet from server"));
6806 ssh->incoming_data_size = 0; /* start counting from here */
6809 * We've seen server NEWKEYS, so create and initialise
6810 * server-to-client session keys.
6812 if (ssh->sc_cipher_ctx)
6813 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6814 ssh->sccipher = s->sccipher_tobe;
6815 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
6817 if (ssh->sc_mac_ctx)
6818 ssh->scmac->free_context(ssh->sc_mac_ctx);
6819 ssh->scmac = s->scmac_tobe;
6820 ssh->sc_mac_ctx = ssh->scmac->make_context();
6822 if (ssh->sc_comp_ctx)
6823 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
6824 ssh->sccomp = s->sccomp_tobe;
6825 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
6828 * Set IVs on server-to-client keys. Here we use the exchange
6829 * hash from the _first_ key exchange.
6832 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6833 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6834 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
6835 assert((ssh->sccipher->keylen+7) / 8 <=
6836 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6837 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
6838 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
6839 assert(ssh->sccipher->blksize <=
6840 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6841 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
6842 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
6843 assert(ssh->scmac->len <=
6844 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6845 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
6846 smemclr(keyspace, sizeof(keyspace));
6848 logeventf(ssh, "Initialised %.200s server->client encryption",
6849 ssh->sccipher->text_name);
6850 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
6851 ssh->scmac->text_name);
6852 if (ssh->sccomp->text_name)
6853 logeventf(ssh, "Initialised %s decompression",
6854 ssh->sccomp->text_name);
6857 * Free shared secret.
6862 * Key exchange is over. Loop straight back round if we have a
6863 * deferred rekey reason.
6865 if (ssh->deferred_rekey_reason) {
6866 logevent(ssh->deferred_rekey_reason);
6868 ssh->deferred_rekey_reason = NULL;
6869 goto begin_key_exchange;
6873 * Otherwise, schedule a timer for our next rekey.
6875 ssh->kex_in_progress = FALSE;
6876 ssh->last_rekey = GETTICKCOUNT();
6877 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
6878 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
6882 * Now we're encrypting. Begin returning 1 to the protocol main
6883 * function so that other things can run on top of the
6884 * transport. If we ever see a KEXINIT, we must go back to the
6887 * We _also_ go back to the start if we see pktin==NULL and
6888 * inlen negative, because this is a special signal meaning
6889 * `initiate client-driven rekey', and `in' contains a message
6890 * giving the reason for the rekey.
6892 * inlen==-1 means always initiate a rekey;
6893 * inlen==-2 means that userauth has completed successfully and
6894 * we should consider rekeying (for delayed compression).
6896 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
6897 (!pktin && inlen < 0))) {
6899 if (!ssh->protocol_initial_phase_done) {
6900 ssh->protocol_initial_phase_done = TRUE;
6902 * Allow authconn to initialise itself.
6904 do_ssh2_authconn(ssh, NULL, 0, NULL);
6909 logevent("Server initiated key re-exchange");
6913 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
6914 * delayed compression, if it's available.
6916 * draft-miller-secsh-compression-delayed-00 says that you
6917 * negotiate delayed compression in the first key exchange, and
6918 * both sides start compressing when the server has sent
6919 * USERAUTH_SUCCESS. This has a race condition -- the server
6920 * can't know when the client has seen it, and thus which incoming
6921 * packets it should treat as compressed.
6923 * Instead, we do the initial key exchange without offering the
6924 * delayed methods, but note if the server offers them; when we
6925 * get here, if a delayed method was available that was higher
6926 * on our list than what we got, we initiate a rekey in which we
6927 * _do_ list the delayed methods (and hopefully get it as a
6928 * result). Subsequent rekeys will do the same.
6930 assert(!s->userauth_succeeded); /* should only happen once */
6931 s->userauth_succeeded = TRUE;
6932 if (!s->pending_compression)
6933 /* Can't see any point rekeying. */
6934 goto wait_for_rekey; /* this is utterly horrid */
6935 /* else fall through to rekey... */
6936 s->pending_compression = FALSE;
6939 * Now we've decided to rekey.
6941 * Special case: if the server bug is set that doesn't
6942 * allow rekeying, we give a different log message and
6943 * continue waiting. (If such a server _initiates_ a rekey,
6944 * we process it anyway!)
6946 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
6947 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
6949 /* Reset the counters, so that at least this message doesn't
6950 * hit the event log _too_ often. */
6951 ssh->outgoing_data_size = 0;
6952 ssh->incoming_data_size = 0;
6953 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
6955 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
6958 goto wait_for_rekey; /* this is still utterly horrid */
6960 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
6963 goto begin_key_exchange;
6969 * Add data to an SSH-2 channel output buffer.
6971 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
6974 bufchain_add(&c->v.v2.outbuffer, buf, len);
6978 * Attempt to send data on an SSH-2 channel.
6980 static int ssh2_try_send(struct ssh_channel *c)
6983 struct Packet *pktout;
6986 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
6989 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
6990 if ((unsigned)len > c->v.v2.remwindow)
6991 len = c->v.v2.remwindow;
6992 if ((unsigned)len > c->v.v2.remmaxpkt)
6993 len = c->v.v2.remmaxpkt;
6994 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
6995 ssh2_pkt_adduint32(pktout, c->remoteid);
6996 ssh2_pkt_addstring_start(pktout);
6997 ssh2_pkt_addstring_data(pktout, data, len);
6998 ssh2_pkt_send(ssh, pktout);
6999 bufchain_consume(&c->v.v2.outbuffer, len);
7000 c->v.v2.remwindow -= len;
7004 * After having sent as much data as we can, return the amount
7007 ret = bufchain_size(&c->v.v2.outbuffer);
7010 * And if there's no data pending but we need to send an EOF, send
7013 if (!ret && c->pending_eof)
7014 ssh_channel_try_eof(c);
7019 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
7022 if (c->closes & CLOSES_SENT_EOF)
7023 return; /* don't send on channels we've EOFed */
7024 bufsize = ssh2_try_send(c);
7027 case CHAN_MAINSESSION:
7028 /* stdin need not receive an unthrottle
7029 * notification since it will be polled */
7032 x11_unthrottle(c->u.x11.xconn);
7035 /* agent sockets are request/response and need no
7036 * buffer management */
7039 pfd_unthrottle(c->u.pfd.pf);
7045 static int ssh_is_simple(Ssh ssh)
7048 * We use the 'simple' variant of the SSH protocol if we're asked
7049 * to, except not if we're also doing connection-sharing (either
7050 * tunnelling our packets over an upstream or expecting to be
7051 * tunnelled over ourselves), since then the assumption that we
7052 * have only one channel to worry about is not true after all.
7054 return (conf_get_int(ssh->conf, CONF_ssh_simple) &&
7055 !ssh->bare_connection && !ssh->connshare);
7059 * Set up most of a new ssh_channel for SSH-2.
7061 static void ssh2_channel_init(struct ssh_channel *c)
7064 c->localid = alloc_channel_id(ssh);
7066 c->pending_eof = FALSE;
7067 c->throttling_conn = FALSE;
7068 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
7069 ssh_is_simple(ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
7070 c->v.v2.chanreq_head = NULL;
7071 c->v.v2.throttle_state = UNTHROTTLED;
7072 bufchain_init(&c->v.v2.outbuffer);
7076 * Construct the common parts of a CHANNEL_OPEN.
7078 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c, char *type)
7080 struct Packet *pktout;
7082 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7083 ssh2_pkt_addstring(pktout, type);
7084 ssh2_pkt_adduint32(pktout, c->localid);
7085 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7086 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7091 * CHANNEL_FAILURE doesn't come with any indication of what message
7092 * caused it, so we have to keep track of the outstanding
7093 * CHANNEL_REQUESTs ourselves.
7095 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
7096 cchandler_fn_t handler, void *ctx)
7098 struct outstanding_channel_request *ocr =
7099 snew(struct outstanding_channel_request);
7101 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7102 ocr->handler = handler;
7105 if (!c->v.v2.chanreq_head)
7106 c->v.v2.chanreq_head = ocr;
7108 c->v.v2.chanreq_tail->next = ocr;
7109 c->v.v2.chanreq_tail = ocr;
7113 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
7114 * NULL then a reply will be requested and the handler will be called
7115 * when it arrives. The returned packet is ready to have any
7116 * request-specific data added and be sent. Note that if a handler is
7117 * provided, it's essential that the request actually be sent.
7119 * The handler will usually be passed the response packet in pktin.
7120 * If pktin is NULL, this means that no reply will ever be forthcoming
7121 * (e.g. because the entire connection is being destroyed) and the
7122 * handler should free any storage it's holding.
7124 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c, char *type,
7125 cchandler_fn_t handler, void *ctx)
7127 struct Packet *pktout;
7129 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7130 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7131 ssh2_pkt_adduint32(pktout, c->remoteid);
7132 ssh2_pkt_addstring(pktout, type);
7133 ssh2_pkt_addbool(pktout, handler != NULL);
7134 if (handler != NULL)
7135 ssh2_queue_chanreq_handler(c, handler, ctx);
7140 * Potentially enlarge the window on an SSH-2 channel.
7142 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
7144 static void ssh2_set_window(struct ssh_channel *c, int newwin)
7149 * Never send WINDOW_ADJUST for a channel that the remote side has
7150 * already sent EOF on; there's no point, since it won't be
7151 * sending any more data anyway. Ditto if _we've_ already sent
7154 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
7158 * Also, never widen the window for an X11 channel when we're
7159 * still waiting to see its initial auth and may yet hand it off
7162 if (c->type == CHAN_X11 && c->u.x11.initial)
7166 * If the remote end has a habit of ignoring maxpkt, limit the
7167 * window so that it has no choice (assuming it doesn't ignore the
7170 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
7171 newwin = OUR_V2_MAXPKT;
7174 * Only send a WINDOW_ADJUST if there's significantly more window
7175 * available than the other end thinks there is. This saves us
7176 * sending a WINDOW_ADJUST for every character in a shell session.
7178 * "Significant" is arbitrarily defined as half the window size.
7180 if (newwin / 2 >= c->v.v2.locwindow) {
7181 struct Packet *pktout;
7185 * In order to keep track of how much window the client
7186 * actually has available, we'd like it to acknowledge each
7187 * WINDOW_ADJUST. We can't do that directly, so we accompany
7188 * it with a CHANNEL_REQUEST that has to be acknowledged.
7190 * This is only necessary if we're opening the window wide.
7191 * If we're not, then throughput is being constrained by
7192 * something other than the maximum window size anyway.
7194 if (newwin == c->v.v2.locmaxwin &&
7195 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
7196 up = snew(unsigned);
7197 *up = newwin - c->v.v2.locwindow;
7198 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
7199 ssh2_handle_winadj_response, up);
7200 ssh2_pkt_send(ssh, pktout);
7202 if (c->v.v2.throttle_state != UNTHROTTLED)
7203 c->v.v2.throttle_state = UNTHROTTLING;
7205 /* Pretend the WINDOW_ADJUST was acked immediately. */
7206 c->v.v2.remlocwin = newwin;
7207 c->v.v2.throttle_state = THROTTLED;
7209 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7210 ssh2_pkt_adduint32(pktout, c->remoteid);
7211 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
7212 ssh2_pkt_send(ssh, pktout);
7213 c->v.v2.locwindow = newwin;
7218 * Find the channel associated with a message. If there's no channel,
7219 * or it's not properly open, make a noise about it and return NULL.
7221 static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
7223 unsigned localid = ssh_pkt_getuint32(pktin);
7224 struct ssh_channel *c;
7226 c = find234(ssh->channels, &localid, ssh_channelfind);
7228 (c->type != CHAN_SHARING && c->halfopen &&
7229 pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
7230 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
7231 char *buf = dupprintf("Received %s for %s channel %u",
7232 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
7234 c ? "half-open" : "nonexistent", localid);
7235 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
7242 static void ssh2_handle_winadj_response(struct ssh_channel *c,
7243 struct Packet *pktin, void *ctx)
7245 unsigned *sizep = ctx;
7248 * Winadj responses should always be failures. However, at least
7249 * one server ("boks_sshd") is known to return SUCCESS for channel
7250 * requests it's never heard of, such as "winadj@putty". Raised
7251 * with foxt.com as bug 090916-090424, but for the sake of a quiet
7252 * life, we don't worry about what kind of response we got.
7255 c->v.v2.remlocwin += *sizep;
7258 * winadj messages are only sent when the window is fully open, so
7259 * if we get an ack of one, we know any pending unthrottle is
7262 if (c->v.v2.throttle_state == UNTHROTTLING)
7263 c->v.v2.throttle_state = UNTHROTTLED;
7266 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
7268 struct ssh_channel *c = ssh2_channel_msg(ssh, pktin);
7269 struct outstanding_channel_request *ocr;
7272 if (c->type == CHAN_SHARING) {
7273 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7274 pktin->body, pktin->length);
7277 ocr = c->v.v2.chanreq_head;
7279 ssh2_msg_unexpected(ssh, pktin);
7282 ocr->handler(c, pktin, ocr->ctx);
7283 c->v.v2.chanreq_head = ocr->next;
7286 * We may now initiate channel-closing procedures, if that
7287 * CHANNEL_REQUEST was the last thing outstanding before we send
7290 ssh2_channel_check_close(c);
7293 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
7295 struct ssh_channel *c;
7296 c = ssh2_channel_msg(ssh, pktin);
7299 if (c->type == CHAN_SHARING) {
7300 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7301 pktin->body, pktin->length);
7304 if (!(c->closes & CLOSES_SENT_EOF)) {
7305 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
7306 ssh2_try_send_and_unthrottle(ssh, c);
7310 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
7314 struct ssh_channel *c;
7315 c = ssh2_channel_msg(ssh, pktin);
7318 if (c->type == CHAN_SHARING) {
7319 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7320 pktin->body, pktin->length);
7323 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
7324 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
7325 return; /* extended but not stderr */
7326 ssh_pkt_getstring(pktin, &data, &length);
7329 c->v.v2.locwindow -= length;
7330 c->v.v2.remlocwin -= length;
7332 case CHAN_MAINSESSION:
7334 from_backend(ssh->frontend, pktin->type ==
7335 SSH2_MSG_CHANNEL_EXTENDED_DATA,
7339 bufsize = x11_send(c->u.x11.xconn, data, length);
7342 bufsize = pfd_send(c->u.pfd.pf, data, length);
7345 while (length > 0) {
7346 if (c->u.a.lensofar < 4) {
7347 unsigned int l = min(4 - c->u.a.lensofar,
7349 memcpy(c->u.a.msglen + c->u.a.lensofar,
7353 c->u.a.lensofar += l;
7355 if (c->u.a.lensofar == 4) {
7357 4 + GET_32BIT(c->u.a.msglen);
7358 c->u.a.message = snewn(c->u.a.totallen,
7360 memcpy(c->u.a.message, c->u.a.msglen, 4);
7362 if (c->u.a.lensofar >= 4 && length > 0) {
7364 min(c->u.a.totallen - c->u.a.lensofar,
7366 memcpy(c->u.a.message + c->u.a.lensofar,
7370 c->u.a.lensofar += l;
7372 if (c->u.a.lensofar == c->u.a.totallen) {
7375 c->u.a.outstanding_requests++;
7376 if (agent_query(c->u.a.message,
7379 ssh_agentf_callback, c))
7380 ssh_agentf_callback(c, reply, replylen);
7381 sfree(c->u.a.message);
7382 c->u.a.message = NULL;
7383 c->u.a.lensofar = 0;
7390 * If it looks like the remote end hit the end of its window,
7391 * and we didn't want it to do that, think about using a
7394 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
7395 c->v.v2.locmaxwin < 0x40000000)
7396 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
7398 * If we are not buffering too much data,
7399 * enlarge the window again at the remote side.
7400 * If we are buffering too much, we may still
7401 * need to adjust the window if the server's
7404 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
7405 c->v.v2.locmaxwin - bufsize : 0);
7407 * If we're either buffering way too much data, or if we're
7408 * buffering anything at all and we're in "simple" mode,
7409 * throttle the whole channel.
7411 if ((bufsize > c->v.v2.locmaxwin || (ssh_is_simple(ssh) && bufsize>0))
7412 && !c->throttling_conn) {
7413 c->throttling_conn = 1;
7414 ssh_throttle_conn(ssh, +1);
7419 static void ssh_check_termination(Ssh ssh)
7421 if (ssh->version == 2 &&
7422 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
7423 count234(ssh->channels) == 0 &&
7424 !(ssh->connshare && share_ndownstreams(ssh->connshare) > 0)) {
7426 * We used to send SSH_MSG_DISCONNECT here, because I'd
7427 * believed that _every_ conforming SSH-2 connection had to
7428 * end with a disconnect being sent by at least one side;
7429 * apparently I was wrong and it's perfectly OK to
7430 * unceremoniously slam the connection shut when you're done,
7431 * and indeed OpenSSH feels this is more polite than sending a
7432 * DISCONNECT. So now we don't.
7434 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
7438 void ssh_sharing_downstream_connected(Ssh ssh, unsigned id)
7440 logeventf(ssh, "Connection sharing downstream #%u connected", id);
7443 void ssh_sharing_downstream_disconnected(Ssh ssh, unsigned id)
7445 logeventf(ssh, "Connection sharing downstream #%u disconnected", id);
7446 ssh_check_termination(ssh);
7449 void ssh_sharing_logf(Ssh ssh, unsigned id, const char *logfmt, ...)
7454 va_start(ap, logfmt);
7455 buf = dupvprintf(logfmt, ap);
7458 logeventf(ssh, "Connection sharing downstream #%u: %s", id, buf);
7460 logeventf(ssh, "Connection sharing: %s", buf);
7464 static void ssh_channel_destroy(struct ssh_channel *c)
7469 case CHAN_MAINSESSION:
7470 ssh->mainchan = NULL;
7471 update_specials_menu(ssh->frontend);
7474 if (c->u.x11.xconn != NULL)
7475 x11_close(c->u.x11.xconn);
7476 logevent("Forwarded X11 connection terminated");
7479 sfree(c->u.a.message);
7482 if (c->u.pfd.pf != NULL)
7483 pfd_close(c->u.pfd.pf);
7484 logevent("Forwarded port closed");
7488 del234(ssh->channels, c);
7489 if (ssh->version == 2) {
7490 bufchain_clear(&c->v.v2.outbuffer);
7491 assert(c->v.v2.chanreq_head == NULL);
7496 * If that was the last channel left open, we might need to
7499 ssh_check_termination(ssh);
7502 static void ssh2_channel_check_close(struct ssh_channel *c)
7505 struct Packet *pktout;
7509 * If we've sent out our own CHANNEL_OPEN but not yet seen
7510 * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
7511 * it's too early to be sending close messages of any kind.
7516 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
7517 c->type == CHAN_ZOMBIE) &&
7518 !c->v.v2.chanreq_head &&
7519 !(c->closes & CLOSES_SENT_CLOSE)) {
7521 * We have both sent and received EOF (or the channel is a
7522 * zombie), and we have no outstanding channel requests, which
7523 * means the channel is in final wind-up. But we haven't sent
7524 * CLOSE, so let's do so now.
7526 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
7527 ssh2_pkt_adduint32(pktout, c->remoteid);
7528 ssh2_pkt_send(ssh, pktout);
7529 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
7532 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
7533 assert(c->v.v2.chanreq_head == NULL);
7535 * We have both sent and received CLOSE, which means we're
7536 * completely done with the channel.
7538 ssh_channel_destroy(c);
7542 static void ssh2_channel_got_eof(struct ssh_channel *c)
7544 if (c->closes & CLOSES_RCVD_EOF)
7545 return; /* already seen EOF */
7546 c->closes |= CLOSES_RCVD_EOF;
7548 if (c->type == CHAN_X11) {
7549 x11_send_eof(c->u.x11.xconn);
7550 } else if (c->type == CHAN_AGENT) {
7551 if (c->u.a.outstanding_requests == 0) {
7552 /* Manufacture an outgoing EOF in response to the incoming one. */
7553 sshfwd_write_eof(c);
7555 } else if (c->type == CHAN_SOCKDATA) {
7556 pfd_send_eof(c->u.pfd.pf);
7557 } else if (c->type == CHAN_MAINSESSION) {
7560 if (!ssh->sent_console_eof &&
7561 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
7563 * Either from_backend_eof told us that the front end
7564 * wants us to close the outgoing side of the connection
7565 * as soon as we see EOF from the far end, or else we've
7566 * unilaterally decided to do that because we've allocated
7567 * a remote pty and hence EOF isn't a particularly
7568 * meaningful concept.
7570 sshfwd_write_eof(c);
7572 ssh->sent_console_eof = TRUE;
7575 ssh2_channel_check_close(c);
7578 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
7580 struct ssh_channel *c;
7582 c = ssh2_channel_msg(ssh, pktin);
7585 if (c->type == CHAN_SHARING) {
7586 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7587 pktin->body, pktin->length);
7590 ssh2_channel_got_eof(c);
7593 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
7595 struct ssh_channel *c;
7597 c = ssh2_channel_msg(ssh, pktin);
7600 if (c->type == CHAN_SHARING) {
7601 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7602 pktin->body, pktin->length);
7607 * When we receive CLOSE on a channel, we assume it comes with an
7608 * implied EOF if we haven't seen EOF yet.
7610 ssh2_channel_got_eof(c);
7613 * And we also send an outgoing EOF, if we haven't already, on the
7614 * assumption that CLOSE is a pretty forceful announcement that
7615 * the remote side is doing away with the entire channel. (If it
7616 * had wanted to send us EOF and continue receiving data from us,
7617 * it would have just sent CHANNEL_EOF.)
7619 if (!(c->closes & CLOSES_SENT_EOF)) {
7621 * Make sure we don't read any more from whatever our local
7622 * data source is for this channel.
7625 case CHAN_MAINSESSION:
7626 ssh->send_ok = 0; /* stop trying to read from stdin */
7629 x11_override_throttle(c->u.x11.xconn, 1);
7632 pfd_override_throttle(c->u.pfd.pf, 1);
7637 * Abandon any buffered data we still wanted to send to this
7638 * channel. Receiving a CHANNEL_CLOSE is an indication that
7639 * the server really wants to get on and _destroy_ this
7640 * channel, and it isn't going to send us any further
7641 * WINDOW_ADJUSTs to permit us to send pending stuff.
7643 bufchain_clear(&c->v.v2.outbuffer);
7646 * Send outgoing EOF.
7648 sshfwd_write_eof(c);
7652 * Now process the actual close.
7654 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
7655 c->closes |= CLOSES_RCVD_CLOSE;
7656 ssh2_channel_check_close(c);
7660 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
7662 struct ssh_channel *c;
7664 c = ssh2_channel_msg(ssh, pktin);
7667 if (c->type == CHAN_SHARING) {
7668 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7669 pktin->body, pktin->length);
7672 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7673 c->remoteid = ssh_pkt_getuint32(pktin);
7674 c->halfopen = FALSE;
7675 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7676 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7678 if (c->type == CHAN_SOCKDATA_DORMANT) {
7679 c->type = CHAN_SOCKDATA;
7681 pfd_confirm(c->u.pfd.pf);
7682 } else if (c->type == CHAN_ZOMBIE) {
7684 * This case can occur if a local socket error occurred
7685 * between us sending out CHANNEL_OPEN and receiving
7686 * OPEN_CONFIRMATION. In this case, all we can do is
7687 * immediately initiate close proceedings now that we know the
7688 * server's id to put in the close message.
7690 ssh2_channel_check_close(c);
7693 * We never expect to receive OPEN_CONFIRMATION for any
7694 * *other* channel type (since only local-to-remote port
7695 * forwardings cause us to send CHANNEL_OPEN after the main
7696 * channel is live - all other auxiliary channel types are
7697 * initiated from the server end). It's safe to enforce this
7698 * by assertion rather than by ssh_disconnect, because the
7699 * real point is that we never constructed a half-open channel
7700 * structure in the first place with any type other than the
7703 assert(!"Funny channel type in ssh2_msg_channel_open_confirmation");
7707 ssh_channel_try_eof(c); /* in case we had a pending EOF */
7710 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
7712 static const char *const reasons[] = {
7713 "<unknown reason code>",
7714 "Administratively prohibited",
7716 "Unknown channel type",
7717 "Resource shortage",
7719 unsigned reason_code;
7720 char *reason_string;
7722 struct ssh_channel *c;
7724 c = ssh2_channel_msg(ssh, pktin);
7727 if (c->type == CHAN_SHARING) {
7728 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7729 pktin->body, pktin->length);
7732 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7734 if (c->type == CHAN_SOCKDATA_DORMANT) {
7735 reason_code = ssh_pkt_getuint32(pktin);
7736 if (reason_code >= lenof(reasons))
7737 reason_code = 0; /* ensure reasons[reason_code] in range */
7738 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
7739 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
7740 reasons[reason_code], reason_length, reason_string);
7742 pfd_close(c->u.pfd.pf);
7743 } else if (c->type == CHAN_ZOMBIE) {
7745 * This case can occur if a local socket error occurred
7746 * between us sending out CHANNEL_OPEN and receiving
7747 * OPEN_FAILURE. In this case, we need do nothing except allow
7748 * the code below to throw the half-open channel away.
7752 * We never expect to receive OPEN_FAILURE for any *other*
7753 * channel type (since only local-to-remote port forwardings
7754 * cause us to send CHANNEL_OPEN after the main channel is
7755 * live - all other auxiliary channel types are initiated from
7756 * the server end). It's safe to enforce this by assertion
7757 * rather than by ssh_disconnect, because the real point is
7758 * that we never constructed a half-open channel structure in
7759 * the first place with any type other than the above.
7761 assert(!"Funny channel type in ssh2_msg_channel_open_failure");
7764 del234(ssh->channels, c);
7768 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
7771 int typelen, want_reply;
7772 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
7773 struct ssh_channel *c;
7774 struct Packet *pktout;
7776 c = ssh2_channel_msg(ssh, pktin);
7779 if (c->type == CHAN_SHARING) {
7780 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7781 pktin->body, pktin->length);
7784 ssh_pkt_getstring(pktin, &type, &typelen);
7785 want_reply = ssh2_pkt_getbool(pktin);
7788 * Having got the channel number, we now look at
7789 * the request type string to see if it's something
7792 if (c == ssh->mainchan) {
7794 * We recognise "exit-status" and "exit-signal" on
7795 * the primary channel.
7797 if (typelen == 11 &&
7798 !memcmp(type, "exit-status", 11)) {
7800 ssh->exitcode = ssh_pkt_getuint32(pktin);
7801 logeventf(ssh, "Server sent command exit status %d",
7803 reply = SSH2_MSG_CHANNEL_SUCCESS;
7805 } else if (typelen == 11 &&
7806 !memcmp(type, "exit-signal", 11)) {
7808 int is_plausible = TRUE, is_int = FALSE;
7809 char *fmt_sig = "", *fmt_msg = "";
7811 int msglen = 0, core = FALSE;
7812 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
7813 * provide an `int' for the signal, despite its
7814 * having been a `string' in the drafts of RFC 4254 since at
7815 * least 2001. (Fixed in session.c 1.147.) Try to
7816 * infer which we can safely parse it as. */
7818 unsigned char *p = pktin->body +
7820 long len = pktin->length - pktin->savedpos;
7821 unsigned long num = GET_32BIT(p); /* what is it? */
7822 /* If it's 0, it hardly matters; assume string */
7826 int maybe_int = FALSE, maybe_str = FALSE;
7827 #define CHECK_HYPOTHESIS(offset, result) \
7830 int q = toint(offset); \
7831 if (q >= 0 && q+4 <= len) { \
7832 q = toint(q + 4 + GET_32BIT(p+q)); \
7833 if (q >= 0 && q+4 <= len && \
7834 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
7839 CHECK_HYPOTHESIS(4+1, maybe_int);
7840 CHECK_HYPOTHESIS(4+num+1, maybe_str);
7841 #undef CHECK_HYPOTHESIS
7842 if (maybe_int && !maybe_str)
7844 else if (!maybe_int && maybe_str)
7847 /* Crikey. Either or neither. Panic. */
7848 is_plausible = FALSE;
7851 ssh->exitcode = 128; /* means `unknown signal' */
7854 /* Old non-standard OpenSSH. */
7855 int signum = ssh_pkt_getuint32(pktin);
7856 fmt_sig = dupprintf(" %d", signum);
7857 ssh->exitcode = 128 + signum;
7859 /* As per RFC 4254. */
7862 ssh_pkt_getstring(pktin, &sig, &siglen);
7863 /* Signal name isn't supposed to be blank, but
7864 * let's cope gracefully if it is. */
7866 fmt_sig = dupprintf(" \"%.*s\"",
7871 * Really hideous method of translating the
7872 * signal description back into a locally
7873 * meaningful number.
7878 #define TRANSLATE_SIGNAL(s) \
7879 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
7880 ssh->exitcode = 128 + SIG ## s
7882 TRANSLATE_SIGNAL(ABRT);
7885 TRANSLATE_SIGNAL(ALRM);
7888 TRANSLATE_SIGNAL(FPE);
7891 TRANSLATE_SIGNAL(HUP);
7894 TRANSLATE_SIGNAL(ILL);
7897 TRANSLATE_SIGNAL(INT);
7900 TRANSLATE_SIGNAL(KILL);
7903 TRANSLATE_SIGNAL(PIPE);
7906 TRANSLATE_SIGNAL(QUIT);
7909 TRANSLATE_SIGNAL(SEGV);
7912 TRANSLATE_SIGNAL(TERM);
7915 TRANSLATE_SIGNAL(USR1);
7918 TRANSLATE_SIGNAL(USR2);
7920 #undef TRANSLATE_SIGNAL
7922 ssh->exitcode = 128;
7924 core = ssh2_pkt_getbool(pktin);
7925 ssh_pkt_getstring(pktin, &msg, &msglen);
7927 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
7929 /* ignore lang tag */
7930 } /* else don't attempt to parse */
7931 logeventf(ssh, "Server exited on signal%s%s%s",
7932 fmt_sig, core ? " (core dumped)" : "",
7934 if (*fmt_sig) sfree(fmt_sig);
7935 if (*fmt_msg) sfree(fmt_msg);
7936 reply = SSH2_MSG_CHANNEL_SUCCESS;
7941 * This is a channel request we don't know
7942 * about, so we now either ignore the request
7943 * or respond with CHANNEL_FAILURE, depending
7946 reply = SSH2_MSG_CHANNEL_FAILURE;
7949 pktout = ssh2_pkt_init(reply);
7950 ssh2_pkt_adduint32(pktout, c->remoteid);
7951 ssh2_pkt_send(ssh, pktout);
7955 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
7958 int typelen, want_reply;
7959 struct Packet *pktout;
7961 ssh_pkt_getstring(pktin, &type, &typelen);
7962 want_reply = ssh2_pkt_getbool(pktin);
7965 * We currently don't support any global requests
7966 * at all, so we either ignore the request or
7967 * respond with REQUEST_FAILURE, depending on
7971 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
7972 ssh2_pkt_send(ssh, pktout);
7976 struct X11FakeAuth *ssh_sharing_add_x11_display(Ssh ssh, int authtype,
7980 struct X11FakeAuth *auth;
7983 * Make up a new set of fake X11 auth data, and add it to the tree
7984 * of currently valid ones with an indication of the sharing
7985 * context that it's relevant to.
7987 auth = x11_invent_fake_auth(ssh->x11authtree, authtype);
7988 auth->share_cs = share_cs;
7989 auth->share_chan = share_chan;
7994 void ssh_sharing_remove_x11_display(Ssh ssh, struct X11FakeAuth *auth)
7996 del234(ssh->x11authtree, auth);
7997 x11_free_fake_auth(auth);
8000 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
8008 struct ssh_channel *c;
8009 unsigned remid, winsize, pktsize;
8010 unsigned our_winsize_override = 0;
8011 struct Packet *pktout;
8013 ssh_pkt_getstring(pktin, &type, &typelen);
8014 c = snew(struct ssh_channel);
8017 remid = ssh_pkt_getuint32(pktin);
8018 winsize = ssh_pkt_getuint32(pktin);
8019 pktsize = ssh_pkt_getuint32(pktin);
8021 if (typelen == 3 && !memcmp(type, "x11", 3)) {
8024 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8025 addrstr = snewn(peeraddrlen+1, char);
8026 memcpy(addrstr, peeraddr, peeraddrlen);
8027 addrstr[peeraddrlen] = '\0';
8028 peerport = ssh_pkt_getuint32(pktin);
8030 logeventf(ssh, "Received X11 connect request from %s:%d",
8033 if (!ssh->X11_fwd_enabled && !ssh->connshare)
8034 error = "X11 forwarding is not enabled";
8036 c->u.x11.xconn = x11_init(ssh->x11authtree, c,
8039 c->u.x11.initial = TRUE;
8042 * If we are a connection-sharing upstream, then we should
8043 * initially present a very small window, adequate to take
8044 * the X11 initial authorisation packet but not much more.
8045 * Downstream will then present us a larger window (by
8046 * fiat of the connection-sharing protocol) and we can
8047 * guarantee to send a positive-valued WINDOW_ADJUST.
8050 our_winsize_override = 128;
8052 logevent("Opened X11 forward channel");
8056 } else if (typelen == 15 &&
8057 !memcmp(type, "forwarded-tcpip", 15)) {
8058 struct ssh_rportfwd pf, *realpf;
8061 ssh_pkt_getstring(pktin, &shost, &shostlen);/* skip address */
8062 pf.shost = dupprintf("%.*s", shostlen, shost);
8063 pf.sport = ssh_pkt_getuint32(pktin);
8064 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8065 peerport = ssh_pkt_getuint32(pktin);
8066 realpf = find234(ssh->rportfwds, &pf, NULL);
8067 logeventf(ssh, "Received remote port %s:%d open request "
8068 "from %s:%d", pf.shost, pf.sport, peeraddr, peerport);
8071 if (realpf == NULL) {
8072 error = "Remote port is not recognised";
8076 if (realpf->share_ctx) {
8078 * This port forwarding is on behalf of a
8079 * connection-sharing downstream, so abandon our own
8080 * channel-open procedure and just pass the message on
8083 share_got_pkt_from_server(realpf->share_ctx, pktin->type,
8084 pktin->body, pktin->length);
8089 err = pfd_connect(&c->u.pfd.pf, realpf->dhost, realpf->dport,
8090 c, ssh->conf, realpf->pfrec->addressfamily);
8091 logeventf(ssh, "Attempting to forward remote port to "
8092 "%s:%d", realpf->dhost, realpf->dport);
8094 logeventf(ssh, "Port open failed: %s", err);
8096 error = "Port open failed";
8098 logevent("Forwarded port opened successfully");
8099 c->type = CHAN_SOCKDATA;
8102 } else if (typelen == 22 &&
8103 !memcmp(type, "auth-agent@openssh.com", 22)) {
8104 if (!ssh->agentfwd_enabled)
8105 error = "Agent forwarding is not enabled";
8107 c->type = CHAN_AGENT; /* identify channel type */
8108 c->u.a.lensofar = 0;
8109 c->u.a.message = NULL;
8110 c->u.a.outstanding_requests = 0;
8113 error = "Unsupported channel type requested";
8116 c->remoteid = remid;
8117 c->halfopen = FALSE;
8119 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
8120 ssh2_pkt_adduint32(pktout, c->remoteid);
8121 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
8122 ssh2_pkt_addstring(pktout, error);
8123 ssh2_pkt_addstring(pktout, "en"); /* language tag */
8124 ssh2_pkt_send(ssh, pktout);
8125 logeventf(ssh, "Rejected channel open: %s", error);
8128 ssh2_channel_init(c);
8129 c->v.v2.remwindow = winsize;
8130 c->v.v2.remmaxpkt = pktsize;
8131 if (our_winsize_override) {
8132 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
8133 our_winsize_override;
8135 add234(ssh->channels, c);
8136 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
8137 ssh2_pkt_adduint32(pktout, c->remoteid);
8138 ssh2_pkt_adduint32(pktout, c->localid);
8139 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
8140 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8141 ssh2_pkt_send(ssh, pktout);
8145 void sshfwd_x11_sharing_handover(struct ssh_channel *c,
8146 void *share_cs, void *share_chan,
8147 const char *peer_addr, int peer_port,
8148 int endian, int protomajor, int protominor,
8149 const void *initial_data, int initial_len)
8152 * This function is called when we've just discovered that an X
8153 * forwarding channel on which we'd been handling the initial auth
8154 * ourselves turns out to be destined for a connection-sharing
8155 * downstream. So we turn the channel into a CHAN_SHARING, meaning
8156 * that we completely stop tracking windows and buffering data and
8157 * just pass more or less unmodified SSH messages back and forth.
8159 c->type = CHAN_SHARING;
8160 c->u.sharing.ctx = share_cs;
8161 share_setup_x11_channel(share_cs, share_chan,
8162 c->localid, c->remoteid, c->v.v2.remwindow,
8163 c->v.v2.remmaxpkt, c->v.v2.locwindow,
8164 peer_addr, peer_port, endian,
8165 protomajor, protominor,
8166 initial_data, initial_len);
8169 void sshfwd_x11_is_local(struct ssh_channel *c)
8172 * This function is called when we've just discovered that an X
8173 * forwarding channel is _not_ destined for a connection-sharing
8174 * downstream but we're going to handle it ourselves. We stop
8175 * presenting a cautiously small window and go into ordinary data
8178 c->u.x11.initial = FALSE;
8179 ssh2_set_window(c, ssh_is_simple(c->ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE);
8183 * Buffer banner messages for later display at some convenient point,
8184 * if we're going to display them.
8186 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
8188 /* Arbitrary limit to prevent unbounded inflation of buffer */
8189 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
8190 bufchain_size(&ssh->banner) <= 131072) {
8191 char *banner = NULL;
8193 ssh_pkt_getstring(pktin, &banner, &size);
8195 bufchain_add(&ssh->banner, banner, size);
8199 /* Helper function to deal with sending tty modes for "pty-req" */
8200 static void ssh2_send_ttymode(void *data, char *mode, char *val)
8202 struct Packet *pktout = (struct Packet *)data;
8204 unsigned int arg = 0;
8205 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
8206 if (i == lenof(ssh_ttymodes)) return;
8207 switch (ssh_ttymodes[i].type) {
8209 arg = ssh_tty_parse_specchar(val);
8212 arg = ssh_tty_parse_boolean(val);
8215 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
8216 ssh2_pkt_adduint32(pktout, arg);
8219 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
8222 struct ssh2_setup_x11_state {
8226 struct Packet *pktout;
8227 crStateP(ssh2_setup_x11_state, ctx);
8231 logevent("Requesting X11 forwarding");
8232 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
8234 ssh2_pkt_addbool(pktout, 0); /* many connections */
8235 ssh2_pkt_addstring(pktout, ssh->x11auth->protoname);
8236 ssh2_pkt_addstring(pktout, ssh->x11auth->datastring);
8237 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
8238 ssh2_pkt_send(ssh, pktout);
8240 /* Wait to be called back with either a response packet, or NULL
8241 * meaning clean up and free our data */
8245 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8246 logevent("X11 forwarding enabled");
8247 ssh->X11_fwd_enabled = TRUE;
8249 logevent("X11 forwarding refused");
8255 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
8258 struct ssh2_setup_agent_state {
8262 struct Packet *pktout;
8263 crStateP(ssh2_setup_agent_state, ctx);
8267 logevent("Requesting OpenSSH-style agent forwarding");
8268 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
8269 ssh2_setup_agent, s);
8270 ssh2_pkt_send(ssh, pktout);
8272 /* Wait to be called back with either a response packet, or NULL
8273 * meaning clean up and free our data */
8277 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8278 logevent("Agent forwarding enabled");
8279 ssh->agentfwd_enabled = TRUE;
8281 logevent("Agent forwarding refused");
8287 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
8290 struct ssh2_setup_pty_state {
8294 struct Packet *pktout;
8295 crStateP(ssh2_setup_pty_state, ctx);
8299 /* Unpick the terminal-speed string. */
8300 /* XXX perhaps we should allow no speeds to be sent. */
8301 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
8302 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
8303 /* Build the pty request. */
8304 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
8306 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
8307 ssh2_pkt_adduint32(pktout, ssh->term_width);
8308 ssh2_pkt_adduint32(pktout, ssh->term_height);
8309 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
8310 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
8311 ssh2_pkt_addstring_start(pktout);
8312 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
8313 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
8314 ssh2_pkt_adduint32(pktout, ssh->ispeed);
8315 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
8316 ssh2_pkt_adduint32(pktout, ssh->ospeed);
8317 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
8318 ssh2_pkt_send(ssh, pktout);
8319 ssh->state = SSH_STATE_INTERMED;
8321 /* Wait to be called back with either a response packet, or NULL
8322 * meaning clean up and free our data */
8326 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8327 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
8328 ssh->ospeed, ssh->ispeed);
8329 ssh->got_pty = TRUE;
8331 c_write_str(ssh, "Server refused to allocate pty\r\n");
8332 ssh->editing = ssh->echoing = 1;
8339 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
8342 struct ssh2_setup_env_state {
8344 int num_env, env_left, env_ok;
8347 struct Packet *pktout;
8348 crStateP(ssh2_setup_env_state, ctx);
8353 * Send environment variables.
8355 * Simplest thing here is to send all the requests at once, and
8356 * then wait for a whole bunch of successes or failures.
8362 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
8364 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
8365 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
8366 ssh2_pkt_addstring(pktout, key);
8367 ssh2_pkt_addstring(pktout, val);
8368 ssh2_pkt_send(ssh, pktout);
8373 logeventf(ssh, "Sent %d environment variables", s->num_env);
8378 s->env_left = s->num_env;
8380 while (s->env_left > 0) {
8381 /* Wait to be called back with either a response packet,
8382 * or NULL meaning clean up and free our data */
8384 if (!pktin) goto out;
8385 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
8390 if (s->env_ok == s->num_env) {
8391 logevent("All environment variables successfully set");
8392 } else if (s->env_ok == 0) {
8393 logevent("All environment variables refused");
8394 c_write_str(ssh, "Server refused to set environment variables\r\n");
8396 logeventf(ssh, "%d environment variables refused",
8397 s->num_env - s->env_ok);
8398 c_write_str(ssh, "Server refused to set all environment variables\r\n");
8406 * Handle the SSH-2 userauth and connection layers.
8408 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
8410 do_ssh2_authconn(ssh, NULL, 0, pktin);
8413 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
8416 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
8419 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
8420 struct Packet *pktin)
8422 struct do_ssh2_authconn_state {
8426 AUTH_TYPE_PUBLICKEY,
8427 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
8428 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
8430 AUTH_TYPE_GSSAPI, /* always QUIET */
8431 AUTH_TYPE_KEYBOARD_INTERACTIVE,
8432 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
8434 int done_service_req;
8435 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
8436 int tried_pubkey_config, done_agent;
8441 int kbd_inter_refused;
8442 int we_are_in, userauth_success;
8443 prompts_t *cur_prompt;
8448 void *publickey_blob;
8449 int publickey_bloblen;
8450 int publickey_encrypted;
8451 char *publickey_algorithm;
8452 char *publickey_comment;
8453 unsigned char agent_request[5], *agent_response, *agentp;
8454 int agent_responselen;
8455 unsigned char *pkblob_in_agent;
8457 char *pkblob, *alg, *commentp;
8458 int pklen, alglen, commentlen;
8459 int siglen, retlen, len;
8460 char *q, *agentreq, *ret;
8462 struct Packet *pktout;
8465 struct ssh_gss_library *gsslib;
8466 Ssh_gss_ctx gss_ctx;
8467 Ssh_gss_buf gss_buf;
8468 Ssh_gss_buf gss_rcvtok, gss_sndtok;
8469 Ssh_gss_name gss_srv_name;
8470 Ssh_gss_stat gss_stat;
8473 crState(do_ssh2_authconn_state);
8477 /* Register as a handler for all the messages this coroutine handles. */
8478 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
8479 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
8480 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
8481 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
8482 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
8483 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
8484 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
8485 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
8486 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
8487 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
8488 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
8489 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
8490 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
8491 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
8492 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
8493 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
8494 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
8495 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
8496 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
8497 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
8499 s->done_service_req = FALSE;
8500 s->we_are_in = s->userauth_success = FALSE;
8501 s->agent_response = NULL;
8503 s->tried_gssapi = FALSE;
8506 if (!ssh->bare_connection) {
8507 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
8509 * Request userauth protocol, and await a response to it.
8511 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8512 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
8513 ssh2_pkt_send(ssh, s->pktout);
8514 crWaitUntilV(pktin);
8515 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
8516 s->done_service_req = TRUE;
8518 if (!s->done_service_req) {
8520 * Request connection protocol directly, without authentication.
8522 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8523 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8524 ssh2_pkt_send(ssh, s->pktout);
8525 crWaitUntilV(pktin);
8526 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
8527 s->we_are_in = TRUE; /* no auth required */
8529 bombout(("Server refused service request"));
8534 s->we_are_in = TRUE;
8537 /* Arrange to be able to deal with any BANNERs that come in.
8538 * (We do this now as packets may come in during the next bit.) */
8539 bufchain_init(&ssh->banner);
8540 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
8541 ssh2_msg_userauth_banner;
8544 * Misc one-time setup for authentication.
8546 s->publickey_blob = NULL;
8547 if (!s->we_are_in) {
8550 * Load the public half of any configured public key file
8553 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
8554 if (!filename_is_null(s->keyfile)) {
8556 logeventf(ssh, "Reading private key file \"%.150s\"",
8557 filename_to_str(s->keyfile));
8558 keytype = key_type(s->keyfile);
8559 if (keytype == SSH_KEYTYPE_SSH2) {
8562 ssh2_userkey_loadpub(s->keyfile,
8563 &s->publickey_algorithm,
8564 &s->publickey_bloblen,
8565 &s->publickey_comment, &error);
8566 if (s->publickey_blob) {
8567 s->publickey_encrypted =
8568 ssh2_userkey_encrypted(s->keyfile, NULL);
8571 logeventf(ssh, "Unable to load private key (%s)",
8573 msgbuf = dupprintf("Unable to load private key file "
8574 "\"%.150s\" (%s)\r\n",
8575 filename_to_str(s->keyfile),
8577 c_write_str(ssh, msgbuf);
8582 logeventf(ssh, "Unable to use this key file (%s)",
8583 key_type_to_str(keytype));
8584 msgbuf = dupprintf("Unable to use key file \"%.150s\""
8586 filename_to_str(s->keyfile),
8587 key_type_to_str(keytype));
8588 c_write_str(ssh, msgbuf);
8590 s->publickey_blob = NULL;
8595 * Find out about any keys Pageant has (but if there's a
8596 * public key configured, filter out all others).
8599 s->agent_response = NULL;
8600 s->pkblob_in_agent = NULL;
8601 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
8605 logevent("Pageant is running. Requesting keys.");
8607 /* Request the keys held by the agent. */
8608 PUT_32BIT(s->agent_request, 1);
8609 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
8610 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
8611 ssh_agent_callback, ssh)) {
8615 bombout(("Unexpected data from server while"
8616 " waiting for agent response"));
8619 } while (pktin || inlen > 0);
8620 r = ssh->agent_response;
8621 s->agent_responselen = ssh->agent_response_len;
8623 s->agent_response = (unsigned char *) r;
8624 if (s->agent_response && s->agent_responselen >= 5 &&
8625 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
8628 p = s->agent_response + 5;
8629 s->nkeys = toint(GET_32BIT(p));
8632 * Vet the Pageant response to ensure that the key
8633 * count and blob lengths make sense.
8636 logeventf(ssh, "Pageant response contained a negative"
8637 " key count %d", s->nkeys);
8639 goto done_agent_query;
8641 unsigned char *q = p + 4;
8642 int lenleft = s->agent_responselen - 5 - 4;
8644 for (keyi = 0; keyi < s->nkeys; keyi++) {
8645 int bloblen, commentlen;
8647 logeventf(ssh, "Pageant response was truncated");
8649 goto done_agent_query;
8651 bloblen = toint(GET_32BIT(q));
8652 if (bloblen < 0 || bloblen > lenleft) {
8653 logeventf(ssh, "Pageant response was truncated");
8655 goto done_agent_query;
8657 lenleft -= 4 + bloblen;
8659 commentlen = toint(GET_32BIT(q));
8660 if (commentlen < 0 || commentlen > lenleft) {
8661 logeventf(ssh, "Pageant response was truncated");
8663 goto done_agent_query;
8665 lenleft -= 4 + commentlen;
8666 q += 4 + commentlen;
8671 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
8672 if (s->publickey_blob) {
8673 /* See if configured key is in agent. */
8674 for (keyi = 0; keyi < s->nkeys; keyi++) {
8675 s->pklen = toint(GET_32BIT(p));
8676 if (s->pklen == s->publickey_bloblen &&
8677 !memcmp(p+4, s->publickey_blob,
8678 s->publickey_bloblen)) {
8679 logeventf(ssh, "Pageant key #%d matches "
8680 "configured key file", keyi);
8682 s->pkblob_in_agent = p;
8686 p += toint(GET_32BIT(p)) + 4; /* comment */
8688 if (!s->pkblob_in_agent) {
8689 logevent("Configured key file not in Pageant");
8694 logevent("Failed to get reply from Pageant");
8702 * We repeat this whole loop, including the username prompt,
8703 * until we manage a successful authentication. If the user
8704 * types the wrong _password_, they can be sent back to the
8705 * beginning to try another username, if this is configured on.
8706 * (If they specify a username in the config, they are never
8707 * asked, even if they do give a wrong password.)
8709 * I think this best serves the needs of
8711 * - the people who have no configuration, no keys, and just
8712 * want to try repeated (username,password) pairs until they
8713 * type both correctly
8715 * - people who have keys and configuration but occasionally
8716 * need to fall back to passwords
8718 * - people with a key held in Pageant, who might not have
8719 * logged in to a particular machine before; so they want to
8720 * type a username, and then _either_ their key will be
8721 * accepted, _or_ they will type a password. If they mistype
8722 * the username they will want to be able to get back and
8725 s->got_username = FALSE;
8726 while (!s->we_are_in) {
8730 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
8732 * We got a username last time round this loop, and
8733 * with change_username turned off we don't try to get
8736 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
8737 int ret; /* need not be kept over crReturn */
8738 s->cur_prompt = new_prompts(ssh->frontend);
8739 s->cur_prompt->to_server = TRUE;
8740 s->cur_prompt->name = dupstr("SSH login name");
8741 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
8742 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8745 crWaitUntilV(!pktin);
8746 ret = get_userpass_input(s->cur_prompt, in, inlen);
8751 * get_userpass_input() failed to get a username.
8754 free_prompts(s->cur_prompt);
8755 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
8758 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
8759 free_prompts(s->cur_prompt);
8762 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
8763 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
8764 c_write_str(ssh, stuff);
8768 s->got_username = TRUE;
8771 * Send an authentication request using method "none": (a)
8772 * just in case it succeeds, and (b) so that we know what
8773 * authentication methods we can usefully try next.
8775 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
8777 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8778 ssh2_pkt_addstring(s->pktout, ssh->username);
8779 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
8780 ssh2_pkt_addstring(s->pktout, "none"); /* method */
8781 ssh2_pkt_send(ssh, s->pktout);
8782 s->type = AUTH_TYPE_NONE;
8784 s->we_are_in = FALSE;
8786 s->tried_pubkey_config = FALSE;
8787 s->kbd_inter_refused = FALSE;
8789 /* Reset agent request state. */
8790 s->done_agent = FALSE;
8791 if (s->agent_response) {
8792 if (s->pkblob_in_agent) {
8793 s->agentp = s->pkblob_in_agent;
8795 s->agentp = s->agent_response + 5 + 4;
8801 char *methods = NULL;
8805 * Wait for the result of the last authentication request.
8808 crWaitUntilV(pktin);
8810 * Now is a convenient point to spew any banner material
8811 * that we've accumulated. (This should ensure that when
8812 * we exit the auth loop, we haven't any left to deal
8816 int size = bufchain_size(&ssh->banner);
8818 * Don't show the banner if we're operating in
8819 * non-verbose non-interactive mode. (It's probably
8820 * a script, which means nobody will read the
8821 * banner _anyway_, and moreover the printing of
8822 * the banner will screw up processing on the
8823 * output of (say) plink.)
8825 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
8826 char *banner = snewn(size, char);
8827 bufchain_fetch(&ssh->banner, banner, size);
8828 c_write_untrusted(ssh, banner, size);
8831 bufchain_clear(&ssh->banner);
8833 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
8834 logevent("Access granted");
8835 s->we_are_in = s->userauth_success = TRUE;
8839 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
8840 bombout(("Strange packet received during authentication: "
8841 "type %d", pktin->type));
8848 * OK, we're now sitting on a USERAUTH_FAILURE message, so
8849 * we can look at the string in it and know what we can
8850 * helpfully try next.
8852 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
8853 ssh_pkt_getstring(pktin, &methods, &methlen);
8854 if (!ssh2_pkt_getbool(pktin)) {
8856 * We have received an unequivocal Access
8857 * Denied. This can translate to a variety of
8858 * messages, or no message at all.
8860 * For forms of authentication which are attempted
8861 * implicitly, by which I mean without printing
8862 * anything in the window indicating that we're
8863 * trying them, we should never print 'Access
8866 * If we do print a message saying that we're
8867 * attempting some kind of authentication, it's OK
8868 * to print a followup message saying it failed -
8869 * but the message may sometimes be more specific
8870 * than simply 'Access denied'.
8872 * Additionally, if we'd just tried password
8873 * authentication, we should break out of this
8874 * whole loop so as to go back to the username
8875 * prompt (iff we're configured to allow
8876 * username change attempts).
8878 if (s->type == AUTH_TYPE_NONE) {
8880 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
8881 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
8882 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
8883 c_write_str(ssh, "Server refused our key\r\n");
8884 logevent("Server refused our key");
8885 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
8886 /* This _shouldn't_ happen except by a
8887 * protocol bug causing client and server to
8888 * disagree on what is a correct signature. */
8889 c_write_str(ssh, "Server refused public-key signature"
8890 " despite accepting key!\r\n");
8891 logevent("Server refused public-key signature"
8892 " despite accepting key!");
8893 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
8894 /* quiet, so no c_write */
8895 logevent("Server refused keyboard-interactive authentication");
8896 } else if (s->type==AUTH_TYPE_GSSAPI) {
8897 /* always quiet, so no c_write */
8898 /* also, the code down in the GSSAPI block has
8899 * already logged this in the Event Log */
8900 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
8901 logevent("Keyboard-interactive authentication failed");
8902 c_write_str(ssh, "Access denied\r\n");
8904 assert(s->type == AUTH_TYPE_PASSWORD);
8905 logevent("Password authentication failed");
8906 c_write_str(ssh, "Access denied\r\n");
8908 if (conf_get_int(ssh->conf, CONF_change_username)) {
8909 /* XXX perhaps we should allow
8910 * keyboard-interactive to do this too? */
8911 s->we_are_in = FALSE;
8916 c_write_str(ssh, "Further authentication required\r\n");
8917 logevent("Further authentication required");
8921 in_commasep_string("publickey", methods, methlen);
8923 in_commasep_string("password", methods, methlen);
8924 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
8925 in_commasep_string("keyboard-interactive", methods, methlen);
8928 ssh->gsslibs = ssh_gss_setup(ssh->conf);
8929 s->can_gssapi = conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
8930 in_commasep_string("gssapi-with-mic", methods, methlen) &&
8931 ssh->gsslibs->nlibraries > 0;
8935 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
8937 if (s->can_pubkey && !s->done_agent && s->nkeys) {
8940 * Attempt public-key authentication using a key from Pageant.
8943 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
8945 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
8947 /* Unpack key from agent response */
8948 s->pklen = toint(GET_32BIT(s->agentp));
8950 s->pkblob = (char *)s->agentp;
8951 s->agentp += s->pklen;
8952 s->alglen = toint(GET_32BIT(s->pkblob));
8953 s->alg = s->pkblob + 4;
8954 s->commentlen = toint(GET_32BIT(s->agentp));
8956 s->commentp = (char *)s->agentp;
8957 s->agentp += s->commentlen;
8958 /* s->agentp now points at next key, if any */
8960 /* See if server will accept it */
8961 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8962 ssh2_pkt_addstring(s->pktout, ssh->username);
8963 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8964 /* service requested */
8965 ssh2_pkt_addstring(s->pktout, "publickey");
8967 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
8968 ssh2_pkt_addstring_start(s->pktout);
8969 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
8970 ssh2_pkt_addstring_start(s->pktout);
8971 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
8972 ssh2_pkt_send(ssh, s->pktout);
8973 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
8975 crWaitUntilV(pktin);
8976 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
8978 /* Offer of key refused. */
8985 if (flags & FLAG_VERBOSE) {
8986 c_write_str(ssh, "Authenticating with "
8988 c_write(ssh, s->commentp, s->commentlen);
8989 c_write_str(ssh, "\" from agent\r\n");
8993 * Server is willing to accept the key.
8994 * Construct a SIGN_REQUEST.
8996 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8997 ssh2_pkt_addstring(s->pktout, ssh->username);
8998 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8999 /* service requested */
9000 ssh2_pkt_addstring(s->pktout, "publickey");
9002 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
9003 ssh2_pkt_addstring_start(s->pktout);
9004 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9005 ssh2_pkt_addstring_start(s->pktout);
9006 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9008 /* Ask agent for signature. */
9009 s->siglen = s->pktout->length - 5 + 4 +
9010 ssh->v2_session_id_len;
9011 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9013 s->len = 1; /* message type */
9014 s->len += 4 + s->pklen; /* key blob */
9015 s->len += 4 + s->siglen; /* data to sign */
9016 s->len += 4; /* flags */
9017 s->agentreq = snewn(4 + s->len, char);
9018 PUT_32BIT(s->agentreq, s->len);
9019 s->q = s->agentreq + 4;
9020 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
9021 PUT_32BIT(s->q, s->pklen);
9023 memcpy(s->q, s->pkblob, s->pklen);
9025 PUT_32BIT(s->q, s->siglen);
9027 /* Now the data to be signed... */
9028 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9029 PUT_32BIT(s->q, ssh->v2_session_id_len);
9032 memcpy(s->q, ssh->v2_session_id,
9033 ssh->v2_session_id_len);
9034 s->q += ssh->v2_session_id_len;
9035 memcpy(s->q, s->pktout->data + 5,
9036 s->pktout->length - 5);
9037 s->q += s->pktout->length - 5;
9038 /* And finally the (zero) flags word. */
9040 if (!agent_query(s->agentreq, s->len + 4,
9042 ssh_agent_callback, ssh)) {
9046 bombout(("Unexpected data from server"
9047 " while waiting for agent"
9051 } while (pktin || inlen > 0);
9052 vret = ssh->agent_response;
9053 s->retlen = ssh->agent_response_len;
9058 if (s->retlen >= 9 &&
9059 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
9060 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
9061 logevent("Sending Pageant's response");
9062 ssh2_add_sigblob(ssh, s->pktout,
9063 s->pkblob, s->pklen,
9065 GET_32BIT(s->ret + 5));
9066 ssh2_pkt_send(ssh, s->pktout);
9067 s->type = AUTH_TYPE_PUBLICKEY;
9069 /* FIXME: less drastic response */
9070 bombout(("Pageant failed to answer challenge"));
9076 /* Do we have any keys left to try? */
9077 if (s->pkblob_in_agent) {
9078 s->done_agent = TRUE;
9079 s->tried_pubkey_config = TRUE;
9082 if (s->keyi >= s->nkeys)
9083 s->done_agent = TRUE;
9086 } else if (s->can_pubkey && s->publickey_blob &&
9087 !s->tried_pubkey_config) {
9089 struct ssh2_userkey *key; /* not live over crReturn */
9090 char *passphrase; /* not live over crReturn */
9092 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9094 s->tried_pubkey_config = TRUE;
9097 * Try the public key supplied in the configuration.
9099 * First, offer the public blob to see if the server is
9100 * willing to accept it.
9102 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9103 ssh2_pkt_addstring(s->pktout, ssh->username);
9104 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9105 /* service requested */
9106 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
9107 ssh2_pkt_addbool(s->pktout, FALSE);
9108 /* no signature included */
9109 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
9110 ssh2_pkt_addstring_start(s->pktout);
9111 ssh2_pkt_addstring_data(s->pktout,
9112 (char *)s->publickey_blob,
9113 s->publickey_bloblen);
9114 ssh2_pkt_send(ssh, s->pktout);
9115 logevent("Offered public key");
9117 crWaitUntilV(pktin);
9118 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9119 /* Key refused. Give up. */
9120 s->gotit = TRUE; /* reconsider message next loop */
9121 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
9122 continue; /* process this new message */
9124 logevent("Offer of public key accepted");
9127 * Actually attempt a serious authentication using
9130 if (flags & FLAG_VERBOSE) {
9131 c_write_str(ssh, "Authenticating with public key \"");
9132 c_write_str(ssh, s->publickey_comment);
9133 c_write_str(ssh, "\"\r\n");
9137 const char *error; /* not live over crReturn */
9138 if (s->publickey_encrypted) {
9140 * Get a passphrase from the user.
9142 int ret; /* need not be kept over crReturn */
9143 s->cur_prompt = new_prompts(ssh->frontend);
9144 s->cur_prompt->to_server = FALSE;
9145 s->cur_prompt->name = dupstr("SSH key passphrase");
9146 add_prompt(s->cur_prompt,
9147 dupprintf("Passphrase for key \"%.100s\": ",
9148 s->publickey_comment),
9150 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9153 crWaitUntilV(!pktin);
9154 ret = get_userpass_input(s->cur_prompt,
9159 /* Failed to get a passphrase. Terminate. */
9160 free_prompts(s->cur_prompt);
9161 ssh_disconnect(ssh, NULL,
9162 "Unable to authenticate",
9163 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9168 dupstr(s->cur_prompt->prompts[0]->result);
9169 free_prompts(s->cur_prompt);
9171 passphrase = NULL; /* no passphrase needed */
9175 * Try decrypting the key.
9177 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9178 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
9180 /* burn the evidence */
9181 smemclr(passphrase, strlen(passphrase));
9184 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
9186 (key == SSH2_WRONG_PASSPHRASE)) {
9187 c_write_str(ssh, "Wrong passphrase\r\n");
9189 /* and loop again */
9191 c_write_str(ssh, "Unable to load private key (");
9192 c_write_str(ssh, error);
9193 c_write_str(ssh, ")\r\n");
9195 break; /* try something else */
9201 unsigned char *pkblob, *sigblob, *sigdata;
9202 int pkblob_len, sigblob_len, sigdata_len;
9206 * We have loaded the private key and the server
9207 * has announced that it's willing to accept it.
9208 * Hallelujah. Generate a signature and send it.
9210 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9211 ssh2_pkt_addstring(s->pktout, ssh->username);
9212 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9213 /* service requested */
9214 ssh2_pkt_addstring(s->pktout, "publickey");
9216 ssh2_pkt_addbool(s->pktout, TRUE);
9217 /* signature follows */
9218 ssh2_pkt_addstring(s->pktout, key->alg->name);
9219 pkblob = key->alg->public_blob(key->data,
9221 ssh2_pkt_addstring_start(s->pktout);
9222 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
9226 * The data to be signed is:
9230 * followed by everything so far placed in the
9233 sigdata_len = s->pktout->length - 5 + 4 +
9234 ssh->v2_session_id_len;
9235 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9237 sigdata = snewn(sigdata_len, unsigned char);
9239 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9240 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
9243 memcpy(sigdata+p, ssh->v2_session_id,
9244 ssh->v2_session_id_len);
9245 p += ssh->v2_session_id_len;
9246 memcpy(sigdata+p, s->pktout->data + 5,
9247 s->pktout->length - 5);
9248 p += s->pktout->length - 5;
9249 assert(p == sigdata_len);
9250 sigblob = key->alg->sign(key->data, (char *)sigdata,
9251 sigdata_len, &sigblob_len);
9252 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
9253 sigblob, sigblob_len);
9258 ssh2_pkt_send(ssh, s->pktout);
9259 logevent("Sent public key signature");
9260 s->type = AUTH_TYPE_PUBLICKEY;
9261 key->alg->freekey(key->data);
9265 } else if (s->can_gssapi && !s->tried_gssapi) {
9267 /* GSSAPI Authentication */
9272 s->type = AUTH_TYPE_GSSAPI;
9273 s->tried_gssapi = TRUE;
9275 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
9278 * Pick the highest GSS library on the preference
9284 for (i = 0; i < ngsslibs; i++) {
9285 int want_id = conf_get_int_int(ssh->conf,
9286 CONF_ssh_gsslist, i);
9287 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
9288 if (ssh->gsslibs->libraries[j].id == want_id) {
9289 s->gsslib = &ssh->gsslibs->libraries[j];
9290 goto got_gsslib; /* double break */
9295 * We always expect to have found something in
9296 * the above loop: we only came here if there
9297 * was at least one viable GSS library, and the
9298 * preference list should always mention
9299 * everything and only change the order.
9304 if (s->gsslib->gsslogmsg)
9305 logevent(s->gsslib->gsslogmsg);
9307 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
9308 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9309 ssh2_pkt_addstring(s->pktout, ssh->username);
9310 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9311 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
9312 logevent("Attempting GSSAPI authentication");
9314 /* add mechanism info */
9315 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
9317 /* number of GSSAPI mechanisms */
9318 ssh2_pkt_adduint32(s->pktout,1);
9320 /* length of OID + 2 */
9321 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
9322 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
9325 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
9327 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
9329 ssh2_pkt_send(ssh, s->pktout);
9330 crWaitUntilV(pktin);
9331 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
9332 logevent("GSSAPI authentication request refused");
9336 /* check returned packet ... */
9338 ssh_pkt_getstring(pktin, &data, &len);
9339 s->gss_rcvtok.value = data;
9340 s->gss_rcvtok.length = len;
9341 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
9342 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
9343 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
9344 memcmp((char *)s->gss_rcvtok.value + 2,
9345 s->gss_buf.value,s->gss_buf.length) ) {
9346 logevent("GSSAPI authentication - wrong response from server");
9350 /* now start running */
9351 s->gss_stat = s->gsslib->import_name(s->gsslib,
9354 if (s->gss_stat != SSH_GSS_OK) {
9355 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
9356 logevent("GSSAPI import name failed - Bad service name");
9358 logevent("GSSAPI import name failed");
9362 /* fetch TGT into GSS engine */
9363 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
9365 if (s->gss_stat != SSH_GSS_OK) {
9366 logevent("GSSAPI authentication failed to get credentials");
9367 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9371 /* initial tokens are empty */
9372 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
9373 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
9375 /* now enter the loop */
9377 s->gss_stat = s->gsslib->init_sec_context
9381 conf_get_int(ssh->conf, CONF_gssapifwd),
9385 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
9386 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
9387 logevent("GSSAPI authentication initialisation failed");
9389 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
9390 &s->gss_buf) == SSH_GSS_OK) {
9391 logevent(s->gss_buf.value);
9392 sfree(s->gss_buf.value);
9397 logevent("GSSAPI authentication initialised");
9399 /* Client and server now exchange tokens until GSSAPI
9400 * no longer says CONTINUE_NEEDED */
9402 if (s->gss_sndtok.length != 0) {
9403 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
9404 ssh_pkt_addstring_start(s->pktout);
9405 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
9406 ssh2_pkt_send(ssh, s->pktout);
9407 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
9410 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
9411 crWaitUntilV(pktin);
9412 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
9413 logevent("GSSAPI authentication - bad server response");
9414 s->gss_stat = SSH_GSS_FAILURE;
9417 ssh_pkt_getstring(pktin, &data, &len);
9418 s->gss_rcvtok.value = data;
9419 s->gss_rcvtok.length = len;
9421 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
9423 if (s->gss_stat != SSH_GSS_OK) {
9424 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9425 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9428 logevent("GSSAPI authentication loop finished OK");
9430 /* Now send the MIC */
9432 s->pktout = ssh2_pkt_init(0);
9433 micoffset = s->pktout->length;
9434 ssh_pkt_addstring_start(s->pktout);
9435 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
9436 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
9437 ssh_pkt_addstring(s->pktout, ssh->username);
9438 ssh_pkt_addstring(s->pktout, "ssh-connection");
9439 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
9441 s->gss_buf.value = (char *)s->pktout->data + micoffset;
9442 s->gss_buf.length = s->pktout->length - micoffset;
9444 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
9445 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
9446 ssh_pkt_addstring_start(s->pktout);
9447 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
9448 ssh2_pkt_send(ssh, s->pktout);
9449 s->gsslib->free_mic(s->gsslib, &mic);
9453 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9454 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9457 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
9460 * Keyboard-interactive authentication.
9463 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
9465 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
9467 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9468 ssh2_pkt_addstring(s->pktout, ssh->username);
9469 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9470 /* service requested */
9471 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
9473 ssh2_pkt_addstring(s->pktout, ""); /* lang */
9474 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
9475 ssh2_pkt_send(ssh, s->pktout);
9477 logevent("Attempting keyboard-interactive authentication");
9479 crWaitUntilV(pktin);
9480 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
9481 /* Server is not willing to do keyboard-interactive
9482 * at all (or, bizarrely but legally, accepts the
9483 * user without actually issuing any prompts).
9484 * Give up on it entirely. */
9486 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
9487 s->kbd_inter_refused = TRUE; /* don't try it again */
9492 * Loop while the server continues to send INFO_REQUESTs.
9494 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
9496 char *name, *inst, *lang;
9497 int name_len, inst_len, lang_len;
9501 * We've got a fresh USERAUTH_INFO_REQUEST.
9502 * Get the preamble and start building a prompt.
9504 ssh_pkt_getstring(pktin, &name, &name_len);
9505 ssh_pkt_getstring(pktin, &inst, &inst_len);
9506 ssh_pkt_getstring(pktin, &lang, &lang_len);
9507 s->cur_prompt = new_prompts(ssh->frontend);
9508 s->cur_prompt->to_server = TRUE;
9511 * Get any prompt(s) from the packet.
9513 s->num_prompts = ssh_pkt_getuint32(pktin);
9514 for (i = 0; i < s->num_prompts; i++) {
9518 static char noprompt[] =
9519 "<server failed to send prompt>: ";
9521 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9522 echo = ssh2_pkt_getbool(pktin);
9525 prompt_len = lenof(noprompt)-1;
9527 add_prompt(s->cur_prompt,
9528 dupprintf("%.*s", prompt_len, prompt),
9533 /* FIXME: better prefix to distinguish from
9535 s->cur_prompt->name =
9536 dupprintf("SSH server: %.*s", name_len, name);
9537 s->cur_prompt->name_reqd = TRUE;
9539 s->cur_prompt->name =
9540 dupstr("SSH server authentication");
9541 s->cur_prompt->name_reqd = FALSE;
9543 /* We add a prefix to try to make it clear that a prompt
9544 * has come from the server.
9545 * FIXME: ugly to print "Using..." in prompt _every_
9546 * time round. Can this be done more subtly? */
9547 /* Special case: for reasons best known to themselves,
9548 * some servers send k-i requests with no prompts and
9549 * nothing to display. Keep quiet in this case. */
9550 if (s->num_prompts || name_len || inst_len) {
9551 s->cur_prompt->instruction =
9552 dupprintf("Using keyboard-interactive authentication.%s%.*s",
9553 inst_len ? "\n" : "", inst_len, inst);
9554 s->cur_prompt->instr_reqd = TRUE;
9556 s->cur_prompt->instr_reqd = FALSE;
9560 * Display any instructions, and get the user's
9564 int ret; /* not live over crReturn */
9565 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9568 crWaitUntilV(!pktin);
9569 ret = get_userpass_input(s->cur_prompt, in, inlen);
9574 * Failed to get responses. Terminate.
9576 free_prompts(s->cur_prompt);
9577 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9578 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9585 * Send the response(s) to the server.
9587 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
9588 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
9589 for (i=0; i < s->num_prompts; i++) {
9590 ssh2_pkt_addstring(s->pktout,
9591 s->cur_prompt->prompts[i]->result);
9593 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9596 * Free the prompts structure from this iteration.
9597 * If there's another, a new one will be allocated
9598 * when we return to the top of this while loop.
9600 free_prompts(s->cur_prompt);
9603 * Get the next packet in case it's another
9606 crWaitUntilV(pktin);
9611 * We should have SUCCESS or FAILURE now.
9615 } else if (s->can_passwd) {
9618 * Plain old password authentication.
9620 int ret; /* not live over crReturn */
9621 int changereq_first_time; /* not live over crReturn */
9623 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
9625 s->cur_prompt = new_prompts(ssh->frontend);
9626 s->cur_prompt->to_server = TRUE;
9627 s->cur_prompt->name = dupstr("SSH password");
9628 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
9633 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9636 crWaitUntilV(!pktin);
9637 ret = get_userpass_input(s->cur_prompt, in, inlen);
9642 * Failed to get responses. Terminate.
9644 free_prompts(s->cur_prompt);
9645 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9646 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9651 * Squirrel away the password. (We may need it later if
9652 * asked to change it.)
9654 s->password = dupstr(s->cur_prompt->prompts[0]->result);
9655 free_prompts(s->cur_prompt);
9658 * Send the password packet.
9660 * We pad out the password packet to 256 bytes to make
9661 * it harder for an attacker to find the length of the
9664 * Anyone using a password longer than 256 bytes
9665 * probably doesn't have much to worry about from
9666 * people who find out how long their password is!
9668 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9669 ssh2_pkt_addstring(s->pktout, ssh->username);
9670 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9671 /* service requested */
9672 ssh2_pkt_addstring(s->pktout, "password");
9673 ssh2_pkt_addbool(s->pktout, FALSE);
9674 ssh2_pkt_addstring(s->pktout, s->password);
9675 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9676 logevent("Sent password");
9677 s->type = AUTH_TYPE_PASSWORD;
9680 * Wait for next packet, in case it's a password change
9683 crWaitUntilV(pktin);
9684 changereq_first_time = TRUE;
9686 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
9689 * We're being asked for a new password
9690 * (perhaps not for the first time).
9691 * Loop until the server accepts it.
9694 int got_new = FALSE; /* not live over crReturn */
9695 char *prompt; /* not live over crReturn */
9696 int prompt_len; /* not live over crReturn */
9700 if (changereq_first_time)
9701 msg = "Server requested password change";
9703 msg = "Server rejected new password";
9705 c_write_str(ssh, msg);
9706 c_write_str(ssh, "\r\n");
9709 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9711 s->cur_prompt = new_prompts(ssh->frontend);
9712 s->cur_prompt->to_server = TRUE;
9713 s->cur_prompt->name = dupstr("New SSH password");
9714 s->cur_prompt->instruction =
9715 dupprintf("%.*s", prompt_len, prompt);
9716 s->cur_prompt->instr_reqd = TRUE;
9718 * There's no explicit requirement in the protocol
9719 * for the "old" passwords in the original and
9720 * password-change messages to be the same, and
9721 * apparently some Cisco kit supports password change
9722 * by the user entering a blank password originally
9723 * and the real password subsequently, so,
9724 * reluctantly, we prompt for the old password again.
9726 * (On the other hand, some servers don't even bother
9727 * to check this field.)
9729 add_prompt(s->cur_prompt,
9730 dupstr("Current password (blank for previously entered password): "),
9732 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
9734 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
9738 * Loop until the user manages to enter the same
9743 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9746 crWaitUntilV(!pktin);
9747 ret = get_userpass_input(s->cur_prompt, in, inlen);
9752 * Failed to get responses. Terminate.
9754 /* burn the evidence */
9755 free_prompts(s->cur_prompt);
9756 smemclr(s->password, strlen(s->password));
9758 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9759 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9765 * If the user specified a new original password
9766 * (IYSWIM), overwrite any previously specified
9768 * (A side effect is that the user doesn't have to
9769 * re-enter it if they louse up the new password.)
9771 if (s->cur_prompt->prompts[0]->result[0]) {
9772 smemclr(s->password, strlen(s->password));
9773 /* burn the evidence */
9776 dupstr(s->cur_prompt->prompts[0]->result);
9780 * Check the two new passwords match.
9782 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
9783 s->cur_prompt->prompts[2]->result)
9786 /* They don't. Silly user. */
9787 c_write_str(ssh, "Passwords do not match\r\n");
9792 * Send the new password (along with the old one).
9793 * (see above for padding rationale)
9795 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9796 ssh2_pkt_addstring(s->pktout, ssh->username);
9797 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9798 /* service requested */
9799 ssh2_pkt_addstring(s->pktout, "password");
9800 ssh2_pkt_addbool(s->pktout, TRUE);
9801 ssh2_pkt_addstring(s->pktout, s->password);
9802 ssh2_pkt_addstring(s->pktout,
9803 s->cur_prompt->prompts[1]->result);
9804 free_prompts(s->cur_prompt);
9805 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9806 logevent("Sent new password");
9809 * Now see what the server has to say about it.
9810 * (If it's CHANGEREQ again, it's not happy with the
9813 crWaitUntilV(pktin);
9814 changereq_first_time = FALSE;
9819 * We need to reexamine the current pktin at the top
9820 * of the loop. Either:
9821 * - we weren't asked to change password at all, in
9822 * which case it's a SUCCESS or FAILURE with the
9824 * - we sent a new password, and the server was
9825 * either OK with it (SUCCESS or FAILURE w/partial
9826 * success) or unhappy with the _old_ password
9827 * (FAILURE w/o partial success)
9828 * In any of these cases, we go back to the top of
9829 * the loop and start again.
9834 * We don't need the old password any more, in any
9835 * case. Burn the evidence.
9837 smemclr(s->password, strlen(s->password));
9841 char *str = dupprintf("No supported authentication methods available"
9842 " (server sent: %.*s)",
9845 ssh_disconnect(ssh, str,
9846 "No supported authentication methods available",
9847 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
9857 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
9859 /* Clear up various bits and pieces from authentication. */
9860 if (s->publickey_blob) {
9861 sfree(s->publickey_blob);
9862 sfree(s->publickey_comment);
9864 if (s->agent_response)
9865 sfree(s->agent_response);
9867 if (s->userauth_success && !ssh->bare_connection) {
9869 * We've just received USERAUTH_SUCCESS, and we haven't sent any
9870 * packets since. Signal the transport layer to consider enacting
9871 * delayed compression.
9873 * (Relying on we_are_in is not sufficient, as
9874 * draft-miller-secsh-compression-delayed is quite clear that it
9875 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
9876 * become set for other reasons.)
9878 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
9881 ssh->channels = newtree234(ssh_channelcmp);
9884 * Set up handlers for some connection protocol messages, so we
9885 * don't have to handle them repeatedly in this coroutine.
9887 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
9888 ssh2_msg_channel_window_adjust;
9889 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
9890 ssh2_msg_global_request;
9893 * Create the main session channel.
9895 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
9896 ssh->mainchan = NULL;
9898 ssh->mainchan = snew(struct ssh_channel);
9899 ssh->mainchan->ssh = ssh;
9900 ssh2_channel_init(ssh->mainchan);
9902 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
9904 * Just start a direct-tcpip channel and use it as the main
9907 ssh_send_port_open(ssh->mainchan,
9908 conf_get_str(ssh->conf, CONF_ssh_nc_host),
9909 conf_get_int(ssh->conf, CONF_ssh_nc_port),
9913 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
9914 logevent("Opening session as main channel");
9915 ssh2_pkt_send(ssh, s->pktout);
9916 ssh->ncmode = FALSE;
9918 crWaitUntilV(pktin);
9919 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
9920 bombout(("Server refused to open channel"));
9922 /* FIXME: error data comes back in FAILURE packet */
9924 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
9925 bombout(("Server's channel confirmation cited wrong channel"));
9928 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
9929 ssh->mainchan->halfopen = FALSE;
9930 ssh->mainchan->type = CHAN_MAINSESSION;
9931 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
9932 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
9933 add234(ssh->channels, ssh->mainchan);
9934 update_specials_menu(ssh->frontend);
9935 logevent("Opened main channel");
9939 * Now we have a channel, make dispatch table entries for
9940 * general channel-based messages.
9942 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
9943 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
9944 ssh2_msg_channel_data;
9945 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
9946 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
9947 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
9948 ssh2_msg_channel_open_confirmation;
9949 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
9950 ssh2_msg_channel_open_failure;
9951 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
9952 ssh2_msg_channel_request;
9953 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
9954 ssh2_msg_channel_open;
9955 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
9956 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
9959 * Now the connection protocol is properly up and running, with
9960 * all those dispatch table entries, so it's safe to let
9961 * downstreams start trying to open extra channels through us.
9964 share_activate(ssh->connshare, ssh->v_s);
9966 if (ssh->mainchan && ssh_is_simple(ssh)) {
9968 * This message indicates to the server that we promise
9969 * not to try to run any other channel in parallel with
9970 * this one, so it's safe for it to advertise a very large
9971 * window and leave the flow control to TCP.
9973 s->pktout = ssh2_chanreq_init(ssh->mainchan,
9974 "simple@putty.projects.tartarus.org",
9976 ssh2_pkt_send(ssh, s->pktout);
9980 * Enable port forwardings.
9982 ssh_setup_portfwd(ssh, ssh->conf);
9984 if (ssh->mainchan && !ssh->ncmode) {
9986 * Send the CHANNEL_REQUESTS for the main session channel.
9987 * Each one is handled by its own little asynchronous
9991 /* Potentially enable X11 forwarding. */
9992 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
9994 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
9996 if (!ssh->x11disp) {
9997 /* FIXME: return an error message from x11_setup_display */
9998 logevent("X11 forwarding not enabled: unable to"
9999 " initialise X display");
10001 ssh->x11auth = x11_invent_fake_auth
10002 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
10003 ssh->x11auth->disp = ssh->x11disp;
10005 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
10009 /* Potentially enable agent forwarding. */
10010 if (ssh_agent_forwarding_permitted(ssh))
10011 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
10013 /* Now allocate a pty for the session. */
10014 if (!conf_get_int(ssh->conf, CONF_nopty))
10015 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
10017 /* Send environment variables. */
10018 ssh2_setup_env(ssh->mainchan, NULL, NULL);
10021 * Start a shell or a remote command. We may have to attempt
10022 * this twice if the config data has provided a second choice
10029 if (ssh->fallback_cmd) {
10030 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
10031 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
10033 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
10034 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
10038 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
10039 ssh2_response_authconn, NULL);
10040 ssh2_pkt_addstring(s->pktout, cmd);
10042 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
10043 ssh2_response_authconn, NULL);
10044 ssh2_pkt_addstring(s->pktout, cmd);
10046 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
10047 ssh2_response_authconn, NULL);
10049 ssh2_pkt_send(ssh, s->pktout);
10051 crWaitUntilV(pktin);
10053 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
10054 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
10055 bombout(("Unexpected response to shell/command request:"
10056 " packet type %d", pktin->type));
10060 * We failed to start the command. If this is the
10061 * fallback command, we really are finished; if it's
10062 * not, and if the fallback command exists, try falling
10063 * back to it before complaining.
10065 if (!ssh->fallback_cmd &&
10066 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
10067 logevent("Primary command failed; attempting fallback");
10068 ssh->fallback_cmd = TRUE;
10071 bombout(("Server refused to start a shell/command"));
10074 logevent("Started a shell/command");
10079 ssh->editing = ssh->echoing = TRUE;
10082 ssh->state = SSH_STATE_SESSION;
10083 if (ssh->size_needed)
10084 ssh_size(ssh, ssh->term_width, ssh->term_height);
10085 if (ssh->eof_needed)
10086 ssh_special(ssh, TS_EOF);
10092 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
10097 s->try_send = FALSE;
10101 * _All_ the connection-layer packets we expect to
10102 * receive are now handled by the dispatch table.
10103 * Anything that reaches here must be bogus.
10106 bombout(("Strange packet received: type %d", pktin->type));
10108 } else if (ssh->mainchan) {
10110 * We have spare data. Add it to the channel buffer.
10112 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
10113 s->try_send = TRUE;
10117 struct ssh_channel *c;
10119 * Try to send data on all channels if we can.
10121 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
10122 ssh2_try_send_and_unthrottle(ssh, c);
10130 * Handlers for SSH-2 messages that might arrive at any moment.
10132 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
10134 /* log reason code in disconnect message */
10136 int reason, msglen;
10138 reason = ssh_pkt_getuint32(pktin);
10139 ssh_pkt_getstring(pktin, &msg, &msglen);
10141 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
10142 buf = dupprintf("Received disconnect message (%s)",
10143 ssh2_disconnect_reasons[reason]);
10145 buf = dupprintf("Received disconnect message (unknown"
10146 " type %d)", reason);
10150 buf = dupprintf("Disconnection message text: %.*s",
10153 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
10155 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
10156 ssh2_disconnect_reasons[reason] : "unknown",
10161 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
10163 /* log the debug message */
10167 /* XXX maybe we should actually take notice of the return value */
10168 ssh2_pkt_getbool(pktin);
10169 ssh_pkt_getstring(pktin, &msg, &msglen);
10171 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
10174 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
10176 do_ssh2_transport(ssh, NULL, 0, pktin);
10180 * Called if we receive a packet that isn't allowed by the protocol.
10181 * This only applies to packets whose meaning PuTTY understands.
10182 * Entirely unknown packets are handled below.
10184 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
10186 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
10187 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
10189 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
10193 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
10195 struct Packet *pktout;
10196 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
10197 ssh2_pkt_adduint32(pktout, pktin->sequence);
10199 * UNIMPLEMENTED messages MUST appear in the same order as the
10200 * messages they respond to. Hence, never queue them.
10202 ssh2_pkt_send_noqueue(ssh, pktout);
10206 * Handle the top-level SSH-2 protocol.
10208 static void ssh2_protocol_setup(Ssh ssh)
10213 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10215 for (i = 0; i < 256; i++)
10216 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10219 * Initially, we only accept transport messages (and a few generic
10220 * ones). do_ssh2_authconn will add more when it starts.
10221 * Messages that are understood but not currently acceptable go to
10222 * ssh2_msg_unexpected.
10224 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10225 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
10226 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
10227 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
10228 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
10229 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
10230 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
10231 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
10232 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
10233 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
10234 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
10235 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
10236 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
10237 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
10238 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
10239 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
10240 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
10241 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
10242 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
10243 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10244 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10245 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10246 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10247 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10248 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10249 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10250 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10251 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10252 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10253 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10254 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10255 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10256 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10259 * These messages have a special handler from the start.
10261 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10262 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
10263 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10266 static void ssh2_bare_connection_protocol_setup(Ssh ssh)
10271 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10273 for (i = 0; i < 256; i++)
10274 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10277 * Initially, we set all ssh-connection messages to 'unexpected';
10278 * do_ssh2_authconn will fill things in properly. We also handle a
10279 * couple of messages from the transport protocol which aren't
10280 * related to key exchange (UNIMPLEMENTED, IGNORE, DEBUG,
10283 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10284 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10285 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10286 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10287 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10288 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10289 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10290 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10291 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10292 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10293 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10294 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10295 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10296 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10298 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10301 * These messages have a special handler from the start.
10303 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10304 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore;
10305 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10308 static void ssh2_timer(void *ctx, unsigned long now)
10310 Ssh ssh = (Ssh)ctx;
10312 if (ssh->state == SSH_STATE_CLOSED)
10315 if (!ssh->kex_in_progress && !ssh->bare_connection &&
10316 conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
10317 now == ssh->next_rekey) {
10318 do_ssh2_transport(ssh, "timeout", -1, NULL);
10322 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
10323 struct Packet *pktin)
10325 unsigned char *in = (unsigned char *)vin;
10326 if (ssh->state == SSH_STATE_CLOSED)
10330 ssh->incoming_data_size += pktin->encrypted_len;
10331 if (!ssh->kex_in_progress &&
10332 ssh->max_data_size != 0 &&
10333 ssh->incoming_data_size > ssh->max_data_size)
10334 do_ssh2_transport(ssh, "too much data received", -1, NULL);
10338 ssh->packet_dispatch[pktin->type](ssh, pktin);
10339 else if (!ssh->protocol_initial_phase_done)
10340 do_ssh2_transport(ssh, in, inlen, pktin);
10342 do_ssh2_authconn(ssh, in, inlen, pktin);
10345 static void ssh2_bare_connection_protocol(Ssh ssh, void *vin, int inlen,
10346 struct Packet *pktin)
10348 unsigned char *in = (unsigned char *)vin;
10349 if (ssh->state == SSH_STATE_CLOSED)
10353 ssh->packet_dispatch[pktin->type](ssh, pktin);
10355 do_ssh2_authconn(ssh, in, inlen, pktin);
10358 static void ssh_cache_conf_values(Ssh ssh)
10360 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
10364 * Called to set up the connection.
10366 * Returns an error message, or NULL on success.
10368 static const char *ssh_init(void *frontend_handle, void **backend_handle,
10369 Conf *conf, char *host, int port, char **realhost,
10370 int nodelay, int keepalive)
10375 ssh = snew(struct ssh_tag);
10376 ssh->conf = conf_copy(conf);
10377 ssh_cache_conf_values(ssh);
10378 ssh->version = 0; /* when not ready yet */
10380 ssh->cipher = NULL;
10381 ssh->v1_cipher_ctx = NULL;
10382 ssh->crcda_ctx = NULL;
10383 ssh->cscipher = NULL;
10384 ssh->cs_cipher_ctx = NULL;
10385 ssh->sccipher = NULL;
10386 ssh->sc_cipher_ctx = NULL;
10388 ssh->cs_mac_ctx = NULL;
10390 ssh->sc_mac_ctx = NULL;
10391 ssh->cscomp = NULL;
10392 ssh->cs_comp_ctx = NULL;
10393 ssh->sccomp = NULL;
10394 ssh->sc_comp_ctx = NULL;
10396 ssh->kex_ctx = NULL;
10397 ssh->hostkey = NULL;
10398 ssh->hostkey_str = NULL;
10399 ssh->exitcode = -1;
10400 ssh->close_expected = FALSE;
10401 ssh->clean_exit = FALSE;
10402 ssh->state = SSH_STATE_PREPACKET;
10403 ssh->size_needed = FALSE;
10404 ssh->eof_needed = FALSE;
10406 ssh->logctx = NULL;
10407 ssh->deferred_send_data = NULL;
10408 ssh->deferred_len = 0;
10409 ssh->deferred_size = 0;
10410 ssh->fallback_cmd = 0;
10411 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
10412 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
10413 ssh->x11disp = NULL;
10414 ssh->x11auth = NULL;
10415 ssh->x11authtree = newtree234(x11_authcmp);
10416 ssh->v1_compressing = FALSE;
10417 ssh->v2_outgoing_sequence = 0;
10418 ssh->ssh1_rdpkt_crstate = 0;
10419 ssh->ssh2_rdpkt_crstate = 0;
10420 ssh->ssh2_bare_rdpkt_crstate = 0;
10421 ssh->ssh_gotdata_crstate = 0;
10422 ssh->do_ssh1_connection_crstate = 0;
10423 ssh->do_ssh_init_state = NULL;
10424 ssh->do_ssh_connection_init_state = NULL;
10425 ssh->do_ssh1_login_state = NULL;
10426 ssh->do_ssh2_transport_state = NULL;
10427 ssh->do_ssh2_authconn_state = NULL;
10430 ssh->mainchan = NULL;
10431 ssh->throttled_all = 0;
10432 ssh->v1_stdout_throttling = 0;
10434 ssh->queuelen = ssh->queuesize = 0;
10435 ssh->queueing = FALSE;
10436 ssh->qhead = ssh->qtail = NULL;
10437 ssh->deferred_rekey_reason = NULL;
10438 bufchain_init(&ssh->queued_incoming_data);
10439 ssh->frozen = FALSE;
10440 ssh->username = NULL;
10441 ssh->sent_console_eof = FALSE;
10442 ssh->got_pty = FALSE;
10443 ssh->bare_connection = FALSE;
10444 ssh->attempting_connshare = FALSE;
10446 *backend_handle = ssh;
10449 if (crypto_startup() == 0)
10450 return "Microsoft high encryption pack not installed!";
10453 ssh->frontend = frontend_handle;
10454 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
10455 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
10457 ssh->channels = NULL;
10458 ssh->rportfwds = NULL;
10459 ssh->portfwds = NULL;
10464 ssh->conn_throttle_count = 0;
10465 ssh->overall_bufsize = 0;
10466 ssh->fallback_cmd = 0;
10468 ssh->protocol = NULL;
10470 ssh->protocol_initial_phase_done = FALSE;
10472 ssh->pinger = NULL;
10474 ssh->incoming_data_size = ssh->outgoing_data_size =
10475 ssh->deferred_data_size = 0L;
10476 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10477 CONF_ssh_rekey_data));
10478 ssh->kex_in_progress = FALSE;
10481 ssh->gsslibs = NULL;
10484 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
10493 static void ssh_free(void *handle)
10495 Ssh ssh = (Ssh) handle;
10496 struct ssh_channel *c;
10497 struct ssh_rportfwd *pf;
10498 struct X11FakeAuth *auth;
10500 if (ssh->v1_cipher_ctx)
10501 ssh->cipher->free_context(ssh->v1_cipher_ctx);
10502 if (ssh->cs_cipher_ctx)
10503 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
10504 if (ssh->sc_cipher_ctx)
10505 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
10506 if (ssh->cs_mac_ctx)
10507 ssh->csmac->free_context(ssh->cs_mac_ctx);
10508 if (ssh->sc_mac_ctx)
10509 ssh->scmac->free_context(ssh->sc_mac_ctx);
10510 if (ssh->cs_comp_ctx) {
10512 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
10514 zlib_compress_cleanup(ssh->cs_comp_ctx);
10516 if (ssh->sc_comp_ctx) {
10518 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
10520 zlib_decompress_cleanup(ssh->sc_comp_ctx);
10523 dh_cleanup(ssh->kex_ctx);
10524 sfree(ssh->savedhost);
10526 while (ssh->queuelen-- > 0)
10527 ssh_free_packet(ssh->queue[ssh->queuelen]);
10530 while (ssh->qhead) {
10531 struct queued_handler *qh = ssh->qhead;
10532 ssh->qhead = qh->next;
10535 ssh->qhead = ssh->qtail = NULL;
10537 if (ssh->channels) {
10538 while ((c = delpos234(ssh->channels, 0)) != NULL) {
10541 if (c->u.x11.xconn != NULL)
10542 x11_close(c->u.x11.xconn);
10544 case CHAN_SOCKDATA:
10545 case CHAN_SOCKDATA_DORMANT:
10546 if (c->u.pfd.pf != NULL)
10547 pfd_close(c->u.pfd.pf);
10550 if (ssh->version == 2) {
10551 struct outstanding_channel_request *ocr, *nocr;
10552 ocr = c->v.v2.chanreq_head;
10554 ocr->handler(c, NULL, ocr->ctx);
10559 bufchain_clear(&c->v.v2.outbuffer);
10563 freetree234(ssh->channels);
10564 ssh->channels = NULL;
10567 if (ssh->connshare)
10568 sharestate_free(ssh->connshare);
10570 if (ssh->rportfwds) {
10571 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
10573 freetree234(ssh->rportfwds);
10574 ssh->rportfwds = NULL;
10576 sfree(ssh->deferred_send_data);
10578 x11_free_display(ssh->x11disp);
10579 while ((auth = delpos234(ssh->x11authtree, 0)) != NULL)
10580 x11_free_fake_auth(auth);
10581 freetree234(ssh->x11authtree);
10582 sfree(ssh->do_ssh_init_state);
10583 sfree(ssh->do_ssh1_login_state);
10584 sfree(ssh->do_ssh2_transport_state);
10585 sfree(ssh->do_ssh2_authconn_state);
10588 sfree(ssh->fullhostname);
10589 sfree(ssh->hostkey_str);
10590 if (ssh->crcda_ctx) {
10591 crcda_free_context(ssh->crcda_ctx);
10592 ssh->crcda_ctx = NULL;
10595 ssh_do_close(ssh, TRUE);
10596 expire_timer_context(ssh);
10598 pinger_free(ssh->pinger);
10599 bufchain_clear(&ssh->queued_incoming_data);
10600 sfree(ssh->username);
10601 conf_free(ssh->conf);
10604 ssh_gss_cleanup(ssh->gsslibs);
10612 * Reconfigure the SSH backend.
10614 static void ssh_reconfig(void *handle, Conf *conf)
10616 Ssh ssh = (Ssh) handle;
10617 char *rekeying = NULL, rekey_mandatory = FALSE;
10618 unsigned long old_max_data_size;
10621 pinger_reconfig(ssh->pinger, ssh->conf, conf);
10623 ssh_setup_portfwd(ssh, conf);
10625 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
10626 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
10628 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
10629 unsigned long now = GETTICKCOUNT();
10631 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
10632 rekeying = "timeout shortened";
10634 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
10638 old_max_data_size = ssh->max_data_size;
10639 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10640 CONF_ssh_rekey_data));
10641 if (old_max_data_size != ssh->max_data_size &&
10642 ssh->max_data_size != 0) {
10643 if (ssh->outgoing_data_size > ssh->max_data_size ||
10644 ssh->incoming_data_size > ssh->max_data_size)
10645 rekeying = "data limit lowered";
10648 if (conf_get_int(ssh->conf, CONF_compression) !=
10649 conf_get_int(conf, CONF_compression)) {
10650 rekeying = "compression setting changed";
10651 rekey_mandatory = TRUE;
10654 for (i = 0; i < CIPHER_MAX; i++)
10655 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
10656 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
10657 rekeying = "cipher settings changed";
10658 rekey_mandatory = TRUE;
10660 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
10661 conf_get_int(conf, CONF_ssh2_des_cbc)) {
10662 rekeying = "cipher settings changed";
10663 rekey_mandatory = TRUE;
10666 conf_free(ssh->conf);
10667 ssh->conf = conf_copy(conf);
10668 ssh_cache_conf_values(ssh);
10670 if (!ssh->bare_connection && rekeying) {
10671 if (!ssh->kex_in_progress) {
10672 do_ssh2_transport(ssh, rekeying, -1, NULL);
10673 } else if (rekey_mandatory) {
10674 ssh->deferred_rekey_reason = rekeying;
10680 * Called to send data down the SSH connection.
10682 static int ssh_send(void *handle, char *buf, int len)
10684 Ssh ssh = (Ssh) handle;
10686 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10689 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
10691 return ssh_sendbuffer(ssh);
10695 * Called to query the current amount of buffered stdin data.
10697 static int ssh_sendbuffer(void *handle)
10699 Ssh ssh = (Ssh) handle;
10700 int override_value;
10702 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10706 * If the SSH socket itself has backed up, add the total backup
10707 * size on that to any individual buffer on the stdin channel.
10709 override_value = 0;
10710 if (ssh->throttled_all)
10711 override_value = ssh->overall_bufsize;
10713 if (ssh->version == 1) {
10714 return override_value;
10715 } else if (ssh->version == 2) {
10716 if (!ssh->mainchan)
10717 return override_value;
10719 return (override_value +
10720 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
10727 * Called to set the size of the window from SSH's POV.
10729 static void ssh_size(void *handle, int width, int height)
10731 Ssh ssh = (Ssh) handle;
10732 struct Packet *pktout;
10734 ssh->term_width = width;
10735 ssh->term_height = height;
10737 switch (ssh->state) {
10738 case SSH_STATE_BEFORE_SIZE:
10739 case SSH_STATE_PREPACKET:
10740 case SSH_STATE_CLOSED:
10741 break; /* do nothing */
10742 case SSH_STATE_INTERMED:
10743 ssh->size_needed = TRUE; /* buffer for later */
10745 case SSH_STATE_SESSION:
10746 if (!conf_get_int(ssh->conf, CONF_nopty)) {
10747 if (ssh->version == 1) {
10748 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
10749 PKT_INT, ssh->term_height,
10750 PKT_INT, ssh->term_width,
10751 PKT_INT, 0, PKT_INT, 0, PKT_END);
10752 } else if (ssh->mainchan) {
10753 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
10755 ssh2_pkt_adduint32(pktout, ssh->term_width);
10756 ssh2_pkt_adduint32(pktout, ssh->term_height);
10757 ssh2_pkt_adduint32(pktout, 0);
10758 ssh2_pkt_adduint32(pktout, 0);
10759 ssh2_pkt_send(ssh, pktout);
10767 * Return a list of the special codes that make sense in this
10770 static const struct telnet_special *ssh_get_specials(void *handle)
10772 static const struct telnet_special ssh1_ignore_special[] = {
10773 {"IGNORE message", TS_NOP}
10775 static const struct telnet_special ssh2_ignore_special[] = {
10776 {"IGNORE message", TS_NOP},
10778 static const struct telnet_special ssh2_rekey_special[] = {
10779 {"Repeat key exchange", TS_REKEY},
10781 static const struct telnet_special ssh2_session_specials[] = {
10784 /* These are the signal names defined by RFC 4254.
10785 * They include all the ISO C signals, but are a subset of the POSIX
10786 * required signals. */
10787 {"SIGINT (Interrupt)", TS_SIGINT},
10788 {"SIGTERM (Terminate)", TS_SIGTERM},
10789 {"SIGKILL (Kill)", TS_SIGKILL},
10790 {"SIGQUIT (Quit)", TS_SIGQUIT},
10791 {"SIGHUP (Hangup)", TS_SIGHUP},
10792 {"More signals", TS_SUBMENU},
10793 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
10794 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
10795 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
10796 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
10797 {NULL, TS_EXITMENU}
10799 static const struct telnet_special specials_end[] = {
10800 {NULL, TS_EXITMENU}
10802 /* XXX review this length for any changes: */
10803 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
10804 lenof(ssh2_rekey_special) +
10805 lenof(ssh2_session_specials) +
10806 lenof(specials_end)];
10807 Ssh ssh = (Ssh) handle;
10809 #define ADD_SPECIALS(name) \
10811 assert((i + lenof(name)) <= lenof(ssh_specials)); \
10812 memcpy(&ssh_specials[i], name, sizeof name); \
10813 i += lenof(name); \
10816 if (ssh->version == 1) {
10817 /* Don't bother offering IGNORE if we've decided the remote
10818 * won't cope with it, since we wouldn't bother sending it if
10820 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
10821 ADD_SPECIALS(ssh1_ignore_special);
10822 } else if (ssh->version == 2) {
10823 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
10824 ADD_SPECIALS(ssh2_ignore_special);
10825 if (!(ssh->remote_bugs & BUG_SSH2_REKEY) && !ssh->bare_connection)
10826 ADD_SPECIALS(ssh2_rekey_special);
10828 ADD_SPECIALS(ssh2_session_specials);
10829 } /* else we're not ready yet */
10832 ADD_SPECIALS(specials_end);
10833 return ssh_specials;
10837 #undef ADD_SPECIALS
10841 * Send special codes. TS_EOF is useful for `plink', so you
10842 * can send an EOF and collect resulting output (e.g. `plink
10845 static void ssh_special(void *handle, Telnet_Special code)
10847 Ssh ssh = (Ssh) handle;
10848 struct Packet *pktout;
10850 if (code == TS_EOF) {
10851 if (ssh->state != SSH_STATE_SESSION) {
10853 * Buffer the EOF in case we are pre-SESSION, so we can
10854 * send it as soon as we reach SESSION.
10856 if (code == TS_EOF)
10857 ssh->eof_needed = TRUE;
10860 if (ssh->version == 1) {
10861 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
10862 } else if (ssh->mainchan) {
10863 sshfwd_write_eof(ssh->mainchan);
10864 ssh->send_ok = 0; /* now stop trying to read from stdin */
10866 logevent("Sent EOF message");
10867 } else if (code == TS_PING || code == TS_NOP) {
10868 if (ssh->state == SSH_STATE_CLOSED
10869 || ssh->state == SSH_STATE_PREPACKET) return;
10870 if (ssh->version == 1) {
10871 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
10872 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
10874 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
10875 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
10876 ssh2_pkt_addstring_start(pktout);
10877 ssh2_pkt_send_noqueue(ssh, pktout);
10880 } else if (code == TS_REKEY) {
10881 if (!ssh->kex_in_progress && !ssh->bare_connection &&
10882 ssh->version == 2) {
10883 do_ssh2_transport(ssh, "at user request", -1, NULL);
10885 } else if (code == TS_BRK) {
10886 if (ssh->state == SSH_STATE_CLOSED
10887 || ssh->state == SSH_STATE_PREPACKET) return;
10888 if (ssh->version == 1) {
10889 logevent("Unable to send BREAK signal in SSH-1");
10890 } else if (ssh->mainchan) {
10891 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
10892 ssh2_pkt_adduint32(pktout, 0); /* default break length */
10893 ssh2_pkt_send(ssh, pktout);
10896 /* Is is a POSIX signal? */
10897 char *signame = NULL;
10898 if (code == TS_SIGABRT) signame = "ABRT";
10899 if (code == TS_SIGALRM) signame = "ALRM";
10900 if (code == TS_SIGFPE) signame = "FPE";
10901 if (code == TS_SIGHUP) signame = "HUP";
10902 if (code == TS_SIGILL) signame = "ILL";
10903 if (code == TS_SIGINT) signame = "INT";
10904 if (code == TS_SIGKILL) signame = "KILL";
10905 if (code == TS_SIGPIPE) signame = "PIPE";
10906 if (code == TS_SIGQUIT) signame = "QUIT";
10907 if (code == TS_SIGSEGV) signame = "SEGV";
10908 if (code == TS_SIGTERM) signame = "TERM";
10909 if (code == TS_SIGUSR1) signame = "USR1";
10910 if (code == TS_SIGUSR2) signame = "USR2";
10911 /* The SSH-2 protocol does in principle support arbitrary named
10912 * signals, including signame@domain, but we don't support those. */
10914 /* It's a signal. */
10915 if (ssh->version == 2 && ssh->mainchan) {
10916 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
10917 ssh2_pkt_addstring(pktout, signame);
10918 ssh2_pkt_send(ssh, pktout);
10919 logeventf(ssh, "Sent signal SIG%s", signame);
10922 /* Never heard of it. Do nothing */
10927 void *new_sock_channel(void *handle, struct PortForwarding *pf)
10929 Ssh ssh = (Ssh) handle;
10930 struct ssh_channel *c;
10931 c = snew(struct ssh_channel);
10934 ssh2_channel_init(c);
10935 c->halfopen = TRUE;
10936 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
10938 add234(ssh->channels, c);
10942 unsigned ssh_alloc_sharing_channel(Ssh ssh, void *sharing_ctx)
10944 struct ssh_channel *c;
10945 c = snew(struct ssh_channel);
10948 ssh2_channel_init(c);
10949 c->type = CHAN_SHARING;
10950 c->u.sharing.ctx = sharing_ctx;
10951 add234(ssh->channels, c);
10955 void ssh_delete_sharing_channel(Ssh ssh, unsigned localid)
10957 struct ssh_channel *c;
10959 c = find234(ssh->channels, &localid, ssh_channelfind);
10961 ssh_channel_destroy(c);
10964 void ssh_send_packet_from_downstream(Ssh ssh, unsigned id, int type,
10965 const void *data, int datalen,
10966 const char *additional_log_text)
10968 struct Packet *pkt;
10970 pkt = ssh2_pkt_init(type);
10971 pkt->downstream_id = id;
10972 pkt->additional_log_text = additional_log_text;
10973 ssh2_pkt_adddata(pkt, data, datalen);
10974 ssh2_pkt_send(ssh, pkt);
10978 * This is called when stdout/stderr (the entity to which
10979 * from_backend sends data) manages to clear some backlog.
10981 static void ssh_unthrottle(void *handle, int bufsize)
10983 Ssh ssh = (Ssh) handle;
10986 if (ssh->version == 1) {
10987 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
10988 ssh->v1_stdout_throttling = 0;
10989 ssh_throttle_conn(ssh, -1);
10992 if (ssh->mainchan) {
10993 ssh2_set_window(ssh->mainchan,
10994 bufsize < ssh->mainchan->v.v2.locmaxwin ?
10995 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
10996 if (ssh_is_simple(ssh))
10999 buflimit = ssh->mainchan->v.v2.locmaxwin;
11000 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
11001 ssh->mainchan->throttling_conn = 0;
11002 ssh_throttle_conn(ssh, -1);
11008 * Now process any SSH connection data that was stashed in our
11009 * queue while we were frozen.
11011 ssh_process_queued_incoming_data(ssh);
11014 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
11016 struct ssh_channel *c = (struct ssh_channel *)channel;
11018 struct Packet *pktout;
11020 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
11022 if (ssh->version == 1) {
11023 send_packet(ssh, SSH1_MSG_PORT_OPEN,
11024 PKT_INT, c->localid,
11027 /* PKT_STR, <org:orgport>, */
11030 pktout = ssh2_chanopen_init(c, "direct-tcpip");
11032 char *trimmed_host = host_strduptrim(hostname);
11033 ssh2_pkt_addstring(pktout, trimmed_host);
11034 sfree(trimmed_host);
11036 ssh2_pkt_adduint32(pktout, port);
11038 * We make up values for the originator data; partly it's
11039 * too much hassle to keep track, and partly I'm not
11040 * convinced the server should be told details like that
11041 * about my local network configuration.
11042 * The "originator IP address" is syntactically a numeric
11043 * IP address, and some servers (e.g., Tectia) get upset
11044 * if it doesn't match this syntax.
11046 ssh2_pkt_addstring(pktout, "0.0.0.0");
11047 ssh2_pkt_adduint32(pktout, 0);
11048 ssh2_pkt_send(ssh, pktout);
11052 static int ssh_connected(void *handle)
11054 Ssh ssh = (Ssh) handle;
11055 return ssh->s != NULL;
11058 static int ssh_sendok(void *handle)
11060 Ssh ssh = (Ssh) handle;
11061 return ssh->send_ok;
11064 static int ssh_ldisc(void *handle, int option)
11066 Ssh ssh = (Ssh) handle;
11067 if (option == LD_ECHO)
11068 return ssh->echoing;
11069 if (option == LD_EDIT)
11070 return ssh->editing;
11074 static void ssh_provide_ldisc(void *handle, void *ldisc)
11076 Ssh ssh = (Ssh) handle;
11077 ssh->ldisc = ldisc;
11080 static void ssh_provide_logctx(void *handle, void *logctx)
11082 Ssh ssh = (Ssh) handle;
11083 ssh->logctx = logctx;
11086 static int ssh_return_exitcode(void *handle)
11088 Ssh ssh = (Ssh) handle;
11089 if (ssh->s != NULL)
11092 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
11096 * cfg_info for SSH is the currently running version of the
11097 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
11099 static int ssh_cfg_info(void *handle)
11101 Ssh ssh = (Ssh) handle;
11102 return ssh->version;
11106 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
11107 * that fails. This variable is the means by which scp.c can reach
11108 * into the SSH code and find out which one it got.
11110 extern int ssh_fallback_cmd(void *handle)
11112 Ssh ssh = (Ssh) handle;
11113 return ssh->fallback_cmd;
11116 Backend ssh_backend = {
11126 ssh_return_exitcode,
11130 ssh_provide_logctx,