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);
3416 ssh->savedhost = dupstr(loghost);
3417 ssh->savedport = 22; /* default ssh port */
3420 * A colon suffix on savedhost also lets us affect
3423 * (FIXME: do something about IPv6 address literals here.)
3425 colon = strrchr(ssh->savedhost, ':');
3429 ssh->savedport = atoi(colon);
3432 ssh->savedhost = dupstr(host);
3434 port = 22; /* default ssh port */
3435 ssh->savedport = port;
3438 ssh->fn = &fn_table; /* make 'ssh' usable as a Plug */
3441 * Try connection-sharing, in case that means we don't open a
3442 * socket after all. ssh_connection_sharing_init will connect to a
3443 * previously established upstream if it can, and failing that,
3444 * establish a listening socket for _us_ to be the upstream. In
3445 * the latter case it will return NULL just as if it had done
3446 * nothing, because here we only need to care if we're a
3447 * downstream and need to do our connection setup differently.
3449 ssh->connshare = NULL;
3450 ssh->attempting_connshare = TRUE; /* affects socket logging behaviour */
3451 ssh->s = ssh_connection_sharing_init(ssh->savedhost, ssh->savedport,
3452 ssh->conf, ssh, &ssh->connshare);
3453 ssh->attempting_connshare = FALSE;
3454 if (ssh->s != NULL) {
3456 * We are a downstream.
3458 ssh->bare_connection = TRUE;
3459 ssh->do_ssh_init = do_ssh_connection_init;
3460 ssh->fullhostname = NULL;
3461 *realhost = dupstr(host); /* best we can do */
3464 * We're not a downstream, so open a normal socket.
3466 ssh->do_ssh_init = do_ssh_init;
3471 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
3472 logeventf(ssh, "Looking up host \"%s\"%s", host,
3473 (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
3474 (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
3475 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily);
3476 if ((err = sk_addr_error(addr)) != NULL) {
3480 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3482 ssh->s = new_connection(addr, *realhost, port,
3483 0, 1, nodelay, keepalive,
3484 (Plug) ssh, ssh->conf);
3485 if ((err = sk_socket_error(ssh->s)) != NULL) {
3487 notify_remote_exit(ssh->frontend);
3493 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3494 * send the version string too.
3496 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3499 if (sshprot == 3 && !ssh->bare_connection) {
3501 ssh_send_verstring(ssh, "SSH-", NULL);
3505 * loghost, if configured, overrides realhost.
3509 *realhost = dupstr(loghost);
3516 * Throttle or unthrottle the SSH connection.
3518 static void ssh_throttle_conn(Ssh ssh, int adjust)
3520 int old_count = ssh->conn_throttle_count;
3521 ssh->conn_throttle_count += adjust;
3522 assert(ssh->conn_throttle_count >= 0);
3523 if (ssh->conn_throttle_count && !old_count) {
3524 ssh_set_frozen(ssh, 1);
3525 } else if (!ssh->conn_throttle_count && old_count) {
3526 ssh_set_frozen(ssh, 0);
3531 * Throttle or unthrottle _all_ local data streams (for when sends
3532 * on the SSH connection itself back up).
3534 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3537 struct ssh_channel *c;
3539 if (enable == ssh->throttled_all)
3541 ssh->throttled_all = enable;
3542 ssh->overall_bufsize = bufsize;
3545 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3547 case CHAN_MAINSESSION:
3549 * This is treated separately, outside the switch.
3553 x11_override_throttle(c->u.x11.xconn, enable);
3556 /* Agent channels require no buffer management. */
3559 pfd_override_throttle(c->u.pfd.pf, enable);
3565 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3567 Ssh ssh = (Ssh) sshv;
3569 ssh->agent_response = reply;
3570 ssh->agent_response_len = replylen;
3572 if (ssh->version == 1)
3573 do_ssh1_login(ssh, NULL, -1, NULL);
3575 do_ssh2_authconn(ssh, NULL, -1, NULL);
3578 static void ssh_dialog_callback(void *sshv, int ret)
3580 Ssh ssh = (Ssh) sshv;
3582 ssh->user_response = ret;
3584 if (ssh->version == 1)
3585 do_ssh1_login(ssh, NULL, -1, NULL);
3587 do_ssh2_transport(ssh, NULL, -1, NULL);
3590 * This may have unfrozen the SSH connection, so do a
3593 ssh_process_queued_incoming_data(ssh);
3596 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3598 struct ssh_channel *c = (struct ssh_channel *)cv;
3600 void *sentreply = reply;
3602 c->u.a.outstanding_requests--;
3604 /* Fake SSH_AGENT_FAILURE. */
3605 sentreply = "\0\0\0\1\5";
3608 if (ssh->version == 2) {
3609 ssh2_add_channel_data(c, sentreply, replylen);
3612 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3613 PKT_INT, c->remoteid,
3615 PKT_DATA, sentreply, replylen,
3621 * If we've already seen an incoming EOF but haven't sent an
3622 * outgoing one, this may be the moment to send it.
3624 if (c->u.a.outstanding_requests == 0 && (c->closes & CLOSES_RCVD_EOF))
3625 sshfwd_write_eof(c);
3629 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3630 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3631 * => log `wire_reason'.
3633 static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
3634 int code, int clean_exit)
3638 client_reason = wire_reason;
3640 error = dupprintf("Disconnected: %s", client_reason);
3642 error = dupstr("Disconnected");
3644 if (ssh->version == 1) {
3645 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3647 } else if (ssh->version == 2) {
3648 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3649 ssh2_pkt_adduint32(pktout, code);
3650 ssh2_pkt_addstring(pktout, wire_reason);
3651 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3652 ssh2_pkt_send_noqueue(ssh, pktout);
3655 ssh->close_expected = TRUE;
3656 ssh->clean_exit = clean_exit;
3657 ssh_closing((Plug)ssh, error, 0, 0);
3662 * Handle the key exchange and user authentication phases.
3664 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
3665 struct Packet *pktin)
3668 unsigned char cookie[8], *ptr;
3669 struct MD5Context md5c;
3670 struct do_ssh1_login_state {
3673 unsigned char *rsabuf, *keystr1, *keystr2;
3674 unsigned long supported_ciphers_mask, supported_auths_mask;
3675 int tried_publickey, tried_agent;
3676 int tis_auth_refused, ccard_auth_refused;
3677 unsigned char session_id[16];
3679 void *publickey_blob;
3680 int publickey_bloblen;
3681 char *publickey_comment;
3682 int publickey_encrypted;
3683 prompts_t *cur_prompt;
3686 unsigned char request[5], *response, *p;
3696 struct RSAKey servkey, hostkey;
3698 crState(do_ssh1_login_state);
3705 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
3706 bombout(("Public key packet not received"));
3710 logevent("Received public keys");
3712 ptr = ssh_pkt_getdata(pktin, 8);
3714 bombout(("SSH-1 public key packet stopped before random cookie"));
3717 memcpy(cookie, ptr, 8);
3719 if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) ||
3720 !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) {
3721 bombout(("Failed to read SSH-1 public keys from public key packet"));
3726 * Log the host key fingerprint.
3730 logevent("Host key fingerprint is:");
3731 strcpy(logmsg, " ");
3732 s->hostkey.comment = NULL;
3733 rsa_fingerprint(logmsg + strlen(logmsg),
3734 sizeof(logmsg) - strlen(logmsg), &s->hostkey);
3738 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3739 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3740 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
3741 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
3742 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
3744 ssh->v1_local_protoflags =
3745 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3746 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
3749 MD5Update(&md5c, s->keystr2, s->hostkey.bytes);
3750 MD5Update(&md5c, s->keystr1, s->servkey.bytes);
3751 MD5Update(&md5c, cookie, 8);
3752 MD5Final(s->session_id, &md5c);
3754 for (i = 0; i < 32; i++)
3755 ssh->session_key[i] = random_byte();
3758 * Verify that the `bits' and `bytes' parameters match.
3760 if (s->hostkey.bits > s->hostkey.bytes * 8 ||
3761 s->servkey.bits > s->servkey.bytes * 8) {
3762 bombout(("SSH-1 public keys were badly formatted"));
3766 s->len = (s->hostkey.bytes > s->servkey.bytes ?
3767 s->hostkey.bytes : s->servkey.bytes);
3769 s->rsabuf = snewn(s->len, unsigned char);
3772 * Verify the host key.
3776 * First format the key into a string.
3778 int len = rsastr_len(&s->hostkey);
3779 char fingerprint[100];
3780 char *keystr = snewn(len, char);
3781 rsastr_fmt(keystr, &s->hostkey);
3782 rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey);
3784 ssh_set_frozen(ssh, 1);
3785 s->dlgret = verify_ssh_host_key(ssh->frontend,
3786 ssh->savedhost, ssh->savedport,
3787 "rsa", keystr, fingerprint,
3788 ssh_dialog_callback, ssh);
3790 if (s->dlgret < 0) {
3794 bombout(("Unexpected data from server while waiting"
3795 " for user host key response"));
3798 } while (pktin || inlen > 0);
3799 s->dlgret = ssh->user_response;
3801 ssh_set_frozen(ssh, 0);
3803 if (s->dlgret == 0) {
3804 ssh_disconnect(ssh, "User aborted at host key verification",
3810 for (i = 0; i < 32; i++) {
3811 s->rsabuf[i] = ssh->session_key[i];
3813 s->rsabuf[i] ^= s->session_id[i];
3816 if (s->hostkey.bytes > s->servkey.bytes) {
3817 ret = rsaencrypt(s->rsabuf, 32, &s->servkey);
3819 ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey);
3821 ret = rsaencrypt(s->rsabuf, 32, &s->hostkey);
3823 ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey);
3826 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3830 logevent("Encrypted session key");
3833 int cipher_chosen = 0, warn = 0;
3834 char *cipher_string = NULL;
3836 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
3837 int next_cipher = conf_get_int_int(ssh->conf,
3838 CONF_ssh_cipherlist, i);
3839 if (next_cipher == CIPHER_WARN) {
3840 /* If/when we choose a cipher, warn about it */
3842 } else if (next_cipher == CIPHER_AES) {
3843 /* XXX Probably don't need to mention this. */
3844 logevent("AES not supported in SSH-1, skipping");
3846 switch (next_cipher) {
3847 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
3848 cipher_string = "3DES"; break;
3849 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
3850 cipher_string = "Blowfish"; break;
3851 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
3852 cipher_string = "single-DES"; break;
3854 if (s->supported_ciphers_mask & (1 << s->cipher_type))
3858 if (!cipher_chosen) {
3859 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
3860 bombout(("Server violates SSH-1 protocol by not "
3861 "supporting 3DES encryption"));
3863 /* shouldn't happen */
3864 bombout(("No supported ciphers found"));
3868 /* Warn about chosen cipher if necessary. */
3870 ssh_set_frozen(ssh, 1);
3871 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3872 ssh_dialog_callback, ssh);
3873 if (s->dlgret < 0) {
3877 bombout(("Unexpected data from server while waiting"
3878 " for user response"));
3881 } while (pktin || inlen > 0);
3882 s->dlgret = ssh->user_response;
3884 ssh_set_frozen(ssh, 0);
3885 if (s->dlgret == 0) {
3886 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3893 switch (s->cipher_type) {
3894 case SSH_CIPHER_3DES:
3895 logevent("Using 3DES encryption");
3897 case SSH_CIPHER_DES:
3898 logevent("Using single-DES encryption");
3900 case SSH_CIPHER_BLOWFISH:
3901 logevent("Using Blowfish encryption");
3905 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3906 PKT_CHAR, s->cipher_type,
3907 PKT_DATA, cookie, 8,
3908 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3909 PKT_DATA, s->rsabuf, s->len,
3910 PKT_INT, ssh->v1_local_protoflags, PKT_END);
3912 logevent("Trying to enable encryption...");
3916 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3917 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3919 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3920 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
3921 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
3923 ssh->crcda_ctx = crcda_make_context();
3924 logevent("Installing CRC compensation attack detector");
3926 if (s->servkey.modulus) {
3927 sfree(s->servkey.modulus);
3928 s->servkey.modulus = NULL;
3930 if (s->servkey.exponent) {
3931 sfree(s->servkey.exponent);
3932 s->servkey.exponent = NULL;
3934 if (s->hostkey.modulus) {
3935 sfree(s->hostkey.modulus);
3936 s->hostkey.modulus = NULL;
3938 if (s->hostkey.exponent) {
3939 sfree(s->hostkey.exponent);
3940 s->hostkey.exponent = NULL;
3944 if (pktin->type != SSH1_SMSG_SUCCESS) {
3945 bombout(("Encryption not successfully enabled"));
3949 logevent("Successfully started encryption");
3951 fflush(stdout); /* FIXME eh? */
3953 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
3954 int ret; /* need not be kept over crReturn */
3955 s->cur_prompt = new_prompts(ssh->frontend);
3956 s->cur_prompt->to_server = TRUE;
3957 s->cur_prompt->name = dupstr("SSH login name");
3958 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
3959 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3962 crWaitUntil(!pktin);
3963 ret = get_userpass_input(s->cur_prompt, in, inlen);
3968 * Failed to get a username. Terminate.
3970 free_prompts(s->cur_prompt);
3971 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
3974 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
3975 free_prompts(s->cur_prompt);
3978 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
3980 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
3982 if (flags & FLAG_INTERACTIVE &&
3983 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3984 c_write_str(ssh, userlog);
3985 c_write_str(ssh, "\r\n");
3993 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
3994 /* We must not attempt PK auth. Pretend we've already tried it. */
3995 s->tried_publickey = s->tried_agent = 1;
3997 s->tried_publickey = s->tried_agent = 0;
3999 s->tis_auth_refused = s->ccard_auth_refused = 0;
4001 * Load the public half of any configured keyfile for later use.
4003 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4004 if (!filename_is_null(s->keyfile)) {
4006 logeventf(ssh, "Reading private key file \"%.150s\"",
4007 filename_to_str(s->keyfile));
4008 keytype = key_type(s->keyfile);
4009 if (keytype == SSH_KEYTYPE_SSH1) {
4011 if (rsakey_pubblob(s->keyfile,
4012 &s->publickey_blob, &s->publickey_bloblen,
4013 &s->publickey_comment, &error)) {
4014 s->publickey_encrypted = rsakey_encrypted(s->keyfile,
4018 logeventf(ssh, "Unable to load private key (%s)", error);
4019 msgbuf = dupprintf("Unable to load private key file "
4020 "\"%.150s\" (%s)\r\n",
4021 filename_to_str(s->keyfile),
4023 c_write_str(ssh, msgbuf);
4025 s->publickey_blob = NULL;
4029 logeventf(ssh, "Unable to use this key file (%s)",
4030 key_type_to_str(keytype));
4031 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4033 filename_to_str(s->keyfile),
4034 key_type_to_str(keytype));
4035 c_write_str(ssh, msgbuf);
4037 s->publickey_blob = NULL;
4040 s->publickey_blob = NULL;
4042 while (pktin->type == SSH1_SMSG_FAILURE) {
4043 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
4045 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
4047 * Attempt RSA authentication using Pageant.
4053 logevent("Pageant is running. Requesting keys.");
4055 /* Request the keys held by the agent. */
4056 PUT_32BIT(s->request, 1);
4057 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
4058 if (!agent_query(s->request, 5, &r, &s->responselen,
4059 ssh_agent_callback, ssh)) {
4063 bombout(("Unexpected data from server while waiting"
4064 " for agent response"));
4067 } while (pktin || inlen > 0);
4068 r = ssh->agent_response;
4069 s->responselen = ssh->agent_response_len;
4071 s->response = (unsigned char *) r;
4072 if (s->response && s->responselen >= 5 &&
4073 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
4074 s->p = s->response + 5;
4075 s->nkeys = toint(GET_32BIT(s->p));
4077 logeventf(ssh, "Pageant reported negative key count %d",
4082 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
4083 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4084 unsigned char *pkblob = s->p;
4088 do { /* do while (0) to make breaking easy */
4089 n = ssh1_read_bignum
4090 (s->p, toint(s->responselen-(s->p-s->response)),
4095 n = ssh1_read_bignum
4096 (s->p, toint(s->responselen-(s->p-s->response)),
4101 if (s->responselen - (s->p-s->response) < 4)
4103 s->commentlen = toint(GET_32BIT(s->p));
4105 if (s->commentlen < 0 ||
4106 toint(s->responselen - (s->p-s->response)) <
4109 s->commentp = (char *)s->p;
4110 s->p += s->commentlen;
4114 logevent("Pageant key list packet was truncated");
4118 if (s->publickey_blob) {
4119 if (!memcmp(pkblob, s->publickey_blob,
4120 s->publickey_bloblen)) {
4121 logeventf(ssh, "Pageant key #%d matches "
4122 "configured key file", s->keyi);
4123 s->tried_publickey = 1;
4125 /* Skip non-configured key */
4128 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
4129 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4130 PKT_BIGNUM, s->key.modulus, PKT_END);
4132 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4133 logevent("Key refused");
4136 logevent("Received RSA challenge");
4137 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4138 bombout(("Server's RSA challenge was badly formatted"));
4143 char *agentreq, *q, *ret;
4146 len = 1 + 4; /* message type, bit count */
4147 len += ssh1_bignum_length(s->key.exponent);
4148 len += ssh1_bignum_length(s->key.modulus);
4149 len += ssh1_bignum_length(s->challenge);
4150 len += 16; /* session id */
4151 len += 4; /* response format */
4152 agentreq = snewn(4 + len, char);
4153 PUT_32BIT(agentreq, len);
4155 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
4156 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
4158 q += ssh1_write_bignum(q, s->key.exponent);
4159 q += ssh1_write_bignum(q, s->key.modulus);
4160 q += ssh1_write_bignum(q, s->challenge);
4161 memcpy(q, s->session_id, 16);
4163 PUT_32BIT(q, 1); /* response format */
4164 if (!agent_query(agentreq, len + 4, &vret, &retlen,
4165 ssh_agent_callback, ssh)) {
4170 bombout(("Unexpected data from server"
4171 " while waiting for agent"
4175 } while (pktin || inlen > 0);
4176 vret = ssh->agent_response;
4177 retlen = ssh->agent_response_len;
4182 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
4183 logevent("Sending Pageant's response");
4184 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4185 PKT_DATA, ret + 5, 16,
4189 if (pktin->type == SSH1_SMSG_SUCCESS) {
4191 ("Pageant's response accepted");
4192 if (flags & FLAG_VERBOSE) {
4193 c_write_str(ssh, "Authenticated using"
4195 c_write(ssh, s->commentp,
4197 c_write_str(ssh, "\" from agent\r\n");
4202 ("Pageant's response not accepted");
4205 ("Pageant failed to answer challenge");
4209 logevent("No reply received from Pageant");
4212 freebn(s->key.exponent);
4213 freebn(s->key.modulus);
4214 freebn(s->challenge);
4219 if (s->publickey_blob && !s->tried_publickey)
4220 logevent("Configured key file not in Pageant");
4222 logevent("Failed to get reply from Pageant");
4227 if (s->publickey_blob && !s->tried_publickey) {
4229 * Try public key authentication with the specified
4232 int got_passphrase; /* need not be kept over crReturn */
4233 if (flags & FLAG_VERBOSE)
4234 c_write_str(ssh, "Trying public key authentication.\r\n");
4235 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4236 logeventf(ssh, "Trying public key \"%s\"",
4237 filename_to_str(s->keyfile));
4238 s->tried_publickey = 1;
4239 got_passphrase = FALSE;
4240 while (!got_passphrase) {
4242 * Get a passphrase, if necessary.
4244 char *passphrase = NULL; /* only written after crReturn */
4246 if (!s->publickey_encrypted) {
4247 if (flags & FLAG_VERBOSE)
4248 c_write_str(ssh, "No passphrase required.\r\n");
4251 int ret; /* need not be kept over crReturn */
4252 s->cur_prompt = new_prompts(ssh->frontend);
4253 s->cur_prompt->to_server = FALSE;
4254 s->cur_prompt->name = dupstr("SSH key passphrase");
4255 add_prompt(s->cur_prompt,
4256 dupprintf("Passphrase for key \"%.100s\": ",
4257 s->publickey_comment), FALSE);
4258 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4261 crWaitUntil(!pktin);
4262 ret = get_userpass_input(s->cur_prompt, in, inlen);
4266 /* Failed to get a passphrase. Terminate. */
4267 free_prompts(s->cur_prompt);
4268 ssh_disconnect(ssh, NULL, "Unable to authenticate",
4272 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
4273 free_prompts(s->cur_prompt);
4276 * Try decrypting key with passphrase.
4278 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4279 ret = loadrsakey(s->keyfile, &s->key, passphrase,
4282 smemclr(passphrase, strlen(passphrase));
4286 /* Correct passphrase. */
4287 got_passphrase = TRUE;
4288 } else if (ret == 0) {
4289 c_write_str(ssh, "Couldn't load private key from ");
4290 c_write_str(ssh, filename_to_str(s->keyfile));
4291 c_write_str(ssh, " (");
4292 c_write_str(ssh, error);
4293 c_write_str(ssh, ").\r\n");
4294 got_passphrase = FALSE;
4295 break; /* go and try something else */
4296 } else if (ret == -1) {
4297 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
4298 got_passphrase = FALSE;
4301 assert(0 && "unexpected return from loadrsakey()");
4302 got_passphrase = FALSE; /* placate optimisers */
4306 if (got_passphrase) {
4309 * Send a public key attempt.
4311 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4312 PKT_BIGNUM, s->key.modulus, PKT_END);
4315 if (pktin->type == SSH1_SMSG_FAILURE) {
4316 c_write_str(ssh, "Server refused our public key.\r\n");
4317 continue; /* go and try something else */
4319 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4320 bombout(("Bizarre response to offer of public key"));
4326 unsigned char buffer[32];
4327 Bignum challenge, response;
4329 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4330 bombout(("Server's RSA challenge was badly formatted"));
4333 response = rsadecrypt(challenge, &s->key);
4334 freebn(s->key.private_exponent);/* burn the evidence */
4336 for (i = 0; i < 32; i++) {
4337 buffer[i] = bignum_byte(response, 31 - i);
4341 MD5Update(&md5c, buffer, 32);
4342 MD5Update(&md5c, s->session_id, 16);
4343 MD5Final(buffer, &md5c);
4345 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4346 PKT_DATA, buffer, 16, PKT_END);
4353 if (pktin->type == SSH1_SMSG_FAILURE) {
4354 if (flags & FLAG_VERBOSE)
4355 c_write_str(ssh, "Failed to authenticate with"
4356 " our public key.\r\n");
4357 continue; /* go and try something else */
4358 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4359 bombout(("Bizarre response to RSA authentication response"));
4363 break; /* we're through! */
4369 * Otherwise, try various forms of password-like authentication.
4371 s->cur_prompt = new_prompts(ssh->frontend);
4373 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4374 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
4375 !s->tis_auth_refused) {
4376 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
4377 logevent("Requested TIS authentication");
4378 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
4380 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
4381 logevent("TIS authentication declined");
4382 if (flags & FLAG_INTERACTIVE)
4383 c_write_str(ssh, "TIS authentication refused.\r\n");
4384 s->tis_auth_refused = 1;
4389 char *instr_suf, *prompt;
4391 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4393 bombout(("TIS challenge packet was badly formed"));
4396 logevent("Received TIS challenge");
4397 s->cur_prompt->to_server = TRUE;
4398 s->cur_prompt->name = dupstr("SSH TIS authentication");
4399 /* Prompt heuristic comes from OpenSSH */
4400 if (memchr(challenge, '\n', challengelen)) {
4401 instr_suf = dupstr("");
4402 prompt = dupprintf("%.*s", challengelen, challenge);
4404 instr_suf = dupprintf("%.*s", challengelen, challenge);
4405 prompt = dupstr("Response: ");
4407 s->cur_prompt->instruction =
4408 dupprintf("Using TIS authentication.%s%s",
4409 (*instr_suf) ? "\n" : "",
4411 s->cur_prompt->instr_reqd = TRUE;
4412 add_prompt(s->cur_prompt, prompt, FALSE);
4416 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4417 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
4418 !s->ccard_auth_refused) {
4419 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
4420 logevent("Requested CryptoCard authentication");
4421 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
4423 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
4424 logevent("CryptoCard authentication declined");
4425 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4426 s->ccard_auth_refused = 1;
4431 char *instr_suf, *prompt;
4433 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4435 bombout(("CryptoCard challenge packet was badly formed"));
4438 logevent("Received CryptoCard challenge");
4439 s->cur_prompt->to_server = TRUE;
4440 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4441 s->cur_prompt->name_reqd = FALSE;
4442 /* Prompt heuristic comes from OpenSSH */
4443 if (memchr(challenge, '\n', challengelen)) {
4444 instr_suf = dupstr("");
4445 prompt = dupprintf("%.*s", challengelen, challenge);
4447 instr_suf = dupprintf("%.*s", challengelen, challenge);
4448 prompt = dupstr("Response: ");
4450 s->cur_prompt->instruction =
4451 dupprintf("Using CryptoCard authentication.%s%s",
4452 (*instr_suf) ? "\n" : "",
4454 s->cur_prompt->instr_reqd = TRUE;
4455 add_prompt(s->cur_prompt, prompt, FALSE);
4459 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4460 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4461 bombout(("No supported authentication methods available"));
4464 s->cur_prompt->to_server = TRUE;
4465 s->cur_prompt->name = dupstr("SSH password");
4466 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4467 ssh->username, ssh->savedhost),
4472 * Show password prompt, having first obtained it via a TIS
4473 * or CryptoCard exchange if we're doing TIS or CryptoCard
4477 int ret; /* need not be kept over crReturn */
4478 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4481 crWaitUntil(!pktin);
4482 ret = get_userpass_input(s->cur_prompt, in, inlen);
4487 * Failed to get a password (for example
4488 * because one was supplied on the command line
4489 * which has already failed to work). Terminate.
4491 free_prompts(s->cur_prompt);
4492 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4497 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4499 * Defence against traffic analysis: we send a
4500 * whole bunch of packets containing strings of
4501 * different lengths. One of these strings is the
4502 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4503 * The others are all random data in
4504 * SSH1_MSG_IGNORE packets. This way a passive
4505 * listener can't tell which is the password, and
4506 * hence can't deduce the password length.
4508 * Anybody with a password length greater than 16
4509 * bytes is going to have enough entropy in their
4510 * password that a listener won't find it _that_
4511 * much help to know how long it is. So what we'll
4514 * - if password length < 16, we send 15 packets
4515 * containing string lengths 1 through 15
4517 * - otherwise, we let N be the nearest multiple
4518 * of 8 below the password length, and send 8
4519 * packets containing string lengths N through
4520 * N+7. This won't obscure the order of
4521 * magnitude of the password length, but it will
4522 * introduce a bit of extra uncertainty.
4524 * A few servers can't deal with SSH1_MSG_IGNORE, at
4525 * least in this context. For these servers, we need
4526 * an alternative defence. We make use of the fact
4527 * that the password is interpreted as a C string:
4528 * so we can append a NUL, then some random data.
4530 * A few servers can deal with neither SSH1_MSG_IGNORE
4531 * here _nor_ a padded password string.
4532 * For these servers we are left with no defences
4533 * against password length sniffing.
4535 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4536 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4538 * The server can deal with SSH1_MSG_IGNORE, so
4539 * we can use the primary defence.
4541 int bottom, top, pwlen, i;
4544 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4546 bottom = 0; /* zero length passwords are OK! :-) */
4549 bottom = pwlen & ~7;
4553 assert(pwlen >= bottom && pwlen <= top);
4555 randomstr = snewn(top + 1, char);
4557 for (i = bottom; i <= top; i++) {
4559 defer_packet(ssh, s->pwpkt_type,
4560 PKT_STR,s->cur_prompt->prompts[0]->result,
4563 for (j = 0; j < i; j++) {
4565 randomstr[j] = random_byte();
4566 } while (randomstr[j] == '\0');
4568 randomstr[i] = '\0';
4569 defer_packet(ssh, SSH1_MSG_IGNORE,
4570 PKT_STR, randomstr, PKT_END);
4573 logevent("Sending password with camouflage packets");
4574 ssh_pkt_defersend(ssh);
4577 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4579 * The server can't deal with SSH1_MSG_IGNORE
4580 * but can deal with padded passwords, so we
4581 * can use the secondary defence.
4587 len = strlen(s->cur_prompt->prompts[0]->result);
4588 if (len < sizeof(string)) {
4590 strcpy(string, s->cur_prompt->prompts[0]->result);
4591 len++; /* cover the zero byte */
4592 while (len < sizeof(string)) {
4593 string[len++] = (char) random_byte();
4596 ss = s->cur_prompt->prompts[0]->result;
4598 logevent("Sending length-padded password");
4599 send_packet(ssh, s->pwpkt_type,
4600 PKT_INT, len, PKT_DATA, ss, len,
4604 * The server is believed unable to cope with
4605 * any of our password camouflage methods.
4608 len = strlen(s->cur_prompt->prompts[0]->result);
4609 logevent("Sending unpadded password");
4610 send_packet(ssh, s->pwpkt_type,
4612 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4616 send_packet(ssh, s->pwpkt_type,
4617 PKT_STR, s->cur_prompt->prompts[0]->result,
4620 logevent("Sent password");
4621 free_prompts(s->cur_prompt);
4623 if (pktin->type == SSH1_SMSG_FAILURE) {
4624 if (flags & FLAG_VERBOSE)
4625 c_write_str(ssh, "Access denied\r\n");
4626 logevent("Authentication refused");
4627 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4628 bombout(("Strange packet received, type %d", pktin->type));
4634 if (s->publickey_blob) {
4635 sfree(s->publickey_blob);
4636 sfree(s->publickey_comment);
4639 logevent("Authentication successful");
4644 static void ssh_channel_try_eof(struct ssh_channel *c)
4647 assert(c->pending_eof); /* precondition for calling us */
4649 return; /* can't close: not even opened yet */
4650 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4651 return; /* can't send EOF: pending outgoing data */
4653 c->pending_eof = FALSE; /* we're about to send it */
4654 if (ssh->version == 1) {
4655 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4657 c->closes |= CLOSES_SENT_EOF;
4659 struct Packet *pktout;
4660 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4661 ssh2_pkt_adduint32(pktout, c->remoteid);
4662 ssh2_pkt_send(ssh, pktout);
4663 c->closes |= CLOSES_SENT_EOF;
4664 ssh2_channel_check_close(c);
4668 Conf *sshfwd_get_conf(struct ssh_channel *c)
4674 void sshfwd_write_eof(struct ssh_channel *c)
4678 if (ssh->state == SSH_STATE_CLOSED)
4681 if (c->closes & CLOSES_SENT_EOF)
4684 c->pending_eof = TRUE;
4685 ssh_channel_try_eof(c);
4688 void sshfwd_unclean_close(struct ssh_channel *c, const char *err)
4692 if (ssh->state == SSH_STATE_CLOSED)
4697 x11_close(c->u.x11.xconn);
4698 logeventf(ssh, "Forwarded X11 connection terminated due to local "
4702 case CHAN_SOCKDATA_DORMANT:
4703 pfd_close(c->u.pfd.pf);
4704 logeventf(ssh, "Forwarded port closed due to local error: %s", err);
4707 c->type = CHAN_ZOMBIE;
4708 c->pending_eof = FALSE; /* this will confuse a zombie channel */
4710 ssh2_channel_check_close(c);
4713 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
4717 if (ssh->state == SSH_STATE_CLOSED)
4720 if (ssh->version == 1) {
4721 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
4722 PKT_INT, c->remoteid,
4723 PKT_INT, len, PKT_DATA, buf, len,
4726 * In SSH-1 we can return 0 here - implying that forwarded
4727 * connections are never individually throttled - because
4728 * the only circumstance that can cause throttling will be
4729 * the whole SSH connection backing up, in which case
4730 * _everything_ will be throttled as a whole.
4734 ssh2_add_channel_data(c, buf, len);
4735 return ssh2_try_send(c);
4739 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4744 if (ssh->state == SSH_STATE_CLOSED)
4747 if (ssh->version == 1) {
4748 buflimit = SSH1_BUFFER_LIMIT;
4750 buflimit = c->v.v2.locmaxwin;
4751 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
4753 if (c->throttling_conn && bufsize <= buflimit) {
4754 c->throttling_conn = 0;
4755 ssh_throttle_conn(ssh, -1);
4759 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
4761 struct queued_handler *qh = ssh->qhead;
4765 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
4768 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
4769 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
4772 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
4773 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
4777 ssh->qhead = qh->next;
4779 if (ssh->qhead->msg1 > 0) {
4780 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4781 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
4783 if (ssh->qhead->msg2 > 0) {
4784 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4785 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
4788 ssh->qhead = ssh->qtail = NULL;
4791 qh->handler(ssh, pktin, qh->ctx);
4796 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
4797 chandler_fn_t handler, void *ctx)
4799 struct queued_handler *qh;
4801 qh = snew(struct queued_handler);
4804 qh->handler = handler;
4808 if (ssh->qtail == NULL) {
4812 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4813 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
4816 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4817 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
4820 ssh->qtail->next = qh;
4825 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
4827 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
4829 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
4830 SSH2_MSG_REQUEST_SUCCESS)) {
4831 logeventf(ssh, "Remote port forwarding from %s enabled",
4834 logeventf(ssh, "Remote port forwarding from %s refused",
4837 rpf = del234(ssh->rportfwds, pf);
4839 pf->pfrec->remote = NULL;
4844 int ssh_alloc_sharing_rportfwd(Ssh ssh, const char *shost, int sport,
4847 struct ssh_rportfwd *pf = snew(struct ssh_rportfwd);
4850 pf->share_ctx = share_ctx;
4851 pf->shost = dupstr(shost);
4853 pf->sportdesc = NULL;
4854 if (!ssh->rportfwds) {
4855 assert(ssh->version == 2);
4856 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4858 if (add234(ssh->rportfwds, pf) != pf) {
4866 static void ssh_sharing_global_request_response(Ssh ssh, struct Packet *pktin,
4869 share_got_pkt_from_server(ctx, pktin->type,
4870 pktin->body, pktin->length);
4873 void ssh_sharing_queue_global_request(Ssh ssh, void *share_ctx)
4875 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, SSH2_MSG_REQUEST_FAILURE,
4876 ssh_sharing_global_request_response, share_ctx);
4879 static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
4881 struct ssh_portfwd *epf;
4885 if (!ssh->portfwds) {
4886 ssh->portfwds = newtree234(ssh_portcmp);
4889 * Go through the existing port forwardings and tag them
4890 * with status==DESTROY. Any that we want to keep will be
4891 * re-enabled (status==KEEP) as we go through the
4892 * configuration and find out which bits are the same as
4895 struct ssh_portfwd *epf;
4897 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4898 epf->status = DESTROY;
4901 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
4903 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
4904 char *kp, *kp2, *vp, *vp2;
4905 char address_family, type;
4906 int sport,dport,sserv,dserv;
4907 char *sports, *dports, *saddr, *host;
4911 address_family = 'A';
4913 if (*kp == 'A' || *kp == '4' || *kp == '6')
4914 address_family = *kp++;
4915 if (*kp == 'L' || *kp == 'R')
4918 if ((kp2 = strchr(kp, ':')) != NULL) {
4920 * There's a colon in the middle of the source port
4921 * string, which means that the part before it is
4922 * actually a source address.
4924 saddr = dupprintf("%.*s", (int)(kp2 - kp), kp);
4930 sport = atoi(sports);
4934 sport = net_service_lookup(sports);
4936 logeventf(ssh, "Service lookup failed for source"
4937 " port \"%s\"", sports);
4941 if (type == 'L' && !strcmp(val, "D")) {
4942 /* dynamic forwarding */
4949 /* ordinary forwarding */
4951 vp2 = vp + strcspn(vp, ":");
4952 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
4956 dport = atoi(dports);
4960 dport = net_service_lookup(dports);
4962 logeventf(ssh, "Service lookup failed for destination"
4963 " port \"%s\"", dports);
4968 if (sport && dport) {
4969 /* Set up a description of the source port. */
4970 struct ssh_portfwd *pfrec, *epfrec;
4972 pfrec = snew(struct ssh_portfwd);
4974 pfrec->saddr = saddr;
4975 pfrec->sserv = sserv ? dupstr(sports) : NULL;
4976 pfrec->sport = sport;
4977 pfrec->daddr = host;
4978 pfrec->dserv = dserv ? dupstr(dports) : NULL;
4979 pfrec->dport = dport;
4980 pfrec->local = NULL;
4981 pfrec->remote = NULL;
4982 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
4983 address_family == '6' ? ADDRTYPE_IPV6 :
4986 epfrec = add234(ssh->portfwds, pfrec);
4987 if (epfrec != pfrec) {
4988 if (epfrec->status == DESTROY) {
4990 * We already have a port forwarding up and running
4991 * with precisely these parameters. Hence, no need
4992 * to do anything; simply re-tag the existing one
4995 epfrec->status = KEEP;
4998 * Anything else indicates that there was a duplicate
4999 * in our input, which we'll silently ignore.
5001 free_portfwd(pfrec);
5003 pfrec->status = CREATE;
5012 * Now go through and destroy any port forwardings which were
5015 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5016 if (epf->status == DESTROY) {
5019 message = dupprintf("%s port forwarding from %s%s%d",
5020 epf->type == 'L' ? "local" :
5021 epf->type == 'R' ? "remote" : "dynamic",
5022 epf->saddr ? epf->saddr : "",
5023 epf->saddr ? ":" : "",
5026 if (epf->type != 'D') {
5027 char *msg2 = dupprintf("%s to %s:%d", message,
5028 epf->daddr, epf->dport);
5033 logeventf(ssh, "Cancelling %s", message);
5036 /* epf->remote or epf->local may be NULL if setting up a
5037 * forwarding failed. */
5039 struct ssh_rportfwd *rpf = epf->remote;
5040 struct Packet *pktout;
5043 * Cancel the port forwarding at the server
5046 if (ssh->version == 1) {
5048 * We cannot cancel listening ports on the
5049 * server side in SSH-1! There's no message
5050 * to support it. Instead, we simply remove
5051 * the rportfwd record from the local end
5052 * so that any connections the server tries
5053 * to make on it are rejected.
5056 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5057 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
5058 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
5060 ssh2_pkt_addstring(pktout, epf->saddr);
5061 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5062 /* XXX: rport_acceptall may not represent
5063 * what was used to open the original connection,
5064 * since it's reconfigurable. */
5065 ssh2_pkt_addstring(pktout, "");
5067 ssh2_pkt_addstring(pktout, "localhost");
5069 ssh2_pkt_adduint32(pktout, epf->sport);
5070 ssh2_pkt_send(ssh, pktout);
5073 del234(ssh->rportfwds, rpf);
5075 } else if (epf->local) {
5076 pfl_terminate(epf->local);
5079 delpos234(ssh->portfwds, i);
5081 i--; /* so we don't skip one in the list */
5085 * And finally, set up any new port forwardings (status==CREATE).
5087 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5088 if (epf->status == CREATE) {
5089 char *sportdesc, *dportdesc;
5090 sportdesc = dupprintf("%s%s%s%s%d%s",
5091 epf->saddr ? epf->saddr : "",
5092 epf->saddr ? ":" : "",
5093 epf->sserv ? epf->sserv : "",
5094 epf->sserv ? "(" : "",
5096 epf->sserv ? ")" : "");
5097 if (epf->type == 'D') {
5100 dportdesc = dupprintf("%s:%s%s%d%s",
5102 epf->dserv ? epf->dserv : "",
5103 epf->dserv ? "(" : "",
5105 epf->dserv ? ")" : "");
5108 if (epf->type == 'L') {
5109 char *err = pfl_listen(epf->daddr, epf->dport,
5110 epf->saddr, epf->sport,
5111 ssh, conf, &epf->local,
5112 epf->addressfamily);
5114 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
5115 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5116 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5117 sportdesc, dportdesc,
5118 err ? " failed: " : "", err ? err : "");
5121 } else if (epf->type == 'D') {
5122 char *err = pfl_listen(NULL, -1, epf->saddr, epf->sport,
5123 ssh, conf, &epf->local,
5124 epf->addressfamily);
5126 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
5127 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5128 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5130 err ? " failed: " : "", err ? err : "");
5135 struct ssh_rportfwd *pf;
5138 * Ensure the remote port forwardings tree exists.
5140 if (!ssh->rportfwds) {
5141 if (ssh->version == 1)
5142 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
5144 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5147 pf = snew(struct ssh_rportfwd);
5148 pf->share_ctx = NULL;
5149 pf->dhost = dupstr(epf->daddr);
5150 pf->dport = epf->dport;
5152 pf->shost = dupstr(epf->saddr);
5153 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5154 pf->shost = dupstr("");
5156 pf->shost = dupstr("localhost");
5158 pf->sport = epf->sport;
5159 if (add234(ssh->rportfwds, pf) != pf) {
5160 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
5161 epf->daddr, epf->dport);
5164 logeventf(ssh, "Requesting remote port %s"
5165 " forward to %s", sportdesc, dportdesc);
5167 pf->sportdesc = sportdesc;
5172 if (ssh->version == 1) {
5173 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
5174 PKT_INT, epf->sport,
5175 PKT_STR, epf->daddr,
5176 PKT_INT, epf->dport,
5178 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
5180 ssh_rportfwd_succfail, pf);
5182 struct Packet *pktout;
5183 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5184 ssh2_pkt_addstring(pktout, "tcpip-forward");
5185 ssh2_pkt_addbool(pktout, 1);/* want reply */
5186 ssh2_pkt_addstring(pktout, pf->shost);
5187 ssh2_pkt_adduint32(pktout, pf->sport);
5188 ssh2_pkt_send(ssh, pktout);
5190 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
5191 SSH2_MSG_REQUEST_FAILURE,
5192 ssh_rportfwd_succfail, pf);
5201 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
5204 int stringlen, bufsize;
5206 ssh_pkt_getstring(pktin, &string, &stringlen);
5207 if (string == NULL) {
5208 bombout(("Incoming terminal data packet was badly formed"));
5212 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
5214 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
5215 ssh->v1_stdout_throttling = 1;
5216 ssh_throttle_conn(ssh, +1);
5220 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
5222 /* Remote side is trying to open a channel to talk to our
5223 * X-Server. Give them back a local channel number. */
5224 struct ssh_channel *c;
5225 int remoteid = ssh_pkt_getuint32(pktin);
5227 logevent("Received X11 connect request");
5228 /* Refuse if X11 forwarding is disabled. */
5229 if (!ssh->X11_fwd_enabled) {
5230 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5231 PKT_INT, remoteid, PKT_END);
5232 logevent("Rejected X11 connect request");
5234 c = snew(struct ssh_channel);
5237 c->u.x11.xconn = x11_init(ssh->x11authtree, c, NULL, -1);
5238 c->remoteid = remoteid;
5239 c->halfopen = FALSE;
5240 c->localid = alloc_channel_id(ssh);
5242 c->pending_eof = FALSE;
5243 c->throttling_conn = 0;
5244 c->type = CHAN_X11; /* identify channel type */
5245 add234(ssh->channels, c);
5246 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5247 PKT_INT, c->remoteid, PKT_INT,
5248 c->localid, PKT_END);
5249 logevent("Opened X11 forward channel");
5253 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
5255 /* Remote side is trying to open a channel to talk to our
5256 * agent. Give them back a local channel number. */
5257 struct ssh_channel *c;
5258 int remoteid = ssh_pkt_getuint32(pktin);
5260 /* Refuse if agent forwarding is disabled. */
5261 if (!ssh->agentfwd_enabled) {
5262 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5263 PKT_INT, remoteid, PKT_END);
5265 c = snew(struct ssh_channel);
5267 c->remoteid = remoteid;
5268 c->halfopen = FALSE;
5269 c->localid = alloc_channel_id(ssh);
5271 c->pending_eof = FALSE;
5272 c->throttling_conn = 0;
5273 c->type = CHAN_AGENT; /* identify channel type */
5274 c->u.a.lensofar = 0;
5275 c->u.a.message = NULL;
5276 c->u.a.outstanding_requests = 0;
5277 add234(ssh->channels, c);
5278 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5279 PKT_INT, c->remoteid, PKT_INT, c->localid,
5284 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
5286 /* Remote side is trying to open a channel to talk to a
5287 * forwarded port. Give them back a local channel number. */
5288 struct ssh_rportfwd pf, *pfp;
5294 remoteid = ssh_pkt_getuint32(pktin);
5295 ssh_pkt_getstring(pktin, &host, &hostsize);
5296 port = ssh_pkt_getuint32(pktin);
5298 pf.dhost = dupprintf("%.*s", hostsize, host);
5300 pfp = find234(ssh->rportfwds, &pf, NULL);
5303 logeventf(ssh, "Rejected remote port open request for %s:%d",
5305 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5306 PKT_INT, remoteid, PKT_END);
5308 struct ssh_channel *c = snew(struct ssh_channel);
5311 logeventf(ssh, "Received remote port open request for %s:%d",
5313 err = pfd_connect(&c->u.pfd.pf, pf.dhost, port,
5314 c, ssh->conf, pfp->pfrec->addressfamily);
5316 logeventf(ssh, "Port open failed: %s", err);
5319 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5320 PKT_INT, remoteid, PKT_END);
5322 c->remoteid = remoteid;
5323 c->halfopen = FALSE;
5324 c->localid = alloc_channel_id(ssh);
5326 c->pending_eof = FALSE;
5327 c->throttling_conn = 0;
5328 c->type = CHAN_SOCKDATA; /* identify channel type */
5329 add234(ssh->channels, c);
5330 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5331 PKT_INT, c->remoteid, PKT_INT,
5332 c->localid, PKT_END);
5333 logevent("Forwarded port opened successfully");
5340 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5342 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5343 unsigned int localid = ssh_pkt_getuint32(pktin);
5344 struct ssh_channel *c;
5346 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5347 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5348 c->remoteid = localid;
5349 c->halfopen = FALSE;
5350 c->type = CHAN_SOCKDATA;
5351 c->throttling_conn = 0;
5352 pfd_confirm(c->u.pfd.pf);
5355 if (c && c->pending_eof) {
5357 * We have a pending close on this channel,
5358 * which we decided on before the server acked
5359 * the channel open. So now we know the
5360 * remoteid, we can close it again.
5362 ssh_channel_try_eof(c);
5366 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5368 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5369 struct ssh_channel *c;
5371 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5372 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5373 logevent("Forwarded connection refused by server");
5374 pfd_close(c->u.pfd.pf);
5375 del234(ssh->channels, c);
5380 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
5382 /* Remote side closes a channel. */
5383 unsigned i = ssh_pkt_getuint32(pktin);
5384 struct ssh_channel *c;
5385 c = find234(ssh->channels, &i, ssh_channelfind);
5386 if (c && !c->halfopen) {
5388 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
5389 !(c->closes & CLOSES_RCVD_EOF)) {
5391 * Received CHANNEL_CLOSE, which we translate into
5394 int send_close = FALSE;
5396 c->closes |= CLOSES_RCVD_EOF;
5401 x11_send_eof(c->u.x11.xconn);
5407 pfd_send_eof(c->u.pfd.pf);
5416 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
5417 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
5419 c->closes |= CLOSES_SENT_EOF;
5423 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
5424 !(c->closes & CLOSES_RCVD_CLOSE)) {
5426 if (!(c->closes & CLOSES_SENT_EOF)) {
5427 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
5428 " for which we never sent CHANNEL_CLOSE\n", i));
5431 c->closes |= CLOSES_RCVD_CLOSE;
5434 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
5435 !(c->closes & CLOSES_SENT_CLOSE)) {
5436 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
5437 PKT_INT, c->remoteid, PKT_END);
5438 c->closes |= CLOSES_SENT_CLOSE;
5441 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5442 ssh_channel_destroy(c);
5444 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5445 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
5446 "_CONFIRMATION", c ? "half-open" : "nonexistent",
5451 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5453 /* Data sent down one of our channels. */
5454 int i = ssh_pkt_getuint32(pktin);
5457 struct ssh_channel *c;
5459 ssh_pkt_getstring(pktin, &p, &len);
5461 c = find234(ssh->channels, &i, ssh_channelfind);
5466 bufsize = x11_send(c->u.x11.xconn, p, len);
5469 bufsize = pfd_send(c->u.pfd.pf, p, len);
5472 /* Data for an agent message. Buffer it. */
5474 if (c->u.a.lensofar < 4) {
5475 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
5476 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
5480 c->u.a.lensofar += l;
5482 if (c->u.a.lensofar == 4) {
5484 4 + GET_32BIT(c->u.a.msglen);
5485 c->u.a.message = snewn(c->u.a.totallen,
5487 memcpy(c->u.a.message, c->u.a.msglen, 4);
5489 if (c->u.a.lensofar >= 4 && len > 0) {
5491 min(c->u.a.totallen - c->u.a.lensofar,
5493 memcpy(c->u.a.message + c->u.a.lensofar, p,
5497 c->u.a.lensofar += l;
5499 if (c->u.a.lensofar == c->u.a.totallen) {
5502 c->u.a.outstanding_requests++;
5503 if (agent_query(c->u.a.message,
5506 ssh_agentf_callback, c))
5507 ssh_agentf_callback(c, reply, replylen);
5508 sfree(c->u.a.message);
5509 c->u.a.lensofar = 0;
5512 bufsize = 0; /* agent channels never back up */
5515 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5516 c->throttling_conn = 1;
5517 ssh_throttle_conn(ssh, +1);
5522 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5524 ssh->exitcode = ssh_pkt_getuint32(pktin);
5525 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5526 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5528 * In case `helpful' firewalls or proxies tack
5529 * extra human-readable text on the end of the
5530 * session which we might mistake for another
5531 * encrypted packet, we close the session once
5532 * we've sent EXIT_CONFIRMATION.
5534 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5537 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5538 static void ssh1_send_ttymode(void *data, char *mode, char *val)
5540 struct Packet *pktout = (struct Packet *)data;
5542 unsigned int arg = 0;
5543 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5544 if (i == lenof(ssh_ttymodes)) return;
5545 switch (ssh_ttymodes[i].type) {
5547 arg = ssh_tty_parse_specchar(val);
5550 arg = ssh_tty_parse_boolean(val);
5553 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5554 ssh2_pkt_addbyte(pktout, arg);
5557 int ssh_agent_forwarding_permitted(Ssh ssh)
5559 return conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists();
5562 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
5563 struct Packet *pktin)
5565 crBegin(ssh->do_ssh1_connection_crstate);
5567 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5568 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5569 ssh1_smsg_stdout_stderr_data;
5571 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5572 ssh1_msg_channel_open_confirmation;
5573 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5574 ssh1_msg_channel_open_failure;
5575 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5576 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5577 ssh1_msg_channel_close;
5578 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5579 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5581 if (ssh_agent_forwarding_permitted(ssh)) {
5582 logevent("Requesting agent forwarding");
5583 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5587 if (pktin->type != SSH1_SMSG_SUCCESS
5588 && pktin->type != SSH1_SMSG_FAILURE) {
5589 bombout(("Protocol confusion"));
5591 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5592 logevent("Agent forwarding refused");
5594 logevent("Agent forwarding enabled");
5595 ssh->agentfwd_enabled = TRUE;
5596 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5600 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
5602 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5604 if (!ssh->x11disp) {
5605 /* FIXME: return an error message from x11_setup_display */
5606 logevent("X11 forwarding not enabled: unable to"
5607 " initialise X display");
5609 ssh->x11auth = x11_invent_fake_auth
5610 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
5611 ssh->x11auth->disp = ssh->x11disp;
5613 logevent("Requesting X11 forwarding");
5614 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5615 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5616 PKT_STR, ssh->x11auth->protoname,
5617 PKT_STR, ssh->x11auth->datastring,
5618 PKT_INT, ssh->x11disp->screennum,
5621 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5622 PKT_STR, ssh->x11auth->protoname,
5623 PKT_STR, ssh->x11auth->datastring,
5629 if (pktin->type != SSH1_SMSG_SUCCESS
5630 && pktin->type != SSH1_SMSG_FAILURE) {
5631 bombout(("Protocol confusion"));
5633 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5634 logevent("X11 forwarding refused");
5636 logevent("X11 forwarding enabled");
5637 ssh->X11_fwd_enabled = TRUE;
5638 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5643 ssh_setup_portfwd(ssh, ssh->conf);
5644 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5646 if (!conf_get_int(ssh->conf, CONF_nopty)) {
5648 /* Unpick the terminal-speed string. */
5649 /* XXX perhaps we should allow no speeds to be sent. */
5650 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5651 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
5652 /* Send the pty request. */
5653 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5654 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
5655 ssh_pkt_adduint32(pkt, ssh->term_height);
5656 ssh_pkt_adduint32(pkt, ssh->term_width);
5657 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5658 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5659 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
5660 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5661 ssh_pkt_adduint32(pkt, ssh->ispeed);
5662 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5663 ssh_pkt_adduint32(pkt, ssh->ospeed);
5664 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5666 ssh->state = SSH_STATE_INTERMED;
5670 if (pktin->type != SSH1_SMSG_SUCCESS
5671 && pktin->type != SSH1_SMSG_FAILURE) {
5672 bombout(("Protocol confusion"));
5674 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5675 c_write_str(ssh, "Server refused to allocate pty\r\n");
5676 ssh->editing = ssh->echoing = 1;
5678 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5679 ssh->ospeed, ssh->ispeed);
5680 ssh->got_pty = TRUE;
5683 ssh->editing = ssh->echoing = 1;
5686 if (conf_get_int(ssh->conf, CONF_compression)) {
5687 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5691 if (pktin->type != SSH1_SMSG_SUCCESS
5692 && pktin->type != SSH1_SMSG_FAILURE) {
5693 bombout(("Protocol confusion"));
5695 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5696 c_write_str(ssh, "Server refused to compress\r\n");
5698 logevent("Started compression");
5699 ssh->v1_compressing = TRUE;
5700 ssh->cs_comp_ctx = zlib_compress_init();
5701 logevent("Initialised zlib (RFC1950) compression");
5702 ssh->sc_comp_ctx = zlib_decompress_init();
5703 logevent("Initialised zlib (RFC1950) decompression");
5707 * Start the shell or command.
5709 * Special case: if the first-choice command is an SSH-2
5710 * subsystem (hence not usable here) and the second choice
5711 * exists, we fall straight back to that.
5714 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
5716 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
5717 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
5718 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
5719 ssh->fallback_cmd = TRUE;
5722 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
5724 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
5725 logevent("Started session");
5728 ssh->state = SSH_STATE_SESSION;
5729 if (ssh->size_needed)
5730 ssh_size(ssh, ssh->term_width, ssh->term_height);
5731 if (ssh->eof_needed)
5732 ssh_special(ssh, TS_EOF);
5735 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5737 ssh->channels = newtree234(ssh_channelcmp);
5741 * By this point, most incoming packets are already being
5742 * handled by the dispatch table, and we need only pay
5743 * attention to the unusual ones.
5748 if (pktin->type == SSH1_SMSG_SUCCESS) {
5749 /* may be from EXEC_SHELL on some servers */
5750 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5751 /* may be from EXEC_SHELL on some servers
5752 * if no pty is available or in other odd cases. Ignore */
5754 bombout(("Strange packet received: type %d", pktin->type));
5759 int len = min(inlen, 512);
5760 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
5761 PKT_INT, len, PKT_DATA, in, len,
5773 * Handle the top-level SSH-2 protocol.
5775 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
5780 ssh_pkt_getstring(pktin, &msg, &msglen);
5781 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
5784 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
5786 /* log reason code in disconnect message */
5790 ssh_pkt_getstring(pktin, &msg, &msglen);
5791 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
5794 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
5796 /* Do nothing, because we're ignoring it! Duhh. */
5799 static void ssh1_protocol_setup(Ssh ssh)
5804 * Most messages are handled by the coroutines.
5806 for (i = 0; i < 256; i++)
5807 ssh->packet_dispatch[i] = NULL;
5810 * These special message types we install handlers for.
5812 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
5813 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
5814 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
5817 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
5818 struct Packet *pktin)
5820 unsigned char *in=(unsigned char*)vin;
5821 if (ssh->state == SSH_STATE_CLOSED)
5824 if (pktin && ssh->packet_dispatch[pktin->type]) {
5825 ssh->packet_dispatch[pktin->type](ssh, pktin);
5829 if (!ssh->protocol_initial_phase_done) {
5830 if (do_ssh1_login(ssh, in, inlen, pktin))
5831 ssh->protocol_initial_phase_done = TRUE;
5836 do_ssh1_connection(ssh, in, inlen, pktin);
5840 * Utility routine for decoding comma-separated strings in KEXINIT.
5842 static int in_commasep_string(char *needle, char *haystack, int haylen)
5845 if (!needle || !haystack) /* protect against null pointers */
5847 needlen = strlen(needle);
5850 * Is it at the start of the string?
5852 if (haylen >= needlen && /* haystack is long enough */
5853 !memcmp(needle, haystack, needlen) && /* initial match */
5854 (haylen == needlen || haystack[needlen] == ',')
5855 /* either , or EOS follows */
5859 * If not, search for the next comma and resume after that.
5860 * If no comma found, terminate.
5862 while (haylen > 0 && *haystack != ',')
5863 haylen--, haystack++;
5866 haylen--, haystack++; /* skip over comma itself */
5871 * Similar routine for checking whether we have the first string in a list.
5873 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
5876 if (!needle || !haystack) /* protect against null pointers */
5878 needlen = strlen(needle);
5880 * Is it at the start of the string?
5882 if (haylen >= needlen && /* haystack is long enough */
5883 !memcmp(needle, haystack, needlen) && /* initial match */
5884 (haylen == needlen || haystack[needlen] == ',')
5885 /* either , or EOS follows */
5893 * SSH-2 key creation method.
5894 * (Currently assumes 2 lots of any hash are sufficient to generate
5895 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
5897 #define SSH2_MKKEY_ITERS (2)
5898 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
5899 unsigned char *keyspace)
5901 const struct ssh_hash *h = ssh->kex->hash;
5903 /* First hlen bytes. */
5905 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5906 hash_mpint(h, s, K);
5907 h->bytes(s, H, h->hlen);
5908 h->bytes(s, &chr, 1);
5909 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
5910 h->final(s, keyspace);
5911 /* Next hlen bytes. */
5913 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5914 hash_mpint(h, s, K);
5915 h->bytes(s, H, h->hlen);
5916 h->bytes(s, keyspace, h->hlen);
5917 h->final(s, keyspace + h->hlen);
5921 * Handle the SSH-2 transport layer.
5923 static void do_ssh2_transport(Ssh ssh, void *vin, int inlen,
5924 struct Packet *pktin)
5926 unsigned char *in = (unsigned char *)vin;
5927 struct do_ssh2_transport_state {
5929 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
5930 Bignum p, g, e, f, K;
5933 int kex_init_value, kex_reply_value;
5934 const struct ssh_mac **maclist;
5936 const struct ssh2_cipher *cscipher_tobe;
5937 const struct ssh2_cipher *sccipher_tobe;
5938 const struct ssh_mac *csmac_tobe;
5939 const struct ssh_mac *scmac_tobe;
5940 const struct ssh_compress *cscomp_tobe;
5941 const struct ssh_compress *sccomp_tobe;
5942 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
5943 int hostkeylen, siglen, rsakeylen;
5944 void *hkey; /* actual host key */
5945 void *rsakey; /* for RSA kex */
5946 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
5947 int n_preferred_kex;
5948 const struct ssh_kexes *preferred_kex[KEX_MAX];
5949 int n_preferred_ciphers;
5950 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
5951 const struct ssh_compress *preferred_comp;
5952 int userauth_succeeded; /* for delayed compression */
5953 int pending_compression;
5954 int got_session_id, activated_authconn;
5955 struct Packet *pktout;
5960 crState(do_ssh2_transport_state);
5962 assert(!ssh->bare_connection);
5966 s->cscipher_tobe = s->sccipher_tobe = NULL;
5967 s->csmac_tobe = s->scmac_tobe = NULL;
5968 s->cscomp_tobe = s->sccomp_tobe = NULL;
5970 s->got_session_id = s->activated_authconn = FALSE;
5971 s->userauth_succeeded = FALSE;
5972 s->pending_compression = FALSE;
5975 * Be prepared to work around the buggy MAC problem.
5977 if (ssh->remote_bugs & BUG_SSH2_HMAC)
5978 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
5980 s->maclist = macs, s->nmacs = lenof(macs);
5983 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
5985 int i, j, k, commalist_started;
5988 * Set up the preferred key exchange. (NULL => warn below here)
5990 s->n_preferred_kex = 0;
5991 for (i = 0; i < KEX_MAX; i++) {
5992 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
5994 s->preferred_kex[s->n_preferred_kex++] =
5995 &ssh_diffiehellman_gex;
5998 s->preferred_kex[s->n_preferred_kex++] =
5999 &ssh_diffiehellman_group14;
6002 s->preferred_kex[s->n_preferred_kex++] =
6003 &ssh_diffiehellman_group1;
6006 s->preferred_kex[s->n_preferred_kex++] =
6010 /* Flag for later. Don't bother if it's the last in
6012 if (i < KEX_MAX - 1) {
6013 s->preferred_kex[s->n_preferred_kex++] = NULL;
6020 * Set up the preferred ciphers. (NULL => warn below here)
6022 s->n_preferred_ciphers = 0;
6023 for (i = 0; i < CIPHER_MAX; i++) {
6024 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
6025 case CIPHER_BLOWFISH:
6026 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
6029 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
6030 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
6034 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
6037 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
6039 case CIPHER_ARCFOUR:
6040 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
6043 /* Flag for later. Don't bother if it's the last in
6045 if (i < CIPHER_MAX - 1) {
6046 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
6053 * Set up preferred compression.
6055 if (conf_get_int(ssh->conf, CONF_compression))
6056 s->preferred_comp = &ssh_zlib;
6058 s->preferred_comp = &ssh_comp_none;
6061 * Enable queueing of outgoing auth- or connection-layer
6062 * packets while we are in the middle of a key exchange.
6064 ssh->queueing = TRUE;
6067 * Flag that KEX is in progress.
6069 ssh->kex_in_progress = TRUE;
6072 * Construct and send our key exchange packet.
6074 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
6075 for (i = 0; i < 16; i++)
6076 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
6077 /* List key exchange algorithms. */
6078 ssh2_pkt_addstring_start(s->pktout);
6079 commalist_started = 0;
6080 for (i = 0; i < s->n_preferred_kex; i++) {
6081 const struct ssh_kexes *k = s->preferred_kex[i];
6082 if (!k) continue; /* warning flag */
6083 for (j = 0; j < k->nkexes; j++) {
6084 if (commalist_started)
6085 ssh2_pkt_addstring_str(s->pktout, ",");
6086 ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
6087 commalist_started = 1;
6090 /* List server host key algorithms. */
6091 if (!s->got_session_id) {
6093 * In the first key exchange, we list all the algorithms
6094 * we're prepared to cope with.
6096 ssh2_pkt_addstring_start(s->pktout);
6097 for (i = 0; i < lenof(hostkey_algs); i++) {
6098 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
6099 if (i < lenof(hostkey_algs) - 1)
6100 ssh2_pkt_addstring_str(s->pktout, ",");
6104 * In subsequent key exchanges, we list only the kex
6105 * algorithm that was selected in the first key exchange,
6106 * so that we keep getting the same host key and hence
6107 * don't have to interrupt the user's session to ask for
6111 ssh2_pkt_addstring(s->pktout, ssh->hostkey->name);
6113 /* List encryption algorithms (client->server then server->client). */
6114 for (k = 0; k < 2; k++) {
6115 ssh2_pkt_addstring_start(s->pktout);
6116 commalist_started = 0;
6117 for (i = 0; i < s->n_preferred_ciphers; i++) {
6118 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6119 if (!c) continue; /* warning flag */
6120 for (j = 0; j < c->nciphers; j++) {
6121 if (commalist_started)
6122 ssh2_pkt_addstring_str(s->pktout, ",");
6123 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
6124 commalist_started = 1;
6128 /* List MAC algorithms (client->server then server->client). */
6129 for (j = 0; j < 2; j++) {
6130 ssh2_pkt_addstring_start(s->pktout);
6131 for (i = 0; i < s->nmacs; i++) {
6132 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
6133 if (i < s->nmacs - 1)
6134 ssh2_pkt_addstring_str(s->pktout, ",");
6137 /* List client->server compression algorithms,
6138 * then server->client compression algorithms. (We use the
6139 * same set twice.) */
6140 for (j = 0; j < 2; j++) {
6141 ssh2_pkt_addstring_start(s->pktout);
6142 assert(lenof(compressions) > 1);
6143 /* Prefer non-delayed versions */
6144 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
6145 /* We don't even list delayed versions of algorithms until
6146 * they're allowed to be used, to avoid a race. See the end of
6148 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
6149 ssh2_pkt_addstring_str(s->pktout, ",");
6150 ssh2_pkt_addstring_str(s->pktout,
6151 s->preferred_comp->delayed_name);
6153 for (i = 0; i < lenof(compressions); i++) {
6154 const struct ssh_compress *c = compressions[i];
6155 if (c != s->preferred_comp) {
6156 ssh2_pkt_addstring_str(s->pktout, ",");
6157 ssh2_pkt_addstring_str(s->pktout, c->name);
6158 if (s->userauth_succeeded && c->delayed_name) {
6159 ssh2_pkt_addstring_str(s->pktout, ",");
6160 ssh2_pkt_addstring_str(s->pktout, c->delayed_name);
6165 /* List client->server languages. Empty list. */
6166 ssh2_pkt_addstring_start(s->pktout);
6167 /* List server->client languages. Empty list. */
6168 ssh2_pkt_addstring_start(s->pktout);
6169 /* First KEX packet does _not_ follow, because we're not that brave. */
6170 ssh2_pkt_addbool(s->pktout, FALSE);
6172 ssh2_pkt_adduint32(s->pktout, 0);
6175 s->our_kexinitlen = s->pktout->length - 5;
6176 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
6177 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
6179 ssh2_pkt_send_noqueue(ssh, s->pktout);
6182 crWaitUntilV(pktin);
6185 * Now examine the other side's KEXINIT to see what we're up
6189 char *str, *preferred;
6192 if (pktin->type != SSH2_MSG_KEXINIT) {
6193 bombout(("expected key exchange packet from server"));
6197 ssh->hostkey = NULL;
6198 s->cscipher_tobe = NULL;
6199 s->sccipher_tobe = NULL;
6200 s->csmac_tobe = NULL;
6201 s->scmac_tobe = NULL;
6202 s->cscomp_tobe = NULL;
6203 s->sccomp_tobe = NULL;
6204 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
6206 pktin->savedpos += 16; /* skip garbage cookie */
6207 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
6210 for (i = 0; i < s->n_preferred_kex; i++) {
6211 const struct ssh_kexes *k = s->preferred_kex[i];
6215 for (j = 0; j < k->nkexes; j++) {
6216 if (!preferred) preferred = k->list[j]->name;
6217 if (in_commasep_string(k->list[j]->name, str, len)) {
6218 ssh->kex = k->list[j];
6227 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
6228 str ? str : "(null)"));
6232 * Note that the server's guess is considered wrong if it doesn't match
6233 * the first algorithm in our list, even if it's still the algorithm
6236 s->guessok = first_in_commasep_string(preferred, str, len);
6237 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
6238 for (i = 0; i < lenof(hostkey_algs); i++) {
6239 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
6240 ssh->hostkey = hostkey_algs[i];
6244 if (!ssh->hostkey) {
6245 bombout(("Couldn't agree a host key algorithm (available: %s)",
6246 str ? str : "(null)"));
6250 s->guessok = s->guessok &&
6251 first_in_commasep_string(hostkey_algs[0]->name, str, len);
6252 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
6253 for (i = 0; i < s->n_preferred_ciphers; i++) {
6254 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6256 s->warn_cscipher = TRUE;
6258 for (j = 0; j < c->nciphers; j++) {
6259 if (in_commasep_string(c->list[j]->name, str, len)) {
6260 s->cscipher_tobe = c->list[j];
6265 if (s->cscipher_tobe)
6268 if (!s->cscipher_tobe) {
6269 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
6270 str ? str : "(null)"));
6274 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
6275 for (i = 0; i < s->n_preferred_ciphers; i++) {
6276 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6278 s->warn_sccipher = TRUE;
6280 for (j = 0; j < c->nciphers; j++) {
6281 if (in_commasep_string(c->list[j]->name, str, len)) {
6282 s->sccipher_tobe = c->list[j];
6287 if (s->sccipher_tobe)
6290 if (!s->sccipher_tobe) {
6291 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
6292 str ? str : "(null)"));
6296 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
6297 for (i = 0; i < s->nmacs; i++) {
6298 if (in_commasep_string(s->maclist[i]->name, str, len)) {
6299 s->csmac_tobe = s->maclist[i];
6303 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
6304 for (i = 0; i < s->nmacs; i++) {
6305 if (in_commasep_string(s->maclist[i]->name, str, len)) {
6306 s->scmac_tobe = s->maclist[i];
6310 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
6311 for (i = 0; i < lenof(compressions) + 1; i++) {
6312 const struct ssh_compress *c =
6313 i == 0 ? s->preferred_comp : compressions[i - 1];
6314 if (in_commasep_string(c->name, str, len)) {
6317 } else if (in_commasep_string(c->delayed_name, str, len)) {
6318 if (s->userauth_succeeded) {
6322 s->pending_compression = TRUE; /* try this later */
6326 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
6327 for (i = 0; i < lenof(compressions) + 1; i++) {
6328 const struct ssh_compress *c =
6329 i == 0 ? s->preferred_comp : compressions[i - 1];
6330 if (in_commasep_string(c->name, str, len)) {
6333 } else if (in_commasep_string(c->delayed_name, str, len)) {
6334 if (s->userauth_succeeded) {
6338 s->pending_compression = TRUE; /* try this later */
6342 if (s->pending_compression) {
6343 logevent("Server supports delayed compression; "
6344 "will try this later");
6346 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
6347 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
6348 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
6350 ssh->exhash = ssh->kex->hash->init();
6351 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
6352 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
6353 hash_string(ssh->kex->hash, ssh->exhash,
6354 s->our_kexinit, s->our_kexinitlen);
6355 sfree(s->our_kexinit);
6356 /* Include the type byte in the hash of server's KEXINIT */
6357 hash_string(ssh->kex->hash, ssh->exhash,
6358 pktin->body - 1, pktin->length + 1);
6361 ssh_set_frozen(ssh, 1);
6362 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
6364 ssh_dialog_callback, ssh);
6365 if (s->dlgret < 0) {
6369 bombout(("Unexpected data from server while"
6370 " waiting for user response"));
6373 } while (pktin || inlen > 0);
6374 s->dlgret = ssh->user_response;
6376 ssh_set_frozen(ssh, 0);
6377 if (s->dlgret == 0) {
6378 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
6384 if (s->warn_cscipher) {
6385 ssh_set_frozen(ssh, 1);
6386 s->dlgret = askalg(ssh->frontend,
6387 "client-to-server cipher",
6388 s->cscipher_tobe->name,
6389 ssh_dialog_callback, ssh);
6390 if (s->dlgret < 0) {
6394 bombout(("Unexpected data from server while"
6395 " waiting for user response"));
6398 } while (pktin || inlen > 0);
6399 s->dlgret = ssh->user_response;
6401 ssh_set_frozen(ssh, 0);
6402 if (s->dlgret == 0) {
6403 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6409 if (s->warn_sccipher) {
6410 ssh_set_frozen(ssh, 1);
6411 s->dlgret = askalg(ssh->frontend,
6412 "server-to-client cipher",
6413 s->sccipher_tobe->name,
6414 ssh_dialog_callback, ssh);
6415 if (s->dlgret < 0) {
6419 bombout(("Unexpected data from server while"
6420 " waiting for user response"));
6423 } while (pktin || inlen > 0);
6424 s->dlgret = ssh->user_response;
6426 ssh_set_frozen(ssh, 0);
6427 if (s->dlgret == 0) {
6428 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6434 if (s->ignorepkt) /* first_kex_packet_follows */
6435 crWaitUntilV(pktin); /* Ignore packet */
6438 if (ssh->kex->main_type == KEXTYPE_DH) {
6440 * Work out the number of bits of key we will need from the
6441 * key exchange. We start with the maximum key length of
6447 csbits = s->cscipher_tobe->keylen;
6448 scbits = s->sccipher_tobe->keylen;
6449 s->nbits = (csbits > scbits ? csbits : scbits);
6451 /* The keys only have hlen-bit entropy, since they're based on
6452 * a hash. So cap the key size at hlen bits. */
6453 if (s->nbits > ssh->kex->hash->hlen * 8)
6454 s->nbits = ssh->kex->hash->hlen * 8;
6457 * If we're doing Diffie-Hellman group exchange, start by
6458 * requesting a group.
6460 if (!ssh->kex->pdata) {
6461 logevent("Doing Diffie-Hellman group exchange");
6462 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
6464 * Work out how big a DH group we will need to allow that
6467 s->pbits = 512 << ((s->nbits - 1) / 64);
6468 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6469 ssh2_pkt_adduint32(s->pktout, s->pbits);
6470 ssh2_pkt_send_noqueue(ssh, s->pktout);
6472 crWaitUntilV(pktin);
6473 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6474 bombout(("expected key exchange group packet from server"));
6477 s->p = ssh2_pkt_getmp(pktin);
6478 s->g = ssh2_pkt_getmp(pktin);
6479 if (!s->p || !s->g) {
6480 bombout(("unable to read mp-ints from incoming group packet"));
6483 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6484 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6485 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6487 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
6488 ssh->kex_ctx = dh_setup_group(ssh->kex);
6489 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6490 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6491 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6492 ssh->kex->groupname);
6495 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6496 ssh->kex->hash->text_name);
6498 * Now generate and send e for Diffie-Hellman.
6500 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6501 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6502 s->pktout = ssh2_pkt_init(s->kex_init_value);
6503 ssh2_pkt_addmp(s->pktout, s->e);
6504 ssh2_pkt_send_noqueue(ssh, s->pktout);
6506 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
6507 crWaitUntilV(pktin);
6508 if (pktin->type != s->kex_reply_value) {
6509 bombout(("expected key exchange reply packet from server"));
6512 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
6513 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6514 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6515 s->f = ssh2_pkt_getmp(pktin);
6517 bombout(("unable to parse key exchange reply packet"));
6520 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6522 s->K = dh_find_K(ssh->kex_ctx, s->f);
6524 /* We assume everything from now on will be quick, and it might
6525 * involve user interaction. */
6526 set_busy_status(ssh->frontend, BUSY_NOT);
6528 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6529 if (!ssh->kex->pdata) {
6530 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
6531 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
6532 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
6534 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
6535 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
6537 dh_cleanup(ssh->kex_ctx);
6539 if (!ssh->kex->pdata) {
6544 logeventf(ssh, "Doing RSA key exchange with hash %s",
6545 ssh->kex->hash->text_name);
6546 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
6548 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6551 crWaitUntilV(pktin);
6552 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
6553 bombout(("expected RSA public key packet from server"));
6557 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6558 hash_string(ssh->kex->hash, ssh->exhash,
6559 s->hostkeydata, s->hostkeylen);
6560 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6564 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
6565 s->rsakeydata = snewn(s->rsakeylen, char);
6566 memcpy(s->rsakeydata, keydata, s->rsakeylen);
6569 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
6571 sfree(s->rsakeydata);
6572 bombout(("unable to parse RSA public key from server"));
6576 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
6579 * Next, set up a shared secret K, of precisely KLEN -
6580 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6581 * RSA key modulus and HLEN is the bit length of the hash
6585 int klen = ssh_rsakex_klen(s->rsakey);
6586 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
6588 unsigned char *kstr1, *kstr2, *outstr;
6589 int kstr1len, kstr2len, outstrlen;
6591 s->K = bn_power_2(nbits - 1);
6593 for (i = 0; i < nbits; i++) {
6595 byte = random_byte();
6597 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
6601 * Encode this as an mpint.
6603 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
6604 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
6605 PUT_32BIT(kstr2, kstr1len);
6606 memcpy(kstr2 + 4, kstr1, kstr1len);
6609 * Encrypt it with the given RSA key.
6611 outstrlen = (klen + 7) / 8;
6612 outstr = snewn(outstrlen, unsigned char);
6613 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
6614 outstr, outstrlen, s->rsakey);
6617 * And send it off in a return packet.
6619 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
6620 ssh2_pkt_addstring_start(s->pktout);
6621 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
6622 ssh2_pkt_send_noqueue(ssh, s->pktout);
6624 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
6631 ssh_rsakex_freekey(s->rsakey);
6633 crWaitUntilV(pktin);
6634 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
6635 sfree(s->rsakeydata);
6636 bombout(("expected signature packet from server"));
6640 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6642 sfree(s->rsakeydata);
6645 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
6646 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
6647 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
6649 ssh->kex_ctx = NULL;
6652 debug(("Exchange hash is:\n"));
6653 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
6657 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
6658 (char *)s->exchange_hash,
6659 ssh->kex->hash->hlen)) {
6660 bombout(("Server's host key did not match the signature supplied"));
6664 s->keystr = ssh->hostkey->fmtkey(s->hkey);
6665 if (!s->got_session_id) {
6667 * Authenticate remote host: verify host key. (We've already
6668 * checked the signature of the exchange hash.)
6670 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
6671 ssh_set_frozen(ssh, 1);
6672 s->dlgret = verify_ssh_host_key(ssh->frontend,
6673 ssh->savedhost, ssh->savedport,
6674 ssh->hostkey->keytype, s->keystr,
6676 ssh_dialog_callback, ssh);
6677 if (s->dlgret < 0) {
6681 bombout(("Unexpected data from server while waiting"
6682 " for user host key response"));
6685 } while (pktin || inlen > 0);
6686 s->dlgret = ssh->user_response;
6688 ssh_set_frozen(ssh, 0);
6689 if (s->dlgret == 0) {
6690 ssh_disconnect(ssh, "User aborted at host key verification", NULL,
6694 logevent("Host key fingerprint is:");
6695 logevent(s->fingerprint);
6696 sfree(s->fingerprint);
6698 * Save this host key, to check against the one presented in
6699 * subsequent rekeys.
6701 ssh->hostkey_str = s->keystr;
6704 * In a rekey, we never present an interactive host key
6705 * verification request to the user. Instead, we simply
6706 * enforce that the key we're seeing this time is identical to
6707 * the one we saw before.
6709 if (strcmp(ssh->hostkey_str, s->keystr)) {
6710 bombout(("Host key was different in repeat key exchange"));
6715 ssh->hostkey->freekey(s->hkey);
6718 * The exchange hash from the very first key exchange is also
6719 * the session id, used in session key construction and
6722 if (!s->got_session_id) {
6723 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
6724 memcpy(ssh->v2_session_id, s->exchange_hash,
6725 sizeof(s->exchange_hash));
6726 ssh->v2_session_id_len = ssh->kex->hash->hlen;
6727 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
6728 s->got_session_id = TRUE;
6732 * Send SSH2_MSG_NEWKEYS.
6734 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
6735 ssh2_pkt_send_noqueue(ssh, s->pktout);
6736 ssh->outgoing_data_size = 0; /* start counting from here */
6739 * We've sent client NEWKEYS, so create and initialise
6740 * client-to-server session keys.
6742 if (ssh->cs_cipher_ctx)
6743 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6744 ssh->cscipher = s->cscipher_tobe;
6745 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
6747 if (ssh->cs_mac_ctx)
6748 ssh->csmac->free_context(ssh->cs_mac_ctx);
6749 ssh->csmac = s->csmac_tobe;
6750 ssh->cs_mac_ctx = ssh->csmac->make_context();
6752 if (ssh->cs_comp_ctx)
6753 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6754 ssh->cscomp = s->cscomp_tobe;
6755 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
6758 * Set IVs on client-to-server keys. Here we use the exchange
6759 * hash from the _first_ key exchange.
6762 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6763 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6764 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
6765 assert((ssh->cscipher->keylen+7) / 8 <=
6766 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6767 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
6768 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
6769 assert(ssh->cscipher->blksize <=
6770 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6771 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
6772 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
6773 assert(ssh->csmac->len <=
6774 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6775 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
6776 smemclr(keyspace, sizeof(keyspace));
6779 logeventf(ssh, "Initialised %.200s client->server encryption",
6780 ssh->cscipher->text_name);
6781 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
6782 ssh->csmac->text_name);
6783 if (ssh->cscomp->text_name)
6784 logeventf(ssh, "Initialised %s compression",
6785 ssh->cscomp->text_name);
6788 * Now our end of the key exchange is complete, we can send all
6789 * our queued higher-layer packets.
6791 ssh->queueing = FALSE;
6792 ssh2_pkt_queuesend(ssh);
6795 * Expect SSH2_MSG_NEWKEYS from server.
6797 crWaitUntilV(pktin);
6798 if (pktin->type != SSH2_MSG_NEWKEYS) {
6799 bombout(("expected new-keys packet from server"));
6802 ssh->incoming_data_size = 0; /* start counting from here */
6805 * We've seen server NEWKEYS, so create and initialise
6806 * server-to-client session keys.
6808 if (ssh->sc_cipher_ctx)
6809 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6810 ssh->sccipher = s->sccipher_tobe;
6811 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
6813 if (ssh->sc_mac_ctx)
6814 ssh->scmac->free_context(ssh->sc_mac_ctx);
6815 ssh->scmac = s->scmac_tobe;
6816 ssh->sc_mac_ctx = ssh->scmac->make_context();
6818 if (ssh->sc_comp_ctx)
6819 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
6820 ssh->sccomp = s->sccomp_tobe;
6821 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
6824 * Set IVs on server-to-client keys. Here we use the exchange
6825 * hash from the _first_ key exchange.
6828 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6829 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6830 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
6831 assert((ssh->sccipher->keylen+7) / 8 <=
6832 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6833 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
6834 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
6835 assert(ssh->sccipher->blksize <=
6836 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6837 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
6838 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
6839 assert(ssh->scmac->len <=
6840 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6841 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
6842 smemclr(keyspace, sizeof(keyspace));
6844 logeventf(ssh, "Initialised %.200s server->client encryption",
6845 ssh->sccipher->text_name);
6846 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
6847 ssh->scmac->text_name);
6848 if (ssh->sccomp->text_name)
6849 logeventf(ssh, "Initialised %s decompression",
6850 ssh->sccomp->text_name);
6853 * Free shared secret.
6858 * Key exchange is over. Loop straight back round if we have a
6859 * deferred rekey reason.
6861 if (ssh->deferred_rekey_reason) {
6862 logevent(ssh->deferred_rekey_reason);
6864 ssh->deferred_rekey_reason = NULL;
6865 goto begin_key_exchange;
6869 * Otherwise, schedule a timer for our next rekey.
6871 ssh->kex_in_progress = FALSE;
6872 ssh->last_rekey = GETTICKCOUNT();
6873 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
6874 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
6878 * Now we're encrypting. Begin returning 1 to the protocol main
6879 * function so that other things can run on top of the
6880 * transport. If we ever see a KEXINIT, we must go back to the
6883 * We _also_ go back to the start if we see pktin==NULL and
6884 * inlen negative, because this is a special signal meaning
6885 * `initiate client-driven rekey', and `in' contains a message
6886 * giving the reason for the rekey.
6888 * inlen==-1 means always initiate a rekey;
6889 * inlen==-2 means that userauth has completed successfully and
6890 * we should consider rekeying (for delayed compression).
6892 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
6893 (!pktin && inlen < 0))) {
6895 if (!ssh->protocol_initial_phase_done) {
6896 ssh->protocol_initial_phase_done = TRUE;
6898 * Allow authconn to initialise itself.
6900 do_ssh2_authconn(ssh, NULL, 0, NULL);
6905 logevent("Server initiated key re-exchange");
6909 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
6910 * delayed compression, if it's available.
6912 * draft-miller-secsh-compression-delayed-00 says that you
6913 * negotiate delayed compression in the first key exchange, and
6914 * both sides start compressing when the server has sent
6915 * USERAUTH_SUCCESS. This has a race condition -- the server
6916 * can't know when the client has seen it, and thus which incoming
6917 * packets it should treat as compressed.
6919 * Instead, we do the initial key exchange without offering the
6920 * delayed methods, but note if the server offers them; when we
6921 * get here, if a delayed method was available that was higher
6922 * on our list than what we got, we initiate a rekey in which we
6923 * _do_ list the delayed methods (and hopefully get it as a
6924 * result). Subsequent rekeys will do the same.
6926 assert(!s->userauth_succeeded); /* should only happen once */
6927 s->userauth_succeeded = TRUE;
6928 if (!s->pending_compression)
6929 /* Can't see any point rekeying. */
6930 goto wait_for_rekey; /* this is utterly horrid */
6931 /* else fall through to rekey... */
6932 s->pending_compression = FALSE;
6935 * Now we've decided to rekey.
6937 * Special case: if the server bug is set that doesn't
6938 * allow rekeying, we give a different log message and
6939 * continue waiting. (If such a server _initiates_ a rekey,
6940 * we process it anyway!)
6942 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
6943 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
6945 /* Reset the counters, so that at least this message doesn't
6946 * hit the event log _too_ often. */
6947 ssh->outgoing_data_size = 0;
6948 ssh->incoming_data_size = 0;
6949 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
6951 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
6954 goto wait_for_rekey; /* this is still utterly horrid */
6956 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
6959 goto begin_key_exchange;
6965 * Add data to an SSH-2 channel output buffer.
6967 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
6970 bufchain_add(&c->v.v2.outbuffer, buf, len);
6974 * Attempt to send data on an SSH-2 channel.
6976 static int ssh2_try_send(struct ssh_channel *c)
6979 struct Packet *pktout;
6982 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
6985 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
6986 if ((unsigned)len > c->v.v2.remwindow)
6987 len = c->v.v2.remwindow;
6988 if ((unsigned)len > c->v.v2.remmaxpkt)
6989 len = c->v.v2.remmaxpkt;
6990 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
6991 ssh2_pkt_adduint32(pktout, c->remoteid);
6992 ssh2_pkt_addstring_start(pktout);
6993 ssh2_pkt_addstring_data(pktout, data, len);
6994 ssh2_pkt_send(ssh, pktout);
6995 bufchain_consume(&c->v.v2.outbuffer, len);
6996 c->v.v2.remwindow -= len;
7000 * After having sent as much data as we can, return the amount
7003 ret = bufchain_size(&c->v.v2.outbuffer);
7006 * And if there's no data pending but we need to send an EOF, send
7009 if (!ret && c->pending_eof)
7010 ssh_channel_try_eof(c);
7015 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
7018 if (c->closes & CLOSES_SENT_EOF)
7019 return; /* don't send on channels we've EOFed */
7020 bufsize = ssh2_try_send(c);
7023 case CHAN_MAINSESSION:
7024 /* stdin need not receive an unthrottle
7025 * notification since it will be polled */
7028 x11_unthrottle(c->u.x11.xconn);
7031 /* agent sockets are request/response and need no
7032 * buffer management */
7035 pfd_unthrottle(c->u.pfd.pf);
7041 static int ssh_is_simple(Ssh ssh)
7044 * We use the 'simple' variant of the SSH protocol if we're asked
7045 * to, except not if we're also doing connection-sharing (either
7046 * tunnelling our packets over an upstream or expecting to be
7047 * tunnelled over ourselves), since then the assumption that we
7048 * have only one channel to worry about is not true after all.
7050 return (conf_get_int(ssh->conf, CONF_ssh_simple) &&
7051 !ssh->bare_connection && !ssh->connshare);
7055 * Set up most of a new ssh_channel for SSH-2.
7057 static void ssh2_channel_init(struct ssh_channel *c)
7060 c->localid = alloc_channel_id(ssh);
7062 c->pending_eof = FALSE;
7063 c->throttling_conn = FALSE;
7064 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
7065 ssh_is_simple(ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
7066 c->v.v2.chanreq_head = NULL;
7067 c->v.v2.throttle_state = UNTHROTTLED;
7068 bufchain_init(&c->v.v2.outbuffer);
7072 * Construct the common parts of a CHANNEL_OPEN.
7074 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c, char *type)
7076 struct Packet *pktout;
7078 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7079 ssh2_pkt_addstring(pktout, type);
7080 ssh2_pkt_adduint32(pktout, c->localid);
7081 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7082 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7087 * CHANNEL_FAILURE doesn't come with any indication of what message
7088 * caused it, so we have to keep track of the outstanding
7089 * CHANNEL_REQUESTs ourselves.
7091 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
7092 cchandler_fn_t handler, void *ctx)
7094 struct outstanding_channel_request *ocr =
7095 snew(struct outstanding_channel_request);
7097 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7098 ocr->handler = handler;
7101 if (!c->v.v2.chanreq_head)
7102 c->v.v2.chanreq_head = ocr;
7104 c->v.v2.chanreq_tail->next = ocr;
7105 c->v.v2.chanreq_tail = ocr;
7109 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
7110 * NULL then a reply will be requested and the handler will be called
7111 * when it arrives. The returned packet is ready to have any
7112 * request-specific data added and be sent. Note that if a handler is
7113 * provided, it's essential that the request actually be sent.
7115 * The handler will usually be passed the response packet in pktin.
7116 * If pktin is NULL, this means that no reply will ever be forthcoming
7117 * (e.g. because the entire connection is being destroyed) and the
7118 * handler should free any storage it's holding.
7120 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c, char *type,
7121 cchandler_fn_t handler, void *ctx)
7123 struct Packet *pktout;
7125 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7126 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7127 ssh2_pkt_adduint32(pktout, c->remoteid);
7128 ssh2_pkt_addstring(pktout, type);
7129 ssh2_pkt_addbool(pktout, handler != NULL);
7130 if (handler != NULL)
7131 ssh2_queue_chanreq_handler(c, handler, ctx);
7136 * Potentially enlarge the window on an SSH-2 channel.
7138 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
7140 static void ssh2_set_window(struct ssh_channel *c, int newwin)
7145 * Never send WINDOW_ADJUST for a channel that the remote side has
7146 * already sent EOF on; there's no point, since it won't be
7147 * sending any more data anyway. Ditto if _we've_ already sent
7150 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
7154 * Also, never widen the window for an X11 channel when we're
7155 * still waiting to see its initial auth and may yet hand it off
7158 if (c->type == CHAN_X11 && c->u.x11.initial)
7162 * If the remote end has a habit of ignoring maxpkt, limit the
7163 * window so that it has no choice (assuming it doesn't ignore the
7166 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
7167 newwin = OUR_V2_MAXPKT;
7170 * Only send a WINDOW_ADJUST if there's significantly more window
7171 * available than the other end thinks there is. This saves us
7172 * sending a WINDOW_ADJUST for every character in a shell session.
7174 * "Significant" is arbitrarily defined as half the window size.
7176 if (newwin / 2 >= c->v.v2.locwindow) {
7177 struct Packet *pktout;
7181 * In order to keep track of how much window the client
7182 * actually has available, we'd like it to acknowledge each
7183 * WINDOW_ADJUST. We can't do that directly, so we accompany
7184 * it with a CHANNEL_REQUEST that has to be acknowledged.
7186 * This is only necessary if we're opening the window wide.
7187 * If we're not, then throughput is being constrained by
7188 * something other than the maximum window size anyway.
7190 if (newwin == c->v.v2.locmaxwin &&
7191 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
7192 up = snew(unsigned);
7193 *up = newwin - c->v.v2.locwindow;
7194 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
7195 ssh2_handle_winadj_response, up);
7196 ssh2_pkt_send(ssh, pktout);
7198 if (c->v.v2.throttle_state != UNTHROTTLED)
7199 c->v.v2.throttle_state = UNTHROTTLING;
7201 /* Pretend the WINDOW_ADJUST was acked immediately. */
7202 c->v.v2.remlocwin = newwin;
7203 c->v.v2.throttle_state = THROTTLED;
7205 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7206 ssh2_pkt_adduint32(pktout, c->remoteid);
7207 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
7208 ssh2_pkt_send(ssh, pktout);
7209 c->v.v2.locwindow = newwin;
7214 * Find the channel associated with a message. If there's no channel,
7215 * or it's not properly open, make a noise about it and return NULL.
7217 static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
7219 unsigned localid = ssh_pkt_getuint32(pktin);
7220 struct ssh_channel *c;
7222 c = find234(ssh->channels, &localid, ssh_channelfind);
7224 (c->type != CHAN_SHARING && c->halfopen &&
7225 pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
7226 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
7227 char *buf = dupprintf("Received %s for %s channel %u",
7228 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
7230 c ? "half-open" : "nonexistent", localid);
7231 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
7238 static void ssh2_handle_winadj_response(struct ssh_channel *c,
7239 struct Packet *pktin, void *ctx)
7241 unsigned *sizep = ctx;
7244 * Winadj responses should always be failures. However, at least
7245 * one server ("boks_sshd") is known to return SUCCESS for channel
7246 * requests it's never heard of, such as "winadj@putty". Raised
7247 * with foxt.com as bug 090916-090424, but for the sake of a quiet
7248 * life, we don't worry about what kind of response we got.
7251 c->v.v2.remlocwin += *sizep;
7254 * winadj messages are only sent when the window is fully open, so
7255 * if we get an ack of one, we know any pending unthrottle is
7258 if (c->v.v2.throttle_state == UNTHROTTLING)
7259 c->v.v2.throttle_state = UNTHROTTLED;
7262 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
7264 struct ssh_channel *c = ssh2_channel_msg(ssh, pktin);
7265 struct outstanding_channel_request *ocr;
7268 if (c->type == CHAN_SHARING) {
7269 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7270 pktin->body, pktin->length);
7273 ocr = c->v.v2.chanreq_head;
7275 ssh2_msg_unexpected(ssh, pktin);
7278 ocr->handler(c, pktin, ocr->ctx);
7279 c->v.v2.chanreq_head = ocr->next;
7282 * We may now initiate channel-closing procedures, if that
7283 * CHANNEL_REQUEST was the last thing outstanding before we send
7286 ssh2_channel_check_close(c);
7289 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
7291 struct ssh_channel *c;
7292 c = ssh2_channel_msg(ssh, pktin);
7295 if (c->type == CHAN_SHARING) {
7296 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7297 pktin->body, pktin->length);
7300 if (!(c->closes & CLOSES_SENT_EOF)) {
7301 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
7302 ssh2_try_send_and_unthrottle(ssh, c);
7306 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
7310 struct ssh_channel *c;
7311 c = ssh2_channel_msg(ssh, pktin);
7314 if (c->type == CHAN_SHARING) {
7315 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7316 pktin->body, pktin->length);
7319 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
7320 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
7321 return; /* extended but not stderr */
7322 ssh_pkt_getstring(pktin, &data, &length);
7325 c->v.v2.locwindow -= length;
7326 c->v.v2.remlocwin -= length;
7328 case CHAN_MAINSESSION:
7330 from_backend(ssh->frontend, pktin->type ==
7331 SSH2_MSG_CHANNEL_EXTENDED_DATA,
7335 bufsize = x11_send(c->u.x11.xconn, data, length);
7338 bufsize = pfd_send(c->u.pfd.pf, data, length);
7341 while (length > 0) {
7342 if (c->u.a.lensofar < 4) {
7343 unsigned int l = min(4 - c->u.a.lensofar,
7345 memcpy(c->u.a.msglen + c->u.a.lensofar,
7349 c->u.a.lensofar += l;
7351 if (c->u.a.lensofar == 4) {
7353 4 + GET_32BIT(c->u.a.msglen);
7354 c->u.a.message = snewn(c->u.a.totallen,
7356 memcpy(c->u.a.message, c->u.a.msglen, 4);
7358 if (c->u.a.lensofar >= 4 && length > 0) {
7360 min(c->u.a.totallen - c->u.a.lensofar,
7362 memcpy(c->u.a.message + c->u.a.lensofar,
7366 c->u.a.lensofar += l;
7368 if (c->u.a.lensofar == c->u.a.totallen) {
7371 c->u.a.outstanding_requests++;
7372 if (agent_query(c->u.a.message,
7375 ssh_agentf_callback, c))
7376 ssh_agentf_callback(c, reply, replylen);
7377 sfree(c->u.a.message);
7378 c->u.a.message = NULL;
7379 c->u.a.lensofar = 0;
7386 * If it looks like the remote end hit the end of its window,
7387 * and we didn't want it to do that, think about using a
7390 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
7391 c->v.v2.locmaxwin < 0x40000000)
7392 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
7394 * If we are not buffering too much data,
7395 * enlarge the window again at the remote side.
7396 * If we are buffering too much, we may still
7397 * need to adjust the window if the server's
7400 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
7401 c->v.v2.locmaxwin - bufsize : 0);
7403 * If we're either buffering way too much data, or if we're
7404 * buffering anything at all and we're in "simple" mode,
7405 * throttle the whole channel.
7407 if ((bufsize > c->v.v2.locmaxwin || (ssh_is_simple(ssh) && bufsize>0))
7408 && !c->throttling_conn) {
7409 c->throttling_conn = 1;
7410 ssh_throttle_conn(ssh, +1);
7415 static void ssh_check_termination(Ssh ssh)
7417 if (ssh->version == 2 &&
7418 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
7419 count234(ssh->channels) == 0 &&
7420 !(ssh->connshare && share_ndownstreams(ssh->connshare) > 0)) {
7422 * We used to send SSH_MSG_DISCONNECT here, because I'd
7423 * believed that _every_ conforming SSH-2 connection had to
7424 * end with a disconnect being sent by at least one side;
7425 * apparently I was wrong and it's perfectly OK to
7426 * unceremoniously slam the connection shut when you're done,
7427 * and indeed OpenSSH feels this is more polite than sending a
7428 * DISCONNECT. So now we don't.
7430 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
7434 void ssh_sharing_downstream_connected(Ssh ssh, unsigned id)
7436 logeventf(ssh, "Connection sharing downstream #%u connected", id);
7439 void ssh_sharing_downstream_disconnected(Ssh ssh, unsigned id)
7441 logeventf(ssh, "Connection sharing downstream #%u disconnected", id);
7442 ssh_check_termination(ssh);
7445 void ssh_sharing_logf(Ssh ssh, unsigned id, const char *logfmt, ...)
7450 va_start(ap, logfmt);
7451 buf = dupvprintf(logfmt, ap);
7454 logeventf(ssh, "Connection sharing downstream #%u: %s", id, buf);
7456 logeventf(ssh, "Connection sharing: %s", buf);
7460 static void ssh_channel_destroy(struct ssh_channel *c)
7465 case CHAN_MAINSESSION:
7466 ssh->mainchan = NULL;
7467 update_specials_menu(ssh->frontend);
7470 if (c->u.x11.xconn != NULL)
7471 x11_close(c->u.x11.xconn);
7472 logevent("Forwarded X11 connection terminated");
7475 sfree(c->u.a.message);
7478 if (c->u.pfd.pf != NULL)
7479 pfd_close(c->u.pfd.pf);
7480 logevent("Forwarded port closed");
7484 del234(ssh->channels, c);
7485 if (ssh->version == 2) {
7486 bufchain_clear(&c->v.v2.outbuffer);
7487 assert(c->v.v2.chanreq_head == NULL);
7492 * If that was the last channel left open, we might need to
7495 ssh_check_termination(ssh);
7498 static void ssh2_channel_check_close(struct ssh_channel *c)
7501 struct Packet *pktout;
7505 * If we've sent out our own CHANNEL_OPEN but not yet seen
7506 * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
7507 * it's too early to be sending close messages of any kind.
7512 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
7513 c->type == CHAN_ZOMBIE) &&
7514 !c->v.v2.chanreq_head &&
7515 !(c->closes & CLOSES_SENT_CLOSE)) {
7517 * We have both sent and received EOF (or the channel is a
7518 * zombie), and we have no outstanding channel requests, which
7519 * means the channel is in final wind-up. But we haven't sent
7520 * CLOSE, so let's do so now.
7522 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
7523 ssh2_pkt_adduint32(pktout, c->remoteid);
7524 ssh2_pkt_send(ssh, pktout);
7525 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
7528 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
7529 assert(c->v.v2.chanreq_head == NULL);
7531 * We have both sent and received CLOSE, which means we're
7532 * completely done with the channel.
7534 ssh_channel_destroy(c);
7538 static void ssh2_channel_got_eof(struct ssh_channel *c)
7540 if (c->closes & CLOSES_RCVD_EOF)
7541 return; /* already seen EOF */
7542 c->closes |= CLOSES_RCVD_EOF;
7544 if (c->type == CHAN_X11) {
7545 x11_send_eof(c->u.x11.xconn);
7546 } else if (c->type == CHAN_AGENT) {
7547 if (c->u.a.outstanding_requests == 0) {
7548 /* Manufacture an outgoing EOF in response to the incoming one. */
7549 sshfwd_write_eof(c);
7551 } else if (c->type == CHAN_SOCKDATA) {
7552 pfd_send_eof(c->u.pfd.pf);
7553 } else if (c->type == CHAN_MAINSESSION) {
7556 if (!ssh->sent_console_eof &&
7557 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
7559 * Either from_backend_eof told us that the front end
7560 * wants us to close the outgoing side of the connection
7561 * as soon as we see EOF from the far end, or else we've
7562 * unilaterally decided to do that because we've allocated
7563 * a remote pty and hence EOF isn't a particularly
7564 * meaningful concept.
7566 sshfwd_write_eof(c);
7568 ssh->sent_console_eof = TRUE;
7571 ssh2_channel_check_close(c);
7574 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
7576 struct ssh_channel *c;
7578 c = ssh2_channel_msg(ssh, pktin);
7581 if (c->type == CHAN_SHARING) {
7582 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7583 pktin->body, pktin->length);
7586 ssh2_channel_got_eof(c);
7589 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
7591 struct ssh_channel *c;
7593 c = ssh2_channel_msg(ssh, pktin);
7596 if (c->type == CHAN_SHARING) {
7597 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7598 pktin->body, pktin->length);
7603 * When we receive CLOSE on a channel, we assume it comes with an
7604 * implied EOF if we haven't seen EOF yet.
7606 ssh2_channel_got_eof(c);
7609 * And we also send an outgoing EOF, if we haven't already, on the
7610 * assumption that CLOSE is a pretty forceful announcement that
7611 * the remote side is doing away with the entire channel. (If it
7612 * had wanted to send us EOF and continue receiving data from us,
7613 * it would have just sent CHANNEL_EOF.)
7615 if (!(c->closes & CLOSES_SENT_EOF)) {
7617 * Make sure we don't read any more from whatever our local
7618 * data source is for this channel.
7621 case CHAN_MAINSESSION:
7622 ssh->send_ok = 0; /* stop trying to read from stdin */
7625 x11_override_throttle(c->u.x11.xconn, 1);
7628 pfd_override_throttle(c->u.pfd.pf, 1);
7633 * Abandon any buffered data we still wanted to send to this
7634 * channel. Receiving a CHANNEL_CLOSE is an indication that
7635 * the server really wants to get on and _destroy_ this
7636 * channel, and it isn't going to send us any further
7637 * WINDOW_ADJUSTs to permit us to send pending stuff.
7639 bufchain_clear(&c->v.v2.outbuffer);
7642 * Send outgoing EOF.
7644 sshfwd_write_eof(c);
7648 * Now process the actual close.
7650 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
7651 c->closes |= CLOSES_RCVD_CLOSE;
7652 ssh2_channel_check_close(c);
7656 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
7658 struct ssh_channel *c;
7660 c = ssh2_channel_msg(ssh, pktin);
7663 if (c->type == CHAN_SHARING) {
7664 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7665 pktin->body, pktin->length);
7668 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7669 c->remoteid = ssh_pkt_getuint32(pktin);
7670 c->halfopen = FALSE;
7671 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7672 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7674 if (c->type == CHAN_SOCKDATA_DORMANT) {
7675 c->type = CHAN_SOCKDATA;
7677 pfd_confirm(c->u.pfd.pf);
7678 } else if (c->type == CHAN_ZOMBIE) {
7680 * This case can occur if a local socket error occurred
7681 * between us sending out CHANNEL_OPEN and receiving
7682 * OPEN_CONFIRMATION. In this case, all we can do is
7683 * immediately initiate close proceedings now that we know the
7684 * server's id to put in the close message.
7686 ssh2_channel_check_close(c);
7689 * We never expect to receive OPEN_CONFIRMATION for any
7690 * *other* channel type (since only local-to-remote port
7691 * forwardings cause us to send CHANNEL_OPEN after the main
7692 * channel is live - all other auxiliary channel types are
7693 * initiated from the server end). It's safe to enforce this
7694 * by assertion rather than by ssh_disconnect, because the
7695 * real point is that we never constructed a half-open channel
7696 * structure in the first place with any type other than the
7699 assert(!"Funny channel type in ssh2_msg_channel_open_confirmation");
7703 ssh_channel_try_eof(c); /* in case we had a pending EOF */
7706 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
7708 static const char *const reasons[] = {
7709 "<unknown reason code>",
7710 "Administratively prohibited",
7712 "Unknown channel type",
7713 "Resource shortage",
7715 unsigned reason_code;
7716 char *reason_string;
7718 struct ssh_channel *c;
7720 c = ssh2_channel_msg(ssh, pktin);
7723 if (c->type == CHAN_SHARING) {
7724 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7725 pktin->body, pktin->length);
7728 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7730 if (c->type == CHAN_SOCKDATA_DORMANT) {
7731 reason_code = ssh_pkt_getuint32(pktin);
7732 if (reason_code >= lenof(reasons))
7733 reason_code = 0; /* ensure reasons[reason_code] in range */
7734 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
7735 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
7736 reasons[reason_code], reason_length, reason_string);
7738 pfd_close(c->u.pfd.pf);
7739 } else if (c->type == CHAN_ZOMBIE) {
7741 * This case can occur if a local socket error occurred
7742 * between us sending out CHANNEL_OPEN and receiving
7743 * OPEN_FAILURE. In this case, we need do nothing except allow
7744 * the code below to throw the half-open channel away.
7748 * We never expect to receive OPEN_FAILURE for any *other*
7749 * channel type (since only local-to-remote port forwardings
7750 * cause us to send CHANNEL_OPEN after the main channel is
7751 * live - all other auxiliary channel types are initiated from
7752 * the server end). It's safe to enforce this by assertion
7753 * rather than by ssh_disconnect, because the real point is
7754 * that we never constructed a half-open channel structure in
7755 * the first place with any type other than the above.
7757 assert(!"Funny channel type in ssh2_msg_channel_open_failure");
7760 del234(ssh->channels, c);
7764 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
7767 int typelen, want_reply;
7768 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
7769 struct ssh_channel *c;
7770 struct Packet *pktout;
7772 c = ssh2_channel_msg(ssh, pktin);
7775 if (c->type == CHAN_SHARING) {
7776 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7777 pktin->body, pktin->length);
7780 ssh_pkt_getstring(pktin, &type, &typelen);
7781 want_reply = ssh2_pkt_getbool(pktin);
7784 * Having got the channel number, we now look at
7785 * the request type string to see if it's something
7788 if (c == ssh->mainchan) {
7790 * We recognise "exit-status" and "exit-signal" on
7791 * the primary channel.
7793 if (typelen == 11 &&
7794 !memcmp(type, "exit-status", 11)) {
7796 ssh->exitcode = ssh_pkt_getuint32(pktin);
7797 logeventf(ssh, "Server sent command exit status %d",
7799 reply = SSH2_MSG_CHANNEL_SUCCESS;
7801 } else if (typelen == 11 &&
7802 !memcmp(type, "exit-signal", 11)) {
7804 int is_plausible = TRUE, is_int = FALSE;
7805 char *fmt_sig = "", *fmt_msg = "";
7807 int msglen = 0, core = FALSE;
7808 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
7809 * provide an `int' for the signal, despite its
7810 * having been a `string' in the drafts of RFC 4254 since at
7811 * least 2001. (Fixed in session.c 1.147.) Try to
7812 * infer which we can safely parse it as. */
7814 unsigned char *p = pktin->body +
7816 long len = pktin->length - pktin->savedpos;
7817 unsigned long num = GET_32BIT(p); /* what is it? */
7818 /* If it's 0, it hardly matters; assume string */
7822 int maybe_int = FALSE, maybe_str = FALSE;
7823 #define CHECK_HYPOTHESIS(offset, result) \
7826 int q = toint(offset); \
7827 if (q >= 0 && q+4 <= len) { \
7828 q = toint(q + 4 + GET_32BIT(p+q)); \
7829 if (q >= 0 && q+4 <= len && \
7830 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
7835 CHECK_HYPOTHESIS(4+1, maybe_int);
7836 CHECK_HYPOTHESIS(4+num+1, maybe_str);
7837 #undef CHECK_HYPOTHESIS
7838 if (maybe_int && !maybe_str)
7840 else if (!maybe_int && maybe_str)
7843 /* Crikey. Either or neither. Panic. */
7844 is_plausible = FALSE;
7847 ssh->exitcode = 128; /* means `unknown signal' */
7850 /* Old non-standard OpenSSH. */
7851 int signum = ssh_pkt_getuint32(pktin);
7852 fmt_sig = dupprintf(" %d", signum);
7853 ssh->exitcode = 128 + signum;
7855 /* As per RFC 4254. */
7858 ssh_pkt_getstring(pktin, &sig, &siglen);
7859 /* Signal name isn't supposed to be blank, but
7860 * let's cope gracefully if it is. */
7862 fmt_sig = dupprintf(" \"%.*s\"",
7867 * Really hideous method of translating the
7868 * signal description back into a locally
7869 * meaningful number.
7874 #define TRANSLATE_SIGNAL(s) \
7875 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
7876 ssh->exitcode = 128 + SIG ## s
7878 TRANSLATE_SIGNAL(ABRT);
7881 TRANSLATE_SIGNAL(ALRM);
7884 TRANSLATE_SIGNAL(FPE);
7887 TRANSLATE_SIGNAL(HUP);
7890 TRANSLATE_SIGNAL(ILL);
7893 TRANSLATE_SIGNAL(INT);
7896 TRANSLATE_SIGNAL(KILL);
7899 TRANSLATE_SIGNAL(PIPE);
7902 TRANSLATE_SIGNAL(QUIT);
7905 TRANSLATE_SIGNAL(SEGV);
7908 TRANSLATE_SIGNAL(TERM);
7911 TRANSLATE_SIGNAL(USR1);
7914 TRANSLATE_SIGNAL(USR2);
7916 #undef TRANSLATE_SIGNAL
7918 ssh->exitcode = 128;
7920 core = ssh2_pkt_getbool(pktin);
7921 ssh_pkt_getstring(pktin, &msg, &msglen);
7923 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
7925 /* ignore lang tag */
7926 } /* else don't attempt to parse */
7927 logeventf(ssh, "Server exited on signal%s%s%s",
7928 fmt_sig, core ? " (core dumped)" : "",
7930 if (*fmt_sig) sfree(fmt_sig);
7931 if (*fmt_msg) sfree(fmt_msg);
7932 reply = SSH2_MSG_CHANNEL_SUCCESS;
7937 * This is a channel request we don't know
7938 * about, so we now either ignore the request
7939 * or respond with CHANNEL_FAILURE, depending
7942 reply = SSH2_MSG_CHANNEL_FAILURE;
7945 pktout = ssh2_pkt_init(reply);
7946 ssh2_pkt_adduint32(pktout, c->remoteid);
7947 ssh2_pkt_send(ssh, pktout);
7951 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
7954 int typelen, want_reply;
7955 struct Packet *pktout;
7957 ssh_pkt_getstring(pktin, &type, &typelen);
7958 want_reply = ssh2_pkt_getbool(pktin);
7961 * We currently don't support any global requests
7962 * at all, so we either ignore the request or
7963 * respond with REQUEST_FAILURE, depending on
7967 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
7968 ssh2_pkt_send(ssh, pktout);
7972 struct X11FakeAuth *ssh_sharing_add_x11_display(Ssh ssh, int authtype,
7976 struct X11FakeAuth *auth;
7979 * Make up a new set of fake X11 auth data, and add it to the tree
7980 * of currently valid ones with an indication of the sharing
7981 * context that it's relevant to.
7983 auth = x11_invent_fake_auth(ssh->x11authtree, authtype);
7984 auth->share_cs = share_cs;
7985 auth->share_chan = share_chan;
7990 void ssh_sharing_remove_x11_display(Ssh ssh, struct X11FakeAuth *auth)
7992 del234(ssh->x11authtree, auth);
7993 x11_free_fake_auth(auth);
7996 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
8004 struct ssh_channel *c;
8005 unsigned remid, winsize, pktsize;
8006 unsigned our_winsize_override = 0;
8007 struct Packet *pktout;
8009 ssh_pkt_getstring(pktin, &type, &typelen);
8010 c = snew(struct ssh_channel);
8013 remid = ssh_pkt_getuint32(pktin);
8014 winsize = ssh_pkt_getuint32(pktin);
8015 pktsize = ssh_pkt_getuint32(pktin);
8017 if (typelen == 3 && !memcmp(type, "x11", 3)) {
8020 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8021 addrstr = snewn(peeraddrlen+1, char);
8022 memcpy(addrstr, peeraddr, peeraddrlen);
8023 addrstr[peeraddrlen] = '\0';
8024 peerport = ssh_pkt_getuint32(pktin);
8026 logeventf(ssh, "Received X11 connect request from %s:%d",
8029 if (!ssh->X11_fwd_enabled && !ssh->connshare)
8030 error = "X11 forwarding is not enabled";
8032 c->u.x11.xconn = x11_init(ssh->x11authtree, c,
8035 c->u.x11.initial = TRUE;
8038 * If we are a connection-sharing upstream, then we should
8039 * initially present a very small window, adequate to take
8040 * the X11 initial authorisation packet but not much more.
8041 * Downstream will then present us a larger window (by
8042 * fiat of the connection-sharing protocol) and we can
8043 * guarantee to send a positive-valued WINDOW_ADJUST.
8046 our_winsize_override = 128;
8048 logevent("Opened X11 forward channel");
8052 } else if (typelen == 15 &&
8053 !memcmp(type, "forwarded-tcpip", 15)) {
8054 struct ssh_rportfwd pf, *realpf;
8057 ssh_pkt_getstring(pktin, &shost, &shostlen);/* skip address */
8058 pf.shost = dupprintf("%.*s", shostlen, shost);
8059 pf.sport = ssh_pkt_getuint32(pktin);
8060 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8061 peerport = ssh_pkt_getuint32(pktin);
8062 realpf = find234(ssh->rportfwds, &pf, NULL);
8063 logeventf(ssh, "Received remote port %s:%d open request "
8064 "from %s:%d", pf.shost, pf.sport, peeraddr, peerport);
8067 if (realpf == NULL) {
8068 error = "Remote port is not recognised";
8072 if (realpf->share_ctx) {
8074 * This port forwarding is on behalf of a
8075 * connection-sharing downstream, so abandon our own
8076 * channel-open procedure and just pass the message on
8079 share_got_pkt_from_server(realpf->share_ctx, pktin->type,
8080 pktin->body, pktin->length);
8085 err = pfd_connect(&c->u.pfd.pf, realpf->dhost, realpf->dport,
8086 c, ssh->conf, realpf->pfrec->addressfamily);
8087 logeventf(ssh, "Attempting to forward remote port to "
8088 "%s:%d", realpf->dhost, realpf->dport);
8090 logeventf(ssh, "Port open failed: %s", err);
8092 error = "Port open failed";
8094 logevent("Forwarded port opened successfully");
8095 c->type = CHAN_SOCKDATA;
8098 } else if (typelen == 22 &&
8099 !memcmp(type, "auth-agent@openssh.com", 22)) {
8100 if (!ssh->agentfwd_enabled)
8101 error = "Agent forwarding is not enabled";
8103 c->type = CHAN_AGENT; /* identify channel type */
8104 c->u.a.lensofar = 0;
8105 c->u.a.message = NULL;
8106 c->u.a.outstanding_requests = 0;
8109 error = "Unsupported channel type requested";
8112 c->remoteid = remid;
8113 c->halfopen = FALSE;
8115 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
8116 ssh2_pkt_adduint32(pktout, c->remoteid);
8117 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
8118 ssh2_pkt_addstring(pktout, error);
8119 ssh2_pkt_addstring(pktout, "en"); /* language tag */
8120 ssh2_pkt_send(ssh, pktout);
8121 logeventf(ssh, "Rejected channel open: %s", error);
8124 ssh2_channel_init(c);
8125 c->v.v2.remwindow = winsize;
8126 c->v.v2.remmaxpkt = pktsize;
8127 if (our_winsize_override) {
8128 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
8129 our_winsize_override;
8131 add234(ssh->channels, c);
8132 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
8133 ssh2_pkt_adduint32(pktout, c->remoteid);
8134 ssh2_pkt_adduint32(pktout, c->localid);
8135 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
8136 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8137 ssh2_pkt_send(ssh, pktout);
8141 void sshfwd_x11_sharing_handover(struct ssh_channel *c,
8142 void *share_cs, void *share_chan,
8143 const char *peer_addr, int peer_port,
8144 int endian, int protomajor, int protominor,
8145 const void *initial_data, int initial_len)
8148 * This function is called when we've just discovered that an X
8149 * forwarding channel on which we'd been handling the initial auth
8150 * ourselves turns out to be destined for a connection-sharing
8151 * downstream. So we turn the channel into a CHAN_SHARING, meaning
8152 * that we completely stop tracking windows and buffering data and
8153 * just pass more or less unmodified SSH messages back and forth.
8155 c->type = CHAN_SHARING;
8156 c->u.sharing.ctx = share_cs;
8157 share_setup_x11_channel(share_cs, share_chan,
8158 c->localid, c->remoteid, c->v.v2.remwindow,
8159 c->v.v2.remmaxpkt, c->v.v2.locwindow,
8160 peer_addr, peer_port, endian,
8161 protomajor, protominor,
8162 initial_data, initial_len);
8165 void sshfwd_x11_is_local(struct ssh_channel *c)
8168 * This function is called when we've just discovered that an X
8169 * forwarding channel is _not_ destined for a connection-sharing
8170 * downstream but we're going to handle it ourselves. We stop
8171 * presenting a cautiously small window and go into ordinary data
8174 c->u.x11.initial = FALSE;
8175 ssh2_set_window(c, ssh_is_simple(c->ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE);
8179 * Buffer banner messages for later display at some convenient point,
8180 * if we're going to display them.
8182 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
8184 /* Arbitrary limit to prevent unbounded inflation of buffer */
8185 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
8186 bufchain_size(&ssh->banner) <= 131072) {
8187 char *banner = NULL;
8189 ssh_pkt_getstring(pktin, &banner, &size);
8191 bufchain_add(&ssh->banner, banner, size);
8195 /* Helper function to deal with sending tty modes for "pty-req" */
8196 static void ssh2_send_ttymode(void *data, char *mode, char *val)
8198 struct Packet *pktout = (struct Packet *)data;
8200 unsigned int arg = 0;
8201 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
8202 if (i == lenof(ssh_ttymodes)) return;
8203 switch (ssh_ttymodes[i].type) {
8205 arg = ssh_tty_parse_specchar(val);
8208 arg = ssh_tty_parse_boolean(val);
8211 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
8212 ssh2_pkt_adduint32(pktout, arg);
8215 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
8218 struct ssh2_setup_x11_state {
8222 struct Packet *pktout;
8223 crStateP(ssh2_setup_x11_state, ctx);
8227 logevent("Requesting X11 forwarding");
8228 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
8230 ssh2_pkt_addbool(pktout, 0); /* many connections */
8231 ssh2_pkt_addstring(pktout, ssh->x11auth->protoname);
8232 ssh2_pkt_addstring(pktout, ssh->x11auth->datastring);
8233 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
8234 ssh2_pkt_send(ssh, pktout);
8236 /* Wait to be called back with either a response packet, or NULL
8237 * meaning clean up and free our data */
8241 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8242 logevent("X11 forwarding enabled");
8243 ssh->X11_fwd_enabled = TRUE;
8245 logevent("X11 forwarding refused");
8251 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
8254 struct ssh2_setup_agent_state {
8258 struct Packet *pktout;
8259 crStateP(ssh2_setup_agent_state, ctx);
8263 logevent("Requesting OpenSSH-style agent forwarding");
8264 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
8265 ssh2_setup_agent, s);
8266 ssh2_pkt_send(ssh, pktout);
8268 /* Wait to be called back with either a response packet, or NULL
8269 * meaning clean up and free our data */
8273 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8274 logevent("Agent forwarding enabled");
8275 ssh->agentfwd_enabled = TRUE;
8277 logevent("Agent forwarding refused");
8283 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
8286 struct ssh2_setup_pty_state {
8290 struct Packet *pktout;
8291 crStateP(ssh2_setup_pty_state, ctx);
8295 /* Unpick the terminal-speed string. */
8296 /* XXX perhaps we should allow no speeds to be sent. */
8297 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
8298 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
8299 /* Build the pty request. */
8300 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
8302 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
8303 ssh2_pkt_adduint32(pktout, ssh->term_width);
8304 ssh2_pkt_adduint32(pktout, ssh->term_height);
8305 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
8306 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
8307 ssh2_pkt_addstring_start(pktout);
8308 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
8309 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
8310 ssh2_pkt_adduint32(pktout, ssh->ispeed);
8311 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
8312 ssh2_pkt_adduint32(pktout, ssh->ospeed);
8313 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
8314 ssh2_pkt_send(ssh, pktout);
8315 ssh->state = SSH_STATE_INTERMED;
8317 /* Wait to be called back with either a response packet, or NULL
8318 * meaning clean up and free our data */
8322 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8323 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
8324 ssh->ospeed, ssh->ispeed);
8325 ssh->got_pty = TRUE;
8327 c_write_str(ssh, "Server refused to allocate pty\r\n");
8328 ssh->editing = ssh->echoing = 1;
8335 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
8338 struct ssh2_setup_env_state {
8340 int num_env, env_left, env_ok;
8343 struct Packet *pktout;
8344 crStateP(ssh2_setup_env_state, ctx);
8349 * Send environment variables.
8351 * Simplest thing here is to send all the requests at once, and
8352 * then wait for a whole bunch of successes or failures.
8358 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
8360 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
8361 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
8362 ssh2_pkt_addstring(pktout, key);
8363 ssh2_pkt_addstring(pktout, val);
8364 ssh2_pkt_send(ssh, pktout);
8369 logeventf(ssh, "Sent %d environment variables", s->num_env);
8374 s->env_left = s->num_env;
8376 while (s->env_left > 0) {
8377 /* Wait to be called back with either a response packet,
8378 * or NULL meaning clean up and free our data */
8380 if (!pktin) goto out;
8381 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
8386 if (s->env_ok == s->num_env) {
8387 logevent("All environment variables successfully set");
8388 } else if (s->env_ok == 0) {
8389 logevent("All environment variables refused");
8390 c_write_str(ssh, "Server refused to set environment variables\r\n");
8392 logeventf(ssh, "%d environment variables refused",
8393 s->num_env - s->env_ok);
8394 c_write_str(ssh, "Server refused to set all environment variables\r\n");
8402 * Handle the SSH-2 userauth and connection layers.
8404 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
8406 do_ssh2_authconn(ssh, NULL, 0, pktin);
8409 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
8412 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
8415 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
8416 struct Packet *pktin)
8418 struct do_ssh2_authconn_state {
8422 AUTH_TYPE_PUBLICKEY,
8423 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
8424 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
8426 AUTH_TYPE_GSSAPI, /* always QUIET */
8427 AUTH_TYPE_KEYBOARD_INTERACTIVE,
8428 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
8430 int done_service_req;
8431 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
8432 int tried_pubkey_config, done_agent;
8437 int kbd_inter_refused;
8438 int we_are_in, userauth_success;
8439 prompts_t *cur_prompt;
8444 void *publickey_blob;
8445 int publickey_bloblen;
8446 int publickey_encrypted;
8447 char *publickey_algorithm;
8448 char *publickey_comment;
8449 unsigned char agent_request[5], *agent_response, *agentp;
8450 int agent_responselen;
8451 unsigned char *pkblob_in_agent;
8453 char *pkblob, *alg, *commentp;
8454 int pklen, alglen, commentlen;
8455 int siglen, retlen, len;
8456 char *q, *agentreq, *ret;
8458 struct Packet *pktout;
8461 struct ssh_gss_library *gsslib;
8462 Ssh_gss_ctx gss_ctx;
8463 Ssh_gss_buf gss_buf;
8464 Ssh_gss_buf gss_rcvtok, gss_sndtok;
8465 Ssh_gss_name gss_srv_name;
8466 Ssh_gss_stat gss_stat;
8469 crState(do_ssh2_authconn_state);
8473 /* Register as a handler for all the messages this coroutine handles. */
8474 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
8475 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
8476 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
8477 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
8478 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
8479 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
8480 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
8481 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
8482 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
8483 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
8484 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
8485 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
8486 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
8487 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
8488 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
8489 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
8490 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
8491 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
8492 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
8493 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
8495 s->done_service_req = FALSE;
8496 s->we_are_in = s->userauth_success = FALSE;
8497 s->agent_response = NULL;
8499 s->tried_gssapi = FALSE;
8502 if (!ssh->bare_connection) {
8503 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
8505 * Request userauth protocol, and await a response to it.
8507 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8508 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
8509 ssh2_pkt_send(ssh, s->pktout);
8510 crWaitUntilV(pktin);
8511 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
8512 s->done_service_req = TRUE;
8514 if (!s->done_service_req) {
8516 * Request connection protocol directly, without authentication.
8518 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8519 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8520 ssh2_pkt_send(ssh, s->pktout);
8521 crWaitUntilV(pktin);
8522 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
8523 s->we_are_in = TRUE; /* no auth required */
8525 bombout(("Server refused service request"));
8530 s->we_are_in = TRUE;
8533 /* Arrange to be able to deal with any BANNERs that come in.
8534 * (We do this now as packets may come in during the next bit.) */
8535 bufchain_init(&ssh->banner);
8536 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
8537 ssh2_msg_userauth_banner;
8540 * Misc one-time setup for authentication.
8542 s->publickey_blob = NULL;
8543 if (!s->we_are_in) {
8546 * Load the public half of any configured public key file
8549 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
8550 if (!filename_is_null(s->keyfile)) {
8552 logeventf(ssh, "Reading private key file \"%.150s\"",
8553 filename_to_str(s->keyfile));
8554 keytype = key_type(s->keyfile);
8555 if (keytype == SSH_KEYTYPE_SSH2) {
8558 ssh2_userkey_loadpub(s->keyfile,
8559 &s->publickey_algorithm,
8560 &s->publickey_bloblen,
8561 &s->publickey_comment, &error);
8562 if (s->publickey_blob) {
8563 s->publickey_encrypted =
8564 ssh2_userkey_encrypted(s->keyfile, NULL);
8567 logeventf(ssh, "Unable to load private key (%s)",
8569 msgbuf = dupprintf("Unable to load private key file "
8570 "\"%.150s\" (%s)\r\n",
8571 filename_to_str(s->keyfile),
8573 c_write_str(ssh, msgbuf);
8578 logeventf(ssh, "Unable to use this key file (%s)",
8579 key_type_to_str(keytype));
8580 msgbuf = dupprintf("Unable to use key file \"%.150s\""
8582 filename_to_str(s->keyfile),
8583 key_type_to_str(keytype));
8584 c_write_str(ssh, msgbuf);
8586 s->publickey_blob = NULL;
8591 * Find out about any keys Pageant has (but if there's a
8592 * public key configured, filter out all others).
8595 s->agent_response = NULL;
8596 s->pkblob_in_agent = NULL;
8597 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
8601 logevent("Pageant is running. Requesting keys.");
8603 /* Request the keys held by the agent. */
8604 PUT_32BIT(s->agent_request, 1);
8605 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
8606 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
8607 ssh_agent_callback, ssh)) {
8611 bombout(("Unexpected data from server while"
8612 " waiting for agent response"));
8615 } while (pktin || inlen > 0);
8616 r = ssh->agent_response;
8617 s->agent_responselen = ssh->agent_response_len;
8619 s->agent_response = (unsigned char *) r;
8620 if (s->agent_response && s->agent_responselen >= 5 &&
8621 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
8624 p = s->agent_response + 5;
8625 s->nkeys = toint(GET_32BIT(p));
8628 * Vet the Pageant response to ensure that the key
8629 * count and blob lengths make sense.
8632 logeventf(ssh, "Pageant response contained a negative"
8633 " key count %d", s->nkeys);
8635 goto done_agent_query;
8637 unsigned char *q = p + 4;
8638 int lenleft = s->agent_responselen - 5 - 4;
8640 for (keyi = 0; keyi < s->nkeys; keyi++) {
8641 int bloblen, commentlen;
8643 logeventf(ssh, "Pageant response was truncated");
8645 goto done_agent_query;
8647 bloblen = toint(GET_32BIT(q));
8648 if (bloblen < 0 || bloblen > lenleft) {
8649 logeventf(ssh, "Pageant response was truncated");
8651 goto done_agent_query;
8653 lenleft -= 4 + bloblen;
8655 commentlen = toint(GET_32BIT(q));
8656 if (commentlen < 0 || commentlen > lenleft) {
8657 logeventf(ssh, "Pageant response was truncated");
8659 goto done_agent_query;
8661 lenleft -= 4 + commentlen;
8662 q += 4 + commentlen;
8667 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
8668 if (s->publickey_blob) {
8669 /* See if configured key is in agent. */
8670 for (keyi = 0; keyi < s->nkeys; keyi++) {
8671 s->pklen = toint(GET_32BIT(p));
8672 if (s->pklen == s->publickey_bloblen &&
8673 !memcmp(p+4, s->publickey_blob,
8674 s->publickey_bloblen)) {
8675 logeventf(ssh, "Pageant key #%d matches "
8676 "configured key file", keyi);
8678 s->pkblob_in_agent = p;
8682 p += toint(GET_32BIT(p)) + 4; /* comment */
8684 if (!s->pkblob_in_agent) {
8685 logevent("Configured key file not in Pageant");
8690 logevent("Failed to get reply from Pageant");
8698 * We repeat this whole loop, including the username prompt,
8699 * until we manage a successful authentication. If the user
8700 * types the wrong _password_, they can be sent back to the
8701 * beginning to try another username, if this is configured on.
8702 * (If they specify a username in the config, they are never
8703 * asked, even if they do give a wrong password.)
8705 * I think this best serves the needs of
8707 * - the people who have no configuration, no keys, and just
8708 * want to try repeated (username,password) pairs until they
8709 * type both correctly
8711 * - people who have keys and configuration but occasionally
8712 * need to fall back to passwords
8714 * - people with a key held in Pageant, who might not have
8715 * logged in to a particular machine before; so they want to
8716 * type a username, and then _either_ their key will be
8717 * accepted, _or_ they will type a password. If they mistype
8718 * the username they will want to be able to get back and
8721 s->got_username = FALSE;
8722 while (!s->we_are_in) {
8726 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
8728 * We got a username last time round this loop, and
8729 * with change_username turned off we don't try to get
8732 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
8733 int ret; /* need not be kept over crReturn */
8734 s->cur_prompt = new_prompts(ssh->frontend);
8735 s->cur_prompt->to_server = TRUE;
8736 s->cur_prompt->name = dupstr("SSH login name");
8737 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
8738 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8741 crWaitUntilV(!pktin);
8742 ret = get_userpass_input(s->cur_prompt, in, inlen);
8747 * get_userpass_input() failed to get a username.
8750 free_prompts(s->cur_prompt);
8751 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
8754 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
8755 free_prompts(s->cur_prompt);
8758 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
8759 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
8760 c_write_str(ssh, stuff);
8764 s->got_username = TRUE;
8767 * Send an authentication request using method "none": (a)
8768 * just in case it succeeds, and (b) so that we know what
8769 * authentication methods we can usefully try next.
8771 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
8773 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8774 ssh2_pkt_addstring(s->pktout, ssh->username);
8775 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
8776 ssh2_pkt_addstring(s->pktout, "none"); /* method */
8777 ssh2_pkt_send(ssh, s->pktout);
8778 s->type = AUTH_TYPE_NONE;
8780 s->we_are_in = FALSE;
8782 s->tried_pubkey_config = FALSE;
8783 s->kbd_inter_refused = FALSE;
8785 /* Reset agent request state. */
8786 s->done_agent = FALSE;
8787 if (s->agent_response) {
8788 if (s->pkblob_in_agent) {
8789 s->agentp = s->pkblob_in_agent;
8791 s->agentp = s->agent_response + 5 + 4;
8797 char *methods = NULL;
8801 * Wait for the result of the last authentication request.
8804 crWaitUntilV(pktin);
8806 * Now is a convenient point to spew any banner material
8807 * that we've accumulated. (This should ensure that when
8808 * we exit the auth loop, we haven't any left to deal
8812 int size = bufchain_size(&ssh->banner);
8814 * Don't show the banner if we're operating in
8815 * non-verbose non-interactive mode. (It's probably
8816 * a script, which means nobody will read the
8817 * banner _anyway_, and moreover the printing of
8818 * the banner will screw up processing on the
8819 * output of (say) plink.)
8821 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
8822 char *banner = snewn(size, char);
8823 bufchain_fetch(&ssh->banner, banner, size);
8824 c_write_untrusted(ssh, banner, size);
8827 bufchain_clear(&ssh->banner);
8829 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
8830 logevent("Access granted");
8831 s->we_are_in = s->userauth_success = TRUE;
8835 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
8836 bombout(("Strange packet received during authentication: "
8837 "type %d", pktin->type));
8844 * OK, we're now sitting on a USERAUTH_FAILURE message, so
8845 * we can look at the string in it and know what we can
8846 * helpfully try next.
8848 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
8849 ssh_pkt_getstring(pktin, &methods, &methlen);
8850 if (!ssh2_pkt_getbool(pktin)) {
8852 * We have received an unequivocal Access
8853 * Denied. This can translate to a variety of
8854 * messages, or no message at all.
8856 * For forms of authentication which are attempted
8857 * implicitly, by which I mean without printing
8858 * anything in the window indicating that we're
8859 * trying them, we should never print 'Access
8862 * If we do print a message saying that we're
8863 * attempting some kind of authentication, it's OK
8864 * to print a followup message saying it failed -
8865 * but the message may sometimes be more specific
8866 * than simply 'Access denied'.
8868 * Additionally, if we'd just tried password
8869 * authentication, we should break out of this
8870 * whole loop so as to go back to the username
8871 * prompt (iff we're configured to allow
8872 * username change attempts).
8874 if (s->type == AUTH_TYPE_NONE) {
8876 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
8877 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
8878 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
8879 c_write_str(ssh, "Server refused our key\r\n");
8880 logevent("Server refused our key");
8881 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
8882 /* This _shouldn't_ happen except by a
8883 * protocol bug causing client and server to
8884 * disagree on what is a correct signature. */
8885 c_write_str(ssh, "Server refused public-key signature"
8886 " despite accepting key!\r\n");
8887 logevent("Server refused public-key signature"
8888 " despite accepting key!");
8889 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
8890 /* quiet, so no c_write */
8891 logevent("Server refused keyboard-interactive authentication");
8892 } else if (s->type==AUTH_TYPE_GSSAPI) {
8893 /* always quiet, so no c_write */
8894 /* also, the code down in the GSSAPI block has
8895 * already logged this in the Event Log */
8896 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
8897 logevent("Keyboard-interactive authentication failed");
8898 c_write_str(ssh, "Access denied\r\n");
8900 assert(s->type == AUTH_TYPE_PASSWORD);
8901 logevent("Password authentication failed");
8902 c_write_str(ssh, "Access denied\r\n");
8904 if (conf_get_int(ssh->conf, CONF_change_username)) {
8905 /* XXX perhaps we should allow
8906 * keyboard-interactive to do this too? */
8907 s->we_are_in = FALSE;
8912 c_write_str(ssh, "Further authentication required\r\n");
8913 logevent("Further authentication required");
8917 in_commasep_string("publickey", methods, methlen);
8919 in_commasep_string("password", methods, methlen);
8920 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
8921 in_commasep_string("keyboard-interactive", methods, methlen);
8924 ssh->gsslibs = ssh_gss_setup(ssh->conf);
8925 s->can_gssapi = conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
8926 in_commasep_string("gssapi-with-mic", methods, methlen) &&
8927 ssh->gsslibs->nlibraries > 0;
8931 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
8933 if (s->can_pubkey && !s->done_agent && s->nkeys) {
8936 * Attempt public-key authentication using a key from Pageant.
8939 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
8941 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
8943 /* Unpack key from agent response */
8944 s->pklen = toint(GET_32BIT(s->agentp));
8946 s->pkblob = (char *)s->agentp;
8947 s->agentp += s->pklen;
8948 s->alglen = toint(GET_32BIT(s->pkblob));
8949 s->alg = s->pkblob + 4;
8950 s->commentlen = toint(GET_32BIT(s->agentp));
8952 s->commentp = (char *)s->agentp;
8953 s->agentp += s->commentlen;
8954 /* s->agentp now points at next key, if any */
8956 /* See if server will accept it */
8957 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8958 ssh2_pkt_addstring(s->pktout, ssh->username);
8959 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8960 /* service requested */
8961 ssh2_pkt_addstring(s->pktout, "publickey");
8963 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
8964 ssh2_pkt_addstring_start(s->pktout);
8965 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
8966 ssh2_pkt_addstring_start(s->pktout);
8967 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
8968 ssh2_pkt_send(ssh, s->pktout);
8969 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
8971 crWaitUntilV(pktin);
8972 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
8974 /* Offer of key refused. */
8981 if (flags & FLAG_VERBOSE) {
8982 c_write_str(ssh, "Authenticating with "
8984 c_write(ssh, s->commentp, s->commentlen);
8985 c_write_str(ssh, "\" from agent\r\n");
8989 * Server is willing to accept the key.
8990 * Construct a SIGN_REQUEST.
8992 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8993 ssh2_pkt_addstring(s->pktout, ssh->username);
8994 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8995 /* service requested */
8996 ssh2_pkt_addstring(s->pktout, "publickey");
8998 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
8999 ssh2_pkt_addstring_start(s->pktout);
9000 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9001 ssh2_pkt_addstring_start(s->pktout);
9002 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9004 /* Ask agent for signature. */
9005 s->siglen = s->pktout->length - 5 + 4 +
9006 ssh->v2_session_id_len;
9007 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9009 s->len = 1; /* message type */
9010 s->len += 4 + s->pklen; /* key blob */
9011 s->len += 4 + s->siglen; /* data to sign */
9012 s->len += 4; /* flags */
9013 s->agentreq = snewn(4 + s->len, char);
9014 PUT_32BIT(s->agentreq, s->len);
9015 s->q = s->agentreq + 4;
9016 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
9017 PUT_32BIT(s->q, s->pklen);
9019 memcpy(s->q, s->pkblob, s->pklen);
9021 PUT_32BIT(s->q, s->siglen);
9023 /* Now the data to be signed... */
9024 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9025 PUT_32BIT(s->q, ssh->v2_session_id_len);
9028 memcpy(s->q, ssh->v2_session_id,
9029 ssh->v2_session_id_len);
9030 s->q += ssh->v2_session_id_len;
9031 memcpy(s->q, s->pktout->data + 5,
9032 s->pktout->length - 5);
9033 s->q += s->pktout->length - 5;
9034 /* And finally the (zero) flags word. */
9036 if (!agent_query(s->agentreq, s->len + 4,
9038 ssh_agent_callback, ssh)) {
9042 bombout(("Unexpected data from server"
9043 " while waiting for agent"
9047 } while (pktin || inlen > 0);
9048 vret = ssh->agent_response;
9049 s->retlen = ssh->agent_response_len;
9054 if (s->retlen >= 9 &&
9055 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
9056 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
9057 logevent("Sending Pageant's response");
9058 ssh2_add_sigblob(ssh, s->pktout,
9059 s->pkblob, s->pklen,
9061 GET_32BIT(s->ret + 5));
9062 ssh2_pkt_send(ssh, s->pktout);
9063 s->type = AUTH_TYPE_PUBLICKEY;
9065 /* FIXME: less drastic response */
9066 bombout(("Pageant failed to answer challenge"));
9072 /* Do we have any keys left to try? */
9073 if (s->pkblob_in_agent) {
9074 s->done_agent = TRUE;
9075 s->tried_pubkey_config = TRUE;
9078 if (s->keyi >= s->nkeys)
9079 s->done_agent = TRUE;
9082 } else if (s->can_pubkey && s->publickey_blob &&
9083 !s->tried_pubkey_config) {
9085 struct ssh2_userkey *key; /* not live over crReturn */
9086 char *passphrase; /* not live over crReturn */
9088 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9090 s->tried_pubkey_config = TRUE;
9093 * Try the public key supplied in the configuration.
9095 * First, offer the public blob to see if the server is
9096 * willing to accept it.
9098 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9099 ssh2_pkt_addstring(s->pktout, ssh->username);
9100 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9101 /* service requested */
9102 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
9103 ssh2_pkt_addbool(s->pktout, FALSE);
9104 /* no signature included */
9105 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
9106 ssh2_pkt_addstring_start(s->pktout);
9107 ssh2_pkt_addstring_data(s->pktout,
9108 (char *)s->publickey_blob,
9109 s->publickey_bloblen);
9110 ssh2_pkt_send(ssh, s->pktout);
9111 logevent("Offered public key");
9113 crWaitUntilV(pktin);
9114 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9115 /* Key refused. Give up. */
9116 s->gotit = TRUE; /* reconsider message next loop */
9117 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
9118 continue; /* process this new message */
9120 logevent("Offer of public key accepted");
9123 * Actually attempt a serious authentication using
9126 if (flags & FLAG_VERBOSE) {
9127 c_write_str(ssh, "Authenticating with public key \"");
9128 c_write_str(ssh, s->publickey_comment);
9129 c_write_str(ssh, "\"\r\n");
9133 const char *error; /* not live over crReturn */
9134 if (s->publickey_encrypted) {
9136 * Get a passphrase from the user.
9138 int ret; /* need not be kept over crReturn */
9139 s->cur_prompt = new_prompts(ssh->frontend);
9140 s->cur_prompt->to_server = FALSE;
9141 s->cur_prompt->name = dupstr("SSH key passphrase");
9142 add_prompt(s->cur_prompt,
9143 dupprintf("Passphrase for key \"%.100s\": ",
9144 s->publickey_comment),
9146 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9149 crWaitUntilV(!pktin);
9150 ret = get_userpass_input(s->cur_prompt,
9155 /* Failed to get a passphrase. Terminate. */
9156 free_prompts(s->cur_prompt);
9157 ssh_disconnect(ssh, NULL,
9158 "Unable to authenticate",
9159 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9164 dupstr(s->cur_prompt->prompts[0]->result);
9165 free_prompts(s->cur_prompt);
9167 passphrase = NULL; /* no passphrase needed */
9171 * Try decrypting the key.
9173 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9174 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
9176 /* burn the evidence */
9177 smemclr(passphrase, strlen(passphrase));
9180 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
9182 (key == SSH2_WRONG_PASSPHRASE)) {
9183 c_write_str(ssh, "Wrong passphrase\r\n");
9185 /* and loop again */
9187 c_write_str(ssh, "Unable to load private key (");
9188 c_write_str(ssh, error);
9189 c_write_str(ssh, ")\r\n");
9191 break; /* try something else */
9197 unsigned char *pkblob, *sigblob, *sigdata;
9198 int pkblob_len, sigblob_len, sigdata_len;
9202 * We have loaded the private key and the server
9203 * has announced that it's willing to accept it.
9204 * Hallelujah. Generate a signature and send it.
9206 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9207 ssh2_pkt_addstring(s->pktout, ssh->username);
9208 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9209 /* service requested */
9210 ssh2_pkt_addstring(s->pktout, "publickey");
9212 ssh2_pkt_addbool(s->pktout, TRUE);
9213 /* signature follows */
9214 ssh2_pkt_addstring(s->pktout, key->alg->name);
9215 pkblob = key->alg->public_blob(key->data,
9217 ssh2_pkt_addstring_start(s->pktout);
9218 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
9222 * The data to be signed is:
9226 * followed by everything so far placed in the
9229 sigdata_len = s->pktout->length - 5 + 4 +
9230 ssh->v2_session_id_len;
9231 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9233 sigdata = snewn(sigdata_len, unsigned char);
9235 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9236 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
9239 memcpy(sigdata+p, ssh->v2_session_id,
9240 ssh->v2_session_id_len);
9241 p += ssh->v2_session_id_len;
9242 memcpy(sigdata+p, s->pktout->data + 5,
9243 s->pktout->length - 5);
9244 p += s->pktout->length - 5;
9245 assert(p == sigdata_len);
9246 sigblob = key->alg->sign(key->data, (char *)sigdata,
9247 sigdata_len, &sigblob_len);
9248 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
9249 sigblob, sigblob_len);
9254 ssh2_pkt_send(ssh, s->pktout);
9255 logevent("Sent public key signature");
9256 s->type = AUTH_TYPE_PUBLICKEY;
9257 key->alg->freekey(key->data);
9261 } else if (s->can_gssapi && !s->tried_gssapi) {
9263 /* GSSAPI Authentication */
9268 s->type = AUTH_TYPE_GSSAPI;
9269 s->tried_gssapi = TRUE;
9271 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
9274 * Pick the highest GSS library on the preference
9280 for (i = 0; i < ngsslibs; i++) {
9281 int want_id = conf_get_int_int(ssh->conf,
9282 CONF_ssh_gsslist, i);
9283 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
9284 if (ssh->gsslibs->libraries[j].id == want_id) {
9285 s->gsslib = &ssh->gsslibs->libraries[j];
9286 goto got_gsslib; /* double break */
9291 * We always expect to have found something in
9292 * the above loop: we only came here if there
9293 * was at least one viable GSS library, and the
9294 * preference list should always mention
9295 * everything and only change the order.
9300 if (s->gsslib->gsslogmsg)
9301 logevent(s->gsslib->gsslogmsg);
9303 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
9304 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9305 ssh2_pkt_addstring(s->pktout, ssh->username);
9306 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9307 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
9308 logevent("Attempting GSSAPI authentication");
9310 /* add mechanism info */
9311 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
9313 /* number of GSSAPI mechanisms */
9314 ssh2_pkt_adduint32(s->pktout,1);
9316 /* length of OID + 2 */
9317 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
9318 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
9321 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
9323 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
9325 ssh2_pkt_send(ssh, s->pktout);
9326 crWaitUntilV(pktin);
9327 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
9328 logevent("GSSAPI authentication request refused");
9332 /* check returned packet ... */
9334 ssh_pkt_getstring(pktin, &data, &len);
9335 s->gss_rcvtok.value = data;
9336 s->gss_rcvtok.length = len;
9337 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
9338 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
9339 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
9340 memcmp((char *)s->gss_rcvtok.value + 2,
9341 s->gss_buf.value,s->gss_buf.length) ) {
9342 logevent("GSSAPI authentication - wrong response from server");
9346 /* now start running */
9347 s->gss_stat = s->gsslib->import_name(s->gsslib,
9350 if (s->gss_stat != SSH_GSS_OK) {
9351 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
9352 logevent("GSSAPI import name failed - Bad service name");
9354 logevent("GSSAPI import name failed");
9358 /* fetch TGT into GSS engine */
9359 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
9361 if (s->gss_stat != SSH_GSS_OK) {
9362 logevent("GSSAPI authentication failed to get credentials");
9363 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9367 /* initial tokens are empty */
9368 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
9369 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
9371 /* now enter the loop */
9373 s->gss_stat = s->gsslib->init_sec_context
9377 conf_get_int(ssh->conf, CONF_gssapifwd),
9381 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
9382 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
9383 logevent("GSSAPI authentication initialisation failed");
9385 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
9386 &s->gss_buf) == SSH_GSS_OK) {
9387 logevent(s->gss_buf.value);
9388 sfree(s->gss_buf.value);
9393 logevent("GSSAPI authentication initialised");
9395 /* Client and server now exchange tokens until GSSAPI
9396 * no longer says CONTINUE_NEEDED */
9398 if (s->gss_sndtok.length != 0) {
9399 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
9400 ssh_pkt_addstring_start(s->pktout);
9401 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
9402 ssh2_pkt_send(ssh, s->pktout);
9403 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
9406 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
9407 crWaitUntilV(pktin);
9408 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
9409 logevent("GSSAPI authentication - bad server response");
9410 s->gss_stat = SSH_GSS_FAILURE;
9413 ssh_pkt_getstring(pktin, &data, &len);
9414 s->gss_rcvtok.value = data;
9415 s->gss_rcvtok.length = len;
9417 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
9419 if (s->gss_stat != SSH_GSS_OK) {
9420 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9421 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9424 logevent("GSSAPI authentication loop finished OK");
9426 /* Now send the MIC */
9428 s->pktout = ssh2_pkt_init(0);
9429 micoffset = s->pktout->length;
9430 ssh_pkt_addstring_start(s->pktout);
9431 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
9432 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
9433 ssh_pkt_addstring(s->pktout, ssh->username);
9434 ssh_pkt_addstring(s->pktout, "ssh-connection");
9435 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
9437 s->gss_buf.value = (char *)s->pktout->data + micoffset;
9438 s->gss_buf.length = s->pktout->length - micoffset;
9440 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
9441 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
9442 ssh_pkt_addstring_start(s->pktout);
9443 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
9444 ssh2_pkt_send(ssh, s->pktout);
9445 s->gsslib->free_mic(s->gsslib, &mic);
9449 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9450 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9453 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
9456 * Keyboard-interactive authentication.
9459 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
9461 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
9463 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9464 ssh2_pkt_addstring(s->pktout, ssh->username);
9465 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9466 /* service requested */
9467 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
9469 ssh2_pkt_addstring(s->pktout, ""); /* lang */
9470 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
9471 ssh2_pkt_send(ssh, s->pktout);
9473 logevent("Attempting keyboard-interactive authentication");
9475 crWaitUntilV(pktin);
9476 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
9477 /* Server is not willing to do keyboard-interactive
9478 * at all (or, bizarrely but legally, accepts the
9479 * user without actually issuing any prompts).
9480 * Give up on it entirely. */
9482 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
9483 s->kbd_inter_refused = TRUE; /* don't try it again */
9488 * Loop while the server continues to send INFO_REQUESTs.
9490 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
9492 char *name, *inst, *lang;
9493 int name_len, inst_len, lang_len;
9497 * We've got a fresh USERAUTH_INFO_REQUEST.
9498 * Get the preamble and start building a prompt.
9500 ssh_pkt_getstring(pktin, &name, &name_len);
9501 ssh_pkt_getstring(pktin, &inst, &inst_len);
9502 ssh_pkt_getstring(pktin, &lang, &lang_len);
9503 s->cur_prompt = new_prompts(ssh->frontend);
9504 s->cur_prompt->to_server = TRUE;
9507 * Get any prompt(s) from the packet.
9509 s->num_prompts = ssh_pkt_getuint32(pktin);
9510 for (i = 0; i < s->num_prompts; i++) {
9514 static char noprompt[] =
9515 "<server failed to send prompt>: ";
9517 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9518 echo = ssh2_pkt_getbool(pktin);
9521 prompt_len = lenof(noprompt)-1;
9523 add_prompt(s->cur_prompt,
9524 dupprintf("%.*s", prompt_len, prompt),
9529 /* FIXME: better prefix to distinguish from
9531 s->cur_prompt->name =
9532 dupprintf("SSH server: %.*s", name_len, name);
9533 s->cur_prompt->name_reqd = TRUE;
9535 s->cur_prompt->name =
9536 dupstr("SSH server authentication");
9537 s->cur_prompt->name_reqd = FALSE;
9539 /* We add a prefix to try to make it clear that a prompt
9540 * has come from the server.
9541 * FIXME: ugly to print "Using..." in prompt _every_
9542 * time round. Can this be done more subtly? */
9543 /* Special case: for reasons best known to themselves,
9544 * some servers send k-i requests with no prompts and
9545 * nothing to display. Keep quiet in this case. */
9546 if (s->num_prompts || name_len || inst_len) {
9547 s->cur_prompt->instruction =
9548 dupprintf("Using keyboard-interactive authentication.%s%.*s",
9549 inst_len ? "\n" : "", inst_len, inst);
9550 s->cur_prompt->instr_reqd = TRUE;
9552 s->cur_prompt->instr_reqd = FALSE;
9556 * Display any instructions, and get the user's
9560 int ret; /* not live over crReturn */
9561 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9564 crWaitUntilV(!pktin);
9565 ret = get_userpass_input(s->cur_prompt, in, inlen);
9570 * Failed to get responses. Terminate.
9572 free_prompts(s->cur_prompt);
9573 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9574 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9581 * Send the response(s) to the server.
9583 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
9584 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
9585 for (i=0; i < s->num_prompts; i++) {
9586 ssh2_pkt_addstring(s->pktout,
9587 s->cur_prompt->prompts[i]->result);
9589 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9592 * Free the prompts structure from this iteration.
9593 * If there's another, a new one will be allocated
9594 * when we return to the top of this while loop.
9596 free_prompts(s->cur_prompt);
9599 * Get the next packet in case it's another
9602 crWaitUntilV(pktin);
9607 * We should have SUCCESS or FAILURE now.
9611 } else if (s->can_passwd) {
9614 * Plain old password authentication.
9616 int ret; /* not live over crReturn */
9617 int changereq_first_time; /* not live over crReturn */
9619 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
9621 s->cur_prompt = new_prompts(ssh->frontend);
9622 s->cur_prompt->to_server = TRUE;
9623 s->cur_prompt->name = dupstr("SSH password");
9624 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
9629 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9632 crWaitUntilV(!pktin);
9633 ret = get_userpass_input(s->cur_prompt, in, inlen);
9638 * Failed to get responses. Terminate.
9640 free_prompts(s->cur_prompt);
9641 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9642 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9647 * Squirrel away the password. (We may need it later if
9648 * asked to change it.)
9650 s->password = dupstr(s->cur_prompt->prompts[0]->result);
9651 free_prompts(s->cur_prompt);
9654 * Send the password packet.
9656 * We pad out the password packet to 256 bytes to make
9657 * it harder for an attacker to find the length of the
9660 * Anyone using a password longer than 256 bytes
9661 * probably doesn't have much to worry about from
9662 * people who find out how long their password is!
9664 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9665 ssh2_pkt_addstring(s->pktout, ssh->username);
9666 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9667 /* service requested */
9668 ssh2_pkt_addstring(s->pktout, "password");
9669 ssh2_pkt_addbool(s->pktout, FALSE);
9670 ssh2_pkt_addstring(s->pktout, s->password);
9671 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9672 logevent("Sent password");
9673 s->type = AUTH_TYPE_PASSWORD;
9676 * Wait for next packet, in case it's a password change
9679 crWaitUntilV(pktin);
9680 changereq_first_time = TRUE;
9682 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
9685 * We're being asked for a new password
9686 * (perhaps not for the first time).
9687 * Loop until the server accepts it.
9690 int got_new = FALSE; /* not live over crReturn */
9691 char *prompt; /* not live over crReturn */
9692 int prompt_len; /* not live over crReturn */
9696 if (changereq_first_time)
9697 msg = "Server requested password change";
9699 msg = "Server rejected new password";
9701 c_write_str(ssh, msg);
9702 c_write_str(ssh, "\r\n");
9705 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9707 s->cur_prompt = new_prompts(ssh->frontend);
9708 s->cur_prompt->to_server = TRUE;
9709 s->cur_prompt->name = dupstr("New SSH password");
9710 s->cur_prompt->instruction =
9711 dupprintf("%.*s", prompt_len, prompt);
9712 s->cur_prompt->instr_reqd = TRUE;
9714 * There's no explicit requirement in the protocol
9715 * for the "old" passwords in the original and
9716 * password-change messages to be the same, and
9717 * apparently some Cisco kit supports password change
9718 * by the user entering a blank password originally
9719 * and the real password subsequently, so,
9720 * reluctantly, we prompt for the old password again.
9722 * (On the other hand, some servers don't even bother
9723 * to check this field.)
9725 add_prompt(s->cur_prompt,
9726 dupstr("Current password (blank for previously entered password): "),
9728 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
9730 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
9734 * Loop until the user manages to enter the same
9739 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9742 crWaitUntilV(!pktin);
9743 ret = get_userpass_input(s->cur_prompt, in, inlen);
9748 * Failed to get responses. Terminate.
9750 /* burn the evidence */
9751 free_prompts(s->cur_prompt);
9752 smemclr(s->password, strlen(s->password));
9754 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9755 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9761 * If the user specified a new original password
9762 * (IYSWIM), overwrite any previously specified
9764 * (A side effect is that the user doesn't have to
9765 * re-enter it if they louse up the new password.)
9767 if (s->cur_prompt->prompts[0]->result[0]) {
9768 smemclr(s->password, strlen(s->password));
9769 /* burn the evidence */
9772 dupstr(s->cur_prompt->prompts[0]->result);
9776 * Check the two new passwords match.
9778 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
9779 s->cur_prompt->prompts[2]->result)
9782 /* They don't. Silly user. */
9783 c_write_str(ssh, "Passwords do not match\r\n");
9788 * Send the new password (along with the old one).
9789 * (see above for padding rationale)
9791 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9792 ssh2_pkt_addstring(s->pktout, ssh->username);
9793 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9794 /* service requested */
9795 ssh2_pkt_addstring(s->pktout, "password");
9796 ssh2_pkt_addbool(s->pktout, TRUE);
9797 ssh2_pkt_addstring(s->pktout, s->password);
9798 ssh2_pkt_addstring(s->pktout,
9799 s->cur_prompt->prompts[1]->result);
9800 free_prompts(s->cur_prompt);
9801 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9802 logevent("Sent new password");
9805 * Now see what the server has to say about it.
9806 * (If it's CHANGEREQ again, it's not happy with the
9809 crWaitUntilV(pktin);
9810 changereq_first_time = FALSE;
9815 * We need to reexamine the current pktin at the top
9816 * of the loop. Either:
9817 * - we weren't asked to change password at all, in
9818 * which case it's a SUCCESS or FAILURE with the
9820 * - we sent a new password, and the server was
9821 * either OK with it (SUCCESS or FAILURE w/partial
9822 * success) or unhappy with the _old_ password
9823 * (FAILURE w/o partial success)
9824 * In any of these cases, we go back to the top of
9825 * the loop and start again.
9830 * We don't need the old password any more, in any
9831 * case. Burn the evidence.
9833 smemclr(s->password, strlen(s->password));
9837 char *str = dupprintf("No supported authentication methods available"
9838 " (server sent: %.*s)",
9841 ssh_disconnect(ssh, str,
9842 "No supported authentication methods available",
9843 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
9853 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
9855 /* Clear up various bits and pieces from authentication. */
9856 if (s->publickey_blob) {
9857 sfree(s->publickey_blob);
9858 sfree(s->publickey_comment);
9860 if (s->agent_response)
9861 sfree(s->agent_response);
9863 if (s->userauth_success && !ssh->bare_connection) {
9865 * We've just received USERAUTH_SUCCESS, and we haven't sent any
9866 * packets since. Signal the transport layer to consider enacting
9867 * delayed compression.
9869 * (Relying on we_are_in is not sufficient, as
9870 * draft-miller-secsh-compression-delayed is quite clear that it
9871 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
9872 * become set for other reasons.)
9874 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
9877 ssh->channels = newtree234(ssh_channelcmp);
9880 * Set up handlers for some connection protocol messages, so we
9881 * don't have to handle them repeatedly in this coroutine.
9883 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
9884 ssh2_msg_channel_window_adjust;
9885 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
9886 ssh2_msg_global_request;
9889 * Create the main session channel.
9891 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
9892 ssh->mainchan = NULL;
9894 ssh->mainchan = snew(struct ssh_channel);
9895 ssh->mainchan->ssh = ssh;
9896 ssh2_channel_init(ssh->mainchan);
9898 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
9900 * Just start a direct-tcpip channel and use it as the main
9903 ssh_send_port_open(ssh->mainchan,
9904 conf_get_str(ssh->conf, CONF_ssh_nc_host),
9905 conf_get_int(ssh->conf, CONF_ssh_nc_port),
9909 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
9910 logevent("Opening session as main channel");
9911 ssh2_pkt_send(ssh, s->pktout);
9912 ssh->ncmode = FALSE;
9914 crWaitUntilV(pktin);
9915 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
9916 bombout(("Server refused to open channel"));
9918 /* FIXME: error data comes back in FAILURE packet */
9920 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
9921 bombout(("Server's channel confirmation cited wrong channel"));
9924 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
9925 ssh->mainchan->halfopen = FALSE;
9926 ssh->mainchan->type = CHAN_MAINSESSION;
9927 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
9928 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
9929 add234(ssh->channels, ssh->mainchan);
9930 update_specials_menu(ssh->frontend);
9931 logevent("Opened main channel");
9935 * Now we have a channel, make dispatch table entries for
9936 * general channel-based messages.
9938 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
9939 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
9940 ssh2_msg_channel_data;
9941 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
9942 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
9943 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
9944 ssh2_msg_channel_open_confirmation;
9945 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
9946 ssh2_msg_channel_open_failure;
9947 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
9948 ssh2_msg_channel_request;
9949 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
9950 ssh2_msg_channel_open;
9951 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
9952 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
9955 * Now the connection protocol is properly up and running, with
9956 * all those dispatch table entries, so it's safe to let
9957 * downstreams start trying to open extra channels through us.
9960 share_activate(ssh->connshare, ssh->v_s);
9962 if (ssh->mainchan && ssh_is_simple(ssh)) {
9964 * This message indicates to the server that we promise
9965 * not to try to run any other channel in parallel with
9966 * this one, so it's safe for it to advertise a very large
9967 * window and leave the flow control to TCP.
9969 s->pktout = ssh2_chanreq_init(ssh->mainchan,
9970 "simple@putty.projects.tartarus.org",
9972 ssh2_pkt_send(ssh, s->pktout);
9976 * Enable port forwardings.
9978 ssh_setup_portfwd(ssh, ssh->conf);
9980 if (ssh->mainchan && !ssh->ncmode) {
9982 * Send the CHANNEL_REQUESTS for the main session channel.
9983 * Each one is handled by its own little asynchronous
9987 /* Potentially enable X11 forwarding. */
9988 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
9990 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
9992 if (!ssh->x11disp) {
9993 /* FIXME: return an error message from x11_setup_display */
9994 logevent("X11 forwarding not enabled: unable to"
9995 " initialise X display");
9997 ssh->x11auth = x11_invent_fake_auth
9998 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
9999 ssh->x11auth->disp = ssh->x11disp;
10001 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
10005 /* Potentially enable agent forwarding. */
10006 if (ssh_agent_forwarding_permitted(ssh))
10007 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
10009 /* Now allocate a pty for the session. */
10010 if (!conf_get_int(ssh->conf, CONF_nopty))
10011 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
10013 /* Send environment variables. */
10014 ssh2_setup_env(ssh->mainchan, NULL, NULL);
10017 * Start a shell or a remote command. We may have to attempt
10018 * this twice if the config data has provided a second choice
10025 if (ssh->fallback_cmd) {
10026 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
10027 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
10029 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
10030 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
10034 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
10035 ssh2_response_authconn, NULL);
10036 ssh2_pkt_addstring(s->pktout, cmd);
10038 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
10039 ssh2_response_authconn, NULL);
10040 ssh2_pkt_addstring(s->pktout, cmd);
10042 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
10043 ssh2_response_authconn, NULL);
10045 ssh2_pkt_send(ssh, s->pktout);
10047 crWaitUntilV(pktin);
10049 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
10050 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
10051 bombout(("Unexpected response to shell/command request:"
10052 " packet type %d", pktin->type));
10056 * We failed to start the command. If this is the
10057 * fallback command, we really are finished; if it's
10058 * not, and if the fallback command exists, try falling
10059 * back to it before complaining.
10061 if (!ssh->fallback_cmd &&
10062 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
10063 logevent("Primary command failed; attempting fallback");
10064 ssh->fallback_cmd = TRUE;
10067 bombout(("Server refused to start a shell/command"));
10070 logevent("Started a shell/command");
10075 ssh->editing = ssh->echoing = TRUE;
10078 ssh->state = SSH_STATE_SESSION;
10079 if (ssh->size_needed)
10080 ssh_size(ssh, ssh->term_width, ssh->term_height);
10081 if (ssh->eof_needed)
10082 ssh_special(ssh, TS_EOF);
10088 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
10093 s->try_send = FALSE;
10097 * _All_ the connection-layer packets we expect to
10098 * receive are now handled by the dispatch table.
10099 * Anything that reaches here must be bogus.
10102 bombout(("Strange packet received: type %d", pktin->type));
10104 } else if (ssh->mainchan) {
10106 * We have spare data. Add it to the channel buffer.
10108 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
10109 s->try_send = TRUE;
10113 struct ssh_channel *c;
10115 * Try to send data on all channels if we can.
10117 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
10118 ssh2_try_send_and_unthrottle(ssh, c);
10126 * Handlers for SSH-2 messages that might arrive at any moment.
10128 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
10130 /* log reason code in disconnect message */
10132 int reason, msglen;
10134 reason = ssh_pkt_getuint32(pktin);
10135 ssh_pkt_getstring(pktin, &msg, &msglen);
10137 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
10138 buf = dupprintf("Received disconnect message (%s)",
10139 ssh2_disconnect_reasons[reason]);
10141 buf = dupprintf("Received disconnect message (unknown"
10142 " type %d)", reason);
10146 buf = dupprintf("Disconnection message text: %.*s",
10149 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
10151 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
10152 ssh2_disconnect_reasons[reason] : "unknown",
10157 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
10159 /* log the debug message */
10163 /* XXX maybe we should actually take notice of the return value */
10164 ssh2_pkt_getbool(pktin);
10165 ssh_pkt_getstring(pktin, &msg, &msglen);
10167 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
10170 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
10172 do_ssh2_transport(ssh, NULL, 0, pktin);
10176 * Called if we receive a packet that isn't allowed by the protocol.
10177 * This only applies to packets whose meaning PuTTY understands.
10178 * Entirely unknown packets are handled below.
10180 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
10182 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
10183 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
10185 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
10189 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
10191 struct Packet *pktout;
10192 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
10193 ssh2_pkt_adduint32(pktout, pktin->sequence);
10195 * UNIMPLEMENTED messages MUST appear in the same order as the
10196 * messages they respond to. Hence, never queue them.
10198 ssh2_pkt_send_noqueue(ssh, pktout);
10202 * Handle the top-level SSH-2 protocol.
10204 static void ssh2_protocol_setup(Ssh ssh)
10209 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10211 for (i = 0; i < 256; i++)
10212 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10215 * Initially, we only accept transport messages (and a few generic
10216 * ones). do_ssh2_authconn will add more when it starts.
10217 * Messages that are understood but not currently acceptable go to
10218 * ssh2_msg_unexpected.
10220 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10221 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
10222 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
10223 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
10224 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
10225 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
10226 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
10227 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
10228 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
10229 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
10230 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
10231 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
10232 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
10233 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
10234 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
10235 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
10236 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
10237 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
10238 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
10239 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10240 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10241 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10242 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10243 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10244 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10245 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10246 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10247 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10248 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10249 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10250 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10251 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10252 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10255 * These messages have a special handler from the start.
10257 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10258 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
10259 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10262 static void ssh2_bare_connection_protocol_setup(Ssh ssh)
10267 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10269 for (i = 0; i < 256; i++)
10270 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10273 * Initially, we set all ssh-connection messages to 'unexpected';
10274 * do_ssh2_authconn will fill things in properly. We also handle a
10275 * couple of messages from the transport protocol which aren't
10276 * related to key exchange (UNIMPLEMENTED, IGNORE, DEBUG,
10279 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10280 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10281 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10282 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10283 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10284 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10285 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10286 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10287 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10288 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10289 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10290 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10291 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10292 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10294 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10297 * These messages have a special handler from the start.
10299 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10300 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore;
10301 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10304 static void ssh2_timer(void *ctx, unsigned long now)
10306 Ssh ssh = (Ssh)ctx;
10308 if (ssh->state == SSH_STATE_CLOSED)
10311 if (!ssh->kex_in_progress && !ssh->bare_connection &&
10312 conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
10313 now == ssh->next_rekey) {
10314 do_ssh2_transport(ssh, "timeout", -1, NULL);
10318 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
10319 struct Packet *pktin)
10321 unsigned char *in = (unsigned char *)vin;
10322 if (ssh->state == SSH_STATE_CLOSED)
10326 ssh->incoming_data_size += pktin->encrypted_len;
10327 if (!ssh->kex_in_progress &&
10328 ssh->max_data_size != 0 &&
10329 ssh->incoming_data_size > ssh->max_data_size)
10330 do_ssh2_transport(ssh, "too much data received", -1, NULL);
10334 ssh->packet_dispatch[pktin->type](ssh, pktin);
10335 else if (!ssh->protocol_initial_phase_done)
10336 do_ssh2_transport(ssh, in, inlen, pktin);
10338 do_ssh2_authconn(ssh, in, inlen, pktin);
10341 static void ssh2_bare_connection_protocol(Ssh ssh, void *vin, int inlen,
10342 struct Packet *pktin)
10344 unsigned char *in = (unsigned char *)vin;
10345 if (ssh->state == SSH_STATE_CLOSED)
10349 ssh->packet_dispatch[pktin->type](ssh, pktin);
10351 do_ssh2_authconn(ssh, in, inlen, pktin);
10354 static void ssh_cache_conf_values(Ssh ssh)
10356 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
10360 * Called to set up the connection.
10362 * Returns an error message, or NULL on success.
10364 static const char *ssh_init(void *frontend_handle, void **backend_handle,
10365 Conf *conf, char *host, int port, char **realhost,
10366 int nodelay, int keepalive)
10371 ssh = snew(struct ssh_tag);
10372 ssh->conf = conf_copy(conf);
10373 ssh_cache_conf_values(ssh);
10374 ssh->version = 0; /* when not ready yet */
10376 ssh->cipher = NULL;
10377 ssh->v1_cipher_ctx = NULL;
10378 ssh->crcda_ctx = NULL;
10379 ssh->cscipher = NULL;
10380 ssh->cs_cipher_ctx = NULL;
10381 ssh->sccipher = NULL;
10382 ssh->sc_cipher_ctx = NULL;
10384 ssh->cs_mac_ctx = NULL;
10386 ssh->sc_mac_ctx = NULL;
10387 ssh->cscomp = NULL;
10388 ssh->cs_comp_ctx = NULL;
10389 ssh->sccomp = NULL;
10390 ssh->sc_comp_ctx = NULL;
10392 ssh->kex_ctx = NULL;
10393 ssh->hostkey = NULL;
10394 ssh->hostkey_str = NULL;
10395 ssh->exitcode = -1;
10396 ssh->close_expected = FALSE;
10397 ssh->clean_exit = FALSE;
10398 ssh->state = SSH_STATE_PREPACKET;
10399 ssh->size_needed = FALSE;
10400 ssh->eof_needed = FALSE;
10402 ssh->logctx = NULL;
10403 ssh->deferred_send_data = NULL;
10404 ssh->deferred_len = 0;
10405 ssh->deferred_size = 0;
10406 ssh->fallback_cmd = 0;
10407 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
10408 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
10409 ssh->x11disp = NULL;
10410 ssh->x11auth = NULL;
10411 ssh->x11authtree = newtree234(x11_authcmp);
10412 ssh->v1_compressing = FALSE;
10413 ssh->v2_outgoing_sequence = 0;
10414 ssh->ssh1_rdpkt_crstate = 0;
10415 ssh->ssh2_rdpkt_crstate = 0;
10416 ssh->ssh2_bare_rdpkt_crstate = 0;
10417 ssh->ssh_gotdata_crstate = 0;
10418 ssh->do_ssh1_connection_crstate = 0;
10419 ssh->do_ssh_init_state = NULL;
10420 ssh->do_ssh_connection_init_state = NULL;
10421 ssh->do_ssh1_login_state = NULL;
10422 ssh->do_ssh2_transport_state = NULL;
10423 ssh->do_ssh2_authconn_state = NULL;
10426 ssh->mainchan = NULL;
10427 ssh->throttled_all = 0;
10428 ssh->v1_stdout_throttling = 0;
10430 ssh->queuelen = ssh->queuesize = 0;
10431 ssh->queueing = FALSE;
10432 ssh->qhead = ssh->qtail = NULL;
10433 ssh->deferred_rekey_reason = NULL;
10434 bufchain_init(&ssh->queued_incoming_data);
10435 ssh->frozen = FALSE;
10436 ssh->username = NULL;
10437 ssh->sent_console_eof = FALSE;
10438 ssh->got_pty = FALSE;
10439 ssh->bare_connection = FALSE;
10440 ssh->attempting_connshare = FALSE;
10442 *backend_handle = ssh;
10445 if (crypto_startup() == 0)
10446 return "Microsoft high encryption pack not installed!";
10449 ssh->frontend = frontend_handle;
10450 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
10451 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
10453 ssh->channels = NULL;
10454 ssh->rportfwds = NULL;
10455 ssh->portfwds = NULL;
10460 ssh->conn_throttle_count = 0;
10461 ssh->overall_bufsize = 0;
10462 ssh->fallback_cmd = 0;
10464 ssh->protocol = NULL;
10466 ssh->protocol_initial_phase_done = FALSE;
10468 ssh->pinger = NULL;
10470 ssh->incoming_data_size = ssh->outgoing_data_size =
10471 ssh->deferred_data_size = 0L;
10472 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10473 CONF_ssh_rekey_data));
10474 ssh->kex_in_progress = FALSE;
10477 ssh->gsslibs = NULL;
10480 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
10489 static void ssh_free(void *handle)
10491 Ssh ssh = (Ssh) handle;
10492 struct ssh_channel *c;
10493 struct ssh_rportfwd *pf;
10494 struct X11FakeAuth *auth;
10496 if (ssh->v1_cipher_ctx)
10497 ssh->cipher->free_context(ssh->v1_cipher_ctx);
10498 if (ssh->cs_cipher_ctx)
10499 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
10500 if (ssh->sc_cipher_ctx)
10501 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
10502 if (ssh->cs_mac_ctx)
10503 ssh->csmac->free_context(ssh->cs_mac_ctx);
10504 if (ssh->sc_mac_ctx)
10505 ssh->scmac->free_context(ssh->sc_mac_ctx);
10506 if (ssh->cs_comp_ctx) {
10508 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
10510 zlib_compress_cleanup(ssh->cs_comp_ctx);
10512 if (ssh->sc_comp_ctx) {
10514 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
10516 zlib_decompress_cleanup(ssh->sc_comp_ctx);
10519 dh_cleanup(ssh->kex_ctx);
10520 sfree(ssh->savedhost);
10522 while (ssh->queuelen-- > 0)
10523 ssh_free_packet(ssh->queue[ssh->queuelen]);
10526 while (ssh->qhead) {
10527 struct queued_handler *qh = ssh->qhead;
10528 ssh->qhead = qh->next;
10531 ssh->qhead = ssh->qtail = NULL;
10533 if (ssh->channels) {
10534 while ((c = delpos234(ssh->channels, 0)) != NULL) {
10537 if (c->u.x11.xconn != NULL)
10538 x11_close(c->u.x11.xconn);
10540 case CHAN_SOCKDATA:
10541 case CHAN_SOCKDATA_DORMANT:
10542 if (c->u.pfd.pf != NULL)
10543 pfd_close(c->u.pfd.pf);
10546 if (ssh->version == 2) {
10547 struct outstanding_channel_request *ocr, *nocr;
10548 ocr = c->v.v2.chanreq_head;
10550 ocr->handler(c, NULL, ocr->ctx);
10555 bufchain_clear(&c->v.v2.outbuffer);
10559 freetree234(ssh->channels);
10560 ssh->channels = NULL;
10563 if (ssh->connshare)
10564 sharestate_free(ssh->connshare);
10566 if (ssh->rportfwds) {
10567 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
10569 freetree234(ssh->rportfwds);
10570 ssh->rportfwds = NULL;
10572 sfree(ssh->deferred_send_data);
10574 x11_free_display(ssh->x11disp);
10575 while ((auth = delpos234(ssh->x11authtree, 0)) != NULL)
10576 x11_free_fake_auth(auth);
10577 freetree234(ssh->x11authtree);
10578 sfree(ssh->do_ssh_init_state);
10579 sfree(ssh->do_ssh1_login_state);
10580 sfree(ssh->do_ssh2_transport_state);
10581 sfree(ssh->do_ssh2_authconn_state);
10584 sfree(ssh->fullhostname);
10585 sfree(ssh->hostkey_str);
10586 if (ssh->crcda_ctx) {
10587 crcda_free_context(ssh->crcda_ctx);
10588 ssh->crcda_ctx = NULL;
10591 ssh_do_close(ssh, TRUE);
10592 expire_timer_context(ssh);
10594 pinger_free(ssh->pinger);
10595 bufchain_clear(&ssh->queued_incoming_data);
10596 sfree(ssh->username);
10597 conf_free(ssh->conf);
10600 ssh_gss_cleanup(ssh->gsslibs);
10608 * Reconfigure the SSH backend.
10610 static void ssh_reconfig(void *handle, Conf *conf)
10612 Ssh ssh = (Ssh) handle;
10613 char *rekeying = NULL, rekey_mandatory = FALSE;
10614 unsigned long old_max_data_size;
10617 pinger_reconfig(ssh->pinger, ssh->conf, conf);
10619 ssh_setup_portfwd(ssh, conf);
10621 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
10622 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
10624 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
10625 unsigned long now = GETTICKCOUNT();
10627 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
10628 rekeying = "timeout shortened";
10630 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
10634 old_max_data_size = ssh->max_data_size;
10635 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10636 CONF_ssh_rekey_data));
10637 if (old_max_data_size != ssh->max_data_size &&
10638 ssh->max_data_size != 0) {
10639 if (ssh->outgoing_data_size > ssh->max_data_size ||
10640 ssh->incoming_data_size > ssh->max_data_size)
10641 rekeying = "data limit lowered";
10644 if (conf_get_int(ssh->conf, CONF_compression) !=
10645 conf_get_int(conf, CONF_compression)) {
10646 rekeying = "compression setting changed";
10647 rekey_mandatory = TRUE;
10650 for (i = 0; i < CIPHER_MAX; i++)
10651 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
10652 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
10653 rekeying = "cipher settings changed";
10654 rekey_mandatory = TRUE;
10656 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
10657 conf_get_int(conf, CONF_ssh2_des_cbc)) {
10658 rekeying = "cipher settings changed";
10659 rekey_mandatory = TRUE;
10662 conf_free(ssh->conf);
10663 ssh->conf = conf_copy(conf);
10664 ssh_cache_conf_values(ssh);
10666 if (!ssh->bare_connection && rekeying) {
10667 if (!ssh->kex_in_progress) {
10668 do_ssh2_transport(ssh, rekeying, -1, NULL);
10669 } else if (rekey_mandatory) {
10670 ssh->deferred_rekey_reason = rekeying;
10676 * Called to send data down the SSH connection.
10678 static int ssh_send(void *handle, char *buf, int len)
10680 Ssh ssh = (Ssh) handle;
10682 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10685 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
10687 return ssh_sendbuffer(ssh);
10691 * Called to query the current amount of buffered stdin data.
10693 static int ssh_sendbuffer(void *handle)
10695 Ssh ssh = (Ssh) handle;
10696 int override_value;
10698 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10702 * If the SSH socket itself has backed up, add the total backup
10703 * size on that to any individual buffer on the stdin channel.
10705 override_value = 0;
10706 if (ssh->throttled_all)
10707 override_value = ssh->overall_bufsize;
10709 if (ssh->version == 1) {
10710 return override_value;
10711 } else if (ssh->version == 2) {
10712 if (!ssh->mainchan)
10713 return override_value;
10715 return (override_value +
10716 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
10723 * Called to set the size of the window from SSH's POV.
10725 static void ssh_size(void *handle, int width, int height)
10727 Ssh ssh = (Ssh) handle;
10728 struct Packet *pktout;
10730 ssh->term_width = width;
10731 ssh->term_height = height;
10733 switch (ssh->state) {
10734 case SSH_STATE_BEFORE_SIZE:
10735 case SSH_STATE_PREPACKET:
10736 case SSH_STATE_CLOSED:
10737 break; /* do nothing */
10738 case SSH_STATE_INTERMED:
10739 ssh->size_needed = TRUE; /* buffer for later */
10741 case SSH_STATE_SESSION:
10742 if (!conf_get_int(ssh->conf, CONF_nopty)) {
10743 if (ssh->version == 1) {
10744 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
10745 PKT_INT, ssh->term_height,
10746 PKT_INT, ssh->term_width,
10747 PKT_INT, 0, PKT_INT, 0, PKT_END);
10748 } else if (ssh->mainchan) {
10749 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
10751 ssh2_pkt_adduint32(pktout, ssh->term_width);
10752 ssh2_pkt_adduint32(pktout, ssh->term_height);
10753 ssh2_pkt_adduint32(pktout, 0);
10754 ssh2_pkt_adduint32(pktout, 0);
10755 ssh2_pkt_send(ssh, pktout);
10763 * Return a list of the special codes that make sense in this
10766 static const struct telnet_special *ssh_get_specials(void *handle)
10768 static const struct telnet_special ssh1_ignore_special[] = {
10769 {"IGNORE message", TS_NOP}
10771 static const struct telnet_special ssh2_ignore_special[] = {
10772 {"IGNORE message", TS_NOP},
10774 static const struct telnet_special ssh2_rekey_special[] = {
10775 {"Repeat key exchange", TS_REKEY},
10777 static const struct telnet_special ssh2_session_specials[] = {
10780 /* These are the signal names defined by RFC 4254.
10781 * They include all the ISO C signals, but are a subset of the POSIX
10782 * required signals. */
10783 {"SIGINT (Interrupt)", TS_SIGINT},
10784 {"SIGTERM (Terminate)", TS_SIGTERM},
10785 {"SIGKILL (Kill)", TS_SIGKILL},
10786 {"SIGQUIT (Quit)", TS_SIGQUIT},
10787 {"SIGHUP (Hangup)", TS_SIGHUP},
10788 {"More signals", TS_SUBMENU},
10789 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
10790 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
10791 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
10792 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
10793 {NULL, TS_EXITMENU}
10795 static const struct telnet_special specials_end[] = {
10796 {NULL, TS_EXITMENU}
10798 /* XXX review this length for any changes: */
10799 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
10800 lenof(ssh2_rekey_special) +
10801 lenof(ssh2_session_specials) +
10802 lenof(specials_end)];
10803 Ssh ssh = (Ssh) handle;
10805 #define ADD_SPECIALS(name) \
10807 assert((i + lenof(name)) <= lenof(ssh_specials)); \
10808 memcpy(&ssh_specials[i], name, sizeof name); \
10809 i += lenof(name); \
10812 if (ssh->version == 1) {
10813 /* Don't bother offering IGNORE if we've decided the remote
10814 * won't cope with it, since we wouldn't bother sending it if
10816 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
10817 ADD_SPECIALS(ssh1_ignore_special);
10818 } else if (ssh->version == 2) {
10819 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
10820 ADD_SPECIALS(ssh2_ignore_special);
10821 if (!(ssh->remote_bugs & BUG_SSH2_REKEY) && !ssh->bare_connection)
10822 ADD_SPECIALS(ssh2_rekey_special);
10824 ADD_SPECIALS(ssh2_session_specials);
10825 } /* else we're not ready yet */
10828 ADD_SPECIALS(specials_end);
10829 return ssh_specials;
10833 #undef ADD_SPECIALS
10837 * Send special codes. TS_EOF is useful for `plink', so you
10838 * can send an EOF and collect resulting output (e.g. `plink
10841 static void ssh_special(void *handle, Telnet_Special code)
10843 Ssh ssh = (Ssh) handle;
10844 struct Packet *pktout;
10846 if (code == TS_EOF) {
10847 if (ssh->state != SSH_STATE_SESSION) {
10849 * Buffer the EOF in case we are pre-SESSION, so we can
10850 * send it as soon as we reach SESSION.
10852 if (code == TS_EOF)
10853 ssh->eof_needed = TRUE;
10856 if (ssh->version == 1) {
10857 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
10858 } else if (ssh->mainchan) {
10859 sshfwd_write_eof(ssh->mainchan);
10860 ssh->send_ok = 0; /* now stop trying to read from stdin */
10862 logevent("Sent EOF message");
10863 } else if (code == TS_PING || code == TS_NOP) {
10864 if (ssh->state == SSH_STATE_CLOSED
10865 || ssh->state == SSH_STATE_PREPACKET) return;
10866 if (ssh->version == 1) {
10867 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
10868 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
10870 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
10871 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
10872 ssh2_pkt_addstring_start(pktout);
10873 ssh2_pkt_send_noqueue(ssh, pktout);
10876 } else if (code == TS_REKEY) {
10877 if (!ssh->kex_in_progress && !ssh->bare_connection &&
10878 ssh->version == 2) {
10879 do_ssh2_transport(ssh, "at user request", -1, NULL);
10881 } else if (code == TS_BRK) {
10882 if (ssh->state == SSH_STATE_CLOSED
10883 || ssh->state == SSH_STATE_PREPACKET) return;
10884 if (ssh->version == 1) {
10885 logevent("Unable to send BREAK signal in SSH-1");
10886 } else if (ssh->mainchan) {
10887 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
10888 ssh2_pkt_adduint32(pktout, 0); /* default break length */
10889 ssh2_pkt_send(ssh, pktout);
10892 /* Is is a POSIX signal? */
10893 char *signame = NULL;
10894 if (code == TS_SIGABRT) signame = "ABRT";
10895 if (code == TS_SIGALRM) signame = "ALRM";
10896 if (code == TS_SIGFPE) signame = "FPE";
10897 if (code == TS_SIGHUP) signame = "HUP";
10898 if (code == TS_SIGILL) signame = "ILL";
10899 if (code == TS_SIGINT) signame = "INT";
10900 if (code == TS_SIGKILL) signame = "KILL";
10901 if (code == TS_SIGPIPE) signame = "PIPE";
10902 if (code == TS_SIGQUIT) signame = "QUIT";
10903 if (code == TS_SIGSEGV) signame = "SEGV";
10904 if (code == TS_SIGTERM) signame = "TERM";
10905 if (code == TS_SIGUSR1) signame = "USR1";
10906 if (code == TS_SIGUSR2) signame = "USR2";
10907 /* The SSH-2 protocol does in principle support arbitrary named
10908 * signals, including signame@domain, but we don't support those. */
10910 /* It's a signal. */
10911 if (ssh->version == 2 && ssh->mainchan) {
10912 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
10913 ssh2_pkt_addstring(pktout, signame);
10914 ssh2_pkt_send(ssh, pktout);
10915 logeventf(ssh, "Sent signal SIG%s", signame);
10918 /* Never heard of it. Do nothing */
10923 void *new_sock_channel(void *handle, struct PortForwarding *pf)
10925 Ssh ssh = (Ssh) handle;
10926 struct ssh_channel *c;
10927 c = snew(struct ssh_channel);
10930 ssh2_channel_init(c);
10931 c->halfopen = TRUE;
10932 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
10934 add234(ssh->channels, c);
10938 unsigned ssh_alloc_sharing_channel(Ssh ssh, void *sharing_ctx)
10940 struct ssh_channel *c;
10941 c = snew(struct ssh_channel);
10944 ssh2_channel_init(c);
10945 c->type = CHAN_SHARING;
10946 c->u.sharing.ctx = sharing_ctx;
10947 add234(ssh->channels, c);
10951 void ssh_delete_sharing_channel(Ssh ssh, unsigned localid)
10953 struct ssh_channel *c;
10955 c = find234(ssh->channels, &localid, ssh_channelfind);
10957 ssh_channel_destroy(c);
10960 void ssh_send_packet_from_downstream(Ssh ssh, unsigned id, int type,
10961 const void *data, int datalen,
10962 const char *additional_log_text)
10964 struct Packet *pkt;
10966 pkt = ssh2_pkt_init(type);
10967 pkt->downstream_id = id;
10968 pkt->additional_log_text = additional_log_text;
10969 ssh2_pkt_adddata(pkt, data, datalen);
10970 ssh2_pkt_send(ssh, pkt);
10974 * This is called when stdout/stderr (the entity to which
10975 * from_backend sends data) manages to clear some backlog.
10977 static void ssh_unthrottle(void *handle, int bufsize)
10979 Ssh ssh = (Ssh) handle;
10982 if (ssh->version == 1) {
10983 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
10984 ssh->v1_stdout_throttling = 0;
10985 ssh_throttle_conn(ssh, -1);
10988 if (ssh->mainchan) {
10989 ssh2_set_window(ssh->mainchan,
10990 bufsize < ssh->mainchan->v.v2.locmaxwin ?
10991 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
10992 if (ssh_is_simple(ssh))
10995 buflimit = ssh->mainchan->v.v2.locmaxwin;
10996 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
10997 ssh->mainchan->throttling_conn = 0;
10998 ssh_throttle_conn(ssh, -1);
11004 * Now process any SSH connection data that was stashed in our
11005 * queue while we were frozen.
11007 ssh_process_queued_incoming_data(ssh);
11010 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
11012 struct ssh_channel *c = (struct ssh_channel *)channel;
11014 struct Packet *pktout;
11016 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
11018 if (ssh->version == 1) {
11019 send_packet(ssh, SSH1_MSG_PORT_OPEN,
11020 PKT_INT, c->localid,
11023 /* PKT_STR, <org:orgport>, */
11026 pktout = ssh2_chanopen_init(c, "direct-tcpip");
11027 ssh2_pkt_addstring(pktout, hostname);
11028 ssh2_pkt_adduint32(pktout, port);
11030 * We make up values for the originator data; partly it's
11031 * too much hassle to keep track, and partly I'm not
11032 * convinced the server should be told details like that
11033 * about my local network configuration.
11034 * The "originator IP address" is syntactically a numeric
11035 * IP address, and some servers (e.g., Tectia) get upset
11036 * if it doesn't match this syntax.
11038 ssh2_pkt_addstring(pktout, "0.0.0.0");
11039 ssh2_pkt_adduint32(pktout, 0);
11040 ssh2_pkt_send(ssh, pktout);
11044 static int ssh_connected(void *handle)
11046 Ssh ssh = (Ssh) handle;
11047 return ssh->s != NULL;
11050 static int ssh_sendok(void *handle)
11052 Ssh ssh = (Ssh) handle;
11053 return ssh->send_ok;
11056 static int ssh_ldisc(void *handle, int option)
11058 Ssh ssh = (Ssh) handle;
11059 if (option == LD_ECHO)
11060 return ssh->echoing;
11061 if (option == LD_EDIT)
11062 return ssh->editing;
11066 static void ssh_provide_ldisc(void *handle, void *ldisc)
11068 Ssh ssh = (Ssh) handle;
11069 ssh->ldisc = ldisc;
11072 static void ssh_provide_logctx(void *handle, void *logctx)
11074 Ssh ssh = (Ssh) handle;
11075 ssh->logctx = logctx;
11078 static int ssh_return_exitcode(void *handle)
11080 Ssh ssh = (Ssh) handle;
11081 if (ssh->s != NULL)
11084 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
11088 * cfg_info for SSH is the currently running version of the
11089 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
11091 static int ssh_cfg_info(void *handle)
11093 Ssh ssh = (Ssh) handle;
11094 return ssh->version;
11098 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
11099 * that fails. This variable is the means by which scp.c can reach
11100 * into the SSH code and find out which one it got.
11102 extern int ssh_fallback_cmd(void *handle)
11104 Ssh ssh = (Ssh) handle;
11105 return ssh->fallback_cmd;
11108 Backend ssh_backend = {
11118 ssh_return_exitcode,
11122 ssh_provide_logctx,