28 * Packet type contexts, so that ssh2_pkt_type can correctly decode
29 * the ambiguous type numbers back into the correct type strings.
40 SSH2_PKTCTX_PUBLICKEY,
46 static const char *const ssh2_disconnect_reasons[] = {
48 "host not allowed to connect",
50 "key exchange failed",
51 "host authentication failed",
54 "service not available",
55 "protocol version not supported",
56 "host key not verifiable",
59 "too many connections",
60 "auth cancelled by user",
61 "no more auth methods available",
66 * Various remote-bug flags.
68 #define BUG_CHOKES_ON_SSH1_IGNORE 1
69 #define BUG_SSH2_HMAC 2
70 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
71 #define BUG_CHOKES_ON_RSA 8
72 #define BUG_SSH2_RSA_PADDING 16
73 #define BUG_SSH2_DERIVEKEY 32
74 #define BUG_SSH2_REKEY 64
75 #define BUG_SSH2_PK_SESSIONID 128
76 #define BUG_SSH2_MAXPKT 256
77 #define BUG_CHOKES_ON_SSH2_IGNORE 512
78 #define BUG_CHOKES_ON_WINADJ 1024
79 #define BUG_SENDS_LATE_REQUEST_REPLY 2048
82 * Codes for terminal modes.
83 * Most of these are the same in SSH-1 and SSH-2.
84 * This list is derived from RFC 4254 and
88 const char* const mode;
90 enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
92 /* "V" prefix discarded for special characters relative to SSH specs */
93 { "INTR", 1, TTY_OP_CHAR },
94 { "QUIT", 2, TTY_OP_CHAR },
95 { "ERASE", 3, TTY_OP_CHAR },
96 { "KILL", 4, TTY_OP_CHAR },
97 { "EOF", 5, TTY_OP_CHAR },
98 { "EOL", 6, TTY_OP_CHAR },
99 { "EOL2", 7, TTY_OP_CHAR },
100 { "START", 8, TTY_OP_CHAR },
101 { "STOP", 9, TTY_OP_CHAR },
102 { "SUSP", 10, TTY_OP_CHAR },
103 { "DSUSP", 11, TTY_OP_CHAR },
104 { "REPRINT", 12, TTY_OP_CHAR },
105 { "WERASE", 13, TTY_OP_CHAR },
106 { "LNEXT", 14, TTY_OP_CHAR },
107 { "FLUSH", 15, TTY_OP_CHAR },
108 { "SWTCH", 16, TTY_OP_CHAR },
109 { "STATUS", 17, TTY_OP_CHAR },
110 { "DISCARD", 18, TTY_OP_CHAR },
111 { "IGNPAR", 30, TTY_OP_BOOL },
112 { "PARMRK", 31, TTY_OP_BOOL },
113 { "INPCK", 32, TTY_OP_BOOL },
114 { "ISTRIP", 33, TTY_OP_BOOL },
115 { "INLCR", 34, TTY_OP_BOOL },
116 { "IGNCR", 35, TTY_OP_BOOL },
117 { "ICRNL", 36, TTY_OP_BOOL },
118 { "IUCLC", 37, TTY_OP_BOOL },
119 { "IXON", 38, TTY_OP_BOOL },
120 { "IXANY", 39, TTY_OP_BOOL },
121 { "IXOFF", 40, TTY_OP_BOOL },
122 { "IMAXBEL", 41, TTY_OP_BOOL },
123 { "ISIG", 50, TTY_OP_BOOL },
124 { "ICANON", 51, TTY_OP_BOOL },
125 { "XCASE", 52, TTY_OP_BOOL },
126 { "ECHO", 53, TTY_OP_BOOL },
127 { "ECHOE", 54, TTY_OP_BOOL },
128 { "ECHOK", 55, TTY_OP_BOOL },
129 { "ECHONL", 56, TTY_OP_BOOL },
130 { "NOFLSH", 57, TTY_OP_BOOL },
131 { "TOSTOP", 58, TTY_OP_BOOL },
132 { "IEXTEN", 59, TTY_OP_BOOL },
133 { "ECHOCTL", 60, TTY_OP_BOOL },
134 { "ECHOKE", 61, TTY_OP_BOOL },
135 { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */
136 { "OPOST", 70, TTY_OP_BOOL },
137 { "OLCUC", 71, TTY_OP_BOOL },
138 { "ONLCR", 72, TTY_OP_BOOL },
139 { "OCRNL", 73, TTY_OP_BOOL },
140 { "ONOCR", 74, TTY_OP_BOOL },
141 { "ONLRET", 75, TTY_OP_BOOL },
142 { "CS7", 90, TTY_OP_BOOL },
143 { "CS8", 91, TTY_OP_BOOL },
144 { "PARENB", 92, TTY_OP_BOOL },
145 { "PARODD", 93, TTY_OP_BOOL }
148 /* Miscellaneous other tty-related constants. */
149 #define SSH_TTY_OP_END 0
150 /* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */
151 #define SSH1_TTY_OP_ISPEED 192
152 #define SSH1_TTY_OP_OSPEED 193
153 #define SSH2_TTY_OP_ISPEED 128
154 #define SSH2_TTY_OP_OSPEED 129
156 /* Helper functions for parsing tty-related config. */
157 static unsigned int ssh_tty_parse_specchar(char *s)
162 ret = ctrlparse(s, &next);
163 if (!next) ret = s[0];
165 ret = 255; /* special value meaning "don't set" */
169 static unsigned int ssh_tty_parse_boolean(char *s)
171 if (stricmp(s, "yes") == 0 ||
172 stricmp(s, "on") == 0 ||
173 stricmp(s, "true") == 0 ||
174 stricmp(s, "+") == 0)
176 else if (stricmp(s, "no") == 0 ||
177 stricmp(s, "off") == 0 ||
178 stricmp(s, "false") == 0 ||
179 stricmp(s, "-") == 0)
180 return 0; /* false */
182 return (atoi(s) != 0);
185 #define translate(x) if (type == x) return #x
186 #define translatek(x,ctx) if (type == x && (pkt_kctx == ctx)) return #x
187 #define translatea(x,ctx) if (type == x && (pkt_actx == ctx)) return #x
188 static char *ssh1_pkt_type(int type)
190 translate(SSH1_MSG_DISCONNECT);
191 translate(SSH1_SMSG_PUBLIC_KEY);
192 translate(SSH1_CMSG_SESSION_KEY);
193 translate(SSH1_CMSG_USER);
194 translate(SSH1_CMSG_AUTH_RSA);
195 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
196 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
197 translate(SSH1_CMSG_AUTH_PASSWORD);
198 translate(SSH1_CMSG_REQUEST_PTY);
199 translate(SSH1_CMSG_WINDOW_SIZE);
200 translate(SSH1_CMSG_EXEC_SHELL);
201 translate(SSH1_CMSG_EXEC_CMD);
202 translate(SSH1_SMSG_SUCCESS);
203 translate(SSH1_SMSG_FAILURE);
204 translate(SSH1_CMSG_STDIN_DATA);
205 translate(SSH1_SMSG_STDOUT_DATA);
206 translate(SSH1_SMSG_STDERR_DATA);
207 translate(SSH1_CMSG_EOF);
208 translate(SSH1_SMSG_EXIT_STATUS);
209 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
210 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
211 translate(SSH1_MSG_CHANNEL_DATA);
212 translate(SSH1_MSG_CHANNEL_CLOSE);
213 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
214 translate(SSH1_SMSG_X11_OPEN);
215 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
216 translate(SSH1_MSG_PORT_OPEN);
217 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
218 translate(SSH1_SMSG_AGENT_OPEN);
219 translate(SSH1_MSG_IGNORE);
220 translate(SSH1_CMSG_EXIT_CONFIRMATION);
221 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
222 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
223 translate(SSH1_MSG_DEBUG);
224 translate(SSH1_CMSG_REQUEST_COMPRESSION);
225 translate(SSH1_CMSG_AUTH_TIS);
226 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
227 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
228 translate(SSH1_CMSG_AUTH_CCARD);
229 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
230 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
233 static char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx, int type)
235 translatea(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,SSH2_PKTCTX_GSSAPI);
236 translatea(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,SSH2_PKTCTX_GSSAPI);
237 translatea(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,SSH2_PKTCTX_GSSAPI);
238 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERROR,SSH2_PKTCTX_GSSAPI);
239 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK,SSH2_PKTCTX_GSSAPI);
240 translatea(SSH2_MSG_USERAUTH_GSSAPI_MIC, SSH2_PKTCTX_GSSAPI);
241 translate(SSH2_MSG_DISCONNECT);
242 translate(SSH2_MSG_IGNORE);
243 translate(SSH2_MSG_UNIMPLEMENTED);
244 translate(SSH2_MSG_DEBUG);
245 translate(SSH2_MSG_SERVICE_REQUEST);
246 translate(SSH2_MSG_SERVICE_ACCEPT);
247 translate(SSH2_MSG_KEXINIT);
248 translate(SSH2_MSG_NEWKEYS);
249 translatek(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
250 translatek(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
251 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
252 translatek(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
253 translatek(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
254 translatek(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
255 translatek(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX);
256 translatek(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX);
257 translatek(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX);
258 translatek(SSH2_MSG_KEX_ECDH_INIT, SSH2_PKTCTX_ECDHKEX);
259 translatek(SSH2_MSG_KEX_ECDH_REPLY, SSH2_PKTCTX_ECDHKEX);
260 translate(SSH2_MSG_USERAUTH_REQUEST);
261 translate(SSH2_MSG_USERAUTH_FAILURE);
262 translate(SSH2_MSG_USERAUTH_SUCCESS);
263 translate(SSH2_MSG_USERAUTH_BANNER);
264 translatea(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
265 translatea(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
266 translatea(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
267 translatea(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
268 translate(SSH2_MSG_GLOBAL_REQUEST);
269 translate(SSH2_MSG_REQUEST_SUCCESS);
270 translate(SSH2_MSG_REQUEST_FAILURE);
271 translate(SSH2_MSG_CHANNEL_OPEN);
272 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
273 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
274 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
275 translate(SSH2_MSG_CHANNEL_DATA);
276 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
277 translate(SSH2_MSG_CHANNEL_EOF);
278 translate(SSH2_MSG_CHANNEL_CLOSE);
279 translate(SSH2_MSG_CHANNEL_REQUEST);
280 translate(SSH2_MSG_CHANNEL_SUCCESS);
281 translate(SSH2_MSG_CHANNEL_FAILURE);
287 /* Enumeration values for fields in SSH-1 packets */
289 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
293 * Coroutine mechanics for the sillier bits of the code. If these
294 * macros look impenetrable to you, you might find it helpful to
297 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
299 * which explains the theory behind these macros.
301 * In particular, if you are getting `case expression not constant'
302 * errors when building with MS Visual Studio, this is because MS's
303 * Edit and Continue debugging feature causes their compiler to
304 * violate ANSI C. To disable Edit and Continue debugging:
306 * - right-click ssh.c in the FileView
308 * - select the C/C++ tab and the General category
309 * - under `Debug info:', select anything _other_ than `Program
310 * Database for Edit and Continue'.
312 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
313 #define crBeginState crBegin(s->crLine)
314 #define crStateP(t, v) \
316 if (!(v)) { s = (v) = snew(struct t); s->crLine = 0; } \
318 #define crState(t) crStateP(t, ssh->t)
319 #define crFinish(z) } *crLine = 0; return (z); }
320 #define crFinishV } *crLine = 0; return; }
321 #define crFinishFree(z) } sfree(s); return (z); }
322 #define crFinishFreeV } sfree(s); return; }
323 #define crReturn(z) \
325 *crLine =__LINE__; return (z); case __LINE__:;\
329 *crLine=__LINE__; return; case __LINE__:;\
331 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
332 #define crStopV do{ *crLine = 0; return; }while(0)
333 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
334 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
338 static struct Packet *ssh1_pkt_init(int pkt_type);
339 static struct Packet *ssh2_pkt_init(int pkt_type);
340 static void ssh_pkt_ensure(struct Packet *, int length);
341 static void ssh_pkt_adddata(struct Packet *, const void *data, int len);
342 static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
343 static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
344 static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
345 static void ssh_pkt_addstring_start(struct Packet *);
346 static void ssh_pkt_addstring_str(struct Packet *, const char *data);
347 static void ssh_pkt_addstring_data(struct Packet *, const char *data, int len);
348 static void ssh_pkt_addstring(struct Packet *, const char *data);
349 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
350 static void ssh1_pkt_addmp(struct Packet *, Bignum b);
351 static void ssh2_pkt_addmp(struct Packet *, Bignum b);
352 static int ssh2_pkt_construct(Ssh, struct Packet *);
353 static void ssh2_pkt_send(Ssh, struct Packet *);
354 static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
355 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
356 struct Packet *pktin);
357 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
358 struct Packet *pktin);
359 static void ssh2_channel_check_close(struct ssh_channel *c);
360 static void ssh_channel_destroy(struct ssh_channel *c);
363 * Buffer management constants. There are several of these for
364 * various different purposes:
366 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
367 * on a local data stream before we throttle the whole SSH
368 * connection (in SSH-1 only). Throttling the whole connection is
369 * pretty drastic so we set this high in the hope it won't
372 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
373 * on the SSH connection itself before we defensively throttle
374 * _all_ local data streams. This is pretty drastic too (though
375 * thankfully unlikely in SSH-2 since the window mechanism should
376 * ensure that the server never has any need to throttle its end
377 * of the connection), so we set this high as well.
379 * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
382 * - OUR_V2_BIGWIN is the window size we advertise for the only
383 * channel in a simple connection. It must be <= INT_MAX.
385 * - OUR_V2_MAXPKT is the official "maximum packet size" we send
386 * to the remote side. This actually has nothing to do with the
387 * size of the _packet_, but is instead a limit on the amount
388 * of data we're willing to receive in a single SSH2 channel
391 * - OUR_V2_PACKETLIMIT is actually the maximum size of SSH
392 * _packet_ we're prepared to cope with. It must be a multiple
393 * of the cipher block size, and must be at least 35000.
396 #define SSH1_BUFFER_LIMIT 32768
397 #define SSH_MAX_BACKLOG 32768
398 #define OUR_V2_WINSIZE 16384
399 #define OUR_V2_BIGWIN 0x7fffffff
400 #define OUR_V2_MAXPKT 0x4000UL
401 #define OUR_V2_PACKETLIMIT 0x9000UL
403 const static struct ssh_signkey *hostkey_algs[] = {
404 &ssh_ecdsa_nistp256, &ssh_ecdsa_nistp384, &ssh_ecdsa_nistp521,
408 const static struct ssh_mac *macs[] = {
409 &ssh_hmac_sha256, &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
411 const static struct ssh_mac *buggymacs[] = {
412 &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
415 static void *ssh_comp_none_init(void)
419 static void ssh_comp_none_cleanup(void *handle)
422 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
423 unsigned char **outblock, int *outlen)
427 static int ssh_comp_none_disable(void *handle)
431 const static struct ssh_compress ssh_comp_none = {
433 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
434 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
435 ssh_comp_none_disable, NULL
437 extern const struct ssh_compress ssh_zlib;
438 const static struct ssh_compress *compressions[] = {
439 &ssh_zlib, &ssh_comp_none
442 enum { /* channel types */
447 CHAN_SOCKDATA_DORMANT, /* one the remote hasn't confirmed */
449 * CHAN_SHARING indicates a channel which is tracked here on
450 * behalf of a connection-sharing downstream. We do almost nothing
451 * with these channels ourselves: all messages relating to them
452 * get thrown straight to sshshare.c and passed on almost
453 * unmodified to downstream.
457 * CHAN_ZOMBIE is used to indicate a channel for which we've
458 * already destroyed the local data source: for instance, if a
459 * forwarded port experiences a socket error on the local side, we
460 * immediately destroy its local socket and turn the SSH channel
466 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
467 typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
468 typedef void (*cchandler_fn_t)(struct ssh_channel *, struct Packet *, void *);
471 * Each channel has a queue of outstanding CHANNEL_REQUESTS and their
474 struct outstanding_channel_request {
475 cchandler_fn_t handler;
477 struct outstanding_channel_request *next;
481 * 2-3-4 tree storing channels.
484 Ssh ssh; /* pointer back to main context */
485 unsigned remoteid, localid;
487 /* True if we opened this channel but server hasn't confirmed. */
490 * In SSH-1, this value contains four bits:
492 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
493 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
494 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
495 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
497 * A channel is completely finished with when all four bits are set.
499 * In SSH-2, the four bits mean:
501 * 1 We have sent SSH2_MSG_CHANNEL_EOF.
502 * 2 We have sent SSH2_MSG_CHANNEL_CLOSE.
503 * 4 We have received SSH2_MSG_CHANNEL_EOF.
504 * 8 We have received SSH2_MSG_CHANNEL_CLOSE.
506 * A channel is completely finished with when we have both sent
507 * and received CLOSE.
509 * The symbolic constants below use the SSH-2 terminology, which
510 * is a bit confusing in SSH-1, but we have to use _something_.
512 #define CLOSES_SENT_EOF 1
513 #define CLOSES_SENT_CLOSE 2
514 #define CLOSES_RCVD_EOF 4
515 #define CLOSES_RCVD_CLOSE 8
519 * This flag indicates that an EOF is pending on the outgoing side
520 * of the channel: that is, wherever we're getting the data for
521 * this channel has sent us some data followed by EOF. We can't
522 * actually send the EOF until we've finished sending the data, so
523 * we set this flag instead to remind us to do so once our buffer
529 * True if this channel is causing the underlying connection to be
534 struct ssh2_data_channel {
536 unsigned remwindow, remmaxpkt;
537 /* locwindow is signed so we can cope with excess data. */
538 int locwindow, locmaxwin;
540 * remlocwin is the amount of local window that we think
541 * the remote end had available to it after it sent the
542 * last data packet or window adjust ack.
546 * These store the list of channel requests that haven't
549 struct outstanding_channel_request *chanreq_head, *chanreq_tail;
550 enum { THROTTLED, UNTHROTTLING, UNTHROTTLED } throttle_state;
554 struct ssh_agent_channel {
555 unsigned char *message;
556 unsigned char msglen[4];
557 unsigned lensofar, totallen;
558 int outstanding_requests;
560 struct ssh_x11_channel {
561 struct X11Connection *xconn;
564 struct ssh_pfd_channel {
565 struct PortForwarding *pf;
567 struct ssh_sharing_channel {
574 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
575 * use this structure in different ways, reflecting SSH-2's
576 * altogether saner approach to port forwarding.
578 * In SSH-1, you arrange a remote forwarding by sending the server
579 * the remote port number, and the local destination host:port.
580 * When a connection comes in, the server sends you back that
581 * host:port pair, and you connect to it. This is a ready-made
582 * security hole if you're not on the ball: a malicious server
583 * could send you back _any_ host:port pair, so if you trustingly
584 * connect to the address it gives you then you've just opened the
585 * entire inside of your corporate network just by connecting
586 * through it to a dodgy SSH server. Hence, we must store a list of
587 * host:port pairs we _are_ trying to forward to, and reject a
588 * connection request from the server if it's not in the list.
590 * In SSH-2, each side of the connection minds its own business and
591 * doesn't send unnecessary information to the other. You arrange a
592 * remote forwarding by sending the server just the remote port
593 * number. When a connection comes in, the server tells you which
594 * of its ports was connected to; and _you_ have to remember what
595 * local host:port pair went with that port number.
597 * Hence, in SSH-1 this structure is indexed by destination
598 * host:port pair, whereas in SSH-2 it is indexed by source port.
600 struct ssh_portfwd; /* forward declaration */
602 struct ssh_rportfwd {
603 unsigned sport, dport;
607 struct ssh_portfwd *pfrec;
610 static void free_rportfwd(struct ssh_rportfwd *pf)
613 sfree(pf->sportdesc);
621 * Separately to the rportfwd tree (which is for looking up port
622 * open requests from the server), a tree of _these_ structures is
623 * used to keep track of all the currently open port forwardings,
624 * so that we can reconfigure in mid-session if the user requests
628 enum { DESTROY, KEEP, CREATE } status;
630 unsigned sport, dport;
633 struct ssh_rportfwd *remote;
635 struct PortListener *local;
637 #define free_portfwd(pf) ( \
638 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
639 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
642 long length; /* length of packet: see below */
643 long forcepad; /* SSH-2: force padding to at least this length */
644 int type; /* only used for incoming packets */
645 unsigned long sequence; /* SSH-2 incoming sequence number */
646 unsigned char *data; /* allocated storage */
647 unsigned char *body; /* offset of payload within `data' */
648 long savedpos; /* dual-purpose saved packet position: see below */
649 long maxlen; /* amount of storage allocated for `data' */
650 long encrypted_len; /* for SSH-2 total-size counting */
653 * A note on the 'length' and 'savedpos' fields above.
655 * Incoming packets are set up so that pkt->length is measured
656 * relative to pkt->body, which itself points to a few bytes after
657 * pkt->data (skipping some uninteresting header fields including
658 * the packet type code). The ssh_pkt_get* functions all expect
659 * this setup, and they also use pkt->savedpos to indicate how far
660 * through the packet being decoded they've got - and that, too,
661 * is an offset from pkt->body rather than pkt->data.
663 * During construction of an outgoing packet, however, pkt->length
664 * is measured relative to the base pointer pkt->data, and
665 * pkt->body is not really used for anything until the packet is
666 * ready for sending. In this mode, pkt->savedpos is reused as a
667 * temporary variable by the addstring functions, which write out
668 * a string length field and then keep going back and updating it
669 * as more data is appended to the subsequent string data field;
670 * pkt->savedpos stores the offset (again relative to pkt->data)
671 * of the start of the string data field.
674 /* Extra metadata used in SSH packet logging mode, allowing us to
675 * log in the packet header line that the packet came from a
676 * connection-sharing downstream and what if anything unusual was
677 * done to it. The additional_log_text field is expected to be a
678 * static string - it will not be freed. */
679 unsigned downstream_id;
680 const char *additional_log_text;
683 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
684 struct Packet *pktin);
685 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
686 struct Packet *pktin);
687 static void ssh2_bare_connection_protocol(Ssh ssh, void *vin, int inlen,
688 struct Packet *pktin);
689 static void ssh1_protocol_setup(Ssh ssh);
690 static void ssh2_protocol_setup(Ssh ssh);
691 static void ssh2_bare_connection_protocol_setup(Ssh ssh);
692 static void ssh_size(void *handle, int width, int height);
693 static void ssh_special(void *handle, Telnet_Special);
694 static int ssh2_try_send(struct ssh_channel *c);
695 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
696 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
697 static void ssh2_set_window(struct ssh_channel *c, int newwin);
698 static int ssh_sendbuffer(void *handle);
699 static int ssh_do_close(Ssh ssh, int notify_exit);
700 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
701 static int ssh2_pkt_getbool(struct Packet *pkt);
702 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
703 static void ssh2_timer(void *ctx, unsigned long now);
704 static void do_ssh2_transport(Ssh ssh, void *vin, int inlen,
705 struct Packet *pktin);
706 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin);
708 struct rdpkt1_state_tag {
709 long len, pad, biglen, to_read;
710 unsigned long realcrc, gotcrc;
714 struct Packet *pktin;
717 struct rdpkt2_state_tag {
718 long len, pad, payload, packetlen, maclen;
721 unsigned long incoming_sequence;
722 struct Packet *pktin;
725 struct rdpkt2_bare_state_tag {
729 unsigned long incoming_sequence;
730 struct Packet *pktin;
733 struct queued_handler;
734 struct queued_handler {
736 chandler_fn_t handler;
738 struct queued_handler *next;
742 const struct plug_function_table *fn;
743 /* the above field _must_ be first in the structure */
753 unsigned char session_key[32];
755 int v1_remote_protoflags;
756 int v1_local_protoflags;
757 int agentfwd_enabled;
760 const struct ssh_cipher *cipher;
763 const struct ssh2_cipher *cscipher, *sccipher;
764 void *cs_cipher_ctx, *sc_cipher_ctx;
765 const struct ssh_mac *csmac, *scmac;
766 void *cs_mac_ctx, *sc_mac_ctx;
767 const struct ssh_compress *cscomp, *sccomp;
768 void *cs_comp_ctx, *sc_comp_ctx;
769 const struct ssh_kex *kex;
770 const struct ssh_signkey *hostkey;
771 char *hostkey_str; /* string representation, for easy checking in rekeys */
772 unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN];
773 int v2_session_id_len;
777 int attempting_connshare;
783 int echoing, editing;
787 int ospeed, ispeed; /* temporaries */
788 int term_width, term_height;
790 tree234 *channels; /* indexed by local id */
791 struct ssh_channel *mainchan; /* primary session channel */
792 int ncmode; /* is primary channel direct-tcpip? */
797 tree234 *rportfwds, *portfwds;
801 SSH_STATE_BEFORE_SIZE,
807 int size_needed, eof_needed;
808 int sent_console_eof;
809 int got_pty; /* affects EOF behaviour on main channel */
811 struct Packet **queue;
812 int queuelen, queuesize;
814 unsigned char *deferred_send_data;
815 int deferred_len, deferred_size;
818 * Gross hack: pscp will try to start SFTP but fall back to
819 * scp1 if that fails. This variable is the means by which
820 * scp.c can reach into the SSH code and find out which one it
825 bufchain banner; /* accumulates banners during do_ssh2_authconn */
830 struct X11Display *x11disp;
831 struct X11FakeAuth *x11auth;
832 tree234 *x11authtree;
835 int conn_throttle_count;
838 int v1_stdout_throttling;
839 unsigned long v2_outgoing_sequence;
841 int ssh1_rdpkt_crstate;
842 int ssh2_rdpkt_crstate;
843 int ssh2_bare_rdpkt_crstate;
844 int ssh_gotdata_crstate;
845 int do_ssh1_connection_crstate;
847 void *do_ssh_init_state;
848 void *do_ssh1_login_state;
849 void *do_ssh2_transport_state;
850 void *do_ssh2_authconn_state;
851 void *do_ssh_connection_init_state;
853 struct rdpkt1_state_tag rdpkt1_state;
854 struct rdpkt2_state_tag rdpkt2_state;
855 struct rdpkt2_bare_state_tag rdpkt2_bare_state;
857 /* SSH-1 and SSH-2 use this for different things, but both use it */
858 int protocol_initial_phase_done;
860 void (*protocol) (Ssh ssh, void *vin, int inlen,
862 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
863 int (*do_ssh_init)(Ssh ssh, unsigned char c);
866 * We maintain our own copy of a Conf structure here. That way,
867 * when we're passed a new one for reconfiguration, we can check
868 * the differences and potentially reconfigure port forwardings
869 * etc in mid-session.
874 * Values cached out of conf so as to avoid the tree234 lookup
875 * cost every time they're used.
880 * Dynamically allocated username string created during SSH
881 * login. Stored in here rather than in the coroutine state so
882 * that it'll be reliably freed if we shut down the SSH session
883 * at some unexpected moment.
888 * Used to transfer data back from async callbacks.
890 void *agent_response;
891 int agent_response_len;
895 * The SSH connection can be set as `frozen', meaning we are
896 * not currently accepting incoming data from the network. This
897 * is slightly more serious than setting the _socket_ as
898 * frozen, because we may already have had data passed to us
899 * from the network which we need to delay processing until
900 * after the freeze is lifted, so we also need a bufchain to
904 bufchain queued_incoming_data;
907 * Dispatch table for packet types that we may have to deal
910 handler_fn_t packet_dispatch[256];
913 * Queues of one-off handler functions for success/failure
914 * indications from a request.
916 struct queued_handler *qhead, *qtail;
917 handler_fn_t q_saved_handler1, q_saved_handler2;
920 * This module deals with sending keepalives.
925 * Track incoming and outgoing data sizes and time, for
928 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
929 unsigned long max_data_size;
931 unsigned long next_rekey, last_rekey;
932 char *deferred_rekey_reason; /* points to STATIC string; don't free */
935 * Fully qualified host name, which we need if doing GSSAPI.
941 * GSSAPI libraries for this session.
943 struct ssh_gss_liblist *gsslibs;
947 #define logevent(s) logevent(ssh->frontend, s)
949 /* logevent, only printf-formatted. */
950 static void logeventf(Ssh ssh, const char *fmt, ...)
956 buf = dupvprintf(fmt, ap);
962 static void bomb_out(Ssh ssh, char *text)
964 ssh_do_close(ssh, FALSE);
966 connection_fatal(ssh->frontend, "%s", text);
970 #define bombout(msg) bomb_out(ssh, dupprintf msg)
972 /* Helper function for common bits of parsing ttymodes. */
973 static void parse_ttymodes(Ssh ssh,
974 void (*do_mode)(void *data, char *mode, char *val),
979 for (val = conf_get_str_strs(ssh->conf, CONF_ttymodes, NULL, &key);
981 val = conf_get_str_strs(ssh->conf, CONF_ttymodes, key, &key)) {
983 * val[0] is either 'V', indicating that an explicit value
984 * follows it, or 'A' indicating that we should pass the
985 * value through from the local environment via get_ttymode.
988 val = get_ttymode(ssh->frontend, key);
990 do_mode(data, key, val);
994 do_mode(data, key, val + 1); /* skip the 'V' */
998 static int ssh_channelcmp(void *av, void *bv)
1000 struct ssh_channel *a = (struct ssh_channel *) av;
1001 struct ssh_channel *b = (struct ssh_channel *) bv;
1002 if (a->localid < b->localid)
1004 if (a->localid > b->localid)
1008 static int ssh_channelfind(void *av, void *bv)
1010 unsigned *a = (unsigned *) av;
1011 struct ssh_channel *b = (struct ssh_channel *) bv;
1012 if (*a < b->localid)
1014 if (*a > b->localid)
1019 static int ssh_rportcmp_ssh1(void *av, void *bv)
1021 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1022 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1024 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
1025 return i < 0 ? -1 : +1;
1026 if (a->dport > b->dport)
1028 if (a->dport < b->dport)
1033 static int ssh_rportcmp_ssh2(void *av, void *bv)
1035 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1036 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1038 if ( (i = strcmp(a->shost, b->shost)) != 0)
1039 return i < 0 ? -1 : +1;
1040 if (a->sport > b->sport)
1042 if (a->sport < b->sport)
1048 * Special form of strcmp which can cope with NULL inputs. NULL is
1049 * defined to sort before even the empty string.
1051 static int nullstrcmp(const char *a, const char *b)
1053 if (a == NULL && b == NULL)
1059 return strcmp(a, b);
1062 static int ssh_portcmp(void *av, void *bv)
1064 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
1065 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
1067 if (a->type > b->type)
1069 if (a->type < b->type)
1071 if (a->addressfamily > b->addressfamily)
1073 if (a->addressfamily < b->addressfamily)
1075 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
1076 return i < 0 ? -1 : +1;
1077 if (a->sport > b->sport)
1079 if (a->sport < b->sport)
1081 if (a->type != 'D') {
1082 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
1083 return i < 0 ? -1 : +1;
1084 if (a->dport > b->dport)
1086 if (a->dport < b->dport)
1092 static int alloc_channel_id(Ssh ssh)
1094 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1095 unsigned low, high, mid;
1097 struct ssh_channel *c;
1100 * First-fit allocation of channel numbers: always pick the
1101 * lowest unused one. To do this, binary-search using the
1102 * counted B-tree to find the largest channel ID which is in a
1103 * contiguous sequence from the beginning. (Precisely
1104 * everything in that sequence must have ID equal to its tree
1105 * index plus CHANNEL_NUMBER_OFFSET.)
1107 tsize = count234(ssh->channels);
1111 while (high - low > 1) {
1112 mid = (high + low) / 2;
1113 c = index234(ssh->channels, mid);
1114 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1115 low = mid; /* this one is fine */
1117 high = mid; /* this one is past it */
1120 * Now low points to either -1, or the tree index of the
1121 * largest ID in the initial sequence.
1124 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
1125 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
1127 return low + 1 + CHANNEL_NUMBER_OFFSET;
1130 static void c_write_stderr(int trusted, const char *buf, int len)
1133 for (i = 0; i < len; i++)
1134 if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60)))
1135 fputc(buf[i], stderr);
1138 static void c_write(Ssh ssh, const char *buf, int len)
1140 if (flags & FLAG_STDERR)
1141 c_write_stderr(1, buf, len);
1143 from_backend(ssh->frontend, 1, buf, len);
1146 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
1148 if (flags & FLAG_STDERR)
1149 c_write_stderr(0, buf, len);
1151 from_backend_untrusted(ssh->frontend, buf, len);
1154 static void c_write_str(Ssh ssh, const char *buf)
1156 c_write(ssh, buf, strlen(buf));
1159 static void ssh_free_packet(struct Packet *pkt)
1164 static struct Packet *ssh_new_packet(void)
1166 struct Packet *pkt = snew(struct Packet);
1168 pkt->body = pkt->data = NULL;
1174 static void ssh1_log_incoming_packet(Ssh ssh, struct Packet *pkt)
1177 struct logblank_t blanks[4];
1183 if (ssh->logomitdata &&
1184 (pkt->type == SSH1_SMSG_STDOUT_DATA ||
1185 pkt->type == SSH1_SMSG_STDERR_DATA ||
1186 pkt->type == SSH1_MSG_CHANNEL_DATA)) {
1187 /* "Session data" packets - omit the data string. */
1188 if (pkt->type == SSH1_MSG_CHANNEL_DATA)
1189 ssh_pkt_getuint32(pkt); /* skip channel id */
1190 blanks[nblanks].offset = pkt->savedpos + 4;
1191 blanks[nblanks].type = PKTLOG_OMIT;
1192 ssh_pkt_getstring(pkt, &str, &slen);
1194 blanks[nblanks].len = slen;
1198 log_packet(ssh->logctx, PKT_INCOMING, pkt->type,
1199 ssh1_pkt_type(pkt->type),
1200 pkt->body, pkt->length, nblanks, blanks, NULL,
1204 static void ssh1_log_outgoing_packet(Ssh ssh, struct Packet *pkt)
1207 struct logblank_t blanks[4];
1212 * For outgoing packets, pkt->length represents the length of the
1213 * whole packet starting at pkt->data (including some header), and
1214 * pkt->body refers to the point within that where the log-worthy
1215 * payload begins. However, incoming packets expect pkt->length to
1216 * represent only the payload length (that is, it's measured from
1217 * pkt->body not from pkt->data). Temporarily adjust our outgoing
1218 * packet to conform to the incoming-packet semantics, so that we
1219 * can analyse it with the ssh_pkt_get functions.
1221 pkt->length -= (pkt->body - pkt->data);
1224 if (ssh->logomitdata &&
1225 (pkt->type == SSH1_CMSG_STDIN_DATA ||
1226 pkt->type == SSH1_MSG_CHANNEL_DATA)) {
1227 /* "Session data" packets - omit the data string. */
1228 if (pkt->type == SSH1_MSG_CHANNEL_DATA)
1229 ssh_pkt_getuint32(pkt); /* skip channel id */
1230 blanks[nblanks].offset = pkt->savedpos + 4;
1231 blanks[nblanks].type = PKTLOG_OMIT;
1232 ssh_pkt_getstring(pkt, &str, &slen);
1234 blanks[nblanks].len = slen;
1239 if ((pkt->type == SSH1_CMSG_AUTH_PASSWORD ||
1240 pkt->type == SSH1_CMSG_AUTH_TIS_RESPONSE ||
1241 pkt->type == SSH1_CMSG_AUTH_CCARD_RESPONSE) &&
1242 conf_get_int(ssh->conf, CONF_logomitpass)) {
1243 /* If this is a password or similar packet, blank the password(s). */
1244 blanks[nblanks].offset = 0;
1245 blanks[nblanks].len = pkt->length;
1246 blanks[nblanks].type = PKTLOG_BLANK;
1248 } else if (pkt->type == SSH1_CMSG_X11_REQUEST_FORWARDING &&
1249 conf_get_int(ssh->conf, CONF_logomitpass)) {
1251 * If this is an X forwarding request packet, blank the fake
1254 * Note that while we blank the X authentication data here, we
1255 * don't take any special action to blank the start of an X11
1256 * channel, so using MIT-MAGIC-COOKIE-1 and actually opening
1257 * an X connection without having session blanking enabled is
1258 * likely to leak your cookie into the log.
1261 ssh_pkt_getstring(pkt, &str, &slen);
1262 blanks[nblanks].offset = pkt->savedpos;
1263 blanks[nblanks].type = PKTLOG_BLANK;
1264 ssh_pkt_getstring(pkt, &str, &slen);
1266 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1271 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1272 ssh1_pkt_type(pkt->data[12]),
1273 pkt->body, pkt->length,
1274 nblanks, blanks, NULL, 0, NULL);
1277 * Undo the above adjustment of pkt->length, to put the packet
1278 * back in the state we found it.
1280 pkt->length += (pkt->body - pkt->data);
1284 * Collect incoming data in the incoming packet buffer.
1285 * Decipher and verify the packet when it is completely read.
1286 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1287 * Update the *data and *datalen variables.
1288 * Return a Packet structure when a packet is completed.
1290 static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1292 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
1294 crBegin(ssh->ssh1_rdpkt_crstate);
1296 st->pktin = ssh_new_packet();
1298 st->pktin->type = 0;
1299 st->pktin->length = 0;
1301 for (st->i = st->len = 0; st->i < 4; st->i++) {
1302 while ((*datalen) == 0)
1304 st->len = (st->len << 8) + **data;
1305 (*data)++, (*datalen)--;
1308 st->pad = 8 - (st->len % 8);
1309 st->biglen = st->len + st->pad;
1310 st->pktin->length = st->len - 5;
1312 if (st->biglen < 0) {
1313 bombout(("Extremely large packet length from server suggests"
1314 " data stream corruption"));
1315 ssh_free_packet(st->pktin);
1319 st->pktin->maxlen = st->biglen;
1320 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1322 st->to_read = st->biglen;
1323 st->p = st->pktin->data;
1324 while (st->to_read > 0) {
1325 st->chunk = st->to_read;
1326 while ((*datalen) == 0)
1328 if (st->chunk > (*datalen))
1329 st->chunk = (*datalen);
1330 memcpy(st->p, *data, st->chunk);
1332 *datalen -= st->chunk;
1334 st->to_read -= st->chunk;
1337 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1338 st->biglen, NULL)) {
1339 bombout(("Network attack (CRC compensation) detected!"));
1340 ssh_free_packet(st->pktin);
1345 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1347 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1348 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1349 if (st->gotcrc != st->realcrc) {
1350 bombout(("Incorrect CRC received on packet"));
1351 ssh_free_packet(st->pktin);
1355 st->pktin->body = st->pktin->data + st->pad + 1;
1357 if (ssh->v1_compressing) {
1358 unsigned char *decompblk;
1360 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1361 st->pktin->body - 1, st->pktin->length + 1,
1362 &decompblk, &decomplen)) {
1363 bombout(("Zlib decompression encountered invalid data"));
1364 ssh_free_packet(st->pktin);
1368 if (st->pktin->maxlen < st->pad + decomplen) {
1369 st->pktin->maxlen = st->pad + decomplen;
1370 st->pktin->data = sresize(st->pktin->data,
1371 st->pktin->maxlen + APIEXTRA,
1373 st->pktin->body = st->pktin->data + st->pad + 1;
1376 memcpy(st->pktin->body - 1, decompblk, decomplen);
1378 st->pktin->length = decomplen - 1;
1381 st->pktin->type = st->pktin->body[-1];
1384 * Now pktin->body and pktin->length identify the semantic content
1385 * of the packet, excluding the initial type byte.
1389 ssh1_log_incoming_packet(ssh, st->pktin);
1391 st->pktin->savedpos = 0;
1393 crFinish(st->pktin);
1396 static void ssh2_log_incoming_packet(Ssh ssh, struct Packet *pkt)
1399 struct logblank_t blanks[4];
1405 if (ssh->logomitdata &&
1406 (pkt->type == SSH2_MSG_CHANNEL_DATA ||
1407 pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)) {
1408 /* "Session data" packets - omit the data string. */
1409 ssh_pkt_getuint32(pkt); /* skip channel id */
1410 if (pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)
1411 ssh_pkt_getuint32(pkt); /* skip extended data type */
1412 blanks[nblanks].offset = pkt->savedpos + 4;
1413 blanks[nblanks].type = PKTLOG_OMIT;
1414 ssh_pkt_getstring(pkt, &str, &slen);
1416 blanks[nblanks].len = slen;
1421 log_packet(ssh->logctx, PKT_INCOMING, pkt->type,
1422 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->type),
1423 pkt->body, pkt->length, nblanks, blanks, &pkt->sequence,
1427 static void ssh2_log_outgoing_packet(Ssh ssh, struct Packet *pkt)
1430 struct logblank_t blanks[4];
1435 * For outgoing packets, pkt->length represents the length of the
1436 * whole packet starting at pkt->data (including some header), and
1437 * pkt->body refers to the point within that where the log-worthy
1438 * payload begins. However, incoming packets expect pkt->length to
1439 * represent only the payload length (that is, it's measured from
1440 * pkt->body not from pkt->data). Temporarily adjust our outgoing
1441 * packet to conform to the incoming-packet semantics, so that we
1442 * can analyse it with the ssh_pkt_get functions.
1444 pkt->length -= (pkt->body - pkt->data);
1447 if (ssh->logomitdata &&
1448 (pkt->type == SSH2_MSG_CHANNEL_DATA ||
1449 pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)) {
1450 /* "Session data" packets - omit the data string. */
1451 ssh_pkt_getuint32(pkt); /* skip channel id */
1452 if (pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)
1453 ssh_pkt_getuint32(pkt); /* skip extended data type */
1454 blanks[nblanks].offset = pkt->savedpos + 4;
1455 blanks[nblanks].type = PKTLOG_OMIT;
1456 ssh_pkt_getstring(pkt, &str, &slen);
1458 blanks[nblanks].len = slen;
1463 if (pkt->type == SSH2_MSG_USERAUTH_REQUEST &&
1464 conf_get_int(ssh->conf, CONF_logomitpass)) {
1465 /* If this is a password packet, blank the password(s). */
1467 ssh_pkt_getstring(pkt, &str, &slen);
1468 ssh_pkt_getstring(pkt, &str, &slen);
1469 ssh_pkt_getstring(pkt, &str, &slen);
1470 if (slen == 8 && !memcmp(str, "password", 8)) {
1471 ssh2_pkt_getbool(pkt);
1472 /* Blank the password field. */
1473 blanks[nblanks].offset = pkt->savedpos;
1474 blanks[nblanks].type = PKTLOG_BLANK;
1475 ssh_pkt_getstring(pkt, &str, &slen);
1477 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1479 /* If there's another password field beyond it (change of
1480 * password), blank that too. */
1481 ssh_pkt_getstring(pkt, &str, &slen);
1483 blanks[nblanks-1].len =
1484 pkt->savedpos - blanks[nblanks].offset;
1487 } else if (ssh->pkt_actx == SSH2_PKTCTX_KBDINTER &&
1488 pkt->type == SSH2_MSG_USERAUTH_INFO_RESPONSE &&
1489 conf_get_int(ssh->conf, CONF_logomitpass)) {
1490 /* If this is a keyboard-interactive response packet, blank
1493 ssh_pkt_getuint32(pkt);
1494 blanks[nblanks].offset = pkt->savedpos;
1495 blanks[nblanks].type = PKTLOG_BLANK;
1497 ssh_pkt_getstring(pkt, &str, &slen);
1501 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1503 } else if (pkt->type == SSH2_MSG_CHANNEL_REQUEST &&
1504 conf_get_int(ssh->conf, CONF_logomitpass)) {
1506 * If this is an X forwarding request packet, blank the fake
1509 * Note that while we blank the X authentication data here, we
1510 * don't take any special action to blank the start of an X11
1511 * channel, so using MIT-MAGIC-COOKIE-1 and actually opening
1512 * an X connection without having session blanking enabled is
1513 * likely to leak your cookie into the log.
1516 ssh_pkt_getuint32(pkt);
1517 ssh_pkt_getstring(pkt, &str, &slen);
1518 if (slen == 7 && !memcmp(str, "x11-req", 0)) {
1519 ssh2_pkt_getbool(pkt);
1520 ssh2_pkt_getbool(pkt);
1521 ssh_pkt_getstring(pkt, &str, &slen);
1522 blanks[nblanks].offset = pkt->savedpos;
1523 blanks[nblanks].type = PKTLOG_BLANK;
1524 ssh_pkt_getstring(pkt, &str, &slen);
1526 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1532 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1533 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]),
1534 pkt->body, pkt->length, nblanks, blanks,
1535 &ssh->v2_outgoing_sequence,
1536 pkt->downstream_id, pkt->additional_log_text);
1539 * Undo the above adjustment of pkt->length, to put the packet
1540 * back in the state we found it.
1542 pkt->length += (pkt->body - pkt->data);
1545 static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1547 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1549 crBegin(ssh->ssh2_rdpkt_crstate);
1551 st->pktin = ssh_new_packet();
1553 st->pktin->type = 0;
1554 st->pktin->length = 0;
1556 st->cipherblk = ssh->sccipher->blksize;
1559 if (st->cipherblk < 8)
1561 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1563 if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_IS_CBC) &&
1566 * When dealing with a CBC-mode cipher, we want to avoid the
1567 * possibility of an attacker's tweaking the ciphertext stream
1568 * so as to cause us to feed the same block to the block
1569 * cipher more than once and thus leak information
1570 * (VU#958563). The way we do this is not to take any
1571 * decisions on the basis of anything we've decrypted until
1572 * we've verified it with a MAC. That includes the packet
1573 * length, so we just read data and check the MAC repeatedly,
1574 * and when the MAC passes, see if the length we've got is
1578 /* May as well allocate the whole lot now. */
1579 st->pktin->data = snewn(OUR_V2_PACKETLIMIT + st->maclen + APIEXTRA,
1582 /* Read an amount corresponding to the MAC. */
1583 for (st->i = 0; st->i < st->maclen; st->i++) {
1584 while ((*datalen) == 0)
1586 st->pktin->data[st->i] = *(*data)++;
1592 unsigned char seq[4];
1593 ssh->scmac->start(ssh->sc_mac_ctx);
1594 PUT_32BIT(seq, st->incoming_sequence);
1595 ssh->scmac->bytes(ssh->sc_mac_ctx, seq, 4);
1598 for (;;) { /* Once around this loop per cipher block. */
1599 /* Read another cipher-block's worth, and tack it onto the end. */
1600 for (st->i = 0; st->i < st->cipherblk; st->i++) {
1601 while ((*datalen) == 0)
1603 st->pktin->data[st->packetlen+st->maclen+st->i] = *(*data)++;
1606 /* Decrypt one more block (a little further back in the stream). */
1607 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1608 st->pktin->data + st->packetlen,
1610 /* Feed that block to the MAC. */
1611 ssh->scmac->bytes(ssh->sc_mac_ctx,
1612 st->pktin->data + st->packetlen, st->cipherblk);
1613 st->packetlen += st->cipherblk;
1614 /* See if that gives us a valid packet. */
1615 if (ssh->scmac->verresult(ssh->sc_mac_ctx,
1616 st->pktin->data + st->packetlen) &&
1617 ((st->len = toint(GET_32BIT(st->pktin->data))) ==
1620 if (st->packetlen >= OUR_V2_PACKETLIMIT) {
1621 bombout(("No valid incoming packet found"));
1622 ssh_free_packet(st->pktin);
1626 st->pktin->maxlen = st->packetlen + st->maclen;
1627 st->pktin->data = sresize(st->pktin->data,
1628 st->pktin->maxlen + APIEXTRA,
1631 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1634 * Acquire and decrypt the first block of the packet. This will
1635 * contain the length and padding details.
1637 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1638 while ((*datalen) == 0)
1640 st->pktin->data[st->i] = *(*data)++;
1645 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1646 st->pktin->data, st->cipherblk);
1649 * Now get the length figure.
1651 st->len = toint(GET_32BIT(st->pktin->data));
1654 * _Completely_ silly lengths should be stomped on before they
1655 * do us any more damage.
1657 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1658 (st->len + 4) % st->cipherblk != 0) {
1659 bombout(("Incoming packet was garbled on decryption"));
1660 ssh_free_packet(st->pktin);
1665 * So now we can work out the total packet length.
1667 st->packetlen = st->len + 4;
1670 * Allocate memory for the rest of the packet.
1672 st->pktin->maxlen = st->packetlen + st->maclen;
1673 st->pktin->data = sresize(st->pktin->data,
1674 st->pktin->maxlen + APIEXTRA,
1678 * Read and decrypt the remainder of the packet.
1680 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1682 while ((*datalen) == 0)
1684 st->pktin->data[st->i] = *(*data)++;
1687 /* Decrypt everything _except_ the MAC. */
1689 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1690 st->pktin->data + st->cipherblk,
1691 st->packetlen - st->cipherblk);
1697 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1698 st->len + 4, st->incoming_sequence)) {
1699 bombout(("Incorrect MAC received on packet"));
1700 ssh_free_packet(st->pktin);
1704 /* Get and sanity-check the amount of random padding. */
1705 st->pad = st->pktin->data[4];
1706 if (st->pad < 4 || st->len - st->pad < 1) {
1707 bombout(("Invalid padding length on received packet"));
1708 ssh_free_packet(st->pktin);
1712 * This enables us to deduce the payload length.
1714 st->payload = st->len - st->pad - 1;
1716 st->pktin->length = st->payload + 5;
1717 st->pktin->encrypted_len = st->packetlen;
1719 st->pktin->sequence = st->incoming_sequence++;
1721 st->pktin->length = st->packetlen - st->pad;
1722 assert(st->pktin->length >= 0);
1725 * Decompress packet payload.
1728 unsigned char *newpayload;
1731 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1732 st->pktin->data + 5, st->pktin->length - 5,
1733 &newpayload, &newlen)) {
1734 if (st->pktin->maxlen < newlen + 5) {
1735 st->pktin->maxlen = newlen + 5;
1736 st->pktin->data = sresize(st->pktin->data,
1737 st->pktin->maxlen + APIEXTRA,
1740 st->pktin->length = 5 + newlen;
1741 memcpy(st->pktin->data + 5, newpayload, newlen);
1747 * pktin->body and pktin->length should identify the semantic
1748 * content of the packet, excluding the initial type byte.
1750 st->pktin->type = st->pktin->data[5];
1751 st->pktin->body = st->pktin->data + 6;
1752 st->pktin->length -= 6;
1753 assert(st->pktin->length >= 0); /* one last double-check */
1756 ssh2_log_incoming_packet(ssh, st->pktin);
1758 st->pktin->savedpos = 0;
1760 crFinish(st->pktin);
1763 static struct Packet *ssh2_bare_connection_rdpkt(Ssh ssh, unsigned char **data,
1766 struct rdpkt2_bare_state_tag *st = &ssh->rdpkt2_bare_state;
1768 crBegin(ssh->ssh2_bare_rdpkt_crstate);
1771 * Read the packet length field.
1773 for (st->i = 0; st->i < 4; st->i++) {
1774 while ((*datalen) == 0)
1776 st->length[st->i] = *(*data)++;
1780 st->packetlen = toint(GET_32BIT_MSB_FIRST(st->length));
1781 if (st->packetlen <= 0 || st->packetlen >= OUR_V2_PACKETLIMIT) {
1782 bombout(("Invalid packet length received"));
1786 st->pktin = ssh_new_packet();
1787 st->pktin->data = snewn(st->packetlen, unsigned char);
1789 st->pktin->encrypted_len = st->packetlen;
1791 st->pktin->sequence = st->incoming_sequence++;
1794 * Read the remainder of the packet.
1796 for (st->i = 0; st->i < st->packetlen; st->i++) {
1797 while ((*datalen) == 0)
1799 st->pktin->data[st->i] = *(*data)++;
1804 * pktin->body and pktin->length should identify the semantic
1805 * content of the packet, excluding the initial type byte.
1807 st->pktin->type = st->pktin->data[0];
1808 st->pktin->body = st->pktin->data + 1;
1809 st->pktin->length = st->packetlen - 1;
1812 * Log incoming packet, possibly omitting sensitive fields.
1815 ssh2_log_incoming_packet(ssh, st->pktin);
1817 st->pktin->savedpos = 0;
1819 crFinish(st->pktin);
1822 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1824 int pad, biglen, i, pktoffs;
1828 * XXX various versions of SC (including 8.8.4) screw up the
1829 * register allocation in this function and use the same register
1830 * (D6) for len and as a temporary, with predictable results. The
1831 * following sledgehammer prevents this.
1838 ssh1_log_outgoing_packet(ssh, pkt);
1840 if (ssh->v1_compressing) {
1841 unsigned char *compblk;
1843 zlib_compress_block(ssh->cs_comp_ctx,
1844 pkt->data + 12, pkt->length - 12,
1845 &compblk, &complen);
1846 ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */
1847 memcpy(pkt->data + 12, compblk, complen);
1849 pkt->length = complen + 12;
1852 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1854 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
1855 pad = 8 - (len % 8);
1857 biglen = len + pad; /* len(padding+type+data+CRC) */
1859 for (i = pktoffs; i < 4+8; i++)
1860 pkt->data[i] = random_byte();
1861 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1862 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1863 PUT_32BIT(pkt->data + pktoffs, len);
1866 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1867 pkt->data + pktoffs + 4, biglen);
1869 if (offset_p) *offset_p = pktoffs;
1870 return biglen + 4; /* len(length+padding+type+data+CRC) */
1873 static int s_write(Ssh ssh, void *data, int len)
1876 log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len,
1877 0, NULL, NULL, 0, NULL);
1880 return sk_write(ssh->s, (char *)data, len);
1883 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1885 int len, backlog, offset;
1886 len = s_wrpkt_prepare(ssh, pkt, &offset);
1887 backlog = s_write(ssh, pkt->data + offset, len);
1888 if (backlog > SSH_MAX_BACKLOG)
1889 ssh_throttle_all(ssh, 1, backlog);
1890 ssh_free_packet(pkt);
1893 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1896 len = s_wrpkt_prepare(ssh, pkt, &offset);
1897 if (ssh->deferred_len + len > ssh->deferred_size) {
1898 ssh->deferred_size = ssh->deferred_len + len + 128;
1899 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1903 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1904 pkt->data + offset, len);
1905 ssh->deferred_len += len;
1906 ssh_free_packet(pkt);
1910 * Construct a SSH-1 packet with the specified contents.
1911 * (This all-at-once interface used to be the only one, but now SSH-1
1912 * packets can also be constructed incrementally.)
1914 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
1920 pkt = ssh1_pkt_init(pkttype);
1922 while ((argtype = va_arg(ap, int)) != PKT_END) {
1923 unsigned char *argp, argchar;
1925 unsigned long argint;
1928 /* Actual fields in the packet */
1930 argint = va_arg(ap, int);
1931 ssh_pkt_adduint32(pkt, argint);
1934 argchar = (unsigned char) va_arg(ap, int);
1935 ssh_pkt_addbyte(pkt, argchar);
1938 argp = va_arg(ap, unsigned char *);
1939 arglen = va_arg(ap, int);
1940 ssh_pkt_adddata(pkt, argp, arglen);
1943 sargp = va_arg(ap, char *);
1944 ssh_pkt_addstring(pkt, sargp);
1947 bn = va_arg(ap, Bignum);
1948 ssh1_pkt_addmp(pkt, bn);
1956 static void send_packet(Ssh ssh, int pkttype, ...)
1960 va_start(ap, pkttype);
1961 pkt = construct_packet(ssh, pkttype, ap);
1966 static void defer_packet(Ssh ssh, int pkttype, ...)
1970 va_start(ap, pkttype);
1971 pkt = construct_packet(ssh, pkttype, ap);
1973 s_wrpkt_defer(ssh, pkt);
1976 static int ssh_versioncmp(char *a, char *b)
1979 unsigned long av, bv;
1981 av = strtoul(a, &ae, 10);
1982 bv = strtoul(b, &be, 10);
1984 return (av < bv ? -1 : +1);
1989 av = strtoul(ae, &ae, 10);
1990 bv = strtoul(be, &be, 10);
1992 return (av < bv ? -1 : +1);
1997 * Utility routines for putting an SSH-protocol `string' and
1998 * `uint32' into a hash state.
2000 static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
2002 unsigned char lenblk[4];
2003 PUT_32BIT(lenblk, len);
2004 h->bytes(s, lenblk, 4);
2005 h->bytes(s, str, len);
2008 static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
2010 unsigned char intblk[4];
2011 PUT_32BIT(intblk, i);
2012 h->bytes(s, intblk, 4);
2016 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
2018 static void ssh_pkt_ensure(struct Packet *pkt, int length)
2020 if (pkt->maxlen < length) {
2021 unsigned char *body = pkt->body;
2022 int offset = body ? body - pkt->data : 0;
2023 pkt->maxlen = length + 256;
2024 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
2025 if (body) pkt->body = pkt->data + offset;
2028 static void ssh_pkt_adddata(struct Packet *pkt, const void *data, int len)
2031 ssh_pkt_ensure(pkt, pkt->length);
2032 memcpy(pkt->data + pkt->length - len, data, len);
2034 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
2036 ssh_pkt_adddata(pkt, &byte, 1);
2038 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
2040 ssh_pkt_adddata(pkt, &value, 1);
2042 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
2045 PUT_32BIT(x, value);
2046 ssh_pkt_adddata(pkt, x, 4);
2048 static void ssh_pkt_addstring_start(struct Packet *pkt)
2050 ssh_pkt_adduint32(pkt, 0);
2051 pkt->savedpos = pkt->length;
2053 static void ssh_pkt_addstring_str(struct Packet *pkt, const char *data)
2055 ssh_pkt_adddata(pkt, data, strlen(data));
2056 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
2058 static void ssh_pkt_addstring_data(struct Packet *pkt, const char *data,
2061 ssh_pkt_adddata(pkt, data, len);
2062 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
2064 static void ssh_pkt_addstring(struct Packet *pkt, const char *data)
2066 ssh_pkt_addstring_start(pkt);
2067 ssh_pkt_addstring_str(pkt, data);
2069 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
2071 int len = ssh1_bignum_length(b);
2072 unsigned char *data = snewn(len, unsigned char);
2073 (void) ssh1_write_bignum(data, b);
2074 ssh_pkt_adddata(pkt, data, len);
2077 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
2080 int i, n = (bignum_bitcount(b) + 7) / 8;
2081 p = snewn(n + 1, unsigned char);
2083 for (i = 1; i <= n; i++)
2084 p[i] = bignum_byte(b, n - i);
2086 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
2088 memmove(p, p + i, n + 1 - i);
2092 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
2096 p = ssh2_mpint_fmt(b, &len);
2097 ssh_pkt_addstring_start(pkt);
2098 ssh_pkt_addstring_data(pkt, (char *)p, len);
2102 static struct Packet *ssh1_pkt_init(int pkt_type)
2104 struct Packet *pkt = ssh_new_packet();
2105 pkt->length = 4 + 8; /* space for length + max padding */
2106 ssh_pkt_addbyte(pkt, pkt_type);
2107 pkt->body = pkt->data + pkt->length;
2108 pkt->type = pkt_type;
2109 pkt->downstream_id = 0;
2110 pkt->additional_log_text = NULL;
2114 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
2115 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
2116 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
2117 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
2118 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
2119 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
2120 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
2121 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
2122 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
2124 static struct Packet *ssh2_pkt_init(int pkt_type)
2126 struct Packet *pkt = ssh_new_packet();
2127 pkt->length = 5; /* space for packet length + padding length */
2129 pkt->type = pkt_type;
2130 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
2131 pkt->body = pkt->data + pkt->length; /* after packet type */
2132 pkt->downstream_id = 0;
2133 pkt->additional_log_text = NULL;
2138 * Construct an SSH-2 final-form packet: compress it, encrypt it,
2139 * put the MAC on it. Final packet, ready to be sent, is stored in
2140 * pkt->data. Total length is returned.
2142 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
2144 int cipherblk, maclen, padding, i;
2147 ssh2_log_outgoing_packet(ssh, pkt);
2149 if (ssh->bare_connection) {
2151 * Trivial packet construction for the bare connection
2154 PUT_32BIT(pkt->data + 1, pkt->length - 5);
2155 pkt->body = pkt->data + 1;
2156 ssh->v2_outgoing_sequence++; /* only for diagnostics, really */
2157 return pkt->length - 1;
2161 * Compress packet payload.
2164 unsigned char *newpayload;
2167 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
2169 &newpayload, &newlen)) {
2171 ssh2_pkt_adddata(pkt, newpayload, newlen);
2177 * Add padding. At least four bytes, and must also bring total
2178 * length (minus MAC) up to a multiple of the block size.
2179 * If pkt->forcepad is set, make sure the packet is at least that size
2182 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
2183 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
2185 if (pkt->length + padding < pkt->forcepad)
2186 padding = pkt->forcepad - pkt->length;
2188 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
2189 assert(padding <= 255);
2190 maclen = ssh->csmac ? ssh->csmac->len : 0;
2191 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
2192 pkt->data[4] = padding;
2193 for (i = 0; i < padding; i++)
2194 pkt->data[pkt->length + i] = random_byte();
2195 PUT_32BIT(pkt->data, pkt->length + padding - 4);
2197 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
2198 pkt->length + padding,
2199 ssh->v2_outgoing_sequence);
2200 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
2203 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
2204 pkt->data, pkt->length + padding);
2206 pkt->encrypted_len = pkt->length + padding;
2208 /* Ready-to-send packet starts at pkt->data. We return length. */
2209 pkt->body = pkt->data;
2210 return pkt->length + padding + maclen;
2214 * Routines called from the main SSH code to send packets. There
2215 * are quite a few of these, because we have two separate
2216 * mechanisms for delaying the sending of packets:
2218 * - In order to send an IGNORE message and a password message in
2219 * a single fixed-length blob, we require the ability to
2220 * concatenate the encrypted forms of those two packets _into_ a
2221 * single blob and then pass it to our <network.h> transport
2222 * layer in one go. Hence, there's a deferment mechanism which
2223 * works after packet encryption.
2225 * - In order to avoid sending any connection-layer messages
2226 * during repeat key exchange, we have to queue up any such
2227 * outgoing messages _before_ they are encrypted (and in
2228 * particular before they're allocated sequence numbers), and
2229 * then send them once we've finished.
2231 * I call these mechanisms `defer' and `queue' respectively, so as
2232 * to distinguish them reasonably easily.
2234 * The functions send_noqueue() and defer_noqueue() free the packet
2235 * structure they are passed. Every outgoing packet goes through
2236 * precisely one of these functions in its life; packets passed to
2237 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
2238 * these or get queued, and then when the queue is later emptied
2239 * the packets are all passed to defer_noqueue().
2241 * When using a CBC-mode cipher, it's necessary to ensure that an
2242 * attacker can't provide data to be encrypted using an IV that they
2243 * know. We ensure this by prefixing each packet that might contain
2244 * user data with an SSH_MSG_IGNORE. This is done using the deferral
2245 * mechanism, so in this case send_noqueue() ends up redirecting to
2246 * defer_noqueue(). If you don't like this inefficiency, don't use
2250 static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
2251 static void ssh_pkt_defersend(Ssh);
2254 * Send an SSH-2 packet immediately, without queuing or deferring.
2256 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
2260 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
2261 /* We need to send two packets, so use the deferral mechanism. */
2262 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2263 ssh_pkt_defersend(ssh);
2266 len = ssh2_pkt_construct(ssh, pkt);
2267 backlog = s_write(ssh, pkt->body, len);
2268 if (backlog > SSH_MAX_BACKLOG)
2269 ssh_throttle_all(ssh, 1, backlog);
2271 ssh->outgoing_data_size += pkt->encrypted_len;
2272 if (!ssh->kex_in_progress &&
2273 !ssh->bare_connection &&
2274 ssh->max_data_size != 0 &&
2275 ssh->outgoing_data_size > ssh->max_data_size)
2276 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2278 ssh_free_packet(pkt);
2282 * Defer an SSH-2 packet.
2284 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
2287 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
2288 ssh->deferred_len == 0 && !noignore &&
2289 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2291 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2292 * get encrypted with a known IV.
2294 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2295 ssh2_pkt_addstring_start(ipkt);
2296 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
2298 len = ssh2_pkt_construct(ssh, pkt);
2299 if (ssh->deferred_len + len > ssh->deferred_size) {
2300 ssh->deferred_size = ssh->deferred_len + len + 128;
2301 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2305 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->body, len);
2306 ssh->deferred_len += len;
2307 ssh->deferred_data_size += pkt->encrypted_len;
2308 ssh_free_packet(pkt);
2312 * Queue an SSH-2 packet.
2314 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
2316 assert(ssh->queueing);
2318 if (ssh->queuelen >= ssh->queuesize) {
2319 ssh->queuesize = ssh->queuelen + 32;
2320 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
2323 ssh->queue[ssh->queuelen++] = pkt;
2327 * Either queue or send a packet, depending on whether queueing is
2330 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
2333 ssh2_pkt_queue(ssh, pkt);
2335 ssh2_pkt_send_noqueue(ssh, pkt);
2339 * Either queue or defer a packet, depending on whether queueing is
2342 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
2345 ssh2_pkt_queue(ssh, pkt);
2347 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2351 * Send the whole deferred data block constructed by
2352 * ssh2_pkt_defer() or SSH-1's defer_packet().
2354 * The expected use of the defer mechanism is that you call
2355 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2356 * not currently queueing, this simply sets up deferred_send_data
2357 * and then sends it. If we _are_ currently queueing, the calls to
2358 * ssh2_pkt_defer() put the deferred packets on to the queue
2359 * instead, and therefore ssh_pkt_defersend() has no deferred data
2360 * to send. Hence, there's no need to make it conditional on
2363 static void ssh_pkt_defersend(Ssh ssh)
2366 backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
2367 ssh->deferred_len = ssh->deferred_size = 0;
2368 sfree(ssh->deferred_send_data);
2369 ssh->deferred_send_data = NULL;
2370 if (backlog > SSH_MAX_BACKLOG)
2371 ssh_throttle_all(ssh, 1, backlog);
2373 ssh->outgoing_data_size += ssh->deferred_data_size;
2374 if (!ssh->kex_in_progress &&
2375 !ssh->bare_connection &&
2376 ssh->max_data_size != 0 &&
2377 ssh->outgoing_data_size > ssh->max_data_size)
2378 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2379 ssh->deferred_data_size = 0;
2383 * Send a packet whose length needs to be disguised (typically
2384 * passwords or keyboard-interactive responses).
2386 static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
2392 * The simplest way to do this is to adjust the
2393 * variable-length padding field in the outgoing packet.
2395 * Currently compiled out, because some Cisco SSH servers
2396 * don't like excessively padded packets (bah, why's it
2399 pkt->forcepad = padsize;
2400 ssh2_pkt_send(ssh, pkt);
2405 * If we can't do that, however, an alternative approach is
2406 * to use the pkt_defer mechanism to bundle the packet
2407 * tightly together with an SSH_MSG_IGNORE such that their
2408 * combined length is a constant. So first we construct the
2409 * final form of this packet and defer its sending.
2411 ssh2_pkt_defer(ssh, pkt);
2414 * Now construct an SSH_MSG_IGNORE which includes a string
2415 * that's an exact multiple of the cipher block size. (If
2416 * the cipher is NULL so that the block size is
2417 * unavailable, we don't do this trick at all, because we
2418 * gain nothing by it.)
2420 if (ssh->cscipher &&
2421 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2424 stringlen = (256 - ssh->deferred_len);
2425 stringlen += ssh->cscipher->blksize - 1;
2426 stringlen -= (stringlen % ssh->cscipher->blksize);
2429 * Temporarily disable actual compression, so we
2430 * can guarantee to get this string exactly the
2431 * length we want it. The compression-disabling
2432 * routine should return an integer indicating how
2433 * many bytes we should adjust our string length
2437 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
2439 pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2440 ssh2_pkt_addstring_start(pkt);
2441 for (i = 0; i < stringlen; i++) {
2442 char c = (char) random_byte();
2443 ssh2_pkt_addstring_data(pkt, &c, 1);
2445 ssh2_pkt_defer(ssh, pkt);
2447 ssh_pkt_defersend(ssh);
2452 * Send all queued SSH-2 packets. We send them by means of
2453 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2454 * packets that needed to be lumped together.
2456 static void ssh2_pkt_queuesend(Ssh ssh)
2460 assert(!ssh->queueing);
2462 for (i = 0; i < ssh->queuelen; i++)
2463 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
2466 ssh_pkt_defersend(ssh);
2470 void bndebug(char *string, Bignum b)
2474 p = ssh2_mpint_fmt(b, &len);
2475 debug(("%s", string));
2476 for (i = 0; i < len; i++)
2477 debug((" %02x", p[i]));
2483 static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
2487 p = ssh2_mpint_fmt(b, &len);
2488 hash_string(h, s, p, len);
2493 * Packet decode functions for both SSH-1 and SSH-2.
2495 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
2497 unsigned long value;
2498 if (pkt->length - pkt->savedpos < 4)
2499 return 0; /* arrgh, no way to decline (FIXME?) */
2500 value = GET_32BIT(pkt->body + pkt->savedpos);
2504 static int ssh2_pkt_getbool(struct Packet *pkt)
2506 unsigned long value;
2507 if (pkt->length - pkt->savedpos < 1)
2508 return 0; /* arrgh, no way to decline (FIXME?) */
2509 value = pkt->body[pkt->savedpos] != 0;
2513 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
2518 if (pkt->length - pkt->savedpos < 4)
2520 len = toint(GET_32BIT(pkt->body + pkt->savedpos));
2525 if (pkt->length - pkt->savedpos < *length)
2527 *p = (char *)(pkt->body + pkt->savedpos);
2528 pkt->savedpos += *length;
2530 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
2532 if (pkt->length - pkt->savedpos < length)
2534 pkt->savedpos += length;
2535 return pkt->body + (pkt->savedpos - length);
2537 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2538 unsigned char **keystr)
2542 j = makekey(pkt->body + pkt->savedpos,
2543 pkt->length - pkt->savedpos,
2550 assert(pkt->savedpos < pkt->length);
2554 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2559 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2560 pkt->length - pkt->savedpos, &b);
2568 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2574 ssh_pkt_getstring(pkt, &p, &length);
2579 b = bignum_from_bytes((unsigned char *)p, length);
2584 * Helper function to add an SSH-2 signature blob to a packet.
2585 * Expects to be shown the public key blob as well as the signature
2586 * blob. Normally works just like ssh2_pkt_addstring, but will
2587 * fiddle with the signature packet if necessary for
2588 * BUG_SSH2_RSA_PADDING.
2590 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2591 void *pkblob_v, int pkblob_len,
2592 void *sigblob_v, int sigblob_len)
2594 unsigned char *pkblob = (unsigned char *)pkblob_v;
2595 unsigned char *sigblob = (unsigned char *)sigblob_v;
2597 /* dmemdump(pkblob, pkblob_len); */
2598 /* dmemdump(sigblob, sigblob_len); */
2601 * See if this is in fact an ssh-rsa signature and a buggy
2602 * server; otherwise we can just do this the easy way.
2604 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) && pkblob_len > 4+7+4 &&
2605 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2606 int pos, len, siglen;
2609 * Find the byte length of the modulus.
2612 pos = 4+7; /* skip over "ssh-rsa" */
2613 len = toint(GET_32BIT(pkblob+pos)); /* get length of exponent */
2614 if (len < 0 || len > pkblob_len - pos - 4)
2616 pos += 4 + len; /* skip over exponent */
2617 if (pkblob_len - pos < 4)
2619 len = toint(GET_32BIT(pkblob+pos)); /* find length of modulus */
2620 if (len < 0 || len > pkblob_len - pos - 4)
2622 pos += 4; /* find modulus itself */
2623 while (len > 0 && pkblob[pos] == 0)
2625 /* debug(("modulus length is %d\n", len)); */
2628 * Now find the signature integer.
2630 pos = 4+7; /* skip over "ssh-rsa" */
2631 if (sigblob_len < pos+4)
2633 siglen = toint(GET_32BIT(sigblob+pos));
2634 if (siglen != sigblob_len - pos - 4)
2636 /* debug(("signature length is %d\n", siglen)); */
2638 if (len != siglen) {
2639 unsigned char newlen[4];
2640 ssh2_pkt_addstring_start(pkt);
2641 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2642 /* dmemdump(sigblob, pos); */
2643 pos += 4; /* point to start of actual sig */
2644 PUT_32BIT(newlen, len);
2645 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2646 /* dmemdump(newlen, 4); */
2648 while (len-- > siglen) {
2649 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2650 /* dmemdump(newlen, 1); */
2652 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2653 /* dmemdump(sigblob+pos, siglen); */
2657 /* Otherwise fall through and do it the easy way. We also come
2658 * here as a fallback if we discover above that the key blob
2659 * is misformatted in some way. */
2663 ssh2_pkt_addstring_start(pkt);
2664 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2668 * Examine the remote side's version string and compare it against
2669 * a list of known buggy implementations.
2671 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2673 char *imp; /* pointer to implementation part */
2675 imp += strcspn(imp, "-");
2677 imp += strcspn(imp, "-");
2680 ssh->remote_bugs = 0;
2683 * General notes on server version strings:
2684 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2685 * here -- in particular, we've heard of one that's perfectly happy
2686 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2687 * so we can't distinguish them.
2689 if (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == FORCE_ON ||
2690 (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == AUTO &&
2691 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2692 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2693 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2694 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2696 * These versions don't support SSH1_MSG_IGNORE, so we have
2697 * to use a different defence against password length
2700 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2701 logevent("We believe remote version has SSH-1 ignore bug");
2704 if (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == FORCE_ON ||
2705 (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == AUTO &&
2706 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2708 * These versions need a plain password sent; they can't
2709 * handle having a null and a random length of data after
2712 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2713 logevent("We believe remote version needs a plain SSH-1 password");
2716 if (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == FORCE_ON ||
2717 (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == AUTO &&
2718 (!strcmp(imp, "Cisco-1.25")))) {
2720 * These versions apparently have no clue whatever about
2721 * RSA authentication and will panic and die if they see
2722 * an AUTH_RSA message.
2724 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2725 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2728 if (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == FORCE_ON ||
2729 (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == AUTO &&
2730 !wc_match("* VShell", imp) &&
2731 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2732 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2733 wc_match("2.1 *", imp)))) {
2735 * These versions have the HMAC bug.
2737 ssh->remote_bugs |= BUG_SSH2_HMAC;
2738 logevent("We believe remote version has SSH-2 HMAC bug");
2741 if (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == FORCE_ON ||
2742 (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == AUTO &&
2743 !wc_match("* VShell", imp) &&
2744 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2746 * These versions have the key-derivation bug (failing to
2747 * include the literal shared secret in the hashes that
2748 * generate the keys).
2750 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2751 logevent("We believe remote version has SSH-2 key-derivation bug");
2754 if (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == FORCE_ON ||
2755 (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == AUTO &&
2756 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2757 wc_match("OpenSSH_3.[0-2]*", imp) ||
2758 wc_match("mod_sftp/0.[0-8]*", imp) ||
2759 wc_match("mod_sftp/0.9.[0-8]", imp)))) {
2761 * These versions have the SSH-2 RSA padding bug.
2763 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2764 logevent("We believe remote version has SSH-2 RSA padding bug");
2767 if (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == FORCE_ON ||
2768 (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == AUTO &&
2769 wc_match("OpenSSH_2.[0-2]*", imp))) {
2771 * These versions have the SSH-2 session-ID bug in
2772 * public-key authentication.
2774 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2775 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2778 if (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == FORCE_ON ||
2779 (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == AUTO &&
2780 (wc_match("DigiSSH_2.0", imp) ||
2781 wc_match("OpenSSH_2.[0-4]*", imp) ||
2782 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2783 wc_match("Sun_SSH_1.0", imp) ||
2784 wc_match("Sun_SSH_1.0.1", imp) ||
2785 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2786 wc_match("WeOnlyDo-*", imp)))) {
2788 * These versions have the SSH-2 rekey bug.
2790 ssh->remote_bugs |= BUG_SSH2_REKEY;
2791 logevent("We believe remote version has SSH-2 rekey bug");
2794 if (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == FORCE_ON ||
2795 (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == AUTO &&
2796 (wc_match("1.36_sshlib GlobalSCAPE", imp) ||
2797 wc_match("1.36 sshlib: GlobalScape", imp)))) {
2799 * This version ignores our makpkt and needs to be throttled.
2801 ssh->remote_bugs |= BUG_SSH2_MAXPKT;
2802 logevent("We believe remote version ignores SSH-2 maximum packet size");
2805 if (conf_get_int(ssh->conf, CONF_sshbug_ignore2) == FORCE_ON) {
2807 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2808 * none detected automatically.
2810 ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE;
2811 logevent("We believe remote version has SSH-2 ignore bug");
2814 if (conf_get_int(ssh->conf, CONF_sshbug_winadj) == FORCE_ON) {
2816 * Servers that don't support our winadj request for one
2817 * reason or another. Currently, none detected automatically.
2819 ssh->remote_bugs |= BUG_CHOKES_ON_WINADJ;
2820 logevent("We believe remote version has winadj bug");
2823 if (conf_get_int(ssh->conf, CONF_sshbug_chanreq) == FORCE_ON ||
2824 (conf_get_int(ssh->conf, CONF_sshbug_chanreq) == AUTO &&
2825 (wc_match("OpenSSH_[2-5].*", imp) ||
2826 wc_match("OpenSSH_6.[0-6]*", imp)))) {
2828 * These versions have the SSH-2 channel request bug. 6.7 and
2830 * https://bugzilla.mindrot.org/show_bug.cgi?id=1818
2832 ssh->remote_bugs |= BUG_SENDS_LATE_REQUEST_REPLY;
2833 logevent("We believe remote version has SSH-2 channel request bug");
2838 * The `software version' part of an SSH version string is required
2839 * to contain no spaces or minus signs.
2841 static void ssh_fix_verstring(char *str)
2843 /* Eat "<protoversion>-". */
2844 while (*str && *str != '-') str++;
2845 assert(*str == '-'); str++;
2847 /* Convert minus signs and spaces in the remaining string into
2850 if (*str == '-' || *str == ' ')
2857 * Send an appropriate SSH version string.
2859 static void ssh_send_verstring(Ssh ssh, const char *protoname, char *svers)
2863 if (ssh->version == 2) {
2865 * Construct a v2 version string.
2867 verstring = dupprintf("%s2.0-%s\015\012", protoname, sshver);
2870 * Construct a v1 version string.
2872 assert(!strcmp(protoname, "SSH-")); /* no v1 bare connection protocol */
2873 verstring = dupprintf("SSH-%s-%s\012",
2874 (ssh_versioncmp(svers, "1.5") <= 0 ?
2879 ssh_fix_verstring(verstring + strlen(protoname));
2881 if (ssh->version == 2) {
2884 * Record our version string.
2886 len = strcspn(verstring, "\015\012");
2887 ssh->v_c = snewn(len + 1, char);
2888 memcpy(ssh->v_c, verstring, len);
2892 logeventf(ssh, "We claim version: %.*s",
2893 strcspn(verstring, "\015\012"), verstring);
2894 s_write(ssh, verstring, strlen(verstring));
2898 static int do_ssh_init(Ssh ssh, unsigned char c)
2900 static const char protoname[] = "SSH-";
2902 struct do_ssh_init_state {
2911 crState(do_ssh_init_state);
2915 /* Search for a line beginning with the protocol name prefix in
2918 for (s->i = 0; protoname[s->i]; s->i++) {
2919 if ((char)c != protoname[s->i]) goto no;
2929 s->vstrsize = sizeof(protoname) + 16;
2930 s->vstring = snewn(s->vstrsize, char);
2931 strcpy(s->vstring, protoname);
2932 s->vslen = strlen(protoname);
2935 if (s->vslen >= s->vstrsize - 1) {
2937 s->vstring = sresize(s->vstring, s->vstrsize, char);
2939 s->vstring[s->vslen++] = c;
2942 s->version[s->i] = '\0';
2944 } else if (s->i < sizeof(s->version) - 1)
2945 s->version[s->i++] = c;
2946 } else if (c == '\012')
2948 crReturn(1); /* get another char */
2951 ssh->agentfwd_enabled = FALSE;
2952 ssh->rdpkt2_state.incoming_sequence = 0;
2954 s->vstring[s->vslen] = 0;
2955 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2956 logeventf(ssh, "Server version: %s", s->vstring);
2957 ssh_detect_bugs(ssh, s->vstring);
2960 * Decide which SSH protocol version to support.
2963 /* Anything strictly below "2.0" means protocol 1 is supported. */
2964 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2965 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2966 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2968 if (conf_get_int(ssh->conf, CONF_sshprot) == 0 && !s->proto1) {
2969 bombout(("SSH protocol version 1 required by configuration but "
2970 "not provided by server"));
2973 if (conf_get_int(ssh->conf, CONF_sshprot) == 3 && !s->proto2) {
2974 bombout(("SSH protocol version 2 required by configuration but "
2975 "not provided by server"));
2979 if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1))
2984 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2986 /* Send the version string, if we haven't already */
2987 if (conf_get_int(ssh->conf, CONF_sshprot) != 3)
2988 ssh_send_verstring(ssh, protoname, s->version);
2990 if (ssh->version == 2) {
2993 * Record their version string.
2995 len = strcspn(s->vstring, "\015\012");
2996 ssh->v_s = snewn(len + 1, char);
2997 memcpy(ssh->v_s, s->vstring, len);
3001 * Initialise SSH-2 protocol.
3003 ssh->protocol = ssh2_protocol;
3004 ssh2_protocol_setup(ssh);
3005 ssh->s_rdpkt = ssh2_rdpkt;
3008 * Initialise SSH-1 protocol.
3010 ssh->protocol = ssh1_protocol;
3011 ssh1_protocol_setup(ssh);
3012 ssh->s_rdpkt = ssh1_rdpkt;
3014 if (ssh->version == 2)
3015 do_ssh2_transport(ssh, NULL, -1, NULL);
3017 update_specials_menu(ssh->frontend);
3018 ssh->state = SSH_STATE_BEFORE_SIZE;
3019 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3026 static int do_ssh_connection_init(Ssh ssh, unsigned char c)
3029 * Ordinary SSH begins with the banner "SSH-x.y-...". This is just
3030 * the ssh-connection part, extracted and given a trivial binary
3031 * packet protocol, so we replace 'SSH-' at the start with a new
3032 * name. In proper SSH style (though of course this part of the
3033 * proper SSH protocol _isn't_ subject to this kind of
3034 * DNS-domain-based extension), we define the new name in our
3037 static const char protoname[] =
3038 "SSHCONNECTION@putty.projects.tartarus.org-";
3040 struct do_ssh_connection_init_state {
3048 crState(do_ssh_connection_init_state);
3052 /* Search for a line beginning with the protocol name prefix in
3055 for (s->i = 0; protoname[s->i]; s->i++) {
3056 if ((char)c != protoname[s->i]) goto no;
3066 s->vstrsize = sizeof(protoname) + 16;
3067 s->vstring = snewn(s->vstrsize, char);
3068 strcpy(s->vstring, protoname);
3069 s->vslen = strlen(protoname);
3072 if (s->vslen >= s->vstrsize - 1) {
3074 s->vstring = sresize(s->vstring, s->vstrsize, char);
3076 s->vstring[s->vslen++] = c;
3079 s->version[s->i] = '\0';
3081 } else if (s->i < sizeof(s->version) - 1)
3082 s->version[s->i++] = c;
3083 } else if (c == '\012')
3085 crReturn(1); /* get another char */
3088 ssh->agentfwd_enabled = FALSE;
3089 ssh->rdpkt2_bare_state.incoming_sequence = 0;
3091 s->vstring[s->vslen] = 0;
3092 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
3093 logeventf(ssh, "Server version: %s", s->vstring);
3094 ssh_detect_bugs(ssh, s->vstring);
3097 * Decide which SSH protocol version to support. This is easy in
3098 * bare ssh-connection mode: only 2.0 is legal.
3100 if (ssh_versioncmp(s->version, "2.0") < 0) {
3101 bombout(("Server announces compatibility with SSH-1 in bare ssh-connection protocol"));
3104 if (conf_get_int(ssh->conf, CONF_sshprot) == 0) {
3105 bombout(("Bare ssh-connection protocol cannot be run in SSH-1-only mode"));
3111 logeventf(ssh, "Using bare ssh-connection protocol");
3113 /* Send the version string, if we haven't already */
3114 ssh_send_verstring(ssh, protoname, s->version);
3117 * Initialise bare connection protocol.
3119 ssh->protocol = ssh2_bare_connection_protocol;
3120 ssh2_bare_connection_protocol_setup(ssh);
3121 ssh->s_rdpkt = ssh2_bare_connection_rdpkt;
3123 update_specials_menu(ssh->frontend);
3124 ssh->state = SSH_STATE_BEFORE_SIZE;
3125 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3128 * Get authconn (really just conn) under way.
3130 do_ssh2_authconn(ssh, NULL, 0, NULL);
3137 static void ssh_process_incoming_data(Ssh ssh,
3138 unsigned char **data, int *datalen)
3140 struct Packet *pktin;
3142 pktin = ssh->s_rdpkt(ssh, data, datalen);
3144 ssh->protocol(ssh, NULL, 0, pktin);
3145 ssh_free_packet(pktin);
3149 static void ssh_queue_incoming_data(Ssh ssh,
3150 unsigned char **data, int *datalen)
3152 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
3157 static void ssh_process_queued_incoming_data(Ssh ssh)
3160 unsigned char *data;
3163 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
3164 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
3168 while (!ssh->frozen && len > 0)
3169 ssh_process_incoming_data(ssh, &data, &len);
3172 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
3176 static void ssh_set_frozen(Ssh ssh, int frozen)
3179 sk_set_frozen(ssh->s, frozen);
3180 ssh->frozen = frozen;
3183 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
3185 /* Log raw data, if we're in that mode. */
3187 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
3188 0, NULL, NULL, 0, NULL);
3190 crBegin(ssh->ssh_gotdata_crstate);
3193 * To begin with, feed the characters one by one to the
3194 * protocol initialisation / selection function do_ssh_init().
3195 * When that returns 0, we're done with the initial greeting
3196 * exchange and can move on to packet discipline.
3199 int ret; /* need not be kept across crReturn */
3201 crReturnV; /* more data please */
3202 ret = ssh->do_ssh_init(ssh, *data);
3210 * We emerge from that loop when the initial negotiation is
3211 * over and we have selected an s_rdpkt function. Now pass
3212 * everything to s_rdpkt, and then pass the resulting packets
3213 * to the proper protocol handler.
3217 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
3219 ssh_queue_incoming_data(ssh, &data, &datalen);
3220 /* This uses up all data and cannot cause anything interesting
3221 * to happen; indeed, for anything to happen at all, we must
3222 * return, so break out. */
3224 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
3225 /* This uses up some or all data, and may freeze the
3227 ssh_process_queued_incoming_data(ssh);
3229 /* This uses up some or all data, and may freeze the
3231 ssh_process_incoming_data(ssh, &data, &datalen);
3233 /* FIXME this is probably EBW. */
3234 if (ssh->state == SSH_STATE_CLOSED)
3237 /* We're out of data. Go and get some more. */
3243 static int ssh_do_close(Ssh ssh, int notify_exit)
3246 struct ssh_channel *c;
3248 ssh->state = SSH_STATE_CLOSED;
3249 expire_timer_context(ssh);
3254 notify_remote_exit(ssh->frontend);
3259 * Now we must shut down any port- and X-forwarded channels going
3260 * through this connection.
3262 if (ssh->channels) {
3263 while (NULL != (c = index234(ssh->channels, 0))) {
3266 x11_close(c->u.x11.xconn);
3269 case CHAN_SOCKDATA_DORMANT:
3270 pfd_close(c->u.pfd.pf);
3273 del234(ssh->channels, c); /* moving next one to index 0 */
3274 if (ssh->version == 2)
3275 bufchain_clear(&c->v.v2.outbuffer);
3280 * Go through port-forwardings, and close any associated
3281 * listening sockets.
3283 if (ssh->portfwds) {
3284 struct ssh_portfwd *pf;
3285 while (NULL != (pf = index234(ssh->portfwds, 0))) {
3286 /* Dispose of any listening socket. */
3288 pfl_terminate(pf->local);
3289 del234(ssh->portfwds, pf); /* moving next one to index 0 */
3292 freetree234(ssh->portfwds);
3293 ssh->portfwds = NULL;
3299 static void ssh_socket_log(Plug plug, int type, SockAddr addr, int port,
3300 const char *error_msg, int error_code)
3302 Ssh ssh = (Ssh) plug;
3303 char addrbuf[256], *msg;
3305 if (ssh->attempting_connshare) {
3307 * While we're attempting connection sharing, don't loudly log
3308 * everything that happens. Real TCP connections need to be
3309 * logged when we _start_ trying to connect, because it might
3310 * be ages before they respond if something goes wrong; but
3311 * connection sharing is local and quick to respond, and it's
3312 * sufficient to simply wait and see whether it worked
3316 sk_getaddr(addr, addrbuf, lenof(addrbuf));
3319 if (sk_addr_needs_port(addr)) {
3320 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
3322 msg = dupprintf("Connecting to %s", addrbuf);
3325 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
3333 void ssh_connshare_log(Ssh ssh, int event, const char *logtext,
3334 const char *ds_err, const char *us_err)
3336 if (event == SHARE_NONE) {
3337 /* In this case, 'logtext' is an error message indicating a
3338 * reason why connection sharing couldn't be set up _at all_.
3339 * Failing that, ds_err and us_err indicate why we couldn't be
3340 * a downstream and an upstream respectively. */
3342 logeventf(ssh, "Could not set up connection sharing: %s", logtext);
3345 logeventf(ssh, "Could not set up connection sharing"
3346 " as downstream: %s", ds_err);
3348 logeventf(ssh, "Could not set up connection sharing"
3349 " as upstream: %s", us_err);
3351 } else if (event == SHARE_DOWNSTREAM) {
3352 /* In this case, 'logtext' is a local endpoint address */
3353 logeventf(ssh, "Using existing shared connection at %s", logtext);
3354 /* Also we should mention this in the console window to avoid
3355 * confusing users as to why this window doesn't behave the
3357 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3358 c_write_str(ssh,"Reusing a shared connection to this server.\r\n");
3360 } else if (event == SHARE_UPSTREAM) {
3361 /* In this case, 'logtext' is a local endpoint address too */
3362 logeventf(ssh, "Sharing this connection at %s", logtext);
3366 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
3369 Ssh ssh = (Ssh) plug;
3370 int need_notify = ssh_do_close(ssh, FALSE);
3373 if (!ssh->close_expected)
3374 error_msg = "Server unexpectedly closed network connection";
3376 error_msg = "Server closed network connection";
3379 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
3383 notify_remote_exit(ssh->frontend);
3386 logevent(error_msg);
3387 if (!ssh->close_expected || !ssh->clean_exit)
3388 connection_fatal(ssh->frontend, "%s", error_msg);
3392 static int ssh_receive(Plug plug, int urgent, char *data, int len)
3394 Ssh ssh = (Ssh) plug;
3395 ssh_gotdata(ssh, (unsigned char *)data, len);
3396 if (ssh->state == SSH_STATE_CLOSED) {
3397 ssh_do_close(ssh, TRUE);
3403 static void ssh_sent(Plug plug, int bufsize)
3405 Ssh ssh = (Ssh) plug;
3407 * If the send backlog on the SSH socket itself clears, we
3408 * should unthrottle the whole world if it was throttled.
3410 if (bufsize < SSH_MAX_BACKLOG)
3411 ssh_throttle_all(ssh, 0, bufsize);
3415 * Connect to specified host and port.
3416 * Returns an error message, or NULL on success.
3417 * Also places the canonical host name into `realhost'. It must be
3418 * freed by the caller.
3420 static const char *connect_to_host(Ssh ssh, char *host, int port,
3421 char **realhost, int nodelay, int keepalive)
3423 static const struct plug_function_table fn_table = {
3434 int addressfamily, sshprot;
3436 loghost = conf_get_str(ssh->conf, CONF_loghost);
3441 tmphost = dupstr(loghost);
3442 ssh->savedport = 22; /* default ssh port */
3445 * A colon suffix on the hostname string also lets us affect
3446 * savedport. (Unless there are multiple colons, in which case
3447 * we assume this is an unbracketed IPv6 literal.)
3449 colon = host_strrchr(tmphost, ':');
3450 if (colon && colon == host_strchr(tmphost, ':')) {
3453 ssh->savedport = atoi(colon);
3456 ssh->savedhost = host_strduptrim(tmphost);
3459 ssh->savedhost = host_strduptrim(host);
3461 port = 22; /* default ssh port */
3462 ssh->savedport = port;
3465 ssh->fn = &fn_table; /* make 'ssh' usable as a Plug */
3468 * Try connection-sharing, in case that means we don't open a
3469 * socket after all. ssh_connection_sharing_init will connect to a
3470 * previously established upstream if it can, and failing that,
3471 * establish a listening socket for _us_ to be the upstream. In
3472 * the latter case it will return NULL just as if it had done
3473 * nothing, because here we only need to care if we're a
3474 * downstream and need to do our connection setup differently.
3476 ssh->connshare = NULL;
3477 ssh->attempting_connshare = TRUE; /* affects socket logging behaviour */
3478 ssh->s = ssh_connection_sharing_init(ssh->savedhost, ssh->savedport,
3479 ssh->conf, ssh, &ssh->connshare);
3480 ssh->attempting_connshare = FALSE;
3481 if (ssh->s != NULL) {
3483 * We are a downstream.
3485 ssh->bare_connection = TRUE;
3486 ssh->do_ssh_init = do_ssh_connection_init;
3487 ssh->fullhostname = NULL;
3488 *realhost = dupstr(host); /* best we can do */
3491 * We're not a downstream, so open a normal socket.
3493 ssh->do_ssh_init = do_ssh_init;
3498 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
3499 logeventf(ssh, "Looking up host \"%s\"%s", host,
3500 (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
3501 (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
3502 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily);
3503 if ((err = sk_addr_error(addr)) != NULL) {
3507 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3509 ssh->s = new_connection(addr, *realhost, port,
3510 0, 1, nodelay, keepalive,
3511 (Plug) ssh, ssh->conf);
3512 if ((err = sk_socket_error(ssh->s)) != NULL) {
3514 notify_remote_exit(ssh->frontend);
3520 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3521 * send the version string too.
3523 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3526 if (sshprot == 3 && !ssh->bare_connection) {
3528 ssh_send_verstring(ssh, "SSH-", NULL);
3532 * loghost, if configured, overrides realhost.
3536 *realhost = dupstr(loghost);
3543 * Throttle or unthrottle the SSH connection.
3545 static void ssh_throttle_conn(Ssh ssh, int adjust)
3547 int old_count = ssh->conn_throttle_count;
3548 ssh->conn_throttle_count += adjust;
3549 assert(ssh->conn_throttle_count >= 0);
3550 if (ssh->conn_throttle_count && !old_count) {
3551 ssh_set_frozen(ssh, 1);
3552 } else if (!ssh->conn_throttle_count && old_count) {
3553 ssh_set_frozen(ssh, 0);
3558 * Throttle or unthrottle _all_ local data streams (for when sends
3559 * on the SSH connection itself back up).
3561 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3564 struct ssh_channel *c;
3566 if (enable == ssh->throttled_all)
3568 ssh->throttled_all = enable;
3569 ssh->overall_bufsize = bufsize;
3572 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3574 case CHAN_MAINSESSION:
3576 * This is treated separately, outside the switch.
3580 x11_override_throttle(c->u.x11.xconn, enable);
3583 /* Agent channels require no buffer management. */
3586 pfd_override_throttle(c->u.pfd.pf, enable);
3592 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3594 Ssh ssh = (Ssh) sshv;
3596 ssh->agent_response = reply;
3597 ssh->agent_response_len = replylen;
3599 if (ssh->version == 1)
3600 do_ssh1_login(ssh, NULL, -1, NULL);
3602 do_ssh2_authconn(ssh, NULL, -1, NULL);
3605 static void ssh_dialog_callback(void *sshv, int ret)
3607 Ssh ssh = (Ssh) sshv;
3609 ssh->user_response = ret;
3611 if (ssh->version == 1)
3612 do_ssh1_login(ssh, NULL, -1, NULL);
3614 do_ssh2_transport(ssh, NULL, -1, NULL);
3617 * This may have unfrozen the SSH connection, so do a
3620 ssh_process_queued_incoming_data(ssh);
3623 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3625 struct ssh_channel *c = (struct ssh_channel *)cv;
3627 void *sentreply = reply;
3629 c->u.a.outstanding_requests--;
3631 /* Fake SSH_AGENT_FAILURE. */
3632 sentreply = "\0\0\0\1\5";
3635 if (ssh->version == 2) {
3636 ssh2_add_channel_data(c, sentreply, replylen);
3639 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3640 PKT_INT, c->remoteid,
3642 PKT_DATA, sentreply, replylen,
3648 * If we've already seen an incoming EOF but haven't sent an
3649 * outgoing one, this may be the moment to send it.
3651 if (c->u.a.outstanding_requests == 0 && (c->closes & CLOSES_RCVD_EOF))
3652 sshfwd_write_eof(c);
3656 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3657 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3658 * => log `wire_reason'.
3660 static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
3661 int code, int clean_exit)
3665 client_reason = wire_reason;
3667 error = dupprintf("Disconnected: %s", client_reason);
3669 error = dupstr("Disconnected");
3671 if (ssh->version == 1) {
3672 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3674 } else if (ssh->version == 2) {
3675 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3676 ssh2_pkt_adduint32(pktout, code);
3677 ssh2_pkt_addstring(pktout, wire_reason);
3678 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3679 ssh2_pkt_send_noqueue(ssh, pktout);
3682 ssh->close_expected = TRUE;
3683 ssh->clean_exit = clean_exit;
3684 ssh_closing((Plug)ssh, error, 0, 0);
3688 int verify_ssh_manual_host_key(Ssh ssh, const char *fingerprint,
3689 const struct ssh_signkey *ssh2keytype,
3692 if (!conf_get_str_nthstrkey(ssh->conf, CONF_ssh_manual_hostkeys, 0)) {
3693 return -1; /* no manual keys configured */
3698 * The fingerprint string we've been given will have things
3699 * like 'ssh-rsa 2048' at the front of it. Strip those off and
3700 * narrow down to just the colon-separated hex block at the
3701 * end of the string.
3703 const char *p = strrchr(fingerprint, ' ');
3704 fingerprint = p ? p+1 : fingerprint;
3705 /* Quick sanity checks, including making sure it's in lowercase */
3706 assert(strlen(fingerprint) == 16*3 - 1);
3707 assert(fingerprint[2] == ':');
3708 assert(fingerprint[strspn(fingerprint, "0123456789abcdef:")] == 0);
3710 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3712 return 1; /* success */
3717 * Construct the base64-encoded public key blob and see if
3720 unsigned char *binblob;
3722 int binlen, atoms, i;
3723 binblob = ssh2keytype->public_blob(ssh2keydata, &binlen);
3724 atoms = (binlen + 2) / 3;
3725 base64blob = snewn(atoms * 4 + 1, char);
3726 for (i = 0; i < atoms; i++)
3727 base64_encode_atom(binblob + 3*i, binlen - 3*i, base64blob + 4*i);
3728 base64blob[atoms * 4] = '\0';
3730 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3733 return 1; /* success */
3742 * Handle the key exchange and user authentication phases.
3744 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
3745 struct Packet *pktin)
3748 unsigned char cookie[8], *ptr;
3749 struct MD5Context md5c;
3750 struct do_ssh1_login_state {
3753 unsigned char *rsabuf, *keystr1, *keystr2;
3754 unsigned long supported_ciphers_mask, supported_auths_mask;
3755 int tried_publickey, tried_agent;
3756 int tis_auth_refused, ccard_auth_refused;
3757 unsigned char session_id[16];
3759 void *publickey_blob;
3760 int publickey_bloblen;
3761 char *publickey_comment;
3762 int publickey_encrypted;
3763 prompts_t *cur_prompt;
3766 unsigned char request[5], *response, *p;
3776 struct RSAKey servkey, hostkey;
3778 crState(do_ssh1_login_state);
3785 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
3786 bombout(("Public key packet not received"));
3790 logevent("Received public keys");
3792 ptr = ssh_pkt_getdata(pktin, 8);
3794 bombout(("SSH-1 public key packet stopped before random cookie"));
3797 memcpy(cookie, ptr, 8);
3799 if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) ||
3800 !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) {
3801 bombout(("Failed to read SSH-1 public keys from public key packet"));
3806 * Log the host key fingerprint.
3810 logevent("Host key fingerprint is:");
3811 strcpy(logmsg, " ");
3812 s->hostkey.comment = NULL;
3813 rsa_fingerprint(logmsg + strlen(logmsg),
3814 sizeof(logmsg) - strlen(logmsg), &s->hostkey);
3818 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3819 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3820 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
3821 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
3822 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
3824 ssh->v1_local_protoflags =
3825 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3826 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
3829 MD5Update(&md5c, s->keystr2, s->hostkey.bytes);
3830 MD5Update(&md5c, s->keystr1, s->servkey.bytes);
3831 MD5Update(&md5c, cookie, 8);
3832 MD5Final(s->session_id, &md5c);
3834 for (i = 0; i < 32; i++)
3835 ssh->session_key[i] = random_byte();
3838 * Verify that the `bits' and `bytes' parameters match.
3840 if (s->hostkey.bits > s->hostkey.bytes * 8 ||
3841 s->servkey.bits > s->servkey.bytes * 8) {
3842 bombout(("SSH-1 public keys were badly formatted"));
3846 s->len = (s->hostkey.bytes > s->servkey.bytes ?
3847 s->hostkey.bytes : s->servkey.bytes);
3849 s->rsabuf = snewn(s->len, unsigned char);
3852 * Verify the host key.
3856 * First format the key into a string.
3858 int len = rsastr_len(&s->hostkey);
3859 char fingerprint[100];
3860 char *keystr = snewn(len, char);
3861 rsastr_fmt(keystr, &s->hostkey);
3862 rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey);
3864 /* First check against manually configured host keys. */
3865 s->dlgret = verify_ssh_manual_host_key(ssh, fingerprint, NULL, NULL);
3866 if (s->dlgret == 0) { /* did not match */
3867 bombout(("Host key did not appear in manually configured list"));
3869 } else if (s->dlgret < 0) { /* none configured; use standard handling */
3870 ssh_set_frozen(ssh, 1);
3871 s->dlgret = verify_ssh_host_key(ssh->frontend,
3872 ssh->savedhost, ssh->savedport,
3873 "rsa", keystr, fingerprint,
3874 ssh_dialog_callback, ssh);
3876 if (s->dlgret < 0) {
3880 bombout(("Unexpected data from server while waiting"
3881 " for user host key response"));
3884 } while (pktin || inlen > 0);
3885 s->dlgret = ssh->user_response;
3887 ssh_set_frozen(ssh, 0);
3889 if (s->dlgret == 0) {
3890 ssh_disconnect(ssh, "User aborted at host key verification",
3897 for (i = 0; i < 32; i++) {
3898 s->rsabuf[i] = ssh->session_key[i];
3900 s->rsabuf[i] ^= s->session_id[i];
3903 if (s->hostkey.bytes > s->servkey.bytes) {
3904 ret = rsaencrypt(s->rsabuf, 32, &s->servkey);
3906 ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey);
3908 ret = rsaencrypt(s->rsabuf, 32, &s->hostkey);
3910 ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey);
3913 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3917 logevent("Encrypted session key");
3920 int cipher_chosen = 0, warn = 0;
3921 char *cipher_string = NULL;
3923 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
3924 int next_cipher = conf_get_int_int(ssh->conf,
3925 CONF_ssh_cipherlist, i);
3926 if (next_cipher == CIPHER_WARN) {
3927 /* If/when we choose a cipher, warn about it */
3929 } else if (next_cipher == CIPHER_AES) {
3930 /* XXX Probably don't need to mention this. */
3931 logevent("AES not supported in SSH-1, skipping");
3933 switch (next_cipher) {
3934 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
3935 cipher_string = "3DES"; break;
3936 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
3937 cipher_string = "Blowfish"; break;
3938 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
3939 cipher_string = "single-DES"; break;
3941 if (s->supported_ciphers_mask & (1 << s->cipher_type))
3945 if (!cipher_chosen) {
3946 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
3947 bombout(("Server violates SSH-1 protocol by not "
3948 "supporting 3DES encryption"));
3950 /* shouldn't happen */
3951 bombout(("No supported ciphers found"));
3955 /* Warn about chosen cipher if necessary. */
3957 ssh_set_frozen(ssh, 1);
3958 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3959 ssh_dialog_callback, ssh);
3960 if (s->dlgret < 0) {
3964 bombout(("Unexpected data from server while waiting"
3965 " for user response"));
3968 } while (pktin || inlen > 0);
3969 s->dlgret = ssh->user_response;
3971 ssh_set_frozen(ssh, 0);
3972 if (s->dlgret == 0) {
3973 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3980 switch (s->cipher_type) {
3981 case SSH_CIPHER_3DES:
3982 logevent("Using 3DES encryption");
3984 case SSH_CIPHER_DES:
3985 logevent("Using single-DES encryption");
3987 case SSH_CIPHER_BLOWFISH:
3988 logevent("Using Blowfish encryption");
3992 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3993 PKT_CHAR, s->cipher_type,
3994 PKT_DATA, cookie, 8,
3995 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3996 PKT_DATA, s->rsabuf, s->len,
3997 PKT_INT, ssh->v1_local_protoflags, PKT_END);
3999 logevent("Trying to enable encryption...");
4003 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
4004 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
4006 ssh->v1_cipher_ctx = ssh->cipher->make_context();
4007 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
4008 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
4010 ssh->crcda_ctx = crcda_make_context();
4011 logevent("Installing CRC compensation attack detector");
4013 if (s->servkey.modulus) {
4014 sfree(s->servkey.modulus);
4015 s->servkey.modulus = NULL;
4017 if (s->servkey.exponent) {
4018 sfree(s->servkey.exponent);
4019 s->servkey.exponent = NULL;
4021 if (s->hostkey.modulus) {
4022 sfree(s->hostkey.modulus);
4023 s->hostkey.modulus = NULL;
4025 if (s->hostkey.exponent) {
4026 sfree(s->hostkey.exponent);
4027 s->hostkey.exponent = NULL;
4031 if (pktin->type != SSH1_SMSG_SUCCESS) {
4032 bombout(("Encryption not successfully enabled"));
4036 logevent("Successfully started encryption");
4038 fflush(stdout); /* FIXME eh? */
4040 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
4041 int ret; /* need not be kept over crReturn */
4042 s->cur_prompt = new_prompts(ssh->frontend);
4043 s->cur_prompt->to_server = TRUE;
4044 s->cur_prompt->name = dupstr("SSH login name");
4045 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
4046 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4049 crWaitUntil(!pktin);
4050 ret = get_userpass_input(s->cur_prompt, in, inlen);
4055 * Failed to get a username. Terminate.
4057 free_prompts(s->cur_prompt);
4058 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
4061 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
4062 free_prompts(s->cur_prompt);
4065 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
4067 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
4069 if (flags & FLAG_INTERACTIVE &&
4070 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
4071 c_write_str(ssh, userlog);
4072 c_write_str(ssh, "\r\n");
4080 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
4081 /* We must not attempt PK auth. Pretend we've already tried it. */
4082 s->tried_publickey = s->tried_agent = 1;
4084 s->tried_publickey = s->tried_agent = 0;
4086 s->tis_auth_refused = s->ccard_auth_refused = 0;
4088 * Load the public half of any configured keyfile for later use.
4090 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4091 if (!filename_is_null(s->keyfile)) {
4093 logeventf(ssh, "Reading private key file \"%.150s\"",
4094 filename_to_str(s->keyfile));
4095 keytype = key_type(s->keyfile);
4096 if (keytype == SSH_KEYTYPE_SSH1) {
4098 if (rsakey_pubblob(s->keyfile,
4099 &s->publickey_blob, &s->publickey_bloblen,
4100 &s->publickey_comment, &error)) {
4101 s->publickey_encrypted = rsakey_encrypted(s->keyfile,
4105 logeventf(ssh, "Unable to load private key (%s)", error);
4106 msgbuf = dupprintf("Unable to load private key file "
4107 "\"%.150s\" (%s)\r\n",
4108 filename_to_str(s->keyfile),
4110 c_write_str(ssh, msgbuf);
4112 s->publickey_blob = NULL;
4116 logeventf(ssh, "Unable to use this key file (%s)",
4117 key_type_to_str(keytype));
4118 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4120 filename_to_str(s->keyfile),
4121 key_type_to_str(keytype));
4122 c_write_str(ssh, msgbuf);
4124 s->publickey_blob = NULL;
4127 s->publickey_blob = NULL;
4129 while (pktin->type == SSH1_SMSG_FAILURE) {
4130 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
4132 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
4134 * Attempt RSA authentication using Pageant.
4140 logevent("Pageant is running. Requesting keys.");
4142 /* Request the keys held by the agent. */
4143 PUT_32BIT(s->request, 1);
4144 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
4145 if (!agent_query(s->request, 5, &r, &s->responselen,
4146 ssh_agent_callback, ssh)) {
4150 bombout(("Unexpected data from server while waiting"
4151 " for agent response"));
4154 } while (pktin || inlen > 0);
4155 r = ssh->agent_response;
4156 s->responselen = ssh->agent_response_len;
4158 s->response = (unsigned char *) r;
4159 if (s->response && s->responselen >= 5 &&
4160 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
4161 s->p = s->response + 5;
4162 s->nkeys = toint(GET_32BIT(s->p));
4164 logeventf(ssh, "Pageant reported negative key count %d",
4169 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
4170 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4171 unsigned char *pkblob = s->p;
4175 do { /* do while (0) to make breaking easy */
4176 n = ssh1_read_bignum
4177 (s->p, toint(s->responselen-(s->p-s->response)),
4182 n = ssh1_read_bignum
4183 (s->p, toint(s->responselen-(s->p-s->response)),
4188 if (s->responselen - (s->p-s->response) < 4)
4190 s->commentlen = toint(GET_32BIT(s->p));
4192 if (s->commentlen < 0 ||
4193 toint(s->responselen - (s->p-s->response)) <
4196 s->commentp = (char *)s->p;
4197 s->p += s->commentlen;
4201 logevent("Pageant key list packet was truncated");
4205 if (s->publickey_blob) {
4206 if (!memcmp(pkblob, s->publickey_blob,
4207 s->publickey_bloblen)) {
4208 logeventf(ssh, "Pageant key #%d matches "
4209 "configured key file", s->keyi);
4210 s->tried_publickey = 1;
4212 /* Skip non-configured key */
4215 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
4216 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4217 PKT_BIGNUM, s->key.modulus, PKT_END);
4219 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4220 logevent("Key refused");
4223 logevent("Received RSA challenge");
4224 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4225 bombout(("Server's RSA challenge was badly formatted"));
4230 char *agentreq, *q, *ret;
4233 len = 1 + 4; /* message type, bit count */
4234 len += ssh1_bignum_length(s->key.exponent);
4235 len += ssh1_bignum_length(s->key.modulus);
4236 len += ssh1_bignum_length(s->challenge);
4237 len += 16; /* session id */
4238 len += 4; /* response format */
4239 agentreq = snewn(4 + len, char);
4240 PUT_32BIT(agentreq, len);
4242 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
4243 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
4245 q += ssh1_write_bignum(q, s->key.exponent);
4246 q += ssh1_write_bignum(q, s->key.modulus);
4247 q += ssh1_write_bignum(q, s->challenge);
4248 memcpy(q, s->session_id, 16);
4250 PUT_32BIT(q, 1); /* response format */
4251 if (!agent_query(agentreq, len + 4, &vret, &retlen,
4252 ssh_agent_callback, ssh)) {
4257 bombout(("Unexpected data from server"
4258 " while waiting for agent"
4262 } while (pktin || inlen > 0);
4263 vret = ssh->agent_response;
4264 retlen = ssh->agent_response_len;
4269 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
4270 logevent("Sending Pageant's response");
4271 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4272 PKT_DATA, ret + 5, 16,
4276 if (pktin->type == SSH1_SMSG_SUCCESS) {
4278 ("Pageant's response accepted");
4279 if (flags & FLAG_VERBOSE) {
4280 c_write_str(ssh, "Authenticated using"
4282 c_write(ssh, s->commentp,
4284 c_write_str(ssh, "\" from agent\r\n");
4289 ("Pageant's response not accepted");
4292 ("Pageant failed to answer challenge");
4296 logevent("No reply received from Pageant");
4299 freebn(s->key.exponent);
4300 freebn(s->key.modulus);
4301 freebn(s->challenge);
4306 if (s->publickey_blob && !s->tried_publickey)
4307 logevent("Configured key file not in Pageant");
4309 logevent("Failed to get reply from Pageant");
4314 if (s->publickey_blob && !s->tried_publickey) {
4316 * Try public key authentication with the specified
4319 int got_passphrase; /* need not be kept over crReturn */
4320 if (flags & FLAG_VERBOSE)
4321 c_write_str(ssh, "Trying public key authentication.\r\n");
4322 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4323 logeventf(ssh, "Trying public key \"%s\"",
4324 filename_to_str(s->keyfile));
4325 s->tried_publickey = 1;
4326 got_passphrase = FALSE;
4327 while (!got_passphrase) {
4329 * Get a passphrase, if necessary.
4331 char *passphrase = NULL; /* only written after crReturn */
4333 if (!s->publickey_encrypted) {
4334 if (flags & FLAG_VERBOSE)
4335 c_write_str(ssh, "No passphrase required.\r\n");
4338 int ret; /* need not be kept over crReturn */
4339 s->cur_prompt = new_prompts(ssh->frontend);
4340 s->cur_prompt->to_server = FALSE;
4341 s->cur_prompt->name = dupstr("SSH key passphrase");
4342 add_prompt(s->cur_prompt,
4343 dupprintf("Passphrase for key \"%.100s\": ",
4344 s->publickey_comment), FALSE);
4345 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4348 crWaitUntil(!pktin);
4349 ret = get_userpass_input(s->cur_prompt, in, inlen);
4353 /* Failed to get a passphrase. Terminate. */
4354 free_prompts(s->cur_prompt);
4355 ssh_disconnect(ssh, NULL, "Unable to authenticate",
4359 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
4360 free_prompts(s->cur_prompt);
4363 * Try decrypting key with passphrase.
4365 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4366 ret = loadrsakey(s->keyfile, &s->key, passphrase,
4369 smemclr(passphrase, strlen(passphrase));
4373 /* Correct passphrase. */
4374 got_passphrase = TRUE;
4375 } else if (ret == 0) {
4376 c_write_str(ssh, "Couldn't load private key from ");
4377 c_write_str(ssh, filename_to_str(s->keyfile));
4378 c_write_str(ssh, " (");
4379 c_write_str(ssh, error);
4380 c_write_str(ssh, ").\r\n");
4381 got_passphrase = FALSE;
4382 break; /* go and try something else */
4383 } else if (ret == -1) {
4384 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
4385 got_passphrase = FALSE;
4388 assert(0 && "unexpected return from loadrsakey()");
4389 got_passphrase = FALSE; /* placate optimisers */
4393 if (got_passphrase) {
4396 * Send a public key attempt.
4398 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4399 PKT_BIGNUM, s->key.modulus, PKT_END);
4402 if (pktin->type == SSH1_SMSG_FAILURE) {
4403 c_write_str(ssh, "Server refused our public key.\r\n");
4404 continue; /* go and try something else */
4406 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4407 bombout(("Bizarre response to offer of public key"));
4413 unsigned char buffer[32];
4414 Bignum challenge, response;
4416 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4417 bombout(("Server's RSA challenge was badly formatted"));
4420 response = rsadecrypt(challenge, &s->key);
4421 freebn(s->key.private_exponent);/* burn the evidence */
4423 for (i = 0; i < 32; i++) {
4424 buffer[i] = bignum_byte(response, 31 - i);
4428 MD5Update(&md5c, buffer, 32);
4429 MD5Update(&md5c, s->session_id, 16);
4430 MD5Final(buffer, &md5c);
4432 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4433 PKT_DATA, buffer, 16, PKT_END);
4440 if (pktin->type == SSH1_SMSG_FAILURE) {
4441 if (flags & FLAG_VERBOSE)
4442 c_write_str(ssh, "Failed to authenticate with"
4443 " our public key.\r\n");
4444 continue; /* go and try something else */
4445 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4446 bombout(("Bizarre response to RSA authentication response"));
4450 break; /* we're through! */
4456 * Otherwise, try various forms of password-like authentication.
4458 s->cur_prompt = new_prompts(ssh->frontend);
4460 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4461 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
4462 !s->tis_auth_refused) {
4463 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
4464 logevent("Requested TIS authentication");
4465 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
4467 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
4468 logevent("TIS authentication declined");
4469 if (flags & FLAG_INTERACTIVE)
4470 c_write_str(ssh, "TIS authentication refused.\r\n");
4471 s->tis_auth_refused = 1;
4476 char *instr_suf, *prompt;
4478 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4480 bombout(("TIS challenge packet was badly formed"));
4483 logevent("Received TIS challenge");
4484 s->cur_prompt->to_server = TRUE;
4485 s->cur_prompt->name = dupstr("SSH TIS authentication");
4486 /* Prompt heuristic comes from OpenSSH */
4487 if (memchr(challenge, '\n', challengelen)) {
4488 instr_suf = dupstr("");
4489 prompt = dupprintf("%.*s", challengelen, challenge);
4491 instr_suf = dupprintf("%.*s", challengelen, challenge);
4492 prompt = dupstr("Response: ");
4494 s->cur_prompt->instruction =
4495 dupprintf("Using TIS authentication.%s%s",
4496 (*instr_suf) ? "\n" : "",
4498 s->cur_prompt->instr_reqd = TRUE;
4499 add_prompt(s->cur_prompt, prompt, FALSE);
4503 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4504 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
4505 !s->ccard_auth_refused) {
4506 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
4507 logevent("Requested CryptoCard authentication");
4508 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
4510 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
4511 logevent("CryptoCard authentication declined");
4512 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4513 s->ccard_auth_refused = 1;
4518 char *instr_suf, *prompt;
4520 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4522 bombout(("CryptoCard challenge packet was badly formed"));
4525 logevent("Received CryptoCard challenge");
4526 s->cur_prompt->to_server = TRUE;
4527 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4528 s->cur_prompt->name_reqd = FALSE;
4529 /* Prompt heuristic comes from OpenSSH */
4530 if (memchr(challenge, '\n', challengelen)) {
4531 instr_suf = dupstr("");
4532 prompt = dupprintf("%.*s", challengelen, challenge);
4534 instr_suf = dupprintf("%.*s", challengelen, challenge);
4535 prompt = dupstr("Response: ");
4537 s->cur_prompt->instruction =
4538 dupprintf("Using CryptoCard authentication.%s%s",
4539 (*instr_suf) ? "\n" : "",
4541 s->cur_prompt->instr_reqd = TRUE;
4542 add_prompt(s->cur_prompt, prompt, FALSE);
4546 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4547 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4548 bombout(("No supported authentication methods available"));
4551 s->cur_prompt->to_server = TRUE;
4552 s->cur_prompt->name = dupstr("SSH password");
4553 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4554 ssh->username, ssh->savedhost),
4559 * Show password prompt, having first obtained it via a TIS
4560 * or CryptoCard exchange if we're doing TIS or CryptoCard
4564 int ret; /* need not be kept over crReturn */
4565 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4568 crWaitUntil(!pktin);
4569 ret = get_userpass_input(s->cur_prompt, in, inlen);
4574 * Failed to get a password (for example
4575 * because one was supplied on the command line
4576 * which has already failed to work). Terminate.
4578 free_prompts(s->cur_prompt);
4579 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4584 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4586 * Defence against traffic analysis: we send a
4587 * whole bunch of packets containing strings of
4588 * different lengths. One of these strings is the
4589 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4590 * The others are all random data in
4591 * SSH1_MSG_IGNORE packets. This way a passive
4592 * listener can't tell which is the password, and
4593 * hence can't deduce the password length.
4595 * Anybody with a password length greater than 16
4596 * bytes is going to have enough entropy in their
4597 * password that a listener won't find it _that_
4598 * much help to know how long it is. So what we'll
4601 * - if password length < 16, we send 15 packets
4602 * containing string lengths 1 through 15
4604 * - otherwise, we let N be the nearest multiple
4605 * of 8 below the password length, and send 8
4606 * packets containing string lengths N through
4607 * N+7. This won't obscure the order of
4608 * magnitude of the password length, but it will
4609 * introduce a bit of extra uncertainty.
4611 * A few servers can't deal with SSH1_MSG_IGNORE, at
4612 * least in this context. For these servers, we need
4613 * an alternative defence. We make use of the fact
4614 * that the password is interpreted as a C string:
4615 * so we can append a NUL, then some random data.
4617 * A few servers can deal with neither SSH1_MSG_IGNORE
4618 * here _nor_ a padded password string.
4619 * For these servers we are left with no defences
4620 * against password length sniffing.
4622 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4623 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4625 * The server can deal with SSH1_MSG_IGNORE, so
4626 * we can use the primary defence.
4628 int bottom, top, pwlen, i;
4631 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4633 bottom = 0; /* zero length passwords are OK! :-) */
4636 bottom = pwlen & ~7;
4640 assert(pwlen >= bottom && pwlen <= top);
4642 randomstr = snewn(top + 1, char);
4644 for (i = bottom; i <= top; i++) {
4646 defer_packet(ssh, s->pwpkt_type,
4647 PKT_STR,s->cur_prompt->prompts[0]->result,
4650 for (j = 0; j < i; j++) {
4652 randomstr[j] = random_byte();
4653 } while (randomstr[j] == '\0');
4655 randomstr[i] = '\0';
4656 defer_packet(ssh, SSH1_MSG_IGNORE,
4657 PKT_STR, randomstr, PKT_END);
4660 logevent("Sending password with camouflage packets");
4661 ssh_pkt_defersend(ssh);
4664 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4666 * The server can't deal with SSH1_MSG_IGNORE
4667 * but can deal with padded passwords, so we
4668 * can use the secondary defence.
4674 len = strlen(s->cur_prompt->prompts[0]->result);
4675 if (len < sizeof(string)) {
4677 strcpy(string, s->cur_prompt->prompts[0]->result);
4678 len++; /* cover the zero byte */
4679 while (len < sizeof(string)) {
4680 string[len++] = (char) random_byte();
4683 ss = s->cur_prompt->prompts[0]->result;
4685 logevent("Sending length-padded password");
4686 send_packet(ssh, s->pwpkt_type,
4687 PKT_INT, len, PKT_DATA, ss, len,
4691 * The server is believed unable to cope with
4692 * any of our password camouflage methods.
4695 len = strlen(s->cur_prompt->prompts[0]->result);
4696 logevent("Sending unpadded password");
4697 send_packet(ssh, s->pwpkt_type,
4699 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4703 send_packet(ssh, s->pwpkt_type,
4704 PKT_STR, s->cur_prompt->prompts[0]->result,
4707 logevent("Sent password");
4708 free_prompts(s->cur_prompt);
4710 if (pktin->type == SSH1_SMSG_FAILURE) {
4711 if (flags & FLAG_VERBOSE)
4712 c_write_str(ssh, "Access denied\r\n");
4713 logevent("Authentication refused");
4714 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4715 bombout(("Strange packet received, type %d", pktin->type));
4721 if (s->publickey_blob) {
4722 sfree(s->publickey_blob);
4723 sfree(s->publickey_comment);
4726 logevent("Authentication successful");
4731 static void ssh_channel_try_eof(struct ssh_channel *c)
4734 assert(c->pending_eof); /* precondition for calling us */
4736 return; /* can't close: not even opened yet */
4737 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4738 return; /* can't send EOF: pending outgoing data */
4740 c->pending_eof = FALSE; /* we're about to send it */
4741 if (ssh->version == 1) {
4742 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4744 c->closes |= CLOSES_SENT_EOF;
4746 struct Packet *pktout;
4747 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4748 ssh2_pkt_adduint32(pktout, c->remoteid);
4749 ssh2_pkt_send(ssh, pktout);
4750 c->closes |= CLOSES_SENT_EOF;
4751 ssh2_channel_check_close(c);
4755 Conf *sshfwd_get_conf(struct ssh_channel *c)
4761 void sshfwd_write_eof(struct ssh_channel *c)
4765 if (ssh->state == SSH_STATE_CLOSED)
4768 if (c->closes & CLOSES_SENT_EOF)
4771 c->pending_eof = TRUE;
4772 ssh_channel_try_eof(c);
4775 void sshfwd_unclean_close(struct ssh_channel *c, const char *err)
4779 if (ssh->state == SSH_STATE_CLOSED)
4784 x11_close(c->u.x11.xconn);
4785 logeventf(ssh, "Forwarded X11 connection terminated due to local "
4789 case CHAN_SOCKDATA_DORMANT:
4790 pfd_close(c->u.pfd.pf);
4791 logeventf(ssh, "Forwarded port closed due to local error: %s", err);
4794 c->type = CHAN_ZOMBIE;
4795 c->pending_eof = FALSE; /* this will confuse a zombie channel */
4797 ssh2_channel_check_close(c);
4800 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
4804 if (ssh->state == SSH_STATE_CLOSED)
4807 if (ssh->version == 1) {
4808 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
4809 PKT_INT, c->remoteid,
4810 PKT_INT, len, PKT_DATA, buf, len,
4813 * In SSH-1 we can return 0 here - implying that forwarded
4814 * connections are never individually throttled - because
4815 * the only circumstance that can cause throttling will be
4816 * the whole SSH connection backing up, in which case
4817 * _everything_ will be throttled as a whole.
4821 ssh2_add_channel_data(c, buf, len);
4822 return ssh2_try_send(c);
4826 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4831 if (ssh->state == SSH_STATE_CLOSED)
4834 if (ssh->version == 1) {
4835 buflimit = SSH1_BUFFER_LIMIT;
4837 buflimit = c->v.v2.locmaxwin;
4838 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
4840 if (c->throttling_conn && bufsize <= buflimit) {
4841 c->throttling_conn = 0;
4842 ssh_throttle_conn(ssh, -1);
4846 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
4848 struct queued_handler *qh = ssh->qhead;
4852 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
4855 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
4856 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
4859 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
4860 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
4864 ssh->qhead = qh->next;
4866 if (ssh->qhead->msg1 > 0) {
4867 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4868 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
4870 if (ssh->qhead->msg2 > 0) {
4871 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4872 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
4875 ssh->qhead = ssh->qtail = NULL;
4878 qh->handler(ssh, pktin, qh->ctx);
4883 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
4884 chandler_fn_t handler, void *ctx)
4886 struct queued_handler *qh;
4888 qh = snew(struct queued_handler);
4891 qh->handler = handler;
4895 if (ssh->qtail == NULL) {
4899 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4900 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
4903 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4904 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
4907 ssh->qtail->next = qh;
4912 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
4914 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
4916 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
4917 SSH2_MSG_REQUEST_SUCCESS)) {
4918 logeventf(ssh, "Remote port forwarding from %s enabled",
4921 logeventf(ssh, "Remote port forwarding from %s refused",
4924 rpf = del234(ssh->rportfwds, pf);
4926 pf->pfrec->remote = NULL;
4931 int ssh_alloc_sharing_rportfwd(Ssh ssh, const char *shost, int sport,
4934 struct ssh_rportfwd *pf = snew(struct ssh_rportfwd);
4937 pf->share_ctx = share_ctx;
4938 pf->shost = dupstr(shost);
4940 pf->sportdesc = NULL;
4941 if (!ssh->rportfwds) {
4942 assert(ssh->version == 2);
4943 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4945 if (add234(ssh->rportfwds, pf) != pf) {
4953 static void ssh_sharing_global_request_response(Ssh ssh, struct Packet *pktin,
4956 share_got_pkt_from_server(ctx, pktin->type,
4957 pktin->body, pktin->length);
4960 void ssh_sharing_queue_global_request(Ssh ssh, void *share_ctx)
4962 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, SSH2_MSG_REQUEST_FAILURE,
4963 ssh_sharing_global_request_response, share_ctx);
4966 static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
4968 struct ssh_portfwd *epf;
4972 if (!ssh->portfwds) {
4973 ssh->portfwds = newtree234(ssh_portcmp);
4976 * Go through the existing port forwardings and tag them
4977 * with status==DESTROY. Any that we want to keep will be
4978 * re-enabled (status==KEEP) as we go through the
4979 * configuration and find out which bits are the same as
4982 struct ssh_portfwd *epf;
4984 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4985 epf->status = DESTROY;
4988 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
4990 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
4991 char *kp, *kp2, *vp, *vp2;
4992 char address_family, type;
4993 int sport,dport,sserv,dserv;
4994 char *sports, *dports, *saddr, *host;
4998 address_family = 'A';
5000 if (*kp == 'A' || *kp == '4' || *kp == '6')
5001 address_family = *kp++;
5002 if (*kp == 'L' || *kp == 'R')
5005 if ((kp2 = host_strchr(kp, ':')) != NULL) {
5007 * There's a colon in the middle of the source port
5008 * string, which means that the part before it is
5009 * actually a source address.
5011 char *saddr_tmp = dupprintf("%.*s", (int)(kp2 - kp), kp);
5012 saddr = host_strduptrim(saddr_tmp);
5019 sport = atoi(sports);
5023 sport = net_service_lookup(sports);
5025 logeventf(ssh, "Service lookup failed for source"
5026 " port \"%s\"", sports);
5030 if (type == 'L' && !strcmp(val, "D")) {
5031 /* dynamic forwarding */
5038 /* ordinary forwarding */
5040 vp2 = vp + host_strcspn(vp, ":");
5041 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
5045 dport = atoi(dports);
5049 dport = net_service_lookup(dports);
5051 logeventf(ssh, "Service lookup failed for destination"
5052 " port \"%s\"", dports);
5057 if (sport && dport) {
5058 /* Set up a description of the source port. */
5059 struct ssh_portfwd *pfrec, *epfrec;
5061 pfrec = snew(struct ssh_portfwd);
5063 pfrec->saddr = saddr;
5064 pfrec->sserv = sserv ? dupstr(sports) : NULL;
5065 pfrec->sport = sport;
5066 pfrec->daddr = host;
5067 pfrec->dserv = dserv ? dupstr(dports) : NULL;
5068 pfrec->dport = dport;
5069 pfrec->local = NULL;
5070 pfrec->remote = NULL;
5071 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
5072 address_family == '6' ? ADDRTYPE_IPV6 :
5075 epfrec = add234(ssh->portfwds, pfrec);
5076 if (epfrec != pfrec) {
5077 if (epfrec->status == DESTROY) {
5079 * We already have a port forwarding up and running
5080 * with precisely these parameters. Hence, no need
5081 * to do anything; simply re-tag the existing one
5084 epfrec->status = KEEP;
5087 * Anything else indicates that there was a duplicate
5088 * in our input, which we'll silently ignore.
5090 free_portfwd(pfrec);
5092 pfrec->status = CREATE;
5101 * Now go through and destroy any port forwardings which were
5104 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5105 if (epf->status == DESTROY) {
5108 message = dupprintf("%s port forwarding from %s%s%d",
5109 epf->type == 'L' ? "local" :
5110 epf->type == 'R' ? "remote" : "dynamic",
5111 epf->saddr ? epf->saddr : "",
5112 epf->saddr ? ":" : "",
5115 if (epf->type != 'D') {
5116 char *msg2 = dupprintf("%s to %s:%d", message,
5117 epf->daddr, epf->dport);
5122 logeventf(ssh, "Cancelling %s", message);
5125 /* epf->remote or epf->local may be NULL if setting up a
5126 * forwarding failed. */
5128 struct ssh_rportfwd *rpf = epf->remote;
5129 struct Packet *pktout;
5132 * Cancel the port forwarding at the server
5135 if (ssh->version == 1) {
5137 * We cannot cancel listening ports on the
5138 * server side in SSH-1! There's no message
5139 * to support it. Instead, we simply remove
5140 * the rportfwd record from the local end
5141 * so that any connections the server tries
5142 * to make on it are rejected.
5145 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5146 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
5147 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
5149 ssh2_pkt_addstring(pktout, epf->saddr);
5150 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5151 /* XXX: rport_acceptall may not represent
5152 * what was used to open the original connection,
5153 * since it's reconfigurable. */
5154 ssh2_pkt_addstring(pktout, "");
5156 ssh2_pkt_addstring(pktout, "localhost");
5158 ssh2_pkt_adduint32(pktout, epf->sport);
5159 ssh2_pkt_send(ssh, pktout);
5162 del234(ssh->rportfwds, rpf);
5164 } else if (epf->local) {
5165 pfl_terminate(epf->local);
5168 delpos234(ssh->portfwds, i);
5170 i--; /* so we don't skip one in the list */
5174 * And finally, set up any new port forwardings (status==CREATE).
5176 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5177 if (epf->status == CREATE) {
5178 char *sportdesc, *dportdesc;
5179 sportdesc = dupprintf("%s%s%s%s%d%s",
5180 epf->saddr ? epf->saddr : "",
5181 epf->saddr ? ":" : "",
5182 epf->sserv ? epf->sserv : "",
5183 epf->sserv ? "(" : "",
5185 epf->sserv ? ")" : "");
5186 if (epf->type == 'D') {
5189 dportdesc = dupprintf("%s:%s%s%d%s",
5191 epf->dserv ? epf->dserv : "",
5192 epf->dserv ? "(" : "",
5194 epf->dserv ? ")" : "");
5197 if (epf->type == 'L') {
5198 char *err = pfl_listen(epf->daddr, epf->dport,
5199 epf->saddr, epf->sport,
5200 ssh, conf, &epf->local,
5201 epf->addressfamily);
5203 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
5204 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5205 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5206 sportdesc, dportdesc,
5207 err ? " failed: " : "", err ? err : "");
5210 } else if (epf->type == 'D') {
5211 char *err = pfl_listen(NULL, -1, epf->saddr, epf->sport,
5212 ssh, conf, &epf->local,
5213 epf->addressfamily);
5215 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
5216 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5217 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5219 err ? " failed: " : "", err ? err : "");
5224 struct ssh_rportfwd *pf;
5227 * Ensure the remote port forwardings tree exists.
5229 if (!ssh->rportfwds) {
5230 if (ssh->version == 1)
5231 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
5233 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5236 pf = snew(struct ssh_rportfwd);
5237 pf->share_ctx = NULL;
5238 pf->dhost = dupstr(epf->daddr);
5239 pf->dport = epf->dport;
5241 pf->shost = dupstr(epf->saddr);
5242 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5243 pf->shost = dupstr("");
5245 pf->shost = dupstr("localhost");
5247 pf->sport = epf->sport;
5248 if (add234(ssh->rportfwds, pf) != pf) {
5249 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
5250 epf->daddr, epf->dport);
5253 logeventf(ssh, "Requesting remote port %s"
5254 " forward to %s", sportdesc, dportdesc);
5256 pf->sportdesc = sportdesc;
5261 if (ssh->version == 1) {
5262 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
5263 PKT_INT, epf->sport,
5264 PKT_STR, epf->daddr,
5265 PKT_INT, epf->dport,
5267 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
5269 ssh_rportfwd_succfail, pf);
5271 struct Packet *pktout;
5272 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5273 ssh2_pkt_addstring(pktout, "tcpip-forward");
5274 ssh2_pkt_addbool(pktout, 1);/* want reply */
5275 ssh2_pkt_addstring(pktout, pf->shost);
5276 ssh2_pkt_adduint32(pktout, pf->sport);
5277 ssh2_pkt_send(ssh, pktout);
5279 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
5280 SSH2_MSG_REQUEST_FAILURE,
5281 ssh_rportfwd_succfail, pf);
5290 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
5293 int stringlen, bufsize;
5295 ssh_pkt_getstring(pktin, &string, &stringlen);
5296 if (string == NULL) {
5297 bombout(("Incoming terminal data packet was badly formed"));
5301 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
5303 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
5304 ssh->v1_stdout_throttling = 1;
5305 ssh_throttle_conn(ssh, +1);
5309 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
5311 /* Remote side is trying to open a channel to talk to our
5312 * X-Server. Give them back a local channel number. */
5313 struct ssh_channel *c;
5314 int remoteid = ssh_pkt_getuint32(pktin);
5316 logevent("Received X11 connect request");
5317 /* Refuse if X11 forwarding is disabled. */
5318 if (!ssh->X11_fwd_enabled) {
5319 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5320 PKT_INT, remoteid, PKT_END);
5321 logevent("Rejected X11 connect request");
5323 c = snew(struct ssh_channel);
5326 c->u.x11.xconn = x11_init(ssh->x11authtree, c, NULL, -1);
5327 c->remoteid = remoteid;
5328 c->halfopen = FALSE;
5329 c->localid = alloc_channel_id(ssh);
5331 c->pending_eof = FALSE;
5332 c->throttling_conn = 0;
5333 c->type = CHAN_X11; /* identify channel type */
5334 add234(ssh->channels, c);
5335 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5336 PKT_INT, c->remoteid, PKT_INT,
5337 c->localid, PKT_END);
5338 logevent("Opened X11 forward channel");
5342 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
5344 /* Remote side is trying to open a channel to talk to our
5345 * agent. Give them back a local channel number. */
5346 struct ssh_channel *c;
5347 int remoteid = ssh_pkt_getuint32(pktin);
5349 /* Refuse if agent forwarding is disabled. */
5350 if (!ssh->agentfwd_enabled) {
5351 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5352 PKT_INT, remoteid, PKT_END);
5354 c = snew(struct ssh_channel);
5356 c->remoteid = remoteid;
5357 c->halfopen = FALSE;
5358 c->localid = alloc_channel_id(ssh);
5360 c->pending_eof = FALSE;
5361 c->throttling_conn = 0;
5362 c->type = CHAN_AGENT; /* identify channel type */
5363 c->u.a.lensofar = 0;
5364 c->u.a.message = NULL;
5365 c->u.a.outstanding_requests = 0;
5366 add234(ssh->channels, c);
5367 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5368 PKT_INT, c->remoteid, PKT_INT, c->localid,
5373 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
5375 /* Remote side is trying to open a channel to talk to a
5376 * forwarded port. Give them back a local channel number. */
5377 struct ssh_rportfwd pf, *pfp;
5383 remoteid = ssh_pkt_getuint32(pktin);
5384 ssh_pkt_getstring(pktin, &host, &hostsize);
5385 port = ssh_pkt_getuint32(pktin);
5387 pf.dhost = dupprintf("%.*s", hostsize, host);
5389 pfp = find234(ssh->rportfwds, &pf, NULL);
5392 logeventf(ssh, "Rejected remote port open request for %s:%d",
5394 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5395 PKT_INT, remoteid, PKT_END);
5397 struct ssh_channel *c = snew(struct ssh_channel);
5400 logeventf(ssh, "Received remote port open request for %s:%d",
5402 err = pfd_connect(&c->u.pfd.pf, pf.dhost, port,
5403 c, ssh->conf, pfp->pfrec->addressfamily);
5405 logeventf(ssh, "Port open failed: %s", err);
5408 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5409 PKT_INT, remoteid, PKT_END);
5411 c->remoteid = remoteid;
5412 c->halfopen = FALSE;
5413 c->localid = alloc_channel_id(ssh);
5415 c->pending_eof = FALSE;
5416 c->throttling_conn = 0;
5417 c->type = CHAN_SOCKDATA; /* identify channel type */
5418 add234(ssh->channels, c);
5419 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5420 PKT_INT, c->remoteid, PKT_INT,
5421 c->localid, PKT_END);
5422 logevent("Forwarded port opened successfully");
5429 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5431 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5432 unsigned int localid = ssh_pkt_getuint32(pktin);
5433 struct ssh_channel *c;
5435 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5436 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5437 c->remoteid = localid;
5438 c->halfopen = FALSE;
5439 c->type = CHAN_SOCKDATA;
5440 c->throttling_conn = 0;
5441 pfd_confirm(c->u.pfd.pf);
5444 if (c && c->pending_eof) {
5446 * We have a pending close on this channel,
5447 * which we decided on before the server acked
5448 * the channel open. So now we know the
5449 * remoteid, we can close it again.
5451 ssh_channel_try_eof(c);
5455 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5457 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5458 struct ssh_channel *c;
5460 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5461 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5462 logevent("Forwarded connection refused by server");
5463 pfd_close(c->u.pfd.pf);
5464 del234(ssh->channels, c);
5469 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
5471 /* Remote side closes a channel. */
5472 unsigned i = ssh_pkt_getuint32(pktin);
5473 struct ssh_channel *c;
5474 c = find234(ssh->channels, &i, ssh_channelfind);
5475 if (c && !c->halfopen) {
5477 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
5478 !(c->closes & CLOSES_RCVD_EOF)) {
5480 * Received CHANNEL_CLOSE, which we translate into
5483 int send_close = FALSE;
5485 c->closes |= CLOSES_RCVD_EOF;
5490 x11_send_eof(c->u.x11.xconn);
5496 pfd_send_eof(c->u.pfd.pf);
5505 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
5506 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
5508 c->closes |= CLOSES_SENT_EOF;
5512 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
5513 !(c->closes & CLOSES_RCVD_CLOSE)) {
5515 if (!(c->closes & CLOSES_SENT_EOF)) {
5516 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
5517 " for which we never sent CHANNEL_CLOSE\n", i));
5520 c->closes |= CLOSES_RCVD_CLOSE;
5523 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
5524 !(c->closes & CLOSES_SENT_CLOSE)) {
5525 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
5526 PKT_INT, c->remoteid, PKT_END);
5527 c->closes |= CLOSES_SENT_CLOSE;
5530 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5531 ssh_channel_destroy(c);
5533 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5534 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
5535 "_CONFIRMATION", c ? "half-open" : "nonexistent",
5540 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5542 /* Data sent down one of our channels. */
5543 int i = ssh_pkt_getuint32(pktin);
5546 struct ssh_channel *c;
5548 ssh_pkt_getstring(pktin, &p, &len);
5550 c = find234(ssh->channels, &i, ssh_channelfind);
5555 bufsize = x11_send(c->u.x11.xconn, p, len);
5558 bufsize = pfd_send(c->u.pfd.pf, p, len);
5561 /* Data for an agent message. Buffer it. */
5563 if (c->u.a.lensofar < 4) {
5564 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
5565 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
5569 c->u.a.lensofar += l;
5571 if (c->u.a.lensofar == 4) {
5573 4 + GET_32BIT(c->u.a.msglen);
5574 c->u.a.message = snewn(c->u.a.totallen,
5576 memcpy(c->u.a.message, c->u.a.msglen, 4);
5578 if (c->u.a.lensofar >= 4 && len > 0) {
5580 min(c->u.a.totallen - c->u.a.lensofar,
5582 memcpy(c->u.a.message + c->u.a.lensofar, p,
5586 c->u.a.lensofar += l;
5588 if (c->u.a.lensofar == c->u.a.totallen) {
5591 c->u.a.outstanding_requests++;
5592 if (agent_query(c->u.a.message,
5595 ssh_agentf_callback, c))
5596 ssh_agentf_callback(c, reply, replylen);
5597 sfree(c->u.a.message);
5598 c->u.a.lensofar = 0;
5601 bufsize = 0; /* agent channels never back up */
5604 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5605 c->throttling_conn = 1;
5606 ssh_throttle_conn(ssh, +1);
5611 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5613 ssh->exitcode = ssh_pkt_getuint32(pktin);
5614 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5615 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5617 * In case `helpful' firewalls or proxies tack
5618 * extra human-readable text on the end of the
5619 * session which we might mistake for another
5620 * encrypted packet, we close the session once
5621 * we've sent EXIT_CONFIRMATION.
5623 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5626 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5627 static void ssh1_send_ttymode(void *data, char *mode, char *val)
5629 struct Packet *pktout = (struct Packet *)data;
5631 unsigned int arg = 0;
5632 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5633 if (i == lenof(ssh_ttymodes)) return;
5634 switch (ssh_ttymodes[i].type) {
5636 arg = ssh_tty_parse_specchar(val);
5639 arg = ssh_tty_parse_boolean(val);
5642 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5643 ssh2_pkt_addbyte(pktout, arg);
5646 int ssh_agent_forwarding_permitted(Ssh ssh)
5648 return conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists();
5651 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
5652 struct Packet *pktin)
5654 crBegin(ssh->do_ssh1_connection_crstate);
5656 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5657 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5658 ssh1_smsg_stdout_stderr_data;
5660 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5661 ssh1_msg_channel_open_confirmation;
5662 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5663 ssh1_msg_channel_open_failure;
5664 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5665 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5666 ssh1_msg_channel_close;
5667 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5668 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5670 if (ssh_agent_forwarding_permitted(ssh)) {
5671 logevent("Requesting agent forwarding");
5672 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5676 if (pktin->type != SSH1_SMSG_SUCCESS
5677 && pktin->type != SSH1_SMSG_FAILURE) {
5678 bombout(("Protocol confusion"));
5680 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5681 logevent("Agent forwarding refused");
5683 logevent("Agent forwarding enabled");
5684 ssh->agentfwd_enabled = TRUE;
5685 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5689 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
5691 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5693 if (!ssh->x11disp) {
5694 /* FIXME: return an error message from x11_setup_display */
5695 logevent("X11 forwarding not enabled: unable to"
5696 " initialise X display");
5698 ssh->x11auth = x11_invent_fake_auth
5699 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
5700 ssh->x11auth->disp = ssh->x11disp;
5702 logevent("Requesting X11 forwarding");
5703 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5704 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5705 PKT_STR, ssh->x11auth->protoname,
5706 PKT_STR, ssh->x11auth->datastring,
5707 PKT_INT, ssh->x11disp->screennum,
5710 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5711 PKT_STR, ssh->x11auth->protoname,
5712 PKT_STR, ssh->x11auth->datastring,
5718 if (pktin->type != SSH1_SMSG_SUCCESS
5719 && pktin->type != SSH1_SMSG_FAILURE) {
5720 bombout(("Protocol confusion"));
5722 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5723 logevent("X11 forwarding refused");
5725 logevent("X11 forwarding enabled");
5726 ssh->X11_fwd_enabled = TRUE;
5727 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5732 ssh_setup_portfwd(ssh, ssh->conf);
5733 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5735 if (!conf_get_int(ssh->conf, CONF_nopty)) {
5737 /* Unpick the terminal-speed string. */
5738 /* XXX perhaps we should allow no speeds to be sent. */
5739 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5740 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
5741 /* Send the pty request. */
5742 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5743 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
5744 ssh_pkt_adduint32(pkt, ssh->term_height);
5745 ssh_pkt_adduint32(pkt, ssh->term_width);
5746 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5747 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5748 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
5749 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5750 ssh_pkt_adduint32(pkt, ssh->ispeed);
5751 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5752 ssh_pkt_adduint32(pkt, ssh->ospeed);
5753 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5755 ssh->state = SSH_STATE_INTERMED;
5759 if (pktin->type != SSH1_SMSG_SUCCESS
5760 && pktin->type != SSH1_SMSG_FAILURE) {
5761 bombout(("Protocol confusion"));
5763 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5764 c_write_str(ssh, "Server refused to allocate pty\r\n");
5765 ssh->editing = ssh->echoing = 1;
5767 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5768 ssh->ospeed, ssh->ispeed);
5769 ssh->got_pty = TRUE;
5772 ssh->editing = ssh->echoing = 1;
5775 if (conf_get_int(ssh->conf, CONF_compression)) {
5776 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5780 if (pktin->type != SSH1_SMSG_SUCCESS
5781 && pktin->type != SSH1_SMSG_FAILURE) {
5782 bombout(("Protocol confusion"));
5784 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5785 c_write_str(ssh, "Server refused to compress\r\n");
5787 logevent("Started compression");
5788 ssh->v1_compressing = TRUE;
5789 ssh->cs_comp_ctx = zlib_compress_init();
5790 logevent("Initialised zlib (RFC1950) compression");
5791 ssh->sc_comp_ctx = zlib_decompress_init();
5792 logevent("Initialised zlib (RFC1950) decompression");
5796 * Start the shell or command.
5798 * Special case: if the first-choice command is an SSH-2
5799 * subsystem (hence not usable here) and the second choice
5800 * exists, we fall straight back to that.
5803 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
5805 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
5806 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
5807 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
5808 ssh->fallback_cmd = TRUE;
5811 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
5813 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
5814 logevent("Started session");
5817 ssh->state = SSH_STATE_SESSION;
5818 if (ssh->size_needed)
5819 ssh_size(ssh, ssh->term_width, ssh->term_height);
5820 if (ssh->eof_needed)
5821 ssh_special(ssh, TS_EOF);
5824 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5826 ssh->channels = newtree234(ssh_channelcmp);
5830 * By this point, most incoming packets are already being
5831 * handled by the dispatch table, and we need only pay
5832 * attention to the unusual ones.
5837 if (pktin->type == SSH1_SMSG_SUCCESS) {
5838 /* may be from EXEC_SHELL on some servers */
5839 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5840 /* may be from EXEC_SHELL on some servers
5841 * if no pty is available or in other odd cases. Ignore */
5843 bombout(("Strange packet received: type %d", pktin->type));
5848 int len = min(inlen, 512);
5849 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
5850 PKT_INT, len, PKT_DATA, in, len,
5862 * Handle the top-level SSH-2 protocol.
5864 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
5869 ssh_pkt_getstring(pktin, &msg, &msglen);
5870 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
5873 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
5875 /* log reason code in disconnect message */
5879 ssh_pkt_getstring(pktin, &msg, &msglen);
5880 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
5883 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
5885 /* Do nothing, because we're ignoring it! Duhh. */
5888 static void ssh1_protocol_setup(Ssh ssh)
5893 * Most messages are handled by the coroutines.
5895 for (i = 0; i < 256; i++)
5896 ssh->packet_dispatch[i] = NULL;
5899 * These special message types we install handlers for.
5901 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
5902 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
5903 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
5906 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
5907 struct Packet *pktin)
5909 unsigned char *in=(unsigned char*)vin;
5910 if (ssh->state == SSH_STATE_CLOSED)
5913 if (pktin && ssh->packet_dispatch[pktin->type]) {
5914 ssh->packet_dispatch[pktin->type](ssh, pktin);
5918 if (!ssh->protocol_initial_phase_done) {
5919 if (do_ssh1_login(ssh, in, inlen, pktin))
5920 ssh->protocol_initial_phase_done = TRUE;
5925 do_ssh1_connection(ssh, in, inlen, pktin);
5929 * Utility routine for decoding comma-separated strings in KEXINIT.
5931 static int in_commasep_string(char const *needle, char const *haystack,
5935 if (!needle || !haystack) /* protect against null pointers */
5937 needlen = strlen(needle);
5940 * Is it at the start of the string?
5942 if (haylen >= needlen && /* haystack is long enough */
5943 !memcmp(needle, haystack, needlen) && /* initial match */
5944 (haylen == needlen || haystack[needlen] == ',')
5945 /* either , or EOS follows */
5949 * If not, search for the next comma and resume after that.
5950 * If no comma found, terminate.
5952 while (haylen > 0 && *haystack != ',')
5953 haylen--, haystack++;
5956 haylen--, haystack++; /* skip over comma itself */
5961 * Similar routine for checking whether we have the first string in a list.
5963 static int first_in_commasep_string(char const *needle, char const *haystack,
5967 if (!needle || !haystack) /* protect against null pointers */
5969 needlen = strlen(needle);
5971 * Is it at the start of the string?
5973 if (haylen >= needlen && /* haystack is long enough */
5974 !memcmp(needle, haystack, needlen) && /* initial match */
5975 (haylen == needlen || haystack[needlen] == ',')
5976 /* either , or EOS follows */
5983 * Add a value to the comma-separated string at the end of the packet.
5984 * If the value is already in the string, don't bother adding it again.
5986 static void ssh2_pkt_addstring_commasep(struct Packet *pkt, const char *data)
5988 if (in_commasep_string(data, (char *)pkt->data + pkt->savedpos,
5989 pkt->length - pkt->savedpos)) return;
5990 if (pkt->length - pkt->savedpos > 0)
5991 ssh_pkt_addstring_str(pkt, ",");
5992 ssh_pkt_addstring_str(pkt, data);
5997 * SSH-2 key creation method.
5998 * (Currently assumes 2 lots of any hash are sufficient to generate
5999 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
6001 #define SSH2_MKKEY_ITERS (2)
6002 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
6003 unsigned char *keyspace)
6005 const struct ssh_hash *h = ssh->kex->hash;
6007 /* First hlen bytes. */
6009 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6010 hash_mpint(h, s, K);
6011 h->bytes(s, H, h->hlen);
6012 h->bytes(s, &chr, 1);
6013 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
6014 h->final(s, keyspace);
6015 /* Next hlen bytes. */
6017 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6018 hash_mpint(h, s, K);
6019 h->bytes(s, H, h->hlen);
6020 h->bytes(s, keyspace, h->hlen);
6021 h->final(s, keyspace + h->hlen);
6025 * Handle the SSH-2 transport layer.
6027 static void do_ssh2_transport(Ssh ssh, void *vin, int inlen,
6028 struct Packet *pktin)
6030 unsigned char *in = (unsigned char *)vin;
6031 struct do_ssh2_transport_state {
6033 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
6034 Bignum p, g, e, f, K;
6037 int kex_init_value, kex_reply_value;
6038 const struct ssh_mac **maclist;
6040 const struct ssh2_cipher *cscipher_tobe;
6041 const struct ssh2_cipher *sccipher_tobe;
6042 const struct ssh_mac *csmac_tobe;
6043 const struct ssh_mac *scmac_tobe;
6044 const struct ssh_compress *cscomp_tobe;
6045 const struct ssh_compress *sccomp_tobe;
6046 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
6047 int hostkeylen, siglen, rsakeylen;
6048 void *hkey; /* actual host key */
6049 void *rsakey; /* for RSA kex */
6050 void *eckey; /* for ECDH kex */
6051 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
6052 int n_preferred_kex;
6053 const struct ssh_kexes *preferred_kex[KEX_MAX];
6054 int n_preferred_ciphers;
6055 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
6056 const struct ssh_compress *preferred_comp;
6057 int userauth_succeeded; /* for delayed compression */
6058 int pending_compression;
6059 int got_session_id, activated_authconn;
6060 struct Packet *pktout;
6065 crState(do_ssh2_transport_state);
6067 assert(!ssh->bare_connection);
6071 s->cscipher_tobe = s->sccipher_tobe = NULL;
6072 s->csmac_tobe = s->scmac_tobe = NULL;
6073 s->cscomp_tobe = s->sccomp_tobe = NULL;
6075 s->got_session_id = s->activated_authconn = FALSE;
6076 s->userauth_succeeded = FALSE;
6077 s->pending_compression = FALSE;
6080 * Be prepared to work around the buggy MAC problem.
6082 if (ssh->remote_bugs & BUG_SSH2_HMAC)
6083 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
6085 s->maclist = macs, s->nmacs = lenof(macs);
6088 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
6093 * Set up the preferred key exchange. (NULL => warn below here)
6095 s->n_preferred_kex = 0;
6096 for (i = 0; i < KEX_MAX; i++) {
6097 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
6099 s->preferred_kex[s->n_preferred_kex++] =
6100 &ssh_diffiehellman_gex;
6103 s->preferred_kex[s->n_preferred_kex++] =
6104 &ssh_diffiehellman_group14;
6107 s->preferred_kex[s->n_preferred_kex++] =
6108 &ssh_diffiehellman_group1;
6111 s->preferred_kex[s->n_preferred_kex++] =
6115 s->preferred_kex[s->n_preferred_kex++] =
6119 /* Flag for later. Don't bother if it's the last in
6121 if (i < KEX_MAX - 1) {
6122 s->preferred_kex[s->n_preferred_kex++] = NULL;
6129 * Set up the preferred ciphers. (NULL => warn below here)
6131 s->n_preferred_ciphers = 0;
6132 for (i = 0; i < CIPHER_MAX; i++) {
6133 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
6134 case CIPHER_BLOWFISH:
6135 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
6138 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
6139 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
6143 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
6146 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
6148 case CIPHER_ARCFOUR:
6149 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
6152 /* Flag for later. Don't bother if it's the last in
6154 if (i < CIPHER_MAX - 1) {
6155 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
6162 * Set up preferred compression.
6164 if (conf_get_int(ssh->conf, CONF_compression))
6165 s->preferred_comp = &ssh_zlib;
6167 s->preferred_comp = &ssh_comp_none;
6170 * Enable queueing of outgoing auth- or connection-layer
6171 * packets while we are in the middle of a key exchange.
6173 ssh->queueing = TRUE;
6176 * Flag that KEX is in progress.
6178 ssh->kex_in_progress = TRUE;
6181 * Construct and send our key exchange packet.
6183 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
6184 for (i = 0; i < 16; i++)
6185 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
6186 /* List key exchange algorithms. */
6187 ssh2_pkt_addstring_start(s->pktout);
6188 for (i = 0; i < s->n_preferred_kex; i++) {
6189 const struct ssh_kexes *k = s->preferred_kex[i];
6190 if (!k) continue; /* warning flag */
6191 for (j = 0; j < k->nkexes; j++)
6192 ssh2_pkt_addstring_commasep(s->pktout, k->list[j]->name);
6194 /* List server host key algorithms. */
6195 if (!s->got_session_id) {
6197 * In the first key exchange, we list all the algorithms
6198 * we're prepared to cope with.
6200 ssh2_pkt_addstring_start(s->pktout);
6201 for (i = 0; i < lenof(hostkey_algs); i++)
6202 ssh2_pkt_addstring_commasep(s->pktout, hostkey_algs[i]->name);
6205 * In subsequent key exchanges, we list only the kex
6206 * algorithm that was selected in the first key exchange,
6207 * so that we keep getting the same host key and hence
6208 * don't have to interrupt the user's session to ask for
6212 ssh2_pkt_addstring(s->pktout, ssh->hostkey->name);
6214 /* List encryption algorithms (client->server then server->client). */
6215 for (k = 0; k < 2; k++) {
6216 ssh2_pkt_addstring_start(s->pktout);
6217 for (i = 0; i < s->n_preferred_ciphers; i++) {
6218 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6219 if (!c) continue; /* warning flag */
6220 for (j = 0; j < c->nciphers; j++)
6221 ssh2_pkt_addstring_commasep(s->pktout, c->list[j]->name);
6224 /* List MAC algorithms (client->server then server->client). */
6225 for (j = 0; j < 2; j++) {
6226 ssh2_pkt_addstring_start(s->pktout);
6227 for (i = 0; i < s->nmacs; i++)
6228 ssh2_pkt_addstring_commasep(s->pktout, s->maclist[i]->name);
6230 /* List client->server compression algorithms,
6231 * then server->client compression algorithms. (We use the
6232 * same set twice.) */
6233 for (j = 0; j < 2; j++) {
6234 ssh2_pkt_addstring_start(s->pktout);
6235 assert(lenof(compressions) > 1);
6236 /* Prefer non-delayed versions */
6237 ssh2_pkt_addstring_commasep(s->pktout, s->preferred_comp->name);
6238 /* We don't even list delayed versions of algorithms until
6239 * they're allowed to be used, to avoid a race. See the end of
6241 if (s->userauth_succeeded && s->preferred_comp->delayed_name)
6242 ssh2_pkt_addstring_commasep(s->pktout,
6243 s->preferred_comp->delayed_name);
6244 for (i = 0; i < lenof(compressions); i++) {
6245 const struct ssh_compress *c = compressions[i];
6246 ssh2_pkt_addstring_commasep(s->pktout, c->name);
6247 if (s->userauth_succeeded && c->delayed_name)
6248 ssh2_pkt_addstring_commasep(s->pktout, c->delayed_name);
6251 /* List client->server languages. Empty list. */
6252 ssh2_pkt_addstring_start(s->pktout);
6253 /* List server->client languages. Empty list. */
6254 ssh2_pkt_addstring_start(s->pktout);
6255 /* First KEX packet does _not_ follow, because we're not that brave. */
6256 ssh2_pkt_addbool(s->pktout, FALSE);
6258 ssh2_pkt_adduint32(s->pktout, 0);
6261 s->our_kexinitlen = s->pktout->length - 5;
6262 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
6263 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
6265 ssh2_pkt_send_noqueue(ssh, s->pktout);
6268 crWaitUntilV(pktin);
6271 * Now examine the other side's KEXINIT to see what we're up
6275 char *str, *preferred;
6278 if (pktin->type != SSH2_MSG_KEXINIT) {
6279 bombout(("expected key exchange packet from server"));
6283 ssh->hostkey = NULL;
6284 s->cscipher_tobe = NULL;
6285 s->sccipher_tobe = NULL;
6286 s->csmac_tobe = NULL;
6287 s->scmac_tobe = NULL;
6288 s->cscomp_tobe = NULL;
6289 s->sccomp_tobe = NULL;
6290 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
6292 pktin->savedpos += 16; /* skip garbage cookie */
6293 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
6295 bombout(("KEXINIT packet was incomplete"));
6300 for (i = 0; i < s->n_preferred_kex; i++) {
6301 const struct ssh_kexes *k = s->preferred_kex[i];
6305 for (j = 0; j < k->nkexes; j++) {
6306 if (!preferred) preferred = k->list[j]->name;
6307 if (in_commasep_string(k->list[j]->name, str, len)) {
6308 ssh->kex = k->list[j];
6317 bombout(("Couldn't agree a key exchange algorithm"
6318 " (available: %.*s)", len, str));
6322 * Note that the server's guess is considered wrong if it doesn't match
6323 * the first algorithm in our list, even if it's still the algorithm
6326 s->guessok = first_in_commasep_string(preferred, str, len);
6327 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
6329 bombout(("KEXINIT packet was incomplete"));
6332 for (i = 0; i < lenof(hostkey_algs); i++) {
6333 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
6334 ssh->hostkey = hostkey_algs[i];
6338 if (!ssh->hostkey) {
6339 bombout(("Couldn't agree a host key algorithm"
6340 " (available: %.*s)", len, str));
6344 s->guessok = s->guessok &&
6345 first_in_commasep_string(hostkey_algs[0]->name, str, len);
6346 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
6348 bombout(("KEXINIT packet was incomplete"));
6351 for (i = 0; i < s->n_preferred_ciphers; i++) {
6352 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6354 s->warn_cscipher = TRUE;
6356 for (j = 0; j < c->nciphers; j++) {
6357 if (in_commasep_string(c->list[j]->name, str, len)) {
6358 s->cscipher_tobe = c->list[j];
6363 if (s->cscipher_tobe)
6366 if (!s->cscipher_tobe) {
6367 bombout(("Couldn't agree a client-to-server cipher"
6368 " (available: %.*s)", len, str));
6372 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
6374 bombout(("KEXINIT packet was incomplete"));
6377 for (i = 0; i < s->n_preferred_ciphers; i++) {
6378 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6380 s->warn_sccipher = TRUE;
6382 for (j = 0; j < c->nciphers; j++) {
6383 if (in_commasep_string(c->list[j]->name, str, len)) {
6384 s->sccipher_tobe = c->list[j];
6389 if (s->sccipher_tobe)
6392 if (!s->sccipher_tobe) {
6393 bombout(("Couldn't agree a server-to-client cipher"
6394 " (available: %.*s)", len, str));
6398 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
6400 bombout(("KEXINIT packet was incomplete"));
6403 for (i = 0; i < s->nmacs; i++) {
6404 if (in_commasep_string(s->maclist[i]->name, str, len)) {
6405 s->csmac_tobe = s->maclist[i];
6409 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
6411 bombout(("KEXINIT packet was incomplete"));
6414 for (i = 0; i < s->nmacs; i++) {
6415 if (in_commasep_string(s->maclist[i]->name, str, len)) {
6416 s->scmac_tobe = s->maclist[i];
6420 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
6422 bombout(("KEXINIT packet was incomplete"));
6425 for (i = 0; i < lenof(compressions) + 1; i++) {
6426 const struct ssh_compress *c =
6427 i == 0 ? s->preferred_comp : compressions[i - 1];
6428 if (in_commasep_string(c->name, str, len)) {
6431 } else if (in_commasep_string(c->delayed_name, str, len)) {
6432 if (s->userauth_succeeded) {
6436 s->pending_compression = TRUE; /* try this later */
6440 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
6442 bombout(("KEXINIT packet was incomplete"));
6445 for (i = 0; i < lenof(compressions) + 1; i++) {
6446 const struct ssh_compress *c =
6447 i == 0 ? s->preferred_comp : compressions[i - 1];
6448 if (in_commasep_string(c->name, str, len)) {
6451 } else if (in_commasep_string(c->delayed_name, str, len)) {
6452 if (s->userauth_succeeded) {
6456 s->pending_compression = TRUE; /* try this later */
6460 if (s->pending_compression) {
6461 logevent("Server supports delayed compression; "
6462 "will try this later");
6464 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
6465 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
6466 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
6468 ssh->exhash = ssh->kex->hash->init();
6469 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
6470 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
6471 hash_string(ssh->kex->hash, ssh->exhash,
6472 s->our_kexinit, s->our_kexinitlen);
6473 sfree(s->our_kexinit);
6474 /* Include the type byte in the hash of server's KEXINIT */
6475 hash_string(ssh->kex->hash, ssh->exhash,
6476 pktin->body - 1, pktin->length + 1);
6479 ssh_set_frozen(ssh, 1);
6480 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
6482 ssh_dialog_callback, ssh);
6483 if (s->dlgret < 0) {
6487 bombout(("Unexpected data from server while"
6488 " waiting for user response"));
6491 } while (pktin || inlen > 0);
6492 s->dlgret = ssh->user_response;
6494 ssh_set_frozen(ssh, 0);
6495 if (s->dlgret == 0) {
6496 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
6502 if (s->warn_cscipher) {
6503 ssh_set_frozen(ssh, 1);
6504 s->dlgret = askalg(ssh->frontend,
6505 "client-to-server cipher",
6506 s->cscipher_tobe->name,
6507 ssh_dialog_callback, ssh);
6508 if (s->dlgret < 0) {
6512 bombout(("Unexpected data from server while"
6513 " waiting for user response"));
6516 } while (pktin || inlen > 0);
6517 s->dlgret = ssh->user_response;
6519 ssh_set_frozen(ssh, 0);
6520 if (s->dlgret == 0) {
6521 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6527 if (s->warn_sccipher) {
6528 ssh_set_frozen(ssh, 1);
6529 s->dlgret = askalg(ssh->frontend,
6530 "server-to-client cipher",
6531 s->sccipher_tobe->name,
6532 ssh_dialog_callback, ssh);
6533 if (s->dlgret < 0) {
6537 bombout(("Unexpected data from server while"
6538 " waiting for user response"));
6541 } while (pktin || inlen > 0);
6542 s->dlgret = ssh->user_response;
6544 ssh_set_frozen(ssh, 0);
6545 if (s->dlgret == 0) {
6546 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6552 if (s->ignorepkt) /* first_kex_packet_follows */
6553 crWaitUntilV(pktin); /* Ignore packet */
6556 if (ssh->kex->main_type == KEXTYPE_DH) {
6558 * Work out the number of bits of key we will need from the
6559 * key exchange. We start with the maximum key length of
6565 csbits = s->cscipher_tobe->keylen;
6566 scbits = s->sccipher_tobe->keylen;
6567 s->nbits = (csbits > scbits ? csbits : scbits);
6569 /* The keys only have hlen-bit entropy, since they're based on
6570 * a hash. So cap the key size at hlen bits. */
6571 if (s->nbits > ssh->kex->hash->hlen * 8)
6572 s->nbits = ssh->kex->hash->hlen * 8;
6575 * If we're doing Diffie-Hellman group exchange, start by
6576 * requesting a group.
6578 if (!ssh->kex->pdata) {
6579 logevent("Doing Diffie-Hellman group exchange");
6580 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
6582 * Work out how big a DH group we will need to allow that
6585 s->pbits = 512 << ((s->nbits - 1) / 64);
6586 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6587 ssh2_pkt_adduint32(s->pktout, s->pbits);
6588 ssh2_pkt_send_noqueue(ssh, s->pktout);
6590 crWaitUntilV(pktin);
6591 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6592 bombout(("expected key exchange group packet from server"));
6595 s->p = ssh2_pkt_getmp(pktin);
6596 s->g = ssh2_pkt_getmp(pktin);
6597 if (!s->p || !s->g) {
6598 bombout(("unable to read mp-ints from incoming group packet"));
6601 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6602 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6603 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6605 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
6606 ssh->kex_ctx = dh_setup_group(ssh->kex);
6607 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6608 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6609 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6610 ssh->kex->groupname);
6613 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6614 ssh->kex->hash->text_name);
6616 * Now generate and send e for Diffie-Hellman.
6618 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6619 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6620 s->pktout = ssh2_pkt_init(s->kex_init_value);
6621 ssh2_pkt_addmp(s->pktout, s->e);
6622 ssh2_pkt_send_noqueue(ssh, s->pktout);
6624 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
6625 crWaitUntilV(pktin);
6626 if (pktin->type != s->kex_reply_value) {
6627 bombout(("expected key exchange reply packet from server"));
6630 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
6631 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6632 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6633 s->f = ssh2_pkt_getmp(pktin);
6635 bombout(("unable to parse key exchange reply packet"));
6638 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6640 s->K = dh_find_K(ssh->kex_ctx, s->f);
6642 /* We assume everything from now on will be quick, and it might
6643 * involve user interaction. */
6644 set_busy_status(ssh->frontend, BUSY_NOT);
6646 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6647 if (!ssh->kex->pdata) {
6648 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
6649 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
6650 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
6652 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
6653 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
6655 dh_cleanup(ssh->kex_ctx);
6657 if (!ssh->kex->pdata) {
6661 } else if (ssh->kex->main_type == KEXTYPE_ECDH) {
6663 logeventf(ssh, "Doing ECDH key exchange with hash %s",
6664 ssh->kex->hash->text_name);
6665 ssh->pkt_kctx = SSH2_PKTCTX_ECDHKEX;
6668 if (!strcmp(ssh->kex->name, "ecdh-sha2-nistp256")) {
6669 s->eckey = ssh_ecdhkex_newkey(ec_p256());
6670 } else if (!strcmp(ssh->kex->name, "ecdh-sha2-nistp384")) {
6671 s->eckey = ssh_ecdhkex_newkey(ec_p384());
6672 } else if (!strcmp(ssh->kex->name, "ecdh-sha2-nistp521")) {
6673 s->eckey = ssh_ecdhkex_newkey(ec_p521());
6676 bombout(("Unable to generate key for ECDH"));
6682 int publicPointLength;
6683 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
6685 ssh_ecdhkex_freekey(s->eckey);
6686 bombout(("Unable to encode public key for ECDH"));
6689 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_ECDH_INIT);
6690 ssh2_pkt_addstring_start(s->pktout);
6691 ssh2_pkt_addstring_data(s->pktout, publicPoint, publicPointLength);
6695 ssh2_pkt_send_noqueue(ssh, s->pktout);
6697 crWaitUntilV(pktin);
6698 if (pktin->type != SSH2_MSG_KEX_ECDH_REPLY) {
6699 ssh_ecdhkex_freekey(s->eckey);
6700 bombout(("expected ECDH reply packet from server"));
6704 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6705 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6706 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6710 int publicPointLength;
6711 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
6713 ssh_ecdhkex_freekey(s->eckey);
6714 bombout(("Unable to encode public key for ECDH hash"));
6717 hash_string(ssh->kex->hash, ssh->exhash,
6718 publicPoint, publicPointLength);
6725 ssh_pkt_getstring(pktin, &keydata, &keylen);
6726 hash_string(ssh->kex->hash, ssh->exhash, keydata, keylen);
6727 s->K = ssh_ecdhkex_getkey(s->eckey, keydata, keylen);
6729 ssh_ecdhkex_freekey(s->eckey);
6730 bombout(("point received in ECDH was not valid"));
6735 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6737 ssh_ecdhkex_freekey(s->eckey);
6739 logeventf(ssh, "Doing RSA key exchange with hash %s",
6740 ssh->kex->hash->text_name);
6741 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
6743 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6746 crWaitUntilV(pktin);
6747 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
6748 bombout(("expected RSA public key packet from server"));
6752 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6753 hash_string(ssh->kex->hash, ssh->exhash,
6754 s->hostkeydata, s->hostkeylen);
6755 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6759 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
6760 s->rsakeydata = snewn(s->rsakeylen, char);
6761 memcpy(s->rsakeydata, keydata, s->rsakeylen);
6764 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
6766 sfree(s->rsakeydata);
6767 bombout(("unable to parse RSA public key from server"));
6771 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
6774 * Next, set up a shared secret K, of precisely KLEN -
6775 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6776 * RSA key modulus and HLEN is the bit length of the hash
6780 int klen = ssh_rsakex_klen(s->rsakey);
6781 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
6783 unsigned char *kstr1, *kstr2, *outstr;
6784 int kstr1len, kstr2len, outstrlen;
6786 s->K = bn_power_2(nbits - 1);
6788 for (i = 0; i < nbits; i++) {
6790 byte = random_byte();
6792 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
6796 * Encode this as an mpint.
6798 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
6799 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
6800 PUT_32BIT(kstr2, kstr1len);
6801 memcpy(kstr2 + 4, kstr1, kstr1len);
6804 * Encrypt it with the given RSA key.
6806 outstrlen = (klen + 7) / 8;
6807 outstr = snewn(outstrlen, unsigned char);
6808 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
6809 outstr, outstrlen, s->rsakey);
6812 * And send it off in a return packet.
6814 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
6815 ssh2_pkt_addstring_start(s->pktout);
6816 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
6817 ssh2_pkt_send_noqueue(ssh, s->pktout);
6819 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
6826 ssh_rsakex_freekey(s->rsakey);
6828 crWaitUntilV(pktin);
6829 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
6830 sfree(s->rsakeydata);
6831 bombout(("expected signature packet from server"));
6835 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6837 sfree(s->rsakeydata);
6840 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
6841 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
6842 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
6844 ssh->kex_ctx = NULL;
6847 debug(("Exchange hash is:\n"));
6848 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
6852 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
6853 (char *)s->exchange_hash,
6854 ssh->kex->hash->hlen)) {
6855 bombout(("Server's host key did not match the signature supplied"));
6859 s->keystr = ssh->hostkey->fmtkey(s->hkey);
6860 if (!s->got_session_id) {
6862 * Authenticate remote host: verify host key. (We've already
6863 * checked the signature of the exchange hash.)
6865 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
6866 logevent("Host key fingerprint is:");
6867 logevent(s->fingerprint);
6868 /* First check against manually configured host keys. */
6869 s->dlgret = verify_ssh_manual_host_key(ssh, s->fingerprint,
6870 ssh->hostkey, s->hkey);
6871 if (s->dlgret == 0) { /* did not match */
6872 bombout(("Host key did not appear in manually configured list"));
6874 } else if (s->dlgret < 0) { /* none configured; use standard handling */
6875 ssh_set_frozen(ssh, 1);
6876 s->dlgret = verify_ssh_host_key(ssh->frontend,
6877 ssh->savedhost, ssh->savedport,
6878 ssh->hostkey->keytype, s->keystr,
6880 ssh_dialog_callback, ssh);
6881 if (s->dlgret < 0) {
6885 bombout(("Unexpected data from server while waiting"
6886 " for user host key response"));
6889 } while (pktin || inlen > 0);
6890 s->dlgret = ssh->user_response;
6892 ssh_set_frozen(ssh, 0);
6893 if (s->dlgret == 0) {
6894 ssh_disconnect(ssh, "Aborted at host key verification", NULL,
6899 sfree(s->fingerprint);
6901 * Save this host key, to check against the one presented in
6902 * subsequent rekeys.
6904 ssh->hostkey_str = s->keystr;
6907 * In a rekey, we never present an interactive host key
6908 * verification request to the user. Instead, we simply
6909 * enforce that the key we're seeing this time is identical to
6910 * the one we saw before.
6912 if (strcmp(ssh->hostkey_str, s->keystr)) {
6913 bombout(("Host key was different in repeat key exchange"));
6918 ssh->hostkey->freekey(s->hkey);
6921 * The exchange hash from the very first key exchange is also
6922 * the session id, used in session key construction and
6925 if (!s->got_session_id) {
6926 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
6927 memcpy(ssh->v2_session_id, s->exchange_hash,
6928 sizeof(s->exchange_hash));
6929 ssh->v2_session_id_len = ssh->kex->hash->hlen;
6930 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
6931 s->got_session_id = TRUE;
6935 * Send SSH2_MSG_NEWKEYS.
6937 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
6938 ssh2_pkt_send_noqueue(ssh, s->pktout);
6939 ssh->outgoing_data_size = 0; /* start counting from here */
6942 * We've sent client NEWKEYS, so create and initialise
6943 * client-to-server session keys.
6945 if (ssh->cs_cipher_ctx)
6946 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6947 ssh->cscipher = s->cscipher_tobe;
6948 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
6950 if (ssh->cs_mac_ctx)
6951 ssh->csmac->free_context(ssh->cs_mac_ctx);
6952 ssh->csmac = s->csmac_tobe;
6953 ssh->cs_mac_ctx = ssh->csmac->make_context();
6955 if (ssh->cs_comp_ctx)
6956 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6957 ssh->cscomp = s->cscomp_tobe;
6958 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
6961 * Set IVs on client-to-server keys. Here we use the exchange
6962 * hash from the _first_ key exchange.
6965 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6966 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6967 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
6968 assert((ssh->cscipher->keylen+7) / 8 <=
6969 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6970 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
6971 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
6972 assert(ssh->cscipher->blksize <=
6973 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6974 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
6975 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
6976 assert(ssh->csmac->len <=
6977 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6978 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
6979 smemclr(keyspace, sizeof(keyspace));
6982 logeventf(ssh, "Initialised %.200s client->server encryption",
6983 ssh->cscipher->text_name);
6984 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
6985 ssh->csmac->text_name);
6986 if (ssh->cscomp->text_name)
6987 logeventf(ssh, "Initialised %s compression",
6988 ssh->cscomp->text_name);
6991 * Now our end of the key exchange is complete, we can send all
6992 * our queued higher-layer packets.
6994 ssh->queueing = FALSE;
6995 ssh2_pkt_queuesend(ssh);
6998 * Expect SSH2_MSG_NEWKEYS from server.
7000 crWaitUntilV(pktin);
7001 if (pktin->type != SSH2_MSG_NEWKEYS) {
7002 bombout(("expected new-keys packet from server"));
7005 ssh->incoming_data_size = 0; /* start counting from here */
7008 * We've seen server NEWKEYS, so create and initialise
7009 * server-to-client session keys.
7011 if (ssh->sc_cipher_ctx)
7012 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7013 ssh->sccipher = s->sccipher_tobe;
7014 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
7016 if (ssh->sc_mac_ctx)
7017 ssh->scmac->free_context(ssh->sc_mac_ctx);
7018 ssh->scmac = s->scmac_tobe;
7019 ssh->sc_mac_ctx = ssh->scmac->make_context();
7021 if (ssh->sc_comp_ctx)
7022 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7023 ssh->sccomp = s->sccomp_tobe;
7024 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
7027 * Set IVs on server-to-client keys. Here we use the exchange
7028 * hash from the _first_ key exchange.
7031 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
7032 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7033 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
7034 assert((ssh->sccipher->keylen+7) / 8 <=
7035 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7036 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
7037 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
7038 assert(ssh->sccipher->blksize <=
7039 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7040 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
7041 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
7042 assert(ssh->scmac->len <=
7043 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7044 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
7045 smemclr(keyspace, sizeof(keyspace));
7047 logeventf(ssh, "Initialised %.200s server->client encryption",
7048 ssh->sccipher->text_name);
7049 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
7050 ssh->scmac->text_name);
7051 if (ssh->sccomp->text_name)
7052 logeventf(ssh, "Initialised %s decompression",
7053 ssh->sccomp->text_name);
7056 * Free shared secret.
7061 * Key exchange is over. Loop straight back round if we have a
7062 * deferred rekey reason.
7064 if (ssh->deferred_rekey_reason) {
7065 logevent(ssh->deferred_rekey_reason);
7067 ssh->deferred_rekey_reason = NULL;
7068 goto begin_key_exchange;
7072 * Otherwise, schedule a timer for our next rekey.
7074 ssh->kex_in_progress = FALSE;
7075 ssh->last_rekey = GETTICKCOUNT();
7076 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
7077 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7081 * Now we're encrypting. Begin returning 1 to the protocol main
7082 * function so that other things can run on top of the
7083 * transport. If we ever see a KEXINIT, we must go back to the
7086 * We _also_ go back to the start if we see pktin==NULL and
7087 * inlen negative, because this is a special signal meaning
7088 * `initiate client-driven rekey', and `in' contains a message
7089 * giving the reason for the rekey.
7091 * inlen==-1 means always initiate a rekey;
7092 * inlen==-2 means that userauth has completed successfully and
7093 * we should consider rekeying (for delayed compression).
7095 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
7096 (!pktin && inlen < 0))) {
7098 if (!ssh->protocol_initial_phase_done) {
7099 ssh->protocol_initial_phase_done = TRUE;
7101 * Allow authconn to initialise itself.
7103 do_ssh2_authconn(ssh, NULL, 0, NULL);
7108 logevent("Server initiated key re-exchange");
7112 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
7113 * delayed compression, if it's available.
7115 * draft-miller-secsh-compression-delayed-00 says that you
7116 * negotiate delayed compression in the first key exchange, and
7117 * both sides start compressing when the server has sent
7118 * USERAUTH_SUCCESS. This has a race condition -- the server
7119 * can't know when the client has seen it, and thus which incoming
7120 * packets it should treat as compressed.
7122 * Instead, we do the initial key exchange without offering the
7123 * delayed methods, but note if the server offers them; when we
7124 * get here, if a delayed method was available that was higher
7125 * on our list than what we got, we initiate a rekey in which we
7126 * _do_ list the delayed methods (and hopefully get it as a
7127 * result). Subsequent rekeys will do the same.
7129 assert(!s->userauth_succeeded); /* should only happen once */
7130 s->userauth_succeeded = TRUE;
7131 if (!s->pending_compression)
7132 /* Can't see any point rekeying. */
7133 goto wait_for_rekey; /* this is utterly horrid */
7134 /* else fall through to rekey... */
7135 s->pending_compression = FALSE;
7138 * Now we've decided to rekey.
7140 * Special case: if the server bug is set that doesn't
7141 * allow rekeying, we give a different log message and
7142 * continue waiting. (If such a server _initiates_ a rekey,
7143 * we process it anyway!)
7145 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
7146 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
7148 /* Reset the counters, so that at least this message doesn't
7149 * hit the event log _too_ often. */
7150 ssh->outgoing_data_size = 0;
7151 ssh->incoming_data_size = 0;
7152 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
7154 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7157 goto wait_for_rekey; /* this is still utterly horrid */
7159 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
7162 goto begin_key_exchange;
7168 * Add data to an SSH-2 channel output buffer.
7170 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
7173 bufchain_add(&c->v.v2.outbuffer, buf, len);
7177 * Attempt to send data on an SSH-2 channel.
7179 static int ssh2_try_send(struct ssh_channel *c)
7182 struct Packet *pktout;
7185 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
7188 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
7189 if ((unsigned)len > c->v.v2.remwindow)
7190 len = c->v.v2.remwindow;
7191 if ((unsigned)len > c->v.v2.remmaxpkt)
7192 len = c->v.v2.remmaxpkt;
7193 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
7194 ssh2_pkt_adduint32(pktout, c->remoteid);
7195 ssh2_pkt_addstring_start(pktout);
7196 ssh2_pkt_addstring_data(pktout, data, len);
7197 ssh2_pkt_send(ssh, pktout);
7198 bufchain_consume(&c->v.v2.outbuffer, len);
7199 c->v.v2.remwindow -= len;
7203 * After having sent as much data as we can, return the amount
7206 ret = bufchain_size(&c->v.v2.outbuffer);
7209 * And if there's no data pending but we need to send an EOF, send
7212 if (!ret && c->pending_eof)
7213 ssh_channel_try_eof(c);
7218 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
7221 if (c->closes & CLOSES_SENT_EOF)
7222 return; /* don't send on channels we've EOFed */
7223 bufsize = ssh2_try_send(c);
7226 case CHAN_MAINSESSION:
7227 /* stdin need not receive an unthrottle
7228 * notification since it will be polled */
7231 x11_unthrottle(c->u.x11.xconn);
7234 /* agent sockets are request/response and need no
7235 * buffer management */
7238 pfd_unthrottle(c->u.pfd.pf);
7244 static int ssh_is_simple(Ssh ssh)
7247 * We use the 'simple' variant of the SSH protocol if we're asked
7248 * to, except not if we're also doing connection-sharing (either
7249 * tunnelling our packets over an upstream or expecting to be
7250 * tunnelled over ourselves), since then the assumption that we
7251 * have only one channel to worry about is not true after all.
7253 return (conf_get_int(ssh->conf, CONF_ssh_simple) &&
7254 !ssh->bare_connection && !ssh->connshare);
7258 * Set up most of a new ssh_channel for SSH-2.
7260 static void ssh2_channel_init(struct ssh_channel *c)
7263 c->localid = alloc_channel_id(ssh);
7265 c->pending_eof = FALSE;
7266 c->throttling_conn = FALSE;
7267 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
7268 ssh_is_simple(ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
7269 c->v.v2.chanreq_head = NULL;
7270 c->v.v2.throttle_state = UNTHROTTLED;
7271 bufchain_init(&c->v.v2.outbuffer);
7275 * Construct the common parts of a CHANNEL_OPEN.
7277 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c, char *type)
7279 struct Packet *pktout;
7281 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7282 ssh2_pkt_addstring(pktout, type);
7283 ssh2_pkt_adduint32(pktout, c->localid);
7284 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7285 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7290 * CHANNEL_FAILURE doesn't come with any indication of what message
7291 * caused it, so we have to keep track of the outstanding
7292 * CHANNEL_REQUESTs ourselves.
7294 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
7295 cchandler_fn_t handler, void *ctx)
7297 struct outstanding_channel_request *ocr =
7298 snew(struct outstanding_channel_request);
7300 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7301 ocr->handler = handler;
7304 if (!c->v.v2.chanreq_head)
7305 c->v.v2.chanreq_head = ocr;
7307 c->v.v2.chanreq_tail->next = ocr;
7308 c->v.v2.chanreq_tail = ocr;
7312 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
7313 * NULL then a reply will be requested and the handler will be called
7314 * when it arrives. The returned packet is ready to have any
7315 * request-specific data added and be sent. Note that if a handler is
7316 * provided, it's essential that the request actually be sent.
7318 * The handler will usually be passed the response packet in pktin. If
7319 * pktin is NULL, this means that no reply will ever be forthcoming
7320 * (e.g. because the entire connection is being destroyed, or because
7321 * the server initiated channel closure before we saw the response)
7322 * and the handler should free any storage it's holding.
7324 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c, char *type,
7325 cchandler_fn_t handler, void *ctx)
7327 struct Packet *pktout;
7329 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7330 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7331 ssh2_pkt_adduint32(pktout, c->remoteid);
7332 ssh2_pkt_addstring(pktout, type);
7333 ssh2_pkt_addbool(pktout, handler != NULL);
7334 if (handler != NULL)
7335 ssh2_queue_chanreq_handler(c, handler, ctx);
7340 * Potentially enlarge the window on an SSH-2 channel.
7342 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
7344 static void ssh2_set_window(struct ssh_channel *c, int newwin)
7349 * Never send WINDOW_ADJUST for a channel that the remote side has
7350 * already sent EOF on; there's no point, since it won't be
7351 * sending any more data anyway. Ditto if _we've_ already sent
7354 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
7358 * Also, never widen the window for an X11 channel when we're
7359 * still waiting to see its initial auth and may yet hand it off
7362 if (c->type == CHAN_X11 && c->u.x11.initial)
7366 * If the remote end has a habit of ignoring maxpkt, limit the
7367 * window so that it has no choice (assuming it doesn't ignore the
7370 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
7371 newwin = OUR_V2_MAXPKT;
7374 * Only send a WINDOW_ADJUST if there's significantly more window
7375 * available than the other end thinks there is. This saves us
7376 * sending a WINDOW_ADJUST for every character in a shell session.
7378 * "Significant" is arbitrarily defined as half the window size.
7380 if (newwin / 2 >= c->v.v2.locwindow) {
7381 struct Packet *pktout;
7385 * In order to keep track of how much window the client
7386 * actually has available, we'd like it to acknowledge each
7387 * WINDOW_ADJUST. We can't do that directly, so we accompany
7388 * it with a CHANNEL_REQUEST that has to be acknowledged.
7390 * This is only necessary if we're opening the window wide.
7391 * If we're not, then throughput is being constrained by
7392 * something other than the maximum window size anyway.
7394 if (newwin == c->v.v2.locmaxwin &&
7395 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
7396 up = snew(unsigned);
7397 *up = newwin - c->v.v2.locwindow;
7398 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
7399 ssh2_handle_winadj_response, up);
7400 ssh2_pkt_send(ssh, pktout);
7402 if (c->v.v2.throttle_state != UNTHROTTLED)
7403 c->v.v2.throttle_state = UNTHROTTLING;
7405 /* Pretend the WINDOW_ADJUST was acked immediately. */
7406 c->v.v2.remlocwin = newwin;
7407 c->v.v2.throttle_state = THROTTLED;
7409 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7410 ssh2_pkt_adduint32(pktout, c->remoteid);
7411 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
7412 ssh2_pkt_send(ssh, pktout);
7413 c->v.v2.locwindow = newwin;
7418 * Find the channel associated with a message. If there's no channel,
7419 * or it's not properly open, make a noise about it and return NULL.
7421 static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
7423 unsigned localid = ssh_pkt_getuint32(pktin);
7424 struct ssh_channel *c;
7426 c = find234(ssh->channels, &localid, ssh_channelfind);
7428 (c->type != CHAN_SHARING && c->halfopen &&
7429 pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
7430 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
7431 char *buf = dupprintf("Received %s for %s channel %u",
7432 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
7434 c ? "half-open" : "nonexistent", localid);
7435 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
7442 static void ssh2_handle_winadj_response(struct ssh_channel *c,
7443 struct Packet *pktin, void *ctx)
7445 unsigned *sizep = ctx;
7448 * Winadj responses should always be failures. However, at least
7449 * one server ("boks_sshd") is known to return SUCCESS for channel
7450 * requests it's never heard of, such as "winadj@putty". Raised
7451 * with foxt.com as bug 090916-090424, but for the sake of a quiet
7452 * life, we don't worry about what kind of response we got.
7455 c->v.v2.remlocwin += *sizep;
7458 * winadj messages are only sent when the window is fully open, so
7459 * if we get an ack of one, we know any pending unthrottle is
7462 if (c->v.v2.throttle_state == UNTHROTTLING)
7463 c->v.v2.throttle_state = UNTHROTTLED;
7466 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
7468 struct ssh_channel *c = ssh2_channel_msg(ssh, pktin);
7469 struct outstanding_channel_request *ocr;
7472 if (c->type == CHAN_SHARING) {
7473 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7474 pktin->body, pktin->length);
7477 ocr = c->v.v2.chanreq_head;
7479 ssh2_msg_unexpected(ssh, pktin);
7482 ocr->handler(c, pktin, ocr->ctx);
7483 c->v.v2.chanreq_head = ocr->next;
7486 * We may now initiate channel-closing procedures, if that
7487 * CHANNEL_REQUEST was the last thing outstanding before we send
7490 ssh2_channel_check_close(c);
7493 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
7495 struct ssh_channel *c;
7496 c = ssh2_channel_msg(ssh, pktin);
7499 if (c->type == CHAN_SHARING) {
7500 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7501 pktin->body, pktin->length);
7504 if (!(c->closes & CLOSES_SENT_EOF)) {
7505 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
7506 ssh2_try_send_and_unthrottle(ssh, c);
7510 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
7514 struct ssh_channel *c;
7515 c = ssh2_channel_msg(ssh, pktin);
7518 if (c->type == CHAN_SHARING) {
7519 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7520 pktin->body, pktin->length);
7523 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
7524 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
7525 return; /* extended but not stderr */
7526 ssh_pkt_getstring(pktin, &data, &length);
7529 c->v.v2.locwindow -= length;
7530 c->v.v2.remlocwin -= length;
7532 case CHAN_MAINSESSION:
7534 from_backend(ssh->frontend, pktin->type ==
7535 SSH2_MSG_CHANNEL_EXTENDED_DATA,
7539 bufsize = x11_send(c->u.x11.xconn, data, length);
7542 bufsize = pfd_send(c->u.pfd.pf, data, length);
7545 while (length > 0) {
7546 if (c->u.a.lensofar < 4) {
7547 unsigned int l = min(4 - c->u.a.lensofar,
7549 memcpy(c->u.a.msglen + c->u.a.lensofar,
7553 c->u.a.lensofar += l;
7555 if (c->u.a.lensofar == 4) {
7557 4 + GET_32BIT(c->u.a.msglen);
7558 c->u.a.message = snewn(c->u.a.totallen,
7560 memcpy(c->u.a.message, c->u.a.msglen, 4);
7562 if (c->u.a.lensofar >= 4 && length > 0) {
7564 min(c->u.a.totallen - c->u.a.lensofar,
7566 memcpy(c->u.a.message + c->u.a.lensofar,
7570 c->u.a.lensofar += l;
7572 if (c->u.a.lensofar == c->u.a.totallen) {
7575 c->u.a.outstanding_requests++;
7576 if (agent_query(c->u.a.message,
7579 ssh_agentf_callback, c))
7580 ssh_agentf_callback(c, reply, replylen);
7581 sfree(c->u.a.message);
7582 c->u.a.message = NULL;
7583 c->u.a.lensofar = 0;
7590 * If it looks like the remote end hit the end of its window,
7591 * and we didn't want it to do that, think about using a
7594 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
7595 c->v.v2.locmaxwin < 0x40000000)
7596 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
7598 * If we are not buffering too much data,
7599 * enlarge the window again at the remote side.
7600 * If we are buffering too much, we may still
7601 * need to adjust the window if the server's
7604 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
7605 c->v.v2.locmaxwin - bufsize : 0);
7607 * If we're either buffering way too much data, or if we're
7608 * buffering anything at all and we're in "simple" mode,
7609 * throttle the whole channel.
7611 if ((bufsize > c->v.v2.locmaxwin || (ssh_is_simple(ssh) && bufsize>0))
7612 && !c->throttling_conn) {
7613 c->throttling_conn = 1;
7614 ssh_throttle_conn(ssh, +1);
7619 static void ssh_check_termination(Ssh ssh)
7621 if (ssh->version == 2 &&
7622 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
7623 count234(ssh->channels) == 0 &&
7624 !(ssh->connshare && share_ndownstreams(ssh->connshare) > 0)) {
7626 * We used to send SSH_MSG_DISCONNECT here, because I'd
7627 * believed that _every_ conforming SSH-2 connection had to
7628 * end with a disconnect being sent by at least one side;
7629 * apparently I was wrong and it's perfectly OK to
7630 * unceremoniously slam the connection shut when you're done,
7631 * and indeed OpenSSH feels this is more polite than sending a
7632 * DISCONNECT. So now we don't.
7634 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
7638 void ssh_sharing_downstream_connected(Ssh ssh, unsigned id)
7640 logeventf(ssh, "Connection sharing downstream #%u connected", id);
7643 void ssh_sharing_downstream_disconnected(Ssh ssh, unsigned id)
7645 logeventf(ssh, "Connection sharing downstream #%u disconnected", id);
7646 ssh_check_termination(ssh);
7649 void ssh_sharing_logf(Ssh ssh, unsigned id, const char *logfmt, ...)
7654 va_start(ap, logfmt);
7655 buf = dupvprintf(logfmt, ap);
7658 logeventf(ssh, "Connection sharing downstream #%u: %s", id, buf);
7660 logeventf(ssh, "Connection sharing: %s", buf);
7664 static void ssh_channel_destroy(struct ssh_channel *c)
7669 case CHAN_MAINSESSION:
7670 ssh->mainchan = NULL;
7671 update_specials_menu(ssh->frontend);
7674 if (c->u.x11.xconn != NULL)
7675 x11_close(c->u.x11.xconn);
7676 logevent("Forwarded X11 connection terminated");
7679 sfree(c->u.a.message);
7682 if (c->u.pfd.pf != NULL)
7683 pfd_close(c->u.pfd.pf);
7684 logevent("Forwarded port closed");
7688 del234(ssh->channels, c);
7689 if (ssh->version == 2) {
7690 bufchain_clear(&c->v.v2.outbuffer);
7691 assert(c->v.v2.chanreq_head == NULL);
7696 * If that was the last channel left open, we might need to
7699 ssh_check_termination(ssh);
7702 static void ssh2_channel_check_close(struct ssh_channel *c)
7705 struct Packet *pktout;
7709 * If we've sent out our own CHANNEL_OPEN but not yet seen
7710 * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
7711 * it's too early to be sending close messages of any kind.
7716 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
7717 c->type == CHAN_ZOMBIE) &&
7718 !c->v.v2.chanreq_head &&
7719 !(c->closes & CLOSES_SENT_CLOSE)) {
7721 * We have both sent and received EOF (or the channel is a
7722 * zombie), and we have no outstanding channel requests, which
7723 * means the channel is in final wind-up. But we haven't sent
7724 * CLOSE, so let's do so now.
7726 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
7727 ssh2_pkt_adduint32(pktout, c->remoteid);
7728 ssh2_pkt_send(ssh, pktout);
7729 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
7732 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
7733 assert(c->v.v2.chanreq_head == NULL);
7735 * We have both sent and received CLOSE, which means we're
7736 * completely done with the channel.
7738 ssh_channel_destroy(c);
7742 static void ssh2_channel_got_eof(struct ssh_channel *c)
7744 if (c->closes & CLOSES_RCVD_EOF)
7745 return; /* already seen EOF */
7746 c->closes |= CLOSES_RCVD_EOF;
7748 if (c->type == CHAN_X11) {
7749 x11_send_eof(c->u.x11.xconn);
7750 } else if (c->type == CHAN_AGENT) {
7751 if (c->u.a.outstanding_requests == 0) {
7752 /* Manufacture an outgoing EOF in response to the incoming one. */
7753 sshfwd_write_eof(c);
7755 } else if (c->type == CHAN_SOCKDATA) {
7756 pfd_send_eof(c->u.pfd.pf);
7757 } else if (c->type == CHAN_MAINSESSION) {
7760 if (!ssh->sent_console_eof &&
7761 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
7763 * Either from_backend_eof told us that the front end
7764 * wants us to close the outgoing side of the connection
7765 * as soon as we see EOF from the far end, or else we've
7766 * unilaterally decided to do that because we've allocated
7767 * a remote pty and hence EOF isn't a particularly
7768 * meaningful concept.
7770 sshfwd_write_eof(c);
7772 ssh->sent_console_eof = TRUE;
7775 ssh2_channel_check_close(c);
7778 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
7780 struct ssh_channel *c;
7782 c = ssh2_channel_msg(ssh, pktin);
7785 if (c->type == CHAN_SHARING) {
7786 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7787 pktin->body, pktin->length);
7790 ssh2_channel_got_eof(c);
7793 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
7795 struct ssh_channel *c;
7797 c = ssh2_channel_msg(ssh, pktin);
7800 if (c->type == CHAN_SHARING) {
7801 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7802 pktin->body, pktin->length);
7807 * When we receive CLOSE on a channel, we assume it comes with an
7808 * implied EOF if we haven't seen EOF yet.
7810 ssh2_channel_got_eof(c);
7812 if (!(ssh->remote_bugs & BUG_SENDS_LATE_REQUEST_REPLY)) {
7814 * It also means we stop expecting to see replies to any
7815 * outstanding channel requests, so clean those up too.
7816 * (ssh_chanreq_init will enforce by assertion that we don't
7817 * subsequently put anything back on this list.)
7819 while (c->v.v2.chanreq_head) {
7820 struct outstanding_channel_request *ocr = c->v.v2.chanreq_head;
7821 ocr->handler(c, NULL, ocr->ctx);
7822 c->v.v2.chanreq_head = ocr->next;
7828 * And we also send an outgoing EOF, if we haven't already, on the
7829 * assumption that CLOSE is a pretty forceful announcement that
7830 * the remote side is doing away with the entire channel. (If it
7831 * had wanted to send us EOF and continue receiving data from us,
7832 * it would have just sent CHANNEL_EOF.)
7834 if (!(c->closes & CLOSES_SENT_EOF)) {
7836 * Make sure we don't read any more from whatever our local
7837 * data source is for this channel.
7840 case CHAN_MAINSESSION:
7841 ssh->send_ok = 0; /* stop trying to read from stdin */
7844 x11_override_throttle(c->u.x11.xconn, 1);
7847 pfd_override_throttle(c->u.pfd.pf, 1);
7852 * Abandon any buffered data we still wanted to send to this
7853 * channel. Receiving a CHANNEL_CLOSE is an indication that
7854 * the server really wants to get on and _destroy_ this
7855 * channel, and it isn't going to send us any further
7856 * WINDOW_ADJUSTs to permit us to send pending stuff.
7858 bufchain_clear(&c->v.v2.outbuffer);
7861 * Send outgoing EOF.
7863 sshfwd_write_eof(c);
7867 * Now process the actual close.
7869 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
7870 c->closes |= CLOSES_RCVD_CLOSE;
7871 ssh2_channel_check_close(c);
7875 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
7877 struct ssh_channel *c;
7879 c = ssh2_channel_msg(ssh, pktin);
7882 if (c->type == CHAN_SHARING) {
7883 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7884 pktin->body, pktin->length);
7887 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7888 c->remoteid = ssh_pkt_getuint32(pktin);
7889 c->halfopen = FALSE;
7890 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7891 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7893 if (c->type == CHAN_SOCKDATA_DORMANT) {
7894 c->type = CHAN_SOCKDATA;
7896 pfd_confirm(c->u.pfd.pf);
7897 } else if (c->type == CHAN_ZOMBIE) {
7899 * This case can occur if a local socket error occurred
7900 * between us sending out CHANNEL_OPEN and receiving
7901 * OPEN_CONFIRMATION. In this case, all we can do is
7902 * immediately initiate close proceedings now that we know the
7903 * server's id to put in the close message.
7905 ssh2_channel_check_close(c);
7908 * We never expect to receive OPEN_CONFIRMATION for any
7909 * *other* channel type (since only local-to-remote port
7910 * forwardings cause us to send CHANNEL_OPEN after the main
7911 * channel is live - all other auxiliary channel types are
7912 * initiated from the server end). It's safe to enforce this
7913 * by assertion rather than by ssh_disconnect, because the
7914 * real point is that we never constructed a half-open channel
7915 * structure in the first place with any type other than the
7918 assert(!"Funny channel type in ssh2_msg_channel_open_confirmation");
7922 ssh_channel_try_eof(c); /* in case we had a pending EOF */
7925 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
7927 static const char *const reasons[] = {
7928 "<unknown reason code>",
7929 "Administratively prohibited",
7931 "Unknown channel type",
7932 "Resource shortage",
7934 unsigned reason_code;
7935 char *reason_string;
7937 struct ssh_channel *c;
7939 c = ssh2_channel_msg(ssh, pktin);
7942 if (c->type == CHAN_SHARING) {
7943 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7944 pktin->body, pktin->length);
7947 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7949 if (c->type == CHAN_SOCKDATA_DORMANT) {
7950 reason_code = ssh_pkt_getuint32(pktin);
7951 if (reason_code >= lenof(reasons))
7952 reason_code = 0; /* ensure reasons[reason_code] in range */
7953 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
7954 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
7955 reasons[reason_code], reason_length, reason_string);
7957 pfd_close(c->u.pfd.pf);
7958 } else if (c->type == CHAN_ZOMBIE) {
7960 * This case can occur if a local socket error occurred
7961 * between us sending out CHANNEL_OPEN and receiving
7962 * OPEN_FAILURE. In this case, we need do nothing except allow
7963 * the code below to throw the half-open channel away.
7967 * We never expect to receive OPEN_FAILURE for any *other*
7968 * channel type (since only local-to-remote port forwardings
7969 * cause us to send CHANNEL_OPEN after the main channel is
7970 * live - all other auxiliary channel types are initiated from
7971 * the server end). It's safe to enforce this by assertion
7972 * rather than by ssh_disconnect, because the real point is
7973 * that we never constructed a half-open channel structure in
7974 * the first place with any type other than the above.
7976 assert(!"Funny channel type in ssh2_msg_channel_open_failure");
7979 del234(ssh->channels, c);
7983 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
7986 int typelen, want_reply;
7987 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
7988 struct ssh_channel *c;
7989 struct Packet *pktout;
7991 c = ssh2_channel_msg(ssh, pktin);
7994 if (c->type == CHAN_SHARING) {
7995 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7996 pktin->body, pktin->length);
7999 ssh_pkt_getstring(pktin, &type, &typelen);
8000 want_reply = ssh2_pkt_getbool(pktin);
8002 if (c->closes & CLOSES_SENT_CLOSE) {
8004 * We don't reply to channel requests after we've sent
8005 * CHANNEL_CLOSE for the channel, because our reply might
8006 * cross in the network with the other side's CHANNEL_CLOSE
8007 * and arrive after they have wound the channel up completely.
8013 * Having got the channel number, we now look at
8014 * the request type string to see if it's something
8017 if (c == ssh->mainchan) {
8019 * We recognise "exit-status" and "exit-signal" on
8020 * the primary channel.
8022 if (typelen == 11 &&
8023 !memcmp(type, "exit-status", 11)) {
8025 ssh->exitcode = ssh_pkt_getuint32(pktin);
8026 logeventf(ssh, "Server sent command exit status %d",
8028 reply = SSH2_MSG_CHANNEL_SUCCESS;
8030 } else if (typelen == 11 &&
8031 !memcmp(type, "exit-signal", 11)) {
8033 int is_plausible = TRUE, is_int = FALSE;
8034 char *fmt_sig = "", *fmt_msg = "";
8036 int msglen = 0, core = FALSE;
8037 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
8038 * provide an `int' for the signal, despite its
8039 * having been a `string' in the drafts of RFC 4254 since at
8040 * least 2001. (Fixed in session.c 1.147.) Try to
8041 * infer which we can safely parse it as. */
8043 unsigned char *p = pktin->body +
8045 long len = pktin->length - pktin->savedpos;
8046 unsigned long num = GET_32BIT(p); /* what is it? */
8047 /* If it's 0, it hardly matters; assume string */
8051 int maybe_int = FALSE, maybe_str = FALSE;
8052 #define CHECK_HYPOTHESIS(offset, result) \
8055 int q = toint(offset); \
8056 if (q >= 0 && q+4 <= len) { \
8057 q = toint(q + 4 + GET_32BIT(p+q)); \
8058 if (q >= 0 && q+4 <= len && \
8059 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
8064 CHECK_HYPOTHESIS(4+1, maybe_int);
8065 CHECK_HYPOTHESIS(4+num+1, maybe_str);
8066 #undef CHECK_HYPOTHESIS
8067 if (maybe_int && !maybe_str)
8069 else if (!maybe_int && maybe_str)
8072 /* Crikey. Either or neither. Panic. */
8073 is_plausible = FALSE;
8076 ssh->exitcode = 128; /* means `unknown signal' */
8079 /* Old non-standard OpenSSH. */
8080 int signum = ssh_pkt_getuint32(pktin);
8081 fmt_sig = dupprintf(" %d", signum);
8082 ssh->exitcode = 128 + signum;
8084 /* As per RFC 4254. */
8087 ssh_pkt_getstring(pktin, &sig, &siglen);
8088 /* Signal name isn't supposed to be blank, but
8089 * let's cope gracefully if it is. */
8091 fmt_sig = dupprintf(" \"%.*s\"",
8096 * Really hideous method of translating the
8097 * signal description back into a locally
8098 * meaningful number.
8103 #define TRANSLATE_SIGNAL(s) \
8104 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
8105 ssh->exitcode = 128 + SIG ## s
8107 TRANSLATE_SIGNAL(ABRT);
8110 TRANSLATE_SIGNAL(ALRM);
8113 TRANSLATE_SIGNAL(FPE);
8116 TRANSLATE_SIGNAL(HUP);
8119 TRANSLATE_SIGNAL(ILL);
8122 TRANSLATE_SIGNAL(INT);
8125 TRANSLATE_SIGNAL(KILL);
8128 TRANSLATE_SIGNAL(PIPE);
8131 TRANSLATE_SIGNAL(QUIT);
8134 TRANSLATE_SIGNAL(SEGV);
8137 TRANSLATE_SIGNAL(TERM);
8140 TRANSLATE_SIGNAL(USR1);
8143 TRANSLATE_SIGNAL(USR2);
8145 #undef TRANSLATE_SIGNAL
8147 ssh->exitcode = 128;
8149 core = ssh2_pkt_getbool(pktin);
8150 ssh_pkt_getstring(pktin, &msg, &msglen);
8152 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
8154 /* ignore lang tag */
8155 } /* else don't attempt to parse */
8156 logeventf(ssh, "Server exited on signal%s%s%s",
8157 fmt_sig, core ? " (core dumped)" : "",
8159 if (*fmt_sig) sfree(fmt_sig);
8160 if (*fmt_msg) sfree(fmt_msg);
8161 reply = SSH2_MSG_CHANNEL_SUCCESS;
8166 * This is a channel request we don't know
8167 * about, so we now either ignore the request
8168 * or respond with CHANNEL_FAILURE, depending
8171 reply = SSH2_MSG_CHANNEL_FAILURE;
8174 pktout = ssh2_pkt_init(reply);
8175 ssh2_pkt_adduint32(pktout, c->remoteid);
8176 ssh2_pkt_send(ssh, pktout);
8180 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
8183 int typelen, want_reply;
8184 struct Packet *pktout;
8186 ssh_pkt_getstring(pktin, &type, &typelen);
8187 want_reply = ssh2_pkt_getbool(pktin);
8190 * We currently don't support any global requests
8191 * at all, so we either ignore the request or
8192 * respond with REQUEST_FAILURE, depending on
8196 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
8197 ssh2_pkt_send(ssh, pktout);
8201 struct X11FakeAuth *ssh_sharing_add_x11_display(Ssh ssh, int authtype,
8205 struct X11FakeAuth *auth;
8208 * Make up a new set of fake X11 auth data, and add it to the tree
8209 * of currently valid ones with an indication of the sharing
8210 * context that it's relevant to.
8212 auth = x11_invent_fake_auth(ssh->x11authtree, authtype);
8213 auth->share_cs = share_cs;
8214 auth->share_chan = share_chan;
8219 void ssh_sharing_remove_x11_display(Ssh ssh, struct X11FakeAuth *auth)
8221 del234(ssh->x11authtree, auth);
8222 x11_free_fake_auth(auth);
8225 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
8233 struct ssh_channel *c;
8234 unsigned remid, winsize, pktsize;
8235 unsigned our_winsize_override = 0;
8236 struct Packet *pktout;
8238 ssh_pkt_getstring(pktin, &type, &typelen);
8239 c = snew(struct ssh_channel);
8242 remid = ssh_pkt_getuint32(pktin);
8243 winsize = ssh_pkt_getuint32(pktin);
8244 pktsize = ssh_pkt_getuint32(pktin);
8246 if (typelen == 3 && !memcmp(type, "x11", 3)) {
8249 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8250 addrstr = snewn(peeraddrlen+1, char);
8251 memcpy(addrstr, peeraddr, peeraddrlen);
8252 addrstr[peeraddrlen] = '\0';
8253 peerport = ssh_pkt_getuint32(pktin);
8255 logeventf(ssh, "Received X11 connect request from %s:%d",
8258 if (!ssh->X11_fwd_enabled && !ssh->connshare)
8259 error = "X11 forwarding is not enabled";
8261 c->u.x11.xconn = x11_init(ssh->x11authtree, c,
8264 c->u.x11.initial = TRUE;
8267 * If we are a connection-sharing upstream, then we should
8268 * initially present a very small window, adequate to take
8269 * the X11 initial authorisation packet but not much more.
8270 * Downstream will then present us a larger window (by
8271 * fiat of the connection-sharing protocol) and we can
8272 * guarantee to send a positive-valued WINDOW_ADJUST.
8275 our_winsize_override = 128;
8277 logevent("Opened X11 forward channel");
8281 } else if (typelen == 15 &&
8282 !memcmp(type, "forwarded-tcpip", 15)) {
8283 struct ssh_rportfwd pf, *realpf;
8286 ssh_pkt_getstring(pktin, &shost, &shostlen);/* skip address */
8287 pf.shost = dupprintf("%.*s", shostlen, shost);
8288 pf.sport = ssh_pkt_getuint32(pktin);
8289 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8290 peerport = ssh_pkt_getuint32(pktin);
8291 realpf = find234(ssh->rportfwds, &pf, NULL);
8292 logeventf(ssh, "Received remote port %s:%d open request "
8293 "from %s:%d", pf.shost, pf.sport, peeraddr, peerport);
8296 if (realpf == NULL) {
8297 error = "Remote port is not recognised";
8301 if (realpf->share_ctx) {
8303 * This port forwarding is on behalf of a
8304 * connection-sharing downstream, so abandon our own
8305 * channel-open procedure and just pass the message on
8308 share_got_pkt_from_server(realpf->share_ctx, pktin->type,
8309 pktin->body, pktin->length);
8314 err = pfd_connect(&c->u.pfd.pf, realpf->dhost, realpf->dport,
8315 c, ssh->conf, realpf->pfrec->addressfamily);
8316 logeventf(ssh, "Attempting to forward remote port to "
8317 "%s:%d", realpf->dhost, realpf->dport);
8319 logeventf(ssh, "Port open failed: %s", err);
8321 error = "Port open failed";
8323 logevent("Forwarded port opened successfully");
8324 c->type = CHAN_SOCKDATA;
8327 } else if (typelen == 22 &&
8328 !memcmp(type, "auth-agent@openssh.com", 22)) {
8329 if (!ssh->agentfwd_enabled)
8330 error = "Agent forwarding is not enabled";
8332 c->type = CHAN_AGENT; /* identify channel type */
8333 c->u.a.lensofar = 0;
8334 c->u.a.message = NULL;
8335 c->u.a.outstanding_requests = 0;
8338 error = "Unsupported channel type requested";
8341 c->remoteid = remid;
8342 c->halfopen = FALSE;
8344 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
8345 ssh2_pkt_adduint32(pktout, c->remoteid);
8346 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
8347 ssh2_pkt_addstring(pktout, error);
8348 ssh2_pkt_addstring(pktout, "en"); /* language tag */
8349 ssh2_pkt_send(ssh, pktout);
8350 logeventf(ssh, "Rejected channel open: %s", error);
8353 ssh2_channel_init(c);
8354 c->v.v2.remwindow = winsize;
8355 c->v.v2.remmaxpkt = pktsize;
8356 if (our_winsize_override) {
8357 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
8358 our_winsize_override;
8360 add234(ssh->channels, c);
8361 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
8362 ssh2_pkt_adduint32(pktout, c->remoteid);
8363 ssh2_pkt_adduint32(pktout, c->localid);
8364 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
8365 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8366 ssh2_pkt_send(ssh, pktout);
8370 void sshfwd_x11_sharing_handover(struct ssh_channel *c,
8371 void *share_cs, void *share_chan,
8372 const char *peer_addr, int peer_port,
8373 int endian, int protomajor, int protominor,
8374 const void *initial_data, int initial_len)
8377 * This function is called when we've just discovered that an X
8378 * forwarding channel on which we'd been handling the initial auth
8379 * ourselves turns out to be destined for a connection-sharing
8380 * downstream. So we turn the channel into a CHAN_SHARING, meaning
8381 * that we completely stop tracking windows and buffering data and
8382 * just pass more or less unmodified SSH messages back and forth.
8384 c->type = CHAN_SHARING;
8385 c->u.sharing.ctx = share_cs;
8386 share_setup_x11_channel(share_cs, share_chan,
8387 c->localid, c->remoteid, c->v.v2.remwindow,
8388 c->v.v2.remmaxpkt, c->v.v2.locwindow,
8389 peer_addr, peer_port, endian,
8390 protomajor, protominor,
8391 initial_data, initial_len);
8394 void sshfwd_x11_is_local(struct ssh_channel *c)
8397 * This function is called when we've just discovered that an X
8398 * forwarding channel is _not_ destined for a connection-sharing
8399 * downstream but we're going to handle it ourselves. We stop
8400 * presenting a cautiously small window and go into ordinary data
8403 c->u.x11.initial = FALSE;
8404 ssh2_set_window(c, ssh_is_simple(c->ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE);
8408 * Buffer banner messages for later display at some convenient point,
8409 * if we're going to display them.
8411 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
8413 /* Arbitrary limit to prevent unbounded inflation of buffer */
8414 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
8415 bufchain_size(&ssh->banner) <= 131072) {
8416 char *banner = NULL;
8418 ssh_pkt_getstring(pktin, &banner, &size);
8420 bufchain_add(&ssh->banner, banner, size);
8424 /* Helper function to deal with sending tty modes for "pty-req" */
8425 static void ssh2_send_ttymode(void *data, char *mode, char *val)
8427 struct Packet *pktout = (struct Packet *)data;
8429 unsigned int arg = 0;
8430 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
8431 if (i == lenof(ssh_ttymodes)) return;
8432 switch (ssh_ttymodes[i].type) {
8434 arg = ssh_tty_parse_specchar(val);
8437 arg = ssh_tty_parse_boolean(val);
8440 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
8441 ssh2_pkt_adduint32(pktout, arg);
8444 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
8447 struct ssh2_setup_x11_state {
8451 struct Packet *pktout;
8452 crStateP(ssh2_setup_x11_state, ctx);
8456 logevent("Requesting X11 forwarding");
8457 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
8459 ssh2_pkt_addbool(pktout, 0); /* many connections */
8460 ssh2_pkt_addstring(pktout, ssh->x11auth->protoname);
8461 ssh2_pkt_addstring(pktout, ssh->x11auth->datastring);
8462 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
8463 ssh2_pkt_send(ssh, pktout);
8465 /* Wait to be called back with either a response packet, or NULL
8466 * meaning clean up and free our data */
8470 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8471 logevent("X11 forwarding enabled");
8472 ssh->X11_fwd_enabled = TRUE;
8474 logevent("X11 forwarding refused");
8480 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
8483 struct ssh2_setup_agent_state {
8487 struct Packet *pktout;
8488 crStateP(ssh2_setup_agent_state, ctx);
8492 logevent("Requesting OpenSSH-style agent forwarding");
8493 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
8494 ssh2_setup_agent, s);
8495 ssh2_pkt_send(ssh, pktout);
8497 /* Wait to be called back with either a response packet, or NULL
8498 * meaning clean up and free our data */
8502 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8503 logevent("Agent forwarding enabled");
8504 ssh->agentfwd_enabled = TRUE;
8506 logevent("Agent forwarding refused");
8512 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
8515 struct ssh2_setup_pty_state {
8519 struct Packet *pktout;
8520 crStateP(ssh2_setup_pty_state, ctx);
8524 /* Unpick the terminal-speed string. */
8525 /* XXX perhaps we should allow no speeds to be sent. */
8526 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
8527 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
8528 /* Build the pty request. */
8529 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
8531 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
8532 ssh2_pkt_adduint32(pktout, ssh->term_width);
8533 ssh2_pkt_adduint32(pktout, ssh->term_height);
8534 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
8535 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
8536 ssh2_pkt_addstring_start(pktout);
8537 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
8538 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
8539 ssh2_pkt_adduint32(pktout, ssh->ispeed);
8540 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
8541 ssh2_pkt_adduint32(pktout, ssh->ospeed);
8542 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
8543 ssh2_pkt_send(ssh, pktout);
8544 ssh->state = SSH_STATE_INTERMED;
8546 /* Wait to be called back with either a response packet, or NULL
8547 * meaning clean up and free our data */
8551 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8552 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
8553 ssh->ospeed, ssh->ispeed);
8554 ssh->got_pty = TRUE;
8556 c_write_str(ssh, "Server refused to allocate pty\r\n");
8557 ssh->editing = ssh->echoing = 1;
8564 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
8567 struct ssh2_setup_env_state {
8569 int num_env, env_left, env_ok;
8572 struct Packet *pktout;
8573 crStateP(ssh2_setup_env_state, ctx);
8578 * Send environment variables.
8580 * Simplest thing here is to send all the requests at once, and
8581 * then wait for a whole bunch of successes or failures.
8587 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
8589 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
8590 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
8591 ssh2_pkt_addstring(pktout, key);
8592 ssh2_pkt_addstring(pktout, val);
8593 ssh2_pkt_send(ssh, pktout);
8598 logeventf(ssh, "Sent %d environment variables", s->num_env);
8603 s->env_left = s->num_env;
8605 while (s->env_left > 0) {
8606 /* Wait to be called back with either a response packet,
8607 * or NULL meaning clean up and free our data */
8609 if (!pktin) goto out;
8610 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
8615 if (s->env_ok == s->num_env) {
8616 logevent("All environment variables successfully set");
8617 } else if (s->env_ok == 0) {
8618 logevent("All environment variables refused");
8619 c_write_str(ssh, "Server refused to set environment variables\r\n");
8621 logeventf(ssh, "%d environment variables refused",
8622 s->num_env - s->env_ok);
8623 c_write_str(ssh, "Server refused to set all environment variables\r\n");
8631 * Handle the SSH-2 userauth and connection layers.
8633 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
8635 do_ssh2_authconn(ssh, NULL, 0, pktin);
8638 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
8642 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
8645 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
8646 struct Packet *pktin)
8648 struct do_ssh2_authconn_state {
8652 AUTH_TYPE_PUBLICKEY,
8653 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
8654 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
8656 AUTH_TYPE_GSSAPI, /* always QUIET */
8657 AUTH_TYPE_KEYBOARD_INTERACTIVE,
8658 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
8660 int done_service_req;
8661 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
8662 int tried_pubkey_config, done_agent;
8667 int kbd_inter_refused;
8668 int we_are_in, userauth_success;
8669 prompts_t *cur_prompt;
8674 void *publickey_blob;
8675 int publickey_bloblen;
8676 int publickey_encrypted;
8677 char *publickey_algorithm;
8678 char *publickey_comment;
8679 unsigned char agent_request[5], *agent_response, *agentp;
8680 int agent_responselen;
8681 unsigned char *pkblob_in_agent;
8683 char *pkblob, *alg, *commentp;
8684 int pklen, alglen, commentlen;
8685 int siglen, retlen, len;
8686 char *q, *agentreq, *ret;
8688 struct Packet *pktout;
8691 struct ssh_gss_library *gsslib;
8692 Ssh_gss_ctx gss_ctx;
8693 Ssh_gss_buf gss_buf;
8694 Ssh_gss_buf gss_rcvtok, gss_sndtok;
8695 Ssh_gss_name gss_srv_name;
8696 Ssh_gss_stat gss_stat;
8699 crState(do_ssh2_authconn_state);
8703 /* Register as a handler for all the messages this coroutine handles. */
8704 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
8705 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
8706 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
8707 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
8708 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
8709 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
8710 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
8711 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
8712 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
8713 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
8714 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
8715 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
8716 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
8717 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
8718 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
8719 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
8720 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
8721 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
8722 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
8723 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
8725 s->done_service_req = FALSE;
8726 s->we_are_in = s->userauth_success = FALSE;
8727 s->agent_response = NULL;
8729 s->tried_gssapi = FALSE;
8732 if (!ssh->bare_connection) {
8733 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
8735 * Request userauth protocol, and await a response to it.
8737 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8738 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
8739 ssh2_pkt_send(ssh, s->pktout);
8740 crWaitUntilV(pktin);
8741 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
8742 s->done_service_req = TRUE;
8744 if (!s->done_service_req) {
8746 * Request connection protocol directly, without authentication.
8748 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8749 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8750 ssh2_pkt_send(ssh, s->pktout);
8751 crWaitUntilV(pktin);
8752 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
8753 s->we_are_in = TRUE; /* no auth required */
8755 bombout(("Server refused service request"));
8760 s->we_are_in = TRUE;
8763 /* Arrange to be able to deal with any BANNERs that come in.
8764 * (We do this now as packets may come in during the next bit.) */
8765 bufchain_init(&ssh->banner);
8766 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
8767 ssh2_msg_userauth_banner;
8770 * Misc one-time setup for authentication.
8772 s->publickey_blob = NULL;
8773 if (!s->we_are_in) {
8776 * Load the public half of any configured public key file
8779 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
8780 if (!filename_is_null(s->keyfile)) {
8782 logeventf(ssh, "Reading private key file \"%.150s\"",
8783 filename_to_str(s->keyfile));
8784 keytype = key_type(s->keyfile);
8785 if (keytype == SSH_KEYTYPE_SSH2) {
8788 ssh2_userkey_loadpub(s->keyfile,
8789 &s->publickey_algorithm,
8790 &s->publickey_bloblen,
8791 &s->publickey_comment, &error);
8792 if (s->publickey_blob) {
8793 s->publickey_encrypted =
8794 ssh2_userkey_encrypted(s->keyfile, NULL);
8797 logeventf(ssh, "Unable to load private key (%s)",
8799 msgbuf = dupprintf("Unable to load private key file "
8800 "\"%.150s\" (%s)\r\n",
8801 filename_to_str(s->keyfile),
8803 c_write_str(ssh, msgbuf);
8808 logeventf(ssh, "Unable to use this key file (%s)",
8809 key_type_to_str(keytype));
8810 msgbuf = dupprintf("Unable to use key file \"%.150s\""
8812 filename_to_str(s->keyfile),
8813 key_type_to_str(keytype));
8814 c_write_str(ssh, msgbuf);
8816 s->publickey_blob = NULL;
8821 * Find out about any keys Pageant has (but if there's a
8822 * public key configured, filter out all others).
8825 s->agent_response = NULL;
8826 s->pkblob_in_agent = NULL;
8827 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
8831 logevent("Pageant is running. Requesting keys.");
8833 /* Request the keys held by the agent. */
8834 PUT_32BIT(s->agent_request, 1);
8835 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
8836 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
8837 ssh_agent_callback, ssh)) {
8841 bombout(("Unexpected data from server while"
8842 " waiting for agent response"));
8845 } while (pktin || inlen > 0);
8846 r = ssh->agent_response;
8847 s->agent_responselen = ssh->agent_response_len;
8849 s->agent_response = (unsigned char *) r;
8850 if (s->agent_response && s->agent_responselen >= 5 &&
8851 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
8854 p = s->agent_response + 5;
8855 s->nkeys = toint(GET_32BIT(p));
8858 * Vet the Pageant response to ensure that the key
8859 * count and blob lengths make sense.
8862 logeventf(ssh, "Pageant response contained a negative"
8863 " key count %d", s->nkeys);
8865 goto done_agent_query;
8867 unsigned char *q = p + 4;
8868 int lenleft = s->agent_responselen - 5 - 4;
8870 for (keyi = 0; keyi < s->nkeys; keyi++) {
8871 int bloblen, commentlen;
8873 logeventf(ssh, "Pageant response was truncated");
8875 goto done_agent_query;
8877 bloblen = toint(GET_32BIT(q));
8878 if (bloblen < 0 || bloblen > lenleft) {
8879 logeventf(ssh, "Pageant response was truncated");
8881 goto done_agent_query;
8883 lenleft -= 4 + bloblen;
8885 commentlen = toint(GET_32BIT(q));
8886 if (commentlen < 0 || commentlen > lenleft) {
8887 logeventf(ssh, "Pageant response was truncated");
8889 goto done_agent_query;
8891 lenleft -= 4 + commentlen;
8892 q += 4 + commentlen;
8897 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
8898 if (s->publickey_blob) {
8899 /* See if configured key is in agent. */
8900 for (keyi = 0; keyi < s->nkeys; keyi++) {
8901 s->pklen = toint(GET_32BIT(p));
8902 if (s->pklen == s->publickey_bloblen &&
8903 !memcmp(p+4, s->publickey_blob,
8904 s->publickey_bloblen)) {
8905 logeventf(ssh, "Pageant key #%d matches "
8906 "configured key file", keyi);
8908 s->pkblob_in_agent = p;
8912 p += toint(GET_32BIT(p)) + 4; /* comment */
8914 if (!s->pkblob_in_agent) {
8915 logevent("Configured key file not in Pageant");
8920 logevent("Failed to get reply from Pageant");
8928 * We repeat this whole loop, including the username prompt,
8929 * until we manage a successful authentication. If the user
8930 * types the wrong _password_, they can be sent back to the
8931 * beginning to try another username, if this is configured on.
8932 * (If they specify a username in the config, they are never
8933 * asked, even if they do give a wrong password.)
8935 * I think this best serves the needs of
8937 * - the people who have no configuration, no keys, and just
8938 * want to try repeated (username,password) pairs until they
8939 * type both correctly
8941 * - people who have keys and configuration but occasionally
8942 * need to fall back to passwords
8944 * - people with a key held in Pageant, who might not have
8945 * logged in to a particular machine before; so they want to
8946 * type a username, and then _either_ their key will be
8947 * accepted, _or_ they will type a password. If they mistype
8948 * the username they will want to be able to get back and
8951 s->got_username = FALSE;
8952 while (!s->we_are_in) {
8956 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
8958 * We got a username last time round this loop, and
8959 * with change_username turned off we don't try to get
8962 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
8963 int ret; /* need not be kept over crReturn */
8964 s->cur_prompt = new_prompts(ssh->frontend);
8965 s->cur_prompt->to_server = TRUE;
8966 s->cur_prompt->name = dupstr("SSH login name");
8967 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
8968 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8971 crWaitUntilV(!pktin);
8972 ret = get_userpass_input(s->cur_prompt, in, inlen);
8977 * get_userpass_input() failed to get a username.
8980 free_prompts(s->cur_prompt);
8981 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
8984 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
8985 free_prompts(s->cur_prompt);
8988 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
8989 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
8990 c_write_str(ssh, stuff);
8994 s->got_username = TRUE;
8997 * Send an authentication request using method "none": (a)
8998 * just in case it succeeds, and (b) so that we know what
8999 * authentication methods we can usefully try next.
9001 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9003 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9004 ssh2_pkt_addstring(s->pktout, ssh->username);
9005 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
9006 ssh2_pkt_addstring(s->pktout, "none"); /* method */
9007 ssh2_pkt_send(ssh, s->pktout);
9008 s->type = AUTH_TYPE_NONE;
9010 s->we_are_in = FALSE;
9012 s->tried_pubkey_config = FALSE;
9013 s->kbd_inter_refused = FALSE;
9015 /* Reset agent request state. */
9016 s->done_agent = FALSE;
9017 if (s->agent_response) {
9018 if (s->pkblob_in_agent) {
9019 s->agentp = s->pkblob_in_agent;
9021 s->agentp = s->agent_response + 5 + 4;
9027 char *methods = NULL;
9031 * Wait for the result of the last authentication request.
9034 crWaitUntilV(pktin);
9036 * Now is a convenient point to spew any banner material
9037 * that we've accumulated. (This should ensure that when
9038 * we exit the auth loop, we haven't any left to deal
9042 int size = bufchain_size(&ssh->banner);
9044 * Don't show the banner if we're operating in
9045 * non-verbose non-interactive mode. (It's probably
9046 * a script, which means nobody will read the
9047 * banner _anyway_, and moreover the printing of
9048 * the banner will screw up processing on the
9049 * output of (say) plink.)
9051 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
9052 char *banner = snewn(size, char);
9053 bufchain_fetch(&ssh->banner, banner, size);
9054 c_write_untrusted(ssh, banner, size);
9057 bufchain_clear(&ssh->banner);
9059 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
9060 logevent("Access granted");
9061 s->we_are_in = s->userauth_success = TRUE;
9065 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
9066 bombout(("Strange packet received during authentication: "
9067 "type %d", pktin->type));
9074 * OK, we're now sitting on a USERAUTH_FAILURE message, so
9075 * we can look at the string in it and know what we can
9076 * helpfully try next.
9078 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
9079 ssh_pkt_getstring(pktin, &methods, &methlen);
9080 if (!ssh2_pkt_getbool(pktin)) {
9082 * We have received an unequivocal Access
9083 * Denied. This can translate to a variety of
9084 * messages, or no message at all.
9086 * For forms of authentication which are attempted
9087 * implicitly, by which I mean without printing
9088 * anything in the window indicating that we're
9089 * trying them, we should never print 'Access
9092 * If we do print a message saying that we're
9093 * attempting some kind of authentication, it's OK
9094 * to print a followup message saying it failed -
9095 * but the message may sometimes be more specific
9096 * than simply 'Access denied'.
9098 * Additionally, if we'd just tried password
9099 * authentication, we should break out of this
9100 * whole loop so as to go back to the username
9101 * prompt (iff we're configured to allow
9102 * username change attempts).
9104 if (s->type == AUTH_TYPE_NONE) {
9106 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
9107 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
9108 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
9109 c_write_str(ssh, "Server refused our key\r\n");
9110 logevent("Server refused our key");
9111 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
9112 /* This _shouldn't_ happen except by a
9113 * protocol bug causing client and server to
9114 * disagree on what is a correct signature. */
9115 c_write_str(ssh, "Server refused public-key signature"
9116 " despite accepting key!\r\n");
9117 logevent("Server refused public-key signature"
9118 " despite accepting key!");
9119 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
9120 /* quiet, so no c_write */
9121 logevent("Server refused keyboard-interactive authentication");
9122 } else if (s->type==AUTH_TYPE_GSSAPI) {
9123 /* always quiet, so no c_write */
9124 /* also, the code down in the GSSAPI block has
9125 * already logged this in the Event Log */
9126 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
9127 logevent("Keyboard-interactive authentication failed");
9128 c_write_str(ssh, "Access denied\r\n");
9130 assert(s->type == AUTH_TYPE_PASSWORD);
9131 logevent("Password authentication failed");
9132 c_write_str(ssh, "Access denied\r\n");
9134 if (conf_get_int(ssh->conf, CONF_change_username)) {
9135 /* XXX perhaps we should allow
9136 * keyboard-interactive to do this too? */
9137 s->we_are_in = FALSE;
9142 c_write_str(ssh, "Further authentication required\r\n");
9143 logevent("Further authentication required");
9147 in_commasep_string("publickey", methods, methlen);
9149 in_commasep_string("password", methods, methlen);
9150 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
9151 in_commasep_string("keyboard-interactive", methods, methlen);
9154 ssh->gsslibs = ssh_gss_setup(ssh->conf);
9155 s->can_gssapi = conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
9156 in_commasep_string("gssapi-with-mic", methods, methlen) &&
9157 ssh->gsslibs->nlibraries > 0;
9161 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9163 if (s->can_pubkey && !s->done_agent && s->nkeys) {
9166 * Attempt public-key authentication using a key from Pageant.
9169 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9171 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
9173 /* Unpack key from agent response */
9174 s->pklen = toint(GET_32BIT(s->agentp));
9176 s->pkblob = (char *)s->agentp;
9177 s->agentp += s->pklen;
9178 s->alglen = toint(GET_32BIT(s->pkblob));
9179 s->alg = s->pkblob + 4;
9180 s->commentlen = toint(GET_32BIT(s->agentp));
9182 s->commentp = (char *)s->agentp;
9183 s->agentp += s->commentlen;
9184 /* s->agentp now points at next key, if any */
9186 /* See if server will accept it */
9187 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9188 ssh2_pkt_addstring(s->pktout, ssh->username);
9189 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9190 /* service requested */
9191 ssh2_pkt_addstring(s->pktout, "publickey");
9193 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
9194 ssh2_pkt_addstring_start(s->pktout);
9195 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9196 ssh2_pkt_addstring_start(s->pktout);
9197 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9198 ssh2_pkt_send(ssh, s->pktout);
9199 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
9201 crWaitUntilV(pktin);
9202 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9204 /* Offer of key refused. */
9211 if (flags & FLAG_VERBOSE) {
9212 c_write_str(ssh, "Authenticating with "
9214 c_write(ssh, s->commentp, s->commentlen);
9215 c_write_str(ssh, "\" from agent\r\n");
9219 * Server is willing to accept the key.
9220 * Construct a SIGN_REQUEST.
9222 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9223 ssh2_pkt_addstring(s->pktout, ssh->username);
9224 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9225 /* service requested */
9226 ssh2_pkt_addstring(s->pktout, "publickey");
9228 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
9229 ssh2_pkt_addstring_start(s->pktout);
9230 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9231 ssh2_pkt_addstring_start(s->pktout);
9232 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9234 /* Ask agent for signature. */
9235 s->siglen = s->pktout->length - 5 + 4 +
9236 ssh->v2_session_id_len;
9237 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9239 s->len = 1; /* message type */
9240 s->len += 4 + s->pklen; /* key blob */
9241 s->len += 4 + s->siglen; /* data to sign */
9242 s->len += 4; /* flags */
9243 s->agentreq = snewn(4 + s->len, char);
9244 PUT_32BIT(s->agentreq, s->len);
9245 s->q = s->agentreq + 4;
9246 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
9247 PUT_32BIT(s->q, s->pklen);
9249 memcpy(s->q, s->pkblob, s->pklen);
9251 PUT_32BIT(s->q, s->siglen);
9253 /* Now the data to be signed... */
9254 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9255 PUT_32BIT(s->q, ssh->v2_session_id_len);
9258 memcpy(s->q, ssh->v2_session_id,
9259 ssh->v2_session_id_len);
9260 s->q += ssh->v2_session_id_len;
9261 memcpy(s->q, s->pktout->data + 5,
9262 s->pktout->length - 5);
9263 s->q += s->pktout->length - 5;
9264 /* And finally the (zero) flags word. */
9266 if (!agent_query(s->agentreq, s->len + 4,
9268 ssh_agent_callback, ssh)) {
9272 bombout(("Unexpected data from server"
9273 " while waiting for agent"
9277 } while (pktin || inlen > 0);
9278 vret = ssh->agent_response;
9279 s->retlen = ssh->agent_response_len;
9284 if (s->retlen >= 9 &&
9285 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
9286 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
9287 logevent("Sending Pageant's response");
9288 ssh2_add_sigblob(ssh, s->pktout,
9289 s->pkblob, s->pklen,
9291 GET_32BIT(s->ret + 5));
9292 ssh2_pkt_send(ssh, s->pktout);
9293 s->type = AUTH_TYPE_PUBLICKEY;
9295 /* FIXME: less drastic response */
9296 bombout(("Pageant failed to answer challenge"));
9302 /* Do we have any keys left to try? */
9303 if (s->pkblob_in_agent) {
9304 s->done_agent = TRUE;
9305 s->tried_pubkey_config = TRUE;
9308 if (s->keyi >= s->nkeys)
9309 s->done_agent = TRUE;
9312 } else if (s->can_pubkey && s->publickey_blob &&
9313 !s->tried_pubkey_config) {
9315 struct ssh2_userkey *key; /* not live over crReturn */
9316 char *passphrase; /* not live over crReturn */
9318 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9320 s->tried_pubkey_config = TRUE;
9323 * Try the public key supplied in the configuration.
9325 * First, offer the public blob to see if the server is
9326 * willing to accept it.
9328 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9329 ssh2_pkt_addstring(s->pktout, ssh->username);
9330 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9331 /* service requested */
9332 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
9333 ssh2_pkt_addbool(s->pktout, FALSE);
9334 /* no signature included */
9335 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
9336 ssh2_pkt_addstring_start(s->pktout);
9337 ssh2_pkt_addstring_data(s->pktout,
9338 (char *)s->publickey_blob,
9339 s->publickey_bloblen);
9340 ssh2_pkt_send(ssh, s->pktout);
9341 logevent("Offered public key");
9343 crWaitUntilV(pktin);
9344 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9345 /* Key refused. Give up. */
9346 s->gotit = TRUE; /* reconsider message next loop */
9347 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
9348 continue; /* process this new message */
9350 logevent("Offer of public key accepted");
9353 * Actually attempt a serious authentication using
9356 if (flags & FLAG_VERBOSE) {
9357 c_write_str(ssh, "Authenticating with public key \"");
9358 c_write_str(ssh, s->publickey_comment);
9359 c_write_str(ssh, "\"\r\n");
9363 const char *error; /* not live over crReturn */
9364 if (s->publickey_encrypted) {
9366 * Get a passphrase from the user.
9368 int ret; /* need not be kept over crReturn */
9369 s->cur_prompt = new_prompts(ssh->frontend);
9370 s->cur_prompt->to_server = FALSE;
9371 s->cur_prompt->name = dupstr("SSH key passphrase");
9372 add_prompt(s->cur_prompt,
9373 dupprintf("Passphrase for key \"%.100s\": ",
9374 s->publickey_comment),
9376 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9379 crWaitUntilV(!pktin);
9380 ret = get_userpass_input(s->cur_prompt,
9385 /* Failed to get a passphrase. Terminate. */
9386 free_prompts(s->cur_prompt);
9387 ssh_disconnect(ssh, NULL,
9388 "Unable to authenticate",
9389 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9394 dupstr(s->cur_prompt->prompts[0]->result);
9395 free_prompts(s->cur_prompt);
9397 passphrase = NULL; /* no passphrase needed */
9401 * Try decrypting the key.
9403 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9404 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
9406 /* burn the evidence */
9407 smemclr(passphrase, strlen(passphrase));
9410 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
9412 (key == SSH2_WRONG_PASSPHRASE)) {
9413 c_write_str(ssh, "Wrong passphrase\r\n");
9415 /* and loop again */
9417 c_write_str(ssh, "Unable to load private key (");
9418 c_write_str(ssh, error);
9419 c_write_str(ssh, ")\r\n");
9421 break; /* try something else */
9427 unsigned char *pkblob, *sigblob, *sigdata;
9428 int pkblob_len, sigblob_len, sigdata_len;
9432 * We have loaded the private key and the server
9433 * has announced that it's willing to accept it.
9434 * Hallelujah. Generate a signature and send it.
9436 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9437 ssh2_pkt_addstring(s->pktout, ssh->username);
9438 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9439 /* service requested */
9440 ssh2_pkt_addstring(s->pktout, "publickey");
9442 ssh2_pkt_addbool(s->pktout, TRUE);
9443 /* signature follows */
9444 ssh2_pkt_addstring(s->pktout, key->alg->name);
9445 pkblob = key->alg->public_blob(key->data,
9447 ssh2_pkt_addstring_start(s->pktout);
9448 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
9452 * The data to be signed is:
9456 * followed by everything so far placed in the
9459 sigdata_len = s->pktout->length - 5 + 4 +
9460 ssh->v2_session_id_len;
9461 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9463 sigdata = snewn(sigdata_len, unsigned char);
9465 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9466 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
9469 memcpy(sigdata+p, ssh->v2_session_id,
9470 ssh->v2_session_id_len);
9471 p += ssh->v2_session_id_len;
9472 memcpy(sigdata+p, s->pktout->data + 5,
9473 s->pktout->length - 5);
9474 p += s->pktout->length - 5;
9475 assert(p == sigdata_len);
9476 sigblob = key->alg->sign(key->data, (char *)sigdata,
9477 sigdata_len, &sigblob_len);
9478 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
9479 sigblob, sigblob_len);
9484 ssh2_pkt_send(ssh, s->pktout);
9485 logevent("Sent public key signature");
9486 s->type = AUTH_TYPE_PUBLICKEY;
9487 key->alg->freekey(key->data);
9491 } else if (s->can_gssapi && !s->tried_gssapi) {
9493 /* GSSAPI Authentication */
9498 s->type = AUTH_TYPE_GSSAPI;
9499 s->tried_gssapi = TRUE;
9501 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
9504 * Pick the highest GSS library on the preference
9510 for (i = 0; i < ngsslibs; i++) {
9511 int want_id = conf_get_int_int(ssh->conf,
9512 CONF_ssh_gsslist, i);
9513 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
9514 if (ssh->gsslibs->libraries[j].id == want_id) {
9515 s->gsslib = &ssh->gsslibs->libraries[j];
9516 goto got_gsslib; /* double break */
9521 * We always expect to have found something in
9522 * the above loop: we only came here if there
9523 * was at least one viable GSS library, and the
9524 * preference list should always mention
9525 * everything and only change the order.
9530 if (s->gsslib->gsslogmsg)
9531 logevent(s->gsslib->gsslogmsg);
9533 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
9534 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9535 ssh2_pkt_addstring(s->pktout, ssh->username);
9536 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9537 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
9538 logevent("Attempting GSSAPI authentication");
9540 /* add mechanism info */
9541 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
9543 /* number of GSSAPI mechanisms */
9544 ssh2_pkt_adduint32(s->pktout,1);
9546 /* length of OID + 2 */
9547 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
9548 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
9551 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
9553 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
9555 ssh2_pkt_send(ssh, s->pktout);
9556 crWaitUntilV(pktin);
9557 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
9558 logevent("GSSAPI authentication request refused");
9562 /* check returned packet ... */
9564 ssh_pkt_getstring(pktin, &data, &len);
9565 s->gss_rcvtok.value = data;
9566 s->gss_rcvtok.length = len;
9567 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
9568 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
9569 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
9570 memcmp((char *)s->gss_rcvtok.value + 2,
9571 s->gss_buf.value,s->gss_buf.length) ) {
9572 logevent("GSSAPI authentication - wrong response from server");
9576 /* now start running */
9577 s->gss_stat = s->gsslib->import_name(s->gsslib,
9580 if (s->gss_stat != SSH_GSS_OK) {
9581 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
9582 logevent("GSSAPI import name failed - Bad service name");
9584 logevent("GSSAPI import name failed");
9588 /* fetch TGT into GSS engine */
9589 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
9591 if (s->gss_stat != SSH_GSS_OK) {
9592 logevent("GSSAPI authentication failed to get credentials");
9593 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9597 /* initial tokens are empty */
9598 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
9599 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
9601 /* now enter the loop */
9603 s->gss_stat = s->gsslib->init_sec_context
9607 conf_get_int(ssh->conf, CONF_gssapifwd),
9611 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
9612 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
9613 logevent("GSSAPI authentication initialisation failed");
9615 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
9616 &s->gss_buf) == SSH_GSS_OK) {
9617 logevent(s->gss_buf.value);
9618 sfree(s->gss_buf.value);
9623 logevent("GSSAPI authentication initialised");
9625 /* Client and server now exchange tokens until GSSAPI
9626 * no longer says CONTINUE_NEEDED */
9628 if (s->gss_sndtok.length != 0) {
9629 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
9630 ssh_pkt_addstring_start(s->pktout);
9631 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
9632 ssh2_pkt_send(ssh, s->pktout);
9633 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
9636 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
9637 crWaitUntilV(pktin);
9638 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
9639 logevent("GSSAPI authentication - bad server response");
9640 s->gss_stat = SSH_GSS_FAILURE;
9643 ssh_pkt_getstring(pktin, &data, &len);
9644 s->gss_rcvtok.value = data;
9645 s->gss_rcvtok.length = len;
9647 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
9649 if (s->gss_stat != SSH_GSS_OK) {
9650 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9651 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9654 logevent("GSSAPI authentication loop finished OK");
9656 /* Now send the MIC */
9658 s->pktout = ssh2_pkt_init(0);
9659 micoffset = s->pktout->length;
9660 ssh_pkt_addstring_start(s->pktout);
9661 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
9662 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
9663 ssh_pkt_addstring(s->pktout, ssh->username);
9664 ssh_pkt_addstring(s->pktout, "ssh-connection");
9665 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
9667 s->gss_buf.value = (char *)s->pktout->data + micoffset;
9668 s->gss_buf.length = s->pktout->length - micoffset;
9670 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
9671 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
9672 ssh_pkt_addstring_start(s->pktout);
9673 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
9674 ssh2_pkt_send(ssh, s->pktout);
9675 s->gsslib->free_mic(s->gsslib, &mic);
9679 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9680 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9683 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
9686 * Keyboard-interactive authentication.
9689 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
9691 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
9693 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9694 ssh2_pkt_addstring(s->pktout, ssh->username);
9695 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9696 /* service requested */
9697 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
9699 ssh2_pkt_addstring(s->pktout, ""); /* lang */
9700 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
9701 ssh2_pkt_send(ssh, s->pktout);
9703 logevent("Attempting keyboard-interactive authentication");
9705 crWaitUntilV(pktin);
9706 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
9707 /* Server is not willing to do keyboard-interactive
9708 * at all (or, bizarrely but legally, accepts the
9709 * user without actually issuing any prompts).
9710 * Give up on it entirely. */
9712 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
9713 s->kbd_inter_refused = TRUE; /* don't try it again */
9718 * Loop while the server continues to send INFO_REQUESTs.
9720 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
9722 char *name, *inst, *lang;
9723 int name_len, inst_len, lang_len;
9727 * We've got a fresh USERAUTH_INFO_REQUEST.
9728 * Get the preamble and start building a prompt.
9730 ssh_pkt_getstring(pktin, &name, &name_len);
9731 ssh_pkt_getstring(pktin, &inst, &inst_len);
9732 ssh_pkt_getstring(pktin, &lang, &lang_len);
9733 s->cur_prompt = new_prompts(ssh->frontend);
9734 s->cur_prompt->to_server = TRUE;
9737 * Get any prompt(s) from the packet.
9739 s->num_prompts = ssh_pkt_getuint32(pktin);
9740 for (i = 0; i < s->num_prompts; i++) {
9744 static char noprompt[] =
9745 "<server failed to send prompt>: ";
9747 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9748 echo = ssh2_pkt_getbool(pktin);
9751 prompt_len = lenof(noprompt)-1;
9753 add_prompt(s->cur_prompt,
9754 dupprintf("%.*s", prompt_len, prompt),
9759 /* FIXME: better prefix to distinguish from
9761 s->cur_prompt->name =
9762 dupprintf("SSH server: %.*s", name_len, name);
9763 s->cur_prompt->name_reqd = TRUE;
9765 s->cur_prompt->name =
9766 dupstr("SSH server authentication");
9767 s->cur_prompt->name_reqd = FALSE;
9769 /* We add a prefix to try to make it clear that a prompt
9770 * has come from the server.
9771 * FIXME: ugly to print "Using..." in prompt _every_
9772 * time round. Can this be done more subtly? */
9773 /* Special case: for reasons best known to themselves,
9774 * some servers send k-i requests with no prompts and
9775 * nothing to display. Keep quiet in this case. */
9776 if (s->num_prompts || name_len || inst_len) {
9777 s->cur_prompt->instruction =
9778 dupprintf("Using keyboard-interactive authentication.%s%.*s",
9779 inst_len ? "\n" : "", inst_len, inst);
9780 s->cur_prompt->instr_reqd = TRUE;
9782 s->cur_prompt->instr_reqd = FALSE;
9786 * Display any instructions, and get the user's
9790 int ret; /* not live over crReturn */
9791 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9794 crWaitUntilV(!pktin);
9795 ret = get_userpass_input(s->cur_prompt, in, inlen);
9800 * Failed to get responses. Terminate.
9802 free_prompts(s->cur_prompt);
9803 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9804 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9811 * Send the response(s) to the server.
9813 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
9814 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
9815 for (i=0; i < s->num_prompts; i++) {
9816 ssh2_pkt_addstring(s->pktout,
9817 s->cur_prompt->prompts[i]->result);
9819 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9822 * Free the prompts structure from this iteration.
9823 * If there's another, a new one will be allocated
9824 * when we return to the top of this while loop.
9826 free_prompts(s->cur_prompt);
9829 * Get the next packet in case it's another
9832 crWaitUntilV(pktin);
9837 * We should have SUCCESS or FAILURE now.
9841 } else if (s->can_passwd) {
9844 * Plain old password authentication.
9846 int ret; /* not live over crReturn */
9847 int changereq_first_time; /* not live over crReturn */
9849 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
9851 s->cur_prompt = new_prompts(ssh->frontend);
9852 s->cur_prompt->to_server = TRUE;
9853 s->cur_prompt->name = dupstr("SSH password");
9854 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
9859 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9862 crWaitUntilV(!pktin);
9863 ret = get_userpass_input(s->cur_prompt, in, inlen);
9868 * Failed to get responses. Terminate.
9870 free_prompts(s->cur_prompt);
9871 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9872 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9877 * Squirrel away the password. (We may need it later if
9878 * asked to change it.)
9880 s->password = dupstr(s->cur_prompt->prompts[0]->result);
9881 free_prompts(s->cur_prompt);
9884 * Send the password packet.
9886 * We pad out the password packet to 256 bytes to make
9887 * it harder for an attacker to find the length of the
9890 * Anyone using a password longer than 256 bytes
9891 * probably doesn't have much to worry about from
9892 * people who find out how long their password is!
9894 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9895 ssh2_pkt_addstring(s->pktout, ssh->username);
9896 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9897 /* service requested */
9898 ssh2_pkt_addstring(s->pktout, "password");
9899 ssh2_pkt_addbool(s->pktout, FALSE);
9900 ssh2_pkt_addstring(s->pktout, s->password);
9901 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9902 logevent("Sent password");
9903 s->type = AUTH_TYPE_PASSWORD;
9906 * Wait for next packet, in case it's a password change
9909 crWaitUntilV(pktin);
9910 changereq_first_time = TRUE;
9912 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
9915 * We're being asked for a new password
9916 * (perhaps not for the first time).
9917 * Loop until the server accepts it.
9920 int got_new = FALSE; /* not live over crReturn */
9921 char *prompt; /* not live over crReturn */
9922 int prompt_len; /* not live over crReturn */
9926 if (changereq_first_time)
9927 msg = "Server requested password change";
9929 msg = "Server rejected new password";
9931 c_write_str(ssh, msg);
9932 c_write_str(ssh, "\r\n");
9935 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9937 s->cur_prompt = new_prompts(ssh->frontend);
9938 s->cur_prompt->to_server = TRUE;
9939 s->cur_prompt->name = dupstr("New SSH password");
9940 s->cur_prompt->instruction =
9941 dupprintf("%.*s", prompt_len, prompt);
9942 s->cur_prompt->instr_reqd = TRUE;
9944 * There's no explicit requirement in the protocol
9945 * for the "old" passwords in the original and
9946 * password-change messages to be the same, and
9947 * apparently some Cisco kit supports password change
9948 * by the user entering a blank password originally
9949 * and the real password subsequently, so,
9950 * reluctantly, we prompt for the old password again.
9952 * (On the other hand, some servers don't even bother
9953 * to check this field.)
9955 add_prompt(s->cur_prompt,
9956 dupstr("Current password (blank for previously entered password): "),
9958 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
9960 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
9964 * Loop until the user manages to enter the same
9969 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9972 crWaitUntilV(!pktin);
9973 ret = get_userpass_input(s->cur_prompt, in, inlen);
9978 * Failed to get responses. Terminate.
9980 /* burn the evidence */
9981 free_prompts(s->cur_prompt);
9982 smemclr(s->password, strlen(s->password));
9984 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9985 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9991 * If the user specified a new original password
9992 * (IYSWIM), overwrite any previously specified
9994 * (A side effect is that the user doesn't have to
9995 * re-enter it if they louse up the new password.)
9997 if (s->cur_prompt->prompts[0]->result[0]) {
9998 smemclr(s->password, strlen(s->password));
9999 /* burn the evidence */
10000 sfree(s->password);
10002 dupstr(s->cur_prompt->prompts[0]->result);
10006 * Check the two new passwords match.
10008 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
10009 s->cur_prompt->prompts[2]->result)
10012 /* They don't. Silly user. */
10013 c_write_str(ssh, "Passwords do not match\r\n");
10018 * Send the new password (along with the old one).
10019 * (see above for padding rationale)
10021 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10022 ssh2_pkt_addstring(s->pktout, ssh->username);
10023 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10024 /* service requested */
10025 ssh2_pkt_addstring(s->pktout, "password");
10026 ssh2_pkt_addbool(s->pktout, TRUE);
10027 ssh2_pkt_addstring(s->pktout, s->password);
10028 ssh2_pkt_addstring(s->pktout,
10029 s->cur_prompt->prompts[1]->result);
10030 free_prompts(s->cur_prompt);
10031 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10032 logevent("Sent new password");
10035 * Now see what the server has to say about it.
10036 * (If it's CHANGEREQ again, it's not happy with the
10039 crWaitUntilV(pktin);
10040 changereq_first_time = FALSE;
10045 * We need to reexamine the current pktin at the top
10046 * of the loop. Either:
10047 * - we weren't asked to change password at all, in
10048 * which case it's a SUCCESS or FAILURE with the
10050 * - we sent a new password, and the server was
10051 * either OK with it (SUCCESS or FAILURE w/partial
10052 * success) or unhappy with the _old_ password
10053 * (FAILURE w/o partial success)
10054 * In any of these cases, we go back to the top of
10055 * the loop and start again.
10060 * We don't need the old password any more, in any
10061 * case. Burn the evidence.
10063 smemclr(s->password, strlen(s->password));
10064 sfree(s->password);
10067 char *str = dupprintf("No supported authentication methods available"
10068 " (server sent: %.*s)",
10071 ssh_disconnect(ssh, str,
10072 "No supported authentication methods available",
10073 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
10083 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
10085 /* Clear up various bits and pieces from authentication. */
10086 if (s->publickey_blob) {
10087 sfree(s->publickey_blob);
10088 sfree(s->publickey_comment);
10090 if (s->agent_response)
10091 sfree(s->agent_response);
10093 if (s->userauth_success && !ssh->bare_connection) {
10095 * We've just received USERAUTH_SUCCESS, and we haven't sent any
10096 * packets since. Signal the transport layer to consider enacting
10097 * delayed compression.
10099 * (Relying on we_are_in is not sufficient, as
10100 * draft-miller-secsh-compression-delayed is quite clear that it
10101 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
10102 * become set for other reasons.)
10104 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
10107 ssh->channels = newtree234(ssh_channelcmp);
10110 * Set up handlers for some connection protocol messages, so we
10111 * don't have to handle them repeatedly in this coroutine.
10113 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
10114 ssh2_msg_channel_window_adjust;
10115 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
10116 ssh2_msg_global_request;
10119 * Create the main session channel.
10121 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
10122 ssh->mainchan = NULL;
10124 ssh->mainchan = snew(struct ssh_channel);
10125 ssh->mainchan->ssh = ssh;
10126 ssh2_channel_init(ssh->mainchan);
10128 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
10130 * Just start a direct-tcpip channel and use it as the main
10133 ssh_send_port_open(ssh->mainchan,
10134 conf_get_str(ssh->conf, CONF_ssh_nc_host),
10135 conf_get_int(ssh->conf, CONF_ssh_nc_port),
10137 ssh->ncmode = TRUE;
10139 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
10140 logevent("Opening session as main channel");
10141 ssh2_pkt_send(ssh, s->pktout);
10142 ssh->ncmode = FALSE;
10144 crWaitUntilV(pktin);
10145 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
10146 bombout(("Server refused to open channel"));
10148 /* FIXME: error data comes back in FAILURE packet */
10150 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
10151 bombout(("Server's channel confirmation cited wrong channel"));
10154 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
10155 ssh->mainchan->halfopen = FALSE;
10156 ssh->mainchan->type = CHAN_MAINSESSION;
10157 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
10158 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
10159 add234(ssh->channels, ssh->mainchan);
10160 update_specials_menu(ssh->frontend);
10161 logevent("Opened main channel");
10165 * Now we have a channel, make dispatch table entries for
10166 * general channel-based messages.
10168 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
10169 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
10170 ssh2_msg_channel_data;
10171 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
10172 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
10173 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
10174 ssh2_msg_channel_open_confirmation;
10175 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
10176 ssh2_msg_channel_open_failure;
10177 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
10178 ssh2_msg_channel_request;
10179 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
10180 ssh2_msg_channel_open;
10181 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
10182 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
10185 * Now the connection protocol is properly up and running, with
10186 * all those dispatch table entries, so it's safe to let
10187 * downstreams start trying to open extra channels through us.
10189 if (ssh->connshare)
10190 share_activate(ssh->connshare, ssh->v_s);
10192 if (ssh->mainchan && ssh_is_simple(ssh)) {
10194 * This message indicates to the server that we promise
10195 * not to try to run any other channel in parallel with
10196 * this one, so it's safe for it to advertise a very large
10197 * window and leave the flow control to TCP.
10199 s->pktout = ssh2_chanreq_init(ssh->mainchan,
10200 "simple@putty.projects.tartarus.org",
10202 ssh2_pkt_send(ssh, s->pktout);
10206 * Enable port forwardings.
10208 ssh_setup_portfwd(ssh, ssh->conf);
10210 if (ssh->mainchan && !ssh->ncmode) {
10212 * Send the CHANNEL_REQUESTS for the main session channel.
10213 * Each one is handled by its own little asynchronous
10217 /* Potentially enable X11 forwarding. */
10218 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
10220 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
10222 if (!ssh->x11disp) {
10223 /* FIXME: return an error message from x11_setup_display */
10224 logevent("X11 forwarding not enabled: unable to"
10225 " initialise X display");
10227 ssh->x11auth = x11_invent_fake_auth
10228 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
10229 ssh->x11auth->disp = ssh->x11disp;
10231 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
10235 /* Potentially enable agent forwarding. */
10236 if (ssh_agent_forwarding_permitted(ssh))
10237 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
10239 /* Now allocate a pty for the session. */
10240 if (!conf_get_int(ssh->conf, CONF_nopty))
10241 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
10243 /* Send environment variables. */
10244 ssh2_setup_env(ssh->mainchan, NULL, NULL);
10247 * Start a shell or a remote command. We may have to attempt
10248 * this twice if the config data has provided a second choice
10255 if (ssh->fallback_cmd) {
10256 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
10257 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
10259 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
10260 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
10264 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
10265 ssh2_response_authconn, NULL);
10266 ssh2_pkt_addstring(s->pktout, cmd);
10268 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
10269 ssh2_response_authconn, NULL);
10270 ssh2_pkt_addstring(s->pktout, cmd);
10272 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
10273 ssh2_response_authconn, NULL);
10275 ssh2_pkt_send(ssh, s->pktout);
10277 crWaitUntilV(pktin);
10279 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
10280 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
10281 bombout(("Unexpected response to shell/command request:"
10282 " packet type %d", pktin->type));
10286 * We failed to start the command. If this is the
10287 * fallback command, we really are finished; if it's
10288 * not, and if the fallback command exists, try falling
10289 * back to it before complaining.
10291 if (!ssh->fallback_cmd &&
10292 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
10293 logevent("Primary command failed; attempting fallback");
10294 ssh->fallback_cmd = TRUE;
10297 bombout(("Server refused to start a shell/command"));
10300 logevent("Started a shell/command");
10305 ssh->editing = ssh->echoing = TRUE;
10308 ssh->state = SSH_STATE_SESSION;
10309 if (ssh->size_needed)
10310 ssh_size(ssh, ssh->term_width, ssh->term_height);
10311 if (ssh->eof_needed)
10312 ssh_special(ssh, TS_EOF);
10318 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
10323 s->try_send = FALSE;
10327 * _All_ the connection-layer packets we expect to
10328 * receive are now handled by the dispatch table.
10329 * Anything that reaches here must be bogus.
10332 bombout(("Strange packet received: type %d", pktin->type));
10334 } else if (ssh->mainchan) {
10336 * We have spare data. Add it to the channel buffer.
10338 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
10339 s->try_send = TRUE;
10343 struct ssh_channel *c;
10345 * Try to send data on all channels if we can.
10347 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
10348 ssh2_try_send_and_unthrottle(ssh, c);
10356 * Handlers for SSH-2 messages that might arrive at any moment.
10358 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
10360 /* log reason code in disconnect message */
10362 int reason, msglen;
10364 reason = ssh_pkt_getuint32(pktin);
10365 ssh_pkt_getstring(pktin, &msg, &msglen);
10367 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
10368 buf = dupprintf("Received disconnect message (%s)",
10369 ssh2_disconnect_reasons[reason]);
10371 buf = dupprintf("Received disconnect message (unknown"
10372 " type %d)", reason);
10376 buf = dupprintf("Disconnection message text: %.*s",
10379 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
10381 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
10382 ssh2_disconnect_reasons[reason] : "unknown",
10387 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
10389 /* log the debug message */
10393 /* XXX maybe we should actually take notice of the return value */
10394 ssh2_pkt_getbool(pktin);
10395 ssh_pkt_getstring(pktin, &msg, &msglen);
10397 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
10400 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
10402 do_ssh2_transport(ssh, NULL, 0, pktin);
10406 * Called if we receive a packet that isn't allowed by the protocol.
10407 * This only applies to packets whose meaning PuTTY understands.
10408 * Entirely unknown packets are handled below.
10410 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
10412 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
10413 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
10415 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
10419 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
10421 struct Packet *pktout;
10422 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
10423 ssh2_pkt_adduint32(pktout, pktin->sequence);
10425 * UNIMPLEMENTED messages MUST appear in the same order as the
10426 * messages they respond to. Hence, never queue them.
10428 ssh2_pkt_send_noqueue(ssh, pktout);
10432 * Handle the top-level SSH-2 protocol.
10434 static void ssh2_protocol_setup(Ssh ssh)
10439 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10441 for (i = 0; i < 256; i++)
10442 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10445 * Initially, we only accept transport messages (and a few generic
10446 * ones). do_ssh2_authconn will add more when it starts.
10447 * Messages that are understood but not currently acceptable go to
10448 * ssh2_msg_unexpected.
10450 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10451 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
10452 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
10453 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
10454 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
10455 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
10456 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
10457 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
10458 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
10459 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
10460 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
10461 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
10462 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
10463 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
10464 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
10465 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
10466 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
10467 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
10468 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
10469 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10470 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10471 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10472 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10473 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10474 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10475 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10476 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10477 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10478 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10479 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10480 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10481 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10482 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10485 * These messages have a special handler from the start.
10487 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10488 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
10489 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10492 static void ssh2_bare_connection_protocol_setup(Ssh ssh)
10497 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10499 for (i = 0; i < 256; i++)
10500 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10503 * Initially, we set all ssh-connection messages to 'unexpected';
10504 * do_ssh2_authconn will fill things in properly. We also handle a
10505 * couple of messages from the transport protocol which aren't
10506 * related to key exchange (UNIMPLEMENTED, IGNORE, DEBUG,
10509 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10510 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10511 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10512 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10513 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10514 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10515 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10516 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10517 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10518 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10519 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10520 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10521 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10522 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10524 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10527 * These messages have a special handler from the start.
10529 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10530 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore;
10531 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10534 static void ssh2_timer(void *ctx, unsigned long now)
10536 Ssh ssh = (Ssh)ctx;
10538 if (ssh->state == SSH_STATE_CLOSED)
10541 if (!ssh->kex_in_progress && !ssh->bare_connection &&
10542 conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
10543 now == ssh->next_rekey) {
10544 do_ssh2_transport(ssh, "timeout", -1, NULL);
10548 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
10549 struct Packet *pktin)
10551 unsigned char *in = (unsigned char *)vin;
10552 if (ssh->state == SSH_STATE_CLOSED)
10556 ssh->incoming_data_size += pktin->encrypted_len;
10557 if (!ssh->kex_in_progress &&
10558 ssh->max_data_size != 0 &&
10559 ssh->incoming_data_size > ssh->max_data_size)
10560 do_ssh2_transport(ssh, "too much data received", -1, NULL);
10564 ssh->packet_dispatch[pktin->type](ssh, pktin);
10565 else if (!ssh->protocol_initial_phase_done)
10566 do_ssh2_transport(ssh, in, inlen, pktin);
10568 do_ssh2_authconn(ssh, in, inlen, pktin);
10571 static void ssh2_bare_connection_protocol(Ssh ssh, void *vin, int inlen,
10572 struct Packet *pktin)
10574 unsigned char *in = (unsigned char *)vin;
10575 if (ssh->state == SSH_STATE_CLOSED)
10579 ssh->packet_dispatch[pktin->type](ssh, pktin);
10581 do_ssh2_authconn(ssh, in, inlen, pktin);
10584 static void ssh_cache_conf_values(Ssh ssh)
10586 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
10590 * Called to set up the connection.
10592 * Returns an error message, or NULL on success.
10594 static const char *ssh_init(void *frontend_handle, void **backend_handle,
10595 Conf *conf, char *host, int port, char **realhost,
10596 int nodelay, int keepalive)
10601 ssh = snew(struct ssh_tag);
10602 ssh->conf = conf_copy(conf);
10603 ssh_cache_conf_values(ssh);
10604 ssh->version = 0; /* when not ready yet */
10606 ssh->cipher = NULL;
10607 ssh->v1_cipher_ctx = NULL;
10608 ssh->crcda_ctx = NULL;
10609 ssh->cscipher = NULL;
10610 ssh->cs_cipher_ctx = NULL;
10611 ssh->sccipher = NULL;
10612 ssh->sc_cipher_ctx = NULL;
10614 ssh->cs_mac_ctx = NULL;
10616 ssh->sc_mac_ctx = NULL;
10617 ssh->cscomp = NULL;
10618 ssh->cs_comp_ctx = NULL;
10619 ssh->sccomp = NULL;
10620 ssh->sc_comp_ctx = NULL;
10622 ssh->kex_ctx = NULL;
10623 ssh->hostkey = NULL;
10624 ssh->hostkey_str = NULL;
10625 ssh->exitcode = -1;
10626 ssh->close_expected = FALSE;
10627 ssh->clean_exit = FALSE;
10628 ssh->state = SSH_STATE_PREPACKET;
10629 ssh->size_needed = FALSE;
10630 ssh->eof_needed = FALSE;
10632 ssh->logctx = NULL;
10633 ssh->deferred_send_data = NULL;
10634 ssh->deferred_len = 0;
10635 ssh->deferred_size = 0;
10636 ssh->fallback_cmd = 0;
10637 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
10638 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
10639 ssh->x11disp = NULL;
10640 ssh->x11auth = NULL;
10641 ssh->x11authtree = newtree234(x11_authcmp);
10642 ssh->v1_compressing = FALSE;
10643 ssh->v2_outgoing_sequence = 0;
10644 ssh->ssh1_rdpkt_crstate = 0;
10645 ssh->ssh2_rdpkt_crstate = 0;
10646 ssh->ssh2_bare_rdpkt_crstate = 0;
10647 ssh->ssh_gotdata_crstate = 0;
10648 ssh->do_ssh1_connection_crstate = 0;
10649 ssh->do_ssh_init_state = NULL;
10650 ssh->do_ssh_connection_init_state = NULL;
10651 ssh->do_ssh1_login_state = NULL;
10652 ssh->do_ssh2_transport_state = NULL;
10653 ssh->do_ssh2_authconn_state = NULL;
10656 ssh->mainchan = NULL;
10657 ssh->throttled_all = 0;
10658 ssh->v1_stdout_throttling = 0;
10660 ssh->queuelen = ssh->queuesize = 0;
10661 ssh->queueing = FALSE;
10662 ssh->qhead = ssh->qtail = NULL;
10663 ssh->deferred_rekey_reason = NULL;
10664 bufchain_init(&ssh->queued_incoming_data);
10665 ssh->frozen = FALSE;
10666 ssh->username = NULL;
10667 ssh->sent_console_eof = FALSE;
10668 ssh->got_pty = FALSE;
10669 ssh->bare_connection = FALSE;
10670 ssh->attempting_connshare = FALSE;
10672 *backend_handle = ssh;
10675 if (crypto_startup() == 0)
10676 return "Microsoft high encryption pack not installed!";
10679 ssh->frontend = frontend_handle;
10680 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
10681 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
10683 ssh->channels = NULL;
10684 ssh->rportfwds = NULL;
10685 ssh->portfwds = NULL;
10690 ssh->conn_throttle_count = 0;
10691 ssh->overall_bufsize = 0;
10692 ssh->fallback_cmd = 0;
10694 ssh->protocol = NULL;
10696 ssh->protocol_initial_phase_done = FALSE;
10698 ssh->pinger = NULL;
10700 ssh->incoming_data_size = ssh->outgoing_data_size =
10701 ssh->deferred_data_size = 0L;
10702 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10703 CONF_ssh_rekey_data));
10704 ssh->kex_in_progress = FALSE;
10707 ssh->gsslibs = NULL;
10710 random_ref(); /* do this now - may be needed by sharing setup code */
10712 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
10721 static void ssh_free(void *handle)
10723 Ssh ssh = (Ssh) handle;
10724 struct ssh_channel *c;
10725 struct ssh_rportfwd *pf;
10726 struct X11FakeAuth *auth;
10728 if (ssh->v1_cipher_ctx)
10729 ssh->cipher->free_context(ssh->v1_cipher_ctx);
10730 if (ssh->cs_cipher_ctx)
10731 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
10732 if (ssh->sc_cipher_ctx)
10733 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
10734 if (ssh->cs_mac_ctx)
10735 ssh->csmac->free_context(ssh->cs_mac_ctx);
10736 if (ssh->sc_mac_ctx)
10737 ssh->scmac->free_context(ssh->sc_mac_ctx);
10738 if (ssh->cs_comp_ctx) {
10740 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
10742 zlib_compress_cleanup(ssh->cs_comp_ctx);
10744 if (ssh->sc_comp_ctx) {
10746 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
10748 zlib_decompress_cleanup(ssh->sc_comp_ctx);
10751 dh_cleanup(ssh->kex_ctx);
10752 sfree(ssh->savedhost);
10754 while (ssh->queuelen-- > 0)
10755 ssh_free_packet(ssh->queue[ssh->queuelen]);
10758 while (ssh->qhead) {
10759 struct queued_handler *qh = ssh->qhead;
10760 ssh->qhead = qh->next;
10763 ssh->qhead = ssh->qtail = NULL;
10765 if (ssh->channels) {
10766 while ((c = delpos234(ssh->channels, 0)) != NULL) {
10769 if (c->u.x11.xconn != NULL)
10770 x11_close(c->u.x11.xconn);
10772 case CHAN_SOCKDATA:
10773 case CHAN_SOCKDATA_DORMANT:
10774 if (c->u.pfd.pf != NULL)
10775 pfd_close(c->u.pfd.pf);
10778 if (ssh->version == 2) {
10779 struct outstanding_channel_request *ocr, *nocr;
10780 ocr = c->v.v2.chanreq_head;
10782 ocr->handler(c, NULL, ocr->ctx);
10787 bufchain_clear(&c->v.v2.outbuffer);
10791 freetree234(ssh->channels);
10792 ssh->channels = NULL;
10795 if (ssh->connshare)
10796 sharestate_free(ssh->connshare);
10798 if (ssh->rportfwds) {
10799 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
10801 freetree234(ssh->rportfwds);
10802 ssh->rportfwds = NULL;
10804 sfree(ssh->deferred_send_data);
10806 x11_free_display(ssh->x11disp);
10807 while ((auth = delpos234(ssh->x11authtree, 0)) != NULL)
10808 x11_free_fake_auth(auth);
10809 freetree234(ssh->x11authtree);
10810 sfree(ssh->do_ssh_init_state);
10811 sfree(ssh->do_ssh1_login_state);
10812 sfree(ssh->do_ssh2_transport_state);
10813 sfree(ssh->do_ssh2_authconn_state);
10816 sfree(ssh->fullhostname);
10817 sfree(ssh->hostkey_str);
10818 if (ssh->crcda_ctx) {
10819 crcda_free_context(ssh->crcda_ctx);
10820 ssh->crcda_ctx = NULL;
10823 ssh_do_close(ssh, TRUE);
10824 expire_timer_context(ssh);
10826 pinger_free(ssh->pinger);
10827 bufchain_clear(&ssh->queued_incoming_data);
10828 sfree(ssh->username);
10829 conf_free(ssh->conf);
10832 ssh_gss_cleanup(ssh->gsslibs);
10840 * Reconfigure the SSH backend.
10842 static void ssh_reconfig(void *handle, Conf *conf)
10844 Ssh ssh = (Ssh) handle;
10845 char *rekeying = NULL, rekey_mandatory = FALSE;
10846 unsigned long old_max_data_size;
10849 pinger_reconfig(ssh->pinger, ssh->conf, conf);
10851 ssh_setup_portfwd(ssh, conf);
10853 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
10854 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
10856 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
10857 unsigned long now = GETTICKCOUNT();
10859 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
10860 rekeying = "timeout shortened";
10862 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
10866 old_max_data_size = ssh->max_data_size;
10867 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10868 CONF_ssh_rekey_data));
10869 if (old_max_data_size != ssh->max_data_size &&
10870 ssh->max_data_size != 0) {
10871 if (ssh->outgoing_data_size > ssh->max_data_size ||
10872 ssh->incoming_data_size > ssh->max_data_size)
10873 rekeying = "data limit lowered";
10876 if (conf_get_int(ssh->conf, CONF_compression) !=
10877 conf_get_int(conf, CONF_compression)) {
10878 rekeying = "compression setting changed";
10879 rekey_mandatory = TRUE;
10882 for (i = 0; i < CIPHER_MAX; i++)
10883 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
10884 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
10885 rekeying = "cipher settings changed";
10886 rekey_mandatory = TRUE;
10888 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
10889 conf_get_int(conf, CONF_ssh2_des_cbc)) {
10890 rekeying = "cipher settings changed";
10891 rekey_mandatory = TRUE;
10894 conf_free(ssh->conf);
10895 ssh->conf = conf_copy(conf);
10896 ssh_cache_conf_values(ssh);
10898 if (!ssh->bare_connection && rekeying) {
10899 if (!ssh->kex_in_progress) {
10900 do_ssh2_transport(ssh, rekeying, -1, NULL);
10901 } else if (rekey_mandatory) {
10902 ssh->deferred_rekey_reason = rekeying;
10908 * Called to send data down the SSH connection.
10910 static int ssh_send(void *handle, char *buf, int len)
10912 Ssh ssh = (Ssh) handle;
10914 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10917 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
10919 return ssh_sendbuffer(ssh);
10923 * Called to query the current amount of buffered stdin data.
10925 static int ssh_sendbuffer(void *handle)
10927 Ssh ssh = (Ssh) handle;
10928 int override_value;
10930 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10934 * If the SSH socket itself has backed up, add the total backup
10935 * size on that to any individual buffer on the stdin channel.
10937 override_value = 0;
10938 if (ssh->throttled_all)
10939 override_value = ssh->overall_bufsize;
10941 if (ssh->version == 1) {
10942 return override_value;
10943 } else if (ssh->version == 2) {
10944 if (!ssh->mainchan)
10945 return override_value;
10947 return (override_value +
10948 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
10955 * Called to set the size of the window from SSH's POV.
10957 static void ssh_size(void *handle, int width, int height)
10959 Ssh ssh = (Ssh) handle;
10960 struct Packet *pktout;
10962 ssh->term_width = width;
10963 ssh->term_height = height;
10965 switch (ssh->state) {
10966 case SSH_STATE_BEFORE_SIZE:
10967 case SSH_STATE_PREPACKET:
10968 case SSH_STATE_CLOSED:
10969 break; /* do nothing */
10970 case SSH_STATE_INTERMED:
10971 ssh->size_needed = TRUE; /* buffer for later */
10973 case SSH_STATE_SESSION:
10974 if (!conf_get_int(ssh->conf, CONF_nopty)) {
10975 if (ssh->version == 1) {
10976 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
10977 PKT_INT, ssh->term_height,
10978 PKT_INT, ssh->term_width,
10979 PKT_INT, 0, PKT_INT, 0, PKT_END);
10980 } else if (ssh->mainchan) {
10981 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
10983 ssh2_pkt_adduint32(pktout, ssh->term_width);
10984 ssh2_pkt_adduint32(pktout, ssh->term_height);
10985 ssh2_pkt_adduint32(pktout, 0);
10986 ssh2_pkt_adduint32(pktout, 0);
10987 ssh2_pkt_send(ssh, pktout);
10995 * Return a list of the special codes that make sense in this
10998 static const struct telnet_special *ssh_get_specials(void *handle)
11000 static const struct telnet_special ssh1_ignore_special[] = {
11001 {"IGNORE message", TS_NOP}
11003 static const struct telnet_special ssh2_ignore_special[] = {
11004 {"IGNORE message", TS_NOP},
11006 static const struct telnet_special ssh2_rekey_special[] = {
11007 {"Repeat key exchange", TS_REKEY},
11009 static const struct telnet_special ssh2_session_specials[] = {
11012 /* These are the signal names defined by RFC 4254.
11013 * They include all the ISO C signals, but are a subset of the POSIX
11014 * required signals. */
11015 {"SIGINT (Interrupt)", TS_SIGINT},
11016 {"SIGTERM (Terminate)", TS_SIGTERM},
11017 {"SIGKILL (Kill)", TS_SIGKILL},
11018 {"SIGQUIT (Quit)", TS_SIGQUIT},
11019 {"SIGHUP (Hangup)", TS_SIGHUP},
11020 {"More signals", TS_SUBMENU},
11021 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
11022 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
11023 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
11024 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
11025 {NULL, TS_EXITMENU}
11027 static const struct telnet_special specials_end[] = {
11028 {NULL, TS_EXITMENU}
11030 /* XXX review this length for any changes: */
11031 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
11032 lenof(ssh2_rekey_special) +
11033 lenof(ssh2_session_specials) +
11034 lenof(specials_end)];
11035 Ssh ssh = (Ssh) handle;
11037 #define ADD_SPECIALS(name) \
11039 assert((i + lenof(name)) <= lenof(ssh_specials)); \
11040 memcpy(&ssh_specials[i], name, sizeof name); \
11041 i += lenof(name); \
11044 if (ssh->version == 1) {
11045 /* Don't bother offering IGNORE if we've decided the remote
11046 * won't cope with it, since we wouldn't bother sending it if
11048 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11049 ADD_SPECIALS(ssh1_ignore_special);
11050 } else if (ssh->version == 2) {
11051 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
11052 ADD_SPECIALS(ssh2_ignore_special);
11053 if (!(ssh->remote_bugs & BUG_SSH2_REKEY) && !ssh->bare_connection)
11054 ADD_SPECIALS(ssh2_rekey_special);
11056 ADD_SPECIALS(ssh2_session_specials);
11057 } /* else we're not ready yet */
11060 ADD_SPECIALS(specials_end);
11061 return ssh_specials;
11065 #undef ADD_SPECIALS
11069 * Send special codes. TS_EOF is useful for `plink', so you
11070 * can send an EOF and collect resulting output (e.g. `plink
11073 static void ssh_special(void *handle, Telnet_Special code)
11075 Ssh ssh = (Ssh) handle;
11076 struct Packet *pktout;
11078 if (code == TS_EOF) {
11079 if (ssh->state != SSH_STATE_SESSION) {
11081 * Buffer the EOF in case we are pre-SESSION, so we can
11082 * send it as soon as we reach SESSION.
11084 if (code == TS_EOF)
11085 ssh->eof_needed = TRUE;
11088 if (ssh->version == 1) {
11089 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
11090 } else if (ssh->mainchan) {
11091 sshfwd_write_eof(ssh->mainchan);
11092 ssh->send_ok = 0; /* now stop trying to read from stdin */
11094 logevent("Sent EOF message");
11095 } else if (code == TS_PING || code == TS_NOP) {
11096 if (ssh->state == SSH_STATE_CLOSED
11097 || ssh->state == SSH_STATE_PREPACKET) return;
11098 if (ssh->version == 1) {
11099 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11100 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
11102 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
11103 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
11104 ssh2_pkt_addstring_start(pktout);
11105 ssh2_pkt_send_noqueue(ssh, pktout);
11108 } else if (code == TS_REKEY) {
11109 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11110 ssh->version == 2) {
11111 do_ssh2_transport(ssh, "at user request", -1, NULL);
11113 } else if (code == TS_BRK) {
11114 if (ssh->state == SSH_STATE_CLOSED
11115 || ssh->state == SSH_STATE_PREPACKET) return;
11116 if (ssh->version == 1) {
11117 logevent("Unable to send BREAK signal in SSH-1");
11118 } else if (ssh->mainchan) {
11119 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
11120 ssh2_pkt_adduint32(pktout, 0); /* default break length */
11121 ssh2_pkt_send(ssh, pktout);
11124 /* Is is a POSIX signal? */
11125 char *signame = NULL;
11126 if (code == TS_SIGABRT) signame = "ABRT";
11127 if (code == TS_SIGALRM) signame = "ALRM";
11128 if (code == TS_SIGFPE) signame = "FPE";
11129 if (code == TS_SIGHUP) signame = "HUP";
11130 if (code == TS_SIGILL) signame = "ILL";
11131 if (code == TS_SIGINT) signame = "INT";
11132 if (code == TS_SIGKILL) signame = "KILL";
11133 if (code == TS_SIGPIPE) signame = "PIPE";
11134 if (code == TS_SIGQUIT) signame = "QUIT";
11135 if (code == TS_SIGSEGV) signame = "SEGV";
11136 if (code == TS_SIGTERM) signame = "TERM";
11137 if (code == TS_SIGUSR1) signame = "USR1";
11138 if (code == TS_SIGUSR2) signame = "USR2";
11139 /* The SSH-2 protocol does in principle support arbitrary named
11140 * signals, including signame@domain, but we don't support those. */
11142 /* It's a signal. */
11143 if (ssh->version == 2 && ssh->mainchan) {
11144 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
11145 ssh2_pkt_addstring(pktout, signame);
11146 ssh2_pkt_send(ssh, pktout);
11147 logeventf(ssh, "Sent signal SIG%s", signame);
11150 /* Never heard of it. Do nothing */
11155 void *new_sock_channel(void *handle, struct PortForwarding *pf)
11157 Ssh ssh = (Ssh) handle;
11158 struct ssh_channel *c;
11159 c = snew(struct ssh_channel);
11162 ssh2_channel_init(c);
11163 c->halfopen = TRUE;
11164 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
11166 add234(ssh->channels, c);
11170 unsigned ssh_alloc_sharing_channel(Ssh ssh, void *sharing_ctx)
11172 struct ssh_channel *c;
11173 c = snew(struct ssh_channel);
11176 ssh2_channel_init(c);
11177 c->type = CHAN_SHARING;
11178 c->u.sharing.ctx = sharing_ctx;
11179 add234(ssh->channels, c);
11183 void ssh_delete_sharing_channel(Ssh ssh, unsigned localid)
11185 struct ssh_channel *c;
11187 c = find234(ssh->channels, &localid, ssh_channelfind);
11189 ssh_channel_destroy(c);
11192 void ssh_send_packet_from_downstream(Ssh ssh, unsigned id, int type,
11193 const void *data, int datalen,
11194 const char *additional_log_text)
11196 struct Packet *pkt;
11198 pkt = ssh2_pkt_init(type);
11199 pkt->downstream_id = id;
11200 pkt->additional_log_text = additional_log_text;
11201 ssh2_pkt_adddata(pkt, data, datalen);
11202 ssh2_pkt_send(ssh, pkt);
11206 * This is called when stdout/stderr (the entity to which
11207 * from_backend sends data) manages to clear some backlog.
11209 static void ssh_unthrottle(void *handle, int bufsize)
11211 Ssh ssh = (Ssh) handle;
11214 if (ssh->version == 1) {
11215 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
11216 ssh->v1_stdout_throttling = 0;
11217 ssh_throttle_conn(ssh, -1);
11220 if (ssh->mainchan) {
11221 ssh2_set_window(ssh->mainchan,
11222 bufsize < ssh->mainchan->v.v2.locmaxwin ?
11223 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
11224 if (ssh_is_simple(ssh))
11227 buflimit = ssh->mainchan->v.v2.locmaxwin;
11228 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
11229 ssh->mainchan->throttling_conn = 0;
11230 ssh_throttle_conn(ssh, -1);
11236 * Now process any SSH connection data that was stashed in our
11237 * queue while we were frozen.
11239 ssh_process_queued_incoming_data(ssh);
11242 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
11244 struct ssh_channel *c = (struct ssh_channel *)channel;
11246 struct Packet *pktout;
11248 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
11250 if (ssh->version == 1) {
11251 send_packet(ssh, SSH1_MSG_PORT_OPEN,
11252 PKT_INT, c->localid,
11255 /* PKT_STR, <org:orgport>, */
11258 pktout = ssh2_chanopen_init(c, "direct-tcpip");
11260 char *trimmed_host = host_strduptrim(hostname);
11261 ssh2_pkt_addstring(pktout, trimmed_host);
11262 sfree(trimmed_host);
11264 ssh2_pkt_adduint32(pktout, port);
11266 * We make up values for the originator data; partly it's
11267 * too much hassle to keep track, and partly I'm not
11268 * convinced the server should be told details like that
11269 * about my local network configuration.
11270 * The "originator IP address" is syntactically a numeric
11271 * IP address, and some servers (e.g., Tectia) get upset
11272 * if it doesn't match this syntax.
11274 ssh2_pkt_addstring(pktout, "0.0.0.0");
11275 ssh2_pkt_adduint32(pktout, 0);
11276 ssh2_pkt_send(ssh, pktout);
11280 static int ssh_connected(void *handle)
11282 Ssh ssh = (Ssh) handle;
11283 return ssh->s != NULL;
11286 static int ssh_sendok(void *handle)
11288 Ssh ssh = (Ssh) handle;
11289 return ssh->send_ok;
11292 static int ssh_ldisc(void *handle, int option)
11294 Ssh ssh = (Ssh) handle;
11295 if (option == LD_ECHO)
11296 return ssh->echoing;
11297 if (option == LD_EDIT)
11298 return ssh->editing;
11302 static void ssh_provide_ldisc(void *handle, void *ldisc)
11304 Ssh ssh = (Ssh) handle;
11305 ssh->ldisc = ldisc;
11308 static void ssh_provide_logctx(void *handle, void *logctx)
11310 Ssh ssh = (Ssh) handle;
11311 ssh->logctx = logctx;
11314 static int ssh_return_exitcode(void *handle)
11316 Ssh ssh = (Ssh) handle;
11317 if (ssh->s != NULL)
11320 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
11324 * cfg_info for SSH is the currently running version of the
11325 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
11327 static int ssh_cfg_info(void *handle)
11329 Ssh ssh = (Ssh) handle;
11330 return ssh->version;
11334 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
11335 * that fails. This variable is the means by which scp.c can reach
11336 * into the SSH code and find out which one it got.
11338 extern int ssh_fallback_cmd(void *handle)
11340 Ssh ssh = (Ssh) handle;
11341 return ssh->fallback_cmd;
11344 Backend ssh_backend = {
11354 ssh_return_exitcode,
11358 ssh_provide_logctx,