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) ||
2827 wc_match("dropbear_0.[2-4][0-9]*", imp) ||
2828 wc_match("dropbear_0.5[01]*", imp)))) {
2830 * These versions have the SSH-2 channel request bug.
2831 * OpenSSH 6.7 and above do not:
2832 * https://bugzilla.mindrot.org/show_bug.cgi?id=1818
2833 * dropbear_0.52 and above do not:
2834 * https://secure.ucc.asn.au/hg/dropbear/rev/cd02449b709c
2836 ssh->remote_bugs |= BUG_SENDS_LATE_REQUEST_REPLY;
2837 logevent("We believe remote version has SSH-2 channel request bug");
2842 * The `software version' part of an SSH version string is required
2843 * to contain no spaces or minus signs.
2845 static void ssh_fix_verstring(char *str)
2847 /* Eat "<protoversion>-". */
2848 while (*str && *str != '-') str++;
2849 assert(*str == '-'); str++;
2851 /* Convert minus signs and spaces in the remaining string into
2854 if (*str == '-' || *str == ' ')
2861 * Send an appropriate SSH version string.
2863 static void ssh_send_verstring(Ssh ssh, const char *protoname, char *svers)
2867 if (ssh->version == 2) {
2869 * Construct a v2 version string.
2871 verstring = dupprintf("%s2.0-%s\015\012", protoname, sshver);
2874 * Construct a v1 version string.
2876 assert(!strcmp(protoname, "SSH-")); /* no v1 bare connection protocol */
2877 verstring = dupprintf("SSH-%s-%s\012",
2878 (ssh_versioncmp(svers, "1.5") <= 0 ?
2883 ssh_fix_verstring(verstring + strlen(protoname));
2885 if (ssh->version == 2) {
2888 * Record our version string.
2890 len = strcspn(verstring, "\015\012");
2891 ssh->v_c = snewn(len + 1, char);
2892 memcpy(ssh->v_c, verstring, len);
2896 logeventf(ssh, "We claim version: %.*s",
2897 strcspn(verstring, "\015\012"), verstring);
2898 s_write(ssh, verstring, strlen(verstring));
2902 static int do_ssh_init(Ssh ssh, unsigned char c)
2904 static const char protoname[] = "SSH-";
2906 struct do_ssh_init_state {
2915 crState(do_ssh_init_state);
2919 /* Search for a line beginning with the protocol name prefix in
2922 for (s->i = 0; protoname[s->i]; s->i++) {
2923 if ((char)c != protoname[s->i]) goto no;
2933 s->vstrsize = sizeof(protoname) + 16;
2934 s->vstring = snewn(s->vstrsize, char);
2935 strcpy(s->vstring, protoname);
2936 s->vslen = strlen(protoname);
2939 if (s->vslen >= s->vstrsize - 1) {
2941 s->vstring = sresize(s->vstring, s->vstrsize, char);
2943 s->vstring[s->vslen++] = c;
2946 s->version[s->i] = '\0';
2948 } else if (s->i < sizeof(s->version) - 1)
2949 s->version[s->i++] = c;
2950 } else if (c == '\012')
2952 crReturn(1); /* get another char */
2955 ssh->agentfwd_enabled = FALSE;
2956 ssh->rdpkt2_state.incoming_sequence = 0;
2958 s->vstring[s->vslen] = 0;
2959 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2960 logeventf(ssh, "Server version: %s", s->vstring);
2961 ssh_detect_bugs(ssh, s->vstring);
2964 * Decide which SSH protocol version to support.
2967 /* Anything strictly below "2.0" means protocol 1 is supported. */
2968 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2969 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2970 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2972 if (conf_get_int(ssh->conf, CONF_sshprot) == 0 && !s->proto1) {
2973 bombout(("SSH protocol version 1 required by configuration but "
2974 "not provided by server"));
2977 if (conf_get_int(ssh->conf, CONF_sshprot) == 3 && !s->proto2) {
2978 bombout(("SSH protocol version 2 required by configuration but "
2979 "not provided by server"));
2983 if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1))
2988 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2990 /* Send the version string, if we haven't already */
2991 if (conf_get_int(ssh->conf, CONF_sshprot) != 3)
2992 ssh_send_verstring(ssh, protoname, s->version);
2994 if (ssh->version == 2) {
2997 * Record their version string.
2999 len = strcspn(s->vstring, "\015\012");
3000 ssh->v_s = snewn(len + 1, char);
3001 memcpy(ssh->v_s, s->vstring, len);
3005 * Initialise SSH-2 protocol.
3007 ssh->protocol = ssh2_protocol;
3008 ssh2_protocol_setup(ssh);
3009 ssh->s_rdpkt = ssh2_rdpkt;
3012 * Initialise SSH-1 protocol.
3014 ssh->protocol = ssh1_protocol;
3015 ssh1_protocol_setup(ssh);
3016 ssh->s_rdpkt = ssh1_rdpkt;
3018 if (ssh->version == 2)
3019 do_ssh2_transport(ssh, NULL, -1, NULL);
3021 update_specials_menu(ssh->frontend);
3022 ssh->state = SSH_STATE_BEFORE_SIZE;
3023 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3030 static int do_ssh_connection_init(Ssh ssh, unsigned char c)
3033 * Ordinary SSH begins with the banner "SSH-x.y-...". This is just
3034 * the ssh-connection part, extracted and given a trivial binary
3035 * packet protocol, so we replace 'SSH-' at the start with a new
3036 * name. In proper SSH style (though of course this part of the
3037 * proper SSH protocol _isn't_ subject to this kind of
3038 * DNS-domain-based extension), we define the new name in our
3041 static const char protoname[] =
3042 "SSHCONNECTION@putty.projects.tartarus.org-";
3044 struct do_ssh_connection_init_state {
3052 crState(do_ssh_connection_init_state);
3056 /* Search for a line beginning with the protocol name prefix in
3059 for (s->i = 0; protoname[s->i]; s->i++) {
3060 if ((char)c != protoname[s->i]) goto no;
3070 s->vstrsize = sizeof(protoname) + 16;
3071 s->vstring = snewn(s->vstrsize, char);
3072 strcpy(s->vstring, protoname);
3073 s->vslen = strlen(protoname);
3076 if (s->vslen >= s->vstrsize - 1) {
3078 s->vstring = sresize(s->vstring, s->vstrsize, char);
3080 s->vstring[s->vslen++] = c;
3083 s->version[s->i] = '\0';
3085 } else if (s->i < sizeof(s->version) - 1)
3086 s->version[s->i++] = c;
3087 } else if (c == '\012')
3089 crReturn(1); /* get another char */
3092 ssh->agentfwd_enabled = FALSE;
3093 ssh->rdpkt2_bare_state.incoming_sequence = 0;
3095 s->vstring[s->vslen] = 0;
3096 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
3097 logeventf(ssh, "Server version: %s", s->vstring);
3098 ssh_detect_bugs(ssh, s->vstring);
3101 * Decide which SSH protocol version to support. This is easy in
3102 * bare ssh-connection mode: only 2.0 is legal.
3104 if (ssh_versioncmp(s->version, "2.0") < 0) {
3105 bombout(("Server announces compatibility with SSH-1 in bare ssh-connection protocol"));
3108 if (conf_get_int(ssh->conf, CONF_sshprot) == 0) {
3109 bombout(("Bare ssh-connection protocol cannot be run in SSH-1-only mode"));
3115 logeventf(ssh, "Using bare ssh-connection protocol");
3117 /* Send the version string, if we haven't already */
3118 ssh_send_verstring(ssh, protoname, s->version);
3121 * Initialise bare connection protocol.
3123 ssh->protocol = ssh2_bare_connection_protocol;
3124 ssh2_bare_connection_protocol_setup(ssh);
3125 ssh->s_rdpkt = ssh2_bare_connection_rdpkt;
3127 update_specials_menu(ssh->frontend);
3128 ssh->state = SSH_STATE_BEFORE_SIZE;
3129 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3132 * Get authconn (really just conn) under way.
3134 do_ssh2_authconn(ssh, NULL, 0, NULL);
3141 static void ssh_process_incoming_data(Ssh ssh,
3142 unsigned char **data, int *datalen)
3144 struct Packet *pktin;
3146 pktin = ssh->s_rdpkt(ssh, data, datalen);
3148 ssh->protocol(ssh, NULL, 0, pktin);
3149 ssh_free_packet(pktin);
3153 static void ssh_queue_incoming_data(Ssh ssh,
3154 unsigned char **data, int *datalen)
3156 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
3161 static void ssh_process_queued_incoming_data(Ssh ssh)
3164 unsigned char *data;
3167 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
3168 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
3172 while (!ssh->frozen && len > 0)
3173 ssh_process_incoming_data(ssh, &data, &len);
3176 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
3180 static void ssh_set_frozen(Ssh ssh, int frozen)
3183 sk_set_frozen(ssh->s, frozen);
3184 ssh->frozen = frozen;
3187 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
3189 /* Log raw data, if we're in that mode. */
3191 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
3192 0, NULL, NULL, 0, NULL);
3194 crBegin(ssh->ssh_gotdata_crstate);
3197 * To begin with, feed the characters one by one to the
3198 * protocol initialisation / selection function do_ssh_init().
3199 * When that returns 0, we're done with the initial greeting
3200 * exchange and can move on to packet discipline.
3203 int ret; /* need not be kept across crReturn */
3205 crReturnV; /* more data please */
3206 ret = ssh->do_ssh_init(ssh, *data);
3214 * We emerge from that loop when the initial negotiation is
3215 * over and we have selected an s_rdpkt function. Now pass
3216 * everything to s_rdpkt, and then pass the resulting packets
3217 * to the proper protocol handler.
3221 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
3223 ssh_queue_incoming_data(ssh, &data, &datalen);
3224 /* This uses up all data and cannot cause anything interesting
3225 * to happen; indeed, for anything to happen at all, we must
3226 * return, so break out. */
3228 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
3229 /* This uses up some or all data, and may freeze the
3231 ssh_process_queued_incoming_data(ssh);
3233 /* This uses up some or all data, and may freeze the
3235 ssh_process_incoming_data(ssh, &data, &datalen);
3237 /* FIXME this is probably EBW. */
3238 if (ssh->state == SSH_STATE_CLOSED)
3241 /* We're out of data. Go and get some more. */
3247 static int ssh_do_close(Ssh ssh, int notify_exit)
3250 struct ssh_channel *c;
3252 ssh->state = SSH_STATE_CLOSED;
3253 expire_timer_context(ssh);
3258 notify_remote_exit(ssh->frontend);
3263 * Now we must shut down any port- and X-forwarded channels going
3264 * through this connection.
3266 if (ssh->channels) {
3267 while (NULL != (c = index234(ssh->channels, 0))) {
3270 x11_close(c->u.x11.xconn);
3273 case CHAN_SOCKDATA_DORMANT:
3274 pfd_close(c->u.pfd.pf);
3277 del234(ssh->channels, c); /* moving next one to index 0 */
3278 if (ssh->version == 2)
3279 bufchain_clear(&c->v.v2.outbuffer);
3284 * Go through port-forwardings, and close any associated
3285 * listening sockets.
3287 if (ssh->portfwds) {
3288 struct ssh_portfwd *pf;
3289 while (NULL != (pf = index234(ssh->portfwds, 0))) {
3290 /* Dispose of any listening socket. */
3292 pfl_terminate(pf->local);
3293 del234(ssh->portfwds, pf); /* moving next one to index 0 */
3296 freetree234(ssh->portfwds);
3297 ssh->portfwds = NULL;
3301 * Also stop attempting to connection-share.
3303 if (ssh->connshare) {
3304 sharestate_free(ssh->connshare);
3305 ssh->connshare = NULL;
3311 static void ssh_socket_log(Plug plug, int type, SockAddr addr, int port,
3312 const char *error_msg, int error_code)
3314 Ssh ssh = (Ssh) plug;
3315 char addrbuf[256], *msg;
3317 if (ssh->attempting_connshare) {
3319 * While we're attempting connection sharing, don't loudly log
3320 * everything that happens. Real TCP connections need to be
3321 * logged when we _start_ trying to connect, because it might
3322 * be ages before they respond if something goes wrong; but
3323 * connection sharing is local and quick to respond, and it's
3324 * sufficient to simply wait and see whether it worked
3328 sk_getaddr(addr, addrbuf, lenof(addrbuf));
3331 if (sk_addr_needs_port(addr)) {
3332 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
3334 msg = dupprintf("Connecting to %s", addrbuf);
3337 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
3345 void ssh_connshare_log(Ssh ssh, int event, const char *logtext,
3346 const char *ds_err, const char *us_err)
3348 if (event == SHARE_NONE) {
3349 /* In this case, 'logtext' is an error message indicating a
3350 * reason why connection sharing couldn't be set up _at all_.
3351 * Failing that, ds_err and us_err indicate why we couldn't be
3352 * a downstream and an upstream respectively. */
3354 logeventf(ssh, "Could not set up connection sharing: %s", logtext);
3357 logeventf(ssh, "Could not set up connection sharing"
3358 " as downstream: %s", ds_err);
3360 logeventf(ssh, "Could not set up connection sharing"
3361 " as upstream: %s", us_err);
3363 } else if (event == SHARE_DOWNSTREAM) {
3364 /* In this case, 'logtext' is a local endpoint address */
3365 logeventf(ssh, "Using existing shared connection at %s", logtext);
3366 /* Also we should mention this in the console window to avoid
3367 * confusing users as to why this window doesn't behave the
3369 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3370 c_write_str(ssh,"Reusing a shared connection to this server.\r\n");
3372 } else if (event == SHARE_UPSTREAM) {
3373 /* In this case, 'logtext' is a local endpoint address too */
3374 logeventf(ssh, "Sharing this connection at %s", logtext);
3378 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
3381 Ssh ssh = (Ssh) plug;
3382 int need_notify = ssh_do_close(ssh, FALSE);
3385 if (!ssh->close_expected)
3386 error_msg = "Server unexpectedly closed network connection";
3388 error_msg = "Server closed network connection";
3391 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
3395 notify_remote_exit(ssh->frontend);
3398 logevent(error_msg);
3399 if (!ssh->close_expected || !ssh->clean_exit)
3400 connection_fatal(ssh->frontend, "%s", error_msg);
3404 static int ssh_receive(Plug plug, int urgent, char *data, int len)
3406 Ssh ssh = (Ssh) plug;
3407 ssh_gotdata(ssh, (unsigned char *)data, len);
3408 if (ssh->state == SSH_STATE_CLOSED) {
3409 ssh_do_close(ssh, TRUE);
3415 static void ssh_sent(Plug plug, int bufsize)
3417 Ssh ssh = (Ssh) plug;
3419 * If the send backlog on the SSH socket itself clears, we
3420 * should unthrottle the whole world if it was throttled.
3422 if (bufsize < SSH_MAX_BACKLOG)
3423 ssh_throttle_all(ssh, 0, bufsize);
3427 * Connect to specified host and port.
3428 * Returns an error message, or NULL on success.
3429 * Also places the canonical host name into `realhost'. It must be
3430 * freed by the caller.
3432 static const char *connect_to_host(Ssh ssh, char *host, int port,
3433 char **realhost, int nodelay, int keepalive)
3435 static const struct plug_function_table fn_table = {
3446 int addressfamily, sshprot;
3448 loghost = conf_get_str(ssh->conf, CONF_loghost);
3453 tmphost = dupstr(loghost);
3454 ssh->savedport = 22; /* default ssh port */
3457 * A colon suffix on the hostname string also lets us affect
3458 * savedport. (Unless there are multiple colons, in which case
3459 * we assume this is an unbracketed IPv6 literal.)
3461 colon = host_strrchr(tmphost, ':');
3462 if (colon && colon == host_strchr(tmphost, ':')) {
3465 ssh->savedport = atoi(colon);
3468 ssh->savedhost = host_strduptrim(tmphost);
3471 ssh->savedhost = host_strduptrim(host);
3473 port = 22; /* default ssh port */
3474 ssh->savedport = port;
3477 ssh->fn = &fn_table; /* make 'ssh' usable as a Plug */
3480 * Try connection-sharing, in case that means we don't open a
3481 * socket after all. ssh_connection_sharing_init will connect to a
3482 * previously established upstream if it can, and failing that,
3483 * establish a listening socket for _us_ to be the upstream. In
3484 * the latter case it will return NULL just as if it had done
3485 * nothing, because here we only need to care if we're a
3486 * downstream and need to do our connection setup differently.
3488 ssh->connshare = NULL;
3489 ssh->attempting_connshare = TRUE; /* affects socket logging behaviour */
3490 ssh->s = ssh_connection_sharing_init(ssh->savedhost, ssh->savedport,
3491 ssh->conf, ssh, &ssh->connshare);
3492 ssh->attempting_connshare = FALSE;
3493 if (ssh->s != NULL) {
3495 * We are a downstream.
3497 ssh->bare_connection = TRUE;
3498 ssh->do_ssh_init = do_ssh_connection_init;
3499 ssh->fullhostname = NULL;
3500 *realhost = dupstr(host); /* best we can do */
3503 * We're not a downstream, so open a normal socket.
3505 ssh->do_ssh_init = do_ssh_init;
3510 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
3511 logeventf(ssh, "Looking up host \"%s\"%s", host,
3512 (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
3513 (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
3514 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily);
3515 if ((err = sk_addr_error(addr)) != NULL) {
3519 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3521 ssh->s = new_connection(addr, *realhost, port,
3522 0, 1, nodelay, keepalive,
3523 (Plug) ssh, ssh->conf);
3524 if ((err = sk_socket_error(ssh->s)) != NULL) {
3526 notify_remote_exit(ssh->frontend);
3532 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3533 * send the version string too.
3535 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3538 if (sshprot == 3 && !ssh->bare_connection) {
3540 ssh_send_verstring(ssh, "SSH-", NULL);
3544 * loghost, if configured, overrides realhost.
3548 *realhost = dupstr(loghost);
3555 * Throttle or unthrottle the SSH connection.
3557 static void ssh_throttle_conn(Ssh ssh, int adjust)
3559 int old_count = ssh->conn_throttle_count;
3560 ssh->conn_throttle_count += adjust;
3561 assert(ssh->conn_throttle_count >= 0);
3562 if (ssh->conn_throttle_count && !old_count) {
3563 ssh_set_frozen(ssh, 1);
3564 } else if (!ssh->conn_throttle_count && old_count) {
3565 ssh_set_frozen(ssh, 0);
3570 * Throttle or unthrottle _all_ local data streams (for when sends
3571 * on the SSH connection itself back up).
3573 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3576 struct ssh_channel *c;
3578 if (enable == ssh->throttled_all)
3580 ssh->throttled_all = enable;
3581 ssh->overall_bufsize = bufsize;
3584 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3586 case CHAN_MAINSESSION:
3588 * This is treated separately, outside the switch.
3592 x11_override_throttle(c->u.x11.xconn, enable);
3595 /* Agent channels require no buffer management. */
3598 pfd_override_throttle(c->u.pfd.pf, enable);
3604 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3606 Ssh ssh = (Ssh) sshv;
3608 ssh->agent_response = reply;
3609 ssh->agent_response_len = replylen;
3611 if (ssh->version == 1)
3612 do_ssh1_login(ssh, NULL, -1, NULL);
3614 do_ssh2_authconn(ssh, NULL, -1, NULL);
3617 static void ssh_dialog_callback(void *sshv, int ret)
3619 Ssh ssh = (Ssh) sshv;
3621 ssh->user_response = ret;
3623 if (ssh->version == 1)
3624 do_ssh1_login(ssh, NULL, -1, NULL);
3626 do_ssh2_transport(ssh, NULL, -1, NULL);
3629 * This may have unfrozen the SSH connection, so do a
3632 ssh_process_queued_incoming_data(ssh);
3635 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3637 struct ssh_channel *c = (struct ssh_channel *)cv;
3639 void *sentreply = reply;
3641 c->u.a.outstanding_requests--;
3643 /* Fake SSH_AGENT_FAILURE. */
3644 sentreply = "\0\0\0\1\5";
3647 if (ssh->version == 2) {
3648 ssh2_add_channel_data(c, sentreply, replylen);
3651 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3652 PKT_INT, c->remoteid,
3654 PKT_DATA, sentreply, replylen,
3660 * If we've already seen an incoming EOF but haven't sent an
3661 * outgoing one, this may be the moment to send it.
3663 if (c->u.a.outstanding_requests == 0 && (c->closes & CLOSES_RCVD_EOF))
3664 sshfwd_write_eof(c);
3668 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3669 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3670 * => log `wire_reason'.
3672 static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
3673 int code, int clean_exit)
3677 client_reason = wire_reason;
3679 error = dupprintf("Disconnected: %s", client_reason);
3681 error = dupstr("Disconnected");
3683 if (ssh->version == 1) {
3684 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3686 } else if (ssh->version == 2) {
3687 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3688 ssh2_pkt_adduint32(pktout, code);
3689 ssh2_pkt_addstring(pktout, wire_reason);
3690 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3691 ssh2_pkt_send_noqueue(ssh, pktout);
3694 ssh->close_expected = TRUE;
3695 ssh->clean_exit = clean_exit;
3696 ssh_closing((Plug)ssh, error, 0, 0);
3700 int verify_ssh_manual_host_key(Ssh ssh, const char *fingerprint,
3701 const struct ssh_signkey *ssh2keytype,
3704 if (!conf_get_str_nthstrkey(ssh->conf, CONF_ssh_manual_hostkeys, 0)) {
3705 return -1; /* no manual keys configured */
3710 * The fingerprint string we've been given will have things
3711 * like 'ssh-rsa 2048' at the front of it. Strip those off and
3712 * narrow down to just the colon-separated hex block at the
3713 * end of the string.
3715 const char *p = strrchr(fingerprint, ' ');
3716 fingerprint = p ? p+1 : fingerprint;
3717 /* Quick sanity checks, including making sure it's in lowercase */
3718 assert(strlen(fingerprint) == 16*3 - 1);
3719 assert(fingerprint[2] == ':');
3720 assert(fingerprint[strspn(fingerprint, "0123456789abcdef:")] == 0);
3722 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3724 return 1; /* success */
3729 * Construct the base64-encoded public key blob and see if
3732 unsigned char *binblob;
3734 int binlen, atoms, i;
3735 binblob = ssh2keytype->public_blob(ssh2keydata, &binlen);
3736 atoms = (binlen + 2) / 3;
3737 base64blob = snewn(atoms * 4 + 1, char);
3738 for (i = 0; i < atoms; i++)
3739 base64_encode_atom(binblob + 3*i, binlen - 3*i, base64blob + 4*i);
3740 base64blob[atoms * 4] = '\0';
3742 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3745 return 1; /* success */
3754 * Handle the key exchange and user authentication phases.
3756 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
3757 struct Packet *pktin)
3760 unsigned char cookie[8], *ptr;
3761 struct MD5Context md5c;
3762 struct do_ssh1_login_state {
3765 unsigned char *rsabuf, *keystr1, *keystr2;
3766 unsigned long supported_ciphers_mask, supported_auths_mask;
3767 int tried_publickey, tried_agent;
3768 int tis_auth_refused, ccard_auth_refused;
3769 unsigned char session_id[16];
3771 void *publickey_blob;
3772 int publickey_bloblen;
3773 char *publickey_comment;
3774 int publickey_encrypted;
3775 prompts_t *cur_prompt;
3778 unsigned char request[5], *response, *p;
3788 struct RSAKey servkey, hostkey;
3790 crState(do_ssh1_login_state);
3797 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
3798 bombout(("Public key packet not received"));
3802 logevent("Received public keys");
3804 ptr = ssh_pkt_getdata(pktin, 8);
3806 bombout(("SSH-1 public key packet stopped before random cookie"));
3809 memcpy(cookie, ptr, 8);
3811 if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) ||
3812 !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) {
3813 bombout(("Failed to read SSH-1 public keys from public key packet"));
3818 * Log the host key fingerprint.
3822 logevent("Host key fingerprint is:");
3823 strcpy(logmsg, " ");
3824 s->hostkey.comment = NULL;
3825 rsa_fingerprint(logmsg + strlen(logmsg),
3826 sizeof(logmsg) - strlen(logmsg), &s->hostkey);
3830 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3831 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3832 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
3833 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
3834 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
3836 ssh->v1_local_protoflags =
3837 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3838 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
3841 MD5Update(&md5c, s->keystr2, s->hostkey.bytes);
3842 MD5Update(&md5c, s->keystr1, s->servkey.bytes);
3843 MD5Update(&md5c, cookie, 8);
3844 MD5Final(s->session_id, &md5c);
3846 for (i = 0; i < 32; i++)
3847 ssh->session_key[i] = random_byte();
3850 * Verify that the `bits' and `bytes' parameters match.
3852 if (s->hostkey.bits > s->hostkey.bytes * 8 ||
3853 s->servkey.bits > s->servkey.bytes * 8) {
3854 bombout(("SSH-1 public keys were badly formatted"));
3858 s->len = (s->hostkey.bytes > s->servkey.bytes ?
3859 s->hostkey.bytes : s->servkey.bytes);
3861 s->rsabuf = snewn(s->len, unsigned char);
3864 * Verify the host key.
3868 * First format the key into a string.
3870 int len = rsastr_len(&s->hostkey);
3871 char fingerprint[100];
3872 char *keystr = snewn(len, char);
3873 rsastr_fmt(keystr, &s->hostkey);
3874 rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey);
3876 /* First check against manually configured host keys. */
3877 s->dlgret = verify_ssh_manual_host_key(ssh, fingerprint, NULL, NULL);
3878 if (s->dlgret == 0) { /* did not match */
3879 bombout(("Host key did not appear in manually configured list"));
3882 } else if (s->dlgret < 0) { /* none configured; use standard handling */
3883 ssh_set_frozen(ssh, 1);
3884 s->dlgret = verify_ssh_host_key(ssh->frontend,
3885 ssh->savedhost, ssh->savedport,
3886 "rsa", keystr, fingerprint,
3887 ssh_dialog_callback, ssh);
3889 if (s->dlgret < 0) {
3893 bombout(("Unexpected data from server while waiting"
3894 " for user host key response"));
3897 } while (pktin || inlen > 0);
3898 s->dlgret = ssh->user_response;
3900 ssh_set_frozen(ssh, 0);
3902 if (s->dlgret == 0) {
3903 ssh_disconnect(ssh, "User aborted at host key verification",
3912 for (i = 0; i < 32; i++) {
3913 s->rsabuf[i] = ssh->session_key[i];
3915 s->rsabuf[i] ^= s->session_id[i];
3918 if (s->hostkey.bytes > s->servkey.bytes) {
3919 ret = rsaencrypt(s->rsabuf, 32, &s->servkey);
3921 ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey);
3923 ret = rsaencrypt(s->rsabuf, 32, &s->hostkey);
3925 ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey);
3928 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3932 logevent("Encrypted session key");
3935 int cipher_chosen = 0, warn = 0;
3936 char *cipher_string = NULL;
3938 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
3939 int next_cipher = conf_get_int_int(ssh->conf,
3940 CONF_ssh_cipherlist, i);
3941 if (next_cipher == CIPHER_WARN) {
3942 /* If/when we choose a cipher, warn about it */
3944 } else if (next_cipher == CIPHER_AES) {
3945 /* XXX Probably don't need to mention this. */
3946 logevent("AES not supported in SSH-1, skipping");
3948 switch (next_cipher) {
3949 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
3950 cipher_string = "3DES"; break;
3951 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
3952 cipher_string = "Blowfish"; break;
3953 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
3954 cipher_string = "single-DES"; break;
3956 if (s->supported_ciphers_mask & (1 << s->cipher_type))
3960 if (!cipher_chosen) {
3961 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
3962 bombout(("Server violates SSH-1 protocol by not "
3963 "supporting 3DES encryption"));
3965 /* shouldn't happen */
3966 bombout(("No supported ciphers found"));
3970 /* Warn about chosen cipher if necessary. */
3972 ssh_set_frozen(ssh, 1);
3973 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3974 ssh_dialog_callback, ssh);
3975 if (s->dlgret < 0) {
3979 bombout(("Unexpected data from server while waiting"
3980 " for user response"));
3983 } while (pktin || inlen > 0);
3984 s->dlgret = ssh->user_response;
3986 ssh_set_frozen(ssh, 0);
3987 if (s->dlgret == 0) {
3988 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3995 switch (s->cipher_type) {
3996 case SSH_CIPHER_3DES:
3997 logevent("Using 3DES encryption");
3999 case SSH_CIPHER_DES:
4000 logevent("Using single-DES encryption");
4002 case SSH_CIPHER_BLOWFISH:
4003 logevent("Using Blowfish encryption");
4007 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
4008 PKT_CHAR, s->cipher_type,
4009 PKT_DATA, cookie, 8,
4010 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
4011 PKT_DATA, s->rsabuf, s->len,
4012 PKT_INT, ssh->v1_local_protoflags, PKT_END);
4014 logevent("Trying to enable encryption...");
4018 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
4019 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
4021 ssh->v1_cipher_ctx = ssh->cipher->make_context();
4022 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
4023 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
4025 ssh->crcda_ctx = crcda_make_context();
4026 logevent("Installing CRC compensation attack detector");
4028 if (s->servkey.modulus) {
4029 sfree(s->servkey.modulus);
4030 s->servkey.modulus = NULL;
4032 if (s->servkey.exponent) {
4033 sfree(s->servkey.exponent);
4034 s->servkey.exponent = NULL;
4036 if (s->hostkey.modulus) {
4037 sfree(s->hostkey.modulus);
4038 s->hostkey.modulus = NULL;
4040 if (s->hostkey.exponent) {
4041 sfree(s->hostkey.exponent);
4042 s->hostkey.exponent = NULL;
4046 if (pktin->type != SSH1_SMSG_SUCCESS) {
4047 bombout(("Encryption not successfully enabled"));
4051 logevent("Successfully started encryption");
4053 fflush(stdout); /* FIXME eh? */
4055 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
4056 int ret; /* need not be kept over crReturn */
4057 s->cur_prompt = new_prompts(ssh->frontend);
4058 s->cur_prompt->to_server = TRUE;
4059 s->cur_prompt->name = dupstr("SSH login name");
4060 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
4061 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4064 crWaitUntil(!pktin);
4065 ret = get_userpass_input(s->cur_prompt, in, inlen);
4070 * Failed to get a username. Terminate.
4072 free_prompts(s->cur_prompt);
4073 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
4076 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
4077 free_prompts(s->cur_prompt);
4080 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
4082 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
4084 if (flags & FLAG_INTERACTIVE &&
4085 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
4086 c_write_str(ssh, userlog);
4087 c_write_str(ssh, "\r\n");
4095 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
4096 /* We must not attempt PK auth. Pretend we've already tried it. */
4097 s->tried_publickey = s->tried_agent = 1;
4099 s->tried_publickey = s->tried_agent = 0;
4101 s->tis_auth_refused = s->ccard_auth_refused = 0;
4103 * Load the public half of any configured keyfile for later use.
4105 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4106 if (!filename_is_null(s->keyfile)) {
4108 logeventf(ssh, "Reading private key file \"%.150s\"",
4109 filename_to_str(s->keyfile));
4110 keytype = key_type(s->keyfile);
4111 if (keytype == SSH_KEYTYPE_SSH1) {
4113 if (rsakey_pubblob(s->keyfile,
4114 &s->publickey_blob, &s->publickey_bloblen,
4115 &s->publickey_comment, &error)) {
4116 s->publickey_encrypted = rsakey_encrypted(s->keyfile,
4120 logeventf(ssh, "Unable to load private key (%s)", error);
4121 msgbuf = dupprintf("Unable to load private key file "
4122 "\"%.150s\" (%s)\r\n",
4123 filename_to_str(s->keyfile),
4125 c_write_str(ssh, msgbuf);
4127 s->publickey_blob = NULL;
4131 logeventf(ssh, "Unable to use this key file (%s)",
4132 key_type_to_str(keytype));
4133 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4135 filename_to_str(s->keyfile),
4136 key_type_to_str(keytype));
4137 c_write_str(ssh, msgbuf);
4139 s->publickey_blob = NULL;
4142 s->publickey_blob = NULL;
4144 while (pktin->type == SSH1_SMSG_FAILURE) {
4145 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
4147 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
4149 * Attempt RSA authentication using Pageant.
4155 logevent("Pageant is running. Requesting keys.");
4157 /* Request the keys held by the agent. */
4158 PUT_32BIT(s->request, 1);
4159 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
4160 if (!agent_query(s->request, 5, &r, &s->responselen,
4161 ssh_agent_callback, ssh)) {
4165 bombout(("Unexpected data from server while waiting"
4166 " for agent response"));
4169 } while (pktin || inlen > 0);
4170 r = ssh->agent_response;
4171 s->responselen = ssh->agent_response_len;
4173 s->response = (unsigned char *) r;
4174 if (s->response && s->responselen >= 5 &&
4175 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
4176 s->p = s->response + 5;
4177 s->nkeys = toint(GET_32BIT(s->p));
4179 logeventf(ssh, "Pageant reported negative key count %d",
4184 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
4185 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4186 unsigned char *pkblob = s->p;
4190 do { /* do while (0) to make breaking easy */
4191 n = ssh1_read_bignum
4192 (s->p, toint(s->responselen-(s->p-s->response)),
4197 n = ssh1_read_bignum
4198 (s->p, toint(s->responselen-(s->p-s->response)),
4203 if (s->responselen - (s->p-s->response) < 4)
4205 s->commentlen = toint(GET_32BIT(s->p));
4207 if (s->commentlen < 0 ||
4208 toint(s->responselen - (s->p-s->response)) <
4211 s->commentp = (char *)s->p;
4212 s->p += s->commentlen;
4216 logevent("Pageant key list packet was truncated");
4220 if (s->publickey_blob) {
4221 if (!memcmp(pkblob, s->publickey_blob,
4222 s->publickey_bloblen)) {
4223 logeventf(ssh, "Pageant key #%d matches "
4224 "configured key file", s->keyi);
4225 s->tried_publickey = 1;
4227 /* Skip non-configured key */
4230 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
4231 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4232 PKT_BIGNUM, s->key.modulus, PKT_END);
4234 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4235 logevent("Key refused");
4238 logevent("Received RSA challenge");
4239 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4240 bombout(("Server's RSA challenge was badly formatted"));
4245 char *agentreq, *q, *ret;
4248 len = 1 + 4; /* message type, bit count */
4249 len += ssh1_bignum_length(s->key.exponent);
4250 len += ssh1_bignum_length(s->key.modulus);
4251 len += ssh1_bignum_length(s->challenge);
4252 len += 16; /* session id */
4253 len += 4; /* response format */
4254 agentreq = snewn(4 + len, char);
4255 PUT_32BIT(agentreq, len);
4257 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
4258 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
4260 q += ssh1_write_bignum(q, s->key.exponent);
4261 q += ssh1_write_bignum(q, s->key.modulus);
4262 q += ssh1_write_bignum(q, s->challenge);
4263 memcpy(q, s->session_id, 16);
4265 PUT_32BIT(q, 1); /* response format */
4266 if (!agent_query(agentreq, len + 4, &vret, &retlen,
4267 ssh_agent_callback, ssh)) {
4272 bombout(("Unexpected data from server"
4273 " while waiting for agent"
4277 } while (pktin || inlen > 0);
4278 vret = ssh->agent_response;
4279 retlen = ssh->agent_response_len;
4284 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
4285 logevent("Sending Pageant's response");
4286 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4287 PKT_DATA, ret + 5, 16,
4291 if (pktin->type == SSH1_SMSG_SUCCESS) {
4293 ("Pageant's response accepted");
4294 if (flags & FLAG_VERBOSE) {
4295 c_write_str(ssh, "Authenticated using"
4297 c_write(ssh, s->commentp,
4299 c_write_str(ssh, "\" from agent\r\n");
4304 ("Pageant's response not accepted");
4307 ("Pageant failed to answer challenge");
4311 logevent("No reply received from Pageant");
4314 freebn(s->key.exponent);
4315 freebn(s->key.modulus);
4316 freebn(s->challenge);
4321 if (s->publickey_blob && !s->tried_publickey)
4322 logevent("Configured key file not in Pageant");
4324 logevent("Failed to get reply from Pageant");
4329 if (s->publickey_blob && !s->tried_publickey) {
4331 * Try public key authentication with the specified
4334 int got_passphrase; /* need not be kept over crReturn */
4335 if (flags & FLAG_VERBOSE)
4336 c_write_str(ssh, "Trying public key authentication.\r\n");
4337 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4338 logeventf(ssh, "Trying public key \"%s\"",
4339 filename_to_str(s->keyfile));
4340 s->tried_publickey = 1;
4341 got_passphrase = FALSE;
4342 while (!got_passphrase) {
4344 * Get a passphrase, if necessary.
4346 char *passphrase = NULL; /* only written after crReturn */
4348 if (!s->publickey_encrypted) {
4349 if (flags & FLAG_VERBOSE)
4350 c_write_str(ssh, "No passphrase required.\r\n");
4353 int ret; /* need not be kept over crReturn */
4354 s->cur_prompt = new_prompts(ssh->frontend);
4355 s->cur_prompt->to_server = FALSE;
4356 s->cur_prompt->name = dupstr("SSH key passphrase");
4357 add_prompt(s->cur_prompt,
4358 dupprintf("Passphrase for key \"%.100s\": ",
4359 s->publickey_comment), FALSE);
4360 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4363 crWaitUntil(!pktin);
4364 ret = get_userpass_input(s->cur_prompt, in, inlen);
4368 /* Failed to get a passphrase. Terminate. */
4369 free_prompts(s->cur_prompt);
4370 ssh_disconnect(ssh, NULL, "Unable to authenticate",
4374 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
4375 free_prompts(s->cur_prompt);
4378 * Try decrypting key with passphrase.
4380 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4381 ret = loadrsakey(s->keyfile, &s->key, passphrase,
4384 smemclr(passphrase, strlen(passphrase));
4388 /* Correct passphrase. */
4389 got_passphrase = TRUE;
4390 } else if (ret == 0) {
4391 c_write_str(ssh, "Couldn't load private key from ");
4392 c_write_str(ssh, filename_to_str(s->keyfile));
4393 c_write_str(ssh, " (");
4394 c_write_str(ssh, error);
4395 c_write_str(ssh, ").\r\n");
4396 got_passphrase = FALSE;
4397 break; /* go and try something else */
4398 } else if (ret == -1) {
4399 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
4400 got_passphrase = FALSE;
4403 assert(0 && "unexpected return from loadrsakey()");
4404 got_passphrase = FALSE; /* placate optimisers */
4408 if (got_passphrase) {
4411 * Send a public key attempt.
4413 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4414 PKT_BIGNUM, s->key.modulus, PKT_END);
4417 if (pktin->type == SSH1_SMSG_FAILURE) {
4418 c_write_str(ssh, "Server refused our public key.\r\n");
4419 continue; /* go and try something else */
4421 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4422 bombout(("Bizarre response to offer of public key"));
4428 unsigned char buffer[32];
4429 Bignum challenge, response;
4431 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4432 bombout(("Server's RSA challenge was badly formatted"));
4435 response = rsadecrypt(challenge, &s->key);
4436 freebn(s->key.private_exponent);/* burn the evidence */
4438 for (i = 0; i < 32; i++) {
4439 buffer[i] = bignum_byte(response, 31 - i);
4443 MD5Update(&md5c, buffer, 32);
4444 MD5Update(&md5c, s->session_id, 16);
4445 MD5Final(buffer, &md5c);
4447 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4448 PKT_DATA, buffer, 16, PKT_END);
4455 if (pktin->type == SSH1_SMSG_FAILURE) {
4456 if (flags & FLAG_VERBOSE)
4457 c_write_str(ssh, "Failed to authenticate with"
4458 " our public key.\r\n");
4459 continue; /* go and try something else */
4460 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4461 bombout(("Bizarre response to RSA authentication response"));
4465 break; /* we're through! */
4471 * Otherwise, try various forms of password-like authentication.
4473 s->cur_prompt = new_prompts(ssh->frontend);
4475 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4476 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
4477 !s->tis_auth_refused) {
4478 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
4479 logevent("Requested TIS authentication");
4480 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
4482 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
4483 logevent("TIS authentication declined");
4484 if (flags & FLAG_INTERACTIVE)
4485 c_write_str(ssh, "TIS authentication refused.\r\n");
4486 s->tis_auth_refused = 1;
4491 char *instr_suf, *prompt;
4493 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4495 bombout(("TIS challenge packet was badly formed"));
4498 logevent("Received TIS challenge");
4499 s->cur_prompt->to_server = TRUE;
4500 s->cur_prompt->name = dupstr("SSH TIS authentication");
4501 /* Prompt heuristic comes from OpenSSH */
4502 if (memchr(challenge, '\n', challengelen)) {
4503 instr_suf = dupstr("");
4504 prompt = dupprintf("%.*s", challengelen, challenge);
4506 instr_suf = dupprintf("%.*s", challengelen, challenge);
4507 prompt = dupstr("Response: ");
4509 s->cur_prompt->instruction =
4510 dupprintf("Using TIS authentication.%s%s",
4511 (*instr_suf) ? "\n" : "",
4513 s->cur_prompt->instr_reqd = TRUE;
4514 add_prompt(s->cur_prompt, prompt, FALSE);
4518 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4519 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
4520 !s->ccard_auth_refused) {
4521 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
4522 logevent("Requested CryptoCard authentication");
4523 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
4525 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
4526 logevent("CryptoCard authentication declined");
4527 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4528 s->ccard_auth_refused = 1;
4533 char *instr_suf, *prompt;
4535 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4537 bombout(("CryptoCard challenge packet was badly formed"));
4540 logevent("Received CryptoCard challenge");
4541 s->cur_prompt->to_server = TRUE;
4542 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4543 s->cur_prompt->name_reqd = FALSE;
4544 /* Prompt heuristic comes from OpenSSH */
4545 if (memchr(challenge, '\n', challengelen)) {
4546 instr_suf = dupstr("");
4547 prompt = dupprintf("%.*s", challengelen, challenge);
4549 instr_suf = dupprintf("%.*s", challengelen, challenge);
4550 prompt = dupstr("Response: ");
4552 s->cur_prompt->instruction =
4553 dupprintf("Using CryptoCard authentication.%s%s",
4554 (*instr_suf) ? "\n" : "",
4556 s->cur_prompt->instr_reqd = TRUE;
4557 add_prompt(s->cur_prompt, prompt, FALSE);
4561 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4562 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4563 bombout(("No supported authentication methods available"));
4566 s->cur_prompt->to_server = TRUE;
4567 s->cur_prompt->name = dupstr("SSH password");
4568 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4569 ssh->username, ssh->savedhost),
4574 * Show password prompt, having first obtained it via a TIS
4575 * or CryptoCard exchange if we're doing TIS or CryptoCard
4579 int ret; /* need not be kept over crReturn */
4580 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4583 crWaitUntil(!pktin);
4584 ret = get_userpass_input(s->cur_prompt, in, inlen);
4589 * Failed to get a password (for example
4590 * because one was supplied on the command line
4591 * which has already failed to work). Terminate.
4593 free_prompts(s->cur_prompt);
4594 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4599 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4601 * Defence against traffic analysis: we send a
4602 * whole bunch of packets containing strings of
4603 * different lengths. One of these strings is the
4604 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4605 * The others are all random data in
4606 * SSH1_MSG_IGNORE packets. This way a passive
4607 * listener can't tell which is the password, and
4608 * hence can't deduce the password length.
4610 * Anybody with a password length greater than 16
4611 * bytes is going to have enough entropy in their
4612 * password that a listener won't find it _that_
4613 * much help to know how long it is. So what we'll
4616 * - if password length < 16, we send 15 packets
4617 * containing string lengths 1 through 15
4619 * - otherwise, we let N be the nearest multiple
4620 * of 8 below the password length, and send 8
4621 * packets containing string lengths N through
4622 * N+7. This won't obscure the order of
4623 * magnitude of the password length, but it will
4624 * introduce a bit of extra uncertainty.
4626 * A few servers can't deal with SSH1_MSG_IGNORE, at
4627 * least in this context. For these servers, we need
4628 * an alternative defence. We make use of the fact
4629 * that the password is interpreted as a C string:
4630 * so we can append a NUL, then some random data.
4632 * A few servers can deal with neither SSH1_MSG_IGNORE
4633 * here _nor_ a padded password string.
4634 * For these servers we are left with no defences
4635 * against password length sniffing.
4637 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4638 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4640 * The server can deal with SSH1_MSG_IGNORE, so
4641 * we can use the primary defence.
4643 int bottom, top, pwlen, i;
4646 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4648 bottom = 0; /* zero length passwords are OK! :-) */
4651 bottom = pwlen & ~7;
4655 assert(pwlen >= bottom && pwlen <= top);
4657 randomstr = snewn(top + 1, char);
4659 for (i = bottom; i <= top; i++) {
4661 defer_packet(ssh, s->pwpkt_type,
4662 PKT_STR,s->cur_prompt->prompts[0]->result,
4665 for (j = 0; j < i; j++) {
4667 randomstr[j] = random_byte();
4668 } while (randomstr[j] == '\0');
4670 randomstr[i] = '\0';
4671 defer_packet(ssh, SSH1_MSG_IGNORE,
4672 PKT_STR, randomstr, PKT_END);
4675 logevent("Sending password with camouflage packets");
4676 ssh_pkt_defersend(ssh);
4679 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4681 * The server can't deal with SSH1_MSG_IGNORE
4682 * but can deal with padded passwords, so we
4683 * can use the secondary defence.
4689 len = strlen(s->cur_prompt->prompts[0]->result);
4690 if (len < sizeof(string)) {
4692 strcpy(string, s->cur_prompt->prompts[0]->result);
4693 len++; /* cover the zero byte */
4694 while (len < sizeof(string)) {
4695 string[len++] = (char) random_byte();
4698 ss = s->cur_prompt->prompts[0]->result;
4700 logevent("Sending length-padded password");
4701 send_packet(ssh, s->pwpkt_type,
4702 PKT_INT, len, PKT_DATA, ss, len,
4706 * The server is believed unable to cope with
4707 * any of our password camouflage methods.
4710 len = strlen(s->cur_prompt->prompts[0]->result);
4711 logevent("Sending unpadded password");
4712 send_packet(ssh, s->pwpkt_type,
4714 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4718 send_packet(ssh, s->pwpkt_type,
4719 PKT_STR, s->cur_prompt->prompts[0]->result,
4722 logevent("Sent password");
4723 free_prompts(s->cur_prompt);
4725 if (pktin->type == SSH1_SMSG_FAILURE) {
4726 if (flags & FLAG_VERBOSE)
4727 c_write_str(ssh, "Access denied\r\n");
4728 logevent("Authentication refused");
4729 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4730 bombout(("Strange packet received, type %d", pktin->type));
4736 if (s->publickey_blob) {
4737 sfree(s->publickey_blob);
4738 sfree(s->publickey_comment);
4741 logevent("Authentication successful");
4746 static void ssh_channel_try_eof(struct ssh_channel *c)
4749 assert(c->pending_eof); /* precondition for calling us */
4751 return; /* can't close: not even opened yet */
4752 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4753 return; /* can't send EOF: pending outgoing data */
4755 c->pending_eof = FALSE; /* we're about to send it */
4756 if (ssh->version == 1) {
4757 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4759 c->closes |= CLOSES_SENT_EOF;
4761 struct Packet *pktout;
4762 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4763 ssh2_pkt_adduint32(pktout, c->remoteid);
4764 ssh2_pkt_send(ssh, pktout);
4765 c->closes |= CLOSES_SENT_EOF;
4766 ssh2_channel_check_close(c);
4770 Conf *sshfwd_get_conf(struct ssh_channel *c)
4776 void sshfwd_write_eof(struct ssh_channel *c)
4780 if (ssh->state == SSH_STATE_CLOSED)
4783 if (c->closes & CLOSES_SENT_EOF)
4786 c->pending_eof = TRUE;
4787 ssh_channel_try_eof(c);
4790 void sshfwd_unclean_close(struct ssh_channel *c, const char *err)
4794 if (ssh->state == SSH_STATE_CLOSED)
4799 x11_close(c->u.x11.xconn);
4800 logeventf(ssh, "Forwarded X11 connection terminated due to local "
4804 case CHAN_SOCKDATA_DORMANT:
4805 pfd_close(c->u.pfd.pf);
4806 logeventf(ssh, "Forwarded port closed due to local error: %s", err);
4809 c->type = CHAN_ZOMBIE;
4810 c->pending_eof = FALSE; /* this will confuse a zombie channel */
4812 ssh2_channel_check_close(c);
4815 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
4819 if (ssh->state == SSH_STATE_CLOSED)
4822 if (ssh->version == 1) {
4823 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
4824 PKT_INT, c->remoteid,
4825 PKT_INT, len, PKT_DATA, buf, len,
4828 * In SSH-1 we can return 0 here - implying that forwarded
4829 * connections are never individually throttled - because
4830 * the only circumstance that can cause throttling will be
4831 * the whole SSH connection backing up, in which case
4832 * _everything_ will be throttled as a whole.
4836 ssh2_add_channel_data(c, buf, len);
4837 return ssh2_try_send(c);
4841 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4846 if (ssh->state == SSH_STATE_CLOSED)
4849 if (ssh->version == 1) {
4850 buflimit = SSH1_BUFFER_LIMIT;
4852 buflimit = c->v.v2.locmaxwin;
4853 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
4855 if (c->throttling_conn && bufsize <= buflimit) {
4856 c->throttling_conn = 0;
4857 ssh_throttle_conn(ssh, -1);
4861 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
4863 struct queued_handler *qh = ssh->qhead;
4867 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
4870 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
4871 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
4874 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
4875 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
4879 ssh->qhead = qh->next;
4881 if (ssh->qhead->msg1 > 0) {
4882 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4883 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
4885 if (ssh->qhead->msg2 > 0) {
4886 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4887 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
4890 ssh->qhead = ssh->qtail = NULL;
4893 qh->handler(ssh, pktin, qh->ctx);
4898 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
4899 chandler_fn_t handler, void *ctx)
4901 struct queued_handler *qh;
4903 qh = snew(struct queued_handler);
4906 qh->handler = handler;
4910 if (ssh->qtail == NULL) {
4914 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4915 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
4918 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4919 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
4922 ssh->qtail->next = qh;
4927 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
4929 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
4931 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
4932 SSH2_MSG_REQUEST_SUCCESS)) {
4933 logeventf(ssh, "Remote port forwarding from %s enabled",
4936 logeventf(ssh, "Remote port forwarding from %s refused",
4939 rpf = del234(ssh->rportfwds, pf);
4941 pf->pfrec->remote = NULL;
4946 int ssh_alloc_sharing_rportfwd(Ssh ssh, const char *shost, int sport,
4949 struct ssh_rportfwd *pf = snew(struct ssh_rportfwd);
4952 pf->share_ctx = share_ctx;
4953 pf->shost = dupstr(shost);
4955 pf->sportdesc = NULL;
4956 if (!ssh->rportfwds) {
4957 assert(ssh->version == 2);
4958 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4960 if (add234(ssh->rportfwds, pf) != pf) {
4968 static void ssh_sharing_global_request_response(Ssh ssh, struct Packet *pktin,
4971 share_got_pkt_from_server(ctx, pktin->type,
4972 pktin->body, pktin->length);
4975 void ssh_sharing_queue_global_request(Ssh ssh, void *share_ctx)
4977 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, SSH2_MSG_REQUEST_FAILURE,
4978 ssh_sharing_global_request_response, share_ctx);
4981 static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
4983 struct ssh_portfwd *epf;
4987 if (!ssh->portfwds) {
4988 ssh->portfwds = newtree234(ssh_portcmp);
4991 * Go through the existing port forwardings and tag them
4992 * with status==DESTROY. Any that we want to keep will be
4993 * re-enabled (status==KEEP) as we go through the
4994 * configuration and find out which bits are the same as
4997 struct ssh_portfwd *epf;
4999 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5000 epf->status = DESTROY;
5003 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
5005 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
5006 char *kp, *kp2, *vp, *vp2;
5007 char address_family, type;
5008 int sport,dport,sserv,dserv;
5009 char *sports, *dports, *saddr, *host;
5013 address_family = 'A';
5015 if (*kp == 'A' || *kp == '4' || *kp == '6')
5016 address_family = *kp++;
5017 if (*kp == 'L' || *kp == 'R')
5020 if ((kp2 = host_strchr(kp, ':')) != NULL) {
5022 * There's a colon in the middle of the source port
5023 * string, which means that the part before it is
5024 * actually a source address.
5026 char *saddr_tmp = dupprintf("%.*s", (int)(kp2 - kp), kp);
5027 saddr = host_strduptrim(saddr_tmp);
5034 sport = atoi(sports);
5038 sport = net_service_lookup(sports);
5040 logeventf(ssh, "Service lookup failed for source"
5041 " port \"%s\"", sports);
5045 if (type == 'L' && !strcmp(val, "D")) {
5046 /* dynamic forwarding */
5053 /* ordinary forwarding */
5055 vp2 = vp + host_strcspn(vp, ":");
5056 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
5060 dport = atoi(dports);
5064 dport = net_service_lookup(dports);
5066 logeventf(ssh, "Service lookup failed for destination"
5067 " port \"%s\"", dports);
5072 if (sport && dport) {
5073 /* Set up a description of the source port. */
5074 struct ssh_portfwd *pfrec, *epfrec;
5076 pfrec = snew(struct ssh_portfwd);
5078 pfrec->saddr = saddr;
5079 pfrec->sserv = sserv ? dupstr(sports) : NULL;
5080 pfrec->sport = sport;
5081 pfrec->daddr = host;
5082 pfrec->dserv = dserv ? dupstr(dports) : NULL;
5083 pfrec->dport = dport;
5084 pfrec->local = NULL;
5085 pfrec->remote = NULL;
5086 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
5087 address_family == '6' ? ADDRTYPE_IPV6 :
5090 epfrec = add234(ssh->portfwds, pfrec);
5091 if (epfrec != pfrec) {
5092 if (epfrec->status == DESTROY) {
5094 * We already have a port forwarding up and running
5095 * with precisely these parameters. Hence, no need
5096 * to do anything; simply re-tag the existing one
5099 epfrec->status = KEEP;
5102 * Anything else indicates that there was a duplicate
5103 * in our input, which we'll silently ignore.
5105 free_portfwd(pfrec);
5107 pfrec->status = CREATE;
5116 * Now go through and destroy any port forwardings which were
5119 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5120 if (epf->status == DESTROY) {
5123 message = dupprintf("%s port forwarding from %s%s%d",
5124 epf->type == 'L' ? "local" :
5125 epf->type == 'R' ? "remote" : "dynamic",
5126 epf->saddr ? epf->saddr : "",
5127 epf->saddr ? ":" : "",
5130 if (epf->type != 'D') {
5131 char *msg2 = dupprintf("%s to %s:%d", message,
5132 epf->daddr, epf->dport);
5137 logeventf(ssh, "Cancelling %s", message);
5140 /* epf->remote or epf->local may be NULL if setting up a
5141 * forwarding failed. */
5143 struct ssh_rportfwd *rpf = epf->remote;
5144 struct Packet *pktout;
5147 * Cancel the port forwarding at the server
5150 if (ssh->version == 1) {
5152 * We cannot cancel listening ports on the
5153 * server side in SSH-1! There's no message
5154 * to support it. Instead, we simply remove
5155 * the rportfwd record from the local end
5156 * so that any connections the server tries
5157 * to make on it are rejected.
5160 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5161 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
5162 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
5164 ssh2_pkt_addstring(pktout, epf->saddr);
5165 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5166 /* XXX: rport_acceptall may not represent
5167 * what was used to open the original connection,
5168 * since it's reconfigurable. */
5169 ssh2_pkt_addstring(pktout, "");
5171 ssh2_pkt_addstring(pktout, "localhost");
5173 ssh2_pkt_adduint32(pktout, epf->sport);
5174 ssh2_pkt_send(ssh, pktout);
5177 del234(ssh->rportfwds, rpf);
5179 } else if (epf->local) {
5180 pfl_terminate(epf->local);
5183 delpos234(ssh->portfwds, i);
5185 i--; /* so we don't skip one in the list */
5189 * And finally, set up any new port forwardings (status==CREATE).
5191 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5192 if (epf->status == CREATE) {
5193 char *sportdesc, *dportdesc;
5194 sportdesc = dupprintf("%s%s%s%s%d%s",
5195 epf->saddr ? epf->saddr : "",
5196 epf->saddr ? ":" : "",
5197 epf->sserv ? epf->sserv : "",
5198 epf->sserv ? "(" : "",
5200 epf->sserv ? ")" : "");
5201 if (epf->type == 'D') {
5204 dportdesc = dupprintf("%s:%s%s%d%s",
5206 epf->dserv ? epf->dserv : "",
5207 epf->dserv ? "(" : "",
5209 epf->dserv ? ")" : "");
5212 if (epf->type == 'L') {
5213 char *err = pfl_listen(epf->daddr, epf->dport,
5214 epf->saddr, epf->sport,
5215 ssh, conf, &epf->local,
5216 epf->addressfamily);
5218 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
5219 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5220 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5221 sportdesc, dportdesc,
5222 err ? " failed: " : "", err ? err : "");
5225 } else if (epf->type == 'D') {
5226 char *err = pfl_listen(NULL, -1, epf->saddr, epf->sport,
5227 ssh, conf, &epf->local,
5228 epf->addressfamily);
5230 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
5231 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5232 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5234 err ? " failed: " : "", err ? err : "");
5239 struct ssh_rportfwd *pf;
5242 * Ensure the remote port forwardings tree exists.
5244 if (!ssh->rportfwds) {
5245 if (ssh->version == 1)
5246 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
5248 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5251 pf = snew(struct ssh_rportfwd);
5252 pf->share_ctx = NULL;
5253 pf->dhost = dupstr(epf->daddr);
5254 pf->dport = epf->dport;
5256 pf->shost = dupstr(epf->saddr);
5257 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5258 pf->shost = dupstr("");
5260 pf->shost = dupstr("localhost");
5262 pf->sport = epf->sport;
5263 if (add234(ssh->rportfwds, pf) != pf) {
5264 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
5265 epf->daddr, epf->dport);
5268 logeventf(ssh, "Requesting remote port %s"
5269 " forward to %s", sportdesc, dportdesc);
5271 pf->sportdesc = sportdesc;
5276 if (ssh->version == 1) {
5277 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
5278 PKT_INT, epf->sport,
5279 PKT_STR, epf->daddr,
5280 PKT_INT, epf->dport,
5282 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
5284 ssh_rportfwd_succfail, pf);
5286 struct Packet *pktout;
5287 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5288 ssh2_pkt_addstring(pktout, "tcpip-forward");
5289 ssh2_pkt_addbool(pktout, 1);/* want reply */
5290 ssh2_pkt_addstring(pktout, pf->shost);
5291 ssh2_pkt_adduint32(pktout, pf->sport);
5292 ssh2_pkt_send(ssh, pktout);
5294 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
5295 SSH2_MSG_REQUEST_FAILURE,
5296 ssh_rportfwd_succfail, pf);
5305 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
5308 int stringlen, bufsize;
5310 ssh_pkt_getstring(pktin, &string, &stringlen);
5311 if (string == NULL) {
5312 bombout(("Incoming terminal data packet was badly formed"));
5316 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
5318 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
5319 ssh->v1_stdout_throttling = 1;
5320 ssh_throttle_conn(ssh, +1);
5324 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
5326 /* Remote side is trying to open a channel to talk to our
5327 * X-Server. Give them back a local channel number. */
5328 struct ssh_channel *c;
5329 int remoteid = ssh_pkt_getuint32(pktin);
5331 logevent("Received X11 connect request");
5332 /* Refuse if X11 forwarding is disabled. */
5333 if (!ssh->X11_fwd_enabled) {
5334 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5335 PKT_INT, remoteid, PKT_END);
5336 logevent("Rejected X11 connect request");
5338 c = snew(struct ssh_channel);
5341 c->u.x11.xconn = x11_init(ssh->x11authtree, c, NULL, -1);
5342 c->remoteid = remoteid;
5343 c->halfopen = FALSE;
5344 c->localid = alloc_channel_id(ssh);
5346 c->pending_eof = FALSE;
5347 c->throttling_conn = 0;
5348 c->type = CHAN_X11; /* identify channel type */
5349 add234(ssh->channels, c);
5350 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5351 PKT_INT, c->remoteid, PKT_INT,
5352 c->localid, PKT_END);
5353 logevent("Opened X11 forward channel");
5357 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
5359 /* Remote side is trying to open a channel to talk to our
5360 * agent. Give them back a local channel number. */
5361 struct ssh_channel *c;
5362 int remoteid = ssh_pkt_getuint32(pktin);
5364 /* Refuse if agent forwarding is disabled. */
5365 if (!ssh->agentfwd_enabled) {
5366 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5367 PKT_INT, remoteid, PKT_END);
5369 c = snew(struct ssh_channel);
5371 c->remoteid = remoteid;
5372 c->halfopen = FALSE;
5373 c->localid = alloc_channel_id(ssh);
5375 c->pending_eof = FALSE;
5376 c->throttling_conn = 0;
5377 c->type = CHAN_AGENT; /* identify channel type */
5378 c->u.a.lensofar = 0;
5379 c->u.a.message = NULL;
5380 c->u.a.outstanding_requests = 0;
5381 add234(ssh->channels, c);
5382 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5383 PKT_INT, c->remoteid, PKT_INT, c->localid,
5388 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
5390 /* Remote side is trying to open a channel to talk to a
5391 * forwarded port. Give them back a local channel number. */
5392 struct ssh_rportfwd pf, *pfp;
5398 remoteid = ssh_pkt_getuint32(pktin);
5399 ssh_pkt_getstring(pktin, &host, &hostsize);
5400 port = ssh_pkt_getuint32(pktin);
5402 pf.dhost = dupprintf("%.*s", hostsize, host);
5404 pfp = find234(ssh->rportfwds, &pf, NULL);
5407 logeventf(ssh, "Rejected remote port open request for %s:%d",
5409 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5410 PKT_INT, remoteid, PKT_END);
5412 struct ssh_channel *c = snew(struct ssh_channel);
5415 logeventf(ssh, "Received remote port open request for %s:%d",
5417 err = pfd_connect(&c->u.pfd.pf, pf.dhost, port,
5418 c, ssh->conf, pfp->pfrec->addressfamily);
5420 logeventf(ssh, "Port open failed: %s", err);
5423 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5424 PKT_INT, remoteid, PKT_END);
5426 c->remoteid = remoteid;
5427 c->halfopen = FALSE;
5428 c->localid = alloc_channel_id(ssh);
5430 c->pending_eof = FALSE;
5431 c->throttling_conn = 0;
5432 c->type = CHAN_SOCKDATA; /* identify channel type */
5433 add234(ssh->channels, c);
5434 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5435 PKT_INT, c->remoteid, PKT_INT,
5436 c->localid, PKT_END);
5437 logevent("Forwarded port opened successfully");
5444 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5446 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5447 unsigned int localid = ssh_pkt_getuint32(pktin);
5448 struct ssh_channel *c;
5450 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5451 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5452 c->remoteid = localid;
5453 c->halfopen = FALSE;
5454 c->type = CHAN_SOCKDATA;
5455 c->throttling_conn = 0;
5456 pfd_confirm(c->u.pfd.pf);
5459 if (c && c->pending_eof) {
5461 * We have a pending close on this channel,
5462 * which we decided on before the server acked
5463 * the channel open. So now we know the
5464 * remoteid, we can close it again.
5466 ssh_channel_try_eof(c);
5470 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5472 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5473 struct ssh_channel *c;
5475 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5476 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5477 logevent("Forwarded connection refused by server");
5478 pfd_close(c->u.pfd.pf);
5479 del234(ssh->channels, c);
5484 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
5486 /* Remote side closes a channel. */
5487 unsigned i = ssh_pkt_getuint32(pktin);
5488 struct ssh_channel *c;
5489 c = find234(ssh->channels, &i, ssh_channelfind);
5490 if (c && !c->halfopen) {
5492 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
5493 !(c->closes & CLOSES_RCVD_EOF)) {
5495 * Received CHANNEL_CLOSE, which we translate into
5498 int send_close = FALSE;
5500 c->closes |= CLOSES_RCVD_EOF;
5505 x11_send_eof(c->u.x11.xconn);
5511 pfd_send_eof(c->u.pfd.pf);
5520 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
5521 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
5523 c->closes |= CLOSES_SENT_EOF;
5527 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
5528 !(c->closes & CLOSES_RCVD_CLOSE)) {
5530 if (!(c->closes & CLOSES_SENT_EOF)) {
5531 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
5532 " for which we never sent CHANNEL_CLOSE\n", i));
5535 c->closes |= CLOSES_RCVD_CLOSE;
5538 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
5539 !(c->closes & CLOSES_SENT_CLOSE)) {
5540 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
5541 PKT_INT, c->remoteid, PKT_END);
5542 c->closes |= CLOSES_SENT_CLOSE;
5545 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5546 ssh_channel_destroy(c);
5548 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5549 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
5550 "_CONFIRMATION", c ? "half-open" : "nonexistent",
5555 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5557 /* Data sent down one of our channels. */
5558 int i = ssh_pkt_getuint32(pktin);
5561 struct ssh_channel *c;
5563 ssh_pkt_getstring(pktin, &p, &len);
5565 c = find234(ssh->channels, &i, ssh_channelfind);
5570 bufsize = x11_send(c->u.x11.xconn, p, len);
5573 bufsize = pfd_send(c->u.pfd.pf, p, len);
5576 /* Data for an agent message. Buffer it. */
5578 if (c->u.a.lensofar < 4) {
5579 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
5580 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
5584 c->u.a.lensofar += l;
5586 if (c->u.a.lensofar == 4) {
5588 4 + GET_32BIT(c->u.a.msglen);
5589 c->u.a.message = snewn(c->u.a.totallen,
5591 memcpy(c->u.a.message, c->u.a.msglen, 4);
5593 if (c->u.a.lensofar >= 4 && len > 0) {
5595 min(c->u.a.totallen - c->u.a.lensofar,
5597 memcpy(c->u.a.message + c->u.a.lensofar, p,
5601 c->u.a.lensofar += l;
5603 if (c->u.a.lensofar == c->u.a.totallen) {
5606 c->u.a.outstanding_requests++;
5607 if (agent_query(c->u.a.message,
5610 ssh_agentf_callback, c))
5611 ssh_agentf_callback(c, reply, replylen);
5612 sfree(c->u.a.message);
5613 c->u.a.lensofar = 0;
5616 bufsize = 0; /* agent channels never back up */
5619 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5620 c->throttling_conn = 1;
5621 ssh_throttle_conn(ssh, +1);
5626 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5628 ssh->exitcode = ssh_pkt_getuint32(pktin);
5629 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5630 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5632 * In case `helpful' firewalls or proxies tack
5633 * extra human-readable text on the end of the
5634 * session which we might mistake for another
5635 * encrypted packet, we close the session once
5636 * we've sent EXIT_CONFIRMATION.
5638 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5641 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5642 static void ssh1_send_ttymode(void *data, char *mode, char *val)
5644 struct Packet *pktout = (struct Packet *)data;
5646 unsigned int arg = 0;
5647 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5648 if (i == lenof(ssh_ttymodes)) return;
5649 switch (ssh_ttymodes[i].type) {
5651 arg = ssh_tty_parse_specchar(val);
5654 arg = ssh_tty_parse_boolean(val);
5657 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5658 ssh2_pkt_addbyte(pktout, arg);
5661 int ssh_agent_forwarding_permitted(Ssh ssh)
5663 return conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists();
5666 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
5667 struct Packet *pktin)
5669 crBegin(ssh->do_ssh1_connection_crstate);
5671 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5672 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5673 ssh1_smsg_stdout_stderr_data;
5675 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5676 ssh1_msg_channel_open_confirmation;
5677 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5678 ssh1_msg_channel_open_failure;
5679 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5680 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5681 ssh1_msg_channel_close;
5682 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5683 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5685 if (ssh_agent_forwarding_permitted(ssh)) {
5686 logevent("Requesting agent forwarding");
5687 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5691 if (pktin->type != SSH1_SMSG_SUCCESS
5692 && pktin->type != SSH1_SMSG_FAILURE) {
5693 bombout(("Protocol confusion"));
5695 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5696 logevent("Agent forwarding refused");
5698 logevent("Agent forwarding enabled");
5699 ssh->agentfwd_enabled = TRUE;
5700 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5704 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
5706 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5708 if (!ssh->x11disp) {
5709 /* FIXME: return an error message from x11_setup_display */
5710 logevent("X11 forwarding not enabled: unable to"
5711 " initialise X display");
5713 ssh->x11auth = x11_invent_fake_auth
5714 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
5715 ssh->x11auth->disp = ssh->x11disp;
5717 logevent("Requesting X11 forwarding");
5718 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5719 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5720 PKT_STR, ssh->x11auth->protoname,
5721 PKT_STR, ssh->x11auth->datastring,
5722 PKT_INT, ssh->x11disp->screennum,
5725 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5726 PKT_STR, ssh->x11auth->protoname,
5727 PKT_STR, ssh->x11auth->datastring,
5733 if (pktin->type != SSH1_SMSG_SUCCESS
5734 && pktin->type != SSH1_SMSG_FAILURE) {
5735 bombout(("Protocol confusion"));
5737 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5738 logevent("X11 forwarding refused");
5740 logevent("X11 forwarding enabled");
5741 ssh->X11_fwd_enabled = TRUE;
5742 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5747 ssh_setup_portfwd(ssh, ssh->conf);
5748 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5750 if (!conf_get_int(ssh->conf, CONF_nopty)) {
5752 /* Unpick the terminal-speed string. */
5753 /* XXX perhaps we should allow no speeds to be sent. */
5754 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5755 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
5756 /* Send the pty request. */
5757 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5758 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
5759 ssh_pkt_adduint32(pkt, ssh->term_height);
5760 ssh_pkt_adduint32(pkt, ssh->term_width);
5761 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5762 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5763 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
5764 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5765 ssh_pkt_adduint32(pkt, ssh->ispeed);
5766 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5767 ssh_pkt_adduint32(pkt, ssh->ospeed);
5768 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5770 ssh->state = SSH_STATE_INTERMED;
5774 if (pktin->type != SSH1_SMSG_SUCCESS
5775 && pktin->type != SSH1_SMSG_FAILURE) {
5776 bombout(("Protocol confusion"));
5778 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5779 c_write_str(ssh, "Server refused to allocate pty\r\n");
5780 ssh->editing = ssh->echoing = 1;
5782 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5783 ssh->ospeed, ssh->ispeed);
5784 ssh->got_pty = TRUE;
5787 ssh->editing = ssh->echoing = 1;
5790 if (conf_get_int(ssh->conf, CONF_compression)) {
5791 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5795 if (pktin->type != SSH1_SMSG_SUCCESS
5796 && pktin->type != SSH1_SMSG_FAILURE) {
5797 bombout(("Protocol confusion"));
5799 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5800 c_write_str(ssh, "Server refused to compress\r\n");
5802 logevent("Started compression");
5803 ssh->v1_compressing = TRUE;
5804 ssh->cs_comp_ctx = zlib_compress_init();
5805 logevent("Initialised zlib (RFC1950) compression");
5806 ssh->sc_comp_ctx = zlib_decompress_init();
5807 logevent("Initialised zlib (RFC1950) decompression");
5811 * Start the shell or command.
5813 * Special case: if the first-choice command is an SSH-2
5814 * subsystem (hence not usable here) and the second choice
5815 * exists, we fall straight back to that.
5818 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
5820 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
5821 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
5822 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
5823 ssh->fallback_cmd = TRUE;
5826 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
5828 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
5829 logevent("Started session");
5832 ssh->state = SSH_STATE_SESSION;
5833 if (ssh->size_needed)
5834 ssh_size(ssh, ssh->term_width, ssh->term_height);
5835 if (ssh->eof_needed)
5836 ssh_special(ssh, TS_EOF);
5839 ldisc_echoedit_update(ssh->ldisc); /* cause ldisc to notice changes */
5841 ssh->channels = newtree234(ssh_channelcmp);
5845 * By this point, most incoming packets are already being
5846 * handled by the dispatch table, and we need only pay
5847 * attention to the unusual ones.
5852 if (pktin->type == SSH1_SMSG_SUCCESS) {
5853 /* may be from EXEC_SHELL on some servers */
5854 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5855 /* may be from EXEC_SHELL on some servers
5856 * if no pty is available or in other odd cases. Ignore */
5858 bombout(("Strange packet received: type %d", pktin->type));
5863 int len = min(inlen, 512);
5864 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
5865 PKT_INT, len, PKT_DATA, in, len,
5877 * Handle the top-level SSH-2 protocol.
5879 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
5884 ssh_pkt_getstring(pktin, &msg, &msglen);
5885 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
5888 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
5890 /* log reason code in disconnect message */
5894 ssh_pkt_getstring(pktin, &msg, &msglen);
5895 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
5898 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
5900 /* Do nothing, because we're ignoring it! Duhh. */
5903 static void ssh1_protocol_setup(Ssh ssh)
5908 * Most messages are handled by the coroutines.
5910 for (i = 0; i < 256; i++)
5911 ssh->packet_dispatch[i] = NULL;
5914 * These special message types we install handlers for.
5916 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
5917 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
5918 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
5921 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
5922 struct Packet *pktin)
5924 unsigned char *in=(unsigned char*)vin;
5925 if (ssh->state == SSH_STATE_CLOSED)
5928 if (pktin && ssh->packet_dispatch[pktin->type]) {
5929 ssh->packet_dispatch[pktin->type](ssh, pktin);
5933 if (!ssh->protocol_initial_phase_done) {
5934 if (do_ssh1_login(ssh, in, inlen, pktin))
5935 ssh->protocol_initial_phase_done = TRUE;
5940 do_ssh1_connection(ssh, in, inlen, pktin);
5944 * Utility routine for decoding comma-separated strings in KEXINIT.
5946 static int in_commasep_string(char const *needle, char const *haystack,
5950 if (!needle || !haystack) /* protect against null pointers */
5952 needlen = strlen(needle);
5955 * Is it at the start of the string?
5957 if (haylen >= needlen && /* haystack is long enough */
5958 !memcmp(needle, haystack, needlen) && /* initial match */
5959 (haylen == needlen || haystack[needlen] == ',')
5960 /* either , or EOS follows */
5964 * If not, search for the next comma and resume after that.
5965 * If no comma found, terminate.
5967 while (haylen > 0 && *haystack != ',')
5968 haylen--, haystack++;
5971 haylen--, haystack++; /* skip over comma itself */
5976 * Similar routine for checking whether we have the first string in a list.
5978 static int first_in_commasep_string(char const *needle, char const *haystack,
5982 if (!needle || !haystack) /* protect against null pointers */
5984 needlen = strlen(needle);
5986 * Is it at the start of the string?
5988 if (haylen >= needlen && /* haystack is long enough */
5989 !memcmp(needle, haystack, needlen) && /* initial match */
5990 (haylen == needlen || haystack[needlen] == ',')
5991 /* either , or EOS follows */
5998 * Add a value to the comma-separated string at the end of the packet.
5999 * If the value is already in the string, don't bother adding it again.
6001 static void ssh2_pkt_addstring_commasep(struct Packet *pkt, const char *data)
6003 if (in_commasep_string(data, (char *)pkt->data + pkt->savedpos,
6004 pkt->length - pkt->savedpos)) return;
6005 if (pkt->length - pkt->savedpos > 0)
6006 ssh_pkt_addstring_str(pkt, ",");
6007 ssh_pkt_addstring_str(pkt, data);
6012 * SSH-2 key creation method.
6013 * (Currently assumes 2 lots of any hash are sufficient to generate
6014 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
6016 #define SSH2_MKKEY_ITERS (2)
6017 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
6018 unsigned char *keyspace)
6020 const struct ssh_hash *h = ssh->kex->hash;
6022 /* First hlen bytes. */
6024 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6025 hash_mpint(h, s, K);
6026 h->bytes(s, H, h->hlen);
6027 h->bytes(s, &chr, 1);
6028 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
6029 h->final(s, keyspace);
6030 /* Next hlen bytes. */
6032 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6033 hash_mpint(h, s, K);
6034 h->bytes(s, H, h->hlen);
6035 h->bytes(s, keyspace, h->hlen);
6036 h->final(s, keyspace + h->hlen);
6040 * Handle the SSH-2 transport layer.
6042 static void do_ssh2_transport(Ssh ssh, void *vin, int inlen,
6043 struct Packet *pktin)
6045 unsigned char *in = (unsigned char *)vin;
6046 struct do_ssh2_transport_state {
6048 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
6049 Bignum p, g, e, f, K;
6052 int kex_init_value, kex_reply_value;
6053 const struct ssh_mac **maclist;
6055 const struct ssh2_cipher *cscipher_tobe;
6056 const struct ssh2_cipher *sccipher_tobe;
6057 const struct ssh_mac *csmac_tobe;
6058 const struct ssh_mac *scmac_tobe;
6059 const struct ssh_compress *cscomp_tobe;
6060 const struct ssh_compress *sccomp_tobe;
6061 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
6062 int hostkeylen, siglen, rsakeylen;
6063 void *hkey; /* actual host key */
6064 void *rsakey; /* for RSA kex */
6065 void *eckey; /* for ECDH kex */
6066 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
6067 int n_preferred_kex;
6068 const struct ssh_kexes *preferred_kex[KEX_MAX];
6069 int n_preferred_ciphers;
6070 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
6071 const struct ssh_compress *preferred_comp;
6072 int userauth_succeeded; /* for delayed compression */
6073 int pending_compression;
6074 int got_session_id, activated_authconn;
6075 struct Packet *pktout;
6080 crState(do_ssh2_transport_state);
6082 assert(!ssh->bare_connection);
6086 s->cscipher_tobe = s->sccipher_tobe = NULL;
6087 s->csmac_tobe = s->scmac_tobe = NULL;
6088 s->cscomp_tobe = s->sccomp_tobe = NULL;
6090 s->got_session_id = s->activated_authconn = FALSE;
6091 s->userauth_succeeded = FALSE;
6092 s->pending_compression = FALSE;
6095 * Be prepared to work around the buggy MAC problem.
6097 if (ssh->remote_bugs & BUG_SSH2_HMAC)
6098 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
6100 s->maclist = macs, s->nmacs = lenof(macs);
6103 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
6108 * Set up the preferred key exchange. (NULL => warn below here)
6110 s->n_preferred_kex = 0;
6111 for (i = 0; i < KEX_MAX; i++) {
6112 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
6114 s->preferred_kex[s->n_preferred_kex++] =
6115 &ssh_diffiehellman_gex;
6118 s->preferred_kex[s->n_preferred_kex++] =
6119 &ssh_diffiehellman_group14;
6122 s->preferred_kex[s->n_preferred_kex++] =
6123 &ssh_diffiehellman_group1;
6126 s->preferred_kex[s->n_preferred_kex++] =
6130 s->preferred_kex[s->n_preferred_kex++] =
6134 /* Flag for later. Don't bother if it's the last in
6136 if (i < KEX_MAX - 1) {
6137 s->preferred_kex[s->n_preferred_kex++] = NULL;
6144 * Set up the preferred ciphers. (NULL => warn below here)
6146 s->n_preferred_ciphers = 0;
6147 for (i = 0; i < CIPHER_MAX; i++) {
6148 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
6149 case CIPHER_BLOWFISH:
6150 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
6153 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
6154 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
6158 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
6161 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
6163 case CIPHER_ARCFOUR:
6164 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
6167 /* Flag for later. Don't bother if it's the last in
6169 if (i < CIPHER_MAX - 1) {
6170 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
6177 * Set up preferred compression.
6179 if (conf_get_int(ssh->conf, CONF_compression))
6180 s->preferred_comp = &ssh_zlib;
6182 s->preferred_comp = &ssh_comp_none;
6185 * Enable queueing of outgoing auth- or connection-layer
6186 * packets while we are in the middle of a key exchange.
6188 ssh->queueing = TRUE;
6191 * Flag that KEX is in progress.
6193 ssh->kex_in_progress = TRUE;
6196 * Construct and send our key exchange packet.
6198 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
6199 for (i = 0; i < 16; i++)
6200 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
6201 /* List key exchange algorithms. */
6202 ssh2_pkt_addstring_start(s->pktout);
6203 for (i = 0; i < s->n_preferred_kex; i++) {
6204 const struct ssh_kexes *k = s->preferred_kex[i];
6205 if (!k) continue; /* warning flag */
6206 for (j = 0; j < k->nkexes; j++)
6207 ssh2_pkt_addstring_commasep(s->pktout, k->list[j]->name);
6209 /* List server host key algorithms. */
6210 if (!s->got_session_id) {
6212 * In the first key exchange, we list all the algorithms
6213 * we're prepared to cope with.
6215 ssh2_pkt_addstring_start(s->pktout);
6216 for (i = 0; i < lenof(hostkey_algs); i++)
6217 ssh2_pkt_addstring_commasep(s->pktout, hostkey_algs[i]->name);
6220 * In subsequent key exchanges, we list only the kex
6221 * algorithm that was selected in the first key exchange,
6222 * so that we keep getting the same host key and hence
6223 * don't have to interrupt the user's session to ask for
6227 ssh2_pkt_addstring(s->pktout, ssh->hostkey->name);
6229 /* List encryption algorithms (client->server then server->client). */
6230 for (k = 0; k < 2; k++) {
6231 ssh2_pkt_addstring_start(s->pktout);
6232 for (i = 0; i < s->n_preferred_ciphers; i++) {
6233 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6234 if (!c) continue; /* warning flag */
6235 for (j = 0; j < c->nciphers; j++)
6236 ssh2_pkt_addstring_commasep(s->pktout, c->list[j]->name);
6239 /* List MAC algorithms (client->server then server->client). */
6240 for (j = 0; j < 2; j++) {
6241 ssh2_pkt_addstring_start(s->pktout);
6242 for (i = 0; i < s->nmacs; i++)
6243 ssh2_pkt_addstring_commasep(s->pktout, s->maclist[i]->name);
6245 /* List client->server compression algorithms,
6246 * then server->client compression algorithms. (We use the
6247 * same set twice.) */
6248 for (j = 0; j < 2; j++) {
6249 ssh2_pkt_addstring_start(s->pktout);
6250 assert(lenof(compressions) > 1);
6251 /* Prefer non-delayed versions */
6252 ssh2_pkt_addstring_commasep(s->pktout, s->preferred_comp->name);
6253 /* We don't even list delayed versions of algorithms until
6254 * they're allowed to be used, to avoid a race. See the end of
6256 if (s->userauth_succeeded && s->preferred_comp->delayed_name)
6257 ssh2_pkt_addstring_commasep(s->pktout,
6258 s->preferred_comp->delayed_name);
6259 for (i = 0; i < lenof(compressions); i++) {
6260 const struct ssh_compress *c = compressions[i];
6261 ssh2_pkt_addstring_commasep(s->pktout, c->name);
6262 if (s->userauth_succeeded && c->delayed_name)
6263 ssh2_pkt_addstring_commasep(s->pktout, c->delayed_name);
6266 /* List client->server languages. Empty list. */
6267 ssh2_pkt_addstring_start(s->pktout);
6268 /* List server->client languages. Empty list. */
6269 ssh2_pkt_addstring_start(s->pktout);
6270 /* First KEX packet does _not_ follow, because we're not that brave. */
6271 ssh2_pkt_addbool(s->pktout, FALSE);
6273 ssh2_pkt_adduint32(s->pktout, 0);
6276 s->our_kexinitlen = s->pktout->length - 5;
6277 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
6278 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
6280 ssh2_pkt_send_noqueue(ssh, s->pktout);
6283 crWaitUntilV(pktin);
6286 * Now examine the other side's KEXINIT to see what we're up
6290 char *str, *preferred;
6293 if (pktin->type != SSH2_MSG_KEXINIT) {
6294 bombout(("expected key exchange packet from server"));
6298 ssh->hostkey = NULL;
6299 s->cscipher_tobe = NULL;
6300 s->sccipher_tobe = NULL;
6301 s->csmac_tobe = NULL;
6302 s->scmac_tobe = NULL;
6303 s->cscomp_tobe = NULL;
6304 s->sccomp_tobe = NULL;
6305 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
6307 pktin->savedpos += 16; /* skip garbage cookie */
6308 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
6310 bombout(("KEXINIT packet was incomplete"));
6315 for (i = 0; i < s->n_preferred_kex; i++) {
6316 const struct ssh_kexes *k = s->preferred_kex[i];
6320 for (j = 0; j < k->nkexes; j++) {
6321 if (!preferred) preferred = k->list[j]->name;
6322 if (in_commasep_string(k->list[j]->name, str, len)) {
6323 ssh->kex = k->list[j];
6332 bombout(("Couldn't agree a key exchange algorithm"
6333 " (available: %.*s)", len, str));
6337 * Note that the server's guess is considered wrong if it doesn't match
6338 * the first algorithm in our list, even if it's still the algorithm
6341 s->guessok = first_in_commasep_string(preferred, str, len);
6342 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
6344 bombout(("KEXINIT packet was incomplete"));
6347 for (i = 0; i < lenof(hostkey_algs); i++) {
6348 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
6349 ssh->hostkey = hostkey_algs[i];
6353 if (!ssh->hostkey) {
6354 bombout(("Couldn't agree a host key algorithm"
6355 " (available: %.*s)", len, str));
6359 s->guessok = s->guessok &&
6360 first_in_commasep_string(hostkey_algs[0]->name, str, len);
6361 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
6363 bombout(("KEXINIT packet was incomplete"));
6366 for (i = 0; i < s->n_preferred_ciphers; i++) {
6367 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6369 s->warn_cscipher = TRUE;
6371 for (j = 0; j < c->nciphers; j++) {
6372 if (in_commasep_string(c->list[j]->name, str, len)) {
6373 s->cscipher_tobe = c->list[j];
6378 if (s->cscipher_tobe)
6381 if (!s->cscipher_tobe) {
6382 bombout(("Couldn't agree a client-to-server cipher"
6383 " (available: %.*s)", len, str));
6387 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
6389 bombout(("KEXINIT packet was incomplete"));
6392 for (i = 0; i < s->n_preferred_ciphers; i++) {
6393 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6395 s->warn_sccipher = TRUE;
6397 for (j = 0; j < c->nciphers; j++) {
6398 if (in_commasep_string(c->list[j]->name, str, len)) {
6399 s->sccipher_tobe = c->list[j];
6404 if (s->sccipher_tobe)
6407 if (!s->sccipher_tobe) {
6408 bombout(("Couldn't agree a server-to-client cipher"
6409 " (available: %.*s)", len, str));
6413 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
6415 bombout(("KEXINIT packet was incomplete"));
6418 for (i = 0; i < s->nmacs; i++) {
6419 if (in_commasep_string(s->maclist[i]->name, str, len)) {
6420 s->csmac_tobe = s->maclist[i];
6424 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
6426 bombout(("KEXINIT packet was incomplete"));
6429 for (i = 0; i < s->nmacs; i++) {
6430 if (in_commasep_string(s->maclist[i]->name, str, len)) {
6431 s->scmac_tobe = s->maclist[i];
6435 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
6437 bombout(("KEXINIT packet was incomplete"));
6440 for (i = 0; i < lenof(compressions) + 1; i++) {
6441 const struct ssh_compress *c =
6442 i == 0 ? s->preferred_comp : compressions[i - 1];
6443 if (in_commasep_string(c->name, str, len)) {
6446 } else if (in_commasep_string(c->delayed_name, str, len)) {
6447 if (s->userauth_succeeded) {
6451 s->pending_compression = TRUE; /* try this later */
6455 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
6457 bombout(("KEXINIT packet was incomplete"));
6460 for (i = 0; i < lenof(compressions) + 1; i++) {
6461 const struct ssh_compress *c =
6462 i == 0 ? s->preferred_comp : compressions[i - 1];
6463 if (in_commasep_string(c->name, str, len)) {
6466 } else if (in_commasep_string(c->delayed_name, str, len)) {
6467 if (s->userauth_succeeded) {
6471 s->pending_compression = TRUE; /* try this later */
6475 if (s->pending_compression) {
6476 logevent("Server supports delayed compression; "
6477 "will try this later");
6479 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
6480 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
6481 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
6483 ssh->exhash = ssh->kex->hash->init();
6484 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
6485 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
6486 hash_string(ssh->kex->hash, ssh->exhash,
6487 s->our_kexinit, s->our_kexinitlen);
6488 sfree(s->our_kexinit);
6489 /* Include the type byte in the hash of server's KEXINIT */
6490 hash_string(ssh->kex->hash, ssh->exhash,
6491 pktin->body - 1, pktin->length + 1);
6494 ssh_set_frozen(ssh, 1);
6495 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
6497 ssh_dialog_callback, ssh);
6498 if (s->dlgret < 0) {
6502 bombout(("Unexpected data from server while"
6503 " waiting for user response"));
6506 } while (pktin || inlen > 0);
6507 s->dlgret = ssh->user_response;
6509 ssh_set_frozen(ssh, 0);
6510 if (s->dlgret == 0) {
6511 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
6517 if (s->warn_cscipher) {
6518 ssh_set_frozen(ssh, 1);
6519 s->dlgret = askalg(ssh->frontend,
6520 "client-to-server cipher",
6521 s->cscipher_tobe->name,
6522 ssh_dialog_callback, ssh);
6523 if (s->dlgret < 0) {
6527 bombout(("Unexpected data from server while"
6528 " waiting for user response"));
6531 } while (pktin || inlen > 0);
6532 s->dlgret = ssh->user_response;
6534 ssh_set_frozen(ssh, 0);
6535 if (s->dlgret == 0) {
6536 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6542 if (s->warn_sccipher) {
6543 ssh_set_frozen(ssh, 1);
6544 s->dlgret = askalg(ssh->frontend,
6545 "server-to-client cipher",
6546 s->sccipher_tobe->name,
6547 ssh_dialog_callback, ssh);
6548 if (s->dlgret < 0) {
6552 bombout(("Unexpected data from server while"
6553 " waiting for user response"));
6556 } while (pktin || inlen > 0);
6557 s->dlgret = ssh->user_response;
6559 ssh_set_frozen(ssh, 0);
6560 if (s->dlgret == 0) {
6561 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6567 if (s->ignorepkt) /* first_kex_packet_follows */
6568 crWaitUntilV(pktin); /* Ignore packet */
6571 if (ssh->kex->main_type == KEXTYPE_DH) {
6573 * Work out the number of bits of key we will need from the
6574 * key exchange. We start with the maximum key length of
6580 csbits = s->cscipher_tobe->keylen;
6581 scbits = s->sccipher_tobe->keylen;
6582 s->nbits = (csbits > scbits ? csbits : scbits);
6584 /* The keys only have hlen-bit entropy, since they're based on
6585 * a hash. So cap the key size at hlen bits. */
6586 if (s->nbits > ssh->kex->hash->hlen * 8)
6587 s->nbits = ssh->kex->hash->hlen * 8;
6590 * If we're doing Diffie-Hellman group exchange, start by
6591 * requesting a group.
6593 if (!ssh->kex->pdata) {
6594 logevent("Doing Diffie-Hellman group exchange");
6595 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
6597 * Work out how big a DH group we will need to allow that
6600 s->pbits = 512 << ((s->nbits - 1) / 64);
6601 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6602 ssh2_pkt_adduint32(s->pktout, s->pbits);
6603 ssh2_pkt_send_noqueue(ssh, s->pktout);
6605 crWaitUntilV(pktin);
6606 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6607 bombout(("expected key exchange group packet from server"));
6610 s->p = ssh2_pkt_getmp(pktin);
6611 s->g = ssh2_pkt_getmp(pktin);
6612 if (!s->p || !s->g) {
6613 bombout(("unable to read mp-ints from incoming group packet"));
6616 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6617 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6618 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6620 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
6621 ssh->kex_ctx = dh_setup_group(ssh->kex);
6622 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6623 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6624 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6625 ssh->kex->groupname);
6628 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6629 ssh->kex->hash->text_name);
6631 * Now generate and send e for Diffie-Hellman.
6633 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6634 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6635 s->pktout = ssh2_pkt_init(s->kex_init_value);
6636 ssh2_pkt_addmp(s->pktout, s->e);
6637 ssh2_pkt_send_noqueue(ssh, s->pktout);
6639 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
6640 crWaitUntilV(pktin);
6641 if (pktin->type != s->kex_reply_value) {
6642 bombout(("expected key exchange reply packet from server"));
6645 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
6646 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6647 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6648 s->f = ssh2_pkt_getmp(pktin);
6650 bombout(("unable to parse key exchange reply packet"));
6653 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6656 const char *err = dh_validate_f(ssh->kex_ctx, s->f);
6658 bombout(("key exchange reply failed validation: %s", err));
6662 s->K = dh_find_K(ssh->kex_ctx, s->f);
6664 /* We assume everything from now on will be quick, and it might
6665 * involve user interaction. */
6666 set_busy_status(ssh->frontend, BUSY_NOT);
6668 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6669 if (!ssh->kex->pdata) {
6670 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
6671 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
6672 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
6674 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
6675 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
6677 dh_cleanup(ssh->kex_ctx);
6679 if (!ssh->kex->pdata) {
6683 } else if (ssh->kex->main_type == KEXTYPE_ECDH) {
6685 logeventf(ssh, "Doing ECDH key exchange with hash %s",
6686 ssh->kex->hash->text_name);
6687 ssh->pkt_kctx = SSH2_PKTCTX_ECDHKEX;
6690 if (!strcmp(ssh->kex->name, "ecdh-sha2-nistp256")) {
6691 s->eckey = ssh_ecdhkex_newkey(ec_p256());
6692 } else if (!strcmp(ssh->kex->name, "ecdh-sha2-nistp384")) {
6693 s->eckey = ssh_ecdhkex_newkey(ec_p384());
6694 } else if (!strcmp(ssh->kex->name, "ecdh-sha2-nistp521")) {
6695 s->eckey = ssh_ecdhkex_newkey(ec_p521());
6698 bombout(("Unable to generate key for ECDH"));
6704 int publicPointLength;
6705 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
6707 ssh_ecdhkex_freekey(s->eckey);
6708 bombout(("Unable to encode public key for ECDH"));
6711 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_ECDH_INIT);
6712 ssh2_pkt_addstring_start(s->pktout);
6713 ssh2_pkt_addstring_data(s->pktout, publicPoint, publicPointLength);
6717 ssh2_pkt_send_noqueue(ssh, s->pktout);
6719 crWaitUntilV(pktin);
6720 if (pktin->type != SSH2_MSG_KEX_ECDH_REPLY) {
6721 ssh_ecdhkex_freekey(s->eckey);
6722 bombout(("expected ECDH reply packet from server"));
6726 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6727 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6728 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6732 int publicPointLength;
6733 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
6735 ssh_ecdhkex_freekey(s->eckey);
6736 bombout(("Unable to encode public key for ECDH hash"));
6739 hash_string(ssh->kex->hash, ssh->exhash,
6740 publicPoint, publicPointLength);
6747 ssh_pkt_getstring(pktin, &keydata, &keylen);
6748 hash_string(ssh->kex->hash, ssh->exhash, keydata, keylen);
6749 s->K = ssh_ecdhkex_getkey(s->eckey, keydata, keylen);
6751 ssh_ecdhkex_freekey(s->eckey);
6752 bombout(("point received in ECDH was not valid"));
6757 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6759 ssh_ecdhkex_freekey(s->eckey);
6761 logeventf(ssh, "Doing RSA key exchange with hash %s",
6762 ssh->kex->hash->text_name);
6763 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
6765 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6768 crWaitUntilV(pktin);
6769 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
6770 bombout(("expected RSA public key packet from server"));
6774 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6775 hash_string(ssh->kex->hash, ssh->exhash,
6776 s->hostkeydata, s->hostkeylen);
6777 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6781 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
6782 s->rsakeydata = snewn(s->rsakeylen, char);
6783 memcpy(s->rsakeydata, keydata, s->rsakeylen);
6786 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
6788 sfree(s->rsakeydata);
6789 bombout(("unable to parse RSA public key from server"));
6793 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
6796 * Next, set up a shared secret K, of precisely KLEN -
6797 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6798 * RSA key modulus and HLEN is the bit length of the hash
6802 int klen = ssh_rsakex_klen(s->rsakey);
6803 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
6805 unsigned char *kstr1, *kstr2, *outstr;
6806 int kstr1len, kstr2len, outstrlen;
6808 s->K = bn_power_2(nbits - 1);
6810 for (i = 0; i < nbits; i++) {
6812 byte = random_byte();
6814 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
6818 * Encode this as an mpint.
6820 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
6821 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
6822 PUT_32BIT(kstr2, kstr1len);
6823 memcpy(kstr2 + 4, kstr1, kstr1len);
6826 * Encrypt it with the given RSA key.
6828 outstrlen = (klen + 7) / 8;
6829 outstr = snewn(outstrlen, unsigned char);
6830 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
6831 outstr, outstrlen, s->rsakey);
6834 * And send it off in a return packet.
6836 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
6837 ssh2_pkt_addstring_start(s->pktout);
6838 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
6839 ssh2_pkt_send_noqueue(ssh, s->pktout);
6841 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
6848 ssh_rsakex_freekey(s->rsakey);
6850 crWaitUntilV(pktin);
6851 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
6852 sfree(s->rsakeydata);
6853 bombout(("expected signature packet from server"));
6857 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6859 sfree(s->rsakeydata);
6862 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
6863 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
6864 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
6866 ssh->kex_ctx = NULL;
6869 debug(("Exchange hash is:\n"));
6870 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
6874 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
6875 (char *)s->exchange_hash,
6876 ssh->kex->hash->hlen)) {
6877 bombout(("Server's host key did not match the signature supplied"));
6881 s->keystr = ssh->hostkey->fmtkey(s->hkey);
6882 if (!s->got_session_id) {
6884 * Authenticate remote host: verify host key. (We've already
6885 * checked the signature of the exchange hash.)
6887 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
6888 logevent("Host key fingerprint is:");
6889 logevent(s->fingerprint);
6890 /* First check against manually configured host keys. */
6891 s->dlgret = verify_ssh_manual_host_key(ssh, s->fingerprint,
6892 ssh->hostkey, s->hkey);
6893 if (s->dlgret == 0) { /* did not match */
6894 bombout(("Host key did not appear in manually configured list"));
6896 } else if (s->dlgret < 0) { /* none configured; use standard handling */
6897 ssh_set_frozen(ssh, 1);
6898 s->dlgret = verify_ssh_host_key(ssh->frontend,
6899 ssh->savedhost, ssh->savedport,
6900 ssh->hostkey->keytype, s->keystr,
6902 ssh_dialog_callback, ssh);
6903 if (s->dlgret < 0) {
6907 bombout(("Unexpected data from server while waiting"
6908 " for user host key response"));
6911 } while (pktin || inlen > 0);
6912 s->dlgret = ssh->user_response;
6914 ssh_set_frozen(ssh, 0);
6915 if (s->dlgret == 0) {
6916 ssh_disconnect(ssh, "Aborted at host key verification", NULL,
6921 sfree(s->fingerprint);
6923 * Save this host key, to check against the one presented in
6924 * subsequent rekeys.
6926 ssh->hostkey_str = s->keystr;
6929 * In a rekey, we never present an interactive host key
6930 * verification request to the user. Instead, we simply
6931 * enforce that the key we're seeing this time is identical to
6932 * the one we saw before.
6934 if (strcmp(ssh->hostkey_str, s->keystr)) {
6935 bombout(("Host key was different in repeat key exchange"));
6940 ssh->hostkey->freekey(s->hkey);
6943 * The exchange hash from the very first key exchange is also
6944 * the session id, used in session key construction and
6947 if (!s->got_session_id) {
6948 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
6949 memcpy(ssh->v2_session_id, s->exchange_hash,
6950 sizeof(s->exchange_hash));
6951 ssh->v2_session_id_len = ssh->kex->hash->hlen;
6952 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
6953 s->got_session_id = TRUE;
6957 * Send SSH2_MSG_NEWKEYS.
6959 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
6960 ssh2_pkt_send_noqueue(ssh, s->pktout);
6961 ssh->outgoing_data_size = 0; /* start counting from here */
6964 * We've sent client NEWKEYS, so create and initialise
6965 * client-to-server session keys.
6967 if (ssh->cs_cipher_ctx)
6968 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6969 ssh->cscipher = s->cscipher_tobe;
6970 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
6972 if (ssh->cs_mac_ctx)
6973 ssh->csmac->free_context(ssh->cs_mac_ctx);
6974 ssh->csmac = s->csmac_tobe;
6975 ssh->cs_mac_ctx = ssh->csmac->make_context();
6977 if (ssh->cs_comp_ctx)
6978 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6979 ssh->cscomp = s->cscomp_tobe;
6980 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
6983 * Set IVs on client-to-server keys. Here we use the exchange
6984 * hash from the _first_ key exchange.
6987 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6988 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6989 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
6990 assert((ssh->cscipher->keylen+7) / 8 <=
6991 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6992 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
6993 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
6994 assert(ssh->cscipher->blksize <=
6995 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6996 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
6997 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
6998 assert(ssh->csmac->len <=
6999 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7000 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
7001 smemclr(keyspace, sizeof(keyspace));
7004 logeventf(ssh, "Initialised %.200s client->server encryption",
7005 ssh->cscipher->text_name);
7006 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
7007 ssh->csmac->text_name);
7008 if (ssh->cscomp->text_name)
7009 logeventf(ssh, "Initialised %s compression",
7010 ssh->cscomp->text_name);
7013 * Now our end of the key exchange is complete, we can send all
7014 * our queued higher-layer packets.
7016 ssh->queueing = FALSE;
7017 ssh2_pkt_queuesend(ssh);
7020 * Expect SSH2_MSG_NEWKEYS from server.
7022 crWaitUntilV(pktin);
7023 if (pktin->type != SSH2_MSG_NEWKEYS) {
7024 bombout(("expected new-keys packet from server"));
7027 ssh->incoming_data_size = 0; /* start counting from here */
7030 * We've seen server NEWKEYS, so create and initialise
7031 * server-to-client session keys.
7033 if (ssh->sc_cipher_ctx)
7034 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7035 ssh->sccipher = s->sccipher_tobe;
7036 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
7038 if (ssh->sc_mac_ctx)
7039 ssh->scmac->free_context(ssh->sc_mac_ctx);
7040 ssh->scmac = s->scmac_tobe;
7041 ssh->sc_mac_ctx = ssh->scmac->make_context();
7043 if (ssh->sc_comp_ctx)
7044 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7045 ssh->sccomp = s->sccomp_tobe;
7046 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
7049 * Set IVs on server-to-client keys. Here we use the exchange
7050 * hash from the _first_ key exchange.
7053 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
7054 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7055 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
7056 assert((ssh->sccipher->keylen+7) / 8 <=
7057 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7058 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
7059 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
7060 assert(ssh->sccipher->blksize <=
7061 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7062 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
7063 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
7064 assert(ssh->scmac->len <=
7065 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7066 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
7067 smemclr(keyspace, sizeof(keyspace));
7069 logeventf(ssh, "Initialised %.200s server->client encryption",
7070 ssh->sccipher->text_name);
7071 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
7072 ssh->scmac->text_name);
7073 if (ssh->sccomp->text_name)
7074 logeventf(ssh, "Initialised %s decompression",
7075 ssh->sccomp->text_name);
7078 * Free shared secret.
7083 * Key exchange is over. Loop straight back round if we have a
7084 * deferred rekey reason.
7086 if (ssh->deferred_rekey_reason) {
7087 logevent(ssh->deferred_rekey_reason);
7089 ssh->deferred_rekey_reason = NULL;
7090 goto begin_key_exchange;
7094 * Otherwise, schedule a timer for our next rekey.
7096 ssh->kex_in_progress = FALSE;
7097 ssh->last_rekey = GETTICKCOUNT();
7098 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
7099 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7103 * Now we're encrypting. Begin returning 1 to the protocol main
7104 * function so that other things can run on top of the
7105 * transport. If we ever see a KEXINIT, we must go back to the
7108 * We _also_ go back to the start if we see pktin==NULL and
7109 * inlen negative, because this is a special signal meaning
7110 * `initiate client-driven rekey', and `in' contains a message
7111 * giving the reason for the rekey.
7113 * inlen==-1 means always initiate a rekey;
7114 * inlen==-2 means that userauth has completed successfully and
7115 * we should consider rekeying (for delayed compression).
7117 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
7118 (!pktin && inlen < 0))) {
7120 if (!ssh->protocol_initial_phase_done) {
7121 ssh->protocol_initial_phase_done = TRUE;
7123 * Allow authconn to initialise itself.
7125 do_ssh2_authconn(ssh, NULL, 0, NULL);
7130 logevent("Server initiated key re-exchange");
7134 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
7135 * delayed compression, if it's available.
7137 * draft-miller-secsh-compression-delayed-00 says that you
7138 * negotiate delayed compression in the first key exchange, and
7139 * both sides start compressing when the server has sent
7140 * USERAUTH_SUCCESS. This has a race condition -- the server
7141 * can't know when the client has seen it, and thus which incoming
7142 * packets it should treat as compressed.
7144 * Instead, we do the initial key exchange without offering the
7145 * delayed methods, but note if the server offers them; when we
7146 * get here, if a delayed method was available that was higher
7147 * on our list than what we got, we initiate a rekey in which we
7148 * _do_ list the delayed methods (and hopefully get it as a
7149 * result). Subsequent rekeys will do the same.
7151 assert(!s->userauth_succeeded); /* should only happen once */
7152 s->userauth_succeeded = TRUE;
7153 if (!s->pending_compression)
7154 /* Can't see any point rekeying. */
7155 goto wait_for_rekey; /* this is utterly horrid */
7156 /* else fall through to rekey... */
7157 s->pending_compression = FALSE;
7160 * Now we've decided to rekey.
7162 * Special case: if the server bug is set that doesn't
7163 * allow rekeying, we give a different log message and
7164 * continue waiting. (If such a server _initiates_ a rekey,
7165 * we process it anyway!)
7167 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
7168 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
7170 /* Reset the counters, so that at least this message doesn't
7171 * hit the event log _too_ often. */
7172 ssh->outgoing_data_size = 0;
7173 ssh->incoming_data_size = 0;
7174 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
7176 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7179 goto wait_for_rekey; /* this is still utterly horrid */
7181 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
7184 goto begin_key_exchange;
7190 * Add data to an SSH-2 channel output buffer.
7192 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
7195 bufchain_add(&c->v.v2.outbuffer, buf, len);
7199 * Attempt to send data on an SSH-2 channel.
7201 static int ssh2_try_send(struct ssh_channel *c)
7204 struct Packet *pktout;
7207 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
7210 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
7211 if ((unsigned)len > c->v.v2.remwindow)
7212 len = c->v.v2.remwindow;
7213 if ((unsigned)len > c->v.v2.remmaxpkt)
7214 len = c->v.v2.remmaxpkt;
7215 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
7216 ssh2_pkt_adduint32(pktout, c->remoteid);
7217 ssh2_pkt_addstring_start(pktout);
7218 ssh2_pkt_addstring_data(pktout, data, len);
7219 ssh2_pkt_send(ssh, pktout);
7220 bufchain_consume(&c->v.v2.outbuffer, len);
7221 c->v.v2.remwindow -= len;
7225 * After having sent as much data as we can, return the amount
7228 ret = bufchain_size(&c->v.v2.outbuffer);
7231 * And if there's no data pending but we need to send an EOF, send
7234 if (!ret && c->pending_eof)
7235 ssh_channel_try_eof(c);
7240 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
7243 if (c->closes & CLOSES_SENT_EOF)
7244 return; /* don't send on channels we've EOFed */
7245 bufsize = ssh2_try_send(c);
7248 case CHAN_MAINSESSION:
7249 /* stdin need not receive an unthrottle
7250 * notification since it will be polled */
7253 x11_unthrottle(c->u.x11.xconn);
7256 /* agent sockets are request/response and need no
7257 * buffer management */
7260 pfd_unthrottle(c->u.pfd.pf);
7266 static int ssh_is_simple(Ssh ssh)
7269 * We use the 'simple' variant of the SSH protocol if we're asked
7270 * to, except not if we're also doing connection-sharing (either
7271 * tunnelling our packets over an upstream or expecting to be
7272 * tunnelled over ourselves), since then the assumption that we
7273 * have only one channel to worry about is not true after all.
7275 return (conf_get_int(ssh->conf, CONF_ssh_simple) &&
7276 !ssh->bare_connection && !ssh->connshare);
7280 * Set up most of a new ssh_channel for SSH-2.
7282 static void ssh2_channel_init(struct ssh_channel *c)
7285 c->localid = alloc_channel_id(ssh);
7287 c->pending_eof = FALSE;
7288 c->throttling_conn = FALSE;
7289 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
7290 ssh_is_simple(ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
7291 c->v.v2.chanreq_head = NULL;
7292 c->v.v2.throttle_state = UNTHROTTLED;
7293 bufchain_init(&c->v.v2.outbuffer);
7297 * Construct the common parts of a CHANNEL_OPEN.
7299 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c, char *type)
7301 struct Packet *pktout;
7303 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7304 ssh2_pkt_addstring(pktout, type);
7305 ssh2_pkt_adduint32(pktout, c->localid);
7306 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7307 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7312 * CHANNEL_FAILURE doesn't come with any indication of what message
7313 * caused it, so we have to keep track of the outstanding
7314 * CHANNEL_REQUESTs ourselves.
7316 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
7317 cchandler_fn_t handler, void *ctx)
7319 struct outstanding_channel_request *ocr =
7320 snew(struct outstanding_channel_request);
7322 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7323 ocr->handler = handler;
7326 if (!c->v.v2.chanreq_head)
7327 c->v.v2.chanreq_head = ocr;
7329 c->v.v2.chanreq_tail->next = ocr;
7330 c->v.v2.chanreq_tail = ocr;
7334 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
7335 * NULL then a reply will be requested and the handler will be called
7336 * when it arrives. The returned packet is ready to have any
7337 * request-specific data added and be sent. Note that if a handler is
7338 * provided, it's essential that the request actually be sent.
7340 * The handler will usually be passed the response packet in pktin. If
7341 * pktin is NULL, this means that no reply will ever be forthcoming
7342 * (e.g. because the entire connection is being destroyed, or because
7343 * the server initiated channel closure before we saw the response)
7344 * and the handler should free any storage it's holding.
7346 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c, char *type,
7347 cchandler_fn_t handler, void *ctx)
7349 struct Packet *pktout;
7351 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7352 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7353 ssh2_pkt_adduint32(pktout, c->remoteid);
7354 ssh2_pkt_addstring(pktout, type);
7355 ssh2_pkt_addbool(pktout, handler != NULL);
7356 if (handler != NULL)
7357 ssh2_queue_chanreq_handler(c, handler, ctx);
7362 * Potentially enlarge the window on an SSH-2 channel.
7364 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
7366 static void ssh2_set_window(struct ssh_channel *c, int newwin)
7371 * Never send WINDOW_ADJUST for a channel that the remote side has
7372 * already sent EOF on; there's no point, since it won't be
7373 * sending any more data anyway. Ditto if _we've_ already sent
7376 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
7380 * Also, never widen the window for an X11 channel when we're
7381 * still waiting to see its initial auth and may yet hand it off
7384 if (c->type == CHAN_X11 && c->u.x11.initial)
7388 * If the remote end has a habit of ignoring maxpkt, limit the
7389 * window so that it has no choice (assuming it doesn't ignore the
7392 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
7393 newwin = OUR_V2_MAXPKT;
7396 * Only send a WINDOW_ADJUST if there's significantly more window
7397 * available than the other end thinks there is. This saves us
7398 * sending a WINDOW_ADJUST for every character in a shell session.
7400 * "Significant" is arbitrarily defined as half the window size.
7402 if (newwin / 2 >= c->v.v2.locwindow) {
7403 struct Packet *pktout;
7407 * In order to keep track of how much window the client
7408 * actually has available, we'd like it to acknowledge each
7409 * WINDOW_ADJUST. We can't do that directly, so we accompany
7410 * it with a CHANNEL_REQUEST that has to be acknowledged.
7412 * This is only necessary if we're opening the window wide.
7413 * If we're not, then throughput is being constrained by
7414 * something other than the maximum window size anyway.
7416 if (newwin == c->v.v2.locmaxwin &&
7417 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
7418 up = snew(unsigned);
7419 *up = newwin - c->v.v2.locwindow;
7420 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
7421 ssh2_handle_winadj_response, up);
7422 ssh2_pkt_send(ssh, pktout);
7424 if (c->v.v2.throttle_state != UNTHROTTLED)
7425 c->v.v2.throttle_state = UNTHROTTLING;
7427 /* Pretend the WINDOW_ADJUST was acked immediately. */
7428 c->v.v2.remlocwin = newwin;
7429 c->v.v2.throttle_state = THROTTLED;
7431 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7432 ssh2_pkt_adduint32(pktout, c->remoteid);
7433 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
7434 ssh2_pkt_send(ssh, pktout);
7435 c->v.v2.locwindow = newwin;
7440 * Find the channel associated with a message. If there's no channel,
7441 * or it's not properly open, make a noise about it and return NULL.
7443 static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
7445 unsigned localid = ssh_pkt_getuint32(pktin);
7446 struct ssh_channel *c;
7448 c = find234(ssh->channels, &localid, ssh_channelfind);
7450 (c->type != CHAN_SHARING && c->halfopen &&
7451 pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
7452 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
7453 char *buf = dupprintf("Received %s for %s channel %u",
7454 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
7456 c ? "half-open" : "nonexistent", localid);
7457 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
7464 static void ssh2_handle_winadj_response(struct ssh_channel *c,
7465 struct Packet *pktin, void *ctx)
7467 unsigned *sizep = ctx;
7470 * Winadj responses should always be failures. However, at least
7471 * one server ("boks_sshd") is known to return SUCCESS for channel
7472 * requests it's never heard of, such as "winadj@putty". Raised
7473 * with foxt.com as bug 090916-090424, but for the sake of a quiet
7474 * life, we don't worry about what kind of response we got.
7477 c->v.v2.remlocwin += *sizep;
7480 * winadj messages are only sent when the window is fully open, so
7481 * if we get an ack of one, we know any pending unthrottle is
7484 if (c->v.v2.throttle_state == UNTHROTTLING)
7485 c->v.v2.throttle_state = UNTHROTTLED;
7488 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
7490 struct ssh_channel *c = ssh2_channel_msg(ssh, pktin);
7491 struct outstanding_channel_request *ocr;
7494 if (c->type == CHAN_SHARING) {
7495 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7496 pktin->body, pktin->length);
7499 ocr = c->v.v2.chanreq_head;
7501 ssh2_msg_unexpected(ssh, pktin);
7504 ocr->handler(c, pktin, ocr->ctx);
7505 c->v.v2.chanreq_head = ocr->next;
7508 * We may now initiate channel-closing procedures, if that
7509 * CHANNEL_REQUEST was the last thing outstanding before we send
7512 ssh2_channel_check_close(c);
7515 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
7517 struct ssh_channel *c;
7518 c = ssh2_channel_msg(ssh, pktin);
7521 if (c->type == CHAN_SHARING) {
7522 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7523 pktin->body, pktin->length);
7526 if (!(c->closes & CLOSES_SENT_EOF)) {
7527 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
7528 ssh2_try_send_and_unthrottle(ssh, c);
7532 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
7536 struct ssh_channel *c;
7537 c = ssh2_channel_msg(ssh, pktin);
7540 if (c->type == CHAN_SHARING) {
7541 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7542 pktin->body, pktin->length);
7545 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
7546 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
7547 return; /* extended but not stderr */
7548 ssh_pkt_getstring(pktin, &data, &length);
7551 c->v.v2.locwindow -= length;
7552 c->v.v2.remlocwin -= length;
7554 case CHAN_MAINSESSION:
7556 from_backend(ssh->frontend, pktin->type ==
7557 SSH2_MSG_CHANNEL_EXTENDED_DATA,
7561 bufsize = x11_send(c->u.x11.xconn, data, length);
7564 bufsize = pfd_send(c->u.pfd.pf, data, length);
7567 while (length > 0) {
7568 if (c->u.a.lensofar < 4) {
7569 unsigned int l = min(4 - c->u.a.lensofar,
7571 memcpy(c->u.a.msglen + c->u.a.lensofar,
7575 c->u.a.lensofar += l;
7577 if (c->u.a.lensofar == 4) {
7579 4 + GET_32BIT(c->u.a.msglen);
7580 c->u.a.message = snewn(c->u.a.totallen,
7582 memcpy(c->u.a.message, c->u.a.msglen, 4);
7584 if (c->u.a.lensofar >= 4 && length > 0) {
7586 min(c->u.a.totallen - c->u.a.lensofar,
7588 memcpy(c->u.a.message + c->u.a.lensofar,
7592 c->u.a.lensofar += l;
7594 if (c->u.a.lensofar == c->u.a.totallen) {
7597 c->u.a.outstanding_requests++;
7598 if (agent_query(c->u.a.message,
7601 ssh_agentf_callback, c))
7602 ssh_agentf_callback(c, reply, replylen);
7603 sfree(c->u.a.message);
7604 c->u.a.message = NULL;
7605 c->u.a.lensofar = 0;
7612 * If it looks like the remote end hit the end of its window,
7613 * and we didn't want it to do that, think about using a
7616 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
7617 c->v.v2.locmaxwin < 0x40000000)
7618 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
7620 * If we are not buffering too much data,
7621 * enlarge the window again at the remote side.
7622 * If we are buffering too much, we may still
7623 * need to adjust the window if the server's
7626 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
7627 c->v.v2.locmaxwin - bufsize : 0);
7629 * If we're either buffering way too much data, or if we're
7630 * buffering anything at all and we're in "simple" mode,
7631 * throttle the whole channel.
7633 if ((bufsize > c->v.v2.locmaxwin || (ssh_is_simple(ssh) && bufsize>0))
7634 && !c->throttling_conn) {
7635 c->throttling_conn = 1;
7636 ssh_throttle_conn(ssh, +1);
7641 static void ssh_check_termination(Ssh ssh)
7643 if (ssh->version == 2 &&
7644 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
7645 count234(ssh->channels) == 0 &&
7646 !(ssh->connshare && share_ndownstreams(ssh->connshare) > 0)) {
7648 * We used to send SSH_MSG_DISCONNECT here, because I'd
7649 * believed that _every_ conforming SSH-2 connection had to
7650 * end with a disconnect being sent by at least one side;
7651 * apparently I was wrong and it's perfectly OK to
7652 * unceremoniously slam the connection shut when you're done,
7653 * and indeed OpenSSH feels this is more polite than sending a
7654 * DISCONNECT. So now we don't.
7656 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
7660 void ssh_sharing_downstream_connected(Ssh ssh, unsigned id)
7662 logeventf(ssh, "Connection sharing downstream #%u connected", id);
7665 void ssh_sharing_downstream_disconnected(Ssh ssh, unsigned id)
7667 logeventf(ssh, "Connection sharing downstream #%u disconnected", id);
7668 ssh_check_termination(ssh);
7671 void ssh_sharing_logf(Ssh ssh, unsigned id, const char *logfmt, ...)
7676 va_start(ap, logfmt);
7677 buf = dupvprintf(logfmt, ap);
7680 logeventf(ssh, "Connection sharing downstream #%u: %s", id, buf);
7682 logeventf(ssh, "Connection sharing: %s", buf);
7686 static void ssh_channel_destroy(struct ssh_channel *c)
7691 case CHAN_MAINSESSION:
7692 ssh->mainchan = NULL;
7693 update_specials_menu(ssh->frontend);
7696 if (c->u.x11.xconn != NULL)
7697 x11_close(c->u.x11.xconn);
7698 logevent("Forwarded X11 connection terminated");
7701 sfree(c->u.a.message);
7704 if (c->u.pfd.pf != NULL)
7705 pfd_close(c->u.pfd.pf);
7706 logevent("Forwarded port closed");
7710 del234(ssh->channels, c);
7711 if (ssh->version == 2) {
7712 bufchain_clear(&c->v.v2.outbuffer);
7713 assert(c->v.v2.chanreq_head == NULL);
7718 * If that was the last channel left open, we might need to
7721 ssh_check_termination(ssh);
7724 static void ssh2_channel_check_close(struct ssh_channel *c)
7727 struct Packet *pktout;
7731 * If we've sent out our own CHANNEL_OPEN but not yet seen
7732 * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
7733 * it's too early to be sending close messages of any kind.
7738 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
7739 c->type == CHAN_ZOMBIE) &&
7740 !c->v.v2.chanreq_head &&
7741 !(c->closes & CLOSES_SENT_CLOSE)) {
7743 * We have both sent and received EOF (or the channel is a
7744 * zombie), and we have no outstanding channel requests, which
7745 * means the channel is in final wind-up. But we haven't sent
7746 * CLOSE, so let's do so now.
7748 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
7749 ssh2_pkt_adduint32(pktout, c->remoteid);
7750 ssh2_pkt_send(ssh, pktout);
7751 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
7754 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
7755 assert(c->v.v2.chanreq_head == NULL);
7757 * We have both sent and received CLOSE, which means we're
7758 * completely done with the channel.
7760 ssh_channel_destroy(c);
7764 static void ssh2_channel_got_eof(struct ssh_channel *c)
7766 if (c->closes & CLOSES_RCVD_EOF)
7767 return; /* already seen EOF */
7768 c->closes |= CLOSES_RCVD_EOF;
7770 if (c->type == CHAN_X11) {
7771 x11_send_eof(c->u.x11.xconn);
7772 } else if (c->type == CHAN_AGENT) {
7773 if (c->u.a.outstanding_requests == 0) {
7774 /* Manufacture an outgoing EOF in response to the incoming one. */
7775 sshfwd_write_eof(c);
7777 } else if (c->type == CHAN_SOCKDATA) {
7778 pfd_send_eof(c->u.pfd.pf);
7779 } else if (c->type == CHAN_MAINSESSION) {
7782 if (!ssh->sent_console_eof &&
7783 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
7785 * Either from_backend_eof told us that the front end
7786 * wants us to close the outgoing side of the connection
7787 * as soon as we see EOF from the far end, or else we've
7788 * unilaterally decided to do that because we've allocated
7789 * a remote pty and hence EOF isn't a particularly
7790 * meaningful concept.
7792 sshfwd_write_eof(c);
7794 ssh->sent_console_eof = TRUE;
7797 ssh2_channel_check_close(c);
7800 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
7802 struct ssh_channel *c;
7804 c = ssh2_channel_msg(ssh, pktin);
7807 if (c->type == CHAN_SHARING) {
7808 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7809 pktin->body, pktin->length);
7812 ssh2_channel_got_eof(c);
7815 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
7817 struct ssh_channel *c;
7819 c = ssh2_channel_msg(ssh, pktin);
7822 if (c->type == CHAN_SHARING) {
7823 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7824 pktin->body, pktin->length);
7829 * When we receive CLOSE on a channel, we assume it comes with an
7830 * implied EOF if we haven't seen EOF yet.
7832 ssh2_channel_got_eof(c);
7834 if (!(ssh->remote_bugs & BUG_SENDS_LATE_REQUEST_REPLY)) {
7836 * It also means we stop expecting to see replies to any
7837 * outstanding channel requests, so clean those up too.
7838 * (ssh_chanreq_init will enforce by assertion that we don't
7839 * subsequently put anything back on this list.)
7841 while (c->v.v2.chanreq_head) {
7842 struct outstanding_channel_request *ocr = c->v.v2.chanreq_head;
7843 ocr->handler(c, NULL, ocr->ctx);
7844 c->v.v2.chanreq_head = ocr->next;
7850 * And we also send an outgoing EOF, if we haven't already, on the
7851 * assumption that CLOSE is a pretty forceful announcement that
7852 * the remote side is doing away with the entire channel. (If it
7853 * had wanted to send us EOF and continue receiving data from us,
7854 * it would have just sent CHANNEL_EOF.)
7856 if (!(c->closes & CLOSES_SENT_EOF)) {
7858 * Make sure we don't read any more from whatever our local
7859 * data source is for this channel.
7862 case CHAN_MAINSESSION:
7863 ssh->send_ok = 0; /* stop trying to read from stdin */
7866 x11_override_throttle(c->u.x11.xconn, 1);
7869 pfd_override_throttle(c->u.pfd.pf, 1);
7874 * Abandon any buffered data we still wanted to send to this
7875 * channel. Receiving a CHANNEL_CLOSE is an indication that
7876 * the server really wants to get on and _destroy_ this
7877 * channel, and it isn't going to send us any further
7878 * WINDOW_ADJUSTs to permit us to send pending stuff.
7880 bufchain_clear(&c->v.v2.outbuffer);
7883 * Send outgoing EOF.
7885 sshfwd_write_eof(c);
7889 * Now process the actual close.
7891 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
7892 c->closes |= CLOSES_RCVD_CLOSE;
7893 ssh2_channel_check_close(c);
7897 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
7899 struct ssh_channel *c;
7901 c = ssh2_channel_msg(ssh, pktin);
7904 if (c->type == CHAN_SHARING) {
7905 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7906 pktin->body, pktin->length);
7909 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7910 c->remoteid = ssh_pkt_getuint32(pktin);
7911 c->halfopen = FALSE;
7912 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7913 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7915 if (c->type == CHAN_SOCKDATA_DORMANT) {
7916 c->type = CHAN_SOCKDATA;
7918 pfd_confirm(c->u.pfd.pf);
7919 } else if (c->type == CHAN_ZOMBIE) {
7921 * This case can occur if a local socket error occurred
7922 * between us sending out CHANNEL_OPEN and receiving
7923 * OPEN_CONFIRMATION. In this case, all we can do is
7924 * immediately initiate close proceedings now that we know the
7925 * server's id to put in the close message.
7927 ssh2_channel_check_close(c);
7930 * We never expect to receive OPEN_CONFIRMATION for any
7931 * *other* channel type (since only local-to-remote port
7932 * forwardings cause us to send CHANNEL_OPEN after the main
7933 * channel is live - all other auxiliary channel types are
7934 * initiated from the server end). It's safe to enforce this
7935 * by assertion rather than by ssh_disconnect, because the
7936 * real point is that we never constructed a half-open channel
7937 * structure in the first place with any type other than the
7940 assert(!"Funny channel type in ssh2_msg_channel_open_confirmation");
7944 ssh_channel_try_eof(c); /* in case we had a pending EOF */
7947 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
7949 static const char *const reasons[] = {
7950 "<unknown reason code>",
7951 "Administratively prohibited",
7953 "Unknown channel type",
7954 "Resource shortage",
7956 unsigned reason_code;
7957 char *reason_string;
7959 struct ssh_channel *c;
7961 c = ssh2_channel_msg(ssh, pktin);
7964 if (c->type == CHAN_SHARING) {
7965 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7966 pktin->body, pktin->length);
7969 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7971 if (c->type == CHAN_SOCKDATA_DORMANT) {
7972 reason_code = ssh_pkt_getuint32(pktin);
7973 if (reason_code >= lenof(reasons))
7974 reason_code = 0; /* ensure reasons[reason_code] in range */
7975 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
7976 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
7977 reasons[reason_code], reason_length, reason_string);
7979 pfd_close(c->u.pfd.pf);
7980 } else if (c->type == CHAN_ZOMBIE) {
7982 * This case can occur if a local socket error occurred
7983 * between us sending out CHANNEL_OPEN and receiving
7984 * OPEN_FAILURE. In this case, we need do nothing except allow
7985 * the code below to throw the half-open channel away.
7989 * We never expect to receive OPEN_FAILURE for any *other*
7990 * channel type (since only local-to-remote port forwardings
7991 * cause us to send CHANNEL_OPEN after the main channel is
7992 * live - all other auxiliary channel types are initiated from
7993 * the server end). It's safe to enforce this by assertion
7994 * rather than by ssh_disconnect, because the real point is
7995 * that we never constructed a half-open channel structure in
7996 * the first place with any type other than the above.
7998 assert(!"Funny channel type in ssh2_msg_channel_open_failure");
8001 del234(ssh->channels, c);
8005 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
8008 int typelen, want_reply;
8009 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
8010 struct ssh_channel *c;
8011 struct Packet *pktout;
8013 c = ssh2_channel_msg(ssh, pktin);
8016 if (c->type == CHAN_SHARING) {
8017 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8018 pktin->body, pktin->length);
8021 ssh_pkt_getstring(pktin, &type, &typelen);
8022 want_reply = ssh2_pkt_getbool(pktin);
8024 if (c->closes & CLOSES_SENT_CLOSE) {
8026 * We don't reply to channel requests after we've sent
8027 * CHANNEL_CLOSE for the channel, because our reply might
8028 * cross in the network with the other side's CHANNEL_CLOSE
8029 * and arrive after they have wound the channel up completely.
8035 * Having got the channel number, we now look at
8036 * the request type string to see if it's something
8039 if (c == ssh->mainchan) {
8041 * We recognise "exit-status" and "exit-signal" on
8042 * the primary channel.
8044 if (typelen == 11 &&
8045 !memcmp(type, "exit-status", 11)) {
8047 ssh->exitcode = ssh_pkt_getuint32(pktin);
8048 logeventf(ssh, "Server sent command exit status %d",
8050 reply = SSH2_MSG_CHANNEL_SUCCESS;
8052 } else if (typelen == 11 &&
8053 !memcmp(type, "exit-signal", 11)) {
8055 int is_plausible = TRUE, is_int = FALSE;
8056 char *fmt_sig = "", *fmt_msg = "";
8058 int msglen = 0, core = FALSE;
8059 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
8060 * provide an `int' for the signal, despite its
8061 * having been a `string' in the drafts of RFC 4254 since at
8062 * least 2001. (Fixed in session.c 1.147.) Try to
8063 * infer which we can safely parse it as. */
8065 unsigned char *p = pktin->body +
8067 long len = pktin->length - pktin->savedpos;
8068 unsigned long num = GET_32BIT(p); /* what is it? */
8069 /* If it's 0, it hardly matters; assume string */
8073 int maybe_int = FALSE, maybe_str = FALSE;
8074 #define CHECK_HYPOTHESIS(offset, result) \
8077 int q = toint(offset); \
8078 if (q >= 0 && q+4 <= len) { \
8079 q = toint(q + 4 + GET_32BIT(p+q)); \
8080 if (q >= 0 && q+4 <= len && \
8081 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
8086 CHECK_HYPOTHESIS(4+1, maybe_int);
8087 CHECK_HYPOTHESIS(4+num+1, maybe_str);
8088 #undef CHECK_HYPOTHESIS
8089 if (maybe_int && !maybe_str)
8091 else if (!maybe_int && maybe_str)
8094 /* Crikey. Either or neither. Panic. */
8095 is_plausible = FALSE;
8098 ssh->exitcode = 128; /* means `unknown signal' */
8101 /* Old non-standard OpenSSH. */
8102 int signum = ssh_pkt_getuint32(pktin);
8103 fmt_sig = dupprintf(" %d", signum);
8104 ssh->exitcode = 128 + signum;
8106 /* As per RFC 4254. */
8109 ssh_pkt_getstring(pktin, &sig, &siglen);
8110 /* Signal name isn't supposed to be blank, but
8111 * let's cope gracefully if it is. */
8113 fmt_sig = dupprintf(" \"%.*s\"",
8118 * Really hideous method of translating the
8119 * signal description back into a locally
8120 * meaningful number.
8125 #define TRANSLATE_SIGNAL(s) \
8126 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
8127 ssh->exitcode = 128 + SIG ## s
8129 TRANSLATE_SIGNAL(ABRT);
8132 TRANSLATE_SIGNAL(ALRM);
8135 TRANSLATE_SIGNAL(FPE);
8138 TRANSLATE_SIGNAL(HUP);
8141 TRANSLATE_SIGNAL(ILL);
8144 TRANSLATE_SIGNAL(INT);
8147 TRANSLATE_SIGNAL(KILL);
8150 TRANSLATE_SIGNAL(PIPE);
8153 TRANSLATE_SIGNAL(QUIT);
8156 TRANSLATE_SIGNAL(SEGV);
8159 TRANSLATE_SIGNAL(TERM);
8162 TRANSLATE_SIGNAL(USR1);
8165 TRANSLATE_SIGNAL(USR2);
8167 #undef TRANSLATE_SIGNAL
8169 ssh->exitcode = 128;
8171 core = ssh2_pkt_getbool(pktin);
8172 ssh_pkt_getstring(pktin, &msg, &msglen);
8174 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
8176 /* ignore lang tag */
8177 } /* else don't attempt to parse */
8178 logeventf(ssh, "Server exited on signal%s%s%s",
8179 fmt_sig, core ? " (core dumped)" : "",
8181 if (*fmt_sig) sfree(fmt_sig);
8182 if (*fmt_msg) sfree(fmt_msg);
8183 reply = SSH2_MSG_CHANNEL_SUCCESS;
8188 * This is a channel request we don't know
8189 * about, so we now either ignore the request
8190 * or respond with CHANNEL_FAILURE, depending
8193 reply = SSH2_MSG_CHANNEL_FAILURE;
8196 pktout = ssh2_pkt_init(reply);
8197 ssh2_pkt_adduint32(pktout, c->remoteid);
8198 ssh2_pkt_send(ssh, pktout);
8202 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
8205 int typelen, want_reply;
8206 struct Packet *pktout;
8208 ssh_pkt_getstring(pktin, &type, &typelen);
8209 want_reply = ssh2_pkt_getbool(pktin);
8212 * We currently don't support any global requests
8213 * at all, so we either ignore the request or
8214 * respond with REQUEST_FAILURE, depending on
8218 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
8219 ssh2_pkt_send(ssh, pktout);
8223 struct X11FakeAuth *ssh_sharing_add_x11_display(Ssh ssh, int authtype,
8227 struct X11FakeAuth *auth;
8230 * Make up a new set of fake X11 auth data, and add it to the tree
8231 * of currently valid ones with an indication of the sharing
8232 * context that it's relevant to.
8234 auth = x11_invent_fake_auth(ssh->x11authtree, authtype);
8235 auth->share_cs = share_cs;
8236 auth->share_chan = share_chan;
8241 void ssh_sharing_remove_x11_display(Ssh ssh, struct X11FakeAuth *auth)
8243 del234(ssh->x11authtree, auth);
8244 x11_free_fake_auth(auth);
8247 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
8255 struct ssh_channel *c;
8256 unsigned remid, winsize, pktsize;
8257 unsigned our_winsize_override = 0;
8258 struct Packet *pktout;
8260 ssh_pkt_getstring(pktin, &type, &typelen);
8261 c = snew(struct ssh_channel);
8264 remid = ssh_pkt_getuint32(pktin);
8265 winsize = ssh_pkt_getuint32(pktin);
8266 pktsize = ssh_pkt_getuint32(pktin);
8268 if (typelen == 3 && !memcmp(type, "x11", 3)) {
8271 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8272 addrstr = snewn(peeraddrlen+1, char);
8273 memcpy(addrstr, peeraddr, peeraddrlen);
8274 addrstr[peeraddrlen] = '\0';
8275 peerport = ssh_pkt_getuint32(pktin);
8277 logeventf(ssh, "Received X11 connect request from %s:%d",
8280 if (!ssh->X11_fwd_enabled && !ssh->connshare)
8281 error = "X11 forwarding is not enabled";
8283 c->u.x11.xconn = x11_init(ssh->x11authtree, c,
8286 c->u.x11.initial = TRUE;
8289 * If we are a connection-sharing upstream, then we should
8290 * initially present a very small window, adequate to take
8291 * the X11 initial authorisation packet but not much more.
8292 * Downstream will then present us a larger window (by
8293 * fiat of the connection-sharing protocol) and we can
8294 * guarantee to send a positive-valued WINDOW_ADJUST.
8297 our_winsize_override = 128;
8299 logevent("Opened X11 forward channel");
8303 } else if (typelen == 15 &&
8304 !memcmp(type, "forwarded-tcpip", 15)) {
8305 struct ssh_rportfwd pf, *realpf;
8308 ssh_pkt_getstring(pktin, &shost, &shostlen);/* skip address */
8309 pf.shost = dupprintf("%.*s", shostlen, shost);
8310 pf.sport = ssh_pkt_getuint32(pktin);
8311 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8312 peerport = ssh_pkt_getuint32(pktin);
8313 realpf = find234(ssh->rportfwds, &pf, NULL);
8314 logeventf(ssh, "Received remote port %s:%d open request "
8315 "from %s:%d", pf.shost, pf.sport, peeraddr, peerport);
8318 if (realpf == NULL) {
8319 error = "Remote port is not recognised";
8323 if (realpf->share_ctx) {
8325 * This port forwarding is on behalf of a
8326 * connection-sharing downstream, so abandon our own
8327 * channel-open procedure and just pass the message on
8330 share_got_pkt_from_server(realpf->share_ctx, pktin->type,
8331 pktin->body, pktin->length);
8336 err = pfd_connect(&c->u.pfd.pf, realpf->dhost, realpf->dport,
8337 c, ssh->conf, realpf->pfrec->addressfamily);
8338 logeventf(ssh, "Attempting to forward remote port to "
8339 "%s:%d", realpf->dhost, realpf->dport);
8341 logeventf(ssh, "Port open failed: %s", err);
8343 error = "Port open failed";
8345 logevent("Forwarded port opened successfully");
8346 c->type = CHAN_SOCKDATA;
8349 } else if (typelen == 22 &&
8350 !memcmp(type, "auth-agent@openssh.com", 22)) {
8351 if (!ssh->agentfwd_enabled)
8352 error = "Agent forwarding is not enabled";
8354 c->type = CHAN_AGENT; /* identify channel type */
8355 c->u.a.lensofar = 0;
8356 c->u.a.message = NULL;
8357 c->u.a.outstanding_requests = 0;
8360 error = "Unsupported channel type requested";
8363 c->remoteid = remid;
8364 c->halfopen = FALSE;
8366 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
8367 ssh2_pkt_adduint32(pktout, c->remoteid);
8368 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
8369 ssh2_pkt_addstring(pktout, error);
8370 ssh2_pkt_addstring(pktout, "en"); /* language tag */
8371 ssh2_pkt_send(ssh, pktout);
8372 logeventf(ssh, "Rejected channel open: %s", error);
8375 ssh2_channel_init(c);
8376 c->v.v2.remwindow = winsize;
8377 c->v.v2.remmaxpkt = pktsize;
8378 if (our_winsize_override) {
8379 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
8380 our_winsize_override;
8382 add234(ssh->channels, c);
8383 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
8384 ssh2_pkt_adduint32(pktout, c->remoteid);
8385 ssh2_pkt_adduint32(pktout, c->localid);
8386 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
8387 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8388 ssh2_pkt_send(ssh, pktout);
8392 void sshfwd_x11_sharing_handover(struct ssh_channel *c,
8393 void *share_cs, void *share_chan,
8394 const char *peer_addr, int peer_port,
8395 int endian, int protomajor, int protominor,
8396 const void *initial_data, int initial_len)
8399 * This function is called when we've just discovered that an X
8400 * forwarding channel on which we'd been handling the initial auth
8401 * ourselves turns out to be destined for a connection-sharing
8402 * downstream. So we turn the channel into a CHAN_SHARING, meaning
8403 * that we completely stop tracking windows and buffering data and
8404 * just pass more or less unmodified SSH messages back and forth.
8406 c->type = CHAN_SHARING;
8407 c->u.sharing.ctx = share_cs;
8408 share_setup_x11_channel(share_cs, share_chan,
8409 c->localid, c->remoteid, c->v.v2.remwindow,
8410 c->v.v2.remmaxpkt, c->v.v2.locwindow,
8411 peer_addr, peer_port, endian,
8412 protomajor, protominor,
8413 initial_data, initial_len);
8416 void sshfwd_x11_is_local(struct ssh_channel *c)
8419 * This function is called when we've just discovered that an X
8420 * forwarding channel is _not_ destined for a connection-sharing
8421 * downstream but we're going to handle it ourselves. We stop
8422 * presenting a cautiously small window and go into ordinary data
8425 c->u.x11.initial = FALSE;
8426 ssh2_set_window(c, ssh_is_simple(c->ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE);
8430 * Buffer banner messages for later display at some convenient point,
8431 * if we're going to display them.
8433 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
8435 /* Arbitrary limit to prevent unbounded inflation of buffer */
8436 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
8437 bufchain_size(&ssh->banner) <= 131072) {
8438 char *banner = NULL;
8440 ssh_pkt_getstring(pktin, &banner, &size);
8442 bufchain_add(&ssh->banner, banner, size);
8446 /* Helper function to deal with sending tty modes for "pty-req" */
8447 static void ssh2_send_ttymode(void *data, char *mode, char *val)
8449 struct Packet *pktout = (struct Packet *)data;
8451 unsigned int arg = 0;
8452 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
8453 if (i == lenof(ssh_ttymodes)) return;
8454 switch (ssh_ttymodes[i].type) {
8456 arg = ssh_tty_parse_specchar(val);
8459 arg = ssh_tty_parse_boolean(val);
8462 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
8463 ssh2_pkt_adduint32(pktout, arg);
8466 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
8469 struct ssh2_setup_x11_state {
8473 struct Packet *pktout;
8474 crStateP(ssh2_setup_x11_state, ctx);
8478 logevent("Requesting X11 forwarding");
8479 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
8481 ssh2_pkt_addbool(pktout, 0); /* many connections */
8482 ssh2_pkt_addstring(pktout, ssh->x11auth->protoname);
8483 ssh2_pkt_addstring(pktout, ssh->x11auth->datastring);
8484 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
8485 ssh2_pkt_send(ssh, pktout);
8487 /* Wait to be called back with either a response packet, or NULL
8488 * meaning clean up and free our data */
8492 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8493 logevent("X11 forwarding enabled");
8494 ssh->X11_fwd_enabled = TRUE;
8496 logevent("X11 forwarding refused");
8502 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
8505 struct ssh2_setup_agent_state {
8509 struct Packet *pktout;
8510 crStateP(ssh2_setup_agent_state, ctx);
8514 logevent("Requesting OpenSSH-style agent forwarding");
8515 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
8516 ssh2_setup_agent, s);
8517 ssh2_pkt_send(ssh, pktout);
8519 /* Wait to be called back with either a response packet, or NULL
8520 * meaning clean up and free our data */
8524 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8525 logevent("Agent forwarding enabled");
8526 ssh->agentfwd_enabled = TRUE;
8528 logevent("Agent forwarding refused");
8534 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
8537 struct ssh2_setup_pty_state {
8541 struct Packet *pktout;
8542 crStateP(ssh2_setup_pty_state, ctx);
8546 /* Unpick the terminal-speed string. */
8547 /* XXX perhaps we should allow no speeds to be sent. */
8548 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
8549 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
8550 /* Build the pty request. */
8551 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
8553 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
8554 ssh2_pkt_adduint32(pktout, ssh->term_width);
8555 ssh2_pkt_adduint32(pktout, ssh->term_height);
8556 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
8557 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
8558 ssh2_pkt_addstring_start(pktout);
8559 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
8560 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
8561 ssh2_pkt_adduint32(pktout, ssh->ispeed);
8562 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
8563 ssh2_pkt_adduint32(pktout, ssh->ospeed);
8564 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
8565 ssh2_pkt_send(ssh, pktout);
8566 ssh->state = SSH_STATE_INTERMED;
8568 /* Wait to be called back with either a response packet, or NULL
8569 * meaning clean up and free our data */
8573 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8574 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
8575 ssh->ospeed, ssh->ispeed);
8576 ssh->got_pty = TRUE;
8578 c_write_str(ssh, "Server refused to allocate pty\r\n");
8579 ssh->editing = ssh->echoing = 1;
8586 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
8589 struct ssh2_setup_env_state {
8591 int num_env, env_left, env_ok;
8594 struct Packet *pktout;
8595 crStateP(ssh2_setup_env_state, ctx);
8600 * Send environment variables.
8602 * Simplest thing here is to send all the requests at once, and
8603 * then wait for a whole bunch of successes or failures.
8609 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
8611 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
8612 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
8613 ssh2_pkt_addstring(pktout, key);
8614 ssh2_pkt_addstring(pktout, val);
8615 ssh2_pkt_send(ssh, pktout);
8620 logeventf(ssh, "Sent %d environment variables", s->num_env);
8625 s->env_left = s->num_env;
8627 while (s->env_left > 0) {
8628 /* Wait to be called back with either a response packet,
8629 * or NULL meaning clean up and free our data */
8631 if (!pktin) goto out;
8632 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
8637 if (s->env_ok == s->num_env) {
8638 logevent("All environment variables successfully set");
8639 } else if (s->env_ok == 0) {
8640 logevent("All environment variables refused");
8641 c_write_str(ssh, "Server refused to set environment variables\r\n");
8643 logeventf(ssh, "%d environment variables refused",
8644 s->num_env - s->env_ok);
8645 c_write_str(ssh, "Server refused to set all environment variables\r\n");
8653 * Handle the SSH-2 userauth and connection layers.
8655 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
8657 do_ssh2_authconn(ssh, NULL, 0, pktin);
8660 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
8664 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
8667 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
8668 struct Packet *pktin)
8670 struct do_ssh2_authconn_state {
8674 AUTH_TYPE_PUBLICKEY,
8675 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
8676 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
8678 AUTH_TYPE_GSSAPI, /* always QUIET */
8679 AUTH_TYPE_KEYBOARD_INTERACTIVE,
8680 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
8682 int done_service_req;
8683 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
8684 int tried_pubkey_config, done_agent;
8689 int kbd_inter_refused;
8690 int we_are_in, userauth_success;
8691 prompts_t *cur_prompt;
8696 void *publickey_blob;
8697 int publickey_bloblen;
8698 int publickey_encrypted;
8699 char *publickey_algorithm;
8700 char *publickey_comment;
8701 unsigned char agent_request[5], *agent_response, *agentp;
8702 int agent_responselen;
8703 unsigned char *pkblob_in_agent;
8705 char *pkblob, *alg, *commentp;
8706 int pklen, alglen, commentlen;
8707 int siglen, retlen, len;
8708 char *q, *agentreq, *ret;
8710 struct Packet *pktout;
8713 struct ssh_gss_library *gsslib;
8714 Ssh_gss_ctx gss_ctx;
8715 Ssh_gss_buf gss_buf;
8716 Ssh_gss_buf gss_rcvtok, gss_sndtok;
8717 Ssh_gss_name gss_srv_name;
8718 Ssh_gss_stat gss_stat;
8721 crState(do_ssh2_authconn_state);
8725 /* Register as a handler for all the messages this coroutine handles. */
8726 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
8727 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
8728 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
8729 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
8730 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
8731 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
8732 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
8733 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
8734 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
8735 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
8736 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
8737 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
8738 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
8739 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
8740 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
8741 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
8742 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
8743 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
8744 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
8745 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
8747 s->done_service_req = FALSE;
8748 s->we_are_in = s->userauth_success = FALSE;
8749 s->agent_response = NULL;
8751 s->tried_gssapi = FALSE;
8754 if (!ssh->bare_connection) {
8755 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
8757 * Request userauth protocol, and await a response to it.
8759 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8760 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
8761 ssh2_pkt_send(ssh, s->pktout);
8762 crWaitUntilV(pktin);
8763 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
8764 s->done_service_req = TRUE;
8766 if (!s->done_service_req) {
8768 * Request connection protocol directly, without authentication.
8770 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8771 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8772 ssh2_pkt_send(ssh, s->pktout);
8773 crWaitUntilV(pktin);
8774 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
8775 s->we_are_in = TRUE; /* no auth required */
8777 bombout(("Server refused service request"));
8782 s->we_are_in = TRUE;
8785 /* Arrange to be able to deal with any BANNERs that come in.
8786 * (We do this now as packets may come in during the next bit.) */
8787 bufchain_init(&ssh->banner);
8788 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
8789 ssh2_msg_userauth_banner;
8792 * Misc one-time setup for authentication.
8794 s->publickey_blob = NULL;
8795 if (!s->we_are_in) {
8798 * Load the public half of any configured public key file
8801 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
8802 if (!filename_is_null(s->keyfile)) {
8804 logeventf(ssh, "Reading private key file \"%.150s\"",
8805 filename_to_str(s->keyfile));
8806 keytype = key_type(s->keyfile);
8807 if (keytype == SSH_KEYTYPE_SSH2) {
8810 ssh2_userkey_loadpub(s->keyfile,
8811 &s->publickey_algorithm,
8812 &s->publickey_bloblen,
8813 &s->publickey_comment, &error);
8814 if (s->publickey_blob) {
8815 s->publickey_encrypted =
8816 ssh2_userkey_encrypted(s->keyfile, NULL);
8819 logeventf(ssh, "Unable to load private key (%s)",
8821 msgbuf = dupprintf("Unable to load private key file "
8822 "\"%.150s\" (%s)\r\n",
8823 filename_to_str(s->keyfile),
8825 c_write_str(ssh, msgbuf);
8830 logeventf(ssh, "Unable to use this key file (%s)",
8831 key_type_to_str(keytype));
8832 msgbuf = dupprintf("Unable to use key file \"%.150s\""
8834 filename_to_str(s->keyfile),
8835 key_type_to_str(keytype));
8836 c_write_str(ssh, msgbuf);
8838 s->publickey_blob = NULL;
8843 * Find out about any keys Pageant has (but if there's a
8844 * public key configured, filter out all others).
8847 s->agent_response = NULL;
8848 s->pkblob_in_agent = NULL;
8849 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
8853 logevent("Pageant is running. Requesting keys.");
8855 /* Request the keys held by the agent. */
8856 PUT_32BIT(s->agent_request, 1);
8857 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
8858 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
8859 ssh_agent_callback, ssh)) {
8863 bombout(("Unexpected data from server while"
8864 " waiting for agent response"));
8867 } while (pktin || inlen > 0);
8868 r = ssh->agent_response;
8869 s->agent_responselen = ssh->agent_response_len;
8871 s->agent_response = (unsigned char *) r;
8872 if (s->agent_response && s->agent_responselen >= 5 &&
8873 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
8876 p = s->agent_response + 5;
8877 s->nkeys = toint(GET_32BIT(p));
8880 * Vet the Pageant response to ensure that the key
8881 * count and blob lengths make sense.
8884 logeventf(ssh, "Pageant response contained a negative"
8885 " key count %d", s->nkeys);
8887 goto done_agent_query;
8889 unsigned char *q = p + 4;
8890 int lenleft = s->agent_responselen - 5 - 4;
8892 for (keyi = 0; keyi < s->nkeys; keyi++) {
8893 int bloblen, commentlen;
8895 logeventf(ssh, "Pageant response was truncated");
8897 goto done_agent_query;
8899 bloblen = toint(GET_32BIT(q));
8900 if (bloblen < 0 || bloblen > lenleft) {
8901 logeventf(ssh, "Pageant response was truncated");
8903 goto done_agent_query;
8905 lenleft -= 4 + bloblen;
8907 commentlen = toint(GET_32BIT(q));
8908 if (commentlen < 0 || commentlen > lenleft) {
8909 logeventf(ssh, "Pageant response was truncated");
8911 goto done_agent_query;
8913 lenleft -= 4 + commentlen;
8914 q += 4 + commentlen;
8919 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
8920 if (s->publickey_blob) {
8921 /* See if configured key is in agent. */
8922 for (keyi = 0; keyi < s->nkeys; keyi++) {
8923 s->pklen = toint(GET_32BIT(p));
8924 if (s->pklen == s->publickey_bloblen &&
8925 !memcmp(p+4, s->publickey_blob,
8926 s->publickey_bloblen)) {
8927 logeventf(ssh, "Pageant key #%d matches "
8928 "configured key file", keyi);
8930 s->pkblob_in_agent = p;
8934 p += toint(GET_32BIT(p)) + 4; /* comment */
8936 if (!s->pkblob_in_agent) {
8937 logevent("Configured key file not in Pageant");
8942 logevent("Failed to get reply from Pageant");
8950 * We repeat this whole loop, including the username prompt,
8951 * until we manage a successful authentication. If the user
8952 * types the wrong _password_, they can be sent back to the
8953 * beginning to try another username, if this is configured on.
8954 * (If they specify a username in the config, they are never
8955 * asked, even if they do give a wrong password.)
8957 * I think this best serves the needs of
8959 * - the people who have no configuration, no keys, and just
8960 * want to try repeated (username,password) pairs until they
8961 * type both correctly
8963 * - people who have keys and configuration but occasionally
8964 * need to fall back to passwords
8966 * - people with a key held in Pageant, who might not have
8967 * logged in to a particular machine before; so they want to
8968 * type a username, and then _either_ their key will be
8969 * accepted, _or_ they will type a password. If they mistype
8970 * the username they will want to be able to get back and
8973 s->got_username = FALSE;
8974 while (!s->we_are_in) {
8978 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
8980 * We got a username last time round this loop, and
8981 * with change_username turned off we don't try to get
8984 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
8985 int ret; /* need not be kept over crReturn */
8986 s->cur_prompt = new_prompts(ssh->frontend);
8987 s->cur_prompt->to_server = TRUE;
8988 s->cur_prompt->name = dupstr("SSH login name");
8989 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
8990 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8993 crWaitUntilV(!pktin);
8994 ret = get_userpass_input(s->cur_prompt, in, inlen);
8999 * get_userpass_input() failed to get a username.
9002 free_prompts(s->cur_prompt);
9003 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
9006 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
9007 free_prompts(s->cur_prompt);
9010 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
9011 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
9012 c_write_str(ssh, stuff);
9016 s->got_username = TRUE;
9019 * Send an authentication request using method "none": (a)
9020 * just in case it succeeds, and (b) so that we know what
9021 * authentication methods we can usefully try next.
9023 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9025 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9026 ssh2_pkt_addstring(s->pktout, ssh->username);
9027 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
9028 ssh2_pkt_addstring(s->pktout, "none"); /* method */
9029 ssh2_pkt_send(ssh, s->pktout);
9030 s->type = AUTH_TYPE_NONE;
9032 s->we_are_in = FALSE;
9034 s->tried_pubkey_config = FALSE;
9035 s->kbd_inter_refused = FALSE;
9037 /* Reset agent request state. */
9038 s->done_agent = FALSE;
9039 if (s->agent_response) {
9040 if (s->pkblob_in_agent) {
9041 s->agentp = s->pkblob_in_agent;
9043 s->agentp = s->agent_response + 5 + 4;
9049 char *methods = NULL;
9053 * Wait for the result of the last authentication request.
9056 crWaitUntilV(pktin);
9058 * Now is a convenient point to spew any banner material
9059 * that we've accumulated. (This should ensure that when
9060 * we exit the auth loop, we haven't any left to deal
9064 int size = bufchain_size(&ssh->banner);
9066 * Don't show the banner if we're operating in
9067 * non-verbose non-interactive mode. (It's probably
9068 * a script, which means nobody will read the
9069 * banner _anyway_, and moreover the printing of
9070 * the banner will screw up processing on the
9071 * output of (say) plink.)
9073 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
9074 char *banner = snewn(size, char);
9075 bufchain_fetch(&ssh->banner, banner, size);
9076 c_write_untrusted(ssh, banner, size);
9079 bufchain_clear(&ssh->banner);
9081 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
9082 logevent("Access granted");
9083 s->we_are_in = s->userauth_success = TRUE;
9087 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
9088 bombout(("Strange packet received during authentication: "
9089 "type %d", pktin->type));
9096 * OK, we're now sitting on a USERAUTH_FAILURE message, so
9097 * we can look at the string in it and know what we can
9098 * helpfully try next.
9100 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
9101 ssh_pkt_getstring(pktin, &methods, &methlen);
9102 if (!ssh2_pkt_getbool(pktin)) {
9104 * We have received an unequivocal Access
9105 * Denied. This can translate to a variety of
9106 * messages, or no message at all.
9108 * For forms of authentication which are attempted
9109 * implicitly, by which I mean without printing
9110 * anything in the window indicating that we're
9111 * trying them, we should never print 'Access
9114 * If we do print a message saying that we're
9115 * attempting some kind of authentication, it's OK
9116 * to print a followup message saying it failed -
9117 * but the message may sometimes be more specific
9118 * than simply 'Access denied'.
9120 * Additionally, if we'd just tried password
9121 * authentication, we should break out of this
9122 * whole loop so as to go back to the username
9123 * prompt (iff we're configured to allow
9124 * username change attempts).
9126 if (s->type == AUTH_TYPE_NONE) {
9128 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
9129 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
9130 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
9131 c_write_str(ssh, "Server refused our key\r\n");
9132 logevent("Server refused our key");
9133 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
9134 /* This _shouldn't_ happen except by a
9135 * protocol bug causing client and server to
9136 * disagree on what is a correct signature. */
9137 c_write_str(ssh, "Server refused public-key signature"
9138 " despite accepting key!\r\n");
9139 logevent("Server refused public-key signature"
9140 " despite accepting key!");
9141 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
9142 /* quiet, so no c_write */
9143 logevent("Server refused keyboard-interactive authentication");
9144 } else if (s->type==AUTH_TYPE_GSSAPI) {
9145 /* always quiet, so no c_write */
9146 /* also, the code down in the GSSAPI block has
9147 * already logged this in the Event Log */
9148 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
9149 logevent("Keyboard-interactive authentication failed");
9150 c_write_str(ssh, "Access denied\r\n");
9152 assert(s->type == AUTH_TYPE_PASSWORD);
9153 logevent("Password authentication failed");
9154 c_write_str(ssh, "Access denied\r\n");
9156 if (conf_get_int(ssh->conf, CONF_change_username)) {
9157 /* XXX perhaps we should allow
9158 * keyboard-interactive to do this too? */
9159 s->we_are_in = FALSE;
9164 c_write_str(ssh, "Further authentication required\r\n");
9165 logevent("Further authentication required");
9169 in_commasep_string("publickey", methods, methlen);
9171 in_commasep_string("password", methods, methlen);
9172 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
9173 in_commasep_string("keyboard-interactive", methods, methlen);
9176 ssh->gsslibs = ssh_gss_setup(ssh->conf);
9177 s->can_gssapi = conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
9178 in_commasep_string("gssapi-with-mic", methods, methlen) &&
9179 ssh->gsslibs->nlibraries > 0;
9183 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9185 if (s->can_pubkey && !s->done_agent && s->nkeys) {
9188 * Attempt public-key authentication using a key from Pageant.
9191 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9193 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
9195 /* Unpack key from agent response */
9196 s->pklen = toint(GET_32BIT(s->agentp));
9198 s->pkblob = (char *)s->agentp;
9199 s->agentp += s->pklen;
9200 s->alglen = toint(GET_32BIT(s->pkblob));
9201 s->alg = s->pkblob + 4;
9202 s->commentlen = toint(GET_32BIT(s->agentp));
9204 s->commentp = (char *)s->agentp;
9205 s->agentp += s->commentlen;
9206 /* s->agentp now points at next key, if any */
9208 /* See if server will accept it */
9209 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9210 ssh2_pkt_addstring(s->pktout, ssh->username);
9211 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9212 /* service requested */
9213 ssh2_pkt_addstring(s->pktout, "publickey");
9215 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
9216 ssh2_pkt_addstring_start(s->pktout);
9217 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9218 ssh2_pkt_addstring_start(s->pktout);
9219 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9220 ssh2_pkt_send(ssh, s->pktout);
9221 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
9223 crWaitUntilV(pktin);
9224 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9226 /* Offer of key refused. */
9233 if (flags & FLAG_VERBOSE) {
9234 c_write_str(ssh, "Authenticating with "
9236 c_write(ssh, s->commentp, s->commentlen);
9237 c_write_str(ssh, "\" from agent\r\n");
9241 * Server is willing to accept the key.
9242 * Construct a SIGN_REQUEST.
9244 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9245 ssh2_pkt_addstring(s->pktout, ssh->username);
9246 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9247 /* service requested */
9248 ssh2_pkt_addstring(s->pktout, "publickey");
9250 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
9251 ssh2_pkt_addstring_start(s->pktout);
9252 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9253 ssh2_pkt_addstring_start(s->pktout);
9254 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9256 /* Ask agent for signature. */
9257 s->siglen = s->pktout->length - 5 + 4 +
9258 ssh->v2_session_id_len;
9259 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9261 s->len = 1; /* message type */
9262 s->len += 4 + s->pklen; /* key blob */
9263 s->len += 4 + s->siglen; /* data to sign */
9264 s->len += 4; /* flags */
9265 s->agentreq = snewn(4 + s->len, char);
9266 PUT_32BIT(s->agentreq, s->len);
9267 s->q = s->agentreq + 4;
9268 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
9269 PUT_32BIT(s->q, s->pklen);
9271 memcpy(s->q, s->pkblob, s->pklen);
9273 PUT_32BIT(s->q, s->siglen);
9275 /* Now the data to be signed... */
9276 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9277 PUT_32BIT(s->q, ssh->v2_session_id_len);
9280 memcpy(s->q, ssh->v2_session_id,
9281 ssh->v2_session_id_len);
9282 s->q += ssh->v2_session_id_len;
9283 memcpy(s->q, s->pktout->data + 5,
9284 s->pktout->length - 5);
9285 s->q += s->pktout->length - 5;
9286 /* And finally the (zero) flags word. */
9288 if (!agent_query(s->agentreq, s->len + 4,
9290 ssh_agent_callback, ssh)) {
9294 bombout(("Unexpected data from server"
9295 " while waiting for agent"
9299 } while (pktin || inlen > 0);
9300 vret = ssh->agent_response;
9301 s->retlen = ssh->agent_response_len;
9306 if (s->retlen >= 9 &&
9307 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
9308 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
9309 logevent("Sending Pageant's response");
9310 ssh2_add_sigblob(ssh, s->pktout,
9311 s->pkblob, s->pklen,
9313 GET_32BIT(s->ret + 5));
9314 ssh2_pkt_send(ssh, s->pktout);
9315 s->type = AUTH_TYPE_PUBLICKEY;
9317 /* FIXME: less drastic response */
9318 bombout(("Pageant failed to answer challenge"));
9324 /* Do we have any keys left to try? */
9325 if (s->pkblob_in_agent) {
9326 s->done_agent = TRUE;
9327 s->tried_pubkey_config = TRUE;
9330 if (s->keyi >= s->nkeys)
9331 s->done_agent = TRUE;
9334 } else if (s->can_pubkey && s->publickey_blob &&
9335 !s->tried_pubkey_config) {
9337 struct ssh2_userkey *key; /* not live over crReturn */
9338 char *passphrase; /* not live over crReturn */
9340 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9342 s->tried_pubkey_config = TRUE;
9345 * Try the public key supplied in the configuration.
9347 * First, offer the public blob to see if the server is
9348 * willing to accept it.
9350 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9351 ssh2_pkt_addstring(s->pktout, ssh->username);
9352 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9353 /* service requested */
9354 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
9355 ssh2_pkt_addbool(s->pktout, FALSE);
9356 /* no signature included */
9357 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
9358 ssh2_pkt_addstring_start(s->pktout);
9359 ssh2_pkt_addstring_data(s->pktout,
9360 (char *)s->publickey_blob,
9361 s->publickey_bloblen);
9362 ssh2_pkt_send(ssh, s->pktout);
9363 logevent("Offered public key");
9365 crWaitUntilV(pktin);
9366 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9367 /* Key refused. Give up. */
9368 s->gotit = TRUE; /* reconsider message next loop */
9369 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
9370 continue; /* process this new message */
9372 logevent("Offer of public key accepted");
9375 * Actually attempt a serious authentication using
9378 if (flags & FLAG_VERBOSE) {
9379 c_write_str(ssh, "Authenticating with public key \"");
9380 c_write_str(ssh, s->publickey_comment);
9381 c_write_str(ssh, "\"\r\n");
9385 const char *error; /* not live over crReturn */
9386 if (s->publickey_encrypted) {
9388 * Get a passphrase from the user.
9390 int ret; /* need not be kept over crReturn */
9391 s->cur_prompt = new_prompts(ssh->frontend);
9392 s->cur_prompt->to_server = FALSE;
9393 s->cur_prompt->name = dupstr("SSH key passphrase");
9394 add_prompt(s->cur_prompt,
9395 dupprintf("Passphrase for key \"%.100s\": ",
9396 s->publickey_comment),
9398 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9401 crWaitUntilV(!pktin);
9402 ret = get_userpass_input(s->cur_prompt,
9407 /* Failed to get a passphrase. Terminate. */
9408 free_prompts(s->cur_prompt);
9409 ssh_disconnect(ssh, NULL,
9410 "Unable to authenticate",
9411 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9416 dupstr(s->cur_prompt->prompts[0]->result);
9417 free_prompts(s->cur_prompt);
9419 passphrase = NULL; /* no passphrase needed */
9423 * Try decrypting the key.
9425 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9426 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
9428 /* burn the evidence */
9429 smemclr(passphrase, strlen(passphrase));
9432 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
9434 (key == SSH2_WRONG_PASSPHRASE)) {
9435 c_write_str(ssh, "Wrong passphrase\r\n");
9437 /* and loop again */
9439 c_write_str(ssh, "Unable to load private key (");
9440 c_write_str(ssh, error);
9441 c_write_str(ssh, ")\r\n");
9443 break; /* try something else */
9449 unsigned char *pkblob, *sigblob, *sigdata;
9450 int pkblob_len, sigblob_len, sigdata_len;
9454 * We have loaded the private key and the server
9455 * has announced that it's willing to accept it.
9456 * Hallelujah. Generate a signature and send it.
9458 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9459 ssh2_pkt_addstring(s->pktout, ssh->username);
9460 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9461 /* service requested */
9462 ssh2_pkt_addstring(s->pktout, "publickey");
9464 ssh2_pkt_addbool(s->pktout, TRUE);
9465 /* signature follows */
9466 ssh2_pkt_addstring(s->pktout, key->alg->name);
9467 pkblob = key->alg->public_blob(key->data,
9469 ssh2_pkt_addstring_start(s->pktout);
9470 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
9474 * The data to be signed is:
9478 * followed by everything so far placed in the
9481 sigdata_len = s->pktout->length - 5 + 4 +
9482 ssh->v2_session_id_len;
9483 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9485 sigdata = snewn(sigdata_len, unsigned char);
9487 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9488 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
9491 memcpy(sigdata+p, ssh->v2_session_id,
9492 ssh->v2_session_id_len);
9493 p += ssh->v2_session_id_len;
9494 memcpy(sigdata+p, s->pktout->data + 5,
9495 s->pktout->length - 5);
9496 p += s->pktout->length - 5;
9497 assert(p == sigdata_len);
9498 sigblob = key->alg->sign(key->data, (char *)sigdata,
9499 sigdata_len, &sigblob_len);
9500 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
9501 sigblob, sigblob_len);
9506 ssh2_pkt_send(ssh, s->pktout);
9507 logevent("Sent public key signature");
9508 s->type = AUTH_TYPE_PUBLICKEY;
9509 key->alg->freekey(key->data);
9513 } else if (s->can_gssapi && !s->tried_gssapi) {
9515 /* GSSAPI Authentication */
9520 s->type = AUTH_TYPE_GSSAPI;
9521 s->tried_gssapi = TRUE;
9523 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
9526 * Pick the highest GSS library on the preference
9532 for (i = 0; i < ngsslibs; i++) {
9533 int want_id = conf_get_int_int(ssh->conf,
9534 CONF_ssh_gsslist, i);
9535 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
9536 if (ssh->gsslibs->libraries[j].id == want_id) {
9537 s->gsslib = &ssh->gsslibs->libraries[j];
9538 goto got_gsslib; /* double break */
9543 * We always expect to have found something in
9544 * the above loop: we only came here if there
9545 * was at least one viable GSS library, and the
9546 * preference list should always mention
9547 * everything and only change the order.
9552 if (s->gsslib->gsslogmsg)
9553 logevent(s->gsslib->gsslogmsg);
9555 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
9556 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9557 ssh2_pkt_addstring(s->pktout, ssh->username);
9558 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9559 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
9560 logevent("Attempting GSSAPI authentication");
9562 /* add mechanism info */
9563 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
9565 /* number of GSSAPI mechanisms */
9566 ssh2_pkt_adduint32(s->pktout,1);
9568 /* length of OID + 2 */
9569 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
9570 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
9573 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
9575 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
9577 ssh2_pkt_send(ssh, s->pktout);
9578 crWaitUntilV(pktin);
9579 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
9580 logevent("GSSAPI authentication request refused");
9584 /* check returned packet ... */
9586 ssh_pkt_getstring(pktin, &data, &len);
9587 s->gss_rcvtok.value = data;
9588 s->gss_rcvtok.length = len;
9589 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
9590 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
9591 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
9592 memcmp((char *)s->gss_rcvtok.value + 2,
9593 s->gss_buf.value,s->gss_buf.length) ) {
9594 logevent("GSSAPI authentication - wrong response from server");
9598 /* now start running */
9599 s->gss_stat = s->gsslib->import_name(s->gsslib,
9602 if (s->gss_stat != SSH_GSS_OK) {
9603 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
9604 logevent("GSSAPI import name failed - Bad service name");
9606 logevent("GSSAPI import name failed");
9610 /* fetch TGT into GSS engine */
9611 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
9613 if (s->gss_stat != SSH_GSS_OK) {
9614 logevent("GSSAPI authentication failed to get credentials");
9615 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9619 /* initial tokens are empty */
9620 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
9621 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
9623 /* now enter the loop */
9625 s->gss_stat = s->gsslib->init_sec_context
9629 conf_get_int(ssh->conf, CONF_gssapifwd),
9633 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
9634 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
9635 logevent("GSSAPI authentication initialisation failed");
9637 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
9638 &s->gss_buf) == SSH_GSS_OK) {
9639 logevent(s->gss_buf.value);
9640 sfree(s->gss_buf.value);
9645 logevent("GSSAPI authentication initialised");
9647 /* Client and server now exchange tokens until GSSAPI
9648 * no longer says CONTINUE_NEEDED */
9650 if (s->gss_sndtok.length != 0) {
9651 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
9652 ssh_pkt_addstring_start(s->pktout);
9653 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
9654 ssh2_pkt_send(ssh, s->pktout);
9655 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
9658 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
9659 crWaitUntilV(pktin);
9660 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
9661 logevent("GSSAPI authentication - bad server response");
9662 s->gss_stat = SSH_GSS_FAILURE;
9665 ssh_pkt_getstring(pktin, &data, &len);
9666 s->gss_rcvtok.value = data;
9667 s->gss_rcvtok.length = len;
9669 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
9671 if (s->gss_stat != SSH_GSS_OK) {
9672 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9673 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9676 logevent("GSSAPI authentication loop finished OK");
9678 /* Now send the MIC */
9680 s->pktout = ssh2_pkt_init(0);
9681 micoffset = s->pktout->length;
9682 ssh_pkt_addstring_start(s->pktout);
9683 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
9684 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
9685 ssh_pkt_addstring(s->pktout, ssh->username);
9686 ssh_pkt_addstring(s->pktout, "ssh-connection");
9687 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
9689 s->gss_buf.value = (char *)s->pktout->data + micoffset;
9690 s->gss_buf.length = s->pktout->length - micoffset;
9692 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
9693 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
9694 ssh_pkt_addstring_start(s->pktout);
9695 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
9696 ssh2_pkt_send(ssh, s->pktout);
9697 s->gsslib->free_mic(s->gsslib, &mic);
9701 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9702 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9705 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
9708 * Keyboard-interactive authentication.
9711 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
9713 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
9715 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9716 ssh2_pkt_addstring(s->pktout, ssh->username);
9717 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9718 /* service requested */
9719 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
9721 ssh2_pkt_addstring(s->pktout, ""); /* lang */
9722 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
9723 ssh2_pkt_send(ssh, s->pktout);
9725 logevent("Attempting keyboard-interactive authentication");
9727 crWaitUntilV(pktin);
9728 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
9729 /* Server is not willing to do keyboard-interactive
9730 * at all (or, bizarrely but legally, accepts the
9731 * user without actually issuing any prompts).
9732 * Give up on it entirely. */
9734 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
9735 s->kbd_inter_refused = TRUE; /* don't try it again */
9740 * Loop while the server continues to send INFO_REQUESTs.
9742 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
9744 char *name, *inst, *lang;
9745 int name_len, inst_len, lang_len;
9749 * We've got a fresh USERAUTH_INFO_REQUEST.
9750 * Get the preamble and start building a prompt.
9752 ssh_pkt_getstring(pktin, &name, &name_len);
9753 ssh_pkt_getstring(pktin, &inst, &inst_len);
9754 ssh_pkt_getstring(pktin, &lang, &lang_len);
9755 s->cur_prompt = new_prompts(ssh->frontend);
9756 s->cur_prompt->to_server = TRUE;
9759 * Get any prompt(s) from the packet.
9761 s->num_prompts = ssh_pkt_getuint32(pktin);
9762 for (i = 0; i < s->num_prompts; i++) {
9766 static char noprompt[] =
9767 "<server failed to send prompt>: ";
9769 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9770 echo = ssh2_pkt_getbool(pktin);
9773 prompt_len = lenof(noprompt)-1;
9775 add_prompt(s->cur_prompt,
9776 dupprintf("%.*s", prompt_len, prompt),
9781 /* FIXME: better prefix to distinguish from
9783 s->cur_prompt->name =
9784 dupprintf("SSH server: %.*s", name_len, name);
9785 s->cur_prompt->name_reqd = TRUE;
9787 s->cur_prompt->name =
9788 dupstr("SSH server authentication");
9789 s->cur_prompt->name_reqd = FALSE;
9791 /* We add a prefix to try to make it clear that a prompt
9792 * has come from the server.
9793 * FIXME: ugly to print "Using..." in prompt _every_
9794 * time round. Can this be done more subtly? */
9795 /* Special case: for reasons best known to themselves,
9796 * some servers send k-i requests with no prompts and
9797 * nothing to display. Keep quiet in this case. */
9798 if (s->num_prompts || name_len || inst_len) {
9799 s->cur_prompt->instruction =
9800 dupprintf("Using keyboard-interactive authentication.%s%.*s",
9801 inst_len ? "\n" : "", inst_len, inst);
9802 s->cur_prompt->instr_reqd = TRUE;
9804 s->cur_prompt->instr_reqd = FALSE;
9808 * Display any instructions, and get the user's
9812 int ret; /* not live over crReturn */
9813 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9816 crWaitUntilV(!pktin);
9817 ret = get_userpass_input(s->cur_prompt, in, inlen);
9822 * Failed to get responses. Terminate.
9824 free_prompts(s->cur_prompt);
9825 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9826 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9833 * Send the response(s) to the server.
9835 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
9836 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
9837 for (i=0; i < s->num_prompts; i++) {
9838 ssh2_pkt_addstring(s->pktout,
9839 s->cur_prompt->prompts[i]->result);
9841 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9844 * Free the prompts structure from this iteration.
9845 * If there's another, a new one will be allocated
9846 * when we return to the top of this while loop.
9848 free_prompts(s->cur_prompt);
9851 * Get the next packet in case it's another
9854 crWaitUntilV(pktin);
9859 * We should have SUCCESS or FAILURE now.
9863 } else if (s->can_passwd) {
9866 * Plain old password authentication.
9868 int ret; /* not live over crReturn */
9869 int changereq_first_time; /* not live over crReturn */
9871 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
9873 s->cur_prompt = new_prompts(ssh->frontend);
9874 s->cur_prompt->to_server = TRUE;
9875 s->cur_prompt->name = dupstr("SSH password");
9876 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
9881 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9884 crWaitUntilV(!pktin);
9885 ret = get_userpass_input(s->cur_prompt, in, inlen);
9890 * Failed to get responses. Terminate.
9892 free_prompts(s->cur_prompt);
9893 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9894 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9899 * Squirrel away the password. (We may need it later if
9900 * asked to change it.)
9902 s->password = dupstr(s->cur_prompt->prompts[0]->result);
9903 free_prompts(s->cur_prompt);
9906 * Send the password packet.
9908 * We pad out the password packet to 256 bytes to make
9909 * it harder for an attacker to find the length of the
9912 * Anyone using a password longer than 256 bytes
9913 * probably doesn't have much to worry about from
9914 * people who find out how long their password is!
9916 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9917 ssh2_pkt_addstring(s->pktout, ssh->username);
9918 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9919 /* service requested */
9920 ssh2_pkt_addstring(s->pktout, "password");
9921 ssh2_pkt_addbool(s->pktout, FALSE);
9922 ssh2_pkt_addstring(s->pktout, s->password);
9923 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9924 logevent("Sent password");
9925 s->type = AUTH_TYPE_PASSWORD;
9928 * Wait for next packet, in case it's a password change
9931 crWaitUntilV(pktin);
9932 changereq_first_time = TRUE;
9934 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
9937 * We're being asked for a new password
9938 * (perhaps not for the first time).
9939 * Loop until the server accepts it.
9942 int got_new = FALSE; /* not live over crReturn */
9943 char *prompt; /* not live over crReturn */
9944 int prompt_len; /* not live over crReturn */
9948 if (changereq_first_time)
9949 msg = "Server requested password change";
9951 msg = "Server rejected new password";
9953 c_write_str(ssh, msg);
9954 c_write_str(ssh, "\r\n");
9957 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9959 s->cur_prompt = new_prompts(ssh->frontend);
9960 s->cur_prompt->to_server = TRUE;
9961 s->cur_prompt->name = dupstr("New SSH password");
9962 s->cur_prompt->instruction =
9963 dupprintf("%.*s", prompt_len, prompt);
9964 s->cur_prompt->instr_reqd = TRUE;
9966 * There's no explicit requirement in the protocol
9967 * for the "old" passwords in the original and
9968 * password-change messages to be the same, and
9969 * apparently some Cisco kit supports password change
9970 * by the user entering a blank password originally
9971 * and the real password subsequently, so,
9972 * reluctantly, we prompt for the old password again.
9974 * (On the other hand, some servers don't even bother
9975 * to check this field.)
9977 add_prompt(s->cur_prompt,
9978 dupstr("Current password (blank for previously entered password): "),
9980 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
9982 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
9986 * Loop until the user manages to enter the same
9991 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9994 crWaitUntilV(!pktin);
9995 ret = get_userpass_input(s->cur_prompt, in, inlen);
10000 * Failed to get responses. Terminate.
10002 /* burn the evidence */
10003 free_prompts(s->cur_prompt);
10004 smemclr(s->password, strlen(s->password));
10005 sfree(s->password);
10006 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10007 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10013 * If the user specified a new original password
10014 * (IYSWIM), overwrite any previously specified
10016 * (A side effect is that the user doesn't have to
10017 * re-enter it if they louse up the new password.)
10019 if (s->cur_prompt->prompts[0]->result[0]) {
10020 smemclr(s->password, strlen(s->password));
10021 /* burn the evidence */
10022 sfree(s->password);
10024 dupstr(s->cur_prompt->prompts[0]->result);
10028 * Check the two new passwords match.
10030 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
10031 s->cur_prompt->prompts[2]->result)
10034 /* They don't. Silly user. */
10035 c_write_str(ssh, "Passwords do not match\r\n");
10040 * Send the new password (along with the old one).
10041 * (see above for padding rationale)
10043 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10044 ssh2_pkt_addstring(s->pktout, ssh->username);
10045 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10046 /* service requested */
10047 ssh2_pkt_addstring(s->pktout, "password");
10048 ssh2_pkt_addbool(s->pktout, TRUE);
10049 ssh2_pkt_addstring(s->pktout, s->password);
10050 ssh2_pkt_addstring(s->pktout,
10051 s->cur_prompt->prompts[1]->result);
10052 free_prompts(s->cur_prompt);
10053 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10054 logevent("Sent new password");
10057 * Now see what the server has to say about it.
10058 * (If it's CHANGEREQ again, it's not happy with the
10061 crWaitUntilV(pktin);
10062 changereq_first_time = FALSE;
10067 * We need to reexamine the current pktin at the top
10068 * of the loop. Either:
10069 * - we weren't asked to change password at all, in
10070 * which case it's a SUCCESS or FAILURE with the
10072 * - we sent a new password, and the server was
10073 * either OK with it (SUCCESS or FAILURE w/partial
10074 * success) or unhappy with the _old_ password
10075 * (FAILURE w/o partial success)
10076 * In any of these cases, we go back to the top of
10077 * the loop and start again.
10082 * We don't need the old password any more, in any
10083 * case. Burn the evidence.
10085 smemclr(s->password, strlen(s->password));
10086 sfree(s->password);
10089 char *str = dupprintf("No supported authentication methods available"
10090 " (server sent: %.*s)",
10093 ssh_disconnect(ssh, str,
10094 "No supported authentication methods available",
10095 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
10105 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
10107 /* Clear up various bits and pieces from authentication. */
10108 if (s->publickey_blob) {
10109 sfree(s->publickey_blob);
10110 sfree(s->publickey_comment);
10112 if (s->agent_response)
10113 sfree(s->agent_response);
10115 if (s->userauth_success && !ssh->bare_connection) {
10117 * We've just received USERAUTH_SUCCESS, and we haven't sent any
10118 * packets since. Signal the transport layer to consider enacting
10119 * delayed compression.
10121 * (Relying on we_are_in is not sufficient, as
10122 * draft-miller-secsh-compression-delayed is quite clear that it
10123 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
10124 * become set for other reasons.)
10126 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
10129 ssh->channels = newtree234(ssh_channelcmp);
10132 * Set up handlers for some connection protocol messages, so we
10133 * don't have to handle them repeatedly in this coroutine.
10135 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
10136 ssh2_msg_channel_window_adjust;
10137 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
10138 ssh2_msg_global_request;
10141 * Create the main session channel.
10143 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
10144 ssh->mainchan = NULL;
10146 ssh->mainchan = snew(struct ssh_channel);
10147 ssh->mainchan->ssh = ssh;
10148 ssh2_channel_init(ssh->mainchan);
10150 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
10152 * Just start a direct-tcpip channel and use it as the main
10155 ssh_send_port_open(ssh->mainchan,
10156 conf_get_str(ssh->conf, CONF_ssh_nc_host),
10157 conf_get_int(ssh->conf, CONF_ssh_nc_port),
10159 ssh->ncmode = TRUE;
10161 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
10162 logevent("Opening session as main channel");
10163 ssh2_pkt_send(ssh, s->pktout);
10164 ssh->ncmode = FALSE;
10166 crWaitUntilV(pktin);
10167 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
10168 bombout(("Server refused to open channel"));
10170 /* FIXME: error data comes back in FAILURE packet */
10172 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
10173 bombout(("Server's channel confirmation cited wrong channel"));
10176 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
10177 ssh->mainchan->halfopen = FALSE;
10178 ssh->mainchan->type = CHAN_MAINSESSION;
10179 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
10180 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
10181 add234(ssh->channels, ssh->mainchan);
10182 update_specials_menu(ssh->frontend);
10183 logevent("Opened main channel");
10187 * Now we have a channel, make dispatch table entries for
10188 * general channel-based messages.
10190 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
10191 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
10192 ssh2_msg_channel_data;
10193 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
10194 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
10195 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
10196 ssh2_msg_channel_open_confirmation;
10197 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
10198 ssh2_msg_channel_open_failure;
10199 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
10200 ssh2_msg_channel_request;
10201 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
10202 ssh2_msg_channel_open;
10203 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
10204 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
10207 * Now the connection protocol is properly up and running, with
10208 * all those dispatch table entries, so it's safe to let
10209 * downstreams start trying to open extra channels through us.
10211 if (ssh->connshare)
10212 share_activate(ssh->connshare, ssh->v_s);
10214 if (ssh->mainchan && ssh_is_simple(ssh)) {
10216 * This message indicates to the server that we promise
10217 * not to try to run any other channel in parallel with
10218 * this one, so it's safe for it to advertise a very large
10219 * window and leave the flow control to TCP.
10221 s->pktout = ssh2_chanreq_init(ssh->mainchan,
10222 "simple@putty.projects.tartarus.org",
10224 ssh2_pkt_send(ssh, s->pktout);
10228 * Enable port forwardings.
10230 ssh_setup_portfwd(ssh, ssh->conf);
10232 if (ssh->mainchan && !ssh->ncmode) {
10234 * Send the CHANNEL_REQUESTS for the main session channel.
10235 * Each one is handled by its own little asynchronous
10239 /* Potentially enable X11 forwarding. */
10240 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
10242 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
10244 if (!ssh->x11disp) {
10245 /* FIXME: return an error message from x11_setup_display */
10246 logevent("X11 forwarding not enabled: unable to"
10247 " initialise X display");
10249 ssh->x11auth = x11_invent_fake_auth
10250 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
10251 ssh->x11auth->disp = ssh->x11disp;
10253 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
10257 /* Potentially enable agent forwarding. */
10258 if (ssh_agent_forwarding_permitted(ssh))
10259 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
10261 /* Now allocate a pty for the session. */
10262 if (!conf_get_int(ssh->conf, CONF_nopty))
10263 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
10265 /* Send environment variables. */
10266 ssh2_setup_env(ssh->mainchan, NULL, NULL);
10269 * Start a shell or a remote command. We may have to attempt
10270 * this twice if the config data has provided a second choice
10277 if (ssh->fallback_cmd) {
10278 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
10279 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
10281 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
10282 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
10286 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
10287 ssh2_response_authconn, NULL);
10288 ssh2_pkt_addstring(s->pktout, cmd);
10290 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
10291 ssh2_response_authconn, NULL);
10292 ssh2_pkt_addstring(s->pktout, cmd);
10294 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
10295 ssh2_response_authconn, NULL);
10297 ssh2_pkt_send(ssh, s->pktout);
10299 crWaitUntilV(pktin);
10301 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
10302 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
10303 bombout(("Unexpected response to shell/command request:"
10304 " packet type %d", pktin->type));
10308 * We failed to start the command. If this is the
10309 * fallback command, we really are finished; if it's
10310 * not, and if the fallback command exists, try falling
10311 * back to it before complaining.
10313 if (!ssh->fallback_cmd &&
10314 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
10315 logevent("Primary command failed; attempting fallback");
10316 ssh->fallback_cmd = TRUE;
10319 bombout(("Server refused to start a shell/command"));
10322 logevent("Started a shell/command");
10327 ssh->editing = ssh->echoing = TRUE;
10330 ssh->state = SSH_STATE_SESSION;
10331 if (ssh->size_needed)
10332 ssh_size(ssh, ssh->term_width, ssh->term_height);
10333 if (ssh->eof_needed)
10334 ssh_special(ssh, TS_EOF);
10340 ldisc_echoedit_update(ssh->ldisc); /* cause ldisc to notice changes */
10345 s->try_send = FALSE;
10349 * _All_ the connection-layer packets we expect to
10350 * receive are now handled by the dispatch table.
10351 * Anything that reaches here must be bogus.
10354 bombout(("Strange packet received: type %d", pktin->type));
10356 } else if (ssh->mainchan) {
10358 * We have spare data. Add it to the channel buffer.
10360 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
10361 s->try_send = TRUE;
10365 struct ssh_channel *c;
10367 * Try to send data on all channels if we can.
10369 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
10370 ssh2_try_send_and_unthrottle(ssh, c);
10378 * Handlers for SSH-2 messages that might arrive at any moment.
10380 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
10382 /* log reason code in disconnect message */
10384 int reason, msglen;
10386 reason = ssh_pkt_getuint32(pktin);
10387 ssh_pkt_getstring(pktin, &msg, &msglen);
10389 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
10390 buf = dupprintf("Received disconnect message (%s)",
10391 ssh2_disconnect_reasons[reason]);
10393 buf = dupprintf("Received disconnect message (unknown"
10394 " type %d)", reason);
10398 buf = dupprintf("Disconnection message text: %.*s",
10401 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
10403 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
10404 ssh2_disconnect_reasons[reason] : "unknown",
10409 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
10411 /* log the debug message */
10415 /* XXX maybe we should actually take notice of the return value */
10416 ssh2_pkt_getbool(pktin);
10417 ssh_pkt_getstring(pktin, &msg, &msglen);
10419 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
10422 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
10424 do_ssh2_transport(ssh, NULL, 0, pktin);
10428 * Called if we receive a packet that isn't allowed by the protocol.
10429 * This only applies to packets whose meaning PuTTY understands.
10430 * Entirely unknown packets are handled below.
10432 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
10434 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
10435 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
10437 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
10441 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
10443 struct Packet *pktout;
10444 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
10445 ssh2_pkt_adduint32(pktout, pktin->sequence);
10447 * UNIMPLEMENTED messages MUST appear in the same order as the
10448 * messages they respond to. Hence, never queue them.
10450 ssh2_pkt_send_noqueue(ssh, pktout);
10454 * Handle the top-level SSH-2 protocol.
10456 static void ssh2_protocol_setup(Ssh ssh)
10461 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10463 for (i = 0; i < 256; i++)
10464 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10467 * Initially, we only accept transport messages (and a few generic
10468 * ones). do_ssh2_authconn will add more when it starts.
10469 * Messages that are understood but not currently acceptable go to
10470 * ssh2_msg_unexpected.
10472 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10473 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
10474 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
10475 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
10476 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
10477 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
10478 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
10479 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
10480 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
10481 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
10482 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
10483 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
10484 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
10485 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
10486 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
10487 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
10488 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
10489 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
10490 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
10491 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10492 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10493 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10494 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10495 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10496 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10497 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10498 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10499 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10500 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10501 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10502 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10503 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10504 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10507 * These messages have a special handler from the start.
10509 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10510 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
10511 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10514 static void ssh2_bare_connection_protocol_setup(Ssh ssh)
10519 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10521 for (i = 0; i < 256; i++)
10522 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10525 * Initially, we set all ssh-connection messages to 'unexpected';
10526 * do_ssh2_authconn will fill things in properly. We also handle a
10527 * couple of messages from the transport protocol which aren't
10528 * related to key exchange (UNIMPLEMENTED, IGNORE, DEBUG,
10531 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10532 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10533 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10534 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10535 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10536 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10537 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10538 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10539 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10540 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10541 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10542 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10543 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10544 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10546 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10549 * These messages have a special handler from the start.
10551 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10552 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore;
10553 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10556 static void ssh2_timer(void *ctx, unsigned long now)
10558 Ssh ssh = (Ssh)ctx;
10560 if (ssh->state == SSH_STATE_CLOSED)
10563 if (!ssh->kex_in_progress && !ssh->bare_connection &&
10564 conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
10565 now == ssh->next_rekey) {
10566 do_ssh2_transport(ssh, "timeout", -1, NULL);
10570 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
10571 struct Packet *pktin)
10573 unsigned char *in = (unsigned char *)vin;
10574 if (ssh->state == SSH_STATE_CLOSED)
10578 ssh->incoming_data_size += pktin->encrypted_len;
10579 if (!ssh->kex_in_progress &&
10580 ssh->max_data_size != 0 &&
10581 ssh->incoming_data_size > ssh->max_data_size)
10582 do_ssh2_transport(ssh, "too much data received", -1, NULL);
10586 ssh->packet_dispatch[pktin->type](ssh, pktin);
10587 else if (!ssh->protocol_initial_phase_done)
10588 do_ssh2_transport(ssh, in, inlen, pktin);
10590 do_ssh2_authconn(ssh, in, inlen, pktin);
10593 static void ssh2_bare_connection_protocol(Ssh ssh, void *vin, int inlen,
10594 struct Packet *pktin)
10596 unsigned char *in = (unsigned char *)vin;
10597 if (ssh->state == SSH_STATE_CLOSED)
10601 ssh->packet_dispatch[pktin->type](ssh, pktin);
10603 do_ssh2_authconn(ssh, in, inlen, pktin);
10606 static void ssh_cache_conf_values(Ssh ssh)
10608 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
10612 * Called to set up the connection.
10614 * Returns an error message, or NULL on success.
10616 static const char *ssh_init(void *frontend_handle, void **backend_handle,
10617 Conf *conf, char *host, int port, char **realhost,
10618 int nodelay, int keepalive)
10623 ssh = snew(struct ssh_tag);
10624 ssh->conf = conf_copy(conf);
10625 ssh_cache_conf_values(ssh);
10626 ssh->version = 0; /* when not ready yet */
10628 ssh->cipher = NULL;
10629 ssh->v1_cipher_ctx = NULL;
10630 ssh->crcda_ctx = NULL;
10631 ssh->cscipher = NULL;
10632 ssh->cs_cipher_ctx = NULL;
10633 ssh->sccipher = NULL;
10634 ssh->sc_cipher_ctx = NULL;
10636 ssh->cs_mac_ctx = NULL;
10638 ssh->sc_mac_ctx = NULL;
10639 ssh->cscomp = NULL;
10640 ssh->cs_comp_ctx = NULL;
10641 ssh->sccomp = NULL;
10642 ssh->sc_comp_ctx = NULL;
10644 ssh->kex_ctx = NULL;
10645 ssh->hostkey = NULL;
10646 ssh->hostkey_str = NULL;
10647 ssh->exitcode = -1;
10648 ssh->close_expected = FALSE;
10649 ssh->clean_exit = FALSE;
10650 ssh->state = SSH_STATE_PREPACKET;
10651 ssh->size_needed = FALSE;
10652 ssh->eof_needed = FALSE;
10654 ssh->logctx = NULL;
10655 ssh->deferred_send_data = NULL;
10656 ssh->deferred_len = 0;
10657 ssh->deferred_size = 0;
10658 ssh->fallback_cmd = 0;
10659 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
10660 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
10661 ssh->x11disp = NULL;
10662 ssh->x11auth = NULL;
10663 ssh->x11authtree = newtree234(x11_authcmp);
10664 ssh->v1_compressing = FALSE;
10665 ssh->v2_outgoing_sequence = 0;
10666 ssh->ssh1_rdpkt_crstate = 0;
10667 ssh->ssh2_rdpkt_crstate = 0;
10668 ssh->ssh2_bare_rdpkt_crstate = 0;
10669 ssh->ssh_gotdata_crstate = 0;
10670 ssh->do_ssh1_connection_crstate = 0;
10671 ssh->do_ssh_init_state = NULL;
10672 ssh->do_ssh_connection_init_state = NULL;
10673 ssh->do_ssh1_login_state = NULL;
10674 ssh->do_ssh2_transport_state = NULL;
10675 ssh->do_ssh2_authconn_state = NULL;
10678 ssh->mainchan = NULL;
10679 ssh->throttled_all = 0;
10680 ssh->v1_stdout_throttling = 0;
10682 ssh->queuelen = ssh->queuesize = 0;
10683 ssh->queueing = FALSE;
10684 ssh->qhead = ssh->qtail = NULL;
10685 ssh->deferred_rekey_reason = NULL;
10686 bufchain_init(&ssh->queued_incoming_data);
10687 ssh->frozen = FALSE;
10688 ssh->username = NULL;
10689 ssh->sent_console_eof = FALSE;
10690 ssh->got_pty = FALSE;
10691 ssh->bare_connection = FALSE;
10692 ssh->X11_fwd_enabled = FALSE;
10693 ssh->connshare = NULL;
10694 ssh->attempting_connshare = FALSE;
10696 *backend_handle = ssh;
10699 if (crypto_startup() == 0)
10700 return "Microsoft high encryption pack not installed!";
10703 ssh->frontend = frontend_handle;
10704 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
10705 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
10707 ssh->channels = NULL;
10708 ssh->rportfwds = NULL;
10709 ssh->portfwds = NULL;
10714 ssh->conn_throttle_count = 0;
10715 ssh->overall_bufsize = 0;
10716 ssh->fallback_cmd = 0;
10718 ssh->protocol = NULL;
10720 ssh->protocol_initial_phase_done = FALSE;
10722 ssh->pinger = NULL;
10724 ssh->incoming_data_size = ssh->outgoing_data_size =
10725 ssh->deferred_data_size = 0L;
10726 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10727 CONF_ssh_rekey_data));
10728 ssh->kex_in_progress = FALSE;
10731 ssh->gsslibs = NULL;
10734 random_ref(); /* do this now - may be needed by sharing setup code */
10736 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
10745 static void ssh_free(void *handle)
10747 Ssh ssh = (Ssh) handle;
10748 struct ssh_channel *c;
10749 struct ssh_rportfwd *pf;
10750 struct X11FakeAuth *auth;
10752 if (ssh->v1_cipher_ctx)
10753 ssh->cipher->free_context(ssh->v1_cipher_ctx);
10754 if (ssh->cs_cipher_ctx)
10755 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
10756 if (ssh->sc_cipher_ctx)
10757 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
10758 if (ssh->cs_mac_ctx)
10759 ssh->csmac->free_context(ssh->cs_mac_ctx);
10760 if (ssh->sc_mac_ctx)
10761 ssh->scmac->free_context(ssh->sc_mac_ctx);
10762 if (ssh->cs_comp_ctx) {
10764 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
10766 zlib_compress_cleanup(ssh->cs_comp_ctx);
10768 if (ssh->sc_comp_ctx) {
10770 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
10772 zlib_decompress_cleanup(ssh->sc_comp_ctx);
10775 dh_cleanup(ssh->kex_ctx);
10776 sfree(ssh->savedhost);
10778 while (ssh->queuelen-- > 0)
10779 ssh_free_packet(ssh->queue[ssh->queuelen]);
10782 while (ssh->qhead) {
10783 struct queued_handler *qh = ssh->qhead;
10784 ssh->qhead = qh->next;
10787 ssh->qhead = ssh->qtail = NULL;
10789 if (ssh->channels) {
10790 while ((c = delpos234(ssh->channels, 0)) != NULL) {
10793 if (c->u.x11.xconn != NULL)
10794 x11_close(c->u.x11.xconn);
10796 case CHAN_SOCKDATA:
10797 case CHAN_SOCKDATA_DORMANT:
10798 if (c->u.pfd.pf != NULL)
10799 pfd_close(c->u.pfd.pf);
10802 if (ssh->version == 2) {
10803 struct outstanding_channel_request *ocr, *nocr;
10804 ocr = c->v.v2.chanreq_head;
10806 ocr->handler(c, NULL, ocr->ctx);
10811 bufchain_clear(&c->v.v2.outbuffer);
10815 freetree234(ssh->channels);
10816 ssh->channels = NULL;
10819 if (ssh->connshare)
10820 sharestate_free(ssh->connshare);
10822 if (ssh->rportfwds) {
10823 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
10825 freetree234(ssh->rportfwds);
10826 ssh->rportfwds = NULL;
10828 sfree(ssh->deferred_send_data);
10830 x11_free_display(ssh->x11disp);
10831 while ((auth = delpos234(ssh->x11authtree, 0)) != NULL)
10832 x11_free_fake_auth(auth);
10833 freetree234(ssh->x11authtree);
10834 sfree(ssh->do_ssh_init_state);
10835 sfree(ssh->do_ssh1_login_state);
10836 sfree(ssh->do_ssh2_transport_state);
10837 sfree(ssh->do_ssh2_authconn_state);
10840 sfree(ssh->fullhostname);
10841 sfree(ssh->hostkey_str);
10842 if (ssh->crcda_ctx) {
10843 crcda_free_context(ssh->crcda_ctx);
10844 ssh->crcda_ctx = NULL;
10847 ssh_do_close(ssh, TRUE);
10848 expire_timer_context(ssh);
10850 pinger_free(ssh->pinger);
10851 bufchain_clear(&ssh->queued_incoming_data);
10852 sfree(ssh->username);
10853 conf_free(ssh->conf);
10856 ssh_gss_cleanup(ssh->gsslibs);
10864 * Reconfigure the SSH backend.
10866 static void ssh_reconfig(void *handle, Conf *conf)
10868 Ssh ssh = (Ssh) handle;
10869 char *rekeying = NULL, rekey_mandatory = FALSE;
10870 unsigned long old_max_data_size;
10873 pinger_reconfig(ssh->pinger, ssh->conf, conf);
10875 ssh_setup_portfwd(ssh, conf);
10877 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
10878 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
10880 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
10881 unsigned long now = GETTICKCOUNT();
10883 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
10884 rekeying = "timeout shortened";
10886 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
10890 old_max_data_size = ssh->max_data_size;
10891 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10892 CONF_ssh_rekey_data));
10893 if (old_max_data_size != ssh->max_data_size &&
10894 ssh->max_data_size != 0) {
10895 if (ssh->outgoing_data_size > ssh->max_data_size ||
10896 ssh->incoming_data_size > ssh->max_data_size)
10897 rekeying = "data limit lowered";
10900 if (conf_get_int(ssh->conf, CONF_compression) !=
10901 conf_get_int(conf, CONF_compression)) {
10902 rekeying = "compression setting changed";
10903 rekey_mandatory = TRUE;
10906 for (i = 0; i < CIPHER_MAX; i++)
10907 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
10908 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
10909 rekeying = "cipher settings changed";
10910 rekey_mandatory = TRUE;
10912 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
10913 conf_get_int(conf, CONF_ssh2_des_cbc)) {
10914 rekeying = "cipher settings changed";
10915 rekey_mandatory = TRUE;
10918 conf_free(ssh->conf);
10919 ssh->conf = conf_copy(conf);
10920 ssh_cache_conf_values(ssh);
10922 if (!ssh->bare_connection && rekeying) {
10923 if (!ssh->kex_in_progress) {
10924 do_ssh2_transport(ssh, rekeying, -1, NULL);
10925 } else if (rekey_mandatory) {
10926 ssh->deferred_rekey_reason = rekeying;
10932 * Called to send data down the SSH connection.
10934 static int ssh_send(void *handle, char *buf, int len)
10936 Ssh ssh = (Ssh) handle;
10938 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10941 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
10943 return ssh_sendbuffer(ssh);
10947 * Called to query the current amount of buffered stdin data.
10949 static int ssh_sendbuffer(void *handle)
10951 Ssh ssh = (Ssh) handle;
10952 int override_value;
10954 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10958 * If the SSH socket itself has backed up, add the total backup
10959 * size on that to any individual buffer on the stdin channel.
10961 override_value = 0;
10962 if (ssh->throttled_all)
10963 override_value = ssh->overall_bufsize;
10965 if (ssh->version == 1) {
10966 return override_value;
10967 } else if (ssh->version == 2) {
10968 if (!ssh->mainchan)
10969 return override_value;
10971 return (override_value +
10972 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
10979 * Called to set the size of the window from SSH's POV.
10981 static void ssh_size(void *handle, int width, int height)
10983 Ssh ssh = (Ssh) handle;
10984 struct Packet *pktout;
10986 ssh->term_width = width;
10987 ssh->term_height = height;
10989 switch (ssh->state) {
10990 case SSH_STATE_BEFORE_SIZE:
10991 case SSH_STATE_PREPACKET:
10992 case SSH_STATE_CLOSED:
10993 break; /* do nothing */
10994 case SSH_STATE_INTERMED:
10995 ssh->size_needed = TRUE; /* buffer for later */
10997 case SSH_STATE_SESSION:
10998 if (!conf_get_int(ssh->conf, CONF_nopty)) {
10999 if (ssh->version == 1) {
11000 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
11001 PKT_INT, ssh->term_height,
11002 PKT_INT, ssh->term_width,
11003 PKT_INT, 0, PKT_INT, 0, PKT_END);
11004 } else if (ssh->mainchan) {
11005 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
11007 ssh2_pkt_adduint32(pktout, ssh->term_width);
11008 ssh2_pkt_adduint32(pktout, ssh->term_height);
11009 ssh2_pkt_adduint32(pktout, 0);
11010 ssh2_pkt_adduint32(pktout, 0);
11011 ssh2_pkt_send(ssh, pktout);
11019 * Return a list of the special codes that make sense in this
11022 static const struct telnet_special *ssh_get_specials(void *handle)
11024 static const struct telnet_special ssh1_ignore_special[] = {
11025 {"IGNORE message", TS_NOP}
11027 static const struct telnet_special ssh2_ignore_special[] = {
11028 {"IGNORE message", TS_NOP},
11030 static const struct telnet_special ssh2_rekey_special[] = {
11031 {"Repeat key exchange", TS_REKEY},
11033 static const struct telnet_special ssh2_session_specials[] = {
11036 /* These are the signal names defined by RFC 4254.
11037 * They include all the ISO C signals, but are a subset of the POSIX
11038 * required signals. */
11039 {"SIGINT (Interrupt)", TS_SIGINT},
11040 {"SIGTERM (Terminate)", TS_SIGTERM},
11041 {"SIGKILL (Kill)", TS_SIGKILL},
11042 {"SIGQUIT (Quit)", TS_SIGQUIT},
11043 {"SIGHUP (Hangup)", TS_SIGHUP},
11044 {"More signals", TS_SUBMENU},
11045 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
11046 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
11047 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
11048 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
11049 {NULL, TS_EXITMENU}
11051 static const struct telnet_special specials_end[] = {
11052 {NULL, TS_EXITMENU}
11054 /* XXX review this length for any changes: */
11055 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
11056 lenof(ssh2_rekey_special) +
11057 lenof(ssh2_session_specials) +
11058 lenof(specials_end)];
11059 Ssh ssh = (Ssh) handle;
11061 #define ADD_SPECIALS(name) \
11063 assert((i + lenof(name)) <= lenof(ssh_specials)); \
11064 memcpy(&ssh_specials[i], name, sizeof name); \
11065 i += lenof(name); \
11068 if (ssh->version == 1) {
11069 /* Don't bother offering IGNORE if we've decided the remote
11070 * won't cope with it, since we wouldn't bother sending it if
11072 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11073 ADD_SPECIALS(ssh1_ignore_special);
11074 } else if (ssh->version == 2) {
11075 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
11076 ADD_SPECIALS(ssh2_ignore_special);
11077 if (!(ssh->remote_bugs & BUG_SSH2_REKEY) && !ssh->bare_connection)
11078 ADD_SPECIALS(ssh2_rekey_special);
11080 ADD_SPECIALS(ssh2_session_specials);
11081 } /* else we're not ready yet */
11084 ADD_SPECIALS(specials_end);
11085 return ssh_specials;
11089 #undef ADD_SPECIALS
11093 * Send special codes. TS_EOF is useful for `plink', so you
11094 * can send an EOF and collect resulting output (e.g. `plink
11097 static void ssh_special(void *handle, Telnet_Special code)
11099 Ssh ssh = (Ssh) handle;
11100 struct Packet *pktout;
11102 if (code == TS_EOF) {
11103 if (ssh->state != SSH_STATE_SESSION) {
11105 * Buffer the EOF in case we are pre-SESSION, so we can
11106 * send it as soon as we reach SESSION.
11108 if (code == TS_EOF)
11109 ssh->eof_needed = TRUE;
11112 if (ssh->version == 1) {
11113 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
11114 } else if (ssh->mainchan) {
11115 sshfwd_write_eof(ssh->mainchan);
11116 ssh->send_ok = 0; /* now stop trying to read from stdin */
11118 logevent("Sent EOF message");
11119 } else if (code == TS_PING || code == TS_NOP) {
11120 if (ssh->state == SSH_STATE_CLOSED
11121 || ssh->state == SSH_STATE_PREPACKET) return;
11122 if (ssh->version == 1) {
11123 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11124 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
11126 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
11127 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
11128 ssh2_pkt_addstring_start(pktout);
11129 ssh2_pkt_send_noqueue(ssh, pktout);
11132 } else if (code == TS_REKEY) {
11133 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11134 ssh->version == 2) {
11135 do_ssh2_transport(ssh, "at user request", -1, NULL);
11137 } else if (code == TS_BRK) {
11138 if (ssh->state == SSH_STATE_CLOSED
11139 || ssh->state == SSH_STATE_PREPACKET) return;
11140 if (ssh->version == 1) {
11141 logevent("Unable to send BREAK signal in SSH-1");
11142 } else if (ssh->mainchan) {
11143 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
11144 ssh2_pkt_adduint32(pktout, 0); /* default break length */
11145 ssh2_pkt_send(ssh, pktout);
11148 /* Is is a POSIX signal? */
11149 char *signame = NULL;
11150 if (code == TS_SIGABRT) signame = "ABRT";
11151 if (code == TS_SIGALRM) signame = "ALRM";
11152 if (code == TS_SIGFPE) signame = "FPE";
11153 if (code == TS_SIGHUP) signame = "HUP";
11154 if (code == TS_SIGILL) signame = "ILL";
11155 if (code == TS_SIGINT) signame = "INT";
11156 if (code == TS_SIGKILL) signame = "KILL";
11157 if (code == TS_SIGPIPE) signame = "PIPE";
11158 if (code == TS_SIGQUIT) signame = "QUIT";
11159 if (code == TS_SIGSEGV) signame = "SEGV";
11160 if (code == TS_SIGTERM) signame = "TERM";
11161 if (code == TS_SIGUSR1) signame = "USR1";
11162 if (code == TS_SIGUSR2) signame = "USR2";
11163 /* The SSH-2 protocol does in principle support arbitrary named
11164 * signals, including signame@domain, but we don't support those. */
11166 /* It's a signal. */
11167 if (ssh->version == 2 && ssh->mainchan) {
11168 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
11169 ssh2_pkt_addstring(pktout, signame);
11170 ssh2_pkt_send(ssh, pktout);
11171 logeventf(ssh, "Sent signal SIG%s", signame);
11174 /* Never heard of it. Do nothing */
11179 void *new_sock_channel(void *handle, struct PortForwarding *pf)
11181 Ssh ssh = (Ssh) handle;
11182 struct ssh_channel *c;
11183 c = snew(struct ssh_channel);
11186 ssh2_channel_init(c);
11187 c->halfopen = TRUE;
11188 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
11190 add234(ssh->channels, c);
11194 unsigned ssh_alloc_sharing_channel(Ssh ssh, void *sharing_ctx)
11196 struct ssh_channel *c;
11197 c = snew(struct ssh_channel);
11200 ssh2_channel_init(c);
11201 c->type = CHAN_SHARING;
11202 c->u.sharing.ctx = sharing_ctx;
11203 add234(ssh->channels, c);
11207 void ssh_delete_sharing_channel(Ssh ssh, unsigned localid)
11209 struct ssh_channel *c;
11211 c = find234(ssh->channels, &localid, ssh_channelfind);
11213 ssh_channel_destroy(c);
11216 void ssh_send_packet_from_downstream(Ssh ssh, unsigned id, int type,
11217 const void *data, int datalen,
11218 const char *additional_log_text)
11220 struct Packet *pkt;
11222 pkt = ssh2_pkt_init(type);
11223 pkt->downstream_id = id;
11224 pkt->additional_log_text = additional_log_text;
11225 ssh2_pkt_adddata(pkt, data, datalen);
11226 ssh2_pkt_send(ssh, pkt);
11230 * This is called when stdout/stderr (the entity to which
11231 * from_backend sends data) manages to clear some backlog.
11233 static void ssh_unthrottle(void *handle, int bufsize)
11235 Ssh ssh = (Ssh) handle;
11238 if (ssh->version == 1) {
11239 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
11240 ssh->v1_stdout_throttling = 0;
11241 ssh_throttle_conn(ssh, -1);
11244 if (ssh->mainchan) {
11245 ssh2_set_window(ssh->mainchan,
11246 bufsize < ssh->mainchan->v.v2.locmaxwin ?
11247 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
11248 if (ssh_is_simple(ssh))
11251 buflimit = ssh->mainchan->v.v2.locmaxwin;
11252 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
11253 ssh->mainchan->throttling_conn = 0;
11254 ssh_throttle_conn(ssh, -1);
11260 * Now process any SSH connection data that was stashed in our
11261 * queue while we were frozen.
11263 ssh_process_queued_incoming_data(ssh);
11266 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
11268 struct ssh_channel *c = (struct ssh_channel *)channel;
11270 struct Packet *pktout;
11272 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
11274 if (ssh->version == 1) {
11275 send_packet(ssh, SSH1_MSG_PORT_OPEN,
11276 PKT_INT, c->localid,
11279 /* PKT_STR, <org:orgport>, */
11282 pktout = ssh2_chanopen_init(c, "direct-tcpip");
11284 char *trimmed_host = host_strduptrim(hostname);
11285 ssh2_pkt_addstring(pktout, trimmed_host);
11286 sfree(trimmed_host);
11288 ssh2_pkt_adduint32(pktout, port);
11290 * We make up values for the originator data; partly it's
11291 * too much hassle to keep track, and partly I'm not
11292 * convinced the server should be told details like that
11293 * about my local network configuration.
11294 * The "originator IP address" is syntactically a numeric
11295 * IP address, and some servers (e.g., Tectia) get upset
11296 * if it doesn't match this syntax.
11298 ssh2_pkt_addstring(pktout, "0.0.0.0");
11299 ssh2_pkt_adduint32(pktout, 0);
11300 ssh2_pkt_send(ssh, pktout);
11304 static int ssh_connected(void *handle)
11306 Ssh ssh = (Ssh) handle;
11307 return ssh->s != NULL;
11310 static int ssh_sendok(void *handle)
11312 Ssh ssh = (Ssh) handle;
11313 return ssh->send_ok;
11316 static int ssh_ldisc(void *handle, int option)
11318 Ssh ssh = (Ssh) handle;
11319 if (option == LD_ECHO)
11320 return ssh->echoing;
11321 if (option == LD_EDIT)
11322 return ssh->editing;
11326 static void ssh_provide_ldisc(void *handle, void *ldisc)
11328 Ssh ssh = (Ssh) handle;
11329 ssh->ldisc = ldisc;
11332 static void ssh_provide_logctx(void *handle, void *logctx)
11334 Ssh ssh = (Ssh) handle;
11335 ssh->logctx = logctx;
11338 static int ssh_return_exitcode(void *handle)
11340 Ssh ssh = (Ssh) handle;
11341 if (ssh->s != NULL)
11344 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
11348 * cfg_info for SSH is the protocol running in this session.
11349 * (1 or 2 for the full SSH-1 or SSH-2 protocol; -1 for the bare
11350 * SSH-2 connection protocol, i.e. a downstream; 0 for not-decided-yet.)
11352 static int ssh_cfg_info(void *handle)
11354 Ssh ssh = (Ssh) handle;
11355 if (ssh->version == 0)
11356 return 0; /* don't know yet */
11357 else if (ssh->bare_connection)
11360 return ssh->version;
11364 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
11365 * that fails. This variable is the means by which scp.c can reach
11366 * into the SSH code and find out which one it got.
11368 extern int ssh_fallback_cmd(void *handle)
11370 Ssh ssh = (Ssh) handle;
11371 return ssh->fallback_cmd;
11374 Backend ssh_backend = {
11384 ssh_return_exitcode,
11388 ssh_provide_logctx,