28 * Packet type contexts, so that ssh2_pkt_type can correctly decode
29 * the ambiguous type numbers back into the correct type strings.
40 SSH2_PKTCTX_PUBLICKEY,
46 static const char *const ssh2_disconnect_reasons[] = {
48 "host not allowed to connect",
50 "key exchange failed",
51 "host authentication failed",
54 "service not available",
55 "protocol version not supported",
56 "host key not verifiable",
59 "too many connections",
60 "auth cancelled by user",
61 "no more auth methods available",
66 * Various remote-bug flags.
68 #define BUG_CHOKES_ON_SSH1_IGNORE 1
69 #define BUG_SSH2_HMAC 2
70 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
71 #define BUG_CHOKES_ON_RSA 8
72 #define BUG_SSH2_RSA_PADDING 16
73 #define BUG_SSH2_DERIVEKEY 32
74 #define BUG_SSH2_REKEY 64
75 #define BUG_SSH2_PK_SESSIONID 128
76 #define BUG_SSH2_MAXPKT 256
77 #define BUG_CHOKES_ON_SSH2_IGNORE 512
78 #define BUG_CHOKES_ON_WINADJ 1024
79 #define BUG_SENDS_LATE_REQUEST_REPLY 2048
82 * Codes for terminal modes.
83 * Most of these are the same in SSH-1 and SSH-2.
84 * This list is derived from RFC 4254 and
88 const char* const mode;
90 enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
92 /* "V" prefix discarded for special characters relative to SSH specs */
93 { "INTR", 1, TTY_OP_CHAR },
94 { "QUIT", 2, TTY_OP_CHAR },
95 { "ERASE", 3, TTY_OP_CHAR },
96 { "KILL", 4, TTY_OP_CHAR },
97 { "EOF", 5, TTY_OP_CHAR },
98 { "EOL", 6, TTY_OP_CHAR },
99 { "EOL2", 7, TTY_OP_CHAR },
100 { "START", 8, TTY_OP_CHAR },
101 { "STOP", 9, TTY_OP_CHAR },
102 { "SUSP", 10, TTY_OP_CHAR },
103 { "DSUSP", 11, TTY_OP_CHAR },
104 { "REPRINT", 12, TTY_OP_CHAR },
105 { "WERASE", 13, TTY_OP_CHAR },
106 { "LNEXT", 14, TTY_OP_CHAR },
107 { "FLUSH", 15, TTY_OP_CHAR },
108 { "SWTCH", 16, TTY_OP_CHAR },
109 { "STATUS", 17, TTY_OP_CHAR },
110 { "DISCARD", 18, TTY_OP_CHAR },
111 { "IGNPAR", 30, TTY_OP_BOOL },
112 { "PARMRK", 31, TTY_OP_BOOL },
113 { "INPCK", 32, TTY_OP_BOOL },
114 { "ISTRIP", 33, TTY_OP_BOOL },
115 { "INLCR", 34, TTY_OP_BOOL },
116 { "IGNCR", 35, TTY_OP_BOOL },
117 { "ICRNL", 36, TTY_OP_BOOL },
118 { "IUCLC", 37, TTY_OP_BOOL },
119 { "IXON", 38, TTY_OP_BOOL },
120 { "IXANY", 39, TTY_OP_BOOL },
121 { "IXOFF", 40, TTY_OP_BOOL },
122 { "IMAXBEL", 41, TTY_OP_BOOL },
123 { "ISIG", 50, TTY_OP_BOOL },
124 { "ICANON", 51, TTY_OP_BOOL },
125 { "XCASE", 52, TTY_OP_BOOL },
126 { "ECHO", 53, TTY_OP_BOOL },
127 { "ECHOE", 54, TTY_OP_BOOL },
128 { "ECHOK", 55, TTY_OP_BOOL },
129 { "ECHONL", 56, TTY_OP_BOOL },
130 { "NOFLSH", 57, TTY_OP_BOOL },
131 { "TOSTOP", 58, TTY_OP_BOOL },
132 { "IEXTEN", 59, TTY_OP_BOOL },
133 { "ECHOCTL", 60, TTY_OP_BOOL },
134 { "ECHOKE", 61, TTY_OP_BOOL },
135 { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */
136 { "OPOST", 70, TTY_OP_BOOL },
137 { "OLCUC", 71, TTY_OP_BOOL },
138 { "ONLCR", 72, TTY_OP_BOOL },
139 { "OCRNL", 73, TTY_OP_BOOL },
140 { "ONOCR", 74, TTY_OP_BOOL },
141 { "ONLRET", 75, TTY_OP_BOOL },
142 { "CS7", 90, TTY_OP_BOOL },
143 { "CS8", 91, TTY_OP_BOOL },
144 { "PARENB", 92, TTY_OP_BOOL },
145 { "PARODD", 93, TTY_OP_BOOL }
148 /* Miscellaneous other tty-related constants. */
149 #define SSH_TTY_OP_END 0
150 /* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */
151 #define SSH1_TTY_OP_ISPEED 192
152 #define SSH1_TTY_OP_OSPEED 193
153 #define SSH2_TTY_OP_ISPEED 128
154 #define SSH2_TTY_OP_OSPEED 129
156 /* Helper functions for parsing tty-related config. */
157 static unsigned int ssh_tty_parse_specchar(char *s)
162 ret = ctrlparse(s, &next);
163 if (!next) ret = s[0];
165 ret = 255; /* special value meaning "don't set" */
169 static unsigned int ssh_tty_parse_boolean(char *s)
171 if (stricmp(s, "yes") == 0 ||
172 stricmp(s, "on") == 0 ||
173 stricmp(s, "true") == 0 ||
174 stricmp(s, "+") == 0)
176 else if (stricmp(s, "no") == 0 ||
177 stricmp(s, "off") == 0 ||
178 stricmp(s, "false") == 0 ||
179 stricmp(s, "-") == 0)
180 return 0; /* false */
182 return (atoi(s) != 0);
185 #define translate(x) if (type == x) return #x
186 #define translatek(x,ctx) if (type == x && (pkt_kctx == ctx)) return #x
187 #define translatea(x,ctx) if (type == x && (pkt_actx == ctx)) return #x
188 static char *ssh1_pkt_type(int type)
190 translate(SSH1_MSG_DISCONNECT);
191 translate(SSH1_SMSG_PUBLIC_KEY);
192 translate(SSH1_CMSG_SESSION_KEY);
193 translate(SSH1_CMSG_USER);
194 translate(SSH1_CMSG_AUTH_RSA);
195 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
196 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
197 translate(SSH1_CMSG_AUTH_PASSWORD);
198 translate(SSH1_CMSG_REQUEST_PTY);
199 translate(SSH1_CMSG_WINDOW_SIZE);
200 translate(SSH1_CMSG_EXEC_SHELL);
201 translate(SSH1_CMSG_EXEC_CMD);
202 translate(SSH1_SMSG_SUCCESS);
203 translate(SSH1_SMSG_FAILURE);
204 translate(SSH1_CMSG_STDIN_DATA);
205 translate(SSH1_SMSG_STDOUT_DATA);
206 translate(SSH1_SMSG_STDERR_DATA);
207 translate(SSH1_CMSG_EOF);
208 translate(SSH1_SMSG_EXIT_STATUS);
209 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
210 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
211 translate(SSH1_MSG_CHANNEL_DATA);
212 translate(SSH1_MSG_CHANNEL_CLOSE);
213 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
214 translate(SSH1_SMSG_X11_OPEN);
215 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
216 translate(SSH1_MSG_PORT_OPEN);
217 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
218 translate(SSH1_SMSG_AGENT_OPEN);
219 translate(SSH1_MSG_IGNORE);
220 translate(SSH1_CMSG_EXIT_CONFIRMATION);
221 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
222 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
223 translate(SSH1_MSG_DEBUG);
224 translate(SSH1_CMSG_REQUEST_COMPRESSION);
225 translate(SSH1_CMSG_AUTH_TIS);
226 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
227 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
228 translate(SSH1_CMSG_AUTH_CCARD);
229 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
230 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
233 static char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx, int type)
235 translatea(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,SSH2_PKTCTX_GSSAPI);
236 translatea(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,SSH2_PKTCTX_GSSAPI);
237 translatea(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,SSH2_PKTCTX_GSSAPI);
238 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERROR,SSH2_PKTCTX_GSSAPI);
239 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK,SSH2_PKTCTX_GSSAPI);
240 translatea(SSH2_MSG_USERAUTH_GSSAPI_MIC, SSH2_PKTCTX_GSSAPI);
241 translate(SSH2_MSG_DISCONNECT);
242 translate(SSH2_MSG_IGNORE);
243 translate(SSH2_MSG_UNIMPLEMENTED);
244 translate(SSH2_MSG_DEBUG);
245 translate(SSH2_MSG_SERVICE_REQUEST);
246 translate(SSH2_MSG_SERVICE_ACCEPT);
247 translate(SSH2_MSG_KEXINIT);
248 translate(SSH2_MSG_NEWKEYS);
249 translatek(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
250 translatek(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
251 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
252 translatek(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
253 translatek(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
254 translatek(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
255 translatek(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX);
256 translatek(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX);
257 translatek(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX);
258 translatek(SSH2_MSG_KEX_ECDH_INIT, SSH2_PKTCTX_ECDHKEX);
259 translatek(SSH2_MSG_KEX_ECDH_REPLY, SSH2_PKTCTX_ECDHKEX);
260 translate(SSH2_MSG_USERAUTH_REQUEST);
261 translate(SSH2_MSG_USERAUTH_FAILURE);
262 translate(SSH2_MSG_USERAUTH_SUCCESS);
263 translate(SSH2_MSG_USERAUTH_BANNER);
264 translatea(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
265 translatea(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
266 translatea(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
267 translatea(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
268 translate(SSH2_MSG_GLOBAL_REQUEST);
269 translate(SSH2_MSG_REQUEST_SUCCESS);
270 translate(SSH2_MSG_REQUEST_FAILURE);
271 translate(SSH2_MSG_CHANNEL_OPEN);
272 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
273 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
274 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
275 translate(SSH2_MSG_CHANNEL_DATA);
276 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
277 translate(SSH2_MSG_CHANNEL_EOF);
278 translate(SSH2_MSG_CHANNEL_CLOSE);
279 translate(SSH2_MSG_CHANNEL_REQUEST);
280 translate(SSH2_MSG_CHANNEL_SUCCESS);
281 translate(SSH2_MSG_CHANNEL_FAILURE);
287 /* Enumeration values for fields in SSH-1 packets */
289 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
293 * Coroutine mechanics for the sillier bits of the code. If these
294 * macros look impenetrable to you, you might find it helpful to
297 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
299 * which explains the theory behind these macros.
301 * In particular, if you are getting `case expression not constant'
302 * errors when building with MS Visual Studio, this is because MS's
303 * Edit and Continue debugging feature causes their compiler to
304 * violate ANSI C. To disable Edit and Continue debugging:
306 * - right-click ssh.c in the FileView
308 * - select the C/C++ tab and the General category
309 * - under `Debug info:', select anything _other_ than `Program
310 * Database for Edit and Continue'.
312 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
313 #define crBeginState crBegin(s->crLine)
314 #define crStateP(t, v) \
316 if (!(v)) { s = (v) = snew(struct t); s->crLine = 0; } \
318 #define crState(t) crStateP(t, ssh->t)
319 #define crFinish(z) } *crLine = 0; return (z); }
320 #define crFinishV } *crLine = 0; return; }
321 #define crFinishFree(z) } sfree(s); return (z); }
322 #define crFinishFreeV } sfree(s); return; }
323 #define crReturn(z) \
325 *crLine =__LINE__; return (z); case __LINE__:;\
329 *crLine=__LINE__; return; case __LINE__:;\
331 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
332 #define crStopV do{ *crLine = 0; return; }while(0)
333 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
334 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
338 static struct Packet *ssh1_pkt_init(int pkt_type);
339 static struct Packet *ssh2_pkt_init(int pkt_type);
340 static void ssh_pkt_ensure(struct Packet *, int length);
341 static void ssh_pkt_adddata(struct Packet *, const void *data, int len);
342 static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
343 static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
344 static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
345 static void ssh_pkt_addstring_start(struct Packet *);
346 static void ssh_pkt_addstring_str(struct Packet *, const char *data);
347 static void ssh_pkt_addstring_data(struct Packet *, const char *data, int len);
348 static void ssh_pkt_addstring(struct Packet *, const char *data);
349 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
350 static void ssh1_pkt_addmp(struct Packet *, Bignum b);
351 static void ssh2_pkt_addmp(struct Packet *, Bignum b);
352 static int ssh2_pkt_construct(Ssh, struct Packet *);
353 static void ssh2_pkt_send(Ssh, struct Packet *);
354 static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
355 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
356 struct Packet *pktin);
357 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
358 struct Packet *pktin);
359 static void ssh2_channel_check_close(struct ssh_channel *c);
360 static void ssh_channel_destroy(struct ssh_channel *c);
363 * Buffer management constants. There are several of these for
364 * various different purposes:
366 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
367 * on a local data stream before we throttle the whole SSH
368 * connection (in SSH-1 only). Throttling the whole connection is
369 * pretty drastic so we set this high in the hope it won't
372 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
373 * on the SSH connection itself before we defensively throttle
374 * _all_ local data streams. This is pretty drastic too (though
375 * thankfully unlikely in SSH-2 since the window mechanism should
376 * ensure that the server never has any need to throttle its end
377 * of the connection), so we set this high as well.
379 * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
382 * - OUR_V2_BIGWIN is the window size we advertise for the only
383 * channel in a simple connection. It must be <= INT_MAX.
385 * - OUR_V2_MAXPKT is the official "maximum packet size" we send
386 * to the remote side. This actually has nothing to do with the
387 * size of the _packet_, but is instead a limit on the amount
388 * of data we're willing to receive in a single SSH2 channel
391 * - OUR_V2_PACKETLIMIT is actually the maximum size of SSH
392 * _packet_ we're prepared to cope with. It must be a multiple
393 * of the cipher block size, and must be at least 35000.
396 #define SSH1_BUFFER_LIMIT 32768
397 #define SSH_MAX_BACKLOG 32768
398 #define OUR_V2_WINSIZE 16384
399 #define OUR_V2_BIGWIN 0x7fffffff
400 #define OUR_V2_MAXPKT 0x4000UL
401 #define OUR_V2_PACKETLIMIT 0x9000UL
403 const static struct ssh_signkey *hostkey_algs[] = {
404 &ssh_ecdsa_nistp256, &ssh_ecdsa_nistp384, &ssh_ecdsa_nistp521,
408 const static struct ssh_mac *macs[] = {
409 &ssh_hmac_sha256, &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
411 const static struct ssh_mac *buggymacs[] = {
412 &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
415 static void *ssh_comp_none_init(void)
419 static void ssh_comp_none_cleanup(void *handle)
422 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
423 unsigned char **outblock, int *outlen)
427 static int ssh_comp_none_disable(void *handle)
431 const static struct ssh_compress ssh_comp_none = {
433 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
434 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
435 ssh_comp_none_disable, NULL
437 extern const struct ssh_compress ssh_zlib;
438 const static struct ssh_compress *compressions[] = {
439 &ssh_zlib, &ssh_comp_none
442 enum { /* channel types */
447 CHAN_SOCKDATA_DORMANT, /* one the remote hasn't confirmed */
449 * CHAN_SHARING indicates a channel which is tracked here on
450 * behalf of a connection-sharing downstream. We do almost nothing
451 * with these channels ourselves: all messages relating to them
452 * get thrown straight to sshshare.c and passed on almost
453 * unmodified to downstream.
457 * CHAN_ZOMBIE is used to indicate a channel for which we've
458 * already destroyed the local data source: for instance, if a
459 * forwarded port experiences a socket error on the local side, we
460 * immediately destroy its local socket and turn the SSH channel
466 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
467 typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
468 typedef void (*cchandler_fn_t)(struct ssh_channel *, struct Packet *, void *);
471 * Each channel has a queue of outstanding CHANNEL_REQUESTS and their
474 struct outstanding_channel_request {
475 cchandler_fn_t handler;
477 struct outstanding_channel_request *next;
481 * 2-3-4 tree storing channels.
484 Ssh ssh; /* pointer back to main context */
485 unsigned remoteid, localid;
487 /* True if we opened this channel but server hasn't confirmed. */
490 * In SSH-1, this value contains four bits:
492 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
493 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
494 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
495 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
497 * A channel is completely finished with when all four bits are set.
499 * In SSH-2, the four bits mean:
501 * 1 We have sent SSH2_MSG_CHANNEL_EOF.
502 * 2 We have sent SSH2_MSG_CHANNEL_CLOSE.
503 * 4 We have received SSH2_MSG_CHANNEL_EOF.
504 * 8 We have received SSH2_MSG_CHANNEL_CLOSE.
506 * A channel is completely finished with when we have both sent
507 * and received CLOSE.
509 * The symbolic constants below use the SSH-2 terminology, which
510 * is a bit confusing in SSH-1, but we have to use _something_.
512 #define CLOSES_SENT_EOF 1
513 #define CLOSES_SENT_CLOSE 2
514 #define CLOSES_RCVD_EOF 4
515 #define CLOSES_RCVD_CLOSE 8
519 * This flag indicates that an EOF is pending on the outgoing side
520 * of the channel: that is, wherever we're getting the data for
521 * this channel has sent us some data followed by EOF. We can't
522 * actually send the EOF until we've finished sending the data, so
523 * we set this flag instead to remind us to do so once our buffer
529 * True if this channel is causing the underlying connection to be
534 struct ssh2_data_channel {
536 unsigned remwindow, remmaxpkt;
537 /* locwindow is signed so we can cope with excess data. */
538 int locwindow, locmaxwin;
540 * remlocwin is the amount of local window that we think
541 * the remote end had available to it after it sent the
542 * last data packet or window adjust ack.
546 * These store the list of channel requests that haven't
549 struct outstanding_channel_request *chanreq_head, *chanreq_tail;
550 enum { THROTTLED, UNTHROTTLING, UNTHROTTLED } throttle_state;
554 struct ssh_agent_channel {
555 unsigned char *message;
556 unsigned char msglen[4];
557 unsigned lensofar, totallen;
558 int outstanding_requests;
560 struct ssh_x11_channel {
561 struct X11Connection *xconn;
564 struct ssh_pfd_channel {
565 struct PortForwarding *pf;
567 struct ssh_sharing_channel {
574 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
575 * use this structure in different ways, reflecting SSH-2's
576 * altogether saner approach to port forwarding.
578 * In SSH-1, you arrange a remote forwarding by sending the server
579 * the remote port number, and the local destination host:port.
580 * When a connection comes in, the server sends you back that
581 * host:port pair, and you connect to it. This is a ready-made
582 * security hole if you're not on the ball: a malicious server
583 * could send you back _any_ host:port pair, so if you trustingly
584 * connect to the address it gives you then you've just opened the
585 * entire inside of your corporate network just by connecting
586 * through it to a dodgy SSH server. Hence, we must store a list of
587 * host:port pairs we _are_ trying to forward to, and reject a
588 * connection request from the server if it's not in the list.
590 * In SSH-2, each side of the connection minds its own business and
591 * doesn't send unnecessary information to the other. You arrange a
592 * remote forwarding by sending the server just the remote port
593 * number. When a connection comes in, the server tells you which
594 * of its ports was connected to; and _you_ have to remember what
595 * local host:port pair went with that port number.
597 * Hence, in SSH-1 this structure is indexed by destination
598 * host:port pair, whereas in SSH-2 it is indexed by source port.
600 struct ssh_portfwd; /* forward declaration */
602 struct ssh_rportfwd {
603 unsigned sport, dport;
607 struct ssh_portfwd *pfrec;
610 static void free_rportfwd(struct ssh_rportfwd *pf)
613 sfree(pf->sportdesc);
621 * Separately to the rportfwd tree (which is for looking up port
622 * open requests from the server), a tree of _these_ structures is
623 * used to keep track of all the currently open port forwardings,
624 * so that we can reconfigure in mid-session if the user requests
628 enum { DESTROY, KEEP, CREATE } status;
630 unsigned sport, dport;
633 struct ssh_rportfwd *remote;
635 struct PortListener *local;
637 #define free_portfwd(pf) ( \
638 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
639 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
642 long length; /* length of packet: see below */
643 long forcepad; /* SSH-2: force padding to at least this length */
644 int type; /* only used for incoming packets */
645 unsigned long sequence; /* SSH-2 incoming sequence number */
646 unsigned char *data; /* allocated storage */
647 unsigned char *body; /* offset of payload within `data' */
648 long savedpos; /* dual-purpose saved packet position: see below */
649 long maxlen; /* amount of storage allocated for `data' */
650 long encrypted_len; /* for SSH-2 total-size counting */
653 * A note on the 'length' and 'savedpos' fields above.
655 * Incoming packets are set up so that pkt->length is measured
656 * relative to pkt->body, which itself points to a few bytes after
657 * pkt->data (skipping some uninteresting header fields including
658 * the packet type code). The ssh_pkt_get* functions all expect
659 * this setup, and they also use pkt->savedpos to indicate how far
660 * through the packet being decoded they've got - and that, too,
661 * is an offset from pkt->body rather than pkt->data.
663 * During construction of an outgoing packet, however, pkt->length
664 * is measured relative to the base pointer pkt->data, and
665 * pkt->body is not really used for anything until the packet is
666 * ready for sending. In this mode, pkt->savedpos is reused as a
667 * temporary variable by the addstring functions, which write out
668 * a string length field and then keep going back and updating it
669 * as more data is appended to the subsequent string data field;
670 * pkt->savedpos stores the offset (again relative to pkt->data)
671 * of the start of the string data field.
674 /* Extra metadata used in SSH packet logging mode, allowing us to
675 * log in the packet header line that the packet came from a
676 * connection-sharing downstream and what if anything unusual was
677 * done to it. The additional_log_text field is expected to be a
678 * static string - it will not be freed. */
679 unsigned downstream_id;
680 const char *additional_log_text;
683 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
684 struct Packet *pktin);
685 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
686 struct Packet *pktin);
687 static void ssh2_bare_connection_protocol(Ssh ssh, void *vin, int inlen,
688 struct Packet *pktin);
689 static void ssh1_protocol_setup(Ssh ssh);
690 static void ssh2_protocol_setup(Ssh ssh);
691 static void ssh2_bare_connection_protocol_setup(Ssh ssh);
692 static void ssh_size(void *handle, int width, int height);
693 static void ssh_special(void *handle, Telnet_Special);
694 static int ssh2_try_send(struct ssh_channel *c);
695 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
696 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
697 static void ssh2_set_window(struct ssh_channel *c, int newwin);
698 static int ssh_sendbuffer(void *handle);
699 static int ssh_do_close(Ssh ssh, int notify_exit);
700 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
701 static int ssh2_pkt_getbool(struct Packet *pkt);
702 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
703 static void ssh2_timer(void *ctx, unsigned long now);
704 static void do_ssh2_transport(Ssh ssh, void *vin, int inlen,
705 struct Packet *pktin);
706 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin);
708 struct rdpkt1_state_tag {
709 long len, pad, biglen, to_read;
710 unsigned long realcrc, gotcrc;
714 struct Packet *pktin;
717 struct rdpkt2_state_tag {
718 long len, pad, payload, packetlen, maclen;
721 unsigned long incoming_sequence;
722 struct Packet *pktin;
725 struct rdpkt2_bare_state_tag {
729 unsigned long incoming_sequence;
730 struct Packet *pktin;
733 struct queued_handler;
734 struct queued_handler {
736 chandler_fn_t handler;
738 struct queued_handler *next;
742 const struct plug_function_table *fn;
743 /* the above field _must_ be first in the structure */
753 unsigned char session_key[32];
755 int v1_remote_protoflags;
756 int v1_local_protoflags;
757 int agentfwd_enabled;
760 const struct ssh_cipher *cipher;
763 const struct ssh2_cipher *cscipher, *sccipher;
764 void *cs_cipher_ctx, *sc_cipher_ctx;
765 const struct ssh_mac *csmac, *scmac;
766 void *cs_mac_ctx, *sc_mac_ctx;
767 const struct ssh_compress *cscomp, *sccomp;
768 void *cs_comp_ctx, *sc_comp_ctx;
769 const struct ssh_kex *kex;
770 const struct ssh_signkey *hostkey;
771 char *hostkey_str; /* string representation, for easy checking in rekeys */
772 unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN];
773 int v2_session_id_len;
777 int attempting_connshare;
783 int echoing, editing;
787 int ospeed, ispeed; /* temporaries */
788 int term_width, term_height;
790 tree234 *channels; /* indexed by local id */
791 struct ssh_channel *mainchan; /* primary session channel */
792 int ncmode; /* is primary channel direct-tcpip? */
797 tree234 *rportfwds, *portfwds;
801 SSH_STATE_BEFORE_SIZE,
807 int size_needed, eof_needed;
808 int sent_console_eof;
809 int got_pty; /* affects EOF behaviour on main channel */
811 struct Packet **queue;
812 int queuelen, queuesize;
814 unsigned char *deferred_send_data;
815 int deferred_len, deferred_size;
818 * Gross hack: pscp will try to start SFTP but fall back to
819 * scp1 if that fails. This variable is the means by which
820 * scp.c can reach into the SSH code and find out which one it
825 bufchain banner; /* accumulates banners during do_ssh2_authconn */
830 struct X11Display *x11disp;
831 struct X11FakeAuth *x11auth;
832 tree234 *x11authtree;
835 int conn_throttle_count;
838 int v1_stdout_throttling;
839 unsigned long v2_outgoing_sequence;
841 int ssh1_rdpkt_crstate;
842 int ssh2_rdpkt_crstate;
843 int ssh2_bare_rdpkt_crstate;
844 int ssh_gotdata_crstate;
845 int do_ssh1_connection_crstate;
847 void *do_ssh_init_state;
848 void *do_ssh1_login_state;
849 void *do_ssh2_transport_state;
850 void *do_ssh2_authconn_state;
851 void *do_ssh_connection_init_state;
853 struct rdpkt1_state_tag rdpkt1_state;
854 struct rdpkt2_state_tag rdpkt2_state;
855 struct rdpkt2_bare_state_tag rdpkt2_bare_state;
857 /* SSH-1 and SSH-2 use this for different things, but both use it */
858 int protocol_initial_phase_done;
860 void (*protocol) (Ssh ssh, void *vin, int inlen,
862 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
863 int (*do_ssh_init)(Ssh ssh, unsigned char c);
866 * We maintain our own copy of a Conf structure here. That way,
867 * when we're passed a new one for reconfiguration, we can check
868 * the differences and potentially reconfigure port forwardings
869 * etc in mid-session.
874 * Values cached out of conf so as to avoid the tree234 lookup
875 * cost every time they're used.
880 * Dynamically allocated username string created during SSH
881 * login. Stored in here rather than in the coroutine state so
882 * that it'll be reliably freed if we shut down the SSH session
883 * at some unexpected moment.
888 * Used to transfer data back from async callbacks.
890 void *agent_response;
891 int agent_response_len;
895 * The SSH connection can be set as `frozen', meaning we are
896 * not currently accepting incoming data from the network. This
897 * is slightly more serious than setting the _socket_ as
898 * frozen, because we may already have had data passed to us
899 * from the network which we need to delay processing until
900 * after the freeze is lifted, so we also need a bufchain to
904 bufchain queued_incoming_data;
907 * Dispatch table for packet types that we may have to deal
910 handler_fn_t packet_dispatch[256];
913 * Queues of one-off handler functions for success/failure
914 * indications from a request.
916 struct queued_handler *qhead, *qtail;
917 handler_fn_t q_saved_handler1, q_saved_handler2;
920 * This module deals with sending keepalives.
925 * Track incoming and outgoing data sizes and time, for
928 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
929 unsigned long max_data_size;
931 unsigned long next_rekey, last_rekey;
932 char *deferred_rekey_reason; /* points to STATIC string; don't free */
935 * Fully qualified host name, which we need if doing GSSAPI.
941 * GSSAPI libraries for this session.
943 struct ssh_gss_liblist *gsslibs;
947 #define logevent(s) logevent(ssh->frontend, s)
949 /* logevent, only printf-formatted. */
950 static void logeventf(Ssh ssh, const char *fmt, ...)
956 buf = dupvprintf(fmt, ap);
962 static void bomb_out(Ssh ssh, char *text)
964 ssh_do_close(ssh, FALSE);
966 connection_fatal(ssh->frontend, "%s", text);
970 #define bombout(msg) bomb_out(ssh, dupprintf msg)
972 /* Helper function for common bits of parsing ttymodes. */
973 static void parse_ttymodes(Ssh ssh,
974 void (*do_mode)(void *data, char *mode, char *val),
979 for (val = conf_get_str_strs(ssh->conf, CONF_ttymodes, NULL, &key);
981 val = conf_get_str_strs(ssh->conf, CONF_ttymodes, key, &key)) {
983 * val[0] is either 'V', indicating that an explicit value
984 * follows it, or 'A' indicating that we should pass the
985 * value through from the local environment via get_ttymode.
988 val = get_ttymode(ssh->frontend, key);
990 do_mode(data, key, val);
994 do_mode(data, key, val + 1); /* skip the 'V' */
998 static int ssh_channelcmp(void *av, void *bv)
1000 struct ssh_channel *a = (struct ssh_channel *) av;
1001 struct ssh_channel *b = (struct ssh_channel *) bv;
1002 if (a->localid < b->localid)
1004 if (a->localid > b->localid)
1008 static int ssh_channelfind(void *av, void *bv)
1010 unsigned *a = (unsigned *) av;
1011 struct ssh_channel *b = (struct ssh_channel *) bv;
1012 if (*a < b->localid)
1014 if (*a > b->localid)
1019 static int ssh_rportcmp_ssh1(void *av, void *bv)
1021 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1022 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1024 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
1025 return i < 0 ? -1 : +1;
1026 if (a->dport > b->dport)
1028 if (a->dport < b->dport)
1033 static int ssh_rportcmp_ssh2(void *av, void *bv)
1035 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1036 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1038 if ( (i = strcmp(a->shost, b->shost)) != 0)
1039 return i < 0 ? -1 : +1;
1040 if (a->sport > b->sport)
1042 if (a->sport < b->sport)
1048 * Special form of strcmp which can cope with NULL inputs. NULL is
1049 * defined to sort before even the empty string.
1051 static int nullstrcmp(const char *a, const char *b)
1053 if (a == NULL && b == NULL)
1059 return strcmp(a, b);
1062 static int ssh_portcmp(void *av, void *bv)
1064 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
1065 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
1067 if (a->type > b->type)
1069 if (a->type < b->type)
1071 if (a->addressfamily > b->addressfamily)
1073 if (a->addressfamily < b->addressfamily)
1075 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
1076 return i < 0 ? -1 : +1;
1077 if (a->sport > b->sport)
1079 if (a->sport < b->sport)
1081 if (a->type != 'D') {
1082 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
1083 return i < 0 ? -1 : +1;
1084 if (a->dport > b->dport)
1086 if (a->dport < b->dport)
1092 static int alloc_channel_id(Ssh ssh)
1094 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1095 unsigned low, high, mid;
1097 struct ssh_channel *c;
1100 * First-fit allocation of channel numbers: always pick the
1101 * lowest unused one. To do this, binary-search using the
1102 * counted B-tree to find the largest channel ID which is in a
1103 * contiguous sequence from the beginning. (Precisely
1104 * everything in that sequence must have ID equal to its tree
1105 * index plus CHANNEL_NUMBER_OFFSET.)
1107 tsize = count234(ssh->channels);
1111 while (high - low > 1) {
1112 mid = (high + low) / 2;
1113 c = index234(ssh->channels, mid);
1114 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1115 low = mid; /* this one is fine */
1117 high = mid; /* this one is past it */
1120 * Now low points to either -1, or the tree index of the
1121 * largest ID in the initial sequence.
1124 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
1125 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
1127 return low + 1 + CHANNEL_NUMBER_OFFSET;
1130 static void c_write_stderr(int trusted, const char *buf, int len)
1133 for (i = 0; i < len; i++)
1134 if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60)))
1135 fputc(buf[i], stderr);
1138 static void c_write(Ssh ssh, const char *buf, int len)
1140 if (flags & FLAG_STDERR)
1141 c_write_stderr(1, buf, len);
1143 from_backend(ssh->frontend, 1, buf, len);
1146 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
1148 if (flags & FLAG_STDERR)
1149 c_write_stderr(0, buf, len);
1151 from_backend_untrusted(ssh->frontend, buf, len);
1154 static void c_write_str(Ssh ssh, const char *buf)
1156 c_write(ssh, buf, strlen(buf));
1159 static void ssh_free_packet(struct Packet *pkt)
1164 static struct Packet *ssh_new_packet(void)
1166 struct Packet *pkt = snew(struct Packet);
1168 pkt->body = pkt->data = NULL;
1174 static void ssh1_log_incoming_packet(Ssh ssh, struct Packet *pkt)
1177 struct logblank_t blanks[4];
1183 if (ssh->logomitdata &&
1184 (pkt->type == SSH1_SMSG_STDOUT_DATA ||
1185 pkt->type == SSH1_SMSG_STDERR_DATA ||
1186 pkt->type == SSH1_MSG_CHANNEL_DATA)) {
1187 /* "Session data" packets - omit the data string. */
1188 if (pkt->type == SSH1_MSG_CHANNEL_DATA)
1189 ssh_pkt_getuint32(pkt); /* skip channel id */
1190 blanks[nblanks].offset = pkt->savedpos + 4;
1191 blanks[nblanks].type = PKTLOG_OMIT;
1192 ssh_pkt_getstring(pkt, &str, &slen);
1194 blanks[nblanks].len = slen;
1198 log_packet(ssh->logctx, PKT_INCOMING, pkt->type,
1199 ssh1_pkt_type(pkt->type),
1200 pkt->body, pkt->length, nblanks, blanks, NULL,
1204 static void ssh1_log_outgoing_packet(Ssh ssh, struct Packet *pkt)
1207 struct logblank_t blanks[4];
1212 * For outgoing packets, pkt->length represents the length of the
1213 * whole packet starting at pkt->data (including some header), and
1214 * pkt->body refers to the point within that where the log-worthy
1215 * payload begins. However, incoming packets expect pkt->length to
1216 * represent only the payload length (that is, it's measured from
1217 * pkt->body not from pkt->data). Temporarily adjust our outgoing
1218 * packet to conform to the incoming-packet semantics, so that we
1219 * can analyse it with the ssh_pkt_get functions.
1221 pkt->length -= (pkt->body - pkt->data);
1224 if (ssh->logomitdata &&
1225 (pkt->type == SSH1_CMSG_STDIN_DATA ||
1226 pkt->type == SSH1_MSG_CHANNEL_DATA)) {
1227 /* "Session data" packets - omit the data string. */
1228 if (pkt->type == SSH1_MSG_CHANNEL_DATA)
1229 ssh_pkt_getuint32(pkt); /* skip channel id */
1230 blanks[nblanks].offset = pkt->savedpos + 4;
1231 blanks[nblanks].type = PKTLOG_OMIT;
1232 ssh_pkt_getstring(pkt, &str, &slen);
1234 blanks[nblanks].len = slen;
1239 if ((pkt->type == SSH1_CMSG_AUTH_PASSWORD ||
1240 pkt->type == SSH1_CMSG_AUTH_TIS_RESPONSE ||
1241 pkt->type == SSH1_CMSG_AUTH_CCARD_RESPONSE) &&
1242 conf_get_int(ssh->conf, CONF_logomitpass)) {
1243 /* If this is a password or similar packet, blank the password(s). */
1244 blanks[nblanks].offset = 0;
1245 blanks[nblanks].len = pkt->length;
1246 blanks[nblanks].type = PKTLOG_BLANK;
1248 } else if (pkt->type == SSH1_CMSG_X11_REQUEST_FORWARDING &&
1249 conf_get_int(ssh->conf, CONF_logomitpass)) {
1251 * If this is an X forwarding request packet, blank the fake
1254 * Note that while we blank the X authentication data here, we
1255 * don't take any special action to blank the start of an X11
1256 * channel, so using MIT-MAGIC-COOKIE-1 and actually opening
1257 * an X connection without having session blanking enabled is
1258 * likely to leak your cookie into the log.
1261 ssh_pkt_getstring(pkt, &str, &slen);
1262 blanks[nblanks].offset = pkt->savedpos;
1263 blanks[nblanks].type = PKTLOG_BLANK;
1264 ssh_pkt_getstring(pkt, &str, &slen);
1266 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1271 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1272 ssh1_pkt_type(pkt->data[12]),
1273 pkt->body, pkt->length,
1274 nblanks, blanks, NULL, 0, NULL);
1277 * Undo the above adjustment of pkt->length, to put the packet
1278 * back in the state we found it.
1280 pkt->length += (pkt->body - pkt->data);
1284 * Collect incoming data in the incoming packet buffer.
1285 * Decipher and verify the packet when it is completely read.
1286 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1287 * Update the *data and *datalen variables.
1288 * Return a Packet structure when a packet is completed.
1290 static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1292 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
1294 crBegin(ssh->ssh1_rdpkt_crstate);
1296 st->pktin = ssh_new_packet();
1298 st->pktin->type = 0;
1299 st->pktin->length = 0;
1301 for (st->i = st->len = 0; st->i < 4; st->i++) {
1302 while ((*datalen) == 0)
1304 st->len = (st->len << 8) + **data;
1305 (*data)++, (*datalen)--;
1308 st->pad = 8 - (st->len % 8);
1309 st->biglen = st->len + st->pad;
1310 st->pktin->length = st->len - 5;
1312 if (st->biglen < 0) {
1313 bombout(("Extremely large packet length from server suggests"
1314 " data stream corruption"));
1315 ssh_free_packet(st->pktin);
1319 st->pktin->maxlen = st->biglen;
1320 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1322 st->to_read = st->biglen;
1323 st->p = st->pktin->data;
1324 while (st->to_read > 0) {
1325 st->chunk = st->to_read;
1326 while ((*datalen) == 0)
1328 if (st->chunk > (*datalen))
1329 st->chunk = (*datalen);
1330 memcpy(st->p, *data, st->chunk);
1332 *datalen -= st->chunk;
1334 st->to_read -= st->chunk;
1337 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1338 st->biglen, NULL)) {
1339 bombout(("Network attack (CRC compensation) detected!"));
1340 ssh_free_packet(st->pktin);
1345 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1347 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1348 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1349 if (st->gotcrc != st->realcrc) {
1350 bombout(("Incorrect CRC received on packet"));
1351 ssh_free_packet(st->pktin);
1355 st->pktin->body = st->pktin->data + st->pad + 1;
1357 if (ssh->v1_compressing) {
1358 unsigned char *decompblk;
1360 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1361 st->pktin->body - 1, st->pktin->length + 1,
1362 &decompblk, &decomplen)) {
1363 bombout(("Zlib decompression encountered invalid data"));
1364 ssh_free_packet(st->pktin);
1368 if (st->pktin->maxlen < st->pad + decomplen) {
1369 st->pktin->maxlen = st->pad + decomplen;
1370 st->pktin->data = sresize(st->pktin->data,
1371 st->pktin->maxlen + APIEXTRA,
1373 st->pktin->body = st->pktin->data + st->pad + 1;
1376 memcpy(st->pktin->body - 1, decompblk, decomplen);
1378 st->pktin->length = decomplen - 1;
1381 st->pktin->type = st->pktin->body[-1];
1384 * Now pktin->body and pktin->length identify the semantic content
1385 * of the packet, excluding the initial type byte.
1389 ssh1_log_incoming_packet(ssh, st->pktin);
1391 st->pktin->savedpos = 0;
1393 crFinish(st->pktin);
1396 static void ssh2_log_incoming_packet(Ssh ssh, struct Packet *pkt)
1399 struct logblank_t blanks[4];
1405 if (ssh->logomitdata &&
1406 (pkt->type == SSH2_MSG_CHANNEL_DATA ||
1407 pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)) {
1408 /* "Session data" packets - omit the data string. */
1409 ssh_pkt_getuint32(pkt); /* skip channel id */
1410 if (pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)
1411 ssh_pkt_getuint32(pkt); /* skip extended data type */
1412 blanks[nblanks].offset = pkt->savedpos + 4;
1413 blanks[nblanks].type = PKTLOG_OMIT;
1414 ssh_pkt_getstring(pkt, &str, &slen);
1416 blanks[nblanks].len = slen;
1421 log_packet(ssh->logctx, PKT_INCOMING, pkt->type,
1422 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->type),
1423 pkt->body, pkt->length, nblanks, blanks, &pkt->sequence,
1427 static void ssh2_log_outgoing_packet(Ssh ssh, struct Packet *pkt)
1430 struct logblank_t blanks[4];
1435 * For outgoing packets, pkt->length represents the length of the
1436 * whole packet starting at pkt->data (including some header), and
1437 * pkt->body refers to the point within that where the log-worthy
1438 * payload begins. However, incoming packets expect pkt->length to
1439 * represent only the payload length (that is, it's measured from
1440 * pkt->body not from pkt->data). Temporarily adjust our outgoing
1441 * packet to conform to the incoming-packet semantics, so that we
1442 * can analyse it with the ssh_pkt_get functions.
1444 pkt->length -= (pkt->body - pkt->data);
1447 if (ssh->logomitdata &&
1448 (pkt->type == SSH2_MSG_CHANNEL_DATA ||
1449 pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)) {
1450 /* "Session data" packets - omit the data string. */
1451 ssh_pkt_getuint32(pkt); /* skip channel id */
1452 if (pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)
1453 ssh_pkt_getuint32(pkt); /* skip extended data type */
1454 blanks[nblanks].offset = pkt->savedpos + 4;
1455 blanks[nblanks].type = PKTLOG_OMIT;
1456 ssh_pkt_getstring(pkt, &str, &slen);
1458 blanks[nblanks].len = slen;
1463 if (pkt->type == SSH2_MSG_USERAUTH_REQUEST &&
1464 conf_get_int(ssh->conf, CONF_logomitpass)) {
1465 /* If this is a password packet, blank the password(s). */
1467 ssh_pkt_getstring(pkt, &str, &slen);
1468 ssh_pkt_getstring(pkt, &str, &slen);
1469 ssh_pkt_getstring(pkt, &str, &slen);
1470 if (slen == 8 && !memcmp(str, "password", 8)) {
1471 ssh2_pkt_getbool(pkt);
1472 /* Blank the password field. */
1473 blanks[nblanks].offset = pkt->savedpos;
1474 blanks[nblanks].type = PKTLOG_BLANK;
1475 ssh_pkt_getstring(pkt, &str, &slen);
1477 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1479 /* If there's another password field beyond it (change of
1480 * password), blank that too. */
1481 ssh_pkt_getstring(pkt, &str, &slen);
1483 blanks[nblanks-1].len =
1484 pkt->savedpos - blanks[nblanks].offset;
1487 } else if (ssh->pkt_actx == SSH2_PKTCTX_KBDINTER &&
1488 pkt->type == SSH2_MSG_USERAUTH_INFO_RESPONSE &&
1489 conf_get_int(ssh->conf, CONF_logomitpass)) {
1490 /* If this is a keyboard-interactive response packet, blank
1493 ssh_pkt_getuint32(pkt);
1494 blanks[nblanks].offset = pkt->savedpos;
1495 blanks[nblanks].type = PKTLOG_BLANK;
1497 ssh_pkt_getstring(pkt, &str, &slen);
1501 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1503 } else if (pkt->type == SSH2_MSG_CHANNEL_REQUEST &&
1504 conf_get_int(ssh->conf, CONF_logomitpass)) {
1506 * If this is an X forwarding request packet, blank the fake
1509 * Note that while we blank the X authentication data here, we
1510 * don't take any special action to blank the start of an X11
1511 * channel, so using MIT-MAGIC-COOKIE-1 and actually opening
1512 * an X connection without having session blanking enabled is
1513 * likely to leak your cookie into the log.
1516 ssh_pkt_getuint32(pkt);
1517 ssh_pkt_getstring(pkt, &str, &slen);
1518 if (slen == 7 && !memcmp(str, "x11-req", 0)) {
1519 ssh2_pkt_getbool(pkt);
1520 ssh2_pkt_getbool(pkt);
1521 ssh_pkt_getstring(pkt, &str, &slen);
1522 blanks[nblanks].offset = pkt->savedpos;
1523 blanks[nblanks].type = PKTLOG_BLANK;
1524 ssh_pkt_getstring(pkt, &str, &slen);
1526 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1532 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1533 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]),
1534 pkt->body, pkt->length, nblanks, blanks,
1535 &ssh->v2_outgoing_sequence,
1536 pkt->downstream_id, pkt->additional_log_text);
1539 * Undo the above adjustment of pkt->length, to put the packet
1540 * back in the state we found it.
1542 pkt->length += (pkt->body - pkt->data);
1545 static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1547 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1549 crBegin(ssh->ssh2_rdpkt_crstate);
1551 st->pktin = ssh_new_packet();
1553 st->pktin->type = 0;
1554 st->pktin->length = 0;
1556 st->cipherblk = ssh->sccipher->blksize;
1559 if (st->cipherblk < 8)
1561 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1563 if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_IS_CBC) &&
1566 * When dealing with a CBC-mode cipher, we want to avoid the
1567 * possibility of an attacker's tweaking the ciphertext stream
1568 * so as to cause us to feed the same block to the block
1569 * cipher more than once and thus leak information
1570 * (VU#958563). The way we do this is not to take any
1571 * decisions on the basis of anything we've decrypted until
1572 * we've verified it with a MAC. That includes the packet
1573 * length, so we just read data and check the MAC repeatedly,
1574 * and when the MAC passes, see if the length we've got is
1578 /* May as well allocate the whole lot now. */
1579 st->pktin->data = snewn(OUR_V2_PACKETLIMIT + st->maclen + APIEXTRA,
1582 /* Read an amount corresponding to the MAC. */
1583 for (st->i = 0; st->i < st->maclen; st->i++) {
1584 while ((*datalen) == 0)
1586 st->pktin->data[st->i] = *(*data)++;
1592 unsigned char seq[4];
1593 ssh->scmac->start(ssh->sc_mac_ctx);
1594 PUT_32BIT(seq, st->incoming_sequence);
1595 ssh->scmac->bytes(ssh->sc_mac_ctx, seq, 4);
1598 for (;;) { /* Once around this loop per cipher block. */
1599 /* Read another cipher-block's worth, and tack it onto the end. */
1600 for (st->i = 0; st->i < st->cipherblk; st->i++) {
1601 while ((*datalen) == 0)
1603 st->pktin->data[st->packetlen+st->maclen+st->i] = *(*data)++;
1606 /* Decrypt one more block (a little further back in the stream). */
1607 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1608 st->pktin->data + st->packetlen,
1610 /* Feed that block to the MAC. */
1611 ssh->scmac->bytes(ssh->sc_mac_ctx,
1612 st->pktin->data + st->packetlen, st->cipherblk);
1613 st->packetlen += st->cipherblk;
1614 /* See if that gives us a valid packet. */
1615 if (ssh->scmac->verresult(ssh->sc_mac_ctx,
1616 st->pktin->data + st->packetlen) &&
1617 ((st->len = toint(GET_32BIT(st->pktin->data))) ==
1620 if (st->packetlen >= OUR_V2_PACKETLIMIT) {
1621 bombout(("No valid incoming packet found"));
1622 ssh_free_packet(st->pktin);
1626 st->pktin->maxlen = st->packetlen + st->maclen;
1627 st->pktin->data = sresize(st->pktin->data,
1628 st->pktin->maxlen + APIEXTRA,
1631 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1634 * Acquire and decrypt the first block of the packet. This will
1635 * contain the length and padding details.
1637 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1638 while ((*datalen) == 0)
1640 st->pktin->data[st->i] = *(*data)++;
1645 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1646 st->pktin->data, st->cipherblk);
1649 * Now get the length figure.
1651 st->len = toint(GET_32BIT(st->pktin->data));
1654 * _Completely_ silly lengths should be stomped on before they
1655 * do us any more damage.
1657 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1658 (st->len + 4) % st->cipherblk != 0) {
1659 bombout(("Incoming packet was garbled on decryption"));
1660 ssh_free_packet(st->pktin);
1665 * So now we can work out the total packet length.
1667 st->packetlen = st->len + 4;
1670 * Allocate memory for the rest of the packet.
1672 st->pktin->maxlen = st->packetlen + st->maclen;
1673 st->pktin->data = sresize(st->pktin->data,
1674 st->pktin->maxlen + APIEXTRA,
1678 * Read and decrypt the remainder of the packet.
1680 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1682 while ((*datalen) == 0)
1684 st->pktin->data[st->i] = *(*data)++;
1687 /* Decrypt everything _except_ the MAC. */
1689 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1690 st->pktin->data + st->cipherblk,
1691 st->packetlen - st->cipherblk);
1697 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1698 st->len + 4, st->incoming_sequence)) {
1699 bombout(("Incorrect MAC received on packet"));
1700 ssh_free_packet(st->pktin);
1704 /* Get and sanity-check the amount of random padding. */
1705 st->pad = st->pktin->data[4];
1706 if (st->pad < 4 || st->len - st->pad < 1) {
1707 bombout(("Invalid padding length on received packet"));
1708 ssh_free_packet(st->pktin);
1712 * This enables us to deduce the payload length.
1714 st->payload = st->len - st->pad - 1;
1716 st->pktin->length = st->payload + 5;
1717 st->pktin->encrypted_len = st->packetlen;
1719 st->pktin->sequence = st->incoming_sequence++;
1721 st->pktin->length = st->packetlen - st->pad;
1722 assert(st->pktin->length >= 0);
1725 * Decompress packet payload.
1728 unsigned char *newpayload;
1731 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1732 st->pktin->data + 5, st->pktin->length - 5,
1733 &newpayload, &newlen)) {
1734 if (st->pktin->maxlen < newlen + 5) {
1735 st->pktin->maxlen = newlen + 5;
1736 st->pktin->data = sresize(st->pktin->data,
1737 st->pktin->maxlen + APIEXTRA,
1740 st->pktin->length = 5 + newlen;
1741 memcpy(st->pktin->data + 5, newpayload, newlen);
1747 * pktin->body and pktin->length should identify the semantic
1748 * content of the packet, excluding the initial type byte.
1750 st->pktin->type = st->pktin->data[5];
1751 st->pktin->body = st->pktin->data + 6;
1752 st->pktin->length -= 6;
1753 assert(st->pktin->length >= 0); /* one last double-check */
1756 ssh2_log_incoming_packet(ssh, st->pktin);
1758 st->pktin->savedpos = 0;
1760 crFinish(st->pktin);
1763 static struct Packet *ssh2_bare_connection_rdpkt(Ssh ssh, unsigned char **data,
1766 struct rdpkt2_bare_state_tag *st = &ssh->rdpkt2_bare_state;
1768 crBegin(ssh->ssh2_bare_rdpkt_crstate);
1771 * Read the packet length field.
1773 for (st->i = 0; st->i < 4; st->i++) {
1774 while ((*datalen) == 0)
1776 st->length[st->i] = *(*data)++;
1780 st->packetlen = toint(GET_32BIT_MSB_FIRST(st->length));
1781 if (st->packetlen <= 0 || st->packetlen >= OUR_V2_PACKETLIMIT) {
1782 bombout(("Invalid packet length received"));
1786 st->pktin = ssh_new_packet();
1787 st->pktin->data = snewn(st->packetlen, unsigned char);
1789 st->pktin->encrypted_len = st->packetlen;
1791 st->pktin->sequence = st->incoming_sequence++;
1794 * Read the remainder of the packet.
1796 for (st->i = 0; st->i < st->packetlen; st->i++) {
1797 while ((*datalen) == 0)
1799 st->pktin->data[st->i] = *(*data)++;
1804 * pktin->body and pktin->length should identify the semantic
1805 * content of the packet, excluding the initial type byte.
1807 st->pktin->type = st->pktin->data[0];
1808 st->pktin->body = st->pktin->data + 1;
1809 st->pktin->length = st->packetlen - 1;
1812 * Log incoming packet, possibly omitting sensitive fields.
1815 ssh2_log_incoming_packet(ssh, st->pktin);
1817 st->pktin->savedpos = 0;
1819 crFinish(st->pktin);
1822 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1824 int pad, biglen, i, pktoffs;
1828 * XXX various versions of SC (including 8.8.4) screw up the
1829 * register allocation in this function and use the same register
1830 * (D6) for len and as a temporary, with predictable results. The
1831 * following sledgehammer prevents this.
1838 ssh1_log_outgoing_packet(ssh, pkt);
1840 if (ssh->v1_compressing) {
1841 unsigned char *compblk;
1843 zlib_compress_block(ssh->cs_comp_ctx,
1844 pkt->data + 12, pkt->length - 12,
1845 &compblk, &complen);
1846 ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */
1847 memcpy(pkt->data + 12, compblk, complen);
1849 pkt->length = complen + 12;
1852 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1854 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
1855 pad = 8 - (len % 8);
1857 biglen = len + pad; /* len(padding+type+data+CRC) */
1859 for (i = pktoffs; i < 4+8; i++)
1860 pkt->data[i] = random_byte();
1861 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1862 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1863 PUT_32BIT(pkt->data + pktoffs, len);
1866 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1867 pkt->data + pktoffs + 4, biglen);
1869 if (offset_p) *offset_p = pktoffs;
1870 return biglen + 4; /* len(length+padding+type+data+CRC) */
1873 static int s_write(Ssh ssh, void *data, int len)
1876 log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len,
1877 0, NULL, NULL, 0, NULL);
1880 return sk_write(ssh->s, (char *)data, len);
1883 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1885 int len, backlog, offset;
1886 len = s_wrpkt_prepare(ssh, pkt, &offset);
1887 backlog = s_write(ssh, pkt->data + offset, len);
1888 if (backlog > SSH_MAX_BACKLOG)
1889 ssh_throttle_all(ssh, 1, backlog);
1890 ssh_free_packet(pkt);
1893 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1896 len = s_wrpkt_prepare(ssh, pkt, &offset);
1897 if (ssh->deferred_len + len > ssh->deferred_size) {
1898 ssh->deferred_size = ssh->deferred_len + len + 128;
1899 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1903 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1904 pkt->data + offset, len);
1905 ssh->deferred_len += len;
1906 ssh_free_packet(pkt);
1910 * Construct a SSH-1 packet with the specified contents.
1911 * (This all-at-once interface used to be the only one, but now SSH-1
1912 * packets can also be constructed incrementally.)
1914 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
1920 pkt = ssh1_pkt_init(pkttype);
1922 while ((argtype = va_arg(ap, int)) != PKT_END) {
1923 unsigned char *argp, argchar;
1925 unsigned long argint;
1928 /* Actual fields in the packet */
1930 argint = va_arg(ap, int);
1931 ssh_pkt_adduint32(pkt, argint);
1934 argchar = (unsigned char) va_arg(ap, int);
1935 ssh_pkt_addbyte(pkt, argchar);
1938 argp = va_arg(ap, unsigned char *);
1939 arglen = va_arg(ap, int);
1940 ssh_pkt_adddata(pkt, argp, arglen);
1943 sargp = va_arg(ap, char *);
1944 ssh_pkt_addstring(pkt, sargp);
1947 bn = va_arg(ap, Bignum);
1948 ssh1_pkt_addmp(pkt, bn);
1956 static void send_packet(Ssh ssh, int pkttype, ...)
1960 va_start(ap, pkttype);
1961 pkt = construct_packet(ssh, pkttype, ap);
1966 static void defer_packet(Ssh ssh, int pkttype, ...)
1970 va_start(ap, pkttype);
1971 pkt = construct_packet(ssh, pkttype, ap);
1973 s_wrpkt_defer(ssh, pkt);
1976 static int ssh_versioncmp(char *a, char *b)
1979 unsigned long av, bv;
1981 av = strtoul(a, &ae, 10);
1982 bv = strtoul(b, &be, 10);
1984 return (av < bv ? -1 : +1);
1989 av = strtoul(ae, &ae, 10);
1990 bv = strtoul(be, &be, 10);
1992 return (av < bv ? -1 : +1);
1997 * Utility routines for putting an SSH-protocol `string' and
1998 * `uint32' into a hash state.
2000 static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
2002 unsigned char lenblk[4];
2003 PUT_32BIT(lenblk, len);
2004 h->bytes(s, lenblk, 4);
2005 h->bytes(s, str, len);
2008 static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
2010 unsigned char intblk[4];
2011 PUT_32BIT(intblk, i);
2012 h->bytes(s, intblk, 4);
2016 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
2018 static void ssh_pkt_ensure(struct Packet *pkt, int length)
2020 if (pkt->maxlen < length) {
2021 unsigned char *body = pkt->body;
2022 int offset = body ? body - pkt->data : 0;
2023 pkt->maxlen = length + 256;
2024 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
2025 if (body) pkt->body = pkt->data + offset;
2028 static void ssh_pkt_adddata(struct Packet *pkt, const void *data, int len)
2031 ssh_pkt_ensure(pkt, pkt->length);
2032 memcpy(pkt->data + pkt->length - len, data, len);
2034 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
2036 ssh_pkt_adddata(pkt, &byte, 1);
2038 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
2040 ssh_pkt_adddata(pkt, &value, 1);
2042 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
2045 PUT_32BIT(x, value);
2046 ssh_pkt_adddata(pkt, x, 4);
2048 static void ssh_pkt_addstring_start(struct Packet *pkt)
2050 ssh_pkt_adduint32(pkt, 0);
2051 pkt->savedpos = pkt->length;
2053 static void ssh_pkt_addstring_str(struct Packet *pkt, const char *data)
2055 ssh_pkt_adddata(pkt, data, strlen(data));
2056 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
2058 static void ssh_pkt_addstring_data(struct Packet *pkt, const char *data,
2061 ssh_pkt_adddata(pkt, data, len);
2062 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
2064 static void ssh_pkt_addstring(struct Packet *pkt, const char *data)
2066 ssh_pkt_addstring_start(pkt);
2067 ssh_pkt_addstring_str(pkt, data);
2069 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
2071 int len = ssh1_bignum_length(b);
2072 unsigned char *data = snewn(len, unsigned char);
2073 (void) ssh1_write_bignum(data, b);
2074 ssh_pkt_adddata(pkt, data, len);
2077 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
2080 int i, n = (bignum_bitcount(b) + 7) / 8;
2081 p = snewn(n + 1, unsigned char);
2083 for (i = 1; i <= n; i++)
2084 p[i] = bignum_byte(b, n - i);
2086 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
2088 memmove(p, p + i, n + 1 - i);
2092 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
2096 p = ssh2_mpint_fmt(b, &len);
2097 ssh_pkt_addstring_start(pkt);
2098 ssh_pkt_addstring_data(pkt, (char *)p, len);
2102 static struct Packet *ssh1_pkt_init(int pkt_type)
2104 struct Packet *pkt = ssh_new_packet();
2105 pkt->length = 4 + 8; /* space for length + max padding */
2106 ssh_pkt_addbyte(pkt, pkt_type);
2107 pkt->body = pkt->data + pkt->length;
2108 pkt->type = pkt_type;
2109 pkt->downstream_id = 0;
2110 pkt->additional_log_text = NULL;
2114 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
2115 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
2116 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
2117 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
2118 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
2119 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
2120 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
2121 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
2122 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
2124 static struct Packet *ssh2_pkt_init(int pkt_type)
2126 struct Packet *pkt = ssh_new_packet();
2127 pkt->length = 5; /* space for packet length + padding length */
2129 pkt->type = pkt_type;
2130 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
2131 pkt->body = pkt->data + pkt->length; /* after packet type */
2132 pkt->downstream_id = 0;
2133 pkt->additional_log_text = NULL;
2138 * Construct an SSH-2 final-form packet: compress it, encrypt it,
2139 * put the MAC on it. Final packet, ready to be sent, is stored in
2140 * pkt->data. Total length is returned.
2142 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
2144 int cipherblk, maclen, padding, i;
2147 ssh2_log_outgoing_packet(ssh, pkt);
2149 if (ssh->bare_connection) {
2151 * Trivial packet construction for the bare connection
2154 PUT_32BIT(pkt->data + 1, pkt->length - 5);
2155 pkt->body = pkt->data + 1;
2156 ssh->v2_outgoing_sequence++; /* only for diagnostics, really */
2157 return pkt->length - 1;
2161 * Compress packet payload.
2164 unsigned char *newpayload;
2167 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
2169 &newpayload, &newlen)) {
2171 ssh2_pkt_adddata(pkt, newpayload, newlen);
2177 * Add padding. At least four bytes, and must also bring total
2178 * length (minus MAC) up to a multiple of the block size.
2179 * If pkt->forcepad is set, make sure the packet is at least that size
2182 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
2183 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
2185 if (pkt->length + padding < pkt->forcepad)
2186 padding = pkt->forcepad - pkt->length;
2188 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
2189 assert(padding <= 255);
2190 maclen = ssh->csmac ? ssh->csmac->len : 0;
2191 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
2192 pkt->data[4] = padding;
2193 for (i = 0; i < padding; i++)
2194 pkt->data[pkt->length + i] = random_byte();
2195 PUT_32BIT(pkt->data, pkt->length + padding - 4);
2197 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
2198 pkt->length + padding,
2199 ssh->v2_outgoing_sequence);
2200 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
2203 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
2204 pkt->data, pkt->length + padding);
2206 pkt->encrypted_len = pkt->length + padding;
2208 /* Ready-to-send packet starts at pkt->data. We return length. */
2209 pkt->body = pkt->data;
2210 return pkt->length + padding + maclen;
2214 * Routines called from the main SSH code to send packets. There
2215 * are quite a few of these, because we have two separate
2216 * mechanisms for delaying the sending of packets:
2218 * - In order to send an IGNORE message and a password message in
2219 * a single fixed-length blob, we require the ability to
2220 * concatenate the encrypted forms of those two packets _into_ a
2221 * single blob and then pass it to our <network.h> transport
2222 * layer in one go. Hence, there's a deferment mechanism which
2223 * works after packet encryption.
2225 * - In order to avoid sending any connection-layer messages
2226 * during repeat key exchange, we have to queue up any such
2227 * outgoing messages _before_ they are encrypted (and in
2228 * particular before they're allocated sequence numbers), and
2229 * then send them once we've finished.
2231 * I call these mechanisms `defer' and `queue' respectively, so as
2232 * to distinguish them reasonably easily.
2234 * The functions send_noqueue() and defer_noqueue() free the packet
2235 * structure they are passed. Every outgoing packet goes through
2236 * precisely one of these functions in its life; packets passed to
2237 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
2238 * these or get queued, and then when the queue is later emptied
2239 * the packets are all passed to defer_noqueue().
2241 * When using a CBC-mode cipher, it's necessary to ensure that an
2242 * attacker can't provide data to be encrypted using an IV that they
2243 * know. We ensure this by prefixing each packet that might contain
2244 * user data with an SSH_MSG_IGNORE. This is done using the deferral
2245 * mechanism, so in this case send_noqueue() ends up redirecting to
2246 * defer_noqueue(). If you don't like this inefficiency, don't use
2250 static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
2251 static void ssh_pkt_defersend(Ssh);
2254 * Send an SSH-2 packet immediately, without queuing or deferring.
2256 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
2260 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
2261 /* We need to send two packets, so use the deferral mechanism. */
2262 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2263 ssh_pkt_defersend(ssh);
2266 len = ssh2_pkt_construct(ssh, pkt);
2267 backlog = s_write(ssh, pkt->body, len);
2268 if (backlog > SSH_MAX_BACKLOG)
2269 ssh_throttle_all(ssh, 1, backlog);
2271 ssh->outgoing_data_size += pkt->encrypted_len;
2272 if (!ssh->kex_in_progress &&
2273 !ssh->bare_connection &&
2274 ssh->max_data_size != 0 &&
2275 ssh->outgoing_data_size > ssh->max_data_size)
2276 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2278 ssh_free_packet(pkt);
2282 * Defer an SSH-2 packet.
2284 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
2287 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
2288 ssh->deferred_len == 0 && !noignore &&
2289 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2291 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2292 * get encrypted with a known IV.
2294 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2295 ssh2_pkt_addstring_start(ipkt);
2296 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
2298 len = ssh2_pkt_construct(ssh, pkt);
2299 if (ssh->deferred_len + len > ssh->deferred_size) {
2300 ssh->deferred_size = ssh->deferred_len + len + 128;
2301 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2305 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->body, len);
2306 ssh->deferred_len += len;
2307 ssh->deferred_data_size += pkt->encrypted_len;
2308 ssh_free_packet(pkt);
2312 * Queue an SSH-2 packet.
2314 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
2316 assert(ssh->queueing);
2318 if (ssh->queuelen >= ssh->queuesize) {
2319 ssh->queuesize = ssh->queuelen + 32;
2320 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
2323 ssh->queue[ssh->queuelen++] = pkt;
2327 * Either queue or send a packet, depending on whether queueing is
2330 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
2333 ssh2_pkt_queue(ssh, pkt);
2335 ssh2_pkt_send_noqueue(ssh, pkt);
2339 * Either queue or defer a packet, depending on whether queueing is
2342 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
2345 ssh2_pkt_queue(ssh, pkt);
2347 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2351 * Send the whole deferred data block constructed by
2352 * ssh2_pkt_defer() or SSH-1's defer_packet().
2354 * The expected use of the defer mechanism is that you call
2355 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2356 * not currently queueing, this simply sets up deferred_send_data
2357 * and then sends it. If we _are_ currently queueing, the calls to
2358 * ssh2_pkt_defer() put the deferred packets on to the queue
2359 * instead, and therefore ssh_pkt_defersend() has no deferred data
2360 * to send. Hence, there's no need to make it conditional on
2363 static void ssh_pkt_defersend(Ssh ssh)
2366 backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
2367 ssh->deferred_len = ssh->deferred_size = 0;
2368 sfree(ssh->deferred_send_data);
2369 ssh->deferred_send_data = NULL;
2370 if (backlog > SSH_MAX_BACKLOG)
2371 ssh_throttle_all(ssh, 1, backlog);
2373 ssh->outgoing_data_size += ssh->deferred_data_size;
2374 if (!ssh->kex_in_progress &&
2375 !ssh->bare_connection &&
2376 ssh->max_data_size != 0 &&
2377 ssh->outgoing_data_size > ssh->max_data_size)
2378 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2379 ssh->deferred_data_size = 0;
2383 * Send a packet whose length needs to be disguised (typically
2384 * passwords or keyboard-interactive responses).
2386 static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
2392 * The simplest way to do this is to adjust the
2393 * variable-length padding field in the outgoing packet.
2395 * Currently compiled out, because some Cisco SSH servers
2396 * don't like excessively padded packets (bah, why's it
2399 pkt->forcepad = padsize;
2400 ssh2_pkt_send(ssh, pkt);
2405 * If we can't do that, however, an alternative approach is
2406 * to use the pkt_defer mechanism to bundle the packet
2407 * tightly together with an SSH_MSG_IGNORE such that their
2408 * combined length is a constant. So first we construct the
2409 * final form of this packet and defer its sending.
2411 ssh2_pkt_defer(ssh, pkt);
2414 * Now construct an SSH_MSG_IGNORE which includes a string
2415 * that's an exact multiple of the cipher block size. (If
2416 * the cipher is NULL so that the block size is
2417 * unavailable, we don't do this trick at all, because we
2418 * gain nothing by it.)
2420 if (ssh->cscipher &&
2421 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2424 stringlen = (256 - ssh->deferred_len);
2425 stringlen += ssh->cscipher->blksize - 1;
2426 stringlen -= (stringlen % ssh->cscipher->blksize);
2429 * Temporarily disable actual compression, so we
2430 * can guarantee to get this string exactly the
2431 * length we want it. The compression-disabling
2432 * routine should return an integer indicating how
2433 * many bytes we should adjust our string length
2437 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
2439 pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2440 ssh2_pkt_addstring_start(pkt);
2441 for (i = 0; i < stringlen; i++) {
2442 char c = (char) random_byte();
2443 ssh2_pkt_addstring_data(pkt, &c, 1);
2445 ssh2_pkt_defer(ssh, pkt);
2447 ssh_pkt_defersend(ssh);
2452 * Send all queued SSH-2 packets. We send them by means of
2453 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2454 * packets that needed to be lumped together.
2456 static void ssh2_pkt_queuesend(Ssh ssh)
2460 assert(!ssh->queueing);
2462 for (i = 0; i < ssh->queuelen; i++)
2463 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
2466 ssh_pkt_defersend(ssh);
2470 void bndebug(char *string, Bignum b)
2474 p = ssh2_mpint_fmt(b, &len);
2475 debug(("%s", string));
2476 for (i = 0; i < len; i++)
2477 debug((" %02x", p[i]));
2483 static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
2487 p = ssh2_mpint_fmt(b, &len);
2488 hash_string(h, s, p, len);
2493 * Packet decode functions for both SSH-1 and SSH-2.
2495 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
2497 unsigned long value;
2498 if (pkt->length - pkt->savedpos < 4)
2499 return 0; /* arrgh, no way to decline (FIXME?) */
2500 value = GET_32BIT(pkt->body + pkt->savedpos);
2504 static int ssh2_pkt_getbool(struct Packet *pkt)
2506 unsigned long value;
2507 if (pkt->length - pkt->savedpos < 1)
2508 return 0; /* arrgh, no way to decline (FIXME?) */
2509 value = pkt->body[pkt->savedpos] != 0;
2513 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
2518 if (pkt->length - pkt->savedpos < 4)
2520 len = toint(GET_32BIT(pkt->body + pkt->savedpos));
2525 if (pkt->length - pkt->savedpos < *length)
2527 *p = (char *)(pkt->body + pkt->savedpos);
2528 pkt->savedpos += *length;
2530 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
2532 if (pkt->length - pkt->savedpos < length)
2534 pkt->savedpos += length;
2535 return pkt->body + (pkt->savedpos - length);
2537 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2538 unsigned char **keystr)
2542 j = makekey(pkt->body + pkt->savedpos,
2543 pkt->length - pkt->savedpos,
2550 assert(pkt->savedpos < pkt->length);
2554 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2559 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2560 pkt->length - pkt->savedpos, &b);
2568 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2574 ssh_pkt_getstring(pkt, &p, &length);
2579 b = bignum_from_bytes((unsigned char *)p, length);
2584 * Helper function to add an SSH-2 signature blob to a packet.
2585 * Expects to be shown the public key blob as well as the signature
2586 * blob. Normally works just like ssh2_pkt_addstring, but will
2587 * fiddle with the signature packet if necessary for
2588 * BUG_SSH2_RSA_PADDING.
2590 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2591 void *pkblob_v, int pkblob_len,
2592 void *sigblob_v, int sigblob_len)
2594 unsigned char *pkblob = (unsigned char *)pkblob_v;
2595 unsigned char *sigblob = (unsigned char *)sigblob_v;
2597 /* dmemdump(pkblob, pkblob_len); */
2598 /* dmemdump(sigblob, sigblob_len); */
2601 * See if this is in fact an ssh-rsa signature and a buggy
2602 * server; otherwise we can just do this the easy way.
2604 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) && pkblob_len > 4+7+4 &&
2605 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2606 int pos, len, siglen;
2609 * Find the byte length of the modulus.
2612 pos = 4+7; /* skip over "ssh-rsa" */
2613 len = toint(GET_32BIT(pkblob+pos)); /* get length of exponent */
2614 if (len < 0 || len > pkblob_len - pos - 4)
2616 pos += 4 + len; /* skip over exponent */
2617 if (pkblob_len - pos < 4)
2619 len = toint(GET_32BIT(pkblob+pos)); /* find length of modulus */
2620 if (len < 0 || len > pkblob_len - pos - 4)
2622 pos += 4; /* find modulus itself */
2623 while (len > 0 && pkblob[pos] == 0)
2625 /* debug(("modulus length is %d\n", len)); */
2628 * Now find the signature integer.
2630 pos = 4+7; /* skip over "ssh-rsa" */
2631 if (sigblob_len < pos+4)
2633 siglen = toint(GET_32BIT(sigblob+pos));
2634 if (siglen != sigblob_len - pos - 4)
2636 /* debug(("signature length is %d\n", siglen)); */
2638 if (len != siglen) {
2639 unsigned char newlen[4];
2640 ssh2_pkt_addstring_start(pkt);
2641 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2642 /* dmemdump(sigblob, pos); */
2643 pos += 4; /* point to start of actual sig */
2644 PUT_32BIT(newlen, len);
2645 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2646 /* dmemdump(newlen, 4); */
2648 while (len-- > siglen) {
2649 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2650 /* dmemdump(newlen, 1); */
2652 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2653 /* dmemdump(sigblob+pos, siglen); */
2657 /* Otherwise fall through and do it the easy way. We also come
2658 * here as a fallback if we discover above that the key blob
2659 * is misformatted in some way. */
2663 ssh2_pkt_addstring_start(pkt);
2664 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2668 * Examine the remote side's version string and compare it against
2669 * a list of known buggy implementations.
2671 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2673 char *imp; /* pointer to implementation part */
2675 imp += strcspn(imp, "-");
2677 imp += strcspn(imp, "-");
2680 ssh->remote_bugs = 0;
2683 * General notes on server version strings:
2684 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2685 * here -- in particular, we've heard of one that's perfectly happy
2686 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2687 * so we can't distinguish them.
2689 if (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == FORCE_ON ||
2690 (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == AUTO &&
2691 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2692 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2693 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2694 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2696 * These versions don't support SSH1_MSG_IGNORE, so we have
2697 * to use a different defence against password length
2700 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2701 logevent("We believe remote version has SSH-1 ignore bug");
2704 if (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == FORCE_ON ||
2705 (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == AUTO &&
2706 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2708 * These versions need a plain password sent; they can't
2709 * handle having a null and a random length of data after
2712 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2713 logevent("We believe remote version needs a plain SSH-1 password");
2716 if (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == FORCE_ON ||
2717 (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == AUTO &&
2718 (!strcmp(imp, "Cisco-1.25")))) {
2720 * These versions apparently have no clue whatever about
2721 * RSA authentication and will panic and die if they see
2722 * an AUTH_RSA message.
2724 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2725 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2728 if (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == FORCE_ON ||
2729 (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == AUTO &&
2730 !wc_match("* VShell", imp) &&
2731 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2732 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2733 wc_match("2.1 *", imp)))) {
2735 * These versions have the HMAC bug.
2737 ssh->remote_bugs |= BUG_SSH2_HMAC;
2738 logevent("We believe remote version has SSH-2 HMAC bug");
2741 if (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == FORCE_ON ||
2742 (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == AUTO &&
2743 !wc_match("* VShell", imp) &&
2744 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2746 * These versions have the key-derivation bug (failing to
2747 * include the literal shared secret in the hashes that
2748 * generate the keys).
2750 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2751 logevent("We believe remote version has SSH-2 key-derivation bug");
2754 if (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == FORCE_ON ||
2755 (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == AUTO &&
2756 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2757 wc_match("OpenSSH_3.[0-2]*", imp) ||
2758 wc_match("mod_sftp/0.[0-8]*", imp) ||
2759 wc_match("mod_sftp/0.9.[0-8]", imp)))) {
2761 * These versions have the SSH-2 RSA padding bug.
2763 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2764 logevent("We believe remote version has SSH-2 RSA padding bug");
2767 if (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == FORCE_ON ||
2768 (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == AUTO &&
2769 wc_match("OpenSSH_2.[0-2]*", imp))) {
2771 * These versions have the SSH-2 session-ID bug in
2772 * public-key authentication.
2774 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2775 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2778 if (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == FORCE_ON ||
2779 (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == AUTO &&
2780 (wc_match("DigiSSH_2.0", imp) ||
2781 wc_match("OpenSSH_2.[0-4]*", imp) ||
2782 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2783 wc_match("Sun_SSH_1.0", imp) ||
2784 wc_match("Sun_SSH_1.0.1", imp) ||
2785 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2786 wc_match("WeOnlyDo-*", imp)))) {
2788 * These versions have the SSH-2 rekey bug.
2790 ssh->remote_bugs |= BUG_SSH2_REKEY;
2791 logevent("We believe remote version has SSH-2 rekey bug");
2794 if (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == FORCE_ON ||
2795 (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == AUTO &&
2796 (wc_match("1.36_sshlib GlobalSCAPE", imp) ||
2797 wc_match("1.36 sshlib: GlobalScape", imp)))) {
2799 * This version ignores our makpkt and needs to be throttled.
2801 ssh->remote_bugs |= BUG_SSH2_MAXPKT;
2802 logevent("We believe remote version ignores SSH-2 maximum packet size");
2805 if (conf_get_int(ssh->conf, CONF_sshbug_ignore2) == FORCE_ON) {
2807 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2808 * none detected automatically.
2810 ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE;
2811 logevent("We believe remote version has SSH-2 ignore bug");
2814 if (conf_get_int(ssh->conf, CONF_sshbug_winadj) == FORCE_ON) {
2816 * Servers that don't support our winadj request for one
2817 * reason or another. Currently, none detected automatically.
2819 ssh->remote_bugs |= BUG_CHOKES_ON_WINADJ;
2820 logevent("We believe remote version has winadj bug");
2823 if (conf_get_int(ssh->conf, CONF_sshbug_chanreq) == FORCE_ON ||
2824 (conf_get_int(ssh->conf, CONF_sshbug_chanreq) == AUTO &&
2825 (wc_match("OpenSSH_[2-5].*", imp) ||
2826 wc_match("OpenSSH_6.[0-6]*", imp)))) {
2828 * These versions have the SSH-2 channel request bug. 6.7 and
2830 * https://bugzilla.mindrot.org/show_bug.cgi?id=1818
2832 ssh->remote_bugs |= BUG_SENDS_LATE_REQUEST_REPLY;
2833 logevent("We believe remote version has SSH-2 channel request bug");
2838 * The `software version' part of an SSH version string is required
2839 * to contain no spaces or minus signs.
2841 static void ssh_fix_verstring(char *str)
2843 /* Eat "<protoversion>-". */
2844 while (*str && *str != '-') str++;
2845 assert(*str == '-'); str++;
2847 /* Convert minus signs and spaces in the remaining string into
2850 if (*str == '-' || *str == ' ')
2857 * Send an appropriate SSH version string.
2859 static void ssh_send_verstring(Ssh ssh, const char *protoname, char *svers)
2863 if (ssh->version == 2) {
2865 * Construct a v2 version string.
2867 verstring = dupprintf("%s2.0-%s\015\012", protoname, sshver);
2870 * Construct a v1 version string.
2872 assert(!strcmp(protoname, "SSH-")); /* no v1 bare connection protocol */
2873 verstring = dupprintf("SSH-%s-%s\012",
2874 (ssh_versioncmp(svers, "1.5") <= 0 ?
2879 ssh_fix_verstring(verstring + strlen(protoname));
2881 if (ssh->version == 2) {
2884 * Record our version string.
2886 len = strcspn(verstring, "\015\012");
2887 ssh->v_c = snewn(len + 1, char);
2888 memcpy(ssh->v_c, verstring, len);
2892 logeventf(ssh, "We claim version: %.*s",
2893 strcspn(verstring, "\015\012"), verstring);
2894 s_write(ssh, verstring, strlen(verstring));
2898 static int do_ssh_init(Ssh ssh, unsigned char c)
2900 static const char protoname[] = "SSH-";
2902 struct do_ssh_init_state {
2911 crState(do_ssh_init_state);
2915 /* Search for a line beginning with the protocol name prefix in
2918 for (s->i = 0; protoname[s->i]; s->i++) {
2919 if ((char)c != protoname[s->i]) goto no;
2929 s->vstrsize = sizeof(protoname) + 16;
2930 s->vstring = snewn(s->vstrsize, char);
2931 strcpy(s->vstring, protoname);
2932 s->vslen = strlen(protoname);
2935 if (s->vslen >= s->vstrsize - 1) {
2937 s->vstring = sresize(s->vstring, s->vstrsize, char);
2939 s->vstring[s->vslen++] = c;
2942 s->version[s->i] = '\0';
2944 } else if (s->i < sizeof(s->version) - 1)
2945 s->version[s->i++] = c;
2946 } else if (c == '\012')
2948 crReturn(1); /* get another char */
2951 ssh->agentfwd_enabled = FALSE;
2952 ssh->rdpkt2_state.incoming_sequence = 0;
2954 s->vstring[s->vslen] = 0;
2955 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2956 logeventf(ssh, "Server version: %s", s->vstring);
2957 ssh_detect_bugs(ssh, s->vstring);
2960 * Decide which SSH protocol version to support.
2963 /* Anything strictly below "2.0" means protocol 1 is supported. */
2964 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2965 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2966 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2968 if (conf_get_int(ssh->conf, CONF_sshprot) == 0 && !s->proto1) {
2969 bombout(("SSH protocol version 1 required by configuration but "
2970 "not provided by server"));
2973 if (conf_get_int(ssh->conf, CONF_sshprot) == 3 && !s->proto2) {
2974 bombout(("SSH protocol version 2 required by configuration but "
2975 "not provided by server"));
2979 if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1))
2984 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2986 /* Send the version string, if we haven't already */
2987 if (conf_get_int(ssh->conf, CONF_sshprot) != 3)
2988 ssh_send_verstring(ssh, protoname, s->version);
2990 if (ssh->version == 2) {
2993 * Record their version string.
2995 len = strcspn(s->vstring, "\015\012");
2996 ssh->v_s = snewn(len + 1, char);
2997 memcpy(ssh->v_s, s->vstring, len);
3001 * Initialise SSH-2 protocol.
3003 ssh->protocol = ssh2_protocol;
3004 ssh2_protocol_setup(ssh);
3005 ssh->s_rdpkt = ssh2_rdpkt;
3008 * Initialise SSH-1 protocol.
3010 ssh->protocol = ssh1_protocol;
3011 ssh1_protocol_setup(ssh);
3012 ssh->s_rdpkt = ssh1_rdpkt;
3014 if (ssh->version == 2)
3015 do_ssh2_transport(ssh, NULL, -1, NULL);
3017 update_specials_menu(ssh->frontend);
3018 ssh->state = SSH_STATE_BEFORE_SIZE;
3019 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3026 static int do_ssh_connection_init(Ssh ssh, unsigned char c)
3029 * Ordinary SSH begins with the banner "SSH-x.y-...". This is just
3030 * the ssh-connection part, extracted and given a trivial binary
3031 * packet protocol, so we replace 'SSH-' at the start with a new
3032 * name. In proper SSH style (though of course this part of the
3033 * proper SSH protocol _isn't_ subject to this kind of
3034 * DNS-domain-based extension), we define the new name in our
3037 static const char protoname[] =
3038 "SSHCONNECTION@putty.projects.tartarus.org-";
3040 struct do_ssh_connection_init_state {
3048 crState(do_ssh_connection_init_state);
3052 /* Search for a line beginning with the protocol name prefix in
3055 for (s->i = 0; protoname[s->i]; s->i++) {
3056 if ((char)c != protoname[s->i]) goto no;
3066 s->vstrsize = sizeof(protoname) + 16;
3067 s->vstring = snewn(s->vstrsize, char);
3068 strcpy(s->vstring, protoname);
3069 s->vslen = strlen(protoname);
3072 if (s->vslen >= s->vstrsize - 1) {
3074 s->vstring = sresize(s->vstring, s->vstrsize, char);
3076 s->vstring[s->vslen++] = c;
3079 s->version[s->i] = '\0';
3081 } else if (s->i < sizeof(s->version) - 1)
3082 s->version[s->i++] = c;
3083 } else if (c == '\012')
3085 crReturn(1); /* get another char */
3088 ssh->agentfwd_enabled = FALSE;
3089 ssh->rdpkt2_bare_state.incoming_sequence = 0;
3091 s->vstring[s->vslen] = 0;
3092 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
3093 logeventf(ssh, "Server version: %s", s->vstring);
3094 ssh_detect_bugs(ssh, s->vstring);
3097 * Decide which SSH protocol version to support. This is easy in
3098 * bare ssh-connection mode: only 2.0 is legal.
3100 if (ssh_versioncmp(s->version, "2.0") < 0) {
3101 bombout(("Server announces compatibility with SSH-1 in bare ssh-connection protocol"));
3104 if (conf_get_int(ssh->conf, CONF_sshprot) == 0) {
3105 bombout(("Bare ssh-connection protocol cannot be run in SSH-1-only mode"));
3111 logeventf(ssh, "Using bare ssh-connection protocol");
3113 /* Send the version string, if we haven't already */
3114 ssh_send_verstring(ssh, protoname, s->version);
3117 * Initialise bare connection protocol.
3119 ssh->protocol = ssh2_bare_connection_protocol;
3120 ssh2_bare_connection_protocol_setup(ssh);
3121 ssh->s_rdpkt = ssh2_bare_connection_rdpkt;
3123 update_specials_menu(ssh->frontend);
3124 ssh->state = SSH_STATE_BEFORE_SIZE;
3125 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3128 * Get authconn (really just conn) under way.
3130 do_ssh2_authconn(ssh, NULL, 0, NULL);
3137 static void ssh_process_incoming_data(Ssh ssh,
3138 unsigned char **data, int *datalen)
3140 struct Packet *pktin;
3142 pktin = ssh->s_rdpkt(ssh, data, datalen);
3144 ssh->protocol(ssh, NULL, 0, pktin);
3145 ssh_free_packet(pktin);
3149 static void ssh_queue_incoming_data(Ssh ssh,
3150 unsigned char **data, int *datalen)
3152 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
3157 static void ssh_process_queued_incoming_data(Ssh ssh)
3160 unsigned char *data;
3163 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
3164 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
3168 while (!ssh->frozen && len > 0)
3169 ssh_process_incoming_data(ssh, &data, &len);
3172 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
3176 static void ssh_set_frozen(Ssh ssh, int frozen)
3179 sk_set_frozen(ssh->s, frozen);
3180 ssh->frozen = frozen;
3183 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
3185 /* Log raw data, if we're in that mode. */
3187 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
3188 0, NULL, NULL, 0, NULL);
3190 crBegin(ssh->ssh_gotdata_crstate);
3193 * To begin with, feed the characters one by one to the
3194 * protocol initialisation / selection function do_ssh_init().
3195 * When that returns 0, we're done with the initial greeting
3196 * exchange and can move on to packet discipline.
3199 int ret; /* need not be kept across crReturn */
3201 crReturnV; /* more data please */
3202 ret = ssh->do_ssh_init(ssh, *data);
3210 * We emerge from that loop when the initial negotiation is
3211 * over and we have selected an s_rdpkt function. Now pass
3212 * everything to s_rdpkt, and then pass the resulting packets
3213 * to the proper protocol handler.
3217 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
3219 ssh_queue_incoming_data(ssh, &data, &datalen);
3220 /* This uses up all data and cannot cause anything interesting
3221 * to happen; indeed, for anything to happen at all, we must
3222 * return, so break out. */
3224 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
3225 /* This uses up some or all data, and may freeze the
3227 ssh_process_queued_incoming_data(ssh);
3229 /* This uses up some or all data, and may freeze the
3231 ssh_process_incoming_data(ssh, &data, &datalen);
3233 /* FIXME this is probably EBW. */
3234 if (ssh->state == SSH_STATE_CLOSED)
3237 /* We're out of data. Go and get some more. */
3243 static int ssh_do_close(Ssh ssh, int notify_exit)
3246 struct ssh_channel *c;
3248 ssh->state = SSH_STATE_CLOSED;
3249 expire_timer_context(ssh);
3254 notify_remote_exit(ssh->frontend);
3259 * Now we must shut down any port- and X-forwarded channels going
3260 * through this connection.
3262 if (ssh->channels) {
3263 while (NULL != (c = index234(ssh->channels, 0))) {
3266 x11_close(c->u.x11.xconn);
3269 case CHAN_SOCKDATA_DORMANT:
3270 pfd_close(c->u.pfd.pf);
3273 del234(ssh->channels, c); /* moving next one to index 0 */
3274 if (ssh->version == 2)
3275 bufchain_clear(&c->v.v2.outbuffer);
3280 * Go through port-forwardings, and close any associated
3281 * listening sockets.
3283 if (ssh->portfwds) {
3284 struct ssh_portfwd *pf;
3285 while (NULL != (pf = index234(ssh->portfwds, 0))) {
3286 /* Dispose of any listening socket. */
3288 pfl_terminate(pf->local);
3289 del234(ssh->portfwds, pf); /* moving next one to index 0 */
3292 freetree234(ssh->portfwds);
3293 ssh->portfwds = NULL;
3297 * Also stop attempting to connection-share.
3299 if (ssh->connshare) {
3300 sharestate_free(ssh->connshare);
3301 ssh->connshare = NULL;
3307 static void ssh_socket_log(Plug plug, int type, SockAddr addr, int port,
3308 const char *error_msg, int error_code)
3310 Ssh ssh = (Ssh) plug;
3311 char addrbuf[256], *msg;
3313 if (ssh->attempting_connshare) {
3315 * While we're attempting connection sharing, don't loudly log
3316 * everything that happens. Real TCP connections need to be
3317 * logged when we _start_ trying to connect, because it might
3318 * be ages before they respond if something goes wrong; but
3319 * connection sharing is local and quick to respond, and it's
3320 * sufficient to simply wait and see whether it worked
3324 sk_getaddr(addr, addrbuf, lenof(addrbuf));
3327 if (sk_addr_needs_port(addr)) {
3328 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
3330 msg = dupprintf("Connecting to %s", addrbuf);
3333 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
3341 void ssh_connshare_log(Ssh ssh, int event, const char *logtext,
3342 const char *ds_err, const char *us_err)
3344 if (event == SHARE_NONE) {
3345 /* In this case, 'logtext' is an error message indicating a
3346 * reason why connection sharing couldn't be set up _at all_.
3347 * Failing that, ds_err and us_err indicate why we couldn't be
3348 * a downstream and an upstream respectively. */
3350 logeventf(ssh, "Could not set up connection sharing: %s", logtext);
3353 logeventf(ssh, "Could not set up connection sharing"
3354 " as downstream: %s", ds_err);
3356 logeventf(ssh, "Could not set up connection sharing"
3357 " as upstream: %s", us_err);
3359 } else if (event == SHARE_DOWNSTREAM) {
3360 /* In this case, 'logtext' is a local endpoint address */
3361 logeventf(ssh, "Using existing shared connection at %s", logtext);
3362 /* Also we should mention this in the console window to avoid
3363 * confusing users as to why this window doesn't behave the
3365 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3366 c_write_str(ssh,"Reusing a shared connection to this server.\r\n");
3368 } else if (event == SHARE_UPSTREAM) {
3369 /* In this case, 'logtext' is a local endpoint address too */
3370 logeventf(ssh, "Sharing this connection at %s", logtext);
3374 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
3377 Ssh ssh = (Ssh) plug;
3378 int need_notify = ssh_do_close(ssh, FALSE);
3381 if (!ssh->close_expected)
3382 error_msg = "Server unexpectedly closed network connection";
3384 error_msg = "Server closed network connection";
3387 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
3391 notify_remote_exit(ssh->frontend);
3394 logevent(error_msg);
3395 if (!ssh->close_expected || !ssh->clean_exit)
3396 connection_fatal(ssh->frontend, "%s", error_msg);
3400 static int ssh_receive(Plug plug, int urgent, char *data, int len)
3402 Ssh ssh = (Ssh) plug;
3403 ssh_gotdata(ssh, (unsigned char *)data, len);
3404 if (ssh->state == SSH_STATE_CLOSED) {
3405 ssh_do_close(ssh, TRUE);
3411 static void ssh_sent(Plug plug, int bufsize)
3413 Ssh ssh = (Ssh) plug;
3415 * If the send backlog on the SSH socket itself clears, we
3416 * should unthrottle the whole world if it was throttled.
3418 if (bufsize < SSH_MAX_BACKLOG)
3419 ssh_throttle_all(ssh, 0, bufsize);
3423 * Connect to specified host and port.
3424 * Returns an error message, or NULL on success.
3425 * Also places the canonical host name into `realhost'. It must be
3426 * freed by the caller.
3428 static const char *connect_to_host(Ssh ssh, char *host, int port,
3429 char **realhost, int nodelay, int keepalive)
3431 static const struct plug_function_table fn_table = {
3442 int addressfamily, sshprot;
3444 loghost = conf_get_str(ssh->conf, CONF_loghost);
3449 tmphost = dupstr(loghost);
3450 ssh->savedport = 22; /* default ssh port */
3453 * A colon suffix on the hostname string also lets us affect
3454 * savedport. (Unless there are multiple colons, in which case
3455 * we assume this is an unbracketed IPv6 literal.)
3457 colon = host_strrchr(tmphost, ':');
3458 if (colon && colon == host_strchr(tmphost, ':')) {
3461 ssh->savedport = atoi(colon);
3464 ssh->savedhost = host_strduptrim(tmphost);
3467 ssh->savedhost = host_strduptrim(host);
3469 port = 22; /* default ssh port */
3470 ssh->savedport = port;
3473 ssh->fn = &fn_table; /* make 'ssh' usable as a Plug */
3476 * Try connection-sharing, in case that means we don't open a
3477 * socket after all. ssh_connection_sharing_init will connect to a
3478 * previously established upstream if it can, and failing that,
3479 * establish a listening socket for _us_ to be the upstream. In
3480 * the latter case it will return NULL just as if it had done
3481 * nothing, because here we only need to care if we're a
3482 * downstream and need to do our connection setup differently.
3484 ssh->connshare = NULL;
3485 ssh->attempting_connshare = TRUE; /* affects socket logging behaviour */
3486 ssh->s = ssh_connection_sharing_init(ssh->savedhost, ssh->savedport,
3487 ssh->conf, ssh, &ssh->connshare);
3488 ssh->attempting_connshare = FALSE;
3489 if (ssh->s != NULL) {
3491 * We are a downstream.
3493 ssh->bare_connection = TRUE;
3494 ssh->do_ssh_init = do_ssh_connection_init;
3495 ssh->fullhostname = NULL;
3496 *realhost = dupstr(host); /* best we can do */
3499 * We're not a downstream, so open a normal socket.
3501 ssh->do_ssh_init = do_ssh_init;
3506 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
3507 logeventf(ssh, "Looking up host \"%s\"%s", host,
3508 (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
3509 (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
3510 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily);
3511 if ((err = sk_addr_error(addr)) != NULL) {
3515 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3517 ssh->s = new_connection(addr, *realhost, port,
3518 0, 1, nodelay, keepalive,
3519 (Plug) ssh, ssh->conf);
3520 if ((err = sk_socket_error(ssh->s)) != NULL) {
3522 notify_remote_exit(ssh->frontend);
3528 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3529 * send the version string too.
3531 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3534 if (sshprot == 3 && !ssh->bare_connection) {
3536 ssh_send_verstring(ssh, "SSH-", NULL);
3540 * loghost, if configured, overrides realhost.
3544 *realhost = dupstr(loghost);
3551 * Throttle or unthrottle the SSH connection.
3553 static void ssh_throttle_conn(Ssh ssh, int adjust)
3555 int old_count = ssh->conn_throttle_count;
3556 ssh->conn_throttle_count += adjust;
3557 assert(ssh->conn_throttle_count >= 0);
3558 if (ssh->conn_throttle_count && !old_count) {
3559 ssh_set_frozen(ssh, 1);
3560 } else if (!ssh->conn_throttle_count && old_count) {
3561 ssh_set_frozen(ssh, 0);
3566 * Throttle or unthrottle _all_ local data streams (for when sends
3567 * on the SSH connection itself back up).
3569 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3572 struct ssh_channel *c;
3574 if (enable == ssh->throttled_all)
3576 ssh->throttled_all = enable;
3577 ssh->overall_bufsize = bufsize;
3580 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3582 case CHAN_MAINSESSION:
3584 * This is treated separately, outside the switch.
3588 x11_override_throttle(c->u.x11.xconn, enable);
3591 /* Agent channels require no buffer management. */
3594 pfd_override_throttle(c->u.pfd.pf, enable);
3600 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3602 Ssh ssh = (Ssh) sshv;
3604 ssh->agent_response = reply;
3605 ssh->agent_response_len = replylen;
3607 if (ssh->version == 1)
3608 do_ssh1_login(ssh, NULL, -1, NULL);
3610 do_ssh2_authconn(ssh, NULL, -1, NULL);
3613 static void ssh_dialog_callback(void *sshv, int ret)
3615 Ssh ssh = (Ssh) sshv;
3617 ssh->user_response = ret;
3619 if (ssh->version == 1)
3620 do_ssh1_login(ssh, NULL, -1, NULL);
3622 do_ssh2_transport(ssh, NULL, -1, NULL);
3625 * This may have unfrozen the SSH connection, so do a
3628 ssh_process_queued_incoming_data(ssh);
3631 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3633 struct ssh_channel *c = (struct ssh_channel *)cv;
3635 void *sentreply = reply;
3637 c->u.a.outstanding_requests--;
3639 /* Fake SSH_AGENT_FAILURE. */
3640 sentreply = "\0\0\0\1\5";
3643 if (ssh->version == 2) {
3644 ssh2_add_channel_data(c, sentreply, replylen);
3647 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3648 PKT_INT, c->remoteid,
3650 PKT_DATA, sentreply, replylen,
3656 * If we've already seen an incoming EOF but haven't sent an
3657 * outgoing one, this may be the moment to send it.
3659 if (c->u.a.outstanding_requests == 0 && (c->closes & CLOSES_RCVD_EOF))
3660 sshfwd_write_eof(c);
3664 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3665 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3666 * => log `wire_reason'.
3668 static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
3669 int code, int clean_exit)
3673 client_reason = wire_reason;
3675 error = dupprintf("Disconnected: %s", client_reason);
3677 error = dupstr("Disconnected");
3679 if (ssh->version == 1) {
3680 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3682 } else if (ssh->version == 2) {
3683 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3684 ssh2_pkt_adduint32(pktout, code);
3685 ssh2_pkt_addstring(pktout, wire_reason);
3686 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3687 ssh2_pkt_send_noqueue(ssh, pktout);
3690 ssh->close_expected = TRUE;
3691 ssh->clean_exit = clean_exit;
3692 ssh_closing((Plug)ssh, error, 0, 0);
3696 int verify_ssh_manual_host_key(Ssh ssh, const char *fingerprint,
3697 const struct ssh_signkey *ssh2keytype,
3700 if (!conf_get_str_nthstrkey(ssh->conf, CONF_ssh_manual_hostkeys, 0)) {
3701 return -1; /* no manual keys configured */
3706 * The fingerprint string we've been given will have things
3707 * like 'ssh-rsa 2048' at the front of it. Strip those off and
3708 * narrow down to just the colon-separated hex block at the
3709 * end of the string.
3711 const char *p = strrchr(fingerprint, ' ');
3712 fingerprint = p ? p+1 : fingerprint;
3713 /* Quick sanity checks, including making sure it's in lowercase */
3714 assert(strlen(fingerprint) == 16*3 - 1);
3715 assert(fingerprint[2] == ':');
3716 assert(fingerprint[strspn(fingerprint, "0123456789abcdef:")] == 0);
3718 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3720 return 1; /* success */
3725 * Construct the base64-encoded public key blob and see if
3728 unsigned char *binblob;
3730 int binlen, atoms, i;
3731 binblob = ssh2keytype->public_blob(ssh2keydata, &binlen);
3732 atoms = (binlen + 2) / 3;
3733 base64blob = snewn(atoms * 4 + 1, char);
3734 for (i = 0; i < atoms; i++)
3735 base64_encode_atom(binblob + 3*i, binlen - 3*i, base64blob + 4*i);
3736 base64blob[atoms * 4] = '\0';
3738 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3741 return 1; /* success */
3750 * Handle the key exchange and user authentication phases.
3752 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
3753 struct Packet *pktin)
3756 unsigned char cookie[8], *ptr;
3757 struct MD5Context md5c;
3758 struct do_ssh1_login_state {
3761 unsigned char *rsabuf, *keystr1, *keystr2;
3762 unsigned long supported_ciphers_mask, supported_auths_mask;
3763 int tried_publickey, tried_agent;
3764 int tis_auth_refused, ccard_auth_refused;
3765 unsigned char session_id[16];
3767 void *publickey_blob;
3768 int publickey_bloblen;
3769 char *publickey_comment;
3770 int publickey_encrypted;
3771 prompts_t *cur_prompt;
3774 unsigned char request[5], *response, *p;
3784 struct RSAKey servkey, hostkey;
3786 crState(do_ssh1_login_state);
3793 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
3794 bombout(("Public key packet not received"));
3798 logevent("Received public keys");
3800 ptr = ssh_pkt_getdata(pktin, 8);
3802 bombout(("SSH-1 public key packet stopped before random cookie"));
3805 memcpy(cookie, ptr, 8);
3807 if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) ||
3808 !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) {
3809 bombout(("Failed to read SSH-1 public keys from public key packet"));
3814 * Log the host key fingerprint.
3818 logevent("Host key fingerprint is:");
3819 strcpy(logmsg, " ");
3820 s->hostkey.comment = NULL;
3821 rsa_fingerprint(logmsg + strlen(logmsg),
3822 sizeof(logmsg) - strlen(logmsg), &s->hostkey);
3826 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3827 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3828 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
3829 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
3830 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
3832 ssh->v1_local_protoflags =
3833 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3834 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
3837 MD5Update(&md5c, s->keystr2, s->hostkey.bytes);
3838 MD5Update(&md5c, s->keystr1, s->servkey.bytes);
3839 MD5Update(&md5c, cookie, 8);
3840 MD5Final(s->session_id, &md5c);
3842 for (i = 0; i < 32; i++)
3843 ssh->session_key[i] = random_byte();
3846 * Verify that the `bits' and `bytes' parameters match.
3848 if (s->hostkey.bits > s->hostkey.bytes * 8 ||
3849 s->servkey.bits > s->servkey.bytes * 8) {
3850 bombout(("SSH-1 public keys were badly formatted"));
3854 s->len = (s->hostkey.bytes > s->servkey.bytes ?
3855 s->hostkey.bytes : s->servkey.bytes);
3857 s->rsabuf = snewn(s->len, unsigned char);
3860 * Verify the host key.
3864 * First format the key into a string.
3866 int len = rsastr_len(&s->hostkey);
3867 char fingerprint[100];
3868 char *keystr = snewn(len, char);
3869 rsastr_fmt(keystr, &s->hostkey);
3870 rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey);
3872 /* First check against manually configured host keys. */
3873 s->dlgret = verify_ssh_manual_host_key(ssh, fingerprint, NULL, NULL);
3874 if (s->dlgret == 0) { /* did not match */
3875 bombout(("Host key did not appear in manually configured list"));
3877 } else if (s->dlgret < 0) { /* none configured; use standard handling */
3878 ssh_set_frozen(ssh, 1);
3879 s->dlgret = verify_ssh_host_key(ssh->frontend,
3880 ssh->savedhost, ssh->savedport,
3881 "rsa", keystr, fingerprint,
3882 ssh_dialog_callback, ssh);
3884 if (s->dlgret < 0) {
3888 bombout(("Unexpected data from server while waiting"
3889 " for user host key response"));
3892 } while (pktin || inlen > 0);
3893 s->dlgret = ssh->user_response;
3895 ssh_set_frozen(ssh, 0);
3897 if (s->dlgret == 0) {
3898 ssh_disconnect(ssh, "User aborted at host key verification",
3905 for (i = 0; i < 32; i++) {
3906 s->rsabuf[i] = ssh->session_key[i];
3908 s->rsabuf[i] ^= s->session_id[i];
3911 if (s->hostkey.bytes > s->servkey.bytes) {
3912 ret = rsaencrypt(s->rsabuf, 32, &s->servkey);
3914 ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey);
3916 ret = rsaencrypt(s->rsabuf, 32, &s->hostkey);
3918 ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey);
3921 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3925 logevent("Encrypted session key");
3928 int cipher_chosen = 0, warn = 0;
3929 char *cipher_string = NULL;
3931 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
3932 int next_cipher = conf_get_int_int(ssh->conf,
3933 CONF_ssh_cipherlist, i);
3934 if (next_cipher == CIPHER_WARN) {
3935 /* If/when we choose a cipher, warn about it */
3937 } else if (next_cipher == CIPHER_AES) {
3938 /* XXX Probably don't need to mention this. */
3939 logevent("AES not supported in SSH-1, skipping");
3941 switch (next_cipher) {
3942 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
3943 cipher_string = "3DES"; break;
3944 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
3945 cipher_string = "Blowfish"; break;
3946 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
3947 cipher_string = "single-DES"; break;
3949 if (s->supported_ciphers_mask & (1 << s->cipher_type))
3953 if (!cipher_chosen) {
3954 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
3955 bombout(("Server violates SSH-1 protocol by not "
3956 "supporting 3DES encryption"));
3958 /* shouldn't happen */
3959 bombout(("No supported ciphers found"));
3963 /* Warn about chosen cipher if necessary. */
3965 ssh_set_frozen(ssh, 1);
3966 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3967 ssh_dialog_callback, ssh);
3968 if (s->dlgret < 0) {
3972 bombout(("Unexpected data from server while waiting"
3973 " for user response"));
3976 } while (pktin || inlen > 0);
3977 s->dlgret = ssh->user_response;
3979 ssh_set_frozen(ssh, 0);
3980 if (s->dlgret == 0) {
3981 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3988 switch (s->cipher_type) {
3989 case SSH_CIPHER_3DES:
3990 logevent("Using 3DES encryption");
3992 case SSH_CIPHER_DES:
3993 logevent("Using single-DES encryption");
3995 case SSH_CIPHER_BLOWFISH:
3996 logevent("Using Blowfish encryption");
4000 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
4001 PKT_CHAR, s->cipher_type,
4002 PKT_DATA, cookie, 8,
4003 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
4004 PKT_DATA, s->rsabuf, s->len,
4005 PKT_INT, ssh->v1_local_protoflags, PKT_END);
4007 logevent("Trying to enable encryption...");
4011 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
4012 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
4014 ssh->v1_cipher_ctx = ssh->cipher->make_context();
4015 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
4016 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
4018 ssh->crcda_ctx = crcda_make_context();
4019 logevent("Installing CRC compensation attack detector");
4021 if (s->servkey.modulus) {
4022 sfree(s->servkey.modulus);
4023 s->servkey.modulus = NULL;
4025 if (s->servkey.exponent) {
4026 sfree(s->servkey.exponent);
4027 s->servkey.exponent = NULL;
4029 if (s->hostkey.modulus) {
4030 sfree(s->hostkey.modulus);
4031 s->hostkey.modulus = NULL;
4033 if (s->hostkey.exponent) {
4034 sfree(s->hostkey.exponent);
4035 s->hostkey.exponent = NULL;
4039 if (pktin->type != SSH1_SMSG_SUCCESS) {
4040 bombout(("Encryption not successfully enabled"));
4044 logevent("Successfully started encryption");
4046 fflush(stdout); /* FIXME eh? */
4048 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
4049 int ret; /* need not be kept over crReturn */
4050 s->cur_prompt = new_prompts(ssh->frontend);
4051 s->cur_prompt->to_server = TRUE;
4052 s->cur_prompt->name = dupstr("SSH login name");
4053 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
4054 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4057 crWaitUntil(!pktin);
4058 ret = get_userpass_input(s->cur_prompt, in, inlen);
4063 * Failed to get a username. Terminate.
4065 free_prompts(s->cur_prompt);
4066 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
4069 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
4070 free_prompts(s->cur_prompt);
4073 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
4075 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
4077 if (flags & FLAG_INTERACTIVE &&
4078 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
4079 c_write_str(ssh, userlog);
4080 c_write_str(ssh, "\r\n");
4088 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
4089 /* We must not attempt PK auth. Pretend we've already tried it. */
4090 s->tried_publickey = s->tried_agent = 1;
4092 s->tried_publickey = s->tried_agent = 0;
4094 s->tis_auth_refused = s->ccard_auth_refused = 0;
4096 * Load the public half of any configured keyfile for later use.
4098 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4099 if (!filename_is_null(s->keyfile)) {
4101 logeventf(ssh, "Reading private key file \"%.150s\"",
4102 filename_to_str(s->keyfile));
4103 keytype = key_type(s->keyfile);
4104 if (keytype == SSH_KEYTYPE_SSH1) {
4106 if (rsakey_pubblob(s->keyfile,
4107 &s->publickey_blob, &s->publickey_bloblen,
4108 &s->publickey_comment, &error)) {
4109 s->publickey_encrypted = rsakey_encrypted(s->keyfile,
4113 logeventf(ssh, "Unable to load private key (%s)", error);
4114 msgbuf = dupprintf("Unable to load private key file "
4115 "\"%.150s\" (%s)\r\n",
4116 filename_to_str(s->keyfile),
4118 c_write_str(ssh, msgbuf);
4120 s->publickey_blob = NULL;
4124 logeventf(ssh, "Unable to use this key file (%s)",
4125 key_type_to_str(keytype));
4126 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4128 filename_to_str(s->keyfile),
4129 key_type_to_str(keytype));
4130 c_write_str(ssh, msgbuf);
4132 s->publickey_blob = NULL;
4135 s->publickey_blob = NULL;
4137 while (pktin->type == SSH1_SMSG_FAILURE) {
4138 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
4140 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
4142 * Attempt RSA authentication using Pageant.
4148 logevent("Pageant is running. Requesting keys.");
4150 /* Request the keys held by the agent. */
4151 PUT_32BIT(s->request, 1);
4152 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
4153 if (!agent_query(s->request, 5, &r, &s->responselen,
4154 ssh_agent_callback, ssh)) {
4158 bombout(("Unexpected data from server while waiting"
4159 " for agent response"));
4162 } while (pktin || inlen > 0);
4163 r = ssh->agent_response;
4164 s->responselen = ssh->agent_response_len;
4166 s->response = (unsigned char *) r;
4167 if (s->response && s->responselen >= 5 &&
4168 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
4169 s->p = s->response + 5;
4170 s->nkeys = toint(GET_32BIT(s->p));
4172 logeventf(ssh, "Pageant reported negative key count %d",
4177 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
4178 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4179 unsigned char *pkblob = s->p;
4183 do { /* do while (0) to make breaking easy */
4184 n = ssh1_read_bignum
4185 (s->p, toint(s->responselen-(s->p-s->response)),
4190 n = ssh1_read_bignum
4191 (s->p, toint(s->responselen-(s->p-s->response)),
4196 if (s->responselen - (s->p-s->response) < 4)
4198 s->commentlen = toint(GET_32BIT(s->p));
4200 if (s->commentlen < 0 ||
4201 toint(s->responselen - (s->p-s->response)) <
4204 s->commentp = (char *)s->p;
4205 s->p += s->commentlen;
4209 logevent("Pageant key list packet was truncated");
4213 if (s->publickey_blob) {
4214 if (!memcmp(pkblob, s->publickey_blob,
4215 s->publickey_bloblen)) {
4216 logeventf(ssh, "Pageant key #%d matches "
4217 "configured key file", s->keyi);
4218 s->tried_publickey = 1;
4220 /* Skip non-configured key */
4223 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
4224 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4225 PKT_BIGNUM, s->key.modulus, PKT_END);
4227 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4228 logevent("Key refused");
4231 logevent("Received RSA challenge");
4232 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4233 bombout(("Server's RSA challenge was badly formatted"));
4238 char *agentreq, *q, *ret;
4241 len = 1 + 4; /* message type, bit count */
4242 len += ssh1_bignum_length(s->key.exponent);
4243 len += ssh1_bignum_length(s->key.modulus);
4244 len += ssh1_bignum_length(s->challenge);
4245 len += 16; /* session id */
4246 len += 4; /* response format */
4247 agentreq = snewn(4 + len, char);
4248 PUT_32BIT(agentreq, len);
4250 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
4251 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
4253 q += ssh1_write_bignum(q, s->key.exponent);
4254 q += ssh1_write_bignum(q, s->key.modulus);
4255 q += ssh1_write_bignum(q, s->challenge);
4256 memcpy(q, s->session_id, 16);
4258 PUT_32BIT(q, 1); /* response format */
4259 if (!agent_query(agentreq, len + 4, &vret, &retlen,
4260 ssh_agent_callback, ssh)) {
4265 bombout(("Unexpected data from server"
4266 " while waiting for agent"
4270 } while (pktin || inlen > 0);
4271 vret = ssh->agent_response;
4272 retlen = ssh->agent_response_len;
4277 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
4278 logevent("Sending Pageant's response");
4279 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4280 PKT_DATA, ret + 5, 16,
4284 if (pktin->type == SSH1_SMSG_SUCCESS) {
4286 ("Pageant's response accepted");
4287 if (flags & FLAG_VERBOSE) {
4288 c_write_str(ssh, "Authenticated using"
4290 c_write(ssh, s->commentp,
4292 c_write_str(ssh, "\" from agent\r\n");
4297 ("Pageant's response not accepted");
4300 ("Pageant failed to answer challenge");
4304 logevent("No reply received from Pageant");
4307 freebn(s->key.exponent);
4308 freebn(s->key.modulus);
4309 freebn(s->challenge);
4314 if (s->publickey_blob && !s->tried_publickey)
4315 logevent("Configured key file not in Pageant");
4317 logevent("Failed to get reply from Pageant");
4322 if (s->publickey_blob && !s->tried_publickey) {
4324 * Try public key authentication with the specified
4327 int got_passphrase; /* need not be kept over crReturn */
4328 if (flags & FLAG_VERBOSE)
4329 c_write_str(ssh, "Trying public key authentication.\r\n");
4330 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4331 logeventf(ssh, "Trying public key \"%s\"",
4332 filename_to_str(s->keyfile));
4333 s->tried_publickey = 1;
4334 got_passphrase = FALSE;
4335 while (!got_passphrase) {
4337 * Get a passphrase, if necessary.
4339 char *passphrase = NULL; /* only written after crReturn */
4341 if (!s->publickey_encrypted) {
4342 if (flags & FLAG_VERBOSE)
4343 c_write_str(ssh, "No passphrase required.\r\n");
4346 int ret; /* need not be kept over crReturn */
4347 s->cur_prompt = new_prompts(ssh->frontend);
4348 s->cur_prompt->to_server = FALSE;
4349 s->cur_prompt->name = dupstr("SSH key passphrase");
4350 add_prompt(s->cur_prompt,
4351 dupprintf("Passphrase for key \"%.100s\": ",
4352 s->publickey_comment), FALSE);
4353 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4356 crWaitUntil(!pktin);
4357 ret = get_userpass_input(s->cur_prompt, in, inlen);
4361 /* Failed to get a passphrase. Terminate. */
4362 free_prompts(s->cur_prompt);
4363 ssh_disconnect(ssh, NULL, "Unable to authenticate",
4367 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
4368 free_prompts(s->cur_prompt);
4371 * Try decrypting key with passphrase.
4373 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4374 ret = loadrsakey(s->keyfile, &s->key, passphrase,
4377 smemclr(passphrase, strlen(passphrase));
4381 /* Correct passphrase. */
4382 got_passphrase = TRUE;
4383 } else if (ret == 0) {
4384 c_write_str(ssh, "Couldn't load private key from ");
4385 c_write_str(ssh, filename_to_str(s->keyfile));
4386 c_write_str(ssh, " (");
4387 c_write_str(ssh, error);
4388 c_write_str(ssh, ").\r\n");
4389 got_passphrase = FALSE;
4390 break; /* go and try something else */
4391 } else if (ret == -1) {
4392 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
4393 got_passphrase = FALSE;
4396 assert(0 && "unexpected return from loadrsakey()");
4397 got_passphrase = FALSE; /* placate optimisers */
4401 if (got_passphrase) {
4404 * Send a public key attempt.
4406 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4407 PKT_BIGNUM, s->key.modulus, PKT_END);
4410 if (pktin->type == SSH1_SMSG_FAILURE) {
4411 c_write_str(ssh, "Server refused our public key.\r\n");
4412 continue; /* go and try something else */
4414 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4415 bombout(("Bizarre response to offer of public key"));
4421 unsigned char buffer[32];
4422 Bignum challenge, response;
4424 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4425 bombout(("Server's RSA challenge was badly formatted"));
4428 response = rsadecrypt(challenge, &s->key);
4429 freebn(s->key.private_exponent);/* burn the evidence */
4431 for (i = 0; i < 32; i++) {
4432 buffer[i] = bignum_byte(response, 31 - i);
4436 MD5Update(&md5c, buffer, 32);
4437 MD5Update(&md5c, s->session_id, 16);
4438 MD5Final(buffer, &md5c);
4440 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4441 PKT_DATA, buffer, 16, PKT_END);
4448 if (pktin->type == SSH1_SMSG_FAILURE) {
4449 if (flags & FLAG_VERBOSE)
4450 c_write_str(ssh, "Failed to authenticate with"
4451 " our public key.\r\n");
4452 continue; /* go and try something else */
4453 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4454 bombout(("Bizarre response to RSA authentication response"));
4458 break; /* we're through! */
4464 * Otherwise, try various forms of password-like authentication.
4466 s->cur_prompt = new_prompts(ssh->frontend);
4468 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4469 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
4470 !s->tis_auth_refused) {
4471 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
4472 logevent("Requested TIS authentication");
4473 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
4475 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
4476 logevent("TIS authentication declined");
4477 if (flags & FLAG_INTERACTIVE)
4478 c_write_str(ssh, "TIS authentication refused.\r\n");
4479 s->tis_auth_refused = 1;
4484 char *instr_suf, *prompt;
4486 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4488 bombout(("TIS challenge packet was badly formed"));
4491 logevent("Received TIS challenge");
4492 s->cur_prompt->to_server = TRUE;
4493 s->cur_prompt->name = dupstr("SSH TIS authentication");
4494 /* Prompt heuristic comes from OpenSSH */
4495 if (memchr(challenge, '\n', challengelen)) {
4496 instr_suf = dupstr("");
4497 prompt = dupprintf("%.*s", challengelen, challenge);
4499 instr_suf = dupprintf("%.*s", challengelen, challenge);
4500 prompt = dupstr("Response: ");
4502 s->cur_prompt->instruction =
4503 dupprintf("Using TIS authentication.%s%s",
4504 (*instr_suf) ? "\n" : "",
4506 s->cur_prompt->instr_reqd = TRUE;
4507 add_prompt(s->cur_prompt, prompt, FALSE);
4511 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4512 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
4513 !s->ccard_auth_refused) {
4514 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
4515 logevent("Requested CryptoCard authentication");
4516 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
4518 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
4519 logevent("CryptoCard authentication declined");
4520 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4521 s->ccard_auth_refused = 1;
4526 char *instr_suf, *prompt;
4528 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4530 bombout(("CryptoCard challenge packet was badly formed"));
4533 logevent("Received CryptoCard challenge");
4534 s->cur_prompt->to_server = TRUE;
4535 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4536 s->cur_prompt->name_reqd = FALSE;
4537 /* Prompt heuristic comes from OpenSSH */
4538 if (memchr(challenge, '\n', challengelen)) {
4539 instr_suf = dupstr("");
4540 prompt = dupprintf("%.*s", challengelen, challenge);
4542 instr_suf = dupprintf("%.*s", challengelen, challenge);
4543 prompt = dupstr("Response: ");
4545 s->cur_prompt->instruction =
4546 dupprintf("Using CryptoCard authentication.%s%s",
4547 (*instr_suf) ? "\n" : "",
4549 s->cur_prompt->instr_reqd = TRUE;
4550 add_prompt(s->cur_prompt, prompt, FALSE);
4554 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4555 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4556 bombout(("No supported authentication methods available"));
4559 s->cur_prompt->to_server = TRUE;
4560 s->cur_prompt->name = dupstr("SSH password");
4561 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4562 ssh->username, ssh->savedhost),
4567 * Show password prompt, having first obtained it via a TIS
4568 * or CryptoCard exchange if we're doing TIS or CryptoCard
4572 int ret; /* need not be kept over crReturn */
4573 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4576 crWaitUntil(!pktin);
4577 ret = get_userpass_input(s->cur_prompt, in, inlen);
4582 * Failed to get a password (for example
4583 * because one was supplied on the command line
4584 * which has already failed to work). Terminate.
4586 free_prompts(s->cur_prompt);
4587 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4592 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4594 * Defence against traffic analysis: we send a
4595 * whole bunch of packets containing strings of
4596 * different lengths. One of these strings is the
4597 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4598 * The others are all random data in
4599 * SSH1_MSG_IGNORE packets. This way a passive
4600 * listener can't tell which is the password, and
4601 * hence can't deduce the password length.
4603 * Anybody with a password length greater than 16
4604 * bytes is going to have enough entropy in their
4605 * password that a listener won't find it _that_
4606 * much help to know how long it is. So what we'll
4609 * - if password length < 16, we send 15 packets
4610 * containing string lengths 1 through 15
4612 * - otherwise, we let N be the nearest multiple
4613 * of 8 below the password length, and send 8
4614 * packets containing string lengths N through
4615 * N+7. This won't obscure the order of
4616 * magnitude of the password length, but it will
4617 * introduce a bit of extra uncertainty.
4619 * A few servers can't deal with SSH1_MSG_IGNORE, at
4620 * least in this context. For these servers, we need
4621 * an alternative defence. We make use of the fact
4622 * that the password is interpreted as a C string:
4623 * so we can append a NUL, then some random data.
4625 * A few servers can deal with neither SSH1_MSG_IGNORE
4626 * here _nor_ a padded password string.
4627 * For these servers we are left with no defences
4628 * against password length sniffing.
4630 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4631 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4633 * The server can deal with SSH1_MSG_IGNORE, so
4634 * we can use the primary defence.
4636 int bottom, top, pwlen, i;
4639 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4641 bottom = 0; /* zero length passwords are OK! :-) */
4644 bottom = pwlen & ~7;
4648 assert(pwlen >= bottom && pwlen <= top);
4650 randomstr = snewn(top + 1, char);
4652 for (i = bottom; i <= top; i++) {
4654 defer_packet(ssh, s->pwpkt_type,
4655 PKT_STR,s->cur_prompt->prompts[0]->result,
4658 for (j = 0; j < i; j++) {
4660 randomstr[j] = random_byte();
4661 } while (randomstr[j] == '\0');
4663 randomstr[i] = '\0';
4664 defer_packet(ssh, SSH1_MSG_IGNORE,
4665 PKT_STR, randomstr, PKT_END);
4668 logevent("Sending password with camouflage packets");
4669 ssh_pkt_defersend(ssh);
4672 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4674 * The server can't deal with SSH1_MSG_IGNORE
4675 * but can deal with padded passwords, so we
4676 * can use the secondary defence.
4682 len = strlen(s->cur_prompt->prompts[0]->result);
4683 if (len < sizeof(string)) {
4685 strcpy(string, s->cur_prompt->prompts[0]->result);
4686 len++; /* cover the zero byte */
4687 while (len < sizeof(string)) {
4688 string[len++] = (char) random_byte();
4691 ss = s->cur_prompt->prompts[0]->result;
4693 logevent("Sending length-padded password");
4694 send_packet(ssh, s->pwpkt_type,
4695 PKT_INT, len, PKT_DATA, ss, len,
4699 * The server is believed unable to cope with
4700 * any of our password camouflage methods.
4703 len = strlen(s->cur_prompt->prompts[0]->result);
4704 logevent("Sending unpadded password");
4705 send_packet(ssh, s->pwpkt_type,
4707 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4711 send_packet(ssh, s->pwpkt_type,
4712 PKT_STR, s->cur_prompt->prompts[0]->result,
4715 logevent("Sent password");
4716 free_prompts(s->cur_prompt);
4718 if (pktin->type == SSH1_SMSG_FAILURE) {
4719 if (flags & FLAG_VERBOSE)
4720 c_write_str(ssh, "Access denied\r\n");
4721 logevent("Authentication refused");
4722 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4723 bombout(("Strange packet received, type %d", pktin->type));
4729 if (s->publickey_blob) {
4730 sfree(s->publickey_blob);
4731 sfree(s->publickey_comment);
4734 logevent("Authentication successful");
4739 static void ssh_channel_try_eof(struct ssh_channel *c)
4742 assert(c->pending_eof); /* precondition for calling us */
4744 return; /* can't close: not even opened yet */
4745 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4746 return; /* can't send EOF: pending outgoing data */
4748 c->pending_eof = FALSE; /* we're about to send it */
4749 if (ssh->version == 1) {
4750 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4752 c->closes |= CLOSES_SENT_EOF;
4754 struct Packet *pktout;
4755 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4756 ssh2_pkt_adduint32(pktout, c->remoteid);
4757 ssh2_pkt_send(ssh, pktout);
4758 c->closes |= CLOSES_SENT_EOF;
4759 ssh2_channel_check_close(c);
4763 Conf *sshfwd_get_conf(struct ssh_channel *c)
4769 void sshfwd_write_eof(struct ssh_channel *c)
4773 if (ssh->state == SSH_STATE_CLOSED)
4776 if (c->closes & CLOSES_SENT_EOF)
4779 c->pending_eof = TRUE;
4780 ssh_channel_try_eof(c);
4783 void sshfwd_unclean_close(struct ssh_channel *c, const char *err)
4787 if (ssh->state == SSH_STATE_CLOSED)
4792 x11_close(c->u.x11.xconn);
4793 logeventf(ssh, "Forwarded X11 connection terminated due to local "
4797 case CHAN_SOCKDATA_DORMANT:
4798 pfd_close(c->u.pfd.pf);
4799 logeventf(ssh, "Forwarded port closed due to local error: %s", err);
4802 c->type = CHAN_ZOMBIE;
4803 c->pending_eof = FALSE; /* this will confuse a zombie channel */
4805 ssh2_channel_check_close(c);
4808 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
4812 if (ssh->state == SSH_STATE_CLOSED)
4815 if (ssh->version == 1) {
4816 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
4817 PKT_INT, c->remoteid,
4818 PKT_INT, len, PKT_DATA, buf, len,
4821 * In SSH-1 we can return 0 here - implying that forwarded
4822 * connections are never individually throttled - because
4823 * the only circumstance that can cause throttling will be
4824 * the whole SSH connection backing up, in which case
4825 * _everything_ will be throttled as a whole.
4829 ssh2_add_channel_data(c, buf, len);
4830 return ssh2_try_send(c);
4834 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4839 if (ssh->state == SSH_STATE_CLOSED)
4842 if (ssh->version == 1) {
4843 buflimit = SSH1_BUFFER_LIMIT;
4845 buflimit = c->v.v2.locmaxwin;
4846 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
4848 if (c->throttling_conn && bufsize <= buflimit) {
4849 c->throttling_conn = 0;
4850 ssh_throttle_conn(ssh, -1);
4854 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
4856 struct queued_handler *qh = ssh->qhead;
4860 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
4863 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
4864 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
4867 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
4868 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
4872 ssh->qhead = qh->next;
4874 if (ssh->qhead->msg1 > 0) {
4875 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4876 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
4878 if (ssh->qhead->msg2 > 0) {
4879 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4880 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
4883 ssh->qhead = ssh->qtail = NULL;
4886 qh->handler(ssh, pktin, qh->ctx);
4891 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
4892 chandler_fn_t handler, void *ctx)
4894 struct queued_handler *qh;
4896 qh = snew(struct queued_handler);
4899 qh->handler = handler;
4903 if (ssh->qtail == NULL) {
4907 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4908 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
4911 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4912 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
4915 ssh->qtail->next = qh;
4920 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
4922 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
4924 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
4925 SSH2_MSG_REQUEST_SUCCESS)) {
4926 logeventf(ssh, "Remote port forwarding from %s enabled",
4929 logeventf(ssh, "Remote port forwarding from %s refused",
4932 rpf = del234(ssh->rportfwds, pf);
4934 pf->pfrec->remote = NULL;
4939 int ssh_alloc_sharing_rportfwd(Ssh ssh, const char *shost, int sport,
4942 struct ssh_rportfwd *pf = snew(struct ssh_rportfwd);
4945 pf->share_ctx = share_ctx;
4946 pf->shost = dupstr(shost);
4948 pf->sportdesc = NULL;
4949 if (!ssh->rportfwds) {
4950 assert(ssh->version == 2);
4951 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4953 if (add234(ssh->rportfwds, pf) != pf) {
4961 static void ssh_sharing_global_request_response(Ssh ssh, struct Packet *pktin,
4964 share_got_pkt_from_server(ctx, pktin->type,
4965 pktin->body, pktin->length);
4968 void ssh_sharing_queue_global_request(Ssh ssh, void *share_ctx)
4970 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, SSH2_MSG_REQUEST_FAILURE,
4971 ssh_sharing_global_request_response, share_ctx);
4974 static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
4976 struct ssh_portfwd *epf;
4980 if (!ssh->portfwds) {
4981 ssh->portfwds = newtree234(ssh_portcmp);
4984 * Go through the existing port forwardings and tag them
4985 * with status==DESTROY. Any that we want to keep will be
4986 * re-enabled (status==KEEP) as we go through the
4987 * configuration and find out which bits are the same as
4990 struct ssh_portfwd *epf;
4992 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4993 epf->status = DESTROY;
4996 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
4998 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
4999 char *kp, *kp2, *vp, *vp2;
5000 char address_family, type;
5001 int sport,dport,sserv,dserv;
5002 char *sports, *dports, *saddr, *host;
5006 address_family = 'A';
5008 if (*kp == 'A' || *kp == '4' || *kp == '6')
5009 address_family = *kp++;
5010 if (*kp == 'L' || *kp == 'R')
5013 if ((kp2 = host_strchr(kp, ':')) != NULL) {
5015 * There's a colon in the middle of the source port
5016 * string, which means that the part before it is
5017 * actually a source address.
5019 char *saddr_tmp = dupprintf("%.*s", (int)(kp2 - kp), kp);
5020 saddr = host_strduptrim(saddr_tmp);
5027 sport = atoi(sports);
5031 sport = net_service_lookup(sports);
5033 logeventf(ssh, "Service lookup failed for source"
5034 " port \"%s\"", sports);
5038 if (type == 'L' && !strcmp(val, "D")) {
5039 /* dynamic forwarding */
5046 /* ordinary forwarding */
5048 vp2 = vp + host_strcspn(vp, ":");
5049 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
5053 dport = atoi(dports);
5057 dport = net_service_lookup(dports);
5059 logeventf(ssh, "Service lookup failed for destination"
5060 " port \"%s\"", dports);
5065 if (sport && dport) {
5066 /* Set up a description of the source port. */
5067 struct ssh_portfwd *pfrec, *epfrec;
5069 pfrec = snew(struct ssh_portfwd);
5071 pfrec->saddr = saddr;
5072 pfrec->sserv = sserv ? dupstr(sports) : NULL;
5073 pfrec->sport = sport;
5074 pfrec->daddr = host;
5075 pfrec->dserv = dserv ? dupstr(dports) : NULL;
5076 pfrec->dport = dport;
5077 pfrec->local = NULL;
5078 pfrec->remote = NULL;
5079 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
5080 address_family == '6' ? ADDRTYPE_IPV6 :
5083 epfrec = add234(ssh->portfwds, pfrec);
5084 if (epfrec != pfrec) {
5085 if (epfrec->status == DESTROY) {
5087 * We already have a port forwarding up and running
5088 * with precisely these parameters. Hence, no need
5089 * to do anything; simply re-tag the existing one
5092 epfrec->status = KEEP;
5095 * Anything else indicates that there was a duplicate
5096 * in our input, which we'll silently ignore.
5098 free_portfwd(pfrec);
5100 pfrec->status = CREATE;
5109 * Now go through and destroy any port forwardings which were
5112 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5113 if (epf->status == DESTROY) {
5116 message = dupprintf("%s port forwarding from %s%s%d",
5117 epf->type == 'L' ? "local" :
5118 epf->type == 'R' ? "remote" : "dynamic",
5119 epf->saddr ? epf->saddr : "",
5120 epf->saddr ? ":" : "",
5123 if (epf->type != 'D') {
5124 char *msg2 = dupprintf("%s to %s:%d", message,
5125 epf->daddr, epf->dport);
5130 logeventf(ssh, "Cancelling %s", message);
5133 /* epf->remote or epf->local may be NULL if setting up a
5134 * forwarding failed. */
5136 struct ssh_rportfwd *rpf = epf->remote;
5137 struct Packet *pktout;
5140 * Cancel the port forwarding at the server
5143 if (ssh->version == 1) {
5145 * We cannot cancel listening ports on the
5146 * server side in SSH-1! There's no message
5147 * to support it. Instead, we simply remove
5148 * the rportfwd record from the local end
5149 * so that any connections the server tries
5150 * to make on it are rejected.
5153 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5154 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
5155 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
5157 ssh2_pkt_addstring(pktout, epf->saddr);
5158 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5159 /* XXX: rport_acceptall may not represent
5160 * what was used to open the original connection,
5161 * since it's reconfigurable. */
5162 ssh2_pkt_addstring(pktout, "");
5164 ssh2_pkt_addstring(pktout, "localhost");
5166 ssh2_pkt_adduint32(pktout, epf->sport);
5167 ssh2_pkt_send(ssh, pktout);
5170 del234(ssh->rportfwds, rpf);
5172 } else if (epf->local) {
5173 pfl_terminate(epf->local);
5176 delpos234(ssh->portfwds, i);
5178 i--; /* so we don't skip one in the list */
5182 * And finally, set up any new port forwardings (status==CREATE).
5184 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5185 if (epf->status == CREATE) {
5186 char *sportdesc, *dportdesc;
5187 sportdesc = dupprintf("%s%s%s%s%d%s",
5188 epf->saddr ? epf->saddr : "",
5189 epf->saddr ? ":" : "",
5190 epf->sserv ? epf->sserv : "",
5191 epf->sserv ? "(" : "",
5193 epf->sserv ? ")" : "");
5194 if (epf->type == 'D') {
5197 dportdesc = dupprintf("%s:%s%s%d%s",
5199 epf->dserv ? epf->dserv : "",
5200 epf->dserv ? "(" : "",
5202 epf->dserv ? ")" : "");
5205 if (epf->type == 'L') {
5206 char *err = pfl_listen(epf->daddr, epf->dport,
5207 epf->saddr, epf->sport,
5208 ssh, conf, &epf->local,
5209 epf->addressfamily);
5211 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
5212 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5213 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5214 sportdesc, dportdesc,
5215 err ? " failed: " : "", err ? err : "");
5218 } else if (epf->type == 'D') {
5219 char *err = pfl_listen(NULL, -1, epf->saddr, epf->sport,
5220 ssh, conf, &epf->local,
5221 epf->addressfamily);
5223 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
5224 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5225 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5227 err ? " failed: " : "", err ? err : "");
5232 struct ssh_rportfwd *pf;
5235 * Ensure the remote port forwardings tree exists.
5237 if (!ssh->rportfwds) {
5238 if (ssh->version == 1)
5239 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
5241 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5244 pf = snew(struct ssh_rportfwd);
5245 pf->share_ctx = NULL;
5246 pf->dhost = dupstr(epf->daddr);
5247 pf->dport = epf->dport;
5249 pf->shost = dupstr(epf->saddr);
5250 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5251 pf->shost = dupstr("");
5253 pf->shost = dupstr("localhost");
5255 pf->sport = epf->sport;
5256 if (add234(ssh->rportfwds, pf) != pf) {
5257 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
5258 epf->daddr, epf->dport);
5261 logeventf(ssh, "Requesting remote port %s"
5262 " forward to %s", sportdesc, dportdesc);
5264 pf->sportdesc = sportdesc;
5269 if (ssh->version == 1) {
5270 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
5271 PKT_INT, epf->sport,
5272 PKT_STR, epf->daddr,
5273 PKT_INT, epf->dport,
5275 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
5277 ssh_rportfwd_succfail, pf);
5279 struct Packet *pktout;
5280 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5281 ssh2_pkt_addstring(pktout, "tcpip-forward");
5282 ssh2_pkt_addbool(pktout, 1);/* want reply */
5283 ssh2_pkt_addstring(pktout, pf->shost);
5284 ssh2_pkt_adduint32(pktout, pf->sport);
5285 ssh2_pkt_send(ssh, pktout);
5287 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
5288 SSH2_MSG_REQUEST_FAILURE,
5289 ssh_rportfwd_succfail, pf);
5298 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
5301 int stringlen, bufsize;
5303 ssh_pkt_getstring(pktin, &string, &stringlen);
5304 if (string == NULL) {
5305 bombout(("Incoming terminal data packet was badly formed"));
5309 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
5311 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
5312 ssh->v1_stdout_throttling = 1;
5313 ssh_throttle_conn(ssh, +1);
5317 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
5319 /* Remote side is trying to open a channel to talk to our
5320 * X-Server. Give them back a local channel number. */
5321 struct ssh_channel *c;
5322 int remoteid = ssh_pkt_getuint32(pktin);
5324 logevent("Received X11 connect request");
5325 /* Refuse if X11 forwarding is disabled. */
5326 if (!ssh->X11_fwd_enabled) {
5327 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5328 PKT_INT, remoteid, PKT_END);
5329 logevent("Rejected X11 connect request");
5331 c = snew(struct ssh_channel);
5334 c->u.x11.xconn = x11_init(ssh->x11authtree, c, NULL, -1);
5335 c->remoteid = remoteid;
5336 c->halfopen = FALSE;
5337 c->localid = alloc_channel_id(ssh);
5339 c->pending_eof = FALSE;
5340 c->throttling_conn = 0;
5341 c->type = CHAN_X11; /* identify channel type */
5342 add234(ssh->channels, c);
5343 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5344 PKT_INT, c->remoteid, PKT_INT,
5345 c->localid, PKT_END);
5346 logevent("Opened X11 forward channel");
5350 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
5352 /* Remote side is trying to open a channel to talk to our
5353 * agent. Give them back a local channel number. */
5354 struct ssh_channel *c;
5355 int remoteid = ssh_pkt_getuint32(pktin);
5357 /* Refuse if agent forwarding is disabled. */
5358 if (!ssh->agentfwd_enabled) {
5359 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5360 PKT_INT, remoteid, PKT_END);
5362 c = snew(struct ssh_channel);
5364 c->remoteid = remoteid;
5365 c->halfopen = FALSE;
5366 c->localid = alloc_channel_id(ssh);
5368 c->pending_eof = FALSE;
5369 c->throttling_conn = 0;
5370 c->type = CHAN_AGENT; /* identify channel type */
5371 c->u.a.lensofar = 0;
5372 c->u.a.message = NULL;
5373 c->u.a.outstanding_requests = 0;
5374 add234(ssh->channels, c);
5375 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5376 PKT_INT, c->remoteid, PKT_INT, c->localid,
5381 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
5383 /* Remote side is trying to open a channel to talk to a
5384 * forwarded port. Give them back a local channel number. */
5385 struct ssh_rportfwd pf, *pfp;
5391 remoteid = ssh_pkt_getuint32(pktin);
5392 ssh_pkt_getstring(pktin, &host, &hostsize);
5393 port = ssh_pkt_getuint32(pktin);
5395 pf.dhost = dupprintf("%.*s", hostsize, host);
5397 pfp = find234(ssh->rportfwds, &pf, NULL);
5400 logeventf(ssh, "Rejected remote port open request for %s:%d",
5402 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5403 PKT_INT, remoteid, PKT_END);
5405 struct ssh_channel *c = snew(struct ssh_channel);
5408 logeventf(ssh, "Received remote port open request for %s:%d",
5410 err = pfd_connect(&c->u.pfd.pf, pf.dhost, port,
5411 c, ssh->conf, pfp->pfrec->addressfamily);
5413 logeventf(ssh, "Port open failed: %s", err);
5416 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5417 PKT_INT, remoteid, PKT_END);
5419 c->remoteid = remoteid;
5420 c->halfopen = FALSE;
5421 c->localid = alloc_channel_id(ssh);
5423 c->pending_eof = FALSE;
5424 c->throttling_conn = 0;
5425 c->type = CHAN_SOCKDATA; /* identify channel type */
5426 add234(ssh->channels, c);
5427 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5428 PKT_INT, c->remoteid, PKT_INT,
5429 c->localid, PKT_END);
5430 logevent("Forwarded port opened successfully");
5437 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5439 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5440 unsigned int localid = ssh_pkt_getuint32(pktin);
5441 struct ssh_channel *c;
5443 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5444 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5445 c->remoteid = localid;
5446 c->halfopen = FALSE;
5447 c->type = CHAN_SOCKDATA;
5448 c->throttling_conn = 0;
5449 pfd_confirm(c->u.pfd.pf);
5452 if (c && c->pending_eof) {
5454 * We have a pending close on this channel,
5455 * which we decided on before the server acked
5456 * the channel open. So now we know the
5457 * remoteid, we can close it again.
5459 ssh_channel_try_eof(c);
5463 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5465 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5466 struct ssh_channel *c;
5468 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5469 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5470 logevent("Forwarded connection refused by server");
5471 pfd_close(c->u.pfd.pf);
5472 del234(ssh->channels, c);
5477 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
5479 /* Remote side closes a channel. */
5480 unsigned i = ssh_pkt_getuint32(pktin);
5481 struct ssh_channel *c;
5482 c = find234(ssh->channels, &i, ssh_channelfind);
5483 if (c && !c->halfopen) {
5485 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
5486 !(c->closes & CLOSES_RCVD_EOF)) {
5488 * Received CHANNEL_CLOSE, which we translate into
5491 int send_close = FALSE;
5493 c->closes |= CLOSES_RCVD_EOF;
5498 x11_send_eof(c->u.x11.xconn);
5504 pfd_send_eof(c->u.pfd.pf);
5513 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
5514 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
5516 c->closes |= CLOSES_SENT_EOF;
5520 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
5521 !(c->closes & CLOSES_RCVD_CLOSE)) {
5523 if (!(c->closes & CLOSES_SENT_EOF)) {
5524 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
5525 " for which we never sent CHANNEL_CLOSE\n", i));
5528 c->closes |= CLOSES_RCVD_CLOSE;
5531 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
5532 !(c->closes & CLOSES_SENT_CLOSE)) {
5533 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
5534 PKT_INT, c->remoteid, PKT_END);
5535 c->closes |= CLOSES_SENT_CLOSE;
5538 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5539 ssh_channel_destroy(c);
5541 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5542 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
5543 "_CONFIRMATION", c ? "half-open" : "nonexistent",
5548 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5550 /* Data sent down one of our channels. */
5551 int i = ssh_pkt_getuint32(pktin);
5554 struct ssh_channel *c;
5556 ssh_pkt_getstring(pktin, &p, &len);
5558 c = find234(ssh->channels, &i, ssh_channelfind);
5563 bufsize = x11_send(c->u.x11.xconn, p, len);
5566 bufsize = pfd_send(c->u.pfd.pf, p, len);
5569 /* Data for an agent message. Buffer it. */
5571 if (c->u.a.lensofar < 4) {
5572 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
5573 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
5577 c->u.a.lensofar += l;
5579 if (c->u.a.lensofar == 4) {
5581 4 + GET_32BIT(c->u.a.msglen);
5582 c->u.a.message = snewn(c->u.a.totallen,
5584 memcpy(c->u.a.message, c->u.a.msglen, 4);
5586 if (c->u.a.lensofar >= 4 && len > 0) {
5588 min(c->u.a.totallen - c->u.a.lensofar,
5590 memcpy(c->u.a.message + c->u.a.lensofar, p,
5594 c->u.a.lensofar += l;
5596 if (c->u.a.lensofar == c->u.a.totallen) {
5599 c->u.a.outstanding_requests++;
5600 if (agent_query(c->u.a.message,
5603 ssh_agentf_callback, c))
5604 ssh_agentf_callback(c, reply, replylen);
5605 sfree(c->u.a.message);
5606 c->u.a.lensofar = 0;
5609 bufsize = 0; /* agent channels never back up */
5612 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5613 c->throttling_conn = 1;
5614 ssh_throttle_conn(ssh, +1);
5619 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5621 ssh->exitcode = ssh_pkt_getuint32(pktin);
5622 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5623 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5625 * In case `helpful' firewalls or proxies tack
5626 * extra human-readable text on the end of the
5627 * session which we might mistake for another
5628 * encrypted packet, we close the session once
5629 * we've sent EXIT_CONFIRMATION.
5631 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5634 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5635 static void ssh1_send_ttymode(void *data, char *mode, char *val)
5637 struct Packet *pktout = (struct Packet *)data;
5639 unsigned int arg = 0;
5640 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5641 if (i == lenof(ssh_ttymodes)) return;
5642 switch (ssh_ttymodes[i].type) {
5644 arg = ssh_tty_parse_specchar(val);
5647 arg = ssh_tty_parse_boolean(val);
5650 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5651 ssh2_pkt_addbyte(pktout, arg);
5654 int ssh_agent_forwarding_permitted(Ssh ssh)
5656 return conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists();
5659 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
5660 struct Packet *pktin)
5662 crBegin(ssh->do_ssh1_connection_crstate);
5664 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5665 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5666 ssh1_smsg_stdout_stderr_data;
5668 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5669 ssh1_msg_channel_open_confirmation;
5670 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5671 ssh1_msg_channel_open_failure;
5672 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5673 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5674 ssh1_msg_channel_close;
5675 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5676 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5678 if (ssh_agent_forwarding_permitted(ssh)) {
5679 logevent("Requesting agent forwarding");
5680 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5684 if (pktin->type != SSH1_SMSG_SUCCESS
5685 && pktin->type != SSH1_SMSG_FAILURE) {
5686 bombout(("Protocol confusion"));
5688 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5689 logevent("Agent forwarding refused");
5691 logevent("Agent forwarding enabled");
5692 ssh->agentfwd_enabled = TRUE;
5693 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5697 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
5699 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5701 if (!ssh->x11disp) {
5702 /* FIXME: return an error message from x11_setup_display */
5703 logevent("X11 forwarding not enabled: unable to"
5704 " initialise X display");
5706 ssh->x11auth = x11_invent_fake_auth
5707 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
5708 ssh->x11auth->disp = ssh->x11disp;
5710 logevent("Requesting X11 forwarding");
5711 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5712 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5713 PKT_STR, ssh->x11auth->protoname,
5714 PKT_STR, ssh->x11auth->datastring,
5715 PKT_INT, ssh->x11disp->screennum,
5718 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5719 PKT_STR, ssh->x11auth->protoname,
5720 PKT_STR, ssh->x11auth->datastring,
5726 if (pktin->type != SSH1_SMSG_SUCCESS
5727 && pktin->type != SSH1_SMSG_FAILURE) {
5728 bombout(("Protocol confusion"));
5730 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5731 logevent("X11 forwarding refused");
5733 logevent("X11 forwarding enabled");
5734 ssh->X11_fwd_enabled = TRUE;
5735 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5740 ssh_setup_portfwd(ssh, ssh->conf);
5741 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5743 if (!conf_get_int(ssh->conf, CONF_nopty)) {
5745 /* Unpick the terminal-speed string. */
5746 /* XXX perhaps we should allow no speeds to be sent. */
5747 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5748 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
5749 /* Send the pty request. */
5750 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5751 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
5752 ssh_pkt_adduint32(pkt, ssh->term_height);
5753 ssh_pkt_adduint32(pkt, ssh->term_width);
5754 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5755 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5756 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
5757 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5758 ssh_pkt_adduint32(pkt, ssh->ispeed);
5759 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5760 ssh_pkt_adduint32(pkt, ssh->ospeed);
5761 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5763 ssh->state = SSH_STATE_INTERMED;
5767 if (pktin->type != SSH1_SMSG_SUCCESS
5768 && pktin->type != SSH1_SMSG_FAILURE) {
5769 bombout(("Protocol confusion"));
5771 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5772 c_write_str(ssh, "Server refused to allocate pty\r\n");
5773 ssh->editing = ssh->echoing = 1;
5775 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5776 ssh->ospeed, ssh->ispeed);
5777 ssh->got_pty = TRUE;
5780 ssh->editing = ssh->echoing = 1;
5783 if (conf_get_int(ssh->conf, CONF_compression)) {
5784 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5788 if (pktin->type != SSH1_SMSG_SUCCESS
5789 && pktin->type != SSH1_SMSG_FAILURE) {
5790 bombout(("Protocol confusion"));
5792 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5793 c_write_str(ssh, "Server refused to compress\r\n");
5795 logevent("Started compression");
5796 ssh->v1_compressing = TRUE;
5797 ssh->cs_comp_ctx = zlib_compress_init();
5798 logevent("Initialised zlib (RFC1950) compression");
5799 ssh->sc_comp_ctx = zlib_decompress_init();
5800 logevent("Initialised zlib (RFC1950) decompression");
5804 * Start the shell or command.
5806 * Special case: if the first-choice command is an SSH-2
5807 * subsystem (hence not usable here) and the second choice
5808 * exists, we fall straight back to that.
5811 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
5813 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
5814 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
5815 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
5816 ssh->fallback_cmd = TRUE;
5819 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
5821 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
5822 logevent("Started session");
5825 ssh->state = SSH_STATE_SESSION;
5826 if (ssh->size_needed)
5827 ssh_size(ssh, ssh->term_width, ssh->term_height);
5828 if (ssh->eof_needed)
5829 ssh_special(ssh, TS_EOF);
5832 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5834 ssh->channels = newtree234(ssh_channelcmp);
5838 * By this point, most incoming packets are already being
5839 * handled by the dispatch table, and we need only pay
5840 * attention to the unusual ones.
5845 if (pktin->type == SSH1_SMSG_SUCCESS) {
5846 /* may be from EXEC_SHELL on some servers */
5847 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5848 /* may be from EXEC_SHELL on some servers
5849 * if no pty is available or in other odd cases. Ignore */
5851 bombout(("Strange packet received: type %d", pktin->type));
5856 int len = min(inlen, 512);
5857 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
5858 PKT_INT, len, PKT_DATA, in, len,
5870 * Handle the top-level SSH-2 protocol.
5872 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
5877 ssh_pkt_getstring(pktin, &msg, &msglen);
5878 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
5881 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
5883 /* log reason code in disconnect message */
5887 ssh_pkt_getstring(pktin, &msg, &msglen);
5888 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
5891 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
5893 /* Do nothing, because we're ignoring it! Duhh. */
5896 static void ssh1_protocol_setup(Ssh ssh)
5901 * Most messages are handled by the coroutines.
5903 for (i = 0; i < 256; i++)
5904 ssh->packet_dispatch[i] = NULL;
5907 * These special message types we install handlers for.
5909 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
5910 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
5911 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
5914 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
5915 struct Packet *pktin)
5917 unsigned char *in=(unsigned char*)vin;
5918 if (ssh->state == SSH_STATE_CLOSED)
5921 if (pktin && ssh->packet_dispatch[pktin->type]) {
5922 ssh->packet_dispatch[pktin->type](ssh, pktin);
5926 if (!ssh->protocol_initial_phase_done) {
5927 if (do_ssh1_login(ssh, in, inlen, pktin))
5928 ssh->protocol_initial_phase_done = TRUE;
5933 do_ssh1_connection(ssh, in, inlen, pktin);
5937 * Utility routine for decoding comma-separated strings in KEXINIT.
5939 static int in_commasep_string(char const *needle, char const *haystack,
5943 if (!needle || !haystack) /* protect against null pointers */
5945 needlen = strlen(needle);
5948 * Is it at the start of the string?
5950 if (haylen >= needlen && /* haystack is long enough */
5951 !memcmp(needle, haystack, needlen) && /* initial match */
5952 (haylen == needlen || haystack[needlen] == ',')
5953 /* either , or EOS follows */
5957 * If not, search for the next comma and resume after that.
5958 * If no comma found, terminate.
5960 while (haylen > 0 && *haystack != ',')
5961 haylen--, haystack++;
5964 haylen--, haystack++; /* skip over comma itself */
5969 * Similar routine for checking whether we have the first string in a list.
5971 static int first_in_commasep_string(char const *needle, char const *haystack,
5975 if (!needle || !haystack) /* protect against null pointers */
5977 needlen = strlen(needle);
5979 * Is it at the start of the string?
5981 if (haylen >= needlen && /* haystack is long enough */
5982 !memcmp(needle, haystack, needlen) && /* initial match */
5983 (haylen == needlen || haystack[needlen] == ',')
5984 /* either , or EOS follows */
5991 * Add a value to the comma-separated string at the end of the packet.
5992 * If the value is already in the string, don't bother adding it again.
5994 static void ssh2_pkt_addstring_commasep(struct Packet *pkt, const char *data)
5996 if (in_commasep_string(data, (char *)pkt->data + pkt->savedpos,
5997 pkt->length - pkt->savedpos)) return;
5998 if (pkt->length - pkt->savedpos > 0)
5999 ssh_pkt_addstring_str(pkt, ",");
6000 ssh_pkt_addstring_str(pkt, data);
6005 * SSH-2 key creation method.
6006 * (Currently assumes 2 lots of any hash are sufficient to generate
6007 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
6009 #define SSH2_MKKEY_ITERS (2)
6010 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
6011 unsigned char *keyspace)
6013 const struct ssh_hash *h = ssh->kex->hash;
6015 /* First hlen bytes. */
6017 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6018 hash_mpint(h, s, K);
6019 h->bytes(s, H, h->hlen);
6020 h->bytes(s, &chr, 1);
6021 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
6022 h->final(s, keyspace);
6023 /* Next hlen bytes. */
6025 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6026 hash_mpint(h, s, K);
6027 h->bytes(s, H, h->hlen);
6028 h->bytes(s, keyspace, h->hlen);
6029 h->final(s, keyspace + h->hlen);
6033 * Handle the SSH-2 transport layer.
6035 static void do_ssh2_transport(Ssh ssh, void *vin, int inlen,
6036 struct Packet *pktin)
6038 unsigned char *in = (unsigned char *)vin;
6039 struct do_ssh2_transport_state {
6041 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
6042 Bignum p, g, e, f, K;
6045 int kex_init_value, kex_reply_value;
6046 const struct ssh_mac **maclist;
6048 const struct ssh2_cipher *cscipher_tobe;
6049 const struct ssh2_cipher *sccipher_tobe;
6050 const struct ssh_mac *csmac_tobe;
6051 const struct ssh_mac *scmac_tobe;
6052 const struct ssh_compress *cscomp_tobe;
6053 const struct ssh_compress *sccomp_tobe;
6054 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
6055 int hostkeylen, siglen, rsakeylen;
6056 void *hkey; /* actual host key */
6057 void *rsakey; /* for RSA kex */
6058 void *eckey; /* for ECDH kex */
6059 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
6060 int n_preferred_kex;
6061 const struct ssh_kexes *preferred_kex[KEX_MAX];
6062 int n_preferred_ciphers;
6063 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
6064 const struct ssh_compress *preferred_comp;
6065 int userauth_succeeded; /* for delayed compression */
6066 int pending_compression;
6067 int got_session_id, activated_authconn;
6068 struct Packet *pktout;
6073 crState(do_ssh2_transport_state);
6075 assert(!ssh->bare_connection);
6079 s->cscipher_tobe = s->sccipher_tobe = NULL;
6080 s->csmac_tobe = s->scmac_tobe = NULL;
6081 s->cscomp_tobe = s->sccomp_tobe = NULL;
6083 s->got_session_id = s->activated_authconn = FALSE;
6084 s->userauth_succeeded = FALSE;
6085 s->pending_compression = FALSE;
6088 * Be prepared to work around the buggy MAC problem.
6090 if (ssh->remote_bugs & BUG_SSH2_HMAC)
6091 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
6093 s->maclist = macs, s->nmacs = lenof(macs);
6096 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
6101 * Set up the preferred key exchange. (NULL => warn below here)
6103 s->n_preferred_kex = 0;
6104 for (i = 0; i < KEX_MAX; i++) {
6105 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
6107 s->preferred_kex[s->n_preferred_kex++] =
6108 &ssh_diffiehellman_gex;
6111 s->preferred_kex[s->n_preferred_kex++] =
6112 &ssh_diffiehellman_group14;
6115 s->preferred_kex[s->n_preferred_kex++] =
6116 &ssh_diffiehellman_group1;
6119 s->preferred_kex[s->n_preferred_kex++] =
6123 s->preferred_kex[s->n_preferred_kex++] =
6127 /* Flag for later. Don't bother if it's the last in
6129 if (i < KEX_MAX - 1) {
6130 s->preferred_kex[s->n_preferred_kex++] = NULL;
6137 * Set up the preferred ciphers. (NULL => warn below here)
6139 s->n_preferred_ciphers = 0;
6140 for (i = 0; i < CIPHER_MAX; i++) {
6141 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
6142 case CIPHER_BLOWFISH:
6143 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
6146 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
6147 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
6151 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
6154 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
6156 case CIPHER_ARCFOUR:
6157 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
6160 /* Flag for later. Don't bother if it's the last in
6162 if (i < CIPHER_MAX - 1) {
6163 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
6170 * Set up preferred compression.
6172 if (conf_get_int(ssh->conf, CONF_compression))
6173 s->preferred_comp = &ssh_zlib;
6175 s->preferred_comp = &ssh_comp_none;
6178 * Enable queueing of outgoing auth- or connection-layer
6179 * packets while we are in the middle of a key exchange.
6181 ssh->queueing = TRUE;
6184 * Flag that KEX is in progress.
6186 ssh->kex_in_progress = TRUE;
6189 * Construct and send our key exchange packet.
6191 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
6192 for (i = 0; i < 16; i++)
6193 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
6194 /* List key exchange algorithms. */
6195 ssh2_pkt_addstring_start(s->pktout);
6196 for (i = 0; i < s->n_preferred_kex; i++) {
6197 const struct ssh_kexes *k = s->preferred_kex[i];
6198 if (!k) continue; /* warning flag */
6199 for (j = 0; j < k->nkexes; j++)
6200 ssh2_pkt_addstring_commasep(s->pktout, k->list[j]->name);
6202 /* List server host key algorithms. */
6203 if (!s->got_session_id) {
6205 * In the first key exchange, we list all the algorithms
6206 * we're prepared to cope with.
6208 ssh2_pkt_addstring_start(s->pktout);
6209 for (i = 0; i < lenof(hostkey_algs); i++)
6210 ssh2_pkt_addstring_commasep(s->pktout, hostkey_algs[i]->name);
6213 * In subsequent key exchanges, we list only the kex
6214 * algorithm that was selected in the first key exchange,
6215 * so that we keep getting the same host key and hence
6216 * don't have to interrupt the user's session to ask for
6220 ssh2_pkt_addstring(s->pktout, ssh->hostkey->name);
6222 /* List encryption algorithms (client->server then server->client). */
6223 for (k = 0; k < 2; k++) {
6224 ssh2_pkt_addstring_start(s->pktout);
6225 for (i = 0; i < s->n_preferred_ciphers; i++) {
6226 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6227 if (!c) continue; /* warning flag */
6228 for (j = 0; j < c->nciphers; j++)
6229 ssh2_pkt_addstring_commasep(s->pktout, c->list[j]->name);
6232 /* List MAC algorithms (client->server then server->client). */
6233 for (j = 0; j < 2; j++) {
6234 ssh2_pkt_addstring_start(s->pktout);
6235 for (i = 0; i < s->nmacs; i++)
6236 ssh2_pkt_addstring_commasep(s->pktout, s->maclist[i]->name);
6238 /* List client->server compression algorithms,
6239 * then server->client compression algorithms. (We use the
6240 * same set twice.) */
6241 for (j = 0; j < 2; j++) {
6242 ssh2_pkt_addstring_start(s->pktout);
6243 assert(lenof(compressions) > 1);
6244 /* Prefer non-delayed versions */
6245 ssh2_pkt_addstring_commasep(s->pktout, s->preferred_comp->name);
6246 /* We don't even list delayed versions of algorithms until
6247 * they're allowed to be used, to avoid a race. See the end of
6249 if (s->userauth_succeeded && s->preferred_comp->delayed_name)
6250 ssh2_pkt_addstring_commasep(s->pktout,
6251 s->preferred_comp->delayed_name);
6252 for (i = 0; i < lenof(compressions); i++) {
6253 const struct ssh_compress *c = compressions[i];
6254 ssh2_pkt_addstring_commasep(s->pktout, c->name);
6255 if (s->userauth_succeeded && c->delayed_name)
6256 ssh2_pkt_addstring_commasep(s->pktout, c->delayed_name);
6259 /* List client->server languages. Empty list. */
6260 ssh2_pkt_addstring_start(s->pktout);
6261 /* List server->client languages. Empty list. */
6262 ssh2_pkt_addstring_start(s->pktout);
6263 /* First KEX packet does _not_ follow, because we're not that brave. */
6264 ssh2_pkt_addbool(s->pktout, FALSE);
6266 ssh2_pkt_adduint32(s->pktout, 0);
6269 s->our_kexinitlen = s->pktout->length - 5;
6270 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
6271 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
6273 ssh2_pkt_send_noqueue(ssh, s->pktout);
6276 crWaitUntilV(pktin);
6279 * Now examine the other side's KEXINIT to see what we're up
6283 char *str, *preferred;
6286 if (pktin->type != SSH2_MSG_KEXINIT) {
6287 bombout(("expected key exchange packet from server"));
6291 ssh->hostkey = NULL;
6292 s->cscipher_tobe = NULL;
6293 s->sccipher_tobe = NULL;
6294 s->csmac_tobe = NULL;
6295 s->scmac_tobe = NULL;
6296 s->cscomp_tobe = NULL;
6297 s->sccomp_tobe = NULL;
6298 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
6300 pktin->savedpos += 16; /* skip garbage cookie */
6301 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
6303 bombout(("KEXINIT packet was incomplete"));
6308 for (i = 0; i < s->n_preferred_kex; i++) {
6309 const struct ssh_kexes *k = s->preferred_kex[i];
6313 for (j = 0; j < k->nkexes; j++) {
6314 if (!preferred) preferred = k->list[j]->name;
6315 if (in_commasep_string(k->list[j]->name, str, len)) {
6316 ssh->kex = k->list[j];
6325 bombout(("Couldn't agree a key exchange algorithm"
6326 " (available: %.*s)", len, str));
6330 * Note that the server's guess is considered wrong if it doesn't match
6331 * the first algorithm in our list, even if it's still the algorithm
6334 s->guessok = first_in_commasep_string(preferred, str, len);
6335 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
6337 bombout(("KEXINIT packet was incomplete"));
6340 for (i = 0; i < lenof(hostkey_algs); i++) {
6341 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
6342 ssh->hostkey = hostkey_algs[i];
6346 if (!ssh->hostkey) {
6347 bombout(("Couldn't agree a host key algorithm"
6348 " (available: %.*s)", len, str));
6352 s->guessok = s->guessok &&
6353 first_in_commasep_string(hostkey_algs[0]->name, str, len);
6354 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
6356 bombout(("KEXINIT packet was incomplete"));
6359 for (i = 0; i < s->n_preferred_ciphers; i++) {
6360 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6362 s->warn_cscipher = TRUE;
6364 for (j = 0; j < c->nciphers; j++) {
6365 if (in_commasep_string(c->list[j]->name, str, len)) {
6366 s->cscipher_tobe = c->list[j];
6371 if (s->cscipher_tobe)
6374 if (!s->cscipher_tobe) {
6375 bombout(("Couldn't agree a client-to-server cipher"
6376 " (available: %.*s)", len, str));
6380 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
6382 bombout(("KEXINIT packet was incomplete"));
6385 for (i = 0; i < s->n_preferred_ciphers; i++) {
6386 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6388 s->warn_sccipher = TRUE;
6390 for (j = 0; j < c->nciphers; j++) {
6391 if (in_commasep_string(c->list[j]->name, str, len)) {
6392 s->sccipher_tobe = c->list[j];
6397 if (s->sccipher_tobe)
6400 if (!s->sccipher_tobe) {
6401 bombout(("Couldn't agree a server-to-client cipher"
6402 " (available: %.*s)", len, str));
6406 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
6408 bombout(("KEXINIT packet was incomplete"));
6411 for (i = 0; i < s->nmacs; i++) {
6412 if (in_commasep_string(s->maclist[i]->name, str, len)) {
6413 s->csmac_tobe = s->maclist[i];
6417 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
6419 bombout(("KEXINIT packet was incomplete"));
6422 for (i = 0; i < s->nmacs; i++) {
6423 if (in_commasep_string(s->maclist[i]->name, str, len)) {
6424 s->scmac_tobe = s->maclist[i];
6428 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
6430 bombout(("KEXINIT packet was incomplete"));
6433 for (i = 0; i < lenof(compressions) + 1; i++) {
6434 const struct ssh_compress *c =
6435 i == 0 ? s->preferred_comp : compressions[i - 1];
6436 if (in_commasep_string(c->name, str, len)) {
6439 } else if (in_commasep_string(c->delayed_name, str, len)) {
6440 if (s->userauth_succeeded) {
6444 s->pending_compression = TRUE; /* try this later */
6448 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
6450 bombout(("KEXINIT packet was incomplete"));
6453 for (i = 0; i < lenof(compressions) + 1; i++) {
6454 const struct ssh_compress *c =
6455 i == 0 ? s->preferred_comp : compressions[i - 1];
6456 if (in_commasep_string(c->name, str, len)) {
6459 } else if (in_commasep_string(c->delayed_name, str, len)) {
6460 if (s->userauth_succeeded) {
6464 s->pending_compression = TRUE; /* try this later */
6468 if (s->pending_compression) {
6469 logevent("Server supports delayed compression; "
6470 "will try this later");
6472 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
6473 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
6474 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
6476 ssh->exhash = ssh->kex->hash->init();
6477 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
6478 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
6479 hash_string(ssh->kex->hash, ssh->exhash,
6480 s->our_kexinit, s->our_kexinitlen);
6481 sfree(s->our_kexinit);
6482 /* Include the type byte in the hash of server's KEXINIT */
6483 hash_string(ssh->kex->hash, ssh->exhash,
6484 pktin->body - 1, pktin->length + 1);
6487 ssh_set_frozen(ssh, 1);
6488 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
6490 ssh_dialog_callback, ssh);
6491 if (s->dlgret < 0) {
6495 bombout(("Unexpected data from server while"
6496 " waiting for user response"));
6499 } while (pktin || inlen > 0);
6500 s->dlgret = ssh->user_response;
6502 ssh_set_frozen(ssh, 0);
6503 if (s->dlgret == 0) {
6504 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
6510 if (s->warn_cscipher) {
6511 ssh_set_frozen(ssh, 1);
6512 s->dlgret = askalg(ssh->frontend,
6513 "client-to-server cipher",
6514 s->cscipher_tobe->name,
6515 ssh_dialog_callback, ssh);
6516 if (s->dlgret < 0) {
6520 bombout(("Unexpected data from server while"
6521 " waiting for user response"));
6524 } while (pktin || inlen > 0);
6525 s->dlgret = ssh->user_response;
6527 ssh_set_frozen(ssh, 0);
6528 if (s->dlgret == 0) {
6529 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6535 if (s->warn_sccipher) {
6536 ssh_set_frozen(ssh, 1);
6537 s->dlgret = askalg(ssh->frontend,
6538 "server-to-client cipher",
6539 s->sccipher_tobe->name,
6540 ssh_dialog_callback, ssh);
6541 if (s->dlgret < 0) {
6545 bombout(("Unexpected data from server while"
6546 " waiting for user response"));
6549 } while (pktin || inlen > 0);
6550 s->dlgret = ssh->user_response;
6552 ssh_set_frozen(ssh, 0);
6553 if (s->dlgret == 0) {
6554 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6560 if (s->ignorepkt) /* first_kex_packet_follows */
6561 crWaitUntilV(pktin); /* Ignore packet */
6564 if (ssh->kex->main_type == KEXTYPE_DH) {
6566 * Work out the number of bits of key we will need from the
6567 * key exchange. We start with the maximum key length of
6573 csbits = s->cscipher_tobe->keylen;
6574 scbits = s->sccipher_tobe->keylen;
6575 s->nbits = (csbits > scbits ? csbits : scbits);
6577 /* The keys only have hlen-bit entropy, since they're based on
6578 * a hash. So cap the key size at hlen bits. */
6579 if (s->nbits > ssh->kex->hash->hlen * 8)
6580 s->nbits = ssh->kex->hash->hlen * 8;
6583 * If we're doing Diffie-Hellman group exchange, start by
6584 * requesting a group.
6586 if (!ssh->kex->pdata) {
6587 logevent("Doing Diffie-Hellman group exchange");
6588 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
6590 * Work out how big a DH group we will need to allow that
6593 s->pbits = 512 << ((s->nbits - 1) / 64);
6594 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6595 ssh2_pkt_adduint32(s->pktout, s->pbits);
6596 ssh2_pkt_send_noqueue(ssh, s->pktout);
6598 crWaitUntilV(pktin);
6599 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6600 bombout(("expected key exchange group packet from server"));
6603 s->p = ssh2_pkt_getmp(pktin);
6604 s->g = ssh2_pkt_getmp(pktin);
6605 if (!s->p || !s->g) {
6606 bombout(("unable to read mp-ints from incoming group packet"));
6609 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6610 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6611 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6613 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
6614 ssh->kex_ctx = dh_setup_group(ssh->kex);
6615 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6616 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6617 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6618 ssh->kex->groupname);
6621 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6622 ssh->kex->hash->text_name);
6624 * Now generate and send e for Diffie-Hellman.
6626 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6627 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6628 s->pktout = ssh2_pkt_init(s->kex_init_value);
6629 ssh2_pkt_addmp(s->pktout, s->e);
6630 ssh2_pkt_send_noqueue(ssh, s->pktout);
6632 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
6633 crWaitUntilV(pktin);
6634 if (pktin->type != s->kex_reply_value) {
6635 bombout(("expected key exchange reply packet from server"));
6638 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
6639 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6640 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6641 s->f = ssh2_pkt_getmp(pktin);
6643 bombout(("unable to parse key exchange reply packet"));
6646 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6648 s->K = dh_find_K(ssh->kex_ctx, s->f);
6650 /* We assume everything from now on will be quick, and it might
6651 * involve user interaction. */
6652 set_busy_status(ssh->frontend, BUSY_NOT);
6654 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6655 if (!ssh->kex->pdata) {
6656 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
6657 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
6658 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
6660 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
6661 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
6663 dh_cleanup(ssh->kex_ctx);
6665 if (!ssh->kex->pdata) {
6669 } else if (ssh->kex->main_type == KEXTYPE_ECDH) {
6671 logeventf(ssh, "Doing ECDH key exchange with hash %s",
6672 ssh->kex->hash->text_name);
6673 ssh->pkt_kctx = SSH2_PKTCTX_ECDHKEX;
6676 if (!strcmp(ssh->kex->name, "ecdh-sha2-nistp256")) {
6677 s->eckey = ssh_ecdhkex_newkey(ec_p256());
6678 } else if (!strcmp(ssh->kex->name, "ecdh-sha2-nistp384")) {
6679 s->eckey = ssh_ecdhkex_newkey(ec_p384());
6680 } else if (!strcmp(ssh->kex->name, "ecdh-sha2-nistp521")) {
6681 s->eckey = ssh_ecdhkex_newkey(ec_p521());
6684 bombout(("Unable to generate key for ECDH"));
6690 int publicPointLength;
6691 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
6693 ssh_ecdhkex_freekey(s->eckey);
6694 bombout(("Unable to encode public key for ECDH"));
6697 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_ECDH_INIT);
6698 ssh2_pkt_addstring_start(s->pktout);
6699 ssh2_pkt_addstring_data(s->pktout, publicPoint, publicPointLength);
6703 ssh2_pkt_send_noqueue(ssh, s->pktout);
6705 crWaitUntilV(pktin);
6706 if (pktin->type != SSH2_MSG_KEX_ECDH_REPLY) {
6707 ssh_ecdhkex_freekey(s->eckey);
6708 bombout(("expected ECDH reply packet from server"));
6712 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6713 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6714 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6718 int publicPointLength;
6719 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
6721 ssh_ecdhkex_freekey(s->eckey);
6722 bombout(("Unable to encode public key for ECDH hash"));
6725 hash_string(ssh->kex->hash, ssh->exhash,
6726 publicPoint, publicPointLength);
6733 ssh_pkt_getstring(pktin, &keydata, &keylen);
6734 hash_string(ssh->kex->hash, ssh->exhash, keydata, keylen);
6735 s->K = ssh_ecdhkex_getkey(s->eckey, keydata, keylen);
6737 ssh_ecdhkex_freekey(s->eckey);
6738 bombout(("point received in ECDH was not valid"));
6743 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6745 ssh_ecdhkex_freekey(s->eckey);
6747 logeventf(ssh, "Doing RSA key exchange with hash %s",
6748 ssh->kex->hash->text_name);
6749 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
6751 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6754 crWaitUntilV(pktin);
6755 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
6756 bombout(("expected RSA public key packet from server"));
6760 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6761 hash_string(ssh->kex->hash, ssh->exhash,
6762 s->hostkeydata, s->hostkeylen);
6763 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6767 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
6768 s->rsakeydata = snewn(s->rsakeylen, char);
6769 memcpy(s->rsakeydata, keydata, s->rsakeylen);
6772 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
6774 sfree(s->rsakeydata);
6775 bombout(("unable to parse RSA public key from server"));
6779 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
6782 * Next, set up a shared secret K, of precisely KLEN -
6783 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6784 * RSA key modulus and HLEN is the bit length of the hash
6788 int klen = ssh_rsakex_klen(s->rsakey);
6789 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
6791 unsigned char *kstr1, *kstr2, *outstr;
6792 int kstr1len, kstr2len, outstrlen;
6794 s->K = bn_power_2(nbits - 1);
6796 for (i = 0; i < nbits; i++) {
6798 byte = random_byte();
6800 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
6804 * Encode this as an mpint.
6806 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
6807 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
6808 PUT_32BIT(kstr2, kstr1len);
6809 memcpy(kstr2 + 4, kstr1, kstr1len);
6812 * Encrypt it with the given RSA key.
6814 outstrlen = (klen + 7) / 8;
6815 outstr = snewn(outstrlen, unsigned char);
6816 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
6817 outstr, outstrlen, s->rsakey);
6820 * And send it off in a return packet.
6822 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
6823 ssh2_pkt_addstring_start(s->pktout);
6824 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
6825 ssh2_pkt_send_noqueue(ssh, s->pktout);
6827 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
6834 ssh_rsakex_freekey(s->rsakey);
6836 crWaitUntilV(pktin);
6837 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
6838 sfree(s->rsakeydata);
6839 bombout(("expected signature packet from server"));
6843 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6845 sfree(s->rsakeydata);
6848 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
6849 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
6850 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
6852 ssh->kex_ctx = NULL;
6855 debug(("Exchange hash is:\n"));
6856 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
6860 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
6861 (char *)s->exchange_hash,
6862 ssh->kex->hash->hlen)) {
6863 bombout(("Server's host key did not match the signature supplied"));
6867 s->keystr = ssh->hostkey->fmtkey(s->hkey);
6868 if (!s->got_session_id) {
6870 * Authenticate remote host: verify host key. (We've already
6871 * checked the signature of the exchange hash.)
6873 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
6874 logevent("Host key fingerprint is:");
6875 logevent(s->fingerprint);
6876 /* First check against manually configured host keys. */
6877 s->dlgret = verify_ssh_manual_host_key(ssh, s->fingerprint,
6878 ssh->hostkey, s->hkey);
6879 if (s->dlgret == 0) { /* did not match */
6880 bombout(("Host key did not appear in manually configured list"));
6882 } else if (s->dlgret < 0) { /* none configured; use standard handling */
6883 ssh_set_frozen(ssh, 1);
6884 s->dlgret = verify_ssh_host_key(ssh->frontend,
6885 ssh->savedhost, ssh->savedport,
6886 ssh->hostkey->keytype, s->keystr,
6888 ssh_dialog_callback, ssh);
6889 if (s->dlgret < 0) {
6893 bombout(("Unexpected data from server while waiting"
6894 " for user host key response"));
6897 } while (pktin || inlen > 0);
6898 s->dlgret = ssh->user_response;
6900 ssh_set_frozen(ssh, 0);
6901 if (s->dlgret == 0) {
6902 ssh_disconnect(ssh, "Aborted at host key verification", NULL,
6907 sfree(s->fingerprint);
6909 * Save this host key, to check against the one presented in
6910 * subsequent rekeys.
6912 ssh->hostkey_str = s->keystr;
6915 * In a rekey, we never present an interactive host key
6916 * verification request to the user. Instead, we simply
6917 * enforce that the key we're seeing this time is identical to
6918 * the one we saw before.
6920 if (strcmp(ssh->hostkey_str, s->keystr)) {
6921 bombout(("Host key was different in repeat key exchange"));
6926 ssh->hostkey->freekey(s->hkey);
6929 * The exchange hash from the very first key exchange is also
6930 * the session id, used in session key construction and
6933 if (!s->got_session_id) {
6934 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
6935 memcpy(ssh->v2_session_id, s->exchange_hash,
6936 sizeof(s->exchange_hash));
6937 ssh->v2_session_id_len = ssh->kex->hash->hlen;
6938 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
6939 s->got_session_id = TRUE;
6943 * Send SSH2_MSG_NEWKEYS.
6945 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
6946 ssh2_pkt_send_noqueue(ssh, s->pktout);
6947 ssh->outgoing_data_size = 0; /* start counting from here */
6950 * We've sent client NEWKEYS, so create and initialise
6951 * client-to-server session keys.
6953 if (ssh->cs_cipher_ctx)
6954 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6955 ssh->cscipher = s->cscipher_tobe;
6956 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
6958 if (ssh->cs_mac_ctx)
6959 ssh->csmac->free_context(ssh->cs_mac_ctx);
6960 ssh->csmac = s->csmac_tobe;
6961 ssh->cs_mac_ctx = ssh->csmac->make_context();
6963 if (ssh->cs_comp_ctx)
6964 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6965 ssh->cscomp = s->cscomp_tobe;
6966 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
6969 * Set IVs on client-to-server keys. Here we use the exchange
6970 * hash from the _first_ key exchange.
6973 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6974 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6975 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
6976 assert((ssh->cscipher->keylen+7) / 8 <=
6977 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6978 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
6979 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
6980 assert(ssh->cscipher->blksize <=
6981 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6982 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
6983 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
6984 assert(ssh->csmac->len <=
6985 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6986 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
6987 smemclr(keyspace, sizeof(keyspace));
6990 logeventf(ssh, "Initialised %.200s client->server encryption",
6991 ssh->cscipher->text_name);
6992 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
6993 ssh->csmac->text_name);
6994 if (ssh->cscomp->text_name)
6995 logeventf(ssh, "Initialised %s compression",
6996 ssh->cscomp->text_name);
6999 * Now our end of the key exchange is complete, we can send all
7000 * our queued higher-layer packets.
7002 ssh->queueing = FALSE;
7003 ssh2_pkt_queuesend(ssh);
7006 * Expect SSH2_MSG_NEWKEYS from server.
7008 crWaitUntilV(pktin);
7009 if (pktin->type != SSH2_MSG_NEWKEYS) {
7010 bombout(("expected new-keys packet from server"));
7013 ssh->incoming_data_size = 0; /* start counting from here */
7016 * We've seen server NEWKEYS, so create and initialise
7017 * server-to-client session keys.
7019 if (ssh->sc_cipher_ctx)
7020 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7021 ssh->sccipher = s->sccipher_tobe;
7022 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
7024 if (ssh->sc_mac_ctx)
7025 ssh->scmac->free_context(ssh->sc_mac_ctx);
7026 ssh->scmac = s->scmac_tobe;
7027 ssh->sc_mac_ctx = ssh->scmac->make_context();
7029 if (ssh->sc_comp_ctx)
7030 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7031 ssh->sccomp = s->sccomp_tobe;
7032 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
7035 * Set IVs on server-to-client keys. Here we use the exchange
7036 * hash from the _first_ key exchange.
7039 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
7040 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7041 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
7042 assert((ssh->sccipher->keylen+7) / 8 <=
7043 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7044 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
7045 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
7046 assert(ssh->sccipher->blksize <=
7047 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7048 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
7049 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
7050 assert(ssh->scmac->len <=
7051 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7052 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
7053 smemclr(keyspace, sizeof(keyspace));
7055 logeventf(ssh, "Initialised %.200s server->client encryption",
7056 ssh->sccipher->text_name);
7057 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
7058 ssh->scmac->text_name);
7059 if (ssh->sccomp->text_name)
7060 logeventf(ssh, "Initialised %s decompression",
7061 ssh->sccomp->text_name);
7064 * Free shared secret.
7069 * Key exchange is over. Loop straight back round if we have a
7070 * deferred rekey reason.
7072 if (ssh->deferred_rekey_reason) {
7073 logevent(ssh->deferred_rekey_reason);
7075 ssh->deferred_rekey_reason = NULL;
7076 goto begin_key_exchange;
7080 * Otherwise, schedule a timer for our next rekey.
7082 ssh->kex_in_progress = FALSE;
7083 ssh->last_rekey = GETTICKCOUNT();
7084 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
7085 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7089 * Now we're encrypting. Begin returning 1 to the protocol main
7090 * function so that other things can run on top of the
7091 * transport. If we ever see a KEXINIT, we must go back to the
7094 * We _also_ go back to the start if we see pktin==NULL and
7095 * inlen negative, because this is a special signal meaning
7096 * `initiate client-driven rekey', and `in' contains a message
7097 * giving the reason for the rekey.
7099 * inlen==-1 means always initiate a rekey;
7100 * inlen==-2 means that userauth has completed successfully and
7101 * we should consider rekeying (for delayed compression).
7103 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
7104 (!pktin && inlen < 0))) {
7106 if (!ssh->protocol_initial_phase_done) {
7107 ssh->protocol_initial_phase_done = TRUE;
7109 * Allow authconn to initialise itself.
7111 do_ssh2_authconn(ssh, NULL, 0, NULL);
7116 logevent("Server initiated key re-exchange");
7120 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
7121 * delayed compression, if it's available.
7123 * draft-miller-secsh-compression-delayed-00 says that you
7124 * negotiate delayed compression in the first key exchange, and
7125 * both sides start compressing when the server has sent
7126 * USERAUTH_SUCCESS. This has a race condition -- the server
7127 * can't know when the client has seen it, and thus which incoming
7128 * packets it should treat as compressed.
7130 * Instead, we do the initial key exchange without offering the
7131 * delayed methods, but note if the server offers them; when we
7132 * get here, if a delayed method was available that was higher
7133 * on our list than what we got, we initiate a rekey in which we
7134 * _do_ list the delayed methods (and hopefully get it as a
7135 * result). Subsequent rekeys will do the same.
7137 assert(!s->userauth_succeeded); /* should only happen once */
7138 s->userauth_succeeded = TRUE;
7139 if (!s->pending_compression)
7140 /* Can't see any point rekeying. */
7141 goto wait_for_rekey; /* this is utterly horrid */
7142 /* else fall through to rekey... */
7143 s->pending_compression = FALSE;
7146 * Now we've decided to rekey.
7148 * Special case: if the server bug is set that doesn't
7149 * allow rekeying, we give a different log message and
7150 * continue waiting. (If such a server _initiates_ a rekey,
7151 * we process it anyway!)
7153 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
7154 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
7156 /* Reset the counters, so that at least this message doesn't
7157 * hit the event log _too_ often. */
7158 ssh->outgoing_data_size = 0;
7159 ssh->incoming_data_size = 0;
7160 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
7162 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7165 goto wait_for_rekey; /* this is still utterly horrid */
7167 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
7170 goto begin_key_exchange;
7176 * Add data to an SSH-2 channel output buffer.
7178 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
7181 bufchain_add(&c->v.v2.outbuffer, buf, len);
7185 * Attempt to send data on an SSH-2 channel.
7187 static int ssh2_try_send(struct ssh_channel *c)
7190 struct Packet *pktout;
7193 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
7196 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
7197 if ((unsigned)len > c->v.v2.remwindow)
7198 len = c->v.v2.remwindow;
7199 if ((unsigned)len > c->v.v2.remmaxpkt)
7200 len = c->v.v2.remmaxpkt;
7201 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
7202 ssh2_pkt_adduint32(pktout, c->remoteid);
7203 ssh2_pkt_addstring_start(pktout);
7204 ssh2_pkt_addstring_data(pktout, data, len);
7205 ssh2_pkt_send(ssh, pktout);
7206 bufchain_consume(&c->v.v2.outbuffer, len);
7207 c->v.v2.remwindow -= len;
7211 * After having sent as much data as we can, return the amount
7214 ret = bufchain_size(&c->v.v2.outbuffer);
7217 * And if there's no data pending but we need to send an EOF, send
7220 if (!ret && c->pending_eof)
7221 ssh_channel_try_eof(c);
7226 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
7229 if (c->closes & CLOSES_SENT_EOF)
7230 return; /* don't send on channels we've EOFed */
7231 bufsize = ssh2_try_send(c);
7234 case CHAN_MAINSESSION:
7235 /* stdin need not receive an unthrottle
7236 * notification since it will be polled */
7239 x11_unthrottle(c->u.x11.xconn);
7242 /* agent sockets are request/response and need no
7243 * buffer management */
7246 pfd_unthrottle(c->u.pfd.pf);
7252 static int ssh_is_simple(Ssh ssh)
7255 * We use the 'simple' variant of the SSH protocol if we're asked
7256 * to, except not if we're also doing connection-sharing (either
7257 * tunnelling our packets over an upstream or expecting to be
7258 * tunnelled over ourselves), since then the assumption that we
7259 * have only one channel to worry about is not true after all.
7261 return (conf_get_int(ssh->conf, CONF_ssh_simple) &&
7262 !ssh->bare_connection && !ssh->connshare);
7266 * Set up most of a new ssh_channel for SSH-2.
7268 static void ssh2_channel_init(struct ssh_channel *c)
7271 c->localid = alloc_channel_id(ssh);
7273 c->pending_eof = FALSE;
7274 c->throttling_conn = FALSE;
7275 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
7276 ssh_is_simple(ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
7277 c->v.v2.chanreq_head = NULL;
7278 c->v.v2.throttle_state = UNTHROTTLED;
7279 bufchain_init(&c->v.v2.outbuffer);
7283 * Construct the common parts of a CHANNEL_OPEN.
7285 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c, char *type)
7287 struct Packet *pktout;
7289 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7290 ssh2_pkt_addstring(pktout, type);
7291 ssh2_pkt_adduint32(pktout, c->localid);
7292 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7293 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7298 * CHANNEL_FAILURE doesn't come with any indication of what message
7299 * caused it, so we have to keep track of the outstanding
7300 * CHANNEL_REQUESTs ourselves.
7302 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
7303 cchandler_fn_t handler, void *ctx)
7305 struct outstanding_channel_request *ocr =
7306 snew(struct outstanding_channel_request);
7308 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7309 ocr->handler = handler;
7312 if (!c->v.v2.chanreq_head)
7313 c->v.v2.chanreq_head = ocr;
7315 c->v.v2.chanreq_tail->next = ocr;
7316 c->v.v2.chanreq_tail = ocr;
7320 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
7321 * NULL then a reply will be requested and the handler will be called
7322 * when it arrives. The returned packet is ready to have any
7323 * request-specific data added and be sent. Note that if a handler is
7324 * provided, it's essential that the request actually be sent.
7326 * The handler will usually be passed the response packet in pktin. If
7327 * pktin is NULL, this means that no reply will ever be forthcoming
7328 * (e.g. because the entire connection is being destroyed, or because
7329 * the server initiated channel closure before we saw the response)
7330 * and the handler should free any storage it's holding.
7332 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c, char *type,
7333 cchandler_fn_t handler, void *ctx)
7335 struct Packet *pktout;
7337 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7338 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7339 ssh2_pkt_adduint32(pktout, c->remoteid);
7340 ssh2_pkt_addstring(pktout, type);
7341 ssh2_pkt_addbool(pktout, handler != NULL);
7342 if (handler != NULL)
7343 ssh2_queue_chanreq_handler(c, handler, ctx);
7348 * Potentially enlarge the window on an SSH-2 channel.
7350 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
7352 static void ssh2_set_window(struct ssh_channel *c, int newwin)
7357 * Never send WINDOW_ADJUST for a channel that the remote side has
7358 * already sent EOF on; there's no point, since it won't be
7359 * sending any more data anyway. Ditto if _we've_ already sent
7362 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
7366 * Also, never widen the window for an X11 channel when we're
7367 * still waiting to see its initial auth and may yet hand it off
7370 if (c->type == CHAN_X11 && c->u.x11.initial)
7374 * If the remote end has a habit of ignoring maxpkt, limit the
7375 * window so that it has no choice (assuming it doesn't ignore the
7378 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
7379 newwin = OUR_V2_MAXPKT;
7382 * Only send a WINDOW_ADJUST if there's significantly more window
7383 * available than the other end thinks there is. This saves us
7384 * sending a WINDOW_ADJUST for every character in a shell session.
7386 * "Significant" is arbitrarily defined as half the window size.
7388 if (newwin / 2 >= c->v.v2.locwindow) {
7389 struct Packet *pktout;
7393 * In order to keep track of how much window the client
7394 * actually has available, we'd like it to acknowledge each
7395 * WINDOW_ADJUST. We can't do that directly, so we accompany
7396 * it with a CHANNEL_REQUEST that has to be acknowledged.
7398 * This is only necessary if we're opening the window wide.
7399 * If we're not, then throughput is being constrained by
7400 * something other than the maximum window size anyway.
7402 if (newwin == c->v.v2.locmaxwin &&
7403 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
7404 up = snew(unsigned);
7405 *up = newwin - c->v.v2.locwindow;
7406 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
7407 ssh2_handle_winadj_response, up);
7408 ssh2_pkt_send(ssh, pktout);
7410 if (c->v.v2.throttle_state != UNTHROTTLED)
7411 c->v.v2.throttle_state = UNTHROTTLING;
7413 /* Pretend the WINDOW_ADJUST was acked immediately. */
7414 c->v.v2.remlocwin = newwin;
7415 c->v.v2.throttle_state = THROTTLED;
7417 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7418 ssh2_pkt_adduint32(pktout, c->remoteid);
7419 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
7420 ssh2_pkt_send(ssh, pktout);
7421 c->v.v2.locwindow = newwin;
7426 * Find the channel associated with a message. If there's no channel,
7427 * or it's not properly open, make a noise about it and return NULL.
7429 static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
7431 unsigned localid = ssh_pkt_getuint32(pktin);
7432 struct ssh_channel *c;
7434 c = find234(ssh->channels, &localid, ssh_channelfind);
7436 (c->type != CHAN_SHARING && c->halfopen &&
7437 pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
7438 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
7439 char *buf = dupprintf("Received %s for %s channel %u",
7440 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
7442 c ? "half-open" : "nonexistent", localid);
7443 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
7450 static void ssh2_handle_winadj_response(struct ssh_channel *c,
7451 struct Packet *pktin, void *ctx)
7453 unsigned *sizep = ctx;
7456 * Winadj responses should always be failures. However, at least
7457 * one server ("boks_sshd") is known to return SUCCESS for channel
7458 * requests it's never heard of, such as "winadj@putty". Raised
7459 * with foxt.com as bug 090916-090424, but for the sake of a quiet
7460 * life, we don't worry about what kind of response we got.
7463 c->v.v2.remlocwin += *sizep;
7466 * winadj messages are only sent when the window is fully open, so
7467 * if we get an ack of one, we know any pending unthrottle is
7470 if (c->v.v2.throttle_state == UNTHROTTLING)
7471 c->v.v2.throttle_state = UNTHROTTLED;
7474 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
7476 struct ssh_channel *c = ssh2_channel_msg(ssh, pktin);
7477 struct outstanding_channel_request *ocr;
7480 if (c->type == CHAN_SHARING) {
7481 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7482 pktin->body, pktin->length);
7485 ocr = c->v.v2.chanreq_head;
7487 ssh2_msg_unexpected(ssh, pktin);
7490 ocr->handler(c, pktin, ocr->ctx);
7491 c->v.v2.chanreq_head = ocr->next;
7494 * We may now initiate channel-closing procedures, if that
7495 * CHANNEL_REQUEST was the last thing outstanding before we send
7498 ssh2_channel_check_close(c);
7501 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
7503 struct ssh_channel *c;
7504 c = ssh2_channel_msg(ssh, pktin);
7507 if (c->type == CHAN_SHARING) {
7508 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7509 pktin->body, pktin->length);
7512 if (!(c->closes & CLOSES_SENT_EOF)) {
7513 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
7514 ssh2_try_send_and_unthrottle(ssh, c);
7518 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
7522 struct ssh_channel *c;
7523 c = ssh2_channel_msg(ssh, pktin);
7526 if (c->type == CHAN_SHARING) {
7527 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7528 pktin->body, pktin->length);
7531 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
7532 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
7533 return; /* extended but not stderr */
7534 ssh_pkt_getstring(pktin, &data, &length);
7537 c->v.v2.locwindow -= length;
7538 c->v.v2.remlocwin -= length;
7540 case CHAN_MAINSESSION:
7542 from_backend(ssh->frontend, pktin->type ==
7543 SSH2_MSG_CHANNEL_EXTENDED_DATA,
7547 bufsize = x11_send(c->u.x11.xconn, data, length);
7550 bufsize = pfd_send(c->u.pfd.pf, data, length);
7553 while (length > 0) {
7554 if (c->u.a.lensofar < 4) {
7555 unsigned int l = min(4 - c->u.a.lensofar,
7557 memcpy(c->u.a.msglen + c->u.a.lensofar,
7561 c->u.a.lensofar += l;
7563 if (c->u.a.lensofar == 4) {
7565 4 + GET_32BIT(c->u.a.msglen);
7566 c->u.a.message = snewn(c->u.a.totallen,
7568 memcpy(c->u.a.message, c->u.a.msglen, 4);
7570 if (c->u.a.lensofar >= 4 && length > 0) {
7572 min(c->u.a.totallen - c->u.a.lensofar,
7574 memcpy(c->u.a.message + c->u.a.lensofar,
7578 c->u.a.lensofar += l;
7580 if (c->u.a.lensofar == c->u.a.totallen) {
7583 c->u.a.outstanding_requests++;
7584 if (agent_query(c->u.a.message,
7587 ssh_agentf_callback, c))
7588 ssh_agentf_callback(c, reply, replylen);
7589 sfree(c->u.a.message);
7590 c->u.a.message = NULL;
7591 c->u.a.lensofar = 0;
7598 * If it looks like the remote end hit the end of its window,
7599 * and we didn't want it to do that, think about using a
7602 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
7603 c->v.v2.locmaxwin < 0x40000000)
7604 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
7606 * If we are not buffering too much data,
7607 * enlarge the window again at the remote side.
7608 * If we are buffering too much, we may still
7609 * need to adjust the window if the server's
7612 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
7613 c->v.v2.locmaxwin - bufsize : 0);
7615 * If we're either buffering way too much data, or if we're
7616 * buffering anything at all and we're in "simple" mode,
7617 * throttle the whole channel.
7619 if ((bufsize > c->v.v2.locmaxwin || (ssh_is_simple(ssh) && bufsize>0))
7620 && !c->throttling_conn) {
7621 c->throttling_conn = 1;
7622 ssh_throttle_conn(ssh, +1);
7627 static void ssh_check_termination(Ssh ssh)
7629 if (ssh->version == 2 &&
7630 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
7631 count234(ssh->channels) == 0 &&
7632 !(ssh->connshare && share_ndownstreams(ssh->connshare) > 0)) {
7634 * We used to send SSH_MSG_DISCONNECT here, because I'd
7635 * believed that _every_ conforming SSH-2 connection had to
7636 * end with a disconnect being sent by at least one side;
7637 * apparently I was wrong and it's perfectly OK to
7638 * unceremoniously slam the connection shut when you're done,
7639 * and indeed OpenSSH feels this is more polite than sending a
7640 * DISCONNECT. So now we don't.
7642 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
7646 void ssh_sharing_downstream_connected(Ssh ssh, unsigned id)
7648 logeventf(ssh, "Connection sharing downstream #%u connected", id);
7651 void ssh_sharing_downstream_disconnected(Ssh ssh, unsigned id)
7653 logeventf(ssh, "Connection sharing downstream #%u disconnected", id);
7654 ssh_check_termination(ssh);
7657 void ssh_sharing_logf(Ssh ssh, unsigned id, const char *logfmt, ...)
7662 va_start(ap, logfmt);
7663 buf = dupvprintf(logfmt, ap);
7666 logeventf(ssh, "Connection sharing downstream #%u: %s", id, buf);
7668 logeventf(ssh, "Connection sharing: %s", buf);
7672 static void ssh_channel_destroy(struct ssh_channel *c)
7677 case CHAN_MAINSESSION:
7678 ssh->mainchan = NULL;
7679 update_specials_menu(ssh->frontend);
7682 if (c->u.x11.xconn != NULL)
7683 x11_close(c->u.x11.xconn);
7684 logevent("Forwarded X11 connection terminated");
7687 sfree(c->u.a.message);
7690 if (c->u.pfd.pf != NULL)
7691 pfd_close(c->u.pfd.pf);
7692 logevent("Forwarded port closed");
7696 del234(ssh->channels, c);
7697 if (ssh->version == 2) {
7698 bufchain_clear(&c->v.v2.outbuffer);
7699 assert(c->v.v2.chanreq_head == NULL);
7704 * If that was the last channel left open, we might need to
7707 ssh_check_termination(ssh);
7710 static void ssh2_channel_check_close(struct ssh_channel *c)
7713 struct Packet *pktout;
7717 * If we've sent out our own CHANNEL_OPEN but not yet seen
7718 * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
7719 * it's too early to be sending close messages of any kind.
7724 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
7725 c->type == CHAN_ZOMBIE) &&
7726 !c->v.v2.chanreq_head &&
7727 !(c->closes & CLOSES_SENT_CLOSE)) {
7729 * We have both sent and received EOF (or the channel is a
7730 * zombie), and we have no outstanding channel requests, which
7731 * means the channel is in final wind-up. But we haven't sent
7732 * CLOSE, so let's do so now.
7734 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
7735 ssh2_pkt_adduint32(pktout, c->remoteid);
7736 ssh2_pkt_send(ssh, pktout);
7737 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
7740 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
7741 assert(c->v.v2.chanreq_head == NULL);
7743 * We have both sent and received CLOSE, which means we're
7744 * completely done with the channel.
7746 ssh_channel_destroy(c);
7750 static void ssh2_channel_got_eof(struct ssh_channel *c)
7752 if (c->closes & CLOSES_RCVD_EOF)
7753 return; /* already seen EOF */
7754 c->closes |= CLOSES_RCVD_EOF;
7756 if (c->type == CHAN_X11) {
7757 x11_send_eof(c->u.x11.xconn);
7758 } else if (c->type == CHAN_AGENT) {
7759 if (c->u.a.outstanding_requests == 0) {
7760 /* Manufacture an outgoing EOF in response to the incoming one. */
7761 sshfwd_write_eof(c);
7763 } else if (c->type == CHAN_SOCKDATA) {
7764 pfd_send_eof(c->u.pfd.pf);
7765 } else if (c->type == CHAN_MAINSESSION) {
7768 if (!ssh->sent_console_eof &&
7769 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
7771 * Either from_backend_eof told us that the front end
7772 * wants us to close the outgoing side of the connection
7773 * as soon as we see EOF from the far end, or else we've
7774 * unilaterally decided to do that because we've allocated
7775 * a remote pty and hence EOF isn't a particularly
7776 * meaningful concept.
7778 sshfwd_write_eof(c);
7780 ssh->sent_console_eof = TRUE;
7783 ssh2_channel_check_close(c);
7786 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
7788 struct ssh_channel *c;
7790 c = ssh2_channel_msg(ssh, pktin);
7793 if (c->type == CHAN_SHARING) {
7794 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7795 pktin->body, pktin->length);
7798 ssh2_channel_got_eof(c);
7801 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
7803 struct ssh_channel *c;
7805 c = ssh2_channel_msg(ssh, pktin);
7808 if (c->type == CHAN_SHARING) {
7809 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7810 pktin->body, pktin->length);
7815 * When we receive CLOSE on a channel, we assume it comes with an
7816 * implied EOF if we haven't seen EOF yet.
7818 ssh2_channel_got_eof(c);
7820 if (!(ssh->remote_bugs & BUG_SENDS_LATE_REQUEST_REPLY)) {
7822 * It also means we stop expecting to see replies to any
7823 * outstanding channel requests, so clean those up too.
7824 * (ssh_chanreq_init will enforce by assertion that we don't
7825 * subsequently put anything back on this list.)
7827 while (c->v.v2.chanreq_head) {
7828 struct outstanding_channel_request *ocr = c->v.v2.chanreq_head;
7829 ocr->handler(c, NULL, ocr->ctx);
7830 c->v.v2.chanreq_head = ocr->next;
7836 * And we also send an outgoing EOF, if we haven't already, on the
7837 * assumption that CLOSE is a pretty forceful announcement that
7838 * the remote side is doing away with the entire channel. (If it
7839 * had wanted to send us EOF and continue receiving data from us,
7840 * it would have just sent CHANNEL_EOF.)
7842 if (!(c->closes & CLOSES_SENT_EOF)) {
7844 * Make sure we don't read any more from whatever our local
7845 * data source is for this channel.
7848 case CHAN_MAINSESSION:
7849 ssh->send_ok = 0; /* stop trying to read from stdin */
7852 x11_override_throttle(c->u.x11.xconn, 1);
7855 pfd_override_throttle(c->u.pfd.pf, 1);
7860 * Abandon any buffered data we still wanted to send to this
7861 * channel. Receiving a CHANNEL_CLOSE is an indication that
7862 * the server really wants to get on and _destroy_ this
7863 * channel, and it isn't going to send us any further
7864 * WINDOW_ADJUSTs to permit us to send pending stuff.
7866 bufchain_clear(&c->v.v2.outbuffer);
7869 * Send outgoing EOF.
7871 sshfwd_write_eof(c);
7875 * Now process the actual close.
7877 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
7878 c->closes |= CLOSES_RCVD_CLOSE;
7879 ssh2_channel_check_close(c);
7883 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
7885 struct ssh_channel *c;
7887 c = ssh2_channel_msg(ssh, pktin);
7890 if (c->type == CHAN_SHARING) {
7891 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7892 pktin->body, pktin->length);
7895 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7896 c->remoteid = ssh_pkt_getuint32(pktin);
7897 c->halfopen = FALSE;
7898 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7899 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7901 if (c->type == CHAN_SOCKDATA_DORMANT) {
7902 c->type = CHAN_SOCKDATA;
7904 pfd_confirm(c->u.pfd.pf);
7905 } else if (c->type == CHAN_ZOMBIE) {
7907 * This case can occur if a local socket error occurred
7908 * between us sending out CHANNEL_OPEN and receiving
7909 * OPEN_CONFIRMATION. In this case, all we can do is
7910 * immediately initiate close proceedings now that we know the
7911 * server's id to put in the close message.
7913 ssh2_channel_check_close(c);
7916 * We never expect to receive OPEN_CONFIRMATION for any
7917 * *other* channel type (since only local-to-remote port
7918 * forwardings cause us to send CHANNEL_OPEN after the main
7919 * channel is live - all other auxiliary channel types are
7920 * initiated from the server end). It's safe to enforce this
7921 * by assertion rather than by ssh_disconnect, because the
7922 * real point is that we never constructed a half-open channel
7923 * structure in the first place with any type other than the
7926 assert(!"Funny channel type in ssh2_msg_channel_open_confirmation");
7930 ssh_channel_try_eof(c); /* in case we had a pending EOF */
7933 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
7935 static const char *const reasons[] = {
7936 "<unknown reason code>",
7937 "Administratively prohibited",
7939 "Unknown channel type",
7940 "Resource shortage",
7942 unsigned reason_code;
7943 char *reason_string;
7945 struct ssh_channel *c;
7947 c = ssh2_channel_msg(ssh, pktin);
7950 if (c->type == CHAN_SHARING) {
7951 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7952 pktin->body, pktin->length);
7955 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7957 if (c->type == CHAN_SOCKDATA_DORMANT) {
7958 reason_code = ssh_pkt_getuint32(pktin);
7959 if (reason_code >= lenof(reasons))
7960 reason_code = 0; /* ensure reasons[reason_code] in range */
7961 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
7962 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
7963 reasons[reason_code], reason_length, reason_string);
7965 pfd_close(c->u.pfd.pf);
7966 } else if (c->type == CHAN_ZOMBIE) {
7968 * This case can occur if a local socket error occurred
7969 * between us sending out CHANNEL_OPEN and receiving
7970 * OPEN_FAILURE. In this case, we need do nothing except allow
7971 * the code below to throw the half-open channel away.
7975 * We never expect to receive OPEN_FAILURE for any *other*
7976 * channel type (since only local-to-remote port forwardings
7977 * cause us to send CHANNEL_OPEN after the main channel is
7978 * live - all other auxiliary channel types are initiated from
7979 * the server end). It's safe to enforce this by assertion
7980 * rather than by ssh_disconnect, because the real point is
7981 * that we never constructed a half-open channel structure in
7982 * the first place with any type other than the above.
7984 assert(!"Funny channel type in ssh2_msg_channel_open_failure");
7987 del234(ssh->channels, c);
7991 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
7994 int typelen, want_reply;
7995 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
7996 struct ssh_channel *c;
7997 struct Packet *pktout;
7999 c = ssh2_channel_msg(ssh, pktin);
8002 if (c->type == CHAN_SHARING) {
8003 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8004 pktin->body, pktin->length);
8007 ssh_pkt_getstring(pktin, &type, &typelen);
8008 want_reply = ssh2_pkt_getbool(pktin);
8010 if (c->closes & CLOSES_SENT_CLOSE) {
8012 * We don't reply to channel requests after we've sent
8013 * CHANNEL_CLOSE for the channel, because our reply might
8014 * cross in the network with the other side's CHANNEL_CLOSE
8015 * and arrive after they have wound the channel up completely.
8021 * Having got the channel number, we now look at
8022 * the request type string to see if it's something
8025 if (c == ssh->mainchan) {
8027 * We recognise "exit-status" and "exit-signal" on
8028 * the primary channel.
8030 if (typelen == 11 &&
8031 !memcmp(type, "exit-status", 11)) {
8033 ssh->exitcode = ssh_pkt_getuint32(pktin);
8034 logeventf(ssh, "Server sent command exit status %d",
8036 reply = SSH2_MSG_CHANNEL_SUCCESS;
8038 } else if (typelen == 11 &&
8039 !memcmp(type, "exit-signal", 11)) {
8041 int is_plausible = TRUE, is_int = FALSE;
8042 char *fmt_sig = "", *fmt_msg = "";
8044 int msglen = 0, core = FALSE;
8045 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
8046 * provide an `int' for the signal, despite its
8047 * having been a `string' in the drafts of RFC 4254 since at
8048 * least 2001. (Fixed in session.c 1.147.) Try to
8049 * infer which we can safely parse it as. */
8051 unsigned char *p = pktin->body +
8053 long len = pktin->length - pktin->savedpos;
8054 unsigned long num = GET_32BIT(p); /* what is it? */
8055 /* If it's 0, it hardly matters; assume string */
8059 int maybe_int = FALSE, maybe_str = FALSE;
8060 #define CHECK_HYPOTHESIS(offset, result) \
8063 int q = toint(offset); \
8064 if (q >= 0 && q+4 <= len) { \
8065 q = toint(q + 4 + GET_32BIT(p+q)); \
8066 if (q >= 0 && q+4 <= len && \
8067 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
8072 CHECK_HYPOTHESIS(4+1, maybe_int);
8073 CHECK_HYPOTHESIS(4+num+1, maybe_str);
8074 #undef CHECK_HYPOTHESIS
8075 if (maybe_int && !maybe_str)
8077 else if (!maybe_int && maybe_str)
8080 /* Crikey. Either or neither. Panic. */
8081 is_plausible = FALSE;
8084 ssh->exitcode = 128; /* means `unknown signal' */
8087 /* Old non-standard OpenSSH. */
8088 int signum = ssh_pkt_getuint32(pktin);
8089 fmt_sig = dupprintf(" %d", signum);
8090 ssh->exitcode = 128 + signum;
8092 /* As per RFC 4254. */
8095 ssh_pkt_getstring(pktin, &sig, &siglen);
8096 /* Signal name isn't supposed to be blank, but
8097 * let's cope gracefully if it is. */
8099 fmt_sig = dupprintf(" \"%.*s\"",
8104 * Really hideous method of translating the
8105 * signal description back into a locally
8106 * meaningful number.
8111 #define TRANSLATE_SIGNAL(s) \
8112 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
8113 ssh->exitcode = 128 + SIG ## s
8115 TRANSLATE_SIGNAL(ABRT);
8118 TRANSLATE_SIGNAL(ALRM);
8121 TRANSLATE_SIGNAL(FPE);
8124 TRANSLATE_SIGNAL(HUP);
8127 TRANSLATE_SIGNAL(ILL);
8130 TRANSLATE_SIGNAL(INT);
8133 TRANSLATE_SIGNAL(KILL);
8136 TRANSLATE_SIGNAL(PIPE);
8139 TRANSLATE_SIGNAL(QUIT);
8142 TRANSLATE_SIGNAL(SEGV);
8145 TRANSLATE_SIGNAL(TERM);
8148 TRANSLATE_SIGNAL(USR1);
8151 TRANSLATE_SIGNAL(USR2);
8153 #undef TRANSLATE_SIGNAL
8155 ssh->exitcode = 128;
8157 core = ssh2_pkt_getbool(pktin);
8158 ssh_pkt_getstring(pktin, &msg, &msglen);
8160 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
8162 /* ignore lang tag */
8163 } /* else don't attempt to parse */
8164 logeventf(ssh, "Server exited on signal%s%s%s",
8165 fmt_sig, core ? " (core dumped)" : "",
8167 if (*fmt_sig) sfree(fmt_sig);
8168 if (*fmt_msg) sfree(fmt_msg);
8169 reply = SSH2_MSG_CHANNEL_SUCCESS;
8174 * This is a channel request we don't know
8175 * about, so we now either ignore the request
8176 * or respond with CHANNEL_FAILURE, depending
8179 reply = SSH2_MSG_CHANNEL_FAILURE;
8182 pktout = ssh2_pkt_init(reply);
8183 ssh2_pkt_adduint32(pktout, c->remoteid);
8184 ssh2_pkt_send(ssh, pktout);
8188 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
8191 int typelen, want_reply;
8192 struct Packet *pktout;
8194 ssh_pkt_getstring(pktin, &type, &typelen);
8195 want_reply = ssh2_pkt_getbool(pktin);
8198 * We currently don't support any global requests
8199 * at all, so we either ignore the request or
8200 * respond with REQUEST_FAILURE, depending on
8204 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
8205 ssh2_pkt_send(ssh, pktout);
8209 struct X11FakeAuth *ssh_sharing_add_x11_display(Ssh ssh, int authtype,
8213 struct X11FakeAuth *auth;
8216 * Make up a new set of fake X11 auth data, and add it to the tree
8217 * of currently valid ones with an indication of the sharing
8218 * context that it's relevant to.
8220 auth = x11_invent_fake_auth(ssh->x11authtree, authtype);
8221 auth->share_cs = share_cs;
8222 auth->share_chan = share_chan;
8227 void ssh_sharing_remove_x11_display(Ssh ssh, struct X11FakeAuth *auth)
8229 del234(ssh->x11authtree, auth);
8230 x11_free_fake_auth(auth);
8233 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
8241 struct ssh_channel *c;
8242 unsigned remid, winsize, pktsize;
8243 unsigned our_winsize_override = 0;
8244 struct Packet *pktout;
8246 ssh_pkt_getstring(pktin, &type, &typelen);
8247 c = snew(struct ssh_channel);
8250 remid = ssh_pkt_getuint32(pktin);
8251 winsize = ssh_pkt_getuint32(pktin);
8252 pktsize = ssh_pkt_getuint32(pktin);
8254 if (typelen == 3 && !memcmp(type, "x11", 3)) {
8257 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8258 addrstr = snewn(peeraddrlen+1, char);
8259 memcpy(addrstr, peeraddr, peeraddrlen);
8260 addrstr[peeraddrlen] = '\0';
8261 peerport = ssh_pkt_getuint32(pktin);
8263 logeventf(ssh, "Received X11 connect request from %s:%d",
8266 if (!ssh->X11_fwd_enabled && !ssh->connshare)
8267 error = "X11 forwarding is not enabled";
8269 c->u.x11.xconn = x11_init(ssh->x11authtree, c,
8272 c->u.x11.initial = TRUE;
8275 * If we are a connection-sharing upstream, then we should
8276 * initially present a very small window, adequate to take
8277 * the X11 initial authorisation packet but not much more.
8278 * Downstream will then present us a larger window (by
8279 * fiat of the connection-sharing protocol) and we can
8280 * guarantee to send a positive-valued WINDOW_ADJUST.
8283 our_winsize_override = 128;
8285 logevent("Opened X11 forward channel");
8289 } else if (typelen == 15 &&
8290 !memcmp(type, "forwarded-tcpip", 15)) {
8291 struct ssh_rportfwd pf, *realpf;
8294 ssh_pkt_getstring(pktin, &shost, &shostlen);/* skip address */
8295 pf.shost = dupprintf("%.*s", shostlen, shost);
8296 pf.sport = ssh_pkt_getuint32(pktin);
8297 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8298 peerport = ssh_pkt_getuint32(pktin);
8299 realpf = find234(ssh->rportfwds, &pf, NULL);
8300 logeventf(ssh, "Received remote port %s:%d open request "
8301 "from %s:%d", pf.shost, pf.sport, peeraddr, peerport);
8304 if (realpf == NULL) {
8305 error = "Remote port is not recognised";
8309 if (realpf->share_ctx) {
8311 * This port forwarding is on behalf of a
8312 * connection-sharing downstream, so abandon our own
8313 * channel-open procedure and just pass the message on
8316 share_got_pkt_from_server(realpf->share_ctx, pktin->type,
8317 pktin->body, pktin->length);
8322 err = pfd_connect(&c->u.pfd.pf, realpf->dhost, realpf->dport,
8323 c, ssh->conf, realpf->pfrec->addressfamily);
8324 logeventf(ssh, "Attempting to forward remote port to "
8325 "%s:%d", realpf->dhost, realpf->dport);
8327 logeventf(ssh, "Port open failed: %s", err);
8329 error = "Port open failed";
8331 logevent("Forwarded port opened successfully");
8332 c->type = CHAN_SOCKDATA;
8335 } else if (typelen == 22 &&
8336 !memcmp(type, "auth-agent@openssh.com", 22)) {
8337 if (!ssh->agentfwd_enabled)
8338 error = "Agent forwarding is not enabled";
8340 c->type = CHAN_AGENT; /* identify channel type */
8341 c->u.a.lensofar = 0;
8342 c->u.a.message = NULL;
8343 c->u.a.outstanding_requests = 0;
8346 error = "Unsupported channel type requested";
8349 c->remoteid = remid;
8350 c->halfopen = FALSE;
8352 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
8353 ssh2_pkt_adduint32(pktout, c->remoteid);
8354 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
8355 ssh2_pkt_addstring(pktout, error);
8356 ssh2_pkt_addstring(pktout, "en"); /* language tag */
8357 ssh2_pkt_send(ssh, pktout);
8358 logeventf(ssh, "Rejected channel open: %s", error);
8361 ssh2_channel_init(c);
8362 c->v.v2.remwindow = winsize;
8363 c->v.v2.remmaxpkt = pktsize;
8364 if (our_winsize_override) {
8365 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
8366 our_winsize_override;
8368 add234(ssh->channels, c);
8369 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
8370 ssh2_pkt_adduint32(pktout, c->remoteid);
8371 ssh2_pkt_adduint32(pktout, c->localid);
8372 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
8373 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8374 ssh2_pkt_send(ssh, pktout);
8378 void sshfwd_x11_sharing_handover(struct ssh_channel *c,
8379 void *share_cs, void *share_chan,
8380 const char *peer_addr, int peer_port,
8381 int endian, int protomajor, int protominor,
8382 const void *initial_data, int initial_len)
8385 * This function is called when we've just discovered that an X
8386 * forwarding channel on which we'd been handling the initial auth
8387 * ourselves turns out to be destined for a connection-sharing
8388 * downstream. So we turn the channel into a CHAN_SHARING, meaning
8389 * that we completely stop tracking windows and buffering data and
8390 * just pass more or less unmodified SSH messages back and forth.
8392 c->type = CHAN_SHARING;
8393 c->u.sharing.ctx = share_cs;
8394 share_setup_x11_channel(share_cs, share_chan,
8395 c->localid, c->remoteid, c->v.v2.remwindow,
8396 c->v.v2.remmaxpkt, c->v.v2.locwindow,
8397 peer_addr, peer_port, endian,
8398 protomajor, protominor,
8399 initial_data, initial_len);
8402 void sshfwd_x11_is_local(struct ssh_channel *c)
8405 * This function is called when we've just discovered that an X
8406 * forwarding channel is _not_ destined for a connection-sharing
8407 * downstream but we're going to handle it ourselves. We stop
8408 * presenting a cautiously small window and go into ordinary data
8411 c->u.x11.initial = FALSE;
8412 ssh2_set_window(c, ssh_is_simple(c->ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE);
8416 * Buffer banner messages for later display at some convenient point,
8417 * if we're going to display them.
8419 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
8421 /* Arbitrary limit to prevent unbounded inflation of buffer */
8422 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
8423 bufchain_size(&ssh->banner) <= 131072) {
8424 char *banner = NULL;
8426 ssh_pkt_getstring(pktin, &banner, &size);
8428 bufchain_add(&ssh->banner, banner, size);
8432 /* Helper function to deal with sending tty modes for "pty-req" */
8433 static void ssh2_send_ttymode(void *data, char *mode, char *val)
8435 struct Packet *pktout = (struct Packet *)data;
8437 unsigned int arg = 0;
8438 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
8439 if (i == lenof(ssh_ttymodes)) return;
8440 switch (ssh_ttymodes[i].type) {
8442 arg = ssh_tty_parse_specchar(val);
8445 arg = ssh_tty_parse_boolean(val);
8448 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
8449 ssh2_pkt_adduint32(pktout, arg);
8452 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
8455 struct ssh2_setup_x11_state {
8459 struct Packet *pktout;
8460 crStateP(ssh2_setup_x11_state, ctx);
8464 logevent("Requesting X11 forwarding");
8465 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
8467 ssh2_pkt_addbool(pktout, 0); /* many connections */
8468 ssh2_pkt_addstring(pktout, ssh->x11auth->protoname);
8469 ssh2_pkt_addstring(pktout, ssh->x11auth->datastring);
8470 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
8471 ssh2_pkt_send(ssh, pktout);
8473 /* Wait to be called back with either a response packet, or NULL
8474 * meaning clean up and free our data */
8478 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8479 logevent("X11 forwarding enabled");
8480 ssh->X11_fwd_enabled = TRUE;
8482 logevent("X11 forwarding refused");
8488 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
8491 struct ssh2_setup_agent_state {
8495 struct Packet *pktout;
8496 crStateP(ssh2_setup_agent_state, ctx);
8500 logevent("Requesting OpenSSH-style agent forwarding");
8501 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
8502 ssh2_setup_agent, s);
8503 ssh2_pkt_send(ssh, pktout);
8505 /* Wait to be called back with either a response packet, or NULL
8506 * meaning clean up and free our data */
8510 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8511 logevent("Agent forwarding enabled");
8512 ssh->agentfwd_enabled = TRUE;
8514 logevent("Agent forwarding refused");
8520 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
8523 struct ssh2_setup_pty_state {
8527 struct Packet *pktout;
8528 crStateP(ssh2_setup_pty_state, ctx);
8532 /* Unpick the terminal-speed string. */
8533 /* XXX perhaps we should allow no speeds to be sent. */
8534 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
8535 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
8536 /* Build the pty request. */
8537 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
8539 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
8540 ssh2_pkt_adduint32(pktout, ssh->term_width);
8541 ssh2_pkt_adduint32(pktout, ssh->term_height);
8542 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
8543 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
8544 ssh2_pkt_addstring_start(pktout);
8545 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
8546 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
8547 ssh2_pkt_adduint32(pktout, ssh->ispeed);
8548 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
8549 ssh2_pkt_adduint32(pktout, ssh->ospeed);
8550 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
8551 ssh2_pkt_send(ssh, pktout);
8552 ssh->state = SSH_STATE_INTERMED;
8554 /* Wait to be called back with either a response packet, or NULL
8555 * meaning clean up and free our data */
8559 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8560 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
8561 ssh->ospeed, ssh->ispeed);
8562 ssh->got_pty = TRUE;
8564 c_write_str(ssh, "Server refused to allocate pty\r\n");
8565 ssh->editing = ssh->echoing = 1;
8572 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
8575 struct ssh2_setup_env_state {
8577 int num_env, env_left, env_ok;
8580 struct Packet *pktout;
8581 crStateP(ssh2_setup_env_state, ctx);
8586 * Send environment variables.
8588 * Simplest thing here is to send all the requests at once, and
8589 * then wait for a whole bunch of successes or failures.
8595 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
8597 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
8598 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
8599 ssh2_pkt_addstring(pktout, key);
8600 ssh2_pkt_addstring(pktout, val);
8601 ssh2_pkt_send(ssh, pktout);
8606 logeventf(ssh, "Sent %d environment variables", s->num_env);
8611 s->env_left = s->num_env;
8613 while (s->env_left > 0) {
8614 /* Wait to be called back with either a response packet,
8615 * or NULL meaning clean up and free our data */
8617 if (!pktin) goto out;
8618 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
8623 if (s->env_ok == s->num_env) {
8624 logevent("All environment variables successfully set");
8625 } else if (s->env_ok == 0) {
8626 logevent("All environment variables refused");
8627 c_write_str(ssh, "Server refused to set environment variables\r\n");
8629 logeventf(ssh, "%d environment variables refused",
8630 s->num_env - s->env_ok);
8631 c_write_str(ssh, "Server refused to set all environment variables\r\n");
8639 * Handle the SSH-2 userauth and connection layers.
8641 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
8643 do_ssh2_authconn(ssh, NULL, 0, pktin);
8646 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
8650 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
8653 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
8654 struct Packet *pktin)
8656 struct do_ssh2_authconn_state {
8660 AUTH_TYPE_PUBLICKEY,
8661 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
8662 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
8664 AUTH_TYPE_GSSAPI, /* always QUIET */
8665 AUTH_TYPE_KEYBOARD_INTERACTIVE,
8666 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
8668 int done_service_req;
8669 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
8670 int tried_pubkey_config, done_agent;
8675 int kbd_inter_refused;
8676 int we_are_in, userauth_success;
8677 prompts_t *cur_prompt;
8682 void *publickey_blob;
8683 int publickey_bloblen;
8684 int publickey_encrypted;
8685 char *publickey_algorithm;
8686 char *publickey_comment;
8687 unsigned char agent_request[5], *agent_response, *agentp;
8688 int agent_responselen;
8689 unsigned char *pkblob_in_agent;
8691 char *pkblob, *alg, *commentp;
8692 int pklen, alglen, commentlen;
8693 int siglen, retlen, len;
8694 char *q, *agentreq, *ret;
8696 struct Packet *pktout;
8699 struct ssh_gss_library *gsslib;
8700 Ssh_gss_ctx gss_ctx;
8701 Ssh_gss_buf gss_buf;
8702 Ssh_gss_buf gss_rcvtok, gss_sndtok;
8703 Ssh_gss_name gss_srv_name;
8704 Ssh_gss_stat gss_stat;
8707 crState(do_ssh2_authconn_state);
8711 /* Register as a handler for all the messages this coroutine handles. */
8712 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
8713 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
8714 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
8715 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
8716 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
8717 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
8718 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
8719 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
8720 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
8721 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
8722 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
8723 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
8724 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
8725 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
8726 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
8727 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
8728 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
8729 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
8730 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
8731 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
8733 s->done_service_req = FALSE;
8734 s->we_are_in = s->userauth_success = FALSE;
8735 s->agent_response = NULL;
8737 s->tried_gssapi = FALSE;
8740 if (!ssh->bare_connection) {
8741 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
8743 * Request userauth protocol, and await a response to it.
8745 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8746 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
8747 ssh2_pkt_send(ssh, s->pktout);
8748 crWaitUntilV(pktin);
8749 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
8750 s->done_service_req = TRUE;
8752 if (!s->done_service_req) {
8754 * Request connection protocol directly, without authentication.
8756 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8757 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8758 ssh2_pkt_send(ssh, s->pktout);
8759 crWaitUntilV(pktin);
8760 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
8761 s->we_are_in = TRUE; /* no auth required */
8763 bombout(("Server refused service request"));
8768 s->we_are_in = TRUE;
8771 /* Arrange to be able to deal with any BANNERs that come in.
8772 * (We do this now as packets may come in during the next bit.) */
8773 bufchain_init(&ssh->banner);
8774 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
8775 ssh2_msg_userauth_banner;
8778 * Misc one-time setup for authentication.
8780 s->publickey_blob = NULL;
8781 if (!s->we_are_in) {
8784 * Load the public half of any configured public key file
8787 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
8788 if (!filename_is_null(s->keyfile)) {
8790 logeventf(ssh, "Reading private key file \"%.150s\"",
8791 filename_to_str(s->keyfile));
8792 keytype = key_type(s->keyfile);
8793 if (keytype == SSH_KEYTYPE_SSH2) {
8796 ssh2_userkey_loadpub(s->keyfile,
8797 &s->publickey_algorithm,
8798 &s->publickey_bloblen,
8799 &s->publickey_comment, &error);
8800 if (s->publickey_blob) {
8801 s->publickey_encrypted =
8802 ssh2_userkey_encrypted(s->keyfile, NULL);
8805 logeventf(ssh, "Unable to load private key (%s)",
8807 msgbuf = dupprintf("Unable to load private key file "
8808 "\"%.150s\" (%s)\r\n",
8809 filename_to_str(s->keyfile),
8811 c_write_str(ssh, msgbuf);
8816 logeventf(ssh, "Unable to use this key file (%s)",
8817 key_type_to_str(keytype));
8818 msgbuf = dupprintf("Unable to use key file \"%.150s\""
8820 filename_to_str(s->keyfile),
8821 key_type_to_str(keytype));
8822 c_write_str(ssh, msgbuf);
8824 s->publickey_blob = NULL;
8829 * Find out about any keys Pageant has (but if there's a
8830 * public key configured, filter out all others).
8833 s->agent_response = NULL;
8834 s->pkblob_in_agent = NULL;
8835 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
8839 logevent("Pageant is running. Requesting keys.");
8841 /* Request the keys held by the agent. */
8842 PUT_32BIT(s->agent_request, 1);
8843 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
8844 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
8845 ssh_agent_callback, ssh)) {
8849 bombout(("Unexpected data from server while"
8850 " waiting for agent response"));
8853 } while (pktin || inlen > 0);
8854 r = ssh->agent_response;
8855 s->agent_responselen = ssh->agent_response_len;
8857 s->agent_response = (unsigned char *) r;
8858 if (s->agent_response && s->agent_responselen >= 5 &&
8859 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
8862 p = s->agent_response + 5;
8863 s->nkeys = toint(GET_32BIT(p));
8866 * Vet the Pageant response to ensure that the key
8867 * count and blob lengths make sense.
8870 logeventf(ssh, "Pageant response contained a negative"
8871 " key count %d", s->nkeys);
8873 goto done_agent_query;
8875 unsigned char *q = p + 4;
8876 int lenleft = s->agent_responselen - 5 - 4;
8878 for (keyi = 0; keyi < s->nkeys; keyi++) {
8879 int bloblen, commentlen;
8881 logeventf(ssh, "Pageant response was truncated");
8883 goto done_agent_query;
8885 bloblen = toint(GET_32BIT(q));
8886 if (bloblen < 0 || bloblen > lenleft) {
8887 logeventf(ssh, "Pageant response was truncated");
8889 goto done_agent_query;
8891 lenleft -= 4 + bloblen;
8893 commentlen = toint(GET_32BIT(q));
8894 if (commentlen < 0 || commentlen > lenleft) {
8895 logeventf(ssh, "Pageant response was truncated");
8897 goto done_agent_query;
8899 lenleft -= 4 + commentlen;
8900 q += 4 + commentlen;
8905 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
8906 if (s->publickey_blob) {
8907 /* See if configured key is in agent. */
8908 for (keyi = 0; keyi < s->nkeys; keyi++) {
8909 s->pklen = toint(GET_32BIT(p));
8910 if (s->pklen == s->publickey_bloblen &&
8911 !memcmp(p+4, s->publickey_blob,
8912 s->publickey_bloblen)) {
8913 logeventf(ssh, "Pageant key #%d matches "
8914 "configured key file", keyi);
8916 s->pkblob_in_agent = p;
8920 p += toint(GET_32BIT(p)) + 4; /* comment */
8922 if (!s->pkblob_in_agent) {
8923 logevent("Configured key file not in Pageant");
8928 logevent("Failed to get reply from Pageant");
8936 * We repeat this whole loop, including the username prompt,
8937 * until we manage a successful authentication. If the user
8938 * types the wrong _password_, they can be sent back to the
8939 * beginning to try another username, if this is configured on.
8940 * (If they specify a username in the config, they are never
8941 * asked, even if they do give a wrong password.)
8943 * I think this best serves the needs of
8945 * - the people who have no configuration, no keys, and just
8946 * want to try repeated (username,password) pairs until they
8947 * type both correctly
8949 * - people who have keys and configuration but occasionally
8950 * need to fall back to passwords
8952 * - people with a key held in Pageant, who might not have
8953 * logged in to a particular machine before; so they want to
8954 * type a username, and then _either_ their key will be
8955 * accepted, _or_ they will type a password. If they mistype
8956 * the username they will want to be able to get back and
8959 s->got_username = FALSE;
8960 while (!s->we_are_in) {
8964 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
8966 * We got a username last time round this loop, and
8967 * with change_username turned off we don't try to get
8970 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
8971 int ret; /* need not be kept over crReturn */
8972 s->cur_prompt = new_prompts(ssh->frontend);
8973 s->cur_prompt->to_server = TRUE;
8974 s->cur_prompt->name = dupstr("SSH login name");
8975 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
8976 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8979 crWaitUntilV(!pktin);
8980 ret = get_userpass_input(s->cur_prompt, in, inlen);
8985 * get_userpass_input() failed to get a username.
8988 free_prompts(s->cur_prompt);
8989 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
8992 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
8993 free_prompts(s->cur_prompt);
8996 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
8997 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
8998 c_write_str(ssh, stuff);
9002 s->got_username = TRUE;
9005 * Send an authentication request using method "none": (a)
9006 * just in case it succeeds, and (b) so that we know what
9007 * authentication methods we can usefully try next.
9009 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9011 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9012 ssh2_pkt_addstring(s->pktout, ssh->username);
9013 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
9014 ssh2_pkt_addstring(s->pktout, "none"); /* method */
9015 ssh2_pkt_send(ssh, s->pktout);
9016 s->type = AUTH_TYPE_NONE;
9018 s->we_are_in = FALSE;
9020 s->tried_pubkey_config = FALSE;
9021 s->kbd_inter_refused = FALSE;
9023 /* Reset agent request state. */
9024 s->done_agent = FALSE;
9025 if (s->agent_response) {
9026 if (s->pkblob_in_agent) {
9027 s->agentp = s->pkblob_in_agent;
9029 s->agentp = s->agent_response + 5 + 4;
9035 char *methods = NULL;
9039 * Wait for the result of the last authentication request.
9042 crWaitUntilV(pktin);
9044 * Now is a convenient point to spew any banner material
9045 * that we've accumulated. (This should ensure that when
9046 * we exit the auth loop, we haven't any left to deal
9050 int size = bufchain_size(&ssh->banner);
9052 * Don't show the banner if we're operating in
9053 * non-verbose non-interactive mode. (It's probably
9054 * a script, which means nobody will read the
9055 * banner _anyway_, and moreover the printing of
9056 * the banner will screw up processing on the
9057 * output of (say) plink.)
9059 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
9060 char *banner = snewn(size, char);
9061 bufchain_fetch(&ssh->banner, banner, size);
9062 c_write_untrusted(ssh, banner, size);
9065 bufchain_clear(&ssh->banner);
9067 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
9068 logevent("Access granted");
9069 s->we_are_in = s->userauth_success = TRUE;
9073 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
9074 bombout(("Strange packet received during authentication: "
9075 "type %d", pktin->type));
9082 * OK, we're now sitting on a USERAUTH_FAILURE message, so
9083 * we can look at the string in it and know what we can
9084 * helpfully try next.
9086 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
9087 ssh_pkt_getstring(pktin, &methods, &methlen);
9088 if (!ssh2_pkt_getbool(pktin)) {
9090 * We have received an unequivocal Access
9091 * Denied. This can translate to a variety of
9092 * messages, or no message at all.
9094 * For forms of authentication which are attempted
9095 * implicitly, by which I mean without printing
9096 * anything in the window indicating that we're
9097 * trying them, we should never print 'Access
9100 * If we do print a message saying that we're
9101 * attempting some kind of authentication, it's OK
9102 * to print a followup message saying it failed -
9103 * but the message may sometimes be more specific
9104 * than simply 'Access denied'.
9106 * Additionally, if we'd just tried password
9107 * authentication, we should break out of this
9108 * whole loop so as to go back to the username
9109 * prompt (iff we're configured to allow
9110 * username change attempts).
9112 if (s->type == AUTH_TYPE_NONE) {
9114 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
9115 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
9116 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
9117 c_write_str(ssh, "Server refused our key\r\n");
9118 logevent("Server refused our key");
9119 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
9120 /* This _shouldn't_ happen except by a
9121 * protocol bug causing client and server to
9122 * disagree on what is a correct signature. */
9123 c_write_str(ssh, "Server refused public-key signature"
9124 " despite accepting key!\r\n");
9125 logevent("Server refused public-key signature"
9126 " despite accepting key!");
9127 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
9128 /* quiet, so no c_write */
9129 logevent("Server refused keyboard-interactive authentication");
9130 } else if (s->type==AUTH_TYPE_GSSAPI) {
9131 /* always quiet, so no c_write */
9132 /* also, the code down in the GSSAPI block has
9133 * already logged this in the Event Log */
9134 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
9135 logevent("Keyboard-interactive authentication failed");
9136 c_write_str(ssh, "Access denied\r\n");
9138 assert(s->type == AUTH_TYPE_PASSWORD);
9139 logevent("Password authentication failed");
9140 c_write_str(ssh, "Access denied\r\n");
9142 if (conf_get_int(ssh->conf, CONF_change_username)) {
9143 /* XXX perhaps we should allow
9144 * keyboard-interactive to do this too? */
9145 s->we_are_in = FALSE;
9150 c_write_str(ssh, "Further authentication required\r\n");
9151 logevent("Further authentication required");
9155 in_commasep_string("publickey", methods, methlen);
9157 in_commasep_string("password", methods, methlen);
9158 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
9159 in_commasep_string("keyboard-interactive", methods, methlen);
9162 ssh->gsslibs = ssh_gss_setup(ssh->conf);
9163 s->can_gssapi = conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
9164 in_commasep_string("gssapi-with-mic", methods, methlen) &&
9165 ssh->gsslibs->nlibraries > 0;
9169 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9171 if (s->can_pubkey && !s->done_agent && s->nkeys) {
9174 * Attempt public-key authentication using a key from Pageant.
9177 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9179 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
9181 /* Unpack key from agent response */
9182 s->pklen = toint(GET_32BIT(s->agentp));
9184 s->pkblob = (char *)s->agentp;
9185 s->agentp += s->pklen;
9186 s->alglen = toint(GET_32BIT(s->pkblob));
9187 s->alg = s->pkblob + 4;
9188 s->commentlen = toint(GET_32BIT(s->agentp));
9190 s->commentp = (char *)s->agentp;
9191 s->agentp += s->commentlen;
9192 /* s->agentp now points at next key, if any */
9194 /* See if server will accept it */
9195 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9196 ssh2_pkt_addstring(s->pktout, ssh->username);
9197 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9198 /* service requested */
9199 ssh2_pkt_addstring(s->pktout, "publickey");
9201 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
9202 ssh2_pkt_addstring_start(s->pktout);
9203 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9204 ssh2_pkt_addstring_start(s->pktout);
9205 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9206 ssh2_pkt_send(ssh, s->pktout);
9207 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
9209 crWaitUntilV(pktin);
9210 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9212 /* Offer of key refused. */
9219 if (flags & FLAG_VERBOSE) {
9220 c_write_str(ssh, "Authenticating with "
9222 c_write(ssh, s->commentp, s->commentlen);
9223 c_write_str(ssh, "\" from agent\r\n");
9227 * Server is willing to accept the key.
9228 * Construct a SIGN_REQUEST.
9230 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9231 ssh2_pkt_addstring(s->pktout, ssh->username);
9232 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9233 /* service requested */
9234 ssh2_pkt_addstring(s->pktout, "publickey");
9236 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
9237 ssh2_pkt_addstring_start(s->pktout);
9238 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9239 ssh2_pkt_addstring_start(s->pktout);
9240 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9242 /* Ask agent for signature. */
9243 s->siglen = s->pktout->length - 5 + 4 +
9244 ssh->v2_session_id_len;
9245 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9247 s->len = 1; /* message type */
9248 s->len += 4 + s->pklen; /* key blob */
9249 s->len += 4 + s->siglen; /* data to sign */
9250 s->len += 4; /* flags */
9251 s->agentreq = snewn(4 + s->len, char);
9252 PUT_32BIT(s->agentreq, s->len);
9253 s->q = s->agentreq + 4;
9254 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
9255 PUT_32BIT(s->q, s->pklen);
9257 memcpy(s->q, s->pkblob, s->pklen);
9259 PUT_32BIT(s->q, s->siglen);
9261 /* Now the data to be signed... */
9262 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9263 PUT_32BIT(s->q, ssh->v2_session_id_len);
9266 memcpy(s->q, ssh->v2_session_id,
9267 ssh->v2_session_id_len);
9268 s->q += ssh->v2_session_id_len;
9269 memcpy(s->q, s->pktout->data + 5,
9270 s->pktout->length - 5);
9271 s->q += s->pktout->length - 5;
9272 /* And finally the (zero) flags word. */
9274 if (!agent_query(s->agentreq, s->len + 4,
9276 ssh_agent_callback, ssh)) {
9280 bombout(("Unexpected data from server"
9281 " while waiting for agent"
9285 } while (pktin || inlen > 0);
9286 vret = ssh->agent_response;
9287 s->retlen = ssh->agent_response_len;
9292 if (s->retlen >= 9 &&
9293 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
9294 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
9295 logevent("Sending Pageant's response");
9296 ssh2_add_sigblob(ssh, s->pktout,
9297 s->pkblob, s->pklen,
9299 GET_32BIT(s->ret + 5));
9300 ssh2_pkt_send(ssh, s->pktout);
9301 s->type = AUTH_TYPE_PUBLICKEY;
9303 /* FIXME: less drastic response */
9304 bombout(("Pageant failed to answer challenge"));
9310 /* Do we have any keys left to try? */
9311 if (s->pkblob_in_agent) {
9312 s->done_agent = TRUE;
9313 s->tried_pubkey_config = TRUE;
9316 if (s->keyi >= s->nkeys)
9317 s->done_agent = TRUE;
9320 } else if (s->can_pubkey && s->publickey_blob &&
9321 !s->tried_pubkey_config) {
9323 struct ssh2_userkey *key; /* not live over crReturn */
9324 char *passphrase; /* not live over crReturn */
9326 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9328 s->tried_pubkey_config = TRUE;
9331 * Try the public key supplied in the configuration.
9333 * First, offer the public blob to see if the server is
9334 * willing to accept it.
9336 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9337 ssh2_pkt_addstring(s->pktout, ssh->username);
9338 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9339 /* service requested */
9340 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
9341 ssh2_pkt_addbool(s->pktout, FALSE);
9342 /* no signature included */
9343 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
9344 ssh2_pkt_addstring_start(s->pktout);
9345 ssh2_pkt_addstring_data(s->pktout,
9346 (char *)s->publickey_blob,
9347 s->publickey_bloblen);
9348 ssh2_pkt_send(ssh, s->pktout);
9349 logevent("Offered public key");
9351 crWaitUntilV(pktin);
9352 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9353 /* Key refused. Give up. */
9354 s->gotit = TRUE; /* reconsider message next loop */
9355 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
9356 continue; /* process this new message */
9358 logevent("Offer of public key accepted");
9361 * Actually attempt a serious authentication using
9364 if (flags & FLAG_VERBOSE) {
9365 c_write_str(ssh, "Authenticating with public key \"");
9366 c_write_str(ssh, s->publickey_comment);
9367 c_write_str(ssh, "\"\r\n");
9371 const char *error; /* not live over crReturn */
9372 if (s->publickey_encrypted) {
9374 * Get a passphrase from the user.
9376 int ret; /* need not be kept over crReturn */
9377 s->cur_prompt = new_prompts(ssh->frontend);
9378 s->cur_prompt->to_server = FALSE;
9379 s->cur_prompt->name = dupstr("SSH key passphrase");
9380 add_prompt(s->cur_prompt,
9381 dupprintf("Passphrase for key \"%.100s\": ",
9382 s->publickey_comment),
9384 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9387 crWaitUntilV(!pktin);
9388 ret = get_userpass_input(s->cur_prompt,
9393 /* Failed to get a passphrase. Terminate. */
9394 free_prompts(s->cur_prompt);
9395 ssh_disconnect(ssh, NULL,
9396 "Unable to authenticate",
9397 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9402 dupstr(s->cur_prompt->prompts[0]->result);
9403 free_prompts(s->cur_prompt);
9405 passphrase = NULL; /* no passphrase needed */
9409 * Try decrypting the key.
9411 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9412 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
9414 /* burn the evidence */
9415 smemclr(passphrase, strlen(passphrase));
9418 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
9420 (key == SSH2_WRONG_PASSPHRASE)) {
9421 c_write_str(ssh, "Wrong passphrase\r\n");
9423 /* and loop again */
9425 c_write_str(ssh, "Unable to load private key (");
9426 c_write_str(ssh, error);
9427 c_write_str(ssh, ")\r\n");
9429 break; /* try something else */
9435 unsigned char *pkblob, *sigblob, *sigdata;
9436 int pkblob_len, sigblob_len, sigdata_len;
9440 * We have loaded the private key and the server
9441 * has announced that it's willing to accept it.
9442 * Hallelujah. Generate a signature and send it.
9444 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9445 ssh2_pkt_addstring(s->pktout, ssh->username);
9446 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9447 /* service requested */
9448 ssh2_pkt_addstring(s->pktout, "publickey");
9450 ssh2_pkt_addbool(s->pktout, TRUE);
9451 /* signature follows */
9452 ssh2_pkt_addstring(s->pktout, key->alg->name);
9453 pkblob = key->alg->public_blob(key->data,
9455 ssh2_pkt_addstring_start(s->pktout);
9456 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
9460 * The data to be signed is:
9464 * followed by everything so far placed in the
9467 sigdata_len = s->pktout->length - 5 + 4 +
9468 ssh->v2_session_id_len;
9469 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9471 sigdata = snewn(sigdata_len, unsigned char);
9473 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9474 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
9477 memcpy(sigdata+p, ssh->v2_session_id,
9478 ssh->v2_session_id_len);
9479 p += ssh->v2_session_id_len;
9480 memcpy(sigdata+p, s->pktout->data + 5,
9481 s->pktout->length - 5);
9482 p += s->pktout->length - 5;
9483 assert(p == sigdata_len);
9484 sigblob = key->alg->sign(key->data, (char *)sigdata,
9485 sigdata_len, &sigblob_len);
9486 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
9487 sigblob, sigblob_len);
9492 ssh2_pkt_send(ssh, s->pktout);
9493 logevent("Sent public key signature");
9494 s->type = AUTH_TYPE_PUBLICKEY;
9495 key->alg->freekey(key->data);
9499 } else if (s->can_gssapi && !s->tried_gssapi) {
9501 /* GSSAPI Authentication */
9506 s->type = AUTH_TYPE_GSSAPI;
9507 s->tried_gssapi = TRUE;
9509 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
9512 * Pick the highest GSS library on the preference
9518 for (i = 0; i < ngsslibs; i++) {
9519 int want_id = conf_get_int_int(ssh->conf,
9520 CONF_ssh_gsslist, i);
9521 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
9522 if (ssh->gsslibs->libraries[j].id == want_id) {
9523 s->gsslib = &ssh->gsslibs->libraries[j];
9524 goto got_gsslib; /* double break */
9529 * We always expect to have found something in
9530 * the above loop: we only came here if there
9531 * was at least one viable GSS library, and the
9532 * preference list should always mention
9533 * everything and only change the order.
9538 if (s->gsslib->gsslogmsg)
9539 logevent(s->gsslib->gsslogmsg);
9541 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
9542 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9543 ssh2_pkt_addstring(s->pktout, ssh->username);
9544 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9545 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
9546 logevent("Attempting GSSAPI authentication");
9548 /* add mechanism info */
9549 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
9551 /* number of GSSAPI mechanisms */
9552 ssh2_pkt_adduint32(s->pktout,1);
9554 /* length of OID + 2 */
9555 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
9556 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
9559 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
9561 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
9563 ssh2_pkt_send(ssh, s->pktout);
9564 crWaitUntilV(pktin);
9565 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
9566 logevent("GSSAPI authentication request refused");
9570 /* check returned packet ... */
9572 ssh_pkt_getstring(pktin, &data, &len);
9573 s->gss_rcvtok.value = data;
9574 s->gss_rcvtok.length = len;
9575 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
9576 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
9577 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
9578 memcmp((char *)s->gss_rcvtok.value + 2,
9579 s->gss_buf.value,s->gss_buf.length) ) {
9580 logevent("GSSAPI authentication - wrong response from server");
9584 /* now start running */
9585 s->gss_stat = s->gsslib->import_name(s->gsslib,
9588 if (s->gss_stat != SSH_GSS_OK) {
9589 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
9590 logevent("GSSAPI import name failed - Bad service name");
9592 logevent("GSSAPI import name failed");
9596 /* fetch TGT into GSS engine */
9597 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
9599 if (s->gss_stat != SSH_GSS_OK) {
9600 logevent("GSSAPI authentication failed to get credentials");
9601 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9605 /* initial tokens are empty */
9606 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
9607 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
9609 /* now enter the loop */
9611 s->gss_stat = s->gsslib->init_sec_context
9615 conf_get_int(ssh->conf, CONF_gssapifwd),
9619 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
9620 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
9621 logevent("GSSAPI authentication initialisation failed");
9623 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
9624 &s->gss_buf) == SSH_GSS_OK) {
9625 logevent(s->gss_buf.value);
9626 sfree(s->gss_buf.value);
9631 logevent("GSSAPI authentication initialised");
9633 /* Client and server now exchange tokens until GSSAPI
9634 * no longer says CONTINUE_NEEDED */
9636 if (s->gss_sndtok.length != 0) {
9637 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
9638 ssh_pkt_addstring_start(s->pktout);
9639 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
9640 ssh2_pkt_send(ssh, s->pktout);
9641 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
9644 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
9645 crWaitUntilV(pktin);
9646 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
9647 logevent("GSSAPI authentication - bad server response");
9648 s->gss_stat = SSH_GSS_FAILURE;
9651 ssh_pkt_getstring(pktin, &data, &len);
9652 s->gss_rcvtok.value = data;
9653 s->gss_rcvtok.length = len;
9655 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
9657 if (s->gss_stat != SSH_GSS_OK) {
9658 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9659 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9662 logevent("GSSAPI authentication loop finished OK");
9664 /* Now send the MIC */
9666 s->pktout = ssh2_pkt_init(0);
9667 micoffset = s->pktout->length;
9668 ssh_pkt_addstring_start(s->pktout);
9669 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
9670 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
9671 ssh_pkt_addstring(s->pktout, ssh->username);
9672 ssh_pkt_addstring(s->pktout, "ssh-connection");
9673 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
9675 s->gss_buf.value = (char *)s->pktout->data + micoffset;
9676 s->gss_buf.length = s->pktout->length - micoffset;
9678 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
9679 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
9680 ssh_pkt_addstring_start(s->pktout);
9681 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
9682 ssh2_pkt_send(ssh, s->pktout);
9683 s->gsslib->free_mic(s->gsslib, &mic);
9687 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9688 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9691 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
9694 * Keyboard-interactive authentication.
9697 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
9699 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
9701 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9702 ssh2_pkt_addstring(s->pktout, ssh->username);
9703 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9704 /* service requested */
9705 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
9707 ssh2_pkt_addstring(s->pktout, ""); /* lang */
9708 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
9709 ssh2_pkt_send(ssh, s->pktout);
9711 logevent("Attempting keyboard-interactive authentication");
9713 crWaitUntilV(pktin);
9714 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
9715 /* Server is not willing to do keyboard-interactive
9716 * at all (or, bizarrely but legally, accepts the
9717 * user without actually issuing any prompts).
9718 * Give up on it entirely. */
9720 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
9721 s->kbd_inter_refused = TRUE; /* don't try it again */
9726 * Loop while the server continues to send INFO_REQUESTs.
9728 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
9730 char *name, *inst, *lang;
9731 int name_len, inst_len, lang_len;
9735 * We've got a fresh USERAUTH_INFO_REQUEST.
9736 * Get the preamble and start building a prompt.
9738 ssh_pkt_getstring(pktin, &name, &name_len);
9739 ssh_pkt_getstring(pktin, &inst, &inst_len);
9740 ssh_pkt_getstring(pktin, &lang, &lang_len);
9741 s->cur_prompt = new_prompts(ssh->frontend);
9742 s->cur_prompt->to_server = TRUE;
9745 * Get any prompt(s) from the packet.
9747 s->num_prompts = ssh_pkt_getuint32(pktin);
9748 for (i = 0; i < s->num_prompts; i++) {
9752 static char noprompt[] =
9753 "<server failed to send prompt>: ";
9755 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9756 echo = ssh2_pkt_getbool(pktin);
9759 prompt_len = lenof(noprompt)-1;
9761 add_prompt(s->cur_prompt,
9762 dupprintf("%.*s", prompt_len, prompt),
9767 /* FIXME: better prefix to distinguish from
9769 s->cur_prompt->name =
9770 dupprintf("SSH server: %.*s", name_len, name);
9771 s->cur_prompt->name_reqd = TRUE;
9773 s->cur_prompt->name =
9774 dupstr("SSH server authentication");
9775 s->cur_prompt->name_reqd = FALSE;
9777 /* We add a prefix to try to make it clear that a prompt
9778 * has come from the server.
9779 * FIXME: ugly to print "Using..." in prompt _every_
9780 * time round. Can this be done more subtly? */
9781 /* Special case: for reasons best known to themselves,
9782 * some servers send k-i requests with no prompts and
9783 * nothing to display. Keep quiet in this case. */
9784 if (s->num_prompts || name_len || inst_len) {
9785 s->cur_prompt->instruction =
9786 dupprintf("Using keyboard-interactive authentication.%s%.*s",
9787 inst_len ? "\n" : "", inst_len, inst);
9788 s->cur_prompt->instr_reqd = TRUE;
9790 s->cur_prompt->instr_reqd = FALSE;
9794 * Display any instructions, and get the user's
9798 int ret; /* not live over crReturn */
9799 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9802 crWaitUntilV(!pktin);
9803 ret = get_userpass_input(s->cur_prompt, in, inlen);
9808 * Failed to get responses. Terminate.
9810 free_prompts(s->cur_prompt);
9811 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9812 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9819 * Send the response(s) to the server.
9821 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
9822 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
9823 for (i=0; i < s->num_prompts; i++) {
9824 ssh2_pkt_addstring(s->pktout,
9825 s->cur_prompt->prompts[i]->result);
9827 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9830 * Free the prompts structure from this iteration.
9831 * If there's another, a new one will be allocated
9832 * when we return to the top of this while loop.
9834 free_prompts(s->cur_prompt);
9837 * Get the next packet in case it's another
9840 crWaitUntilV(pktin);
9845 * We should have SUCCESS or FAILURE now.
9849 } else if (s->can_passwd) {
9852 * Plain old password authentication.
9854 int ret; /* not live over crReturn */
9855 int changereq_first_time; /* not live over crReturn */
9857 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
9859 s->cur_prompt = new_prompts(ssh->frontend);
9860 s->cur_prompt->to_server = TRUE;
9861 s->cur_prompt->name = dupstr("SSH password");
9862 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
9867 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9870 crWaitUntilV(!pktin);
9871 ret = get_userpass_input(s->cur_prompt, in, inlen);
9876 * Failed to get responses. Terminate.
9878 free_prompts(s->cur_prompt);
9879 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9880 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9885 * Squirrel away the password. (We may need it later if
9886 * asked to change it.)
9888 s->password = dupstr(s->cur_prompt->prompts[0]->result);
9889 free_prompts(s->cur_prompt);
9892 * Send the password packet.
9894 * We pad out the password packet to 256 bytes to make
9895 * it harder for an attacker to find the length of the
9898 * Anyone using a password longer than 256 bytes
9899 * probably doesn't have much to worry about from
9900 * people who find out how long their password is!
9902 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9903 ssh2_pkt_addstring(s->pktout, ssh->username);
9904 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9905 /* service requested */
9906 ssh2_pkt_addstring(s->pktout, "password");
9907 ssh2_pkt_addbool(s->pktout, FALSE);
9908 ssh2_pkt_addstring(s->pktout, s->password);
9909 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9910 logevent("Sent password");
9911 s->type = AUTH_TYPE_PASSWORD;
9914 * Wait for next packet, in case it's a password change
9917 crWaitUntilV(pktin);
9918 changereq_first_time = TRUE;
9920 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
9923 * We're being asked for a new password
9924 * (perhaps not for the first time).
9925 * Loop until the server accepts it.
9928 int got_new = FALSE; /* not live over crReturn */
9929 char *prompt; /* not live over crReturn */
9930 int prompt_len; /* not live over crReturn */
9934 if (changereq_first_time)
9935 msg = "Server requested password change";
9937 msg = "Server rejected new password";
9939 c_write_str(ssh, msg);
9940 c_write_str(ssh, "\r\n");
9943 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9945 s->cur_prompt = new_prompts(ssh->frontend);
9946 s->cur_prompt->to_server = TRUE;
9947 s->cur_prompt->name = dupstr("New SSH password");
9948 s->cur_prompt->instruction =
9949 dupprintf("%.*s", prompt_len, prompt);
9950 s->cur_prompt->instr_reqd = TRUE;
9952 * There's no explicit requirement in the protocol
9953 * for the "old" passwords in the original and
9954 * password-change messages to be the same, and
9955 * apparently some Cisco kit supports password change
9956 * by the user entering a blank password originally
9957 * and the real password subsequently, so,
9958 * reluctantly, we prompt for the old password again.
9960 * (On the other hand, some servers don't even bother
9961 * to check this field.)
9963 add_prompt(s->cur_prompt,
9964 dupstr("Current password (blank for previously entered password): "),
9966 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
9968 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
9972 * Loop until the user manages to enter the same
9977 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9980 crWaitUntilV(!pktin);
9981 ret = get_userpass_input(s->cur_prompt, in, inlen);
9986 * Failed to get responses. Terminate.
9988 /* burn the evidence */
9989 free_prompts(s->cur_prompt);
9990 smemclr(s->password, strlen(s->password));
9992 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9993 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9999 * If the user specified a new original password
10000 * (IYSWIM), overwrite any previously specified
10002 * (A side effect is that the user doesn't have to
10003 * re-enter it if they louse up the new password.)
10005 if (s->cur_prompt->prompts[0]->result[0]) {
10006 smemclr(s->password, strlen(s->password));
10007 /* burn the evidence */
10008 sfree(s->password);
10010 dupstr(s->cur_prompt->prompts[0]->result);
10014 * Check the two new passwords match.
10016 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
10017 s->cur_prompt->prompts[2]->result)
10020 /* They don't. Silly user. */
10021 c_write_str(ssh, "Passwords do not match\r\n");
10026 * Send the new password (along with the old one).
10027 * (see above for padding rationale)
10029 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10030 ssh2_pkt_addstring(s->pktout, ssh->username);
10031 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10032 /* service requested */
10033 ssh2_pkt_addstring(s->pktout, "password");
10034 ssh2_pkt_addbool(s->pktout, TRUE);
10035 ssh2_pkt_addstring(s->pktout, s->password);
10036 ssh2_pkt_addstring(s->pktout,
10037 s->cur_prompt->prompts[1]->result);
10038 free_prompts(s->cur_prompt);
10039 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10040 logevent("Sent new password");
10043 * Now see what the server has to say about it.
10044 * (If it's CHANGEREQ again, it's not happy with the
10047 crWaitUntilV(pktin);
10048 changereq_first_time = FALSE;
10053 * We need to reexamine the current pktin at the top
10054 * of the loop. Either:
10055 * - we weren't asked to change password at all, in
10056 * which case it's a SUCCESS or FAILURE with the
10058 * - we sent a new password, and the server was
10059 * either OK with it (SUCCESS or FAILURE w/partial
10060 * success) or unhappy with the _old_ password
10061 * (FAILURE w/o partial success)
10062 * In any of these cases, we go back to the top of
10063 * the loop and start again.
10068 * We don't need the old password any more, in any
10069 * case. Burn the evidence.
10071 smemclr(s->password, strlen(s->password));
10072 sfree(s->password);
10075 char *str = dupprintf("No supported authentication methods available"
10076 " (server sent: %.*s)",
10079 ssh_disconnect(ssh, str,
10080 "No supported authentication methods available",
10081 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
10091 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
10093 /* Clear up various bits and pieces from authentication. */
10094 if (s->publickey_blob) {
10095 sfree(s->publickey_blob);
10096 sfree(s->publickey_comment);
10098 if (s->agent_response)
10099 sfree(s->agent_response);
10101 if (s->userauth_success && !ssh->bare_connection) {
10103 * We've just received USERAUTH_SUCCESS, and we haven't sent any
10104 * packets since. Signal the transport layer to consider enacting
10105 * delayed compression.
10107 * (Relying on we_are_in is not sufficient, as
10108 * draft-miller-secsh-compression-delayed is quite clear that it
10109 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
10110 * become set for other reasons.)
10112 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
10115 ssh->channels = newtree234(ssh_channelcmp);
10118 * Set up handlers for some connection protocol messages, so we
10119 * don't have to handle them repeatedly in this coroutine.
10121 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
10122 ssh2_msg_channel_window_adjust;
10123 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
10124 ssh2_msg_global_request;
10127 * Create the main session channel.
10129 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
10130 ssh->mainchan = NULL;
10132 ssh->mainchan = snew(struct ssh_channel);
10133 ssh->mainchan->ssh = ssh;
10134 ssh2_channel_init(ssh->mainchan);
10136 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
10138 * Just start a direct-tcpip channel and use it as the main
10141 ssh_send_port_open(ssh->mainchan,
10142 conf_get_str(ssh->conf, CONF_ssh_nc_host),
10143 conf_get_int(ssh->conf, CONF_ssh_nc_port),
10145 ssh->ncmode = TRUE;
10147 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
10148 logevent("Opening session as main channel");
10149 ssh2_pkt_send(ssh, s->pktout);
10150 ssh->ncmode = FALSE;
10152 crWaitUntilV(pktin);
10153 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
10154 bombout(("Server refused to open channel"));
10156 /* FIXME: error data comes back in FAILURE packet */
10158 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
10159 bombout(("Server's channel confirmation cited wrong channel"));
10162 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
10163 ssh->mainchan->halfopen = FALSE;
10164 ssh->mainchan->type = CHAN_MAINSESSION;
10165 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
10166 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
10167 add234(ssh->channels, ssh->mainchan);
10168 update_specials_menu(ssh->frontend);
10169 logevent("Opened main channel");
10173 * Now we have a channel, make dispatch table entries for
10174 * general channel-based messages.
10176 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
10177 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
10178 ssh2_msg_channel_data;
10179 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
10180 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
10181 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
10182 ssh2_msg_channel_open_confirmation;
10183 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
10184 ssh2_msg_channel_open_failure;
10185 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
10186 ssh2_msg_channel_request;
10187 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
10188 ssh2_msg_channel_open;
10189 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
10190 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
10193 * Now the connection protocol is properly up and running, with
10194 * all those dispatch table entries, so it's safe to let
10195 * downstreams start trying to open extra channels through us.
10197 if (ssh->connshare)
10198 share_activate(ssh->connshare, ssh->v_s);
10200 if (ssh->mainchan && ssh_is_simple(ssh)) {
10202 * This message indicates to the server that we promise
10203 * not to try to run any other channel in parallel with
10204 * this one, so it's safe for it to advertise a very large
10205 * window and leave the flow control to TCP.
10207 s->pktout = ssh2_chanreq_init(ssh->mainchan,
10208 "simple@putty.projects.tartarus.org",
10210 ssh2_pkt_send(ssh, s->pktout);
10214 * Enable port forwardings.
10216 ssh_setup_portfwd(ssh, ssh->conf);
10218 if (ssh->mainchan && !ssh->ncmode) {
10220 * Send the CHANNEL_REQUESTS for the main session channel.
10221 * Each one is handled by its own little asynchronous
10225 /* Potentially enable X11 forwarding. */
10226 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
10228 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
10230 if (!ssh->x11disp) {
10231 /* FIXME: return an error message from x11_setup_display */
10232 logevent("X11 forwarding not enabled: unable to"
10233 " initialise X display");
10235 ssh->x11auth = x11_invent_fake_auth
10236 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
10237 ssh->x11auth->disp = ssh->x11disp;
10239 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
10243 /* Potentially enable agent forwarding. */
10244 if (ssh_agent_forwarding_permitted(ssh))
10245 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
10247 /* Now allocate a pty for the session. */
10248 if (!conf_get_int(ssh->conf, CONF_nopty))
10249 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
10251 /* Send environment variables. */
10252 ssh2_setup_env(ssh->mainchan, NULL, NULL);
10255 * Start a shell or a remote command. We may have to attempt
10256 * this twice if the config data has provided a second choice
10263 if (ssh->fallback_cmd) {
10264 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
10265 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
10267 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
10268 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
10272 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
10273 ssh2_response_authconn, NULL);
10274 ssh2_pkt_addstring(s->pktout, cmd);
10276 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
10277 ssh2_response_authconn, NULL);
10278 ssh2_pkt_addstring(s->pktout, cmd);
10280 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
10281 ssh2_response_authconn, NULL);
10283 ssh2_pkt_send(ssh, s->pktout);
10285 crWaitUntilV(pktin);
10287 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
10288 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
10289 bombout(("Unexpected response to shell/command request:"
10290 " packet type %d", pktin->type));
10294 * We failed to start the command. If this is the
10295 * fallback command, we really are finished; if it's
10296 * not, and if the fallback command exists, try falling
10297 * back to it before complaining.
10299 if (!ssh->fallback_cmd &&
10300 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
10301 logevent("Primary command failed; attempting fallback");
10302 ssh->fallback_cmd = TRUE;
10305 bombout(("Server refused to start a shell/command"));
10308 logevent("Started a shell/command");
10313 ssh->editing = ssh->echoing = TRUE;
10316 ssh->state = SSH_STATE_SESSION;
10317 if (ssh->size_needed)
10318 ssh_size(ssh, ssh->term_width, ssh->term_height);
10319 if (ssh->eof_needed)
10320 ssh_special(ssh, TS_EOF);
10326 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
10331 s->try_send = FALSE;
10335 * _All_ the connection-layer packets we expect to
10336 * receive are now handled by the dispatch table.
10337 * Anything that reaches here must be bogus.
10340 bombout(("Strange packet received: type %d", pktin->type));
10342 } else if (ssh->mainchan) {
10344 * We have spare data. Add it to the channel buffer.
10346 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
10347 s->try_send = TRUE;
10351 struct ssh_channel *c;
10353 * Try to send data on all channels if we can.
10355 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
10356 ssh2_try_send_and_unthrottle(ssh, c);
10364 * Handlers for SSH-2 messages that might arrive at any moment.
10366 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
10368 /* log reason code in disconnect message */
10370 int reason, msglen;
10372 reason = ssh_pkt_getuint32(pktin);
10373 ssh_pkt_getstring(pktin, &msg, &msglen);
10375 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
10376 buf = dupprintf("Received disconnect message (%s)",
10377 ssh2_disconnect_reasons[reason]);
10379 buf = dupprintf("Received disconnect message (unknown"
10380 " type %d)", reason);
10384 buf = dupprintf("Disconnection message text: %.*s",
10387 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
10389 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
10390 ssh2_disconnect_reasons[reason] : "unknown",
10395 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
10397 /* log the debug message */
10401 /* XXX maybe we should actually take notice of the return value */
10402 ssh2_pkt_getbool(pktin);
10403 ssh_pkt_getstring(pktin, &msg, &msglen);
10405 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
10408 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
10410 do_ssh2_transport(ssh, NULL, 0, pktin);
10414 * Called if we receive a packet that isn't allowed by the protocol.
10415 * This only applies to packets whose meaning PuTTY understands.
10416 * Entirely unknown packets are handled below.
10418 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
10420 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
10421 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
10423 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
10427 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
10429 struct Packet *pktout;
10430 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
10431 ssh2_pkt_adduint32(pktout, pktin->sequence);
10433 * UNIMPLEMENTED messages MUST appear in the same order as the
10434 * messages they respond to. Hence, never queue them.
10436 ssh2_pkt_send_noqueue(ssh, pktout);
10440 * Handle the top-level SSH-2 protocol.
10442 static void ssh2_protocol_setup(Ssh ssh)
10447 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10449 for (i = 0; i < 256; i++)
10450 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10453 * Initially, we only accept transport messages (and a few generic
10454 * ones). do_ssh2_authconn will add more when it starts.
10455 * Messages that are understood but not currently acceptable go to
10456 * ssh2_msg_unexpected.
10458 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10459 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
10460 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
10461 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
10462 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
10463 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
10464 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
10465 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
10466 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
10467 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
10468 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
10469 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
10470 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
10471 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
10472 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
10473 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
10474 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
10475 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
10476 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
10477 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10478 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10479 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10480 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10481 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10482 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10483 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10484 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10485 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10486 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10487 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10488 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10489 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10490 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10493 * These messages have a special handler from the start.
10495 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10496 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
10497 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10500 static void ssh2_bare_connection_protocol_setup(Ssh ssh)
10505 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10507 for (i = 0; i < 256; i++)
10508 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10511 * Initially, we set all ssh-connection messages to 'unexpected';
10512 * do_ssh2_authconn will fill things in properly. We also handle a
10513 * couple of messages from the transport protocol which aren't
10514 * related to key exchange (UNIMPLEMENTED, IGNORE, DEBUG,
10517 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10518 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10519 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10520 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10521 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10522 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10523 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10524 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10525 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10526 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10527 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10528 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10529 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10530 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10532 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10535 * These messages have a special handler from the start.
10537 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10538 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore;
10539 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10542 static void ssh2_timer(void *ctx, unsigned long now)
10544 Ssh ssh = (Ssh)ctx;
10546 if (ssh->state == SSH_STATE_CLOSED)
10549 if (!ssh->kex_in_progress && !ssh->bare_connection &&
10550 conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
10551 now == ssh->next_rekey) {
10552 do_ssh2_transport(ssh, "timeout", -1, NULL);
10556 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
10557 struct Packet *pktin)
10559 unsigned char *in = (unsigned char *)vin;
10560 if (ssh->state == SSH_STATE_CLOSED)
10564 ssh->incoming_data_size += pktin->encrypted_len;
10565 if (!ssh->kex_in_progress &&
10566 ssh->max_data_size != 0 &&
10567 ssh->incoming_data_size > ssh->max_data_size)
10568 do_ssh2_transport(ssh, "too much data received", -1, NULL);
10572 ssh->packet_dispatch[pktin->type](ssh, pktin);
10573 else if (!ssh->protocol_initial_phase_done)
10574 do_ssh2_transport(ssh, in, inlen, pktin);
10576 do_ssh2_authconn(ssh, in, inlen, pktin);
10579 static void ssh2_bare_connection_protocol(Ssh ssh, void *vin, int inlen,
10580 struct Packet *pktin)
10582 unsigned char *in = (unsigned char *)vin;
10583 if (ssh->state == SSH_STATE_CLOSED)
10587 ssh->packet_dispatch[pktin->type](ssh, pktin);
10589 do_ssh2_authconn(ssh, in, inlen, pktin);
10592 static void ssh_cache_conf_values(Ssh ssh)
10594 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
10598 * Called to set up the connection.
10600 * Returns an error message, or NULL on success.
10602 static const char *ssh_init(void *frontend_handle, void **backend_handle,
10603 Conf *conf, char *host, int port, char **realhost,
10604 int nodelay, int keepalive)
10609 ssh = snew(struct ssh_tag);
10610 ssh->conf = conf_copy(conf);
10611 ssh_cache_conf_values(ssh);
10612 ssh->version = 0; /* when not ready yet */
10614 ssh->cipher = NULL;
10615 ssh->v1_cipher_ctx = NULL;
10616 ssh->crcda_ctx = NULL;
10617 ssh->cscipher = NULL;
10618 ssh->cs_cipher_ctx = NULL;
10619 ssh->sccipher = NULL;
10620 ssh->sc_cipher_ctx = NULL;
10622 ssh->cs_mac_ctx = NULL;
10624 ssh->sc_mac_ctx = NULL;
10625 ssh->cscomp = NULL;
10626 ssh->cs_comp_ctx = NULL;
10627 ssh->sccomp = NULL;
10628 ssh->sc_comp_ctx = NULL;
10630 ssh->kex_ctx = NULL;
10631 ssh->hostkey = NULL;
10632 ssh->hostkey_str = NULL;
10633 ssh->exitcode = -1;
10634 ssh->close_expected = FALSE;
10635 ssh->clean_exit = FALSE;
10636 ssh->state = SSH_STATE_PREPACKET;
10637 ssh->size_needed = FALSE;
10638 ssh->eof_needed = FALSE;
10640 ssh->logctx = NULL;
10641 ssh->deferred_send_data = NULL;
10642 ssh->deferred_len = 0;
10643 ssh->deferred_size = 0;
10644 ssh->fallback_cmd = 0;
10645 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
10646 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
10647 ssh->x11disp = NULL;
10648 ssh->x11auth = NULL;
10649 ssh->x11authtree = newtree234(x11_authcmp);
10650 ssh->v1_compressing = FALSE;
10651 ssh->v2_outgoing_sequence = 0;
10652 ssh->ssh1_rdpkt_crstate = 0;
10653 ssh->ssh2_rdpkt_crstate = 0;
10654 ssh->ssh2_bare_rdpkt_crstate = 0;
10655 ssh->ssh_gotdata_crstate = 0;
10656 ssh->do_ssh1_connection_crstate = 0;
10657 ssh->do_ssh_init_state = NULL;
10658 ssh->do_ssh_connection_init_state = NULL;
10659 ssh->do_ssh1_login_state = NULL;
10660 ssh->do_ssh2_transport_state = NULL;
10661 ssh->do_ssh2_authconn_state = NULL;
10664 ssh->mainchan = NULL;
10665 ssh->throttled_all = 0;
10666 ssh->v1_stdout_throttling = 0;
10668 ssh->queuelen = ssh->queuesize = 0;
10669 ssh->queueing = FALSE;
10670 ssh->qhead = ssh->qtail = NULL;
10671 ssh->deferred_rekey_reason = NULL;
10672 bufchain_init(&ssh->queued_incoming_data);
10673 ssh->frozen = FALSE;
10674 ssh->username = NULL;
10675 ssh->sent_console_eof = FALSE;
10676 ssh->got_pty = FALSE;
10677 ssh->bare_connection = FALSE;
10678 ssh->attempting_connshare = FALSE;
10680 *backend_handle = ssh;
10683 if (crypto_startup() == 0)
10684 return "Microsoft high encryption pack not installed!";
10687 ssh->frontend = frontend_handle;
10688 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
10689 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
10691 ssh->channels = NULL;
10692 ssh->rportfwds = NULL;
10693 ssh->portfwds = NULL;
10698 ssh->conn_throttle_count = 0;
10699 ssh->overall_bufsize = 0;
10700 ssh->fallback_cmd = 0;
10702 ssh->protocol = NULL;
10704 ssh->protocol_initial_phase_done = FALSE;
10706 ssh->pinger = NULL;
10708 ssh->incoming_data_size = ssh->outgoing_data_size =
10709 ssh->deferred_data_size = 0L;
10710 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10711 CONF_ssh_rekey_data));
10712 ssh->kex_in_progress = FALSE;
10715 ssh->gsslibs = NULL;
10718 random_ref(); /* do this now - may be needed by sharing setup code */
10720 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
10729 static void ssh_free(void *handle)
10731 Ssh ssh = (Ssh) handle;
10732 struct ssh_channel *c;
10733 struct ssh_rportfwd *pf;
10734 struct X11FakeAuth *auth;
10736 if (ssh->v1_cipher_ctx)
10737 ssh->cipher->free_context(ssh->v1_cipher_ctx);
10738 if (ssh->cs_cipher_ctx)
10739 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
10740 if (ssh->sc_cipher_ctx)
10741 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
10742 if (ssh->cs_mac_ctx)
10743 ssh->csmac->free_context(ssh->cs_mac_ctx);
10744 if (ssh->sc_mac_ctx)
10745 ssh->scmac->free_context(ssh->sc_mac_ctx);
10746 if (ssh->cs_comp_ctx) {
10748 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
10750 zlib_compress_cleanup(ssh->cs_comp_ctx);
10752 if (ssh->sc_comp_ctx) {
10754 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
10756 zlib_decompress_cleanup(ssh->sc_comp_ctx);
10759 dh_cleanup(ssh->kex_ctx);
10760 sfree(ssh->savedhost);
10762 while (ssh->queuelen-- > 0)
10763 ssh_free_packet(ssh->queue[ssh->queuelen]);
10766 while (ssh->qhead) {
10767 struct queued_handler *qh = ssh->qhead;
10768 ssh->qhead = qh->next;
10771 ssh->qhead = ssh->qtail = NULL;
10773 if (ssh->channels) {
10774 while ((c = delpos234(ssh->channels, 0)) != NULL) {
10777 if (c->u.x11.xconn != NULL)
10778 x11_close(c->u.x11.xconn);
10780 case CHAN_SOCKDATA:
10781 case CHAN_SOCKDATA_DORMANT:
10782 if (c->u.pfd.pf != NULL)
10783 pfd_close(c->u.pfd.pf);
10786 if (ssh->version == 2) {
10787 struct outstanding_channel_request *ocr, *nocr;
10788 ocr = c->v.v2.chanreq_head;
10790 ocr->handler(c, NULL, ocr->ctx);
10795 bufchain_clear(&c->v.v2.outbuffer);
10799 freetree234(ssh->channels);
10800 ssh->channels = NULL;
10803 if (ssh->connshare)
10804 sharestate_free(ssh->connshare);
10806 if (ssh->rportfwds) {
10807 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
10809 freetree234(ssh->rportfwds);
10810 ssh->rportfwds = NULL;
10812 sfree(ssh->deferred_send_data);
10814 x11_free_display(ssh->x11disp);
10815 while ((auth = delpos234(ssh->x11authtree, 0)) != NULL)
10816 x11_free_fake_auth(auth);
10817 freetree234(ssh->x11authtree);
10818 sfree(ssh->do_ssh_init_state);
10819 sfree(ssh->do_ssh1_login_state);
10820 sfree(ssh->do_ssh2_transport_state);
10821 sfree(ssh->do_ssh2_authconn_state);
10824 sfree(ssh->fullhostname);
10825 sfree(ssh->hostkey_str);
10826 if (ssh->crcda_ctx) {
10827 crcda_free_context(ssh->crcda_ctx);
10828 ssh->crcda_ctx = NULL;
10831 ssh_do_close(ssh, TRUE);
10832 expire_timer_context(ssh);
10834 pinger_free(ssh->pinger);
10835 bufchain_clear(&ssh->queued_incoming_data);
10836 sfree(ssh->username);
10837 conf_free(ssh->conf);
10840 ssh_gss_cleanup(ssh->gsslibs);
10848 * Reconfigure the SSH backend.
10850 static void ssh_reconfig(void *handle, Conf *conf)
10852 Ssh ssh = (Ssh) handle;
10853 char *rekeying = NULL, rekey_mandatory = FALSE;
10854 unsigned long old_max_data_size;
10857 pinger_reconfig(ssh->pinger, ssh->conf, conf);
10859 ssh_setup_portfwd(ssh, conf);
10861 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
10862 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
10864 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
10865 unsigned long now = GETTICKCOUNT();
10867 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
10868 rekeying = "timeout shortened";
10870 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
10874 old_max_data_size = ssh->max_data_size;
10875 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10876 CONF_ssh_rekey_data));
10877 if (old_max_data_size != ssh->max_data_size &&
10878 ssh->max_data_size != 0) {
10879 if (ssh->outgoing_data_size > ssh->max_data_size ||
10880 ssh->incoming_data_size > ssh->max_data_size)
10881 rekeying = "data limit lowered";
10884 if (conf_get_int(ssh->conf, CONF_compression) !=
10885 conf_get_int(conf, CONF_compression)) {
10886 rekeying = "compression setting changed";
10887 rekey_mandatory = TRUE;
10890 for (i = 0; i < CIPHER_MAX; i++)
10891 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
10892 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
10893 rekeying = "cipher settings changed";
10894 rekey_mandatory = TRUE;
10896 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
10897 conf_get_int(conf, CONF_ssh2_des_cbc)) {
10898 rekeying = "cipher settings changed";
10899 rekey_mandatory = TRUE;
10902 conf_free(ssh->conf);
10903 ssh->conf = conf_copy(conf);
10904 ssh_cache_conf_values(ssh);
10906 if (!ssh->bare_connection && rekeying) {
10907 if (!ssh->kex_in_progress) {
10908 do_ssh2_transport(ssh, rekeying, -1, NULL);
10909 } else if (rekey_mandatory) {
10910 ssh->deferred_rekey_reason = rekeying;
10916 * Called to send data down the SSH connection.
10918 static int ssh_send(void *handle, char *buf, int len)
10920 Ssh ssh = (Ssh) handle;
10922 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10925 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
10927 return ssh_sendbuffer(ssh);
10931 * Called to query the current amount of buffered stdin data.
10933 static int ssh_sendbuffer(void *handle)
10935 Ssh ssh = (Ssh) handle;
10936 int override_value;
10938 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10942 * If the SSH socket itself has backed up, add the total backup
10943 * size on that to any individual buffer on the stdin channel.
10945 override_value = 0;
10946 if (ssh->throttled_all)
10947 override_value = ssh->overall_bufsize;
10949 if (ssh->version == 1) {
10950 return override_value;
10951 } else if (ssh->version == 2) {
10952 if (!ssh->mainchan)
10953 return override_value;
10955 return (override_value +
10956 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
10963 * Called to set the size of the window from SSH's POV.
10965 static void ssh_size(void *handle, int width, int height)
10967 Ssh ssh = (Ssh) handle;
10968 struct Packet *pktout;
10970 ssh->term_width = width;
10971 ssh->term_height = height;
10973 switch (ssh->state) {
10974 case SSH_STATE_BEFORE_SIZE:
10975 case SSH_STATE_PREPACKET:
10976 case SSH_STATE_CLOSED:
10977 break; /* do nothing */
10978 case SSH_STATE_INTERMED:
10979 ssh->size_needed = TRUE; /* buffer for later */
10981 case SSH_STATE_SESSION:
10982 if (!conf_get_int(ssh->conf, CONF_nopty)) {
10983 if (ssh->version == 1) {
10984 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
10985 PKT_INT, ssh->term_height,
10986 PKT_INT, ssh->term_width,
10987 PKT_INT, 0, PKT_INT, 0, PKT_END);
10988 } else if (ssh->mainchan) {
10989 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
10991 ssh2_pkt_adduint32(pktout, ssh->term_width);
10992 ssh2_pkt_adduint32(pktout, ssh->term_height);
10993 ssh2_pkt_adduint32(pktout, 0);
10994 ssh2_pkt_adduint32(pktout, 0);
10995 ssh2_pkt_send(ssh, pktout);
11003 * Return a list of the special codes that make sense in this
11006 static const struct telnet_special *ssh_get_specials(void *handle)
11008 static const struct telnet_special ssh1_ignore_special[] = {
11009 {"IGNORE message", TS_NOP}
11011 static const struct telnet_special ssh2_ignore_special[] = {
11012 {"IGNORE message", TS_NOP},
11014 static const struct telnet_special ssh2_rekey_special[] = {
11015 {"Repeat key exchange", TS_REKEY},
11017 static const struct telnet_special ssh2_session_specials[] = {
11020 /* These are the signal names defined by RFC 4254.
11021 * They include all the ISO C signals, but are a subset of the POSIX
11022 * required signals. */
11023 {"SIGINT (Interrupt)", TS_SIGINT},
11024 {"SIGTERM (Terminate)", TS_SIGTERM},
11025 {"SIGKILL (Kill)", TS_SIGKILL},
11026 {"SIGQUIT (Quit)", TS_SIGQUIT},
11027 {"SIGHUP (Hangup)", TS_SIGHUP},
11028 {"More signals", TS_SUBMENU},
11029 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
11030 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
11031 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
11032 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
11033 {NULL, TS_EXITMENU}
11035 static const struct telnet_special specials_end[] = {
11036 {NULL, TS_EXITMENU}
11038 /* XXX review this length for any changes: */
11039 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
11040 lenof(ssh2_rekey_special) +
11041 lenof(ssh2_session_specials) +
11042 lenof(specials_end)];
11043 Ssh ssh = (Ssh) handle;
11045 #define ADD_SPECIALS(name) \
11047 assert((i + lenof(name)) <= lenof(ssh_specials)); \
11048 memcpy(&ssh_specials[i], name, sizeof name); \
11049 i += lenof(name); \
11052 if (ssh->version == 1) {
11053 /* Don't bother offering IGNORE if we've decided the remote
11054 * won't cope with it, since we wouldn't bother sending it if
11056 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11057 ADD_SPECIALS(ssh1_ignore_special);
11058 } else if (ssh->version == 2) {
11059 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
11060 ADD_SPECIALS(ssh2_ignore_special);
11061 if (!(ssh->remote_bugs & BUG_SSH2_REKEY) && !ssh->bare_connection)
11062 ADD_SPECIALS(ssh2_rekey_special);
11064 ADD_SPECIALS(ssh2_session_specials);
11065 } /* else we're not ready yet */
11068 ADD_SPECIALS(specials_end);
11069 return ssh_specials;
11073 #undef ADD_SPECIALS
11077 * Send special codes. TS_EOF is useful for `plink', so you
11078 * can send an EOF and collect resulting output (e.g. `plink
11081 static void ssh_special(void *handle, Telnet_Special code)
11083 Ssh ssh = (Ssh) handle;
11084 struct Packet *pktout;
11086 if (code == TS_EOF) {
11087 if (ssh->state != SSH_STATE_SESSION) {
11089 * Buffer the EOF in case we are pre-SESSION, so we can
11090 * send it as soon as we reach SESSION.
11092 if (code == TS_EOF)
11093 ssh->eof_needed = TRUE;
11096 if (ssh->version == 1) {
11097 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
11098 } else if (ssh->mainchan) {
11099 sshfwd_write_eof(ssh->mainchan);
11100 ssh->send_ok = 0; /* now stop trying to read from stdin */
11102 logevent("Sent EOF message");
11103 } else if (code == TS_PING || code == TS_NOP) {
11104 if (ssh->state == SSH_STATE_CLOSED
11105 || ssh->state == SSH_STATE_PREPACKET) return;
11106 if (ssh->version == 1) {
11107 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11108 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
11110 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
11111 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
11112 ssh2_pkt_addstring_start(pktout);
11113 ssh2_pkt_send_noqueue(ssh, pktout);
11116 } else if (code == TS_REKEY) {
11117 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11118 ssh->version == 2) {
11119 do_ssh2_transport(ssh, "at user request", -1, NULL);
11121 } else if (code == TS_BRK) {
11122 if (ssh->state == SSH_STATE_CLOSED
11123 || ssh->state == SSH_STATE_PREPACKET) return;
11124 if (ssh->version == 1) {
11125 logevent("Unable to send BREAK signal in SSH-1");
11126 } else if (ssh->mainchan) {
11127 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
11128 ssh2_pkt_adduint32(pktout, 0); /* default break length */
11129 ssh2_pkt_send(ssh, pktout);
11132 /* Is is a POSIX signal? */
11133 char *signame = NULL;
11134 if (code == TS_SIGABRT) signame = "ABRT";
11135 if (code == TS_SIGALRM) signame = "ALRM";
11136 if (code == TS_SIGFPE) signame = "FPE";
11137 if (code == TS_SIGHUP) signame = "HUP";
11138 if (code == TS_SIGILL) signame = "ILL";
11139 if (code == TS_SIGINT) signame = "INT";
11140 if (code == TS_SIGKILL) signame = "KILL";
11141 if (code == TS_SIGPIPE) signame = "PIPE";
11142 if (code == TS_SIGQUIT) signame = "QUIT";
11143 if (code == TS_SIGSEGV) signame = "SEGV";
11144 if (code == TS_SIGTERM) signame = "TERM";
11145 if (code == TS_SIGUSR1) signame = "USR1";
11146 if (code == TS_SIGUSR2) signame = "USR2";
11147 /* The SSH-2 protocol does in principle support arbitrary named
11148 * signals, including signame@domain, but we don't support those. */
11150 /* It's a signal. */
11151 if (ssh->version == 2 && ssh->mainchan) {
11152 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
11153 ssh2_pkt_addstring(pktout, signame);
11154 ssh2_pkt_send(ssh, pktout);
11155 logeventf(ssh, "Sent signal SIG%s", signame);
11158 /* Never heard of it. Do nothing */
11163 void *new_sock_channel(void *handle, struct PortForwarding *pf)
11165 Ssh ssh = (Ssh) handle;
11166 struct ssh_channel *c;
11167 c = snew(struct ssh_channel);
11170 ssh2_channel_init(c);
11171 c->halfopen = TRUE;
11172 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
11174 add234(ssh->channels, c);
11178 unsigned ssh_alloc_sharing_channel(Ssh ssh, void *sharing_ctx)
11180 struct ssh_channel *c;
11181 c = snew(struct ssh_channel);
11184 ssh2_channel_init(c);
11185 c->type = CHAN_SHARING;
11186 c->u.sharing.ctx = sharing_ctx;
11187 add234(ssh->channels, c);
11191 void ssh_delete_sharing_channel(Ssh ssh, unsigned localid)
11193 struct ssh_channel *c;
11195 c = find234(ssh->channels, &localid, ssh_channelfind);
11197 ssh_channel_destroy(c);
11200 void ssh_send_packet_from_downstream(Ssh ssh, unsigned id, int type,
11201 const void *data, int datalen,
11202 const char *additional_log_text)
11204 struct Packet *pkt;
11206 pkt = ssh2_pkt_init(type);
11207 pkt->downstream_id = id;
11208 pkt->additional_log_text = additional_log_text;
11209 ssh2_pkt_adddata(pkt, data, datalen);
11210 ssh2_pkt_send(ssh, pkt);
11214 * This is called when stdout/stderr (the entity to which
11215 * from_backend sends data) manages to clear some backlog.
11217 static void ssh_unthrottle(void *handle, int bufsize)
11219 Ssh ssh = (Ssh) handle;
11222 if (ssh->version == 1) {
11223 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
11224 ssh->v1_stdout_throttling = 0;
11225 ssh_throttle_conn(ssh, -1);
11228 if (ssh->mainchan) {
11229 ssh2_set_window(ssh->mainchan,
11230 bufsize < ssh->mainchan->v.v2.locmaxwin ?
11231 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
11232 if (ssh_is_simple(ssh))
11235 buflimit = ssh->mainchan->v.v2.locmaxwin;
11236 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
11237 ssh->mainchan->throttling_conn = 0;
11238 ssh_throttle_conn(ssh, -1);
11244 * Now process any SSH connection data that was stashed in our
11245 * queue while we were frozen.
11247 ssh_process_queued_incoming_data(ssh);
11250 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
11252 struct ssh_channel *c = (struct ssh_channel *)channel;
11254 struct Packet *pktout;
11256 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
11258 if (ssh->version == 1) {
11259 send_packet(ssh, SSH1_MSG_PORT_OPEN,
11260 PKT_INT, c->localid,
11263 /* PKT_STR, <org:orgport>, */
11266 pktout = ssh2_chanopen_init(c, "direct-tcpip");
11268 char *trimmed_host = host_strduptrim(hostname);
11269 ssh2_pkt_addstring(pktout, trimmed_host);
11270 sfree(trimmed_host);
11272 ssh2_pkt_adduint32(pktout, port);
11274 * We make up values for the originator data; partly it's
11275 * too much hassle to keep track, and partly I'm not
11276 * convinced the server should be told details like that
11277 * about my local network configuration.
11278 * The "originator IP address" is syntactically a numeric
11279 * IP address, and some servers (e.g., Tectia) get upset
11280 * if it doesn't match this syntax.
11282 ssh2_pkt_addstring(pktout, "0.0.0.0");
11283 ssh2_pkt_adduint32(pktout, 0);
11284 ssh2_pkt_send(ssh, pktout);
11288 static int ssh_connected(void *handle)
11290 Ssh ssh = (Ssh) handle;
11291 return ssh->s != NULL;
11294 static int ssh_sendok(void *handle)
11296 Ssh ssh = (Ssh) handle;
11297 return ssh->send_ok;
11300 static int ssh_ldisc(void *handle, int option)
11302 Ssh ssh = (Ssh) handle;
11303 if (option == LD_ECHO)
11304 return ssh->echoing;
11305 if (option == LD_EDIT)
11306 return ssh->editing;
11310 static void ssh_provide_ldisc(void *handle, void *ldisc)
11312 Ssh ssh = (Ssh) handle;
11313 ssh->ldisc = ldisc;
11316 static void ssh_provide_logctx(void *handle, void *logctx)
11318 Ssh ssh = (Ssh) handle;
11319 ssh->logctx = logctx;
11322 static int ssh_return_exitcode(void *handle)
11324 Ssh ssh = (Ssh) handle;
11325 if (ssh->s != NULL)
11328 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
11332 * cfg_info for SSH is the protocol running in this session.
11333 * (1 or 2 for the full SSH-1 or SSH-2 protocol; -1 for the bare
11334 * SSH-2 connection protocol, i.e. a downstream; 0 for not-decided-yet.)
11336 static int ssh_cfg_info(void *handle)
11338 Ssh ssh = (Ssh) handle;
11339 if (ssh->version == 0)
11340 return 0; /* don't know yet */
11341 else if (ssh->bare_connection)
11344 return ssh->version;
11348 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
11349 * that fails. This variable is the means by which scp.c can reach
11350 * into the SSH code and find out which one it got.
11352 extern int ssh_fallback_cmd(void *handle)
11354 Ssh ssh = (Ssh) handle;
11355 return ssh->fallback_cmd;
11358 Backend ssh_backend = {
11368 ssh_return_exitcode,
11372 ssh_provide_logctx,