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 user but not provided by server"));
2972 if (conf_get_int(ssh->conf, CONF_sshprot) == 3 && !s->proto2) {
2973 bombout(("SSH protocol version 2 required by user but not provided by server"));
2977 if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1))
2982 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2984 /* Send the version string, if we haven't already */
2985 if (conf_get_int(ssh->conf, CONF_sshprot) != 3)
2986 ssh_send_verstring(ssh, protoname, s->version);
2988 if (ssh->version == 2) {
2991 * Record their version string.
2993 len = strcspn(s->vstring, "\015\012");
2994 ssh->v_s = snewn(len + 1, char);
2995 memcpy(ssh->v_s, s->vstring, len);
2999 * Initialise SSH-2 protocol.
3001 ssh->protocol = ssh2_protocol;
3002 ssh2_protocol_setup(ssh);
3003 ssh->s_rdpkt = ssh2_rdpkt;
3006 * Initialise SSH-1 protocol.
3008 ssh->protocol = ssh1_protocol;
3009 ssh1_protocol_setup(ssh);
3010 ssh->s_rdpkt = ssh1_rdpkt;
3012 if (ssh->version == 2)
3013 do_ssh2_transport(ssh, NULL, -1, NULL);
3015 update_specials_menu(ssh->frontend);
3016 ssh->state = SSH_STATE_BEFORE_SIZE;
3017 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3024 static int do_ssh_connection_init(Ssh ssh, unsigned char c)
3027 * Ordinary SSH begins with the banner "SSH-x.y-...". This is just
3028 * the ssh-connection part, extracted and given a trivial binary
3029 * packet protocol, so we replace 'SSH-' at the start with a new
3030 * name. In proper SSH style (though of course this part of the
3031 * proper SSH protocol _isn't_ subject to this kind of
3032 * DNS-domain-based extension), we define the new name in our
3035 static const char protoname[] =
3036 "SSHCONNECTION@putty.projects.tartarus.org-";
3038 struct do_ssh_connection_init_state {
3046 crState(do_ssh_connection_init_state);
3050 /* Search for a line beginning with the protocol name prefix in
3053 for (s->i = 0; protoname[s->i]; s->i++) {
3054 if ((char)c != protoname[s->i]) goto no;
3064 s->vstrsize = sizeof(protoname) + 16;
3065 s->vstring = snewn(s->vstrsize, char);
3066 strcpy(s->vstring, protoname);
3067 s->vslen = strlen(protoname);
3070 if (s->vslen >= s->vstrsize - 1) {
3072 s->vstring = sresize(s->vstring, s->vstrsize, char);
3074 s->vstring[s->vslen++] = c;
3077 s->version[s->i] = '\0';
3079 } else if (s->i < sizeof(s->version) - 1)
3080 s->version[s->i++] = c;
3081 } else if (c == '\012')
3083 crReturn(1); /* get another char */
3086 ssh->agentfwd_enabled = FALSE;
3087 ssh->rdpkt2_bare_state.incoming_sequence = 0;
3089 s->vstring[s->vslen] = 0;
3090 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
3091 logeventf(ssh, "Server version: %s", s->vstring);
3092 ssh_detect_bugs(ssh, s->vstring);
3095 * Decide which SSH protocol version to support. This is easy in
3096 * bare ssh-connection mode: only 2.0 is legal.
3098 if (ssh_versioncmp(s->version, "2.0") < 0) {
3099 bombout(("Server announces compatibility with SSH-1 in bare ssh-connection protocol"));
3102 if (conf_get_int(ssh->conf, CONF_sshprot) == 0) {
3103 bombout(("Bare ssh-connection protocol cannot be run in SSH-1-only mode"));
3109 logeventf(ssh, "Using bare ssh-connection protocol");
3111 /* Send the version string, if we haven't already */
3112 ssh_send_verstring(ssh, protoname, s->version);
3115 * Initialise bare connection protocol.
3117 ssh->protocol = ssh2_bare_connection_protocol;
3118 ssh2_bare_connection_protocol_setup(ssh);
3119 ssh->s_rdpkt = ssh2_bare_connection_rdpkt;
3121 update_specials_menu(ssh->frontend);
3122 ssh->state = SSH_STATE_BEFORE_SIZE;
3123 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3126 * Get authconn (really just conn) under way.
3128 do_ssh2_authconn(ssh, NULL, 0, NULL);
3135 static void ssh_process_incoming_data(Ssh ssh,
3136 unsigned char **data, int *datalen)
3138 struct Packet *pktin;
3140 pktin = ssh->s_rdpkt(ssh, data, datalen);
3142 ssh->protocol(ssh, NULL, 0, pktin);
3143 ssh_free_packet(pktin);
3147 static void ssh_queue_incoming_data(Ssh ssh,
3148 unsigned char **data, int *datalen)
3150 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
3155 static void ssh_process_queued_incoming_data(Ssh ssh)
3158 unsigned char *data;
3161 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
3162 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
3166 while (!ssh->frozen && len > 0)
3167 ssh_process_incoming_data(ssh, &data, &len);
3170 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
3174 static void ssh_set_frozen(Ssh ssh, int frozen)
3177 sk_set_frozen(ssh->s, frozen);
3178 ssh->frozen = frozen;
3181 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
3183 /* Log raw data, if we're in that mode. */
3185 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
3186 0, NULL, NULL, 0, NULL);
3188 crBegin(ssh->ssh_gotdata_crstate);
3191 * To begin with, feed the characters one by one to the
3192 * protocol initialisation / selection function do_ssh_init().
3193 * When that returns 0, we're done with the initial greeting
3194 * exchange and can move on to packet discipline.
3197 int ret; /* need not be kept across crReturn */
3199 crReturnV; /* more data please */
3200 ret = ssh->do_ssh_init(ssh, *data);
3208 * We emerge from that loop when the initial negotiation is
3209 * over and we have selected an s_rdpkt function. Now pass
3210 * everything to s_rdpkt, and then pass the resulting packets
3211 * to the proper protocol handler.
3215 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
3217 ssh_queue_incoming_data(ssh, &data, &datalen);
3218 /* This uses up all data and cannot cause anything interesting
3219 * to happen; indeed, for anything to happen at all, we must
3220 * return, so break out. */
3222 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
3223 /* This uses up some or all data, and may freeze the
3225 ssh_process_queued_incoming_data(ssh);
3227 /* This uses up some or all data, and may freeze the
3229 ssh_process_incoming_data(ssh, &data, &datalen);
3231 /* FIXME this is probably EBW. */
3232 if (ssh->state == SSH_STATE_CLOSED)
3235 /* We're out of data. Go and get some more. */
3241 static int ssh_do_close(Ssh ssh, int notify_exit)
3244 struct ssh_channel *c;
3246 ssh->state = SSH_STATE_CLOSED;
3247 expire_timer_context(ssh);
3252 notify_remote_exit(ssh->frontend);
3257 * Now we must shut down any port- and X-forwarded channels going
3258 * through this connection.
3260 if (ssh->channels) {
3261 while (NULL != (c = index234(ssh->channels, 0))) {
3264 x11_close(c->u.x11.xconn);
3267 case CHAN_SOCKDATA_DORMANT:
3268 pfd_close(c->u.pfd.pf);
3271 del234(ssh->channels, c); /* moving next one to index 0 */
3272 if (ssh->version == 2)
3273 bufchain_clear(&c->v.v2.outbuffer);
3278 * Go through port-forwardings, and close any associated
3279 * listening sockets.
3281 if (ssh->portfwds) {
3282 struct ssh_portfwd *pf;
3283 while (NULL != (pf = index234(ssh->portfwds, 0))) {
3284 /* Dispose of any listening socket. */
3286 pfl_terminate(pf->local);
3287 del234(ssh->portfwds, pf); /* moving next one to index 0 */
3290 freetree234(ssh->portfwds);
3291 ssh->portfwds = NULL;
3297 static void ssh_socket_log(Plug plug, int type, SockAddr addr, int port,
3298 const char *error_msg, int error_code)
3300 Ssh ssh = (Ssh) plug;
3301 char addrbuf[256], *msg;
3303 if (ssh->attempting_connshare) {
3305 * While we're attempting connection sharing, don't loudly log
3306 * everything that happens. Real TCP connections need to be
3307 * logged when we _start_ trying to connect, because it might
3308 * be ages before they respond if something goes wrong; but
3309 * connection sharing is local and quick to respond, and it's
3310 * sufficient to simply wait and see whether it worked
3314 sk_getaddr(addr, addrbuf, lenof(addrbuf));
3317 if (sk_addr_needs_port(addr)) {
3318 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
3320 msg = dupprintf("Connecting to %s", addrbuf);
3323 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
3331 void ssh_connshare_log(Ssh ssh, int event, const char *logtext,
3332 const char *ds_err, const char *us_err)
3334 if (event == SHARE_NONE) {
3335 /* In this case, 'logtext' is an error message indicating a
3336 * reason why connection sharing couldn't be set up _at all_.
3337 * Failing that, ds_err and us_err indicate why we couldn't be
3338 * a downstream and an upstream respectively. */
3340 logeventf(ssh, "Could not set up connection sharing: %s", logtext);
3343 logeventf(ssh, "Could not set up connection sharing"
3344 " as downstream: %s", ds_err);
3346 logeventf(ssh, "Could not set up connection sharing"
3347 " as upstream: %s", us_err);
3349 } else if (event == SHARE_DOWNSTREAM) {
3350 /* In this case, 'logtext' is a local endpoint address */
3351 logeventf(ssh, "Using existing shared connection at %s", logtext);
3352 /* Also we should mention this in the console window to avoid
3353 * confusing users as to why this window doesn't behave the
3355 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3356 c_write_str(ssh,"Reusing a shared connection to this server.\r\n");
3358 } else if (event == SHARE_UPSTREAM) {
3359 /* In this case, 'logtext' is a local endpoint address too */
3360 logeventf(ssh, "Sharing this connection at %s", logtext);
3364 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
3367 Ssh ssh = (Ssh) plug;
3368 int need_notify = ssh_do_close(ssh, FALSE);
3371 if (!ssh->close_expected)
3372 error_msg = "Server unexpectedly closed network connection";
3374 error_msg = "Server closed network connection";
3377 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
3381 notify_remote_exit(ssh->frontend);
3384 logevent(error_msg);
3385 if (!ssh->close_expected || !ssh->clean_exit)
3386 connection_fatal(ssh->frontend, "%s", error_msg);
3390 static int ssh_receive(Plug plug, int urgent, char *data, int len)
3392 Ssh ssh = (Ssh) plug;
3393 ssh_gotdata(ssh, (unsigned char *)data, len);
3394 if (ssh->state == SSH_STATE_CLOSED) {
3395 ssh_do_close(ssh, TRUE);
3401 static void ssh_sent(Plug plug, int bufsize)
3403 Ssh ssh = (Ssh) plug;
3405 * If the send backlog on the SSH socket itself clears, we
3406 * should unthrottle the whole world if it was throttled.
3408 if (bufsize < SSH_MAX_BACKLOG)
3409 ssh_throttle_all(ssh, 0, bufsize);
3413 * Connect to specified host and port.
3414 * Returns an error message, or NULL on success.
3415 * Also places the canonical host name into `realhost'. It must be
3416 * freed by the caller.
3418 static const char *connect_to_host(Ssh ssh, char *host, int port,
3419 char **realhost, int nodelay, int keepalive)
3421 static const struct plug_function_table fn_table = {
3432 int addressfamily, sshprot;
3434 loghost = conf_get_str(ssh->conf, CONF_loghost);
3439 tmphost = dupstr(loghost);
3440 ssh->savedport = 22; /* default ssh port */
3443 * A colon suffix on the hostname string also lets us affect
3444 * savedport. (Unless there are multiple colons, in which case
3445 * we assume this is an unbracketed IPv6 literal.)
3447 colon = host_strrchr(tmphost, ':');
3448 if (colon && colon == host_strchr(tmphost, ':')) {
3451 ssh->savedport = atoi(colon);
3454 ssh->savedhost = host_strduptrim(tmphost);
3457 ssh->savedhost = host_strduptrim(host);
3459 port = 22; /* default ssh port */
3460 ssh->savedport = port;
3463 ssh->fn = &fn_table; /* make 'ssh' usable as a Plug */
3466 * Try connection-sharing, in case that means we don't open a
3467 * socket after all. ssh_connection_sharing_init will connect to a
3468 * previously established upstream if it can, and failing that,
3469 * establish a listening socket for _us_ to be the upstream. In
3470 * the latter case it will return NULL just as if it had done
3471 * nothing, because here we only need to care if we're a
3472 * downstream and need to do our connection setup differently.
3474 ssh->connshare = NULL;
3475 ssh->attempting_connshare = TRUE; /* affects socket logging behaviour */
3476 ssh->s = ssh_connection_sharing_init(ssh->savedhost, ssh->savedport,
3477 ssh->conf, ssh, &ssh->connshare);
3478 ssh->attempting_connshare = FALSE;
3479 if (ssh->s != NULL) {
3481 * We are a downstream.
3483 ssh->bare_connection = TRUE;
3484 ssh->do_ssh_init = do_ssh_connection_init;
3485 ssh->fullhostname = NULL;
3486 *realhost = dupstr(host); /* best we can do */
3489 * We're not a downstream, so open a normal socket.
3491 ssh->do_ssh_init = do_ssh_init;
3496 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
3497 logeventf(ssh, "Looking up host \"%s\"%s", host,
3498 (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
3499 (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
3500 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily);
3501 if ((err = sk_addr_error(addr)) != NULL) {
3505 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3507 ssh->s = new_connection(addr, *realhost, port,
3508 0, 1, nodelay, keepalive,
3509 (Plug) ssh, ssh->conf);
3510 if ((err = sk_socket_error(ssh->s)) != NULL) {
3512 notify_remote_exit(ssh->frontend);
3518 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3519 * send the version string too.
3521 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3524 if (sshprot == 3 && !ssh->bare_connection) {
3526 ssh_send_verstring(ssh, "SSH-", NULL);
3530 * loghost, if configured, overrides realhost.
3534 *realhost = dupstr(loghost);
3541 * Throttle or unthrottle the SSH connection.
3543 static void ssh_throttle_conn(Ssh ssh, int adjust)
3545 int old_count = ssh->conn_throttle_count;
3546 ssh->conn_throttle_count += adjust;
3547 assert(ssh->conn_throttle_count >= 0);
3548 if (ssh->conn_throttle_count && !old_count) {
3549 ssh_set_frozen(ssh, 1);
3550 } else if (!ssh->conn_throttle_count && old_count) {
3551 ssh_set_frozen(ssh, 0);
3556 * Throttle or unthrottle _all_ local data streams (for when sends
3557 * on the SSH connection itself back up).
3559 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3562 struct ssh_channel *c;
3564 if (enable == ssh->throttled_all)
3566 ssh->throttled_all = enable;
3567 ssh->overall_bufsize = bufsize;
3570 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3572 case CHAN_MAINSESSION:
3574 * This is treated separately, outside the switch.
3578 x11_override_throttle(c->u.x11.xconn, enable);
3581 /* Agent channels require no buffer management. */
3584 pfd_override_throttle(c->u.pfd.pf, enable);
3590 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3592 Ssh ssh = (Ssh) sshv;
3594 ssh->agent_response = reply;
3595 ssh->agent_response_len = replylen;
3597 if (ssh->version == 1)
3598 do_ssh1_login(ssh, NULL, -1, NULL);
3600 do_ssh2_authconn(ssh, NULL, -1, NULL);
3603 static void ssh_dialog_callback(void *sshv, int ret)
3605 Ssh ssh = (Ssh) sshv;
3607 ssh->user_response = ret;
3609 if (ssh->version == 1)
3610 do_ssh1_login(ssh, NULL, -1, NULL);
3612 do_ssh2_transport(ssh, NULL, -1, NULL);
3615 * This may have unfrozen the SSH connection, so do a
3618 ssh_process_queued_incoming_data(ssh);
3621 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3623 struct ssh_channel *c = (struct ssh_channel *)cv;
3625 void *sentreply = reply;
3627 c->u.a.outstanding_requests--;
3629 /* Fake SSH_AGENT_FAILURE. */
3630 sentreply = "\0\0\0\1\5";
3633 if (ssh->version == 2) {
3634 ssh2_add_channel_data(c, sentreply, replylen);
3637 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3638 PKT_INT, c->remoteid,
3640 PKT_DATA, sentreply, replylen,
3646 * If we've already seen an incoming EOF but haven't sent an
3647 * outgoing one, this may be the moment to send it.
3649 if (c->u.a.outstanding_requests == 0 && (c->closes & CLOSES_RCVD_EOF))
3650 sshfwd_write_eof(c);
3654 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3655 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3656 * => log `wire_reason'.
3658 static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
3659 int code, int clean_exit)
3663 client_reason = wire_reason;
3665 error = dupprintf("Disconnected: %s", client_reason);
3667 error = dupstr("Disconnected");
3669 if (ssh->version == 1) {
3670 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3672 } else if (ssh->version == 2) {
3673 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3674 ssh2_pkt_adduint32(pktout, code);
3675 ssh2_pkt_addstring(pktout, wire_reason);
3676 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3677 ssh2_pkt_send_noqueue(ssh, pktout);
3680 ssh->close_expected = TRUE;
3681 ssh->clean_exit = clean_exit;
3682 ssh_closing((Plug)ssh, error, 0, 0);
3686 int verify_ssh_manual_host_key(Ssh ssh, const char *fingerprint,
3687 const struct ssh_signkey *ssh2keytype,
3690 if (!conf_get_str_nthstrkey(ssh->conf, CONF_ssh_manual_hostkeys, 0)) {
3691 return -1; /* no manual keys configured */
3696 * The fingerprint string we've been given will have things
3697 * like 'ssh-rsa 2048' at the front of it. Strip those off and
3698 * narrow down to just the colon-separated hex block at the
3699 * end of the string.
3701 const char *p = strrchr(fingerprint, ' ');
3702 fingerprint = p ? p+1 : fingerprint;
3703 /* Quick sanity checks, including making sure it's in lowercase */
3704 assert(strlen(fingerprint) == 16*3 - 1);
3705 assert(fingerprint[2] == ':');
3706 assert(fingerprint[strspn(fingerprint, "0123456789abcdef:")] == 0);
3708 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3710 return 1; /* success */
3715 * Construct the base64-encoded public key blob and see if
3718 unsigned char *binblob;
3720 int binlen, atoms, i;
3721 binblob = ssh2keytype->public_blob(ssh2keydata, &binlen);
3722 atoms = (binlen + 2) / 3;
3723 base64blob = snewn(atoms * 4 + 1, char);
3724 for (i = 0; i < atoms; i++)
3725 base64_encode_atom(binblob + 3*i, binlen - 3*i, base64blob + 4*i);
3726 base64blob[atoms * 4] = '\0';
3728 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3731 return 1; /* success */
3740 * Handle the key exchange and user authentication phases.
3742 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
3743 struct Packet *pktin)
3746 unsigned char cookie[8], *ptr;
3747 struct MD5Context md5c;
3748 struct do_ssh1_login_state {
3751 unsigned char *rsabuf, *keystr1, *keystr2;
3752 unsigned long supported_ciphers_mask, supported_auths_mask;
3753 int tried_publickey, tried_agent;
3754 int tis_auth_refused, ccard_auth_refused;
3755 unsigned char session_id[16];
3757 void *publickey_blob;
3758 int publickey_bloblen;
3759 char *publickey_comment;
3760 int publickey_encrypted;
3761 prompts_t *cur_prompt;
3764 unsigned char request[5], *response, *p;
3774 struct RSAKey servkey, hostkey;
3776 crState(do_ssh1_login_state);
3783 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
3784 bombout(("Public key packet not received"));
3788 logevent("Received public keys");
3790 ptr = ssh_pkt_getdata(pktin, 8);
3792 bombout(("SSH-1 public key packet stopped before random cookie"));
3795 memcpy(cookie, ptr, 8);
3797 if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) ||
3798 !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) {
3799 bombout(("Failed to read SSH-1 public keys from public key packet"));
3804 * Log the host key fingerprint.
3808 logevent("Host key fingerprint is:");
3809 strcpy(logmsg, " ");
3810 s->hostkey.comment = NULL;
3811 rsa_fingerprint(logmsg + strlen(logmsg),
3812 sizeof(logmsg) - strlen(logmsg), &s->hostkey);
3816 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3817 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3818 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
3819 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
3820 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
3822 ssh->v1_local_protoflags =
3823 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3824 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
3827 MD5Update(&md5c, s->keystr2, s->hostkey.bytes);
3828 MD5Update(&md5c, s->keystr1, s->servkey.bytes);
3829 MD5Update(&md5c, cookie, 8);
3830 MD5Final(s->session_id, &md5c);
3832 for (i = 0; i < 32; i++)
3833 ssh->session_key[i] = random_byte();
3836 * Verify that the `bits' and `bytes' parameters match.
3838 if (s->hostkey.bits > s->hostkey.bytes * 8 ||
3839 s->servkey.bits > s->servkey.bytes * 8) {
3840 bombout(("SSH-1 public keys were badly formatted"));
3844 s->len = (s->hostkey.bytes > s->servkey.bytes ?
3845 s->hostkey.bytes : s->servkey.bytes);
3847 s->rsabuf = snewn(s->len, unsigned char);
3850 * Verify the host key.
3854 * First format the key into a string.
3856 int len = rsastr_len(&s->hostkey);
3857 char fingerprint[100];
3858 char *keystr = snewn(len, char);
3859 rsastr_fmt(keystr, &s->hostkey);
3860 rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey);
3862 /* First check against manually configured host keys. */
3863 s->dlgret = verify_ssh_manual_host_key(ssh, fingerprint, NULL, NULL);
3864 if (s->dlgret == 0) { /* did not match */
3865 bombout(("Host key did not appear in manually configured list"));
3867 } else if (s->dlgret < 0) { /* none configured; use standard handling */
3868 ssh_set_frozen(ssh, 1);
3869 s->dlgret = verify_ssh_host_key(ssh->frontend,
3870 ssh->savedhost, ssh->savedport,
3871 "rsa", keystr, fingerprint,
3872 ssh_dialog_callback, ssh);
3874 if (s->dlgret < 0) {
3878 bombout(("Unexpected data from server while waiting"
3879 " for user host key response"));
3882 } while (pktin || inlen > 0);
3883 s->dlgret = ssh->user_response;
3885 ssh_set_frozen(ssh, 0);
3887 if (s->dlgret == 0) {
3888 ssh_disconnect(ssh, "User aborted at host key verification",
3895 for (i = 0; i < 32; i++) {
3896 s->rsabuf[i] = ssh->session_key[i];
3898 s->rsabuf[i] ^= s->session_id[i];
3901 if (s->hostkey.bytes > s->servkey.bytes) {
3902 ret = rsaencrypt(s->rsabuf, 32, &s->servkey);
3904 ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey);
3906 ret = rsaencrypt(s->rsabuf, 32, &s->hostkey);
3908 ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey);
3911 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3915 logevent("Encrypted session key");
3918 int cipher_chosen = 0, warn = 0;
3919 char *cipher_string = NULL;
3921 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
3922 int next_cipher = conf_get_int_int(ssh->conf,
3923 CONF_ssh_cipherlist, i);
3924 if (next_cipher == CIPHER_WARN) {
3925 /* If/when we choose a cipher, warn about it */
3927 } else if (next_cipher == CIPHER_AES) {
3928 /* XXX Probably don't need to mention this. */
3929 logevent("AES not supported in SSH-1, skipping");
3931 switch (next_cipher) {
3932 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
3933 cipher_string = "3DES"; break;
3934 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
3935 cipher_string = "Blowfish"; break;
3936 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
3937 cipher_string = "single-DES"; break;
3939 if (s->supported_ciphers_mask & (1 << s->cipher_type))
3943 if (!cipher_chosen) {
3944 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
3945 bombout(("Server violates SSH-1 protocol by not "
3946 "supporting 3DES encryption"));
3948 /* shouldn't happen */
3949 bombout(("No supported ciphers found"));
3953 /* Warn about chosen cipher if necessary. */
3955 ssh_set_frozen(ssh, 1);
3956 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3957 ssh_dialog_callback, ssh);
3958 if (s->dlgret < 0) {
3962 bombout(("Unexpected data from server while waiting"
3963 " for user response"));
3966 } while (pktin || inlen > 0);
3967 s->dlgret = ssh->user_response;
3969 ssh_set_frozen(ssh, 0);
3970 if (s->dlgret == 0) {
3971 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3978 switch (s->cipher_type) {
3979 case SSH_CIPHER_3DES:
3980 logevent("Using 3DES encryption");
3982 case SSH_CIPHER_DES:
3983 logevent("Using single-DES encryption");
3985 case SSH_CIPHER_BLOWFISH:
3986 logevent("Using Blowfish encryption");
3990 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3991 PKT_CHAR, s->cipher_type,
3992 PKT_DATA, cookie, 8,
3993 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3994 PKT_DATA, s->rsabuf, s->len,
3995 PKT_INT, ssh->v1_local_protoflags, PKT_END);
3997 logevent("Trying to enable encryption...");
4001 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
4002 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
4004 ssh->v1_cipher_ctx = ssh->cipher->make_context();
4005 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
4006 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
4008 ssh->crcda_ctx = crcda_make_context();
4009 logevent("Installing CRC compensation attack detector");
4011 if (s->servkey.modulus) {
4012 sfree(s->servkey.modulus);
4013 s->servkey.modulus = NULL;
4015 if (s->servkey.exponent) {
4016 sfree(s->servkey.exponent);
4017 s->servkey.exponent = NULL;
4019 if (s->hostkey.modulus) {
4020 sfree(s->hostkey.modulus);
4021 s->hostkey.modulus = NULL;
4023 if (s->hostkey.exponent) {
4024 sfree(s->hostkey.exponent);
4025 s->hostkey.exponent = NULL;
4029 if (pktin->type != SSH1_SMSG_SUCCESS) {
4030 bombout(("Encryption not successfully enabled"));
4034 logevent("Successfully started encryption");
4036 fflush(stdout); /* FIXME eh? */
4038 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
4039 int ret; /* need not be kept over crReturn */
4040 s->cur_prompt = new_prompts(ssh->frontend);
4041 s->cur_prompt->to_server = TRUE;
4042 s->cur_prompt->name = dupstr("SSH login name");
4043 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
4044 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4047 crWaitUntil(!pktin);
4048 ret = get_userpass_input(s->cur_prompt, in, inlen);
4053 * Failed to get a username. Terminate.
4055 free_prompts(s->cur_prompt);
4056 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
4059 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
4060 free_prompts(s->cur_prompt);
4063 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
4065 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
4067 if (flags & FLAG_INTERACTIVE &&
4068 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
4069 c_write_str(ssh, userlog);
4070 c_write_str(ssh, "\r\n");
4078 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
4079 /* We must not attempt PK auth. Pretend we've already tried it. */
4080 s->tried_publickey = s->tried_agent = 1;
4082 s->tried_publickey = s->tried_agent = 0;
4084 s->tis_auth_refused = s->ccard_auth_refused = 0;
4086 * Load the public half of any configured keyfile for later use.
4088 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4089 if (!filename_is_null(s->keyfile)) {
4091 logeventf(ssh, "Reading private key file \"%.150s\"",
4092 filename_to_str(s->keyfile));
4093 keytype = key_type(s->keyfile);
4094 if (keytype == SSH_KEYTYPE_SSH1) {
4096 if (rsakey_pubblob(s->keyfile,
4097 &s->publickey_blob, &s->publickey_bloblen,
4098 &s->publickey_comment, &error)) {
4099 s->publickey_encrypted = rsakey_encrypted(s->keyfile,
4103 logeventf(ssh, "Unable to load private key (%s)", error);
4104 msgbuf = dupprintf("Unable to load private key file "
4105 "\"%.150s\" (%s)\r\n",
4106 filename_to_str(s->keyfile),
4108 c_write_str(ssh, msgbuf);
4110 s->publickey_blob = NULL;
4114 logeventf(ssh, "Unable to use this key file (%s)",
4115 key_type_to_str(keytype));
4116 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4118 filename_to_str(s->keyfile),
4119 key_type_to_str(keytype));
4120 c_write_str(ssh, msgbuf);
4122 s->publickey_blob = NULL;
4125 s->publickey_blob = NULL;
4127 while (pktin->type == SSH1_SMSG_FAILURE) {
4128 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
4130 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
4132 * Attempt RSA authentication using Pageant.
4138 logevent("Pageant is running. Requesting keys.");
4140 /* Request the keys held by the agent. */
4141 PUT_32BIT(s->request, 1);
4142 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
4143 if (!agent_query(s->request, 5, &r, &s->responselen,
4144 ssh_agent_callback, ssh)) {
4148 bombout(("Unexpected data from server while waiting"
4149 " for agent response"));
4152 } while (pktin || inlen > 0);
4153 r = ssh->agent_response;
4154 s->responselen = ssh->agent_response_len;
4156 s->response = (unsigned char *) r;
4157 if (s->response && s->responselen >= 5 &&
4158 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
4159 s->p = s->response + 5;
4160 s->nkeys = toint(GET_32BIT(s->p));
4162 logeventf(ssh, "Pageant reported negative key count %d",
4167 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
4168 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4169 unsigned char *pkblob = s->p;
4173 do { /* do while (0) to make breaking easy */
4174 n = ssh1_read_bignum
4175 (s->p, toint(s->responselen-(s->p-s->response)),
4180 n = ssh1_read_bignum
4181 (s->p, toint(s->responselen-(s->p-s->response)),
4186 if (s->responselen - (s->p-s->response) < 4)
4188 s->commentlen = toint(GET_32BIT(s->p));
4190 if (s->commentlen < 0 ||
4191 toint(s->responselen - (s->p-s->response)) <
4194 s->commentp = (char *)s->p;
4195 s->p += s->commentlen;
4199 logevent("Pageant key list packet was truncated");
4203 if (s->publickey_blob) {
4204 if (!memcmp(pkblob, s->publickey_blob,
4205 s->publickey_bloblen)) {
4206 logeventf(ssh, "Pageant key #%d matches "
4207 "configured key file", s->keyi);
4208 s->tried_publickey = 1;
4210 /* Skip non-configured key */
4213 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
4214 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4215 PKT_BIGNUM, s->key.modulus, PKT_END);
4217 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4218 logevent("Key refused");
4221 logevent("Received RSA challenge");
4222 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4223 bombout(("Server's RSA challenge was badly formatted"));
4228 char *agentreq, *q, *ret;
4231 len = 1 + 4; /* message type, bit count */
4232 len += ssh1_bignum_length(s->key.exponent);
4233 len += ssh1_bignum_length(s->key.modulus);
4234 len += ssh1_bignum_length(s->challenge);
4235 len += 16; /* session id */
4236 len += 4; /* response format */
4237 agentreq = snewn(4 + len, char);
4238 PUT_32BIT(agentreq, len);
4240 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
4241 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
4243 q += ssh1_write_bignum(q, s->key.exponent);
4244 q += ssh1_write_bignum(q, s->key.modulus);
4245 q += ssh1_write_bignum(q, s->challenge);
4246 memcpy(q, s->session_id, 16);
4248 PUT_32BIT(q, 1); /* response format */
4249 if (!agent_query(agentreq, len + 4, &vret, &retlen,
4250 ssh_agent_callback, ssh)) {
4255 bombout(("Unexpected data from server"
4256 " while waiting for agent"
4260 } while (pktin || inlen > 0);
4261 vret = ssh->agent_response;
4262 retlen = ssh->agent_response_len;
4267 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
4268 logevent("Sending Pageant's response");
4269 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4270 PKT_DATA, ret + 5, 16,
4274 if (pktin->type == SSH1_SMSG_SUCCESS) {
4276 ("Pageant's response accepted");
4277 if (flags & FLAG_VERBOSE) {
4278 c_write_str(ssh, "Authenticated using"
4280 c_write(ssh, s->commentp,
4282 c_write_str(ssh, "\" from agent\r\n");
4287 ("Pageant's response not accepted");
4290 ("Pageant failed to answer challenge");
4294 logevent("No reply received from Pageant");
4297 freebn(s->key.exponent);
4298 freebn(s->key.modulus);
4299 freebn(s->challenge);
4304 if (s->publickey_blob && !s->tried_publickey)
4305 logevent("Configured key file not in Pageant");
4307 logevent("Failed to get reply from Pageant");
4312 if (s->publickey_blob && !s->tried_publickey) {
4314 * Try public key authentication with the specified
4317 int got_passphrase; /* need not be kept over crReturn */
4318 if (flags & FLAG_VERBOSE)
4319 c_write_str(ssh, "Trying public key authentication.\r\n");
4320 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4321 logeventf(ssh, "Trying public key \"%s\"",
4322 filename_to_str(s->keyfile));
4323 s->tried_publickey = 1;
4324 got_passphrase = FALSE;
4325 while (!got_passphrase) {
4327 * Get a passphrase, if necessary.
4329 char *passphrase = NULL; /* only written after crReturn */
4331 if (!s->publickey_encrypted) {
4332 if (flags & FLAG_VERBOSE)
4333 c_write_str(ssh, "No passphrase required.\r\n");
4336 int ret; /* need not be kept over crReturn */
4337 s->cur_prompt = new_prompts(ssh->frontend);
4338 s->cur_prompt->to_server = FALSE;
4339 s->cur_prompt->name = dupstr("SSH key passphrase");
4340 add_prompt(s->cur_prompt,
4341 dupprintf("Passphrase for key \"%.100s\": ",
4342 s->publickey_comment), FALSE);
4343 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4346 crWaitUntil(!pktin);
4347 ret = get_userpass_input(s->cur_prompt, in, inlen);
4351 /* Failed to get a passphrase. Terminate. */
4352 free_prompts(s->cur_prompt);
4353 ssh_disconnect(ssh, NULL, "Unable to authenticate",
4357 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
4358 free_prompts(s->cur_prompt);
4361 * Try decrypting key with passphrase.
4363 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4364 ret = loadrsakey(s->keyfile, &s->key, passphrase,
4367 smemclr(passphrase, strlen(passphrase));
4371 /* Correct passphrase. */
4372 got_passphrase = TRUE;
4373 } else if (ret == 0) {
4374 c_write_str(ssh, "Couldn't load private key from ");
4375 c_write_str(ssh, filename_to_str(s->keyfile));
4376 c_write_str(ssh, " (");
4377 c_write_str(ssh, error);
4378 c_write_str(ssh, ").\r\n");
4379 got_passphrase = FALSE;
4380 break; /* go and try something else */
4381 } else if (ret == -1) {
4382 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
4383 got_passphrase = FALSE;
4386 assert(0 && "unexpected return from loadrsakey()");
4387 got_passphrase = FALSE; /* placate optimisers */
4391 if (got_passphrase) {
4394 * Send a public key attempt.
4396 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4397 PKT_BIGNUM, s->key.modulus, PKT_END);
4400 if (pktin->type == SSH1_SMSG_FAILURE) {
4401 c_write_str(ssh, "Server refused our public key.\r\n");
4402 continue; /* go and try something else */
4404 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4405 bombout(("Bizarre response to offer of public key"));
4411 unsigned char buffer[32];
4412 Bignum challenge, response;
4414 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4415 bombout(("Server's RSA challenge was badly formatted"));
4418 response = rsadecrypt(challenge, &s->key);
4419 freebn(s->key.private_exponent);/* burn the evidence */
4421 for (i = 0; i < 32; i++) {
4422 buffer[i] = bignum_byte(response, 31 - i);
4426 MD5Update(&md5c, buffer, 32);
4427 MD5Update(&md5c, s->session_id, 16);
4428 MD5Final(buffer, &md5c);
4430 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4431 PKT_DATA, buffer, 16, PKT_END);
4438 if (pktin->type == SSH1_SMSG_FAILURE) {
4439 if (flags & FLAG_VERBOSE)
4440 c_write_str(ssh, "Failed to authenticate with"
4441 " our public key.\r\n");
4442 continue; /* go and try something else */
4443 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4444 bombout(("Bizarre response to RSA authentication response"));
4448 break; /* we're through! */
4454 * Otherwise, try various forms of password-like authentication.
4456 s->cur_prompt = new_prompts(ssh->frontend);
4458 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4459 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
4460 !s->tis_auth_refused) {
4461 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
4462 logevent("Requested TIS authentication");
4463 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
4465 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
4466 logevent("TIS authentication declined");
4467 if (flags & FLAG_INTERACTIVE)
4468 c_write_str(ssh, "TIS authentication refused.\r\n");
4469 s->tis_auth_refused = 1;
4474 char *instr_suf, *prompt;
4476 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4478 bombout(("TIS challenge packet was badly formed"));
4481 logevent("Received TIS challenge");
4482 s->cur_prompt->to_server = TRUE;
4483 s->cur_prompt->name = dupstr("SSH TIS authentication");
4484 /* Prompt heuristic comes from OpenSSH */
4485 if (memchr(challenge, '\n', challengelen)) {
4486 instr_suf = dupstr("");
4487 prompt = dupprintf("%.*s", challengelen, challenge);
4489 instr_suf = dupprintf("%.*s", challengelen, challenge);
4490 prompt = dupstr("Response: ");
4492 s->cur_prompt->instruction =
4493 dupprintf("Using TIS authentication.%s%s",
4494 (*instr_suf) ? "\n" : "",
4496 s->cur_prompt->instr_reqd = TRUE;
4497 add_prompt(s->cur_prompt, prompt, FALSE);
4501 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4502 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
4503 !s->ccard_auth_refused) {
4504 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
4505 logevent("Requested CryptoCard authentication");
4506 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
4508 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
4509 logevent("CryptoCard authentication declined");
4510 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4511 s->ccard_auth_refused = 1;
4516 char *instr_suf, *prompt;
4518 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4520 bombout(("CryptoCard challenge packet was badly formed"));
4523 logevent("Received CryptoCard challenge");
4524 s->cur_prompt->to_server = TRUE;
4525 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4526 s->cur_prompt->name_reqd = FALSE;
4527 /* Prompt heuristic comes from OpenSSH */
4528 if (memchr(challenge, '\n', challengelen)) {
4529 instr_suf = dupstr("");
4530 prompt = dupprintf("%.*s", challengelen, challenge);
4532 instr_suf = dupprintf("%.*s", challengelen, challenge);
4533 prompt = dupstr("Response: ");
4535 s->cur_prompt->instruction =
4536 dupprintf("Using CryptoCard authentication.%s%s",
4537 (*instr_suf) ? "\n" : "",
4539 s->cur_prompt->instr_reqd = TRUE;
4540 add_prompt(s->cur_prompt, prompt, FALSE);
4544 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4545 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4546 bombout(("No supported authentication methods available"));
4549 s->cur_prompt->to_server = TRUE;
4550 s->cur_prompt->name = dupstr("SSH password");
4551 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4552 ssh->username, ssh->savedhost),
4557 * Show password prompt, having first obtained it via a TIS
4558 * or CryptoCard exchange if we're doing TIS or CryptoCard
4562 int ret; /* need not be kept over crReturn */
4563 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4566 crWaitUntil(!pktin);
4567 ret = get_userpass_input(s->cur_prompt, in, inlen);
4572 * Failed to get a password (for example
4573 * because one was supplied on the command line
4574 * which has already failed to work). Terminate.
4576 free_prompts(s->cur_prompt);
4577 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4582 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4584 * Defence against traffic analysis: we send a
4585 * whole bunch of packets containing strings of
4586 * different lengths. One of these strings is the
4587 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4588 * The others are all random data in
4589 * SSH1_MSG_IGNORE packets. This way a passive
4590 * listener can't tell which is the password, and
4591 * hence can't deduce the password length.
4593 * Anybody with a password length greater than 16
4594 * bytes is going to have enough entropy in their
4595 * password that a listener won't find it _that_
4596 * much help to know how long it is. So what we'll
4599 * - if password length < 16, we send 15 packets
4600 * containing string lengths 1 through 15
4602 * - otherwise, we let N be the nearest multiple
4603 * of 8 below the password length, and send 8
4604 * packets containing string lengths N through
4605 * N+7. This won't obscure the order of
4606 * magnitude of the password length, but it will
4607 * introduce a bit of extra uncertainty.
4609 * A few servers can't deal with SSH1_MSG_IGNORE, at
4610 * least in this context. For these servers, we need
4611 * an alternative defence. We make use of the fact
4612 * that the password is interpreted as a C string:
4613 * so we can append a NUL, then some random data.
4615 * A few servers can deal with neither SSH1_MSG_IGNORE
4616 * here _nor_ a padded password string.
4617 * For these servers we are left with no defences
4618 * against password length sniffing.
4620 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4621 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4623 * The server can deal with SSH1_MSG_IGNORE, so
4624 * we can use the primary defence.
4626 int bottom, top, pwlen, i;
4629 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4631 bottom = 0; /* zero length passwords are OK! :-) */
4634 bottom = pwlen & ~7;
4638 assert(pwlen >= bottom && pwlen <= top);
4640 randomstr = snewn(top + 1, char);
4642 for (i = bottom; i <= top; i++) {
4644 defer_packet(ssh, s->pwpkt_type,
4645 PKT_STR,s->cur_prompt->prompts[0]->result,
4648 for (j = 0; j < i; j++) {
4650 randomstr[j] = random_byte();
4651 } while (randomstr[j] == '\0');
4653 randomstr[i] = '\0';
4654 defer_packet(ssh, SSH1_MSG_IGNORE,
4655 PKT_STR, randomstr, PKT_END);
4658 logevent("Sending password with camouflage packets");
4659 ssh_pkt_defersend(ssh);
4662 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4664 * The server can't deal with SSH1_MSG_IGNORE
4665 * but can deal with padded passwords, so we
4666 * can use the secondary defence.
4672 len = strlen(s->cur_prompt->prompts[0]->result);
4673 if (len < sizeof(string)) {
4675 strcpy(string, s->cur_prompt->prompts[0]->result);
4676 len++; /* cover the zero byte */
4677 while (len < sizeof(string)) {
4678 string[len++] = (char) random_byte();
4681 ss = s->cur_prompt->prompts[0]->result;
4683 logevent("Sending length-padded password");
4684 send_packet(ssh, s->pwpkt_type,
4685 PKT_INT, len, PKT_DATA, ss, len,
4689 * The server is believed unable to cope with
4690 * any of our password camouflage methods.
4693 len = strlen(s->cur_prompt->prompts[0]->result);
4694 logevent("Sending unpadded password");
4695 send_packet(ssh, s->pwpkt_type,
4697 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4701 send_packet(ssh, s->pwpkt_type,
4702 PKT_STR, s->cur_prompt->prompts[0]->result,
4705 logevent("Sent password");
4706 free_prompts(s->cur_prompt);
4708 if (pktin->type == SSH1_SMSG_FAILURE) {
4709 if (flags & FLAG_VERBOSE)
4710 c_write_str(ssh, "Access denied\r\n");
4711 logevent("Authentication refused");
4712 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4713 bombout(("Strange packet received, type %d", pktin->type));
4719 if (s->publickey_blob) {
4720 sfree(s->publickey_blob);
4721 sfree(s->publickey_comment);
4724 logevent("Authentication successful");
4729 static void ssh_channel_try_eof(struct ssh_channel *c)
4732 assert(c->pending_eof); /* precondition for calling us */
4734 return; /* can't close: not even opened yet */
4735 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4736 return; /* can't send EOF: pending outgoing data */
4738 c->pending_eof = FALSE; /* we're about to send it */
4739 if (ssh->version == 1) {
4740 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4742 c->closes |= CLOSES_SENT_EOF;
4744 struct Packet *pktout;
4745 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4746 ssh2_pkt_adduint32(pktout, c->remoteid);
4747 ssh2_pkt_send(ssh, pktout);
4748 c->closes |= CLOSES_SENT_EOF;
4749 ssh2_channel_check_close(c);
4753 Conf *sshfwd_get_conf(struct ssh_channel *c)
4759 void sshfwd_write_eof(struct ssh_channel *c)
4763 if (ssh->state == SSH_STATE_CLOSED)
4766 if (c->closes & CLOSES_SENT_EOF)
4769 c->pending_eof = TRUE;
4770 ssh_channel_try_eof(c);
4773 void sshfwd_unclean_close(struct ssh_channel *c, const char *err)
4777 if (ssh->state == SSH_STATE_CLOSED)
4782 x11_close(c->u.x11.xconn);
4783 logeventf(ssh, "Forwarded X11 connection terminated due to local "
4787 case CHAN_SOCKDATA_DORMANT:
4788 pfd_close(c->u.pfd.pf);
4789 logeventf(ssh, "Forwarded port closed due to local error: %s", err);
4792 c->type = CHAN_ZOMBIE;
4793 c->pending_eof = FALSE; /* this will confuse a zombie channel */
4795 ssh2_channel_check_close(c);
4798 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
4802 if (ssh->state == SSH_STATE_CLOSED)
4805 if (ssh->version == 1) {
4806 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
4807 PKT_INT, c->remoteid,
4808 PKT_INT, len, PKT_DATA, buf, len,
4811 * In SSH-1 we can return 0 here - implying that forwarded
4812 * connections are never individually throttled - because
4813 * the only circumstance that can cause throttling will be
4814 * the whole SSH connection backing up, in which case
4815 * _everything_ will be throttled as a whole.
4819 ssh2_add_channel_data(c, buf, len);
4820 return ssh2_try_send(c);
4824 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4829 if (ssh->state == SSH_STATE_CLOSED)
4832 if (ssh->version == 1) {
4833 buflimit = SSH1_BUFFER_LIMIT;
4835 buflimit = c->v.v2.locmaxwin;
4836 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
4838 if (c->throttling_conn && bufsize <= buflimit) {
4839 c->throttling_conn = 0;
4840 ssh_throttle_conn(ssh, -1);
4844 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
4846 struct queued_handler *qh = ssh->qhead;
4850 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
4853 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
4854 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
4857 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
4858 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
4862 ssh->qhead = qh->next;
4864 if (ssh->qhead->msg1 > 0) {
4865 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4866 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
4868 if (ssh->qhead->msg2 > 0) {
4869 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4870 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
4873 ssh->qhead = ssh->qtail = NULL;
4876 qh->handler(ssh, pktin, qh->ctx);
4881 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
4882 chandler_fn_t handler, void *ctx)
4884 struct queued_handler *qh;
4886 qh = snew(struct queued_handler);
4889 qh->handler = handler;
4893 if (ssh->qtail == NULL) {
4897 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4898 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
4901 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4902 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
4905 ssh->qtail->next = qh;
4910 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
4912 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
4914 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
4915 SSH2_MSG_REQUEST_SUCCESS)) {
4916 logeventf(ssh, "Remote port forwarding from %s enabled",
4919 logeventf(ssh, "Remote port forwarding from %s refused",
4922 rpf = del234(ssh->rportfwds, pf);
4924 pf->pfrec->remote = NULL;
4929 int ssh_alloc_sharing_rportfwd(Ssh ssh, const char *shost, int sport,
4932 struct ssh_rportfwd *pf = snew(struct ssh_rportfwd);
4935 pf->share_ctx = share_ctx;
4936 pf->shost = dupstr(shost);
4938 pf->sportdesc = NULL;
4939 if (!ssh->rportfwds) {
4940 assert(ssh->version == 2);
4941 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4943 if (add234(ssh->rportfwds, pf) != pf) {
4951 static void ssh_sharing_global_request_response(Ssh ssh, struct Packet *pktin,
4954 share_got_pkt_from_server(ctx, pktin->type,
4955 pktin->body, pktin->length);
4958 void ssh_sharing_queue_global_request(Ssh ssh, void *share_ctx)
4960 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, SSH2_MSG_REQUEST_FAILURE,
4961 ssh_sharing_global_request_response, share_ctx);
4964 static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
4966 struct ssh_portfwd *epf;
4970 if (!ssh->portfwds) {
4971 ssh->portfwds = newtree234(ssh_portcmp);
4974 * Go through the existing port forwardings and tag them
4975 * with status==DESTROY. Any that we want to keep will be
4976 * re-enabled (status==KEEP) as we go through the
4977 * configuration and find out which bits are the same as
4980 struct ssh_portfwd *epf;
4982 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4983 epf->status = DESTROY;
4986 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
4988 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
4989 char *kp, *kp2, *vp, *vp2;
4990 char address_family, type;
4991 int sport,dport,sserv,dserv;
4992 char *sports, *dports, *saddr, *host;
4996 address_family = 'A';
4998 if (*kp == 'A' || *kp == '4' || *kp == '6')
4999 address_family = *kp++;
5000 if (*kp == 'L' || *kp == 'R')
5003 if ((kp2 = host_strchr(kp, ':')) != NULL) {
5005 * There's a colon in the middle of the source port
5006 * string, which means that the part before it is
5007 * actually a source address.
5009 char *saddr_tmp = dupprintf("%.*s", (int)(kp2 - kp), kp);
5010 saddr = host_strduptrim(saddr_tmp);
5017 sport = atoi(sports);
5021 sport = net_service_lookup(sports);
5023 logeventf(ssh, "Service lookup failed for source"
5024 " port \"%s\"", sports);
5028 if (type == 'L' && !strcmp(val, "D")) {
5029 /* dynamic forwarding */
5036 /* ordinary forwarding */
5038 vp2 = vp + host_strcspn(vp, ":");
5039 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
5043 dport = atoi(dports);
5047 dport = net_service_lookup(dports);
5049 logeventf(ssh, "Service lookup failed for destination"
5050 " port \"%s\"", dports);
5055 if (sport && dport) {
5056 /* Set up a description of the source port. */
5057 struct ssh_portfwd *pfrec, *epfrec;
5059 pfrec = snew(struct ssh_portfwd);
5061 pfrec->saddr = saddr;
5062 pfrec->sserv = sserv ? dupstr(sports) : NULL;
5063 pfrec->sport = sport;
5064 pfrec->daddr = host;
5065 pfrec->dserv = dserv ? dupstr(dports) : NULL;
5066 pfrec->dport = dport;
5067 pfrec->local = NULL;
5068 pfrec->remote = NULL;
5069 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
5070 address_family == '6' ? ADDRTYPE_IPV6 :
5073 epfrec = add234(ssh->portfwds, pfrec);
5074 if (epfrec != pfrec) {
5075 if (epfrec->status == DESTROY) {
5077 * We already have a port forwarding up and running
5078 * with precisely these parameters. Hence, no need
5079 * to do anything; simply re-tag the existing one
5082 epfrec->status = KEEP;
5085 * Anything else indicates that there was a duplicate
5086 * in our input, which we'll silently ignore.
5088 free_portfwd(pfrec);
5090 pfrec->status = CREATE;
5099 * Now go through and destroy any port forwardings which were
5102 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5103 if (epf->status == DESTROY) {
5106 message = dupprintf("%s port forwarding from %s%s%d",
5107 epf->type == 'L' ? "local" :
5108 epf->type == 'R' ? "remote" : "dynamic",
5109 epf->saddr ? epf->saddr : "",
5110 epf->saddr ? ":" : "",
5113 if (epf->type != 'D') {
5114 char *msg2 = dupprintf("%s to %s:%d", message,
5115 epf->daddr, epf->dport);
5120 logeventf(ssh, "Cancelling %s", message);
5123 /* epf->remote or epf->local may be NULL if setting up a
5124 * forwarding failed. */
5126 struct ssh_rportfwd *rpf = epf->remote;
5127 struct Packet *pktout;
5130 * Cancel the port forwarding at the server
5133 if (ssh->version == 1) {
5135 * We cannot cancel listening ports on the
5136 * server side in SSH-1! There's no message
5137 * to support it. Instead, we simply remove
5138 * the rportfwd record from the local end
5139 * so that any connections the server tries
5140 * to make on it are rejected.
5143 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5144 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
5145 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
5147 ssh2_pkt_addstring(pktout, epf->saddr);
5148 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5149 /* XXX: rport_acceptall may not represent
5150 * what was used to open the original connection,
5151 * since it's reconfigurable. */
5152 ssh2_pkt_addstring(pktout, "");
5154 ssh2_pkt_addstring(pktout, "localhost");
5156 ssh2_pkt_adduint32(pktout, epf->sport);
5157 ssh2_pkt_send(ssh, pktout);
5160 del234(ssh->rportfwds, rpf);
5162 } else if (epf->local) {
5163 pfl_terminate(epf->local);
5166 delpos234(ssh->portfwds, i);
5168 i--; /* so we don't skip one in the list */
5172 * And finally, set up any new port forwardings (status==CREATE).
5174 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5175 if (epf->status == CREATE) {
5176 char *sportdesc, *dportdesc;
5177 sportdesc = dupprintf("%s%s%s%s%d%s",
5178 epf->saddr ? epf->saddr : "",
5179 epf->saddr ? ":" : "",
5180 epf->sserv ? epf->sserv : "",
5181 epf->sserv ? "(" : "",
5183 epf->sserv ? ")" : "");
5184 if (epf->type == 'D') {
5187 dportdesc = dupprintf("%s:%s%s%d%s",
5189 epf->dserv ? epf->dserv : "",
5190 epf->dserv ? "(" : "",
5192 epf->dserv ? ")" : "");
5195 if (epf->type == 'L') {
5196 char *err = pfl_listen(epf->daddr, epf->dport,
5197 epf->saddr, epf->sport,
5198 ssh, conf, &epf->local,
5199 epf->addressfamily);
5201 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
5202 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5203 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5204 sportdesc, dportdesc,
5205 err ? " failed: " : "", err ? err : "");
5208 } else if (epf->type == 'D') {
5209 char *err = pfl_listen(NULL, -1, epf->saddr, epf->sport,
5210 ssh, conf, &epf->local,
5211 epf->addressfamily);
5213 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
5214 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5215 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5217 err ? " failed: " : "", err ? err : "");
5222 struct ssh_rportfwd *pf;
5225 * Ensure the remote port forwardings tree exists.
5227 if (!ssh->rportfwds) {
5228 if (ssh->version == 1)
5229 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
5231 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5234 pf = snew(struct ssh_rportfwd);
5235 pf->share_ctx = NULL;
5236 pf->dhost = dupstr(epf->daddr);
5237 pf->dport = epf->dport;
5239 pf->shost = dupstr(epf->saddr);
5240 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5241 pf->shost = dupstr("");
5243 pf->shost = dupstr("localhost");
5245 pf->sport = epf->sport;
5246 if (add234(ssh->rportfwds, pf) != pf) {
5247 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
5248 epf->daddr, epf->dport);
5251 logeventf(ssh, "Requesting remote port %s"
5252 " forward to %s", sportdesc, dportdesc);
5254 pf->sportdesc = sportdesc;
5259 if (ssh->version == 1) {
5260 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
5261 PKT_INT, epf->sport,
5262 PKT_STR, epf->daddr,
5263 PKT_INT, epf->dport,
5265 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
5267 ssh_rportfwd_succfail, pf);
5269 struct Packet *pktout;
5270 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5271 ssh2_pkt_addstring(pktout, "tcpip-forward");
5272 ssh2_pkt_addbool(pktout, 1);/* want reply */
5273 ssh2_pkt_addstring(pktout, pf->shost);
5274 ssh2_pkt_adduint32(pktout, pf->sport);
5275 ssh2_pkt_send(ssh, pktout);
5277 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
5278 SSH2_MSG_REQUEST_FAILURE,
5279 ssh_rportfwd_succfail, pf);
5288 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
5291 int stringlen, bufsize;
5293 ssh_pkt_getstring(pktin, &string, &stringlen);
5294 if (string == NULL) {
5295 bombout(("Incoming terminal data packet was badly formed"));
5299 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
5301 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
5302 ssh->v1_stdout_throttling = 1;
5303 ssh_throttle_conn(ssh, +1);
5307 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
5309 /* Remote side is trying to open a channel to talk to our
5310 * X-Server. Give them back a local channel number. */
5311 struct ssh_channel *c;
5312 int remoteid = ssh_pkt_getuint32(pktin);
5314 logevent("Received X11 connect request");
5315 /* Refuse if X11 forwarding is disabled. */
5316 if (!ssh->X11_fwd_enabled) {
5317 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5318 PKT_INT, remoteid, PKT_END);
5319 logevent("Rejected X11 connect request");
5321 c = snew(struct ssh_channel);
5324 c->u.x11.xconn = x11_init(ssh->x11authtree, c, NULL, -1);
5325 c->remoteid = remoteid;
5326 c->halfopen = FALSE;
5327 c->localid = alloc_channel_id(ssh);
5329 c->pending_eof = FALSE;
5330 c->throttling_conn = 0;
5331 c->type = CHAN_X11; /* identify channel type */
5332 add234(ssh->channels, c);
5333 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5334 PKT_INT, c->remoteid, PKT_INT,
5335 c->localid, PKT_END);
5336 logevent("Opened X11 forward channel");
5340 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
5342 /* Remote side is trying to open a channel to talk to our
5343 * agent. Give them back a local channel number. */
5344 struct ssh_channel *c;
5345 int remoteid = ssh_pkt_getuint32(pktin);
5347 /* Refuse if agent forwarding is disabled. */
5348 if (!ssh->agentfwd_enabled) {
5349 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5350 PKT_INT, remoteid, PKT_END);
5352 c = snew(struct ssh_channel);
5354 c->remoteid = remoteid;
5355 c->halfopen = FALSE;
5356 c->localid = alloc_channel_id(ssh);
5358 c->pending_eof = FALSE;
5359 c->throttling_conn = 0;
5360 c->type = CHAN_AGENT; /* identify channel type */
5361 c->u.a.lensofar = 0;
5362 c->u.a.message = NULL;
5363 c->u.a.outstanding_requests = 0;
5364 add234(ssh->channels, c);
5365 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5366 PKT_INT, c->remoteid, PKT_INT, c->localid,
5371 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
5373 /* Remote side is trying to open a channel to talk to a
5374 * forwarded port. Give them back a local channel number. */
5375 struct ssh_rportfwd pf, *pfp;
5381 remoteid = ssh_pkt_getuint32(pktin);
5382 ssh_pkt_getstring(pktin, &host, &hostsize);
5383 port = ssh_pkt_getuint32(pktin);
5385 pf.dhost = dupprintf("%.*s", hostsize, host);
5387 pfp = find234(ssh->rportfwds, &pf, NULL);
5390 logeventf(ssh, "Rejected remote port open request for %s:%d",
5392 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5393 PKT_INT, remoteid, PKT_END);
5395 struct ssh_channel *c = snew(struct ssh_channel);
5398 logeventf(ssh, "Received remote port open request for %s:%d",
5400 err = pfd_connect(&c->u.pfd.pf, pf.dhost, port,
5401 c, ssh->conf, pfp->pfrec->addressfamily);
5403 logeventf(ssh, "Port open failed: %s", err);
5406 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5407 PKT_INT, remoteid, PKT_END);
5409 c->remoteid = remoteid;
5410 c->halfopen = FALSE;
5411 c->localid = alloc_channel_id(ssh);
5413 c->pending_eof = FALSE;
5414 c->throttling_conn = 0;
5415 c->type = CHAN_SOCKDATA; /* identify channel type */
5416 add234(ssh->channels, c);
5417 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5418 PKT_INT, c->remoteid, PKT_INT,
5419 c->localid, PKT_END);
5420 logevent("Forwarded port opened successfully");
5427 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5429 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5430 unsigned int localid = ssh_pkt_getuint32(pktin);
5431 struct ssh_channel *c;
5433 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5434 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5435 c->remoteid = localid;
5436 c->halfopen = FALSE;
5437 c->type = CHAN_SOCKDATA;
5438 c->throttling_conn = 0;
5439 pfd_confirm(c->u.pfd.pf);
5442 if (c && c->pending_eof) {
5444 * We have a pending close on this channel,
5445 * which we decided on before the server acked
5446 * the channel open. So now we know the
5447 * remoteid, we can close it again.
5449 ssh_channel_try_eof(c);
5453 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5455 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5456 struct ssh_channel *c;
5458 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5459 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5460 logevent("Forwarded connection refused by server");
5461 pfd_close(c->u.pfd.pf);
5462 del234(ssh->channels, c);
5467 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
5469 /* Remote side closes a channel. */
5470 unsigned i = ssh_pkt_getuint32(pktin);
5471 struct ssh_channel *c;
5472 c = find234(ssh->channels, &i, ssh_channelfind);
5473 if (c && !c->halfopen) {
5475 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
5476 !(c->closes & CLOSES_RCVD_EOF)) {
5478 * Received CHANNEL_CLOSE, which we translate into
5481 int send_close = FALSE;
5483 c->closes |= CLOSES_RCVD_EOF;
5488 x11_send_eof(c->u.x11.xconn);
5494 pfd_send_eof(c->u.pfd.pf);
5503 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
5504 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
5506 c->closes |= CLOSES_SENT_EOF;
5510 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
5511 !(c->closes & CLOSES_RCVD_CLOSE)) {
5513 if (!(c->closes & CLOSES_SENT_EOF)) {
5514 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
5515 " for which we never sent CHANNEL_CLOSE\n", i));
5518 c->closes |= CLOSES_RCVD_CLOSE;
5521 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
5522 !(c->closes & CLOSES_SENT_CLOSE)) {
5523 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
5524 PKT_INT, c->remoteid, PKT_END);
5525 c->closes |= CLOSES_SENT_CLOSE;
5528 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5529 ssh_channel_destroy(c);
5531 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5532 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
5533 "_CONFIRMATION", c ? "half-open" : "nonexistent",
5538 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5540 /* Data sent down one of our channels. */
5541 int i = ssh_pkt_getuint32(pktin);
5544 struct ssh_channel *c;
5546 ssh_pkt_getstring(pktin, &p, &len);
5548 c = find234(ssh->channels, &i, ssh_channelfind);
5553 bufsize = x11_send(c->u.x11.xconn, p, len);
5556 bufsize = pfd_send(c->u.pfd.pf, p, len);
5559 /* Data for an agent message. Buffer it. */
5561 if (c->u.a.lensofar < 4) {
5562 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
5563 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
5567 c->u.a.lensofar += l;
5569 if (c->u.a.lensofar == 4) {
5571 4 + GET_32BIT(c->u.a.msglen);
5572 c->u.a.message = snewn(c->u.a.totallen,
5574 memcpy(c->u.a.message, c->u.a.msglen, 4);
5576 if (c->u.a.lensofar >= 4 && len > 0) {
5578 min(c->u.a.totallen - c->u.a.lensofar,
5580 memcpy(c->u.a.message + c->u.a.lensofar, p,
5584 c->u.a.lensofar += l;
5586 if (c->u.a.lensofar == c->u.a.totallen) {
5589 c->u.a.outstanding_requests++;
5590 if (agent_query(c->u.a.message,
5593 ssh_agentf_callback, c))
5594 ssh_agentf_callback(c, reply, replylen);
5595 sfree(c->u.a.message);
5596 c->u.a.lensofar = 0;
5599 bufsize = 0; /* agent channels never back up */
5602 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5603 c->throttling_conn = 1;
5604 ssh_throttle_conn(ssh, +1);
5609 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5611 ssh->exitcode = ssh_pkt_getuint32(pktin);
5612 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5613 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5615 * In case `helpful' firewalls or proxies tack
5616 * extra human-readable text on the end of the
5617 * session which we might mistake for another
5618 * encrypted packet, we close the session once
5619 * we've sent EXIT_CONFIRMATION.
5621 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5624 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5625 static void ssh1_send_ttymode(void *data, char *mode, char *val)
5627 struct Packet *pktout = (struct Packet *)data;
5629 unsigned int arg = 0;
5630 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5631 if (i == lenof(ssh_ttymodes)) return;
5632 switch (ssh_ttymodes[i].type) {
5634 arg = ssh_tty_parse_specchar(val);
5637 arg = ssh_tty_parse_boolean(val);
5640 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5641 ssh2_pkt_addbyte(pktout, arg);
5644 int ssh_agent_forwarding_permitted(Ssh ssh)
5646 return conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists();
5649 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
5650 struct Packet *pktin)
5652 crBegin(ssh->do_ssh1_connection_crstate);
5654 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5655 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5656 ssh1_smsg_stdout_stderr_data;
5658 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5659 ssh1_msg_channel_open_confirmation;
5660 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5661 ssh1_msg_channel_open_failure;
5662 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5663 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5664 ssh1_msg_channel_close;
5665 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5666 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5668 if (ssh_agent_forwarding_permitted(ssh)) {
5669 logevent("Requesting agent forwarding");
5670 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5674 if (pktin->type != SSH1_SMSG_SUCCESS
5675 && pktin->type != SSH1_SMSG_FAILURE) {
5676 bombout(("Protocol confusion"));
5678 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5679 logevent("Agent forwarding refused");
5681 logevent("Agent forwarding enabled");
5682 ssh->agentfwd_enabled = TRUE;
5683 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5687 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
5689 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5691 if (!ssh->x11disp) {
5692 /* FIXME: return an error message from x11_setup_display */
5693 logevent("X11 forwarding not enabled: unable to"
5694 " initialise X display");
5696 ssh->x11auth = x11_invent_fake_auth
5697 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
5698 ssh->x11auth->disp = ssh->x11disp;
5700 logevent("Requesting X11 forwarding");
5701 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5702 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5703 PKT_STR, ssh->x11auth->protoname,
5704 PKT_STR, ssh->x11auth->datastring,
5705 PKT_INT, ssh->x11disp->screennum,
5708 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5709 PKT_STR, ssh->x11auth->protoname,
5710 PKT_STR, ssh->x11auth->datastring,
5716 if (pktin->type != SSH1_SMSG_SUCCESS
5717 && pktin->type != SSH1_SMSG_FAILURE) {
5718 bombout(("Protocol confusion"));
5720 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5721 logevent("X11 forwarding refused");
5723 logevent("X11 forwarding enabled");
5724 ssh->X11_fwd_enabled = TRUE;
5725 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5730 ssh_setup_portfwd(ssh, ssh->conf);
5731 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5733 if (!conf_get_int(ssh->conf, CONF_nopty)) {
5735 /* Unpick the terminal-speed string. */
5736 /* XXX perhaps we should allow no speeds to be sent. */
5737 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5738 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
5739 /* Send the pty request. */
5740 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5741 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
5742 ssh_pkt_adduint32(pkt, ssh->term_height);
5743 ssh_pkt_adduint32(pkt, ssh->term_width);
5744 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5745 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5746 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
5747 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5748 ssh_pkt_adduint32(pkt, ssh->ispeed);
5749 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5750 ssh_pkt_adduint32(pkt, ssh->ospeed);
5751 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5753 ssh->state = SSH_STATE_INTERMED;
5757 if (pktin->type != SSH1_SMSG_SUCCESS
5758 && pktin->type != SSH1_SMSG_FAILURE) {
5759 bombout(("Protocol confusion"));
5761 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5762 c_write_str(ssh, "Server refused to allocate pty\r\n");
5763 ssh->editing = ssh->echoing = 1;
5765 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5766 ssh->ospeed, ssh->ispeed);
5767 ssh->got_pty = TRUE;
5770 ssh->editing = ssh->echoing = 1;
5773 if (conf_get_int(ssh->conf, CONF_compression)) {
5774 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5778 if (pktin->type != SSH1_SMSG_SUCCESS
5779 && pktin->type != SSH1_SMSG_FAILURE) {
5780 bombout(("Protocol confusion"));
5782 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5783 c_write_str(ssh, "Server refused to compress\r\n");
5785 logevent("Started compression");
5786 ssh->v1_compressing = TRUE;
5787 ssh->cs_comp_ctx = zlib_compress_init();
5788 logevent("Initialised zlib (RFC1950) compression");
5789 ssh->sc_comp_ctx = zlib_decompress_init();
5790 logevent("Initialised zlib (RFC1950) decompression");
5794 * Start the shell or command.
5796 * Special case: if the first-choice command is an SSH-2
5797 * subsystem (hence not usable here) and the second choice
5798 * exists, we fall straight back to that.
5801 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
5803 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
5804 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
5805 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
5806 ssh->fallback_cmd = TRUE;
5809 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
5811 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
5812 logevent("Started session");
5815 ssh->state = SSH_STATE_SESSION;
5816 if (ssh->size_needed)
5817 ssh_size(ssh, ssh->term_width, ssh->term_height);
5818 if (ssh->eof_needed)
5819 ssh_special(ssh, TS_EOF);
5822 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5824 ssh->channels = newtree234(ssh_channelcmp);
5828 * By this point, most incoming packets are already being
5829 * handled by the dispatch table, and we need only pay
5830 * attention to the unusual ones.
5835 if (pktin->type == SSH1_SMSG_SUCCESS) {
5836 /* may be from EXEC_SHELL on some servers */
5837 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5838 /* may be from EXEC_SHELL on some servers
5839 * if no pty is available or in other odd cases. Ignore */
5841 bombout(("Strange packet received: type %d", pktin->type));
5846 int len = min(inlen, 512);
5847 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
5848 PKT_INT, len, PKT_DATA, in, len,
5860 * Handle the top-level SSH-2 protocol.
5862 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
5867 ssh_pkt_getstring(pktin, &msg, &msglen);
5868 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
5871 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
5873 /* log reason code in disconnect message */
5877 ssh_pkt_getstring(pktin, &msg, &msglen);
5878 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
5881 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
5883 /* Do nothing, because we're ignoring it! Duhh. */
5886 static void ssh1_protocol_setup(Ssh ssh)
5891 * Most messages are handled by the coroutines.
5893 for (i = 0; i < 256; i++)
5894 ssh->packet_dispatch[i] = NULL;
5897 * These special message types we install handlers for.
5899 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
5900 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
5901 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
5904 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
5905 struct Packet *pktin)
5907 unsigned char *in=(unsigned char*)vin;
5908 if (ssh->state == SSH_STATE_CLOSED)
5911 if (pktin && ssh->packet_dispatch[pktin->type]) {
5912 ssh->packet_dispatch[pktin->type](ssh, pktin);
5916 if (!ssh->protocol_initial_phase_done) {
5917 if (do_ssh1_login(ssh, in, inlen, pktin))
5918 ssh->protocol_initial_phase_done = TRUE;
5923 do_ssh1_connection(ssh, in, inlen, pktin);
5927 * Utility routine for decoding comma-separated strings in KEXINIT.
5929 static int in_commasep_string(char *needle, char *haystack, int haylen)
5932 if (!needle || !haystack) /* protect against null pointers */
5934 needlen = strlen(needle);
5937 * Is it at the start of the string?
5939 if (haylen >= needlen && /* haystack is long enough */
5940 !memcmp(needle, haystack, needlen) && /* initial match */
5941 (haylen == needlen || haystack[needlen] == ',')
5942 /* either , or EOS follows */
5946 * If not, search for the next comma and resume after that.
5947 * If no comma found, terminate.
5949 while (haylen > 0 && *haystack != ',')
5950 haylen--, haystack++;
5953 haylen--, haystack++; /* skip over comma itself */
5958 * Similar routine for checking whether we have the first string in a list.
5960 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
5963 if (!needle || !haystack) /* protect against null pointers */
5965 needlen = strlen(needle);
5967 * Is it at the start of the string?
5969 if (haylen >= needlen && /* haystack is long enough */
5970 !memcmp(needle, haystack, needlen) && /* initial match */
5971 (haylen == needlen || haystack[needlen] == ',')
5972 /* either , or EOS follows */
5980 * SSH-2 key creation method.
5981 * (Currently assumes 2 lots of any hash are sufficient to generate
5982 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
5984 #define SSH2_MKKEY_ITERS (2)
5985 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
5986 unsigned char *keyspace)
5988 const struct ssh_hash *h = ssh->kex->hash;
5990 /* First hlen bytes. */
5992 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5993 hash_mpint(h, s, K);
5994 h->bytes(s, H, h->hlen);
5995 h->bytes(s, &chr, 1);
5996 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
5997 h->final(s, keyspace);
5998 /* Next hlen bytes. */
6000 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6001 hash_mpint(h, s, K);
6002 h->bytes(s, H, h->hlen);
6003 h->bytes(s, keyspace, h->hlen);
6004 h->final(s, keyspace + h->hlen);
6008 * Handle the SSH-2 transport layer.
6010 static void do_ssh2_transport(Ssh ssh, void *vin, int inlen,
6011 struct Packet *pktin)
6013 unsigned char *in = (unsigned char *)vin;
6014 struct do_ssh2_transport_state {
6016 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
6017 Bignum p, g, e, f, K;
6020 int kex_init_value, kex_reply_value;
6021 const struct ssh_mac **maclist;
6023 const struct ssh2_cipher *cscipher_tobe;
6024 const struct ssh2_cipher *sccipher_tobe;
6025 const struct ssh_mac *csmac_tobe;
6026 const struct ssh_mac *scmac_tobe;
6027 const struct ssh_compress *cscomp_tobe;
6028 const struct ssh_compress *sccomp_tobe;
6029 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
6030 int hostkeylen, siglen, rsakeylen;
6031 void *hkey; /* actual host key */
6032 void *rsakey; /* for RSA kex */
6033 void *eckey; /* for ECDH kex */
6034 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
6035 int n_preferred_kex;
6036 const struct ssh_kexes *preferred_kex[KEX_MAX];
6037 int n_preferred_ciphers;
6038 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
6039 const struct ssh_compress *preferred_comp;
6040 int userauth_succeeded; /* for delayed compression */
6041 int pending_compression;
6042 int got_session_id, activated_authconn;
6043 struct Packet *pktout;
6048 crState(do_ssh2_transport_state);
6050 assert(!ssh->bare_connection);
6054 s->cscipher_tobe = s->sccipher_tobe = NULL;
6055 s->csmac_tobe = s->scmac_tobe = NULL;
6056 s->cscomp_tobe = s->sccomp_tobe = NULL;
6058 s->got_session_id = s->activated_authconn = FALSE;
6059 s->userauth_succeeded = FALSE;
6060 s->pending_compression = FALSE;
6063 * Be prepared to work around the buggy MAC problem.
6065 if (ssh->remote_bugs & BUG_SSH2_HMAC)
6066 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
6068 s->maclist = macs, s->nmacs = lenof(macs);
6071 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
6073 int i, j, k, commalist_started;
6076 * Set up the preferred key exchange. (NULL => warn below here)
6078 s->n_preferred_kex = 0;
6079 for (i = 0; i < KEX_MAX; i++) {
6080 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
6082 s->preferred_kex[s->n_preferred_kex++] =
6083 &ssh_diffiehellman_gex;
6086 s->preferred_kex[s->n_preferred_kex++] =
6087 &ssh_diffiehellman_group14;
6090 s->preferred_kex[s->n_preferred_kex++] =
6091 &ssh_diffiehellman_group1;
6094 s->preferred_kex[s->n_preferred_kex++] =
6098 s->preferred_kex[s->n_preferred_kex++] =
6102 /* Flag for later. Don't bother if it's the last in
6104 if (i < KEX_MAX - 1) {
6105 s->preferred_kex[s->n_preferred_kex++] = NULL;
6112 * Set up the preferred ciphers. (NULL => warn below here)
6114 s->n_preferred_ciphers = 0;
6115 for (i = 0; i < CIPHER_MAX; i++) {
6116 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
6117 case CIPHER_BLOWFISH:
6118 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
6121 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
6122 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
6126 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
6129 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
6131 case CIPHER_ARCFOUR:
6132 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
6135 /* Flag for later. Don't bother if it's the last in
6137 if (i < CIPHER_MAX - 1) {
6138 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
6145 * Set up preferred compression.
6147 if (conf_get_int(ssh->conf, CONF_compression))
6148 s->preferred_comp = &ssh_zlib;
6150 s->preferred_comp = &ssh_comp_none;
6153 * Enable queueing of outgoing auth- or connection-layer
6154 * packets while we are in the middle of a key exchange.
6156 ssh->queueing = TRUE;
6159 * Flag that KEX is in progress.
6161 ssh->kex_in_progress = TRUE;
6164 * Construct and send our key exchange packet.
6166 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
6167 for (i = 0; i < 16; i++)
6168 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
6169 /* List key exchange algorithms. */
6170 ssh2_pkt_addstring_start(s->pktout);
6171 commalist_started = 0;
6172 for (i = 0; i < s->n_preferred_kex; i++) {
6173 const struct ssh_kexes *k = s->preferred_kex[i];
6174 if (!k) continue; /* warning flag */
6175 for (j = 0; j < k->nkexes; j++) {
6176 if (commalist_started)
6177 ssh2_pkt_addstring_str(s->pktout, ",");
6178 ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
6179 commalist_started = 1;
6182 /* List server host key algorithms. */
6183 if (!s->got_session_id) {
6185 * In the first key exchange, we list all the algorithms
6186 * we're prepared to cope with.
6188 ssh2_pkt_addstring_start(s->pktout);
6189 for (i = 0; i < lenof(hostkey_algs); i++) {
6190 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
6191 if (i < lenof(hostkey_algs) - 1)
6192 ssh2_pkt_addstring_str(s->pktout, ",");
6196 * In subsequent key exchanges, we list only the kex
6197 * algorithm that was selected in the first key exchange,
6198 * so that we keep getting the same host key and hence
6199 * don't have to interrupt the user's session to ask for
6203 ssh2_pkt_addstring(s->pktout, ssh->hostkey->name);
6205 /* List encryption algorithms (client->server then server->client). */
6206 for (k = 0; k < 2; k++) {
6207 ssh2_pkt_addstring_start(s->pktout);
6208 commalist_started = 0;
6209 for (i = 0; i < s->n_preferred_ciphers; i++) {
6210 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6211 if (!c) continue; /* warning flag */
6212 for (j = 0; j < c->nciphers; j++) {
6213 if (commalist_started)
6214 ssh2_pkt_addstring_str(s->pktout, ",");
6215 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
6216 commalist_started = 1;
6220 /* List MAC algorithms (client->server then server->client). */
6221 for (j = 0; j < 2; j++) {
6222 ssh2_pkt_addstring_start(s->pktout);
6223 for (i = 0; i < s->nmacs; i++) {
6224 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
6225 if (i < s->nmacs - 1)
6226 ssh2_pkt_addstring_str(s->pktout, ",");
6229 /* List client->server compression algorithms,
6230 * then server->client compression algorithms. (We use the
6231 * same set twice.) */
6232 for (j = 0; j < 2; j++) {
6233 ssh2_pkt_addstring_start(s->pktout);
6234 assert(lenof(compressions) > 1);
6235 /* Prefer non-delayed versions */
6236 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
6237 /* We don't even list delayed versions of algorithms until
6238 * they're allowed to be used, to avoid a race. See the end of
6240 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
6241 ssh2_pkt_addstring_str(s->pktout, ",");
6242 ssh2_pkt_addstring_str(s->pktout,
6243 s->preferred_comp->delayed_name);
6245 for (i = 0; i < lenof(compressions); i++) {
6246 const struct ssh_compress *c = compressions[i];
6247 if (c != s->preferred_comp) {
6248 ssh2_pkt_addstring_str(s->pktout, ",");
6249 ssh2_pkt_addstring_str(s->pktout, c->name);
6250 if (s->userauth_succeeded && c->delayed_name) {
6251 ssh2_pkt_addstring_str(s->pktout, ",");
6252 ssh2_pkt_addstring_str(s->pktout, c->delayed_name);
6257 /* List client->server languages. Empty list. */
6258 ssh2_pkt_addstring_start(s->pktout);
6259 /* List server->client languages. Empty list. */
6260 ssh2_pkt_addstring_start(s->pktout);
6261 /* First KEX packet does _not_ follow, because we're not that brave. */
6262 ssh2_pkt_addbool(s->pktout, FALSE);
6264 ssh2_pkt_adduint32(s->pktout, 0);
6267 s->our_kexinitlen = s->pktout->length - 5;
6268 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
6269 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
6271 ssh2_pkt_send_noqueue(ssh, s->pktout);
6274 crWaitUntilV(pktin);
6277 * Now examine the other side's KEXINIT to see what we're up
6281 char *str, *preferred;
6284 if (pktin->type != SSH2_MSG_KEXINIT) {
6285 bombout(("expected key exchange packet from server"));
6289 ssh->hostkey = NULL;
6290 s->cscipher_tobe = NULL;
6291 s->sccipher_tobe = NULL;
6292 s->csmac_tobe = NULL;
6293 s->scmac_tobe = NULL;
6294 s->cscomp_tobe = NULL;
6295 s->sccomp_tobe = NULL;
6296 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
6298 pktin->savedpos += 16; /* skip garbage cookie */
6299 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
6301 bombout(("KEXINIT packet was incomplete"));
6306 for (i = 0; i < s->n_preferred_kex; i++) {
6307 const struct ssh_kexes *k = s->preferred_kex[i];
6311 for (j = 0; j < k->nkexes; j++) {
6312 if (!preferred) preferred = k->list[j]->name;
6313 if (in_commasep_string(k->list[j]->name, str, len)) {
6314 ssh->kex = k->list[j];
6323 bombout(("Couldn't agree a key exchange algorithm"
6324 " (available: %.*s)", len, str));
6328 * Note that the server's guess is considered wrong if it doesn't match
6329 * the first algorithm in our list, even if it's still the algorithm
6332 s->guessok = first_in_commasep_string(preferred, str, len);
6333 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
6335 bombout(("KEXINIT packet was incomplete"));
6338 for (i = 0; i < lenof(hostkey_algs); i++) {
6339 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
6340 ssh->hostkey = hostkey_algs[i];
6344 if (!ssh->hostkey) {
6345 bombout(("Couldn't agree a host key algorithm"
6346 " (available: %.*s)", len, str));
6350 s->guessok = s->guessok &&
6351 first_in_commasep_string(hostkey_algs[0]->name, str, len);
6352 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
6354 bombout(("KEXINIT packet was incomplete"));
6357 for (i = 0; i < s->n_preferred_ciphers; i++) {
6358 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6360 s->warn_cscipher = TRUE;
6362 for (j = 0; j < c->nciphers; j++) {
6363 if (in_commasep_string(c->list[j]->name, str, len)) {
6364 s->cscipher_tobe = c->list[j];
6369 if (s->cscipher_tobe)
6372 if (!s->cscipher_tobe) {
6373 bombout(("Couldn't agree a client-to-server cipher"
6374 " (available: %.*s)", len, str));
6378 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
6380 bombout(("KEXINIT packet was incomplete"));
6383 for (i = 0; i < s->n_preferred_ciphers; i++) {
6384 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6386 s->warn_sccipher = TRUE;
6388 for (j = 0; j < c->nciphers; j++) {
6389 if (in_commasep_string(c->list[j]->name, str, len)) {
6390 s->sccipher_tobe = c->list[j];
6395 if (s->sccipher_tobe)
6398 if (!s->sccipher_tobe) {
6399 bombout(("Couldn't agree a server-to-client cipher"
6400 " (available: %.*s)", len, str));
6404 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
6406 bombout(("KEXINIT packet was incomplete"));
6409 for (i = 0; i < s->nmacs; i++) {
6410 if (in_commasep_string(s->maclist[i]->name, str, len)) {
6411 s->csmac_tobe = s->maclist[i];
6415 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
6417 bombout(("KEXINIT packet was incomplete"));
6420 for (i = 0; i < s->nmacs; i++) {
6421 if (in_commasep_string(s->maclist[i]->name, str, len)) {
6422 s->scmac_tobe = s->maclist[i];
6426 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
6428 bombout(("KEXINIT packet was incomplete"));
6431 for (i = 0; i < lenof(compressions) + 1; i++) {
6432 const struct ssh_compress *c =
6433 i == 0 ? s->preferred_comp : compressions[i - 1];
6434 if (in_commasep_string(c->name, str, len)) {
6437 } else if (in_commasep_string(c->delayed_name, str, len)) {
6438 if (s->userauth_succeeded) {
6442 s->pending_compression = TRUE; /* try this later */
6446 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
6448 bombout(("KEXINIT packet was incomplete"));
6451 for (i = 0; i < lenof(compressions) + 1; i++) {
6452 const struct ssh_compress *c =
6453 i == 0 ? s->preferred_comp : compressions[i - 1];
6454 if (in_commasep_string(c->name, str, len)) {
6457 } else if (in_commasep_string(c->delayed_name, str, len)) {
6458 if (s->userauth_succeeded) {
6462 s->pending_compression = TRUE; /* try this later */
6466 if (s->pending_compression) {
6467 logevent("Server supports delayed compression; "
6468 "will try this later");
6470 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
6471 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
6472 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
6474 ssh->exhash = ssh->kex->hash->init();
6475 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
6476 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
6477 hash_string(ssh->kex->hash, ssh->exhash,
6478 s->our_kexinit, s->our_kexinitlen);
6479 sfree(s->our_kexinit);
6480 /* Include the type byte in the hash of server's KEXINIT */
6481 hash_string(ssh->kex->hash, ssh->exhash,
6482 pktin->body - 1, pktin->length + 1);
6485 ssh_set_frozen(ssh, 1);
6486 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
6488 ssh_dialog_callback, ssh);
6489 if (s->dlgret < 0) {
6493 bombout(("Unexpected data from server while"
6494 " waiting for user response"));
6497 } while (pktin || inlen > 0);
6498 s->dlgret = ssh->user_response;
6500 ssh_set_frozen(ssh, 0);
6501 if (s->dlgret == 0) {
6502 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
6508 if (s->warn_cscipher) {
6509 ssh_set_frozen(ssh, 1);
6510 s->dlgret = askalg(ssh->frontend,
6511 "client-to-server cipher",
6512 s->cscipher_tobe->name,
6513 ssh_dialog_callback, ssh);
6514 if (s->dlgret < 0) {
6518 bombout(("Unexpected data from server while"
6519 " waiting for user response"));
6522 } while (pktin || inlen > 0);
6523 s->dlgret = ssh->user_response;
6525 ssh_set_frozen(ssh, 0);
6526 if (s->dlgret == 0) {
6527 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6533 if (s->warn_sccipher) {
6534 ssh_set_frozen(ssh, 1);
6535 s->dlgret = askalg(ssh->frontend,
6536 "server-to-client cipher",
6537 s->sccipher_tobe->name,
6538 ssh_dialog_callback, ssh);
6539 if (s->dlgret < 0) {
6543 bombout(("Unexpected data from server while"
6544 " waiting for user response"));
6547 } while (pktin || inlen > 0);
6548 s->dlgret = ssh->user_response;
6550 ssh_set_frozen(ssh, 0);
6551 if (s->dlgret == 0) {
6552 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6558 if (s->ignorepkt) /* first_kex_packet_follows */
6559 crWaitUntilV(pktin); /* Ignore packet */
6562 if (ssh->kex->main_type == KEXTYPE_DH) {
6564 * Work out the number of bits of key we will need from the
6565 * key exchange. We start with the maximum key length of
6571 csbits = s->cscipher_tobe->keylen;
6572 scbits = s->sccipher_tobe->keylen;
6573 s->nbits = (csbits > scbits ? csbits : scbits);
6575 /* The keys only have hlen-bit entropy, since they're based on
6576 * a hash. So cap the key size at hlen bits. */
6577 if (s->nbits > ssh->kex->hash->hlen * 8)
6578 s->nbits = ssh->kex->hash->hlen * 8;
6581 * If we're doing Diffie-Hellman group exchange, start by
6582 * requesting a group.
6584 if (!ssh->kex->pdata) {
6585 logevent("Doing Diffie-Hellman group exchange");
6586 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
6588 * Work out how big a DH group we will need to allow that
6591 s->pbits = 512 << ((s->nbits - 1) / 64);
6592 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6593 ssh2_pkt_adduint32(s->pktout, s->pbits);
6594 ssh2_pkt_send_noqueue(ssh, s->pktout);
6596 crWaitUntilV(pktin);
6597 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6598 bombout(("expected key exchange group packet from server"));
6601 s->p = ssh2_pkt_getmp(pktin);
6602 s->g = ssh2_pkt_getmp(pktin);
6603 if (!s->p || !s->g) {
6604 bombout(("unable to read mp-ints from incoming group packet"));
6607 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6608 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6609 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6611 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
6612 ssh->kex_ctx = dh_setup_group(ssh->kex);
6613 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6614 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6615 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6616 ssh->kex->groupname);
6619 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6620 ssh->kex->hash->text_name);
6622 * Now generate and send e for Diffie-Hellman.
6624 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6625 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6626 s->pktout = ssh2_pkt_init(s->kex_init_value);
6627 ssh2_pkt_addmp(s->pktout, s->e);
6628 ssh2_pkt_send_noqueue(ssh, s->pktout);
6630 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
6631 crWaitUntilV(pktin);
6632 if (pktin->type != s->kex_reply_value) {
6633 bombout(("expected key exchange reply packet from server"));
6636 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
6637 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6638 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6639 s->f = ssh2_pkt_getmp(pktin);
6641 bombout(("unable to parse key exchange reply packet"));
6644 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6646 s->K = dh_find_K(ssh->kex_ctx, s->f);
6648 /* We assume everything from now on will be quick, and it might
6649 * involve user interaction. */
6650 set_busy_status(ssh->frontend, BUSY_NOT);
6652 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6653 if (!ssh->kex->pdata) {
6654 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
6655 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
6656 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
6658 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
6659 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
6661 dh_cleanup(ssh->kex_ctx);
6663 if (!ssh->kex->pdata) {
6667 } else if (ssh->kex->main_type == KEXTYPE_ECDH) {
6669 logeventf(ssh, "Doing ECDH key exchange with hash %s",
6670 ssh->kex->hash->text_name);
6671 ssh->pkt_kctx = SSH2_PKTCTX_ECDHKEX;
6674 if (!strcmp(ssh->kex->name, "ecdh-sha2-nistp256")) {
6675 s->eckey = ssh_ecdhkex_newkey(ec_p256());
6676 } else if (!strcmp(ssh->kex->name, "ecdh-sha2-nistp384")) {
6677 s->eckey = ssh_ecdhkex_newkey(ec_p384());
6678 } else if (!strcmp(ssh->kex->name, "ecdh-sha2-nistp521")) {
6679 s->eckey = ssh_ecdhkex_newkey(ec_p521());
6682 bombout(("Unable to generate key for ECDH"));
6688 int publicPointLength;
6689 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
6691 ssh_ecdhkex_freekey(s->eckey);
6692 bombout(("Unable to encode public key for ECDH"));
6695 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_ECDH_INIT);
6696 ssh2_pkt_addstring_start(s->pktout);
6697 ssh2_pkt_addstring_data(s->pktout, publicPoint, publicPointLength);
6701 ssh2_pkt_send_noqueue(ssh, s->pktout);
6703 crWaitUntilV(pktin);
6704 if (pktin->type != SSH2_MSG_KEX_ECDH_REPLY) {
6705 ssh_ecdhkex_freekey(s->eckey);
6706 bombout(("expected ECDH reply packet from server"));
6710 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6711 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6712 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6716 int publicPointLength;
6717 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
6719 ssh_ecdhkex_freekey(s->eckey);
6720 bombout(("Unable to encode public key for ECDH hash"));
6723 hash_string(ssh->kex->hash, ssh->exhash,
6724 publicPoint, publicPointLength);
6731 ssh_pkt_getstring(pktin, &keydata, &keylen);
6732 hash_string(ssh->kex->hash, ssh->exhash, keydata, keylen);
6733 s->K = ssh_ecdhkex_getkey(s->eckey, keydata, keylen);
6735 ssh_ecdhkex_freekey(s->eckey);
6736 bombout(("point received in ECDH was not valid"));
6741 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6743 ssh_ecdhkex_freekey(s->eckey);
6745 logeventf(ssh, "Doing RSA key exchange with hash %s",
6746 ssh->kex->hash->text_name);
6747 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
6749 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6752 crWaitUntilV(pktin);
6753 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
6754 bombout(("expected RSA public key packet from server"));
6758 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6759 hash_string(ssh->kex->hash, ssh->exhash,
6760 s->hostkeydata, s->hostkeylen);
6761 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6765 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
6766 s->rsakeydata = snewn(s->rsakeylen, char);
6767 memcpy(s->rsakeydata, keydata, s->rsakeylen);
6770 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
6772 sfree(s->rsakeydata);
6773 bombout(("unable to parse RSA public key from server"));
6777 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
6780 * Next, set up a shared secret K, of precisely KLEN -
6781 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6782 * RSA key modulus and HLEN is the bit length of the hash
6786 int klen = ssh_rsakex_klen(s->rsakey);
6787 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
6789 unsigned char *kstr1, *kstr2, *outstr;
6790 int kstr1len, kstr2len, outstrlen;
6792 s->K = bn_power_2(nbits - 1);
6794 for (i = 0; i < nbits; i++) {
6796 byte = random_byte();
6798 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
6802 * Encode this as an mpint.
6804 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
6805 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
6806 PUT_32BIT(kstr2, kstr1len);
6807 memcpy(kstr2 + 4, kstr1, kstr1len);
6810 * Encrypt it with the given RSA key.
6812 outstrlen = (klen + 7) / 8;
6813 outstr = snewn(outstrlen, unsigned char);
6814 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
6815 outstr, outstrlen, s->rsakey);
6818 * And send it off in a return packet.
6820 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
6821 ssh2_pkt_addstring_start(s->pktout);
6822 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
6823 ssh2_pkt_send_noqueue(ssh, s->pktout);
6825 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
6832 ssh_rsakex_freekey(s->rsakey);
6834 crWaitUntilV(pktin);
6835 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
6836 sfree(s->rsakeydata);
6837 bombout(("expected signature packet from server"));
6841 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6843 sfree(s->rsakeydata);
6846 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
6847 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
6848 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
6850 ssh->kex_ctx = NULL;
6853 debug(("Exchange hash is:\n"));
6854 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
6858 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
6859 (char *)s->exchange_hash,
6860 ssh->kex->hash->hlen)) {
6861 bombout(("Server's host key did not match the signature supplied"));
6865 s->keystr = ssh->hostkey->fmtkey(s->hkey);
6866 if (!s->got_session_id) {
6868 * Authenticate remote host: verify host key. (We've already
6869 * checked the signature of the exchange hash.)
6871 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
6872 logevent("Host key fingerprint is:");
6873 logevent(s->fingerprint);
6874 /* First check against manually configured host keys. */
6875 s->dlgret = verify_ssh_manual_host_key(ssh, s->fingerprint,
6876 ssh->hostkey, s->hkey);
6877 if (s->dlgret == 0) { /* did not match */
6878 bombout(("Host key did not appear in manually configured list"));
6880 } else if (s->dlgret < 0) { /* none configured; use standard handling */
6881 ssh_set_frozen(ssh, 1);
6882 s->dlgret = verify_ssh_host_key(ssh->frontend,
6883 ssh->savedhost, ssh->savedport,
6884 ssh->hostkey->keytype, s->keystr,
6886 ssh_dialog_callback, ssh);
6887 if (s->dlgret < 0) {
6891 bombout(("Unexpected data from server while waiting"
6892 " for user host key response"));
6895 } while (pktin || inlen > 0);
6896 s->dlgret = ssh->user_response;
6898 ssh_set_frozen(ssh, 0);
6899 if (s->dlgret == 0) {
6900 ssh_disconnect(ssh, "Aborted at host key verification", NULL,
6905 sfree(s->fingerprint);
6907 * Save this host key, to check against the one presented in
6908 * subsequent rekeys.
6910 ssh->hostkey_str = s->keystr;
6913 * In a rekey, we never present an interactive host key
6914 * verification request to the user. Instead, we simply
6915 * enforce that the key we're seeing this time is identical to
6916 * the one we saw before.
6918 if (strcmp(ssh->hostkey_str, s->keystr)) {
6919 bombout(("Host key was different in repeat key exchange"));
6924 ssh->hostkey->freekey(s->hkey);
6927 * The exchange hash from the very first key exchange is also
6928 * the session id, used in session key construction and
6931 if (!s->got_session_id) {
6932 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
6933 memcpy(ssh->v2_session_id, s->exchange_hash,
6934 sizeof(s->exchange_hash));
6935 ssh->v2_session_id_len = ssh->kex->hash->hlen;
6936 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
6937 s->got_session_id = TRUE;
6941 * Send SSH2_MSG_NEWKEYS.
6943 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
6944 ssh2_pkt_send_noqueue(ssh, s->pktout);
6945 ssh->outgoing_data_size = 0; /* start counting from here */
6948 * We've sent client NEWKEYS, so create and initialise
6949 * client-to-server session keys.
6951 if (ssh->cs_cipher_ctx)
6952 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6953 ssh->cscipher = s->cscipher_tobe;
6954 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
6956 if (ssh->cs_mac_ctx)
6957 ssh->csmac->free_context(ssh->cs_mac_ctx);
6958 ssh->csmac = s->csmac_tobe;
6959 ssh->cs_mac_ctx = ssh->csmac->make_context();
6961 if (ssh->cs_comp_ctx)
6962 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6963 ssh->cscomp = s->cscomp_tobe;
6964 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
6967 * Set IVs on client-to-server keys. Here we use the exchange
6968 * hash from the _first_ key exchange.
6971 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6972 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6973 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
6974 assert((ssh->cscipher->keylen+7) / 8 <=
6975 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6976 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
6977 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
6978 assert(ssh->cscipher->blksize <=
6979 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6980 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
6981 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
6982 assert(ssh->csmac->len <=
6983 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6984 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
6985 smemclr(keyspace, sizeof(keyspace));
6988 logeventf(ssh, "Initialised %.200s client->server encryption",
6989 ssh->cscipher->text_name);
6990 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
6991 ssh->csmac->text_name);
6992 if (ssh->cscomp->text_name)
6993 logeventf(ssh, "Initialised %s compression",
6994 ssh->cscomp->text_name);
6997 * Now our end of the key exchange is complete, we can send all
6998 * our queued higher-layer packets.
7000 ssh->queueing = FALSE;
7001 ssh2_pkt_queuesend(ssh);
7004 * Expect SSH2_MSG_NEWKEYS from server.
7006 crWaitUntilV(pktin);
7007 if (pktin->type != SSH2_MSG_NEWKEYS) {
7008 bombout(("expected new-keys packet from server"));
7011 ssh->incoming_data_size = 0; /* start counting from here */
7014 * We've seen server NEWKEYS, so create and initialise
7015 * server-to-client session keys.
7017 if (ssh->sc_cipher_ctx)
7018 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7019 ssh->sccipher = s->sccipher_tobe;
7020 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
7022 if (ssh->sc_mac_ctx)
7023 ssh->scmac->free_context(ssh->sc_mac_ctx);
7024 ssh->scmac = s->scmac_tobe;
7025 ssh->sc_mac_ctx = ssh->scmac->make_context();
7027 if (ssh->sc_comp_ctx)
7028 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7029 ssh->sccomp = s->sccomp_tobe;
7030 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
7033 * Set IVs on server-to-client keys. Here we use the exchange
7034 * hash from the _first_ key exchange.
7037 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
7038 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7039 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
7040 assert((ssh->sccipher->keylen+7) / 8 <=
7041 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7042 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
7043 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
7044 assert(ssh->sccipher->blksize <=
7045 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7046 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
7047 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
7048 assert(ssh->scmac->len <=
7049 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7050 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
7051 smemclr(keyspace, sizeof(keyspace));
7053 logeventf(ssh, "Initialised %.200s server->client encryption",
7054 ssh->sccipher->text_name);
7055 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
7056 ssh->scmac->text_name);
7057 if (ssh->sccomp->text_name)
7058 logeventf(ssh, "Initialised %s decompression",
7059 ssh->sccomp->text_name);
7062 * Free shared secret.
7067 * Key exchange is over. Loop straight back round if we have a
7068 * deferred rekey reason.
7070 if (ssh->deferred_rekey_reason) {
7071 logevent(ssh->deferred_rekey_reason);
7073 ssh->deferred_rekey_reason = NULL;
7074 goto begin_key_exchange;
7078 * Otherwise, schedule a timer for our next rekey.
7080 ssh->kex_in_progress = FALSE;
7081 ssh->last_rekey = GETTICKCOUNT();
7082 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
7083 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7087 * Now we're encrypting. Begin returning 1 to the protocol main
7088 * function so that other things can run on top of the
7089 * transport. If we ever see a KEXINIT, we must go back to the
7092 * We _also_ go back to the start if we see pktin==NULL and
7093 * inlen negative, because this is a special signal meaning
7094 * `initiate client-driven rekey', and `in' contains a message
7095 * giving the reason for the rekey.
7097 * inlen==-1 means always initiate a rekey;
7098 * inlen==-2 means that userauth has completed successfully and
7099 * we should consider rekeying (for delayed compression).
7101 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
7102 (!pktin && inlen < 0))) {
7104 if (!ssh->protocol_initial_phase_done) {
7105 ssh->protocol_initial_phase_done = TRUE;
7107 * Allow authconn to initialise itself.
7109 do_ssh2_authconn(ssh, NULL, 0, NULL);
7114 logevent("Server initiated key re-exchange");
7118 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
7119 * delayed compression, if it's available.
7121 * draft-miller-secsh-compression-delayed-00 says that you
7122 * negotiate delayed compression in the first key exchange, and
7123 * both sides start compressing when the server has sent
7124 * USERAUTH_SUCCESS. This has a race condition -- the server
7125 * can't know when the client has seen it, and thus which incoming
7126 * packets it should treat as compressed.
7128 * Instead, we do the initial key exchange without offering the
7129 * delayed methods, but note if the server offers them; when we
7130 * get here, if a delayed method was available that was higher
7131 * on our list than what we got, we initiate a rekey in which we
7132 * _do_ list the delayed methods (and hopefully get it as a
7133 * result). Subsequent rekeys will do the same.
7135 assert(!s->userauth_succeeded); /* should only happen once */
7136 s->userauth_succeeded = TRUE;
7137 if (!s->pending_compression)
7138 /* Can't see any point rekeying. */
7139 goto wait_for_rekey; /* this is utterly horrid */
7140 /* else fall through to rekey... */
7141 s->pending_compression = FALSE;
7144 * Now we've decided to rekey.
7146 * Special case: if the server bug is set that doesn't
7147 * allow rekeying, we give a different log message and
7148 * continue waiting. (If such a server _initiates_ a rekey,
7149 * we process it anyway!)
7151 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
7152 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
7154 /* Reset the counters, so that at least this message doesn't
7155 * hit the event log _too_ often. */
7156 ssh->outgoing_data_size = 0;
7157 ssh->incoming_data_size = 0;
7158 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
7160 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7163 goto wait_for_rekey; /* this is still utterly horrid */
7165 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
7168 goto begin_key_exchange;
7174 * Add data to an SSH-2 channel output buffer.
7176 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
7179 bufchain_add(&c->v.v2.outbuffer, buf, len);
7183 * Attempt to send data on an SSH-2 channel.
7185 static int ssh2_try_send(struct ssh_channel *c)
7188 struct Packet *pktout;
7191 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
7194 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
7195 if ((unsigned)len > c->v.v2.remwindow)
7196 len = c->v.v2.remwindow;
7197 if ((unsigned)len > c->v.v2.remmaxpkt)
7198 len = c->v.v2.remmaxpkt;
7199 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
7200 ssh2_pkt_adduint32(pktout, c->remoteid);
7201 ssh2_pkt_addstring_start(pktout);
7202 ssh2_pkt_addstring_data(pktout, data, len);
7203 ssh2_pkt_send(ssh, pktout);
7204 bufchain_consume(&c->v.v2.outbuffer, len);
7205 c->v.v2.remwindow -= len;
7209 * After having sent as much data as we can, return the amount
7212 ret = bufchain_size(&c->v.v2.outbuffer);
7215 * And if there's no data pending but we need to send an EOF, send
7218 if (!ret && c->pending_eof)
7219 ssh_channel_try_eof(c);
7224 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
7227 if (c->closes & CLOSES_SENT_EOF)
7228 return; /* don't send on channels we've EOFed */
7229 bufsize = ssh2_try_send(c);
7232 case CHAN_MAINSESSION:
7233 /* stdin need not receive an unthrottle
7234 * notification since it will be polled */
7237 x11_unthrottle(c->u.x11.xconn);
7240 /* agent sockets are request/response and need no
7241 * buffer management */
7244 pfd_unthrottle(c->u.pfd.pf);
7250 static int ssh_is_simple(Ssh ssh)
7253 * We use the 'simple' variant of the SSH protocol if we're asked
7254 * to, except not if we're also doing connection-sharing (either
7255 * tunnelling our packets over an upstream or expecting to be
7256 * tunnelled over ourselves), since then the assumption that we
7257 * have only one channel to worry about is not true after all.
7259 return (conf_get_int(ssh->conf, CONF_ssh_simple) &&
7260 !ssh->bare_connection && !ssh->connshare);
7264 * Set up most of a new ssh_channel for SSH-2.
7266 static void ssh2_channel_init(struct ssh_channel *c)
7269 c->localid = alloc_channel_id(ssh);
7271 c->pending_eof = FALSE;
7272 c->throttling_conn = FALSE;
7273 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
7274 ssh_is_simple(ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
7275 c->v.v2.chanreq_head = NULL;
7276 c->v.v2.throttle_state = UNTHROTTLED;
7277 bufchain_init(&c->v.v2.outbuffer);
7281 * Construct the common parts of a CHANNEL_OPEN.
7283 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c, char *type)
7285 struct Packet *pktout;
7287 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7288 ssh2_pkt_addstring(pktout, type);
7289 ssh2_pkt_adduint32(pktout, c->localid);
7290 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7291 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7296 * CHANNEL_FAILURE doesn't come with any indication of what message
7297 * caused it, so we have to keep track of the outstanding
7298 * CHANNEL_REQUESTs ourselves.
7300 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
7301 cchandler_fn_t handler, void *ctx)
7303 struct outstanding_channel_request *ocr =
7304 snew(struct outstanding_channel_request);
7306 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7307 ocr->handler = handler;
7310 if (!c->v.v2.chanreq_head)
7311 c->v.v2.chanreq_head = ocr;
7313 c->v.v2.chanreq_tail->next = ocr;
7314 c->v.v2.chanreq_tail = ocr;
7318 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
7319 * NULL then a reply will be requested and the handler will be called
7320 * when it arrives. The returned packet is ready to have any
7321 * request-specific data added and be sent. Note that if a handler is
7322 * provided, it's essential that the request actually be sent.
7324 * The handler will usually be passed the response packet in pktin. If
7325 * pktin is NULL, this means that no reply will ever be forthcoming
7326 * (e.g. because the entire connection is being destroyed, or because
7327 * the server initiated channel closure before we saw the response)
7328 * and the handler should free any storage it's holding.
7330 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c, char *type,
7331 cchandler_fn_t handler, void *ctx)
7333 struct Packet *pktout;
7335 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7336 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7337 ssh2_pkt_adduint32(pktout, c->remoteid);
7338 ssh2_pkt_addstring(pktout, type);
7339 ssh2_pkt_addbool(pktout, handler != NULL);
7340 if (handler != NULL)
7341 ssh2_queue_chanreq_handler(c, handler, ctx);
7346 * Potentially enlarge the window on an SSH-2 channel.
7348 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
7350 static void ssh2_set_window(struct ssh_channel *c, int newwin)
7355 * Never send WINDOW_ADJUST for a channel that the remote side has
7356 * already sent EOF on; there's no point, since it won't be
7357 * sending any more data anyway. Ditto if _we've_ already sent
7360 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
7364 * Also, never widen the window for an X11 channel when we're
7365 * still waiting to see its initial auth and may yet hand it off
7368 if (c->type == CHAN_X11 && c->u.x11.initial)
7372 * If the remote end has a habit of ignoring maxpkt, limit the
7373 * window so that it has no choice (assuming it doesn't ignore the
7376 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
7377 newwin = OUR_V2_MAXPKT;
7380 * Only send a WINDOW_ADJUST if there's significantly more window
7381 * available than the other end thinks there is. This saves us
7382 * sending a WINDOW_ADJUST for every character in a shell session.
7384 * "Significant" is arbitrarily defined as half the window size.
7386 if (newwin / 2 >= c->v.v2.locwindow) {
7387 struct Packet *pktout;
7391 * In order to keep track of how much window the client
7392 * actually has available, we'd like it to acknowledge each
7393 * WINDOW_ADJUST. We can't do that directly, so we accompany
7394 * it with a CHANNEL_REQUEST that has to be acknowledged.
7396 * This is only necessary if we're opening the window wide.
7397 * If we're not, then throughput is being constrained by
7398 * something other than the maximum window size anyway.
7400 if (newwin == c->v.v2.locmaxwin &&
7401 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
7402 up = snew(unsigned);
7403 *up = newwin - c->v.v2.locwindow;
7404 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
7405 ssh2_handle_winadj_response, up);
7406 ssh2_pkt_send(ssh, pktout);
7408 if (c->v.v2.throttle_state != UNTHROTTLED)
7409 c->v.v2.throttle_state = UNTHROTTLING;
7411 /* Pretend the WINDOW_ADJUST was acked immediately. */
7412 c->v.v2.remlocwin = newwin;
7413 c->v.v2.throttle_state = THROTTLED;
7415 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7416 ssh2_pkt_adduint32(pktout, c->remoteid);
7417 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
7418 ssh2_pkt_send(ssh, pktout);
7419 c->v.v2.locwindow = newwin;
7424 * Find the channel associated with a message. If there's no channel,
7425 * or it's not properly open, make a noise about it and return NULL.
7427 static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
7429 unsigned localid = ssh_pkt_getuint32(pktin);
7430 struct ssh_channel *c;
7432 c = find234(ssh->channels, &localid, ssh_channelfind);
7434 (c->type != CHAN_SHARING && c->halfopen &&
7435 pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
7436 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
7437 char *buf = dupprintf("Received %s for %s channel %u",
7438 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
7440 c ? "half-open" : "nonexistent", localid);
7441 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
7448 static void ssh2_handle_winadj_response(struct ssh_channel *c,
7449 struct Packet *pktin, void *ctx)
7451 unsigned *sizep = ctx;
7454 * Winadj responses should always be failures. However, at least
7455 * one server ("boks_sshd") is known to return SUCCESS for channel
7456 * requests it's never heard of, such as "winadj@putty". Raised
7457 * with foxt.com as bug 090916-090424, but for the sake of a quiet
7458 * life, we don't worry about what kind of response we got.
7461 c->v.v2.remlocwin += *sizep;
7464 * winadj messages are only sent when the window is fully open, so
7465 * if we get an ack of one, we know any pending unthrottle is
7468 if (c->v.v2.throttle_state == UNTHROTTLING)
7469 c->v.v2.throttle_state = UNTHROTTLED;
7472 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
7474 struct ssh_channel *c = ssh2_channel_msg(ssh, pktin);
7475 struct outstanding_channel_request *ocr;
7478 if (c->type == CHAN_SHARING) {
7479 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7480 pktin->body, pktin->length);
7483 ocr = c->v.v2.chanreq_head;
7485 ssh2_msg_unexpected(ssh, pktin);
7488 ocr->handler(c, pktin, ocr->ctx);
7489 c->v.v2.chanreq_head = ocr->next;
7492 * We may now initiate channel-closing procedures, if that
7493 * CHANNEL_REQUEST was the last thing outstanding before we send
7496 ssh2_channel_check_close(c);
7499 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
7501 struct ssh_channel *c;
7502 c = ssh2_channel_msg(ssh, pktin);
7505 if (c->type == CHAN_SHARING) {
7506 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7507 pktin->body, pktin->length);
7510 if (!(c->closes & CLOSES_SENT_EOF)) {
7511 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
7512 ssh2_try_send_and_unthrottle(ssh, c);
7516 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
7520 struct ssh_channel *c;
7521 c = ssh2_channel_msg(ssh, pktin);
7524 if (c->type == CHAN_SHARING) {
7525 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7526 pktin->body, pktin->length);
7529 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
7530 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
7531 return; /* extended but not stderr */
7532 ssh_pkt_getstring(pktin, &data, &length);
7535 c->v.v2.locwindow -= length;
7536 c->v.v2.remlocwin -= length;
7538 case CHAN_MAINSESSION:
7540 from_backend(ssh->frontend, pktin->type ==
7541 SSH2_MSG_CHANNEL_EXTENDED_DATA,
7545 bufsize = x11_send(c->u.x11.xconn, data, length);
7548 bufsize = pfd_send(c->u.pfd.pf, data, length);
7551 while (length > 0) {
7552 if (c->u.a.lensofar < 4) {
7553 unsigned int l = min(4 - c->u.a.lensofar,
7555 memcpy(c->u.a.msglen + c->u.a.lensofar,
7559 c->u.a.lensofar += l;
7561 if (c->u.a.lensofar == 4) {
7563 4 + GET_32BIT(c->u.a.msglen);
7564 c->u.a.message = snewn(c->u.a.totallen,
7566 memcpy(c->u.a.message, c->u.a.msglen, 4);
7568 if (c->u.a.lensofar >= 4 && length > 0) {
7570 min(c->u.a.totallen - c->u.a.lensofar,
7572 memcpy(c->u.a.message + c->u.a.lensofar,
7576 c->u.a.lensofar += l;
7578 if (c->u.a.lensofar == c->u.a.totallen) {
7581 c->u.a.outstanding_requests++;
7582 if (agent_query(c->u.a.message,
7585 ssh_agentf_callback, c))
7586 ssh_agentf_callback(c, reply, replylen);
7587 sfree(c->u.a.message);
7588 c->u.a.message = NULL;
7589 c->u.a.lensofar = 0;
7596 * If it looks like the remote end hit the end of its window,
7597 * and we didn't want it to do that, think about using a
7600 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
7601 c->v.v2.locmaxwin < 0x40000000)
7602 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
7604 * If we are not buffering too much data,
7605 * enlarge the window again at the remote side.
7606 * If we are buffering too much, we may still
7607 * need to adjust the window if the server's
7610 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
7611 c->v.v2.locmaxwin - bufsize : 0);
7613 * If we're either buffering way too much data, or if we're
7614 * buffering anything at all and we're in "simple" mode,
7615 * throttle the whole channel.
7617 if ((bufsize > c->v.v2.locmaxwin || (ssh_is_simple(ssh) && bufsize>0))
7618 && !c->throttling_conn) {
7619 c->throttling_conn = 1;
7620 ssh_throttle_conn(ssh, +1);
7625 static void ssh_check_termination(Ssh ssh)
7627 if (ssh->version == 2 &&
7628 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
7629 count234(ssh->channels) == 0 &&
7630 !(ssh->connshare && share_ndownstreams(ssh->connshare) > 0)) {
7632 * We used to send SSH_MSG_DISCONNECT here, because I'd
7633 * believed that _every_ conforming SSH-2 connection had to
7634 * end with a disconnect being sent by at least one side;
7635 * apparently I was wrong and it's perfectly OK to
7636 * unceremoniously slam the connection shut when you're done,
7637 * and indeed OpenSSH feels this is more polite than sending a
7638 * DISCONNECT. So now we don't.
7640 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
7644 void ssh_sharing_downstream_connected(Ssh ssh, unsigned id)
7646 logeventf(ssh, "Connection sharing downstream #%u connected", id);
7649 void ssh_sharing_downstream_disconnected(Ssh ssh, unsigned id)
7651 logeventf(ssh, "Connection sharing downstream #%u disconnected", id);
7652 ssh_check_termination(ssh);
7655 void ssh_sharing_logf(Ssh ssh, unsigned id, const char *logfmt, ...)
7660 va_start(ap, logfmt);
7661 buf = dupvprintf(logfmt, ap);
7664 logeventf(ssh, "Connection sharing downstream #%u: %s", id, buf);
7666 logeventf(ssh, "Connection sharing: %s", buf);
7670 static void ssh_channel_destroy(struct ssh_channel *c)
7675 case CHAN_MAINSESSION:
7676 ssh->mainchan = NULL;
7677 update_specials_menu(ssh->frontend);
7680 if (c->u.x11.xconn != NULL)
7681 x11_close(c->u.x11.xconn);
7682 logevent("Forwarded X11 connection terminated");
7685 sfree(c->u.a.message);
7688 if (c->u.pfd.pf != NULL)
7689 pfd_close(c->u.pfd.pf);
7690 logevent("Forwarded port closed");
7694 del234(ssh->channels, c);
7695 if (ssh->version == 2) {
7696 bufchain_clear(&c->v.v2.outbuffer);
7697 assert(c->v.v2.chanreq_head == NULL);
7702 * If that was the last channel left open, we might need to
7705 ssh_check_termination(ssh);
7708 static void ssh2_channel_check_close(struct ssh_channel *c)
7711 struct Packet *pktout;
7715 * If we've sent out our own CHANNEL_OPEN but not yet seen
7716 * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
7717 * it's too early to be sending close messages of any kind.
7722 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
7723 c->type == CHAN_ZOMBIE) &&
7724 !c->v.v2.chanreq_head &&
7725 !(c->closes & CLOSES_SENT_CLOSE)) {
7727 * We have both sent and received EOF (or the channel is a
7728 * zombie), and we have no outstanding channel requests, which
7729 * means the channel is in final wind-up. But we haven't sent
7730 * CLOSE, so let's do so now.
7732 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
7733 ssh2_pkt_adduint32(pktout, c->remoteid);
7734 ssh2_pkt_send(ssh, pktout);
7735 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
7738 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
7739 assert(c->v.v2.chanreq_head == NULL);
7741 * We have both sent and received CLOSE, which means we're
7742 * completely done with the channel.
7744 ssh_channel_destroy(c);
7748 static void ssh2_channel_got_eof(struct ssh_channel *c)
7750 if (c->closes & CLOSES_RCVD_EOF)
7751 return; /* already seen EOF */
7752 c->closes |= CLOSES_RCVD_EOF;
7754 if (c->type == CHAN_X11) {
7755 x11_send_eof(c->u.x11.xconn);
7756 } else if (c->type == CHAN_AGENT) {
7757 if (c->u.a.outstanding_requests == 0) {
7758 /* Manufacture an outgoing EOF in response to the incoming one. */
7759 sshfwd_write_eof(c);
7761 } else if (c->type == CHAN_SOCKDATA) {
7762 pfd_send_eof(c->u.pfd.pf);
7763 } else if (c->type == CHAN_MAINSESSION) {
7766 if (!ssh->sent_console_eof &&
7767 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
7769 * Either from_backend_eof told us that the front end
7770 * wants us to close the outgoing side of the connection
7771 * as soon as we see EOF from the far end, or else we've
7772 * unilaterally decided to do that because we've allocated
7773 * a remote pty and hence EOF isn't a particularly
7774 * meaningful concept.
7776 sshfwd_write_eof(c);
7778 ssh->sent_console_eof = TRUE;
7781 ssh2_channel_check_close(c);
7784 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
7786 struct ssh_channel *c;
7788 c = ssh2_channel_msg(ssh, pktin);
7791 if (c->type == CHAN_SHARING) {
7792 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7793 pktin->body, pktin->length);
7796 ssh2_channel_got_eof(c);
7799 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
7801 struct ssh_channel *c;
7803 c = ssh2_channel_msg(ssh, pktin);
7806 if (c->type == CHAN_SHARING) {
7807 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7808 pktin->body, pktin->length);
7813 * When we receive CLOSE on a channel, we assume it comes with an
7814 * implied EOF if we haven't seen EOF yet.
7816 ssh2_channel_got_eof(c);
7818 if (!(ssh->remote_bugs & BUG_SENDS_LATE_REQUEST_REPLY)) {
7820 * It also means we stop expecting to see replies to any
7821 * outstanding channel requests, so clean those up too.
7822 * (ssh_chanreq_init will enforce by assertion that we don't
7823 * subsequently put anything back on this list.)
7825 while (c->v.v2.chanreq_head) {
7826 struct outstanding_channel_request *ocr = c->v.v2.chanreq_head;
7827 ocr->handler(c, NULL, ocr->ctx);
7828 c->v.v2.chanreq_head = ocr->next;
7834 * And we also send an outgoing EOF, if we haven't already, on the
7835 * assumption that CLOSE is a pretty forceful announcement that
7836 * the remote side is doing away with the entire channel. (If it
7837 * had wanted to send us EOF and continue receiving data from us,
7838 * it would have just sent CHANNEL_EOF.)
7840 if (!(c->closes & CLOSES_SENT_EOF)) {
7842 * Make sure we don't read any more from whatever our local
7843 * data source is for this channel.
7846 case CHAN_MAINSESSION:
7847 ssh->send_ok = 0; /* stop trying to read from stdin */
7850 x11_override_throttle(c->u.x11.xconn, 1);
7853 pfd_override_throttle(c->u.pfd.pf, 1);
7858 * Abandon any buffered data we still wanted to send to this
7859 * channel. Receiving a CHANNEL_CLOSE is an indication that
7860 * the server really wants to get on and _destroy_ this
7861 * channel, and it isn't going to send us any further
7862 * WINDOW_ADJUSTs to permit us to send pending stuff.
7864 bufchain_clear(&c->v.v2.outbuffer);
7867 * Send outgoing EOF.
7869 sshfwd_write_eof(c);
7873 * Now process the actual close.
7875 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
7876 c->closes |= CLOSES_RCVD_CLOSE;
7877 ssh2_channel_check_close(c);
7881 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
7883 struct ssh_channel *c;
7885 c = ssh2_channel_msg(ssh, pktin);
7888 if (c->type == CHAN_SHARING) {
7889 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7890 pktin->body, pktin->length);
7893 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7894 c->remoteid = ssh_pkt_getuint32(pktin);
7895 c->halfopen = FALSE;
7896 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7897 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7899 if (c->type == CHAN_SOCKDATA_DORMANT) {
7900 c->type = CHAN_SOCKDATA;
7902 pfd_confirm(c->u.pfd.pf);
7903 } else if (c->type == CHAN_ZOMBIE) {
7905 * This case can occur if a local socket error occurred
7906 * between us sending out CHANNEL_OPEN and receiving
7907 * OPEN_CONFIRMATION. In this case, all we can do is
7908 * immediately initiate close proceedings now that we know the
7909 * server's id to put in the close message.
7911 ssh2_channel_check_close(c);
7914 * We never expect to receive OPEN_CONFIRMATION for any
7915 * *other* channel type (since only local-to-remote port
7916 * forwardings cause us to send CHANNEL_OPEN after the main
7917 * channel is live - all other auxiliary channel types are
7918 * initiated from the server end). It's safe to enforce this
7919 * by assertion rather than by ssh_disconnect, because the
7920 * real point is that we never constructed a half-open channel
7921 * structure in the first place with any type other than the
7924 assert(!"Funny channel type in ssh2_msg_channel_open_confirmation");
7928 ssh_channel_try_eof(c); /* in case we had a pending EOF */
7931 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
7933 static const char *const reasons[] = {
7934 "<unknown reason code>",
7935 "Administratively prohibited",
7937 "Unknown channel type",
7938 "Resource shortage",
7940 unsigned reason_code;
7941 char *reason_string;
7943 struct ssh_channel *c;
7945 c = ssh2_channel_msg(ssh, pktin);
7948 if (c->type == CHAN_SHARING) {
7949 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7950 pktin->body, pktin->length);
7953 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7955 if (c->type == CHAN_SOCKDATA_DORMANT) {
7956 reason_code = ssh_pkt_getuint32(pktin);
7957 if (reason_code >= lenof(reasons))
7958 reason_code = 0; /* ensure reasons[reason_code] in range */
7959 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
7960 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
7961 reasons[reason_code], reason_length, reason_string);
7963 pfd_close(c->u.pfd.pf);
7964 } else if (c->type == CHAN_ZOMBIE) {
7966 * This case can occur if a local socket error occurred
7967 * between us sending out CHANNEL_OPEN and receiving
7968 * OPEN_FAILURE. In this case, we need do nothing except allow
7969 * the code below to throw the half-open channel away.
7973 * We never expect to receive OPEN_FAILURE for any *other*
7974 * channel type (since only local-to-remote port forwardings
7975 * cause us to send CHANNEL_OPEN after the main channel is
7976 * live - all other auxiliary channel types are initiated from
7977 * the server end). It's safe to enforce this by assertion
7978 * rather than by ssh_disconnect, because the real point is
7979 * that we never constructed a half-open channel structure in
7980 * the first place with any type other than the above.
7982 assert(!"Funny channel type in ssh2_msg_channel_open_failure");
7985 del234(ssh->channels, c);
7989 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
7992 int typelen, want_reply;
7993 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
7994 struct ssh_channel *c;
7995 struct Packet *pktout;
7997 c = ssh2_channel_msg(ssh, pktin);
8000 if (c->type == CHAN_SHARING) {
8001 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8002 pktin->body, pktin->length);
8005 ssh_pkt_getstring(pktin, &type, &typelen);
8006 want_reply = ssh2_pkt_getbool(pktin);
8008 if (c->closes & CLOSES_SENT_CLOSE) {
8010 * We don't reply to channel requests after we've sent
8011 * CHANNEL_CLOSE for the channel, because our reply might
8012 * cross in the network with the other side's CHANNEL_CLOSE
8013 * and arrive after they have wound the channel up completely.
8019 * Having got the channel number, we now look at
8020 * the request type string to see if it's something
8023 if (c == ssh->mainchan) {
8025 * We recognise "exit-status" and "exit-signal" on
8026 * the primary channel.
8028 if (typelen == 11 &&
8029 !memcmp(type, "exit-status", 11)) {
8031 ssh->exitcode = ssh_pkt_getuint32(pktin);
8032 logeventf(ssh, "Server sent command exit status %d",
8034 reply = SSH2_MSG_CHANNEL_SUCCESS;
8036 } else if (typelen == 11 &&
8037 !memcmp(type, "exit-signal", 11)) {
8039 int is_plausible = TRUE, is_int = FALSE;
8040 char *fmt_sig = "", *fmt_msg = "";
8042 int msglen = 0, core = FALSE;
8043 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
8044 * provide an `int' for the signal, despite its
8045 * having been a `string' in the drafts of RFC 4254 since at
8046 * least 2001. (Fixed in session.c 1.147.) Try to
8047 * infer which we can safely parse it as. */
8049 unsigned char *p = pktin->body +
8051 long len = pktin->length - pktin->savedpos;
8052 unsigned long num = GET_32BIT(p); /* what is it? */
8053 /* If it's 0, it hardly matters; assume string */
8057 int maybe_int = FALSE, maybe_str = FALSE;
8058 #define CHECK_HYPOTHESIS(offset, result) \
8061 int q = toint(offset); \
8062 if (q >= 0 && q+4 <= len) { \
8063 q = toint(q + 4 + GET_32BIT(p+q)); \
8064 if (q >= 0 && q+4 <= len && \
8065 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
8070 CHECK_HYPOTHESIS(4+1, maybe_int);
8071 CHECK_HYPOTHESIS(4+num+1, maybe_str);
8072 #undef CHECK_HYPOTHESIS
8073 if (maybe_int && !maybe_str)
8075 else if (!maybe_int && maybe_str)
8078 /* Crikey. Either or neither. Panic. */
8079 is_plausible = FALSE;
8082 ssh->exitcode = 128; /* means `unknown signal' */
8085 /* Old non-standard OpenSSH. */
8086 int signum = ssh_pkt_getuint32(pktin);
8087 fmt_sig = dupprintf(" %d", signum);
8088 ssh->exitcode = 128 + signum;
8090 /* As per RFC 4254. */
8093 ssh_pkt_getstring(pktin, &sig, &siglen);
8094 /* Signal name isn't supposed to be blank, but
8095 * let's cope gracefully if it is. */
8097 fmt_sig = dupprintf(" \"%.*s\"",
8102 * Really hideous method of translating the
8103 * signal description back into a locally
8104 * meaningful number.
8109 #define TRANSLATE_SIGNAL(s) \
8110 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
8111 ssh->exitcode = 128 + SIG ## s
8113 TRANSLATE_SIGNAL(ABRT);
8116 TRANSLATE_SIGNAL(ALRM);
8119 TRANSLATE_SIGNAL(FPE);
8122 TRANSLATE_SIGNAL(HUP);
8125 TRANSLATE_SIGNAL(ILL);
8128 TRANSLATE_SIGNAL(INT);
8131 TRANSLATE_SIGNAL(KILL);
8134 TRANSLATE_SIGNAL(PIPE);
8137 TRANSLATE_SIGNAL(QUIT);
8140 TRANSLATE_SIGNAL(SEGV);
8143 TRANSLATE_SIGNAL(TERM);
8146 TRANSLATE_SIGNAL(USR1);
8149 TRANSLATE_SIGNAL(USR2);
8151 #undef TRANSLATE_SIGNAL
8153 ssh->exitcode = 128;
8155 core = ssh2_pkt_getbool(pktin);
8156 ssh_pkt_getstring(pktin, &msg, &msglen);
8158 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
8160 /* ignore lang tag */
8161 } /* else don't attempt to parse */
8162 logeventf(ssh, "Server exited on signal%s%s%s",
8163 fmt_sig, core ? " (core dumped)" : "",
8165 if (*fmt_sig) sfree(fmt_sig);
8166 if (*fmt_msg) sfree(fmt_msg);
8167 reply = SSH2_MSG_CHANNEL_SUCCESS;
8172 * This is a channel request we don't know
8173 * about, so we now either ignore the request
8174 * or respond with CHANNEL_FAILURE, depending
8177 reply = SSH2_MSG_CHANNEL_FAILURE;
8180 pktout = ssh2_pkt_init(reply);
8181 ssh2_pkt_adduint32(pktout, c->remoteid);
8182 ssh2_pkt_send(ssh, pktout);
8186 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
8189 int typelen, want_reply;
8190 struct Packet *pktout;
8192 ssh_pkt_getstring(pktin, &type, &typelen);
8193 want_reply = ssh2_pkt_getbool(pktin);
8196 * We currently don't support any global requests
8197 * at all, so we either ignore the request or
8198 * respond with REQUEST_FAILURE, depending on
8202 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
8203 ssh2_pkt_send(ssh, pktout);
8207 struct X11FakeAuth *ssh_sharing_add_x11_display(Ssh ssh, int authtype,
8211 struct X11FakeAuth *auth;
8214 * Make up a new set of fake X11 auth data, and add it to the tree
8215 * of currently valid ones with an indication of the sharing
8216 * context that it's relevant to.
8218 auth = x11_invent_fake_auth(ssh->x11authtree, authtype);
8219 auth->share_cs = share_cs;
8220 auth->share_chan = share_chan;
8225 void ssh_sharing_remove_x11_display(Ssh ssh, struct X11FakeAuth *auth)
8227 del234(ssh->x11authtree, auth);
8228 x11_free_fake_auth(auth);
8231 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
8239 struct ssh_channel *c;
8240 unsigned remid, winsize, pktsize;
8241 unsigned our_winsize_override = 0;
8242 struct Packet *pktout;
8244 ssh_pkt_getstring(pktin, &type, &typelen);
8245 c = snew(struct ssh_channel);
8248 remid = ssh_pkt_getuint32(pktin);
8249 winsize = ssh_pkt_getuint32(pktin);
8250 pktsize = ssh_pkt_getuint32(pktin);
8252 if (typelen == 3 && !memcmp(type, "x11", 3)) {
8255 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8256 addrstr = snewn(peeraddrlen+1, char);
8257 memcpy(addrstr, peeraddr, peeraddrlen);
8258 addrstr[peeraddrlen] = '\0';
8259 peerport = ssh_pkt_getuint32(pktin);
8261 logeventf(ssh, "Received X11 connect request from %s:%d",
8264 if (!ssh->X11_fwd_enabled && !ssh->connshare)
8265 error = "X11 forwarding is not enabled";
8267 c->u.x11.xconn = x11_init(ssh->x11authtree, c,
8270 c->u.x11.initial = TRUE;
8273 * If we are a connection-sharing upstream, then we should
8274 * initially present a very small window, adequate to take
8275 * the X11 initial authorisation packet but not much more.
8276 * Downstream will then present us a larger window (by
8277 * fiat of the connection-sharing protocol) and we can
8278 * guarantee to send a positive-valued WINDOW_ADJUST.
8281 our_winsize_override = 128;
8283 logevent("Opened X11 forward channel");
8287 } else if (typelen == 15 &&
8288 !memcmp(type, "forwarded-tcpip", 15)) {
8289 struct ssh_rportfwd pf, *realpf;
8292 ssh_pkt_getstring(pktin, &shost, &shostlen);/* skip address */
8293 pf.shost = dupprintf("%.*s", shostlen, shost);
8294 pf.sport = ssh_pkt_getuint32(pktin);
8295 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8296 peerport = ssh_pkt_getuint32(pktin);
8297 realpf = find234(ssh->rportfwds, &pf, NULL);
8298 logeventf(ssh, "Received remote port %s:%d open request "
8299 "from %s:%d", pf.shost, pf.sport, peeraddr, peerport);
8302 if (realpf == NULL) {
8303 error = "Remote port is not recognised";
8307 if (realpf->share_ctx) {
8309 * This port forwarding is on behalf of a
8310 * connection-sharing downstream, so abandon our own
8311 * channel-open procedure and just pass the message on
8314 share_got_pkt_from_server(realpf->share_ctx, pktin->type,
8315 pktin->body, pktin->length);
8320 err = pfd_connect(&c->u.pfd.pf, realpf->dhost, realpf->dport,
8321 c, ssh->conf, realpf->pfrec->addressfamily);
8322 logeventf(ssh, "Attempting to forward remote port to "
8323 "%s:%d", realpf->dhost, realpf->dport);
8325 logeventf(ssh, "Port open failed: %s", err);
8327 error = "Port open failed";
8329 logevent("Forwarded port opened successfully");
8330 c->type = CHAN_SOCKDATA;
8333 } else if (typelen == 22 &&
8334 !memcmp(type, "auth-agent@openssh.com", 22)) {
8335 if (!ssh->agentfwd_enabled)
8336 error = "Agent forwarding is not enabled";
8338 c->type = CHAN_AGENT; /* identify channel type */
8339 c->u.a.lensofar = 0;
8340 c->u.a.message = NULL;
8341 c->u.a.outstanding_requests = 0;
8344 error = "Unsupported channel type requested";
8347 c->remoteid = remid;
8348 c->halfopen = FALSE;
8350 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
8351 ssh2_pkt_adduint32(pktout, c->remoteid);
8352 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
8353 ssh2_pkt_addstring(pktout, error);
8354 ssh2_pkt_addstring(pktout, "en"); /* language tag */
8355 ssh2_pkt_send(ssh, pktout);
8356 logeventf(ssh, "Rejected channel open: %s", error);
8359 ssh2_channel_init(c);
8360 c->v.v2.remwindow = winsize;
8361 c->v.v2.remmaxpkt = pktsize;
8362 if (our_winsize_override) {
8363 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
8364 our_winsize_override;
8366 add234(ssh->channels, c);
8367 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
8368 ssh2_pkt_adduint32(pktout, c->remoteid);
8369 ssh2_pkt_adduint32(pktout, c->localid);
8370 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
8371 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8372 ssh2_pkt_send(ssh, pktout);
8376 void sshfwd_x11_sharing_handover(struct ssh_channel *c,
8377 void *share_cs, void *share_chan,
8378 const char *peer_addr, int peer_port,
8379 int endian, int protomajor, int protominor,
8380 const void *initial_data, int initial_len)
8383 * This function is called when we've just discovered that an X
8384 * forwarding channel on which we'd been handling the initial auth
8385 * ourselves turns out to be destined for a connection-sharing
8386 * downstream. So we turn the channel into a CHAN_SHARING, meaning
8387 * that we completely stop tracking windows and buffering data and
8388 * just pass more or less unmodified SSH messages back and forth.
8390 c->type = CHAN_SHARING;
8391 c->u.sharing.ctx = share_cs;
8392 share_setup_x11_channel(share_cs, share_chan,
8393 c->localid, c->remoteid, c->v.v2.remwindow,
8394 c->v.v2.remmaxpkt, c->v.v2.locwindow,
8395 peer_addr, peer_port, endian,
8396 protomajor, protominor,
8397 initial_data, initial_len);
8400 void sshfwd_x11_is_local(struct ssh_channel *c)
8403 * This function is called when we've just discovered that an X
8404 * forwarding channel is _not_ destined for a connection-sharing
8405 * downstream but we're going to handle it ourselves. We stop
8406 * presenting a cautiously small window and go into ordinary data
8409 c->u.x11.initial = FALSE;
8410 ssh2_set_window(c, ssh_is_simple(c->ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE);
8414 * Buffer banner messages for later display at some convenient point,
8415 * if we're going to display them.
8417 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
8419 /* Arbitrary limit to prevent unbounded inflation of buffer */
8420 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
8421 bufchain_size(&ssh->banner) <= 131072) {
8422 char *banner = NULL;
8424 ssh_pkt_getstring(pktin, &banner, &size);
8426 bufchain_add(&ssh->banner, banner, size);
8430 /* Helper function to deal with sending tty modes for "pty-req" */
8431 static void ssh2_send_ttymode(void *data, char *mode, char *val)
8433 struct Packet *pktout = (struct Packet *)data;
8435 unsigned int arg = 0;
8436 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
8437 if (i == lenof(ssh_ttymodes)) return;
8438 switch (ssh_ttymodes[i].type) {
8440 arg = ssh_tty_parse_specchar(val);
8443 arg = ssh_tty_parse_boolean(val);
8446 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
8447 ssh2_pkt_adduint32(pktout, arg);
8450 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
8453 struct ssh2_setup_x11_state {
8457 struct Packet *pktout;
8458 crStateP(ssh2_setup_x11_state, ctx);
8462 logevent("Requesting X11 forwarding");
8463 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
8465 ssh2_pkt_addbool(pktout, 0); /* many connections */
8466 ssh2_pkt_addstring(pktout, ssh->x11auth->protoname);
8467 ssh2_pkt_addstring(pktout, ssh->x11auth->datastring);
8468 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
8469 ssh2_pkt_send(ssh, pktout);
8471 /* Wait to be called back with either a response packet, or NULL
8472 * meaning clean up and free our data */
8476 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8477 logevent("X11 forwarding enabled");
8478 ssh->X11_fwd_enabled = TRUE;
8480 logevent("X11 forwarding refused");
8486 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
8489 struct ssh2_setup_agent_state {
8493 struct Packet *pktout;
8494 crStateP(ssh2_setup_agent_state, ctx);
8498 logevent("Requesting OpenSSH-style agent forwarding");
8499 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
8500 ssh2_setup_agent, s);
8501 ssh2_pkt_send(ssh, pktout);
8503 /* Wait to be called back with either a response packet, or NULL
8504 * meaning clean up and free our data */
8508 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8509 logevent("Agent forwarding enabled");
8510 ssh->agentfwd_enabled = TRUE;
8512 logevent("Agent forwarding refused");
8518 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
8521 struct ssh2_setup_pty_state {
8525 struct Packet *pktout;
8526 crStateP(ssh2_setup_pty_state, ctx);
8530 /* Unpick the terminal-speed string. */
8531 /* XXX perhaps we should allow no speeds to be sent. */
8532 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
8533 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
8534 /* Build the pty request. */
8535 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
8537 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
8538 ssh2_pkt_adduint32(pktout, ssh->term_width);
8539 ssh2_pkt_adduint32(pktout, ssh->term_height);
8540 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
8541 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
8542 ssh2_pkt_addstring_start(pktout);
8543 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
8544 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
8545 ssh2_pkt_adduint32(pktout, ssh->ispeed);
8546 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
8547 ssh2_pkt_adduint32(pktout, ssh->ospeed);
8548 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
8549 ssh2_pkt_send(ssh, pktout);
8550 ssh->state = SSH_STATE_INTERMED;
8552 /* Wait to be called back with either a response packet, or NULL
8553 * meaning clean up and free our data */
8557 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8558 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
8559 ssh->ospeed, ssh->ispeed);
8560 ssh->got_pty = TRUE;
8562 c_write_str(ssh, "Server refused to allocate pty\r\n");
8563 ssh->editing = ssh->echoing = 1;
8570 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
8573 struct ssh2_setup_env_state {
8575 int num_env, env_left, env_ok;
8578 struct Packet *pktout;
8579 crStateP(ssh2_setup_env_state, ctx);
8584 * Send environment variables.
8586 * Simplest thing here is to send all the requests at once, and
8587 * then wait for a whole bunch of successes or failures.
8593 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
8595 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
8596 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
8597 ssh2_pkt_addstring(pktout, key);
8598 ssh2_pkt_addstring(pktout, val);
8599 ssh2_pkt_send(ssh, pktout);
8604 logeventf(ssh, "Sent %d environment variables", s->num_env);
8609 s->env_left = s->num_env;
8611 while (s->env_left > 0) {
8612 /* Wait to be called back with either a response packet,
8613 * or NULL meaning clean up and free our data */
8615 if (!pktin) goto out;
8616 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
8621 if (s->env_ok == s->num_env) {
8622 logevent("All environment variables successfully set");
8623 } else if (s->env_ok == 0) {
8624 logevent("All environment variables refused");
8625 c_write_str(ssh, "Server refused to set environment variables\r\n");
8627 logeventf(ssh, "%d environment variables refused",
8628 s->num_env - s->env_ok);
8629 c_write_str(ssh, "Server refused to set all environment variables\r\n");
8637 * Handle the SSH-2 userauth and connection layers.
8639 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
8641 do_ssh2_authconn(ssh, NULL, 0, pktin);
8644 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
8648 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
8651 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
8652 struct Packet *pktin)
8654 struct do_ssh2_authconn_state {
8658 AUTH_TYPE_PUBLICKEY,
8659 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
8660 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
8662 AUTH_TYPE_GSSAPI, /* always QUIET */
8663 AUTH_TYPE_KEYBOARD_INTERACTIVE,
8664 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
8666 int done_service_req;
8667 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
8668 int tried_pubkey_config, done_agent;
8673 int kbd_inter_refused;
8674 int we_are_in, userauth_success;
8675 prompts_t *cur_prompt;
8680 void *publickey_blob;
8681 int publickey_bloblen;
8682 int publickey_encrypted;
8683 char *publickey_algorithm;
8684 char *publickey_comment;
8685 unsigned char agent_request[5], *agent_response, *agentp;
8686 int agent_responselen;
8687 unsigned char *pkblob_in_agent;
8689 char *pkblob, *alg, *commentp;
8690 int pklen, alglen, commentlen;
8691 int siglen, retlen, len;
8692 char *q, *agentreq, *ret;
8694 struct Packet *pktout;
8697 struct ssh_gss_library *gsslib;
8698 Ssh_gss_ctx gss_ctx;
8699 Ssh_gss_buf gss_buf;
8700 Ssh_gss_buf gss_rcvtok, gss_sndtok;
8701 Ssh_gss_name gss_srv_name;
8702 Ssh_gss_stat gss_stat;
8705 crState(do_ssh2_authconn_state);
8709 /* Register as a handler for all the messages this coroutine handles. */
8710 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
8711 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
8712 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
8713 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
8714 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
8715 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
8716 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
8717 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
8718 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
8719 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
8720 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
8721 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
8722 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
8723 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
8724 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
8725 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
8726 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
8727 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
8728 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
8729 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
8731 s->done_service_req = FALSE;
8732 s->we_are_in = s->userauth_success = FALSE;
8733 s->agent_response = NULL;
8735 s->tried_gssapi = FALSE;
8738 if (!ssh->bare_connection) {
8739 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
8741 * Request userauth protocol, and await a response to it.
8743 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8744 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
8745 ssh2_pkt_send(ssh, s->pktout);
8746 crWaitUntilV(pktin);
8747 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
8748 s->done_service_req = TRUE;
8750 if (!s->done_service_req) {
8752 * Request connection protocol directly, without authentication.
8754 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8755 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8756 ssh2_pkt_send(ssh, s->pktout);
8757 crWaitUntilV(pktin);
8758 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
8759 s->we_are_in = TRUE; /* no auth required */
8761 bombout(("Server refused service request"));
8766 s->we_are_in = TRUE;
8769 /* Arrange to be able to deal with any BANNERs that come in.
8770 * (We do this now as packets may come in during the next bit.) */
8771 bufchain_init(&ssh->banner);
8772 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
8773 ssh2_msg_userauth_banner;
8776 * Misc one-time setup for authentication.
8778 s->publickey_blob = NULL;
8779 if (!s->we_are_in) {
8782 * Load the public half of any configured public key file
8785 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
8786 if (!filename_is_null(s->keyfile)) {
8788 logeventf(ssh, "Reading private key file \"%.150s\"",
8789 filename_to_str(s->keyfile));
8790 keytype = key_type(s->keyfile);
8791 if (keytype == SSH_KEYTYPE_SSH2) {
8794 ssh2_userkey_loadpub(s->keyfile,
8795 &s->publickey_algorithm,
8796 &s->publickey_bloblen,
8797 &s->publickey_comment, &error);
8798 if (s->publickey_blob) {
8799 s->publickey_encrypted =
8800 ssh2_userkey_encrypted(s->keyfile, NULL);
8803 logeventf(ssh, "Unable to load private key (%s)",
8805 msgbuf = dupprintf("Unable to load private key file "
8806 "\"%.150s\" (%s)\r\n",
8807 filename_to_str(s->keyfile),
8809 c_write_str(ssh, msgbuf);
8814 logeventf(ssh, "Unable to use this key file (%s)",
8815 key_type_to_str(keytype));
8816 msgbuf = dupprintf("Unable to use key file \"%.150s\""
8818 filename_to_str(s->keyfile),
8819 key_type_to_str(keytype));
8820 c_write_str(ssh, msgbuf);
8822 s->publickey_blob = NULL;
8827 * Find out about any keys Pageant has (but if there's a
8828 * public key configured, filter out all others).
8831 s->agent_response = NULL;
8832 s->pkblob_in_agent = NULL;
8833 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
8837 logevent("Pageant is running. Requesting keys.");
8839 /* Request the keys held by the agent. */
8840 PUT_32BIT(s->agent_request, 1);
8841 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
8842 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
8843 ssh_agent_callback, ssh)) {
8847 bombout(("Unexpected data from server while"
8848 " waiting for agent response"));
8851 } while (pktin || inlen > 0);
8852 r = ssh->agent_response;
8853 s->agent_responselen = ssh->agent_response_len;
8855 s->agent_response = (unsigned char *) r;
8856 if (s->agent_response && s->agent_responselen >= 5 &&
8857 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
8860 p = s->agent_response + 5;
8861 s->nkeys = toint(GET_32BIT(p));
8864 * Vet the Pageant response to ensure that the key
8865 * count and blob lengths make sense.
8868 logeventf(ssh, "Pageant response contained a negative"
8869 " key count %d", s->nkeys);
8871 goto done_agent_query;
8873 unsigned char *q = p + 4;
8874 int lenleft = s->agent_responselen - 5 - 4;
8876 for (keyi = 0; keyi < s->nkeys; keyi++) {
8877 int bloblen, commentlen;
8879 logeventf(ssh, "Pageant response was truncated");
8881 goto done_agent_query;
8883 bloblen = toint(GET_32BIT(q));
8884 if (bloblen < 0 || bloblen > lenleft) {
8885 logeventf(ssh, "Pageant response was truncated");
8887 goto done_agent_query;
8889 lenleft -= 4 + bloblen;
8891 commentlen = toint(GET_32BIT(q));
8892 if (commentlen < 0 || commentlen > lenleft) {
8893 logeventf(ssh, "Pageant response was truncated");
8895 goto done_agent_query;
8897 lenleft -= 4 + commentlen;
8898 q += 4 + commentlen;
8903 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
8904 if (s->publickey_blob) {
8905 /* See if configured key is in agent. */
8906 for (keyi = 0; keyi < s->nkeys; keyi++) {
8907 s->pklen = toint(GET_32BIT(p));
8908 if (s->pklen == s->publickey_bloblen &&
8909 !memcmp(p+4, s->publickey_blob,
8910 s->publickey_bloblen)) {
8911 logeventf(ssh, "Pageant key #%d matches "
8912 "configured key file", keyi);
8914 s->pkblob_in_agent = p;
8918 p += toint(GET_32BIT(p)) + 4; /* comment */
8920 if (!s->pkblob_in_agent) {
8921 logevent("Configured key file not in Pageant");
8926 logevent("Failed to get reply from Pageant");
8934 * We repeat this whole loop, including the username prompt,
8935 * until we manage a successful authentication. If the user
8936 * types the wrong _password_, they can be sent back to the
8937 * beginning to try another username, if this is configured on.
8938 * (If they specify a username in the config, they are never
8939 * asked, even if they do give a wrong password.)
8941 * I think this best serves the needs of
8943 * - the people who have no configuration, no keys, and just
8944 * want to try repeated (username,password) pairs until they
8945 * type both correctly
8947 * - people who have keys and configuration but occasionally
8948 * need to fall back to passwords
8950 * - people with a key held in Pageant, who might not have
8951 * logged in to a particular machine before; so they want to
8952 * type a username, and then _either_ their key will be
8953 * accepted, _or_ they will type a password. If they mistype
8954 * the username they will want to be able to get back and
8957 s->got_username = FALSE;
8958 while (!s->we_are_in) {
8962 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
8964 * We got a username last time round this loop, and
8965 * with change_username turned off we don't try to get
8968 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
8969 int ret; /* need not be kept over crReturn */
8970 s->cur_prompt = new_prompts(ssh->frontend);
8971 s->cur_prompt->to_server = TRUE;
8972 s->cur_prompt->name = dupstr("SSH login name");
8973 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
8974 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8977 crWaitUntilV(!pktin);
8978 ret = get_userpass_input(s->cur_prompt, in, inlen);
8983 * get_userpass_input() failed to get a username.
8986 free_prompts(s->cur_prompt);
8987 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
8990 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
8991 free_prompts(s->cur_prompt);
8994 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
8995 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
8996 c_write_str(ssh, stuff);
9000 s->got_username = TRUE;
9003 * Send an authentication request using method "none": (a)
9004 * just in case it succeeds, and (b) so that we know what
9005 * authentication methods we can usefully try next.
9007 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9009 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9010 ssh2_pkt_addstring(s->pktout, ssh->username);
9011 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
9012 ssh2_pkt_addstring(s->pktout, "none"); /* method */
9013 ssh2_pkt_send(ssh, s->pktout);
9014 s->type = AUTH_TYPE_NONE;
9016 s->we_are_in = FALSE;
9018 s->tried_pubkey_config = FALSE;
9019 s->kbd_inter_refused = FALSE;
9021 /* Reset agent request state. */
9022 s->done_agent = FALSE;
9023 if (s->agent_response) {
9024 if (s->pkblob_in_agent) {
9025 s->agentp = s->pkblob_in_agent;
9027 s->agentp = s->agent_response + 5 + 4;
9033 char *methods = NULL;
9037 * Wait for the result of the last authentication request.
9040 crWaitUntilV(pktin);
9042 * Now is a convenient point to spew any banner material
9043 * that we've accumulated. (This should ensure that when
9044 * we exit the auth loop, we haven't any left to deal
9048 int size = bufchain_size(&ssh->banner);
9050 * Don't show the banner if we're operating in
9051 * non-verbose non-interactive mode. (It's probably
9052 * a script, which means nobody will read the
9053 * banner _anyway_, and moreover the printing of
9054 * the banner will screw up processing on the
9055 * output of (say) plink.)
9057 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
9058 char *banner = snewn(size, char);
9059 bufchain_fetch(&ssh->banner, banner, size);
9060 c_write_untrusted(ssh, banner, size);
9063 bufchain_clear(&ssh->banner);
9065 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
9066 logevent("Access granted");
9067 s->we_are_in = s->userauth_success = TRUE;
9071 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
9072 bombout(("Strange packet received during authentication: "
9073 "type %d", pktin->type));
9080 * OK, we're now sitting on a USERAUTH_FAILURE message, so
9081 * we can look at the string in it and know what we can
9082 * helpfully try next.
9084 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
9085 ssh_pkt_getstring(pktin, &methods, &methlen);
9086 if (!ssh2_pkt_getbool(pktin)) {
9088 * We have received an unequivocal Access
9089 * Denied. This can translate to a variety of
9090 * messages, or no message at all.
9092 * For forms of authentication which are attempted
9093 * implicitly, by which I mean without printing
9094 * anything in the window indicating that we're
9095 * trying them, we should never print 'Access
9098 * If we do print a message saying that we're
9099 * attempting some kind of authentication, it's OK
9100 * to print a followup message saying it failed -
9101 * but the message may sometimes be more specific
9102 * than simply 'Access denied'.
9104 * Additionally, if we'd just tried password
9105 * authentication, we should break out of this
9106 * whole loop so as to go back to the username
9107 * prompt (iff we're configured to allow
9108 * username change attempts).
9110 if (s->type == AUTH_TYPE_NONE) {
9112 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
9113 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
9114 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
9115 c_write_str(ssh, "Server refused our key\r\n");
9116 logevent("Server refused our key");
9117 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
9118 /* This _shouldn't_ happen except by a
9119 * protocol bug causing client and server to
9120 * disagree on what is a correct signature. */
9121 c_write_str(ssh, "Server refused public-key signature"
9122 " despite accepting key!\r\n");
9123 logevent("Server refused public-key signature"
9124 " despite accepting key!");
9125 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
9126 /* quiet, so no c_write */
9127 logevent("Server refused keyboard-interactive authentication");
9128 } else if (s->type==AUTH_TYPE_GSSAPI) {
9129 /* always quiet, so no c_write */
9130 /* also, the code down in the GSSAPI block has
9131 * already logged this in the Event Log */
9132 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
9133 logevent("Keyboard-interactive authentication failed");
9134 c_write_str(ssh, "Access denied\r\n");
9136 assert(s->type == AUTH_TYPE_PASSWORD);
9137 logevent("Password authentication failed");
9138 c_write_str(ssh, "Access denied\r\n");
9140 if (conf_get_int(ssh->conf, CONF_change_username)) {
9141 /* XXX perhaps we should allow
9142 * keyboard-interactive to do this too? */
9143 s->we_are_in = FALSE;
9148 c_write_str(ssh, "Further authentication required\r\n");
9149 logevent("Further authentication required");
9153 in_commasep_string("publickey", methods, methlen);
9155 in_commasep_string("password", methods, methlen);
9156 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
9157 in_commasep_string("keyboard-interactive", methods, methlen);
9160 ssh->gsslibs = ssh_gss_setup(ssh->conf);
9161 s->can_gssapi = conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
9162 in_commasep_string("gssapi-with-mic", methods, methlen) &&
9163 ssh->gsslibs->nlibraries > 0;
9167 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9169 if (s->can_pubkey && !s->done_agent && s->nkeys) {
9172 * Attempt public-key authentication using a key from Pageant.
9175 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9177 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
9179 /* Unpack key from agent response */
9180 s->pklen = toint(GET_32BIT(s->agentp));
9182 s->pkblob = (char *)s->agentp;
9183 s->agentp += s->pklen;
9184 s->alglen = toint(GET_32BIT(s->pkblob));
9185 s->alg = s->pkblob + 4;
9186 s->commentlen = toint(GET_32BIT(s->agentp));
9188 s->commentp = (char *)s->agentp;
9189 s->agentp += s->commentlen;
9190 /* s->agentp now points at next key, if any */
9192 /* See if server will accept it */
9193 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9194 ssh2_pkt_addstring(s->pktout, ssh->username);
9195 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9196 /* service requested */
9197 ssh2_pkt_addstring(s->pktout, "publickey");
9199 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
9200 ssh2_pkt_addstring_start(s->pktout);
9201 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9202 ssh2_pkt_addstring_start(s->pktout);
9203 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9204 ssh2_pkt_send(ssh, s->pktout);
9205 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
9207 crWaitUntilV(pktin);
9208 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9210 /* Offer of key refused. */
9217 if (flags & FLAG_VERBOSE) {
9218 c_write_str(ssh, "Authenticating with "
9220 c_write(ssh, s->commentp, s->commentlen);
9221 c_write_str(ssh, "\" from agent\r\n");
9225 * Server is willing to accept the key.
9226 * Construct a SIGN_REQUEST.
9228 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9229 ssh2_pkt_addstring(s->pktout, ssh->username);
9230 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9231 /* service requested */
9232 ssh2_pkt_addstring(s->pktout, "publickey");
9234 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
9235 ssh2_pkt_addstring_start(s->pktout);
9236 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9237 ssh2_pkt_addstring_start(s->pktout);
9238 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9240 /* Ask agent for signature. */
9241 s->siglen = s->pktout->length - 5 + 4 +
9242 ssh->v2_session_id_len;
9243 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9245 s->len = 1; /* message type */
9246 s->len += 4 + s->pklen; /* key blob */
9247 s->len += 4 + s->siglen; /* data to sign */
9248 s->len += 4; /* flags */
9249 s->agentreq = snewn(4 + s->len, char);
9250 PUT_32BIT(s->agentreq, s->len);
9251 s->q = s->agentreq + 4;
9252 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
9253 PUT_32BIT(s->q, s->pklen);
9255 memcpy(s->q, s->pkblob, s->pklen);
9257 PUT_32BIT(s->q, s->siglen);
9259 /* Now the data to be signed... */
9260 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9261 PUT_32BIT(s->q, ssh->v2_session_id_len);
9264 memcpy(s->q, ssh->v2_session_id,
9265 ssh->v2_session_id_len);
9266 s->q += ssh->v2_session_id_len;
9267 memcpy(s->q, s->pktout->data + 5,
9268 s->pktout->length - 5);
9269 s->q += s->pktout->length - 5;
9270 /* And finally the (zero) flags word. */
9272 if (!agent_query(s->agentreq, s->len + 4,
9274 ssh_agent_callback, ssh)) {
9278 bombout(("Unexpected data from server"
9279 " while waiting for agent"
9283 } while (pktin || inlen > 0);
9284 vret = ssh->agent_response;
9285 s->retlen = ssh->agent_response_len;
9290 if (s->retlen >= 9 &&
9291 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
9292 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
9293 logevent("Sending Pageant's response");
9294 ssh2_add_sigblob(ssh, s->pktout,
9295 s->pkblob, s->pklen,
9297 GET_32BIT(s->ret + 5));
9298 ssh2_pkt_send(ssh, s->pktout);
9299 s->type = AUTH_TYPE_PUBLICKEY;
9301 /* FIXME: less drastic response */
9302 bombout(("Pageant failed to answer challenge"));
9308 /* Do we have any keys left to try? */
9309 if (s->pkblob_in_agent) {
9310 s->done_agent = TRUE;
9311 s->tried_pubkey_config = TRUE;
9314 if (s->keyi >= s->nkeys)
9315 s->done_agent = TRUE;
9318 } else if (s->can_pubkey && s->publickey_blob &&
9319 !s->tried_pubkey_config) {
9321 struct ssh2_userkey *key; /* not live over crReturn */
9322 char *passphrase; /* not live over crReturn */
9324 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9326 s->tried_pubkey_config = TRUE;
9329 * Try the public key supplied in the configuration.
9331 * First, offer the public blob to see if the server is
9332 * willing to accept it.
9334 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9335 ssh2_pkt_addstring(s->pktout, ssh->username);
9336 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9337 /* service requested */
9338 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
9339 ssh2_pkt_addbool(s->pktout, FALSE);
9340 /* no signature included */
9341 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
9342 ssh2_pkt_addstring_start(s->pktout);
9343 ssh2_pkt_addstring_data(s->pktout,
9344 (char *)s->publickey_blob,
9345 s->publickey_bloblen);
9346 ssh2_pkt_send(ssh, s->pktout);
9347 logevent("Offered public key");
9349 crWaitUntilV(pktin);
9350 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9351 /* Key refused. Give up. */
9352 s->gotit = TRUE; /* reconsider message next loop */
9353 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
9354 continue; /* process this new message */
9356 logevent("Offer of public key accepted");
9359 * Actually attempt a serious authentication using
9362 if (flags & FLAG_VERBOSE) {
9363 c_write_str(ssh, "Authenticating with public key \"");
9364 c_write_str(ssh, s->publickey_comment);
9365 c_write_str(ssh, "\"\r\n");
9369 const char *error; /* not live over crReturn */
9370 if (s->publickey_encrypted) {
9372 * Get a passphrase from the user.
9374 int ret; /* need not be kept over crReturn */
9375 s->cur_prompt = new_prompts(ssh->frontend);
9376 s->cur_prompt->to_server = FALSE;
9377 s->cur_prompt->name = dupstr("SSH key passphrase");
9378 add_prompt(s->cur_prompt,
9379 dupprintf("Passphrase for key \"%.100s\": ",
9380 s->publickey_comment),
9382 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9385 crWaitUntilV(!pktin);
9386 ret = get_userpass_input(s->cur_prompt,
9391 /* Failed to get a passphrase. Terminate. */
9392 free_prompts(s->cur_prompt);
9393 ssh_disconnect(ssh, NULL,
9394 "Unable to authenticate",
9395 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9400 dupstr(s->cur_prompt->prompts[0]->result);
9401 free_prompts(s->cur_prompt);
9403 passphrase = NULL; /* no passphrase needed */
9407 * Try decrypting the key.
9409 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9410 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
9412 /* burn the evidence */
9413 smemclr(passphrase, strlen(passphrase));
9416 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
9418 (key == SSH2_WRONG_PASSPHRASE)) {
9419 c_write_str(ssh, "Wrong passphrase\r\n");
9421 /* and loop again */
9423 c_write_str(ssh, "Unable to load private key (");
9424 c_write_str(ssh, error);
9425 c_write_str(ssh, ")\r\n");
9427 break; /* try something else */
9433 unsigned char *pkblob, *sigblob, *sigdata;
9434 int pkblob_len, sigblob_len, sigdata_len;
9438 * We have loaded the private key and the server
9439 * has announced that it's willing to accept it.
9440 * Hallelujah. Generate a signature and send it.
9442 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9443 ssh2_pkt_addstring(s->pktout, ssh->username);
9444 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9445 /* service requested */
9446 ssh2_pkt_addstring(s->pktout, "publickey");
9448 ssh2_pkt_addbool(s->pktout, TRUE);
9449 /* signature follows */
9450 ssh2_pkt_addstring(s->pktout, key->alg->name);
9451 pkblob = key->alg->public_blob(key->data,
9453 ssh2_pkt_addstring_start(s->pktout);
9454 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
9458 * The data to be signed is:
9462 * followed by everything so far placed in the
9465 sigdata_len = s->pktout->length - 5 + 4 +
9466 ssh->v2_session_id_len;
9467 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9469 sigdata = snewn(sigdata_len, unsigned char);
9471 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9472 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
9475 memcpy(sigdata+p, ssh->v2_session_id,
9476 ssh->v2_session_id_len);
9477 p += ssh->v2_session_id_len;
9478 memcpy(sigdata+p, s->pktout->data + 5,
9479 s->pktout->length - 5);
9480 p += s->pktout->length - 5;
9481 assert(p == sigdata_len);
9482 sigblob = key->alg->sign(key->data, (char *)sigdata,
9483 sigdata_len, &sigblob_len);
9484 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
9485 sigblob, sigblob_len);
9490 ssh2_pkt_send(ssh, s->pktout);
9491 logevent("Sent public key signature");
9492 s->type = AUTH_TYPE_PUBLICKEY;
9493 key->alg->freekey(key->data);
9497 } else if (s->can_gssapi && !s->tried_gssapi) {
9499 /* GSSAPI Authentication */
9504 s->type = AUTH_TYPE_GSSAPI;
9505 s->tried_gssapi = TRUE;
9507 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
9510 * Pick the highest GSS library on the preference
9516 for (i = 0; i < ngsslibs; i++) {
9517 int want_id = conf_get_int_int(ssh->conf,
9518 CONF_ssh_gsslist, i);
9519 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
9520 if (ssh->gsslibs->libraries[j].id == want_id) {
9521 s->gsslib = &ssh->gsslibs->libraries[j];
9522 goto got_gsslib; /* double break */
9527 * We always expect to have found something in
9528 * the above loop: we only came here if there
9529 * was at least one viable GSS library, and the
9530 * preference list should always mention
9531 * everything and only change the order.
9536 if (s->gsslib->gsslogmsg)
9537 logevent(s->gsslib->gsslogmsg);
9539 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
9540 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9541 ssh2_pkt_addstring(s->pktout, ssh->username);
9542 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9543 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
9544 logevent("Attempting GSSAPI authentication");
9546 /* add mechanism info */
9547 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
9549 /* number of GSSAPI mechanisms */
9550 ssh2_pkt_adduint32(s->pktout,1);
9552 /* length of OID + 2 */
9553 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
9554 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
9557 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
9559 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
9561 ssh2_pkt_send(ssh, s->pktout);
9562 crWaitUntilV(pktin);
9563 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
9564 logevent("GSSAPI authentication request refused");
9568 /* check returned packet ... */
9570 ssh_pkt_getstring(pktin, &data, &len);
9571 s->gss_rcvtok.value = data;
9572 s->gss_rcvtok.length = len;
9573 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
9574 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
9575 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
9576 memcmp((char *)s->gss_rcvtok.value + 2,
9577 s->gss_buf.value,s->gss_buf.length) ) {
9578 logevent("GSSAPI authentication - wrong response from server");
9582 /* now start running */
9583 s->gss_stat = s->gsslib->import_name(s->gsslib,
9586 if (s->gss_stat != SSH_GSS_OK) {
9587 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
9588 logevent("GSSAPI import name failed - Bad service name");
9590 logevent("GSSAPI import name failed");
9594 /* fetch TGT into GSS engine */
9595 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
9597 if (s->gss_stat != SSH_GSS_OK) {
9598 logevent("GSSAPI authentication failed to get credentials");
9599 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9603 /* initial tokens are empty */
9604 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
9605 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
9607 /* now enter the loop */
9609 s->gss_stat = s->gsslib->init_sec_context
9613 conf_get_int(ssh->conf, CONF_gssapifwd),
9617 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
9618 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
9619 logevent("GSSAPI authentication initialisation failed");
9621 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
9622 &s->gss_buf) == SSH_GSS_OK) {
9623 logevent(s->gss_buf.value);
9624 sfree(s->gss_buf.value);
9629 logevent("GSSAPI authentication initialised");
9631 /* Client and server now exchange tokens until GSSAPI
9632 * no longer says CONTINUE_NEEDED */
9634 if (s->gss_sndtok.length != 0) {
9635 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
9636 ssh_pkt_addstring_start(s->pktout);
9637 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
9638 ssh2_pkt_send(ssh, s->pktout);
9639 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
9642 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
9643 crWaitUntilV(pktin);
9644 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
9645 logevent("GSSAPI authentication - bad server response");
9646 s->gss_stat = SSH_GSS_FAILURE;
9649 ssh_pkt_getstring(pktin, &data, &len);
9650 s->gss_rcvtok.value = data;
9651 s->gss_rcvtok.length = len;
9653 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
9655 if (s->gss_stat != SSH_GSS_OK) {
9656 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9657 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9660 logevent("GSSAPI authentication loop finished OK");
9662 /* Now send the MIC */
9664 s->pktout = ssh2_pkt_init(0);
9665 micoffset = s->pktout->length;
9666 ssh_pkt_addstring_start(s->pktout);
9667 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
9668 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
9669 ssh_pkt_addstring(s->pktout, ssh->username);
9670 ssh_pkt_addstring(s->pktout, "ssh-connection");
9671 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
9673 s->gss_buf.value = (char *)s->pktout->data + micoffset;
9674 s->gss_buf.length = s->pktout->length - micoffset;
9676 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
9677 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
9678 ssh_pkt_addstring_start(s->pktout);
9679 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
9680 ssh2_pkt_send(ssh, s->pktout);
9681 s->gsslib->free_mic(s->gsslib, &mic);
9685 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9686 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9689 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
9692 * Keyboard-interactive authentication.
9695 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
9697 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
9699 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9700 ssh2_pkt_addstring(s->pktout, ssh->username);
9701 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9702 /* service requested */
9703 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
9705 ssh2_pkt_addstring(s->pktout, ""); /* lang */
9706 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
9707 ssh2_pkt_send(ssh, s->pktout);
9709 logevent("Attempting keyboard-interactive authentication");
9711 crWaitUntilV(pktin);
9712 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
9713 /* Server is not willing to do keyboard-interactive
9714 * at all (or, bizarrely but legally, accepts the
9715 * user without actually issuing any prompts).
9716 * Give up on it entirely. */
9718 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
9719 s->kbd_inter_refused = TRUE; /* don't try it again */
9724 * Loop while the server continues to send INFO_REQUESTs.
9726 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
9728 char *name, *inst, *lang;
9729 int name_len, inst_len, lang_len;
9733 * We've got a fresh USERAUTH_INFO_REQUEST.
9734 * Get the preamble and start building a prompt.
9736 ssh_pkt_getstring(pktin, &name, &name_len);
9737 ssh_pkt_getstring(pktin, &inst, &inst_len);
9738 ssh_pkt_getstring(pktin, &lang, &lang_len);
9739 s->cur_prompt = new_prompts(ssh->frontend);
9740 s->cur_prompt->to_server = TRUE;
9743 * Get any prompt(s) from the packet.
9745 s->num_prompts = ssh_pkt_getuint32(pktin);
9746 for (i = 0; i < s->num_prompts; i++) {
9750 static char noprompt[] =
9751 "<server failed to send prompt>: ";
9753 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9754 echo = ssh2_pkt_getbool(pktin);
9757 prompt_len = lenof(noprompt)-1;
9759 add_prompt(s->cur_prompt,
9760 dupprintf("%.*s", prompt_len, prompt),
9765 /* FIXME: better prefix to distinguish from
9767 s->cur_prompt->name =
9768 dupprintf("SSH server: %.*s", name_len, name);
9769 s->cur_prompt->name_reqd = TRUE;
9771 s->cur_prompt->name =
9772 dupstr("SSH server authentication");
9773 s->cur_prompt->name_reqd = FALSE;
9775 /* We add a prefix to try to make it clear that a prompt
9776 * has come from the server.
9777 * FIXME: ugly to print "Using..." in prompt _every_
9778 * time round. Can this be done more subtly? */
9779 /* Special case: for reasons best known to themselves,
9780 * some servers send k-i requests with no prompts and
9781 * nothing to display. Keep quiet in this case. */
9782 if (s->num_prompts || name_len || inst_len) {
9783 s->cur_prompt->instruction =
9784 dupprintf("Using keyboard-interactive authentication.%s%.*s",
9785 inst_len ? "\n" : "", inst_len, inst);
9786 s->cur_prompt->instr_reqd = TRUE;
9788 s->cur_prompt->instr_reqd = FALSE;
9792 * Display any instructions, and get the user's
9796 int ret; /* not live over crReturn */
9797 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9800 crWaitUntilV(!pktin);
9801 ret = get_userpass_input(s->cur_prompt, in, inlen);
9806 * Failed to get responses. Terminate.
9808 free_prompts(s->cur_prompt);
9809 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9810 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9817 * Send the response(s) to the server.
9819 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
9820 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
9821 for (i=0; i < s->num_prompts; i++) {
9822 ssh2_pkt_addstring(s->pktout,
9823 s->cur_prompt->prompts[i]->result);
9825 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9828 * Free the prompts structure from this iteration.
9829 * If there's another, a new one will be allocated
9830 * when we return to the top of this while loop.
9832 free_prompts(s->cur_prompt);
9835 * Get the next packet in case it's another
9838 crWaitUntilV(pktin);
9843 * We should have SUCCESS or FAILURE now.
9847 } else if (s->can_passwd) {
9850 * Plain old password authentication.
9852 int ret; /* not live over crReturn */
9853 int changereq_first_time; /* not live over crReturn */
9855 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
9857 s->cur_prompt = new_prompts(ssh->frontend);
9858 s->cur_prompt->to_server = TRUE;
9859 s->cur_prompt->name = dupstr("SSH password");
9860 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
9865 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9868 crWaitUntilV(!pktin);
9869 ret = get_userpass_input(s->cur_prompt, in, inlen);
9874 * Failed to get responses. Terminate.
9876 free_prompts(s->cur_prompt);
9877 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9878 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9883 * Squirrel away the password. (We may need it later if
9884 * asked to change it.)
9886 s->password = dupstr(s->cur_prompt->prompts[0]->result);
9887 free_prompts(s->cur_prompt);
9890 * Send the password packet.
9892 * We pad out the password packet to 256 bytes to make
9893 * it harder for an attacker to find the length of the
9896 * Anyone using a password longer than 256 bytes
9897 * probably doesn't have much to worry about from
9898 * people who find out how long their password is!
9900 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9901 ssh2_pkt_addstring(s->pktout, ssh->username);
9902 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9903 /* service requested */
9904 ssh2_pkt_addstring(s->pktout, "password");
9905 ssh2_pkt_addbool(s->pktout, FALSE);
9906 ssh2_pkt_addstring(s->pktout, s->password);
9907 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9908 logevent("Sent password");
9909 s->type = AUTH_TYPE_PASSWORD;
9912 * Wait for next packet, in case it's a password change
9915 crWaitUntilV(pktin);
9916 changereq_first_time = TRUE;
9918 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
9921 * We're being asked for a new password
9922 * (perhaps not for the first time).
9923 * Loop until the server accepts it.
9926 int got_new = FALSE; /* not live over crReturn */
9927 char *prompt; /* not live over crReturn */
9928 int prompt_len; /* not live over crReturn */
9932 if (changereq_first_time)
9933 msg = "Server requested password change";
9935 msg = "Server rejected new password";
9937 c_write_str(ssh, msg);
9938 c_write_str(ssh, "\r\n");
9941 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9943 s->cur_prompt = new_prompts(ssh->frontend);
9944 s->cur_prompt->to_server = TRUE;
9945 s->cur_prompt->name = dupstr("New SSH password");
9946 s->cur_prompt->instruction =
9947 dupprintf("%.*s", prompt_len, prompt);
9948 s->cur_prompt->instr_reqd = TRUE;
9950 * There's no explicit requirement in the protocol
9951 * for the "old" passwords in the original and
9952 * password-change messages to be the same, and
9953 * apparently some Cisco kit supports password change
9954 * by the user entering a blank password originally
9955 * and the real password subsequently, so,
9956 * reluctantly, we prompt for the old password again.
9958 * (On the other hand, some servers don't even bother
9959 * to check this field.)
9961 add_prompt(s->cur_prompt,
9962 dupstr("Current password (blank for previously entered password): "),
9964 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
9966 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
9970 * Loop until the user manages to enter the same
9975 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9978 crWaitUntilV(!pktin);
9979 ret = get_userpass_input(s->cur_prompt, in, inlen);
9984 * Failed to get responses. Terminate.
9986 /* burn the evidence */
9987 free_prompts(s->cur_prompt);
9988 smemclr(s->password, strlen(s->password));
9990 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9991 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9997 * If the user specified a new original password
9998 * (IYSWIM), overwrite any previously specified
10000 * (A side effect is that the user doesn't have to
10001 * re-enter it if they louse up the new password.)
10003 if (s->cur_prompt->prompts[0]->result[0]) {
10004 smemclr(s->password, strlen(s->password));
10005 /* burn the evidence */
10006 sfree(s->password);
10008 dupstr(s->cur_prompt->prompts[0]->result);
10012 * Check the two new passwords match.
10014 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
10015 s->cur_prompt->prompts[2]->result)
10018 /* They don't. Silly user. */
10019 c_write_str(ssh, "Passwords do not match\r\n");
10024 * Send the new password (along with the old one).
10025 * (see above for padding rationale)
10027 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10028 ssh2_pkt_addstring(s->pktout, ssh->username);
10029 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10030 /* service requested */
10031 ssh2_pkt_addstring(s->pktout, "password");
10032 ssh2_pkt_addbool(s->pktout, TRUE);
10033 ssh2_pkt_addstring(s->pktout, s->password);
10034 ssh2_pkt_addstring(s->pktout,
10035 s->cur_prompt->prompts[1]->result);
10036 free_prompts(s->cur_prompt);
10037 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10038 logevent("Sent new password");
10041 * Now see what the server has to say about it.
10042 * (If it's CHANGEREQ again, it's not happy with the
10045 crWaitUntilV(pktin);
10046 changereq_first_time = FALSE;
10051 * We need to reexamine the current pktin at the top
10052 * of the loop. Either:
10053 * - we weren't asked to change password at all, in
10054 * which case it's a SUCCESS or FAILURE with the
10056 * - we sent a new password, and the server was
10057 * either OK with it (SUCCESS or FAILURE w/partial
10058 * success) or unhappy with the _old_ password
10059 * (FAILURE w/o partial success)
10060 * In any of these cases, we go back to the top of
10061 * the loop and start again.
10066 * We don't need the old password any more, in any
10067 * case. Burn the evidence.
10069 smemclr(s->password, strlen(s->password));
10070 sfree(s->password);
10073 char *str = dupprintf("No supported authentication methods available"
10074 " (server sent: %.*s)",
10077 ssh_disconnect(ssh, str,
10078 "No supported authentication methods available",
10079 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
10089 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
10091 /* Clear up various bits and pieces from authentication. */
10092 if (s->publickey_blob) {
10093 sfree(s->publickey_blob);
10094 sfree(s->publickey_comment);
10096 if (s->agent_response)
10097 sfree(s->agent_response);
10099 if (s->userauth_success && !ssh->bare_connection) {
10101 * We've just received USERAUTH_SUCCESS, and we haven't sent any
10102 * packets since. Signal the transport layer to consider enacting
10103 * delayed compression.
10105 * (Relying on we_are_in is not sufficient, as
10106 * draft-miller-secsh-compression-delayed is quite clear that it
10107 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
10108 * become set for other reasons.)
10110 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
10113 ssh->channels = newtree234(ssh_channelcmp);
10116 * Set up handlers for some connection protocol messages, so we
10117 * don't have to handle them repeatedly in this coroutine.
10119 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
10120 ssh2_msg_channel_window_adjust;
10121 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
10122 ssh2_msg_global_request;
10125 * Create the main session channel.
10127 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
10128 ssh->mainchan = NULL;
10130 ssh->mainchan = snew(struct ssh_channel);
10131 ssh->mainchan->ssh = ssh;
10132 ssh2_channel_init(ssh->mainchan);
10134 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
10136 * Just start a direct-tcpip channel and use it as the main
10139 ssh_send_port_open(ssh->mainchan,
10140 conf_get_str(ssh->conf, CONF_ssh_nc_host),
10141 conf_get_int(ssh->conf, CONF_ssh_nc_port),
10143 ssh->ncmode = TRUE;
10145 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
10146 logevent("Opening session as main channel");
10147 ssh2_pkt_send(ssh, s->pktout);
10148 ssh->ncmode = FALSE;
10150 crWaitUntilV(pktin);
10151 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
10152 bombout(("Server refused to open channel"));
10154 /* FIXME: error data comes back in FAILURE packet */
10156 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
10157 bombout(("Server's channel confirmation cited wrong channel"));
10160 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
10161 ssh->mainchan->halfopen = FALSE;
10162 ssh->mainchan->type = CHAN_MAINSESSION;
10163 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
10164 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
10165 add234(ssh->channels, ssh->mainchan);
10166 update_specials_menu(ssh->frontend);
10167 logevent("Opened main channel");
10171 * Now we have a channel, make dispatch table entries for
10172 * general channel-based messages.
10174 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
10175 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
10176 ssh2_msg_channel_data;
10177 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
10178 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
10179 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
10180 ssh2_msg_channel_open_confirmation;
10181 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
10182 ssh2_msg_channel_open_failure;
10183 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
10184 ssh2_msg_channel_request;
10185 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
10186 ssh2_msg_channel_open;
10187 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
10188 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
10191 * Now the connection protocol is properly up and running, with
10192 * all those dispatch table entries, so it's safe to let
10193 * downstreams start trying to open extra channels through us.
10195 if (ssh->connshare)
10196 share_activate(ssh->connshare, ssh->v_s);
10198 if (ssh->mainchan && ssh_is_simple(ssh)) {
10200 * This message indicates to the server that we promise
10201 * not to try to run any other channel in parallel with
10202 * this one, so it's safe for it to advertise a very large
10203 * window and leave the flow control to TCP.
10205 s->pktout = ssh2_chanreq_init(ssh->mainchan,
10206 "simple@putty.projects.tartarus.org",
10208 ssh2_pkt_send(ssh, s->pktout);
10212 * Enable port forwardings.
10214 ssh_setup_portfwd(ssh, ssh->conf);
10216 if (ssh->mainchan && !ssh->ncmode) {
10218 * Send the CHANNEL_REQUESTS for the main session channel.
10219 * Each one is handled by its own little asynchronous
10223 /* Potentially enable X11 forwarding. */
10224 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
10226 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
10228 if (!ssh->x11disp) {
10229 /* FIXME: return an error message from x11_setup_display */
10230 logevent("X11 forwarding not enabled: unable to"
10231 " initialise X display");
10233 ssh->x11auth = x11_invent_fake_auth
10234 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
10235 ssh->x11auth->disp = ssh->x11disp;
10237 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
10241 /* Potentially enable agent forwarding. */
10242 if (ssh_agent_forwarding_permitted(ssh))
10243 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
10245 /* Now allocate a pty for the session. */
10246 if (!conf_get_int(ssh->conf, CONF_nopty))
10247 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
10249 /* Send environment variables. */
10250 ssh2_setup_env(ssh->mainchan, NULL, NULL);
10253 * Start a shell or a remote command. We may have to attempt
10254 * this twice if the config data has provided a second choice
10261 if (ssh->fallback_cmd) {
10262 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
10263 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
10265 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
10266 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
10270 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
10271 ssh2_response_authconn, NULL);
10272 ssh2_pkt_addstring(s->pktout, cmd);
10274 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
10275 ssh2_response_authconn, NULL);
10276 ssh2_pkt_addstring(s->pktout, cmd);
10278 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
10279 ssh2_response_authconn, NULL);
10281 ssh2_pkt_send(ssh, s->pktout);
10283 crWaitUntilV(pktin);
10285 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
10286 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
10287 bombout(("Unexpected response to shell/command request:"
10288 " packet type %d", pktin->type));
10292 * We failed to start the command. If this is the
10293 * fallback command, we really are finished; if it's
10294 * not, and if the fallback command exists, try falling
10295 * back to it before complaining.
10297 if (!ssh->fallback_cmd &&
10298 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
10299 logevent("Primary command failed; attempting fallback");
10300 ssh->fallback_cmd = TRUE;
10303 bombout(("Server refused to start a shell/command"));
10306 logevent("Started a shell/command");
10311 ssh->editing = ssh->echoing = TRUE;
10314 ssh->state = SSH_STATE_SESSION;
10315 if (ssh->size_needed)
10316 ssh_size(ssh, ssh->term_width, ssh->term_height);
10317 if (ssh->eof_needed)
10318 ssh_special(ssh, TS_EOF);
10324 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
10329 s->try_send = FALSE;
10333 * _All_ the connection-layer packets we expect to
10334 * receive are now handled by the dispatch table.
10335 * Anything that reaches here must be bogus.
10338 bombout(("Strange packet received: type %d", pktin->type));
10340 } else if (ssh->mainchan) {
10342 * We have spare data. Add it to the channel buffer.
10344 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
10345 s->try_send = TRUE;
10349 struct ssh_channel *c;
10351 * Try to send data on all channels if we can.
10353 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
10354 ssh2_try_send_and_unthrottle(ssh, c);
10362 * Handlers for SSH-2 messages that might arrive at any moment.
10364 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
10366 /* log reason code in disconnect message */
10368 int reason, msglen;
10370 reason = ssh_pkt_getuint32(pktin);
10371 ssh_pkt_getstring(pktin, &msg, &msglen);
10373 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
10374 buf = dupprintf("Received disconnect message (%s)",
10375 ssh2_disconnect_reasons[reason]);
10377 buf = dupprintf("Received disconnect message (unknown"
10378 " type %d)", reason);
10382 buf = dupprintf("Disconnection message text: %.*s",
10385 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
10387 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
10388 ssh2_disconnect_reasons[reason] : "unknown",
10393 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
10395 /* log the debug message */
10399 /* XXX maybe we should actually take notice of the return value */
10400 ssh2_pkt_getbool(pktin);
10401 ssh_pkt_getstring(pktin, &msg, &msglen);
10403 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
10406 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
10408 do_ssh2_transport(ssh, NULL, 0, pktin);
10412 * Called if we receive a packet that isn't allowed by the protocol.
10413 * This only applies to packets whose meaning PuTTY understands.
10414 * Entirely unknown packets are handled below.
10416 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
10418 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
10419 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
10421 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
10425 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
10427 struct Packet *pktout;
10428 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
10429 ssh2_pkt_adduint32(pktout, pktin->sequence);
10431 * UNIMPLEMENTED messages MUST appear in the same order as the
10432 * messages they respond to. Hence, never queue them.
10434 ssh2_pkt_send_noqueue(ssh, pktout);
10438 * Handle the top-level SSH-2 protocol.
10440 static void ssh2_protocol_setup(Ssh ssh)
10445 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10447 for (i = 0; i < 256; i++)
10448 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10451 * Initially, we only accept transport messages (and a few generic
10452 * ones). do_ssh2_authconn will add more when it starts.
10453 * Messages that are understood but not currently acceptable go to
10454 * ssh2_msg_unexpected.
10456 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10457 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
10458 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
10459 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
10460 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
10461 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
10462 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
10463 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
10464 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
10465 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
10466 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
10467 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
10468 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
10469 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
10470 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
10471 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
10472 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
10473 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
10474 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
10475 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10476 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10477 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10478 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10479 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10480 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10481 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10482 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10483 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10484 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10485 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10486 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10487 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10488 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10491 * These messages have a special handler from the start.
10493 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10494 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
10495 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10498 static void ssh2_bare_connection_protocol_setup(Ssh ssh)
10503 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10505 for (i = 0; i < 256; i++)
10506 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10509 * Initially, we set all ssh-connection messages to 'unexpected';
10510 * do_ssh2_authconn will fill things in properly. We also handle a
10511 * couple of messages from the transport protocol which aren't
10512 * related to key exchange (UNIMPLEMENTED, IGNORE, DEBUG,
10515 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10516 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10517 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10518 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10519 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10520 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10521 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10522 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10523 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10524 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10525 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10526 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10527 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10528 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10530 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10533 * These messages have a special handler from the start.
10535 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10536 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore;
10537 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10540 static void ssh2_timer(void *ctx, unsigned long now)
10542 Ssh ssh = (Ssh)ctx;
10544 if (ssh->state == SSH_STATE_CLOSED)
10547 if (!ssh->kex_in_progress && !ssh->bare_connection &&
10548 conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
10549 now == ssh->next_rekey) {
10550 do_ssh2_transport(ssh, "timeout", -1, NULL);
10554 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
10555 struct Packet *pktin)
10557 unsigned char *in = (unsigned char *)vin;
10558 if (ssh->state == SSH_STATE_CLOSED)
10562 ssh->incoming_data_size += pktin->encrypted_len;
10563 if (!ssh->kex_in_progress &&
10564 ssh->max_data_size != 0 &&
10565 ssh->incoming_data_size > ssh->max_data_size)
10566 do_ssh2_transport(ssh, "too much data received", -1, NULL);
10570 ssh->packet_dispatch[pktin->type](ssh, pktin);
10571 else if (!ssh->protocol_initial_phase_done)
10572 do_ssh2_transport(ssh, in, inlen, pktin);
10574 do_ssh2_authconn(ssh, in, inlen, pktin);
10577 static void ssh2_bare_connection_protocol(Ssh ssh, void *vin, int inlen,
10578 struct Packet *pktin)
10580 unsigned char *in = (unsigned char *)vin;
10581 if (ssh->state == SSH_STATE_CLOSED)
10585 ssh->packet_dispatch[pktin->type](ssh, pktin);
10587 do_ssh2_authconn(ssh, in, inlen, pktin);
10590 static void ssh_cache_conf_values(Ssh ssh)
10592 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
10596 * Called to set up the connection.
10598 * Returns an error message, or NULL on success.
10600 static const char *ssh_init(void *frontend_handle, void **backend_handle,
10601 Conf *conf, char *host, int port, char **realhost,
10602 int nodelay, int keepalive)
10607 ssh = snew(struct ssh_tag);
10608 ssh->conf = conf_copy(conf);
10609 ssh_cache_conf_values(ssh);
10610 ssh->version = 0; /* when not ready yet */
10612 ssh->cipher = NULL;
10613 ssh->v1_cipher_ctx = NULL;
10614 ssh->crcda_ctx = NULL;
10615 ssh->cscipher = NULL;
10616 ssh->cs_cipher_ctx = NULL;
10617 ssh->sccipher = NULL;
10618 ssh->sc_cipher_ctx = NULL;
10620 ssh->cs_mac_ctx = NULL;
10622 ssh->sc_mac_ctx = NULL;
10623 ssh->cscomp = NULL;
10624 ssh->cs_comp_ctx = NULL;
10625 ssh->sccomp = NULL;
10626 ssh->sc_comp_ctx = NULL;
10628 ssh->kex_ctx = NULL;
10629 ssh->hostkey = NULL;
10630 ssh->hostkey_str = NULL;
10631 ssh->exitcode = -1;
10632 ssh->close_expected = FALSE;
10633 ssh->clean_exit = FALSE;
10634 ssh->state = SSH_STATE_PREPACKET;
10635 ssh->size_needed = FALSE;
10636 ssh->eof_needed = FALSE;
10638 ssh->logctx = NULL;
10639 ssh->deferred_send_data = NULL;
10640 ssh->deferred_len = 0;
10641 ssh->deferred_size = 0;
10642 ssh->fallback_cmd = 0;
10643 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
10644 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
10645 ssh->x11disp = NULL;
10646 ssh->x11auth = NULL;
10647 ssh->x11authtree = newtree234(x11_authcmp);
10648 ssh->v1_compressing = FALSE;
10649 ssh->v2_outgoing_sequence = 0;
10650 ssh->ssh1_rdpkt_crstate = 0;
10651 ssh->ssh2_rdpkt_crstate = 0;
10652 ssh->ssh2_bare_rdpkt_crstate = 0;
10653 ssh->ssh_gotdata_crstate = 0;
10654 ssh->do_ssh1_connection_crstate = 0;
10655 ssh->do_ssh_init_state = NULL;
10656 ssh->do_ssh_connection_init_state = NULL;
10657 ssh->do_ssh1_login_state = NULL;
10658 ssh->do_ssh2_transport_state = NULL;
10659 ssh->do_ssh2_authconn_state = NULL;
10662 ssh->mainchan = NULL;
10663 ssh->throttled_all = 0;
10664 ssh->v1_stdout_throttling = 0;
10666 ssh->queuelen = ssh->queuesize = 0;
10667 ssh->queueing = FALSE;
10668 ssh->qhead = ssh->qtail = NULL;
10669 ssh->deferred_rekey_reason = NULL;
10670 bufchain_init(&ssh->queued_incoming_data);
10671 ssh->frozen = FALSE;
10672 ssh->username = NULL;
10673 ssh->sent_console_eof = FALSE;
10674 ssh->got_pty = FALSE;
10675 ssh->bare_connection = FALSE;
10676 ssh->attempting_connshare = FALSE;
10678 *backend_handle = ssh;
10681 if (crypto_startup() == 0)
10682 return "Microsoft high encryption pack not installed!";
10685 ssh->frontend = frontend_handle;
10686 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
10687 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
10689 ssh->channels = NULL;
10690 ssh->rportfwds = NULL;
10691 ssh->portfwds = NULL;
10696 ssh->conn_throttle_count = 0;
10697 ssh->overall_bufsize = 0;
10698 ssh->fallback_cmd = 0;
10700 ssh->protocol = NULL;
10702 ssh->protocol_initial_phase_done = FALSE;
10704 ssh->pinger = NULL;
10706 ssh->incoming_data_size = ssh->outgoing_data_size =
10707 ssh->deferred_data_size = 0L;
10708 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10709 CONF_ssh_rekey_data));
10710 ssh->kex_in_progress = FALSE;
10713 ssh->gsslibs = NULL;
10716 random_ref(); /* do this now - may be needed by sharing setup code */
10718 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
10727 static void ssh_free(void *handle)
10729 Ssh ssh = (Ssh) handle;
10730 struct ssh_channel *c;
10731 struct ssh_rportfwd *pf;
10732 struct X11FakeAuth *auth;
10734 if (ssh->v1_cipher_ctx)
10735 ssh->cipher->free_context(ssh->v1_cipher_ctx);
10736 if (ssh->cs_cipher_ctx)
10737 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
10738 if (ssh->sc_cipher_ctx)
10739 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
10740 if (ssh->cs_mac_ctx)
10741 ssh->csmac->free_context(ssh->cs_mac_ctx);
10742 if (ssh->sc_mac_ctx)
10743 ssh->scmac->free_context(ssh->sc_mac_ctx);
10744 if (ssh->cs_comp_ctx) {
10746 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
10748 zlib_compress_cleanup(ssh->cs_comp_ctx);
10750 if (ssh->sc_comp_ctx) {
10752 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
10754 zlib_decompress_cleanup(ssh->sc_comp_ctx);
10757 dh_cleanup(ssh->kex_ctx);
10758 sfree(ssh->savedhost);
10760 while (ssh->queuelen-- > 0)
10761 ssh_free_packet(ssh->queue[ssh->queuelen]);
10764 while (ssh->qhead) {
10765 struct queued_handler *qh = ssh->qhead;
10766 ssh->qhead = qh->next;
10769 ssh->qhead = ssh->qtail = NULL;
10771 if (ssh->channels) {
10772 while ((c = delpos234(ssh->channels, 0)) != NULL) {
10775 if (c->u.x11.xconn != NULL)
10776 x11_close(c->u.x11.xconn);
10778 case CHAN_SOCKDATA:
10779 case CHAN_SOCKDATA_DORMANT:
10780 if (c->u.pfd.pf != NULL)
10781 pfd_close(c->u.pfd.pf);
10784 if (ssh->version == 2) {
10785 struct outstanding_channel_request *ocr, *nocr;
10786 ocr = c->v.v2.chanreq_head;
10788 ocr->handler(c, NULL, ocr->ctx);
10793 bufchain_clear(&c->v.v2.outbuffer);
10797 freetree234(ssh->channels);
10798 ssh->channels = NULL;
10801 if (ssh->connshare)
10802 sharestate_free(ssh->connshare);
10804 if (ssh->rportfwds) {
10805 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
10807 freetree234(ssh->rportfwds);
10808 ssh->rportfwds = NULL;
10810 sfree(ssh->deferred_send_data);
10812 x11_free_display(ssh->x11disp);
10813 while ((auth = delpos234(ssh->x11authtree, 0)) != NULL)
10814 x11_free_fake_auth(auth);
10815 freetree234(ssh->x11authtree);
10816 sfree(ssh->do_ssh_init_state);
10817 sfree(ssh->do_ssh1_login_state);
10818 sfree(ssh->do_ssh2_transport_state);
10819 sfree(ssh->do_ssh2_authconn_state);
10822 sfree(ssh->fullhostname);
10823 sfree(ssh->hostkey_str);
10824 if (ssh->crcda_ctx) {
10825 crcda_free_context(ssh->crcda_ctx);
10826 ssh->crcda_ctx = NULL;
10829 ssh_do_close(ssh, TRUE);
10830 expire_timer_context(ssh);
10832 pinger_free(ssh->pinger);
10833 bufchain_clear(&ssh->queued_incoming_data);
10834 sfree(ssh->username);
10835 conf_free(ssh->conf);
10838 ssh_gss_cleanup(ssh->gsslibs);
10846 * Reconfigure the SSH backend.
10848 static void ssh_reconfig(void *handle, Conf *conf)
10850 Ssh ssh = (Ssh) handle;
10851 char *rekeying = NULL, rekey_mandatory = FALSE;
10852 unsigned long old_max_data_size;
10855 pinger_reconfig(ssh->pinger, ssh->conf, conf);
10857 ssh_setup_portfwd(ssh, conf);
10859 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
10860 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
10862 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
10863 unsigned long now = GETTICKCOUNT();
10865 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
10866 rekeying = "timeout shortened";
10868 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
10872 old_max_data_size = ssh->max_data_size;
10873 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10874 CONF_ssh_rekey_data));
10875 if (old_max_data_size != ssh->max_data_size &&
10876 ssh->max_data_size != 0) {
10877 if (ssh->outgoing_data_size > ssh->max_data_size ||
10878 ssh->incoming_data_size > ssh->max_data_size)
10879 rekeying = "data limit lowered";
10882 if (conf_get_int(ssh->conf, CONF_compression) !=
10883 conf_get_int(conf, CONF_compression)) {
10884 rekeying = "compression setting changed";
10885 rekey_mandatory = TRUE;
10888 for (i = 0; i < CIPHER_MAX; i++)
10889 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
10890 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
10891 rekeying = "cipher settings changed";
10892 rekey_mandatory = TRUE;
10894 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
10895 conf_get_int(conf, CONF_ssh2_des_cbc)) {
10896 rekeying = "cipher settings changed";
10897 rekey_mandatory = TRUE;
10900 conf_free(ssh->conf);
10901 ssh->conf = conf_copy(conf);
10902 ssh_cache_conf_values(ssh);
10904 if (!ssh->bare_connection && rekeying) {
10905 if (!ssh->kex_in_progress) {
10906 do_ssh2_transport(ssh, rekeying, -1, NULL);
10907 } else if (rekey_mandatory) {
10908 ssh->deferred_rekey_reason = rekeying;
10914 * Called to send data down the SSH connection.
10916 static int ssh_send(void *handle, char *buf, int len)
10918 Ssh ssh = (Ssh) handle;
10920 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10923 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
10925 return ssh_sendbuffer(ssh);
10929 * Called to query the current amount of buffered stdin data.
10931 static int ssh_sendbuffer(void *handle)
10933 Ssh ssh = (Ssh) handle;
10934 int override_value;
10936 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10940 * If the SSH socket itself has backed up, add the total backup
10941 * size on that to any individual buffer on the stdin channel.
10943 override_value = 0;
10944 if (ssh->throttled_all)
10945 override_value = ssh->overall_bufsize;
10947 if (ssh->version == 1) {
10948 return override_value;
10949 } else if (ssh->version == 2) {
10950 if (!ssh->mainchan)
10951 return override_value;
10953 return (override_value +
10954 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
10961 * Called to set the size of the window from SSH's POV.
10963 static void ssh_size(void *handle, int width, int height)
10965 Ssh ssh = (Ssh) handle;
10966 struct Packet *pktout;
10968 ssh->term_width = width;
10969 ssh->term_height = height;
10971 switch (ssh->state) {
10972 case SSH_STATE_BEFORE_SIZE:
10973 case SSH_STATE_PREPACKET:
10974 case SSH_STATE_CLOSED:
10975 break; /* do nothing */
10976 case SSH_STATE_INTERMED:
10977 ssh->size_needed = TRUE; /* buffer for later */
10979 case SSH_STATE_SESSION:
10980 if (!conf_get_int(ssh->conf, CONF_nopty)) {
10981 if (ssh->version == 1) {
10982 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
10983 PKT_INT, ssh->term_height,
10984 PKT_INT, ssh->term_width,
10985 PKT_INT, 0, PKT_INT, 0, PKT_END);
10986 } else if (ssh->mainchan) {
10987 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
10989 ssh2_pkt_adduint32(pktout, ssh->term_width);
10990 ssh2_pkt_adduint32(pktout, ssh->term_height);
10991 ssh2_pkt_adduint32(pktout, 0);
10992 ssh2_pkt_adduint32(pktout, 0);
10993 ssh2_pkt_send(ssh, pktout);
11001 * Return a list of the special codes that make sense in this
11004 static const struct telnet_special *ssh_get_specials(void *handle)
11006 static const struct telnet_special ssh1_ignore_special[] = {
11007 {"IGNORE message", TS_NOP}
11009 static const struct telnet_special ssh2_ignore_special[] = {
11010 {"IGNORE message", TS_NOP},
11012 static const struct telnet_special ssh2_rekey_special[] = {
11013 {"Repeat key exchange", TS_REKEY},
11015 static const struct telnet_special ssh2_session_specials[] = {
11018 /* These are the signal names defined by RFC 4254.
11019 * They include all the ISO C signals, but are a subset of the POSIX
11020 * required signals. */
11021 {"SIGINT (Interrupt)", TS_SIGINT},
11022 {"SIGTERM (Terminate)", TS_SIGTERM},
11023 {"SIGKILL (Kill)", TS_SIGKILL},
11024 {"SIGQUIT (Quit)", TS_SIGQUIT},
11025 {"SIGHUP (Hangup)", TS_SIGHUP},
11026 {"More signals", TS_SUBMENU},
11027 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
11028 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
11029 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
11030 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
11031 {NULL, TS_EXITMENU}
11033 static const struct telnet_special specials_end[] = {
11034 {NULL, TS_EXITMENU}
11036 /* XXX review this length for any changes: */
11037 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
11038 lenof(ssh2_rekey_special) +
11039 lenof(ssh2_session_specials) +
11040 lenof(specials_end)];
11041 Ssh ssh = (Ssh) handle;
11043 #define ADD_SPECIALS(name) \
11045 assert((i + lenof(name)) <= lenof(ssh_specials)); \
11046 memcpy(&ssh_specials[i], name, sizeof name); \
11047 i += lenof(name); \
11050 if (ssh->version == 1) {
11051 /* Don't bother offering IGNORE if we've decided the remote
11052 * won't cope with it, since we wouldn't bother sending it if
11054 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11055 ADD_SPECIALS(ssh1_ignore_special);
11056 } else if (ssh->version == 2) {
11057 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
11058 ADD_SPECIALS(ssh2_ignore_special);
11059 if (!(ssh->remote_bugs & BUG_SSH2_REKEY) && !ssh->bare_connection)
11060 ADD_SPECIALS(ssh2_rekey_special);
11062 ADD_SPECIALS(ssh2_session_specials);
11063 } /* else we're not ready yet */
11066 ADD_SPECIALS(specials_end);
11067 return ssh_specials;
11071 #undef ADD_SPECIALS
11075 * Send special codes. TS_EOF is useful for `plink', so you
11076 * can send an EOF and collect resulting output (e.g. `plink
11079 static void ssh_special(void *handle, Telnet_Special code)
11081 Ssh ssh = (Ssh) handle;
11082 struct Packet *pktout;
11084 if (code == TS_EOF) {
11085 if (ssh->state != SSH_STATE_SESSION) {
11087 * Buffer the EOF in case we are pre-SESSION, so we can
11088 * send it as soon as we reach SESSION.
11090 if (code == TS_EOF)
11091 ssh->eof_needed = TRUE;
11094 if (ssh->version == 1) {
11095 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
11096 } else if (ssh->mainchan) {
11097 sshfwd_write_eof(ssh->mainchan);
11098 ssh->send_ok = 0; /* now stop trying to read from stdin */
11100 logevent("Sent EOF message");
11101 } else if (code == TS_PING || code == TS_NOP) {
11102 if (ssh->state == SSH_STATE_CLOSED
11103 || ssh->state == SSH_STATE_PREPACKET) return;
11104 if (ssh->version == 1) {
11105 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11106 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
11108 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
11109 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
11110 ssh2_pkt_addstring_start(pktout);
11111 ssh2_pkt_send_noqueue(ssh, pktout);
11114 } else if (code == TS_REKEY) {
11115 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11116 ssh->version == 2) {
11117 do_ssh2_transport(ssh, "at user request", -1, NULL);
11119 } else if (code == TS_BRK) {
11120 if (ssh->state == SSH_STATE_CLOSED
11121 || ssh->state == SSH_STATE_PREPACKET) return;
11122 if (ssh->version == 1) {
11123 logevent("Unable to send BREAK signal in SSH-1");
11124 } else if (ssh->mainchan) {
11125 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
11126 ssh2_pkt_adduint32(pktout, 0); /* default break length */
11127 ssh2_pkt_send(ssh, pktout);
11130 /* Is is a POSIX signal? */
11131 char *signame = NULL;
11132 if (code == TS_SIGABRT) signame = "ABRT";
11133 if (code == TS_SIGALRM) signame = "ALRM";
11134 if (code == TS_SIGFPE) signame = "FPE";
11135 if (code == TS_SIGHUP) signame = "HUP";
11136 if (code == TS_SIGILL) signame = "ILL";
11137 if (code == TS_SIGINT) signame = "INT";
11138 if (code == TS_SIGKILL) signame = "KILL";
11139 if (code == TS_SIGPIPE) signame = "PIPE";
11140 if (code == TS_SIGQUIT) signame = "QUIT";
11141 if (code == TS_SIGSEGV) signame = "SEGV";
11142 if (code == TS_SIGTERM) signame = "TERM";
11143 if (code == TS_SIGUSR1) signame = "USR1";
11144 if (code == TS_SIGUSR2) signame = "USR2";
11145 /* The SSH-2 protocol does in principle support arbitrary named
11146 * signals, including signame@domain, but we don't support those. */
11148 /* It's a signal. */
11149 if (ssh->version == 2 && ssh->mainchan) {
11150 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
11151 ssh2_pkt_addstring(pktout, signame);
11152 ssh2_pkt_send(ssh, pktout);
11153 logeventf(ssh, "Sent signal SIG%s", signame);
11156 /* Never heard of it. Do nothing */
11161 void *new_sock_channel(void *handle, struct PortForwarding *pf)
11163 Ssh ssh = (Ssh) handle;
11164 struct ssh_channel *c;
11165 c = snew(struct ssh_channel);
11168 ssh2_channel_init(c);
11169 c->halfopen = TRUE;
11170 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
11172 add234(ssh->channels, c);
11176 unsigned ssh_alloc_sharing_channel(Ssh ssh, void *sharing_ctx)
11178 struct ssh_channel *c;
11179 c = snew(struct ssh_channel);
11182 ssh2_channel_init(c);
11183 c->type = CHAN_SHARING;
11184 c->u.sharing.ctx = sharing_ctx;
11185 add234(ssh->channels, c);
11189 void ssh_delete_sharing_channel(Ssh ssh, unsigned localid)
11191 struct ssh_channel *c;
11193 c = find234(ssh->channels, &localid, ssh_channelfind);
11195 ssh_channel_destroy(c);
11198 void ssh_send_packet_from_downstream(Ssh ssh, unsigned id, int type,
11199 const void *data, int datalen,
11200 const char *additional_log_text)
11202 struct Packet *pkt;
11204 pkt = ssh2_pkt_init(type);
11205 pkt->downstream_id = id;
11206 pkt->additional_log_text = additional_log_text;
11207 ssh2_pkt_adddata(pkt, data, datalen);
11208 ssh2_pkt_send(ssh, pkt);
11212 * This is called when stdout/stderr (the entity to which
11213 * from_backend sends data) manages to clear some backlog.
11215 static void ssh_unthrottle(void *handle, int bufsize)
11217 Ssh ssh = (Ssh) handle;
11220 if (ssh->version == 1) {
11221 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
11222 ssh->v1_stdout_throttling = 0;
11223 ssh_throttle_conn(ssh, -1);
11226 if (ssh->mainchan) {
11227 ssh2_set_window(ssh->mainchan,
11228 bufsize < ssh->mainchan->v.v2.locmaxwin ?
11229 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
11230 if (ssh_is_simple(ssh))
11233 buflimit = ssh->mainchan->v.v2.locmaxwin;
11234 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
11235 ssh->mainchan->throttling_conn = 0;
11236 ssh_throttle_conn(ssh, -1);
11242 * Now process any SSH connection data that was stashed in our
11243 * queue while we were frozen.
11245 ssh_process_queued_incoming_data(ssh);
11248 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
11250 struct ssh_channel *c = (struct ssh_channel *)channel;
11252 struct Packet *pktout;
11254 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
11256 if (ssh->version == 1) {
11257 send_packet(ssh, SSH1_MSG_PORT_OPEN,
11258 PKT_INT, c->localid,
11261 /* PKT_STR, <org:orgport>, */
11264 pktout = ssh2_chanopen_init(c, "direct-tcpip");
11266 char *trimmed_host = host_strduptrim(hostname);
11267 ssh2_pkt_addstring(pktout, trimmed_host);
11268 sfree(trimmed_host);
11270 ssh2_pkt_adduint32(pktout, port);
11272 * We make up values for the originator data; partly it's
11273 * too much hassle to keep track, and partly I'm not
11274 * convinced the server should be told details like that
11275 * about my local network configuration.
11276 * The "originator IP address" is syntactically a numeric
11277 * IP address, and some servers (e.g., Tectia) get upset
11278 * if it doesn't match this syntax.
11280 ssh2_pkt_addstring(pktout, "0.0.0.0");
11281 ssh2_pkt_adduint32(pktout, 0);
11282 ssh2_pkt_send(ssh, pktout);
11286 static int ssh_connected(void *handle)
11288 Ssh ssh = (Ssh) handle;
11289 return ssh->s != NULL;
11292 static int ssh_sendok(void *handle)
11294 Ssh ssh = (Ssh) handle;
11295 return ssh->send_ok;
11298 static int ssh_ldisc(void *handle, int option)
11300 Ssh ssh = (Ssh) handle;
11301 if (option == LD_ECHO)
11302 return ssh->echoing;
11303 if (option == LD_EDIT)
11304 return ssh->editing;
11308 static void ssh_provide_ldisc(void *handle, void *ldisc)
11310 Ssh ssh = (Ssh) handle;
11311 ssh->ldisc = ldisc;
11314 static void ssh_provide_logctx(void *handle, void *logctx)
11316 Ssh ssh = (Ssh) handle;
11317 ssh->logctx = logctx;
11320 static int ssh_return_exitcode(void *handle)
11322 Ssh ssh = (Ssh) handle;
11323 if (ssh->s != NULL)
11326 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
11330 * cfg_info for SSH is the currently running version of the
11331 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
11333 static int ssh_cfg_info(void *handle)
11335 Ssh ssh = (Ssh) handle;
11336 return ssh->version;
11340 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
11341 * that fails. This variable is the means by which scp.c can reach
11342 * into the SSH code and find out which one it got.
11344 extern int ssh_fallback_cmd(void *handle)
11346 Ssh ssh = (Ssh) handle;
11347 return ssh->fallback_cmd;
11350 Backend ssh_backend = {
11360 ssh_return_exitcode,
11364 ssh_provide_logctx,