28 * Packet type contexts, so that ssh2_pkt_type can correctly decode
29 * the ambiguous type numbers back into the correct type strings.
39 SSH2_PKTCTX_PUBLICKEY,
45 static const char *const ssh2_disconnect_reasons[] = {
47 "host not allowed to connect",
49 "key exchange failed",
50 "host authentication failed",
53 "service not available",
54 "protocol version not supported",
55 "host key not verifiable",
58 "too many connections",
59 "auth cancelled by user",
60 "no more auth methods available",
65 * Various remote-bug flags.
67 #define BUG_CHOKES_ON_SSH1_IGNORE 1
68 #define BUG_SSH2_HMAC 2
69 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
70 #define BUG_CHOKES_ON_RSA 8
71 #define BUG_SSH2_RSA_PADDING 16
72 #define BUG_SSH2_DERIVEKEY 32
73 #define BUG_SSH2_REKEY 64
74 #define BUG_SSH2_PK_SESSIONID 128
75 #define BUG_SSH2_MAXPKT 256
76 #define BUG_CHOKES_ON_SSH2_IGNORE 512
77 #define BUG_CHOKES_ON_WINADJ 1024
78 #define BUG_SENDS_LATE_REQUEST_REPLY 2048
79 #define BUG_SSH2_OLDGEX 4096
81 #define DH_MIN_SIZE 1024
82 #define DH_MAX_SIZE 8192
85 * Codes for terminal modes.
86 * Most of these are the same in SSH-1 and SSH-2.
87 * This list is derived from RFC 4254 and
91 const char* const mode;
93 enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
95 /* "V" prefix discarded for special characters relative to SSH specs */
96 { "INTR", 1, TTY_OP_CHAR },
97 { "QUIT", 2, TTY_OP_CHAR },
98 { "ERASE", 3, TTY_OP_CHAR },
99 { "KILL", 4, TTY_OP_CHAR },
100 { "EOF", 5, TTY_OP_CHAR },
101 { "EOL", 6, TTY_OP_CHAR },
102 { "EOL2", 7, TTY_OP_CHAR },
103 { "START", 8, TTY_OP_CHAR },
104 { "STOP", 9, TTY_OP_CHAR },
105 { "SUSP", 10, TTY_OP_CHAR },
106 { "DSUSP", 11, TTY_OP_CHAR },
107 { "REPRINT", 12, TTY_OP_CHAR },
108 { "WERASE", 13, TTY_OP_CHAR },
109 { "LNEXT", 14, TTY_OP_CHAR },
110 { "FLUSH", 15, TTY_OP_CHAR },
111 { "SWTCH", 16, TTY_OP_CHAR },
112 { "STATUS", 17, TTY_OP_CHAR },
113 { "DISCARD", 18, TTY_OP_CHAR },
114 { "IGNPAR", 30, TTY_OP_BOOL },
115 { "PARMRK", 31, TTY_OP_BOOL },
116 { "INPCK", 32, TTY_OP_BOOL },
117 { "ISTRIP", 33, TTY_OP_BOOL },
118 { "INLCR", 34, TTY_OP_BOOL },
119 { "IGNCR", 35, TTY_OP_BOOL },
120 { "ICRNL", 36, TTY_OP_BOOL },
121 { "IUCLC", 37, TTY_OP_BOOL },
122 { "IXON", 38, TTY_OP_BOOL },
123 { "IXANY", 39, TTY_OP_BOOL },
124 { "IXOFF", 40, TTY_OP_BOOL },
125 { "IMAXBEL", 41, TTY_OP_BOOL },
126 { "ISIG", 50, TTY_OP_BOOL },
127 { "ICANON", 51, TTY_OP_BOOL },
128 { "XCASE", 52, TTY_OP_BOOL },
129 { "ECHO", 53, TTY_OP_BOOL },
130 { "ECHOE", 54, TTY_OP_BOOL },
131 { "ECHOK", 55, TTY_OP_BOOL },
132 { "ECHONL", 56, TTY_OP_BOOL },
133 { "NOFLSH", 57, TTY_OP_BOOL },
134 { "TOSTOP", 58, TTY_OP_BOOL },
135 { "IEXTEN", 59, TTY_OP_BOOL },
136 { "ECHOCTL", 60, TTY_OP_BOOL },
137 { "ECHOKE", 61, TTY_OP_BOOL },
138 { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */
139 { "OPOST", 70, TTY_OP_BOOL },
140 { "OLCUC", 71, TTY_OP_BOOL },
141 { "ONLCR", 72, TTY_OP_BOOL },
142 { "OCRNL", 73, TTY_OP_BOOL },
143 { "ONOCR", 74, TTY_OP_BOOL },
144 { "ONLRET", 75, TTY_OP_BOOL },
145 { "CS7", 90, TTY_OP_BOOL },
146 { "CS8", 91, TTY_OP_BOOL },
147 { "PARENB", 92, TTY_OP_BOOL },
148 { "PARODD", 93, TTY_OP_BOOL }
151 /* Miscellaneous other tty-related constants. */
152 #define SSH_TTY_OP_END 0
153 /* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */
154 #define SSH1_TTY_OP_ISPEED 192
155 #define SSH1_TTY_OP_OSPEED 193
156 #define SSH2_TTY_OP_ISPEED 128
157 #define SSH2_TTY_OP_OSPEED 129
159 /* Helper functions for parsing tty-related config. */
160 static unsigned int ssh_tty_parse_specchar(char *s)
165 ret = ctrlparse(s, &next);
166 if (!next) ret = s[0];
168 ret = 255; /* special value meaning "don't set" */
172 static unsigned int ssh_tty_parse_boolean(char *s)
174 if (stricmp(s, "yes") == 0 ||
175 stricmp(s, "on") == 0 ||
176 stricmp(s, "true") == 0 ||
177 stricmp(s, "+") == 0)
179 else if (stricmp(s, "no") == 0 ||
180 stricmp(s, "off") == 0 ||
181 stricmp(s, "false") == 0 ||
182 stricmp(s, "-") == 0)
183 return 0; /* false */
185 return (atoi(s) != 0);
188 #define translate(x) if (type == x) return #x
189 #define translatek(x,ctx) if (type == x && (pkt_kctx == ctx)) return #x
190 #define translatea(x,ctx) if (type == x && (pkt_actx == ctx)) return #x
191 static char *ssh1_pkt_type(int type)
193 translate(SSH1_MSG_DISCONNECT);
194 translate(SSH1_SMSG_PUBLIC_KEY);
195 translate(SSH1_CMSG_SESSION_KEY);
196 translate(SSH1_CMSG_USER);
197 translate(SSH1_CMSG_AUTH_RSA);
198 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
199 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
200 translate(SSH1_CMSG_AUTH_PASSWORD);
201 translate(SSH1_CMSG_REQUEST_PTY);
202 translate(SSH1_CMSG_WINDOW_SIZE);
203 translate(SSH1_CMSG_EXEC_SHELL);
204 translate(SSH1_CMSG_EXEC_CMD);
205 translate(SSH1_SMSG_SUCCESS);
206 translate(SSH1_SMSG_FAILURE);
207 translate(SSH1_CMSG_STDIN_DATA);
208 translate(SSH1_SMSG_STDOUT_DATA);
209 translate(SSH1_SMSG_STDERR_DATA);
210 translate(SSH1_CMSG_EOF);
211 translate(SSH1_SMSG_EXIT_STATUS);
212 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
213 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
214 translate(SSH1_MSG_CHANNEL_DATA);
215 translate(SSH1_MSG_CHANNEL_CLOSE);
216 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
217 translate(SSH1_SMSG_X11_OPEN);
218 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
219 translate(SSH1_MSG_PORT_OPEN);
220 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
221 translate(SSH1_SMSG_AGENT_OPEN);
222 translate(SSH1_MSG_IGNORE);
223 translate(SSH1_CMSG_EXIT_CONFIRMATION);
224 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
225 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
226 translate(SSH1_MSG_DEBUG);
227 translate(SSH1_CMSG_REQUEST_COMPRESSION);
228 translate(SSH1_CMSG_AUTH_TIS);
229 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
230 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
231 translate(SSH1_CMSG_AUTH_CCARD);
232 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
233 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
236 static char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx, int type)
238 translatea(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,SSH2_PKTCTX_GSSAPI);
239 translatea(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,SSH2_PKTCTX_GSSAPI);
240 translatea(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,SSH2_PKTCTX_GSSAPI);
241 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERROR,SSH2_PKTCTX_GSSAPI);
242 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK,SSH2_PKTCTX_GSSAPI);
243 translatea(SSH2_MSG_USERAUTH_GSSAPI_MIC, SSH2_PKTCTX_GSSAPI);
244 translate(SSH2_MSG_DISCONNECT);
245 translate(SSH2_MSG_IGNORE);
246 translate(SSH2_MSG_UNIMPLEMENTED);
247 translate(SSH2_MSG_DEBUG);
248 translate(SSH2_MSG_SERVICE_REQUEST);
249 translate(SSH2_MSG_SERVICE_ACCEPT);
250 translate(SSH2_MSG_KEXINIT);
251 translate(SSH2_MSG_NEWKEYS);
252 translatek(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
253 translatek(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
254 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST_OLD, SSH2_PKTCTX_DHGEX);
255 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
256 translatek(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
257 translatek(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
258 translatek(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
259 translatek(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX);
260 translatek(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX);
261 translatek(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX);
262 translate(SSH2_MSG_USERAUTH_REQUEST);
263 translate(SSH2_MSG_USERAUTH_FAILURE);
264 translate(SSH2_MSG_USERAUTH_SUCCESS);
265 translate(SSH2_MSG_USERAUTH_BANNER);
266 translatea(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
267 translatea(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
268 translatea(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
269 translatea(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
270 translate(SSH2_MSG_GLOBAL_REQUEST);
271 translate(SSH2_MSG_REQUEST_SUCCESS);
272 translate(SSH2_MSG_REQUEST_FAILURE);
273 translate(SSH2_MSG_CHANNEL_OPEN);
274 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
275 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
276 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
277 translate(SSH2_MSG_CHANNEL_DATA);
278 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
279 translate(SSH2_MSG_CHANNEL_EOF);
280 translate(SSH2_MSG_CHANNEL_CLOSE);
281 translate(SSH2_MSG_CHANNEL_REQUEST);
282 translate(SSH2_MSG_CHANNEL_SUCCESS);
283 translate(SSH2_MSG_CHANNEL_FAILURE);
289 /* Enumeration values for fields in SSH-1 packets */
291 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
295 * Coroutine mechanics for the sillier bits of the code. If these
296 * macros look impenetrable to you, you might find it helpful to
299 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
301 * which explains the theory behind these macros.
303 * In particular, if you are getting `case expression not constant'
304 * errors when building with MS Visual Studio, this is because MS's
305 * Edit and Continue debugging feature causes their compiler to
306 * violate ANSI C. To disable Edit and Continue debugging:
308 * - right-click ssh.c in the FileView
310 * - select the C/C++ tab and the General category
311 * - under `Debug info:', select anything _other_ than `Program
312 * Database for Edit and Continue'.
314 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
315 #define crBeginState crBegin(s->crLine)
316 #define crStateP(t, v) \
318 if (!(v)) { s = (v) = snew(struct t); s->crLine = 0; } \
320 #define crState(t) crStateP(t, ssh->t)
321 #define crFinish(z) } *crLine = 0; return (z); }
322 #define crFinishV } *crLine = 0; return; }
323 #define crFinishFree(z) } sfree(s); return (z); }
324 #define crFinishFreeV } sfree(s); return; }
325 #define crReturn(z) \
327 *crLine =__LINE__; return (z); case __LINE__:;\
331 *crLine=__LINE__; return; case __LINE__:;\
333 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
334 #define crStopV do{ *crLine = 0; return; }while(0)
335 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
336 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
340 static struct Packet *ssh1_pkt_init(int pkt_type);
341 static struct Packet *ssh2_pkt_init(int pkt_type);
342 static void ssh_pkt_ensure(struct Packet *, int length);
343 static void ssh_pkt_adddata(struct Packet *, const void *data, int len);
344 static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
345 static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
346 static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
347 static void ssh_pkt_addstring_start(struct Packet *);
348 static void ssh_pkt_addstring_str(struct Packet *, const char *data);
349 static void ssh_pkt_addstring_data(struct Packet *, const char *data, int len);
350 static void ssh_pkt_addstring(struct Packet *, const char *data);
351 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
352 static void ssh1_pkt_addmp(struct Packet *, Bignum b);
353 static void ssh2_pkt_addmp(struct Packet *, Bignum b);
354 static int ssh2_pkt_construct(Ssh, struct Packet *);
355 static void ssh2_pkt_send(Ssh, struct Packet *);
356 static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
357 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
358 struct Packet *pktin);
359 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
360 struct Packet *pktin);
361 static void ssh2_channel_check_close(struct ssh_channel *c);
362 static void ssh_channel_destroy(struct ssh_channel *c);
363 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin);
366 * Buffer management constants. There are several of these for
367 * various different purposes:
369 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
370 * on a local data stream before we throttle the whole SSH
371 * connection (in SSH-1 only). Throttling the whole connection is
372 * pretty drastic so we set this high in the hope it won't
375 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
376 * on the SSH connection itself before we defensively throttle
377 * _all_ local data streams. This is pretty drastic too (though
378 * thankfully unlikely in SSH-2 since the window mechanism should
379 * ensure that the server never has any need to throttle its end
380 * of the connection), so we set this high as well.
382 * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
385 * - OUR_V2_BIGWIN is the window size we advertise for the only
386 * channel in a simple connection. It must be <= INT_MAX.
388 * - OUR_V2_MAXPKT is the official "maximum packet size" we send
389 * to the remote side. This actually has nothing to do with the
390 * size of the _packet_, but is instead a limit on the amount
391 * of data we're willing to receive in a single SSH2 channel
394 * - OUR_V2_PACKETLIMIT is actually the maximum size of SSH
395 * _packet_ we're prepared to cope with. It must be a multiple
396 * of the cipher block size, and must be at least 35000.
399 #define SSH1_BUFFER_LIMIT 32768
400 #define SSH_MAX_BACKLOG 32768
401 #define OUR_V2_WINSIZE 16384
402 #define OUR_V2_BIGWIN 0x7fffffff
403 #define OUR_V2_MAXPKT 0x4000UL
404 #define OUR_V2_PACKETLIMIT 0x9000UL
406 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
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 * RFC 4253 doesn't explicitly say that completely empty packets
1748 * with no type byte are forbidden, so treat them as deserving
1749 * an SSH_MSG_UNIMPLEMENTED.
1751 if (st->pktin->length <= 5) { /* == 5 we hope, but robustness */
1752 ssh2_msg_something_unimplemented(ssh, st->pktin);
1756 * pktin->body and pktin->length should identify the semantic
1757 * content of the packet, excluding the initial type byte.
1759 st->pktin->type = st->pktin->data[5];
1760 st->pktin->body = st->pktin->data + 6;
1761 st->pktin->length -= 6;
1762 assert(st->pktin->length >= 0); /* one last double-check */
1765 ssh2_log_incoming_packet(ssh, st->pktin);
1767 st->pktin->savedpos = 0;
1769 crFinish(st->pktin);
1772 static struct Packet *ssh2_bare_connection_rdpkt(Ssh ssh, unsigned char **data,
1775 struct rdpkt2_bare_state_tag *st = &ssh->rdpkt2_bare_state;
1777 crBegin(ssh->ssh2_bare_rdpkt_crstate);
1780 * Read the packet length field.
1782 for (st->i = 0; st->i < 4; st->i++) {
1783 while ((*datalen) == 0)
1785 st->length[st->i] = *(*data)++;
1789 st->packetlen = toint(GET_32BIT_MSB_FIRST(st->length));
1790 if (st->packetlen <= 0 || st->packetlen >= OUR_V2_PACKETLIMIT) {
1791 bombout(("Invalid packet length received"));
1795 st->pktin = ssh_new_packet();
1796 st->pktin->data = snewn(st->packetlen, unsigned char);
1798 st->pktin->encrypted_len = st->packetlen;
1800 st->pktin->sequence = st->incoming_sequence++;
1803 * Read the remainder of the packet.
1805 for (st->i = 0; st->i < st->packetlen; st->i++) {
1806 while ((*datalen) == 0)
1808 st->pktin->data[st->i] = *(*data)++;
1813 * pktin->body and pktin->length should identify the semantic
1814 * content of the packet, excluding the initial type byte.
1816 st->pktin->type = st->pktin->data[0];
1817 st->pktin->body = st->pktin->data + 1;
1818 st->pktin->length = st->packetlen - 1;
1821 * Log incoming packet, possibly omitting sensitive fields.
1824 ssh2_log_incoming_packet(ssh, st->pktin);
1826 st->pktin->savedpos = 0;
1828 crFinish(st->pktin);
1831 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1833 int pad, biglen, i, pktoffs;
1837 * XXX various versions of SC (including 8.8.4) screw up the
1838 * register allocation in this function and use the same register
1839 * (D6) for len and as a temporary, with predictable results. The
1840 * following sledgehammer prevents this.
1847 ssh1_log_outgoing_packet(ssh, pkt);
1849 if (ssh->v1_compressing) {
1850 unsigned char *compblk;
1852 zlib_compress_block(ssh->cs_comp_ctx,
1853 pkt->data + 12, pkt->length - 12,
1854 &compblk, &complen);
1855 ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */
1856 memcpy(pkt->data + 12, compblk, complen);
1858 pkt->length = complen + 12;
1861 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1863 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
1864 pad = 8 - (len % 8);
1866 biglen = len + pad; /* len(padding+type+data+CRC) */
1868 for (i = pktoffs; i < 4+8; i++)
1869 pkt->data[i] = random_byte();
1870 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1871 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1872 PUT_32BIT(pkt->data + pktoffs, len);
1875 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1876 pkt->data + pktoffs + 4, biglen);
1878 if (offset_p) *offset_p = pktoffs;
1879 return biglen + 4; /* len(length+padding+type+data+CRC) */
1882 static int s_write(Ssh ssh, void *data, int len)
1885 log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len,
1886 0, NULL, NULL, 0, NULL);
1889 return sk_write(ssh->s, (char *)data, len);
1892 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1894 int len, backlog, offset;
1895 len = s_wrpkt_prepare(ssh, pkt, &offset);
1896 backlog = s_write(ssh, pkt->data + offset, len);
1897 if (backlog > SSH_MAX_BACKLOG)
1898 ssh_throttle_all(ssh, 1, backlog);
1899 ssh_free_packet(pkt);
1902 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1905 len = s_wrpkt_prepare(ssh, pkt, &offset);
1906 if (ssh->deferred_len + len > ssh->deferred_size) {
1907 ssh->deferred_size = ssh->deferred_len + len + 128;
1908 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1912 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1913 pkt->data + offset, len);
1914 ssh->deferred_len += len;
1915 ssh_free_packet(pkt);
1919 * Construct a SSH-1 packet with the specified contents.
1920 * (This all-at-once interface used to be the only one, but now SSH-1
1921 * packets can also be constructed incrementally.)
1923 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
1929 pkt = ssh1_pkt_init(pkttype);
1931 while ((argtype = va_arg(ap, int)) != PKT_END) {
1932 unsigned char *argp, argchar;
1934 unsigned long argint;
1937 /* Actual fields in the packet */
1939 argint = va_arg(ap, int);
1940 ssh_pkt_adduint32(pkt, argint);
1943 argchar = (unsigned char) va_arg(ap, int);
1944 ssh_pkt_addbyte(pkt, argchar);
1947 argp = va_arg(ap, unsigned char *);
1948 arglen = va_arg(ap, int);
1949 ssh_pkt_adddata(pkt, argp, arglen);
1952 sargp = va_arg(ap, char *);
1953 ssh_pkt_addstring(pkt, sargp);
1956 bn = va_arg(ap, Bignum);
1957 ssh1_pkt_addmp(pkt, bn);
1965 static void send_packet(Ssh ssh, int pkttype, ...)
1969 va_start(ap, pkttype);
1970 pkt = construct_packet(ssh, pkttype, ap);
1975 static void defer_packet(Ssh ssh, int pkttype, ...)
1979 va_start(ap, pkttype);
1980 pkt = construct_packet(ssh, pkttype, ap);
1982 s_wrpkt_defer(ssh, pkt);
1985 static int ssh_versioncmp(char *a, char *b)
1988 unsigned long av, bv;
1990 av = strtoul(a, &ae, 10);
1991 bv = strtoul(b, &be, 10);
1993 return (av < bv ? -1 : +1);
1998 av = strtoul(ae, &ae, 10);
1999 bv = strtoul(be, &be, 10);
2001 return (av < bv ? -1 : +1);
2006 * Utility routines for putting an SSH-protocol `string' and
2007 * `uint32' into a hash state.
2009 static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
2011 unsigned char lenblk[4];
2012 PUT_32BIT(lenblk, len);
2013 h->bytes(s, lenblk, 4);
2014 h->bytes(s, str, len);
2017 static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
2019 unsigned char intblk[4];
2020 PUT_32BIT(intblk, i);
2021 h->bytes(s, intblk, 4);
2025 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
2027 static void ssh_pkt_ensure(struct Packet *pkt, int length)
2029 if (pkt->maxlen < length) {
2030 unsigned char *body = pkt->body;
2031 int offset = body ? body - pkt->data : 0;
2032 pkt->maxlen = length + 256;
2033 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
2034 if (body) pkt->body = pkt->data + offset;
2037 static void ssh_pkt_adddata(struct Packet *pkt, const void *data, int len)
2040 ssh_pkt_ensure(pkt, pkt->length);
2041 memcpy(pkt->data + pkt->length - len, data, len);
2043 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
2045 ssh_pkt_adddata(pkt, &byte, 1);
2047 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
2049 ssh_pkt_adddata(pkt, &value, 1);
2051 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
2054 PUT_32BIT(x, value);
2055 ssh_pkt_adddata(pkt, x, 4);
2057 static void ssh_pkt_addstring_start(struct Packet *pkt)
2059 ssh_pkt_adduint32(pkt, 0);
2060 pkt->savedpos = pkt->length;
2062 static void ssh_pkt_addstring_str(struct Packet *pkt, const char *data)
2064 ssh_pkt_adddata(pkt, data, strlen(data));
2065 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
2067 static void ssh_pkt_addstring_data(struct Packet *pkt, const char *data,
2070 ssh_pkt_adddata(pkt, data, len);
2071 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
2073 static void ssh_pkt_addstring(struct Packet *pkt, const char *data)
2075 ssh_pkt_addstring_start(pkt);
2076 ssh_pkt_addstring_str(pkt, data);
2078 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
2080 int len = ssh1_bignum_length(b);
2081 unsigned char *data = snewn(len, unsigned char);
2082 (void) ssh1_write_bignum(data, b);
2083 ssh_pkt_adddata(pkt, data, len);
2086 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
2089 int i, n = (bignum_bitcount(b) + 7) / 8;
2090 p = snewn(n + 1, unsigned char);
2092 for (i = 1; i <= n; i++)
2093 p[i] = bignum_byte(b, n - i);
2095 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
2097 memmove(p, p + i, n + 1 - i);
2101 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
2105 p = ssh2_mpint_fmt(b, &len);
2106 ssh_pkt_addstring_start(pkt);
2107 ssh_pkt_addstring_data(pkt, (char *)p, len);
2111 static struct Packet *ssh1_pkt_init(int pkt_type)
2113 struct Packet *pkt = ssh_new_packet();
2114 pkt->length = 4 + 8; /* space for length + max padding */
2115 ssh_pkt_addbyte(pkt, pkt_type);
2116 pkt->body = pkt->data + pkt->length;
2117 pkt->type = pkt_type;
2118 pkt->downstream_id = 0;
2119 pkt->additional_log_text = NULL;
2123 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
2124 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
2125 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
2126 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
2127 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
2128 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
2129 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
2130 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
2131 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
2133 static struct Packet *ssh2_pkt_init(int pkt_type)
2135 struct Packet *pkt = ssh_new_packet();
2136 pkt->length = 5; /* space for packet length + padding length */
2138 pkt->type = pkt_type;
2139 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
2140 pkt->body = pkt->data + pkt->length; /* after packet type */
2141 pkt->downstream_id = 0;
2142 pkt->additional_log_text = NULL;
2147 * Construct an SSH-2 final-form packet: compress it, encrypt it,
2148 * put the MAC on it. Final packet, ready to be sent, is stored in
2149 * pkt->data. Total length is returned.
2151 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
2153 int cipherblk, maclen, padding, i;
2156 ssh2_log_outgoing_packet(ssh, pkt);
2158 if (ssh->bare_connection) {
2160 * Trivial packet construction for the bare connection
2163 PUT_32BIT(pkt->data + 1, pkt->length - 5);
2164 pkt->body = pkt->data + 1;
2165 ssh->v2_outgoing_sequence++; /* only for diagnostics, really */
2166 return pkt->length - 1;
2170 * Compress packet payload.
2173 unsigned char *newpayload;
2176 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
2178 &newpayload, &newlen)) {
2180 ssh2_pkt_adddata(pkt, newpayload, newlen);
2186 * Add padding. At least four bytes, and must also bring total
2187 * length (minus MAC) up to a multiple of the block size.
2188 * If pkt->forcepad is set, make sure the packet is at least that size
2191 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
2192 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
2194 if (pkt->length + padding < pkt->forcepad)
2195 padding = pkt->forcepad - pkt->length;
2197 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
2198 assert(padding <= 255);
2199 maclen = ssh->csmac ? ssh->csmac->len : 0;
2200 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
2201 pkt->data[4] = padding;
2202 for (i = 0; i < padding; i++)
2203 pkt->data[pkt->length + i] = random_byte();
2204 PUT_32BIT(pkt->data, pkt->length + padding - 4);
2206 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
2207 pkt->length + padding,
2208 ssh->v2_outgoing_sequence);
2209 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
2212 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
2213 pkt->data, pkt->length + padding);
2215 pkt->encrypted_len = pkt->length + padding;
2217 /* Ready-to-send packet starts at pkt->data. We return length. */
2218 pkt->body = pkt->data;
2219 return pkt->length + padding + maclen;
2223 * Routines called from the main SSH code to send packets. There
2224 * are quite a few of these, because we have two separate
2225 * mechanisms for delaying the sending of packets:
2227 * - In order to send an IGNORE message and a password message in
2228 * a single fixed-length blob, we require the ability to
2229 * concatenate the encrypted forms of those two packets _into_ a
2230 * single blob and then pass it to our <network.h> transport
2231 * layer in one go. Hence, there's a deferment mechanism which
2232 * works after packet encryption.
2234 * - In order to avoid sending any connection-layer messages
2235 * during repeat key exchange, we have to queue up any such
2236 * outgoing messages _before_ they are encrypted (and in
2237 * particular before they're allocated sequence numbers), and
2238 * then send them once we've finished.
2240 * I call these mechanisms `defer' and `queue' respectively, so as
2241 * to distinguish them reasonably easily.
2243 * The functions send_noqueue() and defer_noqueue() free the packet
2244 * structure they are passed. Every outgoing packet goes through
2245 * precisely one of these functions in its life; packets passed to
2246 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
2247 * these or get queued, and then when the queue is later emptied
2248 * the packets are all passed to defer_noqueue().
2250 * When using a CBC-mode cipher, it's necessary to ensure that an
2251 * attacker can't provide data to be encrypted using an IV that they
2252 * know. We ensure this by prefixing each packet that might contain
2253 * user data with an SSH_MSG_IGNORE. This is done using the deferral
2254 * mechanism, so in this case send_noqueue() ends up redirecting to
2255 * defer_noqueue(). If you don't like this inefficiency, don't use
2259 static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
2260 static void ssh_pkt_defersend(Ssh);
2263 * Send an SSH-2 packet immediately, without queuing or deferring.
2265 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
2269 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
2270 /* We need to send two packets, so use the deferral mechanism. */
2271 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2272 ssh_pkt_defersend(ssh);
2275 len = ssh2_pkt_construct(ssh, pkt);
2276 backlog = s_write(ssh, pkt->body, len);
2277 if (backlog > SSH_MAX_BACKLOG)
2278 ssh_throttle_all(ssh, 1, backlog);
2280 ssh->outgoing_data_size += pkt->encrypted_len;
2281 if (!ssh->kex_in_progress &&
2282 !ssh->bare_connection &&
2283 ssh->max_data_size != 0 &&
2284 ssh->outgoing_data_size > ssh->max_data_size)
2285 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2287 ssh_free_packet(pkt);
2291 * Defer an SSH-2 packet.
2293 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
2296 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
2297 ssh->deferred_len == 0 && !noignore &&
2298 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2300 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2301 * get encrypted with a known IV.
2303 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2304 ssh2_pkt_addstring_start(ipkt);
2305 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
2307 len = ssh2_pkt_construct(ssh, pkt);
2308 if (ssh->deferred_len + len > ssh->deferred_size) {
2309 ssh->deferred_size = ssh->deferred_len + len + 128;
2310 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2314 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->body, len);
2315 ssh->deferred_len += len;
2316 ssh->deferred_data_size += pkt->encrypted_len;
2317 ssh_free_packet(pkt);
2321 * Queue an SSH-2 packet.
2323 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
2325 assert(ssh->queueing);
2327 if (ssh->queuelen >= ssh->queuesize) {
2328 ssh->queuesize = ssh->queuelen + 32;
2329 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
2332 ssh->queue[ssh->queuelen++] = pkt;
2336 * Either queue or send a packet, depending on whether queueing is
2339 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
2342 ssh2_pkt_queue(ssh, pkt);
2344 ssh2_pkt_send_noqueue(ssh, pkt);
2348 * Either queue or defer a packet, depending on whether queueing is
2351 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
2354 ssh2_pkt_queue(ssh, pkt);
2356 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2360 * Send the whole deferred data block constructed by
2361 * ssh2_pkt_defer() or SSH-1's defer_packet().
2363 * The expected use of the defer mechanism is that you call
2364 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2365 * not currently queueing, this simply sets up deferred_send_data
2366 * and then sends it. If we _are_ currently queueing, the calls to
2367 * ssh2_pkt_defer() put the deferred packets on to the queue
2368 * instead, and therefore ssh_pkt_defersend() has no deferred data
2369 * to send. Hence, there's no need to make it conditional on
2372 static void ssh_pkt_defersend(Ssh ssh)
2375 backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
2376 ssh->deferred_len = ssh->deferred_size = 0;
2377 sfree(ssh->deferred_send_data);
2378 ssh->deferred_send_data = NULL;
2379 if (backlog > SSH_MAX_BACKLOG)
2380 ssh_throttle_all(ssh, 1, backlog);
2382 ssh->outgoing_data_size += ssh->deferred_data_size;
2383 if (!ssh->kex_in_progress &&
2384 !ssh->bare_connection &&
2385 ssh->max_data_size != 0 &&
2386 ssh->outgoing_data_size > ssh->max_data_size)
2387 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2388 ssh->deferred_data_size = 0;
2392 * Send a packet whose length needs to be disguised (typically
2393 * passwords or keyboard-interactive responses).
2395 static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
2401 * The simplest way to do this is to adjust the
2402 * variable-length padding field in the outgoing packet.
2404 * Currently compiled out, because some Cisco SSH servers
2405 * don't like excessively padded packets (bah, why's it
2408 pkt->forcepad = padsize;
2409 ssh2_pkt_send(ssh, pkt);
2414 * If we can't do that, however, an alternative approach is
2415 * to use the pkt_defer mechanism to bundle the packet
2416 * tightly together with an SSH_MSG_IGNORE such that their
2417 * combined length is a constant. So first we construct the
2418 * final form of this packet and defer its sending.
2420 ssh2_pkt_defer(ssh, pkt);
2423 * Now construct an SSH_MSG_IGNORE which includes a string
2424 * that's an exact multiple of the cipher block size. (If
2425 * the cipher is NULL so that the block size is
2426 * unavailable, we don't do this trick at all, because we
2427 * gain nothing by it.)
2429 if (ssh->cscipher &&
2430 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2433 stringlen = (256 - ssh->deferred_len);
2434 stringlen += ssh->cscipher->blksize - 1;
2435 stringlen -= (stringlen % ssh->cscipher->blksize);
2438 * Temporarily disable actual compression, so we
2439 * can guarantee to get this string exactly the
2440 * length we want it. The compression-disabling
2441 * routine should return an integer indicating how
2442 * many bytes we should adjust our string length
2446 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
2448 pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2449 ssh2_pkt_addstring_start(pkt);
2450 for (i = 0; i < stringlen; i++) {
2451 char c = (char) random_byte();
2452 ssh2_pkt_addstring_data(pkt, &c, 1);
2454 ssh2_pkt_defer(ssh, pkt);
2456 ssh_pkt_defersend(ssh);
2461 * Send all queued SSH-2 packets. We send them by means of
2462 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2463 * packets that needed to be lumped together.
2465 static void ssh2_pkt_queuesend(Ssh ssh)
2469 assert(!ssh->queueing);
2471 for (i = 0; i < ssh->queuelen; i++)
2472 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
2475 ssh_pkt_defersend(ssh);
2479 void bndebug(char *string, Bignum b)
2483 p = ssh2_mpint_fmt(b, &len);
2484 debug(("%s", string));
2485 for (i = 0; i < len; i++)
2486 debug((" %02x", p[i]));
2492 static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
2496 p = ssh2_mpint_fmt(b, &len);
2497 hash_string(h, s, p, len);
2502 * Packet decode functions for both SSH-1 and SSH-2.
2504 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
2506 unsigned long value;
2507 if (pkt->length - pkt->savedpos < 4)
2508 return 0; /* arrgh, no way to decline (FIXME?) */
2509 value = GET_32BIT(pkt->body + pkt->savedpos);
2513 static int ssh2_pkt_getbool(struct Packet *pkt)
2515 unsigned long value;
2516 if (pkt->length - pkt->savedpos < 1)
2517 return 0; /* arrgh, no way to decline (FIXME?) */
2518 value = pkt->body[pkt->savedpos] != 0;
2522 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
2527 if (pkt->length - pkt->savedpos < 4)
2529 len = toint(GET_32BIT(pkt->body + pkt->savedpos));
2534 if (pkt->length - pkt->savedpos < *length)
2536 *p = (char *)(pkt->body + pkt->savedpos);
2537 pkt->savedpos += *length;
2539 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
2541 if (pkt->length - pkt->savedpos < length)
2543 pkt->savedpos += length;
2544 return pkt->body + (pkt->savedpos - length);
2546 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2547 unsigned char **keystr)
2551 j = makekey(pkt->body + pkt->savedpos,
2552 pkt->length - pkt->savedpos,
2559 assert(pkt->savedpos < pkt->length);
2563 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2568 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2569 pkt->length - pkt->savedpos, &b);
2577 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2583 ssh_pkt_getstring(pkt, &p, &length);
2588 b = bignum_from_bytes((unsigned char *)p, length);
2593 * Helper function to add an SSH-2 signature blob to a packet.
2594 * Expects to be shown the public key blob as well as the signature
2595 * blob. Normally works just like ssh2_pkt_addstring, but will
2596 * fiddle with the signature packet if necessary for
2597 * BUG_SSH2_RSA_PADDING.
2599 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2600 void *pkblob_v, int pkblob_len,
2601 void *sigblob_v, int sigblob_len)
2603 unsigned char *pkblob = (unsigned char *)pkblob_v;
2604 unsigned char *sigblob = (unsigned char *)sigblob_v;
2606 /* dmemdump(pkblob, pkblob_len); */
2607 /* dmemdump(sigblob, sigblob_len); */
2610 * See if this is in fact an ssh-rsa signature and a buggy
2611 * server; otherwise we can just do this the easy way.
2613 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) && pkblob_len > 4+7+4 &&
2614 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2615 int pos, len, siglen;
2618 * Find the byte length of the modulus.
2621 pos = 4+7; /* skip over "ssh-rsa" */
2622 len = toint(GET_32BIT(pkblob+pos)); /* get length of exponent */
2623 if (len < 0 || len > pkblob_len - pos - 4)
2625 pos += 4 + len; /* skip over exponent */
2626 if (pkblob_len - pos < 4)
2628 len = toint(GET_32BIT(pkblob+pos)); /* find length of modulus */
2629 if (len < 0 || len > pkblob_len - pos - 4)
2631 pos += 4; /* find modulus itself */
2632 while (len > 0 && pkblob[pos] == 0)
2634 /* debug(("modulus length is %d\n", len)); */
2637 * Now find the signature integer.
2639 pos = 4+7; /* skip over "ssh-rsa" */
2640 if (sigblob_len < pos+4)
2642 siglen = toint(GET_32BIT(sigblob+pos));
2643 if (siglen != sigblob_len - pos - 4)
2645 /* debug(("signature length is %d\n", siglen)); */
2647 if (len != siglen) {
2648 unsigned char newlen[4];
2649 ssh2_pkt_addstring_start(pkt);
2650 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2651 /* dmemdump(sigblob, pos); */
2652 pos += 4; /* point to start of actual sig */
2653 PUT_32BIT(newlen, len);
2654 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2655 /* dmemdump(newlen, 4); */
2657 while (len-- > siglen) {
2658 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2659 /* dmemdump(newlen, 1); */
2661 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2662 /* dmemdump(sigblob+pos, siglen); */
2666 /* Otherwise fall through and do it the easy way. We also come
2667 * here as a fallback if we discover above that the key blob
2668 * is misformatted in some way. */
2672 ssh2_pkt_addstring_start(pkt);
2673 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2677 * Examine the remote side's version string and compare it against
2678 * a list of known buggy implementations.
2680 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2682 char *imp; /* pointer to implementation part */
2684 imp += strcspn(imp, "-");
2686 imp += strcspn(imp, "-");
2689 ssh->remote_bugs = 0;
2692 * General notes on server version strings:
2693 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2694 * here -- in particular, we've heard of one that's perfectly happy
2695 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2696 * so we can't distinguish them.
2698 if (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == FORCE_ON ||
2699 (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == AUTO &&
2700 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2701 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2702 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2703 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2705 * These versions don't support SSH1_MSG_IGNORE, so we have
2706 * to use a different defence against password length
2709 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2710 logevent("We believe remote version has SSH-1 ignore bug");
2713 if (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == FORCE_ON ||
2714 (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == AUTO &&
2715 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2717 * These versions need a plain password sent; they can't
2718 * handle having a null and a random length of data after
2721 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2722 logevent("We believe remote version needs a plain SSH-1 password");
2725 if (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == FORCE_ON ||
2726 (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == AUTO &&
2727 (!strcmp(imp, "Cisco-1.25")))) {
2729 * These versions apparently have no clue whatever about
2730 * RSA authentication and will panic and die if they see
2731 * an AUTH_RSA message.
2733 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2734 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2737 if (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == FORCE_ON ||
2738 (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == AUTO &&
2739 !wc_match("* VShell", imp) &&
2740 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2741 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2742 wc_match("2.1 *", imp)))) {
2744 * These versions have the HMAC bug.
2746 ssh->remote_bugs |= BUG_SSH2_HMAC;
2747 logevent("We believe remote version has SSH-2 HMAC bug");
2750 if (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == FORCE_ON ||
2751 (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == AUTO &&
2752 !wc_match("* VShell", imp) &&
2753 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2755 * These versions have the key-derivation bug (failing to
2756 * include the literal shared secret in the hashes that
2757 * generate the keys).
2759 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2760 logevent("We believe remote version has SSH-2 key-derivation bug");
2763 if (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == FORCE_ON ||
2764 (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == AUTO &&
2765 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2766 wc_match("OpenSSH_3.[0-2]*", imp) ||
2767 wc_match("mod_sftp/0.[0-8]*", imp) ||
2768 wc_match("mod_sftp/0.9.[0-8]", imp)))) {
2770 * These versions have the SSH-2 RSA padding bug.
2772 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2773 logevent("We believe remote version has SSH-2 RSA padding bug");
2776 if (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == FORCE_ON ||
2777 (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == AUTO &&
2778 wc_match("OpenSSH_2.[0-2]*", imp))) {
2780 * These versions have the SSH-2 session-ID bug in
2781 * public-key authentication.
2783 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2784 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2787 if (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == FORCE_ON ||
2788 (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == AUTO &&
2789 (wc_match("DigiSSH_2.0", imp) ||
2790 wc_match("OpenSSH_2.[0-4]*", imp) ||
2791 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2792 wc_match("Sun_SSH_1.0", imp) ||
2793 wc_match("Sun_SSH_1.0.1", imp) ||
2794 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2795 wc_match("WeOnlyDo-*", imp)))) {
2797 * These versions have the SSH-2 rekey bug.
2799 ssh->remote_bugs |= BUG_SSH2_REKEY;
2800 logevent("We believe remote version has SSH-2 rekey bug");
2803 if (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == FORCE_ON ||
2804 (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == AUTO &&
2805 (wc_match("1.36_sshlib GlobalSCAPE", imp) ||
2806 wc_match("1.36 sshlib: GlobalScape", imp)))) {
2808 * This version ignores our makpkt and needs to be throttled.
2810 ssh->remote_bugs |= BUG_SSH2_MAXPKT;
2811 logevent("We believe remote version ignores SSH-2 maximum packet size");
2814 if (conf_get_int(ssh->conf, CONF_sshbug_ignore2) == FORCE_ON) {
2816 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2817 * none detected automatically.
2819 ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE;
2820 logevent("We believe remote version has SSH-2 ignore bug");
2823 if (conf_get_int(ssh->conf, CONF_sshbug_oldgex2) == FORCE_ON ||
2824 (conf_get_int(ssh->conf, CONF_sshbug_oldgex2) == AUTO &&
2825 (wc_match("OpenSSH_2.[235]*", imp)))) {
2827 * These versions only support the original (pre-RFC4419)
2828 * SSH-2 GEX request.
2830 ssh->remote_bugs |= BUG_SSH2_OLDGEX;
2831 logevent("We believe remote version has outdated SSH-2 GEX");
2834 if (conf_get_int(ssh->conf, CONF_sshbug_winadj) == FORCE_ON) {
2836 * Servers that don't support our winadj request for one
2837 * reason or another. Currently, none detected automatically.
2839 ssh->remote_bugs |= BUG_CHOKES_ON_WINADJ;
2840 logevent("We believe remote version has winadj bug");
2843 if (conf_get_int(ssh->conf, CONF_sshbug_chanreq) == FORCE_ON ||
2844 (conf_get_int(ssh->conf, CONF_sshbug_chanreq) == AUTO &&
2845 (wc_match("OpenSSH_[2-5].*", imp) ||
2846 wc_match("OpenSSH_6.[0-6]*", imp) ||
2847 wc_match("dropbear_0.[2-4][0-9]*", imp) ||
2848 wc_match("dropbear_0.5[01]*", imp)))) {
2850 * These versions have the SSH-2 channel request bug.
2851 * OpenSSH 6.7 and above do not:
2852 * https://bugzilla.mindrot.org/show_bug.cgi?id=1818
2853 * dropbear_0.52 and above do not:
2854 * https://secure.ucc.asn.au/hg/dropbear/rev/cd02449b709c
2856 ssh->remote_bugs |= BUG_SENDS_LATE_REQUEST_REPLY;
2857 logevent("We believe remote version has SSH-2 channel request bug");
2862 * The `software version' part of an SSH version string is required
2863 * to contain no spaces or minus signs.
2865 static void ssh_fix_verstring(char *str)
2867 /* Eat "<protoversion>-". */
2868 while (*str && *str != '-') str++;
2869 assert(*str == '-'); str++;
2871 /* Convert minus signs and spaces in the remaining string into
2874 if (*str == '-' || *str == ' ')
2881 * Send an appropriate SSH version string.
2883 static void ssh_send_verstring(Ssh ssh, const char *protoname, char *svers)
2887 if (ssh->version == 2) {
2889 * Construct a v2 version string.
2891 verstring = dupprintf("%s2.0-%s\015\012", protoname, sshver);
2894 * Construct a v1 version string.
2896 assert(!strcmp(protoname, "SSH-")); /* no v1 bare connection protocol */
2897 verstring = dupprintf("SSH-%s-%s\012",
2898 (ssh_versioncmp(svers, "1.5") <= 0 ?
2903 ssh_fix_verstring(verstring + strlen(protoname));
2905 if (ssh->version == 2) {
2908 * Record our version string.
2910 len = strcspn(verstring, "\015\012");
2911 ssh->v_c = snewn(len + 1, char);
2912 memcpy(ssh->v_c, verstring, len);
2916 logeventf(ssh, "We claim version: %.*s",
2917 strcspn(verstring, "\015\012"), verstring);
2918 s_write(ssh, verstring, strlen(verstring));
2922 static int do_ssh_init(Ssh ssh, unsigned char c)
2924 static const char protoname[] = "SSH-";
2926 struct do_ssh_init_state {
2935 crState(do_ssh_init_state);
2939 /* Search for a line beginning with the protocol name prefix in
2942 for (s->i = 0; protoname[s->i]; s->i++) {
2943 if ((char)c != protoname[s->i]) goto no;
2953 s->vstrsize = sizeof(protoname) + 16;
2954 s->vstring = snewn(s->vstrsize, char);
2955 strcpy(s->vstring, protoname);
2956 s->vslen = strlen(protoname);
2959 if (s->vslen >= s->vstrsize - 1) {
2961 s->vstring = sresize(s->vstring, s->vstrsize, char);
2963 s->vstring[s->vslen++] = c;
2966 s->version[s->i] = '\0';
2968 } else if (s->i < sizeof(s->version) - 1)
2969 s->version[s->i++] = c;
2970 } else if (c == '\012')
2972 crReturn(1); /* get another char */
2975 ssh->agentfwd_enabled = FALSE;
2976 ssh->rdpkt2_state.incoming_sequence = 0;
2978 s->vstring[s->vslen] = 0;
2979 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2980 logeventf(ssh, "Server version: %s", s->vstring);
2981 ssh_detect_bugs(ssh, s->vstring);
2984 * Decide which SSH protocol version to support.
2987 /* Anything strictly below "2.0" means protocol 1 is supported. */
2988 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2989 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2990 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2992 if (conf_get_int(ssh->conf, CONF_sshprot) == 0 && !s->proto1) {
2993 bombout(("SSH protocol version 1 required by configuration but "
2994 "not provided by server"));
2997 if (conf_get_int(ssh->conf, CONF_sshprot) == 3 && !s->proto2) {
2998 bombout(("SSH protocol version 2 required by configuration but "
2999 "not provided by server"));
3003 if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1))
3008 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
3010 /* Send the version string, if we haven't already */
3011 if (conf_get_int(ssh->conf, CONF_sshprot) != 3)
3012 ssh_send_verstring(ssh, protoname, s->version);
3014 if (ssh->version == 2) {
3017 * Record their version string.
3019 len = strcspn(s->vstring, "\015\012");
3020 ssh->v_s = snewn(len + 1, char);
3021 memcpy(ssh->v_s, s->vstring, len);
3025 * Initialise SSH-2 protocol.
3027 ssh->protocol = ssh2_protocol;
3028 ssh2_protocol_setup(ssh);
3029 ssh->s_rdpkt = ssh2_rdpkt;
3032 * Initialise SSH-1 protocol.
3034 ssh->protocol = ssh1_protocol;
3035 ssh1_protocol_setup(ssh);
3036 ssh->s_rdpkt = ssh1_rdpkt;
3038 if (ssh->version == 2)
3039 do_ssh2_transport(ssh, NULL, -1, NULL);
3041 update_specials_menu(ssh->frontend);
3042 ssh->state = SSH_STATE_BEFORE_SIZE;
3043 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3050 static int do_ssh_connection_init(Ssh ssh, unsigned char c)
3053 * Ordinary SSH begins with the banner "SSH-x.y-...". This is just
3054 * the ssh-connection part, extracted and given a trivial binary
3055 * packet protocol, so we replace 'SSH-' at the start with a new
3056 * name. In proper SSH style (though of course this part of the
3057 * proper SSH protocol _isn't_ subject to this kind of
3058 * DNS-domain-based extension), we define the new name in our
3061 static const char protoname[] =
3062 "SSHCONNECTION@putty.projects.tartarus.org-";
3064 struct do_ssh_connection_init_state {
3072 crState(do_ssh_connection_init_state);
3076 /* Search for a line beginning with the protocol name prefix in
3079 for (s->i = 0; protoname[s->i]; s->i++) {
3080 if ((char)c != protoname[s->i]) goto no;
3090 s->vstrsize = sizeof(protoname) + 16;
3091 s->vstring = snewn(s->vstrsize, char);
3092 strcpy(s->vstring, protoname);
3093 s->vslen = strlen(protoname);
3096 if (s->vslen >= s->vstrsize - 1) {
3098 s->vstring = sresize(s->vstring, s->vstrsize, char);
3100 s->vstring[s->vslen++] = c;
3103 s->version[s->i] = '\0';
3105 } else if (s->i < sizeof(s->version) - 1)
3106 s->version[s->i++] = c;
3107 } else if (c == '\012')
3109 crReturn(1); /* get another char */
3112 ssh->agentfwd_enabled = FALSE;
3113 ssh->rdpkt2_bare_state.incoming_sequence = 0;
3115 s->vstring[s->vslen] = 0;
3116 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
3117 logeventf(ssh, "Server version: %s", s->vstring);
3118 ssh_detect_bugs(ssh, s->vstring);
3121 * Decide which SSH protocol version to support. This is easy in
3122 * bare ssh-connection mode: only 2.0 is legal.
3124 if (ssh_versioncmp(s->version, "2.0") < 0) {
3125 bombout(("Server announces compatibility with SSH-1 in bare ssh-connection protocol"));
3128 if (conf_get_int(ssh->conf, CONF_sshprot) == 0) {
3129 bombout(("Bare ssh-connection protocol cannot be run in SSH-1-only mode"));
3135 logeventf(ssh, "Using bare ssh-connection protocol");
3137 /* Send the version string, if we haven't already */
3138 ssh_send_verstring(ssh, protoname, s->version);
3141 * Initialise bare connection protocol.
3143 ssh->protocol = ssh2_bare_connection_protocol;
3144 ssh2_bare_connection_protocol_setup(ssh);
3145 ssh->s_rdpkt = ssh2_bare_connection_rdpkt;
3147 update_specials_menu(ssh->frontend);
3148 ssh->state = SSH_STATE_BEFORE_SIZE;
3149 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3152 * Get authconn (really just conn) under way.
3154 do_ssh2_authconn(ssh, NULL, 0, NULL);
3161 static void ssh_process_incoming_data(Ssh ssh,
3162 unsigned char **data, int *datalen)
3164 struct Packet *pktin;
3166 pktin = ssh->s_rdpkt(ssh, data, datalen);
3168 ssh->protocol(ssh, NULL, 0, pktin);
3169 ssh_free_packet(pktin);
3173 static void ssh_queue_incoming_data(Ssh ssh,
3174 unsigned char **data, int *datalen)
3176 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
3181 static void ssh_process_queued_incoming_data(Ssh ssh)
3184 unsigned char *data;
3187 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
3188 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
3192 while (!ssh->frozen && len > 0)
3193 ssh_process_incoming_data(ssh, &data, &len);
3196 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
3200 static void ssh_set_frozen(Ssh ssh, int frozen)
3203 sk_set_frozen(ssh->s, frozen);
3204 ssh->frozen = frozen;
3207 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
3209 /* Log raw data, if we're in that mode. */
3211 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
3212 0, NULL, NULL, 0, NULL);
3214 crBegin(ssh->ssh_gotdata_crstate);
3217 * To begin with, feed the characters one by one to the
3218 * protocol initialisation / selection function do_ssh_init().
3219 * When that returns 0, we're done with the initial greeting
3220 * exchange and can move on to packet discipline.
3223 int ret; /* need not be kept across crReturn */
3225 crReturnV; /* more data please */
3226 ret = ssh->do_ssh_init(ssh, *data);
3234 * We emerge from that loop when the initial negotiation is
3235 * over and we have selected an s_rdpkt function. Now pass
3236 * everything to s_rdpkt, and then pass the resulting packets
3237 * to the proper protocol handler.
3241 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
3243 ssh_queue_incoming_data(ssh, &data, &datalen);
3244 /* This uses up all data and cannot cause anything interesting
3245 * to happen; indeed, for anything to happen at all, we must
3246 * return, so break out. */
3248 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
3249 /* This uses up some or all data, and may freeze the
3251 ssh_process_queued_incoming_data(ssh);
3253 /* This uses up some or all data, and may freeze the
3255 ssh_process_incoming_data(ssh, &data, &datalen);
3257 /* FIXME this is probably EBW. */
3258 if (ssh->state == SSH_STATE_CLOSED)
3261 /* We're out of data. Go and get some more. */
3267 static int ssh_do_close(Ssh ssh, int notify_exit)
3270 struct ssh_channel *c;
3272 ssh->state = SSH_STATE_CLOSED;
3273 expire_timer_context(ssh);
3278 notify_remote_exit(ssh->frontend);
3283 * Now we must shut down any port- and X-forwarded channels going
3284 * through this connection.
3286 if (ssh->channels) {
3287 while (NULL != (c = index234(ssh->channels, 0))) {
3290 x11_close(c->u.x11.xconn);
3293 case CHAN_SOCKDATA_DORMANT:
3294 pfd_close(c->u.pfd.pf);
3297 del234(ssh->channels, c); /* moving next one to index 0 */
3298 if (ssh->version == 2)
3299 bufchain_clear(&c->v.v2.outbuffer);
3304 * Go through port-forwardings, and close any associated
3305 * listening sockets.
3307 if (ssh->portfwds) {
3308 struct ssh_portfwd *pf;
3309 while (NULL != (pf = index234(ssh->portfwds, 0))) {
3310 /* Dispose of any listening socket. */
3312 pfl_terminate(pf->local);
3313 del234(ssh->portfwds, pf); /* moving next one to index 0 */
3316 freetree234(ssh->portfwds);
3317 ssh->portfwds = NULL;
3321 * Also stop attempting to connection-share.
3323 if (ssh->connshare) {
3324 sharestate_free(ssh->connshare);
3325 ssh->connshare = NULL;
3331 static void ssh_socket_log(Plug plug, int type, SockAddr addr, int port,
3332 const char *error_msg, int error_code)
3334 Ssh ssh = (Ssh) plug;
3335 char addrbuf[256], *msg;
3337 if (ssh->attempting_connshare) {
3339 * While we're attempting connection sharing, don't loudly log
3340 * everything that happens. Real TCP connections need to be
3341 * logged when we _start_ trying to connect, because it might
3342 * be ages before they respond if something goes wrong; but
3343 * connection sharing is local and quick to respond, and it's
3344 * sufficient to simply wait and see whether it worked
3348 sk_getaddr(addr, addrbuf, lenof(addrbuf));
3351 if (sk_addr_needs_port(addr)) {
3352 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
3354 msg = dupprintf("Connecting to %s", addrbuf);
3357 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
3365 void ssh_connshare_log(Ssh ssh, int event, const char *logtext,
3366 const char *ds_err, const char *us_err)
3368 if (event == SHARE_NONE) {
3369 /* In this case, 'logtext' is an error message indicating a
3370 * reason why connection sharing couldn't be set up _at all_.
3371 * Failing that, ds_err and us_err indicate why we couldn't be
3372 * a downstream and an upstream respectively. */
3374 logeventf(ssh, "Could not set up connection sharing: %s", logtext);
3377 logeventf(ssh, "Could not set up connection sharing"
3378 " as downstream: %s", ds_err);
3380 logeventf(ssh, "Could not set up connection sharing"
3381 " as upstream: %s", us_err);
3383 } else if (event == SHARE_DOWNSTREAM) {
3384 /* In this case, 'logtext' is a local endpoint address */
3385 logeventf(ssh, "Using existing shared connection at %s", logtext);
3386 /* Also we should mention this in the console window to avoid
3387 * confusing users as to why this window doesn't behave the
3389 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3390 c_write_str(ssh,"Reusing a shared connection to this server.\r\n");
3392 } else if (event == SHARE_UPSTREAM) {
3393 /* In this case, 'logtext' is a local endpoint address too */
3394 logeventf(ssh, "Sharing this connection at %s", logtext);
3398 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
3401 Ssh ssh = (Ssh) plug;
3402 int need_notify = ssh_do_close(ssh, FALSE);
3405 if (!ssh->close_expected)
3406 error_msg = "Server unexpectedly closed network connection";
3408 error_msg = "Server closed network connection";
3411 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
3415 notify_remote_exit(ssh->frontend);
3418 logevent(error_msg);
3419 if (!ssh->close_expected || !ssh->clean_exit)
3420 connection_fatal(ssh->frontend, "%s", error_msg);
3424 static int ssh_receive(Plug plug, int urgent, char *data, int len)
3426 Ssh ssh = (Ssh) plug;
3427 ssh_gotdata(ssh, (unsigned char *)data, len);
3428 if (ssh->state == SSH_STATE_CLOSED) {
3429 ssh_do_close(ssh, TRUE);
3435 static void ssh_sent(Plug plug, int bufsize)
3437 Ssh ssh = (Ssh) plug;
3439 * If the send backlog on the SSH socket itself clears, we
3440 * should unthrottle the whole world if it was throttled.
3442 if (bufsize < SSH_MAX_BACKLOG)
3443 ssh_throttle_all(ssh, 0, bufsize);
3447 * Connect to specified host and port.
3448 * Returns an error message, or NULL on success.
3449 * Also places the canonical host name into `realhost'. It must be
3450 * freed by the caller.
3452 static const char *connect_to_host(Ssh ssh, char *host, int port,
3453 char **realhost, int nodelay, int keepalive)
3455 static const struct plug_function_table fn_table = {
3466 int addressfamily, sshprot;
3468 loghost = conf_get_str(ssh->conf, CONF_loghost);
3473 tmphost = dupstr(loghost);
3474 ssh->savedport = 22; /* default ssh port */
3477 * A colon suffix on the hostname string also lets us affect
3478 * savedport. (Unless there are multiple colons, in which case
3479 * we assume this is an unbracketed IPv6 literal.)
3481 colon = host_strrchr(tmphost, ':');
3482 if (colon && colon == host_strchr(tmphost, ':')) {
3485 ssh->savedport = atoi(colon);
3488 ssh->savedhost = host_strduptrim(tmphost);
3491 ssh->savedhost = host_strduptrim(host);
3493 port = 22; /* default ssh port */
3494 ssh->savedport = port;
3497 ssh->fn = &fn_table; /* make 'ssh' usable as a Plug */
3500 * Try connection-sharing, in case that means we don't open a
3501 * socket after all. ssh_connection_sharing_init will connect to a
3502 * previously established upstream if it can, and failing that,
3503 * establish a listening socket for _us_ to be the upstream. In
3504 * the latter case it will return NULL just as if it had done
3505 * nothing, because here we only need to care if we're a
3506 * downstream and need to do our connection setup differently.
3508 ssh->connshare = NULL;
3509 ssh->attempting_connshare = TRUE; /* affects socket logging behaviour */
3510 ssh->s = ssh_connection_sharing_init(ssh->savedhost, ssh->savedport,
3511 ssh->conf, ssh, &ssh->connshare);
3512 ssh->attempting_connshare = FALSE;
3513 if (ssh->s != NULL) {
3515 * We are a downstream.
3517 ssh->bare_connection = TRUE;
3518 ssh->do_ssh_init = do_ssh_connection_init;
3519 ssh->fullhostname = NULL;
3520 *realhost = dupstr(host); /* best we can do */
3523 * We're not a downstream, so open a normal socket.
3525 ssh->do_ssh_init = do_ssh_init;
3530 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
3531 logeventf(ssh, "Looking up host \"%s\"%s", host,
3532 (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
3533 (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
3534 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily);
3535 if ((err = sk_addr_error(addr)) != NULL) {
3539 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3541 ssh->s = new_connection(addr, *realhost, port,
3542 0, 1, nodelay, keepalive,
3543 (Plug) ssh, ssh->conf);
3544 if ((err = sk_socket_error(ssh->s)) != NULL) {
3546 notify_remote_exit(ssh->frontend);
3552 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3553 * send the version string too.
3555 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3558 if (sshprot == 3 && !ssh->bare_connection) {
3560 ssh_send_verstring(ssh, "SSH-", NULL);
3564 * loghost, if configured, overrides realhost.
3568 *realhost = dupstr(loghost);
3575 * Throttle or unthrottle the SSH connection.
3577 static void ssh_throttle_conn(Ssh ssh, int adjust)
3579 int old_count = ssh->conn_throttle_count;
3580 ssh->conn_throttle_count += adjust;
3581 assert(ssh->conn_throttle_count >= 0);
3582 if (ssh->conn_throttle_count && !old_count) {
3583 ssh_set_frozen(ssh, 1);
3584 } else if (!ssh->conn_throttle_count && old_count) {
3585 ssh_set_frozen(ssh, 0);
3590 * Throttle or unthrottle _all_ local data streams (for when sends
3591 * on the SSH connection itself back up).
3593 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3596 struct ssh_channel *c;
3598 if (enable == ssh->throttled_all)
3600 ssh->throttled_all = enable;
3601 ssh->overall_bufsize = bufsize;
3604 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3606 case CHAN_MAINSESSION:
3608 * This is treated separately, outside the switch.
3612 x11_override_throttle(c->u.x11.xconn, enable);
3615 /* Agent channels require no buffer management. */
3618 pfd_override_throttle(c->u.pfd.pf, enable);
3624 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3626 Ssh ssh = (Ssh) sshv;
3628 ssh->agent_response = reply;
3629 ssh->agent_response_len = replylen;
3631 if (ssh->version == 1)
3632 do_ssh1_login(ssh, NULL, -1, NULL);
3634 do_ssh2_authconn(ssh, NULL, -1, NULL);
3637 static void ssh_dialog_callback(void *sshv, int ret)
3639 Ssh ssh = (Ssh) sshv;
3641 ssh->user_response = ret;
3643 if (ssh->version == 1)
3644 do_ssh1_login(ssh, NULL, -1, NULL);
3646 do_ssh2_transport(ssh, NULL, -1, NULL);
3649 * This may have unfrozen the SSH connection, so do a
3652 ssh_process_queued_incoming_data(ssh);
3655 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3657 struct ssh_channel *c = (struct ssh_channel *)cv;
3659 void *sentreply = reply;
3661 c->u.a.outstanding_requests--;
3663 /* Fake SSH_AGENT_FAILURE. */
3664 sentreply = "\0\0\0\1\5";
3667 if (ssh->version == 2) {
3668 ssh2_add_channel_data(c, sentreply, replylen);
3671 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3672 PKT_INT, c->remoteid,
3674 PKT_DATA, sentreply, replylen,
3680 * If we've already seen an incoming EOF but haven't sent an
3681 * outgoing one, this may be the moment to send it.
3683 if (c->u.a.outstanding_requests == 0 && (c->closes & CLOSES_RCVD_EOF))
3684 sshfwd_write_eof(c);
3688 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3689 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3690 * => log `wire_reason'.
3692 static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
3693 int code, int clean_exit)
3697 client_reason = wire_reason;
3699 error = dupprintf("Disconnected: %s", client_reason);
3701 error = dupstr("Disconnected");
3703 if (ssh->version == 1) {
3704 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3706 } else if (ssh->version == 2) {
3707 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3708 ssh2_pkt_adduint32(pktout, code);
3709 ssh2_pkt_addstring(pktout, wire_reason);
3710 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3711 ssh2_pkt_send_noqueue(ssh, pktout);
3714 ssh->close_expected = TRUE;
3715 ssh->clean_exit = clean_exit;
3716 ssh_closing((Plug)ssh, error, 0, 0);
3720 int verify_ssh_manual_host_key(Ssh ssh, const char *fingerprint,
3721 const struct ssh_signkey *ssh2keytype,
3724 if (!conf_get_str_nthstrkey(ssh->conf, CONF_ssh_manual_hostkeys, 0)) {
3725 return -1; /* no manual keys configured */
3730 * The fingerprint string we've been given will have things
3731 * like 'ssh-rsa 2048' at the front of it. Strip those off and
3732 * narrow down to just the colon-separated hex block at the
3733 * end of the string.
3735 const char *p = strrchr(fingerprint, ' ');
3736 fingerprint = p ? p+1 : fingerprint;
3737 /* Quick sanity checks, including making sure it's in lowercase */
3738 assert(strlen(fingerprint) == 16*3 - 1);
3739 assert(fingerprint[2] == ':');
3740 assert(fingerprint[strspn(fingerprint, "0123456789abcdef:")] == 0);
3742 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3744 return 1; /* success */
3749 * Construct the base64-encoded public key blob and see if
3752 unsigned char *binblob;
3754 int binlen, atoms, i;
3755 binblob = ssh2keytype->public_blob(ssh2keydata, &binlen);
3756 atoms = (binlen + 2) / 3;
3757 base64blob = snewn(atoms * 4 + 1, char);
3758 for (i = 0; i < atoms; i++)
3759 base64_encode_atom(binblob + 3*i, binlen - 3*i, base64blob + 4*i);
3760 base64blob[atoms * 4] = '\0';
3762 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3765 return 1; /* success */
3774 * Handle the key exchange and user authentication phases.
3776 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
3777 struct Packet *pktin)
3780 unsigned char cookie[8], *ptr;
3781 struct MD5Context md5c;
3782 struct do_ssh1_login_state {
3785 unsigned char *rsabuf, *keystr1, *keystr2;
3786 unsigned long supported_ciphers_mask, supported_auths_mask;
3787 int tried_publickey, tried_agent;
3788 int tis_auth_refused, ccard_auth_refused;
3789 unsigned char session_id[16];
3791 void *publickey_blob;
3792 int publickey_bloblen;
3793 char *publickey_comment;
3794 int publickey_encrypted;
3795 prompts_t *cur_prompt;
3798 unsigned char request[5], *response, *p;
3808 struct RSAKey servkey, hostkey;
3810 crState(do_ssh1_login_state);
3817 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
3818 bombout(("Public key packet not received"));
3822 logevent("Received public keys");
3824 ptr = ssh_pkt_getdata(pktin, 8);
3826 bombout(("SSH-1 public key packet stopped before random cookie"));
3829 memcpy(cookie, ptr, 8);
3831 if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) ||
3832 !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) {
3833 bombout(("Failed to read SSH-1 public keys from public key packet"));
3838 * Log the host key fingerprint.
3842 logevent("Host key fingerprint is:");
3843 strcpy(logmsg, " ");
3844 s->hostkey.comment = NULL;
3845 rsa_fingerprint(logmsg + strlen(logmsg),
3846 sizeof(logmsg) - strlen(logmsg), &s->hostkey);
3850 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3851 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3852 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
3853 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
3854 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
3856 ssh->v1_local_protoflags =
3857 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3858 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
3861 MD5Update(&md5c, s->keystr2, s->hostkey.bytes);
3862 MD5Update(&md5c, s->keystr1, s->servkey.bytes);
3863 MD5Update(&md5c, cookie, 8);
3864 MD5Final(s->session_id, &md5c);
3866 for (i = 0; i < 32; i++)
3867 ssh->session_key[i] = random_byte();
3870 * Verify that the `bits' and `bytes' parameters match.
3872 if (s->hostkey.bits > s->hostkey.bytes * 8 ||
3873 s->servkey.bits > s->servkey.bytes * 8) {
3874 bombout(("SSH-1 public keys were badly formatted"));
3878 s->len = (s->hostkey.bytes > s->servkey.bytes ?
3879 s->hostkey.bytes : s->servkey.bytes);
3881 s->rsabuf = snewn(s->len, unsigned char);
3884 * Verify the host key.
3888 * First format the key into a string.
3890 int len = rsastr_len(&s->hostkey);
3891 char fingerprint[100];
3892 char *keystr = snewn(len, char);
3893 rsastr_fmt(keystr, &s->hostkey);
3894 rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey);
3896 /* First check against manually configured host keys. */
3897 s->dlgret = verify_ssh_manual_host_key(ssh, fingerprint, NULL, NULL);
3898 if (s->dlgret == 0) { /* did not match */
3899 bombout(("Host key did not appear in manually configured list"));
3902 } else if (s->dlgret < 0) { /* none configured; use standard handling */
3903 ssh_set_frozen(ssh, 1);
3904 s->dlgret = verify_ssh_host_key(ssh->frontend,
3905 ssh->savedhost, ssh->savedport,
3906 "rsa", keystr, fingerprint,
3907 ssh_dialog_callback, ssh);
3909 if (s->dlgret < 0) {
3913 bombout(("Unexpected data from server while waiting"
3914 " for user host key response"));
3917 } while (pktin || inlen > 0);
3918 s->dlgret = ssh->user_response;
3920 ssh_set_frozen(ssh, 0);
3922 if (s->dlgret == 0) {
3923 ssh_disconnect(ssh, "User aborted at host key verification",
3932 for (i = 0; i < 32; i++) {
3933 s->rsabuf[i] = ssh->session_key[i];
3935 s->rsabuf[i] ^= s->session_id[i];
3938 if (s->hostkey.bytes > s->servkey.bytes) {
3939 ret = rsaencrypt(s->rsabuf, 32, &s->servkey);
3941 ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey);
3943 ret = rsaencrypt(s->rsabuf, 32, &s->hostkey);
3945 ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey);
3948 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3952 logevent("Encrypted session key");
3955 int cipher_chosen = 0, warn = 0;
3956 char *cipher_string = NULL;
3958 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
3959 int next_cipher = conf_get_int_int(ssh->conf,
3960 CONF_ssh_cipherlist, i);
3961 if (next_cipher == CIPHER_WARN) {
3962 /* If/when we choose a cipher, warn about it */
3964 } else if (next_cipher == CIPHER_AES) {
3965 /* XXX Probably don't need to mention this. */
3966 logevent("AES not supported in SSH-1, skipping");
3968 switch (next_cipher) {
3969 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
3970 cipher_string = "3DES"; break;
3971 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
3972 cipher_string = "Blowfish"; break;
3973 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
3974 cipher_string = "single-DES"; break;
3976 if (s->supported_ciphers_mask & (1 << s->cipher_type))
3980 if (!cipher_chosen) {
3981 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
3982 bombout(("Server violates SSH-1 protocol by not "
3983 "supporting 3DES encryption"));
3985 /* shouldn't happen */
3986 bombout(("No supported ciphers found"));
3990 /* Warn about chosen cipher if necessary. */
3992 ssh_set_frozen(ssh, 1);
3993 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3994 ssh_dialog_callback, ssh);
3995 if (s->dlgret < 0) {
3999 bombout(("Unexpected data from server while waiting"
4000 " for user response"));
4003 } while (pktin || inlen > 0);
4004 s->dlgret = ssh->user_response;
4006 ssh_set_frozen(ssh, 0);
4007 if (s->dlgret == 0) {
4008 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
4015 switch (s->cipher_type) {
4016 case SSH_CIPHER_3DES:
4017 logevent("Using 3DES encryption");
4019 case SSH_CIPHER_DES:
4020 logevent("Using single-DES encryption");
4022 case SSH_CIPHER_BLOWFISH:
4023 logevent("Using Blowfish encryption");
4027 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
4028 PKT_CHAR, s->cipher_type,
4029 PKT_DATA, cookie, 8,
4030 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
4031 PKT_DATA, s->rsabuf, s->len,
4032 PKT_INT, ssh->v1_local_protoflags, PKT_END);
4034 logevent("Trying to enable encryption...");
4038 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
4039 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
4041 ssh->v1_cipher_ctx = ssh->cipher->make_context();
4042 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
4043 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
4045 ssh->crcda_ctx = crcda_make_context();
4046 logevent("Installing CRC compensation attack detector");
4048 if (s->servkey.modulus) {
4049 sfree(s->servkey.modulus);
4050 s->servkey.modulus = NULL;
4052 if (s->servkey.exponent) {
4053 sfree(s->servkey.exponent);
4054 s->servkey.exponent = NULL;
4056 if (s->hostkey.modulus) {
4057 sfree(s->hostkey.modulus);
4058 s->hostkey.modulus = NULL;
4060 if (s->hostkey.exponent) {
4061 sfree(s->hostkey.exponent);
4062 s->hostkey.exponent = NULL;
4066 if (pktin->type != SSH1_SMSG_SUCCESS) {
4067 bombout(("Encryption not successfully enabled"));
4071 logevent("Successfully started encryption");
4073 fflush(stdout); /* FIXME eh? */
4075 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
4076 int ret; /* need not be kept over crReturn */
4077 s->cur_prompt = new_prompts(ssh->frontend);
4078 s->cur_prompt->to_server = TRUE;
4079 s->cur_prompt->name = dupstr("SSH login name");
4080 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
4081 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4084 crWaitUntil(!pktin);
4085 ret = get_userpass_input(s->cur_prompt, in, inlen);
4090 * Failed to get a username. Terminate.
4092 free_prompts(s->cur_prompt);
4093 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
4096 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
4097 free_prompts(s->cur_prompt);
4100 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
4102 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
4104 if (flags & FLAG_INTERACTIVE &&
4105 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
4106 c_write_str(ssh, userlog);
4107 c_write_str(ssh, "\r\n");
4115 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
4116 /* We must not attempt PK auth. Pretend we've already tried it. */
4117 s->tried_publickey = s->tried_agent = 1;
4119 s->tried_publickey = s->tried_agent = 0;
4121 s->tis_auth_refused = s->ccard_auth_refused = 0;
4123 * Load the public half of any configured keyfile for later use.
4125 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4126 if (!filename_is_null(s->keyfile)) {
4128 logeventf(ssh, "Reading private key file \"%.150s\"",
4129 filename_to_str(s->keyfile));
4130 keytype = key_type(s->keyfile);
4131 if (keytype == SSH_KEYTYPE_SSH1) {
4133 if (rsakey_pubblob(s->keyfile,
4134 &s->publickey_blob, &s->publickey_bloblen,
4135 &s->publickey_comment, &error)) {
4136 s->publickey_encrypted = rsakey_encrypted(s->keyfile,
4140 logeventf(ssh, "Unable to load private key (%s)", error);
4141 msgbuf = dupprintf("Unable to load private key file "
4142 "\"%.150s\" (%s)\r\n",
4143 filename_to_str(s->keyfile),
4145 c_write_str(ssh, msgbuf);
4147 s->publickey_blob = NULL;
4151 logeventf(ssh, "Unable to use this key file (%s)",
4152 key_type_to_str(keytype));
4153 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4155 filename_to_str(s->keyfile),
4156 key_type_to_str(keytype));
4157 c_write_str(ssh, msgbuf);
4159 s->publickey_blob = NULL;
4162 s->publickey_blob = NULL;
4164 while (pktin->type == SSH1_SMSG_FAILURE) {
4165 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
4167 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
4169 * Attempt RSA authentication using Pageant.
4175 logevent("Pageant is running. Requesting keys.");
4177 /* Request the keys held by the agent. */
4178 PUT_32BIT(s->request, 1);
4179 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
4180 if (!agent_query(s->request, 5, &r, &s->responselen,
4181 ssh_agent_callback, ssh)) {
4185 bombout(("Unexpected data from server while waiting"
4186 " for agent response"));
4189 } while (pktin || inlen > 0);
4190 r = ssh->agent_response;
4191 s->responselen = ssh->agent_response_len;
4193 s->response = (unsigned char *) r;
4194 if (s->response && s->responselen >= 5 &&
4195 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
4196 s->p = s->response + 5;
4197 s->nkeys = toint(GET_32BIT(s->p));
4199 logeventf(ssh, "Pageant reported negative key count %d",
4204 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
4205 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4206 unsigned char *pkblob = s->p;
4210 do { /* do while (0) to make breaking easy */
4211 n = ssh1_read_bignum
4212 (s->p, toint(s->responselen-(s->p-s->response)),
4217 n = ssh1_read_bignum
4218 (s->p, toint(s->responselen-(s->p-s->response)),
4223 if (s->responselen - (s->p-s->response) < 4)
4225 s->commentlen = toint(GET_32BIT(s->p));
4227 if (s->commentlen < 0 ||
4228 toint(s->responselen - (s->p-s->response)) <
4231 s->commentp = (char *)s->p;
4232 s->p += s->commentlen;
4236 logevent("Pageant key list packet was truncated");
4240 if (s->publickey_blob) {
4241 if (!memcmp(pkblob, s->publickey_blob,
4242 s->publickey_bloblen)) {
4243 logeventf(ssh, "Pageant key #%d matches "
4244 "configured key file", s->keyi);
4245 s->tried_publickey = 1;
4247 /* Skip non-configured key */
4250 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
4251 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4252 PKT_BIGNUM, s->key.modulus, PKT_END);
4254 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4255 logevent("Key refused");
4258 logevent("Received RSA challenge");
4259 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4260 bombout(("Server's RSA challenge was badly formatted"));
4265 char *agentreq, *q, *ret;
4268 len = 1 + 4; /* message type, bit count */
4269 len += ssh1_bignum_length(s->key.exponent);
4270 len += ssh1_bignum_length(s->key.modulus);
4271 len += ssh1_bignum_length(s->challenge);
4272 len += 16; /* session id */
4273 len += 4; /* response format */
4274 agentreq = snewn(4 + len, char);
4275 PUT_32BIT(agentreq, len);
4277 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
4278 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
4280 q += ssh1_write_bignum(q, s->key.exponent);
4281 q += ssh1_write_bignum(q, s->key.modulus);
4282 q += ssh1_write_bignum(q, s->challenge);
4283 memcpy(q, s->session_id, 16);
4285 PUT_32BIT(q, 1); /* response format */
4286 if (!agent_query(agentreq, len + 4, &vret, &retlen,
4287 ssh_agent_callback, ssh)) {
4292 bombout(("Unexpected data from server"
4293 " while waiting for agent"
4297 } while (pktin || inlen > 0);
4298 vret = ssh->agent_response;
4299 retlen = ssh->agent_response_len;
4304 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
4305 logevent("Sending Pageant's response");
4306 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4307 PKT_DATA, ret + 5, 16,
4311 if (pktin->type == SSH1_SMSG_SUCCESS) {
4313 ("Pageant's response accepted");
4314 if (flags & FLAG_VERBOSE) {
4315 c_write_str(ssh, "Authenticated using"
4317 c_write(ssh, s->commentp,
4319 c_write_str(ssh, "\" from agent\r\n");
4324 ("Pageant's response not accepted");
4327 ("Pageant failed to answer challenge");
4331 logevent("No reply received from Pageant");
4334 freebn(s->key.exponent);
4335 freebn(s->key.modulus);
4336 freebn(s->challenge);
4341 if (s->publickey_blob && !s->tried_publickey)
4342 logevent("Configured key file not in Pageant");
4344 logevent("Failed to get reply from Pageant");
4349 if (s->publickey_blob && !s->tried_publickey) {
4351 * Try public key authentication with the specified
4354 int got_passphrase; /* need not be kept over crReturn */
4355 if (flags & FLAG_VERBOSE)
4356 c_write_str(ssh, "Trying public key authentication.\r\n");
4357 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4358 logeventf(ssh, "Trying public key \"%s\"",
4359 filename_to_str(s->keyfile));
4360 s->tried_publickey = 1;
4361 got_passphrase = FALSE;
4362 while (!got_passphrase) {
4364 * Get a passphrase, if necessary.
4366 char *passphrase = NULL; /* only written after crReturn */
4368 if (!s->publickey_encrypted) {
4369 if (flags & FLAG_VERBOSE)
4370 c_write_str(ssh, "No passphrase required.\r\n");
4373 int ret; /* need not be kept over crReturn */
4374 s->cur_prompt = new_prompts(ssh->frontend);
4375 s->cur_prompt->to_server = FALSE;
4376 s->cur_prompt->name = dupstr("SSH key passphrase");
4377 add_prompt(s->cur_prompt,
4378 dupprintf("Passphrase for key \"%.100s\": ",
4379 s->publickey_comment), FALSE);
4380 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4383 crWaitUntil(!pktin);
4384 ret = get_userpass_input(s->cur_prompt, in, inlen);
4388 /* Failed to get a passphrase. Terminate. */
4389 free_prompts(s->cur_prompt);
4390 ssh_disconnect(ssh, NULL, "Unable to authenticate",
4394 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
4395 free_prompts(s->cur_prompt);
4398 * Try decrypting key with passphrase.
4400 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4401 ret = loadrsakey(s->keyfile, &s->key, passphrase,
4404 smemclr(passphrase, strlen(passphrase));
4408 /* Correct passphrase. */
4409 got_passphrase = TRUE;
4410 } else if (ret == 0) {
4411 c_write_str(ssh, "Couldn't load private key from ");
4412 c_write_str(ssh, filename_to_str(s->keyfile));
4413 c_write_str(ssh, " (");
4414 c_write_str(ssh, error);
4415 c_write_str(ssh, ").\r\n");
4416 got_passphrase = FALSE;
4417 break; /* go and try something else */
4418 } else if (ret == -1) {
4419 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
4420 got_passphrase = FALSE;
4423 assert(0 && "unexpected return from loadrsakey()");
4424 got_passphrase = FALSE; /* placate optimisers */
4428 if (got_passphrase) {
4431 * Send a public key attempt.
4433 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4434 PKT_BIGNUM, s->key.modulus, PKT_END);
4437 if (pktin->type == SSH1_SMSG_FAILURE) {
4438 c_write_str(ssh, "Server refused our public key.\r\n");
4439 continue; /* go and try something else */
4441 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4442 bombout(("Bizarre response to offer of public key"));
4448 unsigned char buffer[32];
4449 Bignum challenge, response;
4451 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4452 bombout(("Server's RSA challenge was badly formatted"));
4455 response = rsadecrypt(challenge, &s->key);
4456 freebn(s->key.private_exponent);/* burn the evidence */
4458 for (i = 0; i < 32; i++) {
4459 buffer[i] = bignum_byte(response, 31 - i);
4463 MD5Update(&md5c, buffer, 32);
4464 MD5Update(&md5c, s->session_id, 16);
4465 MD5Final(buffer, &md5c);
4467 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4468 PKT_DATA, buffer, 16, PKT_END);
4475 if (pktin->type == SSH1_SMSG_FAILURE) {
4476 if (flags & FLAG_VERBOSE)
4477 c_write_str(ssh, "Failed to authenticate with"
4478 " our public key.\r\n");
4479 continue; /* go and try something else */
4480 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4481 bombout(("Bizarre response to RSA authentication response"));
4485 break; /* we're through! */
4491 * Otherwise, try various forms of password-like authentication.
4493 s->cur_prompt = new_prompts(ssh->frontend);
4495 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4496 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
4497 !s->tis_auth_refused) {
4498 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
4499 logevent("Requested TIS authentication");
4500 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
4502 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
4503 logevent("TIS authentication declined");
4504 if (flags & FLAG_INTERACTIVE)
4505 c_write_str(ssh, "TIS authentication refused.\r\n");
4506 s->tis_auth_refused = 1;
4511 char *instr_suf, *prompt;
4513 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4515 bombout(("TIS challenge packet was badly formed"));
4518 logevent("Received TIS challenge");
4519 s->cur_prompt->to_server = TRUE;
4520 s->cur_prompt->name = dupstr("SSH TIS authentication");
4521 /* Prompt heuristic comes from OpenSSH */
4522 if (memchr(challenge, '\n', challengelen)) {
4523 instr_suf = dupstr("");
4524 prompt = dupprintf("%.*s", challengelen, challenge);
4526 instr_suf = dupprintf("%.*s", challengelen, challenge);
4527 prompt = dupstr("Response: ");
4529 s->cur_prompt->instruction =
4530 dupprintf("Using TIS authentication.%s%s",
4531 (*instr_suf) ? "\n" : "",
4533 s->cur_prompt->instr_reqd = TRUE;
4534 add_prompt(s->cur_prompt, prompt, FALSE);
4538 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4539 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
4540 !s->ccard_auth_refused) {
4541 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
4542 logevent("Requested CryptoCard authentication");
4543 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
4545 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
4546 logevent("CryptoCard authentication declined");
4547 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4548 s->ccard_auth_refused = 1;
4553 char *instr_suf, *prompt;
4555 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4557 bombout(("CryptoCard challenge packet was badly formed"));
4560 logevent("Received CryptoCard challenge");
4561 s->cur_prompt->to_server = TRUE;
4562 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4563 s->cur_prompt->name_reqd = FALSE;
4564 /* Prompt heuristic comes from OpenSSH */
4565 if (memchr(challenge, '\n', challengelen)) {
4566 instr_suf = dupstr("");
4567 prompt = dupprintf("%.*s", challengelen, challenge);
4569 instr_suf = dupprintf("%.*s", challengelen, challenge);
4570 prompt = dupstr("Response: ");
4572 s->cur_prompt->instruction =
4573 dupprintf("Using CryptoCard authentication.%s%s",
4574 (*instr_suf) ? "\n" : "",
4576 s->cur_prompt->instr_reqd = TRUE;
4577 add_prompt(s->cur_prompt, prompt, FALSE);
4581 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4582 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4583 bombout(("No supported authentication methods available"));
4586 s->cur_prompt->to_server = TRUE;
4587 s->cur_prompt->name = dupstr("SSH password");
4588 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4589 ssh->username, ssh->savedhost),
4594 * Show password prompt, having first obtained it via a TIS
4595 * or CryptoCard exchange if we're doing TIS or CryptoCard
4599 int ret; /* need not be kept over crReturn */
4600 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4603 crWaitUntil(!pktin);
4604 ret = get_userpass_input(s->cur_prompt, in, inlen);
4609 * Failed to get a password (for example
4610 * because one was supplied on the command line
4611 * which has already failed to work). Terminate.
4613 free_prompts(s->cur_prompt);
4614 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4619 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4621 * Defence against traffic analysis: we send a
4622 * whole bunch of packets containing strings of
4623 * different lengths. One of these strings is the
4624 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4625 * The others are all random data in
4626 * SSH1_MSG_IGNORE packets. This way a passive
4627 * listener can't tell which is the password, and
4628 * hence can't deduce the password length.
4630 * Anybody with a password length greater than 16
4631 * bytes is going to have enough entropy in their
4632 * password that a listener won't find it _that_
4633 * much help to know how long it is. So what we'll
4636 * - if password length < 16, we send 15 packets
4637 * containing string lengths 1 through 15
4639 * - otherwise, we let N be the nearest multiple
4640 * of 8 below the password length, and send 8
4641 * packets containing string lengths N through
4642 * N+7. This won't obscure the order of
4643 * magnitude of the password length, but it will
4644 * introduce a bit of extra uncertainty.
4646 * A few servers can't deal with SSH1_MSG_IGNORE, at
4647 * least in this context. For these servers, we need
4648 * an alternative defence. We make use of the fact
4649 * that the password is interpreted as a C string:
4650 * so we can append a NUL, then some random data.
4652 * A few servers can deal with neither SSH1_MSG_IGNORE
4653 * here _nor_ a padded password string.
4654 * For these servers we are left with no defences
4655 * against password length sniffing.
4657 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4658 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4660 * The server can deal with SSH1_MSG_IGNORE, so
4661 * we can use the primary defence.
4663 int bottom, top, pwlen, i;
4666 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4668 bottom = 0; /* zero length passwords are OK! :-) */
4671 bottom = pwlen & ~7;
4675 assert(pwlen >= bottom && pwlen <= top);
4677 randomstr = snewn(top + 1, char);
4679 for (i = bottom; i <= top; i++) {
4681 defer_packet(ssh, s->pwpkt_type,
4682 PKT_STR,s->cur_prompt->prompts[0]->result,
4685 for (j = 0; j < i; j++) {
4687 randomstr[j] = random_byte();
4688 } while (randomstr[j] == '\0');
4690 randomstr[i] = '\0';
4691 defer_packet(ssh, SSH1_MSG_IGNORE,
4692 PKT_STR, randomstr, PKT_END);
4695 logevent("Sending password with camouflage packets");
4696 ssh_pkt_defersend(ssh);
4699 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4701 * The server can't deal with SSH1_MSG_IGNORE
4702 * but can deal with padded passwords, so we
4703 * can use the secondary defence.
4709 len = strlen(s->cur_prompt->prompts[0]->result);
4710 if (len < sizeof(string)) {
4712 strcpy(string, s->cur_prompt->prompts[0]->result);
4713 len++; /* cover the zero byte */
4714 while (len < sizeof(string)) {
4715 string[len++] = (char) random_byte();
4718 ss = s->cur_prompt->prompts[0]->result;
4720 logevent("Sending length-padded password");
4721 send_packet(ssh, s->pwpkt_type,
4722 PKT_INT, len, PKT_DATA, ss, len,
4726 * The server is believed unable to cope with
4727 * any of our password camouflage methods.
4730 len = strlen(s->cur_prompt->prompts[0]->result);
4731 logevent("Sending unpadded password");
4732 send_packet(ssh, s->pwpkt_type,
4734 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4738 send_packet(ssh, s->pwpkt_type,
4739 PKT_STR, s->cur_prompt->prompts[0]->result,
4742 logevent("Sent password");
4743 free_prompts(s->cur_prompt);
4745 if (pktin->type == SSH1_SMSG_FAILURE) {
4746 if (flags & FLAG_VERBOSE)
4747 c_write_str(ssh, "Access denied\r\n");
4748 logevent("Authentication refused");
4749 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4750 bombout(("Strange packet received, type %d", pktin->type));
4756 if (s->publickey_blob) {
4757 sfree(s->publickey_blob);
4758 sfree(s->publickey_comment);
4761 logevent("Authentication successful");
4766 static void ssh_channel_try_eof(struct ssh_channel *c)
4769 assert(c->pending_eof); /* precondition for calling us */
4771 return; /* can't close: not even opened yet */
4772 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4773 return; /* can't send EOF: pending outgoing data */
4775 c->pending_eof = FALSE; /* we're about to send it */
4776 if (ssh->version == 1) {
4777 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4779 c->closes |= CLOSES_SENT_EOF;
4781 struct Packet *pktout;
4782 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4783 ssh2_pkt_adduint32(pktout, c->remoteid);
4784 ssh2_pkt_send(ssh, pktout);
4785 c->closes |= CLOSES_SENT_EOF;
4786 ssh2_channel_check_close(c);
4790 Conf *sshfwd_get_conf(struct ssh_channel *c)
4796 void sshfwd_write_eof(struct ssh_channel *c)
4800 if (ssh->state == SSH_STATE_CLOSED)
4803 if (c->closes & CLOSES_SENT_EOF)
4806 c->pending_eof = TRUE;
4807 ssh_channel_try_eof(c);
4810 void sshfwd_unclean_close(struct ssh_channel *c, const char *err)
4814 if (ssh->state == SSH_STATE_CLOSED)
4819 x11_close(c->u.x11.xconn);
4820 logeventf(ssh, "Forwarded X11 connection terminated due to local "
4824 case CHAN_SOCKDATA_DORMANT:
4825 pfd_close(c->u.pfd.pf);
4826 logeventf(ssh, "Forwarded port closed due to local error: %s", err);
4829 c->type = CHAN_ZOMBIE;
4830 c->pending_eof = FALSE; /* this will confuse a zombie channel */
4832 ssh2_channel_check_close(c);
4835 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
4839 if (ssh->state == SSH_STATE_CLOSED)
4842 if (ssh->version == 1) {
4843 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
4844 PKT_INT, c->remoteid,
4845 PKT_INT, len, PKT_DATA, buf, len,
4848 * In SSH-1 we can return 0 here - implying that forwarded
4849 * connections are never individually throttled - because
4850 * the only circumstance that can cause throttling will be
4851 * the whole SSH connection backing up, in which case
4852 * _everything_ will be throttled as a whole.
4856 ssh2_add_channel_data(c, buf, len);
4857 return ssh2_try_send(c);
4861 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4866 if (ssh->state == SSH_STATE_CLOSED)
4869 if (ssh->version == 1) {
4870 buflimit = SSH1_BUFFER_LIMIT;
4872 buflimit = c->v.v2.locmaxwin;
4873 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
4875 if (c->throttling_conn && bufsize <= buflimit) {
4876 c->throttling_conn = 0;
4877 ssh_throttle_conn(ssh, -1);
4881 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
4883 struct queued_handler *qh = ssh->qhead;
4887 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
4890 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
4891 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
4894 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
4895 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
4899 ssh->qhead = qh->next;
4901 if (ssh->qhead->msg1 > 0) {
4902 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4903 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
4905 if (ssh->qhead->msg2 > 0) {
4906 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4907 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
4910 ssh->qhead = ssh->qtail = NULL;
4913 qh->handler(ssh, pktin, qh->ctx);
4918 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
4919 chandler_fn_t handler, void *ctx)
4921 struct queued_handler *qh;
4923 qh = snew(struct queued_handler);
4926 qh->handler = handler;
4930 if (ssh->qtail == NULL) {
4934 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4935 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
4938 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4939 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
4942 ssh->qtail->next = qh;
4947 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
4949 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
4951 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
4952 SSH2_MSG_REQUEST_SUCCESS)) {
4953 logeventf(ssh, "Remote port forwarding from %s enabled",
4956 logeventf(ssh, "Remote port forwarding from %s refused",
4959 rpf = del234(ssh->rportfwds, pf);
4961 pf->pfrec->remote = NULL;
4966 int ssh_alloc_sharing_rportfwd(Ssh ssh, const char *shost, int sport,
4969 struct ssh_rportfwd *pf = snew(struct ssh_rportfwd);
4972 pf->share_ctx = share_ctx;
4973 pf->shost = dupstr(shost);
4975 pf->sportdesc = NULL;
4976 if (!ssh->rportfwds) {
4977 assert(ssh->version == 2);
4978 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4980 if (add234(ssh->rportfwds, pf) != pf) {
4988 static void ssh_sharing_global_request_response(Ssh ssh, struct Packet *pktin,
4991 share_got_pkt_from_server(ctx, pktin->type,
4992 pktin->body, pktin->length);
4995 void ssh_sharing_queue_global_request(Ssh ssh, void *share_ctx)
4997 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, SSH2_MSG_REQUEST_FAILURE,
4998 ssh_sharing_global_request_response, share_ctx);
5001 static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
5003 struct ssh_portfwd *epf;
5007 if (!ssh->portfwds) {
5008 ssh->portfwds = newtree234(ssh_portcmp);
5011 * Go through the existing port forwardings and tag them
5012 * with status==DESTROY. Any that we want to keep will be
5013 * re-enabled (status==KEEP) as we go through the
5014 * configuration and find out which bits are the same as
5017 struct ssh_portfwd *epf;
5019 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5020 epf->status = DESTROY;
5023 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
5025 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
5026 char *kp, *kp2, *vp, *vp2;
5027 char address_family, type;
5028 int sport,dport,sserv,dserv;
5029 char *sports, *dports, *saddr, *host;
5033 address_family = 'A';
5035 if (*kp == 'A' || *kp == '4' || *kp == '6')
5036 address_family = *kp++;
5037 if (*kp == 'L' || *kp == 'R')
5040 if ((kp2 = host_strchr(kp, ':')) != NULL) {
5042 * There's a colon in the middle of the source port
5043 * string, which means that the part before it is
5044 * actually a source address.
5046 char *saddr_tmp = dupprintf("%.*s", (int)(kp2 - kp), kp);
5047 saddr = host_strduptrim(saddr_tmp);
5054 sport = atoi(sports);
5058 sport = net_service_lookup(sports);
5060 logeventf(ssh, "Service lookup failed for source"
5061 " port \"%s\"", sports);
5065 if (type == 'L' && !strcmp(val, "D")) {
5066 /* dynamic forwarding */
5073 /* ordinary forwarding */
5075 vp2 = vp + host_strcspn(vp, ":");
5076 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
5080 dport = atoi(dports);
5084 dport = net_service_lookup(dports);
5086 logeventf(ssh, "Service lookup failed for destination"
5087 " port \"%s\"", dports);
5092 if (sport && dport) {
5093 /* Set up a description of the source port. */
5094 struct ssh_portfwd *pfrec, *epfrec;
5096 pfrec = snew(struct ssh_portfwd);
5098 pfrec->saddr = saddr;
5099 pfrec->sserv = sserv ? dupstr(sports) : NULL;
5100 pfrec->sport = sport;
5101 pfrec->daddr = host;
5102 pfrec->dserv = dserv ? dupstr(dports) : NULL;
5103 pfrec->dport = dport;
5104 pfrec->local = NULL;
5105 pfrec->remote = NULL;
5106 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
5107 address_family == '6' ? ADDRTYPE_IPV6 :
5110 epfrec = add234(ssh->portfwds, pfrec);
5111 if (epfrec != pfrec) {
5112 if (epfrec->status == DESTROY) {
5114 * We already have a port forwarding up and running
5115 * with precisely these parameters. Hence, no need
5116 * to do anything; simply re-tag the existing one
5119 epfrec->status = KEEP;
5122 * Anything else indicates that there was a duplicate
5123 * in our input, which we'll silently ignore.
5125 free_portfwd(pfrec);
5127 pfrec->status = CREATE;
5136 * Now go through and destroy any port forwardings which were
5139 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5140 if (epf->status == DESTROY) {
5143 message = dupprintf("%s port forwarding from %s%s%d",
5144 epf->type == 'L' ? "local" :
5145 epf->type == 'R' ? "remote" : "dynamic",
5146 epf->saddr ? epf->saddr : "",
5147 epf->saddr ? ":" : "",
5150 if (epf->type != 'D') {
5151 char *msg2 = dupprintf("%s to %s:%d", message,
5152 epf->daddr, epf->dport);
5157 logeventf(ssh, "Cancelling %s", message);
5160 /* epf->remote or epf->local may be NULL if setting up a
5161 * forwarding failed. */
5163 struct ssh_rportfwd *rpf = epf->remote;
5164 struct Packet *pktout;
5167 * Cancel the port forwarding at the server
5170 if (ssh->version == 1) {
5172 * We cannot cancel listening ports on the
5173 * server side in SSH-1! There's no message
5174 * to support it. Instead, we simply remove
5175 * the rportfwd record from the local end
5176 * so that any connections the server tries
5177 * to make on it are rejected.
5180 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5181 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
5182 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
5184 ssh2_pkt_addstring(pktout, epf->saddr);
5185 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5186 /* XXX: rport_acceptall may not represent
5187 * what was used to open the original connection,
5188 * since it's reconfigurable. */
5189 ssh2_pkt_addstring(pktout, "");
5191 ssh2_pkt_addstring(pktout, "localhost");
5193 ssh2_pkt_adduint32(pktout, epf->sport);
5194 ssh2_pkt_send(ssh, pktout);
5197 del234(ssh->rportfwds, rpf);
5199 } else if (epf->local) {
5200 pfl_terminate(epf->local);
5203 delpos234(ssh->portfwds, i);
5205 i--; /* so we don't skip one in the list */
5209 * And finally, set up any new port forwardings (status==CREATE).
5211 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5212 if (epf->status == CREATE) {
5213 char *sportdesc, *dportdesc;
5214 sportdesc = dupprintf("%s%s%s%s%d%s",
5215 epf->saddr ? epf->saddr : "",
5216 epf->saddr ? ":" : "",
5217 epf->sserv ? epf->sserv : "",
5218 epf->sserv ? "(" : "",
5220 epf->sserv ? ")" : "");
5221 if (epf->type == 'D') {
5224 dportdesc = dupprintf("%s:%s%s%d%s",
5226 epf->dserv ? epf->dserv : "",
5227 epf->dserv ? "(" : "",
5229 epf->dserv ? ")" : "");
5232 if (epf->type == 'L') {
5233 char *err = pfl_listen(epf->daddr, epf->dport,
5234 epf->saddr, epf->sport,
5235 ssh, conf, &epf->local,
5236 epf->addressfamily);
5238 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
5239 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5240 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5241 sportdesc, dportdesc,
5242 err ? " failed: " : "", err ? err : "");
5245 } else if (epf->type == 'D') {
5246 char *err = pfl_listen(NULL, -1, epf->saddr, epf->sport,
5247 ssh, conf, &epf->local,
5248 epf->addressfamily);
5250 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
5251 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5252 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5254 err ? " failed: " : "", err ? err : "");
5259 struct ssh_rportfwd *pf;
5262 * Ensure the remote port forwardings tree exists.
5264 if (!ssh->rportfwds) {
5265 if (ssh->version == 1)
5266 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
5268 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5271 pf = snew(struct ssh_rportfwd);
5272 pf->share_ctx = NULL;
5273 pf->dhost = dupstr(epf->daddr);
5274 pf->dport = epf->dport;
5276 pf->shost = dupstr(epf->saddr);
5277 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5278 pf->shost = dupstr("");
5280 pf->shost = dupstr("localhost");
5282 pf->sport = epf->sport;
5283 if (add234(ssh->rportfwds, pf) != pf) {
5284 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
5285 epf->daddr, epf->dport);
5288 logeventf(ssh, "Requesting remote port %s"
5289 " forward to %s", sportdesc, dportdesc);
5291 pf->sportdesc = sportdesc;
5296 if (ssh->version == 1) {
5297 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
5298 PKT_INT, epf->sport,
5299 PKT_STR, epf->daddr,
5300 PKT_INT, epf->dport,
5302 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
5304 ssh_rportfwd_succfail, pf);
5306 struct Packet *pktout;
5307 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5308 ssh2_pkt_addstring(pktout, "tcpip-forward");
5309 ssh2_pkt_addbool(pktout, 1);/* want reply */
5310 ssh2_pkt_addstring(pktout, pf->shost);
5311 ssh2_pkt_adduint32(pktout, pf->sport);
5312 ssh2_pkt_send(ssh, pktout);
5314 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
5315 SSH2_MSG_REQUEST_FAILURE,
5316 ssh_rportfwd_succfail, pf);
5325 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
5328 int stringlen, bufsize;
5330 ssh_pkt_getstring(pktin, &string, &stringlen);
5331 if (string == NULL) {
5332 bombout(("Incoming terminal data packet was badly formed"));
5336 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
5338 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
5339 ssh->v1_stdout_throttling = 1;
5340 ssh_throttle_conn(ssh, +1);
5344 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
5346 /* Remote side is trying to open a channel to talk to our
5347 * X-Server. Give them back a local channel number. */
5348 struct ssh_channel *c;
5349 int remoteid = ssh_pkt_getuint32(pktin);
5351 logevent("Received X11 connect request");
5352 /* Refuse if X11 forwarding is disabled. */
5353 if (!ssh->X11_fwd_enabled) {
5354 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5355 PKT_INT, remoteid, PKT_END);
5356 logevent("Rejected X11 connect request");
5358 c = snew(struct ssh_channel);
5361 c->u.x11.xconn = x11_init(ssh->x11authtree, c, NULL, -1);
5362 c->remoteid = remoteid;
5363 c->halfopen = FALSE;
5364 c->localid = alloc_channel_id(ssh);
5366 c->pending_eof = FALSE;
5367 c->throttling_conn = 0;
5368 c->type = CHAN_X11; /* identify channel type */
5369 add234(ssh->channels, c);
5370 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5371 PKT_INT, c->remoteid, PKT_INT,
5372 c->localid, PKT_END);
5373 logevent("Opened X11 forward channel");
5377 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
5379 /* Remote side is trying to open a channel to talk to our
5380 * agent. Give them back a local channel number. */
5381 struct ssh_channel *c;
5382 int remoteid = ssh_pkt_getuint32(pktin);
5384 /* Refuse if agent forwarding is disabled. */
5385 if (!ssh->agentfwd_enabled) {
5386 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5387 PKT_INT, remoteid, PKT_END);
5389 c = snew(struct ssh_channel);
5391 c->remoteid = remoteid;
5392 c->halfopen = FALSE;
5393 c->localid = alloc_channel_id(ssh);
5395 c->pending_eof = FALSE;
5396 c->throttling_conn = 0;
5397 c->type = CHAN_AGENT; /* identify channel type */
5398 c->u.a.lensofar = 0;
5399 c->u.a.message = NULL;
5400 c->u.a.outstanding_requests = 0;
5401 add234(ssh->channels, c);
5402 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5403 PKT_INT, c->remoteid, PKT_INT, c->localid,
5408 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
5410 /* Remote side is trying to open a channel to talk to a
5411 * forwarded port. Give them back a local channel number. */
5412 struct ssh_rportfwd pf, *pfp;
5418 remoteid = ssh_pkt_getuint32(pktin);
5419 ssh_pkt_getstring(pktin, &host, &hostsize);
5420 port = ssh_pkt_getuint32(pktin);
5422 pf.dhost = dupprintf("%.*s", hostsize, host);
5424 pfp = find234(ssh->rportfwds, &pf, NULL);
5427 logeventf(ssh, "Rejected remote port open request for %s:%d",
5429 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5430 PKT_INT, remoteid, PKT_END);
5432 struct ssh_channel *c = snew(struct ssh_channel);
5435 logeventf(ssh, "Received remote port open request for %s:%d",
5437 err = pfd_connect(&c->u.pfd.pf, pf.dhost, port,
5438 c, ssh->conf, pfp->pfrec->addressfamily);
5440 logeventf(ssh, "Port open failed: %s", err);
5443 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5444 PKT_INT, remoteid, PKT_END);
5446 c->remoteid = remoteid;
5447 c->halfopen = FALSE;
5448 c->localid = alloc_channel_id(ssh);
5450 c->pending_eof = FALSE;
5451 c->throttling_conn = 0;
5452 c->type = CHAN_SOCKDATA; /* identify channel type */
5453 add234(ssh->channels, c);
5454 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5455 PKT_INT, c->remoteid, PKT_INT,
5456 c->localid, PKT_END);
5457 logevent("Forwarded port opened successfully");
5464 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5466 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5467 unsigned int localid = ssh_pkt_getuint32(pktin);
5468 struct ssh_channel *c;
5470 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5471 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5472 c->remoteid = localid;
5473 c->halfopen = FALSE;
5474 c->type = CHAN_SOCKDATA;
5475 c->throttling_conn = 0;
5476 pfd_confirm(c->u.pfd.pf);
5479 if (c && c->pending_eof) {
5481 * We have a pending close on this channel,
5482 * which we decided on before the server acked
5483 * the channel open. So now we know the
5484 * remoteid, we can close it again.
5486 ssh_channel_try_eof(c);
5490 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5492 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5493 struct ssh_channel *c;
5495 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5496 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5497 logevent("Forwarded connection refused by server");
5498 pfd_close(c->u.pfd.pf);
5499 del234(ssh->channels, c);
5504 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
5506 /* Remote side closes a channel. */
5507 unsigned i = ssh_pkt_getuint32(pktin);
5508 struct ssh_channel *c;
5509 c = find234(ssh->channels, &i, ssh_channelfind);
5510 if (c && !c->halfopen) {
5512 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
5513 !(c->closes & CLOSES_RCVD_EOF)) {
5515 * Received CHANNEL_CLOSE, which we translate into
5518 int send_close = FALSE;
5520 c->closes |= CLOSES_RCVD_EOF;
5525 x11_send_eof(c->u.x11.xconn);
5531 pfd_send_eof(c->u.pfd.pf);
5540 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
5541 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
5543 c->closes |= CLOSES_SENT_EOF;
5547 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
5548 !(c->closes & CLOSES_RCVD_CLOSE)) {
5550 if (!(c->closes & CLOSES_SENT_EOF)) {
5551 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
5552 " for which we never sent CHANNEL_CLOSE\n", i));
5555 c->closes |= CLOSES_RCVD_CLOSE;
5558 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
5559 !(c->closes & CLOSES_SENT_CLOSE)) {
5560 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
5561 PKT_INT, c->remoteid, PKT_END);
5562 c->closes |= CLOSES_SENT_CLOSE;
5565 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5566 ssh_channel_destroy(c);
5568 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5569 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
5570 "_CONFIRMATION", c ? "half-open" : "nonexistent",
5575 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5577 /* Data sent down one of our channels. */
5578 int i = ssh_pkt_getuint32(pktin);
5581 struct ssh_channel *c;
5583 ssh_pkt_getstring(pktin, &p, &len);
5585 c = find234(ssh->channels, &i, ssh_channelfind);
5590 bufsize = x11_send(c->u.x11.xconn, p, len);
5593 bufsize = pfd_send(c->u.pfd.pf, p, len);
5596 /* Data for an agent message. Buffer it. */
5598 if (c->u.a.lensofar < 4) {
5599 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
5600 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
5604 c->u.a.lensofar += l;
5606 if (c->u.a.lensofar == 4) {
5608 4 + GET_32BIT(c->u.a.msglen);
5609 c->u.a.message = snewn(c->u.a.totallen,
5611 memcpy(c->u.a.message, c->u.a.msglen, 4);
5613 if (c->u.a.lensofar >= 4 && len > 0) {
5615 min(c->u.a.totallen - c->u.a.lensofar,
5617 memcpy(c->u.a.message + c->u.a.lensofar, p,
5621 c->u.a.lensofar += l;
5623 if (c->u.a.lensofar == c->u.a.totallen) {
5626 c->u.a.outstanding_requests++;
5627 if (agent_query(c->u.a.message,
5630 ssh_agentf_callback, c))
5631 ssh_agentf_callback(c, reply, replylen);
5632 sfree(c->u.a.message);
5633 c->u.a.lensofar = 0;
5636 bufsize = 0; /* agent channels never back up */
5639 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5640 c->throttling_conn = 1;
5641 ssh_throttle_conn(ssh, +1);
5646 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5648 ssh->exitcode = ssh_pkt_getuint32(pktin);
5649 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5650 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5652 * In case `helpful' firewalls or proxies tack
5653 * extra human-readable text on the end of the
5654 * session which we might mistake for another
5655 * encrypted packet, we close the session once
5656 * we've sent EXIT_CONFIRMATION.
5658 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5661 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5662 static void ssh1_send_ttymode(void *data, char *mode, char *val)
5664 struct Packet *pktout = (struct Packet *)data;
5666 unsigned int arg = 0;
5667 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5668 if (i == lenof(ssh_ttymodes)) return;
5669 switch (ssh_ttymodes[i].type) {
5671 arg = ssh_tty_parse_specchar(val);
5674 arg = ssh_tty_parse_boolean(val);
5677 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5678 ssh2_pkt_addbyte(pktout, arg);
5681 int ssh_agent_forwarding_permitted(Ssh ssh)
5683 return conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists();
5686 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
5687 struct Packet *pktin)
5689 crBegin(ssh->do_ssh1_connection_crstate);
5691 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5692 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5693 ssh1_smsg_stdout_stderr_data;
5695 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5696 ssh1_msg_channel_open_confirmation;
5697 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5698 ssh1_msg_channel_open_failure;
5699 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5700 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5701 ssh1_msg_channel_close;
5702 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5703 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5705 if (ssh_agent_forwarding_permitted(ssh)) {
5706 logevent("Requesting agent forwarding");
5707 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5711 if (pktin->type != SSH1_SMSG_SUCCESS
5712 && pktin->type != SSH1_SMSG_FAILURE) {
5713 bombout(("Protocol confusion"));
5715 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5716 logevent("Agent forwarding refused");
5718 logevent("Agent forwarding enabled");
5719 ssh->agentfwd_enabled = TRUE;
5720 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5724 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
5726 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5728 if (!ssh->x11disp) {
5729 /* FIXME: return an error message from x11_setup_display */
5730 logevent("X11 forwarding not enabled: unable to"
5731 " initialise X display");
5733 ssh->x11auth = x11_invent_fake_auth
5734 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
5735 ssh->x11auth->disp = ssh->x11disp;
5737 logevent("Requesting X11 forwarding");
5738 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5739 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5740 PKT_STR, ssh->x11auth->protoname,
5741 PKT_STR, ssh->x11auth->datastring,
5742 PKT_INT, ssh->x11disp->screennum,
5745 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5746 PKT_STR, ssh->x11auth->protoname,
5747 PKT_STR, ssh->x11auth->datastring,
5753 if (pktin->type != SSH1_SMSG_SUCCESS
5754 && pktin->type != SSH1_SMSG_FAILURE) {
5755 bombout(("Protocol confusion"));
5757 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5758 logevent("X11 forwarding refused");
5760 logevent("X11 forwarding enabled");
5761 ssh->X11_fwd_enabled = TRUE;
5762 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5767 ssh_setup_portfwd(ssh, ssh->conf);
5768 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5770 if (!conf_get_int(ssh->conf, CONF_nopty)) {
5772 /* Unpick the terminal-speed string. */
5773 /* XXX perhaps we should allow no speeds to be sent. */
5774 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5775 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
5776 /* Send the pty request. */
5777 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5778 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
5779 ssh_pkt_adduint32(pkt, ssh->term_height);
5780 ssh_pkt_adduint32(pkt, ssh->term_width);
5781 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5782 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5783 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
5784 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5785 ssh_pkt_adduint32(pkt, ssh->ispeed);
5786 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5787 ssh_pkt_adduint32(pkt, ssh->ospeed);
5788 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5790 ssh->state = SSH_STATE_INTERMED;
5794 if (pktin->type != SSH1_SMSG_SUCCESS
5795 && pktin->type != SSH1_SMSG_FAILURE) {
5796 bombout(("Protocol confusion"));
5798 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5799 c_write_str(ssh, "Server refused to allocate pty\r\n");
5800 ssh->editing = ssh->echoing = 1;
5802 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5803 ssh->ospeed, ssh->ispeed);
5804 ssh->got_pty = TRUE;
5807 ssh->editing = ssh->echoing = 1;
5810 if (conf_get_int(ssh->conf, CONF_compression)) {
5811 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5815 if (pktin->type != SSH1_SMSG_SUCCESS
5816 && pktin->type != SSH1_SMSG_FAILURE) {
5817 bombout(("Protocol confusion"));
5819 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5820 c_write_str(ssh, "Server refused to compress\r\n");
5822 logevent("Started compression");
5823 ssh->v1_compressing = TRUE;
5824 ssh->cs_comp_ctx = zlib_compress_init();
5825 logevent("Initialised zlib (RFC1950) compression");
5826 ssh->sc_comp_ctx = zlib_decompress_init();
5827 logevent("Initialised zlib (RFC1950) decompression");
5831 * Start the shell or command.
5833 * Special case: if the first-choice command is an SSH-2
5834 * subsystem (hence not usable here) and the second choice
5835 * exists, we fall straight back to that.
5838 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
5840 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
5841 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
5842 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
5843 ssh->fallback_cmd = TRUE;
5846 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
5848 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
5849 logevent("Started session");
5852 ssh->state = SSH_STATE_SESSION;
5853 if (ssh->size_needed)
5854 ssh_size(ssh, ssh->term_width, ssh->term_height);
5855 if (ssh->eof_needed)
5856 ssh_special(ssh, TS_EOF);
5859 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5861 ssh->channels = newtree234(ssh_channelcmp);
5865 * By this point, most incoming packets are already being
5866 * handled by the dispatch table, and we need only pay
5867 * attention to the unusual ones.
5872 if (pktin->type == SSH1_SMSG_SUCCESS) {
5873 /* may be from EXEC_SHELL on some servers */
5874 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5875 /* may be from EXEC_SHELL on some servers
5876 * if no pty is available or in other odd cases. Ignore */
5878 bombout(("Strange packet received: type %d", pktin->type));
5883 int len = min(inlen, 512);
5884 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
5885 PKT_INT, len, PKT_DATA, in, len,
5897 * Handle the top-level SSH-2 protocol.
5899 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
5904 ssh_pkt_getstring(pktin, &msg, &msglen);
5905 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
5908 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
5910 /* log reason code in disconnect message */
5914 ssh_pkt_getstring(pktin, &msg, &msglen);
5915 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
5918 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
5920 /* Do nothing, because we're ignoring it! Duhh. */
5923 static void ssh1_protocol_setup(Ssh ssh)
5928 * Most messages are handled by the coroutines.
5930 for (i = 0; i < 256; i++)
5931 ssh->packet_dispatch[i] = NULL;
5934 * These special message types we install handlers for.
5936 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
5937 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
5938 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
5941 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
5942 struct Packet *pktin)
5944 unsigned char *in=(unsigned char*)vin;
5945 if (ssh->state == SSH_STATE_CLOSED)
5948 if (pktin && ssh->packet_dispatch[pktin->type]) {
5949 ssh->packet_dispatch[pktin->type](ssh, pktin);
5953 if (!ssh->protocol_initial_phase_done) {
5954 if (do_ssh1_login(ssh, in, inlen, pktin))
5955 ssh->protocol_initial_phase_done = TRUE;
5960 do_ssh1_connection(ssh, in, inlen, pktin);
5964 * Utility routine for decoding comma-separated strings in KEXINIT.
5966 static int in_commasep_string(char *needle, char *haystack, int haylen)
5969 if (!needle || !haystack) /* protect against null pointers */
5971 needlen = strlen(needle);
5974 * Is it at the start of the string?
5976 if (haylen >= needlen && /* haystack is long enough */
5977 !memcmp(needle, haystack, needlen) && /* initial match */
5978 (haylen == needlen || haystack[needlen] == ',')
5979 /* either , or EOS follows */
5983 * If not, search for the next comma and resume after that.
5984 * If no comma found, terminate.
5986 while (haylen > 0 && *haystack != ',')
5987 haylen--, haystack++;
5990 haylen--, haystack++; /* skip over comma itself */
5995 * Similar routine for checking whether we have the first string in a list.
5997 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
6000 if (!needle || !haystack) /* protect against null pointers */
6002 needlen = strlen(needle);
6004 * Is it at the start of the string?
6006 if (haylen >= needlen && /* haystack is long enough */
6007 !memcmp(needle, haystack, needlen) && /* initial match */
6008 (haylen == needlen || haystack[needlen] == ',')
6009 /* either , or EOS follows */
6017 * SSH-2 key creation method.
6018 * (Currently assumes 2 lots of any hash are sufficient to generate
6019 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
6021 #define SSH2_MKKEY_ITERS (2)
6022 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
6023 unsigned char *keyspace)
6025 const struct ssh_hash *h = ssh->kex->hash;
6027 /* First hlen bytes. */
6029 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6030 hash_mpint(h, s, K);
6031 h->bytes(s, H, h->hlen);
6032 h->bytes(s, &chr, 1);
6033 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
6034 h->final(s, keyspace);
6035 /* Next hlen bytes. */
6037 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6038 hash_mpint(h, s, K);
6039 h->bytes(s, H, h->hlen);
6040 h->bytes(s, keyspace, h->hlen);
6041 h->final(s, keyspace + h->hlen);
6045 * Handle the SSH-2 transport layer.
6047 static void do_ssh2_transport(Ssh ssh, void *vin, int inlen,
6048 struct Packet *pktin)
6050 unsigned char *in = (unsigned char *)vin;
6051 struct do_ssh2_transport_state {
6053 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
6054 Bignum p, g, e, f, K;
6057 int kex_init_value, kex_reply_value;
6058 const struct ssh_mac **maclist;
6060 const struct ssh2_cipher *cscipher_tobe;
6061 const struct ssh2_cipher *sccipher_tobe;
6062 const struct ssh_mac *csmac_tobe;
6063 const struct ssh_mac *scmac_tobe;
6064 const struct ssh_compress *cscomp_tobe;
6065 const struct ssh_compress *sccomp_tobe;
6066 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
6067 int hostkeylen, siglen, rsakeylen;
6068 void *hkey; /* actual host key */
6069 void *rsakey; /* for RSA kex */
6070 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
6071 int n_preferred_kex;
6072 const struct ssh_kexes *preferred_kex[KEX_MAX];
6073 int n_preferred_ciphers;
6074 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
6075 const struct ssh_compress *preferred_comp;
6076 int userauth_succeeded; /* for delayed compression */
6077 int pending_compression;
6078 int got_session_id, activated_authconn;
6079 struct Packet *pktout;
6084 crState(do_ssh2_transport_state);
6086 assert(!ssh->bare_connection);
6090 s->cscipher_tobe = s->sccipher_tobe = NULL;
6091 s->csmac_tobe = s->scmac_tobe = NULL;
6092 s->cscomp_tobe = s->sccomp_tobe = NULL;
6094 s->got_session_id = s->activated_authconn = FALSE;
6095 s->userauth_succeeded = FALSE;
6096 s->pending_compression = FALSE;
6099 * Be prepared to work around the buggy MAC problem.
6101 if (ssh->remote_bugs & BUG_SSH2_HMAC)
6102 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
6104 s->maclist = macs, s->nmacs = lenof(macs);
6107 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
6109 int i, j, k, commalist_started;
6112 * Set up the preferred key exchange. (NULL => warn below here)
6114 s->n_preferred_kex = 0;
6115 for (i = 0; i < KEX_MAX; i++) {
6116 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
6118 s->preferred_kex[s->n_preferred_kex++] =
6119 &ssh_diffiehellman_gex;
6122 s->preferred_kex[s->n_preferred_kex++] =
6123 &ssh_diffiehellman_group14;
6126 s->preferred_kex[s->n_preferred_kex++] =
6127 &ssh_diffiehellman_group1;
6130 s->preferred_kex[s->n_preferred_kex++] =
6134 /* Flag for later. Don't bother if it's the last in
6136 if (i < KEX_MAX - 1) {
6137 s->preferred_kex[s->n_preferred_kex++] = NULL;
6144 * Set up the preferred ciphers. (NULL => warn below here)
6146 s->n_preferred_ciphers = 0;
6147 for (i = 0; i < CIPHER_MAX; i++) {
6148 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
6149 case CIPHER_BLOWFISH:
6150 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
6153 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
6154 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
6158 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
6161 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
6163 case CIPHER_ARCFOUR:
6164 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
6167 /* Flag for later. Don't bother if it's the last in
6169 if (i < CIPHER_MAX - 1) {
6170 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
6177 * Set up preferred compression.
6179 if (conf_get_int(ssh->conf, CONF_compression))
6180 s->preferred_comp = &ssh_zlib;
6182 s->preferred_comp = &ssh_comp_none;
6185 * Enable queueing of outgoing auth- or connection-layer
6186 * packets while we are in the middle of a key exchange.
6188 ssh->queueing = TRUE;
6191 * Flag that KEX is in progress.
6193 ssh->kex_in_progress = TRUE;
6196 * Construct and send our key exchange packet.
6198 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
6199 for (i = 0; i < 16; i++)
6200 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
6201 /* List key exchange algorithms. */
6202 ssh2_pkt_addstring_start(s->pktout);
6203 commalist_started = 0;
6204 for (i = 0; i < s->n_preferred_kex; i++) {
6205 const struct ssh_kexes *k = s->preferred_kex[i];
6206 if (!k) continue; /* warning flag */
6207 for (j = 0; j < k->nkexes; j++) {
6208 if (commalist_started)
6209 ssh2_pkt_addstring_str(s->pktout, ",");
6210 ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
6211 commalist_started = 1;
6214 /* List server host key algorithms. */
6215 if (!s->got_session_id) {
6217 * In the first key exchange, we list all the algorithms
6218 * we're prepared to cope with.
6220 ssh2_pkt_addstring_start(s->pktout);
6221 for (i = 0; i < lenof(hostkey_algs); i++) {
6222 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
6223 if (i < lenof(hostkey_algs) - 1)
6224 ssh2_pkt_addstring_str(s->pktout, ",");
6228 * In subsequent key exchanges, we list only the kex
6229 * algorithm that was selected in the first key exchange,
6230 * so that we keep getting the same host key and hence
6231 * don't have to interrupt the user's session to ask for
6235 ssh2_pkt_addstring(s->pktout, ssh->hostkey->name);
6237 /* List encryption algorithms (client->server then server->client). */
6238 for (k = 0; k < 2; k++) {
6239 ssh2_pkt_addstring_start(s->pktout);
6240 commalist_started = 0;
6241 for (i = 0; i < s->n_preferred_ciphers; i++) {
6242 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6243 if (!c) continue; /* warning flag */
6244 for (j = 0; j < c->nciphers; j++) {
6245 if (commalist_started)
6246 ssh2_pkt_addstring_str(s->pktout, ",");
6247 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
6248 commalist_started = 1;
6252 /* List MAC algorithms (client->server then server->client). */
6253 for (j = 0; j < 2; j++) {
6254 ssh2_pkt_addstring_start(s->pktout);
6255 for (i = 0; i < s->nmacs; i++) {
6256 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
6257 if (i < s->nmacs - 1)
6258 ssh2_pkt_addstring_str(s->pktout, ",");
6261 /* List client->server compression algorithms,
6262 * then server->client compression algorithms. (We use the
6263 * same set twice.) */
6264 for (j = 0; j < 2; j++) {
6265 ssh2_pkt_addstring_start(s->pktout);
6266 assert(lenof(compressions) > 1);
6267 /* Prefer non-delayed versions */
6268 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
6269 /* We don't even list delayed versions of algorithms until
6270 * they're allowed to be used, to avoid a race. See the end of
6272 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
6273 ssh2_pkt_addstring_str(s->pktout, ",");
6274 ssh2_pkt_addstring_str(s->pktout,
6275 s->preferred_comp->delayed_name);
6277 for (i = 0; i < lenof(compressions); i++) {
6278 const struct ssh_compress *c = compressions[i];
6279 if (c != s->preferred_comp) {
6280 ssh2_pkt_addstring_str(s->pktout, ",");
6281 ssh2_pkt_addstring_str(s->pktout, c->name);
6282 if (s->userauth_succeeded && c->delayed_name) {
6283 ssh2_pkt_addstring_str(s->pktout, ",");
6284 ssh2_pkt_addstring_str(s->pktout, c->delayed_name);
6289 /* List client->server languages. Empty list. */
6290 ssh2_pkt_addstring_start(s->pktout);
6291 /* List server->client languages. Empty list. */
6292 ssh2_pkt_addstring_start(s->pktout);
6293 /* First KEX packet does _not_ follow, because we're not that brave. */
6294 ssh2_pkt_addbool(s->pktout, FALSE);
6296 ssh2_pkt_adduint32(s->pktout, 0);
6299 s->our_kexinitlen = s->pktout->length - 5;
6300 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
6301 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
6303 ssh2_pkt_send_noqueue(ssh, s->pktout);
6306 crWaitUntilV(pktin);
6309 * Now examine the other side's KEXINIT to see what we're up
6313 char *str, *preferred;
6316 if (pktin->type != SSH2_MSG_KEXINIT) {
6317 bombout(("expected key exchange packet from server"));
6321 ssh->hostkey = NULL;
6322 s->cscipher_tobe = NULL;
6323 s->sccipher_tobe = NULL;
6324 s->csmac_tobe = NULL;
6325 s->scmac_tobe = NULL;
6326 s->cscomp_tobe = NULL;
6327 s->sccomp_tobe = NULL;
6328 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
6330 pktin->savedpos += 16; /* skip garbage cookie */
6331 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
6333 bombout(("KEXINIT packet was incomplete"));
6338 for (i = 0; i < s->n_preferred_kex; i++) {
6339 const struct ssh_kexes *k = s->preferred_kex[i];
6343 for (j = 0; j < k->nkexes; j++) {
6344 if (!preferred) preferred = k->list[j]->name;
6345 if (in_commasep_string(k->list[j]->name, str, len)) {
6346 ssh->kex = k->list[j];
6355 bombout(("Couldn't agree a key exchange algorithm"
6356 " (available: %.*s)", len, str));
6360 * Note that the server's guess is considered wrong if it doesn't match
6361 * the first algorithm in our list, even if it's still the algorithm
6364 s->guessok = first_in_commasep_string(preferred, str, len);
6365 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
6367 bombout(("KEXINIT packet was incomplete"));
6370 for (i = 0; i < lenof(hostkey_algs); i++) {
6371 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
6372 ssh->hostkey = hostkey_algs[i];
6376 if (!ssh->hostkey) {
6377 bombout(("Couldn't agree a host key algorithm"
6378 " (available: %.*s)", len, str));
6382 s->guessok = s->guessok &&
6383 first_in_commasep_string(hostkey_algs[0]->name, str, len);
6384 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
6386 bombout(("KEXINIT packet was incomplete"));
6389 for (i = 0; i < s->n_preferred_ciphers; i++) {
6390 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6392 s->warn_cscipher = TRUE;
6394 for (j = 0; j < c->nciphers; j++) {
6395 if (in_commasep_string(c->list[j]->name, str, len)) {
6396 s->cscipher_tobe = c->list[j];
6401 if (s->cscipher_tobe)
6404 if (!s->cscipher_tobe) {
6405 bombout(("Couldn't agree a client-to-server cipher"
6406 " (available: %.*s)", len, str));
6410 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
6412 bombout(("KEXINIT packet was incomplete"));
6415 for (i = 0; i < s->n_preferred_ciphers; i++) {
6416 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6418 s->warn_sccipher = TRUE;
6420 for (j = 0; j < c->nciphers; j++) {
6421 if (in_commasep_string(c->list[j]->name, str, len)) {
6422 s->sccipher_tobe = c->list[j];
6427 if (s->sccipher_tobe)
6430 if (!s->sccipher_tobe) {
6431 bombout(("Couldn't agree a server-to-client cipher"
6432 " (available: %.*s)", len, str));
6436 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
6438 bombout(("KEXINIT packet was incomplete"));
6441 for (i = 0; i < s->nmacs; i++) {
6442 if (in_commasep_string(s->maclist[i]->name, str, len)) {
6443 s->csmac_tobe = s->maclist[i];
6447 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
6449 bombout(("KEXINIT packet was incomplete"));
6452 for (i = 0; i < s->nmacs; i++) {
6453 if (in_commasep_string(s->maclist[i]->name, str, len)) {
6454 s->scmac_tobe = s->maclist[i];
6458 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
6460 bombout(("KEXINIT packet was incomplete"));
6463 for (i = 0; i < lenof(compressions) + 1; i++) {
6464 const struct ssh_compress *c =
6465 i == 0 ? s->preferred_comp : compressions[i - 1];
6466 if (in_commasep_string(c->name, str, len)) {
6469 } else if (in_commasep_string(c->delayed_name, str, len)) {
6470 if (s->userauth_succeeded) {
6474 s->pending_compression = TRUE; /* try this later */
6478 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
6480 bombout(("KEXINIT packet was incomplete"));
6483 for (i = 0; i < lenof(compressions) + 1; i++) {
6484 const struct ssh_compress *c =
6485 i == 0 ? s->preferred_comp : compressions[i - 1];
6486 if (in_commasep_string(c->name, str, len)) {
6489 } else if (in_commasep_string(c->delayed_name, str, len)) {
6490 if (s->userauth_succeeded) {
6494 s->pending_compression = TRUE; /* try this later */
6498 if (s->pending_compression) {
6499 logevent("Server supports delayed compression; "
6500 "will try this later");
6502 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
6503 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
6504 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
6506 ssh->exhash = ssh->kex->hash->init();
6507 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
6508 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
6509 hash_string(ssh->kex->hash, ssh->exhash,
6510 s->our_kexinit, s->our_kexinitlen);
6511 sfree(s->our_kexinit);
6512 /* Include the type byte in the hash of server's KEXINIT */
6513 hash_string(ssh->kex->hash, ssh->exhash,
6514 pktin->body - 1, pktin->length + 1);
6517 ssh_set_frozen(ssh, 1);
6518 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
6520 ssh_dialog_callback, ssh);
6521 if (s->dlgret < 0) {
6525 bombout(("Unexpected data from server while"
6526 " waiting for user response"));
6529 } while (pktin || inlen > 0);
6530 s->dlgret = ssh->user_response;
6532 ssh_set_frozen(ssh, 0);
6533 if (s->dlgret == 0) {
6534 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
6540 if (s->warn_cscipher) {
6541 ssh_set_frozen(ssh, 1);
6542 s->dlgret = askalg(ssh->frontend,
6543 "client-to-server cipher",
6544 s->cscipher_tobe->name,
6545 ssh_dialog_callback, ssh);
6546 if (s->dlgret < 0) {
6550 bombout(("Unexpected data from server while"
6551 " waiting for user response"));
6554 } while (pktin || inlen > 0);
6555 s->dlgret = ssh->user_response;
6557 ssh_set_frozen(ssh, 0);
6558 if (s->dlgret == 0) {
6559 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6565 if (s->warn_sccipher) {
6566 ssh_set_frozen(ssh, 1);
6567 s->dlgret = askalg(ssh->frontend,
6568 "server-to-client cipher",
6569 s->sccipher_tobe->name,
6570 ssh_dialog_callback, ssh);
6571 if (s->dlgret < 0) {
6575 bombout(("Unexpected data from server while"
6576 " waiting for user response"));
6579 } while (pktin || inlen > 0);
6580 s->dlgret = ssh->user_response;
6582 ssh_set_frozen(ssh, 0);
6583 if (s->dlgret == 0) {
6584 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6590 if (s->ignorepkt) /* first_kex_packet_follows */
6591 crWaitUntilV(pktin); /* Ignore packet */
6594 if (ssh->kex->main_type == KEXTYPE_DH) {
6596 * Work out the number of bits of key we will need from the
6597 * key exchange. We start with the maximum key length of
6603 csbits = s->cscipher_tobe->keylen;
6604 scbits = s->sccipher_tobe->keylen;
6605 s->nbits = (csbits > scbits ? csbits : scbits);
6607 /* The keys only have hlen-bit entropy, since they're based on
6608 * a hash. So cap the key size at hlen bits. */
6609 if (s->nbits > ssh->kex->hash->hlen * 8)
6610 s->nbits = ssh->kex->hash->hlen * 8;
6613 * If we're doing Diffie-Hellman group exchange, start by
6614 * requesting a group.
6616 if (!ssh->kex->pdata) {
6617 logevent("Doing Diffie-Hellman group exchange");
6618 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
6620 * Work out how big a DH group we will need to allow that
6623 s->pbits = 512 << ((s->nbits - 1) / 64);
6624 if (s->pbits < DH_MIN_SIZE)
6625 s->pbits = DH_MIN_SIZE;
6626 if (s->pbits > DH_MAX_SIZE)
6627 s->pbits = DH_MAX_SIZE;
6628 if ((ssh->remote_bugs & BUG_SSH2_OLDGEX)) {
6629 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST_OLD);
6630 ssh2_pkt_adduint32(s->pktout, s->pbits);
6632 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6633 ssh2_pkt_adduint32(s->pktout, DH_MIN_SIZE);
6634 ssh2_pkt_adduint32(s->pktout, s->pbits);
6635 ssh2_pkt_adduint32(s->pktout, DH_MAX_SIZE);
6637 ssh2_pkt_send_noqueue(ssh, s->pktout);
6639 crWaitUntilV(pktin);
6640 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6641 bombout(("expected key exchange group packet from server"));
6644 s->p = ssh2_pkt_getmp(pktin);
6645 s->g = ssh2_pkt_getmp(pktin);
6646 if (!s->p || !s->g) {
6647 bombout(("unable to read mp-ints from incoming group packet"));
6650 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6651 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6652 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6654 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
6655 ssh->kex_ctx = dh_setup_group(ssh->kex);
6656 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6657 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6658 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6659 ssh->kex->groupname);
6662 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6663 ssh->kex->hash->text_name);
6665 * Now generate and send e for Diffie-Hellman.
6667 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6668 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6669 s->pktout = ssh2_pkt_init(s->kex_init_value);
6670 ssh2_pkt_addmp(s->pktout, s->e);
6671 ssh2_pkt_send_noqueue(ssh, s->pktout);
6673 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
6674 crWaitUntilV(pktin);
6675 if (pktin->type != s->kex_reply_value) {
6676 bombout(("expected key exchange reply packet from server"));
6679 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
6680 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6681 if (!s->hostkeydata) {
6682 bombout(("unable to parse key exchange reply packet"));
6685 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6686 s->f = ssh2_pkt_getmp(pktin);
6688 bombout(("unable to parse key exchange reply packet"));
6691 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6693 bombout(("unable to parse key exchange reply packet"));
6698 const char *err = dh_validate_f(ssh->kex_ctx, s->f);
6700 bombout(("key exchange reply failed validation: %s", err));
6704 s->K = dh_find_K(ssh->kex_ctx, s->f);
6706 /* We assume everything from now on will be quick, and it might
6707 * involve user interaction. */
6708 set_busy_status(ssh->frontend, BUSY_NOT);
6710 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6711 if (!ssh->kex->pdata) {
6712 if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX))
6713 hash_uint32(ssh->kex->hash, ssh->exhash, DH_MIN_SIZE);
6714 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
6715 if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX))
6716 hash_uint32(ssh->kex->hash, ssh->exhash, DH_MAX_SIZE);
6717 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
6718 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
6720 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
6721 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
6723 dh_cleanup(ssh->kex_ctx);
6725 if (!ssh->kex->pdata) {
6730 logeventf(ssh, "Doing RSA key exchange with hash %s",
6731 ssh->kex->hash->text_name);
6732 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
6734 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6737 crWaitUntilV(pktin);
6738 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
6739 bombout(("expected RSA public key packet from server"));
6743 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6744 if (!s->hostkeydata) {
6745 bombout(("unable to parse RSA public key packet"));
6748 hash_string(ssh->kex->hash, ssh->exhash,
6749 s->hostkeydata, s->hostkeylen);
6750 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6754 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
6756 bombout(("unable to parse RSA public key packet"));
6759 s->rsakeydata = snewn(s->rsakeylen, char);
6760 memcpy(s->rsakeydata, keydata, s->rsakeylen);
6763 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
6765 sfree(s->rsakeydata);
6766 bombout(("unable to parse RSA public key from server"));
6770 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
6773 * Next, set up a shared secret K, of precisely KLEN -
6774 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6775 * RSA key modulus and HLEN is the bit length of the hash
6779 int klen = ssh_rsakex_klen(s->rsakey);
6780 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
6782 unsigned char *kstr1, *kstr2, *outstr;
6783 int kstr1len, kstr2len, outstrlen;
6785 s->K = bn_power_2(nbits - 1);
6787 for (i = 0; i < nbits; i++) {
6789 byte = random_byte();
6791 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
6795 * Encode this as an mpint.
6797 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
6798 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
6799 PUT_32BIT(kstr2, kstr1len);
6800 memcpy(kstr2 + 4, kstr1, kstr1len);
6803 * Encrypt it with the given RSA key.
6805 outstrlen = (klen + 7) / 8;
6806 outstr = snewn(outstrlen, unsigned char);
6807 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
6808 outstr, outstrlen, s->rsakey);
6811 * And send it off in a return packet.
6813 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
6814 ssh2_pkt_addstring_start(s->pktout);
6815 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
6816 ssh2_pkt_send_noqueue(ssh, s->pktout);
6818 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
6825 ssh_rsakex_freekey(s->rsakey);
6827 crWaitUntilV(pktin);
6828 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
6829 sfree(s->rsakeydata);
6830 bombout(("expected signature packet from server"));
6834 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6836 bombout(("unable to parse signature packet"));
6840 sfree(s->rsakeydata);
6843 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
6844 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
6845 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
6847 ssh->kex_ctx = NULL;
6850 debug(("Exchange hash is:\n"));
6851 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
6855 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
6856 (char *)s->exchange_hash,
6857 ssh->kex->hash->hlen)) {
6858 bombout(("Server's host key did not match the signature supplied"));
6862 s->keystr = ssh->hostkey->fmtkey(s->hkey);
6863 if (!s->got_session_id) {
6865 * Authenticate remote host: verify host key. (We've already
6866 * checked the signature of the exchange hash.)
6868 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
6869 logevent("Host key fingerprint is:");
6870 logevent(s->fingerprint);
6871 /* First check against manually configured host keys. */
6872 s->dlgret = verify_ssh_manual_host_key(ssh, s->fingerprint,
6873 ssh->hostkey, s->hkey);
6874 if (s->dlgret == 0) { /* did not match */
6875 bombout(("Host key did not appear in manually configured list"));
6877 } else if (s->dlgret < 0) { /* none configured; use standard handling */
6878 ssh_set_frozen(ssh, 1);
6879 s->dlgret = verify_ssh_host_key(ssh->frontend,
6880 ssh->savedhost, ssh->savedport,
6881 ssh->hostkey->keytype, s->keystr,
6883 ssh_dialog_callback, ssh);
6884 if (s->dlgret < 0) {
6888 bombout(("Unexpected data from server while waiting"
6889 " for user host key response"));
6892 } while (pktin || inlen > 0);
6893 s->dlgret = ssh->user_response;
6895 ssh_set_frozen(ssh, 0);
6896 if (s->dlgret == 0) {
6897 ssh_disconnect(ssh, "Aborted at host key verification", NULL,
6902 sfree(s->fingerprint);
6904 * Save this host key, to check against the one presented in
6905 * subsequent rekeys.
6907 ssh->hostkey_str = s->keystr;
6910 * In a rekey, we never present an interactive host key
6911 * verification request to the user. Instead, we simply
6912 * enforce that the key we're seeing this time is identical to
6913 * the one we saw before.
6915 if (strcmp(ssh->hostkey_str, s->keystr)) {
6916 bombout(("Host key was different in repeat key exchange"));
6921 ssh->hostkey->freekey(s->hkey);
6924 * The exchange hash from the very first key exchange is also
6925 * the session id, used in session key construction and
6928 if (!s->got_session_id) {
6929 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
6930 memcpy(ssh->v2_session_id, s->exchange_hash,
6931 sizeof(s->exchange_hash));
6932 ssh->v2_session_id_len = ssh->kex->hash->hlen;
6933 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
6934 s->got_session_id = TRUE;
6938 * Send SSH2_MSG_NEWKEYS.
6940 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
6941 ssh2_pkt_send_noqueue(ssh, s->pktout);
6942 ssh->outgoing_data_size = 0; /* start counting from here */
6945 * We've sent client NEWKEYS, so create and initialise
6946 * client-to-server session keys.
6948 if (ssh->cs_cipher_ctx)
6949 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6950 ssh->cscipher = s->cscipher_tobe;
6951 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
6953 if (ssh->cs_mac_ctx)
6954 ssh->csmac->free_context(ssh->cs_mac_ctx);
6955 ssh->csmac = s->csmac_tobe;
6956 ssh->cs_mac_ctx = ssh->csmac->make_context();
6958 if (ssh->cs_comp_ctx)
6959 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6960 ssh->cscomp = s->cscomp_tobe;
6961 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
6964 * Set IVs on client-to-server keys. Here we use the exchange
6965 * hash from the _first_ key exchange.
6968 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6969 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6970 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
6971 assert((ssh->cscipher->keylen+7) / 8 <=
6972 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6973 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
6974 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
6975 assert(ssh->cscipher->blksize <=
6976 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6977 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
6978 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
6979 assert(ssh->csmac->len <=
6980 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6981 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
6982 smemclr(keyspace, sizeof(keyspace));
6985 logeventf(ssh, "Initialised %.200s client->server encryption",
6986 ssh->cscipher->text_name);
6987 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
6988 ssh->csmac->text_name);
6989 if (ssh->cscomp->text_name)
6990 logeventf(ssh, "Initialised %s compression",
6991 ssh->cscomp->text_name);
6994 * Now our end of the key exchange is complete, we can send all
6995 * our queued higher-layer packets.
6997 ssh->queueing = FALSE;
6998 ssh2_pkt_queuesend(ssh);
7001 * Expect SSH2_MSG_NEWKEYS from server.
7003 crWaitUntilV(pktin);
7004 if (pktin->type != SSH2_MSG_NEWKEYS) {
7005 bombout(("expected new-keys packet from server"));
7008 ssh->incoming_data_size = 0; /* start counting from here */
7011 * We've seen server NEWKEYS, so create and initialise
7012 * server-to-client session keys.
7014 if (ssh->sc_cipher_ctx)
7015 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7016 ssh->sccipher = s->sccipher_tobe;
7017 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
7019 if (ssh->sc_mac_ctx)
7020 ssh->scmac->free_context(ssh->sc_mac_ctx);
7021 ssh->scmac = s->scmac_tobe;
7022 ssh->sc_mac_ctx = ssh->scmac->make_context();
7024 if (ssh->sc_comp_ctx)
7025 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7026 ssh->sccomp = s->sccomp_tobe;
7027 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
7030 * Set IVs on server-to-client keys. Here we use the exchange
7031 * hash from the _first_ key exchange.
7034 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
7035 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7036 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
7037 assert((ssh->sccipher->keylen+7) / 8 <=
7038 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7039 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
7040 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
7041 assert(ssh->sccipher->blksize <=
7042 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7043 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
7044 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
7045 assert(ssh->scmac->len <=
7046 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7047 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
7048 smemclr(keyspace, sizeof(keyspace));
7050 logeventf(ssh, "Initialised %.200s server->client encryption",
7051 ssh->sccipher->text_name);
7052 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
7053 ssh->scmac->text_name);
7054 if (ssh->sccomp->text_name)
7055 logeventf(ssh, "Initialised %s decompression",
7056 ssh->sccomp->text_name);
7059 * Free shared secret.
7064 * Key exchange is over. Loop straight back round if we have a
7065 * deferred rekey reason.
7067 if (ssh->deferred_rekey_reason) {
7068 logevent(ssh->deferred_rekey_reason);
7070 ssh->deferred_rekey_reason = NULL;
7071 goto begin_key_exchange;
7075 * Otherwise, schedule a timer for our next rekey.
7077 ssh->kex_in_progress = FALSE;
7078 ssh->last_rekey = GETTICKCOUNT();
7079 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
7080 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7084 * Now we're encrypting. Begin returning 1 to the protocol main
7085 * function so that other things can run on top of the
7086 * transport. If we ever see a KEXINIT, we must go back to the
7089 * We _also_ go back to the start if we see pktin==NULL and
7090 * inlen negative, because this is a special signal meaning
7091 * `initiate client-driven rekey', and `in' contains a message
7092 * giving the reason for the rekey.
7094 * inlen==-1 means always initiate a rekey;
7095 * inlen==-2 means that userauth has completed successfully and
7096 * we should consider rekeying (for delayed compression).
7098 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
7099 (!pktin && inlen < 0))) {
7101 if (!ssh->protocol_initial_phase_done) {
7102 ssh->protocol_initial_phase_done = TRUE;
7104 * Allow authconn to initialise itself.
7106 do_ssh2_authconn(ssh, NULL, 0, NULL);
7111 logevent("Server initiated key re-exchange");
7115 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
7116 * delayed compression, if it's available.
7118 * draft-miller-secsh-compression-delayed-00 says that you
7119 * negotiate delayed compression in the first key exchange, and
7120 * both sides start compressing when the server has sent
7121 * USERAUTH_SUCCESS. This has a race condition -- the server
7122 * can't know when the client has seen it, and thus which incoming
7123 * packets it should treat as compressed.
7125 * Instead, we do the initial key exchange without offering the
7126 * delayed methods, but note if the server offers them; when we
7127 * get here, if a delayed method was available that was higher
7128 * on our list than what we got, we initiate a rekey in which we
7129 * _do_ list the delayed methods (and hopefully get it as a
7130 * result). Subsequent rekeys will do the same.
7132 assert(!s->userauth_succeeded); /* should only happen once */
7133 s->userauth_succeeded = TRUE;
7134 if (!s->pending_compression)
7135 /* Can't see any point rekeying. */
7136 goto wait_for_rekey; /* this is utterly horrid */
7137 /* else fall through to rekey... */
7138 s->pending_compression = FALSE;
7141 * Now we've decided to rekey.
7143 * Special case: if the server bug is set that doesn't
7144 * allow rekeying, we give a different log message and
7145 * continue waiting. (If such a server _initiates_ a rekey,
7146 * we process it anyway!)
7148 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
7149 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
7151 /* Reset the counters, so that at least this message doesn't
7152 * hit the event log _too_ often. */
7153 ssh->outgoing_data_size = 0;
7154 ssh->incoming_data_size = 0;
7155 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
7157 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7160 goto wait_for_rekey; /* this is still utterly horrid */
7162 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
7165 goto begin_key_exchange;
7171 * Add data to an SSH-2 channel output buffer.
7173 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
7176 bufchain_add(&c->v.v2.outbuffer, buf, len);
7180 * Attempt to send data on an SSH-2 channel.
7182 static int ssh2_try_send(struct ssh_channel *c)
7185 struct Packet *pktout;
7188 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
7191 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
7192 if ((unsigned)len > c->v.v2.remwindow)
7193 len = c->v.v2.remwindow;
7194 if ((unsigned)len > c->v.v2.remmaxpkt)
7195 len = c->v.v2.remmaxpkt;
7196 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
7197 ssh2_pkt_adduint32(pktout, c->remoteid);
7198 ssh2_pkt_addstring_start(pktout);
7199 ssh2_pkt_addstring_data(pktout, data, len);
7200 ssh2_pkt_send(ssh, pktout);
7201 bufchain_consume(&c->v.v2.outbuffer, len);
7202 c->v.v2.remwindow -= len;
7206 * After having sent as much data as we can, return the amount
7209 ret = bufchain_size(&c->v.v2.outbuffer);
7212 * And if there's no data pending but we need to send an EOF, send
7215 if (!ret && c->pending_eof)
7216 ssh_channel_try_eof(c);
7221 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
7224 if (c->closes & CLOSES_SENT_EOF)
7225 return; /* don't send on channels we've EOFed */
7226 bufsize = ssh2_try_send(c);
7229 case CHAN_MAINSESSION:
7230 /* stdin need not receive an unthrottle
7231 * notification since it will be polled */
7234 x11_unthrottle(c->u.x11.xconn);
7237 /* agent sockets are request/response and need no
7238 * buffer management */
7241 pfd_unthrottle(c->u.pfd.pf);
7247 static int ssh_is_simple(Ssh ssh)
7250 * We use the 'simple' variant of the SSH protocol if we're asked
7251 * to, except not if we're also doing connection-sharing (either
7252 * tunnelling our packets over an upstream or expecting to be
7253 * tunnelled over ourselves), since then the assumption that we
7254 * have only one channel to worry about is not true after all.
7256 return (conf_get_int(ssh->conf, CONF_ssh_simple) &&
7257 !ssh->bare_connection && !ssh->connshare);
7261 * Set up most of a new ssh_channel for SSH-2.
7263 static void ssh2_channel_init(struct ssh_channel *c)
7266 c->localid = alloc_channel_id(ssh);
7268 c->pending_eof = FALSE;
7269 c->throttling_conn = FALSE;
7270 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
7271 ssh_is_simple(ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
7272 c->v.v2.chanreq_head = NULL;
7273 c->v.v2.throttle_state = UNTHROTTLED;
7274 bufchain_init(&c->v.v2.outbuffer);
7278 * Construct the common parts of a CHANNEL_OPEN.
7280 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c, char *type)
7282 struct Packet *pktout;
7284 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7285 ssh2_pkt_addstring(pktout, type);
7286 ssh2_pkt_adduint32(pktout, c->localid);
7287 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7288 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7293 * CHANNEL_FAILURE doesn't come with any indication of what message
7294 * caused it, so we have to keep track of the outstanding
7295 * CHANNEL_REQUESTs ourselves.
7297 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
7298 cchandler_fn_t handler, void *ctx)
7300 struct outstanding_channel_request *ocr =
7301 snew(struct outstanding_channel_request);
7303 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7304 ocr->handler = handler;
7307 if (!c->v.v2.chanreq_head)
7308 c->v.v2.chanreq_head = ocr;
7310 c->v.v2.chanreq_tail->next = ocr;
7311 c->v.v2.chanreq_tail = ocr;
7315 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
7316 * NULL then a reply will be requested and the handler will be called
7317 * when it arrives. The returned packet is ready to have any
7318 * request-specific data added and be sent. Note that if a handler is
7319 * provided, it's essential that the request actually be sent.
7321 * The handler will usually be passed the response packet in pktin. If
7322 * pktin is NULL, this means that no reply will ever be forthcoming
7323 * (e.g. because the entire connection is being destroyed, or because
7324 * the server initiated channel closure before we saw the response)
7325 * and the handler should free any storage it's holding.
7327 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c, char *type,
7328 cchandler_fn_t handler, void *ctx)
7330 struct Packet *pktout;
7332 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7333 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7334 ssh2_pkt_adduint32(pktout, c->remoteid);
7335 ssh2_pkt_addstring(pktout, type);
7336 ssh2_pkt_addbool(pktout, handler != NULL);
7337 if (handler != NULL)
7338 ssh2_queue_chanreq_handler(c, handler, ctx);
7343 * Potentially enlarge the window on an SSH-2 channel.
7345 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
7347 static void ssh2_set_window(struct ssh_channel *c, int newwin)
7352 * Never send WINDOW_ADJUST for a channel that the remote side has
7353 * already sent EOF on; there's no point, since it won't be
7354 * sending any more data anyway. Ditto if _we've_ already sent
7357 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
7361 * Also, never widen the window for an X11 channel when we're
7362 * still waiting to see its initial auth and may yet hand it off
7365 if (c->type == CHAN_X11 && c->u.x11.initial)
7369 * If the remote end has a habit of ignoring maxpkt, limit the
7370 * window so that it has no choice (assuming it doesn't ignore the
7373 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
7374 newwin = OUR_V2_MAXPKT;
7377 * Only send a WINDOW_ADJUST if there's significantly more window
7378 * available than the other end thinks there is. This saves us
7379 * sending a WINDOW_ADJUST for every character in a shell session.
7381 * "Significant" is arbitrarily defined as half the window size.
7383 if (newwin / 2 >= c->v.v2.locwindow) {
7384 struct Packet *pktout;
7388 * In order to keep track of how much window the client
7389 * actually has available, we'd like it to acknowledge each
7390 * WINDOW_ADJUST. We can't do that directly, so we accompany
7391 * it with a CHANNEL_REQUEST that has to be acknowledged.
7393 * This is only necessary if we're opening the window wide.
7394 * If we're not, then throughput is being constrained by
7395 * something other than the maximum window size anyway.
7397 if (newwin == c->v.v2.locmaxwin &&
7398 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
7399 up = snew(unsigned);
7400 *up = newwin - c->v.v2.locwindow;
7401 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
7402 ssh2_handle_winadj_response, up);
7403 ssh2_pkt_send(ssh, pktout);
7405 if (c->v.v2.throttle_state != UNTHROTTLED)
7406 c->v.v2.throttle_state = UNTHROTTLING;
7408 /* Pretend the WINDOW_ADJUST was acked immediately. */
7409 c->v.v2.remlocwin = newwin;
7410 c->v.v2.throttle_state = THROTTLED;
7412 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7413 ssh2_pkt_adduint32(pktout, c->remoteid);
7414 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
7415 ssh2_pkt_send(ssh, pktout);
7416 c->v.v2.locwindow = newwin;
7421 * Find the channel associated with a message. If there's no channel,
7422 * or it's not properly open, make a noise about it and return NULL.
7424 static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
7426 unsigned localid = ssh_pkt_getuint32(pktin);
7427 struct ssh_channel *c;
7429 c = find234(ssh->channels, &localid, ssh_channelfind);
7431 (c->type != CHAN_SHARING && c->halfopen &&
7432 pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
7433 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
7434 char *buf = dupprintf("Received %s for %s channel %u",
7435 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
7437 c ? "half-open" : "nonexistent", localid);
7438 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
7445 static void ssh2_handle_winadj_response(struct ssh_channel *c,
7446 struct Packet *pktin, void *ctx)
7448 unsigned *sizep = ctx;
7451 * Winadj responses should always be failures. However, at least
7452 * one server ("boks_sshd") is known to return SUCCESS for channel
7453 * requests it's never heard of, such as "winadj@putty". Raised
7454 * with foxt.com as bug 090916-090424, but for the sake of a quiet
7455 * life, we don't worry about what kind of response we got.
7458 c->v.v2.remlocwin += *sizep;
7461 * winadj messages are only sent when the window is fully open, so
7462 * if we get an ack of one, we know any pending unthrottle is
7465 if (c->v.v2.throttle_state == UNTHROTTLING)
7466 c->v.v2.throttle_state = UNTHROTTLED;
7469 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
7471 struct ssh_channel *c = ssh2_channel_msg(ssh, pktin);
7472 struct outstanding_channel_request *ocr;
7475 if (c->type == CHAN_SHARING) {
7476 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7477 pktin->body, pktin->length);
7480 ocr = c->v.v2.chanreq_head;
7482 ssh2_msg_unexpected(ssh, pktin);
7485 ocr->handler(c, pktin, ocr->ctx);
7486 c->v.v2.chanreq_head = ocr->next;
7489 * We may now initiate channel-closing procedures, if that
7490 * CHANNEL_REQUEST was the last thing outstanding before we send
7493 ssh2_channel_check_close(c);
7496 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
7498 struct ssh_channel *c;
7499 c = ssh2_channel_msg(ssh, pktin);
7502 if (c->type == CHAN_SHARING) {
7503 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7504 pktin->body, pktin->length);
7507 if (!(c->closes & CLOSES_SENT_EOF)) {
7508 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
7509 ssh2_try_send_and_unthrottle(ssh, c);
7513 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
7517 struct ssh_channel *c;
7518 c = ssh2_channel_msg(ssh, pktin);
7521 if (c->type == CHAN_SHARING) {
7522 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7523 pktin->body, pktin->length);
7526 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
7527 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
7528 return; /* extended but not stderr */
7529 ssh_pkt_getstring(pktin, &data, &length);
7532 c->v.v2.locwindow -= length;
7533 c->v.v2.remlocwin -= length;
7535 case CHAN_MAINSESSION:
7537 from_backend(ssh->frontend, pktin->type ==
7538 SSH2_MSG_CHANNEL_EXTENDED_DATA,
7542 bufsize = x11_send(c->u.x11.xconn, data, length);
7545 bufsize = pfd_send(c->u.pfd.pf, data, length);
7548 while (length > 0) {
7549 if (c->u.a.lensofar < 4) {
7550 unsigned int l = min(4 - c->u.a.lensofar,
7552 memcpy(c->u.a.msglen + c->u.a.lensofar,
7556 c->u.a.lensofar += l;
7558 if (c->u.a.lensofar == 4) {
7560 4 + GET_32BIT(c->u.a.msglen);
7561 c->u.a.message = snewn(c->u.a.totallen,
7563 memcpy(c->u.a.message, c->u.a.msglen, 4);
7565 if (c->u.a.lensofar >= 4 && length > 0) {
7567 min(c->u.a.totallen - c->u.a.lensofar,
7569 memcpy(c->u.a.message + c->u.a.lensofar,
7573 c->u.a.lensofar += l;
7575 if (c->u.a.lensofar == c->u.a.totallen) {
7578 c->u.a.outstanding_requests++;
7579 if (agent_query(c->u.a.message,
7582 ssh_agentf_callback, c))
7583 ssh_agentf_callback(c, reply, replylen);
7584 sfree(c->u.a.message);
7585 c->u.a.message = NULL;
7586 c->u.a.lensofar = 0;
7593 * If it looks like the remote end hit the end of its window,
7594 * and we didn't want it to do that, think about using a
7597 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
7598 c->v.v2.locmaxwin < 0x40000000)
7599 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
7601 * If we are not buffering too much data,
7602 * enlarge the window again at the remote side.
7603 * If we are buffering too much, we may still
7604 * need to adjust the window if the server's
7607 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
7608 c->v.v2.locmaxwin - bufsize : 0);
7610 * If we're either buffering way too much data, or if we're
7611 * buffering anything at all and we're in "simple" mode,
7612 * throttle the whole channel.
7614 if ((bufsize > c->v.v2.locmaxwin || (ssh_is_simple(ssh) && bufsize>0))
7615 && !c->throttling_conn) {
7616 c->throttling_conn = 1;
7617 ssh_throttle_conn(ssh, +1);
7622 static void ssh_check_termination(Ssh ssh)
7624 if (ssh->version == 2 &&
7625 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
7626 (ssh->channels && count234(ssh->channels) == 0) &&
7627 !(ssh->connshare && share_ndownstreams(ssh->connshare) > 0)) {
7629 * We used to send SSH_MSG_DISCONNECT here, because I'd
7630 * believed that _every_ conforming SSH-2 connection had to
7631 * end with a disconnect being sent by at least one side;
7632 * apparently I was wrong and it's perfectly OK to
7633 * unceremoniously slam the connection shut when you're done,
7634 * and indeed OpenSSH feels this is more polite than sending a
7635 * DISCONNECT. So now we don't.
7637 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
7641 void ssh_sharing_downstream_connected(Ssh ssh, unsigned id,
7642 const char *peerinfo)
7645 logeventf(ssh, "Connection sharing downstream #%u connected from %s",
7648 logeventf(ssh, "Connection sharing downstream #%u connected", id);
7651 void ssh_sharing_downstream_disconnected(Ssh ssh, unsigned id)
7653 logeventf(ssh, "Connection sharing downstream #%u disconnected", id);
7654 ssh_check_termination(ssh);
7657 void ssh_sharing_logf(Ssh ssh, unsigned id, const char *logfmt, ...)
7662 va_start(ap, logfmt);
7663 buf = dupvprintf(logfmt, ap);
7666 logeventf(ssh, "Connection sharing downstream #%u: %s", id, buf);
7668 logeventf(ssh, "Connection sharing: %s", buf);
7672 static void ssh_channel_destroy(struct ssh_channel *c)
7677 case CHAN_MAINSESSION:
7678 ssh->mainchan = NULL;
7679 update_specials_menu(ssh->frontend);
7682 if (c->u.x11.xconn != NULL)
7683 x11_close(c->u.x11.xconn);
7684 logevent("Forwarded X11 connection terminated");
7687 sfree(c->u.a.message);
7690 if (c->u.pfd.pf != NULL)
7691 pfd_close(c->u.pfd.pf);
7692 logevent("Forwarded port closed");
7696 del234(ssh->channels, c);
7697 if (ssh->version == 2) {
7698 bufchain_clear(&c->v.v2.outbuffer);
7699 assert(c->v.v2.chanreq_head == NULL);
7704 * If that was the last channel left open, we might need to
7707 ssh_check_termination(ssh);
7710 static void ssh2_channel_check_close(struct ssh_channel *c)
7713 struct Packet *pktout;
7717 * If we've sent out our own CHANNEL_OPEN but not yet seen
7718 * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
7719 * it's too early to be sending close messages of any kind.
7724 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
7725 c->type == CHAN_ZOMBIE) &&
7726 !c->v.v2.chanreq_head &&
7727 !(c->closes & CLOSES_SENT_CLOSE)) {
7729 * We have both sent and received EOF (or the channel is a
7730 * zombie), and we have no outstanding channel requests, which
7731 * means the channel is in final wind-up. But we haven't sent
7732 * CLOSE, so let's do so now.
7734 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
7735 ssh2_pkt_adduint32(pktout, c->remoteid);
7736 ssh2_pkt_send(ssh, pktout);
7737 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
7740 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
7741 assert(c->v.v2.chanreq_head == NULL);
7743 * We have both sent and received CLOSE, which means we're
7744 * completely done with the channel.
7746 ssh_channel_destroy(c);
7750 static void ssh2_channel_got_eof(struct ssh_channel *c)
7752 if (c->closes & CLOSES_RCVD_EOF)
7753 return; /* already seen EOF */
7754 c->closes |= CLOSES_RCVD_EOF;
7756 if (c->type == CHAN_X11) {
7757 x11_send_eof(c->u.x11.xconn);
7758 } else if (c->type == CHAN_AGENT) {
7759 if (c->u.a.outstanding_requests == 0) {
7760 /* Manufacture an outgoing EOF in response to the incoming one. */
7761 sshfwd_write_eof(c);
7763 } else if (c->type == CHAN_SOCKDATA) {
7764 pfd_send_eof(c->u.pfd.pf);
7765 } else if (c->type == CHAN_MAINSESSION) {
7768 if (!ssh->sent_console_eof &&
7769 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
7771 * Either from_backend_eof told us that the front end
7772 * wants us to close the outgoing side of the connection
7773 * as soon as we see EOF from the far end, or else we've
7774 * unilaterally decided to do that because we've allocated
7775 * a remote pty and hence EOF isn't a particularly
7776 * meaningful concept.
7778 sshfwd_write_eof(c);
7780 ssh->sent_console_eof = TRUE;
7783 ssh2_channel_check_close(c);
7786 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
7788 struct ssh_channel *c;
7790 c = ssh2_channel_msg(ssh, pktin);
7793 if (c->type == CHAN_SHARING) {
7794 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7795 pktin->body, pktin->length);
7798 ssh2_channel_got_eof(c);
7801 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
7803 struct ssh_channel *c;
7805 c = ssh2_channel_msg(ssh, pktin);
7808 if (c->type == CHAN_SHARING) {
7809 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7810 pktin->body, pktin->length);
7815 * When we receive CLOSE on a channel, we assume it comes with an
7816 * implied EOF if we haven't seen EOF yet.
7818 ssh2_channel_got_eof(c);
7820 if (!(ssh->remote_bugs & BUG_SENDS_LATE_REQUEST_REPLY)) {
7822 * It also means we stop expecting to see replies to any
7823 * outstanding channel requests, so clean those up too.
7824 * (ssh_chanreq_init will enforce by assertion that we don't
7825 * subsequently put anything back on this list.)
7827 while (c->v.v2.chanreq_head) {
7828 struct outstanding_channel_request *ocr = c->v.v2.chanreq_head;
7829 ocr->handler(c, NULL, ocr->ctx);
7830 c->v.v2.chanreq_head = ocr->next;
7836 * And we also send an outgoing EOF, if we haven't already, on the
7837 * assumption that CLOSE is a pretty forceful announcement that
7838 * the remote side is doing away with the entire channel. (If it
7839 * had wanted to send us EOF and continue receiving data from us,
7840 * it would have just sent CHANNEL_EOF.)
7842 if (!(c->closes & CLOSES_SENT_EOF)) {
7844 * Make sure we don't read any more from whatever our local
7845 * data source is for this channel.
7848 case CHAN_MAINSESSION:
7849 ssh->send_ok = 0; /* stop trying to read from stdin */
7852 x11_override_throttle(c->u.x11.xconn, 1);
7855 pfd_override_throttle(c->u.pfd.pf, 1);
7860 * Abandon any buffered data we still wanted to send to this
7861 * channel. Receiving a CHANNEL_CLOSE is an indication that
7862 * the server really wants to get on and _destroy_ this
7863 * channel, and it isn't going to send us any further
7864 * WINDOW_ADJUSTs to permit us to send pending stuff.
7866 bufchain_clear(&c->v.v2.outbuffer);
7869 * Send outgoing EOF.
7871 sshfwd_write_eof(c);
7875 * Now process the actual close.
7877 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
7878 c->closes |= CLOSES_RCVD_CLOSE;
7879 ssh2_channel_check_close(c);
7883 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
7885 struct ssh_channel *c;
7887 c = ssh2_channel_msg(ssh, pktin);
7890 if (c->type == CHAN_SHARING) {
7891 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7892 pktin->body, pktin->length);
7895 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7896 c->remoteid = ssh_pkt_getuint32(pktin);
7897 c->halfopen = FALSE;
7898 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7899 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7901 if (c->type == CHAN_SOCKDATA_DORMANT) {
7902 c->type = CHAN_SOCKDATA;
7904 pfd_confirm(c->u.pfd.pf);
7905 } else if (c->type == CHAN_ZOMBIE) {
7907 * This case can occur if a local socket error occurred
7908 * between us sending out CHANNEL_OPEN and receiving
7909 * OPEN_CONFIRMATION. In this case, all we can do is
7910 * immediately initiate close proceedings now that we know the
7911 * server's id to put in the close message.
7913 ssh2_channel_check_close(c);
7916 * We never expect to receive OPEN_CONFIRMATION for any
7917 * *other* channel type (since only local-to-remote port
7918 * forwardings cause us to send CHANNEL_OPEN after the main
7919 * channel is live - all other auxiliary channel types are
7920 * initiated from the server end). It's safe to enforce this
7921 * by assertion rather than by ssh_disconnect, because the
7922 * real point is that we never constructed a half-open channel
7923 * structure in the first place with any type other than the
7926 assert(!"Funny channel type in ssh2_msg_channel_open_confirmation");
7930 ssh_channel_try_eof(c); /* in case we had a pending EOF */
7933 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
7935 static const char *const reasons[] = {
7936 "<unknown reason code>",
7937 "Administratively prohibited",
7939 "Unknown channel type",
7940 "Resource shortage",
7942 unsigned reason_code;
7943 char *reason_string;
7945 struct ssh_channel *c;
7947 c = ssh2_channel_msg(ssh, pktin);
7950 if (c->type == CHAN_SHARING) {
7951 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7952 pktin->body, pktin->length);
7955 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7957 if (c->type == CHAN_SOCKDATA_DORMANT) {
7958 reason_code = ssh_pkt_getuint32(pktin);
7959 if (reason_code >= lenof(reasons))
7960 reason_code = 0; /* ensure reasons[reason_code] in range */
7961 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
7962 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
7963 reasons[reason_code], reason_length, reason_string);
7965 pfd_close(c->u.pfd.pf);
7966 } else if (c->type == CHAN_ZOMBIE) {
7968 * This case can occur if a local socket error occurred
7969 * between us sending out CHANNEL_OPEN and receiving
7970 * OPEN_FAILURE. In this case, we need do nothing except allow
7971 * the code below to throw the half-open channel away.
7975 * We never expect to receive OPEN_FAILURE for any *other*
7976 * channel type (since only local-to-remote port forwardings
7977 * cause us to send CHANNEL_OPEN after the main channel is
7978 * live - all other auxiliary channel types are initiated from
7979 * the server end). It's safe to enforce this by assertion
7980 * rather than by ssh_disconnect, because the real point is
7981 * that we never constructed a half-open channel structure in
7982 * the first place with any type other than the above.
7984 assert(!"Funny channel type in ssh2_msg_channel_open_failure");
7987 del234(ssh->channels, c);
7991 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
7994 int typelen, want_reply;
7995 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
7996 struct ssh_channel *c;
7997 struct Packet *pktout;
7999 c = ssh2_channel_msg(ssh, pktin);
8002 if (c->type == CHAN_SHARING) {
8003 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8004 pktin->body, pktin->length);
8007 ssh_pkt_getstring(pktin, &type, &typelen);
8008 want_reply = ssh2_pkt_getbool(pktin);
8010 if (c->closes & CLOSES_SENT_CLOSE) {
8012 * We don't reply to channel requests after we've sent
8013 * CHANNEL_CLOSE for the channel, because our reply might
8014 * cross in the network with the other side's CHANNEL_CLOSE
8015 * and arrive after they have wound the channel up completely.
8021 * Having got the channel number, we now look at
8022 * the request type string to see if it's something
8025 if (c == ssh->mainchan) {
8027 * We recognise "exit-status" and "exit-signal" on
8028 * the primary channel.
8030 if (typelen == 11 &&
8031 !memcmp(type, "exit-status", 11)) {
8033 ssh->exitcode = ssh_pkt_getuint32(pktin);
8034 logeventf(ssh, "Server sent command exit status %d",
8036 reply = SSH2_MSG_CHANNEL_SUCCESS;
8038 } else if (typelen == 11 &&
8039 !memcmp(type, "exit-signal", 11)) {
8041 int is_plausible = TRUE, is_int = FALSE;
8042 char *fmt_sig = "", *fmt_msg = "";
8044 int msglen = 0, core = FALSE;
8045 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
8046 * provide an `int' for the signal, despite its
8047 * having been a `string' in the drafts of RFC 4254 since at
8048 * least 2001. (Fixed in session.c 1.147.) Try to
8049 * infer which we can safely parse it as. */
8051 unsigned char *p = pktin->body +
8053 long len = pktin->length - pktin->savedpos;
8054 unsigned long num = GET_32BIT(p); /* what is it? */
8055 /* If it's 0, it hardly matters; assume string */
8059 int maybe_int = FALSE, maybe_str = FALSE;
8060 #define CHECK_HYPOTHESIS(offset, result) \
8063 int q = toint(offset); \
8064 if (q >= 0 && q+4 <= len) { \
8065 q = toint(q + 4 + GET_32BIT(p+q)); \
8066 if (q >= 0 && q+4 <= len && \
8067 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
8072 CHECK_HYPOTHESIS(4+1, maybe_int);
8073 CHECK_HYPOTHESIS(4+num+1, maybe_str);
8074 #undef CHECK_HYPOTHESIS
8075 if (maybe_int && !maybe_str)
8077 else if (!maybe_int && maybe_str)
8080 /* Crikey. Either or neither. Panic. */
8081 is_plausible = FALSE;
8084 ssh->exitcode = 128; /* means `unknown signal' */
8087 /* Old non-standard OpenSSH. */
8088 int signum = ssh_pkt_getuint32(pktin);
8089 fmt_sig = dupprintf(" %d", signum);
8090 ssh->exitcode = 128 + signum;
8092 /* As per RFC 4254. */
8095 ssh_pkt_getstring(pktin, &sig, &siglen);
8096 /* Signal name isn't supposed to be blank, but
8097 * let's cope gracefully if it is. */
8099 fmt_sig = dupprintf(" \"%.*s\"",
8104 * Really hideous method of translating the
8105 * signal description back into a locally
8106 * meaningful number.
8111 #define TRANSLATE_SIGNAL(s) \
8112 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
8113 ssh->exitcode = 128 + SIG ## s
8115 TRANSLATE_SIGNAL(ABRT);
8118 TRANSLATE_SIGNAL(ALRM);
8121 TRANSLATE_SIGNAL(FPE);
8124 TRANSLATE_SIGNAL(HUP);
8127 TRANSLATE_SIGNAL(ILL);
8130 TRANSLATE_SIGNAL(INT);
8133 TRANSLATE_SIGNAL(KILL);
8136 TRANSLATE_SIGNAL(PIPE);
8139 TRANSLATE_SIGNAL(QUIT);
8142 TRANSLATE_SIGNAL(SEGV);
8145 TRANSLATE_SIGNAL(TERM);
8148 TRANSLATE_SIGNAL(USR1);
8151 TRANSLATE_SIGNAL(USR2);
8153 #undef TRANSLATE_SIGNAL
8155 ssh->exitcode = 128;
8157 core = ssh2_pkt_getbool(pktin);
8158 ssh_pkt_getstring(pktin, &msg, &msglen);
8160 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
8162 /* ignore lang tag */
8163 } /* else don't attempt to parse */
8164 logeventf(ssh, "Server exited on signal%s%s%s",
8165 fmt_sig, core ? " (core dumped)" : "",
8167 if (*fmt_sig) sfree(fmt_sig);
8168 if (*fmt_msg) sfree(fmt_msg);
8169 reply = SSH2_MSG_CHANNEL_SUCCESS;
8174 * This is a channel request we don't know
8175 * about, so we now either ignore the request
8176 * or respond with CHANNEL_FAILURE, depending
8179 reply = SSH2_MSG_CHANNEL_FAILURE;
8182 pktout = ssh2_pkt_init(reply);
8183 ssh2_pkt_adduint32(pktout, c->remoteid);
8184 ssh2_pkt_send(ssh, pktout);
8188 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
8191 int typelen, want_reply;
8192 struct Packet *pktout;
8194 ssh_pkt_getstring(pktin, &type, &typelen);
8195 want_reply = ssh2_pkt_getbool(pktin);
8198 * We currently don't support any global requests
8199 * at all, so we either ignore the request or
8200 * respond with REQUEST_FAILURE, depending on
8204 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
8205 ssh2_pkt_send(ssh, pktout);
8209 struct X11FakeAuth *ssh_sharing_add_x11_display(Ssh ssh, int authtype,
8213 struct X11FakeAuth *auth;
8216 * Make up a new set of fake X11 auth data, and add it to the tree
8217 * of currently valid ones with an indication of the sharing
8218 * context that it's relevant to.
8220 auth = x11_invent_fake_auth(ssh->x11authtree, authtype);
8221 auth->share_cs = share_cs;
8222 auth->share_chan = share_chan;
8227 void ssh_sharing_remove_x11_display(Ssh ssh, struct X11FakeAuth *auth)
8229 del234(ssh->x11authtree, auth);
8230 x11_free_fake_auth(auth);
8233 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
8241 struct ssh_channel *c;
8242 unsigned remid, winsize, pktsize;
8243 unsigned our_winsize_override = 0;
8244 struct Packet *pktout;
8246 ssh_pkt_getstring(pktin, &type, &typelen);
8247 c = snew(struct ssh_channel);
8250 remid = ssh_pkt_getuint32(pktin);
8251 winsize = ssh_pkt_getuint32(pktin);
8252 pktsize = ssh_pkt_getuint32(pktin);
8254 if (typelen == 3 && !memcmp(type, "x11", 3)) {
8257 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8258 addrstr = snewn(peeraddrlen+1, char);
8259 memcpy(addrstr, peeraddr, peeraddrlen);
8260 addrstr[peeraddrlen] = '\0';
8261 peerport = ssh_pkt_getuint32(pktin);
8263 logeventf(ssh, "Received X11 connect request from %s:%d",
8266 if (!ssh->X11_fwd_enabled && !ssh->connshare)
8267 error = "X11 forwarding is not enabled";
8269 c->u.x11.xconn = x11_init(ssh->x11authtree, c,
8272 c->u.x11.initial = TRUE;
8275 * If we are a connection-sharing upstream, then we should
8276 * initially present a very small window, adequate to take
8277 * the X11 initial authorisation packet but not much more.
8278 * Downstream will then present us a larger window (by
8279 * fiat of the connection-sharing protocol) and we can
8280 * guarantee to send a positive-valued WINDOW_ADJUST.
8283 our_winsize_override = 128;
8285 logevent("Opened X11 forward channel");
8289 } else if (typelen == 15 &&
8290 !memcmp(type, "forwarded-tcpip", 15)) {
8291 struct ssh_rportfwd pf, *realpf;
8294 ssh_pkt_getstring(pktin, &shost, &shostlen);/* skip address */
8295 pf.shost = dupprintf("%.*s", shostlen, shost);
8296 pf.sport = ssh_pkt_getuint32(pktin);
8297 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8298 peerport = ssh_pkt_getuint32(pktin);
8299 realpf = find234(ssh->rportfwds, &pf, NULL);
8300 logeventf(ssh, "Received remote port %s:%d open request "
8301 "from %s:%d", pf.shost, pf.sport, peeraddr, peerport);
8304 if (realpf == NULL) {
8305 error = "Remote port is not recognised";
8309 if (realpf->share_ctx) {
8311 * This port forwarding is on behalf of a
8312 * connection-sharing downstream, so abandon our own
8313 * channel-open procedure and just pass the message on
8316 share_got_pkt_from_server(realpf->share_ctx, pktin->type,
8317 pktin->body, pktin->length);
8322 err = pfd_connect(&c->u.pfd.pf, realpf->dhost, realpf->dport,
8323 c, ssh->conf, realpf->pfrec->addressfamily);
8324 logeventf(ssh, "Attempting to forward remote port to "
8325 "%s:%d", realpf->dhost, realpf->dport);
8327 logeventf(ssh, "Port open failed: %s", err);
8329 error = "Port open failed";
8331 logevent("Forwarded port opened successfully");
8332 c->type = CHAN_SOCKDATA;
8335 } else if (typelen == 22 &&
8336 !memcmp(type, "auth-agent@openssh.com", 22)) {
8337 if (!ssh->agentfwd_enabled)
8338 error = "Agent forwarding is not enabled";
8340 c->type = CHAN_AGENT; /* identify channel type */
8341 c->u.a.lensofar = 0;
8342 c->u.a.message = NULL;
8343 c->u.a.outstanding_requests = 0;
8346 error = "Unsupported channel type requested";
8349 c->remoteid = remid;
8350 c->halfopen = FALSE;
8352 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
8353 ssh2_pkt_adduint32(pktout, c->remoteid);
8354 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
8355 ssh2_pkt_addstring(pktout, error);
8356 ssh2_pkt_addstring(pktout, "en"); /* language tag */
8357 ssh2_pkt_send(ssh, pktout);
8358 logeventf(ssh, "Rejected channel open: %s", error);
8361 ssh2_channel_init(c);
8362 c->v.v2.remwindow = winsize;
8363 c->v.v2.remmaxpkt = pktsize;
8364 if (our_winsize_override) {
8365 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
8366 our_winsize_override;
8368 add234(ssh->channels, c);
8369 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
8370 ssh2_pkt_adduint32(pktout, c->remoteid);
8371 ssh2_pkt_adduint32(pktout, c->localid);
8372 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
8373 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8374 ssh2_pkt_send(ssh, pktout);
8378 void sshfwd_x11_sharing_handover(struct ssh_channel *c,
8379 void *share_cs, void *share_chan,
8380 const char *peer_addr, int peer_port,
8381 int endian, int protomajor, int protominor,
8382 const void *initial_data, int initial_len)
8385 * This function is called when we've just discovered that an X
8386 * forwarding channel on which we'd been handling the initial auth
8387 * ourselves turns out to be destined for a connection-sharing
8388 * downstream. So we turn the channel into a CHAN_SHARING, meaning
8389 * that we completely stop tracking windows and buffering data and
8390 * just pass more or less unmodified SSH messages back and forth.
8392 c->type = CHAN_SHARING;
8393 c->u.sharing.ctx = share_cs;
8394 share_setup_x11_channel(share_cs, share_chan,
8395 c->localid, c->remoteid, c->v.v2.remwindow,
8396 c->v.v2.remmaxpkt, c->v.v2.locwindow,
8397 peer_addr, peer_port, endian,
8398 protomajor, protominor,
8399 initial_data, initial_len);
8402 void sshfwd_x11_is_local(struct ssh_channel *c)
8405 * This function is called when we've just discovered that an X
8406 * forwarding channel is _not_ destined for a connection-sharing
8407 * downstream but we're going to handle it ourselves. We stop
8408 * presenting a cautiously small window and go into ordinary data
8411 c->u.x11.initial = FALSE;
8412 ssh2_set_window(c, ssh_is_simple(c->ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE);
8416 * Buffer banner messages for later display at some convenient point,
8417 * if we're going to display them.
8419 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
8421 /* Arbitrary limit to prevent unbounded inflation of buffer */
8422 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
8423 bufchain_size(&ssh->banner) <= 131072) {
8424 char *banner = NULL;
8426 ssh_pkt_getstring(pktin, &banner, &size);
8428 bufchain_add(&ssh->banner, banner, size);
8432 /* Helper function to deal with sending tty modes for "pty-req" */
8433 static void ssh2_send_ttymode(void *data, char *mode, char *val)
8435 struct Packet *pktout = (struct Packet *)data;
8437 unsigned int arg = 0;
8438 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
8439 if (i == lenof(ssh_ttymodes)) return;
8440 switch (ssh_ttymodes[i].type) {
8442 arg = ssh_tty_parse_specchar(val);
8445 arg = ssh_tty_parse_boolean(val);
8448 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
8449 ssh2_pkt_adduint32(pktout, arg);
8452 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
8455 struct ssh2_setup_x11_state {
8459 struct Packet *pktout;
8460 crStateP(ssh2_setup_x11_state, ctx);
8464 logevent("Requesting X11 forwarding");
8465 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
8467 ssh2_pkt_addbool(pktout, 0); /* many connections */
8468 ssh2_pkt_addstring(pktout, ssh->x11auth->protoname);
8469 ssh2_pkt_addstring(pktout, ssh->x11auth->datastring);
8470 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
8471 ssh2_pkt_send(ssh, pktout);
8473 /* Wait to be called back with either a response packet, or NULL
8474 * meaning clean up and free our data */
8478 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8479 logevent("X11 forwarding enabled");
8480 ssh->X11_fwd_enabled = TRUE;
8482 logevent("X11 forwarding refused");
8488 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
8491 struct ssh2_setup_agent_state {
8495 struct Packet *pktout;
8496 crStateP(ssh2_setup_agent_state, ctx);
8500 logevent("Requesting OpenSSH-style agent forwarding");
8501 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
8502 ssh2_setup_agent, s);
8503 ssh2_pkt_send(ssh, pktout);
8505 /* Wait to be called back with either a response packet, or NULL
8506 * meaning clean up and free our data */
8510 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8511 logevent("Agent forwarding enabled");
8512 ssh->agentfwd_enabled = TRUE;
8514 logevent("Agent forwarding refused");
8520 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
8523 struct ssh2_setup_pty_state {
8527 struct Packet *pktout;
8528 crStateP(ssh2_setup_pty_state, ctx);
8532 /* Unpick the terminal-speed string. */
8533 /* XXX perhaps we should allow no speeds to be sent. */
8534 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
8535 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
8536 /* Build the pty request. */
8537 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
8539 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
8540 ssh2_pkt_adduint32(pktout, ssh->term_width);
8541 ssh2_pkt_adduint32(pktout, ssh->term_height);
8542 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
8543 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
8544 ssh2_pkt_addstring_start(pktout);
8545 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
8546 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
8547 ssh2_pkt_adduint32(pktout, ssh->ispeed);
8548 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
8549 ssh2_pkt_adduint32(pktout, ssh->ospeed);
8550 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
8551 ssh2_pkt_send(ssh, pktout);
8552 ssh->state = SSH_STATE_INTERMED;
8554 /* Wait to be called back with either a response packet, or NULL
8555 * meaning clean up and free our data */
8559 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8560 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
8561 ssh->ospeed, ssh->ispeed);
8562 ssh->got_pty = TRUE;
8564 c_write_str(ssh, "Server refused to allocate pty\r\n");
8565 ssh->editing = ssh->echoing = 1;
8572 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
8575 struct ssh2_setup_env_state {
8577 int num_env, env_left, env_ok;
8580 struct Packet *pktout;
8581 crStateP(ssh2_setup_env_state, ctx);
8586 * Send environment variables.
8588 * Simplest thing here is to send all the requests at once, and
8589 * then wait for a whole bunch of successes or failures.
8595 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
8597 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
8598 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
8599 ssh2_pkt_addstring(pktout, key);
8600 ssh2_pkt_addstring(pktout, val);
8601 ssh2_pkt_send(ssh, pktout);
8606 logeventf(ssh, "Sent %d environment variables", s->num_env);
8611 s->env_left = s->num_env;
8613 while (s->env_left > 0) {
8614 /* Wait to be called back with either a response packet,
8615 * or NULL meaning clean up and free our data */
8617 if (!pktin) goto out;
8618 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
8623 if (s->env_ok == s->num_env) {
8624 logevent("All environment variables successfully set");
8625 } else if (s->env_ok == 0) {
8626 logevent("All environment variables refused");
8627 c_write_str(ssh, "Server refused to set environment variables\r\n");
8629 logeventf(ssh, "%d environment variables refused",
8630 s->num_env - s->env_ok);
8631 c_write_str(ssh, "Server refused to set all environment variables\r\n");
8639 * Handle the SSH-2 userauth and connection layers.
8641 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
8643 do_ssh2_authconn(ssh, NULL, 0, pktin);
8646 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
8650 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
8653 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
8654 struct Packet *pktin)
8656 struct do_ssh2_authconn_state {
8660 AUTH_TYPE_PUBLICKEY,
8661 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
8662 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
8664 AUTH_TYPE_GSSAPI, /* always QUIET */
8665 AUTH_TYPE_KEYBOARD_INTERACTIVE,
8666 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
8668 int done_service_req;
8669 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
8670 int tried_pubkey_config, done_agent;
8675 int kbd_inter_refused;
8676 int we_are_in, userauth_success;
8677 prompts_t *cur_prompt;
8682 void *publickey_blob;
8683 int publickey_bloblen;
8684 int publickey_encrypted;
8685 char *publickey_algorithm;
8686 char *publickey_comment;
8687 unsigned char agent_request[5], *agent_response, *agentp;
8688 int agent_responselen;
8689 unsigned char *pkblob_in_agent;
8691 char *pkblob, *alg, *commentp;
8692 int pklen, alglen, commentlen;
8693 int siglen, retlen, len;
8694 char *q, *agentreq, *ret;
8696 struct Packet *pktout;
8699 struct ssh_gss_library *gsslib;
8700 Ssh_gss_ctx gss_ctx;
8701 Ssh_gss_buf gss_buf;
8702 Ssh_gss_buf gss_rcvtok, gss_sndtok;
8703 Ssh_gss_name gss_srv_name;
8704 Ssh_gss_stat gss_stat;
8707 crState(do_ssh2_authconn_state);
8711 /* Register as a handler for all the messages this coroutine handles. */
8712 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
8713 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
8714 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
8715 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
8716 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
8717 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
8718 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
8719 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
8720 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
8721 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
8722 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
8723 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
8724 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
8725 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
8726 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
8727 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
8728 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
8729 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
8730 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
8731 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
8733 s->done_service_req = FALSE;
8734 s->we_are_in = s->userauth_success = FALSE;
8735 s->agent_response = NULL;
8737 s->tried_gssapi = FALSE;
8740 if (!ssh->bare_connection) {
8741 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
8743 * Request userauth protocol, and await a response to it.
8745 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8746 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
8747 ssh2_pkt_send(ssh, s->pktout);
8748 crWaitUntilV(pktin);
8749 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
8750 s->done_service_req = TRUE;
8752 if (!s->done_service_req) {
8754 * Request connection protocol directly, without authentication.
8756 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8757 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8758 ssh2_pkt_send(ssh, s->pktout);
8759 crWaitUntilV(pktin);
8760 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
8761 s->we_are_in = TRUE; /* no auth required */
8763 bombout(("Server refused service request"));
8768 s->we_are_in = TRUE;
8771 /* Arrange to be able to deal with any BANNERs that come in.
8772 * (We do this now as packets may come in during the next bit.) */
8773 bufchain_init(&ssh->banner);
8774 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
8775 ssh2_msg_userauth_banner;
8778 * Misc one-time setup for authentication.
8780 s->publickey_blob = NULL;
8781 if (!s->we_are_in) {
8784 * Load the public half of any configured public key file
8787 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
8788 if (!filename_is_null(s->keyfile)) {
8790 logeventf(ssh, "Reading private key file \"%.150s\"",
8791 filename_to_str(s->keyfile));
8792 keytype = key_type(s->keyfile);
8793 if (keytype == SSH_KEYTYPE_SSH2) {
8796 ssh2_userkey_loadpub(s->keyfile,
8797 &s->publickey_algorithm,
8798 &s->publickey_bloblen,
8799 &s->publickey_comment, &error);
8800 if (s->publickey_blob) {
8801 s->publickey_encrypted =
8802 ssh2_userkey_encrypted(s->keyfile, NULL);
8805 logeventf(ssh, "Unable to load private key (%s)",
8807 msgbuf = dupprintf("Unable to load private key file "
8808 "\"%.150s\" (%s)\r\n",
8809 filename_to_str(s->keyfile),
8811 c_write_str(ssh, msgbuf);
8816 logeventf(ssh, "Unable to use this key file (%s)",
8817 key_type_to_str(keytype));
8818 msgbuf = dupprintf("Unable to use key file \"%.150s\""
8820 filename_to_str(s->keyfile),
8821 key_type_to_str(keytype));
8822 c_write_str(ssh, msgbuf);
8824 s->publickey_blob = NULL;
8829 * Find out about any keys Pageant has (but if there's a
8830 * public key configured, filter out all others).
8833 s->agent_response = NULL;
8834 s->pkblob_in_agent = NULL;
8835 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
8839 logevent("Pageant is running. Requesting keys.");
8841 /* Request the keys held by the agent. */
8842 PUT_32BIT(s->agent_request, 1);
8843 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
8844 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
8845 ssh_agent_callback, ssh)) {
8849 bombout(("Unexpected data from server while"
8850 " waiting for agent response"));
8853 } while (pktin || inlen > 0);
8854 r = ssh->agent_response;
8855 s->agent_responselen = ssh->agent_response_len;
8857 s->agent_response = (unsigned char *) r;
8858 if (s->agent_response && s->agent_responselen >= 5 &&
8859 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
8862 p = s->agent_response + 5;
8863 s->nkeys = toint(GET_32BIT(p));
8866 * Vet the Pageant response to ensure that the key
8867 * count and blob lengths make sense.
8870 logeventf(ssh, "Pageant response contained a negative"
8871 " key count %d", s->nkeys);
8873 goto done_agent_query;
8875 unsigned char *q = p + 4;
8876 int lenleft = s->agent_responselen - 5 - 4;
8878 for (keyi = 0; keyi < s->nkeys; keyi++) {
8879 int bloblen, commentlen;
8881 logeventf(ssh, "Pageant response was truncated");
8883 goto done_agent_query;
8885 bloblen = toint(GET_32BIT(q));
8886 if (bloblen < 0 || bloblen > lenleft) {
8887 logeventf(ssh, "Pageant response was truncated");
8889 goto done_agent_query;
8891 lenleft -= 4 + bloblen;
8893 commentlen = toint(GET_32BIT(q));
8894 if (commentlen < 0 || commentlen > lenleft) {
8895 logeventf(ssh, "Pageant response was truncated");
8897 goto done_agent_query;
8899 lenleft -= 4 + commentlen;
8900 q += 4 + commentlen;
8905 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
8906 if (s->publickey_blob) {
8907 /* See if configured key is in agent. */
8908 for (keyi = 0; keyi < s->nkeys; keyi++) {
8909 s->pklen = toint(GET_32BIT(p));
8910 if (s->pklen == s->publickey_bloblen &&
8911 !memcmp(p+4, s->publickey_blob,
8912 s->publickey_bloblen)) {
8913 logeventf(ssh, "Pageant key #%d matches "
8914 "configured key file", keyi);
8916 s->pkblob_in_agent = p;
8920 p += toint(GET_32BIT(p)) + 4; /* comment */
8922 if (!s->pkblob_in_agent) {
8923 logevent("Configured key file not in Pageant");
8928 logevent("Failed to get reply from Pageant");
8936 * We repeat this whole loop, including the username prompt,
8937 * until we manage a successful authentication. If the user
8938 * types the wrong _password_, they can be sent back to the
8939 * beginning to try another username, if this is configured on.
8940 * (If they specify a username in the config, they are never
8941 * asked, even if they do give a wrong password.)
8943 * I think this best serves the needs of
8945 * - the people who have no configuration, no keys, and just
8946 * want to try repeated (username,password) pairs until they
8947 * type both correctly
8949 * - people who have keys and configuration but occasionally
8950 * need to fall back to passwords
8952 * - people with a key held in Pageant, who might not have
8953 * logged in to a particular machine before; so they want to
8954 * type a username, and then _either_ their key will be
8955 * accepted, _or_ they will type a password. If they mistype
8956 * the username they will want to be able to get back and
8959 s->got_username = FALSE;
8960 while (!s->we_are_in) {
8964 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
8966 * We got a username last time round this loop, and
8967 * with change_username turned off we don't try to get
8970 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
8971 int ret; /* need not be kept over crReturn */
8972 s->cur_prompt = new_prompts(ssh->frontend);
8973 s->cur_prompt->to_server = TRUE;
8974 s->cur_prompt->name = dupstr("SSH login name");
8975 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
8976 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8979 crWaitUntilV(!pktin);
8980 ret = get_userpass_input(s->cur_prompt, in, inlen);
8985 * get_userpass_input() failed to get a username.
8988 free_prompts(s->cur_prompt);
8989 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
8992 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
8993 free_prompts(s->cur_prompt);
8996 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
8997 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
8998 c_write_str(ssh, stuff);
9002 s->got_username = TRUE;
9005 * Send an authentication request using method "none": (a)
9006 * just in case it succeeds, and (b) so that we know what
9007 * authentication methods we can usefully try next.
9009 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9011 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9012 ssh2_pkt_addstring(s->pktout, ssh->username);
9013 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
9014 ssh2_pkt_addstring(s->pktout, "none"); /* method */
9015 ssh2_pkt_send(ssh, s->pktout);
9016 s->type = AUTH_TYPE_NONE;
9018 s->we_are_in = FALSE;
9020 s->tried_pubkey_config = FALSE;
9021 s->kbd_inter_refused = FALSE;
9023 /* Reset agent request state. */
9024 s->done_agent = FALSE;
9025 if (s->agent_response) {
9026 if (s->pkblob_in_agent) {
9027 s->agentp = s->pkblob_in_agent;
9029 s->agentp = s->agent_response + 5 + 4;
9035 char *methods = NULL;
9039 * Wait for the result of the last authentication request.
9042 crWaitUntilV(pktin);
9044 * Now is a convenient point to spew any banner material
9045 * that we've accumulated. (This should ensure that when
9046 * we exit the auth loop, we haven't any left to deal
9050 int size = bufchain_size(&ssh->banner);
9052 * Don't show the banner if we're operating in
9053 * non-verbose non-interactive mode. (It's probably
9054 * a script, which means nobody will read the
9055 * banner _anyway_, and moreover the printing of
9056 * the banner will screw up processing on the
9057 * output of (say) plink.)
9059 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
9060 char *banner = snewn(size, char);
9061 bufchain_fetch(&ssh->banner, banner, size);
9062 c_write_untrusted(ssh, banner, size);
9065 bufchain_clear(&ssh->banner);
9067 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
9068 logevent("Access granted");
9069 s->we_are_in = s->userauth_success = TRUE;
9073 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
9074 bombout(("Strange packet received during authentication: "
9075 "type %d", pktin->type));
9082 * OK, we're now sitting on a USERAUTH_FAILURE message, so
9083 * we can look at the string in it and know what we can
9084 * helpfully try next.
9086 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
9087 ssh_pkt_getstring(pktin, &methods, &methlen);
9088 if (!ssh2_pkt_getbool(pktin)) {
9090 * We have received an unequivocal Access
9091 * Denied. This can translate to a variety of
9092 * messages, or no message at all.
9094 * For forms of authentication which are attempted
9095 * implicitly, by which I mean without printing
9096 * anything in the window indicating that we're
9097 * trying them, we should never print 'Access
9100 * If we do print a message saying that we're
9101 * attempting some kind of authentication, it's OK
9102 * to print a followup message saying it failed -
9103 * but the message may sometimes be more specific
9104 * than simply 'Access denied'.
9106 * Additionally, if we'd just tried password
9107 * authentication, we should break out of this
9108 * whole loop so as to go back to the username
9109 * prompt (iff we're configured to allow
9110 * username change attempts).
9112 if (s->type == AUTH_TYPE_NONE) {
9114 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
9115 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
9116 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
9117 c_write_str(ssh, "Server refused our key\r\n");
9118 logevent("Server refused our key");
9119 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
9120 /* This _shouldn't_ happen except by a
9121 * protocol bug causing client and server to
9122 * disagree on what is a correct signature. */
9123 c_write_str(ssh, "Server refused public-key signature"
9124 " despite accepting key!\r\n");
9125 logevent("Server refused public-key signature"
9126 " despite accepting key!");
9127 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
9128 /* quiet, so no c_write */
9129 logevent("Server refused keyboard-interactive authentication");
9130 } else if (s->type==AUTH_TYPE_GSSAPI) {
9131 /* always quiet, so no c_write */
9132 /* also, the code down in the GSSAPI block has
9133 * already logged this in the Event Log */
9134 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
9135 logevent("Keyboard-interactive authentication failed");
9136 c_write_str(ssh, "Access denied\r\n");
9138 assert(s->type == AUTH_TYPE_PASSWORD);
9139 logevent("Password authentication failed");
9140 c_write_str(ssh, "Access denied\r\n");
9142 if (conf_get_int(ssh->conf, CONF_change_username)) {
9143 /* XXX perhaps we should allow
9144 * keyboard-interactive to do this too? */
9145 s->we_are_in = FALSE;
9150 c_write_str(ssh, "Further authentication required\r\n");
9151 logevent("Further authentication required");
9155 in_commasep_string("publickey", methods, methlen);
9157 in_commasep_string("password", methods, methlen);
9158 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
9159 in_commasep_string("keyboard-interactive", methods, methlen);
9161 if (conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
9162 in_commasep_string("gssapi-with-mic", methods, methlen)) {
9163 /* Try loading the GSS libraries and see if we
9166 ssh->gsslibs = ssh_gss_setup(ssh->conf);
9167 s->can_gssapi = (ssh->gsslibs->nlibraries > 0);
9169 /* No point in even bothering to try to load the
9170 * GSS libraries, if the user configuration and
9171 * server aren't both prepared to attempt GSSAPI
9172 * auth in the first place. */
9173 s->can_gssapi = FALSE;
9178 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9180 if (s->can_pubkey && !s->done_agent && s->nkeys) {
9183 * Attempt public-key authentication using a key from Pageant.
9186 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9188 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
9190 /* Unpack key from agent response */
9191 s->pklen = toint(GET_32BIT(s->agentp));
9193 s->pkblob = (char *)s->agentp;
9194 s->agentp += s->pklen;
9195 s->alglen = toint(GET_32BIT(s->pkblob));
9196 s->alg = s->pkblob + 4;
9197 s->commentlen = toint(GET_32BIT(s->agentp));
9199 s->commentp = (char *)s->agentp;
9200 s->agentp += s->commentlen;
9201 /* s->agentp now points at next key, if any */
9203 /* See if server will accept it */
9204 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9205 ssh2_pkt_addstring(s->pktout, ssh->username);
9206 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9207 /* service requested */
9208 ssh2_pkt_addstring(s->pktout, "publickey");
9210 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
9211 ssh2_pkt_addstring_start(s->pktout);
9212 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9213 ssh2_pkt_addstring_start(s->pktout);
9214 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9215 ssh2_pkt_send(ssh, s->pktout);
9216 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
9218 crWaitUntilV(pktin);
9219 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9221 /* Offer of key refused. */
9228 if (flags & FLAG_VERBOSE) {
9229 c_write_str(ssh, "Authenticating with "
9231 c_write(ssh, s->commentp, s->commentlen);
9232 c_write_str(ssh, "\" from agent\r\n");
9236 * Server is willing to accept the key.
9237 * Construct a SIGN_REQUEST.
9239 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9240 ssh2_pkt_addstring(s->pktout, ssh->username);
9241 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9242 /* service requested */
9243 ssh2_pkt_addstring(s->pktout, "publickey");
9245 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
9246 ssh2_pkt_addstring_start(s->pktout);
9247 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9248 ssh2_pkt_addstring_start(s->pktout);
9249 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9251 /* Ask agent for signature. */
9252 s->siglen = s->pktout->length - 5 + 4 +
9253 ssh->v2_session_id_len;
9254 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9256 s->len = 1; /* message type */
9257 s->len += 4 + s->pklen; /* key blob */
9258 s->len += 4 + s->siglen; /* data to sign */
9259 s->len += 4; /* flags */
9260 s->agentreq = snewn(4 + s->len, char);
9261 PUT_32BIT(s->agentreq, s->len);
9262 s->q = s->agentreq + 4;
9263 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
9264 PUT_32BIT(s->q, s->pklen);
9266 memcpy(s->q, s->pkblob, s->pklen);
9268 PUT_32BIT(s->q, s->siglen);
9270 /* Now the data to be signed... */
9271 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9272 PUT_32BIT(s->q, ssh->v2_session_id_len);
9275 memcpy(s->q, ssh->v2_session_id,
9276 ssh->v2_session_id_len);
9277 s->q += ssh->v2_session_id_len;
9278 memcpy(s->q, s->pktout->data + 5,
9279 s->pktout->length - 5);
9280 s->q += s->pktout->length - 5;
9281 /* And finally the (zero) flags word. */
9283 if (!agent_query(s->agentreq, s->len + 4,
9285 ssh_agent_callback, ssh)) {
9289 bombout(("Unexpected data from server"
9290 " while waiting for agent"
9294 } while (pktin || inlen > 0);
9295 vret = ssh->agent_response;
9296 s->retlen = ssh->agent_response_len;
9301 if (s->retlen >= 9 &&
9302 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
9303 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
9304 logevent("Sending Pageant's response");
9305 ssh2_add_sigblob(ssh, s->pktout,
9306 s->pkblob, s->pklen,
9308 GET_32BIT(s->ret + 5));
9309 ssh2_pkt_send(ssh, s->pktout);
9310 s->type = AUTH_TYPE_PUBLICKEY;
9312 /* FIXME: less drastic response */
9313 bombout(("Pageant failed to answer challenge"));
9319 /* Do we have any keys left to try? */
9320 if (s->pkblob_in_agent) {
9321 s->done_agent = TRUE;
9322 s->tried_pubkey_config = TRUE;
9325 if (s->keyi >= s->nkeys)
9326 s->done_agent = TRUE;
9329 } else if (s->can_pubkey && s->publickey_blob &&
9330 !s->tried_pubkey_config) {
9332 struct ssh2_userkey *key; /* not live over crReturn */
9333 char *passphrase; /* not live over crReturn */
9335 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9337 s->tried_pubkey_config = TRUE;
9340 * Try the public key supplied in the configuration.
9342 * First, offer the public blob to see if the server is
9343 * willing to accept it.
9345 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9346 ssh2_pkt_addstring(s->pktout, ssh->username);
9347 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9348 /* service requested */
9349 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
9350 ssh2_pkt_addbool(s->pktout, FALSE);
9351 /* no signature included */
9352 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
9353 ssh2_pkt_addstring_start(s->pktout);
9354 ssh2_pkt_addstring_data(s->pktout,
9355 (char *)s->publickey_blob,
9356 s->publickey_bloblen);
9357 ssh2_pkt_send(ssh, s->pktout);
9358 logevent("Offered public key");
9360 crWaitUntilV(pktin);
9361 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9362 /* Key refused. Give up. */
9363 s->gotit = TRUE; /* reconsider message next loop */
9364 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
9365 continue; /* process this new message */
9367 logevent("Offer of public key accepted");
9370 * Actually attempt a serious authentication using
9373 if (flags & FLAG_VERBOSE) {
9374 c_write_str(ssh, "Authenticating with public key \"");
9375 c_write_str(ssh, s->publickey_comment);
9376 c_write_str(ssh, "\"\r\n");
9380 const char *error; /* not live over crReturn */
9381 if (s->publickey_encrypted) {
9383 * Get a passphrase from the user.
9385 int ret; /* need not be kept over crReturn */
9386 s->cur_prompt = new_prompts(ssh->frontend);
9387 s->cur_prompt->to_server = FALSE;
9388 s->cur_prompt->name = dupstr("SSH key passphrase");
9389 add_prompt(s->cur_prompt,
9390 dupprintf("Passphrase for key \"%.100s\": ",
9391 s->publickey_comment),
9393 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9396 crWaitUntilV(!pktin);
9397 ret = get_userpass_input(s->cur_prompt,
9402 /* Failed to get a passphrase. Terminate. */
9403 free_prompts(s->cur_prompt);
9404 ssh_disconnect(ssh, NULL,
9405 "Unable to authenticate",
9406 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9411 dupstr(s->cur_prompt->prompts[0]->result);
9412 free_prompts(s->cur_prompt);
9414 passphrase = NULL; /* no passphrase needed */
9418 * Try decrypting the key.
9420 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9421 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
9423 /* burn the evidence */
9424 smemclr(passphrase, strlen(passphrase));
9427 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
9429 (key == SSH2_WRONG_PASSPHRASE)) {
9430 c_write_str(ssh, "Wrong passphrase\r\n");
9432 /* and loop again */
9434 c_write_str(ssh, "Unable to load private key (");
9435 c_write_str(ssh, error);
9436 c_write_str(ssh, ")\r\n");
9438 break; /* try something else */
9444 unsigned char *pkblob, *sigblob, *sigdata;
9445 int pkblob_len, sigblob_len, sigdata_len;
9449 * We have loaded the private key and the server
9450 * has announced that it's willing to accept it.
9451 * Hallelujah. Generate a signature and send it.
9453 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9454 ssh2_pkt_addstring(s->pktout, ssh->username);
9455 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9456 /* service requested */
9457 ssh2_pkt_addstring(s->pktout, "publickey");
9459 ssh2_pkt_addbool(s->pktout, TRUE);
9460 /* signature follows */
9461 ssh2_pkt_addstring(s->pktout, key->alg->name);
9462 pkblob = key->alg->public_blob(key->data,
9464 ssh2_pkt_addstring_start(s->pktout);
9465 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
9469 * The data to be signed is:
9473 * followed by everything so far placed in the
9476 sigdata_len = s->pktout->length - 5 + 4 +
9477 ssh->v2_session_id_len;
9478 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9480 sigdata = snewn(sigdata_len, unsigned char);
9482 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9483 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
9486 memcpy(sigdata+p, ssh->v2_session_id,
9487 ssh->v2_session_id_len);
9488 p += ssh->v2_session_id_len;
9489 memcpy(sigdata+p, s->pktout->data + 5,
9490 s->pktout->length - 5);
9491 p += s->pktout->length - 5;
9492 assert(p == sigdata_len);
9493 sigblob = key->alg->sign(key->data, (char *)sigdata,
9494 sigdata_len, &sigblob_len);
9495 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
9496 sigblob, sigblob_len);
9501 ssh2_pkt_send(ssh, s->pktout);
9502 logevent("Sent public key signature");
9503 s->type = AUTH_TYPE_PUBLICKEY;
9504 key->alg->freekey(key->data);
9505 sfree(key->comment);
9510 } else if (s->can_gssapi && !s->tried_gssapi) {
9512 /* GSSAPI Authentication */
9517 s->type = AUTH_TYPE_GSSAPI;
9518 s->tried_gssapi = TRUE;
9520 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
9523 * Pick the highest GSS library on the preference
9529 for (i = 0; i < ngsslibs; i++) {
9530 int want_id = conf_get_int_int(ssh->conf,
9531 CONF_ssh_gsslist, i);
9532 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
9533 if (ssh->gsslibs->libraries[j].id == want_id) {
9534 s->gsslib = &ssh->gsslibs->libraries[j];
9535 goto got_gsslib; /* double break */
9540 * We always expect to have found something in
9541 * the above loop: we only came here if there
9542 * was at least one viable GSS library, and the
9543 * preference list should always mention
9544 * everything and only change the order.
9549 if (s->gsslib->gsslogmsg)
9550 logevent(s->gsslib->gsslogmsg);
9552 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
9553 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9554 ssh2_pkt_addstring(s->pktout, ssh->username);
9555 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9556 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
9557 logevent("Attempting GSSAPI authentication");
9559 /* add mechanism info */
9560 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
9562 /* number of GSSAPI mechanisms */
9563 ssh2_pkt_adduint32(s->pktout,1);
9565 /* length of OID + 2 */
9566 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
9567 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
9570 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
9572 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
9574 ssh2_pkt_send(ssh, s->pktout);
9575 crWaitUntilV(pktin);
9576 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
9577 logevent("GSSAPI authentication request refused");
9581 /* check returned packet ... */
9583 ssh_pkt_getstring(pktin, &data, &len);
9584 s->gss_rcvtok.value = data;
9585 s->gss_rcvtok.length = len;
9586 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
9587 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
9588 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
9589 memcmp((char *)s->gss_rcvtok.value + 2,
9590 s->gss_buf.value,s->gss_buf.length) ) {
9591 logevent("GSSAPI authentication - wrong response from server");
9595 /* now start running */
9596 s->gss_stat = s->gsslib->import_name(s->gsslib,
9599 if (s->gss_stat != SSH_GSS_OK) {
9600 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
9601 logevent("GSSAPI import name failed - Bad service name");
9603 logevent("GSSAPI import name failed");
9607 /* fetch TGT into GSS engine */
9608 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
9610 if (s->gss_stat != SSH_GSS_OK) {
9611 logevent("GSSAPI authentication failed to get credentials");
9612 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9616 /* initial tokens are empty */
9617 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
9618 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
9620 /* now enter the loop */
9622 s->gss_stat = s->gsslib->init_sec_context
9626 conf_get_int(ssh->conf, CONF_gssapifwd),
9630 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
9631 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
9632 logevent("GSSAPI authentication initialisation failed");
9634 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
9635 &s->gss_buf) == SSH_GSS_OK) {
9636 logevent(s->gss_buf.value);
9637 sfree(s->gss_buf.value);
9642 logevent("GSSAPI authentication initialised");
9644 /* Client and server now exchange tokens until GSSAPI
9645 * no longer says CONTINUE_NEEDED */
9647 if (s->gss_sndtok.length != 0) {
9648 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
9649 ssh_pkt_addstring_start(s->pktout);
9650 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
9651 ssh2_pkt_send(ssh, s->pktout);
9652 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
9655 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
9656 crWaitUntilV(pktin);
9657 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
9658 logevent("GSSAPI authentication - bad server response");
9659 s->gss_stat = SSH_GSS_FAILURE;
9662 ssh_pkt_getstring(pktin, &data, &len);
9663 s->gss_rcvtok.value = data;
9664 s->gss_rcvtok.length = len;
9666 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
9668 if (s->gss_stat != SSH_GSS_OK) {
9669 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9670 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9673 logevent("GSSAPI authentication loop finished OK");
9675 /* Now send the MIC */
9677 s->pktout = ssh2_pkt_init(0);
9678 micoffset = s->pktout->length;
9679 ssh_pkt_addstring_start(s->pktout);
9680 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
9681 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
9682 ssh_pkt_addstring(s->pktout, ssh->username);
9683 ssh_pkt_addstring(s->pktout, "ssh-connection");
9684 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
9686 s->gss_buf.value = (char *)s->pktout->data + micoffset;
9687 s->gss_buf.length = s->pktout->length - micoffset;
9689 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
9690 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
9691 ssh_pkt_addstring_start(s->pktout);
9692 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
9693 ssh2_pkt_send(ssh, s->pktout);
9694 s->gsslib->free_mic(s->gsslib, &mic);
9698 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9699 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9702 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
9705 * Keyboard-interactive authentication.
9708 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
9710 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
9712 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9713 ssh2_pkt_addstring(s->pktout, ssh->username);
9714 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9715 /* service requested */
9716 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
9718 ssh2_pkt_addstring(s->pktout, ""); /* lang */
9719 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
9720 ssh2_pkt_send(ssh, s->pktout);
9722 logevent("Attempting keyboard-interactive authentication");
9724 crWaitUntilV(pktin);
9725 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
9726 /* Server is not willing to do keyboard-interactive
9727 * at all (or, bizarrely but legally, accepts the
9728 * user without actually issuing any prompts).
9729 * Give up on it entirely. */
9731 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
9732 s->kbd_inter_refused = TRUE; /* don't try it again */
9737 * Loop while the server continues to send INFO_REQUESTs.
9739 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
9741 char *name, *inst, *lang;
9742 int name_len, inst_len, lang_len;
9746 * We've got a fresh USERAUTH_INFO_REQUEST.
9747 * Get the preamble and start building a prompt.
9749 ssh_pkt_getstring(pktin, &name, &name_len);
9750 ssh_pkt_getstring(pktin, &inst, &inst_len);
9751 ssh_pkt_getstring(pktin, &lang, &lang_len);
9752 s->cur_prompt = new_prompts(ssh->frontend);
9753 s->cur_prompt->to_server = TRUE;
9756 * Get any prompt(s) from the packet.
9758 s->num_prompts = ssh_pkt_getuint32(pktin);
9759 for (i = 0; i < s->num_prompts; i++) {
9763 static char noprompt[] =
9764 "<server failed to send prompt>: ";
9766 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9767 echo = ssh2_pkt_getbool(pktin);
9770 prompt_len = lenof(noprompt)-1;
9772 add_prompt(s->cur_prompt,
9773 dupprintf("%.*s", prompt_len, prompt),
9778 /* FIXME: better prefix to distinguish from
9780 s->cur_prompt->name =
9781 dupprintf("SSH server: %.*s", name_len, name);
9782 s->cur_prompt->name_reqd = TRUE;
9784 s->cur_prompt->name =
9785 dupstr("SSH server authentication");
9786 s->cur_prompt->name_reqd = FALSE;
9788 /* We add a prefix to try to make it clear that a prompt
9789 * has come from the server.
9790 * FIXME: ugly to print "Using..." in prompt _every_
9791 * time round. Can this be done more subtly? */
9792 /* Special case: for reasons best known to themselves,
9793 * some servers send k-i requests with no prompts and
9794 * nothing to display. Keep quiet in this case. */
9795 if (s->num_prompts || name_len || inst_len) {
9796 s->cur_prompt->instruction =
9797 dupprintf("Using keyboard-interactive authentication.%s%.*s",
9798 inst_len ? "\n" : "", inst_len, inst);
9799 s->cur_prompt->instr_reqd = TRUE;
9801 s->cur_prompt->instr_reqd = FALSE;
9805 * Display any instructions, and get the user's
9809 int ret; /* not live over crReturn */
9810 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9813 crWaitUntilV(!pktin);
9814 ret = get_userpass_input(s->cur_prompt, in, inlen);
9819 * Failed to get responses. Terminate.
9821 free_prompts(s->cur_prompt);
9822 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9823 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9830 * Send the response(s) to the server.
9832 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
9833 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
9834 for (i=0; i < s->num_prompts; i++) {
9835 ssh2_pkt_addstring(s->pktout,
9836 s->cur_prompt->prompts[i]->result);
9838 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9841 * Free the prompts structure from this iteration.
9842 * If there's another, a new one will be allocated
9843 * when we return to the top of this while loop.
9845 free_prompts(s->cur_prompt);
9848 * Get the next packet in case it's another
9851 crWaitUntilV(pktin);
9856 * We should have SUCCESS or FAILURE now.
9860 } else if (s->can_passwd) {
9863 * Plain old password authentication.
9865 int ret; /* not live over crReturn */
9866 int changereq_first_time; /* not live over crReturn */
9868 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
9870 s->cur_prompt = new_prompts(ssh->frontend);
9871 s->cur_prompt->to_server = TRUE;
9872 s->cur_prompt->name = dupstr("SSH password");
9873 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
9878 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9881 crWaitUntilV(!pktin);
9882 ret = get_userpass_input(s->cur_prompt, in, inlen);
9887 * Failed to get responses. Terminate.
9889 free_prompts(s->cur_prompt);
9890 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9891 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9896 * Squirrel away the password. (We may need it later if
9897 * asked to change it.)
9899 s->password = dupstr(s->cur_prompt->prompts[0]->result);
9900 free_prompts(s->cur_prompt);
9903 * Send the password packet.
9905 * We pad out the password packet to 256 bytes to make
9906 * it harder for an attacker to find the length of the
9909 * Anyone using a password longer than 256 bytes
9910 * probably doesn't have much to worry about from
9911 * people who find out how long their password is!
9913 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9914 ssh2_pkt_addstring(s->pktout, ssh->username);
9915 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9916 /* service requested */
9917 ssh2_pkt_addstring(s->pktout, "password");
9918 ssh2_pkt_addbool(s->pktout, FALSE);
9919 ssh2_pkt_addstring(s->pktout, s->password);
9920 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9921 logevent("Sent password");
9922 s->type = AUTH_TYPE_PASSWORD;
9925 * Wait for next packet, in case it's a password change
9928 crWaitUntilV(pktin);
9929 changereq_first_time = TRUE;
9931 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
9934 * We're being asked for a new password
9935 * (perhaps not for the first time).
9936 * Loop until the server accepts it.
9939 int got_new = FALSE; /* not live over crReturn */
9940 char *prompt; /* not live over crReturn */
9941 int prompt_len; /* not live over crReturn */
9945 if (changereq_first_time)
9946 msg = "Server requested password change";
9948 msg = "Server rejected new password";
9950 c_write_str(ssh, msg);
9951 c_write_str(ssh, "\r\n");
9954 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9956 s->cur_prompt = new_prompts(ssh->frontend);
9957 s->cur_prompt->to_server = TRUE;
9958 s->cur_prompt->name = dupstr("New SSH password");
9959 s->cur_prompt->instruction =
9960 dupprintf("%.*s", prompt_len, prompt);
9961 s->cur_prompt->instr_reqd = TRUE;
9963 * There's no explicit requirement in the protocol
9964 * for the "old" passwords in the original and
9965 * password-change messages to be the same, and
9966 * apparently some Cisco kit supports password change
9967 * by the user entering a blank password originally
9968 * and the real password subsequently, so,
9969 * reluctantly, we prompt for the old password again.
9971 * (On the other hand, some servers don't even bother
9972 * to check this field.)
9974 add_prompt(s->cur_prompt,
9975 dupstr("Current password (blank for previously entered password): "),
9977 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
9979 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
9983 * Loop until the user manages to enter the same
9988 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9991 crWaitUntilV(!pktin);
9992 ret = get_userpass_input(s->cur_prompt, in, inlen);
9997 * Failed to get responses. Terminate.
9999 /* burn the evidence */
10000 free_prompts(s->cur_prompt);
10001 smemclr(s->password, strlen(s->password));
10002 sfree(s->password);
10003 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10004 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10010 * If the user specified a new original password
10011 * (IYSWIM), overwrite any previously specified
10013 * (A side effect is that the user doesn't have to
10014 * re-enter it if they louse up the new password.)
10016 if (s->cur_prompt->prompts[0]->result[0]) {
10017 smemclr(s->password, strlen(s->password));
10018 /* burn the evidence */
10019 sfree(s->password);
10021 dupstr(s->cur_prompt->prompts[0]->result);
10025 * Check the two new passwords match.
10027 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
10028 s->cur_prompt->prompts[2]->result)
10031 /* They don't. Silly user. */
10032 c_write_str(ssh, "Passwords do not match\r\n");
10037 * Send the new password (along with the old one).
10038 * (see above for padding rationale)
10040 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10041 ssh2_pkt_addstring(s->pktout, ssh->username);
10042 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10043 /* service requested */
10044 ssh2_pkt_addstring(s->pktout, "password");
10045 ssh2_pkt_addbool(s->pktout, TRUE);
10046 ssh2_pkt_addstring(s->pktout, s->password);
10047 ssh2_pkt_addstring(s->pktout,
10048 s->cur_prompt->prompts[1]->result);
10049 free_prompts(s->cur_prompt);
10050 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10051 logevent("Sent new password");
10054 * Now see what the server has to say about it.
10055 * (If it's CHANGEREQ again, it's not happy with the
10058 crWaitUntilV(pktin);
10059 changereq_first_time = FALSE;
10064 * We need to reexamine the current pktin at the top
10065 * of the loop. Either:
10066 * - we weren't asked to change password at all, in
10067 * which case it's a SUCCESS or FAILURE with the
10069 * - we sent a new password, and the server was
10070 * either OK with it (SUCCESS or FAILURE w/partial
10071 * success) or unhappy with the _old_ password
10072 * (FAILURE w/o partial success)
10073 * In any of these cases, we go back to the top of
10074 * the loop and start again.
10079 * We don't need the old password any more, in any
10080 * case. Burn the evidence.
10082 smemclr(s->password, strlen(s->password));
10083 sfree(s->password);
10086 char *str = dupprintf("No supported authentication methods available"
10087 " (server sent: %.*s)",
10090 ssh_disconnect(ssh, str,
10091 "No supported authentication methods available",
10092 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
10102 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
10104 /* Clear up various bits and pieces from authentication. */
10105 if (s->publickey_blob) {
10106 sfree(s->publickey_blob);
10107 sfree(s->publickey_comment);
10109 if (s->agent_response)
10110 sfree(s->agent_response);
10112 if (s->userauth_success && !ssh->bare_connection) {
10114 * We've just received USERAUTH_SUCCESS, and we haven't sent any
10115 * packets since. Signal the transport layer to consider enacting
10116 * delayed compression.
10118 * (Relying on we_are_in is not sufficient, as
10119 * draft-miller-secsh-compression-delayed is quite clear that it
10120 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
10121 * become set for other reasons.)
10123 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
10126 ssh->channels = newtree234(ssh_channelcmp);
10129 * Set up handlers for some connection protocol messages, so we
10130 * don't have to handle them repeatedly in this coroutine.
10132 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
10133 ssh2_msg_channel_window_adjust;
10134 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
10135 ssh2_msg_global_request;
10138 * Create the main session channel.
10140 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
10141 ssh->mainchan = NULL;
10143 ssh->mainchan = snew(struct ssh_channel);
10144 ssh->mainchan->ssh = ssh;
10145 ssh2_channel_init(ssh->mainchan);
10147 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
10149 * Just start a direct-tcpip channel and use it as the main
10152 ssh_send_port_open(ssh->mainchan,
10153 conf_get_str(ssh->conf, CONF_ssh_nc_host),
10154 conf_get_int(ssh->conf, CONF_ssh_nc_port),
10156 ssh->ncmode = TRUE;
10158 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
10159 logevent("Opening session as main channel");
10160 ssh2_pkt_send(ssh, s->pktout);
10161 ssh->ncmode = FALSE;
10163 crWaitUntilV(pktin);
10164 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
10165 bombout(("Server refused to open channel"));
10167 /* FIXME: error data comes back in FAILURE packet */
10169 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
10170 bombout(("Server's channel confirmation cited wrong channel"));
10173 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
10174 ssh->mainchan->halfopen = FALSE;
10175 ssh->mainchan->type = CHAN_MAINSESSION;
10176 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
10177 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
10178 add234(ssh->channels, ssh->mainchan);
10179 update_specials_menu(ssh->frontend);
10180 logevent("Opened main channel");
10184 * Now we have a channel, make dispatch table entries for
10185 * general channel-based messages.
10187 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
10188 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
10189 ssh2_msg_channel_data;
10190 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
10191 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
10192 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
10193 ssh2_msg_channel_open_confirmation;
10194 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
10195 ssh2_msg_channel_open_failure;
10196 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
10197 ssh2_msg_channel_request;
10198 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
10199 ssh2_msg_channel_open;
10200 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
10201 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
10204 * Now the connection protocol is properly up and running, with
10205 * all those dispatch table entries, so it's safe to let
10206 * downstreams start trying to open extra channels through us.
10208 if (ssh->connshare)
10209 share_activate(ssh->connshare, ssh->v_s);
10211 if (ssh->mainchan && ssh_is_simple(ssh)) {
10213 * This message indicates to the server that we promise
10214 * not to try to run any other channel in parallel with
10215 * this one, so it's safe for it to advertise a very large
10216 * window and leave the flow control to TCP.
10218 s->pktout = ssh2_chanreq_init(ssh->mainchan,
10219 "simple@putty.projects.tartarus.org",
10221 ssh2_pkt_send(ssh, s->pktout);
10225 * Enable port forwardings.
10227 ssh_setup_portfwd(ssh, ssh->conf);
10229 if (ssh->mainchan && !ssh->ncmode) {
10231 * Send the CHANNEL_REQUESTS for the main session channel.
10232 * Each one is handled by its own little asynchronous
10236 /* Potentially enable X11 forwarding. */
10237 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
10239 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
10241 if (!ssh->x11disp) {
10242 /* FIXME: return an error message from x11_setup_display */
10243 logevent("X11 forwarding not enabled: unable to"
10244 " initialise X display");
10246 ssh->x11auth = x11_invent_fake_auth
10247 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
10248 ssh->x11auth->disp = ssh->x11disp;
10250 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
10254 /* Potentially enable agent forwarding. */
10255 if (ssh_agent_forwarding_permitted(ssh))
10256 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
10258 /* Now allocate a pty for the session. */
10259 if (!conf_get_int(ssh->conf, CONF_nopty))
10260 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
10262 /* Send environment variables. */
10263 ssh2_setup_env(ssh->mainchan, NULL, NULL);
10266 * Start a shell or a remote command. We may have to attempt
10267 * this twice if the config data has provided a second choice
10274 if (ssh->fallback_cmd) {
10275 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
10276 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
10278 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
10279 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
10283 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
10284 ssh2_response_authconn, NULL);
10285 ssh2_pkt_addstring(s->pktout, cmd);
10287 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
10288 ssh2_response_authconn, NULL);
10289 ssh2_pkt_addstring(s->pktout, cmd);
10291 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
10292 ssh2_response_authconn, NULL);
10294 ssh2_pkt_send(ssh, s->pktout);
10296 crWaitUntilV(pktin);
10298 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
10299 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
10300 bombout(("Unexpected response to shell/command request:"
10301 " packet type %d", pktin->type));
10305 * We failed to start the command. If this is the
10306 * fallback command, we really are finished; if it's
10307 * not, and if the fallback command exists, try falling
10308 * back to it before complaining.
10310 if (!ssh->fallback_cmd &&
10311 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
10312 logevent("Primary command failed; attempting fallback");
10313 ssh->fallback_cmd = TRUE;
10316 bombout(("Server refused to start a shell/command"));
10319 logevent("Started a shell/command");
10324 ssh->editing = ssh->echoing = TRUE;
10327 ssh->state = SSH_STATE_SESSION;
10328 if (ssh->size_needed)
10329 ssh_size(ssh, ssh->term_width, ssh->term_height);
10330 if (ssh->eof_needed)
10331 ssh_special(ssh, TS_EOF);
10337 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
10342 s->try_send = FALSE;
10346 * _All_ the connection-layer packets we expect to
10347 * receive are now handled by the dispatch table.
10348 * Anything that reaches here must be bogus.
10351 bombout(("Strange packet received: type %d", pktin->type));
10353 } else if (ssh->mainchan) {
10355 * We have spare data. Add it to the channel buffer.
10357 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
10358 s->try_send = TRUE;
10362 struct ssh_channel *c;
10364 * Try to send data on all channels if we can.
10366 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
10367 if (c->type != CHAN_SHARING)
10368 ssh2_try_send_and_unthrottle(ssh, c);
10376 * Handlers for SSH-2 messages that might arrive at any moment.
10378 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
10380 /* log reason code in disconnect message */
10382 int reason, msglen;
10384 reason = ssh_pkt_getuint32(pktin);
10385 ssh_pkt_getstring(pktin, &msg, &msglen);
10387 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
10388 buf = dupprintf("Received disconnect message (%s)",
10389 ssh2_disconnect_reasons[reason]);
10391 buf = dupprintf("Received disconnect message (unknown"
10392 " type %d)", reason);
10396 buf = dupprintf("Disconnection message text: %.*s",
10399 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
10401 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
10402 ssh2_disconnect_reasons[reason] : "unknown",
10407 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
10409 /* log the debug message */
10413 /* XXX maybe we should actually take notice of the return value */
10414 ssh2_pkt_getbool(pktin);
10415 ssh_pkt_getstring(pktin, &msg, &msglen);
10417 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
10420 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
10422 do_ssh2_transport(ssh, NULL, 0, pktin);
10426 * Called if we receive a packet that isn't allowed by the protocol.
10427 * This only applies to packets whose meaning PuTTY understands.
10428 * Entirely unknown packets are handled below.
10430 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
10432 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
10433 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
10435 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
10439 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
10441 struct Packet *pktout;
10442 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
10443 ssh2_pkt_adduint32(pktout, pktin->sequence);
10445 * UNIMPLEMENTED messages MUST appear in the same order as the
10446 * messages they respond to. Hence, never queue them.
10448 ssh2_pkt_send_noqueue(ssh, pktout);
10452 * Handle the top-level SSH-2 protocol.
10454 static void ssh2_protocol_setup(Ssh ssh)
10459 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10461 for (i = 0; i < 256; i++)
10462 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10465 * Initially, we only accept transport messages (and a few generic
10466 * ones). do_ssh2_authconn will add more when it starts.
10467 * Messages that are understood but not currently acceptable go to
10468 * ssh2_msg_unexpected.
10470 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10471 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
10472 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
10473 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
10474 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
10475 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
10476 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
10477 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
10478 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
10479 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
10480 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
10481 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
10482 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
10483 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
10484 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
10485 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
10486 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
10487 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
10488 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
10489 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10490 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10491 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10492 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10493 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10494 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10495 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10496 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10497 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10498 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10499 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10500 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10501 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10502 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10505 * These messages have a special handler from the start.
10507 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10508 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
10509 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10512 static void ssh2_bare_connection_protocol_setup(Ssh ssh)
10517 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10519 for (i = 0; i < 256; i++)
10520 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10523 * Initially, we set all ssh-connection messages to 'unexpected';
10524 * do_ssh2_authconn will fill things in properly. We also handle a
10525 * couple of messages from the transport protocol which aren't
10526 * related to key exchange (UNIMPLEMENTED, IGNORE, DEBUG,
10529 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10530 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10531 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10532 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10533 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10534 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10535 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10536 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10537 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10538 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10539 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10540 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10541 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10542 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10544 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10547 * These messages have a special handler from the start.
10549 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10550 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore;
10551 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10554 static void ssh2_timer(void *ctx, unsigned long now)
10556 Ssh ssh = (Ssh)ctx;
10558 if (ssh->state == SSH_STATE_CLOSED)
10561 if (!ssh->kex_in_progress && !ssh->bare_connection &&
10562 conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
10563 now == ssh->next_rekey) {
10564 do_ssh2_transport(ssh, "timeout", -1, NULL);
10568 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
10569 struct Packet *pktin)
10571 unsigned char *in = (unsigned char *)vin;
10572 if (ssh->state == SSH_STATE_CLOSED)
10576 ssh->incoming_data_size += pktin->encrypted_len;
10577 if (!ssh->kex_in_progress &&
10578 ssh->max_data_size != 0 &&
10579 ssh->incoming_data_size > ssh->max_data_size)
10580 do_ssh2_transport(ssh, "too much data received", -1, NULL);
10584 ssh->packet_dispatch[pktin->type](ssh, pktin);
10585 else if (!ssh->protocol_initial_phase_done)
10586 do_ssh2_transport(ssh, in, inlen, pktin);
10588 do_ssh2_authconn(ssh, in, inlen, pktin);
10591 static void ssh2_bare_connection_protocol(Ssh ssh, void *vin, int inlen,
10592 struct Packet *pktin)
10594 unsigned char *in = (unsigned char *)vin;
10595 if (ssh->state == SSH_STATE_CLOSED)
10599 ssh->packet_dispatch[pktin->type](ssh, pktin);
10601 do_ssh2_authconn(ssh, in, inlen, pktin);
10604 static void ssh_cache_conf_values(Ssh ssh)
10606 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
10610 * Called to set up the connection.
10612 * Returns an error message, or NULL on success.
10614 static const char *ssh_init(void *frontend_handle, void **backend_handle,
10615 Conf *conf, char *host, int port, char **realhost,
10616 int nodelay, int keepalive)
10621 ssh = snew(struct ssh_tag);
10622 ssh->conf = conf_copy(conf);
10623 ssh_cache_conf_values(ssh);
10624 ssh->version = 0; /* when not ready yet */
10626 ssh->cipher = NULL;
10627 ssh->v1_cipher_ctx = NULL;
10628 ssh->crcda_ctx = NULL;
10629 ssh->cscipher = NULL;
10630 ssh->cs_cipher_ctx = NULL;
10631 ssh->sccipher = NULL;
10632 ssh->sc_cipher_ctx = NULL;
10634 ssh->cs_mac_ctx = NULL;
10636 ssh->sc_mac_ctx = NULL;
10637 ssh->cscomp = NULL;
10638 ssh->cs_comp_ctx = NULL;
10639 ssh->sccomp = NULL;
10640 ssh->sc_comp_ctx = NULL;
10642 ssh->kex_ctx = NULL;
10643 ssh->hostkey = NULL;
10644 ssh->hostkey_str = NULL;
10645 ssh->exitcode = -1;
10646 ssh->close_expected = FALSE;
10647 ssh->clean_exit = FALSE;
10648 ssh->state = SSH_STATE_PREPACKET;
10649 ssh->size_needed = FALSE;
10650 ssh->eof_needed = FALSE;
10652 ssh->logctx = NULL;
10653 ssh->deferred_send_data = NULL;
10654 ssh->deferred_len = 0;
10655 ssh->deferred_size = 0;
10656 ssh->fallback_cmd = 0;
10657 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
10658 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
10659 ssh->x11disp = NULL;
10660 ssh->x11auth = NULL;
10661 ssh->x11authtree = newtree234(x11_authcmp);
10662 ssh->v1_compressing = FALSE;
10663 ssh->v2_outgoing_sequence = 0;
10664 ssh->ssh1_rdpkt_crstate = 0;
10665 ssh->ssh2_rdpkt_crstate = 0;
10666 ssh->ssh2_bare_rdpkt_crstate = 0;
10667 ssh->ssh_gotdata_crstate = 0;
10668 ssh->do_ssh1_connection_crstate = 0;
10669 ssh->do_ssh_init_state = NULL;
10670 ssh->do_ssh_connection_init_state = NULL;
10671 ssh->do_ssh1_login_state = NULL;
10672 ssh->do_ssh2_transport_state = NULL;
10673 ssh->do_ssh2_authconn_state = NULL;
10676 ssh->mainchan = NULL;
10677 ssh->throttled_all = 0;
10678 ssh->v1_stdout_throttling = 0;
10680 ssh->queuelen = ssh->queuesize = 0;
10681 ssh->queueing = FALSE;
10682 ssh->qhead = ssh->qtail = NULL;
10683 ssh->deferred_rekey_reason = NULL;
10684 bufchain_init(&ssh->queued_incoming_data);
10685 ssh->frozen = FALSE;
10686 ssh->username = NULL;
10687 ssh->sent_console_eof = FALSE;
10688 ssh->got_pty = FALSE;
10689 ssh->bare_connection = FALSE;
10690 ssh->X11_fwd_enabled = FALSE;
10691 ssh->connshare = NULL;
10692 ssh->attempting_connshare = FALSE;
10694 *backend_handle = ssh;
10697 if (crypto_startup() == 0)
10698 return "Microsoft high encryption pack not installed!";
10701 ssh->frontend = frontend_handle;
10702 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
10703 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
10705 ssh->channels = NULL;
10706 ssh->rportfwds = NULL;
10707 ssh->portfwds = NULL;
10712 ssh->conn_throttle_count = 0;
10713 ssh->overall_bufsize = 0;
10714 ssh->fallback_cmd = 0;
10716 ssh->protocol = NULL;
10718 ssh->protocol_initial_phase_done = FALSE;
10720 ssh->pinger = NULL;
10722 ssh->incoming_data_size = ssh->outgoing_data_size =
10723 ssh->deferred_data_size = 0L;
10724 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10725 CONF_ssh_rekey_data));
10726 ssh->kex_in_progress = FALSE;
10729 ssh->gsslibs = NULL;
10732 random_ref(); /* do this now - may be needed by sharing setup code */
10734 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
10743 static void ssh_free(void *handle)
10745 Ssh ssh = (Ssh) handle;
10746 struct ssh_channel *c;
10747 struct ssh_rportfwd *pf;
10748 struct X11FakeAuth *auth;
10750 if (ssh->v1_cipher_ctx)
10751 ssh->cipher->free_context(ssh->v1_cipher_ctx);
10752 if (ssh->cs_cipher_ctx)
10753 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
10754 if (ssh->sc_cipher_ctx)
10755 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
10756 if (ssh->cs_mac_ctx)
10757 ssh->csmac->free_context(ssh->cs_mac_ctx);
10758 if (ssh->sc_mac_ctx)
10759 ssh->scmac->free_context(ssh->sc_mac_ctx);
10760 if (ssh->cs_comp_ctx) {
10762 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
10764 zlib_compress_cleanup(ssh->cs_comp_ctx);
10766 if (ssh->sc_comp_ctx) {
10768 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
10770 zlib_decompress_cleanup(ssh->sc_comp_ctx);
10773 dh_cleanup(ssh->kex_ctx);
10774 sfree(ssh->savedhost);
10776 while (ssh->queuelen-- > 0)
10777 ssh_free_packet(ssh->queue[ssh->queuelen]);
10780 while (ssh->qhead) {
10781 struct queued_handler *qh = ssh->qhead;
10782 ssh->qhead = qh->next;
10785 ssh->qhead = ssh->qtail = NULL;
10787 if (ssh->channels) {
10788 while ((c = delpos234(ssh->channels, 0)) != NULL) {
10791 if (c->u.x11.xconn != NULL)
10792 x11_close(c->u.x11.xconn);
10794 case CHAN_SOCKDATA:
10795 case CHAN_SOCKDATA_DORMANT:
10796 if (c->u.pfd.pf != NULL)
10797 pfd_close(c->u.pfd.pf);
10800 if (ssh->version == 2) {
10801 struct outstanding_channel_request *ocr, *nocr;
10802 ocr = c->v.v2.chanreq_head;
10804 ocr->handler(c, NULL, ocr->ctx);
10809 bufchain_clear(&c->v.v2.outbuffer);
10813 freetree234(ssh->channels);
10814 ssh->channels = NULL;
10817 if (ssh->connshare)
10818 sharestate_free(ssh->connshare);
10820 if (ssh->rportfwds) {
10821 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
10823 freetree234(ssh->rportfwds);
10824 ssh->rportfwds = NULL;
10826 sfree(ssh->deferred_send_data);
10828 x11_free_display(ssh->x11disp);
10829 while ((auth = delpos234(ssh->x11authtree, 0)) != NULL)
10830 x11_free_fake_auth(auth);
10831 freetree234(ssh->x11authtree);
10832 sfree(ssh->do_ssh_init_state);
10833 sfree(ssh->do_ssh1_login_state);
10834 sfree(ssh->do_ssh2_transport_state);
10835 sfree(ssh->do_ssh2_authconn_state);
10838 sfree(ssh->fullhostname);
10839 sfree(ssh->hostkey_str);
10840 if (ssh->crcda_ctx) {
10841 crcda_free_context(ssh->crcda_ctx);
10842 ssh->crcda_ctx = NULL;
10845 ssh_do_close(ssh, TRUE);
10846 expire_timer_context(ssh);
10848 pinger_free(ssh->pinger);
10849 bufchain_clear(&ssh->queued_incoming_data);
10850 sfree(ssh->username);
10851 conf_free(ssh->conf);
10854 ssh_gss_cleanup(ssh->gsslibs);
10862 * Reconfigure the SSH backend.
10864 static void ssh_reconfig(void *handle, Conf *conf)
10866 Ssh ssh = (Ssh) handle;
10867 char *rekeying = NULL, rekey_mandatory = FALSE;
10868 unsigned long old_max_data_size;
10871 pinger_reconfig(ssh->pinger, ssh->conf, conf);
10873 ssh_setup_portfwd(ssh, conf);
10875 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
10876 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
10878 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
10879 unsigned long now = GETTICKCOUNT();
10881 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
10882 rekeying = "timeout shortened";
10884 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
10888 old_max_data_size = ssh->max_data_size;
10889 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10890 CONF_ssh_rekey_data));
10891 if (old_max_data_size != ssh->max_data_size &&
10892 ssh->max_data_size != 0) {
10893 if (ssh->outgoing_data_size > ssh->max_data_size ||
10894 ssh->incoming_data_size > ssh->max_data_size)
10895 rekeying = "data limit lowered";
10898 if (conf_get_int(ssh->conf, CONF_compression) !=
10899 conf_get_int(conf, CONF_compression)) {
10900 rekeying = "compression setting changed";
10901 rekey_mandatory = TRUE;
10904 for (i = 0; i < CIPHER_MAX; i++)
10905 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
10906 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
10907 rekeying = "cipher settings changed";
10908 rekey_mandatory = TRUE;
10910 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
10911 conf_get_int(conf, CONF_ssh2_des_cbc)) {
10912 rekeying = "cipher settings changed";
10913 rekey_mandatory = TRUE;
10916 conf_free(ssh->conf);
10917 ssh->conf = conf_copy(conf);
10918 ssh_cache_conf_values(ssh);
10920 if (!ssh->bare_connection && rekeying) {
10921 if (!ssh->kex_in_progress) {
10922 do_ssh2_transport(ssh, rekeying, -1, NULL);
10923 } else if (rekey_mandatory) {
10924 ssh->deferred_rekey_reason = rekeying;
10930 * Called to send data down the SSH connection.
10932 static int ssh_send(void *handle, char *buf, int len)
10934 Ssh ssh = (Ssh) handle;
10936 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10939 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
10941 return ssh_sendbuffer(ssh);
10945 * Called to query the current amount of buffered stdin data.
10947 static int ssh_sendbuffer(void *handle)
10949 Ssh ssh = (Ssh) handle;
10950 int override_value;
10952 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10956 * If the SSH socket itself has backed up, add the total backup
10957 * size on that to any individual buffer on the stdin channel.
10959 override_value = 0;
10960 if (ssh->throttled_all)
10961 override_value = ssh->overall_bufsize;
10963 if (ssh->version == 1) {
10964 return override_value;
10965 } else if (ssh->version == 2) {
10966 if (!ssh->mainchan)
10967 return override_value;
10969 return (override_value +
10970 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
10977 * Called to set the size of the window from SSH's POV.
10979 static void ssh_size(void *handle, int width, int height)
10981 Ssh ssh = (Ssh) handle;
10982 struct Packet *pktout;
10984 ssh->term_width = width;
10985 ssh->term_height = height;
10987 switch (ssh->state) {
10988 case SSH_STATE_BEFORE_SIZE:
10989 case SSH_STATE_PREPACKET:
10990 case SSH_STATE_CLOSED:
10991 break; /* do nothing */
10992 case SSH_STATE_INTERMED:
10993 ssh->size_needed = TRUE; /* buffer for later */
10995 case SSH_STATE_SESSION:
10996 if (!conf_get_int(ssh->conf, CONF_nopty)) {
10997 if (ssh->version == 1) {
10998 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
10999 PKT_INT, ssh->term_height,
11000 PKT_INT, ssh->term_width,
11001 PKT_INT, 0, PKT_INT, 0, PKT_END);
11002 } else if (ssh->mainchan) {
11003 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
11005 ssh2_pkt_adduint32(pktout, ssh->term_width);
11006 ssh2_pkt_adduint32(pktout, ssh->term_height);
11007 ssh2_pkt_adduint32(pktout, 0);
11008 ssh2_pkt_adduint32(pktout, 0);
11009 ssh2_pkt_send(ssh, pktout);
11017 * Return a list of the special codes that make sense in this
11020 static const struct telnet_special *ssh_get_specials(void *handle)
11022 static const struct telnet_special ssh1_ignore_special[] = {
11023 {"IGNORE message", TS_NOP}
11025 static const struct telnet_special ssh2_ignore_special[] = {
11026 {"IGNORE message", TS_NOP},
11028 static const struct telnet_special ssh2_rekey_special[] = {
11029 {"Repeat key exchange", TS_REKEY},
11031 static const struct telnet_special ssh2_session_specials[] = {
11034 /* These are the signal names defined by RFC 4254.
11035 * They include all the ISO C signals, but are a subset of the POSIX
11036 * required signals. */
11037 {"SIGINT (Interrupt)", TS_SIGINT},
11038 {"SIGTERM (Terminate)", TS_SIGTERM},
11039 {"SIGKILL (Kill)", TS_SIGKILL},
11040 {"SIGQUIT (Quit)", TS_SIGQUIT},
11041 {"SIGHUP (Hangup)", TS_SIGHUP},
11042 {"More signals", TS_SUBMENU},
11043 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
11044 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
11045 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
11046 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
11047 {NULL, TS_EXITMENU}
11049 static const struct telnet_special specials_end[] = {
11050 {NULL, TS_EXITMENU}
11052 /* XXX review this length for any changes: */
11053 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
11054 lenof(ssh2_rekey_special) +
11055 lenof(ssh2_session_specials) +
11056 lenof(specials_end)];
11057 Ssh ssh = (Ssh) handle;
11059 #define ADD_SPECIALS(name) \
11061 assert((i + lenof(name)) <= lenof(ssh_specials)); \
11062 memcpy(&ssh_specials[i], name, sizeof name); \
11063 i += lenof(name); \
11066 if (ssh->version == 1) {
11067 /* Don't bother offering IGNORE if we've decided the remote
11068 * won't cope with it, since we wouldn't bother sending it if
11070 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11071 ADD_SPECIALS(ssh1_ignore_special);
11072 } else if (ssh->version == 2) {
11073 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
11074 ADD_SPECIALS(ssh2_ignore_special);
11075 if (!(ssh->remote_bugs & BUG_SSH2_REKEY) && !ssh->bare_connection)
11076 ADD_SPECIALS(ssh2_rekey_special);
11078 ADD_SPECIALS(ssh2_session_specials);
11079 } /* else we're not ready yet */
11082 ADD_SPECIALS(specials_end);
11083 return ssh_specials;
11087 #undef ADD_SPECIALS
11091 * Send special codes. TS_EOF is useful for `plink', so you
11092 * can send an EOF and collect resulting output (e.g. `plink
11095 static void ssh_special(void *handle, Telnet_Special code)
11097 Ssh ssh = (Ssh) handle;
11098 struct Packet *pktout;
11100 if (code == TS_EOF) {
11101 if (ssh->state != SSH_STATE_SESSION) {
11103 * Buffer the EOF in case we are pre-SESSION, so we can
11104 * send it as soon as we reach SESSION.
11106 if (code == TS_EOF)
11107 ssh->eof_needed = TRUE;
11110 if (ssh->version == 1) {
11111 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
11112 } else if (ssh->mainchan) {
11113 sshfwd_write_eof(ssh->mainchan);
11114 ssh->send_ok = 0; /* now stop trying to read from stdin */
11116 logevent("Sent EOF message");
11117 } else if (code == TS_PING || code == TS_NOP) {
11118 if (ssh->state == SSH_STATE_CLOSED
11119 || ssh->state == SSH_STATE_PREPACKET) return;
11120 if (ssh->version == 1) {
11121 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11122 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
11124 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
11125 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
11126 ssh2_pkt_addstring_start(pktout);
11127 ssh2_pkt_send_noqueue(ssh, pktout);
11130 } else if (code == TS_REKEY) {
11131 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11132 ssh->version == 2) {
11133 do_ssh2_transport(ssh, "at user request", -1, NULL);
11135 } else if (code == TS_BRK) {
11136 if (ssh->state == SSH_STATE_CLOSED
11137 || ssh->state == SSH_STATE_PREPACKET) return;
11138 if (ssh->version == 1) {
11139 logevent("Unable to send BREAK signal in SSH-1");
11140 } else if (ssh->mainchan) {
11141 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
11142 ssh2_pkt_adduint32(pktout, 0); /* default break length */
11143 ssh2_pkt_send(ssh, pktout);
11146 /* Is is a POSIX signal? */
11147 char *signame = NULL;
11148 if (code == TS_SIGABRT) signame = "ABRT";
11149 if (code == TS_SIGALRM) signame = "ALRM";
11150 if (code == TS_SIGFPE) signame = "FPE";
11151 if (code == TS_SIGHUP) signame = "HUP";
11152 if (code == TS_SIGILL) signame = "ILL";
11153 if (code == TS_SIGINT) signame = "INT";
11154 if (code == TS_SIGKILL) signame = "KILL";
11155 if (code == TS_SIGPIPE) signame = "PIPE";
11156 if (code == TS_SIGQUIT) signame = "QUIT";
11157 if (code == TS_SIGSEGV) signame = "SEGV";
11158 if (code == TS_SIGTERM) signame = "TERM";
11159 if (code == TS_SIGUSR1) signame = "USR1";
11160 if (code == TS_SIGUSR2) signame = "USR2";
11161 /* The SSH-2 protocol does in principle support arbitrary named
11162 * signals, including signame@domain, but we don't support those. */
11164 /* It's a signal. */
11165 if (ssh->version == 2 && ssh->mainchan) {
11166 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
11167 ssh2_pkt_addstring(pktout, signame);
11168 ssh2_pkt_send(ssh, pktout);
11169 logeventf(ssh, "Sent signal SIG%s", signame);
11172 /* Never heard of it. Do nothing */
11177 void *new_sock_channel(void *handle, struct PortForwarding *pf)
11179 Ssh ssh = (Ssh) handle;
11180 struct ssh_channel *c;
11181 c = snew(struct ssh_channel);
11184 ssh2_channel_init(c);
11185 c->halfopen = TRUE;
11186 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
11188 add234(ssh->channels, c);
11192 unsigned ssh_alloc_sharing_channel(Ssh ssh, void *sharing_ctx)
11194 struct ssh_channel *c;
11195 c = snew(struct ssh_channel);
11198 ssh2_channel_init(c);
11199 c->type = CHAN_SHARING;
11200 c->u.sharing.ctx = sharing_ctx;
11201 add234(ssh->channels, c);
11205 void ssh_delete_sharing_channel(Ssh ssh, unsigned localid)
11207 struct ssh_channel *c;
11209 c = find234(ssh->channels, &localid, ssh_channelfind);
11211 ssh_channel_destroy(c);
11214 void ssh_send_packet_from_downstream(Ssh ssh, unsigned id, int type,
11215 const void *data, int datalen,
11216 const char *additional_log_text)
11218 struct Packet *pkt;
11220 pkt = ssh2_pkt_init(type);
11221 pkt->downstream_id = id;
11222 pkt->additional_log_text = additional_log_text;
11223 ssh2_pkt_adddata(pkt, data, datalen);
11224 ssh2_pkt_send(ssh, pkt);
11228 * This is called when stdout/stderr (the entity to which
11229 * from_backend sends data) manages to clear some backlog.
11231 static void ssh_unthrottle(void *handle, int bufsize)
11233 Ssh ssh = (Ssh) handle;
11236 if (ssh->version == 1) {
11237 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
11238 ssh->v1_stdout_throttling = 0;
11239 ssh_throttle_conn(ssh, -1);
11242 if (ssh->mainchan) {
11243 ssh2_set_window(ssh->mainchan,
11244 bufsize < ssh->mainchan->v.v2.locmaxwin ?
11245 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
11246 if (ssh_is_simple(ssh))
11249 buflimit = ssh->mainchan->v.v2.locmaxwin;
11250 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
11251 ssh->mainchan->throttling_conn = 0;
11252 ssh_throttle_conn(ssh, -1);
11258 * Now process any SSH connection data that was stashed in our
11259 * queue while we were frozen.
11261 ssh_process_queued_incoming_data(ssh);
11264 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
11266 struct ssh_channel *c = (struct ssh_channel *)channel;
11268 struct Packet *pktout;
11270 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
11272 if (ssh->version == 1) {
11273 send_packet(ssh, SSH1_MSG_PORT_OPEN,
11274 PKT_INT, c->localid,
11277 /* PKT_STR, <org:orgport>, */
11280 pktout = ssh2_chanopen_init(c, "direct-tcpip");
11282 char *trimmed_host = host_strduptrim(hostname);
11283 ssh2_pkt_addstring(pktout, trimmed_host);
11284 sfree(trimmed_host);
11286 ssh2_pkt_adduint32(pktout, port);
11288 * We make up values for the originator data; partly it's
11289 * too much hassle to keep track, and partly I'm not
11290 * convinced the server should be told details like that
11291 * about my local network configuration.
11292 * The "originator IP address" is syntactically a numeric
11293 * IP address, and some servers (e.g., Tectia) get upset
11294 * if it doesn't match this syntax.
11296 ssh2_pkt_addstring(pktout, "0.0.0.0");
11297 ssh2_pkt_adduint32(pktout, 0);
11298 ssh2_pkt_send(ssh, pktout);
11302 static int ssh_connected(void *handle)
11304 Ssh ssh = (Ssh) handle;
11305 return ssh->s != NULL;
11308 static int ssh_sendok(void *handle)
11310 Ssh ssh = (Ssh) handle;
11311 return ssh->send_ok;
11314 static int ssh_ldisc(void *handle, int option)
11316 Ssh ssh = (Ssh) handle;
11317 if (option == LD_ECHO)
11318 return ssh->echoing;
11319 if (option == LD_EDIT)
11320 return ssh->editing;
11324 static void ssh_provide_ldisc(void *handle, void *ldisc)
11326 Ssh ssh = (Ssh) handle;
11327 ssh->ldisc = ldisc;
11330 static void ssh_provide_logctx(void *handle, void *logctx)
11332 Ssh ssh = (Ssh) handle;
11333 ssh->logctx = logctx;
11336 static int ssh_return_exitcode(void *handle)
11338 Ssh ssh = (Ssh) handle;
11339 if (ssh->s != NULL)
11342 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
11346 * cfg_info for SSH is the protocol running in this session.
11347 * (1 or 2 for the full SSH-1 or SSH-2 protocol; -1 for the bare
11348 * SSH-2 connection protocol, i.e. a downstream; 0 for not-decided-yet.)
11350 static int ssh_cfg_info(void *handle)
11352 Ssh ssh = (Ssh) handle;
11353 if (ssh->version == 0)
11354 return 0; /* don't know yet */
11355 else if (ssh->bare_connection)
11358 return ssh->version;
11362 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
11363 * that fails. This variable is the means by which scp.c can reach
11364 * into the SSH code and find out which one it got.
11366 extern int ssh_fallback_cmd(void *handle)
11368 Ssh ssh = (Ssh) handle;
11369 return ssh->fallback_cmd;
11372 Backend ssh_backend = {
11382 ssh_return_exitcode,
11386 ssh_provide_logctx,