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, NULLTOEMPTY(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, NULLTOEMPTY(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\"",
5916 msglen, NULLTOEMPTY(msg)));
5919 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
5921 /* Do nothing, because we're ignoring it! Duhh. */
5924 static void ssh1_protocol_setup(Ssh ssh)
5929 * Most messages are handled by the coroutines.
5931 for (i = 0; i < 256; i++)
5932 ssh->packet_dispatch[i] = NULL;
5935 * These special message types we install handlers for.
5937 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
5938 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
5939 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
5942 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
5943 struct Packet *pktin)
5945 unsigned char *in=(unsigned char*)vin;
5946 if (ssh->state == SSH_STATE_CLOSED)
5949 if (pktin && ssh->packet_dispatch[pktin->type]) {
5950 ssh->packet_dispatch[pktin->type](ssh, pktin);
5954 if (!ssh->protocol_initial_phase_done) {
5955 if (do_ssh1_login(ssh, in, inlen, pktin))
5956 ssh->protocol_initial_phase_done = TRUE;
5961 do_ssh1_connection(ssh, in, inlen, pktin);
5965 * Utility routine for decoding comma-separated strings in KEXINIT.
5967 static int in_commasep_string(char *needle, char *haystack, int haylen)
5970 if (!needle || !haystack) /* protect against null pointers */
5972 needlen = strlen(needle);
5975 * Is it at the start of the string?
5977 if (haylen >= needlen && /* haystack is long enough */
5978 !memcmp(needle, haystack, needlen) && /* initial match */
5979 (haylen == needlen || haystack[needlen] == ',')
5980 /* either , or EOS follows */
5984 * If not, search for the next comma and resume after that.
5985 * If no comma found, terminate.
5987 while (haylen > 0 && *haystack != ',')
5988 haylen--, haystack++;
5991 haylen--, haystack++; /* skip over comma itself */
5996 * Similar routine for checking whether we have the first string in a list.
5998 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
6001 if (!needle || !haystack) /* protect against null pointers */
6003 needlen = strlen(needle);
6005 * Is it at the start of the string?
6007 if (haylen >= needlen && /* haystack is long enough */
6008 !memcmp(needle, haystack, needlen) && /* initial match */
6009 (haylen == needlen || haystack[needlen] == ',')
6010 /* either , or EOS follows */
6018 * SSH-2 key creation method.
6019 * (Currently assumes 2 lots of any hash are sufficient to generate
6020 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
6022 #define SSH2_MKKEY_ITERS (2)
6023 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
6024 unsigned char *keyspace)
6026 const struct ssh_hash *h = ssh->kex->hash;
6028 /* First hlen bytes. */
6030 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6031 hash_mpint(h, s, K);
6032 h->bytes(s, H, h->hlen);
6033 h->bytes(s, &chr, 1);
6034 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
6035 h->final(s, keyspace);
6036 /* Next hlen bytes. */
6038 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6039 hash_mpint(h, s, K);
6040 h->bytes(s, H, h->hlen);
6041 h->bytes(s, keyspace, h->hlen);
6042 h->final(s, keyspace + h->hlen);
6046 * Handle the SSH-2 transport layer.
6048 static void do_ssh2_transport(Ssh ssh, void *vin, int inlen,
6049 struct Packet *pktin)
6051 unsigned char *in = (unsigned char *)vin;
6052 struct do_ssh2_transport_state {
6054 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
6055 Bignum p, g, e, f, K;
6058 int kex_init_value, kex_reply_value;
6059 const struct ssh_mac **maclist;
6061 const struct ssh2_cipher *cscipher_tobe;
6062 const struct ssh2_cipher *sccipher_tobe;
6063 const struct ssh_mac *csmac_tobe;
6064 const struct ssh_mac *scmac_tobe;
6065 const struct ssh_compress *cscomp_tobe;
6066 const struct ssh_compress *sccomp_tobe;
6067 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
6068 int hostkeylen, siglen, rsakeylen;
6069 void *hkey; /* actual host key */
6070 void *rsakey; /* for RSA kex */
6071 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
6072 int n_preferred_kex;
6073 const struct ssh_kexes *preferred_kex[KEX_MAX];
6074 int n_preferred_ciphers;
6075 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
6076 const struct ssh_compress *preferred_comp;
6077 int userauth_succeeded; /* for delayed compression */
6078 int pending_compression;
6079 int got_session_id, activated_authconn;
6080 struct Packet *pktout;
6085 crState(do_ssh2_transport_state);
6087 assert(!ssh->bare_connection);
6091 s->cscipher_tobe = s->sccipher_tobe = NULL;
6092 s->csmac_tobe = s->scmac_tobe = NULL;
6093 s->cscomp_tobe = s->sccomp_tobe = NULL;
6095 s->got_session_id = s->activated_authconn = FALSE;
6096 s->userauth_succeeded = FALSE;
6097 s->pending_compression = FALSE;
6100 * Be prepared to work around the buggy MAC problem.
6102 if (ssh->remote_bugs & BUG_SSH2_HMAC)
6103 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
6105 s->maclist = macs, s->nmacs = lenof(macs);
6108 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
6110 int i, j, k, commalist_started;
6113 * Set up the preferred key exchange. (NULL => warn below here)
6115 s->n_preferred_kex = 0;
6116 for (i = 0; i < KEX_MAX; i++) {
6117 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
6119 s->preferred_kex[s->n_preferred_kex++] =
6120 &ssh_diffiehellman_gex;
6123 s->preferred_kex[s->n_preferred_kex++] =
6124 &ssh_diffiehellman_group14;
6127 s->preferred_kex[s->n_preferred_kex++] =
6128 &ssh_diffiehellman_group1;
6131 s->preferred_kex[s->n_preferred_kex++] =
6135 /* Flag for later. Don't bother if it's the last in
6137 if (i < KEX_MAX - 1) {
6138 s->preferred_kex[s->n_preferred_kex++] = NULL;
6145 * Set up the preferred ciphers. (NULL => warn below here)
6147 s->n_preferred_ciphers = 0;
6148 for (i = 0; i < CIPHER_MAX; i++) {
6149 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
6150 case CIPHER_BLOWFISH:
6151 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
6154 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
6155 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
6159 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
6162 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
6164 case CIPHER_ARCFOUR:
6165 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
6168 /* Flag for later. Don't bother if it's the last in
6170 if (i < CIPHER_MAX - 1) {
6171 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
6178 * Set up preferred compression.
6180 if (conf_get_int(ssh->conf, CONF_compression))
6181 s->preferred_comp = &ssh_zlib;
6183 s->preferred_comp = &ssh_comp_none;
6186 * Enable queueing of outgoing auth- or connection-layer
6187 * packets while we are in the middle of a key exchange.
6189 ssh->queueing = TRUE;
6192 * Flag that KEX is in progress.
6194 ssh->kex_in_progress = TRUE;
6197 * Construct and send our key exchange packet.
6199 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
6200 for (i = 0; i < 16; i++)
6201 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
6202 /* List key exchange algorithms. */
6203 ssh2_pkt_addstring_start(s->pktout);
6204 commalist_started = 0;
6205 for (i = 0; i < s->n_preferred_kex; i++) {
6206 const struct ssh_kexes *k = s->preferred_kex[i];
6207 if (!k) continue; /* warning flag */
6208 for (j = 0; j < k->nkexes; j++) {
6209 if (commalist_started)
6210 ssh2_pkt_addstring_str(s->pktout, ",");
6211 ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
6212 commalist_started = 1;
6215 /* List server host key algorithms. */
6216 if (!s->got_session_id) {
6218 * In the first key exchange, we list all the algorithms
6219 * we're prepared to cope with.
6221 ssh2_pkt_addstring_start(s->pktout);
6222 for (i = 0; i < lenof(hostkey_algs); i++) {
6223 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
6224 if (i < lenof(hostkey_algs) - 1)
6225 ssh2_pkt_addstring_str(s->pktout, ",");
6229 * In subsequent key exchanges, we list only the kex
6230 * algorithm that was selected in the first key exchange,
6231 * so that we keep getting the same host key and hence
6232 * don't have to interrupt the user's session to ask for
6236 ssh2_pkt_addstring(s->pktout, ssh->hostkey->name);
6238 /* List encryption algorithms (client->server then server->client). */
6239 for (k = 0; k < 2; k++) {
6240 ssh2_pkt_addstring_start(s->pktout);
6241 commalist_started = 0;
6242 for (i = 0; i < s->n_preferred_ciphers; i++) {
6243 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6244 if (!c) continue; /* warning flag */
6245 for (j = 0; j < c->nciphers; j++) {
6246 if (commalist_started)
6247 ssh2_pkt_addstring_str(s->pktout, ",");
6248 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
6249 commalist_started = 1;
6253 /* List MAC algorithms (client->server then server->client). */
6254 for (j = 0; j < 2; j++) {
6255 ssh2_pkt_addstring_start(s->pktout);
6256 for (i = 0; i < s->nmacs; i++) {
6257 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
6258 if (i < s->nmacs - 1)
6259 ssh2_pkt_addstring_str(s->pktout, ",");
6262 /* List client->server compression algorithms,
6263 * then server->client compression algorithms. (We use the
6264 * same set twice.) */
6265 for (j = 0; j < 2; j++) {
6266 ssh2_pkt_addstring_start(s->pktout);
6267 assert(lenof(compressions) > 1);
6268 /* Prefer non-delayed versions */
6269 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
6270 /* We don't even list delayed versions of algorithms until
6271 * they're allowed to be used, to avoid a race. See the end of
6273 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
6274 ssh2_pkt_addstring_str(s->pktout, ",");
6275 ssh2_pkt_addstring_str(s->pktout,
6276 s->preferred_comp->delayed_name);
6278 for (i = 0; i < lenof(compressions); i++) {
6279 const struct ssh_compress *c = compressions[i];
6280 if (c != s->preferred_comp) {
6281 ssh2_pkt_addstring_str(s->pktout, ",");
6282 ssh2_pkt_addstring_str(s->pktout, c->name);
6283 if (s->userauth_succeeded && c->delayed_name) {
6284 ssh2_pkt_addstring_str(s->pktout, ",");
6285 ssh2_pkt_addstring_str(s->pktout, c->delayed_name);
6290 /* List client->server languages. Empty list. */
6291 ssh2_pkt_addstring_start(s->pktout);
6292 /* List server->client languages. Empty list. */
6293 ssh2_pkt_addstring_start(s->pktout);
6294 /* First KEX packet does _not_ follow, because we're not that brave. */
6295 ssh2_pkt_addbool(s->pktout, FALSE);
6297 ssh2_pkt_adduint32(s->pktout, 0);
6300 s->our_kexinitlen = s->pktout->length - 5;
6301 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
6302 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
6304 ssh2_pkt_send_noqueue(ssh, s->pktout);
6307 crWaitUntilV(pktin);
6310 * Now examine the other side's KEXINIT to see what we're up
6314 char *str, *preferred;
6317 if (pktin->type != SSH2_MSG_KEXINIT) {
6318 bombout(("expected key exchange packet from server"));
6322 ssh->hostkey = NULL;
6323 s->cscipher_tobe = NULL;
6324 s->sccipher_tobe = NULL;
6325 s->csmac_tobe = NULL;
6326 s->scmac_tobe = NULL;
6327 s->cscomp_tobe = NULL;
6328 s->sccomp_tobe = NULL;
6329 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
6331 pktin->savedpos += 16; /* skip garbage cookie */
6332 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
6334 bombout(("KEXINIT packet was incomplete"));
6339 for (i = 0; i < s->n_preferred_kex; i++) {
6340 const struct ssh_kexes *k = s->preferred_kex[i];
6344 for (j = 0; j < k->nkexes; j++) {
6345 if (!preferred) preferred = k->list[j]->name;
6346 if (in_commasep_string(k->list[j]->name, str, len)) {
6347 ssh->kex = k->list[j];
6356 bombout(("Couldn't agree a key exchange algorithm"
6357 " (available: %.*s)", len, str));
6361 * Note that the server's guess is considered wrong if it doesn't match
6362 * the first algorithm in our list, even if it's still the algorithm
6365 s->guessok = first_in_commasep_string(preferred, str, len);
6366 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
6368 bombout(("KEXINIT packet was incomplete"));
6371 for (i = 0; i < lenof(hostkey_algs); i++) {
6372 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
6373 ssh->hostkey = hostkey_algs[i];
6377 if (!ssh->hostkey) {
6378 bombout(("Couldn't agree a host key algorithm"
6379 " (available: %.*s)", len, str));
6383 s->guessok = s->guessok &&
6384 first_in_commasep_string(hostkey_algs[0]->name, str, len);
6385 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
6387 bombout(("KEXINIT packet was incomplete"));
6390 for (i = 0; i < s->n_preferred_ciphers; i++) {
6391 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6393 s->warn_cscipher = TRUE;
6395 for (j = 0; j < c->nciphers; j++) {
6396 if (in_commasep_string(c->list[j]->name, str, len)) {
6397 s->cscipher_tobe = c->list[j];
6402 if (s->cscipher_tobe)
6405 if (!s->cscipher_tobe) {
6406 bombout(("Couldn't agree a client-to-server cipher"
6407 " (available: %.*s)", len, str));
6411 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
6413 bombout(("KEXINIT packet was incomplete"));
6416 for (i = 0; i < s->n_preferred_ciphers; i++) {
6417 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6419 s->warn_sccipher = TRUE;
6421 for (j = 0; j < c->nciphers; j++) {
6422 if (in_commasep_string(c->list[j]->name, str, len)) {
6423 s->sccipher_tobe = c->list[j];
6428 if (s->sccipher_tobe)
6431 if (!s->sccipher_tobe) {
6432 bombout(("Couldn't agree a server-to-client cipher"
6433 " (available: %.*s)", len, str));
6437 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
6439 bombout(("KEXINIT packet was incomplete"));
6442 for (i = 0; i < s->nmacs; i++) {
6443 if (in_commasep_string(s->maclist[i]->name, str, len)) {
6444 s->csmac_tobe = s->maclist[i];
6448 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
6450 bombout(("KEXINIT packet was incomplete"));
6453 for (i = 0; i < s->nmacs; i++) {
6454 if (in_commasep_string(s->maclist[i]->name, str, len)) {
6455 s->scmac_tobe = s->maclist[i];
6459 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
6461 bombout(("KEXINIT packet was incomplete"));
6464 for (i = 0; i < lenof(compressions) + 1; i++) {
6465 const struct ssh_compress *c =
6466 i == 0 ? s->preferred_comp : compressions[i - 1];
6467 if (in_commasep_string(c->name, str, len)) {
6470 } else if (in_commasep_string(c->delayed_name, str, len)) {
6471 if (s->userauth_succeeded) {
6475 s->pending_compression = TRUE; /* try this later */
6479 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
6481 bombout(("KEXINIT packet was incomplete"));
6484 for (i = 0; i < lenof(compressions) + 1; i++) {
6485 const struct ssh_compress *c =
6486 i == 0 ? s->preferred_comp : compressions[i - 1];
6487 if (in_commasep_string(c->name, str, len)) {
6490 } else if (in_commasep_string(c->delayed_name, str, len)) {
6491 if (s->userauth_succeeded) {
6495 s->pending_compression = TRUE; /* try this later */
6499 if (s->pending_compression) {
6500 logevent("Server supports delayed compression; "
6501 "will try this later");
6503 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
6504 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
6505 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
6507 ssh->exhash = ssh->kex->hash->init();
6508 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
6509 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
6510 hash_string(ssh->kex->hash, ssh->exhash,
6511 s->our_kexinit, s->our_kexinitlen);
6512 sfree(s->our_kexinit);
6513 /* Include the type byte in the hash of server's KEXINIT */
6514 hash_string(ssh->kex->hash, ssh->exhash,
6515 pktin->body - 1, pktin->length + 1);
6518 ssh_set_frozen(ssh, 1);
6519 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
6521 ssh_dialog_callback, ssh);
6522 if (s->dlgret < 0) {
6526 bombout(("Unexpected data from server while"
6527 " waiting for user response"));
6530 } while (pktin || inlen > 0);
6531 s->dlgret = ssh->user_response;
6533 ssh_set_frozen(ssh, 0);
6534 if (s->dlgret == 0) {
6535 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
6541 if (s->warn_cscipher) {
6542 ssh_set_frozen(ssh, 1);
6543 s->dlgret = askalg(ssh->frontend,
6544 "client-to-server cipher",
6545 s->cscipher_tobe->name,
6546 ssh_dialog_callback, ssh);
6547 if (s->dlgret < 0) {
6551 bombout(("Unexpected data from server while"
6552 " waiting for user response"));
6555 } while (pktin || inlen > 0);
6556 s->dlgret = ssh->user_response;
6558 ssh_set_frozen(ssh, 0);
6559 if (s->dlgret == 0) {
6560 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6566 if (s->warn_sccipher) {
6567 ssh_set_frozen(ssh, 1);
6568 s->dlgret = askalg(ssh->frontend,
6569 "server-to-client cipher",
6570 s->sccipher_tobe->name,
6571 ssh_dialog_callback, ssh);
6572 if (s->dlgret < 0) {
6576 bombout(("Unexpected data from server while"
6577 " waiting for user response"));
6580 } while (pktin || inlen > 0);
6581 s->dlgret = ssh->user_response;
6583 ssh_set_frozen(ssh, 0);
6584 if (s->dlgret == 0) {
6585 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6591 if (s->ignorepkt) /* first_kex_packet_follows */
6592 crWaitUntilV(pktin); /* Ignore packet */
6595 if (ssh->kex->main_type == KEXTYPE_DH) {
6597 * Work out the number of bits of key we will need from the
6598 * key exchange. We start with the maximum key length of
6604 csbits = s->cscipher_tobe->keylen;
6605 scbits = s->sccipher_tobe->keylen;
6606 s->nbits = (csbits > scbits ? csbits : scbits);
6608 /* The keys only have hlen-bit entropy, since they're based on
6609 * a hash. So cap the key size at hlen bits. */
6610 if (s->nbits > ssh->kex->hash->hlen * 8)
6611 s->nbits = ssh->kex->hash->hlen * 8;
6614 * If we're doing Diffie-Hellman group exchange, start by
6615 * requesting a group.
6617 if (!ssh->kex->pdata) {
6618 logevent("Doing Diffie-Hellman group exchange");
6619 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
6621 * Work out how big a DH group we will need to allow that
6624 s->pbits = 512 << ((s->nbits - 1) / 64);
6625 if (s->pbits < DH_MIN_SIZE)
6626 s->pbits = DH_MIN_SIZE;
6627 if (s->pbits > DH_MAX_SIZE)
6628 s->pbits = DH_MAX_SIZE;
6629 if ((ssh->remote_bugs & BUG_SSH2_OLDGEX)) {
6630 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST_OLD);
6631 ssh2_pkt_adduint32(s->pktout, s->pbits);
6633 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6634 ssh2_pkt_adduint32(s->pktout, DH_MIN_SIZE);
6635 ssh2_pkt_adduint32(s->pktout, s->pbits);
6636 ssh2_pkt_adduint32(s->pktout, DH_MAX_SIZE);
6638 ssh2_pkt_send_noqueue(ssh, s->pktout);
6640 crWaitUntilV(pktin);
6641 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6642 bombout(("expected key exchange group packet from server"));
6645 s->p = ssh2_pkt_getmp(pktin);
6646 s->g = ssh2_pkt_getmp(pktin);
6647 if (!s->p || !s->g) {
6648 bombout(("unable to read mp-ints from incoming group packet"));
6651 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6652 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6653 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6655 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
6656 ssh->kex_ctx = dh_setup_group(ssh->kex);
6657 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6658 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6659 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6660 ssh->kex->groupname);
6663 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6664 ssh->kex->hash->text_name);
6666 * Now generate and send e for Diffie-Hellman.
6668 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6669 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6670 s->pktout = ssh2_pkt_init(s->kex_init_value);
6671 ssh2_pkt_addmp(s->pktout, s->e);
6672 ssh2_pkt_send_noqueue(ssh, s->pktout);
6674 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
6675 crWaitUntilV(pktin);
6676 if (pktin->type != s->kex_reply_value) {
6677 bombout(("expected key exchange reply packet from server"));
6680 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
6681 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6682 if (!s->hostkeydata) {
6683 bombout(("unable to parse key exchange reply packet"));
6686 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6687 s->f = ssh2_pkt_getmp(pktin);
6689 bombout(("unable to parse key exchange reply packet"));
6692 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6694 bombout(("unable to parse key exchange reply packet"));
6699 const char *err = dh_validate_f(ssh->kex_ctx, s->f);
6701 bombout(("key exchange reply failed validation: %s", err));
6705 s->K = dh_find_K(ssh->kex_ctx, s->f);
6707 /* We assume everything from now on will be quick, and it might
6708 * involve user interaction. */
6709 set_busy_status(ssh->frontend, BUSY_NOT);
6711 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6712 if (!ssh->kex->pdata) {
6713 if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX))
6714 hash_uint32(ssh->kex->hash, ssh->exhash, DH_MIN_SIZE);
6715 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
6716 if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX))
6717 hash_uint32(ssh->kex->hash, ssh->exhash, DH_MAX_SIZE);
6718 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
6719 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
6721 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
6722 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
6724 dh_cleanup(ssh->kex_ctx);
6726 if (!ssh->kex->pdata) {
6731 logeventf(ssh, "Doing RSA key exchange with hash %s",
6732 ssh->kex->hash->text_name);
6733 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
6735 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6738 crWaitUntilV(pktin);
6739 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
6740 bombout(("expected RSA public key packet from server"));
6744 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6745 if (!s->hostkeydata) {
6746 bombout(("unable to parse RSA public key packet"));
6749 hash_string(ssh->kex->hash, ssh->exhash,
6750 s->hostkeydata, s->hostkeylen);
6751 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6755 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
6757 bombout(("unable to parse RSA public key packet"));
6760 s->rsakeydata = snewn(s->rsakeylen, char);
6761 memcpy(s->rsakeydata, keydata, s->rsakeylen);
6764 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
6766 sfree(s->rsakeydata);
6767 bombout(("unable to parse RSA public key from server"));
6771 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
6774 * Next, set up a shared secret K, of precisely KLEN -
6775 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6776 * RSA key modulus and HLEN is the bit length of the hash
6780 int klen = ssh_rsakex_klen(s->rsakey);
6781 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
6783 unsigned char *kstr1, *kstr2, *outstr;
6784 int kstr1len, kstr2len, outstrlen;
6786 s->K = bn_power_2(nbits - 1);
6788 for (i = 0; i < nbits; i++) {
6790 byte = random_byte();
6792 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
6796 * Encode this as an mpint.
6798 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
6799 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
6800 PUT_32BIT(kstr2, kstr1len);
6801 memcpy(kstr2 + 4, kstr1, kstr1len);
6804 * Encrypt it with the given RSA key.
6806 outstrlen = (klen + 7) / 8;
6807 outstr = snewn(outstrlen, unsigned char);
6808 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
6809 outstr, outstrlen, s->rsakey);
6812 * And send it off in a return packet.
6814 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
6815 ssh2_pkt_addstring_start(s->pktout);
6816 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
6817 ssh2_pkt_send_noqueue(ssh, s->pktout);
6819 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
6826 ssh_rsakex_freekey(s->rsakey);
6828 crWaitUntilV(pktin);
6829 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
6830 sfree(s->rsakeydata);
6831 bombout(("expected signature packet from server"));
6835 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6837 bombout(("unable to parse signature packet"));
6841 sfree(s->rsakeydata);
6844 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
6845 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
6846 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
6848 ssh->kex_ctx = NULL;
6851 debug(("Exchange hash is:\n"));
6852 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
6856 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
6857 (char *)s->exchange_hash,
6858 ssh->kex->hash->hlen)) {
6859 bombout(("Server's host key did not match the signature supplied"));
6863 s->keystr = ssh->hostkey->fmtkey(s->hkey);
6864 if (!s->got_session_id) {
6866 * Authenticate remote host: verify host key. (We've already
6867 * checked the signature of the exchange hash.)
6869 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
6870 logevent("Host key fingerprint is:");
6871 logevent(s->fingerprint);
6872 /* First check against manually configured host keys. */
6873 s->dlgret = verify_ssh_manual_host_key(ssh, s->fingerprint,
6874 ssh->hostkey, s->hkey);
6875 if (s->dlgret == 0) { /* did not match */
6876 bombout(("Host key did not appear in manually configured list"));
6878 } else if (s->dlgret < 0) { /* none configured; use standard handling */
6879 ssh_set_frozen(ssh, 1);
6880 s->dlgret = verify_ssh_host_key(ssh->frontend,
6881 ssh->savedhost, ssh->savedport,
6882 ssh->hostkey->keytype, s->keystr,
6884 ssh_dialog_callback, ssh);
6885 if (s->dlgret < 0) {
6889 bombout(("Unexpected data from server while waiting"
6890 " for user host key response"));
6893 } while (pktin || inlen > 0);
6894 s->dlgret = ssh->user_response;
6896 ssh_set_frozen(ssh, 0);
6897 if (s->dlgret == 0) {
6898 ssh_disconnect(ssh, "Aborted at host key verification", NULL,
6903 sfree(s->fingerprint);
6905 * Save this host key, to check against the one presented in
6906 * subsequent rekeys.
6908 ssh->hostkey_str = s->keystr;
6911 * In a rekey, we never present an interactive host key
6912 * verification request to the user. Instead, we simply
6913 * enforce that the key we're seeing this time is identical to
6914 * the one we saw before.
6916 if (strcmp(ssh->hostkey_str, s->keystr)) {
6917 bombout(("Host key was different in repeat key exchange"));
6922 ssh->hostkey->freekey(s->hkey);
6925 * The exchange hash from the very first key exchange is also
6926 * the session id, used in session key construction and
6929 if (!s->got_session_id) {
6930 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
6931 memcpy(ssh->v2_session_id, s->exchange_hash,
6932 sizeof(s->exchange_hash));
6933 ssh->v2_session_id_len = ssh->kex->hash->hlen;
6934 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
6935 s->got_session_id = TRUE;
6939 * Send SSH2_MSG_NEWKEYS.
6941 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
6942 ssh2_pkt_send_noqueue(ssh, s->pktout);
6943 ssh->outgoing_data_size = 0; /* start counting from here */
6946 * We've sent client NEWKEYS, so create and initialise
6947 * client-to-server session keys.
6949 if (ssh->cs_cipher_ctx)
6950 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6951 ssh->cscipher = s->cscipher_tobe;
6952 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
6954 if (ssh->cs_mac_ctx)
6955 ssh->csmac->free_context(ssh->cs_mac_ctx);
6956 ssh->csmac = s->csmac_tobe;
6957 ssh->cs_mac_ctx = ssh->csmac->make_context();
6959 if (ssh->cs_comp_ctx)
6960 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6961 ssh->cscomp = s->cscomp_tobe;
6962 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
6965 * Set IVs on client-to-server keys. Here we use the exchange
6966 * hash from the _first_ key exchange.
6969 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6970 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6971 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
6972 assert((ssh->cscipher->keylen+7) / 8 <=
6973 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6974 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
6975 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
6976 assert(ssh->cscipher->blksize <=
6977 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6978 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
6979 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
6980 assert(ssh->csmac->len <=
6981 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6982 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
6983 smemclr(keyspace, sizeof(keyspace));
6986 logeventf(ssh, "Initialised %.200s client->server encryption",
6987 ssh->cscipher->text_name);
6988 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
6989 ssh->csmac->text_name);
6990 if (ssh->cscomp->text_name)
6991 logeventf(ssh, "Initialised %s compression",
6992 ssh->cscomp->text_name);
6995 * Now our end of the key exchange is complete, we can send all
6996 * our queued higher-layer packets.
6998 ssh->queueing = FALSE;
6999 ssh2_pkt_queuesend(ssh);
7002 * Expect SSH2_MSG_NEWKEYS from server.
7004 crWaitUntilV(pktin);
7005 if (pktin->type != SSH2_MSG_NEWKEYS) {
7006 bombout(("expected new-keys packet from server"));
7009 ssh->incoming_data_size = 0; /* start counting from here */
7012 * We've seen server NEWKEYS, so create and initialise
7013 * server-to-client session keys.
7015 if (ssh->sc_cipher_ctx)
7016 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7017 ssh->sccipher = s->sccipher_tobe;
7018 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
7020 if (ssh->sc_mac_ctx)
7021 ssh->scmac->free_context(ssh->sc_mac_ctx);
7022 ssh->scmac = s->scmac_tobe;
7023 ssh->sc_mac_ctx = ssh->scmac->make_context();
7025 if (ssh->sc_comp_ctx)
7026 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7027 ssh->sccomp = s->sccomp_tobe;
7028 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
7031 * Set IVs on server-to-client keys. Here we use the exchange
7032 * hash from the _first_ key exchange.
7035 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
7036 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7037 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
7038 assert((ssh->sccipher->keylen+7) / 8 <=
7039 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7040 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
7041 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
7042 assert(ssh->sccipher->blksize <=
7043 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7044 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
7045 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
7046 assert(ssh->scmac->len <=
7047 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7048 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
7049 smemclr(keyspace, sizeof(keyspace));
7051 logeventf(ssh, "Initialised %.200s server->client encryption",
7052 ssh->sccipher->text_name);
7053 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
7054 ssh->scmac->text_name);
7055 if (ssh->sccomp->text_name)
7056 logeventf(ssh, "Initialised %s decompression",
7057 ssh->sccomp->text_name);
7060 * Free shared secret.
7065 * Key exchange is over. Loop straight back round if we have a
7066 * deferred rekey reason.
7068 if (ssh->deferred_rekey_reason) {
7069 logevent(ssh->deferred_rekey_reason);
7071 ssh->deferred_rekey_reason = NULL;
7072 goto begin_key_exchange;
7076 * Otherwise, schedule a timer for our next rekey.
7078 ssh->kex_in_progress = FALSE;
7079 ssh->last_rekey = GETTICKCOUNT();
7080 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
7081 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7085 * Now we're encrypting. Begin returning 1 to the protocol main
7086 * function so that other things can run on top of the
7087 * transport. If we ever see a KEXINIT, we must go back to the
7090 * We _also_ go back to the start if we see pktin==NULL and
7091 * inlen negative, because this is a special signal meaning
7092 * `initiate client-driven rekey', and `in' contains a message
7093 * giving the reason for the rekey.
7095 * inlen==-1 means always initiate a rekey;
7096 * inlen==-2 means that userauth has completed successfully and
7097 * we should consider rekeying (for delayed compression).
7099 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
7100 (!pktin && inlen < 0))) {
7102 if (!ssh->protocol_initial_phase_done) {
7103 ssh->protocol_initial_phase_done = TRUE;
7105 * Allow authconn to initialise itself.
7107 do_ssh2_authconn(ssh, NULL, 0, NULL);
7112 logevent("Server initiated key re-exchange");
7116 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
7117 * delayed compression, if it's available.
7119 * draft-miller-secsh-compression-delayed-00 says that you
7120 * negotiate delayed compression in the first key exchange, and
7121 * both sides start compressing when the server has sent
7122 * USERAUTH_SUCCESS. This has a race condition -- the server
7123 * can't know when the client has seen it, and thus which incoming
7124 * packets it should treat as compressed.
7126 * Instead, we do the initial key exchange without offering the
7127 * delayed methods, but note if the server offers them; when we
7128 * get here, if a delayed method was available that was higher
7129 * on our list than what we got, we initiate a rekey in which we
7130 * _do_ list the delayed methods (and hopefully get it as a
7131 * result). Subsequent rekeys will do the same.
7133 assert(!s->userauth_succeeded); /* should only happen once */
7134 s->userauth_succeeded = TRUE;
7135 if (!s->pending_compression)
7136 /* Can't see any point rekeying. */
7137 goto wait_for_rekey; /* this is utterly horrid */
7138 /* else fall through to rekey... */
7139 s->pending_compression = FALSE;
7142 * Now we've decided to rekey.
7144 * Special case: if the server bug is set that doesn't
7145 * allow rekeying, we give a different log message and
7146 * continue waiting. (If such a server _initiates_ a rekey,
7147 * we process it anyway!)
7149 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
7150 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
7152 /* Reset the counters, so that at least this message doesn't
7153 * hit the event log _too_ often. */
7154 ssh->outgoing_data_size = 0;
7155 ssh->incoming_data_size = 0;
7156 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
7158 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7161 goto wait_for_rekey; /* this is still utterly horrid */
7163 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
7166 goto begin_key_exchange;
7172 * Add data to an SSH-2 channel output buffer.
7174 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
7177 bufchain_add(&c->v.v2.outbuffer, buf, len);
7181 * Attempt to send data on an SSH-2 channel.
7183 static int ssh2_try_send(struct ssh_channel *c)
7186 struct Packet *pktout;
7189 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
7192 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
7193 if ((unsigned)len > c->v.v2.remwindow)
7194 len = c->v.v2.remwindow;
7195 if ((unsigned)len > c->v.v2.remmaxpkt)
7196 len = c->v.v2.remmaxpkt;
7197 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
7198 ssh2_pkt_adduint32(pktout, c->remoteid);
7199 ssh2_pkt_addstring_start(pktout);
7200 ssh2_pkt_addstring_data(pktout, data, len);
7201 ssh2_pkt_send(ssh, pktout);
7202 bufchain_consume(&c->v.v2.outbuffer, len);
7203 c->v.v2.remwindow -= len;
7207 * After having sent as much data as we can, return the amount
7210 ret = bufchain_size(&c->v.v2.outbuffer);
7213 * And if there's no data pending but we need to send an EOF, send
7216 if (!ret && c->pending_eof)
7217 ssh_channel_try_eof(c);
7222 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
7225 if (c->closes & CLOSES_SENT_EOF)
7226 return; /* don't send on channels we've EOFed */
7227 bufsize = ssh2_try_send(c);
7230 case CHAN_MAINSESSION:
7231 /* stdin need not receive an unthrottle
7232 * notification since it will be polled */
7235 x11_unthrottle(c->u.x11.xconn);
7238 /* agent sockets are request/response and need no
7239 * buffer management */
7242 pfd_unthrottle(c->u.pfd.pf);
7248 static int ssh_is_simple(Ssh ssh)
7251 * We use the 'simple' variant of the SSH protocol if we're asked
7252 * to, except not if we're also doing connection-sharing (either
7253 * tunnelling our packets over an upstream or expecting to be
7254 * tunnelled over ourselves), since then the assumption that we
7255 * have only one channel to worry about is not true after all.
7257 return (conf_get_int(ssh->conf, CONF_ssh_simple) &&
7258 !ssh->bare_connection && !ssh->connshare);
7262 * Set up most of a new ssh_channel for SSH-2.
7264 static void ssh2_channel_init(struct ssh_channel *c)
7267 c->localid = alloc_channel_id(ssh);
7269 c->pending_eof = FALSE;
7270 c->throttling_conn = FALSE;
7271 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
7272 ssh_is_simple(ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
7273 c->v.v2.chanreq_head = NULL;
7274 c->v.v2.throttle_state = UNTHROTTLED;
7275 bufchain_init(&c->v.v2.outbuffer);
7279 * Construct the common parts of a CHANNEL_OPEN.
7281 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c, char *type)
7283 struct Packet *pktout;
7285 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7286 ssh2_pkt_addstring(pktout, type);
7287 ssh2_pkt_adduint32(pktout, c->localid);
7288 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7289 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7294 * CHANNEL_FAILURE doesn't come with any indication of what message
7295 * caused it, so we have to keep track of the outstanding
7296 * CHANNEL_REQUESTs ourselves.
7298 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
7299 cchandler_fn_t handler, void *ctx)
7301 struct outstanding_channel_request *ocr =
7302 snew(struct outstanding_channel_request);
7304 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7305 ocr->handler = handler;
7308 if (!c->v.v2.chanreq_head)
7309 c->v.v2.chanreq_head = ocr;
7311 c->v.v2.chanreq_tail->next = ocr;
7312 c->v.v2.chanreq_tail = ocr;
7316 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
7317 * NULL then a reply will be requested and the handler will be called
7318 * when it arrives. The returned packet is ready to have any
7319 * request-specific data added and be sent. Note that if a handler is
7320 * provided, it's essential that the request actually be sent.
7322 * The handler will usually be passed the response packet in pktin. If
7323 * pktin is NULL, this means that no reply will ever be forthcoming
7324 * (e.g. because the entire connection is being destroyed, or because
7325 * the server initiated channel closure before we saw the response)
7326 * and the handler should free any storage it's holding.
7328 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c, char *type,
7329 cchandler_fn_t handler, void *ctx)
7331 struct Packet *pktout;
7333 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7334 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7335 ssh2_pkt_adduint32(pktout, c->remoteid);
7336 ssh2_pkt_addstring(pktout, type);
7337 ssh2_pkt_addbool(pktout, handler != NULL);
7338 if (handler != NULL)
7339 ssh2_queue_chanreq_handler(c, handler, ctx);
7344 * Potentially enlarge the window on an SSH-2 channel.
7346 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
7348 static void ssh2_set_window(struct ssh_channel *c, int newwin)
7353 * Never send WINDOW_ADJUST for a channel that the remote side has
7354 * already sent EOF on; there's no point, since it won't be
7355 * sending any more data anyway. Ditto if _we've_ already sent
7358 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
7362 * Also, never widen the window for an X11 channel when we're
7363 * still waiting to see its initial auth and may yet hand it off
7366 if (c->type == CHAN_X11 && c->u.x11.initial)
7370 * If the remote end has a habit of ignoring maxpkt, limit the
7371 * window so that it has no choice (assuming it doesn't ignore the
7374 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
7375 newwin = OUR_V2_MAXPKT;
7378 * Only send a WINDOW_ADJUST if there's significantly more window
7379 * available than the other end thinks there is. This saves us
7380 * sending a WINDOW_ADJUST for every character in a shell session.
7382 * "Significant" is arbitrarily defined as half the window size.
7384 if (newwin / 2 >= c->v.v2.locwindow) {
7385 struct Packet *pktout;
7389 * In order to keep track of how much window the client
7390 * actually has available, we'd like it to acknowledge each
7391 * WINDOW_ADJUST. We can't do that directly, so we accompany
7392 * it with a CHANNEL_REQUEST that has to be acknowledged.
7394 * This is only necessary if we're opening the window wide.
7395 * If we're not, then throughput is being constrained by
7396 * something other than the maximum window size anyway.
7398 if (newwin == c->v.v2.locmaxwin &&
7399 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
7400 up = snew(unsigned);
7401 *up = newwin - c->v.v2.locwindow;
7402 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
7403 ssh2_handle_winadj_response, up);
7404 ssh2_pkt_send(ssh, pktout);
7406 if (c->v.v2.throttle_state != UNTHROTTLED)
7407 c->v.v2.throttle_state = UNTHROTTLING;
7409 /* Pretend the WINDOW_ADJUST was acked immediately. */
7410 c->v.v2.remlocwin = newwin;
7411 c->v.v2.throttle_state = THROTTLED;
7413 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7414 ssh2_pkt_adduint32(pktout, c->remoteid);
7415 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
7416 ssh2_pkt_send(ssh, pktout);
7417 c->v.v2.locwindow = newwin;
7422 * Find the channel associated with a message. If there's no channel,
7423 * or it's not properly open, make a noise about it and return NULL.
7425 static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
7427 unsigned localid = ssh_pkt_getuint32(pktin);
7428 struct ssh_channel *c;
7430 c = find234(ssh->channels, &localid, ssh_channelfind);
7432 (c->type != CHAN_SHARING && c->halfopen &&
7433 pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
7434 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
7435 char *buf = dupprintf("Received %s for %s channel %u",
7436 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
7438 c ? "half-open" : "nonexistent", localid);
7439 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
7446 static void ssh2_handle_winadj_response(struct ssh_channel *c,
7447 struct Packet *pktin, void *ctx)
7449 unsigned *sizep = ctx;
7452 * Winadj responses should always be failures. However, at least
7453 * one server ("boks_sshd") is known to return SUCCESS for channel
7454 * requests it's never heard of, such as "winadj@putty". Raised
7455 * with foxt.com as bug 090916-090424, but for the sake of a quiet
7456 * life, we don't worry about what kind of response we got.
7459 c->v.v2.remlocwin += *sizep;
7462 * winadj messages are only sent when the window is fully open, so
7463 * if we get an ack of one, we know any pending unthrottle is
7466 if (c->v.v2.throttle_state == UNTHROTTLING)
7467 c->v.v2.throttle_state = UNTHROTTLED;
7470 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
7472 struct ssh_channel *c = ssh2_channel_msg(ssh, pktin);
7473 struct outstanding_channel_request *ocr;
7476 if (c->type == CHAN_SHARING) {
7477 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7478 pktin->body, pktin->length);
7481 ocr = c->v.v2.chanreq_head;
7483 ssh2_msg_unexpected(ssh, pktin);
7486 ocr->handler(c, pktin, ocr->ctx);
7487 c->v.v2.chanreq_head = ocr->next;
7490 * We may now initiate channel-closing procedures, if that
7491 * CHANNEL_REQUEST was the last thing outstanding before we send
7494 ssh2_channel_check_close(c);
7497 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
7499 struct ssh_channel *c;
7500 c = ssh2_channel_msg(ssh, pktin);
7503 if (c->type == CHAN_SHARING) {
7504 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7505 pktin->body, pktin->length);
7508 if (!(c->closes & CLOSES_SENT_EOF)) {
7509 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
7510 ssh2_try_send_and_unthrottle(ssh, c);
7514 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
7518 struct ssh_channel *c;
7519 c = ssh2_channel_msg(ssh, pktin);
7522 if (c->type == CHAN_SHARING) {
7523 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7524 pktin->body, pktin->length);
7527 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
7528 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
7529 return; /* extended but not stderr */
7530 ssh_pkt_getstring(pktin, &data, &length);
7533 c->v.v2.locwindow -= length;
7534 c->v.v2.remlocwin -= length;
7536 case CHAN_MAINSESSION:
7538 from_backend(ssh->frontend, pktin->type ==
7539 SSH2_MSG_CHANNEL_EXTENDED_DATA,
7543 bufsize = x11_send(c->u.x11.xconn, data, length);
7546 bufsize = pfd_send(c->u.pfd.pf, data, length);
7549 while (length > 0) {
7550 if (c->u.a.lensofar < 4) {
7551 unsigned int l = min(4 - c->u.a.lensofar,
7553 memcpy(c->u.a.msglen + c->u.a.lensofar,
7557 c->u.a.lensofar += l;
7559 if (c->u.a.lensofar == 4) {
7561 4 + GET_32BIT(c->u.a.msglen);
7562 c->u.a.message = snewn(c->u.a.totallen,
7564 memcpy(c->u.a.message, c->u.a.msglen, 4);
7566 if (c->u.a.lensofar >= 4 && length > 0) {
7568 min(c->u.a.totallen - c->u.a.lensofar,
7570 memcpy(c->u.a.message + c->u.a.lensofar,
7574 c->u.a.lensofar += l;
7576 if (c->u.a.lensofar == c->u.a.totallen) {
7579 c->u.a.outstanding_requests++;
7580 if (agent_query(c->u.a.message,
7583 ssh_agentf_callback, c))
7584 ssh_agentf_callback(c, reply, replylen);
7585 sfree(c->u.a.message);
7586 c->u.a.message = NULL;
7587 c->u.a.lensofar = 0;
7594 * If it looks like the remote end hit the end of its window,
7595 * and we didn't want it to do that, think about using a
7598 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
7599 c->v.v2.locmaxwin < 0x40000000)
7600 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
7602 * If we are not buffering too much data,
7603 * enlarge the window again at the remote side.
7604 * If we are buffering too much, we may still
7605 * need to adjust the window if the server's
7608 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
7609 c->v.v2.locmaxwin - bufsize : 0);
7611 * If we're either buffering way too much data, or if we're
7612 * buffering anything at all and we're in "simple" mode,
7613 * throttle the whole channel.
7615 if ((bufsize > c->v.v2.locmaxwin || (ssh_is_simple(ssh) && bufsize>0))
7616 && !c->throttling_conn) {
7617 c->throttling_conn = 1;
7618 ssh_throttle_conn(ssh, +1);
7623 static void ssh_check_termination(Ssh ssh)
7625 if (ssh->version == 2 &&
7626 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
7627 (ssh->channels && count234(ssh->channels) == 0) &&
7628 !(ssh->connshare && share_ndownstreams(ssh->connshare) > 0)) {
7630 * We used to send SSH_MSG_DISCONNECT here, because I'd
7631 * believed that _every_ conforming SSH-2 connection had to
7632 * end with a disconnect being sent by at least one side;
7633 * apparently I was wrong and it's perfectly OK to
7634 * unceremoniously slam the connection shut when you're done,
7635 * and indeed OpenSSH feels this is more polite than sending a
7636 * DISCONNECT. So now we don't.
7638 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
7642 void ssh_sharing_downstream_connected(Ssh ssh, unsigned id,
7643 const char *peerinfo)
7646 logeventf(ssh, "Connection sharing downstream #%u connected from %s",
7649 logeventf(ssh, "Connection sharing downstream #%u connected", id);
7652 void ssh_sharing_downstream_disconnected(Ssh ssh, unsigned id)
7654 logeventf(ssh, "Connection sharing downstream #%u disconnected", id);
7655 ssh_check_termination(ssh);
7658 void ssh_sharing_logf(Ssh ssh, unsigned id, const char *logfmt, ...)
7663 va_start(ap, logfmt);
7664 buf = dupvprintf(logfmt, ap);
7667 logeventf(ssh, "Connection sharing downstream #%u: %s", id, buf);
7669 logeventf(ssh, "Connection sharing: %s", buf);
7673 static void ssh_channel_destroy(struct ssh_channel *c)
7678 case CHAN_MAINSESSION:
7679 ssh->mainchan = NULL;
7680 update_specials_menu(ssh->frontend);
7683 if (c->u.x11.xconn != NULL)
7684 x11_close(c->u.x11.xconn);
7685 logevent("Forwarded X11 connection terminated");
7688 sfree(c->u.a.message);
7691 if (c->u.pfd.pf != NULL)
7692 pfd_close(c->u.pfd.pf);
7693 logevent("Forwarded port closed");
7697 del234(ssh->channels, c);
7698 if (ssh->version == 2) {
7699 bufchain_clear(&c->v.v2.outbuffer);
7700 assert(c->v.v2.chanreq_head == NULL);
7705 * If that was the last channel left open, we might need to
7708 ssh_check_termination(ssh);
7711 static void ssh2_channel_check_close(struct ssh_channel *c)
7714 struct Packet *pktout;
7718 * If we've sent out our own CHANNEL_OPEN but not yet seen
7719 * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
7720 * it's too early to be sending close messages of any kind.
7725 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
7726 c->type == CHAN_ZOMBIE) &&
7727 !c->v.v2.chanreq_head &&
7728 !(c->closes & CLOSES_SENT_CLOSE)) {
7730 * We have both sent and received EOF (or the channel is a
7731 * zombie), and we have no outstanding channel requests, which
7732 * means the channel is in final wind-up. But we haven't sent
7733 * CLOSE, so let's do so now.
7735 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
7736 ssh2_pkt_adduint32(pktout, c->remoteid);
7737 ssh2_pkt_send(ssh, pktout);
7738 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
7741 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
7742 assert(c->v.v2.chanreq_head == NULL);
7744 * We have both sent and received CLOSE, which means we're
7745 * completely done with the channel.
7747 ssh_channel_destroy(c);
7751 static void ssh2_channel_got_eof(struct ssh_channel *c)
7753 if (c->closes & CLOSES_RCVD_EOF)
7754 return; /* already seen EOF */
7755 c->closes |= CLOSES_RCVD_EOF;
7757 if (c->type == CHAN_X11) {
7758 x11_send_eof(c->u.x11.xconn);
7759 } else if (c->type == CHAN_AGENT) {
7760 if (c->u.a.outstanding_requests == 0) {
7761 /* Manufacture an outgoing EOF in response to the incoming one. */
7762 sshfwd_write_eof(c);
7764 } else if (c->type == CHAN_SOCKDATA) {
7765 pfd_send_eof(c->u.pfd.pf);
7766 } else if (c->type == CHAN_MAINSESSION) {
7769 if (!ssh->sent_console_eof &&
7770 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
7772 * Either from_backend_eof told us that the front end
7773 * wants us to close the outgoing side of the connection
7774 * as soon as we see EOF from the far end, or else we've
7775 * unilaterally decided to do that because we've allocated
7776 * a remote pty and hence EOF isn't a particularly
7777 * meaningful concept.
7779 sshfwd_write_eof(c);
7781 ssh->sent_console_eof = TRUE;
7784 ssh2_channel_check_close(c);
7787 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
7789 struct ssh_channel *c;
7791 c = ssh2_channel_msg(ssh, pktin);
7794 if (c->type == CHAN_SHARING) {
7795 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7796 pktin->body, pktin->length);
7799 ssh2_channel_got_eof(c);
7802 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
7804 struct ssh_channel *c;
7806 c = ssh2_channel_msg(ssh, pktin);
7809 if (c->type == CHAN_SHARING) {
7810 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7811 pktin->body, pktin->length);
7816 * When we receive CLOSE on a channel, we assume it comes with an
7817 * implied EOF if we haven't seen EOF yet.
7819 ssh2_channel_got_eof(c);
7821 if (!(ssh->remote_bugs & BUG_SENDS_LATE_REQUEST_REPLY)) {
7823 * It also means we stop expecting to see replies to any
7824 * outstanding channel requests, so clean those up too.
7825 * (ssh_chanreq_init will enforce by assertion that we don't
7826 * subsequently put anything back on this list.)
7828 while (c->v.v2.chanreq_head) {
7829 struct outstanding_channel_request *ocr = c->v.v2.chanreq_head;
7830 ocr->handler(c, NULL, ocr->ctx);
7831 c->v.v2.chanreq_head = ocr->next;
7837 * And we also send an outgoing EOF, if we haven't already, on the
7838 * assumption that CLOSE is a pretty forceful announcement that
7839 * the remote side is doing away with the entire channel. (If it
7840 * had wanted to send us EOF and continue receiving data from us,
7841 * it would have just sent CHANNEL_EOF.)
7843 if (!(c->closes & CLOSES_SENT_EOF)) {
7845 * Make sure we don't read any more from whatever our local
7846 * data source is for this channel.
7849 case CHAN_MAINSESSION:
7850 ssh->send_ok = 0; /* stop trying to read from stdin */
7853 x11_override_throttle(c->u.x11.xconn, 1);
7856 pfd_override_throttle(c->u.pfd.pf, 1);
7861 * Abandon any buffered data we still wanted to send to this
7862 * channel. Receiving a CHANNEL_CLOSE is an indication that
7863 * the server really wants to get on and _destroy_ this
7864 * channel, and it isn't going to send us any further
7865 * WINDOW_ADJUSTs to permit us to send pending stuff.
7867 bufchain_clear(&c->v.v2.outbuffer);
7870 * Send outgoing EOF.
7872 sshfwd_write_eof(c);
7876 * Now process the actual close.
7878 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
7879 c->closes |= CLOSES_RCVD_CLOSE;
7880 ssh2_channel_check_close(c);
7884 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
7886 struct ssh_channel *c;
7888 c = ssh2_channel_msg(ssh, pktin);
7891 if (c->type == CHAN_SHARING) {
7892 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7893 pktin->body, pktin->length);
7896 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7897 c->remoteid = ssh_pkt_getuint32(pktin);
7898 c->halfopen = FALSE;
7899 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7900 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7902 if (c->type == CHAN_SOCKDATA_DORMANT) {
7903 c->type = CHAN_SOCKDATA;
7905 pfd_confirm(c->u.pfd.pf);
7906 } else if (c->type == CHAN_ZOMBIE) {
7908 * This case can occur if a local socket error occurred
7909 * between us sending out CHANNEL_OPEN and receiving
7910 * OPEN_CONFIRMATION. In this case, all we can do is
7911 * immediately initiate close proceedings now that we know the
7912 * server's id to put in the close message.
7914 ssh2_channel_check_close(c);
7917 * We never expect to receive OPEN_CONFIRMATION for any
7918 * *other* channel type (since only local-to-remote port
7919 * forwardings cause us to send CHANNEL_OPEN after the main
7920 * channel is live - all other auxiliary channel types are
7921 * initiated from the server end). It's safe to enforce this
7922 * by assertion rather than by ssh_disconnect, because the
7923 * real point is that we never constructed a half-open channel
7924 * structure in the first place with any type other than the
7927 assert(!"Funny channel type in ssh2_msg_channel_open_confirmation");
7931 ssh_channel_try_eof(c); /* in case we had a pending EOF */
7934 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
7936 static const char *const reasons[] = {
7937 "<unknown reason code>",
7938 "Administratively prohibited",
7940 "Unknown channel type",
7941 "Resource shortage",
7943 unsigned reason_code;
7944 char *reason_string;
7946 struct ssh_channel *c;
7948 c = ssh2_channel_msg(ssh, pktin);
7951 if (c->type == CHAN_SHARING) {
7952 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7953 pktin->body, pktin->length);
7956 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7958 if (c->type == CHAN_SOCKDATA_DORMANT) {
7959 reason_code = ssh_pkt_getuint32(pktin);
7960 if (reason_code >= lenof(reasons))
7961 reason_code = 0; /* ensure reasons[reason_code] in range */
7962 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
7963 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
7964 reasons[reason_code], reason_length,
7965 NULLTOEMPTY(reason_string));
7967 pfd_close(c->u.pfd.pf);
7968 } else if (c->type == CHAN_ZOMBIE) {
7970 * This case can occur if a local socket error occurred
7971 * between us sending out CHANNEL_OPEN and receiving
7972 * OPEN_FAILURE. In this case, we need do nothing except allow
7973 * the code below to throw the half-open channel away.
7977 * We never expect to receive OPEN_FAILURE for any *other*
7978 * channel type (since only local-to-remote port forwardings
7979 * cause us to send CHANNEL_OPEN after the main channel is
7980 * live - all other auxiliary channel types are initiated from
7981 * the server end). It's safe to enforce this by assertion
7982 * rather than by ssh_disconnect, because the real point is
7983 * that we never constructed a half-open channel structure in
7984 * the first place with any type other than the above.
7986 assert(!"Funny channel type in ssh2_msg_channel_open_failure");
7989 del234(ssh->channels, c);
7993 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
7996 int typelen, want_reply;
7997 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
7998 struct ssh_channel *c;
7999 struct Packet *pktout;
8001 c = ssh2_channel_msg(ssh, pktin);
8004 if (c->type == CHAN_SHARING) {
8005 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8006 pktin->body, pktin->length);
8009 ssh_pkt_getstring(pktin, &type, &typelen);
8010 want_reply = ssh2_pkt_getbool(pktin);
8012 if (c->closes & CLOSES_SENT_CLOSE) {
8014 * We don't reply to channel requests after we've sent
8015 * CHANNEL_CLOSE for the channel, because our reply might
8016 * cross in the network with the other side's CHANNEL_CLOSE
8017 * and arrive after they have wound the channel up completely.
8023 * Having got the channel number, we now look at
8024 * the request type string to see if it's something
8027 if (c == ssh->mainchan) {
8029 * We recognise "exit-status" and "exit-signal" on
8030 * the primary channel.
8032 if (typelen == 11 &&
8033 !memcmp(type, "exit-status", 11)) {
8035 ssh->exitcode = ssh_pkt_getuint32(pktin);
8036 logeventf(ssh, "Server sent command exit status %d",
8038 reply = SSH2_MSG_CHANNEL_SUCCESS;
8040 } else if (typelen == 11 &&
8041 !memcmp(type, "exit-signal", 11)) {
8043 int is_plausible = TRUE, is_int = FALSE;
8044 char *fmt_sig = "", *fmt_msg = "";
8046 int msglen = 0, core = FALSE;
8047 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
8048 * provide an `int' for the signal, despite its
8049 * having been a `string' in the drafts of RFC 4254 since at
8050 * least 2001. (Fixed in session.c 1.147.) Try to
8051 * infer which we can safely parse it as. */
8053 unsigned char *p = pktin->body +
8055 long len = pktin->length - pktin->savedpos;
8056 unsigned long num = GET_32BIT(p); /* what is it? */
8057 /* If it's 0, it hardly matters; assume string */
8061 int maybe_int = FALSE, maybe_str = FALSE;
8062 #define CHECK_HYPOTHESIS(offset, result) \
8065 int q = toint(offset); \
8066 if (q >= 0 && q+4 <= len) { \
8067 q = toint(q + 4 + GET_32BIT(p+q)); \
8068 if (q >= 0 && q+4 <= len && \
8069 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
8074 CHECK_HYPOTHESIS(4+1, maybe_int);
8075 CHECK_HYPOTHESIS(4+num+1, maybe_str);
8076 #undef CHECK_HYPOTHESIS
8077 if (maybe_int && !maybe_str)
8079 else if (!maybe_int && maybe_str)
8082 /* Crikey. Either or neither. Panic. */
8083 is_plausible = FALSE;
8086 ssh->exitcode = 128; /* means `unknown signal' */
8089 /* Old non-standard OpenSSH. */
8090 int signum = ssh_pkt_getuint32(pktin);
8091 fmt_sig = dupprintf(" %d", signum);
8092 ssh->exitcode = 128 + signum;
8094 /* As per RFC 4254. */
8097 ssh_pkt_getstring(pktin, &sig, &siglen);
8098 /* Signal name isn't supposed to be blank, but
8099 * let's cope gracefully if it is. */
8101 fmt_sig = dupprintf(" \"%.*s\"",
8106 * Really hideous method of translating the
8107 * signal description back into a locally
8108 * meaningful number.
8113 #define TRANSLATE_SIGNAL(s) \
8114 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
8115 ssh->exitcode = 128 + SIG ## s
8117 TRANSLATE_SIGNAL(ABRT);
8120 TRANSLATE_SIGNAL(ALRM);
8123 TRANSLATE_SIGNAL(FPE);
8126 TRANSLATE_SIGNAL(HUP);
8129 TRANSLATE_SIGNAL(ILL);
8132 TRANSLATE_SIGNAL(INT);
8135 TRANSLATE_SIGNAL(KILL);
8138 TRANSLATE_SIGNAL(PIPE);
8141 TRANSLATE_SIGNAL(QUIT);
8144 TRANSLATE_SIGNAL(SEGV);
8147 TRANSLATE_SIGNAL(TERM);
8150 TRANSLATE_SIGNAL(USR1);
8153 TRANSLATE_SIGNAL(USR2);
8155 #undef TRANSLATE_SIGNAL
8157 ssh->exitcode = 128;
8159 core = ssh2_pkt_getbool(pktin);
8160 ssh_pkt_getstring(pktin, &msg, &msglen);
8162 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
8164 /* ignore lang tag */
8165 } /* else don't attempt to parse */
8166 logeventf(ssh, "Server exited on signal%s%s%s",
8167 fmt_sig, core ? " (core dumped)" : "",
8169 if (*fmt_sig) sfree(fmt_sig);
8170 if (*fmt_msg) sfree(fmt_msg);
8171 reply = SSH2_MSG_CHANNEL_SUCCESS;
8176 * This is a channel request we don't know
8177 * about, so we now either ignore the request
8178 * or respond with CHANNEL_FAILURE, depending
8181 reply = SSH2_MSG_CHANNEL_FAILURE;
8184 pktout = ssh2_pkt_init(reply);
8185 ssh2_pkt_adduint32(pktout, c->remoteid);
8186 ssh2_pkt_send(ssh, pktout);
8190 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
8193 int typelen, want_reply;
8194 struct Packet *pktout;
8196 ssh_pkt_getstring(pktin, &type, &typelen);
8197 want_reply = ssh2_pkt_getbool(pktin);
8200 * We currently don't support any global requests
8201 * at all, so we either ignore the request or
8202 * respond with REQUEST_FAILURE, depending on
8206 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
8207 ssh2_pkt_send(ssh, pktout);
8211 struct X11FakeAuth *ssh_sharing_add_x11_display(Ssh ssh, int authtype,
8215 struct X11FakeAuth *auth;
8218 * Make up a new set of fake X11 auth data, and add it to the tree
8219 * of currently valid ones with an indication of the sharing
8220 * context that it's relevant to.
8222 auth = x11_invent_fake_auth(ssh->x11authtree, authtype);
8223 auth->share_cs = share_cs;
8224 auth->share_chan = share_chan;
8229 void ssh_sharing_remove_x11_display(Ssh ssh, struct X11FakeAuth *auth)
8231 del234(ssh->x11authtree, auth);
8232 x11_free_fake_auth(auth);
8235 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
8243 struct ssh_channel *c;
8244 unsigned remid, winsize, pktsize;
8245 unsigned our_winsize_override = 0;
8246 struct Packet *pktout;
8248 ssh_pkt_getstring(pktin, &type, &typelen);
8249 c = snew(struct ssh_channel);
8252 remid = ssh_pkt_getuint32(pktin);
8253 winsize = ssh_pkt_getuint32(pktin);
8254 pktsize = ssh_pkt_getuint32(pktin);
8256 if (typelen == 3 && !memcmp(type, "x11", 3)) {
8259 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8260 addrstr = dupprintf("%.*s", peeraddrlen, NULLTOEMPTY(peeraddr));
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, NULLTOEMPTY(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,
8302 peeraddrlen, NULLTOEMPTY(peeraddr), peerport);
8305 if (realpf == NULL) {
8306 error = "Remote port is not recognised";
8310 if (realpf->share_ctx) {
8312 * This port forwarding is on behalf of a
8313 * connection-sharing downstream, so abandon our own
8314 * channel-open procedure and just pass the message on
8317 share_got_pkt_from_server(realpf->share_ctx, pktin->type,
8318 pktin->body, pktin->length);
8323 err = pfd_connect(&c->u.pfd.pf, realpf->dhost, realpf->dport,
8324 c, ssh->conf, realpf->pfrec->addressfamily);
8325 logeventf(ssh, "Attempting to forward remote port to "
8326 "%s:%d", realpf->dhost, realpf->dport);
8328 logeventf(ssh, "Port open failed: %s", err);
8330 error = "Port open failed";
8332 logevent("Forwarded port opened successfully");
8333 c->type = CHAN_SOCKDATA;
8336 } else if (typelen == 22 &&
8337 !memcmp(type, "auth-agent@openssh.com", 22)) {
8338 if (!ssh->agentfwd_enabled)
8339 error = "Agent forwarding is not enabled";
8341 c->type = CHAN_AGENT; /* identify channel type */
8342 c->u.a.lensofar = 0;
8343 c->u.a.message = NULL;
8344 c->u.a.outstanding_requests = 0;
8347 error = "Unsupported channel type requested";
8350 c->remoteid = remid;
8351 c->halfopen = FALSE;
8353 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
8354 ssh2_pkt_adduint32(pktout, c->remoteid);
8355 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
8356 ssh2_pkt_addstring(pktout, error);
8357 ssh2_pkt_addstring(pktout, "en"); /* language tag */
8358 ssh2_pkt_send(ssh, pktout);
8359 logeventf(ssh, "Rejected channel open: %s", error);
8362 ssh2_channel_init(c);
8363 c->v.v2.remwindow = winsize;
8364 c->v.v2.remmaxpkt = pktsize;
8365 if (our_winsize_override) {
8366 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
8367 our_winsize_override;
8369 add234(ssh->channels, c);
8370 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
8371 ssh2_pkt_adduint32(pktout, c->remoteid);
8372 ssh2_pkt_adduint32(pktout, c->localid);
8373 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
8374 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8375 ssh2_pkt_send(ssh, pktout);
8379 void sshfwd_x11_sharing_handover(struct ssh_channel *c,
8380 void *share_cs, void *share_chan,
8381 const char *peer_addr, int peer_port,
8382 int endian, int protomajor, int protominor,
8383 const void *initial_data, int initial_len)
8386 * This function is called when we've just discovered that an X
8387 * forwarding channel on which we'd been handling the initial auth
8388 * ourselves turns out to be destined for a connection-sharing
8389 * downstream. So we turn the channel into a CHAN_SHARING, meaning
8390 * that we completely stop tracking windows and buffering data and
8391 * just pass more or less unmodified SSH messages back and forth.
8393 c->type = CHAN_SHARING;
8394 c->u.sharing.ctx = share_cs;
8395 share_setup_x11_channel(share_cs, share_chan,
8396 c->localid, c->remoteid, c->v.v2.remwindow,
8397 c->v.v2.remmaxpkt, c->v.v2.locwindow,
8398 peer_addr, peer_port, endian,
8399 protomajor, protominor,
8400 initial_data, initial_len);
8403 void sshfwd_x11_is_local(struct ssh_channel *c)
8406 * This function is called when we've just discovered that an X
8407 * forwarding channel is _not_ destined for a connection-sharing
8408 * downstream but we're going to handle it ourselves. We stop
8409 * presenting a cautiously small window and go into ordinary data
8412 c->u.x11.initial = FALSE;
8413 ssh2_set_window(c, ssh_is_simple(c->ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE);
8417 * Buffer banner messages for later display at some convenient point,
8418 * if we're going to display them.
8420 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
8422 /* Arbitrary limit to prevent unbounded inflation of buffer */
8423 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
8424 bufchain_size(&ssh->banner) <= 131072) {
8425 char *banner = NULL;
8427 ssh_pkt_getstring(pktin, &banner, &size);
8429 bufchain_add(&ssh->banner, banner, size);
8433 /* Helper function to deal with sending tty modes for "pty-req" */
8434 static void ssh2_send_ttymode(void *data, char *mode, char *val)
8436 struct Packet *pktout = (struct Packet *)data;
8438 unsigned int arg = 0;
8439 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
8440 if (i == lenof(ssh_ttymodes)) return;
8441 switch (ssh_ttymodes[i].type) {
8443 arg = ssh_tty_parse_specchar(val);
8446 arg = ssh_tty_parse_boolean(val);
8449 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
8450 ssh2_pkt_adduint32(pktout, arg);
8453 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
8456 struct ssh2_setup_x11_state {
8460 struct Packet *pktout;
8461 crStateP(ssh2_setup_x11_state, ctx);
8465 logevent("Requesting X11 forwarding");
8466 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
8468 ssh2_pkt_addbool(pktout, 0); /* many connections */
8469 ssh2_pkt_addstring(pktout, ssh->x11auth->protoname);
8470 ssh2_pkt_addstring(pktout, ssh->x11auth->datastring);
8471 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
8472 ssh2_pkt_send(ssh, pktout);
8474 /* Wait to be called back with either a response packet, or NULL
8475 * meaning clean up and free our data */
8479 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8480 logevent("X11 forwarding enabled");
8481 ssh->X11_fwd_enabled = TRUE;
8483 logevent("X11 forwarding refused");
8489 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
8492 struct ssh2_setup_agent_state {
8496 struct Packet *pktout;
8497 crStateP(ssh2_setup_agent_state, ctx);
8501 logevent("Requesting OpenSSH-style agent forwarding");
8502 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
8503 ssh2_setup_agent, s);
8504 ssh2_pkt_send(ssh, pktout);
8506 /* Wait to be called back with either a response packet, or NULL
8507 * meaning clean up and free our data */
8511 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8512 logevent("Agent forwarding enabled");
8513 ssh->agentfwd_enabled = TRUE;
8515 logevent("Agent forwarding refused");
8521 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
8524 struct ssh2_setup_pty_state {
8528 struct Packet *pktout;
8529 crStateP(ssh2_setup_pty_state, ctx);
8533 /* Unpick the terminal-speed string. */
8534 /* XXX perhaps we should allow no speeds to be sent. */
8535 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
8536 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
8537 /* Build the pty request. */
8538 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
8540 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
8541 ssh2_pkt_adduint32(pktout, ssh->term_width);
8542 ssh2_pkt_adduint32(pktout, ssh->term_height);
8543 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
8544 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
8545 ssh2_pkt_addstring_start(pktout);
8546 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
8547 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
8548 ssh2_pkt_adduint32(pktout, ssh->ispeed);
8549 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
8550 ssh2_pkt_adduint32(pktout, ssh->ospeed);
8551 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
8552 ssh2_pkt_send(ssh, pktout);
8553 ssh->state = SSH_STATE_INTERMED;
8555 /* Wait to be called back with either a response packet, or NULL
8556 * meaning clean up and free our data */
8560 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8561 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
8562 ssh->ospeed, ssh->ispeed);
8563 ssh->got_pty = TRUE;
8565 c_write_str(ssh, "Server refused to allocate pty\r\n");
8566 ssh->editing = ssh->echoing = 1;
8573 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
8576 struct ssh2_setup_env_state {
8578 int num_env, env_left, env_ok;
8581 struct Packet *pktout;
8582 crStateP(ssh2_setup_env_state, ctx);
8587 * Send environment variables.
8589 * Simplest thing here is to send all the requests at once, and
8590 * then wait for a whole bunch of successes or failures.
8596 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
8598 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
8599 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
8600 ssh2_pkt_addstring(pktout, key);
8601 ssh2_pkt_addstring(pktout, val);
8602 ssh2_pkt_send(ssh, pktout);
8607 logeventf(ssh, "Sent %d environment variables", s->num_env);
8612 s->env_left = s->num_env;
8614 while (s->env_left > 0) {
8615 /* Wait to be called back with either a response packet,
8616 * or NULL meaning clean up and free our data */
8618 if (!pktin) goto out;
8619 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
8624 if (s->env_ok == s->num_env) {
8625 logevent("All environment variables successfully set");
8626 } else if (s->env_ok == 0) {
8627 logevent("All environment variables refused");
8628 c_write_str(ssh, "Server refused to set environment variables\r\n");
8630 logeventf(ssh, "%d environment variables refused",
8631 s->num_env - s->env_ok);
8632 c_write_str(ssh, "Server refused to set all environment variables\r\n");
8640 * Handle the SSH-2 userauth and connection layers.
8642 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
8644 do_ssh2_authconn(ssh, NULL, 0, pktin);
8647 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
8651 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
8654 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
8655 struct Packet *pktin)
8657 struct do_ssh2_authconn_state {
8661 AUTH_TYPE_PUBLICKEY,
8662 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
8663 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
8665 AUTH_TYPE_GSSAPI, /* always QUIET */
8666 AUTH_TYPE_KEYBOARD_INTERACTIVE,
8667 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
8669 int done_service_req;
8670 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
8671 int tried_pubkey_config, done_agent;
8676 int kbd_inter_refused;
8677 int we_are_in, userauth_success;
8678 prompts_t *cur_prompt;
8683 void *publickey_blob;
8684 int publickey_bloblen;
8685 int publickey_encrypted;
8686 char *publickey_algorithm;
8687 char *publickey_comment;
8688 unsigned char agent_request[5], *agent_response, *agentp;
8689 int agent_responselen;
8690 unsigned char *pkblob_in_agent;
8692 char *pkblob, *alg, *commentp;
8693 int pklen, alglen, commentlen;
8694 int siglen, retlen, len;
8695 char *q, *agentreq, *ret;
8697 struct Packet *pktout;
8700 struct ssh_gss_library *gsslib;
8701 Ssh_gss_ctx gss_ctx;
8702 Ssh_gss_buf gss_buf;
8703 Ssh_gss_buf gss_rcvtok, gss_sndtok;
8704 Ssh_gss_name gss_srv_name;
8705 Ssh_gss_stat gss_stat;
8708 crState(do_ssh2_authconn_state);
8712 /* Register as a handler for all the messages this coroutine handles. */
8713 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
8714 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
8715 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
8716 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
8717 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
8718 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
8719 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
8720 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
8721 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
8722 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
8723 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
8724 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
8725 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
8726 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
8727 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
8728 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
8729 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
8730 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
8731 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
8732 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
8734 s->done_service_req = FALSE;
8735 s->we_are_in = s->userauth_success = FALSE;
8736 s->agent_response = NULL;
8738 s->tried_gssapi = FALSE;
8741 if (!ssh->bare_connection) {
8742 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
8744 * Request userauth protocol, and await a response to it.
8746 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8747 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
8748 ssh2_pkt_send(ssh, s->pktout);
8749 crWaitUntilV(pktin);
8750 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
8751 s->done_service_req = TRUE;
8753 if (!s->done_service_req) {
8755 * Request connection protocol directly, without authentication.
8757 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8758 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8759 ssh2_pkt_send(ssh, s->pktout);
8760 crWaitUntilV(pktin);
8761 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
8762 s->we_are_in = TRUE; /* no auth required */
8764 bombout(("Server refused service request"));
8769 s->we_are_in = TRUE;
8772 /* Arrange to be able to deal with any BANNERs that come in.
8773 * (We do this now as packets may come in during the next bit.) */
8774 bufchain_init(&ssh->banner);
8775 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
8776 ssh2_msg_userauth_banner;
8779 * Misc one-time setup for authentication.
8781 s->publickey_blob = NULL;
8782 if (!s->we_are_in) {
8785 * Load the public half of any configured public key file
8788 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
8789 if (!filename_is_null(s->keyfile)) {
8791 logeventf(ssh, "Reading private key file \"%.150s\"",
8792 filename_to_str(s->keyfile));
8793 keytype = key_type(s->keyfile);
8794 if (keytype == SSH_KEYTYPE_SSH2) {
8797 ssh2_userkey_loadpub(s->keyfile,
8798 &s->publickey_algorithm,
8799 &s->publickey_bloblen,
8800 &s->publickey_comment, &error);
8801 if (s->publickey_blob) {
8802 s->publickey_encrypted =
8803 ssh2_userkey_encrypted(s->keyfile, NULL);
8806 logeventf(ssh, "Unable to load private key (%s)",
8808 msgbuf = dupprintf("Unable to load private key file "
8809 "\"%.150s\" (%s)\r\n",
8810 filename_to_str(s->keyfile),
8812 c_write_str(ssh, msgbuf);
8817 logeventf(ssh, "Unable to use this key file (%s)",
8818 key_type_to_str(keytype));
8819 msgbuf = dupprintf("Unable to use key file \"%.150s\""
8821 filename_to_str(s->keyfile),
8822 key_type_to_str(keytype));
8823 c_write_str(ssh, msgbuf);
8825 s->publickey_blob = NULL;
8830 * Find out about any keys Pageant has (but if there's a
8831 * public key configured, filter out all others).
8834 s->agent_response = NULL;
8835 s->pkblob_in_agent = NULL;
8836 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
8840 logevent("Pageant is running. Requesting keys.");
8842 /* Request the keys held by the agent. */
8843 PUT_32BIT(s->agent_request, 1);
8844 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
8845 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
8846 ssh_agent_callback, ssh)) {
8850 bombout(("Unexpected data from server while"
8851 " waiting for agent response"));
8854 } while (pktin || inlen > 0);
8855 r = ssh->agent_response;
8856 s->agent_responselen = ssh->agent_response_len;
8858 s->agent_response = (unsigned char *) r;
8859 if (s->agent_response && s->agent_responselen >= 5 &&
8860 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
8863 p = s->agent_response + 5;
8864 s->nkeys = toint(GET_32BIT(p));
8867 * Vet the Pageant response to ensure that the key
8868 * count and blob lengths make sense.
8871 logeventf(ssh, "Pageant response contained a negative"
8872 " key count %d", s->nkeys);
8874 goto done_agent_query;
8876 unsigned char *q = p + 4;
8877 int lenleft = s->agent_responselen - 5 - 4;
8879 for (keyi = 0; keyi < s->nkeys; keyi++) {
8880 int bloblen, commentlen;
8882 logeventf(ssh, "Pageant response was truncated");
8884 goto done_agent_query;
8886 bloblen = toint(GET_32BIT(q));
8887 if (bloblen < 0 || bloblen > lenleft) {
8888 logeventf(ssh, "Pageant response was truncated");
8890 goto done_agent_query;
8892 lenleft -= 4 + bloblen;
8894 commentlen = toint(GET_32BIT(q));
8895 if (commentlen < 0 || commentlen > lenleft) {
8896 logeventf(ssh, "Pageant response was truncated");
8898 goto done_agent_query;
8900 lenleft -= 4 + commentlen;
8901 q += 4 + commentlen;
8906 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
8907 if (s->publickey_blob) {
8908 /* See if configured key is in agent. */
8909 for (keyi = 0; keyi < s->nkeys; keyi++) {
8910 s->pklen = toint(GET_32BIT(p));
8911 if (s->pklen == s->publickey_bloblen &&
8912 !memcmp(p+4, s->publickey_blob,
8913 s->publickey_bloblen)) {
8914 logeventf(ssh, "Pageant key #%d matches "
8915 "configured key file", keyi);
8917 s->pkblob_in_agent = p;
8921 p += toint(GET_32BIT(p)) + 4; /* comment */
8923 if (!s->pkblob_in_agent) {
8924 logevent("Configured key file not in Pageant");
8929 logevent("Failed to get reply from Pageant");
8937 * We repeat this whole loop, including the username prompt,
8938 * until we manage a successful authentication. If the user
8939 * types the wrong _password_, they can be sent back to the
8940 * beginning to try another username, if this is configured on.
8941 * (If they specify a username in the config, they are never
8942 * asked, even if they do give a wrong password.)
8944 * I think this best serves the needs of
8946 * - the people who have no configuration, no keys, and just
8947 * want to try repeated (username,password) pairs until they
8948 * type both correctly
8950 * - people who have keys and configuration but occasionally
8951 * need to fall back to passwords
8953 * - people with a key held in Pageant, who might not have
8954 * logged in to a particular machine before; so they want to
8955 * type a username, and then _either_ their key will be
8956 * accepted, _or_ they will type a password. If they mistype
8957 * the username they will want to be able to get back and
8960 s->got_username = FALSE;
8961 while (!s->we_are_in) {
8965 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
8967 * We got a username last time round this loop, and
8968 * with change_username turned off we don't try to get
8971 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
8972 int ret; /* need not be kept over crReturn */
8973 s->cur_prompt = new_prompts(ssh->frontend);
8974 s->cur_prompt->to_server = TRUE;
8975 s->cur_prompt->name = dupstr("SSH login name");
8976 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
8977 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8980 crWaitUntilV(!pktin);
8981 ret = get_userpass_input(s->cur_prompt, in, inlen);
8986 * get_userpass_input() failed to get a username.
8989 free_prompts(s->cur_prompt);
8990 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
8993 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
8994 free_prompts(s->cur_prompt);
8997 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
8998 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
8999 c_write_str(ssh, stuff);
9003 s->got_username = TRUE;
9006 * Send an authentication request using method "none": (a)
9007 * just in case it succeeds, and (b) so that we know what
9008 * authentication methods we can usefully try next.
9010 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9012 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9013 ssh2_pkt_addstring(s->pktout, ssh->username);
9014 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
9015 ssh2_pkt_addstring(s->pktout, "none"); /* method */
9016 ssh2_pkt_send(ssh, s->pktout);
9017 s->type = AUTH_TYPE_NONE;
9019 s->we_are_in = FALSE;
9021 s->tried_pubkey_config = FALSE;
9022 s->kbd_inter_refused = FALSE;
9024 /* Reset agent request state. */
9025 s->done_agent = FALSE;
9026 if (s->agent_response) {
9027 if (s->pkblob_in_agent) {
9028 s->agentp = s->pkblob_in_agent;
9030 s->agentp = s->agent_response + 5 + 4;
9036 char *methods = NULL;
9040 * Wait for the result of the last authentication request.
9043 crWaitUntilV(pktin);
9045 * Now is a convenient point to spew any banner material
9046 * that we've accumulated. (This should ensure that when
9047 * we exit the auth loop, we haven't any left to deal
9051 int size = bufchain_size(&ssh->banner);
9053 * Don't show the banner if we're operating in
9054 * non-verbose non-interactive mode. (It's probably
9055 * a script, which means nobody will read the
9056 * banner _anyway_, and moreover the printing of
9057 * the banner will screw up processing on the
9058 * output of (say) plink.)
9060 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
9061 char *banner = snewn(size, char);
9062 bufchain_fetch(&ssh->banner, banner, size);
9063 c_write_untrusted(ssh, banner, size);
9066 bufchain_clear(&ssh->banner);
9068 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
9069 logevent("Access granted");
9070 s->we_are_in = s->userauth_success = TRUE;
9074 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
9075 bombout(("Strange packet received during authentication: "
9076 "type %d", pktin->type));
9083 * OK, we're now sitting on a USERAUTH_FAILURE message, so
9084 * we can look at the string in it and know what we can
9085 * helpfully try next.
9087 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
9088 ssh_pkt_getstring(pktin, &methods, &methlen);
9089 if (!ssh2_pkt_getbool(pktin)) {
9091 * We have received an unequivocal Access
9092 * Denied. This can translate to a variety of
9093 * messages, or no message at all.
9095 * For forms of authentication which are attempted
9096 * implicitly, by which I mean without printing
9097 * anything in the window indicating that we're
9098 * trying them, we should never print 'Access
9101 * If we do print a message saying that we're
9102 * attempting some kind of authentication, it's OK
9103 * to print a followup message saying it failed -
9104 * but the message may sometimes be more specific
9105 * than simply 'Access denied'.
9107 * Additionally, if we'd just tried password
9108 * authentication, we should break out of this
9109 * whole loop so as to go back to the username
9110 * prompt (iff we're configured to allow
9111 * username change attempts).
9113 if (s->type == AUTH_TYPE_NONE) {
9115 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
9116 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
9117 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
9118 c_write_str(ssh, "Server refused our key\r\n");
9119 logevent("Server refused our key");
9120 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
9121 /* This _shouldn't_ happen except by a
9122 * protocol bug causing client and server to
9123 * disagree on what is a correct signature. */
9124 c_write_str(ssh, "Server refused public-key signature"
9125 " despite accepting key!\r\n");
9126 logevent("Server refused public-key signature"
9127 " despite accepting key!");
9128 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
9129 /* quiet, so no c_write */
9130 logevent("Server refused keyboard-interactive authentication");
9131 } else if (s->type==AUTH_TYPE_GSSAPI) {
9132 /* always quiet, so no c_write */
9133 /* also, the code down in the GSSAPI block has
9134 * already logged this in the Event Log */
9135 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
9136 logevent("Keyboard-interactive authentication failed");
9137 c_write_str(ssh, "Access denied\r\n");
9139 assert(s->type == AUTH_TYPE_PASSWORD);
9140 logevent("Password authentication failed");
9141 c_write_str(ssh, "Access denied\r\n");
9143 if (conf_get_int(ssh->conf, CONF_change_username)) {
9144 /* XXX perhaps we should allow
9145 * keyboard-interactive to do this too? */
9146 s->we_are_in = FALSE;
9151 c_write_str(ssh, "Further authentication required\r\n");
9152 logevent("Further authentication required");
9156 in_commasep_string("publickey", methods, methlen);
9158 in_commasep_string("password", methods, methlen);
9159 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
9160 in_commasep_string("keyboard-interactive", methods, methlen);
9162 if (conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
9163 in_commasep_string("gssapi-with-mic", methods, methlen)) {
9164 /* Try loading the GSS libraries and see if we
9167 ssh->gsslibs = ssh_gss_setup(ssh->conf);
9168 s->can_gssapi = (ssh->gsslibs->nlibraries > 0);
9170 /* No point in even bothering to try to load the
9171 * GSS libraries, if the user configuration and
9172 * server aren't both prepared to attempt GSSAPI
9173 * auth in the first place. */
9174 s->can_gssapi = FALSE;
9179 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9181 if (s->can_pubkey && !s->done_agent && s->nkeys) {
9184 * Attempt public-key authentication using a key from Pageant.
9187 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9189 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
9191 /* Unpack key from agent response */
9192 s->pklen = toint(GET_32BIT(s->agentp));
9194 s->pkblob = (char *)s->agentp;
9195 s->agentp += s->pklen;
9196 s->alglen = toint(GET_32BIT(s->pkblob));
9197 s->alg = s->pkblob + 4;
9198 s->commentlen = toint(GET_32BIT(s->agentp));
9200 s->commentp = (char *)s->agentp;
9201 s->agentp += s->commentlen;
9202 /* s->agentp now points at next key, if any */
9204 /* See if server will accept it */
9205 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9206 ssh2_pkt_addstring(s->pktout, ssh->username);
9207 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9208 /* service requested */
9209 ssh2_pkt_addstring(s->pktout, "publickey");
9211 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
9212 ssh2_pkt_addstring_start(s->pktout);
9213 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9214 ssh2_pkt_addstring_start(s->pktout);
9215 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9216 ssh2_pkt_send(ssh, s->pktout);
9217 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
9219 crWaitUntilV(pktin);
9220 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9222 /* Offer of key refused. */
9229 if (flags & FLAG_VERBOSE) {
9230 c_write_str(ssh, "Authenticating with "
9232 c_write(ssh, s->commentp, s->commentlen);
9233 c_write_str(ssh, "\" from agent\r\n");
9237 * Server is willing to accept the key.
9238 * Construct a SIGN_REQUEST.
9240 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9241 ssh2_pkt_addstring(s->pktout, ssh->username);
9242 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9243 /* service requested */
9244 ssh2_pkt_addstring(s->pktout, "publickey");
9246 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
9247 ssh2_pkt_addstring_start(s->pktout);
9248 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9249 ssh2_pkt_addstring_start(s->pktout);
9250 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9252 /* Ask agent for signature. */
9253 s->siglen = s->pktout->length - 5 + 4 +
9254 ssh->v2_session_id_len;
9255 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9257 s->len = 1; /* message type */
9258 s->len += 4 + s->pklen; /* key blob */
9259 s->len += 4 + s->siglen; /* data to sign */
9260 s->len += 4; /* flags */
9261 s->agentreq = snewn(4 + s->len, char);
9262 PUT_32BIT(s->agentreq, s->len);
9263 s->q = s->agentreq + 4;
9264 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
9265 PUT_32BIT(s->q, s->pklen);
9267 memcpy(s->q, s->pkblob, s->pklen);
9269 PUT_32BIT(s->q, s->siglen);
9271 /* Now the data to be signed... */
9272 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9273 PUT_32BIT(s->q, ssh->v2_session_id_len);
9276 memcpy(s->q, ssh->v2_session_id,
9277 ssh->v2_session_id_len);
9278 s->q += ssh->v2_session_id_len;
9279 memcpy(s->q, s->pktout->data + 5,
9280 s->pktout->length - 5);
9281 s->q += s->pktout->length - 5;
9282 /* And finally the (zero) flags word. */
9284 if (!agent_query(s->agentreq, s->len + 4,
9286 ssh_agent_callback, ssh)) {
9290 bombout(("Unexpected data from server"
9291 " while waiting for agent"
9295 } while (pktin || inlen > 0);
9296 vret = ssh->agent_response;
9297 s->retlen = ssh->agent_response_len;
9302 if (s->retlen >= 9 &&
9303 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
9304 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
9305 logevent("Sending Pageant's response");
9306 ssh2_add_sigblob(ssh, s->pktout,
9307 s->pkblob, s->pklen,
9309 GET_32BIT(s->ret + 5));
9310 ssh2_pkt_send(ssh, s->pktout);
9311 s->type = AUTH_TYPE_PUBLICKEY;
9313 /* FIXME: less drastic response */
9314 bombout(("Pageant failed to answer challenge"));
9320 /* Do we have any keys left to try? */
9321 if (s->pkblob_in_agent) {
9322 s->done_agent = TRUE;
9323 s->tried_pubkey_config = TRUE;
9326 if (s->keyi >= s->nkeys)
9327 s->done_agent = TRUE;
9330 } else if (s->can_pubkey && s->publickey_blob &&
9331 !s->tried_pubkey_config) {
9333 struct ssh2_userkey *key; /* not live over crReturn */
9334 char *passphrase; /* not live over crReturn */
9336 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9338 s->tried_pubkey_config = TRUE;
9341 * Try the public key supplied in the configuration.
9343 * First, offer the public blob to see if the server is
9344 * willing to accept it.
9346 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9347 ssh2_pkt_addstring(s->pktout, ssh->username);
9348 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9349 /* service requested */
9350 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
9351 ssh2_pkt_addbool(s->pktout, FALSE);
9352 /* no signature included */
9353 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
9354 ssh2_pkt_addstring_start(s->pktout);
9355 ssh2_pkt_addstring_data(s->pktout,
9356 (char *)s->publickey_blob,
9357 s->publickey_bloblen);
9358 ssh2_pkt_send(ssh, s->pktout);
9359 logevent("Offered public key");
9361 crWaitUntilV(pktin);
9362 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9363 /* Key refused. Give up. */
9364 s->gotit = TRUE; /* reconsider message next loop */
9365 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
9366 continue; /* process this new message */
9368 logevent("Offer of public key accepted");
9371 * Actually attempt a serious authentication using
9374 if (flags & FLAG_VERBOSE) {
9375 c_write_str(ssh, "Authenticating with public key \"");
9376 c_write_str(ssh, s->publickey_comment);
9377 c_write_str(ssh, "\"\r\n");
9381 const char *error; /* not live over crReturn */
9382 if (s->publickey_encrypted) {
9384 * Get a passphrase from the user.
9386 int ret; /* need not be kept over crReturn */
9387 s->cur_prompt = new_prompts(ssh->frontend);
9388 s->cur_prompt->to_server = FALSE;
9389 s->cur_prompt->name = dupstr("SSH key passphrase");
9390 add_prompt(s->cur_prompt,
9391 dupprintf("Passphrase for key \"%.100s\": ",
9392 s->publickey_comment),
9394 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9397 crWaitUntilV(!pktin);
9398 ret = get_userpass_input(s->cur_prompt,
9403 /* Failed to get a passphrase. Terminate. */
9404 free_prompts(s->cur_prompt);
9405 ssh_disconnect(ssh, NULL,
9406 "Unable to authenticate",
9407 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9412 dupstr(s->cur_prompt->prompts[0]->result);
9413 free_prompts(s->cur_prompt);
9415 passphrase = NULL; /* no passphrase needed */
9419 * Try decrypting the key.
9421 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9422 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
9424 /* burn the evidence */
9425 smemclr(passphrase, strlen(passphrase));
9428 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
9430 (key == SSH2_WRONG_PASSPHRASE)) {
9431 c_write_str(ssh, "Wrong passphrase\r\n");
9433 /* and loop again */
9435 c_write_str(ssh, "Unable to load private key (");
9436 c_write_str(ssh, error);
9437 c_write_str(ssh, ")\r\n");
9439 break; /* try something else */
9445 unsigned char *pkblob, *sigblob, *sigdata;
9446 int pkblob_len, sigblob_len, sigdata_len;
9450 * We have loaded the private key and the server
9451 * has announced that it's willing to accept it.
9452 * Hallelujah. Generate a signature and send it.
9454 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9455 ssh2_pkt_addstring(s->pktout, ssh->username);
9456 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9457 /* service requested */
9458 ssh2_pkt_addstring(s->pktout, "publickey");
9460 ssh2_pkt_addbool(s->pktout, TRUE);
9461 /* signature follows */
9462 ssh2_pkt_addstring(s->pktout, key->alg->name);
9463 pkblob = key->alg->public_blob(key->data,
9465 ssh2_pkt_addstring_start(s->pktout);
9466 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
9470 * The data to be signed is:
9474 * followed by everything so far placed in the
9477 sigdata_len = s->pktout->length - 5 + 4 +
9478 ssh->v2_session_id_len;
9479 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9481 sigdata = snewn(sigdata_len, unsigned char);
9483 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9484 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
9487 memcpy(sigdata+p, ssh->v2_session_id,
9488 ssh->v2_session_id_len);
9489 p += ssh->v2_session_id_len;
9490 memcpy(sigdata+p, s->pktout->data + 5,
9491 s->pktout->length - 5);
9492 p += s->pktout->length - 5;
9493 assert(p == sigdata_len);
9494 sigblob = key->alg->sign(key->data, (char *)sigdata,
9495 sigdata_len, &sigblob_len);
9496 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
9497 sigblob, sigblob_len);
9502 ssh2_pkt_send(ssh, s->pktout);
9503 logevent("Sent public key signature");
9504 s->type = AUTH_TYPE_PUBLICKEY;
9505 key->alg->freekey(key->data);
9506 sfree(key->comment);
9511 } else if (s->can_gssapi && !s->tried_gssapi) {
9513 /* GSSAPI Authentication */
9518 s->type = AUTH_TYPE_GSSAPI;
9519 s->tried_gssapi = TRUE;
9521 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
9524 * Pick the highest GSS library on the preference
9530 for (i = 0; i < ngsslibs; i++) {
9531 int want_id = conf_get_int_int(ssh->conf,
9532 CONF_ssh_gsslist, i);
9533 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
9534 if (ssh->gsslibs->libraries[j].id == want_id) {
9535 s->gsslib = &ssh->gsslibs->libraries[j];
9536 goto got_gsslib; /* double break */
9541 * We always expect to have found something in
9542 * the above loop: we only came here if there
9543 * was at least one viable GSS library, and the
9544 * preference list should always mention
9545 * everything and only change the order.
9550 if (s->gsslib->gsslogmsg)
9551 logevent(s->gsslib->gsslogmsg);
9553 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
9554 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9555 ssh2_pkt_addstring(s->pktout, ssh->username);
9556 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9557 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
9558 logevent("Attempting GSSAPI authentication");
9560 /* add mechanism info */
9561 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
9563 /* number of GSSAPI mechanisms */
9564 ssh2_pkt_adduint32(s->pktout,1);
9566 /* length of OID + 2 */
9567 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
9568 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
9571 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
9573 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
9575 ssh2_pkt_send(ssh, s->pktout);
9576 crWaitUntilV(pktin);
9577 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
9578 logevent("GSSAPI authentication request refused");
9582 /* check returned packet ... */
9584 ssh_pkt_getstring(pktin, &data, &len);
9585 s->gss_rcvtok.value = data;
9586 s->gss_rcvtok.length = len;
9587 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
9588 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
9589 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
9590 memcmp((char *)s->gss_rcvtok.value + 2,
9591 s->gss_buf.value,s->gss_buf.length) ) {
9592 logevent("GSSAPI authentication - wrong response from server");
9596 /* now start running */
9597 s->gss_stat = s->gsslib->import_name(s->gsslib,
9600 if (s->gss_stat != SSH_GSS_OK) {
9601 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
9602 logevent("GSSAPI import name failed - Bad service name");
9604 logevent("GSSAPI import name failed");
9608 /* fetch TGT into GSS engine */
9609 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
9611 if (s->gss_stat != SSH_GSS_OK) {
9612 logevent("GSSAPI authentication failed to get credentials");
9613 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9617 /* initial tokens are empty */
9618 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
9619 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
9621 /* now enter the loop */
9623 s->gss_stat = s->gsslib->init_sec_context
9627 conf_get_int(ssh->conf, CONF_gssapifwd),
9631 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
9632 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
9633 logevent("GSSAPI authentication initialisation failed");
9635 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
9636 &s->gss_buf) == SSH_GSS_OK) {
9637 logevent(s->gss_buf.value);
9638 sfree(s->gss_buf.value);
9643 logevent("GSSAPI authentication initialised");
9645 /* Client and server now exchange tokens until GSSAPI
9646 * no longer says CONTINUE_NEEDED */
9648 if (s->gss_sndtok.length != 0) {
9649 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
9650 ssh_pkt_addstring_start(s->pktout);
9651 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
9652 ssh2_pkt_send(ssh, s->pktout);
9653 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
9656 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
9657 crWaitUntilV(pktin);
9658 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
9659 logevent("GSSAPI authentication - bad server response");
9660 s->gss_stat = SSH_GSS_FAILURE;
9663 ssh_pkt_getstring(pktin, &data, &len);
9664 s->gss_rcvtok.value = data;
9665 s->gss_rcvtok.length = len;
9667 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
9669 if (s->gss_stat != SSH_GSS_OK) {
9670 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9671 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9674 logevent("GSSAPI authentication loop finished OK");
9676 /* Now send the MIC */
9678 s->pktout = ssh2_pkt_init(0);
9679 micoffset = s->pktout->length;
9680 ssh_pkt_addstring_start(s->pktout);
9681 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
9682 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
9683 ssh_pkt_addstring(s->pktout, ssh->username);
9684 ssh_pkt_addstring(s->pktout, "ssh-connection");
9685 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
9687 s->gss_buf.value = (char *)s->pktout->data + micoffset;
9688 s->gss_buf.length = s->pktout->length - micoffset;
9690 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
9691 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
9692 ssh_pkt_addstring_start(s->pktout);
9693 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
9694 ssh2_pkt_send(ssh, s->pktout);
9695 s->gsslib->free_mic(s->gsslib, &mic);
9699 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9700 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9703 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
9706 * Keyboard-interactive authentication.
9709 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
9711 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
9713 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9714 ssh2_pkt_addstring(s->pktout, ssh->username);
9715 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9716 /* service requested */
9717 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
9719 ssh2_pkt_addstring(s->pktout, ""); /* lang */
9720 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
9721 ssh2_pkt_send(ssh, s->pktout);
9723 logevent("Attempting keyboard-interactive authentication");
9725 crWaitUntilV(pktin);
9726 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
9727 /* Server is not willing to do keyboard-interactive
9728 * at all (or, bizarrely but legally, accepts the
9729 * user without actually issuing any prompts).
9730 * Give up on it entirely. */
9732 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
9733 s->kbd_inter_refused = TRUE; /* don't try it again */
9738 * Loop while the server continues to send INFO_REQUESTs.
9740 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
9742 char *name, *inst, *lang;
9743 int name_len, inst_len, lang_len;
9747 * We've got a fresh USERAUTH_INFO_REQUEST.
9748 * Get the preamble and start building a prompt.
9750 ssh_pkt_getstring(pktin, &name, &name_len);
9751 ssh_pkt_getstring(pktin, &inst, &inst_len);
9752 ssh_pkt_getstring(pktin, &lang, &lang_len);
9753 s->cur_prompt = new_prompts(ssh->frontend);
9754 s->cur_prompt->to_server = TRUE;
9757 * Get any prompt(s) from the packet.
9759 s->num_prompts = ssh_pkt_getuint32(pktin);
9760 for (i = 0; i < s->num_prompts; i++) {
9764 static char noprompt[] =
9765 "<server failed to send prompt>: ";
9767 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9768 echo = ssh2_pkt_getbool(pktin);
9771 prompt_len = lenof(noprompt)-1;
9773 add_prompt(s->cur_prompt,
9774 dupprintf("%.*s", prompt_len, prompt),
9779 /* FIXME: better prefix to distinguish from
9781 s->cur_prompt->name =
9782 dupprintf("SSH server: %.*s", name_len, name);
9783 s->cur_prompt->name_reqd = TRUE;
9785 s->cur_prompt->name =
9786 dupstr("SSH server authentication");
9787 s->cur_prompt->name_reqd = FALSE;
9789 /* We add a prefix to try to make it clear that a prompt
9790 * has come from the server.
9791 * FIXME: ugly to print "Using..." in prompt _every_
9792 * time round. Can this be done more subtly? */
9793 /* Special case: for reasons best known to themselves,
9794 * some servers send k-i requests with no prompts and
9795 * nothing to display. Keep quiet in this case. */
9796 if (s->num_prompts || name_len || inst_len) {
9797 s->cur_prompt->instruction =
9798 dupprintf("Using keyboard-interactive authentication.%s%.*s",
9799 inst_len ? "\n" : "", inst_len, inst);
9800 s->cur_prompt->instr_reqd = TRUE;
9802 s->cur_prompt->instr_reqd = FALSE;
9806 * Display any instructions, and get the user's
9810 int ret; /* not live over crReturn */
9811 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9814 crWaitUntilV(!pktin);
9815 ret = get_userpass_input(s->cur_prompt, in, inlen);
9820 * Failed to get responses. Terminate.
9822 free_prompts(s->cur_prompt);
9823 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9824 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9831 * Send the response(s) to the server.
9833 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
9834 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
9835 for (i=0; i < s->num_prompts; i++) {
9836 ssh2_pkt_addstring(s->pktout,
9837 s->cur_prompt->prompts[i]->result);
9839 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9842 * Free the prompts structure from this iteration.
9843 * If there's another, a new one will be allocated
9844 * when we return to the top of this while loop.
9846 free_prompts(s->cur_prompt);
9849 * Get the next packet in case it's another
9852 crWaitUntilV(pktin);
9857 * We should have SUCCESS or FAILURE now.
9861 } else if (s->can_passwd) {
9864 * Plain old password authentication.
9866 int ret; /* not live over crReturn */
9867 int changereq_first_time; /* not live over crReturn */
9869 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
9871 s->cur_prompt = new_prompts(ssh->frontend);
9872 s->cur_prompt->to_server = TRUE;
9873 s->cur_prompt->name = dupstr("SSH password");
9874 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
9879 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9882 crWaitUntilV(!pktin);
9883 ret = get_userpass_input(s->cur_prompt, in, inlen);
9888 * Failed to get responses. Terminate.
9890 free_prompts(s->cur_prompt);
9891 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9892 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9897 * Squirrel away the password. (We may need it later if
9898 * asked to change it.)
9900 s->password = dupstr(s->cur_prompt->prompts[0]->result);
9901 free_prompts(s->cur_prompt);
9904 * Send the password packet.
9906 * We pad out the password packet to 256 bytes to make
9907 * it harder for an attacker to find the length of the
9910 * Anyone using a password longer than 256 bytes
9911 * probably doesn't have much to worry about from
9912 * people who find out how long their password is!
9914 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9915 ssh2_pkt_addstring(s->pktout, ssh->username);
9916 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9917 /* service requested */
9918 ssh2_pkt_addstring(s->pktout, "password");
9919 ssh2_pkt_addbool(s->pktout, FALSE);
9920 ssh2_pkt_addstring(s->pktout, s->password);
9921 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9922 logevent("Sent password");
9923 s->type = AUTH_TYPE_PASSWORD;
9926 * Wait for next packet, in case it's a password change
9929 crWaitUntilV(pktin);
9930 changereq_first_time = TRUE;
9932 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
9935 * We're being asked for a new password
9936 * (perhaps not for the first time).
9937 * Loop until the server accepts it.
9940 int got_new = FALSE; /* not live over crReturn */
9941 char *prompt; /* not live over crReturn */
9942 int prompt_len; /* not live over crReturn */
9946 if (changereq_first_time)
9947 msg = "Server requested password change";
9949 msg = "Server rejected new password";
9951 c_write_str(ssh, msg);
9952 c_write_str(ssh, "\r\n");
9955 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9957 s->cur_prompt = new_prompts(ssh->frontend);
9958 s->cur_prompt->to_server = TRUE;
9959 s->cur_prompt->name = dupstr("New SSH password");
9960 s->cur_prompt->instruction =
9961 dupprintf("%.*s", prompt_len, NULLTOEMPTY(prompt));
9962 s->cur_prompt->instr_reqd = TRUE;
9964 * There's no explicit requirement in the protocol
9965 * for the "old" passwords in the original and
9966 * password-change messages to be the same, and
9967 * apparently some Cisco kit supports password change
9968 * by the user entering a blank password originally
9969 * and the real password subsequently, so,
9970 * reluctantly, we prompt for the old password again.
9972 * (On the other hand, some servers don't even bother
9973 * to check this field.)
9975 add_prompt(s->cur_prompt,
9976 dupstr("Current password (blank for previously entered password): "),
9978 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
9980 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
9984 * Loop until the user manages to enter the same
9989 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9992 crWaitUntilV(!pktin);
9993 ret = get_userpass_input(s->cur_prompt, in, inlen);
9998 * Failed to get responses. Terminate.
10000 /* burn the evidence */
10001 free_prompts(s->cur_prompt);
10002 smemclr(s->password, strlen(s->password));
10003 sfree(s->password);
10004 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10005 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10011 * If the user specified a new original password
10012 * (IYSWIM), overwrite any previously specified
10014 * (A side effect is that the user doesn't have to
10015 * re-enter it if they louse up the new password.)
10017 if (s->cur_prompt->prompts[0]->result[0]) {
10018 smemclr(s->password, strlen(s->password));
10019 /* burn the evidence */
10020 sfree(s->password);
10022 dupstr(s->cur_prompt->prompts[0]->result);
10026 * Check the two new passwords match.
10028 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
10029 s->cur_prompt->prompts[2]->result)
10032 /* They don't. Silly user. */
10033 c_write_str(ssh, "Passwords do not match\r\n");
10038 * Send the new password (along with the old one).
10039 * (see above for padding rationale)
10041 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10042 ssh2_pkt_addstring(s->pktout, ssh->username);
10043 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10044 /* service requested */
10045 ssh2_pkt_addstring(s->pktout, "password");
10046 ssh2_pkt_addbool(s->pktout, TRUE);
10047 ssh2_pkt_addstring(s->pktout, s->password);
10048 ssh2_pkt_addstring(s->pktout,
10049 s->cur_prompt->prompts[1]->result);
10050 free_prompts(s->cur_prompt);
10051 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10052 logevent("Sent new password");
10055 * Now see what the server has to say about it.
10056 * (If it's CHANGEREQ again, it's not happy with the
10059 crWaitUntilV(pktin);
10060 changereq_first_time = FALSE;
10065 * We need to reexamine the current pktin at the top
10066 * of the loop. Either:
10067 * - we weren't asked to change password at all, in
10068 * which case it's a SUCCESS or FAILURE with the
10070 * - we sent a new password, and the server was
10071 * either OK with it (SUCCESS or FAILURE w/partial
10072 * success) or unhappy with the _old_ password
10073 * (FAILURE w/o partial success)
10074 * In any of these cases, we go back to the top of
10075 * the loop and start again.
10080 * We don't need the old password any more, in any
10081 * case. Burn the evidence.
10083 smemclr(s->password, strlen(s->password));
10084 sfree(s->password);
10087 char *str = dupprintf("No supported authentication methods available"
10088 " (server sent: %.*s)",
10091 ssh_disconnect(ssh, str,
10092 "No supported authentication methods available",
10093 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
10103 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
10105 /* Clear up various bits and pieces from authentication. */
10106 if (s->publickey_blob) {
10107 sfree(s->publickey_blob);
10108 sfree(s->publickey_comment);
10110 if (s->agent_response)
10111 sfree(s->agent_response);
10113 if (s->userauth_success && !ssh->bare_connection) {
10115 * We've just received USERAUTH_SUCCESS, and we haven't sent any
10116 * packets since. Signal the transport layer to consider enacting
10117 * delayed compression.
10119 * (Relying on we_are_in is not sufficient, as
10120 * draft-miller-secsh-compression-delayed is quite clear that it
10121 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
10122 * become set for other reasons.)
10124 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
10127 ssh->channels = newtree234(ssh_channelcmp);
10130 * Set up handlers for some connection protocol messages, so we
10131 * don't have to handle them repeatedly in this coroutine.
10133 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
10134 ssh2_msg_channel_window_adjust;
10135 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
10136 ssh2_msg_global_request;
10139 * Create the main session channel.
10141 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
10142 ssh->mainchan = NULL;
10144 ssh->mainchan = snew(struct ssh_channel);
10145 ssh->mainchan->ssh = ssh;
10146 ssh2_channel_init(ssh->mainchan);
10148 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
10150 * Just start a direct-tcpip channel and use it as the main
10153 ssh_send_port_open(ssh->mainchan,
10154 conf_get_str(ssh->conf, CONF_ssh_nc_host),
10155 conf_get_int(ssh->conf, CONF_ssh_nc_port),
10157 ssh->ncmode = TRUE;
10159 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
10160 logevent("Opening session as main channel");
10161 ssh2_pkt_send(ssh, s->pktout);
10162 ssh->ncmode = FALSE;
10164 crWaitUntilV(pktin);
10165 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
10166 bombout(("Server refused to open channel"));
10168 /* FIXME: error data comes back in FAILURE packet */
10170 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
10171 bombout(("Server's channel confirmation cited wrong channel"));
10174 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
10175 ssh->mainchan->halfopen = FALSE;
10176 ssh->mainchan->type = CHAN_MAINSESSION;
10177 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
10178 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
10179 add234(ssh->channels, ssh->mainchan);
10180 update_specials_menu(ssh->frontend);
10181 logevent("Opened main channel");
10185 * Now we have a channel, make dispatch table entries for
10186 * general channel-based messages.
10188 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
10189 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
10190 ssh2_msg_channel_data;
10191 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
10192 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
10193 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
10194 ssh2_msg_channel_open_confirmation;
10195 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
10196 ssh2_msg_channel_open_failure;
10197 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
10198 ssh2_msg_channel_request;
10199 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
10200 ssh2_msg_channel_open;
10201 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
10202 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
10205 * Now the connection protocol is properly up and running, with
10206 * all those dispatch table entries, so it's safe to let
10207 * downstreams start trying to open extra channels through us.
10209 if (ssh->connshare)
10210 share_activate(ssh->connshare, ssh->v_s);
10212 if (ssh->mainchan && ssh_is_simple(ssh)) {
10214 * This message indicates to the server that we promise
10215 * not to try to run any other channel in parallel with
10216 * this one, so it's safe for it to advertise a very large
10217 * window and leave the flow control to TCP.
10219 s->pktout = ssh2_chanreq_init(ssh->mainchan,
10220 "simple@putty.projects.tartarus.org",
10222 ssh2_pkt_send(ssh, s->pktout);
10226 * Enable port forwardings.
10228 ssh_setup_portfwd(ssh, ssh->conf);
10230 if (ssh->mainchan && !ssh->ncmode) {
10232 * Send the CHANNEL_REQUESTS for the main session channel.
10233 * Each one is handled by its own little asynchronous
10237 /* Potentially enable X11 forwarding. */
10238 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
10240 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
10242 if (!ssh->x11disp) {
10243 /* FIXME: return an error message from x11_setup_display */
10244 logevent("X11 forwarding not enabled: unable to"
10245 " initialise X display");
10247 ssh->x11auth = x11_invent_fake_auth
10248 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
10249 ssh->x11auth->disp = ssh->x11disp;
10251 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
10255 /* Potentially enable agent forwarding. */
10256 if (ssh_agent_forwarding_permitted(ssh))
10257 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
10259 /* Now allocate a pty for the session. */
10260 if (!conf_get_int(ssh->conf, CONF_nopty))
10261 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
10263 /* Send environment variables. */
10264 ssh2_setup_env(ssh->mainchan, NULL, NULL);
10267 * Start a shell or a remote command. We may have to attempt
10268 * this twice if the config data has provided a second choice
10275 if (ssh->fallback_cmd) {
10276 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
10277 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
10279 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
10280 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
10284 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
10285 ssh2_response_authconn, NULL);
10286 ssh2_pkt_addstring(s->pktout, cmd);
10288 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
10289 ssh2_response_authconn, NULL);
10290 ssh2_pkt_addstring(s->pktout, cmd);
10292 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
10293 ssh2_response_authconn, NULL);
10295 ssh2_pkt_send(ssh, s->pktout);
10297 crWaitUntilV(pktin);
10299 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
10300 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
10301 bombout(("Unexpected response to shell/command request:"
10302 " packet type %d", pktin->type));
10306 * We failed to start the command. If this is the
10307 * fallback command, we really are finished; if it's
10308 * not, and if the fallback command exists, try falling
10309 * back to it before complaining.
10311 if (!ssh->fallback_cmd &&
10312 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
10313 logevent("Primary command failed; attempting fallback");
10314 ssh->fallback_cmd = TRUE;
10317 bombout(("Server refused to start a shell/command"));
10320 logevent("Started a shell/command");
10325 ssh->editing = ssh->echoing = TRUE;
10328 ssh->state = SSH_STATE_SESSION;
10329 if (ssh->size_needed)
10330 ssh_size(ssh, ssh->term_width, ssh->term_height);
10331 if (ssh->eof_needed)
10332 ssh_special(ssh, TS_EOF);
10338 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
10343 s->try_send = FALSE;
10347 * _All_ the connection-layer packets we expect to
10348 * receive are now handled by the dispatch table.
10349 * Anything that reaches here must be bogus.
10352 bombout(("Strange packet received: type %d", pktin->type));
10354 } else if (ssh->mainchan) {
10356 * We have spare data. Add it to the channel buffer.
10358 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
10359 s->try_send = TRUE;
10363 struct ssh_channel *c;
10365 * Try to send data on all channels if we can.
10367 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
10368 if (c->type != CHAN_SHARING)
10369 ssh2_try_send_and_unthrottle(ssh, c);
10377 * Handlers for SSH-2 messages that might arrive at any moment.
10379 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
10381 /* log reason code in disconnect message */
10383 int reason, msglen;
10385 reason = ssh_pkt_getuint32(pktin);
10386 ssh_pkt_getstring(pktin, &msg, &msglen);
10388 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
10389 buf = dupprintf("Received disconnect message (%s)",
10390 ssh2_disconnect_reasons[reason]);
10392 buf = dupprintf("Received disconnect message (unknown"
10393 " type %d)", reason);
10397 buf = dupprintf("Disconnection message text: %.*s",
10398 msglen, NULLTOEMPTY(msg));
10400 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
10402 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
10403 ssh2_disconnect_reasons[reason] : "unknown",
10404 msglen, NULLTOEMPTY(msg)));
10408 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
10410 /* log the debug message */
10414 /* XXX maybe we should actually take notice of the return value */
10415 ssh2_pkt_getbool(pktin);
10416 ssh_pkt_getstring(pktin, &msg, &msglen);
10418 logeventf(ssh, "Remote debug message: %.*s", msglen, NULLTOEMPTY(msg));
10421 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
10423 do_ssh2_transport(ssh, NULL, 0, pktin);
10427 * Called if we receive a packet that isn't allowed by the protocol.
10428 * This only applies to packets whose meaning PuTTY understands.
10429 * Entirely unknown packets are handled below.
10431 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
10433 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
10434 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
10436 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
10440 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
10442 struct Packet *pktout;
10443 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
10444 ssh2_pkt_adduint32(pktout, pktin->sequence);
10446 * UNIMPLEMENTED messages MUST appear in the same order as the
10447 * messages they respond to. Hence, never queue them.
10449 ssh2_pkt_send_noqueue(ssh, pktout);
10453 * Handle the top-level SSH-2 protocol.
10455 static void ssh2_protocol_setup(Ssh ssh)
10460 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10462 for (i = 0; i < 256; i++)
10463 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10466 * Initially, we only accept transport messages (and a few generic
10467 * ones). do_ssh2_authconn will add more when it starts.
10468 * Messages that are understood but not currently acceptable go to
10469 * ssh2_msg_unexpected.
10471 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10472 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
10473 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
10474 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
10475 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
10476 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
10477 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
10478 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
10479 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
10480 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
10481 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
10482 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
10483 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
10484 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
10485 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
10486 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
10487 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
10488 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
10489 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
10490 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10491 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10492 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10493 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10494 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10495 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10496 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10497 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10498 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10499 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10500 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10501 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10502 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10503 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10506 * These messages have a special handler from the start.
10508 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10509 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
10510 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10513 static void ssh2_bare_connection_protocol_setup(Ssh ssh)
10518 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10520 for (i = 0; i < 256; i++)
10521 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10524 * Initially, we set all ssh-connection messages to 'unexpected';
10525 * do_ssh2_authconn will fill things in properly. We also handle a
10526 * couple of messages from the transport protocol which aren't
10527 * related to key exchange (UNIMPLEMENTED, IGNORE, DEBUG,
10530 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10531 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10532 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10533 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10534 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10535 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10536 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10537 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10538 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10539 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10540 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10541 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10542 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10543 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10545 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10548 * These messages have a special handler from the start.
10550 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10551 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore;
10552 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10555 static void ssh2_timer(void *ctx, unsigned long now)
10557 Ssh ssh = (Ssh)ctx;
10559 if (ssh->state == SSH_STATE_CLOSED)
10562 if (!ssh->kex_in_progress && !ssh->bare_connection &&
10563 conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
10564 now == ssh->next_rekey) {
10565 do_ssh2_transport(ssh, "timeout", -1, NULL);
10569 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
10570 struct Packet *pktin)
10572 unsigned char *in = (unsigned char *)vin;
10573 if (ssh->state == SSH_STATE_CLOSED)
10577 ssh->incoming_data_size += pktin->encrypted_len;
10578 if (!ssh->kex_in_progress &&
10579 ssh->max_data_size != 0 &&
10580 ssh->incoming_data_size > ssh->max_data_size)
10581 do_ssh2_transport(ssh, "too much data received", -1, NULL);
10585 ssh->packet_dispatch[pktin->type](ssh, pktin);
10586 else if (!ssh->protocol_initial_phase_done)
10587 do_ssh2_transport(ssh, in, inlen, pktin);
10589 do_ssh2_authconn(ssh, in, inlen, pktin);
10592 static void ssh2_bare_connection_protocol(Ssh ssh, void *vin, int inlen,
10593 struct Packet *pktin)
10595 unsigned char *in = (unsigned char *)vin;
10596 if (ssh->state == SSH_STATE_CLOSED)
10600 ssh->packet_dispatch[pktin->type](ssh, pktin);
10602 do_ssh2_authconn(ssh, in, inlen, pktin);
10605 static void ssh_cache_conf_values(Ssh ssh)
10607 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
10611 * Called to set up the connection.
10613 * Returns an error message, or NULL on success.
10615 static const char *ssh_init(void *frontend_handle, void **backend_handle,
10616 Conf *conf, char *host, int port, char **realhost,
10617 int nodelay, int keepalive)
10622 ssh = snew(struct ssh_tag);
10623 ssh->conf = conf_copy(conf);
10624 ssh_cache_conf_values(ssh);
10625 ssh->version = 0; /* when not ready yet */
10627 ssh->cipher = NULL;
10628 ssh->v1_cipher_ctx = NULL;
10629 ssh->crcda_ctx = NULL;
10630 ssh->cscipher = NULL;
10631 ssh->cs_cipher_ctx = NULL;
10632 ssh->sccipher = NULL;
10633 ssh->sc_cipher_ctx = NULL;
10635 ssh->cs_mac_ctx = NULL;
10637 ssh->sc_mac_ctx = NULL;
10638 ssh->cscomp = NULL;
10639 ssh->cs_comp_ctx = NULL;
10640 ssh->sccomp = NULL;
10641 ssh->sc_comp_ctx = NULL;
10643 ssh->kex_ctx = NULL;
10644 ssh->hostkey = NULL;
10645 ssh->hostkey_str = NULL;
10646 ssh->exitcode = -1;
10647 ssh->close_expected = FALSE;
10648 ssh->clean_exit = FALSE;
10649 ssh->state = SSH_STATE_PREPACKET;
10650 ssh->size_needed = FALSE;
10651 ssh->eof_needed = FALSE;
10653 ssh->logctx = NULL;
10654 ssh->deferred_send_data = NULL;
10655 ssh->deferred_len = 0;
10656 ssh->deferred_size = 0;
10657 ssh->fallback_cmd = 0;
10658 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
10659 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
10660 ssh->x11disp = NULL;
10661 ssh->x11auth = NULL;
10662 ssh->x11authtree = newtree234(x11_authcmp);
10663 ssh->v1_compressing = FALSE;
10664 ssh->v2_outgoing_sequence = 0;
10665 ssh->ssh1_rdpkt_crstate = 0;
10666 ssh->ssh2_rdpkt_crstate = 0;
10667 ssh->ssh2_bare_rdpkt_crstate = 0;
10668 ssh->ssh_gotdata_crstate = 0;
10669 ssh->do_ssh1_connection_crstate = 0;
10670 ssh->do_ssh_init_state = NULL;
10671 ssh->do_ssh_connection_init_state = NULL;
10672 ssh->do_ssh1_login_state = NULL;
10673 ssh->do_ssh2_transport_state = NULL;
10674 ssh->do_ssh2_authconn_state = NULL;
10677 ssh->mainchan = NULL;
10678 ssh->throttled_all = 0;
10679 ssh->v1_stdout_throttling = 0;
10681 ssh->queuelen = ssh->queuesize = 0;
10682 ssh->queueing = FALSE;
10683 ssh->qhead = ssh->qtail = NULL;
10684 ssh->deferred_rekey_reason = NULL;
10685 bufchain_init(&ssh->queued_incoming_data);
10686 ssh->frozen = FALSE;
10687 ssh->username = NULL;
10688 ssh->sent_console_eof = FALSE;
10689 ssh->got_pty = FALSE;
10690 ssh->bare_connection = FALSE;
10691 ssh->X11_fwd_enabled = FALSE;
10692 ssh->connshare = NULL;
10693 ssh->attempting_connshare = FALSE;
10695 *backend_handle = ssh;
10698 if (crypto_startup() == 0)
10699 return "Microsoft high encryption pack not installed!";
10702 ssh->frontend = frontend_handle;
10703 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
10704 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
10706 ssh->channels = NULL;
10707 ssh->rportfwds = NULL;
10708 ssh->portfwds = NULL;
10713 ssh->conn_throttle_count = 0;
10714 ssh->overall_bufsize = 0;
10715 ssh->fallback_cmd = 0;
10717 ssh->protocol = NULL;
10719 ssh->protocol_initial_phase_done = FALSE;
10721 ssh->pinger = NULL;
10723 ssh->incoming_data_size = ssh->outgoing_data_size =
10724 ssh->deferred_data_size = 0L;
10725 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10726 CONF_ssh_rekey_data));
10727 ssh->kex_in_progress = FALSE;
10730 ssh->gsslibs = NULL;
10733 random_ref(); /* do this now - may be needed by sharing setup code */
10735 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
10744 static void ssh_free(void *handle)
10746 Ssh ssh = (Ssh) handle;
10747 struct ssh_channel *c;
10748 struct ssh_rportfwd *pf;
10749 struct X11FakeAuth *auth;
10751 if (ssh->v1_cipher_ctx)
10752 ssh->cipher->free_context(ssh->v1_cipher_ctx);
10753 if (ssh->cs_cipher_ctx)
10754 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
10755 if (ssh->sc_cipher_ctx)
10756 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
10757 if (ssh->cs_mac_ctx)
10758 ssh->csmac->free_context(ssh->cs_mac_ctx);
10759 if (ssh->sc_mac_ctx)
10760 ssh->scmac->free_context(ssh->sc_mac_ctx);
10761 if (ssh->cs_comp_ctx) {
10763 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
10765 zlib_compress_cleanup(ssh->cs_comp_ctx);
10767 if (ssh->sc_comp_ctx) {
10769 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
10771 zlib_decompress_cleanup(ssh->sc_comp_ctx);
10774 dh_cleanup(ssh->kex_ctx);
10775 sfree(ssh->savedhost);
10777 while (ssh->queuelen-- > 0)
10778 ssh_free_packet(ssh->queue[ssh->queuelen]);
10781 while (ssh->qhead) {
10782 struct queued_handler *qh = ssh->qhead;
10783 ssh->qhead = qh->next;
10786 ssh->qhead = ssh->qtail = NULL;
10788 if (ssh->channels) {
10789 while ((c = delpos234(ssh->channels, 0)) != NULL) {
10792 if (c->u.x11.xconn != NULL)
10793 x11_close(c->u.x11.xconn);
10795 case CHAN_SOCKDATA:
10796 case CHAN_SOCKDATA_DORMANT:
10797 if (c->u.pfd.pf != NULL)
10798 pfd_close(c->u.pfd.pf);
10801 if (ssh->version == 2) {
10802 struct outstanding_channel_request *ocr, *nocr;
10803 ocr = c->v.v2.chanreq_head;
10805 ocr->handler(c, NULL, ocr->ctx);
10810 bufchain_clear(&c->v.v2.outbuffer);
10814 freetree234(ssh->channels);
10815 ssh->channels = NULL;
10818 if (ssh->connshare)
10819 sharestate_free(ssh->connshare);
10821 if (ssh->rportfwds) {
10822 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
10824 freetree234(ssh->rportfwds);
10825 ssh->rportfwds = NULL;
10827 sfree(ssh->deferred_send_data);
10829 x11_free_display(ssh->x11disp);
10830 while ((auth = delpos234(ssh->x11authtree, 0)) != NULL)
10831 x11_free_fake_auth(auth);
10832 freetree234(ssh->x11authtree);
10833 sfree(ssh->do_ssh_init_state);
10834 sfree(ssh->do_ssh1_login_state);
10835 sfree(ssh->do_ssh2_transport_state);
10836 sfree(ssh->do_ssh2_authconn_state);
10839 sfree(ssh->fullhostname);
10840 sfree(ssh->hostkey_str);
10841 if (ssh->crcda_ctx) {
10842 crcda_free_context(ssh->crcda_ctx);
10843 ssh->crcda_ctx = NULL;
10846 ssh_do_close(ssh, TRUE);
10847 expire_timer_context(ssh);
10849 pinger_free(ssh->pinger);
10850 bufchain_clear(&ssh->queued_incoming_data);
10851 sfree(ssh->username);
10852 conf_free(ssh->conf);
10855 ssh_gss_cleanup(ssh->gsslibs);
10863 * Reconfigure the SSH backend.
10865 static void ssh_reconfig(void *handle, Conf *conf)
10867 Ssh ssh = (Ssh) handle;
10868 char *rekeying = NULL, rekey_mandatory = FALSE;
10869 unsigned long old_max_data_size;
10872 pinger_reconfig(ssh->pinger, ssh->conf, conf);
10874 ssh_setup_portfwd(ssh, conf);
10876 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
10877 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
10879 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
10880 unsigned long now = GETTICKCOUNT();
10882 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
10883 rekeying = "timeout shortened";
10885 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
10889 old_max_data_size = ssh->max_data_size;
10890 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10891 CONF_ssh_rekey_data));
10892 if (old_max_data_size != ssh->max_data_size &&
10893 ssh->max_data_size != 0) {
10894 if (ssh->outgoing_data_size > ssh->max_data_size ||
10895 ssh->incoming_data_size > ssh->max_data_size)
10896 rekeying = "data limit lowered";
10899 if (conf_get_int(ssh->conf, CONF_compression) !=
10900 conf_get_int(conf, CONF_compression)) {
10901 rekeying = "compression setting changed";
10902 rekey_mandatory = TRUE;
10905 for (i = 0; i < CIPHER_MAX; i++)
10906 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
10907 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
10908 rekeying = "cipher settings changed";
10909 rekey_mandatory = TRUE;
10911 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
10912 conf_get_int(conf, CONF_ssh2_des_cbc)) {
10913 rekeying = "cipher settings changed";
10914 rekey_mandatory = TRUE;
10917 conf_free(ssh->conf);
10918 ssh->conf = conf_copy(conf);
10919 ssh_cache_conf_values(ssh);
10921 if (!ssh->bare_connection && rekeying) {
10922 if (!ssh->kex_in_progress) {
10923 do_ssh2_transport(ssh, rekeying, -1, NULL);
10924 } else if (rekey_mandatory) {
10925 ssh->deferred_rekey_reason = rekeying;
10931 * Called to send data down the SSH connection.
10933 static int ssh_send(void *handle, char *buf, int len)
10935 Ssh ssh = (Ssh) handle;
10937 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10940 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
10942 return ssh_sendbuffer(ssh);
10946 * Called to query the current amount of buffered stdin data.
10948 static int ssh_sendbuffer(void *handle)
10950 Ssh ssh = (Ssh) handle;
10951 int override_value;
10953 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10957 * If the SSH socket itself has backed up, add the total backup
10958 * size on that to any individual buffer on the stdin channel.
10960 override_value = 0;
10961 if (ssh->throttled_all)
10962 override_value = ssh->overall_bufsize;
10964 if (ssh->version == 1) {
10965 return override_value;
10966 } else if (ssh->version == 2) {
10967 if (!ssh->mainchan)
10968 return override_value;
10970 return (override_value +
10971 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
10978 * Called to set the size of the window from SSH's POV.
10980 static void ssh_size(void *handle, int width, int height)
10982 Ssh ssh = (Ssh) handle;
10983 struct Packet *pktout;
10985 ssh->term_width = width;
10986 ssh->term_height = height;
10988 switch (ssh->state) {
10989 case SSH_STATE_BEFORE_SIZE:
10990 case SSH_STATE_PREPACKET:
10991 case SSH_STATE_CLOSED:
10992 break; /* do nothing */
10993 case SSH_STATE_INTERMED:
10994 ssh->size_needed = TRUE; /* buffer for later */
10996 case SSH_STATE_SESSION:
10997 if (!conf_get_int(ssh->conf, CONF_nopty)) {
10998 if (ssh->version == 1) {
10999 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
11000 PKT_INT, ssh->term_height,
11001 PKT_INT, ssh->term_width,
11002 PKT_INT, 0, PKT_INT, 0, PKT_END);
11003 } else if (ssh->mainchan) {
11004 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
11006 ssh2_pkt_adduint32(pktout, ssh->term_width);
11007 ssh2_pkt_adduint32(pktout, ssh->term_height);
11008 ssh2_pkt_adduint32(pktout, 0);
11009 ssh2_pkt_adduint32(pktout, 0);
11010 ssh2_pkt_send(ssh, pktout);
11018 * Return a list of the special codes that make sense in this
11021 static const struct telnet_special *ssh_get_specials(void *handle)
11023 static const struct telnet_special ssh1_ignore_special[] = {
11024 {"IGNORE message", TS_NOP}
11026 static const struct telnet_special ssh2_ignore_special[] = {
11027 {"IGNORE message", TS_NOP},
11029 static const struct telnet_special ssh2_rekey_special[] = {
11030 {"Repeat key exchange", TS_REKEY},
11032 static const struct telnet_special ssh2_session_specials[] = {
11035 /* These are the signal names defined by RFC 4254.
11036 * They include all the ISO C signals, but are a subset of the POSIX
11037 * required signals. */
11038 {"SIGINT (Interrupt)", TS_SIGINT},
11039 {"SIGTERM (Terminate)", TS_SIGTERM},
11040 {"SIGKILL (Kill)", TS_SIGKILL},
11041 {"SIGQUIT (Quit)", TS_SIGQUIT},
11042 {"SIGHUP (Hangup)", TS_SIGHUP},
11043 {"More signals", TS_SUBMENU},
11044 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
11045 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
11046 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
11047 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
11048 {NULL, TS_EXITMENU}
11050 static const struct telnet_special specials_end[] = {
11051 {NULL, TS_EXITMENU}
11053 /* XXX review this length for any changes: */
11054 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
11055 lenof(ssh2_rekey_special) +
11056 lenof(ssh2_session_specials) +
11057 lenof(specials_end)];
11058 Ssh ssh = (Ssh) handle;
11060 #define ADD_SPECIALS(name) \
11062 assert((i + lenof(name)) <= lenof(ssh_specials)); \
11063 memcpy(&ssh_specials[i], name, sizeof name); \
11064 i += lenof(name); \
11067 if (ssh->version == 1) {
11068 /* Don't bother offering IGNORE if we've decided the remote
11069 * won't cope with it, since we wouldn't bother sending it if
11071 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11072 ADD_SPECIALS(ssh1_ignore_special);
11073 } else if (ssh->version == 2) {
11074 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
11075 ADD_SPECIALS(ssh2_ignore_special);
11076 if (!(ssh->remote_bugs & BUG_SSH2_REKEY) && !ssh->bare_connection)
11077 ADD_SPECIALS(ssh2_rekey_special);
11079 ADD_SPECIALS(ssh2_session_specials);
11080 } /* else we're not ready yet */
11083 ADD_SPECIALS(specials_end);
11084 return ssh_specials;
11088 #undef ADD_SPECIALS
11092 * Send special codes. TS_EOF is useful for `plink', so you
11093 * can send an EOF and collect resulting output (e.g. `plink
11096 static void ssh_special(void *handle, Telnet_Special code)
11098 Ssh ssh = (Ssh) handle;
11099 struct Packet *pktout;
11101 if (code == TS_EOF) {
11102 if (ssh->state != SSH_STATE_SESSION) {
11104 * Buffer the EOF in case we are pre-SESSION, so we can
11105 * send it as soon as we reach SESSION.
11107 if (code == TS_EOF)
11108 ssh->eof_needed = TRUE;
11111 if (ssh->version == 1) {
11112 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
11113 } else if (ssh->mainchan) {
11114 sshfwd_write_eof(ssh->mainchan);
11115 ssh->send_ok = 0; /* now stop trying to read from stdin */
11117 logevent("Sent EOF message");
11118 } else if (code == TS_PING || code == TS_NOP) {
11119 if (ssh->state == SSH_STATE_CLOSED
11120 || ssh->state == SSH_STATE_PREPACKET) return;
11121 if (ssh->version == 1) {
11122 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11123 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
11125 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
11126 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
11127 ssh2_pkt_addstring_start(pktout);
11128 ssh2_pkt_send_noqueue(ssh, pktout);
11131 } else if (code == TS_REKEY) {
11132 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11133 ssh->version == 2) {
11134 do_ssh2_transport(ssh, "at user request", -1, NULL);
11136 } else if (code == TS_BRK) {
11137 if (ssh->state == SSH_STATE_CLOSED
11138 || ssh->state == SSH_STATE_PREPACKET) return;
11139 if (ssh->version == 1) {
11140 logevent("Unable to send BREAK signal in SSH-1");
11141 } else if (ssh->mainchan) {
11142 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
11143 ssh2_pkt_adduint32(pktout, 0); /* default break length */
11144 ssh2_pkt_send(ssh, pktout);
11147 /* Is is a POSIX signal? */
11148 char *signame = NULL;
11149 if (code == TS_SIGABRT) signame = "ABRT";
11150 if (code == TS_SIGALRM) signame = "ALRM";
11151 if (code == TS_SIGFPE) signame = "FPE";
11152 if (code == TS_SIGHUP) signame = "HUP";
11153 if (code == TS_SIGILL) signame = "ILL";
11154 if (code == TS_SIGINT) signame = "INT";
11155 if (code == TS_SIGKILL) signame = "KILL";
11156 if (code == TS_SIGPIPE) signame = "PIPE";
11157 if (code == TS_SIGQUIT) signame = "QUIT";
11158 if (code == TS_SIGSEGV) signame = "SEGV";
11159 if (code == TS_SIGTERM) signame = "TERM";
11160 if (code == TS_SIGUSR1) signame = "USR1";
11161 if (code == TS_SIGUSR2) signame = "USR2";
11162 /* The SSH-2 protocol does in principle support arbitrary named
11163 * signals, including signame@domain, but we don't support those. */
11165 /* It's a signal. */
11166 if (ssh->version == 2 && ssh->mainchan) {
11167 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
11168 ssh2_pkt_addstring(pktout, signame);
11169 ssh2_pkt_send(ssh, pktout);
11170 logeventf(ssh, "Sent signal SIG%s", signame);
11173 /* Never heard of it. Do nothing */
11178 void *new_sock_channel(void *handle, struct PortForwarding *pf)
11180 Ssh ssh = (Ssh) handle;
11181 struct ssh_channel *c;
11182 c = snew(struct ssh_channel);
11185 ssh2_channel_init(c);
11186 c->halfopen = TRUE;
11187 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
11189 add234(ssh->channels, c);
11193 unsigned ssh_alloc_sharing_channel(Ssh ssh, void *sharing_ctx)
11195 struct ssh_channel *c;
11196 c = snew(struct ssh_channel);
11199 ssh2_channel_init(c);
11200 c->type = CHAN_SHARING;
11201 c->u.sharing.ctx = sharing_ctx;
11202 add234(ssh->channels, c);
11206 void ssh_delete_sharing_channel(Ssh ssh, unsigned localid)
11208 struct ssh_channel *c;
11210 c = find234(ssh->channels, &localid, ssh_channelfind);
11212 ssh_channel_destroy(c);
11215 void ssh_send_packet_from_downstream(Ssh ssh, unsigned id, int type,
11216 const void *data, int datalen,
11217 const char *additional_log_text)
11219 struct Packet *pkt;
11221 pkt = ssh2_pkt_init(type);
11222 pkt->downstream_id = id;
11223 pkt->additional_log_text = additional_log_text;
11224 ssh2_pkt_adddata(pkt, data, datalen);
11225 ssh2_pkt_send(ssh, pkt);
11229 * This is called when stdout/stderr (the entity to which
11230 * from_backend sends data) manages to clear some backlog.
11232 static void ssh_unthrottle(void *handle, int bufsize)
11234 Ssh ssh = (Ssh) handle;
11237 if (ssh->version == 1) {
11238 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
11239 ssh->v1_stdout_throttling = 0;
11240 ssh_throttle_conn(ssh, -1);
11243 if (ssh->mainchan) {
11244 ssh2_set_window(ssh->mainchan,
11245 bufsize < ssh->mainchan->v.v2.locmaxwin ?
11246 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
11247 if (ssh_is_simple(ssh))
11250 buflimit = ssh->mainchan->v.v2.locmaxwin;
11251 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
11252 ssh->mainchan->throttling_conn = 0;
11253 ssh_throttle_conn(ssh, -1);
11259 * Now process any SSH connection data that was stashed in our
11260 * queue while we were frozen.
11262 ssh_process_queued_incoming_data(ssh);
11265 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
11267 struct ssh_channel *c = (struct ssh_channel *)channel;
11269 struct Packet *pktout;
11271 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
11273 if (ssh->version == 1) {
11274 send_packet(ssh, SSH1_MSG_PORT_OPEN,
11275 PKT_INT, c->localid,
11278 /* PKT_STR, <org:orgport>, */
11281 pktout = ssh2_chanopen_init(c, "direct-tcpip");
11283 char *trimmed_host = host_strduptrim(hostname);
11284 ssh2_pkt_addstring(pktout, trimmed_host);
11285 sfree(trimmed_host);
11287 ssh2_pkt_adduint32(pktout, port);
11289 * We make up values for the originator data; partly it's
11290 * too much hassle to keep track, and partly I'm not
11291 * convinced the server should be told details like that
11292 * about my local network configuration.
11293 * The "originator IP address" is syntactically a numeric
11294 * IP address, and some servers (e.g., Tectia) get upset
11295 * if it doesn't match this syntax.
11297 ssh2_pkt_addstring(pktout, "0.0.0.0");
11298 ssh2_pkt_adduint32(pktout, 0);
11299 ssh2_pkt_send(ssh, pktout);
11303 static int ssh_connected(void *handle)
11305 Ssh ssh = (Ssh) handle;
11306 return ssh->s != NULL;
11309 static int ssh_sendok(void *handle)
11311 Ssh ssh = (Ssh) handle;
11312 return ssh->send_ok;
11315 static int ssh_ldisc(void *handle, int option)
11317 Ssh ssh = (Ssh) handle;
11318 if (option == LD_ECHO)
11319 return ssh->echoing;
11320 if (option == LD_EDIT)
11321 return ssh->editing;
11325 static void ssh_provide_ldisc(void *handle, void *ldisc)
11327 Ssh ssh = (Ssh) handle;
11328 ssh->ldisc = ldisc;
11331 static void ssh_provide_logctx(void *handle, void *logctx)
11333 Ssh ssh = (Ssh) handle;
11334 ssh->logctx = logctx;
11337 static int ssh_return_exitcode(void *handle)
11339 Ssh ssh = (Ssh) handle;
11340 if (ssh->s != NULL)
11343 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
11347 * cfg_info for SSH is the protocol running in this session.
11348 * (1 or 2 for the full SSH-1 or SSH-2 protocol; -1 for the bare
11349 * SSH-2 connection protocol, i.e. a downstream; 0 for not-decided-yet.)
11351 static int ssh_cfg_info(void *handle)
11353 Ssh ssh = (Ssh) handle;
11354 if (ssh->version == 0)
11355 return 0; /* don't know yet */
11356 else if (ssh->bare_connection)
11359 return ssh->version;
11363 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
11364 * that fails. This variable is the means by which scp.c can reach
11365 * into the SSH code and find out which one it got.
11367 extern int ssh_fallback_cmd(void *handle)
11369 Ssh ssh = (Ssh) handle;
11370 return ssh->fallback_cmd;
11373 Backend ssh_backend = {
11383 ssh_return_exitcode,
11387 ssh_provide_logctx,