17 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
18 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
19 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
20 #define SSH1_CMSG_USER 4 /* 0x4 */
21 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
22 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
23 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
24 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
25 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
26 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
27 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
28 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
29 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
30 #define SSH1_SMSG_FAILURE 15 /* 0xf */
31 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
32 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
33 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
34 #define SSH1_CMSG_EOF 19 /* 0x13 */
35 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
36 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
37 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
38 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
39 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
40 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
41 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
42 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
43 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
44 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
45 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
46 #define SSH1_MSG_IGNORE 32 /* 0x20 */
47 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
48 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
49 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
50 #define SSH1_MSG_DEBUG 36 /* 0x24 */
51 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
52 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
53 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
54 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
55 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
56 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
57 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
59 #define SSH1_AUTH_TIS 5 /* 0x5 */
60 #define SSH1_AUTH_CCARD 16 /* 0x10 */
62 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
63 /* Mask for protoflags we will echo back to server if seen */
64 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
66 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
67 #define SSH2_MSG_IGNORE 2 /* 0x2 */
68 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
69 #define SSH2_MSG_DEBUG 4 /* 0x4 */
70 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
71 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
72 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
73 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
74 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
75 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
76 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
77 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
78 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
79 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
80 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
81 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
82 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
83 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
84 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
85 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
86 #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
87 #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
88 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
89 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
90 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
91 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
92 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
93 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
94 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
95 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
96 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
97 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
98 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
99 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
100 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
101 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
104 * Packet type contexts, so that ssh2_pkt_type can correctly decode
105 * the ambiguous type numbers back into the correct type strings.
107 #define SSH2_PKTCTX_DHGROUP 0x0001
108 #define SSH2_PKTCTX_DHGEX 0x0002
109 #define SSH2_PKTCTX_KEX_MASK 0x000F
110 #define SSH2_PKTCTX_PUBLICKEY 0x0010
111 #define SSH2_PKTCTX_PASSWORD 0x0020
112 #define SSH2_PKTCTX_KBDINTER 0x0040
113 #define SSH2_PKTCTX_AUTH_MASK 0x00F0
115 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
116 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
117 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
118 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
119 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
120 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
121 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
122 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
123 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
124 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
125 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
126 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
127 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
128 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
129 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
131 static const char *const ssh2_disconnect_reasons[] = {
133 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
134 "SSH_DISCONNECT_PROTOCOL_ERROR",
135 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
136 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
137 "SSH_DISCONNECT_MAC_ERROR",
138 "SSH_DISCONNECT_COMPRESSION_ERROR",
139 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
140 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
141 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
142 "SSH_DISCONNECT_CONNECTION_LOST",
143 "SSH_DISCONNECT_BY_APPLICATION",
144 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
145 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
146 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
147 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
150 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
151 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
152 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
153 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
155 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
158 * Various remote-bug flags.
160 #define BUG_CHOKES_ON_SSH1_IGNORE 1
161 #define BUG_SSH2_HMAC 2
162 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
163 #define BUG_CHOKES_ON_RSA 8
164 #define BUG_SSH2_RSA_PADDING 16
165 #define BUG_SSH2_DERIVEKEY 32
166 #define BUG_SSH2_REKEY 64
167 #define BUG_SSH2_PK_SESSIONID 128
169 #define translate(x) if (type == x) return #x
170 #define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
171 static char *ssh1_pkt_type(int type)
173 translate(SSH1_MSG_DISCONNECT);
174 translate(SSH1_SMSG_PUBLIC_KEY);
175 translate(SSH1_CMSG_SESSION_KEY);
176 translate(SSH1_CMSG_USER);
177 translate(SSH1_CMSG_AUTH_RSA);
178 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
179 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
180 translate(SSH1_CMSG_AUTH_PASSWORD);
181 translate(SSH1_CMSG_REQUEST_PTY);
182 translate(SSH1_CMSG_WINDOW_SIZE);
183 translate(SSH1_CMSG_EXEC_SHELL);
184 translate(SSH1_CMSG_EXEC_CMD);
185 translate(SSH1_SMSG_SUCCESS);
186 translate(SSH1_SMSG_FAILURE);
187 translate(SSH1_CMSG_STDIN_DATA);
188 translate(SSH1_SMSG_STDOUT_DATA);
189 translate(SSH1_SMSG_STDERR_DATA);
190 translate(SSH1_CMSG_EOF);
191 translate(SSH1_SMSG_EXIT_STATUS);
192 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
193 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
194 translate(SSH1_MSG_CHANNEL_DATA);
195 translate(SSH1_MSG_CHANNEL_CLOSE);
196 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
197 translate(SSH1_SMSG_X11_OPEN);
198 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
199 translate(SSH1_MSG_PORT_OPEN);
200 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
201 translate(SSH1_SMSG_AGENT_OPEN);
202 translate(SSH1_MSG_IGNORE);
203 translate(SSH1_CMSG_EXIT_CONFIRMATION);
204 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
205 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
206 translate(SSH1_MSG_DEBUG);
207 translate(SSH1_CMSG_REQUEST_COMPRESSION);
208 translate(SSH1_CMSG_AUTH_TIS);
209 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
210 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
211 translate(SSH1_CMSG_AUTH_CCARD);
212 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
213 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
216 static char *ssh2_pkt_type(int pkt_ctx, int type)
218 translate(SSH2_MSG_DISCONNECT);
219 translate(SSH2_MSG_IGNORE);
220 translate(SSH2_MSG_UNIMPLEMENTED);
221 translate(SSH2_MSG_DEBUG);
222 translate(SSH2_MSG_SERVICE_REQUEST);
223 translate(SSH2_MSG_SERVICE_ACCEPT);
224 translate(SSH2_MSG_KEXINIT);
225 translate(SSH2_MSG_NEWKEYS);
226 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
227 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
228 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
229 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
230 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
231 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
232 translate(SSH2_MSG_USERAUTH_REQUEST);
233 translate(SSH2_MSG_USERAUTH_FAILURE);
234 translate(SSH2_MSG_USERAUTH_SUCCESS);
235 translate(SSH2_MSG_USERAUTH_BANNER);
236 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
237 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
238 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
239 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
240 translate(SSH2_MSG_GLOBAL_REQUEST);
241 translate(SSH2_MSG_REQUEST_SUCCESS);
242 translate(SSH2_MSG_REQUEST_FAILURE);
243 translate(SSH2_MSG_CHANNEL_OPEN);
244 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
245 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
246 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
247 translate(SSH2_MSG_CHANNEL_DATA);
248 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
249 translate(SSH2_MSG_CHANNEL_EOF);
250 translate(SSH2_MSG_CHANNEL_CLOSE);
251 translate(SSH2_MSG_CHANNEL_REQUEST);
252 translate(SSH2_MSG_CHANNEL_SUCCESS);
253 translate(SSH2_MSG_CHANNEL_FAILURE);
259 /* Enumeration values for fields in SSH-1 packets */
261 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
262 /* These values are for communicating relevant semantics of
263 * fields to the packet logging code. */
264 PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA
268 * Coroutine mechanics for the sillier bits of the code. If these
269 * macros look impenetrable to you, you might find it helpful to
272 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
274 * which explains the theory behind these macros.
276 * In particular, if you are getting `case expression not constant'
277 * errors when building with MS Visual Studio, this is because MS's
278 * Edit and Continue debugging feature causes their compiler to
279 * violate ANSI C. To disable Edit and Continue debugging:
281 * - right-click ssh.c in the FileView
283 * - select the C/C++ tab and the General category
284 * - under `Debug info:', select anything _other_ than `Program
285 * Database for Edit and Continue'.
287 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
290 if (!ssh->t) ssh->t = snew(struct t); \
292 #define crFinish(z) } *crLine = 0; return (z); }
293 #define crFinishV } *crLine = 0; return; }
294 #define crReturn(z) \
296 *crLine =__LINE__; return (z); case __LINE__:;\
300 *crLine=__LINE__; return; case __LINE__:;\
302 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
303 #define crStopV do{ *crLine = 0; return; }while(0)
304 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
305 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
307 typedef struct ssh_tag *Ssh;
310 static struct Packet *ssh1_pkt_init(int pkt_type);
311 static struct Packet *ssh2_pkt_init(int pkt_type);
312 static void ssh_pkt_ensure(struct Packet *, int length);
313 static void ssh_pkt_adddata(struct Packet *, void *data, int len);
314 static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
315 static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
316 static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
317 static void ssh_pkt_addstring_start(struct Packet *);
318 static void ssh_pkt_addstring_str(struct Packet *, char *data);
319 static void ssh_pkt_addstring_data(struct Packet *, char *data, int len);
320 static void ssh_pkt_addstring(struct Packet *, char *data);
321 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
322 static void ssh1_pkt_addmp(struct Packet *, Bignum b);
323 static void ssh2_pkt_addmp(struct Packet *, Bignum b);
324 static int ssh2_pkt_construct(Ssh, struct Packet *);
325 static void ssh2_pkt_send(Ssh, struct Packet *);
326 static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
327 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
328 struct Packet *pktin);
329 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
330 struct Packet *pktin);
333 * Buffer management constants. There are several of these for
334 * various different purposes:
336 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
337 * on a local data stream before we throttle the whole SSH
338 * connection (in SSH-1 only). Throttling the whole connection is
339 * pretty drastic so we set this high in the hope it won't
342 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
343 * on the SSH connection itself before we defensively throttle
344 * _all_ local data streams. This is pretty drastic too (though
345 * thankfully unlikely in SSH-2 since the window mechanism should
346 * ensure that the server never has any need to throttle its end
347 * of the connection), so we set this high as well.
349 * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
353 #define SSH1_BUFFER_LIMIT 32768
354 #define SSH_MAX_BACKLOG 32768
355 #define OUR_V2_WINSIZE 16384
356 #define OUR_V2_MAXPKT 0x4000UL
358 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
360 static void *nullmac_make_context(void)
364 static void nullmac_free_context(void *handle)
367 static void nullmac_key(void *handle, unsigned char *key)
370 static void nullmac_generate(void *handle, unsigned char *blk, int len,
374 static int nullmac_verify(void *handle, unsigned char *blk, int len,
379 const static struct ssh_mac ssh_mac_none = {
380 nullmac_make_context, nullmac_free_context, nullmac_key,
381 nullmac_generate, nullmac_verify, "none", 0
383 const static struct ssh_mac *macs[] = {
384 &ssh_sha1, &ssh_md5, &ssh_mac_none
386 const static struct ssh_mac *buggymacs[] = {
387 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
390 static void *ssh_comp_none_init(void)
394 static void ssh_comp_none_cleanup(void *handle)
397 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
398 unsigned char **outblock, int *outlen)
402 static int ssh_comp_none_disable(void *handle)
406 const static struct ssh_compress ssh_comp_none = {
408 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
409 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
410 ssh_comp_none_disable, NULL
412 extern const struct ssh_compress ssh_zlib;
413 const static struct ssh_compress *compressions[] = {
414 &ssh_zlib, &ssh_comp_none
417 enum { /* channel types */
422 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
426 * 2-3-4 tree storing channels.
429 Ssh ssh; /* pointer back to main context */
430 unsigned remoteid, localid;
432 /* True if we opened this channel but server hasn't confirmed. */
435 * In SSH-1, this value contains four bits:
437 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
438 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
439 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
440 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
442 * A channel is completely finished with when all four bits are set.
446 struct ssh1_data_channel {
449 struct ssh2_data_channel {
451 unsigned remwindow, remmaxpkt;
456 struct ssh_agent_channel {
457 unsigned char *message;
458 unsigned char msglen[4];
459 unsigned lensofar, totallen;
461 struct ssh_x11_channel {
464 struct ssh_pfd_channel {
471 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
472 * use this structure in different ways, reflecting SSH-2's
473 * altogether saner approach to port forwarding.
475 * In SSH-1, you arrange a remote forwarding by sending the server
476 * the remote port number, and the local destination host:port.
477 * When a connection comes in, the server sends you back that
478 * host:port pair, and you connect to it. This is a ready-made
479 * security hole if you're not on the ball: a malicious server
480 * could send you back _any_ host:port pair, so if you trustingly
481 * connect to the address it gives you then you've just opened the
482 * entire inside of your corporate network just by connecting
483 * through it to a dodgy SSH server. Hence, we must store a list of
484 * host:port pairs we _are_ trying to forward to, and reject a
485 * connection request from the server if it's not in the list.
487 * In SSH-2, each side of the connection minds its own business and
488 * doesn't send unnecessary information to the other. You arrange a
489 * remote forwarding by sending the server just the remote port
490 * number. When a connection comes in, the server tells you which
491 * of its ports was connected to; and _you_ have to remember what
492 * local host:port pair went with that port number.
494 * Hence, in SSH-1 this structure is indexed by destination
495 * host:port pair, whereas in SSH-2 it is indexed by source port.
497 struct ssh_portfwd; /* forward declaration */
499 struct ssh_rportfwd {
500 unsigned sport, dport;
503 struct ssh_portfwd *pfrec;
505 #define free_rportfwd(pf) ( \
506 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
509 * Separately to the rportfwd tree (which is for looking up port
510 * open requests from the server), a tree of _these_ structures is
511 * used to keep track of all the currently open port forwardings,
512 * so that we can reconfigure in mid-session if the user requests
516 enum { DESTROY, KEEP, CREATE } status;
518 unsigned sport, dport;
521 struct ssh_rportfwd *remote;
525 #define free_portfwd(pf) ( \
526 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
527 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
530 long length; /* length of `data' actually used */
531 long forcepad; /* SSH-2: force padding to at least this length */
532 int type; /* only used for incoming packets */
533 unsigned long sequence; /* SSH-2 incoming sequence number */
534 unsigned char *data; /* allocated storage */
535 unsigned char *body; /* offset of payload within `data' */
536 long savedpos; /* temporary index into `data' (for strings) */
537 long maxlen; /* amount of storage allocated for `data' */
538 long encrypted_len; /* for SSH-2 total-size counting */
541 * State associated with packet logging
545 struct logblank_t *blanks;
548 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
549 struct Packet *pktin);
550 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
551 struct Packet *pktin);
552 static void ssh1_protocol_setup(Ssh ssh);
553 static void ssh2_protocol_setup(Ssh ssh);
554 static void ssh_size(void *handle, int width, int height);
555 static void ssh_special(void *handle, Telnet_Special);
556 static int ssh2_try_send(struct ssh_channel *c);
557 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
558 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
559 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
560 static int ssh_sendbuffer(void *handle);
561 static int ssh_do_close(Ssh ssh, int notify_exit);
562 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
563 static int ssh2_pkt_getbool(struct Packet *pkt);
564 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
565 static void ssh2_timer(void *ctx, long now);
566 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
567 struct Packet *pktin);
569 struct rdpkt1_state_tag {
570 long len, pad, biglen, to_read;
571 unsigned long realcrc, gotcrc;
575 struct Packet *pktin;
578 struct rdpkt2_state_tag {
579 long len, pad, payload, packetlen, maclen;
582 unsigned long incoming_sequence;
583 struct Packet *pktin;
586 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
587 typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
589 struct queued_handler;
590 struct queued_handler {
592 chandler_fn_t handler;
594 struct queued_handler *next;
598 const struct plug_function_table *fn;
599 /* the above field _must_ be first in the structure */
601 SHA_State exhash, exhashbase;
608 unsigned char session_key[32];
610 int v1_remote_protoflags;
611 int v1_local_protoflags;
612 int agentfwd_enabled;
615 const struct ssh_cipher *cipher;
618 const struct ssh2_cipher *cscipher, *sccipher;
619 void *cs_cipher_ctx, *sc_cipher_ctx;
620 const struct ssh_mac *csmac, *scmac;
621 void *cs_mac_ctx, *sc_mac_ctx;
622 const struct ssh_compress *cscomp, *sccomp;
623 void *cs_comp_ctx, *sc_comp_ctx;
624 const struct ssh_kex *kex;
625 const struct ssh_signkey *hostkey;
626 unsigned char v2_session_id[20];
632 int echoing, editing;
636 int ospeed, ispeed; /* temporaries */
637 int term_width, term_height;
639 tree234 *channels; /* indexed by local id */
640 struct ssh_channel *mainchan; /* primary session channel */
644 tree234 *rportfwds, *portfwds;
648 SSH_STATE_BEFORE_SIZE,
654 int size_needed, eof_needed;
656 struct Packet **queue;
657 int queuelen, queuesize;
659 unsigned char *deferred_send_data;
660 int deferred_len, deferred_size;
663 * Gross hack: pscp will try to start SFTP but fall back to
664 * scp1 if that fails. This variable is the means by which
665 * scp.c can reach into the SSH code and find out which one it
671 * Used for username and password input.
673 char *userpass_input_buffer;
674 int userpass_input_buflen;
675 int userpass_input_bufpos;
676 int userpass_input_echo;
683 int v1_throttle_count;
686 int v1_stdout_throttling;
687 unsigned long v2_outgoing_sequence;
689 int ssh1_rdpkt_crstate;
690 int ssh2_rdpkt_crstate;
691 int do_ssh_init_crstate;
692 int ssh_gotdata_crstate;
693 int do_ssh1_login_crstate;
694 int do_ssh1_connection_crstate;
695 int do_ssh2_transport_crstate;
696 int do_ssh2_authconn_crstate;
698 void *do_ssh_init_state;
699 void *do_ssh1_login_state;
700 void *do_ssh2_transport_state;
701 void *do_ssh2_authconn_state;
703 struct rdpkt1_state_tag rdpkt1_state;
704 struct rdpkt2_state_tag rdpkt2_state;
706 /* SSH-1 and SSH-2 use this for different things, but both use it */
707 int protocol_initial_phase_done;
709 void (*protocol) (Ssh ssh, void *vin, int inlen,
711 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
714 * We maintain a full _copy_ of a Config structure here, not
715 * merely a pointer to it. That way, when we're passed a new
716 * one for reconfiguration, we can check the differences and
717 * potentially reconfigure port forwardings etc in mid-session.
722 * Used to transfer data back from async callbacks.
724 void *agent_response;
725 int agent_response_len;
729 * The SSH connection can be set as `frozen', meaning we are
730 * not currently accepting incoming data from the network. This
731 * is slightly more serious than setting the _socket_ as
732 * frozen, because we may already have had data passed to us
733 * from the network which we need to delay processing until
734 * after the freeze is lifted, so we also need a bufchain to
738 bufchain queued_incoming_data;
741 * Dispatch table for packet types that we may have to deal
744 handler_fn_t packet_dispatch[256];
747 * Queues of one-off handler functions for success/failure
748 * indications from a request.
750 struct queued_handler *qhead, *qtail;
753 * This module deals with sending keepalives.
758 * Track incoming and outgoing data sizes and time, for
761 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
762 unsigned long max_data_size;
764 long next_rekey, last_rekey;
765 char *deferred_rekey_reason; /* points to STATIC string; don't free */
768 #define logevent(s) logevent(ssh->frontend, s)
770 /* logevent, only printf-formatted. */
771 static void logeventf(Ssh ssh, const char *fmt, ...)
777 buf = dupvprintf(fmt, ap);
783 #define bombout(msg) \
785 char *text = dupprintf msg; \
786 ssh_do_close(ssh, FALSE); \
788 connection_fatal(ssh->frontend, "%s", text); \
792 /* Functions to leave bits out of the SSH packet log file. */
794 static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
796 if (ssh->cfg.logomitpass)
797 pkt->logmode = blanktype;
800 static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
802 if (ssh->cfg.logomitdata)
803 pkt->logmode = blanktype;
806 static void end_log_omission(Ssh ssh, struct Packet *pkt)
808 pkt->logmode = PKTLOG_EMIT;
811 static int ssh_channelcmp(void *av, void *bv)
813 struct ssh_channel *a = (struct ssh_channel *) av;
814 struct ssh_channel *b = (struct ssh_channel *) bv;
815 if (a->localid < b->localid)
817 if (a->localid > b->localid)
821 static int ssh_channelfind(void *av, void *bv)
823 unsigned *a = (unsigned *) av;
824 struct ssh_channel *b = (struct ssh_channel *) bv;
832 static int ssh_rportcmp_ssh1(void *av, void *bv)
834 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
835 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
837 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
838 return i < 0 ? -1 : +1;
839 if (a->dport > b->dport)
841 if (a->dport < b->dport)
846 static int ssh_rportcmp_ssh2(void *av, void *bv)
848 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
849 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
851 if (a->sport > b->sport)
853 if (a->sport < b->sport)
859 * Special form of strcmp which can cope with NULL inputs. NULL is
860 * defined to sort before even the empty string.
862 static int nullstrcmp(const char *a, const char *b)
864 if (a == NULL && b == NULL)
873 static int ssh_portcmp(void *av, void *bv)
875 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
876 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
878 if (a->type > b->type)
880 if (a->type < b->type)
882 if (a->addressfamily > b->addressfamily)
884 if (a->addressfamily < b->addressfamily)
886 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
887 return i < 0 ? -1 : +1;
888 if (a->sport > b->sport)
890 if (a->sport < b->sport)
892 if (a->type != 'D') {
893 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
894 return i < 0 ? -1 : +1;
895 if (a->dport > b->dport)
897 if (a->dport < b->dport)
903 static int alloc_channel_id(Ssh ssh)
905 const unsigned CHANNEL_NUMBER_OFFSET = 256;
906 unsigned low, high, mid;
908 struct ssh_channel *c;
911 * First-fit allocation of channel numbers: always pick the
912 * lowest unused one. To do this, binary-search using the
913 * counted B-tree to find the largest channel ID which is in a
914 * contiguous sequence from the beginning. (Precisely
915 * everything in that sequence must have ID equal to its tree
916 * index plus CHANNEL_NUMBER_OFFSET.)
918 tsize = count234(ssh->channels);
922 while (high - low > 1) {
923 mid = (high + low) / 2;
924 c = index234(ssh->channels, mid);
925 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
926 low = mid; /* this one is fine */
928 high = mid; /* this one is past it */
931 * Now low points to either -1, or the tree index of the
932 * largest ID in the initial sequence.
935 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
936 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
938 return low + 1 + CHANNEL_NUMBER_OFFSET;
941 static void c_write(Ssh ssh, const char *buf, int len)
943 if ((flags & FLAG_STDERR)) {
945 for (i = 0; i < len; i++)
947 fputc(buf[i], stderr);
950 from_backend(ssh->frontend, 1, buf, len);
953 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
956 for (i = 0; i < len; i++) {
958 c_write(ssh, "\r\n", 2);
959 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
960 c_write(ssh, buf + i, 1);
964 static void c_write_str(Ssh ssh, const char *buf)
966 c_write(ssh, buf, strlen(buf));
969 static void ssh_free_packet(struct Packet *pkt)
974 static struct Packet *ssh_new_packet(void)
976 struct Packet *pkt = snew(struct Packet);
978 pkt->body = pkt->data = NULL;
980 pkt->logmode = PKTLOG_EMIT;
988 * Collect incoming data in the incoming packet buffer.
989 * Decipher and verify the packet when it is completely read.
990 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
991 * Update the *data and *datalen variables.
992 * Return a Packet structure when a packet is completed.
994 static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
996 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
998 crBegin(ssh->ssh1_rdpkt_crstate);
1000 st->pktin = ssh_new_packet();
1002 st->pktin->type = 0;
1003 st->pktin->length = 0;
1005 for (st->i = st->len = 0; st->i < 4; st->i++) {
1006 while ((*datalen) == 0)
1008 st->len = (st->len << 8) + **data;
1009 (*data)++, (*datalen)--;
1012 st->pad = 8 - (st->len % 8);
1013 st->biglen = st->len + st->pad;
1014 st->pktin->length = st->len - 5;
1016 if (st->biglen < 0) {
1017 bombout(("Extremely large packet length from server suggests"
1018 " data stream corruption"));
1019 ssh_free_packet(st->pktin);
1023 st->pktin->maxlen = st->biglen;
1024 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1026 st->to_read = st->biglen;
1027 st->p = st->pktin->data;
1028 while (st->to_read > 0) {
1029 st->chunk = st->to_read;
1030 while ((*datalen) == 0)
1032 if (st->chunk > (*datalen))
1033 st->chunk = (*datalen);
1034 memcpy(st->p, *data, st->chunk);
1036 *datalen -= st->chunk;
1038 st->to_read -= st->chunk;
1041 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1042 st->biglen, NULL)) {
1043 bombout(("Network attack (CRC compensation) detected!"));
1044 ssh_free_packet(st->pktin);
1049 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1051 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1052 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1053 if (st->gotcrc != st->realcrc) {
1054 bombout(("Incorrect CRC received on packet"));
1055 ssh_free_packet(st->pktin);
1059 st->pktin->body = st->pktin->data + st->pad + 1;
1060 st->pktin->savedpos = 0;
1062 if (ssh->v1_compressing) {
1063 unsigned char *decompblk;
1065 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1066 st->pktin->body - 1, st->pktin->length + 1,
1067 &decompblk, &decomplen)) {
1068 bombout(("Zlib decompression encountered invalid data"));
1069 ssh_free_packet(st->pktin);
1073 if (st->pktin->maxlen < st->pad + decomplen) {
1074 st->pktin->maxlen = st->pad + decomplen;
1075 st->pktin->data = sresize(st->pktin->data,
1076 st->pktin->maxlen + APIEXTRA,
1078 st->pktin->body = st->pktin->data + st->pad + 1;
1081 memcpy(st->pktin->body - 1, decompblk, decomplen);
1083 st->pktin->length = decomplen - 1;
1086 st->pktin->type = st->pktin->body[-1];
1089 * Log incoming packet, possibly omitting sensitive fields.
1093 struct logblank_t blank;
1094 if (ssh->cfg.logomitdata) {
1095 int do_blank = FALSE, blank_prefix = 0;
1096 /* "Session data" packets - omit the data field */
1097 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1098 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
1099 do_blank = TRUE; blank_prefix = 0;
1100 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
1101 do_blank = TRUE; blank_prefix = 4;
1104 blank.offset = blank_prefix;
1105 blank.len = st->pktin->length;
1106 blank.type = PKTLOG_OMIT;
1110 log_packet(ssh->logctx,
1111 PKT_INCOMING, st->pktin->type,
1112 ssh1_pkt_type(st->pktin->type),
1113 st->pktin->body, st->pktin->length,
1117 crFinish(st->pktin);
1120 static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1122 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1124 crBegin(ssh->ssh2_rdpkt_crstate);
1126 st->pktin = ssh_new_packet();
1128 st->pktin->type = 0;
1129 st->pktin->length = 0;
1131 st->cipherblk = ssh->sccipher->blksize;
1134 if (st->cipherblk < 8)
1137 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1140 * Acquire and decrypt the first block of the packet. This will
1141 * contain the length and padding details.
1143 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1144 while ((*datalen) == 0)
1146 st->pktin->data[st->i] = *(*data)++;
1151 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1152 st->pktin->data, st->cipherblk);
1155 * Now get the length and padding figures.
1157 st->len = GET_32BIT(st->pktin->data);
1158 st->pad = st->pktin->data[4];
1161 * _Completely_ silly lengths should be stomped on before they
1162 * do us any more damage.
1164 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
1165 bombout(("Incoming packet was garbled on decryption"));
1166 ssh_free_packet(st->pktin);
1171 * This enables us to deduce the payload length.
1173 st->payload = st->len - st->pad - 1;
1175 st->pktin->length = st->payload + 5;
1178 * So now we can work out the total packet length.
1180 st->packetlen = st->len + 4;
1181 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1184 * Allocate memory for the rest of the packet.
1186 st->pktin->maxlen = st->packetlen + st->maclen;
1187 st->pktin->data = sresize(st->pktin->data,
1188 st->pktin->maxlen + APIEXTRA,
1192 * Read and decrypt the remainder of the packet.
1194 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1196 while ((*datalen) == 0)
1198 st->pktin->data[st->i] = *(*data)++;
1201 /* Decrypt everything _except_ the MAC. */
1203 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1204 st->pktin->data + st->cipherblk,
1205 st->packetlen - st->cipherblk);
1207 st->pktin->encrypted_len = st->packetlen;
1213 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, st->len + 4,
1214 st->incoming_sequence)) {
1215 bombout(("Incorrect MAC received on packet"));
1216 ssh_free_packet(st->pktin);
1220 st->pktin->sequence = st->incoming_sequence++;
1223 * Decompress packet payload.
1226 unsigned char *newpayload;
1229 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1230 st->pktin->data + 5, st->pktin->length - 5,
1231 &newpayload, &newlen)) {
1232 if (st->pktin->maxlen < newlen + 5) {
1233 st->pktin->maxlen = newlen + 5;
1234 st->pktin->data = sresize(st->pktin->data,
1235 st->pktin->maxlen + APIEXTRA,
1238 st->pktin->length = 5 + newlen;
1239 memcpy(st->pktin->data + 5, newpayload, newlen);
1244 st->pktin->savedpos = 6;
1245 st->pktin->body = st->pktin->data;
1246 st->pktin->type = st->pktin->data[5];
1249 * Log incoming packet, possibly omitting sensitive fields.
1253 struct logblank_t blank;
1254 if (ssh->cfg.logomitdata) {
1255 int do_blank = FALSE, blank_prefix = 0;
1256 /* "Session data" packets - omit the data field */
1257 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
1258 do_blank = TRUE; blank_prefix = 4;
1259 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1260 do_blank = TRUE; blank_prefix = 8;
1263 blank.offset = blank_prefix;
1264 blank.len = (st->pktin->length-6) - blank_prefix;
1265 blank.type = PKTLOG_OMIT;
1269 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1270 ssh2_pkt_type(ssh->pkt_ctx, st->pktin->type),
1271 st->pktin->data+6, st->pktin->length-6,
1275 crFinish(st->pktin);
1278 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1280 int pad, biglen, i, pktoffs;
1284 * XXX various versions of SC (including 8.8.4) screw up the
1285 * register allocation in this function and use the same register
1286 * (D6) for len and as a temporary, with predictable results. The
1287 * following sledgehammer prevents this.
1294 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1295 ssh1_pkt_type(pkt->data[12]),
1296 pkt->body, pkt->length - (pkt->body - pkt->data),
1297 pkt->nblanks, pkt->blanks);
1298 sfree(pkt->blanks); pkt->blanks = NULL;
1301 if (ssh->v1_compressing) {
1302 unsigned char *compblk;
1304 zlib_compress_block(ssh->cs_comp_ctx,
1305 pkt->data + 12, pkt->length - 12,
1306 &compblk, &complen);
1307 memcpy(pkt->data + 12, compblk, complen);
1309 pkt->length = complen + 12;
1312 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1314 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
1315 pad = 8 - (len % 8);
1317 biglen = len + pad; /* len(padding+type+data+CRC) */
1319 for (i = pktoffs; i < 4+8; i++)
1320 pkt->data[i] = random_byte();
1321 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1322 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1323 PUT_32BIT(pkt->data + pktoffs, len);
1326 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1327 pkt->data + pktoffs + 4, biglen);
1329 if (offset_p) *offset_p = pktoffs;
1330 return biglen + 4; /* len(length+padding+type+data+CRC) */
1333 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1335 int len, backlog, offset;
1336 len = s_wrpkt_prepare(ssh, pkt, &offset);
1337 backlog = sk_write(ssh->s, (char *)pkt->data + offset, len);
1338 if (backlog > SSH_MAX_BACKLOG)
1339 ssh_throttle_all(ssh, 1, backlog);
1340 ssh_free_packet(pkt);
1343 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1346 len = s_wrpkt_prepare(ssh, pkt, &offset);
1347 if (ssh->deferred_len + len > ssh->deferred_size) {
1348 ssh->deferred_size = ssh->deferred_len + len + 128;
1349 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1353 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1354 pkt->data + offset, len);
1355 ssh->deferred_len += len;
1356 ssh_free_packet(pkt);
1360 * Construct a SSH-1 packet with the specified contents.
1361 * (This all-at-once interface used to be the only one, but now SSH-1
1362 * packets can also be constructed incrementally.)
1364 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
1370 pkt = ssh1_pkt_init(pkttype);
1372 while ((argtype = va_arg(ap, int)) != PKT_END) {
1373 unsigned char *argp, argchar;
1374 unsigned long argint;
1377 /* Actual fields in the packet */
1379 argint = va_arg(ap, int);
1380 ssh_pkt_adduint32(pkt, argint);
1383 argchar = (unsigned char) va_arg(ap, int);
1384 ssh_pkt_addbyte(pkt, argchar);
1387 argp = va_arg(ap, unsigned char *);
1388 arglen = va_arg(ap, int);
1389 ssh_pkt_adddata(pkt, argp, arglen);
1392 argp = va_arg(ap, unsigned char *);
1393 ssh_pkt_addstring(pkt, argp);
1396 bn = va_arg(ap, Bignum);
1397 ssh1_pkt_addmp(pkt, bn);
1399 /* Tokens for modifications to packet logging */
1401 dont_log_password(ssh, pkt, PKTLOG_BLANK);
1404 dont_log_data(ssh, pkt, PKTLOG_OMIT);
1407 end_log_omission(ssh, pkt);
1415 static void send_packet(Ssh ssh, int pkttype, ...)
1419 va_start(ap, pkttype);
1420 pkt = construct_packet(ssh, pkttype, ap);
1425 static void defer_packet(Ssh ssh, int pkttype, ...)
1429 va_start(ap, pkttype);
1430 pkt = construct_packet(ssh, pkttype, ap);
1432 s_wrpkt_defer(ssh, pkt);
1435 static int ssh_versioncmp(char *a, char *b)
1438 unsigned long av, bv;
1440 av = strtoul(a, &ae, 10);
1441 bv = strtoul(b, &be, 10);
1443 return (av < bv ? -1 : +1);
1448 av = strtoul(ae, &ae, 10);
1449 bv = strtoul(be, &be, 10);
1451 return (av < bv ? -1 : +1);
1456 * Utility routines for putting an SSH-protocol `string' and
1457 * `uint32' into a SHA state.
1459 static void sha_string(SHA_State * s, void *str, int len)
1461 unsigned char lenblk[4];
1462 PUT_32BIT(lenblk, len);
1463 SHA_Bytes(s, lenblk, 4);
1464 SHA_Bytes(s, str, len);
1467 static void sha_uint32(SHA_State * s, unsigned i)
1469 unsigned char intblk[4];
1470 PUT_32BIT(intblk, i);
1471 SHA_Bytes(s, intblk, 4);
1475 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
1477 static void ssh_pkt_ensure(struct Packet *pkt, int length)
1479 if (pkt->maxlen < length) {
1480 unsigned char *body = pkt->body;
1481 int offset = body ? pkt->data - body : 0;
1482 pkt->maxlen = length + 256;
1483 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
1484 if (body) pkt->body = pkt->data + offset;
1487 static void ssh_pkt_adddata(struct Packet *pkt, void *data, int len)
1489 if (pkt->logmode != PKTLOG_EMIT) {
1491 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1493 pkt->blanks[pkt->nblanks-1].offset = pkt->length -
1494 (pkt->body - pkt->data);
1495 pkt->blanks[pkt->nblanks-1].len = len;
1496 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1499 ssh_pkt_ensure(pkt, pkt->length);
1500 memcpy(pkt->data + pkt->length - len, data, len);
1502 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
1504 ssh_pkt_adddata(pkt, &byte, 1);
1506 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
1508 ssh_pkt_adddata(pkt, &value, 1);
1510 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
1513 PUT_32BIT(x, value);
1514 ssh_pkt_adddata(pkt, x, 4);
1516 static void ssh_pkt_addstring_start(struct Packet *pkt)
1518 ssh_pkt_adduint32(pkt, 0);
1519 pkt->savedpos = pkt->length;
1521 static void ssh_pkt_addstring_str(struct Packet *pkt, char *data)
1523 ssh_pkt_adddata(pkt, data, strlen(data));
1524 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1526 static void ssh_pkt_addstring_data(struct Packet *pkt, char *data, int len)
1528 ssh_pkt_adddata(pkt, data, len);
1529 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1531 static void ssh_pkt_addstring(struct Packet *pkt, char *data)
1533 ssh_pkt_addstring_start(pkt);
1534 ssh_pkt_addstring_str(pkt, data);
1536 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
1538 int len = ssh1_bignum_length(b);
1539 unsigned char *data = snewn(len, char);
1540 (void) ssh1_write_bignum(data, b);
1541 ssh_pkt_adddata(pkt, data, len);
1544 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1547 int i, n = (bignum_bitcount(b) + 7) / 8;
1548 p = snewn(n + 1, unsigned char);
1550 fatalbox("out of memory");
1552 for (i = 1; i <= n; i++)
1553 p[i] = bignum_byte(b, n - i);
1555 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1557 memmove(p, p + i, n + 1 - i);
1561 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
1565 p = ssh2_mpint_fmt(b, &len);
1566 ssh_pkt_addstring_start(pkt);
1567 ssh_pkt_addstring_data(pkt, (char *)p, len);
1571 static struct Packet *ssh1_pkt_init(int pkt_type)
1573 struct Packet *pkt = ssh_new_packet();
1574 pkt->length = 4 + 8; /* space for length + max padding */
1575 ssh_pkt_addbyte(pkt, pkt_type);
1576 pkt->body = pkt->data + pkt->length;
1580 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
1581 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
1582 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
1583 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
1584 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
1585 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
1586 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
1587 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
1588 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
1590 static struct Packet *ssh2_pkt_init(int pkt_type)
1592 struct Packet *pkt = ssh_new_packet();
1595 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
1596 pkt->body = pkt->data + pkt->length;
1601 * Construct an SSH-2 final-form packet: compress it, encrypt it,
1602 * put the MAC on it. Final packet, ready to be sent, is stored in
1603 * pkt->data. Total length is returned.
1605 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
1607 int cipherblk, maclen, padding, i;
1610 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1611 ssh2_pkt_type(ssh->pkt_ctx, pkt->data[5]),
1612 pkt->body, pkt->length - (pkt->body - pkt->data),
1613 pkt->nblanks, pkt->blanks);
1614 sfree(pkt->blanks); pkt->blanks = NULL;
1618 * Compress packet payload.
1621 unsigned char *newpayload;
1624 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1626 &newpayload, &newlen)) {
1628 ssh2_pkt_adddata(pkt, newpayload, newlen);
1634 * Add padding. At least four bytes, and must also bring total
1635 * length (minus MAC) up to a multiple of the block size.
1636 * If pkt->forcepad is set, make sure the packet is at least that size
1639 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1640 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1642 if (pkt->length + padding < pkt->forcepad)
1643 padding = pkt->forcepad - pkt->length;
1645 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
1646 assert(padding <= 255);
1647 maclen = ssh->csmac ? ssh->csmac->len : 0;
1648 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1649 pkt->data[4] = padding;
1650 for (i = 0; i < padding; i++)
1651 pkt->data[pkt->length + i] = random_byte();
1652 PUT_32BIT(pkt->data, pkt->length + padding - 4);
1654 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1655 pkt->length + padding,
1656 ssh->v2_outgoing_sequence);
1657 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1660 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1661 pkt->data, pkt->length + padding);
1663 pkt->encrypted_len = pkt->length + padding;
1665 /* Ready-to-send packet starts at pkt->data. We return length. */
1666 return pkt->length + padding + maclen;
1670 * Routines called from the main SSH code to send packets. There
1671 * are quite a few of these, because we have two separate
1672 * mechanisms for delaying the sending of packets:
1674 * - In order to send an IGNORE message and a password message in
1675 * a single fixed-length blob, we require the ability to
1676 * concatenate the encrypted forms of those two packets _into_ a
1677 * single blob and then pass it to our <network.h> transport
1678 * layer in one go. Hence, there's a deferment mechanism which
1679 * works after packet encryption.
1681 * - In order to avoid sending any connection-layer messages
1682 * during repeat key exchange, we have to queue up any such
1683 * outgoing messages _before_ they are encrypted (and in
1684 * particular before they're allocated sequence numbers), and
1685 * then send them once we've finished.
1687 * I call these mechanisms `defer' and `queue' respectively, so as
1688 * to distinguish them reasonably easily.
1690 * The functions send_noqueue() and defer_noqueue() free the packet
1691 * structure they are passed. Every outgoing packet goes through
1692 * precisely one of these functions in its life; packets passed to
1693 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
1694 * these or get queued, and then when the queue is later emptied
1695 * the packets are all passed to defer_noqueue().
1699 * Send an SSH-2 packet immediately, without queuing or deferring.
1701 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
1705 len = ssh2_pkt_construct(ssh, pkt);
1706 backlog = sk_write(ssh->s, (char *)pkt->data, len);
1707 if (backlog > SSH_MAX_BACKLOG)
1708 ssh_throttle_all(ssh, 1, backlog);
1710 ssh->outgoing_data_size += pkt->encrypted_len;
1711 if (!ssh->kex_in_progress &&
1712 ssh->max_data_size != 0 &&
1713 ssh->outgoing_data_size > ssh->max_data_size)
1714 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
1716 ssh_free_packet(pkt);
1720 * Defer an SSH-2 packet.
1722 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt)
1724 int len = ssh2_pkt_construct(ssh, pkt);
1725 if (ssh->deferred_len + len > ssh->deferred_size) {
1726 ssh->deferred_size = ssh->deferred_len + len + 128;
1727 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1731 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
1732 ssh->deferred_len += len;
1733 ssh->deferred_data_size += pkt->encrypted_len;
1734 ssh_free_packet(pkt);
1738 * Queue an SSH-2 packet.
1740 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
1742 assert(ssh->queueing);
1744 if (ssh->queuelen >= ssh->queuesize) {
1745 ssh->queuesize = ssh->queuelen + 32;
1746 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
1749 ssh->queue[ssh->queuelen++] = pkt;
1753 * Either queue or send a packet, depending on whether queueing is
1756 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
1759 ssh2_pkt_queue(ssh, pkt);
1761 ssh2_pkt_send_noqueue(ssh, pkt);
1766 * Either queue or defer a packet, depending on whether queueing is
1769 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
1772 ssh2_pkt_queue(ssh, pkt);
1774 ssh2_pkt_defer_noqueue(ssh, pkt);
1779 * Send the whole deferred data block constructed by
1780 * ssh2_pkt_defer() or SSH-1's defer_packet().
1782 * The expected use of the defer mechanism is that you call
1783 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
1784 * not currently queueing, this simply sets up deferred_send_data
1785 * and then sends it. If we _are_ currently queueing, the calls to
1786 * ssh2_pkt_defer() put the deferred packets on to the queue
1787 * instead, and therefore ssh_pkt_defersend() has no deferred data
1788 * to send. Hence, there's no need to make it conditional on
1791 static void ssh_pkt_defersend(Ssh ssh)
1794 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1796 ssh->deferred_len = ssh->deferred_size = 0;
1797 sfree(ssh->deferred_send_data);
1798 ssh->deferred_send_data = NULL;
1799 if (backlog > SSH_MAX_BACKLOG)
1800 ssh_throttle_all(ssh, 1, backlog);
1802 ssh->outgoing_data_size += ssh->deferred_data_size;
1803 if (!ssh->kex_in_progress &&
1804 ssh->max_data_size != 0 &&
1805 ssh->outgoing_data_size > ssh->max_data_size)
1806 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
1807 ssh->deferred_data_size = 0;
1811 * Send all queued SSH-2 packets. We send them by means of
1812 * ssh2_pkt_defer_noqueue(), in case they included a pair of
1813 * packets that needed to be lumped together.
1815 static void ssh2_pkt_queuesend(Ssh ssh)
1819 assert(!ssh->queueing);
1821 for (i = 0; i < ssh->queuelen; i++)
1822 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i]);
1825 ssh_pkt_defersend(ssh);
1829 void bndebug(char *string, Bignum b)
1833 p = ssh2_mpint_fmt(b, &len);
1834 debug(("%s", string));
1835 for (i = 0; i < len; i++)
1836 debug((" %02x", p[i]));
1842 static void sha_mpint(SHA_State * s, Bignum b)
1846 p = ssh2_mpint_fmt(b, &len);
1847 sha_string(s, p, len);
1852 * Packet decode functions for both SSH-1 and SSH-2.
1854 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
1856 unsigned long value;
1857 if (pkt->length - pkt->savedpos < 4)
1858 return 0; /* arrgh, no way to decline (FIXME?) */
1859 value = GET_32BIT(pkt->body + pkt->savedpos);
1863 static int ssh2_pkt_getbool(struct Packet *pkt)
1865 unsigned long value;
1866 if (pkt->length - pkt->savedpos < 1)
1867 return 0; /* arrgh, no way to decline (FIXME?) */
1868 value = pkt->body[pkt->savedpos] != 0;
1872 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
1877 if (pkt->length - pkt->savedpos < 4)
1879 len = GET_32BIT(pkt->body + pkt->savedpos);
1884 if (pkt->length - pkt->savedpos < *length)
1886 *p = (char *)(pkt->body + pkt->savedpos);
1887 pkt->savedpos += *length;
1889 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
1891 if (pkt->length - pkt->savedpos < length)
1893 pkt->savedpos += length;
1894 return pkt->body + (pkt->savedpos - length);
1896 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
1897 unsigned char **keystr)
1901 j = makekey(pkt->body + pkt->savedpos,
1902 pkt->length - pkt->savedpos,
1909 assert(pkt->savedpos < pkt->length);
1913 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
1918 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
1919 pkt->length - pkt->savedpos, &b);
1927 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
1933 ssh_pkt_getstring(pkt, &p, &length);
1938 b = bignum_from_bytes((unsigned char *)p, length);
1943 * Helper function to add an SSH-2 signature blob to a packet.
1944 * Expects to be shown the public key blob as well as the signature
1945 * blob. Normally works just like ssh2_pkt_addstring, but will
1946 * fiddle with the signature packet if necessary for
1947 * BUG_SSH2_RSA_PADDING.
1949 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
1950 void *pkblob_v, int pkblob_len,
1951 void *sigblob_v, int sigblob_len)
1953 unsigned char *pkblob = (unsigned char *)pkblob_v;
1954 unsigned char *sigblob = (unsigned char *)sigblob_v;
1956 /* dmemdump(pkblob, pkblob_len); */
1957 /* dmemdump(sigblob, sigblob_len); */
1960 * See if this is in fact an ssh-rsa signature and a buggy
1961 * server; otherwise we can just do this the easy way.
1963 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1964 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1965 int pos, len, siglen;
1968 * Find the byte length of the modulus.
1971 pos = 4+7; /* skip over "ssh-rsa" */
1972 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1973 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1974 pos += 4; /* find modulus itself */
1975 while (len > 0 && pkblob[pos] == 0)
1977 /* debug(("modulus length is %d\n", len)); */
1980 * Now find the signature integer.
1982 pos = 4+7; /* skip over "ssh-rsa" */
1983 siglen = GET_32BIT(sigblob+pos);
1984 /* debug(("signature length is %d\n", siglen)); */
1986 if (len != siglen) {
1987 unsigned char newlen[4];
1988 ssh2_pkt_addstring_start(pkt);
1989 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
1990 /* dmemdump(sigblob, pos); */
1991 pos += 4; /* point to start of actual sig */
1992 PUT_32BIT(newlen, len);
1993 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
1994 /* dmemdump(newlen, 4); */
1996 while (len-- > siglen) {
1997 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
1998 /* dmemdump(newlen, 1); */
2000 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2001 /* dmemdump(sigblob+pos, siglen); */
2005 /* Otherwise fall through and do it the easy way. */
2008 ssh2_pkt_addstring_start(pkt);
2009 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2013 * Examine the remote side's version string and compare it against
2014 * a list of known buggy implementations.
2016 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2018 char *imp; /* pointer to implementation part */
2020 imp += strcspn(imp, "-");
2022 imp += strcspn(imp, "-");
2025 ssh->remote_bugs = 0;
2027 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
2028 (ssh->cfg.sshbug_ignore1 == AUTO &&
2029 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2030 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2031 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2032 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2034 * These versions don't support SSH1_MSG_IGNORE, so we have
2035 * to use a different defence against password length
2038 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2039 logevent("We believe remote version has SSH-1 ignore bug");
2042 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
2043 (ssh->cfg.sshbug_plainpw1 == AUTO &&
2044 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2046 * These versions need a plain password sent; they can't
2047 * handle having a null and a random length of data after
2050 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2051 logevent("We believe remote version needs a plain SSH-1 password");
2054 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
2055 (ssh->cfg.sshbug_rsa1 == AUTO &&
2056 (!strcmp(imp, "Cisco-1.25")))) {
2058 * These versions apparently have no clue whatever about
2059 * RSA authentication and will panic and die if they see
2060 * an AUTH_RSA message.
2062 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2063 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2066 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2067 (ssh->cfg.sshbug_hmac2 == AUTO &&
2068 !wc_match("* VShell", imp) &&
2069 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2070 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2071 wc_match("2.1 *", imp)))) {
2073 * These versions have the HMAC bug.
2075 ssh->remote_bugs |= BUG_SSH2_HMAC;
2076 logevent("We believe remote version has SSH-2 HMAC bug");
2079 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2080 (ssh->cfg.sshbug_derivekey2 == AUTO &&
2081 !wc_match("* VShell", imp) &&
2082 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2084 * These versions have the key-derivation bug (failing to
2085 * include the literal shared secret in the hashes that
2086 * generate the keys).
2088 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2089 logevent("We believe remote version has SSH-2 key-derivation bug");
2092 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2093 (ssh->cfg.sshbug_rsapad2 == AUTO &&
2094 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2095 wc_match("OpenSSH_3.[0-2]*", imp)))) {
2097 * These versions have the SSH-2 RSA padding bug.
2099 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2100 logevent("We believe remote version has SSH-2 RSA padding bug");
2103 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2104 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2105 wc_match("OpenSSH_2.[0-2]*", imp))) {
2107 * These versions have the SSH-2 session-ID bug in
2108 * public-key authentication.
2110 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2111 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2114 if (ssh->cfg.sshbug_rekey2 == FORCE_ON ||
2115 (ssh->cfg.sshbug_rekey2 == AUTO &&
2116 (wc_match("OpenSSH_2.[0-4]*", imp) ||
2117 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2118 wc_match("Sun_SSH_1.0", imp) ||
2119 wc_match("Sun_SSH_1.0.1", imp)))) {
2121 * These versions have the SSH-2 rekey bug.
2123 ssh->remote_bugs |= BUG_SSH2_REKEY;
2124 logevent("We believe remote version has SSH-2 rekey bug");
2129 * The `software version' part of an SSH version string is required
2130 * to contain no spaces or minus signs.
2132 static void ssh_fix_verstring(char *str)
2134 /* Eat "SSH-<protoversion>-". */
2135 assert(*str == 'S'); str++;
2136 assert(*str == 'S'); str++;
2137 assert(*str == 'H'); str++;
2138 assert(*str == '-'); str++;
2139 while (*str && *str != '-') str++;
2140 assert(*str == '-'); str++;
2142 /* Convert minus signs and spaces in the remaining string into
2145 if (*str == '-' || *str == ' ')
2151 static int do_ssh_init(Ssh ssh, unsigned char c)
2153 struct do_ssh_init_state {
2161 crState(do_ssh_init_state);
2163 crBegin(ssh->do_ssh_init_crstate);
2165 /* Search for the string "SSH-" in the input. */
2168 static const int transS[] = { 1, 2, 2, 1 };
2169 static const int transH[] = { 0, 0, 3, 0 };
2170 static const int transminus[] = { 0, 0, 0, -1 };
2172 s->i = transS[s->i];
2174 s->i = transH[s->i];
2176 s->i = transminus[s->i];
2181 crReturn(1); /* get another character */
2185 s->vstring = snewn(s->vstrsize, char);
2186 strcpy(s->vstring, "SSH-");
2190 crReturn(1); /* get another char */
2191 if (s->vslen >= s->vstrsize - 1) {
2193 s->vstring = sresize(s->vstring, s->vstrsize, char);
2195 s->vstring[s->vslen++] = c;
2198 s->version[s->i] = '\0';
2200 } else if (s->i < sizeof(s->version) - 1)
2201 s->version[s->i++] = c;
2202 } else if (c == '\012')
2206 ssh->agentfwd_enabled = FALSE;
2207 ssh->rdpkt2_state.incoming_sequence = 0;
2209 s->vstring[s->vslen] = 0;
2210 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2211 logeventf(ssh, "Server version: %s", s->vstring);
2212 ssh_detect_bugs(ssh, s->vstring);
2215 * Decide which SSH protocol version to support.
2218 /* Anything strictly below "2.0" means protocol 1 is supported. */
2219 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2220 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2221 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2223 if (ssh->cfg.sshprot == 0 && !s->proto1) {
2224 bombout(("SSH protocol version 1 required by user but not provided by server"));
2227 if (ssh->cfg.sshprot == 3 && !s->proto2) {
2228 bombout(("SSH protocol version 2 required by user but not provided by server"));
2235 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2237 * Construct a v2 version string.
2239 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2243 * Construct a v1 version string.
2245 verstring = dupprintf("SSH-%s-%s\012",
2246 (ssh_versioncmp(s->version, "1.5") <= 0 ?
2247 s->version : "1.5"),
2252 ssh_fix_verstring(verstring);
2254 if (ssh->version == 2) {
2256 * Hash our version string and their version string.
2258 SHA_Init(&ssh->exhashbase);
2259 sha_string(&ssh->exhashbase, verstring,
2260 strcspn(verstring, "\015\012"));
2261 sha_string(&ssh->exhashbase, s->vstring,
2262 strcspn(s->vstring, "\015\012"));
2265 * Initialise SSH-2 protocol.
2267 ssh->protocol = ssh2_protocol;
2268 ssh2_protocol_setup(ssh);
2269 ssh->s_rdpkt = ssh2_rdpkt;
2272 * Initialise SSH-1 protocol.
2274 ssh->protocol = ssh1_protocol;
2275 ssh1_protocol_setup(ssh);
2276 ssh->s_rdpkt = ssh1_rdpkt;
2278 logeventf(ssh, "We claim version: %.*s",
2279 strcspn(verstring, "\015\012"), verstring);
2280 sk_write(ssh->s, verstring, strlen(verstring));
2284 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2286 update_specials_menu(ssh->frontend);
2287 ssh->state = SSH_STATE_BEFORE_SIZE;
2288 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
2295 static void ssh_process_incoming_data(Ssh ssh,
2296 unsigned char **data, int *datalen)
2298 struct Packet *pktin = ssh->s_rdpkt(ssh, data, datalen);
2300 ssh->protocol(ssh, NULL, 0, pktin);
2301 ssh_free_packet(pktin);
2305 static void ssh_queue_incoming_data(Ssh ssh,
2306 unsigned char **data, int *datalen)
2308 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
2313 static void ssh_process_queued_incoming_data(Ssh ssh)
2316 unsigned char *data;
2319 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
2320 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
2324 while (!ssh->frozen && len > 0)
2325 ssh_process_incoming_data(ssh, &data, &len);
2328 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
2332 static void ssh_set_frozen(Ssh ssh, int frozen)
2335 sk_set_frozen(ssh->s, frozen);
2336 ssh->frozen = frozen;
2339 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2341 crBegin(ssh->ssh_gotdata_crstate);
2344 * To begin with, feed the characters one by one to the
2345 * protocol initialisation / selection function do_ssh_init().
2346 * When that returns 0, we're done with the initial greeting
2347 * exchange and can move on to packet discipline.
2350 int ret; /* need not be kept across crReturn */
2352 crReturnV; /* more data please */
2353 ret = do_ssh_init(ssh, *data);
2361 * We emerge from that loop when the initial negotiation is
2362 * over and we have selected an s_rdpkt function. Now pass
2363 * everything to s_rdpkt, and then pass the resulting packets
2364 * to the proper protocol handler.
2370 * Process queued data if there is any.
2372 ssh_process_queued_incoming_data(ssh);
2375 while (datalen > 0) {
2377 ssh_queue_incoming_data(ssh, &data, &datalen);
2379 ssh_process_incoming_data(ssh, &data, &datalen);
2381 if (ssh->state == SSH_STATE_CLOSED)
2389 static int ssh_do_close(Ssh ssh, int notify_exit)
2392 struct ssh_channel *c;
2394 ssh->state = SSH_STATE_CLOSED;
2395 expire_timer_context(ssh);
2400 notify_remote_exit(ssh->frontend);
2405 * Now we must shut down any port- and X-forwarded channels going
2406 * through this connection.
2408 if (ssh->channels) {
2409 while (NULL != (c = index234(ssh->channels, 0))) {
2412 x11_close(c->u.x11.s);
2415 pfd_close(c->u.pfd.s);
2418 del234(ssh->channels, c); /* moving next one to index 0 */
2419 if (ssh->version == 2)
2420 bufchain_clear(&c->v.v2.outbuffer);
2425 * Go through port-forwardings, and close any associated
2426 * listening sockets.
2428 if (ssh->portfwds) {
2429 struct ssh_portfwd *pf;
2430 while (NULL != (pf = index234(ssh->portfwds, 0))) {
2431 /* Dispose of any listening socket. */
2433 pfd_terminate(pf->local);
2434 del234(ssh->portfwds, pf); /* moving next one to index 0 */
2442 static void ssh_log(Plug plug, int type, SockAddr addr, int port,
2443 const char *error_msg, int error_code)
2445 Ssh ssh = (Ssh) plug;
2446 char addrbuf[256], *msg;
2448 sk_getaddr(addr, addrbuf, lenof(addrbuf));
2451 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
2453 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
2459 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2462 Ssh ssh = (Ssh) plug;
2463 int need_notify = ssh_do_close(ssh, FALSE);
2465 if (!error_msg && !ssh->close_expected) {
2466 error_msg = "Server unexpectedly closed network connection";
2470 notify_remote_exit(ssh->frontend);
2473 /* A socket error has occurred. */
2474 logevent(error_msg);
2475 connection_fatal(ssh->frontend, "%s", error_msg);
2477 logevent("Server closed network connection");
2482 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2484 Ssh ssh = (Ssh) plug;
2485 ssh_gotdata(ssh, (unsigned char *)data, len);
2486 if (ssh->state == SSH_STATE_CLOSED) {
2487 ssh_do_close(ssh, TRUE);
2493 static void ssh_sent(Plug plug, int bufsize)
2495 Ssh ssh = (Ssh) plug;
2497 * If the send backlog on the SSH socket itself clears, we
2498 * should unthrottle the whole world if it was throttled.
2500 if (bufsize < SSH_MAX_BACKLOG)
2501 ssh_throttle_all(ssh, 0, bufsize);
2505 * Connect to specified host and port.
2506 * Returns an error message, or NULL on success.
2507 * Also places the canonical host name into `realhost'. It must be
2508 * freed by the caller.
2510 static const char *connect_to_host(Ssh ssh, char *host, int port,
2511 char **realhost, int nodelay, int keepalive)
2513 static const struct plug_function_table fn_table = {
2524 ssh->savedhost = snewn(1 + strlen(host), char);
2525 if (!ssh->savedhost)
2526 fatalbox("Out of memory");
2527 strcpy(ssh->savedhost, host);
2530 port = 22; /* default ssh port */
2531 ssh->savedport = port;
2536 logeventf(ssh, "Looking up host \"%s\"%s", host,
2537 (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
2538 (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
2539 addr = name_lookup(host, port, realhost, &ssh->cfg,
2540 ssh->cfg.addressfamily);
2541 if ((err = sk_addr_error(addr)) != NULL) {
2549 ssh->fn = &fn_table;
2550 ssh->s = new_connection(addr, *realhost, port,
2551 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
2552 if ((err = sk_socket_error(ssh->s)) != NULL) {
2554 notify_remote_exit(ssh->frontend);
2562 * Throttle or unthrottle the SSH connection.
2564 static void ssh1_throttle(Ssh ssh, int adjust)
2566 int old_count = ssh->v1_throttle_count;
2567 ssh->v1_throttle_count += adjust;
2568 assert(ssh->v1_throttle_count >= 0);
2569 if (ssh->v1_throttle_count && !old_count) {
2570 ssh_set_frozen(ssh, 1);
2571 } else if (!ssh->v1_throttle_count && old_count) {
2572 ssh_set_frozen(ssh, 0);
2577 * Throttle or unthrottle _all_ local data streams (for when sends
2578 * on the SSH connection itself back up).
2580 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2583 struct ssh_channel *c;
2585 if (enable == ssh->throttled_all)
2587 ssh->throttled_all = enable;
2588 ssh->overall_bufsize = bufsize;
2591 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2593 case CHAN_MAINSESSION:
2595 * This is treated separately, outside the switch.
2599 x11_override_throttle(c->u.x11.s, enable);
2602 /* Agent channels require no buffer management. */
2605 pfd_override_throttle(c->u.pfd.s, enable);
2612 * Username and password input, abstracted off into routines
2613 * reusable in several places - even between SSH-1 and SSH-2.
2616 /* Set up a username or password input loop on a given buffer. */
2617 static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2619 ssh->userpass_input_buffer = buffer;
2620 ssh->userpass_input_buflen = buflen;
2621 ssh->userpass_input_bufpos = 0;
2622 ssh->userpass_input_echo = echo;
2626 * Process some terminal data in the course of username/password
2627 * input. Returns >0 for success (line of input returned in
2628 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2629 * for inconclusive (keep waiting for more input please).
2631 static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2636 switch (c = *in++) {
2639 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2640 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2645 if (ssh->userpass_input_bufpos > 0) {
2646 if (ssh->userpass_input_echo)
2647 c_write_str(ssh, "\b \b");
2648 ssh->userpass_input_bufpos--;
2653 while (ssh->userpass_input_bufpos > 0) {
2654 if (ssh->userpass_input_echo)
2655 c_write_str(ssh, "\b \b");
2656 ssh->userpass_input_bufpos--;
2665 * This simplistic check for printability is disabled
2666 * when we're doing password input, because some people
2667 * have control characters in their passwords.o
2669 if ((!ssh->userpass_input_echo ||
2670 (c >= ' ' && c <= '~') ||
2671 ((unsigned char) c >= 160))
2672 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2673 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2674 if (ssh->userpass_input_echo)
2675 c_write(ssh, &c, 1);
2683 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
2685 Ssh ssh = (Ssh) sshv;
2687 ssh->agent_response = reply;
2688 ssh->agent_response_len = replylen;
2690 if (ssh->version == 1)
2691 do_ssh1_login(ssh, NULL, -1, NULL);
2693 do_ssh2_authconn(ssh, NULL, -1, NULL);
2696 static void ssh_dialog_callback(void *sshv, int ret)
2698 Ssh ssh = (Ssh) sshv;
2700 ssh->user_response = ret;
2702 if (ssh->version == 1)
2703 do_ssh1_login(ssh, NULL, -1, NULL);
2705 do_ssh2_transport(ssh, NULL, -1, NULL);
2708 * This may have unfrozen the SSH connection, so do a
2711 ssh_process_queued_incoming_data(ssh);
2714 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
2716 struct ssh_channel *c = (struct ssh_channel *)cv;
2718 void *sentreply = reply;
2721 /* Fake SSH_AGENT_FAILURE. */
2722 sentreply = "\0\0\0\1\5";
2725 if (ssh->version == 2) {
2726 ssh2_add_channel_data(c, sentreply, replylen);
2729 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2730 PKT_INT, c->remoteid,
2733 PKT_DATA, sentreply, replylen,
2742 * Handle the key exchange and user authentication phases.
2744 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2745 struct Packet *pktin)
2748 unsigned char cookie[8], *ptr;
2749 struct RSAKey servkey, hostkey;
2750 struct MD5Context md5c;
2751 struct do_ssh1_login_state {
2753 unsigned char *rsabuf, *keystr1, *keystr2;
2754 unsigned long supported_ciphers_mask, supported_auths_mask;
2755 int tried_publickey, tried_agent;
2756 int tis_auth_refused, ccard_auth_refused;
2757 unsigned char session_id[16];
2760 void *publickey_blob;
2761 int publickey_bloblen;
2767 unsigned char request[5], *response, *p;
2777 crState(do_ssh1_login_state);
2779 crBegin(ssh->do_ssh1_login_crstate);
2784 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
2785 bombout(("Public key packet not received"));
2789 logevent("Received public keys");
2791 ptr = ssh_pkt_getdata(pktin, 8);
2793 bombout(("SSH-1 public key packet stopped before random cookie"));
2796 memcpy(cookie, ptr, 8);
2798 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2799 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
2800 bombout(("Failed to read SSH-1 public keys from public key packet"));
2805 * Log the host key fingerprint.
2809 logevent("Host key fingerprint is:");
2810 strcpy(logmsg, " ");
2811 hostkey.comment = NULL;
2812 rsa_fingerprint(logmsg + strlen(logmsg),
2813 sizeof(logmsg) - strlen(logmsg), &hostkey);
2817 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2818 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2819 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
2821 ssh->v1_local_protoflags =
2822 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2823 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2826 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2827 MD5Update(&md5c, s->keystr1, servkey.bytes);
2828 MD5Update(&md5c, cookie, 8);
2829 MD5Final(s->session_id, &md5c);
2831 for (i = 0; i < 32; i++)
2832 ssh->session_key[i] = random_byte();
2835 * Verify that the `bits' and `bytes' parameters match.
2837 if (hostkey.bits > hostkey.bytes * 8 ||
2838 servkey.bits > servkey.bytes * 8) {
2839 bombout(("SSH-1 public keys were badly formatted"));
2843 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2845 s->rsabuf = snewn(s->len, unsigned char);
2847 fatalbox("Out of memory");
2850 * Verify the host key.
2854 * First format the key into a string.
2856 int len = rsastr_len(&hostkey);
2857 char fingerprint[100];
2858 char *keystr = snewn(len, char);
2860 fatalbox("Out of memory");
2861 rsastr_fmt(keystr, &hostkey);
2862 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2864 ssh_set_frozen(ssh, 1);
2865 s->dlgret = verify_ssh_host_key(ssh->frontend,
2866 ssh->savedhost, ssh->savedport,
2867 "rsa", keystr, fingerprint,
2868 ssh_dialog_callback, ssh);
2870 if (s->dlgret < 0) {
2874 bombout(("Unexpected data from server while waiting"
2875 " for user host key response"));
2878 } while (pktin || inlen > 0);
2879 s->dlgret = ssh->user_response;
2881 ssh_set_frozen(ssh, 0);
2883 if (s->dlgret == 0) {
2884 ssh->close_expected = TRUE;
2885 ssh_closing((Plug)ssh, NULL, 0, 0);
2890 for (i = 0; i < 32; i++) {
2891 s->rsabuf[i] = ssh->session_key[i];
2893 s->rsabuf[i] ^= s->session_id[i];
2896 if (hostkey.bytes > servkey.bytes) {
2897 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2899 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2901 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
2903 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2906 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
2910 logevent("Encrypted session key");
2913 int cipher_chosen = 0, warn = 0;
2914 char *cipher_string = NULL;
2916 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2917 int next_cipher = ssh->cfg.ssh_cipherlist[i];
2918 if (next_cipher == CIPHER_WARN) {
2919 /* If/when we choose a cipher, warn about it */
2921 } else if (next_cipher == CIPHER_AES) {
2922 /* XXX Probably don't need to mention this. */
2923 logevent("AES not supported in SSH-1, skipping");
2925 switch (next_cipher) {
2926 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
2927 cipher_string = "3DES"; break;
2928 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
2929 cipher_string = "Blowfish"; break;
2930 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
2931 cipher_string = "single-DES"; break;
2933 if (s->supported_ciphers_mask & (1 << s->cipher_type))
2937 if (!cipher_chosen) {
2938 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2939 bombout(("Server violates SSH-1 protocol by not "
2940 "supporting 3DES encryption"));
2942 /* shouldn't happen */
2943 bombout(("No supported ciphers found"));
2947 /* Warn about chosen cipher if necessary. */
2949 ssh_set_frozen(ssh, 1);
2950 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
2951 ssh_dialog_callback, ssh);
2952 if (s->dlgret < 0) {
2956 bombout(("Unexpected data from server while waiting"
2957 " for user response"));
2960 } while (pktin || inlen > 0);
2961 s->dlgret = ssh->user_response;
2963 ssh_set_frozen(ssh, 0);
2964 if (s->dlgret == 0) {
2965 ssh->close_expected = TRUE;
2966 ssh_closing((Plug)ssh, NULL, 0, 0);
2972 switch (s->cipher_type) {
2973 case SSH_CIPHER_3DES:
2974 logevent("Using 3DES encryption");
2976 case SSH_CIPHER_DES:
2977 logevent("Using single-DES encryption");
2979 case SSH_CIPHER_BLOWFISH:
2980 logevent("Using Blowfish encryption");
2984 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2985 PKT_CHAR, s->cipher_type,
2986 PKT_DATA, cookie, 8,
2987 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2988 PKT_DATA, s->rsabuf, s->len,
2989 PKT_INT, ssh->v1_local_protoflags, PKT_END);
2991 logevent("Trying to enable encryption...");
2995 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2996 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2998 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2999 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
3000 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
3002 ssh->crcda_ctx = crcda_make_context();
3003 logevent("Installing CRC compensation attack detector");
3005 if (servkey.modulus) {
3006 sfree(servkey.modulus);
3007 servkey.modulus = NULL;
3009 if (servkey.exponent) {
3010 sfree(servkey.exponent);
3011 servkey.exponent = NULL;
3013 if (hostkey.modulus) {
3014 sfree(hostkey.modulus);
3015 hostkey.modulus = NULL;
3017 if (hostkey.exponent) {
3018 sfree(hostkey.exponent);
3019 hostkey.exponent = NULL;
3023 if (pktin->type != SSH1_SMSG_SUCCESS) {
3024 bombout(("Encryption not successfully enabled"));
3028 logevent("Successfully started encryption");
3032 if (!*ssh->cfg.username) {
3033 if (ssh_get_line && !ssh_getline_pw_only) {
3034 if (!ssh_get_line("login as: ",
3035 s->username, sizeof(s->username), FALSE)) {
3037 * get_line failed to get a username.
3040 logevent("No username provided. Abandoning session.");
3041 ssh->close_expected = TRUE;
3042 ssh_closing((Plug)ssh, NULL, 0, 0);
3046 int ret; /* need not be kept over crReturn */
3047 c_write_str(ssh, "login as: ");
3050 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
3052 crWaitUntil(!pktin);
3053 ret = process_userpass_input(ssh, in, inlen);
3057 c_write_str(ssh, "\r\n");
3060 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
3061 s->username[sizeof(s->username)-1] = '\0';
3064 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
3066 char userlog[22 + sizeof(s->username)];
3067 sprintf(userlog, "Sent username \"%s\"", s->username);
3069 if (flags & FLAG_INTERACTIVE &&
3070 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3071 strcat(userlog, "\r\n");
3072 c_write_str(ssh, userlog);
3079 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
3080 /* We must not attempt PK auth. Pretend we've already tried it. */
3081 s->tried_publickey = s->tried_agent = 1;
3083 s->tried_publickey = s->tried_agent = 0;
3085 s->tis_auth_refused = s->ccard_auth_refused = 0;
3086 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
3087 if (!filename_is_null(ssh->cfg.keyfile)) {
3088 if (!rsakey_pubblob(&ssh->cfg.keyfile,
3089 &s->publickey_blob, &s->publickey_bloblen, NULL))
3090 s->publickey_blob = NULL;
3092 s->publickey_blob = NULL;
3094 while (pktin->type == SSH1_SMSG_FAILURE) {
3095 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
3097 if (agent_exists() && !s->tried_agent) {
3099 * Attempt RSA authentication using Pageant.
3105 logevent("Pageant is running. Requesting keys.");
3107 /* Request the keys held by the agent. */
3108 PUT_32BIT(s->request, 1);
3109 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
3110 if (!agent_query(s->request, 5, &r, &s->responselen,
3111 ssh_agent_callback, ssh)) {
3115 bombout(("Unexpected data from server while waiting"
3116 " for agent response"));
3119 } while (pktin || inlen > 0);
3120 r = ssh->agent_response;
3121 s->responselen = ssh->agent_response_len;
3123 s->response = (unsigned char *) r;
3124 if (s->response && s->responselen >= 5 &&
3125 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3126 s->p = s->response + 5;
3127 s->nkeys = GET_32BIT(s->p);
3129 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
3130 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
3131 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
3132 if (s->publickey_blob &&
3133 !memcmp(s->p, s->publickey_blob,
3134 s->publickey_bloblen)) {
3135 logevent("This key matches configured key file");
3136 s->tried_publickey = 1;
3141 do { /* do while (0) to make breaking easy */
3142 n = ssh1_read_bignum
3143 (s->p, s->responselen-(s->p-s->response),
3148 n = ssh1_read_bignum
3149 (s->p, s->responselen-(s->p-s->response),
3154 if (s->responselen - (s->p-s->response) < 4)
3156 s->commentlen = GET_32BIT(s->p);
3158 if (s->responselen - (s->p-s->response) <
3161 s->commentp = (char *)s->p;
3162 s->p += s->commentlen;
3166 logevent("Pageant key list packet was truncated");
3170 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3171 PKT_BIGNUM, s->key.modulus, PKT_END);
3173 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3174 logevent("Key refused");
3177 logevent("Received RSA challenge");
3178 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3179 bombout(("Server's RSA challenge was badly formatted"));
3184 char *agentreq, *q, *ret;
3187 len = 1 + 4; /* message type, bit count */
3188 len += ssh1_bignum_length(s->key.exponent);
3189 len += ssh1_bignum_length(s->key.modulus);
3190 len += ssh1_bignum_length(s->challenge);
3191 len += 16; /* session id */
3192 len += 4; /* response format */
3193 agentreq = snewn(4 + len, char);
3194 PUT_32BIT(agentreq, len);
3196 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
3197 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
3199 q += ssh1_write_bignum(q, s->key.exponent);
3200 q += ssh1_write_bignum(q, s->key.modulus);
3201 q += ssh1_write_bignum(q, s->challenge);
3202 memcpy(q, s->session_id, 16);
3204 PUT_32BIT(q, 1); /* response format */
3205 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3206 ssh_agent_callback, ssh)) {
3211 bombout(("Unexpected data from server"
3212 " while waiting for agent"
3216 } while (pktin || inlen > 0);
3217 vret = ssh->agent_response;
3218 retlen = ssh->agent_response_len;
3223 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3224 logevent("Sending Pageant's response");
3225 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3226 PKT_DATA, ret + 5, 16,
3230 if (pktin->type == SSH1_SMSG_SUCCESS) {
3232 ("Pageant's response accepted");
3233 if (flags & FLAG_VERBOSE) {
3234 c_write_str(ssh, "Authenticated using"
3236 c_write(ssh, s->commentp,
3238 c_write_str(ssh, "\" from agent\r\n");
3243 ("Pageant's response not accepted");
3246 ("Pageant failed to answer challenge");
3250 logevent("No reply received from Pageant");
3253 freebn(s->key.exponent);
3254 freebn(s->key.modulus);
3255 freebn(s->challenge);
3264 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
3265 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
3267 if (ssh->cfg.try_tis_auth &&
3268 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3269 !s->tis_auth_refused) {
3270 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
3271 logevent("Requested TIS authentication");
3272 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
3274 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
3275 logevent("TIS authentication declined");
3276 if (flags & FLAG_INTERACTIVE)
3277 c_write_str(ssh, "TIS authentication refused.\r\n");
3278 s->tis_auth_refused = 1;
3284 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3286 bombout(("TIS challenge packet was badly formed"));
3289 c_write_str(ssh, "Using TIS authentication.\r\n");
3290 logevent("Received TIS challenge");
3291 if (challengelen > sizeof(s->prompt) - 1)
3292 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3293 memcpy(s->prompt, challenge, challengelen);
3294 /* Prompt heuristic comes from OpenSSH */
3295 strncpy(s->prompt + challengelen,
3296 memchr(s->prompt, '\n', challengelen) ?
3297 "": "\r\nResponse: ",
3298 (sizeof s->prompt) - challengelen);
3299 s->prompt[(sizeof s->prompt) - 1] = '\0';
3302 if (ssh->cfg.try_tis_auth &&
3303 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3304 !s->ccard_auth_refused) {
3305 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
3306 logevent("Requested CryptoCard authentication");
3307 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
3309 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
3310 logevent("CryptoCard authentication declined");
3311 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3312 s->ccard_auth_refused = 1;
3318 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3320 bombout(("CryptoCard challenge packet was badly formed"));
3323 c_write_str(ssh, "Using CryptoCard authentication.\r\n");
3324 logevent("Received CryptoCard challenge");
3325 if (challengelen > sizeof(s->prompt) - 1)
3326 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3327 memcpy(s->prompt, challenge, challengelen);
3328 strncpy(s->prompt + challengelen,
3329 memchr(s->prompt, '\n', challengelen) ?
3330 "" : "\r\nResponse: ",
3331 sizeof(s->prompt) - challengelen);
3332 s->prompt[sizeof(s->prompt) - 1] = '\0';
3335 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3336 sprintf(s->prompt, "%.90s@%.90s's password: ",
3337 s->username, ssh->savedhost);
3339 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3340 char *comment = NULL;
3342 if (flags & FLAG_VERBOSE)
3343 c_write_str(ssh, "Trying public key authentication.\r\n");
3344 logeventf(ssh, "Trying public key \"%s\"",
3345 filename_to_str(&ssh->cfg.keyfile));
3346 type = key_type(&ssh->cfg.keyfile);
3347 if (type != SSH_KEYTYPE_SSH1) {
3348 char *msg = dupprintf("Key is of wrong type (%s)",
3349 key_type_to_str(type));
3351 c_write_str(ssh, msg);
3352 c_write_str(ssh, "\r\n");
3354 s->tried_publickey = 1;
3357 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
3358 if (flags & FLAG_VERBOSE)
3359 c_write_str(ssh, "No passphrase required.\r\n");
3362 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
3367 * Show password prompt, having first obtained it via a TIS
3368 * or CryptoCard exchange if we're doing TIS or CryptoCard
3372 if (!ssh_get_line(s->prompt, s->password,
3373 sizeof(s->password), TRUE)) {
3375 * get_line failed to get a password (for example
3376 * because one was supplied on the command line
3377 * which has already failed to work). Terminate.
3379 send_packet(ssh, SSH1_MSG_DISCONNECT,
3380 PKT_STR, "No more passwords available to try",
3382 logevent("Unable to authenticate");
3383 connection_fatal(ssh->frontend, "Unable to authenticate");
3384 ssh->close_expected = TRUE;
3385 ssh_closing((Plug)ssh, NULL, 0, 0);
3389 /* Prompt may have come from server. We've munged it a bit, so
3390 * we know it to be zero-terminated at least once. */
3391 int ret; /* need not be saved over crReturn */
3392 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3395 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
3397 crWaitUntil(!pktin);
3398 ret = process_userpass_input(ssh, in, inlen);
3402 c_write_str(ssh, "\r\n");
3406 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3408 * Try public key authentication with the specified
3411 s->tried_publickey = 1;
3414 const char *error = NULL;
3415 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3418 c_write_str(ssh, "Couldn't load private key from ");
3419 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
3420 c_write_str(ssh, " (");
3421 c_write_str(ssh, error);
3422 c_write_str(ssh, ").\r\n");
3423 continue; /* go and try password */
3426 c_write_str(ssh, "Wrong passphrase.\r\n");
3427 s->tried_publickey = 0;
3428 continue; /* try again */
3433 * Send a public key attempt.
3435 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3436 PKT_BIGNUM, s->key.modulus, PKT_END);
3439 if (pktin->type == SSH1_SMSG_FAILURE) {
3440 c_write_str(ssh, "Server refused our public key.\r\n");
3441 continue; /* go and try password */
3443 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3444 bombout(("Bizarre response to offer of public key"));
3450 unsigned char buffer[32];
3451 Bignum challenge, response;
3453 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3454 bombout(("Server's RSA challenge was badly formatted"));
3457 response = rsadecrypt(challenge, &s->key);
3458 freebn(s->key.private_exponent);/* burn the evidence */
3460 for (i = 0; i < 32; i++) {
3461 buffer[i] = bignum_byte(response, 31 - i);
3465 MD5Update(&md5c, buffer, 32);
3466 MD5Update(&md5c, s->session_id, 16);
3467 MD5Final(buffer, &md5c);
3469 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3470 PKT_DATA, buffer, 16, PKT_END);
3477 if (pktin->type == SSH1_SMSG_FAILURE) {
3478 if (flags & FLAG_VERBOSE)
3479 c_write_str(ssh, "Failed to authenticate with"
3480 " our public key.\r\n");
3481 continue; /* go and try password */
3482 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3483 bombout(("Bizarre response to RSA authentication response"));
3487 break; /* we're through! */
3489 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3491 * Defence against traffic analysis: we send a
3492 * whole bunch of packets containing strings of
3493 * different lengths. One of these strings is the
3494 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3495 * The others are all random data in
3496 * SSH1_MSG_IGNORE packets. This way a passive
3497 * listener can't tell which is the password, and
3498 * hence can't deduce the password length.
3500 * Anybody with a password length greater than 16
3501 * bytes is going to have enough entropy in their
3502 * password that a listener won't find it _that_
3503 * much help to know how long it is. So what we'll
3506 * - if password length < 16, we send 15 packets
3507 * containing string lengths 1 through 15
3509 * - otherwise, we let N be the nearest multiple
3510 * of 8 below the password length, and send 8
3511 * packets containing string lengths N through
3512 * N+7. This won't obscure the order of
3513 * magnitude of the password length, but it will
3514 * introduce a bit of extra uncertainty.
3516 * A few servers (the old 1.2.18 through 1.2.22)
3517 * can't deal with SSH1_MSG_IGNORE. For these
3518 * servers, we need an alternative defence. We make
3519 * use of the fact that the password is interpreted
3520 * as a C string: so we can append a NUL, then some
3523 * One server (a Cisco one) can deal with neither
3524 * SSH1_MSG_IGNORE _nor_ a padded password string.
3525 * For this server we are left with no defences
3526 * against password length sniffing.
3528 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
3530 * The server can deal with SSH1_MSG_IGNORE, so
3531 * we can use the primary defence.
3533 int bottom, top, pwlen, i;
3536 pwlen = strlen(s->password);
3538 bottom = 0; /* zero length passwords are OK! :-) */
3541 bottom = pwlen & ~7;
3545 assert(pwlen >= bottom && pwlen <= top);
3547 randomstr = snewn(top + 1, char);
3549 for (i = bottom; i <= top; i++) {
3551 defer_packet(ssh, s->pwpkt_type,
3552 PKTT_PASSWORD, PKT_STR, s->password,
3553 PKTT_OTHER, PKT_END);
3555 for (j = 0; j < i; j++) {
3557 randomstr[j] = random_byte();
3558 } while (randomstr[j] == '\0');
3560 randomstr[i] = '\0';
3561 defer_packet(ssh, SSH1_MSG_IGNORE,
3562 PKT_STR, randomstr, PKT_END);
3565 logevent("Sending password with camouflage packets");
3566 ssh_pkt_defersend(ssh);
3569 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3571 * The server can't deal with SSH1_MSG_IGNORE
3572 * but can deal with padded passwords, so we
3573 * can use the secondary defence.
3579 len = strlen(s->password);
3580 if (len < sizeof(string)) {
3582 strcpy(string, s->password);
3583 len++; /* cover the zero byte */
3584 while (len < sizeof(string)) {
3585 string[len++] = (char) random_byte();
3590 logevent("Sending length-padded password");
3591 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3592 PKT_INT, len, PKT_DATA, ss, len,
3593 PKTT_OTHER, PKT_END);
3596 * The server has _both_
3597 * BUG_CHOKES_ON_SSH1_IGNORE and
3598 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3599 * therefore nothing we can do.
3602 len = strlen(s->password);
3603 logevent("Sending unpadded password");
3604 send_packet(ssh, s->pwpkt_type,
3605 PKTT_PASSWORD, PKT_INT, len,
3606 PKT_DATA, s->password, len,
3607 PKTT_OTHER, PKT_END);
3610 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3611 PKT_STR, s->password, PKTT_OTHER, PKT_END);
3614 logevent("Sent password");
3615 memset(s->password, 0, strlen(s->password));
3617 if (pktin->type == SSH1_SMSG_FAILURE) {
3618 if (flags & FLAG_VERBOSE)
3619 c_write_str(ssh, "Access denied\r\n");
3620 logevent("Authentication refused");
3621 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3622 bombout(("Strange packet received, type %d", pktin->type));
3627 logevent("Authentication successful");
3632 void sshfwd_close(struct ssh_channel *c)
3636 if (ssh->state == SSH_STATE_CLOSED)
3639 if (c && !c->closes) {
3641 * If halfopen is true, we have sent
3642 * CHANNEL_OPEN for this channel, but it hasn't even been
3643 * acknowledged by the server. So we must set a close flag
3644 * on it now, and then when the server acks the channel
3645 * open, we can close it then.
3648 if (ssh->version == 1) {
3649 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3652 struct Packet *pktout;
3653 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3654 ssh2_pkt_adduint32(pktout, c->remoteid);
3655 ssh2_pkt_send(ssh, pktout);
3658 c->closes = 1; /* sent MSG_CLOSE */
3659 if (c->type == CHAN_X11) {
3661 logevent("Forwarded X11 connection terminated");
3662 } else if (c->type == CHAN_SOCKDATA ||
3663 c->type == CHAN_SOCKDATA_DORMANT) {
3665 logevent("Forwarded port closed");
3670 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3674 if (ssh->state == SSH_STATE_CLOSED)
3677 if (ssh->version == 1) {
3678 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3679 PKT_INT, c->remoteid,
3681 PKT_INT, len, PKT_DATA, buf, len,
3682 PKTT_OTHER, PKT_END);
3684 * In SSH-1 we can return 0 here - implying that forwarded
3685 * connections are never individually throttled - because
3686 * the only circumstance that can cause throttling will be
3687 * the whole SSH connection backing up, in which case
3688 * _everything_ will be throttled as a whole.
3692 ssh2_add_channel_data(c, buf, len);
3693 return ssh2_try_send(c);
3697 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3701 if (ssh->state == SSH_STATE_CLOSED)
3704 if (ssh->version == 1) {
3705 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3706 c->v.v1.throttling = 0;
3707 ssh1_throttle(ssh, -1);
3710 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3714 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
3716 struct queued_handler *qh = ssh->qhead;
3720 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
3723 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
3724 ssh->packet_dispatch[qh->msg1] = NULL;
3727 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
3728 ssh->packet_dispatch[qh->msg2] = NULL;
3732 ssh->qhead = qh->next;
3734 if (ssh->qhead->msg1 > 0) {
3735 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
3736 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
3738 if (ssh->qhead->msg2 > 0) {
3739 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
3740 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
3743 ssh->qhead = ssh->qtail = NULL;
3744 ssh->packet_dispatch[pktin->type] = NULL;
3747 qh->handler(ssh, pktin, qh->ctx);
3752 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
3753 chandler_fn_t handler, void *ctx)
3755 struct queued_handler *qh;
3757 qh = snew(struct queued_handler);
3760 qh->handler = handler;
3764 if (ssh->qtail == NULL) {
3768 assert(ssh->packet_dispatch[qh->msg1] == NULL);
3769 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
3772 assert(ssh->packet_dispatch[qh->msg2] == NULL);
3773 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
3776 ssh->qtail->next = qh;
3781 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
3783 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
3785 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
3786 SSH2_MSG_REQUEST_SUCCESS)) {
3787 logeventf(ssh, "Remote port forwarding from %s enabled",
3790 logeventf(ssh, "Remote port forwarding from %s refused",
3793 rpf = del234(ssh->rportfwds, pf);
3799 static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
3801 const char *portfwd_strptr = cfg->portfwd;
3802 struct ssh_portfwd *epf;
3805 if (!ssh->portfwds) {
3806 ssh->portfwds = newtree234(ssh_portcmp);
3809 * Go through the existing port forwardings and tag them
3810 * with status==DESTROY. Any that we want to keep will be
3811 * re-enabled (status==KEEP) as we go through the
3812 * configuration and find out which bits are the same as
3815 struct ssh_portfwd *epf;
3817 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3818 epf->status = DESTROY;
3821 while (*portfwd_strptr) {
3822 char address_family, type;
3823 int sport,dport,sserv,dserv;
3824 char sports[256], dports[256], saddr[256], host[256];
3827 address_family = 'A';
3829 if (*portfwd_strptr == 'A' ||
3830 *portfwd_strptr == '4' ||
3831 *portfwd_strptr == '6')
3832 address_family = *portfwd_strptr++;
3833 if (*portfwd_strptr == 'L' ||
3834 *portfwd_strptr == 'R' ||
3835 *portfwd_strptr == 'D')
3836 type = *portfwd_strptr++;
3841 while (*portfwd_strptr && *portfwd_strptr != '\t') {
3842 if (*portfwd_strptr == ':') {
3844 * We've seen a colon in the middle of the
3845 * source port number. This means that
3846 * everything we've seen until now is the
3847 * source _address_, so we'll move it into
3848 * saddr and start sports from the beginning
3853 if (ssh->version == 1 && type == 'R') {
3854 logeventf(ssh, "SSH-1 cannot handle remote source address "
3855 "spec \"%s\"; ignoring", sports);
3857 strcpy(saddr, sports);
3860 if (n < lenof(sports)-1) sports[n++] = *portfwd_strptr++;
3864 if (*portfwd_strptr == '\t')
3867 while (*portfwd_strptr && *portfwd_strptr != ':') {
3868 if (n < lenof(host)-1) host[n++] = *portfwd_strptr++;
3871 if (*portfwd_strptr == ':')
3874 while (*portfwd_strptr) {
3875 if (n < lenof(dports)-1) dports[n++] = *portfwd_strptr++;
3879 dport = atoi(dports);
3883 dport = net_service_lookup(dports);
3885 logeventf(ssh, "Service lookup failed for destination"
3886 " port \"%s\"", dports);
3890 while (*portfwd_strptr) portfwd_strptr++;
3894 portfwd_strptr++; /* eat the NUL and move to next one */
3896 sport = atoi(sports);
3900 sport = net_service_lookup(sports);
3902 logeventf(ssh, "Service lookup failed for source"
3903 " port \"%s\"", sports);
3906 if (sport && dport) {
3907 /* Set up a description of the source port. */
3908 struct ssh_portfwd *pfrec, *epfrec;
3910 pfrec = snew(struct ssh_portfwd);
3912 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
3913 pfrec->sserv = sserv ? dupstr(sports) : NULL;
3914 pfrec->sport = sport;
3915 pfrec->daddr = *host ? dupstr(host) : NULL;
3916 pfrec->dserv = dserv ? dupstr(dports) : NULL;
3917 pfrec->dport = dport;
3918 pfrec->local = NULL;
3919 pfrec->remote = NULL;
3920 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
3921 address_family == '6' ? ADDRTYPE_IPV6 :
3924 epfrec = add234(ssh->portfwds, pfrec);
3925 if (epfrec != pfrec) {
3927 * We already have a port forwarding with precisely
3928 * these parameters. Hence, no need to do anything;
3929 * simply tag the existing one as KEEP.
3931 epfrec->status = KEEP;
3932 free_portfwd(pfrec);
3934 pfrec->status = CREATE;
3940 * Now go through and destroy any port forwardings which were
3943 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3944 if (epf->status == DESTROY) {
3947 message = dupprintf("%s port forwarding from %s%s%d",
3948 epf->type == 'L' ? "local" :
3949 epf->type == 'R' ? "remote" : "dynamic",
3950 epf->saddr ? epf->saddr : "",
3951 epf->saddr ? ":" : "",
3954 if (epf->type != 'D') {
3955 char *msg2 = dupprintf("%s to %s:%d", message,
3956 epf->daddr, epf->dport);
3961 logeventf(ssh, "Cancelling %s", message);
3965 struct ssh_rportfwd *rpf = epf->remote;
3966 struct Packet *pktout;
3969 * Cancel the port forwarding at the server
3972 if (ssh->version == 1) {
3974 * We cannot cancel listening ports on the
3975 * server side in SSH-1! There's no message
3976 * to support it. Instead, we simply remove
3977 * the rportfwd record from the local end
3978 * so that any connections the server tries
3979 * to make on it are rejected.
3982 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
3983 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
3984 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
3986 ssh2_pkt_addstring(pktout, epf->saddr);
3987 } else if (ssh->cfg.rport_acceptall) {
3988 /* XXX: ssh->cfg.rport_acceptall may not represent
3989 * what was used to open the original connection,
3990 * since it's reconfigurable. */
3991 ssh2_pkt_addstring(pktout, "0.0.0.0");
3993 ssh2_pkt_addstring(pktout, "127.0.0.1");
3995 ssh2_pkt_adduint32(pktout, epf->sport);
3996 ssh2_pkt_send(ssh, pktout);
3999 del234(ssh->rportfwds, rpf);
4001 } else if (epf->local) {
4002 pfd_terminate(epf->local);
4005 delpos234(ssh->portfwds, i);
4007 i--; /* so we don't skip one in the list */
4011 * And finally, set up any new port forwardings (status==CREATE).
4013 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4014 if (epf->status == CREATE) {
4015 char *sportdesc, *dportdesc;
4016 sportdesc = dupprintf("%s%s%s%s%d%s",
4017 epf->saddr ? epf->saddr : "",
4018 epf->saddr ? ":" : "",
4019 epf->sserv ? epf->sserv : "",
4020 epf->sserv ? "(" : "",
4022 epf->sserv ? ")" : "");
4023 if (epf->type == 'D') {
4026 dportdesc = dupprintf("%s:%s%s%d%s",
4028 epf->dserv ? epf->dserv : "",
4029 epf->dserv ? "(" : "",
4031 epf->dserv ? ")" : "");
4034 if (epf->type == 'L') {
4035 const char *err = pfd_addforward(epf->daddr, epf->dport,
4036 epf->saddr, epf->sport,
4039 epf->addressfamily);
4041 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
4042 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4043 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4044 sportdesc, dportdesc,
4045 err ? " failed: " : "", err ? err : "");
4046 } else if (epf->type == 'D') {
4047 const char *err = pfd_addforward(NULL, -1,
4048 epf->saddr, epf->sport,
4051 epf->addressfamily);
4053 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
4054 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4055 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4057 err ? " failed: " : "", err ? err : "");
4059 struct ssh_rportfwd *pf;
4062 * Ensure the remote port forwardings tree exists.
4064 if (!ssh->rportfwds) {
4065 if (ssh->version == 1)
4066 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
4068 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4071 pf = snew(struct ssh_rportfwd);
4072 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
4073 pf->dhost[lenof(pf->dhost)-1] = '\0';
4074 pf->dport = epf->dport;
4075 pf->sport = epf->sport;
4076 if (add234(ssh->rportfwds, pf) != pf) {
4077 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
4078 epf->daddr, epf->dport);
4081 logeventf(ssh, "Requesting remote port %s"
4082 " forward to %s", sportdesc, dportdesc);
4084 pf->sportdesc = sportdesc;
4089 if (ssh->version == 1) {
4090 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
4091 PKT_INT, epf->sport,
4092 PKT_STR, epf->daddr,
4093 PKT_INT, epf->dport,
4095 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4097 ssh_rportfwd_succfail, pf);
4099 struct Packet *pktout;
4100 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4101 ssh2_pkt_addstring(pktout, "tcpip-forward");
4102 ssh2_pkt_addbool(pktout, 1);/* want reply */
4104 ssh2_pkt_addstring(pktout, epf->saddr);
4105 } else if (cfg->rport_acceptall) {
4106 ssh2_pkt_addstring(pktout, "0.0.0.0");
4108 ssh2_pkt_addstring(pktout, "127.0.0.1");
4110 ssh2_pkt_adduint32(pktout, epf->sport);
4111 ssh2_pkt_send(ssh, pktout);
4113 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4114 SSH2_MSG_REQUEST_FAILURE,
4115 ssh_rportfwd_succfail, pf);
4124 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4127 int stringlen, bufsize;
4129 ssh_pkt_getstring(pktin, &string, &stringlen);
4130 if (string == NULL) {
4131 bombout(("Incoming terminal data packet was badly formed"));
4135 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4137 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4138 ssh->v1_stdout_throttling = 1;
4139 ssh1_throttle(ssh, +1);
4143 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4145 /* Remote side is trying to open a channel to talk to our
4146 * X-Server. Give them back a local channel number. */
4147 struct ssh_channel *c;
4148 int remoteid = ssh_pkt_getuint32(pktin);
4150 logevent("Received X11 connect request");
4151 /* Refuse if X11 forwarding is disabled. */
4152 if (!ssh->X11_fwd_enabled) {
4153 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4154 PKT_INT, remoteid, PKT_END);
4155 logevent("Rejected X11 connect request");
4157 c = snew(struct ssh_channel);
4160 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
4161 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
4162 logevent("Opening X11 forward connection failed");
4164 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4165 PKT_INT, remoteid, PKT_END);
4168 ("Opening X11 forward connection succeeded");
4169 c->remoteid = remoteid;
4170 c->halfopen = FALSE;
4171 c->localid = alloc_channel_id(ssh);
4173 c->v.v1.throttling = 0;
4174 c->type = CHAN_X11; /* identify channel type */
4175 add234(ssh->channels, c);
4176 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4177 PKT_INT, c->remoteid, PKT_INT,
4178 c->localid, PKT_END);
4179 logevent("Opened X11 forward channel");
4184 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4186 /* Remote side is trying to open a channel to talk to our
4187 * agent. Give them back a local channel number. */
4188 struct ssh_channel *c;
4189 int remoteid = ssh_pkt_getuint32(pktin);
4191 /* Refuse if agent forwarding is disabled. */
4192 if (!ssh->agentfwd_enabled) {
4193 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4194 PKT_INT, remoteid, PKT_END);
4196 c = snew(struct ssh_channel);
4198 c->remoteid = remoteid;
4199 c->halfopen = FALSE;
4200 c->localid = alloc_channel_id(ssh);
4202 c->v.v1.throttling = 0;
4203 c->type = CHAN_AGENT; /* identify channel type */
4204 c->u.a.lensofar = 0;
4205 add234(ssh->channels, c);
4206 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4207 PKT_INT, c->remoteid, PKT_INT, c->localid,
4212 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4214 /* Remote side is trying to open a channel to talk to a
4215 * forwarded port. Give them back a local channel number. */
4216 struct ssh_channel *c;
4217 struct ssh_rportfwd pf, *pfp;
4222 c = snew(struct ssh_channel);
4225 remoteid = ssh_pkt_getuint32(pktin);
4226 ssh_pkt_getstring(pktin, &host, &hostsize);
4227 port = ssh_pkt_getuint32(pktin);
4229 if (hostsize >= lenof(pf.dhost))
4230 hostsize = lenof(pf.dhost)-1;
4231 memcpy(pf.dhost, host, hostsize);
4232 pf.dhost[hostsize] = '\0';
4234 pfp = find234(ssh->rportfwds, &pf, NULL);
4237 logeventf(ssh, "Rejected remote port open request for %s:%d",
4239 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4240 PKT_INT, remoteid, PKT_END);
4242 logeventf(ssh, "Received remote port open request for %s:%d",
4244 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
4245 c, &ssh->cfg, pfp->pfrec->addressfamily);
4247 logeventf(ssh, "Port open failed: %s", e);
4249 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4250 PKT_INT, remoteid, PKT_END);
4252 c->remoteid = remoteid;
4253 c->halfopen = FALSE;
4254 c->localid = alloc_channel_id(ssh);
4256 c->v.v1.throttling = 0;
4257 c->type = CHAN_SOCKDATA; /* identify channel type */
4258 add234(ssh->channels, c);
4259 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4260 PKT_INT, c->remoteid, PKT_INT,
4261 c->localid, PKT_END);
4262 logevent("Forwarded port opened successfully");
4267 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4269 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4270 unsigned int localid = ssh_pkt_getuint32(pktin);
4271 struct ssh_channel *c;
4273 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4274 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4275 c->remoteid = localid;
4276 c->halfopen = FALSE;
4277 c->type = CHAN_SOCKDATA;
4278 c->v.v1.throttling = 0;
4279 pfd_confirm(c->u.pfd.s);
4282 if (c && c->closes) {
4284 * We have a pending close on this channel,
4285 * which we decided on before the server acked
4286 * the channel open. So now we know the
4287 * remoteid, we can close it again.
4289 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4290 PKT_INT, c->remoteid, PKT_END);
4294 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4296 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4297 struct ssh_channel *c;
4299 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4300 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4301 logevent("Forwarded connection refused by server");
4302 pfd_close(c->u.pfd.s);
4303 del234(ssh->channels, c);
4308 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4310 /* Remote side closes a channel. */
4311 unsigned i = ssh_pkt_getuint32(pktin);
4312 struct ssh_channel *c;
4313 c = find234(ssh->channels, &i, ssh_channelfind);
4314 if (c && !c->halfopen) {
4317 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4319 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4320 logevent("Forwarded X11 connection terminated");
4321 assert(c->u.x11.s != NULL);
4322 x11_close(c->u.x11.s);
4325 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4326 logevent("Forwarded port closed");
4327 assert(c->u.pfd.s != NULL);
4328 pfd_close(c->u.pfd.s);
4332 c->closes |= (closetype << 2); /* seen this message */
4333 if (!(c->closes & closetype)) {
4334 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4336 c->closes |= closetype; /* sent it too */
4339 if (c->closes == 15) {
4340 del234(ssh->channels, c);
4344 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4345 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4346 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4351 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4353 /* Data sent down one of our channels. */
4354 int i = ssh_pkt_getuint32(pktin);
4357 struct ssh_channel *c;
4359 ssh_pkt_getstring(pktin, &p, &len);
4361 c = find234(ssh->channels, &i, ssh_channelfind);
4366 bufsize = x11_send(c->u.x11.s, p, len);
4369 bufsize = pfd_send(c->u.pfd.s, p, len);
4372 /* Data for an agent message. Buffer it. */
4374 if (c->u.a.lensofar < 4) {
4375 unsigned int l = min(4 - c->u.a.lensofar, len);
4376 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4380 c->u.a.lensofar += l;
4382 if (c->u.a.lensofar == 4) {
4384 4 + GET_32BIT(c->u.a.msglen);
4385 c->u.a.message = snewn(c->u.a.totallen,
4387 memcpy(c->u.a.message, c->u.a.msglen, 4);
4389 if (c->u.a.lensofar >= 4 && len > 0) {
4391 min(c->u.a.totallen - c->u.a.lensofar,
4393 memcpy(c->u.a.message + c->u.a.lensofar, p,
4397 c->u.a.lensofar += l;
4399 if (c->u.a.lensofar == c->u.a.totallen) {
4402 if (agent_query(c->u.a.message,
4405 ssh_agentf_callback, c))
4406 ssh_agentf_callback(c, reply, replylen);
4407 sfree(c->u.a.message);
4408 c->u.a.lensofar = 0;
4411 bufsize = 0; /* agent channels never back up */
4414 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4415 c->v.v1.throttling = 1;
4416 ssh1_throttle(ssh, +1);
4421 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
4423 ssh->exitcode = ssh_pkt_getuint32(pktin);
4424 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
4425 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4427 * In case `helpful' firewalls or proxies tack
4428 * extra human-readable text on the end of the
4429 * session which we might mistake for another
4430 * encrypted packet, we close the session once
4431 * we've sent EXIT_CONFIRMATION.
4433 ssh->close_expected = TRUE;
4434 ssh_closing((Plug)ssh, NULL, 0, 0);
4437 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
4438 struct Packet *pktin)
4440 crBegin(ssh->do_ssh1_connection_crstate);
4442 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
4443 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
4444 ssh1_smsg_stdout_stderr_data;
4446 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
4447 ssh1_msg_channel_open_confirmation;
4448 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
4449 ssh1_msg_channel_open_failure;
4450 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
4451 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
4452 ssh1_msg_channel_close;
4453 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
4454 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
4456 if (ssh->cfg.agentfwd && agent_exists()) {
4457 logevent("Requesting agent forwarding");
4458 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
4462 if (pktin->type != SSH1_SMSG_SUCCESS
4463 && pktin->type != SSH1_SMSG_FAILURE) {
4464 bombout(("Protocol confusion"));
4466 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4467 logevent("Agent forwarding refused");
4469 logevent("Agent forwarding enabled");
4470 ssh->agentfwd_enabled = TRUE;
4471 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
4475 if (ssh->cfg.x11_forward) {
4476 char proto[20], data[64];
4477 logevent("Requesting X11 forwarding");
4478 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
4479 data, sizeof(data), ssh->cfg.x11_auth);
4480 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
4481 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
4482 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4483 PKT_STR, proto, PKT_STR, data,
4484 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
4487 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4488 PKT_STR, proto, PKT_STR, data, PKT_END);
4493 if (pktin->type != SSH1_SMSG_SUCCESS
4494 && pktin->type != SSH1_SMSG_FAILURE) {
4495 bombout(("Protocol confusion"));
4497 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4498 logevent("X11 forwarding refused");
4500 logevent("X11 forwarding enabled");
4501 ssh->X11_fwd_enabled = TRUE;
4502 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
4506 ssh_setup_portfwd(ssh, &ssh->cfg);
4507 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
4509 if (!ssh->cfg.nopty) {
4510 /* Unpick the terminal-speed string. */
4511 /* XXX perhaps we should allow no speeds to be sent. */
4512 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4513 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
4514 /* Send the pty request. */
4515 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
4516 PKT_STR, ssh->cfg.termtype,
4517 PKT_INT, ssh->term_height,
4518 PKT_INT, ssh->term_width,
4519 PKT_INT, 0, PKT_INT, 0, /* width,height in pixels */
4520 PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */
4521 PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */
4522 PKT_CHAR, 0, PKT_END);
4523 ssh->state = SSH_STATE_INTERMED;
4527 if (pktin->type != SSH1_SMSG_SUCCESS
4528 && pktin->type != SSH1_SMSG_FAILURE) {
4529 bombout(("Protocol confusion"));
4531 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4532 c_write_str(ssh, "Server refused to allocate pty\r\n");
4533 ssh->editing = ssh->echoing = 1;
4535 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
4536 ssh->ospeed, ssh->ispeed);
4538 ssh->editing = ssh->echoing = 1;
4541 if (ssh->cfg.compression) {
4542 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
4546 if (pktin->type != SSH1_SMSG_SUCCESS
4547 && pktin->type != SSH1_SMSG_FAILURE) {
4548 bombout(("Protocol confusion"));
4550 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4551 c_write_str(ssh, "Server refused to compress\r\n");
4553 logevent("Started compression");
4554 ssh->v1_compressing = TRUE;
4555 ssh->cs_comp_ctx = zlib_compress_init();
4556 logevent("Initialised zlib (RFC1950) compression");
4557 ssh->sc_comp_ctx = zlib_decompress_init();
4558 logevent("Initialised zlib (RFC1950) decompression");
4562 * Start the shell or command.
4564 * Special case: if the first-choice command is an SSH-2
4565 * subsystem (hence not usable here) and the second choice
4566 * exists, we fall straight back to that.
4569 char *cmd = ssh->cfg.remote_cmd_ptr;
4571 if (!cmd) cmd = ssh->cfg.remote_cmd;
4573 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4574 cmd = ssh->cfg.remote_cmd_ptr2;
4575 ssh->fallback_cmd = TRUE;
4578 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
4580 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
4581 logevent("Started session");
4584 ssh->state = SSH_STATE_SESSION;
4585 if (ssh->size_needed)
4586 ssh_size(ssh, ssh->term_width, ssh->term_height);
4587 if (ssh->eof_needed)
4588 ssh_special(ssh, TS_EOF);
4591 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
4593 ssh->channels = newtree234(ssh_channelcmp);
4597 * By this point, most incoming packets are already being
4598 * handled by the dispatch table, and we need only pay
4599 * attention to the unusual ones.
4604 if (pktin->type == SSH1_SMSG_SUCCESS) {
4605 /* may be from EXEC_SHELL on some servers */
4606 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4607 /* may be from EXEC_SHELL on some servers
4608 * if no pty is available or in other odd cases. Ignore */
4610 bombout(("Strange packet received: type %d", pktin->type));
4615 int len = min(inlen, 512);
4616 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4617 PKT_INT, len, PKT_DATA, in, len,
4618 PKTT_OTHER, PKT_END);
4629 * Handle the top-level SSH-2 protocol.
4631 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4636 ssh_pkt_getstring(pktin, &msg, &msglen);
4637 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
4640 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4642 /* log reason code in disconnect message */
4646 ssh_pkt_getstring(pktin, &msg, &msglen);
4647 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4650 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
4652 /* Do nothing, because we're ignoring it! Duhh. */
4655 static void ssh1_protocol_setup(Ssh ssh)
4660 * Most messages are handled by the coroutines.
4662 for (i = 0; i < 256; i++)
4663 ssh->packet_dispatch[i] = NULL;
4666 * These special message types we install handlers for.
4668 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4669 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4670 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4673 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
4674 struct Packet *pktin)
4676 unsigned char *in=(unsigned char*)vin;
4677 if (ssh->state == SSH_STATE_CLOSED)
4680 if (pktin && ssh->packet_dispatch[pktin->type]) {
4681 ssh->packet_dispatch[pktin->type](ssh, pktin);
4685 if (!ssh->protocol_initial_phase_done) {
4686 if (do_ssh1_login(ssh, in, inlen, pktin))
4687 ssh->protocol_initial_phase_done = TRUE;
4692 do_ssh1_connection(ssh, in, inlen, pktin);
4696 * Utility routine for decoding comma-separated strings in KEXINIT.
4698 static int in_commasep_string(char *needle, char *haystack, int haylen)
4701 if (!needle || !haystack) /* protect against null pointers */
4703 needlen = strlen(needle);
4706 * Is it at the start of the string?
4708 if (haylen >= needlen && /* haystack is long enough */
4709 !memcmp(needle, haystack, needlen) && /* initial match */
4710 (haylen == needlen || haystack[needlen] == ',')
4711 /* either , or EOS follows */
4715 * If not, search for the next comma and resume after that.
4716 * If no comma found, terminate.
4718 while (haylen > 0 && *haystack != ',')
4719 haylen--, haystack++;
4722 haylen--, haystack++; /* skip over comma itself */
4727 * Similar routine for checking whether we have the first string in a list.
4729 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
4732 if (!needle || !haystack) /* protect against null pointers */
4734 needlen = strlen(needle);
4736 * Is it at the start of the string?
4738 if (haylen >= needlen && /* haystack is long enough */
4739 !memcmp(needle, haystack, needlen) && /* initial match */
4740 (haylen == needlen || haystack[needlen] == ',')
4741 /* either , or EOS follows */
4749 * SSH-2 key creation method.
4751 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4752 unsigned char *sessid, char chr,
4753 unsigned char *keyspace)
4756 /* First 20 bytes. */
4758 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4760 SHA_Bytes(&s, H, 20);
4761 SHA_Bytes(&s, &chr, 1);
4762 SHA_Bytes(&s, sessid, 20);
4763 SHA_Final(&s, keyspace);
4764 /* Next 20 bytes. */
4766 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4768 SHA_Bytes(&s, H, 20);
4769 SHA_Bytes(&s, keyspace, 20);
4770 SHA_Final(&s, keyspace + 20);
4774 * Handle the SSH-2 transport layer.
4776 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
4777 struct Packet *pktin)
4779 unsigned char *in = (unsigned char *)vin;
4780 struct do_ssh2_transport_state {
4781 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
4782 Bignum p, g, e, f, K;
4783 int kex_init_value, kex_reply_value;
4784 const struct ssh_mac **maclist;
4786 const struct ssh2_cipher *cscipher_tobe;
4787 const struct ssh2_cipher *sccipher_tobe;
4788 const struct ssh_mac *csmac_tobe;
4789 const struct ssh_mac *scmac_tobe;
4790 const struct ssh_compress *cscomp_tobe;
4791 const struct ssh_compress *sccomp_tobe;
4792 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4793 int hostkeylen, siglen;
4794 void *hkey; /* actual host key */
4795 unsigned char exchange_hash[20];
4796 int n_preferred_kex;
4797 const struct ssh_kex *preferred_kex[KEX_MAX];
4798 int n_preferred_ciphers;
4799 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4800 const struct ssh_compress *preferred_comp;
4801 int got_session_id, activated_authconn;
4802 struct Packet *pktout;
4807 crState(do_ssh2_transport_state);
4809 crBegin(ssh->do_ssh2_transport_crstate);
4811 s->cscipher_tobe = s->sccipher_tobe = NULL;
4812 s->csmac_tobe = s->scmac_tobe = NULL;
4813 s->cscomp_tobe = s->sccomp_tobe = NULL;
4815 s->got_session_id = s->activated_authconn = FALSE;
4818 * Be prepared to work around the buggy MAC problem.
4820 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4821 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
4823 s->maclist = macs, s->nmacs = lenof(macs);
4826 ssh->pkt_ctx &= ~SSH2_PKTCTX_KEX_MASK;
4828 int i, j, commalist_started;
4831 * Set up the preferred key exchange. (NULL => warn below here)
4833 s->n_preferred_kex = 0;
4834 for (i = 0; i < KEX_MAX; i++) {
4835 switch (ssh->cfg.ssh_kexlist[i]) {
4837 s->preferred_kex[s->n_preferred_kex++] =
4838 &ssh_diffiehellman_gex;
4841 s->preferred_kex[s->n_preferred_kex++] =
4842 &ssh_diffiehellman_group14;
4845 s->preferred_kex[s->n_preferred_kex++] =
4846 &ssh_diffiehellman_group1;
4849 /* Flag for later. Don't bother if it's the last in
4851 if (i < KEX_MAX - 1) {
4852 s->preferred_kex[s->n_preferred_kex++] = NULL;
4859 * Set up the preferred ciphers. (NULL => warn below here)
4861 s->n_preferred_ciphers = 0;
4862 for (i = 0; i < CIPHER_MAX; i++) {
4863 switch (ssh->cfg.ssh_cipherlist[i]) {
4864 case CIPHER_BLOWFISH:
4865 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
4868 if (ssh->cfg.ssh2_des_cbc) {
4869 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
4873 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
4876 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
4878 case CIPHER_ARCFOUR:
4879 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
4882 /* Flag for later. Don't bother if it's the last in
4884 if (i < CIPHER_MAX - 1) {
4885 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
4892 * Set up preferred compression.
4894 if (ssh->cfg.compression)
4895 s->preferred_comp = &ssh_zlib;
4897 s->preferred_comp = &ssh_comp_none;
4900 * Enable queueing of outgoing auth- or connection-layer
4901 * packets while we are in the middle of a key exchange.
4903 ssh->queueing = TRUE;
4906 * Flag that KEX is in progress.
4908 ssh->kex_in_progress = TRUE;
4911 * Construct and send our key exchange packet.
4913 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
4914 for (i = 0; i < 16; i++)
4915 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
4916 /* List key exchange algorithms. */
4917 ssh2_pkt_addstring_start(s->pktout);
4918 commalist_started = 0;
4919 for (i = 0; i < s->n_preferred_kex; i++) {
4920 const struct ssh_kex *k = s->preferred_kex[i];
4921 if (!k) continue; /* warning flag */
4922 if (commalist_started)
4923 ssh2_pkt_addstring_str(s->pktout, ",");
4924 ssh2_pkt_addstring_str(s->pktout, s->preferred_kex[i]->name);
4925 commalist_started = 1;
4927 /* List server host key algorithms. */
4928 ssh2_pkt_addstring_start(s->pktout);
4929 for (i = 0; i < lenof(hostkey_algs); i++) {
4930 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
4931 if (i < lenof(hostkey_algs) - 1)
4932 ssh2_pkt_addstring_str(s->pktout, ",");
4934 /* List client->server encryption algorithms. */
4935 ssh2_pkt_addstring_start(s->pktout);
4936 commalist_started = 0;
4937 for (i = 0; i < s->n_preferred_ciphers; i++) {
4938 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4939 if (!c) continue; /* warning flag */
4940 for (j = 0; j < c->nciphers; j++) {
4941 if (commalist_started)
4942 ssh2_pkt_addstring_str(s->pktout, ",");
4943 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
4944 commalist_started = 1;
4947 /* List server->client encryption algorithms. */
4948 ssh2_pkt_addstring_start(s->pktout);
4949 commalist_started = 0;
4950 for (i = 0; i < s->n_preferred_ciphers; i++) {
4951 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4952 if (!c) continue; /* warning flag */
4953 for (j = 0; j < c->nciphers; j++) {
4954 if (commalist_started)
4955 ssh2_pkt_addstring_str(s->pktout, ",");
4956 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
4957 commalist_started = 1;
4960 /* List client->server MAC algorithms. */
4961 ssh2_pkt_addstring_start(s->pktout);
4962 for (i = 0; i < s->nmacs; i++) {
4963 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
4964 if (i < s->nmacs - 1)
4965 ssh2_pkt_addstring_str(s->pktout, ",");
4967 /* List server->client MAC algorithms. */
4968 ssh2_pkt_addstring_start(s->pktout);
4969 for (i = 0; i < s->nmacs; i++) {
4970 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
4971 if (i < s->nmacs - 1)
4972 ssh2_pkt_addstring_str(s->pktout, ",");
4974 /* List client->server compression algorithms. */
4975 ssh2_pkt_addstring_start(s->pktout);
4976 assert(lenof(compressions) > 1);
4977 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
4978 for (i = 0; i < lenof(compressions); i++) {
4979 const struct ssh_compress *c = compressions[i];
4980 if (c != s->preferred_comp) {
4981 ssh2_pkt_addstring_str(s->pktout, ",");
4982 ssh2_pkt_addstring_str(s->pktout, c->name);
4985 /* List server->client compression algorithms. */
4986 ssh2_pkt_addstring_start(s->pktout);
4987 assert(lenof(compressions) > 1);
4988 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
4989 for (i = 0; i < lenof(compressions); i++) {
4990 const struct ssh_compress *c = compressions[i];
4991 if (c != s->preferred_comp) {
4992 ssh2_pkt_addstring_str(s->pktout, ",");
4993 ssh2_pkt_addstring_str(s->pktout, c->name);
4996 /* List client->server languages. Empty list. */
4997 ssh2_pkt_addstring_start(s->pktout);
4998 /* List server->client languages. Empty list. */
4999 ssh2_pkt_addstring_start(s->pktout);
5000 /* First KEX packet does _not_ follow, because we're not that brave. */
5001 ssh2_pkt_addbool(s->pktout, FALSE);
5003 ssh2_pkt_adduint32(s->pktout, 0);
5006 ssh->exhash = ssh->exhashbase;
5007 sha_string(&ssh->exhash, s->pktout->data + 5, s->pktout->length - 5);
5009 ssh2_pkt_send_noqueue(ssh, s->pktout);
5013 if (pktin->length > 5)
5014 sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5);
5017 * Now examine the other side's KEXINIT to see what we're up
5021 char *str, *preferred;
5024 if (pktin->type != SSH2_MSG_KEXINIT) {
5025 bombout(("expected key exchange packet from server"));
5029 ssh->hostkey = NULL;
5030 s->cscipher_tobe = NULL;
5031 s->sccipher_tobe = NULL;
5032 s->csmac_tobe = NULL;
5033 s->scmac_tobe = NULL;
5034 s->cscomp_tobe = NULL;
5035 s->sccomp_tobe = NULL;
5036 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
5038 pktin->savedpos += 16; /* skip garbage cookie */
5039 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
5042 for (i = 0; i < s->n_preferred_kex; i++) {
5043 const struct ssh_kex *k = s->preferred_kex[i];
5047 if (!preferred) preferred = k->name;
5048 if (in_commasep_string(k->name, str, len))
5055 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5056 str ? str : "(null)"));
5060 * Note that the server's guess is considered wrong if it doesn't match
5061 * the first algorithm in our list, even if it's still the algorithm
5064 s->guessok = first_in_commasep_string(preferred, str, len);
5065 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
5066 for (i = 0; i < lenof(hostkey_algs); i++) {
5067 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5068 ssh->hostkey = hostkey_algs[i];
5072 s->guessok = s->guessok &&
5073 first_in_commasep_string(hostkey_algs[0]->name, str, len);
5074 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
5075 for (i = 0; i < s->n_preferred_ciphers; i++) {
5076 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5078 s->warn_cscipher = TRUE;
5080 for (j = 0; j < c->nciphers; j++) {
5081 if (in_commasep_string(c->list[j]->name, str, len)) {
5082 s->cscipher_tobe = c->list[j];
5087 if (s->cscipher_tobe)
5090 if (!s->cscipher_tobe) {
5091 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
5092 str ? str : "(null)"));
5096 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
5097 for (i = 0; i < s->n_preferred_ciphers; i++) {
5098 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5100 s->warn_sccipher = TRUE;
5102 for (j = 0; j < c->nciphers; j++) {
5103 if (in_commasep_string(c->list[j]->name, str, len)) {
5104 s->sccipher_tobe = c->list[j];
5109 if (s->sccipher_tobe)
5112 if (!s->sccipher_tobe) {
5113 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
5114 str ? str : "(null)"));
5118 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
5119 for (i = 0; i < s->nmacs; i++) {
5120 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5121 s->csmac_tobe = s->maclist[i];
5125 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
5126 for (i = 0; i < s->nmacs; i++) {
5127 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5128 s->scmac_tobe = s->maclist[i];
5132 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
5133 for (i = 0; i < lenof(compressions) + 1; i++) {
5134 const struct ssh_compress *c =
5135 i == 0 ? s->preferred_comp : compressions[i - 1];
5136 if (in_commasep_string(c->name, str, len)) {
5141 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
5142 for (i = 0; i < lenof(compressions) + 1; i++) {
5143 const struct ssh_compress *c =
5144 i == 0 ? s->preferred_comp : compressions[i - 1];
5145 if (in_commasep_string(c->name, str, len)) {
5150 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5151 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
5152 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
5155 ssh_set_frozen(ssh, 1);
5156 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
5158 ssh_dialog_callback, ssh);
5159 if (s->dlgret < 0) {
5163 bombout(("Unexpected data from server while"
5164 " waiting for user response"));
5167 } while (pktin || inlen > 0);
5168 s->dlgret = ssh->user_response;
5170 ssh_set_frozen(ssh, 0);
5171 if (s->dlgret == 0) {
5172 ssh->close_expected = TRUE;
5173 ssh_closing((Plug)ssh, NULL, 0, 0);
5178 if (s->warn_cscipher) {
5179 ssh_set_frozen(ssh, 1);
5180 s->dlgret = askalg(ssh->frontend,
5181 "client-to-server cipher",
5182 s->cscipher_tobe->name,
5183 ssh_dialog_callback, ssh);
5184 if (s->dlgret < 0) {
5188 bombout(("Unexpected data from server while"
5189 " waiting for user response"));
5192 } while (pktin || inlen > 0);
5193 s->dlgret = ssh->user_response;
5195 ssh_set_frozen(ssh, 0);
5196 if (s->dlgret == 0) {
5197 ssh->close_expected = TRUE;
5198 ssh_closing((Plug)ssh, NULL, 0, 0);
5203 if (s->warn_sccipher) {
5204 ssh_set_frozen(ssh, 1);
5205 s->dlgret = askalg(ssh->frontend,
5206 "server-to-client cipher",
5207 s->sccipher_tobe->name,
5208 ssh_dialog_callback, ssh);
5209 if (s->dlgret < 0) {
5213 bombout(("Unexpected data from server while"
5214 " waiting for user response"));
5217 } while (pktin || inlen > 0);
5218 s->dlgret = ssh->user_response;
5220 ssh_set_frozen(ssh, 0);
5221 if (s->dlgret == 0) {
5222 ssh->close_expected = TRUE;
5223 ssh_closing((Plug)ssh, NULL, 0, 0);
5228 if (s->ignorepkt) /* first_kex_packet_follows */
5229 crWaitUntil(pktin); /* Ignore packet */
5233 * Work out the number of bits of key we will need from the key
5234 * exchange. We start with the maximum key length of either
5240 csbits = s->cscipher_tobe->keylen;
5241 scbits = s->sccipher_tobe->keylen;
5242 s->nbits = (csbits > scbits ? csbits : scbits);
5244 /* The keys only have 160-bit entropy, since they're based on
5245 * a SHA-1 hash. So cap the key size at 160 bits. */
5250 * If we're doing Diffie-Hellman group exchange, start by
5251 * requesting a group.
5253 if (!ssh->kex->pdata) {
5254 logevent("Doing Diffie-Hellman group exchange");
5255 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
5257 * Work out how big a DH group we will need to allow that
5260 s->pbits = 512 << ((s->nbits - 1) / 64);
5261 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5262 ssh2_pkt_adduint32(s->pktout, s->pbits);
5263 ssh2_pkt_send_noqueue(ssh, s->pktout);
5266 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
5267 bombout(("expected key exchange group packet from server"));
5270 s->p = ssh2_pkt_getmp(pktin);
5271 s->g = ssh2_pkt_getmp(pktin);
5272 if (!s->p || !s->g) {
5273 bombout(("unable to read mp-ints from incoming group packet"));
5276 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
5277 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5278 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
5280 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP;
5281 ssh->kex_ctx = dh_setup_group(ssh->kex);
5282 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5283 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
5284 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5285 ssh->kex->groupname);
5288 logevent("Doing Diffie-Hellman key exchange");
5290 * Now generate and send e for Diffie-Hellman.
5292 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
5293 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
5294 s->pktout = ssh2_pkt_init(s->kex_init_value);
5295 ssh2_pkt_addmp(s->pktout, s->e);
5296 ssh2_pkt_send_noqueue(ssh, s->pktout);
5298 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
5300 if (pktin->type != s->kex_reply_value) {
5301 bombout(("expected key exchange reply packet from server"));
5304 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
5305 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5306 s->f = ssh2_pkt_getmp(pktin);
5308 bombout(("unable to parse key exchange reply packet"));
5311 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
5313 s->K = dh_find_K(ssh->kex_ctx, s->f);
5315 /* We assume everything from now on will be quick, and it might
5316 * involve user interaction. */
5317 set_busy_status(ssh->frontend, BUSY_NOT);
5319 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
5320 if (ssh->kex == &ssh_diffiehellman_gex) {
5321 sha_uint32(&ssh->exhash, s->pbits);
5322 sha_mpint(&ssh->exhash, s->p);
5323 sha_mpint(&ssh->exhash, s->g);
5325 sha_mpint(&ssh->exhash, s->e);
5326 sha_mpint(&ssh->exhash, s->f);
5327 sha_mpint(&ssh->exhash, s->K);
5328 SHA_Final(&ssh->exhash, s->exchange_hash);
5330 dh_cleanup(ssh->kex_ctx);
5331 ssh->kex_ctx = NULL;
5334 debug(("Exchange hash is:\n"));
5335 dmemdump(s->exchange_hash, 20);
5338 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5340 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
5341 (char *)s->exchange_hash, 20)) {
5342 bombout(("Server's host key did not match the signature supplied"));
5347 * Authenticate remote host: verify host key. (We've already
5348 * checked the signature of the exchange hash.)
5350 s->keystr = ssh->hostkey->fmtkey(s->hkey);
5351 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
5352 ssh_set_frozen(ssh, 1);
5353 s->dlgret = verify_ssh_host_key(ssh->frontend,
5354 ssh->savedhost, ssh->savedport,
5355 ssh->hostkey->keytype, s->keystr,
5357 ssh_dialog_callback, ssh);
5358 if (s->dlgret < 0) {
5362 bombout(("Unexpected data from server while waiting"
5363 " for user host key response"));
5366 } while (pktin || inlen > 0);
5367 s->dlgret = ssh->user_response;
5369 ssh_set_frozen(ssh, 0);
5370 if (s->dlgret == 0) {
5371 ssh->close_expected = TRUE;
5372 ssh_closing((Plug)ssh, NULL, 0, 0);
5375 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5376 logevent("Host key fingerprint is:");
5377 logevent(s->fingerprint);
5379 sfree(s->fingerprint);
5381 ssh->hostkey->freekey(s->hkey);
5384 * The exchange hash from the very first key exchange is also
5385 * the session id, used in session key construction and
5388 if (!s->got_session_id) {
5389 memcpy(ssh->v2_session_id, s->exchange_hash,
5390 sizeof(s->exchange_hash));
5391 s->got_session_id = TRUE;
5395 * Send SSH2_MSG_NEWKEYS.
5397 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
5398 ssh2_pkt_send_noqueue(ssh, s->pktout);
5399 ssh->outgoing_data_size = 0; /* start counting from here */
5402 * We've sent client NEWKEYS, so create and initialise
5403 * client-to-server session keys.
5405 if (ssh->cs_cipher_ctx)
5406 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
5407 ssh->cscipher = s->cscipher_tobe;
5408 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
5410 if (ssh->cs_mac_ctx)
5411 ssh->csmac->free_context(ssh->cs_mac_ctx);
5412 ssh->csmac = s->csmac_tobe;
5413 ssh->cs_mac_ctx = ssh->csmac->make_context();
5415 if (ssh->cs_comp_ctx)
5416 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
5417 ssh->cscomp = s->cscomp_tobe;
5418 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
5421 * Set IVs on client-to-server keys. Here we use the exchange
5422 * hash from the _first_ key exchange.
5425 unsigned char keyspace[40];
5426 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
5427 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
5428 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
5429 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
5430 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
5431 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
5434 logeventf(ssh, "Initialised %.200s client->server encryption",
5435 ssh->cscipher->text_name);
5436 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
5437 ssh->csmac->text_name);
5438 if (ssh->cscomp->text_name)
5439 logeventf(ssh, "Initialised %s compression",
5440 ssh->cscomp->text_name);
5443 * Now our end of the key exchange is complete, we can send all
5444 * our queued higher-layer packets.
5446 ssh->queueing = FALSE;
5447 ssh2_pkt_queuesend(ssh);
5450 * Expect SSH2_MSG_NEWKEYS from server.
5453 if (pktin->type != SSH2_MSG_NEWKEYS) {
5454 bombout(("expected new-keys packet from server"));
5457 ssh->incoming_data_size = 0; /* start counting from here */
5460 * We've seen server NEWKEYS, so create and initialise
5461 * server-to-client session keys.
5463 if (ssh->sc_cipher_ctx)
5464 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
5465 ssh->sccipher = s->sccipher_tobe;
5466 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
5468 if (ssh->sc_mac_ctx)
5469 ssh->scmac->free_context(ssh->sc_mac_ctx);
5470 ssh->scmac = s->scmac_tobe;
5471 ssh->sc_mac_ctx = ssh->scmac->make_context();
5473 if (ssh->sc_comp_ctx)
5474 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
5475 ssh->sccomp = s->sccomp_tobe;
5476 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
5479 * Set IVs on server-to-client keys. Here we use the exchange
5480 * hash from the _first_ key exchange.
5483 unsigned char keyspace[40];
5484 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
5485 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
5486 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
5487 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
5488 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
5489 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
5491 logeventf(ssh, "Initialised %.200s server->client encryption",
5492 ssh->sccipher->text_name);
5493 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
5494 ssh->scmac->text_name);
5495 if (ssh->sccomp->text_name)
5496 logeventf(ssh, "Initialised %s decompression",
5497 ssh->sccomp->text_name);
5500 * Free key exchange data.
5504 if (ssh->kex == &ssh_diffiehellman_gex) {
5510 * Key exchange is over. Loop straight back round if we have a
5511 * deferred rekey reason.
5513 if (ssh->deferred_rekey_reason) {
5514 logevent(ssh->deferred_rekey_reason);
5516 ssh->deferred_rekey_reason = NULL;
5517 goto begin_key_exchange;
5521 * Otherwise, schedule a timer for our next rekey.
5523 ssh->kex_in_progress = FALSE;
5524 ssh->last_rekey = GETTICKCOUNT();
5525 if (ssh->cfg.ssh_rekey_time != 0)
5526 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5530 * If this is the first key exchange phase, we must pass the
5531 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
5532 * wants to see it but because it will need time to initialise
5533 * itself before it sees an actual packet. In subsequent key
5534 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
5535 * it would only confuse the layer above.
5537 if (s->activated_authconn) {
5540 s->activated_authconn = TRUE;
5543 * Now we're encrypting. Begin returning 1 to the protocol main
5544 * function so that other things can run on top of the
5545 * transport. If we ever see a KEXINIT, we must go back to the
5548 * We _also_ go back to the start if we see pktin==NULL and
5549 * inlen==-1, because this is a special signal meaning
5550 * `initiate client-driven rekey', and `in' contains a message
5551 * giving the reason for the rekey.
5553 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
5554 (!pktin && inlen == -1))) {
5559 logevent("Server initiated key re-exchange");
5562 * Special case: if the server bug is set that doesn't
5563 * allow rekeying, we give a different log message and
5564 * continue waiting. (If such a server _initiates_ a rekey,
5565 * we process it anyway!)
5567 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
5568 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
5570 /* Reset the counters, so that at least this message doesn't
5571 * hit the event log _too_ often. */
5572 ssh->outgoing_data_size = 0;
5573 ssh->incoming_data_size = 0;
5574 if (ssh->cfg.ssh_rekey_time != 0) {
5576 schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5579 goto wait_for_rekey; /* this is utterly horrid */
5581 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
5584 goto begin_key_exchange;
5590 * Add data to an SSH-2 channel output buffer.
5592 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
5595 bufchain_add(&c->v.v2.outbuffer, buf, len);
5599 * Attempt to send data on an SSH-2 channel.
5601 static int ssh2_try_send(struct ssh_channel *c)
5604 struct Packet *pktout;
5606 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
5609 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
5610 if ((unsigned)len > c->v.v2.remwindow)
5611 len = c->v.v2.remwindow;
5612 if ((unsigned)len > c->v.v2.remmaxpkt)
5613 len = c->v.v2.remmaxpkt;
5614 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
5615 ssh2_pkt_adduint32(pktout, c->remoteid);
5616 dont_log_data(ssh, pktout, PKTLOG_OMIT);
5617 ssh2_pkt_addstring_start(pktout);
5618 ssh2_pkt_addstring_data(pktout, data, len);
5619 end_log_omission(ssh, pktout);
5620 ssh2_pkt_send(ssh, pktout);
5621 bufchain_consume(&c->v.v2.outbuffer, len);
5622 c->v.v2.remwindow -= len;
5626 * After having sent as much data as we can, return the amount
5629 return bufchain_size(&c->v.v2.outbuffer);
5632 static void ssh2_try_send_and_unthrottle(struct ssh_channel *c)
5636 return; /* don't send on closing channels */
5637 bufsize = ssh2_try_send(c);
5640 case CHAN_MAINSESSION:
5641 /* stdin need not receive an unthrottle
5642 * notification since it will be polled */
5645 x11_unthrottle(c->u.x11.s);
5648 /* agent sockets are request/response and need no
5649 * buffer management */
5652 pfd_unthrottle(c->u.pfd.s);
5659 * Potentially enlarge the window on an SSH-2 channel.
5661 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
5666 * Never send WINDOW_ADJUST for a channel that the remote side
5667 * already thinks it's closed; there's no point, since it won't
5668 * be sending any more data anyway.
5674 * Only send a WINDOW_ADJUST if there's significantly more window
5675 * available than the other end thinks there is. This saves us
5676 * sending a WINDOW_ADJUST for every character in a shell session.
5678 * "Significant" is arbitrarily defined as half the window size.
5680 if (newwin > c->v.v2.locwindow * 2) {
5681 struct Packet *pktout;
5683 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5684 ssh2_pkt_adduint32(pktout, c->remoteid);
5685 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
5686 ssh2_pkt_send(ssh, pktout);
5687 c->v.v2.locwindow = newwin;
5691 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
5693 unsigned i = ssh_pkt_getuint32(pktin);
5694 struct ssh_channel *c;
5695 c = find234(ssh->channels, &i, ssh_channelfind);
5696 if (c && !c->closes) {
5697 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
5698 ssh2_try_send_and_unthrottle(c);
5702 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
5706 unsigned i = ssh_pkt_getuint32(pktin);
5707 struct ssh_channel *c;
5708 c = find234(ssh->channels, &i, ssh_channelfind);
5710 return; /* nonexistent channel */
5711 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5712 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
5713 return; /* extended but not stderr */
5714 ssh_pkt_getstring(pktin, &data, &length);
5717 c->v.v2.locwindow -= length;
5719 case CHAN_MAINSESSION:
5721 from_backend(ssh->frontend, pktin->type ==
5722 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5726 bufsize = x11_send(c->u.x11.s, data, length);
5729 bufsize = pfd_send(c->u.pfd.s, data, length);
5732 while (length > 0) {
5733 if (c->u.a.lensofar < 4) {
5734 unsigned int l = min(4 - c->u.a.lensofar, length);
5735 memcpy(c->u.a.msglen + c->u.a.lensofar,
5739 c->u.a.lensofar += l;
5741 if (c->u.a.lensofar == 4) {
5743 4 + GET_32BIT(c->u.a.msglen);
5744 c->u.a.message = snewn(c->u.a.totallen,
5746 memcpy(c->u.a.message, c->u.a.msglen, 4);
5748 if (c->u.a.lensofar >= 4 && length > 0) {
5750 min(c->u.a.totallen - c->u.a.lensofar,
5752 memcpy(c->u.a.message + c->u.a.lensofar,
5756 c->u.a.lensofar += l;
5758 if (c->u.a.lensofar == c->u.a.totallen) {
5761 if (agent_query(c->u.a.message,
5764 ssh_agentf_callback, c))
5765 ssh_agentf_callback(c, reply, replylen);
5766 sfree(c->u.a.message);
5767 c->u.a.lensofar = 0;
5774 * If we are not buffering too much data,
5775 * enlarge the window again at the remote side.
5777 if (bufsize < OUR_V2_WINSIZE)
5778 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5782 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
5784 unsigned i = ssh_pkt_getuint32(pktin);
5785 struct ssh_channel *c;
5787 c = find234(ssh->channels, &i, ssh_channelfind);
5789 return; /* nonexistent channel */
5791 if (c->type == CHAN_X11) {
5793 * Remote EOF on an X11 channel means we should
5794 * wrap up and close the channel ourselves.
5796 x11_close(c->u.x11.s);
5798 } else if (c->type == CHAN_AGENT) {
5800 } else if (c->type == CHAN_SOCKDATA) {
5801 pfd_close(c->u.pfd.s);
5806 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
5808 unsigned i = ssh_pkt_getuint32(pktin);
5809 struct ssh_channel *c;
5810 struct Packet *pktout;
5812 c = find234(ssh->channels, &i, ssh_channelfind);
5813 if (!c || c->halfopen) {
5814 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5815 c ? "half-open" : "nonexistent", i));
5818 /* Do pre-close processing on the channel. */
5820 case CHAN_MAINSESSION:
5821 ssh->mainchan = NULL;
5822 update_specials_menu(ssh->frontend);
5825 if (c->u.x11.s != NULL)
5826 x11_close(c->u.x11.s);
5833 if (c->u.pfd.s != NULL)
5834 pfd_close(c->u.pfd.s);
5838 if (c->closes == 0) {
5839 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5840 ssh2_pkt_adduint32(pktout, c->remoteid);
5841 ssh2_pkt_send(ssh, pktout);
5843 del234(ssh->channels, c);
5844 bufchain_clear(&c->v.v2.outbuffer);
5848 * See if that was the last channel left open.
5849 * (This is only our termination condition if we're
5850 * not running in -N mode.)
5852 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
5853 logevent("All channels closed. Disconnecting");
5856 * We used to send SSH_MSG_DISCONNECT here,
5857 * because I'd believed that _every_ conforming
5858 * SSH-2 connection had to end with a disconnect
5859 * being sent by at least one side; apparently
5860 * I was wrong and it's perfectly OK to
5861 * unceremoniously slam the connection shut
5862 * when you're done, and indeed OpenSSH feels
5863 * this is more polite than sending a
5864 * DISCONNECT. So now we don't.
5866 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5867 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
5868 ssh2_pkt_addstring(s->pktout, "All open channels closed");
5869 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
5870 ssh2_pkt_send_noqueue(ssh, s->pktout);
5872 ssh->close_expected = TRUE;
5873 ssh_closing((Plug)ssh, NULL, 0, 0);
5877 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5879 unsigned i = ssh_pkt_getuint32(pktin);
5880 struct ssh_channel *c;
5881 struct Packet *pktout;
5883 c = find234(ssh->channels, &i, ssh_channelfind);
5885 return; /* nonexistent channel */
5886 if (c->type != CHAN_SOCKDATA_DORMANT)
5887 return; /* dunno why they're confirming this */
5888 c->remoteid = ssh_pkt_getuint32(pktin);
5889 c->halfopen = FALSE;
5890 c->type = CHAN_SOCKDATA;
5891 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
5892 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
5894 pfd_confirm(c->u.pfd.s);
5897 * We have a pending close on this channel,
5898 * which we decided on before the server acked
5899 * the channel open. So now we know the
5900 * remoteid, we can close it again.
5902 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5903 ssh2_pkt_adduint32(pktout, c->remoteid);
5904 ssh2_pkt_send(ssh, pktout);
5908 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5910 static const char *const reasons[] = {
5911 "<unknown reason code>",
5912 "Administratively prohibited",
5914 "Unknown channel type",
5915 "Resource shortage",
5917 unsigned i = ssh_pkt_getuint32(pktin);
5918 unsigned reason_code;
5919 char *reason_string;
5921 struct ssh_channel *c;
5922 c = find234(ssh->channels, &i, ssh_channelfind);
5924 return; /* nonexistent channel */
5925 if (c->type != CHAN_SOCKDATA_DORMANT)
5926 return; /* dunno why they're failing this */
5928 reason_code = ssh_pkt_getuint32(pktin);
5929 if (reason_code >= lenof(reasons))
5930 reason_code = 0; /* ensure reasons[reason_code] in range */
5931 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
5932 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
5933 reasons[reason_code], reason_length, reason_string);
5935 pfd_close(c->u.pfd.s);
5937 del234(ssh->channels, c);
5941 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
5945 int typelen, want_reply;
5946 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
5947 struct ssh_channel *c;
5948 struct Packet *pktout;
5950 localid = ssh_pkt_getuint32(pktin);
5951 ssh_pkt_getstring(pktin, &type, &typelen);
5952 want_reply = ssh2_pkt_getbool(pktin);
5955 * First, check that the channel exists. Otherwise,
5956 * we can instantly disconnect with a rude message.
5958 c = find234(ssh->channels, &localid, ssh_channelfind);
5961 sprintf(buf, "Received channel request for nonexistent"
5962 " channel %d", localid);
5964 pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5965 ssh2_pkt_adduint32(pktout, SSH2_DISCONNECT_BY_APPLICATION);
5966 ssh2_pkt_addstring(pktout, buf);
5967 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5968 ssh2_pkt_send_noqueue(ssh, pktout);
5969 connection_fatal(ssh->frontend, "%s", buf);
5970 ssh->close_expected = TRUE;
5971 ssh_closing((Plug)ssh, NULL, 0, 0);
5976 * Having got the channel number, we now look at
5977 * the request type string to see if it's something
5980 if (c == ssh->mainchan) {
5982 * We recognise "exit-status" and "exit-signal" on
5983 * the primary channel.
5985 if (typelen == 11 &&
5986 !memcmp(type, "exit-status", 11)) {
5988 ssh->exitcode = ssh_pkt_getuint32(pktin);
5989 logeventf(ssh, "Server sent command exit status %d",
5991 reply = SSH2_MSG_CHANNEL_SUCCESS;
5993 } else if (typelen == 11 &&
5994 !memcmp(type, "exit-signal", 11)) {
5996 int is_plausible = TRUE, is_int = FALSE;
5997 char *fmt_sig = "", *fmt_msg = "";
5999 int msglen = 0, core = FALSE;
6000 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
6001 * provide an `int' for the signal, despite its
6002 * having been a `string' in the drafts since at
6003 * least 2001. (Fixed in session.c 1.147.) Try to
6004 * infer which we can safely parse it as. */
6006 unsigned char *p = pktin->body +
6008 long len = pktin->length - pktin->savedpos;
6009 unsigned long num = GET_32BIT(p); /* what is it? */
6010 /* If it's 0, it hardly matters; assume string */
6014 int maybe_int = FALSE, maybe_str = FALSE;
6015 #define CHECK_HYPOTHESIS(offset, result) \
6018 if (q >= 0 && q+4 <= len) { \
6019 q = q + 4 + GET_32BIT(p+q); \
6020 if (q >= 0 && q+4 <= len && \
6021 ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
6025 CHECK_HYPOTHESIS(4+1, maybe_int);
6026 CHECK_HYPOTHESIS(4+num+1, maybe_str);
6027 #undef CHECK_HYPOTHESIS
6028 if (maybe_int && !maybe_str)
6030 else if (!maybe_int && maybe_str)
6033 /* Crikey. Either or neither. Panic. */
6034 is_plausible = FALSE;
6039 /* Old non-standard OpenSSH. */
6040 int signum = ssh_pkt_getuint32(pktin);
6041 fmt_sig = dupprintf(" %d", signum);
6043 /* As per the drafts. */
6046 ssh_pkt_getstring(pktin, &sig, &siglen);
6047 /* Signal name isn't supposed to be blank, but
6048 * let's cope gracefully if it is. */
6050 fmt_sig = dupprintf(" \"%.*s\"",
6054 core = ssh2_pkt_getbool(pktin);
6055 ssh_pkt_getstring(pktin, &msg, &msglen);
6057 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
6059 /* ignore lang tag */
6060 } /* else don't attempt to parse */
6061 logeventf(ssh, "Server exited on signal%s%s%s",
6062 fmt_sig, core ? " (core dumped)" : "",
6064 if (*fmt_sig) sfree(fmt_sig);
6065 if (*fmt_msg) sfree(fmt_msg);
6066 reply = SSH2_MSG_CHANNEL_SUCCESS;
6071 * This is a channel request we don't know
6072 * about, so we now either ignore the request
6073 * or respond with CHANNEL_FAILURE, depending
6076 reply = SSH2_MSG_CHANNEL_FAILURE;
6079 pktout = ssh2_pkt_init(reply);
6080 ssh2_pkt_adduint32(pktout, c->remoteid);
6081 ssh2_pkt_send(ssh, pktout);
6085 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
6088 int typelen, want_reply;
6089 struct Packet *pktout;
6091 ssh_pkt_getstring(pktin, &type, &typelen);
6092 want_reply = ssh2_pkt_getbool(pktin);
6095 * We currently don't support any global requests
6096 * at all, so we either ignore the request or
6097 * respond with REQUEST_FAILURE, depending on
6101 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
6102 ssh2_pkt_send(ssh, pktout);
6106 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
6114 struct ssh_channel *c;
6115 unsigned remid, winsize, pktsize;
6116 struct Packet *pktout;
6118 ssh_pkt_getstring(pktin, &type, &typelen);
6119 c = snew(struct ssh_channel);
6122 remid = ssh_pkt_getuint32(pktin);
6123 winsize = ssh_pkt_getuint32(pktin);
6124 pktsize = ssh_pkt_getuint32(pktin);
6126 if (typelen == 3 && !memcmp(type, "x11", 3)) {
6129 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6130 addrstr = snewn(peeraddrlen+1, char);
6131 memcpy(addrstr, peeraddr, peeraddrlen);
6132 addrstr[peeraddrlen] = '\0';
6133 peerport = ssh_pkt_getuint32(pktin);
6135 logeventf(ssh, "Received X11 connect request from %s:%d",
6138 if (!ssh->X11_fwd_enabled)
6139 error = "X11 forwarding is not enabled";
6140 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
6141 ssh->x11auth, addrstr, peerport,
6142 &ssh->cfg) != NULL) {
6143 error = "Unable to open an X11 connection";
6145 logevent("Opening X11 forward connection succeeded");
6150 } else if (typelen == 15 &&
6151 !memcmp(type, "forwarded-tcpip", 15)) {
6152 struct ssh_rportfwd pf, *realpf;
6155 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
6156 pf.sport = ssh_pkt_getuint32(pktin);
6157 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6158 peerport = ssh_pkt_getuint32(pktin);
6159 realpf = find234(ssh->rportfwds, &pf, NULL);
6160 logeventf(ssh, "Received remote port %d open request "
6161 "from %s:%d", pf.sport, peeraddr, peerport);
6162 if (realpf == NULL) {
6163 error = "Remote port is not recognised";
6165 const char *e = pfd_newconnect(&c->u.pfd.s,
6169 realpf->pfrec->addressfamily);
6170 logeventf(ssh, "Attempting to forward remote port to "
6171 "%s:%d", realpf->dhost, realpf->dport);
6173 logeventf(ssh, "Port open failed: %s", e);
6174 error = "Port open failed";
6176 logevent("Forwarded port opened successfully");
6177 c->type = CHAN_SOCKDATA;
6180 } else if (typelen == 22 &&
6181 !memcmp(type, "auth-agent@openssh.com", 3)) {
6182 if (!ssh->agentfwd_enabled)
6183 error = "Agent forwarding is not enabled";
6185 c->type = CHAN_AGENT; /* identify channel type */
6186 c->u.a.lensofar = 0;
6189 error = "Unsupported channel type requested";
6192 c->remoteid = remid;
6193 c->halfopen = FALSE;
6195 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
6196 ssh2_pkt_adduint32(pktout, c->remoteid);
6197 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
6198 ssh2_pkt_addstring(pktout, error);
6199 ssh2_pkt_addstring(pktout, "en"); /* language tag */
6200 ssh2_pkt_send(ssh, pktout);
6201 logeventf(ssh, "Rejected channel open: %s", error);
6204 c->localid = alloc_channel_id(ssh);
6206 c->v.v2.locwindow = OUR_V2_WINSIZE;
6207 c->v.v2.remwindow = winsize;
6208 c->v.v2.remmaxpkt = pktsize;
6209 bufchain_init(&c->v.v2.outbuffer);
6210 add234(ssh->channels, c);
6211 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
6212 ssh2_pkt_adduint32(pktout, c->remoteid);
6213 ssh2_pkt_adduint32(pktout, c->localid);
6214 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
6215 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
6216 ssh2_pkt_send(ssh, pktout);
6221 * Handle the SSH-2 userauth and connection layers.
6223 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
6224 struct Packet *pktin)
6226 struct do_ssh2_authconn_state {
6228 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
6230 AUTH_KEYBOARD_INTERACTIVE
6234 AUTH_TYPE_PUBLICKEY,
6235 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
6236 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
6238 AUTH_TYPE_KEYBOARD_INTERACTIVE,
6239 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
6241 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
6242 int tried_pubkey_config, tried_agent;
6243 int kbd_inter_running, kbd_inter_refused;
6245 int num_prompts, curr_prompt, echo;
6250 void *publickey_blob;
6251 int publickey_bloblen;
6252 unsigned char request[5], *response, *p;
6256 char *pkblob, *alg, *commentp;
6257 int pklen, alglen, commentlen;
6258 int siglen, retlen, len;
6259 char *q, *agentreq, *ret;
6261 int num_env, env_left, env_ok;
6262 struct Packet *pktout;
6264 crState(do_ssh2_authconn_state);
6266 crBegin(ssh->do_ssh2_authconn_crstate);
6269 * Request userauth protocol, and await a response to it.
6271 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6272 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
6273 ssh2_pkt_send(ssh, s->pktout);
6274 crWaitUntilV(pktin);
6275 if (pktin->type != SSH2_MSG_SERVICE_ACCEPT) {
6276 bombout(("Server refused user authentication protocol"));
6281 * We repeat this whole loop, including the username prompt,
6282 * until we manage a successful authentication. If the user
6283 * types the wrong _password_, they can be sent back to the
6284 * beginning to try another username, if this is configured on.
6285 * (If they specify a username in the config, they are never
6286 * asked, even if they do give a wrong password.)
6288 * I think this best serves the needs of
6290 * - the people who have no configuration, no keys, and just
6291 * want to try repeated (username,password) pairs until they
6292 * type both correctly
6294 * - people who have keys and configuration but occasionally
6295 * need to fall back to passwords
6297 * - people with a key held in Pageant, who might not have
6298 * logged in to a particular machine before; so they want to
6299 * type a username, and then _either_ their key will be
6300 * accepted, _or_ they will type a password. If they mistype
6301 * the username they will want to be able to get back and
6304 s->username[0] = '\0';
6305 s->got_username = FALSE;
6310 if (s->got_username && !ssh->cfg.change_username) {
6312 * We got a username last time round this loop, and
6313 * with change_username turned off we don't try to get
6316 } else if (!*ssh->cfg.username) {
6317 if (ssh_get_line && !ssh_getline_pw_only) {
6318 if (!ssh_get_line("login as: ",
6319 s->username, sizeof(s->username), FALSE)) {
6321 * get_line failed to get a username.
6324 logevent("No username provided. Abandoning session.");
6325 ssh->close_expected = TRUE;
6326 ssh_closing((Plug)ssh, NULL, 0, 0);
6330 int ret; /* need not be saved across crReturn */
6331 c_write_str(ssh, "login as: ");
6333 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
6335 crWaitUntilV(!pktin);
6336 ret = process_userpass_input(ssh, in, inlen);
6340 c_write_str(ssh, "\r\n");
6342 s->username[strcspn(s->username, "\n\r")] = '\0';
6345 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
6346 s->username[sizeof(s->username)-1] = '\0';
6347 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
6348 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
6349 c_write_str(ssh, stuff);
6353 s->got_username = TRUE;
6356 * Send an authentication request using method "none": (a)
6357 * just in case it succeeds, and (b) so that we know what
6358 * authentication methods we can usefully try next.
6360 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6362 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6363 ssh2_pkt_addstring(s->pktout, s->username);
6364 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
6365 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6366 ssh2_pkt_send(ssh, s->pktout);
6367 s->type = AUTH_TYPE_NONE;
6369 s->we_are_in = FALSE;
6371 s->tried_pubkey_config = FALSE;
6372 s->tried_agent = FALSE;
6373 s->kbd_inter_running = FALSE;
6374 s->kbd_inter_refused = FALSE;
6375 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
6376 if (!filename_is_null(ssh->cfg.keyfile)) {
6378 logeventf(ssh, "Reading private key file \"%.150s\"",
6379 filename_to_str(&ssh->cfg.keyfile));
6380 keytype = key_type(&ssh->cfg.keyfile);
6381 if (keytype == SSH_KEYTYPE_SSH2) {
6383 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
6384 &s->publickey_bloblen, NULL);
6387 logeventf(ssh, "Unable to use this key file (%s)",
6388 key_type_to_str(keytype));
6389 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6391 filename_to_str(&ssh->cfg.keyfile),
6392 key_type_to_str(keytype));
6393 c_write_str(ssh, msgbuf);
6395 s->publickey_blob = NULL;
6398 s->publickey_blob = NULL;
6402 * Wait for the result of the last authentication request.
6405 crWaitUntilV(pktin);
6406 while (pktin->type == SSH2_MSG_USERAUTH_BANNER) {
6410 * Don't show the banner if we're operating in
6411 * non-verbose non-interactive mode. (It's probably
6412 * a script, which means nobody will read the
6413 * banner _anyway_, and moreover the printing of
6414 * the banner will screw up processing on the
6415 * output of (say) plink.)
6417 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
6418 ssh_pkt_getstring(pktin, &banner, &size);
6420 c_write_untrusted(ssh, banner, size);
6422 crWaitUntilV(pktin);
6424 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
6425 logevent("Access granted");
6426 s->we_are_in = TRUE;
6430 if (s->kbd_inter_running &&
6431 pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
6433 * This is either a further set-of-prompts packet
6434 * in keyboard-interactive authentication, or it's
6435 * the same one and we came back here with `gotit'
6436 * set. In the former case, we must reset the
6437 * curr_prompt variable.
6441 } else if (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
6442 /* FIXME: perhaps we should support this? */
6443 bombout(("PASSWD_CHANGEREQ not yet supported"));
6445 } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
6446 bombout(("Strange packet received during authentication: type %d",
6454 * OK, we're now sitting on a USERAUTH_FAILURE message, so
6455 * we can look at the string in it and know what we can
6456 * helpfully try next.
6458 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
6461 ssh_pkt_getstring(pktin, &methods, &methlen);
6462 s->kbd_inter_running = FALSE;
6463 if (!ssh2_pkt_getbool(pktin)) {
6465 * We have received an unequivocal Access
6466 * Denied. This can translate to a variety of
6469 * - if we'd just tried "none" authentication,
6470 * it's not worth printing anything at all
6472 * - if we'd just tried a public key _offer_,
6473 * the message should be "Server refused our
6474 * key" (or no message at all if the key
6475 * came from Pageant)
6477 * - if we'd just tried anything else, the
6478 * message really should be "Access denied".
6480 * Additionally, if we'd just tried password
6481 * authentication, we should break out of this
6482 * whole loop so as to go back to the username
6483 * prompt (iff we're configured to allow
6484 * username change attempts).
6486 if (s->type == AUTH_TYPE_NONE) {
6488 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
6489 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
6490 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
6491 c_write_str(ssh, "Server refused our key\r\n");
6492 logevent("Server refused public key");
6493 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
6494 /* server declined keyboard-interactive; ignore */
6496 c_write_str(ssh, "Access denied\r\n");
6497 logevent("Access denied");
6498 if (s->type == AUTH_TYPE_PASSWORD &&
6499 ssh->cfg.change_username) {
6500 /* XXX perhaps we should allow
6501 * keyboard-interactive to do this too? */
6502 s->we_are_in = FALSE;
6507 c_write_str(ssh, "Further authentication required\r\n");
6508 logevent("Further authentication required");
6512 in_commasep_string("publickey", methods, methlen);
6514 in_commasep_string("password", methods, methlen);
6515 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
6516 in_commasep_string("keyboard-interactive", methods, methlen);
6520 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6524 * Most password/passphrase prompts will be
6525 * non-echoing, so we set this to 0 by default.
6526 * Exception is that some keyboard-interactive prompts
6527 * can be echoing, in which case we'll set this to 1.
6531 if (!s->method && s->can_pubkey &&
6532 agent_exists() && !s->tried_agent) {
6534 * Attempt public-key authentication using Pageant.
6539 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6540 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6542 s->tried_agent = TRUE;
6544 logevent("Pageant is running. Requesting keys.");
6546 /* Request the keys held by the agent. */
6547 PUT_32BIT(s->request, 1);
6548 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
6549 if (!agent_query(s->request, 5, &r, &s->responselen,
6550 ssh_agent_callback, ssh)) {
6554 bombout(("Unexpected data from server while"
6555 " waiting for agent response"));
6558 } while (pktin || inlen > 0);
6559 r = ssh->agent_response;
6560 s->responselen = ssh->agent_response_len;
6562 s->response = (unsigned char *) r;
6563 if (s->response && s->responselen >= 5 &&
6564 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
6565 s->p = s->response + 5;
6566 s->nkeys = GET_32BIT(s->p);
6568 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
6569 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
6572 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
6573 s->pklen = GET_32BIT(s->p);
6575 if (s->publickey_blob &&
6576 s->pklen == s->publickey_bloblen &&
6577 !memcmp(s->p, s->publickey_blob,
6578 s->publickey_bloblen)) {
6579 logevent("This key matches configured key file");
6580 s->tried_pubkey_config = 1;
6582 s->pkblob = (char *)s->p;
6584 s->alglen = GET_32BIT(s->pkblob);
6585 s->alg = s->pkblob + 4;
6586 s->commentlen = GET_32BIT(s->p);
6588 s->commentp = (char *)s->p;
6589 s->p += s->commentlen;
6590 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6591 ssh2_pkt_addstring(s->pktout, s->username);
6592 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6593 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6594 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6595 ssh2_pkt_addstring_start(s->pktout);
6596 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6597 ssh2_pkt_addstring_start(s->pktout);
6598 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6599 ssh2_pkt_send(ssh, s->pktout);
6601 crWaitUntilV(pktin);
6602 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6603 logevent("Key refused");
6607 if (flags & FLAG_VERBOSE) {
6608 c_write_str(ssh, "Authenticating with "
6610 c_write(ssh, s->commentp, s->commentlen);
6611 c_write_str(ssh, "\" from agent\r\n");
6615 * Server is willing to accept the key.
6616 * Construct a SIGN_REQUEST.
6618 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6619 ssh2_pkt_addstring(s->pktout, s->username);
6620 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6621 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6622 ssh2_pkt_addbool(s->pktout, TRUE);
6623 ssh2_pkt_addstring_start(s->pktout);
6624 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6625 ssh2_pkt_addstring_start(s->pktout);
6626 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6628 s->siglen = s->pktout->length - 5 + 4 + 20;
6629 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6631 s->len = 1; /* message type */
6632 s->len += 4 + s->pklen; /* key blob */
6633 s->len += 4 + s->siglen; /* data to sign */
6634 s->len += 4; /* flags */
6635 s->agentreq = snewn(4 + s->len, char);
6636 PUT_32BIT(s->agentreq, s->len);
6637 s->q = s->agentreq + 4;
6638 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
6639 PUT_32BIT(s->q, s->pklen);
6641 memcpy(s->q, s->pkblob, s->pklen);
6643 PUT_32BIT(s->q, s->siglen);
6645 /* Now the data to be signed... */
6646 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6647 PUT_32BIT(s->q, 20);
6650 memcpy(s->q, ssh->v2_session_id, 20);
6652 memcpy(s->q, s->pktout->data + 5,
6653 s->pktout->length - 5);
6654 s->q += s->pktout->length - 5;
6655 /* And finally the (zero) flags word. */
6657 if (!agent_query(s->agentreq, s->len + 4,
6659 ssh_agent_callback, ssh)) {
6663 bombout(("Unexpected data from server"
6664 " while waiting for agent"
6668 } while (pktin || inlen > 0);
6669 vret = ssh->agent_response;
6670 s->retlen = ssh->agent_response_len;
6675 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
6676 logevent("Sending Pageant's response");
6677 ssh2_add_sigblob(ssh, s->pktout,
6678 s->pkblob, s->pklen,
6680 GET_32BIT(s->ret + 5));
6681 ssh2_pkt_send(ssh, s->pktout);
6686 ("Pageant failed to answer challenge");
6697 if (!s->method && s->can_pubkey && s->publickey_blob
6698 && !s->tried_pubkey_config) {
6699 unsigned char *pub_blob;
6700 char *algorithm, *comment;
6703 s->tried_pubkey_config = TRUE;
6705 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6706 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6709 * Try the public key supplied in the configuration.
6711 * First, offer the public blob to see if the server is
6712 * willing to accept it.
6715 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
6720 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6721 ssh2_pkt_addstring(s->pktout, s->username);
6722 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6723 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6724 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6725 ssh2_pkt_addstring(s->pktout, algorithm);
6726 ssh2_pkt_addstring_start(s->pktout);
6727 ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob,
6729 ssh2_pkt_send(ssh, s->pktout);
6730 logevent("Offered public key");
6732 crWaitUntilV(pktin);
6733 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6735 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
6736 continue; /* key refused; give up on it */
6739 logevent("Offer of public key accepted");
6741 * Actually attempt a serious authentication using
6744 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
6745 sprintf(s->pwprompt,
6746 "Passphrase for key \"%.100s\": ",
6752 if (flags & FLAG_VERBOSE) {
6753 c_write_str(ssh, "Authenticating with public key \"");
6754 c_write_str(ssh, comment);
6755 c_write_str(ssh, "\"\r\n");
6757 s->method = AUTH_PUBLICKEY_FILE;
6761 if (!s->method && s->can_keyb_inter && !s->kbd_inter_refused &&
6762 !s->kbd_inter_running) {
6763 s->method = AUTH_KEYBOARD_INTERACTIVE;
6764 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6766 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6767 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
6769 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6770 ssh2_pkt_addstring(s->pktout, s->username);
6771 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6772 ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); /* method */
6773 ssh2_pkt_addstring(s->pktout, ""); /* lang */
6774 ssh2_pkt_addstring(s->pktout, "");
6775 ssh2_pkt_send(ssh, s->pktout);
6777 crWaitUntilV(pktin);
6778 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
6779 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
6781 logevent("Keyboard-interactive authentication refused");
6782 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
6783 s->kbd_inter_refused = TRUE; /* don't try it again */
6787 c_write_str(ssh, "Using keyboard-interactive authentication.\r\n");
6788 s->kbd_inter_running = TRUE;
6792 if (s->kbd_inter_running) {
6793 s->method = AUTH_KEYBOARD_INTERACTIVE;
6794 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6796 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6797 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
6799 if (s->curr_prompt == 0) {
6801 * We've got a fresh USERAUTH_INFO_REQUEST.
6802 * Display header data, and start going through
6805 char *name, *inst, *lang;
6806 int name_len, inst_len, lang_len;
6808 ssh_pkt_getstring(pktin, &name, &name_len);
6809 ssh_pkt_getstring(pktin, &inst, &inst_len);
6810 ssh_pkt_getstring(pktin, &lang, &lang_len);
6812 c_write_untrusted(ssh, name, name_len);
6813 c_write_str(ssh, "\r\n");
6816 c_write_untrusted(ssh, inst, inst_len);
6817 c_write_str(ssh, "\r\n");
6819 s->num_prompts = ssh_pkt_getuint32(pktin);
6823 * If there are prompts remaining in the packet,
6824 * display one and get a response.
6826 if (s->curr_prompt < s->num_prompts) {
6830 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
6831 if (prompt_len > 0) {
6832 static const char trunc[] = "<prompt truncated>: ";
6833 static const int prlen = sizeof(s->pwprompt) -
6835 if (prompt_len > prlen) {
6836 memcpy(s->pwprompt, prompt, prlen);
6837 strcpy(s->pwprompt + prlen, trunc);
6839 memcpy(s->pwprompt, prompt, prompt_len);
6840 s->pwprompt[prompt_len] = '\0';
6844 "<server failed to send prompt>: ");
6846 s->echo = ssh2_pkt_getbool(pktin);
6852 if (!s->method && s->can_passwd) {
6853 s->method = AUTH_PASSWORD;
6854 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6855 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
6856 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
6863 if (!ssh_get_line(s->pwprompt, s->password,
6864 sizeof(s->password), TRUE)) {
6866 * get_line failed to get a password (for
6867 * example because one was supplied on the
6868 * command line which has already failed to
6871 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6872 ssh2_pkt_adduint32(s->pktout,SSH2_DISCONNECT_BY_APPLICATION);
6873 ssh2_pkt_addstring(s->pktout, "No more passwords available"
6875 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
6876 ssh2_pkt_send_noqueue(ssh, s->pktout);
6877 logevent("Unable to authenticate");
6878 connection_fatal(ssh->frontend,
6879 "Unable to authenticate");
6880 ssh->close_expected = TRUE;
6881 ssh_closing((Plug)ssh, NULL, 0, 0);
6885 int ret; /* need not be saved across crReturn */
6886 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
6889 setup_userpass_input(ssh, s->password,
6890 sizeof(s->password), s->echo);
6892 crWaitUntilV(!pktin);
6893 ret = process_userpass_input(ssh, in, inlen);
6897 c_write_str(ssh, "\r\n");
6901 if (s->method == AUTH_PUBLICKEY_FILE) {
6903 * We have our passphrase. Now try the actual authentication.
6905 struct ssh2_userkey *key;
6906 const char *error = NULL;
6908 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
6910 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
6911 if (key == SSH2_WRONG_PASSPHRASE) {
6912 c_write_str(ssh, "Wrong passphrase\r\n");
6913 s->tried_pubkey_config = FALSE;
6915 c_write_str(ssh, "Unable to load private key (");
6916 c_write_str(ssh, error);
6917 c_write_str(ssh, ")\r\n");
6918 s->tried_pubkey_config = TRUE;
6920 /* Send a spurious AUTH_NONE to return to the top. */
6921 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6922 ssh2_pkt_addstring(s->pktout, s->username);
6923 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6924 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6925 ssh2_pkt_send(ssh, s->pktout);
6926 s->type = AUTH_TYPE_NONE;
6928 unsigned char *pkblob, *sigblob, *sigdata;
6929 int pkblob_len, sigblob_len, sigdata_len;
6933 * We have loaded the private key and the server
6934 * has announced that it's willing to accept it.
6935 * Hallelujah. Generate a signature and send it.
6937 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6938 ssh2_pkt_addstring(s->pktout, s->username);
6939 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6940 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6941 ssh2_pkt_addbool(s->pktout, TRUE);
6942 ssh2_pkt_addstring(s->pktout, key->alg->name);
6943 pkblob = key->alg->public_blob(key->data, &pkblob_len);
6944 ssh2_pkt_addstring_start(s->pktout);
6945 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len);
6948 * The data to be signed is:
6952 * followed by everything so far placed in the
6955 sigdata_len = s->pktout->length - 5 + 4 + 20;
6956 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6958 sigdata = snewn(sigdata_len, unsigned char);
6960 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6961 PUT_32BIT(sigdata+p, 20);
6964 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
6965 memcpy(sigdata+p, s->pktout->data + 5,
6966 s->pktout->length - 5);
6967 p += s->pktout->length - 5;
6968 assert(p == sigdata_len);
6969 sigblob = key->alg->sign(key->data, (char *)sigdata,
6970 sigdata_len, &sigblob_len);
6971 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
6972 sigblob, sigblob_len);
6977 ssh2_pkt_send(ssh, s->pktout);
6978 s->type = AUTH_TYPE_PUBLICKEY;
6979 key->alg->freekey(key->data);
6981 } else if (s->method == AUTH_PASSWORD) {
6983 * We pad out the password packet to 256 bytes to make
6984 * it harder for an attacker to find the length of the
6987 * Anyone using a password longer than 256 bytes
6988 * probably doesn't have much to worry about from
6989 * people who find out how long their password is!
6991 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6992 s->pktout->forcepad = 256;
6993 ssh2_pkt_addstring(s->pktout, s->username);
6994 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6995 ssh2_pkt_addstring(s->pktout, "password");
6996 ssh2_pkt_addbool(s->pktout, FALSE);
6997 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6998 ssh2_pkt_addstring(s->pktout, s->password);
6999 memset(s->password, 0, sizeof(s->password));
7000 end_log_omission(ssh, s->pktout);
7001 ssh2_pkt_send(ssh, s->pktout);
7002 logevent("Sent password");
7003 s->type = AUTH_TYPE_PASSWORD;
7004 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
7005 if (s->curr_prompt == 0) {
7006 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
7007 s->pktout->forcepad = 256;
7008 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
7010 if (s->need_pw) { /* only add pw if we just got one! */
7011 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7012 ssh2_pkt_addstring(s->pktout, s->password);
7013 memset(s->password, 0, sizeof(s->password));
7014 end_log_omission(ssh, s->pktout);
7017 if (s->curr_prompt >= s->num_prompts) {
7018 ssh2_pkt_send(ssh, s->pktout);
7021 * If there are prompts remaining, we set
7022 * `gotit' so that we won't attempt to get
7023 * another packet. Then we go back round the
7024 * loop and will end up retrieving another
7025 * prompt out of the existing packet. Funky or
7030 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
7032 c_write_str(ssh, "No supported authentication methods"
7033 " left to try!\r\n");
7034 logevent("No supported authentications offered."
7036 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
7037 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
7038 ssh2_pkt_addstring(s->pktout, "No supported authentication"
7039 " methods available");
7040 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
7041 ssh2_pkt_send_noqueue(ssh, s->pktout);
7042 ssh->close_expected = TRUE;
7043 ssh_closing((Plug)ssh, NULL, 0, 0);
7047 } while (!s->we_are_in);
7050 * Now we're authenticated for the connection protocol. The
7051 * connection protocol will automatically have started at this
7052 * point; there's no need to send SERVICE_REQUEST.
7055 ssh->channels = newtree234(ssh_channelcmp);
7058 * Set up handlers for some connection protocol messages, so we
7059 * don't have to handle them repeatedly in this coroutine.
7061 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
7062 ssh2_msg_channel_window_adjust;
7063 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
7064 ssh2_msg_global_request;
7067 * Create the main session channel.
7069 if (!ssh->cfg.ssh_no_shell) {
7070 ssh->mainchan = snew(struct ssh_channel);
7071 ssh->mainchan->ssh = ssh;
7072 ssh->mainchan->localid = alloc_channel_id(ssh);
7073 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7074 ssh2_pkt_addstring(s->pktout, "session");
7075 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
7076 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
7077 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
7078 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
7079 ssh2_pkt_send(ssh, s->pktout);
7080 crWaitUntilV(pktin);
7081 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
7082 bombout(("Server refused to open a session"));
7084 /* FIXME: error data comes back in FAILURE packet */
7086 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
7087 bombout(("Server's channel confirmation cited wrong channel"));
7090 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
7091 ssh->mainchan->halfopen = FALSE;
7092 ssh->mainchan->type = CHAN_MAINSESSION;
7093 ssh->mainchan->closes = 0;
7094 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7095 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7096 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
7097 add234(ssh->channels, ssh->mainchan);
7098 update_specials_menu(ssh->frontend);
7099 logevent("Opened channel for session");
7101 ssh->mainchan = NULL;
7104 * Now we have a channel, make dispatch table entries for
7105 * general channel-based messages.
7107 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
7108 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
7109 ssh2_msg_channel_data;
7110 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
7111 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
7112 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
7113 ssh2_msg_channel_open_confirmation;
7114 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
7115 ssh2_msg_channel_open_failure;
7116 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
7117 ssh2_msg_channel_request;
7118 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
7119 ssh2_msg_channel_open;
7122 * Potentially enable X11 forwarding.
7124 if (ssh->mainchan && ssh->cfg.x11_forward) {
7125 char proto[20], data[64];
7126 logevent("Requesting X11 forwarding");
7127 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
7128 data, sizeof(data), ssh->cfg.x11_auth);
7129 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
7130 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7131 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7132 ssh2_pkt_addstring(s->pktout, "x11-req");
7133 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7134 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
7135 ssh2_pkt_addstring(s->pktout, proto);
7136 ssh2_pkt_addstring(s->pktout, data);
7137 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
7138 ssh2_pkt_send(ssh, s->pktout);
7140 crWaitUntilV(pktin);
7142 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7143 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7144 bombout(("Unexpected response to X11 forwarding request:"
7145 " packet type %d", pktin->type));
7148 logevent("X11 forwarding refused");
7150 logevent("X11 forwarding enabled");
7151 ssh->X11_fwd_enabled = TRUE;
7156 * Enable port forwardings.
7158 ssh_setup_portfwd(ssh, &ssh->cfg);
7161 * Potentially enable agent forwarding.
7163 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
7164 logevent("Requesting OpenSSH-style agent forwarding");
7165 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7166 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7167 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
7168 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7169 ssh2_pkt_send(ssh, s->pktout);
7171 crWaitUntilV(pktin);
7173 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7174 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7175 bombout(("Unexpected response to agent forwarding request:"
7176 " packet type %d", pktin->type));
7179 logevent("Agent forwarding refused");
7181 logevent("Agent forwarding enabled");
7182 ssh->agentfwd_enabled = TRUE;
7187 * Now allocate a pty for the session.
7189 if (ssh->mainchan && !ssh->cfg.nopty) {
7190 /* Unpick the terminal-speed string. */
7191 /* XXX perhaps we should allow no speeds to be sent. */
7192 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
7193 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
7194 /* Build the pty request. */
7195 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7196 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
7197 ssh2_pkt_addstring(s->pktout, "pty-req");
7198 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7199 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
7200 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
7201 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
7202 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
7203 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
7204 ssh2_pkt_addstring_start(s->pktout);
7205 ssh2_pkt_addbyte(s->pktout, 128); /* TTY_OP_ISPEED */
7206 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
7207 ssh2_pkt_addbyte(s->pktout, 129); /* TTY_OP_OSPEED */
7208 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
7209 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
7210 ssh2_pkt_send(ssh, s->pktout);
7211 ssh->state = SSH_STATE_INTERMED;
7213 crWaitUntilV(pktin);
7215 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7216 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7217 bombout(("Unexpected response to pty request:"
7218 " packet type %d", pktin->type));
7221 c_write_str(ssh, "Server refused to allocate pty\r\n");
7222 ssh->editing = ssh->echoing = 1;
7224 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
7225 ssh->ospeed, ssh->ispeed);
7228 ssh->editing = ssh->echoing = 1;
7232 * Send environment variables.
7234 * Simplest thing here is to send all the requests at once, and
7235 * then wait for a whole bunch of successes or failures.
7237 if (ssh->mainchan && *ssh->cfg.environmt) {
7238 char *e = ssh->cfg.environmt;
7239 char *var, *varend, *val;
7245 while (*e && *e != '\t') e++;
7247 if (*e == '\t') e++;
7252 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7253 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7254 ssh2_pkt_addstring(s->pktout, "env");
7255 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7256 ssh2_pkt_addstring_start(s->pktout);
7257 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
7258 ssh2_pkt_addstring(s->pktout, val);
7259 ssh2_pkt_send(ssh, s->pktout);
7264 logeventf(ssh, "Sent %d environment variables", s->num_env);
7267 s->env_left = s->num_env;
7269 while (s->env_left > 0) {
7270 crWaitUntilV(pktin);
7272 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7273 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7274 bombout(("Unexpected response to environment request:"
7275 " packet type %d", pktin->type));
7285 if (s->env_ok == s->num_env) {
7286 logevent("All environment variables successfully set");
7287 } else if (s->env_ok == 0) {
7288 logevent("All environment variables refused");
7289 c_write_str(ssh, "Server refused to set environment variables\r\n");
7291 logeventf(ssh, "%d environment variables refused",
7292 s->num_env - s->env_ok);
7293 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7298 * Start a shell or a remote command. We may have to attempt
7299 * this twice if the config data has provided a second choice
7302 if (ssh->mainchan) while (1) {
7306 if (ssh->fallback_cmd) {
7307 subsys = ssh->cfg.ssh_subsys2;
7308 cmd = ssh->cfg.remote_cmd_ptr2;
7310 subsys = ssh->cfg.ssh_subsys;
7311 cmd = ssh->cfg.remote_cmd_ptr;
7312 if (!cmd) cmd = ssh->cfg.remote_cmd;
7315 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7316 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
7318 ssh2_pkt_addstring(s->pktout, "subsystem");
7319 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7320 ssh2_pkt_addstring(s->pktout, cmd);
7322 ssh2_pkt_addstring(s->pktout, "exec");
7323 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7324 ssh2_pkt_addstring(s->pktout, cmd);
7326 ssh2_pkt_addstring(s->pktout, "shell");
7327 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7329 ssh2_pkt_send(ssh, s->pktout);
7331 crWaitUntilV(pktin);
7333 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7334 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7335 bombout(("Unexpected response to shell/command request:"
7336 " packet type %d", pktin->type));
7340 * We failed to start the command. If this is the
7341 * fallback command, we really are finished; if it's
7342 * not, and if the fallback command exists, try falling
7343 * back to it before complaining.
7345 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
7346 logevent("Primary command failed; attempting fallback");
7347 ssh->fallback_cmd = TRUE;
7350 bombout(("Server refused to start a shell/command"));
7353 logevent("Started a shell/command");
7358 ssh->state = SSH_STATE_SESSION;
7359 if (ssh->size_needed)
7360 ssh_size(ssh, ssh->term_width, ssh->term_height);
7361 if (ssh->eof_needed)
7362 ssh_special(ssh, TS_EOF);
7368 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
7373 s->try_send = FALSE;
7377 * _All_ the connection-layer packets we expect to
7378 * receive are now handled by the dispatch table.
7379 * Anything that reaches here must be bogus.
7382 bombout(("Strange packet received: type %d", pktin->type));
7384 } else if (ssh->mainchan) {
7386 * We have spare data. Add it to the channel buffer.
7388 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
7393 struct ssh_channel *c;
7395 * Try to send data on all channels if we can.
7397 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
7398 ssh2_try_send_and_unthrottle(c);
7406 * Handlers for SSH-2 messages that might arrive at any moment.
7408 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
7410 /* log reason code in disconnect message */
7412 int nowlen, reason, msglen;
7414 reason = ssh_pkt_getuint32(pktin);
7415 ssh_pkt_getstring(pktin, &msg, &msglen);
7417 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
7418 buf = dupprintf("Received disconnect message (%s)",
7419 ssh2_disconnect_reasons[reason]);
7421 buf = dupprintf("Received disconnect message (unknown"
7422 " type %d)", reason);
7426 buf = dupprintf("Disconnection message text: %n%.*s",
7427 &nowlen, msglen, msg);
7429 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
7431 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
7432 ssh2_disconnect_reasons[reason] : "unknown",
7437 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
7439 /* log the debug message */
7444 /* XXX maybe we should actually take notice of this */
7445 always_display = ssh2_pkt_getbool(pktin);
7446 ssh_pkt_getstring(pktin, &msg, &msglen);
7448 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
7451 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
7453 struct Packet *pktout;
7454 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
7455 ssh2_pkt_adduint32(pktout, pktin->sequence);
7457 * UNIMPLEMENTED messages MUST appear in the same order as the
7458 * messages they respond to. Hence, never queue them.
7460 ssh2_pkt_send_noqueue(ssh, pktout);
7464 * Handle the top-level SSH-2 protocol.
7466 static void ssh2_protocol_setup(Ssh ssh)
7471 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
7473 for (i = 0; i < 256; i++)
7474 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
7477 * Any message we actually understand, we set to NULL so that
7478 * the coroutines will get it.
7480 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
7481 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
7482 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
7483 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
7484 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
7485 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
7486 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
7487 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
7488 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
7489 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
7490 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
7491 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
7492 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
7493 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
7494 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7495 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
7496 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
7497 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
7498 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
7499 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
7500 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
7501 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
7502 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
7503 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
7504 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
7505 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
7506 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
7507 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
7508 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
7509 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
7510 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
7511 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
7512 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
7515 * These special message types we install handlers for.
7517 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
7518 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
7519 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
7522 static void ssh2_timer(void *ctx, long now)
7526 if (ssh->state == SSH_STATE_CLOSED)
7529 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
7530 now - ssh->next_rekey >= 0) {
7531 do_ssh2_transport(ssh, "timeout", -1, NULL);
7535 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
7536 struct Packet *pktin)
7538 unsigned char *in = (unsigned char *)vin;
7539 if (ssh->state == SSH_STATE_CLOSED)
7543 ssh->incoming_data_size += pktin->encrypted_len;
7544 if (!ssh->kex_in_progress &&
7545 ssh->max_data_size != 0 &&
7546 ssh->incoming_data_size > ssh->max_data_size)
7547 do_ssh2_transport(ssh, "too much data received", -1, NULL);
7550 if (pktin && ssh->packet_dispatch[pktin->type]) {
7551 ssh->packet_dispatch[pktin->type](ssh, pktin);
7555 if (!ssh->protocol_initial_phase_done ||
7556 (pktin && pktin->type >= 20 && pktin->type < 50)) {
7557 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
7558 !ssh->protocol_initial_phase_done) {
7559 ssh->protocol_initial_phase_done = TRUE;
7561 * Allow authconn to initialise itself.
7563 do_ssh2_authconn(ssh, NULL, 0, NULL);
7566 do_ssh2_authconn(ssh, in, inlen, pktin);
7571 * Called to set up the connection.
7573 * Returns an error message, or NULL on success.
7575 static const char *ssh_init(void *frontend_handle, void **backend_handle,
7577 char *host, int port, char **realhost, int nodelay,
7583 ssh = snew(struct ssh_tag);
7584 ssh->cfg = *cfg; /* STRUCTURE COPY */
7585 ssh->version = 0; /* when not ready yet */
7588 ssh->v1_cipher_ctx = NULL;
7589 ssh->crcda_ctx = NULL;
7590 ssh->cscipher = NULL;
7591 ssh->cs_cipher_ctx = NULL;
7592 ssh->sccipher = NULL;
7593 ssh->sc_cipher_ctx = NULL;
7595 ssh->cs_mac_ctx = NULL;
7597 ssh->sc_mac_ctx = NULL;
7599 ssh->cs_comp_ctx = NULL;
7601 ssh->sc_comp_ctx = NULL;
7603 ssh->kex_ctx = NULL;
7604 ssh->hostkey = NULL;
7606 ssh->close_expected = FALSE;
7607 ssh->state = SSH_STATE_PREPACKET;
7608 ssh->size_needed = FALSE;
7609 ssh->eof_needed = FALSE;
7612 ssh->deferred_send_data = NULL;
7613 ssh->deferred_len = 0;
7614 ssh->deferred_size = 0;
7615 ssh->fallback_cmd = 0;
7617 ssh->x11auth = NULL;
7618 ssh->v1_compressing = FALSE;
7619 ssh->v2_outgoing_sequence = 0;
7620 ssh->ssh1_rdpkt_crstate = 0;
7621 ssh->ssh2_rdpkt_crstate = 0;
7622 ssh->do_ssh_init_crstate = 0;
7623 ssh->ssh_gotdata_crstate = 0;
7624 ssh->do_ssh1_connection_crstate = 0;
7625 ssh->do_ssh1_login_crstate = 0;
7626 ssh->do_ssh2_transport_crstate = 0;
7627 ssh->do_ssh2_authconn_crstate = 0;
7628 ssh->do_ssh_init_state = NULL;
7629 ssh->do_ssh1_login_state = NULL;
7630 ssh->do_ssh2_transport_state = NULL;
7631 ssh->do_ssh2_authconn_state = NULL;
7632 ssh->mainchan = NULL;
7633 ssh->throttled_all = 0;
7634 ssh->v1_stdout_throttling = 0;
7636 ssh->queuelen = ssh->queuesize = 0;
7637 ssh->queueing = FALSE;
7638 ssh->qhead = ssh->qtail = NULL;
7639 ssh->deferred_rekey_reason = NULL;
7640 bufchain_init(&ssh->queued_incoming_data);
7641 ssh->frozen = FALSE;
7643 *backend_handle = ssh;
7646 if (crypto_startup() == 0)
7647 return "Microsoft high encryption pack not installed!";
7650 ssh->frontend = frontend_handle;
7651 ssh->term_width = ssh->cfg.width;
7652 ssh->term_height = ssh->cfg.height;
7654 ssh->channels = NULL;
7655 ssh->rportfwds = NULL;
7656 ssh->portfwds = NULL;
7661 ssh->v1_throttle_count = 0;
7662 ssh->overall_bufsize = 0;
7663 ssh->fallback_cmd = 0;
7665 ssh->protocol = NULL;
7667 ssh->protocol_initial_phase_done = FALSE;
7671 ssh->incoming_data_size = ssh->outgoing_data_size =
7672 ssh->deferred_data_size = 0L;
7673 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
7674 ssh->kex_in_progress = FALSE;
7676 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
7685 static void ssh_free(void *handle)
7687 Ssh ssh = (Ssh) handle;
7688 struct ssh_channel *c;
7689 struct ssh_rportfwd *pf;
7691 if (ssh->v1_cipher_ctx)
7692 ssh->cipher->free_context(ssh->v1_cipher_ctx);
7693 if (ssh->cs_cipher_ctx)
7694 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7695 if (ssh->sc_cipher_ctx)
7696 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7697 if (ssh->cs_mac_ctx)
7698 ssh->csmac->free_context(ssh->cs_mac_ctx);
7699 if (ssh->sc_mac_ctx)
7700 ssh->scmac->free_context(ssh->sc_mac_ctx);
7701 if (ssh->cs_comp_ctx) {
7703 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7705 zlib_compress_cleanup(ssh->cs_comp_ctx);
7707 if (ssh->sc_comp_ctx) {
7709 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7711 zlib_decompress_cleanup(ssh->sc_comp_ctx);
7714 dh_cleanup(ssh->kex_ctx);
7715 sfree(ssh->savedhost);
7717 while (ssh->queuelen-- > 0)
7718 ssh_free_packet(ssh->queue[ssh->queuelen]);
7721 while (ssh->qhead) {
7722 struct queued_handler *qh = ssh->qhead;
7723 ssh->qhead = qh->next;
7726 ssh->qhead = ssh->qtail = NULL;
7728 if (ssh->channels) {
7729 while ((c = delpos234(ssh->channels, 0)) != NULL) {
7732 if (c->u.x11.s != NULL)
7733 x11_close(c->u.x11.s);
7736 if (c->u.pfd.s != NULL)
7737 pfd_close(c->u.pfd.s);
7742 freetree234(ssh->channels);
7743 ssh->channels = NULL;
7746 if (ssh->rportfwds) {
7747 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
7749 freetree234(ssh->rportfwds);
7750 ssh->rportfwds = NULL;
7752 sfree(ssh->deferred_send_data);
7754 x11_free_auth(ssh->x11auth);
7755 sfree(ssh->do_ssh_init_state);
7756 sfree(ssh->do_ssh1_login_state);
7757 sfree(ssh->do_ssh2_transport_state);
7758 sfree(ssh->do_ssh2_authconn_state);
7759 if (ssh->crcda_ctx) {
7760 crcda_free_context(ssh->crcda_ctx);
7761 ssh->crcda_ctx = NULL;
7764 ssh_do_close(ssh, TRUE);
7765 expire_timer_context(ssh);
7767 pinger_free(ssh->pinger);
7768 bufchain_clear(&ssh->queued_incoming_data);
7775 * Reconfigure the SSH backend.
7777 static void ssh_reconfig(void *handle, Config *cfg)
7779 Ssh ssh = (Ssh) handle;
7780 char *rekeying = NULL, rekey_mandatory = FALSE;
7781 unsigned long old_max_data_size;
7783 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
7784 ssh_setup_portfwd(ssh, cfg);
7786 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
7787 cfg->ssh_rekey_time != 0) {
7788 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
7789 long now = GETTICKCOUNT();
7791 if (new_next - now < 0) {
7792 rekeying = "timeout shortened";
7794 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
7798 old_max_data_size = ssh->max_data_size;
7799 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
7800 if (old_max_data_size != ssh->max_data_size &&
7801 ssh->max_data_size != 0) {
7802 if (ssh->outgoing_data_size > ssh->max_data_size ||
7803 ssh->incoming_data_size > ssh->max_data_size)
7804 rekeying = "data limit lowered";
7807 if (ssh->cfg.compression != cfg->compression) {
7808 rekeying = "compression setting changed";
7809 rekey_mandatory = TRUE;
7812 if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
7813 memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
7814 sizeof(ssh->cfg.ssh_cipherlist))) {
7815 rekeying = "cipher settings changed";
7816 rekey_mandatory = TRUE;
7819 ssh->cfg = *cfg; /* STRUCTURE COPY */
7822 if (!ssh->kex_in_progress) {
7823 do_ssh2_transport(ssh, rekeying, -1, NULL);
7824 } else if (rekey_mandatory) {
7825 ssh->deferred_rekey_reason = rekeying;
7831 * Called to send data down the Telnet connection.
7833 static int ssh_send(void *handle, char *buf, int len)
7835 Ssh ssh = (Ssh) handle;
7837 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
7840 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
7842 return ssh_sendbuffer(ssh);
7846 * Called to query the current amount of buffered stdin data.
7848 static int ssh_sendbuffer(void *handle)
7850 Ssh ssh = (Ssh) handle;
7853 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
7857 * If the SSH socket itself has backed up, add the total backup
7858 * size on that to any individual buffer on the stdin channel.
7861 if (ssh->throttled_all)
7862 override_value = ssh->overall_bufsize;
7864 if (ssh->version == 1) {
7865 return override_value;
7866 } else if (ssh->version == 2) {
7867 if (!ssh->mainchan || ssh->mainchan->closes > 0)
7868 return override_value;
7870 return (override_value +
7871 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
7878 * Called to set the size of the window from SSH's POV.
7880 static void ssh_size(void *handle, int width, int height)
7882 Ssh ssh = (Ssh) handle;
7883 struct Packet *pktout;
7885 ssh->term_width = width;
7886 ssh->term_height = height;
7888 switch (ssh->state) {
7889 case SSH_STATE_BEFORE_SIZE:
7890 case SSH_STATE_PREPACKET:
7891 case SSH_STATE_CLOSED:
7892 break; /* do nothing */
7893 case SSH_STATE_INTERMED:
7894 ssh->size_needed = TRUE; /* buffer for later */
7896 case SSH_STATE_SESSION:
7897 if (!ssh->cfg.nopty) {
7898 if (ssh->version == 1) {
7899 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
7900 PKT_INT, ssh->term_height,
7901 PKT_INT, ssh->term_width,
7902 PKT_INT, 0, PKT_INT, 0, PKT_END);
7903 } else if (ssh->mainchan) {
7904 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7905 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7906 ssh2_pkt_addstring(pktout, "window-change");
7907 ssh2_pkt_addbool(pktout, 0);
7908 ssh2_pkt_adduint32(pktout, ssh->term_width);
7909 ssh2_pkt_adduint32(pktout, ssh->term_height);
7910 ssh2_pkt_adduint32(pktout, 0);
7911 ssh2_pkt_adduint32(pktout, 0);
7912 ssh2_pkt_send(ssh, pktout);
7920 * Return a list of the special codes that make sense in this
7923 static const struct telnet_special *ssh_get_specials(void *handle)
7925 static const struct telnet_special ssh1_ignore_special[] = {
7926 {"IGNORE message", TS_NOP}
7928 static const struct telnet_special ssh2_transport_specials[] = {
7929 {"IGNORE message", TS_NOP},
7930 {"Repeat key exchange", TS_REKEY},
7932 static const struct telnet_special ssh2_session_specials[] = {
7935 /* These are the signal names defined by draft-ietf-secsh-connect-23.
7936 * They include all the ISO C signals, but are a subset of the POSIX
7937 * required signals. */
7938 {"SIGINT (Interrupt)", TS_SIGINT},
7939 {"SIGTERM (Terminate)", TS_SIGTERM},
7940 {"SIGKILL (Kill)", TS_SIGKILL},
7941 {"SIGQUIT (Quit)", TS_SIGQUIT},
7942 {"SIGHUP (Hangup)", TS_SIGHUP},
7943 {"More signals", TS_SUBMENU},
7944 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
7945 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
7946 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
7947 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
7950 static const struct telnet_special specials_end[] = {
7953 /* XXX review this length for any changes: */
7954 static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
7955 lenof(ssh2_session_specials) +
7956 lenof(specials_end)];
7957 Ssh ssh = (Ssh) handle;
7959 #define ADD_SPECIALS(name) \
7961 assert((i + lenof(name)) <= lenof(ssh_specials)); \
7962 memcpy(&ssh_specials[i], name, sizeof name); \
7966 if (ssh->version == 1) {
7967 /* Don't bother offering IGNORE if we've decided the remote
7968 * won't cope with it, since we wouldn't bother sending it if
7970 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7971 ADD_SPECIALS(ssh1_ignore_special);
7972 } else if (ssh->version == 2) {
7973 ADD_SPECIALS(ssh2_transport_specials);
7975 ADD_SPECIALS(ssh2_session_specials);
7976 } /* else we're not ready yet */
7979 ADD_SPECIALS(specials_end);
7980 return ssh_specials;
7988 * Send Telnet special codes. TS_EOF is useful for `plink', so you
7989 * can send an EOF and collect resulting output (e.g. `plink
7992 static void ssh_special(void *handle, Telnet_Special code)
7994 Ssh ssh = (Ssh) handle;
7995 struct Packet *pktout;
7997 if (code == TS_EOF) {
7998 if (ssh->state != SSH_STATE_SESSION) {
8000 * Buffer the EOF in case we are pre-SESSION, so we can
8001 * send it as soon as we reach SESSION.
8004 ssh->eof_needed = TRUE;
8007 if (ssh->version == 1) {
8008 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
8009 } else if (ssh->mainchan) {
8010 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
8011 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8012 ssh2_pkt_send(ssh, pktout);
8013 ssh->send_ok = 0; /* now stop trying to read from stdin */
8015 logevent("Sent EOF message");
8016 } else if (code == TS_PING || code == TS_NOP) {
8017 if (ssh->state == SSH_STATE_CLOSED
8018 || ssh->state == SSH_STATE_PREPACKET) return;
8019 if (ssh->version == 1) {
8020 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
8021 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
8023 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
8024 ssh2_pkt_addstring_start(pktout);
8025 ssh2_pkt_send_noqueue(ssh, pktout);
8027 } else if (code == TS_REKEY) {
8028 if (!ssh->kex_in_progress && ssh->version == 2) {
8029 do_ssh2_transport(ssh, "at user request", -1, NULL);
8031 } else if (code == TS_BRK) {
8032 if (ssh->state == SSH_STATE_CLOSED
8033 || ssh->state == SSH_STATE_PREPACKET) return;
8034 if (ssh->version == 1) {
8035 logevent("Unable to send BREAK signal in SSH-1");
8036 } else if (ssh->mainchan) {
8037 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8038 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8039 ssh2_pkt_addstring(pktout, "break");
8040 ssh2_pkt_addbool(pktout, 0);
8041 ssh2_pkt_adduint32(pktout, 0); /* default break length */
8042 ssh2_pkt_send(ssh, pktout);
8045 /* Is is a POSIX signal? */
8046 char *signame = NULL;
8047 if (code == TS_SIGABRT) signame = "ABRT";
8048 if (code == TS_SIGALRM) signame = "ALRM";
8049 if (code == TS_SIGFPE) signame = "FPE";
8050 if (code == TS_SIGHUP) signame = "HUP";
8051 if (code == TS_SIGILL) signame = "ILL";
8052 if (code == TS_SIGINT) signame = "INT";
8053 if (code == TS_SIGKILL) signame = "KILL";
8054 if (code == TS_SIGPIPE) signame = "PIPE";
8055 if (code == TS_SIGQUIT) signame = "QUIT";
8056 if (code == TS_SIGSEGV) signame = "SEGV";
8057 if (code == TS_SIGTERM) signame = "TERM";
8058 if (code == TS_SIGUSR1) signame = "USR1";
8059 if (code == TS_SIGUSR2) signame = "USR2";
8060 /* The SSH-2 protocol does in principle support arbitrary named
8061 * signals, including signame@domain, but we don't support those. */
8063 /* It's a signal. */
8064 if (ssh->version == 2 && ssh->mainchan) {
8065 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8066 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8067 ssh2_pkt_addstring(pktout, "signal");
8068 ssh2_pkt_addbool(pktout, 0);
8069 ssh2_pkt_addstring(pktout, signame);
8070 ssh2_pkt_send(ssh, pktout);
8071 logeventf(ssh, "Sent signal SIG%s", signame);
8074 /* Never heard of it. Do nothing */
8079 void *new_sock_channel(void *handle, Socket s)
8081 Ssh ssh = (Ssh) handle;
8082 struct ssh_channel *c;
8083 c = snew(struct ssh_channel);
8088 c->localid = alloc_channel_id(ssh);
8090 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
8092 bufchain_init(&c->v.v2.outbuffer);
8093 add234(ssh->channels, c);
8099 * This is called when stdout/stderr (the entity to which
8100 * from_backend sends data) manages to clear some backlog.
8102 static void ssh_unthrottle(void *handle, int bufsize)
8104 Ssh ssh = (Ssh) handle;
8105 if (ssh->version == 1) {
8106 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
8107 ssh->v1_stdout_throttling = 0;
8108 ssh1_throttle(ssh, -1);
8111 if (ssh->mainchan && ssh->mainchan->closes == 0)
8112 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
8116 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
8118 struct ssh_channel *c = (struct ssh_channel *)channel;
8120 struct Packet *pktout;
8122 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
8124 if (ssh->version == 1) {
8125 send_packet(ssh, SSH1_MSG_PORT_OPEN,
8126 PKT_INT, c->localid,
8129 /* PKT_STR, <org:orgport>, */
8132 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
8133 ssh2_pkt_addstring(pktout, "direct-tcpip");
8134 ssh2_pkt_adduint32(pktout, c->localid);
8135 c->v.v2.locwindow = OUR_V2_WINSIZE;
8136 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
8137 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8138 ssh2_pkt_addstring(pktout, hostname);
8139 ssh2_pkt_adduint32(pktout, port);
8141 * We make up values for the originator data; partly it's
8142 * too much hassle to keep track, and partly I'm not
8143 * convinced the server should be told details like that
8144 * about my local network configuration.
8146 ssh2_pkt_addstring(pktout, "client-side-connection");
8147 ssh2_pkt_adduint32(pktout, 0);
8148 ssh2_pkt_send(ssh, pktout);
8152 static Socket ssh_socket(void *handle)
8154 Ssh ssh = (Ssh) handle;
8158 static int ssh_sendok(void *handle)
8160 Ssh ssh = (Ssh) handle;
8161 return ssh->send_ok;
8164 static int ssh_ldisc(void *handle, int option)
8166 Ssh ssh = (Ssh) handle;
8167 if (option == LD_ECHO)
8168 return ssh->echoing;
8169 if (option == LD_EDIT)
8170 return ssh->editing;
8174 static void ssh_provide_ldisc(void *handle, void *ldisc)
8176 Ssh ssh = (Ssh) handle;
8180 static void ssh_provide_logctx(void *handle, void *logctx)
8182 Ssh ssh = (Ssh) handle;
8183 ssh->logctx = logctx;
8186 static int ssh_return_exitcode(void *handle)
8188 Ssh ssh = (Ssh) handle;
8192 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
8196 * cfg_info for SSH is the currently running version of the
8197 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
8199 static int ssh_cfg_info(void *handle)
8201 Ssh ssh = (Ssh) handle;
8202 return ssh->version;
8206 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
8207 * that fails. This variable is the means by which scp.c can reach
8208 * into the SSH code and find out which one it got.
8210 extern int ssh_fallback_cmd(void *handle)
8212 Ssh ssh = (Ssh) handle;
8213 return ssh->fallback_cmd;
8216 Backend ssh_backend = {
8226 ssh_return_exitcode,