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_PUBLICKEY 0x0010
110 #define SSH2_PKTCTX_PASSWORD 0x0020
111 #define SSH2_PKTCTX_KBDINTER 0x0040
112 #define SSH2_PKTCTX_AUTH_MASK 0x00F0
114 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
115 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
116 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
117 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
118 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
119 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
120 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
121 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
122 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
123 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
124 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
125 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
126 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
127 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
128 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
130 static const char *const ssh2_disconnect_reasons[] = {
132 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
133 "SSH_DISCONNECT_PROTOCOL_ERROR",
134 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
135 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
136 "SSH_DISCONNECT_MAC_ERROR",
137 "SSH_DISCONNECT_COMPRESSION_ERROR",
138 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
139 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
140 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
141 "SSH_DISCONNECT_CONNECTION_LOST",
142 "SSH_DISCONNECT_BY_APPLICATION",
143 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
144 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
145 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
146 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
149 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
150 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
151 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
152 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
154 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
157 * Various remote-bug flags.
159 #define BUG_CHOKES_ON_SSH1_IGNORE 1
160 #define BUG_SSH2_HMAC 2
161 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
162 #define BUG_CHOKES_ON_RSA 8
163 #define BUG_SSH2_RSA_PADDING 16
164 #define BUG_SSH2_DERIVEKEY 32
165 /* 64 was BUG_SSH2_DH_GEX, now spare */
166 #define BUG_SSH2_PK_SESSIONID 128
168 #define translate(x) if (type == x) return #x
169 #define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
170 static char *ssh1_pkt_type(int type)
172 translate(SSH1_MSG_DISCONNECT);
173 translate(SSH1_SMSG_PUBLIC_KEY);
174 translate(SSH1_CMSG_SESSION_KEY);
175 translate(SSH1_CMSG_USER);
176 translate(SSH1_CMSG_AUTH_RSA);
177 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
178 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
179 translate(SSH1_CMSG_AUTH_PASSWORD);
180 translate(SSH1_CMSG_REQUEST_PTY);
181 translate(SSH1_CMSG_WINDOW_SIZE);
182 translate(SSH1_CMSG_EXEC_SHELL);
183 translate(SSH1_CMSG_EXEC_CMD);
184 translate(SSH1_SMSG_SUCCESS);
185 translate(SSH1_SMSG_FAILURE);
186 translate(SSH1_CMSG_STDIN_DATA);
187 translate(SSH1_SMSG_STDOUT_DATA);
188 translate(SSH1_SMSG_STDERR_DATA);
189 translate(SSH1_CMSG_EOF);
190 translate(SSH1_SMSG_EXIT_STATUS);
191 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
192 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
193 translate(SSH1_MSG_CHANNEL_DATA);
194 translate(SSH1_MSG_CHANNEL_CLOSE);
195 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
196 translate(SSH1_SMSG_X11_OPEN);
197 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
198 translate(SSH1_MSG_PORT_OPEN);
199 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
200 translate(SSH1_SMSG_AGENT_OPEN);
201 translate(SSH1_MSG_IGNORE);
202 translate(SSH1_CMSG_EXIT_CONFIRMATION);
203 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
204 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
205 translate(SSH1_MSG_DEBUG);
206 translate(SSH1_CMSG_REQUEST_COMPRESSION);
207 translate(SSH1_CMSG_AUTH_TIS);
208 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
209 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
210 translate(SSH1_CMSG_AUTH_CCARD);
211 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
212 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
215 static char *ssh2_pkt_type(int pkt_ctx, int type)
217 translate(SSH2_MSG_DISCONNECT);
218 translate(SSH2_MSG_IGNORE);
219 translate(SSH2_MSG_UNIMPLEMENTED);
220 translate(SSH2_MSG_DEBUG);
221 translate(SSH2_MSG_SERVICE_REQUEST);
222 translate(SSH2_MSG_SERVICE_ACCEPT);
223 translate(SSH2_MSG_KEXINIT);
224 translate(SSH2_MSG_NEWKEYS);
225 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
226 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
227 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
228 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
229 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
230 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
231 translate(SSH2_MSG_USERAUTH_REQUEST);
232 translate(SSH2_MSG_USERAUTH_FAILURE);
233 translate(SSH2_MSG_USERAUTH_SUCCESS);
234 translate(SSH2_MSG_USERAUTH_BANNER);
235 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
236 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
237 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
238 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
239 translate(SSH2_MSG_GLOBAL_REQUEST);
240 translate(SSH2_MSG_REQUEST_SUCCESS);
241 translate(SSH2_MSG_REQUEST_FAILURE);
242 translate(SSH2_MSG_CHANNEL_OPEN);
243 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
244 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
245 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
246 translate(SSH2_MSG_CHANNEL_DATA);
247 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
248 translate(SSH2_MSG_CHANNEL_EOF);
249 translate(SSH2_MSG_CHANNEL_CLOSE);
250 translate(SSH2_MSG_CHANNEL_REQUEST);
251 translate(SSH2_MSG_CHANNEL_SUCCESS);
252 translate(SSH2_MSG_CHANNEL_FAILURE);
258 #define GET_32BIT(cp) \
259 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
260 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
261 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
262 ((unsigned long)(unsigned char)(cp)[3]))
264 #define PUT_32BIT(cp, value) { \
265 (cp)[0] = (unsigned char)((value) >> 24); \
266 (cp)[1] = (unsigned char)((value) >> 16); \
267 (cp)[2] = (unsigned char)((value) >> 8); \
268 (cp)[3] = (unsigned char)(value); }
270 /* Enumeration values for fields in SSH-1 packets */
272 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
273 /* These values are for communicating relevant semantics of
274 * fields to the packet logging code. */
275 PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA
279 * Coroutine mechanics for the sillier bits of the code. If these
280 * macros look impenetrable to you, you might find it helpful to
283 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
285 * which explains the theory behind these macros.
287 * In particular, if you are getting `case expression not constant'
288 * errors when building with MS Visual Studio, this is because MS's
289 * Edit and Continue debugging feature causes their compiler to
290 * violate ANSI C. To disable Edit and Continue debugging:
292 * - right-click ssh.c in the FileView
294 * - select the C/C++ tab and the General category
295 * - under `Debug info:', select anything _other_ than `Program
296 * Database for Edit and Continue'.
298 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
301 if (!ssh->t) ssh->t = snew(struct t); \
303 #define crFinish(z) } *crLine = 0; return (z); }
304 #define crFinishV } *crLine = 0; return; }
305 #define crReturn(z) \
307 *crLine =__LINE__; return (z); case __LINE__:;\
311 *crLine=__LINE__; return; case __LINE__:;\
313 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
314 #define crStopV do{ *crLine = 0; return; }while(0)
315 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
316 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
318 typedef struct ssh_tag *Ssh;
321 static struct Packet *ssh2_pkt_init(int pkt_type);
322 static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
323 static void ssh2_pkt_adduint32(struct Packet *, unsigned long value);
324 static void ssh2_pkt_addstring_start(struct Packet *);
325 static void ssh2_pkt_addstring_str(struct Packet *, char *data);
326 static void ssh2_pkt_addstring_data(struct Packet *, char *data, int len);
327 static void ssh2_pkt_addstring(struct Packet *, char *data);
328 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
329 static void ssh2_pkt_addmp(struct Packet *, Bignum b);
330 static int ssh2_pkt_construct(Ssh, struct Packet *);
331 static void ssh2_pkt_send(Ssh, struct Packet *);
332 static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
333 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
334 struct Packet *pktin);
335 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
336 struct Packet *pktin);
339 * Buffer management constants. There are several of these for
340 * various different purposes:
342 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
343 * on a local data stream before we throttle the whole SSH
344 * connection (in SSH1 only). Throttling the whole connection is
345 * pretty drastic so we set this high in the hope it won't
348 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
349 * on the SSH connection itself before we defensively throttle
350 * _all_ local data streams. This is pretty drastic too (though
351 * thankfully unlikely in SSH2 since the window mechanism should
352 * ensure that the server never has any need to throttle its end
353 * of the connection), so we set this high as well.
355 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
359 #define SSH1_BUFFER_LIMIT 32768
360 #define SSH_MAX_BACKLOG 32768
361 #define OUR_V2_WINSIZE 16384
363 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
365 static void *nullmac_make_context(void)
369 static void nullmac_free_context(void *handle)
372 static void nullmac_key(void *handle, unsigned char *key)
375 static void nullmac_generate(void *handle, unsigned char *blk, int len,
379 static int nullmac_verify(void *handle, unsigned char *blk, int len,
384 const static struct ssh_mac ssh_mac_none = {
385 nullmac_make_context, nullmac_free_context, nullmac_key,
386 nullmac_generate, nullmac_verify, "none", 0
388 const static struct ssh_mac *macs[] = {
389 &ssh_sha1, &ssh_md5, &ssh_mac_none
391 const static struct ssh_mac *buggymacs[] = {
392 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
395 static void *ssh_comp_none_init(void)
399 static void ssh_comp_none_cleanup(void *handle)
402 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
403 unsigned char **outblock, int *outlen)
407 static int ssh_comp_none_disable(void *handle)
411 const static struct ssh_compress ssh_comp_none = {
413 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
414 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
415 ssh_comp_none_disable, NULL
417 extern const struct ssh_compress ssh_zlib;
418 const static struct ssh_compress *compressions[] = {
419 &ssh_zlib, &ssh_comp_none
422 enum { /* channel types */
427 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
431 * 2-3-4 tree storing channels.
434 Ssh ssh; /* pointer back to main context */
435 unsigned remoteid, localid;
438 * In SSH1, this value contains four bits:
440 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
441 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
442 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
443 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
445 * A channel is completely finished with when all four bits are set.
449 struct ssh1_data_channel {
452 struct ssh2_data_channel {
454 unsigned remwindow, remmaxpkt;
459 struct ssh_agent_channel {
460 unsigned char *message;
461 unsigned char msglen[4];
462 unsigned lensofar, totallen;
464 struct ssh_x11_channel {
467 struct ssh_pfd_channel {
474 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
475 * 2 use this structure in different ways, reflecting SSH 2's
476 * altogether saner approach to port forwarding.
478 * In SSH 1, you arrange a remote forwarding by sending the server
479 * the remote port number, and the local destination host:port.
480 * When a connection comes in, the server sends you back that
481 * host:port pair, and you connect to it. This is a ready-made
482 * security hole if you're not on the ball: a malicious server
483 * could send you back _any_ host:port pair, so if you trustingly
484 * connect to the address it gives you then you've just opened the
485 * entire inside of your corporate network just by connecting
486 * through it to a dodgy SSH server. Hence, we must store a list of
487 * host:port pairs we _are_ trying to forward to, and reject a
488 * connection request from the server if it's not in the list.
490 * In SSH 2, each side of the connection minds its own business and
491 * doesn't send unnecessary information to the other. You arrange a
492 * remote forwarding by sending the server just the remote port
493 * number. When a connection comes in, the server tells you which
494 * of its ports was connected to; and _you_ have to remember what
495 * local host:port pair went with that port number.
497 * Hence, in SSH 1 this structure is indexed by destination
498 * host:port pair, whereas in SSH 2 it is indexed by source port.
500 struct ssh_portfwd; /* forward declaration */
502 struct ssh_rportfwd {
503 unsigned sport, dport;
506 struct ssh_portfwd *pfrec;
508 #define free_rportfwd(pf) ( \
509 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
512 * Separately to the rportfwd tree (which is for looking up port
513 * open requests from the server), a tree of _these_ structures is
514 * used to keep track of all the currently open port forwardings,
515 * so that we can reconfigure in mid-session if the user requests
519 enum { DESTROY, KEEP, CREATE } status;
521 unsigned sport, dport;
524 struct ssh_rportfwd *remote;
528 #define free_portfwd(pf) ( \
529 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
530 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
535 unsigned long sequence;
540 long encrypted_len; /* for SSH2 total-size counting */
543 * State associated with packet logging
547 struct logblank_t *blanks;
550 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
551 struct Packet *pktin);
552 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
553 struct Packet *pktin);
554 static void ssh1_protocol_setup(Ssh ssh);
555 static void ssh2_protocol_setup(Ssh ssh);
556 static void ssh_size(void *handle, int width, int height);
557 static void ssh_special(void *handle, Telnet_Special);
558 static int ssh2_try_send(struct ssh_channel *c);
559 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
560 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
561 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
562 static int ssh_sendbuffer(void *handle);
563 static void ssh_do_close(Ssh ssh);
564 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
565 static int ssh2_pkt_getbool(struct Packet *pkt);
566 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
567 static void ssh2_timer(void *ctx, long now);
568 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
569 struct Packet *pktin);
571 struct rdpkt1_state_tag {
572 long len, pad, biglen, to_read;
573 unsigned long realcrc, gotcrc;
577 struct Packet *pktin;
580 struct rdpkt2_state_tag {
581 long len, pad, payload, packetlen, maclen;
584 unsigned long incoming_sequence;
585 struct Packet *pktin;
588 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
589 typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
591 struct queued_handler;
592 struct queued_handler {
594 chandler_fn_t handler;
596 struct queued_handler *next;
600 const struct plug_function_table *fn;
601 /* the above field _must_ be first in the structure */
603 SHA_State exhash, exhashbase;
610 unsigned char session_key[32];
612 int v1_remote_protoflags;
613 int v1_local_protoflags;
614 int agentfwd_enabled;
617 const struct ssh_cipher *cipher;
620 const struct ssh2_cipher *cscipher, *sccipher;
621 void *cs_cipher_ctx, *sc_cipher_ctx;
622 const struct ssh_mac *csmac, *scmac;
623 void *cs_mac_ctx, *sc_mac_ctx;
624 const struct ssh_compress *cscomp, *sccomp;
625 void *cs_comp_ctx, *sc_comp_ctx;
626 const struct ssh_kex *kex;
627 const struct ssh_signkey *hostkey;
628 unsigned char v2_session_id[20];
634 int echoing, editing;
638 int ospeed, ispeed; /* temporaries */
639 int term_width, term_height;
641 tree234 *channels; /* indexed by local id */
642 struct ssh_channel *mainchan; /* primary session channel */
645 tree234 *rportfwds, *portfwds;
649 SSH_STATE_BEFORE_SIZE,
655 int size_needed, eof_needed;
657 struct Packet **queue;
658 int queuelen, queuesize;
660 unsigned char *deferred_send_data;
661 int deferred_len, deferred_size;
664 * Gross hack: pscp will try to start SFTP but fall back to
665 * scp1 if that fails. This variable is the means by which
666 * scp.c can reach into the SSH code and find out which one it
672 * Used for username and password input.
674 char *userpass_input_buffer;
675 int userpass_input_buflen;
676 int userpass_input_bufpos;
677 int userpass_input_echo;
684 int v1_throttle_count;
687 int v1_stdout_throttling;
688 int v2_outgoing_sequence;
690 int ssh1_rdpkt_crstate;
691 int ssh2_rdpkt_crstate;
692 int do_ssh_init_crstate;
693 int ssh_gotdata_crstate;
694 int do_ssh1_login_crstate;
695 int do_ssh1_connection_crstate;
696 int do_ssh2_transport_crstate;
697 int do_ssh2_authconn_crstate;
699 void *do_ssh_init_state;
700 void *do_ssh1_login_state;
701 void *do_ssh2_transport_state;
702 void *do_ssh2_authconn_state;
704 struct rdpkt1_state_tag rdpkt1_state;
705 struct rdpkt2_state_tag rdpkt2_state;
707 /* ssh1 and ssh2 use this for different things, but both use it */
708 int protocol_initial_phase_done;
710 void (*protocol) (Ssh ssh, unsigned char *in, int inlen,
712 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
715 * We maintain a full _copy_ of a Config structure here, not
716 * merely a pointer to it. That way, when we're passed a new
717 * one for reconfiguration, we can check the differences and
718 * potentially reconfigure port forwardings etc in mid-session.
723 * Used to transfer data back from async agent callbacks.
725 void *agent_response;
726 int agent_response_len;
729 * Dispatch table for packet types that we may have to deal
732 handler_fn_t packet_dispatch[256];
735 * Queues of one-off handler functions for success/failure
736 * indications from a request.
738 struct queued_handler *qhead, *qtail;
741 * This module deals with sending keepalives.
746 * Track incoming and outgoing data sizes and time, for
749 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
750 unsigned long max_data_size;
752 long next_rekey, last_rekey;
755 #define logevent(s) logevent(ssh->frontend, s)
757 /* logevent, only printf-formatted. */
758 static void logeventf(Ssh ssh, const char *fmt, ...)
764 buf = dupvprintf(fmt, ap);
770 #define bombout(msg) \
772 char *text = dupprintf msg; \
775 connection_fatal(ssh->frontend, "%s", text); \
779 /* Functions to leave bits out of the SSH packet log file. */
781 static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
783 if (ssh->cfg.logomitpass)
784 pkt->logmode = blanktype;
787 static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
789 if (ssh->cfg.logomitdata)
790 pkt->logmode = blanktype;
793 static void end_log_omission(Ssh ssh, struct Packet *pkt)
795 pkt->logmode = PKTLOG_EMIT;
798 static int ssh_channelcmp(void *av, void *bv)
800 struct ssh_channel *a = (struct ssh_channel *) av;
801 struct ssh_channel *b = (struct ssh_channel *) bv;
802 if (a->localid < b->localid)
804 if (a->localid > b->localid)
808 static int ssh_channelfind(void *av, void *bv)
810 unsigned *a = (unsigned *) av;
811 struct ssh_channel *b = (struct ssh_channel *) bv;
819 static int ssh_rportcmp_ssh1(void *av, void *bv)
821 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
822 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
824 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
825 return i < 0 ? -1 : +1;
826 if (a->dport > b->dport)
828 if (a->dport < b->dport)
833 static int ssh_rportcmp_ssh2(void *av, void *bv)
835 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
836 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
838 if (a->sport > b->sport)
840 if (a->sport < b->sport)
846 * Special form of strcmp which can cope with NULL inputs. NULL is
847 * defined to sort before even the empty string.
849 static int nullstrcmp(const char *a, const char *b)
851 if (a == NULL && b == NULL)
860 static int ssh_portcmp(void *av, void *bv)
862 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
863 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
865 if (a->type > b->type)
867 if (a->type < b->type)
869 if (a->addressfamily > b->addressfamily)
871 if (a->addressfamily < b->addressfamily)
873 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
874 return i < 0 ? -1 : +1;
875 if (a->sport > b->sport)
877 if (a->sport < b->sport)
879 if (a->type != 'D') {
880 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
881 return i < 0 ? -1 : +1;
882 if (a->dport > b->dport)
884 if (a->dport < b->dport)
890 static int alloc_channel_id(Ssh ssh)
892 const unsigned CHANNEL_NUMBER_OFFSET = 256;
893 unsigned low, high, mid;
895 struct ssh_channel *c;
898 * First-fit allocation of channel numbers: always pick the
899 * lowest unused one. To do this, binary-search using the
900 * counted B-tree to find the largest channel ID which is in a
901 * contiguous sequence from the beginning. (Precisely
902 * everything in that sequence must have ID equal to its tree
903 * index plus CHANNEL_NUMBER_OFFSET.)
905 tsize = count234(ssh->channels);
909 while (high - low > 1) {
910 mid = (high + low) / 2;
911 c = index234(ssh->channels, mid);
912 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
913 low = mid; /* this one is fine */
915 high = mid; /* this one is past it */
918 * Now low points to either -1, or the tree index of the
919 * largest ID in the initial sequence.
922 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
923 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
925 return low + 1 + CHANNEL_NUMBER_OFFSET;
928 static void c_write(Ssh ssh, const char *buf, int len)
930 if ((flags & FLAG_STDERR)) {
932 for (i = 0; i < len; i++)
934 fputc(buf[i], stderr);
937 from_backend(ssh->frontend, 1, buf, len);
940 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
943 for (i = 0; i < len; i++) {
945 c_write(ssh, "\r\n", 2);
946 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
947 c_write(ssh, buf + i, 1);
951 static void c_write_str(Ssh ssh, const char *buf)
953 c_write(ssh, buf, strlen(buf));
956 static void ssh_free_packet(struct Packet *pkt)
961 static struct Packet *ssh_new_packet(void)
963 struct Packet *pkt = snew(struct Packet);
967 pkt->logmode = PKTLOG_EMIT;
975 * Collect incoming data in the incoming packet buffer.
976 * Decipher and verify the packet when it is completely read.
977 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
978 * Update the *data and *datalen variables.
979 * Return a Packet structure when a packet is completed.
981 static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
983 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
985 crBegin(ssh->ssh1_rdpkt_crstate);
987 st->pktin = ssh_new_packet();
990 st->pktin->length = 0;
992 for (st->i = st->len = 0; st->i < 4; st->i++) {
993 while ((*datalen) == 0)
995 st->len = (st->len << 8) + **data;
996 (*data)++, (*datalen)--;
999 st->pad = 8 - (st->len % 8);
1000 st->biglen = st->len + st->pad;
1001 st->pktin->length = st->len - 5;
1003 if (st->biglen < 0) {
1004 bombout(("Extremely large packet length from server suggests"
1005 " data stream corruption"));
1006 ssh_free_packet(st->pktin);
1010 st->pktin->maxlen = st->biglen;
1011 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1013 st->to_read = st->biglen;
1014 st->p = st->pktin->data;
1015 while (st->to_read > 0) {
1016 st->chunk = st->to_read;
1017 while ((*datalen) == 0)
1019 if (st->chunk > (*datalen))
1020 st->chunk = (*datalen);
1021 memcpy(st->p, *data, st->chunk);
1023 *datalen -= st->chunk;
1025 st->to_read -= st->chunk;
1028 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1029 st->biglen, NULL)) {
1030 bombout(("Network attack (CRC compensation) detected!"));
1031 ssh_free_packet(st->pktin);
1036 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1038 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1039 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1040 if (st->gotcrc != st->realcrc) {
1041 bombout(("Incorrect CRC received on packet"));
1042 ssh_free_packet(st->pktin);
1046 st->pktin->body = st->pktin->data + st->pad + 1;
1047 st->pktin->savedpos = 0;
1049 if (ssh->v1_compressing) {
1050 unsigned char *decompblk;
1052 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1053 st->pktin->body - 1, st->pktin->length + 1,
1054 &decompblk, &decomplen)) {
1055 bombout(("Zlib decompression encountered invalid data"));
1056 ssh_free_packet(st->pktin);
1060 if (st->pktin->maxlen < st->pad + decomplen) {
1061 st->pktin->maxlen = st->pad + decomplen;
1062 st->pktin->data = sresize(st->pktin->data,
1063 st->pktin->maxlen + APIEXTRA,
1065 st->pktin->body = st->pktin->data + st->pad + 1;
1068 memcpy(st->pktin->body - 1, decompblk, decomplen);
1070 st->pktin->length = decomplen - 1;
1073 st->pktin->type = st->pktin->body[-1];
1076 * Log incoming packet, possibly omitting sensitive fields.
1080 struct logblank_t blank;
1081 if (ssh->cfg.logomitdata) {
1082 int do_blank = FALSE, blank_prefix = 0;
1083 /* "Session data" packets - omit the data field */
1084 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1085 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
1086 do_blank = TRUE; blank_prefix = 0;
1087 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
1088 do_blank = TRUE; blank_prefix = 4;
1091 blank.offset = blank_prefix;
1092 blank.len = st->pktin->length;
1093 blank.type = PKTLOG_OMIT;
1097 log_packet(ssh->logctx,
1098 PKT_INCOMING, st->pktin->type,
1099 ssh1_pkt_type(st->pktin->type),
1100 st->pktin->body, st->pktin->length,
1104 crFinish(st->pktin);
1107 static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1109 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1111 crBegin(ssh->ssh2_rdpkt_crstate);
1113 st->pktin = ssh_new_packet();
1115 st->pktin->type = 0;
1116 st->pktin->length = 0;
1118 st->cipherblk = ssh->sccipher->blksize;
1121 if (st->cipherblk < 8)
1124 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1127 * Acquire and decrypt the first block of the packet. This will
1128 * contain the length and padding details.
1130 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1131 while ((*datalen) == 0)
1133 st->pktin->data[st->i] = *(*data)++;
1138 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1139 st->pktin->data, st->cipherblk);
1142 * Now get the length and padding figures.
1144 st->len = GET_32BIT(st->pktin->data);
1145 st->pad = st->pktin->data[4];
1148 * _Completely_ silly lengths should be stomped on before they
1149 * do us any more damage.
1151 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
1152 bombout(("Incoming packet was garbled on decryption"));
1153 ssh_free_packet(st->pktin);
1158 * This enables us to deduce the payload length.
1160 st->payload = st->len - st->pad - 1;
1162 st->pktin->length = st->payload + 5;
1165 * So now we can work out the total packet length.
1167 st->packetlen = st->len + 4;
1168 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1171 * Allocate memory for the rest of the packet.
1173 st->pktin->maxlen = st->packetlen + st->maclen;
1174 st->pktin->data = sresize(st->pktin->data,
1175 st->pktin->maxlen + APIEXTRA,
1179 * Read and decrypt the remainder of the packet.
1181 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1183 while ((*datalen) == 0)
1185 st->pktin->data[st->i] = *(*data)++;
1188 /* Decrypt everything _except_ the MAC. */
1190 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1191 st->pktin->data + st->cipherblk,
1192 st->packetlen - st->cipherblk);
1194 st->pktin->encrypted_len = st->packetlen;
1200 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, st->len + 4,
1201 st->incoming_sequence)) {
1202 bombout(("Incorrect MAC received on packet"));
1203 ssh_free_packet(st->pktin);
1207 st->pktin->sequence = st->incoming_sequence++;
1210 * Decompress packet payload.
1213 unsigned char *newpayload;
1216 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1217 st->pktin->data + 5, st->pktin->length - 5,
1218 &newpayload, &newlen)) {
1219 if (st->pktin->maxlen < newlen + 5) {
1220 st->pktin->maxlen = newlen + 5;
1221 st->pktin->data = sresize(st->pktin->data,
1222 st->pktin->maxlen + APIEXTRA,
1225 st->pktin->length = 5 + newlen;
1226 memcpy(st->pktin->data + 5, newpayload, newlen);
1231 st->pktin->savedpos = 6;
1232 st->pktin->body = st->pktin->data;
1233 st->pktin->type = st->pktin->data[5];
1236 * Log incoming packet, possibly omitting sensitive fields.
1240 struct logblank_t blank;
1241 if (ssh->cfg.logomitdata) {
1242 int do_blank = FALSE, blank_prefix = 0;
1243 /* "Session data" packets - omit the data field */
1244 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
1245 do_blank = TRUE; blank_prefix = 4;
1246 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1247 do_blank = TRUE; blank_prefix = 8;
1250 blank.offset = blank_prefix;
1251 blank.len = (st->pktin->length-6) - blank_prefix;
1252 blank.type = PKTLOG_OMIT;
1256 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1257 ssh2_pkt_type(ssh->pkt_ctx, st->pktin->type),
1258 st->pktin->data+6, st->pktin->length-6,
1262 crFinish(st->pktin);
1265 static void ssh1_pktout_size(struct Packet *pkt, int len)
1269 len += 5; /* type and CRC */
1270 pad = 8 - (len % 8);
1273 pkt->length = len - 5;
1274 if (pkt->maxlen < biglen) {
1275 pkt->maxlen = biglen;
1276 pkt->data = sresize(pkt->data, biglen + 4 + APIEXTRA, unsigned char);
1278 pkt->body = pkt->data + 4 + pad + 1;
1281 static struct Packet *s_wrpkt_start(int type, int len)
1283 struct Packet *pkt = ssh_new_packet();
1284 ssh1_pktout_size(pkt, len);
1286 /* Initialise log omission state */
1292 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt)
1298 * XXX various versions of SC (including 8.8.4) screw up the
1299 * register allocation in this function and use the same register
1300 * (D6) for len and as a temporary, with predictable results. The
1301 * following sledgehammer prevents this.
1307 pkt->body[-1] = pkt->type;
1310 log_packet(ssh->logctx, PKT_OUTGOING, pkt->type,
1311 ssh1_pkt_type(pkt->type),
1312 pkt->body, pkt->length,
1313 pkt->nblanks, pkt->blanks);
1314 sfree(pkt->blanks); pkt->blanks = NULL;
1317 if (ssh->v1_compressing) {
1318 unsigned char *compblk;
1320 zlib_compress_block(ssh->cs_comp_ctx,
1321 pkt->body - 1, pkt->length + 1,
1322 &compblk, &complen);
1323 ssh1_pktout_size(pkt, complen - 1);
1324 memcpy(pkt->body - 1, compblk, complen);
1328 len = pkt->length + 5; /* type and CRC */
1329 pad = 8 - (len % 8);
1332 for (i = 0; i < pad; i++)
1333 pkt->data[i + 4] = random_byte();
1334 crc = crc32_compute(pkt->data + 4, biglen - 4);
1335 PUT_32BIT(pkt->data + biglen, crc);
1336 PUT_32BIT(pkt->data, len);
1339 ssh->cipher->encrypt(ssh->v1_cipher_ctx, pkt->data + 4, biglen);
1344 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1347 len = s_wrpkt_prepare(ssh, pkt);
1348 backlog = sk_write(ssh->s, (char *)pkt->data, len);
1349 if (backlog > SSH_MAX_BACKLOG)
1350 ssh_throttle_all(ssh, 1, backlog);
1353 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1356 len = s_wrpkt_prepare(ssh, pkt);
1357 if (ssh->deferred_len + len > ssh->deferred_size) {
1358 ssh->deferred_size = ssh->deferred_len + len + 128;
1359 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1363 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
1364 ssh->deferred_len += len;
1368 * Construct a packet with the specified contents.
1370 static struct Packet *construct_packet(Ssh ssh, int pkttype,
1371 va_list ap1, va_list ap2)
1373 unsigned char *p, *argp, argchar;
1374 unsigned long argint;
1375 int pktlen, argtype, arglen;
1380 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1383 (void) va_arg(ap1, int);
1387 (void) va_arg(ap1, int);
1391 (void) va_arg(ap1, unsigned char *);
1392 arglen = va_arg(ap1, int);
1396 argp = va_arg(ap1, unsigned char *);
1397 arglen = strlen((char *)argp);
1398 pktlen += 4 + arglen;
1401 bn = va_arg(ap1, Bignum);
1402 pktlen += ssh1_bignum_length(bn);
1407 /* ignore this pass */
1414 pkt = s_wrpkt_start(pkttype, pktlen);
1417 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1418 int offset = p - pkt->body, len = 0;
1420 /* Actual fields in the packet */
1422 argint = va_arg(ap2, int);
1423 PUT_32BIT(p, argint);
1427 argchar = (unsigned char) va_arg(ap2, int);
1432 argp = va_arg(ap2, unsigned char *);
1433 arglen = va_arg(ap2, int);
1434 memcpy(p, argp, arglen);
1438 argp = va_arg(ap2, unsigned char *);
1439 arglen = strlen((char *)argp);
1440 PUT_32BIT(p, arglen);
1441 memcpy(p + 4, argp, arglen);
1445 bn = va_arg(ap2, Bignum);
1446 len = ssh1_write_bignum(p, bn);
1448 /* Tokens for modifications to packet logging */
1450 dont_log_password(ssh, pkt, PKTLOG_BLANK);
1453 dont_log_data(ssh, pkt, PKTLOG_OMIT);
1456 end_log_omission(ssh, pkt);
1460 /* Deal with logfile omission, if required. */
1461 if (len && (pkt->logmode != PKTLOG_EMIT)) {
1463 pkt->blanks = sresize(pkt->blanks, pkt->nblanks,
1465 pkt->blanks[pkt->nblanks-1].offset = offset;
1466 pkt->blanks[pkt->nblanks-1].len = len;
1467 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1474 static void send_packet(Ssh ssh, int pkttype, ...)
1478 va_start(ap1, pkttype);
1479 va_start(ap2, pkttype);
1480 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1484 ssh_free_packet(pkt);
1487 static void defer_packet(Ssh ssh, int pkttype, ...)
1491 va_start(ap1, pkttype);
1492 va_start(ap2, pkttype);
1493 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1496 s_wrpkt_defer(ssh, pkt);
1497 ssh_free_packet(pkt);
1500 static int ssh_versioncmp(char *a, char *b)
1503 unsigned long av, bv;
1505 av = strtoul(a, &ae, 10);
1506 bv = strtoul(b, &be, 10);
1508 return (av < bv ? -1 : +1);
1513 av = strtoul(ae, &ae, 10);
1514 bv = strtoul(be, &be, 10);
1516 return (av < bv ? -1 : +1);
1521 * Utility routines for putting an SSH-protocol `string' and
1522 * `uint32' into a SHA state.
1525 static void sha_string(SHA_State * s, void *str, int len)
1527 unsigned char lenblk[4];
1528 PUT_32BIT(lenblk, len);
1529 SHA_Bytes(s, lenblk, 4);
1530 SHA_Bytes(s, str, len);
1533 static void sha_uint32(SHA_State * s, unsigned i)
1535 unsigned char intblk[4];
1536 PUT_32BIT(intblk, i);
1537 SHA_Bytes(s, intblk, 4);
1541 * SSH2 packet construction functions.
1543 static void ssh2_pkt_ensure(struct Packet *pkt, int length)
1545 if (pkt->maxlen < length) {
1546 pkt->maxlen = length + 256;
1547 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
1550 static void ssh2_pkt_adddata(struct Packet *pkt, void *data, int len)
1552 if (pkt->logmode != PKTLOG_EMIT) {
1554 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1555 pkt->blanks[pkt->nblanks-1].offset = pkt->length - 6;
1556 pkt->blanks[pkt->nblanks-1].len = len;
1557 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1560 ssh2_pkt_ensure(pkt, pkt->length);
1561 memcpy(pkt->data + pkt->length - len, data, len);
1563 static void ssh2_pkt_addbyte(struct Packet *pkt, unsigned char byte)
1565 ssh2_pkt_adddata(pkt, &byte, 1);
1567 static struct Packet *ssh2_pkt_init(int pkt_type)
1569 struct Packet *pkt = ssh_new_packet();
1571 ssh2_pkt_addbyte(pkt, (unsigned char) pkt_type);
1574 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
1576 ssh2_pkt_adddata(pkt, &value, 1);
1578 static void ssh2_pkt_adduint32(struct Packet *pkt, unsigned long value)
1581 PUT_32BIT(x, value);
1582 ssh2_pkt_adddata(pkt, x, 4);
1584 static void ssh2_pkt_addstring_start(struct Packet *pkt)
1586 ssh2_pkt_adduint32(pkt, 0);
1587 pkt->savedpos = pkt->length;
1589 static void ssh2_pkt_addstring_str(struct Packet *pkt, char *data)
1591 ssh2_pkt_adddata(pkt, data, strlen(data));
1592 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1594 static void ssh2_pkt_addstring_data(struct Packet *pkt, char *data, int len)
1596 ssh2_pkt_adddata(pkt, data, len);
1597 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1599 static void ssh2_pkt_addstring(struct Packet *pkt, char *data)
1601 ssh2_pkt_addstring_start(pkt);
1602 ssh2_pkt_addstring_str(pkt, data);
1604 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1607 int i, n = (bignum_bitcount(b) + 7) / 8;
1608 p = snewn(n + 1, unsigned char);
1610 fatalbox("out of memory");
1612 for (i = 1; i <= n; i++)
1613 p[i] = bignum_byte(b, n - i);
1615 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1617 memmove(p, p + i, n + 1 - i);
1621 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
1625 p = ssh2_mpint_fmt(b, &len);
1626 ssh2_pkt_addstring_start(pkt);
1627 ssh2_pkt_addstring_data(pkt, (char *)p, len);
1632 * Construct an SSH2 final-form packet: compress it, encrypt it,
1633 * put the MAC on it. Final packet, ready to be sent, is stored in
1634 * pkt->data. Total length is returned.
1636 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
1638 int cipherblk, maclen, padding, i;
1641 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1642 ssh2_pkt_type(ssh->pkt_ctx, pkt->data[5]),
1643 pkt->data + 6, pkt->length - 6,
1644 pkt->nblanks, pkt->blanks);
1645 sfree(pkt->blanks); pkt->blanks = NULL;
1649 * Compress packet payload.
1652 unsigned char *newpayload;
1655 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1657 &newpayload, &newlen)) {
1659 ssh2_pkt_adddata(pkt, newpayload, newlen);
1665 * Add padding. At least four bytes, and must also bring total
1666 * length (minus MAC) up to a multiple of the block size.
1668 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1669 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1672 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
1673 maclen = ssh->csmac ? ssh->csmac->len : 0;
1674 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1675 pkt->data[4] = padding;
1676 for (i = 0; i < padding; i++)
1677 pkt->data[pkt->length + i] = random_byte();
1678 PUT_32BIT(pkt->data, pkt->length + padding - 4);
1680 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1681 pkt->length + padding,
1682 ssh->v2_outgoing_sequence);
1683 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1686 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1687 pkt->data, pkt->length + padding);
1689 pkt->encrypted_len = pkt->length + padding;
1691 /* Ready-to-send packet starts at pkt->data. We return length. */
1692 return pkt->length + padding + maclen;
1696 * Routines called from the main SSH code to send packets. There
1697 * are quite a few of these, because we have two separate
1698 * mechanisms for delaying the sending of packets:
1700 * - In order to send an IGNORE message and a password message in
1701 * a single fixed-length blob, we require the ability to
1702 * concatenate the encrypted forms of those two packets _into_ a
1703 * single blob and then pass it to our <network.h> transport
1704 * layer in one go. Hence, there's a deferment mechanism which
1705 * works after packet encryption.
1707 * - In order to avoid sending any connection-layer messages
1708 * during repeat key exchange, we have to queue up any such
1709 * outgoing messages _before_ they are encrypted (and in
1710 * particular before they're allocated sequence numbers), and
1711 * then send them once we've finished.
1713 * I call these mechanisms `defer' and `queue' respectively, so as
1714 * to distinguish them reasonably easily.
1716 * The functions send_noqueue() and defer_noqueue() free the packet
1717 * structure they are passed. Every outgoing packet goes through
1718 * precisely one of these functions in its life; packets passed to
1719 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
1720 * these or get queued, and then when the queue is later emptied
1721 * the packets are all passed to defer_noqueue().
1725 * Send an SSH2 packet immediately, without queuing or deferring.
1727 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
1731 len = ssh2_pkt_construct(ssh, pkt);
1732 backlog = sk_write(ssh->s, (char *)pkt->data, len);
1733 if (backlog > SSH_MAX_BACKLOG)
1734 ssh_throttle_all(ssh, 1, backlog);
1736 ssh->outgoing_data_size += pkt->encrypted_len;
1737 if (!ssh->kex_in_progress &&
1738 ssh->max_data_size != 0 &&
1739 ssh->outgoing_data_size > ssh->max_data_size)
1740 do_ssh2_transport(ssh, "Initiating key re-exchange "
1741 "(too much data sent)", -1, NULL);
1743 ssh_free_packet(pkt);
1747 * Defer an SSH2 packet.
1749 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt)
1751 int len = ssh2_pkt_construct(ssh, pkt);
1752 if (ssh->deferred_len + len > ssh->deferred_size) {
1753 ssh->deferred_size = ssh->deferred_len + len + 128;
1754 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1758 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
1759 ssh->deferred_len += len;
1760 ssh->deferred_data_size += pkt->encrypted_len;
1761 ssh_free_packet(pkt);
1765 * Queue an SSH2 packet.
1767 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
1769 assert(ssh->queueing);
1771 if (ssh->queuelen >= ssh->queuesize) {
1772 ssh->queuesize = ssh->queuelen + 32;
1773 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
1776 ssh->queue[ssh->queuelen++] = pkt;
1780 * Either queue or send a packet, depending on whether queueing is
1783 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
1786 ssh2_pkt_queue(ssh, pkt);
1788 ssh2_pkt_send_noqueue(ssh, pkt);
1792 * Either queue or defer a packet, depending on whether queueing is
1795 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
1798 ssh2_pkt_queue(ssh, pkt);
1800 ssh2_pkt_defer_noqueue(ssh, pkt);
1804 * Send the whole deferred data block constructed by
1805 * ssh2_pkt_defer() or SSH1's defer_packet().
1807 * The expected use of the defer mechanism is that you call
1808 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
1809 * not currently queueing, this simply sets up deferred_send_data
1810 * and then sends it. If we _are_ currently queueing, the calls to
1811 * ssh2_pkt_defer() put the deferred packets on to the queue
1812 * instead, and therefore ssh_pkt_defersend() has no deferred data
1813 * to send. Hence, there's no need to make it conditional on
1816 static void ssh_pkt_defersend(Ssh ssh)
1819 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1821 ssh->deferred_len = ssh->deferred_size = 0;
1822 sfree(ssh->deferred_send_data);
1823 ssh->deferred_send_data = NULL;
1824 if (backlog > SSH_MAX_BACKLOG)
1825 ssh_throttle_all(ssh, 1, backlog);
1827 ssh->outgoing_data_size += ssh->deferred_data_size;
1828 if (!ssh->kex_in_progress &&
1829 ssh->max_data_size != 0 &&
1830 ssh->outgoing_data_size > ssh->max_data_size)
1831 do_ssh2_transport(ssh, "Initiating key re-exchange "
1832 "(too much data sent)", -1, NULL);
1833 ssh->deferred_data_size = 0;
1837 * Send all queued SSH2 packets. We send them by means of
1838 * ssh2_pkt_defer_noqueue(), in case they included a pair of
1839 * packets that needed to be lumped together.
1841 static void ssh2_pkt_queuesend(Ssh ssh)
1845 assert(!ssh->queueing);
1847 for (i = 0; i < ssh->queuelen; i++)
1848 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i]);
1851 ssh_pkt_defersend(ssh);
1855 void bndebug(char *string, Bignum b)
1859 p = ssh2_mpint_fmt(b, &len);
1860 debug(("%s", string));
1861 for (i = 0; i < len; i++)
1862 debug((" %02x", p[i]));
1868 static void sha_mpint(SHA_State * s, Bignum b)
1872 p = ssh2_mpint_fmt(b, &len);
1873 sha_string(s, p, len);
1878 * Packet decode functions for both SSH1 and SSH2.
1880 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
1882 unsigned long value;
1883 if (pkt->length - pkt->savedpos < 4)
1884 return 0; /* arrgh, no way to decline (FIXME?) */
1885 value = GET_32BIT(pkt->body + pkt->savedpos);
1889 static int ssh2_pkt_getbool(struct Packet *pkt)
1891 unsigned long value;
1892 if (pkt->length - pkt->savedpos < 1)
1893 return 0; /* arrgh, no way to decline (FIXME?) */
1894 value = pkt->body[pkt->savedpos] != 0;
1898 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
1903 if (pkt->length - pkt->savedpos < 4)
1905 len = GET_32BIT(pkt->body + pkt->savedpos);
1910 if (pkt->length - pkt->savedpos < *length)
1912 *p = (char *)(pkt->body + pkt->savedpos);
1913 pkt->savedpos += *length;
1915 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
1917 if (pkt->length - pkt->savedpos < length)
1919 pkt->savedpos += length;
1920 return pkt->body + (pkt->savedpos - length);
1922 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
1923 unsigned char **keystr)
1927 j = makekey(pkt->body + pkt->savedpos,
1928 pkt->length - pkt->savedpos,
1935 assert(pkt->savedpos < pkt->length);
1939 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
1944 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
1945 pkt->length - pkt->savedpos, &b);
1953 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
1959 ssh_pkt_getstring(pkt, &p, &length);
1964 b = bignum_from_bytes((unsigned char *)p, length);
1969 * Helper function to add an SSH2 signature blob to a packet.
1970 * Expects to be shown the public key blob as well as the signature
1971 * blob. Normally works just like ssh2_pkt_addstring, but will
1972 * fiddle with the signature packet if necessary for
1973 * BUG_SSH2_RSA_PADDING.
1975 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
1976 void *pkblob_v, int pkblob_len,
1977 void *sigblob_v, int sigblob_len)
1979 unsigned char *pkblob = (unsigned char *)pkblob_v;
1980 unsigned char *sigblob = (unsigned char *)sigblob_v;
1982 /* dmemdump(pkblob, pkblob_len); */
1983 /* dmemdump(sigblob, sigblob_len); */
1986 * See if this is in fact an ssh-rsa signature and a buggy
1987 * server; otherwise we can just do this the easy way.
1989 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1990 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1991 int pos, len, siglen;
1994 * Find the byte length of the modulus.
1997 pos = 4+7; /* skip over "ssh-rsa" */
1998 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1999 len = GET_32BIT(pkblob+pos); /* find length of modulus */
2000 pos += 4; /* find modulus itself */
2001 while (len > 0 && pkblob[pos] == 0)
2003 /* debug(("modulus length is %d\n", len)); */
2006 * Now find the signature integer.
2008 pos = 4+7; /* skip over "ssh-rsa" */
2009 siglen = GET_32BIT(sigblob+pos);
2010 /* debug(("signature length is %d\n", siglen)); */
2012 if (len != siglen) {
2013 unsigned char newlen[4];
2014 ssh2_pkt_addstring_start(pkt);
2015 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2016 /* dmemdump(sigblob, pos); */
2017 pos += 4; /* point to start of actual sig */
2018 PUT_32BIT(newlen, len);
2019 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2020 /* dmemdump(newlen, 4); */
2022 while (len-- > siglen) {
2023 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2024 /* dmemdump(newlen, 1); */
2026 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2027 /* dmemdump(sigblob+pos, siglen); */
2031 /* Otherwise fall through and do it the easy way. */
2034 ssh2_pkt_addstring_start(pkt);
2035 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2039 * Examine the remote side's version string and compare it against
2040 * a list of known buggy implementations.
2042 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2044 char *imp; /* pointer to implementation part */
2046 imp += strcspn(imp, "-");
2048 imp += strcspn(imp, "-");
2051 ssh->remote_bugs = 0;
2053 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
2054 (ssh->cfg.sshbug_ignore1 == AUTO &&
2055 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2056 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2057 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2058 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2060 * These versions don't support SSH1_MSG_IGNORE, so we have
2061 * to use a different defence against password length
2064 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2065 logevent("We believe remote version has SSH1 ignore bug");
2068 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
2069 (ssh->cfg.sshbug_plainpw1 == AUTO &&
2070 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2072 * These versions need a plain password sent; they can't
2073 * handle having a null and a random length of data after
2076 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2077 logevent("We believe remote version needs a plain SSH1 password");
2080 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
2081 (ssh->cfg.sshbug_rsa1 == AUTO &&
2082 (!strcmp(imp, "Cisco-1.25")))) {
2084 * These versions apparently have no clue whatever about
2085 * RSA authentication and will panic and die if they see
2086 * an AUTH_RSA message.
2088 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2089 logevent("We believe remote version can't handle RSA authentication");
2092 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2093 (ssh->cfg.sshbug_hmac2 == AUTO &&
2094 !wc_match("* VShell", imp) &&
2095 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2096 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2097 wc_match("2.1 *", imp)))) {
2099 * These versions have the HMAC bug.
2101 ssh->remote_bugs |= BUG_SSH2_HMAC;
2102 logevent("We believe remote version has SSH2 HMAC bug");
2105 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2106 (ssh->cfg.sshbug_derivekey2 == AUTO &&
2107 !wc_match("* VShell", imp) &&
2108 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2110 * These versions have the key-derivation bug (failing to
2111 * include the literal shared secret in the hashes that
2112 * generate the keys).
2114 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2115 logevent("We believe remote version has SSH2 key-derivation bug");
2118 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2119 (ssh->cfg.sshbug_rsapad2 == AUTO &&
2120 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2121 wc_match("OpenSSH_3.[0-2]*", imp)))) {
2123 * These versions have the SSH2 RSA padding bug.
2125 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2126 logevent("We believe remote version has SSH2 RSA padding bug");
2129 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2130 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2131 wc_match("OpenSSH_2.[0-2]*", imp))) {
2133 * These versions have the SSH2 session-ID bug in
2134 * public-key authentication.
2136 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2137 logevent("We believe remote version has SSH2 public-key-session-ID bug");
2142 * The `software version' part of an SSH version string is required
2143 * to contain no spaces or minus signs.
2145 static void ssh_fix_verstring(char *str)
2147 /* Eat "SSH-<protoversion>-". */
2148 assert(*str == 'S'); str++;
2149 assert(*str == 'S'); str++;
2150 assert(*str == 'H'); str++;
2151 assert(*str == '-'); str++;
2152 while (*str && *str != '-') str++;
2153 assert(*str == '-'); str++;
2155 /* Convert minus signs and spaces in the remaining string into
2158 if (*str == '-' || *str == ' ')
2164 static int do_ssh_init(Ssh ssh, unsigned char c)
2166 struct do_ssh_init_state {
2174 crState(do_ssh_init_state);
2176 crBegin(ssh->do_ssh_init_crstate);
2178 /* Search for the string "SSH-" in the input. */
2181 static const int transS[] = { 1, 2, 2, 1 };
2182 static const int transH[] = { 0, 0, 3, 0 };
2183 static const int transminus[] = { 0, 0, 0, -1 };
2185 s->i = transS[s->i];
2187 s->i = transH[s->i];
2189 s->i = transminus[s->i];
2194 crReturn(1); /* get another character */
2198 s->vstring = snewn(s->vstrsize, char);
2199 strcpy(s->vstring, "SSH-");
2203 crReturn(1); /* get another char */
2204 if (s->vslen >= s->vstrsize - 1) {
2206 s->vstring = sresize(s->vstring, s->vstrsize, char);
2208 s->vstring[s->vslen++] = c;
2211 s->version[s->i] = '\0';
2213 } else if (s->i < sizeof(s->version) - 1)
2214 s->version[s->i++] = c;
2215 } else if (c == '\012')
2219 ssh->agentfwd_enabled = FALSE;
2220 ssh->rdpkt2_state.incoming_sequence = 0;
2222 s->vstring[s->vslen] = 0;
2223 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2226 vlog = snewn(20 + s->vslen, char);
2227 sprintf(vlog, "Server version: %s", s->vstring);
2231 ssh_detect_bugs(ssh, s->vstring);
2234 * Decide which SSH protocol version to support.
2237 /* Anything strictly below "2.0" means protocol 1 is supported. */
2238 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2239 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2240 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2242 if (ssh->cfg.sshprot == 0 && !s->proto1) {
2243 bombout(("SSH protocol version 1 required by user but not provided by server"));
2246 if (ssh->cfg.sshprot == 3 && !s->proto2) {
2247 bombout(("SSH protocol version 2 required by user but not provided by server"));
2254 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2256 * Construct a v2 version string.
2258 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2262 * Construct a v1 version string.
2264 verstring = dupprintf("SSH-%s-%s\012",
2265 (ssh_versioncmp(s->version, "1.5") <= 0 ?
2266 s->version : "1.5"),
2271 ssh_fix_verstring(verstring);
2273 if (ssh->version == 2) {
2275 * Hash our version string and their version string.
2277 SHA_Init(&ssh->exhashbase);
2278 sha_string(&ssh->exhashbase, verstring,
2279 strcspn(verstring, "\015\012"));
2280 sha_string(&ssh->exhashbase, s->vstring,
2281 strcspn(s->vstring, "\015\012"));
2284 * Initialise SSHv2 protocol.
2286 ssh->protocol = ssh2_protocol;
2287 ssh2_protocol_setup(ssh);
2288 ssh->s_rdpkt = ssh2_rdpkt;
2291 * Initialise SSHv1 protocol.
2293 ssh->protocol = ssh1_protocol;
2294 ssh1_protocol_setup(ssh);
2295 ssh->s_rdpkt = ssh1_rdpkt;
2297 logeventf(ssh, "We claim version: %.*s",
2298 strcspn(verstring, "\015\012"), verstring);
2299 sk_write(ssh->s, verstring, strlen(verstring));
2303 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2305 update_specials_menu(ssh->frontend);
2306 ssh->state = SSH_STATE_BEFORE_SIZE;
2307 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
2314 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2316 crBegin(ssh->ssh_gotdata_crstate);
2319 * To begin with, feed the characters one by one to the
2320 * protocol initialisation / selection function do_ssh_init().
2321 * When that returns 0, we're done with the initial greeting
2322 * exchange and can move on to packet discipline.
2325 int ret; /* need not be kept across crReturn */
2327 crReturnV; /* more data please */
2328 ret = do_ssh_init(ssh, *data);
2336 * We emerge from that loop when the initial negotiation is
2337 * over and we have selected an s_rdpkt function. Now pass
2338 * everything to s_rdpkt, and then pass the resulting packets
2339 * to the proper protocol handler.
2344 while (datalen > 0) {
2345 struct Packet *pktin = ssh->s_rdpkt(ssh, &data, &datalen);
2347 ssh->protocol(ssh, NULL, 0, pktin);
2348 ssh_free_packet(pktin);
2350 if (ssh->state == SSH_STATE_CLOSED)
2358 static void ssh_do_close(Ssh ssh)
2361 struct ssh_channel *c;
2363 ssh->state = SSH_STATE_CLOSED;
2367 notify_remote_exit(ssh->frontend);
2370 * Now we must shut down any port and X forwardings going
2371 * through this connection.
2373 if (ssh->channels) {
2374 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2377 x11_close(c->u.x11.s);
2380 pfd_close(c->u.pfd.s);
2383 del234(ssh->channels, c);
2384 if (ssh->version == 2)
2385 bufchain_clear(&c->v.v2.outbuffer);
2391 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2394 Ssh ssh = (Ssh) plug;
2397 /* A socket error has occurred. */
2398 logevent(error_msg);
2399 connection_fatal(ssh->frontend, "%s", error_msg);
2401 /* Otherwise, the remote side closed the connection normally. */
2406 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2408 Ssh ssh = (Ssh) plug;
2409 ssh_gotdata(ssh, (unsigned char *)data, len);
2410 if (ssh->state == SSH_STATE_CLOSED) {
2417 static void ssh_sent(Plug plug, int bufsize)
2419 Ssh ssh = (Ssh) plug;
2421 * If the send backlog on the SSH socket itself clears, we
2422 * should unthrottle the whole world if it was throttled.
2424 if (bufsize < SSH_MAX_BACKLOG)
2425 ssh_throttle_all(ssh, 0, bufsize);
2429 * Connect to specified host and port.
2430 * Returns an error message, or NULL on success.
2431 * Also places the canonical host name into `realhost'. It must be
2432 * freed by the caller.
2434 static const char *connect_to_host(Ssh ssh, char *host, int port,
2435 char **realhost, int nodelay, int keepalive)
2437 static const struct plug_function_table fn_table = {
2447 ssh->savedhost = snewn(1 + strlen(host), char);
2448 if (!ssh->savedhost)
2449 fatalbox("Out of memory");
2450 strcpy(ssh->savedhost, host);
2453 port = 22; /* default ssh port */
2454 ssh->savedport = port;
2459 logeventf(ssh, "Looking up host \"%s\"%s", host,
2460 (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
2461 (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
2462 addr = name_lookup(host, port, realhost, &ssh->cfg,
2463 ssh->cfg.addressfamily);
2464 if ((err = sk_addr_error(addr)) != NULL) {
2474 sk_getaddr(addr, addrbuf, 100);
2475 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
2477 ssh->fn = &fn_table;
2478 ssh->s = new_connection(addr, *realhost, port,
2479 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
2480 if ((err = sk_socket_error(ssh->s)) != NULL) {
2482 notify_remote_exit(ssh->frontend);
2490 * Throttle or unthrottle the SSH connection.
2492 static void ssh1_throttle(Ssh ssh, int adjust)
2494 int old_count = ssh->v1_throttle_count;
2495 ssh->v1_throttle_count += adjust;
2496 assert(ssh->v1_throttle_count >= 0);
2497 if (ssh->v1_throttle_count && !old_count) {
2498 sk_set_frozen(ssh->s, 1);
2499 } else if (!ssh->v1_throttle_count && old_count) {
2500 sk_set_frozen(ssh->s, 0);
2505 * Throttle or unthrottle _all_ local data streams (for when sends
2506 * on the SSH connection itself back up).
2508 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2511 struct ssh_channel *c;
2513 if (enable == ssh->throttled_all)
2515 ssh->throttled_all = enable;
2516 ssh->overall_bufsize = bufsize;
2519 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2521 case CHAN_MAINSESSION:
2523 * This is treated separately, outside the switch.
2527 x11_override_throttle(c->u.x11.s, enable);
2530 /* Agent channels require no buffer management. */
2533 pfd_override_throttle(c->u.pfd.s, enable);
2540 * Username and password input, abstracted off into routines
2541 * reusable in several places - even between SSH1 and SSH2.
2544 /* Set up a username or password input loop on a given buffer. */
2545 static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2547 ssh->userpass_input_buffer = buffer;
2548 ssh->userpass_input_buflen = buflen;
2549 ssh->userpass_input_bufpos = 0;
2550 ssh->userpass_input_echo = echo;
2554 * Process some terminal data in the course of username/password
2555 * input. Returns >0 for success (line of input returned in
2556 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2557 * for inconclusive (keep waiting for more input please).
2559 static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2564 switch (c = *in++) {
2567 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2568 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2573 if (ssh->userpass_input_bufpos > 0) {
2574 if (ssh->userpass_input_echo)
2575 c_write_str(ssh, "\b \b");
2576 ssh->userpass_input_bufpos--;
2581 while (ssh->userpass_input_bufpos > 0) {
2582 if (ssh->userpass_input_echo)
2583 c_write_str(ssh, "\b \b");
2584 ssh->userpass_input_bufpos--;
2593 * This simplistic check for printability is disabled
2594 * when we're doing password input, because some people
2595 * have control characters in their passwords.o
2597 if ((!ssh->userpass_input_echo ||
2598 (c >= ' ' && c <= '~') ||
2599 ((unsigned char) c >= 160))
2600 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2601 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2602 if (ssh->userpass_input_echo)
2603 c_write(ssh, &c, 1);
2611 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
2613 Ssh ssh = (Ssh) sshv;
2615 ssh->agent_response = reply;
2616 ssh->agent_response_len = replylen;
2618 if (ssh->version == 1)
2619 do_ssh1_login(ssh, NULL, -1, NULL);
2621 do_ssh2_authconn(ssh, NULL, -1, NULL);
2624 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
2626 struct ssh_channel *c = (struct ssh_channel *)cv;
2628 void *sentreply = reply;
2631 /* Fake SSH_AGENT_FAILURE. */
2632 sentreply = "\0\0\0\1\5";
2635 if (ssh->version == 2) {
2636 ssh2_add_channel_data(c, sentreply, replylen);
2639 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2640 PKT_INT, c->remoteid,
2643 PKT_DATA, sentreply, replylen,
2652 * Handle the key exchange and user authentication phases.
2654 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2655 struct Packet *pktin)
2658 unsigned char cookie[8], *ptr;
2659 struct RSAKey servkey, hostkey;
2660 struct MD5Context md5c;
2661 struct do_ssh1_login_state {
2663 unsigned char *rsabuf, *keystr1, *keystr2;
2664 unsigned long supported_ciphers_mask, supported_auths_mask;
2665 int tried_publickey, tried_agent;
2666 int tis_auth_refused, ccard_auth_refused;
2667 unsigned char session_id[16];
2670 void *publickey_blob;
2671 int publickey_bloblen;
2677 unsigned char request[5], *response, *p;
2686 crState(do_ssh1_login_state);
2688 crBegin(ssh->do_ssh1_login_crstate);
2693 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
2694 bombout(("Public key packet not received"));
2698 logevent("Received public keys");
2700 ptr = ssh_pkt_getdata(pktin, 8);
2702 bombout(("SSH1 public key packet stopped before random cookie"));
2705 memcpy(cookie, ptr, 8);
2707 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2708 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
2709 bombout(("Failed to read SSH1 public keys from public key packet"));
2714 * Log the host key fingerprint.
2718 logevent("Host key fingerprint is:");
2719 strcpy(logmsg, " ");
2720 hostkey.comment = NULL;
2721 rsa_fingerprint(logmsg + strlen(logmsg),
2722 sizeof(logmsg) - strlen(logmsg), &hostkey);
2726 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2727 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2728 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
2730 ssh->v1_local_protoflags =
2731 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2732 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2735 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2736 MD5Update(&md5c, s->keystr1, servkey.bytes);
2737 MD5Update(&md5c, cookie, 8);
2738 MD5Final(s->session_id, &md5c);
2740 for (i = 0; i < 32; i++)
2741 ssh->session_key[i] = random_byte();
2744 * Verify that the `bits' and `bytes' parameters match.
2746 if (hostkey.bits > hostkey.bytes * 8 ||
2747 servkey.bits > servkey.bytes * 8) {
2748 bombout(("SSH1 public keys were badly formatted"));
2752 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2754 s->rsabuf = snewn(s->len, unsigned char);
2756 fatalbox("Out of memory");
2759 * Verify the host key.
2763 * First format the key into a string.
2765 int len = rsastr_len(&hostkey);
2766 char fingerprint[100];
2767 char *keystr = snewn(len, char);
2769 fatalbox("Out of memory");
2770 rsastr_fmt(keystr, &hostkey);
2771 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2772 verify_ssh_host_key(ssh->frontend,
2773 ssh->savedhost, ssh->savedport, "rsa", keystr,
2778 for (i = 0; i < 32; i++) {
2779 s->rsabuf[i] = ssh->session_key[i];
2781 s->rsabuf[i] ^= s->session_id[i];
2784 if (hostkey.bytes > servkey.bytes) {
2785 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2787 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2789 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
2791 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2794 bombout(("SSH1 public key encryptions failed due to bad formatting"));
2798 logevent("Encrypted session key");
2801 int cipher_chosen = 0, warn = 0;
2802 char *cipher_string = NULL;
2804 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2805 int next_cipher = ssh->cfg.ssh_cipherlist[i];
2806 if (next_cipher == CIPHER_WARN) {
2807 /* If/when we choose a cipher, warn about it */
2809 } else if (next_cipher == CIPHER_AES) {
2810 /* XXX Probably don't need to mention this. */
2811 logevent("AES not supported in SSH1, skipping");
2813 switch (next_cipher) {
2814 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
2815 cipher_string = "3DES"; break;
2816 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
2817 cipher_string = "Blowfish"; break;
2818 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
2819 cipher_string = "single-DES"; break;
2821 if (s->supported_ciphers_mask & (1 << s->cipher_type))
2825 if (!cipher_chosen) {
2826 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2827 bombout(("Server violates SSH 1 protocol by not "
2828 "supporting 3DES encryption"));
2830 /* shouldn't happen */
2831 bombout(("No supported ciphers found"));
2835 /* Warn about chosen cipher if necessary. */
2837 askalg(ssh->frontend, "cipher", cipher_string);
2840 switch (s->cipher_type) {
2841 case SSH_CIPHER_3DES:
2842 logevent("Using 3DES encryption");
2844 case SSH_CIPHER_DES:
2845 logevent("Using single-DES encryption");
2847 case SSH_CIPHER_BLOWFISH:
2848 logevent("Using Blowfish encryption");
2852 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2853 PKT_CHAR, s->cipher_type,
2854 PKT_DATA, cookie, 8,
2855 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2856 PKT_DATA, s->rsabuf, s->len,
2857 PKT_INT, ssh->v1_local_protoflags, PKT_END);
2859 logevent("Trying to enable encryption...");
2863 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2864 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2866 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2867 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
2868 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
2870 ssh->crcda_ctx = crcda_make_context();
2871 logevent("Installing CRC compensation attack detector");
2873 if (servkey.modulus) {
2874 sfree(servkey.modulus);
2875 servkey.modulus = NULL;
2877 if (servkey.exponent) {
2878 sfree(servkey.exponent);
2879 servkey.exponent = NULL;
2881 if (hostkey.modulus) {
2882 sfree(hostkey.modulus);
2883 hostkey.modulus = NULL;
2885 if (hostkey.exponent) {
2886 sfree(hostkey.exponent);
2887 hostkey.exponent = NULL;
2891 if (pktin->type != SSH1_SMSG_SUCCESS) {
2892 bombout(("Encryption not successfully enabled"));
2896 logevent("Successfully started encryption");
2900 if (!*ssh->cfg.username) {
2901 if (ssh_get_line && !ssh_getline_pw_only) {
2902 if (!ssh_get_line("login as: ",
2903 s->username, sizeof(s->username), FALSE)) {
2905 * get_line failed to get a username.
2908 logevent("No username provided. Abandoning session.");
2909 ssh_closing((Plug)ssh, NULL, 0, 0);
2913 int ret; /* need not be kept over crReturn */
2914 c_write_str(ssh, "login as: ");
2917 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
2919 crWaitUntil(!pktin);
2920 ret = process_userpass_input(ssh, in, inlen);
2924 c_write_str(ssh, "\r\n");
2927 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
2928 s->username[sizeof(s->username)-1] = '\0';
2931 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
2933 char userlog[22 + sizeof(s->username)];
2934 sprintf(userlog, "Sent username \"%s\"", s->username);
2936 if (flags & FLAG_INTERACTIVE &&
2937 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2938 strcat(userlog, "\r\n");
2939 c_write_str(ssh, userlog);
2946 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
2947 /* We must not attempt PK auth. Pretend we've already tried it. */
2948 s->tried_publickey = s->tried_agent = 1;
2950 s->tried_publickey = s->tried_agent = 0;
2952 s->tis_auth_refused = s->ccard_auth_refused = 0;
2953 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
2954 if (!filename_is_null(ssh->cfg.keyfile)) {
2955 if (!rsakey_pubblob(&ssh->cfg.keyfile,
2956 &s->publickey_blob, &s->publickey_bloblen, NULL))
2957 s->publickey_blob = NULL;
2959 s->publickey_blob = NULL;
2961 while (pktin->type == SSH1_SMSG_FAILURE) {
2962 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2964 if (agent_exists() && !s->tried_agent) {
2966 * Attempt RSA authentication using Pageant.
2972 logevent("Pageant is running. Requesting keys.");
2974 /* Request the keys held by the agent. */
2975 PUT_32BIT(s->request, 1);
2976 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2977 if (!agent_query(s->request, 5, &r, &s->responselen,
2978 ssh_agent_callback, ssh)) {
2982 bombout(("Unexpected data from server while waiting"
2983 " for agent response"));
2986 } while (pktin || inlen > 0);
2987 r = ssh->agent_response;
2988 s->responselen = ssh->agent_response_len;
2990 s->response = (unsigned char *) r;
2991 if (s->response && s->responselen >= 5 &&
2992 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2993 s->p = s->response + 5;
2994 s->nkeys = GET_32BIT(s->p);
2998 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
3001 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
3004 sprintf(buf, "Trying Pageant key #%d", s->keyi);
3007 if (s->publickey_blob &&
3008 !memcmp(s->p, s->publickey_blob,
3009 s->publickey_bloblen)) {
3010 logevent("This key matches configured key file");
3011 s->tried_publickey = 1;
3016 do { /* do while (0) to make breaking easy */
3017 n = ssh1_read_bignum
3018 (s->p, s->responselen-(s->p-s->response),
3023 n = ssh1_read_bignum
3024 (s->p, s->responselen-(s->p-s->response),
3029 if (s->responselen - (s->p-s->response) < 4)
3031 s->commentlen = GET_32BIT(s->p);
3033 if (s->responselen - (s->p-s->response) <
3036 s->commentp = (char *)s->p;
3037 s->p += s->commentlen;
3041 logevent("Pageant key list packet was truncated");
3045 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3046 PKT_BIGNUM, s->key.modulus, PKT_END);
3048 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3049 logevent("Key refused");
3052 logevent("Received RSA challenge");
3053 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3054 bombout(("Server's RSA challenge was badly formatted"));
3059 char *agentreq, *q, *ret;
3062 len = 1 + 4; /* message type, bit count */
3063 len += ssh1_bignum_length(s->key.exponent);
3064 len += ssh1_bignum_length(s->key.modulus);
3065 len += ssh1_bignum_length(s->challenge);
3066 len += 16; /* session id */
3067 len += 4; /* response format */
3068 agentreq = snewn(4 + len, char);
3069 PUT_32BIT(agentreq, len);
3071 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
3072 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
3074 q += ssh1_write_bignum(q, s->key.exponent);
3075 q += ssh1_write_bignum(q, s->key.modulus);
3076 q += ssh1_write_bignum(q, s->challenge);
3077 memcpy(q, s->session_id, 16);
3079 PUT_32BIT(q, 1); /* response format */
3080 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3081 ssh_agent_callback, ssh)) {
3086 bombout(("Unexpected data from server"
3087 " while waiting for agent"
3091 } while (pktin || inlen > 0);
3092 vret = ssh->agent_response;
3093 retlen = ssh->agent_response_len;
3098 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3099 logevent("Sending Pageant's response");
3100 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3101 PKT_DATA, ret + 5, 16,
3105 if (pktin->type == SSH1_SMSG_SUCCESS) {
3107 ("Pageant's response accepted");
3108 if (flags & FLAG_VERBOSE) {
3109 c_write_str(ssh, "Authenticated using"
3111 c_write(ssh, s->commentp,
3113 c_write_str(ssh, "\" from agent\r\n");
3118 ("Pageant's response not accepted");
3121 ("Pageant failed to answer challenge");
3125 logevent("No reply received from Pageant");
3128 freebn(s->key.exponent);
3129 freebn(s->key.modulus);
3130 freebn(s->challenge);
3139 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
3140 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
3142 if (ssh->cfg.try_tis_auth &&
3143 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3144 !s->tis_auth_refused) {
3145 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
3146 logevent("Requested TIS authentication");
3147 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
3149 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
3150 logevent("TIS authentication declined");
3151 if (flags & FLAG_INTERACTIVE)
3152 c_write_str(ssh, "TIS authentication refused.\r\n");
3153 s->tis_auth_refused = 1;
3159 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3161 bombout(("TIS challenge packet was badly formed"));
3164 logevent("Received TIS challenge");
3165 if (challengelen > sizeof(s->prompt) - 1)
3166 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3167 memcpy(s->prompt, challenge, challengelen);
3168 /* Prompt heuristic comes from OpenSSH */
3169 strncpy(s->prompt + challengelen,
3170 memchr(s->prompt, '\n', challengelen) ?
3171 "": "\r\nResponse: ",
3172 (sizeof s->prompt) - challengelen);
3173 s->prompt[(sizeof s->prompt) - 1] = '\0';
3176 if (ssh->cfg.try_tis_auth &&
3177 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3178 !s->ccard_auth_refused) {
3179 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
3180 logevent("Requested CryptoCard authentication");
3181 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
3183 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
3184 logevent("CryptoCard authentication declined");
3185 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3186 s->ccard_auth_refused = 1;
3192 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3194 bombout(("CryptoCard challenge packet was badly formed"));
3197 logevent("Received CryptoCard challenge");
3198 if (challengelen > sizeof(s->prompt) - 1)
3199 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3200 memcpy(s->prompt, challenge, challengelen);
3201 strncpy(s->prompt + challengelen,
3202 memchr(s->prompt, '\n', challengelen) ?
3203 "" : "\r\nResponse: ",
3204 sizeof(s->prompt) - challengelen);
3205 s->prompt[sizeof(s->prompt) - 1] = '\0';
3208 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3209 sprintf(s->prompt, "%.90s@%.90s's password: ",
3210 s->username, ssh->savedhost);
3212 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3213 char *comment = NULL;
3216 if (flags & FLAG_VERBOSE)
3217 c_write_str(ssh, "Trying public key authentication.\r\n");
3218 logeventf(ssh, "Trying public key \"%s\"",
3219 filename_to_str(&ssh->cfg.keyfile));
3220 type = key_type(&ssh->cfg.keyfile);
3221 if (type != SSH_KEYTYPE_SSH1) {
3222 sprintf(msgbuf, "Key is of wrong type (%s)",
3223 key_type_to_str(type));
3225 c_write_str(ssh, msgbuf);
3226 c_write_str(ssh, "\r\n");
3227 s->tried_publickey = 1;
3230 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
3231 if (flags & FLAG_VERBOSE)
3232 c_write_str(ssh, "No passphrase required.\r\n");
3235 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
3240 * Show password prompt, having first obtained it via a TIS
3241 * or CryptoCard exchange if we're doing TIS or CryptoCard
3245 if (!ssh_get_line(s->prompt, s->password,
3246 sizeof(s->password), TRUE)) {
3248 * get_line failed to get a password (for example
3249 * because one was supplied on the command line
3250 * which has already failed to work). Terminate.
3252 send_packet(ssh, SSH1_MSG_DISCONNECT,
3253 PKT_STR, "No more passwords available to try",
3255 logevent("Unable to authenticate");
3256 connection_fatal(ssh->frontend, "Unable to authenticate");
3257 ssh_closing((Plug)ssh, NULL, 0, 0);
3261 /* Prompt may have come from server. We've munged it a bit, so
3262 * we know it to be zero-terminated at least once. */
3263 int ret; /* need not be saved over crReturn */
3264 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3267 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
3269 crWaitUntil(!pktin);
3270 ret = process_userpass_input(ssh, in, inlen);
3274 c_write_str(ssh, "\r\n");
3278 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3280 * Try public key authentication with the specified
3283 s->tried_publickey = 1;
3286 const char *error = NULL;
3287 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3290 c_write_str(ssh, "Couldn't load private key from ");
3291 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
3292 c_write_str(ssh, " (");
3293 c_write_str(ssh, error);
3294 c_write_str(ssh, ").\r\n");
3295 continue; /* go and try password */
3298 c_write_str(ssh, "Wrong passphrase.\r\n");
3299 s->tried_publickey = 0;
3300 continue; /* try again */
3305 * Send a public key attempt.
3307 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3308 PKT_BIGNUM, s->key.modulus, PKT_END);
3311 if (pktin->type == SSH1_SMSG_FAILURE) {
3312 c_write_str(ssh, "Server refused our public key.\r\n");
3313 continue; /* go and try password */
3315 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3316 bombout(("Bizarre response to offer of public key"));
3322 unsigned char buffer[32];
3323 Bignum challenge, response;
3325 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3326 bombout(("Server's RSA challenge was badly formatted"));
3329 response = rsadecrypt(challenge, &s->key);
3330 freebn(s->key.private_exponent);/* burn the evidence */
3332 for (i = 0; i < 32; i++) {
3333 buffer[i] = bignum_byte(response, 31 - i);
3337 MD5Update(&md5c, buffer, 32);
3338 MD5Update(&md5c, s->session_id, 16);
3339 MD5Final(buffer, &md5c);
3341 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3342 PKT_DATA, buffer, 16, PKT_END);
3349 if (pktin->type == SSH1_SMSG_FAILURE) {
3350 if (flags & FLAG_VERBOSE)
3351 c_write_str(ssh, "Failed to authenticate with"
3352 " our public key.\r\n");
3353 continue; /* go and try password */
3354 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3355 bombout(("Bizarre response to RSA authentication response"));
3359 break; /* we're through! */
3361 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3363 * Defence against traffic analysis: we send a
3364 * whole bunch of packets containing strings of
3365 * different lengths. One of these strings is the
3366 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3367 * The others are all random data in
3368 * SSH1_MSG_IGNORE packets. This way a passive
3369 * listener can't tell which is the password, and
3370 * hence can't deduce the password length.
3372 * Anybody with a password length greater than 16
3373 * bytes is going to have enough entropy in their
3374 * password that a listener won't find it _that_
3375 * much help to know how long it is. So what we'll
3378 * - if password length < 16, we send 15 packets
3379 * containing string lengths 1 through 15
3381 * - otherwise, we let N be the nearest multiple
3382 * of 8 below the password length, and send 8
3383 * packets containing string lengths N through
3384 * N+7. This won't obscure the order of
3385 * magnitude of the password length, but it will
3386 * introduce a bit of extra uncertainty.
3388 * A few servers (the old 1.2.18 through 1.2.22)
3389 * can't deal with SSH1_MSG_IGNORE. For these
3390 * servers, we need an alternative defence. We make
3391 * use of the fact that the password is interpreted
3392 * as a C string: so we can append a NUL, then some
3395 * One server (a Cisco one) can deal with neither
3396 * SSH1_MSG_IGNORE _nor_ a padded password string.
3397 * For this server we are left with no defences
3398 * against password length sniffing.
3400 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
3402 * The server can deal with SSH1_MSG_IGNORE, so
3403 * we can use the primary defence.
3405 int bottom, top, pwlen, i;
3408 pwlen = strlen(s->password);
3410 bottom = 0; /* zero length passwords are OK! :-) */
3413 bottom = pwlen & ~7;
3417 assert(pwlen >= bottom && pwlen <= top);
3419 randomstr = snewn(top + 1, char);
3421 for (i = bottom; i <= top; i++) {
3423 defer_packet(ssh, s->pwpkt_type,
3424 PKTT_PASSWORD, PKT_STR, s->password,
3425 PKTT_OTHER, PKT_END);
3427 for (j = 0; j < i; j++) {
3429 randomstr[j] = random_byte();
3430 } while (randomstr[j] == '\0');
3432 randomstr[i] = '\0';
3433 defer_packet(ssh, SSH1_MSG_IGNORE,
3434 PKT_STR, randomstr, PKT_END);
3437 logevent("Sending password with camouflage packets");
3438 ssh_pkt_defersend(ssh);
3441 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3443 * The server can't deal with SSH1_MSG_IGNORE
3444 * but can deal with padded passwords, so we
3445 * can use the secondary defence.
3451 len = strlen(s->password);
3452 if (len < sizeof(string)) {
3454 strcpy(string, s->password);
3455 len++; /* cover the zero byte */
3456 while (len < sizeof(string)) {
3457 string[len++] = (char) random_byte();
3462 logevent("Sending length-padded password");
3463 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3464 PKT_INT, len, PKT_DATA, ss, len,
3465 PKTT_OTHER, PKT_END);
3468 * The server has _both_
3469 * BUG_CHOKES_ON_SSH1_IGNORE and
3470 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3471 * therefore nothing we can do.
3474 len = strlen(s->password);
3475 logevent("Sending unpadded password");
3476 send_packet(ssh, s->pwpkt_type,
3477 PKTT_PASSWORD, PKT_INT, len,
3478 PKT_DATA, s->password, len,
3479 PKTT_OTHER, PKT_END);
3482 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3483 PKT_STR, s->password, PKTT_OTHER, PKT_END);
3486 logevent("Sent password");
3487 memset(s->password, 0, strlen(s->password));
3489 if (pktin->type == SSH1_SMSG_FAILURE) {
3490 if (flags & FLAG_VERBOSE)
3491 c_write_str(ssh, "Access denied\r\n");
3492 logevent("Authentication refused");
3493 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3494 bombout(("Strange packet received, type %d", pktin->type));
3499 logevent("Authentication successful");
3504 void sshfwd_close(struct ssh_channel *c)
3508 if (ssh->state != SSH_STATE_SESSION) {
3509 assert(ssh->state == SSH_STATE_CLOSED);
3513 if (c && !c->closes) {
3515 * If the channel's remoteid is -1, we have sent
3516 * CHANNEL_OPEN for this channel, but it hasn't even been
3517 * acknowledged by the server. So we must set a close flag
3518 * on it now, and then when the server acks the channel
3519 * open, we can close it then.
3521 if (((int)c->remoteid) != -1) {
3522 if (ssh->version == 1) {
3523 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3526 struct Packet *pktout;
3527 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3528 ssh2_pkt_adduint32(pktout, c->remoteid);
3529 ssh2_pkt_send(ssh, pktout);
3532 c->closes = 1; /* sent MSG_CLOSE */
3533 if (c->type == CHAN_X11) {
3535 logevent("Forwarded X11 connection terminated");
3536 } else if (c->type == CHAN_SOCKDATA ||
3537 c->type == CHAN_SOCKDATA_DORMANT) {
3539 logevent("Forwarded port closed");
3544 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3548 if (ssh->state != SSH_STATE_SESSION) {
3549 assert(ssh->state == SSH_STATE_CLOSED);
3553 if (ssh->version == 1) {
3554 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3555 PKT_INT, c->remoteid,
3557 PKT_INT, len, PKT_DATA, buf, len,
3558 PKTT_OTHER, PKT_END);
3560 * In SSH1 we can return 0 here - implying that forwarded
3561 * connections are never individually throttled - because
3562 * the only circumstance that can cause throttling will be
3563 * the whole SSH connection backing up, in which case
3564 * _everything_ will be throttled as a whole.
3568 ssh2_add_channel_data(c, buf, len);
3569 return ssh2_try_send(c);
3573 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3577 if (ssh->state != SSH_STATE_SESSION) {
3578 assert(ssh->state == SSH_STATE_CLOSED);
3582 if (ssh->version == 1) {
3583 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3584 c->v.v1.throttling = 0;
3585 ssh1_throttle(ssh, -1);
3588 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3592 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
3594 struct queued_handler *qh = ssh->qhead;
3598 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
3601 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
3602 ssh->packet_dispatch[qh->msg1] = NULL;
3605 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
3606 ssh->packet_dispatch[qh->msg2] = NULL;
3610 ssh->qhead = qh->next;
3612 if (ssh->qhead->msg1 > 0) {
3613 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
3614 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
3616 if (ssh->qhead->msg2 > 0) {
3617 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
3618 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
3621 ssh->qhead = ssh->qtail = NULL;
3622 ssh->packet_dispatch[pktin->type] = NULL;
3625 qh->handler(ssh, pktin, qh->ctx);
3630 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
3631 chandler_fn_t handler, void *ctx)
3633 struct queued_handler *qh;
3635 qh = snew(struct queued_handler);
3638 qh->handler = handler;
3642 if (ssh->qtail == NULL) {
3646 assert(ssh->packet_dispatch[qh->msg1] == NULL);
3647 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
3650 assert(ssh->packet_dispatch[qh->msg2] == NULL);
3651 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
3654 ssh->qtail->next = qh;
3659 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
3661 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
3663 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
3664 SSH2_MSG_REQUEST_SUCCESS)) {
3665 logeventf(ssh, "Remote port forwarding from %s enabled",
3668 logeventf(ssh, "Remote port forwarding from %s refused",
3671 rpf = del234(ssh->rportfwds, pf);
3677 static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
3679 const char *portfwd_strptr = cfg->portfwd;
3680 struct ssh_portfwd *epf;
3683 if (!ssh->portfwds) {
3684 ssh->portfwds = newtree234(ssh_portcmp);
3687 * Go through the existing port forwardings and tag them
3688 * with status==DESTROY. Any that we want to keep will be
3689 * re-enabled (status==KEEP) as we go through the
3690 * configuration and find out which bits are the same as
3693 struct ssh_portfwd *epf;
3695 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3696 epf->status = DESTROY;
3699 while (*portfwd_strptr) {
3700 char address_family, type;
3701 int sport,dport,sserv,dserv;
3702 char sports[256], dports[256], saddr[256], host[256];
3705 address_family = 'A';
3707 if (*portfwd_strptr == 'A' ||
3708 *portfwd_strptr == '4' ||
3709 *portfwd_strptr == '6')
3710 address_family = *portfwd_strptr++;
3711 if (*portfwd_strptr == 'L' ||
3712 *portfwd_strptr == 'R' ||
3713 *portfwd_strptr == 'D')
3714 type = *portfwd_strptr++;
3719 while (*portfwd_strptr && *portfwd_strptr != '\t') {
3720 if (*portfwd_strptr == ':') {
3722 * We've seen a colon in the middle of the
3723 * source port number. This means that
3724 * everything we've seen until now is the
3725 * source _address_, so we'll move it into
3726 * saddr and start sports from the beginning
3731 if (ssh->version == 1 && type == 'R') {
3732 logeventf(ssh, "SSH1 cannot handle remote source address "
3733 "spec \"%s\"; ignoring", sports);
3735 strcpy(saddr, sports);
3738 if (n < 255) sports[n++] = *portfwd_strptr++;
3742 if (*portfwd_strptr == '\t')
3745 while (*portfwd_strptr && *portfwd_strptr != ':') {
3746 if (n < 255) host[n++] = *portfwd_strptr++;
3749 if (*portfwd_strptr == ':')
3752 while (*portfwd_strptr) {
3753 if (n < 255) dports[n++] = *portfwd_strptr++;
3757 dport = atoi(dports);
3761 dport = net_service_lookup(dports);
3763 logeventf(ssh, "Service lookup failed for destination"
3764 " port \"%s\"", dports);
3768 while (*portfwd_strptr) portfwd_strptr++;
3770 portfwd_strptr++; /* eat the NUL and move to next one */
3772 sport = atoi(sports);
3776 sport = net_service_lookup(sports);
3778 logeventf(ssh, "Service lookup failed for source"
3779 " port \"%s\"", sports);
3782 if (sport && dport) {
3783 /* Set up a description of the source port. */
3784 struct ssh_portfwd *pfrec, *epfrec;
3786 pfrec = snew(struct ssh_portfwd);
3788 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
3789 pfrec->sserv = sserv ? dupstr(sports) : NULL;
3790 pfrec->sport = sport;
3791 pfrec->daddr = *host ? dupstr(host) : NULL;
3792 pfrec->dserv = dserv ? dupstr(dports) : NULL;
3793 pfrec->dport = dport;
3794 pfrec->local = NULL;
3795 pfrec->remote = NULL;
3796 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
3797 address_family == '6' ? ADDRTYPE_IPV6 :
3800 epfrec = add234(ssh->portfwds, pfrec);
3801 if (epfrec != pfrec) {
3803 * We already have a port forwarding with precisely
3804 * these parameters. Hence, no need to do anything;
3805 * simply tag the existing one as KEEP.
3807 epfrec->status = KEEP;
3808 free_portfwd(pfrec);
3810 pfrec->status = CREATE;
3816 * Now go through and destroy any port forwardings which were
3819 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3820 if (epf->status == DESTROY) {
3823 message = dupprintf("%s port forwarding from %s%s%d",
3824 epf->type == 'L' ? "local" :
3825 epf->type == 'R' ? "remote" : "dynamic",
3826 epf->saddr ? epf->saddr : "",
3827 epf->saddr ? ":" : "",
3830 if (epf->type != 'D') {
3831 char *msg2 = dupprintf("%s to %s:%d", message,
3832 epf->daddr, epf->dport);
3837 logeventf(ssh, "Cancelling %s", message);
3841 struct ssh_rportfwd *rpf = epf->remote;
3842 struct Packet *pktout;
3845 * Cancel the port forwarding at the server
3848 if (ssh->version == 1) {
3850 * We cannot cancel listening ports on the
3851 * server side in SSH1! There's no message
3852 * to support it. Instead, we simply remove
3853 * the rportfwd record from the local end
3854 * so that any connections the server tries
3855 * to make on it are rejected.
3858 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
3859 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
3860 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
3862 ssh2_pkt_addstring(pktout, epf->saddr);
3863 } else if (ssh->cfg.rport_acceptall) {
3864 ssh2_pkt_addstring(pktout, "0.0.0.0");
3866 ssh2_pkt_addstring(pktout, "127.0.0.1");
3868 ssh2_pkt_adduint32(pktout, epf->sport);
3869 ssh2_pkt_send(ssh, pktout);
3872 del234(ssh->rportfwds, rpf);
3874 } else if (epf->local) {
3875 pfd_terminate(epf->local);
3878 delpos234(ssh->portfwds, i);
3880 i--; /* so we don't skip one in the list */
3884 * And finally, set up any new port forwardings (status==CREATE).
3886 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3887 if (epf->status == CREATE) {
3888 char *sportdesc, *dportdesc;
3889 sportdesc = dupprintf("%s%s%s%s%d%s",
3890 epf->saddr ? epf->saddr : "",
3891 epf->saddr ? ":" : "",
3892 epf->sserv ? epf->sserv : "",
3893 epf->sserv ? "(" : "",
3895 epf->sserv ? ")" : "");
3896 if (epf->type == 'D') {
3899 dportdesc = dupprintf("%s:%s%s%d%s",
3901 epf->dserv ? epf->dserv : "",
3902 epf->dserv ? "(" : "",
3904 epf->dserv ? ")" : "");
3907 if (epf->type == 'L') {
3908 const char *err = pfd_addforward(epf->daddr, epf->dport,
3909 epf->saddr, epf->sport,
3912 epf->addressfamily);
3914 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
3915 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
3916 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
3917 sportdesc, dportdesc,
3918 err ? " failed: " : "", err ? err : "");
3919 } else if (epf->type == 'D') {
3920 const char *err = pfd_addforward(NULL, -1,
3921 epf->saddr, epf->sport,
3924 epf->addressfamily);
3926 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
3927 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
3928 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
3930 err ? " failed: " : "", err ? err : "");
3932 struct ssh_rportfwd *pf;
3935 * Ensure the remote port forwardings tree exists.
3937 if (!ssh->rportfwds) {
3938 if (ssh->version == 1)
3939 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3941 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
3944 pf = snew(struct ssh_rportfwd);
3945 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
3946 pf->dhost[lenof(pf->dhost)-1] = '\0';
3947 pf->dport = epf->dport;
3948 pf->sport = epf->sport;
3949 if (add234(ssh->rportfwds, pf) != pf) {
3950 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
3951 epf->daddr, epf->dport);
3954 logeventf(ssh, "Requesting remote port %s"
3955 " forward to %s", sportdesc, dportdesc);
3957 pf->sportdesc = sportdesc;
3962 if (ssh->version == 1) {
3963 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
3964 PKT_INT, epf->sport,
3965 PKT_STR, epf->daddr,
3966 PKT_INT, epf->dport,
3968 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
3970 ssh_rportfwd_succfail, pf);
3972 struct Packet *pktout;
3973 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
3974 ssh2_pkt_addstring(pktout, "tcpip-forward");
3975 ssh2_pkt_addbool(pktout, 1);/* want reply */
3977 ssh2_pkt_addstring(pktout, epf->saddr);
3978 } else if (ssh->cfg.rport_acceptall) {
3979 ssh2_pkt_addstring(pktout, "0.0.0.0");
3981 ssh2_pkt_addstring(pktout, "127.0.0.1");
3983 ssh2_pkt_adduint32(pktout, epf->sport);
3984 ssh2_pkt_send(ssh, pktout);
3986 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
3987 SSH2_MSG_REQUEST_FAILURE,
3988 ssh_rportfwd_succfail, pf);
3997 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4000 int stringlen, bufsize;
4002 ssh_pkt_getstring(pktin, &string, &stringlen);
4003 if (string == NULL) {
4004 bombout(("Incoming terminal data packet was badly formed"));
4008 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4010 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4011 ssh->v1_stdout_throttling = 1;
4012 ssh1_throttle(ssh, +1);
4016 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4018 /* Remote side is trying to open a channel to talk to our
4019 * X-Server. Give them back a local channel number. */
4020 struct ssh_channel *c;
4021 int remoteid = ssh_pkt_getuint32(pktin);
4023 logevent("Received X11 connect request");
4024 /* Refuse if X11 forwarding is disabled. */
4025 if (!ssh->X11_fwd_enabled) {
4026 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4027 PKT_INT, remoteid, PKT_END);
4028 logevent("Rejected X11 connect request");
4030 c = snew(struct ssh_channel);
4033 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
4034 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
4035 logevent("Opening X11 forward connection failed");
4037 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4038 PKT_INT, remoteid, PKT_END);
4041 ("Opening X11 forward connection succeeded");
4042 c->remoteid = remoteid;
4043 c->localid = alloc_channel_id(ssh);
4045 c->v.v1.throttling = 0;
4046 c->type = CHAN_X11; /* identify channel type */
4047 add234(ssh->channels, c);
4048 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4049 PKT_INT, c->remoteid, PKT_INT,
4050 c->localid, PKT_END);
4051 logevent("Opened X11 forward channel");
4056 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4058 /* Remote side is trying to open a channel to talk to our
4059 * agent. Give them back a local channel number. */
4060 struct ssh_channel *c;
4061 int remoteid = ssh_pkt_getuint32(pktin);
4063 /* Refuse if agent forwarding is disabled. */
4064 if (!ssh->agentfwd_enabled) {
4065 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4066 PKT_INT, remoteid, PKT_END);
4068 c = snew(struct ssh_channel);
4070 c->remoteid = remoteid;
4071 c->localid = alloc_channel_id(ssh);
4073 c->v.v1.throttling = 0;
4074 c->type = CHAN_AGENT; /* identify channel type */
4075 c->u.a.lensofar = 0;
4076 add234(ssh->channels, c);
4077 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4078 PKT_INT, c->remoteid, PKT_INT, c->localid,
4083 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4085 /* Remote side is trying to open a channel to talk to a
4086 * forwarded port. Give them back a local channel number. */
4087 struct ssh_channel *c;
4088 struct ssh_rportfwd pf, *pfp;
4091 char *host, buf[1024];
4093 c = snew(struct ssh_channel);
4096 remoteid = ssh_pkt_getuint32(pktin);
4097 ssh_pkt_getstring(pktin, &host, &hostsize);
4098 port = ssh_pkt_getuint32(pktin);
4100 if (hostsize >= lenof(pf.dhost))
4101 hostsize = lenof(pf.dhost)-1;
4102 memcpy(pf.dhost, host, hostsize);
4103 pf.dhost[hostsize] = '\0';
4105 pfp = find234(ssh->rportfwds, &pf, NULL);
4108 sprintf(buf, "Rejected remote port open request for %s:%d",
4111 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4112 PKT_INT, remoteid, PKT_END);
4114 sprintf(buf, "Received remote port open request for %s:%d",
4117 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
4118 c, &ssh->cfg, pfp->pfrec->addressfamily);
4121 sprintf(buf, "Port open failed: %s", e);
4124 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4125 PKT_INT, remoteid, PKT_END);
4127 c->remoteid = remoteid;
4128 c->localid = alloc_channel_id(ssh);
4130 c->v.v1.throttling = 0;
4131 c->type = CHAN_SOCKDATA; /* identify channel type */
4132 add234(ssh->channels, c);
4133 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4134 PKT_INT, c->remoteid, PKT_INT,
4135 c->localid, PKT_END);
4136 logevent("Forwarded port opened successfully");
4141 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4143 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4144 unsigned int localid = ssh_pkt_getuint32(pktin);
4145 struct ssh_channel *c;
4147 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4148 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4149 c->remoteid = localid;
4150 c->type = CHAN_SOCKDATA;
4151 c->v.v1.throttling = 0;
4152 pfd_confirm(c->u.pfd.s);
4155 if (c && c->closes) {
4157 * We have a pending close on this channel,
4158 * which we decided on before the server acked
4159 * the channel open. So now we know the
4160 * remoteid, we can close it again.
4162 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4163 PKT_INT, c->remoteid, PKT_END);
4167 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4169 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4170 struct ssh_channel *c;
4172 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4173 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4174 logevent("Forwarded connection refused by server");
4175 pfd_close(c->u.pfd.s);
4176 del234(ssh->channels, c);
4181 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4183 /* Remote side closes a channel. */
4184 unsigned i = ssh_pkt_getuint32(pktin);
4185 struct ssh_channel *c;
4186 c = find234(ssh->channels, &i, ssh_channelfind);
4187 if (c && ((int)c->remoteid) != -1) {
4190 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4192 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4193 logevent("Forwarded X11 connection terminated");
4194 assert(c->u.x11.s != NULL);
4195 x11_close(c->u.x11.s);
4198 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4199 logevent("Forwarded port closed");
4200 assert(c->u.pfd.s != NULL);
4201 pfd_close(c->u.pfd.s);
4205 c->closes |= (closetype << 2); /* seen this message */
4206 if (!(c->closes & closetype)) {
4207 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4209 c->closes |= closetype; /* sent it too */
4212 if (c->closes == 15) {
4213 del234(ssh->channels, c);
4217 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4218 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4219 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4224 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4226 /* Data sent down one of our channels. */
4227 int i = ssh_pkt_getuint32(pktin);
4230 struct ssh_channel *c;
4232 ssh_pkt_getstring(pktin, &p, &len);
4234 c = find234(ssh->channels, &i, ssh_channelfind);
4239 bufsize = x11_send(c->u.x11.s, p, len);
4242 bufsize = pfd_send(c->u.pfd.s, p, len);
4245 /* Data for an agent message. Buffer it. */
4247 if (c->u.a.lensofar < 4) {
4248 unsigned int l = min(4 - c->u.a.lensofar, len);
4249 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4253 c->u.a.lensofar += l;
4255 if (c->u.a.lensofar == 4) {
4257 4 + GET_32BIT(c->u.a.msglen);
4258 c->u.a.message = snewn(c->u.a.totallen,
4260 memcpy(c->u.a.message, c->u.a.msglen, 4);
4262 if (c->u.a.lensofar >= 4 && len > 0) {
4264 min(c->u.a.totallen - c->u.a.lensofar,
4266 memcpy(c->u.a.message + c->u.a.lensofar, p,
4270 c->u.a.lensofar += l;
4272 if (c->u.a.lensofar == c->u.a.totallen) {
4275 if (agent_query(c->u.a.message,
4278 ssh_agentf_callback, c))
4279 ssh_agentf_callback(c, reply, replylen);
4280 sfree(c->u.a.message);
4281 c->u.a.lensofar = 0;
4284 bufsize = 0; /* agent channels never back up */
4287 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4288 c->v.v1.throttling = 1;
4289 ssh1_throttle(ssh, +1);
4294 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
4297 ssh->exitcode = ssh_pkt_getuint32(pktin);
4298 sprintf(buf, "Server sent command exit status %d",
4301 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4303 * In case `helpful' firewalls or proxies tack
4304 * extra human-readable text on the end of the
4305 * session which we might mistake for another
4306 * encrypted packet, we close the session once
4307 * we've sent EXIT_CONFIRMATION.
4309 ssh_closing((Plug)ssh, NULL, 0, 0);
4312 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
4313 struct Packet *pktin)
4315 crBegin(ssh->do_ssh1_connection_crstate);
4317 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
4318 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
4319 ssh1_smsg_stdout_stderr_data;
4321 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
4322 ssh1_msg_channel_open_confirmation;
4323 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
4324 ssh1_msg_channel_open_failure;
4325 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
4326 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
4327 ssh1_msg_channel_close;
4328 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
4329 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
4331 if (ssh->cfg.agentfwd && agent_exists()) {
4332 logevent("Requesting agent forwarding");
4333 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
4337 if (pktin->type != SSH1_SMSG_SUCCESS
4338 && pktin->type != SSH1_SMSG_FAILURE) {
4339 bombout(("Protocol confusion"));
4341 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4342 logevent("Agent forwarding refused");
4344 logevent("Agent forwarding enabled");
4345 ssh->agentfwd_enabled = TRUE;
4346 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
4350 if (ssh->cfg.x11_forward) {
4351 char proto[20], data[64];
4352 logevent("Requesting X11 forwarding");
4353 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
4354 data, sizeof(data), ssh->cfg.x11_auth);
4355 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
4356 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
4357 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4358 PKT_STR, proto, PKT_STR, data,
4359 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
4362 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4363 PKT_STR, proto, PKT_STR, data, PKT_END);
4368 if (pktin->type != SSH1_SMSG_SUCCESS
4369 && pktin->type != SSH1_SMSG_FAILURE) {
4370 bombout(("Protocol confusion"));
4372 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4373 logevent("X11 forwarding refused");
4375 logevent("X11 forwarding enabled");
4376 ssh->X11_fwd_enabled = TRUE;
4377 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
4381 ssh_setup_portfwd(ssh, &ssh->cfg);
4382 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
4384 if (!ssh->cfg.nopty) {
4385 /* Unpick the terminal-speed string. */
4386 /* XXX perhaps we should allow no speeds to be sent. */
4387 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4388 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
4389 /* Send the pty request. */
4390 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
4391 PKT_STR, ssh->cfg.termtype,
4392 PKT_INT, ssh->term_height,
4393 PKT_INT, ssh->term_width,
4394 PKT_INT, 0, PKT_INT, 0, /* width,height in pixels */
4395 PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */
4396 PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */
4397 PKT_CHAR, 0, PKT_END);
4398 ssh->state = SSH_STATE_INTERMED;
4402 if (pktin->type != SSH1_SMSG_SUCCESS
4403 && pktin->type != SSH1_SMSG_FAILURE) {
4404 bombout(("Protocol confusion"));
4406 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4407 c_write_str(ssh, "Server refused to allocate pty\r\n");
4408 ssh->editing = ssh->echoing = 1;
4410 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
4411 ssh->ospeed, ssh->ispeed);
4413 ssh->editing = ssh->echoing = 1;
4416 if (ssh->cfg.compression) {
4417 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
4421 if (pktin->type != SSH1_SMSG_SUCCESS
4422 && pktin->type != SSH1_SMSG_FAILURE) {
4423 bombout(("Protocol confusion"));
4425 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4426 c_write_str(ssh, "Server refused to compress\r\n");
4428 logevent("Started compression");
4429 ssh->v1_compressing = TRUE;
4430 ssh->cs_comp_ctx = zlib_compress_init();
4431 logevent("Initialised zlib (RFC1950) compression");
4432 ssh->sc_comp_ctx = zlib_decompress_init();
4433 logevent("Initialised zlib (RFC1950) decompression");
4437 * Start the shell or command.
4439 * Special case: if the first-choice command is an SSH2
4440 * subsystem (hence not usable here) and the second choice
4441 * exists, we fall straight back to that.
4444 char *cmd = ssh->cfg.remote_cmd_ptr;
4446 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4447 cmd = ssh->cfg.remote_cmd_ptr2;
4448 ssh->fallback_cmd = TRUE;
4451 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
4453 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
4454 logevent("Started session");
4457 ssh->state = SSH_STATE_SESSION;
4458 if (ssh->size_needed)
4459 ssh_size(ssh, ssh->term_width, ssh->term_height);
4460 if (ssh->eof_needed)
4461 ssh_special(ssh, TS_EOF);
4464 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
4466 ssh->channels = newtree234(ssh_channelcmp);
4470 * By this point, most incoming packets are already being
4471 * handled by the dispatch table, and we need only pay
4472 * attention to the unusual ones.
4477 if (pktin->type == SSH1_SMSG_SUCCESS) {
4478 /* may be from EXEC_SHELL on some servers */
4479 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4480 /* may be from EXEC_SHELL on some servers
4481 * if no pty is available or in other odd cases. Ignore */
4483 bombout(("Strange packet received: type %d", pktin->type));
4488 int len = min(inlen, 512);
4489 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4490 PKT_INT, len, PKT_DATA, in, len,
4491 PKTT_OTHER, PKT_END);
4502 * Handle the top-level SSH2 protocol.
4504 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4509 ssh_pkt_getstring(pktin, &msg, &msglen);
4510 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
4515 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4517 /* log reason code in disconnect message */
4521 ssh_pkt_getstring(pktin, &msg, &msglen);
4522 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4525 void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
4527 /* Do nothing, because we're ignoring it! Duhh. */
4530 static void ssh1_protocol_setup(Ssh ssh)
4535 * Most messages are handled by the coroutines.
4537 for (i = 0; i < 256; i++)
4538 ssh->packet_dispatch[i] = NULL;
4541 * These special message types we install handlers for.
4543 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4544 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4545 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4548 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
4549 struct Packet *pktin)
4551 if (ssh->state == SSH_STATE_CLOSED)
4554 if (pktin && ssh->packet_dispatch[pktin->type]) {
4555 ssh->packet_dispatch[pktin->type](ssh, pktin);
4559 if (!ssh->protocol_initial_phase_done) {
4560 if (do_ssh1_login(ssh, in, inlen, pktin))
4561 ssh->protocol_initial_phase_done = TRUE;
4566 do_ssh1_connection(ssh, in, inlen, pktin);
4570 * Utility routine for decoding comma-separated strings in KEXINIT.
4572 static int in_commasep_string(char *needle, char *haystack, int haylen)
4575 if (!needle || !haystack) /* protect against null pointers */
4577 needlen = strlen(needle);
4580 * Is it at the start of the string?
4582 if (haylen >= needlen && /* haystack is long enough */
4583 !memcmp(needle, haystack, needlen) && /* initial match */
4584 (haylen == needlen || haystack[needlen] == ',')
4585 /* either , or EOS follows */
4589 * If not, search for the next comma and resume after that.
4590 * If no comma found, terminate.
4592 while (haylen > 0 && *haystack != ',')
4593 haylen--, haystack++;
4596 haylen--, haystack++; /* skip over comma itself */
4601 * SSH2 key creation method.
4603 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4604 unsigned char *sessid, char chr,
4605 unsigned char *keyspace)
4608 /* First 20 bytes. */
4610 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4612 SHA_Bytes(&s, H, 20);
4613 SHA_Bytes(&s, &chr, 1);
4614 SHA_Bytes(&s, sessid, 20);
4615 SHA_Final(&s, keyspace);
4616 /* Next 20 bytes. */
4618 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4620 SHA_Bytes(&s, H, 20);
4621 SHA_Bytes(&s, keyspace, 20);
4622 SHA_Final(&s, keyspace + 20);
4626 * Handle the SSH2 transport layer.
4628 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
4629 struct Packet *pktin)
4631 struct do_ssh2_transport_state {
4632 int nbits, pbits, warn;
4633 Bignum p, g, e, f, K;
4634 int kex_init_value, kex_reply_value;
4635 const struct ssh_mac **maclist;
4637 const struct ssh2_cipher *cscipher_tobe;
4638 const struct ssh2_cipher *sccipher_tobe;
4639 const struct ssh_mac *csmac_tobe;
4640 const struct ssh_mac *scmac_tobe;
4641 const struct ssh_compress *cscomp_tobe;
4642 const struct ssh_compress *sccomp_tobe;
4643 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4644 int hostkeylen, siglen;
4645 void *hkey; /* actual host key */
4646 unsigned char exchange_hash[20];
4647 int n_preferred_kex;
4648 const struct ssh_kex *preferred_kex[KEX_MAX];
4649 int n_preferred_ciphers;
4650 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4651 const struct ssh_compress *preferred_comp;
4653 struct Packet *pktout;
4655 crState(do_ssh2_transport_state);
4657 crBegin(ssh->do_ssh2_transport_crstate);
4659 s->cscipher_tobe = s->sccipher_tobe = NULL;
4660 s->csmac_tobe = s->scmac_tobe = NULL;
4661 s->cscomp_tobe = s->sccomp_tobe = NULL;
4668 * Set up the preferred key exchange. (NULL => warn below here)
4670 s->n_preferred_kex = 0;
4671 for (i = 0; i < KEX_MAX; i++) {
4672 switch (ssh->cfg.ssh_kexlist[i]) {
4674 s->preferred_kex[s->n_preferred_kex++] =
4675 &ssh_diffiehellman_gex;
4678 s->preferred_kex[s->n_preferred_kex++] =
4679 &ssh_diffiehellman_group14;
4682 s->preferred_kex[s->n_preferred_kex++] =
4683 &ssh_diffiehellman_group1;
4686 /* Flag for later. Don't bother if it's the last in
4688 if (i < KEX_MAX - 1) {
4689 s->preferred_kex[s->n_preferred_kex++] = NULL;
4699 * Set up the preferred ciphers. (NULL => warn below here)
4701 s->n_preferred_ciphers = 0;
4702 for (i = 0; i < CIPHER_MAX; i++) {
4703 switch (ssh->cfg.ssh_cipherlist[i]) {
4704 case CIPHER_BLOWFISH:
4705 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
4708 if (ssh->cfg.ssh2_des_cbc) {
4709 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
4713 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
4716 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
4719 /* Flag for later. Don't bother if it's the last in
4721 if (i < CIPHER_MAX - 1) {
4722 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
4730 * Set up preferred compression.
4732 if (ssh->cfg.compression)
4733 s->preferred_comp = &ssh_zlib;
4735 s->preferred_comp = &ssh_comp_none;
4738 * Be prepared to work around the buggy MAC problem.
4740 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4741 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
4743 s->maclist = macs, s->nmacs = lenof(macs);
4747 int i, j, commalist_started;
4750 * Enable queueing of outgoing auth- or connection-layer
4751 * packets while we are in the middle of a key exchange.
4753 ssh->queueing = TRUE;
4756 * Flag that KEX is in progress.
4758 ssh->kex_in_progress = TRUE;
4761 * Construct and send our key exchange packet.
4763 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
4764 for (i = 0; i < 16; i++)
4765 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
4766 /* List key exchange algorithms. */
4767 ssh2_pkt_addstring_start(s->pktout);
4768 commalist_started = 0;
4769 for (i = 0; i < s->n_preferred_kex; i++) {
4770 const struct ssh_kex *k = s->preferred_kex[i];
4771 if (!k) continue; /* warning flag */
4772 if (commalist_started)
4773 ssh2_pkt_addstring_str(s->pktout, ",");
4774 ssh2_pkt_addstring_str(s->pktout, s->preferred_kex[i]->name);
4775 commalist_started = 1;
4777 /* List server host key algorithms. */
4778 ssh2_pkt_addstring_start(s->pktout);
4779 for (i = 0; i < lenof(hostkey_algs); i++) {
4780 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
4781 if (i < lenof(hostkey_algs) - 1)
4782 ssh2_pkt_addstring_str(s->pktout, ",");
4784 /* List client->server encryption algorithms. */
4785 ssh2_pkt_addstring_start(s->pktout);
4786 commalist_started = 0;
4787 for (i = 0; i < s->n_preferred_ciphers; i++) {
4788 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4789 if (!c) continue; /* warning flag */
4790 for (j = 0; j < c->nciphers; j++) {
4791 if (commalist_started)
4792 ssh2_pkt_addstring_str(s->pktout, ",");
4793 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
4794 commalist_started = 1;
4797 /* List server->client encryption algorithms. */
4798 ssh2_pkt_addstring_start(s->pktout);
4799 commalist_started = 0;
4800 for (i = 0; i < s->n_preferred_ciphers; i++) {
4801 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4802 if (!c) continue; /* warning flag */
4803 for (j = 0; j < c->nciphers; j++) {
4804 if (commalist_started)
4805 ssh2_pkt_addstring_str(s->pktout, ",");
4806 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
4807 commalist_started = 1;
4810 /* List client->server MAC algorithms. */
4811 ssh2_pkt_addstring_start(s->pktout);
4812 for (i = 0; i < s->nmacs; i++) {
4813 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
4814 if (i < s->nmacs - 1)
4815 ssh2_pkt_addstring_str(s->pktout, ",");
4817 /* List server->client MAC algorithms. */
4818 ssh2_pkt_addstring_start(s->pktout);
4819 for (i = 0; i < s->nmacs; i++) {
4820 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
4821 if (i < s->nmacs - 1)
4822 ssh2_pkt_addstring_str(s->pktout, ",");
4824 /* List client->server compression algorithms. */
4825 ssh2_pkt_addstring_start(s->pktout);
4826 assert(lenof(compressions) > 1);
4827 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
4828 for (i = 0; i < lenof(compressions); i++) {
4829 const struct ssh_compress *c = compressions[i];
4830 if (c != s->preferred_comp) {
4831 ssh2_pkt_addstring_str(s->pktout, ",");
4832 ssh2_pkt_addstring_str(s->pktout, c->name);
4835 /* List server->client compression algorithms. */
4836 ssh2_pkt_addstring_start(s->pktout);
4837 assert(lenof(compressions) > 1);
4838 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
4839 for (i = 0; i < lenof(compressions); i++) {
4840 const struct ssh_compress *c = compressions[i];
4841 if (c != s->preferred_comp) {
4842 ssh2_pkt_addstring_str(s->pktout, ",");
4843 ssh2_pkt_addstring_str(s->pktout, c->name);
4846 /* List client->server languages. Empty list. */
4847 ssh2_pkt_addstring_start(s->pktout);
4848 /* List server->client languages. Empty list. */
4849 ssh2_pkt_addstring_start(s->pktout);
4850 /* First KEX packet does _not_ follow, because we're not that brave. */
4851 ssh2_pkt_addbool(s->pktout, FALSE);
4853 ssh2_pkt_adduint32(s->pktout, 0);
4856 ssh->exhash = ssh->exhashbase;
4857 sha_string(&ssh->exhash, s->pktout->data + 5, s->pktout->length - 5);
4859 ssh2_pkt_send_noqueue(ssh, s->pktout);
4863 if (pktin->length > 5)
4864 sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5);
4867 * Now examine the other side's KEXINIT to see what we're up
4874 if (pktin->type != SSH2_MSG_KEXINIT) {
4875 bombout(("expected key exchange packet from server"));
4879 ssh->hostkey = NULL;
4880 s->cscipher_tobe = NULL;
4881 s->sccipher_tobe = NULL;
4882 s->csmac_tobe = NULL;
4883 s->scmac_tobe = NULL;
4884 s->cscomp_tobe = NULL;
4885 s->sccomp_tobe = NULL;
4886 pktin->savedpos += 16; /* skip garbage cookie */
4887 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
4889 for (i = 0; i < s->n_preferred_kex; i++) {
4890 const struct ssh_kex *k = s->preferred_kex[i];
4893 } else if (in_commasep_string(k->name, str, len)) {
4898 askalg(ssh->frontend, "key-exchange algorithm",
4904 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
4905 str ? str : "(null)"));
4908 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
4909 for (i = 0; i < lenof(hostkey_algs); i++) {
4910 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
4911 ssh->hostkey = hostkey_algs[i];
4915 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
4917 for (i = 0; i < s->n_preferred_ciphers; i++) {
4918 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4922 for (j = 0; j < c->nciphers; j++) {
4923 if (in_commasep_string(c->list[j]->name, str, len)) {
4924 s->cscipher_tobe = c->list[j];
4929 if (s->cscipher_tobe) {
4931 askalg(ssh->frontend, "client-to-server cipher",
4932 s->cscipher_tobe->name);
4936 if (!s->cscipher_tobe) {
4937 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
4938 str ? str : "(null)"));
4942 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
4944 for (i = 0; i < s->n_preferred_ciphers; i++) {
4945 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4949 for (j = 0; j < c->nciphers; j++) {
4950 if (in_commasep_string(c->list[j]->name, str, len)) {
4951 s->sccipher_tobe = c->list[j];
4956 if (s->sccipher_tobe) {
4958 askalg(ssh->frontend, "server-to-client cipher",
4959 s->sccipher_tobe->name);
4963 if (!s->sccipher_tobe) {
4964 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
4965 str ? str : "(null)"));
4969 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
4970 for (i = 0; i < s->nmacs; i++) {
4971 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4972 s->csmac_tobe = s->maclist[i];
4976 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
4977 for (i = 0; i < s->nmacs; i++) {
4978 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4979 s->scmac_tobe = s->maclist[i];
4983 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
4984 for (i = 0; i < lenof(compressions) + 1; i++) {
4985 const struct ssh_compress *c =
4986 i == 0 ? s->preferred_comp : compressions[i - 1];
4987 if (in_commasep_string(c->name, str, len)) {
4992 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
4993 for (i = 0; i < lenof(compressions) + 1; i++) {
4994 const struct ssh_compress *c =
4995 i == 0 ? s->preferred_comp : compressions[i - 1];
4996 if (in_commasep_string(c->name, str, len)) {
5004 * Work out the number of bits of key we will need from the key
5005 * exchange. We start with the maximum key length of either
5011 csbits = s->cscipher_tobe->keylen;
5012 scbits = s->sccipher_tobe->keylen;
5013 s->nbits = (csbits > scbits ? csbits : scbits);
5015 /* The keys only have 160-bit entropy, since they're based on
5016 * a SHA-1 hash. So cap the key size at 160 bits. */
5021 * If we're doing Diffie-Hellman group exchange, start by
5022 * requesting a group.
5024 if (!ssh->kex->pdata) {
5025 logevent("Doing Diffie-Hellman group exchange");
5026 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
5028 * Work out how big a DH group we will need to allow that
5031 s->pbits = 512 << ((s->nbits - 1) / 64);
5032 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5033 ssh2_pkt_adduint32(s->pktout, s->pbits);
5034 ssh2_pkt_send_noqueue(ssh, s->pktout);
5037 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
5038 bombout(("expected key exchange group packet from server"));
5041 s->p = ssh2_pkt_getmp(pktin);
5042 s->g = ssh2_pkt_getmp(pktin);
5043 if (!s->p || !s->g) {
5044 bombout(("unable to read mp-ints from incoming group packet"));
5047 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
5048 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5049 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
5051 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP;
5052 ssh->kex_ctx = dh_setup_group(ssh->kex);
5053 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5054 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
5055 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5056 ssh->kex->groupname);
5059 logevent("Doing Diffie-Hellman key exchange");
5061 * Now generate and send e for Diffie-Hellman.
5063 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
5064 s->pktout = ssh2_pkt_init(s->kex_init_value);
5065 ssh2_pkt_addmp(s->pktout, s->e);
5066 ssh2_pkt_send_noqueue(ssh, s->pktout);
5069 if (pktin->type != s->kex_reply_value) {
5070 bombout(("expected key exchange reply packet from server"));
5073 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5074 s->f = ssh2_pkt_getmp(pktin);
5076 bombout(("unable to parse key exchange reply packet"));
5079 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
5081 s->K = dh_find_K(ssh->kex_ctx, s->f);
5083 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
5084 if (ssh->kex == &ssh_diffiehellman_gex) {
5085 sha_uint32(&ssh->exhash, s->pbits);
5086 sha_mpint(&ssh->exhash, s->p);
5087 sha_mpint(&ssh->exhash, s->g);
5089 sha_mpint(&ssh->exhash, s->e);
5090 sha_mpint(&ssh->exhash, s->f);
5091 sha_mpint(&ssh->exhash, s->K);
5092 SHA_Final(&ssh->exhash, s->exchange_hash);
5094 dh_cleanup(ssh->kex_ctx);
5095 ssh->kex_ctx = NULL;
5098 debug(("Exchange hash is:\n"));
5099 dmemdump(s->exchange_hash, 20);
5102 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5104 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
5105 (char *)s->exchange_hash, 20)) {
5106 bombout(("Server's host key did not match the signature supplied"));
5111 * Authenticate remote host: verify host key. (We've already
5112 * checked the signature of the exchange hash.)
5114 s->keystr = ssh->hostkey->fmtkey(s->hkey);
5115 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
5116 verify_ssh_host_key(ssh->frontend,
5117 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
5118 s->keystr, s->fingerprint);
5119 if (s->first_kex) { /* don't bother logging this in rekeys */
5120 logevent("Host key fingerprint is:");
5121 logevent(s->fingerprint);
5123 sfree(s->fingerprint);
5125 ssh->hostkey->freekey(s->hkey);
5128 * The exchange hash from the very first key exchange is also
5129 * the session id, used in session key construction and
5133 memcpy(ssh->v2_session_id, s->exchange_hash,
5134 sizeof(s->exchange_hash));
5137 * Send SSH2_MSG_NEWKEYS.
5139 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
5140 ssh2_pkt_send_noqueue(ssh, s->pktout);
5141 ssh->outgoing_data_size = 0; /* start counting from here */
5144 * We've sent client NEWKEYS, so create and initialise
5145 * client-to-server session keys.
5147 if (ssh->cs_cipher_ctx)
5148 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
5149 ssh->cscipher = s->cscipher_tobe;
5150 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
5152 if (ssh->cs_mac_ctx)
5153 ssh->csmac->free_context(ssh->cs_mac_ctx);
5154 ssh->csmac = s->csmac_tobe;
5155 ssh->cs_mac_ctx = ssh->csmac->make_context();
5157 if (ssh->cs_comp_ctx)
5158 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
5159 ssh->cscomp = s->cscomp_tobe;
5160 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
5163 * Set IVs on client-to-server keys. Here we use the exchange
5164 * hash from the _first_ key exchange.
5167 unsigned char keyspace[40];
5168 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
5169 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
5170 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
5171 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
5172 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
5173 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
5176 logeventf(ssh, "Initialised %.200s client->server encryption",
5177 ssh->cscipher->text_name);
5178 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
5179 ssh->csmac->text_name);
5180 if (ssh->cscomp->text_name)
5181 logeventf(ssh, "Initialised %s compression",
5182 ssh->cscomp->text_name);
5185 * Now our end of the key exchange is complete, we can send all
5186 * our queued higher-layer packets.
5188 ssh->queueing = FALSE;
5189 ssh2_pkt_queuesend(ssh);
5192 * Expect SSH2_MSG_NEWKEYS from server.
5195 if (pktin->type != SSH2_MSG_NEWKEYS) {
5196 bombout(("expected new-keys packet from server"));
5199 ssh->incoming_data_size = 0; /* start counting from here */
5202 * We've seen server NEWKEYS, so create and initialise
5203 * server-to-client session keys.
5205 if (ssh->sc_cipher_ctx)
5206 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
5207 ssh->sccipher = s->sccipher_tobe;
5208 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
5210 if (ssh->sc_mac_ctx)
5211 ssh->scmac->free_context(ssh->sc_mac_ctx);
5212 ssh->scmac = s->scmac_tobe;
5213 ssh->sc_mac_ctx = ssh->scmac->make_context();
5215 if (ssh->sc_comp_ctx)
5216 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
5217 ssh->sccomp = s->sccomp_tobe;
5218 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
5221 * Set IVs on server-to-client keys. Here we use the exchange
5222 * hash from the _first_ key exchange.
5225 unsigned char keyspace[40];
5226 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
5227 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
5228 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
5229 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
5230 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
5231 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
5233 logeventf(ssh, "Initialised %.200s server->client encryption",
5234 ssh->sccipher->text_name);
5235 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
5236 ssh->scmac->text_name);
5237 if (ssh->sccomp->text_name)
5238 logeventf(ssh, "Initialised %s decompression",
5239 ssh->sccomp->text_name);
5242 * Free key exchange data.
5246 if (ssh->kex == &ssh_diffiehellman_gex) {
5252 * Key exchange is over. Schedule a timer for our next rekey.
5254 ssh->kex_in_progress = FALSE;
5255 ssh->last_rekey = GETTICKCOUNT();
5256 if (ssh->cfg.ssh_rekey_time != 0)
5257 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5261 * If this is the first key exchange phase, we must pass the
5262 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
5263 * wants to see it but because it will need time to initialise
5264 * itself before it sees an actual packet. In subsequent key
5265 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
5266 * it would only confuse the layer above.
5268 if (!s->first_kex) {
5274 * Now we're encrypting. Begin returning 1 to the protocol main
5275 * function so that other things can run on top of the
5276 * transport. If we ever see a KEXINIT, we must go back to the
5279 * We _also_ go back to the start if we see pktin==NULL and
5280 * inlen==-1, because this is a special signal meaning
5281 * `initiate client-driven rekey', and `in' contains a message
5282 * giving the reason for the rekey.
5284 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
5285 (!pktin && inlen == -1))) {
5289 logevent("Server initiated key re-exchange");
5291 logevent((char *)in);
5293 goto begin_key_exchange;
5299 * Add data to an SSH2 channel output buffer.
5301 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
5304 bufchain_add(&c->v.v2.outbuffer, buf, len);
5308 * Attempt to send data on an SSH2 channel.
5310 static int ssh2_try_send(struct ssh_channel *c)
5313 struct Packet *pktout;
5315 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
5318 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
5319 if ((unsigned)len > c->v.v2.remwindow)
5320 len = c->v.v2.remwindow;
5321 if ((unsigned)len > c->v.v2.remmaxpkt)
5322 len = c->v.v2.remmaxpkt;
5323 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
5324 ssh2_pkt_adduint32(pktout, c->remoteid);
5325 dont_log_data(ssh, pktout, PKTLOG_OMIT);
5326 ssh2_pkt_addstring_start(pktout);
5327 ssh2_pkt_addstring_data(pktout, data, len);
5328 end_log_omission(ssh, pktout);
5329 ssh2_pkt_send(ssh, pktout);
5330 bufchain_consume(&c->v.v2.outbuffer, len);
5331 c->v.v2.remwindow -= len;
5335 * After having sent as much data as we can, return the amount
5338 return bufchain_size(&c->v.v2.outbuffer);
5342 * Potentially enlarge the window on an SSH2 channel.
5344 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
5349 * Never send WINDOW_ADJUST for a channel that the remote side
5350 * already thinks it's closed; there's no point, since it won't
5351 * be sending any more data anyway.
5356 if (newwin > c->v.v2.locwindow) {
5357 struct Packet *pktout;
5359 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5360 ssh2_pkt_adduint32(pktout, c->remoteid);
5361 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
5362 ssh2_pkt_send(ssh, pktout);
5363 c->v.v2.locwindow = newwin;
5367 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
5369 unsigned i = ssh_pkt_getuint32(pktin);
5370 struct ssh_channel *c;
5371 c = find234(ssh->channels, &i, ssh_channelfind);
5372 if (c && !c->closes)
5373 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
5376 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
5379 unsigned int length;
5380 unsigned i = ssh_pkt_getuint32(pktin);
5381 struct ssh_channel *c;
5382 c = find234(ssh->channels, &i, ssh_channelfind);
5384 return; /* nonexistent channel */
5385 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5386 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
5387 return; /* extended but not stderr */
5388 ssh_pkt_getstring(pktin, &data, &length);
5391 c->v.v2.locwindow -= length;
5393 case CHAN_MAINSESSION:
5395 from_backend(ssh->frontend, pktin->type ==
5396 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5400 bufsize = x11_send(c->u.x11.s, data, length);
5403 bufsize = pfd_send(c->u.pfd.s, data, length);
5406 while (length > 0) {
5407 if (c->u.a.lensofar < 4) {
5408 unsigned int l = min(4 - c->u.a.lensofar, length);
5409 memcpy(c->u.a.msglen + c->u.a.lensofar,
5413 c->u.a.lensofar += l;
5415 if (c->u.a.lensofar == 4) {
5417 4 + GET_32BIT(c->u.a.msglen);
5418 c->u.a.message = snewn(c->u.a.totallen,
5420 memcpy(c->u.a.message, c->u.a.msglen, 4);
5422 if (c->u.a.lensofar >= 4 && length > 0) {
5424 min(c->u.a.totallen - c->u.a.lensofar,
5426 memcpy(c->u.a.message + c->u.a.lensofar,
5430 c->u.a.lensofar += l;
5432 if (c->u.a.lensofar == c->u.a.totallen) {
5435 if (agent_query(c->u.a.message,
5438 ssh_agentf_callback, c))
5439 ssh_agentf_callback(c, reply, replylen);
5440 sfree(c->u.a.message);
5441 c->u.a.lensofar = 0;
5448 * If we are not buffering too much data,
5449 * enlarge the window again at the remote side.
5451 if (bufsize < OUR_V2_WINSIZE)
5452 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5456 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
5458 unsigned i = ssh_pkt_getuint32(pktin);
5459 struct ssh_channel *c;
5461 c = find234(ssh->channels, &i, ssh_channelfind);
5463 return; /* nonexistent channel */
5465 if (c->type == CHAN_X11) {
5467 * Remote EOF on an X11 channel means we should
5468 * wrap up and close the channel ourselves.
5470 x11_close(c->u.x11.s);
5472 } else if (c->type == CHAN_AGENT) {
5474 } else if (c->type == CHAN_SOCKDATA) {
5475 pfd_close(c->u.pfd.s);
5480 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
5482 unsigned i = ssh_pkt_getuint32(pktin);
5483 struct ssh_channel *c;
5484 struct Packet *pktout;
5486 c = find234(ssh->channels, &i, ssh_channelfind);
5487 if (!c || ((int)c->remoteid) == -1) {
5488 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5489 c ? "half-open" : "nonexistent", i));
5492 /* Do pre-close processing on the channel. */
5494 case CHAN_MAINSESSION:
5495 ssh->mainchan = NULL;
5496 update_specials_menu(ssh->frontend);
5499 if (c->u.x11.s != NULL)
5500 x11_close(c->u.x11.s);
5507 if (c->u.pfd.s != NULL)
5508 pfd_close(c->u.pfd.s);
5512 if (c->closes == 0) {
5513 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5514 ssh2_pkt_adduint32(pktout, c->remoteid);
5515 ssh2_pkt_send(ssh, pktout);
5517 del234(ssh->channels, c);
5518 bufchain_clear(&c->v.v2.outbuffer);
5522 * See if that was the last channel left open.
5523 * (This is only our termination condition if we're
5524 * not running in -N mode.)
5526 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
5527 logevent("All channels closed. Disconnecting");
5530 * We used to send SSH_MSG_DISCONNECT here,
5531 * because I'd believed that _every_ conforming
5532 * SSH2 connection had to end with a disconnect
5533 * being sent by at least one side; apparently
5534 * I was wrong and it's perfectly OK to
5535 * unceremoniously slam the connection shut
5536 * when you're done, and indeed OpenSSH feels
5537 * this is more polite than sending a
5538 * DISCONNECT. So now we don't.
5540 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5541 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
5542 ssh2_pkt_addstring(s->pktout, "All open channels closed");
5543 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
5544 ssh2_pkt_send_noqueue(ssh, s->pktout);
5546 ssh_closing((Plug)ssh, NULL, 0, 0);
5550 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5552 unsigned i = ssh_pkt_getuint32(pktin);
5553 struct ssh_channel *c;
5554 struct Packet *pktout;
5556 c = find234(ssh->channels, &i, ssh_channelfind);
5558 return; /* nonexistent channel */
5559 if (c->type != CHAN_SOCKDATA_DORMANT)
5560 return; /* dunno why they're confirming this */
5561 c->remoteid = ssh_pkt_getuint32(pktin);
5562 c->type = CHAN_SOCKDATA;
5563 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
5564 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
5566 pfd_confirm(c->u.pfd.s);
5569 * We have a pending close on this channel,
5570 * which we decided on before the server acked
5571 * the channel open. So now we know the
5572 * remoteid, we can close it again.
5574 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5575 ssh2_pkt_adduint32(pktout, c->remoteid);
5576 ssh2_pkt_send(ssh, pktout);
5580 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5582 static const char *const reasons[] = {
5583 "<unknown reason code>",
5584 "Administratively prohibited",
5586 "Unknown channel type",
5587 "Resource shortage",
5589 unsigned i = ssh_pkt_getuint32(pktin);
5590 unsigned reason_code;
5591 char *reason_string;
5594 struct ssh_channel *c;
5595 c = find234(ssh->channels, &i, ssh_channelfind);
5597 return; /* nonexistent channel */
5598 if (c->type != CHAN_SOCKDATA_DORMANT)
5599 return; /* dunno why they're failing this */
5601 reason_code = ssh_pkt_getuint32(pktin);
5602 if (reason_code >= lenof(reasons))
5603 reason_code = 0; /* ensure reasons[reason_code] in range */
5604 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
5605 message = dupprintf("Forwarded connection refused by"
5606 " server: %s [%.*s]", reasons[reason_code],
5607 reason_length, reason_string);
5611 pfd_close(c->u.pfd.s);
5613 del234(ssh->channels, c);
5617 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
5621 int typelen, want_reply;
5622 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
5623 struct ssh_channel *c;
5624 struct Packet *pktout;
5626 localid = ssh_pkt_getuint32(pktin);
5627 ssh_pkt_getstring(pktin, &type, &typelen);
5628 want_reply = ssh2_pkt_getbool(pktin);
5631 * First, check that the channel exists. Otherwise,
5632 * we can instantly disconnect with a rude message.
5634 c = find234(ssh->channels, &localid, ssh_channelfind);
5637 sprintf(buf, "Received channel request for nonexistent"
5638 " channel %d", localid);
5640 pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5641 ssh2_pkt_adduint32(pktout, SSH2_DISCONNECT_BY_APPLICATION);
5642 ssh2_pkt_addstring(pktout, buf);
5643 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5644 ssh2_pkt_send_noqueue(ssh, pktout);
5645 connection_fatal(ssh->frontend, "%s", buf);
5646 ssh_closing((Plug)ssh, NULL, 0, 0);
5651 * Having got the channel number, we now look at
5652 * the request type string to see if it's something
5655 if (c == ssh->mainchan) {
5657 * We recognise "exit-status" and "exit-signal" on
5658 * the primary channel.
5660 if (typelen == 11 &&
5661 !memcmp(type, "exit-status", 11)) {
5663 ssh->exitcode = ssh_pkt_getuint32(pktin);
5664 logeventf(ssh, "Server sent command exit status %d",
5666 reply = SSH2_MSG_CHANNEL_SUCCESS;
5668 } else if (typelen == 11 &&
5669 !memcmp(type, "exit-signal", 11)) {
5671 int is_plausible = TRUE, is_int = FALSE;
5672 char *fmt_sig = "", *fmt_msg = "";
5674 int msglen = 0, core = FALSE;
5675 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
5676 * provide an `int' for the signal, despite its
5677 * having been a `string' in the drafts since at
5678 * least 2001. (Fixed in session.c 1.147.) Try to
5679 * infer which we can safely parse it as. */
5681 unsigned char *p = pktin->body +
5683 long len = pktin->length - pktin->savedpos;
5684 unsigned long num = GET_32BIT(p); /* what is it? */
5685 /* If it's 0, it hardly matters; assume string */
5689 int maybe_int = FALSE, maybe_str = FALSE;
5690 #define CHECK_HYPOTHESIS(offset, result) \
5693 if (q >= 0 && q+4 <= len) { \
5694 q = q + 4 + GET_32BIT(p+q); \
5695 if (q >= 0 && q+4 <= len && \
5696 (q = q + 4 + GET_32BIT(p+q)) && q == len) \
5700 CHECK_HYPOTHESIS(4+1, maybe_int);
5701 CHECK_HYPOTHESIS(4+num+1, maybe_str);
5702 #undef CHECK_HYPOTHESIS
5703 if (maybe_int && !maybe_str)
5705 else if (!maybe_int && maybe_str)
5708 /* Crikey. Either or neither. Panic. */
5709 is_plausible = FALSE;
5714 /* Old non-standard OpenSSH. */
5715 int signum = ssh_pkt_getuint32(pktin);
5716 fmt_sig = dupprintf(" %d", signum);
5718 /* As per the drafts. */
5721 ssh_pkt_getstring(pktin, &sig, &siglen);
5722 /* Signal name isn't supposed to be blank, but
5723 * let's cope gracefully if it is. */
5725 fmt_sig = dupprintf(" \"%.*s\"",
5729 core = ssh2_pkt_getbool(pktin);
5730 ssh_pkt_getstring(pktin, &msg, &msglen);
5732 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
5734 /* ignore lang tag */
5735 } /* else don't attempt to parse */
5736 logeventf(ssh, "Server exited on signal%s%s%s",
5737 fmt_sig, core ? " (core dumped)" : "",
5739 if (*fmt_sig) sfree(fmt_sig);
5740 if (*fmt_msg) sfree(fmt_msg);
5741 reply = SSH2_MSG_CHANNEL_SUCCESS;
5746 * This is a channel request we don't know
5747 * about, so we now either ignore the request
5748 * or respond with CHANNEL_FAILURE, depending
5751 reply = SSH2_MSG_CHANNEL_FAILURE;
5754 pktout = ssh2_pkt_init(reply);
5755 ssh2_pkt_adduint32(pktout, c->remoteid);
5756 ssh2_pkt_send(ssh, pktout);
5760 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
5763 int typelen, want_reply;
5764 struct Packet *pktout;
5766 ssh_pkt_getstring(pktin, &type, &typelen);
5767 want_reply = ssh2_pkt_getbool(pktin);
5770 * We currently don't support any global requests
5771 * at all, so we either ignore the request or
5772 * respond with REQUEST_FAILURE, depending on
5776 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
5777 ssh2_pkt_send(ssh, pktout);
5781 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
5789 struct ssh_channel *c;
5790 unsigned remid, winsize, pktsize;
5791 struct Packet *pktout;
5793 ssh_pkt_getstring(pktin, &type, &typelen);
5794 c = snew(struct ssh_channel);
5797 remid = ssh_pkt_getuint32(pktin);
5798 winsize = ssh_pkt_getuint32(pktin);
5799 pktsize = ssh_pkt_getuint32(pktin);
5801 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5804 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5805 addrstr = snewn(peeraddrlen+1, char);
5806 memcpy(addrstr, peeraddr, peeraddrlen);
5807 addrstr[peeraddrlen] = '\0';
5808 peerport = ssh_pkt_getuint32(pktin);
5810 logeventf(ssh, "Received X11 connect request from %s:%d",
5813 if (!ssh->X11_fwd_enabled)
5814 error = "X11 forwarding is not enabled";
5815 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
5816 ssh->x11auth, addrstr, peerport,
5817 &ssh->cfg) != NULL) {
5818 error = "Unable to open an X11 connection";
5820 logevent("Opening X11 forward connection succeeded");
5825 } else if (typelen == 15 &&
5826 !memcmp(type, "forwarded-tcpip", 15)) {
5827 struct ssh_rportfwd pf, *realpf;
5830 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
5831 pf.sport = ssh_pkt_getuint32(pktin);
5832 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5833 peerport = ssh_pkt_getuint32(pktin);
5834 realpf = find234(ssh->rportfwds, &pf, NULL);
5835 logeventf(ssh, "Received remote port %d open request "
5836 "from %s:%d", pf.sport, peeraddr, peerport);
5837 if (realpf == NULL) {
5838 error = "Remote port is not recognised";
5840 const char *e = pfd_newconnect(&c->u.pfd.s,
5844 realpf->pfrec->addressfamily);
5845 logeventf(ssh, "Attempting to forward remote port to "
5846 "%s:%d", realpf->dhost, realpf->dport);
5848 logeventf(ssh, "Port open failed: %s", e);
5849 error = "Port open failed";
5851 logevent("Forwarded port opened successfully");
5852 c->type = CHAN_SOCKDATA;
5855 } else if (typelen == 22 &&
5856 !memcmp(type, "auth-agent@openssh.com", 3)) {
5857 if (!ssh->agentfwd_enabled)
5858 error = "Agent forwarding is not enabled";
5860 c->type = CHAN_AGENT; /* identify channel type */
5861 c->u.a.lensofar = 0;
5864 error = "Unsupported channel type requested";
5867 c->remoteid = remid;
5869 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
5870 ssh2_pkt_adduint32(pktout, c->remoteid);
5871 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
5872 ssh2_pkt_addstring(pktout, error);
5873 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5874 ssh2_pkt_send(ssh, pktout);
5875 logeventf(ssh, "Rejected channel open: %s", error);
5878 c->localid = alloc_channel_id(ssh);
5880 c->v.v2.locwindow = OUR_V2_WINSIZE;
5881 c->v.v2.remwindow = winsize;
5882 c->v.v2.remmaxpkt = pktsize;
5883 bufchain_init(&c->v.v2.outbuffer);
5884 add234(ssh->channels, c);
5885 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5886 ssh2_pkt_adduint32(pktout, c->remoteid);
5887 ssh2_pkt_adduint32(pktout, c->localid);
5888 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
5889 ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
5890 ssh2_pkt_send(ssh, pktout);
5895 * Handle the SSH2 userauth and connection layers.
5897 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
5898 struct Packet *pktin)
5900 struct do_ssh2_authconn_state {
5902 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
5904 AUTH_KEYBOARD_INTERACTIVE
5908 AUTH_TYPE_PUBLICKEY,
5909 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
5910 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
5912 AUTH_TYPE_KEYBOARD_INTERACTIVE,
5913 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
5915 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
5916 int tried_pubkey_config, tried_agent, tried_keyb_inter;
5917 int kbd_inter_running;
5919 int num_prompts, curr_prompt, echo;
5924 void *publickey_blob;
5925 int publickey_bloblen;
5926 unsigned char request[5], *response, *p;
5930 char *pkblob, *alg, *commentp;
5931 int pklen, alglen, commentlen;
5932 int siglen, retlen, len;
5933 char *q, *agentreq, *ret;
5935 int num_env, env_left, env_ok;
5936 struct Packet *pktout;
5938 crState(do_ssh2_authconn_state);
5940 crBegin(ssh->do_ssh2_authconn_crstate);
5943 * Request userauth protocol, and await a response to it.
5945 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
5946 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
5947 ssh2_pkt_send(ssh, s->pktout);
5948 crWaitUntilV(pktin);
5949 if (pktin->type != SSH2_MSG_SERVICE_ACCEPT) {
5950 bombout(("Server refused user authentication protocol"));
5955 * We repeat this whole loop, including the username prompt,
5956 * until we manage a successful authentication. If the user
5957 * types the wrong _password_, they can be sent back to the
5958 * beginning to try another username, if this is configured on.
5959 * (If they specify a username in the config, they are never
5960 * asked, even if they do give a wrong password.)
5962 * I think this best serves the needs of
5964 * - the people who have no configuration, no keys, and just
5965 * want to try repeated (username,password) pairs until they
5966 * type both correctly
5968 * - people who have keys and configuration but occasionally
5969 * need to fall back to passwords
5971 * - people with a key held in Pageant, who might not have
5972 * logged in to a particular machine before; so they want to
5973 * type a username, and then _either_ their key will be
5974 * accepted, _or_ they will type a password. If they mistype
5975 * the username they will want to be able to get back and
5978 s->username[0] = '\0';
5979 s->got_username = FALSE;
5984 if (s->got_username && !ssh->cfg.change_username) {
5986 * We got a username last time round this loop, and
5987 * with change_username turned off we don't try to get
5990 } else if (!*ssh->cfg.username) {
5991 if (ssh_get_line && !ssh_getline_pw_only) {
5992 if (!ssh_get_line("login as: ",
5993 s->username, sizeof(s->username), FALSE)) {
5995 * get_line failed to get a username.
5998 logevent("No username provided. Abandoning session.");
5999 ssh_closing((Plug)ssh, NULL, 0, 0);
6003 int ret; /* need not be saved across crReturn */
6004 c_write_str(ssh, "login as: ");
6006 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
6008 crWaitUntilV(!pktin);
6009 ret = process_userpass_input(ssh, in, inlen);
6013 c_write_str(ssh, "\r\n");
6015 s->username[strcspn(s->username, "\n\r")] = '\0';
6018 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
6019 s->username[sizeof(s->username)-1] = '\0';
6020 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
6021 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
6022 c_write_str(ssh, stuff);
6026 s->got_username = TRUE;
6029 * Send an authentication request using method "none": (a)
6030 * just in case it succeeds, and (b) so that we know what
6031 * authentication methods we can usefully try next.
6033 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6035 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6036 ssh2_pkt_addstring(s->pktout, s->username);
6037 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
6038 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6039 ssh2_pkt_send(ssh, s->pktout);
6040 s->type = AUTH_TYPE_NONE;
6042 s->we_are_in = FALSE;
6044 s->tried_pubkey_config = FALSE;
6045 s->tried_agent = FALSE;
6046 s->tried_keyb_inter = FALSE;
6047 s->kbd_inter_running = FALSE;
6048 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
6049 if (!filename_is_null(ssh->cfg.keyfile)) {
6051 logeventf(ssh, "Reading private key file \"%.150s\"",
6052 filename_to_str(&ssh->cfg.keyfile));
6053 keytype = key_type(&ssh->cfg.keyfile);
6054 if (keytype == SSH_KEYTYPE_SSH2) {
6056 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
6057 &s->publickey_bloblen, NULL);
6060 logeventf(ssh, "Unable to use this key file (%s)",
6061 key_type_to_str(keytype));
6062 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6064 filename_to_str(&ssh->cfg.keyfile),
6065 key_type_to_str(keytype));
6066 c_write_str(ssh, msgbuf);
6068 s->publickey_blob = NULL;
6071 s->publickey_blob = NULL;
6075 * Wait for the result of the last authentication request.
6078 crWaitUntilV(pktin);
6079 while (pktin->type == SSH2_MSG_USERAUTH_BANNER) {
6083 * Don't show the banner if we're operating in
6084 * non-verbose non-interactive mode. (It's probably
6085 * a script, which means nobody will read the
6086 * banner _anyway_, and moreover the printing of
6087 * the banner will screw up processing on the
6088 * output of (say) plink.)
6090 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
6091 ssh_pkt_getstring(pktin, &banner, &size);
6093 c_write_untrusted(ssh, banner, size);
6095 crWaitUntilV(pktin);
6097 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
6098 logevent("Access granted");
6099 s->we_are_in = TRUE;
6103 if (s->kbd_inter_running &&
6104 pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
6106 * This is either a further set-of-prompts packet
6107 * in keyboard-interactive authentication, or it's
6108 * the same one and we came back here with `gotit'
6109 * set. In the former case, we must reset the
6110 * curr_prompt variable.
6114 } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
6115 bombout(("Strange packet received during authentication: type %d",
6123 * OK, we're now sitting on a USERAUTH_FAILURE message, so
6124 * we can look at the string in it and know what we can
6125 * helpfully try next.
6127 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
6130 ssh_pkt_getstring(pktin, &methods, &methlen);
6131 s->kbd_inter_running = FALSE;
6132 if (!ssh2_pkt_getbool(pktin)) {
6134 * We have received an unequivocal Access
6135 * Denied. This can translate to a variety of
6138 * - if we'd just tried "none" authentication,
6139 * it's not worth printing anything at all
6141 * - if we'd just tried a public key _offer_,
6142 * the message should be "Server refused our
6143 * key" (or no message at all if the key
6144 * came from Pageant)
6146 * - if we'd just tried anything else, the
6147 * message really should be "Access denied".
6149 * Additionally, if we'd just tried password
6150 * authentication, we should break out of this
6151 * whole loop so as to go back to the username
6152 * prompt (iff we're configured to allow
6153 * username change attempts).
6155 if (s->type == AUTH_TYPE_NONE) {
6157 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
6158 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
6159 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
6160 c_write_str(ssh, "Server refused our key\r\n");
6161 logevent("Server refused public key");
6162 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
6163 /* server declined keyboard-interactive; ignore */
6165 c_write_str(ssh, "Access denied\r\n");
6166 logevent("Access denied");
6167 if (s->type == AUTH_TYPE_PASSWORD &&
6168 ssh->cfg.change_username) {
6169 /* XXX perhaps we should allow
6170 * keyboard-interactive to do this too? */
6171 s->we_are_in = FALSE;
6176 c_write_str(ssh, "Further authentication required\r\n");
6177 logevent("Further authentication required");
6181 in_commasep_string("publickey", methods, methlen);
6183 in_commasep_string("password", methods, methlen);
6184 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
6185 in_commasep_string("keyboard-interactive", methods, methlen);
6189 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6193 * Most password/passphrase prompts will be
6194 * non-echoing, so we set this to 0 by default.
6195 * Exception is that some keyboard-interactive prompts
6196 * can be echoing, in which case we'll set this to 1.
6200 if (!s->method && s->can_pubkey &&
6201 agent_exists() && !s->tried_agent) {
6203 * Attempt public-key authentication using Pageant.
6208 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6209 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6211 s->tried_agent = TRUE;
6213 logevent("Pageant is running. Requesting keys.");
6215 /* Request the keys held by the agent. */
6216 PUT_32BIT(s->request, 1);
6217 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
6218 if (!agent_query(s->request, 5, &r, &s->responselen,
6219 ssh_agent_callback, ssh)) {
6223 bombout(("Unexpected data from server while"
6224 " waiting for agent response"));
6227 } while (pktin || inlen > 0);
6228 r = ssh->agent_response;
6229 s->responselen = ssh->agent_response_len;
6231 s->response = (unsigned char *) r;
6232 if (s->response && s->responselen >= 5 &&
6233 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
6234 s->p = s->response + 5;
6235 s->nkeys = GET_32BIT(s->p);
6239 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
6242 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
6247 sprintf(buf, "Trying Pageant key #%d", s->keyi);
6250 s->pklen = GET_32BIT(s->p);
6252 if (s->publickey_blob &&
6253 s->pklen == s->publickey_bloblen &&
6254 !memcmp(s->p, s->publickey_blob,
6255 s->publickey_bloblen)) {
6256 logevent("This key matches configured key file");
6257 s->tried_pubkey_config = 1;
6259 s->pkblob = (char *)s->p;
6261 s->alglen = GET_32BIT(s->pkblob);
6262 s->alg = s->pkblob + 4;
6263 s->commentlen = GET_32BIT(s->p);
6265 s->commentp = (char *)s->p;
6266 s->p += s->commentlen;
6267 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6268 ssh2_pkt_addstring(s->pktout, s->username);
6269 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6270 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6271 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6272 ssh2_pkt_addstring_start(s->pktout);
6273 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6274 ssh2_pkt_addstring_start(s->pktout);
6275 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6276 ssh2_pkt_send(ssh, s->pktout);
6278 crWaitUntilV(pktin);
6279 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6280 logevent("Key refused");
6284 if (flags & FLAG_VERBOSE) {
6285 c_write_str(ssh, "Authenticating with "
6287 c_write(ssh, s->commentp, s->commentlen);
6288 c_write_str(ssh, "\" from agent\r\n");
6292 * Server is willing to accept the key.
6293 * Construct a SIGN_REQUEST.
6295 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6296 ssh2_pkt_addstring(s->pktout, s->username);
6297 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6298 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6299 ssh2_pkt_addbool(s->pktout, TRUE);
6300 ssh2_pkt_addstring_start(s->pktout);
6301 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6302 ssh2_pkt_addstring_start(s->pktout);
6303 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6305 s->siglen = s->pktout->length - 5 + 4 + 20;
6306 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6308 s->len = 1; /* message type */
6309 s->len += 4 + s->pklen; /* key blob */
6310 s->len += 4 + s->siglen; /* data to sign */
6311 s->len += 4; /* flags */
6312 s->agentreq = snewn(4 + s->len, char);
6313 PUT_32BIT(s->agentreq, s->len);
6314 s->q = s->agentreq + 4;
6315 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
6316 PUT_32BIT(s->q, s->pklen);
6318 memcpy(s->q, s->pkblob, s->pklen);
6320 PUT_32BIT(s->q, s->siglen);
6322 /* Now the data to be signed... */
6323 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6324 PUT_32BIT(s->q, 20);
6327 memcpy(s->q, ssh->v2_session_id, 20);
6329 memcpy(s->q, s->pktout->data + 5,
6330 s->pktout->length - 5);
6331 s->q += s->pktout->length - 5;
6332 /* And finally the (zero) flags word. */
6334 if (!agent_query(s->agentreq, s->len + 4,
6336 ssh_agent_callback, ssh)) {
6340 bombout(("Unexpected data from server"
6341 " while waiting for agent"
6345 } while (pktin || inlen > 0);
6346 vret = ssh->agent_response;
6347 s->retlen = ssh->agent_response_len;
6352 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
6353 logevent("Sending Pageant's response");
6354 ssh2_add_sigblob(ssh, s->pktout,
6355 s->pkblob, s->pklen,
6357 GET_32BIT(s->ret + 5));
6358 ssh2_pkt_send(ssh, s->pktout);
6363 ("Pageant failed to answer challenge");
6374 if (!s->method && s->can_pubkey && s->publickey_blob
6375 && !s->tried_pubkey_config) {
6376 unsigned char *pub_blob;
6377 char *algorithm, *comment;
6380 s->tried_pubkey_config = TRUE;
6382 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6383 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6386 * Try the public key supplied in the configuration.
6388 * First, offer the public blob to see if the server is
6389 * willing to accept it.
6392 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
6397 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6398 ssh2_pkt_addstring(s->pktout, s->username);
6399 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6400 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6401 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6402 ssh2_pkt_addstring(s->pktout, algorithm);
6403 ssh2_pkt_addstring_start(s->pktout);
6404 ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob,
6406 ssh2_pkt_send(ssh, s->pktout);
6407 logevent("Offered public key");
6409 crWaitUntilV(pktin);
6410 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6412 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
6413 continue; /* key refused; give up on it */
6416 logevent("Offer of public key accepted");
6418 * Actually attempt a serious authentication using
6421 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
6422 sprintf(s->pwprompt,
6423 "Passphrase for key \"%.100s\": ",
6429 if (flags & FLAG_VERBOSE) {
6430 c_write_str(ssh, "Authenticating with public key \"");
6431 c_write_str(ssh, comment);
6432 c_write_str(ssh, "\"\r\n");
6434 s->method = AUTH_PUBLICKEY_FILE;
6438 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
6439 s->method = AUTH_KEYBOARD_INTERACTIVE;
6440 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6441 s->tried_keyb_inter = TRUE;
6443 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6444 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
6446 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6447 ssh2_pkt_addstring(s->pktout, s->username);
6448 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6449 ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); /* method */
6450 ssh2_pkt_addstring(s->pktout, ""); /* lang */
6451 ssh2_pkt_addstring(s->pktout, "");
6452 ssh2_pkt_send(ssh, s->pktout);
6454 crWaitUntilV(pktin);
6455 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
6456 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
6458 logevent("Keyboard-interactive authentication refused");
6459 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
6463 s->kbd_inter_running = TRUE;
6467 if (s->kbd_inter_running) {
6468 s->method = AUTH_KEYBOARD_INTERACTIVE;
6469 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6470 s->tried_keyb_inter = TRUE;
6472 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6473 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
6475 if (s->curr_prompt == 0) {
6477 * We've got a fresh USERAUTH_INFO_REQUEST.
6478 * Display header data, and start going through
6481 char *name, *inst, *lang;
6482 int name_len, inst_len, lang_len;
6484 ssh_pkt_getstring(pktin, &name, &name_len);
6485 ssh_pkt_getstring(pktin, &inst, &inst_len);
6486 ssh_pkt_getstring(pktin, &lang, &lang_len);
6488 c_write_untrusted(ssh, name, name_len);
6489 c_write_str(ssh, "\r\n");
6492 c_write_untrusted(ssh, inst, inst_len);
6493 c_write_str(ssh, "\r\n");
6495 s->num_prompts = ssh_pkt_getuint32(pktin);
6499 * If there are prompts remaining in the packet,
6500 * display one and get a response.
6502 if (s->curr_prompt < s->num_prompts) {
6506 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
6507 if (prompt_len > 0) {
6508 static const char trunc[] = "<prompt truncated>: ";
6509 static const int prlen = sizeof(s->pwprompt) -
6511 if (prompt_len > prlen) {
6512 memcpy(s->pwprompt, prompt, prlen);
6513 strcpy(s->pwprompt + prlen, trunc);
6515 memcpy(s->pwprompt, prompt, prompt_len);
6516 s->pwprompt[prompt_len] = '\0';
6520 "<server failed to send prompt>: ");
6522 s->echo = ssh2_pkt_getbool(pktin);
6528 if (!s->method && s->can_passwd) {
6529 s->method = AUTH_PASSWORD;
6530 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6531 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
6532 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
6539 if (!ssh_get_line(s->pwprompt, s->password,
6540 sizeof(s->password), TRUE)) {
6542 * get_line failed to get a password (for
6543 * example because one was supplied on the
6544 * command line which has already failed to
6547 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6548 ssh2_pkt_adduint32(s->pktout,SSH2_DISCONNECT_BY_APPLICATION);
6549 ssh2_pkt_addstring(s->pktout, "No more passwords available"
6551 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
6552 ssh2_pkt_send_noqueue(ssh, s->pktout);
6553 logevent("Unable to authenticate");
6554 connection_fatal(ssh->frontend,
6555 "Unable to authenticate");
6556 ssh_closing((Plug)ssh, NULL, 0, 0);
6560 int ret; /* need not be saved across crReturn */
6561 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
6564 setup_userpass_input(ssh, s->password,
6565 sizeof(s->password), s->echo);
6567 crWaitUntilV(!pktin);
6568 ret = process_userpass_input(ssh, in, inlen);
6572 c_write_str(ssh, "\r\n");
6576 if (s->method == AUTH_PUBLICKEY_FILE) {
6578 * We have our passphrase. Now try the actual authentication.
6580 struct ssh2_userkey *key;
6581 const char *error = NULL;
6583 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
6585 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
6586 if (key == SSH2_WRONG_PASSPHRASE) {
6587 c_write_str(ssh, "Wrong passphrase\r\n");
6588 s->tried_pubkey_config = FALSE;
6590 c_write_str(ssh, "Unable to load private key (");
6591 c_write_str(ssh, error);
6592 c_write_str(ssh, ")\r\n");
6593 s->tried_pubkey_config = TRUE;
6595 /* Send a spurious AUTH_NONE to return to the top. */
6596 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6597 ssh2_pkt_addstring(s->pktout, s->username);
6598 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6599 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6600 ssh2_pkt_send(ssh, s->pktout);
6601 s->type = AUTH_TYPE_NONE;
6603 unsigned char *pkblob, *sigblob, *sigdata;
6604 int pkblob_len, sigblob_len, sigdata_len;
6608 * We have loaded the private key and the server
6609 * has announced that it's willing to accept it.
6610 * Hallelujah. Generate a signature and send it.
6612 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6613 ssh2_pkt_addstring(s->pktout, s->username);
6614 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6615 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6616 ssh2_pkt_addbool(s->pktout, TRUE);
6617 ssh2_pkt_addstring(s->pktout, key->alg->name);
6618 pkblob = key->alg->public_blob(key->data, &pkblob_len);
6619 ssh2_pkt_addstring_start(s->pktout);
6620 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len);
6623 * The data to be signed is:
6627 * followed by everything so far placed in the
6630 sigdata_len = s->pktout->length - 5 + 4 + 20;
6631 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6633 sigdata = snewn(sigdata_len, unsigned char);
6635 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6636 PUT_32BIT(sigdata+p, 20);
6639 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
6640 memcpy(sigdata+p, s->pktout->data + 5,
6641 s->pktout->length - 5);
6642 p += s->pktout->length - 5;
6643 assert(p == sigdata_len);
6644 sigblob = key->alg->sign(key->data, (char *)sigdata,
6645 sigdata_len, &sigblob_len);
6646 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
6647 sigblob, sigblob_len);
6652 ssh2_pkt_send(ssh, s->pktout);
6653 s->type = AUTH_TYPE_PUBLICKEY;
6654 key->alg->freekey(key->data);
6656 } else if (s->method == AUTH_PASSWORD) {
6658 * We send the password packet lumped tightly together with
6659 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
6660 * string long enough to make the total length of the two
6661 * packets constant. This should ensure that a passive
6662 * listener doing traffic analyis can't work out the length
6665 * For this to work, we need an assumption about the
6666 * maximum length of the password packet. I think 256 is
6667 * pretty conservative. Anyone using a password longer than
6668 * that probably doesn't have much to worry about from
6669 * people who find out how long their password is!
6671 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6672 ssh2_pkt_addstring(s->pktout, s->username);
6673 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6674 ssh2_pkt_addstring(s->pktout, "password");
6675 ssh2_pkt_addbool(s->pktout, FALSE);
6676 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6677 ssh2_pkt_addstring(s->pktout, s->password);
6678 memset(s->password, 0, sizeof(s->password));
6679 end_log_omission(ssh, s->pktout);
6680 ssh2_pkt_defer(ssh, s->pktout);
6682 * We'll include a string that's an exact multiple of the
6683 * cipher block size. If the cipher is NULL for some
6684 * reason, we don't do this trick at all because we gain
6687 if (ssh->cscipher) {
6690 stringlen = (256 - ssh->deferred_len);
6691 stringlen += ssh->cscipher->blksize - 1;
6692 stringlen -= (stringlen % ssh->cscipher->blksize);
6695 * Temporarily disable actual compression,
6696 * so we can guarantee to get this string
6697 * exactly the length we want it. The
6698 * compression-disabling routine should
6699 * return an integer indicating how many
6700 * bytes we should adjust our string length
6704 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
6706 s->pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
6707 ssh2_pkt_addstring_start(s->pktout);
6708 for (i = 0; i < stringlen; i++) {
6709 char c = (char) random_byte();
6710 ssh2_pkt_addstring_data(s->pktout, &c, 1);
6712 ssh2_pkt_defer(ssh, s->pktout);
6714 ssh_pkt_defersend(ssh);
6715 logevent("Sent password");
6716 s->type = AUTH_TYPE_PASSWORD;
6717 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
6718 if (s->curr_prompt == 0) {
6719 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
6720 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
6722 if (s->need_pw) { /* only add pw if we just got one! */
6723 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6724 ssh2_pkt_addstring(s->pktout, s->password);
6725 memset(s->password, 0, sizeof(s->password));
6726 end_log_omission(ssh, s->pktout);
6729 if (s->curr_prompt >= s->num_prompts) {
6730 ssh2_pkt_send(ssh, s->pktout);
6733 * If there are prompts remaining, we set
6734 * `gotit' so that we won't attempt to get
6735 * another packet. Then we go back round the
6736 * loop and will end up retrieving another
6737 * prompt out of the existing packet. Funky or
6742 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6744 c_write_str(ssh, "No supported authentication methods"
6745 " left to try!\r\n");
6746 logevent("No supported authentications offered."
6748 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6749 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
6750 ssh2_pkt_addstring(s->pktout, "No supported authentication"
6751 " methods available");
6752 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
6753 ssh2_pkt_send_noqueue(ssh, s->pktout);
6754 ssh_closing((Plug)ssh, NULL, 0, 0);
6758 } while (!s->we_are_in);
6761 * Now we're authenticated for the connection protocol. The
6762 * connection protocol will automatically have started at this
6763 * point; there's no need to send SERVICE_REQUEST.
6766 ssh->channels = newtree234(ssh_channelcmp);
6769 * Set up handlers for some connection protocol messages, so we
6770 * don't have to handle them repeatedly in this coroutine.
6772 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
6773 ssh2_msg_channel_window_adjust;
6774 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
6775 ssh2_msg_global_request;
6778 * Create the main session channel.
6780 if (!ssh->cfg.ssh_no_shell) {
6781 ssh->mainchan = snew(struct ssh_channel);
6782 ssh->mainchan->ssh = ssh;
6783 ssh->mainchan->localid = alloc_channel_id(ssh);
6784 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
6785 ssh2_pkt_addstring(s->pktout, "session");
6786 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
6787 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
6788 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
6789 ssh2_pkt_adduint32(s->pktout, 0x4000UL); /* our max pkt size */
6790 ssh2_pkt_send(ssh, s->pktout);
6791 crWaitUntilV(pktin);
6792 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
6793 bombout(("Server refused to open a session"));
6795 /* FIXME: error data comes back in FAILURE packet */
6797 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
6798 bombout(("Server's channel confirmation cited wrong channel"));
6801 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
6802 ssh->mainchan->type = CHAN_MAINSESSION;
6803 ssh->mainchan->closes = 0;
6804 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6805 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
6806 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
6807 add234(ssh->channels, ssh->mainchan);
6808 update_specials_menu(ssh->frontend);
6809 logevent("Opened channel for session");
6811 ssh->mainchan = NULL;
6814 * Now we have a channel, make dispatch table entries for
6815 * general channel-based messages.
6817 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
6818 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
6819 ssh2_msg_channel_data;
6820 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
6821 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
6822 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
6823 ssh2_msg_channel_open_confirmation;
6824 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
6825 ssh2_msg_channel_open_failure;
6826 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
6827 ssh2_msg_channel_request;
6828 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
6829 ssh2_msg_channel_open;
6832 * Potentially enable X11 forwarding.
6834 if (ssh->mainchan && ssh->cfg.x11_forward) {
6835 char proto[20], data[64];
6836 logevent("Requesting X11 forwarding");
6837 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
6838 data, sizeof(data), ssh->cfg.x11_auth);
6839 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
6840 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6841 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6842 ssh2_pkt_addstring(s->pktout, "x11-req");
6843 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6844 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
6845 ssh2_pkt_addstring(s->pktout, proto);
6846 ssh2_pkt_addstring(s->pktout, data);
6847 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
6848 ssh2_pkt_send(ssh, s->pktout);
6850 crWaitUntilV(pktin);
6852 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6853 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6854 bombout(("Unexpected response to X11 forwarding request:"
6855 " packet type %d", pktin->type));
6858 logevent("X11 forwarding refused");
6860 logevent("X11 forwarding enabled");
6861 ssh->X11_fwd_enabled = TRUE;
6866 * Enable port forwardings.
6868 ssh_setup_portfwd(ssh, &ssh->cfg);
6871 * Potentially enable agent forwarding.
6873 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
6874 logevent("Requesting OpenSSH-style agent forwarding");
6875 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6876 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6877 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
6878 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6879 ssh2_pkt_send(ssh, s->pktout);
6881 crWaitUntilV(pktin);
6883 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6884 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6885 bombout(("Unexpected response to agent forwarding request:"
6886 " packet type %d", pktin->type));
6889 logevent("Agent forwarding refused");
6891 logevent("Agent forwarding enabled");
6892 ssh->agentfwd_enabled = TRUE;
6897 * Now allocate a pty for the session.
6899 if (ssh->mainchan && !ssh->cfg.nopty) {
6900 /* Unpick the terminal-speed string. */
6901 /* XXX perhaps we should allow no speeds to be sent. */
6902 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
6903 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
6904 /* Build the pty request. */
6905 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6906 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
6907 ssh2_pkt_addstring(s->pktout, "pty-req");
6908 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6909 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
6910 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
6911 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
6912 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
6913 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
6914 ssh2_pkt_addstring_start(s->pktout);
6915 ssh2_pkt_addbyte(s->pktout, 128); /* TTY_OP_ISPEED */
6916 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
6917 ssh2_pkt_addbyte(s->pktout, 129); /* TTY_OP_OSPEED */
6918 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
6919 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
6920 ssh2_pkt_send(ssh, s->pktout);
6921 ssh->state = SSH_STATE_INTERMED;
6923 crWaitUntilV(pktin);
6925 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6926 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6927 bombout(("Unexpected response to pty request:"
6928 " packet type %d", pktin->type));
6931 c_write_str(ssh, "Server refused to allocate pty\r\n");
6932 ssh->editing = ssh->echoing = 1;
6934 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
6935 ssh->ospeed, ssh->ispeed);
6938 ssh->editing = ssh->echoing = 1;
6942 * Send environment variables.
6944 * Simplest thing here is to send all the requests at once, and
6945 * then wait for a whole bunch of successes or failures.
6947 if (ssh->mainchan && *ssh->cfg.environmt) {
6948 char *e = ssh->cfg.environmt;
6949 char *var, *varend, *val;
6955 while (*e && *e != '\t') e++;
6957 if (*e == '\t') e++;
6962 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6963 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6964 ssh2_pkt_addstring(s->pktout, "env");
6965 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6966 ssh2_pkt_addstring_start(s->pktout);
6967 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
6968 ssh2_pkt_addstring(s->pktout, val);
6969 ssh2_pkt_send(ssh, s->pktout);
6974 logeventf(ssh, "Sent %d environment variables", s->num_env);
6977 s->env_left = s->num_env;
6979 while (s->env_left > 0) {
6980 crWaitUntilV(pktin);
6982 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6983 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6984 bombout(("Unexpected response to environment request:"
6985 " packet type %d", pktin->type));
6995 if (s->env_ok == s->num_env) {
6996 logevent("All environment variables successfully set");
6997 } else if (s->env_ok == 0) {
6998 logevent("All environment variables refused");
6999 c_write_str(ssh, "Server refused to set environment variables\r\n");
7001 logeventf(ssh, "%d environment variables refused",
7002 s->num_env - s->env_ok);
7003 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7008 * Start a shell or a remote command. We may have to attempt
7009 * this twice if the config data has provided a second choice
7012 if (ssh->mainchan) while (1) {
7016 if (ssh->fallback_cmd) {
7017 subsys = ssh->cfg.ssh_subsys2;
7018 cmd = ssh->cfg.remote_cmd_ptr2;
7020 subsys = ssh->cfg.ssh_subsys;
7021 cmd = ssh->cfg.remote_cmd_ptr;
7024 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7025 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
7027 ssh2_pkt_addstring(s->pktout, "subsystem");
7028 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7029 ssh2_pkt_addstring(s->pktout, cmd);
7031 ssh2_pkt_addstring(s->pktout, "exec");
7032 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7033 ssh2_pkt_addstring(s->pktout, cmd);
7035 ssh2_pkt_addstring(s->pktout, "shell");
7036 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7038 ssh2_pkt_send(ssh, s->pktout);
7040 crWaitUntilV(pktin);
7042 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7043 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7044 bombout(("Unexpected response to shell/command request:"
7045 " packet type %d", pktin->type));
7049 * We failed to start the command. If this is the
7050 * fallback command, we really are finished; if it's
7051 * not, and if the fallback command exists, try falling
7052 * back to it before complaining.
7054 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
7055 logevent("Primary command failed; attempting fallback");
7056 ssh->fallback_cmd = TRUE;
7059 bombout(("Server refused to start a shell/command"));
7062 logevent("Started a shell/command");
7067 ssh->state = SSH_STATE_SESSION;
7068 if (ssh->size_needed)
7069 ssh_size(ssh, ssh->term_width, ssh->term_height);
7070 if (ssh->eof_needed)
7071 ssh_special(ssh, TS_EOF);
7077 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
7082 s->try_send = FALSE;
7086 * _All_ the connection-layer packets we expect to
7087 * receive are now handled by the dispatch table.
7088 * Anything that reaches here must be bogus.
7091 bombout(("Strange packet received: type %d", pktin->type));
7093 } else if (ssh->mainchan) {
7095 * We have spare data. Add it to the channel buffer.
7097 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
7102 struct ssh_channel *c;
7104 * Try to send data on all channels if we can.
7106 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
7109 continue; /* don't send on closing channels */
7110 bufsize = ssh2_try_send(c);
7113 case CHAN_MAINSESSION:
7114 /* stdin need not receive an unthrottle
7115 * notification since it will be polled */
7118 x11_unthrottle(c->u.x11.s);
7121 /* agent sockets are request/response and need no
7122 * buffer management */
7125 pfd_unthrottle(c->u.pfd.s);
7137 * Handlers for SSH2 messages that might arrive at any moment.
7139 void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
7141 /* log reason code in disconnect message */
7143 int nowlen, reason, msglen;
7145 reason = ssh_pkt_getuint32(pktin);
7146 ssh_pkt_getstring(pktin, &msg, &msglen);
7148 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
7149 buf = dupprintf("Received disconnect message (%s)",
7150 ssh2_disconnect_reasons[reason]);
7152 buf = dupprintf("Received disconnect message (unknown"
7153 " type %d)", reason);
7157 buf = dupprintf("Disconnection message text: %n%.*s",
7158 &nowlen, msglen, msg);
7160 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
7162 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
7163 ssh2_disconnect_reasons[reason] : "unknown",
7168 void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
7170 /* log the debug message */
7175 /* XXX maybe we should actually take notice of this */
7176 always_display = ssh2_pkt_getbool(pktin);
7177 ssh_pkt_getstring(pktin, &msg, &msglen);
7179 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
7184 void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
7186 struct Packet *pktout;
7187 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
7188 ssh2_pkt_adduint32(pktout, pktin->sequence);
7190 * UNIMPLEMENTED messages MUST appear in the same order as the
7191 * messages they respond to. Hence, never queue them.
7193 ssh2_pkt_send_noqueue(ssh, pktout);
7197 * Handle the top-level SSH2 protocol.
7199 static void ssh2_protocol_setup(Ssh ssh)
7204 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
7206 for (i = 0; i < 256; i++)
7207 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
7210 * Any message we actually understand, we set to NULL so that
7211 * the coroutines will get it.
7213 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
7214 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
7215 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
7216 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
7217 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
7218 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
7219 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
7220 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
7221 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
7222 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
7223 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
7224 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
7225 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
7226 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
7227 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7228 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
7229 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
7230 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
7231 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
7232 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
7233 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
7234 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
7235 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
7236 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
7237 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
7238 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
7239 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
7240 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
7241 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
7242 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
7243 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
7244 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
7245 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
7248 * These special message types we install handlers for.
7250 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
7251 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with ssh1 */
7252 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
7255 static void ssh2_timer(void *ctx, long now)
7259 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
7260 now - ssh->next_rekey >= 0) {
7261 do_ssh2_transport(ssh, "Initiating key re-exchange (timeout)",
7266 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
7267 struct Packet *pktin)
7269 if (ssh->state == SSH_STATE_CLOSED)
7273 ssh->incoming_data_size += pktin->encrypted_len;
7274 if (!ssh->kex_in_progress &&
7275 ssh->max_data_size != 0 &&
7276 ssh->incoming_data_size > ssh->max_data_size)
7277 do_ssh2_transport(ssh, "Initiating key re-exchange "
7278 "(too much data received)", -1, NULL);
7281 if (pktin && ssh->packet_dispatch[pktin->type]) {
7282 ssh->packet_dispatch[pktin->type](ssh, pktin);
7286 if (!ssh->protocol_initial_phase_done ||
7287 (pktin && pktin->type >= 20 && pktin->type < 50)) {
7288 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
7289 !ssh->protocol_initial_phase_done) {
7290 ssh->protocol_initial_phase_done = TRUE;
7292 * Allow authconn to initialise itself.
7294 do_ssh2_authconn(ssh, NULL, 0, NULL);
7297 do_ssh2_authconn(ssh, in, inlen, pktin);
7302 * Called to set up the connection.
7304 * Returns an error message, or NULL on success.
7306 static const char *ssh_init(void *frontend_handle, void **backend_handle,
7308 char *host, int port, char **realhost, int nodelay,
7314 ssh = snew(struct ssh_tag);
7315 ssh->cfg = *cfg; /* STRUCTURE COPY */
7316 ssh->version = 0; /* when not ready yet */
7319 ssh->v1_cipher_ctx = NULL;
7320 ssh->crcda_ctx = NULL;
7321 ssh->cscipher = NULL;
7322 ssh->cs_cipher_ctx = NULL;
7323 ssh->sccipher = NULL;
7324 ssh->sc_cipher_ctx = NULL;
7326 ssh->cs_mac_ctx = NULL;
7328 ssh->sc_mac_ctx = NULL;
7330 ssh->cs_comp_ctx = NULL;
7332 ssh->sc_comp_ctx = NULL;
7334 ssh->kex_ctx = NULL;
7335 ssh->hostkey = NULL;
7337 ssh->state = SSH_STATE_PREPACKET;
7338 ssh->size_needed = FALSE;
7339 ssh->eof_needed = FALSE;
7342 ssh->deferred_send_data = NULL;
7343 ssh->deferred_len = 0;
7344 ssh->deferred_size = 0;
7345 ssh->fallback_cmd = 0;
7347 ssh->x11auth = NULL;
7348 ssh->v1_compressing = FALSE;
7349 ssh->v2_outgoing_sequence = 0;
7350 ssh->ssh1_rdpkt_crstate = 0;
7351 ssh->ssh2_rdpkt_crstate = 0;
7352 ssh->do_ssh_init_crstate = 0;
7353 ssh->ssh_gotdata_crstate = 0;
7354 ssh->do_ssh1_connection_crstate = 0;
7355 ssh->do_ssh1_login_crstate = 0;
7356 ssh->do_ssh2_transport_crstate = 0;
7357 ssh->do_ssh2_authconn_crstate = 0;
7358 ssh->do_ssh_init_state = NULL;
7359 ssh->do_ssh1_login_state = NULL;
7360 ssh->do_ssh2_transport_state = NULL;
7361 ssh->do_ssh2_authconn_state = NULL;
7362 ssh->mainchan = NULL;
7363 ssh->throttled_all = 0;
7364 ssh->v1_stdout_throttling = 0;
7366 ssh->queuelen = ssh->queuesize = 0;
7367 ssh->queueing = FALSE;
7368 ssh->qhead = ssh->qtail = NULL;
7370 *backend_handle = ssh;
7373 if (crypto_startup() == 0)
7374 return "Microsoft high encryption pack not installed!";
7377 ssh->frontend = frontend_handle;
7378 ssh->term_width = ssh->cfg.width;
7379 ssh->term_height = ssh->cfg.height;
7381 ssh->channels = NULL;
7382 ssh->rportfwds = NULL;
7383 ssh->portfwds = NULL;
7388 ssh->v1_throttle_count = 0;
7389 ssh->overall_bufsize = 0;
7390 ssh->fallback_cmd = 0;
7392 ssh->protocol = NULL;
7394 ssh->protocol_initial_phase_done = FALSE;
7398 ssh->incoming_data_size = ssh->outgoing_data_size =
7399 ssh->deferred_data_size = 0L;
7400 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
7401 ssh->kex_in_progress = FALSE;
7403 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
7412 static void ssh_free(void *handle)
7414 Ssh ssh = (Ssh) handle;
7415 struct ssh_channel *c;
7416 struct ssh_rportfwd *pf;
7418 if (ssh->v1_cipher_ctx)
7419 ssh->cipher->free_context(ssh->v1_cipher_ctx);
7420 if (ssh->cs_cipher_ctx)
7421 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7422 if (ssh->sc_cipher_ctx)
7423 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7424 if (ssh->cs_mac_ctx)
7425 ssh->csmac->free_context(ssh->cs_mac_ctx);
7426 if (ssh->sc_mac_ctx)
7427 ssh->scmac->free_context(ssh->sc_mac_ctx);
7428 if (ssh->cs_comp_ctx) {
7430 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7432 zlib_compress_cleanup(ssh->cs_comp_ctx);
7434 if (ssh->sc_comp_ctx) {
7436 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7438 zlib_decompress_cleanup(ssh->sc_comp_ctx);
7441 dh_cleanup(ssh->kex_ctx);
7442 sfree(ssh->savedhost);
7444 while (ssh->queuelen-- > 0)
7445 ssh_free_packet(ssh->queue[ssh->queuelen]);
7448 while (ssh->qhead) {
7449 struct queued_handler *qh = ssh->qhead;
7450 ssh->qhead = qh->next;
7453 ssh->qhead = ssh->qtail = NULL;
7455 if (ssh->channels) {
7456 while ((c = delpos234(ssh->channels, 0)) != NULL) {
7459 if (c->u.x11.s != NULL)
7460 x11_close(c->u.x11.s);
7463 if (c->u.pfd.s != NULL)
7464 pfd_close(c->u.pfd.s);
7469 freetree234(ssh->channels);
7470 ssh->channels = NULL;
7473 if (ssh->rportfwds) {
7474 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
7476 freetree234(ssh->rportfwds);
7477 ssh->rportfwds = NULL;
7479 sfree(ssh->deferred_send_data);
7481 x11_free_auth(ssh->x11auth);
7482 sfree(ssh->do_ssh_init_state);
7483 sfree(ssh->do_ssh1_login_state);
7484 sfree(ssh->do_ssh2_transport_state);
7485 sfree(ssh->do_ssh2_authconn_state);
7486 if (ssh->crcda_ctx) {
7487 crcda_free_context(ssh->crcda_ctx);
7488 ssh->crcda_ctx = NULL;
7492 expire_timer_context(ssh);
7494 pinger_free(ssh->pinger);
7501 * Reconfigure the SSH backend.
7503 static void ssh_reconfig(void *handle, Config *cfg)
7505 Ssh ssh = (Ssh) handle;
7506 char *rekeying = NULL;
7507 unsigned long old_max_data_size;
7509 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
7510 ssh_setup_portfwd(ssh, cfg);
7512 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
7513 cfg->ssh_rekey_time != 0) {
7514 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
7515 long now = GETTICKCOUNT();
7517 if (new_next - now < 0) {
7518 rekeying = "Initiating key re-exchange (timeout shortened)";
7520 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
7524 old_max_data_size = ssh->max_data_size;
7525 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
7526 if (old_max_data_size != ssh->max_data_size &&
7527 ssh->max_data_size != 0) {
7528 if (ssh->outgoing_data_size > ssh->max_data_size ||
7529 ssh->incoming_data_size > ssh->max_data_size)
7530 rekeying = "Initiating key re-exchange (data limit lowered)";
7533 if (rekeying && !ssh->kex_in_progress) {
7534 do_ssh2_transport(ssh, rekeying, -1, NULL);
7537 ssh->cfg = *cfg; /* STRUCTURE COPY */
7541 * Called to send data down the Telnet connection.
7543 static int ssh_send(void *handle, char *buf, int len)
7545 Ssh ssh = (Ssh) handle;
7547 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
7550 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
7552 return ssh_sendbuffer(ssh);
7556 * Called to query the current amount of buffered stdin data.
7558 static int ssh_sendbuffer(void *handle)
7560 Ssh ssh = (Ssh) handle;
7563 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
7567 * If the SSH socket itself has backed up, add the total backup
7568 * size on that to any individual buffer on the stdin channel.
7571 if (ssh->throttled_all)
7572 override_value = ssh->overall_bufsize;
7574 if (ssh->version == 1) {
7575 return override_value;
7576 } else if (ssh->version == 2) {
7577 if (!ssh->mainchan || ssh->mainchan->closes > 0)
7578 return override_value;
7580 return (override_value +
7581 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
7588 * Called to set the size of the window from SSH's POV.
7590 static void ssh_size(void *handle, int width, int height)
7592 Ssh ssh = (Ssh) handle;
7593 struct Packet *pktout;
7595 ssh->term_width = width;
7596 ssh->term_height = height;
7598 switch (ssh->state) {
7599 case SSH_STATE_BEFORE_SIZE:
7600 case SSH_STATE_PREPACKET:
7601 case SSH_STATE_CLOSED:
7602 break; /* do nothing */
7603 case SSH_STATE_INTERMED:
7604 ssh->size_needed = TRUE; /* buffer for later */
7606 case SSH_STATE_SESSION:
7607 if (!ssh->cfg.nopty) {
7608 if (ssh->version == 1) {
7609 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
7610 PKT_INT, ssh->term_height,
7611 PKT_INT, ssh->term_width,
7612 PKT_INT, 0, PKT_INT, 0, PKT_END);
7613 } else if (ssh->mainchan) {
7614 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7615 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7616 ssh2_pkt_addstring(pktout, "window-change");
7617 ssh2_pkt_addbool(pktout, 0);
7618 ssh2_pkt_adduint32(pktout, ssh->term_width);
7619 ssh2_pkt_adduint32(pktout, ssh->term_height);
7620 ssh2_pkt_adduint32(pktout, 0);
7621 ssh2_pkt_adduint32(pktout, 0);
7622 ssh2_pkt_send(ssh, pktout);
7630 * Return a list of the special codes that make sense in this
7633 static const struct telnet_special *ssh_get_specials(void *handle)
7635 static const struct telnet_special ssh1_ignore_special[] = {
7636 {"IGNORE message", TS_NOP}
7638 static const struct telnet_special ssh2_transport_specials[] = {
7639 {"IGNORE message", TS_NOP},
7640 {"Repeat key exchange", TS_REKEY},
7642 static const struct telnet_special ssh2_session_specials[] = {
7645 /* These are the signal names defined by draft-ietf-secsh-connect-23.
7646 * They include all the ISO C signals, but are a subset of the POSIX
7647 * required signals. */
7648 {"SIGINT (Interrupt)", TS_SIGINT},
7649 {"SIGTERM (Terminate)", TS_SIGTERM},
7650 {"SIGKILL (Kill)", TS_SIGKILL},
7651 {"SIGQUIT (Quit)", TS_SIGQUIT},
7652 {"SIGHUP (Hangup)", TS_SIGHUP},
7653 {"More signals", TS_SUBMENU},
7654 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
7655 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
7656 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
7657 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
7660 static const struct telnet_special specials_end[] = {
7663 /* XXX review this length for any changes: */
7664 static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
7665 lenof(ssh2_session_specials) +
7666 lenof(specials_end)];
7667 Ssh ssh = (Ssh) handle;
7669 #define ADD_SPECIALS(name) \
7671 assert((i + lenof(name)) <= lenof(ssh_specials)); \
7672 memcpy(&ssh_specials[i], name, sizeof name); \
7676 if (ssh->version == 1) {
7677 /* Don't bother offering IGNORE if we've decided the remote
7678 * won't cope with it, since we wouldn't bother sending it if
7680 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7681 ADD_SPECIALS(ssh1_ignore_special);
7682 } else if (ssh->version == 2) {
7683 ADD_SPECIALS(ssh2_transport_specials);
7685 ADD_SPECIALS(ssh2_session_specials);
7686 } /* else we're not ready yet */
7689 ADD_SPECIALS(specials_end);
7690 return ssh_specials;
7698 * Send Telnet special codes. TS_EOF is useful for `plink', so you
7699 * can send an EOF and collect resulting output (e.g. `plink
7702 static void ssh_special(void *handle, Telnet_Special code)
7704 Ssh ssh = (Ssh) handle;
7705 struct Packet *pktout;
7707 if (code == TS_EOF) {
7708 if (ssh->state != SSH_STATE_SESSION) {
7710 * Buffer the EOF in case we are pre-SESSION, so we can
7711 * send it as soon as we reach SESSION.
7714 ssh->eof_needed = TRUE;
7717 if (ssh->version == 1) {
7718 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
7719 } else if (ssh->mainchan) {
7720 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
7721 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7722 ssh2_pkt_send(ssh, pktout);
7724 logevent("Sent EOF message");
7725 } else if (code == TS_PING || code == TS_NOP) {
7726 if (ssh->state == SSH_STATE_CLOSED
7727 || ssh->state == SSH_STATE_PREPACKET) return;
7728 if (ssh->version == 1) {
7729 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7730 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
7732 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
7733 ssh2_pkt_addstring_start(pktout);
7734 ssh2_pkt_send_noqueue(ssh, pktout);
7736 } else if (code == TS_REKEY) {
7737 if (!ssh->kex_in_progress && ssh->version == 2) {
7738 do_ssh2_transport(ssh, "Initiating key re-exchange at"
7739 " user request", -1, NULL);
7741 } else if (code == TS_BRK) {
7742 if (ssh->state == SSH_STATE_CLOSED
7743 || ssh->state == SSH_STATE_PREPACKET) return;
7744 if (ssh->version == 1) {
7745 logevent("Unable to send BREAK signal in SSH1");
7746 } else if (ssh->mainchan) {
7747 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7748 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7749 ssh2_pkt_addstring(pktout, "break");
7750 ssh2_pkt_addbool(pktout, 0);
7751 ssh2_pkt_adduint32(pktout, 0); /* default break length */
7752 ssh2_pkt_send(ssh, pktout);
7755 /* Is is a POSIX signal? */
7756 char *signame = NULL;
7757 if (code == TS_SIGABRT) signame = "ABRT";
7758 if (code == TS_SIGALRM) signame = "ALRM";
7759 if (code == TS_SIGFPE) signame = "FPE";
7760 if (code == TS_SIGHUP) signame = "HUP";
7761 if (code == TS_SIGILL) signame = "ILL";
7762 if (code == TS_SIGINT) signame = "INT";
7763 if (code == TS_SIGKILL) signame = "KILL";
7764 if (code == TS_SIGPIPE) signame = "PIPE";
7765 if (code == TS_SIGQUIT) signame = "QUIT";
7766 if (code == TS_SIGSEGV) signame = "SEGV";
7767 if (code == TS_SIGTERM) signame = "TERM";
7768 if (code == TS_SIGUSR1) signame = "USR1";
7769 if (code == TS_SIGUSR2) signame = "USR2";
7770 /* The SSH-2 protocol does in principle support arbitrary named
7771 * signals, including signame@domain, but we don't support those. */
7773 /* It's a signal. */
7774 if (ssh->version == 2 && ssh->mainchan) {
7775 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7776 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7777 ssh2_pkt_addstring(pktout, "signal");
7778 ssh2_pkt_addbool(pktout, 0);
7779 ssh2_pkt_addstring(pktout, signame);
7780 ssh2_pkt_send(ssh, pktout);
7781 logeventf(ssh, "Sent signal SIG%s", signame);
7784 /* Never heard of it. Do nothing */
7789 void *new_sock_channel(void *handle, Socket s)
7791 Ssh ssh = (Ssh) handle;
7792 struct ssh_channel *c;
7793 c = snew(struct ssh_channel);
7797 c->remoteid = -1; /* to be set when open confirmed */
7798 c->localid = alloc_channel_id(ssh);
7800 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
7802 bufchain_init(&c->v.v2.outbuffer);
7803 add234(ssh->channels, c);
7809 * This is called when stdout/stderr (the entity to which
7810 * from_backend sends data) manages to clear some backlog.
7812 static void ssh_unthrottle(void *handle, int bufsize)
7814 Ssh ssh = (Ssh) handle;
7815 if (ssh->version == 1) {
7816 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
7817 ssh->v1_stdout_throttling = 0;
7818 ssh1_throttle(ssh, -1);
7821 if (ssh->mainchan && ssh->mainchan->closes == 0)
7822 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
7826 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
7828 struct ssh_channel *c = (struct ssh_channel *)channel;
7830 struct Packet *pktout;
7832 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
7834 if (ssh->version == 1) {
7835 send_packet(ssh, SSH1_MSG_PORT_OPEN,
7836 PKT_INT, c->localid,
7839 /* PKT_STR, <org:orgport>, */
7842 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7843 ssh2_pkt_addstring(pktout, "direct-tcpip");
7844 ssh2_pkt_adduint32(pktout, c->localid);
7845 c->v.v2.locwindow = OUR_V2_WINSIZE;
7846 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7847 ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
7848 ssh2_pkt_addstring(pktout, hostname);
7849 ssh2_pkt_adduint32(pktout, port);
7851 * We make up values for the originator data; partly it's
7852 * too much hassle to keep track, and partly I'm not
7853 * convinced the server should be told details like that
7854 * about my local network configuration.
7856 ssh2_pkt_addstring(pktout, "client-side-connection");
7857 ssh2_pkt_adduint32(pktout, 0);
7858 ssh2_pkt_send(ssh, pktout);
7862 static Socket ssh_socket(void *handle)
7864 Ssh ssh = (Ssh) handle;
7868 static int ssh_sendok(void *handle)
7870 Ssh ssh = (Ssh) handle;
7871 return ssh->send_ok;
7874 static int ssh_ldisc(void *handle, int option)
7876 Ssh ssh = (Ssh) handle;
7877 if (option == LD_ECHO)
7878 return ssh->echoing;
7879 if (option == LD_EDIT)
7880 return ssh->editing;
7884 static void ssh_provide_ldisc(void *handle, void *ldisc)
7886 Ssh ssh = (Ssh) handle;
7890 static void ssh_provide_logctx(void *handle, void *logctx)
7892 Ssh ssh = (Ssh) handle;
7893 ssh->logctx = logctx;
7896 static int ssh_return_exitcode(void *handle)
7898 Ssh ssh = (Ssh) handle;
7902 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
7906 * cfg_info for SSH is the currently running version of the
7907 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
7909 static int ssh_cfg_info(void *handle)
7911 Ssh ssh = (Ssh) handle;
7912 return ssh->version;
7916 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
7917 * that fails. This variable is the means by which scp.c can reach
7918 * into the SSH code and find out which one it got.
7920 extern int ssh_fallback_cmd(void *handle)
7922 Ssh ssh = (Ssh) handle;
7923 return ssh->fallback_cmd;
7926 Backend ssh_backend = {
7936 ssh_return_exitcode,