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;
753 char *deferred_rekey_reason; /* points to STATIC string; don't free */
756 #define logevent(s) logevent(ssh->frontend, s)
758 /* logevent, only printf-formatted. */
759 static void logeventf(Ssh ssh, const char *fmt, ...)
765 buf = dupvprintf(fmt, ap);
771 #define bombout(msg) \
773 char *text = dupprintf msg; \
776 connection_fatal(ssh->frontend, "%s", text); \
780 /* Functions to leave bits out of the SSH packet log file. */
782 static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
784 if (ssh->cfg.logomitpass)
785 pkt->logmode = blanktype;
788 static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
790 if (ssh->cfg.logomitdata)
791 pkt->logmode = blanktype;
794 static void end_log_omission(Ssh ssh, struct Packet *pkt)
796 pkt->logmode = PKTLOG_EMIT;
799 static int ssh_channelcmp(void *av, void *bv)
801 struct ssh_channel *a = (struct ssh_channel *) av;
802 struct ssh_channel *b = (struct ssh_channel *) bv;
803 if (a->localid < b->localid)
805 if (a->localid > b->localid)
809 static int ssh_channelfind(void *av, void *bv)
811 unsigned *a = (unsigned *) av;
812 struct ssh_channel *b = (struct ssh_channel *) bv;
820 static int ssh_rportcmp_ssh1(void *av, void *bv)
822 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
823 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
825 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
826 return i < 0 ? -1 : +1;
827 if (a->dport > b->dport)
829 if (a->dport < b->dport)
834 static int ssh_rportcmp_ssh2(void *av, void *bv)
836 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
837 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
839 if (a->sport > b->sport)
841 if (a->sport < b->sport)
847 * Special form of strcmp which can cope with NULL inputs. NULL is
848 * defined to sort before even the empty string.
850 static int nullstrcmp(const char *a, const char *b)
852 if (a == NULL && b == NULL)
861 static int ssh_portcmp(void *av, void *bv)
863 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
864 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
866 if (a->type > b->type)
868 if (a->type < b->type)
870 if (a->addressfamily > b->addressfamily)
872 if (a->addressfamily < b->addressfamily)
874 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
875 return i < 0 ? -1 : +1;
876 if (a->sport > b->sport)
878 if (a->sport < b->sport)
880 if (a->type != 'D') {
881 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
882 return i < 0 ? -1 : +1;
883 if (a->dport > b->dport)
885 if (a->dport < b->dport)
891 static int alloc_channel_id(Ssh ssh)
893 const unsigned CHANNEL_NUMBER_OFFSET = 256;
894 unsigned low, high, mid;
896 struct ssh_channel *c;
899 * First-fit allocation of channel numbers: always pick the
900 * lowest unused one. To do this, binary-search using the
901 * counted B-tree to find the largest channel ID which is in a
902 * contiguous sequence from the beginning. (Precisely
903 * everything in that sequence must have ID equal to its tree
904 * index plus CHANNEL_NUMBER_OFFSET.)
906 tsize = count234(ssh->channels);
910 while (high - low > 1) {
911 mid = (high + low) / 2;
912 c = index234(ssh->channels, mid);
913 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
914 low = mid; /* this one is fine */
916 high = mid; /* this one is past it */
919 * Now low points to either -1, or the tree index of the
920 * largest ID in the initial sequence.
923 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
924 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
926 return low + 1 + CHANNEL_NUMBER_OFFSET;
929 static void c_write(Ssh ssh, const char *buf, int len)
931 if ((flags & FLAG_STDERR)) {
933 for (i = 0; i < len; i++)
935 fputc(buf[i], stderr);
938 from_backend(ssh->frontend, 1, buf, len);
941 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
944 for (i = 0; i < len; i++) {
946 c_write(ssh, "\r\n", 2);
947 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
948 c_write(ssh, buf + i, 1);
952 static void c_write_str(Ssh ssh, const char *buf)
954 c_write(ssh, buf, strlen(buf));
957 static void ssh_free_packet(struct Packet *pkt)
962 static struct Packet *ssh_new_packet(void)
964 struct Packet *pkt = snew(struct Packet);
968 pkt->logmode = PKTLOG_EMIT;
976 * Collect incoming data in the incoming packet buffer.
977 * Decipher and verify the packet when it is completely read.
978 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
979 * Update the *data and *datalen variables.
980 * Return a Packet structure when a packet is completed.
982 static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
984 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
986 crBegin(ssh->ssh1_rdpkt_crstate);
988 st->pktin = ssh_new_packet();
991 st->pktin->length = 0;
993 for (st->i = st->len = 0; st->i < 4; st->i++) {
994 while ((*datalen) == 0)
996 st->len = (st->len << 8) + **data;
997 (*data)++, (*datalen)--;
1000 st->pad = 8 - (st->len % 8);
1001 st->biglen = st->len + st->pad;
1002 st->pktin->length = st->len - 5;
1004 if (st->biglen < 0) {
1005 bombout(("Extremely large packet length from server suggests"
1006 " data stream corruption"));
1007 ssh_free_packet(st->pktin);
1011 st->pktin->maxlen = st->biglen;
1012 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1014 st->to_read = st->biglen;
1015 st->p = st->pktin->data;
1016 while (st->to_read > 0) {
1017 st->chunk = st->to_read;
1018 while ((*datalen) == 0)
1020 if (st->chunk > (*datalen))
1021 st->chunk = (*datalen);
1022 memcpy(st->p, *data, st->chunk);
1024 *datalen -= st->chunk;
1026 st->to_read -= st->chunk;
1029 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1030 st->biglen, NULL)) {
1031 bombout(("Network attack (CRC compensation) detected!"));
1032 ssh_free_packet(st->pktin);
1037 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1039 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1040 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1041 if (st->gotcrc != st->realcrc) {
1042 bombout(("Incorrect CRC received on packet"));
1043 ssh_free_packet(st->pktin);
1047 st->pktin->body = st->pktin->data + st->pad + 1;
1048 st->pktin->savedpos = 0;
1050 if (ssh->v1_compressing) {
1051 unsigned char *decompblk;
1053 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1054 st->pktin->body - 1, st->pktin->length + 1,
1055 &decompblk, &decomplen)) {
1056 bombout(("Zlib decompression encountered invalid data"));
1057 ssh_free_packet(st->pktin);
1061 if (st->pktin->maxlen < st->pad + decomplen) {
1062 st->pktin->maxlen = st->pad + decomplen;
1063 st->pktin->data = sresize(st->pktin->data,
1064 st->pktin->maxlen + APIEXTRA,
1066 st->pktin->body = st->pktin->data + st->pad + 1;
1069 memcpy(st->pktin->body - 1, decompblk, decomplen);
1071 st->pktin->length = decomplen - 1;
1074 st->pktin->type = st->pktin->body[-1];
1077 * Log incoming packet, possibly omitting sensitive fields.
1081 struct logblank_t blank;
1082 if (ssh->cfg.logomitdata) {
1083 int do_blank = FALSE, blank_prefix = 0;
1084 /* "Session data" packets - omit the data field */
1085 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1086 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
1087 do_blank = TRUE; blank_prefix = 0;
1088 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
1089 do_blank = TRUE; blank_prefix = 4;
1092 blank.offset = blank_prefix;
1093 blank.len = st->pktin->length;
1094 blank.type = PKTLOG_OMIT;
1098 log_packet(ssh->logctx,
1099 PKT_INCOMING, st->pktin->type,
1100 ssh1_pkt_type(st->pktin->type),
1101 st->pktin->body, st->pktin->length,
1105 crFinish(st->pktin);
1108 static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1110 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1112 crBegin(ssh->ssh2_rdpkt_crstate);
1114 st->pktin = ssh_new_packet();
1116 st->pktin->type = 0;
1117 st->pktin->length = 0;
1119 st->cipherblk = ssh->sccipher->blksize;
1122 if (st->cipherblk < 8)
1125 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1128 * Acquire and decrypt the first block of the packet. This will
1129 * contain the length and padding details.
1131 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1132 while ((*datalen) == 0)
1134 st->pktin->data[st->i] = *(*data)++;
1139 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1140 st->pktin->data, st->cipherblk);
1143 * Now get the length and padding figures.
1145 st->len = GET_32BIT(st->pktin->data);
1146 st->pad = st->pktin->data[4];
1149 * _Completely_ silly lengths should be stomped on before they
1150 * do us any more damage.
1152 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
1153 bombout(("Incoming packet was garbled on decryption"));
1154 ssh_free_packet(st->pktin);
1159 * This enables us to deduce the payload length.
1161 st->payload = st->len - st->pad - 1;
1163 st->pktin->length = st->payload + 5;
1166 * So now we can work out the total packet length.
1168 st->packetlen = st->len + 4;
1169 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1172 * Allocate memory for the rest of the packet.
1174 st->pktin->maxlen = st->packetlen + st->maclen;
1175 st->pktin->data = sresize(st->pktin->data,
1176 st->pktin->maxlen + APIEXTRA,
1180 * Read and decrypt the remainder of the packet.
1182 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1184 while ((*datalen) == 0)
1186 st->pktin->data[st->i] = *(*data)++;
1189 /* Decrypt everything _except_ the MAC. */
1191 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1192 st->pktin->data + st->cipherblk,
1193 st->packetlen - st->cipherblk);
1195 st->pktin->encrypted_len = st->packetlen;
1201 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, st->len + 4,
1202 st->incoming_sequence)) {
1203 bombout(("Incorrect MAC received on packet"));
1204 ssh_free_packet(st->pktin);
1208 st->pktin->sequence = st->incoming_sequence++;
1211 * Decompress packet payload.
1214 unsigned char *newpayload;
1217 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1218 st->pktin->data + 5, st->pktin->length - 5,
1219 &newpayload, &newlen)) {
1220 if (st->pktin->maxlen < newlen + 5) {
1221 st->pktin->maxlen = newlen + 5;
1222 st->pktin->data = sresize(st->pktin->data,
1223 st->pktin->maxlen + APIEXTRA,
1226 st->pktin->length = 5 + newlen;
1227 memcpy(st->pktin->data + 5, newpayload, newlen);
1232 st->pktin->savedpos = 6;
1233 st->pktin->body = st->pktin->data;
1234 st->pktin->type = st->pktin->data[5];
1237 * Log incoming packet, possibly omitting sensitive fields.
1241 struct logblank_t blank;
1242 if (ssh->cfg.logomitdata) {
1243 int do_blank = FALSE, blank_prefix = 0;
1244 /* "Session data" packets - omit the data field */
1245 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
1246 do_blank = TRUE; blank_prefix = 4;
1247 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1248 do_blank = TRUE; blank_prefix = 8;
1251 blank.offset = blank_prefix;
1252 blank.len = (st->pktin->length-6) - blank_prefix;
1253 blank.type = PKTLOG_OMIT;
1257 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1258 ssh2_pkt_type(ssh->pkt_ctx, st->pktin->type),
1259 st->pktin->data+6, st->pktin->length-6,
1263 crFinish(st->pktin);
1266 static void ssh1_pktout_size(struct Packet *pkt, int len)
1270 len += 5; /* type and CRC */
1271 pad = 8 - (len % 8);
1274 pkt->length = len - 5;
1275 if (pkt->maxlen < biglen) {
1276 pkt->maxlen = biglen;
1277 pkt->data = sresize(pkt->data, biglen + 4 + APIEXTRA, unsigned char);
1279 pkt->body = pkt->data + 4 + pad + 1;
1282 static struct Packet *s_wrpkt_start(int type, int len)
1284 struct Packet *pkt = ssh_new_packet();
1285 ssh1_pktout_size(pkt, len);
1287 /* Initialise log omission state */
1293 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt)
1299 * XXX various versions of SC (including 8.8.4) screw up the
1300 * register allocation in this function and use the same register
1301 * (D6) for len and as a temporary, with predictable results. The
1302 * following sledgehammer prevents this.
1308 pkt->body[-1] = pkt->type;
1311 log_packet(ssh->logctx, PKT_OUTGOING, pkt->type,
1312 ssh1_pkt_type(pkt->type),
1313 pkt->body, pkt->length,
1314 pkt->nblanks, pkt->blanks);
1315 sfree(pkt->blanks); pkt->blanks = NULL;
1318 if (ssh->v1_compressing) {
1319 unsigned char *compblk;
1321 zlib_compress_block(ssh->cs_comp_ctx,
1322 pkt->body - 1, pkt->length + 1,
1323 &compblk, &complen);
1324 ssh1_pktout_size(pkt, complen - 1);
1325 memcpy(pkt->body - 1, compblk, complen);
1329 len = pkt->length + 5; /* type and CRC */
1330 pad = 8 - (len % 8);
1333 for (i = 0; i < pad; i++)
1334 pkt->data[i + 4] = random_byte();
1335 crc = crc32_compute(pkt->data + 4, biglen - 4);
1336 PUT_32BIT(pkt->data + biglen, crc);
1337 PUT_32BIT(pkt->data, len);
1340 ssh->cipher->encrypt(ssh->v1_cipher_ctx, pkt->data + 4, biglen);
1345 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1348 len = s_wrpkt_prepare(ssh, pkt);
1349 backlog = sk_write(ssh->s, (char *)pkt->data, len);
1350 if (backlog > SSH_MAX_BACKLOG)
1351 ssh_throttle_all(ssh, 1, backlog);
1354 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1357 len = s_wrpkt_prepare(ssh, pkt);
1358 if (ssh->deferred_len + len > ssh->deferred_size) {
1359 ssh->deferred_size = ssh->deferred_len + len + 128;
1360 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1364 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
1365 ssh->deferred_len += len;
1369 * Construct a packet with the specified contents.
1371 static struct Packet *construct_packet(Ssh ssh, int pkttype,
1372 va_list ap1, va_list ap2)
1374 unsigned char *p, *argp, argchar;
1375 unsigned long argint;
1376 int pktlen, argtype, arglen;
1381 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1384 (void) va_arg(ap1, int);
1388 (void) va_arg(ap1, int);
1392 (void) va_arg(ap1, unsigned char *);
1393 arglen = va_arg(ap1, int);
1397 argp = va_arg(ap1, unsigned char *);
1398 arglen = strlen((char *)argp);
1399 pktlen += 4 + arglen;
1402 bn = va_arg(ap1, Bignum);
1403 pktlen += ssh1_bignum_length(bn);
1408 /* ignore this pass */
1415 pkt = s_wrpkt_start(pkttype, pktlen);
1418 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1419 int offset = p - pkt->body, len = 0;
1421 /* Actual fields in the packet */
1423 argint = va_arg(ap2, int);
1424 PUT_32BIT(p, argint);
1428 argchar = (unsigned char) va_arg(ap2, int);
1433 argp = va_arg(ap2, unsigned char *);
1434 arglen = va_arg(ap2, int);
1435 memcpy(p, argp, arglen);
1439 argp = va_arg(ap2, unsigned char *);
1440 arglen = strlen((char *)argp);
1441 PUT_32BIT(p, arglen);
1442 memcpy(p + 4, argp, arglen);
1446 bn = va_arg(ap2, Bignum);
1447 len = ssh1_write_bignum(p, bn);
1449 /* Tokens for modifications to packet logging */
1451 dont_log_password(ssh, pkt, PKTLOG_BLANK);
1454 dont_log_data(ssh, pkt, PKTLOG_OMIT);
1457 end_log_omission(ssh, pkt);
1461 /* Deal with logfile omission, if required. */
1462 if (len && (pkt->logmode != PKTLOG_EMIT)) {
1464 pkt->blanks = sresize(pkt->blanks, pkt->nblanks,
1466 pkt->blanks[pkt->nblanks-1].offset = offset;
1467 pkt->blanks[pkt->nblanks-1].len = len;
1468 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1475 static void send_packet(Ssh ssh, int pkttype, ...)
1479 va_start(ap1, pkttype);
1480 va_start(ap2, pkttype);
1481 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1485 ssh_free_packet(pkt);
1488 static void defer_packet(Ssh ssh, int pkttype, ...)
1492 va_start(ap1, pkttype);
1493 va_start(ap2, pkttype);
1494 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1497 s_wrpkt_defer(ssh, pkt);
1498 ssh_free_packet(pkt);
1501 static int ssh_versioncmp(char *a, char *b)
1504 unsigned long av, bv;
1506 av = strtoul(a, &ae, 10);
1507 bv = strtoul(b, &be, 10);
1509 return (av < bv ? -1 : +1);
1514 av = strtoul(ae, &ae, 10);
1515 bv = strtoul(be, &be, 10);
1517 return (av < bv ? -1 : +1);
1522 * Utility routines for putting an SSH-protocol `string' and
1523 * `uint32' into a SHA state.
1526 static void sha_string(SHA_State * s, void *str, int len)
1528 unsigned char lenblk[4];
1529 PUT_32BIT(lenblk, len);
1530 SHA_Bytes(s, lenblk, 4);
1531 SHA_Bytes(s, str, len);
1534 static void sha_uint32(SHA_State * s, unsigned i)
1536 unsigned char intblk[4];
1537 PUT_32BIT(intblk, i);
1538 SHA_Bytes(s, intblk, 4);
1542 * SSH2 packet construction functions.
1544 static void ssh2_pkt_ensure(struct Packet *pkt, int length)
1546 if (pkt->maxlen < length) {
1547 pkt->maxlen = length + 256;
1548 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
1551 static void ssh2_pkt_adddata(struct Packet *pkt, void *data, int len)
1553 if (pkt->logmode != PKTLOG_EMIT) {
1555 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1556 pkt->blanks[pkt->nblanks-1].offset = pkt->length - 6;
1557 pkt->blanks[pkt->nblanks-1].len = len;
1558 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1561 ssh2_pkt_ensure(pkt, pkt->length);
1562 memcpy(pkt->data + pkt->length - len, data, len);
1564 static void ssh2_pkt_addbyte(struct Packet *pkt, unsigned char byte)
1566 ssh2_pkt_adddata(pkt, &byte, 1);
1568 static struct Packet *ssh2_pkt_init(int pkt_type)
1570 struct Packet *pkt = ssh_new_packet();
1572 ssh2_pkt_addbyte(pkt, (unsigned char) pkt_type);
1575 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
1577 ssh2_pkt_adddata(pkt, &value, 1);
1579 static void ssh2_pkt_adduint32(struct Packet *pkt, unsigned long value)
1582 PUT_32BIT(x, value);
1583 ssh2_pkt_adddata(pkt, x, 4);
1585 static void ssh2_pkt_addstring_start(struct Packet *pkt)
1587 ssh2_pkt_adduint32(pkt, 0);
1588 pkt->savedpos = pkt->length;
1590 static void ssh2_pkt_addstring_str(struct Packet *pkt, char *data)
1592 ssh2_pkt_adddata(pkt, data, strlen(data));
1593 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1595 static void ssh2_pkt_addstring_data(struct Packet *pkt, char *data, int len)
1597 ssh2_pkt_adddata(pkt, data, len);
1598 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1600 static void ssh2_pkt_addstring(struct Packet *pkt, char *data)
1602 ssh2_pkt_addstring_start(pkt);
1603 ssh2_pkt_addstring_str(pkt, data);
1605 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1608 int i, n = (bignum_bitcount(b) + 7) / 8;
1609 p = snewn(n + 1, unsigned char);
1611 fatalbox("out of memory");
1613 for (i = 1; i <= n; i++)
1614 p[i] = bignum_byte(b, n - i);
1616 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1618 memmove(p, p + i, n + 1 - i);
1622 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
1626 p = ssh2_mpint_fmt(b, &len);
1627 ssh2_pkt_addstring_start(pkt);
1628 ssh2_pkt_addstring_data(pkt, (char *)p, len);
1633 * Construct an SSH2 final-form packet: compress it, encrypt it,
1634 * put the MAC on it. Final packet, ready to be sent, is stored in
1635 * pkt->data. Total length is returned.
1637 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
1639 int cipherblk, maclen, padding, i;
1642 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1643 ssh2_pkt_type(ssh->pkt_ctx, pkt->data[5]),
1644 pkt->data + 6, pkt->length - 6,
1645 pkt->nblanks, pkt->blanks);
1646 sfree(pkt->blanks); pkt->blanks = NULL;
1650 * Compress packet payload.
1653 unsigned char *newpayload;
1656 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1658 &newpayload, &newlen)) {
1660 ssh2_pkt_adddata(pkt, newpayload, newlen);
1666 * Add padding. At least four bytes, and must also bring total
1667 * length (minus MAC) up to a multiple of the block size.
1669 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1670 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1673 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
1674 maclen = ssh->csmac ? ssh->csmac->len : 0;
1675 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1676 pkt->data[4] = padding;
1677 for (i = 0; i < padding; i++)
1678 pkt->data[pkt->length + i] = random_byte();
1679 PUT_32BIT(pkt->data, pkt->length + padding - 4);
1681 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1682 pkt->length + padding,
1683 ssh->v2_outgoing_sequence);
1684 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1687 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1688 pkt->data, pkt->length + padding);
1690 pkt->encrypted_len = pkt->length + padding;
1692 /* Ready-to-send packet starts at pkt->data. We return length. */
1693 return pkt->length + padding + maclen;
1697 * Routines called from the main SSH code to send packets. There
1698 * are quite a few of these, because we have two separate
1699 * mechanisms for delaying the sending of packets:
1701 * - In order to send an IGNORE message and a password message in
1702 * a single fixed-length blob, we require the ability to
1703 * concatenate the encrypted forms of those two packets _into_ a
1704 * single blob and then pass it to our <network.h> transport
1705 * layer in one go. Hence, there's a deferment mechanism which
1706 * works after packet encryption.
1708 * - In order to avoid sending any connection-layer messages
1709 * during repeat key exchange, we have to queue up any such
1710 * outgoing messages _before_ they are encrypted (and in
1711 * particular before they're allocated sequence numbers), and
1712 * then send them once we've finished.
1714 * I call these mechanisms `defer' and `queue' respectively, so as
1715 * to distinguish them reasonably easily.
1717 * The functions send_noqueue() and defer_noqueue() free the packet
1718 * structure they are passed. Every outgoing packet goes through
1719 * precisely one of these functions in its life; packets passed to
1720 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
1721 * these or get queued, and then when the queue is later emptied
1722 * the packets are all passed to defer_noqueue().
1726 * Send an SSH2 packet immediately, without queuing or deferring.
1728 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
1732 len = ssh2_pkt_construct(ssh, pkt);
1733 backlog = sk_write(ssh->s, (char *)pkt->data, len);
1734 if (backlog > SSH_MAX_BACKLOG)
1735 ssh_throttle_all(ssh, 1, backlog);
1737 ssh->outgoing_data_size += pkt->encrypted_len;
1738 if (!ssh->kex_in_progress &&
1739 ssh->max_data_size != 0 &&
1740 ssh->outgoing_data_size > ssh->max_data_size)
1741 do_ssh2_transport(ssh, "Initiating key re-exchange "
1742 "(too much data sent)", -1, NULL);
1744 ssh_free_packet(pkt);
1748 * Defer an SSH2 packet.
1750 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt)
1752 int len = ssh2_pkt_construct(ssh, pkt);
1753 if (ssh->deferred_len + len > ssh->deferred_size) {
1754 ssh->deferred_size = ssh->deferred_len + len + 128;
1755 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1759 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
1760 ssh->deferred_len += len;
1761 ssh->deferred_data_size += pkt->encrypted_len;
1762 ssh_free_packet(pkt);
1766 * Queue an SSH2 packet.
1768 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
1770 assert(ssh->queueing);
1772 if (ssh->queuelen >= ssh->queuesize) {
1773 ssh->queuesize = ssh->queuelen + 32;
1774 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
1777 ssh->queue[ssh->queuelen++] = pkt;
1781 * Either queue or send a packet, depending on whether queueing is
1784 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
1787 ssh2_pkt_queue(ssh, pkt);
1789 ssh2_pkt_send_noqueue(ssh, pkt);
1793 * Either queue or defer a packet, depending on whether queueing is
1796 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
1799 ssh2_pkt_queue(ssh, pkt);
1801 ssh2_pkt_defer_noqueue(ssh, pkt);
1805 * Send the whole deferred data block constructed by
1806 * ssh2_pkt_defer() or SSH1's defer_packet().
1808 * The expected use of the defer mechanism is that you call
1809 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
1810 * not currently queueing, this simply sets up deferred_send_data
1811 * and then sends it. If we _are_ currently queueing, the calls to
1812 * ssh2_pkt_defer() put the deferred packets on to the queue
1813 * instead, and therefore ssh_pkt_defersend() has no deferred data
1814 * to send. Hence, there's no need to make it conditional on
1817 static void ssh_pkt_defersend(Ssh ssh)
1820 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1822 ssh->deferred_len = ssh->deferred_size = 0;
1823 sfree(ssh->deferred_send_data);
1824 ssh->deferred_send_data = NULL;
1825 if (backlog > SSH_MAX_BACKLOG)
1826 ssh_throttle_all(ssh, 1, backlog);
1828 ssh->outgoing_data_size += ssh->deferred_data_size;
1829 if (!ssh->kex_in_progress &&
1830 ssh->max_data_size != 0 &&
1831 ssh->outgoing_data_size > ssh->max_data_size)
1832 do_ssh2_transport(ssh, "Initiating key re-exchange "
1833 "(too much data sent)", -1, NULL);
1834 ssh->deferred_data_size = 0;
1838 * Send all queued SSH2 packets. We send them by means of
1839 * ssh2_pkt_defer_noqueue(), in case they included a pair of
1840 * packets that needed to be lumped together.
1842 static void ssh2_pkt_queuesend(Ssh ssh)
1846 assert(!ssh->queueing);
1848 for (i = 0; i < ssh->queuelen; i++)
1849 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i]);
1852 ssh_pkt_defersend(ssh);
1856 void bndebug(char *string, Bignum b)
1860 p = ssh2_mpint_fmt(b, &len);
1861 debug(("%s", string));
1862 for (i = 0; i < len; i++)
1863 debug((" %02x", p[i]));
1869 static void sha_mpint(SHA_State * s, Bignum b)
1873 p = ssh2_mpint_fmt(b, &len);
1874 sha_string(s, p, len);
1879 * Packet decode functions for both SSH1 and SSH2.
1881 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
1883 unsigned long value;
1884 if (pkt->length - pkt->savedpos < 4)
1885 return 0; /* arrgh, no way to decline (FIXME?) */
1886 value = GET_32BIT(pkt->body + pkt->savedpos);
1890 static int ssh2_pkt_getbool(struct Packet *pkt)
1892 unsigned long value;
1893 if (pkt->length - pkt->savedpos < 1)
1894 return 0; /* arrgh, no way to decline (FIXME?) */
1895 value = pkt->body[pkt->savedpos] != 0;
1899 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
1904 if (pkt->length - pkt->savedpos < 4)
1906 len = GET_32BIT(pkt->body + pkt->savedpos);
1911 if (pkt->length - pkt->savedpos < *length)
1913 *p = (char *)(pkt->body + pkt->savedpos);
1914 pkt->savedpos += *length;
1916 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
1918 if (pkt->length - pkt->savedpos < length)
1920 pkt->savedpos += length;
1921 return pkt->body + (pkt->savedpos - length);
1923 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
1924 unsigned char **keystr)
1928 j = makekey(pkt->body + pkt->savedpos,
1929 pkt->length - pkt->savedpos,
1936 assert(pkt->savedpos < pkt->length);
1940 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
1945 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
1946 pkt->length - pkt->savedpos, &b);
1954 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
1960 ssh_pkt_getstring(pkt, &p, &length);
1965 b = bignum_from_bytes((unsigned char *)p, length);
1970 * Helper function to add an SSH2 signature blob to a packet.
1971 * Expects to be shown the public key blob as well as the signature
1972 * blob. Normally works just like ssh2_pkt_addstring, but will
1973 * fiddle with the signature packet if necessary for
1974 * BUG_SSH2_RSA_PADDING.
1976 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
1977 void *pkblob_v, int pkblob_len,
1978 void *sigblob_v, int sigblob_len)
1980 unsigned char *pkblob = (unsigned char *)pkblob_v;
1981 unsigned char *sigblob = (unsigned char *)sigblob_v;
1983 /* dmemdump(pkblob, pkblob_len); */
1984 /* dmemdump(sigblob, sigblob_len); */
1987 * See if this is in fact an ssh-rsa signature and a buggy
1988 * server; otherwise we can just do this the easy way.
1990 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1991 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1992 int pos, len, siglen;
1995 * Find the byte length of the modulus.
1998 pos = 4+7; /* skip over "ssh-rsa" */
1999 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
2000 len = GET_32BIT(pkblob+pos); /* find length of modulus */
2001 pos += 4; /* find modulus itself */
2002 while (len > 0 && pkblob[pos] == 0)
2004 /* debug(("modulus length is %d\n", len)); */
2007 * Now find the signature integer.
2009 pos = 4+7; /* skip over "ssh-rsa" */
2010 siglen = GET_32BIT(sigblob+pos);
2011 /* debug(("signature length is %d\n", siglen)); */
2013 if (len != siglen) {
2014 unsigned char newlen[4];
2015 ssh2_pkt_addstring_start(pkt);
2016 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2017 /* dmemdump(sigblob, pos); */
2018 pos += 4; /* point to start of actual sig */
2019 PUT_32BIT(newlen, len);
2020 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2021 /* dmemdump(newlen, 4); */
2023 while (len-- > siglen) {
2024 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2025 /* dmemdump(newlen, 1); */
2027 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2028 /* dmemdump(sigblob+pos, siglen); */
2032 /* Otherwise fall through and do it the easy way. */
2035 ssh2_pkt_addstring_start(pkt);
2036 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2040 * Examine the remote side's version string and compare it against
2041 * a list of known buggy implementations.
2043 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2045 char *imp; /* pointer to implementation part */
2047 imp += strcspn(imp, "-");
2049 imp += strcspn(imp, "-");
2052 ssh->remote_bugs = 0;
2054 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
2055 (ssh->cfg.sshbug_ignore1 == AUTO &&
2056 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2057 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2058 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2059 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2061 * These versions don't support SSH1_MSG_IGNORE, so we have
2062 * to use a different defence against password length
2065 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2066 logevent("We believe remote version has SSH1 ignore bug");
2069 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
2070 (ssh->cfg.sshbug_plainpw1 == AUTO &&
2071 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2073 * These versions need a plain password sent; they can't
2074 * handle having a null and a random length of data after
2077 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2078 logevent("We believe remote version needs a plain SSH1 password");
2081 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
2082 (ssh->cfg.sshbug_rsa1 == AUTO &&
2083 (!strcmp(imp, "Cisco-1.25")))) {
2085 * These versions apparently have no clue whatever about
2086 * RSA authentication and will panic and die if they see
2087 * an AUTH_RSA message.
2089 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2090 logevent("We believe remote version can't handle RSA authentication");
2093 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2094 (ssh->cfg.sshbug_hmac2 == AUTO &&
2095 !wc_match("* VShell", imp) &&
2096 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2097 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2098 wc_match("2.1 *", imp)))) {
2100 * These versions have the HMAC bug.
2102 ssh->remote_bugs |= BUG_SSH2_HMAC;
2103 logevent("We believe remote version has SSH2 HMAC bug");
2106 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2107 (ssh->cfg.sshbug_derivekey2 == AUTO &&
2108 !wc_match("* VShell", imp) &&
2109 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2111 * These versions have the key-derivation bug (failing to
2112 * include the literal shared secret in the hashes that
2113 * generate the keys).
2115 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2116 logevent("We believe remote version has SSH2 key-derivation bug");
2119 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2120 (ssh->cfg.sshbug_rsapad2 == AUTO &&
2121 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2122 wc_match("OpenSSH_3.[0-2]*", imp)))) {
2124 * These versions have the SSH2 RSA padding bug.
2126 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2127 logevent("We believe remote version has SSH2 RSA padding bug");
2130 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2131 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2132 wc_match("OpenSSH_2.[0-2]*", imp))) {
2134 * These versions have the SSH2 session-ID bug in
2135 * public-key authentication.
2137 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2138 logevent("We believe remote version has SSH2 public-key-session-ID bug");
2143 * The `software version' part of an SSH version string is required
2144 * to contain no spaces or minus signs.
2146 static void ssh_fix_verstring(char *str)
2148 /* Eat "SSH-<protoversion>-". */
2149 assert(*str == 'S'); str++;
2150 assert(*str == 'S'); str++;
2151 assert(*str == 'H'); str++;
2152 assert(*str == '-'); str++;
2153 while (*str && *str != '-') str++;
2154 assert(*str == '-'); str++;
2156 /* Convert minus signs and spaces in the remaining string into
2159 if (*str == '-' || *str == ' ')
2165 static int do_ssh_init(Ssh ssh, unsigned char c)
2167 struct do_ssh_init_state {
2175 crState(do_ssh_init_state);
2177 crBegin(ssh->do_ssh_init_crstate);
2179 /* Search for the string "SSH-" in the input. */
2182 static const int transS[] = { 1, 2, 2, 1 };
2183 static const int transH[] = { 0, 0, 3, 0 };
2184 static const int transminus[] = { 0, 0, 0, -1 };
2186 s->i = transS[s->i];
2188 s->i = transH[s->i];
2190 s->i = transminus[s->i];
2195 crReturn(1); /* get another character */
2199 s->vstring = snewn(s->vstrsize, char);
2200 strcpy(s->vstring, "SSH-");
2204 crReturn(1); /* get another char */
2205 if (s->vslen >= s->vstrsize - 1) {
2207 s->vstring = sresize(s->vstring, s->vstrsize, char);
2209 s->vstring[s->vslen++] = c;
2212 s->version[s->i] = '\0';
2214 } else if (s->i < sizeof(s->version) - 1)
2215 s->version[s->i++] = c;
2216 } else if (c == '\012')
2220 ssh->agentfwd_enabled = FALSE;
2221 ssh->rdpkt2_state.incoming_sequence = 0;
2223 s->vstring[s->vslen] = 0;
2224 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2227 vlog = snewn(20 + s->vslen, char);
2228 sprintf(vlog, "Server version: %s", s->vstring);
2232 ssh_detect_bugs(ssh, s->vstring);
2235 * Decide which SSH protocol version to support.
2238 /* Anything strictly below "2.0" means protocol 1 is supported. */
2239 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2240 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2241 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2243 if (ssh->cfg.sshprot == 0 && !s->proto1) {
2244 bombout(("SSH protocol version 1 required by user but not provided by server"));
2247 if (ssh->cfg.sshprot == 3 && !s->proto2) {
2248 bombout(("SSH protocol version 2 required by user but not provided by server"));
2255 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2257 * Construct a v2 version string.
2259 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2263 * Construct a v1 version string.
2265 verstring = dupprintf("SSH-%s-%s\012",
2266 (ssh_versioncmp(s->version, "1.5") <= 0 ?
2267 s->version : "1.5"),
2272 ssh_fix_verstring(verstring);
2274 if (ssh->version == 2) {
2276 * Hash our version string and their version string.
2278 SHA_Init(&ssh->exhashbase);
2279 sha_string(&ssh->exhashbase, verstring,
2280 strcspn(verstring, "\015\012"));
2281 sha_string(&ssh->exhashbase, s->vstring,
2282 strcspn(s->vstring, "\015\012"));
2285 * Initialise SSHv2 protocol.
2287 ssh->protocol = ssh2_protocol;
2288 ssh2_protocol_setup(ssh);
2289 ssh->s_rdpkt = ssh2_rdpkt;
2292 * Initialise SSHv1 protocol.
2294 ssh->protocol = ssh1_protocol;
2295 ssh1_protocol_setup(ssh);
2296 ssh->s_rdpkt = ssh1_rdpkt;
2298 logeventf(ssh, "We claim version: %.*s",
2299 strcspn(verstring, "\015\012"), verstring);
2300 sk_write(ssh->s, verstring, strlen(verstring));
2304 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2306 update_specials_menu(ssh->frontend);
2307 ssh->state = SSH_STATE_BEFORE_SIZE;
2308 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
2315 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2317 crBegin(ssh->ssh_gotdata_crstate);
2320 * To begin with, feed the characters one by one to the
2321 * protocol initialisation / selection function do_ssh_init().
2322 * When that returns 0, we're done with the initial greeting
2323 * exchange and can move on to packet discipline.
2326 int ret; /* need not be kept across crReturn */
2328 crReturnV; /* more data please */
2329 ret = do_ssh_init(ssh, *data);
2337 * We emerge from that loop when the initial negotiation is
2338 * over and we have selected an s_rdpkt function. Now pass
2339 * everything to s_rdpkt, and then pass the resulting packets
2340 * to the proper protocol handler.
2345 while (datalen > 0) {
2346 struct Packet *pktin = ssh->s_rdpkt(ssh, &data, &datalen);
2348 ssh->protocol(ssh, NULL, 0, pktin);
2349 ssh_free_packet(pktin);
2351 if (ssh->state == SSH_STATE_CLOSED)
2359 static void ssh_do_close(Ssh ssh)
2362 struct ssh_channel *c;
2364 ssh->state = SSH_STATE_CLOSED;
2368 notify_remote_exit(ssh->frontend);
2371 * Now we must shut down any port and X forwardings going
2372 * through this connection.
2374 if (ssh->channels) {
2375 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2378 x11_close(c->u.x11.s);
2381 pfd_close(c->u.pfd.s);
2384 del234(ssh->channels, c);
2385 if (ssh->version == 2)
2386 bufchain_clear(&c->v.v2.outbuffer);
2392 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2395 Ssh ssh = (Ssh) plug;
2398 /* A socket error has occurred. */
2399 logevent(error_msg);
2400 connection_fatal(ssh->frontend, "%s", error_msg);
2402 /* Otherwise, the remote side closed the connection normally. */
2407 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2409 Ssh ssh = (Ssh) plug;
2410 ssh_gotdata(ssh, (unsigned char *)data, len);
2411 if (ssh->state == SSH_STATE_CLOSED) {
2418 static void ssh_sent(Plug plug, int bufsize)
2420 Ssh ssh = (Ssh) plug;
2422 * If the send backlog on the SSH socket itself clears, we
2423 * should unthrottle the whole world if it was throttled.
2425 if (bufsize < SSH_MAX_BACKLOG)
2426 ssh_throttle_all(ssh, 0, bufsize);
2430 * Connect to specified host and port.
2431 * Returns an error message, or NULL on success.
2432 * Also places the canonical host name into `realhost'. It must be
2433 * freed by the caller.
2435 static const char *connect_to_host(Ssh ssh, char *host, int port,
2436 char **realhost, int nodelay, int keepalive)
2438 static const struct plug_function_table fn_table = {
2448 ssh->savedhost = snewn(1 + strlen(host), char);
2449 if (!ssh->savedhost)
2450 fatalbox("Out of memory");
2451 strcpy(ssh->savedhost, host);
2454 port = 22; /* default ssh port */
2455 ssh->savedport = port;
2460 logeventf(ssh, "Looking up host \"%s\"%s", host,
2461 (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
2462 (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
2463 addr = name_lookup(host, port, realhost, &ssh->cfg,
2464 ssh->cfg.addressfamily);
2465 if ((err = sk_addr_error(addr)) != NULL) {
2475 sk_getaddr(addr, addrbuf, 100);
2476 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
2478 ssh->fn = &fn_table;
2479 ssh->s = new_connection(addr, *realhost, port,
2480 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
2481 if ((err = sk_socket_error(ssh->s)) != NULL) {
2483 notify_remote_exit(ssh->frontend);
2491 * Throttle or unthrottle the SSH connection.
2493 static void ssh1_throttle(Ssh ssh, int adjust)
2495 int old_count = ssh->v1_throttle_count;
2496 ssh->v1_throttle_count += adjust;
2497 assert(ssh->v1_throttle_count >= 0);
2498 if (ssh->v1_throttle_count && !old_count) {
2499 sk_set_frozen(ssh->s, 1);
2500 } else if (!ssh->v1_throttle_count && old_count) {
2501 sk_set_frozen(ssh->s, 0);
2506 * Throttle or unthrottle _all_ local data streams (for when sends
2507 * on the SSH connection itself back up).
2509 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2512 struct ssh_channel *c;
2514 if (enable == ssh->throttled_all)
2516 ssh->throttled_all = enable;
2517 ssh->overall_bufsize = bufsize;
2520 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2522 case CHAN_MAINSESSION:
2524 * This is treated separately, outside the switch.
2528 x11_override_throttle(c->u.x11.s, enable);
2531 /* Agent channels require no buffer management. */
2534 pfd_override_throttle(c->u.pfd.s, enable);
2541 * Username and password input, abstracted off into routines
2542 * reusable in several places - even between SSH1 and SSH2.
2545 /* Set up a username or password input loop on a given buffer. */
2546 static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2548 ssh->userpass_input_buffer = buffer;
2549 ssh->userpass_input_buflen = buflen;
2550 ssh->userpass_input_bufpos = 0;
2551 ssh->userpass_input_echo = echo;
2555 * Process some terminal data in the course of username/password
2556 * input. Returns >0 for success (line of input returned in
2557 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2558 * for inconclusive (keep waiting for more input please).
2560 static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2565 switch (c = *in++) {
2568 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2569 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2574 if (ssh->userpass_input_bufpos > 0) {
2575 if (ssh->userpass_input_echo)
2576 c_write_str(ssh, "\b \b");
2577 ssh->userpass_input_bufpos--;
2582 while (ssh->userpass_input_bufpos > 0) {
2583 if (ssh->userpass_input_echo)
2584 c_write_str(ssh, "\b \b");
2585 ssh->userpass_input_bufpos--;
2594 * This simplistic check for printability is disabled
2595 * when we're doing password input, because some people
2596 * have control characters in their passwords.o
2598 if ((!ssh->userpass_input_echo ||
2599 (c >= ' ' && c <= '~') ||
2600 ((unsigned char) c >= 160))
2601 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2602 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2603 if (ssh->userpass_input_echo)
2604 c_write(ssh, &c, 1);
2612 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
2614 Ssh ssh = (Ssh) sshv;
2616 ssh->agent_response = reply;
2617 ssh->agent_response_len = replylen;
2619 if (ssh->version == 1)
2620 do_ssh1_login(ssh, NULL, -1, NULL);
2622 do_ssh2_authconn(ssh, NULL, -1, NULL);
2625 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
2627 struct ssh_channel *c = (struct ssh_channel *)cv;
2629 void *sentreply = reply;
2632 /* Fake SSH_AGENT_FAILURE. */
2633 sentreply = "\0\0\0\1\5";
2636 if (ssh->version == 2) {
2637 ssh2_add_channel_data(c, sentreply, replylen);
2640 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2641 PKT_INT, c->remoteid,
2644 PKT_DATA, sentreply, replylen,
2653 * Handle the key exchange and user authentication phases.
2655 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2656 struct Packet *pktin)
2659 unsigned char cookie[8], *ptr;
2660 struct RSAKey servkey, hostkey;
2661 struct MD5Context md5c;
2662 struct do_ssh1_login_state {
2664 unsigned char *rsabuf, *keystr1, *keystr2;
2665 unsigned long supported_ciphers_mask, supported_auths_mask;
2666 int tried_publickey, tried_agent;
2667 int tis_auth_refused, ccard_auth_refused;
2668 unsigned char session_id[16];
2671 void *publickey_blob;
2672 int publickey_bloblen;
2678 unsigned char request[5], *response, *p;
2687 crState(do_ssh1_login_state);
2689 crBegin(ssh->do_ssh1_login_crstate);
2694 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
2695 bombout(("Public key packet not received"));
2699 logevent("Received public keys");
2701 ptr = ssh_pkt_getdata(pktin, 8);
2703 bombout(("SSH1 public key packet stopped before random cookie"));
2706 memcpy(cookie, ptr, 8);
2708 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2709 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
2710 bombout(("Failed to read SSH1 public keys from public key packet"));
2715 * Log the host key fingerprint.
2719 logevent("Host key fingerprint is:");
2720 strcpy(logmsg, " ");
2721 hostkey.comment = NULL;
2722 rsa_fingerprint(logmsg + strlen(logmsg),
2723 sizeof(logmsg) - strlen(logmsg), &hostkey);
2727 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2728 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2729 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
2731 ssh->v1_local_protoflags =
2732 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2733 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2736 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2737 MD5Update(&md5c, s->keystr1, servkey.bytes);
2738 MD5Update(&md5c, cookie, 8);
2739 MD5Final(s->session_id, &md5c);
2741 for (i = 0; i < 32; i++)
2742 ssh->session_key[i] = random_byte();
2745 * Verify that the `bits' and `bytes' parameters match.
2747 if (hostkey.bits > hostkey.bytes * 8 ||
2748 servkey.bits > servkey.bytes * 8) {
2749 bombout(("SSH1 public keys were badly formatted"));
2753 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2755 s->rsabuf = snewn(s->len, unsigned char);
2757 fatalbox("Out of memory");
2760 * Verify the host key.
2764 * First format the key into a string.
2766 int len = rsastr_len(&hostkey);
2767 char fingerprint[100];
2768 char *keystr = snewn(len, char);
2770 fatalbox("Out of memory");
2771 rsastr_fmt(keystr, &hostkey);
2772 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2773 verify_ssh_host_key(ssh->frontend,
2774 ssh->savedhost, ssh->savedport, "rsa", keystr,
2779 for (i = 0; i < 32; i++) {
2780 s->rsabuf[i] = ssh->session_key[i];
2782 s->rsabuf[i] ^= s->session_id[i];
2785 if (hostkey.bytes > servkey.bytes) {
2786 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2788 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2790 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
2792 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2795 bombout(("SSH1 public key encryptions failed due to bad formatting"));
2799 logevent("Encrypted session key");
2802 int cipher_chosen = 0, warn = 0;
2803 char *cipher_string = NULL;
2805 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2806 int next_cipher = ssh->cfg.ssh_cipherlist[i];
2807 if (next_cipher == CIPHER_WARN) {
2808 /* If/when we choose a cipher, warn about it */
2810 } else if (next_cipher == CIPHER_AES) {
2811 /* XXX Probably don't need to mention this. */
2812 logevent("AES not supported in SSH1, skipping");
2814 switch (next_cipher) {
2815 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
2816 cipher_string = "3DES"; break;
2817 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
2818 cipher_string = "Blowfish"; break;
2819 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
2820 cipher_string = "single-DES"; break;
2822 if (s->supported_ciphers_mask & (1 << s->cipher_type))
2826 if (!cipher_chosen) {
2827 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2828 bombout(("Server violates SSH 1 protocol by not "
2829 "supporting 3DES encryption"));
2831 /* shouldn't happen */
2832 bombout(("No supported ciphers found"));
2836 /* Warn about chosen cipher if necessary. */
2838 sk_set_frozen(ssh->s, 1);
2839 askalg(ssh->frontend, "cipher", cipher_string);
2840 sk_set_frozen(ssh->s, 0);
2844 switch (s->cipher_type) {
2845 case SSH_CIPHER_3DES:
2846 logevent("Using 3DES encryption");
2848 case SSH_CIPHER_DES:
2849 logevent("Using single-DES encryption");
2851 case SSH_CIPHER_BLOWFISH:
2852 logevent("Using Blowfish encryption");
2856 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2857 PKT_CHAR, s->cipher_type,
2858 PKT_DATA, cookie, 8,
2859 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2860 PKT_DATA, s->rsabuf, s->len,
2861 PKT_INT, ssh->v1_local_protoflags, PKT_END);
2863 logevent("Trying to enable encryption...");
2867 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2868 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2870 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2871 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
2872 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
2874 ssh->crcda_ctx = crcda_make_context();
2875 logevent("Installing CRC compensation attack detector");
2877 if (servkey.modulus) {
2878 sfree(servkey.modulus);
2879 servkey.modulus = NULL;
2881 if (servkey.exponent) {
2882 sfree(servkey.exponent);
2883 servkey.exponent = NULL;
2885 if (hostkey.modulus) {
2886 sfree(hostkey.modulus);
2887 hostkey.modulus = NULL;
2889 if (hostkey.exponent) {
2890 sfree(hostkey.exponent);
2891 hostkey.exponent = NULL;
2895 if (pktin->type != SSH1_SMSG_SUCCESS) {
2896 bombout(("Encryption not successfully enabled"));
2900 logevent("Successfully started encryption");
2904 if (!*ssh->cfg.username) {
2905 if (ssh_get_line && !ssh_getline_pw_only) {
2906 if (!ssh_get_line("login as: ",
2907 s->username, sizeof(s->username), FALSE)) {
2909 * get_line failed to get a username.
2912 logevent("No username provided. Abandoning session.");
2913 ssh_closing((Plug)ssh, NULL, 0, 0);
2917 int ret; /* need not be kept over crReturn */
2918 c_write_str(ssh, "login as: ");
2921 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
2923 crWaitUntil(!pktin);
2924 ret = process_userpass_input(ssh, in, inlen);
2928 c_write_str(ssh, "\r\n");
2931 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
2932 s->username[sizeof(s->username)-1] = '\0';
2935 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
2937 char userlog[22 + sizeof(s->username)];
2938 sprintf(userlog, "Sent username \"%s\"", s->username);
2940 if (flags & FLAG_INTERACTIVE &&
2941 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2942 strcat(userlog, "\r\n");
2943 c_write_str(ssh, userlog);
2950 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
2951 /* We must not attempt PK auth. Pretend we've already tried it. */
2952 s->tried_publickey = s->tried_agent = 1;
2954 s->tried_publickey = s->tried_agent = 0;
2956 s->tis_auth_refused = s->ccard_auth_refused = 0;
2957 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
2958 if (!filename_is_null(ssh->cfg.keyfile)) {
2959 if (!rsakey_pubblob(&ssh->cfg.keyfile,
2960 &s->publickey_blob, &s->publickey_bloblen, NULL))
2961 s->publickey_blob = NULL;
2963 s->publickey_blob = NULL;
2965 while (pktin->type == SSH1_SMSG_FAILURE) {
2966 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2968 if (agent_exists() && !s->tried_agent) {
2970 * Attempt RSA authentication using Pageant.
2976 logevent("Pageant is running. Requesting keys.");
2978 /* Request the keys held by the agent. */
2979 PUT_32BIT(s->request, 1);
2980 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2981 if (!agent_query(s->request, 5, &r, &s->responselen,
2982 ssh_agent_callback, ssh)) {
2986 bombout(("Unexpected data from server while waiting"
2987 " for agent response"));
2990 } while (pktin || inlen > 0);
2991 r = ssh->agent_response;
2992 s->responselen = ssh->agent_response_len;
2994 s->response = (unsigned char *) r;
2995 if (s->response && s->responselen >= 5 &&
2996 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2997 s->p = s->response + 5;
2998 s->nkeys = GET_32BIT(s->p);
3002 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
3005 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
3008 sprintf(buf, "Trying Pageant key #%d", s->keyi);
3011 if (s->publickey_blob &&
3012 !memcmp(s->p, s->publickey_blob,
3013 s->publickey_bloblen)) {
3014 logevent("This key matches configured key file");
3015 s->tried_publickey = 1;
3020 do { /* do while (0) to make breaking easy */
3021 n = ssh1_read_bignum
3022 (s->p, s->responselen-(s->p-s->response),
3027 n = ssh1_read_bignum
3028 (s->p, s->responselen-(s->p-s->response),
3033 if (s->responselen - (s->p-s->response) < 4)
3035 s->commentlen = GET_32BIT(s->p);
3037 if (s->responselen - (s->p-s->response) <
3040 s->commentp = (char *)s->p;
3041 s->p += s->commentlen;
3045 logevent("Pageant key list packet was truncated");
3049 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3050 PKT_BIGNUM, s->key.modulus, PKT_END);
3052 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3053 logevent("Key refused");
3056 logevent("Received RSA challenge");
3057 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3058 bombout(("Server's RSA challenge was badly formatted"));
3063 char *agentreq, *q, *ret;
3066 len = 1 + 4; /* message type, bit count */
3067 len += ssh1_bignum_length(s->key.exponent);
3068 len += ssh1_bignum_length(s->key.modulus);
3069 len += ssh1_bignum_length(s->challenge);
3070 len += 16; /* session id */
3071 len += 4; /* response format */
3072 agentreq = snewn(4 + len, char);
3073 PUT_32BIT(agentreq, len);
3075 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
3076 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
3078 q += ssh1_write_bignum(q, s->key.exponent);
3079 q += ssh1_write_bignum(q, s->key.modulus);
3080 q += ssh1_write_bignum(q, s->challenge);
3081 memcpy(q, s->session_id, 16);
3083 PUT_32BIT(q, 1); /* response format */
3084 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3085 ssh_agent_callback, ssh)) {
3090 bombout(("Unexpected data from server"
3091 " while waiting for agent"
3095 } while (pktin || inlen > 0);
3096 vret = ssh->agent_response;
3097 retlen = ssh->agent_response_len;
3102 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3103 logevent("Sending Pageant's response");
3104 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3105 PKT_DATA, ret + 5, 16,
3109 if (pktin->type == SSH1_SMSG_SUCCESS) {
3111 ("Pageant's response accepted");
3112 if (flags & FLAG_VERBOSE) {
3113 c_write_str(ssh, "Authenticated using"
3115 c_write(ssh, s->commentp,
3117 c_write_str(ssh, "\" from agent\r\n");
3122 ("Pageant's response not accepted");
3125 ("Pageant failed to answer challenge");
3129 logevent("No reply received from Pageant");
3132 freebn(s->key.exponent);
3133 freebn(s->key.modulus);
3134 freebn(s->challenge);
3143 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
3144 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
3146 if (ssh->cfg.try_tis_auth &&
3147 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3148 !s->tis_auth_refused) {
3149 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
3150 logevent("Requested TIS authentication");
3151 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
3153 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
3154 logevent("TIS authentication declined");
3155 if (flags & FLAG_INTERACTIVE)
3156 c_write_str(ssh, "TIS authentication refused.\r\n");
3157 s->tis_auth_refused = 1;
3163 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3165 bombout(("TIS challenge packet was badly formed"));
3168 logevent("Received TIS challenge");
3169 if (challengelen > sizeof(s->prompt) - 1)
3170 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3171 memcpy(s->prompt, challenge, challengelen);
3172 /* Prompt heuristic comes from OpenSSH */
3173 strncpy(s->prompt + challengelen,
3174 memchr(s->prompt, '\n', challengelen) ?
3175 "": "\r\nResponse: ",
3176 (sizeof s->prompt) - challengelen);
3177 s->prompt[(sizeof s->prompt) - 1] = '\0';
3180 if (ssh->cfg.try_tis_auth &&
3181 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3182 !s->ccard_auth_refused) {
3183 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
3184 logevent("Requested CryptoCard authentication");
3185 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
3187 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
3188 logevent("CryptoCard authentication declined");
3189 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3190 s->ccard_auth_refused = 1;
3196 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3198 bombout(("CryptoCard challenge packet was badly formed"));
3201 logevent("Received CryptoCard challenge");
3202 if (challengelen > sizeof(s->prompt) - 1)
3203 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3204 memcpy(s->prompt, challenge, challengelen);
3205 strncpy(s->prompt + challengelen,
3206 memchr(s->prompt, '\n', challengelen) ?
3207 "" : "\r\nResponse: ",
3208 sizeof(s->prompt) - challengelen);
3209 s->prompt[sizeof(s->prompt) - 1] = '\0';
3212 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3213 sprintf(s->prompt, "%.90s@%.90s's password: ",
3214 s->username, ssh->savedhost);
3216 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3217 char *comment = NULL;
3220 if (flags & FLAG_VERBOSE)
3221 c_write_str(ssh, "Trying public key authentication.\r\n");
3222 logeventf(ssh, "Trying public key \"%s\"",
3223 filename_to_str(&ssh->cfg.keyfile));
3224 type = key_type(&ssh->cfg.keyfile);
3225 if (type != SSH_KEYTYPE_SSH1) {
3226 sprintf(msgbuf, "Key is of wrong type (%s)",
3227 key_type_to_str(type));
3229 c_write_str(ssh, msgbuf);
3230 c_write_str(ssh, "\r\n");
3231 s->tried_publickey = 1;
3234 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
3235 if (flags & FLAG_VERBOSE)
3236 c_write_str(ssh, "No passphrase required.\r\n");
3239 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
3244 * Show password prompt, having first obtained it via a TIS
3245 * or CryptoCard exchange if we're doing TIS or CryptoCard
3249 if (!ssh_get_line(s->prompt, s->password,
3250 sizeof(s->password), TRUE)) {
3252 * get_line failed to get a password (for example
3253 * because one was supplied on the command line
3254 * which has already failed to work). Terminate.
3256 send_packet(ssh, SSH1_MSG_DISCONNECT,
3257 PKT_STR, "No more passwords available to try",
3259 logevent("Unable to authenticate");
3260 connection_fatal(ssh->frontend, "Unable to authenticate");
3261 ssh_closing((Plug)ssh, NULL, 0, 0);
3265 /* Prompt may have come from server. We've munged it a bit, so
3266 * we know it to be zero-terminated at least once. */
3267 int ret; /* need not be saved over crReturn */
3268 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3271 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
3273 crWaitUntil(!pktin);
3274 ret = process_userpass_input(ssh, in, inlen);
3278 c_write_str(ssh, "\r\n");
3282 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3284 * Try public key authentication with the specified
3287 s->tried_publickey = 1;
3290 const char *error = NULL;
3291 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3294 c_write_str(ssh, "Couldn't load private key from ");
3295 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
3296 c_write_str(ssh, " (");
3297 c_write_str(ssh, error);
3298 c_write_str(ssh, ").\r\n");
3299 continue; /* go and try password */
3302 c_write_str(ssh, "Wrong passphrase.\r\n");
3303 s->tried_publickey = 0;
3304 continue; /* try again */
3309 * Send a public key attempt.
3311 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3312 PKT_BIGNUM, s->key.modulus, PKT_END);
3315 if (pktin->type == SSH1_SMSG_FAILURE) {
3316 c_write_str(ssh, "Server refused our public key.\r\n");
3317 continue; /* go and try password */
3319 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3320 bombout(("Bizarre response to offer of public key"));
3326 unsigned char buffer[32];
3327 Bignum challenge, response;
3329 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3330 bombout(("Server's RSA challenge was badly formatted"));
3333 response = rsadecrypt(challenge, &s->key);
3334 freebn(s->key.private_exponent);/* burn the evidence */
3336 for (i = 0; i < 32; i++) {
3337 buffer[i] = bignum_byte(response, 31 - i);
3341 MD5Update(&md5c, buffer, 32);
3342 MD5Update(&md5c, s->session_id, 16);
3343 MD5Final(buffer, &md5c);
3345 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3346 PKT_DATA, buffer, 16, PKT_END);
3353 if (pktin->type == SSH1_SMSG_FAILURE) {
3354 if (flags & FLAG_VERBOSE)
3355 c_write_str(ssh, "Failed to authenticate with"
3356 " our public key.\r\n");
3357 continue; /* go and try password */
3358 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3359 bombout(("Bizarre response to RSA authentication response"));
3363 break; /* we're through! */
3365 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3367 * Defence against traffic analysis: we send a
3368 * whole bunch of packets containing strings of
3369 * different lengths. One of these strings is the
3370 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3371 * The others are all random data in
3372 * SSH1_MSG_IGNORE packets. This way a passive
3373 * listener can't tell which is the password, and
3374 * hence can't deduce the password length.
3376 * Anybody with a password length greater than 16
3377 * bytes is going to have enough entropy in their
3378 * password that a listener won't find it _that_
3379 * much help to know how long it is. So what we'll
3382 * - if password length < 16, we send 15 packets
3383 * containing string lengths 1 through 15
3385 * - otherwise, we let N be the nearest multiple
3386 * of 8 below the password length, and send 8
3387 * packets containing string lengths N through
3388 * N+7. This won't obscure the order of
3389 * magnitude of the password length, but it will
3390 * introduce a bit of extra uncertainty.
3392 * A few servers (the old 1.2.18 through 1.2.22)
3393 * can't deal with SSH1_MSG_IGNORE. For these
3394 * servers, we need an alternative defence. We make
3395 * use of the fact that the password is interpreted
3396 * as a C string: so we can append a NUL, then some
3399 * One server (a Cisco one) can deal with neither
3400 * SSH1_MSG_IGNORE _nor_ a padded password string.
3401 * For this server we are left with no defences
3402 * against password length sniffing.
3404 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
3406 * The server can deal with SSH1_MSG_IGNORE, so
3407 * we can use the primary defence.
3409 int bottom, top, pwlen, i;
3412 pwlen = strlen(s->password);
3414 bottom = 0; /* zero length passwords are OK! :-) */
3417 bottom = pwlen & ~7;
3421 assert(pwlen >= bottom && pwlen <= top);
3423 randomstr = snewn(top + 1, char);
3425 for (i = bottom; i <= top; i++) {
3427 defer_packet(ssh, s->pwpkt_type,
3428 PKTT_PASSWORD, PKT_STR, s->password,
3429 PKTT_OTHER, PKT_END);
3431 for (j = 0; j < i; j++) {
3433 randomstr[j] = random_byte();
3434 } while (randomstr[j] == '\0');
3436 randomstr[i] = '\0';
3437 defer_packet(ssh, SSH1_MSG_IGNORE,
3438 PKT_STR, randomstr, PKT_END);
3441 logevent("Sending password with camouflage packets");
3442 ssh_pkt_defersend(ssh);
3445 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3447 * The server can't deal with SSH1_MSG_IGNORE
3448 * but can deal with padded passwords, so we
3449 * can use the secondary defence.
3455 len = strlen(s->password);
3456 if (len < sizeof(string)) {
3458 strcpy(string, s->password);
3459 len++; /* cover the zero byte */
3460 while (len < sizeof(string)) {
3461 string[len++] = (char) random_byte();
3466 logevent("Sending length-padded password");
3467 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3468 PKT_INT, len, PKT_DATA, ss, len,
3469 PKTT_OTHER, PKT_END);
3472 * The server has _both_
3473 * BUG_CHOKES_ON_SSH1_IGNORE and
3474 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3475 * therefore nothing we can do.
3478 len = strlen(s->password);
3479 logevent("Sending unpadded password");
3480 send_packet(ssh, s->pwpkt_type,
3481 PKTT_PASSWORD, PKT_INT, len,
3482 PKT_DATA, s->password, len,
3483 PKTT_OTHER, PKT_END);
3486 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3487 PKT_STR, s->password, PKTT_OTHER, PKT_END);
3490 logevent("Sent password");
3491 memset(s->password, 0, strlen(s->password));
3493 if (pktin->type == SSH1_SMSG_FAILURE) {
3494 if (flags & FLAG_VERBOSE)
3495 c_write_str(ssh, "Access denied\r\n");
3496 logevent("Authentication refused");
3497 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3498 bombout(("Strange packet received, type %d", pktin->type));
3503 logevent("Authentication successful");
3508 void sshfwd_close(struct ssh_channel *c)
3512 if (ssh->state != SSH_STATE_SESSION) {
3513 assert(ssh->state == SSH_STATE_CLOSED);
3517 if (c && !c->closes) {
3519 * If the channel's remoteid is -1, we have sent
3520 * CHANNEL_OPEN for this channel, but it hasn't even been
3521 * acknowledged by the server. So we must set a close flag
3522 * on it now, and then when the server acks the channel
3523 * open, we can close it then.
3525 if (((int)c->remoteid) != -1) {
3526 if (ssh->version == 1) {
3527 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3530 struct Packet *pktout;
3531 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3532 ssh2_pkt_adduint32(pktout, c->remoteid);
3533 ssh2_pkt_send(ssh, pktout);
3536 c->closes = 1; /* sent MSG_CLOSE */
3537 if (c->type == CHAN_X11) {
3539 logevent("Forwarded X11 connection terminated");
3540 } else if (c->type == CHAN_SOCKDATA ||
3541 c->type == CHAN_SOCKDATA_DORMANT) {
3543 logevent("Forwarded port closed");
3548 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3552 if (ssh->state != SSH_STATE_SESSION) {
3553 assert(ssh->state == SSH_STATE_CLOSED);
3557 if (ssh->version == 1) {
3558 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3559 PKT_INT, c->remoteid,
3561 PKT_INT, len, PKT_DATA, buf, len,
3562 PKTT_OTHER, PKT_END);
3564 * In SSH1 we can return 0 here - implying that forwarded
3565 * connections are never individually throttled - because
3566 * the only circumstance that can cause throttling will be
3567 * the whole SSH connection backing up, in which case
3568 * _everything_ will be throttled as a whole.
3572 ssh2_add_channel_data(c, buf, len);
3573 return ssh2_try_send(c);
3577 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3581 if (ssh->state != SSH_STATE_SESSION) {
3582 assert(ssh->state == SSH_STATE_CLOSED);
3586 if (ssh->version == 1) {
3587 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3588 c->v.v1.throttling = 0;
3589 ssh1_throttle(ssh, -1);
3592 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3596 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
3598 struct queued_handler *qh = ssh->qhead;
3602 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
3605 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
3606 ssh->packet_dispatch[qh->msg1] = NULL;
3609 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
3610 ssh->packet_dispatch[qh->msg2] = NULL;
3614 ssh->qhead = qh->next;
3616 if (ssh->qhead->msg1 > 0) {
3617 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
3618 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
3620 if (ssh->qhead->msg2 > 0) {
3621 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
3622 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
3625 ssh->qhead = ssh->qtail = NULL;
3626 ssh->packet_dispatch[pktin->type] = NULL;
3629 qh->handler(ssh, pktin, qh->ctx);
3634 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
3635 chandler_fn_t handler, void *ctx)
3637 struct queued_handler *qh;
3639 qh = snew(struct queued_handler);
3642 qh->handler = handler;
3646 if (ssh->qtail == NULL) {
3650 assert(ssh->packet_dispatch[qh->msg1] == NULL);
3651 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
3654 assert(ssh->packet_dispatch[qh->msg2] == NULL);
3655 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
3658 ssh->qtail->next = qh;
3663 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
3665 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
3667 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
3668 SSH2_MSG_REQUEST_SUCCESS)) {
3669 logeventf(ssh, "Remote port forwarding from %s enabled",
3672 logeventf(ssh, "Remote port forwarding from %s refused",
3675 rpf = del234(ssh->rportfwds, pf);
3681 static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
3683 const char *portfwd_strptr = cfg->portfwd;
3684 struct ssh_portfwd *epf;
3687 if (!ssh->portfwds) {
3688 ssh->portfwds = newtree234(ssh_portcmp);
3691 * Go through the existing port forwardings and tag them
3692 * with status==DESTROY. Any that we want to keep will be
3693 * re-enabled (status==KEEP) as we go through the
3694 * configuration and find out which bits are the same as
3697 struct ssh_portfwd *epf;
3699 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3700 epf->status = DESTROY;
3703 while (*portfwd_strptr) {
3704 char address_family, type;
3705 int sport,dport,sserv,dserv;
3706 char sports[256], dports[256], saddr[256], host[256];
3709 address_family = 'A';
3711 if (*portfwd_strptr == 'A' ||
3712 *portfwd_strptr == '4' ||
3713 *portfwd_strptr == '6')
3714 address_family = *portfwd_strptr++;
3715 if (*portfwd_strptr == 'L' ||
3716 *portfwd_strptr == 'R' ||
3717 *portfwd_strptr == 'D')
3718 type = *portfwd_strptr++;
3723 while (*portfwd_strptr && *portfwd_strptr != '\t') {
3724 if (*portfwd_strptr == ':') {
3726 * We've seen a colon in the middle of the
3727 * source port number. This means that
3728 * everything we've seen until now is the
3729 * source _address_, so we'll move it into
3730 * saddr and start sports from the beginning
3735 if (ssh->version == 1 && type == 'R') {
3736 logeventf(ssh, "SSH1 cannot handle remote source address "
3737 "spec \"%s\"; ignoring", sports);
3739 strcpy(saddr, sports);
3742 if (n < 255) sports[n++] = *portfwd_strptr++;
3746 if (*portfwd_strptr == '\t')
3749 while (*portfwd_strptr && *portfwd_strptr != ':') {
3750 if (n < 255) host[n++] = *portfwd_strptr++;
3753 if (*portfwd_strptr == ':')
3756 while (*portfwd_strptr) {
3757 if (n < 255) dports[n++] = *portfwd_strptr++;
3761 dport = atoi(dports);
3765 dport = net_service_lookup(dports);
3767 logeventf(ssh, "Service lookup failed for destination"
3768 " port \"%s\"", dports);
3772 while (*portfwd_strptr) portfwd_strptr++;
3774 portfwd_strptr++; /* eat the NUL and move to next one */
3776 sport = atoi(sports);
3780 sport = net_service_lookup(sports);
3782 logeventf(ssh, "Service lookup failed for source"
3783 " port \"%s\"", sports);
3786 if (sport && dport) {
3787 /* Set up a description of the source port. */
3788 struct ssh_portfwd *pfrec, *epfrec;
3790 pfrec = snew(struct ssh_portfwd);
3792 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
3793 pfrec->sserv = sserv ? dupstr(sports) : NULL;
3794 pfrec->sport = sport;
3795 pfrec->daddr = *host ? dupstr(host) : NULL;
3796 pfrec->dserv = dserv ? dupstr(dports) : NULL;
3797 pfrec->dport = dport;
3798 pfrec->local = NULL;
3799 pfrec->remote = NULL;
3800 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
3801 address_family == '6' ? ADDRTYPE_IPV6 :
3804 epfrec = add234(ssh->portfwds, pfrec);
3805 if (epfrec != pfrec) {
3807 * We already have a port forwarding with precisely
3808 * these parameters. Hence, no need to do anything;
3809 * simply tag the existing one as KEEP.
3811 epfrec->status = KEEP;
3812 free_portfwd(pfrec);
3814 pfrec->status = CREATE;
3820 * Now go through and destroy any port forwardings which were
3823 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3824 if (epf->status == DESTROY) {
3827 message = dupprintf("%s port forwarding from %s%s%d",
3828 epf->type == 'L' ? "local" :
3829 epf->type == 'R' ? "remote" : "dynamic",
3830 epf->saddr ? epf->saddr : "",
3831 epf->saddr ? ":" : "",
3834 if (epf->type != 'D') {
3835 char *msg2 = dupprintf("%s to %s:%d", message,
3836 epf->daddr, epf->dport);
3841 logeventf(ssh, "Cancelling %s", message);
3845 struct ssh_rportfwd *rpf = epf->remote;
3846 struct Packet *pktout;
3849 * Cancel the port forwarding at the server
3852 if (ssh->version == 1) {
3854 * We cannot cancel listening ports on the
3855 * server side in SSH1! There's no message
3856 * to support it. Instead, we simply remove
3857 * the rportfwd record from the local end
3858 * so that any connections the server tries
3859 * to make on it are rejected.
3862 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
3863 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
3864 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
3866 ssh2_pkt_addstring(pktout, epf->saddr);
3867 } else if (ssh->cfg.rport_acceptall) {
3868 ssh2_pkt_addstring(pktout, "0.0.0.0");
3870 ssh2_pkt_addstring(pktout, "127.0.0.1");
3872 ssh2_pkt_adduint32(pktout, epf->sport);
3873 ssh2_pkt_send(ssh, pktout);
3876 del234(ssh->rportfwds, rpf);
3878 } else if (epf->local) {
3879 pfd_terminate(epf->local);
3882 delpos234(ssh->portfwds, i);
3884 i--; /* so we don't skip one in the list */
3888 * And finally, set up any new port forwardings (status==CREATE).
3890 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3891 if (epf->status == CREATE) {
3892 char *sportdesc, *dportdesc;
3893 sportdesc = dupprintf("%s%s%s%s%d%s",
3894 epf->saddr ? epf->saddr : "",
3895 epf->saddr ? ":" : "",
3896 epf->sserv ? epf->sserv : "",
3897 epf->sserv ? "(" : "",
3899 epf->sserv ? ")" : "");
3900 if (epf->type == 'D') {
3903 dportdesc = dupprintf("%s:%s%s%d%s",
3905 epf->dserv ? epf->dserv : "",
3906 epf->dserv ? "(" : "",
3908 epf->dserv ? ")" : "");
3911 if (epf->type == 'L') {
3912 const char *err = pfd_addforward(epf->daddr, epf->dport,
3913 epf->saddr, epf->sport,
3916 epf->addressfamily);
3918 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
3919 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
3920 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
3921 sportdesc, dportdesc,
3922 err ? " failed: " : "", err ? err : "");
3923 } else if (epf->type == 'D') {
3924 const char *err = pfd_addforward(NULL, -1,
3925 epf->saddr, epf->sport,
3928 epf->addressfamily);
3930 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
3931 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
3932 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
3934 err ? " failed: " : "", err ? err : "");
3936 struct ssh_rportfwd *pf;
3939 * Ensure the remote port forwardings tree exists.
3941 if (!ssh->rportfwds) {
3942 if (ssh->version == 1)
3943 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3945 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
3948 pf = snew(struct ssh_rportfwd);
3949 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
3950 pf->dhost[lenof(pf->dhost)-1] = '\0';
3951 pf->dport = epf->dport;
3952 pf->sport = epf->sport;
3953 if (add234(ssh->rportfwds, pf) != pf) {
3954 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
3955 epf->daddr, epf->dport);
3958 logeventf(ssh, "Requesting remote port %s"
3959 " forward to %s", sportdesc, dportdesc);
3961 pf->sportdesc = sportdesc;
3966 if (ssh->version == 1) {
3967 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
3968 PKT_INT, epf->sport,
3969 PKT_STR, epf->daddr,
3970 PKT_INT, epf->dport,
3972 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
3974 ssh_rportfwd_succfail, pf);
3976 struct Packet *pktout;
3977 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
3978 ssh2_pkt_addstring(pktout, "tcpip-forward");
3979 ssh2_pkt_addbool(pktout, 1);/* want reply */
3981 ssh2_pkt_addstring(pktout, epf->saddr);
3982 } else if (ssh->cfg.rport_acceptall) {
3983 ssh2_pkt_addstring(pktout, "0.0.0.0");
3985 ssh2_pkt_addstring(pktout, "127.0.0.1");
3987 ssh2_pkt_adduint32(pktout, epf->sport);
3988 ssh2_pkt_send(ssh, pktout);
3990 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
3991 SSH2_MSG_REQUEST_FAILURE,
3992 ssh_rportfwd_succfail, pf);
4001 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4004 int stringlen, bufsize;
4006 ssh_pkt_getstring(pktin, &string, &stringlen);
4007 if (string == NULL) {
4008 bombout(("Incoming terminal data packet was badly formed"));
4012 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4014 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4015 ssh->v1_stdout_throttling = 1;
4016 ssh1_throttle(ssh, +1);
4020 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4022 /* Remote side is trying to open a channel to talk to our
4023 * X-Server. Give them back a local channel number. */
4024 struct ssh_channel *c;
4025 int remoteid = ssh_pkt_getuint32(pktin);
4027 logevent("Received X11 connect request");
4028 /* Refuse if X11 forwarding is disabled. */
4029 if (!ssh->X11_fwd_enabled) {
4030 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4031 PKT_INT, remoteid, PKT_END);
4032 logevent("Rejected X11 connect request");
4034 c = snew(struct ssh_channel);
4037 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
4038 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
4039 logevent("Opening X11 forward connection failed");
4041 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4042 PKT_INT, remoteid, PKT_END);
4045 ("Opening X11 forward connection succeeded");
4046 c->remoteid = remoteid;
4047 c->localid = alloc_channel_id(ssh);
4049 c->v.v1.throttling = 0;
4050 c->type = CHAN_X11; /* identify channel type */
4051 add234(ssh->channels, c);
4052 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4053 PKT_INT, c->remoteid, PKT_INT,
4054 c->localid, PKT_END);
4055 logevent("Opened X11 forward channel");
4060 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4062 /* Remote side is trying to open a channel to talk to our
4063 * agent. Give them back a local channel number. */
4064 struct ssh_channel *c;
4065 int remoteid = ssh_pkt_getuint32(pktin);
4067 /* Refuse if agent forwarding is disabled. */
4068 if (!ssh->agentfwd_enabled) {
4069 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4070 PKT_INT, remoteid, PKT_END);
4072 c = snew(struct ssh_channel);
4074 c->remoteid = remoteid;
4075 c->localid = alloc_channel_id(ssh);
4077 c->v.v1.throttling = 0;
4078 c->type = CHAN_AGENT; /* identify channel type */
4079 c->u.a.lensofar = 0;
4080 add234(ssh->channels, c);
4081 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4082 PKT_INT, c->remoteid, PKT_INT, c->localid,
4087 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4089 /* Remote side is trying to open a channel to talk to a
4090 * forwarded port. Give them back a local channel number. */
4091 struct ssh_channel *c;
4092 struct ssh_rportfwd pf, *pfp;
4095 char *host, buf[1024];
4097 c = snew(struct ssh_channel);
4100 remoteid = ssh_pkt_getuint32(pktin);
4101 ssh_pkt_getstring(pktin, &host, &hostsize);
4102 port = ssh_pkt_getuint32(pktin);
4104 if (hostsize >= lenof(pf.dhost))
4105 hostsize = lenof(pf.dhost)-1;
4106 memcpy(pf.dhost, host, hostsize);
4107 pf.dhost[hostsize] = '\0';
4109 pfp = find234(ssh->rportfwds, &pf, NULL);
4112 sprintf(buf, "Rejected remote port open request for %s:%d",
4115 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4116 PKT_INT, remoteid, PKT_END);
4118 sprintf(buf, "Received remote port open request for %s:%d",
4121 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
4122 c, &ssh->cfg, pfp->pfrec->addressfamily);
4125 sprintf(buf, "Port open failed: %s", e);
4128 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4129 PKT_INT, remoteid, PKT_END);
4131 c->remoteid = remoteid;
4132 c->localid = alloc_channel_id(ssh);
4134 c->v.v1.throttling = 0;
4135 c->type = CHAN_SOCKDATA; /* identify channel type */
4136 add234(ssh->channels, c);
4137 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4138 PKT_INT, c->remoteid, PKT_INT,
4139 c->localid, PKT_END);
4140 logevent("Forwarded port opened successfully");
4145 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4147 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4148 unsigned int localid = ssh_pkt_getuint32(pktin);
4149 struct ssh_channel *c;
4151 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4152 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4153 c->remoteid = localid;
4154 c->type = CHAN_SOCKDATA;
4155 c->v.v1.throttling = 0;
4156 pfd_confirm(c->u.pfd.s);
4159 if (c && c->closes) {
4161 * We have a pending close on this channel,
4162 * which we decided on before the server acked
4163 * the channel open. So now we know the
4164 * remoteid, we can close it again.
4166 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4167 PKT_INT, c->remoteid, PKT_END);
4171 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4173 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4174 struct ssh_channel *c;
4176 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4177 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4178 logevent("Forwarded connection refused by server");
4179 pfd_close(c->u.pfd.s);
4180 del234(ssh->channels, c);
4185 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4187 /* Remote side closes a channel. */
4188 unsigned i = ssh_pkt_getuint32(pktin);
4189 struct ssh_channel *c;
4190 c = find234(ssh->channels, &i, ssh_channelfind);
4191 if (c && ((int)c->remoteid) != -1) {
4194 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4196 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4197 logevent("Forwarded X11 connection terminated");
4198 assert(c->u.x11.s != NULL);
4199 x11_close(c->u.x11.s);
4202 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4203 logevent("Forwarded port closed");
4204 assert(c->u.pfd.s != NULL);
4205 pfd_close(c->u.pfd.s);
4209 c->closes |= (closetype << 2); /* seen this message */
4210 if (!(c->closes & closetype)) {
4211 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4213 c->closes |= closetype; /* sent it too */
4216 if (c->closes == 15) {
4217 del234(ssh->channels, c);
4221 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4222 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4223 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4228 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4230 /* Data sent down one of our channels. */
4231 int i = ssh_pkt_getuint32(pktin);
4234 struct ssh_channel *c;
4236 ssh_pkt_getstring(pktin, &p, &len);
4238 c = find234(ssh->channels, &i, ssh_channelfind);
4243 bufsize = x11_send(c->u.x11.s, p, len);
4246 bufsize = pfd_send(c->u.pfd.s, p, len);
4249 /* Data for an agent message. Buffer it. */
4251 if (c->u.a.lensofar < 4) {
4252 unsigned int l = min(4 - c->u.a.lensofar, len);
4253 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4257 c->u.a.lensofar += l;
4259 if (c->u.a.lensofar == 4) {
4261 4 + GET_32BIT(c->u.a.msglen);
4262 c->u.a.message = snewn(c->u.a.totallen,
4264 memcpy(c->u.a.message, c->u.a.msglen, 4);
4266 if (c->u.a.lensofar >= 4 && len > 0) {
4268 min(c->u.a.totallen - c->u.a.lensofar,
4270 memcpy(c->u.a.message + c->u.a.lensofar, p,
4274 c->u.a.lensofar += l;
4276 if (c->u.a.lensofar == c->u.a.totallen) {
4279 if (agent_query(c->u.a.message,
4282 ssh_agentf_callback, c))
4283 ssh_agentf_callback(c, reply, replylen);
4284 sfree(c->u.a.message);
4285 c->u.a.lensofar = 0;
4288 bufsize = 0; /* agent channels never back up */
4291 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4292 c->v.v1.throttling = 1;
4293 ssh1_throttle(ssh, +1);
4298 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
4301 ssh->exitcode = ssh_pkt_getuint32(pktin);
4302 sprintf(buf, "Server sent command exit status %d",
4305 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4307 * In case `helpful' firewalls or proxies tack
4308 * extra human-readable text on the end of the
4309 * session which we might mistake for another
4310 * encrypted packet, we close the session once
4311 * we've sent EXIT_CONFIRMATION.
4313 ssh_closing((Plug)ssh, NULL, 0, 0);
4316 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
4317 struct Packet *pktin)
4319 crBegin(ssh->do_ssh1_connection_crstate);
4321 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
4322 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
4323 ssh1_smsg_stdout_stderr_data;
4325 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
4326 ssh1_msg_channel_open_confirmation;
4327 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
4328 ssh1_msg_channel_open_failure;
4329 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
4330 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
4331 ssh1_msg_channel_close;
4332 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
4333 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
4335 if (ssh->cfg.agentfwd && agent_exists()) {
4336 logevent("Requesting agent forwarding");
4337 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
4341 if (pktin->type != SSH1_SMSG_SUCCESS
4342 && pktin->type != SSH1_SMSG_FAILURE) {
4343 bombout(("Protocol confusion"));
4345 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4346 logevent("Agent forwarding refused");
4348 logevent("Agent forwarding enabled");
4349 ssh->agentfwd_enabled = TRUE;
4350 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
4354 if (ssh->cfg.x11_forward) {
4355 char proto[20], data[64];
4356 logevent("Requesting X11 forwarding");
4357 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
4358 data, sizeof(data), ssh->cfg.x11_auth);
4359 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
4360 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
4361 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4362 PKT_STR, proto, PKT_STR, data,
4363 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
4366 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4367 PKT_STR, proto, PKT_STR, data, PKT_END);
4372 if (pktin->type != SSH1_SMSG_SUCCESS
4373 && pktin->type != SSH1_SMSG_FAILURE) {
4374 bombout(("Protocol confusion"));
4376 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4377 logevent("X11 forwarding refused");
4379 logevent("X11 forwarding enabled");
4380 ssh->X11_fwd_enabled = TRUE;
4381 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
4385 ssh_setup_portfwd(ssh, &ssh->cfg);
4386 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
4388 if (!ssh->cfg.nopty) {
4389 /* Unpick the terminal-speed string. */
4390 /* XXX perhaps we should allow no speeds to be sent. */
4391 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4392 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
4393 /* Send the pty request. */
4394 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
4395 PKT_STR, ssh->cfg.termtype,
4396 PKT_INT, ssh->term_height,
4397 PKT_INT, ssh->term_width,
4398 PKT_INT, 0, PKT_INT, 0, /* width,height in pixels */
4399 PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */
4400 PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */
4401 PKT_CHAR, 0, PKT_END);
4402 ssh->state = SSH_STATE_INTERMED;
4406 if (pktin->type != SSH1_SMSG_SUCCESS
4407 && pktin->type != SSH1_SMSG_FAILURE) {
4408 bombout(("Protocol confusion"));
4410 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4411 c_write_str(ssh, "Server refused to allocate pty\r\n");
4412 ssh->editing = ssh->echoing = 1;
4414 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
4415 ssh->ospeed, ssh->ispeed);
4417 ssh->editing = ssh->echoing = 1;
4420 if (ssh->cfg.compression) {
4421 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
4425 if (pktin->type != SSH1_SMSG_SUCCESS
4426 && pktin->type != SSH1_SMSG_FAILURE) {
4427 bombout(("Protocol confusion"));
4429 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4430 c_write_str(ssh, "Server refused to compress\r\n");
4432 logevent("Started compression");
4433 ssh->v1_compressing = TRUE;
4434 ssh->cs_comp_ctx = zlib_compress_init();
4435 logevent("Initialised zlib (RFC1950) compression");
4436 ssh->sc_comp_ctx = zlib_decompress_init();
4437 logevent("Initialised zlib (RFC1950) decompression");
4441 * Start the shell or command.
4443 * Special case: if the first-choice command is an SSH2
4444 * subsystem (hence not usable here) and the second choice
4445 * exists, we fall straight back to that.
4448 char *cmd = ssh->cfg.remote_cmd_ptr;
4450 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4451 cmd = ssh->cfg.remote_cmd_ptr2;
4452 ssh->fallback_cmd = TRUE;
4455 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
4457 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
4458 logevent("Started session");
4461 ssh->state = SSH_STATE_SESSION;
4462 if (ssh->size_needed)
4463 ssh_size(ssh, ssh->term_width, ssh->term_height);
4464 if (ssh->eof_needed)
4465 ssh_special(ssh, TS_EOF);
4468 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
4470 ssh->channels = newtree234(ssh_channelcmp);
4474 * By this point, most incoming packets are already being
4475 * handled by the dispatch table, and we need only pay
4476 * attention to the unusual ones.
4481 if (pktin->type == SSH1_SMSG_SUCCESS) {
4482 /* may be from EXEC_SHELL on some servers */
4483 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4484 /* may be from EXEC_SHELL on some servers
4485 * if no pty is available or in other odd cases. Ignore */
4487 bombout(("Strange packet received: type %d", pktin->type));
4492 int len = min(inlen, 512);
4493 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4494 PKT_INT, len, PKT_DATA, in, len,
4495 PKTT_OTHER, PKT_END);
4506 * Handle the top-level SSH2 protocol.
4508 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4513 ssh_pkt_getstring(pktin, &msg, &msglen);
4514 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
4519 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4521 /* log reason code in disconnect message */
4525 ssh_pkt_getstring(pktin, &msg, &msglen);
4526 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4529 void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
4531 /* Do nothing, because we're ignoring it! Duhh. */
4534 static void ssh1_protocol_setup(Ssh ssh)
4539 * Most messages are handled by the coroutines.
4541 for (i = 0; i < 256; i++)
4542 ssh->packet_dispatch[i] = NULL;
4545 * These special message types we install handlers for.
4547 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4548 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4549 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4552 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
4553 struct Packet *pktin)
4555 if (ssh->state == SSH_STATE_CLOSED)
4558 if (pktin && ssh->packet_dispatch[pktin->type]) {
4559 ssh->packet_dispatch[pktin->type](ssh, pktin);
4563 if (!ssh->protocol_initial_phase_done) {
4564 if (do_ssh1_login(ssh, in, inlen, pktin))
4565 ssh->protocol_initial_phase_done = TRUE;
4570 do_ssh1_connection(ssh, in, inlen, pktin);
4574 * Utility routine for decoding comma-separated strings in KEXINIT.
4576 static int in_commasep_string(char *needle, char *haystack, int haylen)
4579 if (!needle || !haystack) /* protect against null pointers */
4581 needlen = strlen(needle);
4584 * Is it at the start of the string?
4586 if (haylen >= needlen && /* haystack is long enough */
4587 !memcmp(needle, haystack, needlen) && /* initial match */
4588 (haylen == needlen || haystack[needlen] == ',')
4589 /* either , or EOS follows */
4593 * If not, search for the next comma and resume after that.
4594 * If no comma found, terminate.
4596 while (haylen > 0 && *haystack != ',')
4597 haylen--, haystack++;
4600 haylen--, haystack++; /* skip over comma itself */
4605 * SSH2 key creation method.
4607 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4608 unsigned char *sessid, char chr,
4609 unsigned char *keyspace)
4612 /* First 20 bytes. */
4614 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4616 SHA_Bytes(&s, H, 20);
4617 SHA_Bytes(&s, &chr, 1);
4618 SHA_Bytes(&s, sessid, 20);
4619 SHA_Final(&s, keyspace);
4620 /* Next 20 bytes. */
4622 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4624 SHA_Bytes(&s, H, 20);
4625 SHA_Bytes(&s, keyspace, 20);
4626 SHA_Final(&s, keyspace + 20);
4630 * Handle the SSH2 transport layer.
4632 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
4633 struct Packet *pktin)
4635 struct do_ssh2_transport_state {
4636 int nbits, pbits, warn;
4637 Bignum p, g, e, f, K;
4638 int kex_init_value, kex_reply_value;
4639 const struct ssh_mac **maclist;
4641 const struct ssh2_cipher *cscipher_tobe;
4642 const struct ssh2_cipher *sccipher_tobe;
4643 const struct ssh_mac *csmac_tobe;
4644 const struct ssh_mac *scmac_tobe;
4645 const struct ssh_compress *cscomp_tobe;
4646 const struct ssh_compress *sccomp_tobe;
4647 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4648 int hostkeylen, siglen;
4649 void *hkey; /* actual host key */
4650 unsigned char exchange_hash[20];
4651 int n_preferred_kex;
4652 const struct ssh_kex *preferred_kex[KEX_MAX];
4653 int n_preferred_ciphers;
4654 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4655 const struct ssh_compress *preferred_comp;
4656 int got_session_id, activated_authconn;
4657 struct Packet *pktout;
4659 crState(do_ssh2_transport_state);
4661 crBegin(ssh->do_ssh2_transport_crstate);
4663 s->cscipher_tobe = s->sccipher_tobe = NULL;
4664 s->csmac_tobe = s->scmac_tobe = NULL;
4665 s->cscomp_tobe = s->sccomp_tobe = NULL;
4667 s->got_session_id = s->activated_authconn = FALSE;
4670 * Be prepared to work around the buggy MAC problem.
4672 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4673 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
4675 s->maclist = macs, s->nmacs = lenof(macs);
4679 int i, j, commalist_started;
4682 * Set up the preferred key exchange. (NULL => warn below here)
4684 s->n_preferred_kex = 0;
4685 for (i = 0; i < KEX_MAX; i++) {
4686 switch (ssh->cfg.ssh_kexlist[i]) {
4688 s->preferred_kex[s->n_preferred_kex++] =
4689 &ssh_diffiehellman_gex;
4692 s->preferred_kex[s->n_preferred_kex++] =
4693 &ssh_diffiehellman_group14;
4696 s->preferred_kex[s->n_preferred_kex++] =
4697 &ssh_diffiehellman_group1;
4700 /* Flag for later. Don't bother if it's the last in
4702 if (i < KEX_MAX - 1) {
4703 s->preferred_kex[s->n_preferred_kex++] = NULL;
4710 * Set up the preferred ciphers. (NULL => warn below here)
4712 s->n_preferred_ciphers = 0;
4713 for (i = 0; i < CIPHER_MAX; i++) {
4714 switch (ssh->cfg.ssh_cipherlist[i]) {
4715 case CIPHER_BLOWFISH:
4716 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
4719 if (ssh->cfg.ssh2_des_cbc) {
4720 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
4724 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
4727 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
4730 /* Flag for later. Don't bother if it's the last in
4732 if (i < CIPHER_MAX - 1) {
4733 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
4740 * Set up preferred compression.
4742 if (ssh->cfg.compression)
4743 s->preferred_comp = &ssh_zlib;
4745 s->preferred_comp = &ssh_comp_none;
4748 * Enable queueing of outgoing auth- or connection-layer
4749 * packets while we are in the middle of a key exchange.
4751 ssh->queueing = TRUE;
4754 * Flag that KEX is in progress.
4756 ssh->kex_in_progress = TRUE;
4759 * Construct and send our key exchange packet.
4761 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
4762 for (i = 0; i < 16; i++)
4763 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
4764 /* List key exchange algorithms. */
4765 ssh2_pkt_addstring_start(s->pktout);
4766 commalist_started = 0;
4767 for (i = 0; i < s->n_preferred_kex; i++) {
4768 const struct ssh_kex *k = s->preferred_kex[i];
4769 if (!k) continue; /* warning flag */
4770 if (commalist_started)
4771 ssh2_pkt_addstring_str(s->pktout, ",");
4772 ssh2_pkt_addstring_str(s->pktout, s->preferred_kex[i]->name);
4773 commalist_started = 1;
4775 /* List server host key algorithms. */
4776 ssh2_pkt_addstring_start(s->pktout);
4777 for (i = 0; i < lenof(hostkey_algs); i++) {
4778 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
4779 if (i < lenof(hostkey_algs) - 1)
4780 ssh2_pkt_addstring_str(s->pktout, ",");
4782 /* List client->server encryption algorithms. */
4783 ssh2_pkt_addstring_start(s->pktout);
4784 commalist_started = 0;
4785 for (i = 0; i < s->n_preferred_ciphers; i++) {
4786 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4787 if (!c) continue; /* warning flag */
4788 for (j = 0; j < c->nciphers; j++) {
4789 if (commalist_started)
4790 ssh2_pkt_addstring_str(s->pktout, ",");
4791 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
4792 commalist_started = 1;
4795 /* List server->client encryption algorithms. */
4796 ssh2_pkt_addstring_start(s->pktout);
4797 commalist_started = 0;
4798 for (i = 0; i < s->n_preferred_ciphers; i++) {
4799 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4800 if (!c) continue; /* warning flag */
4801 for (j = 0; j < c->nciphers; j++) {
4802 if (commalist_started)
4803 ssh2_pkt_addstring_str(s->pktout, ",");
4804 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
4805 commalist_started = 1;
4808 /* List client->server MAC algorithms. */
4809 ssh2_pkt_addstring_start(s->pktout);
4810 for (i = 0; i < s->nmacs; i++) {
4811 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
4812 if (i < s->nmacs - 1)
4813 ssh2_pkt_addstring_str(s->pktout, ",");
4815 /* List server->client MAC algorithms. */
4816 ssh2_pkt_addstring_start(s->pktout);
4817 for (i = 0; i < s->nmacs; i++) {
4818 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
4819 if (i < s->nmacs - 1)
4820 ssh2_pkt_addstring_str(s->pktout, ",");
4822 /* List client->server compression algorithms. */
4823 ssh2_pkt_addstring_start(s->pktout);
4824 assert(lenof(compressions) > 1);
4825 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
4826 for (i = 0; i < lenof(compressions); i++) {
4827 const struct ssh_compress *c = compressions[i];
4828 if (c != s->preferred_comp) {
4829 ssh2_pkt_addstring_str(s->pktout, ",");
4830 ssh2_pkt_addstring_str(s->pktout, c->name);
4833 /* List server->client compression algorithms. */
4834 ssh2_pkt_addstring_start(s->pktout);
4835 assert(lenof(compressions) > 1);
4836 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
4837 for (i = 0; i < lenof(compressions); i++) {
4838 const struct ssh_compress *c = compressions[i];
4839 if (c != s->preferred_comp) {
4840 ssh2_pkt_addstring_str(s->pktout, ",");
4841 ssh2_pkt_addstring_str(s->pktout, c->name);
4844 /* List client->server languages. Empty list. */
4845 ssh2_pkt_addstring_start(s->pktout);
4846 /* List server->client languages. Empty list. */
4847 ssh2_pkt_addstring_start(s->pktout);
4848 /* First KEX packet does _not_ follow, because we're not that brave. */
4849 ssh2_pkt_addbool(s->pktout, FALSE);
4851 ssh2_pkt_adduint32(s->pktout, 0);
4854 ssh->exhash = ssh->exhashbase;
4855 sha_string(&ssh->exhash, s->pktout->data + 5, s->pktout->length - 5);
4857 ssh2_pkt_send_noqueue(ssh, s->pktout);
4861 if (pktin->length > 5)
4862 sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5);
4865 * Now examine the other side's KEXINIT to see what we're up
4872 if (pktin->type != SSH2_MSG_KEXINIT) {
4873 bombout(("expected key exchange packet from server"));
4877 ssh->hostkey = NULL;
4878 s->cscipher_tobe = NULL;
4879 s->sccipher_tobe = NULL;
4880 s->csmac_tobe = NULL;
4881 s->scmac_tobe = NULL;
4882 s->cscomp_tobe = NULL;
4883 s->sccomp_tobe = NULL;
4884 pktin->savedpos += 16; /* skip garbage cookie */
4885 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
4887 for (i = 0; i < s->n_preferred_kex; i++) {
4888 const struct ssh_kex *k = s->preferred_kex[i];
4891 } else if (in_commasep_string(k->name, str, len)) {
4896 sk_set_frozen(ssh->s, 1);
4897 askalg(ssh->frontend, "key-exchange algorithm",
4899 sk_set_frozen(ssh->s, 0);
4905 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
4906 str ? str : "(null)"));
4909 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
4910 for (i = 0; i < lenof(hostkey_algs); i++) {
4911 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
4912 ssh->hostkey = hostkey_algs[i];
4916 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
4918 for (i = 0; i < s->n_preferred_ciphers; i++) {
4919 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4923 for (j = 0; j < c->nciphers; j++) {
4924 if (in_commasep_string(c->list[j]->name, str, len)) {
4925 s->cscipher_tobe = c->list[j];
4930 if (s->cscipher_tobe) {
4932 sk_set_frozen(ssh->s, 1);
4933 askalg(ssh->frontend, "client-to-server cipher",
4934 s->cscipher_tobe->name);
4935 sk_set_frozen(ssh->s, 0);
4940 if (!s->cscipher_tobe) {
4941 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
4942 str ? str : "(null)"));
4946 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
4948 for (i = 0; i < s->n_preferred_ciphers; i++) {
4949 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4953 for (j = 0; j < c->nciphers; j++) {
4954 if (in_commasep_string(c->list[j]->name, str, len)) {
4955 s->sccipher_tobe = c->list[j];
4960 if (s->sccipher_tobe) {
4962 sk_set_frozen(ssh->s, 1);
4963 askalg(ssh->frontend, "server-to-client cipher",
4964 s->sccipher_tobe->name);
4965 sk_set_frozen(ssh->s, 0);
4970 if (!s->sccipher_tobe) {
4971 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
4972 str ? str : "(null)"));
4976 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
4977 for (i = 0; i < s->nmacs; i++) {
4978 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4979 s->csmac_tobe = s->maclist[i];
4983 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
4984 for (i = 0; i < s->nmacs; i++) {
4985 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4986 s->scmac_tobe = s->maclist[i];
4990 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
4991 for (i = 0; i < lenof(compressions) + 1; i++) {
4992 const struct ssh_compress *c =
4993 i == 0 ? s->preferred_comp : compressions[i - 1];
4994 if (in_commasep_string(c->name, str, len)) {
4999 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
5000 for (i = 0; i < lenof(compressions) + 1; i++) {
5001 const struct ssh_compress *c =
5002 i == 0 ? s->preferred_comp : compressions[i - 1];
5003 if (in_commasep_string(c->name, str, len)) {
5011 * Work out the number of bits of key we will need from the key
5012 * exchange. We start with the maximum key length of either
5018 csbits = s->cscipher_tobe->keylen;
5019 scbits = s->sccipher_tobe->keylen;
5020 s->nbits = (csbits > scbits ? csbits : scbits);
5022 /* The keys only have 160-bit entropy, since they're based on
5023 * a SHA-1 hash. So cap the key size at 160 bits. */
5028 * If we're doing Diffie-Hellman group exchange, start by
5029 * requesting a group.
5031 if (!ssh->kex->pdata) {
5032 logevent("Doing Diffie-Hellman group exchange");
5033 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
5035 * Work out how big a DH group we will need to allow that
5038 s->pbits = 512 << ((s->nbits - 1) / 64);
5039 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5040 ssh2_pkt_adduint32(s->pktout, s->pbits);
5041 ssh2_pkt_send_noqueue(ssh, s->pktout);
5044 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
5045 bombout(("expected key exchange group packet from server"));
5048 s->p = ssh2_pkt_getmp(pktin);
5049 s->g = ssh2_pkt_getmp(pktin);
5050 if (!s->p || !s->g) {
5051 bombout(("unable to read mp-ints from incoming group packet"));
5054 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
5055 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5056 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
5058 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP;
5059 ssh->kex_ctx = dh_setup_group(ssh->kex);
5060 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5061 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
5062 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5063 ssh->kex->groupname);
5066 logevent("Doing Diffie-Hellman key exchange");
5068 * Now generate and send e for Diffie-Hellman.
5070 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
5071 s->pktout = ssh2_pkt_init(s->kex_init_value);
5072 ssh2_pkt_addmp(s->pktout, s->e);
5073 ssh2_pkt_send_noqueue(ssh, s->pktout);
5076 if (pktin->type != s->kex_reply_value) {
5077 bombout(("expected key exchange reply packet from server"));
5080 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5081 s->f = ssh2_pkt_getmp(pktin);
5083 bombout(("unable to parse key exchange reply packet"));
5086 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
5088 s->K = dh_find_K(ssh->kex_ctx, s->f);
5090 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
5091 if (ssh->kex == &ssh_diffiehellman_gex) {
5092 sha_uint32(&ssh->exhash, s->pbits);
5093 sha_mpint(&ssh->exhash, s->p);
5094 sha_mpint(&ssh->exhash, s->g);
5096 sha_mpint(&ssh->exhash, s->e);
5097 sha_mpint(&ssh->exhash, s->f);
5098 sha_mpint(&ssh->exhash, s->K);
5099 SHA_Final(&ssh->exhash, s->exchange_hash);
5101 dh_cleanup(ssh->kex_ctx);
5102 ssh->kex_ctx = NULL;
5105 debug(("Exchange hash is:\n"));
5106 dmemdump(s->exchange_hash, 20);
5109 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5111 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
5112 (char *)s->exchange_hash, 20)) {
5113 bombout(("Server's host key did not match the signature supplied"));
5118 * Authenticate remote host: verify host key. (We've already
5119 * checked the signature of the exchange hash.)
5121 s->keystr = ssh->hostkey->fmtkey(s->hkey);
5122 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
5123 sk_set_frozen(ssh->s, 1);
5124 verify_ssh_host_key(ssh->frontend,
5125 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
5126 s->keystr, s->fingerprint);
5127 sk_set_frozen(ssh->s, 0);
5128 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5129 logevent("Host key fingerprint is:");
5130 logevent(s->fingerprint);
5132 sfree(s->fingerprint);
5134 ssh->hostkey->freekey(s->hkey);
5137 * The exchange hash from the very first key exchange is also
5138 * the session id, used in session key construction and
5141 if (!s->got_session_id) {
5142 memcpy(ssh->v2_session_id, s->exchange_hash,
5143 sizeof(s->exchange_hash));
5144 s->got_session_id = TRUE;
5148 * Send SSH2_MSG_NEWKEYS.
5150 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
5151 ssh2_pkt_send_noqueue(ssh, s->pktout);
5152 ssh->outgoing_data_size = 0; /* start counting from here */
5155 * We've sent client NEWKEYS, so create and initialise
5156 * client-to-server session keys.
5158 if (ssh->cs_cipher_ctx)
5159 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
5160 ssh->cscipher = s->cscipher_tobe;
5161 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
5163 if (ssh->cs_mac_ctx)
5164 ssh->csmac->free_context(ssh->cs_mac_ctx);
5165 ssh->csmac = s->csmac_tobe;
5166 ssh->cs_mac_ctx = ssh->csmac->make_context();
5168 if (ssh->cs_comp_ctx)
5169 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
5170 ssh->cscomp = s->cscomp_tobe;
5171 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
5174 * Set IVs on client-to-server keys. Here we use the exchange
5175 * hash from the _first_ key exchange.
5178 unsigned char keyspace[40];
5179 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
5180 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
5181 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
5182 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
5183 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
5184 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
5187 logeventf(ssh, "Initialised %.200s client->server encryption",
5188 ssh->cscipher->text_name);
5189 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
5190 ssh->csmac->text_name);
5191 if (ssh->cscomp->text_name)
5192 logeventf(ssh, "Initialised %s compression",
5193 ssh->cscomp->text_name);
5196 * Now our end of the key exchange is complete, we can send all
5197 * our queued higher-layer packets.
5199 ssh->queueing = FALSE;
5200 ssh2_pkt_queuesend(ssh);
5203 * Expect SSH2_MSG_NEWKEYS from server.
5206 if (pktin->type != SSH2_MSG_NEWKEYS) {
5207 bombout(("expected new-keys packet from server"));
5210 ssh->incoming_data_size = 0; /* start counting from here */
5213 * We've seen server NEWKEYS, so create and initialise
5214 * server-to-client session keys.
5216 if (ssh->sc_cipher_ctx)
5217 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
5218 ssh->sccipher = s->sccipher_tobe;
5219 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
5221 if (ssh->sc_mac_ctx)
5222 ssh->scmac->free_context(ssh->sc_mac_ctx);
5223 ssh->scmac = s->scmac_tobe;
5224 ssh->sc_mac_ctx = ssh->scmac->make_context();
5226 if (ssh->sc_comp_ctx)
5227 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
5228 ssh->sccomp = s->sccomp_tobe;
5229 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
5232 * Set IVs on server-to-client keys. Here we use the exchange
5233 * hash from the _first_ key exchange.
5236 unsigned char keyspace[40];
5237 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
5238 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
5239 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
5240 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
5241 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
5242 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
5244 logeventf(ssh, "Initialised %.200s server->client encryption",
5245 ssh->sccipher->text_name);
5246 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
5247 ssh->scmac->text_name);
5248 if (ssh->sccomp->text_name)
5249 logeventf(ssh, "Initialised %s decompression",
5250 ssh->sccomp->text_name);
5253 * Free key exchange data.
5257 if (ssh->kex == &ssh_diffiehellman_gex) {
5263 * Key exchange is over. Loop straight back round if we have a
5264 * deferred rekey reason.
5266 if (ssh->deferred_rekey_reason) {
5267 logevent(ssh->deferred_rekey_reason);
5269 ssh->deferred_rekey_reason = NULL;
5270 goto begin_key_exchange;
5274 * Otherwise, schedule a timer for our next rekey.
5276 ssh->kex_in_progress = FALSE;
5277 ssh->last_rekey = GETTICKCOUNT();
5278 if (ssh->cfg.ssh_rekey_time != 0)
5279 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5283 * If this is the first key exchange phase, we must pass the
5284 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
5285 * wants to see it but because it will need time to initialise
5286 * itself before it sees an actual packet. In subsequent key
5287 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
5288 * it would only confuse the layer above.
5290 if (s->activated_authconn) {
5293 s->activated_authconn = TRUE;
5296 * Now we're encrypting. Begin returning 1 to the protocol main
5297 * function so that other things can run on top of the
5298 * transport. If we ever see a KEXINIT, we must go back to the
5301 * We _also_ go back to the start if we see pktin==NULL and
5302 * inlen==-1, because this is a special signal meaning
5303 * `initiate client-driven rekey', and `in' contains a message
5304 * giving the reason for the rekey.
5306 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
5307 (!pktin && inlen == -1))) {
5311 logevent("Server initiated key re-exchange");
5313 logevent((char *)in);
5315 goto begin_key_exchange;
5321 * Add data to an SSH2 channel output buffer.
5323 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
5326 bufchain_add(&c->v.v2.outbuffer, buf, len);
5330 * Attempt to send data on an SSH2 channel.
5332 static int ssh2_try_send(struct ssh_channel *c)
5335 struct Packet *pktout;
5337 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
5340 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
5341 if ((unsigned)len > c->v.v2.remwindow)
5342 len = c->v.v2.remwindow;
5343 if ((unsigned)len > c->v.v2.remmaxpkt)
5344 len = c->v.v2.remmaxpkt;
5345 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
5346 ssh2_pkt_adduint32(pktout, c->remoteid);
5347 dont_log_data(ssh, pktout, PKTLOG_OMIT);
5348 ssh2_pkt_addstring_start(pktout);
5349 ssh2_pkt_addstring_data(pktout, data, len);
5350 end_log_omission(ssh, pktout);
5351 ssh2_pkt_send(ssh, pktout);
5352 bufchain_consume(&c->v.v2.outbuffer, len);
5353 c->v.v2.remwindow -= len;
5357 * After having sent as much data as we can, return the amount
5360 return bufchain_size(&c->v.v2.outbuffer);
5364 * Potentially enlarge the window on an SSH2 channel.
5366 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
5371 * Never send WINDOW_ADJUST for a channel that the remote side
5372 * already thinks it's closed; there's no point, since it won't
5373 * be sending any more data anyway.
5378 if (newwin > c->v.v2.locwindow) {
5379 struct Packet *pktout;
5381 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5382 ssh2_pkt_adduint32(pktout, c->remoteid);
5383 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
5384 ssh2_pkt_send(ssh, pktout);
5385 c->v.v2.locwindow = newwin;
5389 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
5391 unsigned i = ssh_pkt_getuint32(pktin);
5392 struct ssh_channel *c;
5393 c = find234(ssh->channels, &i, ssh_channelfind);
5394 if (c && !c->closes)
5395 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
5398 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
5401 unsigned int length;
5402 unsigned i = ssh_pkt_getuint32(pktin);
5403 struct ssh_channel *c;
5404 c = find234(ssh->channels, &i, ssh_channelfind);
5406 return; /* nonexistent channel */
5407 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5408 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
5409 return; /* extended but not stderr */
5410 ssh_pkt_getstring(pktin, &data, &length);
5413 c->v.v2.locwindow -= length;
5415 case CHAN_MAINSESSION:
5417 from_backend(ssh->frontend, pktin->type ==
5418 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5422 bufsize = x11_send(c->u.x11.s, data, length);
5425 bufsize = pfd_send(c->u.pfd.s, data, length);
5428 while (length > 0) {
5429 if (c->u.a.lensofar < 4) {
5430 unsigned int l = min(4 - c->u.a.lensofar, length);
5431 memcpy(c->u.a.msglen + c->u.a.lensofar,
5435 c->u.a.lensofar += l;
5437 if (c->u.a.lensofar == 4) {
5439 4 + GET_32BIT(c->u.a.msglen);
5440 c->u.a.message = snewn(c->u.a.totallen,
5442 memcpy(c->u.a.message, c->u.a.msglen, 4);
5444 if (c->u.a.lensofar >= 4 && length > 0) {
5446 min(c->u.a.totallen - c->u.a.lensofar,
5448 memcpy(c->u.a.message + c->u.a.lensofar,
5452 c->u.a.lensofar += l;
5454 if (c->u.a.lensofar == c->u.a.totallen) {
5457 if (agent_query(c->u.a.message,
5460 ssh_agentf_callback, c))
5461 ssh_agentf_callback(c, reply, replylen);
5462 sfree(c->u.a.message);
5463 c->u.a.lensofar = 0;
5470 * If we are not buffering too much data,
5471 * enlarge the window again at the remote side.
5473 if (bufsize < OUR_V2_WINSIZE)
5474 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5478 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
5480 unsigned i = ssh_pkt_getuint32(pktin);
5481 struct ssh_channel *c;
5483 c = find234(ssh->channels, &i, ssh_channelfind);
5485 return; /* nonexistent channel */
5487 if (c->type == CHAN_X11) {
5489 * Remote EOF on an X11 channel means we should
5490 * wrap up and close the channel ourselves.
5492 x11_close(c->u.x11.s);
5494 } else if (c->type == CHAN_AGENT) {
5496 } else if (c->type == CHAN_SOCKDATA) {
5497 pfd_close(c->u.pfd.s);
5502 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
5504 unsigned i = ssh_pkt_getuint32(pktin);
5505 struct ssh_channel *c;
5506 struct Packet *pktout;
5508 c = find234(ssh->channels, &i, ssh_channelfind);
5509 if (!c || ((int)c->remoteid) == -1) {
5510 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5511 c ? "half-open" : "nonexistent", i));
5514 /* Do pre-close processing on the channel. */
5516 case CHAN_MAINSESSION:
5517 ssh->mainchan = NULL;
5518 update_specials_menu(ssh->frontend);
5521 if (c->u.x11.s != NULL)
5522 x11_close(c->u.x11.s);
5529 if (c->u.pfd.s != NULL)
5530 pfd_close(c->u.pfd.s);
5534 if (c->closes == 0) {
5535 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5536 ssh2_pkt_adduint32(pktout, c->remoteid);
5537 ssh2_pkt_send(ssh, pktout);
5539 del234(ssh->channels, c);
5540 bufchain_clear(&c->v.v2.outbuffer);
5544 * See if that was the last channel left open.
5545 * (This is only our termination condition if we're
5546 * not running in -N mode.)
5548 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
5549 logevent("All channels closed. Disconnecting");
5552 * We used to send SSH_MSG_DISCONNECT here,
5553 * because I'd believed that _every_ conforming
5554 * SSH2 connection had to end with a disconnect
5555 * being sent by at least one side; apparently
5556 * I was wrong and it's perfectly OK to
5557 * unceremoniously slam the connection shut
5558 * when you're done, and indeed OpenSSH feels
5559 * this is more polite than sending a
5560 * DISCONNECT. So now we don't.
5562 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5563 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
5564 ssh2_pkt_addstring(s->pktout, "All open channels closed");
5565 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
5566 ssh2_pkt_send_noqueue(ssh, s->pktout);
5568 ssh_closing((Plug)ssh, NULL, 0, 0);
5572 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5574 unsigned i = ssh_pkt_getuint32(pktin);
5575 struct ssh_channel *c;
5576 struct Packet *pktout;
5578 c = find234(ssh->channels, &i, ssh_channelfind);
5580 return; /* nonexistent channel */
5581 if (c->type != CHAN_SOCKDATA_DORMANT)
5582 return; /* dunno why they're confirming this */
5583 c->remoteid = ssh_pkt_getuint32(pktin);
5584 c->type = CHAN_SOCKDATA;
5585 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
5586 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
5588 pfd_confirm(c->u.pfd.s);
5591 * We have a pending close on this channel,
5592 * which we decided on before the server acked
5593 * the channel open. So now we know the
5594 * remoteid, we can close it again.
5596 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5597 ssh2_pkt_adduint32(pktout, c->remoteid);
5598 ssh2_pkt_send(ssh, pktout);
5602 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5604 static const char *const reasons[] = {
5605 "<unknown reason code>",
5606 "Administratively prohibited",
5608 "Unknown channel type",
5609 "Resource shortage",
5611 unsigned i = ssh_pkt_getuint32(pktin);
5612 unsigned reason_code;
5613 char *reason_string;
5616 struct ssh_channel *c;
5617 c = find234(ssh->channels, &i, ssh_channelfind);
5619 return; /* nonexistent channel */
5620 if (c->type != CHAN_SOCKDATA_DORMANT)
5621 return; /* dunno why they're failing this */
5623 reason_code = ssh_pkt_getuint32(pktin);
5624 if (reason_code >= lenof(reasons))
5625 reason_code = 0; /* ensure reasons[reason_code] in range */
5626 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
5627 message = dupprintf("Forwarded connection refused by"
5628 " server: %s [%.*s]", reasons[reason_code],
5629 reason_length, reason_string);
5633 pfd_close(c->u.pfd.s);
5635 del234(ssh->channels, c);
5639 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
5643 int typelen, want_reply;
5644 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
5645 struct ssh_channel *c;
5646 struct Packet *pktout;
5648 localid = ssh_pkt_getuint32(pktin);
5649 ssh_pkt_getstring(pktin, &type, &typelen);
5650 want_reply = ssh2_pkt_getbool(pktin);
5653 * First, check that the channel exists. Otherwise,
5654 * we can instantly disconnect with a rude message.
5656 c = find234(ssh->channels, &localid, ssh_channelfind);
5659 sprintf(buf, "Received channel request for nonexistent"
5660 " channel %d", localid);
5662 pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5663 ssh2_pkt_adduint32(pktout, SSH2_DISCONNECT_BY_APPLICATION);
5664 ssh2_pkt_addstring(pktout, buf);
5665 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5666 ssh2_pkt_send_noqueue(ssh, pktout);
5667 connection_fatal(ssh->frontend, "%s", buf);
5668 ssh_closing((Plug)ssh, NULL, 0, 0);
5673 * Having got the channel number, we now look at
5674 * the request type string to see if it's something
5677 if (c == ssh->mainchan) {
5679 * We recognise "exit-status" and "exit-signal" on
5680 * the primary channel.
5682 if (typelen == 11 &&
5683 !memcmp(type, "exit-status", 11)) {
5685 ssh->exitcode = ssh_pkt_getuint32(pktin);
5686 logeventf(ssh, "Server sent command exit status %d",
5688 reply = SSH2_MSG_CHANNEL_SUCCESS;
5690 } else if (typelen == 11 &&
5691 !memcmp(type, "exit-signal", 11)) {
5693 int is_plausible = TRUE, is_int = FALSE;
5694 char *fmt_sig = "", *fmt_msg = "";
5696 int msglen = 0, core = FALSE;
5697 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
5698 * provide an `int' for the signal, despite its
5699 * having been a `string' in the drafts since at
5700 * least 2001. (Fixed in session.c 1.147.) Try to
5701 * infer which we can safely parse it as. */
5703 unsigned char *p = pktin->body +
5705 long len = pktin->length - pktin->savedpos;
5706 unsigned long num = GET_32BIT(p); /* what is it? */
5707 /* If it's 0, it hardly matters; assume string */
5711 int maybe_int = FALSE, maybe_str = FALSE;
5712 #define CHECK_HYPOTHESIS(offset, result) \
5715 if (q >= 0 && q+4 <= len) { \
5716 q = q + 4 + GET_32BIT(p+q); \
5717 if (q >= 0 && q+4 <= len && \
5718 (q = q + 4 + GET_32BIT(p+q)) && q == len) \
5722 CHECK_HYPOTHESIS(4+1, maybe_int);
5723 CHECK_HYPOTHESIS(4+num+1, maybe_str);
5724 #undef CHECK_HYPOTHESIS
5725 if (maybe_int && !maybe_str)
5727 else if (!maybe_int && maybe_str)
5730 /* Crikey. Either or neither. Panic. */
5731 is_plausible = FALSE;
5736 /* Old non-standard OpenSSH. */
5737 int signum = ssh_pkt_getuint32(pktin);
5738 fmt_sig = dupprintf(" %d", signum);
5740 /* As per the drafts. */
5743 ssh_pkt_getstring(pktin, &sig, &siglen);
5744 /* Signal name isn't supposed to be blank, but
5745 * let's cope gracefully if it is. */
5747 fmt_sig = dupprintf(" \"%.*s\"",
5751 core = ssh2_pkt_getbool(pktin);
5752 ssh_pkt_getstring(pktin, &msg, &msglen);
5754 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
5756 /* ignore lang tag */
5757 } /* else don't attempt to parse */
5758 logeventf(ssh, "Server exited on signal%s%s%s",
5759 fmt_sig, core ? " (core dumped)" : "",
5761 if (*fmt_sig) sfree(fmt_sig);
5762 if (*fmt_msg) sfree(fmt_msg);
5763 reply = SSH2_MSG_CHANNEL_SUCCESS;
5768 * This is a channel request we don't know
5769 * about, so we now either ignore the request
5770 * or respond with CHANNEL_FAILURE, depending
5773 reply = SSH2_MSG_CHANNEL_FAILURE;
5776 pktout = ssh2_pkt_init(reply);
5777 ssh2_pkt_adduint32(pktout, c->remoteid);
5778 ssh2_pkt_send(ssh, pktout);
5782 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
5785 int typelen, want_reply;
5786 struct Packet *pktout;
5788 ssh_pkt_getstring(pktin, &type, &typelen);
5789 want_reply = ssh2_pkt_getbool(pktin);
5792 * We currently don't support any global requests
5793 * at all, so we either ignore the request or
5794 * respond with REQUEST_FAILURE, depending on
5798 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
5799 ssh2_pkt_send(ssh, pktout);
5803 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
5811 struct ssh_channel *c;
5812 unsigned remid, winsize, pktsize;
5813 struct Packet *pktout;
5815 ssh_pkt_getstring(pktin, &type, &typelen);
5816 c = snew(struct ssh_channel);
5819 remid = ssh_pkt_getuint32(pktin);
5820 winsize = ssh_pkt_getuint32(pktin);
5821 pktsize = ssh_pkt_getuint32(pktin);
5823 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5826 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5827 addrstr = snewn(peeraddrlen+1, char);
5828 memcpy(addrstr, peeraddr, peeraddrlen);
5829 addrstr[peeraddrlen] = '\0';
5830 peerport = ssh_pkt_getuint32(pktin);
5832 logeventf(ssh, "Received X11 connect request from %s:%d",
5835 if (!ssh->X11_fwd_enabled)
5836 error = "X11 forwarding is not enabled";
5837 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
5838 ssh->x11auth, addrstr, peerport,
5839 &ssh->cfg) != NULL) {
5840 error = "Unable to open an X11 connection";
5842 logevent("Opening X11 forward connection succeeded");
5847 } else if (typelen == 15 &&
5848 !memcmp(type, "forwarded-tcpip", 15)) {
5849 struct ssh_rportfwd pf, *realpf;
5852 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
5853 pf.sport = ssh_pkt_getuint32(pktin);
5854 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5855 peerport = ssh_pkt_getuint32(pktin);
5856 realpf = find234(ssh->rportfwds, &pf, NULL);
5857 logeventf(ssh, "Received remote port %d open request "
5858 "from %s:%d", pf.sport, peeraddr, peerport);
5859 if (realpf == NULL) {
5860 error = "Remote port is not recognised";
5862 const char *e = pfd_newconnect(&c->u.pfd.s,
5866 realpf->pfrec->addressfamily);
5867 logeventf(ssh, "Attempting to forward remote port to "
5868 "%s:%d", realpf->dhost, realpf->dport);
5870 logeventf(ssh, "Port open failed: %s", e);
5871 error = "Port open failed";
5873 logevent("Forwarded port opened successfully");
5874 c->type = CHAN_SOCKDATA;
5877 } else if (typelen == 22 &&
5878 !memcmp(type, "auth-agent@openssh.com", 3)) {
5879 if (!ssh->agentfwd_enabled)
5880 error = "Agent forwarding is not enabled";
5882 c->type = CHAN_AGENT; /* identify channel type */
5883 c->u.a.lensofar = 0;
5886 error = "Unsupported channel type requested";
5889 c->remoteid = remid;
5891 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
5892 ssh2_pkt_adduint32(pktout, c->remoteid);
5893 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
5894 ssh2_pkt_addstring(pktout, error);
5895 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5896 ssh2_pkt_send(ssh, pktout);
5897 logeventf(ssh, "Rejected channel open: %s", error);
5900 c->localid = alloc_channel_id(ssh);
5902 c->v.v2.locwindow = OUR_V2_WINSIZE;
5903 c->v.v2.remwindow = winsize;
5904 c->v.v2.remmaxpkt = pktsize;
5905 bufchain_init(&c->v.v2.outbuffer);
5906 add234(ssh->channels, c);
5907 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5908 ssh2_pkt_adduint32(pktout, c->remoteid);
5909 ssh2_pkt_adduint32(pktout, c->localid);
5910 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
5911 ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
5912 ssh2_pkt_send(ssh, pktout);
5917 * Handle the SSH2 userauth and connection layers.
5919 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
5920 struct Packet *pktin)
5922 struct do_ssh2_authconn_state {
5924 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
5926 AUTH_KEYBOARD_INTERACTIVE
5930 AUTH_TYPE_PUBLICKEY,
5931 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
5932 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
5934 AUTH_TYPE_KEYBOARD_INTERACTIVE,
5935 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
5937 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
5938 int tried_pubkey_config, tried_agent;
5939 int kbd_inter_running, kbd_inter_refused;
5941 int num_prompts, curr_prompt, echo;
5946 void *publickey_blob;
5947 int publickey_bloblen;
5948 unsigned char request[5], *response, *p;
5952 char *pkblob, *alg, *commentp;
5953 int pklen, alglen, commentlen;
5954 int siglen, retlen, len;
5955 char *q, *agentreq, *ret;
5957 int num_env, env_left, env_ok;
5958 struct Packet *pktout;
5960 crState(do_ssh2_authconn_state);
5962 crBegin(ssh->do_ssh2_authconn_crstate);
5965 * Request userauth protocol, and await a response to it.
5967 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
5968 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
5969 ssh2_pkt_send(ssh, s->pktout);
5970 crWaitUntilV(pktin);
5971 if (pktin->type != SSH2_MSG_SERVICE_ACCEPT) {
5972 bombout(("Server refused user authentication protocol"));
5977 * We repeat this whole loop, including the username prompt,
5978 * until we manage a successful authentication. If the user
5979 * types the wrong _password_, they can be sent back to the
5980 * beginning to try another username, if this is configured on.
5981 * (If they specify a username in the config, they are never
5982 * asked, even if they do give a wrong password.)
5984 * I think this best serves the needs of
5986 * - the people who have no configuration, no keys, and just
5987 * want to try repeated (username,password) pairs until they
5988 * type both correctly
5990 * - people who have keys and configuration but occasionally
5991 * need to fall back to passwords
5993 * - people with a key held in Pageant, who might not have
5994 * logged in to a particular machine before; so they want to
5995 * type a username, and then _either_ their key will be
5996 * accepted, _or_ they will type a password. If they mistype
5997 * the username they will want to be able to get back and
6000 s->username[0] = '\0';
6001 s->got_username = FALSE;
6006 if (s->got_username && !ssh->cfg.change_username) {
6008 * We got a username last time round this loop, and
6009 * with change_username turned off we don't try to get
6012 } else if (!*ssh->cfg.username) {
6013 if (ssh_get_line && !ssh_getline_pw_only) {
6014 if (!ssh_get_line("login as: ",
6015 s->username, sizeof(s->username), FALSE)) {
6017 * get_line failed to get a username.
6020 logevent("No username provided. Abandoning session.");
6021 ssh_closing((Plug)ssh, NULL, 0, 0);
6025 int ret; /* need not be saved across crReturn */
6026 c_write_str(ssh, "login as: ");
6028 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
6030 crWaitUntilV(!pktin);
6031 ret = process_userpass_input(ssh, in, inlen);
6035 c_write_str(ssh, "\r\n");
6037 s->username[strcspn(s->username, "\n\r")] = '\0';
6040 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
6041 s->username[sizeof(s->username)-1] = '\0';
6042 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
6043 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
6044 c_write_str(ssh, stuff);
6048 s->got_username = TRUE;
6051 * Send an authentication request using method "none": (a)
6052 * just in case it succeeds, and (b) so that we know what
6053 * authentication methods we can usefully try next.
6055 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6057 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6058 ssh2_pkt_addstring(s->pktout, s->username);
6059 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
6060 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6061 ssh2_pkt_send(ssh, s->pktout);
6062 s->type = AUTH_TYPE_NONE;
6064 s->we_are_in = FALSE;
6066 s->tried_pubkey_config = FALSE;
6067 s->tried_agent = FALSE;
6068 s->kbd_inter_running = FALSE;
6069 s->kbd_inter_refused = FALSE;
6070 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
6071 if (!filename_is_null(ssh->cfg.keyfile)) {
6073 logeventf(ssh, "Reading private key file \"%.150s\"",
6074 filename_to_str(&ssh->cfg.keyfile));
6075 keytype = key_type(&ssh->cfg.keyfile);
6076 if (keytype == SSH_KEYTYPE_SSH2) {
6078 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
6079 &s->publickey_bloblen, NULL);
6082 logeventf(ssh, "Unable to use this key file (%s)",
6083 key_type_to_str(keytype));
6084 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6086 filename_to_str(&ssh->cfg.keyfile),
6087 key_type_to_str(keytype));
6088 c_write_str(ssh, msgbuf);
6090 s->publickey_blob = NULL;
6093 s->publickey_blob = NULL;
6097 * Wait for the result of the last authentication request.
6100 crWaitUntilV(pktin);
6101 while (pktin->type == SSH2_MSG_USERAUTH_BANNER) {
6105 * Don't show the banner if we're operating in
6106 * non-verbose non-interactive mode. (It's probably
6107 * a script, which means nobody will read the
6108 * banner _anyway_, and moreover the printing of
6109 * the banner will screw up processing on the
6110 * output of (say) plink.)
6112 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
6113 ssh_pkt_getstring(pktin, &banner, &size);
6115 c_write_untrusted(ssh, banner, size);
6117 crWaitUntilV(pktin);
6119 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
6120 logevent("Access granted");
6121 s->we_are_in = TRUE;
6125 if (s->kbd_inter_running &&
6126 pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
6128 * This is either a further set-of-prompts packet
6129 * in keyboard-interactive authentication, or it's
6130 * the same one and we came back here with `gotit'
6131 * set. In the former case, we must reset the
6132 * curr_prompt variable.
6136 } else if (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
6137 /* FIXME: perhaps we should support this? */
6138 bombout(("PASSWD_CHANGEREQ not yet supported"));
6140 } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
6141 bombout(("Strange packet received during authentication: type %d",
6149 * OK, we're now sitting on a USERAUTH_FAILURE message, so
6150 * we can look at the string in it and know what we can
6151 * helpfully try next.
6153 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
6156 ssh_pkt_getstring(pktin, &methods, &methlen);
6157 s->kbd_inter_running = FALSE;
6158 if (!ssh2_pkt_getbool(pktin)) {
6160 * We have received an unequivocal Access
6161 * Denied. This can translate to a variety of
6164 * - if we'd just tried "none" authentication,
6165 * it's not worth printing anything at all
6167 * - if we'd just tried a public key _offer_,
6168 * the message should be "Server refused our
6169 * key" (or no message at all if the key
6170 * came from Pageant)
6172 * - if we'd just tried anything else, the
6173 * message really should be "Access denied".
6175 * Additionally, if we'd just tried password
6176 * authentication, we should break out of this
6177 * whole loop so as to go back to the username
6178 * prompt (iff we're configured to allow
6179 * username change attempts).
6181 if (s->type == AUTH_TYPE_NONE) {
6183 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
6184 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
6185 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
6186 c_write_str(ssh, "Server refused our key\r\n");
6187 logevent("Server refused public key");
6188 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
6189 /* server declined keyboard-interactive; ignore */
6191 c_write_str(ssh, "Access denied\r\n");
6192 logevent("Access denied");
6193 if (s->type == AUTH_TYPE_PASSWORD &&
6194 ssh->cfg.change_username) {
6195 /* XXX perhaps we should allow
6196 * keyboard-interactive to do this too? */
6197 s->we_are_in = FALSE;
6202 c_write_str(ssh, "Further authentication required\r\n");
6203 logevent("Further authentication required");
6207 in_commasep_string("publickey", methods, methlen);
6209 in_commasep_string("password", methods, methlen);
6210 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
6211 in_commasep_string("keyboard-interactive", methods, methlen);
6215 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6219 * Most password/passphrase prompts will be
6220 * non-echoing, so we set this to 0 by default.
6221 * Exception is that some keyboard-interactive prompts
6222 * can be echoing, in which case we'll set this to 1.
6226 if (!s->method && s->can_pubkey &&
6227 agent_exists() && !s->tried_agent) {
6229 * Attempt public-key authentication using Pageant.
6234 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6235 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6237 s->tried_agent = TRUE;
6239 logevent("Pageant is running. Requesting keys.");
6241 /* Request the keys held by the agent. */
6242 PUT_32BIT(s->request, 1);
6243 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
6244 if (!agent_query(s->request, 5, &r, &s->responselen,
6245 ssh_agent_callback, ssh)) {
6249 bombout(("Unexpected data from server while"
6250 " waiting for agent response"));
6253 } while (pktin || inlen > 0);
6254 r = ssh->agent_response;
6255 s->responselen = ssh->agent_response_len;
6257 s->response = (unsigned char *) r;
6258 if (s->response && s->responselen >= 5 &&
6259 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
6260 s->p = s->response + 5;
6261 s->nkeys = GET_32BIT(s->p);
6265 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
6268 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
6273 sprintf(buf, "Trying Pageant key #%d", s->keyi);
6276 s->pklen = GET_32BIT(s->p);
6278 if (s->publickey_blob &&
6279 s->pklen == s->publickey_bloblen &&
6280 !memcmp(s->p, s->publickey_blob,
6281 s->publickey_bloblen)) {
6282 logevent("This key matches configured key file");
6283 s->tried_pubkey_config = 1;
6285 s->pkblob = (char *)s->p;
6287 s->alglen = GET_32BIT(s->pkblob);
6288 s->alg = s->pkblob + 4;
6289 s->commentlen = GET_32BIT(s->p);
6291 s->commentp = (char *)s->p;
6292 s->p += s->commentlen;
6293 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6294 ssh2_pkt_addstring(s->pktout, s->username);
6295 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6296 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6297 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6298 ssh2_pkt_addstring_start(s->pktout);
6299 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6300 ssh2_pkt_addstring_start(s->pktout);
6301 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6302 ssh2_pkt_send(ssh, s->pktout);
6304 crWaitUntilV(pktin);
6305 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6306 logevent("Key refused");
6310 if (flags & FLAG_VERBOSE) {
6311 c_write_str(ssh, "Authenticating with "
6313 c_write(ssh, s->commentp, s->commentlen);
6314 c_write_str(ssh, "\" from agent\r\n");
6318 * Server is willing to accept the key.
6319 * Construct a SIGN_REQUEST.
6321 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6322 ssh2_pkt_addstring(s->pktout, s->username);
6323 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6324 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6325 ssh2_pkt_addbool(s->pktout, TRUE);
6326 ssh2_pkt_addstring_start(s->pktout);
6327 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6328 ssh2_pkt_addstring_start(s->pktout);
6329 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6331 s->siglen = s->pktout->length - 5 + 4 + 20;
6332 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6334 s->len = 1; /* message type */
6335 s->len += 4 + s->pklen; /* key blob */
6336 s->len += 4 + s->siglen; /* data to sign */
6337 s->len += 4; /* flags */
6338 s->agentreq = snewn(4 + s->len, char);
6339 PUT_32BIT(s->agentreq, s->len);
6340 s->q = s->agentreq + 4;
6341 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
6342 PUT_32BIT(s->q, s->pklen);
6344 memcpy(s->q, s->pkblob, s->pklen);
6346 PUT_32BIT(s->q, s->siglen);
6348 /* Now the data to be signed... */
6349 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6350 PUT_32BIT(s->q, 20);
6353 memcpy(s->q, ssh->v2_session_id, 20);
6355 memcpy(s->q, s->pktout->data + 5,
6356 s->pktout->length - 5);
6357 s->q += s->pktout->length - 5;
6358 /* And finally the (zero) flags word. */
6360 if (!agent_query(s->agentreq, s->len + 4,
6362 ssh_agent_callback, ssh)) {
6366 bombout(("Unexpected data from server"
6367 " while waiting for agent"
6371 } while (pktin || inlen > 0);
6372 vret = ssh->agent_response;
6373 s->retlen = ssh->agent_response_len;
6378 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
6379 logevent("Sending Pageant's response");
6380 ssh2_add_sigblob(ssh, s->pktout,
6381 s->pkblob, s->pklen,
6383 GET_32BIT(s->ret + 5));
6384 ssh2_pkt_send(ssh, s->pktout);
6389 ("Pageant failed to answer challenge");
6400 if (!s->method && s->can_pubkey && s->publickey_blob
6401 && !s->tried_pubkey_config) {
6402 unsigned char *pub_blob;
6403 char *algorithm, *comment;
6406 s->tried_pubkey_config = TRUE;
6408 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6409 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6412 * Try the public key supplied in the configuration.
6414 * First, offer the public blob to see if the server is
6415 * willing to accept it.
6418 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
6423 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6424 ssh2_pkt_addstring(s->pktout, s->username);
6425 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6426 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6427 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6428 ssh2_pkt_addstring(s->pktout, algorithm);
6429 ssh2_pkt_addstring_start(s->pktout);
6430 ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob,
6432 ssh2_pkt_send(ssh, s->pktout);
6433 logevent("Offered public key");
6435 crWaitUntilV(pktin);
6436 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6438 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
6439 continue; /* key refused; give up on it */
6442 logevent("Offer of public key accepted");
6444 * Actually attempt a serious authentication using
6447 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
6448 sprintf(s->pwprompt,
6449 "Passphrase for key \"%.100s\": ",
6455 if (flags & FLAG_VERBOSE) {
6456 c_write_str(ssh, "Authenticating with public key \"");
6457 c_write_str(ssh, comment);
6458 c_write_str(ssh, "\"\r\n");
6460 s->method = AUTH_PUBLICKEY_FILE;
6464 if (!s->method && s->can_keyb_inter && !s->kbd_inter_refused) {
6465 s->method = AUTH_KEYBOARD_INTERACTIVE;
6466 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6468 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6469 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
6471 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6472 ssh2_pkt_addstring(s->pktout, s->username);
6473 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6474 ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); /* method */
6475 ssh2_pkt_addstring(s->pktout, ""); /* lang */
6476 ssh2_pkt_addstring(s->pktout, "");
6477 ssh2_pkt_send(ssh, s->pktout);
6479 crWaitUntilV(pktin);
6480 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
6481 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
6483 logevent("Keyboard-interactive authentication refused");
6484 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
6485 s->kbd_inter_refused = TRUE; /* don't try it again */
6489 s->kbd_inter_running = TRUE;
6493 if (s->kbd_inter_running) {
6494 s->method = AUTH_KEYBOARD_INTERACTIVE;
6495 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6497 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6498 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
6500 if (s->curr_prompt == 0) {
6502 * We've got a fresh USERAUTH_INFO_REQUEST.
6503 * Display header data, and start going through
6506 char *name, *inst, *lang;
6507 int name_len, inst_len, lang_len;
6509 ssh_pkt_getstring(pktin, &name, &name_len);
6510 ssh_pkt_getstring(pktin, &inst, &inst_len);
6511 ssh_pkt_getstring(pktin, &lang, &lang_len);
6513 c_write_untrusted(ssh, name, name_len);
6514 c_write_str(ssh, "\r\n");
6517 c_write_untrusted(ssh, inst, inst_len);
6518 c_write_str(ssh, "\r\n");
6520 s->num_prompts = ssh_pkt_getuint32(pktin);
6524 * If there are prompts remaining in the packet,
6525 * display one and get a response.
6527 if (s->curr_prompt < s->num_prompts) {
6531 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
6532 if (prompt_len > 0) {
6533 static const char trunc[] = "<prompt truncated>: ";
6534 static const int prlen = sizeof(s->pwprompt) -
6536 if (prompt_len > prlen) {
6537 memcpy(s->pwprompt, prompt, prlen);
6538 strcpy(s->pwprompt + prlen, trunc);
6540 memcpy(s->pwprompt, prompt, prompt_len);
6541 s->pwprompt[prompt_len] = '\0';
6545 "<server failed to send prompt>: ");
6547 s->echo = ssh2_pkt_getbool(pktin);
6553 if (!s->method && s->can_passwd) {
6554 s->method = AUTH_PASSWORD;
6555 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6556 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
6557 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
6564 if (!ssh_get_line(s->pwprompt, s->password,
6565 sizeof(s->password), TRUE)) {
6567 * get_line failed to get a password (for
6568 * example because one was supplied on the
6569 * command line which has already failed to
6572 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6573 ssh2_pkt_adduint32(s->pktout,SSH2_DISCONNECT_BY_APPLICATION);
6574 ssh2_pkt_addstring(s->pktout, "No more passwords available"
6576 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
6577 ssh2_pkt_send_noqueue(ssh, s->pktout);
6578 logevent("Unable to authenticate");
6579 connection_fatal(ssh->frontend,
6580 "Unable to authenticate");
6581 ssh_closing((Plug)ssh, NULL, 0, 0);
6585 int ret; /* need not be saved across crReturn */
6586 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
6589 setup_userpass_input(ssh, s->password,
6590 sizeof(s->password), s->echo);
6592 crWaitUntilV(!pktin);
6593 ret = process_userpass_input(ssh, in, inlen);
6597 c_write_str(ssh, "\r\n");
6601 if (s->method == AUTH_PUBLICKEY_FILE) {
6603 * We have our passphrase. Now try the actual authentication.
6605 struct ssh2_userkey *key;
6606 const char *error = NULL;
6608 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
6610 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
6611 if (key == SSH2_WRONG_PASSPHRASE) {
6612 c_write_str(ssh, "Wrong passphrase\r\n");
6613 s->tried_pubkey_config = FALSE;
6615 c_write_str(ssh, "Unable to load private key (");
6616 c_write_str(ssh, error);
6617 c_write_str(ssh, ")\r\n");
6618 s->tried_pubkey_config = TRUE;
6620 /* Send a spurious AUTH_NONE to return to the top. */
6621 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6622 ssh2_pkt_addstring(s->pktout, s->username);
6623 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6624 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6625 ssh2_pkt_send(ssh, s->pktout);
6626 s->type = AUTH_TYPE_NONE;
6628 unsigned char *pkblob, *sigblob, *sigdata;
6629 int pkblob_len, sigblob_len, sigdata_len;
6633 * We have loaded the private key and the server
6634 * has announced that it's willing to accept it.
6635 * Hallelujah. Generate a signature and send it.
6637 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6638 ssh2_pkt_addstring(s->pktout, s->username);
6639 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6640 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6641 ssh2_pkt_addbool(s->pktout, TRUE);
6642 ssh2_pkt_addstring(s->pktout, key->alg->name);
6643 pkblob = key->alg->public_blob(key->data, &pkblob_len);
6644 ssh2_pkt_addstring_start(s->pktout);
6645 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len);
6648 * The data to be signed is:
6652 * followed by everything so far placed in the
6655 sigdata_len = s->pktout->length - 5 + 4 + 20;
6656 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6658 sigdata = snewn(sigdata_len, unsigned char);
6660 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6661 PUT_32BIT(sigdata+p, 20);
6664 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
6665 memcpy(sigdata+p, s->pktout->data + 5,
6666 s->pktout->length - 5);
6667 p += s->pktout->length - 5;
6668 assert(p == sigdata_len);
6669 sigblob = key->alg->sign(key->data, (char *)sigdata,
6670 sigdata_len, &sigblob_len);
6671 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
6672 sigblob, sigblob_len);
6677 ssh2_pkt_send(ssh, s->pktout);
6678 s->type = AUTH_TYPE_PUBLICKEY;
6679 key->alg->freekey(key->data);
6681 } else if (s->method == AUTH_PASSWORD) {
6683 * We send the password packet lumped tightly together with
6684 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
6685 * string long enough to make the total length of the two
6686 * packets constant. This should ensure that a passive
6687 * listener doing traffic analyis can't work out the length
6690 * For this to work, we need an assumption about the
6691 * maximum length of the password packet. I think 256 is
6692 * pretty conservative. Anyone using a password longer than
6693 * that probably doesn't have much to worry about from
6694 * people who find out how long their password is!
6696 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6697 ssh2_pkt_addstring(s->pktout, s->username);
6698 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6699 ssh2_pkt_addstring(s->pktout, "password");
6700 ssh2_pkt_addbool(s->pktout, FALSE);
6701 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6702 ssh2_pkt_addstring(s->pktout, s->password);
6703 memset(s->password, 0, sizeof(s->password));
6704 end_log_omission(ssh, s->pktout);
6705 ssh2_pkt_defer(ssh, s->pktout);
6707 * We'll include a string that's an exact multiple of the
6708 * cipher block size. If the cipher is NULL for some
6709 * reason, we don't do this trick at all because we gain
6712 if (ssh->cscipher) {
6715 stringlen = (256 - ssh->deferred_len);
6716 stringlen += ssh->cscipher->blksize - 1;
6717 stringlen -= (stringlen % ssh->cscipher->blksize);
6720 * Temporarily disable actual compression,
6721 * so we can guarantee to get this string
6722 * exactly the length we want it. The
6723 * compression-disabling routine should
6724 * return an integer indicating how many
6725 * bytes we should adjust our string length
6729 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
6731 s->pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
6732 ssh2_pkt_addstring_start(s->pktout);
6733 for (i = 0; i < stringlen; i++) {
6734 char c = (char) random_byte();
6735 ssh2_pkt_addstring_data(s->pktout, &c, 1);
6737 ssh2_pkt_defer(ssh, s->pktout);
6739 ssh_pkt_defersend(ssh);
6740 logevent("Sent password");
6741 s->type = AUTH_TYPE_PASSWORD;
6742 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
6743 if (s->curr_prompt == 0) {
6744 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
6745 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
6747 if (s->need_pw) { /* only add pw if we just got one! */
6748 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6749 ssh2_pkt_addstring(s->pktout, s->password);
6750 memset(s->password, 0, sizeof(s->password));
6751 end_log_omission(ssh, s->pktout);
6754 if (s->curr_prompt >= s->num_prompts) {
6755 ssh2_pkt_send(ssh, s->pktout);
6758 * If there are prompts remaining, we set
6759 * `gotit' so that we won't attempt to get
6760 * another packet. Then we go back round the
6761 * loop and will end up retrieving another
6762 * prompt out of the existing packet. Funky or
6767 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6769 c_write_str(ssh, "No supported authentication methods"
6770 " left to try!\r\n");
6771 logevent("No supported authentications offered."
6773 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6774 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
6775 ssh2_pkt_addstring(s->pktout, "No supported authentication"
6776 " methods available");
6777 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
6778 ssh2_pkt_send_noqueue(ssh, s->pktout);
6779 ssh_closing((Plug)ssh, NULL, 0, 0);
6783 } while (!s->we_are_in);
6786 * Now we're authenticated for the connection protocol. The
6787 * connection protocol will automatically have started at this
6788 * point; there's no need to send SERVICE_REQUEST.
6791 ssh->channels = newtree234(ssh_channelcmp);
6794 * Set up handlers for some connection protocol messages, so we
6795 * don't have to handle them repeatedly in this coroutine.
6797 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
6798 ssh2_msg_channel_window_adjust;
6799 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
6800 ssh2_msg_global_request;
6803 * Create the main session channel.
6805 if (!ssh->cfg.ssh_no_shell) {
6806 ssh->mainchan = snew(struct ssh_channel);
6807 ssh->mainchan->ssh = ssh;
6808 ssh->mainchan->localid = alloc_channel_id(ssh);
6809 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
6810 ssh2_pkt_addstring(s->pktout, "session");
6811 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
6812 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
6813 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
6814 ssh2_pkt_adduint32(s->pktout, 0x4000UL); /* our max pkt size */
6815 ssh2_pkt_send(ssh, s->pktout);
6816 crWaitUntilV(pktin);
6817 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
6818 bombout(("Server refused to open a session"));
6820 /* FIXME: error data comes back in FAILURE packet */
6822 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
6823 bombout(("Server's channel confirmation cited wrong channel"));
6826 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
6827 ssh->mainchan->type = CHAN_MAINSESSION;
6828 ssh->mainchan->closes = 0;
6829 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6830 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
6831 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
6832 add234(ssh->channels, ssh->mainchan);
6833 update_specials_menu(ssh->frontend);
6834 logevent("Opened channel for session");
6836 ssh->mainchan = NULL;
6839 * Now we have a channel, make dispatch table entries for
6840 * general channel-based messages.
6842 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
6843 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
6844 ssh2_msg_channel_data;
6845 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
6846 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
6847 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
6848 ssh2_msg_channel_open_confirmation;
6849 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
6850 ssh2_msg_channel_open_failure;
6851 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
6852 ssh2_msg_channel_request;
6853 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
6854 ssh2_msg_channel_open;
6857 * Potentially enable X11 forwarding.
6859 if (ssh->mainchan && ssh->cfg.x11_forward) {
6860 char proto[20], data[64];
6861 logevent("Requesting X11 forwarding");
6862 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
6863 data, sizeof(data), ssh->cfg.x11_auth);
6864 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
6865 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6866 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6867 ssh2_pkt_addstring(s->pktout, "x11-req");
6868 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6869 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
6870 ssh2_pkt_addstring(s->pktout, proto);
6871 ssh2_pkt_addstring(s->pktout, data);
6872 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
6873 ssh2_pkt_send(ssh, s->pktout);
6875 crWaitUntilV(pktin);
6877 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6878 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6879 bombout(("Unexpected response to X11 forwarding request:"
6880 " packet type %d", pktin->type));
6883 logevent("X11 forwarding refused");
6885 logevent("X11 forwarding enabled");
6886 ssh->X11_fwd_enabled = TRUE;
6891 * Enable port forwardings.
6893 ssh_setup_portfwd(ssh, &ssh->cfg);
6896 * Potentially enable agent forwarding.
6898 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
6899 logevent("Requesting OpenSSH-style agent forwarding");
6900 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6901 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6902 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
6903 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6904 ssh2_pkt_send(ssh, s->pktout);
6906 crWaitUntilV(pktin);
6908 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6909 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6910 bombout(("Unexpected response to agent forwarding request:"
6911 " packet type %d", pktin->type));
6914 logevent("Agent forwarding refused");
6916 logevent("Agent forwarding enabled");
6917 ssh->agentfwd_enabled = TRUE;
6922 * Now allocate a pty for the session.
6924 if (ssh->mainchan && !ssh->cfg.nopty) {
6925 /* Unpick the terminal-speed string. */
6926 /* XXX perhaps we should allow no speeds to be sent. */
6927 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
6928 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
6929 /* Build the pty request. */
6930 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6931 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
6932 ssh2_pkt_addstring(s->pktout, "pty-req");
6933 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6934 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
6935 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
6936 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
6937 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
6938 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
6939 ssh2_pkt_addstring_start(s->pktout);
6940 ssh2_pkt_addbyte(s->pktout, 128); /* TTY_OP_ISPEED */
6941 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
6942 ssh2_pkt_addbyte(s->pktout, 129); /* TTY_OP_OSPEED */
6943 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
6944 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
6945 ssh2_pkt_send(ssh, s->pktout);
6946 ssh->state = SSH_STATE_INTERMED;
6948 crWaitUntilV(pktin);
6950 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6951 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6952 bombout(("Unexpected response to pty request:"
6953 " packet type %d", pktin->type));
6956 c_write_str(ssh, "Server refused to allocate pty\r\n");
6957 ssh->editing = ssh->echoing = 1;
6959 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
6960 ssh->ospeed, ssh->ispeed);
6963 ssh->editing = ssh->echoing = 1;
6967 * Send environment variables.
6969 * Simplest thing here is to send all the requests at once, and
6970 * then wait for a whole bunch of successes or failures.
6972 if (ssh->mainchan && *ssh->cfg.environmt) {
6973 char *e = ssh->cfg.environmt;
6974 char *var, *varend, *val;
6980 while (*e && *e != '\t') e++;
6982 if (*e == '\t') e++;
6987 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6988 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6989 ssh2_pkt_addstring(s->pktout, "env");
6990 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6991 ssh2_pkt_addstring_start(s->pktout);
6992 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
6993 ssh2_pkt_addstring(s->pktout, val);
6994 ssh2_pkt_send(ssh, s->pktout);
6999 logeventf(ssh, "Sent %d environment variables", s->num_env);
7002 s->env_left = s->num_env;
7004 while (s->env_left > 0) {
7005 crWaitUntilV(pktin);
7007 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7008 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7009 bombout(("Unexpected response to environment request:"
7010 " packet type %d", pktin->type));
7020 if (s->env_ok == s->num_env) {
7021 logevent("All environment variables successfully set");
7022 } else if (s->env_ok == 0) {
7023 logevent("All environment variables refused");
7024 c_write_str(ssh, "Server refused to set environment variables\r\n");
7026 logeventf(ssh, "%d environment variables refused",
7027 s->num_env - s->env_ok);
7028 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7033 * Start a shell or a remote command. We may have to attempt
7034 * this twice if the config data has provided a second choice
7037 if (ssh->mainchan) while (1) {
7041 if (ssh->fallback_cmd) {
7042 subsys = ssh->cfg.ssh_subsys2;
7043 cmd = ssh->cfg.remote_cmd_ptr2;
7045 subsys = ssh->cfg.ssh_subsys;
7046 cmd = ssh->cfg.remote_cmd_ptr;
7049 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7050 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
7052 ssh2_pkt_addstring(s->pktout, "subsystem");
7053 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7054 ssh2_pkt_addstring(s->pktout, cmd);
7056 ssh2_pkt_addstring(s->pktout, "exec");
7057 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7058 ssh2_pkt_addstring(s->pktout, cmd);
7060 ssh2_pkt_addstring(s->pktout, "shell");
7061 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7063 ssh2_pkt_send(ssh, s->pktout);
7065 crWaitUntilV(pktin);
7067 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7068 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7069 bombout(("Unexpected response to shell/command request:"
7070 " packet type %d", pktin->type));
7074 * We failed to start the command. If this is the
7075 * fallback command, we really are finished; if it's
7076 * not, and if the fallback command exists, try falling
7077 * back to it before complaining.
7079 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
7080 logevent("Primary command failed; attempting fallback");
7081 ssh->fallback_cmd = TRUE;
7084 bombout(("Server refused to start a shell/command"));
7087 logevent("Started a shell/command");
7092 ssh->state = SSH_STATE_SESSION;
7093 if (ssh->size_needed)
7094 ssh_size(ssh, ssh->term_width, ssh->term_height);
7095 if (ssh->eof_needed)
7096 ssh_special(ssh, TS_EOF);
7102 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
7107 s->try_send = FALSE;
7111 * _All_ the connection-layer packets we expect to
7112 * receive are now handled by the dispatch table.
7113 * Anything that reaches here must be bogus.
7116 bombout(("Strange packet received: type %d", pktin->type));
7118 } else if (ssh->mainchan) {
7120 * We have spare data. Add it to the channel buffer.
7122 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
7127 struct ssh_channel *c;
7129 * Try to send data on all channels if we can.
7131 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
7134 continue; /* don't send on closing channels */
7135 bufsize = ssh2_try_send(c);
7138 case CHAN_MAINSESSION:
7139 /* stdin need not receive an unthrottle
7140 * notification since it will be polled */
7143 x11_unthrottle(c->u.x11.s);
7146 /* agent sockets are request/response and need no
7147 * buffer management */
7150 pfd_unthrottle(c->u.pfd.s);
7162 * Handlers for SSH2 messages that might arrive at any moment.
7164 void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
7166 /* log reason code in disconnect message */
7168 int nowlen, reason, msglen;
7170 reason = ssh_pkt_getuint32(pktin);
7171 ssh_pkt_getstring(pktin, &msg, &msglen);
7173 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
7174 buf = dupprintf("Received disconnect message (%s)",
7175 ssh2_disconnect_reasons[reason]);
7177 buf = dupprintf("Received disconnect message (unknown"
7178 " type %d)", reason);
7182 buf = dupprintf("Disconnection message text: %n%.*s",
7183 &nowlen, msglen, msg);
7185 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
7187 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
7188 ssh2_disconnect_reasons[reason] : "unknown",
7193 void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
7195 /* log the debug message */
7200 /* XXX maybe we should actually take notice of this */
7201 always_display = ssh2_pkt_getbool(pktin);
7202 ssh_pkt_getstring(pktin, &msg, &msglen);
7204 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
7209 void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
7211 struct Packet *pktout;
7212 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
7213 ssh2_pkt_adduint32(pktout, pktin->sequence);
7215 * UNIMPLEMENTED messages MUST appear in the same order as the
7216 * messages they respond to. Hence, never queue them.
7218 ssh2_pkt_send_noqueue(ssh, pktout);
7222 * Handle the top-level SSH2 protocol.
7224 static void ssh2_protocol_setup(Ssh ssh)
7229 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
7231 for (i = 0; i < 256; i++)
7232 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
7235 * Any message we actually understand, we set to NULL so that
7236 * the coroutines will get it.
7238 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
7239 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
7240 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
7241 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
7242 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
7243 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
7244 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
7245 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
7246 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
7247 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
7248 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
7249 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
7250 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
7251 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
7252 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7253 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
7254 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
7255 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
7256 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
7257 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
7258 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
7259 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
7260 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
7261 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
7262 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
7263 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
7264 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
7265 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
7266 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
7267 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
7268 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
7269 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
7270 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
7273 * These special message types we install handlers for.
7275 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
7276 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with ssh1 */
7277 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
7280 static void ssh2_timer(void *ctx, long now)
7284 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
7285 now - ssh->next_rekey >= 0) {
7286 do_ssh2_transport(ssh, "Initiating key re-exchange (timeout)",
7291 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
7292 struct Packet *pktin)
7294 if (ssh->state == SSH_STATE_CLOSED)
7298 ssh->incoming_data_size += pktin->encrypted_len;
7299 if (!ssh->kex_in_progress &&
7300 ssh->max_data_size != 0 &&
7301 ssh->incoming_data_size > ssh->max_data_size)
7302 do_ssh2_transport(ssh, "Initiating key re-exchange "
7303 "(too much data received)", -1, NULL);
7306 if (pktin && ssh->packet_dispatch[pktin->type]) {
7307 ssh->packet_dispatch[pktin->type](ssh, pktin);
7311 if (!ssh->protocol_initial_phase_done ||
7312 (pktin && pktin->type >= 20 && pktin->type < 50)) {
7313 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
7314 !ssh->protocol_initial_phase_done) {
7315 ssh->protocol_initial_phase_done = TRUE;
7317 * Allow authconn to initialise itself.
7319 do_ssh2_authconn(ssh, NULL, 0, NULL);
7322 do_ssh2_authconn(ssh, in, inlen, pktin);
7327 * Called to set up the connection.
7329 * Returns an error message, or NULL on success.
7331 static const char *ssh_init(void *frontend_handle, void **backend_handle,
7333 char *host, int port, char **realhost, int nodelay,
7339 ssh = snew(struct ssh_tag);
7340 ssh->cfg = *cfg; /* STRUCTURE COPY */
7341 ssh->version = 0; /* when not ready yet */
7344 ssh->v1_cipher_ctx = NULL;
7345 ssh->crcda_ctx = NULL;
7346 ssh->cscipher = NULL;
7347 ssh->cs_cipher_ctx = NULL;
7348 ssh->sccipher = NULL;
7349 ssh->sc_cipher_ctx = NULL;
7351 ssh->cs_mac_ctx = NULL;
7353 ssh->sc_mac_ctx = NULL;
7355 ssh->cs_comp_ctx = NULL;
7357 ssh->sc_comp_ctx = NULL;
7359 ssh->kex_ctx = NULL;
7360 ssh->hostkey = NULL;
7362 ssh->state = SSH_STATE_PREPACKET;
7363 ssh->size_needed = FALSE;
7364 ssh->eof_needed = FALSE;
7367 ssh->deferred_send_data = NULL;
7368 ssh->deferred_len = 0;
7369 ssh->deferred_size = 0;
7370 ssh->fallback_cmd = 0;
7372 ssh->x11auth = NULL;
7373 ssh->v1_compressing = FALSE;
7374 ssh->v2_outgoing_sequence = 0;
7375 ssh->ssh1_rdpkt_crstate = 0;
7376 ssh->ssh2_rdpkt_crstate = 0;
7377 ssh->do_ssh_init_crstate = 0;
7378 ssh->ssh_gotdata_crstate = 0;
7379 ssh->do_ssh1_connection_crstate = 0;
7380 ssh->do_ssh1_login_crstate = 0;
7381 ssh->do_ssh2_transport_crstate = 0;
7382 ssh->do_ssh2_authconn_crstate = 0;
7383 ssh->do_ssh_init_state = NULL;
7384 ssh->do_ssh1_login_state = NULL;
7385 ssh->do_ssh2_transport_state = NULL;
7386 ssh->do_ssh2_authconn_state = NULL;
7387 ssh->mainchan = NULL;
7388 ssh->throttled_all = 0;
7389 ssh->v1_stdout_throttling = 0;
7391 ssh->queuelen = ssh->queuesize = 0;
7392 ssh->queueing = FALSE;
7393 ssh->qhead = ssh->qtail = NULL;
7394 ssh->deferred_rekey_reason = NULL;
7396 *backend_handle = ssh;
7399 if (crypto_startup() == 0)
7400 return "Microsoft high encryption pack not installed!";
7403 ssh->frontend = frontend_handle;
7404 ssh->term_width = ssh->cfg.width;
7405 ssh->term_height = ssh->cfg.height;
7407 ssh->channels = NULL;
7408 ssh->rportfwds = NULL;
7409 ssh->portfwds = NULL;
7414 ssh->v1_throttle_count = 0;
7415 ssh->overall_bufsize = 0;
7416 ssh->fallback_cmd = 0;
7418 ssh->protocol = NULL;
7420 ssh->protocol_initial_phase_done = FALSE;
7424 ssh->incoming_data_size = ssh->outgoing_data_size =
7425 ssh->deferred_data_size = 0L;
7426 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
7427 ssh->kex_in_progress = FALSE;
7429 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
7438 static void ssh_free(void *handle)
7440 Ssh ssh = (Ssh) handle;
7441 struct ssh_channel *c;
7442 struct ssh_rportfwd *pf;
7444 if (ssh->v1_cipher_ctx)
7445 ssh->cipher->free_context(ssh->v1_cipher_ctx);
7446 if (ssh->cs_cipher_ctx)
7447 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7448 if (ssh->sc_cipher_ctx)
7449 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7450 if (ssh->cs_mac_ctx)
7451 ssh->csmac->free_context(ssh->cs_mac_ctx);
7452 if (ssh->sc_mac_ctx)
7453 ssh->scmac->free_context(ssh->sc_mac_ctx);
7454 if (ssh->cs_comp_ctx) {
7456 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7458 zlib_compress_cleanup(ssh->cs_comp_ctx);
7460 if (ssh->sc_comp_ctx) {
7462 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7464 zlib_decompress_cleanup(ssh->sc_comp_ctx);
7467 dh_cleanup(ssh->kex_ctx);
7468 sfree(ssh->savedhost);
7470 while (ssh->queuelen-- > 0)
7471 ssh_free_packet(ssh->queue[ssh->queuelen]);
7474 while (ssh->qhead) {
7475 struct queued_handler *qh = ssh->qhead;
7476 ssh->qhead = qh->next;
7479 ssh->qhead = ssh->qtail = NULL;
7481 if (ssh->channels) {
7482 while ((c = delpos234(ssh->channels, 0)) != NULL) {
7485 if (c->u.x11.s != NULL)
7486 x11_close(c->u.x11.s);
7489 if (c->u.pfd.s != NULL)
7490 pfd_close(c->u.pfd.s);
7495 freetree234(ssh->channels);
7496 ssh->channels = NULL;
7499 if (ssh->rportfwds) {
7500 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
7502 freetree234(ssh->rportfwds);
7503 ssh->rportfwds = NULL;
7505 sfree(ssh->deferred_send_data);
7507 x11_free_auth(ssh->x11auth);
7508 sfree(ssh->do_ssh_init_state);
7509 sfree(ssh->do_ssh1_login_state);
7510 sfree(ssh->do_ssh2_transport_state);
7511 sfree(ssh->do_ssh2_authconn_state);
7512 if (ssh->crcda_ctx) {
7513 crcda_free_context(ssh->crcda_ctx);
7514 ssh->crcda_ctx = NULL;
7518 expire_timer_context(ssh);
7520 pinger_free(ssh->pinger);
7527 * Reconfigure the SSH backend.
7529 static void ssh_reconfig(void *handle, Config *cfg)
7531 Ssh ssh = (Ssh) handle;
7532 char *rekeying = NULL, rekey_mandatory = FALSE;
7533 unsigned long old_max_data_size;
7535 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
7536 ssh_setup_portfwd(ssh, cfg);
7538 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
7539 cfg->ssh_rekey_time != 0) {
7540 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
7541 long now = GETTICKCOUNT();
7543 if (new_next - now < 0) {
7544 rekeying = "Initiating key re-exchange (timeout shortened)";
7546 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
7550 old_max_data_size = ssh->max_data_size;
7551 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
7552 if (old_max_data_size != ssh->max_data_size &&
7553 ssh->max_data_size != 0) {
7554 if (ssh->outgoing_data_size > ssh->max_data_size ||
7555 ssh->incoming_data_size > ssh->max_data_size)
7556 rekeying = "Initiating key re-exchange (data limit lowered)";
7559 if (ssh->cfg.compression != cfg->compression) {
7560 rekeying = "Initiating key re-exchange (compression setting changed)";
7561 rekey_mandatory = TRUE;
7564 if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
7565 memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
7566 sizeof(ssh->cfg.ssh_cipherlist))) {
7567 rekeying = "Initiating key re-exchange (cipher settings changed)";
7568 rekey_mandatory = TRUE;
7571 ssh->cfg = *cfg; /* STRUCTURE COPY */
7574 if (!ssh->kex_in_progress) {
7575 do_ssh2_transport(ssh, rekeying, -1, NULL);
7576 } else if (rekey_mandatory) {
7577 ssh->deferred_rekey_reason = rekeying;
7583 * Called to send data down the Telnet connection.
7585 static int ssh_send(void *handle, char *buf, int len)
7587 Ssh ssh = (Ssh) handle;
7589 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
7592 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
7594 return ssh_sendbuffer(ssh);
7598 * Called to query the current amount of buffered stdin data.
7600 static int ssh_sendbuffer(void *handle)
7602 Ssh ssh = (Ssh) handle;
7605 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
7609 * If the SSH socket itself has backed up, add the total backup
7610 * size on that to any individual buffer on the stdin channel.
7613 if (ssh->throttled_all)
7614 override_value = ssh->overall_bufsize;
7616 if (ssh->version == 1) {
7617 return override_value;
7618 } else if (ssh->version == 2) {
7619 if (!ssh->mainchan || ssh->mainchan->closes > 0)
7620 return override_value;
7622 return (override_value +
7623 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
7630 * Called to set the size of the window from SSH's POV.
7632 static void ssh_size(void *handle, int width, int height)
7634 Ssh ssh = (Ssh) handle;
7635 struct Packet *pktout;
7637 ssh->term_width = width;
7638 ssh->term_height = height;
7640 switch (ssh->state) {
7641 case SSH_STATE_BEFORE_SIZE:
7642 case SSH_STATE_PREPACKET:
7643 case SSH_STATE_CLOSED:
7644 break; /* do nothing */
7645 case SSH_STATE_INTERMED:
7646 ssh->size_needed = TRUE; /* buffer for later */
7648 case SSH_STATE_SESSION:
7649 if (!ssh->cfg.nopty) {
7650 if (ssh->version == 1) {
7651 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
7652 PKT_INT, ssh->term_height,
7653 PKT_INT, ssh->term_width,
7654 PKT_INT, 0, PKT_INT, 0, PKT_END);
7655 } else if (ssh->mainchan) {
7656 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7657 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7658 ssh2_pkt_addstring(pktout, "window-change");
7659 ssh2_pkt_addbool(pktout, 0);
7660 ssh2_pkt_adduint32(pktout, ssh->term_width);
7661 ssh2_pkt_adduint32(pktout, ssh->term_height);
7662 ssh2_pkt_adduint32(pktout, 0);
7663 ssh2_pkt_adduint32(pktout, 0);
7664 ssh2_pkt_send(ssh, pktout);
7672 * Return a list of the special codes that make sense in this
7675 static const struct telnet_special *ssh_get_specials(void *handle)
7677 static const struct telnet_special ssh1_ignore_special[] = {
7678 {"IGNORE message", TS_NOP}
7680 static const struct telnet_special ssh2_transport_specials[] = {
7681 {"IGNORE message", TS_NOP},
7682 {"Repeat key exchange", TS_REKEY},
7684 static const struct telnet_special ssh2_session_specials[] = {
7687 /* These are the signal names defined by draft-ietf-secsh-connect-23.
7688 * They include all the ISO C signals, but are a subset of the POSIX
7689 * required signals. */
7690 {"SIGINT (Interrupt)", TS_SIGINT},
7691 {"SIGTERM (Terminate)", TS_SIGTERM},
7692 {"SIGKILL (Kill)", TS_SIGKILL},
7693 {"SIGQUIT (Quit)", TS_SIGQUIT},
7694 {"SIGHUP (Hangup)", TS_SIGHUP},
7695 {"More signals", TS_SUBMENU},
7696 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
7697 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
7698 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
7699 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
7702 static const struct telnet_special specials_end[] = {
7705 /* XXX review this length for any changes: */
7706 static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
7707 lenof(ssh2_session_specials) +
7708 lenof(specials_end)];
7709 Ssh ssh = (Ssh) handle;
7711 #define ADD_SPECIALS(name) \
7713 assert((i + lenof(name)) <= lenof(ssh_specials)); \
7714 memcpy(&ssh_specials[i], name, sizeof name); \
7718 if (ssh->version == 1) {
7719 /* Don't bother offering IGNORE if we've decided the remote
7720 * won't cope with it, since we wouldn't bother sending it if
7722 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7723 ADD_SPECIALS(ssh1_ignore_special);
7724 } else if (ssh->version == 2) {
7725 ADD_SPECIALS(ssh2_transport_specials);
7727 ADD_SPECIALS(ssh2_session_specials);
7728 } /* else we're not ready yet */
7731 ADD_SPECIALS(specials_end);
7732 return ssh_specials;
7740 * Send Telnet special codes. TS_EOF is useful for `plink', so you
7741 * can send an EOF and collect resulting output (e.g. `plink
7744 static void ssh_special(void *handle, Telnet_Special code)
7746 Ssh ssh = (Ssh) handle;
7747 struct Packet *pktout;
7749 if (code == TS_EOF) {
7750 if (ssh->state != SSH_STATE_SESSION) {
7752 * Buffer the EOF in case we are pre-SESSION, so we can
7753 * send it as soon as we reach SESSION.
7756 ssh->eof_needed = TRUE;
7759 if (ssh->version == 1) {
7760 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
7761 } else if (ssh->mainchan) {
7762 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
7763 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7764 ssh2_pkt_send(ssh, pktout);
7766 logevent("Sent EOF message");
7767 } else if (code == TS_PING || code == TS_NOP) {
7768 if (ssh->state == SSH_STATE_CLOSED
7769 || ssh->state == SSH_STATE_PREPACKET) return;
7770 if (ssh->version == 1) {
7771 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7772 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
7774 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
7775 ssh2_pkt_addstring_start(pktout);
7776 ssh2_pkt_send_noqueue(ssh, pktout);
7778 } else if (code == TS_REKEY) {
7779 if (!ssh->kex_in_progress && ssh->version == 2) {
7780 do_ssh2_transport(ssh, "Initiating key re-exchange at"
7781 " user request", -1, NULL);
7783 } else if (code == TS_BRK) {
7784 if (ssh->state == SSH_STATE_CLOSED
7785 || ssh->state == SSH_STATE_PREPACKET) return;
7786 if (ssh->version == 1) {
7787 logevent("Unable to send BREAK signal in SSH1");
7788 } else if (ssh->mainchan) {
7789 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7790 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7791 ssh2_pkt_addstring(pktout, "break");
7792 ssh2_pkt_addbool(pktout, 0);
7793 ssh2_pkt_adduint32(pktout, 0); /* default break length */
7794 ssh2_pkt_send(ssh, pktout);
7797 /* Is is a POSIX signal? */
7798 char *signame = NULL;
7799 if (code == TS_SIGABRT) signame = "ABRT";
7800 if (code == TS_SIGALRM) signame = "ALRM";
7801 if (code == TS_SIGFPE) signame = "FPE";
7802 if (code == TS_SIGHUP) signame = "HUP";
7803 if (code == TS_SIGILL) signame = "ILL";
7804 if (code == TS_SIGINT) signame = "INT";
7805 if (code == TS_SIGKILL) signame = "KILL";
7806 if (code == TS_SIGPIPE) signame = "PIPE";
7807 if (code == TS_SIGQUIT) signame = "QUIT";
7808 if (code == TS_SIGSEGV) signame = "SEGV";
7809 if (code == TS_SIGTERM) signame = "TERM";
7810 if (code == TS_SIGUSR1) signame = "USR1";
7811 if (code == TS_SIGUSR2) signame = "USR2";
7812 /* The SSH-2 protocol does in principle support arbitrary named
7813 * signals, including signame@domain, but we don't support those. */
7815 /* It's a signal. */
7816 if (ssh->version == 2 && ssh->mainchan) {
7817 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7818 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7819 ssh2_pkt_addstring(pktout, "signal");
7820 ssh2_pkt_addbool(pktout, 0);
7821 ssh2_pkt_addstring(pktout, signame);
7822 ssh2_pkt_send(ssh, pktout);
7823 logeventf(ssh, "Sent signal SIG%s", signame);
7826 /* Never heard of it. Do nothing */
7831 void *new_sock_channel(void *handle, Socket s)
7833 Ssh ssh = (Ssh) handle;
7834 struct ssh_channel *c;
7835 c = snew(struct ssh_channel);
7839 c->remoteid = -1; /* to be set when open confirmed */
7840 c->localid = alloc_channel_id(ssh);
7842 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
7844 bufchain_init(&c->v.v2.outbuffer);
7845 add234(ssh->channels, c);
7851 * This is called when stdout/stderr (the entity to which
7852 * from_backend sends data) manages to clear some backlog.
7854 static void ssh_unthrottle(void *handle, int bufsize)
7856 Ssh ssh = (Ssh) handle;
7857 if (ssh->version == 1) {
7858 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
7859 ssh->v1_stdout_throttling = 0;
7860 ssh1_throttle(ssh, -1);
7863 if (ssh->mainchan && ssh->mainchan->closes == 0)
7864 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
7868 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
7870 struct ssh_channel *c = (struct ssh_channel *)channel;
7872 struct Packet *pktout;
7874 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
7876 if (ssh->version == 1) {
7877 send_packet(ssh, SSH1_MSG_PORT_OPEN,
7878 PKT_INT, c->localid,
7881 /* PKT_STR, <org:orgport>, */
7884 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7885 ssh2_pkt_addstring(pktout, "direct-tcpip");
7886 ssh2_pkt_adduint32(pktout, c->localid);
7887 c->v.v2.locwindow = OUR_V2_WINSIZE;
7888 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7889 ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
7890 ssh2_pkt_addstring(pktout, hostname);
7891 ssh2_pkt_adduint32(pktout, port);
7893 * We make up values for the originator data; partly it's
7894 * too much hassle to keep track, and partly I'm not
7895 * convinced the server should be told details like that
7896 * about my local network configuration.
7898 ssh2_pkt_addstring(pktout, "client-side-connection");
7899 ssh2_pkt_adduint32(pktout, 0);
7900 ssh2_pkt_send(ssh, pktout);
7904 static Socket ssh_socket(void *handle)
7906 Ssh ssh = (Ssh) handle;
7910 static int ssh_sendok(void *handle)
7912 Ssh ssh = (Ssh) handle;
7913 return ssh->send_ok;
7916 static int ssh_ldisc(void *handle, int option)
7918 Ssh ssh = (Ssh) handle;
7919 if (option == LD_ECHO)
7920 return ssh->echoing;
7921 if (option == LD_EDIT)
7922 return ssh->editing;
7926 static void ssh_provide_ldisc(void *handle, void *ldisc)
7928 Ssh ssh = (Ssh) handle;
7932 static void ssh_provide_logctx(void *handle, void *logctx)
7934 Ssh ssh = (Ssh) handle;
7935 ssh->logctx = logctx;
7938 static int ssh_return_exitcode(void *handle)
7940 Ssh ssh = (Ssh) handle;
7944 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
7948 * cfg_info for SSH is the currently running version of the
7949 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
7951 static int ssh_cfg_info(void *handle)
7953 Ssh ssh = (Ssh) handle;
7954 return ssh->version;
7958 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
7959 * that fails. This variable is the means by which scp.c can reach
7960 * into the SSH code and find out which one it got.
7962 extern int ssh_fallback_cmd(void *handle)
7964 Ssh ssh = (Ssh) handle;
7965 return ssh->fallback_cmd;
7968 Backend ssh_backend = {
7978 ssh_return_exitcode,