17 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
18 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
19 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
20 #define SSH1_CMSG_USER 4 /* 0x4 */
21 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
22 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
23 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
24 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
25 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
26 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
27 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
28 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
29 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
30 #define SSH1_SMSG_FAILURE 15 /* 0xf */
31 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
32 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
33 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
34 #define SSH1_CMSG_EOF 19 /* 0x13 */
35 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
36 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
37 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
38 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
39 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
40 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
41 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
42 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
43 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
44 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
45 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
46 #define SSH1_MSG_IGNORE 32 /* 0x20 */
47 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
48 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
49 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
50 #define SSH1_MSG_DEBUG 36 /* 0x24 */
51 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
52 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
53 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
54 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
55 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
56 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
57 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
59 #define SSH1_AUTH_TIS 5 /* 0x5 */
60 #define SSH1_AUTH_CCARD 16 /* 0x10 */
62 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
63 /* Mask for protoflags we will echo back to server if seen */
64 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
66 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
67 #define SSH2_MSG_IGNORE 2 /* 0x2 */
68 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
69 #define SSH2_MSG_DEBUG 4 /* 0x4 */
70 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
71 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
72 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
73 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
74 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
75 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
76 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
77 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
78 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
79 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
80 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
81 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
82 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
83 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
84 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
85 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
86 #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
87 #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
88 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
89 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
90 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
91 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
92 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
93 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
94 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
95 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
96 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
97 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
98 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
99 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
100 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
101 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
104 * Packet type contexts, so that ssh2_pkt_type can correctly decode
105 * the ambiguous type numbers back into the correct type strings.
107 #define SSH2_PKTCTX_DHGROUP 0x0001
108 #define SSH2_PKTCTX_DHGEX 0x0002
109 #define SSH2_PKTCTX_KEX_MASK 0x000F
110 #define SSH2_PKTCTX_PUBLICKEY 0x0010
111 #define SSH2_PKTCTX_PASSWORD 0x0020
112 #define SSH2_PKTCTX_KBDINTER 0x0040
113 #define SSH2_PKTCTX_AUTH_MASK 0x00F0
115 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
116 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
117 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
118 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
119 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
120 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
121 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
122 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
123 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
124 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
125 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
126 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
127 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
128 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
129 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
131 static const char *const ssh2_disconnect_reasons[] = {
133 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
134 "SSH_DISCONNECT_PROTOCOL_ERROR",
135 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
136 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
137 "SSH_DISCONNECT_MAC_ERROR",
138 "SSH_DISCONNECT_COMPRESSION_ERROR",
139 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
140 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
141 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
142 "SSH_DISCONNECT_CONNECTION_LOST",
143 "SSH_DISCONNECT_BY_APPLICATION",
144 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
145 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
146 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
147 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
150 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
151 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
152 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
153 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
155 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
158 * Various remote-bug flags.
160 #define BUG_CHOKES_ON_SSH1_IGNORE 1
161 #define BUG_SSH2_HMAC 2
162 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
163 #define BUG_CHOKES_ON_RSA 8
164 #define BUG_SSH2_RSA_PADDING 16
165 #define BUG_SSH2_DERIVEKEY 32
166 #define BUG_SSH2_REKEY 64
167 #define BUG_SSH2_PK_SESSIONID 128
169 #define translate(x) if (type == x) return #x
170 #define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
171 static char *ssh1_pkt_type(int type)
173 translate(SSH1_MSG_DISCONNECT);
174 translate(SSH1_SMSG_PUBLIC_KEY);
175 translate(SSH1_CMSG_SESSION_KEY);
176 translate(SSH1_CMSG_USER);
177 translate(SSH1_CMSG_AUTH_RSA);
178 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
179 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
180 translate(SSH1_CMSG_AUTH_PASSWORD);
181 translate(SSH1_CMSG_REQUEST_PTY);
182 translate(SSH1_CMSG_WINDOW_SIZE);
183 translate(SSH1_CMSG_EXEC_SHELL);
184 translate(SSH1_CMSG_EXEC_CMD);
185 translate(SSH1_SMSG_SUCCESS);
186 translate(SSH1_SMSG_FAILURE);
187 translate(SSH1_CMSG_STDIN_DATA);
188 translate(SSH1_SMSG_STDOUT_DATA);
189 translate(SSH1_SMSG_STDERR_DATA);
190 translate(SSH1_CMSG_EOF);
191 translate(SSH1_SMSG_EXIT_STATUS);
192 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
193 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
194 translate(SSH1_MSG_CHANNEL_DATA);
195 translate(SSH1_MSG_CHANNEL_CLOSE);
196 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
197 translate(SSH1_SMSG_X11_OPEN);
198 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
199 translate(SSH1_MSG_PORT_OPEN);
200 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
201 translate(SSH1_SMSG_AGENT_OPEN);
202 translate(SSH1_MSG_IGNORE);
203 translate(SSH1_CMSG_EXIT_CONFIRMATION);
204 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
205 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
206 translate(SSH1_MSG_DEBUG);
207 translate(SSH1_CMSG_REQUEST_COMPRESSION);
208 translate(SSH1_CMSG_AUTH_TIS);
209 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
210 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
211 translate(SSH1_CMSG_AUTH_CCARD);
212 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
213 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
216 static char *ssh2_pkt_type(int pkt_ctx, int type)
218 translate(SSH2_MSG_DISCONNECT);
219 translate(SSH2_MSG_IGNORE);
220 translate(SSH2_MSG_UNIMPLEMENTED);
221 translate(SSH2_MSG_DEBUG);
222 translate(SSH2_MSG_SERVICE_REQUEST);
223 translate(SSH2_MSG_SERVICE_ACCEPT);
224 translate(SSH2_MSG_KEXINIT);
225 translate(SSH2_MSG_NEWKEYS);
226 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
227 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
228 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
229 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
230 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
231 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
232 translate(SSH2_MSG_USERAUTH_REQUEST);
233 translate(SSH2_MSG_USERAUTH_FAILURE);
234 translate(SSH2_MSG_USERAUTH_SUCCESS);
235 translate(SSH2_MSG_USERAUTH_BANNER);
236 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
237 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
238 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
239 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
240 translate(SSH2_MSG_GLOBAL_REQUEST);
241 translate(SSH2_MSG_REQUEST_SUCCESS);
242 translate(SSH2_MSG_REQUEST_FAILURE);
243 translate(SSH2_MSG_CHANNEL_OPEN);
244 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
245 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
246 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
247 translate(SSH2_MSG_CHANNEL_DATA);
248 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
249 translate(SSH2_MSG_CHANNEL_EOF);
250 translate(SSH2_MSG_CHANNEL_CLOSE);
251 translate(SSH2_MSG_CHANNEL_REQUEST);
252 translate(SSH2_MSG_CHANNEL_SUCCESS);
253 translate(SSH2_MSG_CHANNEL_FAILURE);
259 #define GET_32BIT(cp) \
260 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
261 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
262 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
263 ((unsigned long)(unsigned char)(cp)[3]))
265 #define PUT_32BIT(cp, value) { \
266 (cp)[0] = (unsigned char)((value) >> 24); \
267 (cp)[1] = (unsigned char)((value) >> 16); \
268 (cp)[2] = (unsigned char)((value) >> 8); \
269 (cp)[3] = (unsigned char)(value); }
271 /* Enumeration values for fields in SSH-1 packets */
273 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
274 /* These values are for communicating relevant semantics of
275 * fields to the packet logging code. */
276 PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA
280 * Coroutine mechanics for the sillier bits of the code. If these
281 * macros look impenetrable to you, you might find it helpful to
284 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
286 * which explains the theory behind these macros.
288 * In particular, if you are getting `case expression not constant'
289 * errors when building with MS Visual Studio, this is because MS's
290 * Edit and Continue debugging feature causes their compiler to
291 * violate ANSI C. To disable Edit and Continue debugging:
293 * - right-click ssh.c in the FileView
295 * - select the C/C++ tab and the General category
296 * - under `Debug info:', select anything _other_ than `Program
297 * Database for Edit and Continue'.
299 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
302 if (!ssh->t) ssh->t = snew(struct t); \
304 #define crFinish(z) } *crLine = 0; return (z); }
305 #define crFinishV } *crLine = 0; return; }
306 #define crReturn(z) \
308 *crLine =__LINE__; return (z); case __LINE__:;\
312 *crLine=__LINE__; return; case __LINE__:;\
314 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
315 #define crStopV do{ *crLine = 0; return; }while(0)
316 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
317 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
319 typedef struct ssh_tag *Ssh;
322 static struct Packet *ssh2_pkt_init(int pkt_type);
323 static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
324 static void ssh2_pkt_adduint32(struct Packet *, unsigned long value);
325 static void ssh2_pkt_addstring_start(struct Packet *);
326 static void ssh2_pkt_addstring_str(struct Packet *, char *data);
327 static void ssh2_pkt_addstring_data(struct Packet *, char *data, int len);
328 static void ssh2_pkt_addstring(struct Packet *, char *data);
329 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
330 static void ssh2_pkt_addmp(struct Packet *, Bignum b);
331 static int ssh2_pkt_construct(Ssh, struct Packet *);
332 static void ssh2_pkt_send(Ssh, struct Packet *);
333 static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
334 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
335 struct Packet *pktin);
336 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
337 struct Packet *pktin);
340 * Buffer management constants. There are several of these for
341 * various different purposes:
343 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
344 * on a local data stream before we throttle the whole SSH
345 * connection (in SSH1 only). Throttling the whole connection is
346 * pretty drastic so we set this high in the hope it won't
349 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
350 * on the SSH connection itself before we defensively throttle
351 * _all_ local data streams. This is pretty drastic too (though
352 * thankfully unlikely in SSH2 since the window mechanism should
353 * ensure that the server never has any need to throttle its end
354 * of the connection), so we set this high as well.
356 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
360 #define SSH1_BUFFER_LIMIT 32768
361 #define SSH_MAX_BACKLOG 32768
362 #define OUR_V2_WINSIZE 16384
363 #define OUR_V2_MAXPKT 0x4000UL
365 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
367 static void *nullmac_make_context(void)
371 static void nullmac_free_context(void *handle)
374 static void nullmac_key(void *handle, unsigned char *key)
377 static void nullmac_generate(void *handle, unsigned char *blk, int len,
381 static int nullmac_verify(void *handle, unsigned char *blk, int len,
386 const static struct ssh_mac ssh_mac_none = {
387 nullmac_make_context, nullmac_free_context, nullmac_key,
388 nullmac_generate, nullmac_verify, "none", 0
390 const static struct ssh_mac *macs[] = {
391 &ssh_sha1, &ssh_md5, &ssh_mac_none
393 const static struct ssh_mac *buggymacs[] = {
394 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
397 static void *ssh_comp_none_init(void)
401 static void ssh_comp_none_cleanup(void *handle)
404 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
405 unsigned char **outblock, int *outlen)
409 static int ssh_comp_none_disable(void *handle)
413 const static struct ssh_compress ssh_comp_none = {
415 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
416 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
417 ssh_comp_none_disable, NULL
419 extern const struct ssh_compress ssh_zlib;
420 const static struct ssh_compress *compressions[] = {
421 &ssh_zlib, &ssh_comp_none
424 enum { /* channel types */
429 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
433 * 2-3-4 tree storing channels.
436 Ssh ssh; /* pointer back to main context */
437 unsigned remoteid, localid;
440 * In SSH1, this value contains four bits:
442 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
443 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
444 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
445 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
447 * A channel is completely finished with when all four bits are set.
451 struct ssh1_data_channel {
454 struct ssh2_data_channel {
456 unsigned remwindow, remmaxpkt;
461 struct ssh_agent_channel {
462 unsigned char *message;
463 unsigned char msglen[4];
464 unsigned lensofar, totallen;
466 struct ssh_x11_channel {
469 struct ssh_pfd_channel {
476 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
477 * 2 use this structure in different ways, reflecting SSH 2's
478 * altogether saner approach to port forwarding.
480 * In SSH 1, you arrange a remote forwarding by sending the server
481 * the remote port number, and the local destination host:port.
482 * When a connection comes in, the server sends you back that
483 * host:port pair, and you connect to it. This is a ready-made
484 * security hole if you're not on the ball: a malicious server
485 * could send you back _any_ host:port pair, so if you trustingly
486 * connect to the address it gives you then you've just opened the
487 * entire inside of your corporate network just by connecting
488 * through it to a dodgy SSH server. Hence, we must store a list of
489 * host:port pairs we _are_ trying to forward to, and reject a
490 * connection request from the server if it's not in the list.
492 * In SSH 2, each side of the connection minds its own business and
493 * doesn't send unnecessary information to the other. You arrange a
494 * remote forwarding by sending the server just the remote port
495 * number. When a connection comes in, the server tells you which
496 * of its ports was connected to; and _you_ have to remember what
497 * local host:port pair went with that port number.
499 * Hence, in SSH 1 this structure is indexed by destination
500 * host:port pair, whereas in SSH 2 it is indexed by source port.
502 struct ssh_portfwd; /* forward declaration */
504 struct ssh_rportfwd {
505 unsigned sport, dport;
508 struct ssh_portfwd *pfrec;
510 #define free_rportfwd(pf) ( \
511 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
514 * Separately to the rportfwd tree (which is for looking up port
515 * open requests from the server), a tree of _these_ structures is
516 * used to keep track of all the currently open port forwardings,
517 * so that we can reconfigure in mid-session if the user requests
521 enum { DESTROY, KEEP, CREATE } status;
523 unsigned sport, dport;
526 struct ssh_rportfwd *remote;
530 #define free_portfwd(pf) ( \
531 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
532 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
536 long forcepad; /* Force padding to at least this length */
538 unsigned long sequence;
543 long encrypted_len; /* for SSH2 total-size counting */
546 * State associated with packet logging
550 struct logblank_t *blanks;
553 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
554 struct Packet *pktin);
555 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
556 struct Packet *pktin);
557 static void ssh1_protocol_setup(Ssh ssh);
558 static void ssh2_protocol_setup(Ssh ssh);
559 static void ssh_size(void *handle, int width, int height);
560 static void ssh_special(void *handle, Telnet_Special);
561 static int ssh2_try_send(struct ssh_channel *c);
562 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
563 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
564 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
565 static int ssh_sendbuffer(void *handle);
566 static int ssh_do_close(Ssh ssh, int notify_exit);
567 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
568 static int ssh2_pkt_getbool(struct Packet *pkt);
569 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
570 static void ssh2_timer(void *ctx, long now);
571 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
572 struct Packet *pktin);
574 struct rdpkt1_state_tag {
575 long len, pad, biglen, to_read;
576 unsigned long realcrc, gotcrc;
580 struct Packet *pktin;
583 struct rdpkt2_state_tag {
584 long len, pad, payload, packetlen, maclen;
587 unsigned long incoming_sequence;
588 struct Packet *pktin;
591 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
592 typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
594 struct queued_handler;
595 struct queued_handler {
597 chandler_fn_t handler;
599 struct queued_handler *next;
603 const struct plug_function_table *fn;
604 /* the above field _must_ be first in the structure */
606 SHA_State exhash, exhashbase;
613 unsigned char session_key[32];
615 int v1_remote_protoflags;
616 int v1_local_protoflags;
617 int agentfwd_enabled;
620 const struct ssh_cipher *cipher;
623 const struct ssh2_cipher *cscipher, *sccipher;
624 void *cs_cipher_ctx, *sc_cipher_ctx;
625 const struct ssh_mac *csmac, *scmac;
626 void *cs_mac_ctx, *sc_mac_ctx;
627 const struct ssh_compress *cscomp, *sccomp;
628 void *cs_comp_ctx, *sc_comp_ctx;
629 const struct ssh_kex *kex;
630 const struct ssh_signkey *hostkey;
631 unsigned char v2_session_id[20];
637 int echoing, editing;
641 int ospeed, ispeed; /* temporaries */
642 int term_width, term_height;
644 tree234 *channels; /* indexed by local id */
645 struct ssh_channel *mainchan; /* primary session channel */
649 tree234 *rportfwds, *portfwds;
653 SSH_STATE_BEFORE_SIZE,
659 int size_needed, eof_needed;
661 struct Packet **queue;
662 int queuelen, queuesize;
664 unsigned char *deferred_send_data;
665 int deferred_len, deferred_size;
668 * Gross hack: pscp will try to start SFTP but fall back to
669 * scp1 if that fails. This variable is the means by which
670 * scp.c can reach into the SSH code and find out which one it
676 * Used for username and password input.
678 char *userpass_input_buffer;
679 int userpass_input_buflen;
680 int userpass_input_bufpos;
681 int userpass_input_echo;
688 int v1_throttle_count;
691 int v1_stdout_throttling;
692 int v2_outgoing_sequence;
694 int ssh1_rdpkt_crstate;
695 int ssh2_rdpkt_crstate;
696 int do_ssh_init_crstate;
697 int ssh_gotdata_crstate;
698 int do_ssh1_login_crstate;
699 int do_ssh1_connection_crstate;
700 int do_ssh2_transport_crstate;
701 int do_ssh2_authconn_crstate;
703 void *do_ssh_init_state;
704 void *do_ssh1_login_state;
705 void *do_ssh2_transport_state;
706 void *do_ssh2_authconn_state;
708 struct rdpkt1_state_tag rdpkt1_state;
709 struct rdpkt2_state_tag rdpkt2_state;
711 /* ssh1 and ssh2 use this for different things, but both use it */
712 int protocol_initial_phase_done;
714 void (*protocol) (Ssh ssh, void *vin, int inlen,
716 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
719 * We maintain a full _copy_ of a Config structure here, not
720 * merely a pointer to it. That way, when we're passed a new
721 * one for reconfiguration, we can check the differences and
722 * potentially reconfigure port forwardings etc in mid-session.
727 * Used to transfer data back from async agent callbacks.
729 void *agent_response;
730 int agent_response_len;
733 * Dispatch table for packet types that we may have to deal
736 handler_fn_t packet_dispatch[256];
739 * Queues of one-off handler functions for success/failure
740 * indications from a request.
742 struct queued_handler *qhead, *qtail;
745 * This module deals with sending keepalives.
750 * Track incoming and outgoing data sizes and time, for
753 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
754 unsigned long max_data_size;
756 long next_rekey, last_rekey;
757 char *deferred_rekey_reason; /* points to STATIC string; don't free */
760 #define logevent(s) logevent(ssh->frontend, s)
762 /* logevent, only printf-formatted. */
763 static void logeventf(Ssh ssh, const char *fmt, ...)
769 buf = dupvprintf(fmt, ap);
775 #define bombout(msg) \
777 char *text = dupprintf msg; \
778 ssh_do_close(ssh, FALSE); \
780 connection_fatal(ssh->frontend, "%s", text); \
784 /* Functions to leave bits out of the SSH packet log file. */
786 static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
788 if (ssh->cfg.logomitpass)
789 pkt->logmode = blanktype;
792 static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
794 if (ssh->cfg.logomitdata)
795 pkt->logmode = blanktype;
798 static void end_log_omission(Ssh ssh, struct Packet *pkt)
800 pkt->logmode = PKTLOG_EMIT;
803 static int ssh_channelcmp(void *av, void *bv)
805 struct ssh_channel *a = (struct ssh_channel *) av;
806 struct ssh_channel *b = (struct ssh_channel *) bv;
807 if (a->localid < b->localid)
809 if (a->localid > b->localid)
813 static int ssh_channelfind(void *av, void *bv)
815 unsigned *a = (unsigned *) av;
816 struct ssh_channel *b = (struct ssh_channel *) bv;
824 static int ssh_rportcmp_ssh1(void *av, void *bv)
826 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
827 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
829 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
830 return i < 0 ? -1 : +1;
831 if (a->dport > b->dport)
833 if (a->dport < b->dport)
838 static int ssh_rportcmp_ssh2(void *av, void *bv)
840 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
841 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
843 if (a->sport > b->sport)
845 if (a->sport < b->sport)
851 * Special form of strcmp which can cope with NULL inputs. NULL is
852 * defined to sort before even the empty string.
854 static int nullstrcmp(const char *a, const char *b)
856 if (a == NULL && b == NULL)
865 static int ssh_portcmp(void *av, void *bv)
867 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
868 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
870 if (a->type > b->type)
872 if (a->type < b->type)
874 if (a->addressfamily > b->addressfamily)
876 if (a->addressfamily < b->addressfamily)
878 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
879 return i < 0 ? -1 : +1;
880 if (a->sport > b->sport)
882 if (a->sport < b->sport)
884 if (a->type != 'D') {
885 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
886 return i < 0 ? -1 : +1;
887 if (a->dport > b->dport)
889 if (a->dport < b->dport)
895 static int alloc_channel_id(Ssh ssh)
897 const unsigned CHANNEL_NUMBER_OFFSET = 256;
898 unsigned low, high, mid;
900 struct ssh_channel *c;
903 * First-fit allocation of channel numbers: always pick the
904 * lowest unused one. To do this, binary-search using the
905 * counted B-tree to find the largest channel ID which is in a
906 * contiguous sequence from the beginning. (Precisely
907 * everything in that sequence must have ID equal to its tree
908 * index plus CHANNEL_NUMBER_OFFSET.)
910 tsize = count234(ssh->channels);
914 while (high - low > 1) {
915 mid = (high + low) / 2;
916 c = index234(ssh->channels, mid);
917 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
918 low = mid; /* this one is fine */
920 high = mid; /* this one is past it */
923 * Now low points to either -1, or the tree index of the
924 * largest ID in the initial sequence.
927 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
928 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
930 return low + 1 + CHANNEL_NUMBER_OFFSET;
933 static void c_write(Ssh ssh, const char *buf, int len)
935 if ((flags & FLAG_STDERR)) {
937 for (i = 0; i < len; i++)
939 fputc(buf[i], stderr);
942 from_backend(ssh->frontend, 1, buf, len);
945 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
948 for (i = 0; i < len; i++) {
950 c_write(ssh, "\r\n", 2);
951 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
952 c_write(ssh, buf + i, 1);
956 static void c_write_str(Ssh ssh, const char *buf)
958 c_write(ssh, buf, strlen(buf));
961 static void ssh_free_packet(struct Packet *pkt)
966 static struct Packet *ssh_new_packet(void)
968 struct Packet *pkt = snew(struct Packet);
972 pkt->logmode = PKTLOG_EMIT;
980 * Collect incoming data in the incoming packet buffer.
981 * Decipher and verify the packet when it is completely read.
982 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
983 * Update the *data and *datalen variables.
984 * Return a Packet structure when a packet is completed.
986 static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
988 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
990 crBegin(ssh->ssh1_rdpkt_crstate);
992 st->pktin = ssh_new_packet();
995 st->pktin->length = 0;
997 for (st->i = st->len = 0; st->i < 4; st->i++) {
998 while ((*datalen) == 0)
1000 st->len = (st->len << 8) + **data;
1001 (*data)++, (*datalen)--;
1004 st->pad = 8 - (st->len % 8);
1005 st->biglen = st->len + st->pad;
1006 st->pktin->length = st->len - 5;
1008 if (st->biglen < 0) {
1009 bombout(("Extremely large packet length from server suggests"
1010 " data stream corruption"));
1011 ssh_free_packet(st->pktin);
1015 st->pktin->maxlen = st->biglen;
1016 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1018 st->to_read = st->biglen;
1019 st->p = st->pktin->data;
1020 while (st->to_read > 0) {
1021 st->chunk = st->to_read;
1022 while ((*datalen) == 0)
1024 if (st->chunk > (*datalen))
1025 st->chunk = (*datalen);
1026 memcpy(st->p, *data, st->chunk);
1028 *datalen -= st->chunk;
1030 st->to_read -= st->chunk;
1033 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1034 st->biglen, NULL)) {
1035 bombout(("Network attack (CRC compensation) detected!"));
1036 ssh_free_packet(st->pktin);
1041 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1043 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1044 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1045 if (st->gotcrc != st->realcrc) {
1046 bombout(("Incorrect CRC received on packet"));
1047 ssh_free_packet(st->pktin);
1051 st->pktin->body = st->pktin->data + st->pad + 1;
1052 st->pktin->savedpos = 0;
1054 if (ssh->v1_compressing) {
1055 unsigned char *decompblk;
1057 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1058 st->pktin->body - 1, st->pktin->length + 1,
1059 &decompblk, &decomplen)) {
1060 bombout(("Zlib decompression encountered invalid data"));
1061 ssh_free_packet(st->pktin);
1065 if (st->pktin->maxlen < st->pad + decomplen) {
1066 st->pktin->maxlen = st->pad + decomplen;
1067 st->pktin->data = sresize(st->pktin->data,
1068 st->pktin->maxlen + APIEXTRA,
1070 st->pktin->body = st->pktin->data + st->pad + 1;
1073 memcpy(st->pktin->body - 1, decompblk, decomplen);
1075 st->pktin->length = decomplen - 1;
1078 st->pktin->type = st->pktin->body[-1];
1081 * Log incoming packet, possibly omitting sensitive fields.
1085 struct logblank_t blank;
1086 if (ssh->cfg.logomitdata) {
1087 int do_blank = FALSE, blank_prefix = 0;
1088 /* "Session data" packets - omit the data field */
1089 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1090 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
1091 do_blank = TRUE; blank_prefix = 0;
1092 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
1093 do_blank = TRUE; blank_prefix = 4;
1096 blank.offset = blank_prefix;
1097 blank.len = st->pktin->length;
1098 blank.type = PKTLOG_OMIT;
1102 log_packet(ssh->logctx,
1103 PKT_INCOMING, st->pktin->type,
1104 ssh1_pkt_type(st->pktin->type),
1105 st->pktin->body, st->pktin->length,
1109 crFinish(st->pktin);
1112 static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1114 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1116 crBegin(ssh->ssh2_rdpkt_crstate);
1118 st->pktin = ssh_new_packet();
1120 st->pktin->type = 0;
1121 st->pktin->length = 0;
1123 st->cipherblk = ssh->sccipher->blksize;
1126 if (st->cipherblk < 8)
1129 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1132 * Acquire and decrypt the first block of the packet. This will
1133 * contain the length and padding details.
1135 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1136 while ((*datalen) == 0)
1138 st->pktin->data[st->i] = *(*data)++;
1143 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1144 st->pktin->data, st->cipherblk);
1147 * Now get the length and padding figures.
1149 st->len = GET_32BIT(st->pktin->data);
1150 st->pad = st->pktin->data[4];
1153 * _Completely_ silly lengths should be stomped on before they
1154 * do us any more damage.
1156 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
1157 bombout(("Incoming packet was garbled on decryption"));
1158 ssh_free_packet(st->pktin);
1163 * This enables us to deduce the payload length.
1165 st->payload = st->len - st->pad - 1;
1167 st->pktin->length = st->payload + 5;
1170 * So now we can work out the total packet length.
1172 st->packetlen = st->len + 4;
1173 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1176 * Allocate memory for the rest of the packet.
1178 st->pktin->maxlen = st->packetlen + st->maclen;
1179 st->pktin->data = sresize(st->pktin->data,
1180 st->pktin->maxlen + APIEXTRA,
1184 * Read and decrypt the remainder of the packet.
1186 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1188 while ((*datalen) == 0)
1190 st->pktin->data[st->i] = *(*data)++;
1193 /* Decrypt everything _except_ the MAC. */
1195 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1196 st->pktin->data + st->cipherblk,
1197 st->packetlen - st->cipherblk);
1199 st->pktin->encrypted_len = st->packetlen;
1205 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, st->len + 4,
1206 st->incoming_sequence)) {
1207 bombout(("Incorrect MAC received on packet"));
1208 ssh_free_packet(st->pktin);
1212 st->pktin->sequence = st->incoming_sequence++;
1215 * Decompress packet payload.
1218 unsigned char *newpayload;
1221 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1222 st->pktin->data + 5, st->pktin->length - 5,
1223 &newpayload, &newlen)) {
1224 if (st->pktin->maxlen < newlen + 5) {
1225 st->pktin->maxlen = newlen + 5;
1226 st->pktin->data = sresize(st->pktin->data,
1227 st->pktin->maxlen + APIEXTRA,
1230 st->pktin->length = 5 + newlen;
1231 memcpy(st->pktin->data + 5, newpayload, newlen);
1236 st->pktin->savedpos = 6;
1237 st->pktin->body = st->pktin->data;
1238 st->pktin->type = st->pktin->data[5];
1241 * Log incoming packet, possibly omitting sensitive fields.
1245 struct logblank_t blank;
1246 if (ssh->cfg.logomitdata) {
1247 int do_blank = FALSE, blank_prefix = 0;
1248 /* "Session data" packets - omit the data field */
1249 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
1250 do_blank = TRUE; blank_prefix = 4;
1251 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1252 do_blank = TRUE; blank_prefix = 8;
1255 blank.offset = blank_prefix;
1256 blank.len = (st->pktin->length-6) - blank_prefix;
1257 blank.type = PKTLOG_OMIT;
1261 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1262 ssh2_pkt_type(ssh->pkt_ctx, st->pktin->type),
1263 st->pktin->data+6, st->pktin->length-6,
1267 crFinish(st->pktin);
1270 static void ssh1_pktout_size(struct Packet *pkt, int len)
1274 len += 5; /* type and CRC */
1275 pad = 8 - (len % 8);
1278 pkt->length = len - 5;
1279 if (pkt->maxlen < biglen) {
1280 pkt->maxlen = biglen;
1281 pkt->data = sresize(pkt->data, biglen + 4 + APIEXTRA, unsigned char);
1283 pkt->body = pkt->data + 4 + pad + 1;
1286 static struct Packet *s_wrpkt_start(int type, int len)
1288 struct Packet *pkt = ssh_new_packet();
1289 ssh1_pktout_size(pkt, len);
1291 /* Initialise log omission state */
1297 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt)
1303 * XXX various versions of SC (including 8.8.4) screw up the
1304 * register allocation in this function and use the same register
1305 * (D6) for len and as a temporary, with predictable results. The
1306 * following sledgehammer prevents this.
1312 pkt->body[-1] = pkt->type;
1315 log_packet(ssh->logctx, PKT_OUTGOING, pkt->type,
1316 ssh1_pkt_type(pkt->type),
1317 pkt->body, pkt->length,
1318 pkt->nblanks, pkt->blanks);
1319 sfree(pkt->blanks); pkt->blanks = NULL;
1322 if (ssh->v1_compressing) {
1323 unsigned char *compblk;
1325 zlib_compress_block(ssh->cs_comp_ctx,
1326 pkt->body - 1, pkt->length + 1,
1327 &compblk, &complen);
1328 ssh1_pktout_size(pkt, complen - 1);
1329 memcpy(pkt->body - 1, compblk, complen);
1333 len = pkt->length + 5; /* type and CRC */
1334 pad = 8 - (len % 8);
1337 for (i = 0; i < pad; i++)
1338 pkt->data[i + 4] = random_byte();
1339 crc = crc32_compute(pkt->data + 4, biglen - 4);
1340 PUT_32BIT(pkt->data + biglen, crc);
1341 PUT_32BIT(pkt->data, len);
1344 ssh->cipher->encrypt(ssh->v1_cipher_ctx, pkt->data + 4, biglen);
1349 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1352 len = s_wrpkt_prepare(ssh, pkt);
1353 backlog = sk_write(ssh->s, (char *)pkt->data, len);
1354 if (backlog > SSH_MAX_BACKLOG)
1355 ssh_throttle_all(ssh, 1, backlog);
1358 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1361 len = s_wrpkt_prepare(ssh, pkt);
1362 if (ssh->deferred_len + len > ssh->deferred_size) {
1363 ssh->deferred_size = ssh->deferred_len + len + 128;
1364 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1368 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
1369 ssh->deferred_len += len;
1373 * Construct a packet with the specified contents.
1375 static struct Packet *construct_packet(Ssh ssh, int pkttype,
1376 va_list ap1, va_list ap2)
1378 unsigned char *p, *argp, argchar;
1379 unsigned long argint;
1380 int pktlen, argtype, arglen;
1385 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1388 (void) va_arg(ap1, int);
1392 (void) va_arg(ap1, int);
1396 (void) va_arg(ap1, unsigned char *);
1397 arglen = va_arg(ap1, int);
1401 argp = va_arg(ap1, unsigned char *);
1402 arglen = strlen((char *)argp);
1403 pktlen += 4 + arglen;
1406 bn = va_arg(ap1, Bignum);
1407 pktlen += ssh1_bignum_length(bn);
1412 /* ignore this pass */
1419 pkt = s_wrpkt_start(pkttype, pktlen);
1422 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1423 int offset = p - pkt->body, len = 0;
1425 /* Actual fields in the packet */
1427 argint = va_arg(ap2, int);
1428 PUT_32BIT(p, argint);
1432 argchar = (unsigned char) va_arg(ap2, int);
1437 argp = va_arg(ap2, unsigned char *);
1438 arglen = va_arg(ap2, int);
1439 memcpy(p, argp, arglen);
1443 argp = va_arg(ap2, unsigned char *);
1444 arglen = strlen((char *)argp);
1445 PUT_32BIT(p, arglen);
1446 memcpy(p + 4, argp, arglen);
1450 bn = va_arg(ap2, Bignum);
1451 len = ssh1_write_bignum(p, bn);
1453 /* Tokens for modifications to packet logging */
1455 dont_log_password(ssh, pkt, PKTLOG_BLANK);
1458 dont_log_data(ssh, pkt, PKTLOG_OMIT);
1461 end_log_omission(ssh, pkt);
1465 /* Deal with logfile omission, if required. */
1466 if (len && (pkt->logmode != PKTLOG_EMIT)) {
1468 pkt->blanks = sresize(pkt->blanks, pkt->nblanks,
1470 pkt->blanks[pkt->nblanks-1].offset = offset;
1471 pkt->blanks[pkt->nblanks-1].len = len;
1472 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1479 static void send_packet(Ssh ssh, int pkttype, ...)
1483 va_start(ap1, pkttype);
1484 va_start(ap2, pkttype);
1485 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1489 ssh_free_packet(pkt);
1492 static void defer_packet(Ssh ssh, int pkttype, ...)
1496 va_start(ap1, pkttype);
1497 va_start(ap2, pkttype);
1498 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1501 s_wrpkt_defer(ssh, pkt);
1502 ssh_free_packet(pkt);
1505 static int ssh_versioncmp(char *a, char *b)
1508 unsigned long av, bv;
1510 av = strtoul(a, &ae, 10);
1511 bv = strtoul(b, &be, 10);
1513 return (av < bv ? -1 : +1);
1518 av = strtoul(ae, &ae, 10);
1519 bv = strtoul(be, &be, 10);
1521 return (av < bv ? -1 : +1);
1526 * Utility routines for putting an SSH-protocol `string' and
1527 * `uint32' into a SHA state.
1530 static void sha_string(SHA_State * s, void *str, int len)
1532 unsigned char lenblk[4];
1533 PUT_32BIT(lenblk, len);
1534 SHA_Bytes(s, lenblk, 4);
1535 SHA_Bytes(s, str, len);
1538 static void sha_uint32(SHA_State * s, unsigned i)
1540 unsigned char intblk[4];
1541 PUT_32BIT(intblk, i);
1542 SHA_Bytes(s, intblk, 4);
1546 * SSH2 packet construction functions.
1548 static void ssh2_pkt_ensure(struct Packet *pkt, int length)
1550 if (pkt->maxlen < length) {
1551 pkt->maxlen = length + 256;
1552 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
1555 static void ssh2_pkt_adddata(struct Packet *pkt, void *data, int len)
1557 if (pkt->logmode != PKTLOG_EMIT) {
1559 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1560 pkt->blanks[pkt->nblanks-1].offset = pkt->length - 6;
1561 pkt->blanks[pkt->nblanks-1].len = len;
1562 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1565 ssh2_pkt_ensure(pkt, pkt->length);
1566 memcpy(pkt->data + pkt->length - len, data, len);
1568 static void ssh2_pkt_addbyte(struct Packet *pkt, unsigned char byte)
1570 ssh2_pkt_adddata(pkt, &byte, 1);
1572 static struct Packet *ssh2_pkt_init(int pkt_type)
1574 struct Packet *pkt = ssh_new_packet();
1577 ssh2_pkt_addbyte(pkt, (unsigned char) pkt_type);
1580 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
1582 ssh2_pkt_adddata(pkt, &value, 1);
1584 static void ssh2_pkt_adduint32(struct Packet *pkt, unsigned long value)
1587 PUT_32BIT(x, value);
1588 ssh2_pkt_adddata(pkt, x, 4);
1590 static void ssh2_pkt_addstring_start(struct Packet *pkt)
1592 ssh2_pkt_adduint32(pkt, 0);
1593 pkt->savedpos = pkt->length;
1595 static void ssh2_pkt_addstring_str(struct Packet *pkt, char *data)
1597 ssh2_pkt_adddata(pkt, data, strlen(data));
1598 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1600 static void ssh2_pkt_addstring_data(struct Packet *pkt, char *data, int len)
1602 ssh2_pkt_adddata(pkt, data, len);
1603 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1605 static void ssh2_pkt_addstring(struct Packet *pkt, char *data)
1607 ssh2_pkt_addstring_start(pkt);
1608 ssh2_pkt_addstring_str(pkt, data);
1610 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1613 int i, n = (bignum_bitcount(b) + 7) / 8;
1614 p = snewn(n + 1, unsigned char);
1616 fatalbox("out of memory");
1618 for (i = 1; i <= n; i++)
1619 p[i] = bignum_byte(b, n - i);
1621 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1623 memmove(p, p + i, n + 1 - i);
1627 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
1631 p = ssh2_mpint_fmt(b, &len);
1632 ssh2_pkt_addstring_start(pkt);
1633 ssh2_pkt_addstring_data(pkt, (char *)p, len);
1638 * Construct an SSH2 final-form packet: compress it, encrypt it,
1639 * put the MAC on it. Final packet, ready to be sent, is stored in
1640 * pkt->data. Total length is returned.
1642 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
1644 int cipherblk, maclen, padding, i;
1647 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1648 ssh2_pkt_type(ssh->pkt_ctx, pkt->data[5]),
1649 pkt->data + 6, pkt->length - 6,
1650 pkt->nblanks, pkt->blanks);
1651 sfree(pkt->blanks); pkt->blanks = NULL;
1655 * Compress packet payload.
1658 unsigned char *newpayload;
1661 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1663 &newpayload, &newlen)) {
1665 ssh2_pkt_adddata(pkt, newpayload, newlen);
1671 * Add padding. At least four bytes, and must also bring total
1672 * length (minus MAC) up to a multiple of the block size.
1673 * If pkt->forcepad is set, make sure the packet is at least that size
1676 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1677 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1679 if (pkt->length + padding < pkt->forcepad)
1680 padding = pkt->forcepad - pkt->length;
1682 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
1683 assert(padding <= 255);
1684 maclen = ssh->csmac ? ssh->csmac->len : 0;
1685 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1686 pkt->data[4] = padding;
1687 for (i = 0; i < padding; i++)
1688 pkt->data[pkt->length + i] = random_byte();
1689 PUT_32BIT(pkt->data, pkt->length + padding - 4);
1691 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1692 pkt->length + padding,
1693 ssh->v2_outgoing_sequence);
1694 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1697 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1698 pkt->data, pkt->length + padding);
1700 pkt->encrypted_len = pkt->length + padding;
1702 /* Ready-to-send packet starts at pkt->data. We return length. */
1703 return pkt->length + padding + maclen;
1707 * Routines called from the main SSH code to send packets. There
1708 * are quite a few of these, because we have two separate
1709 * mechanisms for delaying the sending of packets:
1711 * - In order to send an IGNORE message and a password message in
1712 * a single fixed-length blob, we require the ability to
1713 * concatenate the encrypted forms of those two packets _into_ a
1714 * single blob and then pass it to our <network.h> transport
1715 * layer in one go. Hence, there's a deferment mechanism which
1716 * works after packet encryption.
1718 * - In order to avoid sending any connection-layer messages
1719 * during repeat key exchange, we have to queue up any such
1720 * outgoing messages _before_ they are encrypted (and in
1721 * particular before they're allocated sequence numbers), and
1722 * then send them once we've finished.
1724 * I call these mechanisms `defer' and `queue' respectively, so as
1725 * to distinguish them reasonably easily.
1727 * The functions send_noqueue() and defer_noqueue() free the packet
1728 * structure they are passed. Every outgoing packet goes through
1729 * precisely one of these functions in its life; packets passed to
1730 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
1731 * these or get queued, and then when the queue is later emptied
1732 * the packets are all passed to defer_noqueue().
1736 * Send an SSH2 packet immediately, without queuing or deferring.
1738 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
1742 len = ssh2_pkt_construct(ssh, pkt);
1743 backlog = sk_write(ssh->s, (char *)pkt->data, len);
1744 if (backlog > SSH_MAX_BACKLOG)
1745 ssh_throttle_all(ssh, 1, backlog);
1747 ssh->outgoing_data_size += pkt->encrypted_len;
1748 if (!ssh->kex_in_progress &&
1749 ssh->max_data_size != 0 &&
1750 ssh->outgoing_data_size > ssh->max_data_size)
1751 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
1753 ssh_free_packet(pkt);
1757 * Defer an SSH2 packet.
1759 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt)
1761 int len = ssh2_pkt_construct(ssh, pkt);
1762 if (ssh->deferred_len + len > ssh->deferred_size) {
1763 ssh->deferred_size = ssh->deferred_len + len + 128;
1764 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1768 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
1769 ssh->deferred_len += len;
1770 ssh->deferred_data_size += pkt->encrypted_len;
1771 ssh_free_packet(pkt);
1775 * Queue an SSH2 packet.
1777 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
1779 assert(ssh->queueing);
1781 if (ssh->queuelen >= ssh->queuesize) {
1782 ssh->queuesize = ssh->queuelen + 32;
1783 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
1786 ssh->queue[ssh->queuelen++] = pkt;
1790 * Either queue or send a packet, depending on whether queueing is
1793 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
1796 ssh2_pkt_queue(ssh, pkt);
1798 ssh2_pkt_send_noqueue(ssh, pkt);
1803 * Either queue or defer a packet, depending on whether queueing is
1806 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
1809 ssh2_pkt_queue(ssh, pkt);
1811 ssh2_pkt_defer_noqueue(ssh, pkt);
1816 * Send the whole deferred data block constructed by
1817 * ssh2_pkt_defer() or SSH1's defer_packet().
1819 * The expected use of the defer mechanism is that you call
1820 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
1821 * not currently queueing, this simply sets up deferred_send_data
1822 * and then sends it. If we _are_ currently queueing, the calls to
1823 * ssh2_pkt_defer() put the deferred packets on to the queue
1824 * instead, and therefore ssh_pkt_defersend() has no deferred data
1825 * to send. Hence, there's no need to make it conditional on
1828 static void ssh_pkt_defersend(Ssh ssh)
1831 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1833 ssh->deferred_len = ssh->deferred_size = 0;
1834 sfree(ssh->deferred_send_data);
1835 ssh->deferred_send_data = NULL;
1836 if (backlog > SSH_MAX_BACKLOG)
1837 ssh_throttle_all(ssh, 1, backlog);
1839 ssh->outgoing_data_size += ssh->deferred_data_size;
1840 if (!ssh->kex_in_progress &&
1841 ssh->max_data_size != 0 &&
1842 ssh->outgoing_data_size > ssh->max_data_size)
1843 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
1844 ssh->deferred_data_size = 0;
1848 * Send all queued SSH2 packets. We send them by means of
1849 * ssh2_pkt_defer_noqueue(), in case they included a pair of
1850 * packets that needed to be lumped together.
1852 static void ssh2_pkt_queuesend(Ssh ssh)
1856 assert(!ssh->queueing);
1858 for (i = 0; i < ssh->queuelen; i++)
1859 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i]);
1862 ssh_pkt_defersend(ssh);
1866 void bndebug(char *string, Bignum b)
1870 p = ssh2_mpint_fmt(b, &len);
1871 debug(("%s", string));
1872 for (i = 0; i < len; i++)
1873 debug((" %02x", p[i]));
1879 static void sha_mpint(SHA_State * s, Bignum b)
1883 p = ssh2_mpint_fmt(b, &len);
1884 sha_string(s, p, len);
1889 * Packet decode functions for both SSH1 and SSH2.
1891 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
1893 unsigned long value;
1894 if (pkt->length - pkt->savedpos < 4)
1895 return 0; /* arrgh, no way to decline (FIXME?) */
1896 value = GET_32BIT(pkt->body + pkt->savedpos);
1900 static int ssh2_pkt_getbool(struct Packet *pkt)
1902 unsigned long value;
1903 if (pkt->length - pkt->savedpos < 1)
1904 return 0; /* arrgh, no way to decline (FIXME?) */
1905 value = pkt->body[pkt->savedpos] != 0;
1909 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
1914 if (pkt->length - pkt->savedpos < 4)
1916 len = GET_32BIT(pkt->body + pkt->savedpos);
1921 if (pkt->length - pkt->savedpos < *length)
1923 *p = (char *)(pkt->body + pkt->savedpos);
1924 pkt->savedpos += *length;
1926 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
1928 if (pkt->length - pkt->savedpos < length)
1930 pkt->savedpos += length;
1931 return pkt->body + (pkt->savedpos - length);
1933 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
1934 unsigned char **keystr)
1938 j = makekey(pkt->body + pkt->savedpos,
1939 pkt->length - pkt->savedpos,
1946 assert(pkt->savedpos < pkt->length);
1950 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
1955 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
1956 pkt->length - pkt->savedpos, &b);
1964 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
1970 ssh_pkt_getstring(pkt, &p, &length);
1975 b = bignum_from_bytes((unsigned char *)p, length);
1980 * Helper function to add an SSH2 signature blob to a packet.
1981 * Expects to be shown the public key blob as well as the signature
1982 * blob. Normally works just like ssh2_pkt_addstring, but will
1983 * fiddle with the signature packet if necessary for
1984 * BUG_SSH2_RSA_PADDING.
1986 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
1987 void *pkblob_v, int pkblob_len,
1988 void *sigblob_v, int sigblob_len)
1990 unsigned char *pkblob = (unsigned char *)pkblob_v;
1991 unsigned char *sigblob = (unsigned char *)sigblob_v;
1993 /* dmemdump(pkblob, pkblob_len); */
1994 /* dmemdump(sigblob, sigblob_len); */
1997 * See if this is in fact an ssh-rsa signature and a buggy
1998 * server; otherwise we can just do this the easy way.
2000 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
2001 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2002 int pos, len, siglen;
2005 * Find the byte length of the modulus.
2008 pos = 4+7; /* skip over "ssh-rsa" */
2009 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
2010 len = GET_32BIT(pkblob+pos); /* find length of modulus */
2011 pos += 4; /* find modulus itself */
2012 while (len > 0 && pkblob[pos] == 0)
2014 /* debug(("modulus length is %d\n", len)); */
2017 * Now find the signature integer.
2019 pos = 4+7; /* skip over "ssh-rsa" */
2020 siglen = GET_32BIT(sigblob+pos);
2021 /* debug(("signature length is %d\n", siglen)); */
2023 if (len != siglen) {
2024 unsigned char newlen[4];
2025 ssh2_pkt_addstring_start(pkt);
2026 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2027 /* dmemdump(sigblob, pos); */
2028 pos += 4; /* point to start of actual sig */
2029 PUT_32BIT(newlen, len);
2030 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2031 /* dmemdump(newlen, 4); */
2033 while (len-- > siglen) {
2034 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2035 /* dmemdump(newlen, 1); */
2037 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2038 /* dmemdump(sigblob+pos, siglen); */
2042 /* Otherwise fall through and do it the easy way. */
2045 ssh2_pkt_addstring_start(pkt);
2046 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2050 * Examine the remote side's version string and compare it against
2051 * a list of known buggy implementations.
2053 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2055 char *imp; /* pointer to implementation part */
2057 imp += strcspn(imp, "-");
2059 imp += strcspn(imp, "-");
2062 ssh->remote_bugs = 0;
2064 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
2065 (ssh->cfg.sshbug_ignore1 == AUTO &&
2066 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2067 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2068 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2069 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2071 * These versions don't support SSH1_MSG_IGNORE, so we have
2072 * to use a different defence against password length
2075 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2076 logevent("We believe remote version has SSH1 ignore bug");
2079 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
2080 (ssh->cfg.sshbug_plainpw1 == AUTO &&
2081 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2083 * These versions need a plain password sent; they can't
2084 * handle having a null and a random length of data after
2087 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2088 logevent("We believe remote version needs a plain SSH1 password");
2091 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
2092 (ssh->cfg.sshbug_rsa1 == AUTO &&
2093 (!strcmp(imp, "Cisco-1.25")))) {
2095 * These versions apparently have no clue whatever about
2096 * RSA authentication and will panic and die if they see
2097 * an AUTH_RSA message.
2099 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2100 logevent("We believe remote version can't handle RSA authentication");
2103 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2104 (ssh->cfg.sshbug_hmac2 == AUTO &&
2105 !wc_match("* VShell", imp) &&
2106 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2107 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2108 wc_match("2.1 *", imp)))) {
2110 * These versions have the HMAC bug.
2112 ssh->remote_bugs |= BUG_SSH2_HMAC;
2113 logevent("We believe remote version has SSH2 HMAC bug");
2116 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2117 (ssh->cfg.sshbug_derivekey2 == AUTO &&
2118 !wc_match("* VShell", imp) &&
2119 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2121 * These versions have the key-derivation bug (failing to
2122 * include the literal shared secret in the hashes that
2123 * generate the keys).
2125 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2126 logevent("We believe remote version has SSH2 key-derivation bug");
2129 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2130 (ssh->cfg.sshbug_rsapad2 == AUTO &&
2131 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2132 wc_match("OpenSSH_3.[0-2]*", imp)))) {
2134 * These versions have the SSH2 RSA padding bug.
2136 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2137 logevent("We believe remote version has SSH2 RSA padding bug");
2140 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2141 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2142 wc_match("OpenSSH_2.[0-2]*", imp))) {
2144 * These versions have the SSH2 session-ID bug in
2145 * public-key authentication.
2147 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2148 logevent("We believe remote version has SSH2 public-key-session-ID bug");
2151 if (ssh->cfg.sshbug_rekey2 == FORCE_ON ||
2152 (ssh->cfg.sshbug_rekey2 == AUTO &&
2153 (wc_match("OpenSSH_2.[0-4]*", imp) ||
2154 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2155 wc_match("Sun_SSH_1.0", imp) ||
2156 wc_match("Sun_SSH_1.0.1", imp)))) {
2158 * These versions have the SSH2 rekey bug.
2160 ssh->remote_bugs |= BUG_SSH2_REKEY;
2161 logevent("We believe remote version has SSH2 rekey bug");
2166 * The `software version' part of an SSH version string is required
2167 * to contain no spaces or minus signs.
2169 static void ssh_fix_verstring(char *str)
2171 /* Eat "SSH-<protoversion>-". */
2172 assert(*str == 'S'); str++;
2173 assert(*str == 'S'); str++;
2174 assert(*str == 'H'); str++;
2175 assert(*str == '-'); str++;
2176 while (*str && *str != '-') str++;
2177 assert(*str == '-'); str++;
2179 /* Convert minus signs and spaces in the remaining string into
2182 if (*str == '-' || *str == ' ')
2188 static int do_ssh_init(Ssh ssh, unsigned char c)
2190 struct do_ssh_init_state {
2198 crState(do_ssh_init_state);
2200 crBegin(ssh->do_ssh_init_crstate);
2202 /* Search for the string "SSH-" in the input. */
2205 static const int transS[] = { 1, 2, 2, 1 };
2206 static const int transH[] = { 0, 0, 3, 0 };
2207 static const int transminus[] = { 0, 0, 0, -1 };
2209 s->i = transS[s->i];
2211 s->i = transH[s->i];
2213 s->i = transminus[s->i];
2218 crReturn(1); /* get another character */
2222 s->vstring = snewn(s->vstrsize, char);
2223 strcpy(s->vstring, "SSH-");
2227 crReturn(1); /* get another char */
2228 if (s->vslen >= s->vstrsize - 1) {
2230 s->vstring = sresize(s->vstring, s->vstrsize, char);
2232 s->vstring[s->vslen++] = c;
2235 s->version[s->i] = '\0';
2237 } else if (s->i < sizeof(s->version) - 1)
2238 s->version[s->i++] = c;
2239 } else if (c == '\012')
2243 ssh->agentfwd_enabled = FALSE;
2244 ssh->rdpkt2_state.incoming_sequence = 0;
2246 s->vstring[s->vslen] = 0;
2247 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2250 vlog = snewn(20 + s->vslen, char);
2251 sprintf(vlog, "Server version: %s", s->vstring);
2255 ssh_detect_bugs(ssh, s->vstring);
2258 * Decide which SSH protocol version to support.
2261 /* Anything strictly below "2.0" means protocol 1 is supported. */
2262 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2263 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2264 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2266 if (ssh->cfg.sshprot == 0 && !s->proto1) {
2267 bombout(("SSH protocol version 1 required by user but not provided by server"));
2270 if (ssh->cfg.sshprot == 3 && !s->proto2) {
2271 bombout(("SSH protocol version 2 required by user but not provided by server"));
2278 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2280 * Construct a v2 version string.
2282 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2286 * Construct a v1 version string.
2288 verstring = dupprintf("SSH-%s-%s\012",
2289 (ssh_versioncmp(s->version, "1.5") <= 0 ?
2290 s->version : "1.5"),
2295 ssh_fix_verstring(verstring);
2297 if (ssh->version == 2) {
2299 * Hash our version string and their version string.
2301 SHA_Init(&ssh->exhashbase);
2302 sha_string(&ssh->exhashbase, verstring,
2303 strcspn(verstring, "\015\012"));
2304 sha_string(&ssh->exhashbase, s->vstring,
2305 strcspn(s->vstring, "\015\012"));
2308 * Initialise SSHv2 protocol.
2310 ssh->protocol = ssh2_protocol;
2311 ssh2_protocol_setup(ssh);
2312 ssh->s_rdpkt = ssh2_rdpkt;
2315 * Initialise SSHv1 protocol.
2317 ssh->protocol = ssh1_protocol;
2318 ssh1_protocol_setup(ssh);
2319 ssh->s_rdpkt = ssh1_rdpkt;
2321 logeventf(ssh, "We claim version: %.*s",
2322 strcspn(verstring, "\015\012"), verstring);
2323 sk_write(ssh->s, verstring, strlen(verstring));
2327 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2329 update_specials_menu(ssh->frontend);
2330 ssh->state = SSH_STATE_BEFORE_SIZE;
2331 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
2338 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2340 crBegin(ssh->ssh_gotdata_crstate);
2343 * To begin with, feed the characters one by one to the
2344 * protocol initialisation / selection function do_ssh_init().
2345 * When that returns 0, we're done with the initial greeting
2346 * exchange and can move on to packet discipline.
2349 int ret; /* need not be kept across crReturn */
2351 crReturnV; /* more data please */
2352 ret = do_ssh_init(ssh, *data);
2360 * We emerge from that loop when the initial negotiation is
2361 * over and we have selected an s_rdpkt function. Now pass
2362 * everything to s_rdpkt, and then pass the resulting packets
2363 * to the proper protocol handler.
2368 while (datalen > 0) {
2369 struct Packet *pktin = ssh->s_rdpkt(ssh, &data, &datalen);
2371 ssh->protocol(ssh, NULL, 0, pktin);
2372 ssh_free_packet(pktin);
2374 if (ssh->state == SSH_STATE_CLOSED)
2382 static int ssh_do_close(Ssh ssh, int notify_exit)
2385 struct ssh_channel *c;
2387 ssh->state = SSH_STATE_CLOSED;
2392 notify_remote_exit(ssh->frontend);
2397 * Now we must shut down any port and X forwardings going
2398 * through this connection.
2400 if (ssh->channels) {
2401 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2404 x11_close(c->u.x11.s);
2407 pfd_close(c->u.pfd.s);
2410 del234(ssh->channels, c);
2411 if (ssh->version == 2)
2412 bufchain_clear(&c->v.v2.outbuffer);
2420 static void ssh_log(Plug plug, int type, SockAddr addr, int port,
2421 const char *error_msg, int error_code)
2423 Ssh ssh = (Ssh) plug;
2424 char addrbuf[256], *msg;
2426 sk_getaddr(addr, addrbuf, lenof(addrbuf));
2429 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
2431 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
2436 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2439 Ssh ssh = (Ssh) plug;
2440 int need_notify = ssh_do_close(ssh, FALSE);
2442 if (!error_msg && !ssh->close_expected) {
2443 error_msg = "Server unexpectedly closed network connection";
2447 /* A socket error has occurred. */
2448 logevent(error_msg);
2449 connection_fatal(ssh->frontend, "%s", error_msg);
2451 logevent("Server closed network connection");
2454 notify_remote_exit(ssh->frontend);
2458 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2460 Ssh ssh = (Ssh) plug;
2461 ssh_gotdata(ssh, (unsigned char *)data, len);
2462 if (ssh->state == SSH_STATE_CLOSED) {
2463 ssh_do_close(ssh, TRUE);
2469 static void ssh_sent(Plug plug, int bufsize)
2471 Ssh ssh = (Ssh) plug;
2473 * If the send backlog on the SSH socket itself clears, we
2474 * should unthrottle the whole world if it was throttled.
2476 if (bufsize < SSH_MAX_BACKLOG)
2477 ssh_throttle_all(ssh, 0, bufsize);
2481 * Connect to specified host and port.
2482 * Returns an error message, or NULL on success.
2483 * Also places the canonical host name into `realhost'. It must be
2484 * freed by the caller.
2486 static const char *connect_to_host(Ssh ssh, char *host, int port,
2487 char **realhost, int nodelay, int keepalive)
2489 static const struct plug_function_table fn_table = {
2500 ssh->savedhost = snewn(1 + strlen(host), char);
2501 if (!ssh->savedhost)
2502 fatalbox("Out of memory");
2503 strcpy(ssh->savedhost, host);
2506 port = 22; /* default ssh port */
2507 ssh->savedport = port;
2512 logeventf(ssh, "Looking up host \"%s\"%s", host,
2513 (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
2514 (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
2515 addr = name_lookup(host, port, realhost, &ssh->cfg,
2516 ssh->cfg.addressfamily);
2517 if ((err = sk_addr_error(addr)) != NULL) {
2525 ssh->fn = &fn_table;
2526 ssh->s = new_connection(addr, *realhost, port,
2527 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
2528 if ((err = sk_socket_error(ssh->s)) != NULL) {
2530 notify_remote_exit(ssh->frontend);
2538 * Throttle or unthrottle the SSH connection.
2540 static void ssh1_throttle(Ssh ssh, int adjust)
2542 int old_count = ssh->v1_throttle_count;
2543 ssh->v1_throttle_count += adjust;
2544 assert(ssh->v1_throttle_count >= 0);
2545 if (ssh->v1_throttle_count && !old_count) {
2546 sk_set_frozen(ssh->s, 1);
2547 } else if (!ssh->v1_throttle_count && old_count) {
2548 sk_set_frozen(ssh->s, 0);
2553 * Throttle or unthrottle _all_ local data streams (for when sends
2554 * on the SSH connection itself back up).
2556 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2559 struct ssh_channel *c;
2561 if (enable == ssh->throttled_all)
2563 ssh->throttled_all = enable;
2564 ssh->overall_bufsize = bufsize;
2567 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2569 case CHAN_MAINSESSION:
2571 * This is treated separately, outside the switch.
2575 x11_override_throttle(c->u.x11.s, enable);
2578 /* Agent channels require no buffer management. */
2581 pfd_override_throttle(c->u.pfd.s, enable);
2588 * Username and password input, abstracted off into routines
2589 * reusable in several places - even between SSH1 and SSH2.
2592 /* Set up a username or password input loop on a given buffer. */
2593 static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2595 ssh->userpass_input_buffer = buffer;
2596 ssh->userpass_input_buflen = buflen;
2597 ssh->userpass_input_bufpos = 0;
2598 ssh->userpass_input_echo = echo;
2602 * Process some terminal data in the course of username/password
2603 * input. Returns >0 for success (line of input returned in
2604 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2605 * for inconclusive (keep waiting for more input please).
2607 static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2612 switch (c = *in++) {
2615 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2616 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2621 if (ssh->userpass_input_bufpos > 0) {
2622 if (ssh->userpass_input_echo)
2623 c_write_str(ssh, "\b \b");
2624 ssh->userpass_input_bufpos--;
2629 while (ssh->userpass_input_bufpos > 0) {
2630 if (ssh->userpass_input_echo)
2631 c_write_str(ssh, "\b \b");
2632 ssh->userpass_input_bufpos--;
2641 * This simplistic check for printability is disabled
2642 * when we're doing password input, because some people
2643 * have control characters in their passwords.o
2645 if ((!ssh->userpass_input_echo ||
2646 (c >= ' ' && c <= '~') ||
2647 ((unsigned char) c >= 160))
2648 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2649 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2650 if (ssh->userpass_input_echo)
2651 c_write(ssh, &c, 1);
2659 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
2661 Ssh ssh = (Ssh) sshv;
2663 ssh->agent_response = reply;
2664 ssh->agent_response_len = replylen;
2666 if (ssh->version == 1)
2667 do_ssh1_login(ssh, NULL, -1, NULL);
2669 do_ssh2_authconn(ssh, NULL, -1, NULL);
2672 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
2674 struct ssh_channel *c = (struct ssh_channel *)cv;
2676 void *sentreply = reply;
2679 /* Fake SSH_AGENT_FAILURE. */
2680 sentreply = "\0\0\0\1\5";
2683 if (ssh->version == 2) {
2684 ssh2_add_channel_data(c, sentreply, replylen);
2687 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2688 PKT_INT, c->remoteid,
2691 PKT_DATA, sentreply, replylen,
2700 * Handle the key exchange and user authentication phases.
2702 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2703 struct Packet *pktin)
2706 unsigned char cookie[8], *ptr;
2707 struct RSAKey servkey, hostkey;
2708 struct MD5Context md5c;
2709 struct do_ssh1_login_state {
2711 unsigned char *rsabuf, *keystr1, *keystr2;
2712 unsigned long supported_ciphers_mask, supported_auths_mask;
2713 int tried_publickey, tried_agent;
2714 int tis_auth_refused, ccard_auth_refused;
2715 unsigned char session_id[16];
2718 void *publickey_blob;
2719 int publickey_bloblen;
2725 unsigned char request[5], *response, *p;
2734 crState(do_ssh1_login_state);
2736 crBegin(ssh->do_ssh1_login_crstate);
2741 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
2742 bombout(("Public key packet not received"));
2746 logevent("Received public keys");
2748 ptr = ssh_pkt_getdata(pktin, 8);
2750 bombout(("SSH1 public key packet stopped before random cookie"));
2753 memcpy(cookie, ptr, 8);
2755 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2756 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
2757 bombout(("Failed to read SSH1 public keys from public key packet"));
2762 * Log the host key fingerprint.
2766 logevent("Host key fingerprint is:");
2767 strcpy(logmsg, " ");
2768 hostkey.comment = NULL;
2769 rsa_fingerprint(logmsg + strlen(logmsg),
2770 sizeof(logmsg) - strlen(logmsg), &hostkey);
2774 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2775 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2776 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
2778 ssh->v1_local_protoflags =
2779 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2780 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2783 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2784 MD5Update(&md5c, s->keystr1, servkey.bytes);
2785 MD5Update(&md5c, cookie, 8);
2786 MD5Final(s->session_id, &md5c);
2788 for (i = 0; i < 32; i++)
2789 ssh->session_key[i] = random_byte();
2792 * Verify that the `bits' and `bytes' parameters match.
2794 if (hostkey.bits > hostkey.bytes * 8 ||
2795 servkey.bits > servkey.bytes * 8) {
2796 bombout(("SSH1 public keys were badly formatted"));
2800 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2802 s->rsabuf = snewn(s->len, unsigned char);
2804 fatalbox("Out of memory");
2807 * Verify the host key.
2811 * First format the key into a string.
2813 int len = rsastr_len(&hostkey);
2814 char fingerprint[100];
2815 char *keystr = snewn(len, char);
2817 fatalbox("Out of memory");
2818 rsastr_fmt(keystr, &hostkey);
2819 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2820 verify_ssh_host_key(ssh->frontend,
2821 ssh->savedhost, ssh->savedport, "rsa", keystr,
2826 for (i = 0; i < 32; i++) {
2827 s->rsabuf[i] = ssh->session_key[i];
2829 s->rsabuf[i] ^= s->session_id[i];
2832 if (hostkey.bytes > servkey.bytes) {
2833 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2835 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2837 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
2839 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2842 bombout(("SSH1 public key encryptions failed due to bad formatting"));
2846 logevent("Encrypted session key");
2849 int cipher_chosen = 0, warn = 0;
2850 char *cipher_string = NULL;
2852 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2853 int next_cipher = ssh->cfg.ssh_cipherlist[i];
2854 if (next_cipher == CIPHER_WARN) {
2855 /* If/when we choose a cipher, warn about it */
2857 } else if (next_cipher == CIPHER_AES) {
2858 /* XXX Probably don't need to mention this. */
2859 logevent("AES not supported in SSH1, skipping");
2861 switch (next_cipher) {
2862 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
2863 cipher_string = "3DES"; break;
2864 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
2865 cipher_string = "Blowfish"; break;
2866 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
2867 cipher_string = "single-DES"; break;
2869 if (s->supported_ciphers_mask & (1 << s->cipher_type))
2873 if (!cipher_chosen) {
2874 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2875 bombout(("Server violates SSH 1 protocol by not "
2876 "supporting 3DES encryption"));
2878 /* shouldn't happen */
2879 bombout(("No supported ciphers found"));
2883 /* Warn about chosen cipher if necessary. */
2885 sk_set_frozen(ssh->s, 1);
2886 askalg(ssh->frontend, "cipher", cipher_string);
2887 sk_set_frozen(ssh->s, 0);
2891 switch (s->cipher_type) {
2892 case SSH_CIPHER_3DES:
2893 logevent("Using 3DES encryption");
2895 case SSH_CIPHER_DES:
2896 logevent("Using single-DES encryption");
2898 case SSH_CIPHER_BLOWFISH:
2899 logevent("Using Blowfish encryption");
2903 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2904 PKT_CHAR, s->cipher_type,
2905 PKT_DATA, cookie, 8,
2906 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2907 PKT_DATA, s->rsabuf, s->len,
2908 PKT_INT, ssh->v1_local_protoflags, PKT_END);
2910 logevent("Trying to enable encryption...");
2914 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2915 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2917 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2918 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
2919 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
2921 ssh->crcda_ctx = crcda_make_context();
2922 logevent("Installing CRC compensation attack detector");
2924 if (servkey.modulus) {
2925 sfree(servkey.modulus);
2926 servkey.modulus = NULL;
2928 if (servkey.exponent) {
2929 sfree(servkey.exponent);
2930 servkey.exponent = NULL;
2932 if (hostkey.modulus) {
2933 sfree(hostkey.modulus);
2934 hostkey.modulus = NULL;
2936 if (hostkey.exponent) {
2937 sfree(hostkey.exponent);
2938 hostkey.exponent = NULL;
2942 if (pktin->type != SSH1_SMSG_SUCCESS) {
2943 bombout(("Encryption not successfully enabled"));
2947 logevent("Successfully started encryption");
2951 if (!*ssh->cfg.username) {
2952 if (ssh_get_line && !ssh_getline_pw_only) {
2953 if (!ssh_get_line("login as: ",
2954 s->username, sizeof(s->username), FALSE)) {
2956 * get_line failed to get a username.
2959 logevent("No username provided. Abandoning session.");
2960 ssh->close_expected = TRUE;
2961 ssh_closing((Plug)ssh, NULL, 0, 0);
2965 int ret; /* need not be kept over crReturn */
2966 c_write_str(ssh, "login as: ");
2969 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
2971 crWaitUntil(!pktin);
2972 ret = process_userpass_input(ssh, in, inlen);
2976 c_write_str(ssh, "\r\n");
2979 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
2980 s->username[sizeof(s->username)-1] = '\0';
2983 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
2985 char userlog[22 + sizeof(s->username)];
2986 sprintf(userlog, "Sent username \"%s\"", s->username);
2988 if (flags & FLAG_INTERACTIVE &&
2989 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2990 strcat(userlog, "\r\n");
2991 c_write_str(ssh, userlog);
2998 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
2999 /* We must not attempt PK auth. Pretend we've already tried it. */
3000 s->tried_publickey = s->tried_agent = 1;
3002 s->tried_publickey = s->tried_agent = 0;
3004 s->tis_auth_refused = s->ccard_auth_refused = 0;
3005 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
3006 if (!filename_is_null(ssh->cfg.keyfile)) {
3007 if (!rsakey_pubblob(&ssh->cfg.keyfile,
3008 &s->publickey_blob, &s->publickey_bloblen, NULL))
3009 s->publickey_blob = NULL;
3011 s->publickey_blob = NULL;
3013 while (pktin->type == SSH1_SMSG_FAILURE) {
3014 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
3016 if (agent_exists() && !s->tried_agent) {
3018 * Attempt RSA authentication using Pageant.
3024 logevent("Pageant is running. Requesting keys.");
3026 /* Request the keys held by the agent. */
3027 PUT_32BIT(s->request, 1);
3028 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
3029 if (!agent_query(s->request, 5, &r, &s->responselen,
3030 ssh_agent_callback, ssh)) {
3034 bombout(("Unexpected data from server while waiting"
3035 " for agent response"));
3038 } while (pktin || inlen > 0);
3039 r = ssh->agent_response;
3040 s->responselen = ssh->agent_response_len;
3042 s->response = (unsigned char *) r;
3043 if (s->response && s->responselen >= 5 &&
3044 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3045 s->p = s->response + 5;
3046 s->nkeys = GET_32BIT(s->p);
3050 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
3053 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
3056 sprintf(buf, "Trying Pageant key #%d", s->keyi);
3059 if (s->publickey_blob &&
3060 !memcmp(s->p, s->publickey_blob,
3061 s->publickey_bloblen)) {
3062 logevent("This key matches configured key file");
3063 s->tried_publickey = 1;
3068 do { /* do while (0) to make breaking easy */
3069 n = ssh1_read_bignum
3070 (s->p, s->responselen-(s->p-s->response),
3075 n = ssh1_read_bignum
3076 (s->p, s->responselen-(s->p-s->response),
3081 if (s->responselen - (s->p-s->response) < 4)
3083 s->commentlen = GET_32BIT(s->p);
3085 if (s->responselen - (s->p-s->response) <
3088 s->commentp = (char *)s->p;
3089 s->p += s->commentlen;
3093 logevent("Pageant key list packet was truncated");
3097 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3098 PKT_BIGNUM, s->key.modulus, PKT_END);
3100 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3101 logevent("Key refused");
3104 logevent("Received RSA challenge");
3105 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3106 bombout(("Server's RSA challenge was badly formatted"));
3111 char *agentreq, *q, *ret;
3114 len = 1 + 4; /* message type, bit count */
3115 len += ssh1_bignum_length(s->key.exponent);
3116 len += ssh1_bignum_length(s->key.modulus);
3117 len += ssh1_bignum_length(s->challenge);
3118 len += 16; /* session id */
3119 len += 4; /* response format */
3120 agentreq = snewn(4 + len, char);
3121 PUT_32BIT(agentreq, len);
3123 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
3124 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
3126 q += ssh1_write_bignum(q, s->key.exponent);
3127 q += ssh1_write_bignum(q, s->key.modulus);
3128 q += ssh1_write_bignum(q, s->challenge);
3129 memcpy(q, s->session_id, 16);
3131 PUT_32BIT(q, 1); /* response format */
3132 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3133 ssh_agent_callback, ssh)) {
3138 bombout(("Unexpected data from server"
3139 " while waiting for agent"
3143 } while (pktin || inlen > 0);
3144 vret = ssh->agent_response;
3145 retlen = ssh->agent_response_len;
3150 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3151 logevent("Sending Pageant's response");
3152 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3153 PKT_DATA, ret + 5, 16,
3157 if (pktin->type == SSH1_SMSG_SUCCESS) {
3159 ("Pageant's response accepted");
3160 if (flags & FLAG_VERBOSE) {
3161 c_write_str(ssh, "Authenticated using"
3163 c_write(ssh, s->commentp,
3165 c_write_str(ssh, "\" from agent\r\n");
3170 ("Pageant's response not accepted");
3173 ("Pageant failed to answer challenge");
3177 logevent("No reply received from Pageant");
3180 freebn(s->key.exponent);
3181 freebn(s->key.modulus);
3182 freebn(s->challenge);
3191 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
3192 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
3194 if (ssh->cfg.try_tis_auth &&
3195 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3196 !s->tis_auth_refused) {
3197 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
3198 logevent("Requested TIS authentication");
3199 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
3201 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
3202 logevent("TIS authentication declined");
3203 if (flags & FLAG_INTERACTIVE)
3204 c_write_str(ssh, "TIS authentication refused.\r\n");
3205 s->tis_auth_refused = 1;
3211 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3213 bombout(("TIS challenge packet was badly formed"));
3216 logevent("Received TIS challenge");
3217 if (challengelen > sizeof(s->prompt) - 1)
3218 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3219 memcpy(s->prompt, challenge, challengelen);
3220 /* Prompt heuristic comes from OpenSSH */
3221 strncpy(s->prompt + challengelen,
3222 memchr(s->prompt, '\n', challengelen) ?
3223 "": "\r\nResponse: ",
3224 (sizeof s->prompt) - challengelen);
3225 s->prompt[(sizeof s->prompt) - 1] = '\0';
3228 if (ssh->cfg.try_tis_auth &&
3229 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3230 !s->ccard_auth_refused) {
3231 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
3232 logevent("Requested CryptoCard authentication");
3233 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
3235 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
3236 logevent("CryptoCard authentication declined");
3237 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3238 s->ccard_auth_refused = 1;
3244 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3246 bombout(("CryptoCard challenge packet was badly formed"));
3249 logevent("Received CryptoCard challenge");
3250 if (challengelen > sizeof(s->prompt) - 1)
3251 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3252 memcpy(s->prompt, challenge, challengelen);
3253 strncpy(s->prompt + challengelen,
3254 memchr(s->prompt, '\n', challengelen) ?
3255 "" : "\r\nResponse: ",
3256 sizeof(s->prompt) - challengelen);
3257 s->prompt[sizeof(s->prompt) - 1] = '\0';
3260 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3261 sprintf(s->prompt, "%.90s@%.90s's password: ",
3262 s->username, ssh->savedhost);
3264 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3265 char *comment = NULL;
3268 if (flags & FLAG_VERBOSE)
3269 c_write_str(ssh, "Trying public key authentication.\r\n");
3270 logeventf(ssh, "Trying public key \"%s\"",
3271 filename_to_str(&ssh->cfg.keyfile));
3272 type = key_type(&ssh->cfg.keyfile);
3273 if (type != SSH_KEYTYPE_SSH1) {
3274 sprintf(msgbuf, "Key is of wrong type (%s)",
3275 key_type_to_str(type));
3277 c_write_str(ssh, msgbuf);
3278 c_write_str(ssh, "\r\n");
3279 s->tried_publickey = 1;
3282 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
3283 if (flags & FLAG_VERBOSE)
3284 c_write_str(ssh, "No passphrase required.\r\n");
3287 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
3292 * Show password prompt, having first obtained it via a TIS
3293 * or CryptoCard exchange if we're doing TIS or CryptoCard
3297 if (!ssh_get_line(s->prompt, s->password,
3298 sizeof(s->password), TRUE)) {
3300 * get_line failed to get a password (for example
3301 * because one was supplied on the command line
3302 * which has already failed to work). Terminate.
3304 send_packet(ssh, SSH1_MSG_DISCONNECT,
3305 PKT_STR, "No more passwords available to try",
3307 logevent("Unable to authenticate");
3308 connection_fatal(ssh->frontend, "Unable to authenticate");
3309 ssh->close_expected = TRUE;
3310 ssh_closing((Plug)ssh, NULL, 0, 0);
3314 /* Prompt may have come from server. We've munged it a bit, so
3315 * we know it to be zero-terminated at least once. */
3316 int ret; /* need not be saved over crReturn */
3317 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3320 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
3322 crWaitUntil(!pktin);
3323 ret = process_userpass_input(ssh, in, inlen);
3327 c_write_str(ssh, "\r\n");
3331 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3333 * Try public key authentication with the specified
3336 s->tried_publickey = 1;
3339 const char *error = NULL;
3340 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3343 c_write_str(ssh, "Couldn't load private key from ");
3344 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
3345 c_write_str(ssh, " (");
3346 c_write_str(ssh, error);
3347 c_write_str(ssh, ").\r\n");
3348 continue; /* go and try password */
3351 c_write_str(ssh, "Wrong passphrase.\r\n");
3352 s->tried_publickey = 0;
3353 continue; /* try again */
3358 * Send a public key attempt.
3360 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3361 PKT_BIGNUM, s->key.modulus, PKT_END);
3364 if (pktin->type == SSH1_SMSG_FAILURE) {
3365 c_write_str(ssh, "Server refused our public key.\r\n");
3366 continue; /* go and try password */
3368 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3369 bombout(("Bizarre response to offer of public key"));
3375 unsigned char buffer[32];
3376 Bignum challenge, response;
3378 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3379 bombout(("Server's RSA challenge was badly formatted"));
3382 response = rsadecrypt(challenge, &s->key);
3383 freebn(s->key.private_exponent);/* burn the evidence */
3385 for (i = 0; i < 32; i++) {
3386 buffer[i] = bignum_byte(response, 31 - i);
3390 MD5Update(&md5c, buffer, 32);
3391 MD5Update(&md5c, s->session_id, 16);
3392 MD5Final(buffer, &md5c);
3394 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3395 PKT_DATA, buffer, 16, PKT_END);
3402 if (pktin->type == SSH1_SMSG_FAILURE) {
3403 if (flags & FLAG_VERBOSE)
3404 c_write_str(ssh, "Failed to authenticate with"
3405 " our public key.\r\n");
3406 continue; /* go and try password */
3407 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3408 bombout(("Bizarre response to RSA authentication response"));
3412 break; /* we're through! */
3414 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3416 * Defence against traffic analysis: we send a
3417 * whole bunch of packets containing strings of
3418 * different lengths. One of these strings is the
3419 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3420 * The others are all random data in
3421 * SSH1_MSG_IGNORE packets. This way a passive
3422 * listener can't tell which is the password, and
3423 * hence can't deduce the password length.
3425 * Anybody with a password length greater than 16
3426 * bytes is going to have enough entropy in their
3427 * password that a listener won't find it _that_
3428 * much help to know how long it is. So what we'll
3431 * - if password length < 16, we send 15 packets
3432 * containing string lengths 1 through 15
3434 * - otherwise, we let N be the nearest multiple
3435 * of 8 below the password length, and send 8
3436 * packets containing string lengths N through
3437 * N+7. This won't obscure the order of
3438 * magnitude of the password length, but it will
3439 * introduce a bit of extra uncertainty.
3441 * A few servers (the old 1.2.18 through 1.2.22)
3442 * can't deal with SSH1_MSG_IGNORE. For these
3443 * servers, we need an alternative defence. We make
3444 * use of the fact that the password is interpreted
3445 * as a C string: so we can append a NUL, then some
3448 * One server (a Cisco one) can deal with neither
3449 * SSH1_MSG_IGNORE _nor_ a padded password string.
3450 * For this server we are left with no defences
3451 * against password length sniffing.
3453 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
3455 * The server can deal with SSH1_MSG_IGNORE, so
3456 * we can use the primary defence.
3458 int bottom, top, pwlen, i;
3461 pwlen = strlen(s->password);
3463 bottom = 0; /* zero length passwords are OK! :-) */
3466 bottom = pwlen & ~7;
3470 assert(pwlen >= bottom && pwlen <= top);
3472 randomstr = snewn(top + 1, char);
3474 for (i = bottom; i <= top; i++) {
3476 defer_packet(ssh, s->pwpkt_type,
3477 PKTT_PASSWORD, PKT_STR, s->password,
3478 PKTT_OTHER, PKT_END);
3480 for (j = 0; j < i; j++) {
3482 randomstr[j] = random_byte();
3483 } while (randomstr[j] == '\0');
3485 randomstr[i] = '\0';
3486 defer_packet(ssh, SSH1_MSG_IGNORE,
3487 PKT_STR, randomstr, PKT_END);
3490 logevent("Sending password with camouflage packets");
3491 ssh_pkt_defersend(ssh);
3494 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3496 * The server can't deal with SSH1_MSG_IGNORE
3497 * but can deal with padded passwords, so we
3498 * can use the secondary defence.
3504 len = strlen(s->password);
3505 if (len < sizeof(string)) {
3507 strcpy(string, s->password);
3508 len++; /* cover the zero byte */
3509 while (len < sizeof(string)) {
3510 string[len++] = (char) random_byte();
3515 logevent("Sending length-padded password");
3516 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3517 PKT_INT, len, PKT_DATA, ss, len,
3518 PKTT_OTHER, PKT_END);
3521 * The server has _both_
3522 * BUG_CHOKES_ON_SSH1_IGNORE and
3523 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3524 * therefore nothing we can do.
3527 len = strlen(s->password);
3528 logevent("Sending unpadded password");
3529 send_packet(ssh, s->pwpkt_type,
3530 PKTT_PASSWORD, PKT_INT, len,
3531 PKT_DATA, s->password, len,
3532 PKTT_OTHER, PKT_END);
3535 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3536 PKT_STR, s->password, PKTT_OTHER, PKT_END);
3539 logevent("Sent password");
3540 memset(s->password, 0, strlen(s->password));
3542 if (pktin->type == SSH1_SMSG_FAILURE) {
3543 if (flags & FLAG_VERBOSE)
3544 c_write_str(ssh, "Access denied\r\n");
3545 logevent("Authentication refused");
3546 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3547 bombout(("Strange packet received, type %d", pktin->type));
3552 logevent("Authentication successful");
3557 void sshfwd_close(struct ssh_channel *c)
3561 if (ssh->state != SSH_STATE_SESSION) {
3562 assert(ssh->state == SSH_STATE_CLOSED);
3566 if (c && !c->closes) {
3568 * If the channel's remoteid is -1, we have sent
3569 * CHANNEL_OPEN for this channel, but it hasn't even been
3570 * acknowledged by the server. So we must set a close flag
3571 * on it now, and then when the server acks the channel
3572 * open, we can close it then.
3574 if (((int)c->remoteid) != -1) {
3575 if (ssh->version == 1) {
3576 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3579 struct Packet *pktout;
3580 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3581 ssh2_pkt_adduint32(pktout, c->remoteid);
3582 ssh2_pkt_send(ssh, pktout);
3585 c->closes = 1; /* sent MSG_CLOSE */
3586 if (c->type == CHAN_X11) {
3588 logevent("Forwarded X11 connection terminated");
3589 } else if (c->type == CHAN_SOCKDATA ||
3590 c->type == CHAN_SOCKDATA_DORMANT) {
3592 logevent("Forwarded port closed");
3597 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3601 if (ssh->state != SSH_STATE_SESSION) {
3602 assert(ssh->state == SSH_STATE_CLOSED);
3606 if (ssh->version == 1) {
3607 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3608 PKT_INT, c->remoteid,
3610 PKT_INT, len, PKT_DATA, buf, len,
3611 PKTT_OTHER, PKT_END);
3613 * In SSH1 we can return 0 here - implying that forwarded
3614 * connections are never individually throttled - because
3615 * the only circumstance that can cause throttling will be
3616 * the whole SSH connection backing up, in which case
3617 * _everything_ will be throttled as a whole.
3621 ssh2_add_channel_data(c, buf, len);
3622 return ssh2_try_send(c);
3626 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3630 if (ssh->state != SSH_STATE_SESSION) {
3631 assert(ssh->state == SSH_STATE_CLOSED);
3635 if (ssh->version == 1) {
3636 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3637 c->v.v1.throttling = 0;
3638 ssh1_throttle(ssh, -1);
3641 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3645 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
3647 struct queued_handler *qh = ssh->qhead;
3651 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
3654 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
3655 ssh->packet_dispatch[qh->msg1] = NULL;
3658 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
3659 ssh->packet_dispatch[qh->msg2] = NULL;
3663 ssh->qhead = qh->next;
3665 if (ssh->qhead->msg1 > 0) {
3666 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
3667 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
3669 if (ssh->qhead->msg2 > 0) {
3670 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
3671 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
3674 ssh->qhead = ssh->qtail = NULL;
3675 ssh->packet_dispatch[pktin->type] = NULL;
3678 qh->handler(ssh, pktin, qh->ctx);
3683 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
3684 chandler_fn_t handler, void *ctx)
3686 struct queued_handler *qh;
3688 qh = snew(struct queued_handler);
3691 qh->handler = handler;
3695 if (ssh->qtail == NULL) {
3699 assert(ssh->packet_dispatch[qh->msg1] == NULL);
3700 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
3703 assert(ssh->packet_dispatch[qh->msg2] == NULL);
3704 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
3707 ssh->qtail->next = qh;
3712 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
3714 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
3716 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
3717 SSH2_MSG_REQUEST_SUCCESS)) {
3718 logeventf(ssh, "Remote port forwarding from %s enabled",
3721 logeventf(ssh, "Remote port forwarding from %s refused",
3724 rpf = del234(ssh->rportfwds, pf);
3730 static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
3732 const char *portfwd_strptr = cfg->portfwd;
3733 struct ssh_portfwd *epf;
3736 if (!ssh->portfwds) {
3737 ssh->portfwds = newtree234(ssh_portcmp);
3740 * Go through the existing port forwardings and tag them
3741 * with status==DESTROY. Any that we want to keep will be
3742 * re-enabled (status==KEEP) as we go through the
3743 * configuration and find out which bits are the same as
3746 struct ssh_portfwd *epf;
3748 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3749 epf->status = DESTROY;
3752 while (*portfwd_strptr) {
3753 char address_family, type;
3754 int sport,dport,sserv,dserv;
3755 char sports[256], dports[256], saddr[256], host[256];
3758 address_family = 'A';
3760 if (*portfwd_strptr == 'A' ||
3761 *portfwd_strptr == '4' ||
3762 *portfwd_strptr == '6')
3763 address_family = *portfwd_strptr++;
3764 if (*portfwd_strptr == 'L' ||
3765 *portfwd_strptr == 'R' ||
3766 *portfwd_strptr == 'D')
3767 type = *portfwd_strptr++;
3772 while (*portfwd_strptr && *portfwd_strptr != '\t') {
3773 if (*portfwd_strptr == ':') {
3775 * We've seen a colon in the middle of the
3776 * source port number. This means that
3777 * everything we've seen until now is the
3778 * source _address_, so we'll move it into
3779 * saddr and start sports from the beginning
3784 if (ssh->version == 1 && type == 'R') {
3785 logeventf(ssh, "SSH1 cannot handle remote source address "
3786 "spec \"%s\"; ignoring", sports);
3788 strcpy(saddr, sports);
3791 if (n < 255) sports[n++] = *portfwd_strptr++;
3795 if (*portfwd_strptr == '\t')
3798 while (*portfwd_strptr && *portfwd_strptr != ':') {
3799 if (n < 255) host[n++] = *portfwd_strptr++;
3802 if (*portfwd_strptr == ':')
3805 while (*portfwd_strptr) {
3806 if (n < 255) dports[n++] = *portfwd_strptr++;
3810 dport = atoi(dports);
3814 dport = net_service_lookup(dports);
3816 logeventf(ssh, "Service lookup failed for destination"
3817 " port \"%s\"", dports);
3821 while (*portfwd_strptr) portfwd_strptr++;
3823 portfwd_strptr++; /* eat the NUL and move to next one */
3825 sport = atoi(sports);
3829 sport = net_service_lookup(sports);
3831 logeventf(ssh, "Service lookup failed for source"
3832 " port \"%s\"", sports);
3835 if (sport && dport) {
3836 /* Set up a description of the source port. */
3837 struct ssh_portfwd *pfrec, *epfrec;
3839 pfrec = snew(struct ssh_portfwd);
3841 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
3842 pfrec->sserv = sserv ? dupstr(sports) : NULL;
3843 pfrec->sport = sport;
3844 pfrec->daddr = *host ? dupstr(host) : NULL;
3845 pfrec->dserv = dserv ? dupstr(dports) : NULL;
3846 pfrec->dport = dport;
3847 pfrec->local = NULL;
3848 pfrec->remote = NULL;
3849 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
3850 address_family == '6' ? ADDRTYPE_IPV6 :
3853 epfrec = add234(ssh->portfwds, pfrec);
3854 if (epfrec != pfrec) {
3856 * We already have a port forwarding with precisely
3857 * these parameters. Hence, no need to do anything;
3858 * simply tag the existing one as KEEP.
3860 epfrec->status = KEEP;
3861 free_portfwd(pfrec);
3863 pfrec->status = CREATE;
3869 * Now go through and destroy any port forwardings which were
3872 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3873 if (epf->status == DESTROY) {
3876 message = dupprintf("%s port forwarding from %s%s%d",
3877 epf->type == 'L' ? "local" :
3878 epf->type == 'R' ? "remote" : "dynamic",
3879 epf->saddr ? epf->saddr : "",
3880 epf->saddr ? ":" : "",
3883 if (epf->type != 'D') {
3884 char *msg2 = dupprintf("%s to %s:%d", message,
3885 epf->daddr, epf->dport);
3890 logeventf(ssh, "Cancelling %s", message);
3894 struct ssh_rportfwd *rpf = epf->remote;
3895 struct Packet *pktout;
3898 * Cancel the port forwarding at the server
3901 if (ssh->version == 1) {
3903 * We cannot cancel listening ports on the
3904 * server side in SSH1! There's no message
3905 * to support it. Instead, we simply remove
3906 * the rportfwd record from the local end
3907 * so that any connections the server tries
3908 * to make on it are rejected.
3911 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
3912 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
3913 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
3915 ssh2_pkt_addstring(pktout, epf->saddr);
3916 } else if (ssh->cfg.rport_acceptall) {
3917 ssh2_pkt_addstring(pktout, "0.0.0.0");
3919 ssh2_pkt_addstring(pktout, "127.0.0.1");
3921 ssh2_pkt_adduint32(pktout, epf->sport);
3922 ssh2_pkt_send(ssh, pktout);
3925 del234(ssh->rportfwds, rpf);
3927 } else if (epf->local) {
3928 pfd_terminate(epf->local);
3931 delpos234(ssh->portfwds, i);
3933 i--; /* so we don't skip one in the list */
3937 * And finally, set up any new port forwardings (status==CREATE).
3939 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3940 if (epf->status == CREATE) {
3941 char *sportdesc, *dportdesc;
3942 sportdesc = dupprintf("%s%s%s%s%d%s",
3943 epf->saddr ? epf->saddr : "",
3944 epf->saddr ? ":" : "",
3945 epf->sserv ? epf->sserv : "",
3946 epf->sserv ? "(" : "",
3948 epf->sserv ? ")" : "");
3949 if (epf->type == 'D') {
3952 dportdesc = dupprintf("%s:%s%s%d%s",
3954 epf->dserv ? epf->dserv : "",
3955 epf->dserv ? "(" : "",
3957 epf->dserv ? ")" : "");
3960 if (epf->type == 'L') {
3961 const char *err = pfd_addforward(epf->daddr, epf->dport,
3962 epf->saddr, epf->sport,
3965 epf->addressfamily);
3967 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
3968 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
3969 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
3970 sportdesc, dportdesc,
3971 err ? " failed: " : "", err ? err : "");
3972 } else if (epf->type == 'D') {
3973 const char *err = pfd_addforward(NULL, -1,
3974 epf->saddr, epf->sport,
3977 epf->addressfamily);
3979 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
3980 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
3981 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
3983 err ? " failed: " : "", err ? err : "");
3985 struct ssh_rportfwd *pf;
3988 * Ensure the remote port forwardings tree exists.
3990 if (!ssh->rportfwds) {
3991 if (ssh->version == 1)
3992 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3994 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
3997 pf = snew(struct ssh_rportfwd);
3998 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
3999 pf->dhost[lenof(pf->dhost)-1] = '\0';
4000 pf->dport = epf->dport;
4001 pf->sport = epf->sport;
4002 if (add234(ssh->rportfwds, pf) != pf) {
4003 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
4004 epf->daddr, epf->dport);
4007 logeventf(ssh, "Requesting remote port %s"
4008 " forward to %s", sportdesc, dportdesc);
4010 pf->sportdesc = sportdesc;
4015 if (ssh->version == 1) {
4016 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
4017 PKT_INT, epf->sport,
4018 PKT_STR, epf->daddr,
4019 PKT_INT, epf->dport,
4021 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4023 ssh_rportfwd_succfail, pf);
4025 struct Packet *pktout;
4026 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4027 ssh2_pkt_addstring(pktout, "tcpip-forward");
4028 ssh2_pkt_addbool(pktout, 1);/* want reply */
4030 ssh2_pkt_addstring(pktout, epf->saddr);
4031 } else if (ssh->cfg.rport_acceptall) {
4032 ssh2_pkt_addstring(pktout, "0.0.0.0");
4034 ssh2_pkt_addstring(pktout, "127.0.0.1");
4036 ssh2_pkt_adduint32(pktout, epf->sport);
4037 ssh2_pkt_send(ssh, pktout);
4039 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4040 SSH2_MSG_REQUEST_FAILURE,
4041 ssh_rportfwd_succfail, pf);
4050 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4053 int stringlen, bufsize;
4055 ssh_pkt_getstring(pktin, &string, &stringlen);
4056 if (string == NULL) {
4057 bombout(("Incoming terminal data packet was badly formed"));
4061 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4063 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4064 ssh->v1_stdout_throttling = 1;
4065 ssh1_throttle(ssh, +1);
4069 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4071 /* Remote side is trying to open a channel to talk to our
4072 * X-Server. Give them back a local channel number. */
4073 struct ssh_channel *c;
4074 int remoteid = ssh_pkt_getuint32(pktin);
4076 logevent("Received X11 connect request");
4077 /* Refuse if X11 forwarding is disabled. */
4078 if (!ssh->X11_fwd_enabled) {
4079 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4080 PKT_INT, remoteid, PKT_END);
4081 logevent("Rejected X11 connect request");
4083 c = snew(struct ssh_channel);
4086 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
4087 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
4088 logevent("Opening X11 forward connection failed");
4090 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4091 PKT_INT, remoteid, PKT_END);
4094 ("Opening X11 forward connection succeeded");
4095 c->remoteid = remoteid;
4096 c->localid = alloc_channel_id(ssh);
4098 c->v.v1.throttling = 0;
4099 c->type = CHAN_X11; /* identify channel type */
4100 add234(ssh->channels, c);
4101 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4102 PKT_INT, c->remoteid, PKT_INT,
4103 c->localid, PKT_END);
4104 logevent("Opened X11 forward channel");
4109 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4111 /* Remote side is trying to open a channel to talk to our
4112 * agent. Give them back a local channel number. */
4113 struct ssh_channel *c;
4114 int remoteid = ssh_pkt_getuint32(pktin);
4116 /* Refuse if agent forwarding is disabled. */
4117 if (!ssh->agentfwd_enabled) {
4118 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4119 PKT_INT, remoteid, PKT_END);
4121 c = snew(struct ssh_channel);
4123 c->remoteid = remoteid;
4124 c->localid = alloc_channel_id(ssh);
4126 c->v.v1.throttling = 0;
4127 c->type = CHAN_AGENT; /* identify channel type */
4128 c->u.a.lensofar = 0;
4129 add234(ssh->channels, c);
4130 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4131 PKT_INT, c->remoteid, PKT_INT, c->localid,
4136 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4138 /* Remote side is trying to open a channel to talk to a
4139 * forwarded port. Give them back a local channel number. */
4140 struct ssh_channel *c;
4141 struct ssh_rportfwd pf, *pfp;
4144 char *host, buf[1024];
4146 c = snew(struct ssh_channel);
4149 remoteid = ssh_pkt_getuint32(pktin);
4150 ssh_pkt_getstring(pktin, &host, &hostsize);
4151 port = ssh_pkt_getuint32(pktin);
4153 if (hostsize >= lenof(pf.dhost))
4154 hostsize = lenof(pf.dhost)-1;
4155 memcpy(pf.dhost, host, hostsize);
4156 pf.dhost[hostsize] = '\0';
4158 pfp = find234(ssh->rportfwds, &pf, NULL);
4161 sprintf(buf, "Rejected remote port open request for %s:%d",
4164 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4165 PKT_INT, remoteid, PKT_END);
4167 sprintf(buf, "Received remote port open request for %s:%d",
4170 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
4171 c, &ssh->cfg, pfp->pfrec->addressfamily);
4174 sprintf(buf, "Port open failed: %s", e);
4177 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4178 PKT_INT, remoteid, PKT_END);
4180 c->remoteid = remoteid;
4181 c->localid = alloc_channel_id(ssh);
4183 c->v.v1.throttling = 0;
4184 c->type = CHAN_SOCKDATA; /* identify channel type */
4185 add234(ssh->channels, c);
4186 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4187 PKT_INT, c->remoteid, PKT_INT,
4188 c->localid, PKT_END);
4189 logevent("Forwarded port opened successfully");
4194 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4196 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4197 unsigned int localid = ssh_pkt_getuint32(pktin);
4198 struct ssh_channel *c;
4200 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4201 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4202 c->remoteid = localid;
4203 c->type = CHAN_SOCKDATA;
4204 c->v.v1.throttling = 0;
4205 pfd_confirm(c->u.pfd.s);
4208 if (c && c->closes) {
4210 * We have a pending close on this channel,
4211 * which we decided on before the server acked
4212 * the channel open. So now we know the
4213 * remoteid, we can close it again.
4215 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4216 PKT_INT, c->remoteid, PKT_END);
4220 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4222 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4223 struct ssh_channel *c;
4225 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4226 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4227 logevent("Forwarded connection refused by server");
4228 pfd_close(c->u.pfd.s);
4229 del234(ssh->channels, c);
4234 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4236 /* Remote side closes a channel. */
4237 unsigned i = ssh_pkt_getuint32(pktin);
4238 struct ssh_channel *c;
4239 c = find234(ssh->channels, &i, ssh_channelfind);
4240 if (c && ((int)c->remoteid) != -1) {
4243 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4245 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4246 logevent("Forwarded X11 connection terminated");
4247 assert(c->u.x11.s != NULL);
4248 x11_close(c->u.x11.s);
4251 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4252 logevent("Forwarded port closed");
4253 assert(c->u.pfd.s != NULL);
4254 pfd_close(c->u.pfd.s);
4258 c->closes |= (closetype << 2); /* seen this message */
4259 if (!(c->closes & closetype)) {
4260 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4262 c->closes |= closetype; /* sent it too */
4265 if (c->closes == 15) {
4266 del234(ssh->channels, c);
4270 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4271 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4272 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4277 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4279 /* Data sent down one of our channels. */
4280 int i = ssh_pkt_getuint32(pktin);
4283 struct ssh_channel *c;
4285 ssh_pkt_getstring(pktin, &p, &len);
4287 c = find234(ssh->channels, &i, ssh_channelfind);
4292 bufsize = x11_send(c->u.x11.s, p, len);
4295 bufsize = pfd_send(c->u.pfd.s, p, len);
4298 /* Data for an agent message. Buffer it. */
4300 if (c->u.a.lensofar < 4) {
4301 unsigned int l = min(4 - c->u.a.lensofar, len);
4302 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4306 c->u.a.lensofar += l;
4308 if (c->u.a.lensofar == 4) {
4310 4 + GET_32BIT(c->u.a.msglen);
4311 c->u.a.message = snewn(c->u.a.totallen,
4313 memcpy(c->u.a.message, c->u.a.msglen, 4);
4315 if (c->u.a.lensofar >= 4 && len > 0) {
4317 min(c->u.a.totallen - c->u.a.lensofar,
4319 memcpy(c->u.a.message + c->u.a.lensofar, p,
4323 c->u.a.lensofar += l;
4325 if (c->u.a.lensofar == c->u.a.totallen) {
4328 if (agent_query(c->u.a.message,
4331 ssh_agentf_callback, c))
4332 ssh_agentf_callback(c, reply, replylen);
4333 sfree(c->u.a.message);
4334 c->u.a.lensofar = 0;
4337 bufsize = 0; /* agent channels never back up */
4340 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4341 c->v.v1.throttling = 1;
4342 ssh1_throttle(ssh, +1);
4347 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
4350 ssh->exitcode = ssh_pkt_getuint32(pktin);
4351 sprintf(buf, "Server sent command exit status %d",
4354 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4356 * In case `helpful' firewalls or proxies tack
4357 * extra human-readable text on the end of the
4358 * session which we might mistake for another
4359 * encrypted packet, we close the session once
4360 * we've sent EXIT_CONFIRMATION.
4362 ssh->close_expected = TRUE;
4363 ssh_closing((Plug)ssh, NULL, 0, 0);
4366 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
4367 struct Packet *pktin)
4369 crBegin(ssh->do_ssh1_connection_crstate);
4371 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
4372 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
4373 ssh1_smsg_stdout_stderr_data;
4375 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
4376 ssh1_msg_channel_open_confirmation;
4377 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
4378 ssh1_msg_channel_open_failure;
4379 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
4380 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
4381 ssh1_msg_channel_close;
4382 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
4383 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
4385 if (ssh->cfg.agentfwd && agent_exists()) {
4386 logevent("Requesting agent forwarding");
4387 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
4391 if (pktin->type != SSH1_SMSG_SUCCESS
4392 && pktin->type != SSH1_SMSG_FAILURE) {
4393 bombout(("Protocol confusion"));
4395 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4396 logevent("Agent forwarding refused");
4398 logevent("Agent forwarding enabled");
4399 ssh->agentfwd_enabled = TRUE;
4400 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
4404 if (ssh->cfg.x11_forward) {
4405 char proto[20], data[64];
4406 logevent("Requesting X11 forwarding");
4407 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
4408 data, sizeof(data), ssh->cfg.x11_auth);
4409 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
4410 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
4411 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4412 PKT_STR, proto, PKT_STR, data,
4413 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
4416 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4417 PKT_STR, proto, PKT_STR, data, PKT_END);
4422 if (pktin->type != SSH1_SMSG_SUCCESS
4423 && pktin->type != SSH1_SMSG_FAILURE) {
4424 bombout(("Protocol confusion"));
4426 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4427 logevent("X11 forwarding refused");
4429 logevent("X11 forwarding enabled");
4430 ssh->X11_fwd_enabled = TRUE;
4431 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
4435 ssh_setup_portfwd(ssh, &ssh->cfg);
4436 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
4438 if (!ssh->cfg.nopty) {
4439 /* Unpick the terminal-speed string. */
4440 /* XXX perhaps we should allow no speeds to be sent. */
4441 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4442 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
4443 /* Send the pty request. */
4444 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
4445 PKT_STR, ssh->cfg.termtype,
4446 PKT_INT, ssh->term_height,
4447 PKT_INT, ssh->term_width,
4448 PKT_INT, 0, PKT_INT, 0, /* width,height in pixels */
4449 PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */
4450 PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */
4451 PKT_CHAR, 0, PKT_END);
4452 ssh->state = SSH_STATE_INTERMED;
4456 if (pktin->type != SSH1_SMSG_SUCCESS
4457 && pktin->type != SSH1_SMSG_FAILURE) {
4458 bombout(("Protocol confusion"));
4460 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4461 c_write_str(ssh, "Server refused to allocate pty\r\n");
4462 ssh->editing = ssh->echoing = 1;
4464 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
4465 ssh->ospeed, ssh->ispeed);
4467 ssh->editing = ssh->echoing = 1;
4470 if (ssh->cfg.compression) {
4471 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
4475 if (pktin->type != SSH1_SMSG_SUCCESS
4476 && pktin->type != SSH1_SMSG_FAILURE) {
4477 bombout(("Protocol confusion"));
4479 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4480 c_write_str(ssh, "Server refused to compress\r\n");
4482 logevent("Started compression");
4483 ssh->v1_compressing = TRUE;
4484 ssh->cs_comp_ctx = zlib_compress_init();
4485 logevent("Initialised zlib (RFC1950) compression");
4486 ssh->sc_comp_ctx = zlib_decompress_init();
4487 logevent("Initialised zlib (RFC1950) decompression");
4491 * Start the shell or command.
4493 * Special case: if the first-choice command is an SSH2
4494 * subsystem (hence not usable here) and the second choice
4495 * exists, we fall straight back to that.
4498 char *cmd = ssh->cfg.remote_cmd_ptr;
4500 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4501 cmd = ssh->cfg.remote_cmd_ptr2;
4502 ssh->fallback_cmd = TRUE;
4505 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
4507 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
4508 logevent("Started session");
4511 ssh->state = SSH_STATE_SESSION;
4512 if (ssh->size_needed)
4513 ssh_size(ssh, ssh->term_width, ssh->term_height);
4514 if (ssh->eof_needed)
4515 ssh_special(ssh, TS_EOF);
4518 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
4520 ssh->channels = newtree234(ssh_channelcmp);
4524 * By this point, most incoming packets are already being
4525 * handled by the dispatch table, and we need only pay
4526 * attention to the unusual ones.
4531 if (pktin->type == SSH1_SMSG_SUCCESS) {
4532 /* may be from EXEC_SHELL on some servers */
4533 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4534 /* may be from EXEC_SHELL on some servers
4535 * if no pty is available or in other odd cases. Ignore */
4537 bombout(("Strange packet received: type %d", pktin->type));
4542 int len = min(inlen, 512);
4543 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4544 PKT_INT, len, PKT_DATA, in, len,
4545 PKTT_OTHER, PKT_END);
4556 * Handle the top-level SSH2 protocol.
4558 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4563 ssh_pkt_getstring(pktin, &msg, &msglen);
4564 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
4569 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4571 /* log reason code in disconnect message */
4575 ssh_pkt_getstring(pktin, &msg, &msglen);
4576 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4579 void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
4581 /* Do nothing, because we're ignoring it! Duhh. */
4584 static void ssh1_protocol_setup(Ssh ssh)
4589 * Most messages are handled by the coroutines.
4591 for (i = 0; i < 256; i++)
4592 ssh->packet_dispatch[i] = NULL;
4595 * These special message types we install handlers for.
4597 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4598 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4599 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4602 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
4603 struct Packet *pktin)
4605 unsigned char *in=(unsigned char*)vin;
4606 if (ssh->state == SSH_STATE_CLOSED)
4609 if (pktin && ssh->packet_dispatch[pktin->type]) {
4610 ssh->packet_dispatch[pktin->type](ssh, pktin);
4614 if (!ssh->protocol_initial_phase_done) {
4615 if (do_ssh1_login(ssh, in, inlen, pktin))
4616 ssh->protocol_initial_phase_done = TRUE;
4621 do_ssh1_connection(ssh, in, inlen, pktin);
4625 * Utility routine for decoding comma-separated strings in KEXINIT.
4627 static int in_commasep_string(char *needle, char *haystack, int haylen)
4630 if (!needle || !haystack) /* protect against null pointers */
4632 needlen = strlen(needle);
4635 * Is it at the start of the string?
4637 if (haylen >= needlen && /* haystack is long enough */
4638 !memcmp(needle, haystack, needlen) && /* initial match */
4639 (haylen == needlen || haystack[needlen] == ',')
4640 /* either , or EOS follows */
4644 * If not, search for the next comma and resume after that.
4645 * If no comma found, terminate.
4647 while (haylen > 0 && *haystack != ',')
4648 haylen--, haystack++;
4651 haylen--, haystack++; /* skip over comma itself */
4656 * SSH2 key creation method.
4658 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4659 unsigned char *sessid, char chr,
4660 unsigned char *keyspace)
4663 /* First 20 bytes. */
4665 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4667 SHA_Bytes(&s, H, 20);
4668 SHA_Bytes(&s, &chr, 1);
4669 SHA_Bytes(&s, sessid, 20);
4670 SHA_Final(&s, keyspace);
4671 /* Next 20 bytes. */
4673 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4675 SHA_Bytes(&s, H, 20);
4676 SHA_Bytes(&s, keyspace, 20);
4677 SHA_Final(&s, keyspace + 20);
4681 * Handle the SSH2 transport layer.
4683 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
4684 struct Packet *pktin)
4686 unsigned char *in = (unsigned char *)vin;
4687 struct do_ssh2_transport_state {
4688 int nbits, pbits, warn;
4689 Bignum p, g, e, f, K;
4690 int kex_init_value, kex_reply_value;
4691 const struct ssh_mac **maclist;
4693 const struct ssh2_cipher *cscipher_tobe;
4694 const struct ssh2_cipher *sccipher_tobe;
4695 const struct ssh_mac *csmac_tobe;
4696 const struct ssh_mac *scmac_tobe;
4697 const struct ssh_compress *cscomp_tobe;
4698 const struct ssh_compress *sccomp_tobe;
4699 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4700 int hostkeylen, siglen;
4701 void *hkey; /* actual host key */
4702 unsigned char exchange_hash[20];
4703 int n_preferred_kex;
4704 const struct ssh_kex *preferred_kex[KEX_MAX];
4705 int n_preferred_ciphers;
4706 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4707 const struct ssh_compress *preferred_comp;
4708 int got_session_id, activated_authconn;
4709 struct Packet *pktout;
4711 crState(do_ssh2_transport_state);
4713 crBegin(ssh->do_ssh2_transport_crstate);
4715 s->cscipher_tobe = s->sccipher_tobe = NULL;
4716 s->csmac_tobe = s->scmac_tobe = NULL;
4717 s->cscomp_tobe = s->sccomp_tobe = NULL;
4719 s->got_session_id = s->activated_authconn = FALSE;
4722 * Be prepared to work around the buggy MAC problem.
4724 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4725 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
4727 s->maclist = macs, s->nmacs = lenof(macs);
4730 ssh->pkt_ctx &= ~SSH2_PKTCTX_KEX_MASK;
4732 int i, j, commalist_started;
4735 * Set up the preferred key exchange. (NULL => warn below here)
4737 s->n_preferred_kex = 0;
4738 for (i = 0; i < KEX_MAX; i++) {
4739 switch (ssh->cfg.ssh_kexlist[i]) {
4741 s->preferred_kex[s->n_preferred_kex++] =
4742 &ssh_diffiehellman_gex;
4745 s->preferred_kex[s->n_preferred_kex++] =
4746 &ssh_diffiehellman_group14;
4749 s->preferred_kex[s->n_preferred_kex++] =
4750 &ssh_diffiehellman_group1;
4753 /* Flag for later. Don't bother if it's the last in
4755 if (i < KEX_MAX - 1) {
4756 s->preferred_kex[s->n_preferred_kex++] = NULL;
4763 * Set up the preferred ciphers. (NULL => warn below here)
4765 s->n_preferred_ciphers = 0;
4766 for (i = 0; i < CIPHER_MAX; i++) {
4767 switch (ssh->cfg.ssh_cipherlist[i]) {
4768 case CIPHER_BLOWFISH:
4769 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
4772 if (ssh->cfg.ssh2_des_cbc) {
4773 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
4777 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
4780 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
4783 /* Flag for later. Don't bother if it's the last in
4785 if (i < CIPHER_MAX - 1) {
4786 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
4793 * Set up preferred compression.
4795 if (ssh->cfg.compression)
4796 s->preferred_comp = &ssh_zlib;
4798 s->preferred_comp = &ssh_comp_none;
4801 * Enable queueing of outgoing auth- or connection-layer
4802 * packets while we are in the middle of a key exchange.
4804 ssh->queueing = TRUE;
4807 * Flag that KEX is in progress.
4809 ssh->kex_in_progress = TRUE;
4812 * Construct and send our key exchange packet.
4814 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
4815 for (i = 0; i < 16; i++)
4816 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
4817 /* List key exchange algorithms. */
4818 ssh2_pkt_addstring_start(s->pktout);
4819 commalist_started = 0;
4820 for (i = 0; i < s->n_preferred_kex; i++) {
4821 const struct ssh_kex *k = s->preferred_kex[i];
4822 if (!k) continue; /* warning flag */
4823 if (commalist_started)
4824 ssh2_pkt_addstring_str(s->pktout, ",");
4825 ssh2_pkt_addstring_str(s->pktout, s->preferred_kex[i]->name);
4826 commalist_started = 1;
4828 /* List server host key algorithms. */
4829 ssh2_pkt_addstring_start(s->pktout);
4830 for (i = 0; i < lenof(hostkey_algs); i++) {
4831 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
4832 if (i < lenof(hostkey_algs) - 1)
4833 ssh2_pkt_addstring_str(s->pktout, ",");
4835 /* List client->server encryption algorithms. */
4836 ssh2_pkt_addstring_start(s->pktout);
4837 commalist_started = 0;
4838 for (i = 0; i < s->n_preferred_ciphers; i++) {
4839 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4840 if (!c) continue; /* warning flag */
4841 for (j = 0; j < c->nciphers; j++) {
4842 if (commalist_started)
4843 ssh2_pkt_addstring_str(s->pktout, ",");
4844 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
4845 commalist_started = 1;
4848 /* List server->client encryption algorithms. */
4849 ssh2_pkt_addstring_start(s->pktout);
4850 commalist_started = 0;
4851 for (i = 0; i < s->n_preferred_ciphers; i++) {
4852 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4853 if (!c) continue; /* warning flag */
4854 for (j = 0; j < c->nciphers; j++) {
4855 if (commalist_started)
4856 ssh2_pkt_addstring_str(s->pktout, ",");
4857 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
4858 commalist_started = 1;
4861 /* List client->server MAC algorithms. */
4862 ssh2_pkt_addstring_start(s->pktout);
4863 for (i = 0; i < s->nmacs; i++) {
4864 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
4865 if (i < s->nmacs - 1)
4866 ssh2_pkt_addstring_str(s->pktout, ",");
4868 /* List server->client MAC algorithms. */
4869 ssh2_pkt_addstring_start(s->pktout);
4870 for (i = 0; i < s->nmacs; i++) {
4871 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
4872 if (i < s->nmacs - 1)
4873 ssh2_pkt_addstring_str(s->pktout, ",");
4875 /* List client->server compression algorithms. */
4876 ssh2_pkt_addstring_start(s->pktout);
4877 assert(lenof(compressions) > 1);
4878 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
4879 for (i = 0; i < lenof(compressions); i++) {
4880 const struct ssh_compress *c = compressions[i];
4881 if (c != s->preferred_comp) {
4882 ssh2_pkt_addstring_str(s->pktout, ",");
4883 ssh2_pkt_addstring_str(s->pktout, c->name);
4886 /* List server->client compression algorithms. */
4887 ssh2_pkt_addstring_start(s->pktout);
4888 assert(lenof(compressions) > 1);
4889 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
4890 for (i = 0; i < lenof(compressions); i++) {
4891 const struct ssh_compress *c = compressions[i];
4892 if (c != s->preferred_comp) {
4893 ssh2_pkt_addstring_str(s->pktout, ",");
4894 ssh2_pkt_addstring_str(s->pktout, c->name);
4897 /* List client->server languages. Empty list. */
4898 ssh2_pkt_addstring_start(s->pktout);
4899 /* List server->client languages. Empty list. */
4900 ssh2_pkt_addstring_start(s->pktout);
4901 /* First KEX packet does _not_ follow, because we're not that brave. */
4902 ssh2_pkt_addbool(s->pktout, FALSE);
4904 ssh2_pkt_adduint32(s->pktout, 0);
4907 ssh->exhash = ssh->exhashbase;
4908 sha_string(&ssh->exhash, s->pktout->data + 5, s->pktout->length - 5);
4910 ssh2_pkt_send_noqueue(ssh, s->pktout);
4914 if (pktin->length > 5)
4915 sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5);
4918 * Now examine the other side's KEXINIT to see what we're up
4925 if (pktin->type != SSH2_MSG_KEXINIT) {
4926 bombout(("expected key exchange packet from server"));
4930 ssh->hostkey = NULL;
4931 s->cscipher_tobe = NULL;
4932 s->sccipher_tobe = NULL;
4933 s->csmac_tobe = NULL;
4934 s->scmac_tobe = NULL;
4935 s->cscomp_tobe = NULL;
4936 s->sccomp_tobe = NULL;
4937 pktin->savedpos += 16; /* skip garbage cookie */
4938 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
4940 for (i = 0; i < s->n_preferred_kex; i++) {
4941 const struct ssh_kex *k = s->preferred_kex[i];
4944 } else if (in_commasep_string(k->name, str, len)) {
4949 sk_set_frozen(ssh->s, 1);
4950 askalg(ssh->frontend, "key-exchange algorithm",
4952 sk_set_frozen(ssh->s, 0);
4958 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
4959 str ? str : "(null)"));
4962 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
4963 for (i = 0; i < lenof(hostkey_algs); i++) {
4964 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
4965 ssh->hostkey = hostkey_algs[i];
4969 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
4971 for (i = 0; i < s->n_preferred_ciphers; i++) {
4972 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4976 for (j = 0; j < c->nciphers; j++) {
4977 if (in_commasep_string(c->list[j]->name, str, len)) {
4978 s->cscipher_tobe = c->list[j];
4983 if (s->cscipher_tobe) {
4985 sk_set_frozen(ssh->s, 1);
4986 askalg(ssh->frontend, "client-to-server cipher",
4987 s->cscipher_tobe->name);
4988 sk_set_frozen(ssh->s, 0);
4993 if (!s->cscipher_tobe) {
4994 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
4995 str ? str : "(null)"));
4999 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
5001 for (i = 0; i < s->n_preferred_ciphers; i++) {
5002 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5006 for (j = 0; j < c->nciphers; j++) {
5007 if (in_commasep_string(c->list[j]->name, str, len)) {
5008 s->sccipher_tobe = c->list[j];
5013 if (s->sccipher_tobe) {
5015 sk_set_frozen(ssh->s, 1);
5016 askalg(ssh->frontend, "server-to-client cipher",
5017 s->sccipher_tobe->name);
5018 sk_set_frozen(ssh->s, 0);
5023 if (!s->sccipher_tobe) {
5024 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
5025 str ? str : "(null)"));
5029 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
5030 for (i = 0; i < s->nmacs; i++) {
5031 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5032 s->csmac_tobe = s->maclist[i];
5036 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
5037 for (i = 0; i < s->nmacs; i++) {
5038 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5039 s->scmac_tobe = s->maclist[i];
5043 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
5044 for (i = 0; i < lenof(compressions) + 1; i++) {
5045 const struct ssh_compress *c =
5046 i == 0 ? s->preferred_comp : compressions[i - 1];
5047 if (in_commasep_string(c->name, str, len)) {
5052 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
5053 for (i = 0; i < lenof(compressions) + 1; i++) {
5054 const struct ssh_compress *c =
5055 i == 0 ? s->preferred_comp : compressions[i - 1];
5056 if (in_commasep_string(c->name, str, len)) {
5064 * Work out the number of bits of key we will need from the key
5065 * exchange. We start with the maximum key length of either
5071 csbits = s->cscipher_tobe->keylen;
5072 scbits = s->sccipher_tobe->keylen;
5073 s->nbits = (csbits > scbits ? csbits : scbits);
5075 /* The keys only have 160-bit entropy, since they're based on
5076 * a SHA-1 hash. So cap the key size at 160 bits. */
5081 * If we're doing Diffie-Hellman group exchange, start by
5082 * requesting a group.
5084 if (!ssh->kex->pdata) {
5085 logevent("Doing Diffie-Hellman group exchange");
5086 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
5088 * Work out how big a DH group we will need to allow that
5091 s->pbits = 512 << ((s->nbits - 1) / 64);
5092 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5093 ssh2_pkt_adduint32(s->pktout, s->pbits);
5094 ssh2_pkt_send_noqueue(ssh, s->pktout);
5097 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
5098 bombout(("expected key exchange group packet from server"));
5101 s->p = ssh2_pkt_getmp(pktin);
5102 s->g = ssh2_pkt_getmp(pktin);
5103 if (!s->p || !s->g) {
5104 bombout(("unable to read mp-ints from incoming group packet"));
5107 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
5108 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5109 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
5111 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP;
5112 ssh->kex_ctx = dh_setup_group(ssh->kex);
5113 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5114 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
5115 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5116 ssh->kex->groupname);
5119 logevent("Doing Diffie-Hellman key exchange");
5121 * Now generate and send e for Diffie-Hellman.
5123 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
5124 s->pktout = ssh2_pkt_init(s->kex_init_value);
5125 ssh2_pkt_addmp(s->pktout, s->e);
5126 ssh2_pkt_send_noqueue(ssh, s->pktout);
5129 if (pktin->type != s->kex_reply_value) {
5130 bombout(("expected key exchange reply packet from server"));
5133 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5134 s->f = ssh2_pkt_getmp(pktin);
5136 bombout(("unable to parse key exchange reply packet"));
5139 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
5141 s->K = dh_find_K(ssh->kex_ctx, s->f);
5143 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
5144 if (ssh->kex == &ssh_diffiehellman_gex) {
5145 sha_uint32(&ssh->exhash, s->pbits);
5146 sha_mpint(&ssh->exhash, s->p);
5147 sha_mpint(&ssh->exhash, s->g);
5149 sha_mpint(&ssh->exhash, s->e);
5150 sha_mpint(&ssh->exhash, s->f);
5151 sha_mpint(&ssh->exhash, s->K);
5152 SHA_Final(&ssh->exhash, s->exchange_hash);
5154 dh_cleanup(ssh->kex_ctx);
5155 ssh->kex_ctx = NULL;
5158 debug(("Exchange hash is:\n"));
5159 dmemdump(s->exchange_hash, 20);
5162 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5164 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
5165 (char *)s->exchange_hash, 20)) {
5166 bombout(("Server's host key did not match the signature supplied"));
5171 * Authenticate remote host: verify host key. (We've already
5172 * checked the signature of the exchange hash.)
5174 s->keystr = ssh->hostkey->fmtkey(s->hkey);
5175 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
5176 sk_set_frozen(ssh->s, 1);
5177 verify_ssh_host_key(ssh->frontend,
5178 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
5179 s->keystr, s->fingerprint);
5180 sk_set_frozen(ssh->s, 0);
5181 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5182 logevent("Host key fingerprint is:");
5183 logevent(s->fingerprint);
5185 sfree(s->fingerprint);
5187 ssh->hostkey->freekey(s->hkey);
5190 * The exchange hash from the very first key exchange is also
5191 * the session id, used in session key construction and
5194 if (!s->got_session_id) {
5195 memcpy(ssh->v2_session_id, s->exchange_hash,
5196 sizeof(s->exchange_hash));
5197 s->got_session_id = TRUE;
5201 * Send SSH2_MSG_NEWKEYS.
5203 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
5204 ssh2_pkt_send_noqueue(ssh, s->pktout);
5205 ssh->outgoing_data_size = 0; /* start counting from here */
5208 * We've sent client NEWKEYS, so create and initialise
5209 * client-to-server session keys.
5211 if (ssh->cs_cipher_ctx)
5212 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
5213 ssh->cscipher = s->cscipher_tobe;
5214 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
5216 if (ssh->cs_mac_ctx)
5217 ssh->csmac->free_context(ssh->cs_mac_ctx);
5218 ssh->csmac = s->csmac_tobe;
5219 ssh->cs_mac_ctx = ssh->csmac->make_context();
5221 if (ssh->cs_comp_ctx)
5222 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
5223 ssh->cscomp = s->cscomp_tobe;
5224 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
5227 * Set IVs on client-to-server keys. Here we use the exchange
5228 * hash from the _first_ key exchange.
5231 unsigned char keyspace[40];
5232 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
5233 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
5234 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
5235 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
5236 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
5237 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
5240 logeventf(ssh, "Initialised %.200s client->server encryption",
5241 ssh->cscipher->text_name);
5242 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
5243 ssh->csmac->text_name);
5244 if (ssh->cscomp->text_name)
5245 logeventf(ssh, "Initialised %s compression",
5246 ssh->cscomp->text_name);
5249 * Now our end of the key exchange is complete, we can send all
5250 * our queued higher-layer packets.
5252 ssh->queueing = FALSE;
5253 ssh2_pkt_queuesend(ssh);
5256 * Expect SSH2_MSG_NEWKEYS from server.
5259 if (pktin->type != SSH2_MSG_NEWKEYS) {
5260 bombout(("expected new-keys packet from server"));
5263 ssh->incoming_data_size = 0; /* start counting from here */
5266 * We've seen server NEWKEYS, so create and initialise
5267 * server-to-client session keys.
5269 if (ssh->sc_cipher_ctx)
5270 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
5271 ssh->sccipher = s->sccipher_tobe;
5272 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
5274 if (ssh->sc_mac_ctx)
5275 ssh->scmac->free_context(ssh->sc_mac_ctx);
5276 ssh->scmac = s->scmac_tobe;
5277 ssh->sc_mac_ctx = ssh->scmac->make_context();
5279 if (ssh->sc_comp_ctx)
5280 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
5281 ssh->sccomp = s->sccomp_tobe;
5282 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
5285 * Set IVs on server-to-client keys. Here we use the exchange
5286 * hash from the _first_ key exchange.
5289 unsigned char keyspace[40];
5290 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
5291 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
5292 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
5293 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
5294 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
5295 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
5297 logeventf(ssh, "Initialised %.200s server->client encryption",
5298 ssh->sccipher->text_name);
5299 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
5300 ssh->scmac->text_name);
5301 if (ssh->sccomp->text_name)
5302 logeventf(ssh, "Initialised %s decompression",
5303 ssh->sccomp->text_name);
5306 * Free key exchange data.
5310 if (ssh->kex == &ssh_diffiehellman_gex) {
5316 * Key exchange is over. Loop straight back round if we have a
5317 * deferred rekey reason.
5319 if (ssh->deferred_rekey_reason) {
5320 logevent(ssh->deferred_rekey_reason);
5322 ssh->deferred_rekey_reason = NULL;
5323 goto begin_key_exchange;
5327 * Otherwise, schedule a timer for our next rekey.
5329 ssh->kex_in_progress = FALSE;
5330 ssh->last_rekey = GETTICKCOUNT();
5331 if (ssh->cfg.ssh_rekey_time != 0)
5332 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5336 * If this is the first key exchange phase, we must pass the
5337 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
5338 * wants to see it but because it will need time to initialise
5339 * itself before it sees an actual packet. In subsequent key
5340 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
5341 * it would only confuse the layer above.
5343 if (s->activated_authconn) {
5346 s->activated_authconn = TRUE;
5349 * Now we're encrypting. Begin returning 1 to the protocol main
5350 * function so that other things can run on top of the
5351 * transport. If we ever see a KEXINIT, we must go back to the
5354 * We _also_ go back to the start if we see pktin==NULL and
5355 * inlen==-1, because this is a special signal meaning
5356 * `initiate client-driven rekey', and `in' contains a message
5357 * giving the reason for the rekey.
5359 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
5360 (!pktin && inlen == -1))) {
5365 logevent("Server initiated key re-exchange");
5368 * Special case: if the server bug is set that doesn't
5369 * allow rekeying, we give a different log message and
5370 * continue waiting. (If such a server _initiates_ a rekey,
5371 * we process it anyway!)
5373 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
5374 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
5376 /* Reset the counters, so that at least this message doesn't
5377 * hit the event log _too_ often. */
5378 ssh->outgoing_data_size = 0;
5379 ssh->incoming_data_size = 0;
5380 if (ssh->cfg.ssh_rekey_time != 0) {
5382 schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5385 goto wait_for_rekey; /* this is utterly horrid */
5387 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
5390 goto begin_key_exchange;
5396 * Add data to an SSH2 channel output buffer.
5398 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
5401 bufchain_add(&c->v.v2.outbuffer, buf, len);
5405 * Attempt to send data on an SSH2 channel.
5407 static int ssh2_try_send(struct ssh_channel *c)
5410 struct Packet *pktout;
5412 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
5415 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
5416 if ((unsigned)len > c->v.v2.remwindow)
5417 len = c->v.v2.remwindow;
5418 if ((unsigned)len > c->v.v2.remmaxpkt)
5419 len = c->v.v2.remmaxpkt;
5420 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
5421 ssh2_pkt_adduint32(pktout, c->remoteid);
5422 dont_log_data(ssh, pktout, PKTLOG_OMIT);
5423 ssh2_pkt_addstring_start(pktout);
5424 ssh2_pkt_addstring_data(pktout, data, len);
5425 end_log_omission(ssh, pktout);
5426 ssh2_pkt_send(ssh, pktout);
5427 bufchain_consume(&c->v.v2.outbuffer, len);
5428 c->v.v2.remwindow -= len;
5432 * After having sent as much data as we can, return the amount
5435 return bufchain_size(&c->v.v2.outbuffer);
5439 * Potentially enlarge the window on an SSH2 channel.
5441 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
5446 * Never send WINDOW_ADJUST for a channel that the remote side
5447 * already thinks it's closed; there's no point, since it won't
5448 * be sending any more data anyway.
5454 * Only send a WINDOW_ADJUST if there's significantly more window
5455 * available than the other end thinks there is. This saves us
5456 * sending a WINDOW_ADJUST for every character in a shell session.
5458 * "Significant" is arbitrarily defined as half the window size.
5460 if (newwin > c->v.v2.locwindow * 2) {
5461 struct Packet *pktout;
5463 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5464 ssh2_pkt_adduint32(pktout, c->remoteid);
5465 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
5466 ssh2_pkt_send(ssh, pktout);
5467 c->v.v2.locwindow = newwin;
5471 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
5473 unsigned i = ssh_pkt_getuint32(pktin);
5474 struct ssh_channel *c;
5475 c = find234(ssh->channels, &i, ssh_channelfind);
5476 if (c && !c->closes)
5477 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
5480 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
5484 unsigned i = ssh_pkt_getuint32(pktin);
5485 struct ssh_channel *c;
5486 c = find234(ssh->channels, &i, ssh_channelfind);
5488 return; /* nonexistent channel */
5489 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5490 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
5491 return; /* extended but not stderr */
5492 ssh_pkt_getstring(pktin, &data, &length);
5495 c->v.v2.locwindow -= length;
5497 case CHAN_MAINSESSION:
5499 from_backend(ssh->frontend, pktin->type ==
5500 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5504 bufsize = x11_send(c->u.x11.s, data, length);
5507 bufsize = pfd_send(c->u.pfd.s, data, length);
5510 while (length > 0) {
5511 if (c->u.a.lensofar < 4) {
5512 unsigned int l = min(4 - c->u.a.lensofar, length);
5513 memcpy(c->u.a.msglen + c->u.a.lensofar,
5517 c->u.a.lensofar += l;
5519 if (c->u.a.lensofar == 4) {
5521 4 + GET_32BIT(c->u.a.msglen);
5522 c->u.a.message = snewn(c->u.a.totallen,
5524 memcpy(c->u.a.message, c->u.a.msglen, 4);
5526 if (c->u.a.lensofar >= 4 && length > 0) {
5528 min(c->u.a.totallen - c->u.a.lensofar,
5530 memcpy(c->u.a.message + c->u.a.lensofar,
5534 c->u.a.lensofar += l;
5536 if (c->u.a.lensofar == c->u.a.totallen) {
5539 if (agent_query(c->u.a.message,
5542 ssh_agentf_callback, c))
5543 ssh_agentf_callback(c, reply, replylen);
5544 sfree(c->u.a.message);
5545 c->u.a.lensofar = 0;
5552 * If we are not buffering too much data,
5553 * enlarge the window again at the remote side.
5555 if (bufsize < OUR_V2_WINSIZE)
5556 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5560 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
5562 unsigned i = ssh_pkt_getuint32(pktin);
5563 struct ssh_channel *c;
5565 c = find234(ssh->channels, &i, ssh_channelfind);
5567 return; /* nonexistent channel */
5569 if (c->type == CHAN_X11) {
5571 * Remote EOF on an X11 channel means we should
5572 * wrap up and close the channel ourselves.
5574 x11_close(c->u.x11.s);
5576 } else if (c->type == CHAN_AGENT) {
5578 } else if (c->type == CHAN_SOCKDATA) {
5579 pfd_close(c->u.pfd.s);
5584 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
5586 unsigned i = ssh_pkt_getuint32(pktin);
5587 struct ssh_channel *c;
5588 struct Packet *pktout;
5590 c = find234(ssh->channels, &i, ssh_channelfind);
5591 if (!c || ((int)c->remoteid) == -1) {
5592 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5593 c ? "half-open" : "nonexistent", i));
5596 /* Do pre-close processing on the channel. */
5598 case CHAN_MAINSESSION:
5599 ssh->mainchan = NULL;
5600 update_specials_menu(ssh->frontend);
5603 if (c->u.x11.s != NULL)
5604 x11_close(c->u.x11.s);
5611 if (c->u.pfd.s != NULL)
5612 pfd_close(c->u.pfd.s);
5616 if (c->closes == 0) {
5617 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5618 ssh2_pkt_adduint32(pktout, c->remoteid);
5619 ssh2_pkt_send(ssh, pktout);
5621 del234(ssh->channels, c);
5622 bufchain_clear(&c->v.v2.outbuffer);
5626 * See if that was the last channel left open.
5627 * (This is only our termination condition if we're
5628 * not running in -N mode.)
5630 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
5631 logevent("All channels closed. Disconnecting");
5634 * We used to send SSH_MSG_DISCONNECT here,
5635 * because I'd believed that _every_ conforming
5636 * SSH2 connection had to end with a disconnect
5637 * being sent by at least one side; apparently
5638 * I was wrong and it's perfectly OK to
5639 * unceremoniously slam the connection shut
5640 * when you're done, and indeed OpenSSH feels
5641 * this is more polite than sending a
5642 * DISCONNECT. So now we don't.
5644 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5645 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
5646 ssh2_pkt_addstring(s->pktout, "All open channels closed");
5647 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
5648 ssh2_pkt_send_noqueue(ssh, s->pktout);
5650 ssh->close_expected = TRUE;
5651 ssh_closing((Plug)ssh, NULL, 0, 0);
5655 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5657 unsigned i = ssh_pkt_getuint32(pktin);
5658 struct ssh_channel *c;
5659 struct Packet *pktout;
5661 c = find234(ssh->channels, &i, ssh_channelfind);
5663 return; /* nonexistent channel */
5664 if (c->type != CHAN_SOCKDATA_DORMANT)
5665 return; /* dunno why they're confirming this */
5666 c->remoteid = ssh_pkt_getuint32(pktin);
5667 c->type = CHAN_SOCKDATA;
5668 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
5669 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
5671 pfd_confirm(c->u.pfd.s);
5674 * We have a pending close on this channel,
5675 * which we decided on before the server acked
5676 * the channel open. So now we know the
5677 * remoteid, we can close it again.
5679 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5680 ssh2_pkt_adduint32(pktout, c->remoteid);
5681 ssh2_pkt_send(ssh, pktout);
5685 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5687 static const char *const reasons[] = {
5688 "<unknown reason code>",
5689 "Administratively prohibited",
5691 "Unknown channel type",
5692 "Resource shortage",
5694 unsigned i = ssh_pkt_getuint32(pktin);
5695 unsigned reason_code;
5696 char *reason_string;
5699 struct ssh_channel *c;
5700 c = find234(ssh->channels, &i, ssh_channelfind);
5702 return; /* nonexistent channel */
5703 if (c->type != CHAN_SOCKDATA_DORMANT)
5704 return; /* dunno why they're failing this */
5706 reason_code = ssh_pkt_getuint32(pktin);
5707 if (reason_code >= lenof(reasons))
5708 reason_code = 0; /* ensure reasons[reason_code] in range */
5709 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
5710 message = dupprintf("Forwarded connection refused by"
5711 " server: %s [%.*s]", reasons[reason_code],
5712 reason_length, reason_string);
5716 pfd_close(c->u.pfd.s);
5718 del234(ssh->channels, c);
5722 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
5726 int typelen, want_reply;
5727 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
5728 struct ssh_channel *c;
5729 struct Packet *pktout;
5731 localid = ssh_pkt_getuint32(pktin);
5732 ssh_pkt_getstring(pktin, &type, &typelen);
5733 want_reply = ssh2_pkt_getbool(pktin);
5736 * First, check that the channel exists. Otherwise,
5737 * we can instantly disconnect with a rude message.
5739 c = find234(ssh->channels, &localid, ssh_channelfind);
5742 sprintf(buf, "Received channel request for nonexistent"
5743 " channel %d", localid);
5745 pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5746 ssh2_pkt_adduint32(pktout, SSH2_DISCONNECT_BY_APPLICATION);
5747 ssh2_pkt_addstring(pktout, buf);
5748 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5749 ssh2_pkt_send_noqueue(ssh, pktout);
5750 connection_fatal(ssh->frontend, "%s", buf);
5751 ssh->close_expected = TRUE;
5752 ssh_closing((Plug)ssh, NULL, 0, 0);
5757 * Having got the channel number, we now look at
5758 * the request type string to see if it's something
5761 if (c == ssh->mainchan) {
5763 * We recognise "exit-status" and "exit-signal" on
5764 * the primary channel.
5766 if (typelen == 11 &&
5767 !memcmp(type, "exit-status", 11)) {
5769 ssh->exitcode = ssh_pkt_getuint32(pktin);
5770 logeventf(ssh, "Server sent command exit status %d",
5772 reply = SSH2_MSG_CHANNEL_SUCCESS;
5774 } else if (typelen == 11 &&
5775 !memcmp(type, "exit-signal", 11)) {
5777 int is_plausible = TRUE, is_int = FALSE;
5778 char *fmt_sig = "", *fmt_msg = "";
5780 int msglen = 0, core = FALSE;
5781 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
5782 * provide an `int' for the signal, despite its
5783 * having been a `string' in the drafts since at
5784 * least 2001. (Fixed in session.c 1.147.) Try to
5785 * infer which we can safely parse it as. */
5787 unsigned char *p = pktin->body +
5789 long len = pktin->length - pktin->savedpos;
5790 unsigned long num = GET_32BIT(p); /* what is it? */
5791 /* If it's 0, it hardly matters; assume string */
5795 int maybe_int = FALSE, maybe_str = FALSE;
5796 #define CHECK_HYPOTHESIS(offset, result) \
5799 if (q >= 0 && q+4 <= len) { \
5800 q = q + 4 + GET_32BIT(p+q); \
5801 if (q >= 0 && q+4 <= len && \
5802 (q = q + 4 + GET_32BIT(p+q)) && q == len) \
5806 CHECK_HYPOTHESIS(4+1, maybe_int);
5807 CHECK_HYPOTHESIS(4+num+1, maybe_str);
5808 #undef CHECK_HYPOTHESIS
5809 if (maybe_int && !maybe_str)
5811 else if (!maybe_int && maybe_str)
5814 /* Crikey. Either or neither. Panic. */
5815 is_plausible = FALSE;
5820 /* Old non-standard OpenSSH. */
5821 int signum = ssh_pkt_getuint32(pktin);
5822 fmt_sig = dupprintf(" %d", signum);
5824 /* As per the drafts. */
5827 ssh_pkt_getstring(pktin, &sig, &siglen);
5828 /* Signal name isn't supposed to be blank, but
5829 * let's cope gracefully if it is. */
5831 fmt_sig = dupprintf(" \"%.*s\"",
5835 core = ssh2_pkt_getbool(pktin);
5836 ssh_pkt_getstring(pktin, &msg, &msglen);
5838 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
5840 /* ignore lang tag */
5841 } /* else don't attempt to parse */
5842 logeventf(ssh, "Server exited on signal%s%s%s",
5843 fmt_sig, core ? " (core dumped)" : "",
5845 if (*fmt_sig) sfree(fmt_sig);
5846 if (*fmt_msg) sfree(fmt_msg);
5847 reply = SSH2_MSG_CHANNEL_SUCCESS;
5852 * This is a channel request we don't know
5853 * about, so we now either ignore the request
5854 * or respond with CHANNEL_FAILURE, depending
5857 reply = SSH2_MSG_CHANNEL_FAILURE;
5860 pktout = ssh2_pkt_init(reply);
5861 ssh2_pkt_adduint32(pktout, c->remoteid);
5862 ssh2_pkt_send(ssh, pktout);
5866 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
5869 int typelen, want_reply;
5870 struct Packet *pktout;
5872 ssh_pkt_getstring(pktin, &type, &typelen);
5873 want_reply = ssh2_pkt_getbool(pktin);
5876 * We currently don't support any global requests
5877 * at all, so we either ignore the request or
5878 * respond with REQUEST_FAILURE, depending on
5882 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
5883 ssh2_pkt_send(ssh, pktout);
5887 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
5895 struct ssh_channel *c;
5896 unsigned remid, winsize, pktsize;
5897 struct Packet *pktout;
5899 ssh_pkt_getstring(pktin, &type, &typelen);
5900 c = snew(struct ssh_channel);
5903 remid = ssh_pkt_getuint32(pktin);
5904 winsize = ssh_pkt_getuint32(pktin);
5905 pktsize = ssh_pkt_getuint32(pktin);
5907 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5910 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5911 addrstr = snewn(peeraddrlen+1, char);
5912 memcpy(addrstr, peeraddr, peeraddrlen);
5913 addrstr[peeraddrlen] = '\0';
5914 peerport = ssh_pkt_getuint32(pktin);
5916 logeventf(ssh, "Received X11 connect request from %s:%d",
5919 if (!ssh->X11_fwd_enabled)
5920 error = "X11 forwarding is not enabled";
5921 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
5922 ssh->x11auth, addrstr, peerport,
5923 &ssh->cfg) != NULL) {
5924 error = "Unable to open an X11 connection";
5926 logevent("Opening X11 forward connection succeeded");
5931 } else if (typelen == 15 &&
5932 !memcmp(type, "forwarded-tcpip", 15)) {
5933 struct ssh_rportfwd pf, *realpf;
5936 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
5937 pf.sport = ssh_pkt_getuint32(pktin);
5938 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5939 peerport = ssh_pkt_getuint32(pktin);
5940 realpf = find234(ssh->rportfwds, &pf, NULL);
5941 logeventf(ssh, "Received remote port %d open request "
5942 "from %s:%d", pf.sport, peeraddr, peerport);
5943 if (realpf == NULL) {
5944 error = "Remote port is not recognised";
5946 const char *e = pfd_newconnect(&c->u.pfd.s,
5950 realpf->pfrec->addressfamily);
5951 logeventf(ssh, "Attempting to forward remote port to "
5952 "%s:%d", realpf->dhost, realpf->dport);
5954 logeventf(ssh, "Port open failed: %s", e);
5955 error = "Port open failed";
5957 logevent("Forwarded port opened successfully");
5958 c->type = CHAN_SOCKDATA;
5961 } else if (typelen == 22 &&
5962 !memcmp(type, "auth-agent@openssh.com", 3)) {
5963 if (!ssh->agentfwd_enabled)
5964 error = "Agent forwarding is not enabled";
5966 c->type = CHAN_AGENT; /* identify channel type */
5967 c->u.a.lensofar = 0;
5970 error = "Unsupported channel type requested";
5973 c->remoteid = remid;
5975 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
5976 ssh2_pkt_adduint32(pktout, c->remoteid);
5977 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
5978 ssh2_pkt_addstring(pktout, error);
5979 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5980 ssh2_pkt_send(ssh, pktout);
5981 logeventf(ssh, "Rejected channel open: %s", error);
5984 c->localid = alloc_channel_id(ssh);
5986 c->v.v2.locwindow = OUR_V2_WINSIZE;
5987 c->v.v2.remwindow = winsize;
5988 c->v.v2.remmaxpkt = pktsize;
5989 bufchain_init(&c->v.v2.outbuffer);
5990 add234(ssh->channels, c);
5991 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5992 ssh2_pkt_adduint32(pktout, c->remoteid);
5993 ssh2_pkt_adduint32(pktout, c->localid);
5994 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
5995 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
5996 ssh2_pkt_send(ssh, pktout);
6001 * Handle the SSH2 userauth and connection layers.
6003 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
6004 struct Packet *pktin)
6006 struct do_ssh2_authconn_state {
6008 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
6010 AUTH_KEYBOARD_INTERACTIVE
6014 AUTH_TYPE_PUBLICKEY,
6015 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
6016 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
6018 AUTH_TYPE_KEYBOARD_INTERACTIVE,
6019 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
6021 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
6022 int tried_pubkey_config, tried_agent;
6023 int kbd_inter_running, kbd_inter_refused;
6025 int num_prompts, curr_prompt, echo;
6030 void *publickey_blob;
6031 int publickey_bloblen;
6032 unsigned char request[5], *response, *p;
6036 char *pkblob, *alg, *commentp;
6037 int pklen, alglen, commentlen;
6038 int siglen, retlen, len;
6039 char *q, *agentreq, *ret;
6041 int num_env, env_left, env_ok;
6042 struct Packet *pktout;
6044 crState(do_ssh2_authconn_state);
6046 crBegin(ssh->do_ssh2_authconn_crstate);
6049 * Request userauth protocol, and await a response to it.
6051 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6052 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
6053 ssh2_pkt_send(ssh, s->pktout);
6054 crWaitUntilV(pktin);
6055 if (pktin->type != SSH2_MSG_SERVICE_ACCEPT) {
6056 bombout(("Server refused user authentication protocol"));
6061 * We repeat this whole loop, including the username prompt,
6062 * until we manage a successful authentication. If the user
6063 * types the wrong _password_, they can be sent back to the
6064 * beginning to try another username, if this is configured on.
6065 * (If they specify a username in the config, they are never
6066 * asked, even if they do give a wrong password.)
6068 * I think this best serves the needs of
6070 * - the people who have no configuration, no keys, and just
6071 * want to try repeated (username,password) pairs until they
6072 * type both correctly
6074 * - people who have keys and configuration but occasionally
6075 * need to fall back to passwords
6077 * - people with a key held in Pageant, who might not have
6078 * logged in to a particular machine before; so they want to
6079 * type a username, and then _either_ their key will be
6080 * accepted, _or_ they will type a password. If they mistype
6081 * the username they will want to be able to get back and
6084 s->username[0] = '\0';
6085 s->got_username = FALSE;
6090 if (s->got_username && !ssh->cfg.change_username) {
6092 * We got a username last time round this loop, and
6093 * with change_username turned off we don't try to get
6096 } else if (!*ssh->cfg.username) {
6097 if (ssh_get_line && !ssh_getline_pw_only) {
6098 if (!ssh_get_line("login as: ",
6099 s->username, sizeof(s->username), FALSE)) {
6101 * get_line failed to get a username.
6104 logevent("No username provided. Abandoning session.");
6105 ssh->close_expected = TRUE;
6106 ssh_closing((Plug)ssh, NULL, 0, 0);
6110 int ret; /* need not be saved across crReturn */
6111 c_write_str(ssh, "login as: ");
6113 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
6115 crWaitUntilV(!pktin);
6116 ret = process_userpass_input(ssh, in, inlen);
6120 c_write_str(ssh, "\r\n");
6122 s->username[strcspn(s->username, "\n\r")] = '\0';
6125 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
6126 s->username[sizeof(s->username)-1] = '\0';
6127 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
6128 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
6129 c_write_str(ssh, stuff);
6133 s->got_username = TRUE;
6136 * Send an authentication request using method "none": (a)
6137 * just in case it succeeds, and (b) so that we know what
6138 * authentication methods we can usefully try next.
6140 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6142 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6143 ssh2_pkt_addstring(s->pktout, s->username);
6144 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
6145 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6146 ssh2_pkt_send(ssh, s->pktout);
6147 s->type = AUTH_TYPE_NONE;
6149 s->we_are_in = FALSE;
6151 s->tried_pubkey_config = FALSE;
6152 s->tried_agent = FALSE;
6153 s->kbd_inter_running = FALSE;
6154 s->kbd_inter_refused = FALSE;
6155 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
6156 if (!filename_is_null(ssh->cfg.keyfile)) {
6158 logeventf(ssh, "Reading private key file \"%.150s\"",
6159 filename_to_str(&ssh->cfg.keyfile));
6160 keytype = key_type(&ssh->cfg.keyfile);
6161 if (keytype == SSH_KEYTYPE_SSH2) {
6163 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
6164 &s->publickey_bloblen, NULL);
6167 logeventf(ssh, "Unable to use this key file (%s)",
6168 key_type_to_str(keytype));
6169 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6171 filename_to_str(&ssh->cfg.keyfile),
6172 key_type_to_str(keytype));
6173 c_write_str(ssh, msgbuf);
6175 s->publickey_blob = NULL;
6178 s->publickey_blob = NULL;
6182 * Wait for the result of the last authentication request.
6185 crWaitUntilV(pktin);
6186 while (pktin->type == SSH2_MSG_USERAUTH_BANNER) {
6190 * Don't show the banner if we're operating in
6191 * non-verbose non-interactive mode. (It's probably
6192 * a script, which means nobody will read the
6193 * banner _anyway_, and moreover the printing of
6194 * the banner will screw up processing on the
6195 * output of (say) plink.)
6197 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
6198 ssh_pkt_getstring(pktin, &banner, &size);
6200 c_write_untrusted(ssh, banner, size);
6202 crWaitUntilV(pktin);
6204 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
6205 logevent("Access granted");
6206 s->we_are_in = TRUE;
6210 if (s->kbd_inter_running &&
6211 pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
6213 * This is either a further set-of-prompts packet
6214 * in keyboard-interactive authentication, or it's
6215 * the same one and we came back here with `gotit'
6216 * set. In the former case, we must reset the
6217 * curr_prompt variable.
6221 } else if (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
6222 /* FIXME: perhaps we should support this? */
6223 bombout(("PASSWD_CHANGEREQ not yet supported"));
6225 } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
6226 bombout(("Strange packet received during authentication: type %d",
6234 * OK, we're now sitting on a USERAUTH_FAILURE message, so
6235 * we can look at the string in it and know what we can
6236 * helpfully try next.
6238 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
6241 ssh_pkt_getstring(pktin, &methods, &methlen);
6242 s->kbd_inter_running = FALSE;
6243 if (!ssh2_pkt_getbool(pktin)) {
6245 * We have received an unequivocal Access
6246 * Denied. This can translate to a variety of
6249 * - if we'd just tried "none" authentication,
6250 * it's not worth printing anything at all
6252 * - if we'd just tried a public key _offer_,
6253 * the message should be "Server refused our
6254 * key" (or no message at all if the key
6255 * came from Pageant)
6257 * - if we'd just tried anything else, the
6258 * message really should be "Access denied".
6260 * Additionally, if we'd just tried password
6261 * authentication, we should break out of this
6262 * whole loop so as to go back to the username
6263 * prompt (iff we're configured to allow
6264 * username change attempts).
6266 if (s->type == AUTH_TYPE_NONE) {
6268 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
6269 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
6270 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
6271 c_write_str(ssh, "Server refused our key\r\n");
6272 logevent("Server refused public key");
6273 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
6274 /* server declined keyboard-interactive; ignore */
6276 c_write_str(ssh, "Access denied\r\n");
6277 logevent("Access denied");
6278 if (s->type == AUTH_TYPE_PASSWORD &&
6279 ssh->cfg.change_username) {
6280 /* XXX perhaps we should allow
6281 * keyboard-interactive to do this too? */
6282 s->we_are_in = FALSE;
6287 c_write_str(ssh, "Further authentication required\r\n");
6288 logevent("Further authentication required");
6292 in_commasep_string("publickey", methods, methlen);
6294 in_commasep_string("password", methods, methlen);
6295 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
6296 in_commasep_string("keyboard-interactive", methods, methlen);
6300 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6304 * Most password/passphrase prompts will be
6305 * non-echoing, so we set this to 0 by default.
6306 * Exception is that some keyboard-interactive prompts
6307 * can be echoing, in which case we'll set this to 1.
6311 if (!s->method && s->can_pubkey &&
6312 agent_exists() && !s->tried_agent) {
6314 * Attempt public-key authentication using Pageant.
6319 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6320 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6322 s->tried_agent = TRUE;
6324 logevent("Pageant is running. Requesting keys.");
6326 /* Request the keys held by the agent. */
6327 PUT_32BIT(s->request, 1);
6328 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
6329 if (!agent_query(s->request, 5, &r, &s->responselen,
6330 ssh_agent_callback, ssh)) {
6334 bombout(("Unexpected data from server while"
6335 " waiting for agent response"));
6338 } while (pktin || inlen > 0);
6339 r = ssh->agent_response;
6340 s->responselen = ssh->agent_response_len;
6342 s->response = (unsigned char *) r;
6343 if (s->response && s->responselen >= 5 &&
6344 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
6345 s->p = s->response + 5;
6346 s->nkeys = GET_32BIT(s->p);
6350 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
6353 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
6358 sprintf(buf, "Trying Pageant key #%d", s->keyi);
6361 s->pklen = GET_32BIT(s->p);
6363 if (s->publickey_blob &&
6364 s->pklen == s->publickey_bloblen &&
6365 !memcmp(s->p, s->publickey_blob,
6366 s->publickey_bloblen)) {
6367 logevent("This key matches configured key file");
6368 s->tried_pubkey_config = 1;
6370 s->pkblob = (char *)s->p;
6372 s->alglen = GET_32BIT(s->pkblob);
6373 s->alg = s->pkblob + 4;
6374 s->commentlen = GET_32BIT(s->p);
6376 s->commentp = (char *)s->p;
6377 s->p += s->commentlen;
6378 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6379 ssh2_pkt_addstring(s->pktout, s->username);
6380 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6381 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6382 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6383 ssh2_pkt_addstring_start(s->pktout);
6384 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6385 ssh2_pkt_addstring_start(s->pktout);
6386 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6387 ssh2_pkt_send(ssh, s->pktout);
6389 crWaitUntilV(pktin);
6390 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6391 logevent("Key refused");
6395 if (flags & FLAG_VERBOSE) {
6396 c_write_str(ssh, "Authenticating with "
6398 c_write(ssh, s->commentp, s->commentlen);
6399 c_write_str(ssh, "\" from agent\r\n");
6403 * Server is willing to accept the key.
6404 * Construct a SIGN_REQUEST.
6406 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6407 ssh2_pkt_addstring(s->pktout, s->username);
6408 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6409 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6410 ssh2_pkt_addbool(s->pktout, TRUE);
6411 ssh2_pkt_addstring_start(s->pktout);
6412 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6413 ssh2_pkt_addstring_start(s->pktout);
6414 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6416 s->siglen = s->pktout->length - 5 + 4 + 20;
6417 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6419 s->len = 1; /* message type */
6420 s->len += 4 + s->pklen; /* key blob */
6421 s->len += 4 + s->siglen; /* data to sign */
6422 s->len += 4; /* flags */
6423 s->agentreq = snewn(4 + s->len, char);
6424 PUT_32BIT(s->agentreq, s->len);
6425 s->q = s->agentreq + 4;
6426 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
6427 PUT_32BIT(s->q, s->pklen);
6429 memcpy(s->q, s->pkblob, s->pklen);
6431 PUT_32BIT(s->q, s->siglen);
6433 /* Now the data to be signed... */
6434 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6435 PUT_32BIT(s->q, 20);
6438 memcpy(s->q, ssh->v2_session_id, 20);
6440 memcpy(s->q, s->pktout->data + 5,
6441 s->pktout->length - 5);
6442 s->q += s->pktout->length - 5;
6443 /* And finally the (zero) flags word. */
6445 if (!agent_query(s->agentreq, s->len + 4,
6447 ssh_agent_callback, ssh)) {
6451 bombout(("Unexpected data from server"
6452 " while waiting for agent"
6456 } while (pktin || inlen > 0);
6457 vret = ssh->agent_response;
6458 s->retlen = ssh->agent_response_len;
6463 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
6464 logevent("Sending Pageant's response");
6465 ssh2_add_sigblob(ssh, s->pktout,
6466 s->pkblob, s->pklen,
6468 GET_32BIT(s->ret + 5));
6469 ssh2_pkt_send(ssh, s->pktout);
6474 ("Pageant failed to answer challenge");
6485 if (!s->method && s->can_pubkey && s->publickey_blob
6486 && !s->tried_pubkey_config) {
6487 unsigned char *pub_blob;
6488 char *algorithm, *comment;
6491 s->tried_pubkey_config = TRUE;
6493 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6494 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6497 * Try the public key supplied in the configuration.
6499 * First, offer the public blob to see if the server is
6500 * willing to accept it.
6503 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
6508 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6509 ssh2_pkt_addstring(s->pktout, s->username);
6510 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6511 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6512 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6513 ssh2_pkt_addstring(s->pktout, algorithm);
6514 ssh2_pkt_addstring_start(s->pktout);
6515 ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob,
6517 ssh2_pkt_send(ssh, s->pktout);
6518 logevent("Offered public key");
6520 crWaitUntilV(pktin);
6521 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6523 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
6524 continue; /* key refused; give up on it */
6527 logevent("Offer of public key accepted");
6529 * Actually attempt a serious authentication using
6532 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
6533 sprintf(s->pwprompt,
6534 "Passphrase for key \"%.100s\": ",
6540 if (flags & FLAG_VERBOSE) {
6541 c_write_str(ssh, "Authenticating with public key \"");
6542 c_write_str(ssh, comment);
6543 c_write_str(ssh, "\"\r\n");
6545 s->method = AUTH_PUBLICKEY_FILE;
6549 if (!s->method && s->can_keyb_inter && !s->kbd_inter_refused &&
6550 !s->kbd_inter_running) {
6551 s->method = AUTH_KEYBOARD_INTERACTIVE;
6552 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6554 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6555 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
6557 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6558 ssh2_pkt_addstring(s->pktout, s->username);
6559 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6560 ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); /* method */
6561 ssh2_pkt_addstring(s->pktout, ""); /* lang */
6562 ssh2_pkt_addstring(s->pktout, "");
6563 ssh2_pkt_send(ssh, s->pktout);
6565 crWaitUntilV(pktin);
6566 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
6567 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
6569 logevent("Keyboard-interactive authentication refused");
6570 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
6571 s->kbd_inter_refused = TRUE; /* don't try it again */
6575 s->kbd_inter_running = TRUE;
6579 if (s->kbd_inter_running) {
6580 s->method = AUTH_KEYBOARD_INTERACTIVE;
6581 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6583 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6584 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
6586 if (s->curr_prompt == 0) {
6588 * We've got a fresh USERAUTH_INFO_REQUEST.
6589 * Display header data, and start going through
6592 char *name, *inst, *lang;
6593 int name_len, inst_len, lang_len;
6595 ssh_pkt_getstring(pktin, &name, &name_len);
6596 ssh_pkt_getstring(pktin, &inst, &inst_len);
6597 ssh_pkt_getstring(pktin, &lang, &lang_len);
6599 c_write_untrusted(ssh, name, name_len);
6600 c_write_str(ssh, "\r\n");
6603 c_write_untrusted(ssh, inst, inst_len);
6604 c_write_str(ssh, "\r\n");
6606 s->num_prompts = ssh_pkt_getuint32(pktin);
6610 * If there are prompts remaining in the packet,
6611 * display one and get a response.
6613 if (s->curr_prompt < s->num_prompts) {
6617 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
6618 if (prompt_len > 0) {
6619 static const char trunc[] = "<prompt truncated>: ";
6620 static const int prlen = sizeof(s->pwprompt) -
6622 if (prompt_len > prlen) {
6623 memcpy(s->pwprompt, prompt, prlen);
6624 strcpy(s->pwprompt + prlen, trunc);
6626 memcpy(s->pwprompt, prompt, prompt_len);
6627 s->pwprompt[prompt_len] = '\0';
6631 "<server failed to send prompt>: ");
6633 s->echo = ssh2_pkt_getbool(pktin);
6639 if (!s->method && s->can_passwd) {
6640 s->method = AUTH_PASSWORD;
6641 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6642 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
6643 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
6650 if (!ssh_get_line(s->pwprompt, s->password,
6651 sizeof(s->password), TRUE)) {
6653 * get_line failed to get a password (for
6654 * example because one was supplied on the
6655 * command line which has already failed to
6658 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6659 ssh2_pkt_adduint32(s->pktout,SSH2_DISCONNECT_BY_APPLICATION);
6660 ssh2_pkt_addstring(s->pktout, "No more passwords available"
6662 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
6663 ssh2_pkt_send_noqueue(ssh, s->pktout);
6664 logevent("Unable to authenticate");
6665 connection_fatal(ssh->frontend,
6666 "Unable to authenticate");
6667 ssh->close_expected = TRUE;
6668 ssh_closing((Plug)ssh, NULL, 0, 0);
6672 int ret; /* need not be saved across crReturn */
6673 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
6676 setup_userpass_input(ssh, s->password,
6677 sizeof(s->password), s->echo);
6679 crWaitUntilV(!pktin);
6680 ret = process_userpass_input(ssh, in, inlen);
6684 c_write_str(ssh, "\r\n");
6688 if (s->method == AUTH_PUBLICKEY_FILE) {
6690 * We have our passphrase. Now try the actual authentication.
6692 struct ssh2_userkey *key;
6693 const char *error = NULL;
6695 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
6697 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
6698 if (key == SSH2_WRONG_PASSPHRASE) {
6699 c_write_str(ssh, "Wrong passphrase\r\n");
6700 s->tried_pubkey_config = FALSE;
6702 c_write_str(ssh, "Unable to load private key (");
6703 c_write_str(ssh, error);
6704 c_write_str(ssh, ")\r\n");
6705 s->tried_pubkey_config = TRUE;
6707 /* Send a spurious AUTH_NONE to return to the top. */
6708 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6709 ssh2_pkt_addstring(s->pktout, s->username);
6710 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6711 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6712 ssh2_pkt_send(ssh, s->pktout);
6713 s->type = AUTH_TYPE_NONE;
6715 unsigned char *pkblob, *sigblob, *sigdata;
6716 int pkblob_len, sigblob_len, sigdata_len;
6720 * We have loaded the private key and the server
6721 * has announced that it's willing to accept it.
6722 * Hallelujah. Generate a signature and send it.
6724 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6725 ssh2_pkt_addstring(s->pktout, s->username);
6726 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6727 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6728 ssh2_pkt_addbool(s->pktout, TRUE);
6729 ssh2_pkt_addstring(s->pktout, key->alg->name);
6730 pkblob = key->alg->public_blob(key->data, &pkblob_len);
6731 ssh2_pkt_addstring_start(s->pktout);
6732 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len);
6735 * The data to be signed is:
6739 * followed by everything so far placed in the
6742 sigdata_len = s->pktout->length - 5 + 4 + 20;
6743 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6745 sigdata = snewn(sigdata_len, unsigned char);
6747 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6748 PUT_32BIT(sigdata+p, 20);
6751 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
6752 memcpy(sigdata+p, s->pktout->data + 5,
6753 s->pktout->length - 5);
6754 p += s->pktout->length - 5;
6755 assert(p == sigdata_len);
6756 sigblob = key->alg->sign(key->data, (char *)sigdata,
6757 sigdata_len, &sigblob_len);
6758 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
6759 sigblob, sigblob_len);
6764 ssh2_pkt_send(ssh, s->pktout);
6765 s->type = AUTH_TYPE_PUBLICKEY;
6766 key->alg->freekey(key->data);
6768 } else if (s->method == AUTH_PASSWORD) {
6770 * We pad out the password packet to 256 bytes to make
6771 * it harder for an attacker to find the length of the
6774 * Anyone using a password longer than 256 bytes
6775 * probably doesn't have much to worry about from
6776 * people who find out how long their password is!
6778 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6779 s->pktout->forcepad = 256;
6780 ssh2_pkt_addstring(s->pktout, s->username);
6781 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6782 ssh2_pkt_addstring(s->pktout, "password");
6783 ssh2_pkt_addbool(s->pktout, FALSE);
6784 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6785 ssh2_pkt_addstring(s->pktout, s->password);
6786 memset(s->password, 0, sizeof(s->password));
6787 end_log_omission(ssh, s->pktout);
6788 ssh2_pkt_send(ssh, s->pktout);
6789 logevent("Sent password");
6790 s->type = AUTH_TYPE_PASSWORD;
6791 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
6792 if (s->curr_prompt == 0) {
6793 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
6794 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
6796 if (s->need_pw) { /* only add pw if we just got one! */
6797 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6798 ssh2_pkt_addstring(s->pktout, s->password);
6799 memset(s->password, 0, sizeof(s->password));
6800 end_log_omission(ssh, s->pktout);
6803 if (s->curr_prompt >= s->num_prompts) {
6804 ssh2_pkt_send(ssh, s->pktout);
6807 * If there are prompts remaining, we set
6808 * `gotit' so that we won't attempt to get
6809 * another packet. Then we go back round the
6810 * loop and will end up retrieving another
6811 * prompt out of the existing packet. Funky or
6816 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6818 c_write_str(ssh, "No supported authentication methods"
6819 " left to try!\r\n");
6820 logevent("No supported authentications offered."
6822 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6823 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
6824 ssh2_pkt_addstring(s->pktout, "No supported authentication"
6825 " methods available");
6826 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
6827 ssh2_pkt_send_noqueue(ssh, s->pktout);
6828 ssh->close_expected = TRUE;
6829 ssh_closing((Plug)ssh, NULL, 0, 0);
6833 } while (!s->we_are_in);
6836 * Now we're authenticated for the connection protocol. The
6837 * connection protocol will automatically have started at this
6838 * point; there's no need to send SERVICE_REQUEST.
6841 ssh->channels = newtree234(ssh_channelcmp);
6844 * Set up handlers for some connection protocol messages, so we
6845 * don't have to handle them repeatedly in this coroutine.
6847 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
6848 ssh2_msg_channel_window_adjust;
6849 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
6850 ssh2_msg_global_request;
6853 * Create the main session channel.
6855 if (!ssh->cfg.ssh_no_shell) {
6856 ssh->mainchan = snew(struct ssh_channel);
6857 ssh->mainchan->ssh = ssh;
6858 ssh->mainchan->localid = alloc_channel_id(ssh);
6859 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
6860 ssh2_pkt_addstring(s->pktout, "session");
6861 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
6862 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
6863 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
6864 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
6865 ssh2_pkt_send(ssh, s->pktout);
6866 crWaitUntilV(pktin);
6867 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
6868 bombout(("Server refused to open a session"));
6870 /* FIXME: error data comes back in FAILURE packet */
6872 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
6873 bombout(("Server's channel confirmation cited wrong channel"));
6876 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
6877 ssh->mainchan->type = CHAN_MAINSESSION;
6878 ssh->mainchan->closes = 0;
6879 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6880 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
6881 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
6882 add234(ssh->channels, ssh->mainchan);
6883 update_specials_menu(ssh->frontend);
6884 logevent("Opened channel for session");
6886 ssh->mainchan = NULL;
6889 * Now we have a channel, make dispatch table entries for
6890 * general channel-based messages.
6892 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
6893 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
6894 ssh2_msg_channel_data;
6895 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
6896 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
6897 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
6898 ssh2_msg_channel_open_confirmation;
6899 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
6900 ssh2_msg_channel_open_failure;
6901 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
6902 ssh2_msg_channel_request;
6903 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
6904 ssh2_msg_channel_open;
6907 * Potentially enable X11 forwarding.
6909 if (ssh->mainchan && ssh->cfg.x11_forward) {
6910 char proto[20], data[64];
6911 logevent("Requesting X11 forwarding");
6912 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
6913 data, sizeof(data), ssh->cfg.x11_auth);
6914 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
6915 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6916 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6917 ssh2_pkt_addstring(s->pktout, "x11-req");
6918 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6919 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
6920 ssh2_pkt_addstring(s->pktout, proto);
6921 ssh2_pkt_addstring(s->pktout, data);
6922 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
6923 ssh2_pkt_send(ssh, s->pktout);
6925 crWaitUntilV(pktin);
6927 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6928 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6929 bombout(("Unexpected response to X11 forwarding request:"
6930 " packet type %d", pktin->type));
6933 logevent("X11 forwarding refused");
6935 logevent("X11 forwarding enabled");
6936 ssh->X11_fwd_enabled = TRUE;
6941 * Enable port forwardings.
6943 ssh_setup_portfwd(ssh, &ssh->cfg);
6946 * Potentially enable agent forwarding.
6948 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
6949 logevent("Requesting OpenSSH-style agent forwarding");
6950 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6951 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6952 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
6953 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6954 ssh2_pkt_send(ssh, s->pktout);
6956 crWaitUntilV(pktin);
6958 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6959 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6960 bombout(("Unexpected response to agent forwarding request:"
6961 " packet type %d", pktin->type));
6964 logevent("Agent forwarding refused");
6966 logevent("Agent forwarding enabled");
6967 ssh->agentfwd_enabled = TRUE;
6972 * Now allocate a pty for the session.
6974 if (ssh->mainchan && !ssh->cfg.nopty) {
6975 /* Unpick the terminal-speed string. */
6976 /* XXX perhaps we should allow no speeds to be sent. */
6977 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
6978 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
6979 /* Build the pty request. */
6980 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6981 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
6982 ssh2_pkt_addstring(s->pktout, "pty-req");
6983 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6984 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
6985 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
6986 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
6987 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
6988 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
6989 ssh2_pkt_addstring_start(s->pktout);
6990 ssh2_pkt_addbyte(s->pktout, 128); /* TTY_OP_ISPEED */
6991 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
6992 ssh2_pkt_addbyte(s->pktout, 129); /* TTY_OP_OSPEED */
6993 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
6994 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
6995 ssh2_pkt_send(ssh, s->pktout);
6996 ssh->state = SSH_STATE_INTERMED;
6998 crWaitUntilV(pktin);
7000 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7001 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7002 bombout(("Unexpected response to pty request:"
7003 " packet type %d", pktin->type));
7006 c_write_str(ssh, "Server refused to allocate pty\r\n");
7007 ssh->editing = ssh->echoing = 1;
7009 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
7010 ssh->ospeed, ssh->ispeed);
7013 ssh->editing = ssh->echoing = 1;
7017 * Send environment variables.
7019 * Simplest thing here is to send all the requests at once, and
7020 * then wait for a whole bunch of successes or failures.
7022 if (ssh->mainchan && *ssh->cfg.environmt) {
7023 char *e = ssh->cfg.environmt;
7024 char *var, *varend, *val;
7030 while (*e && *e != '\t') e++;
7032 if (*e == '\t') e++;
7037 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7038 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7039 ssh2_pkt_addstring(s->pktout, "env");
7040 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7041 ssh2_pkt_addstring_start(s->pktout);
7042 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
7043 ssh2_pkt_addstring(s->pktout, val);
7044 ssh2_pkt_send(ssh, s->pktout);
7049 logeventf(ssh, "Sent %d environment variables", s->num_env);
7052 s->env_left = s->num_env;
7054 while (s->env_left > 0) {
7055 crWaitUntilV(pktin);
7057 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7058 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7059 bombout(("Unexpected response to environment request:"
7060 " packet type %d", pktin->type));
7070 if (s->env_ok == s->num_env) {
7071 logevent("All environment variables successfully set");
7072 } else if (s->env_ok == 0) {
7073 logevent("All environment variables refused");
7074 c_write_str(ssh, "Server refused to set environment variables\r\n");
7076 logeventf(ssh, "%d environment variables refused",
7077 s->num_env - s->env_ok);
7078 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7083 * Start a shell or a remote command. We may have to attempt
7084 * this twice if the config data has provided a second choice
7087 if (ssh->mainchan) while (1) {
7091 if (ssh->fallback_cmd) {
7092 subsys = ssh->cfg.ssh_subsys2;
7093 cmd = ssh->cfg.remote_cmd_ptr2;
7095 subsys = ssh->cfg.ssh_subsys;
7096 cmd = ssh->cfg.remote_cmd_ptr;
7099 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7100 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
7102 ssh2_pkt_addstring(s->pktout, "subsystem");
7103 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7104 ssh2_pkt_addstring(s->pktout, cmd);
7106 ssh2_pkt_addstring(s->pktout, "exec");
7107 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7108 ssh2_pkt_addstring(s->pktout, cmd);
7110 ssh2_pkt_addstring(s->pktout, "shell");
7111 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7113 ssh2_pkt_send(ssh, s->pktout);
7115 crWaitUntilV(pktin);
7117 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7118 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7119 bombout(("Unexpected response to shell/command request:"
7120 " packet type %d", pktin->type));
7124 * We failed to start the command. If this is the
7125 * fallback command, we really are finished; if it's
7126 * not, and if the fallback command exists, try falling
7127 * back to it before complaining.
7129 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
7130 logevent("Primary command failed; attempting fallback");
7131 ssh->fallback_cmd = TRUE;
7134 bombout(("Server refused to start a shell/command"));
7137 logevent("Started a shell/command");
7142 ssh->state = SSH_STATE_SESSION;
7143 if (ssh->size_needed)
7144 ssh_size(ssh, ssh->term_width, ssh->term_height);
7145 if (ssh->eof_needed)
7146 ssh_special(ssh, TS_EOF);
7152 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
7157 s->try_send = FALSE;
7161 * _All_ the connection-layer packets we expect to
7162 * receive are now handled by the dispatch table.
7163 * Anything that reaches here must be bogus.
7166 bombout(("Strange packet received: type %d", pktin->type));
7168 } else if (ssh->mainchan) {
7170 * We have spare data. Add it to the channel buffer.
7172 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
7177 struct ssh_channel *c;
7179 * Try to send data on all channels if we can.
7181 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
7184 continue; /* don't send on closing channels */
7185 bufsize = ssh2_try_send(c);
7188 case CHAN_MAINSESSION:
7189 /* stdin need not receive an unthrottle
7190 * notification since it will be polled */
7193 x11_unthrottle(c->u.x11.s);
7196 /* agent sockets are request/response and need no
7197 * buffer management */
7200 pfd_unthrottle(c->u.pfd.s);
7212 * Handlers for SSH2 messages that might arrive at any moment.
7214 void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
7216 /* log reason code in disconnect message */
7218 int nowlen, reason, msglen;
7220 reason = ssh_pkt_getuint32(pktin);
7221 ssh_pkt_getstring(pktin, &msg, &msglen);
7223 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
7224 buf = dupprintf("Received disconnect message (%s)",
7225 ssh2_disconnect_reasons[reason]);
7227 buf = dupprintf("Received disconnect message (unknown"
7228 " type %d)", reason);
7232 buf = dupprintf("Disconnection message text: %n%.*s",
7233 &nowlen, msglen, msg);
7235 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
7237 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
7238 ssh2_disconnect_reasons[reason] : "unknown",
7243 void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
7245 /* log the debug message */
7250 /* XXX maybe we should actually take notice of this */
7251 always_display = ssh2_pkt_getbool(pktin);
7252 ssh_pkt_getstring(pktin, &msg, &msglen);
7254 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
7259 void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
7261 struct Packet *pktout;
7262 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
7263 ssh2_pkt_adduint32(pktout, pktin->sequence);
7265 * UNIMPLEMENTED messages MUST appear in the same order as the
7266 * messages they respond to. Hence, never queue them.
7268 ssh2_pkt_send_noqueue(ssh, pktout);
7272 * Handle the top-level SSH2 protocol.
7274 static void ssh2_protocol_setup(Ssh ssh)
7279 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
7281 for (i = 0; i < 256; i++)
7282 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
7285 * Any message we actually understand, we set to NULL so that
7286 * the coroutines will get it.
7288 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
7289 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
7290 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
7291 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
7292 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
7293 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
7294 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
7295 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
7296 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
7297 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
7298 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
7299 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
7300 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
7301 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
7302 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7303 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
7304 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
7305 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
7306 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
7307 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
7308 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
7309 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
7310 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
7311 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
7312 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
7313 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
7314 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
7315 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
7316 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
7317 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
7318 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
7319 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
7320 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
7323 * These special message types we install handlers for.
7325 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
7326 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with ssh1 */
7327 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
7330 static void ssh2_timer(void *ctx, long now)
7334 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
7335 now - ssh->next_rekey >= 0) {
7336 do_ssh2_transport(ssh, "timeout", -1, NULL);
7340 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
7341 struct Packet *pktin)
7343 unsigned char *in = (unsigned char *)vin;
7344 if (ssh->state == SSH_STATE_CLOSED)
7348 ssh->incoming_data_size += pktin->encrypted_len;
7349 if (!ssh->kex_in_progress &&
7350 ssh->max_data_size != 0 &&
7351 ssh->incoming_data_size > ssh->max_data_size)
7352 do_ssh2_transport(ssh, "too much data received", -1, NULL);
7355 if (pktin && ssh->packet_dispatch[pktin->type]) {
7356 ssh->packet_dispatch[pktin->type](ssh, pktin);
7360 if (!ssh->protocol_initial_phase_done ||
7361 (pktin && pktin->type >= 20 && pktin->type < 50)) {
7362 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
7363 !ssh->protocol_initial_phase_done) {
7364 ssh->protocol_initial_phase_done = TRUE;
7366 * Allow authconn to initialise itself.
7368 do_ssh2_authconn(ssh, NULL, 0, NULL);
7371 do_ssh2_authconn(ssh, in, inlen, pktin);
7376 * Called to set up the connection.
7378 * Returns an error message, or NULL on success.
7380 static const char *ssh_init(void *frontend_handle, void **backend_handle,
7382 char *host, int port, char **realhost, int nodelay,
7388 ssh = snew(struct ssh_tag);
7389 ssh->cfg = *cfg; /* STRUCTURE COPY */
7390 ssh->version = 0; /* when not ready yet */
7393 ssh->v1_cipher_ctx = NULL;
7394 ssh->crcda_ctx = NULL;
7395 ssh->cscipher = NULL;
7396 ssh->cs_cipher_ctx = NULL;
7397 ssh->sccipher = NULL;
7398 ssh->sc_cipher_ctx = NULL;
7400 ssh->cs_mac_ctx = NULL;
7402 ssh->sc_mac_ctx = NULL;
7404 ssh->cs_comp_ctx = NULL;
7406 ssh->sc_comp_ctx = NULL;
7408 ssh->kex_ctx = NULL;
7409 ssh->hostkey = NULL;
7411 ssh->close_expected = FALSE;
7412 ssh->state = SSH_STATE_PREPACKET;
7413 ssh->size_needed = FALSE;
7414 ssh->eof_needed = FALSE;
7417 ssh->deferred_send_data = NULL;
7418 ssh->deferred_len = 0;
7419 ssh->deferred_size = 0;
7420 ssh->fallback_cmd = 0;
7422 ssh->x11auth = NULL;
7423 ssh->v1_compressing = FALSE;
7424 ssh->v2_outgoing_sequence = 0;
7425 ssh->ssh1_rdpkt_crstate = 0;
7426 ssh->ssh2_rdpkt_crstate = 0;
7427 ssh->do_ssh_init_crstate = 0;
7428 ssh->ssh_gotdata_crstate = 0;
7429 ssh->do_ssh1_connection_crstate = 0;
7430 ssh->do_ssh1_login_crstate = 0;
7431 ssh->do_ssh2_transport_crstate = 0;
7432 ssh->do_ssh2_authconn_crstate = 0;
7433 ssh->do_ssh_init_state = NULL;
7434 ssh->do_ssh1_login_state = NULL;
7435 ssh->do_ssh2_transport_state = NULL;
7436 ssh->do_ssh2_authconn_state = NULL;
7437 ssh->mainchan = NULL;
7438 ssh->throttled_all = 0;
7439 ssh->v1_stdout_throttling = 0;
7441 ssh->queuelen = ssh->queuesize = 0;
7442 ssh->queueing = FALSE;
7443 ssh->qhead = ssh->qtail = NULL;
7444 ssh->deferred_rekey_reason = NULL;
7446 *backend_handle = ssh;
7449 if (crypto_startup() == 0)
7450 return "Microsoft high encryption pack not installed!";
7453 ssh->frontend = frontend_handle;
7454 ssh->term_width = ssh->cfg.width;
7455 ssh->term_height = ssh->cfg.height;
7457 ssh->channels = NULL;
7458 ssh->rportfwds = NULL;
7459 ssh->portfwds = NULL;
7464 ssh->v1_throttle_count = 0;
7465 ssh->overall_bufsize = 0;
7466 ssh->fallback_cmd = 0;
7468 ssh->protocol = NULL;
7470 ssh->protocol_initial_phase_done = FALSE;
7474 ssh->incoming_data_size = ssh->outgoing_data_size =
7475 ssh->deferred_data_size = 0L;
7476 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
7477 ssh->kex_in_progress = FALSE;
7479 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
7488 static void ssh_free(void *handle)
7490 Ssh ssh = (Ssh) handle;
7491 struct ssh_channel *c;
7492 struct ssh_rportfwd *pf;
7494 if (ssh->v1_cipher_ctx)
7495 ssh->cipher->free_context(ssh->v1_cipher_ctx);
7496 if (ssh->cs_cipher_ctx)
7497 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7498 if (ssh->sc_cipher_ctx)
7499 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7500 if (ssh->cs_mac_ctx)
7501 ssh->csmac->free_context(ssh->cs_mac_ctx);
7502 if (ssh->sc_mac_ctx)
7503 ssh->scmac->free_context(ssh->sc_mac_ctx);
7504 if (ssh->cs_comp_ctx) {
7506 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7508 zlib_compress_cleanup(ssh->cs_comp_ctx);
7510 if (ssh->sc_comp_ctx) {
7512 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7514 zlib_decompress_cleanup(ssh->sc_comp_ctx);
7517 dh_cleanup(ssh->kex_ctx);
7518 sfree(ssh->savedhost);
7520 while (ssh->queuelen-- > 0)
7521 ssh_free_packet(ssh->queue[ssh->queuelen]);
7524 while (ssh->qhead) {
7525 struct queued_handler *qh = ssh->qhead;
7526 ssh->qhead = qh->next;
7529 ssh->qhead = ssh->qtail = NULL;
7531 if (ssh->channels) {
7532 while ((c = delpos234(ssh->channels, 0)) != NULL) {
7535 if (c->u.x11.s != NULL)
7536 x11_close(c->u.x11.s);
7539 if (c->u.pfd.s != NULL)
7540 pfd_close(c->u.pfd.s);
7545 freetree234(ssh->channels);
7546 ssh->channels = NULL;
7549 if (ssh->rportfwds) {
7550 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
7552 freetree234(ssh->rportfwds);
7553 ssh->rportfwds = NULL;
7555 sfree(ssh->deferred_send_data);
7557 x11_free_auth(ssh->x11auth);
7558 sfree(ssh->do_ssh_init_state);
7559 sfree(ssh->do_ssh1_login_state);
7560 sfree(ssh->do_ssh2_transport_state);
7561 sfree(ssh->do_ssh2_authconn_state);
7562 if (ssh->crcda_ctx) {
7563 crcda_free_context(ssh->crcda_ctx);
7564 ssh->crcda_ctx = NULL;
7567 ssh_do_close(ssh, TRUE);
7568 expire_timer_context(ssh);
7570 pinger_free(ssh->pinger);
7577 * Reconfigure the SSH backend.
7579 static void ssh_reconfig(void *handle, Config *cfg)
7581 Ssh ssh = (Ssh) handle;
7582 char *rekeying = NULL, rekey_mandatory = FALSE;
7583 unsigned long old_max_data_size;
7585 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
7586 ssh_setup_portfwd(ssh, cfg);
7588 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
7589 cfg->ssh_rekey_time != 0) {
7590 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
7591 long now = GETTICKCOUNT();
7593 if (new_next - now < 0) {
7594 rekeying = "timeout shortened";
7596 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
7600 old_max_data_size = ssh->max_data_size;
7601 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
7602 if (old_max_data_size != ssh->max_data_size &&
7603 ssh->max_data_size != 0) {
7604 if (ssh->outgoing_data_size > ssh->max_data_size ||
7605 ssh->incoming_data_size > ssh->max_data_size)
7606 rekeying = "data limit lowered";
7609 if (ssh->cfg.compression != cfg->compression) {
7610 rekeying = "compression setting changed";
7611 rekey_mandatory = TRUE;
7614 if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
7615 memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
7616 sizeof(ssh->cfg.ssh_cipherlist))) {
7617 rekeying = "cipher settings changed";
7618 rekey_mandatory = TRUE;
7621 ssh->cfg = *cfg; /* STRUCTURE COPY */
7624 if (!ssh->kex_in_progress) {
7625 do_ssh2_transport(ssh, rekeying, -1, NULL);
7626 } else if (rekey_mandatory) {
7627 ssh->deferred_rekey_reason = rekeying;
7633 * Called to send data down the Telnet connection.
7635 static int ssh_send(void *handle, char *buf, int len)
7637 Ssh ssh = (Ssh) handle;
7639 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
7642 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
7644 return ssh_sendbuffer(ssh);
7648 * Called to query the current amount of buffered stdin data.
7650 static int ssh_sendbuffer(void *handle)
7652 Ssh ssh = (Ssh) handle;
7655 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
7659 * If the SSH socket itself has backed up, add the total backup
7660 * size on that to any individual buffer on the stdin channel.
7663 if (ssh->throttled_all)
7664 override_value = ssh->overall_bufsize;
7666 if (ssh->version == 1) {
7667 return override_value;
7668 } else if (ssh->version == 2) {
7669 if (!ssh->mainchan || ssh->mainchan->closes > 0)
7670 return override_value;
7672 return (override_value +
7673 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
7680 * Called to set the size of the window from SSH's POV.
7682 static void ssh_size(void *handle, int width, int height)
7684 Ssh ssh = (Ssh) handle;
7685 struct Packet *pktout;
7687 ssh->term_width = width;
7688 ssh->term_height = height;
7690 switch (ssh->state) {
7691 case SSH_STATE_BEFORE_SIZE:
7692 case SSH_STATE_PREPACKET:
7693 case SSH_STATE_CLOSED:
7694 break; /* do nothing */
7695 case SSH_STATE_INTERMED:
7696 ssh->size_needed = TRUE; /* buffer for later */
7698 case SSH_STATE_SESSION:
7699 if (!ssh->cfg.nopty) {
7700 if (ssh->version == 1) {
7701 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
7702 PKT_INT, ssh->term_height,
7703 PKT_INT, ssh->term_width,
7704 PKT_INT, 0, PKT_INT, 0, PKT_END);
7705 } else if (ssh->mainchan) {
7706 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7707 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7708 ssh2_pkt_addstring(pktout, "window-change");
7709 ssh2_pkt_addbool(pktout, 0);
7710 ssh2_pkt_adduint32(pktout, ssh->term_width);
7711 ssh2_pkt_adduint32(pktout, ssh->term_height);
7712 ssh2_pkt_adduint32(pktout, 0);
7713 ssh2_pkt_adduint32(pktout, 0);
7714 ssh2_pkt_send(ssh, pktout);
7722 * Return a list of the special codes that make sense in this
7725 static const struct telnet_special *ssh_get_specials(void *handle)
7727 static const struct telnet_special ssh1_ignore_special[] = {
7728 {"IGNORE message", TS_NOP}
7730 static const struct telnet_special ssh2_transport_specials[] = {
7731 {"IGNORE message", TS_NOP},
7732 {"Repeat key exchange", TS_REKEY},
7734 static const struct telnet_special ssh2_session_specials[] = {
7737 /* These are the signal names defined by draft-ietf-secsh-connect-23.
7738 * They include all the ISO C signals, but are a subset of the POSIX
7739 * required signals. */
7740 {"SIGINT (Interrupt)", TS_SIGINT},
7741 {"SIGTERM (Terminate)", TS_SIGTERM},
7742 {"SIGKILL (Kill)", TS_SIGKILL},
7743 {"SIGQUIT (Quit)", TS_SIGQUIT},
7744 {"SIGHUP (Hangup)", TS_SIGHUP},
7745 {"More signals", TS_SUBMENU},
7746 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
7747 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
7748 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
7749 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
7752 static const struct telnet_special specials_end[] = {
7755 /* XXX review this length for any changes: */
7756 static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
7757 lenof(ssh2_session_specials) +
7758 lenof(specials_end)];
7759 Ssh ssh = (Ssh) handle;
7761 #define ADD_SPECIALS(name) \
7763 assert((i + lenof(name)) <= lenof(ssh_specials)); \
7764 memcpy(&ssh_specials[i], name, sizeof name); \
7768 if (ssh->version == 1) {
7769 /* Don't bother offering IGNORE if we've decided the remote
7770 * won't cope with it, since we wouldn't bother sending it if
7772 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7773 ADD_SPECIALS(ssh1_ignore_special);
7774 } else if (ssh->version == 2) {
7775 ADD_SPECIALS(ssh2_transport_specials);
7777 ADD_SPECIALS(ssh2_session_specials);
7778 } /* else we're not ready yet */
7781 ADD_SPECIALS(specials_end);
7782 return ssh_specials;
7790 * Send Telnet special codes. TS_EOF is useful for `plink', so you
7791 * can send an EOF and collect resulting output (e.g. `plink
7794 static void ssh_special(void *handle, Telnet_Special code)
7796 Ssh ssh = (Ssh) handle;
7797 struct Packet *pktout;
7799 if (code == TS_EOF) {
7800 if (ssh->state != SSH_STATE_SESSION) {
7802 * Buffer the EOF in case we are pre-SESSION, so we can
7803 * send it as soon as we reach SESSION.
7806 ssh->eof_needed = TRUE;
7809 if (ssh->version == 1) {
7810 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
7811 } else if (ssh->mainchan) {
7812 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
7813 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7814 ssh2_pkt_send(ssh, pktout);
7816 logevent("Sent EOF message");
7817 } else if (code == TS_PING || code == TS_NOP) {
7818 if (ssh->state == SSH_STATE_CLOSED
7819 || ssh->state == SSH_STATE_PREPACKET) return;
7820 if (ssh->version == 1) {
7821 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7822 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
7824 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
7825 ssh2_pkt_addstring_start(pktout);
7826 ssh2_pkt_send_noqueue(ssh, pktout);
7828 } else if (code == TS_REKEY) {
7829 if (!ssh->kex_in_progress && ssh->version == 2) {
7830 do_ssh2_transport(ssh, "at user request", -1, NULL);
7832 } else if (code == TS_BRK) {
7833 if (ssh->state == SSH_STATE_CLOSED
7834 || ssh->state == SSH_STATE_PREPACKET) return;
7835 if (ssh->version == 1) {
7836 logevent("Unable to send BREAK signal in SSH1");
7837 } else if (ssh->mainchan) {
7838 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7839 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7840 ssh2_pkt_addstring(pktout, "break");
7841 ssh2_pkt_addbool(pktout, 0);
7842 ssh2_pkt_adduint32(pktout, 0); /* default break length */
7843 ssh2_pkt_send(ssh, pktout);
7846 /* Is is a POSIX signal? */
7847 char *signame = NULL;
7848 if (code == TS_SIGABRT) signame = "ABRT";
7849 if (code == TS_SIGALRM) signame = "ALRM";
7850 if (code == TS_SIGFPE) signame = "FPE";
7851 if (code == TS_SIGHUP) signame = "HUP";
7852 if (code == TS_SIGILL) signame = "ILL";
7853 if (code == TS_SIGINT) signame = "INT";
7854 if (code == TS_SIGKILL) signame = "KILL";
7855 if (code == TS_SIGPIPE) signame = "PIPE";
7856 if (code == TS_SIGQUIT) signame = "QUIT";
7857 if (code == TS_SIGSEGV) signame = "SEGV";
7858 if (code == TS_SIGTERM) signame = "TERM";
7859 if (code == TS_SIGUSR1) signame = "USR1";
7860 if (code == TS_SIGUSR2) signame = "USR2";
7861 /* The SSH-2 protocol does in principle support arbitrary named
7862 * signals, including signame@domain, but we don't support those. */
7864 /* It's a signal. */
7865 if (ssh->version == 2 && ssh->mainchan) {
7866 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7867 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7868 ssh2_pkt_addstring(pktout, "signal");
7869 ssh2_pkt_addbool(pktout, 0);
7870 ssh2_pkt_addstring(pktout, signame);
7871 ssh2_pkt_send(ssh, pktout);
7872 logeventf(ssh, "Sent signal SIG%s", signame);
7875 /* Never heard of it. Do nothing */
7880 void *new_sock_channel(void *handle, Socket s)
7882 Ssh ssh = (Ssh) handle;
7883 struct ssh_channel *c;
7884 c = snew(struct ssh_channel);
7888 c->remoteid = -1; /* to be set when open confirmed */
7889 c->localid = alloc_channel_id(ssh);
7891 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
7893 bufchain_init(&c->v.v2.outbuffer);
7894 add234(ssh->channels, c);
7900 * This is called when stdout/stderr (the entity to which
7901 * from_backend sends data) manages to clear some backlog.
7903 static void ssh_unthrottle(void *handle, int bufsize)
7905 Ssh ssh = (Ssh) handle;
7906 if (ssh->version == 1) {
7907 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
7908 ssh->v1_stdout_throttling = 0;
7909 ssh1_throttle(ssh, -1);
7912 if (ssh->mainchan && ssh->mainchan->closes == 0)
7913 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
7917 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
7919 struct ssh_channel *c = (struct ssh_channel *)channel;
7921 struct Packet *pktout;
7923 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
7925 if (ssh->version == 1) {
7926 send_packet(ssh, SSH1_MSG_PORT_OPEN,
7927 PKT_INT, c->localid,
7930 /* PKT_STR, <org:orgport>, */
7933 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7934 ssh2_pkt_addstring(pktout, "direct-tcpip");
7935 ssh2_pkt_adduint32(pktout, c->localid);
7936 c->v.v2.locwindow = OUR_V2_WINSIZE;
7937 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7938 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7939 ssh2_pkt_addstring(pktout, hostname);
7940 ssh2_pkt_adduint32(pktout, port);
7942 * We make up values for the originator data; partly it's
7943 * too much hassle to keep track, and partly I'm not
7944 * convinced the server should be told details like that
7945 * about my local network configuration.
7947 ssh2_pkt_addstring(pktout, "client-side-connection");
7948 ssh2_pkt_adduint32(pktout, 0);
7949 ssh2_pkt_send(ssh, pktout);
7953 static Socket ssh_socket(void *handle)
7955 Ssh ssh = (Ssh) handle;
7959 static int ssh_sendok(void *handle)
7961 Ssh ssh = (Ssh) handle;
7962 return ssh->send_ok;
7965 static int ssh_ldisc(void *handle, int option)
7967 Ssh ssh = (Ssh) handle;
7968 if (option == LD_ECHO)
7969 return ssh->echoing;
7970 if (option == LD_EDIT)
7971 return ssh->editing;
7975 static void ssh_provide_ldisc(void *handle, void *ldisc)
7977 Ssh ssh = (Ssh) handle;
7981 static void ssh_provide_logctx(void *handle, void *logctx)
7983 Ssh ssh = (Ssh) handle;
7984 ssh->logctx = logctx;
7987 static int ssh_return_exitcode(void *handle)
7989 Ssh ssh = (Ssh) handle;
7993 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
7997 * cfg_info for SSH is the currently running version of the
7998 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
8000 static int ssh_cfg_info(void *handle)
8002 Ssh ssh = (Ssh) handle;
8003 return ssh->version;
8007 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
8008 * that fails. This variable is the means by which scp.c can reach
8009 * into the SSH code and find out which one it got.
8011 extern int ssh_fallback_cmd(void *handle)
8013 Ssh ssh = (Ssh) handle;
8014 return ssh->fallback_cmd;
8017 Backend ssh_backend = {
8027 ssh_return_exitcode,