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;
439 /* True if we opened this channel but server hasn't confirmed. */
442 * In SSH1, this value contains four bits:
444 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
445 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
446 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
447 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
449 * A channel is completely finished with when all four bits are set.
453 struct ssh1_data_channel {
456 struct ssh2_data_channel {
458 unsigned remwindow, remmaxpkt;
463 struct ssh_agent_channel {
464 unsigned char *message;
465 unsigned char msglen[4];
466 unsigned lensofar, totallen;
468 struct ssh_x11_channel {
471 struct ssh_pfd_channel {
478 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
479 * 2 use this structure in different ways, reflecting SSH 2's
480 * altogether saner approach to port forwarding.
482 * In SSH 1, you arrange a remote forwarding by sending the server
483 * the remote port number, and the local destination host:port.
484 * When a connection comes in, the server sends you back that
485 * host:port pair, and you connect to it. This is a ready-made
486 * security hole if you're not on the ball: a malicious server
487 * could send you back _any_ host:port pair, so if you trustingly
488 * connect to the address it gives you then you've just opened the
489 * entire inside of your corporate network just by connecting
490 * through it to a dodgy SSH server. Hence, we must store a list of
491 * host:port pairs we _are_ trying to forward to, and reject a
492 * connection request from the server if it's not in the list.
494 * In SSH 2, each side of the connection minds its own business and
495 * doesn't send unnecessary information to the other. You arrange a
496 * remote forwarding by sending the server just the remote port
497 * number. When a connection comes in, the server tells you which
498 * of its ports was connected to; and _you_ have to remember what
499 * local host:port pair went with that port number.
501 * Hence, in SSH 1 this structure is indexed by destination
502 * host:port pair, whereas in SSH 2 it is indexed by source port.
504 struct ssh_portfwd; /* forward declaration */
506 struct ssh_rportfwd {
507 unsigned sport, dport;
510 struct ssh_portfwd *pfrec;
512 #define free_rportfwd(pf) ( \
513 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
516 * Separately to the rportfwd tree (which is for looking up port
517 * open requests from the server), a tree of _these_ structures is
518 * used to keep track of all the currently open port forwardings,
519 * so that we can reconfigure in mid-session if the user requests
523 enum { DESTROY, KEEP, CREATE } status;
525 unsigned sport, dport;
528 struct ssh_rportfwd *remote;
532 #define free_portfwd(pf) ( \
533 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
534 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
538 long forcepad; /* Force padding to at least this length */
540 unsigned long sequence;
545 long encrypted_len; /* for SSH2 total-size counting */
548 * State associated with packet logging
552 struct logblank_t *blanks;
555 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
556 struct Packet *pktin);
557 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
558 struct Packet *pktin);
559 static void ssh1_protocol_setup(Ssh ssh);
560 static void ssh2_protocol_setup(Ssh ssh);
561 static void ssh_size(void *handle, int width, int height);
562 static void ssh_special(void *handle, Telnet_Special);
563 static int ssh2_try_send(struct ssh_channel *c);
564 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
565 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
566 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
567 static int ssh_sendbuffer(void *handle);
568 static int ssh_do_close(Ssh ssh, int notify_exit);
569 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
570 static int ssh2_pkt_getbool(struct Packet *pkt);
571 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
572 static void ssh2_timer(void *ctx, long now);
573 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
574 struct Packet *pktin);
576 struct rdpkt1_state_tag {
577 long len, pad, biglen, to_read;
578 unsigned long realcrc, gotcrc;
582 struct Packet *pktin;
585 struct rdpkt2_state_tag {
586 long len, pad, payload, packetlen, maclen;
589 unsigned long incoming_sequence;
590 struct Packet *pktin;
593 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
594 typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
596 struct queued_handler;
597 struct queued_handler {
599 chandler_fn_t handler;
601 struct queued_handler *next;
605 const struct plug_function_table *fn;
606 /* the above field _must_ be first in the structure */
608 SHA_State exhash, exhashbase;
615 unsigned char session_key[32];
617 int v1_remote_protoflags;
618 int v1_local_protoflags;
619 int agentfwd_enabled;
622 const struct ssh_cipher *cipher;
625 const struct ssh2_cipher *cscipher, *sccipher;
626 void *cs_cipher_ctx, *sc_cipher_ctx;
627 const struct ssh_mac *csmac, *scmac;
628 void *cs_mac_ctx, *sc_mac_ctx;
629 const struct ssh_compress *cscomp, *sccomp;
630 void *cs_comp_ctx, *sc_comp_ctx;
631 const struct ssh_kex *kex;
632 const struct ssh_signkey *hostkey;
633 unsigned char v2_session_id[20];
639 int echoing, editing;
643 int ospeed, ispeed; /* temporaries */
644 int term_width, term_height;
646 tree234 *channels; /* indexed by local id */
647 struct ssh_channel *mainchan; /* primary session channel */
651 tree234 *rportfwds, *portfwds;
655 SSH_STATE_BEFORE_SIZE,
661 int size_needed, eof_needed;
663 struct Packet **queue;
664 int queuelen, queuesize;
666 unsigned char *deferred_send_data;
667 int deferred_len, deferred_size;
670 * Gross hack: pscp will try to start SFTP but fall back to
671 * scp1 if that fails. This variable is the means by which
672 * scp.c can reach into the SSH code and find out which one it
678 * Used for username and password input.
680 char *userpass_input_buffer;
681 int userpass_input_buflen;
682 int userpass_input_bufpos;
683 int userpass_input_echo;
690 int v1_throttle_count;
693 int v1_stdout_throttling;
694 unsigned long v2_outgoing_sequence;
696 int ssh1_rdpkt_crstate;
697 int ssh2_rdpkt_crstate;
698 int do_ssh_init_crstate;
699 int ssh_gotdata_crstate;
700 int do_ssh1_login_crstate;
701 int do_ssh1_connection_crstate;
702 int do_ssh2_transport_crstate;
703 int do_ssh2_authconn_crstate;
705 void *do_ssh_init_state;
706 void *do_ssh1_login_state;
707 void *do_ssh2_transport_state;
708 void *do_ssh2_authconn_state;
710 struct rdpkt1_state_tag rdpkt1_state;
711 struct rdpkt2_state_tag rdpkt2_state;
713 /* ssh1 and ssh2 use this for different things, but both use it */
714 int protocol_initial_phase_done;
716 void (*protocol) (Ssh ssh, void *vin, int inlen,
718 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
721 * We maintain a full _copy_ of a Config structure here, not
722 * merely a pointer to it. That way, when we're passed a new
723 * one for reconfiguration, we can check the differences and
724 * potentially reconfigure port forwardings etc in mid-session.
729 * Used to transfer data back from async agent callbacks.
731 void *agent_response;
732 int agent_response_len;
735 * Dispatch table for packet types that we may have to deal
738 handler_fn_t packet_dispatch[256];
741 * Queues of one-off handler functions for success/failure
742 * indications from a request.
744 struct queued_handler *qhead, *qtail;
747 * This module deals with sending keepalives.
752 * Track incoming and outgoing data sizes and time, for
755 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
756 unsigned long max_data_size;
758 long next_rekey, last_rekey;
759 char *deferred_rekey_reason; /* points to STATIC string; don't free */
762 #define logevent(s) logevent(ssh->frontend, s)
764 /* logevent, only printf-formatted. */
765 static void logeventf(Ssh ssh, const char *fmt, ...)
771 buf = dupvprintf(fmt, ap);
777 #define bombout(msg) \
779 char *text = dupprintf msg; \
780 ssh_do_close(ssh, FALSE); \
782 connection_fatal(ssh->frontend, "%s", text); \
786 /* Functions to leave bits out of the SSH packet log file. */
788 static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
790 if (ssh->cfg.logomitpass)
791 pkt->logmode = blanktype;
794 static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
796 if (ssh->cfg.logomitdata)
797 pkt->logmode = blanktype;
800 static void end_log_omission(Ssh ssh, struct Packet *pkt)
802 pkt->logmode = PKTLOG_EMIT;
805 static int ssh_channelcmp(void *av, void *bv)
807 struct ssh_channel *a = (struct ssh_channel *) av;
808 struct ssh_channel *b = (struct ssh_channel *) bv;
809 if (a->localid < b->localid)
811 if (a->localid > b->localid)
815 static int ssh_channelfind(void *av, void *bv)
817 unsigned *a = (unsigned *) av;
818 struct ssh_channel *b = (struct ssh_channel *) bv;
826 static int ssh_rportcmp_ssh1(void *av, void *bv)
828 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
829 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
831 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
832 return i < 0 ? -1 : +1;
833 if (a->dport > b->dport)
835 if (a->dport < b->dport)
840 static int ssh_rportcmp_ssh2(void *av, void *bv)
842 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
843 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
845 if (a->sport > b->sport)
847 if (a->sport < b->sport)
853 * Special form of strcmp which can cope with NULL inputs. NULL is
854 * defined to sort before even the empty string.
856 static int nullstrcmp(const char *a, const char *b)
858 if (a == NULL && b == NULL)
867 static int ssh_portcmp(void *av, void *bv)
869 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
870 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
872 if (a->type > b->type)
874 if (a->type < b->type)
876 if (a->addressfamily > b->addressfamily)
878 if (a->addressfamily < b->addressfamily)
880 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
881 return i < 0 ? -1 : +1;
882 if (a->sport > b->sport)
884 if (a->sport < b->sport)
886 if (a->type != 'D') {
887 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
888 return i < 0 ? -1 : +1;
889 if (a->dport > b->dport)
891 if (a->dport < b->dport)
897 static int alloc_channel_id(Ssh ssh)
899 const unsigned CHANNEL_NUMBER_OFFSET = 256;
900 unsigned low, high, mid;
902 struct ssh_channel *c;
905 * First-fit allocation of channel numbers: always pick the
906 * lowest unused one. To do this, binary-search using the
907 * counted B-tree to find the largest channel ID which is in a
908 * contiguous sequence from the beginning. (Precisely
909 * everything in that sequence must have ID equal to its tree
910 * index plus CHANNEL_NUMBER_OFFSET.)
912 tsize = count234(ssh->channels);
916 while (high - low > 1) {
917 mid = (high + low) / 2;
918 c = index234(ssh->channels, mid);
919 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
920 low = mid; /* this one is fine */
922 high = mid; /* this one is past it */
925 * Now low points to either -1, or the tree index of the
926 * largest ID in the initial sequence.
929 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
930 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
932 return low + 1 + CHANNEL_NUMBER_OFFSET;
935 static void c_write(Ssh ssh, const char *buf, int len)
937 if ((flags & FLAG_STDERR)) {
939 for (i = 0; i < len; i++)
941 fputc(buf[i], stderr);
944 from_backend(ssh->frontend, 1, buf, len);
947 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
950 for (i = 0; i < len; i++) {
952 c_write(ssh, "\r\n", 2);
953 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
954 c_write(ssh, buf + i, 1);
958 static void c_write_str(Ssh ssh, const char *buf)
960 c_write(ssh, buf, strlen(buf));
963 static void ssh_free_packet(struct Packet *pkt)
968 static struct Packet *ssh_new_packet(void)
970 struct Packet *pkt = snew(struct Packet);
974 pkt->logmode = PKTLOG_EMIT;
982 * Collect incoming data in the incoming packet buffer.
983 * Decipher and verify the packet when it is completely read.
984 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
985 * Update the *data and *datalen variables.
986 * Return a Packet structure when a packet is completed.
988 static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
990 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
992 crBegin(ssh->ssh1_rdpkt_crstate);
994 st->pktin = ssh_new_packet();
997 st->pktin->length = 0;
999 for (st->i = st->len = 0; st->i < 4; st->i++) {
1000 while ((*datalen) == 0)
1002 st->len = (st->len << 8) + **data;
1003 (*data)++, (*datalen)--;
1006 st->pad = 8 - (st->len % 8);
1007 st->biglen = st->len + st->pad;
1008 st->pktin->length = st->len - 5;
1010 if (st->biglen < 0) {
1011 bombout(("Extremely large packet length from server suggests"
1012 " data stream corruption"));
1013 ssh_free_packet(st->pktin);
1017 st->pktin->maxlen = st->biglen;
1018 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1020 st->to_read = st->biglen;
1021 st->p = st->pktin->data;
1022 while (st->to_read > 0) {
1023 st->chunk = st->to_read;
1024 while ((*datalen) == 0)
1026 if (st->chunk > (*datalen))
1027 st->chunk = (*datalen);
1028 memcpy(st->p, *data, st->chunk);
1030 *datalen -= st->chunk;
1032 st->to_read -= st->chunk;
1035 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1036 st->biglen, NULL)) {
1037 bombout(("Network attack (CRC compensation) detected!"));
1038 ssh_free_packet(st->pktin);
1043 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1045 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1046 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1047 if (st->gotcrc != st->realcrc) {
1048 bombout(("Incorrect CRC received on packet"));
1049 ssh_free_packet(st->pktin);
1053 st->pktin->body = st->pktin->data + st->pad + 1;
1054 st->pktin->savedpos = 0;
1056 if (ssh->v1_compressing) {
1057 unsigned char *decompblk;
1059 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1060 st->pktin->body - 1, st->pktin->length + 1,
1061 &decompblk, &decomplen)) {
1062 bombout(("Zlib decompression encountered invalid data"));
1063 ssh_free_packet(st->pktin);
1067 if (st->pktin->maxlen < st->pad + decomplen) {
1068 st->pktin->maxlen = st->pad + decomplen;
1069 st->pktin->data = sresize(st->pktin->data,
1070 st->pktin->maxlen + APIEXTRA,
1072 st->pktin->body = st->pktin->data + st->pad + 1;
1075 memcpy(st->pktin->body - 1, decompblk, decomplen);
1077 st->pktin->length = decomplen - 1;
1080 st->pktin->type = st->pktin->body[-1];
1083 * Log incoming packet, possibly omitting sensitive fields.
1087 struct logblank_t blank;
1088 if (ssh->cfg.logomitdata) {
1089 int do_blank = FALSE, blank_prefix = 0;
1090 /* "Session data" packets - omit the data field */
1091 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1092 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
1093 do_blank = TRUE; blank_prefix = 0;
1094 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
1095 do_blank = TRUE; blank_prefix = 4;
1098 blank.offset = blank_prefix;
1099 blank.len = st->pktin->length;
1100 blank.type = PKTLOG_OMIT;
1104 log_packet(ssh->logctx,
1105 PKT_INCOMING, st->pktin->type,
1106 ssh1_pkt_type(st->pktin->type),
1107 st->pktin->body, st->pktin->length,
1111 crFinish(st->pktin);
1114 static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1116 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1118 crBegin(ssh->ssh2_rdpkt_crstate);
1120 st->pktin = ssh_new_packet();
1122 st->pktin->type = 0;
1123 st->pktin->length = 0;
1125 st->cipherblk = ssh->sccipher->blksize;
1128 if (st->cipherblk < 8)
1131 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1134 * Acquire and decrypt the first block of the packet. This will
1135 * contain the length and padding details.
1137 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1138 while ((*datalen) == 0)
1140 st->pktin->data[st->i] = *(*data)++;
1145 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1146 st->pktin->data, st->cipherblk);
1149 * Now get the length and padding figures.
1151 st->len = GET_32BIT(st->pktin->data);
1152 st->pad = st->pktin->data[4];
1155 * _Completely_ silly lengths should be stomped on before they
1156 * do us any more damage.
1158 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
1159 bombout(("Incoming packet was garbled on decryption"));
1160 ssh_free_packet(st->pktin);
1165 * This enables us to deduce the payload length.
1167 st->payload = st->len - st->pad - 1;
1169 st->pktin->length = st->payload + 5;
1172 * So now we can work out the total packet length.
1174 st->packetlen = st->len + 4;
1175 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1178 * Allocate memory for the rest of the packet.
1180 st->pktin->maxlen = st->packetlen + st->maclen;
1181 st->pktin->data = sresize(st->pktin->data,
1182 st->pktin->maxlen + APIEXTRA,
1186 * Read and decrypt the remainder of the packet.
1188 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1190 while ((*datalen) == 0)
1192 st->pktin->data[st->i] = *(*data)++;
1195 /* Decrypt everything _except_ the MAC. */
1197 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1198 st->pktin->data + st->cipherblk,
1199 st->packetlen - st->cipherblk);
1201 st->pktin->encrypted_len = st->packetlen;
1207 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, st->len + 4,
1208 st->incoming_sequence)) {
1209 bombout(("Incorrect MAC received on packet"));
1210 ssh_free_packet(st->pktin);
1214 st->pktin->sequence = st->incoming_sequence++;
1217 * Decompress packet payload.
1220 unsigned char *newpayload;
1223 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1224 st->pktin->data + 5, st->pktin->length - 5,
1225 &newpayload, &newlen)) {
1226 if (st->pktin->maxlen < newlen + 5) {
1227 st->pktin->maxlen = newlen + 5;
1228 st->pktin->data = sresize(st->pktin->data,
1229 st->pktin->maxlen + APIEXTRA,
1232 st->pktin->length = 5 + newlen;
1233 memcpy(st->pktin->data + 5, newpayload, newlen);
1238 st->pktin->savedpos = 6;
1239 st->pktin->body = st->pktin->data;
1240 st->pktin->type = st->pktin->data[5];
1243 * Log incoming packet, possibly omitting sensitive fields.
1247 struct logblank_t blank;
1248 if (ssh->cfg.logomitdata) {
1249 int do_blank = FALSE, blank_prefix = 0;
1250 /* "Session data" packets - omit the data field */
1251 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
1252 do_blank = TRUE; blank_prefix = 4;
1253 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1254 do_blank = TRUE; blank_prefix = 8;
1257 blank.offset = blank_prefix;
1258 blank.len = (st->pktin->length-6) - blank_prefix;
1259 blank.type = PKTLOG_OMIT;
1263 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1264 ssh2_pkt_type(ssh->pkt_ctx, st->pktin->type),
1265 st->pktin->data+6, st->pktin->length-6,
1269 crFinish(st->pktin);
1272 static void ssh1_pktout_size(struct Packet *pkt, int len)
1276 len += 5; /* type and CRC */
1277 pad = 8 - (len % 8);
1280 pkt->length = len - 5;
1281 if (pkt->maxlen < biglen) {
1282 pkt->maxlen = biglen;
1283 pkt->data = sresize(pkt->data, biglen + 4 + APIEXTRA, unsigned char);
1285 pkt->body = pkt->data + 4 + pad + 1;
1288 static struct Packet *s_wrpkt_start(int type, int len)
1290 struct Packet *pkt = ssh_new_packet();
1291 ssh1_pktout_size(pkt, len);
1293 /* Initialise log omission state */
1299 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt)
1305 * XXX various versions of SC (including 8.8.4) screw up the
1306 * register allocation in this function and use the same register
1307 * (D6) for len and as a temporary, with predictable results. The
1308 * following sledgehammer prevents this.
1314 pkt->body[-1] = pkt->type;
1317 log_packet(ssh->logctx, PKT_OUTGOING, pkt->type,
1318 ssh1_pkt_type(pkt->type),
1319 pkt->body, pkt->length,
1320 pkt->nblanks, pkt->blanks);
1321 sfree(pkt->blanks); pkt->blanks = NULL;
1324 if (ssh->v1_compressing) {
1325 unsigned char *compblk;
1327 zlib_compress_block(ssh->cs_comp_ctx,
1328 pkt->body - 1, pkt->length + 1,
1329 &compblk, &complen);
1330 ssh1_pktout_size(pkt, complen - 1);
1331 memcpy(pkt->body - 1, compblk, complen);
1335 len = pkt->length + 5; /* type and CRC */
1336 pad = 8 - (len % 8);
1339 for (i = 0; i < pad; i++)
1340 pkt->data[i + 4] = random_byte();
1341 crc = crc32_compute(pkt->data + 4, biglen - 4);
1342 PUT_32BIT(pkt->data + biglen, crc);
1343 PUT_32BIT(pkt->data, len);
1346 ssh->cipher->encrypt(ssh->v1_cipher_ctx, pkt->data + 4, biglen);
1351 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1354 len = s_wrpkt_prepare(ssh, pkt);
1355 backlog = sk_write(ssh->s, (char *)pkt->data, len);
1356 if (backlog > SSH_MAX_BACKLOG)
1357 ssh_throttle_all(ssh, 1, backlog);
1360 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1363 len = s_wrpkt_prepare(ssh, pkt);
1364 if (ssh->deferred_len + len > ssh->deferred_size) {
1365 ssh->deferred_size = ssh->deferred_len + len + 128;
1366 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1370 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
1371 ssh->deferred_len += len;
1375 * Construct a packet with the specified contents.
1377 static struct Packet *construct_packet(Ssh ssh, int pkttype,
1378 va_list ap1, va_list ap2)
1380 unsigned char *p, *argp, argchar;
1381 unsigned long argint;
1382 int pktlen, argtype, arglen;
1387 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1390 (void) va_arg(ap1, int);
1394 (void) va_arg(ap1, int);
1398 (void) va_arg(ap1, unsigned char *);
1399 arglen = va_arg(ap1, int);
1403 argp = va_arg(ap1, unsigned char *);
1404 arglen = strlen((char *)argp);
1405 pktlen += 4 + arglen;
1408 bn = va_arg(ap1, Bignum);
1409 pktlen += ssh1_bignum_length(bn);
1414 /* ignore this pass */
1421 pkt = s_wrpkt_start(pkttype, pktlen);
1424 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1425 int offset = p - pkt->body, len = 0;
1427 /* Actual fields in the packet */
1429 argint = va_arg(ap2, int);
1430 PUT_32BIT(p, argint);
1434 argchar = (unsigned char) va_arg(ap2, int);
1439 argp = va_arg(ap2, unsigned char *);
1440 arglen = va_arg(ap2, int);
1441 memcpy(p, argp, arglen);
1445 argp = va_arg(ap2, unsigned char *);
1446 arglen = strlen((char *)argp);
1447 PUT_32BIT(p, arglen);
1448 memcpy(p + 4, argp, arglen);
1452 bn = va_arg(ap2, Bignum);
1453 len = ssh1_write_bignum(p, bn);
1455 /* Tokens for modifications to packet logging */
1457 dont_log_password(ssh, pkt, PKTLOG_BLANK);
1460 dont_log_data(ssh, pkt, PKTLOG_OMIT);
1463 end_log_omission(ssh, pkt);
1467 /* Deal with logfile omission, if required. */
1468 if (len && (pkt->logmode != PKTLOG_EMIT)) {
1470 pkt->blanks = sresize(pkt->blanks, pkt->nblanks,
1472 pkt->blanks[pkt->nblanks-1].offset = offset;
1473 pkt->blanks[pkt->nblanks-1].len = len;
1474 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1481 static void send_packet(Ssh ssh, int pkttype, ...)
1485 va_start(ap1, pkttype);
1486 va_start(ap2, pkttype);
1487 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1491 ssh_free_packet(pkt);
1494 static void defer_packet(Ssh ssh, int pkttype, ...)
1498 va_start(ap1, pkttype);
1499 va_start(ap2, pkttype);
1500 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1503 s_wrpkt_defer(ssh, pkt);
1504 ssh_free_packet(pkt);
1507 static int ssh_versioncmp(char *a, char *b)
1510 unsigned long av, bv;
1512 av = strtoul(a, &ae, 10);
1513 bv = strtoul(b, &be, 10);
1515 return (av < bv ? -1 : +1);
1520 av = strtoul(ae, &ae, 10);
1521 bv = strtoul(be, &be, 10);
1523 return (av < bv ? -1 : +1);
1528 * Utility routines for putting an SSH-protocol `string' and
1529 * `uint32' into a SHA state.
1532 static void sha_string(SHA_State * s, void *str, int len)
1534 unsigned char lenblk[4];
1535 PUT_32BIT(lenblk, len);
1536 SHA_Bytes(s, lenblk, 4);
1537 SHA_Bytes(s, str, len);
1540 static void sha_uint32(SHA_State * s, unsigned i)
1542 unsigned char intblk[4];
1543 PUT_32BIT(intblk, i);
1544 SHA_Bytes(s, intblk, 4);
1548 * SSH2 packet construction functions.
1550 static void ssh2_pkt_ensure(struct Packet *pkt, int length)
1552 if (pkt->maxlen < length) {
1553 pkt->maxlen = length + 256;
1554 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
1557 static void ssh2_pkt_adddata(struct Packet *pkt, void *data, int len)
1559 if (pkt->logmode != PKTLOG_EMIT) {
1561 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1562 pkt->blanks[pkt->nblanks-1].offset = pkt->length - 6;
1563 pkt->blanks[pkt->nblanks-1].len = len;
1564 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1567 ssh2_pkt_ensure(pkt, pkt->length);
1568 memcpy(pkt->data + pkt->length - len, data, len);
1570 static void ssh2_pkt_addbyte(struct Packet *pkt, unsigned char byte)
1572 ssh2_pkt_adddata(pkt, &byte, 1);
1574 static struct Packet *ssh2_pkt_init(int pkt_type)
1576 struct Packet *pkt = ssh_new_packet();
1579 ssh2_pkt_addbyte(pkt, (unsigned char) pkt_type);
1582 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
1584 ssh2_pkt_adddata(pkt, &value, 1);
1586 static void ssh2_pkt_adduint32(struct Packet *pkt, unsigned long value)
1589 PUT_32BIT(x, value);
1590 ssh2_pkt_adddata(pkt, x, 4);
1592 static void ssh2_pkt_addstring_start(struct Packet *pkt)
1594 ssh2_pkt_adduint32(pkt, 0);
1595 pkt->savedpos = pkt->length;
1597 static void ssh2_pkt_addstring_str(struct Packet *pkt, char *data)
1599 ssh2_pkt_adddata(pkt, data, strlen(data));
1600 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1602 static void ssh2_pkt_addstring_data(struct Packet *pkt, char *data, int len)
1604 ssh2_pkt_adddata(pkt, data, len);
1605 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1607 static void ssh2_pkt_addstring(struct Packet *pkt, char *data)
1609 ssh2_pkt_addstring_start(pkt);
1610 ssh2_pkt_addstring_str(pkt, data);
1612 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1615 int i, n = (bignum_bitcount(b) + 7) / 8;
1616 p = snewn(n + 1, unsigned char);
1618 fatalbox("out of memory");
1620 for (i = 1; i <= n; i++)
1621 p[i] = bignum_byte(b, n - i);
1623 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1625 memmove(p, p + i, n + 1 - i);
1629 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
1633 p = ssh2_mpint_fmt(b, &len);
1634 ssh2_pkt_addstring_start(pkt);
1635 ssh2_pkt_addstring_data(pkt, (char *)p, len);
1640 * Construct an SSH2 final-form packet: compress it, encrypt it,
1641 * put the MAC on it. Final packet, ready to be sent, is stored in
1642 * pkt->data. Total length is returned.
1644 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
1646 int cipherblk, maclen, padding, i;
1649 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1650 ssh2_pkt_type(ssh->pkt_ctx, pkt->data[5]),
1651 pkt->data + 6, pkt->length - 6,
1652 pkt->nblanks, pkt->blanks);
1653 sfree(pkt->blanks); pkt->blanks = NULL;
1657 * Compress packet payload.
1660 unsigned char *newpayload;
1663 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1665 &newpayload, &newlen)) {
1667 ssh2_pkt_adddata(pkt, newpayload, newlen);
1673 * Add padding. At least four bytes, and must also bring total
1674 * length (minus MAC) up to a multiple of the block size.
1675 * If pkt->forcepad is set, make sure the packet is at least that size
1678 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1679 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1681 if (pkt->length + padding < pkt->forcepad)
1682 padding = pkt->forcepad - pkt->length;
1684 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
1685 assert(padding <= 255);
1686 maclen = ssh->csmac ? ssh->csmac->len : 0;
1687 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1688 pkt->data[4] = padding;
1689 for (i = 0; i < padding; i++)
1690 pkt->data[pkt->length + i] = random_byte();
1691 PUT_32BIT(pkt->data, pkt->length + padding - 4);
1693 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1694 pkt->length + padding,
1695 ssh->v2_outgoing_sequence);
1696 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1699 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1700 pkt->data, pkt->length + padding);
1702 pkt->encrypted_len = pkt->length + padding;
1704 /* Ready-to-send packet starts at pkt->data. We return length. */
1705 return pkt->length + padding + maclen;
1709 * Routines called from the main SSH code to send packets. There
1710 * are quite a few of these, because we have two separate
1711 * mechanisms for delaying the sending of packets:
1713 * - In order to send an IGNORE message and a password message in
1714 * a single fixed-length blob, we require the ability to
1715 * concatenate the encrypted forms of those two packets _into_ a
1716 * single blob and then pass it to our <network.h> transport
1717 * layer in one go. Hence, there's a deferment mechanism which
1718 * works after packet encryption.
1720 * - In order to avoid sending any connection-layer messages
1721 * during repeat key exchange, we have to queue up any such
1722 * outgoing messages _before_ they are encrypted (and in
1723 * particular before they're allocated sequence numbers), and
1724 * then send them once we've finished.
1726 * I call these mechanisms `defer' and `queue' respectively, so as
1727 * to distinguish them reasonably easily.
1729 * The functions send_noqueue() and defer_noqueue() free the packet
1730 * structure they are passed. Every outgoing packet goes through
1731 * precisely one of these functions in its life; packets passed to
1732 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
1733 * these or get queued, and then when the queue is later emptied
1734 * the packets are all passed to defer_noqueue().
1738 * Send an SSH2 packet immediately, without queuing or deferring.
1740 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
1744 len = ssh2_pkt_construct(ssh, pkt);
1745 backlog = sk_write(ssh->s, (char *)pkt->data, len);
1746 if (backlog > SSH_MAX_BACKLOG)
1747 ssh_throttle_all(ssh, 1, backlog);
1749 ssh->outgoing_data_size += pkt->encrypted_len;
1750 if (!ssh->kex_in_progress &&
1751 ssh->max_data_size != 0 &&
1752 ssh->outgoing_data_size > ssh->max_data_size)
1753 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
1755 ssh_free_packet(pkt);
1759 * Defer an SSH2 packet.
1761 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt)
1763 int len = ssh2_pkt_construct(ssh, pkt);
1764 if (ssh->deferred_len + len > ssh->deferred_size) {
1765 ssh->deferred_size = ssh->deferred_len + len + 128;
1766 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1770 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
1771 ssh->deferred_len += len;
1772 ssh->deferred_data_size += pkt->encrypted_len;
1773 ssh_free_packet(pkt);
1777 * Queue an SSH2 packet.
1779 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
1781 assert(ssh->queueing);
1783 if (ssh->queuelen >= ssh->queuesize) {
1784 ssh->queuesize = ssh->queuelen + 32;
1785 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
1788 ssh->queue[ssh->queuelen++] = pkt;
1792 * Either queue or send a packet, depending on whether queueing is
1795 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
1798 ssh2_pkt_queue(ssh, pkt);
1800 ssh2_pkt_send_noqueue(ssh, pkt);
1805 * Either queue or defer a packet, depending on whether queueing is
1808 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
1811 ssh2_pkt_queue(ssh, pkt);
1813 ssh2_pkt_defer_noqueue(ssh, pkt);
1818 * Send the whole deferred data block constructed by
1819 * ssh2_pkt_defer() or SSH1's defer_packet().
1821 * The expected use of the defer mechanism is that you call
1822 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
1823 * not currently queueing, this simply sets up deferred_send_data
1824 * and then sends it. If we _are_ currently queueing, the calls to
1825 * ssh2_pkt_defer() put the deferred packets on to the queue
1826 * instead, and therefore ssh_pkt_defersend() has no deferred data
1827 * to send. Hence, there's no need to make it conditional on
1830 static void ssh_pkt_defersend(Ssh ssh)
1833 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1835 ssh->deferred_len = ssh->deferred_size = 0;
1836 sfree(ssh->deferred_send_data);
1837 ssh->deferred_send_data = NULL;
1838 if (backlog > SSH_MAX_BACKLOG)
1839 ssh_throttle_all(ssh, 1, backlog);
1841 ssh->outgoing_data_size += ssh->deferred_data_size;
1842 if (!ssh->kex_in_progress &&
1843 ssh->max_data_size != 0 &&
1844 ssh->outgoing_data_size > ssh->max_data_size)
1845 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
1846 ssh->deferred_data_size = 0;
1850 * Send all queued SSH2 packets. We send them by means of
1851 * ssh2_pkt_defer_noqueue(), in case they included a pair of
1852 * packets that needed to be lumped together.
1854 static void ssh2_pkt_queuesend(Ssh ssh)
1858 assert(!ssh->queueing);
1860 for (i = 0; i < ssh->queuelen; i++)
1861 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i]);
1864 ssh_pkt_defersend(ssh);
1868 void bndebug(char *string, Bignum b)
1872 p = ssh2_mpint_fmt(b, &len);
1873 debug(("%s", string));
1874 for (i = 0; i < len; i++)
1875 debug((" %02x", p[i]));
1881 static void sha_mpint(SHA_State * s, Bignum b)
1885 p = ssh2_mpint_fmt(b, &len);
1886 sha_string(s, p, len);
1891 * Packet decode functions for both SSH1 and SSH2.
1893 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
1895 unsigned long value;
1896 if (pkt->length - pkt->savedpos < 4)
1897 return 0; /* arrgh, no way to decline (FIXME?) */
1898 value = GET_32BIT(pkt->body + pkt->savedpos);
1902 static int ssh2_pkt_getbool(struct Packet *pkt)
1904 unsigned long value;
1905 if (pkt->length - pkt->savedpos < 1)
1906 return 0; /* arrgh, no way to decline (FIXME?) */
1907 value = pkt->body[pkt->savedpos] != 0;
1911 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
1916 if (pkt->length - pkt->savedpos < 4)
1918 len = GET_32BIT(pkt->body + pkt->savedpos);
1923 if (pkt->length - pkt->savedpos < *length)
1925 *p = (char *)(pkt->body + pkt->savedpos);
1926 pkt->savedpos += *length;
1928 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
1930 if (pkt->length - pkt->savedpos < length)
1932 pkt->savedpos += length;
1933 return pkt->body + (pkt->savedpos - length);
1935 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
1936 unsigned char **keystr)
1940 j = makekey(pkt->body + pkt->savedpos,
1941 pkt->length - pkt->savedpos,
1948 assert(pkt->savedpos < pkt->length);
1952 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
1957 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
1958 pkt->length - pkt->savedpos, &b);
1966 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
1972 ssh_pkt_getstring(pkt, &p, &length);
1977 b = bignum_from_bytes((unsigned char *)p, length);
1982 * Helper function to add an SSH2 signature blob to a packet.
1983 * Expects to be shown the public key blob as well as the signature
1984 * blob. Normally works just like ssh2_pkt_addstring, but will
1985 * fiddle with the signature packet if necessary for
1986 * BUG_SSH2_RSA_PADDING.
1988 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
1989 void *pkblob_v, int pkblob_len,
1990 void *sigblob_v, int sigblob_len)
1992 unsigned char *pkblob = (unsigned char *)pkblob_v;
1993 unsigned char *sigblob = (unsigned char *)sigblob_v;
1995 /* dmemdump(pkblob, pkblob_len); */
1996 /* dmemdump(sigblob, sigblob_len); */
1999 * See if this is in fact an ssh-rsa signature and a buggy
2000 * server; otherwise we can just do this the easy way.
2002 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
2003 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2004 int pos, len, siglen;
2007 * Find the byte length of the modulus.
2010 pos = 4+7; /* skip over "ssh-rsa" */
2011 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
2012 len = GET_32BIT(pkblob+pos); /* find length of modulus */
2013 pos += 4; /* find modulus itself */
2014 while (len > 0 && pkblob[pos] == 0)
2016 /* debug(("modulus length is %d\n", len)); */
2019 * Now find the signature integer.
2021 pos = 4+7; /* skip over "ssh-rsa" */
2022 siglen = GET_32BIT(sigblob+pos);
2023 /* debug(("signature length is %d\n", siglen)); */
2025 if (len != siglen) {
2026 unsigned char newlen[4];
2027 ssh2_pkt_addstring_start(pkt);
2028 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2029 /* dmemdump(sigblob, pos); */
2030 pos += 4; /* point to start of actual sig */
2031 PUT_32BIT(newlen, len);
2032 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2033 /* dmemdump(newlen, 4); */
2035 while (len-- > siglen) {
2036 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2037 /* dmemdump(newlen, 1); */
2039 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2040 /* dmemdump(sigblob+pos, siglen); */
2044 /* Otherwise fall through and do it the easy way. */
2047 ssh2_pkt_addstring_start(pkt);
2048 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2052 * Examine the remote side's version string and compare it against
2053 * a list of known buggy implementations.
2055 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2057 char *imp; /* pointer to implementation part */
2059 imp += strcspn(imp, "-");
2061 imp += strcspn(imp, "-");
2064 ssh->remote_bugs = 0;
2066 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
2067 (ssh->cfg.sshbug_ignore1 == AUTO &&
2068 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2069 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2070 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2071 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2073 * These versions don't support SSH1_MSG_IGNORE, so we have
2074 * to use a different defence against password length
2077 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2078 logevent("We believe remote version has SSH1 ignore bug");
2081 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
2082 (ssh->cfg.sshbug_plainpw1 == AUTO &&
2083 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2085 * These versions need a plain password sent; they can't
2086 * handle having a null and a random length of data after
2089 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2090 logevent("We believe remote version needs a plain SSH1 password");
2093 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
2094 (ssh->cfg.sshbug_rsa1 == AUTO &&
2095 (!strcmp(imp, "Cisco-1.25")))) {
2097 * These versions apparently have no clue whatever about
2098 * RSA authentication and will panic and die if they see
2099 * an AUTH_RSA message.
2101 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2102 logevent("We believe remote version can't handle RSA authentication");
2105 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2106 (ssh->cfg.sshbug_hmac2 == AUTO &&
2107 !wc_match("* VShell", imp) &&
2108 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2109 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2110 wc_match("2.1 *", imp)))) {
2112 * These versions have the HMAC bug.
2114 ssh->remote_bugs |= BUG_SSH2_HMAC;
2115 logevent("We believe remote version has SSH2 HMAC bug");
2118 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2119 (ssh->cfg.sshbug_derivekey2 == AUTO &&
2120 !wc_match("* VShell", imp) &&
2121 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2123 * These versions have the key-derivation bug (failing to
2124 * include the literal shared secret in the hashes that
2125 * generate the keys).
2127 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2128 logevent("We believe remote version has SSH2 key-derivation bug");
2131 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2132 (ssh->cfg.sshbug_rsapad2 == AUTO &&
2133 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2134 wc_match("OpenSSH_3.[0-2]*", imp)))) {
2136 * These versions have the SSH2 RSA padding bug.
2138 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2139 logevent("We believe remote version has SSH2 RSA padding bug");
2142 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2143 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2144 wc_match("OpenSSH_2.[0-2]*", imp))) {
2146 * These versions have the SSH2 session-ID bug in
2147 * public-key authentication.
2149 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2150 logevent("We believe remote version has SSH2 public-key-session-ID bug");
2153 if (ssh->cfg.sshbug_rekey2 == FORCE_ON ||
2154 (ssh->cfg.sshbug_rekey2 == AUTO &&
2155 (wc_match("OpenSSH_2.[0-4]*", imp) ||
2156 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2157 wc_match("Sun_SSH_1.0", imp) ||
2158 wc_match("Sun_SSH_1.0.1", imp)))) {
2160 * These versions have the SSH2 rekey bug.
2162 ssh->remote_bugs |= BUG_SSH2_REKEY;
2163 logevent("We believe remote version has SSH2 rekey bug");
2168 * The `software version' part of an SSH version string is required
2169 * to contain no spaces or minus signs.
2171 static void ssh_fix_verstring(char *str)
2173 /* Eat "SSH-<protoversion>-". */
2174 assert(*str == 'S'); str++;
2175 assert(*str == 'S'); str++;
2176 assert(*str == 'H'); str++;
2177 assert(*str == '-'); str++;
2178 while (*str && *str != '-') str++;
2179 assert(*str == '-'); str++;
2181 /* Convert minus signs and spaces in the remaining string into
2184 if (*str == '-' || *str == ' ')
2190 static int do_ssh_init(Ssh ssh, unsigned char c)
2192 struct do_ssh_init_state {
2200 crState(do_ssh_init_state);
2202 crBegin(ssh->do_ssh_init_crstate);
2204 /* Search for the string "SSH-" in the input. */
2207 static const int transS[] = { 1, 2, 2, 1 };
2208 static const int transH[] = { 0, 0, 3, 0 };
2209 static const int transminus[] = { 0, 0, 0, -1 };
2211 s->i = transS[s->i];
2213 s->i = transH[s->i];
2215 s->i = transminus[s->i];
2220 crReturn(1); /* get another character */
2224 s->vstring = snewn(s->vstrsize, char);
2225 strcpy(s->vstring, "SSH-");
2229 crReturn(1); /* get another char */
2230 if (s->vslen >= s->vstrsize - 1) {
2232 s->vstring = sresize(s->vstring, s->vstrsize, char);
2234 s->vstring[s->vslen++] = c;
2237 s->version[s->i] = '\0';
2239 } else if (s->i < sizeof(s->version) - 1)
2240 s->version[s->i++] = c;
2241 } else if (c == '\012')
2245 ssh->agentfwd_enabled = FALSE;
2246 ssh->rdpkt2_state.incoming_sequence = 0;
2248 s->vstring[s->vslen] = 0;
2249 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2252 vlog = snewn(20 + s->vslen, char);
2253 sprintf(vlog, "Server version: %s", s->vstring);
2257 ssh_detect_bugs(ssh, s->vstring);
2260 * Decide which SSH protocol version to support.
2263 /* Anything strictly below "2.0" means protocol 1 is supported. */
2264 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2265 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2266 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2268 if (ssh->cfg.sshprot == 0 && !s->proto1) {
2269 bombout(("SSH protocol version 1 required by user but not provided by server"));
2272 if (ssh->cfg.sshprot == 3 && !s->proto2) {
2273 bombout(("SSH protocol version 2 required by user but not provided by server"));
2280 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2282 * Construct a v2 version string.
2284 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2288 * Construct a v1 version string.
2290 verstring = dupprintf("SSH-%s-%s\012",
2291 (ssh_versioncmp(s->version, "1.5") <= 0 ?
2292 s->version : "1.5"),
2297 ssh_fix_verstring(verstring);
2299 if (ssh->version == 2) {
2301 * Hash our version string and their version string.
2303 SHA_Init(&ssh->exhashbase);
2304 sha_string(&ssh->exhashbase, verstring,
2305 strcspn(verstring, "\015\012"));
2306 sha_string(&ssh->exhashbase, s->vstring,
2307 strcspn(s->vstring, "\015\012"));
2310 * Initialise SSHv2 protocol.
2312 ssh->protocol = ssh2_protocol;
2313 ssh2_protocol_setup(ssh);
2314 ssh->s_rdpkt = ssh2_rdpkt;
2317 * Initialise SSHv1 protocol.
2319 ssh->protocol = ssh1_protocol;
2320 ssh1_protocol_setup(ssh);
2321 ssh->s_rdpkt = ssh1_rdpkt;
2323 logeventf(ssh, "We claim version: %.*s",
2324 strcspn(verstring, "\015\012"), verstring);
2325 sk_write(ssh->s, verstring, strlen(verstring));
2329 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2331 update_specials_menu(ssh->frontend);
2332 ssh->state = SSH_STATE_BEFORE_SIZE;
2333 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
2340 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2342 crBegin(ssh->ssh_gotdata_crstate);
2345 * To begin with, feed the characters one by one to the
2346 * protocol initialisation / selection function do_ssh_init().
2347 * When that returns 0, we're done with the initial greeting
2348 * exchange and can move on to packet discipline.
2351 int ret; /* need not be kept across crReturn */
2353 crReturnV; /* more data please */
2354 ret = do_ssh_init(ssh, *data);
2362 * We emerge from that loop when the initial negotiation is
2363 * over and we have selected an s_rdpkt function. Now pass
2364 * everything to s_rdpkt, and then pass the resulting packets
2365 * to the proper protocol handler.
2370 while (datalen > 0) {
2371 struct Packet *pktin = ssh->s_rdpkt(ssh, &data, &datalen);
2373 ssh->protocol(ssh, NULL, 0, pktin);
2374 ssh_free_packet(pktin);
2376 if (ssh->state == SSH_STATE_CLOSED)
2384 static int ssh_do_close(Ssh ssh, int notify_exit)
2387 struct ssh_channel *c;
2389 ssh->state = SSH_STATE_CLOSED;
2394 notify_remote_exit(ssh->frontend);
2399 * Now we must shut down any port and X forwardings going
2400 * through this connection.
2402 if (ssh->channels) {
2403 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2406 x11_close(c->u.x11.s);
2409 pfd_close(c->u.pfd.s);
2412 del234(ssh->channels, c);
2413 if (ssh->version == 2)
2414 bufchain_clear(&c->v.v2.outbuffer);
2422 static void ssh_log(Plug plug, int type, SockAddr addr, int port,
2423 const char *error_msg, int error_code)
2425 Ssh ssh = (Ssh) plug;
2426 char addrbuf[256], *msg;
2428 sk_getaddr(addr, addrbuf, lenof(addrbuf));
2431 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
2433 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
2438 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2441 Ssh ssh = (Ssh) plug;
2442 int need_notify = ssh_do_close(ssh, FALSE);
2444 if (!error_msg && !ssh->close_expected) {
2445 error_msg = "Server unexpectedly closed network connection";
2449 /* A socket error has occurred. */
2450 logevent(error_msg);
2451 connection_fatal(ssh->frontend, "%s", error_msg);
2453 logevent("Server closed network connection");
2456 notify_remote_exit(ssh->frontend);
2460 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2462 Ssh ssh = (Ssh) plug;
2463 ssh_gotdata(ssh, (unsigned char *)data, len);
2464 if (ssh->state == SSH_STATE_CLOSED) {
2465 ssh_do_close(ssh, TRUE);
2471 static void ssh_sent(Plug plug, int bufsize)
2473 Ssh ssh = (Ssh) plug;
2475 * If the send backlog on the SSH socket itself clears, we
2476 * should unthrottle the whole world if it was throttled.
2478 if (bufsize < SSH_MAX_BACKLOG)
2479 ssh_throttle_all(ssh, 0, bufsize);
2483 * Connect to specified host and port.
2484 * Returns an error message, or NULL on success.
2485 * Also places the canonical host name into `realhost'. It must be
2486 * freed by the caller.
2488 static const char *connect_to_host(Ssh ssh, char *host, int port,
2489 char **realhost, int nodelay, int keepalive)
2491 static const struct plug_function_table fn_table = {
2502 ssh->savedhost = snewn(1 + strlen(host), char);
2503 if (!ssh->savedhost)
2504 fatalbox("Out of memory");
2505 strcpy(ssh->savedhost, host);
2508 port = 22; /* default ssh port */
2509 ssh->savedport = port;
2514 logeventf(ssh, "Looking up host \"%s\"%s", host,
2515 (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
2516 (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
2517 addr = name_lookup(host, port, realhost, &ssh->cfg,
2518 ssh->cfg.addressfamily);
2519 if ((err = sk_addr_error(addr)) != NULL) {
2527 ssh->fn = &fn_table;
2528 ssh->s = new_connection(addr, *realhost, port,
2529 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
2530 if ((err = sk_socket_error(ssh->s)) != NULL) {
2532 notify_remote_exit(ssh->frontend);
2540 * Throttle or unthrottle the SSH connection.
2542 static void ssh1_throttle(Ssh ssh, int adjust)
2544 int old_count = ssh->v1_throttle_count;
2545 ssh->v1_throttle_count += adjust;
2546 assert(ssh->v1_throttle_count >= 0);
2547 if (ssh->v1_throttle_count && !old_count) {
2548 sk_set_frozen(ssh->s, 1);
2549 } else if (!ssh->v1_throttle_count && old_count) {
2550 sk_set_frozen(ssh->s, 0);
2555 * Throttle or unthrottle _all_ local data streams (for when sends
2556 * on the SSH connection itself back up).
2558 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2561 struct ssh_channel *c;
2563 if (enable == ssh->throttled_all)
2565 ssh->throttled_all = enable;
2566 ssh->overall_bufsize = bufsize;
2569 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2571 case CHAN_MAINSESSION:
2573 * This is treated separately, outside the switch.
2577 x11_override_throttle(c->u.x11.s, enable);
2580 /* Agent channels require no buffer management. */
2583 pfd_override_throttle(c->u.pfd.s, enable);
2590 * Username and password input, abstracted off into routines
2591 * reusable in several places - even between SSH1 and SSH2.
2594 /* Set up a username or password input loop on a given buffer. */
2595 static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2597 ssh->userpass_input_buffer = buffer;
2598 ssh->userpass_input_buflen = buflen;
2599 ssh->userpass_input_bufpos = 0;
2600 ssh->userpass_input_echo = echo;
2604 * Process some terminal data in the course of username/password
2605 * input. Returns >0 for success (line of input returned in
2606 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2607 * for inconclusive (keep waiting for more input please).
2609 static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2614 switch (c = *in++) {
2617 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2618 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2623 if (ssh->userpass_input_bufpos > 0) {
2624 if (ssh->userpass_input_echo)
2625 c_write_str(ssh, "\b \b");
2626 ssh->userpass_input_bufpos--;
2631 while (ssh->userpass_input_bufpos > 0) {
2632 if (ssh->userpass_input_echo)
2633 c_write_str(ssh, "\b \b");
2634 ssh->userpass_input_bufpos--;
2643 * This simplistic check for printability is disabled
2644 * when we're doing password input, because some people
2645 * have control characters in their passwords.o
2647 if ((!ssh->userpass_input_echo ||
2648 (c >= ' ' && c <= '~') ||
2649 ((unsigned char) c >= 160))
2650 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2651 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2652 if (ssh->userpass_input_echo)
2653 c_write(ssh, &c, 1);
2661 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
2663 Ssh ssh = (Ssh) sshv;
2665 ssh->agent_response = reply;
2666 ssh->agent_response_len = replylen;
2668 if (ssh->version == 1)
2669 do_ssh1_login(ssh, NULL, -1, NULL);
2671 do_ssh2_authconn(ssh, NULL, -1, NULL);
2674 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
2676 struct ssh_channel *c = (struct ssh_channel *)cv;
2678 void *sentreply = reply;
2681 /* Fake SSH_AGENT_FAILURE. */
2682 sentreply = "\0\0\0\1\5";
2685 if (ssh->version == 2) {
2686 ssh2_add_channel_data(c, sentreply, replylen);
2689 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2690 PKT_INT, c->remoteid,
2693 PKT_DATA, sentreply, replylen,
2702 * Handle the key exchange and user authentication phases.
2704 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2705 struct Packet *pktin)
2708 unsigned char cookie[8], *ptr;
2709 struct RSAKey servkey, hostkey;
2710 struct MD5Context md5c;
2711 struct do_ssh1_login_state {
2713 unsigned char *rsabuf, *keystr1, *keystr2;
2714 unsigned long supported_ciphers_mask, supported_auths_mask;
2715 int tried_publickey, tried_agent;
2716 int tis_auth_refused, ccard_auth_refused;
2717 unsigned char session_id[16];
2720 void *publickey_blob;
2721 int publickey_bloblen;
2727 unsigned char request[5], *response, *p;
2736 crState(do_ssh1_login_state);
2738 crBegin(ssh->do_ssh1_login_crstate);
2743 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
2744 bombout(("Public key packet not received"));
2748 logevent("Received public keys");
2750 ptr = ssh_pkt_getdata(pktin, 8);
2752 bombout(("SSH1 public key packet stopped before random cookie"));
2755 memcpy(cookie, ptr, 8);
2757 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2758 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
2759 bombout(("Failed to read SSH1 public keys from public key packet"));
2764 * Log the host key fingerprint.
2768 logevent("Host key fingerprint is:");
2769 strcpy(logmsg, " ");
2770 hostkey.comment = NULL;
2771 rsa_fingerprint(logmsg + strlen(logmsg),
2772 sizeof(logmsg) - strlen(logmsg), &hostkey);
2776 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2777 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2778 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
2780 ssh->v1_local_protoflags =
2781 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2782 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2785 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2786 MD5Update(&md5c, s->keystr1, servkey.bytes);
2787 MD5Update(&md5c, cookie, 8);
2788 MD5Final(s->session_id, &md5c);
2790 for (i = 0; i < 32; i++)
2791 ssh->session_key[i] = random_byte();
2794 * Verify that the `bits' and `bytes' parameters match.
2796 if (hostkey.bits > hostkey.bytes * 8 ||
2797 servkey.bits > servkey.bytes * 8) {
2798 bombout(("SSH1 public keys were badly formatted"));
2802 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2804 s->rsabuf = snewn(s->len, unsigned char);
2806 fatalbox("Out of memory");
2809 * Verify the host key.
2813 * First format the key into a string.
2815 int len = rsastr_len(&hostkey);
2816 char fingerprint[100];
2817 char *keystr = snewn(len, char);
2819 fatalbox("Out of memory");
2820 rsastr_fmt(keystr, &hostkey);
2821 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2822 verify_ssh_host_key(ssh->frontend,
2823 ssh->savedhost, ssh->savedport, "rsa", keystr,
2828 for (i = 0; i < 32; i++) {
2829 s->rsabuf[i] = ssh->session_key[i];
2831 s->rsabuf[i] ^= s->session_id[i];
2834 if (hostkey.bytes > servkey.bytes) {
2835 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2837 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2839 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
2841 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2844 bombout(("SSH1 public key encryptions failed due to bad formatting"));
2848 logevent("Encrypted session key");
2851 int cipher_chosen = 0, warn = 0;
2852 char *cipher_string = NULL;
2854 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2855 int next_cipher = ssh->cfg.ssh_cipherlist[i];
2856 if (next_cipher == CIPHER_WARN) {
2857 /* If/when we choose a cipher, warn about it */
2859 } else if (next_cipher == CIPHER_AES) {
2860 /* XXX Probably don't need to mention this. */
2861 logevent("AES not supported in SSH1, skipping");
2863 switch (next_cipher) {
2864 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
2865 cipher_string = "3DES"; break;
2866 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
2867 cipher_string = "Blowfish"; break;
2868 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
2869 cipher_string = "single-DES"; break;
2871 if (s->supported_ciphers_mask & (1 << s->cipher_type))
2875 if (!cipher_chosen) {
2876 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2877 bombout(("Server violates SSH 1 protocol by not "
2878 "supporting 3DES encryption"));
2880 /* shouldn't happen */
2881 bombout(("No supported ciphers found"));
2885 /* Warn about chosen cipher if necessary. */
2887 sk_set_frozen(ssh->s, 1);
2888 askalg(ssh->frontend, "cipher", cipher_string);
2889 sk_set_frozen(ssh->s, 0);
2893 switch (s->cipher_type) {
2894 case SSH_CIPHER_3DES:
2895 logevent("Using 3DES encryption");
2897 case SSH_CIPHER_DES:
2898 logevent("Using single-DES encryption");
2900 case SSH_CIPHER_BLOWFISH:
2901 logevent("Using Blowfish encryption");
2905 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2906 PKT_CHAR, s->cipher_type,
2907 PKT_DATA, cookie, 8,
2908 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2909 PKT_DATA, s->rsabuf, s->len,
2910 PKT_INT, ssh->v1_local_protoflags, PKT_END);
2912 logevent("Trying to enable encryption...");
2916 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2917 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2919 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2920 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
2921 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
2923 ssh->crcda_ctx = crcda_make_context();
2924 logevent("Installing CRC compensation attack detector");
2926 if (servkey.modulus) {
2927 sfree(servkey.modulus);
2928 servkey.modulus = NULL;
2930 if (servkey.exponent) {
2931 sfree(servkey.exponent);
2932 servkey.exponent = NULL;
2934 if (hostkey.modulus) {
2935 sfree(hostkey.modulus);
2936 hostkey.modulus = NULL;
2938 if (hostkey.exponent) {
2939 sfree(hostkey.exponent);
2940 hostkey.exponent = NULL;
2944 if (pktin->type != SSH1_SMSG_SUCCESS) {
2945 bombout(("Encryption not successfully enabled"));
2949 logevent("Successfully started encryption");
2953 if (!*ssh->cfg.username) {
2954 if (ssh_get_line && !ssh_getline_pw_only) {
2955 if (!ssh_get_line("login as: ",
2956 s->username, sizeof(s->username), FALSE)) {
2958 * get_line failed to get a username.
2961 logevent("No username provided. Abandoning session.");
2962 ssh->close_expected = TRUE;
2963 ssh_closing((Plug)ssh, NULL, 0, 0);
2967 int ret; /* need not be kept over crReturn */
2968 c_write_str(ssh, "login as: ");
2971 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
2973 crWaitUntil(!pktin);
2974 ret = process_userpass_input(ssh, in, inlen);
2978 c_write_str(ssh, "\r\n");
2981 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
2982 s->username[sizeof(s->username)-1] = '\0';
2985 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
2987 char userlog[22 + sizeof(s->username)];
2988 sprintf(userlog, "Sent username \"%s\"", s->username);
2990 if (flags & FLAG_INTERACTIVE &&
2991 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2992 strcat(userlog, "\r\n");
2993 c_write_str(ssh, userlog);
3000 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
3001 /* We must not attempt PK auth. Pretend we've already tried it. */
3002 s->tried_publickey = s->tried_agent = 1;
3004 s->tried_publickey = s->tried_agent = 0;
3006 s->tis_auth_refused = s->ccard_auth_refused = 0;
3007 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
3008 if (!filename_is_null(ssh->cfg.keyfile)) {
3009 if (!rsakey_pubblob(&ssh->cfg.keyfile,
3010 &s->publickey_blob, &s->publickey_bloblen, NULL))
3011 s->publickey_blob = NULL;
3013 s->publickey_blob = NULL;
3015 while (pktin->type == SSH1_SMSG_FAILURE) {
3016 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
3018 if (agent_exists() && !s->tried_agent) {
3020 * Attempt RSA authentication using Pageant.
3026 logevent("Pageant is running. Requesting keys.");
3028 /* Request the keys held by the agent. */
3029 PUT_32BIT(s->request, 1);
3030 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
3031 if (!agent_query(s->request, 5, &r, &s->responselen,
3032 ssh_agent_callback, ssh)) {
3036 bombout(("Unexpected data from server while waiting"
3037 " for agent response"));
3040 } while (pktin || inlen > 0);
3041 r = ssh->agent_response;
3042 s->responselen = ssh->agent_response_len;
3044 s->response = (unsigned char *) r;
3045 if (s->response && s->responselen >= 5 &&
3046 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3047 s->p = s->response + 5;
3048 s->nkeys = GET_32BIT(s->p);
3052 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
3055 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
3058 sprintf(buf, "Trying Pageant key #%d", s->keyi);
3061 if (s->publickey_blob &&
3062 !memcmp(s->p, s->publickey_blob,
3063 s->publickey_bloblen)) {
3064 logevent("This key matches configured key file");
3065 s->tried_publickey = 1;
3070 do { /* do while (0) to make breaking easy */
3071 n = ssh1_read_bignum
3072 (s->p, s->responselen-(s->p-s->response),
3077 n = ssh1_read_bignum
3078 (s->p, s->responselen-(s->p-s->response),
3083 if (s->responselen - (s->p-s->response) < 4)
3085 s->commentlen = GET_32BIT(s->p);
3087 if (s->responselen - (s->p-s->response) <
3090 s->commentp = (char *)s->p;
3091 s->p += s->commentlen;
3095 logevent("Pageant key list packet was truncated");
3099 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3100 PKT_BIGNUM, s->key.modulus, PKT_END);
3102 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3103 logevent("Key refused");
3106 logevent("Received RSA challenge");
3107 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3108 bombout(("Server's RSA challenge was badly formatted"));
3113 char *agentreq, *q, *ret;
3116 len = 1 + 4; /* message type, bit count */
3117 len += ssh1_bignum_length(s->key.exponent);
3118 len += ssh1_bignum_length(s->key.modulus);
3119 len += ssh1_bignum_length(s->challenge);
3120 len += 16; /* session id */
3121 len += 4; /* response format */
3122 agentreq = snewn(4 + len, char);
3123 PUT_32BIT(agentreq, len);
3125 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
3126 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
3128 q += ssh1_write_bignum(q, s->key.exponent);
3129 q += ssh1_write_bignum(q, s->key.modulus);
3130 q += ssh1_write_bignum(q, s->challenge);
3131 memcpy(q, s->session_id, 16);
3133 PUT_32BIT(q, 1); /* response format */
3134 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3135 ssh_agent_callback, ssh)) {
3140 bombout(("Unexpected data from server"
3141 " while waiting for agent"
3145 } while (pktin || inlen > 0);
3146 vret = ssh->agent_response;
3147 retlen = ssh->agent_response_len;
3152 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3153 logevent("Sending Pageant's response");
3154 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3155 PKT_DATA, ret + 5, 16,
3159 if (pktin->type == SSH1_SMSG_SUCCESS) {
3161 ("Pageant's response accepted");
3162 if (flags & FLAG_VERBOSE) {
3163 c_write_str(ssh, "Authenticated using"
3165 c_write(ssh, s->commentp,
3167 c_write_str(ssh, "\" from agent\r\n");
3172 ("Pageant's response not accepted");
3175 ("Pageant failed to answer challenge");
3179 logevent("No reply received from Pageant");
3182 freebn(s->key.exponent);
3183 freebn(s->key.modulus);
3184 freebn(s->challenge);
3193 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
3194 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
3196 if (ssh->cfg.try_tis_auth &&
3197 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3198 !s->tis_auth_refused) {
3199 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
3200 logevent("Requested TIS authentication");
3201 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
3203 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
3204 logevent("TIS authentication declined");
3205 if (flags & FLAG_INTERACTIVE)
3206 c_write_str(ssh, "TIS authentication refused.\r\n");
3207 s->tis_auth_refused = 1;
3213 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3215 bombout(("TIS challenge packet was badly formed"));
3218 logevent("Received TIS challenge");
3219 if (challengelen > sizeof(s->prompt) - 1)
3220 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3221 memcpy(s->prompt, challenge, challengelen);
3222 /* Prompt heuristic comes from OpenSSH */
3223 strncpy(s->prompt + challengelen,
3224 memchr(s->prompt, '\n', challengelen) ?
3225 "": "\r\nResponse: ",
3226 (sizeof s->prompt) - challengelen);
3227 s->prompt[(sizeof s->prompt) - 1] = '\0';
3230 if (ssh->cfg.try_tis_auth &&
3231 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3232 !s->ccard_auth_refused) {
3233 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
3234 logevent("Requested CryptoCard authentication");
3235 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
3237 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
3238 logevent("CryptoCard authentication declined");
3239 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3240 s->ccard_auth_refused = 1;
3246 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3248 bombout(("CryptoCard challenge packet was badly formed"));
3251 logevent("Received CryptoCard challenge");
3252 if (challengelen > sizeof(s->prompt) - 1)
3253 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3254 memcpy(s->prompt, challenge, challengelen);
3255 strncpy(s->prompt + challengelen,
3256 memchr(s->prompt, '\n', challengelen) ?
3257 "" : "\r\nResponse: ",
3258 sizeof(s->prompt) - challengelen);
3259 s->prompt[sizeof(s->prompt) - 1] = '\0';
3262 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3263 sprintf(s->prompt, "%.90s@%.90s's password: ",
3264 s->username, ssh->savedhost);
3266 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3267 char *comment = NULL;
3270 if (flags & FLAG_VERBOSE)
3271 c_write_str(ssh, "Trying public key authentication.\r\n");
3272 logeventf(ssh, "Trying public key \"%s\"",
3273 filename_to_str(&ssh->cfg.keyfile));
3274 type = key_type(&ssh->cfg.keyfile);
3275 if (type != SSH_KEYTYPE_SSH1) {
3276 sprintf(msgbuf, "Key is of wrong type (%s)",
3277 key_type_to_str(type));
3279 c_write_str(ssh, msgbuf);
3280 c_write_str(ssh, "\r\n");
3281 s->tried_publickey = 1;
3284 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
3285 if (flags & FLAG_VERBOSE)
3286 c_write_str(ssh, "No passphrase required.\r\n");
3289 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
3294 * Show password prompt, having first obtained it via a TIS
3295 * or CryptoCard exchange if we're doing TIS or CryptoCard
3299 if (!ssh_get_line(s->prompt, s->password,
3300 sizeof(s->password), TRUE)) {
3302 * get_line failed to get a password (for example
3303 * because one was supplied on the command line
3304 * which has already failed to work). Terminate.
3306 send_packet(ssh, SSH1_MSG_DISCONNECT,
3307 PKT_STR, "No more passwords available to try",
3309 logevent("Unable to authenticate");
3310 connection_fatal(ssh->frontend, "Unable to authenticate");
3311 ssh->close_expected = TRUE;
3312 ssh_closing((Plug)ssh, NULL, 0, 0);
3316 /* Prompt may have come from server. We've munged it a bit, so
3317 * we know it to be zero-terminated at least once. */
3318 int ret; /* need not be saved over crReturn */
3319 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3322 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
3324 crWaitUntil(!pktin);
3325 ret = process_userpass_input(ssh, in, inlen);
3329 c_write_str(ssh, "\r\n");
3333 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3335 * Try public key authentication with the specified
3338 s->tried_publickey = 1;
3341 const char *error = NULL;
3342 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3345 c_write_str(ssh, "Couldn't load private key from ");
3346 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
3347 c_write_str(ssh, " (");
3348 c_write_str(ssh, error);
3349 c_write_str(ssh, ").\r\n");
3350 continue; /* go and try password */
3353 c_write_str(ssh, "Wrong passphrase.\r\n");
3354 s->tried_publickey = 0;
3355 continue; /* try again */
3360 * Send a public key attempt.
3362 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3363 PKT_BIGNUM, s->key.modulus, PKT_END);
3366 if (pktin->type == SSH1_SMSG_FAILURE) {
3367 c_write_str(ssh, "Server refused our public key.\r\n");
3368 continue; /* go and try password */
3370 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3371 bombout(("Bizarre response to offer of public key"));
3377 unsigned char buffer[32];
3378 Bignum challenge, response;
3380 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3381 bombout(("Server's RSA challenge was badly formatted"));
3384 response = rsadecrypt(challenge, &s->key);
3385 freebn(s->key.private_exponent);/* burn the evidence */
3387 for (i = 0; i < 32; i++) {
3388 buffer[i] = bignum_byte(response, 31 - i);
3392 MD5Update(&md5c, buffer, 32);
3393 MD5Update(&md5c, s->session_id, 16);
3394 MD5Final(buffer, &md5c);
3396 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3397 PKT_DATA, buffer, 16, PKT_END);
3404 if (pktin->type == SSH1_SMSG_FAILURE) {
3405 if (flags & FLAG_VERBOSE)
3406 c_write_str(ssh, "Failed to authenticate with"
3407 " our public key.\r\n");
3408 continue; /* go and try password */
3409 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3410 bombout(("Bizarre response to RSA authentication response"));
3414 break; /* we're through! */
3416 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3418 * Defence against traffic analysis: we send a
3419 * whole bunch of packets containing strings of
3420 * different lengths. One of these strings is the
3421 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3422 * The others are all random data in
3423 * SSH1_MSG_IGNORE packets. This way a passive
3424 * listener can't tell which is the password, and
3425 * hence can't deduce the password length.
3427 * Anybody with a password length greater than 16
3428 * bytes is going to have enough entropy in their
3429 * password that a listener won't find it _that_
3430 * much help to know how long it is. So what we'll
3433 * - if password length < 16, we send 15 packets
3434 * containing string lengths 1 through 15
3436 * - otherwise, we let N be the nearest multiple
3437 * of 8 below the password length, and send 8
3438 * packets containing string lengths N through
3439 * N+7. This won't obscure the order of
3440 * magnitude of the password length, but it will
3441 * introduce a bit of extra uncertainty.
3443 * A few servers (the old 1.2.18 through 1.2.22)
3444 * can't deal with SSH1_MSG_IGNORE. For these
3445 * servers, we need an alternative defence. We make
3446 * use of the fact that the password is interpreted
3447 * as a C string: so we can append a NUL, then some
3450 * One server (a Cisco one) can deal with neither
3451 * SSH1_MSG_IGNORE _nor_ a padded password string.
3452 * For this server we are left with no defences
3453 * against password length sniffing.
3455 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
3457 * The server can deal with SSH1_MSG_IGNORE, so
3458 * we can use the primary defence.
3460 int bottom, top, pwlen, i;
3463 pwlen = strlen(s->password);
3465 bottom = 0; /* zero length passwords are OK! :-) */
3468 bottom = pwlen & ~7;
3472 assert(pwlen >= bottom && pwlen <= top);
3474 randomstr = snewn(top + 1, char);
3476 for (i = bottom; i <= top; i++) {
3478 defer_packet(ssh, s->pwpkt_type,
3479 PKTT_PASSWORD, PKT_STR, s->password,
3480 PKTT_OTHER, PKT_END);
3482 for (j = 0; j < i; j++) {
3484 randomstr[j] = random_byte();
3485 } while (randomstr[j] == '\0');
3487 randomstr[i] = '\0';
3488 defer_packet(ssh, SSH1_MSG_IGNORE,
3489 PKT_STR, randomstr, PKT_END);
3492 logevent("Sending password with camouflage packets");
3493 ssh_pkt_defersend(ssh);
3496 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3498 * The server can't deal with SSH1_MSG_IGNORE
3499 * but can deal with padded passwords, so we
3500 * can use the secondary defence.
3506 len = strlen(s->password);
3507 if (len < sizeof(string)) {
3509 strcpy(string, s->password);
3510 len++; /* cover the zero byte */
3511 while (len < sizeof(string)) {
3512 string[len++] = (char) random_byte();
3517 logevent("Sending length-padded password");
3518 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3519 PKT_INT, len, PKT_DATA, ss, len,
3520 PKTT_OTHER, PKT_END);
3523 * The server has _both_
3524 * BUG_CHOKES_ON_SSH1_IGNORE and
3525 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3526 * therefore nothing we can do.
3529 len = strlen(s->password);
3530 logevent("Sending unpadded password");
3531 send_packet(ssh, s->pwpkt_type,
3532 PKTT_PASSWORD, PKT_INT, len,
3533 PKT_DATA, s->password, len,
3534 PKTT_OTHER, PKT_END);
3537 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3538 PKT_STR, s->password, PKTT_OTHER, PKT_END);
3541 logevent("Sent password");
3542 memset(s->password, 0, strlen(s->password));
3544 if (pktin->type == SSH1_SMSG_FAILURE) {
3545 if (flags & FLAG_VERBOSE)
3546 c_write_str(ssh, "Access denied\r\n");
3547 logevent("Authentication refused");
3548 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3549 bombout(("Strange packet received, type %d", pktin->type));
3554 logevent("Authentication successful");
3559 void sshfwd_close(struct ssh_channel *c)
3563 if (ssh->state != SSH_STATE_SESSION) {
3564 assert(ssh->state == SSH_STATE_CLOSED);
3568 if (c && !c->closes) {
3570 * If halfopen is true, we have sent
3571 * CHANNEL_OPEN for this channel, but it hasn't even been
3572 * acknowledged by the server. So we must set a close flag
3573 * on it now, and then when the server acks the channel
3574 * open, we can close it then.
3577 if (ssh->version == 1) {
3578 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3581 struct Packet *pktout;
3582 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3583 ssh2_pkt_adduint32(pktout, c->remoteid);
3584 ssh2_pkt_send(ssh, pktout);
3587 c->closes = 1; /* sent MSG_CLOSE */
3588 if (c->type == CHAN_X11) {
3590 logevent("Forwarded X11 connection terminated");
3591 } else if (c->type == CHAN_SOCKDATA ||
3592 c->type == CHAN_SOCKDATA_DORMANT) {
3594 logevent("Forwarded port closed");
3599 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3603 if (ssh->state != SSH_STATE_SESSION) {
3604 assert(ssh->state == SSH_STATE_CLOSED);
3608 if (ssh->version == 1) {
3609 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3610 PKT_INT, c->remoteid,
3612 PKT_INT, len, PKT_DATA, buf, len,
3613 PKTT_OTHER, PKT_END);
3615 * In SSH1 we can return 0 here - implying that forwarded
3616 * connections are never individually throttled - because
3617 * the only circumstance that can cause throttling will be
3618 * the whole SSH connection backing up, in which case
3619 * _everything_ will be throttled as a whole.
3623 ssh2_add_channel_data(c, buf, len);
3624 return ssh2_try_send(c);
3628 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3632 if (ssh->state != SSH_STATE_SESSION) {
3633 assert(ssh->state == SSH_STATE_CLOSED);
3637 if (ssh->version == 1) {
3638 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3639 c->v.v1.throttling = 0;
3640 ssh1_throttle(ssh, -1);
3643 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3647 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
3649 struct queued_handler *qh = ssh->qhead;
3653 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
3656 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
3657 ssh->packet_dispatch[qh->msg1] = NULL;
3660 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
3661 ssh->packet_dispatch[qh->msg2] = NULL;
3665 ssh->qhead = qh->next;
3667 if (ssh->qhead->msg1 > 0) {
3668 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
3669 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
3671 if (ssh->qhead->msg2 > 0) {
3672 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
3673 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
3676 ssh->qhead = ssh->qtail = NULL;
3677 ssh->packet_dispatch[pktin->type] = NULL;
3680 qh->handler(ssh, pktin, qh->ctx);
3685 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
3686 chandler_fn_t handler, void *ctx)
3688 struct queued_handler *qh;
3690 qh = snew(struct queued_handler);
3693 qh->handler = handler;
3697 if (ssh->qtail == NULL) {
3701 assert(ssh->packet_dispatch[qh->msg1] == NULL);
3702 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
3705 assert(ssh->packet_dispatch[qh->msg2] == NULL);
3706 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
3709 ssh->qtail->next = qh;
3714 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
3716 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
3718 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
3719 SSH2_MSG_REQUEST_SUCCESS)) {
3720 logeventf(ssh, "Remote port forwarding from %s enabled",
3723 logeventf(ssh, "Remote port forwarding from %s refused",
3726 rpf = del234(ssh->rportfwds, pf);
3732 static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
3734 const char *portfwd_strptr = cfg->portfwd;
3735 struct ssh_portfwd *epf;
3738 if (!ssh->portfwds) {
3739 ssh->portfwds = newtree234(ssh_portcmp);
3742 * Go through the existing port forwardings and tag them
3743 * with status==DESTROY. Any that we want to keep will be
3744 * re-enabled (status==KEEP) as we go through the
3745 * configuration and find out which bits are the same as
3748 struct ssh_portfwd *epf;
3750 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3751 epf->status = DESTROY;
3754 while (*portfwd_strptr) {
3755 char address_family, type;
3756 int sport,dport,sserv,dserv;
3757 char sports[256], dports[256], saddr[256], host[256];
3760 address_family = 'A';
3762 if (*portfwd_strptr == 'A' ||
3763 *portfwd_strptr == '4' ||
3764 *portfwd_strptr == '6')
3765 address_family = *portfwd_strptr++;
3766 if (*portfwd_strptr == 'L' ||
3767 *portfwd_strptr == 'R' ||
3768 *portfwd_strptr == 'D')
3769 type = *portfwd_strptr++;
3774 while (*portfwd_strptr && *portfwd_strptr != '\t') {
3775 if (*portfwd_strptr == ':') {
3777 * We've seen a colon in the middle of the
3778 * source port number. This means that
3779 * everything we've seen until now is the
3780 * source _address_, so we'll move it into
3781 * saddr and start sports from the beginning
3786 if (ssh->version == 1 && type == 'R') {
3787 logeventf(ssh, "SSH1 cannot handle remote source address "
3788 "spec \"%s\"; ignoring", sports);
3790 strcpy(saddr, sports);
3793 if (n < 255) sports[n++] = *portfwd_strptr++;
3797 if (*portfwd_strptr == '\t')
3800 while (*portfwd_strptr && *portfwd_strptr != ':') {
3801 if (n < 255) host[n++] = *portfwd_strptr++;
3804 if (*portfwd_strptr == ':')
3807 while (*portfwd_strptr) {
3808 if (n < 255) dports[n++] = *portfwd_strptr++;
3812 dport = atoi(dports);
3816 dport = net_service_lookup(dports);
3818 logeventf(ssh, "Service lookup failed for destination"
3819 " port \"%s\"", dports);
3823 while (*portfwd_strptr) portfwd_strptr++;
3825 portfwd_strptr++; /* eat the NUL and move to next one */
3827 sport = atoi(sports);
3831 sport = net_service_lookup(sports);
3833 logeventf(ssh, "Service lookup failed for source"
3834 " port \"%s\"", sports);
3837 if (sport && dport) {
3838 /* Set up a description of the source port. */
3839 struct ssh_portfwd *pfrec, *epfrec;
3841 pfrec = snew(struct ssh_portfwd);
3843 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
3844 pfrec->sserv = sserv ? dupstr(sports) : NULL;
3845 pfrec->sport = sport;
3846 pfrec->daddr = *host ? dupstr(host) : NULL;
3847 pfrec->dserv = dserv ? dupstr(dports) : NULL;
3848 pfrec->dport = dport;
3849 pfrec->local = NULL;
3850 pfrec->remote = NULL;
3851 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
3852 address_family == '6' ? ADDRTYPE_IPV6 :
3855 epfrec = add234(ssh->portfwds, pfrec);
3856 if (epfrec != pfrec) {
3858 * We already have a port forwarding with precisely
3859 * these parameters. Hence, no need to do anything;
3860 * simply tag the existing one as KEEP.
3862 epfrec->status = KEEP;
3863 free_portfwd(pfrec);
3865 pfrec->status = CREATE;
3871 * Now go through and destroy any port forwardings which were
3874 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3875 if (epf->status == DESTROY) {
3878 message = dupprintf("%s port forwarding from %s%s%d",
3879 epf->type == 'L' ? "local" :
3880 epf->type == 'R' ? "remote" : "dynamic",
3881 epf->saddr ? epf->saddr : "",
3882 epf->saddr ? ":" : "",
3885 if (epf->type != 'D') {
3886 char *msg2 = dupprintf("%s to %s:%d", message,
3887 epf->daddr, epf->dport);
3892 logeventf(ssh, "Cancelling %s", message);
3896 struct ssh_rportfwd *rpf = epf->remote;
3897 struct Packet *pktout;
3900 * Cancel the port forwarding at the server
3903 if (ssh->version == 1) {
3905 * We cannot cancel listening ports on the
3906 * server side in SSH1! There's no message
3907 * to support it. Instead, we simply remove
3908 * the rportfwd record from the local end
3909 * so that any connections the server tries
3910 * to make on it are rejected.
3913 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
3914 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
3915 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
3917 ssh2_pkt_addstring(pktout, epf->saddr);
3918 } else if (ssh->cfg.rport_acceptall) {
3919 ssh2_pkt_addstring(pktout, "0.0.0.0");
3921 ssh2_pkt_addstring(pktout, "127.0.0.1");
3923 ssh2_pkt_adduint32(pktout, epf->sport);
3924 ssh2_pkt_send(ssh, pktout);
3927 del234(ssh->rportfwds, rpf);
3929 } else if (epf->local) {
3930 pfd_terminate(epf->local);
3933 delpos234(ssh->portfwds, i);
3935 i--; /* so we don't skip one in the list */
3939 * And finally, set up any new port forwardings (status==CREATE).
3941 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3942 if (epf->status == CREATE) {
3943 char *sportdesc, *dportdesc;
3944 sportdesc = dupprintf("%s%s%s%s%d%s",
3945 epf->saddr ? epf->saddr : "",
3946 epf->saddr ? ":" : "",
3947 epf->sserv ? epf->sserv : "",
3948 epf->sserv ? "(" : "",
3950 epf->sserv ? ")" : "");
3951 if (epf->type == 'D') {
3954 dportdesc = dupprintf("%s:%s%s%d%s",
3956 epf->dserv ? epf->dserv : "",
3957 epf->dserv ? "(" : "",
3959 epf->dserv ? ")" : "");
3962 if (epf->type == 'L') {
3963 const char *err = pfd_addforward(epf->daddr, epf->dport,
3964 epf->saddr, epf->sport,
3967 epf->addressfamily);
3969 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
3970 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
3971 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
3972 sportdesc, dportdesc,
3973 err ? " failed: " : "", err ? err : "");
3974 } else if (epf->type == 'D') {
3975 const char *err = pfd_addforward(NULL, -1,
3976 epf->saddr, epf->sport,
3979 epf->addressfamily);
3981 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
3982 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
3983 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
3985 err ? " failed: " : "", err ? err : "");
3987 struct ssh_rportfwd *pf;
3990 * Ensure the remote port forwardings tree exists.
3992 if (!ssh->rportfwds) {
3993 if (ssh->version == 1)
3994 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3996 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
3999 pf = snew(struct ssh_rportfwd);
4000 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
4001 pf->dhost[lenof(pf->dhost)-1] = '\0';
4002 pf->dport = epf->dport;
4003 pf->sport = epf->sport;
4004 if (add234(ssh->rportfwds, pf) != pf) {
4005 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
4006 epf->daddr, epf->dport);
4009 logeventf(ssh, "Requesting remote port %s"
4010 " forward to %s", sportdesc, dportdesc);
4012 pf->sportdesc = sportdesc;
4017 if (ssh->version == 1) {
4018 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
4019 PKT_INT, epf->sport,
4020 PKT_STR, epf->daddr,
4021 PKT_INT, epf->dport,
4023 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4025 ssh_rportfwd_succfail, pf);
4027 struct Packet *pktout;
4028 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4029 ssh2_pkt_addstring(pktout, "tcpip-forward");
4030 ssh2_pkt_addbool(pktout, 1);/* want reply */
4032 ssh2_pkt_addstring(pktout, epf->saddr);
4033 } else if (ssh->cfg.rport_acceptall) {
4034 ssh2_pkt_addstring(pktout, "0.0.0.0");
4036 ssh2_pkt_addstring(pktout, "127.0.0.1");
4038 ssh2_pkt_adduint32(pktout, epf->sport);
4039 ssh2_pkt_send(ssh, pktout);
4041 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4042 SSH2_MSG_REQUEST_FAILURE,
4043 ssh_rportfwd_succfail, pf);
4052 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4055 int stringlen, bufsize;
4057 ssh_pkt_getstring(pktin, &string, &stringlen);
4058 if (string == NULL) {
4059 bombout(("Incoming terminal data packet was badly formed"));
4063 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4065 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4066 ssh->v1_stdout_throttling = 1;
4067 ssh1_throttle(ssh, +1);
4071 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4073 /* Remote side is trying to open a channel to talk to our
4074 * X-Server. Give them back a local channel number. */
4075 struct ssh_channel *c;
4076 int remoteid = ssh_pkt_getuint32(pktin);
4078 logevent("Received X11 connect request");
4079 /* Refuse if X11 forwarding is disabled. */
4080 if (!ssh->X11_fwd_enabled) {
4081 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4082 PKT_INT, remoteid, PKT_END);
4083 logevent("Rejected X11 connect request");
4085 c = snew(struct ssh_channel);
4088 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
4089 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
4090 logevent("Opening X11 forward connection failed");
4092 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4093 PKT_INT, remoteid, PKT_END);
4096 ("Opening X11 forward connection succeeded");
4097 c->remoteid = remoteid;
4098 c->halfopen = FALSE;
4099 c->localid = alloc_channel_id(ssh);
4101 c->v.v1.throttling = 0;
4102 c->type = CHAN_X11; /* identify channel type */
4103 add234(ssh->channels, c);
4104 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4105 PKT_INT, c->remoteid, PKT_INT,
4106 c->localid, PKT_END);
4107 logevent("Opened X11 forward channel");
4112 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4114 /* Remote side is trying to open a channel to talk to our
4115 * agent. Give them back a local channel number. */
4116 struct ssh_channel *c;
4117 int remoteid = ssh_pkt_getuint32(pktin);
4119 /* Refuse if agent forwarding is disabled. */
4120 if (!ssh->agentfwd_enabled) {
4121 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4122 PKT_INT, remoteid, PKT_END);
4124 c = snew(struct ssh_channel);
4126 c->remoteid = remoteid;
4127 c->halfopen = FALSE;
4128 c->localid = alloc_channel_id(ssh);
4130 c->v.v1.throttling = 0;
4131 c->type = CHAN_AGENT; /* identify channel type */
4132 c->u.a.lensofar = 0;
4133 add234(ssh->channels, c);
4134 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4135 PKT_INT, c->remoteid, PKT_INT, c->localid,
4140 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4142 /* Remote side is trying to open a channel to talk to a
4143 * forwarded port. Give them back a local channel number. */
4144 struct ssh_channel *c;
4145 struct ssh_rportfwd pf, *pfp;
4148 char *host, buf[1024];
4150 c = snew(struct ssh_channel);
4153 remoteid = ssh_pkt_getuint32(pktin);
4154 ssh_pkt_getstring(pktin, &host, &hostsize);
4155 port = ssh_pkt_getuint32(pktin);
4157 if (hostsize >= lenof(pf.dhost))
4158 hostsize = lenof(pf.dhost)-1;
4159 memcpy(pf.dhost, host, hostsize);
4160 pf.dhost[hostsize] = '\0';
4162 pfp = find234(ssh->rportfwds, &pf, NULL);
4165 sprintf(buf, "Rejected remote port open request for %s:%d",
4168 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4169 PKT_INT, remoteid, PKT_END);
4171 sprintf(buf, "Received remote port open request for %s:%d",
4174 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
4175 c, &ssh->cfg, pfp->pfrec->addressfamily);
4178 sprintf(buf, "Port open failed: %s", e);
4181 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4182 PKT_INT, remoteid, PKT_END);
4184 c->remoteid = remoteid;
4185 c->halfopen = FALSE;
4186 c->localid = alloc_channel_id(ssh);
4188 c->v.v1.throttling = 0;
4189 c->type = CHAN_SOCKDATA; /* identify channel type */
4190 add234(ssh->channels, c);
4191 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4192 PKT_INT, c->remoteid, PKT_INT,
4193 c->localid, PKT_END);
4194 logevent("Forwarded port opened successfully");
4199 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4201 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4202 unsigned int localid = ssh_pkt_getuint32(pktin);
4203 struct ssh_channel *c;
4205 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4206 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4207 c->remoteid = localid;
4208 c->halfopen = FALSE;
4209 c->type = CHAN_SOCKDATA;
4210 c->v.v1.throttling = 0;
4211 pfd_confirm(c->u.pfd.s);
4214 if (c && c->closes) {
4216 * We have a pending close on this channel,
4217 * which we decided on before the server acked
4218 * the channel open. So now we know the
4219 * remoteid, we can close it again.
4221 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4222 PKT_INT, c->remoteid, PKT_END);
4226 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4228 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4229 struct ssh_channel *c;
4231 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4232 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4233 logevent("Forwarded connection refused by server");
4234 pfd_close(c->u.pfd.s);
4235 del234(ssh->channels, c);
4240 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4242 /* Remote side closes a channel. */
4243 unsigned i = ssh_pkt_getuint32(pktin);
4244 struct ssh_channel *c;
4245 c = find234(ssh->channels, &i, ssh_channelfind);
4246 if (c && !c->halfopen) {
4249 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4251 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4252 logevent("Forwarded X11 connection terminated");
4253 assert(c->u.x11.s != NULL);
4254 x11_close(c->u.x11.s);
4257 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4258 logevent("Forwarded port closed");
4259 assert(c->u.pfd.s != NULL);
4260 pfd_close(c->u.pfd.s);
4264 c->closes |= (closetype << 2); /* seen this message */
4265 if (!(c->closes & closetype)) {
4266 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4268 c->closes |= closetype; /* sent it too */
4271 if (c->closes == 15) {
4272 del234(ssh->channels, c);
4276 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4277 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4278 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4283 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4285 /* Data sent down one of our channels. */
4286 int i = ssh_pkt_getuint32(pktin);
4289 struct ssh_channel *c;
4291 ssh_pkt_getstring(pktin, &p, &len);
4293 c = find234(ssh->channels, &i, ssh_channelfind);
4298 bufsize = x11_send(c->u.x11.s, p, len);
4301 bufsize = pfd_send(c->u.pfd.s, p, len);
4304 /* Data for an agent message. Buffer it. */
4306 if (c->u.a.lensofar < 4) {
4307 unsigned int l = min(4 - c->u.a.lensofar, len);
4308 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4312 c->u.a.lensofar += l;
4314 if (c->u.a.lensofar == 4) {
4316 4 + GET_32BIT(c->u.a.msglen);
4317 c->u.a.message = snewn(c->u.a.totallen,
4319 memcpy(c->u.a.message, c->u.a.msglen, 4);
4321 if (c->u.a.lensofar >= 4 && len > 0) {
4323 min(c->u.a.totallen - c->u.a.lensofar,
4325 memcpy(c->u.a.message + c->u.a.lensofar, p,
4329 c->u.a.lensofar += l;
4331 if (c->u.a.lensofar == c->u.a.totallen) {
4334 if (agent_query(c->u.a.message,
4337 ssh_agentf_callback, c))
4338 ssh_agentf_callback(c, reply, replylen);
4339 sfree(c->u.a.message);
4340 c->u.a.lensofar = 0;
4343 bufsize = 0; /* agent channels never back up */
4346 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4347 c->v.v1.throttling = 1;
4348 ssh1_throttle(ssh, +1);
4353 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
4356 ssh->exitcode = ssh_pkt_getuint32(pktin);
4357 sprintf(buf, "Server sent command exit status %d",
4360 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4362 * In case `helpful' firewalls or proxies tack
4363 * extra human-readable text on the end of the
4364 * session which we might mistake for another
4365 * encrypted packet, we close the session once
4366 * we've sent EXIT_CONFIRMATION.
4368 ssh->close_expected = TRUE;
4369 ssh_closing((Plug)ssh, NULL, 0, 0);
4372 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
4373 struct Packet *pktin)
4375 crBegin(ssh->do_ssh1_connection_crstate);
4377 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
4378 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
4379 ssh1_smsg_stdout_stderr_data;
4381 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
4382 ssh1_msg_channel_open_confirmation;
4383 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
4384 ssh1_msg_channel_open_failure;
4385 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
4386 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
4387 ssh1_msg_channel_close;
4388 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
4389 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
4391 if (ssh->cfg.agentfwd && agent_exists()) {
4392 logevent("Requesting agent forwarding");
4393 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
4397 if (pktin->type != SSH1_SMSG_SUCCESS
4398 && pktin->type != SSH1_SMSG_FAILURE) {
4399 bombout(("Protocol confusion"));
4401 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4402 logevent("Agent forwarding refused");
4404 logevent("Agent forwarding enabled");
4405 ssh->agentfwd_enabled = TRUE;
4406 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
4410 if (ssh->cfg.x11_forward) {
4411 char proto[20], data[64];
4412 logevent("Requesting X11 forwarding");
4413 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
4414 data, sizeof(data), ssh->cfg.x11_auth);
4415 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
4416 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
4417 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4418 PKT_STR, proto, PKT_STR, data,
4419 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
4422 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4423 PKT_STR, proto, PKT_STR, data, PKT_END);
4428 if (pktin->type != SSH1_SMSG_SUCCESS
4429 && pktin->type != SSH1_SMSG_FAILURE) {
4430 bombout(("Protocol confusion"));
4432 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4433 logevent("X11 forwarding refused");
4435 logevent("X11 forwarding enabled");
4436 ssh->X11_fwd_enabled = TRUE;
4437 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
4441 ssh_setup_portfwd(ssh, &ssh->cfg);
4442 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
4444 if (!ssh->cfg.nopty) {
4445 /* Unpick the terminal-speed string. */
4446 /* XXX perhaps we should allow no speeds to be sent. */
4447 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4448 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
4449 /* Send the pty request. */
4450 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
4451 PKT_STR, ssh->cfg.termtype,
4452 PKT_INT, ssh->term_height,
4453 PKT_INT, ssh->term_width,
4454 PKT_INT, 0, PKT_INT, 0, /* width,height in pixels */
4455 PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */
4456 PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */
4457 PKT_CHAR, 0, PKT_END);
4458 ssh->state = SSH_STATE_INTERMED;
4462 if (pktin->type != SSH1_SMSG_SUCCESS
4463 && pktin->type != SSH1_SMSG_FAILURE) {
4464 bombout(("Protocol confusion"));
4466 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4467 c_write_str(ssh, "Server refused to allocate pty\r\n");
4468 ssh->editing = ssh->echoing = 1;
4470 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
4471 ssh->ospeed, ssh->ispeed);
4473 ssh->editing = ssh->echoing = 1;
4476 if (ssh->cfg.compression) {
4477 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
4481 if (pktin->type != SSH1_SMSG_SUCCESS
4482 && pktin->type != SSH1_SMSG_FAILURE) {
4483 bombout(("Protocol confusion"));
4485 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4486 c_write_str(ssh, "Server refused to compress\r\n");
4488 logevent("Started compression");
4489 ssh->v1_compressing = TRUE;
4490 ssh->cs_comp_ctx = zlib_compress_init();
4491 logevent("Initialised zlib (RFC1950) compression");
4492 ssh->sc_comp_ctx = zlib_decompress_init();
4493 logevent("Initialised zlib (RFC1950) decompression");
4497 * Start the shell or command.
4499 * Special case: if the first-choice command is an SSH2
4500 * subsystem (hence not usable here) and the second choice
4501 * exists, we fall straight back to that.
4504 char *cmd = ssh->cfg.remote_cmd_ptr;
4506 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4507 cmd = ssh->cfg.remote_cmd_ptr2;
4508 ssh->fallback_cmd = TRUE;
4511 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
4513 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
4514 logevent("Started session");
4517 ssh->state = SSH_STATE_SESSION;
4518 if (ssh->size_needed)
4519 ssh_size(ssh, ssh->term_width, ssh->term_height);
4520 if (ssh->eof_needed)
4521 ssh_special(ssh, TS_EOF);
4524 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
4526 ssh->channels = newtree234(ssh_channelcmp);
4530 * By this point, most incoming packets are already being
4531 * handled by the dispatch table, and we need only pay
4532 * attention to the unusual ones.
4537 if (pktin->type == SSH1_SMSG_SUCCESS) {
4538 /* may be from EXEC_SHELL on some servers */
4539 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4540 /* may be from EXEC_SHELL on some servers
4541 * if no pty is available or in other odd cases. Ignore */
4543 bombout(("Strange packet received: type %d", pktin->type));
4548 int len = min(inlen, 512);
4549 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4550 PKT_INT, len, PKT_DATA, in, len,
4551 PKTT_OTHER, PKT_END);
4562 * Handle the top-level SSH2 protocol.
4564 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4569 ssh_pkt_getstring(pktin, &msg, &msglen);
4570 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
4575 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4577 /* log reason code in disconnect message */
4581 ssh_pkt_getstring(pktin, &msg, &msglen);
4582 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4585 void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
4587 /* Do nothing, because we're ignoring it! Duhh. */
4590 static void ssh1_protocol_setup(Ssh ssh)
4595 * Most messages are handled by the coroutines.
4597 for (i = 0; i < 256; i++)
4598 ssh->packet_dispatch[i] = NULL;
4601 * These special message types we install handlers for.
4603 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4604 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4605 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4608 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
4609 struct Packet *pktin)
4611 unsigned char *in=(unsigned char*)vin;
4612 if (ssh->state == SSH_STATE_CLOSED)
4615 if (pktin && ssh->packet_dispatch[pktin->type]) {
4616 ssh->packet_dispatch[pktin->type](ssh, pktin);
4620 if (!ssh->protocol_initial_phase_done) {
4621 if (do_ssh1_login(ssh, in, inlen, pktin))
4622 ssh->protocol_initial_phase_done = TRUE;
4627 do_ssh1_connection(ssh, in, inlen, pktin);
4631 * Utility routine for decoding comma-separated strings in KEXINIT.
4633 static int in_commasep_string(char *needle, char *haystack, int haylen)
4636 if (!needle || !haystack) /* protect against null pointers */
4638 needlen = strlen(needle);
4641 * Is it at the start of the string?
4643 if (haylen >= needlen && /* haystack is long enough */
4644 !memcmp(needle, haystack, needlen) && /* initial match */
4645 (haylen == needlen || haystack[needlen] == ',')
4646 /* either , or EOS follows */
4650 * If not, search for the next comma and resume after that.
4651 * If no comma found, terminate.
4653 while (haylen > 0 && *haystack != ',')
4654 haylen--, haystack++;
4657 haylen--, haystack++; /* skip over comma itself */
4662 * Similar routine for checking whether we have the first string in a list.
4664 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
4667 if (!needle || !haystack) /* protect against null pointers */
4669 needlen = strlen(needle);
4671 * Is it at the start of the string?
4673 if (haylen >= needlen && /* haystack is long enough */
4674 !memcmp(needle, haystack, needlen) && /* initial match */
4675 (haylen == needlen || haystack[needlen] == ',')
4676 /* either , or EOS follows */
4684 * SSH2 key creation method.
4686 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4687 unsigned char *sessid, char chr,
4688 unsigned char *keyspace)
4691 /* First 20 bytes. */
4693 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4695 SHA_Bytes(&s, H, 20);
4696 SHA_Bytes(&s, &chr, 1);
4697 SHA_Bytes(&s, sessid, 20);
4698 SHA_Final(&s, keyspace);
4699 /* Next 20 bytes. */
4701 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4703 SHA_Bytes(&s, H, 20);
4704 SHA_Bytes(&s, keyspace, 20);
4705 SHA_Final(&s, keyspace + 20);
4709 * Handle the SSH2 transport layer.
4711 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
4712 struct Packet *pktin)
4714 unsigned char *in = (unsigned char *)vin;
4715 struct do_ssh2_transport_state {
4716 int nbits, pbits, warn;
4717 Bignum p, g, e, f, K;
4718 int kex_init_value, kex_reply_value;
4719 const struct ssh_mac **maclist;
4721 const struct ssh2_cipher *cscipher_tobe;
4722 const struct ssh2_cipher *sccipher_tobe;
4723 const struct ssh_mac *csmac_tobe;
4724 const struct ssh_mac *scmac_tobe;
4725 const struct ssh_compress *cscomp_tobe;
4726 const struct ssh_compress *sccomp_tobe;
4727 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4728 int hostkeylen, siglen;
4729 void *hkey; /* actual host key */
4730 unsigned char exchange_hash[20];
4731 int n_preferred_kex;
4732 const struct ssh_kex *preferred_kex[KEX_MAX];
4733 int n_preferred_ciphers;
4734 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4735 const struct ssh_compress *preferred_comp;
4736 int got_session_id, activated_authconn;
4737 struct Packet *pktout;
4739 crState(do_ssh2_transport_state);
4741 crBegin(ssh->do_ssh2_transport_crstate);
4743 s->cscipher_tobe = s->sccipher_tobe = NULL;
4744 s->csmac_tobe = s->scmac_tobe = NULL;
4745 s->cscomp_tobe = s->sccomp_tobe = NULL;
4747 s->got_session_id = s->activated_authconn = FALSE;
4750 * Be prepared to work around the buggy MAC problem.
4752 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4753 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
4755 s->maclist = macs, s->nmacs = lenof(macs);
4758 ssh->pkt_ctx &= ~SSH2_PKTCTX_KEX_MASK;
4760 int i, j, commalist_started;
4763 * Set up the preferred key exchange. (NULL => warn below here)
4765 s->n_preferred_kex = 0;
4766 for (i = 0; i < KEX_MAX; i++) {
4767 switch (ssh->cfg.ssh_kexlist[i]) {
4769 s->preferred_kex[s->n_preferred_kex++] =
4770 &ssh_diffiehellman_gex;
4773 s->preferred_kex[s->n_preferred_kex++] =
4774 &ssh_diffiehellman_group14;
4777 s->preferred_kex[s->n_preferred_kex++] =
4778 &ssh_diffiehellman_group1;
4781 /* Flag for later. Don't bother if it's the last in
4783 if (i < KEX_MAX - 1) {
4784 s->preferred_kex[s->n_preferred_kex++] = NULL;
4791 * Set up the preferred ciphers. (NULL => warn below here)
4793 s->n_preferred_ciphers = 0;
4794 for (i = 0; i < CIPHER_MAX; i++) {
4795 switch (ssh->cfg.ssh_cipherlist[i]) {
4796 case CIPHER_BLOWFISH:
4797 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
4800 if (ssh->cfg.ssh2_des_cbc) {
4801 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
4805 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
4808 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
4811 /* Flag for later. Don't bother if it's the last in
4813 if (i < CIPHER_MAX - 1) {
4814 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
4821 * Set up preferred compression.
4823 if (ssh->cfg.compression)
4824 s->preferred_comp = &ssh_zlib;
4826 s->preferred_comp = &ssh_comp_none;
4829 * Enable queueing of outgoing auth- or connection-layer
4830 * packets while we are in the middle of a key exchange.
4832 ssh->queueing = TRUE;
4835 * Flag that KEX is in progress.
4837 ssh->kex_in_progress = TRUE;
4840 * Construct and send our key exchange packet.
4842 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
4843 for (i = 0; i < 16; i++)
4844 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
4845 /* List key exchange algorithms. */
4846 ssh2_pkt_addstring_start(s->pktout);
4847 commalist_started = 0;
4848 for (i = 0; i < s->n_preferred_kex; i++) {
4849 const struct ssh_kex *k = s->preferred_kex[i];
4850 if (!k) continue; /* warning flag */
4851 if (commalist_started)
4852 ssh2_pkt_addstring_str(s->pktout, ",");
4853 ssh2_pkt_addstring_str(s->pktout, s->preferred_kex[i]->name);
4854 commalist_started = 1;
4856 /* List server host key algorithms. */
4857 ssh2_pkt_addstring_start(s->pktout);
4858 for (i = 0; i < lenof(hostkey_algs); i++) {
4859 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
4860 if (i < lenof(hostkey_algs) - 1)
4861 ssh2_pkt_addstring_str(s->pktout, ",");
4863 /* List client->server encryption algorithms. */
4864 ssh2_pkt_addstring_start(s->pktout);
4865 commalist_started = 0;
4866 for (i = 0; i < s->n_preferred_ciphers; i++) {
4867 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4868 if (!c) continue; /* warning flag */
4869 for (j = 0; j < c->nciphers; j++) {
4870 if (commalist_started)
4871 ssh2_pkt_addstring_str(s->pktout, ",");
4872 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
4873 commalist_started = 1;
4876 /* List server->client encryption algorithms. */
4877 ssh2_pkt_addstring_start(s->pktout);
4878 commalist_started = 0;
4879 for (i = 0; i < s->n_preferred_ciphers; i++) {
4880 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4881 if (!c) continue; /* warning flag */
4882 for (j = 0; j < c->nciphers; j++) {
4883 if (commalist_started)
4884 ssh2_pkt_addstring_str(s->pktout, ",");
4885 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
4886 commalist_started = 1;
4889 /* List client->server MAC algorithms. */
4890 ssh2_pkt_addstring_start(s->pktout);
4891 for (i = 0; i < s->nmacs; i++) {
4892 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
4893 if (i < s->nmacs - 1)
4894 ssh2_pkt_addstring_str(s->pktout, ",");
4896 /* List server->client MAC algorithms. */
4897 ssh2_pkt_addstring_start(s->pktout);
4898 for (i = 0; i < s->nmacs; i++) {
4899 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
4900 if (i < s->nmacs - 1)
4901 ssh2_pkt_addstring_str(s->pktout, ",");
4903 /* List client->server compression algorithms. */
4904 ssh2_pkt_addstring_start(s->pktout);
4905 assert(lenof(compressions) > 1);
4906 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
4907 for (i = 0; i < lenof(compressions); i++) {
4908 const struct ssh_compress *c = compressions[i];
4909 if (c != s->preferred_comp) {
4910 ssh2_pkt_addstring_str(s->pktout, ",");
4911 ssh2_pkt_addstring_str(s->pktout, c->name);
4914 /* List server->client compression algorithms. */
4915 ssh2_pkt_addstring_start(s->pktout);
4916 assert(lenof(compressions) > 1);
4917 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
4918 for (i = 0; i < lenof(compressions); i++) {
4919 const struct ssh_compress *c = compressions[i];
4920 if (c != s->preferred_comp) {
4921 ssh2_pkt_addstring_str(s->pktout, ",");
4922 ssh2_pkt_addstring_str(s->pktout, c->name);
4925 /* List client->server languages. Empty list. */
4926 ssh2_pkt_addstring_start(s->pktout);
4927 /* List server->client languages. Empty list. */
4928 ssh2_pkt_addstring_start(s->pktout);
4929 /* First KEX packet does _not_ follow, because we're not that brave. */
4930 ssh2_pkt_addbool(s->pktout, FALSE);
4932 ssh2_pkt_adduint32(s->pktout, 0);
4935 ssh->exhash = ssh->exhashbase;
4936 sha_string(&ssh->exhash, s->pktout->data + 5, s->pktout->length - 5);
4938 ssh2_pkt_send_noqueue(ssh, s->pktout);
4942 if (pktin->length > 5)
4943 sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5);
4946 * Now examine the other side's KEXINIT to see what we're up
4951 int i, j, len, guessok;
4953 if (pktin->type != SSH2_MSG_KEXINIT) {
4954 bombout(("expected key exchange packet from server"));
4958 ssh->hostkey = NULL;
4959 s->cscipher_tobe = NULL;
4960 s->sccipher_tobe = NULL;
4961 s->csmac_tobe = NULL;
4962 s->scmac_tobe = NULL;
4963 s->cscomp_tobe = NULL;
4964 s->sccomp_tobe = NULL;
4965 pktin->savedpos += 16; /* skip garbage cookie */
4966 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
4968 for (i = 0; i < s->n_preferred_kex; i++) {
4969 const struct ssh_kex *k = s->preferred_kex[i];
4972 } else if (in_commasep_string(k->name, str, len)) {
4977 sk_set_frozen(ssh->s, 1);
4978 askalg(ssh->frontend, "key-exchange algorithm",
4980 sk_set_frozen(ssh->s, 0);
4986 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
4987 str ? str : "(null)"));
4991 * Note that the server's guess is considered wrong if it doesn't match
4992 * the first algorithm in our list, even if it's still the algorithm
4996 first_in_commasep_string(s->preferred_kex[0]->name, str, len);
4997 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
4998 for (i = 0; i < lenof(hostkey_algs); i++) {
4999 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5000 ssh->hostkey = hostkey_algs[i];
5004 guessok = guessok &&
5005 first_in_commasep_string(hostkey_algs[0]->name, str, len);
5006 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
5008 for (i = 0; i < s->n_preferred_ciphers; i++) {
5009 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5013 for (j = 0; j < c->nciphers; j++) {
5014 if (in_commasep_string(c->list[j]->name, str, len)) {
5015 s->cscipher_tobe = c->list[j];
5020 if (s->cscipher_tobe) {
5022 sk_set_frozen(ssh->s, 1);
5023 askalg(ssh->frontend, "client-to-server cipher",
5024 s->cscipher_tobe->name);
5025 sk_set_frozen(ssh->s, 0);
5030 if (!s->cscipher_tobe) {
5031 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
5032 str ? str : "(null)"));
5036 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
5038 for (i = 0; i < s->n_preferred_ciphers; i++) {
5039 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5043 for (j = 0; j < c->nciphers; j++) {
5044 if (in_commasep_string(c->list[j]->name, str, len)) {
5045 s->sccipher_tobe = c->list[j];
5050 if (s->sccipher_tobe) {
5052 sk_set_frozen(ssh->s, 1);
5053 askalg(ssh->frontend, "server-to-client cipher",
5054 s->sccipher_tobe->name);
5055 sk_set_frozen(ssh->s, 0);
5060 if (!s->sccipher_tobe) {
5061 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
5062 str ? str : "(null)"));
5066 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
5067 for (i = 0; i < s->nmacs; i++) {
5068 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5069 s->csmac_tobe = s->maclist[i];
5073 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
5074 for (i = 0; i < s->nmacs; i++) {
5075 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5076 s->scmac_tobe = s->maclist[i];
5080 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
5081 for (i = 0; i < lenof(compressions) + 1; i++) {
5082 const struct ssh_compress *c =
5083 i == 0 ? s->preferred_comp : compressions[i - 1];
5084 if (in_commasep_string(c->name, str, len)) {
5089 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
5090 for (i = 0; i < lenof(compressions) + 1; i++) {
5091 const struct ssh_compress *c =
5092 i == 0 ? s->preferred_comp : compressions[i - 1];
5093 if (in_commasep_string(c->name, str, len)) {
5098 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5099 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
5100 if (ssh2_pkt_getbool(pktin) && !guessok) /* first_kex_packet_follows */
5101 crWaitUntil(pktin); /* Ignore packet */
5105 * Work out the number of bits of key we will need from the key
5106 * exchange. We start with the maximum key length of either
5112 csbits = s->cscipher_tobe->keylen;
5113 scbits = s->sccipher_tobe->keylen;
5114 s->nbits = (csbits > scbits ? csbits : scbits);
5116 /* The keys only have 160-bit entropy, since they're based on
5117 * a SHA-1 hash. So cap the key size at 160 bits. */
5122 * If we're doing Diffie-Hellman group exchange, start by
5123 * requesting a group.
5125 if (!ssh->kex->pdata) {
5126 logevent("Doing Diffie-Hellman group exchange");
5127 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
5129 * Work out how big a DH group we will need to allow that
5132 s->pbits = 512 << ((s->nbits - 1) / 64);
5133 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5134 ssh2_pkt_adduint32(s->pktout, s->pbits);
5135 ssh2_pkt_send_noqueue(ssh, s->pktout);
5138 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
5139 bombout(("expected key exchange group packet from server"));
5142 s->p = ssh2_pkt_getmp(pktin);
5143 s->g = ssh2_pkt_getmp(pktin);
5144 if (!s->p || !s->g) {
5145 bombout(("unable to read mp-ints from incoming group packet"));
5148 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
5149 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5150 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
5152 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP;
5153 ssh->kex_ctx = dh_setup_group(ssh->kex);
5154 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5155 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
5156 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5157 ssh->kex->groupname);
5160 logevent("Doing Diffie-Hellman key exchange");
5162 * Now generate and send e for Diffie-Hellman.
5164 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
5165 s->pktout = ssh2_pkt_init(s->kex_init_value);
5166 ssh2_pkt_addmp(s->pktout, s->e);
5167 ssh2_pkt_send_noqueue(ssh, s->pktout);
5170 if (pktin->type != s->kex_reply_value) {
5171 bombout(("expected key exchange reply packet from server"));
5174 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5175 s->f = ssh2_pkt_getmp(pktin);
5177 bombout(("unable to parse key exchange reply packet"));
5180 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
5182 s->K = dh_find_K(ssh->kex_ctx, s->f);
5184 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
5185 if (ssh->kex == &ssh_diffiehellman_gex) {
5186 sha_uint32(&ssh->exhash, s->pbits);
5187 sha_mpint(&ssh->exhash, s->p);
5188 sha_mpint(&ssh->exhash, s->g);
5190 sha_mpint(&ssh->exhash, s->e);
5191 sha_mpint(&ssh->exhash, s->f);
5192 sha_mpint(&ssh->exhash, s->K);
5193 SHA_Final(&ssh->exhash, s->exchange_hash);
5195 dh_cleanup(ssh->kex_ctx);
5196 ssh->kex_ctx = NULL;
5199 debug(("Exchange hash is:\n"));
5200 dmemdump(s->exchange_hash, 20);
5203 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5205 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
5206 (char *)s->exchange_hash, 20)) {
5207 bombout(("Server's host key did not match the signature supplied"));
5212 * Authenticate remote host: verify host key. (We've already
5213 * checked the signature of the exchange hash.)
5215 s->keystr = ssh->hostkey->fmtkey(s->hkey);
5216 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
5217 sk_set_frozen(ssh->s, 1);
5218 verify_ssh_host_key(ssh->frontend,
5219 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
5220 s->keystr, s->fingerprint);
5221 sk_set_frozen(ssh->s, 0);
5222 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5223 logevent("Host key fingerprint is:");
5224 logevent(s->fingerprint);
5226 sfree(s->fingerprint);
5228 ssh->hostkey->freekey(s->hkey);
5231 * The exchange hash from the very first key exchange is also
5232 * the session id, used in session key construction and
5235 if (!s->got_session_id) {
5236 memcpy(ssh->v2_session_id, s->exchange_hash,
5237 sizeof(s->exchange_hash));
5238 s->got_session_id = TRUE;
5242 * Send SSH2_MSG_NEWKEYS.
5244 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
5245 ssh2_pkt_send_noqueue(ssh, s->pktout);
5246 ssh->outgoing_data_size = 0; /* start counting from here */
5249 * We've sent client NEWKEYS, so create and initialise
5250 * client-to-server session keys.
5252 if (ssh->cs_cipher_ctx)
5253 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
5254 ssh->cscipher = s->cscipher_tobe;
5255 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
5257 if (ssh->cs_mac_ctx)
5258 ssh->csmac->free_context(ssh->cs_mac_ctx);
5259 ssh->csmac = s->csmac_tobe;
5260 ssh->cs_mac_ctx = ssh->csmac->make_context();
5262 if (ssh->cs_comp_ctx)
5263 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
5264 ssh->cscomp = s->cscomp_tobe;
5265 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
5268 * Set IVs on client-to-server keys. Here we use the exchange
5269 * hash from the _first_ key exchange.
5272 unsigned char keyspace[40];
5273 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
5274 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
5275 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
5276 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
5277 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
5278 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
5281 logeventf(ssh, "Initialised %.200s client->server encryption",
5282 ssh->cscipher->text_name);
5283 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
5284 ssh->csmac->text_name);
5285 if (ssh->cscomp->text_name)
5286 logeventf(ssh, "Initialised %s compression",
5287 ssh->cscomp->text_name);
5290 * Now our end of the key exchange is complete, we can send all
5291 * our queued higher-layer packets.
5293 ssh->queueing = FALSE;
5294 ssh2_pkt_queuesend(ssh);
5297 * Expect SSH2_MSG_NEWKEYS from server.
5300 if (pktin->type != SSH2_MSG_NEWKEYS) {
5301 bombout(("expected new-keys packet from server"));
5304 ssh->incoming_data_size = 0; /* start counting from here */
5307 * We've seen server NEWKEYS, so create and initialise
5308 * server-to-client session keys.
5310 if (ssh->sc_cipher_ctx)
5311 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
5312 ssh->sccipher = s->sccipher_tobe;
5313 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
5315 if (ssh->sc_mac_ctx)
5316 ssh->scmac->free_context(ssh->sc_mac_ctx);
5317 ssh->scmac = s->scmac_tobe;
5318 ssh->sc_mac_ctx = ssh->scmac->make_context();
5320 if (ssh->sc_comp_ctx)
5321 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
5322 ssh->sccomp = s->sccomp_tobe;
5323 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
5326 * Set IVs on server-to-client keys. Here we use the exchange
5327 * hash from the _first_ key exchange.
5330 unsigned char keyspace[40];
5331 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
5332 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
5333 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
5334 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
5335 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
5336 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
5338 logeventf(ssh, "Initialised %.200s server->client encryption",
5339 ssh->sccipher->text_name);
5340 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
5341 ssh->scmac->text_name);
5342 if (ssh->sccomp->text_name)
5343 logeventf(ssh, "Initialised %s decompression",
5344 ssh->sccomp->text_name);
5347 * Free key exchange data.
5351 if (ssh->kex == &ssh_diffiehellman_gex) {
5357 * Key exchange is over. Loop straight back round if we have a
5358 * deferred rekey reason.
5360 if (ssh->deferred_rekey_reason) {
5361 logevent(ssh->deferred_rekey_reason);
5363 ssh->deferred_rekey_reason = NULL;
5364 goto begin_key_exchange;
5368 * Otherwise, schedule a timer for our next rekey.
5370 ssh->kex_in_progress = FALSE;
5371 ssh->last_rekey = GETTICKCOUNT();
5372 if (ssh->cfg.ssh_rekey_time != 0)
5373 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5377 * If this is the first key exchange phase, we must pass the
5378 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
5379 * wants to see it but because it will need time to initialise
5380 * itself before it sees an actual packet. In subsequent key
5381 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
5382 * it would only confuse the layer above.
5384 if (s->activated_authconn) {
5387 s->activated_authconn = TRUE;
5390 * Now we're encrypting. Begin returning 1 to the protocol main
5391 * function so that other things can run on top of the
5392 * transport. If we ever see a KEXINIT, we must go back to the
5395 * We _also_ go back to the start if we see pktin==NULL and
5396 * inlen==-1, because this is a special signal meaning
5397 * `initiate client-driven rekey', and `in' contains a message
5398 * giving the reason for the rekey.
5400 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
5401 (!pktin && inlen == -1))) {
5406 logevent("Server initiated key re-exchange");
5409 * Special case: if the server bug is set that doesn't
5410 * allow rekeying, we give a different log message and
5411 * continue waiting. (If such a server _initiates_ a rekey,
5412 * we process it anyway!)
5414 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
5415 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
5417 /* Reset the counters, so that at least this message doesn't
5418 * hit the event log _too_ often. */
5419 ssh->outgoing_data_size = 0;
5420 ssh->incoming_data_size = 0;
5421 if (ssh->cfg.ssh_rekey_time != 0) {
5423 schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5426 goto wait_for_rekey; /* this is utterly horrid */
5428 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
5431 goto begin_key_exchange;
5437 * Add data to an SSH2 channel output buffer.
5439 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
5442 bufchain_add(&c->v.v2.outbuffer, buf, len);
5446 * Attempt to send data on an SSH2 channel.
5448 static int ssh2_try_send(struct ssh_channel *c)
5451 struct Packet *pktout;
5453 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
5456 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
5457 if ((unsigned)len > c->v.v2.remwindow)
5458 len = c->v.v2.remwindow;
5459 if ((unsigned)len > c->v.v2.remmaxpkt)
5460 len = c->v.v2.remmaxpkt;
5461 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
5462 ssh2_pkt_adduint32(pktout, c->remoteid);
5463 dont_log_data(ssh, pktout, PKTLOG_OMIT);
5464 ssh2_pkt_addstring_start(pktout);
5465 ssh2_pkt_addstring_data(pktout, data, len);
5466 end_log_omission(ssh, pktout);
5467 ssh2_pkt_send(ssh, pktout);
5468 bufchain_consume(&c->v.v2.outbuffer, len);
5469 c->v.v2.remwindow -= len;
5473 * After having sent as much data as we can, return the amount
5476 return bufchain_size(&c->v.v2.outbuffer);
5480 * Potentially enlarge the window on an SSH2 channel.
5482 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
5487 * Never send WINDOW_ADJUST for a channel that the remote side
5488 * already thinks it's closed; there's no point, since it won't
5489 * be sending any more data anyway.
5495 * Only send a WINDOW_ADJUST if there's significantly more window
5496 * available than the other end thinks there is. This saves us
5497 * sending a WINDOW_ADJUST for every character in a shell session.
5499 * "Significant" is arbitrarily defined as half the window size.
5501 if (newwin > c->v.v2.locwindow * 2) {
5502 struct Packet *pktout;
5504 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5505 ssh2_pkt_adduint32(pktout, c->remoteid);
5506 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
5507 ssh2_pkt_send(ssh, pktout);
5508 c->v.v2.locwindow = newwin;
5512 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
5514 unsigned i = ssh_pkt_getuint32(pktin);
5515 struct ssh_channel *c;
5516 c = find234(ssh->channels, &i, ssh_channelfind);
5517 if (c && !c->closes)
5518 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
5521 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
5525 unsigned i = ssh_pkt_getuint32(pktin);
5526 struct ssh_channel *c;
5527 c = find234(ssh->channels, &i, ssh_channelfind);
5529 return; /* nonexistent channel */
5530 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5531 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
5532 return; /* extended but not stderr */
5533 ssh_pkt_getstring(pktin, &data, &length);
5536 c->v.v2.locwindow -= length;
5538 case CHAN_MAINSESSION:
5540 from_backend(ssh->frontend, pktin->type ==
5541 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5545 bufsize = x11_send(c->u.x11.s, data, length);
5548 bufsize = pfd_send(c->u.pfd.s, data, length);
5551 while (length > 0) {
5552 if (c->u.a.lensofar < 4) {
5553 unsigned int l = min(4 - c->u.a.lensofar, length);
5554 memcpy(c->u.a.msglen + c->u.a.lensofar,
5558 c->u.a.lensofar += l;
5560 if (c->u.a.lensofar == 4) {
5562 4 + GET_32BIT(c->u.a.msglen);
5563 c->u.a.message = snewn(c->u.a.totallen,
5565 memcpy(c->u.a.message, c->u.a.msglen, 4);
5567 if (c->u.a.lensofar >= 4 && length > 0) {
5569 min(c->u.a.totallen - c->u.a.lensofar,
5571 memcpy(c->u.a.message + c->u.a.lensofar,
5575 c->u.a.lensofar += l;
5577 if (c->u.a.lensofar == c->u.a.totallen) {
5580 if (agent_query(c->u.a.message,
5583 ssh_agentf_callback, c))
5584 ssh_agentf_callback(c, reply, replylen);
5585 sfree(c->u.a.message);
5586 c->u.a.lensofar = 0;
5593 * If we are not buffering too much data,
5594 * enlarge the window again at the remote side.
5596 if (bufsize < OUR_V2_WINSIZE)
5597 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5601 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
5603 unsigned i = ssh_pkt_getuint32(pktin);
5604 struct ssh_channel *c;
5606 c = find234(ssh->channels, &i, ssh_channelfind);
5608 return; /* nonexistent channel */
5610 if (c->type == CHAN_X11) {
5612 * Remote EOF on an X11 channel means we should
5613 * wrap up and close the channel ourselves.
5615 x11_close(c->u.x11.s);
5617 } else if (c->type == CHAN_AGENT) {
5619 } else if (c->type == CHAN_SOCKDATA) {
5620 pfd_close(c->u.pfd.s);
5625 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
5627 unsigned i = ssh_pkt_getuint32(pktin);
5628 struct ssh_channel *c;
5629 struct Packet *pktout;
5631 c = find234(ssh->channels, &i, ssh_channelfind);
5632 if (!c || c->halfopen) {
5633 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5634 c ? "half-open" : "nonexistent", i));
5637 /* Do pre-close processing on the channel. */
5639 case CHAN_MAINSESSION:
5640 ssh->mainchan = NULL;
5641 update_specials_menu(ssh->frontend);
5644 if (c->u.x11.s != NULL)
5645 x11_close(c->u.x11.s);
5652 if (c->u.pfd.s != NULL)
5653 pfd_close(c->u.pfd.s);
5657 if (c->closes == 0) {
5658 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5659 ssh2_pkt_adduint32(pktout, c->remoteid);
5660 ssh2_pkt_send(ssh, pktout);
5662 del234(ssh->channels, c);
5663 bufchain_clear(&c->v.v2.outbuffer);
5667 * See if that was the last channel left open.
5668 * (This is only our termination condition if we're
5669 * not running in -N mode.)
5671 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
5672 logevent("All channels closed. Disconnecting");
5675 * We used to send SSH_MSG_DISCONNECT here,
5676 * because I'd believed that _every_ conforming
5677 * SSH2 connection had to end with a disconnect
5678 * being sent by at least one side; apparently
5679 * I was wrong and it's perfectly OK to
5680 * unceremoniously slam the connection shut
5681 * when you're done, and indeed OpenSSH feels
5682 * this is more polite than sending a
5683 * DISCONNECT. So now we don't.
5685 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5686 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
5687 ssh2_pkt_addstring(s->pktout, "All open channels closed");
5688 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
5689 ssh2_pkt_send_noqueue(ssh, s->pktout);
5691 ssh->close_expected = TRUE;
5692 ssh_closing((Plug)ssh, NULL, 0, 0);
5696 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5698 unsigned i = ssh_pkt_getuint32(pktin);
5699 struct ssh_channel *c;
5700 struct Packet *pktout;
5702 c = find234(ssh->channels, &i, ssh_channelfind);
5704 return; /* nonexistent channel */
5705 if (c->type != CHAN_SOCKDATA_DORMANT)
5706 return; /* dunno why they're confirming this */
5707 c->remoteid = ssh_pkt_getuint32(pktin);
5708 c->halfopen = FALSE;
5709 c->type = CHAN_SOCKDATA;
5710 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
5711 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
5713 pfd_confirm(c->u.pfd.s);
5716 * We have a pending close on this channel,
5717 * which we decided on before the server acked
5718 * the channel open. So now we know the
5719 * remoteid, we can close it again.
5721 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5722 ssh2_pkt_adduint32(pktout, c->remoteid);
5723 ssh2_pkt_send(ssh, pktout);
5727 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5729 static const char *const reasons[] = {
5730 "<unknown reason code>",
5731 "Administratively prohibited",
5733 "Unknown channel type",
5734 "Resource shortage",
5736 unsigned i = ssh_pkt_getuint32(pktin);
5737 unsigned reason_code;
5738 char *reason_string;
5741 struct ssh_channel *c;
5742 c = find234(ssh->channels, &i, ssh_channelfind);
5744 return; /* nonexistent channel */
5745 if (c->type != CHAN_SOCKDATA_DORMANT)
5746 return; /* dunno why they're failing this */
5748 reason_code = ssh_pkt_getuint32(pktin);
5749 if (reason_code >= lenof(reasons))
5750 reason_code = 0; /* ensure reasons[reason_code] in range */
5751 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
5752 message = dupprintf("Forwarded connection refused by"
5753 " server: %s [%.*s]", reasons[reason_code],
5754 reason_length, reason_string);
5758 pfd_close(c->u.pfd.s);
5760 del234(ssh->channels, c);
5764 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
5768 int typelen, want_reply;
5769 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
5770 struct ssh_channel *c;
5771 struct Packet *pktout;
5773 localid = ssh_pkt_getuint32(pktin);
5774 ssh_pkt_getstring(pktin, &type, &typelen);
5775 want_reply = ssh2_pkt_getbool(pktin);
5778 * First, check that the channel exists. Otherwise,
5779 * we can instantly disconnect with a rude message.
5781 c = find234(ssh->channels, &localid, ssh_channelfind);
5784 sprintf(buf, "Received channel request for nonexistent"
5785 " channel %d", localid);
5787 pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5788 ssh2_pkt_adduint32(pktout, SSH2_DISCONNECT_BY_APPLICATION);
5789 ssh2_pkt_addstring(pktout, buf);
5790 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5791 ssh2_pkt_send_noqueue(ssh, pktout);
5792 connection_fatal(ssh->frontend, "%s", buf);
5793 ssh->close_expected = TRUE;
5794 ssh_closing((Plug)ssh, NULL, 0, 0);
5799 * Having got the channel number, we now look at
5800 * the request type string to see if it's something
5803 if (c == ssh->mainchan) {
5805 * We recognise "exit-status" and "exit-signal" on
5806 * the primary channel.
5808 if (typelen == 11 &&
5809 !memcmp(type, "exit-status", 11)) {
5811 ssh->exitcode = ssh_pkt_getuint32(pktin);
5812 logeventf(ssh, "Server sent command exit status %d",
5814 reply = SSH2_MSG_CHANNEL_SUCCESS;
5816 } else if (typelen == 11 &&
5817 !memcmp(type, "exit-signal", 11)) {
5819 int is_plausible = TRUE, is_int = FALSE;
5820 char *fmt_sig = "", *fmt_msg = "";
5822 int msglen = 0, core = FALSE;
5823 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
5824 * provide an `int' for the signal, despite its
5825 * having been a `string' in the drafts since at
5826 * least 2001. (Fixed in session.c 1.147.) Try to
5827 * infer which we can safely parse it as. */
5829 unsigned char *p = pktin->body +
5831 long len = pktin->length - pktin->savedpos;
5832 unsigned long num = GET_32BIT(p); /* what is it? */
5833 /* If it's 0, it hardly matters; assume string */
5837 int maybe_int = FALSE, maybe_str = FALSE;
5838 #define CHECK_HYPOTHESIS(offset, result) \
5841 if (q >= 0 && q+4 <= len) { \
5842 q = q + 4 + GET_32BIT(p+q); \
5843 if (q >= 0 && q+4 <= len && \
5844 ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
5848 CHECK_HYPOTHESIS(4+1, maybe_int);
5849 CHECK_HYPOTHESIS(4+num+1, maybe_str);
5850 #undef CHECK_HYPOTHESIS
5851 if (maybe_int && !maybe_str)
5853 else if (!maybe_int && maybe_str)
5856 /* Crikey. Either or neither. Panic. */
5857 is_plausible = FALSE;
5862 /* Old non-standard OpenSSH. */
5863 int signum = ssh_pkt_getuint32(pktin);
5864 fmt_sig = dupprintf(" %d", signum);
5866 /* As per the drafts. */
5869 ssh_pkt_getstring(pktin, &sig, &siglen);
5870 /* Signal name isn't supposed to be blank, but
5871 * let's cope gracefully if it is. */
5873 fmt_sig = dupprintf(" \"%.*s\"",
5877 core = ssh2_pkt_getbool(pktin);
5878 ssh_pkt_getstring(pktin, &msg, &msglen);
5880 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
5882 /* ignore lang tag */
5883 } /* else don't attempt to parse */
5884 logeventf(ssh, "Server exited on signal%s%s%s",
5885 fmt_sig, core ? " (core dumped)" : "",
5887 if (*fmt_sig) sfree(fmt_sig);
5888 if (*fmt_msg) sfree(fmt_msg);
5889 reply = SSH2_MSG_CHANNEL_SUCCESS;
5894 * This is a channel request we don't know
5895 * about, so we now either ignore the request
5896 * or respond with CHANNEL_FAILURE, depending
5899 reply = SSH2_MSG_CHANNEL_FAILURE;
5902 pktout = ssh2_pkt_init(reply);
5903 ssh2_pkt_adduint32(pktout, c->remoteid);
5904 ssh2_pkt_send(ssh, pktout);
5908 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
5911 int typelen, want_reply;
5912 struct Packet *pktout;
5914 ssh_pkt_getstring(pktin, &type, &typelen);
5915 want_reply = ssh2_pkt_getbool(pktin);
5918 * We currently don't support any global requests
5919 * at all, so we either ignore the request or
5920 * respond with REQUEST_FAILURE, depending on
5924 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
5925 ssh2_pkt_send(ssh, pktout);
5929 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
5937 struct ssh_channel *c;
5938 unsigned remid, winsize, pktsize;
5939 struct Packet *pktout;
5941 ssh_pkt_getstring(pktin, &type, &typelen);
5942 c = snew(struct ssh_channel);
5945 remid = ssh_pkt_getuint32(pktin);
5946 winsize = ssh_pkt_getuint32(pktin);
5947 pktsize = ssh_pkt_getuint32(pktin);
5949 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5952 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5953 addrstr = snewn(peeraddrlen+1, char);
5954 memcpy(addrstr, peeraddr, peeraddrlen);
5955 addrstr[peeraddrlen] = '\0';
5956 peerport = ssh_pkt_getuint32(pktin);
5958 logeventf(ssh, "Received X11 connect request from %s:%d",
5961 if (!ssh->X11_fwd_enabled)
5962 error = "X11 forwarding is not enabled";
5963 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
5964 ssh->x11auth, addrstr, peerport,
5965 &ssh->cfg) != NULL) {
5966 error = "Unable to open an X11 connection";
5968 logevent("Opening X11 forward connection succeeded");
5973 } else if (typelen == 15 &&
5974 !memcmp(type, "forwarded-tcpip", 15)) {
5975 struct ssh_rportfwd pf, *realpf;
5978 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
5979 pf.sport = ssh_pkt_getuint32(pktin);
5980 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5981 peerport = ssh_pkt_getuint32(pktin);
5982 realpf = find234(ssh->rportfwds, &pf, NULL);
5983 logeventf(ssh, "Received remote port %d open request "
5984 "from %s:%d", pf.sport, peeraddr, peerport);
5985 if (realpf == NULL) {
5986 error = "Remote port is not recognised";
5988 const char *e = pfd_newconnect(&c->u.pfd.s,
5992 realpf->pfrec->addressfamily);
5993 logeventf(ssh, "Attempting to forward remote port to "
5994 "%s:%d", realpf->dhost, realpf->dport);
5996 logeventf(ssh, "Port open failed: %s", e);
5997 error = "Port open failed";
5999 logevent("Forwarded port opened successfully");
6000 c->type = CHAN_SOCKDATA;
6003 } else if (typelen == 22 &&
6004 !memcmp(type, "auth-agent@openssh.com", 3)) {
6005 if (!ssh->agentfwd_enabled)
6006 error = "Agent forwarding is not enabled";
6008 c->type = CHAN_AGENT; /* identify channel type */
6009 c->u.a.lensofar = 0;
6012 error = "Unsupported channel type requested";
6015 c->remoteid = remid;
6016 c->halfopen = FALSE;
6018 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
6019 ssh2_pkt_adduint32(pktout, c->remoteid);
6020 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
6021 ssh2_pkt_addstring(pktout, error);
6022 ssh2_pkt_addstring(pktout, "en"); /* language tag */
6023 ssh2_pkt_send(ssh, pktout);
6024 logeventf(ssh, "Rejected channel open: %s", error);
6027 c->localid = alloc_channel_id(ssh);
6029 c->v.v2.locwindow = OUR_V2_WINSIZE;
6030 c->v.v2.remwindow = winsize;
6031 c->v.v2.remmaxpkt = pktsize;
6032 bufchain_init(&c->v.v2.outbuffer);
6033 add234(ssh->channels, c);
6034 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
6035 ssh2_pkt_adduint32(pktout, c->remoteid);
6036 ssh2_pkt_adduint32(pktout, c->localid);
6037 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
6038 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
6039 ssh2_pkt_send(ssh, pktout);
6044 * Handle the SSH2 userauth and connection layers.
6046 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
6047 struct Packet *pktin)
6049 struct do_ssh2_authconn_state {
6051 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
6053 AUTH_KEYBOARD_INTERACTIVE
6057 AUTH_TYPE_PUBLICKEY,
6058 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
6059 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
6061 AUTH_TYPE_KEYBOARD_INTERACTIVE,
6062 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
6064 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
6065 int tried_pubkey_config, tried_agent;
6066 int kbd_inter_running, kbd_inter_refused;
6068 int num_prompts, curr_prompt, echo;
6073 void *publickey_blob;
6074 int publickey_bloblen;
6075 unsigned char request[5], *response, *p;
6079 char *pkblob, *alg, *commentp;
6080 int pklen, alglen, commentlen;
6081 int siglen, retlen, len;
6082 char *q, *agentreq, *ret;
6084 int num_env, env_left, env_ok;
6085 struct Packet *pktout;
6087 crState(do_ssh2_authconn_state);
6089 crBegin(ssh->do_ssh2_authconn_crstate);
6092 * Request userauth protocol, and await a response to it.
6094 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6095 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
6096 ssh2_pkt_send(ssh, s->pktout);
6097 crWaitUntilV(pktin);
6098 if (pktin->type != SSH2_MSG_SERVICE_ACCEPT) {
6099 bombout(("Server refused user authentication protocol"));
6104 * We repeat this whole loop, including the username prompt,
6105 * until we manage a successful authentication. If the user
6106 * types the wrong _password_, they can be sent back to the
6107 * beginning to try another username, if this is configured on.
6108 * (If they specify a username in the config, they are never
6109 * asked, even if they do give a wrong password.)
6111 * I think this best serves the needs of
6113 * - the people who have no configuration, no keys, and just
6114 * want to try repeated (username,password) pairs until they
6115 * type both correctly
6117 * - people who have keys and configuration but occasionally
6118 * need to fall back to passwords
6120 * - people with a key held in Pageant, who might not have
6121 * logged in to a particular machine before; so they want to
6122 * type a username, and then _either_ their key will be
6123 * accepted, _or_ they will type a password. If they mistype
6124 * the username they will want to be able to get back and
6127 s->username[0] = '\0';
6128 s->got_username = FALSE;
6133 if (s->got_username && !ssh->cfg.change_username) {
6135 * We got a username last time round this loop, and
6136 * with change_username turned off we don't try to get
6139 } else if (!*ssh->cfg.username) {
6140 if (ssh_get_line && !ssh_getline_pw_only) {
6141 if (!ssh_get_line("login as: ",
6142 s->username, sizeof(s->username), FALSE)) {
6144 * get_line failed to get a username.
6147 logevent("No username provided. Abandoning session.");
6148 ssh->close_expected = TRUE;
6149 ssh_closing((Plug)ssh, NULL, 0, 0);
6153 int ret; /* need not be saved across crReturn */
6154 c_write_str(ssh, "login as: ");
6156 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
6158 crWaitUntilV(!pktin);
6159 ret = process_userpass_input(ssh, in, inlen);
6163 c_write_str(ssh, "\r\n");
6165 s->username[strcspn(s->username, "\n\r")] = '\0';
6168 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
6169 s->username[sizeof(s->username)-1] = '\0';
6170 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
6171 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
6172 c_write_str(ssh, stuff);
6176 s->got_username = TRUE;
6179 * Send an authentication request using method "none": (a)
6180 * just in case it succeeds, and (b) so that we know what
6181 * authentication methods we can usefully try next.
6183 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6185 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6186 ssh2_pkt_addstring(s->pktout, s->username);
6187 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
6188 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6189 ssh2_pkt_send(ssh, s->pktout);
6190 s->type = AUTH_TYPE_NONE;
6192 s->we_are_in = FALSE;
6194 s->tried_pubkey_config = FALSE;
6195 s->tried_agent = FALSE;
6196 s->kbd_inter_running = FALSE;
6197 s->kbd_inter_refused = FALSE;
6198 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
6199 if (!filename_is_null(ssh->cfg.keyfile)) {
6201 logeventf(ssh, "Reading private key file \"%.150s\"",
6202 filename_to_str(&ssh->cfg.keyfile));
6203 keytype = key_type(&ssh->cfg.keyfile);
6204 if (keytype == SSH_KEYTYPE_SSH2) {
6206 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
6207 &s->publickey_bloblen, NULL);
6210 logeventf(ssh, "Unable to use this key file (%s)",
6211 key_type_to_str(keytype));
6212 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6214 filename_to_str(&ssh->cfg.keyfile),
6215 key_type_to_str(keytype));
6216 c_write_str(ssh, msgbuf);
6218 s->publickey_blob = NULL;
6221 s->publickey_blob = NULL;
6225 * Wait for the result of the last authentication request.
6228 crWaitUntilV(pktin);
6229 while (pktin->type == SSH2_MSG_USERAUTH_BANNER) {
6233 * Don't show the banner if we're operating in
6234 * non-verbose non-interactive mode. (It's probably
6235 * a script, which means nobody will read the
6236 * banner _anyway_, and moreover the printing of
6237 * the banner will screw up processing on the
6238 * output of (say) plink.)
6240 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
6241 ssh_pkt_getstring(pktin, &banner, &size);
6243 c_write_untrusted(ssh, banner, size);
6245 crWaitUntilV(pktin);
6247 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
6248 logevent("Access granted");
6249 s->we_are_in = TRUE;
6253 if (s->kbd_inter_running &&
6254 pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
6256 * This is either a further set-of-prompts packet
6257 * in keyboard-interactive authentication, or it's
6258 * the same one and we came back here with `gotit'
6259 * set. In the former case, we must reset the
6260 * curr_prompt variable.
6264 } else if (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
6265 /* FIXME: perhaps we should support this? */
6266 bombout(("PASSWD_CHANGEREQ not yet supported"));
6268 } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
6269 bombout(("Strange packet received during authentication: type %d",
6277 * OK, we're now sitting on a USERAUTH_FAILURE message, so
6278 * we can look at the string in it and know what we can
6279 * helpfully try next.
6281 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
6284 ssh_pkt_getstring(pktin, &methods, &methlen);
6285 s->kbd_inter_running = FALSE;
6286 if (!ssh2_pkt_getbool(pktin)) {
6288 * We have received an unequivocal Access
6289 * Denied. This can translate to a variety of
6292 * - if we'd just tried "none" authentication,
6293 * it's not worth printing anything at all
6295 * - if we'd just tried a public key _offer_,
6296 * the message should be "Server refused our
6297 * key" (or no message at all if the key
6298 * came from Pageant)
6300 * - if we'd just tried anything else, the
6301 * message really should be "Access denied".
6303 * Additionally, if we'd just tried password
6304 * authentication, we should break out of this
6305 * whole loop so as to go back to the username
6306 * prompt (iff we're configured to allow
6307 * username change attempts).
6309 if (s->type == AUTH_TYPE_NONE) {
6311 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
6312 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
6313 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
6314 c_write_str(ssh, "Server refused our key\r\n");
6315 logevent("Server refused public key");
6316 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
6317 /* server declined keyboard-interactive; ignore */
6319 c_write_str(ssh, "Access denied\r\n");
6320 logevent("Access denied");
6321 if (s->type == AUTH_TYPE_PASSWORD &&
6322 ssh->cfg.change_username) {
6323 /* XXX perhaps we should allow
6324 * keyboard-interactive to do this too? */
6325 s->we_are_in = FALSE;
6330 c_write_str(ssh, "Further authentication required\r\n");
6331 logevent("Further authentication required");
6335 in_commasep_string("publickey", methods, methlen);
6337 in_commasep_string("password", methods, methlen);
6338 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
6339 in_commasep_string("keyboard-interactive", methods, methlen);
6343 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6347 * Most password/passphrase prompts will be
6348 * non-echoing, so we set this to 0 by default.
6349 * Exception is that some keyboard-interactive prompts
6350 * can be echoing, in which case we'll set this to 1.
6354 if (!s->method && s->can_pubkey &&
6355 agent_exists() && !s->tried_agent) {
6357 * Attempt public-key authentication using Pageant.
6362 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6363 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6365 s->tried_agent = TRUE;
6367 logevent("Pageant is running. Requesting keys.");
6369 /* Request the keys held by the agent. */
6370 PUT_32BIT(s->request, 1);
6371 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
6372 if (!agent_query(s->request, 5, &r, &s->responselen,
6373 ssh_agent_callback, ssh)) {
6377 bombout(("Unexpected data from server while"
6378 " waiting for agent response"));
6381 } while (pktin || inlen > 0);
6382 r = ssh->agent_response;
6383 s->responselen = ssh->agent_response_len;
6385 s->response = (unsigned char *) r;
6386 if (s->response && s->responselen >= 5 &&
6387 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
6388 s->p = s->response + 5;
6389 s->nkeys = GET_32BIT(s->p);
6393 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
6396 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
6401 sprintf(buf, "Trying Pageant key #%d", s->keyi);
6404 s->pklen = GET_32BIT(s->p);
6406 if (s->publickey_blob &&
6407 s->pklen == s->publickey_bloblen &&
6408 !memcmp(s->p, s->publickey_blob,
6409 s->publickey_bloblen)) {
6410 logevent("This key matches configured key file");
6411 s->tried_pubkey_config = 1;
6413 s->pkblob = (char *)s->p;
6415 s->alglen = GET_32BIT(s->pkblob);
6416 s->alg = s->pkblob + 4;
6417 s->commentlen = GET_32BIT(s->p);
6419 s->commentp = (char *)s->p;
6420 s->p += s->commentlen;
6421 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6422 ssh2_pkt_addstring(s->pktout, s->username);
6423 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6424 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6425 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6426 ssh2_pkt_addstring_start(s->pktout);
6427 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6428 ssh2_pkt_addstring_start(s->pktout);
6429 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6430 ssh2_pkt_send(ssh, s->pktout);
6432 crWaitUntilV(pktin);
6433 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6434 logevent("Key refused");
6438 if (flags & FLAG_VERBOSE) {
6439 c_write_str(ssh, "Authenticating with "
6441 c_write(ssh, s->commentp, s->commentlen);
6442 c_write_str(ssh, "\" from agent\r\n");
6446 * Server is willing to accept the key.
6447 * Construct a SIGN_REQUEST.
6449 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6450 ssh2_pkt_addstring(s->pktout, s->username);
6451 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6452 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6453 ssh2_pkt_addbool(s->pktout, TRUE);
6454 ssh2_pkt_addstring_start(s->pktout);
6455 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6456 ssh2_pkt_addstring_start(s->pktout);
6457 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6459 s->siglen = s->pktout->length - 5 + 4 + 20;
6460 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6462 s->len = 1; /* message type */
6463 s->len += 4 + s->pklen; /* key blob */
6464 s->len += 4 + s->siglen; /* data to sign */
6465 s->len += 4; /* flags */
6466 s->agentreq = snewn(4 + s->len, char);
6467 PUT_32BIT(s->agentreq, s->len);
6468 s->q = s->agentreq + 4;
6469 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
6470 PUT_32BIT(s->q, s->pklen);
6472 memcpy(s->q, s->pkblob, s->pklen);
6474 PUT_32BIT(s->q, s->siglen);
6476 /* Now the data to be signed... */
6477 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6478 PUT_32BIT(s->q, 20);
6481 memcpy(s->q, ssh->v2_session_id, 20);
6483 memcpy(s->q, s->pktout->data + 5,
6484 s->pktout->length - 5);
6485 s->q += s->pktout->length - 5;
6486 /* And finally the (zero) flags word. */
6488 if (!agent_query(s->agentreq, s->len + 4,
6490 ssh_agent_callback, ssh)) {
6494 bombout(("Unexpected data from server"
6495 " while waiting for agent"
6499 } while (pktin || inlen > 0);
6500 vret = ssh->agent_response;
6501 s->retlen = ssh->agent_response_len;
6506 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
6507 logevent("Sending Pageant's response");
6508 ssh2_add_sigblob(ssh, s->pktout,
6509 s->pkblob, s->pklen,
6511 GET_32BIT(s->ret + 5));
6512 ssh2_pkt_send(ssh, s->pktout);
6517 ("Pageant failed to answer challenge");
6528 if (!s->method && s->can_pubkey && s->publickey_blob
6529 && !s->tried_pubkey_config) {
6530 unsigned char *pub_blob;
6531 char *algorithm, *comment;
6534 s->tried_pubkey_config = TRUE;
6536 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6537 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6540 * Try the public key supplied in the configuration.
6542 * First, offer the public blob to see if the server is
6543 * willing to accept it.
6546 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
6551 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6552 ssh2_pkt_addstring(s->pktout, s->username);
6553 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6554 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6555 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6556 ssh2_pkt_addstring(s->pktout, algorithm);
6557 ssh2_pkt_addstring_start(s->pktout);
6558 ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob,
6560 ssh2_pkt_send(ssh, s->pktout);
6561 logevent("Offered public key");
6563 crWaitUntilV(pktin);
6564 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6566 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
6567 continue; /* key refused; give up on it */
6570 logevent("Offer of public key accepted");
6572 * Actually attempt a serious authentication using
6575 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
6576 sprintf(s->pwprompt,
6577 "Passphrase for key \"%.100s\": ",
6583 if (flags & FLAG_VERBOSE) {
6584 c_write_str(ssh, "Authenticating with public key \"");
6585 c_write_str(ssh, comment);
6586 c_write_str(ssh, "\"\r\n");
6588 s->method = AUTH_PUBLICKEY_FILE;
6592 if (!s->method && s->can_keyb_inter && !s->kbd_inter_refused &&
6593 !s->kbd_inter_running) {
6594 s->method = AUTH_KEYBOARD_INTERACTIVE;
6595 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6597 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6598 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
6600 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6601 ssh2_pkt_addstring(s->pktout, s->username);
6602 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6603 ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); /* method */
6604 ssh2_pkt_addstring(s->pktout, ""); /* lang */
6605 ssh2_pkt_addstring(s->pktout, "");
6606 ssh2_pkt_send(ssh, s->pktout);
6608 crWaitUntilV(pktin);
6609 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
6610 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
6612 logevent("Keyboard-interactive authentication refused");
6613 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
6614 s->kbd_inter_refused = TRUE; /* don't try it again */
6618 s->kbd_inter_running = TRUE;
6622 if (s->kbd_inter_running) {
6623 s->method = AUTH_KEYBOARD_INTERACTIVE;
6624 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6626 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6627 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
6629 if (s->curr_prompt == 0) {
6631 * We've got a fresh USERAUTH_INFO_REQUEST.
6632 * Display header data, and start going through
6635 char *name, *inst, *lang;
6636 int name_len, inst_len, lang_len;
6638 ssh_pkt_getstring(pktin, &name, &name_len);
6639 ssh_pkt_getstring(pktin, &inst, &inst_len);
6640 ssh_pkt_getstring(pktin, &lang, &lang_len);
6642 c_write_untrusted(ssh, name, name_len);
6643 c_write_str(ssh, "\r\n");
6646 c_write_untrusted(ssh, inst, inst_len);
6647 c_write_str(ssh, "\r\n");
6649 s->num_prompts = ssh_pkt_getuint32(pktin);
6653 * If there are prompts remaining in the packet,
6654 * display one and get a response.
6656 if (s->curr_prompt < s->num_prompts) {
6660 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
6661 if (prompt_len > 0) {
6662 static const char trunc[] = "<prompt truncated>: ";
6663 static const int prlen = sizeof(s->pwprompt) -
6665 if (prompt_len > prlen) {
6666 memcpy(s->pwprompt, prompt, prlen);
6667 strcpy(s->pwprompt + prlen, trunc);
6669 memcpy(s->pwprompt, prompt, prompt_len);
6670 s->pwprompt[prompt_len] = '\0';
6674 "<server failed to send prompt>: ");
6676 s->echo = ssh2_pkt_getbool(pktin);
6682 if (!s->method && s->can_passwd) {
6683 s->method = AUTH_PASSWORD;
6684 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6685 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
6686 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
6693 if (!ssh_get_line(s->pwprompt, s->password,
6694 sizeof(s->password), TRUE)) {
6696 * get_line failed to get a password (for
6697 * example because one was supplied on the
6698 * command line which has already failed to
6701 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6702 ssh2_pkt_adduint32(s->pktout,SSH2_DISCONNECT_BY_APPLICATION);
6703 ssh2_pkt_addstring(s->pktout, "No more passwords available"
6705 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
6706 ssh2_pkt_send_noqueue(ssh, s->pktout);
6707 logevent("Unable to authenticate");
6708 connection_fatal(ssh->frontend,
6709 "Unable to authenticate");
6710 ssh->close_expected = TRUE;
6711 ssh_closing((Plug)ssh, NULL, 0, 0);
6715 int ret; /* need not be saved across crReturn */
6716 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
6719 setup_userpass_input(ssh, s->password,
6720 sizeof(s->password), s->echo);
6722 crWaitUntilV(!pktin);
6723 ret = process_userpass_input(ssh, in, inlen);
6727 c_write_str(ssh, "\r\n");
6731 if (s->method == AUTH_PUBLICKEY_FILE) {
6733 * We have our passphrase. Now try the actual authentication.
6735 struct ssh2_userkey *key;
6736 const char *error = NULL;
6738 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
6740 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
6741 if (key == SSH2_WRONG_PASSPHRASE) {
6742 c_write_str(ssh, "Wrong passphrase\r\n");
6743 s->tried_pubkey_config = FALSE;
6745 c_write_str(ssh, "Unable to load private key (");
6746 c_write_str(ssh, error);
6747 c_write_str(ssh, ")\r\n");
6748 s->tried_pubkey_config = TRUE;
6750 /* Send a spurious AUTH_NONE to return to the top. */
6751 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6752 ssh2_pkt_addstring(s->pktout, s->username);
6753 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6754 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6755 ssh2_pkt_send(ssh, s->pktout);
6756 s->type = AUTH_TYPE_NONE;
6758 unsigned char *pkblob, *sigblob, *sigdata;
6759 int pkblob_len, sigblob_len, sigdata_len;
6763 * We have loaded the private key and the server
6764 * has announced that it's willing to accept it.
6765 * Hallelujah. Generate a signature and send it.
6767 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6768 ssh2_pkt_addstring(s->pktout, s->username);
6769 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6770 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6771 ssh2_pkt_addbool(s->pktout, TRUE);
6772 ssh2_pkt_addstring(s->pktout, key->alg->name);
6773 pkblob = key->alg->public_blob(key->data, &pkblob_len);
6774 ssh2_pkt_addstring_start(s->pktout);
6775 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len);
6778 * The data to be signed is:
6782 * followed by everything so far placed in the
6785 sigdata_len = s->pktout->length - 5 + 4 + 20;
6786 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6788 sigdata = snewn(sigdata_len, unsigned char);
6790 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6791 PUT_32BIT(sigdata+p, 20);
6794 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
6795 memcpy(sigdata+p, s->pktout->data + 5,
6796 s->pktout->length - 5);
6797 p += s->pktout->length - 5;
6798 assert(p == sigdata_len);
6799 sigblob = key->alg->sign(key->data, (char *)sigdata,
6800 sigdata_len, &sigblob_len);
6801 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
6802 sigblob, sigblob_len);
6807 ssh2_pkt_send(ssh, s->pktout);
6808 s->type = AUTH_TYPE_PUBLICKEY;
6809 key->alg->freekey(key->data);
6811 } else if (s->method == AUTH_PASSWORD) {
6813 * We pad out the password packet to 256 bytes to make
6814 * it harder for an attacker to find the length of the
6817 * Anyone using a password longer than 256 bytes
6818 * probably doesn't have much to worry about from
6819 * people who find out how long their password is!
6821 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6822 s->pktout->forcepad = 256;
6823 ssh2_pkt_addstring(s->pktout, s->username);
6824 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6825 ssh2_pkt_addstring(s->pktout, "password");
6826 ssh2_pkt_addbool(s->pktout, FALSE);
6827 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6828 ssh2_pkt_addstring(s->pktout, s->password);
6829 memset(s->password, 0, sizeof(s->password));
6830 end_log_omission(ssh, s->pktout);
6831 ssh2_pkt_send(ssh, s->pktout);
6832 logevent("Sent password");
6833 s->type = AUTH_TYPE_PASSWORD;
6834 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
6835 if (s->curr_prompt == 0) {
6836 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
6837 s->pktout->forcepad = 256;
6838 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
6840 if (s->need_pw) { /* only add pw if we just got one! */
6841 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6842 ssh2_pkt_addstring(s->pktout, s->password);
6843 memset(s->password, 0, sizeof(s->password));
6844 end_log_omission(ssh, s->pktout);
6847 if (s->curr_prompt >= s->num_prompts) {
6848 ssh2_pkt_send(ssh, s->pktout);
6851 * If there are prompts remaining, we set
6852 * `gotit' so that we won't attempt to get
6853 * another packet. Then we go back round the
6854 * loop and will end up retrieving another
6855 * prompt out of the existing packet. Funky or
6860 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6862 c_write_str(ssh, "No supported authentication methods"
6863 " left to try!\r\n");
6864 logevent("No supported authentications offered."
6866 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6867 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
6868 ssh2_pkt_addstring(s->pktout, "No supported authentication"
6869 " methods available");
6870 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
6871 ssh2_pkt_send_noqueue(ssh, s->pktout);
6872 ssh->close_expected = TRUE;
6873 ssh_closing((Plug)ssh, NULL, 0, 0);
6877 } while (!s->we_are_in);
6880 * Now we're authenticated for the connection protocol. The
6881 * connection protocol will automatically have started at this
6882 * point; there's no need to send SERVICE_REQUEST.
6885 ssh->channels = newtree234(ssh_channelcmp);
6888 * Set up handlers for some connection protocol messages, so we
6889 * don't have to handle them repeatedly in this coroutine.
6891 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
6892 ssh2_msg_channel_window_adjust;
6893 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
6894 ssh2_msg_global_request;
6897 * Create the main session channel.
6899 if (!ssh->cfg.ssh_no_shell) {
6900 ssh->mainchan = snew(struct ssh_channel);
6901 ssh->mainchan->ssh = ssh;
6902 ssh->mainchan->localid = alloc_channel_id(ssh);
6903 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
6904 ssh2_pkt_addstring(s->pktout, "session");
6905 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
6906 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
6907 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
6908 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
6909 ssh2_pkt_send(ssh, s->pktout);
6910 crWaitUntilV(pktin);
6911 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
6912 bombout(("Server refused to open a session"));
6914 /* FIXME: error data comes back in FAILURE packet */
6916 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
6917 bombout(("Server's channel confirmation cited wrong channel"));
6920 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
6921 ssh->mainchan->halfopen = FALSE;
6922 ssh->mainchan->type = CHAN_MAINSESSION;
6923 ssh->mainchan->closes = 0;
6924 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6925 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
6926 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
6927 add234(ssh->channels, ssh->mainchan);
6928 update_specials_menu(ssh->frontend);
6929 logevent("Opened channel for session");
6931 ssh->mainchan = NULL;
6934 * Now we have a channel, make dispatch table entries for
6935 * general channel-based messages.
6937 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
6938 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
6939 ssh2_msg_channel_data;
6940 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
6941 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
6942 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
6943 ssh2_msg_channel_open_confirmation;
6944 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
6945 ssh2_msg_channel_open_failure;
6946 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
6947 ssh2_msg_channel_request;
6948 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
6949 ssh2_msg_channel_open;
6952 * Potentially enable X11 forwarding.
6954 if (ssh->mainchan && ssh->cfg.x11_forward) {
6955 char proto[20], data[64];
6956 logevent("Requesting X11 forwarding");
6957 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
6958 data, sizeof(data), ssh->cfg.x11_auth);
6959 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
6960 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6961 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6962 ssh2_pkt_addstring(s->pktout, "x11-req");
6963 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6964 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
6965 ssh2_pkt_addstring(s->pktout, proto);
6966 ssh2_pkt_addstring(s->pktout, data);
6967 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
6968 ssh2_pkt_send(ssh, s->pktout);
6970 crWaitUntilV(pktin);
6972 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6973 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6974 bombout(("Unexpected response to X11 forwarding request:"
6975 " packet type %d", pktin->type));
6978 logevent("X11 forwarding refused");
6980 logevent("X11 forwarding enabled");
6981 ssh->X11_fwd_enabled = TRUE;
6986 * Enable port forwardings.
6988 ssh_setup_portfwd(ssh, &ssh->cfg);
6991 * Potentially enable agent forwarding.
6993 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
6994 logevent("Requesting OpenSSH-style agent forwarding");
6995 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6996 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6997 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
6998 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6999 ssh2_pkt_send(ssh, s->pktout);
7001 crWaitUntilV(pktin);
7003 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7004 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7005 bombout(("Unexpected response to agent forwarding request:"
7006 " packet type %d", pktin->type));
7009 logevent("Agent forwarding refused");
7011 logevent("Agent forwarding enabled");
7012 ssh->agentfwd_enabled = TRUE;
7017 * Now allocate a pty for the session.
7019 if (ssh->mainchan && !ssh->cfg.nopty) {
7020 /* Unpick the terminal-speed string. */
7021 /* XXX perhaps we should allow no speeds to be sent. */
7022 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
7023 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
7024 /* Build the pty request. */
7025 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7026 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
7027 ssh2_pkt_addstring(s->pktout, "pty-req");
7028 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7029 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
7030 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
7031 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
7032 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
7033 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
7034 ssh2_pkt_addstring_start(s->pktout);
7035 ssh2_pkt_addbyte(s->pktout, 128); /* TTY_OP_ISPEED */
7036 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
7037 ssh2_pkt_addbyte(s->pktout, 129); /* TTY_OP_OSPEED */
7038 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
7039 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
7040 ssh2_pkt_send(ssh, s->pktout);
7041 ssh->state = SSH_STATE_INTERMED;
7043 crWaitUntilV(pktin);
7045 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7046 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7047 bombout(("Unexpected response to pty request:"
7048 " packet type %d", pktin->type));
7051 c_write_str(ssh, "Server refused to allocate pty\r\n");
7052 ssh->editing = ssh->echoing = 1;
7054 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
7055 ssh->ospeed, ssh->ispeed);
7058 ssh->editing = ssh->echoing = 1;
7062 * Send environment variables.
7064 * Simplest thing here is to send all the requests at once, and
7065 * then wait for a whole bunch of successes or failures.
7067 if (ssh->mainchan && *ssh->cfg.environmt) {
7068 char *e = ssh->cfg.environmt;
7069 char *var, *varend, *val;
7075 while (*e && *e != '\t') e++;
7077 if (*e == '\t') e++;
7082 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7083 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7084 ssh2_pkt_addstring(s->pktout, "env");
7085 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7086 ssh2_pkt_addstring_start(s->pktout);
7087 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
7088 ssh2_pkt_addstring(s->pktout, val);
7089 ssh2_pkt_send(ssh, s->pktout);
7094 logeventf(ssh, "Sent %d environment variables", s->num_env);
7097 s->env_left = s->num_env;
7099 while (s->env_left > 0) {
7100 crWaitUntilV(pktin);
7102 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7103 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7104 bombout(("Unexpected response to environment request:"
7105 " packet type %d", pktin->type));
7115 if (s->env_ok == s->num_env) {
7116 logevent("All environment variables successfully set");
7117 } else if (s->env_ok == 0) {
7118 logevent("All environment variables refused");
7119 c_write_str(ssh, "Server refused to set environment variables\r\n");
7121 logeventf(ssh, "%d environment variables refused",
7122 s->num_env - s->env_ok);
7123 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7128 * Start a shell or a remote command. We may have to attempt
7129 * this twice if the config data has provided a second choice
7132 if (ssh->mainchan) while (1) {
7136 if (ssh->fallback_cmd) {
7137 subsys = ssh->cfg.ssh_subsys2;
7138 cmd = ssh->cfg.remote_cmd_ptr2;
7140 subsys = ssh->cfg.ssh_subsys;
7141 cmd = ssh->cfg.remote_cmd_ptr;
7144 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7145 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
7147 ssh2_pkt_addstring(s->pktout, "subsystem");
7148 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7149 ssh2_pkt_addstring(s->pktout, cmd);
7151 ssh2_pkt_addstring(s->pktout, "exec");
7152 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7153 ssh2_pkt_addstring(s->pktout, cmd);
7155 ssh2_pkt_addstring(s->pktout, "shell");
7156 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7158 ssh2_pkt_send(ssh, s->pktout);
7160 crWaitUntilV(pktin);
7162 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7163 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7164 bombout(("Unexpected response to shell/command request:"
7165 " packet type %d", pktin->type));
7169 * We failed to start the command. If this is the
7170 * fallback command, we really are finished; if it's
7171 * not, and if the fallback command exists, try falling
7172 * back to it before complaining.
7174 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
7175 logevent("Primary command failed; attempting fallback");
7176 ssh->fallback_cmd = TRUE;
7179 bombout(("Server refused to start a shell/command"));
7182 logevent("Started a shell/command");
7187 ssh->state = SSH_STATE_SESSION;
7188 if (ssh->size_needed)
7189 ssh_size(ssh, ssh->term_width, ssh->term_height);
7190 if (ssh->eof_needed)
7191 ssh_special(ssh, TS_EOF);
7197 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
7202 s->try_send = FALSE;
7206 * _All_ the connection-layer packets we expect to
7207 * receive are now handled by the dispatch table.
7208 * Anything that reaches here must be bogus.
7211 bombout(("Strange packet received: type %d", pktin->type));
7213 } else if (ssh->mainchan) {
7215 * We have spare data. Add it to the channel buffer.
7217 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
7222 struct ssh_channel *c;
7224 * Try to send data on all channels if we can.
7226 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
7229 continue; /* don't send on closing channels */
7230 bufsize = ssh2_try_send(c);
7233 case CHAN_MAINSESSION:
7234 /* stdin need not receive an unthrottle
7235 * notification since it will be polled */
7238 x11_unthrottle(c->u.x11.s);
7241 /* agent sockets are request/response and need no
7242 * buffer management */
7245 pfd_unthrottle(c->u.pfd.s);
7257 * Handlers for SSH2 messages that might arrive at any moment.
7259 void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
7261 /* log reason code in disconnect message */
7263 int nowlen, reason, msglen;
7265 reason = ssh_pkt_getuint32(pktin);
7266 ssh_pkt_getstring(pktin, &msg, &msglen);
7268 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
7269 buf = dupprintf("Received disconnect message (%s)",
7270 ssh2_disconnect_reasons[reason]);
7272 buf = dupprintf("Received disconnect message (unknown"
7273 " type %d)", reason);
7277 buf = dupprintf("Disconnection message text: %n%.*s",
7278 &nowlen, msglen, msg);
7280 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
7282 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
7283 ssh2_disconnect_reasons[reason] : "unknown",
7288 void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
7290 /* log the debug message */
7295 /* XXX maybe we should actually take notice of this */
7296 always_display = ssh2_pkt_getbool(pktin);
7297 ssh_pkt_getstring(pktin, &msg, &msglen);
7299 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
7304 void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
7306 struct Packet *pktout;
7307 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
7308 ssh2_pkt_adduint32(pktout, pktin->sequence);
7310 * UNIMPLEMENTED messages MUST appear in the same order as the
7311 * messages they respond to. Hence, never queue them.
7313 ssh2_pkt_send_noqueue(ssh, pktout);
7317 * Handle the top-level SSH2 protocol.
7319 static void ssh2_protocol_setup(Ssh ssh)
7324 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
7326 for (i = 0; i < 256; i++)
7327 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
7330 * Any message we actually understand, we set to NULL so that
7331 * the coroutines will get it.
7333 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
7334 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
7335 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
7336 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
7337 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
7338 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
7339 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
7340 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
7341 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
7342 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
7343 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
7344 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
7345 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
7346 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
7347 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7348 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
7349 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
7350 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
7351 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
7352 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
7353 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
7354 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
7355 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
7356 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
7357 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
7358 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
7359 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
7360 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
7361 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
7362 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
7363 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
7364 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
7365 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
7368 * These special message types we install handlers for.
7370 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
7371 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with ssh1 */
7372 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
7375 static void ssh2_timer(void *ctx, long now)
7379 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
7380 now - ssh->next_rekey >= 0) {
7381 do_ssh2_transport(ssh, "timeout", -1, NULL);
7385 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
7386 struct Packet *pktin)
7388 unsigned char *in = (unsigned char *)vin;
7389 if (ssh->state == SSH_STATE_CLOSED)
7393 ssh->incoming_data_size += pktin->encrypted_len;
7394 if (!ssh->kex_in_progress &&
7395 ssh->max_data_size != 0 &&
7396 ssh->incoming_data_size > ssh->max_data_size)
7397 do_ssh2_transport(ssh, "too much data received", -1, NULL);
7400 if (pktin && ssh->packet_dispatch[pktin->type]) {
7401 ssh->packet_dispatch[pktin->type](ssh, pktin);
7405 if (!ssh->protocol_initial_phase_done ||
7406 (pktin && pktin->type >= 20 && pktin->type < 50)) {
7407 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
7408 !ssh->protocol_initial_phase_done) {
7409 ssh->protocol_initial_phase_done = TRUE;
7411 * Allow authconn to initialise itself.
7413 do_ssh2_authconn(ssh, NULL, 0, NULL);
7416 do_ssh2_authconn(ssh, in, inlen, pktin);
7421 * Called to set up the connection.
7423 * Returns an error message, or NULL on success.
7425 static const char *ssh_init(void *frontend_handle, void **backend_handle,
7427 char *host, int port, char **realhost, int nodelay,
7433 ssh = snew(struct ssh_tag);
7434 ssh->cfg = *cfg; /* STRUCTURE COPY */
7435 ssh->version = 0; /* when not ready yet */
7438 ssh->v1_cipher_ctx = NULL;
7439 ssh->crcda_ctx = NULL;
7440 ssh->cscipher = NULL;
7441 ssh->cs_cipher_ctx = NULL;
7442 ssh->sccipher = NULL;
7443 ssh->sc_cipher_ctx = NULL;
7445 ssh->cs_mac_ctx = NULL;
7447 ssh->sc_mac_ctx = NULL;
7449 ssh->cs_comp_ctx = NULL;
7451 ssh->sc_comp_ctx = NULL;
7453 ssh->kex_ctx = NULL;
7454 ssh->hostkey = NULL;
7456 ssh->close_expected = FALSE;
7457 ssh->state = SSH_STATE_PREPACKET;
7458 ssh->size_needed = FALSE;
7459 ssh->eof_needed = FALSE;
7462 ssh->deferred_send_data = NULL;
7463 ssh->deferred_len = 0;
7464 ssh->deferred_size = 0;
7465 ssh->fallback_cmd = 0;
7467 ssh->x11auth = NULL;
7468 ssh->v1_compressing = FALSE;
7469 ssh->v2_outgoing_sequence = 0;
7470 ssh->ssh1_rdpkt_crstate = 0;
7471 ssh->ssh2_rdpkt_crstate = 0;
7472 ssh->do_ssh_init_crstate = 0;
7473 ssh->ssh_gotdata_crstate = 0;
7474 ssh->do_ssh1_connection_crstate = 0;
7475 ssh->do_ssh1_login_crstate = 0;
7476 ssh->do_ssh2_transport_crstate = 0;
7477 ssh->do_ssh2_authconn_crstate = 0;
7478 ssh->do_ssh_init_state = NULL;
7479 ssh->do_ssh1_login_state = NULL;
7480 ssh->do_ssh2_transport_state = NULL;
7481 ssh->do_ssh2_authconn_state = NULL;
7482 ssh->mainchan = NULL;
7483 ssh->throttled_all = 0;
7484 ssh->v1_stdout_throttling = 0;
7486 ssh->queuelen = ssh->queuesize = 0;
7487 ssh->queueing = FALSE;
7488 ssh->qhead = ssh->qtail = NULL;
7489 ssh->deferred_rekey_reason = NULL;
7491 *backend_handle = ssh;
7494 if (crypto_startup() == 0)
7495 return "Microsoft high encryption pack not installed!";
7498 ssh->frontend = frontend_handle;
7499 ssh->term_width = ssh->cfg.width;
7500 ssh->term_height = ssh->cfg.height;
7502 ssh->channels = NULL;
7503 ssh->rportfwds = NULL;
7504 ssh->portfwds = NULL;
7509 ssh->v1_throttle_count = 0;
7510 ssh->overall_bufsize = 0;
7511 ssh->fallback_cmd = 0;
7513 ssh->protocol = NULL;
7515 ssh->protocol_initial_phase_done = FALSE;
7519 ssh->incoming_data_size = ssh->outgoing_data_size =
7520 ssh->deferred_data_size = 0L;
7521 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
7522 ssh->kex_in_progress = FALSE;
7524 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
7533 static void ssh_free(void *handle)
7535 Ssh ssh = (Ssh) handle;
7536 struct ssh_channel *c;
7537 struct ssh_rportfwd *pf;
7539 if (ssh->v1_cipher_ctx)
7540 ssh->cipher->free_context(ssh->v1_cipher_ctx);
7541 if (ssh->cs_cipher_ctx)
7542 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7543 if (ssh->sc_cipher_ctx)
7544 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7545 if (ssh->cs_mac_ctx)
7546 ssh->csmac->free_context(ssh->cs_mac_ctx);
7547 if (ssh->sc_mac_ctx)
7548 ssh->scmac->free_context(ssh->sc_mac_ctx);
7549 if (ssh->cs_comp_ctx) {
7551 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7553 zlib_compress_cleanup(ssh->cs_comp_ctx);
7555 if (ssh->sc_comp_ctx) {
7557 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7559 zlib_decompress_cleanup(ssh->sc_comp_ctx);
7562 dh_cleanup(ssh->kex_ctx);
7563 sfree(ssh->savedhost);
7565 while (ssh->queuelen-- > 0)
7566 ssh_free_packet(ssh->queue[ssh->queuelen]);
7569 while (ssh->qhead) {
7570 struct queued_handler *qh = ssh->qhead;
7571 ssh->qhead = qh->next;
7574 ssh->qhead = ssh->qtail = NULL;
7576 if (ssh->channels) {
7577 while ((c = delpos234(ssh->channels, 0)) != NULL) {
7580 if (c->u.x11.s != NULL)
7581 x11_close(c->u.x11.s);
7584 if (c->u.pfd.s != NULL)
7585 pfd_close(c->u.pfd.s);
7590 freetree234(ssh->channels);
7591 ssh->channels = NULL;
7594 if (ssh->rportfwds) {
7595 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
7597 freetree234(ssh->rportfwds);
7598 ssh->rportfwds = NULL;
7600 sfree(ssh->deferred_send_data);
7602 x11_free_auth(ssh->x11auth);
7603 sfree(ssh->do_ssh_init_state);
7604 sfree(ssh->do_ssh1_login_state);
7605 sfree(ssh->do_ssh2_transport_state);
7606 sfree(ssh->do_ssh2_authconn_state);
7607 if (ssh->crcda_ctx) {
7608 crcda_free_context(ssh->crcda_ctx);
7609 ssh->crcda_ctx = NULL;
7612 ssh_do_close(ssh, TRUE);
7613 expire_timer_context(ssh);
7615 pinger_free(ssh->pinger);
7622 * Reconfigure the SSH backend.
7624 static void ssh_reconfig(void *handle, Config *cfg)
7626 Ssh ssh = (Ssh) handle;
7627 char *rekeying = NULL, rekey_mandatory = FALSE;
7628 unsigned long old_max_data_size;
7630 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
7631 ssh_setup_portfwd(ssh, cfg);
7633 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
7634 cfg->ssh_rekey_time != 0) {
7635 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
7636 long now = GETTICKCOUNT();
7638 if (new_next - now < 0) {
7639 rekeying = "timeout shortened";
7641 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
7645 old_max_data_size = ssh->max_data_size;
7646 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
7647 if (old_max_data_size != ssh->max_data_size &&
7648 ssh->max_data_size != 0) {
7649 if (ssh->outgoing_data_size > ssh->max_data_size ||
7650 ssh->incoming_data_size > ssh->max_data_size)
7651 rekeying = "data limit lowered";
7654 if (ssh->cfg.compression != cfg->compression) {
7655 rekeying = "compression setting changed";
7656 rekey_mandatory = TRUE;
7659 if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
7660 memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
7661 sizeof(ssh->cfg.ssh_cipherlist))) {
7662 rekeying = "cipher settings changed";
7663 rekey_mandatory = TRUE;
7666 ssh->cfg = *cfg; /* STRUCTURE COPY */
7669 if (!ssh->kex_in_progress) {
7670 do_ssh2_transport(ssh, rekeying, -1, NULL);
7671 } else if (rekey_mandatory) {
7672 ssh->deferred_rekey_reason = rekeying;
7678 * Called to send data down the Telnet connection.
7680 static int ssh_send(void *handle, char *buf, int len)
7682 Ssh ssh = (Ssh) handle;
7684 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
7687 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
7689 return ssh_sendbuffer(ssh);
7693 * Called to query the current amount of buffered stdin data.
7695 static int ssh_sendbuffer(void *handle)
7697 Ssh ssh = (Ssh) handle;
7700 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
7704 * If the SSH socket itself has backed up, add the total backup
7705 * size on that to any individual buffer on the stdin channel.
7708 if (ssh->throttled_all)
7709 override_value = ssh->overall_bufsize;
7711 if (ssh->version == 1) {
7712 return override_value;
7713 } else if (ssh->version == 2) {
7714 if (!ssh->mainchan || ssh->mainchan->closes > 0)
7715 return override_value;
7717 return (override_value +
7718 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
7725 * Called to set the size of the window from SSH's POV.
7727 static void ssh_size(void *handle, int width, int height)
7729 Ssh ssh = (Ssh) handle;
7730 struct Packet *pktout;
7732 ssh->term_width = width;
7733 ssh->term_height = height;
7735 switch (ssh->state) {
7736 case SSH_STATE_BEFORE_SIZE:
7737 case SSH_STATE_PREPACKET:
7738 case SSH_STATE_CLOSED:
7739 break; /* do nothing */
7740 case SSH_STATE_INTERMED:
7741 ssh->size_needed = TRUE; /* buffer for later */
7743 case SSH_STATE_SESSION:
7744 if (!ssh->cfg.nopty) {
7745 if (ssh->version == 1) {
7746 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
7747 PKT_INT, ssh->term_height,
7748 PKT_INT, ssh->term_width,
7749 PKT_INT, 0, PKT_INT, 0, PKT_END);
7750 } else if (ssh->mainchan) {
7751 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7752 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7753 ssh2_pkt_addstring(pktout, "window-change");
7754 ssh2_pkt_addbool(pktout, 0);
7755 ssh2_pkt_adduint32(pktout, ssh->term_width);
7756 ssh2_pkt_adduint32(pktout, ssh->term_height);
7757 ssh2_pkt_adduint32(pktout, 0);
7758 ssh2_pkt_adduint32(pktout, 0);
7759 ssh2_pkt_send(ssh, pktout);
7767 * Return a list of the special codes that make sense in this
7770 static const struct telnet_special *ssh_get_specials(void *handle)
7772 static const struct telnet_special ssh1_ignore_special[] = {
7773 {"IGNORE message", TS_NOP}
7775 static const struct telnet_special ssh2_transport_specials[] = {
7776 {"IGNORE message", TS_NOP},
7777 {"Repeat key exchange", TS_REKEY},
7779 static const struct telnet_special ssh2_session_specials[] = {
7782 /* These are the signal names defined by draft-ietf-secsh-connect-23.
7783 * They include all the ISO C signals, but are a subset of the POSIX
7784 * required signals. */
7785 {"SIGINT (Interrupt)", TS_SIGINT},
7786 {"SIGTERM (Terminate)", TS_SIGTERM},
7787 {"SIGKILL (Kill)", TS_SIGKILL},
7788 {"SIGQUIT (Quit)", TS_SIGQUIT},
7789 {"SIGHUP (Hangup)", TS_SIGHUP},
7790 {"More signals", TS_SUBMENU},
7791 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
7792 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
7793 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
7794 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
7797 static const struct telnet_special specials_end[] = {
7800 /* XXX review this length for any changes: */
7801 static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
7802 lenof(ssh2_session_specials) +
7803 lenof(specials_end)];
7804 Ssh ssh = (Ssh) handle;
7806 #define ADD_SPECIALS(name) \
7808 assert((i + lenof(name)) <= lenof(ssh_specials)); \
7809 memcpy(&ssh_specials[i], name, sizeof name); \
7813 if (ssh->version == 1) {
7814 /* Don't bother offering IGNORE if we've decided the remote
7815 * won't cope with it, since we wouldn't bother sending it if
7817 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7818 ADD_SPECIALS(ssh1_ignore_special);
7819 } else if (ssh->version == 2) {
7820 ADD_SPECIALS(ssh2_transport_specials);
7822 ADD_SPECIALS(ssh2_session_specials);
7823 } /* else we're not ready yet */
7826 ADD_SPECIALS(specials_end);
7827 return ssh_specials;
7835 * Send Telnet special codes. TS_EOF is useful for `plink', so you
7836 * can send an EOF and collect resulting output (e.g. `plink
7839 static void ssh_special(void *handle, Telnet_Special code)
7841 Ssh ssh = (Ssh) handle;
7842 struct Packet *pktout;
7844 if (code == TS_EOF) {
7845 if (ssh->state != SSH_STATE_SESSION) {
7847 * Buffer the EOF in case we are pre-SESSION, so we can
7848 * send it as soon as we reach SESSION.
7851 ssh->eof_needed = TRUE;
7854 if (ssh->version == 1) {
7855 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
7856 } else if (ssh->mainchan) {
7857 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
7858 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7859 ssh2_pkt_send(ssh, pktout);
7861 logevent("Sent EOF message");
7862 } else if (code == TS_PING || code == TS_NOP) {
7863 if (ssh->state == SSH_STATE_CLOSED
7864 || ssh->state == SSH_STATE_PREPACKET) return;
7865 if (ssh->version == 1) {
7866 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7867 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
7869 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
7870 ssh2_pkt_addstring_start(pktout);
7871 ssh2_pkt_send_noqueue(ssh, pktout);
7873 } else if (code == TS_REKEY) {
7874 if (!ssh->kex_in_progress && ssh->version == 2) {
7875 do_ssh2_transport(ssh, "at user request", -1, NULL);
7877 } else if (code == TS_BRK) {
7878 if (ssh->state == SSH_STATE_CLOSED
7879 || ssh->state == SSH_STATE_PREPACKET) return;
7880 if (ssh->version == 1) {
7881 logevent("Unable to send BREAK signal in SSH1");
7882 } else if (ssh->mainchan) {
7883 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7884 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7885 ssh2_pkt_addstring(pktout, "break");
7886 ssh2_pkt_addbool(pktout, 0);
7887 ssh2_pkt_adduint32(pktout, 0); /* default break length */
7888 ssh2_pkt_send(ssh, pktout);
7891 /* Is is a POSIX signal? */
7892 char *signame = NULL;
7893 if (code == TS_SIGABRT) signame = "ABRT";
7894 if (code == TS_SIGALRM) signame = "ALRM";
7895 if (code == TS_SIGFPE) signame = "FPE";
7896 if (code == TS_SIGHUP) signame = "HUP";
7897 if (code == TS_SIGILL) signame = "ILL";
7898 if (code == TS_SIGINT) signame = "INT";
7899 if (code == TS_SIGKILL) signame = "KILL";
7900 if (code == TS_SIGPIPE) signame = "PIPE";
7901 if (code == TS_SIGQUIT) signame = "QUIT";
7902 if (code == TS_SIGSEGV) signame = "SEGV";
7903 if (code == TS_SIGTERM) signame = "TERM";
7904 if (code == TS_SIGUSR1) signame = "USR1";
7905 if (code == TS_SIGUSR2) signame = "USR2";
7906 /* The SSH-2 protocol does in principle support arbitrary named
7907 * signals, including signame@domain, but we don't support those. */
7909 /* It's a signal. */
7910 if (ssh->version == 2 && ssh->mainchan) {
7911 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7912 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7913 ssh2_pkt_addstring(pktout, "signal");
7914 ssh2_pkt_addbool(pktout, 0);
7915 ssh2_pkt_addstring(pktout, signame);
7916 ssh2_pkt_send(ssh, pktout);
7917 logeventf(ssh, "Sent signal SIG%s", signame);
7920 /* Never heard of it. Do nothing */
7925 void *new_sock_channel(void *handle, Socket s)
7927 Ssh ssh = (Ssh) handle;
7928 struct ssh_channel *c;
7929 c = snew(struct ssh_channel);
7934 c->localid = alloc_channel_id(ssh);
7936 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
7938 bufchain_init(&c->v.v2.outbuffer);
7939 add234(ssh->channels, c);
7945 * This is called when stdout/stderr (the entity to which
7946 * from_backend sends data) manages to clear some backlog.
7948 static void ssh_unthrottle(void *handle, int bufsize)
7950 Ssh ssh = (Ssh) handle;
7951 if (ssh->version == 1) {
7952 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
7953 ssh->v1_stdout_throttling = 0;
7954 ssh1_throttle(ssh, -1);
7957 if (ssh->mainchan && ssh->mainchan->closes == 0)
7958 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
7962 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
7964 struct ssh_channel *c = (struct ssh_channel *)channel;
7966 struct Packet *pktout;
7968 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
7970 if (ssh->version == 1) {
7971 send_packet(ssh, SSH1_MSG_PORT_OPEN,
7972 PKT_INT, c->localid,
7975 /* PKT_STR, <org:orgport>, */
7978 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7979 ssh2_pkt_addstring(pktout, "direct-tcpip");
7980 ssh2_pkt_adduint32(pktout, c->localid);
7981 c->v.v2.locwindow = OUR_V2_WINSIZE;
7982 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7983 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7984 ssh2_pkt_addstring(pktout, hostname);
7985 ssh2_pkt_adduint32(pktout, port);
7987 * We make up values for the originator data; partly it's
7988 * too much hassle to keep track, and partly I'm not
7989 * convinced the server should be told details like that
7990 * about my local network configuration.
7992 ssh2_pkt_addstring(pktout, "client-side-connection");
7993 ssh2_pkt_adduint32(pktout, 0);
7994 ssh2_pkt_send(ssh, pktout);
7998 static Socket ssh_socket(void *handle)
8000 Ssh ssh = (Ssh) handle;
8004 static int ssh_sendok(void *handle)
8006 Ssh ssh = (Ssh) handle;
8007 return ssh->send_ok;
8010 static int ssh_ldisc(void *handle, int option)
8012 Ssh ssh = (Ssh) handle;
8013 if (option == LD_ECHO)
8014 return ssh->echoing;
8015 if (option == LD_EDIT)
8016 return ssh->editing;
8020 static void ssh_provide_ldisc(void *handle, void *ldisc)
8022 Ssh ssh = (Ssh) handle;
8026 static void ssh_provide_logctx(void *handle, void *logctx)
8028 Ssh ssh = (Ssh) handle;
8029 ssh->logctx = logctx;
8032 static int ssh_return_exitcode(void *handle)
8034 Ssh ssh = (Ssh) handle;
8038 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
8042 * cfg_info for SSH is the currently running version of the
8043 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
8045 static int ssh_cfg_info(void *handle)
8047 Ssh ssh = (Ssh) handle;
8048 return ssh->version;
8052 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
8053 * that fails. This variable is the means by which scp.c can reach
8054 * into the SSH code and find out which one it got.
8056 extern int ssh_fallback_cmd(void *handle)
8058 Ssh ssh = (Ssh) handle;
8059 return ssh->fallback_cmd;
8062 Backend ssh_backend = {
8072 ssh_return_exitcode,