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 callbacks.
731 void *agent_response;
732 int agent_response_len;
736 * The SSH connection can be set as `frozen', meaning we are
737 * not currently accepting incoming data from the network. This
738 * is slightly more serious than setting the _socket_ as
739 * frozen, because we may already have had data passed to us
740 * from the network which we need to delay processing until
741 * after the freeze is lifted, so we also need a bufchain to
745 bufchain queued_incoming_data;
748 * Dispatch table for packet types that we may have to deal
751 handler_fn_t packet_dispatch[256];
754 * Queues of one-off handler functions for success/failure
755 * indications from a request.
757 struct queued_handler *qhead, *qtail;
760 * This module deals with sending keepalives.
765 * Track incoming and outgoing data sizes and time, for
768 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
769 unsigned long max_data_size;
771 long next_rekey, last_rekey;
772 char *deferred_rekey_reason; /* points to STATIC string; don't free */
775 #define logevent(s) logevent(ssh->frontend, s)
777 /* logevent, only printf-formatted. */
778 static void logeventf(Ssh ssh, const char *fmt, ...)
784 buf = dupvprintf(fmt, ap);
790 #define bombout(msg) \
792 char *text = dupprintf msg; \
793 ssh_do_close(ssh, FALSE); \
795 connection_fatal(ssh->frontend, "%s", text); \
799 /* Functions to leave bits out of the SSH packet log file. */
801 static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
803 if (ssh->cfg.logomitpass)
804 pkt->logmode = blanktype;
807 static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
809 if (ssh->cfg.logomitdata)
810 pkt->logmode = blanktype;
813 static void end_log_omission(Ssh ssh, struct Packet *pkt)
815 pkt->logmode = PKTLOG_EMIT;
818 static int ssh_channelcmp(void *av, void *bv)
820 struct ssh_channel *a = (struct ssh_channel *) av;
821 struct ssh_channel *b = (struct ssh_channel *) bv;
822 if (a->localid < b->localid)
824 if (a->localid > b->localid)
828 static int ssh_channelfind(void *av, void *bv)
830 unsigned *a = (unsigned *) av;
831 struct ssh_channel *b = (struct ssh_channel *) bv;
839 static int ssh_rportcmp_ssh1(void *av, void *bv)
841 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
842 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
844 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
845 return i < 0 ? -1 : +1;
846 if (a->dport > b->dport)
848 if (a->dport < b->dport)
853 static int ssh_rportcmp_ssh2(void *av, void *bv)
855 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
856 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
858 if (a->sport > b->sport)
860 if (a->sport < b->sport)
866 * Special form of strcmp which can cope with NULL inputs. NULL is
867 * defined to sort before even the empty string.
869 static int nullstrcmp(const char *a, const char *b)
871 if (a == NULL && b == NULL)
880 static int ssh_portcmp(void *av, void *bv)
882 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
883 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
885 if (a->type > b->type)
887 if (a->type < b->type)
889 if (a->addressfamily > b->addressfamily)
891 if (a->addressfamily < b->addressfamily)
893 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
894 return i < 0 ? -1 : +1;
895 if (a->sport > b->sport)
897 if (a->sport < b->sport)
899 if (a->type != 'D') {
900 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
901 return i < 0 ? -1 : +1;
902 if (a->dport > b->dport)
904 if (a->dport < b->dport)
910 static int alloc_channel_id(Ssh ssh)
912 const unsigned CHANNEL_NUMBER_OFFSET = 256;
913 unsigned low, high, mid;
915 struct ssh_channel *c;
918 * First-fit allocation of channel numbers: always pick the
919 * lowest unused one. To do this, binary-search using the
920 * counted B-tree to find the largest channel ID which is in a
921 * contiguous sequence from the beginning. (Precisely
922 * everything in that sequence must have ID equal to its tree
923 * index plus CHANNEL_NUMBER_OFFSET.)
925 tsize = count234(ssh->channels);
929 while (high - low > 1) {
930 mid = (high + low) / 2;
931 c = index234(ssh->channels, mid);
932 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
933 low = mid; /* this one is fine */
935 high = mid; /* this one is past it */
938 * Now low points to either -1, or the tree index of the
939 * largest ID in the initial sequence.
942 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
943 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
945 return low + 1 + CHANNEL_NUMBER_OFFSET;
948 static void c_write(Ssh ssh, const char *buf, int len)
950 if ((flags & FLAG_STDERR)) {
952 for (i = 0; i < len; i++)
954 fputc(buf[i], stderr);
957 from_backend(ssh->frontend, 1, buf, len);
960 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
963 for (i = 0; i < len; i++) {
965 c_write(ssh, "\r\n", 2);
966 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
967 c_write(ssh, buf + i, 1);
971 static void c_write_str(Ssh ssh, const char *buf)
973 c_write(ssh, buf, strlen(buf));
976 static void ssh_free_packet(struct Packet *pkt)
981 static struct Packet *ssh_new_packet(void)
983 struct Packet *pkt = snew(struct Packet);
987 pkt->logmode = PKTLOG_EMIT;
995 * Collect incoming data in the incoming packet buffer.
996 * Decipher and verify the packet when it is completely read.
997 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
998 * Update the *data and *datalen variables.
999 * Return a Packet structure when a packet is completed.
1001 static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1003 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
1005 crBegin(ssh->ssh1_rdpkt_crstate);
1007 st->pktin = ssh_new_packet();
1009 st->pktin->type = 0;
1010 st->pktin->length = 0;
1012 for (st->i = st->len = 0; st->i < 4; st->i++) {
1013 while ((*datalen) == 0)
1015 st->len = (st->len << 8) + **data;
1016 (*data)++, (*datalen)--;
1019 st->pad = 8 - (st->len % 8);
1020 st->biglen = st->len + st->pad;
1021 st->pktin->length = st->len - 5;
1023 if (st->biglen < 0) {
1024 bombout(("Extremely large packet length from server suggests"
1025 " data stream corruption"));
1026 ssh_free_packet(st->pktin);
1030 st->pktin->maxlen = st->biglen;
1031 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1033 st->to_read = st->biglen;
1034 st->p = st->pktin->data;
1035 while (st->to_read > 0) {
1036 st->chunk = st->to_read;
1037 while ((*datalen) == 0)
1039 if (st->chunk > (*datalen))
1040 st->chunk = (*datalen);
1041 memcpy(st->p, *data, st->chunk);
1043 *datalen -= st->chunk;
1045 st->to_read -= st->chunk;
1048 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1049 st->biglen, NULL)) {
1050 bombout(("Network attack (CRC compensation) detected!"));
1051 ssh_free_packet(st->pktin);
1056 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1058 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1059 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1060 if (st->gotcrc != st->realcrc) {
1061 bombout(("Incorrect CRC received on packet"));
1062 ssh_free_packet(st->pktin);
1066 st->pktin->body = st->pktin->data + st->pad + 1;
1067 st->pktin->savedpos = 0;
1069 if (ssh->v1_compressing) {
1070 unsigned char *decompblk;
1072 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1073 st->pktin->body - 1, st->pktin->length + 1,
1074 &decompblk, &decomplen)) {
1075 bombout(("Zlib decompression encountered invalid data"));
1076 ssh_free_packet(st->pktin);
1080 if (st->pktin->maxlen < st->pad + decomplen) {
1081 st->pktin->maxlen = st->pad + decomplen;
1082 st->pktin->data = sresize(st->pktin->data,
1083 st->pktin->maxlen + APIEXTRA,
1085 st->pktin->body = st->pktin->data + st->pad + 1;
1088 memcpy(st->pktin->body - 1, decompblk, decomplen);
1090 st->pktin->length = decomplen - 1;
1093 st->pktin->type = st->pktin->body[-1];
1096 * Log incoming packet, possibly omitting sensitive fields.
1100 struct logblank_t blank;
1101 if (ssh->cfg.logomitdata) {
1102 int do_blank = FALSE, blank_prefix = 0;
1103 /* "Session data" packets - omit the data field */
1104 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1105 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
1106 do_blank = TRUE; blank_prefix = 0;
1107 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
1108 do_blank = TRUE; blank_prefix = 4;
1111 blank.offset = blank_prefix;
1112 blank.len = st->pktin->length;
1113 blank.type = PKTLOG_OMIT;
1117 log_packet(ssh->logctx,
1118 PKT_INCOMING, st->pktin->type,
1119 ssh1_pkt_type(st->pktin->type),
1120 st->pktin->body, st->pktin->length,
1124 crFinish(st->pktin);
1127 static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1129 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1131 crBegin(ssh->ssh2_rdpkt_crstate);
1133 st->pktin = ssh_new_packet();
1135 st->pktin->type = 0;
1136 st->pktin->length = 0;
1138 st->cipherblk = ssh->sccipher->blksize;
1141 if (st->cipherblk < 8)
1144 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1147 * Acquire and decrypt the first block of the packet. This will
1148 * contain the length and padding details.
1150 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1151 while ((*datalen) == 0)
1153 st->pktin->data[st->i] = *(*data)++;
1158 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1159 st->pktin->data, st->cipherblk);
1162 * Now get the length and padding figures.
1164 st->len = GET_32BIT(st->pktin->data);
1165 st->pad = st->pktin->data[4];
1168 * _Completely_ silly lengths should be stomped on before they
1169 * do us any more damage.
1171 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
1172 bombout(("Incoming packet was garbled on decryption"));
1173 ssh_free_packet(st->pktin);
1178 * This enables us to deduce the payload length.
1180 st->payload = st->len - st->pad - 1;
1182 st->pktin->length = st->payload + 5;
1185 * So now we can work out the total packet length.
1187 st->packetlen = st->len + 4;
1188 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1191 * Allocate memory for the rest of the packet.
1193 st->pktin->maxlen = st->packetlen + st->maclen;
1194 st->pktin->data = sresize(st->pktin->data,
1195 st->pktin->maxlen + APIEXTRA,
1199 * Read and decrypt the remainder of the packet.
1201 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1203 while ((*datalen) == 0)
1205 st->pktin->data[st->i] = *(*data)++;
1208 /* Decrypt everything _except_ the MAC. */
1210 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1211 st->pktin->data + st->cipherblk,
1212 st->packetlen - st->cipherblk);
1214 st->pktin->encrypted_len = st->packetlen;
1220 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, st->len + 4,
1221 st->incoming_sequence)) {
1222 bombout(("Incorrect MAC received on packet"));
1223 ssh_free_packet(st->pktin);
1227 st->pktin->sequence = st->incoming_sequence++;
1230 * Decompress packet payload.
1233 unsigned char *newpayload;
1236 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1237 st->pktin->data + 5, st->pktin->length - 5,
1238 &newpayload, &newlen)) {
1239 if (st->pktin->maxlen < newlen + 5) {
1240 st->pktin->maxlen = newlen + 5;
1241 st->pktin->data = sresize(st->pktin->data,
1242 st->pktin->maxlen + APIEXTRA,
1245 st->pktin->length = 5 + newlen;
1246 memcpy(st->pktin->data + 5, newpayload, newlen);
1251 st->pktin->savedpos = 6;
1252 st->pktin->body = st->pktin->data;
1253 st->pktin->type = st->pktin->data[5];
1256 * Log incoming packet, possibly omitting sensitive fields.
1260 struct logblank_t blank;
1261 if (ssh->cfg.logomitdata) {
1262 int do_blank = FALSE, blank_prefix = 0;
1263 /* "Session data" packets - omit the data field */
1264 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
1265 do_blank = TRUE; blank_prefix = 4;
1266 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1267 do_blank = TRUE; blank_prefix = 8;
1270 blank.offset = blank_prefix;
1271 blank.len = (st->pktin->length-6) - blank_prefix;
1272 blank.type = PKTLOG_OMIT;
1276 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1277 ssh2_pkt_type(ssh->pkt_ctx, st->pktin->type),
1278 st->pktin->data+6, st->pktin->length-6,
1282 crFinish(st->pktin);
1285 static void ssh1_pktout_size(struct Packet *pkt, int len)
1289 len += 5; /* type and CRC */
1290 pad = 8 - (len % 8);
1293 pkt->length = len - 5;
1294 if (pkt->maxlen < biglen) {
1295 pkt->maxlen = biglen;
1296 pkt->data = sresize(pkt->data, biglen + 4 + APIEXTRA, unsigned char);
1298 pkt->body = pkt->data + 4 + pad + 1;
1301 static struct Packet *s_wrpkt_start(int type, int len)
1303 struct Packet *pkt = ssh_new_packet();
1304 ssh1_pktout_size(pkt, len);
1306 /* Initialise log omission state */
1312 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt)
1318 * XXX various versions of SC (including 8.8.4) screw up the
1319 * register allocation in this function and use the same register
1320 * (D6) for len and as a temporary, with predictable results. The
1321 * following sledgehammer prevents this.
1327 pkt->body[-1] = pkt->type;
1330 log_packet(ssh->logctx, PKT_OUTGOING, pkt->type,
1331 ssh1_pkt_type(pkt->type),
1332 pkt->body, pkt->length,
1333 pkt->nblanks, pkt->blanks);
1334 sfree(pkt->blanks); pkt->blanks = NULL;
1337 if (ssh->v1_compressing) {
1338 unsigned char *compblk;
1340 zlib_compress_block(ssh->cs_comp_ctx,
1341 pkt->body - 1, pkt->length + 1,
1342 &compblk, &complen);
1343 ssh1_pktout_size(pkt, complen - 1);
1344 memcpy(pkt->body - 1, compblk, complen);
1348 len = pkt->length + 5; /* type and CRC */
1349 pad = 8 - (len % 8);
1352 for (i = 0; i < pad; i++)
1353 pkt->data[i + 4] = random_byte();
1354 crc = crc32_compute(pkt->data + 4, biglen - 4);
1355 PUT_32BIT(pkt->data + biglen, crc);
1356 PUT_32BIT(pkt->data, len);
1359 ssh->cipher->encrypt(ssh->v1_cipher_ctx, pkt->data + 4, biglen);
1364 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1367 len = s_wrpkt_prepare(ssh, pkt);
1368 backlog = sk_write(ssh->s, (char *)pkt->data, len);
1369 if (backlog > SSH_MAX_BACKLOG)
1370 ssh_throttle_all(ssh, 1, backlog);
1373 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1376 len = s_wrpkt_prepare(ssh, pkt);
1377 if (ssh->deferred_len + len > ssh->deferred_size) {
1378 ssh->deferred_size = ssh->deferred_len + len + 128;
1379 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1383 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
1384 ssh->deferred_len += len;
1388 * Construct a packet with the specified contents.
1390 static struct Packet *construct_packet(Ssh ssh, int pkttype,
1391 va_list ap1, va_list ap2)
1393 unsigned char *p, *argp, argchar;
1394 unsigned long argint;
1395 int pktlen, argtype, arglen;
1400 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1403 (void) va_arg(ap1, int);
1407 (void) va_arg(ap1, int);
1411 (void) va_arg(ap1, unsigned char *);
1412 arglen = va_arg(ap1, int);
1416 argp = va_arg(ap1, unsigned char *);
1417 arglen = strlen((char *)argp);
1418 pktlen += 4 + arglen;
1421 bn = va_arg(ap1, Bignum);
1422 pktlen += ssh1_bignum_length(bn);
1427 /* ignore this pass */
1434 pkt = s_wrpkt_start(pkttype, pktlen);
1437 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1438 int offset = p - pkt->body, len = 0;
1440 /* Actual fields in the packet */
1442 argint = va_arg(ap2, int);
1443 PUT_32BIT(p, argint);
1447 argchar = (unsigned char) va_arg(ap2, int);
1452 argp = va_arg(ap2, unsigned char *);
1453 arglen = va_arg(ap2, int);
1454 memcpy(p, argp, arglen);
1458 argp = va_arg(ap2, unsigned char *);
1459 arglen = strlen((char *)argp);
1460 PUT_32BIT(p, arglen);
1461 memcpy(p + 4, argp, arglen);
1465 bn = va_arg(ap2, Bignum);
1466 len = ssh1_write_bignum(p, bn);
1468 /* Tokens for modifications to packet logging */
1470 dont_log_password(ssh, pkt, PKTLOG_BLANK);
1473 dont_log_data(ssh, pkt, PKTLOG_OMIT);
1476 end_log_omission(ssh, pkt);
1480 /* Deal with logfile omission, if required. */
1481 if (len && (pkt->logmode != PKTLOG_EMIT)) {
1483 pkt->blanks = sresize(pkt->blanks, pkt->nblanks,
1485 pkt->blanks[pkt->nblanks-1].offset = offset;
1486 pkt->blanks[pkt->nblanks-1].len = len;
1487 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1494 static void send_packet(Ssh ssh, int pkttype, ...)
1498 va_start(ap1, pkttype);
1499 va_start(ap2, pkttype);
1500 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1504 ssh_free_packet(pkt);
1507 static void defer_packet(Ssh ssh, int pkttype, ...)
1511 va_start(ap1, pkttype);
1512 va_start(ap2, pkttype);
1513 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1516 s_wrpkt_defer(ssh, pkt);
1517 ssh_free_packet(pkt);
1520 static int ssh_versioncmp(char *a, char *b)
1523 unsigned long av, bv;
1525 av = strtoul(a, &ae, 10);
1526 bv = strtoul(b, &be, 10);
1528 return (av < bv ? -1 : +1);
1533 av = strtoul(ae, &ae, 10);
1534 bv = strtoul(be, &be, 10);
1536 return (av < bv ? -1 : +1);
1541 * Utility routines for putting an SSH-protocol `string' and
1542 * `uint32' into a SHA state.
1545 static void sha_string(SHA_State * s, void *str, int len)
1547 unsigned char lenblk[4];
1548 PUT_32BIT(lenblk, len);
1549 SHA_Bytes(s, lenblk, 4);
1550 SHA_Bytes(s, str, len);
1553 static void sha_uint32(SHA_State * s, unsigned i)
1555 unsigned char intblk[4];
1556 PUT_32BIT(intblk, i);
1557 SHA_Bytes(s, intblk, 4);
1561 * SSH2 packet construction functions.
1563 static void ssh2_pkt_ensure(struct Packet *pkt, int length)
1565 if (pkt->maxlen < length) {
1566 pkt->maxlen = length + 256;
1567 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
1570 static void ssh2_pkt_adddata(struct Packet *pkt, void *data, int len)
1572 if (pkt->logmode != PKTLOG_EMIT) {
1574 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1575 pkt->blanks[pkt->nblanks-1].offset = pkt->length - 6;
1576 pkt->blanks[pkt->nblanks-1].len = len;
1577 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1580 ssh2_pkt_ensure(pkt, pkt->length);
1581 memcpy(pkt->data + pkt->length - len, data, len);
1583 static void ssh2_pkt_addbyte(struct Packet *pkt, unsigned char byte)
1585 ssh2_pkt_adddata(pkt, &byte, 1);
1587 static struct Packet *ssh2_pkt_init(int pkt_type)
1589 struct Packet *pkt = ssh_new_packet();
1592 ssh2_pkt_addbyte(pkt, (unsigned char) pkt_type);
1595 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
1597 ssh2_pkt_adddata(pkt, &value, 1);
1599 static void ssh2_pkt_adduint32(struct Packet *pkt, unsigned long value)
1602 PUT_32BIT(x, value);
1603 ssh2_pkt_adddata(pkt, x, 4);
1605 static void ssh2_pkt_addstring_start(struct Packet *pkt)
1607 ssh2_pkt_adduint32(pkt, 0);
1608 pkt->savedpos = pkt->length;
1610 static void ssh2_pkt_addstring_str(struct Packet *pkt, char *data)
1612 ssh2_pkt_adddata(pkt, data, strlen(data));
1613 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1615 static void ssh2_pkt_addstring_data(struct Packet *pkt, char *data, int len)
1617 ssh2_pkt_adddata(pkt, data, len);
1618 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1620 static void ssh2_pkt_addstring(struct Packet *pkt, char *data)
1622 ssh2_pkt_addstring_start(pkt);
1623 ssh2_pkt_addstring_str(pkt, data);
1625 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1628 int i, n = (bignum_bitcount(b) + 7) / 8;
1629 p = snewn(n + 1, unsigned char);
1631 fatalbox("out of memory");
1633 for (i = 1; i <= n; i++)
1634 p[i] = bignum_byte(b, n - i);
1636 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1638 memmove(p, p + i, n + 1 - i);
1642 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
1646 p = ssh2_mpint_fmt(b, &len);
1647 ssh2_pkt_addstring_start(pkt);
1648 ssh2_pkt_addstring_data(pkt, (char *)p, len);
1653 * Construct an SSH2 final-form packet: compress it, encrypt it,
1654 * put the MAC on it. Final packet, ready to be sent, is stored in
1655 * pkt->data. Total length is returned.
1657 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
1659 int cipherblk, maclen, padding, i;
1662 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1663 ssh2_pkt_type(ssh->pkt_ctx, pkt->data[5]),
1664 pkt->data + 6, pkt->length - 6,
1665 pkt->nblanks, pkt->blanks);
1666 sfree(pkt->blanks); pkt->blanks = NULL;
1670 * Compress packet payload.
1673 unsigned char *newpayload;
1676 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1678 &newpayload, &newlen)) {
1680 ssh2_pkt_adddata(pkt, newpayload, newlen);
1686 * Add padding. At least four bytes, and must also bring total
1687 * length (minus MAC) up to a multiple of the block size.
1688 * If pkt->forcepad is set, make sure the packet is at least that size
1691 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1692 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1694 if (pkt->length + padding < pkt->forcepad)
1695 padding = pkt->forcepad - pkt->length;
1697 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
1698 assert(padding <= 255);
1699 maclen = ssh->csmac ? ssh->csmac->len : 0;
1700 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1701 pkt->data[4] = padding;
1702 for (i = 0; i < padding; i++)
1703 pkt->data[pkt->length + i] = random_byte();
1704 PUT_32BIT(pkt->data, pkt->length + padding - 4);
1706 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1707 pkt->length + padding,
1708 ssh->v2_outgoing_sequence);
1709 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1712 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1713 pkt->data, pkt->length + padding);
1715 pkt->encrypted_len = pkt->length + padding;
1717 /* Ready-to-send packet starts at pkt->data. We return length. */
1718 return pkt->length + padding + maclen;
1722 * Routines called from the main SSH code to send packets. There
1723 * are quite a few of these, because we have two separate
1724 * mechanisms for delaying the sending of packets:
1726 * - In order to send an IGNORE message and a password message in
1727 * a single fixed-length blob, we require the ability to
1728 * concatenate the encrypted forms of those two packets _into_ a
1729 * single blob and then pass it to our <network.h> transport
1730 * layer in one go. Hence, there's a deferment mechanism which
1731 * works after packet encryption.
1733 * - In order to avoid sending any connection-layer messages
1734 * during repeat key exchange, we have to queue up any such
1735 * outgoing messages _before_ they are encrypted (and in
1736 * particular before they're allocated sequence numbers), and
1737 * then send them once we've finished.
1739 * I call these mechanisms `defer' and `queue' respectively, so as
1740 * to distinguish them reasonably easily.
1742 * The functions send_noqueue() and defer_noqueue() free the packet
1743 * structure they are passed. Every outgoing packet goes through
1744 * precisely one of these functions in its life; packets passed to
1745 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
1746 * these or get queued, and then when the queue is later emptied
1747 * the packets are all passed to defer_noqueue().
1751 * Send an SSH2 packet immediately, without queuing or deferring.
1753 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
1757 len = ssh2_pkt_construct(ssh, pkt);
1758 backlog = sk_write(ssh->s, (char *)pkt->data, len);
1759 if (backlog > SSH_MAX_BACKLOG)
1760 ssh_throttle_all(ssh, 1, backlog);
1762 ssh->outgoing_data_size += pkt->encrypted_len;
1763 if (!ssh->kex_in_progress &&
1764 ssh->max_data_size != 0 &&
1765 ssh->outgoing_data_size > ssh->max_data_size)
1766 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
1768 ssh_free_packet(pkt);
1772 * Defer an SSH2 packet.
1774 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt)
1776 int len = ssh2_pkt_construct(ssh, pkt);
1777 if (ssh->deferred_len + len > ssh->deferred_size) {
1778 ssh->deferred_size = ssh->deferred_len + len + 128;
1779 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1783 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
1784 ssh->deferred_len += len;
1785 ssh->deferred_data_size += pkt->encrypted_len;
1786 ssh_free_packet(pkt);
1790 * Queue an SSH2 packet.
1792 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
1794 assert(ssh->queueing);
1796 if (ssh->queuelen >= ssh->queuesize) {
1797 ssh->queuesize = ssh->queuelen + 32;
1798 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
1801 ssh->queue[ssh->queuelen++] = pkt;
1805 * Either queue or send a packet, depending on whether queueing is
1808 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
1811 ssh2_pkt_queue(ssh, pkt);
1813 ssh2_pkt_send_noqueue(ssh, pkt);
1818 * Either queue or defer a packet, depending on whether queueing is
1821 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
1824 ssh2_pkt_queue(ssh, pkt);
1826 ssh2_pkt_defer_noqueue(ssh, pkt);
1831 * Send the whole deferred data block constructed by
1832 * ssh2_pkt_defer() or SSH1's defer_packet().
1834 * The expected use of the defer mechanism is that you call
1835 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
1836 * not currently queueing, this simply sets up deferred_send_data
1837 * and then sends it. If we _are_ currently queueing, the calls to
1838 * ssh2_pkt_defer() put the deferred packets on to the queue
1839 * instead, and therefore ssh_pkt_defersend() has no deferred data
1840 * to send. Hence, there's no need to make it conditional on
1843 static void ssh_pkt_defersend(Ssh ssh)
1846 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1848 ssh->deferred_len = ssh->deferred_size = 0;
1849 sfree(ssh->deferred_send_data);
1850 ssh->deferred_send_data = NULL;
1851 if (backlog > SSH_MAX_BACKLOG)
1852 ssh_throttle_all(ssh, 1, backlog);
1854 ssh->outgoing_data_size += ssh->deferred_data_size;
1855 if (!ssh->kex_in_progress &&
1856 ssh->max_data_size != 0 &&
1857 ssh->outgoing_data_size > ssh->max_data_size)
1858 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
1859 ssh->deferred_data_size = 0;
1863 * Send all queued SSH2 packets. We send them by means of
1864 * ssh2_pkt_defer_noqueue(), in case they included a pair of
1865 * packets that needed to be lumped together.
1867 static void ssh2_pkt_queuesend(Ssh ssh)
1871 assert(!ssh->queueing);
1873 for (i = 0; i < ssh->queuelen; i++)
1874 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i]);
1877 ssh_pkt_defersend(ssh);
1881 void bndebug(char *string, Bignum b)
1885 p = ssh2_mpint_fmt(b, &len);
1886 debug(("%s", string));
1887 for (i = 0; i < len; i++)
1888 debug((" %02x", p[i]));
1894 static void sha_mpint(SHA_State * s, Bignum b)
1898 p = ssh2_mpint_fmt(b, &len);
1899 sha_string(s, p, len);
1904 * Packet decode functions for both SSH1 and SSH2.
1906 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
1908 unsigned long value;
1909 if (pkt->length - pkt->savedpos < 4)
1910 return 0; /* arrgh, no way to decline (FIXME?) */
1911 value = GET_32BIT(pkt->body + pkt->savedpos);
1915 static int ssh2_pkt_getbool(struct Packet *pkt)
1917 unsigned long value;
1918 if (pkt->length - pkt->savedpos < 1)
1919 return 0; /* arrgh, no way to decline (FIXME?) */
1920 value = pkt->body[pkt->savedpos] != 0;
1924 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
1929 if (pkt->length - pkt->savedpos < 4)
1931 len = GET_32BIT(pkt->body + pkt->savedpos);
1936 if (pkt->length - pkt->savedpos < *length)
1938 *p = (char *)(pkt->body + pkt->savedpos);
1939 pkt->savedpos += *length;
1941 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
1943 if (pkt->length - pkt->savedpos < length)
1945 pkt->savedpos += length;
1946 return pkt->body + (pkt->savedpos - length);
1948 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
1949 unsigned char **keystr)
1953 j = makekey(pkt->body + pkt->savedpos,
1954 pkt->length - pkt->savedpos,
1961 assert(pkt->savedpos < pkt->length);
1965 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
1970 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
1971 pkt->length - pkt->savedpos, &b);
1979 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
1985 ssh_pkt_getstring(pkt, &p, &length);
1990 b = bignum_from_bytes((unsigned char *)p, length);
1995 * Helper function to add an SSH2 signature blob to a packet.
1996 * Expects to be shown the public key blob as well as the signature
1997 * blob. Normally works just like ssh2_pkt_addstring, but will
1998 * fiddle with the signature packet if necessary for
1999 * BUG_SSH2_RSA_PADDING.
2001 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2002 void *pkblob_v, int pkblob_len,
2003 void *sigblob_v, int sigblob_len)
2005 unsigned char *pkblob = (unsigned char *)pkblob_v;
2006 unsigned char *sigblob = (unsigned char *)sigblob_v;
2008 /* dmemdump(pkblob, pkblob_len); */
2009 /* dmemdump(sigblob, sigblob_len); */
2012 * See if this is in fact an ssh-rsa signature and a buggy
2013 * server; otherwise we can just do this the easy way.
2015 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
2016 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2017 int pos, len, siglen;
2020 * Find the byte length of the modulus.
2023 pos = 4+7; /* skip over "ssh-rsa" */
2024 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
2025 len = GET_32BIT(pkblob+pos); /* find length of modulus */
2026 pos += 4; /* find modulus itself */
2027 while (len > 0 && pkblob[pos] == 0)
2029 /* debug(("modulus length is %d\n", len)); */
2032 * Now find the signature integer.
2034 pos = 4+7; /* skip over "ssh-rsa" */
2035 siglen = GET_32BIT(sigblob+pos);
2036 /* debug(("signature length is %d\n", siglen)); */
2038 if (len != siglen) {
2039 unsigned char newlen[4];
2040 ssh2_pkt_addstring_start(pkt);
2041 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2042 /* dmemdump(sigblob, pos); */
2043 pos += 4; /* point to start of actual sig */
2044 PUT_32BIT(newlen, len);
2045 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2046 /* dmemdump(newlen, 4); */
2048 while (len-- > siglen) {
2049 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2050 /* dmemdump(newlen, 1); */
2052 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2053 /* dmemdump(sigblob+pos, siglen); */
2057 /* Otherwise fall through and do it the easy way. */
2060 ssh2_pkt_addstring_start(pkt);
2061 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2065 * Examine the remote side's version string and compare it against
2066 * a list of known buggy implementations.
2068 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2070 char *imp; /* pointer to implementation part */
2072 imp += strcspn(imp, "-");
2074 imp += strcspn(imp, "-");
2077 ssh->remote_bugs = 0;
2079 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
2080 (ssh->cfg.sshbug_ignore1 == AUTO &&
2081 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2082 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2083 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2084 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2086 * These versions don't support SSH1_MSG_IGNORE, so we have
2087 * to use a different defence against password length
2090 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2091 logevent("We believe remote version has SSH1 ignore bug");
2094 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
2095 (ssh->cfg.sshbug_plainpw1 == AUTO &&
2096 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2098 * These versions need a plain password sent; they can't
2099 * handle having a null and a random length of data after
2102 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2103 logevent("We believe remote version needs a plain SSH1 password");
2106 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
2107 (ssh->cfg.sshbug_rsa1 == AUTO &&
2108 (!strcmp(imp, "Cisco-1.25")))) {
2110 * These versions apparently have no clue whatever about
2111 * RSA authentication and will panic and die if they see
2112 * an AUTH_RSA message.
2114 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2115 logevent("We believe remote version can't handle RSA authentication");
2118 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2119 (ssh->cfg.sshbug_hmac2 == AUTO &&
2120 !wc_match("* VShell", imp) &&
2121 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2122 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2123 wc_match("2.1 *", imp)))) {
2125 * These versions have the HMAC bug.
2127 ssh->remote_bugs |= BUG_SSH2_HMAC;
2128 logevent("We believe remote version has SSH2 HMAC bug");
2131 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2132 (ssh->cfg.sshbug_derivekey2 == AUTO &&
2133 !wc_match("* VShell", imp) &&
2134 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2136 * These versions have the key-derivation bug (failing to
2137 * include the literal shared secret in the hashes that
2138 * generate the keys).
2140 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2141 logevent("We believe remote version has SSH2 key-derivation bug");
2144 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2145 (ssh->cfg.sshbug_rsapad2 == AUTO &&
2146 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2147 wc_match("OpenSSH_3.[0-2]*", imp)))) {
2149 * These versions have the SSH2 RSA padding bug.
2151 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2152 logevent("We believe remote version has SSH2 RSA padding bug");
2155 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2156 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2157 wc_match("OpenSSH_2.[0-2]*", imp))) {
2159 * These versions have the SSH2 session-ID bug in
2160 * public-key authentication.
2162 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2163 logevent("We believe remote version has SSH2 public-key-session-ID bug");
2166 if (ssh->cfg.sshbug_rekey2 == FORCE_ON ||
2167 (ssh->cfg.sshbug_rekey2 == AUTO &&
2168 (wc_match("OpenSSH_2.[0-4]*", imp) ||
2169 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2170 wc_match("Sun_SSH_1.0", imp) ||
2171 wc_match("Sun_SSH_1.0.1", imp)))) {
2173 * These versions have the SSH2 rekey bug.
2175 ssh->remote_bugs |= BUG_SSH2_REKEY;
2176 logevent("We believe remote version has SSH2 rekey bug");
2181 * The `software version' part of an SSH version string is required
2182 * to contain no spaces or minus signs.
2184 static void ssh_fix_verstring(char *str)
2186 /* Eat "SSH-<protoversion>-". */
2187 assert(*str == 'S'); str++;
2188 assert(*str == 'S'); str++;
2189 assert(*str == 'H'); str++;
2190 assert(*str == '-'); str++;
2191 while (*str && *str != '-') str++;
2192 assert(*str == '-'); str++;
2194 /* Convert minus signs and spaces in the remaining string into
2197 if (*str == '-' || *str == ' ')
2203 static int do_ssh_init(Ssh ssh, unsigned char c)
2205 struct do_ssh_init_state {
2213 crState(do_ssh_init_state);
2215 crBegin(ssh->do_ssh_init_crstate);
2217 /* Search for the string "SSH-" in the input. */
2220 static const int transS[] = { 1, 2, 2, 1 };
2221 static const int transH[] = { 0, 0, 3, 0 };
2222 static const int transminus[] = { 0, 0, 0, -1 };
2224 s->i = transS[s->i];
2226 s->i = transH[s->i];
2228 s->i = transminus[s->i];
2233 crReturn(1); /* get another character */
2237 s->vstring = snewn(s->vstrsize, char);
2238 strcpy(s->vstring, "SSH-");
2242 crReturn(1); /* get another char */
2243 if (s->vslen >= s->vstrsize - 1) {
2245 s->vstring = sresize(s->vstring, s->vstrsize, char);
2247 s->vstring[s->vslen++] = c;
2250 s->version[s->i] = '\0';
2252 } else if (s->i < sizeof(s->version) - 1)
2253 s->version[s->i++] = c;
2254 } else if (c == '\012')
2258 ssh->agentfwd_enabled = FALSE;
2259 ssh->rdpkt2_state.incoming_sequence = 0;
2261 s->vstring[s->vslen] = 0;
2262 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2263 logeventf(ssh, "Server version: %s", s->vstring);
2264 ssh_detect_bugs(ssh, s->vstring);
2267 * Decide which SSH protocol version to support.
2270 /* Anything strictly below "2.0" means protocol 1 is supported. */
2271 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2272 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2273 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2275 if (ssh->cfg.sshprot == 0 && !s->proto1) {
2276 bombout(("SSH protocol version 1 required by user but not provided by server"));
2279 if (ssh->cfg.sshprot == 3 && !s->proto2) {
2280 bombout(("SSH protocol version 2 required by user but not provided by server"));
2287 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2289 * Construct a v2 version string.
2291 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2295 * Construct a v1 version string.
2297 verstring = dupprintf("SSH-%s-%s\012",
2298 (ssh_versioncmp(s->version, "1.5") <= 0 ?
2299 s->version : "1.5"),
2304 ssh_fix_verstring(verstring);
2306 if (ssh->version == 2) {
2308 * Hash our version string and their version string.
2310 SHA_Init(&ssh->exhashbase);
2311 sha_string(&ssh->exhashbase, verstring,
2312 strcspn(verstring, "\015\012"));
2313 sha_string(&ssh->exhashbase, s->vstring,
2314 strcspn(s->vstring, "\015\012"));
2317 * Initialise SSHv2 protocol.
2319 ssh->protocol = ssh2_protocol;
2320 ssh2_protocol_setup(ssh);
2321 ssh->s_rdpkt = ssh2_rdpkt;
2324 * Initialise SSHv1 protocol.
2326 ssh->protocol = ssh1_protocol;
2327 ssh1_protocol_setup(ssh);
2328 ssh->s_rdpkt = ssh1_rdpkt;
2330 logeventf(ssh, "We claim version: %.*s",
2331 strcspn(verstring, "\015\012"), verstring);
2332 sk_write(ssh->s, verstring, strlen(verstring));
2336 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2338 update_specials_menu(ssh->frontend);
2339 ssh->state = SSH_STATE_BEFORE_SIZE;
2340 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
2347 static void ssh_process_incoming_data(Ssh ssh,
2348 unsigned char **data, int *datalen)
2350 struct Packet *pktin = ssh->s_rdpkt(ssh, data, datalen);
2352 ssh->protocol(ssh, NULL, 0, pktin);
2353 ssh_free_packet(pktin);
2357 static void ssh_queue_incoming_data(Ssh ssh,
2358 unsigned char **data, int *datalen)
2360 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
2365 static void ssh_process_queued_incoming_data(Ssh ssh)
2368 unsigned char *data;
2371 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
2372 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
2376 while (!ssh->frozen && len > 0)
2377 ssh_process_incoming_data(ssh, &data, &len);
2380 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
2384 static void ssh_set_frozen(Ssh ssh, int frozen)
2387 sk_set_frozen(ssh->s, frozen);
2388 ssh->frozen = frozen;
2391 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2393 crBegin(ssh->ssh_gotdata_crstate);
2396 * To begin with, feed the characters one by one to the
2397 * protocol initialisation / selection function do_ssh_init().
2398 * When that returns 0, we're done with the initial greeting
2399 * exchange and can move on to packet discipline.
2402 int ret; /* need not be kept across crReturn */
2404 crReturnV; /* more data please */
2405 ret = do_ssh_init(ssh, *data);
2413 * We emerge from that loop when the initial negotiation is
2414 * over and we have selected an s_rdpkt function. Now pass
2415 * everything to s_rdpkt, and then pass the resulting packets
2416 * to the proper protocol handler.
2422 * Process queued data if there is any.
2424 ssh_process_queued_incoming_data(ssh);
2427 while (datalen > 0) {
2429 ssh_queue_incoming_data(ssh, &data, &datalen);
2431 ssh_process_incoming_data(ssh, &data, &datalen);
2433 if (ssh->state == SSH_STATE_CLOSED)
2441 static int ssh_do_close(Ssh ssh, int notify_exit)
2444 struct ssh_channel *c;
2446 ssh->state = SSH_STATE_CLOSED;
2451 notify_remote_exit(ssh->frontend);
2456 * Now we must shut down any port- and X-forwarded channels going
2457 * through this connection.
2459 if (ssh->channels) {
2460 while (NULL != (c = index234(ssh->channels, 0))) {
2463 x11_close(c->u.x11.s);
2466 pfd_close(c->u.pfd.s);
2469 del234(ssh->channels, c); /* moving next one to index 0 */
2470 if (ssh->version == 2)
2471 bufchain_clear(&c->v.v2.outbuffer);
2476 * Go through port-forwardings, and close any associated
2477 * listening sockets.
2479 if (ssh->portfwds) {
2480 struct ssh_portfwd *pf;
2481 while (NULL != (pf = index234(ssh->portfwds, 0))) {
2482 /* Dispose of any listening socket. */
2484 pfd_terminate(pf->local);
2485 del234(ssh->portfwds, pf); /* moving next one to index 0 */
2493 static void ssh_log(Plug plug, int type, SockAddr addr, int port,
2494 const char *error_msg, int error_code)
2496 Ssh ssh = (Ssh) plug;
2497 char addrbuf[256], *msg;
2499 sk_getaddr(addr, addrbuf, lenof(addrbuf));
2502 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
2504 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
2510 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2513 Ssh ssh = (Ssh) plug;
2514 int need_notify = ssh_do_close(ssh, FALSE);
2516 if (!error_msg && !ssh->close_expected) {
2517 error_msg = "Server unexpectedly closed network connection";
2521 /* A socket error has occurred. */
2522 logevent(error_msg);
2523 connection_fatal(ssh->frontend, "%s", error_msg);
2525 logevent("Server closed network connection");
2528 notify_remote_exit(ssh->frontend);
2532 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2534 Ssh ssh = (Ssh) plug;
2535 ssh_gotdata(ssh, (unsigned char *)data, len);
2536 if (ssh->state == SSH_STATE_CLOSED) {
2537 ssh_do_close(ssh, TRUE);
2543 static void ssh_sent(Plug plug, int bufsize)
2545 Ssh ssh = (Ssh) plug;
2547 * If the send backlog on the SSH socket itself clears, we
2548 * should unthrottle the whole world if it was throttled.
2550 if (bufsize < SSH_MAX_BACKLOG)
2551 ssh_throttle_all(ssh, 0, bufsize);
2555 * Connect to specified host and port.
2556 * Returns an error message, or NULL on success.
2557 * Also places the canonical host name into `realhost'. It must be
2558 * freed by the caller.
2560 static const char *connect_to_host(Ssh ssh, char *host, int port,
2561 char **realhost, int nodelay, int keepalive)
2563 static const struct plug_function_table fn_table = {
2574 ssh->savedhost = snewn(1 + strlen(host), char);
2575 if (!ssh->savedhost)
2576 fatalbox("Out of memory");
2577 strcpy(ssh->savedhost, host);
2580 port = 22; /* default ssh port */
2581 ssh->savedport = port;
2586 logeventf(ssh, "Looking up host \"%s\"%s", host,
2587 (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
2588 (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
2589 addr = name_lookup(host, port, realhost, &ssh->cfg,
2590 ssh->cfg.addressfamily);
2591 if ((err = sk_addr_error(addr)) != NULL) {
2599 ssh->fn = &fn_table;
2600 ssh->s = new_connection(addr, *realhost, port,
2601 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
2602 if ((err = sk_socket_error(ssh->s)) != NULL) {
2604 notify_remote_exit(ssh->frontend);
2612 * Throttle or unthrottle the SSH connection.
2614 static void ssh1_throttle(Ssh ssh, int adjust)
2616 int old_count = ssh->v1_throttle_count;
2617 ssh->v1_throttle_count += adjust;
2618 assert(ssh->v1_throttle_count >= 0);
2619 if (ssh->v1_throttle_count && !old_count) {
2620 ssh_set_frozen(ssh, 1);
2621 } else if (!ssh->v1_throttle_count && old_count) {
2622 ssh_set_frozen(ssh, 0);
2627 * Throttle or unthrottle _all_ local data streams (for when sends
2628 * on the SSH connection itself back up).
2630 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2633 struct ssh_channel *c;
2635 if (enable == ssh->throttled_all)
2637 ssh->throttled_all = enable;
2638 ssh->overall_bufsize = bufsize;
2641 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2643 case CHAN_MAINSESSION:
2645 * This is treated separately, outside the switch.
2649 x11_override_throttle(c->u.x11.s, enable);
2652 /* Agent channels require no buffer management. */
2655 pfd_override_throttle(c->u.pfd.s, enable);
2662 * Username and password input, abstracted off into routines
2663 * reusable in several places - even between SSH1 and SSH2.
2666 /* Set up a username or password input loop on a given buffer. */
2667 static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2669 ssh->userpass_input_buffer = buffer;
2670 ssh->userpass_input_buflen = buflen;
2671 ssh->userpass_input_bufpos = 0;
2672 ssh->userpass_input_echo = echo;
2676 * Process some terminal data in the course of username/password
2677 * input. Returns >0 for success (line of input returned in
2678 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2679 * for inconclusive (keep waiting for more input please).
2681 static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2686 switch (c = *in++) {
2689 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2690 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2695 if (ssh->userpass_input_bufpos > 0) {
2696 if (ssh->userpass_input_echo)
2697 c_write_str(ssh, "\b \b");
2698 ssh->userpass_input_bufpos--;
2703 while (ssh->userpass_input_bufpos > 0) {
2704 if (ssh->userpass_input_echo)
2705 c_write_str(ssh, "\b \b");
2706 ssh->userpass_input_bufpos--;
2715 * This simplistic check for printability is disabled
2716 * when we're doing password input, because some people
2717 * have control characters in their passwords.o
2719 if ((!ssh->userpass_input_echo ||
2720 (c >= ' ' && c <= '~') ||
2721 ((unsigned char) c >= 160))
2722 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2723 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2724 if (ssh->userpass_input_echo)
2725 c_write(ssh, &c, 1);
2733 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
2735 Ssh ssh = (Ssh) sshv;
2737 ssh->agent_response = reply;
2738 ssh->agent_response_len = replylen;
2740 if (ssh->version == 1)
2741 do_ssh1_login(ssh, NULL, -1, NULL);
2743 do_ssh2_authconn(ssh, NULL, -1, NULL);
2746 static void ssh_dialog_callback(void *sshv, int ret)
2748 Ssh ssh = (Ssh) sshv;
2750 ssh->user_response = ret;
2752 if (ssh->version == 1)
2753 do_ssh1_login(ssh, NULL, -1, NULL);
2755 do_ssh2_transport(ssh, NULL, -1, NULL);
2758 * This may have unfrozen the SSH connection, so do a
2761 ssh_process_queued_incoming_data(ssh);
2764 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
2766 struct ssh_channel *c = (struct ssh_channel *)cv;
2768 void *sentreply = reply;
2771 /* Fake SSH_AGENT_FAILURE. */
2772 sentreply = "\0\0\0\1\5";
2775 if (ssh->version == 2) {
2776 ssh2_add_channel_data(c, sentreply, replylen);
2779 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2780 PKT_INT, c->remoteid,
2783 PKT_DATA, sentreply, replylen,
2792 * Handle the key exchange and user authentication phases.
2794 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2795 struct Packet *pktin)
2798 unsigned char cookie[8], *ptr;
2799 struct RSAKey servkey, hostkey;
2800 struct MD5Context md5c;
2801 struct do_ssh1_login_state {
2803 unsigned char *rsabuf, *keystr1, *keystr2;
2804 unsigned long supported_ciphers_mask, supported_auths_mask;
2805 int tried_publickey, tried_agent;
2806 int tis_auth_refused, ccard_auth_refused;
2807 unsigned char session_id[16];
2810 void *publickey_blob;
2811 int publickey_bloblen;
2817 unsigned char request[5], *response, *p;
2827 crState(do_ssh1_login_state);
2829 crBegin(ssh->do_ssh1_login_crstate);
2834 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
2835 bombout(("Public key packet not received"));
2839 logevent("Received public keys");
2841 ptr = ssh_pkt_getdata(pktin, 8);
2843 bombout(("SSH1 public key packet stopped before random cookie"));
2846 memcpy(cookie, ptr, 8);
2848 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2849 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
2850 bombout(("Failed to read SSH1 public keys from public key packet"));
2855 * Log the host key fingerprint.
2859 logevent("Host key fingerprint is:");
2860 strcpy(logmsg, " ");
2861 hostkey.comment = NULL;
2862 rsa_fingerprint(logmsg + strlen(logmsg),
2863 sizeof(logmsg) - strlen(logmsg), &hostkey);
2867 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2868 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2869 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
2871 ssh->v1_local_protoflags =
2872 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2873 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2876 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2877 MD5Update(&md5c, s->keystr1, servkey.bytes);
2878 MD5Update(&md5c, cookie, 8);
2879 MD5Final(s->session_id, &md5c);
2881 for (i = 0; i < 32; i++)
2882 ssh->session_key[i] = random_byte();
2885 * Verify that the `bits' and `bytes' parameters match.
2887 if (hostkey.bits > hostkey.bytes * 8 ||
2888 servkey.bits > servkey.bytes * 8) {
2889 bombout(("SSH1 public keys were badly formatted"));
2893 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2895 s->rsabuf = snewn(s->len, unsigned char);
2897 fatalbox("Out of memory");
2900 * Verify the host key.
2904 * First format the key into a string.
2906 int len = rsastr_len(&hostkey);
2907 char fingerprint[100];
2908 char *keystr = snewn(len, char);
2910 fatalbox("Out of memory");
2911 rsastr_fmt(keystr, &hostkey);
2912 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2914 ssh_set_frozen(ssh, 1);
2915 s->dlgret = verify_ssh_host_key(ssh->frontend,
2916 ssh->savedhost, ssh->savedport,
2917 "rsa", keystr, fingerprint,
2918 ssh_dialog_callback, ssh);
2920 if (s->dlgret < 0) {
2924 bombout(("Unexpected data from server while waiting"
2925 " for user host key response"));
2928 } while (pktin || inlen > 0);
2929 s->dlgret = ssh->user_response;
2931 ssh_set_frozen(ssh, 0);
2933 if (s->dlgret == 0) {
2934 ssh->close_expected = TRUE;
2935 ssh_closing((Plug)ssh, NULL, 0, 0);
2939 for (i = 0; i < 32; i++) {
2940 s->rsabuf[i] = ssh->session_key[i];
2942 s->rsabuf[i] ^= s->session_id[i];
2945 if (hostkey.bytes > servkey.bytes) {
2946 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2948 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2950 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
2952 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2955 bombout(("SSH1 public key encryptions failed due to bad formatting"));
2959 logevent("Encrypted session key");
2962 int cipher_chosen = 0, warn = 0;
2963 char *cipher_string = NULL;
2965 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2966 int next_cipher = ssh->cfg.ssh_cipherlist[i];
2967 if (next_cipher == CIPHER_WARN) {
2968 /* If/when we choose a cipher, warn about it */
2970 } else if (next_cipher == CIPHER_AES) {
2971 /* XXX Probably don't need to mention this. */
2972 logevent("AES not supported in SSH1, skipping");
2974 switch (next_cipher) {
2975 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
2976 cipher_string = "3DES"; break;
2977 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
2978 cipher_string = "Blowfish"; break;
2979 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
2980 cipher_string = "single-DES"; break;
2982 if (s->supported_ciphers_mask & (1 << s->cipher_type))
2986 if (!cipher_chosen) {
2987 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2988 bombout(("Server violates SSH 1 protocol by not "
2989 "supporting 3DES encryption"));
2991 /* shouldn't happen */
2992 bombout(("No supported ciphers found"));
2996 /* Warn about chosen cipher if necessary. */
2998 ssh_set_frozen(ssh, 1);
2999 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3000 ssh_dialog_callback, ssh);
3001 if (s->dlgret < 0) {
3005 bombout(("Unexpected data from server while waiting"
3006 " for user response"));
3009 } while (pktin || inlen > 0);
3010 s->dlgret = ssh->user_response;
3012 ssh_set_frozen(ssh, 0);
3013 if (s->dlgret == 0) {
3014 ssh->close_expected = TRUE;
3015 ssh_closing((Plug)ssh, NULL, 0, 0);
3020 switch (s->cipher_type) {
3021 case SSH_CIPHER_3DES:
3022 logevent("Using 3DES encryption");
3024 case SSH_CIPHER_DES:
3025 logevent("Using single-DES encryption");
3027 case SSH_CIPHER_BLOWFISH:
3028 logevent("Using Blowfish encryption");
3032 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3033 PKT_CHAR, s->cipher_type,
3034 PKT_DATA, cookie, 8,
3035 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3036 PKT_DATA, s->rsabuf, s->len,
3037 PKT_INT, ssh->v1_local_protoflags, PKT_END);
3039 logevent("Trying to enable encryption...");
3043 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3044 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3046 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3047 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
3048 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
3050 ssh->crcda_ctx = crcda_make_context();
3051 logevent("Installing CRC compensation attack detector");
3053 if (servkey.modulus) {
3054 sfree(servkey.modulus);
3055 servkey.modulus = NULL;
3057 if (servkey.exponent) {
3058 sfree(servkey.exponent);
3059 servkey.exponent = NULL;
3061 if (hostkey.modulus) {
3062 sfree(hostkey.modulus);
3063 hostkey.modulus = NULL;
3065 if (hostkey.exponent) {
3066 sfree(hostkey.exponent);
3067 hostkey.exponent = NULL;
3071 if (pktin->type != SSH1_SMSG_SUCCESS) {
3072 bombout(("Encryption not successfully enabled"));
3076 logevent("Successfully started encryption");
3080 if (!*ssh->cfg.username) {
3081 if (ssh_get_line && !ssh_getline_pw_only) {
3082 if (!ssh_get_line("login as: ",
3083 s->username, sizeof(s->username), FALSE)) {
3085 * get_line failed to get a username.
3088 logevent("No username provided. Abandoning session.");
3089 ssh->close_expected = TRUE;
3090 ssh_closing((Plug)ssh, NULL, 0, 0);
3094 int ret; /* need not be kept over crReturn */
3095 c_write_str(ssh, "login as: ");
3098 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
3100 crWaitUntil(!pktin);
3101 ret = process_userpass_input(ssh, in, inlen);
3105 c_write_str(ssh, "\r\n");
3108 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
3109 s->username[sizeof(s->username)-1] = '\0';
3112 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
3114 char userlog[22 + sizeof(s->username)];
3115 sprintf(userlog, "Sent username \"%s\"", s->username);
3117 if (flags & FLAG_INTERACTIVE &&
3118 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3119 strcat(userlog, "\r\n");
3120 c_write_str(ssh, userlog);
3127 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
3128 /* We must not attempt PK auth. Pretend we've already tried it. */
3129 s->tried_publickey = s->tried_agent = 1;
3131 s->tried_publickey = s->tried_agent = 0;
3133 s->tis_auth_refused = s->ccard_auth_refused = 0;
3134 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
3135 if (!filename_is_null(ssh->cfg.keyfile)) {
3136 if (!rsakey_pubblob(&ssh->cfg.keyfile,
3137 &s->publickey_blob, &s->publickey_bloblen, NULL))
3138 s->publickey_blob = NULL;
3140 s->publickey_blob = NULL;
3142 while (pktin->type == SSH1_SMSG_FAILURE) {
3143 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
3145 if (agent_exists() && !s->tried_agent) {
3147 * Attempt RSA authentication using Pageant.
3153 logevent("Pageant is running. Requesting keys.");
3155 /* Request the keys held by the agent. */
3156 PUT_32BIT(s->request, 1);
3157 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
3158 if (!agent_query(s->request, 5, &r, &s->responselen,
3159 ssh_agent_callback, ssh)) {
3163 bombout(("Unexpected data from server while waiting"
3164 " for agent response"));
3167 } while (pktin || inlen > 0);
3168 r = ssh->agent_response;
3169 s->responselen = ssh->agent_response_len;
3171 s->response = (unsigned char *) r;
3172 if (s->response && s->responselen >= 5 &&
3173 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3174 s->p = s->response + 5;
3175 s->nkeys = GET_32BIT(s->p);
3177 logeventf(ssh, "Pageant has %d SSH1 keys", s->nkeys);
3178 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
3179 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
3180 if (s->publickey_blob &&
3181 !memcmp(s->p, s->publickey_blob,
3182 s->publickey_bloblen)) {
3183 logevent("This key matches configured key file");
3184 s->tried_publickey = 1;
3189 do { /* do while (0) to make breaking easy */
3190 n = ssh1_read_bignum
3191 (s->p, s->responselen-(s->p-s->response),
3196 n = ssh1_read_bignum
3197 (s->p, s->responselen-(s->p-s->response),
3202 if (s->responselen - (s->p-s->response) < 4)
3204 s->commentlen = GET_32BIT(s->p);
3206 if (s->responselen - (s->p-s->response) <
3209 s->commentp = (char *)s->p;
3210 s->p += s->commentlen;
3214 logevent("Pageant key list packet was truncated");
3218 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3219 PKT_BIGNUM, s->key.modulus, PKT_END);
3221 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3222 logevent("Key refused");
3225 logevent("Received RSA challenge");
3226 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3227 bombout(("Server's RSA challenge was badly formatted"));
3232 char *agentreq, *q, *ret;
3235 len = 1 + 4; /* message type, bit count */
3236 len += ssh1_bignum_length(s->key.exponent);
3237 len += ssh1_bignum_length(s->key.modulus);
3238 len += ssh1_bignum_length(s->challenge);
3239 len += 16; /* session id */
3240 len += 4; /* response format */
3241 agentreq = snewn(4 + len, char);
3242 PUT_32BIT(agentreq, len);
3244 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
3245 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
3247 q += ssh1_write_bignum(q, s->key.exponent);
3248 q += ssh1_write_bignum(q, s->key.modulus);
3249 q += ssh1_write_bignum(q, s->challenge);
3250 memcpy(q, s->session_id, 16);
3252 PUT_32BIT(q, 1); /* response format */
3253 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3254 ssh_agent_callback, ssh)) {
3259 bombout(("Unexpected data from server"
3260 " while waiting for agent"
3264 } while (pktin || inlen > 0);
3265 vret = ssh->agent_response;
3266 retlen = ssh->agent_response_len;
3271 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3272 logevent("Sending Pageant's response");
3273 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3274 PKT_DATA, ret + 5, 16,
3278 if (pktin->type == SSH1_SMSG_SUCCESS) {
3280 ("Pageant's response accepted");
3281 if (flags & FLAG_VERBOSE) {
3282 c_write_str(ssh, "Authenticated using"
3284 c_write(ssh, s->commentp,
3286 c_write_str(ssh, "\" from agent\r\n");
3291 ("Pageant's response not accepted");
3294 ("Pageant failed to answer challenge");
3298 logevent("No reply received from Pageant");
3301 freebn(s->key.exponent);
3302 freebn(s->key.modulus);
3303 freebn(s->challenge);
3312 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
3313 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
3315 if (ssh->cfg.try_tis_auth &&
3316 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3317 !s->tis_auth_refused) {
3318 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
3319 logevent("Requested TIS authentication");
3320 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
3322 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
3323 logevent("TIS authentication declined");
3324 if (flags & FLAG_INTERACTIVE)
3325 c_write_str(ssh, "TIS authentication refused.\r\n");
3326 s->tis_auth_refused = 1;
3332 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3334 bombout(("TIS challenge packet was badly formed"));
3337 logevent("Received TIS challenge");
3338 if (challengelen > sizeof(s->prompt) - 1)
3339 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3340 memcpy(s->prompt, challenge, challengelen);
3341 /* Prompt heuristic comes from OpenSSH */
3342 strncpy(s->prompt + challengelen,
3343 memchr(s->prompt, '\n', challengelen) ?
3344 "": "\r\nResponse: ",
3345 (sizeof s->prompt) - challengelen);
3346 s->prompt[(sizeof s->prompt) - 1] = '\0';
3349 if (ssh->cfg.try_tis_auth &&
3350 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3351 !s->ccard_auth_refused) {
3352 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
3353 logevent("Requested CryptoCard authentication");
3354 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
3356 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
3357 logevent("CryptoCard authentication declined");
3358 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3359 s->ccard_auth_refused = 1;
3365 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3367 bombout(("CryptoCard challenge packet was badly formed"));
3370 logevent("Received CryptoCard challenge");
3371 if (challengelen > sizeof(s->prompt) - 1)
3372 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3373 memcpy(s->prompt, challenge, challengelen);
3374 strncpy(s->prompt + challengelen,
3375 memchr(s->prompt, '\n', challengelen) ?
3376 "" : "\r\nResponse: ",
3377 sizeof(s->prompt) - challengelen);
3378 s->prompt[sizeof(s->prompt) - 1] = '\0';
3381 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3382 sprintf(s->prompt, "%.90s@%.90s's password: ",
3383 s->username, ssh->savedhost);
3385 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3386 char *comment = NULL;
3388 if (flags & FLAG_VERBOSE)
3389 c_write_str(ssh, "Trying public key authentication.\r\n");
3390 logeventf(ssh, "Trying public key \"%s\"",
3391 filename_to_str(&ssh->cfg.keyfile));
3392 type = key_type(&ssh->cfg.keyfile);
3393 if (type != SSH_KEYTYPE_SSH1) {
3394 char *msg = dupprintf("Key is of wrong type (%s)",
3395 key_type_to_str(type));
3397 c_write_str(ssh, msg);
3398 c_write_str(ssh, "\r\n");
3400 s->tried_publickey = 1;
3403 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
3404 if (flags & FLAG_VERBOSE)
3405 c_write_str(ssh, "No passphrase required.\r\n");
3408 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
3413 * Show password prompt, having first obtained it via a TIS
3414 * or CryptoCard exchange if we're doing TIS or CryptoCard
3418 if (!ssh_get_line(s->prompt, s->password,
3419 sizeof(s->password), TRUE)) {
3421 * get_line failed to get a password (for example
3422 * because one was supplied on the command line
3423 * which has already failed to work). Terminate.
3425 send_packet(ssh, SSH1_MSG_DISCONNECT,
3426 PKT_STR, "No more passwords available to try",
3428 logevent("Unable to authenticate");
3429 connection_fatal(ssh->frontend, "Unable to authenticate");
3430 ssh->close_expected = TRUE;
3431 ssh_closing((Plug)ssh, NULL, 0, 0);
3435 /* Prompt may have come from server. We've munged it a bit, so
3436 * we know it to be zero-terminated at least once. */
3437 int ret; /* need not be saved over crReturn */
3438 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3441 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
3443 crWaitUntil(!pktin);
3444 ret = process_userpass_input(ssh, in, inlen);
3448 c_write_str(ssh, "\r\n");
3452 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3454 * Try public key authentication with the specified
3457 s->tried_publickey = 1;
3460 const char *error = NULL;
3461 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3464 c_write_str(ssh, "Couldn't load private key from ");
3465 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
3466 c_write_str(ssh, " (");
3467 c_write_str(ssh, error);
3468 c_write_str(ssh, ").\r\n");
3469 continue; /* go and try password */
3472 c_write_str(ssh, "Wrong passphrase.\r\n");
3473 s->tried_publickey = 0;
3474 continue; /* try again */
3479 * Send a public key attempt.
3481 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3482 PKT_BIGNUM, s->key.modulus, PKT_END);
3485 if (pktin->type == SSH1_SMSG_FAILURE) {
3486 c_write_str(ssh, "Server refused our public key.\r\n");
3487 continue; /* go and try password */
3489 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3490 bombout(("Bizarre response to offer of public key"));
3496 unsigned char buffer[32];
3497 Bignum challenge, response;
3499 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3500 bombout(("Server's RSA challenge was badly formatted"));
3503 response = rsadecrypt(challenge, &s->key);
3504 freebn(s->key.private_exponent);/* burn the evidence */
3506 for (i = 0; i < 32; i++) {
3507 buffer[i] = bignum_byte(response, 31 - i);
3511 MD5Update(&md5c, buffer, 32);
3512 MD5Update(&md5c, s->session_id, 16);
3513 MD5Final(buffer, &md5c);
3515 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3516 PKT_DATA, buffer, 16, PKT_END);
3523 if (pktin->type == SSH1_SMSG_FAILURE) {
3524 if (flags & FLAG_VERBOSE)
3525 c_write_str(ssh, "Failed to authenticate with"
3526 " our public key.\r\n");
3527 continue; /* go and try password */
3528 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3529 bombout(("Bizarre response to RSA authentication response"));
3533 break; /* we're through! */
3535 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3537 * Defence against traffic analysis: we send a
3538 * whole bunch of packets containing strings of
3539 * different lengths. One of these strings is the
3540 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3541 * The others are all random data in
3542 * SSH1_MSG_IGNORE packets. This way a passive
3543 * listener can't tell which is the password, and
3544 * hence can't deduce the password length.
3546 * Anybody with a password length greater than 16
3547 * bytes is going to have enough entropy in their
3548 * password that a listener won't find it _that_
3549 * much help to know how long it is. So what we'll
3552 * - if password length < 16, we send 15 packets
3553 * containing string lengths 1 through 15
3555 * - otherwise, we let N be the nearest multiple
3556 * of 8 below the password length, and send 8
3557 * packets containing string lengths N through
3558 * N+7. This won't obscure the order of
3559 * magnitude of the password length, but it will
3560 * introduce a bit of extra uncertainty.
3562 * A few servers (the old 1.2.18 through 1.2.22)
3563 * can't deal with SSH1_MSG_IGNORE. For these
3564 * servers, we need an alternative defence. We make
3565 * use of the fact that the password is interpreted
3566 * as a C string: so we can append a NUL, then some
3569 * One server (a Cisco one) can deal with neither
3570 * SSH1_MSG_IGNORE _nor_ a padded password string.
3571 * For this server we are left with no defences
3572 * against password length sniffing.
3574 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
3576 * The server can deal with SSH1_MSG_IGNORE, so
3577 * we can use the primary defence.
3579 int bottom, top, pwlen, i;
3582 pwlen = strlen(s->password);
3584 bottom = 0; /* zero length passwords are OK! :-) */
3587 bottom = pwlen & ~7;
3591 assert(pwlen >= bottom && pwlen <= top);
3593 randomstr = snewn(top + 1, char);
3595 for (i = bottom; i <= top; i++) {
3597 defer_packet(ssh, s->pwpkt_type,
3598 PKTT_PASSWORD, PKT_STR, s->password,
3599 PKTT_OTHER, PKT_END);
3601 for (j = 0; j < i; j++) {
3603 randomstr[j] = random_byte();
3604 } while (randomstr[j] == '\0');
3606 randomstr[i] = '\0';
3607 defer_packet(ssh, SSH1_MSG_IGNORE,
3608 PKT_STR, randomstr, PKT_END);
3611 logevent("Sending password with camouflage packets");
3612 ssh_pkt_defersend(ssh);
3615 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3617 * The server can't deal with SSH1_MSG_IGNORE
3618 * but can deal with padded passwords, so we
3619 * can use the secondary defence.
3625 len = strlen(s->password);
3626 if (len < sizeof(string)) {
3628 strcpy(string, s->password);
3629 len++; /* cover the zero byte */
3630 while (len < sizeof(string)) {
3631 string[len++] = (char) random_byte();
3636 logevent("Sending length-padded password");
3637 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3638 PKT_INT, len, PKT_DATA, ss, len,
3639 PKTT_OTHER, PKT_END);
3642 * The server has _both_
3643 * BUG_CHOKES_ON_SSH1_IGNORE and
3644 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3645 * therefore nothing we can do.
3648 len = strlen(s->password);
3649 logevent("Sending unpadded password");
3650 send_packet(ssh, s->pwpkt_type,
3651 PKTT_PASSWORD, PKT_INT, len,
3652 PKT_DATA, s->password, len,
3653 PKTT_OTHER, PKT_END);
3656 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3657 PKT_STR, s->password, PKTT_OTHER, PKT_END);
3660 logevent("Sent password");
3661 memset(s->password, 0, strlen(s->password));
3663 if (pktin->type == SSH1_SMSG_FAILURE) {
3664 if (flags & FLAG_VERBOSE)
3665 c_write_str(ssh, "Access denied\r\n");
3666 logevent("Authentication refused");
3667 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3668 bombout(("Strange packet received, type %d", pktin->type));
3673 logevent("Authentication successful");
3678 void sshfwd_close(struct ssh_channel *c)
3682 if (ssh->state != SSH_STATE_SESSION) {
3683 assert(ssh->state == SSH_STATE_CLOSED);
3687 if (c && !c->closes) {
3689 * If halfopen is true, we have sent
3690 * CHANNEL_OPEN for this channel, but it hasn't even been
3691 * acknowledged by the server. So we must set a close flag
3692 * on it now, and then when the server acks the channel
3693 * open, we can close it then.
3696 if (ssh->version == 1) {
3697 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3700 struct Packet *pktout;
3701 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3702 ssh2_pkt_adduint32(pktout, c->remoteid);
3703 ssh2_pkt_send(ssh, pktout);
3706 c->closes = 1; /* sent MSG_CLOSE */
3707 if (c->type == CHAN_X11) {
3709 logevent("Forwarded X11 connection terminated");
3710 } else if (c->type == CHAN_SOCKDATA ||
3711 c->type == CHAN_SOCKDATA_DORMANT) {
3713 logevent("Forwarded port closed");
3718 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3722 if (ssh->state != SSH_STATE_SESSION) {
3723 assert(ssh->state == SSH_STATE_CLOSED);
3727 if (ssh->version == 1) {
3728 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3729 PKT_INT, c->remoteid,
3731 PKT_INT, len, PKT_DATA, buf, len,
3732 PKTT_OTHER, PKT_END);
3734 * In SSH1 we can return 0 here - implying that forwarded
3735 * connections are never individually throttled - because
3736 * the only circumstance that can cause throttling will be
3737 * the whole SSH connection backing up, in which case
3738 * _everything_ will be throttled as a whole.
3742 ssh2_add_channel_data(c, buf, len);
3743 return ssh2_try_send(c);
3747 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3751 if (ssh->state != SSH_STATE_SESSION) {
3752 assert(ssh->state == SSH_STATE_CLOSED);
3756 if (ssh->version == 1) {
3757 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3758 c->v.v1.throttling = 0;
3759 ssh1_throttle(ssh, -1);
3762 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3766 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
3768 struct queued_handler *qh = ssh->qhead;
3772 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
3775 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
3776 ssh->packet_dispatch[qh->msg1] = NULL;
3779 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
3780 ssh->packet_dispatch[qh->msg2] = NULL;
3784 ssh->qhead = qh->next;
3786 if (ssh->qhead->msg1 > 0) {
3787 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
3788 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
3790 if (ssh->qhead->msg2 > 0) {
3791 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
3792 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
3795 ssh->qhead = ssh->qtail = NULL;
3796 ssh->packet_dispatch[pktin->type] = NULL;
3799 qh->handler(ssh, pktin, qh->ctx);
3804 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
3805 chandler_fn_t handler, void *ctx)
3807 struct queued_handler *qh;
3809 qh = snew(struct queued_handler);
3812 qh->handler = handler;
3816 if (ssh->qtail == NULL) {
3820 assert(ssh->packet_dispatch[qh->msg1] == NULL);
3821 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
3824 assert(ssh->packet_dispatch[qh->msg2] == NULL);
3825 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
3828 ssh->qtail->next = qh;
3833 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
3835 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
3837 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
3838 SSH2_MSG_REQUEST_SUCCESS)) {
3839 logeventf(ssh, "Remote port forwarding from %s enabled",
3842 logeventf(ssh, "Remote port forwarding from %s refused",
3845 rpf = del234(ssh->rportfwds, pf);
3851 static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
3853 const char *portfwd_strptr = cfg->portfwd;
3854 struct ssh_portfwd *epf;
3857 if (!ssh->portfwds) {
3858 ssh->portfwds = newtree234(ssh_portcmp);
3861 * Go through the existing port forwardings and tag them
3862 * with status==DESTROY. Any that we want to keep will be
3863 * re-enabled (status==KEEP) as we go through the
3864 * configuration and find out which bits are the same as
3867 struct ssh_portfwd *epf;
3869 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3870 epf->status = DESTROY;
3873 while (*portfwd_strptr) {
3874 char address_family, type;
3875 int sport,dport,sserv,dserv;
3876 char sports[256], dports[256], saddr[256], host[256];
3879 address_family = 'A';
3881 if (*portfwd_strptr == 'A' ||
3882 *portfwd_strptr == '4' ||
3883 *portfwd_strptr == '6')
3884 address_family = *portfwd_strptr++;
3885 if (*portfwd_strptr == 'L' ||
3886 *portfwd_strptr == 'R' ||
3887 *portfwd_strptr == 'D')
3888 type = *portfwd_strptr++;
3893 while (*portfwd_strptr && *portfwd_strptr != '\t') {
3894 if (*portfwd_strptr == ':') {
3896 * We've seen a colon in the middle of the
3897 * source port number. This means that
3898 * everything we've seen until now is the
3899 * source _address_, so we'll move it into
3900 * saddr and start sports from the beginning
3905 if (ssh->version == 1 && type == 'R') {
3906 logeventf(ssh, "SSH1 cannot handle remote source address "
3907 "spec \"%s\"; ignoring", sports);
3909 strcpy(saddr, sports);
3912 if (n < 255) sports[n++] = *portfwd_strptr++;
3916 if (*portfwd_strptr == '\t')
3919 while (*portfwd_strptr && *portfwd_strptr != ':') {
3920 if (n < 255) host[n++] = *portfwd_strptr++;
3923 if (*portfwd_strptr == ':')
3926 while (*portfwd_strptr) {
3927 if (n < 255) dports[n++] = *portfwd_strptr++;
3931 dport = atoi(dports);
3935 dport = net_service_lookup(dports);
3937 logeventf(ssh, "Service lookup failed for destination"
3938 " port \"%s\"", dports);
3942 while (*portfwd_strptr) portfwd_strptr++;
3946 portfwd_strptr++; /* eat the NUL and move to next one */
3948 sport = atoi(sports);
3952 sport = net_service_lookup(sports);
3954 logeventf(ssh, "Service lookup failed for source"
3955 " port \"%s\"", sports);
3958 if (sport && dport) {
3959 /* Set up a description of the source port. */
3960 struct ssh_portfwd *pfrec, *epfrec;
3962 pfrec = snew(struct ssh_portfwd);
3964 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
3965 pfrec->sserv = sserv ? dupstr(sports) : NULL;
3966 pfrec->sport = sport;
3967 pfrec->daddr = *host ? dupstr(host) : NULL;
3968 pfrec->dserv = dserv ? dupstr(dports) : NULL;
3969 pfrec->dport = dport;
3970 pfrec->local = NULL;
3971 pfrec->remote = NULL;
3972 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
3973 address_family == '6' ? ADDRTYPE_IPV6 :
3976 epfrec = add234(ssh->portfwds, pfrec);
3977 if (epfrec != pfrec) {
3979 * We already have a port forwarding with precisely
3980 * these parameters. Hence, no need to do anything;
3981 * simply tag the existing one as KEEP.
3983 epfrec->status = KEEP;
3984 free_portfwd(pfrec);
3986 pfrec->status = CREATE;
3992 * Now go through and destroy any port forwardings which were
3995 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3996 if (epf->status == DESTROY) {
3999 message = dupprintf("%s port forwarding from %s%s%d",
4000 epf->type == 'L' ? "local" :
4001 epf->type == 'R' ? "remote" : "dynamic",
4002 epf->saddr ? epf->saddr : "",
4003 epf->saddr ? ":" : "",
4006 if (epf->type != 'D') {
4007 char *msg2 = dupprintf("%s to %s:%d", message,
4008 epf->daddr, epf->dport);
4013 logeventf(ssh, "Cancelling %s", message);
4017 struct ssh_rportfwd *rpf = epf->remote;
4018 struct Packet *pktout;
4021 * Cancel the port forwarding at the server
4024 if (ssh->version == 1) {
4026 * We cannot cancel listening ports on the
4027 * server side in SSH1! There's no message
4028 * to support it. Instead, we simply remove
4029 * the rportfwd record from the local end
4030 * so that any connections the server tries
4031 * to make on it are rejected.
4034 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4035 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
4036 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
4038 ssh2_pkt_addstring(pktout, epf->saddr);
4039 } else if (ssh->cfg.rport_acceptall) {
4040 /* XXX: ssh->cfg.rport_acceptall may not represent
4041 * what was used to open the original connection,
4042 * since it's reconfigurable. */
4043 ssh2_pkt_addstring(pktout, "0.0.0.0");
4045 ssh2_pkt_addstring(pktout, "127.0.0.1");
4047 ssh2_pkt_adduint32(pktout, epf->sport);
4048 ssh2_pkt_send(ssh, pktout);
4051 del234(ssh->rportfwds, rpf);
4053 } else if (epf->local) {
4054 pfd_terminate(epf->local);
4057 delpos234(ssh->portfwds, i);
4059 i--; /* so we don't skip one in the list */
4063 * And finally, set up any new port forwardings (status==CREATE).
4065 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4066 if (epf->status == CREATE) {
4067 char *sportdesc, *dportdesc;
4068 sportdesc = dupprintf("%s%s%s%s%d%s",
4069 epf->saddr ? epf->saddr : "",
4070 epf->saddr ? ":" : "",
4071 epf->sserv ? epf->sserv : "",
4072 epf->sserv ? "(" : "",
4074 epf->sserv ? ")" : "");
4075 if (epf->type == 'D') {
4078 dportdesc = dupprintf("%s:%s%s%d%s",
4080 epf->dserv ? epf->dserv : "",
4081 epf->dserv ? "(" : "",
4083 epf->dserv ? ")" : "");
4086 if (epf->type == 'L') {
4087 const char *err = pfd_addforward(epf->daddr, epf->dport,
4088 epf->saddr, epf->sport,
4091 epf->addressfamily);
4093 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
4094 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4095 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4096 sportdesc, dportdesc,
4097 err ? " failed: " : "", err ? err : "");
4098 } else if (epf->type == 'D') {
4099 const char *err = pfd_addforward(NULL, -1,
4100 epf->saddr, epf->sport,
4103 epf->addressfamily);
4105 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
4106 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4107 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4109 err ? " failed: " : "", err ? err : "");
4111 struct ssh_rportfwd *pf;
4114 * Ensure the remote port forwardings tree exists.
4116 if (!ssh->rportfwds) {
4117 if (ssh->version == 1)
4118 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
4120 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4123 pf = snew(struct ssh_rportfwd);
4124 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
4125 pf->dhost[lenof(pf->dhost)-1] = '\0';
4126 pf->dport = epf->dport;
4127 pf->sport = epf->sport;
4128 if (add234(ssh->rportfwds, pf) != pf) {
4129 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
4130 epf->daddr, epf->dport);
4133 logeventf(ssh, "Requesting remote port %s"
4134 " forward to %s", sportdesc, dportdesc);
4136 pf->sportdesc = sportdesc;
4141 if (ssh->version == 1) {
4142 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
4143 PKT_INT, epf->sport,
4144 PKT_STR, epf->daddr,
4145 PKT_INT, epf->dport,
4147 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4149 ssh_rportfwd_succfail, pf);
4151 struct Packet *pktout;
4152 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4153 ssh2_pkt_addstring(pktout, "tcpip-forward");
4154 ssh2_pkt_addbool(pktout, 1);/* want reply */
4156 ssh2_pkt_addstring(pktout, epf->saddr);
4157 } else if (cfg->rport_acceptall) {
4158 ssh2_pkt_addstring(pktout, "0.0.0.0");
4160 ssh2_pkt_addstring(pktout, "127.0.0.1");
4162 ssh2_pkt_adduint32(pktout, epf->sport);
4163 ssh2_pkt_send(ssh, pktout);
4165 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4166 SSH2_MSG_REQUEST_FAILURE,
4167 ssh_rportfwd_succfail, pf);
4176 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4179 int stringlen, bufsize;
4181 ssh_pkt_getstring(pktin, &string, &stringlen);
4182 if (string == NULL) {
4183 bombout(("Incoming terminal data packet was badly formed"));
4187 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4189 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4190 ssh->v1_stdout_throttling = 1;
4191 ssh1_throttle(ssh, +1);
4195 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4197 /* Remote side is trying to open a channel to talk to our
4198 * X-Server. Give them back a local channel number. */
4199 struct ssh_channel *c;
4200 int remoteid = ssh_pkt_getuint32(pktin);
4202 logevent("Received X11 connect request");
4203 /* Refuse if X11 forwarding is disabled. */
4204 if (!ssh->X11_fwd_enabled) {
4205 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4206 PKT_INT, remoteid, PKT_END);
4207 logevent("Rejected X11 connect request");
4209 c = snew(struct ssh_channel);
4212 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
4213 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
4214 logevent("Opening X11 forward connection failed");
4216 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4217 PKT_INT, remoteid, PKT_END);
4220 ("Opening X11 forward connection succeeded");
4221 c->remoteid = remoteid;
4222 c->halfopen = FALSE;
4223 c->localid = alloc_channel_id(ssh);
4225 c->v.v1.throttling = 0;
4226 c->type = CHAN_X11; /* identify channel type */
4227 add234(ssh->channels, c);
4228 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4229 PKT_INT, c->remoteid, PKT_INT,
4230 c->localid, PKT_END);
4231 logevent("Opened X11 forward channel");
4236 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4238 /* Remote side is trying to open a channel to talk to our
4239 * agent. Give them back a local channel number. */
4240 struct ssh_channel *c;
4241 int remoteid = ssh_pkt_getuint32(pktin);
4243 /* Refuse if agent forwarding is disabled. */
4244 if (!ssh->agentfwd_enabled) {
4245 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4246 PKT_INT, remoteid, PKT_END);
4248 c = snew(struct ssh_channel);
4250 c->remoteid = remoteid;
4251 c->halfopen = FALSE;
4252 c->localid = alloc_channel_id(ssh);
4254 c->v.v1.throttling = 0;
4255 c->type = CHAN_AGENT; /* identify channel type */
4256 c->u.a.lensofar = 0;
4257 add234(ssh->channels, c);
4258 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4259 PKT_INT, c->remoteid, PKT_INT, c->localid,
4264 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4266 /* Remote side is trying to open a channel to talk to a
4267 * forwarded port. Give them back a local channel number. */
4268 struct ssh_channel *c;
4269 struct ssh_rportfwd pf, *pfp;
4274 c = snew(struct ssh_channel);
4277 remoteid = ssh_pkt_getuint32(pktin);
4278 ssh_pkt_getstring(pktin, &host, &hostsize);
4279 port = ssh_pkt_getuint32(pktin);
4281 if (hostsize >= lenof(pf.dhost))
4282 hostsize = lenof(pf.dhost)-1;
4283 memcpy(pf.dhost, host, hostsize);
4284 pf.dhost[hostsize] = '\0';
4286 pfp = find234(ssh->rportfwds, &pf, NULL);
4289 logeventf(ssh, "Rejected remote port open request for %s:%d",
4291 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4292 PKT_INT, remoteid, PKT_END);
4294 logeventf(ssh, "Received remote port open request for %s:%d",
4296 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
4297 c, &ssh->cfg, pfp->pfrec->addressfamily);
4299 logeventf(ssh, "Port open failed: %s", e);
4301 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4302 PKT_INT, remoteid, PKT_END);
4304 c->remoteid = remoteid;
4305 c->halfopen = FALSE;
4306 c->localid = alloc_channel_id(ssh);
4308 c->v.v1.throttling = 0;
4309 c->type = CHAN_SOCKDATA; /* identify channel type */
4310 add234(ssh->channels, c);
4311 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4312 PKT_INT, c->remoteid, PKT_INT,
4313 c->localid, PKT_END);
4314 logevent("Forwarded port opened successfully");
4319 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4321 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4322 unsigned int localid = ssh_pkt_getuint32(pktin);
4323 struct ssh_channel *c;
4325 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4326 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4327 c->remoteid = localid;
4328 c->halfopen = FALSE;
4329 c->type = CHAN_SOCKDATA;
4330 c->v.v1.throttling = 0;
4331 pfd_confirm(c->u.pfd.s);
4334 if (c && c->closes) {
4336 * We have a pending close on this channel,
4337 * which we decided on before the server acked
4338 * the channel open. So now we know the
4339 * remoteid, we can close it again.
4341 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4342 PKT_INT, c->remoteid, PKT_END);
4346 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4348 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4349 struct ssh_channel *c;
4351 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4352 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4353 logevent("Forwarded connection refused by server");
4354 pfd_close(c->u.pfd.s);
4355 del234(ssh->channels, c);
4360 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4362 /* Remote side closes a channel. */
4363 unsigned i = ssh_pkt_getuint32(pktin);
4364 struct ssh_channel *c;
4365 c = find234(ssh->channels, &i, ssh_channelfind);
4366 if (c && !c->halfopen) {
4369 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4371 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4372 logevent("Forwarded X11 connection terminated");
4373 assert(c->u.x11.s != NULL);
4374 x11_close(c->u.x11.s);
4377 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4378 logevent("Forwarded port closed");
4379 assert(c->u.pfd.s != NULL);
4380 pfd_close(c->u.pfd.s);
4384 c->closes |= (closetype << 2); /* seen this message */
4385 if (!(c->closes & closetype)) {
4386 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4388 c->closes |= closetype; /* sent it too */
4391 if (c->closes == 15) {
4392 del234(ssh->channels, c);
4396 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4397 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4398 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4403 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4405 /* Data sent down one of our channels. */
4406 int i = ssh_pkt_getuint32(pktin);
4409 struct ssh_channel *c;
4411 ssh_pkt_getstring(pktin, &p, &len);
4413 c = find234(ssh->channels, &i, ssh_channelfind);
4418 bufsize = x11_send(c->u.x11.s, p, len);
4421 bufsize = pfd_send(c->u.pfd.s, p, len);
4424 /* Data for an agent message. Buffer it. */
4426 if (c->u.a.lensofar < 4) {
4427 unsigned int l = min(4 - c->u.a.lensofar, len);
4428 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4432 c->u.a.lensofar += l;
4434 if (c->u.a.lensofar == 4) {
4436 4 + GET_32BIT(c->u.a.msglen);
4437 c->u.a.message = snewn(c->u.a.totallen,
4439 memcpy(c->u.a.message, c->u.a.msglen, 4);
4441 if (c->u.a.lensofar >= 4 && len > 0) {
4443 min(c->u.a.totallen - c->u.a.lensofar,
4445 memcpy(c->u.a.message + c->u.a.lensofar, p,
4449 c->u.a.lensofar += l;
4451 if (c->u.a.lensofar == c->u.a.totallen) {
4454 if (agent_query(c->u.a.message,
4457 ssh_agentf_callback, c))
4458 ssh_agentf_callback(c, reply, replylen);
4459 sfree(c->u.a.message);
4460 c->u.a.lensofar = 0;
4463 bufsize = 0; /* agent channels never back up */
4466 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4467 c->v.v1.throttling = 1;
4468 ssh1_throttle(ssh, +1);
4473 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
4475 ssh->exitcode = ssh_pkt_getuint32(pktin);
4476 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
4477 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4479 * In case `helpful' firewalls or proxies tack
4480 * extra human-readable text on the end of the
4481 * session which we might mistake for another
4482 * encrypted packet, we close the session once
4483 * we've sent EXIT_CONFIRMATION.
4485 ssh->close_expected = TRUE;
4486 ssh_closing((Plug)ssh, NULL, 0, 0);
4489 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
4490 struct Packet *pktin)
4492 crBegin(ssh->do_ssh1_connection_crstate);
4494 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
4495 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
4496 ssh1_smsg_stdout_stderr_data;
4498 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
4499 ssh1_msg_channel_open_confirmation;
4500 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
4501 ssh1_msg_channel_open_failure;
4502 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
4503 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
4504 ssh1_msg_channel_close;
4505 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
4506 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
4508 if (ssh->cfg.agentfwd && agent_exists()) {
4509 logevent("Requesting agent forwarding");
4510 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
4514 if (pktin->type != SSH1_SMSG_SUCCESS
4515 && pktin->type != SSH1_SMSG_FAILURE) {
4516 bombout(("Protocol confusion"));
4518 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4519 logevent("Agent forwarding refused");
4521 logevent("Agent forwarding enabled");
4522 ssh->agentfwd_enabled = TRUE;
4523 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
4527 if (ssh->cfg.x11_forward) {
4528 char proto[20], data[64];
4529 logevent("Requesting X11 forwarding");
4530 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
4531 data, sizeof(data), ssh->cfg.x11_auth);
4532 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
4533 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
4534 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4535 PKT_STR, proto, PKT_STR, data,
4536 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
4539 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4540 PKT_STR, proto, PKT_STR, data, PKT_END);
4545 if (pktin->type != SSH1_SMSG_SUCCESS
4546 && pktin->type != SSH1_SMSG_FAILURE) {
4547 bombout(("Protocol confusion"));
4549 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4550 logevent("X11 forwarding refused");
4552 logevent("X11 forwarding enabled");
4553 ssh->X11_fwd_enabled = TRUE;
4554 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
4558 ssh_setup_portfwd(ssh, &ssh->cfg);
4559 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
4561 if (!ssh->cfg.nopty) {
4562 /* Unpick the terminal-speed string. */
4563 /* XXX perhaps we should allow no speeds to be sent. */
4564 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4565 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
4566 /* Send the pty request. */
4567 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
4568 PKT_STR, ssh->cfg.termtype,
4569 PKT_INT, ssh->term_height,
4570 PKT_INT, ssh->term_width,
4571 PKT_INT, 0, PKT_INT, 0, /* width,height in pixels */
4572 PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */
4573 PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */
4574 PKT_CHAR, 0, PKT_END);
4575 ssh->state = SSH_STATE_INTERMED;
4579 if (pktin->type != SSH1_SMSG_SUCCESS
4580 && pktin->type != SSH1_SMSG_FAILURE) {
4581 bombout(("Protocol confusion"));
4583 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4584 c_write_str(ssh, "Server refused to allocate pty\r\n");
4585 ssh->editing = ssh->echoing = 1;
4587 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
4588 ssh->ospeed, ssh->ispeed);
4590 ssh->editing = ssh->echoing = 1;
4593 if (ssh->cfg.compression) {
4594 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
4598 if (pktin->type != SSH1_SMSG_SUCCESS
4599 && pktin->type != SSH1_SMSG_FAILURE) {
4600 bombout(("Protocol confusion"));
4602 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4603 c_write_str(ssh, "Server refused to compress\r\n");
4605 logevent("Started compression");
4606 ssh->v1_compressing = TRUE;
4607 ssh->cs_comp_ctx = zlib_compress_init();
4608 logevent("Initialised zlib (RFC1950) compression");
4609 ssh->sc_comp_ctx = zlib_decompress_init();
4610 logevent("Initialised zlib (RFC1950) decompression");
4614 * Start the shell or command.
4616 * Special case: if the first-choice command is an SSH2
4617 * subsystem (hence not usable here) and the second choice
4618 * exists, we fall straight back to that.
4621 char *cmd = ssh->cfg.remote_cmd_ptr;
4623 if (!cmd) cmd = ssh->cfg.remote_cmd;
4625 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4626 cmd = ssh->cfg.remote_cmd_ptr2;
4627 ssh->fallback_cmd = TRUE;
4630 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
4632 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
4633 logevent("Started session");
4636 ssh->state = SSH_STATE_SESSION;
4637 if (ssh->size_needed)
4638 ssh_size(ssh, ssh->term_width, ssh->term_height);
4639 if (ssh->eof_needed)
4640 ssh_special(ssh, TS_EOF);
4643 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
4645 ssh->channels = newtree234(ssh_channelcmp);
4649 * By this point, most incoming packets are already being
4650 * handled by the dispatch table, and we need only pay
4651 * attention to the unusual ones.
4656 if (pktin->type == SSH1_SMSG_SUCCESS) {
4657 /* may be from EXEC_SHELL on some servers */
4658 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4659 /* may be from EXEC_SHELL on some servers
4660 * if no pty is available or in other odd cases. Ignore */
4662 bombout(("Strange packet received: type %d", pktin->type));
4667 int len = min(inlen, 512);
4668 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4669 PKT_INT, len, PKT_DATA, in, len,
4670 PKTT_OTHER, PKT_END);
4681 * Handle the top-level SSH2 protocol.
4683 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4688 ssh_pkt_getstring(pktin, &msg, &msglen);
4689 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
4692 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4694 /* log reason code in disconnect message */
4698 ssh_pkt_getstring(pktin, &msg, &msglen);
4699 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4702 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
4704 /* Do nothing, because we're ignoring it! Duhh. */
4707 static void ssh1_protocol_setup(Ssh ssh)
4712 * Most messages are handled by the coroutines.
4714 for (i = 0; i < 256; i++)
4715 ssh->packet_dispatch[i] = NULL;
4718 * These special message types we install handlers for.
4720 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4721 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4722 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4725 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
4726 struct Packet *pktin)
4728 unsigned char *in=(unsigned char*)vin;
4729 if (ssh->state == SSH_STATE_CLOSED)
4732 if (pktin && ssh->packet_dispatch[pktin->type]) {
4733 ssh->packet_dispatch[pktin->type](ssh, pktin);
4737 if (!ssh->protocol_initial_phase_done) {
4738 if (do_ssh1_login(ssh, in, inlen, pktin))
4739 ssh->protocol_initial_phase_done = TRUE;
4744 do_ssh1_connection(ssh, in, inlen, pktin);
4748 * Utility routine for decoding comma-separated strings in KEXINIT.
4750 static int in_commasep_string(char *needle, char *haystack, int haylen)
4753 if (!needle || !haystack) /* protect against null pointers */
4755 needlen = strlen(needle);
4758 * Is it at the start of the string?
4760 if (haylen >= needlen && /* haystack is long enough */
4761 !memcmp(needle, haystack, needlen) && /* initial match */
4762 (haylen == needlen || haystack[needlen] == ',')
4763 /* either , or EOS follows */
4767 * If not, search for the next comma and resume after that.
4768 * If no comma found, terminate.
4770 while (haylen > 0 && *haystack != ',')
4771 haylen--, haystack++;
4774 haylen--, haystack++; /* skip over comma itself */
4779 * Similar routine for checking whether we have the first string in a list.
4781 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
4784 if (!needle || !haystack) /* protect against null pointers */
4786 needlen = strlen(needle);
4788 * Is it at the start of the string?
4790 if (haylen >= needlen && /* haystack is long enough */
4791 !memcmp(needle, haystack, needlen) && /* initial match */
4792 (haylen == needlen || haystack[needlen] == ',')
4793 /* either , or EOS follows */
4801 * SSH2 key creation method.
4803 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4804 unsigned char *sessid, char chr,
4805 unsigned char *keyspace)
4808 /* First 20 bytes. */
4810 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4812 SHA_Bytes(&s, H, 20);
4813 SHA_Bytes(&s, &chr, 1);
4814 SHA_Bytes(&s, sessid, 20);
4815 SHA_Final(&s, keyspace);
4816 /* Next 20 bytes. */
4818 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4820 SHA_Bytes(&s, H, 20);
4821 SHA_Bytes(&s, keyspace, 20);
4822 SHA_Final(&s, keyspace + 20);
4826 * Handle the SSH2 transport layer.
4828 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
4829 struct Packet *pktin)
4831 unsigned char *in = (unsigned char *)vin;
4832 struct do_ssh2_transport_state {
4833 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
4834 Bignum p, g, e, f, K;
4835 int kex_init_value, kex_reply_value;
4836 const struct ssh_mac **maclist;
4838 const struct ssh2_cipher *cscipher_tobe;
4839 const struct ssh2_cipher *sccipher_tobe;
4840 const struct ssh_mac *csmac_tobe;
4841 const struct ssh_mac *scmac_tobe;
4842 const struct ssh_compress *cscomp_tobe;
4843 const struct ssh_compress *sccomp_tobe;
4844 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4845 int hostkeylen, siglen;
4846 void *hkey; /* actual host key */
4847 unsigned char exchange_hash[20];
4848 int n_preferred_kex;
4849 const struct ssh_kex *preferred_kex[KEX_MAX];
4850 int n_preferred_ciphers;
4851 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4852 const struct ssh_compress *preferred_comp;
4853 int got_session_id, activated_authconn;
4854 struct Packet *pktout;
4859 crState(do_ssh2_transport_state);
4861 crBegin(ssh->do_ssh2_transport_crstate);
4863 s->cscipher_tobe = s->sccipher_tobe = NULL;
4864 s->csmac_tobe = s->scmac_tobe = NULL;
4865 s->cscomp_tobe = s->sccomp_tobe = NULL;
4867 s->got_session_id = s->activated_authconn = FALSE;
4870 * Be prepared to work around the buggy MAC problem.
4872 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4873 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
4875 s->maclist = macs, s->nmacs = lenof(macs);
4878 ssh->pkt_ctx &= ~SSH2_PKTCTX_KEX_MASK;
4880 int i, j, commalist_started;
4883 * Set up the preferred key exchange. (NULL => warn below here)
4885 s->n_preferred_kex = 0;
4886 for (i = 0; i < KEX_MAX; i++) {
4887 switch (ssh->cfg.ssh_kexlist[i]) {
4889 s->preferred_kex[s->n_preferred_kex++] =
4890 &ssh_diffiehellman_gex;
4893 s->preferred_kex[s->n_preferred_kex++] =
4894 &ssh_diffiehellman_group14;
4897 s->preferred_kex[s->n_preferred_kex++] =
4898 &ssh_diffiehellman_group1;
4901 /* Flag for later. Don't bother if it's the last in
4903 if (i < KEX_MAX - 1) {
4904 s->preferred_kex[s->n_preferred_kex++] = NULL;
4911 * Set up the preferred ciphers. (NULL => warn below here)
4913 s->n_preferred_ciphers = 0;
4914 for (i = 0; i < CIPHER_MAX; i++) {
4915 switch (ssh->cfg.ssh_cipherlist[i]) {
4916 case CIPHER_BLOWFISH:
4917 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
4920 if (ssh->cfg.ssh2_des_cbc) {
4921 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
4925 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
4928 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
4931 /* Flag for later. Don't bother if it's the last in
4933 if (i < CIPHER_MAX - 1) {
4934 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
4941 * Set up preferred compression.
4943 if (ssh->cfg.compression)
4944 s->preferred_comp = &ssh_zlib;
4946 s->preferred_comp = &ssh_comp_none;
4949 * Enable queueing of outgoing auth- or connection-layer
4950 * packets while we are in the middle of a key exchange.
4952 ssh->queueing = TRUE;
4955 * Flag that KEX is in progress.
4957 ssh->kex_in_progress = TRUE;
4960 * Construct and send our key exchange packet.
4962 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
4963 for (i = 0; i < 16; i++)
4964 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
4965 /* List key exchange algorithms. */
4966 ssh2_pkt_addstring_start(s->pktout);
4967 commalist_started = 0;
4968 for (i = 0; i < s->n_preferred_kex; i++) {
4969 const struct ssh_kex *k = s->preferred_kex[i];
4970 if (!k) continue; /* warning flag */
4971 if (commalist_started)
4972 ssh2_pkt_addstring_str(s->pktout, ",");
4973 ssh2_pkt_addstring_str(s->pktout, s->preferred_kex[i]->name);
4974 commalist_started = 1;
4976 /* List server host key algorithms. */
4977 ssh2_pkt_addstring_start(s->pktout);
4978 for (i = 0; i < lenof(hostkey_algs); i++) {
4979 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
4980 if (i < lenof(hostkey_algs) - 1)
4981 ssh2_pkt_addstring_str(s->pktout, ",");
4983 /* List client->server encryption algorithms. */
4984 ssh2_pkt_addstring_start(s->pktout);
4985 commalist_started = 0;
4986 for (i = 0; i < s->n_preferred_ciphers; i++) {
4987 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4988 if (!c) continue; /* warning flag */
4989 for (j = 0; j < c->nciphers; j++) {
4990 if (commalist_started)
4991 ssh2_pkt_addstring_str(s->pktout, ",");
4992 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
4993 commalist_started = 1;
4996 /* List server->client encryption algorithms. */
4997 ssh2_pkt_addstring_start(s->pktout);
4998 commalist_started = 0;
4999 for (i = 0; i < s->n_preferred_ciphers; i++) {
5000 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5001 if (!c) continue; /* warning flag */
5002 for (j = 0; j < c->nciphers; j++) {
5003 if (commalist_started)
5004 ssh2_pkt_addstring_str(s->pktout, ",");
5005 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5006 commalist_started = 1;
5009 /* List client->server MAC algorithms. */
5010 ssh2_pkt_addstring_start(s->pktout);
5011 for (i = 0; i < s->nmacs; i++) {
5012 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5013 if (i < s->nmacs - 1)
5014 ssh2_pkt_addstring_str(s->pktout, ",");
5016 /* List server->client MAC algorithms. */
5017 ssh2_pkt_addstring_start(s->pktout);
5018 for (i = 0; i < s->nmacs; i++) {
5019 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5020 if (i < s->nmacs - 1)
5021 ssh2_pkt_addstring_str(s->pktout, ",");
5023 /* List client->server compression algorithms. */
5024 ssh2_pkt_addstring_start(s->pktout);
5025 assert(lenof(compressions) > 1);
5026 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5027 for (i = 0; i < lenof(compressions); i++) {
5028 const struct ssh_compress *c = compressions[i];
5029 if (c != s->preferred_comp) {
5030 ssh2_pkt_addstring_str(s->pktout, ",");
5031 ssh2_pkt_addstring_str(s->pktout, c->name);
5034 /* List server->client compression algorithms. */
5035 ssh2_pkt_addstring_start(s->pktout);
5036 assert(lenof(compressions) > 1);
5037 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5038 for (i = 0; i < lenof(compressions); i++) {
5039 const struct ssh_compress *c = compressions[i];
5040 if (c != s->preferred_comp) {
5041 ssh2_pkt_addstring_str(s->pktout, ",");
5042 ssh2_pkt_addstring_str(s->pktout, c->name);
5045 /* List client->server languages. Empty list. */
5046 ssh2_pkt_addstring_start(s->pktout);
5047 /* List server->client languages. Empty list. */
5048 ssh2_pkt_addstring_start(s->pktout);
5049 /* First KEX packet does _not_ follow, because we're not that brave. */
5050 ssh2_pkt_addbool(s->pktout, FALSE);
5052 ssh2_pkt_adduint32(s->pktout, 0);
5055 ssh->exhash = ssh->exhashbase;
5056 sha_string(&ssh->exhash, s->pktout->data + 5, s->pktout->length - 5);
5058 ssh2_pkt_send_noqueue(ssh, s->pktout);
5062 if (pktin->length > 5)
5063 sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5);
5066 * Now examine the other side's KEXINIT to see what we're up
5070 char *str, *preferred;
5073 if (pktin->type != SSH2_MSG_KEXINIT) {
5074 bombout(("expected key exchange packet from server"));
5078 ssh->hostkey = NULL;
5079 s->cscipher_tobe = NULL;
5080 s->sccipher_tobe = NULL;
5081 s->csmac_tobe = NULL;
5082 s->scmac_tobe = NULL;
5083 s->cscomp_tobe = NULL;
5084 s->sccomp_tobe = NULL;
5085 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
5087 pktin->savedpos += 16; /* skip garbage cookie */
5088 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
5091 for (i = 0; i < s->n_preferred_kex; i++) {
5092 const struct ssh_kex *k = s->preferred_kex[i];
5096 if (!preferred) preferred = k->name;
5097 if (in_commasep_string(k->name, str, len))
5104 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5105 str ? str : "(null)"));
5109 * Note that the server's guess is considered wrong if it doesn't match
5110 * the first algorithm in our list, even if it's still the algorithm
5113 s->guessok = first_in_commasep_string(preferred, str, len);
5114 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
5115 for (i = 0; i < lenof(hostkey_algs); i++) {
5116 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5117 ssh->hostkey = hostkey_algs[i];
5121 s->guessok = s->guessok &&
5122 first_in_commasep_string(hostkey_algs[0]->name, str, len);
5123 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
5124 for (i = 0; i < s->n_preferred_ciphers; i++) {
5125 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5127 s->warn_cscipher = TRUE;
5129 for (j = 0; j < c->nciphers; j++) {
5130 if (in_commasep_string(c->list[j]->name, str, len)) {
5131 s->cscipher_tobe = c->list[j];
5136 if (s->cscipher_tobe)
5139 if (!s->cscipher_tobe) {
5140 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
5141 str ? str : "(null)"));
5145 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
5146 for (i = 0; i < s->n_preferred_ciphers; i++) {
5147 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5149 s->warn_sccipher = TRUE;
5151 for (j = 0; j < c->nciphers; j++) {
5152 if (in_commasep_string(c->list[j]->name, str, len)) {
5153 s->sccipher_tobe = c->list[j];
5158 if (s->sccipher_tobe)
5161 if (!s->sccipher_tobe) {
5162 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
5163 str ? str : "(null)"));
5167 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
5168 for (i = 0; i < s->nmacs; i++) {
5169 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5170 s->csmac_tobe = s->maclist[i];
5174 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
5175 for (i = 0; i < s->nmacs; i++) {
5176 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5177 s->scmac_tobe = s->maclist[i];
5181 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
5182 for (i = 0; i < lenof(compressions) + 1; i++) {
5183 const struct ssh_compress *c =
5184 i == 0 ? s->preferred_comp : compressions[i - 1];
5185 if (in_commasep_string(c->name, str, len)) {
5190 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
5191 for (i = 0; i < lenof(compressions) + 1; i++) {
5192 const struct ssh_compress *c =
5193 i == 0 ? s->preferred_comp : compressions[i - 1];
5194 if (in_commasep_string(c->name, str, len)) {
5199 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5200 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
5201 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
5204 ssh_set_frozen(ssh, 1);
5205 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
5207 ssh_dialog_callback, ssh);
5208 if (s->dlgret < 0) {
5212 bombout(("Unexpected data from server while"
5213 " waiting for user response"));
5216 } while (pktin || inlen > 0);
5217 s->dlgret = ssh->user_response;
5219 ssh_set_frozen(ssh, 0);
5220 if (s->dlgret == 0) {
5221 ssh->close_expected = TRUE;
5222 ssh_closing((Plug)ssh, NULL, 0, 0);
5227 if (s->warn_cscipher) {
5228 ssh_set_frozen(ssh, 1);
5229 s->dlgret = askalg(ssh->frontend,
5230 "client-to-server cipher",
5231 s->cscipher_tobe->name,
5232 ssh_dialog_callback, ssh);
5233 if (s->dlgret < 0) {
5237 bombout(("Unexpected data from server while"
5238 " waiting for user response"));
5241 } while (pktin || inlen > 0);
5242 s->dlgret = ssh->user_response;
5244 ssh_set_frozen(ssh, 0);
5245 if (s->dlgret == 0) {
5246 ssh->close_expected = TRUE;
5247 ssh_closing((Plug)ssh, NULL, 0, 0);
5252 if (s->warn_sccipher) {
5253 ssh_set_frozen(ssh, 1);
5254 s->dlgret = askalg(ssh->frontend,
5255 "server-to-client cipher",
5256 s->sccipher_tobe->name,
5257 ssh_dialog_callback, ssh);
5258 if (s->dlgret < 0) {
5262 bombout(("Unexpected data from server while"
5263 " waiting for user response"));
5266 } while (pktin || inlen > 0);
5267 s->dlgret = ssh->user_response;
5269 ssh_set_frozen(ssh, 0);
5270 if (s->dlgret == 0) {
5271 ssh->close_expected = TRUE;
5272 ssh_closing((Plug)ssh, NULL, 0, 0);
5277 if (s->ignorepkt) /* first_kex_packet_follows */
5278 crWaitUntil(pktin); /* Ignore packet */
5282 * Work out the number of bits of key we will need from the key
5283 * exchange. We start with the maximum key length of either
5289 csbits = s->cscipher_tobe->keylen;
5290 scbits = s->sccipher_tobe->keylen;
5291 s->nbits = (csbits > scbits ? csbits : scbits);
5293 /* The keys only have 160-bit entropy, since they're based on
5294 * a SHA-1 hash. So cap the key size at 160 bits. */
5299 * If we're doing Diffie-Hellman group exchange, start by
5300 * requesting a group.
5302 if (!ssh->kex->pdata) {
5303 logevent("Doing Diffie-Hellman group exchange");
5304 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
5306 * Work out how big a DH group we will need to allow that
5309 s->pbits = 512 << ((s->nbits - 1) / 64);
5310 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5311 ssh2_pkt_adduint32(s->pktout, s->pbits);
5312 ssh2_pkt_send_noqueue(ssh, s->pktout);
5315 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
5316 bombout(("expected key exchange group packet from server"));
5319 s->p = ssh2_pkt_getmp(pktin);
5320 s->g = ssh2_pkt_getmp(pktin);
5321 if (!s->p || !s->g) {
5322 bombout(("unable to read mp-ints from incoming group packet"));
5325 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
5326 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5327 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
5329 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP;
5330 ssh->kex_ctx = dh_setup_group(ssh->kex);
5331 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5332 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
5333 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5334 ssh->kex->groupname);
5337 logevent("Doing Diffie-Hellman key exchange");
5339 * Now generate and send e for Diffie-Hellman.
5341 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
5342 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
5343 s->pktout = ssh2_pkt_init(s->kex_init_value);
5344 ssh2_pkt_addmp(s->pktout, s->e);
5345 ssh2_pkt_send_noqueue(ssh, s->pktout);
5347 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
5349 if (pktin->type != s->kex_reply_value) {
5350 bombout(("expected key exchange reply packet from server"));
5353 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
5354 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5355 s->f = ssh2_pkt_getmp(pktin);
5357 bombout(("unable to parse key exchange reply packet"));
5360 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
5362 s->K = dh_find_K(ssh->kex_ctx, s->f);
5364 /* We assume everything from now on will be quick, and it might
5365 * involve user interaction. */
5366 set_busy_status(ssh->frontend, BUSY_NOT);
5368 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
5369 if (ssh->kex == &ssh_diffiehellman_gex) {
5370 sha_uint32(&ssh->exhash, s->pbits);
5371 sha_mpint(&ssh->exhash, s->p);
5372 sha_mpint(&ssh->exhash, s->g);
5374 sha_mpint(&ssh->exhash, s->e);
5375 sha_mpint(&ssh->exhash, s->f);
5376 sha_mpint(&ssh->exhash, s->K);
5377 SHA_Final(&ssh->exhash, s->exchange_hash);
5379 dh_cleanup(ssh->kex_ctx);
5380 ssh->kex_ctx = NULL;
5383 debug(("Exchange hash is:\n"));
5384 dmemdump(s->exchange_hash, 20);
5387 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5389 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
5390 (char *)s->exchange_hash, 20)) {
5391 bombout(("Server's host key did not match the signature supplied"));
5396 * Authenticate remote host: verify host key. (We've already
5397 * checked the signature of the exchange hash.)
5399 s->keystr = ssh->hostkey->fmtkey(s->hkey);
5400 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
5401 ssh_set_frozen(ssh, 1);
5402 s->dlgret = verify_ssh_host_key(ssh->frontend,
5403 ssh->savedhost, ssh->savedport,
5404 ssh->hostkey->keytype, s->keystr,
5406 ssh_dialog_callback, ssh);
5407 if (s->dlgret < 0) {
5411 bombout(("Unexpected data from server while waiting"
5412 " for user host key response"));
5415 } while (pktin || inlen > 0);
5416 s->dlgret = ssh->user_response;
5418 ssh_set_frozen(ssh, 0);
5419 if (s->dlgret == 0) {
5420 ssh->close_expected = TRUE;
5421 ssh_closing((Plug)ssh, NULL, 0, 0);
5424 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5425 logevent("Host key fingerprint is:");
5426 logevent(s->fingerprint);
5428 sfree(s->fingerprint);
5430 ssh->hostkey->freekey(s->hkey);
5433 * The exchange hash from the very first key exchange is also
5434 * the session id, used in session key construction and
5437 if (!s->got_session_id) {
5438 memcpy(ssh->v2_session_id, s->exchange_hash,
5439 sizeof(s->exchange_hash));
5440 s->got_session_id = TRUE;
5444 * Send SSH2_MSG_NEWKEYS.
5446 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
5447 ssh2_pkt_send_noqueue(ssh, s->pktout);
5448 ssh->outgoing_data_size = 0; /* start counting from here */
5451 * We've sent client NEWKEYS, so create and initialise
5452 * client-to-server session keys.
5454 if (ssh->cs_cipher_ctx)
5455 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
5456 ssh->cscipher = s->cscipher_tobe;
5457 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
5459 if (ssh->cs_mac_ctx)
5460 ssh->csmac->free_context(ssh->cs_mac_ctx);
5461 ssh->csmac = s->csmac_tobe;
5462 ssh->cs_mac_ctx = ssh->csmac->make_context();
5464 if (ssh->cs_comp_ctx)
5465 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
5466 ssh->cscomp = s->cscomp_tobe;
5467 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
5470 * Set IVs on client-to-server keys. Here we use the exchange
5471 * hash from the _first_ key exchange.
5474 unsigned char keyspace[40];
5475 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
5476 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
5477 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
5478 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
5479 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
5480 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
5483 logeventf(ssh, "Initialised %.200s client->server encryption",
5484 ssh->cscipher->text_name);
5485 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
5486 ssh->csmac->text_name);
5487 if (ssh->cscomp->text_name)
5488 logeventf(ssh, "Initialised %s compression",
5489 ssh->cscomp->text_name);
5492 * Now our end of the key exchange is complete, we can send all
5493 * our queued higher-layer packets.
5495 ssh->queueing = FALSE;
5496 ssh2_pkt_queuesend(ssh);
5499 * Expect SSH2_MSG_NEWKEYS from server.
5502 if (pktin->type != SSH2_MSG_NEWKEYS) {
5503 bombout(("expected new-keys packet from server"));
5506 ssh->incoming_data_size = 0; /* start counting from here */
5509 * We've seen server NEWKEYS, so create and initialise
5510 * server-to-client session keys.
5512 if (ssh->sc_cipher_ctx)
5513 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
5514 ssh->sccipher = s->sccipher_tobe;
5515 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
5517 if (ssh->sc_mac_ctx)
5518 ssh->scmac->free_context(ssh->sc_mac_ctx);
5519 ssh->scmac = s->scmac_tobe;
5520 ssh->sc_mac_ctx = ssh->scmac->make_context();
5522 if (ssh->sc_comp_ctx)
5523 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
5524 ssh->sccomp = s->sccomp_tobe;
5525 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
5528 * Set IVs on server-to-client keys. Here we use the exchange
5529 * hash from the _first_ key exchange.
5532 unsigned char keyspace[40];
5533 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
5534 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
5535 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
5536 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
5537 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
5538 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
5540 logeventf(ssh, "Initialised %.200s server->client encryption",
5541 ssh->sccipher->text_name);
5542 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
5543 ssh->scmac->text_name);
5544 if (ssh->sccomp->text_name)
5545 logeventf(ssh, "Initialised %s decompression",
5546 ssh->sccomp->text_name);
5549 * Free key exchange data.
5553 if (ssh->kex == &ssh_diffiehellman_gex) {
5559 * Key exchange is over. Loop straight back round if we have a
5560 * deferred rekey reason.
5562 if (ssh->deferred_rekey_reason) {
5563 logevent(ssh->deferred_rekey_reason);
5565 ssh->deferred_rekey_reason = NULL;
5566 goto begin_key_exchange;
5570 * Otherwise, schedule a timer for our next rekey.
5572 ssh->kex_in_progress = FALSE;
5573 ssh->last_rekey = GETTICKCOUNT();
5574 if (ssh->cfg.ssh_rekey_time != 0)
5575 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5579 * If this is the first key exchange phase, we must pass the
5580 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
5581 * wants to see it but because it will need time to initialise
5582 * itself before it sees an actual packet. In subsequent key
5583 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
5584 * it would only confuse the layer above.
5586 if (s->activated_authconn) {
5589 s->activated_authconn = TRUE;
5592 * Now we're encrypting. Begin returning 1 to the protocol main
5593 * function so that other things can run on top of the
5594 * transport. If we ever see a KEXINIT, we must go back to the
5597 * We _also_ go back to the start if we see pktin==NULL and
5598 * inlen==-1, because this is a special signal meaning
5599 * `initiate client-driven rekey', and `in' contains a message
5600 * giving the reason for the rekey.
5602 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
5603 (!pktin && inlen == -1))) {
5608 logevent("Server initiated key re-exchange");
5611 * Special case: if the server bug is set that doesn't
5612 * allow rekeying, we give a different log message and
5613 * continue waiting. (If such a server _initiates_ a rekey,
5614 * we process it anyway!)
5616 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
5617 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
5619 /* Reset the counters, so that at least this message doesn't
5620 * hit the event log _too_ often. */
5621 ssh->outgoing_data_size = 0;
5622 ssh->incoming_data_size = 0;
5623 if (ssh->cfg.ssh_rekey_time != 0) {
5625 schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5628 goto wait_for_rekey; /* this is utterly horrid */
5630 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
5633 goto begin_key_exchange;
5639 * Add data to an SSH2 channel output buffer.
5641 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
5644 bufchain_add(&c->v.v2.outbuffer, buf, len);
5648 * Attempt to send data on an SSH2 channel.
5650 static int ssh2_try_send(struct ssh_channel *c)
5653 struct Packet *pktout;
5655 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
5658 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
5659 if ((unsigned)len > c->v.v2.remwindow)
5660 len = c->v.v2.remwindow;
5661 if ((unsigned)len > c->v.v2.remmaxpkt)
5662 len = c->v.v2.remmaxpkt;
5663 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
5664 ssh2_pkt_adduint32(pktout, c->remoteid);
5665 dont_log_data(ssh, pktout, PKTLOG_OMIT);
5666 ssh2_pkt_addstring_start(pktout);
5667 ssh2_pkt_addstring_data(pktout, data, len);
5668 end_log_omission(ssh, pktout);
5669 ssh2_pkt_send(ssh, pktout);
5670 bufchain_consume(&c->v.v2.outbuffer, len);
5671 c->v.v2.remwindow -= len;
5675 * After having sent as much data as we can, return the amount
5678 return bufchain_size(&c->v.v2.outbuffer);
5682 * Potentially enlarge the window on an SSH2 channel.
5684 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
5689 * Never send WINDOW_ADJUST for a channel that the remote side
5690 * already thinks it's closed; there's no point, since it won't
5691 * be sending any more data anyway.
5697 * Only send a WINDOW_ADJUST if there's significantly more window
5698 * available than the other end thinks there is. This saves us
5699 * sending a WINDOW_ADJUST for every character in a shell session.
5701 * "Significant" is arbitrarily defined as half the window size.
5703 if (newwin > c->v.v2.locwindow * 2) {
5704 struct Packet *pktout;
5706 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5707 ssh2_pkt_adduint32(pktout, c->remoteid);
5708 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
5709 ssh2_pkt_send(ssh, pktout);
5710 c->v.v2.locwindow = newwin;
5714 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
5716 unsigned i = ssh_pkt_getuint32(pktin);
5717 struct ssh_channel *c;
5718 c = find234(ssh->channels, &i, ssh_channelfind);
5719 if (c && !c->closes)
5720 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
5723 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
5727 unsigned i = ssh_pkt_getuint32(pktin);
5728 struct ssh_channel *c;
5729 c = find234(ssh->channels, &i, ssh_channelfind);
5731 return; /* nonexistent channel */
5732 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5733 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
5734 return; /* extended but not stderr */
5735 ssh_pkt_getstring(pktin, &data, &length);
5738 c->v.v2.locwindow -= length;
5740 case CHAN_MAINSESSION:
5742 from_backend(ssh->frontend, pktin->type ==
5743 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5747 bufsize = x11_send(c->u.x11.s, data, length);
5750 bufsize = pfd_send(c->u.pfd.s, data, length);
5753 while (length > 0) {
5754 if (c->u.a.lensofar < 4) {
5755 unsigned int l = min(4 - c->u.a.lensofar, length);
5756 memcpy(c->u.a.msglen + c->u.a.lensofar,
5760 c->u.a.lensofar += l;
5762 if (c->u.a.lensofar == 4) {
5764 4 + GET_32BIT(c->u.a.msglen);
5765 c->u.a.message = snewn(c->u.a.totallen,
5767 memcpy(c->u.a.message, c->u.a.msglen, 4);
5769 if (c->u.a.lensofar >= 4 && length > 0) {
5771 min(c->u.a.totallen - c->u.a.lensofar,
5773 memcpy(c->u.a.message + c->u.a.lensofar,
5777 c->u.a.lensofar += l;
5779 if (c->u.a.lensofar == c->u.a.totallen) {
5782 if (agent_query(c->u.a.message,
5785 ssh_agentf_callback, c))
5786 ssh_agentf_callback(c, reply, replylen);
5787 sfree(c->u.a.message);
5788 c->u.a.lensofar = 0;
5795 * If we are not buffering too much data,
5796 * enlarge the window again at the remote side.
5798 if (bufsize < OUR_V2_WINSIZE)
5799 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5803 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
5805 unsigned i = ssh_pkt_getuint32(pktin);
5806 struct ssh_channel *c;
5808 c = find234(ssh->channels, &i, ssh_channelfind);
5810 return; /* nonexistent channel */
5812 if (c->type == CHAN_X11) {
5814 * Remote EOF on an X11 channel means we should
5815 * wrap up and close the channel ourselves.
5817 x11_close(c->u.x11.s);
5819 } else if (c->type == CHAN_AGENT) {
5821 } else if (c->type == CHAN_SOCKDATA) {
5822 pfd_close(c->u.pfd.s);
5827 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
5829 unsigned i = ssh_pkt_getuint32(pktin);
5830 struct ssh_channel *c;
5831 struct Packet *pktout;
5833 c = find234(ssh->channels, &i, ssh_channelfind);
5834 if (!c || c->halfopen) {
5835 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5836 c ? "half-open" : "nonexistent", i));
5839 /* Do pre-close processing on the channel. */
5841 case CHAN_MAINSESSION:
5842 ssh->mainchan = NULL;
5843 update_specials_menu(ssh->frontend);
5846 if (c->u.x11.s != NULL)
5847 x11_close(c->u.x11.s);
5854 if (c->u.pfd.s != NULL)
5855 pfd_close(c->u.pfd.s);
5859 if (c->closes == 0) {
5860 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5861 ssh2_pkt_adduint32(pktout, c->remoteid);
5862 ssh2_pkt_send(ssh, pktout);
5864 del234(ssh->channels, c);
5865 bufchain_clear(&c->v.v2.outbuffer);
5869 * See if that was the last channel left open.
5870 * (This is only our termination condition if we're
5871 * not running in -N mode.)
5873 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
5874 logevent("All channels closed. Disconnecting");
5877 * We used to send SSH_MSG_DISCONNECT here,
5878 * because I'd believed that _every_ conforming
5879 * SSH2 connection had to end with a disconnect
5880 * being sent by at least one side; apparently
5881 * I was wrong and it's perfectly OK to
5882 * unceremoniously slam the connection shut
5883 * when you're done, and indeed OpenSSH feels
5884 * this is more polite than sending a
5885 * DISCONNECT. So now we don't.
5887 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5888 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
5889 ssh2_pkt_addstring(s->pktout, "All open channels closed");
5890 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
5891 ssh2_pkt_send_noqueue(ssh, s->pktout);
5893 ssh->close_expected = TRUE;
5894 ssh_closing((Plug)ssh, NULL, 0, 0);
5898 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5900 unsigned i = ssh_pkt_getuint32(pktin);
5901 struct ssh_channel *c;
5902 struct Packet *pktout;
5904 c = find234(ssh->channels, &i, ssh_channelfind);
5906 return; /* nonexistent channel */
5907 if (c->type != CHAN_SOCKDATA_DORMANT)
5908 return; /* dunno why they're confirming this */
5909 c->remoteid = ssh_pkt_getuint32(pktin);
5910 c->halfopen = FALSE;
5911 c->type = CHAN_SOCKDATA;
5912 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
5913 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
5915 pfd_confirm(c->u.pfd.s);
5918 * We have a pending close on this channel,
5919 * which we decided on before the server acked
5920 * the channel open. So now we know the
5921 * remoteid, we can close it again.
5923 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5924 ssh2_pkt_adduint32(pktout, c->remoteid);
5925 ssh2_pkt_send(ssh, pktout);
5929 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5931 static const char *const reasons[] = {
5932 "<unknown reason code>",
5933 "Administratively prohibited",
5935 "Unknown channel type",
5936 "Resource shortage",
5938 unsigned i = ssh_pkt_getuint32(pktin);
5939 unsigned reason_code;
5940 char *reason_string;
5942 struct ssh_channel *c;
5943 c = find234(ssh->channels, &i, ssh_channelfind);
5945 return; /* nonexistent channel */
5946 if (c->type != CHAN_SOCKDATA_DORMANT)
5947 return; /* dunno why they're failing this */
5949 reason_code = ssh_pkt_getuint32(pktin);
5950 if (reason_code >= lenof(reasons))
5951 reason_code = 0; /* ensure reasons[reason_code] in range */
5952 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
5953 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
5954 reasons[reason_code], reason_length, reason_string);
5956 pfd_close(c->u.pfd.s);
5958 del234(ssh->channels, c);
5962 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
5966 int typelen, want_reply;
5967 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
5968 struct ssh_channel *c;
5969 struct Packet *pktout;
5971 localid = ssh_pkt_getuint32(pktin);
5972 ssh_pkt_getstring(pktin, &type, &typelen);
5973 want_reply = ssh2_pkt_getbool(pktin);
5976 * First, check that the channel exists. Otherwise,
5977 * we can instantly disconnect with a rude message.
5979 c = find234(ssh->channels, &localid, ssh_channelfind);
5982 sprintf(buf, "Received channel request for nonexistent"
5983 " channel %d", localid);
5985 pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5986 ssh2_pkt_adduint32(pktout, SSH2_DISCONNECT_BY_APPLICATION);
5987 ssh2_pkt_addstring(pktout, buf);
5988 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5989 ssh2_pkt_send_noqueue(ssh, pktout);
5990 connection_fatal(ssh->frontend, "%s", buf);
5991 ssh->close_expected = TRUE;
5992 ssh_closing((Plug)ssh, NULL, 0, 0);
5997 * Having got the channel number, we now look at
5998 * the request type string to see if it's something
6001 if (c == ssh->mainchan) {
6003 * We recognise "exit-status" and "exit-signal" on
6004 * the primary channel.
6006 if (typelen == 11 &&
6007 !memcmp(type, "exit-status", 11)) {
6009 ssh->exitcode = ssh_pkt_getuint32(pktin);
6010 logeventf(ssh, "Server sent command exit status %d",
6012 reply = SSH2_MSG_CHANNEL_SUCCESS;
6014 } else if (typelen == 11 &&
6015 !memcmp(type, "exit-signal", 11)) {
6017 int is_plausible = TRUE, is_int = FALSE;
6018 char *fmt_sig = "", *fmt_msg = "";
6020 int msglen = 0, core = FALSE;
6021 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
6022 * provide an `int' for the signal, despite its
6023 * having been a `string' in the drafts since at
6024 * least 2001. (Fixed in session.c 1.147.) Try to
6025 * infer which we can safely parse it as. */
6027 unsigned char *p = pktin->body +
6029 long len = pktin->length - pktin->savedpos;
6030 unsigned long num = GET_32BIT(p); /* what is it? */
6031 /* If it's 0, it hardly matters; assume string */
6035 int maybe_int = FALSE, maybe_str = FALSE;
6036 #define CHECK_HYPOTHESIS(offset, result) \
6039 if (q >= 0 && q+4 <= len) { \
6040 q = q + 4 + GET_32BIT(p+q); \
6041 if (q >= 0 && q+4 <= len && \
6042 ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
6046 CHECK_HYPOTHESIS(4+1, maybe_int);
6047 CHECK_HYPOTHESIS(4+num+1, maybe_str);
6048 #undef CHECK_HYPOTHESIS
6049 if (maybe_int && !maybe_str)
6051 else if (!maybe_int && maybe_str)
6054 /* Crikey. Either or neither. Panic. */
6055 is_plausible = FALSE;
6060 /* Old non-standard OpenSSH. */
6061 int signum = ssh_pkt_getuint32(pktin);
6062 fmt_sig = dupprintf(" %d", signum);
6064 /* As per the drafts. */
6067 ssh_pkt_getstring(pktin, &sig, &siglen);
6068 /* Signal name isn't supposed to be blank, but
6069 * let's cope gracefully if it is. */
6071 fmt_sig = dupprintf(" \"%.*s\"",
6075 core = ssh2_pkt_getbool(pktin);
6076 ssh_pkt_getstring(pktin, &msg, &msglen);
6078 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
6080 /* ignore lang tag */
6081 } /* else don't attempt to parse */
6082 logeventf(ssh, "Server exited on signal%s%s%s",
6083 fmt_sig, core ? " (core dumped)" : "",
6085 if (*fmt_sig) sfree(fmt_sig);
6086 if (*fmt_msg) sfree(fmt_msg);
6087 reply = SSH2_MSG_CHANNEL_SUCCESS;
6092 * This is a channel request we don't know
6093 * about, so we now either ignore the request
6094 * or respond with CHANNEL_FAILURE, depending
6097 reply = SSH2_MSG_CHANNEL_FAILURE;
6100 pktout = ssh2_pkt_init(reply);
6101 ssh2_pkt_adduint32(pktout, c->remoteid);
6102 ssh2_pkt_send(ssh, pktout);
6106 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
6109 int typelen, want_reply;
6110 struct Packet *pktout;
6112 ssh_pkt_getstring(pktin, &type, &typelen);
6113 want_reply = ssh2_pkt_getbool(pktin);
6116 * We currently don't support any global requests
6117 * at all, so we either ignore the request or
6118 * respond with REQUEST_FAILURE, depending on
6122 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
6123 ssh2_pkt_send(ssh, pktout);
6127 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
6135 struct ssh_channel *c;
6136 unsigned remid, winsize, pktsize;
6137 struct Packet *pktout;
6139 ssh_pkt_getstring(pktin, &type, &typelen);
6140 c = snew(struct ssh_channel);
6143 remid = ssh_pkt_getuint32(pktin);
6144 winsize = ssh_pkt_getuint32(pktin);
6145 pktsize = ssh_pkt_getuint32(pktin);
6147 if (typelen == 3 && !memcmp(type, "x11", 3)) {
6150 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6151 addrstr = snewn(peeraddrlen+1, char);
6152 memcpy(addrstr, peeraddr, peeraddrlen);
6153 addrstr[peeraddrlen] = '\0';
6154 peerport = ssh_pkt_getuint32(pktin);
6156 logeventf(ssh, "Received X11 connect request from %s:%d",
6159 if (!ssh->X11_fwd_enabled)
6160 error = "X11 forwarding is not enabled";
6161 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
6162 ssh->x11auth, addrstr, peerport,
6163 &ssh->cfg) != NULL) {
6164 error = "Unable to open an X11 connection";
6166 logevent("Opening X11 forward connection succeeded");
6171 } else if (typelen == 15 &&
6172 !memcmp(type, "forwarded-tcpip", 15)) {
6173 struct ssh_rportfwd pf, *realpf;
6176 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
6177 pf.sport = ssh_pkt_getuint32(pktin);
6178 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6179 peerport = ssh_pkt_getuint32(pktin);
6180 realpf = find234(ssh->rportfwds, &pf, NULL);
6181 logeventf(ssh, "Received remote port %d open request "
6182 "from %s:%d", pf.sport, peeraddr, peerport);
6183 if (realpf == NULL) {
6184 error = "Remote port is not recognised";
6186 const char *e = pfd_newconnect(&c->u.pfd.s,
6190 realpf->pfrec->addressfamily);
6191 logeventf(ssh, "Attempting to forward remote port to "
6192 "%s:%d", realpf->dhost, realpf->dport);
6194 logeventf(ssh, "Port open failed: %s", e);
6195 error = "Port open failed";
6197 logevent("Forwarded port opened successfully");
6198 c->type = CHAN_SOCKDATA;
6201 } else if (typelen == 22 &&
6202 !memcmp(type, "auth-agent@openssh.com", 3)) {
6203 if (!ssh->agentfwd_enabled)
6204 error = "Agent forwarding is not enabled";
6206 c->type = CHAN_AGENT; /* identify channel type */
6207 c->u.a.lensofar = 0;
6210 error = "Unsupported channel type requested";
6213 c->remoteid = remid;
6214 c->halfopen = FALSE;
6216 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
6217 ssh2_pkt_adduint32(pktout, c->remoteid);
6218 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
6219 ssh2_pkt_addstring(pktout, error);
6220 ssh2_pkt_addstring(pktout, "en"); /* language tag */
6221 ssh2_pkt_send(ssh, pktout);
6222 logeventf(ssh, "Rejected channel open: %s", error);
6225 c->localid = alloc_channel_id(ssh);
6227 c->v.v2.locwindow = OUR_V2_WINSIZE;
6228 c->v.v2.remwindow = winsize;
6229 c->v.v2.remmaxpkt = pktsize;
6230 bufchain_init(&c->v.v2.outbuffer);
6231 add234(ssh->channels, c);
6232 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
6233 ssh2_pkt_adduint32(pktout, c->remoteid);
6234 ssh2_pkt_adduint32(pktout, c->localid);
6235 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
6236 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
6237 ssh2_pkt_send(ssh, pktout);
6242 * Handle the SSH2 userauth and connection layers.
6244 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
6245 struct Packet *pktin)
6247 struct do_ssh2_authconn_state {
6249 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
6251 AUTH_KEYBOARD_INTERACTIVE
6255 AUTH_TYPE_PUBLICKEY,
6256 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
6257 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
6259 AUTH_TYPE_KEYBOARD_INTERACTIVE,
6260 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
6262 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
6263 int tried_pubkey_config, tried_agent;
6264 int kbd_inter_running, kbd_inter_refused;
6266 int num_prompts, curr_prompt, echo;
6271 void *publickey_blob;
6272 int publickey_bloblen;
6273 unsigned char request[5], *response, *p;
6277 char *pkblob, *alg, *commentp;
6278 int pklen, alglen, commentlen;
6279 int siglen, retlen, len;
6280 char *q, *agentreq, *ret;
6282 int num_env, env_left, env_ok;
6283 struct Packet *pktout;
6285 crState(do_ssh2_authconn_state);
6287 crBegin(ssh->do_ssh2_authconn_crstate);
6290 * Request userauth protocol, and await a response to it.
6292 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6293 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
6294 ssh2_pkt_send(ssh, s->pktout);
6295 crWaitUntilV(pktin);
6296 if (pktin->type != SSH2_MSG_SERVICE_ACCEPT) {
6297 bombout(("Server refused user authentication protocol"));
6302 * We repeat this whole loop, including the username prompt,
6303 * until we manage a successful authentication. If the user
6304 * types the wrong _password_, they can be sent back to the
6305 * beginning to try another username, if this is configured on.
6306 * (If they specify a username in the config, they are never
6307 * asked, even if they do give a wrong password.)
6309 * I think this best serves the needs of
6311 * - the people who have no configuration, no keys, and just
6312 * want to try repeated (username,password) pairs until they
6313 * type both correctly
6315 * - people who have keys and configuration but occasionally
6316 * need to fall back to passwords
6318 * - people with a key held in Pageant, who might not have
6319 * logged in to a particular machine before; so they want to
6320 * type a username, and then _either_ their key will be
6321 * accepted, _or_ they will type a password. If they mistype
6322 * the username they will want to be able to get back and
6325 s->username[0] = '\0';
6326 s->got_username = FALSE;
6331 if (s->got_username && !ssh->cfg.change_username) {
6333 * We got a username last time round this loop, and
6334 * with change_username turned off we don't try to get
6337 } else if (!*ssh->cfg.username) {
6338 if (ssh_get_line && !ssh_getline_pw_only) {
6339 if (!ssh_get_line("login as: ",
6340 s->username, sizeof(s->username), FALSE)) {
6342 * get_line failed to get a username.
6345 logevent("No username provided. Abandoning session.");
6346 ssh->close_expected = TRUE;
6347 ssh_closing((Plug)ssh, NULL, 0, 0);
6351 int ret; /* need not be saved across crReturn */
6352 c_write_str(ssh, "login as: ");
6354 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
6356 crWaitUntilV(!pktin);
6357 ret = process_userpass_input(ssh, in, inlen);
6361 c_write_str(ssh, "\r\n");
6363 s->username[strcspn(s->username, "\n\r")] = '\0';
6366 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
6367 s->username[sizeof(s->username)-1] = '\0';
6368 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
6369 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
6370 c_write_str(ssh, stuff);
6374 s->got_username = TRUE;
6377 * Send an authentication request using method "none": (a)
6378 * just in case it succeeds, and (b) so that we know what
6379 * authentication methods we can usefully try next.
6381 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6383 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6384 ssh2_pkt_addstring(s->pktout, s->username);
6385 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
6386 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6387 ssh2_pkt_send(ssh, s->pktout);
6388 s->type = AUTH_TYPE_NONE;
6390 s->we_are_in = FALSE;
6392 s->tried_pubkey_config = FALSE;
6393 s->tried_agent = FALSE;
6394 s->kbd_inter_running = FALSE;
6395 s->kbd_inter_refused = FALSE;
6396 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
6397 if (!filename_is_null(ssh->cfg.keyfile)) {
6399 logeventf(ssh, "Reading private key file \"%.150s\"",
6400 filename_to_str(&ssh->cfg.keyfile));
6401 keytype = key_type(&ssh->cfg.keyfile);
6402 if (keytype == SSH_KEYTYPE_SSH2) {
6404 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
6405 &s->publickey_bloblen, NULL);
6408 logeventf(ssh, "Unable to use this key file (%s)",
6409 key_type_to_str(keytype));
6410 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6412 filename_to_str(&ssh->cfg.keyfile),
6413 key_type_to_str(keytype));
6414 c_write_str(ssh, msgbuf);
6416 s->publickey_blob = NULL;
6419 s->publickey_blob = NULL;
6423 * Wait for the result of the last authentication request.
6426 crWaitUntilV(pktin);
6427 while (pktin->type == SSH2_MSG_USERAUTH_BANNER) {
6431 * Don't show the banner if we're operating in
6432 * non-verbose non-interactive mode. (It's probably
6433 * a script, which means nobody will read the
6434 * banner _anyway_, and moreover the printing of
6435 * the banner will screw up processing on the
6436 * output of (say) plink.)
6438 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
6439 ssh_pkt_getstring(pktin, &banner, &size);
6441 c_write_untrusted(ssh, banner, size);
6443 crWaitUntilV(pktin);
6445 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
6446 logevent("Access granted");
6447 s->we_are_in = TRUE;
6451 if (s->kbd_inter_running &&
6452 pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
6454 * This is either a further set-of-prompts packet
6455 * in keyboard-interactive authentication, or it's
6456 * the same one and we came back here with `gotit'
6457 * set. In the former case, we must reset the
6458 * curr_prompt variable.
6462 } else if (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
6463 /* FIXME: perhaps we should support this? */
6464 bombout(("PASSWD_CHANGEREQ not yet supported"));
6466 } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
6467 bombout(("Strange packet received during authentication: type %d",
6475 * OK, we're now sitting on a USERAUTH_FAILURE message, so
6476 * we can look at the string in it and know what we can
6477 * helpfully try next.
6479 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
6482 ssh_pkt_getstring(pktin, &methods, &methlen);
6483 s->kbd_inter_running = FALSE;
6484 if (!ssh2_pkt_getbool(pktin)) {
6486 * We have received an unequivocal Access
6487 * Denied. This can translate to a variety of
6490 * - if we'd just tried "none" authentication,
6491 * it's not worth printing anything at all
6493 * - if we'd just tried a public key _offer_,
6494 * the message should be "Server refused our
6495 * key" (or no message at all if the key
6496 * came from Pageant)
6498 * - if we'd just tried anything else, the
6499 * message really should be "Access denied".
6501 * Additionally, if we'd just tried password
6502 * authentication, we should break out of this
6503 * whole loop so as to go back to the username
6504 * prompt (iff we're configured to allow
6505 * username change attempts).
6507 if (s->type == AUTH_TYPE_NONE) {
6509 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
6510 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
6511 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
6512 c_write_str(ssh, "Server refused our key\r\n");
6513 logevent("Server refused public key");
6514 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
6515 /* server declined keyboard-interactive; ignore */
6517 c_write_str(ssh, "Access denied\r\n");
6518 logevent("Access denied");
6519 if (s->type == AUTH_TYPE_PASSWORD &&
6520 ssh->cfg.change_username) {
6521 /* XXX perhaps we should allow
6522 * keyboard-interactive to do this too? */
6523 s->we_are_in = FALSE;
6528 c_write_str(ssh, "Further authentication required\r\n");
6529 logevent("Further authentication required");
6533 in_commasep_string("publickey", methods, methlen);
6535 in_commasep_string("password", methods, methlen);
6536 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
6537 in_commasep_string("keyboard-interactive", methods, methlen);
6541 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6545 * Most password/passphrase prompts will be
6546 * non-echoing, so we set this to 0 by default.
6547 * Exception is that some keyboard-interactive prompts
6548 * can be echoing, in which case we'll set this to 1.
6552 if (!s->method && s->can_pubkey &&
6553 agent_exists() && !s->tried_agent) {
6555 * Attempt public-key authentication using Pageant.
6560 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6561 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6563 s->tried_agent = TRUE;
6565 logevent("Pageant is running. Requesting keys.");
6567 /* Request the keys held by the agent. */
6568 PUT_32BIT(s->request, 1);
6569 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
6570 if (!agent_query(s->request, 5, &r, &s->responselen,
6571 ssh_agent_callback, ssh)) {
6575 bombout(("Unexpected data from server while"
6576 " waiting for agent response"));
6579 } while (pktin || inlen > 0);
6580 r = ssh->agent_response;
6581 s->responselen = ssh->agent_response_len;
6583 s->response = (unsigned char *) r;
6584 if (s->response && s->responselen >= 5 &&
6585 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
6586 s->p = s->response + 5;
6587 s->nkeys = GET_32BIT(s->p);
6589 logeventf(ssh, "Pageant has %d SSH2 keys", s->nkeys);
6590 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
6593 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
6594 s->pklen = GET_32BIT(s->p);
6596 if (s->publickey_blob &&
6597 s->pklen == s->publickey_bloblen &&
6598 !memcmp(s->p, s->publickey_blob,
6599 s->publickey_bloblen)) {
6600 logevent("This key matches configured key file");
6601 s->tried_pubkey_config = 1;
6603 s->pkblob = (char *)s->p;
6605 s->alglen = GET_32BIT(s->pkblob);
6606 s->alg = s->pkblob + 4;
6607 s->commentlen = GET_32BIT(s->p);
6609 s->commentp = (char *)s->p;
6610 s->p += s->commentlen;
6611 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6612 ssh2_pkt_addstring(s->pktout, s->username);
6613 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6614 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6615 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6616 ssh2_pkt_addstring_start(s->pktout);
6617 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6618 ssh2_pkt_addstring_start(s->pktout);
6619 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6620 ssh2_pkt_send(ssh, s->pktout);
6622 crWaitUntilV(pktin);
6623 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6624 logevent("Key refused");
6628 if (flags & FLAG_VERBOSE) {
6629 c_write_str(ssh, "Authenticating with "
6631 c_write(ssh, s->commentp, s->commentlen);
6632 c_write_str(ssh, "\" from agent\r\n");
6636 * Server is willing to accept the key.
6637 * Construct a SIGN_REQUEST.
6639 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6640 ssh2_pkt_addstring(s->pktout, s->username);
6641 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6642 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6643 ssh2_pkt_addbool(s->pktout, TRUE);
6644 ssh2_pkt_addstring_start(s->pktout);
6645 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6646 ssh2_pkt_addstring_start(s->pktout);
6647 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6649 s->siglen = s->pktout->length - 5 + 4 + 20;
6650 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6652 s->len = 1; /* message type */
6653 s->len += 4 + s->pklen; /* key blob */
6654 s->len += 4 + s->siglen; /* data to sign */
6655 s->len += 4; /* flags */
6656 s->agentreq = snewn(4 + s->len, char);
6657 PUT_32BIT(s->agentreq, s->len);
6658 s->q = s->agentreq + 4;
6659 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
6660 PUT_32BIT(s->q, s->pklen);
6662 memcpy(s->q, s->pkblob, s->pklen);
6664 PUT_32BIT(s->q, s->siglen);
6666 /* Now the data to be signed... */
6667 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6668 PUT_32BIT(s->q, 20);
6671 memcpy(s->q, ssh->v2_session_id, 20);
6673 memcpy(s->q, s->pktout->data + 5,
6674 s->pktout->length - 5);
6675 s->q += s->pktout->length - 5;
6676 /* And finally the (zero) flags word. */
6678 if (!agent_query(s->agentreq, s->len + 4,
6680 ssh_agent_callback, ssh)) {
6684 bombout(("Unexpected data from server"
6685 " while waiting for agent"
6689 } while (pktin || inlen > 0);
6690 vret = ssh->agent_response;
6691 s->retlen = ssh->agent_response_len;
6696 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
6697 logevent("Sending Pageant's response");
6698 ssh2_add_sigblob(ssh, s->pktout,
6699 s->pkblob, s->pklen,
6701 GET_32BIT(s->ret + 5));
6702 ssh2_pkt_send(ssh, s->pktout);
6707 ("Pageant failed to answer challenge");
6718 if (!s->method && s->can_pubkey && s->publickey_blob
6719 && !s->tried_pubkey_config) {
6720 unsigned char *pub_blob;
6721 char *algorithm, *comment;
6724 s->tried_pubkey_config = TRUE;
6726 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6727 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6730 * Try the public key supplied in the configuration.
6732 * First, offer the public blob to see if the server is
6733 * willing to accept it.
6736 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
6741 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6742 ssh2_pkt_addstring(s->pktout, s->username);
6743 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6744 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6745 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6746 ssh2_pkt_addstring(s->pktout, algorithm);
6747 ssh2_pkt_addstring_start(s->pktout);
6748 ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob,
6750 ssh2_pkt_send(ssh, s->pktout);
6751 logevent("Offered public key");
6753 crWaitUntilV(pktin);
6754 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6756 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
6757 continue; /* key refused; give up on it */
6760 logevent("Offer of public key accepted");
6762 * Actually attempt a serious authentication using
6765 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
6766 sprintf(s->pwprompt,
6767 "Passphrase for key \"%.100s\": ",
6773 if (flags & FLAG_VERBOSE) {
6774 c_write_str(ssh, "Authenticating with public key \"");
6775 c_write_str(ssh, comment);
6776 c_write_str(ssh, "\"\r\n");
6778 s->method = AUTH_PUBLICKEY_FILE;
6782 if (!s->method && s->can_keyb_inter && !s->kbd_inter_refused &&
6783 !s->kbd_inter_running) {
6784 s->method = AUTH_KEYBOARD_INTERACTIVE;
6785 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6787 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6788 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
6790 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6791 ssh2_pkt_addstring(s->pktout, s->username);
6792 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6793 ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); /* method */
6794 ssh2_pkt_addstring(s->pktout, ""); /* lang */
6795 ssh2_pkt_addstring(s->pktout, "");
6796 ssh2_pkt_send(ssh, s->pktout);
6798 crWaitUntilV(pktin);
6799 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
6800 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
6802 logevent("Keyboard-interactive authentication refused");
6803 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
6804 s->kbd_inter_refused = TRUE; /* don't try it again */
6808 s->kbd_inter_running = TRUE;
6812 if (s->kbd_inter_running) {
6813 s->method = AUTH_KEYBOARD_INTERACTIVE;
6814 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6816 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6817 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
6819 if (s->curr_prompt == 0) {
6821 * We've got a fresh USERAUTH_INFO_REQUEST.
6822 * Display header data, and start going through
6825 char *name, *inst, *lang;
6826 int name_len, inst_len, lang_len;
6828 ssh_pkt_getstring(pktin, &name, &name_len);
6829 ssh_pkt_getstring(pktin, &inst, &inst_len);
6830 ssh_pkt_getstring(pktin, &lang, &lang_len);
6832 c_write_untrusted(ssh, name, name_len);
6833 c_write_str(ssh, "\r\n");
6836 c_write_untrusted(ssh, inst, inst_len);
6837 c_write_str(ssh, "\r\n");
6839 s->num_prompts = ssh_pkt_getuint32(pktin);
6843 * If there are prompts remaining in the packet,
6844 * display one and get a response.
6846 if (s->curr_prompt < s->num_prompts) {
6850 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
6851 if (prompt_len > 0) {
6852 static const char trunc[] = "<prompt truncated>: ";
6853 static const int prlen = sizeof(s->pwprompt) -
6855 if (prompt_len > prlen) {
6856 memcpy(s->pwprompt, prompt, prlen);
6857 strcpy(s->pwprompt + prlen, trunc);
6859 memcpy(s->pwprompt, prompt, prompt_len);
6860 s->pwprompt[prompt_len] = '\0';
6864 "<server failed to send prompt>: ");
6866 s->echo = ssh2_pkt_getbool(pktin);
6872 if (!s->method && s->can_passwd) {
6873 s->method = AUTH_PASSWORD;
6874 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6875 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
6876 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
6883 if (!ssh_get_line(s->pwprompt, s->password,
6884 sizeof(s->password), TRUE)) {
6886 * get_line failed to get a password (for
6887 * example because one was supplied on the
6888 * command line which has already failed to
6891 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6892 ssh2_pkt_adduint32(s->pktout,SSH2_DISCONNECT_BY_APPLICATION);
6893 ssh2_pkt_addstring(s->pktout, "No more passwords available"
6895 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
6896 ssh2_pkt_send_noqueue(ssh, s->pktout);
6897 logevent("Unable to authenticate");
6898 connection_fatal(ssh->frontend,
6899 "Unable to authenticate");
6900 ssh->close_expected = TRUE;
6901 ssh_closing((Plug)ssh, NULL, 0, 0);
6905 int ret; /* need not be saved across crReturn */
6906 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
6909 setup_userpass_input(ssh, s->password,
6910 sizeof(s->password), s->echo);
6912 crWaitUntilV(!pktin);
6913 ret = process_userpass_input(ssh, in, inlen);
6917 c_write_str(ssh, "\r\n");
6921 if (s->method == AUTH_PUBLICKEY_FILE) {
6923 * We have our passphrase. Now try the actual authentication.
6925 struct ssh2_userkey *key;
6926 const char *error = NULL;
6928 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
6930 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
6931 if (key == SSH2_WRONG_PASSPHRASE) {
6932 c_write_str(ssh, "Wrong passphrase\r\n");
6933 s->tried_pubkey_config = FALSE;
6935 c_write_str(ssh, "Unable to load private key (");
6936 c_write_str(ssh, error);
6937 c_write_str(ssh, ")\r\n");
6938 s->tried_pubkey_config = TRUE;
6940 /* Send a spurious AUTH_NONE to return to the top. */
6941 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6942 ssh2_pkt_addstring(s->pktout, s->username);
6943 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6944 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6945 ssh2_pkt_send(ssh, s->pktout);
6946 s->type = AUTH_TYPE_NONE;
6948 unsigned char *pkblob, *sigblob, *sigdata;
6949 int pkblob_len, sigblob_len, sigdata_len;
6953 * We have loaded the private key and the server
6954 * has announced that it's willing to accept it.
6955 * Hallelujah. Generate a signature and send it.
6957 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6958 ssh2_pkt_addstring(s->pktout, s->username);
6959 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6960 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6961 ssh2_pkt_addbool(s->pktout, TRUE);
6962 ssh2_pkt_addstring(s->pktout, key->alg->name);
6963 pkblob = key->alg->public_blob(key->data, &pkblob_len);
6964 ssh2_pkt_addstring_start(s->pktout);
6965 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len);
6968 * The data to be signed is:
6972 * followed by everything so far placed in the
6975 sigdata_len = s->pktout->length - 5 + 4 + 20;
6976 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6978 sigdata = snewn(sigdata_len, unsigned char);
6980 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6981 PUT_32BIT(sigdata+p, 20);
6984 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
6985 memcpy(sigdata+p, s->pktout->data + 5,
6986 s->pktout->length - 5);
6987 p += s->pktout->length - 5;
6988 assert(p == sigdata_len);
6989 sigblob = key->alg->sign(key->data, (char *)sigdata,
6990 sigdata_len, &sigblob_len);
6991 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
6992 sigblob, sigblob_len);
6997 ssh2_pkt_send(ssh, s->pktout);
6998 s->type = AUTH_TYPE_PUBLICKEY;
6999 key->alg->freekey(key->data);
7001 } else if (s->method == AUTH_PASSWORD) {
7003 * We pad out the password packet to 256 bytes to make
7004 * it harder for an attacker to find the length of the
7007 * Anyone using a password longer than 256 bytes
7008 * probably doesn't have much to worry about from
7009 * people who find out how long their password is!
7011 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7012 s->pktout->forcepad = 256;
7013 ssh2_pkt_addstring(s->pktout, s->username);
7014 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
7015 ssh2_pkt_addstring(s->pktout, "password");
7016 ssh2_pkt_addbool(s->pktout, FALSE);
7017 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7018 ssh2_pkt_addstring(s->pktout, s->password);
7019 memset(s->password, 0, sizeof(s->password));
7020 end_log_omission(ssh, s->pktout);
7021 ssh2_pkt_send(ssh, s->pktout);
7022 logevent("Sent password");
7023 s->type = AUTH_TYPE_PASSWORD;
7024 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
7025 if (s->curr_prompt == 0) {
7026 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
7027 s->pktout->forcepad = 256;
7028 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
7030 if (s->need_pw) { /* only add pw if we just got one! */
7031 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7032 ssh2_pkt_addstring(s->pktout, s->password);
7033 memset(s->password, 0, sizeof(s->password));
7034 end_log_omission(ssh, s->pktout);
7037 if (s->curr_prompt >= s->num_prompts) {
7038 ssh2_pkt_send(ssh, s->pktout);
7041 * If there are prompts remaining, we set
7042 * `gotit' so that we won't attempt to get
7043 * another packet. Then we go back round the
7044 * loop and will end up retrieving another
7045 * prompt out of the existing packet. Funky or
7050 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
7052 c_write_str(ssh, "No supported authentication methods"
7053 " left to try!\r\n");
7054 logevent("No supported authentications offered."
7056 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
7057 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
7058 ssh2_pkt_addstring(s->pktout, "No supported authentication"
7059 " methods available");
7060 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
7061 ssh2_pkt_send_noqueue(ssh, s->pktout);
7062 ssh->close_expected = TRUE;
7063 ssh_closing((Plug)ssh, NULL, 0, 0);
7067 } while (!s->we_are_in);
7070 * Now we're authenticated for the connection protocol. The
7071 * connection protocol will automatically have started at this
7072 * point; there's no need to send SERVICE_REQUEST.
7075 ssh->channels = newtree234(ssh_channelcmp);
7078 * Set up handlers for some connection protocol messages, so we
7079 * don't have to handle them repeatedly in this coroutine.
7081 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
7082 ssh2_msg_channel_window_adjust;
7083 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
7084 ssh2_msg_global_request;
7087 * Create the main session channel.
7089 if (!ssh->cfg.ssh_no_shell) {
7090 ssh->mainchan = snew(struct ssh_channel);
7091 ssh->mainchan->ssh = ssh;
7092 ssh->mainchan->localid = alloc_channel_id(ssh);
7093 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7094 ssh2_pkt_addstring(s->pktout, "session");
7095 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
7096 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
7097 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
7098 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
7099 ssh2_pkt_send(ssh, s->pktout);
7100 crWaitUntilV(pktin);
7101 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
7102 bombout(("Server refused to open a session"));
7104 /* FIXME: error data comes back in FAILURE packet */
7106 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
7107 bombout(("Server's channel confirmation cited wrong channel"));
7110 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
7111 ssh->mainchan->halfopen = FALSE;
7112 ssh->mainchan->type = CHAN_MAINSESSION;
7113 ssh->mainchan->closes = 0;
7114 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7115 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7116 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
7117 add234(ssh->channels, ssh->mainchan);
7118 update_specials_menu(ssh->frontend);
7119 logevent("Opened channel for session");
7121 ssh->mainchan = NULL;
7124 * Now we have a channel, make dispatch table entries for
7125 * general channel-based messages.
7127 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
7128 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
7129 ssh2_msg_channel_data;
7130 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
7131 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
7132 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
7133 ssh2_msg_channel_open_confirmation;
7134 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
7135 ssh2_msg_channel_open_failure;
7136 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
7137 ssh2_msg_channel_request;
7138 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
7139 ssh2_msg_channel_open;
7142 * Potentially enable X11 forwarding.
7144 if (ssh->mainchan && ssh->cfg.x11_forward) {
7145 char proto[20], data[64];
7146 logevent("Requesting X11 forwarding");
7147 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
7148 data, sizeof(data), ssh->cfg.x11_auth);
7149 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
7150 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7151 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7152 ssh2_pkt_addstring(s->pktout, "x11-req");
7153 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7154 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
7155 ssh2_pkt_addstring(s->pktout, proto);
7156 ssh2_pkt_addstring(s->pktout, data);
7157 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
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 X11 forwarding request:"
7165 " packet type %d", pktin->type));
7168 logevent("X11 forwarding refused");
7170 logevent("X11 forwarding enabled");
7171 ssh->X11_fwd_enabled = TRUE;
7176 * Enable port forwardings.
7178 ssh_setup_portfwd(ssh, &ssh->cfg);
7181 * Potentially enable agent forwarding.
7183 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
7184 logevent("Requesting OpenSSH-style agent forwarding");
7185 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7186 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7187 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
7188 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7189 ssh2_pkt_send(ssh, s->pktout);
7191 crWaitUntilV(pktin);
7193 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7194 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7195 bombout(("Unexpected response to agent forwarding request:"
7196 " packet type %d", pktin->type));
7199 logevent("Agent forwarding refused");
7201 logevent("Agent forwarding enabled");
7202 ssh->agentfwd_enabled = TRUE;
7207 * Now allocate a pty for the session.
7209 if (ssh->mainchan && !ssh->cfg.nopty) {
7210 /* Unpick the terminal-speed string. */
7211 /* XXX perhaps we should allow no speeds to be sent. */
7212 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
7213 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
7214 /* Build the pty request. */
7215 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7216 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
7217 ssh2_pkt_addstring(s->pktout, "pty-req");
7218 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7219 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
7220 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
7221 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
7222 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
7223 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
7224 ssh2_pkt_addstring_start(s->pktout);
7225 ssh2_pkt_addbyte(s->pktout, 128); /* TTY_OP_ISPEED */
7226 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
7227 ssh2_pkt_addbyte(s->pktout, 129); /* TTY_OP_OSPEED */
7228 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
7229 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
7230 ssh2_pkt_send(ssh, s->pktout);
7231 ssh->state = SSH_STATE_INTERMED;
7233 crWaitUntilV(pktin);
7235 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7236 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7237 bombout(("Unexpected response to pty request:"
7238 " packet type %d", pktin->type));
7241 c_write_str(ssh, "Server refused to allocate pty\r\n");
7242 ssh->editing = ssh->echoing = 1;
7244 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
7245 ssh->ospeed, ssh->ispeed);
7248 ssh->editing = ssh->echoing = 1;
7252 * Send environment variables.
7254 * Simplest thing here is to send all the requests at once, and
7255 * then wait for a whole bunch of successes or failures.
7257 if (ssh->mainchan && *ssh->cfg.environmt) {
7258 char *e = ssh->cfg.environmt;
7259 char *var, *varend, *val;
7265 while (*e && *e != '\t') e++;
7267 if (*e == '\t') e++;
7272 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7273 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7274 ssh2_pkt_addstring(s->pktout, "env");
7275 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7276 ssh2_pkt_addstring_start(s->pktout);
7277 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
7278 ssh2_pkt_addstring(s->pktout, val);
7279 ssh2_pkt_send(ssh, s->pktout);
7284 logeventf(ssh, "Sent %d environment variables", s->num_env);
7287 s->env_left = s->num_env;
7289 while (s->env_left > 0) {
7290 crWaitUntilV(pktin);
7292 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7293 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7294 bombout(("Unexpected response to environment request:"
7295 " packet type %d", pktin->type));
7305 if (s->env_ok == s->num_env) {
7306 logevent("All environment variables successfully set");
7307 } else if (s->env_ok == 0) {
7308 logevent("All environment variables refused");
7309 c_write_str(ssh, "Server refused to set environment variables\r\n");
7311 logeventf(ssh, "%d environment variables refused",
7312 s->num_env - s->env_ok);
7313 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7318 * Start a shell or a remote command. We may have to attempt
7319 * this twice if the config data has provided a second choice
7322 if (ssh->mainchan) while (1) {
7326 if (ssh->fallback_cmd) {
7327 subsys = ssh->cfg.ssh_subsys2;
7328 cmd = ssh->cfg.remote_cmd_ptr2;
7330 subsys = ssh->cfg.ssh_subsys;
7331 cmd = ssh->cfg.remote_cmd_ptr;
7332 if (!cmd) cmd = ssh->cfg.remote_cmd;
7335 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7336 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
7338 ssh2_pkt_addstring(s->pktout, "subsystem");
7339 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7340 ssh2_pkt_addstring(s->pktout, cmd);
7342 ssh2_pkt_addstring(s->pktout, "exec");
7343 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7344 ssh2_pkt_addstring(s->pktout, cmd);
7346 ssh2_pkt_addstring(s->pktout, "shell");
7347 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7349 ssh2_pkt_send(ssh, s->pktout);
7351 crWaitUntilV(pktin);
7353 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7354 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7355 bombout(("Unexpected response to shell/command request:"
7356 " packet type %d", pktin->type));
7360 * We failed to start the command. If this is the
7361 * fallback command, we really are finished; if it's
7362 * not, and if the fallback command exists, try falling
7363 * back to it before complaining.
7365 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
7366 logevent("Primary command failed; attempting fallback");
7367 ssh->fallback_cmd = TRUE;
7370 bombout(("Server refused to start a shell/command"));
7373 logevent("Started a shell/command");
7378 ssh->state = SSH_STATE_SESSION;
7379 if (ssh->size_needed)
7380 ssh_size(ssh, ssh->term_width, ssh->term_height);
7381 if (ssh->eof_needed)
7382 ssh_special(ssh, TS_EOF);
7388 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
7393 s->try_send = FALSE;
7397 * _All_ the connection-layer packets we expect to
7398 * receive are now handled by the dispatch table.
7399 * Anything that reaches here must be bogus.
7402 bombout(("Strange packet received: type %d", pktin->type));
7404 } else if (ssh->mainchan) {
7406 * We have spare data. Add it to the channel buffer.
7408 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
7413 struct ssh_channel *c;
7415 * Try to send data on all channels if we can.
7417 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
7420 continue; /* don't send on closing channels */
7421 bufsize = ssh2_try_send(c);
7424 case CHAN_MAINSESSION:
7425 /* stdin need not receive an unthrottle
7426 * notification since it will be polled */
7429 x11_unthrottle(c->u.x11.s);
7432 /* agent sockets are request/response and need no
7433 * buffer management */
7436 pfd_unthrottle(c->u.pfd.s);
7448 * Handlers for SSH2 messages that might arrive at any moment.
7450 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
7452 /* log reason code in disconnect message */
7454 int nowlen, reason, msglen;
7456 reason = ssh_pkt_getuint32(pktin);
7457 ssh_pkt_getstring(pktin, &msg, &msglen);
7459 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
7460 buf = dupprintf("Received disconnect message (%s)",
7461 ssh2_disconnect_reasons[reason]);
7463 buf = dupprintf("Received disconnect message (unknown"
7464 " type %d)", reason);
7468 buf = dupprintf("Disconnection message text: %n%.*s",
7469 &nowlen, msglen, msg);
7471 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
7473 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
7474 ssh2_disconnect_reasons[reason] : "unknown",
7479 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
7481 /* log the debug message */
7486 /* XXX maybe we should actually take notice of this */
7487 always_display = ssh2_pkt_getbool(pktin);
7488 ssh_pkt_getstring(pktin, &msg, &msglen);
7490 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
7493 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
7495 struct Packet *pktout;
7496 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
7497 ssh2_pkt_adduint32(pktout, pktin->sequence);
7499 * UNIMPLEMENTED messages MUST appear in the same order as the
7500 * messages they respond to. Hence, never queue them.
7502 ssh2_pkt_send_noqueue(ssh, pktout);
7506 * Handle the top-level SSH2 protocol.
7508 static void ssh2_protocol_setup(Ssh ssh)
7513 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
7515 for (i = 0; i < 256; i++)
7516 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
7519 * Any message we actually understand, we set to NULL so that
7520 * the coroutines will get it.
7522 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
7523 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
7524 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
7525 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
7526 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
7527 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
7528 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
7529 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
7530 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
7531 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
7532 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
7533 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
7534 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
7535 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
7536 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7537 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
7538 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
7539 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
7540 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
7541 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
7542 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
7543 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
7544 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
7545 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
7546 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
7547 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
7548 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
7549 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
7550 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
7551 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
7552 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
7553 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
7554 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
7557 * These special message types we install handlers for.
7559 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
7560 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with ssh1 */
7561 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
7564 static void ssh2_timer(void *ctx, long now)
7568 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
7569 now - ssh->next_rekey >= 0) {
7570 do_ssh2_transport(ssh, "timeout", -1, NULL);
7574 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
7575 struct Packet *pktin)
7577 unsigned char *in = (unsigned char *)vin;
7578 if (ssh->state == SSH_STATE_CLOSED)
7582 ssh->incoming_data_size += pktin->encrypted_len;
7583 if (!ssh->kex_in_progress &&
7584 ssh->max_data_size != 0 &&
7585 ssh->incoming_data_size > ssh->max_data_size)
7586 do_ssh2_transport(ssh, "too much data received", -1, NULL);
7589 if (pktin && ssh->packet_dispatch[pktin->type]) {
7590 ssh->packet_dispatch[pktin->type](ssh, pktin);
7594 if (!ssh->protocol_initial_phase_done ||
7595 (pktin && pktin->type >= 20 && pktin->type < 50)) {
7596 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
7597 !ssh->protocol_initial_phase_done) {
7598 ssh->protocol_initial_phase_done = TRUE;
7600 * Allow authconn to initialise itself.
7602 do_ssh2_authconn(ssh, NULL, 0, NULL);
7605 do_ssh2_authconn(ssh, in, inlen, pktin);
7610 * Called to set up the connection.
7612 * Returns an error message, or NULL on success.
7614 static const char *ssh_init(void *frontend_handle, void **backend_handle,
7616 char *host, int port, char **realhost, int nodelay,
7622 ssh = snew(struct ssh_tag);
7623 ssh->cfg = *cfg; /* STRUCTURE COPY */
7624 ssh->version = 0; /* when not ready yet */
7627 ssh->v1_cipher_ctx = NULL;
7628 ssh->crcda_ctx = NULL;
7629 ssh->cscipher = NULL;
7630 ssh->cs_cipher_ctx = NULL;
7631 ssh->sccipher = NULL;
7632 ssh->sc_cipher_ctx = NULL;
7634 ssh->cs_mac_ctx = NULL;
7636 ssh->sc_mac_ctx = NULL;
7638 ssh->cs_comp_ctx = NULL;
7640 ssh->sc_comp_ctx = NULL;
7642 ssh->kex_ctx = NULL;
7643 ssh->hostkey = NULL;
7645 ssh->close_expected = FALSE;
7646 ssh->state = SSH_STATE_PREPACKET;
7647 ssh->size_needed = FALSE;
7648 ssh->eof_needed = FALSE;
7651 ssh->deferred_send_data = NULL;
7652 ssh->deferred_len = 0;
7653 ssh->deferred_size = 0;
7654 ssh->fallback_cmd = 0;
7656 ssh->x11auth = NULL;
7657 ssh->v1_compressing = FALSE;
7658 ssh->v2_outgoing_sequence = 0;
7659 ssh->ssh1_rdpkt_crstate = 0;
7660 ssh->ssh2_rdpkt_crstate = 0;
7661 ssh->do_ssh_init_crstate = 0;
7662 ssh->ssh_gotdata_crstate = 0;
7663 ssh->do_ssh1_connection_crstate = 0;
7664 ssh->do_ssh1_login_crstate = 0;
7665 ssh->do_ssh2_transport_crstate = 0;
7666 ssh->do_ssh2_authconn_crstate = 0;
7667 ssh->do_ssh_init_state = NULL;
7668 ssh->do_ssh1_login_state = NULL;
7669 ssh->do_ssh2_transport_state = NULL;
7670 ssh->do_ssh2_authconn_state = NULL;
7671 ssh->mainchan = NULL;
7672 ssh->throttled_all = 0;
7673 ssh->v1_stdout_throttling = 0;
7675 ssh->queuelen = ssh->queuesize = 0;
7676 ssh->queueing = FALSE;
7677 ssh->qhead = ssh->qtail = NULL;
7678 ssh->deferred_rekey_reason = NULL;
7679 bufchain_init(&ssh->queued_incoming_data);
7680 ssh->frozen = FALSE;
7682 *backend_handle = ssh;
7685 if (crypto_startup() == 0)
7686 return "Microsoft high encryption pack not installed!";
7689 ssh->frontend = frontend_handle;
7690 ssh->term_width = ssh->cfg.width;
7691 ssh->term_height = ssh->cfg.height;
7693 ssh->channels = NULL;
7694 ssh->rportfwds = NULL;
7695 ssh->portfwds = NULL;
7700 ssh->v1_throttle_count = 0;
7701 ssh->overall_bufsize = 0;
7702 ssh->fallback_cmd = 0;
7704 ssh->protocol = NULL;
7706 ssh->protocol_initial_phase_done = FALSE;
7710 ssh->incoming_data_size = ssh->outgoing_data_size =
7711 ssh->deferred_data_size = 0L;
7712 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
7713 ssh->kex_in_progress = FALSE;
7715 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
7724 static void ssh_free(void *handle)
7726 Ssh ssh = (Ssh) handle;
7727 struct ssh_channel *c;
7728 struct ssh_rportfwd *pf;
7730 if (ssh->v1_cipher_ctx)
7731 ssh->cipher->free_context(ssh->v1_cipher_ctx);
7732 if (ssh->cs_cipher_ctx)
7733 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7734 if (ssh->sc_cipher_ctx)
7735 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7736 if (ssh->cs_mac_ctx)
7737 ssh->csmac->free_context(ssh->cs_mac_ctx);
7738 if (ssh->sc_mac_ctx)
7739 ssh->scmac->free_context(ssh->sc_mac_ctx);
7740 if (ssh->cs_comp_ctx) {
7742 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7744 zlib_compress_cleanup(ssh->cs_comp_ctx);
7746 if (ssh->sc_comp_ctx) {
7748 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7750 zlib_decompress_cleanup(ssh->sc_comp_ctx);
7753 dh_cleanup(ssh->kex_ctx);
7754 sfree(ssh->savedhost);
7756 while (ssh->queuelen-- > 0)
7757 ssh_free_packet(ssh->queue[ssh->queuelen]);
7760 while (ssh->qhead) {
7761 struct queued_handler *qh = ssh->qhead;
7762 ssh->qhead = qh->next;
7765 ssh->qhead = ssh->qtail = NULL;
7767 if (ssh->channels) {
7768 while ((c = delpos234(ssh->channels, 0)) != NULL) {
7771 if (c->u.x11.s != NULL)
7772 x11_close(c->u.x11.s);
7775 if (c->u.pfd.s != NULL)
7776 pfd_close(c->u.pfd.s);
7781 freetree234(ssh->channels);
7782 ssh->channels = NULL;
7785 if (ssh->rportfwds) {
7786 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
7788 freetree234(ssh->rportfwds);
7789 ssh->rportfwds = NULL;
7791 sfree(ssh->deferred_send_data);
7793 x11_free_auth(ssh->x11auth);
7794 sfree(ssh->do_ssh_init_state);
7795 sfree(ssh->do_ssh1_login_state);
7796 sfree(ssh->do_ssh2_transport_state);
7797 sfree(ssh->do_ssh2_authconn_state);
7798 if (ssh->crcda_ctx) {
7799 crcda_free_context(ssh->crcda_ctx);
7800 ssh->crcda_ctx = NULL;
7803 ssh_do_close(ssh, TRUE);
7804 expire_timer_context(ssh);
7806 pinger_free(ssh->pinger);
7807 bufchain_clear(&ssh->queued_incoming_data);
7814 * Reconfigure the SSH backend.
7816 static void ssh_reconfig(void *handle, Config *cfg)
7818 Ssh ssh = (Ssh) handle;
7819 char *rekeying = NULL, rekey_mandatory = FALSE;
7820 unsigned long old_max_data_size;
7822 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
7823 ssh_setup_portfwd(ssh, cfg);
7825 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
7826 cfg->ssh_rekey_time != 0) {
7827 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
7828 long now = GETTICKCOUNT();
7830 if (new_next - now < 0) {
7831 rekeying = "timeout shortened";
7833 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
7837 old_max_data_size = ssh->max_data_size;
7838 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
7839 if (old_max_data_size != ssh->max_data_size &&
7840 ssh->max_data_size != 0) {
7841 if (ssh->outgoing_data_size > ssh->max_data_size ||
7842 ssh->incoming_data_size > ssh->max_data_size)
7843 rekeying = "data limit lowered";
7846 if (ssh->cfg.compression != cfg->compression) {
7847 rekeying = "compression setting changed";
7848 rekey_mandatory = TRUE;
7851 if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
7852 memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
7853 sizeof(ssh->cfg.ssh_cipherlist))) {
7854 rekeying = "cipher settings changed";
7855 rekey_mandatory = TRUE;
7858 ssh->cfg = *cfg; /* STRUCTURE COPY */
7861 if (!ssh->kex_in_progress) {
7862 do_ssh2_transport(ssh, rekeying, -1, NULL);
7863 } else if (rekey_mandatory) {
7864 ssh->deferred_rekey_reason = rekeying;
7870 * Called to send data down the Telnet connection.
7872 static int ssh_send(void *handle, char *buf, int len)
7874 Ssh ssh = (Ssh) handle;
7876 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
7879 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
7881 return ssh_sendbuffer(ssh);
7885 * Called to query the current amount of buffered stdin data.
7887 static int ssh_sendbuffer(void *handle)
7889 Ssh ssh = (Ssh) handle;
7892 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
7896 * If the SSH socket itself has backed up, add the total backup
7897 * size on that to any individual buffer on the stdin channel.
7900 if (ssh->throttled_all)
7901 override_value = ssh->overall_bufsize;
7903 if (ssh->version == 1) {
7904 return override_value;
7905 } else if (ssh->version == 2) {
7906 if (!ssh->mainchan || ssh->mainchan->closes > 0)
7907 return override_value;
7909 return (override_value +
7910 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
7917 * Called to set the size of the window from SSH's POV.
7919 static void ssh_size(void *handle, int width, int height)
7921 Ssh ssh = (Ssh) handle;
7922 struct Packet *pktout;
7924 ssh->term_width = width;
7925 ssh->term_height = height;
7927 switch (ssh->state) {
7928 case SSH_STATE_BEFORE_SIZE:
7929 case SSH_STATE_PREPACKET:
7930 case SSH_STATE_CLOSED:
7931 break; /* do nothing */
7932 case SSH_STATE_INTERMED:
7933 ssh->size_needed = TRUE; /* buffer for later */
7935 case SSH_STATE_SESSION:
7936 if (!ssh->cfg.nopty) {
7937 if (ssh->version == 1) {
7938 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
7939 PKT_INT, ssh->term_height,
7940 PKT_INT, ssh->term_width,
7941 PKT_INT, 0, PKT_INT, 0, PKT_END);
7942 } else if (ssh->mainchan) {
7943 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7944 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7945 ssh2_pkt_addstring(pktout, "window-change");
7946 ssh2_pkt_addbool(pktout, 0);
7947 ssh2_pkt_adduint32(pktout, ssh->term_width);
7948 ssh2_pkt_adduint32(pktout, ssh->term_height);
7949 ssh2_pkt_adduint32(pktout, 0);
7950 ssh2_pkt_adduint32(pktout, 0);
7951 ssh2_pkt_send(ssh, pktout);
7959 * Return a list of the special codes that make sense in this
7962 static const struct telnet_special *ssh_get_specials(void *handle)
7964 static const struct telnet_special ssh1_ignore_special[] = {
7965 {"IGNORE message", TS_NOP}
7967 static const struct telnet_special ssh2_transport_specials[] = {
7968 {"IGNORE message", TS_NOP},
7969 {"Repeat key exchange", TS_REKEY},
7971 static const struct telnet_special ssh2_session_specials[] = {
7974 /* These are the signal names defined by draft-ietf-secsh-connect-23.
7975 * They include all the ISO C signals, but are a subset of the POSIX
7976 * required signals. */
7977 {"SIGINT (Interrupt)", TS_SIGINT},
7978 {"SIGTERM (Terminate)", TS_SIGTERM},
7979 {"SIGKILL (Kill)", TS_SIGKILL},
7980 {"SIGQUIT (Quit)", TS_SIGQUIT},
7981 {"SIGHUP (Hangup)", TS_SIGHUP},
7982 {"More signals", TS_SUBMENU},
7983 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
7984 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
7985 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
7986 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
7989 static const struct telnet_special specials_end[] = {
7992 /* XXX review this length for any changes: */
7993 static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
7994 lenof(ssh2_session_specials) +
7995 lenof(specials_end)];
7996 Ssh ssh = (Ssh) handle;
7998 #define ADD_SPECIALS(name) \
8000 assert((i + lenof(name)) <= lenof(ssh_specials)); \
8001 memcpy(&ssh_specials[i], name, sizeof name); \
8005 if (ssh->version == 1) {
8006 /* Don't bother offering IGNORE if we've decided the remote
8007 * won't cope with it, since we wouldn't bother sending it if
8009 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
8010 ADD_SPECIALS(ssh1_ignore_special);
8011 } else if (ssh->version == 2) {
8012 ADD_SPECIALS(ssh2_transport_specials);
8014 ADD_SPECIALS(ssh2_session_specials);
8015 } /* else we're not ready yet */
8018 ADD_SPECIALS(specials_end);
8019 return ssh_specials;
8027 * Send Telnet special codes. TS_EOF is useful for `plink', so you
8028 * can send an EOF and collect resulting output (e.g. `plink
8031 static void ssh_special(void *handle, Telnet_Special code)
8033 Ssh ssh = (Ssh) handle;
8034 struct Packet *pktout;
8036 if (code == TS_EOF) {
8037 if (ssh->state != SSH_STATE_SESSION) {
8039 * Buffer the EOF in case we are pre-SESSION, so we can
8040 * send it as soon as we reach SESSION.
8043 ssh->eof_needed = TRUE;
8046 if (ssh->version == 1) {
8047 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
8048 } else if (ssh->mainchan) {
8049 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
8050 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8051 ssh2_pkt_send(ssh, pktout);
8053 logevent("Sent EOF message");
8054 } else if (code == TS_PING || code == TS_NOP) {
8055 if (ssh->state == SSH_STATE_CLOSED
8056 || ssh->state == SSH_STATE_PREPACKET) return;
8057 if (ssh->version == 1) {
8058 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
8059 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
8061 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
8062 ssh2_pkt_addstring_start(pktout);
8063 ssh2_pkt_send_noqueue(ssh, pktout);
8065 } else if (code == TS_REKEY) {
8066 if (!ssh->kex_in_progress && ssh->version == 2) {
8067 do_ssh2_transport(ssh, "at user request", -1, NULL);
8069 } else if (code == TS_BRK) {
8070 if (ssh->state == SSH_STATE_CLOSED
8071 || ssh->state == SSH_STATE_PREPACKET) return;
8072 if (ssh->version == 1) {
8073 logevent("Unable to send BREAK signal in SSH1");
8074 } else if (ssh->mainchan) {
8075 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8076 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8077 ssh2_pkt_addstring(pktout, "break");
8078 ssh2_pkt_addbool(pktout, 0);
8079 ssh2_pkt_adduint32(pktout, 0); /* default break length */
8080 ssh2_pkt_send(ssh, pktout);
8083 /* Is is a POSIX signal? */
8084 char *signame = NULL;
8085 if (code == TS_SIGABRT) signame = "ABRT";
8086 if (code == TS_SIGALRM) signame = "ALRM";
8087 if (code == TS_SIGFPE) signame = "FPE";
8088 if (code == TS_SIGHUP) signame = "HUP";
8089 if (code == TS_SIGILL) signame = "ILL";
8090 if (code == TS_SIGINT) signame = "INT";
8091 if (code == TS_SIGKILL) signame = "KILL";
8092 if (code == TS_SIGPIPE) signame = "PIPE";
8093 if (code == TS_SIGQUIT) signame = "QUIT";
8094 if (code == TS_SIGSEGV) signame = "SEGV";
8095 if (code == TS_SIGTERM) signame = "TERM";
8096 if (code == TS_SIGUSR1) signame = "USR1";
8097 if (code == TS_SIGUSR2) signame = "USR2";
8098 /* The SSH-2 protocol does in principle support arbitrary named
8099 * signals, including signame@domain, but we don't support those. */
8101 /* It's a signal. */
8102 if (ssh->version == 2 && ssh->mainchan) {
8103 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8104 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8105 ssh2_pkt_addstring(pktout, "signal");
8106 ssh2_pkt_addbool(pktout, 0);
8107 ssh2_pkt_addstring(pktout, signame);
8108 ssh2_pkt_send(ssh, pktout);
8109 logeventf(ssh, "Sent signal SIG%s", signame);
8112 /* Never heard of it. Do nothing */
8117 void *new_sock_channel(void *handle, Socket s)
8119 Ssh ssh = (Ssh) handle;
8120 struct ssh_channel *c;
8121 c = snew(struct ssh_channel);
8126 c->localid = alloc_channel_id(ssh);
8128 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
8130 bufchain_init(&c->v.v2.outbuffer);
8131 add234(ssh->channels, c);
8137 * This is called when stdout/stderr (the entity to which
8138 * from_backend sends data) manages to clear some backlog.
8140 static void ssh_unthrottle(void *handle, int bufsize)
8142 Ssh ssh = (Ssh) handle;
8143 if (ssh->version == 1) {
8144 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
8145 ssh->v1_stdout_throttling = 0;
8146 ssh1_throttle(ssh, -1);
8149 if (ssh->mainchan && ssh->mainchan->closes == 0)
8150 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
8154 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
8156 struct ssh_channel *c = (struct ssh_channel *)channel;
8158 struct Packet *pktout;
8160 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
8162 if (ssh->version == 1) {
8163 send_packet(ssh, SSH1_MSG_PORT_OPEN,
8164 PKT_INT, c->localid,
8167 /* PKT_STR, <org:orgport>, */
8170 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
8171 ssh2_pkt_addstring(pktout, "direct-tcpip");
8172 ssh2_pkt_adduint32(pktout, c->localid);
8173 c->v.v2.locwindow = OUR_V2_WINSIZE;
8174 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
8175 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8176 ssh2_pkt_addstring(pktout, hostname);
8177 ssh2_pkt_adduint32(pktout, port);
8179 * We make up values for the originator data; partly it's
8180 * too much hassle to keep track, and partly I'm not
8181 * convinced the server should be told details like that
8182 * about my local network configuration.
8184 ssh2_pkt_addstring(pktout, "client-side-connection");
8185 ssh2_pkt_adduint32(pktout, 0);
8186 ssh2_pkt_send(ssh, pktout);
8190 static Socket ssh_socket(void *handle)
8192 Ssh ssh = (Ssh) handle;
8196 static int ssh_sendok(void *handle)
8198 Ssh ssh = (Ssh) handle;
8199 return ssh->send_ok;
8202 static int ssh_ldisc(void *handle, int option)
8204 Ssh ssh = (Ssh) handle;
8205 if (option == LD_ECHO)
8206 return ssh->echoing;
8207 if (option == LD_EDIT)
8208 return ssh->editing;
8212 static void ssh_provide_ldisc(void *handle, void *ldisc)
8214 Ssh ssh = (Ssh) handle;
8218 static void ssh_provide_logctx(void *handle, void *logctx)
8220 Ssh ssh = (Ssh) handle;
8221 ssh->logctx = logctx;
8224 static int ssh_return_exitcode(void *handle)
8226 Ssh ssh = (Ssh) handle;
8230 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
8234 * cfg_info for SSH is the currently running version of the
8235 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
8237 static int ssh_cfg_info(void *handle)
8239 Ssh ssh = (Ssh) handle;
8240 return ssh->version;
8244 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
8245 * that fails. This variable is the means by which scp.c can reach
8246 * into the SSH code and find out which one it got.
8248 extern int ssh_fallback_cmd(void *handle)
8250 Ssh ssh = (Ssh) handle;
8251 return ssh->fallback_cmd;
8254 Backend ssh_backend = {
8264 ssh_return_exitcode,