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)
2386 sk_set_frozen(ssh->s, frozen);
2387 ssh->frozen = frozen;
2390 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2392 crBegin(ssh->ssh_gotdata_crstate);
2395 * To begin with, feed the characters one by one to the
2396 * protocol initialisation / selection function do_ssh_init().
2397 * When that returns 0, we're done with the initial greeting
2398 * exchange and can move on to packet discipline.
2401 int ret; /* need not be kept across crReturn */
2403 crReturnV; /* more data please */
2404 ret = do_ssh_init(ssh, *data);
2412 * We emerge from that loop when the initial negotiation is
2413 * over and we have selected an s_rdpkt function. Now pass
2414 * everything to s_rdpkt, and then pass the resulting packets
2415 * to the proper protocol handler.
2421 * Process queued data if there is any.
2423 ssh_process_queued_incoming_data(ssh);
2426 while (datalen > 0) {
2428 ssh_queue_incoming_data(ssh, &data, &datalen);
2430 ssh_process_incoming_data(ssh, &data, &datalen);
2432 if (ssh->state == SSH_STATE_CLOSED)
2440 static int ssh_do_close(Ssh ssh, int notify_exit)
2443 struct ssh_channel *c;
2445 ssh->state = SSH_STATE_CLOSED;
2450 notify_remote_exit(ssh->frontend);
2455 * Now we must shut down any port- and X-forwarded channels going
2456 * through this connection.
2458 if (ssh->channels) {
2459 while (NULL != (c = index234(ssh->channels, 0))) {
2462 x11_close(c->u.x11.s);
2465 pfd_close(c->u.pfd.s);
2468 del234(ssh->channels, c); /* moving next one to index 0 */
2469 if (ssh->version == 2)
2470 bufchain_clear(&c->v.v2.outbuffer);
2475 * Go through port-forwardings, and close any associated
2476 * listening sockets.
2478 if (ssh->portfwds) {
2479 struct ssh_portfwd *pf;
2480 while (NULL != (pf = index234(ssh->portfwds, 0))) {
2481 /* Dispose of any listening socket. */
2483 pfd_terminate(pf->local);
2484 del234(ssh->portfwds, pf); /* moving next one to index 0 */
2492 static void ssh_log(Plug plug, int type, SockAddr addr, int port,
2493 const char *error_msg, int error_code)
2495 Ssh ssh = (Ssh) plug;
2496 char addrbuf[256], *msg;
2498 sk_getaddr(addr, addrbuf, lenof(addrbuf));
2501 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
2503 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
2509 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2512 Ssh ssh = (Ssh) plug;
2513 int need_notify = ssh_do_close(ssh, FALSE);
2515 if (!error_msg && !ssh->close_expected) {
2516 error_msg = "Server unexpectedly closed network connection";
2520 /* A socket error has occurred. */
2521 logevent(error_msg);
2522 connection_fatal(ssh->frontend, "%s", error_msg);
2524 logevent("Server closed network connection");
2527 notify_remote_exit(ssh->frontend);
2531 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2533 Ssh ssh = (Ssh) plug;
2534 ssh_gotdata(ssh, (unsigned char *)data, len);
2535 if (ssh->state == SSH_STATE_CLOSED) {
2536 ssh_do_close(ssh, TRUE);
2542 static void ssh_sent(Plug plug, int bufsize)
2544 Ssh ssh = (Ssh) plug;
2546 * If the send backlog on the SSH socket itself clears, we
2547 * should unthrottle the whole world if it was throttled.
2549 if (bufsize < SSH_MAX_BACKLOG)
2550 ssh_throttle_all(ssh, 0, bufsize);
2554 * Connect to specified host and port.
2555 * Returns an error message, or NULL on success.
2556 * Also places the canonical host name into `realhost'. It must be
2557 * freed by the caller.
2559 static const char *connect_to_host(Ssh ssh, char *host, int port,
2560 char **realhost, int nodelay, int keepalive)
2562 static const struct plug_function_table fn_table = {
2573 ssh->savedhost = snewn(1 + strlen(host), char);
2574 if (!ssh->savedhost)
2575 fatalbox("Out of memory");
2576 strcpy(ssh->savedhost, host);
2579 port = 22; /* default ssh port */
2580 ssh->savedport = port;
2585 logeventf(ssh, "Looking up host \"%s\"%s", host,
2586 (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
2587 (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
2588 addr = name_lookup(host, port, realhost, &ssh->cfg,
2589 ssh->cfg.addressfamily);
2590 if ((err = sk_addr_error(addr)) != NULL) {
2598 ssh->fn = &fn_table;
2599 ssh->s = new_connection(addr, *realhost, port,
2600 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
2601 if ((err = sk_socket_error(ssh->s)) != NULL) {
2603 notify_remote_exit(ssh->frontend);
2611 * Throttle or unthrottle the SSH connection.
2613 static void ssh1_throttle(Ssh ssh, int adjust)
2615 int old_count = ssh->v1_throttle_count;
2616 ssh->v1_throttle_count += adjust;
2617 assert(ssh->v1_throttle_count >= 0);
2618 if (ssh->v1_throttle_count && !old_count) {
2619 ssh_set_frozen(ssh, 1);
2620 } else if (!ssh->v1_throttle_count && old_count) {
2621 ssh_set_frozen(ssh, 0);
2626 * Throttle or unthrottle _all_ local data streams (for when sends
2627 * on the SSH connection itself back up).
2629 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2632 struct ssh_channel *c;
2634 if (enable == ssh->throttled_all)
2636 ssh->throttled_all = enable;
2637 ssh->overall_bufsize = bufsize;
2640 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2642 case CHAN_MAINSESSION:
2644 * This is treated separately, outside the switch.
2648 x11_override_throttle(c->u.x11.s, enable);
2651 /* Agent channels require no buffer management. */
2654 pfd_override_throttle(c->u.pfd.s, enable);
2661 * Username and password input, abstracted off into routines
2662 * reusable in several places - even between SSH1 and SSH2.
2665 /* Set up a username or password input loop on a given buffer. */
2666 static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2668 ssh->userpass_input_buffer = buffer;
2669 ssh->userpass_input_buflen = buflen;
2670 ssh->userpass_input_bufpos = 0;
2671 ssh->userpass_input_echo = echo;
2675 * Process some terminal data in the course of username/password
2676 * input. Returns >0 for success (line of input returned in
2677 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2678 * for inconclusive (keep waiting for more input please).
2680 static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2685 switch (c = *in++) {
2688 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2689 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2694 if (ssh->userpass_input_bufpos > 0) {
2695 if (ssh->userpass_input_echo)
2696 c_write_str(ssh, "\b \b");
2697 ssh->userpass_input_bufpos--;
2702 while (ssh->userpass_input_bufpos > 0) {
2703 if (ssh->userpass_input_echo)
2704 c_write_str(ssh, "\b \b");
2705 ssh->userpass_input_bufpos--;
2714 * This simplistic check for printability is disabled
2715 * when we're doing password input, because some people
2716 * have control characters in their passwords.o
2718 if ((!ssh->userpass_input_echo ||
2719 (c >= ' ' && c <= '~') ||
2720 ((unsigned char) c >= 160))
2721 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2722 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2723 if (ssh->userpass_input_echo)
2724 c_write(ssh, &c, 1);
2732 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
2734 Ssh ssh = (Ssh) sshv;
2736 ssh->agent_response = reply;
2737 ssh->agent_response_len = replylen;
2739 if (ssh->version == 1)
2740 do_ssh1_login(ssh, NULL, -1, NULL);
2742 do_ssh2_authconn(ssh, NULL, -1, NULL);
2745 static void ssh_dialog_callback(void *sshv, int ret)
2747 Ssh ssh = (Ssh) sshv;
2749 ssh->user_response = ret;
2751 if (ssh->version == 1)
2752 do_ssh1_login(ssh, NULL, -1, NULL);
2754 do_ssh2_transport(ssh, NULL, -1, NULL);
2757 * This may have unfrozen the SSH connection, so do a
2760 ssh_process_queued_incoming_data(ssh);
2763 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
2765 struct ssh_channel *c = (struct ssh_channel *)cv;
2767 void *sentreply = reply;
2770 /* Fake SSH_AGENT_FAILURE. */
2771 sentreply = "\0\0\0\1\5";
2774 if (ssh->version == 2) {
2775 ssh2_add_channel_data(c, sentreply, replylen);
2778 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2779 PKT_INT, c->remoteid,
2782 PKT_DATA, sentreply, replylen,
2791 * Handle the key exchange and user authentication phases.
2793 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2794 struct Packet *pktin)
2797 unsigned char cookie[8], *ptr;
2798 struct RSAKey servkey, hostkey;
2799 struct MD5Context md5c;
2800 struct do_ssh1_login_state {
2802 unsigned char *rsabuf, *keystr1, *keystr2;
2803 unsigned long supported_ciphers_mask, supported_auths_mask;
2804 int tried_publickey, tried_agent;
2805 int tis_auth_refused, ccard_auth_refused;
2806 unsigned char session_id[16];
2809 void *publickey_blob;
2810 int publickey_bloblen;
2816 unsigned char request[5], *response, *p;
2826 crState(do_ssh1_login_state);
2828 crBegin(ssh->do_ssh1_login_crstate);
2833 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
2834 bombout(("Public key packet not received"));
2838 logevent("Received public keys");
2840 ptr = ssh_pkt_getdata(pktin, 8);
2842 bombout(("SSH1 public key packet stopped before random cookie"));
2845 memcpy(cookie, ptr, 8);
2847 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2848 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
2849 bombout(("Failed to read SSH1 public keys from public key packet"));
2854 * Log the host key fingerprint.
2858 logevent("Host key fingerprint is:");
2859 strcpy(logmsg, " ");
2860 hostkey.comment = NULL;
2861 rsa_fingerprint(logmsg + strlen(logmsg),
2862 sizeof(logmsg) - strlen(logmsg), &hostkey);
2866 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2867 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2868 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
2870 ssh->v1_local_protoflags =
2871 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2872 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2875 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2876 MD5Update(&md5c, s->keystr1, servkey.bytes);
2877 MD5Update(&md5c, cookie, 8);
2878 MD5Final(s->session_id, &md5c);
2880 for (i = 0; i < 32; i++)
2881 ssh->session_key[i] = random_byte();
2884 * Verify that the `bits' and `bytes' parameters match.
2886 if (hostkey.bits > hostkey.bytes * 8 ||
2887 servkey.bits > servkey.bytes * 8) {
2888 bombout(("SSH1 public keys were badly formatted"));
2892 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2894 s->rsabuf = snewn(s->len, unsigned char);
2896 fatalbox("Out of memory");
2899 * Verify the host key.
2903 * First format the key into a string.
2905 int len = rsastr_len(&hostkey);
2906 char fingerprint[100];
2907 char *keystr = snewn(len, char);
2909 fatalbox("Out of memory");
2910 rsastr_fmt(keystr, &hostkey);
2911 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2913 ssh_set_frozen(ssh, 1);
2914 s->dlgret = verify_ssh_host_key(ssh->frontend,
2915 ssh->savedhost, ssh->savedport,
2916 "rsa", keystr, fingerprint,
2917 ssh_dialog_callback, ssh);
2919 if (s->dlgret < 0) {
2923 bombout(("Unexpected data from server while waiting"
2924 " for user host key response"));
2927 } while (pktin || inlen > 0);
2928 s->dlgret = ssh->user_response;
2930 ssh_set_frozen(ssh, 0);
2932 if (s->dlgret == 0) {
2933 ssh->close_expected = TRUE;
2934 ssh_closing((Plug)ssh, NULL, 0, 0);
2938 for (i = 0; i < 32; i++) {
2939 s->rsabuf[i] = ssh->session_key[i];
2941 s->rsabuf[i] ^= s->session_id[i];
2944 if (hostkey.bytes > servkey.bytes) {
2945 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2947 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2949 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
2951 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2954 bombout(("SSH1 public key encryptions failed due to bad formatting"));
2958 logevent("Encrypted session key");
2961 int cipher_chosen = 0, warn = 0;
2962 char *cipher_string = NULL;
2964 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2965 int next_cipher = ssh->cfg.ssh_cipherlist[i];
2966 if (next_cipher == CIPHER_WARN) {
2967 /* If/when we choose a cipher, warn about it */
2969 } else if (next_cipher == CIPHER_AES) {
2970 /* XXX Probably don't need to mention this. */
2971 logevent("AES not supported in SSH1, skipping");
2973 switch (next_cipher) {
2974 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
2975 cipher_string = "3DES"; break;
2976 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
2977 cipher_string = "Blowfish"; break;
2978 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
2979 cipher_string = "single-DES"; break;
2981 if (s->supported_ciphers_mask & (1 << s->cipher_type))
2985 if (!cipher_chosen) {
2986 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2987 bombout(("Server violates SSH 1 protocol by not "
2988 "supporting 3DES encryption"));
2990 /* shouldn't happen */
2991 bombout(("No supported ciphers found"));
2995 /* Warn about chosen cipher if necessary. */
2997 ssh_set_frozen(ssh, 1);
2998 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
2999 ssh_dialog_callback, ssh);
3000 if (s->dlgret < 0) {
3004 bombout(("Unexpected data from server while waiting"
3005 " for user response"));
3008 } while (pktin || inlen > 0);
3009 s->dlgret = ssh->user_response;
3011 ssh_set_frozen(ssh, 0);
3012 if (s->dlgret == 0) {
3013 ssh->close_expected = TRUE;
3014 ssh_closing((Plug)ssh, NULL, 0, 0);
3019 switch (s->cipher_type) {
3020 case SSH_CIPHER_3DES:
3021 logevent("Using 3DES encryption");
3023 case SSH_CIPHER_DES:
3024 logevent("Using single-DES encryption");
3026 case SSH_CIPHER_BLOWFISH:
3027 logevent("Using Blowfish encryption");
3031 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3032 PKT_CHAR, s->cipher_type,
3033 PKT_DATA, cookie, 8,
3034 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3035 PKT_DATA, s->rsabuf, s->len,
3036 PKT_INT, ssh->v1_local_protoflags, PKT_END);
3038 logevent("Trying to enable encryption...");
3042 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3043 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3045 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3046 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
3047 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
3049 ssh->crcda_ctx = crcda_make_context();
3050 logevent("Installing CRC compensation attack detector");
3052 if (servkey.modulus) {
3053 sfree(servkey.modulus);
3054 servkey.modulus = NULL;
3056 if (servkey.exponent) {
3057 sfree(servkey.exponent);
3058 servkey.exponent = NULL;
3060 if (hostkey.modulus) {
3061 sfree(hostkey.modulus);
3062 hostkey.modulus = NULL;
3064 if (hostkey.exponent) {
3065 sfree(hostkey.exponent);
3066 hostkey.exponent = NULL;
3070 if (pktin->type != SSH1_SMSG_SUCCESS) {
3071 bombout(("Encryption not successfully enabled"));
3075 logevent("Successfully started encryption");
3079 if (!*ssh->cfg.username) {
3080 if (ssh_get_line && !ssh_getline_pw_only) {
3081 if (!ssh_get_line("login as: ",
3082 s->username, sizeof(s->username), FALSE)) {
3084 * get_line failed to get a username.
3087 logevent("No username provided. Abandoning session.");
3088 ssh->close_expected = TRUE;
3089 ssh_closing((Plug)ssh, NULL, 0, 0);
3093 int ret; /* need not be kept over crReturn */
3094 c_write_str(ssh, "login as: ");
3097 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
3099 crWaitUntil(!pktin);
3100 ret = process_userpass_input(ssh, in, inlen);
3104 c_write_str(ssh, "\r\n");
3107 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
3108 s->username[sizeof(s->username)-1] = '\0';
3111 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
3113 char userlog[22 + sizeof(s->username)];
3114 sprintf(userlog, "Sent username \"%s\"", s->username);
3116 if (flags & FLAG_INTERACTIVE &&
3117 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3118 strcat(userlog, "\r\n");
3119 c_write_str(ssh, userlog);
3126 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
3127 /* We must not attempt PK auth. Pretend we've already tried it. */
3128 s->tried_publickey = s->tried_agent = 1;
3130 s->tried_publickey = s->tried_agent = 0;
3132 s->tis_auth_refused = s->ccard_auth_refused = 0;
3133 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
3134 if (!filename_is_null(ssh->cfg.keyfile)) {
3135 if (!rsakey_pubblob(&ssh->cfg.keyfile,
3136 &s->publickey_blob, &s->publickey_bloblen, NULL))
3137 s->publickey_blob = NULL;
3139 s->publickey_blob = NULL;
3141 while (pktin->type == SSH1_SMSG_FAILURE) {
3142 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
3144 if (agent_exists() && !s->tried_agent) {
3146 * Attempt RSA authentication using Pageant.
3152 logevent("Pageant is running. Requesting keys.");
3154 /* Request the keys held by the agent. */
3155 PUT_32BIT(s->request, 1);
3156 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
3157 if (!agent_query(s->request, 5, &r, &s->responselen,
3158 ssh_agent_callback, ssh)) {
3162 bombout(("Unexpected data from server while waiting"
3163 " for agent response"));
3166 } while (pktin || inlen > 0);
3167 r = ssh->agent_response;
3168 s->responselen = ssh->agent_response_len;
3170 s->response = (unsigned char *) r;
3171 if (s->response && s->responselen >= 5 &&
3172 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3173 s->p = s->response + 5;
3174 s->nkeys = GET_32BIT(s->p);
3176 logeventf(ssh, "Pageant has %d SSH1 keys", s->nkeys);
3177 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
3178 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
3179 if (s->publickey_blob &&
3180 !memcmp(s->p, s->publickey_blob,
3181 s->publickey_bloblen)) {
3182 logevent("This key matches configured key file");
3183 s->tried_publickey = 1;
3188 do { /* do while (0) to make breaking easy */
3189 n = ssh1_read_bignum
3190 (s->p, s->responselen-(s->p-s->response),
3195 n = ssh1_read_bignum
3196 (s->p, s->responselen-(s->p-s->response),
3201 if (s->responselen - (s->p-s->response) < 4)
3203 s->commentlen = GET_32BIT(s->p);
3205 if (s->responselen - (s->p-s->response) <
3208 s->commentp = (char *)s->p;
3209 s->p += s->commentlen;
3213 logevent("Pageant key list packet was truncated");
3217 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3218 PKT_BIGNUM, s->key.modulus, PKT_END);
3220 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3221 logevent("Key refused");
3224 logevent("Received RSA challenge");
3225 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3226 bombout(("Server's RSA challenge was badly formatted"));
3231 char *agentreq, *q, *ret;
3234 len = 1 + 4; /* message type, bit count */
3235 len += ssh1_bignum_length(s->key.exponent);
3236 len += ssh1_bignum_length(s->key.modulus);
3237 len += ssh1_bignum_length(s->challenge);
3238 len += 16; /* session id */
3239 len += 4; /* response format */
3240 agentreq = snewn(4 + len, char);
3241 PUT_32BIT(agentreq, len);
3243 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
3244 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
3246 q += ssh1_write_bignum(q, s->key.exponent);
3247 q += ssh1_write_bignum(q, s->key.modulus);
3248 q += ssh1_write_bignum(q, s->challenge);
3249 memcpy(q, s->session_id, 16);
3251 PUT_32BIT(q, 1); /* response format */
3252 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3253 ssh_agent_callback, ssh)) {
3258 bombout(("Unexpected data from server"
3259 " while waiting for agent"
3263 } while (pktin || inlen > 0);
3264 vret = ssh->agent_response;
3265 retlen = ssh->agent_response_len;
3270 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3271 logevent("Sending Pageant's response");
3272 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3273 PKT_DATA, ret + 5, 16,
3277 if (pktin->type == SSH1_SMSG_SUCCESS) {
3279 ("Pageant's response accepted");
3280 if (flags & FLAG_VERBOSE) {
3281 c_write_str(ssh, "Authenticated using"
3283 c_write(ssh, s->commentp,
3285 c_write_str(ssh, "\" from agent\r\n");
3290 ("Pageant's response not accepted");
3293 ("Pageant failed to answer challenge");
3297 logevent("No reply received from Pageant");
3300 freebn(s->key.exponent);
3301 freebn(s->key.modulus);
3302 freebn(s->challenge);
3311 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
3312 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
3314 if (ssh->cfg.try_tis_auth &&
3315 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3316 !s->tis_auth_refused) {
3317 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
3318 logevent("Requested TIS authentication");
3319 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
3321 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
3322 logevent("TIS authentication declined");
3323 if (flags & FLAG_INTERACTIVE)
3324 c_write_str(ssh, "TIS authentication refused.\r\n");
3325 s->tis_auth_refused = 1;
3331 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3333 bombout(("TIS challenge packet was badly formed"));
3336 logevent("Received TIS challenge");
3337 if (challengelen > sizeof(s->prompt) - 1)
3338 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3339 memcpy(s->prompt, challenge, challengelen);
3340 /* Prompt heuristic comes from OpenSSH */
3341 strncpy(s->prompt + challengelen,
3342 memchr(s->prompt, '\n', challengelen) ?
3343 "": "\r\nResponse: ",
3344 (sizeof s->prompt) - challengelen);
3345 s->prompt[(sizeof s->prompt) - 1] = '\0';
3348 if (ssh->cfg.try_tis_auth &&
3349 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3350 !s->ccard_auth_refused) {
3351 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
3352 logevent("Requested CryptoCard authentication");
3353 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
3355 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
3356 logevent("CryptoCard authentication declined");
3357 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3358 s->ccard_auth_refused = 1;
3364 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3366 bombout(("CryptoCard challenge packet was badly formed"));
3369 logevent("Received CryptoCard challenge");
3370 if (challengelen > sizeof(s->prompt) - 1)
3371 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3372 memcpy(s->prompt, challenge, challengelen);
3373 strncpy(s->prompt + challengelen,
3374 memchr(s->prompt, '\n', challengelen) ?
3375 "" : "\r\nResponse: ",
3376 sizeof(s->prompt) - challengelen);
3377 s->prompt[sizeof(s->prompt) - 1] = '\0';
3380 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3381 sprintf(s->prompt, "%.90s@%.90s's password: ",
3382 s->username, ssh->savedhost);
3384 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3385 char *comment = NULL;
3387 if (flags & FLAG_VERBOSE)
3388 c_write_str(ssh, "Trying public key authentication.\r\n");
3389 logeventf(ssh, "Trying public key \"%s\"",
3390 filename_to_str(&ssh->cfg.keyfile));
3391 type = key_type(&ssh->cfg.keyfile);
3392 if (type != SSH_KEYTYPE_SSH1) {
3393 char *msg = dupprintf("Key is of wrong type (%s)",
3394 key_type_to_str(type));
3396 c_write_str(ssh, msg);
3397 c_write_str(ssh, "\r\n");
3399 s->tried_publickey = 1;
3402 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
3403 if (flags & FLAG_VERBOSE)
3404 c_write_str(ssh, "No passphrase required.\r\n");
3407 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
3412 * Show password prompt, having first obtained it via a TIS
3413 * or CryptoCard exchange if we're doing TIS or CryptoCard
3417 if (!ssh_get_line(s->prompt, s->password,
3418 sizeof(s->password), TRUE)) {
3420 * get_line failed to get a password (for example
3421 * because one was supplied on the command line
3422 * which has already failed to work). Terminate.
3424 send_packet(ssh, SSH1_MSG_DISCONNECT,
3425 PKT_STR, "No more passwords available to try",
3427 logevent("Unable to authenticate");
3428 connection_fatal(ssh->frontend, "Unable to authenticate");
3429 ssh->close_expected = TRUE;
3430 ssh_closing((Plug)ssh, NULL, 0, 0);
3434 /* Prompt may have come from server. We've munged it a bit, so
3435 * we know it to be zero-terminated at least once. */
3436 int ret; /* need not be saved over crReturn */
3437 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3440 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
3442 crWaitUntil(!pktin);
3443 ret = process_userpass_input(ssh, in, inlen);
3447 c_write_str(ssh, "\r\n");
3451 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3453 * Try public key authentication with the specified
3456 s->tried_publickey = 1;
3459 const char *error = NULL;
3460 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3463 c_write_str(ssh, "Couldn't load private key from ");
3464 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
3465 c_write_str(ssh, " (");
3466 c_write_str(ssh, error);
3467 c_write_str(ssh, ").\r\n");
3468 continue; /* go and try password */
3471 c_write_str(ssh, "Wrong passphrase.\r\n");
3472 s->tried_publickey = 0;
3473 continue; /* try again */
3478 * Send a public key attempt.
3480 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3481 PKT_BIGNUM, s->key.modulus, PKT_END);
3484 if (pktin->type == SSH1_SMSG_FAILURE) {
3485 c_write_str(ssh, "Server refused our public key.\r\n");
3486 continue; /* go and try password */
3488 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3489 bombout(("Bizarre response to offer of public key"));
3495 unsigned char buffer[32];
3496 Bignum challenge, response;
3498 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3499 bombout(("Server's RSA challenge was badly formatted"));
3502 response = rsadecrypt(challenge, &s->key);
3503 freebn(s->key.private_exponent);/* burn the evidence */
3505 for (i = 0; i < 32; i++) {
3506 buffer[i] = bignum_byte(response, 31 - i);
3510 MD5Update(&md5c, buffer, 32);
3511 MD5Update(&md5c, s->session_id, 16);
3512 MD5Final(buffer, &md5c);
3514 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3515 PKT_DATA, buffer, 16, PKT_END);
3522 if (pktin->type == SSH1_SMSG_FAILURE) {
3523 if (flags & FLAG_VERBOSE)
3524 c_write_str(ssh, "Failed to authenticate with"
3525 " our public key.\r\n");
3526 continue; /* go and try password */
3527 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3528 bombout(("Bizarre response to RSA authentication response"));
3532 break; /* we're through! */
3534 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3536 * Defence against traffic analysis: we send a
3537 * whole bunch of packets containing strings of
3538 * different lengths. One of these strings is the
3539 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3540 * The others are all random data in
3541 * SSH1_MSG_IGNORE packets. This way a passive
3542 * listener can't tell which is the password, and
3543 * hence can't deduce the password length.
3545 * Anybody with a password length greater than 16
3546 * bytes is going to have enough entropy in their
3547 * password that a listener won't find it _that_
3548 * much help to know how long it is. So what we'll
3551 * - if password length < 16, we send 15 packets
3552 * containing string lengths 1 through 15
3554 * - otherwise, we let N be the nearest multiple
3555 * of 8 below the password length, and send 8
3556 * packets containing string lengths N through
3557 * N+7. This won't obscure the order of
3558 * magnitude of the password length, but it will
3559 * introduce a bit of extra uncertainty.
3561 * A few servers (the old 1.2.18 through 1.2.22)
3562 * can't deal with SSH1_MSG_IGNORE. For these
3563 * servers, we need an alternative defence. We make
3564 * use of the fact that the password is interpreted
3565 * as a C string: so we can append a NUL, then some
3568 * One server (a Cisco one) can deal with neither
3569 * SSH1_MSG_IGNORE _nor_ a padded password string.
3570 * For this server we are left with no defences
3571 * against password length sniffing.
3573 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
3575 * The server can deal with SSH1_MSG_IGNORE, so
3576 * we can use the primary defence.
3578 int bottom, top, pwlen, i;
3581 pwlen = strlen(s->password);
3583 bottom = 0; /* zero length passwords are OK! :-) */
3586 bottom = pwlen & ~7;
3590 assert(pwlen >= bottom && pwlen <= top);
3592 randomstr = snewn(top + 1, char);
3594 for (i = bottom; i <= top; i++) {
3596 defer_packet(ssh, s->pwpkt_type,
3597 PKTT_PASSWORD, PKT_STR, s->password,
3598 PKTT_OTHER, PKT_END);
3600 for (j = 0; j < i; j++) {
3602 randomstr[j] = random_byte();
3603 } while (randomstr[j] == '\0');
3605 randomstr[i] = '\0';
3606 defer_packet(ssh, SSH1_MSG_IGNORE,
3607 PKT_STR, randomstr, PKT_END);
3610 logevent("Sending password with camouflage packets");
3611 ssh_pkt_defersend(ssh);
3614 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3616 * The server can't deal with SSH1_MSG_IGNORE
3617 * but can deal with padded passwords, so we
3618 * can use the secondary defence.
3624 len = strlen(s->password);
3625 if (len < sizeof(string)) {
3627 strcpy(string, s->password);
3628 len++; /* cover the zero byte */
3629 while (len < sizeof(string)) {
3630 string[len++] = (char) random_byte();
3635 logevent("Sending length-padded password");
3636 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3637 PKT_INT, len, PKT_DATA, ss, len,
3638 PKTT_OTHER, PKT_END);
3641 * The server has _both_
3642 * BUG_CHOKES_ON_SSH1_IGNORE and
3643 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3644 * therefore nothing we can do.
3647 len = strlen(s->password);
3648 logevent("Sending unpadded password");
3649 send_packet(ssh, s->pwpkt_type,
3650 PKTT_PASSWORD, PKT_INT, len,
3651 PKT_DATA, s->password, len,
3652 PKTT_OTHER, PKT_END);
3655 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3656 PKT_STR, s->password, PKTT_OTHER, PKT_END);
3659 logevent("Sent password");
3660 memset(s->password, 0, strlen(s->password));
3662 if (pktin->type == SSH1_SMSG_FAILURE) {
3663 if (flags & FLAG_VERBOSE)
3664 c_write_str(ssh, "Access denied\r\n");
3665 logevent("Authentication refused");
3666 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3667 bombout(("Strange packet received, type %d", pktin->type));
3672 logevent("Authentication successful");
3677 void sshfwd_close(struct ssh_channel *c)
3681 if (ssh->state != SSH_STATE_SESSION) {
3682 assert(ssh->state == SSH_STATE_CLOSED);
3686 if (c && !c->closes) {
3688 * If halfopen is true, we have sent
3689 * CHANNEL_OPEN for this channel, but it hasn't even been
3690 * acknowledged by the server. So we must set a close flag
3691 * on it now, and then when the server acks the channel
3692 * open, we can close it then.
3695 if (ssh->version == 1) {
3696 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3699 struct Packet *pktout;
3700 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3701 ssh2_pkt_adduint32(pktout, c->remoteid);
3702 ssh2_pkt_send(ssh, pktout);
3705 c->closes = 1; /* sent MSG_CLOSE */
3706 if (c->type == CHAN_X11) {
3708 logevent("Forwarded X11 connection terminated");
3709 } else if (c->type == CHAN_SOCKDATA ||
3710 c->type == CHAN_SOCKDATA_DORMANT) {
3712 logevent("Forwarded port closed");
3717 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3721 if (ssh->state != SSH_STATE_SESSION) {
3722 assert(ssh->state == SSH_STATE_CLOSED);
3726 if (ssh->version == 1) {
3727 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3728 PKT_INT, c->remoteid,
3730 PKT_INT, len, PKT_DATA, buf, len,
3731 PKTT_OTHER, PKT_END);
3733 * In SSH1 we can return 0 here - implying that forwarded
3734 * connections are never individually throttled - because
3735 * the only circumstance that can cause throttling will be
3736 * the whole SSH connection backing up, in which case
3737 * _everything_ will be throttled as a whole.
3741 ssh2_add_channel_data(c, buf, len);
3742 return ssh2_try_send(c);
3746 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3750 if (ssh->state != SSH_STATE_SESSION) {
3751 assert(ssh->state == SSH_STATE_CLOSED);
3755 if (ssh->version == 1) {
3756 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3757 c->v.v1.throttling = 0;
3758 ssh1_throttle(ssh, -1);
3761 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3765 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
3767 struct queued_handler *qh = ssh->qhead;
3771 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
3774 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
3775 ssh->packet_dispatch[qh->msg1] = NULL;
3778 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
3779 ssh->packet_dispatch[qh->msg2] = NULL;
3783 ssh->qhead = qh->next;
3785 if (ssh->qhead->msg1 > 0) {
3786 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
3787 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
3789 if (ssh->qhead->msg2 > 0) {
3790 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
3791 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
3794 ssh->qhead = ssh->qtail = NULL;
3795 ssh->packet_dispatch[pktin->type] = NULL;
3798 qh->handler(ssh, pktin, qh->ctx);
3803 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
3804 chandler_fn_t handler, void *ctx)
3806 struct queued_handler *qh;
3808 qh = snew(struct queued_handler);
3811 qh->handler = handler;
3815 if (ssh->qtail == NULL) {
3819 assert(ssh->packet_dispatch[qh->msg1] == NULL);
3820 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
3823 assert(ssh->packet_dispatch[qh->msg2] == NULL);
3824 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
3827 ssh->qtail->next = qh;
3832 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
3834 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
3836 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
3837 SSH2_MSG_REQUEST_SUCCESS)) {
3838 logeventf(ssh, "Remote port forwarding from %s enabled",
3841 logeventf(ssh, "Remote port forwarding from %s refused",
3844 rpf = del234(ssh->rportfwds, pf);
3850 static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
3852 const char *portfwd_strptr = cfg->portfwd;
3853 struct ssh_portfwd *epf;
3856 if (!ssh->portfwds) {
3857 ssh->portfwds = newtree234(ssh_portcmp);
3860 * Go through the existing port forwardings and tag them
3861 * with status==DESTROY. Any that we want to keep will be
3862 * re-enabled (status==KEEP) as we go through the
3863 * configuration and find out which bits are the same as
3866 struct ssh_portfwd *epf;
3868 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3869 epf->status = DESTROY;
3872 while (*portfwd_strptr) {
3873 char address_family, type;
3874 int sport,dport,sserv,dserv;
3875 char sports[256], dports[256], saddr[256], host[256];
3878 address_family = 'A';
3880 if (*portfwd_strptr == 'A' ||
3881 *portfwd_strptr == '4' ||
3882 *portfwd_strptr == '6')
3883 address_family = *portfwd_strptr++;
3884 if (*portfwd_strptr == 'L' ||
3885 *portfwd_strptr == 'R' ||
3886 *portfwd_strptr == 'D')
3887 type = *portfwd_strptr++;
3892 while (*portfwd_strptr && *portfwd_strptr != '\t') {
3893 if (*portfwd_strptr == ':') {
3895 * We've seen a colon in the middle of the
3896 * source port number. This means that
3897 * everything we've seen until now is the
3898 * source _address_, so we'll move it into
3899 * saddr and start sports from the beginning
3904 if (ssh->version == 1 && type == 'R') {
3905 logeventf(ssh, "SSH1 cannot handle remote source address "
3906 "spec \"%s\"; ignoring", sports);
3908 strcpy(saddr, sports);
3911 if (n < 255) sports[n++] = *portfwd_strptr++;
3915 if (*portfwd_strptr == '\t')
3918 while (*portfwd_strptr && *portfwd_strptr != ':') {
3919 if (n < 255) host[n++] = *portfwd_strptr++;
3922 if (*portfwd_strptr == ':')
3925 while (*portfwd_strptr) {
3926 if (n < 255) dports[n++] = *portfwd_strptr++;
3930 dport = atoi(dports);
3934 dport = net_service_lookup(dports);
3936 logeventf(ssh, "Service lookup failed for destination"
3937 " port \"%s\"", dports);
3941 while (*portfwd_strptr) portfwd_strptr++;
3945 portfwd_strptr++; /* eat the NUL and move to next one */
3947 sport = atoi(sports);
3951 sport = net_service_lookup(sports);
3953 logeventf(ssh, "Service lookup failed for source"
3954 " port \"%s\"", sports);
3957 if (sport && dport) {
3958 /* Set up a description of the source port. */
3959 struct ssh_portfwd *pfrec, *epfrec;
3961 pfrec = snew(struct ssh_portfwd);
3963 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
3964 pfrec->sserv = sserv ? dupstr(sports) : NULL;
3965 pfrec->sport = sport;
3966 pfrec->daddr = *host ? dupstr(host) : NULL;
3967 pfrec->dserv = dserv ? dupstr(dports) : NULL;
3968 pfrec->dport = dport;
3969 pfrec->local = NULL;
3970 pfrec->remote = NULL;
3971 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
3972 address_family == '6' ? ADDRTYPE_IPV6 :
3975 epfrec = add234(ssh->portfwds, pfrec);
3976 if (epfrec != pfrec) {
3978 * We already have a port forwarding with precisely
3979 * these parameters. Hence, no need to do anything;
3980 * simply tag the existing one as KEEP.
3982 epfrec->status = KEEP;
3983 free_portfwd(pfrec);
3985 pfrec->status = CREATE;
3991 * Now go through and destroy any port forwardings which were
3994 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3995 if (epf->status == DESTROY) {
3998 message = dupprintf("%s port forwarding from %s%s%d",
3999 epf->type == 'L' ? "local" :
4000 epf->type == 'R' ? "remote" : "dynamic",
4001 epf->saddr ? epf->saddr : "",
4002 epf->saddr ? ":" : "",
4005 if (epf->type != 'D') {
4006 char *msg2 = dupprintf("%s to %s:%d", message,
4007 epf->daddr, epf->dport);
4012 logeventf(ssh, "Cancelling %s", message);
4016 struct ssh_rportfwd *rpf = epf->remote;
4017 struct Packet *pktout;
4020 * Cancel the port forwarding at the server
4023 if (ssh->version == 1) {
4025 * We cannot cancel listening ports on the
4026 * server side in SSH1! There's no message
4027 * to support it. Instead, we simply remove
4028 * the rportfwd record from the local end
4029 * so that any connections the server tries
4030 * to make on it are rejected.
4033 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4034 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
4035 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
4037 ssh2_pkt_addstring(pktout, epf->saddr);
4038 } else if (ssh->cfg.rport_acceptall) {
4039 /* XXX: ssh->cfg.rport_acceptall may not represent
4040 * what was used to open the original connection,
4041 * since it's reconfigurable. */
4042 ssh2_pkt_addstring(pktout, "0.0.0.0");
4044 ssh2_pkt_addstring(pktout, "127.0.0.1");
4046 ssh2_pkt_adduint32(pktout, epf->sport);
4047 ssh2_pkt_send(ssh, pktout);
4050 del234(ssh->rportfwds, rpf);
4052 } else if (epf->local) {
4053 pfd_terminate(epf->local);
4056 delpos234(ssh->portfwds, i);
4058 i--; /* so we don't skip one in the list */
4062 * And finally, set up any new port forwardings (status==CREATE).
4064 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4065 if (epf->status == CREATE) {
4066 char *sportdesc, *dportdesc;
4067 sportdesc = dupprintf("%s%s%s%s%d%s",
4068 epf->saddr ? epf->saddr : "",
4069 epf->saddr ? ":" : "",
4070 epf->sserv ? epf->sserv : "",
4071 epf->sserv ? "(" : "",
4073 epf->sserv ? ")" : "");
4074 if (epf->type == 'D') {
4077 dportdesc = dupprintf("%s:%s%s%d%s",
4079 epf->dserv ? epf->dserv : "",
4080 epf->dserv ? "(" : "",
4082 epf->dserv ? ")" : "");
4085 if (epf->type == 'L') {
4086 const char *err = pfd_addforward(epf->daddr, epf->dport,
4087 epf->saddr, epf->sport,
4090 epf->addressfamily);
4092 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
4093 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4094 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4095 sportdesc, dportdesc,
4096 err ? " failed: " : "", err ? err : "");
4097 } else if (epf->type == 'D') {
4098 const char *err = pfd_addforward(NULL, -1,
4099 epf->saddr, epf->sport,
4102 epf->addressfamily);
4104 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
4105 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4106 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4108 err ? " failed: " : "", err ? err : "");
4110 struct ssh_rportfwd *pf;
4113 * Ensure the remote port forwardings tree exists.
4115 if (!ssh->rportfwds) {
4116 if (ssh->version == 1)
4117 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
4119 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4122 pf = snew(struct ssh_rportfwd);
4123 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
4124 pf->dhost[lenof(pf->dhost)-1] = '\0';
4125 pf->dport = epf->dport;
4126 pf->sport = epf->sport;
4127 if (add234(ssh->rportfwds, pf) != pf) {
4128 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
4129 epf->daddr, epf->dport);
4132 logeventf(ssh, "Requesting remote port %s"
4133 " forward to %s", sportdesc, dportdesc);
4135 pf->sportdesc = sportdesc;
4140 if (ssh->version == 1) {
4141 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
4142 PKT_INT, epf->sport,
4143 PKT_STR, epf->daddr,
4144 PKT_INT, epf->dport,
4146 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4148 ssh_rportfwd_succfail, pf);
4150 struct Packet *pktout;
4151 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4152 ssh2_pkt_addstring(pktout, "tcpip-forward");
4153 ssh2_pkt_addbool(pktout, 1);/* want reply */
4155 ssh2_pkt_addstring(pktout, epf->saddr);
4156 } else if (cfg->rport_acceptall) {
4157 ssh2_pkt_addstring(pktout, "0.0.0.0");
4159 ssh2_pkt_addstring(pktout, "127.0.0.1");
4161 ssh2_pkt_adduint32(pktout, epf->sport);
4162 ssh2_pkt_send(ssh, pktout);
4164 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4165 SSH2_MSG_REQUEST_FAILURE,
4166 ssh_rportfwd_succfail, pf);
4175 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4178 int stringlen, bufsize;
4180 ssh_pkt_getstring(pktin, &string, &stringlen);
4181 if (string == NULL) {
4182 bombout(("Incoming terminal data packet was badly formed"));
4186 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4188 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4189 ssh->v1_stdout_throttling = 1;
4190 ssh1_throttle(ssh, +1);
4194 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4196 /* Remote side is trying to open a channel to talk to our
4197 * X-Server. Give them back a local channel number. */
4198 struct ssh_channel *c;
4199 int remoteid = ssh_pkt_getuint32(pktin);
4201 logevent("Received X11 connect request");
4202 /* Refuse if X11 forwarding is disabled. */
4203 if (!ssh->X11_fwd_enabled) {
4204 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4205 PKT_INT, remoteid, PKT_END);
4206 logevent("Rejected X11 connect request");
4208 c = snew(struct ssh_channel);
4211 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
4212 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
4213 logevent("Opening X11 forward connection failed");
4215 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4216 PKT_INT, remoteid, PKT_END);
4219 ("Opening X11 forward connection succeeded");
4220 c->remoteid = remoteid;
4221 c->halfopen = FALSE;
4222 c->localid = alloc_channel_id(ssh);
4224 c->v.v1.throttling = 0;
4225 c->type = CHAN_X11; /* identify channel type */
4226 add234(ssh->channels, c);
4227 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4228 PKT_INT, c->remoteid, PKT_INT,
4229 c->localid, PKT_END);
4230 logevent("Opened X11 forward channel");
4235 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4237 /* Remote side is trying to open a channel to talk to our
4238 * agent. Give them back a local channel number. */
4239 struct ssh_channel *c;
4240 int remoteid = ssh_pkt_getuint32(pktin);
4242 /* Refuse if agent forwarding is disabled. */
4243 if (!ssh->agentfwd_enabled) {
4244 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4245 PKT_INT, remoteid, PKT_END);
4247 c = snew(struct ssh_channel);
4249 c->remoteid = remoteid;
4250 c->halfopen = FALSE;
4251 c->localid = alloc_channel_id(ssh);
4253 c->v.v1.throttling = 0;
4254 c->type = CHAN_AGENT; /* identify channel type */
4255 c->u.a.lensofar = 0;
4256 add234(ssh->channels, c);
4257 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4258 PKT_INT, c->remoteid, PKT_INT, c->localid,
4263 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4265 /* Remote side is trying to open a channel to talk to a
4266 * forwarded port. Give them back a local channel number. */
4267 struct ssh_channel *c;
4268 struct ssh_rportfwd pf, *pfp;
4273 c = snew(struct ssh_channel);
4276 remoteid = ssh_pkt_getuint32(pktin);
4277 ssh_pkt_getstring(pktin, &host, &hostsize);
4278 port = ssh_pkt_getuint32(pktin);
4280 if (hostsize >= lenof(pf.dhost))
4281 hostsize = lenof(pf.dhost)-1;
4282 memcpy(pf.dhost, host, hostsize);
4283 pf.dhost[hostsize] = '\0';
4285 pfp = find234(ssh->rportfwds, &pf, NULL);
4288 logeventf(ssh, "Rejected remote port open request for %s:%d",
4290 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4291 PKT_INT, remoteid, PKT_END);
4293 logeventf(ssh, "Received remote port open request for %s:%d",
4295 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
4296 c, &ssh->cfg, pfp->pfrec->addressfamily);
4298 logeventf(ssh, "Port open failed: %s", e);
4300 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4301 PKT_INT, remoteid, PKT_END);
4303 c->remoteid = remoteid;
4304 c->halfopen = FALSE;
4305 c->localid = alloc_channel_id(ssh);
4307 c->v.v1.throttling = 0;
4308 c->type = CHAN_SOCKDATA; /* identify channel type */
4309 add234(ssh->channels, c);
4310 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4311 PKT_INT, c->remoteid, PKT_INT,
4312 c->localid, PKT_END);
4313 logevent("Forwarded port opened successfully");
4318 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4320 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4321 unsigned int localid = ssh_pkt_getuint32(pktin);
4322 struct ssh_channel *c;
4324 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4325 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4326 c->remoteid = localid;
4327 c->halfopen = FALSE;
4328 c->type = CHAN_SOCKDATA;
4329 c->v.v1.throttling = 0;
4330 pfd_confirm(c->u.pfd.s);
4333 if (c && c->closes) {
4335 * We have a pending close on this channel,
4336 * which we decided on before the server acked
4337 * the channel open. So now we know the
4338 * remoteid, we can close it again.
4340 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4341 PKT_INT, c->remoteid, PKT_END);
4345 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4347 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4348 struct ssh_channel *c;
4350 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4351 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4352 logevent("Forwarded connection refused by server");
4353 pfd_close(c->u.pfd.s);
4354 del234(ssh->channels, c);
4359 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4361 /* Remote side closes a channel. */
4362 unsigned i = ssh_pkt_getuint32(pktin);
4363 struct ssh_channel *c;
4364 c = find234(ssh->channels, &i, ssh_channelfind);
4365 if (c && !c->halfopen) {
4368 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4370 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4371 logevent("Forwarded X11 connection terminated");
4372 assert(c->u.x11.s != NULL);
4373 x11_close(c->u.x11.s);
4376 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4377 logevent("Forwarded port closed");
4378 assert(c->u.pfd.s != NULL);
4379 pfd_close(c->u.pfd.s);
4383 c->closes |= (closetype << 2); /* seen this message */
4384 if (!(c->closes & closetype)) {
4385 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4387 c->closes |= closetype; /* sent it too */
4390 if (c->closes == 15) {
4391 del234(ssh->channels, c);
4395 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4396 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4397 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4402 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4404 /* Data sent down one of our channels. */
4405 int i = ssh_pkt_getuint32(pktin);
4408 struct ssh_channel *c;
4410 ssh_pkt_getstring(pktin, &p, &len);
4412 c = find234(ssh->channels, &i, ssh_channelfind);
4417 bufsize = x11_send(c->u.x11.s, p, len);
4420 bufsize = pfd_send(c->u.pfd.s, p, len);
4423 /* Data for an agent message. Buffer it. */
4425 if (c->u.a.lensofar < 4) {
4426 unsigned int l = min(4 - c->u.a.lensofar, len);
4427 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4431 c->u.a.lensofar += l;
4433 if (c->u.a.lensofar == 4) {
4435 4 + GET_32BIT(c->u.a.msglen);
4436 c->u.a.message = snewn(c->u.a.totallen,
4438 memcpy(c->u.a.message, c->u.a.msglen, 4);
4440 if (c->u.a.lensofar >= 4 && len > 0) {
4442 min(c->u.a.totallen - c->u.a.lensofar,
4444 memcpy(c->u.a.message + c->u.a.lensofar, p,
4448 c->u.a.lensofar += l;
4450 if (c->u.a.lensofar == c->u.a.totallen) {
4453 if (agent_query(c->u.a.message,
4456 ssh_agentf_callback, c))
4457 ssh_agentf_callback(c, reply, replylen);
4458 sfree(c->u.a.message);
4459 c->u.a.lensofar = 0;
4462 bufsize = 0; /* agent channels never back up */
4465 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4466 c->v.v1.throttling = 1;
4467 ssh1_throttle(ssh, +1);
4472 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
4474 ssh->exitcode = ssh_pkt_getuint32(pktin);
4475 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
4476 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4478 * In case `helpful' firewalls or proxies tack
4479 * extra human-readable text on the end of the
4480 * session which we might mistake for another
4481 * encrypted packet, we close the session once
4482 * we've sent EXIT_CONFIRMATION.
4484 ssh->close_expected = TRUE;
4485 ssh_closing((Plug)ssh, NULL, 0, 0);
4488 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
4489 struct Packet *pktin)
4491 crBegin(ssh->do_ssh1_connection_crstate);
4493 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
4494 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
4495 ssh1_smsg_stdout_stderr_data;
4497 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
4498 ssh1_msg_channel_open_confirmation;
4499 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
4500 ssh1_msg_channel_open_failure;
4501 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
4502 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
4503 ssh1_msg_channel_close;
4504 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
4505 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
4507 if (ssh->cfg.agentfwd && agent_exists()) {
4508 logevent("Requesting agent forwarding");
4509 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
4513 if (pktin->type != SSH1_SMSG_SUCCESS
4514 && pktin->type != SSH1_SMSG_FAILURE) {
4515 bombout(("Protocol confusion"));
4517 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4518 logevent("Agent forwarding refused");
4520 logevent("Agent forwarding enabled");
4521 ssh->agentfwd_enabled = TRUE;
4522 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
4526 if (ssh->cfg.x11_forward) {
4527 char proto[20], data[64];
4528 logevent("Requesting X11 forwarding");
4529 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
4530 data, sizeof(data), ssh->cfg.x11_auth);
4531 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
4532 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
4533 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4534 PKT_STR, proto, PKT_STR, data,
4535 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
4538 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4539 PKT_STR, proto, PKT_STR, data, PKT_END);
4544 if (pktin->type != SSH1_SMSG_SUCCESS
4545 && pktin->type != SSH1_SMSG_FAILURE) {
4546 bombout(("Protocol confusion"));
4548 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4549 logevent("X11 forwarding refused");
4551 logevent("X11 forwarding enabled");
4552 ssh->X11_fwd_enabled = TRUE;
4553 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
4557 ssh_setup_portfwd(ssh, &ssh->cfg);
4558 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
4560 if (!ssh->cfg.nopty) {
4561 /* Unpick the terminal-speed string. */
4562 /* XXX perhaps we should allow no speeds to be sent. */
4563 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4564 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
4565 /* Send the pty request. */
4566 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
4567 PKT_STR, ssh->cfg.termtype,
4568 PKT_INT, ssh->term_height,
4569 PKT_INT, ssh->term_width,
4570 PKT_INT, 0, PKT_INT, 0, /* width,height in pixels */
4571 PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */
4572 PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */
4573 PKT_CHAR, 0, PKT_END);
4574 ssh->state = SSH_STATE_INTERMED;
4578 if (pktin->type != SSH1_SMSG_SUCCESS
4579 && pktin->type != SSH1_SMSG_FAILURE) {
4580 bombout(("Protocol confusion"));
4582 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4583 c_write_str(ssh, "Server refused to allocate pty\r\n");
4584 ssh->editing = ssh->echoing = 1;
4586 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
4587 ssh->ospeed, ssh->ispeed);
4589 ssh->editing = ssh->echoing = 1;
4592 if (ssh->cfg.compression) {
4593 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
4597 if (pktin->type != SSH1_SMSG_SUCCESS
4598 && pktin->type != SSH1_SMSG_FAILURE) {
4599 bombout(("Protocol confusion"));
4601 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4602 c_write_str(ssh, "Server refused to compress\r\n");
4604 logevent("Started compression");
4605 ssh->v1_compressing = TRUE;
4606 ssh->cs_comp_ctx = zlib_compress_init();
4607 logevent("Initialised zlib (RFC1950) compression");
4608 ssh->sc_comp_ctx = zlib_decompress_init();
4609 logevent("Initialised zlib (RFC1950) decompression");
4613 * Start the shell or command.
4615 * Special case: if the first-choice command is an SSH2
4616 * subsystem (hence not usable here) and the second choice
4617 * exists, we fall straight back to that.
4620 char *cmd = ssh->cfg.remote_cmd_ptr;
4622 if (!cmd) cmd = ssh->cfg.remote_cmd;
4624 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4625 cmd = ssh->cfg.remote_cmd_ptr2;
4626 ssh->fallback_cmd = TRUE;
4629 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
4631 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
4632 logevent("Started session");
4635 ssh->state = SSH_STATE_SESSION;
4636 if (ssh->size_needed)
4637 ssh_size(ssh, ssh->term_width, ssh->term_height);
4638 if (ssh->eof_needed)
4639 ssh_special(ssh, TS_EOF);
4642 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
4644 ssh->channels = newtree234(ssh_channelcmp);
4648 * By this point, most incoming packets are already being
4649 * handled by the dispatch table, and we need only pay
4650 * attention to the unusual ones.
4655 if (pktin->type == SSH1_SMSG_SUCCESS) {
4656 /* may be from EXEC_SHELL on some servers */
4657 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4658 /* may be from EXEC_SHELL on some servers
4659 * if no pty is available or in other odd cases. Ignore */
4661 bombout(("Strange packet received: type %d", pktin->type));
4666 int len = min(inlen, 512);
4667 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4668 PKT_INT, len, PKT_DATA, in, len,
4669 PKTT_OTHER, PKT_END);
4680 * Handle the top-level SSH2 protocol.
4682 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4687 ssh_pkt_getstring(pktin, &msg, &msglen);
4688 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
4691 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4693 /* log reason code in disconnect message */
4697 ssh_pkt_getstring(pktin, &msg, &msglen);
4698 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4701 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
4703 /* Do nothing, because we're ignoring it! Duhh. */
4706 static void ssh1_protocol_setup(Ssh ssh)
4711 * Most messages are handled by the coroutines.
4713 for (i = 0; i < 256; i++)
4714 ssh->packet_dispatch[i] = NULL;
4717 * These special message types we install handlers for.
4719 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4720 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4721 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4724 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
4725 struct Packet *pktin)
4727 unsigned char *in=(unsigned char*)vin;
4728 if (ssh->state == SSH_STATE_CLOSED)
4731 if (pktin && ssh->packet_dispatch[pktin->type]) {
4732 ssh->packet_dispatch[pktin->type](ssh, pktin);
4736 if (!ssh->protocol_initial_phase_done) {
4737 if (do_ssh1_login(ssh, in, inlen, pktin))
4738 ssh->protocol_initial_phase_done = TRUE;
4743 do_ssh1_connection(ssh, in, inlen, pktin);
4747 * Utility routine for decoding comma-separated strings in KEXINIT.
4749 static int in_commasep_string(char *needle, char *haystack, int haylen)
4752 if (!needle || !haystack) /* protect against null pointers */
4754 needlen = strlen(needle);
4757 * Is it at the start of the string?
4759 if (haylen >= needlen && /* haystack is long enough */
4760 !memcmp(needle, haystack, needlen) && /* initial match */
4761 (haylen == needlen || haystack[needlen] == ',')
4762 /* either , or EOS follows */
4766 * If not, search for the next comma and resume after that.
4767 * If no comma found, terminate.
4769 while (haylen > 0 && *haystack != ',')
4770 haylen--, haystack++;
4773 haylen--, haystack++; /* skip over comma itself */
4778 * Similar routine for checking whether we have the first string in a list.
4780 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
4783 if (!needle || !haystack) /* protect against null pointers */
4785 needlen = strlen(needle);
4787 * Is it at the start of the string?
4789 if (haylen >= needlen && /* haystack is long enough */
4790 !memcmp(needle, haystack, needlen) && /* initial match */
4791 (haylen == needlen || haystack[needlen] == ',')
4792 /* either , or EOS follows */
4800 * SSH2 key creation method.
4802 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4803 unsigned char *sessid, char chr,
4804 unsigned char *keyspace)
4807 /* First 20 bytes. */
4809 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4811 SHA_Bytes(&s, H, 20);
4812 SHA_Bytes(&s, &chr, 1);
4813 SHA_Bytes(&s, sessid, 20);
4814 SHA_Final(&s, keyspace);
4815 /* Next 20 bytes. */
4817 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4819 SHA_Bytes(&s, H, 20);
4820 SHA_Bytes(&s, keyspace, 20);
4821 SHA_Final(&s, keyspace + 20);
4825 * Handle the SSH2 transport layer.
4827 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
4828 struct Packet *pktin)
4830 unsigned char *in = (unsigned char *)vin;
4831 struct do_ssh2_transport_state {
4832 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
4833 Bignum p, g, e, f, K;
4834 int kex_init_value, kex_reply_value;
4835 const struct ssh_mac **maclist;
4837 const struct ssh2_cipher *cscipher_tobe;
4838 const struct ssh2_cipher *sccipher_tobe;
4839 const struct ssh_mac *csmac_tobe;
4840 const struct ssh_mac *scmac_tobe;
4841 const struct ssh_compress *cscomp_tobe;
4842 const struct ssh_compress *sccomp_tobe;
4843 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4844 int hostkeylen, siglen;
4845 void *hkey; /* actual host key */
4846 unsigned char exchange_hash[20];
4847 int n_preferred_kex;
4848 const struct ssh_kex *preferred_kex[KEX_MAX];
4849 int n_preferred_ciphers;
4850 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4851 const struct ssh_compress *preferred_comp;
4852 int got_session_id, activated_authconn;
4853 struct Packet *pktout;
4858 crState(do_ssh2_transport_state);
4860 crBegin(ssh->do_ssh2_transport_crstate);
4862 s->cscipher_tobe = s->sccipher_tobe = NULL;
4863 s->csmac_tobe = s->scmac_tobe = NULL;
4864 s->cscomp_tobe = s->sccomp_tobe = NULL;
4866 s->got_session_id = s->activated_authconn = FALSE;
4869 * Be prepared to work around the buggy MAC problem.
4871 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4872 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
4874 s->maclist = macs, s->nmacs = lenof(macs);
4877 ssh->pkt_ctx &= ~SSH2_PKTCTX_KEX_MASK;
4879 int i, j, commalist_started;
4882 * Set up the preferred key exchange. (NULL => warn below here)
4884 s->n_preferred_kex = 0;
4885 for (i = 0; i < KEX_MAX; i++) {
4886 switch (ssh->cfg.ssh_kexlist[i]) {
4888 s->preferred_kex[s->n_preferred_kex++] =
4889 &ssh_diffiehellman_gex;
4892 s->preferred_kex[s->n_preferred_kex++] =
4893 &ssh_diffiehellman_group14;
4896 s->preferred_kex[s->n_preferred_kex++] =
4897 &ssh_diffiehellman_group1;
4900 /* Flag for later. Don't bother if it's the last in
4902 if (i < KEX_MAX - 1) {
4903 s->preferred_kex[s->n_preferred_kex++] = NULL;
4910 * Set up the preferred ciphers. (NULL => warn below here)
4912 s->n_preferred_ciphers = 0;
4913 for (i = 0; i < CIPHER_MAX; i++) {
4914 switch (ssh->cfg.ssh_cipherlist[i]) {
4915 case CIPHER_BLOWFISH:
4916 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
4919 if (ssh->cfg.ssh2_des_cbc) {
4920 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
4924 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
4927 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
4930 /* Flag for later. Don't bother if it's the last in
4932 if (i < CIPHER_MAX - 1) {
4933 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
4940 * Set up preferred compression.
4942 if (ssh->cfg.compression)
4943 s->preferred_comp = &ssh_zlib;
4945 s->preferred_comp = &ssh_comp_none;
4948 * Enable queueing of outgoing auth- or connection-layer
4949 * packets while we are in the middle of a key exchange.
4951 ssh->queueing = TRUE;
4954 * Flag that KEX is in progress.
4956 ssh->kex_in_progress = TRUE;
4959 * Construct and send our key exchange packet.
4961 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
4962 for (i = 0; i < 16; i++)
4963 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
4964 /* List key exchange algorithms. */
4965 ssh2_pkt_addstring_start(s->pktout);
4966 commalist_started = 0;
4967 for (i = 0; i < s->n_preferred_kex; i++) {
4968 const struct ssh_kex *k = s->preferred_kex[i];
4969 if (!k) continue; /* warning flag */
4970 if (commalist_started)
4971 ssh2_pkt_addstring_str(s->pktout, ",");
4972 ssh2_pkt_addstring_str(s->pktout, s->preferred_kex[i]->name);
4973 commalist_started = 1;
4975 /* List server host key algorithms. */
4976 ssh2_pkt_addstring_start(s->pktout);
4977 for (i = 0; i < lenof(hostkey_algs); i++) {
4978 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
4979 if (i < lenof(hostkey_algs) - 1)
4980 ssh2_pkt_addstring_str(s->pktout, ",");
4982 /* List client->server encryption algorithms. */
4983 ssh2_pkt_addstring_start(s->pktout);
4984 commalist_started = 0;
4985 for (i = 0; i < s->n_preferred_ciphers; i++) {
4986 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4987 if (!c) continue; /* warning flag */
4988 for (j = 0; j < c->nciphers; j++) {
4989 if (commalist_started)
4990 ssh2_pkt_addstring_str(s->pktout, ",");
4991 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
4992 commalist_started = 1;
4995 /* List server->client encryption algorithms. */
4996 ssh2_pkt_addstring_start(s->pktout);
4997 commalist_started = 0;
4998 for (i = 0; i < s->n_preferred_ciphers; i++) {
4999 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5000 if (!c) continue; /* warning flag */
5001 for (j = 0; j < c->nciphers; j++) {
5002 if (commalist_started)
5003 ssh2_pkt_addstring_str(s->pktout, ",");
5004 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5005 commalist_started = 1;
5008 /* List client->server MAC algorithms. */
5009 ssh2_pkt_addstring_start(s->pktout);
5010 for (i = 0; i < s->nmacs; i++) {
5011 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5012 if (i < s->nmacs - 1)
5013 ssh2_pkt_addstring_str(s->pktout, ",");
5015 /* List server->client MAC algorithms. */
5016 ssh2_pkt_addstring_start(s->pktout);
5017 for (i = 0; i < s->nmacs; i++) {
5018 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5019 if (i < s->nmacs - 1)
5020 ssh2_pkt_addstring_str(s->pktout, ",");
5022 /* List client->server compression algorithms. */
5023 ssh2_pkt_addstring_start(s->pktout);
5024 assert(lenof(compressions) > 1);
5025 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5026 for (i = 0; i < lenof(compressions); i++) {
5027 const struct ssh_compress *c = compressions[i];
5028 if (c != s->preferred_comp) {
5029 ssh2_pkt_addstring_str(s->pktout, ",");
5030 ssh2_pkt_addstring_str(s->pktout, c->name);
5033 /* List server->client compression algorithms. */
5034 ssh2_pkt_addstring_start(s->pktout);
5035 assert(lenof(compressions) > 1);
5036 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5037 for (i = 0; i < lenof(compressions); i++) {
5038 const struct ssh_compress *c = compressions[i];
5039 if (c != s->preferred_comp) {
5040 ssh2_pkt_addstring_str(s->pktout, ",");
5041 ssh2_pkt_addstring_str(s->pktout, c->name);
5044 /* List client->server languages. Empty list. */
5045 ssh2_pkt_addstring_start(s->pktout);
5046 /* List server->client languages. Empty list. */
5047 ssh2_pkt_addstring_start(s->pktout);
5048 /* First KEX packet does _not_ follow, because we're not that brave. */
5049 ssh2_pkt_addbool(s->pktout, FALSE);
5051 ssh2_pkt_adduint32(s->pktout, 0);
5054 ssh->exhash = ssh->exhashbase;
5055 sha_string(&ssh->exhash, s->pktout->data + 5, s->pktout->length - 5);
5057 ssh2_pkt_send_noqueue(ssh, s->pktout);
5061 if (pktin->length > 5)
5062 sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5);
5065 * Now examine the other side's KEXINIT to see what we're up
5069 char *str, *preferred;
5072 if (pktin->type != SSH2_MSG_KEXINIT) {
5073 bombout(("expected key exchange packet from server"));
5077 ssh->hostkey = NULL;
5078 s->cscipher_tobe = NULL;
5079 s->sccipher_tobe = NULL;
5080 s->csmac_tobe = NULL;
5081 s->scmac_tobe = NULL;
5082 s->cscomp_tobe = NULL;
5083 s->sccomp_tobe = NULL;
5084 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
5086 pktin->savedpos += 16; /* skip garbage cookie */
5087 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
5090 for (i = 0; i < s->n_preferred_kex; i++) {
5091 const struct ssh_kex *k = s->preferred_kex[i];
5095 if (!preferred) preferred = k->name;
5096 if (in_commasep_string(k->name, str, len))
5103 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5104 str ? str : "(null)"));
5108 * Note that the server's guess is considered wrong if it doesn't match
5109 * the first algorithm in our list, even if it's still the algorithm
5112 s->guessok = first_in_commasep_string(preferred, str, len);
5113 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
5114 for (i = 0; i < lenof(hostkey_algs); i++) {
5115 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5116 ssh->hostkey = hostkey_algs[i];
5120 s->guessok = s->guessok &&
5121 first_in_commasep_string(hostkey_algs[0]->name, str, len);
5122 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
5123 for (i = 0; i < s->n_preferred_ciphers; i++) {
5124 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5126 s->warn_cscipher = TRUE;
5128 for (j = 0; j < c->nciphers; j++) {
5129 if (in_commasep_string(c->list[j]->name, str, len)) {
5130 s->cscipher_tobe = c->list[j];
5135 if (s->cscipher_tobe)
5138 if (!s->cscipher_tobe) {
5139 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
5140 str ? str : "(null)"));
5144 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
5145 for (i = 0; i < s->n_preferred_ciphers; i++) {
5146 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5148 s->warn_sccipher = TRUE;
5150 for (j = 0; j < c->nciphers; j++) {
5151 if (in_commasep_string(c->list[j]->name, str, len)) {
5152 s->sccipher_tobe = c->list[j];
5157 if (s->sccipher_tobe)
5160 if (!s->sccipher_tobe) {
5161 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
5162 str ? str : "(null)"));
5166 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
5167 for (i = 0; i < s->nmacs; i++) {
5168 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5169 s->csmac_tobe = s->maclist[i];
5173 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
5174 for (i = 0; i < s->nmacs; i++) {
5175 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5176 s->scmac_tobe = s->maclist[i];
5180 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
5181 for (i = 0; i < lenof(compressions) + 1; i++) {
5182 const struct ssh_compress *c =
5183 i == 0 ? s->preferred_comp : compressions[i - 1];
5184 if (in_commasep_string(c->name, str, len)) {
5189 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
5190 for (i = 0; i < lenof(compressions) + 1; i++) {
5191 const struct ssh_compress *c =
5192 i == 0 ? s->preferred_comp : compressions[i - 1];
5193 if (in_commasep_string(c->name, str, len)) {
5198 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5199 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
5200 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
5203 ssh_set_frozen(ssh, 1);
5204 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
5206 ssh_dialog_callback, ssh);
5207 if (s->dlgret < 0) {
5211 bombout(("Unexpected data from server while"
5212 " waiting for user response"));
5215 } while (pktin || inlen > 0);
5216 s->dlgret = ssh->user_response;
5218 ssh_set_frozen(ssh, 0);
5219 if (s->dlgret == 0) {
5220 ssh->close_expected = TRUE;
5221 ssh_closing((Plug)ssh, NULL, 0, 0);
5225 if (s->warn_cscipher) {
5226 ssh_set_frozen(ssh, 1);
5227 s->dlgret = askalg(ssh->frontend,
5228 "client-to-server cipher",
5229 s->cscipher_tobe->name,
5230 ssh_dialog_callback, ssh);
5231 if (s->dlgret < 0) {
5235 bombout(("Unexpected data from server while"
5236 " waiting for user response"));
5239 } while (pktin || inlen > 0);
5240 s->dlgret = ssh->user_response;
5242 ssh_set_frozen(ssh, 0);
5243 if (s->dlgret == 0) {
5244 ssh->close_expected = TRUE;
5245 ssh_closing((Plug)ssh, NULL, 0, 0);
5249 if (s->warn_sccipher) {
5250 ssh_set_frozen(ssh, 1);
5251 s->dlgret = askalg(ssh->frontend,
5252 "server-to-client cipher",
5253 s->sccipher_tobe->name,
5254 ssh_dialog_callback, ssh);
5255 if (s->dlgret < 0) {
5259 bombout(("Unexpected data from server while"
5260 " waiting for user response"));
5263 } while (pktin || inlen > 0);
5264 s->dlgret = ssh->user_response;
5266 ssh_set_frozen(ssh, 0);
5267 if (s->dlgret == 0) {
5268 ssh->close_expected = TRUE;
5269 ssh_closing((Plug)ssh, NULL, 0, 0);
5273 if (s->ignorepkt) /* first_kex_packet_follows */
5274 crWaitUntil(pktin); /* Ignore packet */
5278 * Work out the number of bits of key we will need from the key
5279 * exchange. We start with the maximum key length of either
5285 csbits = s->cscipher_tobe->keylen;
5286 scbits = s->sccipher_tobe->keylen;
5287 s->nbits = (csbits > scbits ? csbits : scbits);
5289 /* The keys only have 160-bit entropy, since they're based on
5290 * a SHA-1 hash. So cap the key size at 160 bits. */
5295 * If we're doing Diffie-Hellman group exchange, start by
5296 * requesting a group.
5298 if (!ssh->kex->pdata) {
5299 logevent("Doing Diffie-Hellman group exchange");
5300 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
5302 * Work out how big a DH group we will need to allow that
5305 s->pbits = 512 << ((s->nbits - 1) / 64);
5306 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5307 ssh2_pkt_adduint32(s->pktout, s->pbits);
5308 ssh2_pkt_send_noqueue(ssh, s->pktout);
5311 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
5312 bombout(("expected key exchange group packet from server"));
5315 s->p = ssh2_pkt_getmp(pktin);
5316 s->g = ssh2_pkt_getmp(pktin);
5317 if (!s->p || !s->g) {
5318 bombout(("unable to read mp-ints from incoming group packet"));
5321 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
5322 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5323 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
5325 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP;
5326 ssh->kex_ctx = dh_setup_group(ssh->kex);
5327 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5328 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
5329 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5330 ssh->kex->groupname);
5333 logevent("Doing Diffie-Hellman key exchange");
5335 * Now generate and send e for Diffie-Hellman.
5337 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
5338 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
5339 s->pktout = ssh2_pkt_init(s->kex_init_value);
5340 ssh2_pkt_addmp(s->pktout, s->e);
5341 ssh2_pkt_send_noqueue(ssh, s->pktout);
5343 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
5345 if (pktin->type != s->kex_reply_value) {
5346 bombout(("expected key exchange reply packet from server"));
5349 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
5350 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5351 s->f = ssh2_pkt_getmp(pktin);
5353 bombout(("unable to parse key exchange reply packet"));
5356 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
5358 s->K = dh_find_K(ssh->kex_ctx, s->f);
5360 /* We assume everything from now on will be quick, and it might
5361 * involve user interaction. */
5362 set_busy_status(ssh->frontend, BUSY_NOT);
5364 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
5365 if (ssh->kex == &ssh_diffiehellman_gex) {
5366 sha_uint32(&ssh->exhash, s->pbits);
5367 sha_mpint(&ssh->exhash, s->p);
5368 sha_mpint(&ssh->exhash, s->g);
5370 sha_mpint(&ssh->exhash, s->e);
5371 sha_mpint(&ssh->exhash, s->f);
5372 sha_mpint(&ssh->exhash, s->K);
5373 SHA_Final(&ssh->exhash, s->exchange_hash);
5375 dh_cleanup(ssh->kex_ctx);
5376 ssh->kex_ctx = NULL;
5379 debug(("Exchange hash is:\n"));
5380 dmemdump(s->exchange_hash, 20);
5383 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5385 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
5386 (char *)s->exchange_hash, 20)) {
5387 bombout(("Server's host key did not match the signature supplied"));
5392 * Authenticate remote host: verify host key. (We've already
5393 * checked the signature of the exchange hash.)
5395 s->keystr = ssh->hostkey->fmtkey(s->hkey);
5396 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
5397 ssh_set_frozen(ssh, 1);
5398 s->dlgret = verify_ssh_host_key(ssh->frontend,
5399 ssh->savedhost, ssh->savedport,
5400 ssh->hostkey->keytype, s->keystr,
5402 ssh_dialog_callback, ssh);
5403 if (s->dlgret < 0) {
5407 bombout(("Unexpected data from server while waiting"
5408 " for user host key response"));
5411 } while (pktin || inlen > 0);
5412 s->dlgret = ssh->user_response;
5414 ssh_set_frozen(ssh, 0);
5415 if (s->dlgret == 0) {
5416 ssh->close_expected = TRUE;
5417 ssh_closing((Plug)ssh, NULL, 0, 0);
5420 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5421 logevent("Host key fingerprint is:");
5422 logevent(s->fingerprint);
5424 sfree(s->fingerprint);
5426 ssh->hostkey->freekey(s->hkey);
5429 * The exchange hash from the very first key exchange is also
5430 * the session id, used in session key construction and
5433 if (!s->got_session_id) {
5434 memcpy(ssh->v2_session_id, s->exchange_hash,
5435 sizeof(s->exchange_hash));
5436 s->got_session_id = TRUE;
5440 * Send SSH2_MSG_NEWKEYS.
5442 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
5443 ssh2_pkt_send_noqueue(ssh, s->pktout);
5444 ssh->outgoing_data_size = 0; /* start counting from here */
5447 * We've sent client NEWKEYS, so create and initialise
5448 * client-to-server session keys.
5450 if (ssh->cs_cipher_ctx)
5451 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
5452 ssh->cscipher = s->cscipher_tobe;
5453 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
5455 if (ssh->cs_mac_ctx)
5456 ssh->csmac->free_context(ssh->cs_mac_ctx);
5457 ssh->csmac = s->csmac_tobe;
5458 ssh->cs_mac_ctx = ssh->csmac->make_context();
5460 if (ssh->cs_comp_ctx)
5461 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
5462 ssh->cscomp = s->cscomp_tobe;
5463 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
5466 * Set IVs on client-to-server keys. Here we use the exchange
5467 * hash from the _first_ key exchange.
5470 unsigned char keyspace[40];
5471 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
5472 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
5473 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
5474 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
5475 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
5476 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
5479 logeventf(ssh, "Initialised %.200s client->server encryption",
5480 ssh->cscipher->text_name);
5481 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
5482 ssh->csmac->text_name);
5483 if (ssh->cscomp->text_name)
5484 logeventf(ssh, "Initialised %s compression",
5485 ssh->cscomp->text_name);
5488 * Now our end of the key exchange is complete, we can send all
5489 * our queued higher-layer packets.
5491 ssh->queueing = FALSE;
5492 ssh2_pkt_queuesend(ssh);
5495 * Expect SSH2_MSG_NEWKEYS from server.
5498 if (pktin->type != SSH2_MSG_NEWKEYS) {
5499 bombout(("expected new-keys packet from server"));
5502 ssh->incoming_data_size = 0; /* start counting from here */
5505 * We've seen server NEWKEYS, so create and initialise
5506 * server-to-client session keys.
5508 if (ssh->sc_cipher_ctx)
5509 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
5510 ssh->sccipher = s->sccipher_tobe;
5511 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
5513 if (ssh->sc_mac_ctx)
5514 ssh->scmac->free_context(ssh->sc_mac_ctx);
5515 ssh->scmac = s->scmac_tobe;
5516 ssh->sc_mac_ctx = ssh->scmac->make_context();
5518 if (ssh->sc_comp_ctx)
5519 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
5520 ssh->sccomp = s->sccomp_tobe;
5521 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
5524 * Set IVs on server-to-client keys. Here we use the exchange
5525 * hash from the _first_ key exchange.
5528 unsigned char keyspace[40];
5529 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
5530 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
5531 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
5532 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
5533 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
5534 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
5536 logeventf(ssh, "Initialised %.200s server->client encryption",
5537 ssh->sccipher->text_name);
5538 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
5539 ssh->scmac->text_name);
5540 if (ssh->sccomp->text_name)
5541 logeventf(ssh, "Initialised %s decompression",
5542 ssh->sccomp->text_name);
5545 * Free key exchange data.
5549 if (ssh->kex == &ssh_diffiehellman_gex) {
5555 * Key exchange is over. Loop straight back round if we have a
5556 * deferred rekey reason.
5558 if (ssh->deferred_rekey_reason) {
5559 logevent(ssh->deferred_rekey_reason);
5561 ssh->deferred_rekey_reason = NULL;
5562 goto begin_key_exchange;
5566 * Otherwise, schedule a timer for our next rekey.
5568 ssh->kex_in_progress = FALSE;
5569 ssh->last_rekey = GETTICKCOUNT();
5570 if (ssh->cfg.ssh_rekey_time != 0)
5571 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5575 * If this is the first key exchange phase, we must pass the
5576 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
5577 * wants to see it but because it will need time to initialise
5578 * itself before it sees an actual packet. In subsequent key
5579 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
5580 * it would only confuse the layer above.
5582 if (s->activated_authconn) {
5585 s->activated_authconn = TRUE;
5588 * Now we're encrypting. Begin returning 1 to the protocol main
5589 * function so that other things can run on top of the
5590 * transport. If we ever see a KEXINIT, we must go back to the
5593 * We _also_ go back to the start if we see pktin==NULL and
5594 * inlen==-1, because this is a special signal meaning
5595 * `initiate client-driven rekey', and `in' contains a message
5596 * giving the reason for the rekey.
5598 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
5599 (!pktin && inlen == -1))) {
5604 logevent("Server initiated key re-exchange");
5607 * Special case: if the server bug is set that doesn't
5608 * allow rekeying, we give a different log message and
5609 * continue waiting. (If such a server _initiates_ a rekey,
5610 * we process it anyway!)
5612 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
5613 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
5615 /* Reset the counters, so that at least this message doesn't
5616 * hit the event log _too_ often. */
5617 ssh->outgoing_data_size = 0;
5618 ssh->incoming_data_size = 0;
5619 if (ssh->cfg.ssh_rekey_time != 0) {
5621 schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5624 goto wait_for_rekey; /* this is utterly horrid */
5626 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
5629 goto begin_key_exchange;
5635 * Add data to an SSH2 channel output buffer.
5637 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
5640 bufchain_add(&c->v.v2.outbuffer, buf, len);
5644 * Attempt to send data on an SSH2 channel.
5646 static int ssh2_try_send(struct ssh_channel *c)
5649 struct Packet *pktout;
5651 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
5654 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
5655 if ((unsigned)len > c->v.v2.remwindow)
5656 len = c->v.v2.remwindow;
5657 if ((unsigned)len > c->v.v2.remmaxpkt)
5658 len = c->v.v2.remmaxpkt;
5659 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
5660 ssh2_pkt_adduint32(pktout, c->remoteid);
5661 dont_log_data(ssh, pktout, PKTLOG_OMIT);
5662 ssh2_pkt_addstring_start(pktout);
5663 ssh2_pkt_addstring_data(pktout, data, len);
5664 end_log_omission(ssh, pktout);
5665 ssh2_pkt_send(ssh, pktout);
5666 bufchain_consume(&c->v.v2.outbuffer, len);
5667 c->v.v2.remwindow -= len;
5671 * After having sent as much data as we can, return the amount
5674 return bufchain_size(&c->v.v2.outbuffer);
5678 * Potentially enlarge the window on an SSH2 channel.
5680 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
5685 * Never send WINDOW_ADJUST for a channel that the remote side
5686 * already thinks it's closed; there's no point, since it won't
5687 * be sending any more data anyway.
5693 * Only send a WINDOW_ADJUST if there's significantly more window
5694 * available than the other end thinks there is. This saves us
5695 * sending a WINDOW_ADJUST for every character in a shell session.
5697 * "Significant" is arbitrarily defined as half the window size.
5699 if (newwin > c->v.v2.locwindow * 2) {
5700 struct Packet *pktout;
5702 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5703 ssh2_pkt_adduint32(pktout, c->remoteid);
5704 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
5705 ssh2_pkt_send(ssh, pktout);
5706 c->v.v2.locwindow = newwin;
5710 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
5712 unsigned i = ssh_pkt_getuint32(pktin);
5713 struct ssh_channel *c;
5714 c = find234(ssh->channels, &i, ssh_channelfind);
5715 if (c && !c->closes)
5716 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
5719 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
5723 unsigned i = ssh_pkt_getuint32(pktin);
5724 struct ssh_channel *c;
5725 c = find234(ssh->channels, &i, ssh_channelfind);
5727 return; /* nonexistent channel */
5728 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5729 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
5730 return; /* extended but not stderr */
5731 ssh_pkt_getstring(pktin, &data, &length);
5734 c->v.v2.locwindow -= length;
5736 case CHAN_MAINSESSION:
5738 from_backend(ssh->frontend, pktin->type ==
5739 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5743 bufsize = x11_send(c->u.x11.s, data, length);
5746 bufsize = pfd_send(c->u.pfd.s, data, length);
5749 while (length > 0) {
5750 if (c->u.a.lensofar < 4) {
5751 unsigned int l = min(4 - c->u.a.lensofar, length);
5752 memcpy(c->u.a.msglen + c->u.a.lensofar,
5756 c->u.a.lensofar += l;
5758 if (c->u.a.lensofar == 4) {
5760 4 + GET_32BIT(c->u.a.msglen);
5761 c->u.a.message = snewn(c->u.a.totallen,
5763 memcpy(c->u.a.message, c->u.a.msglen, 4);
5765 if (c->u.a.lensofar >= 4 && length > 0) {
5767 min(c->u.a.totallen - c->u.a.lensofar,
5769 memcpy(c->u.a.message + c->u.a.lensofar,
5773 c->u.a.lensofar += l;
5775 if (c->u.a.lensofar == c->u.a.totallen) {
5778 if (agent_query(c->u.a.message,
5781 ssh_agentf_callback, c))
5782 ssh_agentf_callback(c, reply, replylen);
5783 sfree(c->u.a.message);
5784 c->u.a.lensofar = 0;
5791 * If we are not buffering too much data,
5792 * enlarge the window again at the remote side.
5794 if (bufsize < OUR_V2_WINSIZE)
5795 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5799 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
5801 unsigned i = ssh_pkt_getuint32(pktin);
5802 struct ssh_channel *c;
5804 c = find234(ssh->channels, &i, ssh_channelfind);
5806 return; /* nonexistent channel */
5808 if (c->type == CHAN_X11) {
5810 * Remote EOF on an X11 channel means we should
5811 * wrap up and close the channel ourselves.
5813 x11_close(c->u.x11.s);
5815 } else if (c->type == CHAN_AGENT) {
5817 } else if (c->type == CHAN_SOCKDATA) {
5818 pfd_close(c->u.pfd.s);
5823 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
5825 unsigned i = ssh_pkt_getuint32(pktin);
5826 struct ssh_channel *c;
5827 struct Packet *pktout;
5829 c = find234(ssh->channels, &i, ssh_channelfind);
5830 if (!c || c->halfopen) {
5831 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5832 c ? "half-open" : "nonexistent", i));
5835 /* Do pre-close processing on the channel. */
5837 case CHAN_MAINSESSION:
5838 ssh->mainchan = NULL;
5839 update_specials_menu(ssh->frontend);
5842 if (c->u.x11.s != NULL)
5843 x11_close(c->u.x11.s);
5850 if (c->u.pfd.s != NULL)
5851 pfd_close(c->u.pfd.s);
5855 if (c->closes == 0) {
5856 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5857 ssh2_pkt_adduint32(pktout, c->remoteid);
5858 ssh2_pkt_send(ssh, pktout);
5860 del234(ssh->channels, c);
5861 bufchain_clear(&c->v.v2.outbuffer);
5865 * See if that was the last channel left open.
5866 * (This is only our termination condition if we're
5867 * not running in -N mode.)
5869 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
5870 logevent("All channels closed. Disconnecting");
5873 * We used to send SSH_MSG_DISCONNECT here,
5874 * because I'd believed that _every_ conforming
5875 * SSH2 connection had to end with a disconnect
5876 * being sent by at least one side; apparently
5877 * I was wrong and it's perfectly OK to
5878 * unceremoniously slam the connection shut
5879 * when you're done, and indeed OpenSSH feels
5880 * this is more polite than sending a
5881 * DISCONNECT. So now we don't.
5883 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5884 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
5885 ssh2_pkt_addstring(s->pktout, "All open channels closed");
5886 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
5887 ssh2_pkt_send_noqueue(ssh, s->pktout);
5889 ssh->close_expected = TRUE;
5890 ssh_closing((Plug)ssh, NULL, 0, 0);
5894 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5896 unsigned i = ssh_pkt_getuint32(pktin);
5897 struct ssh_channel *c;
5898 struct Packet *pktout;
5900 c = find234(ssh->channels, &i, ssh_channelfind);
5902 return; /* nonexistent channel */
5903 if (c->type != CHAN_SOCKDATA_DORMANT)
5904 return; /* dunno why they're confirming this */
5905 c->remoteid = ssh_pkt_getuint32(pktin);
5906 c->halfopen = FALSE;
5907 c->type = CHAN_SOCKDATA;
5908 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
5909 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
5911 pfd_confirm(c->u.pfd.s);
5914 * We have a pending close on this channel,
5915 * which we decided on before the server acked
5916 * the channel open. So now we know the
5917 * remoteid, we can close it again.
5919 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5920 ssh2_pkt_adduint32(pktout, c->remoteid);
5921 ssh2_pkt_send(ssh, pktout);
5925 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5927 static const char *const reasons[] = {
5928 "<unknown reason code>",
5929 "Administratively prohibited",
5931 "Unknown channel type",
5932 "Resource shortage",
5934 unsigned i = ssh_pkt_getuint32(pktin);
5935 unsigned reason_code;
5936 char *reason_string;
5938 struct ssh_channel *c;
5939 c = find234(ssh->channels, &i, ssh_channelfind);
5941 return; /* nonexistent channel */
5942 if (c->type != CHAN_SOCKDATA_DORMANT)
5943 return; /* dunno why they're failing this */
5945 reason_code = ssh_pkt_getuint32(pktin);
5946 if (reason_code >= lenof(reasons))
5947 reason_code = 0; /* ensure reasons[reason_code] in range */
5948 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
5949 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
5950 reasons[reason_code], reason_length, reason_string);
5952 pfd_close(c->u.pfd.s);
5954 del234(ssh->channels, c);
5958 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
5962 int typelen, want_reply;
5963 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
5964 struct ssh_channel *c;
5965 struct Packet *pktout;
5967 localid = ssh_pkt_getuint32(pktin);
5968 ssh_pkt_getstring(pktin, &type, &typelen);
5969 want_reply = ssh2_pkt_getbool(pktin);
5972 * First, check that the channel exists. Otherwise,
5973 * we can instantly disconnect with a rude message.
5975 c = find234(ssh->channels, &localid, ssh_channelfind);
5978 sprintf(buf, "Received channel request for nonexistent"
5979 " channel %d", localid);
5981 pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5982 ssh2_pkt_adduint32(pktout, SSH2_DISCONNECT_BY_APPLICATION);
5983 ssh2_pkt_addstring(pktout, buf);
5984 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5985 ssh2_pkt_send_noqueue(ssh, pktout);
5986 connection_fatal(ssh->frontend, "%s", buf);
5987 ssh->close_expected = TRUE;
5988 ssh_closing((Plug)ssh, NULL, 0, 0);
5993 * Having got the channel number, we now look at
5994 * the request type string to see if it's something
5997 if (c == ssh->mainchan) {
5999 * We recognise "exit-status" and "exit-signal" on
6000 * the primary channel.
6002 if (typelen == 11 &&
6003 !memcmp(type, "exit-status", 11)) {
6005 ssh->exitcode = ssh_pkt_getuint32(pktin);
6006 logeventf(ssh, "Server sent command exit status %d",
6008 reply = SSH2_MSG_CHANNEL_SUCCESS;
6010 } else if (typelen == 11 &&
6011 !memcmp(type, "exit-signal", 11)) {
6013 int is_plausible = TRUE, is_int = FALSE;
6014 char *fmt_sig = "", *fmt_msg = "";
6016 int msglen = 0, core = FALSE;
6017 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
6018 * provide an `int' for the signal, despite its
6019 * having been a `string' in the drafts since at
6020 * least 2001. (Fixed in session.c 1.147.) Try to
6021 * infer which we can safely parse it as. */
6023 unsigned char *p = pktin->body +
6025 long len = pktin->length - pktin->savedpos;
6026 unsigned long num = GET_32BIT(p); /* what is it? */
6027 /* If it's 0, it hardly matters; assume string */
6031 int maybe_int = FALSE, maybe_str = FALSE;
6032 #define CHECK_HYPOTHESIS(offset, result) \
6035 if (q >= 0 && q+4 <= len) { \
6036 q = q + 4 + GET_32BIT(p+q); \
6037 if (q >= 0 && q+4 <= len && \
6038 ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
6042 CHECK_HYPOTHESIS(4+1, maybe_int);
6043 CHECK_HYPOTHESIS(4+num+1, maybe_str);
6044 #undef CHECK_HYPOTHESIS
6045 if (maybe_int && !maybe_str)
6047 else if (!maybe_int && maybe_str)
6050 /* Crikey. Either or neither. Panic. */
6051 is_plausible = FALSE;
6056 /* Old non-standard OpenSSH. */
6057 int signum = ssh_pkt_getuint32(pktin);
6058 fmt_sig = dupprintf(" %d", signum);
6060 /* As per the drafts. */
6063 ssh_pkt_getstring(pktin, &sig, &siglen);
6064 /* Signal name isn't supposed to be blank, but
6065 * let's cope gracefully if it is. */
6067 fmt_sig = dupprintf(" \"%.*s\"",
6071 core = ssh2_pkt_getbool(pktin);
6072 ssh_pkt_getstring(pktin, &msg, &msglen);
6074 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
6076 /* ignore lang tag */
6077 } /* else don't attempt to parse */
6078 logeventf(ssh, "Server exited on signal%s%s%s",
6079 fmt_sig, core ? " (core dumped)" : "",
6081 if (*fmt_sig) sfree(fmt_sig);
6082 if (*fmt_msg) sfree(fmt_msg);
6083 reply = SSH2_MSG_CHANNEL_SUCCESS;
6088 * This is a channel request we don't know
6089 * about, so we now either ignore the request
6090 * or respond with CHANNEL_FAILURE, depending
6093 reply = SSH2_MSG_CHANNEL_FAILURE;
6096 pktout = ssh2_pkt_init(reply);
6097 ssh2_pkt_adduint32(pktout, c->remoteid);
6098 ssh2_pkt_send(ssh, pktout);
6102 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
6105 int typelen, want_reply;
6106 struct Packet *pktout;
6108 ssh_pkt_getstring(pktin, &type, &typelen);
6109 want_reply = ssh2_pkt_getbool(pktin);
6112 * We currently don't support any global requests
6113 * at all, so we either ignore the request or
6114 * respond with REQUEST_FAILURE, depending on
6118 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
6119 ssh2_pkt_send(ssh, pktout);
6123 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
6131 struct ssh_channel *c;
6132 unsigned remid, winsize, pktsize;
6133 struct Packet *pktout;
6135 ssh_pkt_getstring(pktin, &type, &typelen);
6136 c = snew(struct ssh_channel);
6139 remid = ssh_pkt_getuint32(pktin);
6140 winsize = ssh_pkt_getuint32(pktin);
6141 pktsize = ssh_pkt_getuint32(pktin);
6143 if (typelen == 3 && !memcmp(type, "x11", 3)) {
6146 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6147 addrstr = snewn(peeraddrlen+1, char);
6148 memcpy(addrstr, peeraddr, peeraddrlen);
6149 addrstr[peeraddrlen] = '\0';
6150 peerport = ssh_pkt_getuint32(pktin);
6152 logeventf(ssh, "Received X11 connect request from %s:%d",
6155 if (!ssh->X11_fwd_enabled)
6156 error = "X11 forwarding is not enabled";
6157 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
6158 ssh->x11auth, addrstr, peerport,
6159 &ssh->cfg) != NULL) {
6160 error = "Unable to open an X11 connection";
6162 logevent("Opening X11 forward connection succeeded");
6167 } else if (typelen == 15 &&
6168 !memcmp(type, "forwarded-tcpip", 15)) {
6169 struct ssh_rportfwd pf, *realpf;
6172 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
6173 pf.sport = ssh_pkt_getuint32(pktin);
6174 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6175 peerport = ssh_pkt_getuint32(pktin);
6176 realpf = find234(ssh->rportfwds, &pf, NULL);
6177 logeventf(ssh, "Received remote port %d open request "
6178 "from %s:%d", pf.sport, peeraddr, peerport);
6179 if (realpf == NULL) {
6180 error = "Remote port is not recognised";
6182 const char *e = pfd_newconnect(&c->u.pfd.s,
6186 realpf->pfrec->addressfamily);
6187 logeventf(ssh, "Attempting to forward remote port to "
6188 "%s:%d", realpf->dhost, realpf->dport);
6190 logeventf(ssh, "Port open failed: %s", e);
6191 error = "Port open failed";
6193 logevent("Forwarded port opened successfully");
6194 c->type = CHAN_SOCKDATA;
6197 } else if (typelen == 22 &&
6198 !memcmp(type, "auth-agent@openssh.com", 3)) {
6199 if (!ssh->agentfwd_enabled)
6200 error = "Agent forwarding is not enabled";
6202 c->type = CHAN_AGENT; /* identify channel type */
6203 c->u.a.lensofar = 0;
6206 error = "Unsupported channel type requested";
6209 c->remoteid = remid;
6210 c->halfopen = FALSE;
6212 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
6213 ssh2_pkt_adduint32(pktout, c->remoteid);
6214 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
6215 ssh2_pkt_addstring(pktout, error);
6216 ssh2_pkt_addstring(pktout, "en"); /* language tag */
6217 ssh2_pkt_send(ssh, pktout);
6218 logeventf(ssh, "Rejected channel open: %s", error);
6221 c->localid = alloc_channel_id(ssh);
6223 c->v.v2.locwindow = OUR_V2_WINSIZE;
6224 c->v.v2.remwindow = winsize;
6225 c->v.v2.remmaxpkt = pktsize;
6226 bufchain_init(&c->v.v2.outbuffer);
6227 add234(ssh->channels, c);
6228 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
6229 ssh2_pkt_adduint32(pktout, c->remoteid);
6230 ssh2_pkt_adduint32(pktout, c->localid);
6231 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
6232 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
6233 ssh2_pkt_send(ssh, pktout);
6238 * Handle the SSH2 userauth and connection layers.
6240 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
6241 struct Packet *pktin)
6243 struct do_ssh2_authconn_state {
6245 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
6247 AUTH_KEYBOARD_INTERACTIVE
6251 AUTH_TYPE_PUBLICKEY,
6252 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
6253 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
6255 AUTH_TYPE_KEYBOARD_INTERACTIVE,
6256 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
6258 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
6259 int tried_pubkey_config, tried_agent;
6260 int kbd_inter_running, kbd_inter_refused;
6262 int num_prompts, curr_prompt, echo;
6267 void *publickey_blob;
6268 int publickey_bloblen;
6269 unsigned char request[5], *response, *p;
6273 char *pkblob, *alg, *commentp;
6274 int pklen, alglen, commentlen;
6275 int siglen, retlen, len;
6276 char *q, *agentreq, *ret;
6278 int num_env, env_left, env_ok;
6279 struct Packet *pktout;
6281 crState(do_ssh2_authconn_state);
6283 crBegin(ssh->do_ssh2_authconn_crstate);
6286 * Request userauth protocol, and await a response to it.
6288 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6289 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
6290 ssh2_pkt_send(ssh, s->pktout);
6291 crWaitUntilV(pktin);
6292 if (pktin->type != SSH2_MSG_SERVICE_ACCEPT) {
6293 bombout(("Server refused user authentication protocol"));
6298 * We repeat this whole loop, including the username prompt,
6299 * until we manage a successful authentication. If the user
6300 * types the wrong _password_, they can be sent back to the
6301 * beginning to try another username, if this is configured on.
6302 * (If they specify a username in the config, they are never
6303 * asked, even if they do give a wrong password.)
6305 * I think this best serves the needs of
6307 * - the people who have no configuration, no keys, and just
6308 * want to try repeated (username,password) pairs until they
6309 * type both correctly
6311 * - people who have keys and configuration but occasionally
6312 * need to fall back to passwords
6314 * - people with a key held in Pageant, who might not have
6315 * logged in to a particular machine before; so they want to
6316 * type a username, and then _either_ their key will be
6317 * accepted, _or_ they will type a password. If they mistype
6318 * the username they will want to be able to get back and
6321 s->username[0] = '\0';
6322 s->got_username = FALSE;
6327 if (s->got_username && !ssh->cfg.change_username) {
6329 * We got a username last time round this loop, and
6330 * with change_username turned off we don't try to get
6333 } else if (!*ssh->cfg.username) {
6334 if (ssh_get_line && !ssh_getline_pw_only) {
6335 if (!ssh_get_line("login as: ",
6336 s->username, sizeof(s->username), FALSE)) {
6338 * get_line failed to get a username.
6341 logevent("No username provided. Abandoning session.");
6342 ssh->close_expected = TRUE;
6343 ssh_closing((Plug)ssh, NULL, 0, 0);
6347 int ret; /* need not be saved across crReturn */
6348 c_write_str(ssh, "login as: ");
6350 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
6352 crWaitUntilV(!pktin);
6353 ret = process_userpass_input(ssh, in, inlen);
6357 c_write_str(ssh, "\r\n");
6359 s->username[strcspn(s->username, "\n\r")] = '\0';
6362 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
6363 s->username[sizeof(s->username)-1] = '\0';
6364 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
6365 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
6366 c_write_str(ssh, stuff);
6370 s->got_username = TRUE;
6373 * Send an authentication request using method "none": (a)
6374 * just in case it succeeds, and (b) so that we know what
6375 * authentication methods we can usefully try next.
6377 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6379 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6380 ssh2_pkt_addstring(s->pktout, s->username);
6381 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
6382 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6383 ssh2_pkt_send(ssh, s->pktout);
6384 s->type = AUTH_TYPE_NONE;
6386 s->we_are_in = FALSE;
6388 s->tried_pubkey_config = FALSE;
6389 s->tried_agent = FALSE;
6390 s->kbd_inter_running = FALSE;
6391 s->kbd_inter_refused = FALSE;
6392 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
6393 if (!filename_is_null(ssh->cfg.keyfile)) {
6395 logeventf(ssh, "Reading private key file \"%.150s\"",
6396 filename_to_str(&ssh->cfg.keyfile));
6397 keytype = key_type(&ssh->cfg.keyfile);
6398 if (keytype == SSH_KEYTYPE_SSH2) {
6400 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
6401 &s->publickey_bloblen, NULL);
6404 logeventf(ssh, "Unable to use this key file (%s)",
6405 key_type_to_str(keytype));
6406 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6408 filename_to_str(&ssh->cfg.keyfile),
6409 key_type_to_str(keytype));
6410 c_write_str(ssh, msgbuf);
6412 s->publickey_blob = NULL;
6415 s->publickey_blob = NULL;
6419 * Wait for the result of the last authentication request.
6422 crWaitUntilV(pktin);
6423 while (pktin->type == SSH2_MSG_USERAUTH_BANNER) {
6427 * Don't show the banner if we're operating in
6428 * non-verbose non-interactive mode. (It's probably
6429 * a script, which means nobody will read the
6430 * banner _anyway_, and moreover the printing of
6431 * the banner will screw up processing on the
6432 * output of (say) plink.)
6434 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
6435 ssh_pkt_getstring(pktin, &banner, &size);
6437 c_write_untrusted(ssh, banner, size);
6439 crWaitUntilV(pktin);
6441 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
6442 logevent("Access granted");
6443 s->we_are_in = TRUE;
6447 if (s->kbd_inter_running &&
6448 pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
6450 * This is either a further set-of-prompts packet
6451 * in keyboard-interactive authentication, or it's
6452 * the same one and we came back here with `gotit'
6453 * set. In the former case, we must reset the
6454 * curr_prompt variable.
6458 } else if (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
6459 /* FIXME: perhaps we should support this? */
6460 bombout(("PASSWD_CHANGEREQ not yet supported"));
6462 } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
6463 bombout(("Strange packet received during authentication: type %d",
6471 * OK, we're now sitting on a USERAUTH_FAILURE message, so
6472 * we can look at the string in it and know what we can
6473 * helpfully try next.
6475 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
6478 ssh_pkt_getstring(pktin, &methods, &methlen);
6479 s->kbd_inter_running = FALSE;
6480 if (!ssh2_pkt_getbool(pktin)) {
6482 * We have received an unequivocal Access
6483 * Denied. This can translate to a variety of
6486 * - if we'd just tried "none" authentication,
6487 * it's not worth printing anything at all
6489 * - if we'd just tried a public key _offer_,
6490 * the message should be "Server refused our
6491 * key" (or no message at all if the key
6492 * came from Pageant)
6494 * - if we'd just tried anything else, the
6495 * message really should be "Access denied".
6497 * Additionally, if we'd just tried password
6498 * authentication, we should break out of this
6499 * whole loop so as to go back to the username
6500 * prompt (iff we're configured to allow
6501 * username change attempts).
6503 if (s->type == AUTH_TYPE_NONE) {
6505 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
6506 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
6507 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
6508 c_write_str(ssh, "Server refused our key\r\n");
6509 logevent("Server refused public key");
6510 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
6511 /* server declined keyboard-interactive; ignore */
6513 c_write_str(ssh, "Access denied\r\n");
6514 logevent("Access denied");
6515 if (s->type == AUTH_TYPE_PASSWORD &&
6516 ssh->cfg.change_username) {
6517 /* XXX perhaps we should allow
6518 * keyboard-interactive to do this too? */
6519 s->we_are_in = FALSE;
6524 c_write_str(ssh, "Further authentication required\r\n");
6525 logevent("Further authentication required");
6529 in_commasep_string("publickey", methods, methlen);
6531 in_commasep_string("password", methods, methlen);
6532 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
6533 in_commasep_string("keyboard-interactive", methods, methlen);
6537 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6541 * Most password/passphrase prompts will be
6542 * non-echoing, so we set this to 0 by default.
6543 * Exception is that some keyboard-interactive prompts
6544 * can be echoing, in which case we'll set this to 1.
6548 if (!s->method && s->can_pubkey &&
6549 agent_exists() && !s->tried_agent) {
6551 * Attempt public-key authentication using Pageant.
6556 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6557 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6559 s->tried_agent = TRUE;
6561 logevent("Pageant is running. Requesting keys.");
6563 /* Request the keys held by the agent. */
6564 PUT_32BIT(s->request, 1);
6565 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
6566 if (!agent_query(s->request, 5, &r, &s->responselen,
6567 ssh_agent_callback, ssh)) {
6571 bombout(("Unexpected data from server while"
6572 " waiting for agent response"));
6575 } while (pktin || inlen > 0);
6576 r = ssh->agent_response;
6577 s->responselen = ssh->agent_response_len;
6579 s->response = (unsigned char *) r;
6580 if (s->response && s->responselen >= 5 &&
6581 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
6582 s->p = s->response + 5;
6583 s->nkeys = GET_32BIT(s->p);
6585 logeventf(ssh, "Pageant has %d SSH2 keys", s->nkeys);
6586 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
6589 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
6590 s->pklen = GET_32BIT(s->p);
6592 if (s->publickey_blob &&
6593 s->pklen == s->publickey_bloblen &&
6594 !memcmp(s->p, s->publickey_blob,
6595 s->publickey_bloblen)) {
6596 logevent("This key matches configured key file");
6597 s->tried_pubkey_config = 1;
6599 s->pkblob = (char *)s->p;
6601 s->alglen = GET_32BIT(s->pkblob);
6602 s->alg = s->pkblob + 4;
6603 s->commentlen = GET_32BIT(s->p);
6605 s->commentp = (char *)s->p;
6606 s->p += s->commentlen;
6607 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6608 ssh2_pkt_addstring(s->pktout, s->username);
6609 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6610 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6611 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6612 ssh2_pkt_addstring_start(s->pktout);
6613 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6614 ssh2_pkt_addstring_start(s->pktout);
6615 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6616 ssh2_pkt_send(ssh, s->pktout);
6618 crWaitUntilV(pktin);
6619 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6620 logevent("Key refused");
6624 if (flags & FLAG_VERBOSE) {
6625 c_write_str(ssh, "Authenticating with "
6627 c_write(ssh, s->commentp, s->commentlen);
6628 c_write_str(ssh, "\" from agent\r\n");
6632 * Server is willing to accept the key.
6633 * Construct a SIGN_REQUEST.
6635 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6636 ssh2_pkt_addstring(s->pktout, s->username);
6637 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6638 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6639 ssh2_pkt_addbool(s->pktout, TRUE);
6640 ssh2_pkt_addstring_start(s->pktout);
6641 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6642 ssh2_pkt_addstring_start(s->pktout);
6643 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6645 s->siglen = s->pktout->length - 5 + 4 + 20;
6646 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6648 s->len = 1; /* message type */
6649 s->len += 4 + s->pklen; /* key blob */
6650 s->len += 4 + s->siglen; /* data to sign */
6651 s->len += 4; /* flags */
6652 s->agentreq = snewn(4 + s->len, char);
6653 PUT_32BIT(s->agentreq, s->len);
6654 s->q = s->agentreq + 4;
6655 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
6656 PUT_32BIT(s->q, s->pklen);
6658 memcpy(s->q, s->pkblob, s->pklen);
6660 PUT_32BIT(s->q, s->siglen);
6662 /* Now the data to be signed... */
6663 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6664 PUT_32BIT(s->q, 20);
6667 memcpy(s->q, ssh->v2_session_id, 20);
6669 memcpy(s->q, s->pktout->data + 5,
6670 s->pktout->length - 5);
6671 s->q += s->pktout->length - 5;
6672 /* And finally the (zero) flags word. */
6674 if (!agent_query(s->agentreq, s->len + 4,
6676 ssh_agent_callback, ssh)) {
6680 bombout(("Unexpected data from server"
6681 " while waiting for agent"
6685 } while (pktin || inlen > 0);
6686 vret = ssh->agent_response;
6687 s->retlen = ssh->agent_response_len;
6692 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
6693 logevent("Sending Pageant's response");
6694 ssh2_add_sigblob(ssh, s->pktout,
6695 s->pkblob, s->pklen,
6697 GET_32BIT(s->ret + 5));
6698 ssh2_pkt_send(ssh, s->pktout);
6703 ("Pageant failed to answer challenge");
6714 if (!s->method && s->can_pubkey && s->publickey_blob
6715 && !s->tried_pubkey_config) {
6716 unsigned char *pub_blob;
6717 char *algorithm, *comment;
6720 s->tried_pubkey_config = TRUE;
6722 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6723 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6726 * Try the public key supplied in the configuration.
6728 * First, offer the public blob to see if the server is
6729 * willing to accept it.
6732 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
6737 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6738 ssh2_pkt_addstring(s->pktout, s->username);
6739 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6740 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6741 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6742 ssh2_pkt_addstring(s->pktout, algorithm);
6743 ssh2_pkt_addstring_start(s->pktout);
6744 ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob,
6746 ssh2_pkt_send(ssh, s->pktout);
6747 logevent("Offered public key");
6749 crWaitUntilV(pktin);
6750 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6752 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
6753 continue; /* key refused; give up on it */
6756 logevent("Offer of public key accepted");
6758 * Actually attempt a serious authentication using
6761 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
6762 sprintf(s->pwprompt,
6763 "Passphrase for key \"%.100s\": ",
6769 if (flags & FLAG_VERBOSE) {
6770 c_write_str(ssh, "Authenticating with public key \"");
6771 c_write_str(ssh, comment);
6772 c_write_str(ssh, "\"\r\n");
6774 s->method = AUTH_PUBLICKEY_FILE;
6778 if (!s->method && s->can_keyb_inter && !s->kbd_inter_refused &&
6779 !s->kbd_inter_running) {
6780 s->method = AUTH_KEYBOARD_INTERACTIVE;
6781 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6783 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6784 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
6786 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6787 ssh2_pkt_addstring(s->pktout, s->username);
6788 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6789 ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); /* method */
6790 ssh2_pkt_addstring(s->pktout, ""); /* lang */
6791 ssh2_pkt_addstring(s->pktout, "");
6792 ssh2_pkt_send(ssh, s->pktout);
6794 crWaitUntilV(pktin);
6795 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
6796 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
6798 logevent("Keyboard-interactive authentication refused");
6799 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
6800 s->kbd_inter_refused = TRUE; /* don't try it again */
6804 s->kbd_inter_running = TRUE;
6808 if (s->kbd_inter_running) {
6809 s->method = AUTH_KEYBOARD_INTERACTIVE;
6810 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6812 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6813 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
6815 if (s->curr_prompt == 0) {
6817 * We've got a fresh USERAUTH_INFO_REQUEST.
6818 * Display header data, and start going through
6821 char *name, *inst, *lang;
6822 int name_len, inst_len, lang_len;
6824 ssh_pkt_getstring(pktin, &name, &name_len);
6825 ssh_pkt_getstring(pktin, &inst, &inst_len);
6826 ssh_pkt_getstring(pktin, &lang, &lang_len);
6828 c_write_untrusted(ssh, name, name_len);
6829 c_write_str(ssh, "\r\n");
6832 c_write_untrusted(ssh, inst, inst_len);
6833 c_write_str(ssh, "\r\n");
6835 s->num_prompts = ssh_pkt_getuint32(pktin);
6839 * If there are prompts remaining in the packet,
6840 * display one and get a response.
6842 if (s->curr_prompt < s->num_prompts) {
6846 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
6847 if (prompt_len > 0) {
6848 static const char trunc[] = "<prompt truncated>: ";
6849 static const int prlen = sizeof(s->pwprompt) -
6851 if (prompt_len > prlen) {
6852 memcpy(s->pwprompt, prompt, prlen);
6853 strcpy(s->pwprompt + prlen, trunc);
6855 memcpy(s->pwprompt, prompt, prompt_len);
6856 s->pwprompt[prompt_len] = '\0';
6860 "<server failed to send prompt>: ");
6862 s->echo = ssh2_pkt_getbool(pktin);
6868 if (!s->method && s->can_passwd) {
6869 s->method = AUTH_PASSWORD;
6870 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6871 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
6872 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
6879 if (!ssh_get_line(s->pwprompt, s->password,
6880 sizeof(s->password), TRUE)) {
6882 * get_line failed to get a password (for
6883 * example because one was supplied on the
6884 * command line which has already failed to
6887 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6888 ssh2_pkt_adduint32(s->pktout,SSH2_DISCONNECT_BY_APPLICATION);
6889 ssh2_pkt_addstring(s->pktout, "No more passwords available"
6891 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
6892 ssh2_pkt_send_noqueue(ssh, s->pktout);
6893 logevent("Unable to authenticate");
6894 connection_fatal(ssh->frontend,
6895 "Unable to authenticate");
6896 ssh->close_expected = TRUE;
6897 ssh_closing((Plug)ssh, NULL, 0, 0);
6901 int ret; /* need not be saved across crReturn */
6902 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
6905 setup_userpass_input(ssh, s->password,
6906 sizeof(s->password), s->echo);
6908 crWaitUntilV(!pktin);
6909 ret = process_userpass_input(ssh, in, inlen);
6913 c_write_str(ssh, "\r\n");
6917 if (s->method == AUTH_PUBLICKEY_FILE) {
6919 * We have our passphrase. Now try the actual authentication.
6921 struct ssh2_userkey *key;
6922 const char *error = NULL;
6924 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
6926 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
6927 if (key == SSH2_WRONG_PASSPHRASE) {
6928 c_write_str(ssh, "Wrong passphrase\r\n");
6929 s->tried_pubkey_config = FALSE;
6931 c_write_str(ssh, "Unable to load private key (");
6932 c_write_str(ssh, error);
6933 c_write_str(ssh, ")\r\n");
6934 s->tried_pubkey_config = TRUE;
6936 /* Send a spurious AUTH_NONE to return to the top. */
6937 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6938 ssh2_pkt_addstring(s->pktout, s->username);
6939 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6940 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6941 ssh2_pkt_send(ssh, s->pktout);
6942 s->type = AUTH_TYPE_NONE;
6944 unsigned char *pkblob, *sigblob, *sigdata;
6945 int pkblob_len, sigblob_len, sigdata_len;
6949 * We have loaded the private key and the server
6950 * has announced that it's willing to accept it.
6951 * Hallelujah. Generate a signature and send it.
6953 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6954 ssh2_pkt_addstring(s->pktout, s->username);
6955 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6956 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6957 ssh2_pkt_addbool(s->pktout, TRUE);
6958 ssh2_pkt_addstring(s->pktout, key->alg->name);
6959 pkblob = key->alg->public_blob(key->data, &pkblob_len);
6960 ssh2_pkt_addstring_start(s->pktout);
6961 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len);
6964 * The data to be signed is:
6968 * followed by everything so far placed in the
6971 sigdata_len = s->pktout->length - 5 + 4 + 20;
6972 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6974 sigdata = snewn(sigdata_len, unsigned char);
6976 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6977 PUT_32BIT(sigdata+p, 20);
6980 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
6981 memcpy(sigdata+p, s->pktout->data + 5,
6982 s->pktout->length - 5);
6983 p += s->pktout->length - 5;
6984 assert(p == sigdata_len);
6985 sigblob = key->alg->sign(key->data, (char *)sigdata,
6986 sigdata_len, &sigblob_len);
6987 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
6988 sigblob, sigblob_len);
6993 ssh2_pkt_send(ssh, s->pktout);
6994 s->type = AUTH_TYPE_PUBLICKEY;
6995 key->alg->freekey(key->data);
6997 } else if (s->method == AUTH_PASSWORD) {
6999 * We pad out the password packet to 256 bytes to make
7000 * it harder for an attacker to find the length of the
7003 * Anyone using a password longer than 256 bytes
7004 * probably doesn't have much to worry about from
7005 * people who find out how long their password is!
7007 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7008 s->pktout->forcepad = 256;
7009 ssh2_pkt_addstring(s->pktout, s->username);
7010 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
7011 ssh2_pkt_addstring(s->pktout, "password");
7012 ssh2_pkt_addbool(s->pktout, FALSE);
7013 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7014 ssh2_pkt_addstring(s->pktout, s->password);
7015 memset(s->password, 0, sizeof(s->password));
7016 end_log_omission(ssh, s->pktout);
7017 ssh2_pkt_send(ssh, s->pktout);
7018 logevent("Sent password");
7019 s->type = AUTH_TYPE_PASSWORD;
7020 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
7021 if (s->curr_prompt == 0) {
7022 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
7023 s->pktout->forcepad = 256;
7024 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
7026 if (s->need_pw) { /* only add pw if we just got one! */
7027 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7028 ssh2_pkt_addstring(s->pktout, s->password);
7029 memset(s->password, 0, sizeof(s->password));
7030 end_log_omission(ssh, s->pktout);
7033 if (s->curr_prompt >= s->num_prompts) {
7034 ssh2_pkt_send(ssh, s->pktout);
7037 * If there are prompts remaining, we set
7038 * `gotit' so that we won't attempt to get
7039 * another packet. Then we go back round the
7040 * loop and will end up retrieving another
7041 * prompt out of the existing packet. Funky or
7046 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
7048 c_write_str(ssh, "No supported authentication methods"
7049 " left to try!\r\n");
7050 logevent("No supported authentications offered."
7052 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
7053 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
7054 ssh2_pkt_addstring(s->pktout, "No supported authentication"
7055 " methods available");
7056 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
7057 ssh2_pkt_send_noqueue(ssh, s->pktout);
7058 ssh->close_expected = TRUE;
7059 ssh_closing((Plug)ssh, NULL, 0, 0);
7063 } while (!s->we_are_in);
7066 * Now we're authenticated for the connection protocol. The
7067 * connection protocol will automatically have started at this
7068 * point; there's no need to send SERVICE_REQUEST.
7071 ssh->channels = newtree234(ssh_channelcmp);
7074 * Set up handlers for some connection protocol messages, so we
7075 * don't have to handle them repeatedly in this coroutine.
7077 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
7078 ssh2_msg_channel_window_adjust;
7079 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
7080 ssh2_msg_global_request;
7083 * Create the main session channel.
7085 if (!ssh->cfg.ssh_no_shell) {
7086 ssh->mainchan = snew(struct ssh_channel);
7087 ssh->mainchan->ssh = ssh;
7088 ssh->mainchan->localid = alloc_channel_id(ssh);
7089 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7090 ssh2_pkt_addstring(s->pktout, "session");
7091 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
7092 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
7093 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
7094 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
7095 ssh2_pkt_send(ssh, s->pktout);
7096 crWaitUntilV(pktin);
7097 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
7098 bombout(("Server refused to open a session"));
7100 /* FIXME: error data comes back in FAILURE packet */
7102 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
7103 bombout(("Server's channel confirmation cited wrong channel"));
7106 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
7107 ssh->mainchan->halfopen = FALSE;
7108 ssh->mainchan->type = CHAN_MAINSESSION;
7109 ssh->mainchan->closes = 0;
7110 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7111 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7112 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
7113 add234(ssh->channels, ssh->mainchan);
7114 update_specials_menu(ssh->frontend);
7115 logevent("Opened channel for session");
7117 ssh->mainchan = NULL;
7120 * Now we have a channel, make dispatch table entries for
7121 * general channel-based messages.
7123 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
7124 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
7125 ssh2_msg_channel_data;
7126 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
7127 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
7128 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
7129 ssh2_msg_channel_open_confirmation;
7130 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
7131 ssh2_msg_channel_open_failure;
7132 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
7133 ssh2_msg_channel_request;
7134 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
7135 ssh2_msg_channel_open;
7138 * Potentially enable X11 forwarding.
7140 if (ssh->mainchan && ssh->cfg.x11_forward) {
7141 char proto[20], data[64];
7142 logevent("Requesting X11 forwarding");
7143 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
7144 data, sizeof(data), ssh->cfg.x11_auth);
7145 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
7146 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7147 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7148 ssh2_pkt_addstring(s->pktout, "x11-req");
7149 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7150 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
7151 ssh2_pkt_addstring(s->pktout, proto);
7152 ssh2_pkt_addstring(s->pktout, data);
7153 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
7154 ssh2_pkt_send(ssh, s->pktout);
7156 crWaitUntilV(pktin);
7158 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7159 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7160 bombout(("Unexpected response to X11 forwarding request:"
7161 " packet type %d", pktin->type));
7164 logevent("X11 forwarding refused");
7166 logevent("X11 forwarding enabled");
7167 ssh->X11_fwd_enabled = TRUE;
7172 * Enable port forwardings.
7174 ssh_setup_portfwd(ssh, &ssh->cfg);
7177 * Potentially enable agent forwarding.
7179 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
7180 logevent("Requesting OpenSSH-style agent forwarding");
7181 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7182 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7183 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
7184 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7185 ssh2_pkt_send(ssh, s->pktout);
7187 crWaitUntilV(pktin);
7189 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7190 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7191 bombout(("Unexpected response to agent forwarding request:"
7192 " packet type %d", pktin->type));
7195 logevent("Agent forwarding refused");
7197 logevent("Agent forwarding enabled");
7198 ssh->agentfwd_enabled = TRUE;
7203 * Now allocate a pty for the session.
7205 if (ssh->mainchan && !ssh->cfg.nopty) {
7206 /* Unpick the terminal-speed string. */
7207 /* XXX perhaps we should allow no speeds to be sent. */
7208 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
7209 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
7210 /* Build the pty request. */
7211 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7212 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
7213 ssh2_pkt_addstring(s->pktout, "pty-req");
7214 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7215 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
7216 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
7217 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
7218 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
7219 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
7220 ssh2_pkt_addstring_start(s->pktout);
7221 ssh2_pkt_addbyte(s->pktout, 128); /* TTY_OP_ISPEED */
7222 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
7223 ssh2_pkt_addbyte(s->pktout, 129); /* TTY_OP_OSPEED */
7224 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
7225 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
7226 ssh2_pkt_send(ssh, s->pktout);
7227 ssh->state = SSH_STATE_INTERMED;
7229 crWaitUntilV(pktin);
7231 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7232 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7233 bombout(("Unexpected response to pty request:"
7234 " packet type %d", pktin->type));
7237 c_write_str(ssh, "Server refused to allocate pty\r\n");
7238 ssh->editing = ssh->echoing = 1;
7240 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
7241 ssh->ospeed, ssh->ispeed);
7244 ssh->editing = ssh->echoing = 1;
7248 * Send environment variables.
7250 * Simplest thing here is to send all the requests at once, and
7251 * then wait for a whole bunch of successes or failures.
7253 if (ssh->mainchan && *ssh->cfg.environmt) {
7254 char *e = ssh->cfg.environmt;
7255 char *var, *varend, *val;
7261 while (*e && *e != '\t') e++;
7263 if (*e == '\t') e++;
7268 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7269 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7270 ssh2_pkt_addstring(s->pktout, "env");
7271 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7272 ssh2_pkt_addstring_start(s->pktout);
7273 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
7274 ssh2_pkt_addstring(s->pktout, val);
7275 ssh2_pkt_send(ssh, s->pktout);
7280 logeventf(ssh, "Sent %d environment variables", s->num_env);
7283 s->env_left = s->num_env;
7285 while (s->env_left > 0) {
7286 crWaitUntilV(pktin);
7288 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7289 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7290 bombout(("Unexpected response to environment request:"
7291 " packet type %d", pktin->type));
7301 if (s->env_ok == s->num_env) {
7302 logevent("All environment variables successfully set");
7303 } else if (s->env_ok == 0) {
7304 logevent("All environment variables refused");
7305 c_write_str(ssh, "Server refused to set environment variables\r\n");
7307 logeventf(ssh, "%d environment variables refused",
7308 s->num_env - s->env_ok);
7309 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7314 * Start a shell or a remote command. We may have to attempt
7315 * this twice if the config data has provided a second choice
7318 if (ssh->mainchan) while (1) {
7322 if (ssh->fallback_cmd) {
7323 subsys = ssh->cfg.ssh_subsys2;
7324 cmd = ssh->cfg.remote_cmd_ptr2;
7326 subsys = ssh->cfg.ssh_subsys;
7327 cmd = ssh->cfg.remote_cmd_ptr;
7328 if (!cmd) cmd = ssh->cfg.remote_cmd;
7331 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7332 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
7334 ssh2_pkt_addstring(s->pktout, "subsystem");
7335 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7336 ssh2_pkt_addstring(s->pktout, cmd);
7338 ssh2_pkt_addstring(s->pktout, "exec");
7339 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7340 ssh2_pkt_addstring(s->pktout, cmd);
7342 ssh2_pkt_addstring(s->pktout, "shell");
7343 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7345 ssh2_pkt_send(ssh, s->pktout);
7347 crWaitUntilV(pktin);
7349 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7350 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7351 bombout(("Unexpected response to shell/command request:"
7352 " packet type %d", pktin->type));
7356 * We failed to start the command. If this is the
7357 * fallback command, we really are finished; if it's
7358 * not, and if the fallback command exists, try falling
7359 * back to it before complaining.
7361 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
7362 logevent("Primary command failed; attempting fallback");
7363 ssh->fallback_cmd = TRUE;
7366 bombout(("Server refused to start a shell/command"));
7369 logevent("Started a shell/command");
7374 ssh->state = SSH_STATE_SESSION;
7375 if (ssh->size_needed)
7376 ssh_size(ssh, ssh->term_width, ssh->term_height);
7377 if (ssh->eof_needed)
7378 ssh_special(ssh, TS_EOF);
7384 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
7389 s->try_send = FALSE;
7393 * _All_ the connection-layer packets we expect to
7394 * receive are now handled by the dispatch table.
7395 * Anything that reaches here must be bogus.
7398 bombout(("Strange packet received: type %d", pktin->type));
7400 } else if (ssh->mainchan) {
7402 * We have spare data. Add it to the channel buffer.
7404 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
7409 struct ssh_channel *c;
7411 * Try to send data on all channels if we can.
7413 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
7416 continue; /* don't send on closing channels */
7417 bufsize = ssh2_try_send(c);
7420 case CHAN_MAINSESSION:
7421 /* stdin need not receive an unthrottle
7422 * notification since it will be polled */
7425 x11_unthrottle(c->u.x11.s);
7428 /* agent sockets are request/response and need no
7429 * buffer management */
7432 pfd_unthrottle(c->u.pfd.s);
7444 * Handlers for SSH2 messages that might arrive at any moment.
7446 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
7448 /* log reason code in disconnect message */
7450 int nowlen, reason, msglen;
7452 reason = ssh_pkt_getuint32(pktin);
7453 ssh_pkt_getstring(pktin, &msg, &msglen);
7455 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
7456 buf = dupprintf("Received disconnect message (%s)",
7457 ssh2_disconnect_reasons[reason]);
7459 buf = dupprintf("Received disconnect message (unknown"
7460 " type %d)", reason);
7464 buf = dupprintf("Disconnection message text: %n%.*s",
7465 &nowlen, msglen, msg);
7467 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
7469 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
7470 ssh2_disconnect_reasons[reason] : "unknown",
7475 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
7477 /* log the debug message */
7482 /* XXX maybe we should actually take notice of this */
7483 always_display = ssh2_pkt_getbool(pktin);
7484 ssh_pkt_getstring(pktin, &msg, &msglen);
7486 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
7489 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
7491 struct Packet *pktout;
7492 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
7493 ssh2_pkt_adduint32(pktout, pktin->sequence);
7495 * UNIMPLEMENTED messages MUST appear in the same order as the
7496 * messages they respond to. Hence, never queue them.
7498 ssh2_pkt_send_noqueue(ssh, pktout);
7502 * Handle the top-level SSH2 protocol.
7504 static void ssh2_protocol_setup(Ssh ssh)
7509 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
7511 for (i = 0; i < 256; i++)
7512 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
7515 * Any message we actually understand, we set to NULL so that
7516 * the coroutines will get it.
7518 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
7519 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
7520 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
7521 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
7522 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
7523 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
7524 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
7525 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
7526 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
7527 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
7528 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
7529 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
7530 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
7531 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
7532 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7533 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
7534 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
7535 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
7536 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
7537 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
7538 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
7539 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
7540 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
7541 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
7542 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
7543 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
7544 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
7545 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
7546 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
7547 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
7548 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
7549 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
7550 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
7553 * These special message types we install handlers for.
7555 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
7556 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with ssh1 */
7557 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
7560 static void ssh2_timer(void *ctx, long now)
7564 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
7565 now - ssh->next_rekey >= 0) {
7566 do_ssh2_transport(ssh, "timeout", -1, NULL);
7570 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
7571 struct Packet *pktin)
7573 unsigned char *in = (unsigned char *)vin;
7574 if (ssh->state == SSH_STATE_CLOSED)
7578 ssh->incoming_data_size += pktin->encrypted_len;
7579 if (!ssh->kex_in_progress &&
7580 ssh->max_data_size != 0 &&
7581 ssh->incoming_data_size > ssh->max_data_size)
7582 do_ssh2_transport(ssh, "too much data received", -1, NULL);
7585 if (pktin && ssh->packet_dispatch[pktin->type]) {
7586 ssh->packet_dispatch[pktin->type](ssh, pktin);
7590 if (!ssh->protocol_initial_phase_done ||
7591 (pktin && pktin->type >= 20 && pktin->type < 50)) {
7592 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
7593 !ssh->protocol_initial_phase_done) {
7594 ssh->protocol_initial_phase_done = TRUE;
7596 * Allow authconn to initialise itself.
7598 do_ssh2_authconn(ssh, NULL, 0, NULL);
7601 do_ssh2_authconn(ssh, in, inlen, pktin);
7606 * Called to set up the connection.
7608 * Returns an error message, or NULL on success.
7610 static const char *ssh_init(void *frontend_handle, void **backend_handle,
7612 char *host, int port, char **realhost, int nodelay,
7618 ssh = snew(struct ssh_tag);
7619 ssh->cfg = *cfg; /* STRUCTURE COPY */
7620 ssh->version = 0; /* when not ready yet */
7623 ssh->v1_cipher_ctx = NULL;
7624 ssh->crcda_ctx = NULL;
7625 ssh->cscipher = NULL;
7626 ssh->cs_cipher_ctx = NULL;
7627 ssh->sccipher = NULL;
7628 ssh->sc_cipher_ctx = NULL;
7630 ssh->cs_mac_ctx = NULL;
7632 ssh->sc_mac_ctx = NULL;
7634 ssh->cs_comp_ctx = NULL;
7636 ssh->sc_comp_ctx = NULL;
7638 ssh->kex_ctx = NULL;
7639 ssh->hostkey = NULL;
7641 ssh->close_expected = FALSE;
7642 ssh->state = SSH_STATE_PREPACKET;
7643 ssh->size_needed = FALSE;
7644 ssh->eof_needed = FALSE;
7647 ssh->deferred_send_data = NULL;
7648 ssh->deferred_len = 0;
7649 ssh->deferred_size = 0;
7650 ssh->fallback_cmd = 0;
7652 ssh->x11auth = NULL;
7653 ssh->v1_compressing = FALSE;
7654 ssh->v2_outgoing_sequence = 0;
7655 ssh->ssh1_rdpkt_crstate = 0;
7656 ssh->ssh2_rdpkt_crstate = 0;
7657 ssh->do_ssh_init_crstate = 0;
7658 ssh->ssh_gotdata_crstate = 0;
7659 ssh->do_ssh1_connection_crstate = 0;
7660 ssh->do_ssh1_login_crstate = 0;
7661 ssh->do_ssh2_transport_crstate = 0;
7662 ssh->do_ssh2_authconn_crstate = 0;
7663 ssh->do_ssh_init_state = NULL;
7664 ssh->do_ssh1_login_state = NULL;
7665 ssh->do_ssh2_transport_state = NULL;
7666 ssh->do_ssh2_authconn_state = NULL;
7667 ssh->mainchan = NULL;
7668 ssh->throttled_all = 0;
7669 ssh->v1_stdout_throttling = 0;
7671 ssh->queuelen = ssh->queuesize = 0;
7672 ssh->queueing = FALSE;
7673 ssh->qhead = ssh->qtail = NULL;
7674 ssh->deferred_rekey_reason = NULL;
7675 bufchain_init(&ssh->queued_incoming_data);
7676 ssh->frozen = FALSE;
7678 *backend_handle = ssh;
7681 if (crypto_startup() == 0)
7682 return "Microsoft high encryption pack not installed!";
7685 ssh->frontend = frontend_handle;
7686 ssh->term_width = ssh->cfg.width;
7687 ssh->term_height = ssh->cfg.height;
7689 ssh->channels = NULL;
7690 ssh->rportfwds = NULL;
7691 ssh->portfwds = NULL;
7696 ssh->v1_throttle_count = 0;
7697 ssh->overall_bufsize = 0;
7698 ssh->fallback_cmd = 0;
7700 ssh->protocol = NULL;
7702 ssh->protocol_initial_phase_done = FALSE;
7706 ssh->incoming_data_size = ssh->outgoing_data_size =
7707 ssh->deferred_data_size = 0L;
7708 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
7709 ssh->kex_in_progress = FALSE;
7711 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
7720 static void ssh_free(void *handle)
7722 Ssh ssh = (Ssh) handle;
7723 struct ssh_channel *c;
7724 struct ssh_rportfwd *pf;
7726 if (ssh->v1_cipher_ctx)
7727 ssh->cipher->free_context(ssh->v1_cipher_ctx);
7728 if (ssh->cs_cipher_ctx)
7729 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7730 if (ssh->sc_cipher_ctx)
7731 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7732 if (ssh->cs_mac_ctx)
7733 ssh->csmac->free_context(ssh->cs_mac_ctx);
7734 if (ssh->sc_mac_ctx)
7735 ssh->scmac->free_context(ssh->sc_mac_ctx);
7736 if (ssh->cs_comp_ctx) {
7738 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7740 zlib_compress_cleanup(ssh->cs_comp_ctx);
7742 if (ssh->sc_comp_ctx) {
7744 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7746 zlib_decompress_cleanup(ssh->sc_comp_ctx);
7749 dh_cleanup(ssh->kex_ctx);
7750 sfree(ssh->savedhost);
7752 while (ssh->queuelen-- > 0)
7753 ssh_free_packet(ssh->queue[ssh->queuelen]);
7756 while (ssh->qhead) {
7757 struct queued_handler *qh = ssh->qhead;
7758 ssh->qhead = qh->next;
7761 ssh->qhead = ssh->qtail = NULL;
7763 if (ssh->channels) {
7764 while ((c = delpos234(ssh->channels, 0)) != NULL) {
7767 if (c->u.x11.s != NULL)
7768 x11_close(c->u.x11.s);
7771 if (c->u.pfd.s != NULL)
7772 pfd_close(c->u.pfd.s);
7777 freetree234(ssh->channels);
7778 ssh->channels = NULL;
7781 if (ssh->rportfwds) {
7782 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
7784 freetree234(ssh->rportfwds);
7785 ssh->rportfwds = NULL;
7787 sfree(ssh->deferred_send_data);
7789 x11_free_auth(ssh->x11auth);
7790 sfree(ssh->do_ssh_init_state);
7791 sfree(ssh->do_ssh1_login_state);
7792 sfree(ssh->do_ssh2_transport_state);
7793 sfree(ssh->do_ssh2_authconn_state);
7794 if (ssh->crcda_ctx) {
7795 crcda_free_context(ssh->crcda_ctx);
7796 ssh->crcda_ctx = NULL;
7799 ssh_do_close(ssh, TRUE);
7800 expire_timer_context(ssh);
7802 pinger_free(ssh->pinger);
7803 bufchain_clear(&ssh->queued_incoming_data);
7810 * Reconfigure the SSH backend.
7812 static void ssh_reconfig(void *handle, Config *cfg)
7814 Ssh ssh = (Ssh) handle;
7815 char *rekeying = NULL, rekey_mandatory = FALSE;
7816 unsigned long old_max_data_size;
7818 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
7819 ssh_setup_portfwd(ssh, cfg);
7821 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
7822 cfg->ssh_rekey_time != 0) {
7823 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
7824 long now = GETTICKCOUNT();
7826 if (new_next - now < 0) {
7827 rekeying = "timeout shortened";
7829 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
7833 old_max_data_size = ssh->max_data_size;
7834 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
7835 if (old_max_data_size != ssh->max_data_size &&
7836 ssh->max_data_size != 0) {
7837 if (ssh->outgoing_data_size > ssh->max_data_size ||
7838 ssh->incoming_data_size > ssh->max_data_size)
7839 rekeying = "data limit lowered";
7842 if (ssh->cfg.compression != cfg->compression) {
7843 rekeying = "compression setting changed";
7844 rekey_mandatory = TRUE;
7847 if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
7848 memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
7849 sizeof(ssh->cfg.ssh_cipherlist))) {
7850 rekeying = "cipher settings changed";
7851 rekey_mandatory = TRUE;
7854 ssh->cfg = *cfg; /* STRUCTURE COPY */
7857 if (!ssh->kex_in_progress) {
7858 do_ssh2_transport(ssh, rekeying, -1, NULL);
7859 } else if (rekey_mandatory) {
7860 ssh->deferred_rekey_reason = rekeying;
7866 * Called to send data down the Telnet connection.
7868 static int ssh_send(void *handle, char *buf, int len)
7870 Ssh ssh = (Ssh) handle;
7872 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
7875 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
7877 return ssh_sendbuffer(ssh);
7881 * Called to query the current amount of buffered stdin data.
7883 static int ssh_sendbuffer(void *handle)
7885 Ssh ssh = (Ssh) handle;
7888 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
7892 * If the SSH socket itself has backed up, add the total backup
7893 * size on that to any individual buffer on the stdin channel.
7896 if (ssh->throttled_all)
7897 override_value = ssh->overall_bufsize;
7899 if (ssh->version == 1) {
7900 return override_value;
7901 } else if (ssh->version == 2) {
7902 if (!ssh->mainchan || ssh->mainchan->closes > 0)
7903 return override_value;
7905 return (override_value +
7906 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
7913 * Called to set the size of the window from SSH's POV.
7915 static void ssh_size(void *handle, int width, int height)
7917 Ssh ssh = (Ssh) handle;
7918 struct Packet *pktout;
7920 ssh->term_width = width;
7921 ssh->term_height = height;
7923 switch (ssh->state) {
7924 case SSH_STATE_BEFORE_SIZE:
7925 case SSH_STATE_PREPACKET:
7926 case SSH_STATE_CLOSED:
7927 break; /* do nothing */
7928 case SSH_STATE_INTERMED:
7929 ssh->size_needed = TRUE; /* buffer for later */
7931 case SSH_STATE_SESSION:
7932 if (!ssh->cfg.nopty) {
7933 if (ssh->version == 1) {
7934 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
7935 PKT_INT, ssh->term_height,
7936 PKT_INT, ssh->term_width,
7937 PKT_INT, 0, PKT_INT, 0, PKT_END);
7938 } else if (ssh->mainchan) {
7939 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7940 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7941 ssh2_pkt_addstring(pktout, "window-change");
7942 ssh2_pkt_addbool(pktout, 0);
7943 ssh2_pkt_adduint32(pktout, ssh->term_width);
7944 ssh2_pkt_adduint32(pktout, ssh->term_height);
7945 ssh2_pkt_adduint32(pktout, 0);
7946 ssh2_pkt_adduint32(pktout, 0);
7947 ssh2_pkt_send(ssh, pktout);
7955 * Return a list of the special codes that make sense in this
7958 static const struct telnet_special *ssh_get_specials(void *handle)
7960 static const struct telnet_special ssh1_ignore_special[] = {
7961 {"IGNORE message", TS_NOP}
7963 static const struct telnet_special ssh2_transport_specials[] = {
7964 {"IGNORE message", TS_NOP},
7965 {"Repeat key exchange", TS_REKEY},
7967 static const struct telnet_special ssh2_session_specials[] = {
7970 /* These are the signal names defined by draft-ietf-secsh-connect-23.
7971 * They include all the ISO C signals, but are a subset of the POSIX
7972 * required signals. */
7973 {"SIGINT (Interrupt)", TS_SIGINT},
7974 {"SIGTERM (Terminate)", TS_SIGTERM},
7975 {"SIGKILL (Kill)", TS_SIGKILL},
7976 {"SIGQUIT (Quit)", TS_SIGQUIT},
7977 {"SIGHUP (Hangup)", TS_SIGHUP},
7978 {"More signals", TS_SUBMENU},
7979 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
7980 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
7981 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
7982 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
7985 static const struct telnet_special specials_end[] = {
7988 /* XXX review this length for any changes: */
7989 static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
7990 lenof(ssh2_session_specials) +
7991 lenof(specials_end)];
7992 Ssh ssh = (Ssh) handle;
7994 #define ADD_SPECIALS(name) \
7996 assert((i + lenof(name)) <= lenof(ssh_specials)); \
7997 memcpy(&ssh_specials[i], name, sizeof name); \
8001 if (ssh->version == 1) {
8002 /* Don't bother offering IGNORE if we've decided the remote
8003 * won't cope with it, since we wouldn't bother sending it if
8005 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
8006 ADD_SPECIALS(ssh1_ignore_special);
8007 } else if (ssh->version == 2) {
8008 ADD_SPECIALS(ssh2_transport_specials);
8010 ADD_SPECIALS(ssh2_session_specials);
8011 } /* else we're not ready yet */
8014 ADD_SPECIALS(specials_end);
8015 return ssh_specials;
8023 * Send Telnet special codes. TS_EOF is useful for `plink', so you
8024 * can send an EOF and collect resulting output (e.g. `plink
8027 static void ssh_special(void *handle, Telnet_Special code)
8029 Ssh ssh = (Ssh) handle;
8030 struct Packet *pktout;
8032 if (code == TS_EOF) {
8033 if (ssh->state != SSH_STATE_SESSION) {
8035 * Buffer the EOF in case we are pre-SESSION, so we can
8036 * send it as soon as we reach SESSION.
8039 ssh->eof_needed = TRUE;
8042 if (ssh->version == 1) {
8043 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
8044 } else if (ssh->mainchan) {
8045 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
8046 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8047 ssh2_pkt_send(ssh, pktout);
8049 logevent("Sent EOF message");
8050 } else if (code == TS_PING || code == TS_NOP) {
8051 if (ssh->state == SSH_STATE_CLOSED
8052 || ssh->state == SSH_STATE_PREPACKET) return;
8053 if (ssh->version == 1) {
8054 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
8055 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
8057 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
8058 ssh2_pkt_addstring_start(pktout);
8059 ssh2_pkt_send_noqueue(ssh, pktout);
8061 } else if (code == TS_REKEY) {
8062 if (!ssh->kex_in_progress && ssh->version == 2) {
8063 do_ssh2_transport(ssh, "at user request", -1, NULL);
8065 } else if (code == TS_BRK) {
8066 if (ssh->state == SSH_STATE_CLOSED
8067 || ssh->state == SSH_STATE_PREPACKET) return;
8068 if (ssh->version == 1) {
8069 logevent("Unable to send BREAK signal in SSH1");
8070 } else if (ssh->mainchan) {
8071 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8072 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8073 ssh2_pkt_addstring(pktout, "break");
8074 ssh2_pkt_addbool(pktout, 0);
8075 ssh2_pkt_adduint32(pktout, 0); /* default break length */
8076 ssh2_pkt_send(ssh, pktout);
8079 /* Is is a POSIX signal? */
8080 char *signame = NULL;
8081 if (code == TS_SIGABRT) signame = "ABRT";
8082 if (code == TS_SIGALRM) signame = "ALRM";
8083 if (code == TS_SIGFPE) signame = "FPE";
8084 if (code == TS_SIGHUP) signame = "HUP";
8085 if (code == TS_SIGILL) signame = "ILL";
8086 if (code == TS_SIGINT) signame = "INT";
8087 if (code == TS_SIGKILL) signame = "KILL";
8088 if (code == TS_SIGPIPE) signame = "PIPE";
8089 if (code == TS_SIGQUIT) signame = "QUIT";
8090 if (code == TS_SIGSEGV) signame = "SEGV";
8091 if (code == TS_SIGTERM) signame = "TERM";
8092 if (code == TS_SIGUSR1) signame = "USR1";
8093 if (code == TS_SIGUSR2) signame = "USR2";
8094 /* The SSH-2 protocol does in principle support arbitrary named
8095 * signals, including signame@domain, but we don't support those. */
8097 /* It's a signal. */
8098 if (ssh->version == 2 && ssh->mainchan) {
8099 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8100 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8101 ssh2_pkt_addstring(pktout, "signal");
8102 ssh2_pkt_addbool(pktout, 0);
8103 ssh2_pkt_addstring(pktout, signame);
8104 ssh2_pkt_send(ssh, pktout);
8105 logeventf(ssh, "Sent signal SIG%s", signame);
8108 /* Never heard of it. Do nothing */
8113 void *new_sock_channel(void *handle, Socket s)
8115 Ssh ssh = (Ssh) handle;
8116 struct ssh_channel *c;
8117 c = snew(struct ssh_channel);
8122 c->localid = alloc_channel_id(ssh);
8124 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
8126 bufchain_init(&c->v.v2.outbuffer);
8127 add234(ssh->channels, c);
8133 * This is called when stdout/stderr (the entity to which
8134 * from_backend sends data) manages to clear some backlog.
8136 static void ssh_unthrottle(void *handle, int bufsize)
8138 Ssh ssh = (Ssh) handle;
8139 if (ssh->version == 1) {
8140 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
8141 ssh->v1_stdout_throttling = 0;
8142 ssh1_throttle(ssh, -1);
8145 if (ssh->mainchan && ssh->mainchan->closes == 0)
8146 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
8150 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
8152 struct ssh_channel *c = (struct ssh_channel *)channel;
8154 struct Packet *pktout;
8156 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
8158 if (ssh->version == 1) {
8159 send_packet(ssh, SSH1_MSG_PORT_OPEN,
8160 PKT_INT, c->localid,
8163 /* PKT_STR, <org:orgport>, */
8166 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
8167 ssh2_pkt_addstring(pktout, "direct-tcpip");
8168 ssh2_pkt_adduint32(pktout, c->localid);
8169 c->v.v2.locwindow = OUR_V2_WINSIZE;
8170 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
8171 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8172 ssh2_pkt_addstring(pktout, hostname);
8173 ssh2_pkt_adduint32(pktout, port);
8175 * We make up values for the originator data; partly it's
8176 * too much hassle to keep track, and partly I'm not
8177 * convinced the server should be told details like that
8178 * about my local network configuration.
8180 ssh2_pkt_addstring(pktout, "client-side-connection");
8181 ssh2_pkt_adduint32(pktout, 0);
8182 ssh2_pkt_send(ssh, pktout);
8186 static Socket ssh_socket(void *handle)
8188 Ssh ssh = (Ssh) handle;
8192 static int ssh_sendok(void *handle)
8194 Ssh ssh = (Ssh) handle;
8195 return ssh->send_ok;
8198 static int ssh_ldisc(void *handle, int option)
8200 Ssh ssh = (Ssh) handle;
8201 if (option == LD_ECHO)
8202 return ssh->echoing;
8203 if (option == LD_EDIT)
8204 return ssh->editing;
8208 static void ssh_provide_ldisc(void *handle, void *ldisc)
8210 Ssh ssh = (Ssh) handle;
8214 static void ssh_provide_logctx(void *handle, void *logctx)
8216 Ssh ssh = (Ssh) handle;
8217 ssh->logctx = logctx;
8220 static int ssh_return_exitcode(void *handle)
8222 Ssh ssh = (Ssh) handle;
8226 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
8230 * cfg_info for SSH is the currently running version of the
8231 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
8233 static int ssh_cfg_info(void *handle)
8235 Ssh ssh = (Ssh) handle;
8236 return ssh->version;
8240 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
8241 * that fails. This variable is the means by which scp.c can reach
8242 * into the SSH code and find out which one it got.
8244 extern int ssh_fallback_cmd(void *handle)
8246 Ssh ssh = (Ssh) handle;
8247 return ssh->fallback_cmd;
8250 Backend ssh_backend = {
8260 ssh_return_exitcode,