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_DHGROUP1 0x0001
108 #define SSH2_PKTCTX_DHGEX 0x0002
109 #define SSH2_PKTCTX_PUBLICKEY 0x0010
110 #define SSH2_PKTCTX_PASSWORD 0x0020
111 #define SSH2_PKTCTX_KBDINTER 0x0040
112 #define SSH2_PKTCTX_AUTH_MASK 0x00F0
114 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
115 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
116 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
117 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
118 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
119 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
120 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
121 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
122 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
123 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
124 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
125 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
126 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
127 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
128 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
130 static const char *const ssh2_disconnect_reasons[] = {
132 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
133 "SSH_DISCONNECT_PROTOCOL_ERROR",
134 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
135 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
136 "SSH_DISCONNECT_MAC_ERROR",
137 "SSH_DISCONNECT_COMPRESSION_ERROR",
138 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
139 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
140 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
141 "SSH_DISCONNECT_CONNECTION_LOST",
142 "SSH_DISCONNECT_BY_APPLICATION",
143 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
144 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
145 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
146 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
149 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
150 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
151 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
152 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
154 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
157 * Various remote-bug flags.
159 #define BUG_CHOKES_ON_SSH1_IGNORE 1
160 #define BUG_SSH2_HMAC 2
161 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
162 #define BUG_CHOKES_ON_RSA 8
163 #define BUG_SSH2_RSA_PADDING 16
164 #define BUG_SSH2_DERIVEKEY 32
165 #define BUG_SSH2_DH_GEX 64
166 #define BUG_SSH2_PK_SESSIONID 128
168 #define translate(x) if (type == x) return #x
169 #define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
170 static char *ssh1_pkt_type(int type)
172 translate(SSH1_MSG_DISCONNECT);
173 translate(SSH1_SMSG_PUBLIC_KEY);
174 translate(SSH1_CMSG_SESSION_KEY);
175 translate(SSH1_CMSG_USER);
176 translate(SSH1_CMSG_AUTH_RSA);
177 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
178 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
179 translate(SSH1_CMSG_AUTH_PASSWORD);
180 translate(SSH1_CMSG_REQUEST_PTY);
181 translate(SSH1_CMSG_WINDOW_SIZE);
182 translate(SSH1_CMSG_EXEC_SHELL);
183 translate(SSH1_CMSG_EXEC_CMD);
184 translate(SSH1_SMSG_SUCCESS);
185 translate(SSH1_SMSG_FAILURE);
186 translate(SSH1_CMSG_STDIN_DATA);
187 translate(SSH1_SMSG_STDOUT_DATA);
188 translate(SSH1_SMSG_STDERR_DATA);
189 translate(SSH1_CMSG_EOF);
190 translate(SSH1_SMSG_EXIT_STATUS);
191 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
192 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
193 translate(SSH1_MSG_CHANNEL_DATA);
194 translate(SSH1_MSG_CHANNEL_CLOSE);
195 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
196 translate(SSH1_SMSG_X11_OPEN);
197 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
198 translate(SSH1_MSG_PORT_OPEN);
199 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
200 translate(SSH1_SMSG_AGENT_OPEN);
201 translate(SSH1_MSG_IGNORE);
202 translate(SSH1_CMSG_EXIT_CONFIRMATION);
203 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
204 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
205 translate(SSH1_MSG_DEBUG);
206 translate(SSH1_CMSG_REQUEST_COMPRESSION);
207 translate(SSH1_CMSG_AUTH_TIS);
208 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
209 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
210 translate(SSH1_CMSG_AUTH_CCARD);
211 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
212 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
215 static char *ssh2_pkt_type(int pkt_ctx, int type)
217 translate(SSH2_MSG_DISCONNECT);
218 translate(SSH2_MSG_IGNORE);
219 translate(SSH2_MSG_UNIMPLEMENTED);
220 translate(SSH2_MSG_DEBUG);
221 translate(SSH2_MSG_SERVICE_REQUEST);
222 translate(SSH2_MSG_SERVICE_ACCEPT);
223 translate(SSH2_MSG_KEXINIT);
224 translate(SSH2_MSG_NEWKEYS);
225 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP1);
226 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP1);
227 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
228 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
229 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
230 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
231 translate(SSH2_MSG_USERAUTH_REQUEST);
232 translate(SSH2_MSG_USERAUTH_FAILURE);
233 translate(SSH2_MSG_USERAUTH_SUCCESS);
234 translate(SSH2_MSG_USERAUTH_BANNER);
235 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
236 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
237 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
238 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
239 translate(SSH2_MSG_GLOBAL_REQUEST);
240 translate(SSH2_MSG_REQUEST_SUCCESS);
241 translate(SSH2_MSG_REQUEST_FAILURE);
242 translate(SSH2_MSG_CHANNEL_OPEN);
243 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
244 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
245 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
246 translate(SSH2_MSG_CHANNEL_DATA);
247 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
248 translate(SSH2_MSG_CHANNEL_EOF);
249 translate(SSH2_MSG_CHANNEL_CLOSE);
250 translate(SSH2_MSG_CHANNEL_REQUEST);
251 translate(SSH2_MSG_CHANNEL_SUCCESS);
252 translate(SSH2_MSG_CHANNEL_FAILURE);
258 #define GET_32BIT(cp) \
259 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
260 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
261 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
262 ((unsigned long)(unsigned char)(cp)[3]))
264 #define PUT_32BIT(cp, value) { \
265 (cp)[0] = (unsigned char)((value) >> 24); \
266 (cp)[1] = (unsigned char)((value) >> 16); \
267 (cp)[2] = (unsigned char)((value) >> 8); \
268 (cp)[3] = (unsigned char)(value); }
270 /* Enumeration values for fields in SSH-1 packets */
272 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
273 /* These values are for communicating relevant semantics of
274 * fields to the packet logging code. */
275 PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA
279 * Coroutine mechanics for the sillier bits of the code. If these
280 * macros look impenetrable to you, you might find it helpful to
283 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
285 * which explains the theory behind these macros.
287 * In particular, if you are getting `case expression not constant'
288 * errors when building with MS Visual Studio, this is because MS's
289 * Edit and Continue debugging feature causes their compiler to
290 * violate ANSI C. To disable Edit and Continue debugging:
292 * - right-click ssh.c in the FileView
294 * - select the C/C++ tab and the General category
295 * - under `Debug info:', select anything _other_ than `Program
296 * Database for Edit and Continue'.
298 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
301 if (!ssh->t) ssh->t = snew(struct t); \
303 #define crFinish(z) } *crLine = 0; return (z); }
304 #define crFinishV } *crLine = 0; return; }
305 #define crReturn(z) \
307 *crLine =__LINE__; return (z); case __LINE__:;\
311 *crLine=__LINE__; return; case __LINE__:;\
313 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
314 #define crStopV do{ *crLine = 0; return; }while(0)
315 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
316 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
318 typedef struct ssh_tag *Ssh;
320 static void ssh2_pkt_init(Ssh, int pkt_type);
321 static void ssh2_pkt_addbool(Ssh, unsigned char value);
322 static void ssh2_pkt_adduint32(Ssh, unsigned long value);
323 static void ssh2_pkt_addstring_start(Ssh);
324 static void ssh2_pkt_addstring_str(Ssh, char *data);
325 static void ssh2_pkt_addstring_data(Ssh, char *data, int len);
326 static void ssh2_pkt_addstring(Ssh, char *data);
327 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
328 static void ssh2_pkt_addmp(Ssh, Bignum b);
329 static int ssh2_pkt_construct(Ssh);
330 static void ssh2_pkt_send(Ssh);
331 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt);
332 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt);
335 * Buffer management constants. There are several of these for
336 * various different purposes:
338 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
339 * on a local data stream before we throttle the whole SSH
340 * connection (in SSH1 only). Throttling the whole connection is
341 * pretty drastic so we set this high in the hope it won't
344 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
345 * on the SSH connection itself before we defensively throttle
346 * _all_ local data streams. This is pretty drastic too (though
347 * thankfully unlikely in SSH2 since the window mechanism should
348 * ensure that the server never has any need to throttle its end
349 * of the connection), so we set this high as well.
351 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
355 #define SSH1_BUFFER_LIMIT 32768
356 #define SSH_MAX_BACKLOG 32768
357 #define OUR_V2_WINSIZE 16384
359 const static struct ssh_kex *kex_algs[] = {
360 &ssh_diffiehellman_gex,
364 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
366 static void *nullmac_make_context(void)
370 static void nullmac_free_context(void *handle)
373 static void nullmac_key(void *handle, unsigned char *key)
376 static void nullmac_generate(void *handle, unsigned char *blk, int len,
380 static int nullmac_verify(void *handle, unsigned char *blk, int len,
385 const static struct ssh_mac ssh_mac_none = {
386 nullmac_make_context, nullmac_free_context, nullmac_key,
387 nullmac_generate, nullmac_verify, "none", 0
389 const static struct ssh_mac *macs[] = {
390 &ssh_sha1, &ssh_md5, &ssh_mac_none
392 const static struct ssh_mac *buggymacs[] = {
393 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
396 static void *ssh_comp_none_init(void)
400 static void ssh_comp_none_cleanup(void *handle)
403 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
404 unsigned char **outblock, int *outlen)
408 static int ssh_comp_none_disable(void *handle)
412 const static struct ssh_compress ssh_comp_none = {
414 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
415 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
416 ssh_comp_none_disable, NULL
418 extern const struct ssh_compress ssh_zlib;
419 const static struct ssh_compress *compressions[] = {
420 &ssh_zlib, &ssh_comp_none
423 enum { /* channel types */
428 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
432 * 2-3-4 tree storing channels.
435 Ssh ssh; /* pointer back to main context */
436 unsigned remoteid, localid;
439 * In SSH1, this value contains four bits:
441 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
442 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
443 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
444 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
446 * A channel is completely finished with when all four bits are set.
450 struct ssh1_data_channel {
453 struct ssh2_data_channel {
455 unsigned remwindow, remmaxpkt;
460 struct ssh_agent_channel {
461 unsigned char *message;
462 unsigned char msglen[4];
463 int lensofar, totallen;
465 struct ssh_x11_channel {
468 struct ssh_pfd_channel {
475 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
476 * 2 use this structure in different ways, reflecting SSH 2's
477 * altogether saner approach to port forwarding.
479 * In SSH 1, you arrange a remote forwarding by sending the server
480 * the remote port number, and the local destination host:port.
481 * When a connection comes in, the server sends you back that
482 * host:port pair, and you connect to it. This is a ready-made
483 * security hole if you're not on the ball: a malicious server
484 * could send you back _any_ host:port pair, so if you trustingly
485 * connect to the address it gives you then you've just opened the
486 * entire inside of your corporate network just by connecting
487 * through it to a dodgy SSH server. Hence, we must store a list of
488 * host:port pairs we _are_ trying to forward to, and reject a
489 * connection request from the server if it's not in the list.
491 * In SSH 2, each side of the connection minds its own business and
492 * doesn't send unnecessary information to the other. You arrange a
493 * remote forwarding by sending the server just the remote port
494 * number. When a connection comes in, the server tells you which
495 * of its ports was connected to; and _you_ have to remember what
496 * local host:port pair went with that port number.
498 * Hence: in SSH 1 this structure stores host:port pairs we intend
499 * to allow connections to, and is indexed by those host:port
500 * pairs. In SSH 2 it stores a mapping from source port to
501 * destination host:port pair, and is indexed by source port.
503 struct ssh_rportfwd {
504 unsigned sport, dport;
517 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
518 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
519 static void ssh_size(void *handle, int width, int height);
520 static void ssh_special(void *handle, Telnet_Special);
521 static int ssh2_try_send(struct ssh_channel *c);
522 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
523 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
524 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
525 static int ssh_sendbuffer(void *handle);
526 static void ssh_do_close(Ssh ssh);
528 struct rdpkt1_state_tag {
529 long len, pad, biglen, to_read;
530 unsigned long realcrc, gotcrc;
536 struct rdpkt2_state_tag {
537 long len, pad, payload, packetlen, maclen;
540 unsigned long incoming_sequence;
544 const struct plug_function_table *fn;
545 /* the above field _must_ be first in the structure */
547 SHA_State exhash, exhashbase;
554 unsigned char session_key[32];
556 int v1_remote_protoflags;
557 int v1_local_protoflags;
558 int agentfwd_enabled;
561 const struct ssh_cipher *cipher;
564 const struct ssh2_cipher *cscipher, *sccipher;
565 void *cs_cipher_ctx, *sc_cipher_ctx;
566 const struct ssh_mac *csmac, *scmac;
567 void *cs_mac_ctx, *sc_mac_ctx;
568 const struct ssh_compress *cscomp, *sccomp;
569 void *cs_comp_ctx, *sc_comp_ctx;
570 const struct ssh_kex *kex;
571 const struct ssh_signkey *hostkey;
572 unsigned char v2_session_id[20];
578 int echoing, editing;
582 int ospeed, ispeed; /* temporaries */
583 int term_width, term_height;
585 tree234 *channels; /* indexed by local id */
586 struct ssh_channel *mainchan; /* primary session channel */
593 SSH_STATE_BEFORE_SIZE,
599 int size_needed, eof_needed;
602 struct Packet pktout;
603 unsigned char *deferred_send_data;
604 int deferred_len, deferred_size;
607 * State associated with packet logging
611 struct logblank_t *pktout_blanks;
614 * Gross hack: pscp will try to start SFTP but fall back to
615 * scp1 if that fails. This variable is the means by which
616 * scp.c can reach into the SSH code and find out which one it
622 * Used for username and password input.
624 char *userpass_input_buffer;
625 int userpass_input_buflen;
626 int userpass_input_bufpos;
627 int userpass_input_echo;
629 char *portfwd_strptr;
635 int v1_throttle_count;
638 int v1_stdout_throttling;
639 int v2_outgoing_sequence;
641 int ssh1_rdpkt_crstate;
642 int ssh2_rdpkt_crstate;
643 int do_ssh_init_crstate;
644 int ssh_gotdata_crstate;
645 int ssh1_protocol_crstate;
646 int do_ssh1_login_crstate;
647 int do_ssh2_transport_crstate;
648 int do_ssh2_authconn_crstate;
650 void *do_ssh_init_state;
651 void *do_ssh1_login_state;
652 void *do_ssh2_transport_state;
653 void *do_ssh2_authconn_state;
655 struct rdpkt1_state_tag rdpkt1_state;
656 struct rdpkt2_state_tag rdpkt2_state;
658 void (*protocol) (Ssh ssh, unsigned char *in, int inlen, int ispkt);
659 int (*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
662 * We maintain a full _copy_ of a Config structure here, not
663 * merely a pointer to it. That way, when we're passed a new
664 * one for reconfiguration, we can check the differences and
665 * potentially reconfigure port forwardings etc in mid-session.
670 * Used to transfer data back from async agent callbacks.
672 void *agent_response;
673 int agent_response_len;
676 #define logevent(s) logevent(ssh->frontend, s)
678 /* logevent, only printf-formatted. */
679 static void logeventf(Ssh ssh, const char *fmt, ...)
685 buf = dupvprintf(fmt, ap);
691 #define bombout(msg) \
693 char *text = dupprintf msg; \
696 connection_fatal(ssh->frontend, "%s", text); \
700 /* Functions to leave bits out of the SSH packet log file. */
702 static void dont_log_password(Ssh ssh, int blanktype)
704 if (ssh->cfg.logomitpass)
705 ssh->pktout_logmode = blanktype;
708 static void dont_log_data(Ssh ssh, int blanktype)
710 if (ssh->cfg.logomitdata)
711 ssh->pktout_logmode = blanktype;
714 static void end_log_omission(Ssh ssh)
716 ssh->pktout_logmode = PKTLOG_EMIT;
719 static int ssh_channelcmp(void *av, void *bv)
721 struct ssh_channel *a = (struct ssh_channel *) av;
722 struct ssh_channel *b = (struct ssh_channel *) bv;
723 if (a->localid < b->localid)
725 if (a->localid > b->localid)
729 static int ssh_channelfind(void *av, void *bv)
731 unsigned *a = (unsigned *) av;
732 struct ssh_channel *b = (struct ssh_channel *) bv;
740 static int ssh_rportcmp_ssh1(void *av, void *bv)
742 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
743 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
745 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
746 return i < 0 ? -1 : +1;
747 if (a->dport > b->dport)
749 if (a->dport < b->dport)
754 static int ssh_rportcmp_ssh2(void *av, void *bv)
756 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
757 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
759 if (a->sport > b->sport)
761 if (a->sport < b->sport)
766 static int alloc_channel_id(Ssh ssh)
768 const unsigned CHANNEL_NUMBER_OFFSET = 256;
769 unsigned low, high, mid;
771 struct ssh_channel *c;
774 * First-fit allocation of channel numbers: always pick the
775 * lowest unused one. To do this, binary-search using the
776 * counted B-tree to find the largest channel ID which is in a
777 * contiguous sequence from the beginning. (Precisely
778 * everything in that sequence must have ID equal to its tree
779 * index plus CHANNEL_NUMBER_OFFSET.)
781 tsize = count234(ssh->channels);
785 while (high - low > 1) {
786 mid = (high + low) / 2;
787 c = index234(ssh->channels, mid);
788 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
789 low = mid; /* this one is fine */
791 high = mid; /* this one is past it */
794 * Now low points to either -1, or the tree index of the
795 * largest ID in the initial sequence.
798 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
799 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
801 return low + 1 + CHANNEL_NUMBER_OFFSET;
804 static void c_write(Ssh ssh, const char *buf, int len)
806 if ((flags & FLAG_STDERR)) {
808 for (i = 0; i < len; i++)
810 fputc(buf[i], stderr);
813 from_backend(ssh->frontend, 1, buf, len);
816 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
819 for (i = 0; i < len; i++) {
821 c_write(ssh, "\r\n", 2);
822 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
823 c_write(ssh, buf + i, 1);
827 static void c_write_str(Ssh ssh, const char *buf)
829 c_write(ssh, buf, strlen(buf));
833 * Collect incoming data in the incoming packet buffer.
834 * Decipher and verify the packet when it is completely read.
835 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
836 * Update the *data and *datalen variables.
837 * Return the additional nr of bytes needed, or 0 when
838 * a complete packet is available.
840 static int ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
842 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
844 crBegin(ssh->ssh1_rdpkt_crstate);
849 ssh->pktin.length = 0;
851 for (st->i = st->len = 0; st->i < 4; st->i++) {
852 while ((*datalen) == 0)
854 st->len = (st->len << 8) + **data;
855 (*data)++, (*datalen)--;
858 st->pad = 8 - (st->len % 8);
859 st->biglen = st->len + st->pad;
860 ssh->pktin.length = st->len - 5;
862 if (st->biglen < 0) {
863 bombout(("Extremely large packet length from server suggests"
864 " data stream corruption"));
868 if (ssh->pktin.maxlen < st->biglen) {
869 ssh->pktin.maxlen = st->biglen;
870 ssh->pktin.data = sresize(ssh->pktin.data, st->biglen + APIEXTRA,
874 st->to_read = st->biglen;
875 st->p = ssh->pktin.data;
876 while (st->to_read > 0) {
877 st->chunk = st->to_read;
878 while ((*datalen) == 0)
879 crReturn(st->to_read);
880 if (st->chunk > (*datalen))
881 st->chunk = (*datalen);
882 memcpy(st->p, *data, st->chunk);
884 *datalen -= st->chunk;
886 st->to_read -= st->chunk;
889 if (ssh->cipher && detect_attack(ssh->crcda_ctx, ssh->pktin.data,
891 bombout(("Network attack (CRC compensation) detected!"));
896 ssh->cipher->decrypt(ssh->v1_cipher_ctx, ssh->pktin.data, st->biglen);
898 st->realcrc = crc32_compute(ssh->pktin.data, st->biglen - 4);
899 st->gotcrc = GET_32BIT(ssh->pktin.data + st->biglen - 4);
900 if (st->gotcrc != st->realcrc) {
901 bombout(("Incorrect CRC received on packet"));
905 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
906 ssh->pktin.savedpos = 0;
908 if (ssh->v1_compressing) {
909 unsigned char *decompblk;
911 if (!zlib_decompress_block(ssh->sc_comp_ctx,
912 ssh->pktin.body - 1, ssh->pktin.length + 1,
913 &decompblk, &decomplen)) {
914 bombout(("Zlib decompression encountered invalid data"));
918 if (ssh->pktin.maxlen < st->pad + decomplen) {
919 ssh->pktin.maxlen = st->pad + decomplen;
920 ssh->pktin.data = sresize(ssh->pktin.data,
921 ssh->pktin.maxlen + APIEXTRA,
923 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
926 memcpy(ssh->pktin.body - 1, decompblk, decomplen);
928 ssh->pktin.length = decomplen - 1;
931 ssh->pktin.type = ssh->pktin.body[-1];
934 * Log incoming packet, possibly omitting sensitive fields.
938 struct logblank_t blank;
939 if (ssh->cfg.logomitdata) {
940 int do_blank = FALSE, blank_prefix = 0;
941 /* "Session data" packets - omit the data field */
942 if ((ssh->pktin.type == SSH1_SMSG_STDOUT_DATA) ||
943 (ssh->pktin.type == SSH1_SMSG_STDERR_DATA)) {
944 do_blank = TRUE; blank_prefix = 0;
945 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) {
946 do_blank = TRUE; blank_prefix = 4;
949 blank.offset = blank_prefix;
950 blank.len = ssh->pktin.length;
951 blank.type = PKTLOG_OMIT;
955 log_packet(ssh->logctx,
956 PKT_INCOMING, ssh->pktin.type,
957 ssh1_pkt_type(ssh->pktin.type),
958 ssh->pktin.body, ssh->pktin.length,
962 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
963 ssh->pktin.type == SSH1_SMSG_STDERR_DATA ||
964 ssh->pktin.type == SSH1_MSG_DEBUG ||
965 ssh->pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
966 ssh->pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
967 long stringlen = GET_32BIT(ssh->pktin.body);
968 if (stringlen + 4 != ssh->pktin.length) {
969 bombout(("Received data packet with bogus string length"));
974 if (ssh->pktin.type == SSH1_MSG_DEBUG) {
975 /* log debug message */
977 int stringlen = GET_32BIT(ssh->pktin.body);
978 strcpy(buf, "Remote debug message: ");
981 memcpy(buf + 8, ssh->pktin.body + 4, stringlen);
982 buf[8 + stringlen] = '\0';
985 } else if (ssh->pktin.type == SSH1_MSG_IGNORE) {
990 if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
991 /* log reason code in disconnect message */
993 unsigned msglen = GET_32BIT(ssh->pktin.body);
995 strcpy(buf, "Remote sent disconnect: ");
996 nowlen = strlen(buf);
997 if (msglen > sizeof(buf) - nowlen - 1)
998 msglen = sizeof(buf) - nowlen - 1;
999 memcpy(buf + nowlen, ssh->pktin.body + 4, msglen);
1000 buf[nowlen + msglen] = '\0';
1001 /* logevent(buf); (this is now done within the bombout macro) */
1002 bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
1009 static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1011 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1013 crBegin(ssh->ssh2_rdpkt_crstate);
1016 ssh->pktin.type = 0;
1017 ssh->pktin.length = 0;
1019 st->cipherblk = ssh->sccipher->blksize;
1022 if (st->cipherblk < 8)
1025 if (ssh->pktin.maxlen < st->cipherblk) {
1026 ssh->pktin.maxlen = st->cipherblk;
1027 ssh->pktin.data = sresize(ssh->pktin.data, st->cipherblk + APIEXTRA,
1032 * Acquire and decrypt the first block of the packet. This will
1033 * contain the length and padding details.
1035 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1036 while ((*datalen) == 0)
1037 crReturn(st->cipherblk - st->i);
1038 ssh->pktin.data[st->i] = *(*data)++;
1043 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1044 ssh->pktin.data, st->cipherblk);
1047 * Now get the length and padding figures.
1049 st->len = GET_32BIT(ssh->pktin.data);
1050 st->pad = ssh->pktin.data[4];
1053 * _Completely_ silly lengths should be stomped on before they
1054 * do us any more damage.
1056 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
1057 bombout(("Incoming packet was garbled on decryption"));
1062 * This enables us to deduce the payload length.
1064 st->payload = st->len - st->pad - 1;
1066 ssh->pktin.length = st->payload + 5;
1069 * So now we can work out the total packet length.
1071 st->packetlen = st->len + 4;
1072 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1075 * Adjust memory allocation if packet is too big.
1077 if (ssh->pktin.maxlen < st->packetlen + st->maclen) {
1078 ssh->pktin.maxlen = st->packetlen + st->maclen;
1079 ssh->pktin.data = sresize(ssh->pktin.data,
1080 ssh->pktin.maxlen + APIEXTRA,
1085 * Read and decrypt the remainder of the packet.
1087 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1089 while ((*datalen) == 0)
1090 crReturn(st->packetlen + st->maclen - st->i);
1091 ssh->pktin.data[st->i] = *(*data)++;
1094 /* Decrypt everything _except_ the MAC. */
1096 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1097 ssh->pktin.data + st->cipherblk,
1098 st->packetlen - st->cipherblk);
1104 && !ssh->scmac->verify(ssh->sc_mac_ctx, ssh->pktin.data, st->len + 4,
1105 st->incoming_sequence)) {
1106 bombout(("Incorrect MAC received on packet"));
1109 st->incoming_sequence++; /* whether or not we MACed */
1112 * Decompress packet payload.
1115 unsigned char *newpayload;
1118 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1119 ssh->pktin.data + 5, ssh->pktin.length - 5,
1120 &newpayload, &newlen)) {
1121 if (ssh->pktin.maxlen < newlen + 5) {
1122 ssh->pktin.maxlen = newlen + 5;
1123 ssh->pktin.data = sresize(ssh->pktin.data,
1124 ssh->pktin.maxlen + APIEXTRA,
1127 ssh->pktin.length = 5 + newlen;
1128 memcpy(ssh->pktin.data + 5, newpayload, newlen);
1133 ssh->pktin.savedpos = 6;
1134 ssh->pktin.body = ssh->pktin.data;
1135 ssh->pktin.type = ssh->pktin.data[5];
1138 * Log incoming packet, possibly omitting sensitive fields.
1142 struct logblank_t blank;
1143 if (ssh->cfg.logomitdata) {
1144 int do_blank = FALSE, blank_prefix = 0;
1145 /* "Session data" packets - omit the data field */
1146 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA) {
1147 do_blank = TRUE; blank_prefix = 4;
1148 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1149 do_blank = TRUE; blank_prefix = 8;
1152 blank.offset = blank_prefix;
1153 blank.len = (ssh->pktin.length-6) - blank_prefix;
1154 blank.type = PKTLOG_OMIT;
1158 log_packet(ssh->logctx, PKT_INCOMING, ssh->pktin.type,
1159 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktin.type),
1160 ssh->pktin.data+6, ssh->pktin.length-6,
1164 switch (ssh->pktin.type) {
1166 * These packets we must handle instantly.
1168 case SSH2_MSG_DISCONNECT:
1170 /* log reason code in disconnect message */
1173 int reason = GET_32BIT(ssh->pktin.data + 6);
1174 unsigned msglen = GET_32BIT(ssh->pktin.data + 10);
1176 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
1177 buf = dupprintf("Received disconnect message (%s)",
1178 ssh2_disconnect_reasons[reason]);
1180 buf = dupprintf("Received disconnect message (unknown"
1181 " type %d)", reason);
1185 buf = dupprintf("Disconnection message text: %n%.*s",
1186 &nowlen, msglen, ssh->pktin.data + 14);
1188 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1190 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1191 ssh2_disconnect_reasons[reason] : "unknown",
1197 case SSH2_MSG_IGNORE:
1199 case SSH2_MSG_DEBUG:
1201 /* log the debug message */
1203 /* int display = ssh->pktin.body[6]; */
1204 int stringlen = GET_32BIT(ssh->pktin.data+7);
1206 strcpy(buf, "Remote debug message: ");
1207 prefix = strlen(buf);
1208 if (stringlen > (int)(sizeof(buf)-prefix-1))
1209 stringlen = sizeof(buf)-prefix-1;
1210 memcpy(buf + prefix, ssh->pktin.data + 11, stringlen);
1211 buf[prefix + stringlen] = '\0';
1214 goto next_packet; /* FIXME: print the debug message */
1217 * These packets we need do nothing about here.
1219 case SSH2_MSG_UNIMPLEMENTED:
1220 case SSH2_MSG_SERVICE_REQUEST:
1221 case SSH2_MSG_SERVICE_ACCEPT:
1222 case SSH2_MSG_KEXINIT:
1223 case SSH2_MSG_NEWKEYS:
1224 case SSH2_MSG_KEXDH_INIT:
1225 case SSH2_MSG_KEXDH_REPLY:
1226 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1227 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1228 case SSH2_MSG_KEX_DH_GEX_INIT:
1229 case SSH2_MSG_KEX_DH_GEX_REPLY:
1230 case SSH2_MSG_USERAUTH_REQUEST:
1231 case SSH2_MSG_USERAUTH_FAILURE:
1232 case SSH2_MSG_USERAUTH_SUCCESS:
1233 case SSH2_MSG_USERAUTH_BANNER:
1234 case SSH2_MSG_USERAUTH_PK_OK:
1235 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1236 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1237 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1238 case SSH2_MSG_GLOBAL_REQUEST:
1239 case SSH2_MSG_REQUEST_SUCCESS:
1240 case SSH2_MSG_REQUEST_FAILURE:
1241 case SSH2_MSG_CHANNEL_OPEN:
1242 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1243 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1244 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1245 case SSH2_MSG_CHANNEL_DATA:
1246 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1247 case SSH2_MSG_CHANNEL_EOF:
1248 case SSH2_MSG_CHANNEL_CLOSE:
1249 case SSH2_MSG_CHANNEL_REQUEST:
1250 case SSH2_MSG_CHANNEL_SUCCESS:
1251 case SSH2_MSG_CHANNEL_FAILURE:
1255 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1258 ssh2_pkt_init(ssh, SSH2_MSG_UNIMPLEMENTED);
1259 ssh2_pkt_adduint32(ssh, st->incoming_sequence - 1);
1267 static void ssh1_pktout_size(Ssh ssh, int len)
1271 len += 5; /* type and CRC */
1272 pad = 8 - (len % 8);
1275 ssh->pktout.length = len - 5;
1276 if (ssh->pktout.maxlen < biglen) {
1277 ssh->pktout.maxlen = biglen;
1279 /* Allocate enough buffer space for extra block
1280 * for MS CryptEncrypt() */
1281 ssh->pktout.data = sresize(ssh->pktout.data, biglen + 12,
1284 ssh->pktout.data = sresize(ssh->pktout.data, biglen + 4,
1288 ssh->pktout.body = ssh->pktout.data + 4 + pad + 1;
1291 static void s_wrpkt_start(Ssh ssh, int type, int len)
1293 ssh1_pktout_size(ssh, len);
1294 ssh->pktout.type = type;
1295 /* Initialise log omission state */
1296 ssh->pktout_nblanks = 0;
1297 ssh->pktout_blanks = NULL;
1300 static int s_wrpkt_prepare(Ssh ssh)
1306 * XXX various versions of SC (including 8.8.4) screw up the
1307 * register allocation in this function and use the same register
1308 * (D6) for len and as a temporary, with predictable results. The
1309 * following sledgehammer prevents this.
1315 ssh->pktout.body[-1] = ssh->pktout.type;
1318 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.type,
1319 ssh1_pkt_type(ssh->pktout.type),
1320 ssh->pktout.body, ssh->pktout.length,
1321 ssh->pktout_nblanks, ssh->pktout_blanks);
1322 sfree(ssh->pktout_blanks); ssh->pktout_blanks = NULL;
1323 ssh->pktout_nblanks = 0;
1325 if (ssh->v1_compressing) {
1326 unsigned char *compblk;
1328 zlib_compress_block(ssh->cs_comp_ctx,
1329 ssh->pktout.body - 1, ssh->pktout.length + 1,
1330 &compblk, &complen);
1331 ssh1_pktout_size(ssh, complen - 1);
1332 memcpy(ssh->pktout.body - 1, compblk, complen);
1336 len = ssh->pktout.length + 5; /* type and CRC */
1337 pad = 8 - (len % 8);
1340 for (i = 0; i < pad; i++)
1341 ssh->pktout.data[i + 4] = random_byte();
1342 crc = crc32_compute(ssh->pktout.data + 4, biglen - 4);
1343 PUT_32BIT(ssh->pktout.data + biglen, crc);
1344 PUT_32BIT(ssh->pktout.data, len);
1347 ssh->cipher->encrypt(ssh->v1_cipher_ctx, ssh->pktout.data + 4, biglen);
1352 static void s_wrpkt(Ssh ssh)
1355 len = s_wrpkt_prepare(ssh);
1356 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
1357 if (backlog > SSH_MAX_BACKLOG)
1358 ssh_throttle_all(ssh, 1, backlog);
1361 static void s_wrpkt_defer(Ssh ssh)
1364 len = s_wrpkt_prepare(ssh);
1365 if (ssh->deferred_len + len > ssh->deferred_size) {
1366 ssh->deferred_size = ssh->deferred_len + len + 128;
1367 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1371 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1372 ssh->deferred_len += len;
1376 * Construct a packet with the specified contents.
1378 static void construct_packet(Ssh ssh, int pkttype, va_list ap1, va_list ap2)
1380 unsigned char *p, *argp, argchar;
1381 unsigned long argint;
1382 int pktlen, argtype, arglen;
1386 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1389 (void) va_arg(ap1, int);
1393 (void) va_arg(ap1, int);
1397 (void) va_arg(ap1, unsigned char *);
1398 arglen = va_arg(ap1, int);
1402 argp = va_arg(ap1, unsigned char *);
1403 arglen = strlen((char *)argp);
1404 pktlen += 4 + arglen;
1407 bn = va_arg(ap1, Bignum);
1408 pktlen += ssh1_bignum_length(bn);
1413 /* ignore this pass */
1420 s_wrpkt_start(ssh, pkttype, pktlen);
1421 p = ssh->pktout.body;
1423 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1424 int offset = p - ssh->pktout.body, len = 0;
1426 /* Actual fields in the packet */
1428 argint = va_arg(ap2, int);
1429 PUT_32BIT(p, argint);
1433 argchar = (unsigned char) va_arg(ap2, int);
1438 argp = va_arg(ap2, unsigned char *);
1439 arglen = va_arg(ap2, int);
1440 memcpy(p, argp, arglen);
1444 argp = va_arg(ap2, unsigned char *);
1445 arglen = strlen((char *)argp);
1446 PUT_32BIT(p, arglen);
1447 memcpy(p + 4, argp, arglen);
1451 bn = va_arg(ap2, Bignum);
1452 len = ssh1_write_bignum(p, bn);
1454 /* Tokens for modifications to packet logging */
1456 dont_log_password(ssh, PKTLOG_BLANK);
1459 dont_log_data(ssh, PKTLOG_OMIT);
1462 end_log_omission(ssh);
1466 /* Deal with logfile omission, if required. */
1467 if (len && (ssh->pktout_logmode != PKTLOG_EMIT)) {
1468 ssh->pktout_nblanks++;
1469 ssh->pktout_blanks = sresize(ssh->pktout_blanks,
1470 ssh->pktout_nblanks,
1472 ssh->pktout_blanks[ssh->pktout_nblanks-1].offset = offset;
1473 ssh->pktout_blanks[ssh->pktout_nblanks-1].len = len;
1474 ssh->pktout_blanks[ssh->pktout_nblanks-1].type =
1475 ssh->pktout_logmode;
1480 static void send_packet(Ssh ssh, int pkttype, ...)
1483 va_start(ap1, pkttype);
1484 va_start(ap2, pkttype);
1485 construct_packet(ssh, pkttype, ap1, ap2);
1489 static void defer_packet(Ssh ssh, int pkttype, ...)
1492 va_start(ap1, pkttype);
1493 va_start(ap2, pkttype);
1494 construct_packet(ssh, pkttype, ap1, ap2);
1498 static int ssh_versioncmp(char *a, char *b)
1501 unsigned long av, bv;
1503 av = strtoul(a, &ae, 10);
1504 bv = strtoul(b, &be, 10);
1506 return (av < bv ? -1 : +1);
1511 av = strtoul(ae, &ae, 10);
1512 bv = strtoul(be, &be, 10);
1514 return (av < bv ? -1 : +1);
1519 * Utility routines for putting an SSH-protocol `string' and
1520 * `uint32' into a SHA state.
1523 static void sha_string(SHA_State * s, void *str, int len)
1525 unsigned char lenblk[4];
1526 PUT_32BIT(lenblk, len);
1527 SHA_Bytes(s, lenblk, 4);
1528 SHA_Bytes(s, str, len);
1531 static void sha_uint32(SHA_State * s, unsigned i)
1533 unsigned char intblk[4];
1534 PUT_32BIT(intblk, i);
1535 SHA_Bytes(s, intblk, 4);
1539 * SSH2 packet construction functions.
1541 static void ssh2_pkt_ensure(Ssh ssh, int length)
1543 if (ssh->pktout.maxlen < length) {
1544 ssh->pktout.maxlen = length + 256;
1545 ssh->pktout.data = sresize(ssh->pktout.data,
1546 ssh->pktout.maxlen + APIEXTRA,
1548 if (!ssh->pktout.data)
1549 fatalbox("Out of memory");
1552 static void ssh2_pkt_adddata(Ssh ssh, void *data, int len)
1554 if (ssh->pktout_logmode != PKTLOG_EMIT) {
1555 ssh->pktout_nblanks++;
1556 ssh->pktout_blanks = sresize(ssh->pktout_blanks, ssh->pktout_nblanks,
1558 ssh->pktout_blanks[ssh->pktout_nblanks-1].offset =
1559 ssh->pktout.length - 6;
1560 ssh->pktout_blanks[ssh->pktout_nblanks-1].len = len;
1561 ssh->pktout_blanks[ssh->pktout_nblanks-1].type = ssh->pktout_logmode;
1563 ssh->pktout.length += len;
1564 ssh2_pkt_ensure(ssh, ssh->pktout.length);
1565 memcpy(ssh->pktout.data + ssh->pktout.length - len, data, len);
1567 static void ssh2_pkt_addbyte(Ssh ssh, unsigned char byte)
1569 ssh2_pkt_adddata(ssh, &byte, 1);
1571 static void ssh2_pkt_init(Ssh ssh, int pkt_type)
1573 ssh->pktout.length = 5;
1574 ssh->pktout_nblanks = 0; ssh->pktout_blanks = NULL;
1575 ssh2_pkt_addbyte(ssh, (unsigned char) pkt_type);
1577 static void ssh2_pkt_addbool(Ssh ssh, unsigned char value)
1579 ssh2_pkt_adddata(ssh, &value, 1);
1581 static void ssh2_pkt_adduint32(Ssh ssh, unsigned long value)
1584 PUT_32BIT(x, value);
1585 ssh2_pkt_adddata(ssh, x, 4);
1587 static void ssh2_pkt_addstring_start(Ssh ssh)
1589 ssh2_pkt_adduint32(ssh, 0);
1590 ssh->pktout.savedpos = ssh->pktout.length;
1592 static void ssh2_pkt_addstring_str(Ssh ssh, char *data)
1594 ssh2_pkt_adddata(ssh, data, strlen(data));
1595 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1596 ssh->pktout.length - ssh->pktout.savedpos);
1598 static void ssh2_pkt_addstring_data(Ssh ssh, char *data, int len)
1600 ssh2_pkt_adddata(ssh, data, len);
1601 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1602 ssh->pktout.length - ssh->pktout.savedpos);
1604 static void ssh2_pkt_addstring(Ssh ssh, char *data)
1606 ssh2_pkt_addstring_start(ssh);
1607 ssh2_pkt_addstring_str(ssh, data);
1609 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1612 int i, n = (bignum_bitcount(b) + 7) / 8;
1613 p = snewn(n + 1, unsigned char);
1615 fatalbox("out of memory");
1617 for (i = 1; i <= n; i++)
1618 p[i] = bignum_byte(b, n - i);
1620 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1622 memmove(p, p + i, n + 1 - i);
1626 static void ssh2_pkt_addmp(Ssh ssh, Bignum b)
1630 p = ssh2_mpint_fmt(b, &len);
1631 ssh2_pkt_addstring_start(ssh);
1632 ssh2_pkt_addstring_data(ssh, (char *)p, len);
1637 * Construct an SSH2 final-form packet: compress it, encrypt it,
1638 * put the MAC on it. Final packet, ready to be sent, is stored in
1639 * ssh->pktout.data. Total length is returned.
1641 static int ssh2_pkt_construct(Ssh ssh)
1643 int cipherblk, maclen, padding, i;
1646 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.data[5],
1647 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktout.data[5]),
1648 ssh->pktout.data + 6, ssh->pktout.length - 6,
1649 ssh->pktout_nblanks, ssh->pktout_blanks);
1650 sfree(ssh->pktout_blanks); ssh->pktout_blanks = NULL;
1651 ssh->pktout_nblanks = 0;
1654 * Compress packet payload.
1657 unsigned char *newpayload;
1660 ssh->cscomp->compress(ssh->cs_comp_ctx, ssh->pktout.data + 5,
1661 ssh->pktout.length - 5,
1662 &newpayload, &newlen)) {
1663 ssh->pktout.length = 5;
1664 ssh2_pkt_adddata(ssh, newpayload, newlen);
1670 * Add padding. At least four bytes, and must also bring total
1671 * length (minus MAC) up to a multiple of the block size.
1673 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1674 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1677 (cipherblk - (ssh->pktout.length + padding) % cipherblk) % cipherblk;
1678 maclen = ssh->csmac ? ssh->csmac->len : 0;
1679 ssh2_pkt_ensure(ssh, ssh->pktout.length + padding + maclen);
1680 ssh->pktout.data[4] = padding;
1681 for (i = 0; i < padding; i++)
1682 ssh->pktout.data[ssh->pktout.length + i] = random_byte();
1683 PUT_32BIT(ssh->pktout.data, ssh->pktout.length + padding - 4);
1685 ssh->csmac->generate(ssh->cs_mac_ctx, ssh->pktout.data,
1686 ssh->pktout.length + padding,
1687 ssh->v2_outgoing_sequence);
1688 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1691 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1692 ssh->pktout.data, ssh->pktout.length + padding);
1694 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1695 return ssh->pktout.length + padding + maclen;
1699 * Construct and send an SSH2 packet immediately.
1701 static void ssh2_pkt_send(Ssh ssh)
1705 len = ssh2_pkt_construct(ssh);
1706 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
1707 if (backlog > SSH_MAX_BACKLOG)
1708 ssh_throttle_all(ssh, 1, backlog);
1712 * Construct an SSH2 packet and add it to a deferred data block.
1713 * Useful for sending multiple packets in a single sk_write() call,
1714 * to prevent a traffic-analysing listener from being able to work
1715 * out the length of any particular packet (such as the password
1718 * Note that because SSH2 sequence-numbers its packets, this can
1719 * NOT be used as an m4-style `defer' allowing packets to be
1720 * constructed in one order and sent in another.
1722 static void ssh2_pkt_defer(Ssh ssh)
1724 int len = ssh2_pkt_construct(ssh);
1725 if (ssh->deferred_len + len > ssh->deferred_size) {
1726 ssh->deferred_size = ssh->deferred_len + len + 128;
1727 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1731 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1732 ssh->deferred_len += len;
1736 * Send the whole deferred data block constructed by
1737 * ssh2_pkt_defer() or SSH1's defer_packet().
1739 static void ssh_pkt_defersend(Ssh ssh)
1742 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1744 ssh->deferred_len = ssh->deferred_size = 0;
1745 sfree(ssh->deferred_send_data);
1746 ssh->deferred_send_data = NULL;
1747 if (backlog > SSH_MAX_BACKLOG)
1748 ssh_throttle_all(ssh, 1, backlog);
1752 void bndebug(char *string, Bignum b)
1756 p = ssh2_mpint_fmt(b, &len);
1757 debug(("%s", string));
1758 for (i = 0; i < len; i++)
1759 debug((" %02x", p[i]));
1765 static void sha_mpint(SHA_State * s, Bignum b)
1769 p = ssh2_mpint_fmt(b, &len);
1770 sha_string(s, p, len);
1775 * Packet decode functions for both SSH1 and SSH2.
1777 static unsigned long ssh_pkt_getuint32(Ssh ssh)
1779 unsigned long value;
1780 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1781 return 0; /* arrgh, no way to decline (FIXME?) */
1782 value = GET_32BIT(ssh->pktin.body + ssh->pktin.savedpos);
1783 ssh->pktin.savedpos += 4;
1786 static int ssh2_pkt_getbool(Ssh ssh)
1788 unsigned long value;
1789 if (ssh->pktin.length - ssh->pktin.savedpos < 1)
1790 return 0; /* arrgh, no way to decline (FIXME?) */
1791 value = ssh->pktin.body[ssh->pktin.savedpos] != 0;
1792 ssh->pktin.savedpos++;
1795 static void ssh_pkt_getstring(Ssh ssh, char **p, int *length)
1800 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1802 len = GET_32BIT(ssh->pktin.body + ssh->pktin.savedpos);
1806 ssh->pktin.savedpos += 4;
1807 if (ssh->pktin.length - ssh->pktin.savedpos < *length)
1809 *p = (char *)(ssh->pktin.body + ssh->pktin.savedpos);
1810 ssh->pktin.savedpos += *length;
1812 static void *ssh_pkt_getdata(Ssh ssh, int length)
1814 if (ssh->pktin.length - ssh->pktin.savedpos < length)
1816 ssh->pktin.savedpos += length;
1817 return ssh->pktin.body + (ssh->pktin.savedpos - length);
1819 static int ssh1_pkt_getrsakey(Ssh ssh, struct RSAKey *key,
1820 unsigned char **keystr)
1824 j = makekey(ssh->pktin.body + ssh->pktin.savedpos,
1825 ssh->pktin.length - ssh->pktin.savedpos,
1831 ssh->pktin.savedpos += j;
1832 assert(ssh->pktin.savedpos < ssh->pktin.length);
1836 static Bignum ssh1_pkt_getmp(Ssh ssh)
1841 j = ssh1_read_bignum(ssh->pktin.body + ssh->pktin.savedpos,
1842 ssh->pktin.length - ssh->pktin.savedpos, &b);
1847 ssh->pktin.savedpos += j;
1850 static Bignum ssh2_pkt_getmp(Ssh ssh)
1856 ssh_pkt_getstring(ssh, &p, &length);
1860 bombout(("internal error: Can't handle negative mpints"));
1863 b = bignum_from_bytes((unsigned char *)p, length);
1868 * Helper function to add an SSH2 signature blob to a packet.
1869 * Expects to be shown the public key blob as well as the signature
1870 * blob. Normally works just like ssh2_pkt_addstring, but will
1871 * fiddle with the signature packet if necessary for
1872 * BUG_SSH2_RSA_PADDING.
1874 static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len,
1875 void *sigblob_v, int sigblob_len)
1877 unsigned char *pkblob = (unsigned char *)pkblob_v;
1878 unsigned char *sigblob = (unsigned char *)sigblob_v;
1880 /* dmemdump(pkblob, pkblob_len); */
1881 /* dmemdump(sigblob, sigblob_len); */
1884 * See if this is in fact an ssh-rsa signature and a buggy
1885 * server; otherwise we can just do this the easy way.
1887 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1888 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1889 int pos, len, siglen;
1892 * Find the byte length of the modulus.
1895 pos = 4+7; /* skip over "ssh-rsa" */
1896 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1897 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1898 pos += 4; /* find modulus itself */
1899 while (len > 0 && pkblob[pos] == 0)
1901 /* debug(("modulus length is %d\n", len)); */
1904 * Now find the signature integer.
1906 pos = 4+7; /* skip over "ssh-rsa" */
1907 siglen = GET_32BIT(sigblob+pos);
1908 /* debug(("signature length is %d\n", siglen)); */
1910 if (len != siglen) {
1911 unsigned char newlen[4];
1912 ssh2_pkt_addstring_start(ssh);
1913 ssh2_pkt_addstring_data(ssh, (char *)sigblob, pos);
1914 /* dmemdump(sigblob, pos); */
1915 pos += 4; /* point to start of actual sig */
1916 PUT_32BIT(newlen, len);
1917 ssh2_pkt_addstring_data(ssh, (char *)newlen, 4);
1918 /* dmemdump(newlen, 4); */
1920 while (len-- > siglen) {
1921 ssh2_pkt_addstring_data(ssh, (char *)newlen, 1);
1922 /* dmemdump(newlen, 1); */
1924 ssh2_pkt_addstring_data(ssh, (char *)(sigblob+pos), siglen);
1925 /* dmemdump(sigblob+pos, siglen); */
1929 /* Otherwise fall through and do it the easy way. */
1932 ssh2_pkt_addstring_start(ssh);
1933 ssh2_pkt_addstring_data(ssh, (char *)sigblob, sigblob_len);
1937 * Examine the remote side's version string and compare it against
1938 * a list of known buggy implementations.
1940 static void ssh_detect_bugs(Ssh ssh, char *vstring)
1942 char *imp; /* pointer to implementation part */
1944 imp += strcspn(imp, "-");
1946 imp += strcspn(imp, "-");
1949 ssh->remote_bugs = 0;
1951 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
1952 (ssh->cfg.sshbug_ignore1 == AUTO &&
1953 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1954 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1955 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
1956 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
1958 * These versions don't support SSH1_MSG_IGNORE, so we have
1959 * to use a different defence against password length
1962 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1963 logevent("We believe remote version has SSH1 ignore bug");
1966 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
1967 (ssh->cfg.sshbug_plainpw1 == AUTO &&
1968 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
1970 * These versions need a plain password sent; they can't
1971 * handle having a null and a random length of data after
1974 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1975 logevent("We believe remote version needs a plain SSH1 password");
1978 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
1979 (ssh->cfg.sshbug_rsa1 == AUTO &&
1980 (!strcmp(imp, "Cisco-1.25")))) {
1982 * These versions apparently have no clue whatever about
1983 * RSA authentication and will panic and die if they see
1984 * an AUTH_RSA message.
1986 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
1987 logevent("We believe remote version can't handle RSA authentication");
1990 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
1991 (ssh->cfg.sshbug_hmac2 == AUTO &&
1992 !wc_match("* VShell", imp) &&
1993 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
1994 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
1995 wc_match("2.1 *", imp)))) {
1997 * These versions have the HMAC bug.
1999 ssh->remote_bugs |= BUG_SSH2_HMAC;
2000 logevent("We believe remote version has SSH2 HMAC bug");
2003 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2004 (ssh->cfg.sshbug_derivekey2 == AUTO &&
2005 !wc_match("* VShell", imp) &&
2006 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2008 * These versions have the key-derivation bug (failing to
2009 * include the literal shared secret in the hashes that
2010 * generate the keys).
2012 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2013 logevent("We believe remote version has SSH2 key-derivation bug");
2016 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2017 (ssh->cfg.sshbug_rsapad2 == AUTO &&
2018 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2019 wc_match("OpenSSH_3.[0-2]*", imp)))) {
2021 * These versions have the SSH2 RSA padding bug.
2023 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2024 logevent("We believe remote version has SSH2 RSA padding bug");
2027 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2028 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2029 wc_match("OpenSSH_2.[0-2]*", imp))) {
2031 * These versions have the SSH2 session-ID bug in
2032 * public-key authentication.
2034 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2035 logevent("We believe remote version has SSH2 public-key-session-ID bug");
2038 if (ssh->cfg.sshbug_dhgex2 == FORCE_ON) {
2040 * User specified the SSH2 DH GEX bug.
2042 ssh->remote_bugs |= BUG_SSH2_DH_GEX;
2043 logevent("We believe remote version has SSH2 DH group exchange bug");
2047 static int do_ssh_init(Ssh ssh, unsigned char c)
2049 struct do_ssh_init_state {
2057 crState(do_ssh_init_state);
2059 crBegin(ssh->do_ssh_init_crstate);
2061 /* Search for the string "SSH-" in the input. */
2064 static const int transS[] = { 1, 2, 2, 1 };
2065 static const int transH[] = { 0, 0, 3, 0 };
2066 static const int transminus[] = { 0, 0, 0, -1 };
2068 s->i = transS[s->i];
2070 s->i = transH[s->i];
2072 s->i = transminus[s->i];
2077 crReturn(1); /* get another character */
2081 s->vstring = snewn(s->vstrsize, char);
2082 strcpy(s->vstring, "SSH-");
2086 crReturn(1); /* get another char */
2087 if (s->vslen >= s->vstrsize - 1) {
2089 s->vstring = sresize(s->vstring, s->vstrsize, char);
2091 s->vstring[s->vslen++] = c;
2094 s->version[s->i] = '\0';
2096 } else if (s->i < sizeof(s->version) - 1)
2097 s->version[s->i++] = c;
2098 } else if (c == '\012')
2102 ssh->agentfwd_enabled = FALSE;
2103 ssh->rdpkt2_state.incoming_sequence = 0;
2105 s->vstring[s->vslen] = 0;
2106 s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */
2109 vlog = snewn(20 + s->vslen, char);
2110 sprintf(vlog, "Server version: %s", s->vstring);
2114 ssh_detect_bugs(ssh, s->vstring);
2117 * Decide which SSH protocol version to support.
2120 /* Anything strictly below "2.0" means protocol 1 is supported. */
2121 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2122 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2123 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2125 if (ssh->cfg.sshprot == 0 && !s->proto1) {
2126 bombout(("SSH protocol version 1 required by user but not provided by server"));
2129 if (ssh->cfg.sshprot == 3 && !s->proto2) {
2130 bombout(("SSH protocol version 2 required by user but not provided by server"));
2134 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2138 char verstring[80], vlog[100];
2139 sprintf(verstring, "SSH-2.0-%s", sshver);
2140 SHA_Init(&ssh->exhashbase);
2142 * Hash our version string and their version string.
2144 sha_string(&ssh->exhashbase, verstring, strlen(verstring));
2145 sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n"));
2146 sprintf(vlog, "We claim version: %s", verstring);
2148 strcat(verstring, "\012");
2149 logevent("Using SSH protocol version 2");
2150 sk_write(ssh->s, verstring, strlen(verstring));
2151 ssh->protocol = ssh2_protocol;
2153 ssh->s_rdpkt = ssh2_rdpkt;
2158 char verstring[80], vlog[100];
2159 sprintf(verstring, "SSH-%s-%s",
2160 (ssh_versioncmp(s->version, "1.5") <= 0 ? s->version : "1.5"),
2162 sprintf(vlog, "We claim version: %s", verstring);
2164 strcat(verstring, "\012");
2166 logevent("Using SSH protocol version 1");
2167 sk_write(ssh->s, verstring, strlen(verstring));
2168 ssh->protocol = ssh1_protocol;
2170 ssh->s_rdpkt = ssh1_rdpkt;
2172 update_specials_menu(ssh->frontend);
2173 ssh->state = SSH_STATE_BEFORE_SIZE;
2180 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2182 crBegin(ssh->ssh_gotdata_crstate);
2185 * To begin with, feed the characters one by one to the
2186 * protocol initialisation / selection function do_ssh_init().
2187 * When that returns 0, we're done with the initial greeting
2188 * exchange and can move on to packet discipline.
2191 int ret; /* need not be kept across crReturn */
2193 crReturnV; /* more data please */
2194 ret = do_ssh_init(ssh, *data);
2202 * We emerge from that loop when the initial negotiation is
2203 * over and we have selected an s_rdpkt function. Now pass
2204 * everything to s_rdpkt, and then pass the resulting packets
2205 * to the proper protocol handler.
2210 while (datalen > 0) {
2211 if (ssh->s_rdpkt(ssh, &data, &datalen) == 0) {
2212 if (ssh->state == SSH_STATE_CLOSED) {
2215 ssh->protocol(ssh, NULL, 0, 1);
2216 if (ssh->state == SSH_STATE_CLOSED) {
2226 static void ssh_do_close(Ssh ssh)
2229 struct ssh_channel *c;
2231 ssh->state = SSH_STATE_CLOSED;
2237 * Now we must shut down any port and X forwardings going
2238 * through this connection.
2240 if (ssh->channels) {
2241 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2244 x11_close(c->u.x11.s);
2247 pfd_close(c->u.pfd.s);
2250 del234(ssh->channels, c);
2251 if (ssh->version == 2)
2252 bufchain_clear(&c->v.v2.outbuffer);
2258 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2261 Ssh ssh = (Ssh) plug;
2264 /* A socket error has occurred. */
2265 logevent(error_msg);
2266 connection_fatal(ssh->frontend, "%s", error_msg);
2268 /* Otherwise, the remote side closed the connection normally. */
2273 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2275 Ssh ssh = (Ssh) plug;
2276 ssh_gotdata(ssh, (unsigned char *)data, len);
2277 if (ssh->state == SSH_STATE_CLOSED) {
2284 static void ssh_sent(Plug plug, int bufsize)
2286 Ssh ssh = (Ssh) plug;
2288 * If the send backlog on the SSH socket itself clears, we
2289 * should unthrottle the whole world if it was throttled.
2291 if (bufsize < SSH_MAX_BACKLOG)
2292 ssh_throttle_all(ssh, 0, bufsize);
2296 * Connect to specified host and port.
2297 * Returns an error message, or NULL on success.
2298 * Also places the canonical host name into `realhost'. It must be
2299 * freed by the caller.
2301 static const char *connect_to_host(Ssh ssh, char *host, int port,
2302 char **realhost, int nodelay, int keepalive)
2304 static const struct plug_function_table fn_table = {
2314 ssh->savedhost = snewn(1 + strlen(host), char);
2315 if (!ssh->savedhost)
2316 fatalbox("Out of memory");
2317 strcpy(ssh->savedhost, host);
2320 port = 22; /* default ssh port */
2321 ssh->savedport = port;
2326 logeventf(ssh, "Looking up host \"%s\"", host);
2327 addr = name_lookup(host, port, realhost, &ssh->cfg);
2328 if ((err = sk_addr_error(addr)) != NULL) {
2338 sk_getaddr(addr, addrbuf, 100);
2339 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
2341 ssh->fn = &fn_table;
2342 ssh->s = new_connection(addr, *realhost, port,
2343 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
2344 if ((err = sk_socket_error(ssh->s)) != NULL) {
2353 * Throttle or unthrottle the SSH connection.
2355 static void ssh1_throttle(Ssh ssh, int adjust)
2357 int old_count = ssh->v1_throttle_count;
2358 ssh->v1_throttle_count += adjust;
2359 assert(ssh->v1_throttle_count >= 0);
2360 if (ssh->v1_throttle_count && !old_count) {
2361 sk_set_frozen(ssh->s, 1);
2362 } else if (!ssh->v1_throttle_count && old_count) {
2363 sk_set_frozen(ssh->s, 0);
2368 * Throttle or unthrottle _all_ local data streams (for when sends
2369 * on the SSH connection itself back up).
2371 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2374 struct ssh_channel *c;
2376 if (enable == ssh->throttled_all)
2378 ssh->throttled_all = enable;
2379 ssh->overall_bufsize = bufsize;
2382 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2384 case CHAN_MAINSESSION:
2386 * This is treated separately, outside the switch.
2390 x11_override_throttle(c->u.x11.s, enable);
2393 /* Agent channels require no buffer management. */
2396 pfd_override_throttle(c->u.pfd.s, enable);
2403 * Username and password input, abstracted off into routines
2404 * reusable in several places - even between SSH1 and SSH2.
2407 /* Set up a username or password input loop on a given buffer. */
2408 static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2410 ssh->userpass_input_buffer = buffer;
2411 ssh->userpass_input_buflen = buflen;
2412 ssh->userpass_input_bufpos = 0;
2413 ssh->userpass_input_echo = echo;
2417 * Process some terminal data in the course of username/password
2418 * input. Returns >0 for success (line of input returned in
2419 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2420 * for inconclusive (keep waiting for more input please).
2422 static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2427 switch (c = *in++) {
2430 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2431 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2436 if (ssh->userpass_input_bufpos > 0) {
2437 if (ssh->userpass_input_echo)
2438 c_write_str(ssh, "\b \b");
2439 ssh->userpass_input_bufpos--;
2444 while (ssh->userpass_input_bufpos > 0) {
2445 if (ssh->userpass_input_echo)
2446 c_write_str(ssh, "\b \b");
2447 ssh->userpass_input_bufpos--;
2456 * This simplistic check for printability is disabled
2457 * when we're doing password input, because some people
2458 * have control characters in their passwords.o
2460 if ((!ssh->userpass_input_echo ||
2461 (c >= ' ' && c <= '~') ||
2462 ((unsigned char) c >= 160))
2463 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2464 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2465 if (ssh->userpass_input_echo)
2466 c_write(ssh, &c, 1);
2474 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
2476 Ssh ssh = (Ssh) sshv;
2478 ssh->agent_response = reply;
2479 ssh->agent_response_len = replylen;
2481 if (ssh->version == 1)
2482 do_ssh1_login(ssh, NULL, -1, 0);
2484 do_ssh2_authconn(ssh, NULL, -1, 0);
2487 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
2489 struct ssh_channel *c = (struct ssh_channel *)cv;
2491 void *sentreply = reply;
2494 /* Fake SSH_AGENT_FAILURE. */
2495 sentreply = "\0\0\0\1\5";
2498 if (ssh->version == 2) {
2499 ssh2_add_channel_data(c, sentreply, replylen);
2502 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2503 PKT_INT, c->remoteid,
2506 PKT_DATA, sentreply, replylen,
2515 * Handle the key exchange and user authentication phases.
2517 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
2520 unsigned char cookie[8], *ptr;
2521 struct RSAKey servkey, hostkey;
2522 struct MD5Context md5c;
2523 struct do_ssh1_login_state {
2525 unsigned char *rsabuf, *keystr1, *keystr2;
2526 unsigned long supported_ciphers_mask, supported_auths_mask;
2527 int tried_publickey, tried_agent;
2528 int tis_auth_refused, ccard_auth_refused;
2529 unsigned char session_id[16];
2532 void *publickey_blob;
2533 int publickey_bloblen;
2539 unsigned char request[5], *response, *p;
2548 crState(do_ssh1_login_state);
2550 crBegin(ssh->do_ssh1_login_crstate);
2555 if (ssh->pktin.type != SSH1_SMSG_PUBLIC_KEY) {
2556 bombout(("Public key packet not received"));
2560 logevent("Received public keys");
2562 ptr = ssh_pkt_getdata(ssh, 8);
2564 bombout(("SSH1 public key packet stopped before random cookie"));
2567 memcpy(cookie, ptr, 8);
2569 if (!ssh1_pkt_getrsakey(ssh, &servkey, &s->keystr1) ||
2570 !ssh1_pkt_getrsakey(ssh, &hostkey, &s->keystr2)) {
2571 bombout(("Failed to read SSH1 public keys from public key packet"));
2576 * Log the host key fingerprint.
2580 logevent("Host key fingerprint is:");
2581 strcpy(logmsg, " ");
2582 hostkey.comment = NULL;
2583 rsa_fingerprint(logmsg + strlen(logmsg),
2584 sizeof(logmsg) - strlen(logmsg), &hostkey);
2588 ssh->v1_remote_protoflags = ssh_pkt_getuint32(ssh);
2589 s->supported_ciphers_mask = ssh_pkt_getuint32(ssh);
2590 s->supported_auths_mask = ssh_pkt_getuint32(ssh);
2592 ssh->v1_local_protoflags =
2593 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2594 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2597 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2598 MD5Update(&md5c, s->keystr1, servkey.bytes);
2599 MD5Update(&md5c, cookie, 8);
2600 MD5Final(s->session_id, &md5c);
2602 for (i = 0; i < 32; i++)
2603 ssh->session_key[i] = random_byte();
2606 * Verify that the `bits' and `bytes' parameters match.
2608 if (hostkey.bits > hostkey.bytes * 8 ||
2609 servkey.bits > servkey.bytes * 8) {
2610 bombout(("SSH1 public keys were badly formatted"));
2614 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2616 s->rsabuf = snewn(s->len, unsigned char);
2618 fatalbox("Out of memory");
2621 * Verify the host key.
2625 * First format the key into a string.
2627 int len = rsastr_len(&hostkey);
2628 char fingerprint[100];
2629 char *keystr = snewn(len, char);
2631 fatalbox("Out of memory");
2632 rsastr_fmt(keystr, &hostkey);
2633 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2634 verify_ssh_host_key(ssh->frontend,
2635 ssh->savedhost, ssh->savedport, "rsa", keystr,
2640 for (i = 0; i < 32; i++) {
2641 s->rsabuf[i] = ssh->session_key[i];
2643 s->rsabuf[i] ^= s->session_id[i];
2646 if (hostkey.bytes > servkey.bytes) {
2647 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2649 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2651 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
2653 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2656 bombout(("SSH1 public key encryptions failed due to bad formatting"));
2660 logevent("Encrypted session key");
2663 int cipher_chosen = 0, warn = 0;
2664 char *cipher_string = NULL;
2666 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2667 int next_cipher = ssh->cfg.ssh_cipherlist[i];
2668 if (next_cipher == CIPHER_WARN) {
2669 /* If/when we choose a cipher, warn about it */
2671 } else if (next_cipher == CIPHER_AES) {
2672 /* XXX Probably don't need to mention this. */
2673 logevent("AES not supported in SSH1, skipping");
2675 switch (next_cipher) {
2676 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
2677 cipher_string = "3DES"; break;
2678 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
2679 cipher_string = "Blowfish"; break;
2680 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
2681 cipher_string = "single-DES"; break;
2683 if (s->supported_ciphers_mask & (1 << s->cipher_type))
2687 if (!cipher_chosen) {
2688 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2689 bombout(("Server violates SSH 1 protocol by not "
2690 "supporting 3DES encryption"));
2692 /* shouldn't happen */
2693 bombout(("No supported ciphers found"));
2697 /* Warn about chosen cipher if necessary. */
2699 askcipher(ssh->frontend, cipher_string, 0);
2702 switch (s->cipher_type) {
2703 case SSH_CIPHER_3DES:
2704 logevent("Using 3DES encryption");
2706 case SSH_CIPHER_DES:
2707 logevent("Using single-DES encryption");
2709 case SSH_CIPHER_BLOWFISH:
2710 logevent("Using Blowfish encryption");
2714 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2715 PKT_CHAR, s->cipher_type,
2716 PKT_DATA, cookie, 8,
2717 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2718 PKT_DATA, s->rsabuf, s->len,
2719 PKT_INT, ssh->v1_local_protoflags, PKT_END);
2721 logevent("Trying to enable encryption...");
2725 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2726 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2728 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2729 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
2730 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
2732 ssh->crcda_ctx = crcda_make_context();
2733 logevent("Installing CRC compensation attack detector");
2735 if (servkey.modulus) {
2736 sfree(servkey.modulus);
2737 servkey.modulus = NULL;
2739 if (servkey.exponent) {
2740 sfree(servkey.exponent);
2741 servkey.exponent = NULL;
2743 if (hostkey.modulus) {
2744 sfree(hostkey.modulus);
2745 hostkey.modulus = NULL;
2747 if (hostkey.exponent) {
2748 sfree(hostkey.exponent);
2749 hostkey.exponent = NULL;
2753 if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2754 bombout(("Encryption not successfully enabled"));
2758 logevent("Successfully started encryption");
2762 if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
2763 if (ssh_get_line && !ssh_getline_pw_only) {
2764 if (!ssh_get_line("login as: ",
2765 s->username, sizeof(s->username), FALSE)) {
2767 * get_line failed to get a username.
2770 logevent("No username provided. Abandoning session.");
2771 ssh_closing((Plug)ssh, NULL, 0, 0);
2775 int ret; /* need not be kept over crReturn */
2776 c_write_str(ssh, "login as: ");
2779 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
2781 crWaitUntil(!ispkt);
2782 ret = process_userpass_input(ssh, in, inlen);
2786 c_write_str(ssh, "\r\n");
2789 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
2790 s->username[sizeof(s->username)-1] = '\0';
2793 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
2795 char userlog[22 + sizeof(s->username)];
2796 sprintf(userlog, "Sent username \"%s\"", s->username);
2798 if (flags & FLAG_INTERACTIVE &&
2799 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2800 strcat(userlog, "\r\n");
2801 c_write_str(ssh, userlog);
2808 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
2809 /* We must not attempt PK auth. Pretend we've already tried it. */
2810 s->tried_publickey = s->tried_agent = 1;
2812 s->tried_publickey = s->tried_agent = 0;
2814 s->tis_auth_refused = s->ccard_auth_refused = 0;
2815 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
2816 if (!filename_is_null(ssh->cfg.keyfile)) {
2817 if (!rsakey_pubblob(&ssh->cfg.keyfile,
2818 &s->publickey_blob, &s->publickey_bloblen, NULL))
2819 s->publickey_blob = NULL;
2821 s->publickey_blob = NULL;
2823 while (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2824 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2826 if (agent_exists() && !s->tried_agent) {
2828 * Attempt RSA authentication using Pageant.
2834 logevent("Pageant is running. Requesting keys.");
2836 /* Request the keys held by the agent. */
2837 PUT_32BIT(s->request, 1);
2838 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2839 if (!agent_query(s->request, 5, &r, &s->responselen,
2840 ssh_agent_callback, ssh)) {
2844 bombout(("Unexpected data from server while waiting"
2845 " for agent response"));
2848 } while (ispkt || inlen > 0);
2849 r = ssh->agent_response;
2850 s->responselen = ssh->agent_response_len;
2852 s->response = (unsigned char *) r;
2853 if (s->response && s->responselen >= 5 &&
2854 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2855 s->p = s->response + 5;
2856 s->nkeys = GET_32BIT(s->p);
2860 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
2863 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2866 sprintf(buf, "Trying Pageant key #%d", s->keyi);
2869 if (s->publickey_blob &&
2870 !memcmp(s->p, s->publickey_blob,
2871 s->publickey_bloblen)) {
2872 logevent("This key matches configured key file");
2873 s->tried_publickey = 1;
2878 do { /* do while (0) to make breaking easy */
2879 n = ssh1_read_bignum
2880 (s->p, s->responselen-(s->p-s->response),
2885 n = ssh1_read_bignum
2886 (s->p, s->responselen-(s->p-s->response),
2891 if (s->responselen - (s->p-s->response) < 4)
2893 s->commentlen = GET_32BIT(s->p);
2895 if (s->responselen - (s->p-s->response) <
2898 s->commentp = (char *)s->p;
2899 s->p += s->commentlen;
2903 logevent("Pageant key list packet was truncated");
2907 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2908 PKT_BIGNUM, s->key.modulus, PKT_END);
2910 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2911 logevent("Key refused");
2914 logevent("Received RSA challenge");
2915 if ((s->challenge = ssh1_pkt_getmp(ssh)) == NULL) {
2916 bombout(("Server's RSA challenge was badly formatted"));
2921 char *agentreq, *q, *ret;
2924 len = 1 + 4; /* message type, bit count */
2925 len += ssh1_bignum_length(s->key.exponent);
2926 len += ssh1_bignum_length(s->key.modulus);
2927 len += ssh1_bignum_length(s->challenge);
2928 len += 16; /* session id */
2929 len += 4; /* response format */
2930 agentreq = snewn(4 + len, char);
2931 PUT_32BIT(agentreq, len);
2933 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2934 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
2936 q += ssh1_write_bignum(q, s->key.exponent);
2937 q += ssh1_write_bignum(q, s->key.modulus);
2938 q += ssh1_write_bignum(q, s->challenge);
2939 memcpy(q, s->session_id, 16);
2941 PUT_32BIT(q, 1); /* response format */
2942 if (!agent_query(agentreq, len + 4, &vret, &retlen,
2943 ssh_agent_callback, ssh)) {
2948 bombout(("Unexpected data from server"
2949 " while waiting for agent"
2953 } while (ispkt || inlen > 0);
2954 vret = ssh->agent_response;
2955 retlen = ssh->agent_response_len;
2960 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2961 logevent("Sending Pageant's response");
2962 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2963 PKT_DATA, ret + 5, 16,
2967 if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
2969 ("Pageant's response accepted");
2970 if (flags & FLAG_VERBOSE) {
2971 c_write_str(ssh, "Authenticated using"
2973 c_write(ssh, s->commentp,
2975 c_write_str(ssh, "\" from agent\r\n");
2980 ("Pageant's response not accepted");
2983 ("Pageant failed to answer challenge");
2987 logevent("No reply received from Pageant");
2990 freebn(s->key.exponent);
2991 freebn(s->key.modulus);
2992 freebn(s->challenge);
3001 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
3002 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
3004 if (ssh->cfg.try_tis_auth &&
3005 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3006 !s->tis_auth_refused) {
3007 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
3008 logevent("Requested TIS authentication");
3009 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
3011 if (ssh->pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
3012 logevent("TIS authentication declined");
3013 if (flags & FLAG_INTERACTIVE)
3014 c_write_str(ssh, "TIS authentication refused.\r\n");
3015 s->tis_auth_refused = 1;
3021 ssh_pkt_getstring(ssh, &challenge, &challengelen);
3023 bombout(("TIS challenge packet was badly formed"));
3026 logevent("Received TIS challenge");
3027 if (challengelen > sizeof(s->prompt) - 1)
3028 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3029 memcpy(s->prompt, challenge, challengelen);
3030 /* Prompt heuristic comes from OpenSSH */
3031 strncpy(s->prompt + challengelen,
3032 memchr(s->prompt, '\n', challengelen) ?
3033 "": "\r\nResponse: ",
3034 (sizeof s->prompt) - challengelen);
3035 s->prompt[(sizeof s->prompt) - 1] = '\0';
3038 if (ssh->cfg.try_tis_auth &&
3039 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3040 !s->ccard_auth_refused) {
3041 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
3042 logevent("Requested CryptoCard authentication");
3043 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
3045 if (ssh->pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
3046 logevent("CryptoCard authentication declined");
3047 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3048 s->ccard_auth_refused = 1;
3054 ssh_pkt_getstring(ssh, &challenge, &challengelen);
3056 bombout(("CryptoCard challenge packet was badly formed"));
3059 logevent("Received CryptoCard challenge");
3060 if (challengelen > sizeof(s->prompt) - 1)
3061 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3062 memcpy(s->prompt, challenge, challengelen);
3063 strncpy(s->prompt + challengelen,
3064 memchr(s->prompt, '\n', challengelen) ?
3065 "" : "\r\nResponse: ",
3066 sizeof(s->prompt) - challengelen);
3067 s->prompt[sizeof(s->prompt) - 1] = '\0';
3070 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3071 sprintf(s->prompt, "%.90s@%.90s's password: ",
3072 s->username, ssh->savedhost);
3074 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3075 char *comment = NULL;
3078 if (flags & FLAG_VERBOSE)
3079 c_write_str(ssh, "Trying public key authentication.\r\n");
3080 logeventf(ssh, "Trying public key \"%s\"",
3081 filename_to_str(&ssh->cfg.keyfile));
3082 type = key_type(&ssh->cfg.keyfile);
3083 if (type != SSH_KEYTYPE_SSH1) {
3084 sprintf(msgbuf, "Key is of wrong type (%s)",
3085 key_type_to_str(type));
3087 c_write_str(ssh, msgbuf);
3088 c_write_str(ssh, "\r\n");
3089 s->tried_publickey = 1;
3092 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
3093 if (flags & FLAG_VERBOSE)
3094 c_write_str(ssh, "No passphrase required.\r\n");
3097 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
3102 * Show password prompt, having first obtained it via a TIS
3103 * or CryptoCard exchange if we're doing TIS or CryptoCard
3107 if (!ssh_get_line(s->prompt, s->password,
3108 sizeof(s->password), TRUE)) {
3110 * get_line failed to get a password (for example
3111 * because one was supplied on the command line
3112 * which has already failed to work). Terminate.
3114 send_packet(ssh, SSH1_MSG_DISCONNECT,
3115 PKT_STR, "No more passwords available to try",
3117 logevent("Unable to authenticate");
3118 connection_fatal(ssh->frontend, "Unable to authenticate");
3119 ssh_closing((Plug)ssh, NULL, 0, 0);
3123 /* Prompt may have come from server. We've munged it a bit, so
3124 * we know it to be zero-terminated at least once. */
3125 int ret; /* need not be saved over crReturn */
3126 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3129 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
3131 crWaitUntil(!ispkt);
3132 ret = process_userpass_input(ssh, in, inlen);
3136 c_write_str(ssh, "\r\n");
3140 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3142 * Try public key authentication with the specified
3145 s->tried_publickey = 1;
3148 const char *error = NULL;
3149 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3152 c_write_str(ssh, "Couldn't load private key from ");
3153 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
3154 c_write_str(ssh, " (");
3155 c_write_str(ssh, error);
3156 c_write_str(ssh, ").\r\n");
3157 continue; /* go and try password */
3160 c_write_str(ssh, "Wrong passphrase.\r\n");
3161 s->tried_publickey = 0;
3162 continue; /* try again */
3167 * Send a public key attempt.
3169 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3170 PKT_BIGNUM, s->key.modulus, PKT_END);
3173 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3174 c_write_str(ssh, "Server refused our public key.\r\n");
3175 continue; /* go and try password */
3177 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3178 bombout(("Bizarre response to offer of public key"));
3184 unsigned char buffer[32];
3185 Bignum challenge, response;
3187 if ((challenge = ssh1_pkt_getmp(ssh)) == NULL) {
3188 bombout(("Server's RSA challenge was badly formatted"));
3191 response = rsadecrypt(challenge, &s->key);
3192 freebn(s->key.private_exponent);/* burn the evidence */
3194 for (i = 0; i < 32; i++) {
3195 buffer[i] = bignum_byte(response, 31 - i);
3199 MD5Update(&md5c, buffer, 32);
3200 MD5Update(&md5c, s->session_id, 16);
3201 MD5Final(buffer, &md5c);
3203 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3204 PKT_DATA, buffer, 16, PKT_END);
3211 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3212 if (flags & FLAG_VERBOSE)
3213 c_write_str(ssh, "Failed to authenticate with"
3214 " our public key.\r\n");
3215 continue; /* go and try password */
3216 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
3217 bombout(("Bizarre response to RSA authentication response"));
3221 break; /* we're through! */
3223 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3225 * Defence against traffic analysis: we send a
3226 * whole bunch of packets containing strings of
3227 * different lengths. One of these strings is the
3228 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3229 * The others are all random data in
3230 * SSH1_MSG_IGNORE packets. This way a passive
3231 * listener can't tell which is the password, and
3232 * hence can't deduce the password length.
3234 * Anybody with a password length greater than 16
3235 * bytes is going to have enough entropy in their
3236 * password that a listener won't find it _that_
3237 * much help to know how long it is. So what we'll
3240 * - if password length < 16, we send 15 packets
3241 * containing string lengths 1 through 15
3243 * - otherwise, we let N be the nearest multiple
3244 * of 8 below the password length, and send 8
3245 * packets containing string lengths N through
3246 * N+7. This won't obscure the order of
3247 * magnitude of the password length, but it will
3248 * introduce a bit of extra uncertainty.
3250 * A few servers (the old 1.2.18 through 1.2.22)
3251 * can't deal with SSH1_MSG_IGNORE. For these
3252 * servers, we need an alternative defence. We make
3253 * use of the fact that the password is interpreted
3254 * as a C string: so we can append a NUL, then some
3257 * One server (a Cisco one) can deal with neither
3258 * SSH1_MSG_IGNORE _nor_ a padded password string.
3259 * For this server we are left with no defences
3260 * against password length sniffing.
3262 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
3264 * The server can deal with SSH1_MSG_IGNORE, so
3265 * we can use the primary defence.
3267 int bottom, top, pwlen, i;
3270 pwlen = strlen(s->password);
3272 bottom = 0; /* zero length passwords are OK! :-) */
3275 bottom = pwlen & ~7;
3279 assert(pwlen >= bottom && pwlen <= top);
3281 randomstr = snewn(top + 1, char);
3283 for (i = bottom; i <= top; i++) {
3285 defer_packet(ssh, s->pwpkt_type,
3286 PKTT_PASSWORD, PKT_STR, s->password,
3287 PKTT_OTHER, PKT_END);
3289 for (j = 0; j < i; j++) {
3291 randomstr[j] = random_byte();
3292 } while (randomstr[j] == '\0');
3294 randomstr[i] = '\0';
3295 defer_packet(ssh, SSH1_MSG_IGNORE,
3296 PKT_STR, randomstr, PKT_END);
3299 logevent("Sending password with camouflage packets");
3300 ssh_pkt_defersend(ssh);
3303 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3305 * The server can't deal with SSH1_MSG_IGNORE
3306 * but can deal with padded passwords, so we
3307 * can use the secondary defence.
3313 len = strlen(s->password);
3314 if (len < sizeof(string)) {
3316 strcpy(string, s->password);
3317 len++; /* cover the zero byte */
3318 while (len < sizeof(string)) {
3319 string[len++] = (char) random_byte();
3324 logevent("Sending length-padded password");
3325 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3326 PKT_INT, len, PKT_DATA, ss, len,
3327 PKTT_OTHER, PKT_END);
3330 * The server has _both_
3331 * BUG_CHOKES_ON_SSH1_IGNORE and
3332 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3333 * therefore nothing we can do.
3336 len = strlen(s->password);
3337 logevent("Sending unpadded password");
3338 send_packet(ssh, s->pwpkt_type,
3339 PKTT_PASSWORD, PKT_INT, len,
3340 PKT_DATA, s->password, len,
3341 PKTT_OTHER, PKT_END);
3344 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3345 PKT_STR, s->password, PKTT_OTHER, PKT_END);
3348 logevent("Sent password");
3349 memset(s->password, 0, strlen(s->password));
3351 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3352 if (flags & FLAG_VERBOSE)
3353 c_write_str(ssh, "Access denied\r\n");
3354 logevent("Authentication refused");
3355 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
3356 bombout(("Strange packet received, type %d", ssh->pktin.type));
3361 logevent("Authentication successful");
3366 void sshfwd_close(struct ssh_channel *c)
3370 if (ssh->state != SSH_STATE_SESSION) {
3371 assert(ssh->state == SSH_STATE_CLOSED);
3375 if (c && !c->closes) {
3377 * If the channel's remoteid is -1, we have sent
3378 * CHANNEL_OPEN for this channel, but it hasn't even been
3379 * acknowledged by the server. So we must set a close flag
3380 * on it now, and then when the server acks the channel
3381 * open, we can close it then.
3383 if (((int)c->remoteid) != -1) {
3384 if (ssh->version == 1) {
3385 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3388 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
3389 ssh2_pkt_adduint32(ssh, c->remoteid);
3393 c->closes = 1; /* sent MSG_CLOSE */
3394 if (c->type == CHAN_X11) {
3396 logevent("Forwarded X11 connection terminated");
3397 } else if (c->type == CHAN_SOCKDATA ||
3398 c->type == CHAN_SOCKDATA_DORMANT) {
3400 logevent("Forwarded port closed");
3405 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3409 if (ssh->state != SSH_STATE_SESSION) {
3410 assert(ssh->state == SSH_STATE_CLOSED);
3414 if (ssh->version == 1) {
3415 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3416 PKT_INT, c->remoteid,
3418 PKT_INT, len, PKT_DATA, buf, len,
3419 PKTT_OTHER, PKT_END);
3421 * In SSH1 we can return 0 here - implying that forwarded
3422 * connections are never individually throttled - because
3423 * the only circumstance that can cause throttling will be
3424 * the whole SSH connection backing up, in which case
3425 * _everything_ will be throttled as a whole.
3429 ssh2_add_channel_data(c, buf, len);
3430 return ssh2_try_send(c);
3434 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3438 if (ssh->state != SSH_STATE_SESSION) {
3439 assert(ssh->state == SSH_STATE_CLOSED);
3443 if (ssh->version == 1) {
3444 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3445 c->v.v1.throttling = 0;
3446 ssh1_throttle(ssh, -1);
3449 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3453 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3455 crBegin(ssh->ssh1_protocol_crstate);
3459 while (!do_ssh1_login(ssh, in, inlen, ispkt)) {
3462 if (ssh->state == SSH_STATE_CLOSED)
3465 if (ssh->cfg.agentfwd && agent_exists()) {
3466 logevent("Requesting agent forwarding");
3467 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
3471 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3472 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3473 bombout(("Protocol confusion"));
3475 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3476 logevent("Agent forwarding refused");
3478 logevent("Agent forwarding enabled");
3479 ssh->agentfwd_enabled = TRUE;
3483 if (ssh->cfg.x11_forward) {
3484 char proto[20], data[64];
3485 logevent("Requesting X11 forwarding");
3486 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
3487 data, sizeof(data), ssh->cfg.x11_auth);
3488 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
3489 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3490 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3491 PKT_STR, proto, PKT_STR, data,
3492 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
3495 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3496 PKT_STR, proto, PKT_STR, data, PKT_END);
3501 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3502 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3503 bombout(("Protocol confusion"));
3505 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3506 logevent("X11 forwarding refused");
3508 logevent("X11 forwarding enabled");
3509 ssh->X11_fwd_enabled = TRUE;
3516 int sport,dport,sserv,dserv;
3517 char sports[256], dports[256], saddr[256], host[256];
3519 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3520 /* Add port forwardings. */
3521 ssh->portfwd_strptr = ssh->cfg.portfwd;
3522 while (*ssh->portfwd_strptr) {
3523 type = *ssh->portfwd_strptr++;
3526 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
3527 if (*ssh->portfwd_strptr == ':') {
3529 * We've seen a colon in the middle of the
3530 * source port number. This means that
3531 * everything we've seen until now is the
3532 * source _address_, so we'll move it into
3533 * saddr and start sports from the beginning
3536 ssh->portfwd_strptr++;
3538 strcpy(saddr, sports);
3541 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
3545 if (*ssh->portfwd_strptr == '\t')
3546 ssh->portfwd_strptr++;
3548 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
3549 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
3552 if (*ssh->portfwd_strptr == ':')
3553 ssh->portfwd_strptr++;
3555 while (*ssh->portfwd_strptr) {
3556 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
3559 ssh->portfwd_strptr++;
3560 dport = atoi(dports);
3564 dport = net_service_lookup(dports);
3566 logeventf(ssh, "Service lookup failed for"
3567 " destination port \"%s\"", dports);
3571 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
3573 ssh->portfwd_strptr++; /* eat the NUL and move to next one */
3575 sport = atoi(sports);
3579 sport = net_service_lookup(sports);
3581 logeventf(ssh, "Service lookup failed for source"
3582 " port \"%s\"", sports);
3585 if (sport && dport) {
3586 /* Set up a description of the source port. */
3587 char *sportdesc = dupprintf("%.*s%.*s%.*s%.*s%d%.*s",
3588 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3589 (int)(*saddr?1:0), ":",
3590 (int)(sserv ? strlen(sports) : 0), sports,
3591 sserv, "(", sport, sserv, ")");
3593 /* Verbose description of the destination port */
3594 char *dportdesc = dupprintf("%s:%.*s%.*s%d%.*s",
3596 (int)(dserv ? strlen(dports) : 0), dports,
3597 dserv, "(", dport, dserv, ")");
3598 const char *err = pfd_addforward(host, dport,
3599 *saddr ? saddr : NULL,
3600 sport, ssh, &ssh->cfg);
3602 logeventf(ssh, "Local port %s forward to %s"
3603 " failed: %s", sportdesc, dportdesc, err);
3605 logeventf(ssh, "Local port %s forwarding to %s",
3606 sportdesc, dportdesc);
3609 } else if (type == 'D') {
3610 const char *err = pfd_addforward(NULL, -1,
3611 *saddr ? saddr : NULL,
3612 sport, ssh, &ssh->cfg);
3614 logeventf(ssh, "Local port %s SOCKS dynamic forward"
3615 " setup failed: %s", sportdesc, err);
3617 logeventf(ssh, "Local port %s doing SOCKS"
3618 " dynamic forwarding", sportdesc);
3621 struct ssh_rportfwd *pf;
3622 pf = snew(struct ssh_rportfwd);
3623 strcpy(pf->dhost, host);
3627 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
3630 if (add234(ssh->rportfwds, pf) != pf) {
3632 "Duplicate remote port forwarding to %s:%d",
3636 logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s"
3637 " forward to %s:%.*s%.*s%d%.*s",
3638 (int)(sserv ? strlen(sports) : 0), sports,
3639 sserv, "(", sport, sserv, ")",
3641 (int)(dserv ? strlen(dports) : 0), dports,
3642 dserv, "(", dport, dserv, ")");
3643 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
3651 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3652 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3653 bombout(("Protocol confusion"));
3655 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3656 c_write_str(ssh, "Server refused port"
3659 logevent("Remote port forwarding enabled");
3667 if (!ssh->cfg.nopty) {
3668 /* Unpick the terminal-speed string. */
3669 /* XXX perhaps we should allow no speeds to be sent. */
3670 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
3671 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
3672 /* Send the pty request. */
3673 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
3674 PKT_STR, ssh->cfg.termtype,
3675 PKT_INT, ssh->term_height,
3676 PKT_INT, ssh->term_width,
3677 PKT_INT, 0, PKT_INT, 0, /* width,height in pixels */
3678 PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */
3679 PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */
3680 PKT_CHAR, 0, PKT_END);
3681 ssh->state = SSH_STATE_INTERMED;
3685 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3686 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3687 bombout(("Protocol confusion"));
3689 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3690 c_write_str(ssh, "Server refused to allocate pty\r\n");
3691 ssh->editing = ssh->echoing = 1;
3693 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
3694 ssh->ospeed, ssh->ispeed);
3696 ssh->editing = ssh->echoing = 1;
3699 if (ssh->cfg.compression) {
3700 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
3704 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3705 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3706 bombout(("Protocol confusion"));
3708 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3709 c_write_str(ssh, "Server refused to compress\r\n");
3711 logevent("Started compression");
3712 ssh->v1_compressing = TRUE;
3713 ssh->cs_comp_ctx = zlib_compress_init();
3714 logevent("Initialised zlib (RFC1950) compression");
3715 ssh->sc_comp_ctx = zlib_decompress_init();
3716 logevent("Initialised zlib (RFC1950) decompression");
3720 * Start the shell or command.
3722 * Special case: if the first-choice command is an SSH2
3723 * subsystem (hence not usable here) and the second choice
3724 * exists, we fall straight back to that.
3727 char *cmd = ssh->cfg.remote_cmd_ptr;
3729 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
3730 cmd = ssh->cfg.remote_cmd_ptr2;
3731 ssh->fallback_cmd = TRUE;
3734 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
3736 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
3737 logevent("Started session");
3740 ssh->state = SSH_STATE_SESSION;
3741 if (ssh->size_needed)
3742 ssh_size(ssh, ssh->term_width, ssh->term_height);
3743 if (ssh->eof_needed)
3744 ssh_special(ssh, TS_EOF);
3747 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
3749 ssh->channels = newtree234(ssh_channelcmp);
3753 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
3754 ssh->pktin.type == SSH1_SMSG_STDERR_DATA) {
3756 int stringlen, bufsize;
3758 ssh_pkt_getstring(ssh, &string, &stringlen);
3759 if (string == NULL) {
3760 bombout(("Incoming terminal data packet was badly formed"));
3765 from_backend(ssh->frontend,
3766 ssh->pktin.type == SSH1_SMSG_STDERR_DATA,
3768 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3769 ssh->v1_stdout_throttling = 1;
3770 ssh1_throttle(ssh, +1);
3772 } else if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
3773 ssh_closing((Plug)ssh, NULL, 0, 0);
3774 logevent("Received disconnect request");
3776 } else if (ssh->pktin.type == SSH1_SMSG_X11_OPEN) {
3777 /* Remote side is trying to open a channel to talk to our
3778 * X-Server. Give them back a local channel number. */
3779 struct ssh_channel *c;
3780 int remoteid = ssh_pkt_getuint32(ssh);
3782 logevent("Received X11 connect request");
3783 /* Refuse if X11 forwarding is disabled. */
3784 if (!ssh->X11_fwd_enabled) {
3785 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3786 PKT_INT, remoteid, PKT_END);
3787 logevent("Rejected X11 connect request");
3789 c = snew(struct ssh_channel);
3792 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
3793 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
3794 logevent("Opening X11 forward connection failed");
3796 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3797 PKT_INT, remoteid, PKT_END);
3800 ("Opening X11 forward connection succeeded");
3801 c->remoteid = remoteid;
3802 c->localid = alloc_channel_id(ssh);
3804 c->v.v1.throttling = 0;
3805 c->type = CHAN_X11; /* identify channel type */
3806 add234(ssh->channels, c);
3807 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3808 PKT_INT, c->remoteid, PKT_INT,
3809 c->localid, PKT_END);
3810 logevent("Opened X11 forward channel");
3813 } else if (ssh->pktin.type == SSH1_SMSG_AGENT_OPEN) {
3814 /* Remote side is trying to open a channel to talk to our
3815 * agent. Give them back a local channel number. */
3816 struct ssh_channel *c;
3817 int remoteid = ssh_pkt_getuint32(ssh);
3819 /* Refuse if agent forwarding is disabled. */
3820 if (!ssh->agentfwd_enabled) {
3821 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3822 PKT_INT, remoteid, PKT_END);
3824 c = snew(struct ssh_channel);
3826 c->remoteid = remoteid;
3827 c->localid = alloc_channel_id(ssh);
3829 c->v.v1.throttling = 0;
3830 c->type = CHAN_AGENT; /* identify channel type */
3831 c->u.a.lensofar = 0;
3832 add234(ssh->channels, c);
3833 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3834 PKT_INT, c->remoteid, PKT_INT, c->localid,
3837 } else if (ssh->pktin.type == SSH1_MSG_PORT_OPEN) {
3838 /* Remote side is trying to open a channel to talk to a
3839 * forwarded port. Give them back a local channel number. */
3840 struct ssh_channel *c;
3841 struct ssh_rportfwd pf;
3844 char *host, buf[1024];
3846 c = snew(struct ssh_channel);
3849 remoteid = ssh_pkt_getuint32(ssh);
3850 ssh_pkt_getstring(ssh, &host, &hostsize);
3851 port = ssh_pkt_getuint32(ssh);
3853 if (hostsize >= lenof(pf.dhost))
3854 hostsize = lenof(pf.dhost)-1;
3855 memcpy(pf.dhost, host, hostsize);
3856 pf.dhost[hostsize] = '\0';
3859 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
3860 sprintf(buf, "Rejected remote port open request for %s:%d",
3863 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3864 PKT_INT, remoteid, PKT_END);
3866 sprintf(buf, "Received remote port open request for %s:%d",
3869 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
3873 sprintf(buf, "Port open failed: %s", e);
3876 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3877 PKT_INT, remoteid, PKT_END);
3879 c->remoteid = remoteid;
3880 c->localid = alloc_channel_id(ssh);
3882 c->v.v1.throttling = 0;
3883 c->type = CHAN_SOCKDATA; /* identify channel type */
3884 add234(ssh->channels, c);
3885 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3886 PKT_INT, c->remoteid, PKT_INT,
3887 c->localid, PKT_END);
3888 logevent("Forwarded port opened successfully");
3892 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3893 unsigned int remoteid = ssh_pkt_getuint32(ssh);
3894 unsigned int localid = ssh_pkt_getuint32(ssh);
3895 struct ssh_channel *c;
3897 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3898 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3899 c->remoteid = localid;
3900 c->type = CHAN_SOCKDATA;
3901 c->v.v1.throttling = 0;
3902 pfd_confirm(c->u.pfd.s);
3905 if (c && c->closes) {
3907 * We have a pending close on this channel,
3908 * which we decided on before the server acked
3909 * the channel open. So now we know the
3910 * remoteid, we can close it again.
3912 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3913 PKT_INT, c->remoteid, PKT_END);
3916 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3917 unsigned int remoteid = ssh_pkt_getuint32(ssh);
3918 struct ssh_channel *c;
3920 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3921 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3922 logevent("Forwarded connection refused by server");
3923 pfd_close(c->u.pfd.s);
3924 del234(ssh->channels, c);
3928 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3929 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
3930 /* Remote side closes a channel. */
3931 unsigned i = ssh_pkt_getuint32(ssh);
3932 struct ssh_channel *c;
3933 c = find234(ssh->channels, &i, ssh_channelfind);
3934 if (c && ((int)c->remoteid) != -1) {
3937 (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3939 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3940 logevent("Forwarded X11 connection terminated");
3941 assert(c->u.x11.s != NULL);
3942 x11_close(c->u.x11.s);
3945 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3946 logevent("Forwarded port closed");
3947 assert(c->u.pfd.s != NULL);
3948 pfd_close(c->u.pfd.s);
3952 c->closes |= (closetype << 2); /* seen this message */
3953 if (!(c->closes & closetype)) {
3954 send_packet(ssh, ssh->pktin.type, PKT_INT, c->remoteid,
3956 c->closes |= closetype; /* sent it too */
3959 if (c->closes == 15) {
3960 del234(ssh->channels, c);
3964 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
3965 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" :
3966 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3970 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) {
3971 /* Data sent down one of our channels. */
3972 int i = ssh_pkt_getuint32(ssh);
3975 struct ssh_channel *c;
3977 ssh_pkt_getstring(ssh, &p, &len);
3979 c = find234(ssh->channels, &i, ssh_channelfind);
3984 bufsize = x11_send(c->u.x11.s, p, len);
3987 bufsize = pfd_send(c->u.pfd.s, p, len);
3990 /* Data for an agent message. Buffer it. */
3992 if (c->u.a.lensofar < 4) {
3993 int l = min(4 - c->u.a.lensofar, len);
3994 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3998 c->u.a.lensofar += l;
4000 if (c->u.a.lensofar == 4) {
4002 4 + GET_32BIT(c->u.a.msglen);
4003 c->u.a.message = snewn(c->u.a.totallen,
4005 memcpy(c->u.a.message, c->u.a.msglen, 4);
4007 if (c->u.a.lensofar >= 4 && len > 0) {
4009 min(c->u.a.totallen - c->u.a.lensofar,
4011 memcpy(c->u.a.message + c->u.a.lensofar, p,
4015 c->u.a.lensofar += l;
4017 if (c->u.a.lensofar == c->u.a.totallen) {
4020 if (agent_query(c->u.a.message,
4023 ssh_agentf_callback, c))
4024 ssh_agentf_callback(c, reply, replylen);
4025 sfree(c->u.a.message);
4026 c->u.a.lensofar = 0;
4029 bufsize = 0; /* agent channels never back up */
4032 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4033 c->v.v1.throttling = 1;
4034 ssh1_throttle(ssh, +1);
4037 } else if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
4038 /* may be from EXEC_SHELL on some servers */
4039 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
4040 /* may be from EXEC_SHELL on some servers
4041 * if no pty is available or in other odd cases. Ignore */
4042 } else if (ssh->pktin.type == SSH1_SMSG_EXIT_STATUS) {
4044 ssh->exitcode = ssh_pkt_getuint32(ssh);
4045 sprintf(buf, "Server sent command exit status %d",
4048 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4050 * In case `helpful' firewalls or proxies tack
4051 * extra human-readable text on the end of the
4052 * session which we might mistake for another
4053 * encrypted packet, we close the session once
4054 * we've sent EXIT_CONFIRMATION.
4056 ssh_closing((Plug)ssh, NULL, 0, 0);
4059 bombout(("Strange packet received: type %d", ssh->pktin.type));
4064 int len = min(inlen, 512);
4065 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4066 PKT_INT, len, PKT_DATA, in, len,
4067 PKTT_OTHER, PKT_END);
4078 * Utility routine for decoding comma-separated strings in KEXINIT.
4080 static int in_commasep_string(char *needle, char *haystack, int haylen)
4083 if (!needle || !haystack) /* protect against null pointers */
4085 needlen = strlen(needle);
4088 * Is it at the start of the string?
4090 if (haylen >= needlen && /* haystack is long enough */
4091 !memcmp(needle, haystack, needlen) && /* initial match */
4092 (haylen == needlen || haystack[needlen] == ',')
4093 /* either , or EOS follows */
4097 * If not, search for the next comma and resume after that.
4098 * If no comma found, terminate.
4100 while (haylen > 0 && *haystack != ',')
4101 haylen--, haystack++;
4104 haylen--, haystack++; /* skip over comma itself */
4109 * SSH2 key creation method.
4111 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4112 unsigned char *sessid, char chr,
4113 unsigned char *keyspace)
4116 /* First 20 bytes. */
4118 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4120 SHA_Bytes(&s, H, 20);
4121 SHA_Bytes(&s, &chr, 1);
4122 SHA_Bytes(&s, sessid, 20);
4123 SHA_Final(&s, keyspace);
4124 /* Next 20 bytes. */
4126 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4128 SHA_Bytes(&s, H, 20);
4129 SHA_Bytes(&s, keyspace, 20);
4130 SHA_Final(&s, keyspace + 20);
4134 * Handle the SSH2 transport layer.
4136 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
4138 struct do_ssh2_transport_state {
4139 int nbits, pbits, warn;
4140 Bignum p, g, e, f, K;
4141 int kex_init_value, kex_reply_value;
4142 const struct ssh_mac **maclist;
4144 const struct ssh2_cipher *cscipher_tobe;
4145 const struct ssh2_cipher *sccipher_tobe;
4146 const struct ssh_mac *csmac_tobe;
4147 const struct ssh_mac *scmac_tobe;
4148 const struct ssh_compress *cscomp_tobe;
4149 const struct ssh_compress *sccomp_tobe;
4150 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4151 int hostkeylen, siglen;
4152 void *hkey; /* actual host key */
4153 unsigned char exchange_hash[20];
4154 int n_preferred_ciphers;
4155 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4156 const struct ssh_compress *preferred_comp;
4159 crState(do_ssh2_transport_state);
4161 crBegin(ssh->do_ssh2_transport_crstate);
4163 s->cscipher_tobe = s->sccipher_tobe = NULL;
4164 s->csmac_tobe = s->scmac_tobe = NULL;
4165 s->cscomp_tobe = s->sccomp_tobe = NULL;
4173 * Set up the preferred ciphers. (NULL => warn below here)
4175 s->n_preferred_ciphers = 0;
4176 for (i = 0; i < CIPHER_MAX; i++) {
4177 switch (ssh->cfg.ssh_cipherlist[i]) {
4178 case CIPHER_BLOWFISH:
4179 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
4182 if (ssh->cfg.ssh2_des_cbc) {
4183 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
4187 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
4190 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
4193 /* Flag for later. Don't bother if it's the last in
4195 if (i < CIPHER_MAX - 1) {
4196 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
4204 * Set up preferred compression.
4206 if (ssh->cfg.compression)
4207 s->preferred_comp = &ssh_zlib;
4209 s->preferred_comp = &ssh_comp_none;
4212 * Be prepared to work around the buggy MAC problem.
4214 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4215 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
4217 s->maclist = macs, s->nmacs = lenof(macs);
4221 int i, j, cipherstr_started;
4224 * Construct and send our key exchange packet.
4226 ssh2_pkt_init(ssh, SSH2_MSG_KEXINIT);
4227 for (i = 0; i < 16; i++)
4228 ssh2_pkt_addbyte(ssh, (unsigned char) random_byte());
4229 /* List key exchange algorithms. */
4230 ssh2_pkt_addstring_start(ssh);
4231 for (i = 0; i < lenof(kex_algs); i++) {
4232 if (kex_algs[i] == &ssh_diffiehellman_gex &&
4233 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
4235 ssh2_pkt_addstring_str(ssh, kex_algs[i]->name);
4236 if (i < lenof(kex_algs) - 1)
4237 ssh2_pkt_addstring_str(ssh, ",");
4239 /* List server host key algorithms. */
4240 ssh2_pkt_addstring_start(ssh);
4241 for (i = 0; i < lenof(hostkey_algs); i++) {
4242 ssh2_pkt_addstring_str(ssh, hostkey_algs[i]->name);
4243 if (i < lenof(hostkey_algs) - 1)
4244 ssh2_pkt_addstring_str(ssh, ",");
4246 /* List client->server encryption algorithms. */
4247 ssh2_pkt_addstring_start(ssh);
4248 cipherstr_started = 0;
4249 for (i = 0; i < s->n_preferred_ciphers; i++) {
4250 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4251 if (!c) continue; /* warning flag */
4252 for (j = 0; j < c->nciphers; j++) {
4253 if (cipherstr_started)
4254 ssh2_pkt_addstring_str(ssh, ",");
4255 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
4256 cipherstr_started = 1;
4259 /* List server->client encryption algorithms. */
4260 ssh2_pkt_addstring_start(ssh);
4261 cipherstr_started = 0;
4262 for (i = 0; i < s->n_preferred_ciphers; i++) {
4263 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4264 if (!c) continue; /* warning flag */
4265 for (j = 0; j < c->nciphers; j++) {
4266 if (cipherstr_started)
4267 ssh2_pkt_addstring_str(ssh, ",");
4268 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
4269 cipherstr_started = 1;
4272 /* List client->server MAC algorithms. */
4273 ssh2_pkt_addstring_start(ssh);
4274 for (i = 0; i < s->nmacs; i++) {
4275 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
4276 if (i < s->nmacs - 1)
4277 ssh2_pkt_addstring_str(ssh, ",");
4279 /* List server->client MAC algorithms. */
4280 ssh2_pkt_addstring_start(ssh);
4281 for (i = 0; i < s->nmacs; i++) {
4282 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
4283 if (i < s->nmacs - 1)
4284 ssh2_pkt_addstring_str(ssh, ",");
4286 /* List client->server compression algorithms. */
4287 ssh2_pkt_addstring_start(ssh);
4288 assert(lenof(compressions) > 1);
4289 ssh2_pkt_addstring_str(ssh, s->preferred_comp->name);
4290 for (i = 0; i < lenof(compressions); i++) {
4291 const struct ssh_compress *c = compressions[i];
4292 if (c != s->preferred_comp) {
4293 ssh2_pkt_addstring_str(ssh, ",");
4294 ssh2_pkt_addstring_str(ssh, c->name);
4297 /* List server->client compression algorithms. */
4298 ssh2_pkt_addstring_start(ssh);
4299 assert(lenof(compressions) > 1);
4300 ssh2_pkt_addstring_str(ssh, s->preferred_comp->name);
4301 for (i = 0; i < lenof(compressions); i++) {
4302 const struct ssh_compress *c = compressions[i];
4303 if (c != s->preferred_comp) {
4304 ssh2_pkt_addstring_str(ssh, ",");
4305 ssh2_pkt_addstring_str(ssh, c->name);
4308 /* List client->server languages. Empty list. */
4309 ssh2_pkt_addstring_start(ssh);
4310 /* List server->client languages. Empty list. */
4311 ssh2_pkt_addstring_start(ssh);
4312 /* First KEX packet does _not_ follow, because we're not that brave. */
4313 ssh2_pkt_addbool(ssh, FALSE);
4315 ssh2_pkt_adduint32(ssh, 0);
4318 ssh->exhash = ssh->exhashbase;
4319 sha_string(&ssh->exhash, ssh->pktout.data + 5, ssh->pktout.length - 5);
4325 if (ssh->pktin.length > 5)
4326 sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5);
4329 * Now examine the other side's KEXINIT to see what we're up
4336 if (ssh->pktin.type != SSH2_MSG_KEXINIT) {
4337 bombout(("expected key exchange packet from server"));
4341 ssh->hostkey = NULL;
4342 s->cscipher_tobe = NULL;
4343 s->sccipher_tobe = NULL;
4344 s->csmac_tobe = NULL;
4345 s->scmac_tobe = NULL;
4346 s->cscomp_tobe = NULL;
4347 s->sccomp_tobe = NULL;
4348 ssh->pktin.savedpos += 16; /* skip garbage cookie */
4349 ssh_pkt_getstring(ssh, &str, &len); /* key exchange algorithms */
4350 for (i = 0; i < lenof(kex_algs); i++) {
4351 if (kex_algs[i] == &ssh_diffiehellman_gex &&
4352 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
4354 if (in_commasep_string(kex_algs[i]->name, str, len)) {
4355 ssh->kex = kex_algs[i];
4359 ssh_pkt_getstring(ssh, &str, &len); /* host key algorithms */
4360 for (i = 0; i < lenof(hostkey_algs); i++) {
4361 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
4362 ssh->hostkey = hostkey_algs[i];
4366 ssh_pkt_getstring(ssh, &str, &len); /* client->server cipher */
4368 for (i = 0; i < s->n_preferred_ciphers; i++) {
4369 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4373 for (j = 0; j < c->nciphers; j++) {
4374 if (in_commasep_string(c->list[j]->name, str, len)) {
4375 s->cscipher_tobe = c->list[j];
4380 if (s->cscipher_tobe) {
4382 askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
4386 if (!s->cscipher_tobe) {
4387 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
4388 str ? str : "(null)"));
4392 ssh_pkt_getstring(ssh, &str, &len); /* server->client cipher */
4394 for (i = 0; i < s->n_preferred_ciphers; i++) {
4395 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4399 for (j = 0; j < c->nciphers; j++) {
4400 if (in_commasep_string(c->list[j]->name, str, len)) {
4401 s->sccipher_tobe = c->list[j];
4406 if (s->sccipher_tobe) {
4408 askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
4412 if (!s->sccipher_tobe) {
4413 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
4414 str ? str : "(null)"));
4418 ssh_pkt_getstring(ssh, &str, &len); /* client->server mac */
4419 for (i = 0; i < s->nmacs; i++) {
4420 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4421 s->csmac_tobe = s->maclist[i];
4425 ssh_pkt_getstring(ssh, &str, &len); /* server->client mac */
4426 for (i = 0; i < s->nmacs; i++) {
4427 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4428 s->scmac_tobe = s->maclist[i];
4432 ssh_pkt_getstring(ssh, &str, &len); /* client->server compression */
4433 for (i = 0; i < lenof(compressions) + 1; i++) {
4434 const struct ssh_compress *c =
4435 i == 0 ? s->preferred_comp : compressions[i - 1];
4436 if (in_commasep_string(c->name, str, len)) {
4441 ssh_pkt_getstring(ssh, &str, &len); /* server->client compression */
4442 for (i = 0; i < lenof(compressions) + 1; i++) {
4443 const struct ssh_compress *c =
4444 i == 0 ? s->preferred_comp : compressions[i - 1];
4445 if (in_commasep_string(c->name, str, len)) {
4453 * Work out the number of bits of key we will need from the key
4454 * exchange. We start with the maximum key length of either
4460 csbits = s->cscipher_tobe->keylen;
4461 scbits = s->sccipher_tobe->keylen;
4462 s->nbits = (csbits > scbits ? csbits : scbits);
4464 /* The keys only have 160-bit entropy, since they're based on
4465 * a SHA-1 hash. So cap the key size at 160 bits. */
4470 * If we're doing Diffie-Hellman group exchange, start by
4471 * requesting a group.
4473 if (ssh->kex == &ssh_diffiehellman_gex) {
4474 logevent("Doing Diffie-Hellman group exchange");
4475 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
4477 * Work out how big a DH group we will need to allow that
4480 s->pbits = 512 << ((s->nbits - 1) / 64);
4481 ssh2_pkt_init(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST);
4482 ssh2_pkt_adduint32(ssh, s->pbits);
4486 if (ssh->pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
4487 bombout(("expected key exchange group packet from server"));
4490 s->p = ssh2_pkt_getmp(ssh);
4491 s->g = ssh2_pkt_getmp(ssh);
4492 ssh->kex_ctx = dh_setup_group(s->p, s->g);
4493 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
4494 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
4496 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
4497 ssh->kex_ctx = dh_setup_group1();
4498 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
4499 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
4502 logevent("Doing Diffie-Hellman key exchange");
4504 * Now generate and send e for Diffie-Hellman.
4506 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
4507 ssh2_pkt_init(ssh, s->kex_init_value);
4508 ssh2_pkt_addmp(ssh, s->e);
4512 if (ssh->pktin.type != s->kex_reply_value) {
4513 bombout(("expected key exchange reply packet from server"));
4516 ssh_pkt_getstring(ssh, &s->hostkeydata, &s->hostkeylen);
4517 s->f = ssh2_pkt_getmp(ssh);
4518 ssh_pkt_getstring(ssh, &s->sigdata, &s->siglen);
4520 s->K = dh_find_K(ssh->kex_ctx, s->f);
4522 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4523 if (ssh->kex == &ssh_diffiehellman_gex) {
4524 sha_uint32(&ssh->exhash, s->pbits);
4525 sha_mpint(&ssh->exhash, s->p);
4526 sha_mpint(&ssh->exhash, s->g);
4528 sha_mpint(&ssh->exhash, s->e);
4529 sha_mpint(&ssh->exhash, s->f);
4530 sha_mpint(&ssh->exhash, s->K);
4531 SHA_Final(&ssh->exhash, s->exchange_hash);
4533 dh_cleanup(ssh->kex_ctx);
4534 ssh->kex_ctx = NULL;
4537 debug(("Exchange hash is:\n"));
4538 dmemdump(s->exchange_hash, 20);
4541 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4543 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
4544 (char *)s->exchange_hash, 20)) {
4545 bombout(("Server's host key did not match the signature supplied"));
4550 * Authenticate remote host: verify host key. (We've already
4551 * checked the signature of the exchange hash.)
4553 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4554 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
4555 verify_ssh_host_key(ssh->frontend,
4556 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
4557 s->keystr, s->fingerprint);
4558 if (s->first_kex) { /* don't bother logging this in rekeys */
4559 logevent("Host key fingerprint is:");
4560 logevent(s->fingerprint);
4562 sfree(s->fingerprint);
4564 ssh->hostkey->freekey(s->hkey);
4567 * Send SSH2_MSG_NEWKEYS.
4569 ssh2_pkt_init(ssh, SSH2_MSG_NEWKEYS);
4573 * Expect SSH2_MSG_NEWKEYS from server.
4576 if (ssh->pktin.type != SSH2_MSG_NEWKEYS) {
4577 bombout(("expected new-keys packet from server"));
4582 * Create and initialise session keys.
4584 if (ssh->cs_cipher_ctx)
4585 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
4586 ssh->cscipher = s->cscipher_tobe;
4587 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
4589 if (ssh->sc_cipher_ctx)
4590 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
4591 ssh->sccipher = s->sccipher_tobe;
4592 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
4594 if (ssh->cs_mac_ctx)
4595 ssh->csmac->free_context(ssh->cs_mac_ctx);
4596 ssh->csmac = s->csmac_tobe;
4597 ssh->cs_mac_ctx = ssh->csmac->make_context();
4599 if (ssh->sc_mac_ctx)
4600 ssh->scmac->free_context(ssh->sc_mac_ctx);
4601 ssh->scmac = s->scmac_tobe;
4602 ssh->sc_mac_ctx = ssh->scmac->make_context();
4604 if (ssh->cs_comp_ctx)
4605 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
4606 ssh->cscomp = s->cscomp_tobe;
4607 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4609 if (ssh->sc_comp_ctx)
4610 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
4611 ssh->sccomp = s->sccomp_tobe;
4612 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4615 * Set IVs after keys. Here we use the exchange hash from the
4616 * _first_ key exchange.
4619 unsigned char keyspace[40];
4621 memcpy(ssh->v2_session_id, s->exchange_hash,
4622 sizeof(s->exchange_hash));
4623 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
4624 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
4625 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
4626 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
4627 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
4628 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
4629 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
4630 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
4631 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
4632 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
4633 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
4634 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
4636 logeventf(ssh, "Initialised %.200s client->server encryption",
4637 ssh->cscipher->text_name);
4638 logeventf(ssh, "Initialised %.200s server->client encryption",
4639 ssh->sccipher->text_name);
4640 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
4641 ssh->csmac->text_name);
4642 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
4643 ssh->scmac->text_name);
4644 if (ssh->cscomp->text_name)
4645 logeventf(ssh, "Initialised %s compression",
4646 ssh->cscomp->text_name);
4647 if (ssh->sccomp->text_name)
4648 logeventf(ssh, "Initialised %s decompression",
4649 ssh->sccomp->text_name);
4652 if (ssh->kex == &ssh_diffiehellman_gex) {
4658 * If this is the first key exchange phase, we must pass the
4659 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4660 * wants to see it but because it will need time to initialise
4661 * itself before it sees an actual packet. In subsequent key
4662 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4663 * it would only confuse the layer above.
4665 if (!s->first_kex) {
4671 * Now we're encrypting. Begin returning 1 to the protocol main
4672 * function so that other things can run on top of the
4673 * transport. If we ever see a KEXINIT, we must go back to the
4676 while (!(ispkt && ssh->pktin.type == SSH2_MSG_KEXINIT)) {
4679 logevent("Server initiated key re-exchange");
4680 goto begin_key_exchange;
4686 * Add data to an SSH2 channel output buffer.
4688 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4691 bufchain_add(&c->v.v2.outbuffer, buf, len);
4695 * Attempt to send data on an SSH2 channel.
4697 static int ssh2_try_send(struct ssh_channel *c)
4701 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4704 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4705 if ((unsigned)len > c->v.v2.remwindow)
4706 len = c->v.v2.remwindow;
4707 if ((unsigned)len > c->v.v2.remmaxpkt)
4708 len = c->v.v2.remmaxpkt;
4709 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_DATA);
4710 ssh2_pkt_adduint32(ssh, c->remoteid);
4711 dont_log_data(ssh, PKTLOG_OMIT);
4712 ssh2_pkt_addstring_start(ssh);
4713 ssh2_pkt_addstring_data(ssh, data, len);
4714 end_log_omission(ssh);
4716 bufchain_consume(&c->v.v2.outbuffer, len);
4717 c->v.v2.remwindow -= len;
4721 * After having sent as much data as we can, return the amount
4724 return bufchain_size(&c->v.v2.outbuffer);
4728 * Potentially enlarge the window on an SSH2 channel.
4730 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4735 * Never send WINDOW_ADJUST for a channel that the remote side
4736 * already thinks it's closed; there's no point, since it won't
4737 * be sending any more data anyway.
4742 if (newwin > c->v.v2.locwindow) {
4743 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4744 ssh2_pkt_adduint32(ssh, c->remoteid);
4745 ssh2_pkt_adduint32(ssh, newwin - c->v.v2.locwindow);
4747 c->v.v2.locwindow = newwin;
4752 * Handle the SSH2 userauth and connection layers.
4754 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
4756 struct do_ssh2_authconn_state {
4758 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4760 AUTH_KEYBOARD_INTERACTIVE
4764 AUTH_TYPE_PUBLICKEY,
4765 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4766 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4768 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4769 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4771 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4772 int tried_pubkey_config, tried_agent, tried_keyb_inter;
4773 int kbd_inter_running;
4775 int num_prompts, curr_prompt, echo;
4780 void *publickey_blob;
4781 int publickey_bloblen;
4782 unsigned char request[5], *response, *p;
4786 char *pkblob, *alg, *commentp;
4787 int pklen, alglen, commentlen;
4788 int siglen, retlen, len;
4789 char *q, *agentreq, *ret;
4791 int num_env, env_left, env_ok;
4793 crState(do_ssh2_authconn_state);
4795 crBegin(ssh->do_ssh2_authconn_crstate);
4798 * Request userauth protocol, and await a response to it.
4800 ssh2_pkt_init(ssh, SSH2_MSG_SERVICE_REQUEST);
4801 ssh2_pkt_addstring(ssh, "ssh-userauth");
4803 crWaitUntilV(ispkt);
4804 if (ssh->pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
4805 bombout(("Server refused user authentication protocol"));
4810 * We repeat this whole loop, including the username prompt,
4811 * until we manage a successful authentication. If the user
4812 * types the wrong _password_, they can be sent back to the
4813 * beginning to try another username, if this is configured on.
4814 * (If they specify a username in the config, they are never
4815 * asked, even if they do give a wrong password.)
4817 * I think this best serves the needs of
4819 * - the people who have no configuration, no keys, and just
4820 * want to try repeated (username,password) pairs until they
4821 * type both correctly
4823 * - people who have keys and configuration but occasionally
4824 * need to fall back to passwords
4826 * - people with a key held in Pageant, who might not have
4827 * logged in to a particular machine before; so they want to
4828 * type a username, and then _either_ their key will be
4829 * accepted, _or_ they will type a password. If they mistype
4830 * the username they will want to be able to get back and
4833 s->username[0] = '\0';
4834 s->got_username = FALSE;
4839 if (s->got_username && !ssh->cfg.change_username) {
4841 * We got a username last time round this loop, and
4842 * with change_username turned off we don't try to get
4845 } else if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
4846 if (ssh_get_line && !ssh_getline_pw_only) {
4847 if (!ssh_get_line("login as: ",
4848 s->username, sizeof(s->username), FALSE)) {
4850 * get_line failed to get a username.
4853 logevent("No username provided. Abandoning session.");
4854 ssh_closing((Plug)ssh, NULL, 0, 0);
4858 int ret; /* need not be saved across crReturn */
4859 c_write_str(ssh, "login as: ");
4861 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
4863 crWaitUntilV(!ispkt);
4864 ret = process_userpass_input(ssh, in, inlen);
4868 c_write_str(ssh, "\r\n");
4870 s->username[strcspn(s->username, "\n\r")] = '\0';
4873 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
4874 s->username[sizeof(s->username)-1] = '\0';
4875 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
4876 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
4877 c_write_str(ssh, stuff);
4881 s->got_username = TRUE;
4884 * Send an authentication request using method "none": (a)
4885 * just in case it succeeds, and (b) so that we know what
4886 * authentication methods we can usefully try next.
4888 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4890 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4891 ssh2_pkt_addstring(ssh, s->username);
4892 ssh2_pkt_addstring(ssh, "ssh-connection");/* service requested */
4893 ssh2_pkt_addstring(ssh, "none"); /* method */
4895 s->type = AUTH_TYPE_NONE;
4897 s->we_are_in = FALSE;
4899 s->tried_pubkey_config = FALSE;
4900 s->tried_agent = FALSE;
4901 s->tried_keyb_inter = FALSE;
4902 s->kbd_inter_running = FALSE;
4903 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
4904 if (!filename_is_null(ssh->cfg.keyfile)) {
4906 logeventf(ssh, "Reading private key file \"%.150s\"",
4907 filename_to_str(&ssh->cfg.keyfile));
4908 keytype = key_type(&ssh->cfg.keyfile);
4909 if (keytype == SSH_KEYTYPE_SSH2) {
4911 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
4912 &s->publickey_bloblen, NULL);
4915 logeventf(ssh, "Unable to use this key file (%s)",
4916 key_type_to_str(keytype));
4917 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4919 filename_to_str(&ssh->cfg.keyfile),
4920 key_type_to_str(keytype));
4921 c_write_str(ssh, msgbuf);
4923 s->publickey_blob = NULL;
4926 s->publickey_blob = NULL;
4930 * Wait for the result of the last authentication request.
4933 crWaitUntilV(ispkt);
4934 while (ssh->pktin.type == SSH2_MSG_USERAUTH_BANNER) {
4938 * Don't show the banner if we're operating in
4939 * non-verbose non-interactive mode. (It's probably
4940 * a script, which means nobody will read the
4941 * banner _anyway_, and moreover the printing of
4942 * the banner will screw up processing on the
4943 * output of (say) plink.)
4945 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
4946 ssh_pkt_getstring(ssh, &banner, &size);
4948 c_write_untrusted(ssh, banner, size);
4950 crWaitUntilV(ispkt);
4952 if (ssh->pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
4953 logevent("Access granted");
4954 s->we_are_in = TRUE;
4958 if (s->kbd_inter_running &&
4959 ssh->pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
4961 * This is either a further set-of-prompts packet
4962 * in keyboard-interactive authentication, or it's
4963 * the same one and we came back here with `gotit'
4964 * set. In the former case, we must reset the
4965 * curr_prompt variable.
4969 } else if (ssh->pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
4970 bombout(("Strange packet received during authentication: type %d",
4978 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4979 * we can look at the string in it and know what we can
4980 * helpfully try next.
4982 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
4985 ssh_pkt_getstring(ssh, &methods, &methlen);
4986 s->kbd_inter_running = FALSE;
4987 if (!ssh2_pkt_getbool(ssh)) {
4989 * We have received an unequivocal Access
4990 * Denied. This can translate to a variety of
4993 * - if we'd just tried "none" authentication,
4994 * it's not worth printing anything at all
4996 * - if we'd just tried a public key _offer_,
4997 * the message should be "Server refused our
4998 * key" (or no message at all if the key
4999 * came from Pageant)
5001 * - if we'd just tried anything else, the
5002 * message really should be "Access denied".
5004 * Additionally, if we'd just tried password
5005 * authentication, we should break out of this
5006 * whole loop so as to go back to the username
5009 if (s->type == AUTH_TYPE_NONE) {
5011 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
5012 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
5013 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
5014 c_write_str(ssh, "Server refused our key\r\n");
5015 logevent("Server refused public key");
5016 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
5017 /* server declined keyboard-interactive; ignore */
5019 c_write_str(ssh, "Access denied\r\n");
5020 logevent("Access denied");
5021 if (s->type == AUTH_TYPE_PASSWORD) {
5022 s->we_are_in = FALSE;
5027 c_write_str(ssh, "Further authentication required\r\n");
5028 logevent("Further authentication required");
5032 in_commasep_string("publickey", methods, methlen);
5034 in_commasep_string("password", methods, methlen);
5035 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
5036 in_commasep_string("keyboard-interactive", methods, methlen);
5040 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5044 * Most password/passphrase prompts will be
5045 * non-echoing, so we set this to 0 by default.
5046 * Exception is that some keyboard-interactive prompts
5047 * can be echoing, in which case we'll set this to 1.
5051 if (!s->method && s->can_pubkey &&
5052 agent_exists() && !s->tried_agent) {
5054 * Attempt public-key authentication using Pageant.
5059 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5060 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
5062 s->tried_agent = TRUE;
5064 logevent("Pageant is running. Requesting keys.");
5066 /* Request the keys held by the agent. */
5067 PUT_32BIT(s->request, 1);
5068 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
5069 if (!agent_query(s->request, 5, &r, &s->responselen,
5070 ssh_agent_callback, ssh)) {
5074 bombout(("Unexpected data from server while"
5075 " waiting for agent response"));
5078 } while (ispkt || inlen > 0);
5079 r = ssh->agent_response;
5080 s->responselen = ssh->agent_response_len;
5082 s->response = (unsigned char *) r;
5083 if (s->response && s->responselen >= 5 &&
5084 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
5085 s->p = s->response + 5;
5086 s->nkeys = GET_32BIT(s->p);
5090 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
5093 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
5098 sprintf(buf, "Trying Pageant key #%d", s->keyi);
5101 s->pklen = GET_32BIT(s->p);
5103 if (s->publickey_blob &&
5104 s->pklen == s->publickey_bloblen &&
5105 !memcmp(s->p, s->publickey_blob,
5106 s->publickey_bloblen)) {
5107 logevent("This key matches configured key file");
5108 s->tried_pubkey_config = 1;
5110 s->pkblob = (char *)s->p;
5112 s->alglen = GET_32BIT(s->pkblob);
5113 s->alg = s->pkblob + 4;
5114 s->commentlen = GET_32BIT(s->p);
5116 s->commentp = (char *)s->p;
5117 s->p += s->commentlen;
5118 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5119 ssh2_pkt_addstring(ssh, s->username);
5120 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5121 ssh2_pkt_addstring(ssh, "publickey"); /* method */
5122 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
5123 ssh2_pkt_addstring_start(ssh);
5124 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
5125 ssh2_pkt_addstring_start(ssh);
5126 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
5129 crWaitUntilV(ispkt);
5130 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
5131 logevent("Key refused");
5135 if (flags & FLAG_VERBOSE) {
5136 c_write_str(ssh, "Authenticating with "
5138 c_write(ssh, s->commentp, s->commentlen);
5139 c_write_str(ssh, "\" from agent\r\n");
5143 * Server is willing to accept the key.
5144 * Construct a SIGN_REQUEST.
5146 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5147 ssh2_pkt_addstring(ssh, s->username);
5148 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5149 ssh2_pkt_addstring(ssh, "publickey"); /* method */
5150 ssh2_pkt_addbool(ssh, TRUE);
5151 ssh2_pkt_addstring_start(ssh);
5152 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
5153 ssh2_pkt_addstring_start(ssh);
5154 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
5156 s->siglen = ssh->pktout.length - 5 + 4 + 20;
5157 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
5159 s->len = 1; /* message type */
5160 s->len += 4 + s->pklen; /* key blob */
5161 s->len += 4 + s->siglen; /* data to sign */
5162 s->len += 4; /* flags */
5163 s->agentreq = snewn(4 + s->len, char);
5164 PUT_32BIT(s->agentreq, s->len);
5165 s->q = s->agentreq + 4;
5166 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
5167 PUT_32BIT(s->q, s->pklen);
5169 memcpy(s->q, s->pkblob, s->pklen);
5171 PUT_32BIT(s->q, s->siglen);
5173 /* Now the data to be signed... */
5174 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
5175 PUT_32BIT(s->q, 20);
5178 memcpy(s->q, ssh->v2_session_id, 20);
5180 memcpy(s->q, ssh->pktout.data + 5,
5181 ssh->pktout.length - 5);
5182 s->q += ssh->pktout.length - 5;
5183 /* And finally the (zero) flags word. */
5185 if (!agent_query(s->agentreq, s->len + 4,
5187 ssh_agent_callback, ssh)) {
5191 bombout(("Unexpected data from server"
5192 " while waiting for agent"
5196 } while (ispkt || inlen > 0);
5197 vret = ssh->agent_response;
5198 s->retlen = ssh->agent_response_len;
5203 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
5204 logevent("Sending Pageant's response");
5205 ssh2_add_sigblob(ssh, s->pkblob, s->pklen,
5207 GET_32BIT(s->ret + 5));
5213 ("Pageant failed to answer challenge");
5224 if (!s->method && s->can_pubkey && s->publickey_blob
5225 && !s->tried_pubkey_config) {
5226 unsigned char *pub_blob;
5227 char *algorithm, *comment;
5230 s->tried_pubkey_config = TRUE;
5232 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5233 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
5236 * Try the public key supplied in the configuration.
5238 * First, offer the public blob to see if the server is
5239 * willing to accept it.
5242 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
5247 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5248 ssh2_pkt_addstring(ssh, s->username);
5249 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5250 ssh2_pkt_addstring(ssh, "publickey"); /* method */
5251 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
5252 ssh2_pkt_addstring(ssh, algorithm);
5253 ssh2_pkt_addstring_start(ssh);
5254 ssh2_pkt_addstring_data(ssh, (char *)pub_blob,
5257 logevent("Offered public key"); /* FIXME */
5259 crWaitUntilV(ispkt);
5260 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
5262 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
5263 continue; /* key refused; give up on it */
5266 logevent("Offer of public key accepted");
5268 * Actually attempt a serious authentication using
5271 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
5272 sprintf(s->pwprompt,
5273 "Passphrase for key \"%.100s\": ",
5279 if (flags & FLAG_VERBOSE) {
5280 c_write_str(ssh, "Authenticating with public key \"");
5281 c_write_str(ssh, comment);
5282 c_write_str(ssh, "\"\r\n");
5284 s->method = AUTH_PUBLICKEY_FILE;
5288 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
5289 s->method = AUTH_KEYBOARD_INTERACTIVE;
5290 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5291 s->tried_keyb_inter = TRUE;
5293 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5294 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
5296 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5297 ssh2_pkt_addstring(ssh, s->username);
5298 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5299 ssh2_pkt_addstring(ssh, "keyboard-interactive"); /* method */
5300 ssh2_pkt_addstring(ssh, ""); /* lang */
5301 ssh2_pkt_addstring(ssh, "");
5304 crWaitUntilV(ispkt);
5305 if (ssh->pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
5306 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE)
5308 logevent("Keyboard-interactive authentication refused");
5309 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
5313 s->kbd_inter_running = TRUE;
5317 if (s->kbd_inter_running) {
5318 s->method = AUTH_KEYBOARD_INTERACTIVE;
5319 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5320 s->tried_keyb_inter = TRUE;
5322 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5323 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
5325 if (s->curr_prompt == 0) {
5327 * We've got a fresh USERAUTH_INFO_REQUEST.
5328 * Display header data, and start going through
5331 char *name, *inst, *lang;
5332 int name_len, inst_len, lang_len;
5334 ssh_pkt_getstring(ssh, &name, &name_len);
5335 ssh_pkt_getstring(ssh, &inst, &inst_len);
5336 ssh_pkt_getstring(ssh, &lang, &lang_len);
5338 c_write_untrusted(ssh, name, name_len);
5339 c_write_str(ssh, "\r\n");
5342 c_write_untrusted(ssh, inst, inst_len);
5343 c_write_str(ssh, "\r\n");
5345 s->num_prompts = ssh_pkt_getuint32(ssh);
5349 * If there are prompts remaining in the packet,
5350 * display one and get a response.
5352 if (s->curr_prompt < s->num_prompts) {
5356 ssh_pkt_getstring(ssh, &prompt, &prompt_len);
5357 if (prompt_len > 0) {
5358 static const char trunc[] = "<prompt truncated>: ";
5359 static const int prlen = sizeof(s->pwprompt) -
5361 if (prompt_len > prlen) {
5362 memcpy(s->pwprompt, prompt, prlen);
5363 strcpy(s->pwprompt + prlen, trunc);
5365 memcpy(s->pwprompt, prompt, prompt_len);
5366 s->pwprompt[prompt_len] = '\0';
5370 "<server failed to send prompt>: ");
5372 s->echo = ssh2_pkt_getbool(ssh);
5378 if (!s->method && s->can_passwd) {
5379 s->method = AUTH_PASSWORD;
5380 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5381 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
5382 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
5389 if (!ssh_get_line(s->pwprompt, s->password,
5390 sizeof(s->password), TRUE)) {
5392 * get_line failed to get a password (for
5393 * example because one was supplied on the
5394 * command line which has already failed to
5397 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5398 ssh2_pkt_adduint32(ssh,SSH2_DISCONNECT_BY_APPLICATION);
5399 ssh2_pkt_addstring(ssh, "No more passwords available"
5401 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5403 logevent("Unable to authenticate");
5404 connection_fatal(ssh->frontend,
5405 "Unable to authenticate");
5406 ssh_closing((Plug)ssh, NULL, 0, 0);
5410 int ret; /* need not be saved across crReturn */
5411 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
5414 setup_userpass_input(ssh, s->password,
5415 sizeof(s->password), s->echo);
5417 crWaitUntilV(!ispkt);
5418 ret = process_userpass_input(ssh, in, inlen);
5422 c_write_str(ssh, "\r\n");
5426 if (s->method == AUTH_PUBLICKEY_FILE) {
5428 * We have our passphrase. Now try the actual authentication.
5430 struct ssh2_userkey *key;
5431 const char *error = NULL;
5433 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
5435 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
5436 if (key == SSH2_WRONG_PASSPHRASE) {
5437 c_write_str(ssh, "Wrong passphrase\r\n");
5438 s->tried_pubkey_config = FALSE;
5440 c_write_str(ssh, "Unable to load private key (");
5441 c_write_str(ssh, error);
5442 c_write_str(ssh, ")\r\n");
5443 s->tried_pubkey_config = TRUE;
5445 /* Send a spurious AUTH_NONE to return to the top. */
5446 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5447 ssh2_pkt_addstring(ssh, s->username);
5448 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5449 ssh2_pkt_addstring(ssh, "none"); /* method */
5451 s->type = AUTH_TYPE_NONE;
5453 unsigned char *pkblob, *sigblob, *sigdata;
5454 int pkblob_len, sigblob_len, sigdata_len;
5458 * We have loaded the private key and the server
5459 * has announced that it's willing to accept it.
5460 * Hallelujah. Generate a signature and send it.
5462 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5463 ssh2_pkt_addstring(ssh, s->username);
5464 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5465 ssh2_pkt_addstring(ssh, "publickey"); /* method */
5466 ssh2_pkt_addbool(ssh, TRUE);
5467 ssh2_pkt_addstring(ssh, key->alg->name);
5468 pkblob = key->alg->public_blob(key->data, &pkblob_len);
5469 ssh2_pkt_addstring_start(ssh);
5470 ssh2_pkt_addstring_data(ssh, (char *)pkblob, pkblob_len);
5473 * The data to be signed is:
5477 * followed by everything so far placed in the
5480 sigdata_len = ssh->pktout.length - 5 + 4 + 20;
5481 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
5483 sigdata = snewn(sigdata_len, unsigned char);
5485 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
5486 PUT_32BIT(sigdata+p, 20);
5489 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
5490 memcpy(sigdata+p, ssh->pktout.data + 5,
5491 ssh->pktout.length - 5);
5492 p += ssh->pktout.length - 5;
5493 assert(p == sigdata_len);
5494 sigblob = key->alg->sign(key->data, (char *)sigdata,
5495 sigdata_len, &sigblob_len);
5496 ssh2_add_sigblob(ssh, pkblob, pkblob_len,
5497 sigblob, sigblob_len);
5503 s->type = AUTH_TYPE_PUBLICKEY;
5504 key->alg->freekey(key->data);
5506 } else if (s->method == AUTH_PASSWORD) {
5508 * We send the password packet lumped tightly together with
5509 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
5510 * string long enough to make the total length of the two
5511 * packets constant. This should ensure that a passive
5512 * listener doing traffic analyis can't work out the length
5515 * For this to work, we need an assumption about the
5516 * maximum length of the password packet. I think 256 is
5517 * pretty conservative. Anyone using a password longer than
5518 * that probably doesn't have much to worry about from
5519 * people who find out how long their password is!
5521 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5522 ssh2_pkt_addstring(ssh, s->username);
5523 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5524 ssh2_pkt_addstring(ssh, "password");
5525 ssh2_pkt_addbool(ssh, FALSE);
5526 dont_log_password(ssh, PKTLOG_BLANK);
5527 ssh2_pkt_addstring(ssh, s->password);
5528 memset(s->password, 0, sizeof(s->password));
5529 end_log_omission(ssh);
5530 ssh2_pkt_defer(ssh);
5532 * We'll include a string that's an exact multiple of the
5533 * cipher block size. If the cipher is NULL for some
5534 * reason, we don't do this trick at all because we gain
5537 if (ssh->cscipher) {
5540 stringlen = (256 - ssh->deferred_len);
5541 stringlen += ssh->cscipher->blksize - 1;
5542 stringlen -= (stringlen % ssh->cscipher->blksize);
5545 * Temporarily disable actual compression,
5546 * so we can guarantee to get this string
5547 * exactly the length we want it. The
5548 * compression-disabling routine should
5549 * return an integer indicating how many
5550 * bytes we should adjust our string length
5554 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
5556 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
5557 ssh2_pkt_addstring_start(ssh);
5558 for (i = 0; i < stringlen; i++) {
5559 char c = (char) random_byte();
5560 ssh2_pkt_addstring_data(ssh, &c, 1);
5562 ssh2_pkt_defer(ssh);
5564 ssh_pkt_defersend(ssh);
5565 logevent("Sent password");
5566 s->type = AUTH_TYPE_PASSWORD;
5567 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
5568 if (s->curr_prompt == 0) {
5569 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE);
5570 ssh2_pkt_adduint32(ssh, s->num_prompts);
5572 if (s->need_pw) { /* only add pw if we just got one! */
5573 dont_log_password(ssh, PKTLOG_BLANK);
5574 ssh2_pkt_addstring(ssh, s->password);
5575 memset(s->password, 0, sizeof(s->password));
5576 end_log_omission(ssh);
5579 if (s->curr_prompt >= s->num_prompts) {
5583 * If there are prompts remaining, we set
5584 * `gotit' so that we won't attempt to get
5585 * another packet. Then we go back round the
5586 * loop and will end up retrieving another
5587 * prompt out of the existing packet. Funky or
5592 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5594 c_write_str(ssh, "No supported authentication methods"
5595 " left to try!\r\n");
5596 logevent("No supported authentications offered."
5598 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5599 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5600 ssh2_pkt_addstring(ssh, "No supported authentication"
5601 " methods available");
5602 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5604 ssh_closing((Plug)ssh, NULL, 0, 0);
5608 } while (!s->we_are_in);
5611 * Now we're authenticated for the connection protocol. The
5612 * connection protocol will automatically have started at this
5613 * point; there's no need to send SERVICE_REQUEST.
5616 ssh->channels = newtree234(ssh_channelcmp);
5619 * Create the main session channel.
5621 if (!ssh->cfg.ssh_no_shell) {
5622 ssh->mainchan = snew(struct ssh_channel);
5623 ssh->mainchan->ssh = ssh;
5624 ssh->mainchan->localid = alloc_channel_id(ssh);
5625 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
5626 ssh2_pkt_addstring(ssh, "session");
5627 ssh2_pkt_adduint32(ssh, ssh->mainchan->localid);
5628 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
5629 ssh2_pkt_adduint32(ssh, ssh->mainchan->v.v2.locwindow);/* our window size */
5630 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5632 crWaitUntilV(ispkt);
5633 if (ssh->pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5634 bombout(("Server refused to open a session"));
5636 /* FIXME: error data comes back in FAILURE packet */
5638 if (ssh_pkt_getuint32(ssh) != ssh->mainchan->localid) {
5639 bombout(("Server's channel confirmation cited wrong channel"));
5642 ssh->mainchan->remoteid = ssh_pkt_getuint32(ssh);
5643 ssh->mainchan->type = CHAN_MAINSESSION;
5644 ssh->mainchan->closes = 0;
5645 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(ssh);
5646 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(ssh);
5647 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
5648 add234(ssh->channels, ssh->mainchan);
5649 update_specials_menu(ssh->frontend);
5650 logevent("Opened channel for session");
5652 ssh->mainchan = NULL;
5655 * Potentially enable X11 forwarding.
5657 if (ssh->mainchan && ssh->cfg.x11_forward) {
5658 char proto[20], data[64];
5659 logevent("Requesting X11 forwarding");
5660 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
5661 data, sizeof(data), ssh->cfg.x11_auth);
5662 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
5663 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5664 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5665 ssh2_pkt_addstring(ssh, "x11-req");
5666 ssh2_pkt_addbool(ssh, 1); /* want reply */
5667 ssh2_pkt_addbool(ssh, 0); /* many connections */
5668 ssh2_pkt_addstring(ssh, proto);
5669 ssh2_pkt_addstring(ssh, data);
5670 ssh2_pkt_adduint32(ssh, x11_get_screen_number(ssh->cfg.x11_display));
5674 crWaitUntilV(ispkt);
5675 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5676 unsigned i = ssh_pkt_getuint32(ssh);
5677 struct ssh_channel *c;
5678 c = find234(ssh->channels, &i, ssh_channelfind);
5680 continue; /* nonexistent channel */
5681 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
5683 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5685 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5686 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5687 bombout(("Unexpected response to X11 forwarding request:"
5688 " packet type %d", ssh->pktin.type));
5691 logevent("X11 forwarding refused");
5693 logevent("X11 forwarding enabled");
5694 ssh->X11_fwd_enabled = TRUE;
5699 * Enable port forwardings.
5704 int sport,dport,sserv,dserv;
5705 char sports[256], dports[256], saddr[256], host[256];
5707 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5708 /* Add port forwardings. */
5709 ssh->portfwd_strptr = ssh->cfg.portfwd;
5710 while (*ssh->portfwd_strptr) {
5711 type = *ssh->portfwd_strptr++;
5714 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
5715 if (*ssh->portfwd_strptr == ':') {
5717 * We've seen a colon in the middle of the
5718 * source port number. This means that
5719 * everything we've seen until now is the
5720 * source _address_, so we'll move it into
5721 * saddr and start sports from the beginning
5724 ssh->portfwd_strptr++;
5726 strcpy(saddr, sports);
5729 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
5733 if (*ssh->portfwd_strptr == '\t')
5734 ssh->portfwd_strptr++;
5736 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
5737 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
5740 if (*ssh->portfwd_strptr == ':')
5741 ssh->portfwd_strptr++;
5743 while (*ssh->portfwd_strptr) {
5744 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
5747 ssh->portfwd_strptr++;
5748 dport = atoi(dports);
5752 dport = net_service_lookup(dports);
5754 logeventf(ssh, "Service lookup failed for destination"
5755 " port \"%s\"", dports);
5759 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
5761 ssh->portfwd_strptr++; /* eat the NUL and move to next one */
5763 sport = atoi(sports);
5767 sport = net_service_lookup(sports);
5769 logeventf(ssh, "Service lookup failed for source"
5770 " port \"%s\"", sports);
5773 if (sport && dport) {
5774 /* Set up a description of the source port. */
5775 char *sportdesc = dupprintf("%.*s%.*s%.*s%.*s%d%.*s",
5776 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5777 (int)(*saddr?1:0), ":",
5778 (int)(sserv ? strlen(sports) : 0), sports,
5779 sserv, "(", sport, sserv, ")");
5781 /* Verbose description of the destination port */
5782 char *dportdesc = dupprintf("%s:%.*s%.*s%d%.*s",
5784 (int)(dserv ? strlen(dports) : 0), dports,
5785 dserv, "(", dport, dserv, ")");
5786 const char *err = pfd_addforward(host, dport,
5787 *saddr ? saddr : NULL,
5788 sport, ssh, &ssh->cfg);
5790 logeventf(ssh, "Local port %s forward to %s"
5791 " failed: %s", sportdesc, dportdesc, err);
5793 logeventf(ssh, "Local port %s forwarding to %s",
5794 sportdesc, dportdesc);
5797 } else if (type == 'D') {
5798 const char *err = pfd_addforward(NULL, -1,
5799 *saddr ? saddr : NULL,
5800 sport, ssh, &ssh->cfg);
5802 logeventf(ssh, "Local port %s SOCKS dynamic forward"
5803 " setup failed: %s", sportdesc, err);
5805 logeventf(ssh, "Local port %s doing SOCKS"
5806 " dynamic forwarding", sportdesc);
5809 struct ssh_rportfwd *pf;
5810 pf = snew(struct ssh_rportfwd);
5811 strcpy(pf->dhost, host);
5814 if (add234(ssh->rportfwds, pf) != pf) {
5815 logeventf(ssh, "Duplicate remote port forwarding"
5816 " to %s:%d", host, dport);
5819 logeventf(ssh, "Requesting remote port %s"
5820 " forward to %s:%.*s%.*s%d%.*s",
5823 (int)(dserv ? strlen(dports) : 0), dports,
5824 dserv, "(", dport, dserv, ")");
5825 ssh2_pkt_init(ssh, SSH2_MSG_GLOBAL_REQUEST);
5826 ssh2_pkt_addstring(ssh, "tcpip-forward");
5827 ssh2_pkt_addbool(ssh, 1);/* want reply */
5829 ssh2_pkt_addstring(ssh, saddr);
5830 if (ssh->cfg.rport_acceptall)
5831 ssh2_pkt_addstring(ssh, "0.0.0.0");
5833 ssh2_pkt_addstring(ssh, "127.0.0.1");
5834 ssh2_pkt_adduint32(ssh, sport);
5838 crWaitUntilV(ispkt);
5839 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5840 unsigned i = ssh_pkt_getuint32(ssh);
5841 struct ssh_channel *c;
5842 c = find234(ssh->channels, &i, ssh_channelfind);
5844 continue;/* nonexistent channel */
5845 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
5847 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5849 if (ssh->pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5850 if (ssh->pktin.type != SSH2_MSG_REQUEST_FAILURE) {
5851 bombout(("Unexpected response to port "
5852 "forwarding request: packet type %d",
5856 logevent("Server refused this port forwarding");
5858 logevent("Remote port forwarding enabled");
5868 * Potentially enable agent forwarding.
5870 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
5871 logevent("Requesting OpenSSH-style agent forwarding");
5872 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5873 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5874 ssh2_pkt_addstring(ssh, "auth-agent-req@openssh.com");
5875 ssh2_pkt_addbool(ssh, 1); /* want reply */
5879 crWaitUntilV(ispkt);
5880 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5881 unsigned i = ssh_pkt_getuint32(ssh);
5882 struct ssh_channel *c;
5883 c = find234(ssh->channels, &i, ssh_channelfind);
5885 continue; /* nonexistent channel */
5886 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
5888 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5890 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5891 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5892 bombout(("Unexpected response to agent forwarding request:"
5893 " packet type %d", ssh->pktin.type));
5896 logevent("Agent forwarding refused");
5898 logevent("Agent forwarding enabled");
5899 ssh->agentfwd_enabled = TRUE;
5904 * Now allocate a pty for the session.
5906 if (ssh->mainchan && !ssh->cfg.nopty) {
5907 /* Unpick the terminal-speed string. */
5908 /* XXX perhaps we should allow no speeds to be sent. */
5909 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5910 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
5911 /* Build the pty request. */
5912 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5913 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5914 ssh2_pkt_addstring(ssh, "pty-req");
5915 ssh2_pkt_addbool(ssh, 1); /* want reply */
5916 ssh2_pkt_addstring(ssh, ssh->cfg.termtype);
5917 ssh2_pkt_adduint32(ssh, ssh->term_width);
5918 ssh2_pkt_adduint32(ssh, ssh->term_height);
5919 ssh2_pkt_adduint32(ssh, 0); /* pixel width */
5920 ssh2_pkt_adduint32(ssh, 0); /* pixel height */
5921 ssh2_pkt_addstring_start(ssh);
5922 ssh2_pkt_addbyte(ssh, 128); /* TTY_OP_ISPEED */
5923 ssh2_pkt_adduint32(ssh, ssh->ispeed);
5924 ssh2_pkt_addbyte(ssh, 129); /* TTY_OP_OSPEED */
5925 ssh2_pkt_adduint32(ssh, ssh->ospeed);
5926 ssh2_pkt_addstring_data(ssh, "\0", 1); /* TTY_OP_END */
5928 ssh->state = SSH_STATE_INTERMED;
5931 crWaitUntilV(ispkt);
5932 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5933 unsigned i = ssh_pkt_getuint32(ssh);
5934 struct ssh_channel *c;
5935 c = find234(ssh->channels, &i, ssh_channelfind);
5937 continue; /* nonexistent channel */
5938 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
5940 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5942 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5943 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5944 bombout(("Unexpected response to pty request:"
5945 " packet type %d", ssh->pktin.type));
5948 c_write_str(ssh, "Server refused to allocate pty\r\n");
5949 ssh->editing = ssh->echoing = 1;
5951 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5952 ssh->ospeed, ssh->ispeed);
5955 ssh->editing = ssh->echoing = 1;
5959 * Send environment variables.
5961 * Simplest thing here is to send all the requests at once, and
5962 * then wait for a whole bunch of successes or failures.
5964 if (ssh->mainchan && *ssh->cfg.environmt) {
5965 char *e = ssh->cfg.environmt;
5966 char *var, *varend, *val;
5972 while (*e && *e != '\t') e++;
5974 if (*e == '\t') e++;
5979 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5980 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5981 ssh2_pkt_addstring(ssh, "env");
5982 ssh2_pkt_addbool(ssh, 1); /* want reply */
5983 ssh2_pkt_addstring_start(ssh);
5984 ssh2_pkt_addstring_data(ssh, var, varend-var);
5985 ssh2_pkt_addstring(ssh, val);
5991 logeventf(ssh, "Sent %d environment variables", s->num_env);
5994 s->env_left = s->num_env;
5996 while (s->env_left > 0) {
5998 crWaitUntilV(ispkt);
5999 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
6000 unsigned i = ssh_pkt_getuint32(ssh);
6001 struct ssh_channel *c;
6002 c = find234(ssh->channels, &i, ssh_channelfind);
6004 continue; /* nonexistent channel */
6005 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
6007 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
6009 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
6010 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
6011 bombout(("Unexpected response to environment request:"
6012 " packet type %d", ssh->pktin.type));
6022 if (s->env_ok == s->num_env) {
6023 logevent("All environment variables successfully set");
6024 } else if (s->env_ok == 0) {
6025 logevent("All environment variables refused");
6026 c_write_str(ssh, "Server refused to set environment variables\r\n");
6028 logeventf(ssh, "%d environment variables refused",
6029 s->num_env - s->env_ok);
6030 c_write_str(ssh, "Server refused to set all environment variables\r\n");
6035 * Start a shell or a remote command. We may have to attempt
6036 * this twice if the config data has provided a second choice
6039 if (ssh->mainchan) while (1) {
6043 if (ssh->fallback_cmd) {
6044 subsys = ssh->cfg.ssh_subsys2;
6045 cmd = ssh->cfg.remote_cmd_ptr2;
6047 subsys = ssh->cfg.ssh_subsys;
6048 cmd = ssh->cfg.remote_cmd_ptr;
6051 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6052 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
6054 ssh2_pkt_addstring(ssh, "subsystem");
6055 ssh2_pkt_addbool(ssh, 1); /* want reply */
6056 ssh2_pkt_addstring(ssh, cmd);
6058 ssh2_pkt_addstring(ssh, "exec");
6059 ssh2_pkt_addbool(ssh, 1); /* want reply */
6060 ssh2_pkt_addstring(ssh, cmd);
6062 ssh2_pkt_addstring(ssh, "shell");
6063 ssh2_pkt_addbool(ssh, 1); /* want reply */
6067 crWaitUntilV(ispkt);
6068 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
6069 unsigned i = ssh_pkt_getuint32(ssh);
6070 struct ssh_channel *c;
6071 c = find234(ssh->channels, &i, ssh_channelfind);
6073 continue; /* nonexistent channel */
6074 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
6076 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
6077 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
6078 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
6079 bombout(("Unexpected response to shell/command request:"
6080 " packet type %d", ssh->pktin.type));
6084 * We failed to start the command. If this is the
6085 * fallback command, we really are finished; if it's
6086 * not, and if the fallback command exists, try falling
6087 * back to it before complaining.
6089 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
6090 logevent("Primary command failed; attempting fallback");
6091 ssh->fallback_cmd = TRUE;
6094 bombout(("Server refused to start a shell/command"));
6097 logevent("Started a shell/command");
6102 ssh->state = SSH_STATE_SESSION;
6103 if (ssh->size_needed)
6104 ssh_size(ssh, ssh->term_width, ssh->term_height);
6105 if (ssh->eof_needed)
6106 ssh_special(ssh, TS_EOF);
6112 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
6117 s->try_send = FALSE;
6119 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA ||
6120 ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
6123 unsigned i = ssh_pkt_getuint32(ssh);
6124 struct ssh_channel *c;
6125 c = find234(ssh->channels, &i, ssh_channelfind);
6127 continue; /* nonexistent channel */
6128 if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
6129 ssh_pkt_getuint32(ssh) != SSH2_EXTENDED_DATA_STDERR)
6130 continue; /* extended but not stderr */
6131 ssh_pkt_getstring(ssh, &data, &length);
6134 c->v.v2.locwindow -= length;
6136 case CHAN_MAINSESSION:
6138 from_backend(ssh->frontend, ssh->pktin.type ==
6139 SSH2_MSG_CHANNEL_EXTENDED_DATA,
6143 bufsize = x11_send(c->u.x11.s, data, length);
6146 bufsize = pfd_send(c->u.pfd.s, data, length);
6149 while (length > 0) {
6150 if (c->u.a.lensofar < 4) {
6151 int l = min(4 - c->u.a.lensofar, length);
6152 memcpy(c->u.a.msglen + c->u.a.lensofar,
6156 c->u.a.lensofar += l;
6158 if (c->u.a.lensofar == 4) {
6160 4 + GET_32BIT(c->u.a.msglen);
6161 c->u.a.message = snewn(c->u.a.totallen,
6163 memcpy(c->u.a.message, c->u.a.msglen, 4);
6165 if (c->u.a.lensofar >= 4 && length > 0) {
6167 min(c->u.a.totallen - c->u.a.lensofar,
6169 memcpy(c->u.a.message + c->u.a.lensofar,
6173 c->u.a.lensofar += l;
6175 if (c->u.a.lensofar == c->u.a.totallen) {
6178 if (agent_query(c->u.a.message,
6181 ssh_agentf_callback, c))
6182 ssh_agentf_callback(c, reply, replylen);
6183 sfree(c->u.a.message);
6184 c->u.a.lensofar = 0;
6191 * If we are not buffering too much data,
6192 * enlarge the window again at the remote side.
6194 if (bufsize < OUR_V2_WINSIZE)
6195 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
6197 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EOF) {
6198 unsigned i = ssh_pkt_getuint32(ssh);
6199 struct ssh_channel *c;
6201 c = find234(ssh->channels, &i, ssh_channelfind);
6203 continue; /* nonexistent channel */
6205 if (c->type == CHAN_X11) {
6207 * Remote EOF on an X11 channel means we should
6208 * wrap up and close the channel ourselves.
6210 x11_close(c->u.x11.s);
6212 } else if (c->type == CHAN_AGENT) {
6214 } else if (c->type == CHAN_SOCKDATA) {
6215 pfd_close(c->u.pfd.s);
6218 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
6219 unsigned i = ssh_pkt_getuint32(ssh);
6220 struct ssh_channel *c;
6222 c = find234(ssh->channels, &i, ssh_channelfind);
6223 if (!c || ((int)c->remoteid) == -1) {
6224 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
6225 c ? "half-open" : "nonexistent", i));
6228 /* Do pre-close processing on the channel. */
6230 case CHAN_MAINSESSION:
6231 ssh->mainchan = NULL;
6232 update_specials_menu(ssh->frontend);
6235 if (c->u.x11.s != NULL)
6236 x11_close(c->u.x11.s);
6243 if (c->u.pfd.s != NULL)
6244 pfd_close(c->u.pfd.s);
6248 if (c->closes == 0) {
6249 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
6250 ssh2_pkt_adduint32(ssh, c->remoteid);
6253 del234(ssh->channels, c);
6254 bufchain_clear(&c->v.v2.outbuffer);
6258 * See if that was the last channel left open.
6259 * (This is only our termination condition if we're
6260 * not running in -N mode.)
6262 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
6263 logevent("All channels closed. Disconnecting");
6266 * We used to send SSH_MSG_DISCONNECT here,
6267 * because I'd believed that _every_ conforming
6268 * SSH2 connection had to end with a disconnect
6269 * being sent by at least one side; apparently
6270 * I was wrong and it's perfectly OK to
6271 * unceremoniously slam the connection shut
6272 * when you're done, and indeed OpenSSH feels
6273 * this is more polite than sending a
6274 * DISCONNECT. So now we don't.
6276 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
6277 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
6278 ssh2_pkt_addstring(ssh, "All open channels closed");
6279 ssh2_pkt_addstring(ssh, "en"); /* language tag */
6282 ssh_closing((Plug)ssh, NULL, 0, 0);
6285 continue; /* remote sends close; ignore (FIXME) */
6286 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
6287 unsigned i = ssh_pkt_getuint32(ssh);
6288 struct ssh_channel *c;
6289 c = find234(ssh->channels, &i, ssh_channelfind);
6290 if (!c || c->closes)
6291 continue; /* nonexistent or closing channel */
6292 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
6294 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
6295 unsigned i = ssh_pkt_getuint32(ssh);
6296 struct ssh_channel *c;
6297 c = find234(ssh->channels, &i, ssh_channelfind);
6299 continue; /* nonexistent channel */
6300 if (c->type != CHAN_SOCKDATA_DORMANT)
6301 continue; /* dunno why they're confirming this */
6302 c->remoteid = ssh_pkt_getuint32(ssh);
6303 c->type = CHAN_SOCKDATA;
6304 c->v.v2.remwindow = ssh_pkt_getuint32(ssh);
6305 c->v.v2.remmaxpkt = ssh_pkt_getuint32(ssh);
6307 pfd_confirm(c->u.pfd.s);
6310 * We have a pending close on this channel,
6311 * which we decided on before the server acked
6312 * the channel open. So now we know the
6313 * remoteid, we can close it again.
6315 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
6316 ssh2_pkt_adduint32(ssh, c->remoteid);
6319 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
6320 static const char *const reasons[] = {
6321 "<unknown reason code>",
6322 "Administratively prohibited",
6324 "Unknown channel type",
6325 "Resource shortage",
6327 unsigned i = ssh_pkt_getuint32(ssh);
6328 unsigned reason_code;
6329 char *reason_string;
6332 struct ssh_channel *c;
6333 c = find234(ssh->channels, &i, ssh_channelfind);
6335 continue; /* nonexistent channel */
6336 if (c->type != CHAN_SOCKDATA_DORMANT)
6337 continue; /* dunno why they're failing this */
6339 reason_code = ssh_pkt_getuint32(ssh);
6340 if (reason_code >= lenof(reasons))
6341 reason_code = 0; /* ensure reasons[reason_code] in range */
6342 ssh_pkt_getstring(ssh, &reason_string, &reason_length);
6343 message = dupprintf("Forwarded connection refused by"
6344 " server: %s [%.*s]", reasons[reason_code],
6345 reason_length, reason_string);
6349 pfd_close(c->u.pfd.s);
6351 del234(ssh->channels, c);
6353 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
6356 int typelen, want_reply;
6357 struct ssh_channel *c;
6359 localid = ssh_pkt_getuint32(ssh);
6360 ssh_pkt_getstring(ssh, &type, &typelen);
6361 want_reply = ssh2_pkt_getbool(ssh);
6364 * First, check that the channel exists. Otherwise,
6365 * we can instantly disconnect with a rude message.
6367 c = find234(ssh->channels, &localid, ssh_channelfind);
6370 sprintf(buf, "Received channel request for nonexistent"
6371 " channel %d", localid);
6373 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
6374 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
6375 ssh2_pkt_addstring(ssh, buf);
6376 ssh2_pkt_addstring(ssh, "en"); /* language tag */
6378 connection_fatal(ssh->frontend, "%s", buf);
6379 ssh_closing((Plug)ssh, NULL, 0, 0);
6384 * Having got the channel number, we now look at
6385 * the request type string to see if it's something
6388 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
6389 c == ssh->mainchan) {
6390 /* We recognise "exit-status" on the primary channel. */
6392 ssh->exitcode = ssh_pkt_getuint32(ssh);
6393 sprintf(buf, "Server sent command exit status %d",
6397 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_SUCCESS);
6398 ssh2_pkt_adduint32(ssh, c->remoteid);
6403 * This is a channel request we don't know
6404 * about, so we now either ignore the request
6405 * or respond with CHANNEL_FAILURE, depending
6409 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_FAILURE);
6410 ssh2_pkt_adduint32(ssh, c->remoteid);
6414 } else if (ssh->pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
6416 int typelen, want_reply;
6418 ssh_pkt_getstring(ssh, &type, &typelen);
6419 want_reply = ssh2_pkt_getbool(ssh);
6422 * We currently don't support any global requests
6423 * at all, so we either ignore the request or
6424 * respond with REQUEST_FAILURE, depending on
6428 ssh2_pkt_init(ssh, SSH2_MSG_REQUEST_FAILURE);
6431 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN) {
6438 struct ssh_channel *c;
6439 unsigned remid, winsize, pktsize;
6440 ssh_pkt_getstring(ssh, &type, &typelen);
6441 c = snew(struct ssh_channel);
6444 remid = ssh_pkt_getuint32(ssh);
6445 winsize = ssh_pkt_getuint32(ssh);
6446 pktsize = ssh_pkt_getuint32(ssh);
6448 if (typelen == 3 && !memcmp(type, "x11", 3)) {
6451 ssh_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
6452 addrstr = snewn(peeraddrlen+1, char);
6453 memcpy(addrstr, peeraddr, peeraddrlen);
6454 addrstr[peeraddrlen] = '\0';
6455 peerport = ssh_pkt_getuint32(ssh);
6457 logeventf(ssh, "Received X11 connect request from %s:%d",
6460 if (!ssh->X11_fwd_enabled)
6461 error = "X11 forwarding is not enabled";
6462 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
6463 ssh->x11auth, addrstr, peerport,
6464 &ssh->cfg) != NULL) {
6465 error = "Unable to open an X11 connection";
6467 logevent("Opening X11 forward connection succeeded");
6472 } else if (typelen == 15 &&
6473 !memcmp(type, "forwarded-tcpip", 15)) {
6474 struct ssh_rportfwd pf, *realpf;
6477 ssh_pkt_getstring(ssh, &dummy, &dummylen);/* skip address */
6478 pf.sport = ssh_pkt_getuint32(ssh);
6479 ssh_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
6480 peerport = ssh_pkt_getuint32(ssh);
6481 realpf = find234(ssh->rportfwds, &pf, NULL);
6482 logeventf(ssh, "Received remote port %d open request "
6483 "from %s:%d", pf.sport, peeraddr, peerport);
6484 if (realpf == NULL) {
6485 error = "Remote port is not recognised";
6487 const char *e = pfd_newconnect(&c->u.pfd.s,
6491 logeventf(ssh, "Attempting to forward remote port to "
6492 "%s:%d", realpf->dhost, realpf->dport);
6494 logeventf(ssh, "Port open failed: %s", e);
6495 error = "Port open failed";
6497 logevent("Forwarded port opened successfully");
6498 c->type = CHAN_SOCKDATA;
6501 } else if (typelen == 22 &&
6502 !memcmp(type, "auth-agent@openssh.com", 3)) {
6503 if (!ssh->agentfwd_enabled)
6504 error = "Agent forwarding is not enabled";
6506 c->type = CHAN_AGENT; /* identify channel type */
6507 c->u.a.lensofar = 0;
6510 error = "Unsupported channel type requested";
6513 c->remoteid = remid;
6515 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE);
6516 ssh2_pkt_adduint32(ssh, c->remoteid);
6517 ssh2_pkt_adduint32(ssh, SSH2_OPEN_CONNECT_FAILED);
6518 ssh2_pkt_addstring(ssh, error);
6519 ssh2_pkt_addstring(ssh, "en"); /* language tag */
6521 logeventf(ssh, "Rejected channel open: %s", error);
6524 c->localid = alloc_channel_id(ssh);
6526 c->v.v2.locwindow = OUR_V2_WINSIZE;
6527 c->v.v2.remwindow = winsize;
6528 c->v.v2.remmaxpkt = pktsize;
6529 bufchain_init(&c->v.v2.outbuffer);
6530 add234(ssh->channels, c);
6531 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
6532 ssh2_pkt_adduint32(ssh, c->remoteid);
6533 ssh2_pkt_adduint32(ssh, c->localid);
6534 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);
6535 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6539 bombout(("Strange packet received: type %d", ssh->pktin.type));
6542 } else if (ssh->mainchan) {
6544 * We have spare data. Add it to the channel buffer.
6546 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
6551 struct ssh_channel *c;
6553 * Try to send data on all channels if we can.
6555 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
6558 continue; /* don't send on closing channels */
6559 bufsize = ssh2_try_send(c);
6562 case CHAN_MAINSESSION:
6563 /* stdin need not receive an unthrottle
6564 * notification since it will be polled */
6567 x11_unthrottle(c->u.x11.s);
6570 /* agent sockets are request/response and need no
6571 * buffer management */
6574 pfd_unthrottle(c->u.pfd.s);
6586 * Handle the top-level SSH2 protocol.
6588 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
6590 if (do_ssh2_transport(ssh, in, inlen, ispkt) == 0)
6592 do_ssh2_authconn(ssh, in, inlen, ispkt);
6596 * Called to set up the connection.
6598 * Returns an error message, or NULL on success.
6600 static const char *ssh_init(void *frontend_handle, void **backend_handle,
6602 char *host, int port, char **realhost, int nodelay,
6608 ssh = snew(struct ssh_tag);
6609 ssh->cfg = *cfg; /* STRUCTURE COPY */
6610 ssh->version = 0; /* when not ready yet */
6613 ssh->v1_cipher_ctx = NULL;
6614 ssh->crcda_ctx = NULL;
6615 ssh->cscipher = NULL;
6616 ssh->cs_cipher_ctx = NULL;
6617 ssh->sccipher = NULL;
6618 ssh->sc_cipher_ctx = NULL;
6620 ssh->cs_mac_ctx = NULL;
6622 ssh->sc_mac_ctx = NULL;
6624 ssh->cs_comp_ctx = NULL;
6626 ssh->sc_comp_ctx = NULL;
6628 ssh->kex_ctx = NULL;
6629 ssh->hostkey = NULL;
6631 ssh->state = SSH_STATE_PREPACKET;
6632 ssh->size_needed = FALSE;
6633 ssh->eof_needed = FALSE;
6637 static const struct Packet empty = { 0, 0, NULL, NULL, 0 };
6638 ssh->pktin = ssh->pktout = empty;
6640 ssh->deferred_send_data = NULL;
6641 ssh->deferred_len = 0;
6642 ssh->deferred_size = 0;
6643 ssh->pktout_logmode = PKTLOG_EMIT;
6644 ssh->pktout_nblanks = 0;
6645 ssh->pktout_blanks = NULL;
6646 ssh->fallback_cmd = 0;
6648 ssh->x11auth = NULL;
6649 ssh->v1_compressing = FALSE;
6650 ssh->v2_outgoing_sequence = 0;
6651 ssh->ssh1_rdpkt_crstate = 0;
6652 ssh->ssh2_rdpkt_crstate = 0;
6653 ssh->do_ssh_init_crstate = 0;
6654 ssh->ssh_gotdata_crstate = 0;
6655 ssh->ssh1_protocol_crstate = 0;
6656 ssh->do_ssh1_login_crstate = 0;
6657 ssh->do_ssh2_transport_crstate = 0;
6658 ssh->do_ssh2_authconn_crstate = 0;
6659 ssh->do_ssh_init_state = NULL;
6660 ssh->do_ssh1_login_state = NULL;
6661 ssh->do_ssh2_transport_state = NULL;
6662 ssh->do_ssh2_authconn_state = NULL;
6663 ssh->mainchan = NULL;
6664 ssh->throttled_all = 0;
6665 ssh->v1_stdout_throttling = 0;
6667 *backend_handle = ssh;
6670 if (crypto_startup() == 0)
6671 return "Microsoft high encryption pack not installed!";
6674 ssh->frontend = frontend_handle;
6675 ssh->term_width = ssh->cfg.width;
6676 ssh->term_height = ssh->cfg.height;
6678 ssh->channels = NULL;
6679 ssh->rportfwds = NULL;
6684 ssh->v1_throttle_count = 0;
6685 ssh->overall_bufsize = 0;
6686 ssh->fallback_cmd = 0;
6688 ssh->protocol = NULL;
6690 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
6697 static void ssh_free(void *handle)
6699 Ssh ssh = (Ssh) handle;
6700 struct ssh_channel *c;
6701 struct ssh_rportfwd *pf;
6703 if (ssh->v1_cipher_ctx)
6704 ssh->cipher->free_context(ssh->v1_cipher_ctx);
6705 if (ssh->cs_cipher_ctx)
6706 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6707 if (ssh->sc_cipher_ctx)
6708 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6709 if (ssh->cs_mac_ctx)
6710 ssh->csmac->free_context(ssh->cs_mac_ctx);
6711 if (ssh->sc_mac_ctx)
6712 ssh->scmac->free_context(ssh->sc_mac_ctx);
6713 if (ssh->cs_comp_ctx) {
6715 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6717 zlib_compress_cleanup(ssh->cs_comp_ctx);
6719 if (ssh->sc_comp_ctx) {
6721 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
6723 zlib_decompress_cleanup(ssh->sc_comp_ctx);
6726 dh_cleanup(ssh->kex_ctx);
6727 sfree(ssh->savedhost);
6729 if (ssh->channels) {
6730 while ((c = delpos234(ssh->channels, 0)) != NULL) {
6733 if (c->u.x11.s != NULL)
6734 x11_close(c->u.x11.s);
6737 if (c->u.pfd.s != NULL)
6738 pfd_close(c->u.pfd.s);
6743 freetree234(ssh->channels);
6746 if (ssh->rportfwds) {
6747 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
6749 freetree234(ssh->rportfwds);
6751 sfree(ssh->deferred_send_data);
6753 x11_free_auth(ssh->x11auth);
6754 sfree(ssh->do_ssh_init_state);
6755 sfree(ssh->do_ssh1_login_state);
6756 sfree(ssh->do_ssh2_transport_state);
6757 sfree(ssh->do_ssh2_authconn_state);
6758 if (ssh->pktout.data) {
6759 sfree(ssh->pktout.data);
6760 ssh->pktout.data = NULL;
6762 if (ssh->pktin.data) {
6763 sfree(ssh->pktin.data);
6764 ssh->pktin.data = NULL;
6766 if (ssh->crcda_ctx) {
6767 crcda_free_context(ssh->crcda_ctx);
6768 ssh->crcda_ctx = NULL;
6776 * Reconfigure the SSH backend.
6778 * Currently, this function does nothing very useful. In future,
6779 * however, we could do some handy things with it. For example, we
6780 * could make the port forwarding configurer active in the Change
6781 * Settings box, and this routine could close down existing
6782 * forwardings and open up new ones in response to changes.
6784 static void ssh_reconfig(void *handle, Config *cfg)
6786 Ssh ssh = (Ssh) handle;
6787 ssh->cfg = *cfg; /* STRUCTURE COPY */
6791 * Called to send data down the Telnet connection.
6793 static int ssh_send(void *handle, char *buf, int len)
6795 Ssh ssh = (Ssh) handle;
6797 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
6800 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
6802 return ssh_sendbuffer(ssh);
6806 * Called to query the current amount of buffered stdin data.
6808 static int ssh_sendbuffer(void *handle)
6810 Ssh ssh = (Ssh) handle;
6813 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
6817 * If the SSH socket itself has backed up, add the total backup
6818 * size on that to any individual buffer on the stdin channel.
6821 if (ssh->throttled_all)
6822 override_value = ssh->overall_bufsize;
6824 if (ssh->version == 1) {
6825 return override_value;
6826 } else if (ssh->version == 2) {
6827 if (!ssh->mainchan || ssh->mainchan->closes > 0)
6828 return override_value;
6830 return (override_value +
6831 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
6838 * Called to set the size of the window from SSH's POV.
6840 static void ssh_size(void *handle, int width, int height)
6842 Ssh ssh = (Ssh) handle;
6844 ssh->term_width = width;
6845 ssh->term_height = height;
6847 switch (ssh->state) {
6848 case SSH_STATE_BEFORE_SIZE:
6849 case SSH_STATE_PREPACKET:
6850 case SSH_STATE_CLOSED:
6851 break; /* do nothing */
6852 case SSH_STATE_INTERMED:
6853 ssh->size_needed = TRUE; /* buffer for later */
6855 case SSH_STATE_SESSION:
6856 if (!ssh->cfg.nopty) {
6857 if (ssh->version == 1) {
6858 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
6859 PKT_INT, ssh->term_height,
6860 PKT_INT, ssh->term_width,
6861 PKT_INT, 0, PKT_INT, 0, PKT_END);
6862 } else if (ssh->mainchan) {
6863 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6864 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6865 ssh2_pkt_addstring(ssh, "window-change");
6866 ssh2_pkt_addbool(ssh, 0);
6867 ssh2_pkt_adduint32(ssh, ssh->term_width);
6868 ssh2_pkt_adduint32(ssh, ssh->term_height);
6869 ssh2_pkt_adduint32(ssh, 0);
6870 ssh2_pkt_adduint32(ssh, 0);
6879 * Return a list of the special codes that make sense in this
6882 static const struct telnet_special *ssh_get_specials(void *handle)
6884 static const struct telnet_special ignore_special[] = {
6885 {"IGNORE message", TS_NOP},
6887 static const struct telnet_special ssh2_session_specials[] = {
6890 /* These are the signal names defined by draft-ietf-secsh-connect-19.
6891 * They include all the ISO C signals, but are a subset of the POSIX
6892 * required signals. */
6893 {"SIGINT (Interrupt)", TS_SIGINT},
6894 {"SIGTERM (Terminate)", TS_SIGTERM},
6895 {"SIGKILL (Kill)", TS_SIGKILL},
6896 {"SIGQUIT (Quit)", TS_SIGQUIT},
6897 {"SIGHUP (Hangup)", TS_SIGHUP},
6898 {"More signals", TS_SUBMENU},
6899 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
6900 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
6901 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
6902 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
6905 static const struct telnet_special specials_end[] = {
6908 static struct telnet_special ssh_specials[lenof(ignore_special) +
6909 lenof(ssh2_session_specials) +
6910 lenof(specials_end)];
6911 Ssh ssh = (Ssh) handle;
6913 #define ADD_SPECIALS(name) \
6915 assert((i + lenof(name)) <= lenof(ssh_specials)); \
6916 memcpy(&ssh_specials[i], name, sizeof name); \
6920 if (ssh->version == 1) {
6921 /* Don't bother offering IGNORE if we've decided the remote
6922 * won't cope with it, since we wouldn't bother sending it if
6924 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
6925 ADD_SPECIALS(ignore_special);
6926 } else if (ssh->version == 2) {
6927 /* XXX add rekey, when implemented */
6928 ADD_SPECIALS(ignore_special);
6930 ADD_SPECIALS(ssh2_session_specials);
6931 } /* else we're not ready yet */
6934 ADD_SPECIALS(specials_end);
6935 return ssh_specials;
6943 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6944 * can send an EOF and collect resulting output (e.g. `plink
6947 static void ssh_special(void *handle, Telnet_Special code)
6949 Ssh ssh = (Ssh) handle;
6951 if (code == TS_EOF) {
6952 if (ssh->state != SSH_STATE_SESSION) {
6954 * Buffer the EOF in case we are pre-SESSION, so we can
6955 * send it as soon as we reach SESSION.
6958 ssh->eof_needed = TRUE;
6961 if (ssh->version == 1) {
6962 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
6963 } else if (ssh->mainchan) {
6964 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_EOF);
6965 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6968 logevent("Sent EOF message");
6969 } else if (code == TS_PING || code == TS_NOP) {
6970 if (ssh->state == SSH_STATE_CLOSED
6971 || ssh->state == SSH_STATE_PREPACKET) return;
6972 if (ssh->version == 1) {
6973 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
6974 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
6976 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
6977 ssh2_pkt_addstring_start(ssh);
6980 } else if (code == TS_BRK) {
6981 if (ssh->state == SSH_STATE_CLOSED
6982 || ssh->state == SSH_STATE_PREPACKET) return;
6983 if (ssh->version == 1) {
6984 logevent("Unable to send BREAK signal in SSH1");
6985 } else if (ssh->mainchan) {
6986 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6987 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6988 ssh2_pkt_addstring(ssh, "break");
6989 ssh2_pkt_addbool(ssh, 0);
6990 ssh2_pkt_adduint32(ssh, 0); /* default break length */
6994 /* Is is a POSIX signal? */
6995 char *signame = NULL;
6996 if (code == TS_SIGABRT) signame = "ABRT";
6997 if (code == TS_SIGALRM) signame = "ALRM";
6998 if (code == TS_SIGFPE) signame = "FPE";
6999 if (code == TS_SIGHUP) signame = "HUP";
7000 if (code == TS_SIGILL) signame = "ILL";
7001 if (code == TS_SIGINT) signame = "INT";
7002 if (code == TS_SIGKILL) signame = "KILL";
7003 if (code == TS_SIGPIPE) signame = "PIPE";
7004 if (code == TS_SIGQUIT) signame = "QUIT";
7005 if (code == TS_SIGSEGV) signame = "SEGV";
7006 if (code == TS_SIGTERM) signame = "TERM";
7007 if (code == TS_SIGUSR1) signame = "USR1";
7008 if (code == TS_SIGUSR2) signame = "USR2";
7009 /* The SSH-2 protocol does in principle support arbitrary named
7010 * signals, including signame@domain, but we don't support those. */
7012 /* It's a signal. */
7013 if (ssh->version == 2 && ssh->mainchan) {
7014 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
7015 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
7016 ssh2_pkt_addstring(ssh, "signal");
7017 ssh2_pkt_addbool(ssh, 0);
7018 ssh2_pkt_addstring(ssh, signame);
7020 logeventf(ssh, "Sent signal SIG%s", signame);
7023 /* Never heard of it. Do nothing */
7028 void *new_sock_channel(void *handle, Socket s)
7030 Ssh ssh = (Ssh) handle;
7031 struct ssh_channel *c;
7032 c = snew(struct ssh_channel);
7036 c->remoteid = -1; /* to be set when open confirmed */
7037 c->localid = alloc_channel_id(ssh);
7039 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
7041 bufchain_init(&c->v.v2.outbuffer);
7042 add234(ssh->channels, c);
7048 * This is called when stdout/stderr (the entity to which
7049 * from_backend sends data) manages to clear some backlog.
7051 static void ssh_unthrottle(void *handle, int bufsize)
7053 Ssh ssh = (Ssh) handle;
7054 if (ssh->version == 1) {
7055 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
7056 ssh->v1_stdout_throttling = 0;
7057 ssh1_throttle(ssh, -1);
7060 if (ssh->mainchan && ssh->mainchan->closes == 0)
7061 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
7065 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
7067 struct ssh_channel *c = (struct ssh_channel *)channel;
7070 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
7072 if (ssh->version == 1) {
7073 send_packet(ssh, SSH1_MSG_PORT_OPEN,
7074 PKT_INT, c->localid,
7077 //PKT_STR, <org:orgport>,
7080 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
7081 ssh2_pkt_addstring(ssh, "direct-tcpip");
7082 ssh2_pkt_adduint32(ssh, c->localid);
7083 c->v.v2.locwindow = OUR_V2_WINSIZE;
7084 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);/* our window size */
7085 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
7086 ssh2_pkt_addstring(ssh, hostname);
7087 ssh2_pkt_adduint32(ssh, port);
7089 * We make up values for the originator data; partly it's
7090 * too much hassle to keep track, and partly I'm not
7091 * convinced the server should be told details like that
7092 * about my local network configuration.
7094 ssh2_pkt_addstring(ssh, "client-side-connection");
7095 ssh2_pkt_adduint32(ssh, 0);
7101 static Socket ssh_socket(void *handle)
7103 Ssh ssh = (Ssh) handle;
7107 static int ssh_sendok(void *handle)
7109 Ssh ssh = (Ssh) handle;
7110 return ssh->send_ok;
7113 static int ssh_ldisc(void *handle, int option)
7115 Ssh ssh = (Ssh) handle;
7116 if (option == LD_ECHO)
7117 return ssh->echoing;
7118 if (option == LD_EDIT)
7119 return ssh->editing;
7123 static void ssh_provide_ldisc(void *handle, void *ldisc)
7125 Ssh ssh = (Ssh) handle;
7129 static void ssh_provide_logctx(void *handle, void *logctx)
7131 Ssh ssh = (Ssh) handle;
7132 ssh->logctx = logctx;
7135 static int ssh_return_exitcode(void *handle)
7137 Ssh ssh = (Ssh) handle;
7141 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
7145 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
7146 * that fails. This variable is the means by which scp.c can reach
7147 * into the SSH code and find out which one it got.
7149 extern int ssh_fallback_cmd(void *handle)
7151 Ssh ssh = (Ssh) handle;
7152 return ssh->fallback_cmd;
7155 Backend ssh_backend = {
7165 ssh_return_exitcode,