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 enum { PKT_END
, PKT_INT
, PKT_CHAR
, PKT_DATA
, PKT_STR
, PKT_BIGNUM
};
273 * Coroutine mechanics for the sillier bits of the code. If these
274 * macros look impenetrable to you, you might find it helpful to
277 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
279 * which explains the theory behind these macros.
281 * In particular, if you are getting `case expression not constant'
282 * errors when building with MS Visual Studio, this is because MS's
283 * Edit and Continue debugging feature causes their compiler to
284 * violate ANSI C. To disable Edit and Continue debugging:
286 * - right-click ssh.c in the FileView
288 * - select the C/C++ tab and the General category
289 * - under `Debug info:', select anything _other_ than `Program
290 * Database for Edit and Continue'.
292 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
295 if (!ssh->t) ssh->t = snew(struct t); \
297 #define crFinish(z) } *crLine = 0; return (z); }
298 #define crFinishV } *crLine = 0; return; }
299 #define crReturn(z) \
301 *crLine =__LINE__; return (z); case __LINE__:;\
305 *crLine=__LINE__; return; case __LINE__:;\
307 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
308 #define crStopV do{ *crLine = 0; return; }while(0)
309 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
310 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
312 typedef struct ssh_tag
*Ssh
;
314 static void ssh2_pkt_init(Ssh
, int pkt_type
);
315 static void ssh2_pkt_addbool(Ssh
, unsigned char value
);
316 static void ssh2_pkt_adduint32(Ssh
, unsigned long value
);
317 static void ssh2_pkt_addstring_start(Ssh
);
318 static void ssh2_pkt_addstring_str(Ssh
, char *data
);
319 static void ssh2_pkt_addstring_data(Ssh
, char *data
, int len
);
320 static void ssh2_pkt_addstring(Ssh
, char *data
);
321 static unsigned char *ssh2_mpint_fmt(Bignum b
, int *len
);
322 static void ssh2_pkt_addmp(Ssh
, Bignum b
);
323 static int ssh2_pkt_construct(Ssh
);
324 static void ssh2_pkt_send(Ssh
);
327 * Buffer management constants. There are several of these for
328 * various different purposes:
330 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
331 * on a local data stream before we throttle the whole SSH
332 * connection (in SSH1 only). Throttling the whole connection is
333 * pretty drastic so we set this high in the hope it won't
336 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
337 * on the SSH connection itself before we defensively throttle
338 * _all_ local data streams. This is pretty drastic too (though
339 * thankfully unlikely in SSH2 since the window mechanism should
340 * ensure that the server never has any need to throttle its end
341 * of the connection), so we set this high as well.
343 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
347 #define SSH1_BUFFER_LIMIT 32768
348 #define SSH_MAX_BACKLOG 32768
349 #define OUR_V2_WINSIZE 16384
351 const static struct ssh_kex
*kex_algs
[] = {
352 &ssh_diffiehellman_gex
,
356 const static struct ssh_signkey
*hostkey_algs
[] = { &ssh_rsa
, &ssh_dss
};
358 static void *nullmac_make_context(void)
362 static void nullmac_free_context(void *handle
)
365 static void nullmac_key(void *handle
, unsigned char *key
)
368 static void nullmac_generate(void *handle
, unsigned char *blk
, int len
,
372 static int nullmac_verify(void *handle
, unsigned char *blk
, int len
,
377 const static struct ssh_mac ssh_mac_none
= {
378 nullmac_make_context
, nullmac_free_context
, nullmac_key
,
379 nullmac_generate
, nullmac_verify
, "none", 0
381 const static struct ssh_mac
*macs
[] = {
382 &ssh_sha1
, &ssh_md5
, &ssh_mac_none
384 const static struct ssh_mac
*buggymacs
[] = {
385 &ssh_sha1_buggy
, &ssh_md5
, &ssh_mac_none
388 static void *ssh_comp_none_init(void)
392 static void ssh_comp_none_cleanup(void *handle
)
395 static int ssh_comp_none_block(void *handle
, unsigned char *block
, int len
,
396 unsigned char **outblock
, int *outlen
)
400 static int ssh_comp_none_disable(void *handle
)
404 const static struct ssh_compress ssh_comp_none
= {
406 ssh_comp_none_init
, ssh_comp_none_cleanup
, ssh_comp_none_block
,
407 ssh_comp_none_init
, ssh_comp_none_cleanup
, ssh_comp_none_block
,
408 ssh_comp_none_disable
, NULL
410 extern const struct ssh_compress ssh_zlib
;
411 const static struct ssh_compress
*compressions
[] = {
412 &ssh_zlib
, &ssh_comp_none
415 enum { /* channel types */
420 CHAN_SOCKDATA_DORMANT
/* one the remote hasn't confirmed */
424 * 2-3-4 tree storing channels.
427 Ssh ssh
; /* pointer back to main context */
428 unsigned remoteid
, localid
;
431 * In SSH1, this value contains four bits:
433 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
434 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
435 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
436 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
438 * A channel is completely finished with when all four bits are set.
442 struct ssh1_data_channel
{
445 struct ssh2_data_channel
{
447 unsigned remwindow
, remmaxpkt
;
452 struct ssh_agent_channel
{
453 unsigned char *message
;
454 unsigned char msglen
[4];
455 int lensofar
, totallen
;
457 struct ssh_x11_channel
{
460 struct ssh_pfd_channel
{
467 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
468 * 2 use this structure in different ways, reflecting SSH 2's
469 * altogether saner approach to port forwarding.
471 * In SSH 1, you arrange a remote forwarding by sending the server
472 * the remote port number, and the local destination host:port.
473 * When a connection comes in, the server sends you back that
474 * host:port pair, and you connect to it. This is a ready-made
475 * security hole if you're not on the ball: a malicious server
476 * could send you back _any_ host:port pair, so if you trustingly
477 * connect to the address it gives you then you've just opened the
478 * entire inside of your corporate network just by connecting
479 * through it to a dodgy SSH server. Hence, we must store a list of
480 * host:port pairs we _are_ trying to forward to, and reject a
481 * connection request from the server if it's not in the list.
483 * In SSH 2, each side of the connection minds its own business and
484 * doesn't send unnecessary information to the other. You arrange a
485 * remote forwarding by sending the server just the remote port
486 * number. When a connection comes in, the server tells you which
487 * of its ports was connected to; and _you_ have to remember what
488 * local host:port pair went with that port number.
490 * Hence: in SSH 1 this structure stores host:port pairs we intend
491 * to allow connections to, and is indexed by those host:port
492 * pairs. In SSH 2 it stores a mapping from source port to
493 * destination host:port pair, and is indexed by source port.
495 struct ssh_rportfwd
{
496 unsigned sport
, dport
;
509 static void ssh1_protocol(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
);
510 static void ssh2_protocol(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
);
511 static void ssh_size(void *handle
, int width
, int height
);
512 static void ssh_special(void *handle
, Telnet_Special
);
513 static int ssh2_try_send(struct ssh_channel
*c
);
514 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
, int len
);
515 static void ssh_throttle_all(Ssh ssh
, int enable
, int bufsize
);
516 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
);
517 static int ssh_sendbuffer(void *handle
);
519 struct rdpkt1_state_tag
{
520 long len
, pad
, biglen
, to_read
;
521 unsigned long realcrc
, gotcrc
;
527 struct rdpkt2_state_tag
{
528 long len
, pad
, payload
, packetlen
, maclen
;
531 unsigned long incoming_sequence
;
535 const struct plug_function_table
*fn
;
536 /* the above field _must_ be first in the structure */
538 SHA_State exhash
, exhashbase
;
545 unsigned char session_key
[32];
547 int v1_remote_protoflags
;
548 int v1_local_protoflags
;
549 int agentfwd_enabled
;
552 const struct ssh_cipher
*cipher
;
555 const struct ssh2_cipher
*cscipher
, *sccipher
;
556 void *cs_cipher_ctx
, *sc_cipher_ctx
;
557 const struct ssh_mac
*csmac
, *scmac
;
558 void *cs_mac_ctx
, *sc_mac_ctx
;
559 const struct ssh_compress
*cscomp
, *sccomp
;
560 void *cs_comp_ctx
, *sc_comp_ctx
;
561 const struct ssh_kex
*kex
;
562 const struct ssh_signkey
*hostkey
;
563 unsigned char v2_session_id
[20];
569 int echoing
, editing
;
573 int term_width
, term_height
;
575 tree234
*channels
; /* indexed by local id */
576 struct ssh_channel
*mainchan
; /* primary session channel */
583 SSH_STATE_BEFORE_SIZE
,
589 int size_needed
, eof_needed
;
592 struct Packet pktout
;
593 unsigned char *deferred_send_data
;
594 int deferred_len
, deferred_size
;
597 * Gross hack: pscp will try to start SFTP but fall back to
598 * scp1 if that fails. This variable is the means by which
599 * scp.c can reach into the SSH code and find out which one it
605 * Used for username and password input.
607 char *userpass_input_buffer
;
608 int userpass_input_buflen
;
609 int userpass_input_bufpos
;
610 int userpass_input_echo
;
612 char *portfwd_strptr
;
618 int v1_throttle_count
;
621 int v1_stdout_throttling
;
622 int v2_outgoing_sequence
;
624 int ssh1_rdpkt_crstate
;
625 int ssh2_rdpkt_crstate
;
626 int do_ssh_init_crstate
;
627 int ssh_gotdata_crstate
;
628 int ssh1_protocol_crstate
;
629 int do_ssh1_login_crstate
;
630 int do_ssh2_transport_crstate
;
631 int do_ssh2_authconn_crstate
;
633 void *do_ssh_init_state
;
634 void *do_ssh1_login_state
;
635 void *do_ssh2_transport_state
;
636 void *do_ssh2_authconn_state
;
638 struct rdpkt1_state_tag rdpkt1_state
;
639 struct rdpkt2_state_tag rdpkt2_state
;
641 void (*protocol
) (Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
);
642 int (*s_rdpkt
) (Ssh ssh
, unsigned char **data
, int *datalen
);
645 * We maintain a full _copy_ of a Config structure here, not
646 * merely a pointer to it. That way, when we're passed a new
647 * one for reconfiguration, we can check the differences and
648 * potentially reconfigure port forwardings etc in mid-session.
653 #define logevent(s) logevent(ssh->frontend, s)
655 /* logevent, only printf-formatted. */
656 static void logeventf(Ssh ssh
, char *fmt
, ...)
662 buf
= dupvprintf(fmt
, ap
);
668 #define bombout(msg) \
670 char *text = dupprintf msg; \
671 ssh->state = SSH_STATE_CLOSED; \
672 if (ssh->s) { sk_close(ssh->s); ssh->s = NULL; } \
674 connection_fatal(ssh->frontend, "%s", text); \
678 static int ssh_channelcmp(void *av
, void *bv
)
680 struct ssh_channel
*a
= (struct ssh_channel
*) av
;
681 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
682 if (a
->localid
< b
->localid
)
684 if (a
->localid
> b
->localid
)
688 static int ssh_channelfind(void *av
, void *bv
)
690 unsigned *a
= (unsigned *) av
;
691 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
699 static int ssh_rportcmp_ssh1(void *av
, void *bv
)
701 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
702 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
704 if ( (i
= strcmp(a
->dhost
, b
->dhost
)) != 0)
705 return i
< 0 ?
-1 : +1;
706 if (a
->dport
> b
->dport
)
708 if (a
->dport
< b
->dport
)
713 static int ssh_rportcmp_ssh2(void *av
, void *bv
)
715 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
716 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
718 if (a
->sport
> b
->sport
)
720 if (a
->sport
< b
->sport
)
725 static int alloc_channel_id(Ssh ssh
)
727 const unsigned CHANNEL_NUMBER_OFFSET
= 256;
728 unsigned low
, high
, mid
;
730 struct ssh_channel
*c
;
733 * First-fit allocation of channel numbers: always pick the
734 * lowest unused one. To do this, binary-search using the
735 * counted B-tree to find the largest channel ID which is in a
736 * contiguous sequence from the beginning. (Precisely
737 * everything in that sequence must have ID equal to its tree
738 * index plus CHANNEL_NUMBER_OFFSET.)
740 tsize
= count234(ssh
->channels
);
744 while (high
- low
> 1) {
745 mid
= (high
+ low
) / 2;
746 c
= index234(ssh
->channels
, mid
);
747 if (c
->localid
== mid
+ CHANNEL_NUMBER_OFFSET
)
748 low
= mid
; /* this one is fine */
750 high
= mid
; /* this one is past it */
753 * Now low points to either -1, or the tree index of the
754 * largest ID in the initial sequence.
757 unsigned i
= low
+ 1 + CHANNEL_NUMBER_OFFSET
;
758 assert(NULL
== find234(ssh
->channels
, &i
, ssh_channelfind
));
760 return low
+ 1 + CHANNEL_NUMBER_OFFSET
;
763 static void c_write(Ssh ssh
, const char *buf
, int len
)
765 if ((flags
& FLAG_STDERR
)) {
767 for (i
= 0; i
< len
; i
++)
769 fputc(buf
[i
], stderr
);
772 from_backend(ssh
->frontend
, 1, buf
, len
);
775 static void c_write_untrusted(Ssh ssh
, const char *buf
, int len
)
778 for (i
= 0; i
< len
; i
++) {
780 c_write(ssh
, "\r\n", 2);
781 else if ((buf
[i
] & 0x60) || (buf
[i
] == '\r'))
782 c_write(ssh
, buf
+ i
, 1);
786 static void c_write_str(Ssh ssh
, const char *buf
)
788 c_write(ssh
, buf
, strlen(buf
));
792 * Collect incoming data in the incoming packet buffer.
793 * Decipher and verify the packet when it is completely read.
794 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
795 * Update the *data and *datalen variables.
796 * Return the additional nr of bytes needed, or 0 when
797 * a complete packet is available.
799 static int ssh1_rdpkt(Ssh ssh
, unsigned char **data
, int *datalen
)
801 struct rdpkt1_state_tag
*st
= &ssh
->rdpkt1_state
;
803 crBegin(ssh
->ssh1_rdpkt_crstate
);
808 ssh
->pktin
.length
= 0;
810 for (st
->i
= st
->len
= 0; st
->i
< 4; st
->i
++) {
811 while ((*datalen
) == 0)
813 st
->len
= (st
->len
<< 8) + **data
;
814 (*data
)++, (*datalen
)--;
817 st
->pad
= 8 - (st
->len
% 8);
818 st
->biglen
= st
->len
+ st
->pad
;
819 ssh
->pktin
.length
= st
->len
- 5;
821 if (ssh
->pktin
.maxlen
< st
->biglen
) {
822 ssh
->pktin
.maxlen
= st
->biglen
;
823 ssh
->pktin
.data
= sresize(ssh
->pktin
.data
, st
->biglen
+ APIEXTRA
,
827 st
->to_read
= st
->biglen
;
828 st
->p
= ssh
->pktin
.data
;
829 while (st
->to_read
> 0) {
830 st
->chunk
= st
->to_read
;
831 while ((*datalen
) == 0)
832 crReturn(st
->to_read
);
833 if (st
->chunk
> (*datalen
))
834 st
->chunk
= (*datalen
);
835 memcpy(st
->p
, *data
, st
->chunk
);
837 *datalen
-= st
->chunk
;
839 st
->to_read
-= st
->chunk
;
842 if (ssh
->cipher
&& detect_attack(ssh
->crcda_ctx
, ssh
->pktin
.data
,
844 bombout(("Network attack (CRC compensation) detected!"));
849 ssh
->cipher
->decrypt(ssh
->v1_cipher_ctx
, ssh
->pktin
.data
, st
->biglen
);
851 st
->realcrc
= crc32(ssh
->pktin
.data
, st
->biglen
- 4);
852 st
->gotcrc
= GET_32BIT(ssh
->pktin
.data
+ st
->biglen
- 4);
853 if (st
->gotcrc
!= st
->realcrc
) {
854 bombout(("Incorrect CRC received on packet"));
858 ssh
->pktin
.body
= ssh
->pktin
.data
+ st
->pad
+ 1;
860 if (ssh
->v1_compressing
) {
861 unsigned char *decompblk
;
863 zlib_decompress_block(ssh
->sc_comp_ctx
,
864 ssh
->pktin
.body
- 1, ssh
->pktin
.length
+ 1,
865 &decompblk
, &decomplen
);
867 if (ssh
->pktin
.maxlen
< st
->pad
+ decomplen
) {
868 ssh
->pktin
.maxlen
= st
->pad
+ decomplen
;
869 ssh
->pktin
.data
= sresize(ssh
->pktin
.data
,
870 ssh
->pktin
.maxlen
+ APIEXTRA
,
872 ssh
->pktin
.body
= ssh
->pktin
.data
+ st
->pad
+ 1;
875 memcpy(ssh
->pktin
.body
- 1, decompblk
, decomplen
);
877 ssh
->pktin
.length
= decomplen
- 1;
880 ssh
->pktin
.type
= ssh
->pktin
.body
[-1];
883 log_packet(ssh
->logctx
,
884 PKT_INCOMING
, ssh
->pktin
.type
,
885 ssh1_pkt_type(ssh
->pktin
.type
),
886 ssh
->pktin
.body
, ssh
->pktin
.length
);
888 if (ssh
->pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
889 ssh
->pktin
.type
== SSH1_SMSG_STDERR_DATA
||
890 ssh
->pktin
.type
== SSH1_MSG_DEBUG
||
891 ssh
->pktin
.type
== SSH1_SMSG_AUTH_TIS_CHALLENGE
||
892 ssh
->pktin
.type
== SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
893 long stringlen
= GET_32BIT(ssh
->pktin
.body
);
894 if (stringlen
+ 4 != ssh
->pktin
.length
) {
895 bombout(("Received data packet with bogus string length"));
900 if (ssh
->pktin
.type
== SSH1_MSG_DEBUG
) {
901 /* log debug message */
903 int stringlen
= GET_32BIT(ssh
->pktin
.body
);
904 strcpy(buf
, "Remote debug message: ");
907 memcpy(buf
+ 8, ssh
->pktin
.body
+ 4, stringlen
);
908 buf
[8 + stringlen
] = '\0';
911 } else if (ssh
->pktin
.type
== SSH1_MSG_IGNORE
) {
916 if (ssh
->pktin
.type
== SSH1_MSG_DISCONNECT
) {
917 /* log reason code in disconnect message */
919 unsigned msglen
= GET_32BIT(ssh
->pktin
.body
);
921 strcpy(buf
, "Remote sent disconnect: ");
922 nowlen
= strlen(buf
);
923 if (msglen
> sizeof(buf
) - nowlen
- 1)
924 msglen
= sizeof(buf
) - nowlen
- 1;
925 memcpy(buf
+ nowlen
, ssh
->pktin
.body
+ 4, msglen
);
926 buf
[nowlen
+ msglen
] = '\0';
927 /* logevent(buf); (this is now done within the bombout macro) */
928 bombout(("Server sent disconnect message:\n\"%s\"", buf
+nowlen
));
935 static int ssh2_rdpkt(Ssh ssh
, unsigned char **data
, int *datalen
)
937 struct rdpkt2_state_tag
*st
= &ssh
->rdpkt2_state
;
939 crBegin(ssh
->ssh2_rdpkt_crstate
);
943 ssh
->pktin
.length
= 0;
945 st
->cipherblk
= ssh
->sccipher
->blksize
;
948 if (st
->cipherblk
< 8)
951 if (ssh
->pktin
.maxlen
< st
->cipherblk
) {
952 ssh
->pktin
.maxlen
= st
->cipherblk
;
953 ssh
->pktin
.data
= sresize(ssh
->pktin
.data
, st
->cipherblk
+ APIEXTRA
,
958 * Acquire and decrypt the first block of the packet. This will
959 * contain the length and padding details.
961 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
962 while ((*datalen
) == 0)
963 crReturn(st
->cipherblk
- st
->i
);
964 ssh
->pktin
.data
[st
->i
] = *(*data
)++;
969 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
970 ssh
->pktin
.data
, st
->cipherblk
);
973 * Now get the length and padding figures.
975 st
->len
= GET_32BIT(ssh
->pktin
.data
);
976 st
->pad
= ssh
->pktin
.data
[4];
979 * _Completely_ silly lengths should be stomped on before they
980 * do us any more damage.
982 if (st
->len
< 0 || st
->pad
< 0 || st
->len
+ st
->pad
< 0) {
983 bombout(("Incoming packet was garbled on decryption"));
988 * This enables us to deduce the payload length.
990 st
->payload
= st
->len
- st
->pad
- 1;
992 ssh
->pktin
.length
= st
->payload
+ 5;
995 * So now we can work out the total packet length.
997 st
->packetlen
= st
->len
+ 4;
998 st
->maclen
= ssh
->scmac ? ssh
->scmac
->len
: 0;
1001 * Adjust memory allocation if packet is too big.
1003 if (ssh
->pktin
.maxlen
< st
->packetlen
+ st
->maclen
) {
1004 ssh
->pktin
.maxlen
= st
->packetlen
+ st
->maclen
;
1005 ssh
->pktin
.data
= sresize(ssh
->pktin
.data
,
1006 ssh
->pktin
.maxlen
+ APIEXTRA
,
1011 * Read and decrypt the remainder of the packet.
1013 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
;
1015 while ((*datalen
) == 0)
1016 crReturn(st
->packetlen
+ st
->maclen
- st
->i
);
1017 ssh
->pktin
.data
[st
->i
] = *(*data
)++;
1020 /* Decrypt everything _except_ the MAC. */
1022 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
1023 ssh
->pktin
.data
+ st
->cipherblk
,
1024 st
->packetlen
- st
->cipherblk
);
1030 && !ssh
->scmac
->verify(ssh
->sc_mac_ctx
, ssh
->pktin
.data
, st
->len
+ 4,
1031 st
->incoming_sequence
)) {
1032 bombout(("Incorrect MAC received on packet"));
1035 st
->incoming_sequence
++; /* whether or not we MACed */
1038 * Decompress packet payload.
1041 unsigned char *newpayload
;
1044 ssh
->sccomp
->decompress(ssh
->sc_comp_ctx
,
1045 ssh
->pktin
.data
+ 5, ssh
->pktin
.length
- 5,
1046 &newpayload
, &newlen
)) {
1047 if (ssh
->pktin
.maxlen
< newlen
+ 5) {
1048 ssh
->pktin
.maxlen
= newlen
+ 5;
1049 ssh
->pktin
.data
= sresize(ssh
->pktin
.data
,
1050 ssh
->pktin
.maxlen
+ APIEXTRA
,
1053 ssh
->pktin
.length
= 5 + newlen
;
1054 memcpy(ssh
->pktin
.data
+ 5, newpayload
, newlen
);
1059 ssh
->pktin
.savedpos
= 6;
1060 ssh
->pktin
.type
= ssh
->pktin
.data
[5];
1063 log_packet(ssh
->logctx
, PKT_INCOMING
, ssh
->pktin
.type
,
1064 ssh2_pkt_type(ssh
->pkt_ctx
, ssh
->pktin
.type
),
1065 ssh
->pktin
.data
+6, ssh
->pktin
.length
-6);
1067 switch (ssh
->pktin
.type
) {
1069 * These packets we must handle instantly.
1071 case SSH2_MSG_DISCONNECT
:
1073 /* log reason code in disconnect message */
1076 int reason
= GET_32BIT(ssh
->pktin
.data
+ 6);
1077 unsigned msglen
= GET_32BIT(ssh
->pktin
.data
+ 10);
1079 if (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) {
1080 buf
= dupprintf("Received disconnect message (%s)",
1081 ssh2_disconnect_reasons
[reason
]);
1083 buf
= dupprintf("Received disconnect message (unknown"
1084 " type %d)", reason
);
1088 buf
= dupprintf("Disconnection message text: %n%.*s",
1089 &nowlen
, msglen
, ssh
->pktin
.data
+ 14);
1091 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1093 (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) ?
1094 ssh2_disconnect_reasons
[reason
] : "unknown",
1100 case SSH2_MSG_IGNORE
:
1102 case SSH2_MSG_DEBUG
:
1104 /* log the debug message */
1106 /* int display = ssh->pktin.body[6]; */
1107 int stringlen
= GET_32BIT(ssh
->pktin
.data
+7);
1109 strcpy(buf
, "Remote debug message: ");
1110 prefix
= strlen(buf
);
1111 if (stringlen
> (int)(sizeof(buf
)-prefix
-1))
1112 stringlen
= sizeof(buf
)-prefix
-1;
1113 memcpy(buf
+ prefix
, ssh
->pktin
.data
+ 11, stringlen
);
1114 buf
[prefix
+ stringlen
] = '\0';
1117 goto next_packet
; /* FIXME: print the debug message */
1120 * These packets we need do nothing about here.
1122 case SSH2_MSG_UNIMPLEMENTED
:
1123 case SSH2_MSG_SERVICE_REQUEST
:
1124 case SSH2_MSG_SERVICE_ACCEPT
:
1125 case SSH2_MSG_KEXINIT
:
1126 case SSH2_MSG_NEWKEYS
:
1127 case SSH2_MSG_KEXDH_INIT
:
1128 case SSH2_MSG_KEXDH_REPLY
:
1129 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1130 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1131 case SSH2_MSG_KEX_DH_GEX_INIT
:
1132 case SSH2_MSG_KEX_DH_GEX_REPLY
:
1133 case SSH2_MSG_USERAUTH_REQUEST
:
1134 case SSH2_MSG_USERAUTH_FAILURE
:
1135 case SSH2_MSG_USERAUTH_SUCCESS
:
1136 case SSH2_MSG_USERAUTH_BANNER
:
1137 case SSH2_MSG_USERAUTH_PK_OK
:
1138 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1139 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1140 case SSH2_MSG_USERAUTH_INFO_RESPONSE
:
1141 case SSH2_MSG_GLOBAL_REQUEST
:
1142 case SSH2_MSG_REQUEST_SUCCESS
:
1143 case SSH2_MSG_REQUEST_FAILURE
:
1144 case SSH2_MSG_CHANNEL_OPEN
:
1145 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
:
1146 case SSH2_MSG_CHANNEL_OPEN_FAILURE
:
1147 case SSH2_MSG_CHANNEL_WINDOW_ADJUST
:
1148 case SSH2_MSG_CHANNEL_DATA
:
1149 case SSH2_MSG_CHANNEL_EXTENDED_DATA
:
1150 case SSH2_MSG_CHANNEL_EOF
:
1151 case SSH2_MSG_CHANNEL_CLOSE
:
1152 case SSH2_MSG_CHANNEL_REQUEST
:
1153 case SSH2_MSG_CHANNEL_SUCCESS
:
1154 case SSH2_MSG_CHANNEL_FAILURE
:
1158 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1161 ssh2_pkt_init(ssh
, SSH2_MSG_UNIMPLEMENTED
);
1162 ssh2_pkt_adduint32(ssh
, st
->incoming_sequence
- 1);
1170 static void ssh1_pktout_size(Ssh ssh
, int len
)
1174 len
+= 5; /* type and CRC */
1175 pad
= 8 - (len
% 8);
1178 ssh
->pktout
.length
= len
- 5;
1179 if (ssh
->pktout
.maxlen
< biglen
) {
1180 ssh
->pktout
.maxlen
= biglen
;
1182 /* Allocate enough buffer space for extra block
1183 * for MS CryptEncrypt() */
1184 ssh
->pktout
.data
= sresize(ssh
->pktout
.data
, biglen
+ 12,
1187 ssh
->pktout
.data
= sresize(ssh
->pktout
.data
, biglen
+ 4,
1191 ssh
->pktout
.body
= ssh
->pktout
.data
+ 4 + pad
+ 1;
1194 static void s_wrpkt_start(Ssh ssh
, int type
, int len
)
1196 ssh1_pktout_size(ssh
, len
);
1197 ssh
->pktout
.type
= type
;
1200 static int s_wrpkt_prepare(Ssh ssh
)
1206 * XXX various versions of SC (including 8.8.4) screw up the
1207 * register allocation in this function and use the same register
1208 * (D6) for len and as a temporary, with predictable results. The
1209 * following sledgehammer prevents this.
1215 ssh
->pktout
.body
[-1] = ssh
->pktout
.type
;
1218 log_packet(ssh
->logctx
, PKT_OUTGOING
, ssh
->pktout
.type
,
1219 ssh1_pkt_type(ssh
->pktout
.type
),
1220 ssh
->pktout
.body
, ssh
->pktout
.length
);
1222 if (ssh
->v1_compressing
) {
1223 unsigned char *compblk
;
1225 zlib_compress_block(ssh
->cs_comp_ctx
,
1226 ssh
->pktout
.body
- 1, ssh
->pktout
.length
+ 1,
1227 &compblk
, &complen
);
1228 ssh1_pktout_size(ssh
, complen
- 1);
1229 memcpy(ssh
->pktout
.body
- 1, compblk
, complen
);
1233 len
= ssh
->pktout
.length
+ 5; /* type and CRC */
1234 pad
= 8 - (len
% 8);
1237 for (i
= 0; i
< pad
; i
++)
1238 ssh
->pktout
.data
[i
+ 4] = random_byte();
1239 crc
= crc32(ssh
->pktout
.data
+ 4, biglen
- 4);
1240 PUT_32BIT(ssh
->pktout
.data
+ biglen
, crc
);
1241 PUT_32BIT(ssh
->pktout
.data
, len
);
1244 ssh
->cipher
->encrypt(ssh
->v1_cipher_ctx
, ssh
->pktout
.data
+ 4, biglen
);
1249 static void s_wrpkt(Ssh ssh
)
1252 len
= s_wrpkt_prepare(ssh
);
1253 backlog
= sk_write(ssh
->s
, (char *)ssh
->pktout
.data
, len
);
1254 if (backlog
> SSH_MAX_BACKLOG
)
1255 ssh_throttle_all(ssh
, 1, backlog
);
1258 static void s_wrpkt_defer(Ssh ssh
)
1261 len
= s_wrpkt_prepare(ssh
);
1262 if (ssh
->deferred_len
+ len
> ssh
->deferred_size
) {
1263 ssh
->deferred_size
= ssh
->deferred_len
+ len
+ 128;
1264 ssh
->deferred_send_data
= sresize(ssh
->deferred_send_data
,
1268 memcpy(ssh
->deferred_send_data
+ ssh
->deferred_len
, ssh
->pktout
.data
, len
);
1269 ssh
->deferred_len
+= len
;
1273 * Construct a packet with the specified contents.
1275 static void construct_packet(Ssh ssh
, int pkttype
, va_list ap1
, va_list ap2
)
1277 unsigned char *p
, *argp
, argchar
;
1278 unsigned long argint
;
1279 int pktlen
, argtype
, arglen
;
1283 while ((argtype
= va_arg(ap1
, int)) != PKT_END
) {
1286 (void) va_arg(ap1
, int);
1290 (void) va_arg(ap1
, int);
1294 (void) va_arg(ap1
, unsigned char *);
1295 arglen
= va_arg(ap1
, int);
1299 argp
= va_arg(ap1
, unsigned char *);
1300 arglen
= strlen((char *)argp
);
1301 pktlen
+= 4 + arglen
;
1304 bn
= va_arg(ap1
, Bignum
);
1305 pktlen
+= ssh1_bignum_length(bn
);
1312 s_wrpkt_start(ssh
, pkttype
, pktlen
);
1313 p
= ssh
->pktout
.body
;
1315 while ((argtype
= va_arg(ap2
, int)) != PKT_END
) {
1318 argint
= va_arg(ap2
, int);
1319 PUT_32BIT(p
, argint
);
1323 argchar
= (unsigned char) va_arg(ap2
, int);
1328 argp
= va_arg(ap2
, unsigned char *);
1329 arglen
= va_arg(ap2
, int);
1330 memcpy(p
, argp
, arglen
);
1334 argp
= va_arg(ap2
, unsigned char *);
1335 arglen
= strlen((char *)argp
);
1336 PUT_32BIT(p
, arglen
);
1337 memcpy(p
+ 4, argp
, arglen
);
1341 bn
= va_arg(ap2
, Bignum
);
1342 p
+= ssh1_write_bignum(p
, bn
);
1348 static void send_packet(Ssh ssh
, int pkttype
, ...)
1351 va_start(ap1
, pkttype
);
1352 va_start(ap2
, pkttype
);
1353 construct_packet(ssh
, pkttype
, ap1
, ap2
);
1357 static void defer_packet(Ssh ssh
, int pkttype
, ...)
1360 va_start(ap1
, pkttype
);
1361 va_start(ap2
, pkttype
);
1362 construct_packet(ssh
, pkttype
, ap1
, ap2
);
1366 static int ssh_versioncmp(char *a
, char *b
)
1369 unsigned long av
, bv
;
1371 av
= strtoul(a
, &ae
, 10);
1372 bv
= strtoul(b
, &be
, 10);
1374 return (av
< bv ?
-1 : +1);
1379 av
= strtoul(ae
, &ae
, 10);
1380 bv
= strtoul(be
, &be
, 10);
1382 return (av
< bv ?
-1 : +1);
1387 * Utility routines for putting an SSH-protocol `string' and
1388 * `uint32' into a SHA state.
1391 static void sha_string(SHA_State
* s
, void *str
, int len
)
1393 unsigned char lenblk
[4];
1394 PUT_32BIT(lenblk
, len
);
1395 SHA_Bytes(s
, lenblk
, 4);
1396 SHA_Bytes(s
, str
, len
);
1399 static void sha_uint32(SHA_State
* s
, unsigned i
)
1401 unsigned char intblk
[4];
1402 PUT_32BIT(intblk
, i
);
1403 SHA_Bytes(s
, intblk
, 4);
1407 * SSH2 packet construction functions.
1409 static void ssh2_pkt_ensure(Ssh ssh
, int length
)
1411 if (ssh
->pktout
.maxlen
< length
) {
1412 ssh
->pktout
.maxlen
= length
+ 256;
1413 ssh
->pktout
.data
= sresize(ssh
->pktout
.data
,
1414 ssh
->pktout
.maxlen
+ APIEXTRA
,
1416 if (!ssh
->pktout
.data
)
1417 fatalbox("Out of memory");
1420 static void ssh2_pkt_adddata(Ssh ssh
, void *data
, int len
)
1422 ssh
->pktout
.length
+= len
;
1423 ssh2_pkt_ensure(ssh
, ssh
->pktout
.length
);
1424 memcpy(ssh
->pktout
.data
+ ssh
->pktout
.length
- len
, data
, len
);
1426 static void ssh2_pkt_addbyte(Ssh ssh
, unsigned char byte
)
1428 ssh2_pkt_adddata(ssh
, &byte
, 1);
1430 static void ssh2_pkt_init(Ssh ssh
, int pkt_type
)
1432 ssh
->pktout
.length
= 5;
1433 ssh2_pkt_addbyte(ssh
, (unsigned char) pkt_type
);
1435 static void ssh2_pkt_addbool(Ssh ssh
, unsigned char value
)
1437 ssh2_pkt_adddata(ssh
, &value
, 1);
1439 static void ssh2_pkt_adduint32(Ssh ssh
, unsigned long value
)
1442 PUT_32BIT(x
, value
);
1443 ssh2_pkt_adddata(ssh
, x
, 4);
1445 static void ssh2_pkt_addstring_start(Ssh ssh
)
1447 ssh2_pkt_adduint32(ssh
, 0);
1448 ssh
->pktout
.savedpos
= ssh
->pktout
.length
;
1450 static void ssh2_pkt_addstring_str(Ssh ssh
, char *data
)
1452 ssh2_pkt_adddata(ssh
, data
, strlen(data
));
1453 PUT_32BIT(ssh
->pktout
.data
+ ssh
->pktout
.savedpos
- 4,
1454 ssh
->pktout
.length
- ssh
->pktout
.savedpos
);
1456 static void ssh2_pkt_addstring_data(Ssh ssh
, char *data
, int len
)
1458 ssh2_pkt_adddata(ssh
, data
, len
);
1459 PUT_32BIT(ssh
->pktout
.data
+ ssh
->pktout
.savedpos
- 4,
1460 ssh
->pktout
.length
- ssh
->pktout
.savedpos
);
1462 static void ssh2_pkt_addstring(Ssh ssh
, char *data
)
1464 ssh2_pkt_addstring_start(ssh
);
1465 ssh2_pkt_addstring_str(ssh
, data
);
1467 static unsigned char *ssh2_mpint_fmt(Bignum b
, int *len
)
1470 int i
, n
= (bignum_bitcount(b
) + 7) / 8;
1471 p
= snewn(n
+ 1, unsigned char);
1473 fatalbox("out of memory");
1475 for (i
= 1; i
<= n
; i
++)
1476 p
[i
] = bignum_byte(b
, n
- i
);
1478 while (i
<= n
&& p
[i
] == 0 && (p
[i
+ 1] & 0x80) == 0)
1480 memmove(p
, p
+ i
, n
+ 1 - i
);
1484 static void ssh2_pkt_addmp(Ssh ssh
, Bignum b
)
1488 p
= ssh2_mpint_fmt(b
, &len
);
1489 ssh2_pkt_addstring_start(ssh
);
1490 ssh2_pkt_addstring_data(ssh
, (char *)p
, len
);
1495 * Construct an SSH2 final-form packet: compress it, encrypt it,
1496 * put the MAC on it. Final packet, ready to be sent, is stored in
1497 * ssh->pktout.data. Total length is returned.
1499 static int ssh2_pkt_construct(Ssh ssh
)
1501 int cipherblk
, maclen
, padding
, i
;
1504 log_packet(ssh
->logctx
, PKT_OUTGOING
, ssh
->pktout
.data
[5],
1505 ssh2_pkt_type(ssh
->pkt_ctx
, ssh
->pktout
.data
[5]),
1506 ssh
->pktout
.data
+ 6, ssh
->pktout
.length
- 6);
1509 * Compress packet payload.
1512 unsigned char *newpayload
;
1515 ssh
->cscomp
->compress(ssh
->cs_comp_ctx
, ssh
->pktout
.data
+ 5,
1516 ssh
->pktout
.length
- 5,
1517 &newpayload
, &newlen
)) {
1518 ssh
->pktout
.length
= 5;
1519 ssh2_pkt_adddata(ssh
, newpayload
, newlen
);
1525 * Add padding. At least four bytes, and must also bring total
1526 * length (minus MAC) up to a multiple of the block size.
1528 cipherblk
= ssh
->cscipher ? ssh
->cscipher
->blksize
: 8; /* block size */
1529 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
1532 (cipherblk
- (ssh
->pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
1533 maclen
= ssh
->csmac ? ssh
->csmac
->len
: 0;
1534 ssh2_pkt_ensure(ssh
, ssh
->pktout
.length
+ padding
+ maclen
);
1535 ssh
->pktout
.data
[4] = padding
;
1536 for (i
= 0; i
< padding
; i
++)
1537 ssh
->pktout
.data
[ssh
->pktout
.length
+ i
] = random_byte();
1538 PUT_32BIT(ssh
->pktout
.data
, ssh
->pktout
.length
+ padding
- 4);
1540 ssh
->csmac
->generate(ssh
->cs_mac_ctx
, ssh
->pktout
.data
,
1541 ssh
->pktout
.length
+ padding
,
1542 ssh
->v2_outgoing_sequence
);
1543 ssh
->v2_outgoing_sequence
++; /* whether or not we MACed */
1546 ssh
->cscipher
->encrypt(ssh
->cs_cipher_ctx
,
1547 ssh
->pktout
.data
, ssh
->pktout
.length
+ padding
);
1549 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1550 return ssh
->pktout
.length
+ padding
+ maclen
;
1554 * Construct and send an SSH2 packet immediately.
1556 static void ssh2_pkt_send(Ssh ssh
)
1560 len
= ssh2_pkt_construct(ssh
);
1561 backlog
= sk_write(ssh
->s
, (char *)ssh
->pktout
.data
, len
);
1562 if (backlog
> SSH_MAX_BACKLOG
)
1563 ssh_throttle_all(ssh
, 1, backlog
);
1567 * Construct an SSH2 packet and add it to a deferred data block.
1568 * Useful for sending multiple packets in a single sk_write() call,
1569 * to prevent a traffic-analysing listener from being able to work
1570 * out the length of any particular packet (such as the password
1573 * Note that because SSH2 sequence-numbers its packets, this can
1574 * NOT be used as an m4-style `defer' allowing packets to be
1575 * constructed in one order and sent in another.
1577 static void ssh2_pkt_defer(Ssh ssh
)
1579 int len
= ssh2_pkt_construct(ssh
);
1580 if (ssh
->deferred_len
+ len
> ssh
->deferred_size
) {
1581 ssh
->deferred_size
= ssh
->deferred_len
+ len
+ 128;
1582 ssh
->deferred_send_data
= sresize(ssh
->deferred_send_data
,
1586 memcpy(ssh
->deferred_send_data
+ ssh
->deferred_len
, ssh
->pktout
.data
, len
);
1587 ssh
->deferred_len
+= len
;
1591 * Send the whole deferred data block constructed by
1592 * ssh2_pkt_defer() or SSH1's defer_packet().
1594 static void ssh_pkt_defersend(Ssh ssh
)
1597 backlog
= sk_write(ssh
->s
, (char *)ssh
->deferred_send_data
,
1599 ssh
->deferred_len
= ssh
->deferred_size
= 0;
1600 sfree(ssh
->deferred_send_data
);
1601 ssh
->deferred_send_data
= NULL
;
1602 if (backlog
> SSH_MAX_BACKLOG
)
1603 ssh_throttle_all(ssh
, 1, backlog
);
1607 void bndebug(char *string
, Bignum b
)
1611 p
= ssh2_mpint_fmt(b
, &len
);
1612 debug(("%s", string
));
1613 for (i
= 0; i
< len
; i
++)
1614 debug((" %02x", p
[i
]));
1620 static void sha_mpint(SHA_State
* s
, Bignum b
)
1624 p
= ssh2_mpint_fmt(b
, &len
);
1625 sha_string(s
, p
, len
);
1630 * SSH2 packet decode functions.
1632 static unsigned long ssh2_pkt_getuint32(Ssh ssh
)
1634 unsigned long value
;
1635 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< 4)
1636 return 0; /* arrgh, no way to decline (FIXME?) */
1637 value
= GET_32BIT(ssh
->pktin
.data
+ ssh
->pktin
.savedpos
);
1638 ssh
->pktin
.savedpos
+= 4;
1641 static int ssh2_pkt_getbool(Ssh ssh
)
1643 unsigned long value
;
1644 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< 1)
1645 return 0; /* arrgh, no way to decline (FIXME?) */
1646 value
= ssh
->pktin
.data
[ssh
->pktin
.savedpos
] != 0;
1647 ssh
->pktin
.savedpos
++;
1650 static void ssh2_pkt_getstring(Ssh ssh
, char **p
, int *length
)
1655 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< 4)
1657 len
= GET_32BIT(ssh
->pktin
.data
+ ssh
->pktin
.savedpos
);
1661 ssh
->pktin
.savedpos
+= 4;
1662 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< *length
)
1664 *p
= (char *)(ssh
->pktin
.data
+ ssh
->pktin
.savedpos
);
1665 ssh
->pktin
.savedpos
+= *length
;
1667 static Bignum
ssh2_pkt_getmp(Ssh ssh
)
1673 ssh2_pkt_getstring(ssh
, &p
, &length
);
1677 bombout(("internal error: Can't handle negative mpints"));
1680 b
= bignum_from_bytes((unsigned char *)p
, length
);
1685 * Helper function to add an SSH2 signature blob to a packet.
1686 * Expects to be shown the public key blob as well as the signature
1687 * blob. Normally works just like ssh2_pkt_addstring, but will
1688 * fiddle with the signature packet if necessary for
1689 * BUG_SSH2_RSA_PADDING.
1691 static void ssh2_add_sigblob(Ssh ssh
, void *pkblob_v
, int pkblob_len
,
1692 void *sigblob_v
, int sigblob_len
)
1694 unsigned char *pkblob
= (unsigned char *)pkblob_v
;
1695 unsigned char *sigblob
= (unsigned char *)sigblob_v
;
1697 /* dmemdump(pkblob, pkblob_len); */
1698 /* dmemdump(sigblob, sigblob_len); */
1701 * See if this is in fact an ssh-rsa signature and a buggy
1702 * server; otherwise we can just do this the easy way.
1704 if ((ssh
->remote_bugs
& BUG_SSH2_RSA_PADDING
) &&
1705 (GET_32BIT(pkblob
) == 7 && !memcmp(pkblob
+4, "ssh-rsa", 7))) {
1706 int pos
, len
, siglen
;
1709 * Find the byte length of the modulus.
1712 pos
= 4+7; /* skip over "ssh-rsa" */
1713 pos
+= 4 + GET_32BIT(pkblob
+pos
); /* skip over exponent */
1714 len
= GET_32BIT(pkblob
+pos
); /* find length of modulus */
1715 pos
+= 4; /* find modulus itself */
1716 while (len
> 0 && pkblob
[pos
] == 0)
1718 /* debug(("modulus length is %d\n", len)); */
1721 * Now find the signature integer.
1723 pos
= 4+7; /* skip over "ssh-rsa" */
1724 siglen
= GET_32BIT(sigblob
+pos
);
1725 /* debug(("signature length is %d\n", siglen)); */
1727 if (len
!= siglen
) {
1728 unsigned char newlen
[4];
1729 ssh2_pkt_addstring_start(ssh
);
1730 ssh2_pkt_addstring_data(ssh
, (char *)sigblob
, pos
);
1731 /* dmemdump(sigblob, pos); */
1732 pos
+= 4; /* point to start of actual sig */
1733 PUT_32BIT(newlen
, len
);
1734 ssh2_pkt_addstring_data(ssh
, (char *)newlen
, 4);
1735 /* dmemdump(newlen, 4); */
1737 while (len
-- > siglen
) {
1738 ssh2_pkt_addstring_data(ssh
, (char *)newlen
, 1);
1739 /* dmemdump(newlen, 1); */
1741 ssh2_pkt_addstring_data(ssh
, (char *)(sigblob
+pos
), siglen
);
1742 /* dmemdump(sigblob+pos, siglen); */
1746 /* Otherwise fall through and do it the easy way. */
1749 ssh2_pkt_addstring_start(ssh
);
1750 ssh2_pkt_addstring_data(ssh
, (char *)sigblob
, sigblob_len
);
1754 * Examine the remote side's version string and compare it against
1755 * a list of known buggy implementations.
1757 static void ssh_detect_bugs(Ssh ssh
, char *vstring
)
1759 char *imp
; /* pointer to implementation part */
1761 imp
+= strcspn(imp
, "-");
1763 imp
+= strcspn(imp
, "-");
1766 ssh
->remote_bugs
= 0;
1768 if (ssh
->cfg
.sshbug_ignore1
== FORCE_ON
||
1769 (ssh
->cfg
.sshbug_ignore1
== AUTO
&&
1770 (!strcmp(imp
, "1.2.18") || !strcmp(imp
, "1.2.19") ||
1771 !strcmp(imp
, "1.2.20") || !strcmp(imp
, "1.2.21") ||
1772 !strcmp(imp
, "1.2.22") || !strcmp(imp
, "Cisco-1.25")))) {
1774 * These versions don't support SSH1_MSG_IGNORE, so we have
1775 * to use a different defence against password length
1778 ssh
->remote_bugs
|= BUG_CHOKES_ON_SSH1_IGNORE
;
1779 logevent("We believe remote version has SSH1 ignore bug");
1782 if (ssh
->cfg
.sshbug_plainpw1
== FORCE_ON
||
1783 (ssh
->cfg
.sshbug_plainpw1
== AUTO
&&
1784 (!strcmp(imp
, "Cisco-1.25")))) {
1786 * These versions need a plain password sent; they can't
1787 * handle having a null and a random length of data after
1790 ssh
->remote_bugs
|= BUG_NEEDS_SSH1_PLAIN_PASSWORD
;
1791 logevent("We believe remote version needs a plain SSH1 password");
1794 if (ssh
->cfg
.sshbug_rsa1
== FORCE_ON
||
1795 (ssh
->cfg
.sshbug_rsa1
== AUTO
&&
1796 (!strcmp(imp
, "Cisco-1.25")))) {
1798 * These versions apparently have no clue whatever about
1799 * RSA authentication and will panic and die if they see
1800 * an AUTH_RSA message.
1802 ssh
->remote_bugs
|= BUG_CHOKES_ON_RSA
;
1803 logevent("We believe remote version can't handle RSA authentication");
1806 if (ssh
->cfg
.sshbug_hmac2
== FORCE_ON
||
1807 (ssh
->cfg
.sshbug_hmac2
== AUTO
&&
1808 (wc_match("2.1.0*", imp
) || wc_match("2.0.*", imp
) ||
1809 wc_match("2.2.0*", imp
) || wc_match("2.3.0*", imp
) ||
1810 wc_match("2.1 *", imp
)))) {
1812 * These versions have the HMAC bug.
1814 ssh
->remote_bugs
|= BUG_SSH2_HMAC
;
1815 logevent("We believe remote version has SSH2 HMAC bug");
1818 if (ssh
->cfg
.sshbug_derivekey2
== FORCE_ON
||
1819 (ssh
->cfg
.sshbug_derivekey2
== AUTO
&&
1820 (wc_match("2.0.0*", imp
) || wc_match("2.0.10*", imp
) ))) {
1822 * These versions have the key-derivation bug (failing to
1823 * include the literal shared secret in the hashes that
1824 * generate the keys).
1826 ssh
->remote_bugs
|= BUG_SSH2_DERIVEKEY
;
1827 logevent("We believe remote version has SSH2 key-derivation bug");
1830 if (ssh
->cfg
.sshbug_rsapad2
== FORCE_ON
||
1831 (ssh
->cfg
.sshbug_rsapad2
== AUTO
&&
1832 (wc_match("OpenSSH_2.[5-9]*", imp
) ||
1833 wc_match("OpenSSH_3.[0-2]*", imp
)))) {
1835 * These versions have the SSH2 RSA padding bug.
1837 ssh
->remote_bugs
|= BUG_SSH2_RSA_PADDING
;
1838 logevent("We believe remote version has SSH2 RSA padding bug");
1841 if (ssh
->cfg
.sshbug_pksessid2
== FORCE_ON
||
1842 (ssh
->cfg
.sshbug_pksessid2
== AUTO
&&
1843 wc_match("OpenSSH_2.[0-2]*", imp
))) {
1845 * These versions have the SSH2 session-ID bug in
1846 * public-key authentication.
1848 ssh
->remote_bugs
|= BUG_SSH2_PK_SESSIONID
;
1849 logevent("We believe remote version has SSH2 public-key-session-ID bug");
1852 if (ssh
->cfg
.sshbug_dhgex2
== FORCE_ON
) {
1854 * User specified the SSH2 DH GEX bug.
1856 ssh
->remote_bugs
|= BUG_SSH2_DH_GEX
;
1857 logevent("We believe remote version has SSH2 DH group exchange bug");
1861 static int do_ssh_init(Ssh ssh
, unsigned char c
)
1863 struct do_ssh_init_state
{
1871 crState(do_ssh_init_state
);
1873 crBegin(ssh
->do_ssh_init_crstate
);
1875 /* Search for the string "SSH-" in the input. */
1878 static const int transS
[] = { 1, 2, 2, 1 };
1879 static const int transH
[] = { 0, 0, 3, 0 };
1880 static const int transminus
[] = { 0, 0, 0, -1 };
1882 s
->i
= transS
[s
->i
];
1884 s
->i
= transH
[s
->i
];
1886 s
->i
= transminus
[s
->i
];
1891 crReturn(1); /* get another character */
1895 s
->vstring
= snewn(s
->vstrsize
, char);
1896 strcpy(s
->vstring
, "SSH-");
1900 crReturn(1); /* get another char */
1901 if (s
->vslen
>= s
->vstrsize
- 1) {
1903 s
->vstring
= sresize(s
->vstring
, s
->vstrsize
, char);
1905 s
->vstring
[s
->vslen
++] = c
;
1908 s
->version
[s
->i
] = '\0';
1910 } else if (s
->i
< sizeof(s
->version
) - 1)
1911 s
->version
[s
->i
++] = c
;
1912 } else if (c
== '\012')
1916 ssh
->agentfwd_enabled
= FALSE
;
1917 ssh
->rdpkt2_state
.incoming_sequence
= 0;
1919 s
->vstring
[s
->vslen
] = 0;
1920 s
->vstring
[strcspn(s
->vstring
, "\r\n")] = '\0';/* remove EOL chars */
1923 vlog
= snewn(20 + s
->vslen
, char);
1924 sprintf(vlog
, "Server version: %s", s
->vstring
);
1928 ssh_detect_bugs(ssh
, s
->vstring
);
1931 * Decide which SSH protocol version to support.
1934 /* Anything strictly below "2.0" means protocol 1 is supported. */
1935 s
->proto1
= ssh_versioncmp(s
->version
, "2.0") < 0;
1936 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
1937 s
->proto2
= ssh_versioncmp(s
->version
, "1.99") >= 0;
1939 if (ssh
->cfg
.sshprot
== 0 && !s
->proto1
) {
1940 bombout(("SSH protocol version 1 required by user but not provided by server"));
1943 if (ssh
->cfg
.sshprot
== 3 && !s
->proto2
) {
1944 bombout(("SSH protocol version 2 required by user but not provided by server"));
1948 if (s
->proto2
&& (ssh
->cfg
.sshprot
>= 2 || !s
->proto1
)) {
1952 char verstring
[80], vlog
[100];
1953 sprintf(verstring
, "SSH-2.0-%s", sshver
);
1954 SHA_Init(&ssh
->exhashbase
);
1956 * Hash our version string and their version string.
1958 sha_string(&ssh
->exhashbase
, verstring
, strlen(verstring
));
1959 sha_string(&ssh
->exhashbase
, s
->vstring
, strcspn(s
->vstring
, "\r\n"));
1960 sprintf(vlog
, "We claim version: %s", verstring
);
1962 strcat(verstring
, "\012");
1963 logevent("Using SSH protocol version 2");
1964 sk_write(ssh
->s
, verstring
, strlen(verstring
));
1965 ssh
->protocol
= ssh2_protocol
;
1967 ssh
->s_rdpkt
= ssh2_rdpkt
;
1972 char verstring
[80], vlog
[100];
1973 sprintf(verstring
, "SSH-%s-%s",
1974 (ssh_versioncmp(s
->version
, "1.5") <= 0 ? s
->version
: "1.5"),
1976 sprintf(vlog
, "We claim version: %s", verstring
);
1978 strcat(verstring
, "\012");
1980 logevent("Using SSH protocol version 1");
1981 sk_write(ssh
->s
, verstring
, strlen(verstring
));
1982 ssh
->protocol
= ssh1_protocol
;
1984 ssh
->s_rdpkt
= ssh1_rdpkt
;
1986 update_specials_menu(ssh
->frontend
);
1987 ssh
->state
= SSH_STATE_BEFORE_SIZE
;
1994 static void ssh_gotdata(Ssh ssh
, unsigned char *data
, int datalen
)
1996 crBegin(ssh
->ssh_gotdata_crstate
);
1999 * To begin with, feed the characters one by one to the
2000 * protocol initialisation / selection function do_ssh_init().
2001 * When that returns 0, we're done with the initial greeting
2002 * exchange and can move on to packet discipline.
2005 int ret
; /* need not be kept across crReturn */
2007 crReturnV
; /* more data please */
2008 ret
= do_ssh_init(ssh
, *data
);
2016 * We emerge from that loop when the initial negotiation is
2017 * over and we have selected an s_rdpkt function. Now pass
2018 * everything to s_rdpkt, and then pass the resulting packets
2019 * to the proper protocol handler.
2024 while (datalen
> 0) {
2025 if (ssh
->s_rdpkt(ssh
, &data
, &datalen
) == 0) {
2026 if (ssh
->state
== SSH_STATE_CLOSED
) {
2029 ssh
->protocol(ssh
, NULL
, 0, 1);
2030 if (ssh
->state
== SSH_STATE_CLOSED
) {
2040 static int ssh_closing(Plug plug
, char *error_msg
, int error_code
,
2043 Ssh ssh
= (Ssh
) plug
;
2044 ssh
->state
= SSH_STATE_CLOSED
;
2050 /* A socket error has occurred. */
2051 logevent(error_msg
);
2052 connection_fatal(ssh
->frontend
, error_msg
);
2054 /* Otherwise, the remote side closed the connection normally. */
2059 static int ssh_receive(Plug plug
, int urgent
, char *data
, int len
)
2061 Ssh ssh
= (Ssh
) plug
;
2062 ssh_gotdata(ssh
, (unsigned char *)data
, len
);
2063 if (ssh
->state
== SSH_STATE_CLOSED
) {
2073 static void ssh_sent(Plug plug
, int bufsize
)
2075 Ssh ssh
= (Ssh
) plug
;
2077 * If the send backlog on the SSH socket itself clears, we
2078 * should unthrottle the whole world if it was throttled.
2080 if (bufsize
< SSH_MAX_BACKLOG
)
2081 ssh_throttle_all(ssh
, 0, bufsize
);
2085 * Connect to specified host and port.
2086 * Returns an error message, or NULL on success.
2087 * Also places the canonical host name into `realhost'. It must be
2088 * freed by the caller.
2090 static char *connect_to_host(Ssh ssh
, char *host
, int port
,
2091 char **realhost
, int nodelay
)
2093 static const struct plug_function_table fn_table
= {
2103 ssh
->savedhost
= snewn(1 + strlen(host
), char);
2104 if (!ssh
->savedhost
)
2105 fatalbox("Out of memory");
2106 strcpy(ssh
->savedhost
, host
);
2109 port
= 22; /* default ssh port */
2110 ssh
->savedport
= port
;
2115 logeventf(ssh
, "Looking up host \"%s\"", host
);
2116 addr
= name_lookup(host
, port
, realhost
, &ssh
->cfg
);
2117 if ((err
= sk_addr_error(addr
)) != NULL
)
2125 sk_getaddr(addr
, addrbuf
, 100);
2126 logeventf(ssh
, "Connecting to %s port %d", addrbuf
, port
);
2128 ssh
->fn
= &fn_table
;
2129 ssh
->s
= new_connection(addr
, *realhost
, port
,
2130 0, 1, nodelay
, (Plug
) ssh
, &ssh
->cfg
);
2131 if ((err
= sk_socket_error(ssh
->s
)) != NULL
) {
2140 * Throttle or unthrottle the SSH connection.
2142 static void ssh1_throttle(Ssh ssh
, int adjust
)
2144 int old_count
= ssh
->v1_throttle_count
;
2145 ssh
->v1_throttle_count
+= adjust
;
2146 assert(ssh
->v1_throttle_count
>= 0);
2147 if (ssh
->v1_throttle_count
&& !old_count
) {
2148 sk_set_frozen(ssh
->s
, 1);
2149 } else if (!ssh
->v1_throttle_count
&& old_count
) {
2150 sk_set_frozen(ssh
->s
, 0);
2155 * Throttle or unthrottle _all_ local data streams (for when sends
2156 * on the SSH connection itself back up).
2158 static void ssh_throttle_all(Ssh ssh
, int enable
, int bufsize
)
2161 struct ssh_channel
*c
;
2163 if (enable
== ssh
->throttled_all
)
2165 ssh
->throttled_all
= enable
;
2166 ssh
->overall_bufsize
= bufsize
;
2169 for (i
= 0; NULL
!= (c
= index234(ssh
->channels
, i
)); i
++) {
2171 case CHAN_MAINSESSION
:
2173 * This is treated separately, outside the switch.
2177 x11_override_throttle(c
->u
.x11
.s
, enable
);
2180 /* Agent channels require no buffer management. */
2183 pfd_override_throttle(c
->u
.x11
.s
, enable
);
2190 * Username and password input, abstracted off into routines
2191 * reusable in several places - even between SSH1 and SSH2.
2194 /* Set up a username or password input loop on a given buffer. */
2195 static void setup_userpass_input(Ssh ssh
, char *buffer
, int buflen
, int echo
)
2197 ssh
->userpass_input_buffer
= buffer
;
2198 ssh
->userpass_input_buflen
= buflen
;
2199 ssh
->userpass_input_bufpos
= 0;
2200 ssh
->userpass_input_echo
= echo
;
2204 * Process some terminal data in the course of username/password
2205 * input. Returns >0 for success (line of input returned in
2206 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2207 * for inconclusive (keep waiting for more input please).
2209 static int process_userpass_input(Ssh ssh
, unsigned char *in
, int inlen
)
2214 switch (c
= *in
++) {
2217 ssh
->userpass_input_buffer
[ssh
->userpass_input_bufpos
] = 0;
2218 ssh
->userpass_input_buffer
[ssh
->userpass_input_buflen
-1] = 0;
2223 if (ssh
->userpass_input_bufpos
> 0) {
2224 if (ssh
->userpass_input_echo
)
2225 c_write_str(ssh
, "\b \b");
2226 ssh
->userpass_input_bufpos
--;
2231 while (ssh
->userpass_input_bufpos
> 0) {
2232 if (ssh
->userpass_input_echo
)
2233 c_write_str(ssh
, "\b \b");
2234 ssh
->userpass_input_bufpos
--;
2243 * This simplistic check for printability is disabled
2244 * when we're doing password input, because some people
2245 * have control characters in their passwords.o
2247 if ((!ssh
->userpass_input_echo
||
2248 (c
>= ' ' && c
<= '~') ||
2249 ((unsigned char) c
>= 160))
2250 && ssh
->userpass_input_bufpos
< ssh
->userpass_input_buflen
-1) {
2251 ssh
->userpass_input_buffer
[ssh
->userpass_input_bufpos
++] = c
;
2252 if (ssh
->userpass_input_echo
)
2253 c_write(ssh
, &c
, 1);
2262 * Handle the key exchange and user authentication phases.
2264 static int do_ssh1_login(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
2267 unsigned char cookie
[8];
2268 struct RSAKey servkey
, hostkey
;
2269 struct MD5Context md5c
;
2270 struct do_ssh1_login_state
{
2272 unsigned char *rsabuf
, *keystr1
, *keystr2
;
2273 unsigned long supported_ciphers_mask
, supported_auths_mask
;
2274 int tried_publickey
, tried_agent
;
2275 int tis_auth_refused
, ccard_auth_refused
;
2276 unsigned char session_id
[16];
2279 void *publickey_blob
;
2280 int publickey_bloblen
;
2286 unsigned char request
[5], *response
, *p
;
2295 crState(do_ssh1_login_state
);
2297 crBegin(ssh
->do_ssh1_login_crstate
);
2302 if (ssh
->pktin
.type
!= SSH1_SMSG_PUBLIC_KEY
) {
2303 bombout(("Public key packet not received"));
2307 logevent("Received public keys");
2309 memcpy(cookie
, ssh
->pktin
.body
, 8);
2311 i
= makekey(ssh
->pktin
.body
+ 8, &servkey
, &s
->keystr1
, 0);
2312 j
= makekey(ssh
->pktin
.body
+ 8 + i
, &hostkey
, &s
->keystr2
, 0);
2315 * Log the host key fingerprint.
2319 logevent("Host key fingerprint is:");
2320 strcpy(logmsg
, " ");
2321 hostkey
.comment
= NULL
;
2322 rsa_fingerprint(logmsg
+ strlen(logmsg
),
2323 sizeof(logmsg
) - strlen(logmsg
), &hostkey
);
2327 ssh
->v1_remote_protoflags
= GET_32BIT(ssh
->pktin
.body
+ 8 + i
+ j
);
2328 s
->supported_ciphers_mask
= GET_32BIT(ssh
->pktin
.body
+ 12 + i
+ j
);
2329 s
->supported_auths_mask
= GET_32BIT(ssh
->pktin
.body
+ 16 + i
+ j
);
2331 ssh
->v1_local_protoflags
=
2332 ssh
->v1_remote_protoflags
& SSH1_PROTOFLAGS_SUPPORTED
;
2333 ssh
->v1_local_protoflags
|= SSH1_PROTOFLAG_SCREEN_NUMBER
;
2336 MD5Update(&md5c
, s
->keystr2
, hostkey
.bytes
);
2337 MD5Update(&md5c
, s
->keystr1
, servkey
.bytes
);
2338 MD5Update(&md5c
, ssh
->pktin
.body
, 8);
2339 MD5Final(s
->session_id
, &md5c
);
2341 for (i
= 0; i
< 32; i
++)
2342 ssh
->session_key
[i
] = random_byte();
2344 s
->len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
2346 s
->rsabuf
= snewn(s
->len
, unsigned char);
2348 fatalbox("Out of memory");
2351 * Verify the host key.
2355 * First format the key into a string.
2357 int len
= rsastr_len(&hostkey
);
2358 char fingerprint
[100];
2359 char *keystr
= snewn(len
, char);
2361 fatalbox("Out of memory");
2362 rsastr_fmt(keystr
, &hostkey
);
2363 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
2364 verify_ssh_host_key(ssh
->frontend
,
2365 ssh
->savedhost
, ssh
->savedport
, "rsa", keystr
,
2370 for (i
= 0; i
< 32; i
++) {
2371 s
->rsabuf
[i
] = ssh
->session_key
[i
];
2373 s
->rsabuf
[i
] ^= s
->session_id
[i
];
2376 if (hostkey
.bytes
> servkey
.bytes
) {
2377 rsaencrypt(s
->rsabuf
, 32, &servkey
);
2378 rsaencrypt(s
->rsabuf
, servkey
.bytes
, &hostkey
);
2380 rsaencrypt(s
->rsabuf
, 32, &hostkey
);
2381 rsaencrypt(s
->rsabuf
, hostkey
.bytes
, &servkey
);
2384 logevent("Encrypted session key");
2387 int cipher_chosen
= 0, warn
= 0;
2388 char *cipher_string
= NULL
;
2390 for (i
= 0; !cipher_chosen
&& i
< CIPHER_MAX
; i
++) {
2391 int next_cipher
= ssh
->cfg
.ssh_cipherlist
[i
];
2392 if (next_cipher
== CIPHER_WARN
) {
2393 /* If/when we choose a cipher, warn about it */
2395 } else if (next_cipher
== CIPHER_AES
) {
2396 /* XXX Probably don't need to mention this. */
2397 logevent("AES not supported in SSH1, skipping");
2399 switch (next_cipher
) {
2400 case CIPHER_3DES
: s
->cipher_type
= SSH_CIPHER_3DES
;
2401 cipher_string
= "3DES"; break;
2402 case CIPHER_BLOWFISH
: s
->cipher_type
= SSH_CIPHER_BLOWFISH
;
2403 cipher_string
= "Blowfish"; break;
2404 case CIPHER_DES
: s
->cipher_type
= SSH_CIPHER_DES
;
2405 cipher_string
= "single-DES"; break;
2407 if (s
->supported_ciphers_mask
& (1 << s
->cipher_type
))
2411 if (!cipher_chosen
) {
2412 if ((s
->supported_ciphers_mask
& (1 << SSH_CIPHER_3DES
)) == 0)
2413 bombout(("Server violates SSH 1 protocol by not "
2414 "supporting 3DES encryption"));
2416 /* shouldn't happen */
2417 bombout(("No supported ciphers found"));
2421 /* Warn about chosen cipher if necessary. */
2423 askcipher(ssh
->frontend
, cipher_string
, 0);
2426 switch (s
->cipher_type
) {
2427 case SSH_CIPHER_3DES
:
2428 logevent("Using 3DES encryption");
2430 case SSH_CIPHER_DES
:
2431 logevent("Using single-DES encryption");
2433 case SSH_CIPHER_BLOWFISH
:
2434 logevent("Using Blowfish encryption");
2438 send_packet(ssh
, SSH1_CMSG_SESSION_KEY
,
2439 PKT_CHAR
, s
->cipher_type
,
2440 PKT_DATA
, cookie
, 8,
2441 PKT_CHAR
, (s
->len
* 8) >> 8, PKT_CHAR
, (s
->len
* 8) & 0xFF,
2442 PKT_DATA
, s
->rsabuf
, s
->len
,
2443 PKT_INT
, ssh
->v1_local_protoflags
, PKT_END
);
2445 logevent("Trying to enable encryption...");
2449 ssh
->cipher
= (s
->cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
2450 s
->cipher_type
== SSH_CIPHER_DES ?
&ssh_des
:
2452 ssh
->v1_cipher_ctx
= ssh
->cipher
->make_context();
2453 ssh
->cipher
->sesskey(ssh
->v1_cipher_ctx
, ssh
->session_key
);
2454 logeventf(ssh
, "Initialised %s encryption", ssh
->cipher
->text_name
);
2456 ssh
->crcda_ctx
= crcda_make_context();
2457 logevent("Installing CRC compensation attack detector");
2461 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2462 bombout(("Encryption not successfully enabled"));
2466 logevent("Successfully started encryption");
2470 if ((flags
& FLAG_INTERACTIVE
) && !*ssh
->cfg
.username
) {
2471 if (ssh_get_line
&& !ssh_getline_pw_only
) {
2472 if (!ssh_get_line("login as: ",
2473 s
->username
, sizeof(s
->username
), FALSE
)) {
2475 * get_line failed to get a username.
2478 logevent("No username provided. Abandoning session.");
2479 ssh_closing((Plug
)ssh
, NULL
, 0, 0);
2483 int ret
; /* need not be kept over crReturn */
2484 c_write_str(ssh
, "login as: ");
2487 setup_userpass_input(ssh
, s
->username
, sizeof(s
->username
), 1);
2489 crWaitUntil(!ispkt
);
2490 ret
= process_userpass_input(ssh
, in
, inlen
);
2494 c_write_str(ssh
, "\r\n");
2497 strncpy(s
->username
, ssh
->cfg
.username
, sizeof(s
->username
));
2498 s
->username
[sizeof(s
->username
)-1] = '\0';
2501 send_packet(ssh
, SSH1_CMSG_USER
, PKT_STR
, s
->username
, PKT_END
);
2503 char userlog
[22 + sizeof(s
->username
)];
2504 sprintf(userlog
, "Sent username \"%s\"", s
->username
);
2506 if (flags
& FLAG_INTERACTIVE
&&
2507 (!((flags
& FLAG_STDERR
) && (flags
& FLAG_VERBOSE
)))) {
2508 strcat(userlog
, "\r\n");
2509 c_write_str(ssh
, userlog
);
2516 if ((ssh
->remote_bugs
& BUG_CHOKES_ON_RSA
)) {
2517 /* We must not attempt PK auth. Pretend we've already tried it. */
2518 s
->tried_publickey
= s
->tried_agent
= 1;
2520 s
->tried_publickey
= s
->tried_agent
= 0;
2522 s
->tis_auth_refused
= s
->ccard_auth_refused
= 0;
2523 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
2524 if (!filename_is_null(ssh
->cfg
.keyfile
)) {
2525 if (!rsakey_pubblob(&ssh
->cfg
.keyfile
,
2526 &s
->publickey_blob
, &s
->publickey_bloblen
))
2527 s
->publickey_blob
= NULL
;
2529 s
->publickey_blob
= NULL
;
2531 while (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2532 s
->pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
2534 if (agent_exists() && !s
->tried_agent
) {
2536 * Attempt RSA authentication using Pageant.
2542 logevent("Pageant is running. Requesting keys.");
2544 /* Request the keys held by the agent. */
2545 PUT_32BIT(s
->request
, 1);
2546 s
->request
[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES
;
2547 agent_query(s
->request
, 5, &r
, &s
->responselen
);
2548 s
->response
= (unsigned char *) r
;
2549 if (s
->response
&& s
->responselen
>= 5 &&
2550 s
->response
[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER
) {
2551 s
->p
= s
->response
+ 5;
2552 s
->nkeys
= GET_32BIT(s
->p
);
2556 sprintf(buf
, "Pageant has %d SSH1 keys", s
->nkeys
);
2559 for (s
->keyi
= 0; s
->keyi
< s
->nkeys
; s
->keyi
++) {
2562 sprintf(buf
, "Trying Pageant key #%d", s
->keyi
);
2565 if (s
->publickey_blob
&&
2566 !memcmp(s
->p
, s
->publickey_blob
,
2567 s
->publickey_bloblen
)) {
2568 logevent("This key matches configured key file");
2569 s
->tried_publickey
= 1;
2572 s
->p
+= ssh1_read_bignum(s
->p
, &s
->key
.exponent
);
2573 s
->p
+= ssh1_read_bignum(s
->p
, &s
->key
.modulus
);
2574 s
->commentlen
= GET_32BIT(s
->p
);
2576 s
->commentp
= (char *)s
->p
;
2577 s
->p
+= s
->commentlen
;
2578 send_packet(ssh
, SSH1_CMSG_AUTH_RSA
,
2579 PKT_BIGNUM
, s
->key
.modulus
, PKT_END
);
2581 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2582 logevent("Key refused");
2585 logevent("Received RSA challenge");
2586 ssh1_read_bignum(ssh
->pktin
.body
, &s
->challenge
);
2588 char *agentreq
, *q
, *ret
;
2591 len
= 1 + 4; /* message type, bit count */
2592 len
+= ssh1_bignum_length(s
->key
.exponent
);
2593 len
+= ssh1_bignum_length(s
->key
.modulus
);
2594 len
+= ssh1_bignum_length(s
->challenge
);
2595 len
+= 16; /* session id */
2596 len
+= 4; /* response format */
2597 agentreq
= snewn(4 + len
, char);
2598 PUT_32BIT(agentreq
, len
);
2600 *q
++ = SSH1_AGENTC_RSA_CHALLENGE
;
2601 PUT_32BIT(q
, bignum_bitcount(s
->key
.modulus
));
2603 q
+= ssh1_write_bignum(q
, s
->key
.exponent
);
2604 q
+= ssh1_write_bignum(q
, s
->key
.modulus
);
2605 q
+= ssh1_write_bignum(q
, s
->challenge
);
2606 memcpy(q
, s
->session_id
, 16);
2608 PUT_32BIT(q
, 1); /* response format */
2609 agent_query(agentreq
, len
+ 4, &vret
, &retlen
);
2613 if (ret
[4] == SSH1_AGENT_RSA_RESPONSE
) {
2614 logevent("Sending Pageant's response");
2615 send_packet(ssh
, SSH1_CMSG_AUTH_RSA_RESPONSE
,
2616 PKT_DATA
, ret
+ 5, 16,
2620 if (ssh
->pktin
.type
== SSH1_SMSG_SUCCESS
) {
2622 ("Pageant's response accepted");
2623 if (flags
& FLAG_VERBOSE
) {
2624 c_write_str(ssh
, "Authenticated using"
2626 c_write(ssh
, s
->commentp
,
2628 c_write_str(ssh
, "\" from agent\r\n");
2633 ("Pageant's response not accepted");
2636 ("Pageant failed to answer challenge");
2640 logevent("No reply received from Pageant");
2643 freebn(s
->key
.exponent
);
2644 freebn(s
->key
.modulus
);
2645 freebn(s
->challenge
);
2653 if (!filename_is_null(ssh
->cfg
.keyfile
) && !s
->tried_publickey
)
2654 s
->pwpkt_type
= SSH1_CMSG_AUTH_RSA
;
2656 if (ssh
->cfg
.try_tis_auth
&&
2657 (s
->supported_auths_mask
& (1 << SSH1_AUTH_TIS
)) &&
2658 !s
->tis_auth_refused
) {
2659 s
->pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
2660 logevent("Requested TIS authentication");
2661 send_packet(ssh
, SSH1_CMSG_AUTH_TIS
, PKT_END
);
2663 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
2664 logevent("TIS authentication declined");
2665 if (flags
& FLAG_INTERACTIVE
)
2666 c_write_str(ssh
, "TIS authentication refused.\r\n");
2667 s
->tis_auth_refused
= 1;
2670 int challengelen
= GET_32BIT(ssh
->pktin
.body
);
2671 logevent("Received TIS challenge");
2672 if (challengelen
> sizeof(s
->prompt
) - 1)
2673 challengelen
= sizeof(s
->prompt
) - 1;/* prevent overrun */
2674 memcpy(s
->prompt
, ssh
->pktin
.body
+ 4, challengelen
);
2675 /* Prompt heuristic comes from OpenSSH */
2676 strncpy(s
->prompt
+ challengelen
,
2677 memchr(s
->prompt
, '\n', challengelen
) ?
2678 "": "\r\nResponse: ",
2679 (sizeof s
->prompt
) - challengelen
);
2680 s
->prompt
[(sizeof s
->prompt
) - 1] = '\0';
2683 if (ssh
->cfg
.try_tis_auth
&&
2684 (s
->supported_auths_mask
& (1 << SSH1_AUTH_CCARD
)) &&
2685 !s
->ccard_auth_refused
) {
2686 s
->pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
2687 logevent("Requested CryptoCard authentication");
2688 send_packet(ssh
, SSH1_CMSG_AUTH_CCARD
, PKT_END
);
2690 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
2691 logevent("CryptoCard authentication declined");
2692 c_write_str(ssh
, "CryptoCard authentication refused.\r\n");
2693 s
->ccard_auth_refused
= 1;
2696 int challengelen
= GET_32BIT(ssh
->pktin
.body
);
2697 logevent("Received CryptoCard challenge");
2698 if (challengelen
> sizeof(s
->prompt
) - 1)
2699 challengelen
= sizeof(s
->prompt
) - 1;/* prevent overrun */
2700 memcpy(s
->prompt
, ssh
->pktin
.body
+ 4, challengelen
);
2701 strncpy(s
->prompt
+ challengelen
,
2702 memchr(s
->prompt
, '\n', challengelen
) ?
2703 "" : "\r\nResponse: ",
2704 sizeof(s
->prompt
) - challengelen
);
2705 s
->prompt
[sizeof(s
->prompt
) - 1] = '\0';
2708 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2709 sprintf(s
->prompt
, "%.90s@%.90s's password: ",
2710 s
->username
, ssh
->savedhost
);
2712 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2713 char *comment
= NULL
;
2716 if (flags
& FLAG_VERBOSE
)
2717 c_write_str(ssh
, "Trying public key authentication.\r\n");
2718 logeventf(ssh
, "Trying public key \"%s\"",
2719 filename_to_str(&ssh
->cfg
.keyfile
));
2720 type
= key_type(&ssh
->cfg
.keyfile
);
2721 if (type
!= SSH_KEYTYPE_SSH1
) {
2722 sprintf(msgbuf
, "Key is of wrong type (%s)",
2723 key_type_to_str(type
));
2725 c_write_str(ssh
, msgbuf
);
2726 c_write_str(ssh
, "\r\n");
2727 s
->tried_publickey
= 1;
2730 if (!rsakey_encrypted(&ssh
->cfg
.keyfile
, &comment
)) {
2731 if (flags
& FLAG_VERBOSE
)
2732 c_write_str(ssh
, "No passphrase required.\r\n");
2735 sprintf(s
->prompt
, "Passphrase for key \"%.100s\": ", comment
);
2740 * Show password prompt, having first obtained it via a TIS
2741 * or CryptoCard exchange if we're doing TIS or CryptoCard
2745 if (!ssh_get_line(s
->prompt
, s
->password
,
2746 sizeof(s
->password
), TRUE
)) {
2748 * get_line failed to get a password (for example
2749 * because one was supplied on the command line
2750 * which has already failed to work). Terminate.
2752 send_packet(ssh
, SSH1_MSG_DISCONNECT
,
2753 PKT_STR
, "No more passwords available to try",
2755 logevent("Unable to authenticate");
2756 connection_fatal(ssh
->frontend
, "Unable to authenticate");
2757 ssh_closing((Plug
)ssh
, NULL
, 0, 0);
2761 /* Prompt may have come from server. We've munged it a bit, so
2762 * we know it to be zero-terminated at least once. */
2763 int ret
; /* need not be saved over crReturn */
2764 c_write_untrusted(ssh
, s
->prompt
, strlen(s
->prompt
));
2767 setup_userpass_input(ssh
, s
->password
, sizeof(s
->password
), 0);
2769 crWaitUntil(!ispkt
);
2770 ret
= process_userpass_input(ssh
, in
, inlen
);
2774 c_write_str(ssh
, "\r\n");
2778 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2780 * Try public key authentication with the specified
2783 s
->tried_publickey
= 1;
2786 int ret
= loadrsakey(&ssh
->cfg
.keyfile
, &s
->key
, s
->password
);
2788 c_write_str(ssh
, "Couldn't load private key from ");
2789 c_write_str(ssh
, filename_to_str(&ssh
->cfg
.keyfile
));
2790 c_write_str(ssh
, ".\r\n");
2791 continue; /* go and try password */
2794 c_write_str(ssh
, "Wrong passphrase.\r\n");
2795 s
->tried_publickey
= 0;
2796 continue; /* try again */
2801 * Send a public key attempt.
2803 send_packet(ssh
, SSH1_CMSG_AUTH_RSA
,
2804 PKT_BIGNUM
, s
->key
.modulus
, PKT_END
);
2807 if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2808 c_write_str(ssh
, "Server refused our public key.\r\n");
2809 continue; /* go and try password */
2811 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2812 bombout(("Bizarre response to offer of public key"));
2818 unsigned char buffer
[32];
2819 Bignum challenge
, response
;
2821 ssh1_read_bignum(ssh
->pktin
.body
, &challenge
);
2822 response
= rsadecrypt(challenge
, &s
->key
);
2823 freebn(s
->key
.private_exponent
);/* burn the evidence */
2825 for (i
= 0; i
< 32; i
++) {
2826 buffer
[i
] = bignum_byte(response
, 31 - i
);
2830 MD5Update(&md5c
, buffer
, 32);
2831 MD5Update(&md5c
, s
->session_id
, 16);
2832 MD5Final(buffer
, &md5c
);
2834 send_packet(ssh
, SSH1_CMSG_AUTH_RSA_RESPONSE
,
2835 PKT_DATA
, buffer
, 16, PKT_END
);
2842 if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2843 if (flags
& FLAG_VERBOSE
)
2844 c_write_str(ssh
, "Failed to authenticate with"
2845 " our public key.\r\n");
2846 continue; /* go and try password */
2847 } else if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2848 bombout(("Bizarre response to RSA authentication response"));
2852 break; /* we're through! */
2854 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2856 * Defence against traffic analysis: we send a
2857 * whole bunch of packets containing strings of
2858 * different lengths. One of these strings is the
2859 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2860 * The others are all random data in
2861 * SSH1_MSG_IGNORE packets. This way a passive
2862 * listener can't tell which is the password, and
2863 * hence can't deduce the password length.
2865 * Anybody with a password length greater than 16
2866 * bytes is going to have enough entropy in their
2867 * password that a listener won't find it _that_
2868 * much help to know how long it is. So what we'll
2871 * - if password length < 16, we send 15 packets
2872 * containing string lengths 1 through 15
2874 * - otherwise, we let N be the nearest multiple
2875 * of 8 below the password length, and send 8
2876 * packets containing string lengths N through
2877 * N+7. This won't obscure the order of
2878 * magnitude of the password length, but it will
2879 * introduce a bit of extra uncertainty.
2881 * A few servers (the old 1.2.18 through 1.2.22)
2882 * can't deal with SSH1_MSG_IGNORE. For these
2883 * servers, we need an alternative defence. We make
2884 * use of the fact that the password is interpreted
2885 * as a C string: so we can append a NUL, then some
2888 * One server (a Cisco one) can deal with neither
2889 * SSH1_MSG_IGNORE _nor_ a padded password string.
2890 * For this server we are left with no defences
2891 * against password length sniffing.
2893 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
)) {
2895 * The server can deal with SSH1_MSG_IGNORE, so
2896 * we can use the primary defence.
2898 int bottom
, top
, pwlen
, i
;
2901 pwlen
= strlen(s
->password
);
2903 bottom
= 0; /* zero length passwords are OK! :-) */
2906 bottom
= pwlen
& ~7;
2910 assert(pwlen
>= bottom
&& pwlen
<= top
);
2912 randomstr
= snewn(top
+ 1, char);
2914 for (i
= bottom
; i
<= top
; i
++) {
2916 defer_packet(ssh
, s
->pwpkt_type
,
2917 PKT_STR
, s
->password
, PKT_END
);
2919 for (j
= 0; j
< i
; j
++) {
2921 randomstr
[j
] = random_byte();
2922 } while (randomstr
[j
] == '\0');
2924 randomstr
[i
] = '\0';
2925 defer_packet(ssh
, SSH1_MSG_IGNORE
,
2926 PKT_STR
, randomstr
, PKT_END
);
2929 logevent("Sending password with camouflage packets");
2930 ssh_pkt_defersend(ssh
);
2932 else if (!(ssh
->remote_bugs
& BUG_NEEDS_SSH1_PLAIN_PASSWORD
)) {
2934 * The server can't deal with SSH1_MSG_IGNORE
2935 * but can deal with padded passwords, so we
2936 * can use the secondary defence.
2942 len
= strlen(s
->password
);
2943 if (len
< sizeof(string
)) {
2945 strcpy(string
, s
->password
);
2946 len
++; /* cover the zero byte */
2947 while (len
< sizeof(string
)) {
2948 string
[len
++] = (char) random_byte();
2953 logevent("Sending length-padded password");
2954 send_packet(ssh
, s
->pwpkt_type
, PKT_INT
, len
,
2955 PKT_DATA
, ss
, len
, PKT_END
);
2958 * The server has _both_
2959 * BUG_CHOKES_ON_SSH1_IGNORE and
2960 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2961 * therefore nothing we can do.
2964 len
= strlen(s
->password
);
2965 logevent("Sending unpadded password");
2966 send_packet(ssh
, s
->pwpkt_type
, PKT_INT
, len
,
2967 PKT_DATA
, s
->password
, len
, PKT_END
);
2970 send_packet(ssh
, s
->pwpkt_type
, PKT_STR
, s
->password
, PKT_END
);
2973 logevent("Sent password");
2974 memset(s
->password
, 0, strlen(s
->password
));
2976 if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2977 if (flags
& FLAG_VERBOSE
)
2978 c_write_str(ssh
, "Access denied\r\n");
2979 logevent("Authentication refused");
2980 } else if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2981 bombout(("Strange packet received, type %d", ssh
->pktin
.type
));
2986 logevent("Authentication successful");
2991 void sshfwd_close(struct ssh_channel
*c
)
2995 if (c
&& !c
->closes
) {
2997 * If the channel's remoteid is -1, we have sent
2998 * CHANNEL_OPEN for this channel, but it hasn't even been
2999 * acknowledged by the server. So we must set a close flag
3000 * on it now, and then when the server acks the channel
3001 * open, we can close it then.
3003 if (((int)c
->remoteid
) != -1) {
3004 if (ssh
->version
== 1) {
3005 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
3008 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_CLOSE
);
3009 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
3013 c
->closes
= 1; /* sent MSG_CLOSE */
3014 if (c
->type
== CHAN_X11
) {
3016 logevent("Forwarded X11 connection terminated");
3017 } else if (c
->type
== CHAN_SOCKDATA
||
3018 c
->type
== CHAN_SOCKDATA_DORMANT
) {
3020 logevent("Forwarded port closed");
3025 int sshfwd_write(struct ssh_channel
*c
, char *buf
, int len
)
3029 if (ssh
->version
== 1) {
3030 send_packet(ssh
, SSH1_MSG_CHANNEL_DATA
,
3031 PKT_INT
, c
->remoteid
,
3032 PKT_INT
, len
, PKT_DATA
, buf
, len
, PKT_END
);
3034 * In SSH1 we can return 0 here - implying that forwarded
3035 * connections are never individually throttled - because
3036 * the only circumstance that can cause throttling will be
3037 * the whole SSH connection backing up, in which case
3038 * _everything_ will be throttled as a whole.
3042 ssh2_add_channel_data(c
, buf
, len
);
3043 return ssh2_try_send(c
);
3047 void sshfwd_unthrottle(struct ssh_channel
*c
, int bufsize
)
3051 if (ssh
->version
== 1) {
3052 if (c
->v
.v1
.throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
3053 c
->v
.v1
.throttling
= 0;
3054 ssh1_throttle(ssh
, -1);
3057 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
3061 static void ssh1_protocol(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
3063 crBegin(ssh
->ssh1_protocol_crstate
);
3067 while (!do_ssh1_login(ssh
, in
, inlen
, ispkt
)) {
3070 if (ssh
->state
== SSH_STATE_CLOSED
)
3073 if (ssh
->cfg
.agentfwd
&& agent_exists()) {
3074 logevent("Requesting agent forwarding");
3075 send_packet(ssh
, SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
3079 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3080 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3081 bombout(("Protocol confusion"));
3083 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3084 logevent("Agent forwarding refused");
3086 logevent("Agent forwarding enabled");
3087 ssh
->agentfwd_enabled
= TRUE
;
3091 if (ssh
->cfg
.x11_forward
) {
3092 char proto
[20], data
[64];
3093 logevent("Requesting X11 forwarding");
3094 ssh
->x11auth
= x11_invent_auth(proto
, sizeof(proto
),
3095 data
, sizeof(data
), ssh
->cfg
.x11_auth
);
3096 x11_get_real_auth(ssh
->x11auth
, ssh
->cfg
.x11_display
);
3097 if (ssh
->v1_local_protoflags
& SSH1_PROTOFLAG_SCREEN_NUMBER
) {
3098 send_packet(ssh
, SSH1_CMSG_X11_REQUEST_FORWARDING
,
3099 PKT_STR
, proto
, PKT_STR
, data
,
3100 PKT_INT
, x11_get_screen_number(ssh
->cfg
.x11_display
),
3103 send_packet(ssh
, SSH1_CMSG_X11_REQUEST_FORWARDING
,
3104 PKT_STR
, proto
, PKT_STR
, data
, PKT_END
);
3109 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3110 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3111 bombout(("Protocol confusion"));
3113 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3114 logevent("X11 forwarding refused");
3116 logevent("X11 forwarding enabled");
3117 ssh
->X11_fwd_enabled
= TRUE
;
3124 int sport
,dport
,sserv
,dserv
;
3125 char sports
[256], dports
[256], saddr
[256], host
[256];
3127 ssh
->rportfwds
= newtree234(ssh_rportcmp_ssh1
);
3128 /* Add port forwardings. */
3129 ssh
->portfwd_strptr
= ssh
->cfg
.portfwd
;
3130 while (*ssh
->portfwd_strptr
) {
3131 type
= *ssh
->portfwd_strptr
++;
3134 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= '\t') {
3135 if (*ssh
->portfwd_strptr
== ':') {
3137 * We've seen a colon in the middle of the
3138 * source port number. This means that
3139 * everything we've seen until now is the
3140 * source _address_, so we'll move it into
3141 * saddr and start sports from the beginning
3144 ssh
->portfwd_strptr
++;
3146 strcpy(saddr
, sports
);
3149 if (n
< 255) sports
[n
++] = *ssh
->portfwd_strptr
++;
3153 if (*ssh
->portfwd_strptr
== '\t')
3154 ssh
->portfwd_strptr
++;
3156 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= ':') {
3157 if (n
< 255) host
[n
++] = *ssh
->portfwd_strptr
++;
3160 if (*ssh
->portfwd_strptr
== ':')
3161 ssh
->portfwd_strptr
++;
3163 while (*ssh
->portfwd_strptr
) {
3164 if (n
< 255) dports
[n
++] = *ssh
->portfwd_strptr
++;
3167 ssh
->portfwd_strptr
++;
3168 dport
= atoi(dports
);
3172 dport
= net_service_lookup(dports
);
3174 logeventf(ssh
, "Service lookup failed for"
3175 " destination port \"%s\"", dports
);
3179 while (*ssh
->portfwd_strptr
) ssh
->portfwd_strptr
++;
3181 sport
= atoi(sports
);
3185 sport
= net_service_lookup(sports
);
3187 logeventf(ssh
, "Service lookup failed for source"
3188 " port \"%s\"", sports
);
3191 if (sport
&& dport
) {
3193 pfd_addforward(host
, dport
, *saddr ? saddr
: NULL
,
3194 sport
, ssh
, &ssh
->cfg
);
3195 logeventf(ssh
, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3196 " forwarding to %s:%.*s%.*s%d%.*s",
3197 (int)(*saddr?
strlen(saddr
):0), *saddr?saddr
:NULL
,
3198 (int)(*saddr?
1:0), ":",
3199 (int)(sserv ?
strlen(sports
) : 0), sports
,
3200 sserv
, "(", sport
, sserv
, ")",
3202 (int)(dserv ?
strlen(dports
) : 0), dports
,
3203 dserv
, "(", dport
, dserv
, ")");
3204 } else if (type
== 'D') {
3205 pfd_addforward(NULL
, -1, *saddr ? saddr
: NULL
,
3206 sport
, ssh
, &ssh
->cfg
);
3207 logeventf(ssh
, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3208 " doing SOCKS dynamic forwarding",
3209 (int)(*saddr?
strlen(saddr
):0), *saddr?saddr
:NULL
,
3210 (int)(*saddr?
1:0), ":",
3211 (int)(sserv ?
strlen(sports
) : 0), sports
,
3212 sserv
, "(", sport
, sserv
, ")");
3214 struct ssh_rportfwd
*pf
;
3215 pf
= snew(struct ssh_rportfwd
);
3216 strcpy(pf
->dhost
, host
);
3220 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
3223 if (add234(ssh
->rportfwds
, pf
) != pf
) {
3225 "Duplicate remote port forwarding to %s:%d",
3229 logeventf(ssh
, "Requesting remote port %.*s%.*s%d%.*s"
3230 " forward to %s:%.*s%.*s%d%.*s",
3231 (int)(sserv ?
strlen(sports
) : 0), sports
,
3232 sserv
, "(", sport
, sserv
, ")",
3234 (int)(dserv ?
strlen(dports
) : 0), dports
,
3235 dserv
, "(", dport
, dserv
, ")");
3236 send_packet(ssh
, SSH1_CMSG_PORT_FORWARD_REQUEST
,
3244 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3245 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3246 bombout(("Protocol confusion"));
3248 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3249 c_write_str(ssh
, "Server refused port"
3252 logevent("Remote port forwarding enabled");
3259 if (!ssh
->cfg
.nopty
) {
3260 send_packet(ssh
, SSH1_CMSG_REQUEST_PTY
,
3261 PKT_STR
, ssh
->cfg
.termtype
,
3262 PKT_INT
, ssh
->term_height
,
3263 PKT_INT
, ssh
->term_width
,
3264 PKT_INT
, 0, PKT_INT
, 0, PKT_CHAR
, 0, PKT_END
);
3265 ssh
->state
= SSH_STATE_INTERMED
;
3269 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3270 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3271 bombout(("Protocol confusion"));
3273 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3274 c_write_str(ssh
, "Server refused to allocate pty\r\n");
3275 ssh
->editing
= ssh
->echoing
= 1;
3277 logevent("Allocated pty");
3279 ssh
->editing
= ssh
->echoing
= 1;
3282 if (ssh
->cfg
.compression
) {
3283 send_packet(ssh
, SSH1_CMSG_REQUEST_COMPRESSION
, PKT_INT
, 6, PKT_END
);
3287 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3288 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3289 bombout(("Protocol confusion"));
3291 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3292 c_write_str(ssh
, "Server refused to compress\r\n");
3294 logevent("Started compression");
3295 ssh
->v1_compressing
= TRUE
;
3296 ssh
->cs_comp_ctx
= zlib_compress_init();
3297 logevent("Initialised zlib (RFC1950) compression");
3298 ssh
->sc_comp_ctx
= zlib_decompress_init();
3299 logevent("Initialised zlib (RFC1950) decompression");
3303 * Start the shell or command.
3305 * Special case: if the first-choice command is an SSH2
3306 * subsystem (hence not usable here) and the second choice
3307 * exists, we fall straight back to that.
3310 char *cmd
= ssh
->cfg
.remote_cmd_ptr
;
3312 if (ssh
->cfg
.ssh_subsys
&& ssh
->cfg
.remote_cmd_ptr2
) {
3313 cmd
= ssh
->cfg
.remote_cmd_ptr2
;
3314 ssh
->fallback_cmd
= TRUE
;
3317 send_packet(ssh
, SSH1_CMSG_EXEC_CMD
, PKT_STR
, cmd
, PKT_END
);
3319 send_packet(ssh
, SSH1_CMSG_EXEC_SHELL
, PKT_END
);
3320 logevent("Started session");
3323 ssh
->state
= SSH_STATE_SESSION
;
3324 if (ssh
->size_needed
)
3325 ssh_size(ssh
, ssh
->term_width
, ssh
->term_height
);
3326 if (ssh
->eof_needed
)
3327 ssh_special(ssh
, TS_EOF
);
3330 ldisc_send(ssh
->ldisc
, NULL
, 0, 0);/* cause ldisc to notice changes */
3332 ssh
->channels
= newtree234(ssh_channelcmp
);
3336 if (ssh
->pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
3337 ssh
->pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
3338 long len
= GET_32BIT(ssh
->pktin
.body
);
3340 from_backend(ssh
->frontend
,
3341 ssh
->pktin
.type
== SSH1_SMSG_STDERR_DATA
,
3342 (char *)(ssh
->pktin
.body
) + 4, len
);
3343 if (!ssh
->v1_stdout_throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
3344 ssh
->v1_stdout_throttling
= 1;
3345 ssh1_throttle(ssh
, +1);
3347 } else if (ssh
->pktin
.type
== SSH1_MSG_DISCONNECT
) {
3348 ssh_closing((Plug
)ssh
, NULL
, 0, 0);
3349 logevent("Received disconnect request");
3351 } else if (ssh
->pktin
.type
== SSH1_SMSG_X11_OPEN
) {
3352 /* Remote side is trying to open a channel to talk to our
3353 * X-Server. Give them back a local channel number. */
3354 struct ssh_channel
*c
;
3356 logevent("Received X11 connect request");
3357 /* Refuse if X11 forwarding is disabled. */
3358 if (!ssh
->X11_fwd_enabled
) {
3359 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3360 PKT_INT
, GET_32BIT(ssh
->pktin
.body
), PKT_END
);
3361 logevent("Rejected X11 connect request");
3363 c
= snew(struct ssh_channel
);
3366 if (x11_init(&c
->u
.x11
.s
, ssh
->cfg
.x11_display
, c
,
3367 ssh
->x11auth
, NULL
, -1, &ssh
->cfg
) != NULL
) {
3368 logevent("opening X11 forward connection failed");
3370 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3371 PKT_INT
, GET_32BIT(ssh
->pktin
.body
),
3375 ("opening X11 forward connection succeeded");
3376 c
->remoteid
= GET_32BIT(ssh
->pktin
.body
);
3377 c
->localid
= alloc_channel_id(ssh
);
3379 c
->v
.v1
.throttling
= 0;
3380 c
->type
= CHAN_X11
; /* identify channel type */
3381 add234(ssh
->channels
, c
);
3382 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3383 PKT_INT
, c
->remoteid
, PKT_INT
,
3384 c
->localid
, PKT_END
);
3385 logevent("Opened X11 forward channel");
3388 } else if (ssh
->pktin
.type
== SSH1_SMSG_AGENT_OPEN
) {
3389 /* Remote side is trying to open a channel to talk to our
3390 * agent. Give them back a local channel number. */
3391 struct ssh_channel
*c
;
3393 /* Refuse if agent forwarding is disabled. */
3394 if (!ssh
->agentfwd_enabled
) {
3395 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3396 PKT_INT
, GET_32BIT(ssh
->pktin
.body
), PKT_END
);
3398 c
= snew(struct ssh_channel
);
3400 c
->remoteid
= GET_32BIT(ssh
->pktin
.body
);
3401 c
->localid
= alloc_channel_id(ssh
);
3403 c
->v
.v1
.throttling
= 0;
3404 c
->type
= CHAN_AGENT
; /* identify channel type */
3405 c
->u
.a
.lensofar
= 0;
3406 add234(ssh
->channels
, c
);
3407 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3408 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
3411 } else if (ssh
->pktin
.type
== SSH1_MSG_PORT_OPEN
) {
3412 /* Remote side is trying to open a channel to talk to a
3413 * forwarded port. Give them back a local channel number. */
3414 struct ssh_channel
*c
;
3415 struct ssh_rportfwd pf
;
3417 char host
[256], buf
[1024];
3419 c
= snew(struct ssh_channel
);
3422 hostsize
= GET_32BIT(ssh
->pktin
.body
+4);
3423 for (h
= host
, p
= (char *)(ssh
->pktin
.body
+8);
3424 hostsize
!= 0; hostsize
--) {
3425 if (h
+1 < host
+sizeof(host
))
3430 port
= GET_32BIT(p
);
3432 strcpy(pf
.dhost
, host
);
3435 if (find234(ssh
->rportfwds
, &pf
, NULL
) == NULL
) {
3436 sprintf(buf
, "Rejected remote port open request for %s:%d",
3439 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3440 PKT_INT
, GET_32BIT(ssh
->pktin
.body
), PKT_END
);
3442 sprintf(buf
, "Received remote port open request for %s:%d",
3445 e
= pfd_newconnect(&c
->u
.pfd
.s
, host
, port
, c
, &ssh
->cfg
);
3448 sprintf(buf
, "Port open failed: %s", e
);
3451 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3452 PKT_INT
, GET_32BIT(ssh
->pktin
.body
),
3455 c
->remoteid
= GET_32BIT(ssh
->pktin
.body
);
3456 c
->localid
= alloc_channel_id(ssh
);
3458 c
->v
.v1
.throttling
= 0;
3459 c
->type
= CHAN_SOCKDATA
; /* identify channel type */
3460 add234(ssh
->channels
, c
);
3461 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3462 PKT_INT
, c
->remoteid
, PKT_INT
,
3463 c
->localid
, PKT_END
);
3464 logevent("Forwarded port opened successfully");
3468 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
) {
3469 unsigned int remoteid
= GET_32BIT(ssh
->pktin
.body
);
3470 unsigned int localid
= GET_32BIT(ssh
->pktin
.body
+4);
3471 struct ssh_channel
*c
;
3473 c
= find234(ssh
->channels
, &remoteid
, ssh_channelfind
);
3474 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
3475 c
->remoteid
= localid
;
3476 c
->type
= CHAN_SOCKDATA
;
3477 c
->v
.v1
.throttling
= 0;
3478 pfd_confirm(c
->u
.pfd
.s
);
3481 if (c
&& c
->closes
) {
3483 * We have a pending close on this channel,
3484 * which we decided on before the server acked
3485 * the channel open. So now we know the
3486 * remoteid, we can close it again.
3488 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE
,
3489 PKT_INT
, c
->remoteid
, PKT_END
);
3492 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_OPEN_FAILURE
) {
3493 unsigned int remoteid
= GET_32BIT(ssh
->pktin
.body
);
3494 struct ssh_channel
*c
;
3496 c
= find234(ssh
->channels
, &remoteid
, ssh_channelfind
);
3497 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
3498 logevent("Forwarded connection refused by server");
3499 pfd_close(c
->u
.pfd
.s
);
3500 del234(ssh
->channels
, c
);
3504 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE
||
3505 ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
) {
3506 /* Remote side closes a channel. */
3507 unsigned i
= GET_32BIT(ssh
->pktin
.body
);
3508 struct ssh_channel
*c
;
3509 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
3510 if (c
&& ((int)c
->remoteid
) != -1) {
3513 (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
1 : 2);
3515 if ((c
->closes
== 0) && (c
->type
== CHAN_X11
)) {
3516 logevent("Forwarded X11 connection terminated");
3517 assert(c
->u
.x11
.s
!= NULL
);
3518 x11_close(c
->u
.x11
.s
);
3521 if ((c
->closes
== 0) && (c
->type
== CHAN_SOCKDATA
)) {
3522 logevent("Forwarded port closed");
3523 assert(c
->u
.pfd
.s
!= NULL
);
3524 pfd_close(c
->u
.pfd
.s
);
3528 c
->closes
|= (closetype
<< 2); /* seen this message */
3529 if (!(c
->closes
& closetype
)) {
3530 send_packet(ssh
, ssh
->pktin
.type
, PKT_INT
, c
->remoteid
,
3532 c
->closes
|= closetype
; /* sent it too */
3535 if (c
->closes
== 15) {
3536 del234(ssh
->channels
, c
);
3540 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
3541 ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
"" :
3542 "_CONFIRMATION", c ?
"half-open" : "nonexistent",
3545 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_DATA
) {
3546 /* Data sent down one of our channels. */
3547 int i
= GET_32BIT(ssh
->pktin
.body
);
3548 int len
= GET_32BIT(ssh
->pktin
.body
+ 4);
3549 unsigned char *p
= ssh
->pktin
.body
+ 8;
3550 struct ssh_channel
*c
;
3551 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
3556 bufsize
= x11_send(c
->u
.x11
.s
, (char *)p
, len
);
3559 bufsize
= pfd_send(c
->u
.pfd
.s
, (char *)p
, len
);
3562 /* Data for an agent message. Buffer it. */
3564 if (c
->u
.a
.lensofar
< 4) {
3565 int l
= min(4 - c
->u
.a
.lensofar
, len
);
3566 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
,
3570 c
->u
.a
.lensofar
+= l
;
3572 if (c
->u
.a
.lensofar
== 4) {
3574 4 + GET_32BIT(c
->u
.a
.msglen
);
3575 c
->u
.a
.message
= snewn(c
->u
.a
.totallen
,
3577 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
3579 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
3581 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
3583 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
,
3587 c
->u
.a
.lensofar
+= l
;
3589 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
3590 void *reply
, *sentreply
;
3592 agent_query(c
->u
.a
.message
,
3593 c
->u
.a
.totallen
, &reply
,
3598 /* Fake SSH_AGENT_FAILURE. */
3599 sentreply
= "\0\0\0\1\5";
3602 send_packet(ssh
, SSH1_MSG_CHANNEL_DATA
,
3603 PKT_INT
, c
->remoteid
,
3605 PKT_DATA
, sentreply
, replylen
,
3609 sfree(c
->u
.a
.message
);
3610 c
->u
.a
.lensofar
= 0;
3613 bufsize
= 0; /* agent channels never back up */
3616 if (!c
->v
.v1
.throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
3617 c
->v
.v1
.throttling
= 1;
3618 ssh1_throttle(ssh
, +1);
3621 } else if (ssh
->pktin
.type
== SSH1_SMSG_SUCCESS
) {
3622 /* may be from EXEC_SHELL on some servers */
3623 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3624 /* may be from EXEC_SHELL on some servers
3625 * if no pty is available or in other odd cases. Ignore */
3626 } else if (ssh
->pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
3628 ssh
->exitcode
= GET_32BIT(ssh
->pktin
.body
);
3629 sprintf(buf
, "Server sent command exit status %d",
3632 send_packet(ssh
, SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
3634 * In case `helpful' firewalls or proxies tack
3635 * extra human-readable text on the end of the
3636 * session which we might mistake for another
3637 * encrypted packet, we close the session once
3638 * we've sent EXIT_CONFIRMATION.
3640 ssh_closing((Plug
)ssh
, NULL
, 0, 0);
3643 bombout(("Strange packet received: type %d", ssh
->pktin
.type
));
3648 int len
= min(inlen
, 512);
3649 send_packet(ssh
, SSH1_CMSG_STDIN_DATA
,
3650 PKT_INT
, len
, PKT_DATA
, in
, len
, PKT_END
);
3661 * Utility routine for decoding comma-separated strings in KEXINIT.
3663 static int in_commasep_string(char *needle
, char *haystack
, int haylen
)
3666 if (!needle
|| !haystack
) /* protect against null pointers */
3668 needlen
= strlen(needle
);
3671 * Is it at the start of the string?
3673 if (haylen
>= needlen
&& /* haystack is long enough */
3674 !memcmp(needle
, haystack
, needlen
) && /* initial match */
3675 (haylen
== needlen
|| haystack
[needlen
] == ',')
3676 /* either , or EOS follows */
3680 * If not, search for the next comma and resume after that.
3681 * If no comma found, terminate.
3683 while (haylen
> 0 && *haystack
!= ',')
3684 haylen
--, haystack
++;
3687 haylen
--, haystack
++; /* skip over comma itself */
3692 * SSH2 key creation method.
3694 static void ssh2_mkkey(Ssh ssh
, Bignum K
, unsigned char *H
,
3695 unsigned char *sessid
, char chr
,
3696 unsigned char *keyspace
)
3699 /* First 20 bytes. */
3701 if (!(ssh
->remote_bugs
& BUG_SSH2_DERIVEKEY
))
3703 SHA_Bytes(&s
, H
, 20);
3704 SHA_Bytes(&s
, &chr
, 1);
3705 SHA_Bytes(&s
, sessid
, 20);
3706 SHA_Final(&s
, keyspace
);
3707 /* Next 20 bytes. */
3709 if (!(ssh
->remote_bugs
& BUG_SSH2_DERIVEKEY
))
3711 SHA_Bytes(&s
, H
, 20);
3712 SHA_Bytes(&s
, keyspace
, 20);
3713 SHA_Final(&s
, keyspace
+ 20);
3717 * Handle the SSH2 transport layer.
3719 static int do_ssh2_transport(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
3721 struct do_ssh2_transport_state
{
3722 int nbits
, pbits
, warn
;
3723 Bignum p
, g
, e
, f
, K
;
3724 int kex_init_value
, kex_reply_value
;
3725 const struct ssh_mac
**maclist
;
3727 const struct ssh2_cipher
*cscipher_tobe
;
3728 const struct ssh2_cipher
*sccipher_tobe
;
3729 const struct ssh_mac
*csmac_tobe
;
3730 const struct ssh_mac
*scmac_tobe
;
3731 const struct ssh_compress
*cscomp_tobe
;
3732 const struct ssh_compress
*sccomp_tobe
;
3733 char *hostkeydata
, *sigdata
, *keystr
, *fingerprint
;
3734 int hostkeylen
, siglen
;
3735 void *hkey
; /* actual host key */
3736 unsigned char exchange_hash
[20];
3737 int n_preferred_ciphers
;
3738 const struct ssh2_ciphers
*preferred_ciphers
[CIPHER_MAX
];
3739 const struct ssh_compress
*preferred_comp
;
3742 crState(do_ssh2_transport_state
);
3744 crBegin(ssh
->do_ssh2_transport_crstate
);
3746 s
->cscipher_tobe
= s
->sccipher_tobe
= NULL
;
3747 s
->csmac_tobe
= s
->scmac_tobe
= NULL
;
3748 s
->cscomp_tobe
= s
->sccomp_tobe
= NULL
;
3756 * Set up the preferred ciphers. (NULL => warn below here)
3758 s
->n_preferred_ciphers
= 0;
3759 for (i
= 0; i
< CIPHER_MAX
; i
++) {
3760 switch (ssh
->cfg
.ssh_cipherlist
[i
]) {
3761 case CIPHER_BLOWFISH
:
3762 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_blowfish
;
3765 if (ssh
->cfg
.ssh2_des_cbc
) {
3766 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_des
;
3770 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_3des
;
3773 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_aes
;
3776 /* Flag for later. Don't bother if it's the last in
3778 if (i
< CIPHER_MAX
- 1) {
3779 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = NULL
;
3787 * Set up preferred compression.
3789 if (ssh
->cfg
.compression
)
3790 s
->preferred_comp
= &ssh_zlib
;
3792 s
->preferred_comp
= &ssh_comp_none
;
3795 * Be prepared to work around the buggy MAC problem.
3797 if (ssh
->remote_bugs
& BUG_SSH2_HMAC
)
3798 s
->maclist
= buggymacs
, s
->nmacs
= lenof(buggymacs
);
3800 s
->maclist
= macs
, s
->nmacs
= lenof(macs
);
3804 int i
, j
, cipherstr_started
;
3807 * Construct and send our key exchange packet.
3809 ssh2_pkt_init(ssh
, SSH2_MSG_KEXINIT
);
3810 for (i
= 0; i
< 16; i
++)
3811 ssh2_pkt_addbyte(ssh
, (unsigned char) random_byte());
3812 /* List key exchange algorithms. */
3813 ssh2_pkt_addstring_start(ssh
);
3814 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3815 if (kex_algs
[i
] == &ssh_diffiehellman_gex
&&
3816 (ssh
->remote_bugs
& BUG_SSH2_DH_GEX
))
3818 ssh2_pkt_addstring_str(ssh
, kex_algs
[i
]->name
);
3819 if (i
< lenof(kex_algs
) - 1)
3820 ssh2_pkt_addstring_str(ssh
, ",");
3822 /* List server host key algorithms. */
3823 ssh2_pkt_addstring_start(ssh
);
3824 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3825 ssh2_pkt_addstring_str(ssh
, hostkey_algs
[i
]->name
);
3826 if (i
< lenof(hostkey_algs
) - 1)
3827 ssh2_pkt_addstring_str(ssh
, ",");
3829 /* List client->server encryption algorithms. */
3830 ssh2_pkt_addstring_start(ssh
);
3831 cipherstr_started
= 0;
3832 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
3833 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
3834 if (!c
) continue; /* warning flag */
3835 for (j
= 0; j
< c
->nciphers
; j
++) {
3836 if (cipherstr_started
)
3837 ssh2_pkt_addstring_str(ssh
, ",");
3838 ssh2_pkt_addstring_str(ssh
, c
->list
[j
]->name
);
3839 cipherstr_started
= 1;
3842 /* List server->client encryption algorithms. */
3843 ssh2_pkt_addstring_start(ssh
);
3844 cipherstr_started
= 0;
3845 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
3846 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
3847 if (!c
) continue; /* warning flag */
3848 for (j
= 0; j
< c
->nciphers
; j
++) {
3849 if (cipherstr_started
)
3850 ssh2_pkt_addstring_str(ssh
, ",");
3851 ssh2_pkt_addstring_str(ssh
, c
->list
[j
]->name
);
3852 cipherstr_started
= 1;
3855 /* List client->server MAC algorithms. */
3856 ssh2_pkt_addstring_start(ssh
);
3857 for (i
= 0; i
< s
->nmacs
; i
++) {
3858 ssh2_pkt_addstring_str(ssh
, s
->maclist
[i
]->name
);
3859 if (i
< s
->nmacs
- 1)
3860 ssh2_pkt_addstring_str(ssh
, ",");
3862 /* List server->client MAC algorithms. */
3863 ssh2_pkt_addstring_start(ssh
);
3864 for (i
= 0; i
< s
->nmacs
; i
++) {
3865 ssh2_pkt_addstring_str(ssh
, s
->maclist
[i
]->name
);
3866 if (i
< s
->nmacs
- 1)
3867 ssh2_pkt_addstring_str(ssh
, ",");
3869 /* List client->server compression algorithms. */
3870 ssh2_pkt_addstring_start(ssh
);
3871 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3872 const struct ssh_compress
*c
=
3873 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
3874 ssh2_pkt_addstring_str(ssh
, c
->name
);
3875 if (i
< lenof(compressions
))
3876 ssh2_pkt_addstring_str(ssh
, ",");
3878 /* List server->client compression algorithms. */
3879 ssh2_pkt_addstring_start(ssh
);
3880 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3881 const struct ssh_compress
*c
=
3882 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
3883 ssh2_pkt_addstring_str(ssh
, c
->name
);
3884 if (i
< lenof(compressions
))
3885 ssh2_pkt_addstring_str(ssh
, ",");
3887 /* List client->server languages. Empty list. */
3888 ssh2_pkt_addstring_start(ssh
);
3889 /* List server->client languages. Empty list. */
3890 ssh2_pkt_addstring_start(ssh
);
3891 /* First KEX packet does _not_ follow, because we're not that brave. */
3892 ssh2_pkt_addbool(ssh
, FALSE
);
3894 ssh2_pkt_adduint32(ssh
, 0);
3897 ssh
->exhash
= ssh
->exhashbase
;
3898 sha_string(&ssh
->exhash
, ssh
->pktout
.data
+ 5, ssh
->pktout
.length
- 5);
3904 if (ssh
->pktin
.length
> 5)
3905 sha_string(&ssh
->exhash
, ssh
->pktin
.data
+ 5, ssh
->pktin
.length
- 5);
3908 * Now examine the other side's KEXINIT to see what we're up
3915 if (ssh
->pktin
.type
!= SSH2_MSG_KEXINIT
) {
3916 bombout(("expected key exchange packet from server"));
3920 ssh
->hostkey
= NULL
;
3921 s
->cscipher_tobe
= NULL
;
3922 s
->sccipher_tobe
= NULL
;
3923 s
->csmac_tobe
= NULL
;
3924 s
->scmac_tobe
= NULL
;
3925 s
->cscomp_tobe
= NULL
;
3926 s
->sccomp_tobe
= NULL
;
3927 ssh
->pktin
.savedpos
+= 16; /* skip garbage cookie */
3928 ssh2_pkt_getstring(ssh
, &str
, &len
); /* key exchange algorithms */
3929 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3930 if (kex_algs
[i
] == &ssh_diffiehellman_gex
&&
3931 (ssh
->remote_bugs
& BUG_SSH2_DH_GEX
))
3933 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
3934 ssh
->kex
= kex_algs
[i
];
3938 ssh2_pkt_getstring(ssh
, &str
, &len
); /* host key algorithms */
3939 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3940 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
3941 ssh
->hostkey
= hostkey_algs
[i
];
3945 ssh2_pkt_getstring(ssh
, &str
, &len
); /* client->server cipher */
3947 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
3948 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
3952 for (j
= 0; j
< c
->nciphers
; j
++) {
3953 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3954 s
->cscipher_tobe
= c
->list
[j
];
3959 if (s
->cscipher_tobe
) {
3961 askcipher(ssh
->frontend
, s
->cscipher_tobe
->name
, 1);
3965 if (!s
->cscipher_tobe
) {
3966 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
3967 str ? str
: "(null)"));
3971 ssh2_pkt_getstring(ssh
, &str
, &len
); /* server->client cipher */
3973 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
3974 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
3978 for (j
= 0; j
< c
->nciphers
; j
++) {
3979 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3980 s
->sccipher_tobe
= c
->list
[j
];
3985 if (s
->sccipher_tobe
) {
3987 askcipher(ssh
->frontend
, s
->sccipher_tobe
->name
, 2);
3991 if (!s
->sccipher_tobe
) {
3992 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
3993 str ? str
: "(null)"));
3997 ssh2_pkt_getstring(ssh
, &str
, &len
); /* client->server mac */
3998 for (i
= 0; i
< s
->nmacs
; i
++) {
3999 if (in_commasep_string(s
->maclist
[i
]->name
, str
, len
)) {
4000 s
->csmac_tobe
= s
->maclist
[i
];
4004 ssh2_pkt_getstring(ssh
, &str
, &len
); /* server->client mac */
4005 for (i
= 0; i
< s
->nmacs
; i
++) {
4006 if (in_commasep_string(s
->maclist
[i
]->name
, str
, len
)) {
4007 s
->scmac_tobe
= s
->maclist
[i
];
4011 ssh2_pkt_getstring(ssh
, &str
, &len
); /* client->server compression */
4012 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
4013 const struct ssh_compress
*c
=
4014 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
4015 if (in_commasep_string(c
->name
, str
, len
)) {
4020 ssh2_pkt_getstring(ssh
, &str
, &len
); /* server->client compression */
4021 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
4022 const struct ssh_compress
*c
=
4023 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
4024 if (in_commasep_string(c
->name
, str
, len
)) {
4032 * Work out the number of bits of key we will need from the key
4033 * exchange. We start with the maximum key length of either
4039 csbits
= s
->cscipher_tobe
->keylen
;
4040 scbits
= s
->sccipher_tobe
->keylen
;
4041 s
->nbits
= (csbits
> scbits ? csbits
: scbits
);
4043 /* The keys only have 160-bit entropy, since they're based on
4044 * a SHA-1 hash. So cap the key size at 160 bits. */
4049 * If we're doing Diffie-Hellman group exchange, start by
4050 * requesting a group.
4052 if (ssh
->kex
== &ssh_diffiehellman_gex
) {
4053 logevent("Doing Diffie-Hellman group exchange");
4054 ssh
->pkt_ctx
|= SSH2_PKTCTX_DHGEX
;
4056 * Work out how big a DH group we will need to allow that
4059 s
->pbits
= 512 << ((s
->nbits
- 1) / 64);
4060 ssh2_pkt_init(ssh
, SSH2_MSG_KEX_DH_GEX_REQUEST
);
4061 ssh2_pkt_adduint32(ssh
, s
->pbits
);
4065 if (ssh
->pktin
.type
!= SSH2_MSG_KEX_DH_GEX_GROUP
) {
4066 bombout(("expected key exchange group packet from server"));
4069 s
->p
= ssh2_pkt_getmp(ssh
);
4070 s
->g
= ssh2_pkt_getmp(ssh
);
4071 ssh
->kex_ctx
= dh_setup_group(s
->p
, s
->g
);
4072 s
->kex_init_value
= SSH2_MSG_KEX_DH_GEX_INIT
;
4073 s
->kex_reply_value
= SSH2_MSG_KEX_DH_GEX_REPLY
;
4075 ssh
->pkt_ctx
|= SSH2_PKTCTX_DHGROUP1
;
4076 ssh
->kex_ctx
= dh_setup_group1();
4077 s
->kex_init_value
= SSH2_MSG_KEXDH_INIT
;
4078 s
->kex_reply_value
= SSH2_MSG_KEXDH_REPLY
;
4081 logevent("Doing Diffie-Hellman key exchange");
4083 * Now generate and send e for Diffie-Hellman.
4085 s
->e
= dh_create_e(ssh
->kex_ctx
, s
->nbits
* 2);
4086 ssh2_pkt_init(ssh
, s
->kex_init_value
);
4087 ssh2_pkt_addmp(ssh
, s
->e
);
4091 if (ssh
->pktin
.type
!= s
->kex_reply_value
) {
4092 bombout(("expected key exchange reply packet from server"));
4095 ssh2_pkt_getstring(ssh
, &s
->hostkeydata
, &s
->hostkeylen
);
4096 s
->f
= ssh2_pkt_getmp(ssh
);
4097 ssh2_pkt_getstring(ssh
, &s
->sigdata
, &s
->siglen
);
4099 s
->K
= dh_find_K(ssh
->kex_ctx
, s
->f
);
4101 sha_string(&ssh
->exhash
, s
->hostkeydata
, s
->hostkeylen
);
4102 if (ssh
->kex
== &ssh_diffiehellman_gex
) {
4103 sha_uint32(&ssh
->exhash
, s
->pbits
);
4104 sha_mpint(&ssh
->exhash
, s
->p
);
4105 sha_mpint(&ssh
->exhash
, s
->g
);
4107 sha_mpint(&ssh
->exhash
, s
->e
);
4108 sha_mpint(&ssh
->exhash
, s
->f
);
4109 sha_mpint(&ssh
->exhash
, s
->K
);
4110 SHA_Final(&ssh
->exhash
, s
->exchange_hash
);
4112 dh_cleanup(ssh
->kex_ctx
);
4113 ssh
->kex_ctx
= NULL
;
4116 debug(("Exchange hash is:\n"));
4117 dmemdump(s
->exchange_hash
, 20);
4120 s
->hkey
= ssh
->hostkey
->newkey(s
->hostkeydata
, s
->hostkeylen
);
4122 !ssh
->hostkey
->verifysig(s
->hkey
, s
->sigdata
, s
->siglen
,
4123 (char *)s
->exchange_hash
, 20)) {
4124 bombout(("Server's host key did not match the signature supplied"));
4129 * Authenticate remote host: verify host key. (We've already
4130 * checked the signature of the exchange hash.)
4132 s
->keystr
= ssh
->hostkey
->fmtkey(s
->hkey
);
4133 s
->fingerprint
= ssh
->hostkey
->fingerprint(s
->hkey
);
4134 verify_ssh_host_key(ssh
->frontend
,
4135 ssh
->savedhost
, ssh
->savedport
, ssh
->hostkey
->keytype
,
4136 s
->keystr
, s
->fingerprint
);
4137 if (s
->first_kex
) { /* don't bother logging this in rekeys */
4138 logevent("Host key fingerprint is:");
4139 logevent(s
->fingerprint
);
4141 sfree(s
->fingerprint
);
4143 ssh
->hostkey
->freekey(s
->hkey
);
4146 * Send SSH2_MSG_NEWKEYS.
4148 ssh2_pkt_init(ssh
, SSH2_MSG_NEWKEYS
);
4152 * Expect SSH2_MSG_NEWKEYS from server.
4155 if (ssh
->pktin
.type
!= SSH2_MSG_NEWKEYS
) {
4156 bombout(("expected new-keys packet from server"));
4161 * Create and initialise session keys.
4163 if (ssh
->cs_cipher_ctx
)
4164 ssh
->cscipher
->free_context(ssh
->cs_cipher_ctx
);
4165 ssh
->cscipher
= s
->cscipher_tobe
;
4166 ssh
->cs_cipher_ctx
= ssh
->cscipher
->make_context();
4168 if (ssh
->sc_cipher_ctx
)
4169 ssh
->sccipher
->free_context(ssh
->sc_cipher_ctx
);
4170 ssh
->sccipher
= s
->sccipher_tobe
;
4171 ssh
->sc_cipher_ctx
= ssh
->sccipher
->make_context();
4173 if (ssh
->cs_mac_ctx
)
4174 ssh
->csmac
->free_context(ssh
->cs_mac_ctx
);
4175 ssh
->csmac
= s
->csmac_tobe
;
4176 ssh
->cs_mac_ctx
= ssh
->csmac
->make_context();
4178 if (ssh
->sc_mac_ctx
)
4179 ssh
->scmac
->free_context(ssh
->sc_mac_ctx
);
4180 ssh
->scmac
= s
->scmac_tobe
;
4181 ssh
->sc_mac_ctx
= ssh
->scmac
->make_context();
4183 if (ssh
->cs_comp_ctx
)
4184 ssh
->cscomp
->compress_cleanup(ssh
->cs_comp_ctx
);
4185 ssh
->cscomp
= s
->cscomp_tobe
;
4186 ssh
->cs_comp_ctx
= ssh
->cscomp
->compress_init();
4188 if (ssh
->sc_comp_ctx
)
4189 ssh
->sccomp
->decompress_cleanup(ssh
->sc_comp_ctx
);
4190 ssh
->sccomp
= s
->sccomp_tobe
;
4191 ssh
->sc_comp_ctx
= ssh
->sccomp
->decompress_init();
4194 * Set IVs after keys. Here we use the exchange hash from the
4195 * _first_ key exchange.
4198 unsigned char keyspace
[40];
4200 memcpy(ssh
->v2_session_id
, s
->exchange_hash
,
4201 sizeof(s
->exchange_hash
));
4202 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'C',keyspace
);
4203 ssh
->cscipher
->setkey(ssh
->cs_cipher_ctx
, keyspace
);
4204 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'D',keyspace
);
4205 ssh
->sccipher
->setkey(ssh
->sc_cipher_ctx
, keyspace
);
4206 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'A',keyspace
);
4207 ssh
->cscipher
->setiv(ssh
->cs_cipher_ctx
, keyspace
);
4208 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'B',keyspace
);
4209 ssh
->sccipher
->setiv(ssh
->sc_cipher_ctx
, keyspace
);
4210 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'E',keyspace
);
4211 ssh
->csmac
->setkey(ssh
->cs_mac_ctx
, keyspace
);
4212 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'F',keyspace
);
4213 ssh
->scmac
->setkey(ssh
->sc_mac_ctx
, keyspace
);
4215 logeventf(ssh
, "Initialised %.200s client->server encryption",
4216 ssh
->cscipher
->text_name
);
4217 logeventf(ssh
, "Initialised %.200s server->client encryption",
4218 ssh
->sccipher
->text_name
);
4219 if (ssh
->cscomp
->text_name
)
4220 logeventf(ssh
, "Initialised %s compression",
4221 ssh
->cscomp
->text_name
);
4222 if (ssh
->sccomp
->text_name
)
4223 logeventf(ssh
, "Initialised %s decompression",
4224 ssh
->sccomp
->text_name
);
4227 * If this is the first key exchange phase, we must pass the
4228 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4229 * wants to see it but because it will need time to initialise
4230 * itself before it sees an actual packet. In subsequent key
4231 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4232 * it would only confuse the layer above.
4234 if (!s
->first_kex
) {
4240 * Now we're encrypting. Begin returning 1 to the protocol main
4241 * function so that other things can run on top of the
4242 * transport. If we ever see a KEXINIT, we must go back to the
4245 while (!(ispkt
&& ssh
->pktin
.type
== SSH2_MSG_KEXINIT
)) {
4248 logevent("Server initiated key re-exchange");
4249 goto begin_key_exchange
;
4255 * Add data to an SSH2 channel output buffer.
4257 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
4260 bufchain_add(&c
->v
.v2
.outbuffer
, buf
, len
);
4264 * Attempt to send data on an SSH2 channel.
4266 static int ssh2_try_send(struct ssh_channel
*c
)
4270 while (c
->v
.v2
.remwindow
> 0 && bufchain_size(&c
->v
.v2
.outbuffer
) > 0) {
4273 bufchain_prefix(&c
->v
.v2
.outbuffer
, &data
, &len
);
4274 if ((unsigned)len
> c
->v
.v2
.remwindow
)
4275 len
= c
->v
.v2
.remwindow
;
4276 if ((unsigned)len
> c
->v
.v2
.remmaxpkt
)
4277 len
= c
->v
.v2
.remmaxpkt
;
4278 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_DATA
);
4279 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
4280 ssh2_pkt_addstring_start(ssh
);
4281 ssh2_pkt_addstring_data(ssh
, data
, len
);
4283 bufchain_consume(&c
->v
.v2
.outbuffer
, len
);
4284 c
->v
.v2
.remwindow
-= len
;
4288 * After having sent as much data as we can, return the amount
4291 return bufchain_size(&c
->v
.v2
.outbuffer
);
4295 * Potentially enlarge the window on an SSH2 channel.
4297 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
)
4302 * Never send WINDOW_ADJUST for a channel that the remote side
4303 * already thinks it's closed; there's no point, since it won't
4304 * be sending any more data anyway.
4309 if (newwin
> c
->v
.v2
.locwindow
) {
4310 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4311 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
4312 ssh2_pkt_adduint32(ssh
, newwin
- c
->v
.v2
.locwindow
);
4314 c
->v
.v2
.locwindow
= newwin
;
4319 * Handle the SSH2 userauth and connection layers.
4321 static void do_ssh2_authconn(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
4323 struct do_ssh2_authconn_state
{
4325 AUTH_INVALID
, AUTH_PUBLICKEY_AGENT
, AUTH_PUBLICKEY_FILE
,
4327 AUTH_KEYBOARD_INTERACTIVE
4331 AUTH_TYPE_PUBLICKEY
,
4332 AUTH_TYPE_PUBLICKEY_OFFER_LOUD
,
4333 AUTH_TYPE_PUBLICKEY_OFFER_QUIET
,
4335 AUTH_TYPE_KEYBOARD_INTERACTIVE
,
4336 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4338 int gotit
, need_pw
, can_pubkey
, can_passwd
, can_keyb_inter
;
4339 int tried_pubkey_config
, tried_agent
, tried_keyb_inter
;
4340 int kbd_inter_running
;
4342 int num_prompts
, curr_prompt
, echo
;
4347 void *publickey_blob
;
4348 int publickey_bloblen
;
4349 unsigned char request
[5], *response
, *p
;
4353 char *pkblob
, *alg
, *commentp
;
4354 int pklen
, alglen
, commentlen
;
4355 int siglen
, retlen
, len
;
4356 char *q
, *agentreq
, *ret
;
4359 crState(do_ssh2_authconn_state
);
4361 crBegin(ssh
->do_ssh2_authconn_crstate
);
4364 * Request userauth protocol, and await a response to it.
4366 ssh2_pkt_init(ssh
, SSH2_MSG_SERVICE_REQUEST
);
4367 ssh2_pkt_addstring(ssh
, "ssh-userauth");
4369 crWaitUntilV(ispkt
);
4370 if (ssh
->pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
) {
4371 bombout(("Server refused user authentication protocol"));
4376 * We repeat this whole loop, including the username prompt,
4377 * until we manage a successful authentication. If the user
4378 * types the wrong _password_, they can be sent back to the
4379 * beginning to try another username, if this is configured on.
4380 * (If they specify a username in the config, they are never
4381 * asked, even if they do give a wrong password.)
4383 * I think this best serves the needs of
4385 * - the people who have no configuration, no keys, and just
4386 * want to try repeated (username,password) pairs until they
4387 * type both correctly
4389 * - people who have keys and configuration but occasionally
4390 * need to fall back to passwords
4392 * - people with a key held in Pageant, who might not have
4393 * logged in to a particular machine before; so they want to
4394 * type a username, and then _either_ their key will be
4395 * accepted, _or_ they will type a password. If they mistype
4396 * the username they will want to be able to get back and
4399 s
->username
[0] = '\0';
4400 s
->got_username
= FALSE
;
4405 if (s
->got_username
&& !ssh
->cfg
.change_username
) {
4407 * We got a username last time round this loop, and
4408 * with change_username turned off we don't try to get
4411 } else if ((flags
& FLAG_INTERACTIVE
) && !*ssh
->cfg
.username
) {
4412 if (ssh_get_line
&& !ssh_getline_pw_only
) {
4413 if (!ssh_get_line("login as: ",
4414 s
->username
, sizeof(s
->username
), FALSE
)) {
4416 * get_line failed to get a username.
4419 logevent("No username provided. Abandoning session.");
4420 ssh_closing((Plug
)ssh
, NULL
, 0, 0);
4424 int ret
; /* need not be saved across crReturn */
4425 c_write_str(ssh
, "login as: ");
4427 setup_userpass_input(ssh
, s
->username
, sizeof(s
->username
), 1);
4429 crWaitUntilV(!ispkt
);
4430 ret
= process_userpass_input(ssh
, in
, inlen
);
4434 c_write_str(ssh
, "\r\n");
4436 s
->username
[strcspn(s
->username
, "\n\r")] = '\0';
4439 strncpy(s
->username
, ssh
->cfg
.username
, sizeof(s
->username
));
4440 s
->username
[sizeof(s
->username
)-1] = '\0';
4441 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
4442 stuff
= dupprintf("Using username \"%s\".\r\n", s
->username
);
4443 c_write_str(ssh
, stuff
);
4447 s
->got_username
= TRUE
;
4450 * Send an authentication request using method "none": (a)
4451 * just in case it succeeds, and (b) so that we know what
4452 * authentication methods we can usefully try next.
4454 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4456 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4457 ssh2_pkt_addstring(ssh
, s
->username
);
4458 ssh2_pkt_addstring(ssh
, "ssh-connection");/* service requested */
4459 ssh2_pkt_addstring(ssh
, "none"); /* method */
4461 s
->type
= AUTH_TYPE_NONE
;
4463 s
->we_are_in
= FALSE
;
4465 s
->tried_pubkey_config
= FALSE
;
4466 s
->tried_agent
= FALSE
;
4467 s
->tried_keyb_inter
= FALSE
;
4468 s
->kbd_inter_running
= FALSE
;
4469 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
4470 if (!filename_is_null(ssh
->cfg
.keyfile
)) {
4472 logeventf(ssh
, "Reading private key file \"%.150s\"",
4473 filename_to_str(&ssh
->cfg
.keyfile
));
4474 keytype
= key_type(&ssh
->cfg
.keyfile
);
4475 if (keytype
== SSH_KEYTYPE_SSH2
) {
4477 ssh2_userkey_loadpub(&ssh
->cfg
.keyfile
, NULL
,
4478 &s
->publickey_bloblen
);
4481 logeventf(ssh
, "Unable to use this key file (%s)",
4482 key_type_to_str(keytype
));
4483 msgbuf
= dupprintf("Unable to use key file \"%.150s\""
4485 filename_to_str(&ssh
->cfg
.keyfile
),
4486 key_type_to_str(keytype
));
4487 c_write_str(ssh
, msgbuf
);
4489 s
->publickey_blob
= NULL
;
4492 s
->publickey_blob
= NULL
;
4496 * Wait for the result of the last authentication request.
4499 crWaitUntilV(ispkt
);
4500 while (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_BANNER
) {
4504 * Don't show the banner if we're operating in
4505 * non-verbose non-interactive mode. (It's probably
4506 * a script, which means nobody will read the
4507 * banner _anyway_, and moreover the printing of
4508 * the banner will screw up processing on the
4509 * output of (say) plink.)
4511 if (flags
& (FLAG_VERBOSE
| FLAG_INTERACTIVE
)) {
4512 ssh2_pkt_getstring(ssh
, &banner
, &size
);
4514 c_write_untrusted(ssh
, banner
, size
);
4516 crWaitUntilV(ispkt
);
4518 if (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_SUCCESS
) {
4519 logevent("Access granted");
4520 s
->we_are_in
= TRUE
;
4524 if (s
->kbd_inter_running
&&
4525 ssh
->pktin
.type
== SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4527 * This is either a further set-of-prompts packet
4528 * in keyboard-interactive authentication, or it's
4529 * the same one and we came back here with `gotit'
4530 * set. In the former case, we must reset the
4531 * curr_prompt variable.
4535 } else if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_FAILURE
) {
4536 bombout(("Strange packet received during authentication: type %d",
4544 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4545 * we can look at the string in it and know what we can
4546 * helpfully try next.
4548 if (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
) {
4551 ssh2_pkt_getstring(ssh
, &methods
, &methlen
);
4552 s
->kbd_inter_running
= FALSE
;
4553 if (!ssh2_pkt_getbool(ssh
)) {
4555 * We have received an unequivocal Access
4556 * Denied. This can translate to a variety of
4559 * - if we'd just tried "none" authentication,
4560 * it's not worth printing anything at all
4562 * - if we'd just tried a public key _offer_,
4563 * the message should be "Server refused our
4564 * key" (or no message at all if the key
4565 * came from Pageant)
4567 * - if we'd just tried anything else, the
4568 * message really should be "Access denied".
4570 * Additionally, if we'd just tried password
4571 * authentication, we should break out of this
4572 * whole loop so as to go back to the username
4575 if (s
->type
== AUTH_TYPE_NONE
) {
4577 } else if (s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
||
4578 s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_QUIET
) {
4579 if (s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
)
4580 c_write_str(ssh
, "Server refused our key\r\n");
4581 logevent("Server refused public key");
4582 } else if (s
->type
==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
) {
4583 /* server declined keyboard-interactive; ignore */
4585 c_write_str(ssh
, "Access denied\r\n");
4586 logevent("Access denied");
4587 if (s
->type
== AUTH_TYPE_PASSWORD
) {
4588 s
->we_are_in
= FALSE
;
4593 c_write_str(ssh
, "Further authentication required\r\n");
4594 logevent("Further authentication required");
4598 in_commasep_string("publickey", methods
, methlen
);
4600 in_commasep_string("password", methods
, methlen
);
4601 s
->can_keyb_inter
= ssh
->cfg
.try_ki_auth
&&
4602 in_commasep_string("keyboard-interactive", methods
, methlen
);
4606 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4609 * Most password/passphrase prompts will be
4610 * non-echoing, so we set this to 0 by default.
4611 * Exception is that some keyboard-interactive prompts
4612 * can be echoing, in which case we'll set this to 1.
4616 if (!s
->method
&& s
->can_pubkey
&&
4617 agent_exists() && !s
->tried_agent
) {
4619 * Attempt public-key authentication using Pageant.
4624 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4625 ssh
->pkt_ctx
|= SSH2_PKTCTX_PUBLICKEY
;
4627 s
->tried_agent
= TRUE
;
4629 logevent("Pageant is running. Requesting keys.");
4631 /* Request the keys held by the agent. */
4632 PUT_32BIT(s
->request
, 1);
4633 s
->request
[4] = SSH2_AGENTC_REQUEST_IDENTITIES
;
4634 agent_query(s
->request
, 5, &r
, &s
->responselen
);
4635 s
->response
= (unsigned char *) r
;
4636 if (s
->response
&& s
->responselen
>= 5 &&
4637 s
->response
[4] == SSH2_AGENT_IDENTITIES_ANSWER
) {
4638 s
->p
= s
->response
+ 5;
4639 s
->nkeys
= GET_32BIT(s
->p
);
4643 sprintf(buf
, "Pageant has %d SSH2 keys", s
->nkeys
);
4646 for (s
->keyi
= 0; s
->keyi
< s
->nkeys
; s
->keyi
++) {
4651 sprintf(buf
, "Trying Pageant key #%d", s
->keyi
);
4654 s
->pklen
= GET_32BIT(s
->p
);
4656 if (s
->publickey_blob
&&
4657 s
->pklen
== s
->publickey_bloblen
&&
4658 !memcmp(s
->p
, s
->publickey_blob
,
4659 s
->publickey_bloblen
)) {
4660 logevent("This key matches configured key file");
4661 s
->tried_pubkey_config
= 1;
4663 s
->pkblob
= (char *)s
->p
;
4665 s
->alglen
= GET_32BIT(s
->pkblob
);
4666 s
->alg
= s
->pkblob
+ 4;
4667 s
->commentlen
= GET_32BIT(s
->p
);
4669 s
->commentp
= (char *)s
->p
;
4670 s
->p
+= s
->commentlen
;
4671 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4672 ssh2_pkt_addstring(ssh
, s
->username
);
4673 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4674 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4675 ssh2_pkt_addbool(ssh
, FALSE
); /* no signature included */
4676 ssh2_pkt_addstring_start(ssh
);
4677 ssh2_pkt_addstring_data(ssh
, s
->alg
, s
->alglen
);
4678 ssh2_pkt_addstring_start(ssh
);
4679 ssh2_pkt_addstring_data(ssh
, s
->pkblob
, s
->pklen
);
4682 crWaitUntilV(ispkt
);
4683 if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4684 logevent("Key refused");
4688 if (flags
& FLAG_VERBOSE
) {
4689 c_write_str(ssh
, "Authenticating with "
4691 c_write(ssh
, s
->commentp
, s
->commentlen
);
4692 c_write_str(ssh
, "\" from agent\r\n");
4696 * Server is willing to accept the key.
4697 * Construct a SIGN_REQUEST.
4699 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4700 ssh2_pkt_addstring(ssh
, s
->username
);
4701 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4702 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4703 ssh2_pkt_addbool(ssh
, TRUE
);
4704 ssh2_pkt_addstring_start(ssh
);
4705 ssh2_pkt_addstring_data(ssh
, s
->alg
, s
->alglen
);
4706 ssh2_pkt_addstring_start(ssh
);
4707 ssh2_pkt_addstring_data(ssh
, s
->pkblob
, s
->pklen
);
4709 s
->siglen
= ssh
->pktout
.length
- 5 + 4 + 20;
4710 if (ssh
->remote_bugs
& BUG_SSH2_PK_SESSIONID
)
4712 s
->len
= 1; /* message type */
4713 s
->len
+= 4 + s
->pklen
; /* key blob */
4714 s
->len
+= 4 + s
->siglen
; /* data to sign */
4715 s
->len
+= 4; /* flags */
4716 s
->agentreq
= snewn(4 + s
->len
, char);
4717 PUT_32BIT(s
->agentreq
, s
->len
);
4718 s
->q
= s
->agentreq
+ 4;
4719 *s
->q
++ = SSH2_AGENTC_SIGN_REQUEST
;
4720 PUT_32BIT(s
->q
, s
->pklen
);
4722 memcpy(s
->q
, s
->pkblob
, s
->pklen
);
4724 PUT_32BIT(s
->q
, s
->siglen
);
4726 /* Now the data to be signed... */
4727 if (!(ssh
->remote_bugs
& BUG_SSH2_PK_SESSIONID
)) {
4728 PUT_32BIT(s
->q
, 20);
4731 memcpy(s
->q
, ssh
->v2_session_id
, 20);
4733 memcpy(s
->q
, ssh
->pktout
.data
+ 5,
4734 ssh
->pktout
.length
- 5);
4735 s
->q
+= ssh
->pktout
.length
- 5;
4736 /* And finally the (zero) flags word. */
4738 agent_query(s
->agentreq
, s
->len
+ 4, &vret
, &s
->retlen
);
4742 if (s
->ret
[4] == SSH2_AGENT_SIGN_RESPONSE
) {
4743 logevent("Sending Pageant's response");
4744 ssh2_add_sigblob(ssh
, s
->pkblob
, s
->pklen
,
4746 GET_32BIT(s
->ret
+ 5));
4752 ("Pageant failed to answer challenge");
4762 if (!s
->method
&& s
->can_pubkey
&& s
->publickey_blob
4763 && !s
->tried_pubkey_config
) {
4764 unsigned char *pub_blob
;
4765 char *algorithm
, *comment
;
4768 s
->tried_pubkey_config
= TRUE
;
4770 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4771 ssh
->pkt_ctx
|= SSH2_PKTCTX_PUBLICKEY
;
4774 * Try the public key supplied in the configuration.
4776 * First, offer the public blob to see if the server is
4777 * willing to accept it.
4780 (unsigned char *)ssh2_userkey_loadpub(&ssh
->cfg
.keyfile
,
4784 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4785 ssh2_pkt_addstring(ssh
, s
->username
);
4786 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4787 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4788 ssh2_pkt_addbool(ssh
, FALSE
); /* no signature included */
4789 ssh2_pkt_addstring(ssh
, algorithm
);
4790 ssh2_pkt_addstring_start(ssh
);
4791 ssh2_pkt_addstring_data(ssh
, (char *)pub_blob
,
4794 logevent("Offered public key"); /* FIXME */
4796 crWaitUntilV(ispkt
);
4797 if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4799 s
->type
= AUTH_TYPE_PUBLICKEY_OFFER_LOUD
;
4800 continue; /* key refused; give up on it */
4803 logevent("Offer of public key accepted");
4805 * Actually attempt a serious authentication using
4808 if (ssh2_userkey_encrypted(&ssh
->cfg
.keyfile
, &comment
)) {
4809 sprintf(s
->pwprompt
,
4810 "Passphrase for key \"%.100s\": ",
4816 c_write_str(ssh
, "Authenticating with public key \"");
4817 c_write_str(ssh
, comment
);
4818 c_write_str(ssh
, "\"\r\n");
4819 s
->method
= AUTH_PUBLICKEY_FILE
;
4823 if (!s
->method
&& s
->can_keyb_inter
&& !s
->tried_keyb_inter
) {
4824 s
->method
= AUTH_KEYBOARD_INTERACTIVE
;
4825 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4826 s
->tried_keyb_inter
= TRUE
;
4828 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4829 ssh
->pkt_ctx
|= SSH2_PKTCTX_KBDINTER
;
4831 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4832 ssh2_pkt_addstring(ssh
, s
->username
);
4833 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4834 ssh2_pkt_addstring(ssh
, "keyboard-interactive"); /* method */
4835 ssh2_pkt_addstring(ssh
, ""); /* lang */
4836 ssh2_pkt_addstring(ssh
, "");
4839 crWaitUntilV(ispkt
);
4840 if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4841 if (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
)
4843 logevent("Keyboard-interactive authentication refused");
4844 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
;
4848 s
->kbd_inter_running
= TRUE
;
4852 if (s
->kbd_inter_running
) {
4853 s
->method
= AUTH_KEYBOARD_INTERACTIVE
;
4854 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4855 s
->tried_keyb_inter
= TRUE
;
4857 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4858 ssh
->pkt_ctx
|= SSH2_PKTCTX_KBDINTER
;
4860 if (s
->curr_prompt
== 0) {
4862 * We've got a fresh USERAUTH_INFO_REQUEST.
4863 * Display header data, and start going through
4866 char *name
, *inst
, *lang
;
4867 int name_len
, inst_len
, lang_len
;
4869 ssh2_pkt_getstring(ssh
, &name
, &name_len
);
4870 ssh2_pkt_getstring(ssh
, &inst
, &inst_len
);
4871 ssh2_pkt_getstring(ssh
, &lang
, &lang_len
);
4873 c_write_untrusted(ssh
, name
, name_len
);
4874 c_write_str(ssh
, "\r\n");
4877 c_write_untrusted(ssh
, inst
, inst_len
);
4878 c_write_str(ssh
, "\r\n");
4880 s
->num_prompts
= ssh2_pkt_getuint32(ssh
);
4884 * If there are prompts remaining in the packet,
4885 * display one and get a response.
4887 if (s
->curr_prompt
< s
->num_prompts
) {
4891 ssh2_pkt_getstring(ssh
, &prompt
, &prompt_len
);
4892 if (prompt_len
> 0) {
4893 strncpy(s
->pwprompt
, prompt
, sizeof(s
->pwprompt
));
4894 s
->pwprompt
[prompt_len
< sizeof(s
->pwprompt
) ?
4895 prompt_len
: sizeof(s
->pwprompt
)-1] = '\0';
4898 "<server failed to send prompt>: ");
4900 s
->echo
= ssh2_pkt_getbool(ssh
);
4906 if (!s
->method
&& s
->can_passwd
) {
4907 s
->method
= AUTH_PASSWORD
;
4908 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4909 ssh
->pkt_ctx
|= SSH2_PKTCTX_PASSWORD
;
4910 sprintf(s
->pwprompt
, "%.90s@%.90s's password: ", s
->username
,
4917 if (!ssh_get_line(s
->pwprompt
, s
->password
,
4918 sizeof(s
->password
), TRUE
)) {
4920 * get_line failed to get a password (for
4921 * example because one was supplied on the
4922 * command line which has already failed to
4925 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
4926 ssh2_pkt_adduint32(ssh
,SSH2_DISCONNECT_BY_APPLICATION
);
4927 ssh2_pkt_addstring(ssh
, "No more passwords available"
4929 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
4931 logevent("Unable to authenticate");
4932 connection_fatal(ssh
->frontend
,
4933 "Unable to authenticate");
4934 ssh_closing((Plug
)ssh
, NULL
, 0, 0);
4938 int ret
; /* need not be saved across crReturn */
4939 c_write_untrusted(ssh
, s
->pwprompt
, strlen(s
->pwprompt
));
4942 setup_userpass_input(ssh
, s
->password
,
4943 sizeof(s
->password
), s
->echo
);
4945 crWaitUntilV(!ispkt
);
4946 ret
= process_userpass_input(ssh
, in
, inlen
);
4950 c_write_str(ssh
, "\r\n");
4954 if (s
->method
== AUTH_PUBLICKEY_FILE
) {
4956 * We have our passphrase. Now try the actual authentication.
4958 struct ssh2_userkey
*key
;
4960 key
= ssh2_load_userkey(&ssh
->cfg
.keyfile
, s
->password
);
4961 if (key
== SSH2_WRONG_PASSPHRASE
|| key
== NULL
) {
4962 if (key
== SSH2_WRONG_PASSPHRASE
) {
4963 c_write_str(ssh
, "Wrong passphrase\r\n");
4964 s
->tried_pubkey_config
= FALSE
;
4966 c_write_str(ssh
, "Unable to load private key\r\n");
4967 s
->tried_pubkey_config
= TRUE
;
4969 /* Send a spurious AUTH_NONE to return to the top. */
4970 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4971 ssh2_pkt_addstring(ssh
, s
->username
);
4972 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4973 ssh2_pkt_addstring(ssh
, "none"); /* method */
4975 s
->type
= AUTH_TYPE_NONE
;
4977 unsigned char *pkblob
, *sigblob
, *sigdata
;
4978 int pkblob_len
, sigblob_len
, sigdata_len
;
4982 * We have loaded the private key and the server
4983 * has announced that it's willing to accept it.
4984 * Hallelujah. Generate a signature and send it.
4986 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4987 ssh2_pkt_addstring(ssh
, s
->username
);
4988 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4989 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4990 ssh2_pkt_addbool(ssh
, TRUE
);
4991 ssh2_pkt_addstring(ssh
, key
->alg
->name
);
4992 pkblob
= key
->alg
->public_blob(key
->data
, &pkblob_len
);
4993 ssh2_pkt_addstring_start(ssh
);
4994 ssh2_pkt_addstring_data(ssh
, (char *)pkblob
, pkblob_len
);
4997 * The data to be signed is:
5001 * followed by everything so far placed in the
5004 sigdata_len
= ssh
->pktout
.length
- 5 + 4 + 20;
5005 if (ssh
->remote_bugs
& BUG_SSH2_PK_SESSIONID
)
5007 sigdata
= snewn(sigdata_len
, unsigned char);
5009 if (!(ssh
->remote_bugs
& BUG_SSH2_PK_SESSIONID
)) {
5010 PUT_32BIT(sigdata
+p
, 20);
5013 memcpy(sigdata
+p
, ssh
->v2_session_id
, 20); p
+= 20;
5014 memcpy(sigdata
+p
, ssh
->pktout
.data
+ 5,
5015 ssh
->pktout
.length
- 5);
5016 p
+= ssh
->pktout
.length
- 5;
5017 assert(p
== sigdata_len
);
5018 sigblob
= key
->alg
->sign(key
->data
, (char *)sigdata
,
5019 sigdata_len
, &sigblob_len
);
5020 ssh2_add_sigblob(ssh
, pkblob
, pkblob_len
,
5021 sigblob
, sigblob_len
);
5027 s
->type
= AUTH_TYPE_PUBLICKEY
;
5029 } else if (s
->method
== AUTH_PASSWORD
) {
5031 * We send the password packet lumped tightly together with
5032 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
5033 * string long enough to make the total length of the two
5034 * packets constant. This should ensure that a passive
5035 * listener doing traffic analyis can't work out the length
5038 * For this to work, we need an assumption about the
5039 * maximum length of the password packet. I think 256 is
5040 * pretty conservative. Anyone using a password longer than
5041 * that probably doesn't have much to worry about from
5042 * people who find out how long their password is!
5044 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
5045 ssh2_pkt_addstring(ssh
, s
->username
);
5046 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
5047 ssh2_pkt_addstring(ssh
, "password");
5048 ssh2_pkt_addbool(ssh
, FALSE
);
5049 ssh2_pkt_addstring(ssh
, s
->password
);
5050 memset(s
->password
, 0, sizeof(s
->password
));
5051 ssh2_pkt_defer(ssh
);
5053 * We'll include a string that's an exact multiple of the
5054 * cipher block size. If the cipher is NULL for some
5055 * reason, we don't do this trick at all because we gain
5058 if (ssh
->cscipher
) {
5061 stringlen
= (256 - ssh
->deferred_len
);
5062 stringlen
+= ssh
->cscipher
->blksize
- 1;
5063 stringlen
-= (stringlen
% ssh
->cscipher
->blksize
);
5066 * Temporarily disable actual compression,
5067 * so we can guarantee to get this string
5068 * exactly the length we want it. The
5069 * compression-disabling routine should
5070 * return an integer indicating how many
5071 * bytes we should adjust our string length
5075 ssh
->cscomp
->disable_compression(ssh
->cs_comp_ctx
);
5077 ssh2_pkt_init(ssh
, SSH2_MSG_IGNORE
);
5078 ssh2_pkt_addstring_start(ssh
);
5079 for (i
= 0; i
< stringlen
; i
++) {
5080 char c
= (char) random_byte();
5081 ssh2_pkt_addstring_data(ssh
, &c
, 1);
5083 ssh2_pkt_defer(ssh
);
5085 ssh_pkt_defersend(ssh
);
5086 logevent("Sent password");
5087 s
->type
= AUTH_TYPE_PASSWORD
;
5088 } else if (s
->method
== AUTH_KEYBOARD_INTERACTIVE
) {
5089 if (s
->curr_prompt
== 0) {
5090 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_INFO_RESPONSE
);
5091 ssh2_pkt_adduint32(ssh
, s
->num_prompts
);
5093 if (s
->need_pw
) { /* only add pw if we just got one! */
5094 ssh2_pkt_addstring(ssh
, s
->password
);
5095 memset(s
->password
, 0, sizeof(s
->password
));
5098 if (s
->curr_prompt
>= s
->num_prompts
) {
5102 * If there are prompts remaining, we set
5103 * `gotit' so that we won't attempt to get
5104 * another packet. Then we go back round the
5105 * loop and will end up retrieving another
5106 * prompt out of the existing packet. Funky or
5111 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
5113 c_write_str(ssh
, "No supported authentication methods"
5114 " left to try!\r\n");
5115 logevent("No supported authentications offered."
5117 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
5118 ssh2_pkt_adduint32(ssh
, SSH2_DISCONNECT_BY_APPLICATION
);
5119 ssh2_pkt_addstring(ssh
, "No supported authentication"
5120 " methods available");
5121 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5123 ssh_closing((Plug
)ssh
, NULL
, 0, 0);
5127 } while (!s
->we_are_in
);
5130 * Now we're authenticated for the connection protocol. The
5131 * connection protocol will automatically have started at this
5132 * point; there's no need to send SERVICE_REQUEST.
5136 * So now create a channel with a session in it.
5138 ssh
->channels
= newtree234(ssh_channelcmp
);
5139 ssh
->mainchan
= snew(struct ssh_channel
);
5140 ssh
->mainchan
->ssh
= ssh
;
5141 ssh
->mainchan
->localid
= alloc_channel_id(ssh
);
5142 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN
);
5143 ssh2_pkt_addstring(ssh
, "session");
5144 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->localid
);
5145 ssh
->mainchan
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5146 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->v
.v2
.locwindow
);/* our window size */
5147 ssh2_pkt_adduint32(ssh
, 0x4000UL
); /* our max pkt size */
5149 crWaitUntilV(ispkt
);
5150 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
5151 bombout(("Server refused to open a session"));
5153 /* FIXME: error data comes back in FAILURE packet */
5155 if (ssh2_pkt_getuint32(ssh
) != ssh
->mainchan
->localid
) {
5156 bombout(("Server's channel confirmation cited wrong channel"));
5159 ssh
->mainchan
->remoteid
= ssh2_pkt_getuint32(ssh
);
5160 ssh
->mainchan
->type
= CHAN_MAINSESSION
;
5161 ssh
->mainchan
->closes
= 0;
5162 ssh
->mainchan
->v
.v2
.remwindow
= ssh2_pkt_getuint32(ssh
);
5163 ssh
->mainchan
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32(ssh
);
5164 bufchain_init(&ssh
->mainchan
->v
.v2
.outbuffer
);
5165 add234(ssh
->channels
, ssh
->mainchan
);
5166 logevent("Opened channel for session");
5169 * Potentially enable X11 forwarding.
5171 if (ssh
->cfg
.x11_forward
) {
5172 char proto
[20], data
[64];
5173 logevent("Requesting X11 forwarding");
5174 ssh
->x11auth
= x11_invent_auth(proto
, sizeof(proto
),
5175 data
, sizeof(data
), ssh
->cfg
.x11_auth
);
5176 x11_get_real_auth(ssh
->x11auth
, ssh
->cfg
.x11_display
);
5177 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5178 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
5179 ssh2_pkt_addstring(ssh
, "x11-req");
5180 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5181 ssh2_pkt_addbool(ssh
, 0); /* many connections */
5182 ssh2_pkt_addstring(ssh
, proto
);
5183 ssh2_pkt_addstring(ssh
, data
);
5184 ssh2_pkt_adduint32(ssh
, x11_get_screen_number(ssh
->cfg
.x11_display
));
5188 crWaitUntilV(ispkt
);
5189 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5190 unsigned i
= ssh2_pkt_getuint32(ssh
);
5191 struct ssh_channel
*c
;
5192 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5194 continue; /* nonexistent channel */
5195 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5197 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5199 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5200 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5201 bombout(("Unexpected response to X11 forwarding request:"
5202 " packet type %d", ssh
->pktin
.type
));
5205 logevent("X11 forwarding refused");
5207 logevent("X11 forwarding enabled");
5208 ssh
->X11_fwd_enabled
= TRUE
;
5213 * Enable port forwardings.
5218 int sport
,dport
,sserv
,dserv
;
5219 char sports
[256], dports
[256], saddr
[256], host
[256];
5221 ssh
->rportfwds
= newtree234(ssh_rportcmp_ssh2
);
5222 /* Add port forwardings. */
5223 ssh
->portfwd_strptr
= ssh
->cfg
.portfwd
;
5224 while (*ssh
->portfwd_strptr
) {
5225 type
= *ssh
->portfwd_strptr
++;
5228 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= '\t') {
5229 if (*ssh
->portfwd_strptr
== ':') {
5231 * We've seen a colon in the middle of the
5232 * source port number. This means that
5233 * everything we've seen until now is the
5234 * source _address_, so we'll move it into
5235 * saddr and start sports from the beginning
5238 ssh
->portfwd_strptr
++;
5240 strcpy(saddr
, sports
);
5243 if (n
< 255) sports
[n
++] = *ssh
->portfwd_strptr
++;
5247 if (*ssh
->portfwd_strptr
== '\t')
5248 ssh
->portfwd_strptr
++;
5250 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= ':') {
5251 if (n
< 255) host
[n
++] = *ssh
->portfwd_strptr
++;
5254 if (*ssh
->portfwd_strptr
== ':')
5255 ssh
->portfwd_strptr
++;
5257 while (*ssh
->portfwd_strptr
) {
5258 if (n
< 255) dports
[n
++] = *ssh
->portfwd_strptr
++;
5261 ssh
->portfwd_strptr
++;
5262 dport
= atoi(dports
);
5266 dport
= net_service_lookup(dports
);
5268 logeventf(ssh
, "Service lookup failed for destination"
5269 " port \"%s\"", dports
);
5273 while (*ssh
->portfwd_strptr
) ssh
->portfwd_strptr
++;
5275 sport
= atoi(sports
);
5279 sport
= net_service_lookup(sports
);
5281 logeventf(ssh
, "Service lookup failed for source"
5282 " port \"%s\"", sports
);
5285 if (sport
&& dport
) {
5287 pfd_addforward(host
, dport
, *saddr ? saddr
: NULL
,
5288 sport
, ssh
, &ssh
->cfg
);
5289 logeventf(ssh
, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5290 " forwarding to %s:%.*s%.*s%d%.*s",
5291 (int)(*saddr?
strlen(saddr
):0), *saddr?saddr
:NULL
,
5292 (int)(*saddr?
1:0), ":",
5293 (int)(sserv ?
strlen(sports
) : 0), sports
,
5294 sserv
, "(", sport
, sserv
, ")",
5296 (int)(dserv ?
strlen(dports
) : 0), dports
,
5297 dserv
, "(", dport
, dserv
, ")");
5298 } else if (type
== 'D') {
5299 pfd_addforward(NULL
, -1, *saddr ? saddr
: NULL
,
5300 sport
, ssh
, &ssh
->cfg
);
5301 logeventf(ssh
, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5302 " doing SOCKS dynamic forwarding",
5303 (int)(*saddr?
strlen(saddr
):0), *saddr?saddr
:NULL
,
5304 (int)(*saddr?
1:0), ":",
5305 (int)(sserv ?
strlen(sports
) : 0), sports
,
5306 sserv
, "(", sport
, sserv
, ")");
5308 struct ssh_rportfwd
*pf
;
5309 pf
= snew(struct ssh_rportfwd
);
5310 strcpy(pf
->dhost
, host
);
5313 if (add234(ssh
->rportfwds
, pf
) != pf
) {
5314 logeventf(ssh
, "Duplicate remote port forwarding"
5315 " to %s:%d", host
, dport
);
5318 logeventf(ssh
, "Requesting remote port "
5319 "%.*s%.*s%.*s%.*s%d%.*s"
5320 " forward to %s:%.*s%.*s%d%.*s",
5321 (int)(*saddr?
strlen(saddr
):0),
5323 (int)(*saddr?
1:0), ":",
5324 (int)(sserv ?
strlen(sports
) : 0), sports
,
5325 sserv
, "(", sport
, sserv
, ")",
5327 (int)(dserv ?
strlen(dports
) : 0), dports
,
5328 dserv
, "(", dport
, dserv
, ")");
5329 ssh2_pkt_init(ssh
, SSH2_MSG_GLOBAL_REQUEST
);
5330 ssh2_pkt_addstring(ssh
, "tcpip-forward");
5331 ssh2_pkt_addbool(ssh
, 1);/* want reply */
5333 ssh2_pkt_addstring(ssh
, saddr
);
5334 if (ssh
->cfg
.rport_acceptall
)
5335 ssh2_pkt_addstring(ssh
, "0.0.0.0");
5337 ssh2_pkt_addstring(ssh
, "127.0.0.1");
5338 ssh2_pkt_adduint32(ssh
, sport
);
5342 crWaitUntilV(ispkt
);
5343 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5344 unsigned i
= ssh2_pkt_getuint32(ssh
);
5345 struct ssh_channel
*c
;
5346 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5348 continue;/* nonexistent channel */
5349 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5351 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5353 if (ssh
->pktin
.type
!= SSH2_MSG_REQUEST_SUCCESS
) {
5354 if (ssh
->pktin
.type
!= SSH2_MSG_REQUEST_FAILURE
) {
5355 bombout(("Unexpected response to port "
5356 "forwarding request: packet type %d",
5360 logevent("Server refused this port forwarding");
5362 logevent("Remote port forwarding enabled");
5371 * Potentially enable agent forwarding.
5373 if (ssh
->cfg
.agentfwd
&& agent_exists()) {
5374 logevent("Requesting OpenSSH-style agent forwarding");
5375 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5376 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
5377 ssh2_pkt_addstring(ssh
, "auth-agent-req@openssh.com");
5378 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5382 crWaitUntilV(ispkt
);
5383 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5384 unsigned i
= ssh2_pkt_getuint32(ssh
);
5385 struct ssh_channel
*c
;
5386 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5388 continue; /* nonexistent channel */
5389 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5391 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5393 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5394 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5395 bombout(("Unexpected response to agent forwarding request:"
5396 " packet type %d", ssh
->pktin
.type
));
5399 logevent("Agent forwarding refused");
5401 logevent("Agent forwarding enabled");
5402 ssh
->agentfwd_enabled
= TRUE
;
5407 * Now allocate a pty for the session.
5409 if (!ssh
->cfg
.nopty
) {
5410 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5411 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
); /* recipient channel */
5412 ssh2_pkt_addstring(ssh
, "pty-req");
5413 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5414 ssh2_pkt_addstring(ssh
, ssh
->cfg
.termtype
);
5415 ssh2_pkt_adduint32(ssh
, ssh
->term_width
);
5416 ssh2_pkt_adduint32(ssh
, ssh
->term_height
);
5417 ssh2_pkt_adduint32(ssh
, 0); /* pixel width */
5418 ssh2_pkt_adduint32(ssh
, 0); /* pixel height */
5419 ssh2_pkt_addstring_start(ssh
);
5420 ssh2_pkt_addstring_data(ssh
, "\0", 1); /* TTY_OP_END, no special options */
5422 ssh
->state
= SSH_STATE_INTERMED
;
5425 crWaitUntilV(ispkt
);
5426 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5427 unsigned i
= ssh2_pkt_getuint32(ssh
);
5428 struct ssh_channel
*c
;
5429 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5431 continue; /* nonexistent channel */
5432 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5434 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5436 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5437 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5438 bombout(("Unexpected response to pty request:"
5439 " packet type %d", ssh
->pktin
.type
));
5442 c_write_str(ssh
, "Server refused to allocate pty\r\n");
5443 ssh
->editing
= ssh
->echoing
= 1;
5445 logevent("Allocated pty");
5448 ssh
->editing
= ssh
->echoing
= 1;
5452 * Start a shell or a remote command. We may have to attempt
5453 * this twice if the config data has provided a second choice
5460 if (ssh
->fallback_cmd
) {
5461 subsys
= ssh
->cfg
.ssh_subsys2
;
5462 cmd
= ssh
->cfg
.remote_cmd_ptr2
;
5464 subsys
= ssh
->cfg
.ssh_subsys
;
5465 cmd
= ssh
->cfg
.remote_cmd_ptr
;
5468 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5469 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
); /* recipient channel */
5471 ssh2_pkt_addstring(ssh
, "subsystem");
5472 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5473 ssh2_pkt_addstring(ssh
, cmd
);
5475 ssh2_pkt_addstring(ssh
, "exec");
5476 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5477 ssh2_pkt_addstring(ssh
, cmd
);
5479 ssh2_pkt_addstring(ssh
, "shell");
5480 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5484 crWaitUntilV(ispkt
);
5485 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5486 unsigned i
= ssh2_pkt_getuint32(ssh
);
5487 struct ssh_channel
*c
;
5488 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5490 continue; /* nonexistent channel */
5491 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5493 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5494 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5495 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5496 bombout(("Unexpected response to shell/command request:"
5497 " packet type %d", ssh
->pktin
.type
));
5501 * We failed to start the command. If this is the
5502 * fallback command, we really are finished; if it's
5503 * not, and if the fallback command exists, try falling
5504 * back to it before complaining.
5506 if (!ssh
->fallback_cmd
&& ssh
->cfg
.remote_cmd_ptr2
!= NULL
) {
5507 logevent("Primary command failed; attempting fallback");
5508 ssh
->fallback_cmd
= TRUE
;
5511 bombout(("Server refused to start a shell/command"));
5514 logevent("Started a shell/command");
5519 ssh
->state
= SSH_STATE_SESSION
;
5520 if (ssh
->size_needed
)
5521 ssh_size(ssh
, ssh
->term_width
, ssh
->term_height
);
5522 if (ssh
->eof_needed
)
5523 ssh_special(ssh
, TS_EOF
);
5529 ldisc_send(ssh
->ldisc
, NULL
, 0, 0);/* cause ldisc to notice changes */
5533 s
->try_send
= FALSE
;
5535 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
5536 ssh
->pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
5539 unsigned i
= ssh2_pkt_getuint32(ssh
);
5540 struct ssh_channel
*c
;
5541 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5543 continue; /* nonexistent channel */
5544 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
5545 ssh2_pkt_getuint32(ssh
) != SSH2_EXTENDED_DATA_STDERR
)
5546 continue; /* extended but not stderr */
5547 ssh2_pkt_getstring(ssh
, &data
, &length
);
5550 c
->v
.v2
.locwindow
-= length
;
5552 case CHAN_MAINSESSION
:
5554 from_backend(ssh
->frontend
, ssh
->pktin
.type
==
5555 SSH2_MSG_CHANNEL_EXTENDED_DATA
,
5559 bufsize
= x11_send(c
->u
.x11
.s
, data
, length
);
5562 bufsize
= pfd_send(c
->u
.pfd
.s
, data
, length
);
5565 while (length
> 0) {
5566 if (c
->u
.a
.lensofar
< 4) {
5567 int l
= min(4 - c
->u
.a
.lensofar
, length
);
5568 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
,
5572 c
->u
.a
.lensofar
+= l
;
5574 if (c
->u
.a
.lensofar
== 4) {
5576 4 + GET_32BIT(c
->u
.a
.msglen
);
5577 c
->u
.a
.message
= snewn(c
->u
.a
.totallen
,
5579 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
5581 if (c
->u
.a
.lensofar
>= 4 && length
> 0) {
5583 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
5585 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
,
5589 c
->u
.a
.lensofar
+= l
;
5591 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
5592 void *reply
, *sentreply
;
5594 agent_query(c
->u
.a
.message
,
5595 c
->u
.a
.totallen
, &reply
,
5600 /* Fake SSH_AGENT_FAILURE. */
5601 sentreply
= "\0\0\0\1\5";
5604 ssh2_add_channel_data(c
, sentreply
, replylen
);
5608 sfree(c
->u
.a
.message
);
5609 c
->u
.a
.lensofar
= 0;
5616 * If we are not buffering too much data,
5617 * enlarge the window again at the remote side.
5619 if (bufsize
< OUR_V2_WINSIZE
)
5620 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
5622 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_EOF
) {
5623 unsigned i
= ssh2_pkt_getuint32(ssh
);
5624 struct ssh_channel
*c
;
5626 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5628 continue; /* nonexistent channel */
5630 if (c
->type
== CHAN_X11
) {
5632 * Remote EOF on an X11 channel means we should
5633 * wrap up and close the channel ourselves.
5635 x11_close(c
->u
.x11
.s
);
5637 } else if (c
->type
== CHAN_AGENT
) {
5639 } else if (c
->type
== CHAN_SOCKDATA
) {
5640 pfd_close(c
->u
.pfd
.s
);
5643 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_CLOSE
) {
5644 unsigned i
= ssh2_pkt_getuint32(ssh
);
5645 struct ssh_channel
*c
;
5647 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5648 if (!c
|| ((int)c
->remoteid
) == -1) {
5649 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5650 c ?
"half-open" : "nonexistent", i
));
5652 /* Do pre-close processing on the channel. */
5654 case CHAN_MAINSESSION
:
5655 break; /* nothing to see here, move along */
5657 if (c
->u
.x11
.s
!= NULL
)
5658 x11_close(c
->u
.x11
.s
);
5665 if (c
->u
.pfd
.s
!= NULL
)
5666 pfd_close(c
->u
.pfd
.s
);
5670 if (c
->closes
== 0) {
5671 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_CLOSE
);
5672 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5675 del234(ssh
->channels
, c
);
5676 bufchain_clear(&c
->v
.v2
.outbuffer
);
5680 * See if that was the last channel left open.
5682 if (count234(ssh
->channels
) == 0) {
5683 logevent("All channels closed. Disconnecting");
5686 * We used to send SSH_MSG_DISCONNECT here,
5687 * because I'd believed that _every_ conforming
5688 * SSH2 connection had to end with a disconnect
5689 * being sent by at least one side; apparently
5690 * I was wrong and it's perfectly OK to
5691 * unceremoniously slam the connection shut
5692 * when you're done, and indeed OpenSSH feels
5693 * this is more polite than sending a
5694 * DISCONNECT. So now we don't.
5696 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
5697 ssh2_pkt_adduint32(ssh
, SSH2_DISCONNECT_BY_APPLICATION
);
5698 ssh2_pkt_addstring(ssh
, "All open channels closed");
5699 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5702 ssh_closing((Plug
)ssh
, NULL
, 0, 0);
5705 continue; /* remote sends close; ignore (FIXME) */
5706 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5707 unsigned i
= ssh2_pkt_getuint32(ssh
);
5708 struct ssh_channel
*c
;
5709 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5710 if (!c
|| c
->closes
)
5711 continue; /* nonexistent or closing channel */
5712 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5714 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
5715 unsigned i
= ssh2_pkt_getuint32(ssh
);
5716 struct ssh_channel
*c
;
5717 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5719 continue; /* nonexistent channel */
5720 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
5721 continue; /* dunno why they're confirming this */
5722 c
->remoteid
= ssh2_pkt_getuint32(ssh
);
5723 c
->type
= CHAN_SOCKDATA
;
5724 c
->v
.v2
.remwindow
= ssh2_pkt_getuint32(ssh
);
5725 c
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32(ssh
);
5727 pfd_confirm(c
->u
.pfd
.s
);
5730 * We have a pending close on this channel,
5731 * which we decided on before the server acked
5732 * the channel open. So now we know the
5733 * remoteid, we can close it again.
5735 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_CLOSE
);
5736 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5739 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_OPEN_FAILURE
) {
5740 unsigned i
= ssh2_pkt_getuint32(ssh
);
5741 struct ssh_channel
*c
;
5742 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5744 continue; /* nonexistent channel */
5745 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
5746 continue; /* dunno why they're failing this */
5748 logevent("Forwarded connection refused by server");
5750 pfd_close(c
->u
.pfd
.s
);
5752 del234(ssh
->channels
, c
);
5754 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_REQUEST
) {
5757 int typelen
, want_reply
;
5758 struct ssh_channel
*c
;
5760 localid
= ssh2_pkt_getuint32(ssh
);
5761 ssh2_pkt_getstring(ssh
, &type
, &typelen
);
5762 want_reply
= ssh2_pkt_getbool(ssh
);
5765 * First, check that the channel exists. Otherwise,
5766 * we can instantly disconnect with a rude message.
5768 c
= find234(ssh
->channels
, &localid
, ssh_channelfind
);
5771 sprintf(buf
, "Received channel request for nonexistent"
5772 " channel %d", localid
);
5774 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
5775 ssh2_pkt_adduint32(ssh
, SSH2_DISCONNECT_BY_APPLICATION
);
5776 ssh2_pkt_addstring(ssh
, buf
);
5777 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5779 connection_fatal(ssh
->frontend
, "%s", buf
);
5780 ssh_closing((Plug
)ssh
, NULL
, 0, 0);
5785 * Having got the channel number, we now look at
5786 * the request type string to see if it's something
5789 if (typelen
== 11 && !memcmp(type
, "exit-status", 11) &&
5790 c
== ssh
->mainchan
) {
5791 /* We recognise "exit-status" on the primary channel. */
5793 ssh
->exitcode
= ssh2_pkt_getuint32(ssh
);
5794 sprintf(buf
, "Server sent command exit status %d",
5798 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_SUCCESS
);
5799 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5804 * This is a channel request we don't know
5805 * about, so we now either ignore the request
5806 * or respond with CHANNEL_FAILURE, depending
5810 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_FAILURE
);
5811 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5815 } else if (ssh
->pktin
.type
== SSH2_MSG_GLOBAL_REQUEST
) {
5817 int typelen
, want_reply
;
5819 ssh2_pkt_getstring(ssh
, &type
, &typelen
);
5820 want_reply
= ssh2_pkt_getbool(ssh
);
5823 * We currently don't support any global requests
5824 * at all, so we either ignore the request or
5825 * respond with REQUEST_FAILURE, depending on
5829 ssh2_pkt_init(ssh
, SSH2_MSG_REQUEST_FAILURE
);
5832 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_OPEN
) {
5839 struct ssh_channel
*c
;
5840 unsigned remid
, winsize
, pktsize
;
5841 ssh2_pkt_getstring(ssh
, &type
, &typelen
);
5842 c
= snew(struct ssh_channel
);
5845 remid
= ssh2_pkt_getuint32(ssh
);
5846 winsize
= ssh2_pkt_getuint32(ssh
);
5847 pktsize
= ssh2_pkt_getuint32(ssh
);
5849 if (typelen
== 3 && !memcmp(type
, "x11", 3)) {
5850 char *addrstr
= snewn(peeraddrlen
+1, char);
5851 memcpy(addrstr
, peeraddr
, peeraddrlen
);
5852 peeraddr
[peeraddrlen
] = '\0';
5853 ssh2_pkt_getstring(ssh
, &peeraddr
, &peeraddrlen
);
5854 peerport
= ssh2_pkt_getuint32(ssh
);
5856 if (!ssh
->X11_fwd_enabled
)
5857 error
= "X11 forwarding is not enabled";
5858 else if (x11_init(&c
->u
.x11
.s
, ssh
->cfg
.x11_display
, c
,
5859 ssh
->x11auth
, addrstr
, peerport
,
5860 &ssh
->cfg
) != NULL
) {
5861 error
= "Unable to open an X11 connection";
5867 } else if (typelen
== 15 &&
5868 !memcmp(type
, "forwarded-tcpip", 15)) {
5869 struct ssh_rportfwd pf
, *realpf
;
5872 ssh2_pkt_getstring(ssh
, &dummy
, &dummylen
);/* skip address */
5873 pf
.sport
= ssh2_pkt_getuint32(ssh
);
5874 ssh2_pkt_getstring(ssh
, &peeraddr
, &peeraddrlen
);
5875 peerport
= ssh2_pkt_getuint32(ssh
);
5876 realpf
= find234(ssh
->rportfwds
, &pf
, NULL
);
5877 if (realpf
== NULL
) {
5878 error
= "Remote port is not recognised";
5880 char *e
= pfd_newconnect(&c
->u
.pfd
.s
, realpf
->dhost
,
5881 realpf
->dport
, c
, &ssh
->cfg
);
5882 logeventf(ssh
, "Received remote port open request"
5883 " for %s:%d", realpf
->dhost
, realpf
->dport
);
5885 logeventf(ssh
, "Port open failed: %s", e
);
5886 error
= "Port open failed";
5888 logevent("Forwarded port opened successfully");
5889 c
->type
= CHAN_SOCKDATA
;
5892 } else if (typelen
== 22 &&
5893 !memcmp(type
, "auth-agent@openssh.com", 3)) {
5894 if (!ssh
->agentfwd_enabled
)
5895 error
= "Agent forwarding is not enabled";
5897 c
->type
= CHAN_AGENT
; /* identify channel type */
5898 c
->u
.a
.lensofar
= 0;
5901 error
= "Unsupported channel type requested";
5904 c
->remoteid
= remid
;
5906 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN_FAILURE
);
5907 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5908 ssh2_pkt_adduint32(ssh
, SSH2_OPEN_CONNECT_FAILED
);
5909 ssh2_pkt_addstring(ssh
, error
);
5910 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5914 c
->localid
= alloc_channel_id(ssh
);
5916 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5917 c
->v
.v2
.remwindow
= winsize
;
5918 c
->v
.v2
.remmaxpkt
= pktsize
;
5919 bufchain_init(&c
->v
.v2
.outbuffer
);
5920 add234(ssh
->channels
, c
);
5921 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
5922 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5923 ssh2_pkt_adduint32(ssh
, c
->localid
);
5924 ssh2_pkt_adduint32(ssh
, c
->v
.v2
.locwindow
);
5925 ssh2_pkt_adduint32(ssh
, 0x4000UL
); /* our max pkt size */
5929 bombout(("Strange packet received: type %d", ssh
->pktin
.type
));
5934 * We have spare data. Add it to the channel buffer.
5936 ssh2_add_channel_data(ssh
->mainchan
, (char *)in
, inlen
);
5941 struct ssh_channel
*c
;
5943 * Try to send data on all channels if we can.
5945 for (i
= 0; NULL
!= (c
= index234(ssh
->channels
, i
)); i
++) {
5948 continue; /* don't send on closing channels */
5949 bufsize
= ssh2_try_send(c
);
5952 case CHAN_MAINSESSION
:
5953 /* stdin need not receive an unthrottle
5954 * notification since it will be polled */
5957 x11_unthrottle(c
->u
.x11
.s
);
5960 /* agent sockets are request/response and need no
5961 * buffer management */
5964 pfd_unthrottle(c
->u
.pfd
.s
);
5976 * Handle the top-level SSH2 protocol.
5978 static void ssh2_protocol(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
5980 if (do_ssh2_transport(ssh
, in
, inlen
, ispkt
) == 0)
5982 do_ssh2_authconn(ssh
, in
, inlen
, ispkt
);
5986 * Called to set up the connection.
5988 * Returns an error message, or NULL on success.
5990 static char *ssh_init(void *frontend_handle
, void **backend_handle
,
5992 char *host
, int port
, char **realhost
, int nodelay
)
5997 ssh
= snew(struct ssh_tag
);
5998 ssh
->cfg
= *cfg
; /* STRUCTURE COPY */
5999 ssh
->version
= 0; /* when not ready yet */
6002 ssh
->v1_cipher_ctx
= NULL
;
6003 ssh
->crcda_ctx
= NULL
;
6004 ssh
->cscipher
= NULL
;
6005 ssh
->cs_cipher_ctx
= NULL
;
6006 ssh
->sccipher
= NULL
;
6007 ssh
->sc_cipher_ctx
= NULL
;
6009 ssh
->cs_mac_ctx
= NULL
;
6011 ssh
->sc_mac_ctx
= NULL
;
6013 ssh
->cs_comp_ctx
= NULL
;
6015 ssh
->sc_comp_ctx
= NULL
;
6017 ssh
->kex_ctx
= NULL
;
6018 ssh
->hostkey
= NULL
;
6020 ssh
->state
= SSH_STATE_PREPACKET
;
6021 ssh
->size_needed
= FALSE
;
6022 ssh
->eof_needed
= FALSE
;
6026 static const struct Packet empty
= { 0, 0, NULL
, NULL
, 0 };
6027 ssh
->pktin
= ssh
->pktout
= empty
;
6029 ssh
->deferred_send_data
= NULL
;
6030 ssh
->deferred_len
= 0;
6031 ssh
->deferred_size
= 0;
6032 ssh
->fallback_cmd
= 0;
6034 ssh
->x11auth
= NULL
;
6035 ssh
->v1_compressing
= FALSE
;
6036 ssh
->v2_outgoing_sequence
= 0;
6037 ssh
->ssh1_rdpkt_crstate
= 0;
6038 ssh
->ssh2_rdpkt_crstate
= 0;
6039 ssh
->do_ssh_init_crstate
= 0;
6040 ssh
->ssh_gotdata_crstate
= 0;
6041 ssh
->ssh1_protocol_crstate
= 0;
6042 ssh
->do_ssh1_login_crstate
= 0;
6043 ssh
->do_ssh2_transport_crstate
= 0;
6044 ssh
->do_ssh2_authconn_crstate
= 0;
6045 ssh
->do_ssh_init_state
= NULL
;
6046 ssh
->do_ssh1_login_state
= NULL
;
6047 ssh
->do_ssh2_transport_state
= NULL
;
6048 ssh
->do_ssh2_authconn_state
= NULL
;
6049 ssh
->mainchan
= NULL
;
6050 ssh
->throttled_all
= 0;
6051 ssh
->v1_stdout_throttling
= 0;
6053 *backend_handle
= ssh
;
6056 if (crypto_startup() == 0)
6057 return "Microsoft high encryption pack not installed!";
6060 ssh
->frontend
= frontend_handle
;
6061 ssh
->term_width
= ssh
->cfg
.width
;
6062 ssh
->term_height
= ssh
->cfg
.height
;
6064 ssh
->channels
= NULL
;
6065 ssh
->rportfwds
= NULL
;
6070 ssh
->v1_throttle_count
= 0;
6071 ssh
->overall_bufsize
= 0;
6072 ssh
->fallback_cmd
= 0;
6074 ssh
->protocol
= NULL
;
6076 p
= connect_to_host(ssh
, host
, port
, realhost
, nodelay
);
6083 static void ssh_free(void *handle
)
6085 Ssh ssh
= (Ssh
) handle
;
6086 struct ssh_channel
*c
;
6087 struct ssh_rportfwd
*pf
;
6089 if (ssh
->v1_cipher_ctx
)
6090 ssh
->cipher
->free_context(ssh
->v1_cipher_ctx
);
6091 if (ssh
->cs_cipher_ctx
)
6092 ssh
->cscipher
->free_context(ssh
->cs_cipher_ctx
);
6093 if (ssh
->sc_cipher_ctx
)
6094 ssh
->sccipher
->free_context(ssh
->sc_cipher_ctx
);
6095 if (ssh
->cs_mac_ctx
)
6096 ssh
->csmac
->free_context(ssh
->cs_mac_ctx
);
6097 if (ssh
->sc_mac_ctx
)
6098 ssh
->scmac
->free_context(ssh
->sc_mac_ctx
);
6099 if (ssh
->cs_comp_ctx
)
6100 ssh
->cscomp
->compress_cleanup(ssh
->cs_comp_ctx
);
6101 if (ssh
->sc_comp_ctx
)
6102 ssh
->sccomp
->compress_cleanup(ssh
->sc_comp_ctx
);
6104 dh_cleanup(ssh
->kex_ctx
);
6105 sfree(ssh
->savedhost
);
6107 if (ssh
->channels
) {
6108 while ((c
= delpos234(ssh
->channels
, 0)) != NULL
) {
6111 if (c
->u
.x11
.s
!= NULL
)
6112 x11_close(c
->u
.x11
.s
);
6115 if (c
->u
.pfd
.s
!= NULL
)
6116 pfd_close(c
->u
.pfd
.s
);
6121 freetree234(ssh
->channels
);
6124 if (ssh
->rportfwds
) {
6125 while ((pf
= delpos234(ssh
->rportfwds
, 0)) != NULL
)
6127 freetree234(ssh
->rportfwds
);
6129 sfree(ssh
->deferred_send_data
);
6131 x11_free_auth(ssh
->x11auth
);
6132 sfree(ssh
->do_ssh_init_state
);
6133 sfree(ssh
->do_ssh1_login_state
);
6134 sfree(ssh
->do_ssh2_transport_state
);
6135 sfree(ssh
->do_ssh2_authconn_state
);
6143 * Reconfigure the SSH backend.
6145 * Currently, this function does nothing very useful. In future,
6146 * however, we could do some handy things with it. For example, we
6147 * could make the port forwarding configurer active in the Change
6148 * Settings box, and this routine could close down existing
6149 * forwardings and open up new ones in response to changes.
6151 static void ssh_reconfig(void *handle
, Config
*cfg
)
6153 Ssh ssh
= (Ssh
) handle
;
6154 ssh
->cfg
= *cfg
; /* STRUCTURE COPY */
6158 * Called to send data down the Telnet connection.
6160 static int ssh_send(void *handle
, char *buf
, int len
)
6162 Ssh ssh
= (Ssh
) handle
;
6164 if (ssh
== NULL
|| ssh
->s
== NULL
|| ssh
->protocol
== NULL
)
6167 ssh
->protocol(ssh
, (unsigned char *)buf
, len
, 0);
6169 return ssh_sendbuffer(ssh
);
6173 * Called to query the current amount of buffered stdin data.
6175 static int ssh_sendbuffer(void *handle
)
6177 Ssh ssh
= (Ssh
) handle
;
6180 if (ssh
== NULL
|| ssh
->s
== NULL
|| ssh
->protocol
== NULL
)
6184 * If the SSH socket itself has backed up, add the total backup
6185 * size on that to any individual buffer on the stdin channel.
6188 if (ssh
->throttled_all
)
6189 override_value
= ssh
->overall_bufsize
;
6191 if (ssh
->version
== 1) {
6192 return override_value
;
6193 } else if (ssh
->version
== 2) {
6194 if (!ssh
->mainchan
|| ssh
->mainchan
->closes
> 0)
6195 return override_value
;
6197 return (override_value
+
6198 bufchain_size(&ssh
->mainchan
->v
.v2
.outbuffer
));
6205 * Called to set the size of the window from SSH's POV.
6207 static void ssh_size(void *handle
, int width
, int height
)
6209 Ssh ssh
= (Ssh
) handle
;
6211 ssh
->term_width
= width
;
6212 ssh
->term_height
= height
;
6214 switch (ssh
->state
) {
6215 case SSH_STATE_BEFORE_SIZE
:
6216 case SSH_STATE_PREPACKET
:
6217 case SSH_STATE_CLOSED
:
6218 break; /* do nothing */
6219 case SSH_STATE_INTERMED
:
6220 ssh
->size_needed
= TRUE
; /* buffer for later */
6222 case SSH_STATE_SESSION
:
6223 if (!ssh
->cfg
.nopty
) {
6224 if (ssh
->version
== 1) {
6225 send_packet(ssh
, SSH1_CMSG_WINDOW_SIZE
,
6226 PKT_INT
, ssh
->term_height
,
6227 PKT_INT
, ssh
->term_width
,
6228 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
6230 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
6231 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
6232 ssh2_pkt_addstring(ssh
, "window-change");
6233 ssh2_pkt_addbool(ssh
, 0);
6234 ssh2_pkt_adduint32(ssh
, ssh
->term_width
);
6235 ssh2_pkt_adduint32(ssh
, ssh
->term_height
);
6236 ssh2_pkt_adduint32(ssh
, 0);
6237 ssh2_pkt_adduint32(ssh
, 0);
6246 * Return a list of the special codes that make sense in this
6249 static const struct telnet_special
*ssh_get_specials(void *handle
)
6251 Ssh ssh
= (Ssh
) handle
;
6253 if (ssh
->version
== 1) {
6254 static const struct telnet_special ssh1_specials
[] = {
6255 {"IGNORE message", TS_NOP
},
6258 return ssh1_specials
;
6259 } else if (ssh
->version
== 2) {
6260 static const struct telnet_special ssh2_specials
[] = {
6262 {"IGNORE message", TS_NOP
},
6265 return ssh2_specials
;
6271 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6272 * can send an EOF and collect resulting output (e.g. `plink
6275 static void ssh_special(void *handle
, Telnet_Special code
)
6277 Ssh ssh
= (Ssh
) handle
;
6279 if (code
== TS_EOF
) {
6280 if (ssh
->state
!= SSH_STATE_SESSION
) {
6282 * Buffer the EOF in case we are pre-SESSION, so we can
6283 * send it as soon as we reach SESSION.
6286 ssh
->eof_needed
= TRUE
;
6289 if (ssh
->version
== 1) {
6290 send_packet(ssh
, SSH1_CMSG_EOF
, PKT_END
);
6292 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_EOF
);
6293 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
6296 logevent("Sent EOF message");
6297 } else if (code
== TS_PING
|| code
== TS_NOP
) {
6298 if (ssh
->state
== SSH_STATE_CLOSED
6299 || ssh
->state
== SSH_STATE_PREPACKET
) return;
6300 if (ssh
->version
== 1) {
6301 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
))
6302 send_packet(ssh
, SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
6304 ssh2_pkt_init(ssh
, SSH2_MSG_IGNORE
);
6305 ssh2_pkt_addstring_start(ssh
);
6308 } else if (code
== TS_BRK
) {
6309 if (ssh
->state
== SSH_STATE_CLOSED
6310 || ssh
->state
== SSH_STATE_PREPACKET
) return;
6311 if (ssh
->version
== 1) {
6312 logevent("Unable to send BREAK signal in SSH1");
6314 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
6315 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
6316 ssh2_pkt_addstring(ssh
, "break");
6317 ssh2_pkt_addbool(ssh
, 0);
6318 ssh2_pkt_adduint32(ssh
, 0); /* default break length */
6326 void *new_sock_channel(void *handle
, Socket s
)
6328 Ssh ssh
= (Ssh
) handle
;
6329 struct ssh_channel
*c
;
6330 c
= snew(struct ssh_channel
);
6334 c
->remoteid
= -1; /* to be set when open confirmed */
6335 c
->localid
= alloc_channel_id(ssh
);
6337 c
->type
= CHAN_SOCKDATA_DORMANT
;/* identify channel type */
6339 bufchain_init(&c
->v
.v2
.outbuffer
);
6340 add234(ssh
->channels
, c
);
6346 * This is called when stdout/stderr (the entity to which
6347 * from_backend sends data) manages to clear some backlog.
6349 static void ssh_unthrottle(void *handle
, int bufsize
)
6351 Ssh ssh
= (Ssh
) handle
;
6352 if (ssh
->version
== 1) {
6353 if (ssh
->v1_stdout_throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
6354 ssh
->v1_stdout_throttling
= 0;
6355 ssh1_throttle(ssh
, -1);
6358 if (ssh
->mainchan
&& ssh
->mainchan
->closes
== 0)
6359 ssh2_set_window(ssh
->mainchan
, OUR_V2_WINSIZE
- bufsize
);
6363 void ssh_send_port_open(void *channel
, char *hostname
, int port
, char *org
)
6365 struct ssh_channel
*c
= (struct ssh_channel
*)channel
;
6368 logeventf(ssh
, "Opening forwarded connection to %s:%d", hostname
, port
);
6370 if (ssh
->version
== 1) {
6371 send_packet(ssh
, SSH1_MSG_PORT_OPEN
,
6372 PKT_INT
, c
->localid
,
6375 //PKT_STR, <org:orgport>,
6378 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN
);
6379 ssh2_pkt_addstring(ssh
, "direct-tcpip");
6380 ssh2_pkt_adduint32(ssh
, c
->localid
);
6381 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
6382 ssh2_pkt_adduint32(ssh
, c
->v
.v2
.locwindow
);/* our window size */
6383 ssh2_pkt_adduint32(ssh
, 0x4000UL
); /* our max pkt size */
6384 ssh2_pkt_addstring(ssh
, hostname
);
6385 ssh2_pkt_adduint32(ssh
, port
);
6387 * We make up values for the originator data; partly it's
6388 * too much hassle to keep track, and partly I'm not
6389 * convinced the server should be told details like that
6390 * about my local network configuration.
6392 ssh2_pkt_addstring(ssh
, "client-side-connection");
6393 ssh2_pkt_adduint32(ssh
, 0);
6399 static Socket
ssh_socket(void *handle
)
6401 Ssh ssh
= (Ssh
) handle
;
6405 static int ssh_sendok(void *handle
)
6407 Ssh ssh
= (Ssh
) handle
;
6408 return ssh
->send_ok
;
6411 static int ssh_ldisc(void *handle
, int option
)
6413 Ssh ssh
= (Ssh
) handle
;
6414 if (option
== LD_ECHO
)
6415 return ssh
->echoing
;
6416 if (option
== LD_EDIT
)
6417 return ssh
->editing
;
6421 static void ssh_provide_ldisc(void *handle
, void *ldisc
)
6423 Ssh ssh
= (Ssh
) handle
;
6427 static void ssh_provide_logctx(void *handle
, void *logctx
)
6429 Ssh ssh
= (Ssh
) handle
;
6430 ssh
->logctx
= logctx
;
6433 static int ssh_return_exitcode(void *handle
)
6435 Ssh ssh
= (Ssh
) handle
;
6439 return (ssh
->exitcode
>= 0 ? ssh
->exitcode
: 0);
6443 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6444 * that fails. This variable is the means by which scp.c can reach
6445 * into the SSH code and find out which one it got.
6447 extern int ssh_fallback_cmd(void *handle
)
6449 Ssh ssh
= (Ssh
) handle
;
6450 return ssh
->fallback_cmd
;
6453 Backend ssh_backend
= {
6463 ssh_return_exitcode
,