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
);
325 static int do_ssh1_login(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
);
326 static void do_ssh2_authconn(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
);
329 * Buffer management constants. There are several of these for
330 * various different purposes:
332 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
333 * on a local data stream before we throttle the whole SSH
334 * connection (in SSH1 only). Throttling the whole connection is
335 * pretty drastic so we set this high in the hope it won't
338 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
339 * on the SSH connection itself before we defensively throttle
340 * _all_ local data streams. This is pretty drastic too (though
341 * thankfully unlikely in SSH2 since the window mechanism should
342 * ensure that the server never has any need to throttle its end
343 * of the connection), so we set this high as well.
345 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
349 #define SSH1_BUFFER_LIMIT 32768
350 #define SSH_MAX_BACKLOG 32768
351 #define OUR_V2_WINSIZE 16384
353 const static struct ssh_kex
*kex_algs
[] = {
354 &ssh_diffiehellman_gex
,
358 const static struct ssh_signkey
*hostkey_algs
[] = { &ssh_rsa
, &ssh_dss
};
360 static void *nullmac_make_context(void)
364 static void nullmac_free_context(void *handle
)
367 static void nullmac_key(void *handle
, unsigned char *key
)
370 static void nullmac_generate(void *handle
, unsigned char *blk
, int len
,
374 static int nullmac_verify(void *handle
, unsigned char *blk
, int len
,
379 const static struct ssh_mac ssh_mac_none
= {
380 nullmac_make_context
, nullmac_free_context
, nullmac_key
,
381 nullmac_generate
, nullmac_verify
, "none", 0
383 const static struct ssh_mac
*macs
[] = {
384 &ssh_sha1
, &ssh_md5
, &ssh_mac_none
386 const static struct ssh_mac
*buggymacs
[] = {
387 &ssh_sha1_buggy
, &ssh_md5
, &ssh_mac_none
390 static void *ssh_comp_none_init(void)
394 static void ssh_comp_none_cleanup(void *handle
)
397 static int ssh_comp_none_block(void *handle
, unsigned char *block
, int len
,
398 unsigned char **outblock
, int *outlen
)
402 static int ssh_comp_none_disable(void *handle
)
406 const static struct ssh_compress ssh_comp_none
= {
408 ssh_comp_none_init
, ssh_comp_none_cleanup
, ssh_comp_none_block
,
409 ssh_comp_none_init
, ssh_comp_none_cleanup
, ssh_comp_none_block
,
410 ssh_comp_none_disable
, NULL
412 extern const struct ssh_compress ssh_zlib
;
413 const static struct ssh_compress
*compressions
[] = {
414 &ssh_zlib
, &ssh_comp_none
417 enum { /* channel types */
422 CHAN_SOCKDATA_DORMANT
/* one the remote hasn't confirmed */
426 * 2-3-4 tree storing channels.
429 Ssh ssh
; /* pointer back to main context */
430 unsigned remoteid
, localid
;
433 * In SSH1, this value contains four bits:
435 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
436 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
437 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
438 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
440 * A channel is completely finished with when all four bits are set.
444 struct ssh1_data_channel
{
447 struct ssh2_data_channel
{
449 unsigned remwindow
, remmaxpkt
;
454 struct ssh_agent_channel
{
455 unsigned char *message
;
456 unsigned char msglen
[4];
457 int lensofar
, totallen
;
459 struct ssh_x11_channel
{
462 struct ssh_pfd_channel
{
469 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
470 * 2 use this structure in different ways, reflecting SSH 2's
471 * altogether saner approach to port forwarding.
473 * In SSH 1, you arrange a remote forwarding by sending the server
474 * the remote port number, and the local destination host:port.
475 * When a connection comes in, the server sends you back that
476 * host:port pair, and you connect to it. This is a ready-made
477 * security hole if you're not on the ball: a malicious server
478 * could send you back _any_ host:port pair, so if you trustingly
479 * connect to the address it gives you then you've just opened the
480 * entire inside of your corporate network just by connecting
481 * through it to a dodgy SSH server. Hence, we must store a list of
482 * host:port pairs we _are_ trying to forward to, and reject a
483 * connection request from the server if it's not in the list.
485 * In SSH 2, each side of the connection minds its own business and
486 * doesn't send unnecessary information to the other. You arrange a
487 * remote forwarding by sending the server just the remote port
488 * number. When a connection comes in, the server tells you which
489 * of its ports was connected to; and _you_ have to remember what
490 * local host:port pair went with that port number.
492 * Hence: in SSH 1 this structure stores host:port pairs we intend
493 * to allow connections to, and is indexed by those host:port
494 * pairs. In SSH 2 it stores a mapping from source port to
495 * destination host:port pair, and is indexed by source port.
497 struct ssh_rportfwd
{
498 unsigned sport
, dport
;
511 static void ssh1_protocol(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
);
512 static void ssh2_protocol(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
);
513 static void ssh_size(void *handle
, int width
, int height
);
514 static void ssh_special(void *handle
, Telnet_Special
);
515 static int ssh2_try_send(struct ssh_channel
*c
);
516 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
, int len
);
517 static void ssh_throttle_all(Ssh ssh
, int enable
, int bufsize
);
518 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
);
519 static int ssh_sendbuffer(void *handle
);
520 static void ssh_do_close(Ssh ssh
);
522 struct rdpkt1_state_tag
{
523 long len
, pad
, biglen
, to_read
;
524 unsigned long realcrc
, gotcrc
;
530 struct rdpkt2_state_tag
{
531 long len
, pad
, payload
, packetlen
, maclen
;
534 unsigned long incoming_sequence
;
538 const struct plug_function_table
*fn
;
539 /* the above field _must_ be first in the structure */
541 SHA_State exhash
, exhashbase
;
548 unsigned char session_key
[32];
550 int v1_remote_protoflags
;
551 int v1_local_protoflags
;
552 int agentfwd_enabled
;
555 const struct ssh_cipher
*cipher
;
558 const struct ssh2_cipher
*cscipher
, *sccipher
;
559 void *cs_cipher_ctx
, *sc_cipher_ctx
;
560 const struct ssh_mac
*csmac
, *scmac
;
561 void *cs_mac_ctx
, *sc_mac_ctx
;
562 const struct ssh_compress
*cscomp
, *sccomp
;
563 void *cs_comp_ctx
, *sc_comp_ctx
;
564 const struct ssh_kex
*kex
;
565 const struct ssh_signkey
*hostkey
;
566 unsigned char v2_session_id
[20];
572 int echoing
, editing
;
576 int term_width
, term_height
;
578 tree234
*channels
; /* indexed by local id */
579 struct ssh_channel
*mainchan
; /* primary session channel */
586 SSH_STATE_BEFORE_SIZE
,
592 int size_needed
, eof_needed
;
595 struct Packet pktout
;
596 unsigned char *deferred_send_data
;
597 int deferred_len
, deferred_size
;
600 * Gross hack: pscp will try to start SFTP but fall back to
601 * scp1 if that fails. This variable is the means by which
602 * scp.c can reach into the SSH code and find out which one it
608 * Used for username and password input.
610 char *userpass_input_buffer
;
611 int userpass_input_buflen
;
612 int userpass_input_bufpos
;
613 int userpass_input_echo
;
615 char *portfwd_strptr
;
621 int v1_throttle_count
;
624 int v1_stdout_throttling
;
625 int v2_outgoing_sequence
;
627 int ssh1_rdpkt_crstate
;
628 int ssh2_rdpkt_crstate
;
629 int do_ssh_init_crstate
;
630 int ssh_gotdata_crstate
;
631 int ssh1_protocol_crstate
;
632 int do_ssh1_login_crstate
;
633 int do_ssh2_transport_crstate
;
634 int do_ssh2_authconn_crstate
;
636 void *do_ssh_init_state
;
637 void *do_ssh1_login_state
;
638 void *do_ssh2_transport_state
;
639 void *do_ssh2_authconn_state
;
641 struct rdpkt1_state_tag rdpkt1_state
;
642 struct rdpkt2_state_tag rdpkt2_state
;
644 void (*protocol
) (Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
);
645 int (*s_rdpkt
) (Ssh ssh
, unsigned char **data
, int *datalen
);
648 * We maintain a full _copy_ of a Config structure here, not
649 * merely a pointer to it. That way, when we're passed a new
650 * one for reconfiguration, we can check the differences and
651 * potentially reconfigure port forwardings etc in mid-session.
656 * Used to transfer data back from async agent callbacks.
658 void *agent_response
;
659 int agent_response_len
;
662 #define logevent(s) logevent(ssh->frontend, s)
664 /* logevent, only printf-formatted. */
665 static void logeventf(Ssh ssh
, const char *fmt
, ...)
671 buf
= dupvprintf(fmt
, ap
);
677 #define bombout(msg) \
679 char *text = dupprintf msg; \
682 connection_fatal(ssh->frontend, "%s", text); \
686 static int ssh_channelcmp(void *av
, void *bv
)
688 struct ssh_channel
*a
= (struct ssh_channel
*) av
;
689 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
690 if (a
->localid
< b
->localid
)
692 if (a
->localid
> b
->localid
)
696 static int ssh_channelfind(void *av
, void *bv
)
698 unsigned *a
= (unsigned *) av
;
699 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
707 static int ssh_rportcmp_ssh1(void *av
, void *bv
)
709 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
710 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
712 if ( (i
= strcmp(a
->dhost
, b
->dhost
)) != 0)
713 return i
< 0 ?
-1 : +1;
714 if (a
->dport
> b
->dport
)
716 if (a
->dport
< b
->dport
)
721 static int ssh_rportcmp_ssh2(void *av
, void *bv
)
723 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
724 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
726 if (a
->sport
> b
->sport
)
728 if (a
->sport
< b
->sport
)
733 static int alloc_channel_id(Ssh ssh
)
735 const unsigned CHANNEL_NUMBER_OFFSET
= 256;
736 unsigned low
, high
, mid
;
738 struct ssh_channel
*c
;
741 * First-fit allocation of channel numbers: always pick the
742 * lowest unused one. To do this, binary-search using the
743 * counted B-tree to find the largest channel ID which is in a
744 * contiguous sequence from the beginning. (Precisely
745 * everything in that sequence must have ID equal to its tree
746 * index plus CHANNEL_NUMBER_OFFSET.)
748 tsize
= count234(ssh
->channels
);
752 while (high
- low
> 1) {
753 mid
= (high
+ low
) / 2;
754 c
= index234(ssh
->channels
, mid
);
755 if (c
->localid
== mid
+ CHANNEL_NUMBER_OFFSET
)
756 low
= mid
; /* this one is fine */
758 high
= mid
; /* this one is past it */
761 * Now low points to either -1, or the tree index of the
762 * largest ID in the initial sequence.
765 unsigned i
= low
+ 1 + CHANNEL_NUMBER_OFFSET
;
766 assert(NULL
== find234(ssh
->channels
, &i
, ssh_channelfind
));
768 return low
+ 1 + CHANNEL_NUMBER_OFFSET
;
771 static void c_write(Ssh ssh
, const char *buf
, int len
)
773 if ((flags
& FLAG_STDERR
)) {
775 for (i
= 0; i
< len
; i
++)
777 fputc(buf
[i
], stderr
);
780 from_backend(ssh
->frontend
, 1, buf
, len
);
783 static void c_write_untrusted(Ssh ssh
, const char *buf
, int len
)
786 for (i
= 0; i
< len
; i
++) {
788 c_write(ssh
, "\r\n", 2);
789 else if ((buf
[i
] & 0x60) || (buf
[i
] == '\r'))
790 c_write(ssh
, buf
+ i
, 1);
794 static void c_write_str(Ssh ssh
, const char *buf
)
796 c_write(ssh
, buf
, strlen(buf
));
800 * Collect incoming data in the incoming packet buffer.
801 * Decipher and verify the packet when it is completely read.
802 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
803 * Update the *data and *datalen variables.
804 * Return the additional nr of bytes needed, or 0 when
805 * a complete packet is available.
807 static int ssh1_rdpkt(Ssh ssh
, unsigned char **data
, int *datalen
)
809 struct rdpkt1_state_tag
*st
= &ssh
->rdpkt1_state
;
811 crBegin(ssh
->ssh1_rdpkt_crstate
);
816 ssh
->pktin
.length
= 0;
818 for (st
->i
= st
->len
= 0; st
->i
< 4; st
->i
++) {
819 while ((*datalen
) == 0)
821 st
->len
= (st
->len
<< 8) + **data
;
822 (*data
)++, (*datalen
)--;
825 st
->pad
= 8 - (st
->len
% 8);
826 st
->biglen
= st
->len
+ st
->pad
;
827 ssh
->pktin
.length
= st
->len
- 5;
829 if (ssh
->pktin
.maxlen
< st
->biglen
) {
830 ssh
->pktin
.maxlen
= st
->biglen
;
831 ssh
->pktin
.data
= sresize(ssh
->pktin
.data
, st
->biglen
+ APIEXTRA
,
835 st
->to_read
= st
->biglen
;
836 st
->p
= ssh
->pktin
.data
;
837 while (st
->to_read
> 0) {
838 st
->chunk
= st
->to_read
;
839 while ((*datalen
) == 0)
840 crReturn(st
->to_read
);
841 if (st
->chunk
> (*datalen
))
842 st
->chunk
= (*datalen
);
843 memcpy(st
->p
, *data
, st
->chunk
);
845 *datalen
-= st
->chunk
;
847 st
->to_read
-= st
->chunk
;
850 if (ssh
->cipher
&& detect_attack(ssh
->crcda_ctx
, ssh
->pktin
.data
,
852 bombout(("Network attack (CRC compensation) detected!"));
857 ssh
->cipher
->decrypt(ssh
->v1_cipher_ctx
, ssh
->pktin
.data
, st
->biglen
);
859 st
->realcrc
= crc32(ssh
->pktin
.data
, st
->biglen
- 4);
860 st
->gotcrc
= GET_32BIT(ssh
->pktin
.data
+ st
->biglen
- 4);
861 if (st
->gotcrc
!= st
->realcrc
) {
862 bombout(("Incorrect CRC received on packet"));
866 ssh
->pktin
.body
= ssh
->pktin
.data
+ st
->pad
+ 1;
868 if (ssh
->v1_compressing
) {
869 unsigned char *decompblk
;
871 zlib_decompress_block(ssh
->sc_comp_ctx
,
872 ssh
->pktin
.body
- 1, ssh
->pktin
.length
+ 1,
873 &decompblk
, &decomplen
);
875 if (ssh
->pktin
.maxlen
< st
->pad
+ decomplen
) {
876 ssh
->pktin
.maxlen
= st
->pad
+ decomplen
;
877 ssh
->pktin
.data
= sresize(ssh
->pktin
.data
,
878 ssh
->pktin
.maxlen
+ APIEXTRA
,
880 ssh
->pktin
.body
= ssh
->pktin
.data
+ st
->pad
+ 1;
883 memcpy(ssh
->pktin
.body
- 1, decompblk
, decomplen
);
885 ssh
->pktin
.length
= decomplen
- 1;
888 ssh
->pktin
.type
= ssh
->pktin
.body
[-1];
891 log_packet(ssh
->logctx
,
892 PKT_INCOMING
, ssh
->pktin
.type
,
893 ssh1_pkt_type(ssh
->pktin
.type
),
894 ssh
->pktin
.body
, ssh
->pktin
.length
);
896 if (ssh
->pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
897 ssh
->pktin
.type
== SSH1_SMSG_STDERR_DATA
||
898 ssh
->pktin
.type
== SSH1_MSG_DEBUG
||
899 ssh
->pktin
.type
== SSH1_SMSG_AUTH_TIS_CHALLENGE
||
900 ssh
->pktin
.type
== SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
901 long stringlen
= GET_32BIT(ssh
->pktin
.body
);
902 if (stringlen
+ 4 != ssh
->pktin
.length
) {
903 bombout(("Received data packet with bogus string length"));
908 if (ssh
->pktin
.type
== SSH1_MSG_DEBUG
) {
909 /* log debug message */
911 int stringlen
= GET_32BIT(ssh
->pktin
.body
);
912 strcpy(buf
, "Remote debug message: ");
915 memcpy(buf
+ 8, ssh
->pktin
.body
+ 4, stringlen
);
916 buf
[8 + stringlen
] = '\0';
919 } else if (ssh
->pktin
.type
== SSH1_MSG_IGNORE
) {
924 if (ssh
->pktin
.type
== SSH1_MSG_DISCONNECT
) {
925 /* log reason code in disconnect message */
927 unsigned msglen
= GET_32BIT(ssh
->pktin
.body
);
929 strcpy(buf
, "Remote sent disconnect: ");
930 nowlen
= strlen(buf
);
931 if (msglen
> sizeof(buf
) - nowlen
- 1)
932 msglen
= sizeof(buf
) - nowlen
- 1;
933 memcpy(buf
+ nowlen
, ssh
->pktin
.body
+ 4, msglen
);
934 buf
[nowlen
+ msglen
] = '\0';
935 /* logevent(buf); (this is now done within the bombout macro) */
936 bombout(("Server sent disconnect message:\n\"%s\"", buf
+nowlen
));
943 static int ssh2_rdpkt(Ssh ssh
, unsigned char **data
, int *datalen
)
945 struct rdpkt2_state_tag
*st
= &ssh
->rdpkt2_state
;
947 crBegin(ssh
->ssh2_rdpkt_crstate
);
951 ssh
->pktin
.length
= 0;
953 st
->cipherblk
= ssh
->sccipher
->blksize
;
956 if (st
->cipherblk
< 8)
959 if (ssh
->pktin
.maxlen
< st
->cipherblk
) {
960 ssh
->pktin
.maxlen
= st
->cipherblk
;
961 ssh
->pktin
.data
= sresize(ssh
->pktin
.data
, st
->cipherblk
+ APIEXTRA
,
966 * Acquire and decrypt the first block of the packet. This will
967 * contain the length and padding details.
969 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
970 while ((*datalen
) == 0)
971 crReturn(st
->cipherblk
- st
->i
);
972 ssh
->pktin
.data
[st
->i
] = *(*data
)++;
977 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
978 ssh
->pktin
.data
, st
->cipherblk
);
981 * Now get the length and padding figures.
983 st
->len
= GET_32BIT(ssh
->pktin
.data
);
984 st
->pad
= ssh
->pktin
.data
[4];
987 * _Completely_ silly lengths should be stomped on before they
988 * do us any more damage.
990 if (st
->len
< 0 || st
->pad
< 0 || st
->len
+ st
->pad
< 0) {
991 bombout(("Incoming packet was garbled on decryption"));
996 * This enables us to deduce the payload length.
998 st
->payload
= st
->len
- st
->pad
- 1;
1000 ssh
->pktin
.length
= st
->payload
+ 5;
1003 * So now we can work out the total packet length.
1005 st
->packetlen
= st
->len
+ 4;
1006 st
->maclen
= ssh
->scmac ? ssh
->scmac
->len
: 0;
1009 * Adjust memory allocation if packet is too big.
1011 if (ssh
->pktin
.maxlen
< st
->packetlen
+ st
->maclen
) {
1012 ssh
->pktin
.maxlen
= st
->packetlen
+ st
->maclen
;
1013 ssh
->pktin
.data
= sresize(ssh
->pktin
.data
,
1014 ssh
->pktin
.maxlen
+ APIEXTRA
,
1019 * Read and decrypt the remainder of the packet.
1021 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
;
1023 while ((*datalen
) == 0)
1024 crReturn(st
->packetlen
+ st
->maclen
- st
->i
);
1025 ssh
->pktin
.data
[st
->i
] = *(*data
)++;
1028 /* Decrypt everything _except_ the MAC. */
1030 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
1031 ssh
->pktin
.data
+ st
->cipherblk
,
1032 st
->packetlen
- st
->cipherblk
);
1038 && !ssh
->scmac
->verify(ssh
->sc_mac_ctx
, ssh
->pktin
.data
, st
->len
+ 4,
1039 st
->incoming_sequence
)) {
1040 bombout(("Incorrect MAC received on packet"));
1043 st
->incoming_sequence
++; /* whether or not we MACed */
1046 * Decompress packet payload.
1049 unsigned char *newpayload
;
1052 ssh
->sccomp
->decompress(ssh
->sc_comp_ctx
,
1053 ssh
->pktin
.data
+ 5, ssh
->pktin
.length
- 5,
1054 &newpayload
, &newlen
)) {
1055 if (ssh
->pktin
.maxlen
< newlen
+ 5) {
1056 ssh
->pktin
.maxlen
= newlen
+ 5;
1057 ssh
->pktin
.data
= sresize(ssh
->pktin
.data
,
1058 ssh
->pktin
.maxlen
+ APIEXTRA
,
1061 ssh
->pktin
.length
= 5 + newlen
;
1062 memcpy(ssh
->pktin
.data
+ 5, newpayload
, newlen
);
1067 ssh
->pktin
.savedpos
= 6;
1068 ssh
->pktin
.type
= ssh
->pktin
.data
[5];
1071 log_packet(ssh
->logctx
, PKT_INCOMING
, ssh
->pktin
.type
,
1072 ssh2_pkt_type(ssh
->pkt_ctx
, ssh
->pktin
.type
),
1073 ssh
->pktin
.data
+6, ssh
->pktin
.length
-6);
1075 switch (ssh
->pktin
.type
) {
1077 * These packets we must handle instantly.
1079 case SSH2_MSG_DISCONNECT
:
1081 /* log reason code in disconnect message */
1084 int reason
= GET_32BIT(ssh
->pktin
.data
+ 6);
1085 unsigned msglen
= GET_32BIT(ssh
->pktin
.data
+ 10);
1087 if (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) {
1088 buf
= dupprintf("Received disconnect message (%s)",
1089 ssh2_disconnect_reasons
[reason
]);
1091 buf
= dupprintf("Received disconnect message (unknown"
1092 " type %d)", reason
);
1096 buf
= dupprintf("Disconnection message text: %n%.*s",
1097 &nowlen
, msglen
, ssh
->pktin
.data
+ 14);
1099 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1101 (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) ?
1102 ssh2_disconnect_reasons
[reason
] : "unknown",
1108 case SSH2_MSG_IGNORE
:
1110 case SSH2_MSG_DEBUG
:
1112 /* log the debug message */
1114 /* int display = ssh->pktin.body[6]; */
1115 int stringlen
= GET_32BIT(ssh
->pktin
.data
+7);
1117 strcpy(buf
, "Remote debug message: ");
1118 prefix
= strlen(buf
);
1119 if (stringlen
> (int)(sizeof(buf
)-prefix
-1))
1120 stringlen
= sizeof(buf
)-prefix
-1;
1121 memcpy(buf
+ prefix
, ssh
->pktin
.data
+ 11, stringlen
);
1122 buf
[prefix
+ stringlen
] = '\0';
1125 goto next_packet
; /* FIXME: print the debug message */
1128 * These packets we need do nothing about here.
1130 case SSH2_MSG_UNIMPLEMENTED
:
1131 case SSH2_MSG_SERVICE_REQUEST
:
1132 case SSH2_MSG_SERVICE_ACCEPT
:
1133 case SSH2_MSG_KEXINIT
:
1134 case SSH2_MSG_NEWKEYS
:
1135 case SSH2_MSG_KEXDH_INIT
:
1136 case SSH2_MSG_KEXDH_REPLY
:
1137 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1138 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1139 case SSH2_MSG_KEX_DH_GEX_INIT
:
1140 case SSH2_MSG_KEX_DH_GEX_REPLY
:
1141 case SSH2_MSG_USERAUTH_REQUEST
:
1142 case SSH2_MSG_USERAUTH_FAILURE
:
1143 case SSH2_MSG_USERAUTH_SUCCESS
:
1144 case SSH2_MSG_USERAUTH_BANNER
:
1145 case SSH2_MSG_USERAUTH_PK_OK
:
1146 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1147 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1148 case SSH2_MSG_USERAUTH_INFO_RESPONSE
:
1149 case SSH2_MSG_GLOBAL_REQUEST
:
1150 case SSH2_MSG_REQUEST_SUCCESS
:
1151 case SSH2_MSG_REQUEST_FAILURE
:
1152 case SSH2_MSG_CHANNEL_OPEN
:
1153 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
:
1154 case SSH2_MSG_CHANNEL_OPEN_FAILURE
:
1155 case SSH2_MSG_CHANNEL_WINDOW_ADJUST
:
1156 case SSH2_MSG_CHANNEL_DATA
:
1157 case SSH2_MSG_CHANNEL_EXTENDED_DATA
:
1158 case SSH2_MSG_CHANNEL_EOF
:
1159 case SSH2_MSG_CHANNEL_CLOSE
:
1160 case SSH2_MSG_CHANNEL_REQUEST
:
1161 case SSH2_MSG_CHANNEL_SUCCESS
:
1162 case SSH2_MSG_CHANNEL_FAILURE
:
1166 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1169 ssh2_pkt_init(ssh
, SSH2_MSG_UNIMPLEMENTED
);
1170 ssh2_pkt_adduint32(ssh
, st
->incoming_sequence
- 1);
1178 static void ssh1_pktout_size(Ssh ssh
, int len
)
1182 len
+= 5; /* type and CRC */
1183 pad
= 8 - (len
% 8);
1186 ssh
->pktout
.length
= len
- 5;
1187 if (ssh
->pktout
.maxlen
< biglen
) {
1188 ssh
->pktout
.maxlen
= biglen
;
1190 /* Allocate enough buffer space for extra block
1191 * for MS CryptEncrypt() */
1192 ssh
->pktout
.data
= sresize(ssh
->pktout
.data
, biglen
+ 12,
1195 ssh
->pktout
.data
= sresize(ssh
->pktout
.data
, biglen
+ 4,
1199 ssh
->pktout
.body
= ssh
->pktout
.data
+ 4 + pad
+ 1;
1202 static void s_wrpkt_start(Ssh ssh
, int type
, int len
)
1204 ssh1_pktout_size(ssh
, len
);
1205 ssh
->pktout
.type
= type
;
1208 static int s_wrpkt_prepare(Ssh ssh
)
1214 * XXX various versions of SC (including 8.8.4) screw up the
1215 * register allocation in this function and use the same register
1216 * (D6) for len and as a temporary, with predictable results. The
1217 * following sledgehammer prevents this.
1223 ssh
->pktout
.body
[-1] = ssh
->pktout
.type
;
1226 log_packet(ssh
->logctx
, PKT_OUTGOING
, ssh
->pktout
.type
,
1227 ssh1_pkt_type(ssh
->pktout
.type
),
1228 ssh
->pktout
.body
, ssh
->pktout
.length
);
1230 if (ssh
->v1_compressing
) {
1231 unsigned char *compblk
;
1233 zlib_compress_block(ssh
->cs_comp_ctx
,
1234 ssh
->pktout
.body
- 1, ssh
->pktout
.length
+ 1,
1235 &compblk
, &complen
);
1236 ssh1_pktout_size(ssh
, complen
- 1);
1237 memcpy(ssh
->pktout
.body
- 1, compblk
, complen
);
1241 len
= ssh
->pktout
.length
+ 5; /* type and CRC */
1242 pad
= 8 - (len
% 8);
1245 for (i
= 0; i
< pad
; i
++)
1246 ssh
->pktout
.data
[i
+ 4] = random_byte();
1247 crc
= crc32(ssh
->pktout
.data
+ 4, biglen
- 4);
1248 PUT_32BIT(ssh
->pktout
.data
+ biglen
, crc
);
1249 PUT_32BIT(ssh
->pktout
.data
, len
);
1252 ssh
->cipher
->encrypt(ssh
->v1_cipher_ctx
, ssh
->pktout
.data
+ 4, biglen
);
1257 static void s_wrpkt(Ssh ssh
)
1260 len
= s_wrpkt_prepare(ssh
);
1261 backlog
= sk_write(ssh
->s
, (char *)ssh
->pktout
.data
, len
);
1262 if (backlog
> SSH_MAX_BACKLOG
)
1263 ssh_throttle_all(ssh
, 1, backlog
);
1266 static void s_wrpkt_defer(Ssh ssh
)
1269 len
= s_wrpkt_prepare(ssh
);
1270 if (ssh
->deferred_len
+ len
> ssh
->deferred_size
) {
1271 ssh
->deferred_size
= ssh
->deferred_len
+ len
+ 128;
1272 ssh
->deferred_send_data
= sresize(ssh
->deferred_send_data
,
1276 memcpy(ssh
->deferred_send_data
+ ssh
->deferred_len
, ssh
->pktout
.data
, len
);
1277 ssh
->deferred_len
+= len
;
1281 * Construct a packet with the specified contents.
1283 static void construct_packet(Ssh ssh
, int pkttype
, va_list ap1
, va_list ap2
)
1285 unsigned char *p
, *argp
, argchar
;
1286 unsigned long argint
;
1287 int pktlen
, argtype
, arglen
;
1291 while ((argtype
= va_arg(ap1
, int)) != PKT_END
) {
1294 (void) va_arg(ap1
, int);
1298 (void) va_arg(ap1
, int);
1302 (void) va_arg(ap1
, unsigned char *);
1303 arglen
= va_arg(ap1
, int);
1307 argp
= va_arg(ap1
, unsigned char *);
1308 arglen
= strlen((char *)argp
);
1309 pktlen
+= 4 + arglen
;
1312 bn
= va_arg(ap1
, Bignum
);
1313 pktlen
+= ssh1_bignum_length(bn
);
1320 s_wrpkt_start(ssh
, pkttype
, pktlen
);
1321 p
= ssh
->pktout
.body
;
1323 while ((argtype
= va_arg(ap2
, int)) != PKT_END
) {
1326 argint
= va_arg(ap2
, int);
1327 PUT_32BIT(p
, argint
);
1331 argchar
= (unsigned char) va_arg(ap2
, int);
1336 argp
= va_arg(ap2
, unsigned char *);
1337 arglen
= va_arg(ap2
, int);
1338 memcpy(p
, argp
, arglen
);
1342 argp
= va_arg(ap2
, unsigned char *);
1343 arglen
= strlen((char *)argp
);
1344 PUT_32BIT(p
, arglen
);
1345 memcpy(p
+ 4, argp
, arglen
);
1349 bn
= va_arg(ap2
, Bignum
);
1350 p
+= ssh1_write_bignum(p
, bn
);
1356 static void send_packet(Ssh ssh
, int pkttype
, ...)
1359 va_start(ap1
, pkttype
);
1360 va_start(ap2
, pkttype
);
1361 construct_packet(ssh
, pkttype
, ap1
, ap2
);
1365 static void defer_packet(Ssh ssh
, int pkttype
, ...)
1368 va_start(ap1
, pkttype
);
1369 va_start(ap2
, pkttype
);
1370 construct_packet(ssh
, pkttype
, ap1
, ap2
);
1374 static int ssh_versioncmp(char *a
, char *b
)
1377 unsigned long av
, bv
;
1379 av
= strtoul(a
, &ae
, 10);
1380 bv
= strtoul(b
, &be
, 10);
1382 return (av
< bv ?
-1 : +1);
1387 av
= strtoul(ae
, &ae
, 10);
1388 bv
= strtoul(be
, &be
, 10);
1390 return (av
< bv ?
-1 : +1);
1395 * Utility routines for putting an SSH-protocol `string' and
1396 * `uint32' into a SHA state.
1399 static void sha_string(SHA_State
* s
, void *str
, int len
)
1401 unsigned char lenblk
[4];
1402 PUT_32BIT(lenblk
, len
);
1403 SHA_Bytes(s
, lenblk
, 4);
1404 SHA_Bytes(s
, str
, len
);
1407 static void sha_uint32(SHA_State
* s
, unsigned i
)
1409 unsigned char intblk
[4];
1410 PUT_32BIT(intblk
, i
);
1411 SHA_Bytes(s
, intblk
, 4);
1415 * SSH2 packet construction functions.
1417 static void ssh2_pkt_ensure(Ssh ssh
, int length
)
1419 if (ssh
->pktout
.maxlen
< length
) {
1420 ssh
->pktout
.maxlen
= length
+ 256;
1421 ssh
->pktout
.data
= sresize(ssh
->pktout
.data
,
1422 ssh
->pktout
.maxlen
+ APIEXTRA
,
1424 if (!ssh
->pktout
.data
)
1425 fatalbox("Out of memory");
1428 static void ssh2_pkt_adddata(Ssh ssh
, void *data
, int len
)
1430 ssh
->pktout
.length
+= len
;
1431 ssh2_pkt_ensure(ssh
, ssh
->pktout
.length
);
1432 memcpy(ssh
->pktout
.data
+ ssh
->pktout
.length
- len
, data
, len
);
1434 static void ssh2_pkt_addbyte(Ssh ssh
, unsigned char byte
)
1436 ssh2_pkt_adddata(ssh
, &byte
, 1);
1438 static void ssh2_pkt_init(Ssh ssh
, int pkt_type
)
1440 ssh
->pktout
.length
= 5;
1441 ssh2_pkt_addbyte(ssh
, (unsigned char) pkt_type
);
1443 static void ssh2_pkt_addbool(Ssh ssh
, unsigned char value
)
1445 ssh2_pkt_adddata(ssh
, &value
, 1);
1447 static void ssh2_pkt_adduint32(Ssh ssh
, unsigned long value
)
1450 PUT_32BIT(x
, value
);
1451 ssh2_pkt_adddata(ssh
, x
, 4);
1453 static void ssh2_pkt_addstring_start(Ssh ssh
)
1455 ssh2_pkt_adduint32(ssh
, 0);
1456 ssh
->pktout
.savedpos
= ssh
->pktout
.length
;
1458 static void ssh2_pkt_addstring_str(Ssh ssh
, char *data
)
1460 ssh2_pkt_adddata(ssh
, data
, strlen(data
));
1461 PUT_32BIT(ssh
->pktout
.data
+ ssh
->pktout
.savedpos
- 4,
1462 ssh
->pktout
.length
- ssh
->pktout
.savedpos
);
1464 static void ssh2_pkt_addstring_data(Ssh ssh
, char *data
, int len
)
1466 ssh2_pkt_adddata(ssh
, data
, len
);
1467 PUT_32BIT(ssh
->pktout
.data
+ ssh
->pktout
.savedpos
- 4,
1468 ssh
->pktout
.length
- ssh
->pktout
.savedpos
);
1470 static void ssh2_pkt_addstring(Ssh ssh
, char *data
)
1472 ssh2_pkt_addstring_start(ssh
);
1473 ssh2_pkt_addstring_str(ssh
, data
);
1475 static unsigned char *ssh2_mpint_fmt(Bignum b
, int *len
)
1478 int i
, n
= (bignum_bitcount(b
) + 7) / 8;
1479 p
= snewn(n
+ 1, unsigned char);
1481 fatalbox("out of memory");
1483 for (i
= 1; i
<= n
; i
++)
1484 p
[i
] = bignum_byte(b
, n
- i
);
1486 while (i
<= n
&& p
[i
] == 0 && (p
[i
+ 1] & 0x80) == 0)
1488 memmove(p
, p
+ i
, n
+ 1 - i
);
1492 static void ssh2_pkt_addmp(Ssh ssh
, Bignum b
)
1496 p
= ssh2_mpint_fmt(b
, &len
);
1497 ssh2_pkt_addstring_start(ssh
);
1498 ssh2_pkt_addstring_data(ssh
, (char *)p
, len
);
1503 * Construct an SSH2 final-form packet: compress it, encrypt it,
1504 * put the MAC on it. Final packet, ready to be sent, is stored in
1505 * ssh->pktout.data. Total length is returned.
1507 static int ssh2_pkt_construct(Ssh ssh
)
1509 int cipherblk
, maclen
, padding
, i
;
1512 log_packet(ssh
->logctx
, PKT_OUTGOING
, ssh
->pktout
.data
[5],
1513 ssh2_pkt_type(ssh
->pkt_ctx
, ssh
->pktout
.data
[5]),
1514 ssh
->pktout
.data
+ 6, ssh
->pktout
.length
- 6);
1517 * Compress packet payload.
1520 unsigned char *newpayload
;
1523 ssh
->cscomp
->compress(ssh
->cs_comp_ctx
, ssh
->pktout
.data
+ 5,
1524 ssh
->pktout
.length
- 5,
1525 &newpayload
, &newlen
)) {
1526 ssh
->pktout
.length
= 5;
1527 ssh2_pkt_adddata(ssh
, newpayload
, newlen
);
1533 * Add padding. At least four bytes, and must also bring total
1534 * length (minus MAC) up to a multiple of the block size.
1536 cipherblk
= ssh
->cscipher ? ssh
->cscipher
->blksize
: 8; /* block size */
1537 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
1540 (cipherblk
- (ssh
->pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
1541 maclen
= ssh
->csmac ? ssh
->csmac
->len
: 0;
1542 ssh2_pkt_ensure(ssh
, ssh
->pktout
.length
+ padding
+ maclen
);
1543 ssh
->pktout
.data
[4] = padding
;
1544 for (i
= 0; i
< padding
; i
++)
1545 ssh
->pktout
.data
[ssh
->pktout
.length
+ i
] = random_byte();
1546 PUT_32BIT(ssh
->pktout
.data
, ssh
->pktout
.length
+ padding
- 4);
1548 ssh
->csmac
->generate(ssh
->cs_mac_ctx
, ssh
->pktout
.data
,
1549 ssh
->pktout
.length
+ padding
,
1550 ssh
->v2_outgoing_sequence
);
1551 ssh
->v2_outgoing_sequence
++; /* whether or not we MACed */
1554 ssh
->cscipher
->encrypt(ssh
->cs_cipher_ctx
,
1555 ssh
->pktout
.data
, ssh
->pktout
.length
+ padding
);
1557 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1558 return ssh
->pktout
.length
+ padding
+ maclen
;
1562 * Construct and send an SSH2 packet immediately.
1564 static void ssh2_pkt_send(Ssh ssh
)
1568 len
= ssh2_pkt_construct(ssh
);
1569 backlog
= sk_write(ssh
->s
, (char *)ssh
->pktout
.data
, len
);
1570 if (backlog
> SSH_MAX_BACKLOG
)
1571 ssh_throttle_all(ssh
, 1, backlog
);
1575 * Construct an SSH2 packet and add it to a deferred data block.
1576 * Useful for sending multiple packets in a single sk_write() call,
1577 * to prevent a traffic-analysing listener from being able to work
1578 * out the length of any particular packet (such as the password
1581 * Note that because SSH2 sequence-numbers its packets, this can
1582 * NOT be used as an m4-style `defer' allowing packets to be
1583 * constructed in one order and sent in another.
1585 static void ssh2_pkt_defer(Ssh ssh
)
1587 int len
= ssh2_pkt_construct(ssh
);
1588 if (ssh
->deferred_len
+ len
> ssh
->deferred_size
) {
1589 ssh
->deferred_size
= ssh
->deferred_len
+ len
+ 128;
1590 ssh
->deferred_send_data
= sresize(ssh
->deferred_send_data
,
1594 memcpy(ssh
->deferred_send_data
+ ssh
->deferred_len
, ssh
->pktout
.data
, len
);
1595 ssh
->deferred_len
+= len
;
1599 * Send the whole deferred data block constructed by
1600 * ssh2_pkt_defer() or SSH1's defer_packet().
1602 static void ssh_pkt_defersend(Ssh ssh
)
1605 backlog
= sk_write(ssh
->s
, (char *)ssh
->deferred_send_data
,
1607 ssh
->deferred_len
= ssh
->deferred_size
= 0;
1608 sfree(ssh
->deferred_send_data
);
1609 ssh
->deferred_send_data
= NULL
;
1610 if (backlog
> SSH_MAX_BACKLOG
)
1611 ssh_throttle_all(ssh
, 1, backlog
);
1615 void bndebug(char *string
, Bignum b
)
1619 p
= ssh2_mpint_fmt(b
, &len
);
1620 debug(("%s", string
));
1621 for (i
= 0; i
< len
; i
++)
1622 debug((" %02x", p
[i
]));
1628 static void sha_mpint(SHA_State
* s
, Bignum b
)
1632 p
= ssh2_mpint_fmt(b
, &len
);
1633 sha_string(s
, p
, len
);
1638 * SSH2 packet decode functions.
1640 static unsigned long ssh2_pkt_getuint32(Ssh ssh
)
1642 unsigned long value
;
1643 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< 4)
1644 return 0; /* arrgh, no way to decline (FIXME?) */
1645 value
= GET_32BIT(ssh
->pktin
.data
+ ssh
->pktin
.savedpos
);
1646 ssh
->pktin
.savedpos
+= 4;
1649 static int ssh2_pkt_getbool(Ssh ssh
)
1651 unsigned long value
;
1652 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< 1)
1653 return 0; /* arrgh, no way to decline (FIXME?) */
1654 value
= ssh
->pktin
.data
[ssh
->pktin
.savedpos
] != 0;
1655 ssh
->pktin
.savedpos
++;
1658 static void ssh2_pkt_getstring(Ssh ssh
, char **p
, int *length
)
1663 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< 4)
1665 len
= GET_32BIT(ssh
->pktin
.data
+ ssh
->pktin
.savedpos
);
1669 ssh
->pktin
.savedpos
+= 4;
1670 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< *length
)
1672 *p
= (char *)(ssh
->pktin
.data
+ ssh
->pktin
.savedpos
);
1673 ssh
->pktin
.savedpos
+= *length
;
1675 static Bignum
ssh2_pkt_getmp(Ssh ssh
)
1681 ssh2_pkt_getstring(ssh
, &p
, &length
);
1685 bombout(("internal error: Can't handle negative mpints"));
1688 b
= bignum_from_bytes((unsigned char *)p
, length
);
1693 * Helper function to add an SSH2 signature blob to a packet.
1694 * Expects to be shown the public key blob as well as the signature
1695 * blob. Normally works just like ssh2_pkt_addstring, but will
1696 * fiddle with the signature packet if necessary for
1697 * BUG_SSH2_RSA_PADDING.
1699 static void ssh2_add_sigblob(Ssh ssh
, void *pkblob_v
, int pkblob_len
,
1700 void *sigblob_v
, int sigblob_len
)
1702 unsigned char *pkblob
= (unsigned char *)pkblob_v
;
1703 unsigned char *sigblob
= (unsigned char *)sigblob_v
;
1705 /* dmemdump(pkblob, pkblob_len); */
1706 /* dmemdump(sigblob, sigblob_len); */
1709 * See if this is in fact an ssh-rsa signature and a buggy
1710 * server; otherwise we can just do this the easy way.
1712 if ((ssh
->remote_bugs
& BUG_SSH2_RSA_PADDING
) &&
1713 (GET_32BIT(pkblob
) == 7 && !memcmp(pkblob
+4, "ssh-rsa", 7))) {
1714 int pos
, len
, siglen
;
1717 * Find the byte length of the modulus.
1720 pos
= 4+7; /* skip over "ssh-rsa" */
1721 pos
+= 4 + GET_32BIT(pkblob
+pos
); /* skip over exponent */
1722 len
= GET_32BIT(pkblob
+pos
); /* find length of modulus */
1723 pos
+= 4; /* find modulus itself */
1724 while (len
> 0 && pkblob
[pos
] == 0)
1726 /* debug(("modulus length is %d\n", len)); */
1729 * Now find the signature integer.
1731 pos
= 4+7; /* skip over "ssh-rsa" */
1732 siglen
= GET_32BIT(sigblob
+pos
);
1733 /* debug(("signature length is %d\n", siglen)); */
1735 if (len
!= siglen
) {
1736 unsigned char newlen
[4];
1737 ssh2_pkt_addstring_start(ssh
);
1738 ssh2_pkt_addstring_data(ssh
, (char *)sigblob
, pos
);
1739 /* dmemdump(sigblob, pos); */
1740 pos
+= 4; /* point to start of actual sig */
1741 PUT_32BIT(newlen
, len
);
1742 ssh2_pkt_addstring_data(ssh
, (char *)newlen
, 4);
1743 /* dmemdump(newlen, 4); */
1745 while (len
-- > siglen
) {
1746 ssh2_pkt_addstring_data(ssh
, (char *)newlen
, 1);
1747 /* dmemdump(newlen, 1); */
1749 ssh2_pkt_addstring_data(ssh
, (char *)(sigblob
+pos
), siglen
);
1750 /* dmemdump(sigblob+pos, siglen); */
1754 /* Otherwise fall through and do it the easy way. */
1757 ssh2_pkt_addstring_start(ssh
);
1758 ssh2_pkt_addstring_data(ssh
, (char *)sigblob
, sigblob_len
);
1762 * Examine the remote side's version string and compare it against
1763 * a list of known buggy implementations.
1765 static void ssh_detect_bugs(Ssh ssh
, char *vstring
)
1767 char *imp
; /* pointer to implementation part */
1769 imp
+= strcspn(imp
, "-");
1771 imp
+= strcspn(imp
, "-");
1774 ssh
->remote_bugs
= 0;
1776 if (ssh
->cfg
.sshbug_ignore1
== FORCE_ON
||
1777 (ssh
->cfg
.sshbug_ignore1
== AUTO
&&
1778 (!strcmp(imp
, "1.2.18") || !strcmp(imp
, "1.2.19") ||
1779 !strcmp(imp
, "1.2.20") || !strcmp(imp
, "1.2.21") ||
1780 !strcmp(imp
, "1.2.22") || !strcmp(imp
, "Cisco-1.25")))) {
1782 * These versions don't support SSH1_MSG_IGNORE, so we have
1783 * to use a different defence against password length
1786 ssh
->remote_bugs
|= BUG_CHOKES_ON_SSH1_IGNORE
;
1787 logevent("We believe remote version has SSH1 ignore bug");
1790 if (ssh
->cfg
.sshbug_plainpw1
== FORCE_ON
||
1791 (ssh
->cfg
.sshbug_plainpw1
== AUTO
&&
1792 (!strcmp(imp
, "Cisco-1.25")))) {
1794 * These versions need a plain password sent; they can't
1795 * handle having a null and a random length of data after
1798 ssh
->remote_bugs
|= BUG_NEEDS_SSH1_PLAIN_PASSWORD
;
1799 logevent("We believe remote version needs a plain SSH1 password");
1802 if (ssh
->cfg
.sshbug_rsa1
== FORCE_ON
||
1803 (ssh
->cfg
.sshbug_rsa1
== AUTO
&&
1804 (!strcmp(imp
, "Cisco-1.25")))) {
1806 * These versions apparently have no clue whatever about
1807 * RSA authentication and will panic and die if they see
1808 * an AUTH_RSA message.
1810 ssh
->remote_bugs
|= BUG_CHOKES_ON_RSA
;
1811 logevent("We believe remote version can't handle RSA authentication");
1814 if (ssh
->cfg
.sshbug_hmac2
== FORCE_ON
||
1815 (ssh
->cfg
.sshbug_hmac2
== AUTO
&&
1816 (wc_match("2.1.0*", imp
) || wc_match("2.0.*", imp
) ||
1817 wc_match("2.2.0*", imp
) || wc_match("2.3.0*", imp
) ||
1818 wc_match("2.1 *", imp
)))) {
1820 * These versions have the HMAC bug.
1822 ssh
->remote_bugs
|= BUG_SSH2_HMAC
;
1823 logevent("We believe remote version has SSH2 HMAC bug");
1826 if (ssh
->cfg
.sshbug_derivekey2
== FORCE_ON
||
1827 (ssh
->cfg
.sshbug_derivekey2
== AUTO
&&
1828 (wc_match("2.0.0*", imp
) || wc_match("2.0.10*", imp
) ))) {
1830 * These versions have the key-derivation bug (failing to
1831 * include the literal shared secret in the hashes that
1832 * generate the keys).
1834 ssh
->remote_bugs
|= BUG_SSH2_DERIVEKEY
;
1835 logevent("We believe remote version has SSH2 key-derivation bug");
1838 if (ssh
->cfg
.sshbug_rsapad2
== FORCE_ON
||
1839 (ssh
->cfg
.sshbug_rsapad2
== AUTO
&&
1840 (wc_match("OpenSSH_2.[5-9]*", imp
) ||
1841 wc_match("OpenSSH_3.[0-2]*", imp
)))) {
1843 * These versions have the SSH2 RSA padding bug.
1845 ssh
->remote_bugs
|= BUG_SSH2_RSA_PADDING
;
1846 logevent("We believe remote version has SSH2 RSA padding bug");
1849 if (ssh
->cfg
.sshbug_pksessid2
== FORCE_ON
||
1850 (ssh
->cfg
.sshbug_pksessid2
== AUTO
&&
1851 wc_match("OpenSSH_2.[0-2]*", imp
))) {
1853 * These versions have the SSH2 session-ID bug in
1854 * public-key authentication.
1856 ssh
->remote_bugs
|= BUG_SSH2_PK_SESSIONID
;
1857 logevent("We believe remote version has SSH2 public-key-session-ID bug");
1860 if (ssh
->cfg
.sshbug_dhgex2
== FORCE_ON
) {
1862 * User specified the SSH2 DH GEX bug.
1864 ssh
->remote_bugs
|= BUG_SSH2_DH_GEX
;
1865 logevent("We believe remote version has SSH2 DH group exchange bug");
1869 static int do_ssh_init(Ssh ssh
, unsigned char c
)
1871 struct do_ssh_init_state
{
1879 crState(do_ssh_init_state
);
1881 crBegin(ssh
->do_ssh_init_crstate
);
1883 /* Search for the string "SSH-" in the input. */
1886 static const int transS
[] = { 1, 2, 2, 1 };
1887 static const int transH
[] = { 0, 0, 3, 0 };
1888 static const int transminus
[] = { 0, 0, 0, -1 };
1890 s
->i
= transS
[s
->i
];
1892 s
->i
= transH
[s
->i
];
1894 s
->i
= transminus
[s
->i
];
1899 crReturn(1); /* get another character */
1903 s
->vstring
= snewn(s
->vstrsize
, char);
1904 strcpy(s
->vstring
, "SSH-");
1908 crReturn(1); /* get another char */
1909 if (s
->vslen
>= s
->vstrsize
- 1) {
1911 s
->vstring
= sresize(s
->vstring
, s
->vstrsize
, char);
1913 s
->vstring
[s
->vslen
++] = c
;
1916 s
->version
[s
->i
] = '\0';
1918 } else if (s
->i
< sizeof(s
->version
) - 1)
1919 s
->version
[s
->i
++] = c
;
1920 } else if (c
== '\012')
1924 ssh
->agentfwd_enabled
= FALSE
;
1925 ssh
->rdpkt2_state
.incoming_sequence
= 0;
1927 s
->vstring
[s
->vslen
] = 0;
1928 s
->vstring
[strcspn(s
->vstring
, "\r\n")] = '\0';/* remove EOL chars */
1931 vlog
= snewn(20 + s
->vslen
, char);
1932 sprintf(vlog
, "Server version: %s", s
->vstring
);
1936 ssh_detect_bugs(ssh
, s
->vstring
);
1939 * Decide which SSH protocol version to support.
1942 /* Anything strictly below "2.0" means protocol 1 is supported. */
1943 s
->proto1
= ssh_versioncmp(s
->version
, "2.0") < 0;
1944 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
1945 s
->proto2
= ssh_versioncmp(s
->version
, "1.99") >= 0;
1947 if (ssh
->cfg
.sshprot
== 0 && !s
->proto1
) {
1948 bombout(("SSH protocol version 1 required by user but not provided by server"));
1951 if (ssh
->cfg
.sshprot
== 3 && !s
->proto2
) {
1952 bombout(("SSH protocol version 2 required by user but not provided by server"));
1956 if (s
->proto2
&& (ssh
->cfg
.sshprot
>= 2 || !s
->proto1
)) {
1960 char verstring
[80], vlog
[100];
1961 sprintf(verstring
, "SSH-2.0-%s", sshver
);
1962 SHA_Init(&ssh
->exhashbase
);
1964 * Hash our version string and their version string.
1966 sha_string(&ssh
->exhashbase
, verstring
, strlen(verstring
));
1967 sha_string(&ssh
->exhashbase
, s
->vstring
, strcspn(s
->vstring
, "\r\n"));
1968 sprintf(vlog
, "We claim version: %s", verstring
);
1970 strcat(verstring
, "\012");
1971 logevent("Using SSH protocol version 2");
1972 sk_write(ssh
->s
, verstring
, strlen(verstring
));
1973 ssh
->protocol
= ssh2_protocol
;
1975 ssh
->s_rdpkt
= ssh2_rdpkt
;
1980 char verstring
[80], vlog
[100];
1981 sprintf(verstring
, "SSH-%s-%s",
1982 (ssh_versioncmp(s
->version
, "1.5") <= 0 ? s
->version
: "1.5"),
1984 sprintf(vlog
, "We claim version: %s", verstring
);
1986 strcat(verstring
, "\012");
1988 logevent("Using SSH protocol version 1");
1989 sk_write(ssh
->s
, verstring
, strlen(verstring
));
1990 ssh
->protocol
= ssh1_protocol
;
1992 ssh
->s_rdpkt
= ssh1_rdpkt
;
1994 update_specials_menu(ssh
->frontend
);
1995 ssh
->state
= SSH_STATE_BEFORE_SIZE
;
2002 static void ssh_gotdata(Ssh ssh
, unsigned char *data
, int datalen
)
2004 crBegin(ssh
->ssh_gotdata_crstate
);
2007 * To begin with, feed the characters one by one to the
2008 * protocol initialisation / selection function do_ssh_init().
2009 * When that returns 0, we're done with the initial greeting
2010 * exchange and can move on to packet discipline.
2013 int ret
; /* need not be kept across crReturn */
2015 crReturnV
; /* more data please */
2016 ret
= do_ssh_init(ssh
, *data
);
2024 * We emerge from that loop when the initial negotiation is
2025 * over and we have selected an s_rdpkt function. Now pass
2026 * everything to s_rdpkt, and then pass the resulting packets
2027 * to the proper protocol handler.
2032 while (datalen
> 0) {
2033 if (ssh
->s_rdpkt(ssh
, &data
, &datalen
) == 0) {
2034 if (ssh
->state
== SSH_STATE_CLOSED
) {
2037 ssh
->protocol(ssh
, NULL
, 0, 1);
2038 if (ssh
->state
== SSH_STATE_CLOSED
) {
2048 static void ssh_do_close(Ssh ssh
)
2051 struct ssh_channel
*c
;
2053 ssh
->state
= SSH_STATE_CLOSED
;
2059 * Now we must shut down any port and X forwardings going
2060 * through this connection.
2062 if (ssh
->channels
) {
2063 for (i
= 0; NULL
!= (c
= index234(ssh
->channels
, i
)); i
++) {
2066 x11_close(c
->u
.x11
.s
);
2069 pfd_close(c
->u
.pfd
.s
);
2072 del234(ssh
->channels
, c
);
2073 if (ssh
->version
== 2)
2074 bufchain_clear(&c
->v
.v2
.outbuffer
);
2080 static int ssh_closing(Plug plug
, const char *error_msg
, int error_code
,
2083 Ssh ssh
= (Ssh
) plug
;
2086 /* A socket error has occurred. */
2087 logevent(error_msg
);
2088 connection_fatal(ssh
->frontend
, "%s", error_msg
);
2090 /* Otherwise, the remote side closed the connection normally. */
2095 static int ssh_receive(Plug plug
, int urgent
, char *data
, int len
)
2097 Ssh ssh
= (Ssh
) plug
;
2098 ssh_gotdata(ssh
, (unsigned char *)data
, len
);
2099 if (ssh
->state
== SSH_STATE_CLOSED
) {
2106 static void ssh_sent(Plug plug
, int bufsize
)
2108 Ssh ssh
= (Ssh
) plug
;
2110 * If the send backlog on the SSH socket itself clears, we
2111 * should unthrottle the whole world if it was throttled.
2113 if (bufsize
< SSH_MAX_BACKLOG
)
2114 ssh_throttle_all(ssh
, 0, bufsize
);
2118 * Connect to specified host and port.
2119 * Returns an error message, or NULL on success.
2120 * Also places the canonical host name into `realhost'. It must be
2121 * freed by the caller.
2123 static const char *connect_to_host(Ssh ssh
, char *host
, int port
,
2124 char **realhost
, int nodelay
)
2126 static const struct plug_function_table fn_table
= {
2136 ssh
->savedhost
= snewn(1 + strlen(host
), char);
2137 if (!ssh
->savedhost
)
2138 fatalbox("Out of memory");
2139 strcpy(ssh
->savedhost
, host
);
2142 port
= 22; /* default ssh port */
2143 ssh
->savedport
= port
;
2148 logeventf(ssh
, "Looking up host \"%s\"", host
);
2149 addr
= name_lookup(host
, port
, realhost
, &ssh
->cfg
);
2150 if ((err
= sk_addr_error(addr
)) != NULL
)
2158 sk_getaddr(addr
, addrbuf
, 100);
2159 logeventf(ssh
, "Connecting to %s port %d", addrbuf
, port
);
2161 ssh
->fn
= &fn_table
;
2162 ssh
->s
= new_connection(addr
, *realhost
, port
,
2163 0, 1, nodelay
, (Plug
) ssh
, &ssh
->cfg
);
2164 if ((err
= sk_socket_error(ssh
->s
)) != NULL
) {
2173 * Throttle or unthrottle the SSH connection.
2175 static void ssh1_throttle(Ssh ssh
, int adjust
)
2177 int old_count
= ssh
->v1_throttle_count
;
2178 ssh
->v1_throttle_count
+= adjust
;
2179 assert(ssh
->v1_throttle_count
>= 0);
2180 if (ssh
->v1_throttle_count
&& !old_count
) {
2181 sk_set_frozen(ssh
->s
, 1);
2182 } else if (!ssh
->v1_throttle_count
&& old_count
) {
2183 sk_set_frozen(ssh
->s
, 0);
2188 * Throttle or unthrottle _all_ local data streams (for when sends
2189 * on the SSH connection itself back up).
2191 static void ssh_throttle_all(Ssh ssh
, int enable
, int bufsize
)
2194 struct ssh_channel
*c
;
2196 if (enable
== ssh
->throttled_all
)
2198 ssh
->throttled_all
= enable
;
2199 ssh
->overall_bufsize
= bufsize
;
2202 for (i
= 0; NULL
!= (c
= index234(ssh
->channels
, i
)); i
++) {
2204 case CHAN_MAINSESSION
:
2206 * This is treated separately, outside the switch.
2210 x11_override_throttle(c
->u
.x11
.s
, enable
);
2213 /* Agent channels require no buffer management. */
2216 pfd_override_throttle(c
->u
.pfd
.s
, enable
);
2223 * Username and password input, abstracted off into routines
2224 * reusable in several places - even between SSH1 and SSH2.
2227 /* Set up a username or password input loop on a given buffer. */
2228 static void setup_userpass_input(Ssh ssh
, char *buffer
, int buflen
, int echo
)
2230 ssh
->userpass_input_buffer
= buffer
;
2231 ssh
->userpass_input_buflen
= buflen
;
2232 ssh
->userpass_input_bufpos
= 0;
2233 ssh
->userpass_input_echo
= echo
;
2237 * Process some terminal data in the course of username/password
2238 * input. Returns >0 for success (line of input returned in
2239 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2240 * for inconclusive (keep waiting for more input please).
2242 static int process_userpass_input(Ssh ssh
, unsigned char *in
, int inlen
)
2247 switch (c
= *in
++) {
2250 ssh
->userpass_input_buffer
[ssh
->userpass_input_bufpos
] = 0;
2251 ssh
->userpass_input_buffer
[ssh
->userpass_input_buflen
-1] = 0;
2256 if (ssh
->userpass_input_bufpos
> 0) {
2257 if (ssh
->userpass_input_echo
)
2258 c_write_str(ssh
, "\b \b");
2259 ssh
->userpass_input_bufpos
--;
2264 while (ssh
->userpass_input_bufpos
> 0) {
2265 if (ssh
->userpass_input_echo
)
2266 c_write_str(ssh
, "\b \b");
2267 ssh
->userpass_input_bufpos
--;
2276 * This simplistic check for printability is disabled
2277 * when we're doing password input, because some people
2278 * have control characters in their passwords.o
2280 if ((!ssh
->userpass_input_echo
||
2281 (c
>= ' ' && c
<= '~') ||
2282 ((unsigned char) c
>= 160))
2283 && ssh
->userpass_input_bufpos
< ssh
->userpass_input_buflen
-1) {
2284 ssh
->userpass_input_buffer
[ssh
->userpass_input_bufpos
++] = c
;
2285 if (ssh
->userpass_input_echo
)
2286 c_write(ssh
, &c
, 1);
2294 void ssh_agent_callback(void *sshv
, void *reply
, int replylen
)
2296 Ssh ssh
= (Ssh
) sshv
;
2298 ssh
->agent_response
= reply
;
2299 ssh
->agent_response_len
= replylen
;
2301 if (ssh
->version
== 1)
2302 do_ssh1_login(ssh
, NULL
, -1, 0);
2304 do_ssh2_authconn(ssh
, NULL
, -1, 0);
2307 void ssh_agentf_callback(void *cv
, void *reply
, int replylen
)
2309 struct ssh_channel
*c
= (struct ssh_channel
*)cv
;
2311 void *sentreply
= reply
;
2314 /* Fake SSH_AGENT_FAILURE. */
2315 sentreply
= "\0\0\0\1\5";
2318 if (ssh
->version
== 2) {
2319 ssh2_add_channel_data(c
, sentreply
, replylen
);
2322 send_packet(ssh
, SSH1_MSG_CHANNEL_DATA
,
2323 PKT_INT
, c
->remoteid
,
2325 PKT_DATA
, sentreply
, replylen
,
2333 * Handle the key exchange and user authentication phases.
2335 static int do_ssh1_login(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
2338 unsigned char cookie
[8];
2339 struct RSAKey servkey
, hostkey
;
2340 struct MD5Context md5c
;
2341 struct do_ssh1_login_state
{
2343 unsigned char *rsabuf
, *keystr1
, *keystr2
;
2344 unsigned long supported_ciphers_mask
, supported_auths_mask
;
2345 int tried_publickey
, tried_agent
;
2346 int tis_auth_refused
, ccard_auth_refused
;
2347 unsigned char session_id
[16];
2350 void *publickey_blob
;
2351 int publickey_bloblen
;
2357 unsigned char request
[5], *response
, *p
;
2366 crState(do_ssh1_login_state
);
2368 crBegin(ssh
->do_ssh1_login_crstate
);
2373 if (ssh
->pktin
.type
!= SSH1_SMSG_PUBLIC_KEY
) {
2374 bombout(("Public key packet not received"));
2378 logevent("Received public keys");
2380 memcpy(cookie
, ssh
->pktin
.body
, 8);
2382 i
= makekey(ssh
->pktin
.body
+ 8, &servkey
, &s
->keystr1
, 0);
2383 j
= makekey(ssh
->pktin
.body
+ 8 + i
, &hostkey
, &s
->keystr2
, 0);
2386 * Log the host key fingerprint.
2390 logevent("Host key fingerprint is:");
2391 strcpy(logmsg
, " ");
2392 hostkey
.comment
= NULL
;
2393 rsa_fingerprint(logmsg
+ strlen(logmsg
),
2394 sizeof(logmsg
) - strlen(logmsg
), &hostkey
);
2398 ssh
->v1_remote_protoflags
= GET_32BIT(ssh
->pktin
.body
+ 8 + i
+ j
);
2399 s
->supported_ciphers_mask
= GET_32BIT(ssh
->pktin
.body
+ 12 + i
+ j
);
2400 s
->supported_auths_mask
= GET_32BIT(ssh
->pktin
.body
+ 16 + i
+ j
);
2402 ssh
->v1_local_protoflags
=
2403 ssh
->v1_remote_protoflags
& SSH1_PROTOFLAGS_SUPPORTED
;
2404 ssh
->v1_local_protoflags
|= SSH1_PROTOFLAG_SCREEN_NUMBER
;
2407 MD5Update(&md5c
, s
->keystr2
, hostkey
.bytes
);
2408 MD5Update(&md5c
, s
->keystr1
, servkey
.bytes
);
2409 MD5Update(&md5c
, ssh
->pktin
.body
, 8);
2410 MD5Final(s
->session_id
, &md5c
);
2412 for (i
= 0; i
< 32; i
++)
2413 ssh
->session_key
[i
] = random_byte();
2415 s
->len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
2417 s
->rsabuf
= snewn(s
->len
, unsigned char);
2419 fatalbox("Out of memory");
2422 * Verify the host key.
2426 * First format the key into a string.
2428 int len
= rsastr_len(&hostkey
);
2429 char fingerprint
[100];
2430 char *keystr
= snewn(len
, char);
2432 fatalbox("Out of memory");
2433 rsastr_fmt(keystr
, &hostkey
);
2434 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
2435 verify_ssh_host_key(ssh
->frontend
,
2436 ssh
->savedhost
, ssh
->savedport
, "rsa", keystr
,
2441 for (i
= 0; i
< 32; i
++) {
2442 s
->rsabuf
[i
] = ssh
->session_key
[i
];
2444 s
->rsabuf
[i
] ^= s
->session_id
[i
];
2447 if (hostkey
.bytes
> servkey
.bytes
) {
2448 rsaencrypt(s
->rsabuf
, 32, &servkey
);
2449 rsaencrypt(s
->rsabuf
, servkey
.bytes
, &hostkey
);
2451 rsaencrypt(s
->rsabuf
, 32, &hostkey
);
2452 rsaencrypt(s
->rsabuf
, hostkey
.bytes
, &servkey
);
2455 logevent("Encrypted session key");
2458 int cipher_chosen
= 0, warn
= 0;
2459 char *cipher_string
= NULL
;
2461 for (i
= 0; !cipher_chosen
&& i
< CIPHER_MAX
; i
++) {
2462 int next_cipher
= ssh
->cfg
.ssh_cipherlist
[i
];
2463 if (next_cipher
== CIPHER_WARN
) {
2464 /* If/when we choose a cipher, warn about it */
2466 } else if (next_cipher
== CIPHER_AES
) {
2467 /* XXX Probably don't need to mention this. */
2468 logevent("AES not supported in SSH1, skipping");
2470 switch (next_cipher
) {
2471 case CIPHER_3DES
: s
->cipher_type
= SSH_CIPHER_3DES
;
2472 cipher_string
= "3DES"; break;
2473 case CIPHER_BLOWFISH
: s
->cipher_type
= SSH_CIPHER_BLOWFISH
;
2474 cipher_string
= "Blowfish"; break;
2475 case CIPHER_DES
: s
->cipher_type
= SSH_CIPHER_DES
;
2476 cipher_string
= "single-DES"; break;
2478 if (s
->supported_ciphers_mask
& (1 << s
->cipher_type
))
2482 if (!cipher_chosen
) {
2483 if ((s
->supported_ciphers_mask
& (1 << SSH_CIPHER_3DES
)) == 0)
2484 bombout(("Server violates SSH 1 protocol by not "
2485 "supporting 3DES encryption"));
2487 /* shouldn't happen */
2488 bombout(("No supported ciphers found"));
2492 /* Warn about chosen cipher if necessary. */
2494 askcipher(ssh
->frontend
, cipher_string
, 0);
2497 switch (s
->cipher_type
) {
2498 case SSH_CIPHER_3DES
:
2499 logevent("Using 3DES encryption");
2501 case SSH_CIPHER_DES
:
2502 logevent("Using single-DES encryption");
2504 case SSH_CIPHER_BLOWFISH
:
2505 logevent("Using Blowfish encryption");
2509 send_packet(ssh
, SSH1_CMSG_SESSION_KEY
,
2510 PKT_CHAR
, s
->cipher_type
,
2511 PKT_DATA
, cookie
, 8,
2512 PKT_CHAR
, (s
->len
* 8) >> 8, PKT_CHAR
, (s
->len
* 8) & 0xFF,
2513 PKT_DATA
, s
->rsabuf
, s
->len
,
2514 PKT_INT
, ssh
->v1_local_protoflags
, PKT_END
);
2516 logevent("Trying to enable encryption...");
2520 ssh
->cipher
= (s
->cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
2521 s
->cipher_type
== SSH_CIPHER_DES ?
&ssh_des
:
2523 ssh
->v1_cipher_ctx
= ssh
->cipher
->make_context();
2524 ssh
->cipher
->sesskey(ssh
->v1_cipher_ctx
, ssh
->session_key
);
2525 logeventf(ssh
, "Initialised %s encryption", ssh
->cipher
->text_name
);
2527 ssh
->crcda_ctx
= crcda_make_context();
2528 logevent("Installing CRC compensation attack detector");
2532 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2533 bombout(("Encryption not successfully enabled"));
2537 logevent("Successfully started encryption");
2541 if ((flags
& FLAG_INTERACTIVE
) && !*ssh
->cfg
.username
) {
2542 if (ssh_get_line
&& !ssh_getline_pw_only
) {
2543 if (!ssh_get_line("login as: ",
2544 s
->username
, sizeof(s
->username
), FALSE
)) {
2546 * get_line failed to get a username.
2549 logevent("No username provided. Abandoning session.");
2550 ssh_closing((Plug
)ssh
, NULL
, 0, 0);
2554 int ret
; /* need not be kept over crReturn */
2555 c_write_str(ssh
, "login as: ");
2558 setup_userpass_input(ssh
, s
->username
, sizeof(s
->username
), 1);
2560 crWaitUntil(!ispkt
);
2561 ret
= process_userpass_input(ssh
, in
, inlen
);
2565 c_write_str(ssh
, "\r\n");
2568 strncpy(s
->username
, ssh
->cfg
.username
, sizeof(s
->username
));
2569 s
->username
[sizeof(s
->username
)-1] = '\0';
2572 send_packet(ssh
, SSH1_CMSG_USER
, PKT_STR
, s
->username
, PKT_END
);
2574 char userlog
[22 + sizeof(s
->username
)];
2575 sprintf(userlog
, "Sent username \"%s\"", s
->username
);
2577 if (flags
& FLAG_INTERACTIVE
&&
2578 (!((flags
& FLAG_STDERR
) && (flags
& FLAG_VERBOSE
)))) {
2579 strcat(userlog
, "\r\n");
2580 c_write_str(ssh
, userlog
);
2587 if ((ssh
->remote_bugs
& BUG_CHOKES_ON_RSA
)) {
2588 /* We must not attempt PK auth. Pretend we've already tried it. */
2589 s
->tried_publickey
= s
->tried_agent
= 1;
2591 s
->tried_publickey
= s
->tried_agent
= 0;
2593 s
->tis_auth_refused
= s
->ccard_auth_refused
= 0;
2594 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
2595 if (!filename_is_null(ssh
->cfg
.keyfile
)) {
2596 if (!rsakey_pubblob(&ssh
->cfg
.keyfile
,
2597 &s
->publickey_blob
, &s
->publickey_bloblen
))
2598 s
->publickey_blob
= NULL
;
2600 s
->publickey_blob
= NULL
;
2602 while (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2603 s
->pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
2605 if (agent_exists() && !s
->tried_agent
) {
2607 * Attempt RSA authentication using Pageant.
2613 logevent("Pageant is running. Requesting keys.");
2615 /* Request the keys held by the agent. */
2616 PUT_32BIT(s
->request
, 1);
2617 s
->request
[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES
;
2618 if (!agent_query(s
->request
, 5, &r
, &s
->responselen
,
2619 ssh_agent_callback
, ssh
)) {
2623 bombout(("Unexpected data from server while waiting"
2624 " for agent response"));
2627 } while (ispkt
|| inlen
> 0);
2628 r
= ssh
->agent_response
;
2629 s
->responselen
= ssh
->agent_response_len
;
2631 s
->response
= (unsigned char *) r
;
2632 if (s
->response
&& s
->responselen
>= 5 &&
2633 s
->response
[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER
) {
2634 s
->p
= s
->response
+ 5;
2635 s
->nkeys
= GET_32BIT(s
->p
);
2639 sprintf(buf
, "Pageant has %d SSH1 keys", s
->nkeys
);
2642 for (s
->keyi
= 0; s
->keyi
< s
->nkeys
; s
->keyi
++) {
2645 sprintf(buf
, "Trying Pageant key #%d", s
->keyi
);
2648 if (s
->publickey_blob
&&
2649 !memcmp(s
->p
, s
->publickey_blob
,
2650 s
->publickey_bloblen
)) {
2651 logevent("This key matches configured key file");
2652 s
->tried_publickey
= 1;
2655 s
->p
+= ssh1_read_bignum(s
->p
, &s
->key
.exponent
);
2656 s
->p
+= ssh1_read_bignum(s
->p
, &s
->key
.modulus
);
2657 s
->commentlen
= GET_32BIT(s
->p
);
2659 s
->commentp
= (char *)s
->p
;
2660 s
->p
+= s
->commentlen
;
2661 send_packet(ssh
, SSH1_CMSG_AUTH_RSA
,
2662 PKT_BIGNUM
, s
->key
.modulus
, PKT_END
);
2664 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2665 logevent("Key refused");
2668 logevent("Received RSA challenge");
2669 ssh1_read_bignum(ssh
->pktin
.body
, &s
->challenge
);
2671 char *agentreq
, *q
, *ret
;
2674 len
= 1 + 4; /* message type, bit count */
2675 len
+= ssh1_bignum_length(s
->key
.exponent
);
2676 len
+= ssh1_bignum_length(s
->key
.modulus
);
2677 len
+= ssh1_bignum_length(s
->challenge
);
2678 len
+= 16; /* session id */
2679 len
+= 4; /* response format */
2680 agentreq
= snewn(4 + len
, char);
2681 PUT_32BIT(agentreq
, len
);
2683 *q
++ = SSH1_AGENTC_RSA_CHALLENGE
;
2684 PUT_32BIT(q
, bignum_bitcount(s
->key
.modulus
));
2686 q
+= ssh1_write_bignum(q
, s
->key
.exponent
);
2687 q
+= ssh1_write_bignum(q
, s
->key
.modulus
);
2688 q
+= ssh1_write_bignum(q
, s
->challenge
);
2689 memcpy(q
, s
->session_id
, 16);
2691 PUT_32BIT(q
, 1); /* response format */
2692 if (!agent_query(agentreq
, len
+ 4, &vret
, &retlen
,
2693 ssh_agent_callback
, ssh
)) {
2698 bombout(("Unexpected data from server"
2699 " while waiting for agent"
2703 } while (ispkt
|| inlen
> 0);
2704 vret
= ssh
->agent_response
;
2705 retlen
= ssh
->agent_response_len
;
2710 if (ret
[4] == SSH1_AGENT_RSA_RESPONSE
) {
2711 logevent("Sending Pageant's response");
2712 send_packet(ssh
, SSH1_CMSG_AUTH_RSA_RESPONSE
,
2713 PKT_DATA
, ret
+ 5, 16,
2717 if (ssh
->pktin
.type
== SSH1_SMSG_SUCCESS
) {
2719 ("Pageant's response accepted");
2720 if (flags
& FLAG_VERBOSE
) {
2721 c_write_str(ssh
, "Authenticated using"
2723 c_write(ssh
, s
->commentp
,
2725 c_write_str(ssh
, "\" from agent\r\n");
2730 ("Pageant's response not accepted");
2733 ("Pageant failed to answer challenge");
2737 logevent("No reply received from Pageant");
2740 freebn(s
->key
.exponent
);
2741 freebn(s
->key
.modulus
);
2742 freebn(s
->challenge
);
2750 if (!filename_is_null(ssh
->cfg
.keyfile
) && !s
->tried_publickey
)
2751 s
->pwpkt_type
= SSH1_CMSG_AUTH_RSA
;
2753 if (ssh
->cfg
.try_tis_auth
&&
2754 (s
->supported_auths_mask
& (1 << SSH1_AUTH_TIS
)) &&
2755 !s
->tis_auth_refused
) {
2756 s
->pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
2757 logevent("Requested TIS authentication");
2758 send_packet(ssh
, SSH1_CMSG_AUTH_TIS
, PKT_END
);
2760 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
2761 logevent("TIS authentication declined");
2762 if (flags
& FLAG_INTERACTIVE
)
2763 c_write_str(ssh
, "TIS authentication refused.\r\n");
2764 s
->tis_auth_refused
= 1;
2767 int challengelen
= GET_32BIT(ssh
->pktin
.body
);
2768 logevent("Received TIS challenge");
2769 if (challengelen
> sizeof(s
->prompt
) - 1)
2770 challengelen
= sizeof(s
->prompt
) - 1;/* prevent overrun */
2771 memcpy(s
->prompt
, ssh
->pktin
.body
+ 4, challengelen
);
2772 /* Prompt heuristic comes from OpenSSH */
2773 strncpy(s
->prompt
+ challengelen
,
2774 memchr(s
->prompt
, '\n', challengelen
) ?
2775 "": "\r\nResponse: ",
2776 (sizeof s
->prompt
) - challengelen
);
2777 s
->prompt
[(sizeof s
->prompt
) - 1] = '\0';
2780 if (ssh
->cfg
.try_tis_auth
&&
2781 (s
->supported_auths_mask
& (1 << SSH1_AUTH_CCARD
)) &&
2782 !s
->ccard_auth_refused
) {
2783 s
->pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
2784 logevent("Requested CryptoCard authentication");
2785 send_packet(ssh
, SSH1_CMSG_AUTH_CCARD
, PKT_END
);
2787 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
2788 logevent("CryptoCard authentication declined");
2789 c_write_str(ssh
, "CryptoCard authentication refused.\r\n");
2790 s
->ccard_auth_refused
= 1;
2793 int challengelen
= GET_32BIT(ssh
->pktin
.body
);
2794 logevent("Received CryptoCard challenge");
2795 if (challengelen
> sizeof(s
->prompt
) - 1)
2796 challengelen
= sizeof(s
->prompt
) - 1;/* prevent overrun */
2797 memcpy(s
->prompt
, ssh
->pktin
.body
+ 4, challengelen
);
2798 strncpy(s
->prompt
+ challengelen
,
2799 memchr(s
->prompt
, '\n', challengelen
) ?
2800 "" : "\r\nResponse: ",
2801 sizeof(s
->prompt
) - challengelen
);
2802 s
->prompt
[sizeof(s
->prompt
) - 1] = '\0';
2805 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2806 sprintf(s
->prompt
, "%.90s@%.90s's password: ",
2807 s
->username
, ssh
->savedhost
);
2809 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2810 char *comment
= NULL
;
2813 if (flags
& FLAG_VERBOSE
)
2814 c_write_str(ssh
, "Trying public key authentication.\r\n");
2815 logeventf(ssh
, "Trying public key \"%s\"",
2816 filename_to_str(&ssh
->cfg
.keyfile
));
2817 type
= key_type(&ssh
->cfg
.keyfile
);
2818 if (type
!= SSH_KEYTYPE_SSH1
) {
2819 sprintf(msgbuf
, "Key is of wrong type (%s)",
2820 key_type_to_str(type
));
2822 c_write_str(ssh
, msgbuf
);
2823 c_write_str(ssh
, "\r\n");
2824 s
->tried_publickey
= 1;
2827 if (!rsakey_encrypted(&ssh
->cfg
.keyfile
, &comment
)) {
2828 if (flags
& FLAG_VERBOSE
)
2829 c_write_str(ssh
, "No passphrase required.\r\n");
2832 sprintf(s
->prompt
, "Passphrase for key \"%.100s\": ", comment
);
2837 * Show password prompt, having first obtained it via a TIS
2838 * or CryptoCard exchange if we're doing TIS or CryptoCard
2842 if (!ssh_get_line(s
->prompt
, s
->password
,
2843 sizeof(s
->password
), TRUE
)) {
2845 * get_line failed to get a password (for example
2846 * because one was supplied on the command line
2847 * which has already failed to work). Terminate.
2849 send_packet(ssh
, SSH1_MSG_DISCONNECT
,
2850 PKT_STR
, "No more passwords available to try",
2852 logevent("Unable to authenticate");
2853 connection_fatal(ssh
->frontend
, "Unable to authenticate");
2854 ssh_closing((Plug
)ssh
, NULL
, 0, 0);
2858 /* Prompt may have come from server. We've munged it a bit, so
2859 * we know it to be zero-terminated at least once. */
2860 int ret
; /* need not be saved over crReturn */
2861 c_write_untrusted(ssh
, s
->prompt
, strlen(s
->prompt
));
2864 setup_userpass_input(ssh
, s
->password
, sizeof(s
->password
), 0);
2866 crWaitUntil(!ispkt
);
2867 ret
= process_userpass_input(ssh
, in
, inlen
);
2871 c_write_str(ssh
, "\r\n");
2875 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2877 * Try public key authentication with the specified
2880 s
->tried_publickey
= 1;
2883 int ret
= loadrsakey(&ssh
->cfg
.keyfile
, &s
->key
, s
->password
);
2885 c_write_str(ssh
, "Couldn't load private key from ");
2886 c_write_str(ssh
, filename_to_str(&ssh
->cfg
.keyfile
));
2887 c_write_str(ssh
, ".\r\n");
2888 continue; /* go and try password */
2891 c_write_str(ssh
, "Wrong passphrase.\r\n");
2892 s
->tried_publickey
= 0;
2893 continue; /* try again */
2898 * Send a public key attempt.
2900 send_packet(ssh
, SSH1_CMSG_AUTH_RSA
,
2901 PKT_BIGNUM
, s
->key
.modulus
, PKT_END
);
2904 if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2905 c_write_str(ssh
, "Server refused our public key.\r\n");
2906 continue; /* go and try password */
2908 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2909 bombout(("Bizarre response to offer of public key"));
2915 unsigned char buffer
[32];
2916 Bignum challenge
, response
;
2918 ssh1_read_bignum(ssh
->pktin
.body
, &challenge
);
2919 response
= rsadecrypt(challenge
, &s
->key
);
2920 freebn(s
->key
.private_exponent
);/* burn the evidence */
2922 for (i
= 0; i
< 32; i
++) {
2923 buffer
[i
] = bignum_byte(response
, 31 - i
);
2927 MD5Update(&md5c
, buffer
, 32);
2928 MD5Update(&md5c
, s
->session_id
, 16);
2929 MD5Final(buffer
, &md5c
);
2931 send_packet(ssh
, SSH1_CMSG_AUTH_RSA_RESPONSE
,
2932 PKT_DATA
, buffer
, 16, PKT_END
);
2939 if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2940 if (flags
& FLAG_VERBOSE
)
2941 c_write_str(ssh
, "Failed to authenticate with"
2942 " our public key.\r\n");
2943 continue; /* go and try password */
2944 } else if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2945 bombout(("Bizarre response to RSA authentication response"));
2949 break; /* we're through! */
2951 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2953 * Defence against traffic analysis: we send a
2954 * whole bunch of packets containing strings of
2955 * different lengths. One of these strings is the
2956 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2957 * The others are all random data in
2958 * SSH1_MSG_IGNORE packets. This way a passive
2959 * listener can't tell which is the password, and
2960 * hence can't deduce the password length.
2962 * Anybody with a password length greater than 16
2963 * bytes is going to have enough entropy in their
2964 * password that a listener won't find it _that_
2965 * much help to know how long it is. So what we'll
2968 * - if password length < 16, we send 15 packets
2969 * containing string lengths 1 through 15
2971 * - otherwise, we let N be the nearest multiple
2972 * of 8 below the password length, and send 8
2973 * packets containing string lengths N through
2974 * N+7. This won't obscure the order of
2975 * magnitude of the password length, but it will
2976 * introduce a bit of extra uncertainty.
2978 * A few servers (the old 1.2.18 through 1.2.22)
2979 * can't deal with SSH1_MSG_IGNORE. For these
2980 * servers, we need an alternative defence. We make
2981 * use of the fact that the password is interpreted
2982 * as a C string: so we can append a NUL, then some
2985 * One server (a Cisco one) can deal with neither
2986 * SSH1_MSG_IGNORE _nor_ a padded password string.
2987 * For this server we are left with no defences
2988 * against password length sniffing.
2990 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
)) {
2992 * The server can deal with SSH1_MSG_IGNORE, so
2993 * we can use the primary defence.
2995 int bottom
, top
, pwlen
, i
;
2998 pwlen
= strlen(s
->password
);
3000 bottom
= 0; /* zero length passwords are OK! :-) */
3003 bottom
= pwlen
& ~7;
3007 assert(pwlen
>= bottom
&& pwlen
<= top
);
3009 randomstr
= snewn(top
+ 1, char);
3011 for (i
= bottom
; i
<= top
; i
++) {
3013 defer_packet(ssh
, s
->pwpkt_type
,
3014 PKT_STR
, s
->password
, PKT_END
);
3016 for (j
= 0; j
< i
; j
++) {
3018 randomstr
[j
] = random_byte();
3019 } while (randomstr
[j
] == '\0');
3021 randomstr
[i
] = '\0';
3022 defer_packet(ssh
, SSH1_MSG_IGNORE
,
3023 PKT_STR
, randomstr
, PKT_END
);
3026 logevent("Sending password with camouflage packets");
3027 ssh_pkt_defersend(ssh
);
3029 else if (!(ssh
->remote_bugs
& BUG_NEEDS_SSH1_PLAIN_PASSWORD
)) {
3031 * The server can't deal with SSH1_MSG_IGNORE
3032 * but can deal with padded passwords, so we
3033 * can use the secondary defence.
3039 len
= strlen(s
->password
);
3040 if (len
< sizeof(string
)) {
3042 strcpy(string
, s
->password
);
3043 len
++; /* cover the zero byte */
3044 while (len
< sizeof(string
)) {
3045 string
[len
++] = (char) random_byte();
3050 logevent("Sending length-padded password");
3051 send_packet(ssh
, s
->pwpkt_type
, PKT_INT
, len
,
3052 PKT_DATA
, ss
, len
, PKT_END
);
3055 * The server has _both_
3056 * BUG_CHOKES_ON_SSH1_IGNORE and
3057 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3058 * therefore nothing we can do.
3061 len
= strlen(s
->password
);
3062 logevent("Sending unpadded password");
3063 send_packet(ssh
, s
->pwpkt_type
, PKT_INT
, len
,
3064 PKT_DATA
, s
->password
, len
, PKT_END
);
3067 send_packet(ssh
, s
->pwpkt_type
, PKT_STR
, s
->password
, PKT_END
);
3070 logevent("Sent password");
3071 memset(s
->password
, 0, strlen(s
->password
));
3073 if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3074 if (flags
& FLAG_VERBOSE
)
3075 c_write_str(ssh
, "Access denied\r\n");
3076 logevent("Authentication refused");
3077 } else if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
) {
3078 bombout(("Strange packet received, type %d", ssh
->pktin
.type
));
3083 logevent("Authentication successful");
3088 void sshfwd_close(struct ssh_channel
*c
)
3092 if (ssh
->state
!= SSH_STATE_SESSION
) {
3093 assert(ssh
->state
== SSH_STATE_CLOSED
);
3097 if (c
&& !c
->closes
) {
3099 * If the channel's remoteid is -1, we have sent
3100 * CHANNEL_OPEN for this channel, but it hasn't even been
3101 * acknowledged by the server. So we must set a close flag
3102 * on it now, and then when the server acks the channel
3103 * open, we can close it then.
3105 if (((int)c
->remoteid
) != -1) {
3106 if (ssh
->version
== 1) {
3107 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
3110 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_CLOSE
);
3111 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
3115 c
->closes
= 1; /* sent MSG_CLOSE */
3116 if (c
->type
== CHAN_X11
) {
3118 logevent("Forwarded X11 connection terminated");
3119 } else if (c
->type
== CHAN_SOCKDATA
||
3120 c
->type
== CHAN_SOCKDATA_DORMANT
) {
3122 logevent("Forwarded port closed");
3127 int sshfwd_write(struct ssh_channel
*c
, char *buf
, int len
)
3131 if (ssh
->state
!= SSH_STATE_SESSION
) {
3132 assert(ssh
->state
== SSH_STATE_CLOSED
);
3136 if (ssh
->version
== 1) {
3137 send_packet(ssh
, SSH1_MSG_CHANNEL_DATA
,
3138 PKT_INT
, c
->remoteid
,
3139 PKT_INT
, len
, PKT_DATA
, buf
, len
, PKT_END
);
3141 * In SSH1 we can return 0 here - implying that forwarded
3142 * connections are never individually throttled - because
3143 * the only circumstance that can cause throttling will be
3144 * the whole SSH connection backing up, in which case
3145 * _everything_ will be throttled as a whole.
3149 ssh2_add_channel_data(c
, buf
, len
);
3150 return ssh2_try_send(c
);
3154 void sshfwd_unthrottle(struct ssh_channel
*c
, int bufsize
)
3158 if (ssh
->state
!= SSH_STATE_SESSION
) {
3159 assert(ssh
->state
== SSH_STATE_CLOSED
);
3163 if (ssh
->version
== 1) {
3164 if (c
->v
.v1
.throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
3165 c
->v
.v1
.throttling
= 0;
3166 ssh1_throttle(ssh
, -1);
3169 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
3173 static void ssh1_protocol(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
3175 crBegin(ssh
->ssh1_protocol_crstate
);
3179 while (!do_ssh1_login(ssh
, in
, inlen
, ispkt
)) {
3182 if (ssh
->state
== SSH_STATE_CLOSED
)
3185 if (ssh
->cfg
.agentfwd
&& agent_exists()) {
3186 logevent("Requesting agent forwarding");
3187 send_packet(ssh
, SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
3191 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3192 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3193 bombout(("Protocol confusion"));
3195 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3196 logevent("Agent forwarding refused");
3198 logevent("Agent forwarding enabled");
3199 ssh
->agentfwd_enabled
= TRUE
;
3203 if (ssh
->cfg
.x11_forward
) {
3204 char proto
[20], data
[64];
3205 logevent("Requesting X11 forwarding");
3206 ssh
->x11auth
= x11_invent_auth(proto
, sizeof(proto
),
3207 data
, sizeof(data
), ssh
->cfg
.x11_auth
);
3208 x11_get_real_auth(ssh
->x11auth
, ssh
->cfg
.x11_display
);
3209 if (ssh
->v1_local_protoflags
& SSH1_PROTOFLAG_SCREEN_NUMBER
) {
3210 send_packet(ssh
, SSH1_CMSG_X11_REQUEST_FORWARDING
,
3211 PKT_STR
, proto
, PKT_STR
, data
,
3212 PKT_INT
, x11_get_screen_number(ssh
->cfg
.x11_display
),
3215 send_packet(ssh
, SSH1_CMSG_X11_REQUEST_FORWARDING
,
3216 PKT_STR
, proto
, PKT_STR
, data
, PKT_END
);
3221 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3222 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3223 bombout(("Protocol confusion"));
3225 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3226 logevent("X11 forwarding refused");
3228 logevent("X11 forwarding enabled");
3229 ssh
->X11_fwd_enabled
= TRUE
;
3236 int sport
,dport
,sserv
,dserv
;
3237 char sports
[256], dports
[256], saddr
[256], host
[256];
3239 ssh
->rportfwds
= newtree234(ssh_rportcmp_ssh1
);
3240 /* Add port forwardings. */
3241 ssh
->portfwd_strptr
= ssh
->cfg
.portfwd
;
3242 while (*ssh
->portfwd_strptr
) {
3243 type
= *ssh
->portfwd_strptr
++;
3246 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= '\t') {
3247 if (*ssh
->portfwd_strptr
== ':') {
3249 * We've seen a colon in the middle of the
3250 * source port number. This means that
3251 * everything we've seen until now is the
3252 * source _address_, so we'll move it into
3253 * saddr and start sports from the beginning
3256 ssh
->portfwd_strptr
++;
3258 strcpy(saddr
, sports
);
3261 if (n
< 255) sports
[n
++] = *ssh
->portfwd_strptr
++;
3265 if (*ssh
->portfwd_strptr
== '\t')
3266 ssh
->portfwd_strptr
++;
3268 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= ':') {
3269 if (n
< 255) host
[n
++] = *ssh
->portfwd_strptr
++;
3272 if (*ssh
->portfwd_strptr
== ':')
3273 ssh
->portfwd_strptr
++;
3275 while (*ssh
->portfwd_strptr
) {
3276 if (n
< 255) dports
[n
++] = *ssh
->portfwd_strptr
++;
3279 ssh
->portfwd_strptr
++;
3280 dport
= atoi(dports
);
3284 dport
= net_service_lookup(dports
);
3286 logeventf(ssh
, "Service lookup failed for"
3287 " destination port \"%s\"", dports
);
3291 while (*ssh
->portfwd_strptr
) ssh
->portfwd_strptr
++;
3294 sport
= atoi(sports
);
3298 sport
= net_service_lookup(sports
);
3300 logeventf(ssh
, "Service lookup failed for source"
3301 " port \"%s\"", sports
);
3304 if (sport
&& dport
) {
3306 pfd_addforward(host
, dport
, *saddr ? saddr
: NULL
,
3307 sport
, ssh
, &ssh
->cfg
);
3308 logeventf(ssh
, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3309 " forwarding to %s:%.*s%.*s%d%.*s",
3310 (int)(*saddr?
strlen(saddr
):0), *saddr?saddr
:NULL
,
3311 (int)(*saddr?
1:0), ":",
3312 (int)(sserv ?
strlen(sports
) : 0), sports
,
3313 sserv
, "(", sport
, sserv
, ")",
3315 (int)(dserv ?
strlen(dports
) : 0), dports
,
3316 dserv
, "(", dport
, dserv
, ")");
3317 } else if (type
== 'D') {
3318 pfd_addforward(NULL
, -1, *saddr ? saddr
: NULL
,
3319 sport
, ssh
, &ssh
->cfg
);
3320 logeventf(ssh
, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3321 " doing SOCKS dynamic forwarding",
3322 (int)(*saddr?
strlen(saddr
):0), *saddr?saddr
:NULL
,
3323 (int)(*saddr?
1:0), ":",
3324 (int)(sserv ?
strlen(sports
) : 0), sports
,
3325 sserv
, "(", sport
, sserv
, ")");
3327 struct ssh_rportfwd
*pf
;
3328 pf
= snew(struct ssh_rportfwd
);
3329 strcpy(pf
->dhost
, host
);
3333 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
3336 if (add234(ssh
->rportfwds
, pf
) != pf
) {
3338 "Duplicate remote port forwarding to %s:%d",
3342 logeventf(ssh
, "Requesting remote port %.*s%.*s%d%.*s"
3343 " forward to %s:%.*s%.*s%d%.*s",
3344 (int)(sserv ?
strlen(sports
) : 0), sports
,
3345 sserv
, "(", sport
, sserv
, ")",
3347 (int)(dserv ?
strlen(dports
) : 0), dports
,
3348 dserv
, "(", dport
, dserv
, ")");
3349 send_packet(ssh
, SSH1_CMSG_PORT_FORWARD_REQUEST
,
3357 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3358 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3359 bombout(("Protocol confusion"));
3361 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3362 c_write_str(ssh
, "Server refused port"
3365 logevent("Remote port forwarding enabled");
3372 if (!ssh
->cfg
.nopty
) {
3373 send_packet(ssh
, SSH1_CMSG_REQUEST_PTY
,
3374 PKT_STR
, ssh
->cfg
.termtype
,
3375 PKT_INT
, ssh
->term_height
,
3376 PKT_INT
, ssh
->term_width
,
3377 PKT_INT
, 0, PKT_INT
, 0, PKT_CHAR
, 0, PKT_END
);
3378 ssh
->state
= SSH_STATE_INTERMED
;
3382 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3383 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3384 bombout(("Protocol confusion"));
3386 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3387 c_write_str(ssh
, "Server refused to allocate pty\r\n");
3388 ssh
->editing
= ssh
->echoing
= 1;
3390 logevent("Allocated pty");
3392 ssh
->editing
= ssh
->echoing
= 1;
3395 if (ssh
->cfg
.compression
) {
3396 send_packet(ssh
, SSH1_CMSG_REQUEST_COMPRESSION
, PKT_INT
, 6, PKT_END
);
3400 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3401 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3402 bombout(("Protocol confusion"));
3404 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3405 c_write_str(ssh
, "Server refused to compress\r\n");
3407 logevent("Started compression");
3408 ssh
->v1_compressing
= TRUE
;
3409 ssh
->cs_comp_ctx
= zlib_compress_init();
3410 logevent("Initialised zlib (RFC1950) compression");
3411 ssh
->sc_comp_ctx
= zlib_decompress_init();
3412 logevent("Initialised zlib (RFC1950) decompression");
3416 * Start the shell or command.
3418 * Special case: if the first-choice command is an SSH2
3419 * subsystem (hence not usable here) and the second choice
3420 * exists, we fall straight back to that.
3423 char *cmd
= ssh
->cfg
.remote_cmd_ptr
;
3425 if (ssh
->cfg
.ssh_subsys
&& ssh
->cfg
.remote_cmd_ptr2
) {
3426 cmd
= ssh
->cfg
.remote_cmd_ptr2
;
3427 ssh
->fallback_cmd
= TRUE
;
3430 send_packet(ssh
, SSH1_CMSG_EXEC_CMD
, PKT_STR
, cmd
, PKT_END
);
3432 send_packet(ssh
, SSH1_CMSG_EXEC_SHELL
, PKT_END
);
3433 logevent("Started session");
3436 ssh
->state
= SSH_STATE_SESSION
;
3437 if (ssh
->size_needed
)
3438 ssh_size(ssh
, ssh
->term_width
, ssh
->term_height
);
3439 if (ssh
->eof_needed
)
3440 ssh_special(ssh
, TS_EOF
);
3443 ldisc_send(ssh
->ldisc
, NULL
, 0, 0);/* cause ldisc to notice changes */
3445 ssh
->channels
= newtree234(ssh_channelcmp
);
3449 if (ssh
->pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
3450 ssh
->pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
3451 long len
= GET_32BIT(ssh
->pktin
.body
);
3453 from_backend(ssh
->frontend
,
3454 ssh
->pktin
.type
== SSH1_SMSG_STDERR_DATA
,
3455 (char *)(ssh
->pktin
.body
) + 4, len
);
3456 if (!ssh
->v1_stdout_throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
3457 ssh
->v1_stdout_throttling
= 1;
3458 ssh1_throttle(ssh
, +1);
3460 } else if (ssh
->pktin
.type
== SSH1_MSG_DISCONNECT
) {
3461 ssh_closing((Plug
)ssh
, NULL
, 0, 0);
3462 logevent("Received disconnect request");
3464 } else if (ssh
->pktin
.type
== SSH1_SMSG_X11_OPEN
) {
3465 /* Remote side is trying to open a channel to talk to our
3466 * X-Server. Give them back a local channel number. */
3467 struct ssh_channel
*c
;
3469 logevent("Received X11 connect request");
3470 /* Refuse if X11 forwarding is disabled. */
3471 if (!ssh
->X11_fwd_enabled
) {
3472 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3473 PKT_INT
, GET_32BIT(ssh
->pktin
.body
), PKT_END
);
3474 logevent("Rejected X11 connect request");
3476 c
= snew(struct ssh_channel
);
3479 if (x11_init(&c
->u
.x11
.s
, ssh
->cfg
.x11_display
, c
,
3480 ssh
->x11auth
, NULL
, -1, &ssh
->cfg
) != NULL
) {
3481 logevent("opening X11 forward connection failed");
3483 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3484 PKT_INT
, GET_32BIT(ssh
->pktin
.body
),
3488 ("opening X11 forward connection succeeded");
3489 c
->remoteid
= GET_32BIT(ssh
->pktin
.body
);
3490 c
->localid
= alloc_channel_id(ssh
);
3492 c
->v
.v1
.throttling
= 0;
3493 c
->type
= CHAN_X11
; /* identify channel type */
3494 add234(ssh
->channels
, c
);
3495 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3496 PKT_INT
, c
->remoteid
, PKT_INT
,
3497 c
->localid
, PKT_END
);
3498 logevent("Opened X11 forward channel");
3501 } else if (ssh
->pktin
.type
== SSH1_SMSG_AGENT_OPEN
) {
3502 /* Remote side is trying to open a channel to talk to our
3503 * agent. Give them back a local channel number. */
3504 struct ssh_channel
*c
;
3506 /* Refuse if agent forwarding is disabled. */
3507 if (!ssh
->agentfwd_enabled
) {
3508 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3509 PKT_INT
, GET_32BIT(ssh
->pktin
.body
), PKT_END
);
3511 c
= snew(struct ssh_channel
);
3513 c
->remoteid
= GET_32BIT(ssh
->pktin
.body
);
3514 c
->localid
= alloc_channel_id(ssh
);
3516 c
->v
.v1
.throttling
= 0;
3517 c
->type
= CHAN_AGENT
; /* identify channel type */
3518 c
->u
.a
.lensofar
= 0;
3519 add234(ssh
->channels
, c
);
3520 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3521 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
3524 } else if (ssh
->pktin
.type
== SSH1_MSG_PORT_OPEN
) {
3525 /* Remote side is trying to open a channel to talk to a
3526 * forwarded port. Give them back a local channel number. */
3527 struct ssh_channel
*c
;
3528 struct ssh_rportfwd pf
;
3530 char host
[256], buf
[1024];
3533 c
= snew(struct ssh_channel
);
3536 hostsize
= GET_32BIT(ssh
->pktin
.body
+4);
3537 for (h
= host
, p
= (char *)(ssh
->pktin
.body
+8);
3538 hostsize
!= 0; hostsize
--) {
3539 if (h
+1 < host
+sizeof(host
))
3544 port
= GET_32BIT(p
);
3546 strcpy(pf
.dhost
, host
);
3549 if (find234(ssh
->rportfwds
, &pf
, NULL
) == NULL
) {
3550 sprintf(buf
, "Rejected remote port open request for %s:%d",
3553 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3554 PKT_INT
, GET_32BIT(ssh
->pktin
.body
), PKT_END
);
3556 sprintf(buf
, "Received remote port open request for %s:%d",
3559 e
= pfd_newconnect(&c
->u
.pfd
.s
, host
, port
, c
, &ssh
->cfg
);
3562 sprintf(buf
, "Port open failed: %s", e
);
3565 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3566 PKT_INT
, GET_32BIT(ssh
->pktin
.body
),
3569 c
->remoteid
= GET_32BIT(ssh
->pktin
.body
);
3570 c
->localid
= alloc_channel_id(ssh
);
3572 c
->v
.v1
.throttling
= 0;
3573 c
->type
= CHAN_SOCKDATA
; /* identify channel type */
3574 add234(ssh
->channels
, c
);
3575 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3576 PKT_INT
, c
->remoteid
, PKT_INT
,
3577 c
->localid
, PKT_END
);
3578 logevent("Forwarded port opened successfully");
3582 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
) {
3583 unsigned int remoteid
= GET_32BIT(ssh
->pktin
.body
);
3584 unsigned int localid
= GET_32BIT(ssh
->pktin
.body
+4);
3585 struct ssh_channel
*c
;
3587 c
= find234(ssh
->channels
, &remoteid
, ssh_channelfind
);
3588 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
3589 c
->remoteid
= localid
;
3590 c
->type
= CHAN_SOCKDATA
;
3591 c
->v
.v1
.throttling
= 0;
3592 pfd_confirm(c
->u
.pfd
.s
);
3595 if (c
&& c
->closes
) {
3597 * We have a pending close on this channel,
3598 * which we decided on before the server acked
3599 * the channel open. So now we know the
3600 * remoteid, we can close it again.
3602 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE
,
3603 PKT_INT
, c
->remoteid
, PKT_END
);
3606 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_OPEN_FAILURE
) {
3607 unsigned int remoteid
= GET_32BIT(ssh
->pktin
.body
);
3608 struct ssh_channel
*c
;
3610 c
= find234(ssh
->channels
, &remoteid
, ssh_channelfind
);
3611 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
3612 logevent("Forwarded connection refused by server");
3613 pfd_close(c
->u
.pfd
.s
);
3614 del234(ssh
->channels
, c
);
3618 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE
||
3619 ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
) {
3620 /* Remote side closes a channel. */
3621 unsigned i
= GET_32BIT(ssh
->pktin
.body
);
3622 struct ssh_channel
*c
;
3623 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
3624 if (c
&& ((int)c
->remoteid
) != -1) {
3627 (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
1 : 2);
3629 if ((c
->closes
== 0) && (c
->type
== CHAN_X11
)) {
3630 logevent("Forwarded X11 connection terminated");
3631 assert(c
->u
.x11
.s
!= NULL
);
3632 x11_close(c
->u
.x11
.s
);
3635 if ((c
->closes
== 0) && (c
->type
== CHAN_SOCKDATA
)) {
3636 logevent("Forwarded port closed");
3637 assert(c
->u
.pfd
.s
!= NULL
);
3638 pfd_close(c
->u
.pfd
.s
);
3642 c
->closes
|= (closetype
<< 2); /* seen this message */
3643 if (!(c
->closes
& closetype
)) {
3644 send_packet(ssh
, ssh
->pktin
.type
, PKT_INT
, c
->remoteid
,
3646 c
->closes
|= closetype
; /* sent it too */
3649 if (c
->closes
== 15) {
3650 del234(ssh
->channels
, c
);
3654 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
3655 ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
"" :
3656 "_CONFIRMATION", c ?
"half-open" : "nonexistent",
3660 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_DATA
) {
3661 /* Data sent down one of our channels. */
3662 int i
= GET_32BIT(ssh
->pktin
.body
);
3663 int len
= GET_32BIT(ssh
->pktin
.body
+ 4);
3664 unsigned char *p
= ssh
->pktin
.body
+ 8;
3665 struct ssh_channel
*c
;
3666 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
3671 bufsize
= x11_send(c
->u
.x11
.s
, (char *)p
, len
);
3674 bufsize
= pfd_send(c
->u
.pfd
.s
, (char *)p
, len
);
3677 /* Data for an agent message. Buffer it. */
3679 if (c
->u
.a
.lensofar
< 4) {
3680 int l
= min(4 - c
->u
.a
.lensofar
, len
);
3681 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
,
3685 c
->u
.a
.lensofar
+= l
;
3687 if (c
->u
.a
.lensofar
== 4) {
3689 4 + GET_32BIT(c
->u
.a
.msglen
);
3690 c
->u
.a
.message
= snewn(c
->u
.a
.totallen
,
3692 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
3694 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
3696 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
3698 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
,
3702 c
->u
.a
.lensofar
+= l
;
3704 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
3707 if (agent_query(c
->u
.a
.message
,
3710 ssh_agentf_callback
, c
))
3711 ssh_agentf_callback(c
, reply
, replylen
);
3712 sfree(c
->u
.a
.message
);
3713 c
->u
.a
.lensofar
= 0;
3716 bufsize
= 0; /* agent channels never back up */
3719 if (!c
->v
.v1
.throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
3720 c
->v
.v1
.throttling
= 1;
3721 ssh1_throttle(ssh
, +1);
3724 } else if (ssh
->pktin
.type
== SSH1_SMSG_SUCCESS
) {
3725 /* may be from EXEC_SHELL on some servers */
3726 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3727 /* may be from EXEC_SHELL on some servers
3728 * if no pty is available or in other odd cases. Ignore */
3729 } else if (ssh
->pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
3731 ssh
->exitcode
= GET_32BIT(ssh
->pktin
.body
);
3732 sprintf(buf
, "Server sent command exit status %d",
3735 send_packet(ssh
, SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
3737 * In case `helpful' firewalls or proxies tack
3738 * extra human-readable text on the end of the
3739 * session which we might mistake for another
3740 * encrypted packet, we close the session once
3741 * we've sent EXIT_CONFIRMATION.
3743 ssh_closing((Plug
)ssh
, NULL
, 0, 0);
3746 bombout(("Strange packet received: type %d", ssh
->pktin
.type
));
3751 int len
= min(inlen
, 512);
3752 send_packet(ssh
, SSH1_CMSG_STDIN_DATA
,
3753 PKT_INT
, len
, PKT_DATA
, in
, len
, PKT_END
);
3764 * Utility routine for decoding comma-separated strings in KEXINIT.
3766 static int in_commasep_string(char *needle
, char *haystack
, int haylen
)
3769 if (!needle
|| !haystack
) /* protect against null pointers */
3771 needlen
= strlen(needle
);
3774 * Is it at the start of the string?
3776 if (haylen
>= needlen
&& /* haystack is long enough */
3777 !memcmp(needle
, haystack
, needlen
) && /* initial match */
3778 (haylen
== needlen
|| haystack
[needlen
] == ',')
3779 /* either , or EOS follows */
3783 * If not, search for the next comma and resume after that.
3784 * If no comma found, terminate.
3786 while (haylen
> 0 && *haystack
!= ',')
3787 haylen
--, haystack
++;
3790 haylen
--, haystack
++; /* skip over comma itself */
3795 * SSH2 key creation method.
3797 static void ssh2_mkkey(Ssh ssh
, Bignum K
, unsigned char *H
,
3798 unsigned char *sessid
, char chr
,
3799 unsigned char *keyspace
)
3802 /* First 20 bytes. */
3804 if (!(ssh
->remote_bugs
& BUG_SSH2_DERIVEKEY
))
3806 SHA_Bytes(&s
, H
, 20);
3807 SHA_Bytes(&s
, &chr
, 1);
3808 SHA_Bytes(&s
, sessid
, 20);
3809 SHA_Final(&s
, keyspace
);
3810 /* Next 20 bytes. */
3812 if (!(ssh
->remote_bugs
& BUG_SSH2_DERIVEKEY
))
3814 SHA_Bytes(&s
, H
, 20);
3815 SHA_Bytes(&s
, keyspace
, 20);
3816 SHA_Final(&s
, keyspace
+ 20);
3820 * Handle the SSH2 transport layer.
3822 static int do_ssh2_transport(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
3824 struct do_ssh2_transport_state
{
3825 int nbits
, pbits
, warn
;
3826 Bignum p
, g
, e
, f
, K
;
3827 int kex_init_value
, kex_reply_value
;
3828 const struct ssh_mac
**maclist
;
3830 const struct ssh2_cipher
*cscipher_tobe
;
3831 const struct ssh2_cipher
*sccipher_tobe
;
3832 const struct ssh_mac
*csmac_tobe
;
3833 const struct ssh_mac
*scmac_tobe
;
3834 const struct ssh_compress
*cscomp_tobe
;
3835 const struct ssh_compress
*sccomp_tobe
;
3836 char *hostkeydata
, *sigdata
, *keystr
, *fingerprint
;
3837 int hostkeylen
, siglen
;
3838 void *hkey
; /* actual host key */
3839 unsigned char exchange_hash
[20];
3840 int n_preferred_ciphers
;
3841 const struct ssh2_ciphers
*preferred_ciphers
[CIPHER_MAX
];
3842 const struct ssh_compress
*preferred_comp
;
3845 crState(do_ssh2_transport_state
);
3847 crBegin(ssh
->do_ssh2_transport_crstate
);
3849 s
->cscipher_tobe
= s
->sccipher_tobe
= NULL
;
3850 s
->csmac_tobe
= s
->scmac_tobe
= NULL
;
3851 s
->cscomp_tobe
= s
->sccomp_tobe
= NULL
;
3859 * Set up the preferred ciphers. (NULL => warn below here)
3861 s
->n_preferred_ciphers
= 0;
3862 for (i
= 0; i
< CIPHER_MAX
; i
++) {
3863 switch (ssh
->cfg
.ssh_cipherlist
[i
]) {
3864 case CIPHER_BLOWFISH
:
3865 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_blowfish
;
3868 if (ssh
->cfg
.ssh2_des_cbc
) {
3869 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_des
;
3873 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_3des
;
3876 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_aes
;
3879 /* Flag for later. Don't bother if it's the last in
3881 if (i
< CIPHER_MAX
- 1) {
3882 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = NULL
;
3890 * Set up preferred compression.
3892 if (ssh
->cfg
.compression
)
3893 s
->preferred_comp
= &ssh_zlib
;
3895 s
->preferred_comp
= &ssh_comp_none
;
3898 * Be prepared to work around the buggy MAC problem.
3900 if (ssh
->remote_bugs
& BUG_SSH2_HMAC
)
3901 s
->maclist
= buggymacs
, s
->nmacs
= lenof(buggymacs
);
3903 s
->maclist
= macs
, s
->nmacs
= lenof(macs
);
3907 int i
, j
, cipherstr_started
;
3910 * Construct and send our key exchange packet.
3912 ssh2_pkt_init(ssh
, SSH2_MSG_KEXINIT
);
3913 for (i
= 0; i
< 16; i
++)
3914 ssh2_pkt_addbyte(ssh
, (unsigned char) random_byte());
3915 /* List key exchange algorithms. */
3916 ssh2_pkt_addstring_start(ssh
);
3917 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3918 if (kex_algs
[i
] == &ssh_diffiehellman_gex
&&
3919 (ssh
->remote_bugs
& BUG_SSH2_DH_GEX
))
3921 ssh2_pkt_addstring_str(ssh
, kex_algs
[i
]->name
);
3922 if (i
< lenof(kex_algs
) - 1)
3923 ssh2_pkt_addstring_str(ssh
, ",");
3925 /* List server host key algorithms. */
3926 ssh2_pkt_addstring_start(ssh
);
3927 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3928 ssh2_pkt_addstring_str(ssh
, hostkey_algs
[i
]->name
);
3929 if (i
< lenof(hostkey_algs
) - 1)
3930 ssh2_pkt_addstring_str(ssh
, ",");
3932 /* List client->server encryption algorithms. */
3933 ssh2_pkt_addstring_start(ssh
);
3934 cipherstr_started
= 0;
3935 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
3936 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
3937 if (!c
) continue; /* warning flag */
3938 for (j
= 0; j
< c
->nciphers
; j
++) {
3939 if (cipherstr_started
)
3940 ssh2_pkt_addstring_str(ssh
, ",");
3941 ssh2_pkt_addstring_str(ssh
, c
->list
[j
]->name
);
3942 cipherstr_started
= 1;
3945 /* List server->client encryption algorithms. */
3946 ssh2_pkt_addstring_start(ssh
);
3947 cipherstr_started
= 0;
3948 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
3949 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
3950 if (!c
) continue; /* warning flag */
3951 for (j
= 0; j
< c
->nciphers
; j
++) {
3952 if (cipherstr_started
)
3953 ssh2_pkt_addstring_str(ssh
, ",");
3954 ssh2_pkt_addstring_str(ssh
, c
->list
[j
]->name
);
3955 cipherstr_started
= 1;
3958 /* List client->server MAC algorithms. */
3959 ssh2_pkt_addstring_start(ssh
);
3960 for (i
= 0; i
< s
->nmacs
; i
++) {
3961 ssh2_pkt_addstring_str(ssh
, s
->maclist
[i
]->name
);
3962 if (i
< s
->nmacs
- 1)
3963 ssh2_pkt_addstring_str(ssh
, ",");
3965 /* List server->client MAC algorithms. */
3966 ssh2_pkt_addstring_start(ssh
);
3967 for (i
= 0; i
< s
->nmacs
; i
++) {
3968 ssh2_pkt_addstring_str(ssh
, s
->maclist
[i
]->name
);
3969 if (i
< s
->nmacs
- 1)
3970 ssh2_pkt_addstring_str(ssh
, ",");
3972 /* List client->server compression algorithms. */
3973 ssh2_pkt_addstring_start(ssh
);
3974 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3975 const struct ssh_compress
*c
=
3976 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
3977 ssh2_pkt_addstring_str(ssh
, c
->name
);
3978 if (i
< lenof(compressions
))
3979 ssh2_pkt_addstring_str(ssh
, ",");
3981 /* List server->client compression algorithms. */
3982 ssh2_pkt_addstring_start(ssh
);
3983 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3984 const struct ssh_compress
*c
=
3985 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
3986 ssh2_pkt_addstring_str(ssh
, c
->name
);
3987 if (i
< lenof(compressions
))
3988 ssh2_pkt_addstring_str(ssh
, ",");
3990 /* List client->server languages. Empty list. */
3991 ssh2_pkt_addstring_start(ssh
);
3992 /* List server->client languages. Empty list. */
3993 ssh2_pkt_addstring_start(ssh
);
3994 /* First KEX packet does _not_ follow, because we're not that brave. */
3995 ssh2_pkt_addbool(ssh
, FALSE
);
3997 ssh2_pkt_adduint32(ssh
, 0);
4000 ssh
->exhash
= ssh
->exhashbase
;
4001 sha_string(&ssh
->exhash
, ssh
->pktout
.data
+ 5, ssh
->pktout
.length
- 5);
4007 if (ssh
->pktin
.length
> 5)
4008 sha_string(&ssh
->exhash
, ssh
->pktin
.data
+ 5, ssh
->pktin
.length
- 5);
4011 * Now examine the other side's KEXINIT to see what we're up
4018 if (ssh
->pktin
.type
!= SSH2_MSG_KEXINIT
) {
4019 bombout(("expected key exchange packet from server"));
4023 ssh
->hostkey
= NULL
;
4024 s
->cscipher_tobe
= NULL
;
4025 s
->sccipher_tobe
= NULL
;
4026 s
->csmac_tobe
= NULL
;
4027 s
->scmac_tobe
= NULL
;
4028 s
->cscomp_tobe
= NULL
;
4029 s
->sccomp_tobe
= NULL
;
4030 ssh
->pktin
.savedpos
+= 16; /* skip garbage cookie */
4031 ssh2_pkt_getstring(ssh
, &str
, &len
); /* key exchange algorithms */
4032 for (i
= 0; i
< lenof(kex_algs
); i
++) {
4033 if (kex_algs
[i
] == &ssh_diffiehellman_gex
&&
4034 (ssh
->remote_bugs
& BUG_SSH2_DH_GEX
))
4036 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
4037 ssh
->kex
= kex_algs
[i
];
4041 ssh2_pkt_getstring(ssh
, &str
, &len
); /* host key algorithms */
4042 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
4043 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
4044 ssh
->hostkey
= hostkey_algs
[i
];
4048 ssh2_pkt_getstring(ssh
, &str
, &len
); /* client->server cipher */
4050 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
4051 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
4055 for (j
= 0; j
< c
->nciphers
; j
++) {
4056 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
4057 s
->cscipher_tobe
= c
->list
[j
];
4062 if (s
->cscipher_tobe
) {
4064 askcipher(ssh
->frontend
, s
->cscipher_tobe
->name
, 1);
4068 if (!s
->cscipher_tobe
) {
4069 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
4070 str ? str
: "(null)"));
4074 ssh2_pkt_getstring(ssh
, &str
, &len
); /* server->client cipher */
4076 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
4077 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
4081 for (j
= 0; j
< c
->nciphers
; j
++) {
4082 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
4083 s
->sccipher_tobe
= c
->list
[j
];
4088 if (s
->sccipher_tobe
) {
4090 askcipher(ssh
->frontend
, s
->sccipher_tobe
->name
, 2);
4094 if (!s
->sccipher_tobe
) {
4095 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
4096 str ? str
: "(null)"));
4100 ssh2_pkt_getstring(ssh
, &str
, &len
); /* client->server mac */
4101 for (i
= 0; i
< s
->nmacs
; i
++) {
4102 if (in_commasep_string(s
->maclist
[i
]->name
, str
, len
)) {
4103 s
->csmac_tobe
= s
->maclist
[i
];
4107 ssh2_pkt_getstring(ssh
, &str
, &len
); /* server->client mac */
4108 for (i
= 0; i
< s
->nmacs
; i
++) {
4109 if (in_commasep_string(s
->maclist
[i
]->name
, str
, len
)) {
4110 s
->scmac_tobe
= s
->maclist
[i
];
4114 ssh2_pkt_getstring(ssh
, &str
, &len
); /* client->server compression */
4115 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
4116 const struct ssh_compress
*c
=
4117 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
4118 if (in_commasep_string(c
->name
, str
, len
)) {
4123 ssh2_pkt_getstring(ssh
, &str
, &len
); /* server->client compression */
4124 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
4125 const struct ssh_compress
*c
=
4126 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
4127 if (in_commasep_string(c
->name
, str
, len
)) {
4135 * Work out the number of bits of key we will need from the key
4136 * exchange. We start with the maximum key length of either
4142 csbits
= s
->cscipher_tobe
->keylen
;
4143 scbits
= s
->sccipher_tobe
->keylen
;
4144 s
->nbits
= (csbits
> scbits ? csbits
: scbits
);
4146 /* The keys only have 160-bit entropy, since they're based on
4147 * a SHA-1 hash. So cap the key size at 160 bits. */
4152 * If we're doing Diffie-Hellman group exchange, start by
4153 * requesting a group.
4155 if (ssh
->kex
== &ssh_diffiehellman_gex
) {
4156 logevent("Doing Diffie-Hellman group exchange");
4157 ssh
->pkt_ctx
|= SSH2_PKTCTX_DHGEX
;
4159 * Work out how big a DH group we will need to allow that
4162 s
->pbits
= 512 << ((s
->nbits
- 1) / 64);
4163 ssh2_pkt_init(ssh
, SSH2_MSG_KEX_DH_GEX_REQUEST
);
4164 ssh2_pkt_adduint32(ssh
, s
->pbits
);
4168 if (ssh
->pktin
.type
!= SSH2_MSG_KEX_DH_GEX_GROUP
) {
4169 bombout(("expected key exchange group packet from server"));
4172 s
->p
= ssh2_pkt_getmp(ssh
);
4173 s
->g
= ssh2_pkt_getmp(ssh
);
4174 ssh
->kex_ctx
= dh_setup_group(s
->p
, s
->g
);
4175 s
->kex_init_value
= SSH2_MSG_KEX_DH_GEX_INIT
;
4176 s
->kex_reply_value
= SSH2_MSG_KEX_DH_GEX_REPLY
;
4178 ssh
->pkt_ctx
|= SSH2_PKTCTX_DHGROUP1
;
4179 ssh
->kex_ctx
= dh_setup_group1();
4180 s
->kex_init_value
= SSH2_MSG_KEXDH_INIT
;
4181 s
->kex_reply_value
= SSH2_MSG_KEXDH_REPLY
;
4184 logevent("Doing Diffie-Hellman key exchange");
4186 * Now generate and send e for Diffie-Hellman.
4188 s
->e
= dh_create_e(ssh
->kex_ctx
, s
->nbits
* 2);
4189 ssh2_pkt_init(ssh
, s
->kex_init_value
);
4190 ssh2_pkt_addmp(ssh
, s
->e
);
4194 if (ssh
->pktin
.type
!= s
->kex_reply_value
) {
4195 bombout(("expected key exchange reply packet from server"));
4198 ssh2_pkt_getstring(ssh
, &s
->hostkeydata
, &s
->hostkeylen
);
4199 s
->f
= ssh2_pkt_getmp(ssh
);
4200 ssh2_pkt_getstring(ssh
, &s
->sigdata
, &s
->siglen
);
4202 s
->K
= dh_find_K(ssh
->kex_ctx
, s
->f
);
4204 sha_string(&ssh
->exhash
, s
->hostkeydata
, s
->hostkeylen
);
4205 if (ssh
->kex
== &ssh_diffiehellman_gex
) {
4206 sha_uint32(&ssh
->exhash
, s
->pbits
);
4207 sha_mpint(&ssh
->exhash
, s
->p
);
4208 sha_mpint(&ssh
->exhash
, s
->g
);
4210 sha_mpint(&ssh
->exhash
, s
->e
);
4211 sha_mpint(&ssh
->exhash
, s
->f
);
4212 sha_mpint(&ssh
->exhash
, s
->K
);
4213 SHA_Final(&ssh
->exhash
, s
->exchange_hash
);
4215 dh_cleanup(ssh
->kex_ctx
);
4216 ssh
->kex_ctx
= NULL
;
4219 debug(("Exchange hash is:\n"));
4220 dmemdump(s
->exchange_hash
, 20);
4223 s
->hkey
= ssh
->hostkey
->newkey(s
->hostkeydata
, s
->hostkeylen
);
4225 !ssh
->hostkey
->verifysig(s
->hkey
, s
->sigdata
, s
->siglen
,
4226 (char *)s
->exchange_hash
, 20)) {
4227 bombout(("Server's host key did not match the signature supplied"));
4232 * Authenticate remote host: verify host key. (We've already
4233 * checked the signature of the exchange hash.)
4235 s
->keystr
= ssh
->hostkey
->fmtkey(s
->hkey
);
4236 s
->fingerprint
= ssh
->hostkey
->fingerprint(s
->hkey
);
4237 verify_ssh_host_key(ssh
->frontend
,
4238 ssh
->savedhost
, ssh
->savedport
, ssh
->hostkey
->keytype
,
4239 s
->keystr
, s
->fingerprint
);
4240 if (s
->first_kex
) { /* don't bother logging this in rekeys */
4241 logevent("Host key fingerprint is:");
4242 logevent(s
->fingerprint
);
4244 sfree(s
->fingerprint
);
4246 ssh
->hostkey
->freekey(s
->hkey
);
4249 * Send SSH2_MSG_NEWKEYS.
4251 ssh2_pkt_init(ssh
, SSH2_MSG_NEWKEYS
);
4255 * Expect SSH2_MSG_NEWKEYS from server.
4258 if (ssh
->pktin
.type
!= SSH2_MSG_NEWKEYS
) {
4259 bombout(("expected new-keys packet from server"));
4264 * Create and initialise session keys.
4266 if (ssh
->cs_cipher_ctx
)
4267 ssh
->cscipher
->free_context(ssh
->cs_cipher_ctx
);
4268 ssh
->cscipher
= s
->cscipher_tobe
;
4269 ssh
->cs_cipher_ctx
= ssh
->cscipher
->make_context();
4271 if (ssh
->sc_cipher_ctx
)
4272 ssh
->sccipher
->free_context(ssh
->sc_cipher_ctx
);
4273 ssh
->sccipher
= s
->sccipher_tobe
;
4274 ssh
->sc_cipher_ctx
= ssh
->sccipher
->make_context();
4276 if (ssh
->cs_mac_ctx
)
4277 ssh
->csmac
->free_context(ssh
->cs_mac_ctx
);
4278 ssh
->csmac
= s
->csmac_tobe
;
4279 ssh
->cs_mac_ctx
= ssh
->csmac
->make_context();
4281 if (ssh
->sc_mac_ctx
)
4282 ssh
->scmac
->free_context(ssh
->sc_mac_ctx
);
4283 ssh
->scmac
= s
->scmac_tobe
;
4284 ssh
->sc_mac_ctx
= ssh
->scmac
->make_context();
4286 if (ssh
->cs_comp_ctx
)
4287 ssh
->cscomp
->compress_cleanup(ssh
->cs_comp_ctx
);
4288 ssh
->cscomp
= s
->cscomp_tobe
;
4289 ssh
->cs_comp_ctx
= ssh
->cscomp
->compress_init();
4291 if (ssh
->sc_comp_ctx
)
4292 ssh
->sccomp
->decompress_cleanup(ssh
->sc_comp_ctx
);
4293 ssh
->sccomp
= s
->sccomp_tobe
;
4294 ssh
->sc_comp_ctx
= ssh
->sccomp
->decompress_init();
4297 * Set IVs after keys. Here we use the exchange hash from the
4298 * _first_ key exchange.
4301 unsigned char keyspace
[40];
4303 memcpy(ssh
->v2_session_id
, s
->exchange_hash
,
4304 sizeof(s
->exchange_hash
));
4305 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'C',keyspace
);
4306 ssh
->cscipher
->setkey(ssh
->cs_cipher_ctx
, keyspace
);
4307 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'D',keyspace
);
4308 ssh
->sccipher
->setkey(ssh
->sc_cipher_ctx
, keyspace
);
4309 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'A',keyspace
);
4310 ssh
->cscipher
->setiv(ssh
->cs_cipher_ctx
, keyspace
);
4311 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'B',keyspace
);
4312 ssh
->sccipher
->setiv(ssh
->sc_cipher_ctx
, keyspace
);
4313 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'E',keyspace
);
4314 ssh
->csmac
->setkey(ssh
->cs_mac_ctx
, keyspace
);
4315 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'F',keyspace
);
4316 ssh
->scmac
->setkey(ssh
->sc_mac_ctx
, keyspace
);
4318 logeventf(ssh
, "Initialised %.200s client->server encryption",
4319 ssh
->cscipher
->text_name
);
4320 logeventf(ssh
, "Initialised %.200s server->client encryption",
4321 ssh
->sccipher
->text_name
);
4322 if (ssh
->cscomp
->text_name
)
4323 logeventf(ssh
, "Initialised %s compression",
4324 ssh
->cscomp
->text_name
);
4325 if (ssh
->sccomp
->text_name
)
4326 logeventf(ssh
, "Initialised %s decompression",
4327 ssh
->sccomp
->text_name
);
4330 * If this is the first key exchange phase, we must pass the
4331 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4332 * wants to see it but because it will need time to initialise
4333 * itself before it sees an actual packet. In subsequent key
4334 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4335 * it would only confuse the layer above.
4337 if (!s
->first_kex
) {
4343 * Now we're encrypting. Begin returning 1 to the protocol main
4344 * function so that other things can run on top of the
4345 * transport. If we ever see a KEXINIT, we must go back to the
4348 while (!(ispkt
&& ssh
->pktin
.type
== SSH2_MSG_KEXINIT
)) {
4351 logevent("Server initiated key re-exchange");
4352 goto begin_key_exchange
;
4358 * Add data to an SSH2 channel output buffer.
4360 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
4363 bufchain_add(&c
->v
.v2
.outbuffer
, buf
, len
);
4367 * Attempt to send data on an SSH2 channel.
4369 static int ssh2_try_send(struct ssh_channel
*c
)
4373 while (c
->v
.v2
.remwindow
> 0 && bufchain_size(&c
->v
.v2
.outbuffer
) > 0) {
4376 bufchain_prefix(&c
->v
.v2
.outbuffer
, &data
, &len
);
4377 if ((unsigned)len
> c
->v
.v2
.remwindow
)
4378 len
= c
->v
.v2
.remwindow
;
4379 if ((unsigned)len
> c
->v
.v2
.remmaxpkt
)
4380 len
= c
->v
.v2
.remmaxpkt
;
4381 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_DATA
);
4382 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
4383 ssh2_pkt_addstring_start(ssh
);
4384 ssh2_pkt_addstring_data(ssh
, data
, len
);
4386 bufchain_consume(&c
->v
.v2
.outbuffer
, len
);
4387 c
->v
.v2
.remwindow
-= len
;
4391 * After having sent as much data as we can, return the amount
4394 return bufchain_size(&c
->v
.v2
.outbuffer
);
4398 * Potentially enlarge the window on an SSH2 channel.
4400 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
)
4405 * Never send WINDOW_ADJUST for a channel that the remote side
4406 * already thinks it's closed; there's no point, since it won't
4407 * be sending any more data anyway.
4412 if (newwin
> c
->v
.v2
.locwindow
) {
4413 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4414 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
4415 ssh2_pkt_adduint32(ssh
, newwin
- c
->v
.v2
.locwindow
);
4417 c
->v
.v2
.locwindow
= newwin
;
4422 * Handle the SSH2 userauth and connection layers.
4424 static void do_ssh2_authconn(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
4426 struct do_ssh2_authconn_state
{
4428 AUTH_INVALID
, AUTH_PUBLICKEY_AGENT
, AUTH_PUBLICKEY_FILE
,
4430 AUTH_KEYBOARD_INTERACTIVE
4434 AUTH_TYPE_PUBLICKEY
,
4435 AUTH_TYPE_PUBLICKEY_OFFER_LOUD
,
4436 AUTH_TYPE_PUBLICKEY_OFFER_QUIET
,
4438 AUTH_TYPE_KEYBOARD_INTERACTIVE
,
4439 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4441 int gotit
, need_pw
, can_pubkey
, can_passwd
, can_keyb_inter
;
4442 int tried_pubkey_config
, tried_agent
, tried_keyb_inter
;
4443 int kbd_inter_running
;
4445 int num_prompts
, curr_prompt
, echo
;
4450 void *publickey_blob
;
4451 int publickey_bloblen
;
4452 unsigned char request
[5], *response
, *p
;
4456 char *pkblob
, *alg
, *commentp
;
4457 int pklen
, alglen
, commentlen
;
4458 int siglen
, retlen
, len
;
4459 char *q
, *agentreq
, *ret
;
4462 crState(do_ssh2_authconn_state
);
4464 crBegin(ssh
->do_ssh2_authconn_crstate
);
4467 * Request userauth protocol, and await a response to it.
4469 ssh2_pkt_init(ssh
, SSH2_MSG_SERVICE_REQUEST
);
4470 ssh2_pkt_addstring(ssh
, "ssh-userauth");
4472 crWaitUntilV(ispkt
);
4473 if (ssh
->pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
) {
4474 bombout(("Server refused user authentication protocol"));
4479 * We repeat this whole loop, including the username prompt,
4480 * until we manage a successful authentication. If the user
4481 * types the wrong _password_, they can be sent back to the
4482 * beginning to try another username, if this is configured on.
4483 * (If they specify a username in the config, they are never
4484 * asked, even if they do give a wrong password.)
4486 * I think this best serves the needs of
4488 * - the people who have no configuration, no keys, and just
4489 * want to try repeated (username,password) pairs until they
4490 * type both correctly
4492 * - people who have keys and configuration but occasionally
4493 * need to fall back to passwords
4495 * - people with a key held in Pageant, who might not have
4496 * logged in to a particular machine before; so they want to
4497 * type a username, and then _either_ their key will be
4498 * accepted, _or_ they will type a password. If they mistype
4499 * the username they will want to be able to get back and
4502 s
->username
[0] = '\0';
4503 s
->got_username
= FALSE
;
4508 if (s
->got_username
&& !ssh
->cfg
.change_username
) {
4510 * We got a username last time round this loop, and
4511 * with change_username turned off we don't try to get
4514 } else if ((flags
& FLAG_INTERACTIVE
) && !*ssh
->cfg
.username
) {
4515 if (ssh_get_line
&& !ssh_getline_pw_only
) {
4516 if (!ssh_get_line("login as: ",
4517 s
->username
, sizeof(s
->username
), FALSE
)) {
4519 * get_line failed to get a username.
4522 logevent("No username provided. Abandoning session.");
4523 ssh_closing((Plug
)ssh
, NULL
, 0, 0);
4527 int ret
; /* need not be saved across crReturn */
4528 c_write_str(ssh
, "login as: ");
4530 setup_userpass_input(ssh
, s
->username
, sizeof(s
->username
), 1);
4532 crWaitUntilV(!ispkt
);
4533 ret
= process_userpass_input(ssh
, in
, inlen
);
4537 c_write_str(ssh
, "\r\n");
4539 s
->username
[strcspn(s
->username
, "\n\r")] = '\0';
4542 strncpy(s
->username
, ssh
->cfg
.username
, sizeof(s
->username
));
4543 s
->username
[sizeof(s
->username
)-1] = '\0';
4544 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
4545 stuff
= dupprintf("Using username \"%s\".\r\n", s
->username
);
4546 c_write_str(ssh
, stuff
);
4550 s
->got_username
= TRUE
;
4553 * Send an authentication request using method "none": (a)
4554 * just in case it succeeds, and (b) so that we know what
4555 * authentication methods we can usefully try next.
4557 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4559 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4560 ssh2_pkt_addstring(ssh
, s
->username
);
4561 ssh2_pkt_addstring(ssh
, "ssh-connection");/* service requested */
4562 ssh2_pkt_addstring(ssh
, "none"); /* method */
4564 s
->type
= AUTH_TYPE_NONE
;
4566 s
->we_are_in
= FALSE
;
4568 s
->tried_pubkey_config
= FALSE
;
4569 s
->tried_agent
= FALSE
;
4570 s
->tried_keyb_inter
= FALSE
;
4571 s
->kbd_inter_running
= FALSE
;
4572 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
4573 if (!filename_is_null(ssh
->cfg
.keyfile
)) {
4575 logeventf(ssh
, "Reading private key file \"%.150s\"",
4576 filename_to_str(&ssh
->cfg
.keyfile
));
4577 keytype
= key_type(&ssh
->cfg
.keyfile
);
4578 if (keytype
== SSH_KEYTYPE_SSH2
) {
4580 ssh2_userkey_loadpub(&ssh
->cfg
.keyfile
, NULL
,
4581 &s
->publickey_bloblen
);
4584 logeventf(ssh
, "Unable to use this key file (%s)",
4585 key_type_to_str(keytype
));
4586 msgbuf
= dupprintf("Unable to use key file \"%.150s\""
4588 filename_to_str(&ssh
->cfg
.keyfile
),
4589 key_type_to_str(keytype
));
4590 c_write_str(ssh
, msgbuf
);
4592 s
->publickey_blob
= NULL
;
4595 s
->publickey_blob
= NULL
;
4599 * Wait for the result of the last authentication request.
4602 crWaitUntilV(ispkt
);
4603 while (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_BANNER
) {
4607 * Don't show the banner if we're operating in
4608 * non-verbose non-interactive mode. (It's probably
4609 * a script, which means nobody will read the
4610 * banner _anyway_, and moreover the printing of
4611 * the banner will screw up processing on the
4612 * output of (say) plink.)
4614 if (flags
& (FLAG_VERBOSE
| FLAG_INTERACTIVE
)) {
4615 ssh2_pkt_getstring(ssh
, &banner
, &size
);
4617 c_write_untrusted(ssh
, banner
, size
);
4619 crWaitUntilV(ispkt
);
4621 if (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_SUCCESS
) {
4622 logevent("Access granted");
4623 s
->we_are_in
= TRUE
;
4627 if (s
->kbd_inter_running
&&
4628 ssh
->pktin
.type
== SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4630 * This is either a further set-of-prompts packet
4631 * in keyboard-interactive authentication, or it's
4632 * the same one and we came back here with `gotit'
4633 * set. In the former case, we must reset the
4634 * curr_prompt variable.
4638 } else if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_FAILURE
) {
4639 bombout(("Strange packet received during authentication: type %d",
4647 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4648 * we can look at the string in it and know what we can
4649 * helpfully try next.
4651 if (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
) {
4654 ssh2_pkt_getstring(ssh
, &methods
, &methlen
);
4655 s
->kbd_inter_running
= FALSE
;
4656 if (!ssh2_pkt_getbool(ssh
)) {
4658 * We have received an unequivocal Access
4659 * Denied. This can translate to a variety of
4662 * - if we'd just tried "none" authentication,
4663 * it's not worth printing anything at all
4665 * - if we'd just tried a public key _offer_,
4666 * the message should be "Server refused our
4667 * key" (or no message at all if the key
4668 * came from Pageant)
4670 * - if we'd just tried anything else, the
4671 * message really should be "Access denied".
4673 * Additionally, if we'd just tried password
4674 * authentication, we should break out of this
4675 * whole loop so as to go back to the username
4678 if (s
->type
== AUTH_TYPE_NONE
) {
4680 } else if (s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
||
4681 s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_QUIET
) {
4682 if (s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
)
4683 c_write_str(ssh
, "Server refused our key\r\n");
4684 logevent("Server refused public key");
4685 } else if (s
->type
==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
) {
4686 /* server declined keyboard-interactive; ignore */
4688 c_write_str(ssh
, "Access denied\r\n");
4689 logevent("Access denied");
4690 if (s
->type
== AUTH_TYPE_PASSWORD
) {
4691 s
->we_are_in
= FALSE
;
4696 c_write_str(ssh
, "Further authentication required\r\n");
4697 logevent("Further authentication required");
4701 in_commasep_string("publickey", methods
, methlen
);
4703 in_commasep_string("password", methods
, methlen
);
4704 s
->can_keyb_inter
= ssh
->cfg
.try_ki_auth
&&
4705 in_commasep_string("keyboard-interactive", methods
, methlen
);
4709 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4712 * Most password/passphrase prompts will be
4713 * non-echoing, so we set this to 0 by default.
4714 * Exception is that some keyboard-interactive prompts
4715 * can be echoing, in which case we'll set this to 1.
4719 if (!s
->method
&& s
->can_pubkey
&&
4720 agent_exists() && !s
->tried_agent
) {
4722 * Attempt public-key authentication using Pageant.
4727 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4728 ssh
->pkt_ctx
|= SSH2_PKTCTX_PUBLICKEY
;
4730 s
->tried_agent
= TRUE
;
4732 logevent("Pageant is running. Requesting keys.");
4734 /* Request the keys held by the agent. */
4735 PUT_32BIT(s
->request
, 1);
4736 s
->request
[4] = SSH2_AGENTC_REQUEST_IDENTITIES
;
4737 if (!agent_query(s
->request
, 5, &r
, &s
->responselen
,
4738 ssh_agent_callback
, ssh
)) {
4742 bombout(("Unexpected data from server while"
4743 " waiting for agent response"));
4746 } while (ispkt
|| inlen
> 0);
4747 r
= ssh
->agent_response
;
4748 s
->responselen
= ssh
->agent_response_len
;
4750 s
->response
= (unsigned char *) r
;
4751 if (s
->response
&& s
->responselen
>= 5 &&
4752 s
->response
[4] == SSH2_AGENT_IDENTITIES_ANSWER
) {
4753 s
->p
= s
->response
+ 5;
4754 s
->nkeys
= GET_32BIT(s
->p
);
4758 sprintf(buf
, "Pageant has %d SSH2 keys", s
->nkeys
);
4761 for (s
->keyi
= 0; s
->keyi
< s
->nkeys
; s
->keyi
++) {
4766 sprintf(buf
, "Trying Pageant key #%d", s
->keyi
);
4769 s
->pklen
= GET_32BIT(s
->p
);
4771 if (s
->publickey_blob
&&
4772 s
->pklen
== s
->publickey_bloblen
&&
4773 !memcmp(s
->p
, s
->publickey_blob
,
4774 s
->publickey_bloblen
)) {
4775 logevent("This key matches configured key file");
4776 s
->tried_pubkey_config
= 1;
4778 s
->pkblob
= (char *)s
->p
;
4780 s
->alglen
= GET_32BIT(s
->pkblob
);
4781 s
->alg
= s
->pkblob
+ 4;
4782 s
->commentlen
= GET_32BIT(s
->p
);
4784 s
->commentp
= (char *)s
->p
;
4785 s
->p
+= s
->commentlen
;
4786 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4787 ssh2_pkt_addstring(ssh
, s
->username
);
4788 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4789 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4790 ssh2_pkt_addbool(ssh
, FALSE
); /* no signature included */
4791 ssh2_pkt_addstring_start(ssh
);
4792 ssh2_pkt_addstring_data(ssh
, s
->alg
, s
->alglen
);
4793 ssh2_pkt_addstring_start(ssh
);
4794 ssh2_pkt_addstring_data(ssh
, s
->pkblob
, s
->pklen
);
4797 crWaitUntilV(ispkt
);
4798 if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4799 logevent("Key refused");
4803 if (flags
& FLAG_VERBOSE
) {
4804 c_write_str(ssh
, "Authenticating with "
4806 c_write(ssh
, s
->commentp
, s
->commentlen
);
4807 c_write_str(ssh
, "\" from agent\r\n");
4811 * Server is willing to accept the key.
4812 * Construct a SIGN_REQUEST.
4814 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4815 ssh2_pkt_addstring(ssh
, s
->username
);
4816 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4817 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4818 ssh2_pkt_addbool(ssh
, TRUE
);
4819 ssh2_pkt_addstring_start(ssh
);
4820 ssh2_pkt_addstring_data(ssh
, s
->alg
, s
->alglen
);
4821 ssh2_pkt_addstring_start(ssh
);
4822 ssh2_pkt_addstring_data(ssh
, s
->pkblob
, s
->pklen
);
4824 s
->siglen
= ssh
->pktout
.length
- 5 + 4 + 20;
4825 if (ssh
->remote_bugs
& BUG_SSH2_PK_SESSIONID
)
4827 s
->len
= 1; /* message type */
4828 s
->len
+= 4 + s
->pklen
; /* key blob */
4829 s
->len
+= 4 + s
->siglen
; /* data to sign */
4830 s
->len
+= 4; /* flags */
4831 s
->agentreq
= snewn(4 + s
->len
, char);
4832 PUT_32BIT(s
->agentreq
, s
->len
);
4833 s
->q
= s
->agentreq
+ 4;
4834 *s
->q
++ = SSH2_AGENTC_SIGN_REQUEST
;
4835 PUT_32BIT(s
->q
, s
->pklen
);
4837 memcpy(s
->q
, s
->pkblob
, s
->pklen
);
4839 PUT_32BIT(s
->q
, s
->siglen
);
4841 /* Now the data to be signed... */
4842 if (!(ssh
->remote_bugs
& BUG_SSH2_PK_SESSIONID
)) {
4843 PUT_32BIT(s
->q
, 20);
4846 memcpy(s
->q
, ssh
->v2_session_id
, 20);
4848 memcpy(s
->q
, ssh
->pktout
.data
+ 5,
4849 ssh
->pktout
.length
- 5);
4850 s
->q
+= ssh
->pktout
.length
- 5;
4851 /* And finally the (zero) flags word. */
4853 if (!agent_query(s
->agentreq
, s
->len
+ 4,
4855 ssh_agent_callback
, ssh
)) {
4859 bombout(("Unexpected data from server"
4860 " while waiting for agent"
4864 } while (ispkt
|| inlen
> 0);
4865 vret
= ssh
->agent_response
;
4866 s
->retlen
= ssh
->agent_response_len
;
4871 if (s
->ret
[4] == SSH2_AGENT_SIGN_RESPONSE
) {
4872 logevent("Sending Pageant's response");
4873 ssh2_add_sigblob(ssh
, s
->pkblob
, s
->pklen
,
4875 GET_32BIT(s
->ret
+ 5));
4881 ("Pageant failed to answer challenge");
4891 if (!s
->method
&& s
->can_pubkey
&& s
->publickey_blob
4892 && !s
->tried_pubkey_config
) {
4893 unsigned char *pub_blob
;
4894 char *algorithm
, *comment
;
4897 s
->tried_pubkey_config
= TRUE
;
4899 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4900 ssh
->pkt_ctx
|= SSH2_PKTCTX_PUBLICKEY
;
4903 * Try the public key supplied in the configuration.
4905 * First, offer the public blob to see if the server is
4906 * willing to accept it.
4909 (unsigned char *)ssh2_userkey_loadpub(&ssh
->cfg
.keyfile
,
4913 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4914 ssh2_pkt_addstring(ssh
, s
->username
);
4915 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4916 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4917 ssh2_pkt_addbool(ssh
, FALSE
); /* no signature included */
4918 ssh2_pkt_addstring(ssh
, algorithm
);
4919 ssh2_pkt_addstring_start(ssh
);
4920 ssh2_pkt_addstring_data(ssh
, (char *)pub_blob
,
4923 logevent("Offered public key"); /* FIXME */
4925 crWaitUntilV(ispkt
);
4926 if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4928 s
->type
= AUTH_TYPE_PUBLICKEY_OFFER_LOUD
;
4929 continue; /* key refused; give up on it */
4932 logevent("Offer of public key accepted");
4934 * Actually attempt a serious authentication using
4937 if (ssh2_userkey_encrypted(&ssh
->cfg
.keyfile
, &comment
)) {
4938 sprintf(s
->pwprompt
,
4939 "Passphrase for key \"%.100s\": ",
4945 c_write_str(ssh
, "Authenticating with public key \"");
4946 c_write_str(ssh
, comment
);
4947 c_write_str(ssh
, "\"\r\n");
4948 s
->method
= AUTH_PUBLICKEY_FILE
;
4952 if (!s
->method
&& s
->can_keyb_inter
&& !s
->tried_keyb_inter
) {
4953 s
->method
= AUTH_KEYBOARD_INTERACTIVE
;
4954 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4955 s
->tried_keyb_inter
= TRUE
;
4957 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4958 ssh
->pkt_ctx
|= SSH2_PKTCTX_KBDINTER
;
4960 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4961 ssh2_pkt_addstring(ssh
, s
->username
);
4962 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4963 ssh2_pkt_addstring(ssh
, "keyboard-interactive"); /* method */
4964 ssh2_pkt_addstring(ssh
, ""); /* lang */
4965 ssh2_pkt_addstring(ssh
, "");
4968 crWaitUntilV(ispkt
);
4969 if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4970 if (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
)
4972 logevent("Keyboard-interactive authentication refused");
4973 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
;
4977 s
->kbd_inter_running
= TRUE
;
4981 if (s
->kbd_inter_running
) {
4982 s
->method
= AUTH_KEYBOARD_INTERACTIVE
;
4983 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4984 s
->tried_keyb_inter
= TRUE
;
4986 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4987 ssh
->pkt_ctx
|= SSH2_PKTCTX_KBDINTER
;
4989 if (s
->curr_prompt
== 0) {
4991 * We've got a fresh USERAUTH_INFO_REQUEST.
4992 * Display header data, and start going through
4995 char *name
, *inst
, *lang
;
4996 int name_len
, inst_len
, lang_len
;
4998 ssh2_pkt_getstring(ssh
, &name
, &name_len
);
4999 ssh2_pkt_getstring(ssh
, &inst
, &inst_len
);
5000 ssh2_pkt_getstring(ssh
, &lang
, &lang_len
);
5002 c_write_untrusted(ssh
, name
, name_len
);
5003 c_write_str(ssh
, "\r\n");
5006 c_write_untrusted(ssh
, inst
, inst_len
);
5007 c_write_str(ssh
, "\r\n");
5009 s
->num_prompts
= ssh2_pkt_getuint32(ssh
);
5013 * If there are prompts remaining in the packet,
5014 * display one and get a response.
5016 if (s
->curr_prompt
< s
->num_prompts
) {
5020 ssh2_pkt_getstring(ssh
, &prompt
, &prompt_len
);
5021 if (prompt_len
> 0) {
5022 strncpy(s
->pwprompt
, prompt
, sizeof(s
->pwprompt
));
5023 s
->pwprompt
[prompt_len
< sizeof(s
->pwprompt
) ?
5024 prompt_len
: sizeof(s
->pwprompt
)-1] = '\0';
5027 "<server failed to send prompt>: ");
5029 s
->echo
= ssh2_pkt_getbool(ssh
);
5035 if (!s
->method
&& s
->can_passwd
) {
5036 s
->method
= AUTH_PASSWORD
;
5037 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
5038 ssh
->pkt_ctx
|= SSH2_PKTCTX_PASSWORD
;
5039 sprintf(s
->pwprompt
, "%.90s@%.90s's password: ", s
->username
,
5046 if (!ssh_get_line(s
->pwprompt
, s
->password
,
5047 sizeof(s
->password
), TRUE
)) {
5049 * get_line failed to get a password (for
5050 * example because one was supplied on the
5051 * command line which has already failed to
5054 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
5055 ssh2_pkt_adduint32(ssh
,SSH2_DISCONNECT_BY_APPLICATION
);
5056 ssh2_pkt_addstring(ssh
, "No more passwords available"
5058 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5060 logevent("Unable to authenticate");
5061 connection_fatal(ssh
->frontend
,
5062 "Unable to authenticate");
5063 ssh_closing((Plug
)ssh
, NULL
, 0, 0);
5067 int ret
; /* need not be saved across crReturn */
5068 c_write_untrusted(ssh
, s
->pwprompt
, strlen(s
->pwprompt
));
5071 setup_userpass_input(ssh
, s
->password
,
5072 sizeof(s
->password
), s
->echo
);
5074 crWaitUntilV(!ispkt
);
5075 ret
= process_userpass_input(ssh
, in
, inlen
);
5079 c_write_str(ssh
, "\r\n");
5083 if (s
->method
== AUTH_PUBLICKEY_FILE
) {
5085 * We have our passphrase. Now try the actual authentication.
5087 struct ssh2_userkey
*key
;
5089 key
= ssh2_load_userkey(&ssh
->cfg
.keyfile
, s
->password
);
5090 if (key
== SSH2_WRONG_PASSPHRASE
|| key
== NULL
) {
5091 if (key
== SSH2_WRONG_PASSPHRASE
) {
5092 c_write_str(ssh
, "Wrong passphrase\r\n");
5093 s
->tried_pubkey_config
= FALSE
;
5095 c_write_str(ssh
, "Unable to load private key\r\n");
5096 s
->tried_pubkey_config
= TRUE
;
5098 /* Send a spurious AUTH_NONE to return to the top. */
5099 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
5100 ssh2_pkt_addstring(ssh
, s
->username
);
5101 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
5102 ssh2_pkt_addstring(ssh
, "none"); /* method */
5104 s
->type
= AUTH_TYPE_NONE
;
5106 unsigned char *pkblob
, *sigblob
, *sigdata
;
5107 int pkblob_len
, sigblob_len
, sigdata_len
;
5111 * We have loaded the private key and the server
5112 * has announced that it's willing to accept it.
5113 * Hallelujah. Generate a signature and send it.
5115 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
5116 ssh2_pkt_addstring(ssh
, s
->username
);
5117 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
5118 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
5119 ssh2_pkt_addbool(ssh
, TRUE
);
5120 ssh2_pkt_addstring(ssh
, key
->alg
->name
);
5121 pkblob
= key
->alg
->public_blob(key
->data
, &pkblob_len
);
5122 ssh2_pkt_addstring_start(ssh
);
5123 ssh2_pkt_addstring_data(ssh
, (char *)pkblob
, pkblob_len
);
5126 * The data to be signed is:
5130 * followed by everything so far placed in the
5133 sigdata_len
= ssh
->pktout
.length
- 5 + 4 + 20;
5134 if (ssh
->remote_bugs
& BUG_SSH2_PK_SESSIONID
)
5136 sigdata
= snewn(sigdata_len
, unsigned char);
5138 if (!(ssh
->remote_bugs
& BUG_SSH2_PK_SESSIONID
)) {
5139 PUT_32BIT(sigdata
+p
, 20);
5142 memcpy(sigdata
+p
, ssh
->v2_session_id
, 20); p
+= 20;
5143 memcpy(sigdata
+p
, ssh
->pktout
.data
+ 5,
5144 ssh
->pktout
.length
- 5);
5145 p
+= ssh
->pktout
.length
- 5;
5146 assert(p
== sigdata_len
);
5147 sigblob
= key
->alg
->sign(key
->data
, (char *)sigdata
,
5148 sigdata_len
, &sigblob_len
);
5149 ssh2_add_sigblob(ssh
, pkblob
, pkblob_len
,
5150 sigblob
, sigblob_len
);
5156 s
->type
= AUTH_TYPE_PUBLICKEY
;
5158 } else if (s
->method
== AUTH_PASSWORD
) {
5160 * We send the password packet lumped tightly together with
5161 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
5162 * string long enough to make the total length of the two
5163 * packets constant. This should ensure that a passive
5164 * listener doing traffic analyis can't work out the length
5167 * For this to work, we need an assumption about the
5168 * maximum length of the password packet. I think 256 is
5169 * pretty conservative. Anyone using a password longer than
5170 * that probably doesn't have much to worry about from
5171 * people who find out how long their password is!
5173 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
5174 ssh2_pkt_addstring(ssh
, s
->username
);
5175 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
5176 ssh2_pkt_addstring(ssh
, "password");
5177 ssh2_pkt_addbool(ssh
, FALSE
);
5178 ssh2_pkt_addstring(ssh
, s
->password
);
5179 memset(s
->password
, 0, sizeof(s
->password
));
5180 ssh2_pkt_defer(ssh
);
5182 * We'll include a string that's an exact multiple of the
5183 * cipher block size. If the cipher is NULL for some
5184 * reason, we don't do this trick at all because we gain
5187 if (ssh
->cscipher
) {
5190 stringlen
= (256 - ssh
->deferred_len
);
5191 stringlen
+= ssh
->cscipher
->blksize
- 1;
5192 stringlen
-= (stringlen
% ssh
->cscipher
->blksize
);
5195 * Temporarily disable actual compression,
5196 * so we can guarantee to get this string
5197 * exactly the length we want it. The
5198 * compression-disabling routine should
5199 * return an integer indicating how many
5200 * bytes we should adjust our string length
5204 ssh
->cscomp
->disable_compression(ssh
->cs_comp_ctx
);
5206 ssh2_pkt_init(ssh
, SSH2_MSG_IGNORE
);
5207 ssh2_pkt_addstring_start(ssh
);
5208 for (i
= 0; i
< stringlen
; i
++) {
5209 char c
= (char) random_byte();
5210 ssh2_pkt_addstring_data(ssh
, &c
, 1);
5212 ssh2_pkt_defer(ssh
);
5214 ssh_pkt_defersend(ssh
);
5215 logevent("Sent password");
5216 s
->type
= AUTH_TYPE_PASSWORD
;
5217 } else if (s
->method
== AUTH_KEYBOARD_INTERACTIVE
) {
5218 if (s
->curr_prompt
== 0) {
5219 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_INFO_RESPONSE
);
5220 ssh2_pkt_adduint32(ssh
, s
->num_prompts
);
5222 if (s
->need_pw
) { /* only add pw if we just got one! */
5223 ssh2_pkt_addstring(ssh
, s
->password
);
5224 memset(s
->password
, 0, sizeof(s
->password
));
5227 if (s
->curr_prompt
>= s
->num_prompts
) {
5231 * If there are prompts remaining, we set
5232 * `gotit' so that we won't attempt to get
5233 * another packet. Then we go back round the
5234 * loop and will end up retrieving another
5235 * prompt out of the existing packet. Funky or
5240 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
5242 c_write_str(ssh
, "No supported authentication methods"
5243 " left to try!\r\n");
5244 logevent("No supported authentications offered."
5246 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
5247 ssh2_pkt_adduint32(ssh
, SSH2_DISCONNECT_BY_APPLICATION
);
5248 ssh2_pkt_addstring(ssh
, "No supported authentication"
5249 " methods available");
5250 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5252 ssh_closing((Plug
)ssh
, NULL
, 0, 0);
5256 } while (!s
->we_are_in
);
5259 * Now we're authenticated for the connection protocol. The
5260 * connection protocol will automatically have started at this
5261 * point; there's no need to send SERVICE_REQUEST.
5265 * So now create a channel with a session in it.
5267 ssh
->channels
= newtree234(ssh_channelcmp
);
5268 ssh
->mainchan
= snew(struct ssh_channel
);
5269 ssh
->mainchan
->ssh
= ssh
;
5270 ssh
->mainchan
->localid
= alloc_channel_id(ssh
);
5271 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN
);
5272 ssh2_pkt_addstring(ssh
, "session");
5273 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->localid
);
5274 ssh
->mainchan
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5275 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->v
.v2
.locwindow
);/* our window size */
5276 ssh2_pkt_adduint32(ssh
, 0x4000UL
); /* our max pkt size */
5278 crWaitUntilV(ispkt
);
5279 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
5280 bombout(("Server refused to open a session"));
5282 /* FIXME: error data comes back in FAILURE packet */
5284 if (ssh2_pkt_getuint32(ssh
) != ssh
->mainchan
->localid
) {
5285 bombout(("Server's channel confirmation cited wrong channel"));
5288 ssh
->mainchan
->remoteid
= ssh2_pkt_getuint32(ssh
);
5289 ssh
->mainchan
->type
= CHAN_MAINSESSION
;
5290 ssh
->mainchan
->closes
= 0;
5291 ssh
->mainchan
->v
.v2
.remwindow
= ssh2_pkt_getuint32(ssh
);
5292 ssh
->mainchan
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32(ssh
);
5293 bufchain_init(&ssh
->mainchan
->v
.v2
.outbuffer
);
5294 add234(ssh
->channels
, ssh
->mainchan
);
5295 logevent("Opened channel for session");
5298 * Potentially enable X11 forwarding.
5300 if (ssh
->cfg
.x11_forward
) {
5301 char proto
[20], data
[64];
5302 logevent("Requesting X11 forwarding");
5303 ssh
->x11auth
= x11_invent_auth(proto
, sizeof(proto
),
5304 data
, sizeof(data
), ssh
->cfg
.x11_auth
);
5305 x11_get_real_auth(ssh
->x11auth
, ssh
->cfg
.x11_display
);
5306 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5307 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
5308 ssh2_pkt_addstring(ssh
, "x11-req");
5309 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5310 ssh2_pkt_addbool(ssh
, 0); /* many connections */
5311 ssh2_pkt_addstring(ssh
, proto
);
5312 ssh2_pkt_addstring(ssh
, data
);
5313 ssh2_pkt_adduint32(ssh
, x11_get_screen_number(ssh
->cfg
.x11_display
));
5317 crWaitUntilV(ispkt
);
5318 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5319 unsigned i
= ssh2_pkt_getuint32(ssh
);
5320 struct ssh_channel
*c
;
5321 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5323 continue; /* nonexistent channel */
5324 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5326 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5328 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5329 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5330 bombout(("Unexpected response to X11 forwarding request:"
5331 " packet type %d", ssh
->pktin
.type
));
5334 logevent("X11 forwarding refused");
5336 logevent("X11 forwarding enabled");
5337 ssh
->X11_fwd_enabled
= TRUE
;
5342 * Enable port forwardings.
5347 int sport
,dport
,sserv
,dserv
;
5348 char sports
[256], dports
[256], saddr
[256], host
[256];
5350 ssh
->rportfwds
= newtree234(ssh_rportcmp_ssh2
);
5351 /* Add port forwardings. */
5352 ssh
->portfwd_strptr
= ssh
->cfg
.portfwd
;
5353 while (*ssh
->portfwd_strptr
) {
5354 type
= *ssh
->portfwd_strptr
++;
5357 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= '\t') {
5358 if (*ssh
->portfwd_strptr
== ':') {
5360 * We've seen a colon in the middle of the
5361 * source port number. This means that
5362 * everything we've seen until now is the
5363 * source _address_, so we'll move it into
5364 * saddr and start sports from the beginning
5367 ssh
->portfwd_strptr
++;
5369 strcpy(saddr
, sports
);
5372 if (n
< 255) sports
[n
++] = *ssh
->portfwd_strptr
++;
5376 if (*ssh
->portfwd_strptr
== '\t')
5377 ssh
->portfwd_strptr
++;
5379 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= ':') {
5380 if (n
< 255) host
[n
++] = *ssh
->portfwd_strptr
++;
5383 if (*ssh
->portfwd_strptr
== ':')
5384 ssh
->portfwd_strptr
++;
5386 while (*ssh
->portfwd_strptr
) {
5387 if (n
< 255) dports
[n
++] = *ssh
->portfwd_strptr
++;
5390 ssh
->portfwd_strptr
++;
5391 dport
= atoi(dports
);
5395 dport
= net_service_lookup(dports
);
5397 logeventf(ssh
, "Service lookup failed for destination"
5398 " port \"%s\"", dports
);
5402 while (*ssh
->portfwd_strptr
) ssh
->portfwd_strptr
++;
5405 sport
= atoi(sports
);
5409 sport
= net_service_lookup(sports
);
5411 logeventf(ssh
, "Service lookup failed for source"
5412 " port \"%s\"", sports
);
5415 if (sport
&& dport
) {
5417 pfd_addforward(host
, dport
, *saddr ? saddr
: NULL
,
5418 sport
, ssh
, &ssh
->cfg
);
5419 logeventf(ssh
, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5420 " forwarding to %s:%.*s%.*s%d%.*s",
5421 (int)(*saddr?
strlen(saddr
):0), *saddr?saddr
:NULL
,
5422 (int)(*saddr?
1:0), ":",
5423 (int)(sserv ?
strlen(sports
) : 0), sports
,
5424 sserv
, "(", sport
, sserv
, ")",
5426 (int)(dserv ?
strlen(dports
) : 0), dports
,
5427 dserv
, "(", dport
, dserv
, ")");
5428 } else if (type
== 'D') {
5429 pfd_addforward(NULL
, -1, *saddr ? saddr
: NULL
,
5430 sport
, ssh
, &ssh
->cfg
);
5431 logeventf(ssh
, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5432 " doing SOCKS dynamic forwarding",
5433 (int)(*saddr?
strlen(saddr
):0), *saddr?saddr
:NULL
,
5434 (int)(*saddr?
1:0), ":",
5435 (int)(sserv ?
strlen(sports
) : 0), sports
,
5436 sserv
, "(", sport
, sserv
, ")");
5438 struct ssh_rportfwd
*pf
;
5439 pf
= snew(struct ssh_rportfwd
);
5440 strcpy(pf
->dhost
, host
);
5443 if (add234(ssh
->rportfwds
, pf
) != pf
) {
5444 logeventf(ssh
, "Duplicate remote port forwarding"
5445 " to %s:%d", host
, dport
);
5448 logeventf(ssh
, "Requesting remote port "
5449 "%.*s%.*s%.*s%.*s%d%.*s"
5450 " forward to %s:%.*s%.*s%d%.*s",
5451 (int)(*saddr?
strlen(saddr
):0),
5453 (int)(*saddr?
1:0), ":",
5454 (int)(sserv ?
strlen(sports
) : 0), sports
,
5455 sserv
, "(", sport
, sserv
, ")",
5457 (int)(dserv ?
strlen(dports
) : 0), dports
,
5458 dserv
, "(", dport
, dserv
, ")");
5459 ssh2_pkt_init(ssh
, SSH2_MSG_GLOBAL_REQUEST
);
5460 ssh2_pkt_addstring(ssh
, "tcpip-forward");
5461 ssh2_pkt_addbool(ssh
, 1);/* want reply */
5463 ssh2_pkt_addstring(ssh
, saddr
);
5464 if (ssh
->cfg
.rport_acceptall
)
5465 ssh2_pkt_addstring(ssh
, "0.0.0.0");
5467 ssh2_pkt_addstring(ssh
, "127.0.0.1");
5468 ssh2_pkt_adduint32(ssh
, sport
);
5472 crWaitUntilV(ispkt
);
5473 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5474 unsigned i
= ssh2_pkt_getuint32(ssh
);
5475 struct ssh_channel
*c
;
5476 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5478 continue;/* nonexistent channel */
5479 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5481 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5483 if (ssh
->pktin
.type
!= SSH2_MSG_REQUEST_SUCCESS
) {
5484 if (ssh
->pktin
.type
!= SSH2_MSG_REQUEST_FAILURE
) {
5485 bombout(("Unexpected response to port "
5486 "forwarding request: packet type %d",
5490 logevent("Server refused this port forwarding");
5492 logevent("Remote port forwarding enabled");
5501 * Potentially enable agent forwarding.
5503 if (ssh
->cfg
.agentfwd
&& agent_exists()) {
5504 logevent("Requesting OpenSSH-style agent forwarding");
5505 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5506 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
5507 ssh2_pkt_addstring(ssh
, "auth-agent-req@openssh.com");
5508 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5512 crWaitUntilV(ispkt
);
5513 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5514 unsigned i
= ssh2_pkt_getuint32(ssh
);
5515 struct ssh_channel
*c
;
5516 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5518 continue; /* nonexistent channel */
5519 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5521 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5523 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5524 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5525 bombout(("Unexpected response to agent forwarding request:"
5526 " packet type %d", ssh
->pktin
.type
));
5529 logevent("Agent forwarding refused");
5531 logevent("Agent forwarding enabled");
5532 ssh
->agentfwd_enabled
= TRUE
;
5537 * Now allocate a pty for the session.
5539 if (!ssh
->cfg
.nopty
) {
5540 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5541 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
); /* recipient channel */
5542 ssh2_pkt_addstring(ssh
, "pty-req");
5543 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5544 ssh2_pkt_addstring(ssh
, ssh
->cfg
.termtype
);
5545 ssh2_pkt_adduint32(ssh
, ssh
->term_width
);
5546 ssh2_pkt_adduint32(ssh
, ssh
->term_height
);
5547 ssh2_pkt_adduint32(ssh
, 0); /* pixel width */
5548 ssh2_pkt_adduint32(ssh
, 0); /* pixel height */
5549 ssh2_pkt_addstring_start(ssh
);
5550 ssh2_pkt_addstring_data(ssh
, "\0", 1); /* TTY_OP_END, no special options */
5552 ssh
->state
= SSH_STATE_INTERMED
;
5555 crWaitUntilV(ispkt
);
5556 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5557 unsigned i
= ssh2_pkt_getuint32(ssh
);
5558 struct ssh_channel
*c
;
5559 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5561 continue; /* nonexistent channel */
5562 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5564 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5566 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5567 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5568 bombout(("Unexpected response to pty request:"
5569 " packet type %d", ssh
->pktin
.type
));
5572 c_write_str(ssh
, "Server refused to allocate pty\r\n");
5573 ssh
->editing
= ssh
->echoing
= 1;
5575 logevent("Allocated pty");
5578 ssh
->editing
= ssh
->echoing
= 1;
5582 * Start a shell or a remote command. We may have to attempt
5583 * this twice if the config data has provided a second choice
5590 if (ssh
->fallback_cmd
) {
5591 subsys
= ssh
->cfg
.ssh_subsys2
;
5592 cmd
= ssh
->cfg
.remote_cmd_ptr2
;
5594 subsys
= ssh
->cfg
.ssh_subsys
;
5595 cmd
= ssh
->cfg
.remote_cmd_ptr
;
5598 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5599 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
); /* recipient channel */
5601 ssh2_pkt_addstring(ssh
, "subsystem");
5602 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5603 ssh2_pkt_addstring(ssh
, cmd
);
5605 ssh2_pkt_addstring(ssh
, "exec");
5606 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5607 ssh2_pkt_addstring(ssh
, cmd
);
5609 ssh2_pkt_addstring(ssh
, "shell");
5610 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5614 crWaitUntilV(ispkt
);
5615 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5616 unsigned i
= ssh2_pkt_getuint32(ssh
);
5617 struct ssh_channel
*c
;
5618 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5620 continue; /* nonexistent channel */
5621 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5623 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5624 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5625 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5626 bombout(("Unexpected response to shell/command request:"
5627 " packet type %d", ssh
->pktin
.type
));
5631 * We failed to start the command. If this is the
5632 * fallback command, we really are finished; if it's
5633 * not, and if the fallback command exists, try falling
5634 * back to it before complaining.
5636 if (!ssh
->fallback_cmd
&& ssh
->cfg
.remote_cmd_ptr2
!= NULL
) {
5637 logevent("Primary command failed; attempting fallback");
5638 ssh
->fallback_cmd
= TRUE
;
5641 bombout(("Server refused to start a shell/command"));
5644 logevent("Started a shell/command");
5649 ssh
->state
= SSH_STATE_SESSION
;
5650 if (ssh
->size_needed
)
5651 ssh_size(ssh
, ssh
->term_width
, ssh
->term_height
);
5652 if (ssh
->eof_needed
)
5653 ssh_special(ssh
, TS_EOF
);
5659 ldisc_send(ssh
->ldisc
, NULL
, 0, 0);/* cause ldisc to notice changes */
5663 s
->try_send
= FALSE
;
5665 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
5666 ssh
->pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
5669 unsigned i
= ssh2_pkt_getuint32(ssh
);
5670 struct ssh_channel
*c
;
5671 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5673 continue; /* nonexistent channel */
5674 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
5675 ssh2_pkt_getuint32(ssh
) != SSH2_EXTENDED_DATA_STDERR
)
5676 continue; /* extended but not stderr */
5677 ssh2_pkt_getstring(ssh
, &data
, &length
);
5680 c
->v
.v2
.locwindow
-= length
;
5682 case CHAN_MAINSESSION
:
5684 from_backend(ssh
->frontend
, ssh
->pktin
.type
==
5685 SSH2_MSG_CHANNEL_EXTENDED_DATA
,
5689 bufsize
= x11_send(c
->u
.x11
.s
, data
, length
);
5692 bufsize
= pfd_send(c
->u
.pfd
.s
, data
, length
);
5695 while (length
> 0) {
5696 if (c
->u
.a
.lensofar
< 4) {
5697 int l
= min(4 - c
->u
.a
.lensofar
, length
);
5698 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
,
5702 c
->u
.a
.lensofar
+= l
;
5704 if (c
->u
.a
.lensofar
== 4) {
5706 4 + GET_32BIT(c
->u
.a
.msglen
);
5707 c
->u
.a
.message
= snewn(c
->u
.a
.totallen
,
5709 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
5711 if (c
->u
.a
.lensofar
>= 4 && length
> 0) {
5713 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
5715 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
,
5719 c
->u
.a
.lensofar
+= l
;
5721 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
5724 if (agent_query(c
->u
.a
.message
,
5727 ssh_agentf_callback
, c
))
5728 ssh_agentf_callback(c
, reply
, replylen
);
5729 sfree(c
->u
.a
.message
);
5730 c
->u
.a
.lensofar
= 0;
5737 * If we are not buffering too much data,
5738 * enlarge the window again at the remote side.
5740 if (bufsize
< OUR_V2_WINSIZE
)
5741 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
5743 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_EOF
) {
5744 unsigned i
= ssh2_pkt_getuint32(ssh
);
5745 struct ssh_channel
*c
;
5747 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5749 continue; /* nonexistent channel */
5751 if (c
->type
== CHAN_X11
) {
5753 * Remote EOF on an X11 channel means we should
5754 * wrap up and close the channel ourselves.
5756 x11_close(c
->u
.x11
.s
);
5758 } else if (c
->type
== CHAN_AGENT
) {
5760 } else if (c
->type
== CHAN_SOCKDATA
) {
5761 pfd_close(c
->u
.pfd
.s
);
5764 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_CLOSE
) {
5765 unsigned i
= ssh2_pkt_getuint32(ssh
);
5766 struct ssh_channel
*c
;
5768 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5769 if (!c
|| ((int)c
->remoteid
) == -1) {
5770 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5771 c ?
"half-open" : "nonexistent", i
));
5774 /* Do pre-close processing on the channel. */
5776 case CHAN_MAINSESSION
:
5777 break; /* nothing to see here, move along */
5779 if (c
->u
.x11
.s
!= NULL
)
5780 x11_close(c
->u
.x11
.s
);
5787 if (c
->u
.pfd
.s
!= NULL
)
5788 pfd_close(c
->u
.pfd
.s
);
5792 if (c
->closes
== 0) {
5793 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_CLOSE
);
5794 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5797 del234(ssh
->channels
, c
);
5798 bufchain_clear(&c
->v
.v2
.outbuffer
);
5802 * See if that was the last channel left open.
5804 if (count234(ssh
->channels
) == 0) {
5805 logevent("All channels closed. Disconnecting");
5808 * We used to send SSH_MSG_DISCONNECT here,
5809 * because I'd believed that _every_ conforming
5810 * SSH2 connection had to end with a disconnect
5811 * being sent by at least one side; apparently
5812 * I was wrong and it's perfectly OK to
5813 * unceremoniously slam the connection shut
5814 * when you're done, and indeed OpenSSH feels
5815 * this is more polite than sending a
5816 * DISCONNECT. So now we don't.
5818 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
5819 ssh2_pkt_adduint32(ssh
, SSH2_DISCONNECT_BY_APPLICATION
);
5820 ssh2_pkt_addstring(ssh
, "All open channels closed");
5821 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5824 ssh_closing((Plug
)ssh
, NULL
, 0, 0);
5827 continue; /* remote sends close; ignore (FIXME) */
5828 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5829 unsigned i
= ssh2_pkt_getuint32(ssh
);
5830 struct ssh_channel
*c
;
5831 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5832 if (!c
|| c
->closes
)
5833 continue; /* nonexistent or closing channel */
5834 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5836 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
5837 unsigned i
= ssh2_pkt_getuint32(ssh
);
5838 struct ssh_channel
*c
;
5839 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5841 continue; /* nonexistent channel */
5842 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
5843 continue; /* dunno why they're confirming this */
5844 c
->remoteid
= ssh2_pkt_getuint32(ssh
);
5845 c
->type
= CHAN_SOCKDATA
;
5846 c
->v
.v2
.remwindow
= ssh2_pkt_getuint32(ssh
);
5847 c
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32(ssh
);
5849 pfd_confirm(c
->u
.pfd
.s
);
5852 * We have a pending close on this channel,
5853 * which we decided on before the server acked
5854 * the channel open. So now we know the
5855 * remoteid, we can close it again.
5857 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_CLOSE
);
5858 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5861 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_OPEN_FAILURE
) {
5862 unsigned i
= ssh2_pkt_getuint32(ssh
);
5863 struct ssh_channel
*c
;
5864 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5866 continue; /* nonexistent channel */
5867 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
5868 continue; /* dunno why they're failing this */
5870 logevent("Forwarded connection refused by server");
5872 pfd_close(c
->u
.pfd
.s
);
5874 del234(ssh
->channels
, c
);
5876 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_REQUEST
) {
5879 int typelen
, want_reply
;
5880 struct ssh_channel
*c
;
5882 localid
= ssh2_pkt_getuint32(ssh
);
5883 ssh2_pkt_getstring(ssh
, &type
, &typelen
);
5884 want_reply
= ssh2_pkt_getbool(ssh
);
5887 * First, check that the channel exists. Otherwise,
5888 * we can instantly disconnect with a rude message.
5890 c
= find234(ssh
->channels
, &localid
, ssh_channelfind
);
5893 sprintf(buf
, "Received channel request for nonexistent"
5894 " channel %d", localid
);
5896 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
5897 ssh2_pkt_adduint32(ssh
, SSH2_DISCONNECT_BY_APPLICATION
);
5898 ssh2_pkt_addstring(ssh
, buf
);
5899 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5901 connection_fatal(ssh
->frontend
, "%s", buf
);
5902 ssh_closing((Plug
)ssh
, NULL
, 0, 0);
5907 * Having got the channel number, we now look at
5908 * the request type string to see if it's something
5911 if (typelen
== 11 && !memcmp(type
, "exit-status", 11) &&
5912 c
== ssh
->mainchan
) {
5913 /* We recognise "exit-status" on the primary channel. */
5915 ssh
->exitcode
= ssh2_pkt_getuint32(ssh
);
5916 sprintf(buf
, "Server sent command exit status %d",
5920 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_SUCCESS
);
5921 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5926 * This is a channel request we don't know
5927 * about, so we now either ignore the request
5928 * or respond with CHANNEL_FAILURE, depending
5932 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_FAILURE
);
5933 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5937 } else if (ssh
->pktin
.type
== SSH2_MSG_GLOBAL_REQUEST
) {
5939 int typelen
, want_reply
;
5941 ssh2_pkt_getstring(ssh
, &type
, &typelen
);
5942 want_reply
= ssh2_pkt_getbool(ssh
);
5945 * We currently don't support any global requests
5946 * at all, so we either ignore the request or
5947 * respond with REQUEST_FAILURE, depending on
5951 ssh2_pkt_init(ssh
, SSH2_MSG_REQUEST_FAILURE
);
5954 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_OPEN
) {
5961 struct ssh_channel
*c
;
5962 unsigned remid
, winsize
, pktsize
;
5963 ssh2_pkt_getstring(ssh
, &type
, &typelen
);
5964 c
= snew(struct ssh_channel
);
5967 remid
= ssh2_pkt_getuint32(ssh
);
5968 winsize
= ssh2_pkt_getuint32(ssh
);
5969 pktsize
= ssh2_pkt_getuint32(ssh
);
5971 if (typelen
== 3 && !memcmp(type
, "x11", 3)) {
5974 ssh2_pkt_getstring(ssh
, &peeraddr
, &peeraddrlen
);
5975 addrstr
= snewn(peeraddrlen
+1, char);
5976 memcpy(addrstr
, peeraddr
, peeraddrlen
);
5977 peeraddr
[peeraddrlen
] = '\0';
5978 peerport
= ssh2_pkt_getuint32(ssh
);
5980 if (!ssh
->X11_fwd_enabled
)
5981 error
= "X11 forwarding is not enabled";
5982 else if (x11_init(&c
->u
.x11
.s
, ssh
->cfg
.x11_display
, c
,
5983 ssh
->x11auth
, addrstr
, peerport
,
5984 &ssh
->cfg
) != NULL
) {
5985 error
= "Unable to open an X11 connection";
5991 } else if (typelen
== 15 &&
5992 !memcmp(type
, "forwarded-tcpip", 15)) {
5993 struct ssh_rportfwd pf
, *realpf
;
5996 ssh2_pkt_getstring(ssh
, &dummy
, &dummylen
);/* skip address */
5997 pf
.sport
= ssh2_pkt_getuint32(ssh
);
5998 ssh2_pkt_getstring(ssh
, &peeraddr
, &peeraddrlen
);
5999 peerport
= ssh2_pkt_getuint32(ssh
);
6000 realpf
= find234(ssh
->rportfwds
, &pf
, NULL
);
6001 if (realpf
== NULL
) {
6002 error
= "Remote port is not recognised";
6004 const char *e
= pfd_newconnect(&c
->u
.pfd
.s
,
6008 logeventf(ssh
, "Received remote port open request"
6009 " for %s:%d", realpf
->dhost
, realpf
->dport
);
6011 logeventf(ssh
, "Port open failed: %s", e
);
6012 error
= "Port open failed";
6014 logevent("Forwarded port opened successfully");
6015 c
->type
= CHAN_SOCKDATA
;
6018 } else if (typelen
== 22 &&
6019 !memcmp(type
, "auth-agent@openssh.com", 3)) {
6020 if (!ssh
->agentfwd_enabled
)
6021 error
= "Agent forwarding is not enabled";
6023 c
->type
= CHAN_AGENT
; /* identify channel type */
6024 c
->u
.a
.lensofar
= 0;
6027 error
= "Unsupported channel type requested";
6030 c
->remoteid
= remid
;
6032 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN_FAILURE
);
6033 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
6034 ssh2_pkt_adduint32(ssh
, SSH2_OPEN_CONNECT_FAILED
);
6035 ssh2_pkt_addstring(ssh
, error
);
6036 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
6040 c
->localid
= alloc_channel_id(ssh
);
6042 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
6043 c
->v
.v2
.remwindow
= winsize
;
6044 c
->v
.v2
.remmaxpkt
= pktsize
;
6045 bufchain_init(&c
->v
.v2
.outbuffer
);
6046 add234(ssh
->channels
, c
);
6047 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
6048 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
6049 ssh2_pkt_adduint32(ssh
, c
->localid
);
6050 ssh2_pkt_adduint32(ssh
, c
->v
.v2
.locwindow
);
6051 ssh2_pkt_adduint32(ssh
, 0x4000UL
); /* our max pkt size */
6055 bombout(("Strange packet received: type %d", ssh
->pktin
.type
));
6060 * We have spare data. Add it to the channel buffer.
6062 ssh2_add_channel_data(ssh
->mainchan
, (char *)in
, inlen
);
6067 struct ssh_channel
*c
;
6069 * Try to send data on all channels if we can.
6071 for (i
= 0; NULL
!= (c
= index234(ssh
->channels
, i
)); i
++) {
6074 continue; /* don't send on closing channels */
6075 bufsize
= ssh2_try_send(c
);
6078 case CHAN_MAINSESSION
:
6079 /* stdin need not receive an unthrottle
6080 * notification since it will be polled */
6083 x11_unthrottle(c
->u
.x11
.s
);
6086 /* agent sockets are request/response and need no
6087 * buffer management */
6090 pfd_unthrottle(c
->u
.pfd
.s
);
6102 * Handle the top-level SSH2 protocol.
6104 static void ssh2_protocol(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
6106 if (do_ssh2_transport(ssh
, in
, inlen
, ispkt
) == 0)
6108 do_ssh2_authconn(ssh
, in
, inlen
, ispkt
);
6112 * Called to set up the connection.
6114 * Returns an error message, or NULL on success.
6116 static const char *ssh_init(void *frontend_handle
, void **backend_handle
,
6118 char *host
, int port
, char **realhost
, int nodelay
)
6123 ssh
= snew(struct ssh_tag
);
6124 ssh
->cfg
= *cfg
; /* STRUCTURE COPY */
6125 ssh
->version
= 0; /* when not ready yet */
6128 ssh
->v1_cipher_ctx
= NULL
;
6129 ssh
->crcda_ctx
= NULL
;
6130 ssh
->cscipher
= NULL
;
6131 ssh
->cs_cipher_ctx
= NULL
;
6132 ssh
->sccipher
= NULL
;
6133 ssh
->sc_cipher_ctx
= NULL
;
6135 ssh
->cs_mac_ctx
= NULL
;
6137 ssh
->sc_mac_ctx
= NULL
;
6139 ssh
->cs_comp_ctx
= NULL
;
6141 ssh
->sc_comp_ctx
= NULL
;
6143 ssh
->kex_ctx
= NULL
;
6144 ssh
->hostkey
= NULL
;
6146 ssh
->state
= SSH_STATE_PREPACKET
;
6147 ssh
->size_needed
= FALSE
;
6148 ssh
->eof_needed
= FALSE
;
6152 static const struct Packet empty
= { 0, 0, NULL
, NULL
, 0 };
6153 ssh
->pktin
= ssh
->pktout
= empty
;
6155 ssh
->deferred_send_data
= NULL
;
6156 ssh
->deferred_len
= 0;
6157 ssh
->deferred_size
= 0;
6158 ssh
->fallback_cmd
= 0;
6160 ssh
->x11auth
= NULL
;
6161 ssh
->v1_compressing
= FALSE
;
6162 ssh
->v2_outgoing_sequence
= 0;
6163 ssh
->ssh1_rdpkt_crstate
= 0;
6164 ssh
->ssh2_rdpkt_crstate
= 0;
6165 ssh
->do_ssh_init_crstate
= 0;
6166 ssh
->ssh_gotdata_crstate
= 0;
6167 ssh
->ssh1_protocol_crstate
= 0;
6168 ssh
->do_ssh1_login_crstate
= 0;
6169 ssh
->do_ssh2_transport_crstate
= 0;
6170 ssh
->do_ssh2_authconn_crstate
= 0;
6171 ssh
->do_ssh_init_state
= NULL
;
6172 ssh
->do_ssh1_login_state
= NULL
;
6173 ssh
->do_ssh2_transport_state
= NULL
;
6174 ssh
->do_ssh2_authconn_state
= NULL
;
6175 ssh
->mainchan
= NULL
;
6176 ssh
->throttled_all
= 0;
6177 ssh
->v1_stdout_throttling
= 0;
6179 *backend_handle
= ssh
;
6182 if (crypto_startup() == 0)
6183 return "Microsoft high encryption pack not installed!";
6186 ssh
->frontend
= frontend_handle
;
6187 ssh
->term_width
= ssh
->cfg
.width
;
6188 ssh
->term_height
= ssh
->cfg
.height
;
6190 ssh
->channels
= NULL
;
6191 ssh
->rportfwds
= NULL
;
6196 ssh
->v1_throttle_count
= 0;
6197 ssh
->overall_bufsize
= 0;
6198 ssh
->fallback_cmd
= 0;
6200 ssh
->protocol
= NULL
;
6202 p
= connect_to_host(ssh
, host
, port
, realhost
, nodelay
);
6209 static void ssh_free(void *handle
)
6211 Ssh ssh
= (Ssh
) handle
;
6212 struct ssh_channel
*c
;
6213 struct ssh_rportfwd
*pf
;
6215 if (ssh
->v1_cipher_ctx
)
6216 ssh
->cipher
->free_context(ssh
->v1_cipher_ctx
);
6217 if (ssh
->cs_cipher_ctx
)
6218 ssh
->cscipher
->free_context(ssh
->cs_cipher_ctx
);
6219 if (ssh
->sc_cipher_ctx
)
6220 ssh
->sccipher
->free_context(ssh
->sc_cipher_ctx
);
6221 if (ssh
->cs_mac_ctx
)
6222 ssh
->csmac
->free_context(ssh
->cs_mac_ctx
);
6223 if (ssh
->sc_mac_ctx
)
6224 ssh
->scmac
->free_context(ssh
->sc_mac_ctx
);
6225 if (ssh
->cs_comp_ctx
)
6226 ssh
->cscomp
->compress_cleanup(ssh
->cs_comp_ctx
);
6227 if (ssh
->sc_comp_ctx
)
6228 ssh
->sccomp
->compress_cleanup(ssh
->sc_comp_ctx
);
6230 dh_cleanup(ssh
->kex_ctx
);
6231 sfree(ssh
->savedhost
);
6233 if (ssh
->channels
) {
6234 while ((c
= delpos234(ssh
->channels
, 0)) != NULL
) {
6237 if (c
->u
.x11
.s
!= NULL
)
6238 x11_close(c
->u
.x11
.s
);
6241 if (c
->u
.pfd
.s
!= NULL
)
6242 pfd_close(c
->u
.pfd
.s
);
6247 freetree234(ssh
->channels
);
6250 if (ssh
->rportfwds
) {
6251 while ((pf
= delpos234(ssh
->rportfwds
, 0)) != NULL
)
6253 freetree234(ssh
->rportfwds
);
6255 sfree(ssh
->deferred_send_data
);
6257 x11_free_auth(ssh
->x11auth
);
6258 sfree(ssh
->do_ssh_init_state
);
6259 sfree(ssh
->do_ssh1_login_state
);
6260 sfree(ssh
->do_ssh2_transport_state
);
6261 sfree(ssh
->do_ssh2_authconn_state
);
6269 * Reconfigure the SSH backend.
6271 * Currently, this function does nothing very useful. In future,
6272 * however, we could do some handy things with it. For example, we
6273 * could make the port forwarding configurer active in the Change
6274 * Settings box, and this routine could close down existing
6275 * forwardings and open up new ones in response to changes.
6277 static void ssh_reconfig(void *handle
, Config
*cfg
)
6279 Ssh ssh
= (Ssh
) handle
;
6280 ssh
->cfg
= *cfg
; /* STRUCTURE COPY */
6284 * Called to send data down the Telnet connection.
6286 static int ssh_send(void *handle
, char *buf
, int len
)
6288 Ssh ssh
= (Ssh
) handle
;
6290 if (ssh
== NULL
|| ssh
->s
== NULL
|| ssh
->protocol
== NULL
)
6293 ssh
->protocol(ssh
, (unsigned char *)buf
, len
, 0);
6295 return ssh_sendbuffer(ssh
);
6299 * Called to query the current amount of buffered stdin data.
6301 static int ssh_sendbuffer(void *handle
)
6303 Ssh ssh
= (Ssh
) handle
;
6306 if (ssh
== NULL
|| ssh
->s
== NULL
|| ssh
->protocol
== NULL
)
6310 * If the SSH socket itself has backed up, add the total backup
6311 * size on that to any individual buffer on the stdin channel.
6314 if (ssh
->throttled_all
)
6315 override_value
= ssh
->overall_bufsize
;
6317 if (ssh
->version
== 1) {
6318 return override_value
;
6319 } else if (ssh
->version
== 2) {
6320 if (!ssh
->mainchan
|| ssh
->mainchan
->closes
> 0)
6321 return override_value
;
6323 return (override_value
+
6324 bufchain_size(&ssh
->mainchan
->v
.v2
.outbuffer
));
6331 * Called to set the size of the window from SSH's POV.
6333 static void ssh_size(void *handle
, int width
, int height
)
6335 Ssh ssh
= (Ssh
) handle
;
6337 ssh
->term_width
= width
;
6338 ssh
->term_height
= height
;
6340 switch (ssh
->state
) {
6341 case SSH_STATE_BEFORE_SIZE
:
6342 case SSH_STATE_PREPACKET
:
6343 case SSH_STATE_CLOSED
:
6344 break; /* do nothing */
6345 case SSH_STATE_INTERMED
:
6346 ssh
->size_needed
= TRUE
; /* buffer for later */
6348 case SSH_STATE_SESSION
:
6349 if (!ssh
->cfg
.nopty
) {
6350 if (ssh
->version
== 1) {
6351 send_packet(ssh
, SSH1_CMSG_WINDOW_SIZE
,
6352 PKT_INT
, ssh
->term_height
,
6353 PKT_INT
, ssh
->term_width
,
6354 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
6356 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
6357 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
6358 ssh2_pkt_addstring(ssh
, "window-change");
6359 ssh2_pkt_addbool(ssh
, 0);
6360 ssh2_pkt_adduint32(ssh
, ssh
->term_width
);
6361 ssh2_pkt_adduint32(ssh
, ssh
->term_height
);
6362 ssh2_pkt_adduint32(ssh
, 0);
6363 ssh2_pkt_adduint32(ssh
, 0);
6372 * Return a list of the special codes that make sense in this
6375 static const struct telnet_special
*ssh_get_specials(void *handle
)
6377 Ssh ssh
= (Ssh
) handle
;
6379 if (ssh
->version
== 1) {
6380 static const struct telnet_special ssh1_specials
[] = {
6381 {"IGNORE message", TS_NOP
},
6384 return ssh1_specials
;
6385 } else if (ssh
->version
== 2) {
6386 static const struct telnet_special ssh2_specials
[] = {
6388 {"IGNORE message", TS_NOP
},
6391 return ssh2_specials
;
6397 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6398 * can send an EOF and collect resulting output (e.g. `plink
6401 static void ssh_special(void *handle
, Telnet_Special code
)
6403 Ssh ssh
= (Ssh
) handle
;
6405 if (code
== TS_EOF
) {
6406 if (ssh
->state
!= SSH_STATE_SESSION
) {
6408 * Buffer the EOF in case we are pre-SESSION, so we can
6409 * send it as soon as we reach SESSION.
6412 ssh
->eof_needed
= TRUE
;
6415 if (ssh
->version
== 1) {
6416 send_packet(ssh
, SSH1_CMSG_EOF
, PKT_END
);
6418 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_EOF
);
6419 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
6422 logevent("Sent EOF message");
6423 } else if (code
== TS_PING
|| code
== TS_NOP
) {
6424 if (ssh
->state
== SSH_STATE_CLOSED
6425 || ssh
->state
== SSH_STATE_PREPACKET
) return;
6426 if (ssh
->version
== 1) {
6427 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
))
6428 send_packet(ssh
, SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
6430 ssh2_pkt_init(ssh
, SSH2_MSG_IGNORE
);
6431 ssh2_pkt_addstring_start(ssh
);
6434 } else if (code
== TS_BRK
) {
6435 if (ssh
->state
== SSH_STATE_CLOSED
6436 || ssh
->state
== SSH_STATE_PREPACKET
) return;
6437 if (ssh
->version
== 1) {
6438 logevent("Unable to send BREAK signal in SSH1");
6440 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
6441 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
6442 ssh2_pkt_addstring(ssh
, "break");
6443 ssh2_pkt_addbool(ssh
, 0);
6444 ssh2_pkt_adduint32(ssh
, 0); /* default break length */
6452 void *new_sock_channel(void *handle
, Socket s
)
6454 Ssh ssh
= (Ssh
) handle
;
6455 struct ssh_channel
*c
;
6456 c
= snew(struct ssh_channel
);
6460 c
->remoteid
= -1; /* to be set when open confirmed */
6461 c
->localid
= alloc_channel_id(ssh
);
6463 c
->type
= CHAN_SOCKDATA_DORMANT
;/* identify channel type */
6465 bufchain_init(&c
->v
.v2
.outbuffer
);
6466 add234(ssh
->channels
, c
);
6472 * This is called when stdout/stderr (the entity to which
6473 * from_backend sends data) manages to clear some backlog.
6475 static void ssh_unthrottle(void *handle
, int bufsize
)
6477 Ssh ssh
= (Ssh
) handle
;
6478 if (ssh
->version
== 1) {
6479 if (ssh
->v1_stdout_throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
6480 ssh
->v1_stdout_throttling
= 0;
6481 ssh1_throttle(ssh
, -1);
6484 if (ssh
->mainchan
&& ssh
->mainchan
->closes
== 0)
6485 ssh2_set_window(ssh
->mainchan
, OUR_V2_WINSIZE
- bufsize
);
6489 void ssh_send_port_open(void *channel
, char *hostname
, int port
, char *org
)
6491 struct ssh_channel
*c
= (struct ssh_channel
*)channel
;
6494 logeventf(ssh
, "Opening forwarded connection to %s:%d", hostname
, port
);
6496 if (ssh
->version
== 1) {
6497 send_packet(ssh
, SSH1_MSG_PORT_OPEN
,
6498 PKT_INT
, c
->localid
,
6501 //PKT_STR, <org:orgport>,
6504 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN
);
6505 ssh2_pkt_addstring(ssh
, "direct-tcpip");
6506 ssh2_pkt_adduint32(ssh
, c
->localid
);
6507 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
6508 ssh2_pkt_adduint32(ssh
, c
->v
.v2
.locwindow
);/* our window size */
6509 ssh2_pkt_adduint32(ssh
, 0x4000UL
); /* our max pkt size */
6510 ssh2_pkt_addstring(ssh
, hostname
);
6511 ssh2_pkt_adduint32(ssh
, port
);
6513 * We make up values for the originator data; partly it's
6514 * too much hassle to keep track, and partly I'm not
6515 * convinced the server should be told details like that
6516 * about my local network configuration.
6518 ssh2_pkt_addstring(ssh
, "client-side-connection");
6519 ssh2_pkt_adduint32(ssh
, 0);
6525 static Socket
ssh_socket(void *handle
)
6527 Ssh ssh
= (Ssh
) handle
;
6531 static int ssh_sendok(void *handle
)
6533 Ssh ssh
= (Ssh
) handle
;
6534 return ssh
->send_ok
;
6537 static int ssh_ldisc(void *handle
, int option
)
6539 Ssh ssh
= (Ssh
) handle
;
6540 if (option
== LD_ECHO
)
6541 return ssh
->echoing
;
6542 if (option
== LD_EDIT
)
6543 return ssh
->editing
;
6547 static void ssh_provide_ldisc(void *handle
, void *ldisc
)
6549 Ssh ssh
= (Ssh
) handle
;
6553 static void ssh_provide_logctx(void *handle
, void *logctx
)
6555 Ssh ssh
= (Ssh
) handle
;
6556 ssh
->logctx
= logctx
;
6559 static int ssh_return_exitcode(void *handle
)
6561 Ssh ssh
= (Ssh
) handle
;
6565 return (ssh
->exitcode
>= 0 ? ssh
->exitcode
: 0);
6569 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6570 * that fails. This variable is the means by which scp.c can reach
6571 * into the SSH code and find out which one it got.
6573 extern int ssh_fallback_cmd(void *handle
)
6575 Ssh ssh
= (Ssh
) handle
;
6576 return ssh
->fallback_cmd
;
6579 Backend ssh_backend
= {
6589 ssh_return_exitcode
,