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
167 #define translate(x) if (type == x) return #x
168 #define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
169 char *ssh1_pkt_type(int type
)
171 translate(SSH1_MSG_DISCONNECT
);
172 translate(SSH1_SMSG_PUBLIC_KEY
);
173 translate(SSH1_CMSG_SESSION_KEY
);
174 translate(SSH1_CMSG_USER
);
175 translate(SSH1_CMSG_AUTH_RSA
);
176 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE
);
177 translate(SSH1_CMSG_AUTH_RSA_RESPONSE
);
178 translate(SSH1_CMSG_AUTH_PASSWORD
);
179 translate(SSH1_CMSG_REQUEST_PTY
);
180 translate(SSH1_CMSG_WINDOW_SIZE
);
181 translate(SSH1_CMSG_EXEC_SHELL
);
182 translate(SSH1_CMSG_EXEC_CMD
);
183 translate(SSH1_SMSG_SUCCESS
);
184 translate(SSH1_SMSG_FAILURE
);
185 translate(SSH1_CMSG_STDIN_DATA
);
186 translate(SSH1_SMSG_STDOUT_DATA
);
187 translate(SSH1_SMSG_STDERR_DATA
);
188 translate(SSH1_CMSG_EOF
);
189 translate(SSH1_SMSG_EXIT_STATUS
);
190 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
);
191 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE
);
192 translate(SSH1_MSG_CHANNEL_DATA
);
193 translate(SSH1_MSG_CHANNEL_CLOSE
);
194 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
);
195 translate(SSH1_SMSG_X11_OPEN
);
196 translate(SSH1_CMSG_PORT_FORWARD_REQUEST
);
197 translate(SSH1_MSG_PORT_OPEN
);
198 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING
);
199 translate(SSH1_SMSG_AGENT_OPEN
);
200 translate(SSH1_MSG_IGNORE
);
201 translate(SSH1_CMSG_EXIT_CONFIRMATION
);
202 translate(SSH1_CMSG_X11_REQUEST_FORWARDING
);
203 translate(SSH1_CMSG_AUTH_RHOSTS_RSA
);
204 translate(SSH1_MSG_DEBUG
);
205 translate(SSH1_CMSG_REQUEST_COMPRESSION
);
206 translate(SSH1_CMSG_AUTH_TIS
);
207 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE
);
208 translate(SSH1_CMSG_AUTH_TIS_RESPONSE
);
209 translate(SSH1_CMSG_AUTH_CCARD
);
210 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE
);
211 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE
);
214 char *ssh2_pkt_type(int pkt_ctx
, int type
)
216 translate(SSH2_MSG_DISCONNECT
);
217 translate(SSH2_MSG_IGNORE
);
218 translate(SSH2_MSG_UNIMPLEMENTED
);
219 translate(SSH2_MSG_DEBUG
);
220 translate(SSH2_MSG_SERVICE_REQUEST
);
221 translate(SSH2_MSG_SERVICE_ACCEPT
);
222 translate(SSH2_MSG_KEXINIT
);
223 translate(SSH2_MSG_NEWKEYS
);
224 translatec(SSH2_MSG_KEXDH_INIT
, SSH2_PKTCTX_DHGROUP1
);
225 translatec(SSH2_MSG_KEXDH_REPLY
, SSH2_PKTCTX_DHGROUP1
);
226 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST
, SSH2_PKTCTX_DHGEX
);
227 translatec(SSH2_MSG_KEX_DH_GEX_GROUP
, SSH2_PKTCTX_DHGEX
);
228 translatec(SSH2_MSG_KEX_DH_GEX_INIT
, SSH2_PKTCTX_DHGEX
);
229 translatec(SSH2_MSG_KEX_DH_GEX_REPLY
, SSH2_PKTCTX_DHGEX
);
230 translate(SSH2_MSG_USERAUTH_REQUEST
);
231 translate(SSH2_MSG_USERAUTH_FAILURE
);
232 translate(SSH2_MSG_USERAUTH_SUCCESS
);
233 translate(SSH2_MSG_USERAUTH_BANNER
);
234 translatec(SSH2_MSG_USERAUTH_PK_OK
, SSH2_PKTCTX_PUBLICKEY
);
235 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ
, SSH2_PKTCTX_PASSWORD
);
236 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST
, SSH2_PKTCTX_KBDINTER
);
237 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE
, SSH2_PKTCTX_KBDINTER
);
238 translate(SSH2_MSG_GLOBAL_REQUEST
);
239 translate(SSH2_MSG_REQUEST_SUCCESS
);
240 translate(SSH2_MSG_REQUEST_FAILURE
);
241 translate(SSH2_MSG_CHANNEL_OPEN
);
242 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
243 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE
);
244 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
245 translate(SSH2_MSG_CHANNEL_DATA
);
246 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA
);
247 translate(SSH2_MSG_CHANNEL_EOF
);
248 translate(SSH2_MSG_CHANNEL_CLOSE
);
249 translate(SSH2_MSG_CHANNEL_REQUEST
);
250 translate(SSH2_MSG_CHANNEL_SUCCESS
);
251 translate(SSH2_MSG_CHANNEL_FAILURE
);
257 #define GET_32BIT(cp) \
258 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
259 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
260 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
261 ((unsigned long)(unsigned char)(cp)[3]))
263 #define PUT_32BIT(cp, value) { \
264 (cp)[0] = (unsigned char)((value) >> 24); \
265 (cp)[1] = (unsigned char)((value) >> 16); \
266 (cp)[2] = (unsigned char)((value) >> 8); \
267 (cp)[3] = (unsigned char)(value); }
269 enum { PKT_END
, PKT_INT
, PKT_CHAR
, PKT_DATA
, PKT_STR
, PKT_BIGNUM
};
271 /* Coroutine mechanics for the sillier bits of the code */
272 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
275 if (!ssh->t) ssh->t = smalloc(sizeof(struct t)); \
277 #define crFinish(z) } *crLine = 0; return (z); }
278 #define crFinishV } *crLine = 0; return; }
279 #define crReturn(z) \
281 *crLine =__LINE__; return (z); case __LINE__:;\
285 *crLine=__LINE__; return; case __LINE__:;\
287 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
288 #define crStopV do{ *crLine = 0; return; }while(0)
289 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
290 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
292 typedef struct ssh_tag
*Ssh
;
294 extern char *x11_init(Socket
*, char *, void *, void *);
295 extern void x11_close(Socket
);
296 extern int x11_send(Socket
, char *, int);
297 extern void *x11_invent_auth(char *, int, char *, int);
298 extern void x11_unthrottle(Socket s
);
299 extern void x11_override_throttle(Socket s
, int enable
);
301 extern char *pfd_newconnect(Socket
* s
, char *hostname
, int port
, void *c
);
302 extern char *pfd_addforward(char *desthost
, int destport
, char *srcaddr
,
303 int port
, void *backhandle
);
304 extern void pfd_close(Socket s
);
305 extern int pfd_send(Socket s
, char *data
, int len
);
306 extern void pfd_confirm(Socket s
);
307 extern void pfd_unthrottle(Socket s
);
308 extern void pfd_override_throttle(Socket s
, int enable
);
310 static void ssh2_pkt_init(Ssh
, int pkt_type
);
311 static void ssh2_pkt_addbool(Ssh
, unsigned char value
);
312 static void ssh2_pkt_adduint32(Ssh
, unsigned long value
);
313 static void ssh2_pkt_addstring_start(Ssh
);
314 static void ssh2_pkt_addstring_str(Ssh
, char *data
);
315 static void ssh2_pkt_addstring_data(Ssh
, char *data
, int len
);
316 static void ssh2_pkt_addstring(Ssh
, char *data
);
317 static char *ssh2_mpint_fmt(Bignum b
, int *len
);
318 static void ssh2_pkt_addmp(Ssh
, Bignum b
);
319 static int ssh2_pkt_construct(Ssh
);
320 static void ssh2_pkt_send(Ssh
);
323 * Buffer management constants. There are several of these for
324 * various different purposes:
326 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
327 * on a local data stream before we throttle the whole SSH
328 * connection (in SSH1 only). Throttling the whole connection is
329 * pretty drastic so we set this high in the hope it won't
332 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
333 * on the SSH connection itself before we defensively throttle
334 * _all_ local data streams. This is pretty drastic too (though
335 * thankfully unlikely in SSH2 since the window mechanism should
336 * ensure that the server never has any need to throttle its end
337 * of the connection), so we set this high as well.
339 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
343 #define SSH1_BUFFER_LIMIT 32768
344 #define SSH_MAX_BACKLOG 32768
345 #define OUR_V2_WINSIZE 16384
347 const static struct ssh_kex
*kex_algs
[] = {
348 &ssh_diffiehellman_gex
,
352 const static struct ssh_signkey
*hostkey_algs
[] = { &ssh_rsa
, &ssh_dss
};
354 static void *nullmac_make_context(void)
358 static void nullmac_free_context(void *handle
)
361 static void nullmac_key(void *handle
, unsigned char *key
)
364 static void nullmac_generate(void *handle
, unsigned char *blk
, int len
,
368 static int nullmac_verify(void *handle
, unsigned char *blk
, int len
,
373 const static struct ssh_mac ssh_mac_none
= {
374 nullmac_make_context
, nullmac_free_context
, nullmac_key
,
375 nullmac_generate
, nullmac_verify
, "none", 0
377 const static struct ssh_mac
*macs
[] = {
378 &ssh_sha1
, &ssh_md5
, &ssh_mac_none
380 const static struct ssh_mac
*buggymacs
[] = {
381 &ssh_sha1_buggy
, &ssh_md5
, &ssh_mac_none
384 static void *ssh_comp_none_init(void)
388 static void ssh_comp_none_cleanup(void *handle
)
391 static int ssh_comp_none_block(void *handle
, unsigned char *block
, int len
,
392 unsigned char **outblock
, int *outlen
)
396 static int ssh_comp_none_disable(void *handle
)
400 const static struct ssh_compress ssh_comp_none
= {
402 ssh_comp_none_init
, ssh_comp_none_cleanup
, ssh_comp_none_block
,
403 ssh_comp_none_init
, ssh_comp_none_cleanup
, ssh_comp_none_block
,
404 ssh_comp_none_disable
, NULL
406 extern const struct ssh_compress ssh_zlib
;
407 const static struct ssh_compress
*compressions
[] = {
408 &ssh_zlib
, &ssh_comp_none
411 enum { /* channel types */
416 CHAN_SOCKDATA_DORMANT
/* one the remote hasn't confirmed */
420 * 2-3-4 tree storing channels.
423 Ssh ssh
; /* pointer back to main context */
424 unsigned remoteid
, localid
;
427 * In SSH1, this value contains four bits:
429 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
430 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
431 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
432 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
434 * A channel is completely finished with when all four bits are set.
438 struct ssh1_data_channel
{
441 struct ssh2_data_channel
{
443 unsigned remwindow
, remmaxpkt
;
448 struct ssh_agent_channel
{
449 unsigned char *message
;
450 unsigned char msglen
[4];
451 int lensofar
, totallen
;
453 struct ssh_x11_channel
{
456 struct ssh_pfd_channel
{
463 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
464 * 2 use this structure in different ways, reflecting SSH 2's
465 * altogether saner approach to port forwarding.
467 * In SSH 1, you arrange a remote forwarding by sending the server
468 * the remote port number, and the local destination host:port.
469 * When a connection comes in, the server sends you back that
470 * host:port pair, and you connect to it. This is a ready-made
471 * security hole if you're not on the ball: a malicious server
472 * could send you back _any_ host:port pair, so if you trustingly
473 * connect to the address it gives you then you've just opened the
474 * entire inside of your corporate network just by connecting
475 * through it to a dodgy SSH server. Hence, we must store a list of
476 * host:port pairs we _are_ trying to forward to, and reject a
477 * connection request from the server if it's not in the list.
479 * In SSH 2, each side of the connection minds its own business and
480 * doesn't send unnecessary information to the other. You arrange a
481 * remote forwarding by sending the server just the remote port
482 * number. When a connection comes in, the server tells you which
483 * of its ports was connected to; and _you_ have to remember what
484 * local host:port pair went with that port number.
486 * Hence: in SSH 1 this structure stores host:port pairs we intend
487 * to allow connections to, and is indexed by those host:port
488 * pairs. In SSH 2 it stores a mapping from source port to
489 * destination host:port pair, and is indexed by source port.
491 struct ssh_rportfwd
{
492 unsigned sport
, dport
;
505 static void ssh1_protocol(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
);
506 static void ssh2_protocol(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
);
507 static void ssh_size(void *handle
, int width
, int height
);
508 static void ssh_special(void *handle
, Telnet_Special
);
509 static int ssh2_try_send(struct ssh_channel
*c
);
510 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
, int len
);
511 static void ssh_throttle_all(Ssh ssh
, int enable
, int bufsize
);
512 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
);
513 static int ssh_sendbuffer(void *handle
);
515 struct rdpkt1_state_tag
{
516 long len
, pad
, biglen
, to_read
;
517 unsigned long realcrc
, gotcrc
;
523 struct rdpkt2_state_tag
{
524 long len
, pad
, payload
, packetlen
, maclen
;
527 unsigned long incoming_sequence
;
531 const struct plug_function_table
*fn
;
532 /* the above field _must_ be first in the structure */
534 SHA_State exhash
, exhashbase
;
541 unsigned char session_key
[32];
543 int v1_remote_protoflags
;
544 int v1_local_protoflags
;
545 int agentfwd_enabled
;
548 const struct ssh_cipher
*cipher
;
551 const struct ssh2_cipher
*cscipher
, *sccipher
;
552 void *cs_cipher_ctx
, *sc_cipher_ctx
;
553 const struct ssh_mac
*csmac
, *scmac
;
554 void *cs_mac_ctx
, *sc_mac_ctx
;
555 const struct ssh_compress
*cscomp
, *sccomp
;
556 void *cs_comp_ctx
, *sc_comp_ctx
;
557 const struct ssh_kex
*kex
;
558 const struct ssh_signkey
*hostkey
;
559 unsigned char v2_session_id
[20];
565 int echoing
, editing
;
569 int term_width
, term_height
;
571 tree234
*channels
; /* indexed by local id */
572 struct ssh_channel
*mainchan
; /* primary session channel */
579 SSH_STATE_BEFORE_SIZE
,
585 int size_needed
, eof_needed
;
588 struct Packet pktout
;
589 unsigned char *deferred_send_data
;
590 int deferred_len
, deferred_size
;
593 * Gross hack: pscp will try to start SFTP but fall back to
594 * scp1 if that fails. This variable is the means by which
595 * scp.c can reach into the SSH code and find out which one it
601 * Used for username and password input.
603 char *userpass_input_buffer
;
604 int userpass_input_buflen
;
605 int userpass_input_bufpos
;
606 int userpass_input_echo
;
608 char *portfwd_strptr
;
614 int v1_throttle_count
;
617 int v1_stdout_throttling
;
618 int v2_outgoing_sequence
;
620 int ssh1_rdpkt_crstate
;
621 int ssh2_rdpkt_crstate
;
622 int do_ssh_init_crstate
;
623 int ssh_gotdata_crstate
;
624 int ssh1_protocol_crstate
;
625 int do_ssh1_login_crstate
;
626 int do_ssh2_transport_crstate
;
627 int do_ssh2_authconn_crstate
;
629 void *do_ssh_init_state
;
630 void *do_ssh1_login_state
;
631 void *do_ssh2_transport_state
;
632 void *do_ssh2_authconn_state
;
634 struct rdpkt1_state_tag rdpkt1_state
;
635 struct rdpkt2_state_tag rdpkt2_state
;
637 void (*protocol
) (Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
);
638 int (*s_rdpkt
) (Ssh ssh
, unsigned char **data
, int *datalen
);
641 #define logevent(s) logevent(ssh->frontend, s)
643 /* logevent, only printf-formatted. */
644 void logeventf(Ssh ssh
, char *fmt
, ...)
650 buf
= dupvprintf(fmt
, ap
);
656 #define bombout(msg) ( ssh->state = SSH_STATE_CLOSED, \
657 (ssh->s ? sk_close(ssh->s), ssh->s = NULL : 0), \
658 logeventf msg, connection_fatal msg )
660 static int ssh_channelcmp(void *av
, void *bv
)
662 struct ssh_channel
*a
= (struct ssh_channel
*) av
;
663 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
664 if (a
->localid
< b
->localid
)
666 if (a
->localid
> b
->localid
)
670 static int ssh_channelfind(void *av
, void *bv
)
672 unsigned *a
= (unsigned *) av
;
673 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
681 static int ssh_rportcmp_ssh1(void *av
, void *bv
)
683 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
684 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
686 if ( (i
= strcmp(a
->dhost
, b
->dhost
)) != 0)
687 return i
< 0 ?
-1 : +1;
688 if (a
->dport
> b
->dport
)
690 if (a
->dport
< b
->dport
)
695 static int ssh_rportcmp_ssh2(void *av
, void *bv
)
697 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
698 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
700 if (a
->sport
> b
->sport
)
702 if (a
->sport
< b
->sport
)
707 static int alloc_channel_id(Ssh ssh
)
709 const unsigned CHANNEL_NUMBER_OFFSET
= 256;
710 unsigned low
, high
, mid
;
712 struct ssh_channel
*c
;
715 * First-fit allocation of channel numbers: always pick the
716 * lowest unused one. To do this, binary-search using the
717 * counted B-tree to find the largest channel ID which is in a
718 * contiguous sequence from the beginning. (Precisely
719 * everything in that sequence must have ID equal to its tree
720 * index plus CHANNEL_NUMBER_OFFSET.)
722 tsize
= count234(ssh
->channels
);
726 while (high
- low
> 1) {
727 mid
= (high
+ low
) / 2;
728 c
= index234(ssh
->channels
, mid
);
729 if (c
->localid
== mid
+ CHANNEL_NUMBER_OFFSET
)
730 low
= mid
; /* this one is fine */
732 high
= mid
; /* this one is past it */
735 * Now low points to either -1, or the tree index of the
736 * largest ID in the initial sequence.
739 unsigned i
= low
+ 1 + CHANNEL_NUMBER_OFFSET
;
740 assert(NULL
== find234(ssh
->channels
, &i
, ssh_channelfind
));
742 return low
+ 1 + CHANNEL_NUMBER_OFFSET
;
745 static void c_write(Ssh ssh
, char *buf
, int len
)
747 if ((flags
& FLAG_STDERR
)) {
749 for (i
= 0; i
< len
; i
++)
751 fputc(buf
[i
], stderr
);
754 from_backend(ssh
->frontend
, 1, buf
, len
);
757 static void c_write_untrusted(Ssh ssh
, char *buf
, int len
)
760 for (i
= 0; i
< len
; i
++) {
762 c_write(ssh
, "\r\n", 2);
763 else if ((buf
[i
] & 0x60) || (buf
[i
] == '\r'))
764 c_write(ssh
, buf
+ i
, 1);
768 static void c_write_str(Ssh ssh
, char *buf
)
770 c_write(ssh
, buf
, strlen(buf
));
774 * Collect incoming data in the incoming packet buffer.
775 * Decipher and verify the packet when it is completely read.
776 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
777 * Update the *data and *datalen variables.
778 * Return the additional nr of bytes needed, or 0 when
779 * a complete packet is available.
781 static int ssh1_rdpkt(Ssh ssh
, unsigned char **data
, int *datalen
)
783 struct rdpkt1_state_tag
*st
= &ssh
->rdpkt1_state
;
785 crBegin(ssh
->ssh1_rdpkt_crstate
);
790 ssh
->pktin
.length
= 0;
792 for (st
->i
= st
->len
= 0; st
->i
< 4; st
->i
++) {
793 while ((*datalen
) == 0)
795 st
->len
= (st
->len
<< 8) + **data
;
796 (*data
)++, (*datalen
)--;
799 st
->pad
= 8 - (st
->len
% 8);
800 st
->biglen
= st
->len
+ st
->pad
;
801 ssh
->pktin
.length
= st
->len
- 5;
803 if (ssh
->pktin
.maxlen
< st
->biglen
) {
804 ssh
->pktin
.maxlen
= st
->biglen
;
805 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
, st
->biglen
+ APIEXTRA
);
808 st
->to_read
= st
->biglen
;
809 st
->p
= ssh
->pktin
.data
;
810 while (st
->to_read
> 0) {
811 st
->chunk
= st
->to_read
;
812 while ((*datalen
) == 0)
813 crReturn(st
->to_read
);
814 if (st
->chunk
> (*datalen
))
815 st
->chunk
= (*datalen
);
816 memcpy(st
->p
, *data
, st
->chunk
);
818 *datalen
-= st
->chunk
;
820 st
->to_read
-= st
->chunk
;
823 if (ssh
->cipher
&& detect_attack(ssh
->crcda_ctx
, ssh
->pktin
.data
,
825 bombout((ssh
,"Network attack (CRC compensation) detected!"));
830 ssh
->cipher
->decrypt(ssh
->v1_cipher_ctx
, ssh
->pktin
.data
, st
->biglen
);
832 st
->realcrc
= crc32(ssh
->pktin
.data
, st
->biglen
- 4);
833 st
->gotcrc
= GET_32BIT(ssh
->pktin
.data
+ st
->biglen
- 4);
834 if (st
->gotcrc
!= st
->realcrc
) {
835 bombout((ssh
,"Incorrect CRC received on packet"));
839 ssh
->pktin
.body
= ssh
->pktin
.data
+ st
->pad
+ 1;
841 if (ssh
->v1_compressing
) {
842 unsigned char *decompblk
;
844 zlib_decompress_block(ssh
->sc_comp_ctx
,
845 ssh
->pktin
.body
- 1, ssh
->pktin
.length
+ 1,
846 &decompblk
, &decomplen
);
848 if (ssh
->pktin
.maxlen
< st
->pad
+ decomplen
) {
849 ssh
->pktin
.maxlen
= st
->pad
+ decomplen
;
850 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
,
851 ssh
->pktin
.maxlen
+ APIEXTRA
);
852 ssh
->pktin
.body
= ssh
->pktin
.data
+ st
->pad
+ 1;
855 memcpy(ssh
->pktin
.body
- 1, decompblk
, decomplen
);
857 ssh
->pktin
.length
= decomplen
- 1;
860 ssh
->pktin
.type
= ssh
->pktin
.body
[-1];
863 log_packet(ssh
->logctx
,
864 PKT_INCOMING
, ssh
->pktin
.type
,
865 ssh1_pkt_type(ssh
->pktin
.type
),
866 ssh
->pktin
.body
, ssh
->pktin
.length
);
868 if (ssh
->pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
869 ssh
->pktin
.type
== SSH1_SMSG_STDERR_DATA
||
870 ssh
->pktin
.type
== SSH1_MSG_DEBUG
||
871 ssh
->pktin
.type
== SSH1_SMSG_AUTH_TIS_CHALLENGE
||
872 ssh
->pktin
.type
== SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
873 long stringlen
= GET_32BIT(ssh
->pktin
.body
);
874 if (stringlen
+ 4 != ssh
->pktin
.length
) {
875 bombout((ssh
,"Received data packet with bogus string length"));
880 if (ssh
->pktin
.type
== SSH1_MSG_DEBUG
) {
881 /* log debug message */
883 int stringlen
= GET_32BIT(ssh
->pktin
.body
);
884 strcpy(buf
, "Remote debug message: ");
887 memcpy(buf
+ 8, ssh
->pktin
.body
+ 4, stringlen
);
888 buf
[8 + stringlen
] = '\0';
891 } else if (ssh
->pktin
.type
== SSH1_MSG_IGNORE
) {
896 if (ssh
->pktin
.type
== SSH1_MSG_DISCONNECT
) {
897 /* log reason code in disconnect message */
899 unsigned msglen
= GET_32BIT(ssh
->pktin
.body
);
901 strcpy(buf
, "Remote sent disconnect: ");
902 nowlen
= strlen(buf
);
903 if (msglen
> sizeof(buf
) - nowlen
- 1)
904 msglen
= sizeof(buf
) - nowlen
- 1;
905 memcpy(buf
+ nowlen
, ssh
->pktin
.body
+ 4, msglen
);
906 buf
[nowlen
+ msglen
] = '\0';
907 /* logevent(buf); (this is now done within the bombout macro) */
908 bombout((ssh
,"Server sent disconnect message:\n\"%s\"", buf
+nowlen
));
915 static int ssh2_rdpkt(Ssh ssh
, unsigned char **data
, int *datalen
)
917 struct rdpkt2_state_tag
*st
= &ssh
->rdpkt2_state
;
919 crBegin(ssh
->ssh2_rdpkt_crstate
);
923 ssh
->pktin
.length
= 0;
925 st
->cipherblk
= ssh
->sccipher
->blksize
;
928 if (st
->cipherblk
< 8)
931 if (ssh
->pktin
.maxlen
< st
->cipherblk
) {
932 ssh
->pktin
.maxlen
= st
->cipherblk
;
933 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
, st
->cipherblk
+ APIEXTRA
);
937 * Acquire and decrypt the first block of the packet. This will
938 * contain the length and padding details.
940 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
941 while ((*datalen
) == 0)
942 crReturn(st
->cipherblk
- st
->i
);
943 ssh
->pktin
.data
[st
->i
] = *(*data
)++;
948 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
949 ssh
->pktin
.data
, st
->cipherblk
);
952 * Now get the length and padding figures.
954 st
->len
= GET_32BIT(ssh
->pktin
.data
);
955 st
->pad
= ssh
->pktin
.data
[4];
958 * _Completely_ silly lengths should be stomped on before they
959 * do us any more damage.
961 if (st
->len
< 0 || st
->pad
< 0 || st
->len
+ st
->pad
< 0) {
962 bombout((ssh
,"Incoming packet was garbled on decryption"));
967 * This enables us to deduce the payload length.
969 st
->payload
= st
->len
- st
->pad
- 1;
971 ssh
->pktin
.length
= st
->payload
+ 5;
974 * So now we can work out the total packet length.
976 st
->packetlen
= st
->len
+ 4;
977 st
->maclen
= ssh
->scmac ? ssh
->scmac
->len
: 0;
980 * Adjust memory allocation if packet is too big.
982 if (ssh
->pktin
.maxlen
< st
->packetlen
+ st
->maclen
) {
983 ssh
->pktin
.maxlen
= st
->packetlen
+ st
->maclen
;
984 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
,
985 ssh
->pktin
.maxlen
+ APIEXTRA
);
989 * Read and decrypt the remainder of the packet.
991 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
;
993 while ((*datalen
) == 0)
994 crReturn(st
->packetlen
+ st
->maclen
- st
->i
);
995 ssh
->pktin
.data
[st
->i
] = *(*data
)++;
998 /* Decrypt everything _except_ the MAC. */
1000 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
1001 ssh
->pktin
.data
+ st
->cipherblk
,
1002 st
->packetlen
- st
->cipherblk
);
1008 && !ssh
->scmac
->verify(ssh
->sc_mac_ctx
, ssh
->pktin
.data
, st
->len
+ 4,
1009 st
->incoming_sequence
)) {
1010 bombout((ssh
,"Incorrect MAC received on packet"));
1013 st
->incoming_sequence
++; /* whether or not we MACed */
1016 * Decompress packet payload.
1019 unsigned char *newpayload
;
1022 ssh
->sccomp
->decompress(ssh
->sc_comp_ctx
,
1023 ssh
->pktin
.data
+ 5, ssh
->pktin
.length
- 5,
1024 &newpayload
, &newlen
)) {
1025 if (ssh
->pktin
.maxlen
< newlen
+ 5) {
1026 ssh
->pktin
.maxlen
= newlen
+ 5;
1027 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
,
1028 ssh
->pktin
.maxlen
+ APIEXTRA
);
1030 ssh
->pktin
.length
= 5 + newlen
;
1031 memcpy(ssh
->pktin
.data
+ 5, newpayload
, newlen
);
1036 ssh
->pktin
.savedpos
= 6;
1037 ssh
->pktin
.type
= ssh
->pktin
.data
[5];
1040 log_packet(ssh
->logctx
, PKT_INCOMING
, ssh
->pktin
.type
,
1041 ssh2_pkt_type(ssh
->pkt_ctx
, ssh
->pktin
.type
),
1042 ssh
->pktin
.data
+6, ssh
->pktin
.length
-6);
1044 switch (ssh
->pktin
.type
) {
1046 * These packets we must handle instantly.
1048 case SSH2_MSG_DISCONNECT
:
1050 /* log reason code in disconnect message */
1053 int reason
= GET_32BIT(ssh
->pktin
.data
+ 6);
1054 unsigned msglen
= GET_32BIT(ssh
->pktin
.data
+ 10);
1056 if (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) {
1057 buf
= dupprintf("Received disconnect message (%s)",
1058 ssh2_disconnect_reasons
[reason
]);
1060 buf
= dupprintf("Received disconnect message (unknown"
1061 " type %d)", reason
);
1065 buf
= dupprintf("Disconnection message text: %n%.*s",
1066 &nowlen
, msglen
, ssh
->pktin
.data
+ 14);
1068 bombout((ssh
,"Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1070 (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) ?
1071 ssh2_disconnect_reasons
[reason
] : "unknown",
1077 case SSH2_MSG_IGNORE
:
1079 case SSH2_MSG_DEBUG
:
1081 /* log the debug message */
1083 /* int display = ssh->pktin.body[6]; */
1084 int stringlen
= GET_32BIT(ssh
->pktin
.data
+7);
1086 strcpy(buf
, "Remote debug message: ");
1087 prefix
= strlen(buf
);
1088 if (stringlen
> (int)(sizeof(buf
)-prefix
-1))
1089 stringlen
= sizeof(buf
)-prefix
-1;
1090 memcpy(buf
+ prefix
, ssh
->pktin
.data
+ 11, stringlen
);
1091 buf
[prefix
+ stringlen
] = '\0';
1094 goto next_packet
; /* FIXME: print the debug message */
1097 * These packets we need do nothing about here.
1099 case SSH2_MSG_UNIMPLEMENTED
:
1100 case SSH2_MSG_SERVICE_REQUEST
:
1101 case SSH2_MSG_SERVICE_ACCEPT
:
1102 case SSH2_MSG_KEXINIT
:
1103 case SSH2_MSG_NEWKEYS
:
1104 case SSH2_MSG_KEXDH_INIT
:
1105 case SSH2_MSG_KEXDH_REPLY
:
1106 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1107 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1108 case SSH2_MSG_KEX_DH_GEX_INIT
:
1109 case SSH2_MSG_KEX_DH_GEX_REPLY
:
1110 case SSH2_MSG_USERAUTH_REQUEST
:
1111 case SSH2_MSG_USERAUTH_FAILURE
:
1112 case SSH2_MSG_USERAUTH_SUCCESS
:
1113 case SSH2_MSG_USERAUTH_BANNER
:
1114 case SSH2_MSG_USERAUTH_PK_OK
:
1115 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1116 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1117 case SSH2_MSG_USERAUTH_INFO_RESPONSE
:
1118 case SSH2_MSG_GLOBAL_REQUEST
:
1119 case SSH2_MSG_REQUEST_SUCCESS
:
1120 case SSH2_MSG_REQUEST_FAILURE
:
1121 case SSH2_MSG_CHANNEL_OPEN
:
1122 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
:
1123 case SSH2_MSG_CHANNEL_OPEN_FAILURE
:
1124 case SSH2_MSG_CHANNEL_WINDOW_ADJUST
:
1125 case SSH2_MSG_CHANNEL_DATA
:
1126 case SSH2_MSG_CHANNEL_EXTENDED_DATA
:
1127 case SSH2_MSG_CHANNEL_EOF
:
1128 case SSH2_MSG_CHANNEL_CLOSE
:
1129 case SSH2_MSG_CHANNEL_REQUEST
:
1130 case SSH2_MSG_CHANNEL_SUCCESS
:
1131 case SSH2_MSG_CHANNEL_FAILURE
:
1135 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1138 ssh2_pkt_init(ssh
, SSH2_MSG_UNIMPLEMENTED
);
1139 ssh2_pkt_adduint32(ssh
, st
->incoming_sequence
- 1);
1147 static void ssh1_pktout_size(Ssh ssh
, int len
)
1151 len
+= 5; /* type and CRC */
1152 pad
= 8 - (len
% 8);
1155 ssh
->pktout
.length
= len
- 5;
1156 if (ssh
->pktout
.maxlen
< biglen
) {
1157 ssh
->pktout
.maxlen
= biglen
;
1159 /* Allocate enough buffer space for extra block
1160 * for MS CryptEncrypt() */
1161 ssh
->pktout
.data
= srealloc(ssh
->pktout
.data
, biglen
+ 12);
1163 ssh
->pktout
.data
= srealloc(ssh
->pktout
.data
, biglen
+ 4);
1166 ssh
->pktout
.body
= ssh
->pktout
.data
+ 4 + pad
+ 1;
1169 static void s_wrpkt_start(Ssh ssh
, int type
, int len
)
1171 ssh1_pktout_size(ssh
, len
);
1172 ssh
->pktout
.type
= type
;
1175 static int s_wrpkt_prepare(Ssh ssh
)
1177 int pad
, len
, biglen
, i
;
1180 ssh
->pktout
.body
[-1] = ssh
->pktout
.type
;
1183 log_packet(ssh
->logctx
, PKT_OUTGOING
, ssh
->pktout
.type
,
1184 ssh1_pkt_type(ssh
->pktout
.type
),
1185 ssh
->pktout
.body
, ssh
->pktout
.length
);
1187 if (ssh
->v1_compressing
) {
1188 unsigned char *compblk
;
1190 zlib_compress_block(ssh
->cs_comp_ctx
,
1191 ssh
->pktout
.body
- 1, ssh
->pktout
.length
+ 1,
1192 &compblk
, &complen
);
1193 ssh1_pktout_size(ssh
, complen
- 1);
1194 memcpy(ssh
->pktout
.body
- 1, compblk
, complen
);
1198 len
= ssh
->pktout
.length
+ 5; /* type and CRC */
1199 pad
= 8 - (len
% 8);
1202 for (i
= 0; i
< pad
; i
++)
1203 ssh
->pktout
.data
[i
+ 4] = random_byte();
1204 crc
= crc32(ssh
->pktout
.data
+ 4, biglen
- 4);
1205 PUT_32BIT(ssh
->pktout
.data
+ biglen
, crc
);
1206 PUT_32BIT(ssh
->pktout
.data
, len
);
1209 ssh
->cipher
->encrypt(ssh
->v1_cipher_ctx
, ssh
->pktout
.data
+ 4, biglen
);
1214 static void s_wrpkt(Ssh ssh
)
1217 len
= s_wrpkt_prepare(ssh
);
1218 backlog
= sk_write(ssh
->s
, ssh
->pktout
.data
, len
);
1219 if (backlog
> SSH_MAX_BACKLOG
)
1220 ssh_throttle_all(ssh
, 1, backlog
);
1223 static void s_wrpkt_defer(Ssh ssh
)
1226 len
= s_wrpkt_prepare(ssh
);
1227 if (ssh
->deferred_len
+ len
> ssh
->deferred_size
) {
1228 ssh
->deferred_size
= ssh
->deferred_len
+ len
+ 128;
1229 ssh
->deferred_send_data
= srealloc(ssh
->deferred_send_data
,
1230 ssh
->deferred_size
);
1232 memcpy(ssh
->deferred_send_data
+ ssh
->deferred_len
, ssh
->pktout
.data
, len
);
1233 ssh
->deferred_len
+= len
;
1237 * Construct a packet with the specified contents.
1239 static void construct_packet(Ssh ssh
, int pkttype
, va_list ap1
, va_list ap2
)
1241 unsigned char *p
, *argp
, argchar
;
1242 unsigned long argint
;
1243 int pktlen
, argtype
, arglen
;
1247 while ((argtype
= va_arg(ap1
, int)) != PKT_END
) {
1250 (void) va_arg(ap1
, int);
1254 (void) va_arg(ap1
, int);
1258 (void) va_arg(ap1
, unsigned char *);
1259 arglen
= va_arg(ap1
, int);
1263 argp
= va_arg(ap1
, unsigned char *);
1264 arglen
= strlen(argp
);
1265 pktlen
+= 4 + arglen
;
1268 bn
= va_arg(ap1
, Bignum
);
1269 pktlen
+= ssh1_bignum_length(bn
);
1276 s_wrpkt_start(ssh
, pkttype
, pktlen
);
1277 p
= ssh
->pktout
.body
;
1279 while ((argtype
= va_arg(ap2
, int)) != PKT_END
) {
1282 argint
= va_arg(ap2
, int);
1283 PUT_32BIT(p
, argint
);
1287 argchar
= (unsigned char) va_arg(ap2
, int);
1292 argp
= va_arg(ap2
, unsigned char *);
1293 arglen
= va_arg(ap2
, int);
1294 memcpy(p
, argp
, arglen
);
1298 argp
= va_arg(ap2
, unsigned char *);
1299 arglen
= strlen(argp
);
1300 PUT_32BIT(p
, arglen
);
1301 memcpy(p
+ 4, argp
, arglen
);
1305 bn
= va_arg(ap2
, Bignum
);
1306 p
+= ssh1_write_bignum(p
, bn
);
1312 static void send_packet(Ssh ssh
, int pkttype
, ...)
1315 va_start(ap1
, pkttype
);
1316 va_start(ap2
, pkttype
);
1317 construct_packet(ssh
, pkttype
, ap1
, ap2
);
1321 static void defer_packet(Ssh ssh
, int pkttype
, ...)
1324 va_start(ap1
, pkttype
);
1325 va_start(ap2
, pkttype
);
1326 construct_packet(ssh
, pkttype
, ap1
, ap2
);
1330 static int ssh_versioncmp(char *a
, char *b
)
1333 unsigned long av
, bv
;
1335 av
= strtoul(a
, &ae
, 10);
1336 bv
= strtoul(b
, &be
, 10);
1338 return (av
< bv ?
-1 : +1);
1343 av
= strtoul(ae
, &ae
, 10);
1344 bv
= strtoul(be
, &be
, 10);
1346 return (av
< bv ?
-1 : +1);
1351 * Utility routines for putting an SSH-protocol `string' and
1352 * `uint32' into a SHA state.
1355 static void sha_string(SHA_State
* s
, void *str
, int len
)
1357 unsigned char lenblk
[4];
1358 PUT_32BIT(lenblk
, len
);
1359 SHA_Bytes(s
, lenblk
, 4);
1360 SHA_Bytes(s
, str
, len
);
1363 static void sha_uint32(SHA_State
* s
, unsigned i
)
1365 unsigned char intblk
[4];
1366 PUT_32BIT(intblk
, i
);
1367 SHA_Bytes(s
, intblk
, 4);
1371 * SSH2 packet construction functions.
1373 static void ssh2_pkt_ensure(Ssh ssh
, int length
)
1375 if (ssh
->pktout
.maxlen
< length
) {
1376 ssh
->pktout
.maxlen
= length
+ 256;
1377 ssh
->pktout
.data
= srealloc(ssh
->pktout
.data
,
1378 ssh
->pktout
.maxlen
+ APIEXTRA
);
1379 if (!ssh
->pktout
.data
)
1380 fatalbox("Out of memory");
1383 static void ssh2_pkt_adddata(Ssh ssh
, void *data
, int len
)
1385 ssh
->pktout
.length
+= len
;
1386 ssh2_pkt_ensure(ssh
, ssh
->pktout
.length
);
1387 memcpy(ssh
->pktout
.data
+ ssh
->pktout
.length
- len
, data
, len
);
1389 static void ssh2_pkt_addbyte(Ssh ssh
, unsigned char byte
)
1391 ssh2_pkt_adddata(ssh
, &byte
, 1);
1393 static void ssh2_pkt_init(Ssh ssh
, int pkt_type
)
1395 ssh
->pktout
.length
= 5;
1396 ssh2_pkt_addbyte(ssh
, (unsigned char) pkt_type
);
1398 static void ssh2_pkt_addbool(Ssh ssh
, unsigned char value
)
1400 ssh2_pkt_adddata(ssh
, &value
, 1);
1402 static void ssh2_pkt_adduint32(Ssh ssh
, unsigned long value
)
1405 PUT_32BIT(x
, value
);
1406 ssh2_pkt_adddata(ssh
, x
, 4);
1408 static void ssh2_pkt_addstring_start(Ssh ssh
)
1410 ssh2_pkt_adduint32(ssh
, 0);
1411 ssh
->pktout
.savedpos
= ssh
->pktout
.length
;
1413 static void ssh2_pkt_addstring_str(Ssh ssh
, char *data
)
1415 ssh2_pkt_adddata(ssh
, data
, strlen(data
));
1416 PUT_32BIT(ssh
->pktout
.data
+ ssh
->pktout
.savedpos
- 4,
1417 ssh
->pktout
.length
- ssh
->pktout
.savedpos
);
1419 static void ssh2_pkt_addstring_data(Ssh ssh
, char *data
, int len
)
1421 ssh2_pkt_adddata(ssh
, data
, len
);
1422 PUT_32BIT(ssh
->pktout
.data
+ ssh
->pktout
.savedpos
- 4,
1423 ssh
->pktout
.length
- ssh
->pktout
.savedpos
);
1425 static void ssh2_pkt_addstring(Ssh ssh
, char *data
)
1427 ssh2_pkt_addstring_start(ssh
);
1428 ssh2_pkt_addstring_str(ssh
, data
);
1430 static char *ssh2_mpint_fmt(Bignum b
, int *len
)
1433 int i
, n
= (bignum_bitcount(b
) + 7) / 8;
1436 fatalbox("out of memory");
1438 for (i
= 1; i
<= n
; i
++)
1439 p
[i
] = bignum_byte(b
, n
- i
);
1441 while (i
<= n
&& p
[i
] == 0 && (p
[i
+ 1] & 0x80) == 0)
1443 memmove(p
, p
+ i
, n
+ 1 - i
);
1447 static void ssh2_pkt_addmp(Ssh ssh
, Bignum b
)
1451 p
= ssh2_mpint_fmt(b
, &len
);
1452 ssh2_pkt_addstring_start(ssh
);
1453 ssh2_pkt_addstring_data(ssh
, p
, len
);
1458 * Construct an SSH2 final-form packet: compress it, encrypt it,
1459 * put the MAC on it. Final packet, ready to be sent, is stored in
1460 * ssh->pktout.data. Total length is returned.
1462 static int ssh2_pkt_construct(Ssh ssh
)
1464 int cipherblk
, maclen
, padding
, i
;
1467 log_packet(ssh
->logctx
, PKT_OUTGOING
, ssh
->pktout
.data
[5],
1468 ssh2_pkt_type(ssh
->pkt_ctx
, ssh
->pktout
.data
[5]),
1469 ssh
->pktout
.data
+ 6, ssh
->pktout
.length
- 6);
1472 * Compress packet payload.
1475 unsigned char *newpayload
;
1478 ssh
->cscomp
->compress(ssh
->cs_comp_ctx
, ssh
->pktout
.data
+ 5,
1479 ssh
->pktout
.length
- 5,
1480 &newpayload
, &newlen
)) {
1481 ssh
->pktout
.length
= 5;
1482 ssh2_pkt_adddata(ssh
, newpayload
, newlen
);
1488 * Add padding. At least four bytes, and must also bring total
1489 * length (minus MAC) up to a multiple of the block size.
1491 cipherblk
= ssh
->cscipher ? ssh
->cscipher
->blksize
: 8; /* block size */
1492 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
1495 (cipherblk
- (ssh
->pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
1496 maclen
= ssh
->csmac ? ssh
->csmac
->len
: 0;
1497 ssh2_pkt_ensure(ssh
, ssh
->pktout
.length
+ padding
+ maclen
);
1498 ssh
->pktout
.data
[4] = padding
;
1499 for (i
= 0; i
< padding
; i
++)
1500 ssh
->pktout
.data
[ssh
->pktout
.length
+ i
] = random_byte();
1501 PUT_32BIT(ssh
->pktout
.data
, ssh
->pktout
.length
+ padding
- 4);
1503 ssh
->csmac
->generate(ssh
->cs_mac_ctx
, ssh
->pktout
.data
,
1504 ssh
->pktout
.length
+ padding
,
1505 ssh
->v2_outgoing_sequence
);
1506 ssh
->v2_outgoing_sequence
++; /* whether or not we MACed */
1509 ssh
->cscipher
->encrypt(ssh
->cs_cipher_ctx
,
1510 ssh
->pktout
.data
, ssh
->pktout
.length
+ padding
);
1512 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1513 return ssh
->pktout
.length
+ padding
+ maclen
;
1517 * Construct and send an SSH2 packet immediately.
1519 static void ssh2_pkt_send(Ssh ssh
)
1523 len
= ssh2_pkt_construct(ssh
);
1524 backlog
= sk_write(ssh
->s
, ssh
->pktout
.data
, len
);
1525 if (backlog
> SSH_MAX_BACKLOG
)
1526 ssh_throttle_all(ssh
, 1, backlog
);
1530 * Construct an SSH2 packet and add it to a deferred data block.
1531 * Useful for sending multiple packets in a single sk_write() call,
1532 * to prevent a traffic-analysing listener from being able to work
1533 * out the length of any particular packet (such as the password
1536 * Note that because SSH2 sequence-numbers its packets, this can
1537 * NOT be used as an m4-style `defer' allowing packets to be
1538 * constructed in one order and sent in another.
1540 static void ssh2_pkt_defer(Ssh ssh
)
1542 int len
= ssh2_pkt_construct(ssh
);
1543 if (ssh
->deferred_len
+ len
> ssh
->deferred_size
) {
1544 ssh
->deferred_size
= ssh
->deferred_len
+ len
+ 128;
1545 ssh
->deferred_send_data
= srealloc(ssh
->deferred_send_data
,
1546 ssh
->deferred_size
);
1548 memcpy(ssh
->deferred_send_data
+ ssh
->deferred_len
, ssh
->pktout
.data
, len
);
1549 ssh
->deferred_len
+= len
;
1553 * Send the whole deferred data block constructed by
1554 * ssh2_pkt_defer() or SSH1's defer_packet().
1556 static void ssh_pkt_defersend(Ssh ssh
)
1559 backlog
= sk_write(ssh
->s
, ssh
->deferred_send_data
, ssh
->deferred_len
);
1560 ssh
->deferred_len
= ssh
->deferred_size
= 0;
1561 sfree(ssh
->deferred_send_data
);
1562 ssh
->deferred_send_data
= NULL
;
1563 if (backlog
> SSH_MAX_BACKLOG
)
1564 ssh_throttle_all(ssh
, 1, backlog
);
1568 void bndebug(char *string
, Bignum b
)
1572 p
= ssh2_mpint_fmt(b
, &len
);
1573 debug(("%s", string
));
1574 for (i
= 0; i
< len
; i
++)
1575 debug((" %02x", p
[i
]));
1581 static void sha_mpint(SHA_State
* s
, Bignum b
)
1585 p
= ssh2_mpint_fmt(b
, &len
);
1586 sha_string(s
, p
, len
);
1591 * SSH2 packet decode functions.
1593 static unsigned long ssh2_pkt_getuint32(Ssh ssh
)
1595 unsigned long value
;
1596 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< 4)
1597 return 0; /* arrgh, no way to decline (FIXME?) */
1598 value
= GET_32BIT(ssh
->pktin
.data
+ ssh
->pktin
.savedpos
);
1599 ssh
->pktin
.savedpos
+= 4;
1602 static int ssh2_pkt_getbool(Ssh ssh
)
1604 unsigned long value
;
1605 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< 1)
1606 return 0; /* arrgh, no way to decline (FIXME?) */
1607 value
= ssh
->pktin
.data
[ssh
->pktin
.savedpos
] != 0;
1608 ssh
->pktin
.savedpos
++;
1611 static void ssh2_pkt_getstring(Ssh ssh
, char **p
, int *length
)
1616 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< 4)
1618 len
= GET_32BIT(ssh
->pktin
.data
+ ssh
->pktin
.savedpos
);
1622 ssh
->pktin
.savedpos
+= 4;
1623 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< *length
)
1625 *p
= ssh
->pktin
.data
+ ssh
->pktin
.savedpos
;
1626 ssh
->pktin
.savedpos
+= *length
;
1628 static Bignum
ssh2_pkt_getmp(Ssh ssh
)
1634 ssh2_pkt_getstring(ssh
, &p
, &length
);
1638 bombout((ssh
,"internal error: Can't handle negative mpints"));
1641 b
= bignum_from_bytes(p
, length
);
1646 * Helper function to add an SSH2 signature blob to a packet.
1647 * Expects to be shown the public key blob as well as the signature
1648 * blob. Normally works just like ssh2_pkt_addstring, but will
1649 * fiddle with the signature packet if necessary for
1650 * BUG_SSH2_RSA_PADDING.
1652 static void ssh2_add_sigblob(Ssh ssh
, void *pkblob_v
, int pkblob_len
,
1653 void *sigblob_v
, int sigblob_len
)
1655 unsigned char *pkblob
= (unsigned char *)pkblob_v
;
1656 unsigned char *sigblob
= (unsigned char *)sigblob_v
;
1658 /* dmemdump(pkblob, pkblob_len); */
1659 /* dmemdump(sigblob, sigblob_len); */
1662 * See if this is in fact an ssh-rsa signature and a buggy
1663 * server; otherwise we can just do this the easy way.
1665 if ((ssh
->remote_bugs
& BUG_SSH2_RSA_PADDING
) &&
1666 (GET_32BIT(pkblob
) == 7 && !memcmp(pkblob
+4, "ssh-rsa", 7))) {
1667 int pos
, len
, siglen
;
1670 * Find the byte length of the modulus.
1673 pos
= 4+7; /* skip over "ssh-rsa" */
1674 pos
+= 4 + GET_32BIT(pkblob
+pos
); /* skip over exponent */
1675 len
= GET_32BIT(pkblob
+pos
); /* find length of modulus */
1676 pos
+= 4; /* find modulus itself */
1677 while (len
> 0 && pkblob
[pos
] == 0)
1679 /* debug(("modulus length is %d\n", len)); */
1682 * Now find the signature integer.
1684 pos
= 4+7; /* skip over "ssh-rsa" */
1685 siglen
= GET_32BIT(sigblob
+pos
);
1686 /* debug(("signature length is %d\n", siglen)); */
1688 if (len
!= siglen
) {
1689 unsigned char newlen
[4];
1690 ssh2_pkt_addstring_start(ssh
);
1691 ssh2_pkt_addstring_data(ssh
, sigblob
, pos
);
1692 /* dmemdump(sigblob, pos); */
1693 pos
+= 4; /* point to start of actual sig */
1694 PUT_32BIT(newlen
, len
);
1695 ssh2_pkt_addstring_data(ssh
, newlen
, 4);
1696 /* dmemdump(newlen, 4); */
1698 while (len
-- > siglen
) {
1699 ssh2_pkt_addstring_data(ssh
, newlen
, 1);
1700 /* dmemdump(newlen, 1); */
1702 ssh2_pkt_addstring_data(ssh
, sigblob
+pos
, siglen
);
1703 /* dmemdump(sigblob+pos, siglen); */
1707 /* Otherwise fall through and do it the easy way. */
1710 ssh2_pkt_addstring_start(ssh
);
1711 ssh2_pkt_addstring_data(ssh
, sigblob
, sigblob_len
);
1715 * Examine the remote side's version string and compare it against
1716 * a list of known buggy implementations.
1718 static void ssh_detect_bugs(Ssh ssh
, char *vstring
)
1720 char *imp
; /* pointer to implementation part */
1722 imp
+= strcspn(imp
, "-");
1724 imp
+= strcspn(imp
, "-");
1727 ssh
->remote_bugs
= 0;
1729 if (cfg
.sshbug_ignore1
== BUG_ON
||
1730 (cfg
.sshbug_ignore1
== BUG_AUTO
&&
1731 (!strcmp(imp
, "1.2.18") || !strcmp(imp
, "1.2.19") ||
1732 !strcmp(imp
, "1.2.20") || !strcmp(imp
, "1.2.21") ||
1733 !strcmp(imp
, "1.2.22") || !strcmp(imp
, "Cisco-1.25")))) {
1735 * These versions don't support SSH1_MSG_IGNORE, so we have
1736 * to use a different defence against password length
1739 ssh
->remote_bugs
|= BUG_CHOKES_ON_SSH1_IGNORE
;
1740 logevent("We believe remote version has SSH1 ignore bug");
1743 if (cfg
.sshbug_plainpw1
== BUG_ON
||
1744 (cfg
.sshbug_plainpw1
== BUG_AUTO
&&
1745 (!strcmp(imp
, "Cisco-1.25")))) {
1747 * These versions need a plain password sent; they can't
1748 * handle having a null and a random length of data after
1751 ssh
->remote_bugs
|= BUG_NEEDS_SSH1_PLAIN_PASSWORD
;
1752 logevent("We believe remote version needs a plain SSH1 password");
1755 if (cfg
.sshbug_rsa1
== BUG_ON
||
1756 (cfg
.sshbug_rsa1
== BUG_AUTO
&&
1757 (!strcmp(imp
, "Cisco-1.25")))) {
1759 * These versions apparently have no clue whatever about
1760 * RSA authentication and will panic and die if they see
1761 * an AUTH_RSA message.
1763 ssh
->remote_bugs
|= BUG_CHOKES_ON_RSA
;
1764 logevent("We believe remote version can't handle RSA authentication");
1767 if (cfg
.sshbug_hmac2
== BUG_ON
||
1768 (cfg
.sshbug_hmac2
== BUG_AUTO
&&
1769 (wc_match("2.1.0*", imp
) || wc_match("2.0.*", imp
) ||
1770 wc_match("2.2.0*", imp
) || wc_match("2.3.0*", imp
) ||
1771 wc_match("2.1 *", imp
)))) {
1773 * These versions have the HMAC bug.
1775 ssh
->remote_bugs
|= BUG_SSH2_HMAC
;
1776 logevent("We believe remote version has SSH2 HMAC bug");
1779 if (cfg
.sshbug_derivekey2
== BUG_ON
||
1780 (cfg
.sshbug_derivekey2
== BUG_AUTO
&&
1781 (wc_match("2.0.0*", imp
) || wc_match("2.0.1[01]*", imp
) ))) {
1783 * These versions have the key-derivation bug (failing to
1784 * include the literal shared secret in the hashes that
1785 * generate the keys).
1787 ssh
->remote_bugs
|= BUG_SSH2_DERIVEKEY
;
1788 logevent("We believe remote version has SSH2 key-derivation bug");
1791 if (cfg
.sshbug_rsapad2
== BUG_ON
||
1792 (cfg
.sshbug_rsapad2
== BUG_AUTO
&&
1793 (wc_match("OpenSSH_2.[5-9]*", imp
) ||
1794 wc_match("OpenSSH_3.[0-2]*", imp
)))) {
1796 * These versions have the SSH2 RSA padding bug.
1798 ssh
->remote_bugs
|= BUG_SSH2_RSA_PADDING
;
1799 logevent("We believe remote version has SSH2 RSA padding bug");
1802 if (cfg
.sshbug_dhgex2
== BUG_ON
) {
1804 * User specified the SSH2 DH GEX bug.
1806 ssh
->remote_bugs
|= BUG_SSH2_DH_GEX
;
1807 logevent("We believe remote version has SSH2 DH group exchange bug");
1811 static int do_ssh_init(Ssh ssh
, unsigned char c
)
1813 struct do_ssh_init_state
{
1821 crState(do_ssh_init_state
);
1823 crBegin(ssh
->do_ssh_init_crstate
);
1825 /* Search for the string "SSH-" in the input. */
1828 static const int transS
[] = { 1, 2, 2, 1 };
1829 static const int transH
[] = { 0, 0, 3, 0 };
1830 static const int transminus
[] = { 0, 0, 0, -1 };
1832 s
->i
= transS
[s
->i
];
1834 s
->i
= transH
[s
->i
];
1836 s
->i
= transminus
[s
->i
];
1841 crReturn(1); /* get another character */
1845 s
->vstring
= smalloc(s
->vstrsize
);
1846 strcpy(s
->vstring
, "SSH-");
1850 crReturn(1); /* get another char */
1851 if (s
->vslen
>= s
->vstrsize
- 1) {
1853 s
->vstring
= srealloc(s
->vstring
, s
->vstrsize
);
1855 s
->vstring
[s
->vslen
++] = c
;
1858 s
->version
[s
->i
] = '\0';
1860 } else if (s
->i
< sizeof(s
->version
) - 1)
1861 s
->version
[s
->i
++] = c
;
1862 } else if (c
== '\n')
1866 ssh
->agentfwd_enabled
= FALSE
;
1867 ssh
->rdpkt2_state
.incoming_sequence
= 0;
1869 s
->vstring
[s
->vslen
] = 0;
1870 s
->vstring
[strcspn(s
->vstring
, "\r\n")] = '\0';/* remove EOL chars */
1873 vlog
= smalloc(20 + s
->vslen
);
1874 sprintf(vlog
, "Server version: %s", s
->vstring
);
1878 ssh_detect_bugs(ssh
, s
->vstring
);
1881 * Decide which SSH protocol version to support.
1884 /* Anything strictly below "2.0" means protocol 1 is supported. */
1885 s
->proto1
= ssh_versioncmp(s
->version
, "2.0") < 0;
1886 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
1887 s
->proto2
= ssh_versioncmp(s
->version
, "1.99") >= 0;
1889 if (cfg
.sshprot
== 0 && !s
->proto1
) {
1890 bombout((ssh
,"SSH protocol version 1 required by user but not provided by server"));
1893 if (cfg
.sshprot
== 3 && !s
->proto2
) {
1894 bombout((ssh
,"SSH protocol version 2 required by user but not provided by server"));
1898 if (s
->proto2
&& (cfg
.sshprot
>= 2 || !s
->proto1
)) {
1902 char verstring
[80], vlog
[100];
1903 sprintf(verstring
, "SSH-2.0-%s", sshver
);
1904 SHA_Init(&ssh
->exhashbase
);
1906 * Hash our version string and their version string.
1908 sha_string(&ssh
->exhashbase
, verstring
, strlen(verstring
));
1909 sha_string(&ssh
->exhashbase
, s
->vstring
, strcspn(s
->vstring
, "\r\n"));
1910 sprintf(vlog
, "We claim version: %s", verstring
);
1912 strcat(verstring
, "\n");
1913 logevent("Using SSH protocol version 2");
1914 sk_write(ssh
->s
, verstring
, strlen(verstring
));
1915 ssh
->protocol
= ssh2_protocol
;
1917 ssh
->s_rdpkt
= ssh2_rdpkt
;
1922 char verstring
[80], vlog
[100];
1923 sprintf(verstring
, "SSH-%s-%s",
1924 (ssh_versioncmp(s
->version
, "1.5") <= 0 ? s
->version
: "1.5"),
1926 sprintf(vlog
, "We claim version: %s", verstring
);
1928 strcat(verstring
, "\n");
1930 logevent("Using SSH protocol version 1");
1931 sk_write(ssh
->s
, verstring
, strlen(verstring
));
1932 ssh
->protocol
= ssh1_protocol
;
1934 ssh
->s_rdpkt
= ssh1_rdpkt
;
1936 ssh
->state
= SSH_STATE_BEFORE_SIZE
;
1943 static void ssh_gotdata(Ssh ssh
, unsigned char *data
, int datalen
)
1945 crBegin(ssh
->ssh_gotdata_crstate
);
1948 * To begin with, feed the characters one by one to the
1949 * protocol initialisation / selection function do_ssh_init().
1950 * When that returns 0, we're done with the initial greeting
1951 * exchange and can move on to packet discipline.
1954 int ret
; /* need not be kept across crReturn */
1956 crReturnV
; /* more data please */
1957 ret
= do_ssh_init(ssh
, *data
);
1965 * We emerge from that loop when the initial negotiation is
1966 * over and we have selected an s_rdpkt function. Now pass
1967 * everything to s_rdpkt, and then pass the resulting packets
1968 * to the proper protocol handler.
1973 while (datalen
> 0) {
1974 if (ssh
->s_rdpkt(ssh
, &data
, &datalen
) == 0) {
1975 if (ssh
->state
== SSH_STATE_CLOSED
) {
1978 ssh
->protocol(ssh
, NULL
, 0, 1);
1979 if (ssh
->state
== SSH_STATE_CLOSED
) {
1989 static int ssh_closing(Plug plug
, char *error_msg
, int error_code
,
1992 Ssh ssh
= (Ssh
) plug
;
1993 ssh
->state
= SSH_STATE_CLOSED
;
1999 /* A socket error has occurred. */
2000 logevent(error_msg
);
2001 connection_fatal(ssh
->frontend
, error_msg
);
2003 /* Otherwise, the remote side closed the connection normally. */
2008 static int ssh_receive(Plug plug
, int urgent
, char *data
, int len
)
2010 Ssh ssh
= (Ssh
) plug
;
2011 ssh_gotdata(ssh
, data
, len
);
2012 if (ssh
->state
== SSH_STATE_CLOSED
) {
2022 static void ssh_sent(Plug plug
, int bufsize
)
2024 Ssh ssh
= (Ssh
) plug
;
2026 * If the send backlog on the SSH socket itself clears, we
2027 * should unthrottle the whole world if it was throttled.
2029 if (bufsize
< SSH_MAX_BACKLOG
)
2030 ssh_throttle_all(ssh
, 0, bufsize
);
2034 * Connect to specified host and port.
2035 * Returns an error message, or NULL on success.
2036 * Also places the canonical host name into `realhost'. It must be
2037 * freed by the caller.
2039 static char *connect_to_host(Ssh ssh
, char *host
, int port
,
2040 char **realhost
, int nodelay
)
2042 static const struct plug_function_table fn_table
= {
2052 ssh
->savedhost
= smalloc(1 + strlen(host
));
2053 if (!ssh
->savedhost
)
2054 fatalbox("Out of memory");
2055 strcpy(ssh
->savedhost
, host
);
2058 port
= 22; /* default ssh port */
2059 ssh
->savedport
= port
;
2064 logeventf(ssh
, "Looking up host \"%s\"", host
);
2065 addr
= name_lookup(host
, port
, realhost
);
2066 if ((err
= sk_addr_error(addr
)))
2074 sk_getaddr(addr
, addrbuf
, 100);
2075 logeventf(ssh
, "Connecting to %s port %d", addrbuf
, port
);
2077 ssh
->fn
= &fn_table
;
2078 ssh
->s
= new_connection(addr
, *realhost
, port
, 0, 1, nodelay
, (Plug
) ssh
);
2079 if ((err
= sk_socket_error(ssh
->s
))) {
2088 * Throttle or unthrottle the SSH connection.
2090 static void ssh1_throttle(Ssh ssh
, int adjust
)
2092 int old_count
= ssh
->v1_throttle_count
;
2093 ssh
->v1_throttle_count
+= adjust
;
2094 assert(ssh
->v1_throttle_count
>= 0);
2095 if (ssh
->v1_throttle_count
&& !old_count
) {
2096 sk_set_frozen(ssh
->s
, 1);
2097 } else if (!ssh
->v1_throttle_count
&& old_count
) {
2098 sk_set_frozen(ssh
->s
, 0);
2103 * Throttle or unthrottle _all_ local data streams (for when sends
2104 * on the SSH connection itself back up).
2106 static void ssh_throttle_all(Ssh ssh
, int enable
, int bufsize
)
2109 struct ssh_channel
*c
;
2111 if (enable
== ssh
->throttled_all
)
2113 ssh
->throttled_all
= enable
;
2114 ssh
->overall_bufsize
= bufsize
;
2117 for (i
= 0; NULL
!= (c
= index234(ssh
->channels
, i
)); i
++) {
2119 case CHAN_MAINSESSION
:
2121 * This is treated separately, outside the switch.
2125 x11_override_throttle(c
->u
.x11
.s
, enable
);
2128 /* Agent channels require no buffer management. */
2131 pfd_override_throttle(c
->u
.x11
.s
, enable
);
2138 * Username and password input, abstracted off into routines
2139 * reusable in several places - even between SSH1 and SSH2.
2142 /* Set up a username or password input loop on a given buffer. */
2143 void setup_userpass_input(Ssh ssh
, char *buffer
, int buflen
, int echo
)
2145 ssh
->userpass_input_buffer
= buffer
;
2146 ssh
->userpass_input_buflen
= buflen
;
2147 ssh
->userpass_input_bufpos
= 0;
2148 ssh
->userpass_input_echo
= echo
;
2152 * Process some terminal data in the course of username/password
2153 * input. Returns >0 for success (line of input returned in
2154 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2155 * for inconclusive (keep waiting for more input please).
2157 int process_userpass_input(Ssh ssh
, unsigned char *in
, int inlen
)
2162 switch (c
= *in
++) {
2165 ssh
->userpass_input_buffer
[ssh
->userpass_input_bufpos
] = 0;
2166 ssh
->userpass_input_buffer
[ssh
->userpass_input_buflen
-1] = 0;
2171 if (ssh
->userpass_input_bufpos
> 0) {
2172 if (ssh
->userpass_input_echo
)
2173 c_write_str(ssh
, "\b \b");
2174 ssh
->userpass_input_bufpos
--;
2179 while (ssh
->userpass_input_bufpos
> 0) {
2180 if (ssh
->userpass_input_echo
)
2181 c_write_str(ssh
, "\b \b");
2182 ssh
->userpass_input_bufpos
--;
2190 if (((c
>= ' ' && c
<= '~') ||
2191 ((unsigned char) c
>= 160))
2192 && ssh
->userpass_input_bufpos
< ssh
->userpass_input_buflen
-1) {
2193 ssh
->userpass_input_buffer
[ssh
->userpass_input_bufpos
++] = c
;
2194 if (ssh
->userpass_input_echo
)
2195 c_write(ssh
, &c
, 1);
2204 * Handle the key exchange and user authentication phases.
2206 static int do_ssh1_login(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
2209 unsigned char cookie
[8];
2210 struct RSAKey servkey
, hostkey
;
2211 struct MD5Context md5c
;
2212 struct do_ssh1_login_state
{
2214 unsigned char *rsabuf
, *keystr1
, *keystr2
;
2215 unsigned long supported_ciphers_mask
, supported_auths_mask
;
2216 int tried_publickey
, tried_agent
;
2217 int tis_auth_refused
, ccard_auth_refused
;
2218 unsigned char session_id
[16];
2221 void *publickey_blob
;
2222 int publickey_bloblen
;
2228 unsigned char request
[5], *response
, *p
;
2237 crState(do_ssh1_login_state
);
2239 crBegin(ssh
->do_ssh1_login_crstate
);
2244 if (ssh
->pktin
.type
!= SSH1_SMSG_PUBLIC_KEY
) {
2245 bombout((ssh
,"Public key packet not received"));
2249 logevent("Received public keys");
2251 memcpy(cookie
, ssh
->pktin
.body
, 8);
2253 i
= makekey(ssh
->pktin
.body
+ 8, &servkey
, &s
->keystr1
, 0);
2254 j
= makekey(ssh
->pktin
.body
+ 8 + i
, &hostkey
, &s
->keystr2
, 0);
2257 * Log the host key fingerprint.
2261 logevent("Host key fingerprint is:");
2262 strcpy(logmsg
, " ");
2263 hostkey
.comment
= NULL
;
2264 rsa_fingerprint(logmsg
+ strlen(logmsg
),
2265 sizeof(logmsg
) - strlen(logmsg
), &hostkey
);
2269 ssh
->v1_remote_protoflags
= GET_32BIT(ssh
->pktin
.body
+ 8 + i
+ j
);
2270 s
->supported_ciphers_mask
= GET_32BIT(ssh
->pktin
.body
+ 12 + i
+ j
);
2271 s
->supported_auths_mask
= GET_32BIT(ssh
->pktin
.body
+ 16 + i
+ j
);
2273 ssh
->v1_local_protoflags
=
2274 ssh
->v1_remote_protoflags
& SSH1_PROTOFLAGS_SUPPORTED
;
2275 ssh
->v1_local_protoflags
|= SSH1_PROTOFLAG_SCREEN_NUMBER
;
2278 MD5Update(&md5c
, s
->keystr2
, hostkey
.bytes
);
2279 MD5Update(&md5c
, s
->keystr1
, servkey
.bytes
);
2280 MD5Update(&md5c
, ssh
->pktin
.body
, 8);
2281 MD5Final(s
->session_id
, &md5c
);
2283 for (i
= 0; i
< 32; i
++)
2284 ssh
->session_key
[i
] = random_byte();
2286 s
->len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
2288 s
->rsabuf
= smalloc(s
->len
);
2290 fatalbox("Out of memory");
2293 * Verify the host key.
2297 * First format the key into a string.
2299 int len
= rsastr_len(&hostkey
);
2300 char fingerprint
[100];
2301 char *keystr
= smalloc(len
);
2303 fatalbox("Out of memory");
2304 rsastr_fmt(keystr
, &hostkey
);
2305 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
2306 verify_ssh_host_key(ssh
->frontend
,
2307 ssh
->savedhost
, ssh
->savedport
, "rsa", keystr
,
2312 for (i
= 0; i
< 32; i
++) {
2313 s
->rsabuf
[i
] = ssh
->session_key
[i
];
2315 s
->rsabuf
[i
] ^= s
->session_id
[i
];
2318 if (hostkey
.bytes
> servkey
.bytes
) {
2319 rsaencrypt(s
->rsabuf
, 32, &servkey
);
2320 rsaencrypt(s
->rsabuf
, servkey
.bytes
, &hostkey
);
2322 rsaencrypt(s
->rsabuf
, 32, &hostkey
);
2323 rsaencrypt(s
->rsabuf
, hostkey
.bytes
, &servkey
);
2326 logevent("Encrypted session key");
2329 int cipher_chosen
= 0, warn
= 0;
2330 char *cipher_string
= NULL
;
2332 for (i
= 0; !cipher_chosen
&& i
< CIPHER_MAX
; i
++) {
2333 int next_cipher
= cfg
.ssh_cipherlist
[i
];
2334 if (next_cipher
== CIPHER_WARN
) {
2335 /* If/when we choose a cipher, warn about it */
2337 } else if (next_cipher
== CIPHER_AES
) {
2338 /* XXX Probably don't need to mention this. */
2339 logevent("AES not supported in SSH1, skipping");
2341 switch (next_cipher
) {
2342 case CIPHER_3DES
: s
->cipher_type
= SSH_CIPHER_3DES
;
2343 cipher_string
= "3DES"; break;
2344 case CIPHER_BLOWFISH
: s
->cipher_type
= SSH_CIPHER_BLOWFISH
;
2345 cipher_string
= "Blowfish"; break;
2346 case CIPHER_DES
: s
->cipher_type
= SSH_CIPHER_DES
;
2347 cipher_string
= "single-DES"; break;
2349 if (s
->supported_ciphers_mask
& (1 << s
->cipher_type
))
2353 if (!cipher_chosen
) {
2354 if ((s
->supported_ciphers_mask
& (1 << SSH_CIPHER_3DES
)) == 0)
2355 bombout((ssh
,"Server violates SSH 1 protocol by not "
2356 "supporting 3DES encryption"));
2358 /* shouldn't happen */
2359 bombout((ssh
,"No supported ciphers found"));
2363 /* Warn about chosen cipher if necessary. */
2365 askcipher(ssh
->frontend
, cipher_string
, 0);
2368 switch (s
->cipher_type
) {
2369 case SSH_CIPHER_3DES
:
2370 logevent("Using 3DES encryption");
2372 case SSH_CIPHER_DES
:
2373 logevent("Using single-DES encryption");
2375 case SSH_CIPHER_BLOWFISH
:
2376 logevent("Using Blowfish encryption");
2380 send_packet(ssh
, SSH1_CMSG_SESSION_KEY
,
2381 PKT_CHAR
, s
->cipher_type
,
2382 PKT_DATA
, cookie
, 8,
2383 PKT_CHAR
, (s
->len
* 8) >> 8, PKT_CHAR
, (s
->len
* 8) & 0xFF,
2384 PKT_DATA
, s
->rsabuf
, s
->len
,
2385 PKT_INT
, ssh
->v1_local_protoflags
, PKT_END
);
2387 logevent("Trying to enable encryption...");
2391 ssh
->cipher
= (s
->cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
2392 s
->cipher_type
== SSH_CIPHER_DES ?
&ssh_des
:
2394 ssh
->v1_cipher_ctx
= ssh
->cipher
->make_context();
2395 ssh
->cipher
->sesskey(ssh
->v1_cipher_ctx
, ssh
->session_key
);
2396 logeventf(ssh
, "Initialised %s encryption", ssh
->cipher
->text_name
);
2398 ssh
->crcda_ctx
= crcda_make_context();
2399 logevent("Installing CRC compensation attack detector");
2403 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2404 bombout((ssh
,"Encryption not successfully enabled"));
2408 logevent("Successfully started encryption");
2412 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
2413 if (ssh_get_line
&& !ssh_getline_pw_only
) {
2414 if (!ssh_get_line("login as: ",
2415 s
->username
, sizeof(s
->username
), FALSE
)) {
2417 * get_line failed to get a username.
2420 logevent("No username provided. Abandoning session.");
2421 ssh
->state
= SSH_STATE_CLOSED
;
2425 int ret
; /* need not be kept over crReturn */
2426 c_write_str(ssh
, "login as: ");
2429 setup_userpass_input(ssh
, s
->username
, sizeof(s
->username
), 1);
2431 crWaitUntil(!ispkt
);
2432 ret
= process_userpass_input(ssh
, in
, inlen
);
2436 c_write_str(ssh
, "\r\n");
2439 strncpy(s
->username
, cfg
.username
, sizeof(s
->username
));
2440 s
->username
[sizeof(s
->username
)-1] = '\0';
2443 send_packet(ssh
, SSH1_CMSG_USER
, PKT_STR
, s
->username
, PKT_END
);
2445 char userlog
[22 + sizeof(s
->username
)];
2446 sprintf(userlog
, "Sent username \"%s\"", s
->username
);
2448 if (flags
& FLAG_INTERACTIVE
&&
2449 (!((flags
& FLAG_STDERR
) && (flags
& FLAG_VERBOSE
)))) {
2450 strcat(userlog
, "\r\n");
2451 c_write_str(ssh
, userlog
);
2458 if ((ssh
->remote_bugs
& BUG_CHOKES_ON_RSA
)) {
2459 /* We must not attempt PK auth. Pretend we've already tried it. */
2460 s
->tried_publickey
= s
->tried_agent
= 1;
2462 s
->tried_publickey
= s
->tried_agent
= 0;
2464 s
->tis_auth_refused
= s
->ccard_auth_refused
= 0;
2465 /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
2467 if (!rsakey_pubblob(cfg
.keyfile
,
2468 &s
->publickey_blob
, &s
->publickey_bloblen
))
2469 s
->publickey_blob
= NULL
;
2471 s
->publickey_blob
= NULL
;
2473 while (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2474 s
->pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
2476 if (agent_exists() && !s
->tried_agent
) {
2478 * Attempt RSA authentication using Pageant.
2484 logevent("Pageant is running. Requesting keys.");
2486 /* Request the keys held by the agent. */
2487 PUT_32BIT(s
->request
, 1);
2488 s
->request
[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES
;
2489 agent_query(s
->request
, 5, &r
, &s
->responselen
);
2490 s
->response
= (unsigned char *) r
;
2491 if (s
->response
&& s
->responselen
>= 5 &&
2492 s
->response
[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER
) {
2493 s
->p
= s
->response
+ 5;
2494 s
->nkeys
= GET_32BIT(s
->p
);
2498 sprintf(buf
, "Pageant has %d SSH1 keys", s
->nkeys
);
2501 for (s
->keyi
= 0; s
->keyi
< s
->nkeys
; s
->keyi
++) {
2504 sprintf(buf
, "Trying Pageant key #%d", s
->keyi
);
2507 if (s
->publickey_blob
&&
2508 !memcmp(s
->p
, s
->publickey_blob
,
2509 s
->publickey_bloblen
)) {
2510 logevent("This key matches configured key file");
2511 s
->tried_publickey
= 1;
2514 s
->p
+= ssh1_read_bignum(s
->p
, &s
->key
.exponent
);
2515 s
->p
+= ssh1_read_bignum(s
->p
, &s
->key
.modulus
);
2516 s
->commentlen
= GET_32BIT(s
->p
);
2519 s
->p
+= s
->commentlen
;
2520 send_packet(ssh
, SSH1_CMSG_AUTH_RSA
,
2521 PKT_BIGNUM
, s
->key
.modulus
, PKT_END
);
2523 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2524 logevent("Key refused");
2527 logevent("Received RSA challenge");
2528 ssh1_read_bignum(ssh
->pktin
.body
, &s
->challenge
);
2530 char *agentreq
, *q
, *ret
;
2533 len
= 1 + 4; /* message type, bit count */
2534 len
+= ssh1_bignum_length(s
->key
.exponent
);
2535 len
+= ssh1_bignum_length(s
->key
.modulus
);
2536 len
+= ssh1_bignum_length(s
->challenge
);
2537 len
+= 16; /* session id */
2538 len
+= 4; /* response format */
2539 agentreq
= smalloc(4 + len
);
2540 PUT_32BIT(agentreq
, len
);
2542 *q
++ = SSH1_AGENTC_RSA_CHALLENGE
;
2543 PUT_32BIT(q
, bignum_bitcount(s
->key
.modulus
));
2545 q
+= ssh1_write_bignum(q
, s
->key
.exponent
);
2546 q
+= ssh1_write_bignum(q
, s
->key
.modulus
);
2547 q
+= ssh1_write_bignum(q
, s
->challenge
);
2548 memcpy(q
, s
->session_id
, 16);
2550 PUT_32BIT(q
, 1); /* response format */
2551 agent_query(agentreq
, len
+ 4, &vret
, &retlen
);
2555 if (ret
[4] == SSH1_AGENT_RSA_RESPONSE
) {
2556 logevent("Sending Pageant's response");
2557 send_packet(ssh
, SSH1_CMSG_AUTH_RSA_RESPONSE
,
2558 PKT_DATA
, ret
+ 5, 16,
2562 if (ssh
->pktin
.type
== SSH1_SMSG_SUCCESS
) {
2564 ("Pageant's response accepted");
2565 if (flags
& FLAG_VERBOSE
) {
2566 c_write_str(ssh
, "Authenticated using"
2568 c_write(ssh
, s
->commentp
,
2570 c_write_str(ssh
, "\" from agent\r\n");
2575 ("Pageant's response not accepted");
2578 ("Pageant failed to answer challenge");
2582 logevent("No reply received from Pageant");
2585 freebn(s
->key
.exponent
);
2586 freebn(s
->key
.modulus
);
2587 freebn(s
->challenge
);
2595 if (*cfg
.keyfile
&& !s
->tried_publickey
)
2596 s
->pwpkt_type
= SSH1_CMSG_AUTH_RSA
;
2598 if (cfg
.try_tis_auth
&&
2599 (s
->supported_auths_mask
& (1 << SSH1_AUTH_TIS
)) &&
2600 !s
->tis_auth_refused
) {
2601 s
->pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
2602 logevent("Requested TIS authentication");
2603 send_packet(ssh
, SSH1_CMSG_AUTH_TIS
, PKT_END
);
2605 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
2606 logevent("TIS authentication declined");
2607 if (flags
& FLAG_INTERACTIVE
)
2608 c_write_str(ssh
, "TIS authentication refused.\r\n");
2609 s
->tis_auth_refused
= 1;
2612 int challengelen
= GET_32BIT(ssh
->pktin
.body
);
2613 logevent("Received TIS challenge");
2614 if (challengelen
> sizeof(s
->prompt
) - 1)
2615 challengelen
= sizeof(s
->prompt
) - 1;/* prevent overrun */
2616 memcpy(s
->prompt
, ssh
->pktin
.body
+ 4, challengelen
);
2617 /* Prompt heuristic comes from OpenSSH */
2618 strncpy(s
->prompt
+ challengelen
,
2619 memchr(s
->prompt
, '\n', challengelen
) ?
2620 "": "\r\nResponse: ",
2621 (sizeof s
->prompt
) - challengelen
);
2622 s
->prompt
[(sizeof s
->prompt
) - 1] = '\0';
2625 if (cfg
.try_tis_auth
&&
2626 (s
->supported_auths_mask
& (1 << SSH1_AUTH_CCARD
)) &&
2627 !s
->ccard_auth_refused
) {
2628 s
->pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
2629 logevent("Requested CryptoCard authentication");
2630 send_packet(ssh
, SSH1_CMSG_AUTH_CCARD
, PKT_END
);
2632 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
2633 logevent("CryptoCard authentication declined");
2634 c_write_str(ssh
, "CryptoCard authentication refused.\r\n");
2635 s
->ccard_auth_refused
= 1;
2638 int challengelen
= GET_32BIT(ssh
->pktin
.body
);
2639 logevent("Received CryptoCard challenge");
2640 if (challengelen
> sizeof(s
->prompt
) - 1)
2641 challengelen
= sizeof(s
->prompt
) - 1;/* prevent overrun */
2642 memcpy(s
->prompt
, ssh
->pktin
.body
+ 4, challengelen
);
2643 strncpy(s
->prompt
+ challengelen
,
2644 memchr(s
->prompt
, '\n', challengelen
) ?
2645 "" : "\r\nResponse: ",
2646 sizeof(s
->prompt
) - challengelen
);
2647 s
->prompt
[sizeof(s
->prompt
) - 1] = '\0';
2650 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2651 sprintf(s
->prompt
, "%.90s@%.90s's password: ",
2652 s
->username
, ssh
->savedhost
);
2654 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2655 char *comment
= NULL
;
2658 if (flags
& FLAG_VERBOSE
)
2659 c_write_str(ssh
, "Trying public key authentication.\r\n");
2660 logeventf(ssh
, "Trying public key \"%s\"", cfg
.keyfile
);
2661 type
= key_type(cfg
.keyfile
);
2662 if (type
!= SSH_KEYTYPE_SSH1
) {
2663 sprintf(msgbuf
, "Key is of wrong type (%s)",
2664 key_type_to_str(type
));
2666 c_write_str(ssh
, msgbuf
);
2667 c_write_str(ssh
, "\r\n");
2668 s
->tried_publickey
= 1;
2671 if (!rsakey_encrypted(cfg
.keyfile
, &comment
)) {
2672 if (flags
& FLAG_VERBOSE
)
2673 c_write_str(ssh
, "No passphrase required.\r\n");
2676 sprintf(s
->prompt
, "Passphrase for key \"%.100s\": ", comment
);
2681 * Show password prompt, having first obtained it via a TIS
2682 * or CryptoCard exchange if we're doing TIS or CryptoCard
2686 if (!ssh_get_line(s
->prompt
, s
->password
,
2687 sizeof(s
->password
), TRUE
)) {
2689 * get_line failed to get a password (for example
2690 * because one was supplied on the command line
2691 * which has already failed to work). Terminate.
2693 send_packet(ssh
, SSH1_MSG_DISCONNECT
,
2694 PKT_STR
, "No more passwords available to try",
2696 logevent("Unable to authenticate");
2697 connection_fatal(ssh
->frontend
, "Unable to authenticate");
2698 ssh
->state
= SSH_STATE_CLOSED
;
2702 /* Prompt may have come from server. We've munged it a bit, so
2703 * we know it to be zero-terminated at least once. */
2704 int ret
; /* need not be saved over crReturn */
2705 c_write_untrusted(ssh
, s
->prompt
, strlen(s
->prompt
));
2708 setup_userpass_input(ssh
, s
->password
, sizeof(s
->password
), 0);
2710 crWaitUntil(!ispkt
);
2711 ret
= process_userpass_input(ssh
, in
, inlen
);
2715 c_write_str(ssh
, "\r\n");
2719 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2721 * Try public key authentication with the specified
2724 s
->tried_publickey
= 1;
2727 int ret
= loadrsakey(cfg
.keyfile
, &s
->key
, s
->password
);
2729 c_write_str(ssh
, "Couldn't load private key from ");
2730 c_write_str(ssh
, cfg
.keyfile
);
2731 c_write_str(ssh
, ".\r\n");
2732 continue; /* go and try password */
2735 c_write_str(ssh
, "Wrong passphrase.\r\n");
2736 s
->tried_publickey
= 0;
2737 continue; /* try again */
2742 * Send a public key attempt.
2744 send_packet(ssh
, SSH1_CMSG_AUTH_RSA
,
2745 PKT_BIGNUM
, s
->key
.modulus
, PKT_END
);
2748 if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2749 c_write_str(ssh
, "Server refused our public key.\r\n");
2750 continue; /* go and try password */
2752 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2753 bombout((ssh
,"Bizarre response to offer of public key"));
2759 unsigned char buffer
[32];
2760 Bignum challenge
, response
;
2762 ssh1_read_bignum(ssh
->pktin
.body
, &challenge
);
2763 response
= rsadecrypt(challenge
, &s
->key
);
2764 freebn(s
->key
.private_exponent
);/* burn the evidence */
2766 for (i
= 0; i
< 32; i
++) {
2767 buffer
[i
] = bignum_byte(response
, 31 - i
);
2771 MD5Update(&md5c
, buffer
, 32);
2772 MD5Update(&md5c
, s
->session_id
, 16);
2773 MD5Final(buffer
, &md5c
);
2775 send_packet(ssh
, SSH1_CMSG_AUTH_RSA_RESPONSE
,
2776 PKT_DATA
, buffer
, 16, PKT_END
);
2783 if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2784 if (flags
& FLAG_VERBOSE
)
2785 c_write_str(ssh
, "Failed to authenticate with"
2786 " our public key.\r\n");
2787 continue; /* go and try password */
2788 } else if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2789 bombout((ssh
,"Bizarre response to RSA authentication response"));
2793 break; /* we're through! */
2795 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2797 * Defence against traffic analysis: we send a
2798 * whole bunch of packets containing strings of
2799 * different lengths. One of these strings is the
2800 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2801 * The others are all random data in
2802 * SSH1_MSG_IGNORE packets. This way a passive
2803 * listener can't tell which is the password, and
2804 * hence can't deduce the password length.
2806 * Anybody with a password length greater than 16
2807 * bytes is going to have enough entropy in their
2808 * password that a listener won't find it _that_
2809 * much help to know how long it is. So what we'll
2812 * - if password length < 16, we send 15 packets
2813 * containing string lengths 1 through 15
2815 * - otherwise, we let N be the nearest multiple
2816 * of 8 below the password length, and send 8
2817 * packets containing string lengths N through
2818 * N+7. This won't obscure the order of
2819 * magnitude of the password length, but it will
2820 * introduce a bit of extra uncertainty.
2822 * A few servers (the old 1.2.18 through 1.2.22)
2823 * can't deal with SSH1_MSG_IGNORE. For these
2824 * servers, we need an alternative defence. We make
2825 * use of the fact that the password is interpreted
2826 * as a C string: so we can append a NUL, then some
2829 * One server (a Cisco one) can deal with neither
2830 * SSH1_MSG_IGNORE _nor_ a padded password string.
2831 * For this server we are left with no defences
2832 * against password length sniffing.
2834 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
)) {
2836 * The server can deal with SSH1_MSG_IGNORE, so
2837 * we can use the primary defence.
2839 int bottom
, top
, pwlen
, i
;
2842 pwlen
= strlen(s
->password
);
2844 bottom
= 0; /* zero length passwords are OK! :-) */
2847 bottom
= pwlen
& ~7;
2851 assert(pwlen
>= bottom
&& pwlen
<= top
);
2853 randomstr
= smalloc(top
+ 1);
2855 for (i
= bottom
; i
<= top
; i
++) {
2857 defer_packet(ssh
, s
->pwpkt_type
,
2858 PKT_STR
, s
->password
, PKT_END
);
2860 for (j
= 0; j
< i
; j
++) {
2862 randomstr
[j
] = random_byte();
2863 } while (randomstr
[j
] == '\0');
2865 randomstr
[i
] = '\0';
2866 defer_packet(ssh
, SSH1_MSG_IGNORE
,
2867 PKT_STR
, randomstr
, PKT_END
);
2870 logevent("Sending password with camouflage packets");
2871 ssh_pkt_defersend(ssh
);
2873 else if (!(ssh
->remote_bugs
& BUG_NEEDS_SSH1_PLAIN_PASSWORD
)) {
2875 * The server can't deal with SSH1_MSG_IGNORE
2876 * but can deal with padded passwords, so we
2877 * can use the secondary defence.
2883 len
= strlen(s
->password
);
2884 if (len
< sizeof(string
)) {
2886 strcpy(string
, s
->password
);
2887 len
++; /* cover the zero byte */
2888 while (len
< sizeof(string
)) {
2889 string
[len
++] = (char) random_byte();
2894 logevent("Sending length-padded password");
2895 send_packet(ssh
, s
->pwpkt_type
, PKT_INT
, len
,
2896 PKT_DATA
, ss
, len
, PKT_END
);
2899 * The server has _both_
2900 * BUG_CHOKES_ON_SSH1_IGNORE and
2901 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2902 * therefore nothing we can do.
2905 len
= strlen(s
->password
);
2906 logevent("Sending unpadded password");
2907 send_packet(ssh
, s
->pwpkt_type
, PKT_INT
, len
,
2908 PKT_DATA
, s
->password
, len
, PKT_END
);
2911 send_packet(ssh
, s
->pwpkt_type
, PKT_STR
, s
->password
, PKT_END
);
2914 logevent("Sent password");
2915 memset(s
->password
, 0, strlen(s
->password
));
2917 if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2918 if (flags
& FLAG_VERBOSE
)
2919 c_write_str(ssh
, "Access denied\r\n");
2920 logevent("Authentication refused");
2921 } else if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2922 bombout((ssh
,"Strange packet received, type %d", ssh
->pktin
.type
));
2927 logevent("Authentication successful");
2932 void sshfwd_close(struct ssh_channel
*c
)
2936 if (c
&& !c
->closes
) {
2938 * If the channel's remoteid is -1, we have sent
2939 * CHANNEL_OPEN for this channel, but it hasn't even been
2940 * acknowledged by the server. So we must set a close flag
2941 * on it now, and then when the server acks the channel
2942 * open, we can close it then.
2944 if (((int)c
->remoteid
) != -1) {
2945 if (ssh
->version
== 1) {
2946 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
2949 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_CLOSE
);
2950 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
2954 c
->closes
= 1; /* sent MSG_CLOSE */
2955 if (c
->type
== CHAN_X11
) {
2957 logevent("Forwarded X11 connection terminated");
2958 } else if (c
->type
== CHAN_SOCKDATA
||
2959 c
->type
== CHAN_SOCKDATA_DORMANT
) {
2961 logevent("Forwarded port closed");
2966 int sshfwd_write(struct ssh_channel
*c
, char *buf
, int len
)
2970 if (ssh
->version
== 1) {
2971 send_packet(ssh
, SSH1_MSG_CHANNEL_DATA
,
2972 PKT_INT
, c
->remoteid
,
2973 PKT_INT
, len
, PKT_DATA
, buf
, len
, PKT_END
);
2975 * In SSH1 we can return 0 here - implying that forwarded
2976 * connections are never individually throttled - because
2977 * the only circumstance that can cause throttling will be
2978 * the whole SSH connection backing up, in which case
2979 * _everything_ will be throttled as a whole.
2983 ssh2_add_channel_data(c
, buf
, len
);
2984 return ssh2_try_send(c
);
2988 void sshfwd_unthrottle(struct ssh_channel
*c
, int bufsize
)
2992 if (ssh
->version
== 1) {
2993 if (c
->v
.v1
.throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
2994 c
->v
.v1
.throttling
= 0;
2995 ssh1_throttle(ssh
, -1);
2998 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
3002 static void ssh1_protocol(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
3004 crBegin(ssh
->ssh1_protocol_crstate
);
3008 while (!do_ssh1_login(ssh
, in
, inlen
, ispkt
)) {
3011 if (ssh
->state
== SSH_STATE_CLOSED
)
3014 if (cfg
.agentfwd
&& agent_exists()) {
3015 logevent("Requesting agent forwarding");
3016 send_packet(ssh
, SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
3020 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3021 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3022 bombout((ssh
,"Protocol confusion"));
3024 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3025 logevent("Agent forwarding refused");
3027 logevent("Agent forwarding enabled");
3028 ssh
->agentfwd_enabled
= TRUE
;
3032 if (cfg
.x11_forward
) {
3033 char proto
[20], data
[64];
3034 logevent("Requesting X11 forwarding");
3035 ssh
->x11auth
= x11_invent_auth(proto
, sizeof(proto
),
3036 data
, sizeof(data
));
3037 if (ssh
->v1_local_protoflags
& SSH1_PROTOFLAG_SCREEN_NUMBER
) {
3038 send_packet(ssh
, SSH1_CMSG_X11_REQUEST_FORWARDING
,
3039 PKT_STR
, proto
, PKT_STR
, data
,
3040 PKT_INT
, 0, PKT_END
);
3042 send_packet(ssh
, SSH1_CMSG_X11_REQUEST_FORWARDING
,
3043 PKT_STR
, proto
, PKT_STR
, data
, PKT_END
);
3048 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3049 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3050 bombout((ssh
,"Protocol confusion"));
3052 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3053 logevent("X11 forwarding refused");
3055 logevent("X11 forwarding enabled");
3056 ssh
->X11_fwd_enabled
= TRUE
;
3063 int sport
,dport
,sserv
,dserv
;
3064 char sports
[256], dports
[256], saddr
[256], host
[256];
3066 ssh
->rportfwds
= newtree234(ssh_rportcmp_ssh1
);
3067 /* Add port forwardings. */
3068 ssh
->portfwd_strptr
= cfg
.portfwd
;
3069 while (*ssh
->portfwd_strptr
) {
3070 type
= *ssh
->portfwd_strptr
++;
3073 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= '\t') {
3074 if (*ssh
->portfwd_strptr
== ':') {
3076 * We've seen a colon in the middle of the
3077 * source port number. This means that
3078 * everything we've seen until now is the
3079 * source _address_, so we'll move it into
3080 * saddr and start sports from the beginning
3083 ssh
->portfwd_strptr
++;
3085 strcpy(saddr
, sports
);
3088 if (n
< 255) sports
[n
++] = *ssh
->portfwd_strptr
++;
3091 if (*ssh
->portfwd_strptr
== '\t')
3092 ssh
->portfwd_strptr
++;
3094 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= ':') {
3095 if (n
< 255) host
[n
++] = *ssh
->portfwd_strptr
++;
3098 if (*ssh
->portfwd_strptr
== ':')
3099 ssh
->portfwd_strptr
++;
3101 while (*ssh
->portfwd_strptr
) {
3102 if (n
< 255) dports
[n
++] = *ssh
->portfwd_strptr
++;
3105 ssh
->portfwd_strptr
++;
3106 dport
= atoi(dports
);
3110 dport
= net_service_lookup(dports
);
3112 logeventf(ssh
, "Service lookup failed for"
3113 " destination port \"%s\"", dports
);
3116 sport
= atoi(sports
);
3120 sport
= net_service_lookup(sports
);
3122 logeventf(ssh
, "Service lookup failed for source"
3123 " port \"%s\"", sports
);
3126 if (sport
&& dport
) {
3128 pfd_addforward(host
, dport
, *saddr ? saddr
: NULL
,
3130 logeventf(ssh
, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3131 " forwarding to %s:%.*s%.*s%d%.*s",
3132 (int)(*saddr?
strlen(saddr
):0), *saddr?saddr
:NULL
,
3133 (int)(*saddr?
1:0), ":",
3134 (int)(sserv ?
strlen(sports
) : 0), sports
,
3135 sserv
, "(", sport
, sserv
, ")",
3137 (int)(dserv ?
strlen(dports
) : 0), dports
,
3138 dserv
, "(", dport
, dserv
, ")");
3140 struct ssh_rportfwd
*pf
;
3141 pf
= smalloc(sizeof(*pf
));
3142 strcpy(pf
->dhost
, host
);
3146 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
3149 if (add234(ssh
->rportfwds
, pf
) != pf
) {
3151 "Duplicate remote port forwarding to %s:%d",
3155 logeventf(ssh
, "Requesting remote port %.*s%.*s%d%.*s"
3156 " forward to %s:%.*s%.*s%d%.*s",
3157 (int)(sserv ?
strlen(sports
) : 0), sports
,
3158 sserv
, "(", sport
, sserv
, ")",
3160 (int)(dserv ?
strlen(dports
) : 0), dports
,
3161 dserv
, "(", dport
, dserv
, ")");
3162 send_packet(ssh
, SSH1_CMSG_PORT_FORWARD_REQUEST
,
3170 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3171 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3172 bombout((ssh
,"Protocol confusion"));
3174 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3175 c_write_str(ssh
, "Server refused port"
3178 logevent("Remote port forwarding enabled");
3186 send_packet(ssh
, SSH1_CMSG_REQUEST_PTY
,
3187 PKT_STR
, cfg
.termtype
,
3188 PKT_INT
, ssh
->term_height
,
3189 PKT_INT
, ssh
->term_width
,
3190 PKT_INT
, 0, PKT_INT
, 0, PKT_CHAR
, 0, PKT_END
);
3191 ssh
->state
= SSH_STATE_INTERMED
;
3195 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3196 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3197 bombout((ssh
,"Protocol confusion"));
3199 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3200 c_write_str(ssh
, "Server refused to allocate pty\r\n");
3201 ssh
->editing
= ssh
->echoing
= 1;
3203 logevent("Allocated pty");
3205 ssh
->editing
= ssh
->echoing
= 1;
3208 if (cfg
.compression
) {
3209 send_packet(ssh
, SSH1_CMSG_REQUEST_COMPRESSION
, PKT_INT
, 6, PKT_END
);
3213 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3214 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3215 bombout((ssh
,"Protocol confusion"));
3217 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3218 c_write_str(ssh
, "Server refused to compress\r\n");
3220 logevent("Started compression");
3221 ssh
->v1_compressing
= TRUE
;
3222 ssh
->cs_comp_ctx
= zlib_compress_init();
3223 logevent("Initialised zlib (RFC1950) compression");
3224 ssh
->sc_comp_ctx
= zlib_decompress_init();
3225 logevent("Initialised zlib (RFC1950) decompression");
3229 * Start the shell or command.
3231 * Special case: if the first-choice command is an SSH2
3232 * subsystem (hence not usable here) and the second choice
3233 * exists, we fall straight back to that.
3236 char *cmd
= cfg
.remote_cmd_ptr
;
3238 if (cfg
.ssh_subsys
&& cfg
.remote_cmd_ptr2
) {
3239 cmd
= cfg
.remote_cmd_ptr2
;
3240 ssh
->fallback_cmd
= TRUE
;
3243 send_packet(ssh
, SSH1_CMSG_EXEC_CMD
, PKT_STR
, cmd
, PKT_END
);
3245 send_packet(ssh
, SSH1_CMSG_EXEC_SHELL
, PKT_END
);
3246 logevent("Started session");
3249 ssh
->state
= SSH_STATE_SESSION
;
3250 if (ssh
->size_needed
)
3251 ssh_size(ssh
, ssh
->term_width
, ssh
->term_height
);
3252 if (ssh
->eof_needed
)
3253 ssh_special(ssh
, TS_EOF
);
3256 ldisc_send(ssh
->ldisc
, NULL
, 0, 0);/* cause ldisc to notice changes */
3258 ssh
->channels
= newtree234(ssh_channelcmp
);
3262 if (ssh
->pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
3263 ssh
->pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
3264 long len
= GET_32BIT(ssh
->pktin
.body
);
3266 from_backend(ssh
->frontend
,
3267 ssh
->pktin
.type
== SSH1_SMSG_STDERR_DATA
,
3268 ssh
->pktin
.body
+ 4, len
);
3269 if (!ssh
->v1_stdout_throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
3270 ssh
->v1_stdout_throttling
= 1;
3271 ssh1_throttle(ssh
, +1);
3273 } else if (ssh
->pktin
.type
== SSH1_MSG_DISCONNECT
) {
3274 ssh
->state
= SSH_STATE_CLOSED
;
3275 logevent("Received disconnect request");
3277 } else if (ssh
->pktin
.type
== SSH1_SMSG_X11_OPEN
) {
3278 /* Remote side is trying to open a channel to talk to our
3279 * X-Server. Give them back a local channel number. */
3280 struct ssh_channel
*c
;
3282 logevent("Received X11 connect request");
3283 /* Refuse if X11 forwarding is disabled. */
3284 if (!ssh
->X11_fwd_enabled
) {
3285 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3286 PKT_INT
, GET_32BIT(ssh
->pktin
.body
), PKT_END
);
3287 logevent("Rejected X11 connect request");
3289 c
= smalloc(sizeof(struct ssh_channel
));
3292 if (x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
,
3293 ssh
->x11auth
) != NULL
) {
3294 logevent("opening X11 forward connection failed");
3296 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3297 PKT_INT
, GET_32BIT(ssh
->pktin
.body
),
3301 ("opening X11 forward connection succeeded");
3302 c
->remoteid
= GET_32BIT(ssh
->pktin
.body
);
3303 c
->localid
= alloc_channel_id(ssh
);
3305 c
->v
.v1
.throttling
= 0;
3306 c
->type
= CHAN_X11
; /* identify channel type */
3307 add234(ssh
->channels
, c
);
3308 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3309 PKT_INT
, c
->remoteid
, PKT_INT
,
3310 c
->localid
, PKT_END
);
3311 logevent("Opened X11 forward channel");
3314 } else if (ssh
->pktin
.type
== SSH1_SMSG_AGENT_OPEN
) {
3315 /* Remote side is trying to open a channel to talk to our
3316 * agent. Give them back a local channel number. */
3317 struct ssh_channel
*c
;
3319 /* Refuse if agent forwarding is disabled. */
3320 if (!ssh
->agentfwd_enabled
) {
3321 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3322 PKT_INT
, GET_32BIT(ssh
->pktin
.body
), PKT_END
);
3324 c
= smalloc(sizeof(struct ssh_channel
));
3326 c
->remoteid
= GET_32BIT(ssh
->pktin
.body
);
3327 c
->localid
= alloc_channel_id(ssh
);
3329 c
->v
.v1
.throttling
= 0;
3330 c
->type
= CHAN_AGENT
; /* identify channel type */
3331 c
->u
.a
.lensofar
= 0;
3332 add234(ssh
->channels
, c
);
3333 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3334 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
3337 } else if (ssh
->pktin
.type
== SSH1_MSG_PORT_OPEN
) {
3338 /* Remote side is trying to open a channel to talk to a
3339 * forwarded port. Give them back a local channel number. */
3340 struct ssh_channel
*c
;
3341 struct ssh_rportfwd pf
;
3343 char host
[256], buf
[1024];
3345 c
= smalloc(sizeof(struct ssh_channel
));
3348 hostsize
= GET_32BIT(ssh
->pktin
.body
+4);
3349 for(h
= host
, p
= ssh
->pktin
.body
+8; hostsize
!= 0; hostsize
--) {
3350 if (h
+1 < host
+sizeof(host
))
3355 port
= GET_32BIT(p
);
3357 strcpy(pf
.dhost
, host
);
3360 if (find234(ssh
->rportfwds
, &pf
, NULL
) == NULL
) {
3361 sprintf(buf
, "Rejected remote port open request for %s:%d",
3364 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3365 PKT_INT
, GET_32BIT(ssh
->pktin
.body
), PKT_END
);
3367 sprintf(buf
, "Received remote port open request for %s:%d",
3370 e
= pfd_newconnect(&c
->u
.pfd
.s
, host
, port
, c
);
3373 sprintf(buf
, "Port open failed: %s", e
);
3376 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3377 PKT_INT
, GET_32BIT(ssh
->pktin
.body
),
3380 c
->remoteid
= GET_32BIT(ssh
->pktin
.body
);
3381 c
->localid
= alloc_channel_id(ssh
);
3383 c
->v
.v1
.throttling
= 0;
3384 c
->type
= CHAN_SOCKDATA
; /* identify channel type */
3385 add234(ssh
->channels
, c
);
3386 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3387 PKT_INT
, c
->remoteid
, PKT_INT
,
3388 c
->localid
, PKT_END
);
3389 logevent("Forwarded port opened successfully");
3393 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
) {
3394 unsigned int remoteid
= GET_32BIT(ssh
->pktin
.body
);
3395 unsigned int localid
= GET_32BIT(ssh
->pktin
.body
+4);
3396 struct ssh_channel
*c
;
3398 c
= find234(ssh
->channels
, &remoteid
, ssh_channelfind
);
3399 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
3400 c
->remoteid
= localid
;
3401 c
->type
= CHAN_SOCKDATA
;
3402 c
->v
.v1
.throttling
= 0;
3403 pfd_confirm(c
->u
.pfd
.s
);
3406 if (c
&& c
->closes
) {
3408 * We have a pending close on this channel,
3409 * which we decided on before the server acked
3410 * the channel open. So now we know the
3411 * remoteid, we can close it again.
3413 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE
,
3414 PKT_INT
, c
->remoteid
, PKT_END
);
3417 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_OPEN_FAILURE
) {
3418 unsigned int remoteid
= GET_32BIT(ssh
->pktin
.body
);
3419 struct ssh_channel
*c
;
3421 c
= find234(ssh
->channels
, &remoteid
, ssh_channelfind
);
3422 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
3423 logevent("Forwarded connection refused by server");
3424 pfd_close(c
->u
.pfd
.s
);
3425 del234(ssh
->channels
, c
);
3429 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE
||
3430 ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
) {
3431 /* Remote side closes a channel. */
3432 unsigned i
= GET_32BIT(ssh
->pktin
.body
);
3433 struct ssh_channel
*c
;
3434 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
3435 if (c
&& ((int)c
->remoteid
) != -1) {
3438 (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
1 : 2);
3440 if ((c
->closes
== 0) && (c
->type
== CHAN_X11
)) {
3441 logevent("Forwarded X11 connection terminated");
3442 assert(c
->u
.x11
.s
!= NULL
);
3443 x11_close(c
->u
.x11
.s
);
3446 if ((c
->closes
== 0) && (c
->type
== CHAN_SOCKDATA
)) {
3447 logevent("Forwarded port closed");
3448 assert(c
->u
.pfd
.s
!= NULL
);
3449 pfd_close(c
->u
.pfd
.s
);
3453 c
->closes
|= (closetype
<< 2); /* seen this message */
3454 if (!(c
->closes
& closetype
)) {
3455 send_packet(ssh
, ssh
->pktin
.type
, PKT_INT
, c
->remoteid
,
3457 c
->closes
|= closetype
; /* sent it too */
3460 if (c
->closes
== 15) {
3461 del234(ssh
->channels
, c
);
3465 bombout((ssh
,"Received CHANNEL_CLOSE%s for %s channel %d\n",
3466 ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
"" :
3467 "_CONFIRMATION", c ?
"half-open" : "nonexistent",
3470 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_DATA
) {
3471 /* Data sent down one of our channels. */
3472 int i
= GET_32BIT(ssh
->pktin
.body
);
3473 int len
= GET_32BIT(ssh
->pktin
.body
+ 4);
3474 unsigned char *p
= ssh
->pktin
.body
+ 8;
3475 struct ssh_channel
*c
;
3476 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
3481 bufsize
= x11_send(c
->u
.x11
.s
, p
, len
);
3484 bufsize
= pfd_send(c
->u
.pfd
.s
, p
, len
);
3487 /* Data for an agent message. Buffer it. */
3489 if (c
->u
.a
.lensofar
< 4) {
3490 int l
= min(4 - c
->u
.a
.lensofar
, len
);
3491 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
,
3495 c
->u
.a
.lensofar
+= l
;
3497 if (c
->u
.a
.lensofar
== 4) {
3499 4 + GET_32BIT(c
->u
.a
.msglen
);
3500 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
3501 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
3503 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
3505 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
3507 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
,
3511 c
->u
.a
.lensofar
+= l
;
3513 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
3514 void *reply
, *sentreply
;
3516 agent_query(c
->u
.a
.message
,
3517 c
->u
.a
.totallen
, &reply
,
3522 /* Fake SSH_AGENT_FAILURE. */
3523 sentreply
= "\0\0\0\1\5";
3526 send_packet(ssh
, SSH1_MSG_CHANNEL_DATA
,
3527 PKT_INT
, c
->remoteid
,
3529 PKT_DATA
, sentreply
, replylen
,
3533 sfree(c
->u
.a
.message
);
3534 c
->u
.a
.lensofar
= 0;
3537 bufsize
= 0; /* agent channels never back up */
3540 if (!c
->v
.v1
.throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
3541 c
->v
.v1
.throttling
= 1;
3542 ssh1_throttle(ssh
, +1);
3545 } else if (ssh
->pktin
.type
== SSH1_SMSG_SUCCESS
) {
3546 /* may be from EXEC_SHELL on some servers */
3547 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3548 /* may be from EXEC_SHELL on some servers
3549 * if no pty is available or in other odd cases. Ignore */
3550 } else if (ssh
->pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
3552 ssh
->exitcode
= GET_32BIT(ssh
->pktin
.body
);
3553 sprintf(buf
, "Server sent command exit status %d",
3556 send_packet(ssh
, SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
3558 * In case `helpful' firewalls or proxies tack
3559 * extra human-readable text on the end of the
3560 * session which we might mistake for another
3561 * encrypted packet, we close the session once
3562 * we've sent EXIT_CONFIRMATION.
3564 ssh
->state
= SSH_STATE_CLOSED
;
3567 bombout((ssh
,"Strange packet received: type %d", ssh
->pktin
.type
));
3572 int len
= min(inlen
, 512);
3573 send_packet(ssh
, SSH1_CMSG_STDIN_DATA
,
3574 PKT_INT
, len
, PKT_DATA
, in
, len
, PKT_END
);
3585 * Utility routine for decoding comma-separated strings in KEXINIT.
3587 static int in_commasep_string(char *needle
, char *haystack
, int haylen
)
3590 if (!needle
|| !haystack
) /* protect against null pointers */
3592 needlen
= strlen(needle
);
3595 * Is it at the start of the string?
3597 if (haylen
>= needlen
&& /* haystack is long enough */
3598 !memcmp(needle
, haystack
, needlen
) && /* initial match */
3599 (haylen
== needlen
|| haystack
[needlen
] == ',')
3600 /* either , or EOS follows */
3604 * If not, search for the next comma and resume after that.
3605 * If no comma found, terminate.
3607 while (haylen
> 0 && *haystack
!= ',')
3608 haylen
--, haystack
++;
3611 haylen
--, haystack
++; /* skip over comma itself */
3616 * SSH2 key creation method.
3618 static void ssh2_mkkey(Ssh ssh
, Bignum K
, char *H
, char *sessid
, char chr
,
3622 /* First 20 bytes. */
3624 if (!(ssh
->remote_bugs
& BUG_SSH2_DERIVEKEY
))
3626 SHA_Bytes(&s
, H
, 20);
3627 SHA_Bytes(&s
, &chr
, 1);
3628 SHA_Bytes(&s
, sessid
, 20);
3629 SHA_Final(&s
, keyspace
);
3630 /* Next 20 bytes. */
3632 if (!(ssh
->remote_bugs
& BUG_SSH2_DERIVEKEY
))
3634 SHA_Bytes(&s
, H
, 20);
3635 SHA_Bytes(&s
, keyspace
, 20);
3636 SHA_Final(&s
, keyspace
+ 20);
3640 * Handle the SSH2 transport layer.
3642 static int do_ssh2_transport(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
3644 struct do_ssh2_transport_state
{
3645 int nbits
, pbits
, warn
;
3646 Bignum p
, g
, e
, f
, K
;
3647 int kex_init_value
, kex_reply_value
;
3648 const struct ssh_mac
**maclist
;
3650 const struct ssh2_cipher
*cscipher_tobe
;
3651 const struct ssh2_cipher
*sccipher_tobe
;
3652 const struct ssh_mac
*csmac_tobe
;
3653 const struct ssh_mac
*scmac_tobe
;
3654 const struct ssh_compress
*cscomp_tobe
;
3655 const struct ssh_compress
*sccomp_tobe
;
3656 char *hostkeydata
, *sigdata
, *keystr
, *fingerprint
;
3657 int hostkeylen
, siglen
;
3658 void *hkey
; /* actual host key */
3659 unsigned char exchange_hash
[20];
3660 int n_preferred_ciphers
;
3661 const struct ssh2_ciphers
*preferred_ciphers
[CIPHER_MAX
];
3662 const struct ssh_compress
*preferred_comp
;
3665 crState(do_ssh2_transport_state
);
3667 crBegin(ssh
->do_ssh2_transport_crstate
);
3669 s
->cscipher_tobe
= s
->sccipher_tobe
= NULL
;
3670 s
->csmac_tobe
= s
->scmac_tobe
= NULL
;
3671 s
->cscomp_tobe
= s
->sccomp_tobe
= NULL
;
3679 * Set up the preferred ciphers. (NULL => warn below here)
3681 s
->n_preferred_ciphers
= 0;
3682 for (i
= 0; i
< CIPHER_MAX
; i
++) {
3683 switch (cfg
.ssh_cipherlist
[i
]) {
3684 case CIPHER_BLOWFISH
:
3685 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_blowfish
;
3688 if (cfg
.ssh2_des_cbc
) {
3689 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_des
;
3693 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_3des
;
3696 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_aes
;
3699 /* Flag for later. Don't bother if it's the last in
3701 if (i
< CIPHER_MAX
- 1) {
3702 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = NULL
;
3710 * Set up preferred compression.
3712 if (cfg
.compression
)
3713 s
->preferred_comp
= &ssh_zlib
;
3715 s
->preferred_comp
= &ssh_comp_none
;
3718 * Be prepared to work around the buggy MAC problem.
3720 if (ssh
->remote_bugs
& BUG_SSH2_HMAC
)
3721 s
->maclist
= buggymacs
, s
->nmacs
= lenof(buggymacs
);
3723 s
->maclist
= macs
, s
->nmacs
= lenof(macs
);
3727 int i
, j
, cipherstr_started
;
3730 * Construct and send our key exchange packet.
3732 ssh2_pkt_init(ssh
, SSH2_MSG_KEXINIT
);
3733 for (i
= 0; i
< 16; i
++)
3734 ssh2_pkt_addbyte(ssh
, (unsigned char) random_byte());
3735 /* List key exchange algorithms. */
3736 ssh2_pkt_addstring_start(ssh
);
3737 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3738 if (kex_algs
[i
] == &ssh_diffiehellman_gex
&&
3739 (ssh
->remote_bugs
& BUG_SSH2_DH_GEX
))
3741 ssh2_pkt_addstring_str(ssh
, kex_algs
[i
]->name
);
3742 if (i
< lenof(kex_algs
) - 1)
3743 ssh2_pkt_addstring_str(ssh
, ",");
3745 /* List server host key algorithms. */
3746 ssh2_pkt_addstring_start(ssh
);
3747 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3748 ssh2_pkt_addstring_str(ssh
, hostkey_algs
[i
]->name
);
3749 if (i
< lenof(hostkey_algs
) - 1)
3750 ssh2_pkt_addstring_str(ssh
, ",");
3752 /* List client->server encryption algorithms. */
3753 ssh2_pkt_addstring_start(ssh
);
3754 cipherstr_started
= 0;
3755 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
3756 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
3757 if (!c
) continue; /* warning flag */
3758 for (j
= 0; j
< c
->nciphers
; j
++) {
3759 if (cipherstr_started
)
3760 ssh2_pkt_addstring_str(ssh
, ",");
3761 ssh2_pkt_addstring_str(ssh
, c
->list
[j
]->name
);
3762 cipherstr_started
= 1;
3765 /* List server->client encryption algorithms. */
3766 ssh2_pkt_addstring_start(ssh
);
3767 cipherstr_started
= 0;
3768 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
3769 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
3770 if (!c
) continue; /* warning flag */
3771 for (j
= 0; j
< c
->nciphers
; j
++) {
3772 if (cipherstr_started
)
3773 ssh2_pkt_addstring_str(ssh
, ",");
3774 ssh2_pkt_addstring_str(ssh
, c
->list
[j
]->name
);
3775 cipherstr_started
= 1;
3778 /* List client->server MAC algorithms. */
3779 ssh2_pkt_addstring_start(ssh
);
3780 for (i
= 0; i
< s
->nmacs
; i
++) {
3781 ssh2_pkt_addstring_str(ssh
, s
->maclist
[i
]->name
);
3782 if (i
< s
->nmacs
- 1)
3783 ssh2_pkt_addstring_str(ssh
, ",");
3785 /* List server->client MAC algorithms. */
3786 ssh2_pkt_addstring_start(ssh
);
3787 for (i
= 0; i
< s
->nmacs
; i
++) {
3788 ssh2_pkt_addstring_str(ssh
, s
->maclist
[i
]->name
);
3789 if (i
< s
->nmacs
- 1)
3790 ssh2_pkt_addstring_str(ssh
, ",");
3792 /* List client->server compression algorithms. */
3793 ssh2_pkt_addstring_start(ssh
);
3794 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3795 const struct ssh_compress
*c
=
3796 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
3797 ssh2_pkt_addstring_str(ssh
, c
->name
);
3798 if (i
< lenof(compressions
))
3799 ssh2_pkt_addstring_str(ssh
, ",");
3801 /* List server->client compression algorithms. */
3802 ssh2_pkt_addstring_start(ssh
);
3803 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3804 const struct ssh_compress
*c
=
3805 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
3806 ssh2_pkt_addstring_str(ssh
, c
->name
);
3807 if (i
< lenof(compressions
))
3808 ssh2_pkt_addstring_str(ssh
, ",");
3810 /* List client->server languages. Empty list. */
3811 ssh2_pkt_addstring_start(ssh
);
3812 /* List server->client languages. Empty list. */
3813 ssh2_pkt_addstring_start(ssh
);
3814 /* First KEX packet does _not_ follow, because we're not that brave. */
3815 ssh2_pkt_addbool(ssh
, FALSE
);
3817 ssh2_pkt_adduint32(ssh
, 0);
3820 ssh
->exhash
= ssh
->exhashbase
;
3821 sha_string(&ssh
->exhash
, ssh
->pktout
.data
+ 5, ssh
->pktout
.length
- 5);
3827 if (ssh
->pktin
.length
> 5)
3828 sha_string(&ssh
->exhash
, ssh
->pktin
.data
+ 5, ssh
->pktin
.length
- 5);
3831 * Now examine the other side's KEXINIT to see what we're up
3838 if (ssh
->pktin
.type
!= SSH2_MSG_KEXINIT
) {
3839 bombout((ssh
,"expected key exchange packet from server"));
3843 ssh
->hostkey
= NULL
;
3844 s
->cscipher_tobe
= NULL
;
3845 s
->sccipher_tobe
= NULL
;
3846 s
->csmac_tobe
= NULL
;
3847 s
->scmac_tobe
= NULL
;
3848 s
->cscomp_tobe
= NULL
;
3849 s
->sccomp_tobe
= NULL
;
3850 ssh
->pktin
.savedpos
+= 16; /* skip garbage cookie */
3851 ssh2_pkt_getstring(ssh
, &str
, &len
); /* key exchange algorithms */
3852 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3853 if (kex_algs
[i
] == &ssh_diffiehellman_gex
&&
3854 (ssh
->remote_bugs
& BUG_SSH2_DH_GEX
))
3856 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
3857 ssh
->kex
= kex_algs
[i
];
3861 ssh2_pkt_getstring(ssh
, &str
, &len
); /* host key algorithms */
3862 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3863 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
3864 ssh
->hostkey
= hostkey_algs
[i
];
3868 ssh2_pkt_getstring(ssh
, &str
, &len
); /* client->server cipher */
3870 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
3871 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
3875 for (j
= 0; j
< c
->nciphers
; j
++) {
3876 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3877 s
->cscipher_tobe
= c
->list
[j
];
3882 if (s
->cscipher_tobe
) {
3884 askcipher(ssh
->frontend
, s
->cscipher_tobe
->name
, 1);
3888 if (!s
->cscipher_tobe
) {
3889 bombout((ssh
,"Couldn't agree a client-to-server cipher (available: %s)",
3890 str ? str
: "(null)"));
3894 ssh2_pkt_getstring(ssh
, &str
, &len
); /* server->client cipher */
3896 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
3897 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
3901 for (j
= 0; j
< c
->nciphers
; j
++) {
3902 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3903 s
->sccipher_tobe
= c
->list
[j
];
3908 if (s
->sccipher_tobe
) {
3910 askcipher(ssh
->frontend
, s
->sccipher_tobe
->name
, 2);
3914 if (!s
->sccipher_tobe
) {
3915 bombout((ssh
,"Couldn't agree a server-to-client cipher (available: %s)",
3916 str ? str
: "(null)"));
3920 ssh2_pkt_getstring(ssh
, &str
, &len
); /* client->server mac */
3921 for (i
= 0; i
< s
->nmacs
; i
++) {
3922 if (in_commasep_string(s
->maclist
[i
]->name
, str
, len
)) {
3923 s
->csmac_tobe
= s
->maclist
[i
];
3927 ssh2_pkt_getstring(ssh
, &str
, &len
); /* server->client mac */
3928 for (i
= 0; i
< s
->nmacs
; i
++) {
3929 if (in_commasep_string(s
->maclist
[i
]->name
, str
, len
)) {
3930 s
->scmac_tobe
= s
->maclist
[i
];
3934 ssh2_pkt_getstring(ssh
, &str
, &len
); /* client->server compression */
3935 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3936 const struct ssh_compress
*c
=
3937 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
3938 if (in_commasep_string(c
->name
, str
, len
)) {
3943 ssh2_pkt_getstring(ssh
, &str
, &len
); /* server->client compression */
3944 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3945 const struct ssh_compress
*c
=
3946 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
3947 if (in_commasep_string(c
->name
, str
, len
)) {
3955 * Work out the number of bits of key we will need from the key
3956 * exchange. We start with the maximum key length of either
3962 csbits
= s
->cscipher_tobe
->keylen
;
3963 scbits
= s
->sccipher_tobe
->keylen
;
3964 s
->nbits
= (csbits
> scbits ? csbits
: scbits
);
3966 /* The keys only have 160-bit entropy, since they're based on
3967 * a SHA-1 hash. So cap the key size at 160 bits. */
3972 * If we're doing Diffie-Hellman group exchange, start by
3973 * requesting a group.
3975 if (ssh
->kex
== &ssh_diffiehellman_gex
) {
3976 logevent("Doing Diffie-Hellman group exchange");
3977 ssh
->pkt_ctx
|= SSH2_PKTCTX_DHGEX
;
3979 * Work out how big a DH group we will need to allow that
3982 s
->pbits
= 512 << ((s
->nbits
- 1) / 64);
3983 ssh2_pkt_init(ssh
, SSH2_MSG_KEX_DH_GEX_REQUEST
);
3984 ssh2_pkt_adduint32(ssh
, s
->pbits
);
3988 if (ssh
->pktin
.type
!= SSH2_MSG_KEX_DH_GEX_GROUP
) {
3989 bombout((ssh
,"expected key exchange group packet from server"));
3992 s
->p
= ssh2_pkt_getmp(ssh
);
3993 s
->g
= ssh2_pkt_getmp(ssh
);
3994 ssh
->kex_ctx
= dh_setup_group(s
->p
, s
->g
);
3995 s
->kex_init_value
= SSH2_MSG_KEX_DH_GEX_INIT
;
3996 s
->kex_reply_value
= SSH2_MSG_KEX_DH_GEX_REPLY
;
3998 ssh
->pkt_ctx
|= SSH2_PKTCTX_DHGROUP1
;
3999 ssh
->kex_ctx
= dh_setup_group1();
4000 s
->kex_init_value
= SSH2_MSG_KEXDH_INIT
;
4001 s
->kex_reply_value
= SSH2_MSG_KEXDH_REPLY
;
4004 logevent("Doing Diffie-Hellman key exchange");
4006 * Now generate and send e for Diffie-Hellman.
4008 s
->e
= dh_create_e(ssh
->kex_ctx
, s
->nbits
* 2);
4009 ssh2_pkt_init(ssh
, s
->kex_init_value
);
4010 ssh2_pkt_addmp(ssh
, s
->e
);
4014 if (ssh
->pktin
.type
!= s
->kex_reply_value
) {
4015 bombout((ssh
,"expected key exchange reply packet from server"));
4018 ssh2_pkt_getstring(ssh
, &s
->hostkeydata
, &s
->hostkeylen
);
4019 s
->f
= ssh2_pkt_getmp(ssh
);
4020 ssh2_pkt_getstring(ssh
, &s
->sigdata
, &s
->siglen
);
4022 s
->K
= dh_find_K(ssh
->kex_ctx
, s
->f
);
4024 sha_string(&ssh
->exhash
, s
->hostkeydata
, s
->hostkeylen
);
4025 if (ssh
->kex
== &ssh_diffiehellman_gex
) {
4026 sha_uint32(&ssh
->exhash
, s
->pbits
);
4027 sha_mpint(&ssh
->exhash
, s
->p
);
4028 sha_mpint(&ssh
->exhash
, s
->g
);
4030 sha_mpint(&ssh
->exhash
, s
->e
);
4031 sha_mpint(&ssh
->exhash
, s
->f
);
4032 sha_mpint(&ssh
->exhash
, s
->K
);
4033 SHA_Final(&ssh
->exhash
, s
->exchange_hash
);
4035 dh_cleanup(ssh
->kex_ctx
);
4038 debug(("Exchange hash is:\n"));
4039 dmemdump(s
->exchange_hash
, 20);
4042 s
->hkey
= ssh
->hostkey
->newkey(s
->hostkeydata
, s
->hostkeylen
);
4044 !ssh
->hostkey
->verifysig(s
->hkey
, s
->sigdata
, s
->siglen
,
4045 s
->exchange_hash
, 20)) {
4046 bombout((ssh
,"Server's host key did not match the signature supplied"));
4051 * Authenticate remote host: verify host key. (We've already
4052 * checked the signature of the exchange hash.)
4054 s
->keystr
= ssh
->hostkey
->fmtkey(s
->hkey
);
4055 s
->fingerprint
= ssh
->hostkey
->fingerprint(s
->hkey
);
4056 verify_ssh_host_key(ssh
->frontend
,
4057 ssh
->savedhost
, ssh
->savedport
, ssh
->hostkey
->keytype
,
4058 s
->keystr
, s
->fingerprint
);
4059 if (s
->first_kex
) { /* don't bother logging this in rekeys */
4060 logevent("Host key fingerprint is:");
4061 logevent(s
->fingerprint
);
4063 sfree(s
->fingerprint
);
4065 ssh
->hostkey
->freekey(s
->hkey
);
4068 * Send SSH2_MSG_NEWKEYS.
4070 ssh2_pkt_init(ssh
, SSH2_MSG_NEWKEYS
);
4074 * Expect SSH2_MSG_NEWKEYS from server.
4077 if (ssh
->pktin
.type
!= SSH2_MSG_NEWKEYS
) {
4078 bombout((ssh
,"expected new-keys packet from server"));
4083 * Create and initialise session keys.
4085 if (ssh
->cs_cipher_ctx
)
4086 ssh
->cscipher
->free_context(ssh
->cs_cipher_ctx
);
4087 ssh
->cscipher
= s
->cscipher_tobe
;
4088 ssh
->cs_cipher_ctx
= ssh
->cscipher
->make_context();
4090 if (ssh
->sc_cipher_ctx
)
4091 ssh
->sccipher
->free_context(ssh
->sc_cipher_ctx
);
4092 ssh
->sccipher
= s
->sccipher_tobe
;
4093 ssh
->sc_cipher_ctx
= ssh
->sccipher
->make_context();
4095 if (ssh
->cs_mac_ctx
)
4096 ssh
->csmac
->free_context(ssh
->cs_mac_ctx
);
4097 ssh
->csmac
= s
->csmac_tobe
;
4098 ssh
->cs_mac_ctx
= ssh
->csmac
->make_context();
4100 if (ssh
->sc_mac_ctx
)
4101 ssh
->scmac
->free_context(ssh
->sc_mac_ctx
);
4102 ssh
->scmac
= s
->scmac_tobe
;
4103 ssh
->sc_mac_ctx
= ssh
->scmac
->make_context();
4105 if (ssh
->cs_comp_ctx
)
4106 ssh
->cscomp
->compress_cleanup(ssh
->cs_comp_ctx
);
4107 ssh
->cscomp
= s
->cscomp_tobe
;
4108 ssh
->cs_comp_ctx
= ssh
->cscomp
->compress_init();
4110 if (ssh
->sc_comp_ctx
)
4111 ssh
->sccomp
->decompress_cleanup(ssh
->sc_comp_ctx
);
4112 ssh
->sccomp
= s
->sccomp_tobe
;
4113 ssh
->sc_comp_ctx
= ssh
->sccomp
->decompress_init();
4116 * Set IVs after keys. Here we use the exchange hash from the
4117 * _first_ key exchange.
4120 unsigned char keyspace
[40];
4122 memcpy(ssh
->v2_session_id
, s
->exchange_hash
,
4123 sizeof(s
->exchange_hash
));
4124 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'C',keyspace
);
4125 ssh
->cscipher
->setkey(ssh
->cs_cipher_ctx
, keyspace
);
4126 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'D',keyspace
);
4127 ssh
->sccipher
->setkey(ssh
->sc_cipher_ctx
, keyspace
);
4128 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'A',keyspace
);
4129 ssh
->cscipher
->setiv(ssh
->cs_cipher_ctx
, keyspace
);
4130 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'B',keyspace
);
4131 ssh
->sccipher
->setiv(ssh
->sc_cipher_ctx
, keyspace
);
4132 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'E',keyspace
);
4133 ssh
->csmac
->setkey(ssh
->cs_mac_ctx
, keyspace
);
4134 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'F',keyspace
);
4135 ssh
->scmac
->setkey(ssh
->sc_mac_ctx
, keyspace
);
4137 logeventf(ssh
, "Initialised %.200s client->server encryption",
4138 ssh
->cscipher
->text_name
);
4139 logeventf(ssh
, "Initialised %.200s server->client encryption",
4140 ssh
->sccipher
->text_name
);
4141 if (ssh
->cscomp
->text_name
)
4142 logeventf(ssh
, "Initialised %s compression",
4143 ssh
->cscomp
->text_name
);
4144 if (ssh
->sccomp
->text_name
)
4145 logeventf(ssh
, "Initialised %s decompression",
4146 ssh
->sccomp
->text_name
);
4149 * If this is the first key exchange phase, we must pass the
4150 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4151 * wants to see it but because it will need time to initialise
4152 * itself before it sees an actual packet. In subsequent key
4153 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4154 * it would only confuse the layer above.
4156 if (!s
->first_kex
) {
4162 * Now we're encrypting. Begin returning 1 to the protocol main
4163 * function so that other things can run on top of the
4164 * transport. If we ever see a KEXINIT, we must go back to the
4167 while (!(ispkt
&& ssh
->pktin
.type
== SSH2_MSG_KEXINIT
)) {
4170 logevent("Server initiated key re-exchange");
4171 goto begin_key_exchange
;
4177 * Add data to an SSH2 channel output buffer.
4179 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
4182 bufchain_add(&c
->v
.v2
.outbuffer
, buf
, len
);
4186 * Attempt to send data on an SSH2 channel.
4188 static int ssh2_try_send(struct ssh_channel
*c
)
4192 while (c
->v
.v2
.remwindow
> 0 && bufchain_size(&c
->v
.v2
.outbuffer
) > 0) {
4195 bufchain_prefix(&c
->v
.v2
.outbuffer
, &data
, &len
);
4196 if ((unsigned)len
> c
->v
.v2
.remwindow
)
4197 len
= c
->v
.v2
.remwindow
;
4198 if ((unsigned)len
> c
->v
.v2
.remmaxpkt
)
4199 len
= c
->v
.v2
.remmaxpkt
;
4200 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_DATA
);
4201 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
4202 ssh2_pkt_addstring_start(ssh
);
4203 ssh2_pkt_addstring_data(ssh
, data
, len
);
4205 bufchain_consume(&c
->v
.v2
.outbuffer
, len
);
4206 c
->v
.v2
.remwindow
-= len
;
4210 * After having sent as much data as we can, return the amount
4213 return bufchain_size(&c
->v
.v2
.outbuffer
);
4217 * Potentially enlarge the window on an SSH2 channel.
4219 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
)
4224 * Never send WINDOW_ADJUST for a channel that the remote side
4225 * already thinks it's closed; there's no point, since it won't
4226 * be sending any more data anyway.
4231 if (newwin
> c
->v
.v2
.locwindow
) {
4232 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4233 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
4234 ssh2_pkt_adduint32(ssh
, newwin
- c
->v
.v2
.locwindow
);
4236 c
->v
.v2
.locwindow
= newwin
;
4241 * Handle the SSH2 userauth and connection layers.
4243 static void do_ssh2_authconn(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
4245 struct do_ssh2_authconn_state
{
4247 AUTH_INVALID
, AUTH_PUBLICKEY_AGENT
, AUTH_PUBLICKEY_FILE
,
4249 AUTH_KEYBOARD_INTERACTIVE
4253 AUTH_TYPE_PUBLICKEY
,
4254 AUTH_TYPE_PUBLICKEY_OFFER_LOUD
,
4255 AUTH_TYPE_PUBLICKEY_OFFER_QUIET
,
4257 AUTH_TYPE_KEYBOARD_INTERACTIVE
,
4258 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4260 int gotit
, need_pw
, can_pubkey
, can_passwd
, can_keyb_inter
;
4261 int tried_pubkey_config
, tried_agent
, tried_keyb_inter
;
4262 int kbd_inter_running
;
4264 int num_prompts
, curr_prompt
, echo
;
4269 void *publickey_blob
;
4270 int publickey_bloblen
;
4271 unsigned char request
[5], *response
, *p
;
4275 char *pkblob
, *alg
, *commentp
;
4276 int pklen
, alglen
, commentlen
;
4277 int siglen
, retlen
, len
;
4278 char *q
, *agentreq
, *ret
;
4281 crState(do_ssh2_authconn_state
);
4283 crBegin(ssh
->do_ssh2_authconn_crstate
);
4286 * Request userauth protocol, and await a response to it.
4288 ssh2_pkt_init(ssh
, SSH2_MSG_SERVICE_REQUEST
);
4289 ssh2_pkt_addstring(ssh
, "ssh-userauth");
4291 crWaitUntilV(ispkt
);
4292 if (ssh
->pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
) {
4293 bombout((ssh
,"Server refused user authentication protocol"));
4298 * We repeat this whole loop, including the username prompt,
4299 * until we manage a successful authentication. If the user
4300 * types the wrong _password_, they can be sent back to the
4301 * beginning to try another username, if this is configured on.
4302 * (If they specify a username in the config, they are never
4303 * asked, even if they do give a wrong password.)
4305 * I think this best serves the needs of
4307 * - the people who have no configuration, no keys, and just
4308 * want to try repeated (username,password) pairs until they
4309 * type both correctly
4311 * - people who have keys and configuration but occasionally
4312 * need to fall back to passwords
4314 * - people with a key held in Pageant, who might not have
4315 * logged in to a particular machine before; so they want to
4316 * type a username, and then _either_ their key will be
4317 * accepted, _or_ they will type a password. If they mistype
4318 * the username they will want to be able to get back and
4321 s
->username
[0] = '\0';
4322 s
->got_username
= FALSE
;
4327 if (s
->got_username
&& !cfg
.change_username
) {
4329 * We got a username last time round this loop, and
4330 * with change_username turned off we don't try to get
4333 } else if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
4334 if (ssh_get_line
&& !ssh_getline_pw_only
) {
4335 if (!ssh_get_line("login as: ",
4336 s
->username
, sizeof(s
->username
), FALSE
)) {
4338 * get_line failed to get a username.
4341 logevent("No username provided. Abandoning session.");
4342 ssh
->state
= SSH_STATE_CLOSED
;
4346 int ret
; /* need not be saved across crReturn */
4347 c_write_str(ssh
, "login as: ");
4349 setup_userpass_input(ssh
, s
->username
, sizeof(s
->username
), 1);
4351 crWaitUntilV(!ispkt
);
4352 ret
= process_userpass_input(ssh
, in
, inlen
);
4356 c_write_str(ssh
, "\r\n");
4358 s
->username
[strcspn(s
->username
, "\n\r")] = '\0';
4361 strncpy(s
->username
, cfg
.username
, sizeof(s
->username
));
4362 s
->username
[sizeof(s
->username
)-1] = '\0';
4363 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
4364 stuff
= dupprintf("Using username \"%s\".\r\n", s
->username
);
4365 c_write_str(ssh
, stuff
);
4369 s
->got_username
= TRUE
;
4372 * Send an authentication request using method "none": (a)
4373 * just in case it succeeds, and (b) so that we know what
4374 * authentication methods we can usefully try next.
4376 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4378 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4379 ssh2_pkt_addstring(ssh
, s
->username
);
4380 ssh2_pkt_addstring(ssh
, "ssh-connection");/* service requested */
4381 ssh2_pkt_addstring(ssh
, "none"); /* method */
4383 s
->type
= AUTH_TYPE_NONE
;
4385 s
->we_are_in
= FALSE
;
4387 s
->tried_pubkey_config
= FALSE
;
4388 s
->tried_agent
= FALSE
;
4389 s
->tried_keyb_inter
= FALSE
;
4390 s
->kbd_inter_running
= FALSE
;
4391 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
4394 logeventf(ssh
, "Reading private key file \"%.150s\"", cfg
.keyfile
);
4395 keytype
= key_type(cfg
.keyfile
);
4396 if (keytype
== SSH_KEYTYPE_SSH2
) {
4398 ssh2_userkey_loadpub(cfg
.keyfile
, NULL
,
4399 &s
->publickey_bloblen
);
4402 logeventf(ssh
, "Unable to use this key file (%s)",
4403 key_type_to_str(keytype
));
4404 msgbuf
= dupprintf("Unable to use key file \"%.150s\""
4405 " (%s)\r\n", cfg
.keyfile
,
4406 key_type_to_str(keytype
));
4407 c_write_str(ssh
, msgbuf
);
4409 s
->publickey_blob
= NULL
;
4412 s
->publickey_blob
= NULL
;
4416 * Wait for the result of the last authentication request.
4419 crWaitUntilV(ispkt
);
4420 while (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_BANNER
) {
4424 * Don't show the banner if we're operating in
4425 * non-verbose non-interactive mode. (It's probably
4426 * a script, which means nobody will read the
4427 * banner _anyway_, and moreover the printing of
4428 * the banner will screw up processing on the
4429 * output of (say) plink.)
4431 if (flags
& (FLAG_VERBOSE
| FLAG_INTERACTIVE
)) {
4432 ssh2_pkt_getstring(ssh
, &banner
, &size
);
4434 c_write_untrusted(ssh
, banner
, size
);
4436 crWaitUntilV(ispkt
);
4438 if (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_SUCCESS
) {
4439 logevent("Access granted");
4440 s
->we_are_in
= TRUE
;
4444 if (s
->kbd_inter_running
&&
4445 ssh
->pktin
.type
== SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4447 * This is either a further set-of-prompts packet
4448 * in keyboard-interactive authentication, or it's
4449 * the same one and we came back here with `gotit'
4450 * set. In the former case, we must reset the
4451 * curr_prompt variable.
4455 } else if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_FAILURE
) {
4456 bombout((ssh
,"Strange packet received during authentication: type %d",
4464 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4465 * we can look at the string in it and know what we can
4466 * helpfully try next.
4468 if (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
) {
4471 ssh2_pkt_getstring(ssh
, &methods
, &methlen
);
4472 s
->kbd_inter_running
= FALSE
;
4473 if (!ssh2_pkt_getbool(ssh
)) {
4475 * We have received an unequivocal Access
4476 * Denied. This can translate to a variety of
4479 * - if we'd just tried "none" authentication,
4480 * it's not worth printing anything at all
4482 * - if we'd just tried a public key _offer_,
4483 * the message should be "Server refused our
4484 * key" (or no message at all if the key
4485 * came from Pageant)
4487 * - if we'd just tried anything else, the
4488 * message really should be "Access denied".
4490 * Additionally, if we'd just tried password
4491 * authentication, we should break out of this
4492 * whole loop so as to go back to the username
4495 if (s
->type
== AUTH_TYPE_NONE
) {
4497 } else if (s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
||
4498 s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_QUIET
) {
4499 if (s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
)
4500 c_write_str(ssh
, "Server refused our key\r\n");
4501 logevent("Server refused public key");
4502 } else if (s
->type
==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
) {
4503 /* server declined keyboard-interactive; ignore */
4505 c_write_str(ssh
, "Access denied\r\n");
4506 logevent("Access denied");
4507 if (s
->type
== AUTH_TYPE_PASSWORD
) {
4508 s
->we_are_in
= FALSE
;
4513 c_write_str(ssh
, "Further authentication required\r\n");
4514 logevent("Further authentication required");
4518 in_commasep_string("publickey", methods
, methlen
);
4520 in_commasep_string("password", methods
, methlen
);
4521 s
->can_keyb_inter
= cfg
.try_ki_auth
&&
4522 in_commasep_string("keyboard-interactive", methods
, methlen
);
4526 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4529 * Most password/passphrase prompts will be
4530 * non-echoing, so we set this to 0 by default.
4531 * Exception is that some keyboard-interactive prompts
4532 * can be echoing, in which case we'll set this to 1.
4536 if (!s
->method
&& s
->can_pubkey
&&
4537 agent_exists() && !s
->tried_agent
) {
4539 * Attempt public-key authentication using Pageant.
4544 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4545 ssh
->pkt_ctx
|= SSH2_PKTCTX_PUBLICKEY
;
4547 s
->tried_agent
= TRUE
;
4549 logevent("Pageant is running. Requesting keys.");
4551 /* Request the keys held by the agent. */
4552 PUT_32BIT(s
->request
, 1);
4553 s
->request
[4] = SSH2_AGENTC_REQUEST_IDENTITIES
;
4554 agent_query(s
->request
, 5, &r
, &s
->responselen
);
4555 s
->response
= (unsigned char *) r
;
4556 if (s
->response
&& s
->responselen
>= 5 &&
4557 s
->response
[4] == SSH2_AGENT_IDENTITIES_ANSWER
) {
4558 s
->p
= s
->response
+ 5;
4559 s
->nkeys
= GET_32BIT(s
->p
);
4563 sprintf(buf
, "Pageant has %d SSH2 keys", s
->nkeys
);
4566 for (s
->keyi
= 0; s
->keyi
< s
->nkeys
; s
->keyi
++) {
4571 sprintf(buf
, "Trying Pageant key #%d", s
->keyi
);
4574 s
->pklen
= GET_32BIT(s
->p
);
4576 if (s
->publickey_blob
&&
4577 s
->pklen
== s
->publickey_bloblen
&&
4578 !memcmp(s
->p
, s
->publickey_blob
,
4579 s
->publickey_bloblen
)) {
4580 logevent("This key matches configured key file");
4581 s
->tried_pubkey_config
= 1;
4585 s
->alglen
= GET_32BIT(s
->pkblob
);
4586 s
->alg
= s
->pkblob
+ 4;
4587 s
->commentlen
= GET_32BIT(s
->p
);
4590 s
->p
+= s
->commentlen
;
4591 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4592 ssh2_pkt_addstring(ssh
, s
->username
);
4593 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4594 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4595 ssh2_pkt_addbool(ssh
, FALSE
); /* no signature included */
4596 ssh2_pkt_addstring_start(ssh
);
4597 ssh2_pkt_addstring_data(ssh
, s
->alg
, s
->alglen
);
4598 ssh2_pkt_addstring_start(ssh
);
4599 ssh2_pkt_addstring_data(ssh
, s
->pkblob
, s
->pklen
);
4602 crWaitUntilV(ispkt
);
4603 if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4604 logevent("Key refused");
4608 if (flags
& FLAG_VERBOSE
) {
4609 c_write_str(ssh
, "Authenticating with "
4611 c_write(ssh
, s
->commentp
, s
->commentlen
);
4612 c_write_str(ssh
, "\" from agent\r\n");
4616 * Server is willing to accept the key.
4617 * Construct a SIGN_REQUEST.
4619 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4620 ssh2_pkt_addstring(ssh
, s
->username
);
4621 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4622 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4623 ssh2_pkt_addbool(ssh
, TRUE
);
4624 ssh2_pkt_addstring_start(ssh
);
4625 ssh2_pkt_addstring_data(ssh
, s
->alg
, s
->alglen
);
4626 ssh2_pkt_addstring_start(ssh
);
4627 ssh2_pkt_addstring_data(ssh
, s
->pkblob
, s
->pklen
);
4629 s
->siglen
= ssh
->pktout
.length
- 5 + 4 + 20;
4630 s
->len
= 1; /* message type */
4631 s
->len
+= 4 + s
->pklen
; /* key blob */
4632 s
->len
+= 4 + s
->siglen
; /* data to sign */
4633 s
->len
+= 4; /* flags */
4634 s
->agentreq
= smalloc(4 + s
->len
);
4635 PUT_32BIT(s
->agentreq
, s
->len
);
4636 s
->q
= s
->agentreq
+ 4;
4637 *s
->q
++ = SSH2_AGENTC_SIGN_REQUEST
;
4638 PUT_32BIT(s
->q
, s
->pklen
);
4640 memcpy(s
->q
, s
->pkblob
, s
->pklen
);
4642 PUT_32BIT(s
->q
, s
->siglen
);
4644 /* Now the data to be signed... */
4645 PUT_32BIT(s
->q
, 20);
4647 memcpy(s
->q
, ssh
->v2_session_id
, 20);
4649 memcpy(s
->q
, ssh
->pktout
.data
+ 5,
4650 ssh
->pktout
.length
- 5);
4651 s
->q
+= ssh
->pktout
.length
- 5;
4652 /* And finally the (zero) flags word. */
4654 agent_query(s
->agentreq
, s
->len
+ 4, &vret
, &s
->retlen
);
4658 if (s
->ret
[4] == SSH2_AGENT_SIGN_RESPONSE
) {
4659 logevent("Sending Pageant's response");
4660 ssh2_add_sigblob(ssh
, s
->pkblob
, s
->pklen
,
4662 GET_32BIT(s
->ret
+ 5));
4668 ("Pageant failed to answer challenge");
4678 if (!s
->method
&& s
->can_pubkey
&& s
->publickey_blob
4679 && !s
->tried_pubkey_config
) {
4680 unsigned char *pub_blob
;
4681 char *algorithm
, *comment
;
4684 s
->tried_pubkey_config
= TRUE
;
4686 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4687 ssh
->pkt_ctx
|= SSH2_PKTCTX_PUBLICKEY
;
4690 * Try the public key supplied in the configuration.
4692 * First, offer the public blob to see if the server is
4693 * willing to accept it.
4695 pub_blob
= ssh2_userkey_loadpub(cfg
.keyfile
, &algorithm
,
4698 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4699 ssh2_pkt_addstring(ssh
, s
->username
);
4700 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4701 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4702 ssh2_pkt_addbool(ssh
, FALSE
); /* no signature included */
4703 ssh2_pkt_addstring(ssh
, algorithm
);
4704 ssh2_pkt_addstring_start(ssh
);
4705 ssh2_pkt_addstring_data(ssh
, pub_blob
, pub_blob_len
);
4707 logevent("Offered public key"); /* FIXME */
4709 crWaitUntilV(ispkt
);
4710 if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4712 s
->type
= AUTH_TYPE_PUBLICKEY_OFFER_LOUD
;
4713 continue; /* key refused; give up on it */
4716 logevent("Offer of public key accepted");
4718 * Actually attempt a serious authentication using
4721 if (ssh2_userkey_encrypted(cfg
.keyfile
, &comment
)) {
4722 sprintf(s
->pwprompt
,
4723 "Passphrase for key \"%.100s\": ",
4729 c_write_str(ssh
, "Authenticating with public key \"");
4730 c_write_str(ssh
, comment
);
4731 c_write_str(ssh
, "\"\r\n");
4732 s
->method
= AUTH_PUBLICKEY_FILE
;
4736 if (!s
->method
&& s
->can_keyb_inter
&& !s
->tried_keyb_inter
) {
4737 s
->method
= AUTH_KEYBOARD_INTERACTIVE
;
4738 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4739 s
->tried_keyb_inter
= TRUE
;
4741 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4742 ssh
->pkt_ctx
|= SSH2_PKTCTX_KBDINTER
;
4744 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4745 ssh2_pkt_addstring(ssh
, s
->username
);
4746 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4747 ssh2_pkt_addstring(ssh
, "keyboard-interactive"); /* method */
4748 ssh2_pkt_addstring(ssh
, ""); /* lang */
4749 ssh2_pkt_addstring(ssh
, "");
4752 crWaitUntilV(ispkt
);
4753 if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4754 if (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
)
4756 logevent("Keyboard-interactive authentication refused");
4757 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
;
4761 s
->kbd_inter_running
= TRUE
;
4765 if (s
->kbd_inter_running
) {
4766 s
->method
= AUTH_KEYBOARD_INTERACTIVE
;
4767 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4768 s
->tried_keyb_inter
= TRUE
;
4770 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4771 ssh
->pkt_ctx
|= SSH2_PKTCTX_KBDINTER
;
4773 if (s
->curr_prompt
== 0) {
4775 * We've got a fresh USERAUTH_INFO_REQUEST.
4776 * Display header data, and start going through
4779 char *name
, *inst
, *lang
;
4780 int name_len
, inst_len
, lang_len
;
4782 ssh2_pkt_getstring(ssh
, &name
, &name_len
);
4783 ssh2_pkt_getstring(ssh
, &inst
, &inst_len
);
4784 ssh2_pkt_getstring(ssh
, &lang
, &lang_len
);
4786 c_write_untrusted(ssh
, name
, name_len
);
4787 c_write_str(ssh
, "\r\n");
4790 c_write_untrusted(ssh
, inst
, inst_len
);
4791 c_write_str(ssh
, "\r\n");
4793 s
->num_prompts
= ssh2_pkt_getuint32(ssh
);
4797 * If there are prompts remaining in the packet,
4798 * display one and get a response.
4800 if (s
->curr_prompt
< s
->num_prompts
) {
4804 ssh2_pkt_getstring(ssh
, &prompt
, &prompt_len
);
4805 if (prompt_len
> 0) {
4806 strncpy(s
->pwprompt
, prompt
, sizeof(s
->pwprompt
));
4807 s
->pwprompt
[prompt_len
< sizeof(s
->pwprompt
) ?
4808 prompt_len
: sizeof(s
->pwprompt
)-1] = '\0';
4811 "<server failed to send prompt>: ");
4813 s
->echo
= ssh2_pkt_getbool(ssh
);
4819 if (!s
->method
&& s
->can_passwd
) {
4820 s
->method
= AUTH_PASSWORD
;
4821 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4822 ssh
->pkt_ctx
|= SSH2_PKTCTX_PASSWORD
;
4823 sprintf(s
->pwprompt
, "%.90s@%.90s's password: ", s
->username
,
4830 if (!ssh_get_line(s
->pwprompt
, s
->password
,
4831 sizeof(s
->password
), TRUE
)) {
4833 * get_line failed to get a password (for
4834 * example because one was supplied on the
4835 * command line which has already failed to
4838 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
4839 ssh2_pkt_adduint32(ssh
,SSH2_DISCONNECT_BY_APPLICATION
);
4840 ssh2_pkt_addstring(ssh
, "No more passwords available"
4842 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
4844 logevent("Unable to authenticate");
4845 connection_fatal(ssh
->frontend
,
4846 "Unable to authenticate");
4847 ssh
->state
= SSH_STATE_CLOSED
;
4851 int ret
; /* need not be saved across crReturn */
4852 c_write_untrusted(ssh
, s
->pwprompt
, strlen(s
->pwprompt
));
4855 setup_userpass_input(ssh
, s
->password
,
4856 sizeof(s
->password
), s
->echo
);
4858 crWaitUntilV(!ispkt
);
4859 ret
= process_userpass_input(ssh
, in
, inlen
);
4863 c_write_str(ssh
, "\r\n");
4867 if (s
->method
== AUTH_PUBLICKEY_FILE
) {
4869 * We have our passphrase. Now try the actual authentication.
4871 struct ssh2_userkey
*key
;
4873 key
= ssh2_load_userkey(cfg
.keyfile
, s
->password
);
4874 if (key
== SSH2_WRONG_PASSPHRASE
|| key
== NULL
) {
4875 if (key
== SSH2_WRONG_PASSPHRASE
) {
4876 c_write_str(ssh
, "Wrong passphrase\r\n");
4877 s
->tried_pubkey_config
= FALSE
;
4879 c_write_str(ssh
, "Unable to load private key\r\n");
4880 s
->tried_pubkey_config
= TRUE
;
4882 /* Send a spurious AUTH_NONE to return to the top. */
4883 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4884 ssh2_pkt_addstring(ssh
, s
->username
);
4885 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4886 ssh2_pkt_addstring(ssh
, "none"); /* method */
4888 s
->type
= AUTH_TYPE_NONE
;
4890 unsigned char *pkblob
, *sigblob
, *sigdata
;
4891 int pkblob_len
, sigblob_len
, sigdata_len
;
4894 * We have loaded the private key and the server
4895 * has announced that it's willing to accept it.
4896 * Hallelujah. Generate a signature and send it.
4898 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4899 ssh2_pkt_addstring(ssh
, s
->username
);
4900 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4901 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4902 ssh2_pkt_addbool(ssh
, TRUE
);
4903 ssh2_pkt_addstring(ssh
, key
->alg
->name
);
4904 pkblob
= key
->alg
->public_blob(key
->data
, &pkblob_len
);
4905 ssh2_pkt_addstring_start(ssh
);
4906 ssh2_pkt_addstring_data(ssh
, pkblob
, pkblob_len
);
4909 * The data to be signed is:
4913 * followed by everything so far placed in the
4916 sigdata_len
= ssh
->pktout
.length
- 5 + 4 + 20;
4917 sigdata
= smalloc(sigdata_len
);
4918 PUT_32BIT(sigdata
, 20);
4919 memcpy(sigdata
+ 4, ssh
->v2_session_id
, 20);
4920 memcpy(sigdata
+ 24, ssh
->pktout
.data
+ 5,
4921 ssh
->pktout
.length
- 5);
4922 sigblob
= key
->alg
->sign(key
->data
, sigdata
,
4923 sigdata_len
, &sigblob_len
);
4924 ssh2_add_sigblob(ssh
, pkblob
, pkblob_len
,
4925 sigblob
, sigblob_len
);
4931 s
->type
= AUTH_TYPE_PUBLICKEY
;
4933 } else if (s
->method
== AUTH_PASSWORD
) {
4935 * We send the password packet lumped tightly together with
4936 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4937 * string long enough to make the total length of the two
4938 * packets constant. This should ensure that a passive
4939 * listener doing traffic analyis can't work out the length
4942 * For this to work, we need an assumption about the
4943 * maximum length of the password packet. I think 256 is
4944 * pretty conservative. Anyone using a password longer than
4945 * that probably doesn't have much to worry about from
4946 * people who find out how long their password is!
4948 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4949 ssh2_pkt_addstring(ssh
, s
->username
);
4950 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4951 ssh2_pkt_addstring(ssh
, "password");
4952 ssh2_pkt_addbool(ssh
, FALSE
);
4953 ssh2_pkt_addstring(ssh
, s
->password
);
4954 ssh2_pkt_defer(ssh
);
4956 * We'll include a string that's an exact multiple of the
4957 * cipher block size. If the cipher is NULL for some
4958 * reason, we don't do this trick at all because we gain
4961 if (ssh
->cscipher
) {
4964 stringlen
= (256 - ssh
->deferred_len
);
4965 stringlen
+= ssh
->cscipher
->blksize
- 1;
4966 stringlen
-= (stringlen
% ssh
->cscipher
->blksize
);
4969 * Temporarily disable actual compression,
4970 * so we can guarantee to get this string
4971 * exactly the length we want it. The
4972 * compression-disabling routine should
4973 * return an integer indicating how many
4974 * bytes we should adjust our string length
4978 ssh
->cscomp
->disable_compression(ssh
->cs_comp_ctx
);
4980 ssh2_pkt_init(ssh
, SSH2_MSG_IGNORE
);
4981 ssh2_pkt_addstring_start(ssh
);
4982 for (i
= 0; i
< stringlen
; i
++) {
4983 char c
= (char) random_byte();
4984 ssh2_pkt_addstring_data(ssh
, &c
, 1);
4986 ssh2_pkt_defer(ssh
);
4988 ssh_pkt_defersend(ssh
);
4989 logevent("Sent password");
4990 s
->type
= AUTH_TYPE_PASSWORD
;
4991 } else if (s
->method
== AUTH_KEYBOARD_INTERACTIVE
) {
4992 if (s
->curr_prompt
== 0) {
4993 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_INFO_RESPONSE
);
4994 ssh2_pkt_adduint32(ssh
, s
->num_prompts
);
4996 if (s
->need_pw
) { /* only add pw if we just got one! */
4997 ssh2_pkt_addstring(ssh
, s
->password
);
4998 memset(s
->password
, 0, sizeof(s
->password
));
5001 if (s
->curr_prompt
>= s
->num_prompts
) {
5005 * If there are prompts remaining, we set
5006 * `gotit' so that we won't attempt to get
5007 * another packet. Then we go back round the
5008 * loop and will end up retrieving another
5009 * prompt out of the existing packet. Funky or
5014 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
5016 c_write_str(ssh
, "No supported authentication methods"
5017 " left to try!\r\n");
5018 logevent("No supported authentications offered."
5020 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
5021 ssh2_pkt_adduint32(ssh
, SSH2_DISCONNECT_BY_APPLICATION
);
5022 ssh2_pkt_addstring(ssh
, "No supported authentication"
5023 " methods available");
5024 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5026 ssh
->state
= SSH_STATE_CLOSED
;
5030 } while (!s
->we_are_in
);
5033 * Now we're authenticated for the connection protocol. The
5034 * connection protocol will automatically have started at this
5035 * point; there's no need to send SERVICE_REQUEST.
5039 * So now create a channel with a session in it.
5041 ssh
->channels
= newtree234(ssh_channelcmp
);
5042 ssh
->mainchan
= smalloc(sizeof(struct ssh_channel
));
5043 ssh
->mainchan
->ssh
= ssh
;
5044 ssh
->mainchan
->localid
= alloc_channel_id(ssh
);
5045 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN
);
5046 ssh2_pkt_addstring(ssh
, "session");
5047 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->localid
);
5048 ssh
->mainchan
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5049 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->v
.v2
.locwindow
);/* our window size */
5050 ssh2_pkt_adduint32(ssh
, 0x4000UL
); /* our max pkt size */
5052 crWaitUntilV(ispkt
);
5053 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
5054 bombout((ssh
,"Server refused to open a session"));
5056 /* FIXME: error data comes back in FAILURE packet */
5058 if (ssh2_pkt_getuint32(ssh
) != ssh
->mainchan
->localid
) {
5059 bombout((ssh
,"Server's channel confirmation cited wrong channel"));
5062 ssh
->mainchan
->remoteid
= ssh2_pkt_getuint32(ssh
);
5063 ssh
->mainchan
->type
= CHAN_MAINSESSION
;
5064 ssh
->mainchan
->closes
= 0;
5065 ssh
->mainchan
->v
.v2
.remwindow
= ssh2_pkt_getuint32(ssh
);
5066 ssh
->mainchan
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32(ssh
);
5067 bufchain_init(&ssh
->mainchan
->v
.v2
.outbuffer
);
5068 add234(ssh
->channels
, ssh
->mainchan
);
5069 logevent("Opened channel for session");
5072 * Potentially enable X11 forwarding.
5074 if (cfg
.x11_forward
) {
5075 char proto
[20], data
[64];
5076 logevent("Requesting X11 forwarding");
5077 ssh
->x11auth
= x11_invent_auth(proto
, sizeof(proto
),
5078 data
, sizeof(data
));
5079 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5080 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
5081 ssh2_pkt_addstring(ssh
, "x11-req");
5082 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5083 ssh2_pkt_addbool(ssh
, 0); /* many connections */
5084 ssh2_pkt_addstring(ssh
, proto
);
5085 ssh2_pkt_addstring(ssh
, data
);
5086 ssh2_pkt_adduint32(ssh
, 0); /* screen number */
5090 crWaitUntilV(ispkt
);
5091 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5092 unsigned i
= ssh2_pkt_getuint32(ssh
);
5093 struct ssh_channel
*c
;
5094 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5096 continue; /* nonexistent channel */
5097 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5099 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5101 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5102 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5103 bombout((ssh
,"Unexpected response to X11 forwarding request:"
5104 " packet type %d", ssh
->pktin
.type
));
5107 logevent("X11 forwarding refused");
5109 logevent("X11 forwarding enabled");
5110 ssh
->X11_fwd_enabled
= TRUE
;
5115 * Enable port forwardings.
5120 int sport
,dport
,sserv
,dserv
;
5121 char sports
[256], dports
[256], saddr
[256], host
[256];
5123 ssh
->rportfwds
= newtree234(ssh_rportcmp_ssh2
);
5124 /* Add port forwardings. */
5125 ssh
->portfwd_strptr
= cfg
.portfwd
;
5126 while (*ssh
->portfwd_strptr
) {
5127 type
= *ssh
->portfwd_strptr
++;
5130 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= '\t') {
5131 if (*ssh
->portfwd_strptr
== ':') {
5133 * We've seen a colon in the middle of the
5134 * source port number. This means that
5135 * everything we've seen until now is the
5136 * source _address_, so we'll move it into
5137 * saddr and start sports from the beginning
5140 ssh
->portfwd_strptr
++;
5142 strcpy(saddr
, sports
);
5145 if (n
< 255) sports
[n
++] = *ssh
->portfwd_strptr
++;
5148 if (*ssh
->portfwd_strptr
== '\t')
5149 ssh
->portfwd_strptr
++;
5151 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= ':') {
5152 if (n
< 255) host
[n
++] = *ssh
->portfwd_strptr
++;
5155 if (*ssh
->portfwd_strptr
== ':')
5156 ssh
->portfwd_strptr
++;
5158 while (*ssh
->portfwd_strptr
) {
5159 if (n
< 255) dports
[n
++] = *ssh
->portfwd_strptr
++;
5162 ssh
->portfwd_strptr
++;
5163 dport
= atoi(dports
);
5167 dport
= net_service_lookup(dports
);
5169 logeventf(ssh
, "Service lookup failed for destination"
5170 " port \"%s\"", dports
);
5173 sport
= atoi(sports
);
5177 sport
= net_service_lookup(sports
);
5179 logeventf(ssh
, "Service lookup failed for source"
5180 " port \"%s\"", sports
);
5183 if (sport
&& dport
) {
5185 pfd_addforward(host
, dport
, *saddr ? saddr
: NULL
,
5187 logeventf(ssh
, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5188 " forwarding to %s:%.*s%.*s%d%.*s",
5189 (int)(*saddr?
strlen(saddr
):0), *saddr?saddr
:NULL
,
5190 (int)(*saddr?
1:0), ":",
5191 (int)(sserv ?
strlen(sports
) : 0), sports
,
5192 sserv
, "(", sport
, sserv
, ")",
5194 (int)(dserv ?
strlen(dports
) : 0), dports
,
5195 dserv
, "(", dport
, dserv
, ")");
5197 struct ssh_rportfwd
*pf
;
5198 pf
= smalloc(sizeof(*pf
));
5199 strcpy(pf
->dhost
, host
);
5202 if (add234(ssh
->rportfwds
, pf
) != pf
) {
5203 logeventf(ssh
, "Duplicate remote port forwarding"
5204 " to %s:%d", host
, dport
);
5207 logeventf(ssh
, "Requesting remote port "
5208 "%.*s%.*s%.*s%.*s%d%.*s"
5209 " forward to %s:%.*s%.*s%d%.*s",
5210 (int)(*saddr?
strlen(saddr
):0),
5212 (int)(*saddr?
1:0), ":",
5213 (int)(sserv ?
strlen(sports
) : 0), sports
,
5214 sserv
, "(", sport
, sserv
, ")",
5216 (int)(dserv ?
strlen(dports
) : 0), dports
,
5217 dserv
, "(", dport
, dserv
, ")");
5218 ssh2_pkt_init(ssh
, SSH2_MSG_GLOBAL_REQUEST
);
5219 ssh2_pkt_addstring(ssh
, "tcpip-forward");
5220 ssh2_pkt_addbool(ssh
, 1);/* want reply */
5222 ssh2_pkt_addstring(ssh
, saddr
);
5223 if (cfg
.rport_acceptall
)
5224 ssh2_pkt_addstring(ssh
, "0.0.0.0");
5226 ssh2_pkt_addstring(ssh
, "127.0.0.1");
5227 ssh2_pkt_adduint32(ssh
, sport
);
5231 crWaitUntilV(ispkt
);
5232 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5233 unsigned i
= ssh2_pkt_getuint32(ssh
);
5234 struct ssh_channel
*c
;
5235 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5237 continue;/* nonexistent channel */
5238 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5240 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5242 if (ssh
->pktin
.type
!= SSH2_MSG_REQUEST_SUCCESS
) {
5243 if (ssh
->pktin
.type
!= SSH2_MSG_REQUEST_FAILURE
) {
5244 bombout((ssh
,"Unexpected response to port "
5245 "forwarding request: packet type %d",
5249 logevent("Server refused this port forwarding");
5251 logevent("Remote port forwarding enabled");
5260 * Potentially enable agent forwarding.
5262 if (cfg
.agentfwd
&& agent_exists()) {
5263 logevent("Requesting OpenSSH-style agent forwarding");
5264 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5265 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
5266 ssh2_pkt_addstring(ssh
, "auth-agent-req@openssh.com");
5267 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5271 crWaitUntilV(ispkt
);
5272 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5273 unsigned i
= ssh2_pkt_getuint32(ssh
);
5274 struct ssh_channel
*c
;
5275 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5277 continue; /* nonexistent channel */
5278 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5280 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5282 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5283 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5284 bombout((ssh
,"Unexpected response to agent forwarding request:"
5285 " packet type %d", ssh
->pktin
.type
));
5288 logevent("Agent forwarding refused");
5290 logevent("Agent forwarding enabled");
5291 ssh
->agentfwd_enabled
= TRUE
;
5296 * Now allocate a pty for the session.
5299 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5300 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
); /* recipient channel */
5301 ssh2_pkt_addstring(ssh
, "pty-req");
5302 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5303 ssh2_pkt_addstring(ssh
, cfg
.termtype
);
5304 ssh2_pkt_adduint32(ssh
, ssh
->term_width
);
5305 ssh2_pkt_adduint32(ssh
, ssh
->term_height
);
5306 ssh2_pkt_adduint32(ssh
, 0); /* pixel width */
5307 ssh2_pkt_adduint32(ssh
, 0); /* pixel height */
5308 ssh2_pkt_addstring_start(ssh
);
5309 ssh2_pkt_addstring_data(ssh
, "\0", 1); /* TTY_OP_END, no special options */
5311 ssh
->state
= SSH_STATE_INTERMED
;
5314 crWaitUntilV(ispkt
);
5315 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5316 unsigned i
= ssh2_pkt_getuint32(ssh
);
5317 struct ssh_channel
*c
;
5318 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5320 continue; /* nonexistent channel */
5321 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5323 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5325 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5326 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5327 bombout((ssh
,"Unexpected response to pty request:"
5328 " packet type %d", ssh
->pktin
.type
));
5331 c_write_str(ssh
, "Server refused to allocate pty\r\n");
5332 ssh
->editing
= ssh
->echoing
= 1;
5334 logevent("Allocated pty");
5337 ssh
->editing
= ssh
->echoing
= 1;
5341 * Start a shell or a remote command. We may have to attempt
5342 * this twice if the config data has provided a second choice
5349 if (ssh
->fallback_cmd
) {
5350 subsys
= cfg
.ssh_subsys2
;
5351 cmd
= cfg
.remote_cmd_ptr2
;
5353 subsys
= cfg
.ssh_subsys
;
5354 cmd
= cfg
.remote_cmd_ptr
;
5357 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5358 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
); /* recipient channel */
5360 ssh2_pkt_addstring(ssh
, "subsystem");
5361 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5362 ssh2_pkt_addstring(ssh
, cmd
);
5364 ssh2_pkt_addstring(ssh
, "exec");
5365 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5366 ssh2_pkt_addstring(ssh
, cmd
);
5368 ssh2_pkt_addstring(ssh
, "shell");
5369 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5373 crWaitUntilV(ispkt
);
5374 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5375 unsigned i
= ssh2_pkt_getuint32(ssh
);
5376 struct ssh_channel
*c
;
5377 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5379 continue; /* nonexistent channel */
5380 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5382 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5383 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5384 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5385 bombout((ssh
,"Unexpected response to shell/command request:"
5386 " packet type %d", ssh
->pktin
.type
));
5390 * We failed to start the command. If this is the
5391 * fallback command, we really are finished; if it's
5392 * not, and if the fallback command exists, try falling
5393 * back to it before complaining.
5395 if (!ssh
->fallback_cmd
&& cfg
.remote_cmd_ptr2
!= NULL
) {
5396 logevent("Primary command failed; attempting fallback");
5397 ssh
->fallback_cmd
= TRUE
;
5400 bombout((ssh
,"Server refused to start a shell/command"));
5403 logevent("Started a shell/command");
5408 ssh
->state
= SSH_STATE_SESSION
;
5409 if (ssh
->size_needed
)
5410 ssh_size(ssh
, ssh
->term_width
, ssh
->term_height
);
5411 if (ssh
->eof_needed
)
5412 ssh_special(ssh
, TS_EOF
);
5418 ldisc_send(ssh
->ldisc
, NULL
, 0, 0);/* cause ldisc to notice changes */
5422 s
->try_send
= FALSE
;
5424 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
5425 ssh
->pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
5428 unsigned i
= ssh2_pkt_getuint32(ssh
);
5429 struct ssh_channel
*c
;
5430 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5432 continue; /* nonexistent channel */
5433 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
5434 ssh2_pkt_getuint32(ssh
) != SSH2_EXTENDED_DATA_STDERR
)
5435 continue; /* extended but not stderr */
5436 ssh2_pkt_getstring(ssh
, &data
, &length
);
5439 c
->v
.v2
.locwindow
-= length
;
5441 case CHAN_MAINSESSION
:
5443 from_backend(ssh
->frontend
, ssh
->pktin
.type
==
5444 SSH2_MSG_CHANNEL_EXTENDED_DATA
,
5448 bufsize
= x11_send(c
->u
.x11
.s
, data
, length
);
5451 bufsize
= pfd_send(c
->u
.pfd
.s
, data
, length
);
5454 while (length
> 0) {
5455 if (c
->u
.a
.lensofar
< 4) {
5456 int l
= min(4 - c
->u
.a
.lensofar
, length
);
5457 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
,
5461 c
->u
.a
.lensofar
+= l
;
5463 if (c
->u
.a
.lensofar
== 4) {
5465 4 + GET_32BIT(c
->u
.a
.msglen
);
5466 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
5467 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
5469 if (c
->u
.a
.lensofar
>= 4 && length
> 0) {
5471 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
5473 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
,
5477 c
->u
.a
.lensofar
+= l
;
5479 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
5480 void *reply
, *sentreply
;
5482 agent_query(c
->u
.a
.message
,
5483 c
->u
.a
.totallen
, &reply
,
5488 /* Fake SSH_AGENT_FAILURE. */
5489 sentreply
= "\0\0\0\1\5";
5492 ssh2_add_channel_data(c
, sentreply
, replylen
);
5496 sfree(c
->u
.a
.message
);
5497 c
->u
.a
.lensofar
= 0;
5504 * If we are not buffering too much data,
5505 * enlarge the window again at the remote side.
5507 if (bufsize
< OUR_V2_WINSIZE
)
5508 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
5510 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_EOF
) {
5511 unsigned i
= ssh2_pkt_getuint32(ssh
);
5512 struct ssh_channel
*c
;
5514 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5516 continue; /* nonexistent channel */
5518 if (c
->type
== CHAN_X11
) {
5520 * Remote EOF on an X11 channel means we should
5521 * wrap up and close the channel ourselves.
5523 x11_close(c
->u
.x11
.s
);
5525 } else if (c
->type
== CHAN_AGENT
) {
5527 } else if (c
->type
== CHAN_SOCKDATA
) {
5528 pfd_close(c
->u
.pfd
.s
);
5531 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_CLOSE
) {
5532 unsigned i
= ssh2_pkt_getuint32(ssh
);
5533 struct ssh_channel
*c
;
5535 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5536 if (!c
|| ((int)c
->remoteid
) == -1) {
5537 bombout((ssh
,"Received CHANNEL_CLOSE for %s channel %d\n",
5538 c ?
"half-open" : "nonexistent", i
));
5540 /* Do pre-close processing on the channel. */
5542 case CHAN_MAINSESSION
:
5543 break; /* nothing to see here, move along */
5545 if (c
->u
.x11
.s
!= NULL
)
5546 x11_close(c
->u
.x11
.s
);
5553 if (c
->u
.pfd
.s
!= NULL
)
5554 pfd_close(c
->u
.pfd
.s
);
5558 if (c
->closes
== 0) {
5559 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_CLOSE
);
5560 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5563 del234(ssh
->channels
, c
);
5564 bufchain_clear(&c
->v
.v2
.outbuffer
);
5568 * See if that was the last channel left open.
5570 if (count234(ssh
->channels
) == 0) {
5573 * We used to send SSH_MSG_DISCONNECT here,
5574 * because I'd believed that _every_ conforming
5575 * SSH2 connection had to end with a disconnect
5576 * being sent by at least one side; apparently
5577 * I was wrong and it's perfectly OK to
5578 * unceremoniously slam the connection shut
5579 * when you're done, and indeed OpenSSH feels
5580 * this is more polite than sending a
5581 * DISCONNECT. So now we don't.
5583 logevent("All channels closed. Disconnecting");
5584 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
5585 ssh2_pkt_adduint32(ssh
, SSH2_DISCONNECT_BY_APPLICATION
);
5586 ssh2_pkt_addstring(ssh
, "All open channels closed");
5587 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5590 ssh
->state
= SSH_STATE_CLOSED
;
5593 continue; /* remote sends close; ignore (FIXME) */
5594 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5595 unsigned i
= ssh2_pkt_getuint32(ssh
);
5596 struct ssh_channel
*c
;
5597 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5599 continue; /* nonexistent channel */
5600 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5602 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
5603 unsigned i
= ssh2_pkt_getuint32(ssh
);
5604 struct ssh_channel
*c
;
5605 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5607 continue; /* nonexistent channel */
5608 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
5609 continue; /* dunno why they're confirming this */
5610 c
->remoteid
= ssh2_pkt_getuint32(ssh
);
5611 c
->type
= CHAN_SOCKDATA
;
5612 c
->v
.v2
.remwindow
= ssh2_pkt_getuint32(ssh
);
5613 c
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32(ssh
);
5615 pfd_confirm(c
->u
.pfd
.s
);
5618 * We have a pending close on this channel,
5619 * which we decided on before the server acked
5620 * the channel open. So now we know the
5621 * remoteid, we can close it again.
5623 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_CLOSE
);
5624 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5627 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_OPEN_FAILURE
) {
5628 unsigned i
= ssh2_pkt_getuint32(ssh
);
5629 struct ssh_channel
*c
;
5630 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5632 continue; /* nonexistent channel */
5633 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
5634 continue; /* dunno why they're failing this */
5636 logevent("Forwarded connection refused by server");
5638 pfd_close(c
->u
.pfd
.s
);
5640 del234(ssh
->channels
, c
);
5642 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_REQUEST
) {
5645 int typelen
, want_reply
;
5646 struct ssh_channel
*c
;
5648 localid
= ssh2_pkt_getuint32(ssh
);
5649 ssh2_pkt_getstring(ssh
, &type
, &typelen
);
5650 want_reply
= ssh2_pkt_getbool(ssh
);
5653 * First, check that the channel exists. Otherwise,
5654 * we can instantly disconnect with a rude message.
5656 c
= find234(ssh
->channels
, &localid
, ssh_channelfind
);
5659 sprintf(buf
, "Received channel request for nonexistent"
5660 " channel %d", localid
);
5662 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
5663 ssh2_pkt_adduint32(ssh
, SSH2_DISCONNECT_BY_APPLICATION
);
5664 ssh2_pkt_addstring(ssh
, buf
);
5665 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5667 connection_fatal("%s", buf
);
5668 ssh
->state
= SSH_STATE_CLOSED
;
5673 * Having got the channel number, we now look at
5674 * the request type string to see if it's something
5677 if (typelen
== 11 && !memcmp(type
, "exit-status", 11) &&
5678 c
== ssh
->mainchan
) {
5679 /* We recognise "exit-status" on the primary channel. */
5681 ssh
->exitcode
= ssh2_pkt_getuint32(ssh
);
5682 sprintf(buf
, "Server sent command exit status %d",
5686 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_SUCCESS
);
5687 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5692 * This is a channel request we don't know
5693 * about, so we now either ignore the request
5694 * or respond with CHANNEL_FAILURE, depending
5698 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_FAILURE
);
5699 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5703 } else if (ssh
->pktin
.type
== SSH2_MSG_GLOBAL_REQUEST
) {
5705 int typelen
, want_reply
;
5707 ssh2_pkt_getstring(ssh
, &type
, &typelen
);
5708 want_reply
= ssh2_pkt_getbool(ssh
);
5711 * We currently don't support any global requests
5712 * at all, so we either ignore the request or
5713 * respond with REQUEST_FAILURE, depending on
5717 ssh2_pkt_init(ssh
, SSH2_MSG_REQUEST_FAILURE
);
5720 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_OPEN
) {
5724 struct ssh_channel
*c
;
5725 unsigned remid
, winsize
, pktsize
;
5726 ssh2_pkt_getstring(ssh
, &type
, &typelen
);
5727 c
= smalloc(sizeof(struct ssh_channel
));
5730 remid
= ssh2_pkt_getuint32(ssh
);
5731 winsize
= ssh2_pkt_getuint32(ssh
);
5732 pktsize
= ssh2_pkt_getuint32(ssh
);
5734 if (typelen
== 3 && !memcmp(type
, "x11", 3)) {
5735 if (!ssh
->X11_fwd_enabled
)
5736 error
= "X11 forwarding is not enabled";
5737 else if (x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
,
5738 ssh
->x11auth
) != NULL
) {
5739 error
= "Unable to open an X11 connection";
5743 } else if (typelen
== 15 &&
5744 !memcmp(type
, "forwarded-tcpip", 15)) {
5745 struct ssh_rportfwd pf
, *realpf
;
5748 ssh2_pkt_getstring(ssh
, &dummy
, &dummylen
);/* skip address */
5749 pf
.sport
= ssh2_pkt_getuint32(ssh
);
5750 realpf
= find234(ssh
->rportfwds
, &pf
, NULL
);
5751 if (realpf
== NULL
) {
5752 error
= "Remote port is not recognised";
5754 char *e
= pfd_newconnect(&c
->u
.pfd
.s
, realpf
->dhost
,
5756 logeventf(ssh
, "Received remote port open request"
5757 " for %s:%d", realpf
->dhost
, realpf
->dport
);
5759 logeventf(ssh
, "Port open failed: %s", e
);
5760 error
= "Port open failed";
5762 logevent("Forwarded port opened successfully");
5763 c
->type
= CHAN_SOCKDATA
;
5766 } else if (typelen
== 22 &&
5767 !memcmp(type
, "auth-agent@openssh.com", 3)) {
5768 if (!ssh
->agentfwd_enabled
)
5769 error
= "Agent forwarding is not enabled";
5771 c
->type
= CHAN_AGENT
; /* identify channel type */
5772 c
->u
.a
.lensofar
= 0;
5775 error
= "Unsupported channel type requested";
5778 c
->remoteid
= remid
;
5780 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN_FAILURE
);
5781 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5782 ssh2_pkt_adduint32(ssh
, SSH2_OPEN_CONNECT_FAILED
);
5783 ssh2_pkt_addstring(ssh
, error
);
5784 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5788 c
->localid
= alloc_channel_id(ssh
);
5790 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5791 c
->v
.v2
.remwindow
= winsize
;
5792 c
->v
.v2
.remmaxpkt
= pktsize
;
5793 bufchain_init(&c
->v
.v2
.outbuffer
);
5794 add234(ssh
->channels
, c
);
5795 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
5796 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5797 ssh2_pkt_adduint32(ssh
, c
->localid
);
5798 ssh2_pkt_adduint32(ssh
, c
->v
.v2
.locwindow
);
5799 ssh2_pkt_adduint32(ssh
, 0x4000UL
); /* our max pkt size */
5803 bombout((ssh
,"Strange packet received: type %d", ssh
->pktin
.type
));
5808 * We have spare data. Add it to the channel buffer.
5810 ssh2_add_channel_data(ssh
->mainchan
, in
, inlen
);
5815 struct ssh_channel
*c
;
5817 * Try to send data on all channels if we can.
5819 for (i
= 0; NULL
!= (c
= index234(ssh
->channels
, i
)); i
++) {
5820 int bufsize
= ssh2_try_send(c
);
5823 case CHAN_MAINSESSION
:
5824 /* stdin need not receive an unthrottle
5825 * notification since it will be polled */
5828 x11_unthrottle(c
->u
.x11
.s
);
5831 /* agent sockets are request/response and need no
5832 * buffer management */
5835 pfd_unthrottle(c
->u
.pfd
.s
);
5847 * Handle the top-level SSH2 protocol.
5849 static void ssh2_protocol(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
5851 if (do_ssh2_transport(ssh
, in
, inlen
, ispkt
) == 0)
5853 do_ssh2_authconn(ssh
, in
, inlen
, ispkt
);
5857 * Called to set up the connection.
5859 * Returns an error message, or NULL on success.
5861 static char *ssh_init(void *frontend_handle
, void **backend_handle
,
5862 char *host
, int port
, char **realhost
, int nodelay
)
5867 ssh
= smalloc(sizeof(*ssh
));
5870 ssh
->v1_cipher_ctx
= NULL
;
5871 ssh
->crcda_ctx
= NULL
;
5872 ssh
->cscipher
= NULL
;
5873 ssh
->cs_cipher_ctx
= NULL
;
5874 ssh
->sccipher
= NULL
;
5875 ssh
->sc_cipher_ctx
= NULL
;
5877 ssh
->cs_mac_ctx
= NULL
;
5879 ssh
->sc_mac_ctx
= NULL
;
5881 ssh
->cs_comp_ctx
= NULL
;
5883 ssh
->sc_comp_ctx
= NULL
;
5885 ssh
->hostkey
= NULL
;
5887 ssh
->state
= SSH_STATE_PREPACKET
;
5888 ssh
->size_needed
= FALSE
;
5889 ssh
->eof_needed
= FALSE
;
5893 static const struct Packet empty
= { 0, 0, NULL
, NULL
, 0 };
5894 ssh
->pktin
= ssh
->pktout
= empty
;
5896 ssh
->deferred_send_data
= NULL
;
5897 ssh
->deferred_len
= 0;
5898 ssh
->deferred_size
= 0;
5899 ssh
->fallback_cmd
= 0;
5901 ssh
->x11auth
= NULL
;
5902 ssh
->v1_compressing
= FALSE
;
5903 ssh
->v2_outgoing_sequence
= 0;
5904 ssh
->ssh1_rdpkt_crstate
= 0;
5905 ssh
->ssh2_rdpkt_crstate
= 0;
5906 ssh
->do_ssh_init_crstate
= 0;
5907 ssh
->ssh_gotdata_crstate
= 0;
5908 ssh
->ssh1_protocol_crstate
= 0;
5909 ssh
->do_ssh1_login_crstate
= 0;
5910 ssh
->do_ssh2_transport_crstate
= 0;
5911 ssh
->do_ssh2_authconn_crstate
= 0;
5912 ssh
->do_ssh_init_state
= NULL
;
5913 ssh
->do_ssh1_login_state
= NULL
;
5914 ssh
->do_ssh2_transport_state
= NULL
;
5915 ssh
->do_ssh2_authconn_state
= NULL
;
5916 ssh
->mainchan
= NULL
;
5917 ssh
->throttled_all
= 0;
5918 ssh
->v1_stdout_throttling
= 0;
5920 *backend_handle
= ssh
;
5923 if (crypto_startup() == 0)
5924 return "Microsoft high encryption pack not installed!";
5927 ssh
->frontend
= frontend_handle
;
5928 ssh
->term_width
= cfg
.width
;
5929 ssh
->term_height
= cfg
.height
;
5934 ssh
->v1_throttle_count
= 0;
5935 ssh
->overall_bufsize
= 0;
5936 ssh
->fallback_cmd
= 0;
5938 p
= connect_to_host(ssh
, host
, port
, realhost
, nodelay
);
5946 * Called to send data down the Telnet connection.
5948 static int ssh_send(void *handle
, char *buf
, int len
)
5950 Ssh ssh
= (Ssh
) handle
;
5952 if (ssh
== NULL
|| ssh
->s
== NULL
|| ssh
->protocol
== NULL
)
5955 ssh
->protocol(ssh
, buf
, len
, 0);
5957 return ssh_sendbuffer(ssh
);
5961 * Called to query the current amount of buffered stdin data.
5963 static int ssh_sendbuffer(void *handle
)
5965 Ssh ssh
= (Ssh
) handle
;
5968 if (ssh
== NULL
|| ssh
->s
== NULL
|| ssh
->protocol
== NULL
)
5972 * If the SSH socket itself has backed up, add the total backup
5973 * size on that to any individual buffer on the stdin channel.
5976 if (ssh
->throttled_all
)
5977 override_value
= ssh
->overall_bufsize
;
5979 if (ssh
->version
== 1) {
5980 return override_value
;
5981 } else if (ssh
->version
== 2) {
5982 if (!ssh
->mainchan
|| ssh
->mainchan
->closes
> 0)
5983 return override_value
;
5985 return (override_value
+
5986 bufchain_size(&ssh
->mainchan
->v
.v2
.outbuffer
));
5993 * Called to set the size of the window from SSH's POV.
5995 static void ssh_size(void *handle
, int width
, int height
)
5997 Ssh ssh
= (Ssh
) handle
;
5999 ssh
->term_width
= width
;
6000 ssh
->term_height
= height
;
6002 switch (ssh
->state
) {
6003 case SSH_STATE_BEFORE_SIZE
:
6004 case SSH_STATE_PREPACKET
:
6005 case SSH_STATE_CLOSED
:
6006 break; /* do nothing */
6007 case SSH_STATE_INTERMED
:
6008 ssh
->size_needed
= TRUE
; /* buffer for later */
6010 case SSH_STATE_SESSION
:
6012 if (ssh
->version
== 1) {
6013 send_packet(ssh
, SSH1_CMSG_WINDOW_SIZE
,
6014 PKT_INT
, ssh
->term_height
,
6015 PKT_INT
, ssh
->term_width
,
6016 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
6018 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
6019 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
6020 ssh2_pkt_addstring(ssh
, "window-change");
6021 ssh2_pkt_addbool(ssh
, 0);
6022 ssh2_pkt_adduint32(ssh
, ssh
->term_width
);
6023 ssh2_pkt_adduint32(ssh
, ssh
->term_height
);
6024 ssh2_pkt_adduint32(ssh
, 0);
6025 ssh2_pkt_adduint32(ssh
, 0);
6034 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6035 * can send an EOF and collect resulting output (e.g. `plink
6038 static void ssh_special(void *handle
, Telnet_Special code
)
6040 Ssh ssh
= (Ssh
) handle
;
6042 if (code
== TS_EOF
) {
6043 if (ssh
->state
!= SSH_STATE_SESSION
) {
6045 * Buffer the EOF in case we are pre-SESSION, so we can
6046 * send it as soon as we reach SESSION.
6049 ssh
->eof_needed
= TRUE
;
6052 if (ssh
->version
== 1) {
6053 send_packet(ssh
, SSH1_CMSG_EOF
, PKT_END
);
6055 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_EOF
);
6056 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
6059 logevent("Sent EOF message");
6060 } else if (code
== TS_PING
) {
6061 if (ssh
->state
== SSH_STATE_CLOSED
6062 || ssh
->state
== SSH_STATE_PREPACKET
) return;
6063 if (ssh
->version
== 1) {
6064 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
))
6065 send_packet(ssh
, SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
6067 ssh2_pkt_init(ssh
, SSH2_MSG_IGNORE
);
6068 ssh2_pkt_addstring_start(ssh
);
6076 void *new_sock_channel(void *handle
, Socket s
)
6078 Ssh ssh
= (Ssh
) handle
;
6079 struct ssh_channel
*c
;
6080 c
= smalloc(sizeof(struct ssh_channel
));
6084 c
->remoteid
= -1; /* to be set when open confirmed */
6085 c
->localid
= alloc_channel_id(ssh
);
6087 c
->type
= CHAN_SOCKDATA_DORMANT
;/* identify channel type */
6089 bufchain_init(&c
->v
.v2
.outbuffer
);
6090 add234(ssh
->channels
, c
);
6096 * This is called when stdout/stderr (the entity to which
6097 * from_backend sends data) manages to clear some backlog.
6099 void ssh_unthrottle(void *handle
, int bufsize
)
6101 Ssh ssh
= (Ssh
) handle
;
6102 if (ssh
->version
== 1) {
6103 if (ssh
->v1_stdout_throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
6104 ssh
->v1_stdout_throttling
= 0;
6105 ssh1_throttle(ssh
, -1);
6108 if (ssh
->mainchan
&& ssh
->mainchan
->closes
== 0)
6109 ssh2_set_window(ssh
->mainchan
, OUR_V2_WINSIZE
- bufsize
);
6113 void ssh_send_port_open(void *channel
, char *hostname
, int port
, char *org
)
6115 struct ssh_channel
*c
= (struct ssh_channel
*)channel
;
6118 logeventf(ssh
, "Opening forwarded connection to %s:%d", hostname
, port
);
6120 if (ssh
->version
== 1) {
6121 send_packet(ssh
, SSH1_MSG_PORT_OPEN
,
6122 PKT_INT
, c
->localid
,
6125 //PKT_STR, <org:orgport>,
6128 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN
);
6129 ssh2_pkt_addstring(ssh
, "direct-tcpip");
6130 ssh2_pkt_adduint32(ssh
, c
->localid
);
6131 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
6132 ssh2_pkt_adduint32(ssh
, c
->v
.v2
.locwindow
);/* our window size */
6133 ssh2_pkt_adduint32(ssh
, 0x4000UL
); /* our max pkt size */
6134 ssh2_pkt_addstring(ssh
, hostname
);
6135 ssh2_pkt_adduint32(ssh
, port
);
6137 * We make up values for the originator data; partly it's
6138 * too much hassle to keep track, and partly I'm not
6139 * convinced the server should be told details like that
6140 * about my local network configuration.
6142 ssh2_pkt_addstring(ssh
, "client-side-connection");
6143 ssh2_pkt_adduint32(ssh
, 0);
6149 static Socket
ssh_socket(void *handle
)
6151 Ssh ssh
= (Ssh
) handle
;
6155 static int ssh_sendok(void *handle
)
6157 Ssh ssh
= (Ssh
) handle
;
6158 return ssh
->send_ok
;
6161 static int ssh_ldisc(void *handle
, int option
)
6163 Ssh ssh
= (Ssh
) handle
;
6164 if (option
== LD_ECHO
)
6165 return ssh
->echoing
;
6166 if (option
== LD_EDIT
)
6167 return ssh
->editing
;
6171 static void ssh_provide_ldisc(void *handle
, void *ldisc
)
6173 Ssh ssh
= (Ssh
) handle
;
6177 static void ssh_provide_logctx(void *handle
, void *logctx
)
6179 Ssh ssh
= (Ssh
) handle
;
6180 ssh
->logctx
= logctx
;
6183 static int ssh_return_exitcode(void *handle
)
6185 Ssh ssh
= (Ssh
) handle
;
6186 return ssh
->exitcode
;
6190 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6191 * that fails. This variable is the means by which scp.c can reach
6192 * into the SSH code and find out which one it got.
6194 extern int ssh_fallback_cmd(void *handle
)
6196 Ssh ssh
= (Ssh
) handle
;
6197 return ssh
->fallback_cmd
;
6200 Backend ssh_backend
= {
6207 ssh_return_exitcode
,