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
, int port
,
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); \
642 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
643 { fprintf(stderr, "%s\n", s); fflush(stderr); } }
645 /* logevent, only printf-formatted. */
646 void logeventf(Ssh ssh
, char *fmt
, ...)
652 vsprintf(stuff
, fmt
, ap
);
657 #define bombout(msg) ( ssh->state = SSH_STATE_CLOSED, \
658 (ssh->s ? sk_close(ssh->s), ssh->s = NULL : 0), \
659 logeventf msg, connection_fatal msg )
661 static int ssh_channelcmp(void *av
, void *bv
)
663 struct ssh_channel
*a
= (struct ssh_channel
*) av
;
664 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
665 if (a
->localid
< b
->localid
)
667 if (a
->localid
> b
->localid
)
671 static int ssh_channelfind(void *av
, void *bv
)
673 unsigned *a
= (unsigned *) av
;
674 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
682 static int ssh_rportcmp_ssh1(void *av
, void *bv
)
684 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
685 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
687 if ( (i
= strcmp(a
->dhost
, b
->dhost
)) != 0)
688 return i
< 0 ?
-1 : +1;
689 if (a
->dport
> b
->dport
)
691 if (a
->dport
< b
->dport
)
696 static int ssh_rportcmp_ssh2(void *av
, void *bv
)
698 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
699 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
701 if (a
->sport
> b
->sport
)
703 if (a
->sport
< b
->sport
)
708 static int alloc_channel_id(Ssh ssh
)
710 const unsigned CHANNEL_NUMBER_OFFSET
= 256;
711 unsigned low
, high
, mid
;
713 struct ssh_channel
*c
;
716 * First-fit allocation of channel numbers: always pick the
717 * lowest unused one. To do this, binary-search using the
718 * counted B-tree to find the largest channel ID which is in a
719 * contiguous sequence from the beginning. (Precisely
720 * everything in that sequence must have ID equal to its tree
721 * index plus CHANNEL_NUMBER_OFFSET.)
723 tsize
= count234(ssh
->channels
);
727 while (high
- low
> 1) {
728 mid
= (high
+ low
) / 2;
729 c
= index234(ssh
->channels
, mid
);
730 if (c
->localid
== mid
+ CHANNEL_NUMBER_OFFSET
)
731 low
= mid
; /* this one is fine */
733 high
= mid
; /* this one is past it */
736 * Now low points to either -1, or the tree index of the
737 * largest ID in the initial sequence.
740 unsigned i
= low
+ 1 + CHANNEL_NUMBER_OFFSET
;
741 assert(NULL
== find234(ssh
->channels
, &i
, ssh_channelfind
));
743 return low
+ 1 + CHANNEL_NUMBER_OFFSET
;
746 static void c_write(Ssh ssh
, char *buf
, int len
)
748 if ((flags
& FLAG_STDERR
)) {
750 for (i
= 0; i
< len
; i
++)
752 fputc(buf
[i
], stderr
);
755 from_backend(ssh
->frontend
, 1, buf
, len
);
758 static void c_write_untrusted(Ssh ssh
, char *buf
, int len
)
761 for (i
= 0; i
< len
; i
++) {
763 c_write(ssh
, "\r\n", 2);
764 else if ((buf
[i
] & 0x60) || (buf
[i
] == '\r'))
765 c_write(ssh
, buf
+ i
, 1);
769 static void c_write_str(Ssh ssh
, char *buf
)
771 c_write(ssh
, buf
, strlen(buf
));
775 * Collect incoming data in the incoming packet buffer.
776 * Decipher and verify the packet when it is completely read.
777 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
778 * Update the *data and *datalen variables.
779 * Return the additional nr of bytes needed, or 0 when
780 * a complete packet is available.
782 static int ssh1_rdpkt(Ssh ssh
, unsigned char **data
, int *datalen
)
784 struct rdpkt1_state_tag
*st
= &ssh
->rdpkt1_state
;
786 crBegin(ssh
->ssh1_rdpkt_crstate
);
791 ssh
->pktin
.length
= 0;
793 for (st
->i
= st
->len
= 0; st
->i
< 4; st
->i
++) {
794 while ((*datalen
) == 0)
796 st
->len
= (st
->len
<< 8) + **data
;
797 (*data
)++, (*datalen
)--;
800 st
->pad
= 8 - (st
->len
% 8);
801 st
->biglen
= st
->len
+ st
->pad
;
802 ssh
->pktin
.length
= st
->len
- 5;
804 if (ssh
->pktin
.maxlen
< st
->biglen
) {
805 ssh
->pktin
.maxlen
= st
->biglen
;
806 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
, st
->biglen
+ APIEXTRA
);
809 st
->to_read
= st
->biglen
;
810 st
->p
= ssh
->pktin
.data
;
811 while (st
->to_read
> 0) {
812 st
->chunk
= st
->to_read
;
813 while ((*datalen
) == 0)
814 crReturn(st
->to_read
);
815 if (st
->chunk
> (*datalen
))
816 st
->chunk
= (*datalen
);
817 memcpy(st
->p
, *data
, st
->chunk
);
819 *datalen
-= st
->chunk
;
821 st
->to_read
-= st
->chunk
;
824 if (ssh
->cipher
&& detect_attack(ssh
->crcda_ctx
, ssh
->pktin
.data
,
826 bombout((ssh
,"Network attack (CRC compensation) detected!"));
831 ssh
->cipher
->decrypt(ssh
->v1_cipher_ctx
, ssh
->pktin
.data
, st
->biglen
);
833 st
->realcrc
= crc32(ssh
->pktin
.data
, st
->biglen
- 4);
834 st
->gotcrc
= GET_32BIT(ssh
->pktin
.data
+ st
->biglen
- 4);
835 if (st
->gotcrc
!= st
->realcrc
) {
836 bombout((ssh
,"Incorrect CRC received on packet"));
840 ssh
->pktin
.body
= ssh
->pktin
.data
+ st
->pad
+ 1;
842 if (ssh
->v1_compressing
) {
843 unsigned char *decompblk
;
845 zlib_decompress_block(ssh
->sc_comp_ctx
,
846 ssh
->pktin
.body
- 1, ssh
->pktin
.length
+ 1,
847 &decompblk
, &decomplen
);
849 if (ssh
->pktin
.maxlen
< st
->pad
+ decomplen
) {
850 ssh
->pktin
.maxlen
= st
->pad
+ decomplen
;
851 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
,
852 ssh
->pktin
.maxlen
+ APIEXTRA
);
853 ssh
->pktin
.body
= ssh
->pktin
.data
+ st
->pad
+ 1;
856 memcpy(ssh
->pktin
.body
- 1, decompblk
, decomplen
);
858 ssh
->pktin
.length
= decomplen
- 1;
861 ssh
->pktin
.type
= ssh
->pktin
.body
[-1];
864 log_packet(ssh
->logctx
,
865 PKT_INCOMING
, ssh
->pktin
.type
,
866 ssh1_pkt_type(ssh
->pktin
.type
),
867 ssh
->pktin
.body
, ssh
->pktin
.length
);
869 if (ssh
->pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
870 ssh
->pktin
.type
== SSH1_SMSG_STDERR_DATA
||
871 ssh
->pktin
.type
== SSH1_MSG_DEBUG
||
872 ssh
->pktin
.type
== SSH1_SMSG_AUTH_TIS_CHALLENGE
||
873 ssh
->pktin
.type
== SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
874 long stringlen
= GET_32BIT(ssh
->pktin
.body
);
875 if (stringlen
+ 4 != ssh
->pktin
.length
) {
876 bombout((ssh
,"Received data packet with bogus string length"));
881 if (ssh
->pktin
.type
== SSH1_MSG_DEBUG
) {
882 /* log debug message */
884 int stringlen
= GET_32BIT(ssh
->pktin
.body
);
885 strcpy(buf
, "Remote debug message: ");
888 memcpy(buf
+ 8, ssh
->pktin
.body
+ 4, stringlen
);
889 buf
[8 + stringlen
] = '\0';
892 } else if (ssh
->pktin
.type
== SSH1_MSG_IGNORE
) {
897 if (ssh
->pktin
.type
== SSH1_MSG_DISCONNECT
) {
898 /* log reason code in disconnect message */
900 unsigned msglen
= GET_32BIT(ssh
->pktin
.body
);
902 strcpy(buf
, "Remote sent disconnect: ");
903 nowlen
= strlen(buf
);
904 if (msglen
> sizeof(buf
) - nowlen
- 1)
905 msglen
= sizeof(buf
) - nowlen
- 1;
906 memcpy(buf
+ nowlen
, ssh
->pktin
.body
+ 4, msglen
);
907 buf
[nowlen
+ msglen
] = '\0';
908 /* logevent(buf); (this is now done within the bombout macro) */
909 bombout((ssh
,"Server sent disconnect message:\n\"%s\"", buf
+nowlen
));
916 static int ssh2_rdpkt(Ssh ssh
, unsigned char **data
, int *datalen
)
918 struct rdpkt2_state_tag
*st
= &ssh
->rdpkt2_state
;
920 crBegin(ssh
->ssh2_rdpkt_crstate
);
924 ssh
->pktin
.length
= 0;
926 st
->cipherblk
= ssh
->sccipher
->blksize
;
929 if (st
->cipherblk
< 8)
932 if (ssh
->pktin
.maxlen
< st
->cipherblk
) {
933 ssh
->pktin
.maxlen
= st
->cipherblk
;
934 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
, st
->cipherblk
+ APIEXTRA
);
938 * Acquire and decrypt the first block of the packet. This will
939 * contain the length and padding details.
941 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
942 while ((*datalen
) == 0)
943 crReturn(st
->cipherblk
- st
->i
);
944 ssh
->pktin
.data
[st
->i
] = *(*data
)++;
949 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
950 ssh
->pktin
.data
, st
->cipherblk
);
953 * Now get the length and padding figures.
955 st
->len
= GET_32BIT(ssh
->pktin
.data
);
956 st
->pad
= ssh
->pktin
.data
[4];
959 * _Completely_ silly lengths should be stomped on before they
960 * do us any more damage.
962 if (st
->len
< 0 || st
->pad
< 0 || st
->len
+ st
->pad
< 0) {
963 bombout((ssh
,"Incoming packet was garbled on decryption"));
968 * This enables us to deduce the payload length.
970 st
->payload
= st
->len
- st
->pad
- 1;
972 ssh
->pktin
.length
= st
->payload
+ 5;
975 * So now we can work out the total packet length.
977 st
->packetlen
= st
->len
+ 4;
978 st
->maclen
= ssh
->scmac ? ssh
->scmac
->len
: 0;
981 * Adjust memory allocation if packet is too big.
983 if (ssh
->pktin
.maxlen
< st
->packetlen
+ st
->maclen
) {
984 ssh
->pktin
.maxlen
= st
->packetlen
+ st
->maclen
;
985 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
,
986 ssh
->pktin
.maxlen
+ APIEXTRA
);
990 * Read and decrypt the remainder of the packet.
992 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
;
994 while ((*datalen
) == 0)
995 crReturn(st
->packetlen
+ st
->maclen
- st
->i
);
996 ssh
->pktin
.data
[st
->i
] = *(*data
)++;
999 /* Decrypt everything _except_ the MAC. */
1001 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
1002 ssh
->pktin
.data
+ st
->cipherblk
,
1003 st
->packetlen
- st
->cipherblk
);
1009 && !ssh
->scmac
->verify(ssh
->sc_mac_ctx
, ssh
->pktin
.data
, st
->len
+ 4,
1010 st
->incoming_sequence
)) {
1011 bombout((ssh
,"Incorrect MAC received on packet"));
1014 st
->incoming_sequence
++; /* whether or not we MACed */
1017 * Decompress packet payload.
1020 unsigned char *newpayload
;
1023 ssh
->sccomp
->decompress(ssh
->sc_comp_ctx
,
1024 ssh
->pktin
.data
+ 5, ssh
->pktin
.length
- 5,
1025 &newpayload
, &newlen
)) {
1026 if (ssh
->pktin
.maxlen
< newlen
+ 5) {
1027 ssh
->pktin
.maxlen
= newlen
+ 5;
1028 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
,
1029 ssh
->pktin
.maxlen
+ APIEXTRA
);
1031 ssh
->pktin
.length
= 5 + newlen
;
1032 memcpy(ssh
->pktin
.data
+ 5, newpayload
, newlen
);
1037 ssh
->pktin
.savedpos
= 6;
1038 ssh
->pktin
.type
= ssh
->pktin
.data
[5];
1041 log_packet(ssh
->logctx
, PKT_INCOMING
, ssh
->pktin
.type
,
1042 ssh2_pkt_type(ssh
->pkt_ctx
, ssh
->pktin
.type
),
1043 ssh
->pktin
.data
+6, ssh
->pktin
.length
-6);
1045 switch (ssh
->pktin
.type
) {
1047 * These packets we must handle instantly.
1049 case SSH2_MSG_DISCONNECT
:
1051 /* 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 sprintf(buf
, "Received disconnect message (%s)",
1058 ssh2_disconnect_reasons
[reason
]);
1060 sprintf(buf
, "Received disconnect message (unknown type %d)",
1064 strcpy(buf
, "Disconnection message text: ");
1065 nowlen
= strlen(buf
);
1066 if (msglen
> sizeof(buf
) - nowlen
- 1)
1067 msglen
= sizeof(buf
) - nowlen
- 1;
1068 memcpy(buf
+ nowlen
, ssh
->pktin
.data
+ 14, msglen
);
1069 buf
[nowlen
+ msglen
] = '\0';
1071 bombout((ssh
,"Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1073 (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) ?
1074 ssh2_disconnect_reasons
[reason
] : "unknown",
1079 case SSH2_MSG_IGNORE
:
1081 case SSH2_MSG_DEBUG
:
1083 /* log the debug message */
1085 /* int display = ssh->pktin.body[6]; */
1086 int stringlen
= GET_32BIT(ssh
->pktin
.data
+7);
1088 strcpy(buf
, "Remote debug message: ");
1089 prefix
= strlen(buf
);
1090 if (stringlen
> (int)(sizeof(buf
)-prefix
-1))
1091 stringlen
= sizeof(buf
)-prefix
-1;
1092 memcpy(buf
+ prefix
, ssh
->pktin
.data
+ 11, stringlen
);
1093 buf
[prefix
+ stringlen
] = '\0';
1096 goto next_packet
; /* FIXME: print the debug message */
1099 * These packets we need do nothing about here.
1101 case SSH2_MSG_UNIMPLEMENTED
:
1102 case SSH2_MSG_SERVICE_REQUEST
:
1103 case SSH2_MSG_SERVICE_ACCEPT
:
1104 case SSH2_MSG_KEXINIT
:
1105 case SSH2_MSG_NEWKEYS
:
1106 case SSH2_MSG_KEXDH_INIT
:
1107 case SSH2_MSG_KEXDH_REPLY
:
1108 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1109 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1110 case SSH2_MSG_KEX_DH_GEX_INIT
:
1111 case SSH2_MSG_KEX_DH_GEX_REPLY
:
1112 case SSH2_MSG_USERAUTH_REQUEST
:
1113 case SSH2_MSG_USERAUTH_FAILURE
:
1114 case SSH2_MSG_USERAUTH_SUCCESS
:
1115 case SSH2_MSG_USERAUTH_BANNER
:
1116 case SSH2_MSG_USERAUTH_PK_OK
:
1117 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1118 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1119 case SSH2_MSG_USERAUTH_INFO_RESPONSE
:
1120 case SSH2_MSG_GLOBAL_REQUEST
:
1121 case SSH2_MSG_REQUEST_SUCCESS
:
1122 case SSH2_MSG_REQUEST_FAILURE
:
1123 case SSH2_MSG_CHANNEL_OPEN
:
1124 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
:
1125 case SSH2_MSG_CHANNEL_OPEN_FAILURE
:
1126 case SSH2_MSG_CHANNEL_WINDOW_ADJUST
:
1127 case SSH2_MSG_CHANNEL_DATA
:
1128 case SSH2_MSG_CHANNEL_EXTENDED_DATA
:
1129 case SSH2_MSG_CHANNEL_EOF
:
1130 case SSH2_MSG_CHANNEL_CLOSE
:
1131 case SSH2_MSG_CHANNEL_REQUEST
:
1132 case SSH2_MSG_CHANNEL_SUCCESS
:
1133 case SSH2_MSG_CHANNEL_FAILURE
:
1137 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1140 ssh2_pkt_init(ssh
, SSH2_MSG_UNIMPLEMENTED
);
1141 ssh2_pkt_adduint32(ssh
, st
->incoming_sequence
- 1);
1149 static void ssh1_pktout_size(Ssh ssh
, int len
)
1153 len
+= 5; /* type and CRC */
1154 pad
= 8 - (len
% 8);
1157 ssh
->pktout
.length
= len
- 5;
1158 if (ssh
->pktout
.maxlen
< biglen
) {
1159 ssh
->pktout
.maxlen
= biglen
;
1161 /* Allocate enough buffer space for extra block
1162 * for MS CryptEncrypt() */
1163 ssh
->pktout
.data
= srealloc(ssh
->pktout
.data
, biglen
+ 12);
1165 ssh
->pktout
.data
= srealloc(ssh
->pktout
.data
, biglen
+ 4);
1168 ssh
->pktout
.body
= ssh
->pktout
.data
+ 4 + pad
+ 1;
1171 static void s_wrpkt_start(Ssh ssh
, int type
, int len
)
1173 ssh1_pktout_size(ssh
, len
);
1174 ssh
->pktout
.type
= type
;
1177 static int s_wrpkt_prepare(Ssh ssh
)
1179 int pad
, len
, biglen
, i
;
1182 ssh
->pktout
.body
[-1] = ssh
->pktout
.type
;
1185 log_packet(ssh
->logctx
, PKT_OUTGOING
, ssh
->pktout
.type
,
1186 ssh1_pkt_type(ssh
->pktout
.type
),
1187 ssh
->pktout
.body
, ssh
->pktout
.length
);
1189 if (ssh
->v1_compressing
) {
1190 unsigned char *compblk
;
1192 zlib_compress_block(ssh
->cs_comp_ctx
,
1193 ssh
->pktout
.body
- 1, ssh
->pktout
.length
+ 1,
1194 &compblk
, &complen
);
1195 ssh1_pktout_size(ssh
, complen
- 1);
1196 memcpy(ssh
->pktout
.body
- 1, compblk
, complen
);
1200 len
= ssh
->pktout
.length
+ 5; /* type and CRC */
1201 pad
= 8 - (len
% 8);
1204 for (i
= 0; i
< pad
; i
++)
1205 ssh
->pktout
.data
[i
+ 4] = random_byte();
1206 crc
= crc32(ssh
->pktout
.data
+ 4, biglen
- 4);
1207 PUT_32BIT(ssh
->pktout
.data
+ biglen
, crc
);
1208 PUT_32BIT(ssh
->pktout
.data
, len
);
1211 ssh
->cipher
->encrypt(ssh
->v1_cipher_ctx
, ssh
->pktout
.data
+ 4, biglen
);
1216 static void s_wrpkt(Ssh ssh
)
1219 len
= s_wrpkt_prepare(ssh
);
1220 backlog
= sk_write(ssh
->s
, ssh
->pktout
.data
, len
);
1221 if (backlog
> SSH_MAX_BACKLOG
)
1222 ssh_throttle_all(ssh
, 1, backlog
);
1225 static void s_wrpkt_defer(Ssh ssh
)
1228 len
= s_wrpkt_prepare(ssh
);
1229 if (ssh
->deferred_len
+ len
> ssh
->deferred_size
) {
1230 ssh
->deferred_size
= ssh
->deferred_len
+ len
+ 128;
1231 ssh
->deferred_send_data
= srealloc(ssh
->deferred_send_data
,
1232 ssh
->deferred_size
);
1234 memcpy(ssh
->deferred_send_data
+ ssh
->deferred_len
, ssh
->pktout
.data
, len
);
1235 ssh
->deferred_len
+= len
;
1239 * Construct a packet with the specified contents.
1241 static void construct_packet(Ssh ssh
, int pkttype
, va_list ap1
, va_list ap2
)
1243 unsigned char *p
, *argp
, argchar
;
1244 unsigned long argint
;
1245 int pktlen
, argtype
, arglen
;
1249 while ((argtype
= va_arg(ap1
, int)) != PKT_END
) {
1252 (void) va_arg(ap1
, int);
1256 (void) va_arg(ap1
, int);
1260 (void) va_arg(ap1
, unsigned char *);
1261 arglen
= va_arg(ap1
, int);
1265 argp
= va_arg(ap1
, unsigned char *);
1266 arglen
= strlen(argp
);
1267 pktlen
+= 4 + arglen
;
1270 bn
= va_arg(ap1
, Bignum
);
1271 pktlen
+= ssh1_bignum_length(bn
);
1278 s_wrpkt_start(ssh
, pkttype
, pktlen
);
1279 p
= ssh
->pktout
.body
;
1281 while ((argtype
= va_arg(ap2
, int)) != PKT_END
) {
1284 argint
= va_arg(ap2
, int);
1285 PUT_32BIT(p
, argint
);
1289 argchar
= (unsigned char) va_arg(ap2
, int);
1294 argp
= va_arg(ap2
, unsigned char *);
1295 arglen
= va_arg(ap2
, int);
1296 memcpy(p
, argp
, arglen
);
1300 argp
= va_arg(ap2
, unsigned char *);
1301 arglen
= strlen(argp
);
1302 PUT_32BIT(p
, arglen
);
1303 memcpy(p
+ 4, argp
, arglen
);
1307 bn
= va_arg(ap2
, Bignum
);
1308 p
+= ssh1_write_bignum(p
, bn
);
1314 static void send_packet(Ssh ssh
, int pkttype
, ...)
1317 va_start(ap1
, pkttype
);
1318 va_start(ap2
, pkttype
);
1319 construct_packet(ssh
, pkttype
, ap1
, ap2
);
1323 static void defer_packet(Ssh ssh
, int pkttype
, ...)
1326 va_start(ap1
, pkttype
);
1327 va_start(ap2
, pkttype
);
1328 construct_packet(ssh
, pkttype
, ap1
, ap2
);
1332 static int ssh_versioncmp(char *a
, char *b
)
1335 unsigned long av
, bv
;
1337 av
= strtoul(a
, &ae
, 10);
1338 bv
= strtoul(b
, &be
, 10);
1340 return (av
< bv ?
-1 : +1);
1345 av
= strtoul(ae
, &ae
, 10);
1346 bv
= strtoul(be
, &be
, 10);
1348 return (av
< bv ?
-1 : +1);
1353 * Utility routines for putting an SSH-protocol `string' and
1354 * `uint32' into a SHA state.
1357 static void sha_string(SHA_State
* s
, void *str
, int len
)
1359 unsigned char lenblk
[4];
1360 PUT_32BIT(lenblk
, len
);
1361 SHA_Bytes(s
, lenblk
, 4);
1362 SHA_Bytes(s
, str
, len
);
1365 static void sha_uint32(SHA_State
* s
, unsigned i
)
1367 unsigned char intblk
[4];
1368 PUT_32BIT(intblk
, i
);
1369 SHA_Bytes(s
, intblk
, 4);
1373 * SSH2 packet construction functions.
1375 static void ssh2_pkt_ensure(Ssh ssh
, int length
)
1377 if (ssh
->pktout
.maxlen
< length
) {
1378 ssh
->pktout
.maxlen
= length
+ 256;
1379 ssh
->pktout
.data
= srealloc(ssh
->pktout
.data
,
1380 ssh
->pktout
.maxlen
+ APIEXTRA
);
1381 if (!ssh
->pktout
.data
)
1382 fatalbox("Out of memory");
1385 static void ssh2_pkt_adddata(Ssh ssh
, void *data
, int len
)
1387 ssh
->pktout
.length
+= len
;
1388 ssh2_pkt_ensure(ssh
, ssh
->pktout
.length
);
1389 memcpy(ssh
->pktout
.data
+ ssh
->pktout
.length
- len
, data
, len
);
1391 static void ssh2_pkt_addbyte(Ssh ssh
, unsigned char byte
)
1393 ssh2_pkt_adddata(ssh
, &byte
, 1);
1395 static void ssh2_pkt_init(Ssh ssh
, int pkt_type
)
1397 ssh
->pktout
.length
= 5;
1398 ssh2_pkt_addbyte(ssh
, (unsigned char) pkt_type
);
1400 static void ssh2_pkt_addbool(Ssh ssh
, unsigned char value
)
1402 ssh2_pkt_adddata(ssh
, &value
, 1);
1404 static void ssh2_pkt_adduint32(Ssh ssh
, unsigned long value
)
1407 PUT_32BIT(x
, value
);
1408 ssh2_pkt_adddata(ssh
, x
, 4);
1410 static void ssh2_pkt_addstring_start(Ssh ssh
)
1412 ssh2_pkt_adduint32(ssh
, 0);
1413 ssh
->pktout
.savedpos
= ssh
->pktout
.length
;
1415 static void ssh2_pkt_addstring_str(Ssh ssh
, char *data
)
1417 ssh2_pkt_adddata(ssh
, data
, strlen(data
));
1418 PUT_32BIT(ssh
->pktout
.data
+ ssh
->pktout
.savedpos
- 4,
1419 ssh
->pktout
.length
- ssh
->pktout
.savedpos
);
1421 static void ssh2_pkt_addstring_data(Ssh ssh
, char *data
, int len
)
1423 ssh2_pkt_adddata(ssh
, data
, len
);
1424 PUT_32BIT(ssh
->pktout
.data
+ ssh
->pktout
.savedpos
- 4,
1425 ssh
->pktout
.length
- ssh
->pktout
.savedpos
);
1427 static void ssh2_pkt_addstring(Ssh ssh
, char *data
)
1429 ssh2_pkt_addstring_start(ssh
);
1430 ssh2_pkt_addstring_str(ssh
, data
);
1432 static char *ssh2_mpint_fmt(Bignum b
, int *len
)
1435 int i
, n
= (bignum_bitcount(b
) + 7) / 8;
1438 fatalbox("out of memory");
1440 for (i
= 1; i
<= n
; i
++)
1441 p
[i
] = bignum_byte(b
, n
- i
);
1443 while (i
<= n
&& p
[i
] == 0 && (p
[i
+ 1] & 0x80) == 0)
1445 memmove(p
, p
+ i
, n
+ 1 - i
);
1449 static void ssh2_pkt_addmp(Ssh ssh
, Bignum b
)
1453 p
= ssh2_mpint_fmt(b
, &len
);
1454 ssh2_pkt_addstring_start(ssh
);
1455 ssh2_pkt_addstring_data(ssh
, p
, len
);
1460 * Construct an SSH2 final-form packet: compress it, encrypt it,
1461 * put the MAC on it. Final packet, ready to be sent, is stored in
1462 * ssh->pktout.data. Total length is returned.
1464 static int ssh2_pkt_construct(Ssh ssh
)
1466 int cipherblk
, maclen
, padding
, i
;
1469 log_packet(ssh
->logctx
, PKT_OUTGOING
, ssh
->pktout
.data
[5],
1470 ssh2_pkt_type(ssh
->pkt_ctx
, ssh
->pktout
.data
[5]),
1471 ssh
->pktout
.data
+ 6, ssh
->pktout
.length
- 6);
1474 * Compress packet payload.
1477 unsigned char *newpayload
;
1480 ssh
->cscomp
->compress(ssh
->cs_comp_ctx
, ssh
->pktout
.data
+ 5,
1481 ssh
->pktout
.length
- 5,
1482 &newpayload
, &newlen
)) {
1483 ssh
->pktout
.length
= 5;
1484 ssh2_pkt_adddata(ssh
, newpayload
, newlen
);
1490 * Add padding. At least four bytes, and must also bring total
1491 * length (minus MAC) up to a multiple of the block size.
1493 cipherblk
= ssh
->cscipher ? ssh
->cscipher
->blksize
: 8; /* block size */
1494 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
1497 (cipherblk
- (ssh
->pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
1498 maclen
= ssh
->csmac ? ssh
->csmac
->len
: 0;
1499 ssh2_pkt_ensure(ssh
, ssh
->pktout
.length
+ padding
+ maclen
);
1500 ssh
->pktout
.data
[4] = padding
;
1501 for (i
= 0; i
< padding
; i
++)
1502 ssh
->pktout
.data
[ssh
->pktout
.length
+ i
] = random_byte();
1503 PUT_32BIT(ssh
->pktout
.data
, ssh
->pktout
.length
+ padding
- 4);
1505 ssh
->csmac
->generate(ssh
->cs_mac_ctx
, ssh
->pktout
.data
,
1506 ssh
->pktout
.length
+ padding
,
1507 ssh
->v2_outgoing_sequence
);
1508 ssh
->v2_outgoing_sequence
++; /* whether or not we MACed */
1511 ssh
->cscipher
->encrypt(ssh
->cs_cipher_ctx
,
1512 ssh
->pktout
.data
, ssh
->pktout
.length
+ padding
);
1514 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1515 return ssh
->pktout
.length
+ padding
+ maclen
;
1519 * Construct and send an SSH2 packet immediately.
1521 static void ssh2_pkt_send(Ssh ssh
)
1525 len
= ssh2_pkt_construct(ssh
);
1526 backlog
= sk_write(ssh
->s
, ssh
->pktout
.data
, len
);
1527 if (backlog
> SSH_MAX_BACKLOG
)
1528 ssh_throttle_all(ssh
, 1, backlog
);
1532 * Construct an SSH2 packet and add it to a deferred data block.
1533 * Useful for sending multiple packets in a single sk_write() call,
1534 * to prevent a traffic-analysing listener from being able to work
1535 * out the length of any particular packet (such as the password
1538 * Note that because SSH2 sequence-numbers its packets, this can
1539 * NOT be used as an m4-style `defer' allowing packets to be
1540 * constructed in one order and sent in another.
1542 static void ssh2_pkt_defer(Ssh ssh
)
1544 int len
= ssh2_pkt_construct(ssh
);
1545 if (ssh
->deferred_len
+ len
> ssh
->deferred_size
) {
1546 ssh
->deferred_size
= ssh
->deferred_len
+ len
+ 128;
1547 ssh
->deferred_send_data
= srealloc(ssh
->deferred_send_data
,
1548 ssh
->deferred_size
);
1550 memcpy(ssh
->deferred_send_data
+ ssh
->deferred_len
, ssh
->pktout
.data
, len
);
1551 ssh
->deferred_len
+= len
;
1555 * Send the whole deferred data block constructed by
1556 * ssh2_pkt_defer() or SSH1's defer_packet().
1558 static void ssh_pkt_defersend(Ssh ssh
)
1561 backlog
= sk_write(ssh
->s
, ssh
->deferred_send_data
, ssh
->deferred_len
);
1562 ssh
->deferred_len
= ssh
->deferred_size
= 0;
1563 sfree(ssh
->deferred_send_data
);
1564 ssh
->deferred_send_data
= NULL
;
1565 if (backlog
> SSH_MAX_BACKLOG
)
1566 ssh_throttle_all(ssh
, 1, backlog
);
1570 void bndebug(char *string
, Bignum b
)
1574 p
= ssh2_mpint_fmt(b
, &len
);
1575 debug(("%s", string
));
1576 for (i
= 0; i
< len
; i
++)
1577 debug((" %02x", p
[i
]));
1583 static void sha_mpint(SHA_State
* s
, Bignum b
)
1587 p
= ssh2_mpint_fmt(b
, &len
);
1588 sha_string(s
, p
, len
);
1593 * SSH2 packet decode functions.
1595 static unsigned long ssh2_pkt_getuint32(Ssh ssh
)
1597 unsigned long value
;
1598 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< 4)
1599 return 0; /* arrgh, no way to decline (FIXME?) */
1600 value
= GET_32BIT(ssh
->pktin
.data
+ ssh
->pktin
.savedpos
);
1601 ssh
->pktin
.savedpos
+= 4;
1604 static int ssh2_pkt_getbool(Ssh ssh
)
1606 unsigned long value
;
1607 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< 1)
1608 return 0; /* arrgh, no way to decline (FIXME?) */
1609 value
= ssh
->pktin
.data
[ssh
->pktin
.savedpos
] != 0;
1610 ssh
->pktin
.savedpos
++;
1613 static void ssh2_pkt_getstring(Ssh ssh
, char **p
, int *length
)
1617 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< 4)
1619 *length
= GET_32BIT(ssh
->pktin
.data
+ ssh
->pktin
.savedpos
);
1620 ssh
->pktin
.savedpos
+= 4;
1621 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< *length
)
1623 *p
= ssh
->pktin
.data
+ ssh
->pktin
.savedpos
;
1624 ssh
->pktin
.savedpos
+= *length
;
1626 static Bignum
ssh2_pkt_getmp(Ssh ssh
)
1632 ssh2_pkt_getstring(ssh
, &p
, &length
);
1636 bombout((ssh
,"internal error: Can't handle negative mpints"));
1639 b
= bignum_from_bytes(p
, length
);
1644 * Helper function to add an SSH2 signature blob to a packet.
1645 * Expects to be shown the public key blob as well as the signature
1646 * blob. Normally works just like ssh2_pkt_addstring, but will
1647 * fiddle with the signature packet if necessary for
1648 * BUG_SSH2_RSA_PADDING.
1650 static void ssh2_add_sigblob(Ssh ssh
, void *pkblob_v
, int pkblob_len
,
1651 void *sigblob_v
, int sigblob_len
)
1653 unsigned char *pkblob
= (unsigned char *)pkblob_v
;
1654 unsigned char *sigblob
= (unsigned char *)sigblob_v
;
1656 /* dmemdump(pkblob, pkblob_len); */
1657 /* dmemdump(sigblob, sigblob_len); */
1660 * See if this is in fact an ssh-rsa signature and a buggy
1661 * server; otherwise we can just do this the easy way.
1663 if ((ssh
->remote_bugs
& BUG_SSH2_RSA_PADDING
) &&
1664 (GET_32BIT(pkblob
) == 7 && !memcmp(pkblob
+4, "ssh-rsa", 7))) {
1665 int pos
, len
, siglen
;
1668 * Find the byte length of the modulus.
1671 pos
= 4+7; /* skip over "ssh-rsa" */
1672 pos
+= 4 + GET_32BIT(pkblob
+pos
); /* skip over exponent */
1673 len
= GET_32BIT(pkblob
+pos
); /* find length of modulus */
1674 pos
+= 4; /* find modulus itself */
1675 while (len
> 0 && pkblob
[pos
] == 0)
1677 /* debug(("modulus length is %d\n", len)); */
1680 * Now find the signature integer.
1682 pos
= 4+7; /* skip over "ssh-rsa" */
1683 siglen
= GET_32BIT(sigblob
+pos
);
1684 /* debug(("signature length is %d\n", siglen)); */
1686 if (len
!= siglen
) {
1687 unsigned char newlen
[4];
1688 ssh2_pkt_addstring_start(ssh
);
1689 ssh2_pkt_addstring_data(ssh
, sigblob
, pos
);
1690 /* dmemdump(sigblob, pos); */
1691 pos
+= 4; /* point to start of actual sig */
1692 PUT_32BIT(newlen
, len
);
1693 ssh2_pkt_addstring_data(ssh
, newlen
, 4);
1694 /* dmemdump(newlen, 4); */
1696 while (len
-- > siglen
) {
1697 ssh2_pkt_addstring_data(ssh
, newlen
, 1);
1698 /* dmemdump(newlen, 1); */
1700 ssh2_pkt_addstring_data(ssh
, sigblob
+pos
, siglen
);
1701 /* dmemdump(sigblob+pos, siglen); */
1705 /* Otherwise fall through and do it the easy way. */
1708 ssh2_pkt_addstring_start(ssh
);
1709 ssh2_pkt_addstring_data(ssh
, sigblob
, sigblob_len
);
1713 * Examine the remote side's version string and compare it against
1714 * a list of known buggy implementations.
1716 static void ssh_detect_bugs(Ssh ssh
, char *vstring
)
1718 char *imp
; /* pointer to implementation part */
1720 imp
+= strcspn(imp
, "-");
1722 imp
+= strcspn(imp
, "-");
1725 ssh
->remote_bugs
= 0;
1727 if (cfg
.sshbug_ignore1
== BUG_ON
||
1728 (cfg
.sshbug_ignore1
== BUG_AUTO
&&
1729 (!strcmp(imp
, "1.2.18") || !strcmp(imp
, "1.2.19") ||
1730 !strcmp(imp
, "1.2.20") || !strcmp(imp
, "1.2.21") ||
1731 !strcmp(imp
, "1.2.22") || !strcmp(imp
, "Cisco-1.25")))) {
1733 * These versions don't support SSH1_MSG_IGNORE, so we have
1734 * to use a different defence against password length
1737 ssh
->remote_bugs
|= BUG_CHOKES_ON_SSH1_IGNORE
;
1738 logevent("We believe remote version has SSH1 ignore bug");
1741 if (cfg
.sshbug_plainpw1
== BUG_ON
||
1742 (cfg
.sshbug_plainpw1
== BUG_AUTO
&&
1743 (!strcmp(imp
, "Cisco-1.25")))) {
1745 * These versions need a plain password sent; they can't
1746 * handle having a null and a random length of data after
1749 ssh
->remote_bugs
|= BUG_NEEDS_SSH1_PLAIN_PASSWORD
;
1750 logevent("We believe remote version needs a plain SSH1 password");
1753 if (cfg
.sshbug_rsa1
== BUG_ON
||
1754 (cfg
.sshbug_rsa1
== BUG_AUTO
&&
1755 (!strcmp(imp
, "Cisco-1.25")))) {
1757 * These versions apparently have no clue whatever about
1758 * RSA authentication and will panic and die if they see
1759 * an AUTH_RSA message.
1761 ssh
->remote_bugs
|= BUG_CHOKES_ON_RSA
;
1762 logevent("We believe remote version can't handle RSA authentication");
1765 if (cfg
.sshbug_hmac2
== BUG_ON
||
1766 (cfg
.sshbug_hmac2
== BUG_AUTO
&&
1767 (!strncmp(imp
, "2.1.0", 5) || !strncmp(imp
, "2.0.", 4) ||
1768 !strncmp(imp
, "2.2.0", 5) || !strncmp(imp
, "2.3.0", 5) ||
1769 !strncmp(imp
, "2.1 ", 4)))) {
1771 * These versions have the HMAC bug.
1773 ssh
->remote_bugs
|= BUG_SSH2_HMAC
;
1774 logevent("We believe remote version has SSH2 HMAC bug");
1777 if (cfg
.sshbug_derivekey2
== BUG_ON
||
1778 (cfg
.sshbug_derivekey2
== BUG_AUTO
&&
1779 (!strncmp(imp
, "2.0.", 4)))) {
1781 * These versions have the key-derivation bug (failing to
1782 * include the literal shared secret in the hashes that
1783 * generate the keys).
1785 ssh
->remote_bugs
|= BUG_SSH2_DERIVEKEY
;
1786 logevent("We believe remote version has SSH2 key-derivation bug");
1789 if (cfg
.sshbug_rsapad2
== BUG_ON
||
1790 (cfg
.sshbug_rsapad2
== BUG_AUTO
&&
1791 ((!strncmp(imp
, "OpenSSH_2.", 10) && imp
[10]>='5' && imp
[10]<='9') ||
1792 (!strncmp(imp
, "OpenSSH_3.", 10) && imp
[10]>='0' && imp
[10]<='2')))){
1794 * These versions have the SSH2 RSA padding bug.
1796 ssh
->remote_bugs
|= BUG_SSH2_RSA_PADDING
;
1797 logevent("We believe remote version has SSH2 RSA padding bug");
1800 if (cfg
.sshbug_dhgex2
== BUG_ON
) {
1802 * These versions have the SSH2 DH GEX bug.
1804 ssh
->remote_bugs
|= BUG_SSH2_DH_GEX
;
1805 logevent("We believe remote version has SSH2 DH group exchange bug");
1809 static int do_ssh_init(Ssh ssh
, unsigned char c
)
1811 struct do_ssh_init_state
{
1819 crState(do_ssh_init_state
);
1821 crBegin(ssh
->do_ssh_init_crstate
);
1823 /* Search for the string "SSH-" in the input. */
1826 static const int transS
[] = { 1, 2, 2, 1 };
1827 static const int transH
[] = { 0, 0, 3, 0 };
1828 static const int transminus
[] = { 0, 0, 0, -1 };
1830 s
->i
= transS
[s
->i
];
1832 s
->i
= transH
[s
->i
];
1834 s
->i
= transminus
[s
->i
];
1839 crReturn(1); /* get another character */
1843 s
->vstring
= smalloc(s
->vstrsize
);
1844 strcpy(s
->vstring
, "SSH-");
1848 crReturn(1); /* get another char */
1849 if (s
->vslen
>= s
->vstrsize
- 1) {
1851 s
->vstring
= srealloc(s
->vstring
, s
->vstrsize
);
1853 s
->vstring
[s
->vslen
++] = c
;
1856 s
->version
[s
->i
] = '\0';
1858 } else if (s
->i
< sizeof(s
->version
) - 1)
1859 s
->version
[s
->i
++] = c
;
1860 } else if (c
== '\n')
1864 ssh
->agentfwd_enabled
= FALSE
;
1865 ssh
->rdpkt2_state
.incoming_sequence
= 0;
1867 s
->vstring
[s
->vslen
] = 0;
1868 s
->vstring
[strcspn(s
->vstring
, "\r\n")] = '\0';/* remove EOL chars */
1871 vlog
= smalloc(20 + s
->vslen
);
1872 sprintf(vlog
, "Server version: %s", s
->vstring
);
1876 ssh_detect_bugs(ssh
, s
->vstring
);
1879 * Decide which SSH protocol version to support.
1882 /* Anything strictly below "2.0" means protocol 1 is supported. */
1883 s
->proto1
= ssh_versioncmp(s
->version
, "2.0") < 0;
1884 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
1885 s
->proto2
= ssh_versioncmp(s
->version
, "1.99") >= 0;
1887 if (cfg
.sshprot
== 0 && !s
->proto1
) {
1888 bombout((ssh
,"SSH protocol version 1 required by user but not provided by server"));
1891 if (cfg
.sshprot
== 3 && !s
->proto2
) {
1892 bombout((ssh
,"SSH protocol version 2 required by user but not provided by server"));
1896 if (s
->proto2
&& (cfg
.sshprot
>= 2 || !s
->proto1
)) {
1900 char verstring
[80], vlog
[100];
1901 sprintf(verstring
, "SSH-2.0-%s", sshver
);
1902 SHA_Init(&ssh
->exhashbase
);
1904 * Hash our version string and their version string.
1906 sha_string(&ssh
->exhashbase
, verstring
, strlen(verstring
));
1907 sha_string(&ssh
->exhashbase
, s
->vstring
, strcspn(s
->vstring
, "\r\n"));
1908 sprintf(vlog
, "We claim version: %s", verstring
);
1910 strcat(verstring
, "\n");
1911 logevent("Using SSH protocol version 2");
1912 sk_write(ssh
->s
, verstring
, strlen(verstring
));
1913 ssh
->protocol
= ssh2_protocol
;
1915 ssh
->s_rdpkt
= ssh2_rdpkt
;
1920 char verstring
[80], vlog
[100];
1921 sprintf(verstring
, "SSH-%s-%s",
1922 (ssh_versioncmp(s
->version
, "1.5") <= 0 ? s
->version
: "1.5"),
1924 sprintf(vlog
, "We claim version: %s", verstring
);
1926 strcat(verstring
, "\n");
1928 logevent("Using SSH protocol version 1");
1929 sk_write(ssh
->s
, verstring
, strlen(verstring
));
1930 ssh
->protocol
= ssh1_protocol
;
1932 ssh
->s_rdpkt
= ssh1_rdpkt
;
1934 ssh
->state
= SSH_STATE_BEFORE_SIZE
;
1941 static void ssh_gotdata(Ssh ssh
, unsigned char *data
, int datalen
)
1943 crBegin(ssh
->ssh_gotdata_crstate
);
1946 * To begin with, feed the characters one by one to the
1947 * protocol initialisation / selection function do_ssh_init().
1948 * When that returns 0, we're done with the initial greeting
1949 * exchange and can move on to packet discipline.
1952 int ret
; /* need not be kept across crReturn */
1954 crReturnV
; /* more data please */
1955 ret
= do_ssh_init(ssh
, *data
);
1963 * We emerge from that loop when the initial negotiation is
1964 * over and we have selected an s_rdpkt function. Now pass
1965 * everything to s_rdpkt, and then pass the resulting packets
1966 * to the proper protocol handler.
1971 while (datalen
> 0) {
1972 if (ssh
->s_rdpkt(ssh
, &data
, &datalen
) == 0) {
1973 if (ssh
->state
== SSH_STATE_CLOSED
) {
1976 ssh
->protocol(ssh
, NULL
, 0, 1);
1977 if (ssh
->state
== SSH_STATE_CLOSED
) {
1987 static int ssh_closing(Plug plug
, char *error_msg
, int error_code
,
1990 Ssh ssh
= (Ssh
) plug
;
1991 ssh
->state
= SSH_STATE_CLOSED
;
1997 /* A socket error has occurred. */
1998 logevent(error_msg
);
1999 connection_fatal(ssh
->frontend
, error_msg
);
2001 /* Otherwise, the remote side closed the connection normally. */
2006 static int ssh_receive(Plug plug
, int urgent
, char *data
, int len
)
2008 Ssh ssh
= (Ssh
) plug
;
2009 ssh_gotdata(ssh
, data
, len
);
2010 if (ssh
->state
== SSH_STATE_CLOSED
) {
2020 static void ssh_sent(Plug plug
, int bufsize
)
2022 Ssh ssh
= (Ssh
) plug
;
2024 * If the send backlog on the SSH socket itself clears, we
2025 * should unthrottle the whole world if it was throttled.
2027 if (bufsize
< SSH_MAX_BACKLOG
)
2028 ssh_throttle_all(ssh
, 0, bufsize
);
2032 * Connect to specified host and port.
2033 * Returns an error message, or NULL on success.
2034 * Also places the canonical host name into `realhost'. It must be
2035 * freed by the caller.
2037 static char *connect_to_host(Ssh ssh
, char *host
, int port
,
2038 char **realhost
, int nodelay
)
2040 static const struct plug_function_table fn_table
= {
2050 ssh
->savedhost
= smalloc(1 + strlen(host
));
2051 if (!ssh
->savedhost
)
2052 fatalbox("Out of memory");
2053 strcpy(ssh
->savedhost
, host
);
2056 port
= 22; /* default ssh port */
2057 ssh
->savedport
= port
;
2064 sprintf(buf
, "Looking up host \"%.170s\"", host
);
2067 addr
= sk_namelookup(host
, realhost
);
2068 if ((err
= sk_addr_error(addr
)))
2075 char buf
[200], addrbuf
[100];
2076 sk_getaddr(addr
, addrbuf
, 100);
2077 sprintf(buf
, "Connecting to %.100s port %d", addrbuf
, port
);
2080 ssh
->fn
= &fn_table
;
2081 ssh
->s
= new_connection(addr
, *realhost
, port
, 0, 1, nodelay
, (Plug
) ssh
);
2082 if ((err
= sk_socket_error(ssh
->s
))) {
2091 * Throttle or unthrottle the SSH connection.
2093 static void ssh1_throttle(Ssh ssh
, int adjust
)
2095 int old_count
= ssh
->v1_throttle_count
;
2096 ssh
->v1_throttle_count
+= adjust
;
2097 assert(ssh
->v1_throttle_count
>= 0);
2098 if (ssh
->v1_throttle_count
&& !old_count
) {
2099 sk_set_frozen(ssh
->s
, 1);
2100 } else if (!ssh
->v1_throttle_count
&& old_count
) {
2101 sk_set_frozen(ssh
->s
, 0);
2106 * Throttle or unthrottle _all_ local data streams (for when sends
2107 * on the SSH connection itself back up).
2109 static void ssh_throttle_all(Ssh ssh
, int enable
, int bufsize
)
2112 struct ssh_channel
*c
;
2114 if (enable
== ssh
->throttled_all
)
2116 ssh
->throttled_all
= enable
;
2117 ssh
->overall_bufsize
= bufsize
;
2120 for (i
= 0; NULL
!= (c
= index234(ssh
->channels
, i
)); i
++) {
2122 case CHAN_MAINSESSION
:
2124 * This is treated separately, outside the switch.
2128 x11_override_throttle(c
->u
.x11
.s
, enable
);
2131 /* Agent channels require no buffer management. */
2134 pfd_override_throttle(c
->u
.x11
.s
, enable
);
2141 * Username and password input, abstracted off into routines
2142 * reusable in several places - even between SSH1 and SSH2.
2145 /* Set up a username or password input loop on a given buffer. */
2146 void setup_userpass_input(Ssh ssh
, char *buffer
, int buflen
, int echo
)
2148 ssh
->userpass_input_buffer
= buffer
;
2149 ssh
->userpass_input_buflen
= buflen
;
2150 ssh
->userpass_input_bufpos
= 0;
2151 ssh
->userpass_input_echo
= echo
;
2155 * Process some terminal data in the course of username/password
2156 * input. Returns >0 for success (line of input returned in
2157 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2158 * for inconclusive (keep waiting for more input please).
2160 int process_userpass_input(Ssh ssh
, unsigned char *in
, int inlen
)
2165 switch (c
= *in
++) {
2168 ssh
->userpass_input_buffer
[ssh
->userpass_input_bufpos
] = 0;
2169 ssh
->userpass_input_buffer
[ssh
->userpass_input_buflen
-1] = 0;
2174 if (ssh
->userpass_input_bufpos
> 0) {
2175 if (ssh
->userpass_input_echo
)
2176 c_write_str(ssh
, "\b \b");
2177 ssh
->userpass_input_bufpos
--;
2182 while (ssh
->userpass_input_bufpos
> 0) {
2183 if (ssh
->userpass_input_echo
)
2184 c_write_str(ssh
, "\b \b");
2185 ssh
->userpass_input_bufpos
--;
2193 if (((c
>= ' ' && c
<= '~') ||
2194 ((unsigned char) c
>= 160))
2195 && ssh
->userpass_input_bufpos
< ssh
->userpass_input_buflen
-1) {
2196 ssh
->userpass_input_buffer
[ssh
->userpass_input_bufpos
++] = c
;
2197 if (ssh
->userpass_input_echo
)
2198 c_write(ssh
, &c
, 1);
2207 * Handle the key exchange and user authentication phases.
2209 static int do_ssh1_login(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
2212 unsigned char cookie
[8];
2213 struct RSAKey servkey
, hostkey
;
2214 struct MD5Context md5c
;
2215 struct do_ssh1_login_state
{
2217 unsigned char *rsabuf
, *keystr1
, *keystr2
;
2218 unsigned long supported_ciphers_mask
, supported_auths_mask
;
2219 int tried_publickey
, tried_agent
;
2220 int tis_auth_refused
, ccard_auth_refused
;
2221 unsigned char session_id
[16];
2224 void *publickey_blob
;
2225 int publickey_bloblen
;
2231 unsigned char request
[5], *response
, *p
;
2240 crState(do_ssh1_login_state
);
2242 crBegin(ssh
->do_ssh1_login_crstate
);
2247 if (ssh
->pktin
.type
!= SSH1_SMSG_PUBLIC_KEY
) {
2248 bombout((ssh
,"Public key packet not received"));
2252 logevent("Received public keys");
2254 memcpy(cookie
, ssh
->pktin
.body
, 8);
2256 i
= makekey(ssh
->pktin
.body
+ 8, &servkey
, &s
->keystr1
, 0);
2257 j
= makekey(ssh
->pktin
.body
+ 8 + i
, &hostkey
, &s
->keystr2
, 0);
2260 * Log the host key fingerprint.
2264 logevent("Host key fingerprint is:");
2265 strcpy(logmsg
, " ");
2266 hostkey
.comment
= NULL
;
2267 rsa_fingerprint(logmsg
+ strlen(logmsg
),
2268 sizeof(logmsg
) - strlen(logmsg
), &hostkey
);
2272 ssh
->v1_remote_protoflags
= GET_32BIT(ssh
->pktin
.body
+ 8 + i
+ j
);
2273 s
->supported_ciphers_mask
= GET_32BIT(ssh
->pktin
.body
+ 12 + i
+ j
);
2274 s
->supported_auths_mask
= GET_32BIT(ssh
->pktin
.body
+ 16 + i
+ j
);
2276 ssh
->v1_local_protoflags
=
2277 ssh
->v1_remote_protoflags
& SSH1_PROTOFLAGS_SUPPORTED
;
2278 ssh
->v1_local_protoflags
|= SSH1_PROTOFLAG_SCREEN_NUMBER
;
2281 MD5Update(&md5c
, s
->keystr2
, hostkey
.bytes
);
2282 MD5Update(&md5c
, s
->keystr1
, servkey
.bytes
);
2283 MD5Update(&md5c
, ssh
->pktin
.body
, 8);
2284 MD5Final(s
->session_id
, &md5c
);
2286 for (i
= 0; i
< 32; i
++)
2287 ssh
->session_key
[i
] = random_byte();
2289 s
->len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
2291 s
->rsabuf
= smalloc(s
->len
);
2293 fatalbox("Out of memory");
2296 * Verify the host key.
2300 * First format the key into a string.
2302 int len
= rsastr_len(&hostkey
);
2303 char fingerprint
[100];
2304 char *keystr
= smalloc(len
);
2306 fatalbox("Out of memory");
2307 rsastr_fmt(keystr
, &hostkey
);
2308 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
2309 verify_ssh_host_key(ssh
->frontend
,
2310 ssh
->savedhost
, ssh
->savedport
, "rsa", keystr
,
2315 for (i
= 0; i
< 32; i
++) {
2316 s
->rsabuf
[i
] = ssh
->session_key
[i
];
2318 s
->rsabuf
[i
] ^= s
->session_id
[i
];
2321 if (hostkey
.bytes
> servkey
.bytes
) {
2322 rsaencrypt(s
->rsabuf
, 32, &servkey
);
2323 rsaencrypt(s
->rsabuf
, servkey
.bytes
, &hostkey
);
2325 rsaencrypt(s
->rsabuf
, 32, &hostkey
);
2326 rsaencrypt(s
->rsabuf
, hostkey
.bytes
, &servkey
);
2329 logevent("Encrypted session key");
2332 int cipher_chosen
= 0, warn
= 0;
2333 char *cipher_string
= NULL
;
2335 for (i
= 0; !cipher_chosen
&& i
< CIPHER_MAX
; i
++) {
2336 int next_cipher
= cfg
.ssh_cipherlist
[i
];
2337 if (next_cipher
== CIPHER_WARN
) {
2338 /* If/when we choose a cipher, warn about it */
2340 } else if (next_cipher
== CIPHER_AES
) {
2341 /* XXX Probably don't need to mention this. */
2342 logevent("AES not supported in SSH1, skipping");
2344 switch (next_cipher
) {
2345 case CIPHER_3DES
: s
->cipher_type
= SSH_CIPHER_3DES
;
2346 cipher_string
= "3DES"; break;
2347 case CIPHER_BLOWFISH
: s
->cipher_type
= SSH_CIPHER_BLOWFISH
;
2348 cipher_string
= "Blowfish"; break;
2349 case CIPHER_DES
: s
->cipher_type
= SSH_CIPHER_DES
;
2350 cipher_string
= "single-DES"; break;
2352 if (s
->supported_ciphers_mask
& (1 << s
->cipher_type
))
2356 if (!cipher_chosen
) {
2357 if ((s
->supported_ciphers_mask
& (1 << SSH_CIPHER_3DES
)) == 0)
2358 bombout((ssh
,"Server violates SSH 1 protocol by not "
2359 "supporting 3DES encryption"));
2361 /* shouldn't happen */
2362 bombout((ssh
,"No supported ciphers found"));
2366 /* Warn about chosen cipher if necessary. */
2368 askcipher(ssh
->frontend
, cipher_string
, 0);
2371 switch (s
->cipher_type
) {
2372 case SSH_CIPHER_3DES
:
2373 logevent("Using 3DES encryption");
2375 case SSH_CIPHER_DES
:
2376 logevent("Using single-DES encryption");
2378 case SSH_CIPHER_BLOWFISH
:
2379 logevent("Using Blowfish encryption");
2383 send_packet(ssh
, SSH1_CMSG_SESSION_KEY
,
2384 PKT_CHAR
, s
->cipher_type
,
2385 PKT_DATA
, cookie
, 8,
2386 PKT_CHAR
, (s
->len
* 8) >> 8, PKT_CHAR
, (s
->len
* 8) & 0xFF,
2387 PKT_DATA
, s
->rsabuf
, s
->len
,
2388 PKT_INT
, ssh
->v1_local_protoflags
, PKT_END
);
2390 logevent("Trying to enable encryption...");
2394 ssh
->cipher
= (s
->cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
2395 s
->cipher_type
== SSH_CIPHER_DES ?
&ssh_des
:
2397 ssh
->v1_cipher_ctx
= ssh
->cipher
->make_context();
2398 ssh
->cipher
->sesskey(ssh
->v1_cipher_ctx
, ssh
->session_key
);
2401 sprintf(buf
, "Initialised %.200s encryption", ssh
->cipher
->text_name
);
2405 ssh
->crcda_ctx
= crcda_make_context();
2406 logevent("Installing CRC compensation attack detector");
2410 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2411 bombout((ssh
,"Encryption not successfully enabled"));
2415 logevent("Successfully started encryption");
2419 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
2420 if (ssh_get_line
&& !ssh_getline_pw_only
) {
2421 if (!ssh_get_line("login as: ",
2422 s
->username
, sizeof(s
->username
), FALSE
)) {
2424 * get_line failed to get a username.
2427 logevent("No username provided. Abandoning session.");
2428 ssh
->state
= SSH_STATE_CLOSED
;
2432 int ret
; /* need not be kept over crReturn */
2433 c_write_str(ssh
, "login as: ");
2436 setup_userpass_input(ssh
, s
->username
, sizeof(s
->username
), 1);
2438 crWaitUntil(!ispkt
);
2439 ret
= process_userpass_input(ssh
, in
, inlen
);
2443 c_write_str(ssh
, "\r\n");
2446 strncpy(s
->username
, cfg
.username
, sizeof(s
->username
));
2447 s
->username
[sizeof(s
->username
)-1] = '\0';
2450 send_packet(ssh
, SSH1_CMSG_USER
, PKT_STR
, s
->username
, PKT_END
);
2452 char userlog
[22 + sizeof(s
->username
)];
2453 sprintf(userlog
, "Sent username \"%s\"", s
->username
);
2455 if (flags
& FLAG_INTERACTIVE
&&
2456 (!((flags
& FLAG_STDERR
) && (flags
& FLAG_VERBOSE
)))) {
2457 strcat(userlog
, "\r\n");
2458 c_write_str(ssh
, userlog
);
2465 if ((ssh
->remote_bugs
& BUG_CHOKES_ON_RSA
)) {
2466 /* We must not attempt PK auth. Pretend we've already tried it. */
2467 s
->tried_publickey
= s
->tried_agent
= 1;
2469 s
->tried_publickey
= s
->tried_agent
= 0;
2471 s
->tis_auth_refused
= s
->ccard_auth_refused
= 0;
2472 /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
2474 if (!rsakey_pubblob(cfg
.keyfile
,
2475 &s
->publickey_blob
, &s
->publickey_bloblen
))
2476 s
->publickey_blob
= NULL
;
2478 s
->publickey_blob
= NULL
;
2480 while (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2481 s
->pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
2483 if (agent_exists() && !s
->tried_agent
) {
2485 * Attempt RSA authentication using Pageant.
2491 logevent("Pageant is running. Requesting keys.");
2493 /* Request the keys held by the agent. */
2494 PUT_32BIT(s
->request
, 1);
2495 s
->request
[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES
;
2496 agent_query(s
->request
, 5, &r
, &s
->responselen
);
2497 s
->response
= (unsigned char *) r
;
2498 if (s
->response
&& s
->responselen
>= 5 &&
2499 s
->response
[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER
) {
2500 s
->p
= s
->response
+ 5;
2501 s
->nkeys
= GET_32BIT(s
->p
);
2505 sprintf(buf
, "Pageant has %d SSH1 keys", s
->nkeys
);
2508 for (s
->keyi
= 0; s
->keyi
< s
->nkeys
; s
->keyi
++) {
2511 sprintf(buf
, "Trying Pageant key #%d", s
->keyi
);
2514 if (s
->publickey_blob
&&
2515 !memcmp(s
->p
, s
->publickey_blob
,
2516 s
->publickey_bloblen
)) {
2517 logevent("This key matches configured key file");
2518 s
->tried_publickey
= 1;
2521 s
->p
+= ssh1_read_bignum(s
->p
, &s
->key
.exponent
);
2522 s
->p
+= ssh1_read_bignum(s
->p
, &s
->key
.modulus
);
2523 s
->commentlen
= GET_32BIT(s
->p
);
2526 s
->p
+= s
->commentlen
;
2527 send_packet(ssh
, SSH1_CMSG_AUTH_RSA
,
2528 PKT_BIGNUM
, s
->key
.modulus
, PKT_END
);
2530 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2531 logevent("Key refused");
2534 logevent("Received RSA challenge");
2535 ssh1_read_bignum(ssh
->pktin
.body
, &s
->challenge
);
2537 char *agentreq
, *q
, *ret
;
2540 len
= 1 + 4; /* message type, bit count */
2541 len
+= ssh1_bignum_length(s
->key
.exponent
);
2542 len
+= ssh1_bignum_length(s
->key
.modulus
);
2543 len
+= ssh1_bignum_length(s
->challenge
);
2544 len
+= 16; /* session id */
2545 len
+= 4; /* response format */
2546 agentreq
= smalloc(4 + len
);
2547 PUT_32BIT(agentreq
, len
);
2549 *q
++ = SSH1_AGENTC_RSA_CHALLENGE
;
2550 PUT_32BIT(q
, bignum_bitcount(s
->key
.modulus
));
2552 q
+= ssh1_write_bignum(q
, s
->key
.exponent
);
2553 q
+= ssh1_write_bignum(q
, s
->key
.modulus
);
2554 q
+= ssh1_write_bignum(q
, s
->challenge
);
2555 memcpy(q
, s
->session_id
, 16);
2557 PUT_32BIT(q
, 1); /* response format */
2558 agent_query(agentreq
, len
+ 4, &vret
, &retlen
);
2562 if (ret
[4] == SSH1_AGENT_RSA_RESPONSE
) {
2563 logevent("Sending Pageant's response");
2564 send_packet(ssh
, SSH1_CMSG_AUTH_RSA_RESPONSE
,
2565 PKT_DATA
, ret
+ 5, 16,
2569 if (ssh
->pktin
.type
== SSH1_SMSG_SUCCESS
) {
2571 ("Pageant's response accepted");
2572 if (flags
& FLAG_VERBOSE
) {
2573 c_write_str(ssh
, "Authenticated using"
2575 c_write(ssh
, s
->commentp
,
2577 c_write_str(ssh
, "\" from agent\r\n");
2582 ("Pageant's response not accepted");
2585 ("Pageant failed to answer challenge");
2589 logevent("No reply received from Pageant");
2592 freebn(s
->key
.exponent
);
2593 freebn(s
->key
.modulus
);
2594 freebn(s
->challenge
);
2602 if (*cfg
.keyfile
&& !s
->tried_publickey
)
2603 s
->pwpkt_type
= SSH1_CMSG_AUTH_RSA
;
2605 if (cfg
.try_tis_auth
&&
2606 (s
->supported_auths_mask
& (1 << SSH1_AUTH_TIS
)) &&
2607 !s
->tis_auth_refused
) {
2608 s
->pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
2609 logevent("Requested TIS authentication");
2610 send_packet(ssh
, SSH1_CMSG_AUTH_TIS
, PKT_END
);
2612 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
2613 logevent("TIS authentication declined");
2614 if (flags
& FLAG_INTERACTIVE
)
2615 c_write_str(ssh
, "TIS authentication refused.\r\n");
2616 s
->tis_auth_refused
= 1;
2619 int challengelen
= GET_32BIT(ssh
->pktin
.body
);
2620 logevent("Received TIS challenge");
2621 if (challengelen
> sizeof(s
->prompt
) - 1)
2622 challengelen
= sizeof(s
->prompt
) - 1;/* prevent overrun */
2623 memcpy(s
->prompt
, ssh
->pktin
.body
+ 4, challengelen
);
2624 /* Prompt heuristic comes from OpenSSH */
2625 strncpy(s
->prompt
+ challengelen
,
2626 memchr(s
->prompt
, '\n', challengelen
) ?
2627 "": "\r\nResponse: ",
2628 (sizeof s
->prompt
) - challengelen
);
2629 s
->prompt
[(sizeof s
->prompt
) - 1] = '\0';
2632 if (cfg
.try_tis_auth
&&
2633 (s
->supported_auths_mask
& (1 << SSH1_AUTH_CCARD
)) &&
2634 !s
->ccard_auth_refused
) {
2635 s
->pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
2636 logevent("Requested CryptoCard authentication");
2637 send_packet(ssh
, SSH1_CMSG_AUTH_CCARD
, PKT_END
);
2639 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
2640 logevent("CryptoCard authentication declined");
2641 c_write_str(ssh
, "CryptoCard authentication refused.\r\n");
2642 s
->ccard_auth_refused
= 1;
2645 int challengelen
= GET_32BIT(ssh
->pktin
.body
);
2646 logevent("Received CryptoCard challenge");
2647 if (challengelen
> sizeof(s
->prompt
) - 1)
2648 challengelen
= sizeof(s
->prompt
) - 1;/* prevent overrun */
2649 memcpy(s
->prompt
, ssh
->pktin
.body
+ 4, challengelen
);
2650 strncpy(s
->prompt
+ challengelen
,
2651 memchr(s
->prompt
, '\n', challengelen
) ?
2652 "" : "\r\nResponse: ",
2653 sizeof(s
->prompt
) - challengelen
);
2654 s
->prompt
[sizeof(s
->prompt
) - 1] = '\0';
2657 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2658 sprintf(s
->prompt
, "%.90s@%.90s's password: ",
2659 s
->username
, ssh
->savedhost
);
2661 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2662 char *comment
= NULL
;
2665 if (flags
& FLAG_VERBOSE
)
2666 c_write_str(ssh
, "Trying public key authentication.\r\n");
2667 sprintf(msgbuf
, "Trying public key \"%.200s\"", cfg
.keyfile
);
2669 type
= key_type(cfg
.keyfile
);
2670 if (type
!= SSH_KEYTYPE_SSH1
) {
2671 sprintf(msgbuf
, "Key is of wrong type (%s)",
2672 key_type_to_str(type
));
2674 c_write_str(ssh
, msgbuf
);
2675 c_write_str(ssh
, "\r\n");
2676 s
->tried_publickey
= 1;
2679 if (!rsakey_encrypted(cfg
.keyfile
, &comment
)) {
2680 if (flags
& FLAG_VERBOSE
)
2681 c_write_str(ssh
, "No passphrase required.\r\n");
2684 sprintf(s
->prompt
, "Passphrase for key \"%.100s\": ", comment
);
2689 * Show password prompt, having first obtained it via a TIS
2690 * or CryptoCard exchange if we're doing TIS or CryptoCard
2694 if (!ssh_get_line(s
->prompt
, s
->password
,
2695 sizeof(s
->password
), TRUE
)) {
2697 * get_line failed to get a password (for example
2698 * because one was supplied on the command line
2699 * which has already failed to work). Terminate.
2701 send_packet(ssh
, SSH1_MSG_DISCONNECT
,
2702 PKT_STR
, "No more passwords available to try",
2704 logevent("Unable to authenticate");
2705 connection_fatal(ssh
->frontend
, "Unable to authenticate");
2706 ssh
->state
= SSH_STATE_CLOSED
;
2710 /* Prompt may have come from server. We've munged it a bit, so
2711 * we know it to be zero-terminated at least once. */
2712 int ret
; /* need not be saved over crReturn */
2713 c_write_untrusted(ssh
, s
->prompt
, strlen(s
->prompt
));
2716 setup_userpass_input(ssh
, s
->password
, sizeof(s
->password
), 0);
2718 crWaitUntil(!ispkt
);
2719 ret
= process_userpass_input(ssh
, in
, inlen
);
2723 c_write_str(ssh
, "\r\n");
2727 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2729 * Try public key authentication with the specified
2732 s
->tried_publickey
= 1;
2735 int ret
= loadrsakey(cfg
.keyfile
, &s
->key
, s
->password
);
2737 c_write_str(ssh
, "Couldn't load private key from ");
2738 c_write_str(ssh
, cfg
.keyfile
);
2739 c_write_str(ssh
, ".\r\n");
2740 continue; /* go and try password */
2743 c_write_str(ssh
, "Wrong passphrase.\r\n");
2744 s
->tried_publickey
= 0;
2745 continue; /* try again */
2750 * Send a public key attempt.
2752 send_packet(ssh
, SSH1_CMSG_AUTH_RSA
,
2753 PKT_BIGNUM
, s
->key
.modulus
, PKT_END
);
2756 if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2757 c_write_str(ssh
, "Server refused our public key.\r\n");
2758 continue; /* go and try password */
2760 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2761 bombout((ssh
,"Bizarre response to offer of public key"));
2767 unsigned char buffer
[32];
2768 Bignum challenge
, response
;
2770 ssh1_read_bignum(ssh
->pktin
.body
, &challenge
);
2771 response
= rsadecrypt(challenge
, &s
->key
);
2772 freebn(s
->key
.private_exponent
);/* burn the evidence */
2774 for (i
= 0; i
< 32; i
++) {
2775 buffer
[i
] = bignum_byte(response
, 31 - i
);
2779 MD5Update(&md5c
, buffer
, 32);
2780 MD5Update(&md5c
, s
->session_id
, 16);
2781 MD5Final(buffer
, &md5c
);
2783 send_packet(ssh
, SSH1_CMSG_AUTH_RSA_RESPONSE
,
2784 PKT_DATA
, buffer
, 16, PKT_END
);
2791 if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2792 if (flags
& FLAG_VERBOSE
)
2793 c_write_str(ssh
, "Failed to authenticate with"
2794 " our public key.\r\n");
2795 continue; /* go and try password */
2796 } else if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2797 bombout((ssh
,"Bizarre response to RSA authentication response"));
2801 break; /* we're through! */
2803 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2805 * Defence against traffic analysis: we send a
2806 * whole bunch of packets containing strings of
2807 * different lengths. One of these strings is the
2808 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2809 * The others are all random data in
2810 * SSH1_MSG_IGNORE packets. This way a passive
2811 * listener can't tell which is the password, and
2812 * hence can't deduce the password length.
2814 * Anybody with a password length greater than 16
2815 * bytes is going to have enough entropy in their
2816 * password that a listener won't find it _that_
2817 * much help to know how long it is. So what we'll
2820 * - if password length < 16, we send 15 packets
2821 * containing string lengths 1 through 15
2823 * - otherwise, we let N be the nearest multiple
2824 * of 8 below the password length, and send 8
2825 * packets containing string lengths N through
2826 * N+7. This won't obscure the order of
2827 * magnitude of the password length, but it will
2828 * introduce a bit of extra uncertainty.
2830 * A few servers (the old 1.2.18 through 1.2.22)
2831 * can't deal with SSH1_MSG_IGNORE. For these
2832 * servers, we need an alternative defence. We make
2833 * use of the fact that the password is interpreted
2834 * as a C string: so we can append a NUL, then some
2837 * One server (a Cisco one) can deal with neither
2838 * SSH1_MSG_IGNORE _nor_ a padded password string.
2839 * For this server we are left with no defences
2840 * against password length sniffing.
2842 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
)) {
2844 * The server can deal with SSH1_MSG_IGNORE, so
2845 * we can use the primary defence.
2847 int bottom
, top
, pwlen
, i
;
2850 pwlen
= strlen(s
->password
);
2852 bottom
= 0; /* zero length passwords are OK! :-) */
2855 bottom
= pwlen
& ~7;
2859 assert(pwlen
>= bottom
&& pwlen
<= top
);
2861 randomstr
= smalloc(top
+ 1);
2863 for (i
= bottom
; i
<= top
; i
++) {
2865 defer_packet(ssh
, s
->pwpkt_type
,
2866 PKT_STR
, s
->password
, PKT_END
);
2868 for (j
= 0; j
< i
; j
++) {
2870 randomstr
[j
] = random_byte();
2871 } while (randomstr
[j
] == '\0');
2873 randomstr
[i
] = '\0';
2874 defer_packet(ssh
, SSH1_MSG_IGNORE
,
2875 PKT_STR
, randomstr
, PKT_END
);
2878 logevent("Sending password with camouflage packets");
2879 ssh_pkt_defersend(ssh
);
2881 else if (!(ssh
->remote_bugs
& BUG_NEEDS_SSH1_PLAIN_PASSWORD
)) {
2883 * The server can't deal with SSH1_MSG_IGNORE
2884 * but can deal with padded passwords, so we
2885 * can use the secondary defence.
2891 len
= strlen(s
->password
);
2892 if (len
< sizeof(string
)) {
2894 strcpy(string
, s
->password
);
2895 len
++; /* cover the zero byte */
2896 while (len
< sizeof(string
)) {
2897 string
[len
++] = (char) random_byte();
2902 logevent("Sending length-padded password");
2903 send_packet(ssh
, s
->pwpkt_type
, PKT_INT
, len
,
2904 PKT_DATA
, ss
, len
, PKT_END
);
2907 * The server has _both_
2908 * BUG_CHOKES_ON_SSH1_IGNORE and
2909 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2910 * therefore nothing we can do.
2913 len
= strlen(s
->password
);
2914 logevent("Sending unpadded password");
2915 send_packet(ssh
, s
->pwpkt_type
, PKT_INT
, len
,
2916 PKT_DATA
, s
->password
, len
, PKT_END
);
2919 send_packet(ssh
, s
->pwpkt_type
, PKT_STR
, s
->password
, PKT_END
);
2922 logevent("Sent password");
2923 memset(s
->password
, 0, strlen(s
->password
));
2925 if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2926 if (flags
& FLAG_VERBOSE
)
2927 c_write_str(ssh
, "Access denied\r\n");
2928 logevent("Authentication refused");
2929 } else if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2930 bombout((ssh
,"Strange packet received, type %d", ssh
->pktin
.type
));
2935 logevent("Authentication successful");
2940 void sshfwd_close(struct ssh_channel
*c
)
2944 if (c
&& !c
->closes
) {
2946 * If the channel's remoteid is -1, we have sent
2947 * CHANNEL_OPEN for this channel, but it hasn't even been
2948 * acknowledged by the server. So we must set a close flag
2949 * on it now, and then when the server acks the channel
2950 * open, we can close it then.
2952 if (((int)c
->remoteid
) != -1) {
2953 if (ssh
->version
== 1) {
2954 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
2957 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_CLOSE
);
2958 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
2962 c
->closes
= 1; /* sent MSG_CLOSE */
2963 if (c
->type
== CHAN_X11
) {
2965 logevent("Forwarded X11 connection terminated");
2966 } else if (c
->type
== CHAN_SOCKDATA
||
2967 c
->type
== CHAN_SOCKDATA_DORMANT
) {
2969 logevent("Forwarded port closed");
2974 int sshfwd_write(struct ssh_channel
*c
, char *buf
, int len
)
2978 if (ssh
->version
== 1) {
2979 send_packet(ssh
, SSH1_MSG_CHANNEL_DATA
,
2980 PKT_INT
, c
->remoteid
,
2981 PKT_INT
, len
, PKT_DATA
, buf
, len
, PKT_END
);
2983 * In SSH1 we can return 0 here - implying that forwarded
2984 * connections are never individually throttled - because
2985 * the only circumstance that can cause throttling will be
2986 * the whole SSH connection backing up, in which case
2987 * _everything_ will be throttled as a whole.
2991 ssh2_add_channel_data(c
, buf
, len
);
2992 return ssh2_try_send(c
);
2996 void sshfwd_unthrottle(struct ssh_channel
*c
, int bufsize
)
3000 if (ssh
->version
== 1) {
3001 if (c
->v
.v1
.throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
3002 c
->v
.v1
.throttling
= 0;
3003 ssh1_throttle(ssh
, -1);
3006 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
3010 static void ssh1_protocol(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
3012 crBegin(ssh
->ssh1_protocol_crstate
);
3016 while (!do_ssh1_login(ssh
, in
, inlen
, ispkt
)) {
3019 if (ssh
->state
== SSH_STATE_CLOSED
)
3022 if (cfg
.agentfwd
&& agent_exists()) {
3023 logevent("Requesting agent forwarding");
3024 send_packet(ssh
, SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
3028 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3029 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3030 bombout((ssh
,"Protocol confusion"));
3032 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3033 logevent("Agent forwarding refused");
3035 logevent("Agent forwarding enabled");
3036 ssh
->agentfwd_enabled
= TRUE
;
3040 if (cfg
.x11_forward
) {
3041 char proto
[20], data
[64];
3042 logevent("Requesting X11 forwarding");
3043 ssh
->x11auth
= x11_invent_auth(proto
, sizeof(proto
),
3044 data
, sizeof(data
));
3045 if (ssh
->v1_local_protoflags
& SSH1_PROTOFLAG_SCREEN_NUMBER
) {
3046 send_packet(ssh
, SSH1_CMSG_X11_REQUEST_FORWARDING
,
3047 PKT_STR
, proto
, PKT_STR
, data
,
3048 PKT_INT
, 0, PKT_END
);
3050 send_packet(ssh
, SSH1_CMSG_X11_REQUEST_FORWARDING
,
3051 PKT_STR
, proto
, PKT_STR
, data
, PKT_END
);
3056 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3057 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3058 bombout((ssh
,"Protocol confusion"));
3060 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3061 logevent("X11 forwarding refused");
3063 logevent("X11 forwarding enabled");
3064 ssh
->X11_fwd_enabled
= TRUE
;
3071 int sport
,dport
,sserv
,dserv
;
3072 char sports
[256], dports
[256], host
[256];
3075 ssh
->rportfwds
= newtree234(ssh_rportcmp_ssh1
);
3076 /* Add port forwardings. */
3077 ssh
->portfwd_strptr
= cfg
.portfwd
;
3078 while (*ssh
->portfwd_strptr
) {
3079 type
= *ssh
->portfwd_strptr
++;
3081 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= '\t')
3082 sports
[n
++] = *ssh
->portfwd_strptr
++;
3084 if (*ssh
->portfwd_strptr
== '\t')
3085 ssh
->portfwd_strptr
++;
3087 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= ':')
3088 host
[n
++] = *ssh
->portfwd_strptr
++;
3090 if (*ssh
->portfwd_strptr
== ':')
3091 ssh
->portfwd_strptr
++;
3093 while (*ssh
->portfwd_strptr
)
3094 dports
[n
++] = *ssh
->portfwd_strptr
++;
3096 ssh
->portfwd_strptr
++;
3097 dport
= atoi(dports
);
3101 dport
= net_service_lookup(dports
);
3104 "Service lookup failed for destination port \"%s\"",
3109 sport
= atoi(sports
);
3113 sport
= net_service_lookup(sports
);
3116 "Service lookup failed for source port \"%s\"",
3121 if (sport
&& dport
) {
3123 pfd_addforward(host
, dport
, sport
, ssh
);
3124 sprintf(buf
, "Local port %.*s%.*s%d%.*s forwarding to"
3125 " %s:%.*s%.*s%d%.*s",
3126 (int)(sserv ?
strlen(sports
) : 0), sports
,
3127 sserv
, "(", sport
, sserv
, ")",
3129 (int)(dserv ?
strlen(dports
) : 0), dports
,
3130 dserv
, "(", dport
, dserv
, ")");
3133 struct ssh_rportfwd
*pf
;
3134 pf
= smalloc(sizeof(*pf
));
3135 strcpy(pf
->dhost
, host
);
3137 if (add234(ssh
->rportfwds
, pf
) != pf
) {
3139 "Duplicate remote port forwarding to %s:%d",
3144 sprintf(buf
, "Requesting remote port %.*s%.*s%d%.*s"
3145 " forward to %s:%.*s%.*s%d%.*s",
3146 (int)(sserv ?
strlen(sports
) : 0), sports
,
3147 sserv
, "(", sport
, sserv
, ")",
3149 (int)(dserv ?
strlen(dports
) : 0), dports
,
3150 dserv
, "(", dport
, dserv
, ")");
3152 send_packet(ssh
, SSH1_CMSG_PORT_FORWARD_REQUEST
,
3160 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3161 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3162 bombout((ssh
,"Protocol confusion"));
3164 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3165 c_write_str(ssh
, "Server refused port"
3168 logevent("Remote port forwarding enabled");
3176 send_packet(ssh
, SSH1_CMSG_REQUEST_PTY
,
3177 PKT_STR
, cfg
.termtype
,
3178 PKT_INT
, ssh
->term_height
,
3179 PKT_INT
, ssh
->term_width
,
3180 PKT_INT
, 0, PKT_INT
, 0, PKT_CHAR
, 0, PKT_END
);
3181 ssh
->state
= SSH_STATE_INTERMED
;
3185 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3186 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3187 bombout((ssh
,"Protocol confusion"));
3189 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3190 c_write_str(ssh
, "Server refused to allocate pty\r\n");
3191 ssh
->editing
= ssh
->echoing
= 1;
3193 logevent("Allocated pty");
3195 ssh
->editing
= ssh
->echoing
= 1;
3198 if (cfg
.compression
) {
3199 send_packet(ssh
, SSH1_CMSG_REQUEST_COMPRESSION
, PKT_INT
, 6, PKT_END
);
3203 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3204 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3205 bombout((ssh
,"Protocol confusion"));
3207 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3208 c_write_str(ssh
, "Server refused to compress\r\n");
3210 logevent("Started compression");
3211 ssh
->v1_compressing
= TRUE
;
3212 ssh
->cs_comp_ctx
= zlib_compress_init();
3213 logevent("Initialised zlib (RFC1950) compression");
3214 ssh
->sc_comp_ctx
= zlib_decompress_init();
3215 logevent("Initialised zlib (RFC1950) decompression");
3219 * Start the shell or command.
3221 * Special case: if the first-choice command is an SSH2
3222 * subsystem (hence not usable here) and the second choice
3223 * exists, we fall straight back to that.
3226 char *cmd
= cfg
.remote_cmd_ptr
;
3228 if (cfg
.ssh_subsys
&& cfg
.remote_cmd_ptr2
) {
3229 cmd
= cfg
.remote_cmd_ptr2
;
3230 ssh
->fallback_cmd
= TRUE
;
3233 send_packet(ssh
, SSH1_CMSG_EXEC_CMD
, PKT_STR
, cmd
, PKT_END
);
3235 send_packet(ssh
, SSH1_CMSG_EXEC_SHELL
, PKT_END
);
3236 logevent("Started session");
3239 ssh
->state
= SSH_STATE_SESSION
;
3240 if (ssh
->size_needed
)
3241 ssh_size(ssh
, ssh
->term_width
, ssh
->term_height
);
3242 if (ssh
->eof_needed
)
3243 ssh_special(ssh
, TS_EOF
);
3246 ldisc_send(ssh
->ldisc
, NULL
, 0, 0);/* cause ldisc to notice changes */
3248 ssh
->channels
= newtree234(ssh_channelcmp
);
3252 if (ssh
->pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
3253 ssh
->pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
3254 long len
= GET_32BIT(ssh
->pktin
.body
);
3256 from_backend(ssh
->frontend
,
3257 ssh
->pktin
.type
== SSH1_SMSG_STDERR_DATA
,
3258 ssh
->pktin
.body
+ 4, len
);
3259 if (!ssh
->v1_stdout_throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
3260 ssh
->v1_stdout_throttling
= 1;
3261 ssh1_throttle(ssh
, +1);
3263 } else if (ssh
->pktin
.type
== SSH1_MSG_DISCONNECT
) {
3264 ssh
->state
= SSH_STATE_CLOSED
;
3265 logevent("Received disconnect request");
3267 } else if (ssh
->pktin
.type
== SSH1_SMSG_X11_OPEN
) {
3268 /* Remote side is trying to open a channel to talk to our
3269 * X-Server. Give them back a local channel number. */
3270 struct ssh_channel
*c
;
3272 logevent("Received X11 connect request");
3273 /* Refuse if X11 forwarding is disabled. */
3274 if (!ssh
->X11_fwd_enabled
) {
3275 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3276 PKT_INT
, GET_32BIT(ssh
->pktin
.body
), PKT_END
);
3277 logevent("Rejected X11 connect request");
3279 c
= smalloc(sizeof(struct ssh_channel
));
3282 if (x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
,
3283 ssh
->x11auth
) != NULL
) {
3284 logevent("opening X11 forward connection failed");
3286 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3287 PKT_INT
, GET_32BIT(ssh
->pktin
.body
),
3291 ("opening X11 forward connection succeeded");
3292 c
->remoteid
= GET_32BIT(ssh
->pktin
.body
);
3293 c
->localid
= alloc_channel_id(ssh
);
3295 c
->v
.v1
.throttling
= 0;
3296 c
->type
= CHAN_X11
; /* identify channel type */
3297 add234(ssh
->channels
, c
);
3298 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3299 PKT_INT
, c
->remoteid
, PKT_INT
,
3300 c
->localid
, PKT_END
);
3301 logevent("Opened X11 forward channel");
3304 } else if (ssh
->pktin
.type
== SSH1_SMSG_AGENT_OPEN
) {
3305 /* Remote side is trying to open a channel to talk to our
3306 * agent. Give them back a local channel number. */
3307 struct ssh_channel
*c
;
3309 /* Refuse if agent forwarding is disabled. */
3310 if (!ssh
->agentfwd_enabled
) {
3311 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3312 PKT_INT
, GET_32BIT(ssh
->pktin
.body
), PKT_END
);
3314 c
= smalloc(sizeof(struct ssh_channel
));
3316 c
->remoteid
= GET_32BIT(ssh
->pktin
.body
);
3317 c
->localid
= alloc_channel_id(ssh
);
3319 c
->v
.v1
.throttling
= 0;
3320 c
->type
= CHAN_AGENT
; /* identify channel type */
3321 c
->u
.a
.lensofar
= 0;
3322 add234(ssh
->channels
, c
);
3323 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3324 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
3327 } else if (ssh
->pktin
.type
== SSH1_MSG_PORT_OPEN
) {
3328 /* Remote side is trying to open a channel to talk to a
3329 * forwarded port. Give them back a local channel number. */
3330 struct ssh_channel
*c
;
3331 struct ssh_rportfwd pf
;
3333 char host
[256], buf
[1024];
3335 c
= smalloc(sizeof(struct ssh_channel
));
3338 hostsize
= GET_32BIT(ssh
->pktin
.body
+4);
3339 for(h
= host
, p
= ssh
->pktin
.body
+8; hostsize
!= 0; hostsize
--) {
3340 if (h
+1 < host
+sizeof(host
))
3345 port
= GET_32BIT(p
);
3347 strcpy(pf
.dhost
, host
);
3350 if (find234(ssh
->rportfwds
, &pf
, NULL
) == NULL
) {
3351 sprintf(buf
, "Rejected remote port open request for %s:%d",
3354 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3355 PKT_INT
, GET_32BIT(ssh
->pktin
.body
), PKT_END
);
3357 sprintf(buf
, "Received remote port open request for %s:%d",
3360 e
= pfd_newconnect(&c
->u
.pfd
.s
, host
, port
, c
);
3363 sprintf(buf
, "Port open failed: %s", e
);
3366 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3367 PKT_INT
, GET_32BIT(ssh
->pktin
.body
),
3370 c
->remoteid
= GET_32BIT(ssh
->pktin
.body
);
3371 c
->localid
= alloc_channel_id(ssh
);
3373 c
->v
.v1
.throttling
= 0;
3374 c
->type
= CHAN_SOCKDATA
; /* identify channel type */
3375 add234(ssh
->channels
, c
);
3376 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3377 PKT_INT
, c
->remoteid
, PKT_INT
,
3378 c
->localid
, PKT_END
);
3379 logevent("Forwarded port opened successfully");
3383 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
) {
3384 unsigned int remoteid
= GET_32BIT(ssh
->pktin
.body
);
3385 unsigned int localid
= GET_32BIT(ssh
->pktin
.body
+4);
3386 struct ssh_channel
*c
;
3388 c
= find234(ssh
->channels
, &remoteid
, ssh_channelfind
);
3389 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
3390 c
->remoteid
= localid
;
3391 c
->type
= CHAN_SOCKDATA
;
3392 c
->v
.v1
.throttling
= 0;
3393 pfd_confirm(c
->u
.pfd
.s
);
3396 if (c
&& c
->closes
) {
3398 * We have a pending close on this channel,
3399 * which we decided on before the server acked
3400 * the channel open. So now we know the
3401 * remoteid, we can close it again.
3403 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE
,
3404 PKT_INT
, c
->remoteid
, PKT_END
);
3407 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_OPEN_FAILURE
) {
3408 unsigned int remoteid
= GET_32BIT(ssh
->pktin
.body
);
3409 struct ssh_channel
*c
;
3411 c
= find234(ssh
->channels
, &remoteid
, ssh_channelfind
);
3412 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
3413 logevent("Forwarded connection refused by server");
3414 pfd_close(c
->u
.pfd
.s
);
3415 del234(ssh
->channels
, c
);
3419 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE
||
3420 ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
) {
3421 /* Remote side closes a channel. */
3422 unsigned i
= GET_32BIT(ssh
->pktin
.body
);
3423 struct ssh_channel
*c
;
3424 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
3425 if (c
&& ((int)c
->remoteid
) != -1) {
3428 (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
1 : 2);
3430 if ((c
->closes
== 0) && (c
->type
== CHAN_X11
)) {
3431 logevent("Forwarded X11 connection terminated");
3432 assert(c
->u
.x11
.s
!= NULL
);
3433 x11_close(c
->u
.x11
.s
);
3436 if ((c
->closes
== 0) && (c
->type
== CHAN_SOCKDATA
)) {
3437 logevent("Forwarded port closed");
3438 assert(c
->u
.pfd
.s
!= NULL
);
3439 pfd_close(c
->u
.pfd
.s
);
3443 c
->closes
|= (closetype
<< 2); /* seen this message */
3444 if (!(c
->closes
& closetype
)) {
3445 send_packet(ssh
, ssh
->pktin
.type
, PKT_INT
, c
->remoteid
,
3447 c
->closes
|= closetype
; /* sent it too */
3450 if (c
->closes
== 15) {
3451 del234(ssh
->channels
, c
);
3455 bombout((ssh
,"Received CHANNEL_CLOSE%s for %s channel %d\n",
3456 ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
"" :
3457 "_CONFIRMATION", c ?
"half-open" : "nonexistent",
3460 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_DATA
) {
3461 /* Data sent down one of our channels. */
3462 int i
= GET_32BIT(ssh
->pktin
.body
);
3463 int len
= GET_32BIT(ssh
->pktin
.body
+ 4);
3464 unsigned char *p
= ssh
->pktin
.body
+ 8;
3465 struct ssh_channel
*c
;
3466 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
3471 bufsize
= x11_send(c
->u
.x11
.s
, p
, len
);
3474 bufsize
= pfd_send(c
->u
.pfd
.s
, p
, len
);
3477 /* Data for an agent message. Buffer it. */
3479 if (c
->u
.a
.lensofar
< 4) {
3480 int l
= min(4 - c
->u
.a
.lensofar
, len
);
3481 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
,
3485 c
->u
.a
.lensofar
+= l
;
3487 if (c
->u
.a
.lensofar
== 4) {
3489 4 + GET_32BIT(c
->u
.a
.msglen
);
3490 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
3491 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
3493 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
3495 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
3497 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
,
3501 c
->u
.a
.lensofar
+= l
;
3503 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
3504 void *reply
, *sentreply
;
3506 agent_query(c
->u
.a
.message
,
3507 c
->u
.a
.totallen
, &reply
,
3512 /* Fake SSH_AGENT_FAILURE. */
3513 sentreply
= "\0\0\0\1\5";
3516 send_packet(ssh
, SSH1_MSG_CHANNEL_DATA
,
3517 PKT_INT
, c
->remoteid
,
3519 PKT_DATA
, sentreply
, replylen
,
3523 sfree(c
->u
.a
.message
);
3524 c
->u
.a
.lensofar
= 0;
3527 bufsize
= 0; /* agent channels never back up */
3530 if (!c
->v
.v1
.throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
3531 c
->v
.v1
.throttling
= 1;
3532 ssh1_throttle(ssh
, +1);
3535 } else if (ssh
->pktin
.type
== SSH1_SMSG_SUCCESS
) {
3536 /* may be from EXEC_SHELL on some servers */
3537 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3538 /* may be from EXEC_SHELL on some servers
3539 * if no pty is available or in other odd cases. Ignore */
3540 } else if (ssh
->pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
3542 ssh
->exitcode
= GET_32BIT(ssh
->pktin
.body
);
3543 sprintf(buf
, "Server sent command exit status %d",
3546 send_packet(ssh
, SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
3548 * In case `helpful' firewalls or proxies tack
3549 * extra human-readable text on the end of the
3550 * session which we might mistake for another
3551 * encrypted packet, we close the session once
3552 * we've sent EXIT_CONFIRMATION.
3554 ssh
->state
= SSH_STATE_CLOSED
;
3557 bombout((ssh
,"Strange packet received: type %d", ssh
->pktin
.type
));
3562 int len
= min(inlen
, 512);
3563 send_packet(ssh
, SSH1_CMSG_STDIN_DATA
,
3564 PKT_INT
, len
, PKT_DATA
, in
, len
, PKT_END
);
3575 * Utility routine for decoding comma-separated strings in KEXINIT.
3577 static int in_commasep_string(char *needle
, char *haystack
, int haylen
)
3579 int needlen
= strlen(needle
);
3582 * Is it at the start of the string?
3584 if (haylen
>= needlen
&& /* haystack is long enough */
3585 !memcmp(needle
, haystack
, needlen
) && /* initial match */
3586 (haylen
== needlen
|| haystack
[needlen
] == ',')
3587 /* either , or EOS follows */
3591 * If not, search for the next comma and resume after that.
3592 * If no comma found, terminate.
3594 while (haylen
> 0 && *haystack
!= ',')
3595 haylen
--, haystack
++;
3598 haylen
--, haystack
++; /* skip over comma itself */
3603 * SSH2 key creation method.
3605 static void ssh2_mkkey(Ssh ssh
, Bignum K
, char *H
, char *sessid
, char chr
,
3609 /* First 20 bytes. */
3611 if (!(ssh
->remote_bugs
& BUG_SSH2_DERIVEKEY
))
3613 SHA_Bytes(&s
, H
, 20);
3614 SHA_Bytes(&s
, &chr
, 1);
3615 SHA_Bytes(&s
, sessid
, 20);
3616 SHA_Final(&s
, keyspace
);
3617 /* Next 20 bytes. */
3619 if (!(ssh
->remote_bugs
& BUG_SSH2_DERIVEKEY
))
3621 SHA_Bytes(&s
, H
, 20);
3622 SHA_Bytes(&s
, keyspace
, 20);
3623 SHA_Final(&s
, keyspace
+ 20);
3627 * Handle the SSH2 transport layer.
3629 static int do_ssh2_transport(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
3631 struct do_ssh2_transport_state
{
3632 int nbits
, pbits
, warn
;
3633 Bignum p
, g
, e
, f
, K
;
3634 int kex_init_value
, kex_reply_value
;
3635 const struct ssh_mac
**maclist
;
3637 const struct ssh2_cipher
*cscipher_tobe
;
3638 const struct ssh2_cipher
*sccipher_tobe
;
3639 const struct ssh_mac
*csmac_tobe
;
3640 const struct ssh_mac
*scmac_tobe
;
3641 const struct ssh_compress
*cscomp_tobe
;
3642 const struct ssh_compress
*sccomp_tobe
;
3643 char *hostkeydata
, *sigdata
, *keystr
, *fingerprint
;
3644 int hostkeylen
, siglen
;
3645 void *hkey
; /* actual host key */
3646 unsigned char exchange_hash
[20];
3647 int n_preferred_ciphers
;
3648 const struct ssh2_ciphers
*preferred_ciphers
[CIPHER_MAX
];
3649 const struct ssh_compress
*preferred_comp
;
3652 crState(do_ssh2_transport_state
);
3654 crBegin(ssh
->do_ssh2_transport_crstate
);
3656 s
->cscipher_tobe
= s
->sccipher_tobe
= NULL
;
3657 s
->csmac_tobe
= s
->scmac_tobe
= NULL
;
3658 s
->cscomp_tobe
= s
->sccomp_tobe
= NULL
;
3666 * Set up the preferred ciphers. (NULL => warn below here)
3668 s
->n_preferred_ciphers
= 0;
3669 for (i
= 0; i
< CIPHER_MAX
; i
++) {
3670 switch (cfg
.ssh_cipherlist
[i
]) {
3671 case CIPHER_BLOWFISH
:
3672 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_blowfish
;
3675 if (cfg
.ssh2_des_cbc
) {
3676 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_des
;
3680 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_3des
;
3683 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_aes
;
3686 /* Flag for later. Don't bother if it's the last in
3688 if (i
< CIPHER_MAX
- 1) {
3689 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = NULL
;
3697 * Set up preferred compression.
3699 if (cfg
.compression
)
3700 s
->preferred_comp
= &ssh_zlib
;
3702 s
->preferred_comp
= &ssh_comp_none
;
3705 * Be prepared to work around the buggy MAC problem.
3707 if (ssh
->remote_bugs
& BUG_SSH2_HMAC
)
3708 s
->maclist
= buggymacs
, s
->nmacs
= lenof(buggymacs
);
3710 s
->maclist
= macs
, s
->nmacs
= lenof(macs
);
3714 int i
, j
, cipherstr_started
;
3717 * Construct and send our key exchange packet.
3719 ssh2_pkt_init(ssh
, SSH2_MSG_KEXINIT
);
3720 for (i
= 0; i
< 16; i
++)
3721 ssh2_pkt_addbyte(ssh
, (unsigned char) random_byte());
3722 /* List key exchange algorithms. */
3723 ssh2_pkt_addstring_start(ssh
);
3724 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3725 if (kex_algs
[i
] == &ssh_diffiehellman_gex
&&
3726 (ssh
->remote_bugs
& BUG_SSH2_DH_GEX
))
3728 ssh2_pkt_addstring_str(ssh
, kex_algs
[i
]->name
);
3729 if (i
< lenof(kex_algs
) - 1)
3730 ssh2_pkt_addstring_str(ssh
, ",");
3732 /* List server host key algorithms. */
3733 ssh2_pkt_addstring_start(ssh
);
3734 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3735 ssh2_pkt_addstring_str(ssh
, hostkey_algs
[i
]->name
);
3736 if (i
< lenof(hostkey_algs
) - 1)
3737 ssh2_pkt_addstring_str(ssh
, ",");
3739 /* List client->server encryption algorithms. */
3740 ssh2_pkt_addstring_start(ssh
);
3741 cipherstr_started
= 0;
3742 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
3743 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
3744 if (!c
) continue; /* warning flag */
3745 for (j
= 0; j
< c
->nciphers
; j
++) {
3746 if (cipherstr_started
)
3747 ssh2_pkt_addstring_str(ssh
, ",");
3748 ssh2_pkt_addstring_str(ssh
, c
->list
[j
]->name
);
3749 cipherstr_started
= 1;
3752 /* List server->client 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 client->server MAC algorithms. */
3766 ssh2_pkt_addstring_start(ssh
);
3767 for (i
= 0; i
< s
->nmacs
; i
++) {
3768 ssh2_pkt_addstring_str(ssh
, s
->maclist
[i
]->name
);
3769 if (i
< s
->nmacs
- 1)
3770 ssh2_pkt_addstring_str(ssh
, ",");
3772 /* List server->client MAC algorithms. */
3773 ssh2_pkt_addstring_start(ssh
);
3774 for (i
= 0; i
< s
->nmacs
; i
++) {
3775 ssh2_pkt_addstring_str(ssh
, s
->maclist
[i
]->name
);
3776 if (i
< s
->nmacs
- 1)
3777 ssh2_pkt_addstring_str(ssh
, ",");
3779 /* List client->server compression algorithms. */
3780 ssh2_pkt_addstring_start(ssh
);
3781 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3782 const struct ssh_compress
*c
=
3783 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
3784 ssh2_pkt_addstring_str(ssh
, c
->name
);
3785 if (i
< lenof(compressions
))
3786 ssh2_pkt_addstring_str(ssh
, ",");
3788 /* List server->client compression algorithms. */
3789 ssh2_pkt_addstring_start(ssh
);
3790 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3791 const struct ssh_compress
*c
=
3792 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
3793 ssh2_pkt_addstring_str(ssh
, c
->name
);
3794 if (i
< lenof(compressions
))
3795 ssh2_pkt_addstring_str(ssh
, ",");
3797 /* List client->server languages. Empty list. */
3798 ssh2_pkt_addstring_start(ssh
);
3799 /* List server->client languages. Empty list. */
3800 ssh2_pkt_addstring_start(ssh
);
3801 /* First KEX packet does _not_ follow, because we're not that brave. */
3802 ssh2_pkt_addbool(ssh
, FALSE
);
3804 ssh2_pkt_adduint32(ssh
, 0);
3807 ssh
->exhash
= ssh
->exhashbase
;
3808 sha_string(&ssh
->exhash
, ssh
->pktout
.data
+ 5, ssh
->pktout
.length
- 5);
3814 sha_string(&ssh
->exhash
, ssh
->pktin
.data
+ 5, ssh
->pktin
.length
- 5);
3817 * Now examine the other side's KEXINIT to see what we're up
3824 if (ssh
->pktin
.type
!= SSH2_MSG_KEXINIT
) {
3825 bombout((ssh
,"expected key exchange packet from server"));
3829 ssh
->hostkey
= NULL
;
3830 s
->cscipher_tobe
= NULL
;
3831 s
->sccipher_tobe
= NULL
;
3832 s
->csmac_tobe
= NULL
;
3833 s
->scmac_tobe
= NULL
;
3834 s
->cscomp_tobe
= NULL
;
3835 s
->sccomp_tobe
= NULL
;
3836 ssh
->pktin
.savedpos
+= 16; /* skip garbage cookie */
3837 ssh2_pkt_getstring(ssh
, &str
, &len
); /* key exchange algorithms */
3838 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3839 if (kex_algs
[i
] == &ssh_diffiehellman_gex
&&
3840 (ssh
->remote_bugs
& BUG_SSH2_DH_GEX
))
3842 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
3843 ssh
->kex
= kex_algs
[i
];
3847 ssh2_pkt_getstring(ssh
, &str
, &len
); /* host key algorithms */
3848 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3849 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
3850 ssh
->hostkey
= hostkey_algs
[i
];
3854 ssh2_pkt_getstring(ssh
, &str
, &len
); /* client->server cipher */
3856 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
3857 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
3861 for (j
= 0; j
< c
->nciphers
; j
++) {
3862 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3863 s
->cscipher_tobe
= c
->list
[j
];
3868 if (s
->cscipher_tobe
) {
3870 askcipher(ssh
->frontend
, s
->cscipher_tobe
->name
, 1);
3874 if (!s
->cscipher_tobe
) {
3875 bombout((ssh
,"Couldn't agree a client-to-server cipher (available: %s)", str
));
3879 ssh2_pkt_getstring(ssh
, &str
, &len
); /* server->client cipher */
3881 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
3882 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
3886 for (j
= 0; j
< c
->nciphers
; j
++) {
3887 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3888 s
->sccipher_tobe
= c
->list
[j
];
3893 if (s
->sccipher_tobe
) {
3895 askcipher(ssh
->frontend
, s
->sccipher_tobe
->name
, 2);
3899 if (!s
->sccipher_tobe
) {
3900 bombout((ssh
,"Couldn't agree a server-to-client cipher (available: %s)", str
));
3904 ssh2_pkt_getstring(ssh
, &str
, &len
); /* client->server mac */
3905 for (i
= 0; i
< s
->nmacs
; i
++) {
3906 if (in_commasep_string(s
->maclist
[i
]->name
, str
, len
)) {
3907 s
->csmac_tobe
= s
->maclist
[i
];
3911 ssh2_pkt_getstring(ssh
, &str
, &len
); /* server->client mac */
3912 for (i
= 0; i
< s
->nmacs
; i
++) {
3913 if (in_commasep_string(s
->maclist
[i
]->name
, str
, len
)) {
3914 s
->scmac_tobe
= s
->maclist
[i
];
3918 ssh2_pkt_getstring(ssh
, &str
, &len
); /* client->server compression */
3919 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3920 const struct ssh_compress
*c
=
3921 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
3922 if (in_commasep_string(c
->name
, str
, len
)) {
3927 ssh2_pkt_getstring(ssh
, &str
, &len
); /* server->client compression */
3928 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3929 const struct ssh_compress
*c
=
3930 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
3931 if (in_commasep_string(c
->name
, str
, len
)) {
3939 * Work out the number of bits of key we will need from the key
3940 * exchange. We start with the maximum key length of either
3946 csbits
= s
->cscipher_tobe
->keylen
;
3947 scbits
= s
->sccipher_tobe
->keylen
;
3948 s
->nbits
= (csbits
> scbits ? csbits
: scbits
);
3950 /* The keys only have 160-bit entropy, since they're based on
3951 * a SHA-1 hash. So cap the key size at 160 bits. */
3956 * If we're doing Diffie-Hellman group exchange, start by
3957 * requesting a group.
3959 if (ssh
->kex
== &ssh_diffiehellman_gex
) {
3960 logevent("Doing Diffie-Hellman group exchange");
3961 ssh
->pkt_ctx
|= SSH2_PKTCTX_DHGEX
;
3963 * Work out how big a DH group we will need to allow that
3966 s
->pbits
= 512 << ((s
->nbits
- 1) / 64);
3967 ssh2_pkt_init(ssh
, SSH2_MSG_KEX_DH_GEX_REQUEST
);
3968 ssh2_pkt_adduint32(ssh
, s
->pbits
);
3972 if (ssh
->pktin
.type
!= SSH2_MSG_KEX_DH_GEX_GROUP
) {
3973 bombout((ssh
,"expected key exchange group packet from server"));
3976 s
->p
= ssh2_pkt_getmp(ssh
);
3977 s
->g
= ssh2_pkt_getmp(ssh
);
3978 ssh
->kex_ctx
= dh_setup_group(s
->p
, s
->g
);
3979 s
->kex_init_value
= SSH2_MSG_KEX_DH_GEX_INIT
;
3980 s
->kex_reply_value
= SSH2_MSG_KEX_DH_GEX_REPLY
;
3982 ssh
->pkt_ctx
|= SSH2_PKTCTX_DHGROUP1
;
3983 ssh
->kex_ctx
= dh_setup_group1();
3984 s
->kex_init_value
= SSH2_MSG_KEXDH_INIT
;
3985 s
->kex_reply_value
= SSH2_MSG_KEXDH_REPLY
;
3988 logevent("Doing Diffie-Hellman key exchange");
3990 * Now generate and send e for Diffie-Hellman.
3992 s
->e
= dh_create_e(ssh
->kex_ctx
, s
->nbits
* 2);
3993 ssh2_pkt_init(ssh
, s
->kex_init_value
);
3994 ssh2_pkt_addmp(ssh
, s
->e
);
3998 if (ssh
->pktin
.type
!= s
->kex_reply_value
) {
3999 bombout((ssh
,"expected key exchange reply packet from server"));
4002 ssh2_pkt_getstring(ssh
, &s
->hostkeydata
, &s
->hostkeylen
);
4003 s
->f
= ssh2_pkt_getmp(ssh
);
4004 ssh2_pkt_getstring(ssh
, &s
->sigdata
, &s
->siglen
);
4006 s
->K
= dh_find_K(ssh
->kex_ctx
, s
->f
);
4008 sha_string(&ssh
->exhash
, s
->hostkeydata
, s
->hostkeylen
);
4009 if (ssh
->kex
== &ssh_diffiehellman_gex
) {
4010 sha_uint32(&ssh
->exhash
, s
->pbits
);
4011 sha_mpint(&ssh
->exhash
, s
->p
);
4012 sha_mpint(&ssh
->exhash
, s
->g
);
4014 sha_mpint(&ssh
->exhash
, s
->e
);
4015 sha_mpint(&ssh
->exhash
, s
->f
);
4016 sha_mpint(&ssh
->exhash
, s
->K
);
4017 SHA_Final(&ssh
->exhash
, s
->exchange_hash
);
4019 dh_cleanup(ssh
->kex_ctx
);
4022 debug(("Exchange hash is:\n"));
4023 dmemdump(s
->exchange_hash
, 20);
4026 s
->hkey
= ssh
->hostkey
->newkey(s
->hostkeydata
, s
->hostkeylen
);
4028 !ssh
->hostkey
->verifysig(s
->hkey
, s
->sigdata
, s
->siglen
,
4029 s
->exchange_hash
, 20)) {
4030 bombout((ssh
,"Server's host key did not match the signature supplied"));
4035 * Authenticate remote host: verify host key. (We've already
4036 * checked the signature of the exchange hash.)
4038 s
->keystr
= ssh
->hostkey
->fmtkey(s
->hkey
);
4039 s
->fingerprint
= ssh
->hostkey
->fingerprint(s
->hkey
);
4040 verify_ssh_host_key(ssh
->frontend
,
4041 ssh
->savedhost
, ssh
->savedport
, ssh
->hostkey
->keytype
,
4042 s
->keystr
, s
->fingerprint
);
4043 if (s
->first_kex
) { /* don't bother logging this in rekeys */
4044 logevent("Host key fingerprint is:");
4045 logevent(s
->fingerprint
);
4047 sfree(s
->fingerprint
);
4049 ssh
->hostkey
->freekey(s
->hkey
);
4052 * Send SSH2_MSG_NEWKEYS.
4054 ssh2_pkt_init(ssh
, SSH2_MSG_NEWKEYS
);
4058 * Expect SSH2_MSG_NEWKEYS from server.
4061 if (ssh
->pktin
.type
!= SSH2_MSG_NEWKEYS
) {
4062 bombout((ssh
,"expected new-keys packet from server"));
4067 * Create and initialise session keys.
4069 if (ssh
->cs_cipher_ctx
)
4070 ssh
->cscipher
->free_context(ssh
->cs_cipher_ctx
);
4071 ssh
->cscipher
= s
->cscipher_tobe
;
4072 ssh
->cs_cipher_ctx
= ssh
->cscipher
->make_context();
4074 if (ssh
->sc_cipher_ctx
)
4075 ssh
->sccipher
->free_context(ssh
->sc_cipher_ctx
);
4076 ssh
->sccipher
= s
->sccipher_tobe
;
4077 ssh
->sc_cipher_ctx
= ssh
->sccipher
->make_context();
4079 if (ssh
->cs_mac_ctx
)
4080 ssh
->csmac
->free_context(ssh
->cs_mac_ctx
);
4081 ssh
->csmac
= s
->csmac_tobe
;
4082 ssh
->cs_mac_ctx
= ssh
->csmac
->make_context();
4084 if (ssh
->sc_mac_ctx
)
4085 ssh
->scmac
->free_context(ssh
->sc_mac_ctx
);
4086 ssh
->scmac
= s
->scmac_tobe
;
4087 ssh
->sc_mac_ctx
= ssh
->scmac
->make_context();
4089 if (ssh
->cs_comp_ctx
)
4090 ssh
->cscomp
->compress_cleanup(ssh
->cs_comp_ctx
);
4091 ssh
->cscomp
= s
->cscomp_tobe
;
4092 ssh
->cs_comp_ctx
= ssh
->cscomp
->compress_init();
4094 if (ssh
->sc_comp_ctx
)
4095 ssh
->sccomp
->decompress_cleanup(ssh
->sc_comp_ctx
);
4096 ssh
->sccomp
= s
->sccomp_tobe
;
4097 ssh
->sc_comp_ctx
= ssh
->sccomp
->decompress_init();
4100 * Set IVs after keys. Here we use the exchange hash from the
4101 * _first_ key exchange.
4104 unsigned char keyspace
[40];
4106 memcpy(ssh
->v2_session_id
, s
->exchange_hash
,
4107 sizeof(s
->exchange_hash
));
4108 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'C',keyspace
);
4109 ssh
->cscipher
->setkey(ssh
->cs_cipher_ctx
, keyspace
);
4110 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'D',keyspace
);
4111 ssh
->sccipher
->setkey(ssh
->sc_cipher_ctx
, keyspace
);
4112 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'A',keyspace
);
4113 ssh
->cscipher
->setiv(ssh
->cs_cipher_ctx
, keyspace
);
4114 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'B',keyspace
);
4115 ssh
->sccipher
->setiv(ssh
->sc_cipher_ctx
, keyspace
);
4116 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'E',keyspace
);
4117 ssh
->csmac
->setkey(ssh
->cs_mac_ctx
, keyspace
);
4118 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'F',keyspace
);
4119 ssh
->scmac
->setkey(ssh
->sc_mac_ctx
, keyspace
);
4123 sprintf(buf
, "Initialised %.200s client->server encryption",
4124 ssh
->cscipher
->text_name
);
4126 sprintf(buf
, "Initialised %.200s server->client encryption",
4127 ssh
->sccipher
->text_name
);
4129 if (ssh
->cscomp
->text_name
) {
4130 sprintf(buf
, "Initialised %.200s compression",
4131 ssh
->cscomp
->text_name
);
4134 if (ssh
->sccomp
->text_name
) {
4135 sprintf(buf
, "Initialised %.200s decompression",
4136 ssh
->sccomp
->text_name
);
4143 * If this is the first key exchange phase, we must pass the
4144 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4145 * wants to see it but because it will need time to initialise
4146 * itself before it sees an actual packet. In subsequent key
4147 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4148 * it would only confuse the layer above.
4150 if (!s
->first_kex
) {
4156 * Now we're encrypting. Begin returning 1 to the protocol main
4157 * function so that other things can run on top of the
4158 * transport. If we ever see a KEXINIT, we must go back to the
4161 while (!(ispkt
&& ssh
->pktin
.type
== SSH2_MSG_KEXINIT
)) {
4164 logevent("Server initiated key re-exchange");
4165 goto begin_key_exchange
;
4171 * Add data to an SSH2 channel output buffer.
4173 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
4176 bufchain_add(&c
->v
.v2
.outbuffer
, buf
, len
);
4180 * Attempt to send data on an SSH2 channel.
4182 static int ssh2_try_send(struct ssh_channel
*c
)
4186 while (c
->v
.v2
.remwindow
> 0 && bufchain_size(&c
->v
.v2
.outbuffer
) > 0) {
4189 bufchain_prefix(&c
->v
.v2
.outbuffer
, &data
, &len
);
4190 if ((unsigned)len
> c
->v
.v2
.remwindow
)
4191 len
= c
->v
.v2
.remwindow
;
4192 if ((unsigned)len
> c
->v
.v2
.remmaxpkt
)
4193 len
= c
->v
.v2
.remmaxpkt
;
4194 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_DATA
);
4195 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
4196 ssh2_pkt_addstring_start(ssh
);
4197 ssh2_pkt_addstring_data(ssh
, data
, len
);
4199 bufchain_consume(&c
->v
.v2
.outbuffer
, len
);
4200 c
->v
.v2
.remwindow
-= len
;
4204 * After having sent as much data as we can, return the amount
4207 return bufchain_size(&c
->v
.v2
.outbuffer
);
4211 * Potentially enlarge the window on an SSH2 channel.
4213 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
)
4218 * Never send WINDOW_ADJUST for a channel that the remote side
4219 * already thinks it's closed; there's no point, since it won't
4220 * be sending any more data anyway.
4225 if (newwin
> c
->v
.v2
.locwindow
) {
4226 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4227 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
4228 ssh2_pkt_adduint32(ssh
, newwin
- c
->v
.v2
.locwindow
);
4230 c
->v
.v2
.locwindow
= newwin
;
4235 * Handle the SSH2 userauth and connection layers.
4237 static void do_ssh2_authconn(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
4239 struct do_ssh2_authconn_state
{
4241 AUTH_INVALID
, AUTH_PUBLICKEY_AGENT
, AUTH_PUBLICKEY_FILE
,
4243 AUTH_KEYBOARD_INTERACTIVE
4247 AUTH_TYPE_PUBLICKEY
,
4248 AUTH_TYPE_PUBLICKEY_OFFER_LOUD
,
4249 AUTH_TYPE_PUBLICKEY_OFFER_QUIET
,
4251 AUTH_TYPE_KEYBOARD_INTERACTIVE
,
4252 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4254 int gotit
, need_pw
, can_pubkey
, can_passwd
, can_keyb_inter
;
4255 int tried_pubkey_config
, tried_agent
, tried_keyb_inter
;
4256 int kbd_inter_running
;
4258 int num_prompts
, curr_prompt
, echo
;
4263 void *publickey_blob
;
4264 int publickey_bloblen
;
4265 unsigned char request
[5], *response
, *p
;
4269 char *pkblob
, *alg
, *commentp
;
4270 int pklen
, alglen
, commentlen
;
4271 int siglen
, retlen
, len
;
4272 char *q
, *agentreq
, *ret
;
4275 crState(do_ssh2_authconn_state
);
4277 crBegin(ssh
->do_ssh2_authconn_crstate
);
4280 * Request userauth protocol, and await a response to it.
4282 ssh2_pkt_init(ssh
, SSH2_MSG_SERVICE_REQUEST
);
4283 ssh2_pkt_addstring(ssh
, "ssh-userauth");
4285 crWaitUntilV(ispkt
);
4286 if (ssh
->pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
) {
4287 bombout((ssh
,"Server refused user authentication protocol"));
4292 * We repeat this whole loop, including the username prompt,
4293 * until we manage a successful authentication. If the user
4294 * types the wrong _password_, they can be sent back to the
4295 * beginning to try another username, if this is configured on.
4296 * (If they specify a username in the config, they are never
4297 * asked, even if they do give a wrong password.)
4299 * I think this best serves the needs of
4301 * - the people who have no configuration, no keys, and just
4302 * want to try repeated (username,password) pairs until they
4303 * type both correctly
4305 * - people who have keys and configuration but occasionally
4306 * need to fall back to passwords
4308 * - people with a key held in Pageant, who might not have
4309 * logged in to a particular machine before; so they want to
4310 * type a username, and then _either_ their key will be
4311 * accepted, _or_ they will type a password. If they mistype
4312 * the username they will want to be able to get back and
4315 s
->username
[0] = '\0';
4316 s
->got_username
= FALSE
;
4321 if (s
->got_username
&& !cfg
.change_username
) {
4323 * We got a username last time round this loop, and
4324 * with change_username turned off we don't try to get
4327 } else if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
4328 if (ssh_get_line
&& !ssh_getline_pw_only
) {
4329 if (!ssh_get_line("login as: ",
4330 s
->username
, sizeof(s
->username
), FALSE
)) {
4332 * get_line failed to get a username.
4335 logevent("No username provided. Abandoning session.");
4336 ssh
->state
= SSH_STATE_CLOSED
;
4340 int ret
; /* need not be saved across crReturn */
4341 c_write_str(ssh
, "login as: ");
4343 setup_userpass_input(ssh
, s
->username
, sizeof(s
->username
), 1);
4345 crWaitUntilV(!ispkt
);
4346 ret
= process_userpass_input(ssh
, in
, inlen
);
4350 c_write_str(ssh
, "\r\n");
4352 s
->username
[strcspn(s
->username
, "\n\r")] = '\0';
4355 strncpy(s
->username
, cfg
.username
, sizeof(s
->username
));
4356 s
->username
[sizeof(s
->username
)-1] = '\0';
4357 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
4358 sprintf(stuff
, "Using username \"%s\".\r\n", s
->username
);
4359 c_write_str(ssh
, stuff
);
4362 s
->got_username
= TRUE
;
4365 * Send an authentication request using method "none": (a)
4366 * just in case it succeeds, and (b) so that we know what
4367 * authentication methods we can usefully try next.
4369 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4371 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4372 ssh2_pkt_addstring(ssh
, s
->username
);
4373 ssh2_pkt_addstring(ssh
, "ssh-connection");/* service requested */
4374 ssh2_pkt_addstring(ssh
, "none"); /* method */
4376 s
->type
= AUTH_TYPE_NONE
;
4378 s
->we_are_in
= FALSE
;
4380 s
->tried_pubkey_config
= FALSE
;
4381 s
->tried_agent
= FALSE
;
4382 s
->tried_keyb_inter
= FALSE
;
4383 s
->kbd_inter_running
= FALSE
;
4384 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
4387 logeventf(ssh
->frontend
,
4388 "Reading private key file \"%.150s\"", cfg
.keyfile
);
4389 keytype
= key_type(cfg
.keyfile
);
4390 if (keytype
== SSH_KEYTYPE_SSH2
) {
4392 ssh2_userkey_loadpub(cfg
.keyfile
, NULL
,
4393 &s
->publickey_bloblen
);
4396 logeventf(ssh
->frontend
,
4397 "Unable to use this key file (%s)",
4398 key_type_to_str(keytype
));
4399 sprintf(msgbuf
, "Unable to use key file \"%.150s\" (%s)\r\n",
4400 cfg
.keyfile
, key_type_to_str(keytype
));
4401 c_write_str(ssh
, msgbuf
);
4402 s
->publickey_blob
= NULL
;
4405 s
->publickey_blob
= NULL
;
4409 * Wait for the result of the last authentication request.
4412 crWaitUntilV(ispkt
);
4413 while (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_BANNER
) {
4417 * Don't show the banner if we're operating in
4418 * non-verbose non-interactive mode. (It's probably
4419 * a script, which means nobody will read the
4420 * banner _anyway_, and moreover the printing of
4421 * the banner will screw up processing on the
4422 * output of (say) plink.)
4424 if (flags
& (FLAG_VERBOSE
| FLAG_INTERACTIVE
)) {
4425 ssh2_pkt_getstring(ssh
, &banner
, &size
);
4427 c_write_untrusted(ssh
, banner
, size
);
4429 crWaitUntilV(ispkt
);
4431 if (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_SUCCESS
) {
4432 logevent("Access granted");
4433 s
->we_are_in
= TRUE
;
4437 if (s
->kbd_inter_running
&&
4438 ssh
->pktin
.type
== SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4440 * This is either a further set-of-prompts packet
4441 * in keyboard-interactive authentication, or it's
4442 * the same one and we came back here with `gotit'
4443 * set. In the former case, we must reset the
4444 * curr_prompt variable.
4448 } else if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_FAILURE
) {
4449 bombout((ssh
,"Strange packet received during authentication: type %d",
4457 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4458 * we can look at the string in it and know what we can
4459 * helpfully try next.
4461 if (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
) {
4464 ssh2_pkt_getstring(ssh
, &methods
, &methlen
);
4465 s
->kbd_inter_running
= FALSE
;
4466 if (!ssh2_pkt_getbool(ssh
)) {
4468 * We have received an unequivocal Access
4469 * Denied. This can translate to a variety of
4472 * - if we'd just tried "none" authentication,
4473 * it's not worth printing anything at all
4475 * - if we'd just tried a public key _offer_,
4476 * the message should be "Server refused our
4477 * key" (or no message at all if the key
4478 * came from Pageant)
4480 * - if we'd just tried anything else, the
4481 * message really should be "Access denied".
4483 * Additionally, if we'd just tried password
4484 * authentication, we should break out of this
4485 * whole loop so as to go back to the username
4488 if (s
->type
== AUTH_TYPE_NONE
) {
4490 } else if (s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
||
4491 s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_QUIET
) {
4492 if (s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
)
4493 c_write_str(ssh
, "Server refused our key\r\n");
4494 logevent("Server refused public key");
4495 } else if (s
->type
==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
) {
4496 /* server declined keyboard-interactive; ignore */
4498 c_write_str(ssh
, "Access denied\r\n");
4499 logevent("Access denied");
4500 if (s
->type
== AUTH_TYPE_PASSWORD
) {
4501 s
->we_are_in
= FALSE
;
4506 c_write_str(ssh
, "Further authentication required\r\n");
4507 logevent("Further authentication required");
4511 in_commasep_string("publickey", methods
, methlen
);
4513 in_commasep_string("password", methods
, methlen
);
4514 s
->can_keyb_inter
= cfg
.try_ki_auth
&&
4515 in_commasep_string("keyboard-interactive", methods
, methlen
);
4519 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4522 * Most password/passphrase prompts will be
4523 * non-echoing, so we set this to 0 by default.
4524 * Exception is that some keyboard-interactive prompts
4525 * can be echoing, in which case we'll set this to 1.
4529 if (!s
->method
&& s
->can_pubkey
&&
4530 agent_exists() && !s
->tried_agent
) {
4532 * Attempt public-key authentication using Pageant.
4537 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4538 ssh
->pkt_ctx
|= SSH2_PKTCTX_PUBLICKEY
;
4540 s
->tried_agent
= TRUE
;
4542 logevent("Pageant is running. Requesting keys.");
4544 /* Request the keys held by the agent. */
4545 PUT_32BIT(s
->request
, 1);
4546 s
->request
[4] = SSH2_AGENTC_REQUEST_IDENTITIES
;
4547 agent_query(s
->request
, 5, &r
, &s
->responselen
);
4548 s
->response
= (unsigned char *) r
;
4549 if (s
->response
&& s
->responselen
>= 5 &&
4550 s
->response
[4] == SSH2_AGENT_IDENTITIES_ANSWER
) {
4551 s
->p
= s
->response
+ 5;
4552 s
->nkeys
= GET_32BIT(s
->p
);
4556 sprintf(buf
, "Pageant has %d SSH2 keys", s
->nkeys
);
4559 for (s
->keyi
= 0; s
->keyi
< s
->nkeys
; s
->keyi
++) {
4564 sprintf(buf
, "Trying Pageant key #%d", s
->keyi
);
4567 s
->pklen
= GET_32BIT(s
->p
);
4569 if (s
->publickey_blob
&&
4570 s
->pklen
== s
->publickey_bloblen
&&
4571 !memcmp(s
->p
, s
->publickey_blob
,
4572 s
->publickey_bloblen
)) {
4573 logevent("This key matches configured key file");
4574 s
->tried_pubkey_config
= 1;
4578 s
->alglen
= GET_32BIT(s
->pkblob
);
4579 s
->alg
= s
->pkblob
+ 4;
4580 s
->commentlen
= GET_32BIT(s
->p
);
4583 s
->p
+= s
->commentlen
;
4584 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4585 ssh2_pkt_addstring(ssh
, s
->username
);
4586 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4587 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4588 ssh2_pkt_addbool(ssh
, FALSE
); /* no signature included */
4589 ssh2_pkt_addstring_start(ssh
);
4590 ssh2_pkt_addstring_data(ssh
, s
->alg
, s
->alglen
);
4591 ssh2_pkt_addstring_start(ssh
);
4592 ssh2_pkt_addstring_data(ssh
, s
->pkblob
, s
->pklen
);
4595 crWaitUntilV(ispkt
);
4596 if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4597 logevent("Key refused");
4601 if (flags
& FLAG_VERBOSE
) {
4602 c_write_str(ssh
, "Authenticating with "
4604 c_write(ssh
, s
->commentp
, s
->commentlen
);
4605 c_write_str(ssh
, "\" from agent\r\n");
4609 * Server is willing to accept the key.
4610 * Construct a SIGN_REQUEST.
4612 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4613 ssh2_pkt_addstring(ssh
, s
->username
);
4614 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4615 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4616 ssh2_pkt_addbool(ssh
, TRUE
);
4617 ssh2_pkt_addstring_start(ssh
);
4618 ssh2_pkt_addstring_data(ssh
, s
->alg
, s
->alglen
);
4619 ssh2_pkt_addstring_start(ssh
);
4620 ssh2_pkt_addstring_data(ssh
, s
->pkblob
, s
->pklen
);
4622 s
->siglen
= ssh
->pktout
.length
- 5 + 4 + 20;
4623 s
->len
= 1; /* message type */
4624 s
->len
+= 4 + s
->pklen
; /* key blob */
4625 s
->len
+= 4 + s
->siglen
; /* data to sign */
4626 s
->len
+= 4; /* flags */
4627 s
->agentreq
= smalloc(4 + s
->len
);
4628 PUT_32BIT(s
->agentreq
, s
->len
);
4629 s
->q
= s
->agentreq
+ 4;
4630 *s
->q
++ = SSH2_AGENTC_SIGN_REQUEST
;
4631 PUT_32BIT(s
->q
, s
->pklen
);
4633 memcpy(s
->q
, s
->pkblob
, s
->pklen
);
4635 PUT_32BIT(s
->q
, s
->siglen
);
4637 /* Now the data to be signed... */
4638 PUT_32BIT(s
->q
, 20);
4640 memcpy(s
->q
, ssh
->v2_session_id
, 20);
4642 memcpy(s
->q
, ssh
->pktout
.data
+ 5,
4643 ssh
->pktout
.length
- 5);
4644 s
->q
+= ssh
->pktout
.length
- 5;
4645 /* And finally the (zero) flags word. */
4647 agent_query(s
->agentreq
, s
->len
+ 4, &vret
, &s
->retlen
);
4651 if (s
->ret
[4] == SSH2_AGENT_SIGN_RESPONSE
) {
4652 logevent("Sending Pageant's response");
4653 ssh2_add_sigblob(ssh
, s
->pkblob
, s
->pklen
,
4655 GET_32BIT(s
->ret
+ 5));
4661 ("Pageant failed to answer challenge");
4671 if (!s
->method
&& s
->can_pubkey
&& s
->publickey_blob
4672 && !s
->tried_pubkey_config
) {
4673 unsigned char *pub_blob
;
4674 char *algorithm
, *comment
;
4677 s
->tried_pubkey_config
= TRUE
;
4679 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4680 ssh
->pkt_ctx
|= SSH2_PKTCTX_PUBLICKEY
;
4683 * Try the public key supplied in the configuration.
4685 * First, offer the public blob to see if the server is
4686 * willing to accept it.
4688 pub_blob
= ssh2_userkey_loadpub(cfg
.keyfile
, &algorithm
,
4691 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4692 ssh2_pkt_addstring(ssh
, s
->username
);
4693 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4694 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4695 ssh2_pkt_addbool(ssh
, FALSE
); /* no signature included */
4696 ssh2_pkt_addstring(ssh
, algorithm
);
4697 ssh2_pkt_addstring_start(ssh
);
4698 ssh2_pkt_addstring_data(ssh
, pub_blob
, pub_blob_len
);
4700 logevent("Offered public key"); /* FIXME */
4702 crWaitUntilV(ispkt
);
4703 if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4705 s
->type
= AUTH_TYPE_PUBLICKEY_OFFER_LOUD
;
4706 continue; /* key refused; give up on it */
4709 logevent("Offer of public key accepted");
4711 * Actually attempt a serious authentication using
4714 if (ssh2_userkey_encrypted(cfg
.keyfile
, &comment
)) {
4715 sprintf(s
->pwprompt
,
4716 "Passphrase for key \"%.100s\": ",
4722 c_write_str(ssh
, "Authenticating with public key \"");
4723 c_write_str(ssh
, comment
);
4724 c_write_str(ssh
, "\"\r\n");
4725 s
->method
= AUTH_PUBLICKEY_FILE
;
4729 if (!s
->method
&& s
->can_keyb_inter
&& !s
->tried_keyb_inter
) {
4730 s
->method
= AUTH_KEYBOARD_INTERACTIVE
;
4731 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4732 s
->tried_keyb_inter
= TRUE
;
4734 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4735 ssh
->pkt_ctx
|= SSH2_PKTCTX_KBDINTER
;
4737 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4738 ssh2_pkt_addstring(ssh
, s
->username
);
4739 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4740 ssh2_pkt_addstring(ssh
, "keyboard-interactive"); /* method */
4741 ssh2_pkt_addstring(ssh
, ""); /* lang */
4742 ssh2_pkt_addstring(ssh
, "");
4745 crWaitUntilV(ispkt
);
4746 if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4747 if (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
)
4749 logevent("Keyboard-interactive authentication refused");
4750 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
;
4754 s
->kbd_inter_running
= TRUE
;
4758 if (s
->kbd_inter_running
) {
4759 s
->method
= AUTH_KEYBOARD_INTERACTIVE
;
4760 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4761 s
->tried_keyb_inter
= TRUE
;
4763 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4764 ssh
->pkt_ctx
|= SSH2_PKTCTX_KBDINTER
;
4766 if (s
->curr_prompt
== 0) {
4768 * We've got a fresh USERAUTH_INFO_REQUEST.
4769 * Display header data, and start going through
4772 char *name
, *inst
, *lang
;
4773 int name_len
, inst_len
, lang_len
;
4775 ssh2_pkt_getstring(ssh
, &name
, &name_len
);
4776 ssh2_pkt_getstring(ssh
, &inst
, &inst_len
);
4777 ssh2_pkt_getstring(ssh
, &lang
, &lang_len
);
4779 c_write_untrusted(ssh
, name
, name_len
);
4780 c_write_str(ssh
, "\r\n");
4783 c_write_untrusted(ssh
, inst
, inst_len
);
4784 c_write_str(ssh
, "\r\n");
4786 s
->num_prompts
= ssh2_pkt_getuint32(ssh
);
4790 * If there are prompts remaining in the packet,
4791 * display one and get a response.
4793 if (s
->curr_prompt
< s
->num_prompts
) {
4797 ssh2_pkt_getstring(ssh
, &prompt
, &prompt_len
);
4798 if (prompt_len
> 0) {
4799 strncpy(s
->pwprompt
, prompt
, sizeof(s
->pwprompt
));
4800 s
->pwprompt
[prompt_len
< sizeof(s
->pwprompt
) ?
4801 prompt_len
: sizeof(s
->pwprompt
)-1] = '\0';
4804 "<server failed to send prompt>: ");
4806 s
->echo
= ssh2_pkt_getbool(ssh
);
4812 if (!s
->method
&& s
->can_passwd
) {
4813 s
->method
= AUTH_PASSWORD
;
4814 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4815 ssh
->pkt_ctx
|= SSH2_PKTCTX_PASSWORD
;
4816 sprintf(s
->pwprompt
, "%.90s@%.90s's password: ", s
->username
,
4823 if (!ssh_get_line(s
->pwprompt
, s
->password
,
4824 sizeof(s
->password
), TRUE
)) {
4826 * get_line failed to get a password (for
4827 * example because one was supplied on the
4828 * command line which has already failed to
4831 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
4832 ssh2_pkt_adduint32(ssh
,SSH2_DISCONNECT_BY_APPLICATION
);
4833 ssh2_pkt_addstring(ssh
, "No more passwords available"
4835 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
4837 logevent("Unable to authenticate");
4838 connection_fatal(ssh
->frontend
,
4839 "Unable to authenticate");
4840 ssh
->state
= SSH_STATE_CLOSED
;
4844 int ret
; /* need not be saved across crReturn */
4845 c_write_untrusted(ssh
, s
->pwprompt
, strlen(s
->pwprompt
));
4848 setup_userpass_input(ssh
, s
->password
,
4849 sizeof(s
->password
), s
->echo
);
4851 crWaitUntilV(!ispkt
);
4852 ret
= process_userpass_input(ssh
, in
, inlen
);
4856 c_write_str(ssh
, "\r\n");
4860 if (s
->method
== AUTH_PUBLICKEY_FILE
) {
4862 * We have our passphrase. Now try the actual authentication.
4864 struct ssh2_userkey
*key
;
4866 key
= ssh2_load_userkey(cfg
.keyfile
, s
->password
);
4867 if (key
== SSH2_WRONG_PASSPHRASE
|| key
== NULL
) {
4868 if (key
== SSH2_WRONG_PASSPHRASE
) {
4869 c_write_str(ssh
, "Wrong passphrase\r\n");
4870 s
->tried_pubkey_config
= FALSE
;
4872 c_write_str(ssh
, "Unable to load private key\r\n");
4873 s
->tried_pubkey_config
= TRUE
;
4875 /* Send a spurious AUTH_NONE to return to the top. */
4876 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4877 ssh2_pkt_addstring(ssh
, s
->username
);
4878 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4879 ssh2_pkt_addstring(ssh
, "none"); /* method */
4881 s
->type
= AUTH_TYPE_NONE
;
4883 unsigned char *pkblob
, *sigblob
, *sigdata
;
4884 int pkblob_len
, sigblob_len
, sigdata_len
;
4887 * We have loaded the private key and the server
4888 * has announced that it's willing to accept it.
4889 * Hallelujah. Generate a signature and send it.
4891 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4892 ssh2_pkt_addstring(ssh
, s
->username
);
4893 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4894 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4895 ssh2_pkt_addbool(ssh
, TRUE
);
4896 ssh2_pkt_addstring(ssh
, key
->alg
->name
);
4897 pkblob
= key
->alg
->public_blob(key
->data
, &pkblob_len
);
4898 ssh2_pkt_addstring_start(ssh
);
4899 ssh2_pkt_addstring_data(ssh
, pkblob
, pkblob_len
);
4902 * The data to be signed is:
4906 * followed by everything so far placed in the
4909 sigdata_len
= ssh
->pktout
.length
- 5 + 4 + 20;
4910 sigdata
= smalloc(sigdata_len
);
4911 PUT_32BIT(sigdata
, 20);
4912 memcpy(sigdata
+ 4, ssh
->v2_session_id
, 20);
4913 memcpy(sigdata
+ 24, ssh
->pktout
.data
+ 5,
4914 ssh
->pktout
.length
- 5);
4915 sigblob
= key
->alg
->sign(key
->data
, sigdata
,
4916 sigdata_len
, &sigblob_len
);
4917 ssh2_add_sigblob(ssh
, pkblob
, pkblob_len
,
4918 sigblob
, sigblob_len
);
4924 s
->type
= AUTH_TYPE_PUBLICKEY
;
4926 } else if (s
->method
== AUTH_PASSWORD
) {
4928 * We send the password packet lumped tightly together with
4929 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4930 * string long enough to make the total length of the two
4931 * packets constant. This should ensure that a passive
4932 * listener doing traffic analyis can't work out the length
4935 * For this to work, we need an assumption about the
4936 * maximum length of the password packet. I think 256 is
4937 * pretty conservative. Anyone using a password longer than
4938 * that probably doesn't have much to worry about from
4939 * people who find out how long their password is!
4941 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4942 ssh2_pkt_addstring(ssh
, s
->username
);
4943 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4944 ssh2_pkt_addstring(ssh
, "password");
4945 ssh2_pkt_addbool(ssh
, FALSE
);
4946 ssh2_pkt_addstring(ssh
, s
->password
);
4947 ssh2_pkt_defer(ssh
);
4949 * We'll include a string that's an exact multiple of the
4950 * cipher block size. If the cipher is NULL for some
4951 * reason, we don't do this trick at all because we gain
4954 if (ssh
->cscipher
) {
4957 stringlen
= (256 - ssh
->deferred_len
);
4958 stringlen
+= ssh
->cscipher
->blksize
- 1;
4959 stringlen
-= (stringlen
% ssh
->cscipher
->blksize
);
4962 * Temporarily disable actual compression,
4963 * so we can guarantee to get this string
4964 * exactly the length we want it. The
4965 * compression-disabling routine should
4966 * return an integer indicating how many
4967 * bytes we should adjust our string length
4971 ssh
->cscomp
->disable_compression(ssh
->cs_comp_ctx
);
4973 ssh2_pkt_init(ssh
, SSH2_MSG_IGNORE
);
4974 ssh2_pkt_addstring_start(ssh
);
4975 for (i
= 0; i
< stringlen
; i
++) {
4976 char c
= (char) random_byte();
4977 ssh2_pkt_addstring_data(ssh
, &c
, 1);
4979 ssh2_pkt_defer(ssh
);
4981 ssh_pkt_defersend(ssh
);
4982 logevent("Sent password");
4983 s
->type
= AUTH_TYPE_PASSWORD
;
4984 } else if (s
->method
== AUTH_KEYBOARD_INTERACTIVE
) {
4985 if (s
->curr_prompt
== 0) {
4986 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_INFO_RESPONSE
);
4987 ssh2_pkt_adduint32(ssh
, s
->num_prompts
);
4989 if (s
->need_pw
) { /* only add pw if we just got one! */
4990 ssh2_pkt_addstring(ssh
, s
->password
);
4991 memset(s
->password
, 0, sizeof(s
->password
));
4994 if (s
->curr_prompt
>= s
->num_prompts
) {
4998 * If there are prompts remaining, we set
4999 * `gotit' so that we won't attempt to get
5000 * another packet. Then we go back round the
5001 * loop and will end up retrieving another
5002 * prompt out of the existing packet. Funky or
5007 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
5009 c_write_str(ssh
, "No supported authentication methods"
5010 " left to try!\r\n");
5011 logevent("No supported authentications offered."
5013 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
5014 ssh2_pkt_adduint32(ssh
, SSH2_DISCONNECT_BY_APPLICATION
);
5015 ssh2_pkt_addstring(ssh
, "No supported authentication"
5016 " methods available");
5017 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5019 ssh
->state
= SSH_STATE_CLOSED
;
5023 } while (!s
->we_are_in
);
5026 * Now we're authenticated for the connection protocol. The
5027 * connection protocol will automatically have started at this
5028 * point; there's no need to send SERVICE_REQUEST.
5032 * So now create a channel with a session in it.
5034 ssh
->channels
= newtree234(ssh_channelcmp
);
5035 ssh
->mainchan
= smalloc(sizeof(struct ssh_channel
));
5036 ssh
->mainchan
->ssh
= ssh
;
5037 ssh
->mainchan
->localid
= alloc_channel_id(ssh
);
5038 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN
);
5039 ssh2_pkt_addstring(ssh
, "session");
5040 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->localid
);
5041 ssh
->mainchan
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5042 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->v
.v2
.locwindow
);/* our window size */
5043 ssh2_pkt_adduint32(ssh
, 0x4000UL
); /* our max pkt size */
5045 crWaitUntilV(ispkt
);
5046 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
5047 bombout((ssh
,"Server refused to open a session"));
5049 /* FIXME: error data comes back in FAILURE packet */
5051 if (ssh2_pkt_getuint32(ssh
) != ssh
->mainchan
->localid
) {
5052 bombout((ssh
,"Server's channel confirmation cited wrong channel"));
5055 ssh
->mainchan
->remoteid
= ssh2_pkt_getuint32(ssh
);
5056 ssh
->mainchan
->type
= CHAN_MAINSESSION
;
5057 ssh
->mainchan
->closes
= 0;
5058 ssh
->mainchan
->v
.v2
.remwindow
= ssh2_pkt_getuint32(ssh
);
5059 ssh
->mainchan
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32(ssh
);
5060 bufchain_init(&ssh
->mainchan
->v
.v2
.outbuffer
);
5061 add234(ssh
->channels
, ssh
->mainchan
);
5062 logevent("Opened channel for session");
5065 * Potentially enable X11 forwarding.
5067 if (cfg
.x11_forward
) {
5068 char proto
[20], data
[64];
5069 logevent("Requesting X11 forwarding");
5070 ssh
->x11auth
= x11_invent_auth(proto
, sizeof(proto
),
5071 data
, sizeof(data
));
5072 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5073 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
5074 ssh2_pkt_addstring(ssh
, "x11-req");
5075 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5076 ssh2_pkt_addbool(ssh
, 0); /* many connections */
5077 ssh2_pkt_addstring(ssh
, proto
);
5078 ssh2_pkt_addstring(ssh
, data
);
5079 ssh2_pkt_adduint32(ssh
, 0); /* screen number */
5083 crWaitUntilV(ispkt
);
5084 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5085 unsigned i
= ssh2_pkt_getuint32(ssh
);
5086 struct ssh_channel
*c
;
5087 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5089 continue; /* nonexistent channel */
5090 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5092 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5094 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5095 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5096 bombout((ssh
,"Unexpected response to X11 forwarding request:"
5097 " packet type %d", ssh
->pktin
.type
));
5100 logevent("X11 forwarding refused");
5102 logevent("X11 forwarding enabled");
5103 ssh
->X11_fwd_enabled
= TRUE
;
5108 * Enable port forwardings.
5113 int sport
,dport
,sserv
,dserv
;
5114 char sports
[256], dports
[256], host
[256];
5117 ssh
->rportfwds
= newtree234(ssh_rportcmp_ssh2
);
5118 /* Add port forwardings. */
5119 ssh
->portfwd_strptr
= cfg
.portfwd
;
5120 while (*ssh
->portfwd_strptr
) {
5121 type
= *ssh
->portfwd_strptr
++;
5123 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= '\t')
5124 sports
[n
++] = *ssh
->portfwd_strptr
++;
5126 if (*ssh
->portfwd_strptr
== '\t')
5127 ssh
->portfwd_strptr
++;
5129 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= ':')
5130 host
[n
++] = *ssh
->portfwd_strptr
++;
5132 if (*ssh
->portfwd_strptr
== ':')
5133 ssh
->portfwd_strptr
++;
5135 while (*ssh
->portfwd_strptr
)
5136 dports
[n
++] = *ssh
->portfwd_strptr
++;
5138 ssh
->portfwd_strptr
++;
5139 dport
= atoi(dports
);
5143 dport
= net_service_lookup(dports
);
5146 "Service lookup failed for destination port \"%s\"",
5151 sport
= atoi(sports
);
5155 sport
= net_service_lookup(sports
);
5158 "Service lookup failed for source port \"%s\"",
5163 if (sport
&& dport
) {
5165 pfd_addforward(host
, dport
, sport
, ssh
);
5166 sprintf(buf
, "Local port %.*s%.*s%d%.*s forwarding to"
5167 " %s:%.*s%.*s%d%.*s",
5168 (int)(sserv ?
strlen(sports
) : 0), sports
,
5169 sserv
, "(", sport
, sserv
, ")",
5171 (int)(dserv ?
strlen(dports
) : 0), dports
,
5172 dserv
, "(", dport
, dserv
, ")");
5175 struct ssh_rportfwd
*pf
;
5176 pf
= smalloc(sizeof(*pf
));
5177 strcpy(pf
->dhost
, host
);
5180 if (add234(ssh
->rportfwds
, pf
) != pf
) {
5182 "Duplicate remote port forwarding to %s:%d",
5187 sprintf(buf
, "Requesting remote port %.*s%.*s%d%.*s"
5188 " forward to %s:%.*s%.*s%d%.*s",
5189 (int)(sserv ?
strlen(sports
) : 0), sports
,
5190 sserv
, "(", sport
, sserv
, ")",
5192 (int)(dserv ?
strlen(dports
) : 0), dports
,
5193 dserv
, "(", dport
, dserv
, ")");
5195 ssh2_pkt_init(ssh
, SSH2_MSG_GLOBAL_REQUEST
);
5196 ssh2_pkt_addstring(ssh
, "tcpip-forward");
5197 ssh2_pkt_addbool(ssh
, 1);/* want reply */
5198 if (cfg
.rport_acceptall
)
5199 ssh2_pkt_addstring(ssh
, "0.0.0.0");
5201 ssh2_pkt_addstring(ssh
, "127.0.0.1");
5202 ssh2_pkt_adduint32(ssh
, sport
);
5206 crWaitUntilV(ispkt
);
5207 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5208 unsigned i
= ssh2_pkt_getuint32(ssh
);
5209 struct ssh_channel
*c
;
5210 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5212 continue;/* nonexistent channel */
5213 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5215 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5217 if (ssh
->pktin
.type
!= SSH2_MSG_REQUEST_SUCCESS
) {
5218 if (ssh
->pktin
.type
!= SSH2_MSG_REQUEST_FAILURE
) {
5219 bombout((ssh
,"Unexpected response to port "
5220 "forwarding request: packet type %d",
5224 logevent("Server refused this port forwarding");
5226 logevent("Remote port forwarding enabled");
5235 * Potentially enable agent forwarding.
5237 if (cfg
.agentfwd
&& agent_exists()) {
5238 logevent("Requesting OpenSSH-style agent forwarding");
5239 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5240 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
5241 ssh2_pkt_addstring(ssh
, "auth-agent-req@openssh.com");
5242 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5246 crWaitUntilV(ispkt
);
5247 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5248 unsigned i
= ssh2_pkt_getuint32(ssh
);
5249 struct ssh_channel
*c
;
5250 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5252 continue; /* nonexistent channel */
5253 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5255 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5257 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5258 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5259 bombout((ssh
,"Unexpected response to agent forwarding request:"
5260 " packet type %d", ssh
->pktin
.type
));
5263 logevent("Agent forwarding refused");
5265 logevent("Agent forwarding enabled");
5266 ssh
->agentfwd_enabled
= TRUE
;
5271 * Now allocate a pty for the session.
5274 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5275 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
); /* recipient channel */
5276 ssh2_pkt_addstring(ssh
, "pty-req");
5277 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5278 ssh2_pkt_addstring(ssh
, cfg
.termtype
);
5279 ssh2_pkt_adduint32(ssh
, ssh
->term_width
);
5280 ssh2_pkt_adduint32(ssh
, ssh
->term_height
);
5281 ssh2_pkt_adduint32(ssh
, 0); /* pixel width */
5282 ssh2_pkt_adduint32(ssh
, 0); /* pixel height */
5283 ssh2_pkt_addstring_start(ssh
);
5284 ssh2_pkt_addstring_data(ssh
, "\0", 1); /* TTY_OP_END, no special options */
5286 ssh
->state
= SSH_STATE_INTERMED
;
5289 crWaitUntilV(ispkt
);
5290 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5291 unsigned i
= ssh2_pkt_getuint32(ssh
);
5292 struct ssh_channel
*c
;
5293 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5295 continue; /* nonexistent channel */
5296 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5298 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5300 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5301 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5302 bombout((ssh
,"Unexpected response to pty request:"
5303 " packet type %d", ssh
->pktin
.type
));
5306 c_write_str(ssh
, "Server refused to allocate pty\r\n");
5307 ssh
->editing
= ssh
->echoing
= 1;
5309 logevent("Allocated pty");
5312 ssh
->editing
= ssh
->echoing
= 1;
5316 * Start a shell or a remote command. We may have to attempt
5317 * this twice if the config data has provided a second choice
5324 if (ssh
->fallback_cmd
) {
5325 subsys
= cfg
.ssh_subsys2
;
5326 cmd
= cfg
.remote_cmd_ptr2
;
5328 subsys
= cfg
.ssh_subsys
;
5329 cmd
= cfg
.remote_cmd_ptr
;
5332 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5333 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
); /* recipient channel */
5335 ssh2_pkt_addstring(ssh
, "subsystem");
5336 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5337 ssh2_pkt_addstring(ssh
, cmd
);
5339 ssh2_pkt_addstring(ssh
, "exec");
5340 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5341 ssh2_pkt_addstring(ssh
, cmd
);
5343 ssh2_pkt_addstring(ssh
, "shell");
5344 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5348 crWaitUntilV(ispkt
);
5349 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5350 unsigned i
= ssh2_pkt_getuint32(ssh
);
5351 struct ssh_channel
*c
;
5352 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5354 continue; /* nonexistent channel */
5355 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5357 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5358 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5359 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5360 bombout((ssh
,"Unexpected response to shell/command request:"
5361 " packet type %d", ssh
->pktin
.type
));
5365 * We failed to start the command. If this is the
5366 * fallback command, we really are finished; if it's
5367 * not, and if the fallback command exists, try falling
5368 * back to it before complaining.
5370 if (!ssh
->fallback_cmd
&& cfg
.remote_cmd_ptr2
!= NULL
) {
5371 logevent("Primary command failed; attempting fallback");
5372 ssh
->fallback_cmd
= TRUE
;
5375 bombout((ssh
,"Server refused to start a shell/command"));
5378 logevent("Started a shell/command");
5383 ssh
->state
= SSH_STATE_SESSION
;
5384 if (ssh
->size_needed
)
5385 ssh_size(ssh
, ssh
->term_width
, ssh
->term_height
);
5386 if (ssh
->eof_needed
)
5387 ssh_special(ssh
, TS_EOF
);
5393 ldisc_send(ssh
->ldisc
, NULL
, 0, 0);/* cause ldisc to notice changes */
5397 s
->try_send
= FALSE
;
5399 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
5400 ssh
->pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
5403 unsigned i
= ssh2_pkt_getuint32(ssh
);
5404 struct ssh_channel
*c
;
5405 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5407 continue; /* nonexistent channel */
5408 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
5409 ssh2_pkt_getuint32(ssh
) != SSH2_EXTENDED_DATA_STDERR
)
5410 continue; /* extended but not stderr */
5411 ssh2_pkt_getstring(ssh
, &data
, &length
);
5414 c
->v
.v2
.locwindow
-= length
;
5416 case CHAN_MAINSESSION
:
5418 from_backend(ssh
->frontend
, ssh
->pktin
.type
==
5419 SSH2_MSG_CHANNEL_EXTENDED_DATA
,
5423 bufsize
= x11_send(c
->u
.x11
.s
, data
, length
);
5426 bufsize
= pfd_send(c
->u
.pfd
.s
, data
, length
);
5429 while (length
> 0) {
5430 if (c
->u
.a
.lensofar
< 4) {
5431 int l
= min(4 - c
->u
.a
.lensofar
, length
);
5432 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
,
5436 c
->u
.a
.lensofar
+= l
;
5438 if (c
->u
.a
.lensofar
== 4) {
5440 4 + GET_32BIT(c
->u
.a
.msglen
);
5441 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
5442 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
5444 if (c
->u
.a
.lensofar
>= 4 && length
> 0) {
5446 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
5448 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
,
5452 c
->u
.a
.lensofar
+= l
;
5454 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
5455 void *reply
, *sentreply
;
5457 agent_query(c
->u
.a
.message
,
5458 c
->u
.a
.totallen
, &reply
,
5463 /* Fake SSH_AGENT_FAILURE. */
5464 sentreply
= "\0\0\0\1\5";
5467 ssh2_add_channel_data(c
, sentreply
, replylen
);
5471 sfree(c
->u
.a
.message
);
5472 c
->u
.a
.lensofar
= 0;
5479 * If we are not buffering too much data,
5480 * enlarge the window again at the remote side.
5482 if (bufsize
< OUR_V2_WINSIZE
)
5483 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
5485 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_EOF
) {
5486 unsigned i
= ssh2_pkt_getuint32(ssh
);
5487 struct ssh_channel
*c
;
5489 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5491 continue; /* nonexistent channel */
5493 if (c
->type
== CHAN_X11
) {
5495 * Remote EOF on an X11 channel means we should
5496 * wrap up and close the channel ourselves.
5498 x11_close(c
->u
.x11
.s
);
5500 } else if (c
->type
== CHAN_AGENT
) {
5502 } else if (c
->type
== CHAN_SOCKDATA
) {
5503 pfd_close(c
->u
.pfd
.s
);
5506 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_CLOSE
) {
5507 unsigned i
= ssh2_pkt_getuint32(ssh
);
5508 struct ssh_channel
*c
;
5510 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5511 if (!c
|| ((int)c
->remoteid
) == -1) {
5512 bombout((ssh
,"Received CHANNEL_CLOSE for %s channel %d\n",
5513 c ?
"half-open" : "nonexistent", i
));
5515 /* Do pre-close processing on the channel. */
5517 case CHAN_MAINSESSION
:
5518 break; /* nothing to see here, move along */
5520 if (c
->u
.x11
.s
!= NULL
)
5521 x11_close(c
->u
.x11
.s
);
5528 if (c
->u
.pfd
.s
!= NULL
)
5529 pfd_close(c
->u
.pfd
.s
);
5533 if (c
->closes
== 0) {
5534 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_CLOSE
);
5535 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5538 del234(ssh
->channels
, c
);
5539 bufchain_clear(&c
->v
.v2
.outbuffer
);
5543 * See if that was the last channel left open.
5545 if (count234(ssh
->channels
) == 0) {
5548 * We used to send SSH_MSG_DISCONNECT here,
5549 * because I'd believed that _every_ conforming
5550 * SSH2 connection had to end with a disconnect
5551 * being sent by at least one side; apparently
5552 * I was wrong and it's perfectly OK to
5553 * unceremoniously slam the connection shut
5554 * when you're done, and indeed OpenSSH feels
5555 * this is more polite than sending a
5556 * DISCONNECT. So now we don't.
5558 logevent("All channels closed. Disconnecting");
5559 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
5560 ssh2_pkt_adduint32(ssh
, SSH2_DISCONNECT_BY_APPLICATION
);
5561 ssh2_pkt_addstring(ssh
, "All open channels closed");
5562 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5565 ssh
->state
= SSH_STATE_CLOSED
;
5568 continue; /* remote sends close; ignore (FIXME) */
5569 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5570 unsigned i
= ssh2_pkt_getuint32(ssh
);
5571 struct ssh_channel
*c
;
5572 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5574 continue; /* nonexistent channel */
5575 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5577 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
5578 unsigned i
= ssh2_pkt_getuint32(ssh
);
5579 struct ssh_channel
*c
;
5580 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5582 continue; /* nonexistent channel */
5583 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
5584 continue; /* dunno why they're confirming this */
5585 c
->remoteid
= ssh2_pkt_getuint32(ssh
);
5586 c
->type
= CHAN_SOCKDATA
;
5587 c
->v
.v2
.remwindow
= ssh2_pkt_getuint32(ssh
);
5588 c
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32(ssh
);
5590 pfd_confirm(c
->u
.pfd
.s
);
5593 * We have a pending close on this channel,
5594 * which we decided on before the server acked
5595 * the channel open. So now we know the
5596 * remoteid, we can close it again.
5598 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_CLOSE
);
5599 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5602 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_OPEN_FAILURE
) {
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 failing this */
5611 logevent("Forwarded connection refused by server");
5613 pfd_close(c
->u
.pfd
.s
);
5615 del234(ssh
->channels
, c
);
5617 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_REQUEST
) {
5620 int typelen
, want_reply
;
5621 struct ssh_channel
*c
;
5623 localid
= ssh2_pkt_getuint32(ssh
);
5624 ssh2_pkt_getstring(ssh
, &type
, &typelen
);
5625 want_reply
= ssh2_pkt_getbool(ssh
);
5628 * First, check that the channel exists. Otherwise,
5629 * we can instantly disconnect with a rude message.
5631 c
= find234(ssh
->channels
, &localid
, ssh_channelfind
);
5634 sprintf(buf
, "Received channel request for nonexistent"
5635 " channel %d", localid
);
5637 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
5638 ssh2_pkt_adduint32(ssh
, SSH2_DISCONNECT_BY_APPLICATION
);
5639 ssh2_pkt_addstring(ssh
, buf
);
5640 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5642 connection_fatal("%s", buf
);
5643 ssh
->state
= SSH_STATE_CLOSED
;
5648 * Having got the channel number, we now look at
5649 * the request type string to see if it's something
5652 if (typelen
== 11 && !memcmp(type
, "exit-status", 11) &&
5653 c
== ssh
->mainchan
) {
5654 /* We recognise "exit-status" on the primary channel. */
5656 ssh
->exitcode
= ssh2_pkt_getuint32(ssh
);
5657 sprintf(buf
, "Server sent command exit status %d",
5661 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_SUCCESS
);
5662 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5667 * This is a channel request we don't know
5668 * about, so we now either ignore the request
5669 * or respond with CHANNEL_FAILURE, depending
5673 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_FAILURE
);
5674 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5678 } else if (ssh
->pktin
.type
== SSH2_MSG_GLOBAL_REQUEST
) {
5680 int typelen
, want_reply
;
5682 ssh2_pkt_getstring(ssh
, &type
, &typelen
);
5683 want_reply
= ssh2_pkt_getbool(ssh
);
5686 * We currently don't support any global requests
5687 * at all, so we either ignore the request or
5688 * respond with REQUEST_FAILURE, depending on
5692 ssh2_pkt_init(ssh
, SSH2_MSG_REQUEST_FAILURE
);
5695 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_OPEN
) {
5699 struct ssh_channel
*c
;
5700 unsigned remid
, winsize
, pktsize
;
5701 ssh2_pkt_getstring(ssh
, &type
, &typelen
);
5702 c
= smalloc(sizeof(struct ssh_channel
));
5705 remid
= ssh2_pkt_getuint32(ssh
);
5706 winsize
= ssh2_pkt_getuint32(ssh
);
5707 pktsize
= ssh2_pkt_getuint32(ssh
);
5709 if (typelen
== 3 && !memcmp(type
, "x11", 3)) {
5710 if (!ssh
->X11_fwd_enabled
)
5711 error
= "X11 forwarding is not enabled";
5712 else if (x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
,
5713 ssh
->x11auth
) != NULL
) {
5714 error
= "Unable to open an X11 connection";
5718 } else if (typelen
== 15 &&
5719 !memcmp(type
, "forwarded-tcpip", 15)) {
5720 struct ssh_rportfwd pf
, *realpf
;
5723 ssh2_pkt_getstring(ssh
, &dummy
, &dummylen
);/* skip address */
5724 pf
.sport
= ssh2_pkt_getuint32(ssh
);
5725 realpf
= find234(ssh
->rportfwds
, &pf
, NULL
);
5726 if (realpf
== NULL
) {
5727 error
= "Remote port is not recognised";
5729 char *e
= pfd_newconnect(&c
->u
.pfd
.s
, realpf
->dhost
,
5732 sprintf(buf
, "Received remote port open request for %s:%d",
5733 realpf
->dhost
, realpf
->dport
);
5736 sprintf(buf
, "Port open failed: %s", e
);
5738 error
= "Port open failed";
5740 logevent("Forwarded port opened successfully");
5741 c
->type
= CHAN_SOCKDATA
;
5744 } else if (typelen
== 22 &&
5745 !memcmp(type
, "auth-agent@openssh.com", 3)) {
5746 if (!ssh
->agentfwd_enabled
)
5747 error
= "Agent forwarding is not enabled";
5749 c
->type
= CHAN_AGENT
; /* identify channel type */
5750 c
->u
.a
.lensofar
= 0;
5753 error
= "Unsupported channel type requested";
5756 c
->remoteid
= remid
;
5758 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN_FAILURE
);
5759 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5760 ssh2_pkt_adduint32(ssh
, SSH2_OPEN_CONNECT_FAILED
);
5761 ssh2_pkt_addstring(ssh
, error
);
5762 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5766 c
->localid
= alloc_channel_id(ssh
);
5768 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5769 c
->v
.v2
.remwindow
= winsize
;
5770 c
->v
.v2
.remmaxpkt
= pktsize
;
5771 bufchain_init(&c
->v
.v2
.outbuffer
);
5772 add234(ssh
->channels
, c
);
5773 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
5774 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5775 ssh2_pkt_adduint32(ssh
, c
->localid
);
5776 ssh2_pkt_adduint32(ssh
, c
->v
.v2
.locwindow
);
5777 ssh2_pkt_adduint32(ssh
, 0x4000UL
); /* our max pkt size */
5781 bombout((ssh
,"Strange packet received: type %d", ssh
->pktin
.type
));
5786 * We have spare data. Add it to the channel buffer.
5788 ssh2_add_channel_data(ssh
->mainchan
, in
, inlen
);
5793 struct ssh_channel
*c
;
5795 * Try to send data on all channels if we can.
5797 for (i
= 0; NULL
!= (c
= index234(ssh
->channels
, i
)); i
++) {
5798 int bufsize
= ssh2_try_send(c
);
5801 case CHAN_MAINSESSION
:
5802 /* stdin need not receive an unthrottle
5803 * notification since it will be polled */
5806 x11_unthrottle(c
->u
.x11
.s
);
5809 /* agent sockets are request/response and need no
5810 * buffer management */
5813 pfd_unthrottle(c
->u
.pfd
.s
);
5825 * Handle the top-level SSH2 protocol.
5827 static void ssh2_protocol(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
5829 if (do_ssh2_transport(ssh
, in
, inlen
, ispkt
) == 0)
5831 do_ssh2_authconn(ssh
, in
, inlen
, ispkt
);
5835 * Called to set up the connection.
5837 * Returns an error message, or NULL on success.
5839 static char *ssh_init(void *frontend_handle
, void **backend_handle
,
5840 char *host
, int port
, char **realhost
, int nodelay
)
5845 ssh
= smalloc(sizeof(*ssh
));
5848 ssh
->v1_cipher_ctx
= NULL
;
5849 ssh
->crcda_ctx
= NULL
;
5850 ssh
->cscipher
= NULL
;
5851 ssh
->cs_cipher_ctx
= NULL
;
5852 ssh
->sccipher
= NULL
;
5853 ssh
->sc_cipher_ctx
= NULL
;
5855 ssh
->cs_mac_ctx
= NULL
;
5857 ssh
->sc_mac_ctx
= NULL
;
5859 ssh
->cs_comp_ctx
= NULL
;
5861 ssh
->sc_comp_ctx
= NULL
;
5863 ssh
->hostkey
= NULL
;
5865 ssh
->state
= SSH_STATE_PREPACKET
;
5866 ssh
->size_needed
= FALSE
;
5867 ssh
->eof_needed
= FALSE
;
5871 static const struct Packet empty
= { 0, 0, NULL
, NULL
, 0 };
5872 ssh
->pktin
= ssh
->pktout
= empty
;
5874 ssh
->deferred_send_data
= NULL
;
5875 ssh
->deferred_len
= 0;
5876 ssh
->deferred_size
= 0;
5877 ssh
->fallback_cmd
= 0;
5879 ssh
->x11auth
= NULL
;
5880 ssh
->v1_compressing
= FALSE
;
5881 ssh
->v2_outgoing_sequence
= 0;
5882 ssh
->ssh1_rdpkt_crstate
= 0;
5883 ssh
->ssh2_rdpkt_crstate
= 0;
5884 ssh
->do_ssh_init_crstate
= 0;
5885 ssh
->ssh_gotdata_crstate
= 0;
5886 ssh
->ssh1_protocol_crstate
= 0;
5887 ssh
->do_ssh1_login_crstate
= 0;
5888 ssh
->do_ssh2_transport_crstate
= 0;
5889 ssh
->do_ssh2_authconn_crstate
= 0;
5890 ssh
->do_ssh_init_state
= NULL
;
5891 ssh
->do_ssh1_login_state
= NULL
;
5892 ssh
->do_ssh2_transport_state
= NULL
;
5893 ssh
->do_ssh2_authconn_state
= NULL
;
5894 ssh
->mainchan
= NULL
;
5895 ssh
->throttled_all
= 0;
5896 ssh
->v1_stdout_throttling
= 0;
5898 *backend_handle
= ssh
;
5901 if (crypto_startup() == 0)
5902 return "Microsoft high encryption pack not installed!";
5905 ssh
->frontend
= frontend_handle
;
5906 ssh
->term_width
= cfg
.width
;
5907 ssh
->term_height
= cfg
.height
;
5912 ssh
->v1_throttle_count
= 0;
5913 ssh
->overall_bufsize
= 0;
5914 ssh
->fallback_cmd
= 0;
5916 p
= connect_to_host(ssh
, host
, port
, realhost
, nodelay
);
5924 * Called to send data down the Telnet connection.
5926 static int ssh_send(void *handle
, char *buf
, int len
)
5928 Ssh ssh
= (Ssh
) handle
;
5930 if (ssh
== NULL
|| ssh
->s
== NULL
|| ssh
->protocol
== NULL
)
5933 ssh
->protocol(ssh
, buf
, len
, 0);
5935 return ssh_sendbuffer(ssh
);
5939 * Called to query the current amount of buffered stdin data.
5941 static int ssh_sendbuffer(void *handle
)
5943 Ssh ssh
= (Ssh
) handle
;
5946 if (ssh
== NULL
|| ssh
->s
== NULL
|| ssh
->protocol
== NULL
)
5950 * If the SSH socket itself has backed up, add the total backup
5951 * size on that to any individual buffer on the stdin channel.
5954 if (ssh
->throttled_all
)
5955 override_value
= ssh
->overall_bufsize
;
5957 if (ssh
->version
== 1) {
5958 return override_value
;
5959 } else if (ssh
->version
== 2) {
5960 if (!ssh
->mainchan
|| ssh
->mainchan
->closes
> 0)
5961 return override_value
;
5963 return (override_value
+
5964 bufchain_size(&ssh
->mainchan
->v
.v2
.outbuffer
));
5971 * Called to set the size of the window from SSH's POV.
5973 static void ssh_size(void *handle
, int width
, int height
)
5975 Ssh ssh
= (Ssh
) handle
;
5977 ssh
->term_width
= width
;
5978 ssh
->term_height
= height
;
5980 switch (ssh
->state
) {
5981 case SSH_STATE_BEFORE_SIZE
:
5982 case SSH_STATE_PREPACKET
:
5983 case SSH_STATE_CLOSED
:
5984 break; /* do nothing */
5985 case SSH_STATE_INTERMED
:
5986 ssh
->size_needed
= TRUE
; /* buffer for later */
5988 case SSH_STATE_SESSION
:
5990 if (ssh
->version
== 1) {
5991 send_packet(ssh
, SSH1_CMSG_WINDOW_SIZE
,
5992 PKT_INT
, ssh
->term_height
,
5993 PKT_INT
, ssh
->term_width
,
5994 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
5996 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5997 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
5998 ssh2_pkt_addstring(ssh
, "window-change");
5999 ssh2_pkt_addbool(ssh
, 0);
6000 ssh2_pkt_adduint32(ssh
, ssh
->term_width
);
6001 ssh2_pkt_adduint32(ssh
, ssh
->term_height
);
6002 ssh2_pkt_adduint32(ssh
, 0);
6003 ssh2_pkt_adduint32(ssh
, 0);
6012 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6013 * can send an EOF and collect resulting output (e.g. `plink
6016 static void ssh_special(void *handle
, Telnet_Special code
)
6018 Ssh ssh
= (Ssh
) handle
;
6020 if (code
== TS_EOF
) {
6021 if (ssh
->state
!= SSH_STATE_SESSION
) {
6023 * Buffer the EOF in case we are pre-SESSION, so we can
6024 * send it as soon as we reach SESSION.
6027 ssh
->eof_needed
= TRUE
;
6030 if (ssh
->version
== 1) {
6031 send_packet(ssh
, SSH1_CMSG_EOF
, PKT_END
);
6033 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_EOF
);
6034 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
6037 logevent("Sent EOF message");
6038 } else if (code
== TS_PING
) {
6039 if (ssh
->state
== SSH_STATE_CLOSED
6040 || ssh
->state
== SSH_STATE_PREPACKET
) return;
6041 if (ssh
->version
== 1) {
6042 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
))
6043 send_packet(ssh
, SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
6045 ssh2_pkt_init(ssh
, SSH2_MSG_IGNORE
);
6046 ssh2_pkt_addstring_start(ssh
);
6054 void *new_sock_channel(void *handle
, Socket s
)
6056 Ssh ssh
= (Ssh
) handle
;
6057 struct ssh_channel
*c
;
6058 c
= smalloc(sizeof(struct ssh_channel
));
6062 c
->remoteid
= -1; /* to be set when open confirmed */
6063 c
->localid
= alloc_channel_id(ssh
);
6065 c
->type
= CHAN_SOCKDATA_DORMANT
;/* identify channel type */
6067 bufchain_init(&c
->v
.v2
.outbuffer
);
6068 add234(ssh
->channels
, c
);
6074 * This is called when stdout/stderr (the entity to which
6075 * from_backend sends data) manages to clear some backlog.
6077 void ssh_unthrottle(void *handle
, int bufsize
)
6079 Ssh ssh
= (Ssh
) handle
;
6080 if (ssh
->version
== 1) {
6081 if (ssh
->v1_stdout_throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
6082 ssh
->v1_stdout_throttling
= 0;
6083 ssh1_throttle(ssh
, -1);
6086 if (ssh
->mainchan
&& ssh
->mainchan
->closes
== 0)
6087 ssh2_set_window(ssh
->mainchan
, OUR_V2_WINSIZE
- bufsize
);
6091 void ssh_send_port_open(void *channel
, char *hostname
, int port
, char *org
)
6093 struct ssh_channel
*c
= (struct ssh_channel
*)channel
;
6097 sprintf(buf
, "Opening forwarded connection to %.512s:%d", hostname
, port
);
6100 if (ssh
->version
== 1) {
6101 send_packet(ssh
, SSH1_MSG_PORT_OPEN
,
6102 PKT_INT
, c
->localid
,
6105 //PKT_STR, <org:orgport>,
6108 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN
);
6109 ssh2_pkt_addstring(ssh
, "direct-tcpip");
6110 ssh2_pkt_adduint32(ssh
, c
->localid
);
6111 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
6112 ssh2_pkt_adduint32(ssh
, c
->v
.v2
.locwindow
);/* our window size */
6113 ssh2_pkt_adduint32(ssh
, 0x4000UL
); /* our max pkt size */
6114 ssh2_pkt_addstring(ssh
, hostname
);
6115 ssh2_pkt_adduint32(ssh
, port
);
6117 * We make up values for the originator data; partly it's
6118 * too much hassle to keep track, and partly I'm not
6119 * convinced the server should be told details like that
6120 * about my local network configuration.
6122 ssh2_pkt_addstring(ssh
, "client-side-connection");
6123 ssh2_pkt_adduint32(ssh
, 0);
6129 static Socket
ssh_socket(void *handle
)
6131 Ssh ssh
= (Ssh
) handle
;
6135 static int ssh_sendok(void *handle
)
6137 Ssh ssh
= (Ssh
) handle
;
6138 return ssh
->send_ok
;
6141 static int ssh_ldisc(void *handle
, int option
)
6143 Ssh ssh
= (Ssh
) handle
;
6144 if (option
== LD_ECHO
)
6145 return ssh
->echoing
;
6146 if (option
== LD_EDIT
)
6147 return ssh
->editing
;
6151 static void ssh_provide_ldisc(void *handle
, void *ldisc
)
6153 Ssh ssh
= (Ssh
) handle
;
6157 static void ssh_provide_logctx(void *handle
, void *logctx
)
6159 Ssh ssh
= (Ssh
) handle
;
6160 ssh
->logctx
= logctx
;
6163 static int ssh_return_exitcode(void *handle
)
6165 Ssh ssh
= (Ssh
) handle
;
6166 return ssh
->exitcode
;
6170 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6171 * that fails. This variable is the means by which scp.c can reach
6172 * into the SSH code and find out which one it got.
6174 extern int ssh_fallback_cmd(void *handle
)
6176 Ssh ssh
= (Ssh
) handle
;
6177 return ssh
->fallback_cmd
;
6180 Backend ssh_backend
= {
6187 ssh_return_exitcode
,