17 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
18 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
19 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
20 #define SSH1_CMSG_USER 4 /* 0x4 */
21 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
22 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
23 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
24 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
25 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
26 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
27 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
28 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
29 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
30 #define SSH1_SMSG_FAILURE 15 /* 0xf */
31 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
32 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
33 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
34 #define SSH1_CMSG_EOF 19 /* 0x13 */
35 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
36 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
37 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
38 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
39 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
40 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
41 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
42 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
43 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
44 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
45 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
46 #define SSH1_MSG_IGNORE 32 /* 0x20 */
47 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
48 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
49 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
50 #define SSH1_MSG_DEBUG 36 /* 0x24 */
51 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
52 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
53 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
54 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
55 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
56 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
57 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
59 #define SSH1_AUTH_TIS 5 /* 0x5 */
60 #define SSH1_AUTH_CCARD 16 /* 0x10 */
62 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
63 /* Mask for protoflags we will echo back to server if seen */
64 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
66 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
67 #define SSH2_MSG_IGNORE 2 /* 0x2 */
68 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
69 #define SSH2_MSG_DEBUG 4 /* 0x4 */
70 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
71 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
72 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
73 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
74 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
75 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
76 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
77 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
78 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
79 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
80 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
81 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
82 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
83 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
84 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
85 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
86 #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
87 #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
88 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
89 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
90 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
91 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
92 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
93 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
94 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
95 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
96 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
97 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
98 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
99 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
100 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
101 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
104 * Packet type contexts, so that ssh2_pkt_type can correctly decode
105 * the ambiguous type numbers back into the correct type strings.
107 #define SSH2_PKTCTX_DHGROUP1 0x0001
108 #define SSH2_PKTCTX_DHGEX 0x0002
109 #define SSH2_PKTCTX_PUBLICKEY 0x0010
110 #define SSH2_PKTCTX_PASSWORD 0x0020
111 #define SSH2_PKTCTX_KBDINTER 0x0040
112 #define SSH2_PKTCTX_AUTH_MASK 0x00F0
114 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
115 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
116 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
117 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
118 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
119 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
120 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
121 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
122 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
123 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
124 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
125 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
126 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
127 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
128 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
130 static const char *const ssh2_disconnect_reasons
[] = {
132 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
133 "SSH_DISCONNECT_PROTOCOL_ERROR",
134 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
135 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
136 "SSH_DISCONNECT_MAC_ERROR",
137 "SSH_DISCONNECT_COMPRESSION_ERROR",
138 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
139 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
140 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
141 "SSH_DISCONNECT_CONNECTION_LOST",
142 "SSH_DISCONNECT_BY_APPLICATION",
143 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
144 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
145 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
146 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
149 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
150 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
151 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
152 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
154 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
157 * Various remote-bug flags.
159 #define BUG_CHOKES_ON_SSH1_IGNORE 1
160 #define BUG_SSH2_HMAC 2
161 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
162 #define BUG_CHOKES_ON_RSA 8
163 #define BUG_SSH2_RSA_PADDING 16
164 #define BUG_SSH2_DERIVEKEY 32
165 #define BUG_SSH2_DH_GEX 64
167 #define translate(x) if (type == x) return #x
168 #define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
169 char *ssh1_pkt_type(int type
)
171 translate(SSH1_MSG_DISCONNECT
);
172 translate(SSH1_SMSG_PUBLIC_KEY
);
173 translate(SSH1_CMSG_SESSION_KEY
);
174 translate(SSH1_CMSG_USER
);
175 translate(SSH1_CMSG_AUTH_RSA
);
176 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE
);
177 translate(SSH1_CMSG_AUTH_RSA_RESPONSE
);
178 translate(SSH1_CMSG_AUTH_PASSWORD
);
179 translate(SSH1_CMSG_REQUEST_PTY
);
180 translate(SSH1_CMSG_WINDOW_SIZE
);
181 translate(SSH1_CMSG_EXEC_SHELL
);
182 translate(SSH1_CMSG_EXEC_CMD
);
183 translate(SSH1_SMSG_SUCCESS
);
184 translate(SSH1_SMSG_FAILURE
);
185 translate(SSH1_CMSG_STDIN_DATA
);
186 translate(SSH1_SMSG_STDOUT_DATA
);
187 translate(SSH1_SMSG_STDERR_DATA
);
188 translate(SSH1_CMSG_EOF
);
189 translate(SSH1_SMSG_EXIT_STATUS
);
190 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
);
191 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE
);
192 translate(SSH1_MSG_CHANNEL_DATA
);
193 translate(SSH1_MSG_CHANNEL_CLOSE
);
194 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
);
195 translate(SSH1_SMSG_X11_OPEN
);
196 translate(SSH1_CMSG_PORT_FORWARD_REQUEST
);
197 translate(SSH1_MSG_PORT_OPEN
);
198 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING
);
199 translate(SSH1_SMSG_AGENT_OPEN
);
200 translate(SSH1_MSG_IGNORE
);
201 translate(SSH1_CMSG_EXIT_CONFIRMATION
);
202 translate(SSH1_CMSG_X11_REQUEST_FORWARDING
);
203 translate(SSH1_CMSG_AUTH_RHOSTS_RSA
);
204 translate(SSH1_MSG_DEBUG
);
205 translate(SSH1_CMSG_REQUEST_COMPRESSION
);
206 translate(SSH1_CMSG_AUTH_TIS
);
207 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE
);
208 translate(SSH1_CMSG_AUTH_TIS_RESPONSE
);
209 translate(SSH1_CMSG_AUTH_CCARD
);
210 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE
);
211 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE
);
214 char *ssh2_pkt_type(int pkt_ctx
, int type
)
216 translate(SSH2_MSG_DISCONNECT
);
217 translate(SSH2_MSG_IGNORE
);
218 translate(SSH2_MSG_UNIMPLEMENTED
);
219 translate(SSH2_MSG_DEBUG
);
220 translate(SSH2_MSG_SERVICE_REQUEST
);
221 translate(SSH2_MSG_SERVICE_ACCEPT
);
222 translate(SSH2_MSG_KEXINIT
);
223 translate(SSH2_MSG_NEWKEYS
);
224 translatec(SSH2_MSG_KEXDH_INIT
, SSH2_PKTCTX_DHGROUP1
);
225 translatec(SSH2_MSG_KEXDH_REPLY
, SSH2_PKTCTX_DHGROUP1
);
226 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST
, SSH2_PKTCTX_DHGEX
);
227 translatec(SSH2_MSG_KEX_DH_GEX_GROUP
, SSH2_PKTCTX_DHGEX
);
228 translatec(SSH2_MSG_KEX_DH_GEX_INIT
, SSH2_PKTCTX_DHGEX
);
229 translatec(SSH2_MSG_KEX_DH_GEX_REPLY
, SSH2_PKTCTX_DHGEX
);
230 translate(SSH2_MSG_USERAUTH_REQUEST
);
231 translate(SSH2_MSG_USERAUTH_FAILURE
);
232 translate(SSH2_MSG_USERAUTH_SUCCESS
);
233 translate(SSH2_MSG_USERAUTH_BANNER
);
234 translatec(SSH2_MSG_USERAUTH_PK_OK
, SSH2_PKTCTX_PUBLICKEY
);
235 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ
, SSH2_PKTCTX_PASSWORD
);
236 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST
, SSH2_PKTCTX_KBDINTER
);
237 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE
, SSH2_PKTCTX_KBDINTER
);
238 translate(SSH2_MSG_GLOBAL_REQUEST
);
239 translate(SSH2_MSG_REQUEST_SUCCESS
);
240 translate(SSH2_MSG_REQUEST_FAILURE
);
241 translate(SSH2_MSG_CHANNEL_OPEN
);
242 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
243 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE
);
244 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
245 translate(SSH2_MSG_CHANNEL_DATA
);
246 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA
);
247 translate(SSH2_MSG_CHANNEL_EOF
);
248 translate(SSH2_MSG_CHANNEL_CLOSE
);
249 translate(SSH2_MSG_CHANNEL_REQUEST
);
250 translate(SSH2_MSG_CHANNEL_SUCCESS
);
251 translate(SSH2_MSG_CHANNEL_FAILURE
);
257 #define GET_32BIT(cp) \
258 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
259 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
260 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
261 ((unsigned long)(unsigned char)(cp)[3]))
263 #define PUT_32BIT(cp, value) { \
264 (cp)[0] = (unsigned char)((value) >> 24); \
265 (cp)[1] = (unsigned char)((value) >> 16); \
266 (cp)[2] = (unsigned char)((value) >> 8); \
267 (cp)[3] = (unsigned char)(value); }
269 enum { PKT_END
, PKT_INT
, PKT_CHAR
, PKT_DATA
, PKT_STR
, PKT_BIGNUM
};
271 /* Coroutine mechanics for the sillier bits of the code */
272 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
275 if (!ssh->t) ssh->t = smalloc(sizeof(struct t)); \
277 #define crFinish(z) } *crLine = 0; return (z); }
278 #define crFinishV } *crLine = 0; return; }
279 #define crReturn(z) \
281 *crLine =__LINE__; return (z); case __LINE__:;\
285 *crLine=__LINE__; return; case __LINE__:;\
287 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
288 #define crStopV do{ *crLine = 0; return; }while(0)
289 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
290 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
292 typedef struct ssh_tag
*Ssh
;
294 extern char *x11_init(Socket
*, char *, void *, void *);
295 extern void x11_close(Socket
);
296 extern int x11_send(Socket
, char *, int);
297 extern void *x11_invent_auth(char *, int, char *, int);
298 extern void x11_unthrottle(Socket s
);
299 extern void x11_override_throttle(Socket s
, int enable
);
301 extern char *pfd_newconnect(Socket
* s
, char *hostname
, int port
, void *c
);
302 extern char *pfd_addforward(char *desthost
, int destport
, char *srcaddr
,
303 int port
, void *backhandle
);
304 extern void pfd_close(Socket s
);
305 extern int pfd_send(Socket s
, char *data
, int len
);
306 extern void pfd_confirm(Socket s
);
307 extern void pfd_unthrottle(Socket s
);
308 extern void pfd_override_throttle(Socket s
, int enable
);
310 static void ssh2_pkt_init(Ssh
, int pkt_type
);
311 static void ssh2_pkt_addbool(Ssh
, unsigned char value
);
312 static void ssh2_pkt_adduint32(Ssh
, unsigned long value
);
313 static void ssh2_pkt_addstring_start(Ssh
);
314 static void ssh2_pkt_addstring_str(Ssh
, char *data
);
315 static void ssh2_pkt_addstring_data(Ssh
, char *data
, int len
);
316 static void ssh2_pkt_addstring(Ssh
, char *data
);
317 static char *ssh2_mpint_fmt(Bignum b
, int *len
);
318 static void ssh2_pkt_addmp(Ssh
, Bignum b
);
319 static int ssh2_pkt_construct(Ssh
);
320 static void ssh2_pkt_send(Ssh
);
323 * Buffer management constants. There are several of these for
324 * various different purposes:
326 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
327 * on a local data stream before we throttle the whole SSH
328 * connection (in SSH1 only). Throttling the whole connection is
329 * pretty drastic so we set this high in the hope it won't
332 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
333 * on the SSH connection itself before we defensively throttle
334 * _all_ local data streams. This is pretty drastic too (though
335 * thankfully unlikely in SSH2 since the window mechanism should
336 * ensure that the server never has any need to throttle its end
337 * of the connection), so we set this high as well.
339 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
343 #define SSH1_BUFFER_LIMIT 32768
344 #define SSH_MAX_BACKLOG 32768
345 #define OUR_V2_WINSIZE 16384
347 const static struct ssh_kex
*kex_algs
[] = {
348 &ssh_diffiehellman_gex
,
352 const static struct ssh_signkey
*hostkey_algs
[] = { &ssh_rsa
, &ssh_dss
};
354 static void *nullmac_make_context(void)
358 static void nullmac_free_context(void *handle
)
361 static void nullmac_key(void *handle
, unsigned char *key
)
364 static void nullmac_generate(void *handle
, unsigned char *blk
, int len
,
368 static int nullmac_verify(void *handle
, unsigned char *blk
, int len
,
373 const static struct ssh_mac ssh_mac_none
= {
374 nullmac_make_context
, nullmac_free_context
, nullmac_key
,
375 nullmac_generate
, nullmac_verify
, "none", 0
377 const static struct ssh_mac
*macs
[] = {
378 &ssh_sha1
, &ssh_md5
, &ssh_mac_none
380 const static struct ssh_mac
*buggymacs
[] = {
381 &ssh_sha1_buggy
, &ssh_md5
, &ssh_mac_none
384 static void *ssh_comp_none_init(void)
388 static void ssh_comp_none_cleanup(void *handle
)
391 static int ssh_comp_none_block(void *handle
, unsigned char *block
, int len
,
392 unsigned char **outblock
, int *outlen
)
396 static int ssh_comp_none_disable(void *handle
)
400 const static struct ssh_compress ssh_comp_none
= {
402 ssh_comp_none_init
, ssh_comp_none_cleanup
, ssh_comp_none_block
,
403 ssh_comp_none_init
, ssh_comp_none_cleanup
, ssh_comp_none_block
,
404 ssh_comp_none_disable
, NULL
406 extern const struct ssh_compress ssh_zlib
;
407 const static struct ssh_compress
*compressions
[] = {
408 &ssh_zlib
, &ssh_comp_none
411 enum { /* channel types */
416 CHAN_SOCKDATA_DORMANT
/* one the remote hasn't confirmed */
420 * 2-3-4 tree storing channels.
423 Ssh ssh
; /* pointer back to main context */
424 unsigned remoteid
, localid
;
427 * In SSH1, this value contains four bits:
429 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
430 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
431 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
432 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
434 * A channel is completely finished with when all four bits are set.
438 struct ssh1_data_channel
{
441 struct ssh2_data_channel
{
443 unsigned remwindow
, remmaxpkt
;
448 struct ssh_agent_channel
{
449 unsigned char *message
;
450 unsigned char msglen
[4];
451 int lensofar
, totallen
;
453 struct ssh_x11_channel
{
456 struct ssh_pfd_channel
{
463 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
464 * 2 use this structure in different ways, reflecting SSH 2's
465 * altogether saner approach to port forwarding.
467 * In SSH 1, you arrange a remote forwarding by sending the server
468 * the remote port number, and the local destination host:port.
469 * When a connection comes in, the server sends you back that
470 * host:port pair, and you connect to it. This is a ready-made
471 * security hole if you're not on the ball: a malicious server
472 * could send you back _any_ host:port pair, so if you trustingly
473 * connect to the address it gives you then you've just opened the
474 * entire inside of your corporate network just by connecting
475 * through it to a dodgy SSH server. Hence, we must store a list of
476 * host:port pairs we _are_ trying to forward to, and reject a
477 * connection request from the server if it's not in the list.
479 * In SSH 2, each side of the connection minds its own business and
480 * doesn't send unnecessary information to the other. You arrange a
481 * remote forwarding by sending the server just the remote port
482 * number. When a connection comes in, the server tells you which
483 * of its ports was connected to; and _you_ have to remember what
484 * local host:port pair went with that port number.
486 * Hence: in SSH 1 this structure stores host:port pairs we intend
487 * to allow connections to, and is indexed by those host:port
488 * pairs. In SSH 2 it stores a mapping from source port to
489 * destination host:port pair, and is indexed by source port.
491 struct ssh_rportfwd
{
492 unsigned sport
, dport
;
505 static void ssh1_protocol(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
);
506 static void ssh2_protocol(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
);
507 static void ssh_size(void *handle
, int width
, int height
);
508 static void ssh_special(void *handle
, Telnet_Special
);
509 static int ssh2_try_send(struct ssh_channel
*c
);
510 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
, int len
);
511 static void ssh_throttle_all(Ssh ssh
, int enable
, int bufsize
);
512 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
);
513 static int ssh_sendbuffer(void *handle
);
515 struct rdpkt1_state_tag
{
516 long len
, pad
, biglen
, to_read
;
517 unsigned long realcrc
, gotcrc
;
523 struct rdpkt2_state_tag
{
524 long len
, pad
, payload
, packetlen
, maclen
;
527 unsigned long incoming_sequence
;
531 const struct plug_function_table
*fn
;
532 /* the above field _must_ be first in the structure */
534 SHA_State exhash
, exhashbase
;
541 unsigned char session_key
[32];
543 int v1_remote_protoflags
;
544 int v1_local_protoflags
;
545 int agentfwd_enabled
;
548 const struct ssh_cipher
*cipher
;
551 const struct ssh2_cipher
*cscipher
, *sccipher
;
552 void *cs_cipher_ctx
, *sc_cipher_ctx
;
553 const struct ssh_mac
*csmac
, *scmac
;
554 void *cs_mac_ctx
, *sc_mac_ctx
;
555 const struct ssh_compress
*cscomp
, *sccomp
;
556 void *cs_comp_ctx
, *sc_comp_ctx
;
557 const struct ssh_kex
*kex
;
558 const struct ssh_signkey
*hostkey
;
559 unsigned char v2_session_id
[20];
565 int echoing
, editing
;
569 int term_width
, term_height
;
571 tree234
*channels
; /* indexed by local id */
572 struct ssh_channel
*mainchan
; /* primary session channel */
579 SSH_STATE_BEFORE_SIZE
,
585 int size_needed
, eof_needed
;
588 struct Packet pktout
;
589 unsigned char *deferred_send_data
;
590 int deferred_len
, deferred_size
;
593 * Gross hack: pscp will try to start SFTP but fall back to
594 * scp1 if that fails. This variable is the means by which
595 * scp.c can reach into the SSH code and find out which one it
601 * Used for username and password input.
603 char *userpass_input_buffer
;
604 int userpass_input_buflen
;
605 int userpass_input_bufpos
;
606 int userpass_input_echo
;
608 char *portfwd_strptr
;
614 int v1_throttle_count
;
617 int v1_stdout_throttling
;
618 int v2_outgoing_sequence
;
620 int ssh1_rdpkt_crstate
;
621 int ssh2_rdpkt_crstate
;
622 int do_ssh_init_crstate
;
623 int ssh_gotdata_crstate
;
624 int ssh1_protocol_crstate
;
625 int do_ssh1_login_crstate
;
626 int do_ssh2_transport_crstate
;
627 int do_ssh2_authconn_crstate
;
629 void *do_ssh_init_state
;
630 void *do_ssh1_login_state
;
631 void *do_ssh2_transport_state
;
632 void *do_ssh2_authconn_state
;
634 struct rdpkt1_state_tag rdpkt1_state
;
635 struct rdpkt2_state_tag rdpkt2_state
;
637 void (*protocol
) (Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
);
638 int (*s_rdpkt
) (Ssh ssh
, unsigned char **data
, int *datalen
);
641 #define logevent(s) do { \
642 logevent(ssh->frontend, s); \
643 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) { \
644 fprintf(stderr, "%s\n", s); \
649 /* logevent, only printf-formatted. */
650 void logeventf(Ssh ssh
, char *fmt
, ...)
656 buf
= dupvprintf(fmt
, ap
);
659 if ((flags
& FLAG_STDERR
) && (flags
& FLAG_VERBOSE
)) {
660 fprintf(stderr
, "%s\n", buf
);
666 #define bombout(msg) ( ssh->state = SSH_STATE_CLOSED, \
667 (ssh->s ? sk_close(ssh->s), ssh->s = NULL : 0), \
668 logeventf msg, connection_fatal msg )
670 static int ssh_channelcmp(void *av
, void *bv
)
672 struct ssh_channel
*a
= (struct ssh_channel
*) av
;
673 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
674 if (a
->localid
< b
->localid
)
676 if (a
->localid
> b
->localid
)
680 static int ssh_channelfind(void *av
, void *bv
)
682 unsigned *a
= (unsigned *) av
;
683 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
691 static int ssh_rportcmp_ssh1(void *av
, void *bv
)
693 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
694 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
696 if ( (i
= strcmp(a
->dhost
, b
->dhost
)) != 0)
697 return i
< 0 ?
-1 : +1;
698 if (a
->dport
> b
->dport
)
700 if (a
->dport
< b
->dport
)
705 static int ssh_rportcmp_ssh2(void *av
, void *bv
)
707 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
708 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
710 if (a
->sport
> b
->sport
)
712 if (a
->sport
< b
->sport
)
717 static int alloc_channel_id(Ssh ssh
)
719 const unsigned CHANNEL_NUMBER_OFFSET
= 256;
720 unsigned low
, high
, mid
;
722 struct ssh_channel
*c
;
725 * First-fit allocation of channel numbers: always pick the
726 * lowest unused one. To do this, binary-search using the
727 * counted B-tree to find the largest channel ID which is in a
728 * contiguous sequence from the beginning. (Precisely
729 * everything in that sequence must have ID equal to its tree
730 * index plus CHANNEL_NUMBER_OFFSET.)
732 tsize
= count234(ssh
->channels
);
736 while (high
- low
> 1) {
737 mid
= (high
+ low
) / 2;
738 c
= index234(ssh
->channels
, mid
);
739 if (c
->localid
== mid
+ CHANNEL_NUMBER_OFFSET
)
740 low
= mid
; /* this one is fine */
742 high
= mid
; /* this one is past it */
745 * Now low points to either -1, or the tree index of the
746 * largest ID in the initial sequence.
749 unsigned i
= low
+ 1 + CHANNEL_NUMBER_OFFSET
;
750 assert(NULL
== find234(ssh
->channels
, &i
, ssh_channelfind
));
752 return low
+ 1 + CHANNEL_NUMBER_OFFSET
;
755 static void c_write(Ssh ssh
, char *buf
, int len
)
757 if ((flags
& FLAG_STDERR
)) {
759 for (i
= 0; i
< len
; i
++)
761 fputc(buf
[i
], stderr
);
764 from_backend(ssh
->frontend
, 1, buf
, len
);
767 static void c_write_untrusted(Ssh ssh
, char *buf
, int len
)
770 for (i
= 0; i
< len
; i
++) {
772 c_write(ssh
, "\r\n", 2);
773 else if ((buf
[i
] & 0x60) || (buf
[i
] == '\r'))
774 c_write(ssh
, buf
+ i
, 1);
778 static void c_write_str(Ssh ssh
, char *buf
)
780 c_write(ssh
, buf
, strlen(buf
));
784 * Collect incoming data in the incoming packet buffer.
785 * Decipher and verify the packet when it is completely read.
786 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
787 * Update the *data and *datalen variables.
788 * Return the additional nr of bytes needed, or 0 when
789 * a complete packet is available.
791 static int ssh1_rdpkt(Ssh ssh
, unsigned char **data
, int *datalen
)
793 struct rdpkt1_state_tag
*st
= &ssh
->rdpkt1_state
;
795 crBegin(ssh
->ssh1_rdpkt_crstate
);
800 ssh
->pktin
.length
= 0;
802 for (st
->i
= st
->len
= 0; st
->i
< 4; st
->i
++) {
803 while ((*datalen
) == 0)
805 st
->len
= (st
->len
<< 8) + **data
;
806 (*data
)++, (*datalen
)--;
809 st
->pad
= 8 - (st
->len
% 8);
810 st
->biglen
= st
->len
+ st
->pad
;
811 ssh
->pktin
.length
= st
->len
- 5;
813 if (ssh
->pktin
.maxlen
< st
->biglen
) {
814 ssh
->pktin
.maxlen
= st
->biglen
;
815 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
, st
->biglen
+ APIEXTRA
);
818 st
->to_read
= st
->biglen
;
819 st
->p
= ssh
->pktin
.data
;
820 while (st
->to_read
> 0) {
821 st
->chunk
= st
->to_read
;
822 while ((*datalen
) == 0)
823 crReturn(st
->to_read
);
824 if (st
->chunk
> (*datalen
))
825 st
->chunk
= (*datalen
);
826 memcpy(st
->p
, *data
, st
->chunk
);
828 *datalen
-= st
->chunk
;
830 st
->to_read
-= st
->chunk
;
833 if (ssh
->cipher
&& detect_attack(ssh
->crcda_ctx
, ssh
->pktin
.data
,
835 bombout((ssh
,"Network attack (CRC compensation) detected!"));
840 ssh
->cipher
->decrypt(ssh
->v1_cipher_ctx
, ssh
->pktin
.data
, st
->biglen
);
842 st
->realcrc
= crc32(ssh
->pktin
.data
, st
->biglen
- 4);
843 st
->gotcrc
= GET_32BIT(ssh
->pktin
.data
+ st
->biglen
- 4);
844 if (st
->gotcrc
!= st
->realcrc
) {
845 bombout((ssh
,"Incorrect CRC received on packet"));
849 ssh
->pktin
.body
= ssh
->pktin
.data
+ st
->pad
+ 1;
851 if (ssh
->v1_compressing
) {
852 unsigned char *decompblk
;
854 zlib_decompress_block(ssh
->sc_comp_ctx
,
855 ssh
->pktin
.body
- 1, ssh
->pktin
.length
+ 1,
856 &decompblk
, &decomplen
);
858 if (ssh
->pktin
.maxlen
< st
->pad
+ decomplen
) {
859 ssh
->pktin
.maxlen
= st
->pad
+ decomplen
;
860 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
,
861 ssh
->pktin
.maxlen
+ APIEXTRA
);
862 ssh
->pktin
.body
= ssh
->pktin
.data
+ st
->pad
+ 1;
865 memcpy(ssh
->pktin
.body
- 1, decompblk
, decomplen
);
867 ssh
->pktin
.length
= decomplen
- 1;
870 ssh
->pktin
.type
= ssh
->pktin
.body
[-1];
873 log_packet(ssh
->logctx
,
874 PKT_INCOMING
, ssh
->pktin
.type
,
875 ssh1_pkt_type(ssh
->pktin
.type
),
876 ssh
->pktin
.body
, ssh
->pktin
.length
);
878 if (ssh
->pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
879 ssh
->pktin
.type
== SSH1_SMSG_STDERR_DATA
||
880 ssh
->pktin
.type
== SSH1_MSG_DEBUG
||
881 ssh
->pktin
.type
== SSH1_SMSG_AUTH_TIS_CHALLENGE
||
882 ssh
->pktin
.type
== SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
883 long stringlen
= GET_32BIT(ssh
->pktin
.body
);
884 if (stringlen
+ 4 != ssh
->pktin
.length
) {
885 bombout((ssh
,"Received data packet with bogus string length"));
890 if (ssh
->pktin
.type
== SSH1_MSG_DEBUG
) {
891 /* log debug message */
893 int stringlen
= GET_32BIT(ssh
->pktin
.body
);
894 strcpy(buf
, "Remote debug message: ");
897 memcpy(buf
+ 8, ssh
->pktin
.body
+ 4, stringlen
);
898 buf
[8 + stringlen
] = '\0';
901 } else if (ssh
->pktin
.type
== SSH1_MSG_IGNORE
) {
906 if (ssh
->pktin
.type
== SSH1_MSG_DISCONNECT
) {
907 /* log reason code in disconnect message */
909 unsigned msglen
= GET_32BIT(ssh
->pktin
.body
);
911 strcpy(buf
, "Remote sent disconnect: ");
912 nowlen
= strlen(buf
);
913 if (msglen
> sizeof(buf
) - nowlen
- 1)
914 msglen
= sizeof(buf
) - nowlen
- 1;
915 memcpy(buf
+ nowlen
, ssh
->pktin
.body
+ 4, msglen
);
916 buf
[nowlen
+ msglen
] = '\0';
917 /* logevent(buf); (this is now done within the bombout macro) */
918 bombout((ssh
,"Server sent disconnect message:\n\"%s\"", buf
+nowlen
));
925 static int ssh2_rdpkt(Ssh ssh
, unsigned char **data
, int *datalen
)
927 struct rdpkt2_state_tag
*st
= &ssh
->rdpkt2_state
;
929 crBegin(ssh
->ssh2_rdpkt_crstate
);
933 ssh
->pktin
.length
= 0;
935 st
->cipherblk
= ssh
->sccipher
->blksize
;
938 if (st
->cipherblk
< 8)
941 if (ssh
->pktin
.maxlen
< st
->cipherblk
) {
942 ssh
->pktin
.maxlen
= st
->cipherblk
;
943 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
, st
->cipherblk
+ APIEXTRA
);
947 * Acquire and decrypt the first block of the packet. This will
948 * contain the length and padding details.
950 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
951 while ((*datalen
) == 0)
952 crReturn(st
->cipherblk
- st
->i
);
953 ssh
->pktin
.data
[st
->i
] = *(*data
)++;
958 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
959 ssh
->pktin
.data
, st
->cipherblk
);
962 * Now get the length and padding figures.
964 st
->len
= GET_32BIT(ssh
->pktin
.data
);
965 st
->pad
= ssh
->pktin
.data
[4];
968 * _Completely_ silly lengths should be stomped on before they
969 * do us any more damage.
971 if (st
->len
< 0 || st
->pad
< 0 || st
->len
+ st
->pad
< 0) {
972 bombout((ssh
,"Incoming packet was garbled on decryption"));
977 * This enables us to deduce the payload length.
979 st
->payload
= st
->len
- st
->pad
- 1;
981 ssh
->pktin
.length
= st
->payload
+ 5;
984 * So now we can work out the total packet length.
986 st
->packetlen
= st
->len
+ 4;
987 st
->maclen
= ssh
->scmac ? ssh
->scmac
->len
: 0;
990 * Adjust memory allocation if packet is too big.
992 if (ssh
->pktin
.maxlen
< st
->packetlen
+ st
->maclen
) {
993 ssh
->pktin
.maxlen
= st
->packetlen
+ st
->maclen
;
994 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
,
995 ssh
->pktin
.maxlen
+ APIEXTRA
);
999 * Read and decrypt the remainder of the packet.
1001 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
;
1003 while ((*datalen
) == 0)
1004 crReturn(st
->packetlen
+ st
->maclen
- st
->i
);
1005 ssh
->pktin
.data
[st
->i
] = *(*data
)++;
1008 /* Decrypt everything _except_ the MAC. */
1010 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
1011 ssh
->pktin
.data
+ st
->cipherblk
,
1012 st
->packetlen
- st
->cipherblk
);
1018 && !ssh
->scmac
->verify(ssh
->sc_mac_ctx
, ssh
->pktin
.data
, st
->len
+ 4,
1019 st
->incoming_sequence
)) {
1020 bombout((ssh
,"Incorrect MAC received on packet"));
1023 st
->incoming_sequence
++; /* whether or not we MACed */
1026 * Decompress packet payload.
1029 unsigned char *newpayload
;
1032 ssh
->sccomp
->decompress(ssh
->sc_comp_ctx
,
1033 ssh
->pktin
.data
+ 5, ssh
->pktin
.length
- 5,
1034 &newpayload
, &newlen
)) {
1035 if (ssh
->pktin
.maxlen
< newlen
+ 5) {
1036 ssh
->pktin
.maxlen
= newlen
+ 5;
1037 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
,
1038 ssh
->pktin
.maxlen
+ APIEXTRA
);
1040 ssh
->pktin
.length
= 5 + newlen
;
1041 memcpy(ssh
->pktin
.data
+ 5, newpayload
, newlen
);
1046 ssh
->pktin
.savedpos
= 6;
1047 ssh
->pktin
.type
= ssh
->pktin
.data
[5];
1050 log_packet(ssh
->logctx
, PKT_INCOMING
, ssh
->pktin
.type
,
1051 ssh2_pkt_type(ssh
->pkt_ctx
, ssh
->pktin
.type
),
1052 ssh
->pktin
.data
+6, ssh
->pktin
.length
-6);
1054 switch (ssh
->pktin
.type
) {
1056 * These packets we must handle instantly.
1058 case SSH2_MSG_DISCONNECT
:
1060 /* log reason code in disconnect message */
1063 int reason
= GET_32BIT(ssh
->pktin
.data
+ 6);
1064 unsigned msglen
= GET_32BIT(ssh
->pktin
.data
+ 10);
1066 if (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) {
1067 buf
= dupprintf("Received disconnect message (%s)",
1068 ssh2_disconnect_reasons
[reason
]);
1070 buf
= dupprintf("Received disconnect message (unknown"
1071 " type %d)", reason
);
1075 buf
= dupprintf("Disconnection message text: %n%.*s",
1076 &nowlen
, msglen
, ssh
->pktin
.data
+ 14);
1078 bombout((ssh
,"Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1080 (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) ?
1081 ssh2_disconnect_reasons
[reason
] : "unknown",
1087 case SSH2_MSG_IGNORE
:
1089 case SSH2_MSG_DEBUG
:
1091 /* log the debug message */
1093 /* int display = ssh->pktin.body[6]; */
1094 int stringlen
= GET_32BIT(ssh
->pktin
.data
+7);
1096 strcpy(buf
, "Remote debug message: ");
1097 prefix
= strlen(buf
);
1098 if (stringlen
> (int)(sizeof(buf
)-prefix
-1))
1099 stringlen
= sizeof(buf
)-prefix
-1;
1100 memcpy(buf
+ prefix
, ssh
->pktin
.data
+ 11, stringlen
);
1101 buf
[prefix
+ stringlen
] = '\0';
1104 goto next_packet
; /* FIXME: print the debug message */
1107 * These packets we need do nothing about here.
1109 case SSH2_MSG_UNIMPLEMENTED
:
1110 case SSH2_MSG_SERVICE_REQUEST
:
1111 case SSH2_MSG_SERVICE_ACCEPT
:
1112 case SSH2_MSG_KEXINIT
:
1113 case SSH2_MSG_NEWKEYS
:
1114 case SSH2_MSG_KEXDH_INIT
:
1115 case SSH2_MSG_KEXDH_REPLY
:
1116 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1117 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1118 case SSH2_MSG_KEX_DH_GEX_INIT
:
1119 case SSH2_MSG_KEX_DH_GEX_REPLY
:
1120 case SSH2_MSG_USERAUTH_REQUEST
:
1121 case SSH2_MSG_USERAUTH_FAILURE
:
1122 case SSH2_MSG_USERAUTH_SUCCESS
:
1123 case SSH2_MSG_USERAUTH_BANNER
:
1124 case SSH2_MSG_USERAUTH_PK_OK
:
1125 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1126 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1127 case SSH2_MSG_USERAUTH_INFO_RESPONSE
:
1128 case SSH2_MSG_GLOBAL_REQUEST
:
1129 case SSH2_MSG_REQUEST_SUCCESS
:
1130 case SSH2_MSG_REQUEST_FAILURE
:
1131 case SSH2_MSG_CHANNEL_OPEN
:
1132 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
:
1133 case SSH2_MSG_CHANNEL_OPEN_FAILURE
:
1134 case SSH2_MSG_CHANNEL_WINDOW_ADJUST
:
1135 case SSH2_MSG_CHANNEL_DATA
:
1136 case SSH2_MSG_CHANNEL_EXTENDED_DATA
:
1137 case SSH2_MSG_CHANNEL_EOF
:
1138 case SSH2_MSG_CHANNEL_CLOSE
:
1139 case SSH2_MSG_CHANNEL_REQUEST
:
1140 case SSH2_MSG_CHANNEL_SUCCESS
:
1141 case SSH2_MSG_CHANNEL_FAILURE
:
1145 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1148 ssh2_pkt_init(ssh
, SSH2_MSG_UNIMPLEMENTED
);
1149 ssh2_pkt_adduint32(ssh
, st
->incoming_sequence
- 1);
1157 static void ssh1_pktout_size(Ssh ssh
, int len
)
1161 len
+= 5; /* type and CRC */
1162 pad
= 8 - (len
% 8);
1165 ssh
->pktout
.length
= len
- 5;
1166 if (ssh
->pktout
.maxlen
< biglen
) {
1167 ssh
->pktout
.maxlen
= biglen
;
1169 /* Allocate enough buffer space for extra block
1170 * for MS CryptEncrypt() */
1171 ssh
->pktout
.data
= srealloc(ssh
->pktout
.data
, biglen
+ 12);
1173 ssh
->pktout
.data
= srealloc(ssh
->pktout
.data
, biglen
+ 4);
1176 ssh
->pktout
.body
= ssh
->pktout
.data
+ 4 + pad
+ 1;
1179 static void s_wrpkt_start(Ssh ssh
, int type
, int len
)
1181 ssh1_pktout_size(ssh
, len
);
1182 ssh
->pktout
.type
= type
;
1185 static int s_wrpkt_prepare(Ssh ssh
)
1187 int pad
, len
, biglen
, i
;
1190 ssh
->pktout
.body
[-1] = ssh
->pktout
.type
;
1193 log_packet(ssh
->logctx
, PKT_OUTGOING
, ssh
->pktout
.type
,
1194 ssh1_pkt_type(ssh
->pktout
.type
),
1195 ssh
->pktout
.body
, ssh
->pktout
.length
);
1197 if (ssh
->v1_compressing
) {
1198 unsigned char *compblk
;
1200 zlib_compress_block(ssh
->cs_comp_ctx
,
1201 ssh
->pktout
.body
- 1, ssh
->pktout
.length
+ 1,
1202 &compblk
, &complen
);
1203 ssh1_pktout_size(ssh
, complen
- 1);
1204 memcpy(ssh
->pktout
.body
- 1, compblk
, complen
);
1208 len
= ssh
->pktout
.length
+ 5; /* type and CRC */
1209 pad
= 8 - (len
% 8);
1212 for (i
= 0; i
< pad
; i
++)
1213 ssh
->pktout
.data
[i
+ 4] = random_byte();
1214 crc
= crc32(ssh
->pktout
.data
+ 4, biglen
- 4);
1215 PUT_32BIT(ssh
->pktout
.data
+ biglen
, crc
);
1216 PUT_32BIT(ssh
->pktout
.data
, len
);
1219 ssh
->cipher
->encrypt(ssh
->v1_cipher_ctx
, ssh
->pktout
.data
+ 4, biglen
);
1224 static void s_wrpkt(Ssh ssh
)
1227 len
= s_wrpkt_prepare(ssh
);
1228 backlog
= sk_write(ssh
->s
, ssh
->pktout
.data
, len
);
1229 if (backlog
> SSH_MAX_BACKLOG
)
1230 ssh_throttle_all(ssh
, 1, backlog
);
1233 static void s_wrpkt_defer(Ssh ssh
)
1236 len
= s_wrpkt_prepare(ssh
);
1237 if (ssh
->deferred_len
+ len
> ssh
->deferred_size
) {
1238 ssh
->deferred_size
= ssh
->deferred_len
+ len
+ 128;
1239 ssh
->deferred_send_data
= srealloc(ssh
->deferred_send_data
,
1240 ssh
->deferred_size
);
1242 memcpy(ssh
->deferred_send_data
+ ssh
->deferred_len
, ssh
->pktout
.data
, len
);
1243 ssh
->deferred_len
+= len
;
1247 * Construct a packet with the specified contents.
1249 static void construct_packet(Ssh ssh
, int pkttype
, va_list ap1
, va_list ap2
)
1251 unsigned char *p
, *argp
, argchar
;
1252 unsigned long argint
;
1253 int pktlen
, argtype
, arglen
;
1257 while ((argtype
= va_arg(ap1
, int)) != PKT_END
) {
1260 (void) va_arg(ap1
, int);
1264 (void) va_arg(ap1
, int);
1268 (void) va_arg(ap1
, unsigned char *);
1269 arglen
= va_arg(ap1
, int);
1273 argp
= va_arg(ap1
, unsigned char *);
1274 arglen
= strlen(argp
);
1275 pktlen
+= 4 + arglen
;
1278 bn
= va_arg(ap1
, Bignum
);
1279 pktlen
+= ssh1_bignum_length(bn
);
1286 s_wrpkt_start(ssh
, pkttype
, pktlen
);
1287 p
= ssh
->pktout
.body
;
1289 while ((argtype
= va_arg(ap2
, int)) != PKT_END
) {
1292 argint
= va_arg(ap2
, int);
1293 PUT_32BIT(p
, argint
);
1297 argchar
= (unsigned char) va_arg(ap2
, int);
1302 argp
= va_arg(ap2
, unsigned char *);
1303 arglen
= va_arg(ap2
, int);
1304 memcpy(p
, argp
, arglen
);
1308 argp
= va_arg(ap2
, unsigned char *);
1309 arglen
= strlen(argp
);
1310 PUT_32BIT(p
, arglen
);
1311 memcpy(p
+ 4, argp
, arglen
);
1315 bn
= va_arg(ap2
, Bignum
);
1316 p
+= ssh1_write_bignum(p
, bn
);
1322 static void send_packet(Ssh ssh
, int pkttype
, ...)
1325 va_start(ap1
, pkttype
);
1326 va_start(ap2
, pkttype
);
1327 construct_packet(ssh
, pkttype
, ap1
, ap2
);
1331 static void defer_packet(Ssh ssh
, int pkttype
, ...)
1334 va_start(ap1
, pkttype
);
1335 va_start(ap2
, pkttype
);
1336 construct_packet(ssh
, pkttype
, ap1
, ap2
);
1340 static int ssh_versioncmp(char *a
, char *b
)
1343 unsigned long av
, bv
;
1345 av
= strtoul(a
, &ae
, 10);
1346 bv
= strtoul(b
, &be
, 10);
1348 return (av
< bv ?
-1 : +1);
1353 av
= strtoul(ae
, &ae
, 10);
1354 bv
= strtoul(be
, &be
, 10);
1356 return (av
< bv ?
-1 : +1);
1361 * Utility routines for putting an SSH-protocol `string' and
1362 * `uint32' into a SHA state.
1365 static void sha_string(SHA_State
* s
, void *str
, int len
)
1367 unsigned char lenblk
[4];
1368 PUT_32BIT(lenblk
, len
);
1369 SHA_Bytes(s
, lenblk
, 4);
1370 SHA_Bytes(s
, str
, len
);
1373 static void sha_uint32(SHA_State
* s
, unsigned i
)
1375 unsigned char intblk
[4];
1376 PUT_32BIT(intblk
, i
);
1377 SHA_Bytes(s
, intblk
, 4);
1381 * SSH2 packet construction functions.
1383 static void ssh2_pkt_ensure(Ssh ssh
, int length
)
1385 if (ssh
->pktout
.maxlen
< length
) {
1386 ssh
->pktout
.maxlen
= length
+ 256;
1387 ssh
->pktout
.data
= srealloc(ssh
->pktout
.data
,
1388 ssh
->pktout
.maxlen
+ APIEXTRA
);
1389 if (!ssh
->pktout
.data
)
1390 fatalbox("Out of memory");
1393 static void ssh2_pkt_adddata(Ssh ssh
, void *data
, int len
)
1395 ssh
->pktout
.length
+= len
;
1396 ssh2_pkt_ensure(ssh
, ssh
->pktout
.length
);
1397 memcpy(ssh
->pktout
.data
+ ssh
->pktout
.length
- len
, data
, len
);
1399 static void ssh2_pkt_addbyte(Ssh ssh
, unsigned char byte
)
1401 ssh2_pkt_adddata(ssh
, &byte
, 1);
1403 static void ssh2_pkt_init(Ssh ssh
, int pkt_type
)
1405 ssh
->pktout
.length
= 5;
1406 ssh2_pkt_addbyte(ssh
, (unsigned char) pkt_type
);
1408 static void ssh2_pkt_addbool(Ssh ssh
, unsigned char value
)
1410 ssh2_pkt_adddata(ssh
, &value
, 1);
1412 static void ssh2_pkt_adduint32(Ssh ssh
, unsigned long value
)
1415 PUT_32BIT(x
, value
);
1416 ssh2_pkt_adddata(ssh
, x
, 4);
1418 static void ssh2_pkt_addstring_start(Ssh ssh
)
1420 ssh2_pkt_adduint32(ssh
, 0);
1421 ssh
->pktout
.savedpos
= ssh
->pktout
.length
;
1423 static void ssh2_pkt_addstring_str(Ssh ssh
, char *data
)
1425 ssh2_pkt_adddata(ssh
, data
, strlen(data
));
1426 PUT_32BIT(ssh
->pktout
.data
+ ssh
->pktout
.savedpos
- 4,
1427 ssh
->pktout
.length
- ssh
->pktout
.savedpos
);
1429 static void ssh2_pkt_addstring_data(Ssh ssh
, char *data
, int len
)
1431 ssh2_pkt_adddata(ssh
, data
, len
);
1432 PUT_32BIT(ssh
->pktout
.data
+ ssh
->pktout
.savedpos
- 4,
1433 ssh
->pktout
.length
- ssh
->pktout
.savedpos
);
1435 static void ssh2_pkt_addstring(Ssh ssh
, char *data
)
1437 ssh2_pkt_addstring_start(ssh
);
1438 ssh2_pkt_addstring_str(ssh
, data
);
1440 static char *ssh2_mpint_fmt(Bignum b
, int *len
)
1443 int i
, n
= (bignum_bitcount(b
) + 7) / 8;
1446 fatalbox("out of memory");
1448 for (i
= 1; i
<= n
; i
++)
1449 p
[i
] = bignum_byte(b
, n
- i
);
1451 while (i
<= n
&& p
[i
] == 0 && (p
[i
+ 1] & 0x80) == 0)
1453 memmove(p
, p
+ i
, n
+ 1 - i
);
1457 static void ssh2_pkt_addmp(Ssh ssh
, Bignum b
)
1461 p
= ssh2_mpint_fmt(b
, &len
);
1462 ssh2_pkt_addstring_start(ssh
);
1463 ssh2_pkt_addstring_data(ssh
, p
, len
);
1468 * Construct an SSH2 final-form packet: compress it, encrypt it,
1469 * put the MAC on it. Final packet, ready to be sent, is stored in
1470 * ssh->pktout.data. Total length is returned.
1472 static int ssh2_pkt_construct(Ssh ssh
)
1474 int cipherblk
, maclen
, padding
, i
;
1477 log_packet(ssh
->logctx
, PKT_OUTGOING
, ssh
->pktout
.data
[5],
1478 ssh2_pkt_type(ssh
->pkt_ctx
, ssh
->pktout
.data
[5]),
1479 ssh
->pktout
.data
+ 6, ssh
->pktout
.length
- 6);
1482 * Compress packet payload.
1485 unsigned char *newpayload
;
1488 ssh
->cscomp
->compress(ssh
->cs_comp_ctx
, ssh
->pktout
.data
+ 5,
1489 ssh
->pktout
.length
- 5,
1490 &newpayload
, &newlen
)) {
1491 ssh
->pktout
.length
= 5;
1492 ssh2_pkt_adddata(ssh
, newpayload
, newlen
);
1498 * Add padding. At least four bytes, and must also bring total
1499 * length (minus MAC) up to a multiple of the block size.
1501 cipherblk
= ssh
->cscipher ? ssh
->cscipher
->blksize
: 8; /* block size */
1502 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
1505 (cipherblk
- (ssh
->pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
1506 maclen
= ssh
->csmac ? ssh
->csmac
->len
: 0;
1507 ssh2_pkt_ensure(ssh
, ssh
->pktout
.length
+ padding
+ maclen
);
1508 ssh
->pktout
.data
[4] = padding
;
1509 for (i
= 0; i
< padding
; i
++)
1510 ssh
->pktout
.data
[ssh
->pktout
.length
+ i
] = random_byte();
1511 PUT_32BIT(ssh
->pktout
.data
, ssh
->pktout
.length
+ padding
- 4);
1513 ssh
->csmac
->generate(ssh
->cs_mac_ctx
, ssh
->pktout
.data
,
1514 ssh
->pktout
.length
+ padding
,
1515 ssh
->v2_outgoing_sequence
);
1516 ssh
->v2_outgoing_sequence
++; /* whether or not we MACed */
1519 ssh
->cscipher
->encrypt(ssh
->cs_cipher_ctx
,
1520 ssh
->pktout
.data
, ssh
->pktout
.length
+ padding
);
1522 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1523 return ssh
->pktout
.length
+ padding
+ maclen
;
1527 * Construct and send an SSH2 packet immediately.
1529 static void ssh2_pkt_send(Ssh ssh
)
1533 len
= ssh2_pkt_construct(ssh
);
1534 backlog
= sk_write(ssh
->s
, ssh
->pktout
.data
, len
);
1535 if (backlog
> SSH_MAX_BACKLOG
)
1536 ssh_throttle_all(ssh
, 1, backlog
);
1540 * Construct an SSH2 packet and add it to a deferred data block.
1541 * Useful for sending multiple packets in a single sk_write() call,
1542 * to prevent a traffic-analysing listener from being able to work
1543 * out the length of any particular packet (such as the password
1546 * Note that because SSH2 sequence-numbers its packets, this can
1547 * NOT be used as an m4-style `defer' allowing packets to be
1548 * constructed in one order and sent in another.
1550 static void ssh2_pkt_defer(Ssh ssh
)
1552 int len
= ssh2_pkt_construct(ssh
);
1553 if (ssh
->deferred_len
+ len
> ssh
->deferred_size
) {
1554 ssh
->deferred_size
= ssh
->deferred_len
+ len
+ 128;
1555 ssh
->deferred_send_data
= srealloc(ssh
->deferred_send_data
,
1556 ssh
->deferred_size
);
1558 memcpy(ssh
->deferred_send_data
+ ssh
->deferred_len
, ssh
->pktout
.data
, len
);
1559 ssh
->deferred_len
+= len
;
1563 * Send the whole deferred data block constructed by
1564 * ssh2_pkt_defer() or SSH1's defer_packet().
1566 static void ssh_pkt_defersend(Ssh ssh
)
1569 backlog
= sk_write(ssh
->s
, ssh
->deferred_send_data
, ssh
->deferred_len
);
1570 ssh
->deferred_len
= ssh
->deferred_size
= 0;
1571 sfree(ssh
->deferred_send_data
);
1572 ssh
->deferred_send_data
= NULL
;
1573 if (backlog
> SSH_MAX_BACKLOG
)
1574 ssh_throttle_all(ssh
, 1, backlog
);
1578 void bndebug(char *string
, Bignum b
)
1582 p
= ssh2_mpint_fmt(b
, &len
);
1583 debug(("%s", string
));
1584 for (i
= 0; i
< len
; i
++)
1585 debug((" %02x", p
[i
]));
1591 static void sha_mpint(SHA_State
* s
, Bignum b
)
1595 p
= ssh2_mpint_fmt(b
, &len
);
1596 sha_string(s
, p
, len
);
1601 * SSH2 packet decode functions.
1603 static unsigned long ssh2_pkt_getuint32(Ssh ssh
)
1605 unsigned long value
;
1606 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< 4)
1607 return 0; /* arrgh, no way to decline (FIXME?) */
1608 value
= GET_32BIT(ssh
->pktin
.data
+ ssh
->pktin
.savedpos
);
1609 ssh
->pktin
.savedpos
+= 4;
1612 static int ssh2_pkt_getbool(Ssh ssh
)
1614 unsigned long value
;
1615 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< 1)
1616 return 0; /* arrgh, no way to decline (FIXME?) */
1617 value
= ssh
->pktin
.data
[ssh
->pktin
.savedpos
] != 0;
1618 ssh
->pktin
.savedpos
++;
1621 static void ssh2_pkt_getstring(Ssh ssh
, char **p
, int *length
)
1626 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< 4)
1628 len
= GET_32BIT(ssh
->pktin
.data
+ ssh
->pktin
.savedpos
);
1632 ssh
->pktin
.savedpos
+= 4;
1633 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< *length
)
1635 *p
= ssh
->pktin
.data
+ ssh
->pktin
.savedpos
;
1636 ssh
->pktin
.savedpos
+= *length
;
1638 static Bignum
ssh2_pkt_getmp(Ssh ssh
)
1644 ssh2_pkt_getstring(ssh
, &p
, &length
);
1648 bombout((ssh
,"internal error: Can't handle negative mpints"));
1651 b
= bignum_from_bytes(p
, length
);
1656 * Helper function to add an SSH2 signature blob to a packet.
1657 * Expects to be shown the public key blob as well as the signature
1658 * blob. Normally works just like ssh2_pkt_addstring, but will
1659 * fiddle with the signature packet if necessary for
1660 * BUG_SSH2_RSA_PADDING.
1662 static void ssh2_add_sigblob(Ssh ssh
, void *pkblob_v
, int pkblob_len
,
1663 void *sigblob_v
, int sigblob_len
)
1665 unsigned char *pkblob
= (unsigned char *)pkblob_v
;
1666 unsigned char *sigblob
= (unsigned char *)sigblob_v
;
1668 /* dmemdump(pkblob, pkblob_len); */
1669 /* dmemdump(sigblob, sigblob_len); */
1672 * See if this is in fact an ssh-rsa signature and a buggy
1673 * server; otherwise we can just do this the easy way.
1675 if ((ssh
->remote_bugs
& BUG_SSH2_RSA_PADDING
) &&
1676 (GET_32BIT(pkblob
) == 7 && !memcmp(pkblob
+4, "ssh-rsa", 7))) {
1677 int pos
, len
, siglen
;
1680 * Find the byte length of the modulus.
1683 pos
= 4+7; /* skip over "ssh-rsa" */
1684 pos
+= 4 + GET_32BIT(pkblob
+pos
); /* skip over exponent */
1685 len
= GET_32BIT(pkblob
+pos
); /* find length of modulus */
1686 pos
+= 4; /* find modulus itself */
1687 while (len
> 0 && pkblob
[pos
] == 0)
1689 /* debug(("modulus length is %d\n", len)); */
1692 * Now find the signature integer.
1694 pos
= 4+7; /* skip over "ssh-rsa" */
1695 siglen
= GET_32BIT(sigblob
+pos
);
1696 /* debug(("signature length is %d\n", siglen)); */
1698 if (len
!= siglen
) {
1699 unsigned char newlen
[4];
1700 ssh2_pkt_addstring_start(ssh
);
1701 ssh2_pkt_addstring_data(ssh
, sigblob
, pos
);
1702 /* dmemdump(sigblob, pos); */
1703 pos
+= 4; /* point to start of actual sig */
1704 PUT_32BIT(newlen
, len
);
1705 ssh2_pkt_addstring_data(ssh
, newlen
, 4);
1706 /* dmemdump(newlen, 4); */
1708 while (len
-- > siglen
) {
1709 ssh2_pkt_addstring_data(ssh
, newlen
, 1);
1710 /* dmemdump(newlen, 1); */
1712 ssh2_pkt_addstring_data(ssh
, sigblob
+pos
, siglen
);
1713 /* dmemdump(sigblob+pos, siglen); */
1717 /* Otherwise fall through and do it the easy way. */
1720 ssh2_pkt_addstring_start(ssh
);
1721 ssh2_pkt_addstring_data(ssh
, sigblob
, sigblob_len
);
1725 * Examine the remote side's version string and compare it against
1726 * a list of known buggy implementations.
1728 static void ssh_detect_bugs(Ssh ssh
, char *vstring
)
1730 char *imp
; /* pointer to implementation part */
1732 imp
+= strcspn(imp
, "-");
1734 imp
+= strcspn(imp
, "-");
1737 ssh
->remote_bugs
= 0;
1739 if (cfg
.sshbug_ignore1
== BUG_ON
||
1740 (cfg
.sshbug_ignore1
== BUG_AUTO
&&
1741 (!strcmp(imp
, "1.2.18") || !strcmp(imp
, "1.2.19") ||
1742 !strcmp(imp
, "1.2.20") || !strcmp(imp
, "1.2.21") ||
1743 !strcmp(imp
, "1.2.22") || !strcmp(imp
, "Cisco-1.25")))) {
1745 * These versions don't support SSH1_MSG_IGNORE, so we have
1746 * to use a different defence against password length
1749 ssh
->remote_bugs
|= BUG_CHOKES_ON_SSH1_IGNORE
;
1750 logevent("We believe remote version has SSH1 ignore bug");
1753 if (cfg
.sshbug_plainpw1
== BUG_ON
||
1754 (cfg
.sshbug_plainpw1
== BUG_AUTO
&&
1755 (!strcmp(imp
, "Cisco-1.25")))) {
1757 * These versions need a plain password sent; they can't
1758 * handle having a null and a random length of data after
1761 ssh
->remote_bugs
|= BUG_NEEDS_SSH1_PLAIN_PASSWORD
;
1762 logevent("We believe remote version needs a plain SSH1 password");
1765 if (cfg
.sshbug_rsa1
== BUG_ON
||
1766 (cfg
.sshbug_rsa1
== BUG_AUTO
&&
1767 (!strcmp(imp
, "Cisco-1.25")))) {
1769 * These versions apparently have no clue whatever about
1770 * RSA authentication and will panic and die if they see
1771 * an AUTH_RSA message.
1773 ssh
->remote_bugs
|= BUG_CHOKES_ON_RSA
;
1774 logevent("We believe remote version can't handle RSA authentication");
1777 if (cfg
.sshbug_hmac2
== BUG_ON
||
1778 (cfg
.sshbug_hmac2
== BUG_AUTO
&&
1779 (wc_match("2.1.0*", imp
) || wc_match("2.0.*", imp
) ||
1780 wc_match("2.2.0*", imp
) || wc_match("2.3.0*", imp
) ||
1781 wc_match("2.1 *", imp
)))) {
1783 * These versions have the HMAC bug.
1785 ssh
->remote_bugs
|= BUG_SSH2_HMAC
;
1786 logevent("We believe remote version has SSH2 HMAC bug");
1789 if (cfg
.sshbug_derivekey2
== BUG_ON
||
1790 (cfg
.sshbug_derivekey2
== BUG_AUTO
&&
1791 (wc_match("2.0.0*", imp
) || wc_match("2.0.1[01]*", imp
) ))) {
1793 * These versions have the key-derivation bug (failing to
1794 * include the literal shared secret in the hashes that
1795 * generate the keys).
1797 ssh
->remote_bugs
|= BUG_SSH2_DERIVEKEY
;
1798 logevent("We believe remote version has SSH2 key-derivation bug");
1801 if (cfg
.sshbug_rsapad2
== BUG_ON
||
1802 (cfg
.sshbug_rsapad2
== BUG_AUTO
&&
1803 (wc_match("OpenSSH_2.[5-9]*", imp
) ||
1804 wc_match("OpenSSH_3.[0-2]*", imp
)))) {
1806 * These versions have the SSH2 RSA padding bug.
1808 ssh
->remote_bugs
|= BUG_SSH2_RSA_PADDING
;
1809 logevent("We believe remote version has SSH2 RSA padding bug");
1812 if (cfg
.sshbug_dhgex2
== BUG_ON
) {
1814 * User specified the SSH2 DH GEX bug.
1816 ssh
->remote_bugs
|= BUG_SSH2_DH_GEX
;
1817 logevent("We believe remote version has SSH2 DH group exchange bug");
1821 static int do_ssh_init(Ssh ssh
, unsigned char c
)
1823 struct do_ssh_init_state
{
1831 crState(do_ssh_init_state
);
1833 crBegin(ssh
->do_ssh_init_crstate
);
1835 /* Search for the string "SSH-" in the input. */
1838 static const int transS
[] = { 1, 2, 2, 1 };
1839 static const int transH
[] = { 0, 0, 3, 0 };
1840 static const int transminus
[] = { 0, 0, 0, -1 };
1842 s
->i
= transS
[s
->i
];
1844 s
->i
= transH
[s
->i
];
1846 s
->i
= transminus
[s
->i
];
1851 crReturn(1); /* get another character */
1855 s
->vstring
= smalloc(s
->vstrsize
);
1856 strcpy(s
->vstring
, "SSH-");
1860 crReturn(1); /* get another char */
1861 if (s
->vslen
>= s
->vstrsize
- 1) {
1863 s
->vstring
= srealloc(s
->vstring
, s
->vstrsize
);
1865 s
->vstring
[s
->vslen
++] = c
;
1868 s
->version
[s
->i
] = '\0';
1870 } else if (s
->i
< sizeof(s
->version
) - 1)
1871 s
->version
[s
->i
++] = c
;
1872 } else if (c
== '\n')
1876 ssh
->agentfwd_enabled
= FALSE
;
1877 ssh
->rdpkt2_state
.incoming_sequence
= 0;
1879 s
->vstring
[s
->vslen
] = 0;
1880 s
->vstring
[strcspn(s
->vstring
, "\r\n")] = '\0';/* remove EOL chars */
1883 vlog
= smalloc(20 + s
->vslen
);
1884 sprintf(vlog
, "Server version: %s", s
->vstring
);
1888 ssh_detect_bugs(ssh
, s
->vstring
);
1891 * Decide which SSH protocol version to support.
1894 /* Anything strictly below "2.0" means protocol 1 is supported. */
1895 s
->proto1
= ssh_versioncmp(s
->version
, "2.0") < 0;
1896 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
1897 s
->proto2
= ssh_versioncmp(s
->version
, "1.99") >= 0;
1899 if (cfg
.sshprot
== 0 && !s
->proto1
) {
1900 bombout((ssh
,"SSH protocol version 1 required by user but not provided by server"));
1903 if (cfg
.sshprot
== 3 && !s
->proto2
) {
1904 bombout((ssh
,"SSH protocol version 2 required by user but not provided by server"));
1908 if (s
->proto2
&& (cfg
.sshprot
>= 2 || !s
->proto1
)) {
1912 char verstring
[80], vlog
[100];
1913 sprintf(verstring
, "SSH-2.0-%s", sshver
);
1914 SHA_Init(&ssh
->exhashbase
);
1916 * Hash our version string and their version string.
1918 sha_string(&ssh
->exhashbase
, verstring
, strlen(verstring
));
1919 sha_string(&ssh
->exhashbase
, s
->vstring
, strcspn(s
->vstring
, "\r\n"));
1920 sprintf(vlog
, "We claim version: %s", verstring
);
1922 strcat(verstring
, "\n");
1923 logevent("Using SSH protocol version 2");
1924 sk_write(ssh
->s
, verstring
, strlen(verstring
));
1925 ssh
->protocol
= ssh2_protocol
;
1927 ssh
->s_rdpkt
= ssh2_rdpkt
;
1932 char verstring
[80], vlog
[100];
1933 sprintf(verstring
, "SSH-%s-%s",
1934 (ssh_versioncmp(s
->version
, "1.5") <= 0 ? s
->version
: "1.5"),
1936 sprintf(vlog
, "We claim version: %s", verstring
);
1938 strcat(verstring
, "\n");
1940 logevent("Using SSH protocol version 1");
1941 sk_write(ssh
->s
, verstring
, strlen(verstring
));
1942 ssh
->protocol
= ssh1_protocol
;
1944 ssh
->s_rdpkt
= ssh1_rdpkt
;
1946 ssh
->state
= SSH_STATE_BEFORE_SIZE
;
1953 static void ssh_gotdata(Ssh ssh
, unsigned char *data
, int datalen
)
1955 crBegin(ssh
->ssh_gotdata_crstate
);
1958 * To begin with, feed the characters one by one to the
1959 * protocol initialisation / selection function do_ssh_init().
1960 * When that returns 0, we're done with the initial greeting
1961 * exchange and can move on to packet discipline.
1964 int ret
; /* need not be kept across crReturn */
1966 crReturnV
; /* more data please */
1967 ret
= do_ssh_init(ssh
, *data
);
1975 * We emerge from that loop when the initial negotiation is
1976 * over and we have selected an s_rdpkt function. Now pass
1977 * everything to s_rdpkt, and then pass the resulting packets
1978 * to the proper protocol handler.
1983 while (datalen
> 0) {
1984 if (ssh
->s_rdpkt(ssh
, &data
, &datalen
) == 0) {
1985 if (ssh
->state
== SSH_STATE_CLOSED
) {
1988 ssh
->protocol(ssh
, NULL
, 0, 1);
1989 if (ssh
->state
== SSH_STATE_CLOSED
) {
1999 static int ssh_closing(Plug plug
, char *error_msg
, int error_code
,
2002 Ssh ssh
= (Ssh
) plug
;
2003 ssh
->state
= SSH_STATE_CLOSED
;
2009 /* A socket error has occurred. */
2010 logevent(error_msg
);
2011 connection_fatal(ssh
->frontend
, error_msg
);
2013 /* Otherwise, the remote side closed the connection normally. */
2018 static int ssh_receive(Plug plug
, int urgent
, char *data
, int len
)
2020 Ssh ssh
= (Ssh
) plug
;
2021 ssh_gotdata(ssh
, data
, len
);
2022 if (ssh
->state
== SSH_STATE_CLOSED
) {
2032 static void ssh_sent(Plug plug
, int bufsize
)
2034 Ssh ssh
= (Ssh
) plug
;
2036 * If the send backlog on the SSH socket itself clears, we
2037 * should unthrottle the whole world if it was throttled.
2039 if (bufsize
< SSH_MAX_BACKLOG
)
2040 ssh_throttle_all(ssh
, 0, bufsize
);
2044 * Connect to specified host and port.
2045 * Returns an error message, or NULL on success.
2046 * Also places the canonical host name into `realhost'. It must be
2047 * freed by the caller.
2049 static char *connect_to_host(Ssh ssh
, char *host
, int port
,
2050 char **realhost
, int nodelay
)
2052 static const struct plug_function_table fn_table
= {
2062 ssh
->savedhost
= smalloc(1 + strlen(host
));
2063 if (!ssh
->savedhost
)
2064 fatalbox("Out of memory");
2065 strcpy(ssh
->savedhost
, host
);
2068 port
= 22; /* default ssh port */
2069 ssh
->savedport
= port
;
2074 logeventf(ssh
, "Looking up host \"%s\"", host
);
2075 addr
= sk_namelookup(host
, realhost
);
2076 if ((err
= sk_addr_error(addr
)))
2084 sk_getaddr(addr
, addrbuf
, 100);
2085 logeventf(ssh
, "Connecting to %s port %d", addrbuf
, port
);
2087 ssh
->fn
= &fn_table
;
2088 ssh
->s
= new_connection(addr
, *realhost
, port
, 0, 1, nodelay
, (Plug
) ssh
);
2089 if ((err
= sk_socket_error(ssh
->s
))) {
2098 * Throttle or unthrottle the SSH connection.
2100 static void ssh1_throttle(Ssh ssh
, int adjust
)
2102 int old_count
= ssh
->v1_throttle_count
;
2103 ssh
->v1_throttle_count
+= adjust
;
2104 assert(ssh
->v1_throttle_count
>= 0);
2105 if (ssh
->v1_throttle_count
&& !old_count
) {
2106 sk_set_frozen(ssh
->s
, 1);
2107 } else if (!ssh
->v1_throttle_count
&& old_count
) {
2108 sk_set_frozen(ssh
->s
, 0);
2113 * Throttle or unthrottle _all_ local data streams (for when sends
2114 * on the SSH connection itself back up).
2116 static void ssh_throttle_all(Ssh ssh
, int enable
, int bufsize
)
2119 struct ssh_channel
*c
;
2121 if (enable
== ssh
->throttled_all
)
2123 ssh
->throttled_all
= enable
;
2124 ssh
->overall_bufsize
= bufsize
;
2127 for (i
= 0; NULL
!= (c
= index234(ssh
->channels
, i
)); i
++) {
2129 case CHAN_MAINSESSION
:
2131 * This is treated separately, outside the switch.
2135 x11_override_throttle(c
->u
.x11
.s
, enable
);
2138 /* Agent channels require no buffer management. */
2141 pfd_override_throttle(c
->u
.x11
.s
, enable
);
2148 * Username and password input, abstracted off into routines
2149 * reusable in several places - even between SSH1 and SSH2.
2152 /* Set up a username or password input loop on a given buffer. */
2153 void setup_userpass_input(Ssh ssh
, char *buffer
, int buflen
, int echo
)
2155 ssh
->userpass_input_buffer
= buffer
;
2156 ssh
->userpass_input_buflen
= buflen
;
2157 ssh
->userpass_input_bufpos
= 0;
2158 ssh
->userpass_input_echo
= echo
;
2162 * Process some terminal data in the course of username/password
2163 * input. Returns >0 for success (line of input returned in
2164 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2165 * for inconclusive (keep waiting for more input please).
2167 int process_userpass_input(Ssh ssh
, unsigned char *in
, int inlen
)
2172 switch (c
= *in
++) {
2175 ssh
->userpass_input_buffer
[ssh
->userpass_input_bufpos
] = 0;
2176 ssh
->userpass_input_buffer
[ssh
->userpass_input_buflen
-1] = 0;
2181 if (ssh
->userpass_input_bufpos
> 0) {
2182 if (ssh
->userpass_input_echo
)
2183 c_write_str(ssh
, "\b \b");
2184 ssh
->userpass_input_bufpos
--;
2189 while (ssh
->userpass_input_bufpos
> 0) {
2190 if (ssh
->userpass_input_echo
)
2191 c_write_str(ssh
, "\b \b");
2192 ssh
->userpass_input_bufpos
--;
2200 if (((c
>= ' ' && c
<= '~') ||
2201 ((unsigned char) c
>= 160))
2202 && ssh
->userpass_input_bufpos
< ssh
->userpass_input_buflen
-1) {
2203 ssh
->userpass_input_buffer
[ssh
->userpass_input_bufpos
++] = c
;
2204 if (ssh
->userpass_input_echo
)
2205 c_write(ssh
, &c
, 1);
2214 * Handle the key exchange and user authentication phases.
2216 static int do_ssh1_login(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
2219 unsigned char cookie
[8];
2220 struct RSAKey servkey
, hostkey
;
2221 struct MD5Context md5c
;
2222 struct do_ssh1_login_state
{
2224 unsigned char *rsabuf
, *keystr1
, *keystr2
;
2225 unsigned long supported_ciphers_mask
, supported_auths_mask
;
2226 int tried_publickey
, tried_agent
;
2227 int tis_auth_refused
, ccard_auth_refused
;
2228 unsigned char session_id
[16];
2231 void *publickey_blob
;
2232 int publickey_bloblen
;
2238 unsigned char request
[5], *response
, *p
;
2247 crState(do_ssh1_login_state
);
2249 crBegin(ssh
->do_ssh1_login_crstate
);
2254 if (ssh
->pktin
.type
!= SSH1_SMSG_PUBLIC_KEY
) {
2255 bombout((ssh
,"Public key packet not received"));
2259 logevent("Received public keys");
2261 memcpy(cookie
, ssh
->pktin
.body
, 8);
2263 i
= makekey(ssh
->pktin
.body
+ 8, &servkey
, &s
->keystr1
, 0);
2264 j
= makekey(ssh
->pktin
.body
+ 8 + i
, &hostkey
, &s
->keystr2
, 0);
2267 * Log the host key fingerprint.
2271 logevent("Host key fingerprint is:");
2272 strcpy(logmsg
, " ");
2273 hostkey
.comment
= NULL
;
2274 rsa_fingerprint(logmsg
+ strlen(logmsg
),
2275 sizeof(logmsg
) - strlen(logmsg
), &hostkey
);
2279 ssh
->v1_remote_protoflags
= GET_32BIT(ssh
->pktin
.body
+ 8 + i
+ j
);
2280 s
->supported_ciphers_mask
= GET_32BIT(ssh
->pktin
.body
+ 12 + i
+ j
);
2281 s
->supported_auths_mask
= GET_32BIT(ssh
->pktin
.body
+ 16 + i
+ j
);
2283 ssh
->v1_local_protoflags
=
2284 ssh
->v1_remote_protoflags
& SSH1_PROTOFLAGS_SUPPORTED
;
2285 ssh
->v1_local_protoflags
|= SSH1_PROTOFLAG_SCREEN_NUMBER
;
2288 MD5Update(&md5c
, s
->keystr2
, hostkey
.bytes
);
2289 MD5Update(&md5c
, s
->keystr1
, servkey
.bytes
);
2290 MD5Update(&md5c
, ssh
->pktin
.body
, 8);
2291 MD5Final(s
->session_id
, &md5c
);
2293 for (i
= 0; i
< 32; i
++)
2294 ssh
->session_key
[i
] = random_byte();
2296 s
->len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
2298 s
->rsabuf
= smalloc(s
->len
);
2300 fatalbox("Out of memory");
2303 * Verify the host key.
2307 * First format the key into a string.
2309 int len
= rsastr_len(&hostkey
);
2310 char fingerprint
[100];
2311 char *keystr
= smalloc(len
);
2313 fatalbox("Out of memory");
2314 rsastr_fmt(keystr
, &hostkey
);
2315 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
2316 verify_ssh_host_key(ssh
->frontend
,
2317 ssh
->savedhost
, ssh
->savedport
, "rsa", keystr
,
2322 for (i
= 0; i
< 32; i
++) {
2323 s
->rsabuf
[i
] = ssh
->session_key
[i
];
2325 s
->rsabuf
[i
] ^= s
->session_id
[i
];
2328 if (hostkey
.bytes
> servkey
.bytes
) {
2329 rsaencrypt(s
->rsabuf
, 32, &servkey
);
2330 rsaencrypt(s
->rsabuf
, servkey
.bytes
, &hostkey
);
2332 rsaencrypt(s
->rsabuf
, 32, &hostkey
);
2333 rsaencrypt(s
->rsabuf
, hostkey
.bytes
, &servkey
);
2336 logevent("Encrypted session key");
2339 int cipher_chosen
= 0, warn
= 0;
2340 char *cipher_string
= NULL
;
2342 for (i
= 0; !cipher_chosen
&& i
< CIPHER_MAX
; i
++) {
2343 int next_cipher
= cfg
.ssh_cipherlist
[i
];
2344 if (next_cipher
== CIPHER_WARN
) {
2345 /* If/when we choose a cipher, warn about it */
2347 } else if (next_cipher
== CIPHER_AES
) {
2348 /* XXX Probably don't need to mention this. */
2349 logevent("AES not supported in SSH1, skipping");
2351 switch (next_cipher
) {
2352 case CIPHER_3DES
: s
->cipher_type
= SSH_CIPHER_3DES
;
2353 cipher_string
= "3DES"; break;
2354 case CIPHER_BLOWFISH
: s
->cipher_type
= SSH_CIPHER_BLOWFISH
;
2355 cipher_string
= "Blowfish"; break;
2356 case CIPHER_DES
: s
->cipher_type
= SSH_CIPHER_DES
;
2357 cipher_string
= "single-DES"; break;
2359 if (s
->supported_ciphers_mask
& (1 << s
->cipher_type
))
2363 if (!cipher_chosen
) {
2364 if ((s
->supported_ciphers_mask
& (1 << SSH_CIPHER_3DES
)) == 0)
2365 bombout((ssh
,"Server violates SSH 1 protocol by not "
2366 "supporting 3DES encryption"));
2368 /* shouldn't happen */
2369 bombout((ssh
,"No supported ciphers found"));
2373 /* Warn about chosen cipher if necessary. */
2375 askcipher(ssh
->frontend
, cipher_string
, 0);
2378 switch (s
->cipher_type
) {
2379 case SSH_CIPHER_3DES
:
2380 logevent("Using 3DES encryption");
2382 case SSH_CIPHER_DES
:
2383 logevent("Using single-DES encryption");
2385 case SSH_CIPHER_BLOWFISH
:
2386 logevent("Using Blowfish encryption");
2390 send_packet(ssh
, SSH1_CMSG_SESSION_KEY
,
2391 PKT_CHAR
, s
->cipher_type
,
2392 PKT_DATA
, cookie
, 8,
2393 PKT_CHAR
, (s
->len
* 8) >> 8, PKT_CHAR
, (s
->len
* 8) & 0xFF,
2394 PKT_DATA
, s
->rsabuf
, s
->len
,
2395 PKT_INT
, ssh
->v1_local_protoflags
, PKT_END
);
2397 logevent("Trying to enable encryption...");
2401 ssh
->cipher
= (s
->cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
2402 s
->cipher_type
== SSH_CIPHER_DES ?
&ssh_des
:
2404 ssh
->v1_cipher_ctx
= ssh
->cipher
->make_context();
2405 ssh
->cipher
->sesskey(ssh
->v1_cipher_ctx
, ssh
->session_key
);
2406 logeventf(ssh
, "Initialised %s encryption", ssh
->cipher
->text_name
);
2408 ssh
->crcda_ctx
= crcda_make_context();
2409 logevent("Installing CRC compensation attack detector");
2413 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2414 bombout((ssh
,"Encryption not successfully enabled"));
2418 logevent("Successfully started encryption");
2422 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
2423 if (ssh_get_line
&& !ssh_getline_pw_only
) {
2424 if (!ssh_get_line("login as: ",
2425 s
->username
, sizeof(s
->username
), FALSE
)) {
2427 * get_line failed to get a username.
2430 logevent("No username provided. Abandoning session.");
2431 ssh
->state
= SSH_STATE_CLOSED
;
2435 int ret
; /* need not be kept over crReturn */
2436 c_write_str(ssh
, "login as: ");
2439 setup_userpass_input(ssh
, s
->username
, sizeof(s
->username
), 1);
2441 crWaitUntil(!ispkt
);
2442 ret
= process_userpass_input(ssh
, in
, inlen
);
2446 c_write_str(ssh
, "\r\n");
2449 strncpy(s
->username
, cfg
.username
, sizeof(s
->username
));
2450 s
->username
[sizeof(s
->username
)-1] = '\0';
2453 send_packet(ssh
, SSH1_CMSG_USER
, PKT_STR
, s
->username
, PKT_END
);
2455 char userlog
[22 + sizeof(s
->username
)];
2456 sprintf(userlog
, "Sent username \"%s\"", s
->username
);
2458 if (flags
& FLAG_INTERACTIVE
&&
2459 (!((flags
& FLAG_STDERR
) && (flags
& FLAG_VERBOSE
)))) {
2460 strcat(userlog
, "\r\n");
2461 c_write_str(ssh
, userlog
);
2468 if ((ssh
->remote_bugs
& BUG_CHOKES_ON_RSA
)) {
2469 /* We must not attempt PK auth. Pretend we've already tried it. */
2470 s
->tried_publickey
= s
->tried_agent
= 1;
2472 s
->tried_publickey
= s
->tried_agent
= 0;
2474 s
->tis_auth_refused
= s
->ccard_auth_refused
= 0;
2475 /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
2477 if (!rsakey_pubblob(cfg
.keyfile
,
2478 &s
->publickey_blob
, &s
->publickey_bloblen
))
2479 s
->publickey_blob
= NULL
;
2481 s
->publickey_blob
= NULL
;
2483 while (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2484 s
->pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
2486 if (agent_exists() && !s
->tried_agent
) {
2488 * Attempt RSA authentication using Pageant.
2494 logevent("Pageant is running. Requesting keys.");
2496 /* Request the keys held by the agent. */
2497 PUT_32BIT(s
->request
, 1);
2498 s
->request
[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES
;
2499 agent_query(s
->request
, 5, &r
, &s
->responselen
);
2500 s
->response
= (unsigned char *) r
;
2501 if (s
->response
&& s
->responselen
>= 5 &&
2502 s
->response
[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER
) {
2503 s
->p
= s
->response
+ 5;
2504 s
->nkeys
= GET_32BIT(s
->p
);
2508 sprintf(buf
, "Pageant has %d SSH1 keys", s
->nkeys
);
2511 for (s
->keyi
= 0; s
->keyi
< s
->nkeys
; s
->keyi
++) {
2514 sprintf(buf
, "Trying Pageant key #%d", s
->keyi
);
2517 if (s
->publickey_blob
&&
2518 !memcmp(s
->p
, s
->publickey_blob
,
2519 s
->publickey_bloblen
)) {
2520 logevent("This key matches configured key file");
2521 s
->tried_publickey
= 1;
2524 s
->p
+= ssh1_read_bignum(s
->p
, &s
->key
.exponent
);
2525 s
->p
+= ssh1_read_bignum(s
->p
, &s
->key
.modulus
);
2526 s
->commentlen
= GET_32BIT(s
->p
);
2529 s
->p
+= s
->commentlen
;
2530 send_packet(ssh
, SSH1_CMSG_AUTH_RSA
,
2531 PKT_BIGNUM
, s
->key
.modulus
, PKT_END
);
2533 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2534 logevent("Key refused");
2537 logevent("Received RSA challenge");
2538 ssh1_read_bignum(ssh
->pktin
.body
, &s
->challenge
);
2540 char *agentreq
, *q
, *ret
;
2543 len
= 1 + 4; /* message type, bit count */
2544 len
+= ssh1_bignum_length(s
->key
.exponent
);
2545 len
+= ssh1_bignum_length(s
->key
.modulus
);
2546 len
+= ssh1_bignum_length(s
->challenge
);
2547 len
+= 16; /* session id */
2548 len
+= 4; /* response format */
2549 agentreq
= smalloc(4 + len
);
2550 PUT_32BIT(agentreq
, len
);
2552 *q
++ = SSH1_AGENTC_RSA_CHALLENGE
;
2553 PUT_32BIT(q
, bignum_bitcount(s
->key
.modulus
));
2555 q
+= ssh1_write_bignum(q
, s
->key
.exponent
);
2556 q
+= ssh1_write_bignum(q
, s
->key
.modulus
);
2557 q
+= ssh1_write_bignum(q
, s
->challenge
);
2558 memcpy(q
, s
->session_id
, 16);
2560 PUT_32BIT(q
, 1); /* response format */
2561 agent_query(agentreq
, len
+ 4, &vret
, &retlen
);
2565 if (ret
[4] == SSH1_AGENT_RSA_RESPONSE
) {
2566 logevent("Sending Pageant's response");
2567 send_packet(ssh
, SSH1_CMSG_AUTH_RSA_RESPONSE
,
2568 PKT_DATA
, ret
+ 5, 16,
2572 if (ssh
->pktin
.type
== SSH1_SMSG_SUCCESS
) {
2574 ("Pageant's response accepted");
2575 if (flags
& FLAG_VERBOSE
) {
2576 c_write_str(ssh
, "Authenticated using"
2578 c_write(ssh
, s
->commentp
,
2580 c_write_str(ssh
, "\" from agent\r\n");
2585 ("Pageant's response not accepted");
2588 ("Pageant failed to answer challenge");
2592 logevent("No reply received from Pageant");
2595 freebn(s
->key
.exponent
);
2596 freebn(s
->key
.modulus
);
2597 freebn(s
->challenge
);
2605 if (*cfg
.keyfile
&& !s
->tried_publickey
)
2606 s
->pwpkt_type
= SSH1_CMSG_AUTH_RSA
;
2608 if (cfg
.try_tis_auth
&&
2609 (s
->supported_auths_mask
& (1 << SSH1_AUTH_TIS
)) &&
2610 !s
->tis_auth_refused
) {
2611 s
->pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
2612 logevent("Requested TIS authentication");
2613 send_packet(ssh
, SSH1_CMSG_AUTH_TIS
, PKT_END
);
2615 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
2616 logevent("TIS authentication declined");
2617 if (flags
& FLAG_INTERACTIVE
)
2618 c_write_str(ssh
, "TIS authentication refused.\r\n");
2619 s
->tis_auth_refused
= 1;
2622 int challengelen
= GET_32BIT(ssh
->pktin
.body
);
2623 logevent("Received TIS challenge");
2624 if (challengelen
> sizeof(s
->prompt
) - 1)
2625 challengelen
= sizeof(s
->prompt
) - 1;/* prevent overrun */
2626 memcpy(s
->prompt
, ssh
->pktin
.body
+ 4, challengelen
);
2627 /* Prompt heuristic comes from OpenSSH */
2628 strncpy(s
->prompt
+ challengelen
,
2629 memchr(s
->prompt
, '\n', challengelen
) ?
2630 "": "\r\nResponse: ",
2631 (sizeof s
->prompt
) - challengelen
);
2632 s
->prompt
[(sizeof s
->prompt
) - 1] = '\0';
2635 if (cfg
.try_tis_auth
&&
2636 (s
->supported_auths_mask
& (1 << SSH1_AUTH_CCARD
)) &&
2637 !s
->ccard_auth_refused
) {
2638 s
->pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
2639 logevent("Requested CryptoCard authentication");
2640 send_packet(ssh
, SSH1_CMSG_AUTH_CCARD
, PKT_END
);
2642 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
2643 logevent("CryptoCard authentication declined");
2644 c_write_str(ssh
, "CryptoCard authentication refused.\r\n");
2645 s
->ccard_auth_refused
= 1;
2648 int challengelen
= GET_32BIT(ssh
->pktin
.body
);
2649 logevent("Received CryptoCard challenge");
2650 if (challengelen
> sizeof(s
->prompt
) - 1)
2651 challengelen
= sizeof(s
->prompt
) - 1;/* prevent overrun */
2652 memcpy(s
->prompt
, ssh
->pktin
.body
+ 4, challengelen
);
2653 strncpy(s
->prompt
+ challengelen
,
2654 memchr(s
->prompt
, '\n', challengelen
) ?
2655 "" : "\r\nResponse: ",
2656 sizeof(s
->prompt
) - challengelen
);
2657 s
->prompt
[sizeof(s
->prompt
) - 1] = '\0';
2660 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2661 sprintf(s
->prompt
, "%.90s@%.90s's password: ",
2662 s
->username
, ssh
->savedhost
);
2664 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2665 char *comment
= NULL
;
2668 if (flags
& FLAG_VERBOSE
)
2669 c_write_str(ssh
, "Trying public key authentication.\r\n");
2670 logeventf(ssh
, "Trying public key \"%s\"", cfg
.keyfile
);
2671 type
= key_type(cfg
.keyfile
);
2672 if (type
!= SSH_KEYTYPE_SSH1
) {
2673 sprintf(msgbuf
, "Key is of wrong type (%s)",
2674 key_type_to_str(type
));
2676 c_write_str(ssh
, msgbuf
);
2677 c_write_str(ssh
, "\r\n");
2678 s
->tried_publickey
= 1;
2681 if (!rsakey_encrypted(cfg
.keyfile
, &comment
)) {
2682 if (flags
& FLAG_VERBOSE
)
2683 c_write_str(ssh
, "No passphrase required.\r\n");
2686 sprintf(s
->prompt
, "Passphrase for key \"%.100s\": ", comment
);
2691 * Show password prompt, having first obtained it via a TIS
2692 * or CryptoCard exchange if we're doing TIS or CryptoCard
2696 if (!ssh_get_line(s
->prompt
, s
->password
,
2697 sizeof(s
->password
), TRUE
)) {
2699 * get_line failed to get a password (for example
2700 * because one was supplied on the command line
2701 * which has already failed to work). Terminate.
2703 send_packet(ssh
, SSH1_MSG_DISCONNECT
,
2704 PKT_STR
, "No more passwords available to try",
2706 logevent("Unable to authenticate");
2707 connection_fatal(ssh
->frontend
, "Unable to authenticate");
2708 ssh
->state
= SSH_STATE_CLOSED
;
2712 /* Prompt may have come from server. We've munged it a bit, so
2713 * we know it to be zero-terminated at least once. */
2714 int ret
; /* need not be saved over crReturn */
2715 c_write_untrusted(ssh
, s
->prompt
, strlen(s
->prompt
));
2718 setup_userpass_input(ssh
, s
->password
, sizeof(s
->password
), 0);
2720 crWaitUntil(!ispkt
);
2721 ret
= process_userpass_input(ssh
, in
, inlen
);
2725 c_write_str(ssh
, "\r\n");
2729 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2731 * Try public key authentication with the specified
2734 s
->tried_publickey
= 1;
2737 int ret
= loadrsakey(cfg
.keyfile
, &s
->key
, s
->password
);
2739 c_write_str(ssh
, "Couldn't load private key from ");
2740 c_write_str(ssh
, cfg
.keyfile
);
2741 c_write_str(ssh
, ".\r\n");
2742 continue; /* go and try password */
2745 c_write_str(ssh
, "Wrong passphrase.\r\n");
2746 s
->tried_publickey
= 0;
2747 continue; /* try again */
2752 * Send a public key attempt.
2754 send_packet(ssh
, SSH1_CMSG_AUTH_RSA
,
2755 PKT_BIGNUM
, s
->key
.modulus
, PKT_END
);
2758 if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2759 c_write_str(ssh
, "Server refused our public key.\r\n");
2760 continue; /* go and try password */
2762 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2763 bombout((ssh
,"Bizarre response to offer of public key"));
2769 unsigned char buffer
[32];
2770 Bignum challenge
, response
;
2772 ssh1_read_bignum(ssh
->pktin
.body
, &challenge
);
2773 response
= rsadecrypt(challenge
, &s
->key
);
2774 freebn(s
->key
.private_exponent
);/* burn the evidence */
2776 for (i
= 0; i
< 32; i
++) {
2777 buffer
[i
] = bignum_byte(response
, 31 - i
);
2781 MD5Update(&md5c
, buffer
, 32);
2782 MD5Update(&md5c
, s
->session_id
, 16);
2783 MD5Final(buffer
, &md5c
);
2785 send_packet(ssh
, SSH1_CMSG_AUTH_RSA_RESPONSE
,
2786 PKT_DATA
, buffer
, 16, PKT_END
);
2793 if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2794 if (flags
& FLAG_VERBOSE
)
2795 c_write_str(ssh
, "Failed to authenticate with"
2796 " our public key.\r\n");
2797 continue; /* go and try password */
2798 } else if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2799 bombout((ssh
,"Bizarre response to RSA authentication response"));
2803 break; /* we're through! */
2805 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2807 * Defence against traffic analysis: we send a
2808 * whole bunch of packets containing strings of
2809 * different lengths. One of these strings is the
2810 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2811 * The others are all random data in
2812 * SSH1_MSG_IGNORE packets. This way a passive
2813 * listener can't tell which is the password, and
2814 * hence can't deduce the password length.
2816 * Anybody with a password length greater than 16
2817 * bytes is going to have enough entropy in their
2818 * password that a listener won't find it _that_
2819 * much help to know how long it is. So what we'll
2822 * - if password length < 16, we send 15 packets
2823 * containing string lengths 1 through 15
2825 * - otherwise, we let N be the nearest multiple
2826 * of 8 below the password length, and send 8
2827 * packets containing string lengths N through
2828 * N+7. This won't obscure the order of
2829 * magnitude of the password length, but it will
2830 * introduce a bit of extra uncertainty.
2832 * A few servers (the old 1.2.18 through 1.2.22)
2833 * can't deal with SSH1_MSG_IGNORE. For these
2834 * servers, we need an alternative defence. We make
2835 * use of the fact that the password is interpreted
2836 * as a C string: so we can append a NUL, then some
2839 * One server (a Cisco one) can deal with neither
2840 * SSH1_MSG_IGNORE _nor_ a padded password string.
2841 * For this server we are left with no defences
2842 * against password length sniffing.
2844 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
)) {
2846 * The server can deal with SSH1_MSG_IGNORE, so
2847 * we can use the primary defence.
2849 int bottom
, top
, pwlen
, i
;
2852 pwlen
= strlen(s
->password
);
2854 bottom
= 0; /* zero length passwords are OK! :-) */
2857 bottom
= pwlen
& ~7;
2861 assert(pwlen
>= bottom
&& pwlen
<= top
);
2863 randomstr
= smalloc(top
+ 1);
2865 for (i
= bottom
; i
<= top
; i
++) {
2867 defer_packet(ssh
, s
->pwpkt_type
,
2868 PKT_STR
, s
->password
, PKT_END
);
2870 for (j
= 0; j
< i
; j
++) {
2872 randomstr
[j
] = random_byte();
2873 } while (randomstr
[j
] == '\0');
2875 randomstr
[i
] = '\0';
2876 defer_packet(ssh
, SSH1_MSG_IGNORE
,
2877 PKT_STR
, randomstr
, PKT_END
);
2880 logevent("Sending password with camouflage packets");
2881 ssh_pkt_defersend(ssh
);
2883 else if (!(ssh
->remote_bugs
& BUG_NEEDS_SSH1_PLAIN_PASSWORD
)) {
2885 * The server can't deal with SSH1_MSG_IGNORE
2886 * but can deal with padded passwords, so we
2887 * can use the secondary defence.
2893 len
= strlen(s
->password
);
2894 if (len
< sizeof(string
)) {
2896 strcpy(string
, s
->password
);
2897 len
++; /* cover the zero byte */
2898 while (len
< sizeof(string
)) {
2899 string
[len
++] = (char) random_byte();
2904 logevent("Sending length-padded password");
2905 send_packet(ssh
, s
->pwpkt_type
, PKT_INT
, len
,
2906 PKT_DATA
, ss
, len
, PKT_END
);
2909 * The server has _both_
2910 * BUG_CHOKES_ON_SSH1_IGNORE and
2911 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2912 * therefore nothing we can do.
2915 len
= strlen(s
->password
);
2916 logevent("Sending unpadded password");
2917 send_packet(ssh
, s
->pwpkt_type
, PKT_INT
, len
,
2918 PKT_DATA
, s
->password
, len
, PKT_END
);
2921 send_packet(ssh
, s
->pwpkt_type
, PKT_STR
, s
->password
, PKT_END
);
2924 logevent("Sent password");
2925 memset(s
->password
, 0, strlen(s
->password
));
2927 if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2928 if (flags
& FLAG_VERBOSE
)
2929 c_write_str(ssh
, "Access denied\r\n");
2930 logevent("Authentication refused");
2931 } else if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2932 bombout((ssh
,"Strange packet received, type %d", ssh
->pktin
.type
));
2937 logevent("Authentication successful");
2942 void sshfwd_close(struct ssh_channel
*c
)
2946 if (c
&& !c
->closes
) {
2948 * If the channel's remoteid is -1, we have sent
2949 * CHANNEL_OPEN for this channel, but it hasn't even been
2950 * acknowledged by the server. So we must set a close flag
2951 * on it now, and then when the server acks the channel
2952 * open, we can close it then.
2954 if (((int)c
->remoteid
) != -1) {
2955 if (ssh
->version
== 1) {
2956 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
2959 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_CLOSE
);
2960 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
2964 c
->closes
= 1; /* sent MSG_CLOSE */
2965 if (c
->type
== CHAN_X11
) {
2967 logevent("Forwarded X11 connection terminated");
2968 } else if (c
->type
== CHAN_SOCKDATA
||
2969 c
->type
== CHAN_SOCKDATA_DORMANT
) {
2971 logevent("Forwarded port closed");
2976 int sshfwd_write(struct ssh_channel
*c
, char *buf
, int len
)
2980 if (ssh
->version
== 1) {
2981 send_packet(ssh
, SSH1_MSG_CHANNEL_DATA
,
2982 PKT_INT
, c
->remoteid
,
2983 PKT_INT
, len
, PKT_DATA
, buf
, len
, PKT_END
);
2985 * In SSH1 we can return 0 here - implying that forwarded
2986 * connections are never individually throttled - because
2987 * the only circumstance that can cause throttling will be
2988 * the whole SSH connection backing up, in which case
2989 * _everything_ will be throttled as a whole.
2993 ssh2_add_channel_data(c
, buf
, len
);
2994 return ssh2_try_send(c
);
2998 void sshfwd_unthrottle(struct ssh_channel
*c
, int bufsize
)
3002 if (ssh
->version
== 1) {
3003 if (c
->v
.v1
.throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
3004 c
->v
.v1
.throttling
= 0;
3005 ssh1_throttle(ssh
, -1);
3008 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
3012 static void ssh1_protocol(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
3014 crBegin(ssh
->ssh1_protocol_crstate
);
3018 while (!do_ssh1_login(ssh
, in
, inlen
, ispkt
)) {
3021 if (ssh
->state
== SSH_STATE_CLOSED
)
3024 if (cfg
.agentfwd
&& agent_exists()) {
3025 logevent("Requesting agent forwarding");
3026 send_packet(ssh
, SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
3030 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3031 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3032 bombout((ssh
,"Protocol confusion"));
3034 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3035 logevent("Agent forwarding refused");
3037 logevent("Agent forwarding enabled");
3038 ssh
->agentfwd_enabled
= TRUE
;
3042 if (cfg
.x11_forward
) {
3043 char proto
[20], data
[64];
3044 logevent("Requesting X11 forwarding");
3045 ssh
->x11auth
= x11_invent_auth(proto
, sizeof(proto
),
3046 data
, sizeof(data
));
3047 if (ssh
->v1_local_protoflags
& SSH1_PROTOFLAG_SCREEN_NUMBER
) {
3048 send_packet(ssh
, SSH1_CMSG_X11_REQUEST_FORWARDING
,
3049 PKT_STR
, proto
, PKT_STR
, data
,
3050 PKT_INT
, 0, PKT_END
);
3052 send_packet(ssh
, SSH1_CMSG_X11_REQUEST_FORWARDING
,
3053 PKT_STR
, proto
, PKT_STR
, data
, PKT_END
);
3058 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3059 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3060 bombout((ssh
,"Protocol confusion"));
3062 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3063 logevent("X11 forwarding refused");
3065 logevent("X11 forwarding enabled");
3066 ssh
->X11_fwd_enabled
= TRUE
;
3073 int sport
,dport
,sserv
,dserv
;
3074 char sports
[256], dports
[256], saddr
[256], host
[256];
3076 ssh
->rportfwds
= newtree234(ssh_rportcmp_ssh1
);
3077 /* Add port forwardings. */
3078 ssh
->portfwd_strptr
= cfg
.portfwd
;
3079 while (*ssh
->portfwd_strptr
) {
3080 type
= *ssh
->portfwd_strptr
++;
3083 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= '\t') {
3084 if (*ssh
->portfwd_strptr
== ':') {
3086 * We've seen a colon in the middle of the
3087 * source port number. This means that
3088 * everything we've seen until now is the
3089 * source _address_, so we'll move it into
3090 * saddr and start sports from the beginning
3093 ssh
->portfwd_strptr
++;
3095 strcpy(saddr
, sports
);
3098 if (n
< 255) sports
[n
++] = *ssh
->portfwd_strptr
++;
3101 if (*ssh
->portfwd_strptr
== '\t')
3102 ssh
->portfwd_strptr
++;
3104 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= ':') {
3105 if (n
< 255) host
[n
++] = *ssh
->portfwd_strptr
++;
3108 if (*ssh
->portfwd_strptr
== ':')
3109 ssh
->portfwd_strptr
++;
3111 while (*ssh
->portfwd_strptr
) {
3112 if (n
< 255) dports
[n
++] = *ssh
->portfwd_strptr
++;
3115 ssh
->portfwd_strptr
++;
3116 dport
= atoi(dports
);
3120 dport
= net_service_lookup(dports
);
3122 logeventf(ssh
, "Service lookup failed for"
3123 " destination port \"%s\"", dports
);
3126 sport
= atoi(sports
);
3130 sport
= net_service_lookup(sports
);
3132 logeventf(ssh
, "Service lookup failed for source"
3133 " port \"%s\"", sports
);
3136 if (sport
&& dport
) {
3138 pfd_addforward(host
, dport
, *saddr ? saddr
: NULL
,
3140 logeventf(ssh
, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3141 " forwarding to %s:%.*s%.*s%d%.*s",
3142 (int)(*saddr?
strlen(saddr
):0), *saddr?saddr
:NULL
,
3143 (int)(*saddr?
1:0), ":",
3144 (int)(sserv ?
strlen(sports
) : 0), sports
,
3145 sserv
, "(", sport
, sserv
, ")",
3147 (int)(dserv ?
strlen(dports
) : 0), dports
,
3148 dserv
, "(", dport
, dserv
, ")");
3150 struct ssh_rportfwd
*pf
;
3151 pf
= smalloc(sizeof(*pf
));
3152 strcpy(pf
->dhost
, host
);
3156 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
3159 if (add234(ssh
->rportfwds
, pf
) != pf
) {
3161 "Duplicate remote port forwarding to %s:%d",
3165 logeventf(ssh
, "Requesting remote port %.*s%.*s%d%.*s"
3166 " forward to %s:%.*s%.*s%d%.*s",
3167 (int)(sserv ?
strlen(sports
) : 0), sports
,
3168 sserv
, "(", sport
, sserv
, ")",
3170 (int)(dserv ?
strlen(dports
) : 0), dports
,
3171 dserv
, "(", dport
, dserv
, ")");
3172 send_packet(ssh
, SSH1_CMSG_PORT_FORWARD_REQUEST
,
3180 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3181 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3182 bombout((ssh
,"Protocol confusion"));
3184 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3185 c_write_str(ssh
, "Server refused port"
3188 logevent("Remote port forwarding enabled");
3196 send_packet(ssh
, SSH1_CMSG_REQUEST_PTY
,
3197 PKT_STR
, cfg
.termtype
,
3198 PKT_INT
, ssh
->term_height
,
3199 PKT_INT
, ssh
->term_width
,
3200 PKT_INT
, 0, PKT_INT
, 0, PKT_CHAR
, 0, PKT_END
);
3201 ssh
->state
= SSH_STATE_INTERMED
;
3205 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3206 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3207 bombout((ssh
,"Protocol confusion"));
3209 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3210 c_write_str(ssh
, "Server refused to allocate pty\r\n");
3211 ssh
->editing
= ssh
->echoing
= 1;
3213 logevent("Allocated pty");
3215 ssh
->editing
= ssh
->echoing
= 1;
3218 if (cfg
.compression
) {
3219 send_packet(ssh
, SSH1_CMSG_REQUEST_COMPRESSION
, PKT_INT
, 6, PKT_END
);
3223 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3224 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3225 bombout((ssh
,"Protocol confusion"));
3227 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3228 c_write_str(ssh
, "Server refused to compress\r\n");
3230 logevent("Started compression");
3231 ssh
->v1_compressing
= TRUE
;
3232 ssh
->cs_comp_ctx
= zlib_compress_init();
3233 logevent("Initialised zlib (RFC1950) compression");
3234 ssh
->sc_comp_ctx
= zlib_decompress_init();
3235 logevent("Initialised zlib (RFC1950) decompression");
3239 * Start the shell or command.
3241 * Special case: if the first-choice command is an SSH2
3242 * subsystem (hence not usable here) and the second choice
3243 * exists, we fall straight back to that.
3246 char *cmd
= cfg
.remote_cmd_ptr
;
3248 if (cfg
.ssh_subsys
&& cfg
.remote_cmd_ptr2
) {
3249 cmd
= cfg
.remote_cmd_ptr2
;
3250 ssh
->fallback_cmd
= TRUE
;
3253 send_packet(ssh
, SSH1_CMSG_EXEC_CMD
, PKT_STR
, cmd
, PKT_END
);
3255 send_packet(ssh
, SSH1_CMSG_EXEC_SHELL
, PKT_END
);
3256 logevent("Started session");
3259 ssh
->state
= SSH_STATE_SESSION
;
3260 if (ssh
->size_needed
)
3261 ssh_size(ssh
, ssh
->term_width
, ssh
->term_height
);
3262 if (ssh
->eof_needed
)
3263 ssh_special(ssh
, TS_EOF
);
3266 ldisc_send(ssh
->ldisc
, NULL
, 0, 0);/* cause ldisc to notice changes */
3268 ssh
->channels
= newtree234(ssh_channelcmp
);
3272 if (ssh
->pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
3273 ssh
->pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
3274 long len
= GET_32BIT(ssh
->pktin
.body
);
3276 from_backend(ssh
->frontend
,
3277 ssh
->pktin
.type
== SSH1_SMSG_STDERR_DATA
,
3278 ssh
->pktin
.body
+ 4, len
);
3279 if (!ssh
->v1_stdout_throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
3280 ssh
->v1_stdout_throttling
= 1;
3281 ssh1_throttle(ssh
, +1);
3283 } else if (ssh
->pktin
.type
== SSH1_MSG_DISCONNECT
) {
3284 ssh
->state
= SSH_STATE_CLOSED
;
3285 logevent("Received disconnect request");
3287 } else if (ssh
->pktin
.type
== SSH1_SMSG_X11_OPEN
) {
3288 /* Remote side is trying to open a channel to talk to our
3289 * X-Server. Give them back a local channel number. */
3290 struct ssh_channel
*c
;
3292 logevent("Received X11 connect request");
3293 /* Refuse if X11 forwarding is disabled. */
3294 if (!ssh
->X11_fwd_enabled
) {
3295 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3296 PKT_INT
, GET_32BIT(ssh
->pktin
.body
), PKT_END
);
3297 logevent("Rejected X11 connect request");
3299 c
= smalloc(sizeof(struct ssh_channel
));
3302 if (x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
,
3303 ssh
->x11auth
) != NULL
) {
3304 logevent("opening X11 forward connection failed");
3306 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3307 PKT_INT
, GET_32BIT(ssh
->pktin
.body
),
3311 ("opening X11 forward connection succeeded");
3312 c
->remoteid
= GET_32BIT(ssh
->pktin
.body
);
3313 c
->localid
= alloc_channel_id(ssh
);
3315 c
->v
.v1
.throttling
= 0;
3316 c
->type
= CHAN_X11
; /* identify channel type */
3317 add234(ssh
->channels
, c
);
3318 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3319 PKT_INT
, c
->remoteid
, PKT_INT
,
3320 c
->localid
, PKT_END
);
3321 logevent("Opened X11 forward channel");
3324 } else if (ssh
->pktin
.type
== SSH1_SMSG_AGENT_OPEN
) {
3325 /* Remote side is trying to open a channel to talk to our
3326 * agent. Give them back a local channel number. */
3327 struct ssh_channel
*c
;
3329 /* Refuse if agent forwarding is disabled. */
3330 if (!ssh
->agentfwd_enabled
) {
3331 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3332 PKT_INT
, GET_32BIT(ssh
->pktin
.body
), PKT_END
);
3334 c
= smalloc(sizeof(struct ssh_channel
));
3336 c
->remoteid
= GET_32BIT(ssh
->pktin
.body
);
3337 c
->localid
= alloc_channel_id(ssh
);
3339 c
->v
.v1
.throttling
= 0;
3340 c
->type
= CHAN_AGENT
; /* identify channel type */
3341 c
->u
.a
.lensofar
= 0;
3342 add234(ssh
->channels
, c
);
3343 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3344 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
3347 } else if (ssh
->pktin
.type
== SSH1_MSG_PORT_OPEN
) {
3348 /* Remote side is trying to open a channel to talk to a
3349 * forwarded port. Give them back a local channel number. */
3350 struct ssh_channel
*c
;
3351 struct ssh_rportfwd pf
;
3353 char host
[256], buf
[1024];
3355 c
= smalloc(sizeof(struct ssh_channel
));
3358 hostsize
= GET_32BIT(ssh
->pktin
.body
+4);
3359 for(h
= host
, p
= ssh
->pktin
.body
+8; hostsize
!= 0; hostsize
--) {
3360 if (h
+1 < host
+sizeof(host
))
3365 port
= GET_32BIT(p
);
3367 strcpy(pf
.dhost
, host
);
3370 if (find234(ssh
->rportfwds
, &pf
, NULL
) == NULL
) {
3371 sprintf(buf
, "Rejected remote port open request for %s:%d",
3374 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3375 PKT_INT
, GET_32BIT(ssh
->pktin
.body
), PKT_END
);
3377 sprintf(buf
, "Received remote port open request for %s:%d",
3380 e
= pfd_newconnect(&c
->u
.pfd
.s
, host
, port
, c
);
3383 sprintf(buf
, "Port open failed: %s", e
);
3386 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3387 PKT_INT
, GET_32BIT(ssh
->pktin
.body
),
3390 c
->remoteid
= GET_32BIT(ssh
->pktin
.body
);
3391 c
->localid
= alloc_channel_id(ssh
);
3393 c
->v
.v1
.throttling
= 0;
3394 c
->type
= CHAN_SOCKDATA
; /* identify channel type */
3395 add234(ssh
->channels
, c
);
3396 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3397 PKT_INT
, c
->remoteid
, PKT_INT
,
3398 c
->localid
, PKT_END
);
3399 logevent("Forwarded port opened successfully");
3403 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
) {
3404 unsigned int remoteid
= GET_32BIT(ssh
->pktin
.body
);
3405 unsigned int localid
= GET_32BIT(ssh
->pktin
.body
+4);
3406 struct ssh_channel
*c
;
3408 c
= find234(ssh
->channels
, &remoteid
, ssh_channelfind
);
3409 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
3410 c
->remoteid
= localid
;
3411 c
->type
= CHAN_SOCKDATA
;
3412 c
->v
.v1
.throttling
= 0;
3413 pfd_confirm(c
->u
.pfd
.s
);
3416 if (c
&& c
->closes
) {
3418 * We have a pending close on this channel,
3419 * which we decided on before the server acked
3420 * the channel open. So now we know the
3421 * remoteid, we can close it again.
3423 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE
,
3424 PKT_INT
, c
->remoteid
, PKT_END
);
3427 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_OPEN_FAILURE
) {
3428 unsigned int remoteid
= GET_32BIT(ssh
->pktin
.body
);
3429 struct ssh_channel
*c
;
3431 c
= find234(ssh
->channels
, &remoteid
, ssh_channelfind
);
3432 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
3433 logevent("Forwarded connection refused by server");
3434 pfd_close(c
->u
.pfd
.s
);
3435 del234(ssh
->channels
, c
);
3439 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE
||
3440 ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
) {
3441 /* Remote side closes a channel. */
3442 unsigned i
= GET_32BIT(ssh
->pktin
.body
);
3443 struct ssh_channel
*c
;
3444 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
3445 if (c
&& ((int)c
->remoteid
) != -1) {
3448 (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
1 : 2);
3450 if ((c
->closes
== 0) && (c
->type
== CHAN_X11
)) {
3451 logevent("Forwarded X11 connection terminated");
3452 assert(c
->u
.x11
.s
!= NULL
);
3453 x11_close(c
->u
.x11
.s
);
3456 if ((c
->closes
== 0) && (c
->type
== CHAN_SOCKDATA
)) {
3457 logevent("Forwarded port closed");
3458 assert(c
->u
.pfd
.s
!= NULL
);
3459 pfd_close(c
->u
.pfd
.s
);
3463 c
->closes
|= (closetype
<< 2); /* seen this message */
3464 if (!(c
->closes
& closetype
)) {
3465 send_packet(ssh
, ssh
->pktin
.type
, PKT_INT
, c
->remoteid
,
3467 c
->closes
|= closetype
; /* sent it too */
3470 if (c
->closes
== 15) {
3471 del234(ssh
->channels
, c
);
3475 bombout((ssh
,"Received CHANNEL_CLOSE%s for %s channel %d\n",
3476 ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
"" :
3477 "_CONFIRMATION", c ?
"half-open" : "nonexistent",
3480 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_DATA
) {
3481 /* Data sent down one of our channels. */
3482 int i
= GET_32BIT(ssh
->pktin
.body
);
3483 int len
= GET_32BIT(ssh
->pktin
.body
+ 4);
3484 unsigned char *p
= ssh
->pktin
.body
+ 8;
3485 struct ssh_channel
*c
;
3486 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
3491 bufsize
= x11_send(c
->u
.x11
.s
, p
, len
);
3494 bufsize
= pfd_send(c
->u
.pfd
.s
, p
, len
);
3497 /* Data for an agent message. Buffer it. */
3499 if (c
->u
.a
.lensofar
< 4) {
3500 int l
= min(4 - c
->u
.a
.lensofar
, len
);
3501 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
,
3505 c
->u
.a
.lensofar
+= l
;
3507 if (c
->u
.a
.lensofar
== 4) {
3509 4 + GET_32BIT(c
->u
.a
.msglen
);
3510 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
3511 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
3513 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
3515 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
3517 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
,
3521 c
->u
.a
.lensofar
+= l
;
3523 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
3524 void *reply
, *sentreply
;
3526 agent_query(c
->u
.a
.message
,
3527 c
->u
.a
.totallen
, &reply
,
3532 /* Fake SSH_AGENT_FAILURE. */
3533 sentreply
= "\0\0\0\1\5";
3536 send_packet(ssh
, SSH1_MSG_CHANNEL_DATA
,
3537 PKT_INT
, c
->remoteid
,
3539 PKT_DATA
, sentreply
, replylen
,
3543 sfree(c
->u
.a
.message
);
3544 c
->u
.a
.lensofar
= 0;
3547 bufsize
= 0; /* agent channels never back up */
3550 if (!c
->v
.v1
.throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
3551 c
->v
.v1
.throttling
= 1;
3552 ssh1_throttle(ssh
, +1);
3555 } else if (ssh
->pktin
.type
== SSH1_SMSG_SUCCESS
) {
3556 /* may be from EXEC_SHELL on some servers */
3557 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3558 /* may be from EXEC_SHELL on some servers
3559 * if no pty is available or in other odd cases. Ignore */
3560 } else if (ssh
->pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
3562 ssh
->exitcode
= GET_32BIT(ssh
->pktin
.body
);
3563 sprintf(buf
, "Server sent command exit status %d",
3566 send_packet(ssh
, SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
3568 * In case `helpful' firewalls or proxies tack
3569 * extra human-readable text on the end of the
3570 * session which we might mistake for another
3571 * encrypted packet, we close the session once
3572 * we've sent EXIT_CONFIRMATION.
3574 ssh
->state
= SSH_STATE_CLOSED
;
3577 bombout((ssh
,"Strange packet received: type %d", ssh
->pktin
.type
));
3582 int len
= min(inlen
, 512);
3583 send_packet(ssh
, SSH1_CMSG_STDIN_DATA
,
3584 PKT_INT
, len
, PKT_DATA
, in
, len
, PKT_END
);
3595 * Utility routine for decoding comma-separated strings in KEXINIT.
3597 static int in_commasep_string(char *needle
, char *haystack
, int haylen
)
3600 if (!needle
|| !haystack
) /* protect against null pointers */
3602 needlen
= strlen(needle
);
3605 * Is it at the start of the string?
3607 if (haylen
>= needlen
&& /* haystack is long enough */
3608 !memcmp(needle
, haystack
, needlen
) && /* initial match */
3609 (haylen
== needlen
|| haystack
[needlen
] == ',')
3610 /* either , or EOS follows */
3614 * If not, search for the next comma and resume after that.
3615 * If no comma found, terminate.
3617 while (haylen
> 0 && *haystack
!= ',')
3618 haylen
--, haystack
++;
3621 haylen
--, haystack
++; /* skip over comma itself */
3626 * SSH2 key creation method.
3628 static void ssh2_mkkey(Ssh ssh
, Bignum K
, char *H
, char *sessid
, char chr
,
3632 /* First 20 bytes. */
3634 if (!(ssh
->remote_bugs
& BUG_SSH2_DERIVEKEY
))
3636 SHA_Bytes(&s
, H
, 20);
3637 SHA_Bytes(&s
, &chr
, 1);
3638 SHA_Bytes(&s
, sessid
, 20);
3639 SHA_Final(&s
, keyspace
);
3640 /* Next 20 bytes. */
3642 if (!(ssh
->remote_bugs
& BUG_SSH2_DERIVEKEY
))
3644 SHA_Bytes(&s
, H
, 20);
3645 SHA_Bytes(&s
, keyspace
, 20);
3646 SHA_Final(&s
, keyspace
+ 20);
3650 * Handle the SSH2 transport layer.
3652 static int do_ssh2_transport(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
3654 struct do_ssh2_transport_state
{
3655 int nbits
, pbits
, warn
;
3656 Bignum p
, g
, e
, f
, K
;
3657 int kex_init_value
, kex_reply_value
;
3658 const struct ssh_mac
**maclist
;
3660 const struct ssh2_cipher
*cscipher_tobe
;
3661 const struct ssh2_cipher
*sccipher_tobe
;
3662 const struct ssh_mac
*csmac_tobe
;
3663 const struct ssh_mac
*scmac_tobe
;
3664 const struct ssh_compress
*cscomp_tobe
;
3665 const struct ssh_compress
*sccomp_tobe
;
3666 char *hostkeydata
, *sigdata
, *keystr
, *fingerprint
;
3667 int hostkeylen
, siglen
;
3668 void *hkey
; /* actual host key */
3669 unsigned char exchange_hash
[20];
3670 int n_preferred_ciphers
;
3671 const struct ssh2_ciphers
*preferred_ciphers
[CIPHER_MAX
];
3672 const struct ssh_compress
*preferred_comp
;
3675 crState(do_ssh2_transport_state
);
3677 crBegin(ssh
->do_ssh2_transport_crstate
);
3679 s
->cscipher_tobe
= s
->sccipher_tobe
= NULL
;
3680 s
->csmac_tobe
= s
->scmac_tobe
= NULL
;
3681 s
->cscomp_tobe
= s
->sccomp_tobe
= NULL
;
3689 * Set up the preferred ciphers. (NULL => warn below here)
3691 s
->n_preferred_ciphers
= 0;
3692 for (i
= 0; i
< CIPHER_MAX
; i
++) {
3693 switch (cfg
.ssh_cipherlist
[i
]) {
3694 case CIPHER_BLOWFISH
:
3695 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_blowfish
;
3698 if (cfg
.ssh2_des_cbc
) {
3699 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_des
;
3703 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_3des
;
3706 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_aes
;
3709 /* Flag for later. Don't bother if it's the last in
3711 if (i
< CIPHER_MAX
- 1) {
3712 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = NULL
;
3720 * Set up preferred compression.
3722 if (cfg
.compression
)
3723 s
->preferred_comp
= &ssh_zlib
;
3725 s
->preferred_comp
= &ssh_comp_none
;
3728 * Be prepared to work around the buggy MAC problem.
3730 if (ssh
->remote_bugs
& BUG_SSH2_HMAC
)
3731 s
->maclist
= buggymacs
, s
->nmacs
= lenof(buggymacs
);
3733 s
->maclist
= macs
, s
->nmacs
= lenof(macs
);
3737 int i
, j
, cipherstr_started
;
3740 * Construct and send our key exchange packet.
3742 ssh2_pkt_init(ssh
, SSH2_MSG_KEXINIT
);
3743 for (i
= 0; i
< 16; i
++)
3744 ssh2_pkt_addbyte(ssh
, (unsigned char) random_byte());
3745 /* List key exchange algorithms. */
3746 ssh2_pkt_addstring_start(ssh
);
3747 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3748 if (kex_algs
[i
] == &ssh_diffiehellman_gex
&&
3749 (ssh
->remote_bugs
& BUG_SSH2_DH_GEX
))
3751 ssh2_pkt_addstring_str(ssh
, kex_algs
[i
]->name
);
3752 if (i
< lenof(kex_algs
) - 1)
3753 ssh2_pkt_addstring_str(ssh
, ",");
3755 /* List server host key algorithms. */
3756 ssh2_pkt_addstring_start(ssh
);
3757 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3758 ssh2_pkt_addstring_str(ssh
, hostkey_algs
[i
]->name
);
3759 if (i
< lenof(hostkey_algs
) - 1)
3760 ssh2_pkt_addstring_str(ssh
, ",");
3762 /* List client->server encryption algorithms. */
3763 ssh2_pkt_addstring_start(ssh
);
3764 cipherstr_started
= 0;
3765 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
3766 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
3767 if (!c
) continue; /* warning flag */
3768 for (j
= 0; j
< c
->nciphers
; j
++) {
3769 if (cipherstr_started
)
3770 ssh2_pkt_addstring_str(ssh
, ",");
3771 ssh2_pkt_addstring_str(ssh
, c
->list
[j
]->name
);
3772 cipherstr_started
= 1;
3775 /* List server->client encryption algorithms. */
3776 ssh2_pkt_addstring_start(ssh
);
3777 cipherstr_started
= 0;
3778 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
3779 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
3780 if (!c
) continue; /* warning flag */
3781 for (j
= 0; j
< c
->nciphers
; j
++) {
3782 if (cipherstr_started
)
3783 ssh2_pkt_addstring_str(ssh
, ",");
3784 ssh2_pkt_addstring_str(ssh
, c
->list
[j
]->name
);
3785 cipherstr_started
= 1;
3788 /* List client->server MAC algorithms. */
3789 ssh2_pkt_addstring_start(ssh
);
3790 for (i
= 0; i
< s
->nmacs
; i
++) {
3791 ssh2_pkt_addstring_str(ssh
, s
->maclist
[i
]->name
);
3792 if (i
< s
->nmacs
- 1)
3793 ssh2_pkt_addstring_str(ssh
, ",");
3795 /* List server->client MAC algorithms. */
3796 ssh2_pkt_addstring_start(ssh
);
3797 for (i
= 0; i
< s
->nmacs
; i
++) {
3798 ssh2_pkt_addstring_str(ssh
, s
->maclist
[i
]->name
);
3799 if (i
< s
->nmacs
- 1)
3800 ssh2_pkt_addstring_str(ssh
, ",");
3802 /* List client->server compression algorithms. */
3803 ssh2_pkt_addstring_start(ssh
);
3804 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3805 const struct ssh_compress
*c
=
3806 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
3807 ssh2_pkt_addstring_str(ssh
, c
->name
);
3808 if (i
< lenof(compressions
))
3809 ssh2_pkt_addstring_str(ssh
, ",");
3811 /* List server->client compression algorithms. */
3812 ssh2_pkt_addstring_start(ssh
);
3813 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3814 const struct ssh_compress
*c
=
3815 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
3816 ssh2_pkt_addstring_str(ssh
, c
->name
);
3817 if (i
< lenof(compressions
))
3818 ssh2_pkt_addstring_str(ssh
, ",");
3820 /* List client->server languages. Empty list. */
3821 ssh2_pkt_addstring_start(ssh
);
3822 /* List server->client languages. Empty list. */
3823 ssh2_pkt_addstring_start(ssh
);
3824 /* First KEX packet does _not_ follow, because we're not that brave. */
3825 ssh2_pkt_addbool(ssh
, FALSE
);
3827 ssh2_pkt_adduint32(ssh
, 0);
3830 ssh
->exhash
= ssh
->exhashbase
;
3831 sha_string(&ssh
->exhash
, ssh
->pktout
.data
+ 5, ssh
->pktout
.length
- 5);
3837 if (ssh
->pktin
.length
> 5)
3838 sha_string(&ssh
->exhash
, ssh
->pktin
.data
+ 5, ssh
->pktin
.length
- 5);
3841 * Now examine the other side's KEXINIT to see what we're up
3848 if (ssh
->pktin
.type
!= SSH2_MSG_KEXINIT
) {
3849 bombout((ssh
,"expected key exchange packet from server"));
3853 ssh
->hostkey
= NULL
;
3854 s
->cscipher_tobe
= NULL
;
3855 s
->sccipher_tobe
= NULL
;
3856 s
->csmac_tobe
= NULL
;
3857 s
->scmac_tobe
= NULL
;
3858 s
->cscomp_tobe
= NULL
;
3859 s
->sccomp_tobe
= NULL
;
3860 ssh
->pktin
.savedpos
+= 16; /* skip garbage cookie */
3861 ssh2_pkt_getstring(ssh
, &str
, &len
); /* key exchange algorithms */
3862 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3863 if (kex_algs
[i
] == &ssh_diffiehellman_gex
&&
3864 (ssh
->remote_bugs
& BUG_SSH2_DH_GEX
))
3866 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
3867 ssh
->kex
= kex_algs
[i
];
3871 ssh2_pkt_getstring(ssh
, &str
, &len
); /* host key algorithms */
3872 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3873 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
3874 ssh
->hostkey
= hostkey_algs
[i
];
3878 ssh2_pkt_getstring(ssh
, &str
, &len
); /* client->server cipher */
3880 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
3881 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
3885 for (j
= 0; j
< c
->nciphers
; j
++) {
3886 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3887 s
->cscipher_tobe
= c
->list
[j
];
3892 if (s
->cscipher_tobe
) {
3894 askcipher(ssh
->frontend
, s
->cscipher_tobe
->name
, 1);
3898 if (!s
->cscipher_tobe
) {
3899 bombout((ssh
,"Couldn't agree a client-to-server cipher (available: %s)",
3900 str ? str
: "(null)"));
3904 ssh2_pkt_getstring(ssh
, &str
, &len
); /* server->client cipher */
3906 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
3907 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
3911 for (j
= 0; j
< c
->nciphers
; j
++) {
3912 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3913 s
->sccipher_tobe
= c
->list
[j
];
3918 if (s
->sccipher_tobe
) {
3920 askcipher(ssh
->frontend
, s
->sccipher_tobe
->name
, 2);
3924 if (!s
->sccipher_tobe
) {
3925 bombout((ssh
,"Couldn't agree a server-to-client cipher (available: %s)",
3926 str ? str
: "(null)"));
3930 ssh2_pkt_getstring(ssh
, &str
, &len
); /* client->server mac */
3931 for (i
= 0; i
< s
->nmacs
; i
++) {
3932 if (in_commasep_string(s
->maclist
[i
]->name
, str
, len
)) {
3933 s
->csmac_tobe
= s
->maclist
[i
];
3937 ssh2_pkt_getstring(ssh
, &str
, &len
); /* server->client mac */
3938 for (i
= 0; i
< s
->nmacs
; i
++) {
3939 if (in_commasep_string(s
->maclist
[i
]->name
, str
, len
)) {
3940 s
->scmac_tobe
= s
->maclist
[i
];
3944 ssh2_pkt_getstring(ssh
, &str
, &len
); /* client->server compression */
3945 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3946 const struct ssh_compress
*c
=
3947 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
3948 if (in_commasep_string(c
->name
, str
, len
)) {
3953 ssh2_pkt_getstring(ssh
, &str
, &len
); /* server->client compression */
3954 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3955 const struct ssh_compress
*c
=
3956 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
3957 if (in_commasep_string(c
->name
, str
, len
)) {
3965 * Work out the number of bits of key we will need from the key
3966 * exchange. We start with the maximum key length of either
3972 csbits
= s
->cscipher_tobe
->keylen
;
3973 scbits
= s
->sccipher_tobe
->keylen
;
3974 s
->nbits
= (csbits
> scbits ? csbits
: scbits
);
3976 /* The keys only have 160-bit entropy, since they're based on
3977 * a SHA-1 hash. So cap the key size at 160 bits. */
3982 * If we're doing Diffie-Hellman group exchange, start by
3983 * requesting a group.
3985 if (ssh
->kex
== &ssh_diffiehellman_gex
) {
3986 logevent("Doing Diffie-Hellman group exchange");
3987 ssh
->pkt_ctx
|= SSH2_PKTCTX_DHGEX
;
3989 * Work out how big a DH group we will need to allow that
3992 s
->pbits
= 512 << ((s
->nbits
- 1) / 64);
3993 ssh2_pkt_init(ssh
, SSH2_MSG_KEX_DH_GEX_REQUEST
);
3994 ssh2_pkt_adduint32(ssh
, s
->pbits
);
3998 if (ssh
->pktin
.type
!= SSH2_MSG_KEX_DH_GEX_GROUP
) {
3999 bombout((ssh
,"expected key exchange group packet from server"));
4002 s
->p
= ssh2_pkt_getmp(ssh
);
4003 s
->g
= ssh2_pkt_getmp(ssh
);
4004 ssh
->kex_ctx
= dh_setup_group(s
->p
, s
->g
);
4005 s
->kex_init_value
= SSH2_MSG_KEX_DH_GEX_INIT
;
4006 s
->kex_reply_value
= SSH2_MSG_KEX_DH_GEX_REPLY
;
4008 ssh
->pkt_ctx
|= SSH2_PKTCTX_DHGROUP1
;
4009 ssh
->kex_ctx
= dh_setup_group1();
4010 s
->kex_init_value
= SSH2_MSG_KEXDH_INIT
;
4011 s
->kex_reply_value
= SSH2_MSG_KEXDH_REPLY
;
4014 logevent("Doing Diffie-Hellman key exchange");
4016 * Now generate and send e for Diffie-Hellman.
4018 s
->e
= dh_create_e(ssh
->kex_ctx
, s
->nbits
* 2);
4019 ssh2_pkt_init(ssh
, s
->kex_init_value
);
4020 ssh2_pkt_addmp(ssh
, s
->e
);
4024 if (ssh
->pktin
.type
!= s
->kex_reply_value
) {
4025 bombout((ssh
,"expected key exchange reply packet from server"));
4028 ssh2_pkt_getstring(ssh
, &s
->hostkeydata
, &s
->hostkeylen
);
4029 s
->f
= ssh2_pkt_getmp(ssh
);
4030 ssh2_pkt_getstring(ssh
, &s
->sigdata
, &s
->siglen
);
4032 s
->K
= dh_find_K(ssh
->kex_ctx
, s
->f
);
4034 sha_string(&ssh
->exhash
, s
->hostkeydata
, s
->hostkeylen
);
4035 if (ssh
->kex
== &ssh_diffiehellman_gex
) {
4036 sha_uint32(&ssh
->exhash
, s
->pbits
);
4037 sha_mpint(&ssh
->exhash
, s
->p
);
4038 sha_mpint(&ssh
->exhash
, s
->g
);
4040 sha_mpint(&ssh
->exhash
, s
->e
);
4041 sha_mpint(&ssh
->exhash
, s
->f
);
4042 sha_mpint(&ssh
->exhash
, s
->K
);
4043 SHA_Final(&ssh
->exhash
, s
->exchange_hash
);
4045 dh_cleanup(ssh
->kex_ctx
);
4048 debug(("Exchange hash is:\n"));
4049 dmemdump(s
->exchange_hash
, 20);
4052 s
->hkey
= ssh
->hostkey
->newkey(s
->hostkeydata
, s
->hostkeylen
);
4054 !ssh
->hostkey
->verifysig(s
->hkey
, s
->sigdata
, s
->siglen
,
4055 s
->exchange_hash
, 20)) {
4056 bombout((ssh
,"Server's host key did not match the signature supplied"));
4061 * Authenticate remote host: verify host key. (We've already
4062 * checked the signature of the exchange hash.)
4064 s
->keystr
= ssh
->hostkey
->fmtkey(s
->hkey
);
4065 s
->fingerprint
= ssh
->hostkey
->fingerprint(s
->hkey
);
4066 verify_ssh_host_key(ssh
->frontend
,
4067 ssh
->savedhost
, ssh
->savedport
, ssh
->hostkey
->keytype
,
4068 s
->keystr
, s
->fingerprint
);
4069 if (s
->first_kex
) { /* don't bother logging this in rekeys */
4070 logevent("Host key fingerprint is:");
4071 logevent(s
->fingerprint
);
4073 sfree(s
->fingerprint
);
4075 ssh
->hostkey
->freekey(s
->hkey
);
4078 * Send SSH2_MSG_NEWKEYS.
4080 ssh2_pkt_init(ssh
, SSH2_MSG_NEWKEYS
);
4084 * Expect SSH2_MSG_NEWKEYS from server.
4087 if (ssh
->pktin
.type
!= SSH2_MSG_NEWKEYS
) {
4088 bombout((ssh
,"expected new-keys packet from server"));
4093 * Create and initialise session keys.
4095 if (ssh
->cs_cipher_ctx
)
4096 ssh
->cscipher
->free_context(ssh
->cs_cipher_ctx
);
4097 ssh
->cscipher
= s
->cscipher_tobe
;
4098 ssh
->cs_cipher_ctx
= ssh
->cscipher
->make_context();
4100 if (ssh
->sc_cipher_ctx
)
4101 ssh
->sccipher
->free_context(ssh
->sc_cipher_ctx
);
4102 ssh
->sccipher
= s
->sccipher_tobe
;
4103 ssh
->sc_cipher_ctx
= ssh
->sccipher
->make_context();
4105 if (ssh
->cs_mac_ctx
)
4106 ssh
->csmac
->free_context(ssh
->cs_mac_ctx
);
4107 ssh
->csmac
= s
->csmac_tobe
;
4108 ssh
->cs_mac_ctx
= ssh
->csmac
->make_context();
4110 if (ssh
->sc_mac_ctx
)
4111 ssh
->scmac
->free_context(ssh
->sc_mac_ctx
);
4112 ssh
->scmac
= s
->scmac_tobe
;
4113 ssh
->sc_mac_ctx
= ssh
->scmac
->make_context();
4115 if (ssh
->cs_comp_ctx
)
4116 ssh
->cscomp
->compress_cleanup(ssh
->cs_comp_ctx
);
4117 ssh
->cscomp
= s
->cscomp_tobe
;
4118 ssh
->cs_comp_ctx
= ssh
->cscomp
->compress_init();
4120 if (ssh
->sc_comp_ctx
)
4121 ssh
->sccomp
->decompress_cleanup(ssh
->sc_comp_ctx
);
4122 ssh
->sccomp
= s
->sccomp_tobe
;
4123 ssh
->sc_comp_ctx
= ssh
->sccomp
->decompress_init();
4126 * Set IVs after keys. Here we use the exchange hash from the
4127 * _first_ key exchange.
4130 unsigned char keyspace
[40];
4132 memcpy(ssh
->v2_session_id
, s
->exchange_hash
,
4133 sizeof(s
->exchange_hash
));
4134 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'C',keyspace
);
4135 ssh
->cscipher
->setkey(ssh
->cs_cipher_ctx
, keyspace
);
4136 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'D',keyspace
);
4137 ssh
->sccipher
->setkey(ssh
->sc_cipher_ctx
, keyspace
);
4138 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'A',keyspace
);
4139 ssh
->cscipher
->setiv(ssh
->cs_cipher_ctx
, keyspace
);
4140 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'B',keyspace
);
4141 ssh
->sccipher
->setiv(ssh
->sc_cipher_ctx
, keyspace
);
4142 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'E',keyspace
);
4143 ssh
->csmac
->setkey(ssh
->cs_mac_ctx
, keyspace
);
4144 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'F',keyspace
);
4145 ssh
->scmac
->setkey(ssh
->sc_mac_ctx
, keyspace
);
4147 logeventf(ssh
, "Initialised %.200s client->server encryption",
4148 ssh
->cscipher
->text_name
);
4149 logeventf(ssh
, "Initialised %.200s server->client encryption",
4150 ssh
->sccipher
->text_name
);
4151 if (ssh
->cscomp
->text_name
)
4152 logeventf(ssh
, "Initialised %s compression",
4153 ssh
->cscomp
->text_name
);
4154 if (ssh
->sccomp
->text_name
)
4155 logeventf(ssh
, "Initialised %s decompression",
4156 ssh
->sccomp
->text_name
);
4159 * If this is the first key exchange phase, we must pass the
4160 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4161 * wants to see it but because it will need time to initialise
4162 * itself before it sees an actual packet. In subsequent key
4163 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4164 * it would only confuse the layer above.
4166 if (!s
->first_kex
) {
4172 * Now we're encrypting. Begin returning 1 to the protocol main
4173 * function so that other things can run on top of the
4174 * transport. If we ever see a KEXINIT, we must go back to the
4177 while (!(ispkt
&& ssh
->pktin
.type
== SSH2_MSG_KEXINIT
)) {
4180 logevent("Server initiated key re-exchange");
4181 goto begin_key_exchange
;
4187 * Add data to an SSH2 channel output buffer.
4189 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
4192 bufchain_add(&c
->v
.v2
.outbuffer
, buf
, len
);
4196 * Attempt to send data on an SSH2 channel.
4198 static int ssh2_try_send(struct ssh_channel
*c
)
4202 while (c
->v
.v2
.remwindow
> 0 && bufchain_size(&c
->v
.v2
.outbuffer
) > 0) {
4205 bufchain_prefix(&c
->v
.v2
.outbuffer
, &data
, &len
);
4206 if ((unsigned)len
> c
->v
.v2
.remwindow
)
4207 len
= c
->v
.v2
.remwindow
;
4208 if ((unsigned)len
> c
->v
.v2
.remmaxpkt
)
4209 len
= c
->v
.v2
.remmaxpkt
;
4210 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_DATA
);
4211 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
4212 ssh2_pkt_addstring_start(ssh
);
4213 ssh2_pkt_addstring_data(ssh
, data
, len
);
4215 bufchain_consume(&c
->v
.v2
.outbuffer
, len
);
4216 c
->v
.v2
.remwindow
-= len
;
4220 * After having sent as much data as we can, return the amount
4223 return bufchain_size(&c
->v
.v2
.outbuffer
);
4227 * Potentially enlarge the window on an SSH2 channel.
4229 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
)
4234 * Never send WINDOW_ADJUST for a channel that the remote side
4235 * already thinks it's closed; there's no point, since it won't
4236 * be sending any more data anyway.
4241 if (newwin
> c
->v
.v2
.locwindow
) {
4242 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4243 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
4244 ssh2_pkt_adduint32(ssh
, newwin
- c
->v
.v2
.locwindow
);
4246 c
->v
.v2
.locwindow
= newwin
;
4251 * Handle the SSH2 userauth and connection layers.
4253 static void do_ssh2_authconn(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
4255 struct do_ssh2_authconn_state
{
4257 AUTH_INVALID
, AUTH_PUBLICKEY_AGENT
, AUTH_PUBLICKEY_FILE
,
4259 AUTH_KEYBOARD_INTERACTIVE
4263 AUTH_TYPE_PUBLICKEY
,
4264 AUTH_TYPE_PUBLICKEY_OFFER_LOUD
,
4265 AUTH_TYPE_PUBLICKEY_OFFER_QUIET
,
4267 AUTH_TYPE_KEYBOARD_INTERACTIVE
,
4268 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4270 int gotit
, need_pw
, can_pubkey
, can_passwd
, can_keyb_inter
;
4271 int tried_pubkey_config
, tried_agent
, tried_keyb_inter
;
4272 int kbd_inter_running
;
4274 int num_prompts
, curr_prompt
, echo
;
4279 void *publickey_blob
;
4280 int publickey_bloblen
;
4281 unsigned char request
[5], *response
, *p
;
4285 char *pkblob
, *alg
, *commentp
;
4286 int pklen
, alglen
, commentlen
;
4287 int siglen
, retlen
, len
;
4288 char *q
, *agentreq
, *ret
;
4291 crState(do_ssh2_authconn_state
);
4293 crBegin(ssh
->do_ssh2_authconn_crstate
);
4296 * Request userauth protocol, and await a response to it.
4298 ssh2_pkt_init(ssh
, SSH2_MSG_SERVICE_REQUEST
);
4299 ssh2_pkt_addstring(ssh
, "ssh-userauth");
4301 crWaitUntilV(ispkt
);
4302 if (ssh
->pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
) {
4303 bombout((ssh
,"Server refused user authentication protocol"));
4308 * We repeat this whole loop, including the username prompt,
4309 * until we manage a successful authentication. If the user
4310 * types the wrong _password_, they can be sent back to the
4311 * beginning to try another username, if this is configured on.
4312 * (If they specify a username in the config, they are never
4313 * asked, even if they do give a wrong password.)
4315 * I think this best serves the needs of
4317 * - the people who have no configuration, no keys, and just
4318 * want to try repeated (username,password) pairs until they
4319 * type both correctly
4321 * - people who have keys and configuration but occasionally
4322 * need to fall back to passwords
4324 * - people with a key held in Pageant, who might not have
4325 * logged in to a particular machine before; so they want to
4326 * type a username, and then _either_ their key will be
4327 * accepted, _or_ they will type a password. If they mistype
4328 * the username they will want to be able to get back and
4331 s
->username
[0] = '\0';
4332 s
->got_username
= FALSE
;
4337 if (s
->got_username
&& !cfg
.change_username
) {
4339 * We got a username last time round this loop, and
4340 * with change_username turned off we don't try to get
4343 } else if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
4344 if (ssh_get_line
&& !ssh_getline_pw_only
) {
4345 if (!ssh_get_line("login as: ",
4346 s
->username
, sizeof(s
->username
), FALSE
)) {
4348 * get_line failed to get a username.
4351 logevent("No username provided. Abandoning session.");
4352 ssh
->state
= SSH_STATE_CLOSED
;
4356 int ret
; /* need not be saved across crReturn */
4357 c_write_str(ssh
, "login as: ");
4359 setup_userpass_input(ssh
, s
->username
, sizeof(s
->username
), 1);
4361 crWaitUntilV(!ispkt
);
4362 ret
= process_userpass_input(ssh
, in
, inlen
);
4366 c_write_str(ssh
, "\r\n");
4368 s
->username
[strcspn(s
->username
, "\n\r")] = '\0';
4371 strncpy(s
->username
, cfg
.username
, sizeof(s
->username
));
4372 s
->username
[sizeof(s
->username
)-1] = '\0';
4373 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
4374 stuff
= dupprintf("Using username \"%s\".\r\n", s
->username
);
4375 c_write_str(ssh
, stuff
);
4379 s
->got_username
= TRUE
;
4382 * Send an authentication request using method "none": (a)
4383 * just in case it succeeds, and (b) so that we know what
4384 * authentication methods we can usefully try next.
4386 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4388 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4389 ssh2_pkt_addstring(ssh
, s
->username
);
4390 ssh2_pkt_addstring(ssh
, "ssh-connection");/* service requested */
4391 ssh2_pkt_addstring(ssh
, "none"); /* method */
4393 s
->type
= AUTH_TYPE_NONE
;
4395 s
->we_are_in
= FALSE
;
4397 s
->tried_pubkey_config
= FALSE
;
4398 s
->tried_agent
= FALSE
;
4399 s
->tried_keyb_inter
= FALSE
;
4400 s
->kbd_inter_running
= FALSE
;
4401 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
4404 logeventf(ssh
, "Reading private key file \"%.150s\"", cfg
.keyfile
);
4405 keytype
= key_type(cfg
.keyfile
);
4406 if (keytype
== SSH_KEYTYPE_SSH2
) {
4408 ssh2_userkey_loadpub(cfg
.keyfile
, NULL
,
4409 &s
->publickey_bloblen
);
4412 logeventf(ssh
, "Unable to use this key file (%s)",
4413 key_type_to_str(keytype
));
4414 msgbuf
= dupprintf("Unable to use key file \"%.150s\""
4415 " (%s)\r\n", cfg
.keyfile
,
4416 key_type_to_str(keytype
));
4417 c_write_str(ssh
, msgbuf
);
4419 s
->publickey_blob
= NULL
;
4422 s
->publickey_blob
= NULL
;
4426 * Wait for the result of the last authentication request.
4429 crWaitUntilV(ispkt
);
4430 while (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_BANNER
) {
4434 * Don't show the banner if we're operating in
4435 * non-verbose non-interactive mode. (It's probably
4436 * a script, which means nobody will read the
4437 * banner _anyway_, and moreover the printing of
4438 * the banner will screw up processing on the
4439 * output of (say) plink.)
4441 if (flags
& (FLAG_VERBOSE
| FLAG_INTERACTIVE
)) {
4442 ssh2_pkt_getstring(ssh
, &banner
, &size
);
4444 c_write_untrusted(ssh
, banner
, size
);
4446 crWaitUntilV(ispkt
);
4448 if (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_SUCCESS
) {
4449 logevent("Access granted");
4450 s
->we_are_in
= TRUE
;
4454 if (s
->kbd_inter_running
&&
4455 ssh
->pktin
.type
== SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4457 * This is either a further set-of-prompts packet
4458 * in keyboard-interactive authentication, or it's
4459 * the same one and we came back here with `gotit'
4460 * set. In the former case, we must reset the
4461 * curr_prompt variable.
4465 } else if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_FAILURE
) {
4466 bombout((ssh
,"Strange packet received during authentication: type %d",
4474 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4475 * we can look at the string in it and know what we can
4476 * helpfully try next.
4478 if (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
) {
4481 ssh2_pkt_getstring(ssh
, &methods
, &methlen
);
4482 s
->kbd_inter_running
= FALSE
;
4483 if (!ssh2_pkt_getbool(ssh
)) {
4485 * We have received an unequivocal Access
4486 * Denied. This can translate to a variety of
4489 * - if we'd just tried "none" authentication,
4490 * it's not worth printing anything at all
4492 * - if we'd just tried a public key _offer_,
4493 * the message should be "Server refused our
4494 * key" (or no message at all if the key
4495 * came from Pageant)
4497 * - if we'd just tried anything else, the
4498 * message really should be "Access denied".
4500 * Additionally, if we'd just tried password
4501 * authentication, we should break out of this
4502 * whole loop so as to go back to the username
4505 if (s
->type
== AUTH_TYPE_NONE
) {
4507 } else if (s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
||
4508 s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_QUIET
) {
4509 if (s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
)
4510 c_write_str(ssh
, "Server refused our key\r\n");
4511 logevent("Server refused public key");
4512 } else if (s
->type
==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
) {
4513 /* server declined keyboard-interactive; ignore */
4515 c_write_str(ssh
, "Access denied\r\n");
4516 logevent("Access denied");
4517 if (s
->type
== AUTH_TYPE_PASSWORD
) {
4518 s
->we_are_in
= FALSE
;
4523 c_write_str(ssh
, "Further authentication required\r\n");
4524 logevent("Further authentication required");
4528 in_commasep_string("publickey", methods
, methlen
);
4530 in_commasep_string("password", methods
, methlen
);
4531 s
->can_keyb_inter
= cfg
.try_ki_auth
&&
4532 in_commasep_string("keyboard-interactive", methods
, methlen
);
4536 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4539 * Most password/passphrase prompts will be
4540 * non-echoing, so we set this to 0 by default.
4541 * Exception is that some keyboard-interactive prompts
4542 * can be echoing, in which case we'll set this to 1.
4546 if (!s
->method
&& s
->can_pubkey
&&
4547 agent_exists() && !s
->tried_agent
) {
4549 * Attempt public-key authentication using Pageant.
4554 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4555 ssh
->pkt_ctx
|= SSH2_PKTCTX_PUBLICKEY
;
4557 s
->tried_agent
= TRUE
;
4559 logevent("Pageant is running. Requesting keys.");
4561 /* Request the keys held by the agent. */
4562 PUT_32BIT(s
->request
, 1);
4563 s
->request
[4] = SSH2_AGENTC_REQUEST_IDENTITIES
;
4564 agent_query(s
->request
, 5, &r
, &s
->responselen
);
4565 s
->response
= (unsigned char *) r
;
4566 if (s
->response
&& s
->responselen
>= 5 &&
4567 s
->response
[4] == SSH2_AGENT_IDENTITIES_ANSWER
) {
4568 s
->p
= s
->response
+ 5;
4569 s
->nkeys
= GET_32BIT(s
->p
);
4573 sprintf(buf
, "Pageant has %d SSH2 keys", s
->nkeys
);
4576 for (s
->keyi
= 0; s
->keyi
< s
->nkeys
; s
->keyi
++) {
4581 sprintf(buf
, "Trying Pageant key #%d", s
->keyi
);
4584 s
->pklen
= GET_32BIT(s
->p
);
4586 if (s
->publickey_blob
&&
4587 s
->pklen
== s
->publickey_bloblen
&&
4588 !memcmp(s
->p
, s
->publickey_blob
,
4589 s
->publickey_bloblen
)) {
4590 logevent("This key matches configured key file");
4591 s
->tried_pubkey_config
= 1;
4595 s
->alglen
= GET_32BIT(s
->pkblob
);
4596 s
->alg
= s
->pkblob
+ 4;
4597 s
->commentlen
= GET_32BIT(s
->p
);
4600 s
->p
+= s
->commentlen
;
4601 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4602 ssh2_pkt_addstring(ssh
, s
->username
);
4603 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4604 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4605 ssh2_pkt_addbool(ssh
, FALSE
); /* no signature included */
4606 ssh2_pkt_addstring_start(ssh
);
4607 ssh2_pkt_addstring_data(ssh
, s
->alg
, s
->alglen
);
4608 ssh2_pkt_addstring_start(ssh
);
4609 ssh2_pkt_addstring_data(ssh
, s
->pkblob
, s
->pklen
);
4612 crWaitUntilV(ispkt
);
4613 if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4614 logevent("Key refused");
4618 if (flags
& FLAG_VERBOSE
) {
4619 c_write_str(ssh
, "Authenticating with "
4621 c_write(ssh
, s
->commentp
, s
->commentlen
);
4622 c_write_str(ssh
, "\" from agent\r\n");
4626 * Server is willing to accept the key.
4627 * Construct a SIGN_REQUEST.
4629 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4630 ssh2_pkt_addstring(ssh
, s
->username
);
4631 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4632 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4633 ssh2_pkt_addbool(ssh
, TRUE
);
4634 ssh2_pkt_addstring_start(ssh
);
4635 ssh2_pkt_addstring_data(ssh
, s
->alg
, s
->alglen
);
4636 ssh2_pkt_addstring_start(ssh
);
4637 ssh2_pkt_addstring_data(ssh
, s
->pkblob
, s
->pklen
);
4639 s
->siglen
= ssh
->pktout
.length
- 5 + 4 + 20;
4640 s
->len
= 1; /* message type */
4641 s
->len
+= 4 + s
->pklen
; /* key blob */
4642 s
->len
+= 4 + s
->siglen
; /* data to sign */
4643 s
->len
+= 4; /* flags */
4644 s
->agentreq
= smalloc(4 + s
->len
);
4645 PUT_32BIT(s
->agentreq
, s
->len
);
4646 s
->q
= s
->agentreq
+ 4;
4647 *s
->q
++ = SSH2_AGENTC_SIGN_REQUEST
;
4648 PUT_32BIT(s
->q
, s
->pklen
);
4650 memcpy(s
->q
, s
->pkblob
, s
->pklen
);
4652 PUT_32BIT(s
->q
, s
->siglen
);
4654 /* Now the data to be signed... */
4655 PUT_32BIT(s
->q
, 20);
4657 memcpy(s
->q
, ssh
->v2_session_id
, 20);
4659 memcpy(s
->q
, ssh
->pktout
.data
+ 5,
4660 ssh
->pktout
.length
- 5);
4661 s
->q
+= ssh
->pktout
.length
- 5;
4662 /* And finally the (zero) flags word. */
4664 agent_query(s
->agentreq
, s
->len
+ 4, &vret
, &s
->retlen
);
4668 if (s
->ret
[4] == SSH2_AGENT_SIGN_RESPONSE
) {
4669 logevent("Sending Pageant's response");
4670 ssh2_add_sigblob(ssh
, s
->pkblob
, s
->pklen
,
4672 GET_32BIT(s
->ret
+ 5));
4678 ("Pageant failed to answer challenge");
4688 if (!s
->method
&& s
->can_pubkey
&& s
->publickey_blob
4689 && !s
->tried_pubkey_config
) {
4690 unsigned char *pub_blob
;
4691 char *algorithm
, *comment
;
4694 s
->tried_pubkey_config
= TRUE
;
4696 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4697 ssh
->pkt_ctx
|= SSH2_PKTCTX_PUBLICKEY
;
4700 * Try the public key supplied in the configuration.
4702 * First, offer the public blob to see if the server is
4703 * willing to accept it.
4705 pub_blob
= ssh2_userkey_loadpub(cfg
.keyfile
, &algorithm
,
4708 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4709 ssh2_pkt_addstring(ssh
, s
->username
);
4710 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4711 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4712 ssh2_pkt_addbool(ssh
, FALSE
); /* no signature included */
4713 ssh2_pkt_addstring(ssh
, algorithm
);
4714 ssh2_pkt_addstring_start(ssh
);
4715 ssh2_pkt_addstring_data(ssh
, pub_blob
, pub_blob_len
);
4717 logevent("Offered public key"); /* FIXME */
4719 crWaitUntilV(ispkt
);
4720 if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4722 s
->type
= AUTH_TYPE_PUBLICKEY_OFFER_LOUD
;
4723 continue; /* key refused; give up on it */
4726 logevent("Offer of public key accepted");
4728 * Actually attempt a serious authentication using
4731 if (ssh2_userkey_encrypted(cfg
.keyfile
, &comment
)) {
4732 sprintf(s
->pwprompt
,
4733 "Passphrase for key \"%.100s\": ",
4739 c_write_str(ssh
, "Authenticating with public key \"");
4740 c_write_str(ssh
, comment
);
4741 c_write_str(ssh
, "\"\r\n");
4742 s
->method
= AUTH_PUBLICKEY_FILE
;
4746 if (!s
->method
&& s
->can_keyb_inter
&& !s
->tried_keyb_inter
) {
4747 s
->method
= AUTH_KEYBOARD_INTERACTIVE
;
4748 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4749 s
->tried_keyb_inter
= TRUE
;
4751 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4752 ssh
->pkt_ctx
|= SSH2_PKTCTX_KBDINTER
;
4754 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4755 ssh2_pkt_addstring(ssh
, s
->username
);
4756 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4757 ssh2_pkt_addstring(ssh
, "keyboard-interactive"); /* method */
4758 ssh2_pkt_addstring(ssh
, ""); /* lang */
4759 ssh2_pkt_addstring(ssh
, "");
4762 crWaitUntilV(ispkt
);
4763 if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4764 if (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
)
4766 logevent("Keyboard-interactive authentication refused");
4767 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
;
4771 s
->kbd_inter_running
= TRUE
;
4775 if (s
->kbd_inter_running
) {
4776 s
->method
= AUTH_KEYBOARD_INTERACTIVE
;
4777 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4778 s
->tried_keyb_inter
= TRUE
;
4780 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4781 ssh
->pkt_ctx
|= SSH2_PKTCTX_KBDINTER
;
4783 if (s
->curr_prompt
== 0) {
4785 * We've got a fresh USERAUTH_INFO_REQUEST.
4786 * Display header data, and start going through
4789 char *name
, *inst
, *lang
;
4790 int name_len
, inst_len
, lang_len
;
4792 ssh2_pkt_getstring(ssh
, &name
, &name_len
);
4793 ssh2_pkt_getstring(ssh
, &inst
, &inst_len
);
4794 ssh2_pkt_getstring(ssh
, &lang
, &lang_len
);
4796 c_write_untrusted(ssh
, name
, name_len
);
4797 c_write_str(ssh
, "\r\n");
4800 c_write_untrusted(ssh
, inst
, inst_len
);
4801 c_write_str(ssh
, "\r\n");
4803 s
->num_prompts
= ssh2_pkt_getuint32(ssh
);
4807 * If there are prompts remaining in the packet,
4808 * display one and get a response.
4810 if (s
->curr_prompt
< s
->num_prompts
) {
4814 ssh2_pkt_getstring(ssh
, &prompt
, &prompt_len
);
4815 if (prompt_len
> 0) {
4816 strncpy(s
->pwprompt
, prompt
, sizeof(s
->pwprompt
));
4817 s
->pwprompt
[prompt_len
< sizeof(s
->pwprompt
) ?
4818 prompt_len
: sizeof(s
->pwprompt
)-1] = '\0';
4821 "<server failed to send prompt>: ");
4823 s
->echo
= ssh2_pkt_getbool(ssh
);
4829 if (!s
->method
&& s
->can_passwd
) {
4830 s
->method
= AUTH_PASSWORD
;
4831 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4832 ssh
->pkt_ctx
|= SSH2_PKTCTX_PASSWORD
;
4833 sprintf(s
->pwprompt
, "%.90s@%.90s's password: ", s
->username
,
4840 if (!ssh_get_line(s
->pwprompt
, s
->password
,
4841 sizeof(s
->password
), TRUE
)) {
4843 * get_line failed to get a password (for
4844 * example because one was supplied on the
4845 * command line which has already failed to
4848 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
4849 ssh2_pkt_adduint32(ssh
,SSH2_DISCONNECT_BY_APPLICATION
);
4850 ssh2_pkt_addstring(ssh
, "No more passwords available"
4852 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
4854 logevent("Unable to authenticate");
4855 connection_fatal(ssh
->frontend
,
4856 "Unable to authenticate");
4857 ssh
->state
= SSH_STATE_CLOSED
;
4861 int ret
; /* need not be saved across crReturn */
4862 c_write_untrusted(ssh
, s
->pwprompt
, strlen(s
->pwprompt
));
4865 setup_userpass_input(ssh
, s
->password
,
4866 sizeof(s
->password
), s
->echo
);
4868 crWaitUntilV(!ispkt
);
4869 ret
= process_userpass_input(ssh
, in
, inlen
);
4873 c_write_str(ssh
, "\r\n");
4877 if (s
->method
== AUTH_PUBLICKEY_FILE
) {
4879 * We have our passphrase. Now try the actual authentication.
4881 struct ssh2_userkey
*key
;
4883 key
= ssh2_load_userkey(cfg
.keyfile
, s
->password
);
4884 if (key
== SSH2_WRONG_PASSPHRASE
|| key
== NULL
) {
4885 if (key
== SSH2_WRONG_PASSPHRASE
) {
4886 c_write_str(ssh
, "Wrong passphrase\r\n");
4887 s
->tried_pubkey_config
= FALSE
;
4889 c_write_str(ssh
, "Unable to load private key\r\n");
4890 s
->tried_pubkey_config
= TRUE
;
4892 /* Send a spurious AUTH_NONE to return to the top. */
4893 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4894 ssh2_pkt_addstring(ssh
, s
->username
);
4895 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4896 ssh2_pkt_addstring(ssh
, "none"); /* method */
4898 s
->type
= AUTH_TYPE_NONE
;
4900 unsigned char *pkblob
, *sigblob
, *sigdata
;
4901 int pkblob_len
, sigblob_len
, sigdata_len
;
4904 * We have loaded the private key and the server
4905 * has announced that it's willing to accept it.
4906 * Hallelujah. Generate a signature and send it.
4908 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4909 ssh2_pkt_addstring(ssh
, s
->username
);
4910 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4911 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4912 ssh2_pkt_addbool(ssh
, TRUE
);
4913 ssh2_pkt_addstring(ssh
, key
->alg
->name
);
4914 pkblob
= key
->alg
->public_blob(key
->data
, &pkblob_len
);
4915 ssh2_pkt_addstring_start(ssh
);
4916 ssh2_pkt_addstring_data(ssh
, pkblob
, pkblob_len
);
4919 * The data to be signed is:
4923 * followed by everything so far placed in the
4926 sigdata_len
= ssh
->pktout
.length
- 5 + 4 + 20;
4927 sigdata
= smalloc(sigdata_len
);
4928 PUT_32BIT(sigdata
, 20);
4929 memcpy(sigdata
+ 4, ssh
->v2_session_id
, 20);
4930 memcpy(sigdata
+ 24, ssh
->pktout
.data
+ 5,
4931 ssh
->pktout
.length
- 5);
4932 sigblob
= key
->alg
->sign(key
->data
, sigdata
,
4933 sigdata_len
, &sigblob_len
);
4934 ssh2_add_sigblob(ssh
, pkblob
, pkblob_len
,
4935 sigblob
, sigblob_len
);
4941 s
->type
= AUTH_TYPE_PUBLICKEY
;
4943 } else if (s
->method
== AUTH_PASSWORD
) {
4945 * We send the password packet lumped tightly together with
4946 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4947 * string long enough to make the total length of the two
4948 * packets constant. This should ensure that a passive
4949 * listener doing traffic analyis can't work out the length
4952 * For this to work, we need an assumption about the
4953 * maximum length of the password packet. I think 256 is
4954 * pretty conservative. Anyone using a password longer than
4955 * that probably doesn't have much to worry about from
4956 * people who find out how long their password is!
4958 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4959 ssh2_pkt_addstring(ssh
, s
->username
);
4960 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4961 ssh2_pkt_addstring(ssh
, "password");
4962 ssh2_pkt_addbool(ssh
, FALSE
);
4963 ssh2_pkt_addstring(ssh
, s
->password
);
4964 ssh2_pkt_defer(ssh
);
4966 * We'll include a string that's an exact multiple of the
4967 * cipher block size. If the cipher is NULL for some
4968 * reason, we don't do this trick at all because we gain
4971 if (ssh
->cscipher
) {
4974 stringlen
= (256 - ssh
->deferred_len
);
4975 stringlen
+= ssh
->cscipher
->blksize
- 1;
4976 stringlen
-= (stringlen
% ssh
->cscipher
->blksize
);
4979 * Temporarily disable actual compression,
4980 * so we can guarantee to get this string
4981 * exactly the length we want it. The
4982 * compression-disabling routine should
4983 * return an integer indicating how many
4984 * bytes we should adjust our string length
4988 ssh
->cscomp
->disable_compression(ssh
->cs_comp_ctx
);
4990 ssh2_pkt_init(ssh
, SSH2_MSG_IGNORE
);
4991 ssh2_pkt_addstring_start(ssh
);
4992 for (i
= 0; i
< stringlen
; i
++) {
4993 char c
= (char) random_byte();
4994 ssh2_pkt_addstring_data(ssh
, &c
, 1);
4996 ssh2_pkt_defer(ssh
);
4998 ssh_pkt_defersend(ssh
);
4999 logevent("Sent password");
5000 s
->type
= AUTH_TYPE_PASSWORD
;
5001 } else if (s
->method
== AUTH_KEYBOARD_INTERACTIVE
) {
5002 if (s
->curr_prompt
== 0) {
5003 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_INFO_RESPONSE
);
5004 ssh2_pkt_adduint32(ssh
, s
->num_prompts
);
5006 if (s
->need_pw
) { /* only add pw if we just got one! */
5007 ssh2_pkt_addstring(ssh
, s
->password
);
5008 memset(s
->password
, 0, sizeof(s
->password
));
5011 if (s
->curr_prompt
>= s
->num_prompts
) {
5015 * If there are prompts remaining, we set
5016 * `gotit' so that we won't attempt to get
5017 * another packet. Then we go back round the
5018 * loop and will end up retrieving another
5019 * prompt out of the existing packet. Funky or
5024 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
5026 c_write_str(ssh
, "No supported authentication methods"
5027 " left to try!\r\n");
5028 logevent("No supported authentications offered."
5030 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
5031 ssh2_pkt_adduint32(ssh
, SSH2_DISCONNECT_BY_APPLICATION
);
5032 ssh2_pkt_addstring(ssh
, "No supported authentication"
5033 " methods available");
5034 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5036 ssh
->state
= SSH_STATE_CLOSED
;
5040 } while (!s
->we_are_in
);
5043 * Now we're authenticated for the connection protocol. The
5044 * connection protocol will automatically have started at this
5045 * point; there's no need to send SERVICE_REQUEST.
5049 * So now create a channel with a session in it.
5051 ssh
->channels
= newtree234(ssh_channelcmp
);
5052 ssh
->mainchan
= smalloc(sizeof(struct ssh_channel
));
5053 ssh
->mainchan
->ssh
= ssh
;
5054 ssh
->mainchan
->localid
= alloc_channel_id(ssh
);
5055 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN
);
5056 ssh2_pkt_addstring(ssh
, "session");
5057 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->localid
);
5058 ssh
->mainchan
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5059 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->v
.v2
.locwindow
);/* our window size */
5060 ssh2_pkt_adduint32(ssh
, 0x4000UL
); /* our max pkt size */
5062 crWaitUntilV(ispkt
);
5063 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
5064 bombout((ssh
,"Server refused to open a session"));
5066 /* FIXME: error data comes back in FAILURE packet */
5068 if (ssh2_pkt_getuint32(ssh
) != ssh
->mainchan
->localid
) {
5069 bombout((ssh
,"Server's channel confirmation cited wrong channel"));
5072 ssh
->mainchan
->remoteid
= ssh2_pkt_getuint32(ssh
);
5073 ssh
->mainchan
->type
= CHAN_MAINSESSION
;
5074 ssh
->mainchan
->closes
= 0;
5075 ssh
->mainchan
->v
.v2
.remwindow
= ssh2_pkt_getuint32(ssh
);
5076 ssh
->mainchan
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32(ssh
);
5077 bufchain_init(&ssh
->mainchan
->v
.v2
.outbuffer
);
5078 add234(ssh
->channels
, ssh
->mainchan
);
5079 logevent("Opened channel for session");
5082 * Potentially enable X11 forwarding.
5084 if (cfg
.x11_forward
) {
5085 char proto
[20], data
[64];
5086 logevent("Requesting X11 forwarding");
5087 ssh
->x11auth
= x11_invent_auth(proto
, sizeof(proto
),
5088 data
, sizeof(data
));
5089 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5090 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
5091 ssh2_pkt_addstring(ssh
, "x11-req");
5092 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5093 ssh2_pkt_addbool(ssh
, 0); /* many connections */
5094 ssh2_pkt_addstring(ssh
, proto
);
5095 ssh2_pkt_addstring(ssh
, data
);
5096 ssh2_pkt_adduint32(ssh
, 0); /* screen number */
5100 crWaitUntilV(ispkt
);
5101 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5102 unsigned i
= ssh2_pkt_getuint32(ssh
);
5103 struct ssh_channel
*c
;
5104 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5106 continue; /* nonexistent channel */
5107 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5109 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5111 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5112 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5113 bombout((ssh
,"Unexpected response to X11 forwarding request:"
5114 " packet type %d", ssh
->pktin
.type
));
5117 logevent("X11 forwarding refused");
5119 logevent("X11 forwarding enabled");
5120 ssh
->X11_fwd_enabled
= TRUE
;
5125 * Enable port forwardings.
5130 int sport
,dport
,sserv
,dserv
;
5131 char sports
[256], dports
[256], saddr
[256], host
[256];
5133 ssh
->rportfwds
= newtree234(ssh_rportcmp_ssh2
);
5134 /* Add port forwardings. */
5135 ssh
->portfwd_strptr
= cfg
.portfwd
;
5136 while (*ssh
->portfwd_strptr
) {
5137 type
= *ssh
->portfwd_strptr
++;
5140 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= '\t') {
5141 if (*ssh
->portfwd_strptr
== ':') {
5143 * We've seen a colon in the middle of the
5144 * source port number. This means that
5145 * everything we've seen until now is the
5146 * source _address_, so we'll move it into
5147 * saddr and start sports from the beginning
5150 ssh
->portfwd_strptr
++;
5152 strcpy(saddr
, sports
);
5155 if (n
< 255) sports
[n
++] = *ssh
->portfwd_strptr
++;
5158 if (*ssh
->portfwd_strptr
== '\t')
5159 ssh
->portfwd_strptr
++;
5161 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= ':') {
5162 if (n
< 255) host
[n
++] = *ssh
->portfwd_strptr
++;
5165 if (*ssh
->portfwd_strptr
== ':')
5166 ssh
->portfwd_strptr
++;
5168 while (*ssh
->portfwd_strptr
) {
5169 if (n
< 255) dports
[n
++] = *ssh
->portfwd_strptr
++;
5172 ssh
->portfwd_strptr
++;
5173 dport
= atoi(dports
);
5177 dport
= net_service_lookup(dports
);
5179 logeventf(ssh
, "Service lookup failed for destination"
5180 " port \"%s\"", dports
);
5183 sport
= atoi(sports
);
5187 sport
= net_service_lookup(sports
);
5189 logeventf(ssh
, "Service lookup failed for source"
5190 " port \"%s\"", sports
);
5193 if (sport
&& dport
) {
5195 pfd_addforward(host
, dport
, *saddr ? saddr
: NULL
,
5197 logeventf(ssh
, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5198 " forwarding to %s:%.*s%.*s%d%.*s",
5199 (int)(*saddr?
strlen(saddr
):0), *saddr?saddr
:NULL
,
5200 (int)(*saddr?
1:0), ":",
5201 (int)(sserv ?
strlen(sports
) : 0), sports
,
5202 sserv
, "(", sport
, sserv
, ")",
5204 (int)(dserv ?
strlen(dports
) : 0), dports
,
5205 dserv
, "(", dport
, dserv
, ")");
5207 struct ssh_rportfwd
*pf
;
5208 pf
= smalloc(sizeof(*pf
));
5209 strcpy(pf
->dhost
, host
);
5212 if (add234(ssh
->rportfwds
, pf
) != pf
) {
5213 logeventf(ssh
, "Duplicate remote port forwarding"
5214 " to %s:%d", host
, dport
);
5217 logeventf(ssh
, "Requesting remote port "
5218 "%.*s%.*s%.*s%.*s%d%.*s"
5219 " forward to %s:%.*s%.*s%d%.*s",
5220 (int)(*saddr?
strlen(saddr
):0),
5222 (int)(*saddr?
1:0), ":",
5223 (int)(sserv ?
strlen(sports
) : 0), sports
,
5224 sserv
, "(", sport
, sserv
, ")",
5226 (int)(dserv ?
strlen(dports
) : 0), dports
,
5227 dserv
, "(", dport
, dserv
, ")");
5228 ssh2_pkt_init(ssh
, SSH2_MSG_GLOBAL_REQUEST
);
5229 ssh2_pkt_addstring(ssh
, "tcpip-forward");
5230 ssh2_pkt_addbool(ssh
, 1);/* want reply */
5232 ssh2_pkt_addstring(ssh
, saddr
);
5233 if (cfg
.rport_acceptall
)
5234 ssh2_pkt_addstring(ssh
, "0.0.0.0");
5236 ssh2_pkt_addstring(ssh
, "127.0.0.1");
5237 ssh2_pkt_adduint32(ssh
, sport
);
5241 crWaitUntilV(ispkt
);
5242 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5243 unsigned i
= ssh2_pkt_getuint32(ssh
);
5244 struct ssh_channel
*c
;
5245 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5247 continue;/* nonexistent channel */
5248 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5250 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5252 if (ssh
->pktin
.type
!= SSH2_MSG_REQUEST_SUCCESS
) {
5253 if (ssh
->pktin
.type
!= SSH2_MSG_REQUEST_FAILURE
) {
5254 bombout((ssh
,"Unexpected response to port "
5255 "forwarding request: packet type %d",
5259 logevent("Server refused this port forwarding");
5261 logevent("Remote port forwarding enabled");
5270 * Potentially enable agent forwarding.
5272 if (cfg
.agentfwd
&& agent_exists()) {
5273 logevent("Requesting OpenSSH-style agent forwarding");
5274 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5275 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
5276 ssh2_pkt_addstring(ssh
, "auth-agent-req@openssh.com");
5277 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5281 crWaitUntilV(ispkt
);
5282 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5283 unsigned i
= ssh2_pkt_getuint32(ssh
);
5284 struct ssh_channel
*c
;
5285 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5287 continue; /* nonexistent channel */
5288 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5290 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5292 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5293 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5294 bombout((ssh
,"Unexpected response to agent forwarding request:"
5295 " packet type %d", ssh
->pktin
.type
));
5298 logevent("Agent forwarding refused");
5300 logevent("Agent forwarding enabled");
5301 ssh
->agentfwd_enabled
= TRUE
;
5306 * Now allocate a pty for the session.
5309 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5310 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
); /* recipient channel */
5311 ssh2_pkt_addstring(ssh
, "pty-req");
5312 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5313 ssh2_pkt_addstring(ssh
, cfg
.termtype
);
5314 ssh2_pkt_adduint32(ssh
, ssh
->term_width
);
5315 ssh2_pkt_adduint32(ssh
, ssh
->term_height
);
5316 ssh2_pkt_adduint32(ssh
, 0); /* pixel width */
5317 ssh2_pkt_adduint32(ssh
, 0); /* pixel height */
5318 ssh2_pkt_addstring_start(ssh
);
5319 ssh2_pkt_addstring_data(ssh
, "\0", 1); /* TTY_OP_END, no special options */
5321 ssh
->state
= SSH_STATE_INTERMED
;
5324 crWaitUntilV(ispkt
);
5325 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5326 unsigned i
= ssh2_pkt_getuint32(ssh
);
5327 struct ssh_channel
*c
;
5328 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5330 continue; /* nonexistent channel */
5331 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5333 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5335 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5336 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5337 bombout((ssh
,"Unexpected response to pty request:"
5338 " packet type %d", ssh
->pktin
.type
));
5341 c_write_str(ssh
, "Server refused to allocate pty\r\n");
5342 ssh
->editing
= ssh
->echoing
= 1;
5344 logevent("Allocated pty");
5347 ssh
->editing
= ssh
->echoing
= 1;
5351 * Start a shell or a remote command. We may have to attempt
5352 * this twice if the config data has provided a second choice
5359 if (ssh
->fallback_cmd
) {
5360 subsys
= cfg
.ssh_subsys2
;
5361 cmd
= cfg
.remote_cmd_ptr2
;
5363 subsys
= cfg
.ssh_subsys
;
5364 cmd
= cfg
.remote_cmd_ptr
;
5367 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5368 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
); /* recipient channel */
5370 ssh2_pkt_addstring(ssh
, "subsystem");
5371 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5372 ssh2_pkt_addstring(ssh
, cmd
);
5374 ssh2_pkt_addstring(ssh
, "exec");
5375 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5376 ssh2_pkt_addstring(ssh
, cmd
);
5378 ssh2_pkt_addstring(ssh
, "shell");
5379 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5383 crWaitUntilV(ispkt
);
5384 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5385 unsigned i
= ssh2_pkt_getuint32(ssh
);
5386 struct ssh_channel
*c
;
5387 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5389 continue; /* nonexistent channel */
5390 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5392 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5393 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5394 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5395 bombout((ssh
,"Unexpected response to shell/command request:"
5396 " packet type %d", ssh
->pktin
.type
));
5400 * We failed to start the command. If this is the
5401 * fallback command, we really are finished; if it's
5402 * not, and if the fallback command exists, try falling
5403 * back to it before complaining.
5405 if (!ssh
->fallback_cmd
&& cfg
.remote_cmd_ptr2
!= NULL
) {
5406 logevent("Primary command failed; attempting fallback");
5407 ssh
->fallback_cmd
= TRUE
;
5410 bombout((ssh
,"Server refused to start a shell/command"));
5413 logevent("Started a shell/command");
5418 ssh
->state
= SSH_STATE_SESSION
;
5419 if (ssh
->size_needed
)
5420 ssh_size(ssh
, ssh
->term_width
, ssh
->term_height
);
5421 if (ssh
->eof_needed
)
5422 ssh_special(ssh
, TS_EOF
);
5428 ldisc_send(ssh
->ldisc
, NULL
, 0, 0);/* cause ldisc to notice changes */
5432 s
->try_send
= FALSE
;
5434 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
5435 ssh
->pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
5438 unsigned i
= ssh2_pkt_getuint32(ssh
);
5439 struct ssh_channel
*c
;
5440 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5442 continue; /* nonexistent channel */
5443 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
5444 ssh2_pkt_getuint32(ssh
) != SSH2_EXTENDED_DATA_STDERR
)
5445 continue; /* extended but not stderr */
5446 ssh2_pkt_getstring(ssh
, &data
, &length
);
5449 c
->v
.v2
.locwindow
-= length
;
5451 case CHAN_MAINSESSION
:
5453 from_backend(ssh
->frontend
, ssh
->pktin
.type
==
5454 SSH2_MSG_CHANNEL_EXTENDED_DATA
,
5458 bufsize
= x11_send(c
->u
.x11
.s
, data
, length
);
5461 bufsize
= pfd_send(c
->u
.pfd
.s
, data
, length
);
5464 while (length
> 0) {
5465 if (c
->u
.a
.lensofar
< 4) {
5466 int l
= min(4 - c
->u
.a
.lensofar
, length
);
5467 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
,
5471 c
->u
.a
.lensofar
+= l
;
5473 if (c
->u
.a
.lensofar
== 4) {
5475 4 + GET_32BIT(c
->u
.a
.msglen
);
5476 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
5477 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
5479 if (c
->u
.a
.lensofar
>= 4 && length
> 0) {
5481 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
5483 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
,
5487 c
->u
.a
.lensofar
+= l
;
5489 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
5490 void *reply
, *sentreply
;
5492 agent_query(c
->u
.a
.message
,
5493 c
->u
.a
.totallen
, &reply
,
5498 /* Fake SSH_AGENT_FAILURE. */
5499 sentreply
= "\0\0\0\1\5";
5502 ssh2_add_channel_data(c
, sentreply
, replylen
);
5506 sfree(c
->u
.a
.message
);
5507 c
->u
.a
.lensofar
= 0;
5514 * If we are not buffering too much data,
5515 * enlarge the window again at the remote side.
5517 if (bufsize
< OUR_V2_WINSIZE
)
5518 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
5520 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_EOF
) {
5521 unsigned i
= ssh2_pkt_getuint32(ssh
);
5522 struct ssh_channel
*c
;
5524 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5526 continue; /* nonexistent channel */
5528 if (c
->type
== CHAN_X11
) {
5530 * Remote EOF on an X11 channel means we should
5531 * wrap up and close the channel ourselves.
5533 x11_close(c
->u
.x11
.s
);
5535 } else if (c
->type
== CHAN_AGENT
) {
5537 } else if (c
->type
== CHAN_SOCKDATA
) {
5538 pfd_close(c
->u
.pfd
.s
);
5541 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_CLOSE
) {
5542 unsigned i
= ssh2_pkt_getuint32(ssh
);
5543 struct ssh_channel
*c
;
5545 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5546 if (!c
|| ((int)c
->remoteid
) == -1) {
5547 bombout((ssh
,"Received CHANNEL_CLOSE for %s channel %d\n",
5548 c ?
"half-open" : "nonexistent", i
));
5550 /* Do pre-close processing on the channel. */
5552 case CHAN_MAINSESSION
:
5553 break; /* nothing to see here, move along */
5555 if (c
->u
.x11
.s
!= NULL
)
5556 x11_close(c
->u
.x11
.s
);
5563 if (c
->u
.pfd
.s
!= NULL
)
5564 pfd_close(c
->u
.pfd
.s
);
5568 if (c
->closes
== 0) {
5569 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_CLOSE
);
5570 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5573 del234(ssh
->channels
, c
);
5574 bufchain_clear(&c
->v
.v2
.outbuffer
);
5578 * See if that was the last channel left open.
5580 if (count234(ssh
->channels
) == 0) {
5583 * We used to send SSH_MSG_DISCONNECT here,
5584 * because I'd believed that _every_ conforming
5585 * SSH2 connection had to end with a disconnect
5586 * being sent by at least one side; apparently
5587 * I was wrong and it's perfectly OK to
5588 * unceremoniously slam the connection shut
5589 * when you're done, and indeed OpenSSH feels
5590 * this is more polite than sending a
5591 * DISCONNECT. So now we don't.
5593 logevent("All channels closed. Disconnecting");
5594 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
5595 ssh2_pkt_adduint32(ssh
, SSH2_DISCONNECT_BY_APPLICATION
);
5596 ssh2_pkt_addstring(ssh
, "All open channels closed");
5597 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5600 ssh
->state
= SSH_STATE_CLOSED
;
5603 continue; /* remote sends close; ignore (FIXME) */
5604 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5605 unsigned i
= ssh2_pkt_getuint32(ssh
);
5606 struct ssh_channel
*c
;
5607 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5609 continue; /* nonexistent channel */
5610 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5612 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
5613 unsigned i
= ssh2_pkt_getuint32(ssh
);
5614 struct ssh_channel
*c
;
5615 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5617 continue; /* nonexistent channel */
5618 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
5619 continue; /* dunno why they're confirming this */
5620 c
->remoteid
= ssh2_pkt_getuint32(ssh
);
5621 c
->type
= CHAN_SOCKDATA
;
5622 c
->v
.v2
.remwindow
= ssh2_pkt_getuint32(ssh
);
5623 c
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32(ssh
);
5625 pfd_confirm(c
->u
.pfd
.s
);
5628 * We have a pending close on this channel,
5629 * which we decided on before the server acked
5630 * the channel open. So now we know the
5631 * remoteid, we can close it again.
5633 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_CLOSE
);
5634 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5637 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_OPEN_FAILURE
) {
5638 unsigned i
= ssh2_pkt_getuint32(ssh
);
5639 struct ssh_channel
*c
;
5640 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5642 continue; /* nonexistent channel */
5643 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
5644 continue; /* dunno why they're failing this */
5646 logevent("Forwarded connection refused by server");
5648 pfd_close(c
->u
.pfd
.s
);
5650 del234(ssh
->channels
, c
);
5652 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_REQUEST
) {
5655 int typelen
, want_reply
;
5656 struct ssh_channel
*c
;
5658 localid
= ssh2_pkt_getuint32(ssh
);
5659 ssh2_pkt_getstring(ssh
, &type
, &typelen
);
5660 want_reply
= ssh2_pkt_getbool(ssh
);
5663 * First, check that the channel exists. Otherwise,
5664 * we can instantly disconnect with a rude message.
5666 c
= find234(ssh
->channels
, &localid
, ssh_channelfind
);
5669 sprintf(buf
, "Received channel request for nonexistent"
5670 " channel %d", localid
);
5672 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
5673 ssh2_pkt_adduint32(ssh
, SSH2_DISCONNECT_BY_APPLICATION
);
5674 ssh2_pkt_addstring(ssh
, buf
);
5675 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5677 connection_fatal("%s", buf
);
5678 ssh
->state
= SSH_STATE_CLOSED
;
5683 * Having got the channel number, we now look at
5684 * the request type string to see if it's something
5687 if (typelen
== 11 && !memcmp(type
, "exit-status", 11) &&
5688 c
== ssh
->mainchan
) {
5689 /* We recognise "exit-status" on the primary channel. */
5691 ssh
->exitcode
= ssh2_pkt_getuint32(ssh
);
5692 sprintf(buf
, "Server sent command exit status %d",
5696 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_SUCCESS
);
5697 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5702 * This is a channel request we don't know
5703 * about, so we now either ignore the request
5704 * or respond with CHANNEL_FAILURE, depending
5708 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_FAILURE
);
5709 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5713 } else if (ssh
->pktin
.type
== SSH2_MSG_GLOBAL_REQUEST
) {
5715 int typelen
, want_reply
;
5717 ssh2_pkt_getstring(ssh
, &type
, &typelen
);
5718 want_reply
= ssh2_pkt_getbool(ssh
);
5721 * We currently don't support any global requests
5722 * at all, so we either ignore the request or
5723 * respond with REQUEST_FAILURE, depending on
5727 ssh2_pkt_init(ssh
, SSH2_MSG_REQUEST_FAILURE
);
5730 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_OPEN
) {
5734 struct ssh_channel
*c
;
5735 unsigned remid
, winsize
, pktsize
;
5736 ssh2_pkt_getstring(ssh
, &type
, &typelen
);
5737 c
= smalloc(sizeof(struct ssh_channel
));
5740 remid
= ssh2_pkt_getuint32(ssh
);
5741 winsize
= ssh2_pkt_getuint32(ssh
);
5742 pktsize
= ssh2_pkt_getuint32(ssh
);
5744 if (typelen
== 3 && !memcmp(type
, "x11", 3)) {
5745 if (!ssh
->X11_fwd_enabled
)
5746 error
= "X11 forwarding is not enabled";
5747 else if (x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
,
5748 ssh
->x11auth
) != NULL
) {
5749 error
= "Unable to open an X11 connection";
5753 } else if (typelen
== 15 &&
5754 !memcmp(type
, "forwarded-tcpip", 15)) {
5755 struct ssh_rportfwd pf
, *realpf
;
5758 ssh2_pkt_getstring(ssh
, &dummy
, &dummylen
);/* skip address */
5759 pf
.sport
= ssh2_pkt_getuint32(ssh
);
5760 realpf
= find234(ssh
->rportfwds
, &pf
, NULL
);
5761 if (realpf
== NULL
) {
5762 error
= "Remote port is not recognised";
5764 char *e
= pfd_newconnect(&c
->u
.pfd
.s
, realpf
->dhost
,
5766 logeventf(ssh
, "Received remote port open request"
5767 " for %s:%d", realpf
->dhost
, realpf
->dport
);
5769 logeventf(ssh
, "Port open failed: %s", e
);
5770 error
= "Port open failed";
5772 logevent("Forwarded port opened successfully");
5773 c
->type
= CHAN_SOCKDATA
;
5776 } else if (typelen
== 22 &&
5777 !memcmp(type
, "auth-agent@openssh.com", 3)) {
5778 if (!ssh
->agentfwd_enabled
)
5779 error
= "Agent forwarding is not enabled";
5781 c
->type
= CHAN_AGENT
; /* identify channel type */
5782 c
->u
.a
.lensofar
= 0;
5785 error
= "Unsupported channel type requested";
5788 c
->remoteid
= remid
;
5790 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN_FAILURE
);
5791 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5792 ssh2_pkt_adduint32(ssh
, SSH2_OPEN_CONNECT_FAILED
);
5793 ssh2_pkt_addstring(ssh
, error
);
5794 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5798 c
->localid
= alloc_channel_id(ssh
);
5800 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5801 c
->v
.v2
.remwindow
= winsize
;
5802 c
->v
.v2
.remmaxpkt
= pktsize
;
5803 bufchain_init(&c
->v
.v2
.outbuffer
);
5804 add234(ssh
->channels
, c
);
5805 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
5806 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5807 ssh2_pkt_adduint32(ssh
, c
->localid
);
5808 ssh2_pkt_adduint32(ssh
, c
->v
.v2
.locwindow
);
5809 ssh2_pkt_adduint32(ssh
, 0x4000UL
); /* our max pkt size */
5813 bombout((ssh
,"Strange packet received: type %d", ssh
->pktin
.type
));
5818 * We have spare data. Add it to the channel buffer.
5820 ssh2_add_channel_data(ssh
->mainchan
, in
, inlen
);
5825 struct ssh_channel
*c
;
5827 * Try to send data on all channels if we can.
5829 for (i
= 0; NULL
!= (c
= index234(ssh
->channels
, i
)); i
++) {
5830 int bufsize
= ssh2_try_send(c
);
5833 case CHAN_MAINSESSION
:
5834 /* stdin need not receive an unthrottle
5835 * notification since it will be polled */
5838 x11_unthrottle(c
->u
.x11
.s
);
5841 /* agent sockets are request/response and need no
5842 * buffer management */
5845 pfd_unthrottle(c
->u
.pfd
.s
);
5857 * Handle the top-level SSH2 protocol.
5859 static void ssh2_protocol(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
5861 if (do_ssh2_transport(ssh
, in
, inlen
, ispkt
) == 0)
5863 do_ssh2_authconn(ssh
, in
, inlen
, ispkt
);
5867 * Called to set up the connection.
5869 * Returns an error message, or NULL on success.
5871 static char *ssh_init(void *frontend_handle
, void **backend_handle
,
5872 char *host
, int port
, char **realhost
, int nodelay
)
5877 ssh
= smalloc(sizeof(*ssh
));
5880 ssh
->v1_cipher_ctx
= NULL
;
5881 ssh
->crcda_ctx
= NULL
;
5882 ssh
->cscipher
= NULL
;
5883 ssh
->cs_cipher_ctx
= NULL
;
5884 ssh
->sccipher
= NULL
;
5885 ssh
->sc_cipher_ctx
= NULL
;
5887 ssh
->cs_mac_ctx
= NULL
;
5889 ssh
->sc_mac_ctx
= NULL
;
5891 ssh
->cs_comp_ctx
= NULL
;
5893 ssh
->sc_comp_ctx
= NULL
;
5895 ssh
->hostkey
= NULL
;
5897 ssh
->state
= SSH_STATE_PREPACKET
;
5898 ssh
->size_needed
= FALSE
;
5899 ssh
->eof_needed
= FALSE
;
5903 static const struct Packet empty
= { 0, 0, NULL
, NULL
, 0 };
5904 ssh
->pktin
= ssh
->pktout
= empty
;
5906 ssh
->deferred_send_data
= NULL
;
5907 ssh
->deferred_len
= 0;
5908 ssh
->deferred_size
= 0;
5909 ssh
->fallback_cmd
= 0;
5911 ssh
->x11auth
= NULL
;
5912 ssh
->v1_compressing
= FALSE
;
5913 ssh
->v2_outgoing_sequence
= 0;
5914 ssh
->ssh1_rdpkt_crstate
= 0;
5915 ssh
->ssh2_rdpkt_crstate
= 0;
5916 ssh
->do_ssh_init_crstate
= 0;
5917 ssh
->ssh_gotdata_crstate
= 0;
5918 ssh
->ssh1_protocol_crstate
= 0;
5919 ssh
->do_ssh1_login_crstate
= 0;
5920 ssh
->do_ssh2_transport_crstate
= 0;
5921 ssh
->do_ssh2_authconn_crstate
= 0;
5922 ssh
->do_ssh_init_state
= NULL
;
5923 ssh
->do_ssh1_login_state
= NULL
;
5924 ssh
->do_ssh2_transport_state
= NULL
;
5925 ssh
->do_ssh2_authconn_state
= NULL
;
5926 ssh
->mainchan
= NULL
;
5927 ssh
->throttled_all
= 0;
5928 ssh
->v1_stdout_throttling
= 0;
5930 *backend_handle
= ssh
;
5933 if (crypto_startup() == 0)
5934 return "Microsoft high encryption pack not installed!";
5937 ssh
->frontend
= frontend_handle
;
5938 ssh
->term_width
= cfg
.width
;
5939 ssh
->term_height
= cfg
.height
;
5944 ssh
->v1_throttle_count
= 0;
5945 ssh
->overall_bufsize
= 0;
5946 ssh
->fallback_cmd
= 0;
5948 p
= connect_to_host(ssh
, host
, port
, realhost
, nodelay
);
5956 * Called to send data down the Telnet connection.
5958 static int ssh_send(void *handle
, char *buf
, int len
)
5960 Ssh ssh
= (Ssh
) handle
;
5962 if (ssh
== NULL
|| ssh
->s
== NULL
|| ssh
->protocol
== NULL
)
5965 ssh
->protocol(ssh
, buf
, len
, 0);
5967 return ssh_sendbuffer(ssh
);
5971 * Called to query the current amount of buffered stdin data.
5973 static int ssh_sendbuffer(void *handle
)
5975 Ssh ssh
= (Ssh
) handle
;
5978 if (ssh
== NULL
|| ssh
->s
== NULL
|| ssh
->protocol
== NULL
)
5982 * If the SSH socket itself has backed up, add the total backup
5983 * size on that to any individual buffer on the stdin channel.
5986 if (ssh
->throttled_all
)
5987 override_value
= ssh
->overall_bufsize
;
5989 if (ssh
->version
== 1) {
5990 return override_value
;
5991 } else if (ssh
->version
== 2) {
5992 if (!ssh
->mainchan
|| ssh
->mainchan
->closes
> 0)
5993 return override_value
;
5995 return (override_value
+
5996 bufchain_size(&ssh
->mainchan
->v
.v2
.outbuffer
));
6003 * Called to set the size of the window from SSH's POV.
6005 static void ssh_size(void *handle
, int width
, int height
)
6007 Ssh ssh
= (Ssh
) handle
;
6009 ssh
->term_width
= width
;
6010 ssh
->term_height
= height
;
6012 switch (ssh
->state
) {
6013 case SSH_STATE_BEFORE_SIZE
:
6014 case SSH_STATE_PREPACKET
:
6015 case SSH_STATE_CLOSED
:
6016 break; /* do nothing */
6017 case SSH_STATE_INTERMED
:
6018 ssh
->size_needed
= TRUE
; /* buffer for later */
6020 case SSH_STATE_SESSION
:
6022 if (ssh
->version
== 1) {
6023 send_packet(ssh
, SSH1_CMSG_WINDOW_SIZE
,
6024 PKT_INT
, ssh
->term_height
,
6025 PKT_INT
, ssh
->term_width
,
6026 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
6028 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
6029 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
6030 ssh2_pkt_addstring(ssh
, "window-change");
6031 ssh2_pkt_addbool(ssh
, 0);
6032 ssh2_pkt_adduint32(ssh
, ssh
->term_width
);
6033 ssh2_pkt_adduint32(ssh
, ssh
->term_height
);
6034 ssh2_pkt_adduint32(ssh
, 0);
6035 ssh2_pkt_adduint32(ssh
, 0);
6044 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6045 * can send an EOF and collect resulting output (e.g. `plink
6048 static void ssh_special(void *handle
, Telnet_Special code
)
6050 Ssh ssh
= (Ssh
) handle
;
6052 if (code
== TS_EOF
) {
6053 if (ssh
->state
!= SSH_STATE_SESSION
) {
6055 * Buffer the EOF in case we are pre-SESSION, so we can
6056 * send it as soon as we reach SESSION.
6059 ssh
->eof_needed
= TRUE
;
6062 if (ssh
->version
== 1) {
6063 send_packet(ssh
, SSH1_CMSG_EOF
, PKT_END
);
6065 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_EOF
);
6066 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
6069 logevent("Sent EOF message");
6070 } else if (code
== TS_PING
) {
6071 if (ssh
->state
== SSH_STATE_CLOSED
6072 || ssh
->state
== SSH_STATE_PREPACKET
) return;
6073 if (ssh
->version
== 1) {
6074 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
))
6075 send_packet(ssh
, SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
6077 ssh2_pkt_init(ssh
, SSH2_MSG_IGNORE
);
6078 ssh2_pkt_addstring_start(ssh
);
6086 void *new_sock_channel(void *handle
, Socket s
)
6088 Ssh ssh
= (Ssh
) handle
;
6089 struct ssh_channel
*c
;
6090 c
= smalloc(sizeof(struct ssh_channel
));
6094 c
->remoteid
= -1; /* to be set when open confirmed */
6095 c
->localid
= alloc_channel_id(ssh
);
6097 c
->type
= CHAN_SOCKDATA_DORMANT
;/* identify channel type */
6099 bufchain_init(&c
->v
.v2
.outbuffer
);
6100 add234(ssh
->channels
, c
);
6106 * This is called when stdout/stderr (the entity to which
6107 * from_backend sends data) manages to clear some backlog.
6109 void ssh_unthrottle(void *handle
, int bufsize
)
6111 Ssh ssh
= (Ssh
) handle
;
6112 if (ssh
->version
== 1) {
6113 if (ssh
->v1_stdout_throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
6114 ssh
->v1_stdout_throttling
= 0;
6115 ssh1_throttle(ssh
, -1);
6118 if (ssh
->mainchan
&& ssh
->mainchan
->closes
== 0)
6119 ssh2_set_window(ssh
->mainchan
, OUR_V2_WINSIZE
- bufsize
);
6123 void ssh_send_port_open(void *channel
, char *hostname
, int port
, char *org
)
6125 struct ssh_channel
*c
= (struct ssh_channel
*)channel
;
6128 logeventf(ssh
, "Opening forwarded connection to %s:%d", hostname
, port
);
6130 if (ssh
->version
== 1) {
6131 send_packet(ssh
, SSH1_MSG_PORT_OPEN
,
6132 PKT_INT
, c
->localid
,
6135 //PKT_STR, <org:orgport>,
6138 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN
);
6139 ssh2_pkt_addstring(ssh
, "direct-tcpip");
6140 ssh2_pkt_adduint32(ssh
, c
->localid
);
6141 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
6142 ssh2_pkt_adduint32(ssh
, c
->v
.v2
.locwindow
);/* our window size */
6143 ssh2_pkt_adduint32(ssh
, 0x4000UL
); /* our max pkt size */
6144 ssh2_pkt_addstring(ssh
, hostname
);
6145 ssh2_pkt_adduint32(ssh
, port
);
6147 * We make up values for the originator data; partly it's
6148 * too much hassle to keep track, and partly I'm not
6149 * convinced the server should be told details like that
6150 * about my local network configuration.
6152 ssh2_pkt_addstring(ssh
, "client-side-connection");
6153 ssh2_pkt_adduint32(ssh
, 0);
6159 static Socket
ssh_socket(void *handle
)
6161 Ssh ssh
= (Ssh
) handle
;
6165 static int ssh_sendok(void *handle
)
6167 Ssh ssh
= (Ssh
) handle
;
6168 return ssh
->send_ok
;
6171 static int ssh_ldisc(void *handle
, int option
)
6173 Ssh ssh
= (Ssh
) handle
;
6174 if (option
== LD_ECHO
)
6175 return ssh
->echoing
;
6176 if (option
== LD_EDIT
)
6177 return ssh
->editing
;
6181 static void ssh_provide_ldisc(void *handle
, void *ldisc
)
6183 Ssh ssh
= (Ssh
) handle
;
6187 static void ssh_provide_logctx(void *handle
, void *logctx
)
6189 Ssh ssh
= (Ssh
) handle
;
6190 ssh
->logctx
= logctx
;
6193 static int ssh_return_exitcode(void *handle
)
6195 Ssh ssh
= (Ssh
) handle
;
6196 return ssh
->exitcode
;
6200 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6201 * that fails. This variable is the means by which scp.c can reach
6202 * into the SSH code and find out which one it got.
6204 extern int ssh_fallback_cmd(void *handle
)
6206 Ssh ssh
= (Ssh
) handle
;
6207 return ssh
->fallback_cmd
;
6210 Backend ssh_backend
= {
6217 ssh_return_exitcode
,