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 static 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 static 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 static void ssh2_pkt_init(Ssh
, int pkt_type
);
295 static void ssh2_pkt_addbool(Ssh
, unsigned char value
);
296 static void ssh2_pkt_adduint32(Ssh
, unsigned long value
);
297 static void ssh2_pkt_addstring_start(Ssh
);
298 static void ssh2_pkt_addstring_str(Ssh
, char *data
);
299 static void ssh2_pkt_addstring_data(Ssh
, char *data
, int len
);
300 static void ssh2_pkt_addstring(Ssh
, char *data
);
301 static unsigned char *ssh2_mpint_fmt(Bignum b
, int *len
);
302 static void ssh2_pkt_addmp(Ssh
, Bignum b
);
303 static int ssh2_pkt_construct(Ssh
);
304 static void ssh2_pkt_send(Ssh
);
307 * Buffer management constants. There are several of these for
308 * various different purposes:
310 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
311 * on a local data stream before we throttle the whole SSH
312 * connection (in SSH1 only). Throttling the whole connection is
313 * pretty drastic so we set this high in the hope it won't
316 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
317 * on the SSH connection itself before we defensively throttle
318 * _all_ local data streams. This is pretty drastic too (though
319 * thankfully unlikely in SSH2 since the window mechanism should
320 * ensure that the server never has any need to throttle its end
321 * of the connection), so we set this high as well.
323 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
327 #define SSH1_BUFFER_LIMIT 32768
328 #define SSH_MAX_BACKLOG 32768
329 #define OUR_V2_WINSIZE 16384
331 const static struct ssh_kex
*kex_algs
[] = {
332 &ssh_diffiehellman_gex
,
336 const static struct ssh_signkey
*hostkey_algs
[] = { &ssh_rsa
, &ssh_dss
};
338 static void *nullmac_make_context(void)
342 static void nullmac_free_context(void *handle
)
345 static void nullmac_key(void *handle
, unsigned char *key
)
348 static void nullmac_generate(void *handle
, unsigned char *blk
, int len
,
352 static int nullmac_verify(void *handle
, unsigned char *blk
, int len
,
357 const static struct ssh_mac ssh_mac_none
= {
358 nullmac_make_context
, nullmac_free_context
, nullmac_key
,
359 nullmac_generate
, nullmac_verify
, "none", 0
361 const static struct ssh_mac
*macs
[] = {
362 &ssh_sha1
, &ssh_md5
, &ssh_mac_none
364 const static struct ssh_mac
*buggymacs
[] = {
365 &ssh_sha1_buggy
, &ssh_md5
, &ssh_mac_none
368 static void *ssh_comp_none_init(void)
372 static void ssh_comp_none_cleanup(void *handle
)
375 static int ssh_comp_none_block(void *handle
, unsigned char *block
, int len
,
376 unsigned char **outblock
, int *outlen
)
380 static int ssh_comp_none_disable(void *handle
)
384 const static struct ssh_compress ssh_comp_none
= {
386 ssh_comp_none_init
, ssh_comp_none_cleanup
, ssh_comp_none_block
,
387 ssh_comp_none_init
, ssh_comp_none_cleanup
, ssh_comp_none_block
,
388 ssh_comp_none_disable
, NULL
390 extern const struct ssh_compress ssh_zlib
;
391 const static struct ssh_compress
*compressions
[] = {
392 &ssh_zlib
, &ssh_comp_none
395 enum { /* channel types */
400 CHAN_SOCKDATA_DORMANT
/* one the remote hasn't confirmed */
404 * 2-3-4 tree storing channels.
407 Ssh ssh
; /* pointer back to main context */
408 unsigned remoteid
, localid
;
411 * In SSH1, this value contains four bits:
413 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
414 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
415 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
416 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
418 * A channel is completely finished with when all four bits are set.
422 struct ssh1_data_channel
{
425 struct ssh2_data_channel
{
427 unsigned remwindow
, remmaxpkt
;
432 struct ssh_agent_channel
{
433 unsigned char *message
;
434 unsigned char msglen
[4];
435 int lensofar
, totallen
;
437 struct ssh_x11_channel
{
440 struct ssh_pfd_channel
{
447 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
448 * 2 use this structure in different ways, reflecting SSH 2's
449 * altogether saner approach to port forwarding.
451 * In SSH 1, you arrange a remote forwarding by sending the server
452 * the remote port number, and the local destination host:port.
453 * When a connection comes in, the server sends you back that
454 * host:port pair, and you connect to it. This is a ready-made
455 * security hole if you're not on the ball: a malicious server
456 * could send you back _any_ host:port pair, so if you trustingly
457 * connect to the address it gives you then you've just opened the
458 * entire inside of your corporate network just by connecting
459 * through it to a dodgy SSH server. Hence, we must store a list of
460 * host:port pairs we _are_ trying to forward to, and reject a
461 * connection request from the server if it's not in the list.
463 * In SSH 2, each side of the connection minds its own business and
464 * doesn't send unnecessary information to the other. You arrange a
465 * remote forwarding by sending the server just the remote port
466 * number. When a connection comes in, the server tells you which
467 * of its ports was connected to; and _you_ have to remember what
468 * local host:port pair went with that port number.
470 * Hence: in SSH 1 this structure stores host:port pairs we intend
471 * to allow connections to, and is indexed by those host:port
472 * pairs. In SSH 2 it stores a mapping from source port to
473 * destination host:port pair, and is indexed by source port.
475 struct ssh_rportfwd
{
476 unsigned sport
, dport
;
489 static void ssh1_protocol(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
);
490 static void ssh2_protocol(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
);
491 static void ssh_size(void *handle
, int width
, int height
);
492 static void ssh_special(void *handle
, Telnet_Special
);
493 static int ssh2_try_send(struct ssh_channel
*c
);
494 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
, int len
);
495 static void ssh_throttle_all(Ssh ssh
, int enable
, int bufsize
);
496 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
);
497 static int ssh_sendbuffer(void *handle
);
499 struct rdpkt1_state_tag
{
500 long len
, pad
, biglen
, to_read
;
501 unsigned long realcrc
, gotcrc
;
507 struct rdpkt2_state_tag
{
508 long len
, pad
, payload
, packetlen
, maclen
;
511 unsigned long incoming_sequence
;
515 const struct plug_function_table
*fn
;
516 /* the above field _must_ be first in the structure */
518 SHA_State exhash
, exhashbase
;
525 unsigned char session_key
[32];
527 int v1_remote_protoflags
;
528 int v1_local_protoflags
;
529 int agentfwd_enabled
;
532 const struct ssh_cipher
*cipher
;
535 const struct ssh2_cipher
*cscipher
, *sccipher
;
536 void *cs_cipher_ctx
, *sc_cipher_ctx
;
537 const struct ssh_mac
*csmac
, *scmac
;
538 void *cs_mac_ctx
, *sc_mac_ctx
;
539 const struct ssh_compress
*cscomp
, *sccomp
;
540 void *cs_comp_ctx
, *sc_comp_ctx
;
541 const struct ssh_kex
*kex
;
542 const struct ssh_signkey
*hostkey
;
543 unsigned char v2_session_id
[20];
549 int echoing
, editing
;
553 int term_width
, term_height
;
555 tree234
*channels
; /* indexed by local id */
556 struct ssh_channel
*mainchan
; /* primary session channel */
563 SSH_STATE_BEFORE_SIZE
,
569 int size_needed
, eof_needed
;
572 struct Packet pktout
;
573 unsigned char *deferred_send_data
;
574 int deferred_len
, deferred_size
;
577 * Gross hack: pscp will try to start SFTP but fall back to
578 * scp1 if that fails. This variable is the means by which
579 * scp.c can reach into the SSH code and find out which one it
585 * Used for username and password input.
587 char *userpass_input_buffer
;
588 int userpass_input_buflen
;
589 int userpass_input_bufpos
;
590 int userpass_input_echo
;
592 char *portfwd_strptr
;
598 int v1_throttle_count
;
601 int v1_stdout_throttling
;
602 int v2_outgoing_sequence
;
604 int ssh1_rdpkt_crstate
;
605 int ssh2_rdpkt_crstate
;
606 int do_ssh_init_crstate
;
607 int ssh_gotdata_crstate
;
608 int ssh1_protocol_crstate
;
609 int do_ssh1_login_crstate
;
610 int do_ssh2_transport_crstate
;
611 int do_ssh2_authconn_crstate
;
613 void *do_ssh_init_state
;
614 void *do_ssh1_login_state
;
615 void *do_ssh2_transport_state
;
616 void *do_ssh2_authconn_state
;
618 struct rdpkt1_state_tag rdpkt1_state
;
619 struct rdpkt2_state_tag rdpkt2_state
;
621 void (*protocol
) (Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
);
622 int (*s_rdpkt
) (Ssh ssh
, unsigned char **data
, int *datalen
);
625 #define logevent(s) logevent(ssh->frontend, s)
627 /* logevent, only printf-formatted. */
628 static void logeventf(Ssh ssh
, char *fmt
, ...)
634 buf
= dupvprintf(fmt
, ap
);
640 #define bombout(msg) ( ssh->state = SSH_STATE_CLOSED, \
641 (ssh->s ? sk_close(ssh->s), ssh->s = NULL : 0), \
642 logeventf msg, connection_fatal msg )
644 static int ssh_channelcmp(void *av
, void *bv
)
646 struct ssh_channel
*a
= (struct ssh_channel
*) av
;
647 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
648 if (a
->localid
< b
->localid
)
650 if (a
->localid
> b
->localid
)
654 static int ssh_channelfind(void *av
, void *bv
)
656 unsigned *a
= (unsigned *) av
;
657 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
665 static int ssh_rportcmp_ssh1(void *av
, void *bv
)
667 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
668 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
670 if ( (i
= strcmp(a
->dhost
, b
->dhost
)) != 0)
671 return i
< 0 ?
-1 : +1;
672 if (a
->dport
> b
->dport
)
674 if (a
->dport
< b
->dport
)
679 static int ssh_rportcmp_ssh2(void *av
, void *bv
)
681 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
682 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
684 if (a
->sport
> b
->sport
)
686 if (a
->sport
< b
->sport
)
691 static int alloc_channel_id(Ssh ssh
)
693 const unsigned CHANNEL_NUMBER_OFFSET
= 256;
694 unsigned low
, high
, mid
;
696 struct ssh_channel
*c
;
699 * First-fit allocation of channel numbers: always pick the
700 * lowest unused one. To do this, binary-search using the
701 * counted B-tree to find the largest channel ID which is in a
702 * contiguous sequence from the beginning. (Precisely
703 * everything in that sequence must have ID equal to its tree
704 * index plus CHANNEL_NUMBER_OFFSET.)
706 tsize
= count234(ssh
->channels
);
710 while (high
- low
> 1) {
711 mid
= (high
+ low
) / 2;
712 c
= index234(ssh
->channels
, mid
);
713 if (c
->localid
== mid
+ CHANNEL_NUMBER_OFFSET
)
714 low
= mid
; /* this one is fine */
716 high
= mid
; /* this one is past it */
719 * Now low points to either -1, or the tree index of the
720 * largest ID in the initial sequence.
723 unsigned i
= low
+ 1 + CHANNEL_NUMBER_OFFSET
;
724 assert(NULL
== find234(ssh
->channels
, &i
, ssh_channelfind
));
726 return low
+ 1 + CHANNEL_NUMBER_OFFSET
;
729 static void c_write(Ssh ssh
, char *buf
, int len
)
731 if ((flags
& FLAG_STDERR
)) {
733 for (i
= 0; i
< len
; i
++)
735 fputc(buf
[i
], stderr
);
738 from_backend(ssh
->frontend
, 1, buf
, len
);
741 static void c_write_untrusted(Ssh ssh
, char *buf
, int len
)
744 for (i
= 0; i
< len
; i
++) {
746 c_write(ssh
, "\r\n", 2);
747 else if ((buf
[i
] & 0x60) || (buf
[i
] == '\r'))
748 c_write(ssh
, buf
+ i
, 1);
752 static void c_write_str(Ssh ssh
, char *buf
)
754 c_write(ssh
, buf
, strlen(buf
));
758 * Collect incoming data in the incoming packet buffer.
759 * Decipher and verify the packet when it is completely read.
760 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
761 * Update the *data and *datalen variables.
762 * Return the additional nr of bytes needed, or 0 when
763 * a complete packet is available.
765 static int ssh1_rdpkt(Ssh ssh
, unsigned char **data
, int *datalen
)
767 struct rdpkt1_state_tag
*st
= &ssh
->rdpkt1_state
;
769 crBegin(ssh
->ssh1_rdpkt_crstate
);
774 ssh
->pktin
.length
= 0;
776 for (st
->i
= st
->len
= 0; st
->i
< 4; st
->i
++) {
777 while ((*datalen
) == 0)
779 st
->len
= (st
->len
<< 8) + **data
;
780 (*data
)++, (*datalen
)--;
783 st
->pad
= 8 - (st
->len
% 8);
784 st
->biglen
= st
->len
+ st
->pad
;
785 ssh
->pktin
.length
= st
->len
- 5;
787 if (ssh
->pktin
.maxlen
< st
->biglen
) {
788 ssh
->pktin
.maxlen
= st
->biglen
;
789 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
, st
->biglen
+ APIEXTRA
);
792 st
->to_read
= st
->biglen
;
793 st
->p
= ssh
->pktin
.data
;
794 while (st
->to_read
> 0) {
795 st
->chunk
= st
->to_read
;
796 while ((*datalen
) == 0)
797 crReturn(st
->to_read
);
798 if (st
->chunk
> (*datalen
))
799 st
->chunk
= (*datalen
);
800 memcpy(st
->p
, *data
, st
->chunk
);
802 *datalen
-= st
->chunk
;
804 st
->to_read
-= st
->chunk
;
807 if (ssh
->cipher
&& detect_attack(ssh
->crcda_ctx
, ssh
->pktin
.data
,
809 bombout((ssh
,"Network attack (CRC compensation) detected!"));
814 ssh
->cipher
->decrypt(ssh
->v1_cipher_ctx
, ssh
->pktin
.data
, st
->biglen
);
816 st
->realcrc
= crc32(ssh
->pktin
.data
, st
->biglen
- 4);
817 st
->gotcrc
= GET_32BIT(ssh
->pktin
.data
+ st
->biglen
- 4);
818 if (st
->gotcrc
!= st
->realcrc
) {
819 bombout((ssh
,"Incorrect CRC received on packet"));
823 ssh
->pktin
.body
= ssh
->pktin
.data
+ st
->pad
+ 1;
825 if (ssh
->v1_compressing
) {
826 unsigned char *decompblk
;
828 zlib_decompress_block(ssh
->sc_comp_ctx
,
829 ssh
->pktin
.body
- 1, ssh
->pktin
.length
+ 1,
830 &decompblk
, &decomplen
);
832 if (ssh
->pktin
.maxlen
< st
->pad
+ decomplen
) {
833 ssh
->pktin
.maxlen
= st
->pad
+ decomplen
;
834 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
,
835 ssh
->pktin
.maxlen
+ APIEXTRA
);
836 ssh
->pktin
.body
= ssh
->pktin
.data
+ st
->pad
+ 1;
839 memcpy(ssh
->pktin
.body
- 1, decompblk
, decomplen
);
841 ssh
->pktin
.length
= decomplen
- 1;
844 ssh
->pktin
.type
= ssh
->pktin
.body
[-1];
847 log_packet(ssh
->logctx
,
848 PKT_INCOMING
, ssh
->pktin
.type
,
849 ssh1_pkt_type(ssh
->pktin
.type
),
850 ssh
->pktin
.body
, ssh
->pktin
.length
);
852 if (ssh
->pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
853 ssh
->pktin
.type
== SSH1_SMSG_STDERR_DATA
||
854 ssh
->pktin
.type
== SSH1_MSG_DEBUG
||
855 ssh
->pktin
.type
== SSH1_SMSG_AUTH_TIS_CHALLENGE
||
856 ssh
->pktin
.type
== SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
857 long stringlen
= GET_32BIT(ssh
->pktin
.body
);
858 if (stringlen
+ 4 != ssh
->pktin
.length
) {
859 bombout((ssh
,"Received data packet with bogus string length"));
864 if (ssh
->pktin
.type
== SSH1_MSG_DEBUG
) {
865 /* log debug message */
867 int stringlen
= GET_32BIT(ssh
->pktin
.body
);
868 strcpy(buf
, "Remote debug message: ");
871 memcpy(buf
+ 8, ssh
->pktin
.body
+ 4, stringlen
);
872 buf
[8 + stringlen
] = '\0';
875 } else if (ssh
->pktin
.type
== SSH1_MSG_IGNORE
) {
880 if (ssh
->pktin
.type
== SSH1_MSG_DISCONNECT
) {
881 /* log reason code in disconnect message */
883 unsigned msglen
= GET_32BIT(ssh
->pktin
.body
);
885 strcpy(buf
, "Remote sent disconnect: ");
886 nowlen
= strlen(buf
);
887 if (msglen
> sizeof(buf
) - nowlen
- 1)
888 msglen
= sizeof(buf
) - nowlen
- 1;
889 memcpy(buf
+ nowlen
, ssh
->pktin
.body
+ 4, msglen
);
890 buf
[nowlen
+ msglen
] = '\0';
891 /* logevent(buf); (this is now done within the bombout macro) */
892 bombout((ssh
,"Server sent disconnect message:\n\"%s\"", buf
+nowlen
));
899 static int ssh2_rdpkt(Ssh ssh
, unsigned char **data
, int *datalen
)
901 struct rdpkt2_state_tag
*st
= &ssh
->rdpkt2_state
;
903 crBegin(ssh
->ssh2_rdpkt_crstate
);
907 ssh
->pktin
.length
= 0;
909 st
->cipherblk
= ssh
->sccipher
->blksize
;
912 if (st
->cipherblk
< 8)
915 if (ssh
->pktin
.maxlen
< st
->cipherblk
) {
916 ssh
->pktin
.maxlen
= st
->cipherblk
;
917 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
, st
->cipherblk
+ APIEXTRA
);
921 * Acquire and decrypt the first block of the packet. This will
922 * contain the length and padding details.
924 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
925 while ((*datalen
) == 0)
926 crReturn(st
->cipherblk
- st
->i
);
927 ssh
->pktin
.data
[st
->i
] = *(*data
)++;
932 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
933 ssh
->pktin
.data
, st
->cipherblk
);
936 * Now get the length and padding figures.
938 st
->len
= GET_32BIT(ssh
->pktin
.data
);
939 st
->pad
= ssh
->pktin
.data
[4];
942 * _Completely_ silly lengths should be stomped on before they
943 * do us any more damage.
945 if (st
->len
< 0 || st
->pad
< 0 || st
->len
+ st
->pad
< 0) {
946 bombout((ssh
,"Incoming packet was garbled on decryption"));
951 * This enables us to deduce the payload length.
953 st
->payload
= st
->len
- st
->pad
- 1;
955 ssh
->pktin
.length
= st
->payload
+ 5;
958 * So now we can work out the total packet length.
960 st
->packetlen
= st
->len
+ 4;
961 st
->maclen
= ssh
->scmac ? ssh
->scmac
->len
: 0;
964 * Adjust memory allocation if packet is too big.
966 if (ssh
->pktin
.maxlen
< st
->packetlen
+ st
->maclen
) {
967 ssh
->pktin
.maxlen
= st
->packetlen
+ st
->maclen
;
968 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
,
969 ssh
->pktin
.maxlen
+ APIEXTRA
);
973 * Read and decrypt the remainder of the packet.
975 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
;
977 while ((*datalen
) == 0)
978 crReturn(st
->packetlen
+ st
->maclen
- st
->i
);
979 ssh
->pktin
.data
[st
->i
] = *(*data
)++;
982 /* Decrypt everything _except_ the MAC. */
984 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
985 ssh
->pktin
.data
+ st
->cipherblk
,
986 st
->packetlen
- st
->cipherblk
);
992 && !ssh
->scmac
->verify(ssh
->sc_mac_ctx
, ssh
->pktin
.data
, st
->len
+ 4,
993 st
->incoming_sequence
)) {
994 bombout((ssh
,"Incorrect MAC received on packet"));
997 st
->incoming_sequence
++; /* whether or not we MACed */
1000 * Decompress packet payload.
1003 unsigned char *newpayload
;
1006 ssh
->sccomp
->decompress(ssh
->sc_comp_ctx
,
1007 ssh
->pktin
.data
+ 5, ssh
->pktin
.length
- 5,
1008 &newpayload
, &newlen
)) {
1009 if (ssh
->pktin
.maxlen
< newlen
+ 5) {
1010 ssh
->pktin
.maxlen
= newlen
+ 5;
1011 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
,
1012 ssh
->pktin
.maxlen
+ APIEXTRA
);
1014 ssh
->pktin
.length
= 5 + newlen
;
1015 memcpy(ssh
->pktin
.data
+ 5, newpayload
, newlen
);
1020 ssh
->pktin
.savedpos
= 6;
1021 ssh
->pktin
.type
= ssh
->pktin
.data
[5];
1024 log_packet(ssh
->logctx
, PKT_INCOMING
, ssh
->pktin
.type
,
1025 ssh2_pkt_type(ssh
->pkt_ctx
, ssh
->pktin
.type
),
1026 ssh
->pktin
.data
+6, ssh
->pktin
.length
-6);
1028 switch (ssh
->pktin
.type
) {
1030 * These packets we must handle instantly.
1032 case SSH2_MSG_DISCONNECT
:
1034 /* log reason code in disconnect message */
1037 int reason
= GET_32BIT(ssh
->pktin
.data
+ 6);
1038 unsigned msglen
= GET_32BIT(ssh
->pktin
.data
+ 10);
1040 if (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) {
1041 buf
= dupprintf("Received disconnect message (%s)",
1042 ssh2_disconnect_reasons
[reason
]);
1044 buf
= dupprintf("Received disconnect message (unknown"
1045 " type %d)", reason
);
1049 buf
= dupprintf("Disconnection message text: %n%.*s",
1050 &nowlen
, msglen
, ssh
->pktin
.data
+ 14);
1052 bombout((ssh
,"Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1054 (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) ?
1055 ssh2_disconnect_reasons
[reason
] : "unknown",
1061 case SSH2_MSG_IGNORE
:
1063 case SSH2_MSG_DEBUG
:
1065 /* log the debug message */
1067 /* int display = ssh->pktin.body[6]; */
1068 int stringlen
= GET_32BIT(ssh
->pktin
.data
+7);
1070 strcpy(buf
, "Remote debug message: ");
1071 prefix
= strlen(buf
);
1072 if (stringlen
> (int)(sizeof(buf
)-prefix
-1))
1073 stringlen
= sizeof(buf
)-prefix
-1;
1074 memcpy(buf
+ prefix
, ssh
->pktin
.data
+ 11, stringlen
);
1075 buf
[prefix
+ stringlen
] = '\0';
1078 goto next_packet
; /* FIXME: print the debug message */
1081 * These packets we need do nothing about here.
1083 case SSH2_MSG_UNIMPLEMENTED
:
1084 case SSH2_MSG_SERVICE_REQUEST
:
1085 case SSH2_MSG_SERVICE_ACCEPT
:
1086 case SSH2_MSG_KEXINIT
:
1087 case SSH2_MSG_NEWKEYS
:
1088 case SSH2_MSG_KEXDH_INIT
:
1089 case SSH2_MSG_KEXDH_REPLY
:
1090 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1091 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1092 case SSH2_MSG_KEX_DH_GEX_INIT
:
1093 case SSH2_MSG_KEX_DH_GEX_REPLY
:
1094 case SSH2_MSG_USERAUTH_REQUEST
:
1095 case SSH2_MSG_USERAUTH_FAILURE
:
1096 case SSH2_MSG_USERAUTH_SUCCESS
:
1097 case SSH2_MSG_USERAUTH_BANNER
:
1098 case SSH2_MSG_USERAUTH_PK_OK
:
1099 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1100 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1101 case SSH2_MSG_USERAUTH_INFO_RESPONSE
:
1102 case SSH2_MSG_GLOBAL_REQUEST
:
1103 case SSH2_MSG_REQUEST_SUCCESS
:
1104 case SSH2_MSG_REQUEST_FAILURE
:
1105 case SSH2_MSG_CHANNEL_OPEN
:
1106 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
:
1107 case SSH2_MSG_CHANNEL_OPEN_FAILURE
:
1108 case SSH2_MSG_CHANNEL_WINDOW_ADJUST
:
1109 case SSH2_MSG_CHANNEL_DATA
:
1110 case SSH2_MSG_CHANNEL_EXTENDED_DATA
:
1111 case SSH2_MSG_CHANNEL_EOF
:
1112 case SSH2_MSG_CHANNEL_CLOSE
:
1113 case SSH2_MSG_CHANNEL_REQUEST
:
1114 case SSH2_MSG_CHANNEL_SUCCESS
:
1115 case SSH2_MSG_CHANNEL_FAILURE
:
1119 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1122 ssh2_pkt_init(ssh
, SSH2_MSG_UNIMPLEMENTED
);
1123 ssh2_pkt_adduint32(ssh
, st
->incoming_sequence
- 1);
1131 static void ssh1_pktout_size(Ssh ssh
, int len
)
1135 len
+= 5; /* type and CRC */
1136 pad
= 8 - (len
% 8);
1139 ssh
->pktout
.length
= len
- 5;
1140 if (ssh
->pktout
.maxlen
< biglen
) {
1141 ssh
->pktout
.maxlen
= biglen
;
1143 /* Allocate enough buffer space for extra block
1144 * for MS CryptEncrypt() */
1145 ssh
->pktout
.data
= srealloc(ssh
->pktout
.data
, biglen
+ 12);
1147 ssh
->pktout
.data
= srealloc(ssh
->pktout
.data
, biglen
+ 4);
1150 ssh
->pktout
.body
= ssh
->pktout
.data
+ 4 + pad
+ 1;
1153 static void s_wrpkt_start(Ssh ssh
, int type
, int len
)
1155 ssh1_pktout_size(ssh
, len
);
1156 ssh
->pktout
.type
= type
;
1159 static int s_wrpkt_prepare(Ssh ssh
)
1161 int pad
, len
, biglen
, i
;
1164 ssh
->pktout
.body
[-1] = ssh
->pktout
.type
;
1167 log_packet(ssh
->logctx
, PKT_OUTGOING
, ssh
->pktout
.type
,
1168 ssh1_pkt_type(ssh
->pktout
.type
),
1169 ssh
->pktout
.body
, ssh
->pktout
.length
);
1171 if (ssh
->v1_compressing
) {
1172 unsigned char *compblk
;
1174 zlib_compress_block(ssh
->cs_comp_ctx
,
1175 ssh
->pktout
.body
- 1, ssh
->pktout
.length
+ 1,
1176 &compblk
, &complen
);
1177 ssh1_pktout_size(ssh
, complen
- 1);
1178 memcpy(ssh
->pktout
.body
- 1, compblk
, complen
);
1182 len
= ssh
->pktout
.length
+ 5; /* type and CRC */
1183 pad
= 8 - (len
% 8);
1186 for (i
= 0; i
< pad
; i
++)
1187 ssh
->pktout
.data
[i
+ 4] = random_byte();
1188 crc
= crc32(ssh
->pktout
.data
+ 4, biglen
- 4);
1189 PUT_32BIT(ssh
->pktout
.data
+ biglen
, crc
);
1190 PUT_32BIT(ssh
->pktout
.data
, len
);
1193 ssh
->cipher
->encrypt(ssh
->v1_cipher_ctx
, ssh
->pktout
.data
+ 4, biglen
);
1198 static void s_wrpkt(Ssh ssh
)
1201 len
= s_wrpkt_prepare(ssh
);
1202 backlog
= sk_write(ssh
->s
, (char *)ssh
->pktout
.data
, len
);
1203 if (backlog
> SSH_MAX_BACKLOG
)
1204 ssh_throttle_all(ssh
, 1, backlog
);
1207 static void s_wrpkt_defer(Ssh ssh
)
1210 len
= s_wrpkt_prepare(ssh
);
1211 if (ssh
->deferred_len
+ len
> ssh
->deferred_size
) {
1212 ssh
->deferred_size
= ssh
->deferred_len
+ len
+ 128;
1213 ssh
->deferred_send_data
= srealloc(ssh
->deferred_send_data
,
1214 ssh
->deferred_size
);
1216 memcpy(ssh
->deferred_send_data
+ ssh
->deferred_len
, ssh
->pktout
.data
, len
);
1217 ssh
->deferred_len
+= len
;
1221 * Construct a packet with the specified contents.
1223 static void construct_packet(Ssh ssh
, int pkttype
, va_list ap1
, va_list ap2
)
1225 unsigned char *p
, *argp
, argchar
;
1226 unsigned long argint
;
1227 int pktlen
, argtype
, arglen
;
1231 while ((argtype
= va_arg(ap1
, int)) != PKT_END
) {
1234 (void) va_arg(ap1
, int);
1238 (void) va_arg(ap1
, int);
1242 (void) va_arg(ap1
, unsigned char *);
1243 arglen
= va_arg(ap1
, int);
1247 argp
= va_arg(ap1
, unsigned char *);
1248 arglen
= strlen((char *)argp
);
1249 pktlen
+= 4 + arglen
;
1252 bn
= va_arg(ap1
, Bignum
);
1253 pktlen
+= ssh1_bignum_length(bn
);
1260 s_wrpkt_start(ssh
, pkttype
, pktlen
);
1261 p
= ssh
->pktout
.body
;
1263 while ((argtype
= va_arg(ap2
, int)) != PKT_END
) {
1266 argint
= va_arg(ap2
, int);
1267 PUT_32BIT(p
, argint
);
1271 argchar
= (unsigned char) va_arg(ap2
, int);
1276 argp
= va_arg(ap2
, unsigned char *);
1277 arglen
= va_arg(ap2
, int);
1278 memcpy(p
, argp
, arglen
);
1282 argp
= va_arg(ap2
, unsigned char *);
1283 arglen
= strlen((char *)argp
);
1284 PUT_32BIT(p
, arglen
);
1285 memcpy(p
+ 4, argp
, arglen
);
1289 bn
= va_arg(ap2
, Bignum
);
1290 p
+= ssh1_write_bignum(p
, bn
);
1296 static void send_packet(Ssh ssh
, int pkttype
, ...)
1299 va_start(ap1
, pkttype
);
1300 va_start(ap2
, pkttype
);
1301 construct_packet(ssh
, pkttype
, ap1
, ap2
);
1305 static void defer_packet(Ssh ssh
, int pkttype
, ...)
1308 va_start(ap1
, pkttype
);
1309 va_start(ap2
, pkttype
);
1310 construct_packet(ssh
, pkttype
, ap1
, ap2
);
1314 static int ssh_versioncmp(char *a
, char *b
)
1317 unsigned long av
, bv
;
1319 av
= strtoul(a
, &ae
, 10);
1320 bv
= strtoul(b
, &be
, 10);
1322 return (av
< bv ?
-1 : +1);
1327 av
= strtoul(ae
, &ae
, 10);
1328 bv
= strtoul(be
, &be
, 10);
1330 return (av
< bv ?
-1 : +1);
1335 * Utility routines for putting an SSH-protocol `string' and
1336 * `uint32' into a SHA state.
1339 static void sha_string(SHA_State
* s
, void *str
, int len
)
1341 unsigned char lenblk
[4];
1342 PUT_32BIT(lenblk
, len
);
1343 SHA_Bytes(s
, lenblk
, 4);
1344 SHA_Bytes(s
, str
, len
);
1347 static void sha_uint32(SHA_State
* s
, unsigned i
)
1349 unsigned char intblk
[4];
1350 PUT_32BIT(intblk
, i
);
1351 SHA_Bytes(s
, intblk
, 4);
1355 * SSH2 packet construction functions.
1357 static void ssh2_pkt_ensure(Ssh ssh
, int length
)
1359 if (ssh
->pktout
.maxlen
< length
) {
1360 ssh
->pktout
.maxlen
= length
+ 256;
1361 ssh
->pktout
.data
= srealloc(ssh
->pktout
.data
,
1362 ssh
->pktout
.maxlen
+ APIEXTRA
);
1363 if (!ssh
->pktout
.data
)
1364 fatalbox("Out of memory");
1367 static void ssh2_pkt_adddata(Ssh ssh
, void *data
, int len
)
1369 ssh
->pktout
.length
+= len
;
1370 ssh2_pkt_ensure(ssh
, ssh
->pktout
.length
);
1371 memcpy(ssh
->pktout
.data
+ ssh
->pktout
.length
- len
, data
, len
);
1373 static void ssh2_pkt_addbyte(Ssh ssh
, unsigned char byte
)
1375 ssh2_pkt_adddata(ssh
, &byte
, 1);
1377 static void ssh2_pkt_init(Ssh ssh
, int pkt_type
)
1379 ssh
->pktout
.length
= 5;
1380 ssh2_pkt_addbyte(ssh
, (unsigned char) pkt_type
);
1382 static void ssh2_pkt_addbool(Ssh ssh
, unsigned char value
)
1384 ssh2_pkt_adddata(ssh
, &value
, 1);
1386 static void ssh2_pkt_adduint32(Ssh ssh
, unsigned long value
)
1389 PUT_32BIT(x
, value
);
1390 ssh2_pkt_adddata(ssh
, x
, 4);
1392 static void ssh2_pkt_addstring_start(Ssh ssh
)
1394 ssh2_pkt_adduint32(ssh
, 0);
1395 ssh
->pktout
.savedpos
= ssh
->pktout
.length
;
1397 static void ssh2_pkt_addstring_str(Ssh ssh
, char *data
)
1399 ssh2_pkt_adddata(ssh
, data
, strlen(data
));
1400 PUT_32BIT(ssh
->pktout
.data
+ ssh
->pktout
.savedpos
- 4,
1401 ssh
->pktout
.length
- ssh
->pktout
.savedpos
);
1403 static void ssh2_pkt_addstring_data(Ssh ssh
, char *data
, int len
)
1405 ssh2_pkt_adddata(ssh
, data
, len
);
1406 PUT_32BIT(ssh
->pktout
.data
+ ssh
->pktout
.savedpos
- 4,
1407 ssh
->pktout
.length
- ssh
->pktout
.savedpos
);
1409 static void ssh2_pkt_addstring(Ssh ssh
, char *data
)
1411 ssh2_pkt_addstring_start(ssh
);
1412 ssh2_pkt_addstring_str(ssh
, data
);
1414 static unsigned char *ssh2_mpint_fmt(Bignum b
, int *len
)
1417 int i
, n
= (bignum_bitcount(b
) + 7) / 8;
1420 fatalbox("out of memory");
1422 for (i
= 1; i
<= n
; i
++)
1423 p
[i
] = bignum_byte(b
, n
- i
);
1425 while (i
<= n
&& p
[i
] == 0 && (p
[i
+ 1] & 0x80) == 0)
1427 memmove(p
, p
+ i
, n
+ 1 - i
);
1431 static void ssh2_pkt_addmp(Ssh ssh
, Bignum b
)
1435 p
= ssh2_mpint_fmt(b
, &len
);
1436 ssh2_pkt_addstring_start(ssh
);
1437 ssh2_pkt_addstring_data(ssh
, (char *)p
, len
);
1442 * Construct an SSH2 final-form packet: compress it, encrypt it,
1443 * put the MAC on it. Final packet, ready to be sent, is stored in
1444 * ssh->pktout.data. Total length is returned.
1446 static int ssh2_pkt_construct(Ssh ssh
)
1448 int cipherblk
, maclen
, padding
, i
;
1451 log_packet(ssh
->logctx
, PKT_OUTGOING
, ssh
->pktout
.data
[5],
1452 ssh2_pkt_type(ssh
->pkt_ctx
, ssh
->pktout
.data
[5]),
1453 ssh
->pktout
.data
+ 6, ssh
->pktout
.length
- 6);
1456 * Compress packet payload.
1459 unsigned char *newpayload
;
1462 ssh
->cscomp
->compress(ssh
->cs_comp_ctx
, ssh
->pktout
.data
+ 5,
1463 ssh
->pktout
.length
- 5,
1464 &newpayload
, &newlen
)) {
1465 ssh
->pktout
.length
= 5;
1466 ssh2_pkt_adddata(ssh
, newpayload
, newlen
);
1472 * Add padding. At least four bytes, and must also bring total
1473 * length (minus MAC) up to a multiple of the block size.
1475 cipherblk
= ssh
->cscipher ? ssh
->cscipher
->blksize
: 8; /* block size */
1476 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
1479 (cipherblk
- (ssh
->pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
1480 maclen
= ssh
->csmac ? ssh
->csmac
->len
: 0;
1481 ssh2_pkt_ensure(ssh
, ssh
->pktout
.length
+ padding
+ maclen
);
1482 ssh
->pktout
.data
[4] = padding
;
1483 for (i
= 0; i
< padding
; i
++)
1484 ssh
->pktout
.data
[ssh
->pktout
.length
+ i
] = random_byte();
1485 PUT_32BIT(ssh
->pktout
.data
, ssh
->pktout
.length
+ padding
- 4);
1487 ssh
->csmac
->generate(ssh
->cs_mac_ctx
, ssh
->pktout
.data
,
1488 ssh
->pktout
.length
+ padding
,
1489 ssh
->v2_outgoing_sequence
);
1490 ssh
->v2_outgoing_sequence
++; /* whether or not we MACed */
1493 ssh
->cscipher
->encrypt(ssh
->cs_cipher_ctx
,
1494 ssh
->pktout
.data
, ssh
->pktout
.length
+ padding
);
1496 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1497 return ssh
->pktout
.length
+ padding
+ maclen
;
1501 * Construct and send an SSH2 packet immediately.
1503 static void ssh2_pkt_send(Ssh ssh
)
1507 len
= ssh2_pkt_construct(ssh
);
1508 backlog
= sk_write(ssh
->s
, (char *)ssh
->pktout
.data
, len
);
1509 if (backlog
> SSH_MAX_BACKLOG
)
1510 ssh_throttle_all(ssh
, 1, backlog
);
1514 * Construct an SSH2 packet and add it to a deferred data block.
1515 * Useful for sending multiple packets in a single sk_write() call,
1516 * to prevent a traffic-analysing listener from being able to work
1517 * out the length of any particular packet (such as the password
1520 * Note that because SSH2 sequence-numbers its packets, this can
1521 * NOT be used as an m4-style `defer' allowing packets to be
1522 * constructed in one order and sent in another.
1524 static void ssh2_pkt_defer(Ssh ssh
)
1526 int len
= ssh2_pkt_construct(ssh
);
1527 if (ssh
->deferred_len
+ len
> ssh
->deferred_size
) {
1528 ssh
->deferred_size
= ssh
->deferred_len
+ len
+ 128;
1529 ssh
->deferred_send_data
= srealloc(ssh
->deferred_send_data
,
1530 ssh
->deferred_size
);
1532 memcpy(ssh
->deferred_send_data
+ ssh
->deferred_len
, ssh
->pktout
.data
, len
);
1533 ssh
->deferred_len
+= len
;
1537 * Send the whole deferred data block constructed by
1538 * ssh2_pkt_defer() or SSH1's defer_packet().
1540 static void ssh_pkt_defersend(Ssh ssh
)
1543 backlog
= sk_write(ssh
->s
, (char *)ssh
->deferred_send_data
,
1545 ssh
->deferred_len
= ssh
->deferred_size
= 0;
1546 sfree(ssh
->deferred_send_data
);
1547 ssh
->deferred_send_data
= NULL
;
1548 if (backlog
> SSH_MAX_BACKLOG
)
1549 ssh_throttle_all(ssh
, 1, backlog
);
1553 void bndebug(char *string
, Bignum b
)
1557 p
= ssh2_mpint_fmt(b
, &len
);
1558 debug(("%s", string
));
1559 for (i
= 0; i
< len
; i
++)
1560 debug((" %02x", p
[i
]));
1566 static void sha_mpint(SHA_State
* s
, Bignum b
)
1570 p
= ssh2_mpint_fmt(b
, &len
);
1571 sha_string(s
, p
, len
);
1576 * SSH2 packet decode functions.
1578 static unsigned long ssh2_pkt_getuint32(Ssh ssh
)
1580 unsigned long value
;
1581 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< 4)
1582 return 0; /* arrgh, no way to decline (FIXME?) */
1583 value
= GET_32BIT(ssh
->pktin
.data
+ ssh
->pktin
.savedpos
);
1584 ssh
->pktin
.savedpos
+= 4;
1587 static int ssh2_pkt_getbool(Ssh ssh
)
1589 unsigned long value
;
1590 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< 1)
1591 return 0; /* arrgh, no way to decline (FIXME?) */
1592 value
= ssh
->pktin
.data
[ssh
->pktin
.savedpos
] != 0;
1593 ssh
->pktin
.savedpos
++;
1596 static void ssh2_pkt_getstring(Ssh ssh
, char **p
, int *length
)
1601 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< 4)
1603 len
= GET_32BIT(ssh
->pktin
.data
+ ssh
->pktin
.savedpos
);
1607 ssh
->pktin
.savedpos
+= 4;
1608 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< *length
)
1610 *p
= (char *)(ssh
->pktin
.data
+ ssh
->pktin
.savedpos
);
1611 ssh
->pktin
.savedpos
+= *length
;
1613 static Bignum
ssh2_pkt_getmp(Ssh ssh
)
1619 ssh2_pkt_getstring(ssh
, &p
, &length
);
1623 bombout((ssh
,"internal error: Can't handle negative mpints"));
1626 b
= bignum_from_bytes((unsigned char *)p
, length
);
1631 * Helper function to add an SSH2 signature blob to a packet.
1632 * Expects to be shown the public key blob as well as the signature
1633 * blob. Normally works just like ssh2_pkt_addstring, but will
1634 * fiddle with the signature packet if necessary for
1635 * BUG_SSH2_RSA_PADDING.
1637 static void ssh2_add_sigblob(Ssh ssh
, void *pkblob_v
, int pkblob_len
,
1638 void *sigblob_v
, int sigblob_len
)
1640 unsigned char *pkblob
= (unsigned char *)pkblob_v
;
1641 unsigned char *sigblob
= (unsigned char *)sigblob_v
;
1643 /* dmemdump(pkblob, pkblob_len); */
1644 /* dmemdump(sigblob, sigblob_len); */
1647 * See if this is in fact an ssh-rsa signature and a buggy
1648 * server; otherwise we can just do this the easy way.
1650 if ((ssh
->remote_bugs
& BUG_SSH2_RSA_PADDING
) &&
1651 (GET_32BIT(pkblob
) == 7 && !memcmp(pkblob
+4, "ssh-rsa", 7))) {
1652 int pos
, len
, siglen
;
1655 * Find the byte length of the modulus.
1658 pos
= 4+7; /* skip over "ssh-rsa" */
1659 pos
+= 4 + GET_32BIT(pkblob
+pos
); /* skip over exponent */
1660 len
= GET_32BIT(pkblob
+pos
); /* find length of modulus */
1661 pos
+= 4; /* find modulus itself */
1662 while (len
> 0 && pkblob
[pos
] == 0)
1664 /* debug(("modulus length is %d\n", len)); */
1667 * Now find the signature integer.
1669 pos
= 4+7; /* skip over "ssh-rsa" */
1670 siglen
= GET_32BIT(sigblob
+pos
);
1671 /* debug(("signature length is %d\n", siglen)); */
1673 if (len
!= siglen
) {
1674 unsigned char newlen
[4];
1675 ssh2_pkt_addstring_start(ssh
);
1676 ssh2_pkt_addstring_data(ssh
, (char *)sigblob
, pos
);
1677 /* dmemdump(sigblob, pos); */
1678 pos
+= 4; /* point to start of actual sig */
1679 PUT_32BIT(newlen
, len
);
1680 ssh2_pkt_addstring_data(ssh
, (char *)newlen
, 4);
1681 /* dmemdump(newlen, 4); */
1683 while (len
-- > siglen
) {
1684 ssh2_pkt_addstring_data(ssh
, (char *)newlen
, 1);
1685 /* dmemdump(newlen, 1); */
1687 ssh2_pkt_addstring_data(ssh
, (char *)(sigblob
+pos
), siglen
);
1688 /* dmemdump(sigblob+pos, siglen); */
1692 /* Otherwise fall through and do it the easy way. */
1695 ssh2_pkt_addstring_start(ssh
);
1696 ssh2_pkt_addstring_data(ssh
, (char *)sigblob
, sigblob_len
);
1700 * Examine the remote side's version string and compare it against
1701 * a list of known buggy implementations.
1703 static void ssh_detect_bugs(Ssh ssh
, char *vstring
)
1705 char *imp
; /* pointer to implementation part */
1707 imp
+= strcspn(imp
, "-");
1709 imp
+= strcspn(imp
, "-");
1712 ssh
->remote_bugs
= 0;
1714 if (cfg
.sshbug_ignore1
== BUG_ON
||
1715 (cfg
.sshbug_ignore1
== BUG_AUTO
&&
1716 (!strcmp(imp
, "1.2.18") || !strcmp(imp
, "1.2.19") ||
1717 !strcmp(imp
, "1.2.20") || !strcmp(imp
, "1.2.21") ||
1718 !strcmp(imp
, "1.2.22") || !strcmp(imp
, "Cisco-1.25")))) {
1720 * These versions don't support SSH1_MSG_IGNORE, so we have
1721 * to use a different defence against password length
1724 ssh
->remote_bugs
|= BUG_CHOKES_ON_SSH1_IGNORE
;
1725 logevent("We believe remote version has SSH1 ignore bug");
1728 if (cfg
.sshbug_plainpw1
== BUG_ON
||
1729 (cfg
.sshbug_plainpw1
== BUG_AUTO
&&
1730 (!strcmp(imp
, "Cisco-1.25")))) {
1732 * These versions need a plain password sent; they can't
1733 * handle having a null and a random length of data after
1736 ssh
->remote_bugs
|= BUG_NEEDS_SSH1_PLAIN_PASSWORD
;
1737 logevent("We believe remote version needs a plain SSH1 password");
1740 if (cfg
.sshbug_rsa1
== BUG_ON
||
1741 (cfg
.sshbug_rsa1
== BUG_AUTO
&&
1742 (!strcmp(imp
, "Cisco-1.25")))) {
1744 * These versions apparently have no clue whatever about
1745 * RSA authentication and will panic and die if they see
1746 * an AUTH_RSA message.
1748 ssh
->remote_bugs
|= BUG_CHOKES_ON_RSA
;
1749 logevent("We believe remote version can't handle RSA authentication");
1752 if (cfg
.sshbug_hmac2
== BUG_ON
||
1753 (cfg
.sshbug_hmac2
== BUG_AUTO
&&
1754 (wc_match("2.1.0*", imp
) || wc_match("2.0.*", imp
) ||
1755 wc_match("2.2.0*", imp
) || wc_match("2.3.0*", imp
) ||
1756 wc_match("2.1 *", imp
)))) {
1758 * These versions have the HMAC bug.
1760 ssh
->remote_bugs
|= BUG_SSH2_HMAC
;
1761 logevent("We believe remote version has SSH2 HMAC bug");
1764 if (cfg
.sshbug_derivekey2
== BUG_ON
||
1765 (cfg
.sshbug_derivekey2
== BUG_AUTO
&&
1766 (wc_match("2.0.0*", imp
) || wc_match("2.0.1[01]*", imp
) ))) {
1768 * These versions have the key-derivation bug (failing to
1769 * include the literal shared secret in the hashes that
1770 * generate the keys).
1772 ssh
->remote_bugs
|= BUG_SSH2_DERIVEKEY
;
1773 logevent("We believe remote version has SSH2 key-derivation bug");
1776 if (cfg
.sshbug_rsapad2
== BUG_ON
||
1777 (cfg
.sshbug_rsapad2
== BUG_AUTO
&&
1778 (wc_match("OpenSSH_2.[5-9]*", imp
) ||
1779 wc_match("OpenSSH_3.[0-2]*", imp
)))) {
1781 * These versions have the SSH2 RSA padding bug.
1783 ssh
->remote_bugs
|= BUG_SSH2_RSA_PADDING
;
1784 logevent("We believe remote version has SSH2 RSA padding bug");
1787 if (cfg
.sshbug_dhgex2
== BUG_ON
) {
1789 * User specified the SSH2 DH GEX bug.
1791 ssh
->remote_bugs
|= BUG_SSH2_DH_GEX
;
1792 logevent("We believe remote version has SSH2 DH group exchange bug");
1796 static int do_ssh_init(Ssh ssh
, unsigned char c
)
1798 struct do_ssh_init_state
{
1806 crState(do_ssh_init_state
);
1808 crBegin(ssh
->do_ssh_init_crstate
);
1810 /* Search for the string "SSH-" in the input. */
1813 static const int transS
[] = { 1, 2, 2, 1 };
1814 static const int transH
[] = { 0, 0, 3, 0 };
1815 static const int transminus
[] = { 0, 0, 0, -1 };
1817 s
->i
= transS
[s
->i
];
1819 s
->i
= transH
[s
->i
];
1821 s
->i
= transminus
[s
->i
];
1826 crReturn(1); /* get another character */
1830 s
->vstring
= smalloc(s
->vstrsize
);
1831 strcpy(s
->vstring
, "SSH-");
1835 crReturn(1); /* get another char */
1836 if (s
->vslen
>= s
->vstrsize
- 1) {
1838 s
->vstring
= srealloc(s
->vstring
, s
->vstrsize
);
1840 s
->vstring
[s
->vslen
++] = c
;
1843 s
->version
[s
->i
] = '\0';
1845 } else if (s
->i
< sizeof(s
->version
) - 1)
1846 s
->version
[s
->i
++] = c
;
1847 } else if (c
== '\012')
1851 ssh
->agentfwd_enabled
= FALSE
;
1852 ssh
->rdpkt2_state
.incoming_sequence
= 0;
1854 s
->vstring
[s
->vslen
] = 0;
1855 s
->vstring
[strcspn(s
->vstring
, "\r\n")] = '\0';/* remove EOL chars */
1858 vlog
= smalloc(20 + s
->vslen
);
1859 sprintf(vlog
, "Server version: %s", s
->vstring
);
1863 ssh_detect_bugs(ssh
, s
->vstring
);
1866 * Decide which SSH protocol version to support.
1869 /* Anything strictly below "2.0" means protocol 1 is supported. */
1870 s
->proto1
= ssh_versioncmp(s
->version
, "2.0") < 0;
1871 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
1872 s
->proto2
= ssh_versioncmp(s
->version
, "1.99") >= 0;
1874 if (cfg
.sshprot
== 0 && !s
->proto1
) {
1875 bombout((ssh
,"SSH protocol version 1 required by user but not provided by server"));
1878 if (cfg
.sshprot
== 3 && !s
->proto2
) {
1879 bombout((ssh
,"SSH protocol version 2 required by user but not provided by server"));
1883 if (s
->proto2
&& (cfg
.sshprot
>= 2 || !s
->proto1
)) {
1887 char verstring
[80], vlog
[100];
1888 sprintf(verstring
, "SSH-2.0-%s", sshver
);
1889 SHA_Init(&ssh
->exhashbase
);
1891 * Hash our version string and their version string.
1893 sha_string(&ssh
->exhashbase
, verstring
, strlen(verstring
));
1894 sha_string(&ssh
->exhashbase
, s
->vstring
, strcspn(s
->vstring
, "\r\n"));
1895 sprintf(vlog
, "We claim version: %s", verstring
);
1897 strcat(verstring
, "\012");
1898 logevent("Using SSH protocol version 2");
1899 sk_write(ssh
->s
, verstring
, strlen(verstring
));
1900 ssh
->protocol
= ssh2_protocol
;
1902 ssh
->s_rdpkt
= ssh2_rdpkt
;
1907 char verstring
[80], vlog
[100];
1908 sprintf(verstring
, "SSH-%s-%s",
1909 (ssh_versioncmp(s
->version
, "1.5") <= 0 ? s
->version
: "1.5"),
1911 sprintf(vlog
, "We claim version: %s", verstring
);
1913 strcat(verstring
, "\012");
1915 logevent("Using SSH protocol version 1");
1916 sk_write(ssh
->s
, verstring
, strlen(verstring
));
1917 ssh
->protocol
= ssh1_protocol
;
1919 ssh
->s_rdpkt
= ssh1_rdpkt
;
1921 ssh
->state
= SSH_STATE_BEFORE_SIZE
;
1928 static void ssh_gotdata(Ssh ssh
, unsigned char *data
, int datalen
)
1930 crBegin(ssh
->ssh_gotdata_crstate
);
1933 * To begin with, feed the characters one by one to the
1934 * protocol initialisation / selection function do_ssh_init().
1935 * When that returns 0, we're done with the initial greeting
1936 * exchange and can move on to packet discipline.
1939 int ret
; /* need not be kept across crReturn */
1941 crReturnV
; /* more data please */
1942 ret
= do_ssh_init(ssh
, *data
);
1950 * We emerge from that loop when the initial negotiation is
1951 * over and we have selected an s_rdpkt function. Now pass
1952 * everything to s_rdpkt, and then pass the resulting packets
1953 * to the proper protocol handler.
1958 while (datalen
> 0) {
1959 if (ssh
->s_rdpkt(ssh
, &data
, &datalen
) == 0) {
1960 if (ssh
->state
== SSH_STATE_CLOSED
) {
1963 ssh
->protocol(ssh
, NULL
, 0, 1);
1964 if (ssh
->state
== SSH_STATE_CLOSED
) {
1974 static int ssh_closing(Plug plug
, char *error_msg
, int error_code
,
1977 Ssh ssh
= (Ssh
) plug
;
1978 ssh
->state
= SSH_STATE_CLOSED
;
1984 /* A socket error has occurred. */
1985 logevent(error_msg
);
1986 connection_fatal(ssh
->frontend
, error_msg
);
1988 /* Otherwise, the remote side closed the connection normally. */
1993 static int ssh_receive(Plug plug
, int urgent
, char *data
, int len
)
1995 Ssh ssh
= (Ssh
) plug
;
1996 ssh_gotdata(ssh
, (unsigned char *)data
, len
);
1997 if (ssh
->state
== SSH_STATE_CLOSED
) {
2007 static void ssh_sent(Plug plug
, int bufsize
)
2009 Ssh ssh
= (Ssh
) plug
;
2011 * If the send backlog on the SSH socket itself clears, we
2012 * should unthrottle the whole world if it was throttled.
2014 if (bufsize
< SSH_MAX_BACKLOG
)
2015 ssh_throttle_all(ssh
, 0, bufsize
);
2019 * Connect to specified host and port.
2020 * Returns an error message, or NULL on success.
2021 * Also places the canonical host name into `realhost'. It must be
2022 * freed by the caller.
2024 static char *connect_to_host(Ssh ssh
, char *host
, int port
,
2025 char **realhost
, int nodelay
)
2027 static const struct plug_function_table fn_table
= {
2037 ssh
->savedhost
= smalloc(1 + strlen(host
));
2038 if (!ssh
->savedhost
)
2039 fatalbox("Out of memory");
2040 strcpy(ssh
->savedhost
, host
);
2043 port
= 22; /* default ssh port */
2044 ssh
->savedport
= port
;
2049 logeventf(ssh
, "Looking up host \"%s\"", host
);
2050 addr
= name_lookup(host
, port
, realhost
);
2051 if ((err
= sk_addr_error(addr
)) != NULL
)
2059 sk_getaddr(addr
, addrbuf
, 100);
2060 logeventf(ssh
, "Connecting to %s port %d", addrbuf
, port
);
2062 ssh
->fn
= &fn_table
;
2063 ssh
->s
= new_connection(addr
, *realhost
, port
, 0, 1, nodelay
, (Plug
) ssh
);
2064 if ((err
= sk_socket_error(ssh
->s
)) != NULL
) {
2073 * Throttle or unthrottle the SSH connection.
2075 static void ssh1_throttle(Ssh ssh
, int adjust
)
2077 int old_count
= ssh
->v1_throttle_count
;
2078 ssh
->v1_throttle_count
+= adjust
;
2079 assert(ssh
->v1_throttle_count
>= 0);
2080 if (ssh
->v1_throttle_count
&& !old_count
) {
2081 sk_set_frozen(ssh
->s
, 1);
2082 } else if (!ssh
->v1_throttle_count
&& old_count
) {
2083 sk_set_frozen(ssh
->s
, 0);
2088 * Throttle or unthrottle _all_ local data streams (for when sends
2089 * on the SSH connection itself back up).
2091 static void ssh_throttle_all(Ssh ssh
, int enable
, int bufsize
)
2094 struct ssh_channel
*c
;
2096 if (enable
== ssh
->throttled_all
)
2098 ssh
->throttled_all
= enable
;
2099 ssh
->overall_bufsize
= bufsize
;
2102 for (i
= 0; NULL
!= (c
= index234(ssh
->channels
, i
)); i
++) {
2104 case CHAN_MAINSESSION
:
2106 * This is treated separately, outside the switch.
2110 x11_override_throttle(c
->u
.x11
.s
, enable
);
2113 /* Agent channels require no buffer management. */
2116 pfd_override_throttle(c
->u
.x11
.s
, enable
);
2123 * Username and password input, abstracted off into routines
2124 * reusable in several places - even between SSH1 and SSH2.
2127 /* Set up a username or password input loop on a given buffer. */
2128 static void setup_userpass_input(Ssh ssh
, char *buffer
, int buflen
, int echo
)
2130 ssh
->userpass_input_buffer
= buffer
;
2131 ssh
->userpass_input_buflen
= buflen
;
2132 ssh
->userpass_input_bufpos
= 0;
2133 ssh
->userpass_input_echo
= echo
;
2137 * Process some terminal data in the course of username/password
2138 * input. Returns >0 for success (line of input returned in
2139 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2140 * for inconclusive (keep waiting for more input please).
2142 static int process_userpass_input(Ssh ssh
, unsigned char *in
, int inlen
)
2147 switch (c
= *in
++) {
2150 ssh
->userpass_input_buffer
[ssh
->userpass_input_bufpos
] = 0;
2151 ssh
->userpass_input_buffer
[ssh
->userpass_input_buflen
-1] = 0;
2156 if (ssh
->userpass_input_bufpos
> 0) {
2157 if (ssh
->userpass_input_echo
)
2158 c_write_str(ssh
, "\b \b");
2159 ssh
->userpass_input_bufpos
--;
2164 while (ssh
->userpass_input_bufpos
> 0) {
2165 if (ssh
->userpass_input_echo
)
2166 c_write_str(ssh
, "\b \b");
2167 ssh
->userpass_input_bufpos
--;
2175 if (((c
>= ' ' && c
<= '~') ||
2176 ((unsigned char) c
>= 160))
2177 && ssh
->userpass_input_bufpos
< ssh
->userpass_input_buflen
-1) {
2178 ssh
->userpass_input_buffer
[ssh
->userpass_input_bufpos
++] = c
;
2179 if (ssh
->userpass_input_echo
)
2180 c_write(ssh
, &c
, 1);
2189 * Handle the key exchange and user authentication phases.
2191 static int do_ssh1_login(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
2194 unsigned char cookie
[8];
2195 struct RSAKey servkey
, hostkey
;
2196 struct MD5Context md5c
;
2197 struct do_ssh1_login_state
{
2199 unsigned char *rsabuf
, *keystr1
, *keystr2
;
2200 unsigned long supported_ciphers_mask
, supported_auths_mask
;
2201 int tried_publickey
, tried_agent
;
2202 int tis_auth_refused
, ccard_auth_refused
;
2203 unsigned char session_id
[16];
2206 void *publickey_blob
;
2207 int publickey_bloblen
;
2213 unsigned char request
[5], *response
, *p
;
2222 crState(do_ssh1_login_state
);
2224 crBegin(ssh
->do_ssh1_login_crstate
);
2229 if (ssh
->pktin
.type
!= SSH1_SMSG_PUBLIC_KEY
) {
2230 bombout((ssh
,"Public key packet not received"));
2234 logevent("Received public keys");
2236 memcpy(cookie
, ssh
->pktin
.body
, 8);
2238 i
= makekey(ssh
->pktin
.body
+ 8, &servkey
, &s
->keystr1
, 0);
2239 j
= makekey(ssh
->pktin
.body
+ 8 + i
, &hostkey
, &s
->keystr2
, 0);
2242 * Log the host key fingerprint.
2246 logevent("Host key fingerprint is:");
2247 strcpy(logmsg
, " ");
2248 hostkey
.comment
= NULL
;
2249 rsa_fingerprint(logmsg
+ strlen(logmsg
),
2250 sizeof(logmsg
) - strlen(logmsg
), &hostkey
);
2254 ssh
->v1_remote_protoflags
= GET_32BIT(ssh
->pktin
.body
+ 8 + i
+ j
);
2255 s
->supported_ciphers_mask
= GET_32BIT(ssh
->pktin
.body
+ 12 + i
+ j
);
2256 s
->supported_auths_mask
= GET_32BIT(ssh
->pktin
.body
+ 16 + i
+ j
);
2258 ssh
->v1_local_protoflags
=
2259 ssh
->v1_remote_protoflags
& SSH1_PROTOFLAGS_SUPPORTED
;
2260 ssh
->v1_local_protoflags
|= SSH1_PROTOFLAG_SCREEN_NUMBER
;
2263 MD5Update(&md5c
, s
->keystr2
, hostkey
.bytes
);
2264 MD5Update(&md5c
, s
->keystr1
, servkey
.bytes
);
2265 MD5Update(&md5c
, ssh
->pktin
.body
, 8);
2266 MD5Final(s
->session_id
, &md5c
);
2268 for (i
= 0; i
< 32; i
++)
2269 ssh
->session_key
[i
] = random_byte();
2271 s
->len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
2273 s
->rsabuf
= smalloc(s
->len
);
2275 fatalbox("Out of memory");
2278 * Verify the host key.
2282 * First format the key into a string.
2284 int len
= rsastr_len(&hostkey
);
2285 char fingerprint
[100];
2286 char *keystr
= smalloc(len
);
2288 fatalbox("Out of memory");
2289 rsastr_fmt(keystr
, &hostkey
);
2290 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
2291 verify_ssh_host_key(ssh
->frontend
,
2292 ssh
->savedhost
, ssh
->savedport
, "rsa", keystr
,
2297 for (i
= 0; i
< 32; i
++) {
2298 s
->rsabuf
[i
] = ssh
->session_key
[i
];
2300 s
->rsabuf
[i
] ^= s
->session_id
[i
];
2303 if (hostkey
.bytes
> servkey
.bytes
) {
2304 rsaencrypt(s
->rsabuf
, 32, &servkey
);
2305 rsaencrypt(s
->rsabuf
, servkey
.bytes
, &hostkey
);
2307 rsaencrypt(s
->rsabuf
, 32, &hostkey
);
2308 rsaencrypt(s
->rsabuf
, hostkey
.bytes
, &servkey
);
2311 logevent("Encrypted session key");
2314 int cipher_chosen
= 0, warn
= 0;
2315 char *cipher_string
= NULL
;
2317 for (i
= 0; !cipher_chosen
&& i
< CIPHER_MAX
; i
++) {
2318 int next_cipher
= cfg
.ssh_cipherlist
[i
];
2319 if (next_cipher
== CIPHER_WARN
) {
2320 /* If/when we choose a cipher, warn about it */
2322 } else if (next_cipher
== CIPHER_AES
) {
2323 /* XXX Probably don't need to mention this. */
2324 logevent("AES not supported in SSH1, skipping");
2326 switch (next_cipher
) {
2327 case CIPHER_3DES
: s
->cipher_type
= SSH_CIPHER_3DES
;
2328 cipher_string
= "3DES"; break;
2329 case CIPHER_BLOWFISH
: s
->cipher_type
= SSH_CIPHER_BLOWFISH
;
2330 cipher_string
= "Blowfish"; break;
2331 case CIPHER_DES
: s
->cipher_type
= SSH_CIPHER_DES
;
2332 cipher_string
= "single-DES"; break;
2334 if (s
->supported_ciphers_mask
& (1 << s
->cipher_type
))
2338 if (!cipher_chosen
) {
2339 if ((s
->supported_ciphers_mask
& (1 << SSH_CIPHER_3DES
)) == 0)
2340 bombout((ssh
,"Server violates SSH 1 protocol by not "
2341 "supporting 3DES encryption"));
2343 /* shouldn't happen */
2344 bombout((ssh
,"No supported ciphers found"));
2348 /* Warn about chosen cipher if necessary. */
2350 askcipher(ssh
->frontend
, cipher_string
, 0);
2353 switch (s
->cipher_type
) {
2354 case SSH_CIPHER_3DES
:
2355 logevent("Using 3DES encryption");
2357 case SSH_CIPHER_DES
:
2358 logevent("Using single-DES encryption");
2360 case SSH_CIPHER_BLOWFISH
:
2361 logevent("Using Blowfish encryption");
2365 send_packet(ssh
, SSH1_CMSG_SESSION_KEY
,
2366 PKT_CHAR
, s
->cipher_type
,
2367 PKT_DATA
, cookie
, 8,
2368 PKT_CHAR
, (s
->len
* 8) >> 8, PKT_CHAR
, (s
->len
* 8) & 0xFF,
2369 PKT_DATA
, s
->rsabuf
, s
->len
,
2370 PKT_INT
, ssh
->v1_local_protoflags
, PKT_END
);
2372 logevent("Trying to enable encryption...");
2376 ssh
->cipher
= (s
->cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
2377 s
->cipher_type
== SSH_CIPHER_DES ?
&ssh_des
:
2379 ssh
->v1_cipher_ctx
= ssh
->cipher
->make_context();
2380 ssh
->cipher
->sesskey(ssh
->v1_cipher_ctx
, ssh
->session_key
);
2381 logeventf(ssh
, "Initialised %s encryption", ssh
->cipher
->text_name
);
2383 ssh
->crcda_ctx
= crcda_make_context();
2384 logevent("Installing CRC compensation attack detector");
2388 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2389 bombout((ssh
,"Encryption not successfully enabled"));
2393 logevent("Successfully started encryption");
2397 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
2398 if (ssh_get_line
&& !ssh_getline_pw_only
) {
2399 if (!ssh_get_line("login as: ",
2400 s
->username
, sizeof(s
->username
), FALSE
)) {
2402 * get_line failed to get a username.
2405 logevent("No username provided. Abandoning session.");
2406 ssh
->state
= SSH_STATE_CLOSED
;
2410 int ret
; /* need not be kept over crReturn */
2411 c_write_str(ssh
, "login as: ");
2414 setup_userpass_input(ssh
, s
->username
, sizeof(s
->username
), 1);
2416 crWaitUntil(!ispkt
);
2417 ret
= process_userpass_input(ssh
, in
, inlen
);
2421 c_write_str(ssh
, "\r\n");
2424 strncpy(s
->username
, cfg
.username
, sizeof(s
->username
));
2425 s
->username
[sizeof(s
->username
)-1] = '\0';
2428 send_packet(ssh
, SSH1_CMSG_USER
, PKT_STR
, s
->username
, PKT_END
);
2430 char userlog
[22 + sizeof(s
->username
)];
2431 sprintf(userlog
, "Sent username \"%s\"", s
->username
);
2433 if (flags
& FLAG_INTERACTIVE
&&
2434 (!((flags
& FLAG_STDERR
) && (flags
& FLAG_VERBOSE
)))) {
2435 strcat(userlog
, "\r\n");
2436 c_write_str(ssh
, userlog
);
2443 if ((ssh
->remote_bugs
& BUG_CHOKES_ON_RSA
)) {
2444 /* We must not attempt PK auth. Pretend we've already tried it. */
2445 s
->tried_publickey
= s
->tried_agent
= 1;
2447 s
->tried_publickey
= s
->tried_agent
= 0;
2449 s
->tis_auth_refused
= s
->ccard_auth_refused
= 0;
2450 /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
2452 if (!rsakey_pubblob(cfg
.keyfile
,
2453 &s
->publickey_blob
, &s
->publickey_bloblen
))
2454 s
->publickey_blob
= NULL
;
2456 s
->publickey_blob
= NULL
;
2458 while (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2459 s
->pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
2461 if (agent_exists() && !s
->tried_agent
) {
2463 * Attempt RSA authentication using Pageant.
2469 logevent("Pageant is running. Requesting keys.");
2471 /* Request the keys held by the agent. */
2472 PUT_32BIT(s
->request
, 1);
2473 s
->request
[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES
;
2474 agent_query(s
->request
, 5, &r
, &s
->responselen
);
2475 s
->response
= (unsigned char *) r
;
2476 if (s
->response
&& s
->responselen
>= 5 &&
2477 s
->response
[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER
) {
2478 s
->p
= s
->response
+ 5;
2479 s
->nkeys
= GET_32BIT(s
->p
);
2483 sprintf(buf
, "Pageant has %d SSH1 keys", s
->nkeys
);
2486 for (s
->keyi
= 0; s
->keyi
< s
->nkeys
; s
->keyi
++) {
2489 sprintf(buf
, "Trying Pageant key #%d", s
->keyi
);
2492 if (s
->publickey_blob
&&
2493 !memcmp(s
->p
, s
->publickey_blob
,
2494 s
->publickey_bloblen
)) {
2495 logevent("This key matches configured key file");
2496 s
->tried_publickey
= 1;
2499 s
->p
+= ssh1_read_bignum(s
->p
, &s
->key
.exponent
);
2500 s
->p
+= ssh1_read_bignum(s
->p
, &s
->key
.modulus
);
2501 s
->commentlen
= GET_32BIT(s
->p
);
2503 s
->commentp
= (char *)s
->p
;
2504 s
->p
+= s
->commentlen
;
2505 send_packet(ssh
, SSH1_CMSG_AUTH_RSA
,
2506 PKT_BIGNUM
, s
->key
.modulus
, PKT_END
);
2508 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2509 logevent("Key refused");
2512 logevent("Received RSA challenge");
2513 ssh1_read_bignum(ssh
->pktin
.body
, &s
->challenge
);
2515 char *agentreq
, *q
, *ret
;
2518 len
= 1 + 4; /* message type, bit count */
2519 len
+= ssh1_bignum_length(s
->key
.exponent
);
2520 len
+= ssh1_bignum_length(s
->key
.modulus
);
2521 len
+= ssh1_bignum_length(s
->challenge
);
2522 len
+= 16; /* session id */
2523 len
+= 4; /* response format */
2524 agentreq
= smalloc(4 + len
);
2525 PUT_32BIT(agentreq
, len
);
2527 *q
++ = SSH1_AGENTC_RSA_CHALLENGE
;
2528 PUT_32BIT(q
, bignum_bitcount(s
->key
.modulus
));
2530 q
+= ssh1_write_bignum(q
, s
->key
.exponent
);
2531 q
+= ssh1_write_bignum(q
, s
->key
.modulus
);
2532 q
+= ssh1_write_bignum(q
, s
->challenge
);
2533 memcpy(q
, s
->session_id
, 16);
2535 PUT_32BIT(q
, 1); /* response format */
2536 agent_query(agentreq
, len
+ 4, &vret
, &retlen
);
2540 if (ret
[4] == SSH1_AGENT_RSA_RESPONSE
) {
2541 logevent("Sending Pageant's response");
2542 send_packet(ssh
, SSH1_CMSG_AUTH_RSA_RESPONSE
,
2543 PKT_DATA
, ret
+ 5, 16,
2547 if (ssh
->pktin
.type
== SSH1_SMSG_SUCCESS
) {
2549 ("Pageant's response accepted");
2550 if (flags
& FLAG_VERBOSE
) {
2551 c_write_str(ssh
, "Authenticated using"
2553 c_write(ssh
, s
->commentp
,
2555 c_write_str(ssh
, "\" from agent\r\n");
2560 ("Pageant's response not accepted");
2563 ("Pageant failed to answer challenge");
2567 logevent("No reply received from Pageant");
2570 freebn(s
->key
.exponent
);
2571 freebn(s
->key
.modulus
);
2572 freebn(s
->challenge
);
2580 if (*cfg
.keyfile
&& !s
->tried_publickey
)
2581 s
->pwpkt_type
= SSH1_CMSG_AUTH_RSA
;
2583 if (cfg
.try_tis_auth
&&
2584 (s
->supported_auths_mask
& (1 << SSH1_AUTH_TIS
)) &&
2585 !s
->tis_auth_refused
) {
2586 s
->pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
2587 logevent("Requested TIS authentication");
2588 send_packet(ssh
, SSH1_CMSG_AUTH_TIS
, PKT_END
);
2590 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
2591 logevent("TIS authentication declined");
2592 if (flags
& FLAG_INTERACTIVE
)
2593 c_write_str(ssh
, "TIS authentication refused.\r\n");
2594 s
->tis_auth_refused
= 1;
2597 int challengelen
= GET_32BIT(ssh
->pktin
.body
);
2598 logevent("Received TIS challenge");
2599 if (challengelen
> sizeof(s
->prompt
) - 1)
2600 challengelen
= sizeof(s
->prompt
) - 1;/* prevent overrun */
2601 memcpy(s
->prompt
, ssh
->pktin
.body
+ 4, challengelen
);
2602 /* Prompt heuristic comes from OpenSSH */
2603 strncpy(s
->prompt
+ challengelen
,
2604 memchr(s
->prompt
, '\n', challengelen
) ?
2605 "": "\r\nResponse: ",
2606 (sizeof s
->prompt
) - challengelen
);
2607 s
->prompt
[(sizeof s
->prompt
) - 1] = '\0';
2610 if (cfg
.try_tis_auth
&&
2611 (s
->supported_auths_mask
& (1 << SSH1_AUTH_CCARD
)) &&
2612 !s
->ccard_auth_refused
) {
2613 s
->pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
2614 logevent("Requested CryptoCard authentication");
2615 send_packet(ssh
, SSH1_CMSG_AUTH_CCARD
, PKT_END
);
2617 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
2618 logevent("CryptoCard authentication declined");
2619 c_write_str(ssh
, "CryptoCard authentication refused.\r\n");
2620 s
->ccard_auth_refused
= 1;
2623 int challengelen
= GET_32BIT(ssh
->pktin
.body
);
2624 logevent("Received CryptoCard challenge");
2625 if (challengelen
> sizeof(s
->prompt
) - 1)
2626 challengelen
= sizeof(s
->prompt
) - 1;/* prevent overrun */
2627 memcpy(s
->prompt
, ssh
->pktin
.body
+ 4, challengelen
);
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 (s
->pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2636 sprintf(s
->prompt
, "%.90s@%.90s's password: ",
2637 s
->username
, ssh
->savedhost
);
2639 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2640 char *comment
= NULL
;
2643 if (flags
& FLAG_VERBOSE
)
2644 c_write_str(ssh
, "Trying public key authentication.\r\n");
2645 logeventf(ssh
, "Trying public key \"%s\"", cfg
.keyfile
);
2646 type
= key_type(cfg
.keyfile
);
2647 if (type
!= SSH_KEYTYPE_SSH1
) {
2648 sprintf(msgbuf
, "Key is of wrong type (%s)",
2649 key_type_to_str(type
));
2651 c_write_str(ssh
, msgbuf
);
2652 c_write_str(ssh
, "\r\n");
2653 s
->tried_publickey
= 1;
2656 if (!rsakey_encrypted(cfg
.keyfile
, &comment
)) {
2657 if (flags
& FLAG_VERBOSE
)
2658 c_write_str(ssh
, "No passphrase required.\r\n");
2661 sprintf(s
->prompt
, "Passphrase for key \"%.100s\": ", comment
);
2666 * Show password prompt, having first obtained it via a TIS
2667 * or CryptoCard exchange if we're doing TIS or CryptoCard
2671 if (!ssh_get_line(s
->prompt
, s
->password
,
2672 sizeof(s
->password
), TRUE
)) {
2674 * get_line failed to get a password (for example
2675 * because one was supplied on the command line
2676 * which has already failed to work). Terminate.
2678 send_packet(ssh
, SSH1_MSG_DISCONNECT
,
2679 PKT_STR
, "No more passwords available to try",
2681 logevent("Unable to authenticate");
2682 connection_fatal(ssh
->frontend
, "Unable to authenticate");
2683 ssh
->state
= SSH_STATE_CLOSED
;
2687 /* Prompt may have come from server. We've munged it a bit, so
2688 * we know it to be zero-terminated at least once. */
2689 int ret
; /* need not be saved over crReturn */
2690 c_write_untrusted(ssh
, s
->prompt
, strlen(s
->prompt
));
2693 setup_userpass_input(ssh
, s
->password
, sizeof(s
->password
), 0);
2695 crWaitUntil(!ispkt
);
2696 ret
= process_userpass_input(ssh
, in
, inlen
);
2700 c_write_str(ssh
, "\r\n");
2704 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2706 * Try public key authentication with the specified
2709 s
->tried_publickey
= 1;
2712 int ret
= loadrsakey(cfg
.keyfile
, &s
->key
, s
->password
);
2714 c_write_str(ssh
, "Couldn't load private key from ");
2715 c_write_str(ssh
, cfg
.keyfile
);
2716 c_write_str(ssh
, ".\r\n");
2717 continue; /* go and try password */
2720 c_write_str(ssh
, "Wrong passphrase.\r\n");
2721 s
->tried_publickey
= 0;
2722 continue; /* try again */
2727 * Send a public key attempt.
2729 send_packet(ssh
, SSH1_CMSG_AUTH_RSA
,
2730 PKT_BIGNUM
, s
->key
.modulus
, PKT_END
);
2733 if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2734 c_write_str(ssh
, "Server refused our public key.\r\n");
2735 continue; /* go and try password */
2737 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2738 bombout((ssh
,"Bizarre response to offer of public key"));
2744 unsigned char buffer
[32];
2745 Bignum challenge
, response
;
2747 ssh1_read_bignum(ssh
->pktin
.body
, &challenge
);
2748 response
= rsadecrypt(challenge
, &s
->key
);
2749 freebn(s
->key
.private_exponent
);/* burn the evidence */
2751 for (i
= 0; i
< 32; i
++) {
2752 buffer
[i
] = bignum_byte(response
, 31 - i
);
2756 MD5Update(&md5c
, buffer
, 32);
2757 MD5Update(&md5c
, s
->session_id
, 16);
2758 MD5Final(buffer
, &md5c
);
2760 send_packet(ssh
, SSH1_CMSG_AUTH_RSA_RESPONSE
,
2761 PKT_DATA
, buffer
, 16, PKT_END
);
2768 if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2769 if (flags
& FLAG_VERBOSE
)
2770 c_write_str(ssh
, "Failed to authenticate with"
2771 " our public key.\r\n");
2772 continue; /* go and try password */
2773 } else if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2774 bombout((ssh
,"Bizarre response to RSA authentication response"));
2778 break; /* we're through! */
2780 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2782 * Defence against traffic analysis: we send a
2783 * whole bunch of packets containing strings of
2784 * different lengths. One of these strings is the
2785 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2786 * The others are all random data in
2787 * SSH1_MSG_IGNORE packets. This way a passive
2788 * listener can't tell which is the password, and
2789 * hence can't deduce the password length.
2791 * Anybody with a password length greater than 16
2792 * bytes is going to have enough entropy in their
2793 * password that a listener won't find it _that_
2794 * much help to know how long it is. So what we'll
2797 * - if password length < 16, we send 15 packets
2798 * containing string lengths 1 through 15
2800 * - otherwise, we let N be the nearest multiple
2801 * of 8 below the password length, and send 8
2802 * packets containing string lengths N through
2803 * N+7. This won't obscure the order of
2804 * magnitude of the password length, but it will
2805 * introduce a bit of extra uncertainty.
2807 * A few servers (the old 1.2.18 through 1.2.22)
2808 * can't deal with SSH1_MSG_IGNORE. For these
2809 * servers, we need an alternative defence. We make
2810 * use of the fact that the password is interpreted
2811 * as a C string: so we can append a NUL, then some
2814 * One server (a Cisco one) can deal with neither
2815 * SSH1_MSG_IGNORE _nor_ a padded password string.
2816 * For this server we are left with no defences
2817 * against password length sniffing.
2819 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
)) {
2821 * The server can deal with SSH1_MSG_IGNORE, so
2822 * we can use the primary defence.
2824 int bottom
, top
, pwlen
, i
;
2827 pwlen
= strlen(s
->password
);
2829 bottom
= 0; /* zero length passwords are OK! :-) */
2832 bottom
= pwlen
& ~7;
2836 assert(pwlen
>= bottom
&& pwlen
<= top
);
2838 randomstr
= smalloc(top
+ 1);
2840 for (i
= bottom
; i
<= top
; i
++) {
2842 defer_packet(ssh
, s
->pwpkt_type
,
2843 PKT_STR
, s
->password
, PKT_END
);
2845 for (j
= 0; j
< i
; j
++) {
2847 randomstr
[j
] = random_byte();
2848 } while (randomstr
[j
] == '\0');
2850 randomstr
[i
] = '\0';
2851 defer_packet(ssh
, SSH1_MSG_IGNORE
,
2852 PKT_STR
, randomstr
, PKT_END
);
2855 logevent("Sending password with camouflage packets");
2856 ssh_pkt_defersend(ssh
);
2858 else if (!(ssh
->remote_bugs
& BUG_NEEDS_SSH1_PLAIN_PASSWORD
)) {
2860 * The server can't deal with SSH1_MSG_IGNORE
2861 * but can deal with padded passwords, so we
2862 * can use the secondary defence.
2868 len
= strlen(s
->password
);
2869 if (len
< sizeof(string
)) {
2871 strcpy(string
, s
->password
);
2872 len
++; /* cover the zero byte */
2873 while (len
< sizeof(string
)) {
2874 string
[len
++] = (char) random_byte();
2879 logevent("Sending length-padded password");
2880 send_packet(ssh
, s
->pwpkt_type
, PKT_INT
, len
,
2881 PKT_DATA
, ss
, len
, PKT_END
);
2884 * The server has _both_
2885 * BUG_CHOKES_ON_SSH1_IGNORE and
2886 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2887 * therefore nothing we can do.
2890 len
= strlen(s
->password
);
2891 logevent("Sending unpadded password");
2892 send_packet(ssh
, s
->pwpkt_type
, PKT_INT
, len
,
2893 PKT_DATA
, s
->password
, len
, PKT_END
);
2896 send_packet(ssh
, s
->pwpkt_type
, PKT_STR
, s
->password
, PKT_END
);
2899 logevent("Sent password");
2900 memset(s
->password
, 0, strlen(s
->password
));
2902 if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2903 if (flags
& FLAG_VERBOSE
)
2904 c_write_str(ssh
, "Access denied\r\n");
2905 logevent("Authentication refused");
2906 } else if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2907 bombout((ssh
,"Strange packet received, type %d", ssh
->pktin
.type
));
2912 logevent("Authentication successful");
2917 void sshfwd_close(struct ssh_channel
*c
)
2921 if (c
&& !c
->closes
) {
2923 * If the channel's remoteid is -1, we have sent
2924 * CHANNEL_OPEN for this channel, but it hasn't even been
2925 * acknowledged by the server. So we must set a close flag
2926 * on it now, and then when the server acks the channel
2927 * open, we can close it then.
2929 if (((int)c
->remoteid
) != -1) {
2930 if (ssh
->version
== 1) {
2931 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
2934 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_CLOSE
);
2935 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
2939 c
->closes
= 1; /* sent MSG_CLOSE */
2940 if (c
->type
== CHAN_X11
) {
2942 logevent("Forwarded X11 connection terminated");
2943 } else if (c
->type
== CHAN_SOCKDATA
||
2944 c
->type
== CHAN_SOCKDATA_DORMANT
) {
2946 logevent("Forwarded port closed");
2951 int sshfwd_write(struct ssh_channel
*c
, char *buf
, int len
)
2955 if (ssh
->version
== 1) {
2956 send_packet(ssh
, SSH1_MSG_CHANNEL_DATA
,
2957 PKT_INT
, c
->remoteid
,
2958 PKT_INT
, len
, PKT_DATA
, buf
, len
, PKT_END
);
2960 * In SSH1 we can return 0 here - implying that forwarded
2961 * connections are never individually throttled - because
2962 * the only circumstance that can cause throttling will be
2963 * the whole SSH connection backing up, in which case
2964 * _everything_ will be throttled as a whole.
2968 ssh2_add_channel_data(c
, buf
, len
);
2969 return ssh2_try_send(c
);
2973 void sshfwd_unthrottle(struct ssh_channel
*c
, int bufsize
)
2977 if (ssh
->version
== 1) {
2978 if (c
->v
.v1
.throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
2979 c
->v
.v1
.throttling
= 0;
2980 ssh1_throttle(ssh
, -1);
2983 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
2987 static void ssh1_protocol(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
2989 crBegin(ssh
->ssh1_protocol_crstate
);
2993 while (!do_ssh1_login(ssh
, in
, inlen
, ispkt
)) {
2996 if (ssh
->state
== SSH_STATE_CLOSED
)
2999 if (cfg
.agentfwd
&& agent_exists()) {
3000 logevent("Requesting agent forwarding");
3001 send_packet(ssh
, SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
3005 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3006 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3007 bombout((ssh
,"Protocol confusion"));
3009 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3010 logevent("Agent forwarding refused");
3012 logevent("Agent forwarding enabled");
3013 ssh
->agentfwd_enabled
= TRUE
;
3017 if (cfg
.x11_forward
) {
3018 char proto
[20], data
[64];
3019 logevent("Requesting X11 forwarding");
3020 ssh
->x11auth
= x11_invent_auth(proto
, sizeof(proto
),
3021 data
, sizeof(data
));
3022 x11_get_real_auth(ssh
->x11auth
, cfg
.x11_display
);
3023 if (ssh
->v1_local_protoflags
& SSH1_PROTOFLAG_SCREEN_NUMBER
) {
3024 send_packet(ssh
, SSH1_CMSG_X11_REQUEST_FORWARDING
,
3025 PKT_STR
, proto
, PKT_STR
, data
,
3026 PKT_INT
, x11_get_screen_number(cfg
.x11_display
),
3029 send_packet(ssh
, SSH1_CMSG_X11_REQUEST_FORWARDING
,
3030 PKT_STR
, proto
, PKT_STR
, data
, PKT_END
);
3035 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3036 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3037 bombout((ssh
,"Protocol confusion"));
3039 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3040 logevent("X11 forwarding refused");
3042 logevent("X11 forwarding enabled");
3043 ssh
->X11_fwd_enabled
= TRUE
;
3050 int sport
,dport
,sserv
,dserv
;
3051 char sports
[256], dports
[256], saddr
[256], host
[256];
3053 ssh
->rportfwds
= newtree234(ssh_rportcmp_ssh1
);
3054 /* Add port forwardings. */
3055 ssh
->portfwd_strptr
= cfg
.portfwd
;
3056 while (*ssh
->portfwd_strptr
) {
3057 type
= *ssh
->portfwd_strptr
++;
3060 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= '\t') {
3061 if (*ssh
->portfwd_strptr
== ':') {
3063 * We've seen a colon in the middle of the
3064 * source port number. This means that
3065 * everything we've seen until now is the
3066 * source _address_, so we'll move it into
3067 * saddr and start sports from the beginning
3070 ssh
->portfwd_strptr
++;
3072 strcpy(saddr
, sports
);
3075 if (n
< 255) sports
[n
++] = *ssh
->portfwd_strptr
++;
3078 if (*ssh
->portfwd_strptr
== '\t')
3079 ssh
->portfwd_strptr
++;
3081 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= ':') {
3082 if (n
< 255) host
[n
++] = *ssh
->portfwd_strptr
++;
3085 if (*ssh
->portfwd_strptr
== ':')
3086 ssh
->portfwd_strptr
++;
3088 while (*ssh
->portfwd_strptr
) {
3089 if (n
< 255) dports
[n
++] = *ssh
->portfwd_strptr
++;
3092 ssh
->portfwd_strptr
++;
3093 dport
= atoi(dports
);
3097 dport
= net_service_lookup(dports
);
3099 logeventf(ssh
, "Service lookup failed for"
3100 " destination port \"%s\"", dports
);
3103 sport
= atoi(sports
);
3107 sport
= net_service_lookup(sports
);
3109 logeventf(ssh
, "Service lookup failed for source"
3110 " port \"%s\"", sports
);
3113 if (sport
&& dport
) {
3115 pfd_addforward(host
, dport
, *saddr ? saddr
: NULL
,
3117 logeventf(ssh
, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3118 " forwarding to %s:%.*s%.*s%d%.*s",
3119 (int)(*saddr?
strlen(saddr
):0), *saddr?saddr
:NULL
,
3120 (int)(*saddr?
1:0), ":",
3121 (int)(sserv ?
strlen(sports
) : 0), sports
,
3122 sserv
, "(", sport
, sserv
, ")",
3124 (int)(dserv ?
strlen(dports
) : 0), dports
,
3125 dserv
, "(", dport
, dserv
, ")");
3127 struct ssh_rportfwd
*pf
;
3128 pf
= smalloc(sizeof(*pf
));
3129 strcpy(pf
->dhost
, host
);
3133 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
3136 if (add234(ssh
->rportfwds
, pf
) != pf
) {
3138 "Duplicate remote port forwarding to %s:%d",
3142 logeventf(ssh
, "Requesting remote port %.*s%.*s%d%.*s"
3143 " forward to %s:%.*s%.*s%d%.*s",
3144 (int)(sserv ?
strlen(sports
) : 0), sports
,
3145 sserv
, "(", sport
, sserv
, ")",
3147 (int)(dserv ?
strlen(dports
) : 0), dports
,
3148 dserv
, "(", dport
, dserv
, ")");
3149 send_packet(ssh
, SSH1_CMSG_PORT_FORWARD_REQUEST
,
3157 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3158 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3159 bombout((ssh
,"Protocol confusion"));
3161 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3162 c_write_str(ssh
, "Server refused port"
3165 logevent("Remote port forwarding enabled");
3173 send_packet(ssh
, SSH1_CMSG_REQUEST_PTY
,
3174 PKT_STR
, cfg
.termtype
,
3175 PKT_INT
, ssh
->term_height
,
3176 PKT_INT
, ssh
->term_width
,
3177 PKT_INT
, 0, PKT_INT
, 0, PKT_CHAR
, 0, PKT_END
);
3178 ssh
->state
= SSH_STATE_INTERMED
;
3182 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3183 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3184 bombout((ssh
,"Protocol confusion"));
3186 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3187 c_write_str(ssh
, "Server refused to allocate pty\r\n");
3188 ssh
->editing
= ssh
->echoing
= 1;
3190 logevent("Allocated pty");
3192 ssh
->editing
= ssh
->echoing
= 1;
3195 if (cfg
.compression
) {
3196 send_packet(ssh
, SSH1_CMSG_REQUEST_COMPRESSION
, PKT_INT
, 6, PKT_END
);
3200 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3201 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3202 bombout((ssh
,"Protocol confusion"));
3204 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3205 c_write_str(ssh
, "Server refused to compress\r\n");
3207 logevent("Started compression");
3208 ssh
->v1_compressing
= TRUE
;
3209 ssh
->cs_comp_ctx
= zlib_compress_init();
3210 logevent("Initialised zlib (RFC1950) compression");
3211 ssh
->sc_comp_ctx
= zlib_decompress_init();
3212 logevent("Initialised zlib (RFC1950) decompression");
3216 * Start the shell or command.
3218 * Special case: if the first-choice command is an SSH2
3219 * subsystem (hence not usable here) and the second choice
3220 * exists, we fall straight back to that.
3223 char *cmd
= cfg
.remote_cmd_ptr
;
3225 if (cfg
.ssh_subsys
&& cfg
.remote_cmd_ptr2
) {
3226 cmd
= cfg
.remote_cmd_ptr2
;
3227 ssh
->fallback_cmd
= TRUE
;
3230 send_packet(ssh
, SSH1_CMSG_EXEC_CMD
, PKT_STR
, cmd
, PKT_END
);
3232 send_packet(ssh
, SSH1_CMSG_EXEC_SHELL
, PKT_END
);
3233 logevent("Started session");
3236 ssh
->state
= SSH_STATE_SESSION
;
3237 if (ssh
->size_needed
)
3238 ssh_size(ssh
, ssh
->term_width
, ssh
->term_height
);
3239 if (ssh
->eof_needed
)
3240 ssh_special(ssh
, TS_EOF
);
3243 ldisc_send(ssh
->ldisc
, NULL
, 0, 0);/* cause ldisc to notice changes */
3245 ssh
->channels
= newtree234(ssh_channelcmp
);
3249 if (ssh
->pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
3250 ssh
->pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
3251 long len
= GET_32BIT(ssh
->pktin
.body
);
3253 from_backend(ssh
->frontend
,
3254 ssh
->pktin
.type
== SSH1_SMSG_STDERR_DATA
,
3255 (char *)(ssh
->pktin
.body
) + 4, len
);
3256 if (!ssh
->v1_stdout_throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
3257 ssh
->v1_stdout_throttling
= 1;
3258 ssh1_throttle(ssh
, +1);
3260 } else if (ssh
->pktin
.type
== SSH1_MSG_DISCONNECT
) {
3261 ssh
->state
= SSH_STATE_CLOSED
;
3262 logevent("Received disconnect request");
3264 } else if (ssh
->pktin
.type
== SSH1_SMSG_X11_OPEN
) {
3265 /* Remote side is trying to open a channel to talk to our
3266 * X-Server. Give them back a local channel number. */
3267 struct ssh_channel
*c
;
3269 logevent("Received X11 connect request");
3270 /* Refuse if X11 forwarding is disabled. */
3271 if (!ssh
->X11_fwd_enabled
) {
3272 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3273 PKT_INT
, GET_32BIT(ssh
->pktin
.body
), PKT_END
);
3274 logevent("Rejected X11 connect request");
3276 c
= smalloc(sizeof(struct ssh_channel
));
3279 if (x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
,
3280 ssh
->x11auth
) != NULL
) {
3281 logevent("opening X11 forward connection failed");
3283 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3284 PKT_INT
, GET_32BIT(ssh
->pktin
.body
),
3288 ("opening X11 forward connection succeeded");
3289 c
->remoteid
= GET_32BIT(ssh
->pktin
.body
);
3290 c
->localid
= alloc_channel_id(ssh
);
3292 c
->v
.v1
.throttling
= 0;
3293 c
->type
= CHAN_X11
; /* identify channel type */
3294 add234(ssh
->channels
, c
);
3295 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3296 PKT_INT
, c
->remoteid
, PKT_INT
,
3297 c
->localid
, PKT_END
);
3298 logevent("Opened X11 forward channel");
3301 } else if (ssh
->pktin
.type
== SSH1_SMSG_AGENT_OPEN
) {
3302 /* Remote side is trying to open a channel to talk to our
3303 * agent. Give them back a local channel number. */
3304 struct ssh_channel
*c
;
3306 /* Refuse if agent forwarding is disabled. */
3307 if (!ssh
->agentfwd_enabled
) {
3308 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3309 PKT_INT
, GET_32BIT(ssh
->pktin
.body
), PKT_END
);
3311 c
= smalloc(sizeof(struct ssh_channel
));
3313 c
->remoteid
= GET_32BIT(ssh
->pktin
.body
);
3314 c
->localid
= alloc_channel_id(ssh
);
3316 c
->v
.v1
.throttling
= 0;
3317 c
->type
= CHAN_AGENT
; /* identify channel type */
3318 c
->u
.a
.lensofar
= 0;
3319 add234(ssh
->channels
, c
);
3320 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3321 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
3324 } else if (ssh
->pktin
.type
== SSH1_MSG_PORT_OPEN
) {
3325 /* Remote side is trying to open a channel to talk to a
3326 * forwarded port. Give them back a local channel number. */
3327 struct ssh_channel
*c
;
3328 struct ssh_rportfwd pf
;
3330 char host
[256], buf
[1024];
3332 c
= smalloc(sizeof(struct ssh_channel
));
3335 hostsize
= GET_32BIT(ssh
->pktin
.body
+4);
3336 for (h
= host
, p
= (char *)(ssh
->pktin
.body
+8);
3337 hostsize
!= 0; hostsize
--) {
3338 if (h
+1 < host
+sizeof(host
))
3343 port
= GET_32BIT(p
);
3345 strcpy(pf
.dhost
, host
);
3348 if (find234(ssh
->rportfwds
, &pf
, NULL
) == NULL
) {
3349 sprintf(buf
, "Rejected remote port open request for %s:%d",
3352 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3353 PKT_INT
, GET_32BIT(ssh
->pktin
.body
), PKT_END
);
3355 sprintf(buf
, "Received remote port open request for %s:%d",
3358 e
= pfd_newconnect(&c
->u
.pfd
.s
, host
, port
, c
);
3361 sprintf(buf
, "Port open failed: %s", e
);
3364 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3365 PKT_INT
, GET_32BIT(ssh
->pktin
.body
),
3368 c
->remoteid
= GET_32BIT(ssh
->pktin
.body
);
3369 c
->localid
= alloc_channel_id(ssh
);
3371 c
->v
.v1
.throttling
= 0;
3372 c
->type
= CHAN_SOCKDATA
; /* identify channel type */
3373 add234(ssh
->channels
, c
);
3374 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3375 PKT_INT
, c
->remoteid
, PKT_INT
,
3376 c
->localid
, PKT_END
);
3377 logevent("Forwarded port opened successfully");
3381 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
) {
3382 unsigned int remoteid
= GET_32BIT(ssh
->pktin
.body
);
3383 unsigned int localid
= GET_32BIT(ssh
->pktin
.body
+4);
3384 struct ssh_channel
*c
;
3386 c
= find234(ssh
->channels
, &remoteid
, ssh_channelfind
);
3387 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
3388 c
->remoteid
= localid
;
3389 c
->type
= CHAN_SOCKDATA
;
3390 c
->v
.v1
.throttling
= 0;
3391 pfd_confirm(c
->u
.pfd
.s
);
3394 if (c
&& c
->closes
) {
3396 * We have a pending close on this channel,
3397 * which we decided on before the server acked
3398 * the channel open. So now we know the
3399 * remoteid, we can close it again.
3401 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE
,
3402 PKT_INT
, c
->remoteid
, PKT_END
);
3405 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_OPEN_FAILURE
) {
3406 unsigned int remoteid
= GET_32BIT(ssh
->pktin
.body
);
3407 struct ssh_channel
*c
;
3409 c
= find234(ssh
->channels
, &remoteid
, ssh_channelfind
);
3410 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
3411 logevent("Forwarded connection refused by server");
3412 pfd_close(c
->u
.pfd
.s
);
3413 del234(ssh
->channels
, c
);
3417 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE
||
3418 ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
) {
3419 /* Remote side closes a channel. */
3420 unsigned i
= GET_32BIT(ssh
->pktin
.body
);
3421 struct ssh_channel
*c
;
3422 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
3423 if (c
&& ((int)c
->remoteid
) != -1) {
3426 (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
1 : 2);
3428 if ((c
->closes
== 0) && (c
->type
== CHAN_X11
)) {
3429 logevent("Forwarded X11 connection terminated");
3430 assert(c
->u
.x11
.s
!= NULL
);
3431 x11_close(c
->u
.x11
.s
);
3434 if ((c
->closes
== 0) && (c
->type
== CHAN_SOCKDATA
)) {
3435 logevent("Forwarded port closed");
3436 assert(c
->u
.pfd
.s
!= NULL
);
3437 pfd_close(c
->u
.pfd
.s
);
3441 c
->closes
|= (closetype
<< 2); /* seen this message */
3442 if (!(c
->closes
& closetype
)) {
3443 send_packet(ssh
, ssh
->pktin
.type
, PKT_INT
, c
->remoteid
,
3445 c
->closes
|= closetype
; /* sent it too */
3448 if (c
->closes
== 15) {
3449 del234(ssh
->channels
, c
);
3453 bombout((ssh
,"Received CHANNEL_CLOSE%s for %s channel %d\n",
3454 ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
"" :
3455 "_CONFIRMATION", c ?
"half-open" : "nonexistent",
3458 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_DATA
) {
3459 /* Data sent down one of our channels. */
3460 int i
= GET_32BIT(ssh
->pktin
.body
);
3461 int len
= GET_32BIT(ssh
->pktin
.body
+ 4);
3462 unsigned char *p
= ssh
->pktin
.body
+ 8;
3463 struct ssh_channel
*c
;
3464 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
3469 bufsize
= x11_send(c
->u
.x11
.s
, (char *)p
, len
);
3472 bufsize
= pfd_send(c
->u
.pfd
.s
, (char *)p
, len
);
3475 /* Data for an agent message. Buffer it. */
3477 if (c
->u
.a
.lensofar
< 4) {
3478 int l
= min(4 - c
->u
.a
.lensofar
, len
);
3479 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
,
3483 c
->u
.a
.lensofar
+= l
;
3485 if (c
->u
.a
.lensofar
== 4) {
3487 4 + GET_32BIT(c
->u
.a
.msglen
);
3488 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
3489 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
3491 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
3493 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
3495 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
,
3499 c
->u
.a
.lensofar
+= l
;
3501 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
3502 void *reply
, *sentreply
;
3504 agent_query(c
->u
.a
.message
,
3505 c
->u
.a
.totallen
, &reply
,
3510 /* Fake SSH_AGENT_FAILURE. */
3511 sentreply
= "\0\0\0\1\5";
3514 send_packet(ssh
, SSH1_MSG_CHANNEL_DATA
,
3515 PKT_INT
, c
->remoteid
,
3517 PKT_DATA
, sentreply
, replylen
,
3521 sfree(c
->u
.a
.message
);
3522 c
->u
.a
.lensofar
= 0;
3525 bufsize
= 0; /* agent channels never back up */
3528 if (!c
->v
.v1
.throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
3529 c
->v
.v1
.throttling
= 1;
3530 ssh1_throttle(ssh
, +1);
3533 } else if (ssh
->pktin
.type
== SSH1_SMSG_SUCCESS
) {
3534 /* may be from EXEC_SHELL on some servers */
3535 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3536 /* may be from EXEC_SHELL on some servers
3537 * if no pty is available or in other odd cases. Ignore */
3538 } else if (ssh
->pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
3540 ssh
->exitcode
= GET_32BIT(ssh
->pktin
.body
);
3541 sprintf(buf
, "Server sent command exit status %d",
3544 send_packet(ssh
, SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
3546 * In case `helpful' firewalls or proxies tack
3547 * extra human-readable text on the end of the
3548 * session which we might mistake for another
3549 * encrypted packet, we close the session once
3550 * we've sent EXIT_CONFIRMATION.
3552 ssh
->state
= SSH_STATE_CLOSED
;
3555 bombout((ssh
,"Strange packet received: type %d", ssh
->pktin
.type
));
3560 int len
= min(inlen
, 512);
3561 send_packet(ssh
, SSH1_CMSG_STDIN_DATA
,
3562 PKT_INT
, len
, PKT_DATA
, in
, len
, PKT_END
);
3573 * Utility routine for decoding comma-separated strings in KEXINIT.
3575 static int in_commasep_string(char *needle
, char *haystack
, int haylen
)
3578 if (!needle
|| !haystack
) /* protect against null pointers */
3580 needlen
= strlen(needle
);
3583 * Is it at the start of the string?
3585 if (haylen
>= needlen
&& /* haystack is long enough */
3586 !memcmp(needle
, haystack
, needlen
) && /* initial match */
3587 (haylen
== needlen
|| haystack
[needlen
] == ',')
3588 /* either , or EOS follows */
3592 * If not, search for the next comma and resume after that.
3593 * If no comma found, terminate.
3595 while (haylen
> 0 && *haystack
!= ',')
3596 haylen
--, haystack
++;
3599 haylen
--, haystack
++; /* skip over comma itself */
3604 * SSH2 key creation method.
3606 static void ssh2_mkkey(Ssh ssh
, Bignum K
, unsigned char *H
,
3607 unsigned char *sessid
, char chr
,
3608 unsigned char *keyspace
)
3611 /* First 20 bytes. */
3613 if (!(ssh
->remote_bugs
& BUG_SSH2_DERIVEKEY
))
3615 SHA_Bytes(&s
, H
, 20);
3616 SHA_Bytes(&s
, &chr
, 1);
3617 SHA_Bytes(&s
, sessid
, 20);
3618 SHA_Final(&s
, keyspace
);
3619 /* Next 20 bytes. */
3621 if (!(ssh
->remote_bugs
& BUG_SSH2_DERIVEKEY
))
3623 SHA_Bytes(&s
, H
, 20);
3624 SHA_Bytes(&s
, keyspace
, 20);
3625 SHA_Final(&s
, keyspace
+ 20);
3629 * Handle the SSH2 transport layer.
3631 static int do_ssh2_transport(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
3633 struct do_ssh2_transport_state
{
3634 int nbits
, pbits
, warn
;
3635 Bignum p
, g
, e
, f
, K
;
3636 int kex_init_value
, kex_reply_value
;
3637 const struct ssh_mac
**maclist
;
3639 const struct ssh2_cipher
*cscipher_tobe
;
3640 const struct ssh2_cipher
*sccipher_tobe
;
3641 const struct ssh_mac
*csmac_tobe
;
3642 const struct ssh_mac
*scmac_tobe
;
3643 const struct ssh_compress
*cscomp_tobe
;
3644 const struct ssh_compress
*sccomp_tobe
;
3645 char *hostkeydata
, *sigdata
, *keystr
, *fingerprint
;
3646 int hostkeylen
, siglen
;
3647 void *hkey
; /* actual host key */
3648 unsigned char exchange_hash
[20];
3649 int n_preferred_ciphers
;
3650 const struct ssh2_ciphers
*preferred_ciphers
[CIPHER_MAX
];
3651 const struct ssh_compress
*preferred_comp
;
3654 crState(do_ssh2_transport_state
);
3656 crBegin(ssh
->do_ssh2_transport_crstate
);
3658 s
->cscipher_tobe
= s
->sccipher_tobe
= NULL
;
3659 s
->csmac_tobe
= s
->scmac_tobe
= NULL
;
3660 s
->cscomp_tobe
= s
->sccomp_tobe
= NULL
;
3668 * Set up the preferred ciphers. (NULL => warn below here)
3670 s
->n_preferred_ciphers
= 0;
3671 for (i
= 0; i
< CIPHER_MAX
; i
++) {
3672 switch (cfg
.ssh_cipherlist
[i
]) {
3673 case CIPHER_BLOWFISH
:
3674 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_blowfish
;
3677 if (cfg
.ssh2_des_cbc
) {
3678 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_des
;
3682 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_3des
;
3685 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_aes
;
3688 /* Flag for later. Don't bother if it's the last in
3690 if (i
< CIPHER_MAX
- 1) {
3691 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = NULL
;
3699 * Set up preferred compression.
3701 if (cfg
.compression
)
3702 s
->preferred_comp
= &ssh_zlib
;
3704 s
->preferred_comp
= &ssh_comp_none
;
3707 * Be prepared to work around the buggy MAC problem.
3709 if (ssh
->remote_bugs
& BUG_SSH2_HMAC
)
3710 s
->maclist
= buggymacs
, s
->nmacs
= lenof(buggymacs
);
3712 s
->maclist
= macs
, s
->nmacs
= lenof(macs
);
3716 int i
, j
, cipherstr_started
;
3719 * Construct and send our key exchange packet.
3721 ssh2_pkt_init(ssh
, SSH2_MSG_KEXINIT
);
3722 for (i
= 0; i
< 16; i
++)
3723 ssh2_pkt_addbyte(ssh
, (unsigned char) random_byte());
3724 /* List key exchange algorithms. */
3725 ssh2_pkt_addstring_start(ssh
);
3726 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3727 if (kex_algs
[i
] == &ssh_diffiehellman_gex
&&
3728 (ssh
->remote_bugs
& BUG_SSH2_DH_GEX
))
3730 ssh2_pkt_addstring_str(ssh
, kex_algs
[i
]->name
);
3731 if (i
< lenof(kex_algs
) - 1)
3732 ssh2_pkt_addstring_str(ssh
, ",");
3734 /* List server host key algorithms. */
3735 ssh2_pkt_addstring_start(ssh
);
3736 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3737 ssh2_pkt_addstring_str(ssh
, hostkey_algs
[i
]->name
);
3738 if (i
< lenof(hostkey_algs
) - 1)
3739 ssh2_pkt_addstring_str(ssh
, ",");
3741 /* List client->server encryption algorithms. */
3742 ssh2_pkt_addstring_start(ssh
);
3743 cipherstr_started
= 0;
3744 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
3745 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
3746 if (!c
) continue; /* warning flag */
3747 for (j
= 0; j
< c
->nciphers
; j
++) {
3748 if (cipherstr_started
)
3749 ssh2_pkt_addstring_str(ssh
, ",");
3750 ssh2_pkt_addstring_str(ssh
, c
->list
[j
]->name
);
3751 cipherstr_started
= 1;
3754 /* List server->client encryption algorithms. */
3755 ssh2_pkt_addstring_start(ssh
);
3756 cipherstr_started
= 0;
3757 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
3758 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
3759 if (!c
) continue; /* warning flag */
3760 for (j
= 0; j
< c
->nciphers
; j
++) {
3761 if (cipherstr_started
)
3762 ssh2_pkt_addstring_str(ssh
, ",");
3763 ssh2_pkt_addstring_str(ssh
, c
->list
[j
]->name
);
3764 cipherstr_started
= 1;
3767 /* List client->server MAC algorithms. */
3768 ssh2_pkt_addstring_start(ssh
);
3769 for (i
= 0; i
< s
->nmacs
; i
++) {
3770 ssh2_pkt_addstring_str(ssh
, s
->maclist
[i
]->name
);
3771 if (i
< s
->nmacs
- 1)
3772 ssh2_pkt_addstring_str(ssh
, ",");
3774 /* List server->client MAC algorithms. */
3775 ssh2_pkt_addstring_start(ssh
);
3776 for (i
= 0; i
< s
->nmacs
; i
++) {
3777 ssh2_pkt_addstring_str(ssh
, s
->maclist
[i
]->name
);
3778 if (i
< s
->nmacs
- 1)
3779 ssh2_pkt_addstring_str(ssh
, ",");
3781 /* List client->server compression algorithms. */
3782 ssh2_pkt_addstring_start(ssh
);
3783 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3784 const struct ssh_compress
*c
=
3785 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
3786 ssh2_pkt_addstring_str(ssh
, c
->name
);
3787 if (i
< lenof(compressions
))
3788 ssh2_pkt_addstring_str(ssh
, ",");
3790 /* List server->client compression algorithms. */
3791 ssh2_pkt_addstring_start(ssh
);
3792 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3793 const struct ssh_compress
*c
=
3794 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
3795 ssh2_pkt_addstring_str(ssh
, c
->name
);
3796 if (i
< lenof(compressions
))
3797 ssh2_pkt_addstring_str(ssh
, ",");
3799 /* List client->server languages. Empty list. */
3800 ssh2_pkt_addstring_start(ssh
);
3801 /* List server->client languages. Empty list. */
3802 ssh2_pkt_addstring_start(ssh
);
3803 /* First KEX packet does _not_ follow, because we're not that brave. */
3804 ssh2_pkt_addbool(ssh
, FALSE
);
3806 ssh2_pkt_adduint32(ssh
, 0);
3809 ssh
->exhash
= ssh
->exhashbase
;
3810 sha_string(&ssh
->exhash
, ssh
->pktout
.data
+ 5, ssh
->pktout
.length
- 5);
3816 if (ssh
->pktin
.length
> 5)
3817 sha_string(&ssh
->exhash
, ssh
->pktin
.data
+ 5, ssh
->pktin
.length
- 5);
3820 * Now examine the other side's KEXINIT to see what we're up
3827 if (ssh
->pktin
.type
!= SSH2_MSG_KEXINIT
) {
3828 bombout((ssh
,"expected key exchange packet from server"));
3832 ssh
->hostkey
= NULL
;
3833 s
->cscipher_tobe
= NULL
;
3834 s
->sccipher_tobe
= NULL
;
3835 s
->csmac_tobe
= NULL
;
3836 s
->scmac_tobe
= NULL
;
3837 s
->cscomp_tobe
= NULL
;
3838 s
->sccomp_tobe
= NULL
;
3839 ssh
->pktin
.savedpos
+= 16; /* skip garbage cookie */
3840 ssh2_pkt_getstring(ssh
, &str
, &len
); /* key exchange algorithms */
3841 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3842 if (kex_algs
[i
] == &ssh_diffiehellman_gex
&&
3843 (ssh
->remote_bugs
& BUG_SSH2_DH_GEX
))
3845 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
3846 ssh
->kex
= kex_algs
[i
];
3850 ssh2_pkt_getstring(ssh
, &str
, &len
); /* host key algorithms */
3851 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3852 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
3853 ssh
->hostkey
= hostkey_algs
[i
];
3857 ssh2_pkt_getstring(ssh
, &str
, &len
); /* client->server cipher */
3859 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
3860 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
3864 for (j
= 0; j
< c
->nciphers
; j
++) {
3865 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3866 s
->cscipher_tobe
= c
->list
[j
];
3871 if (s
->cscipher_tobe
) {
3873 askcipher(ssh
->frontend
, s
->cscipher_tobe
->name
, 1);
3877 if (!s
->cscipher_tobe
) {
3878 bombout((ssh
,"Couldn't agree a client-to-server cipher (available: %s)",
3879 str ? str
: "(null)"));
3883 ssh2_pkt_getstring(ssh
, &str
, &len
); /* server->client cipher */
3885 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
3886 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
3890 for (j
= 0; j
< c
->nciphers
; j
++) {
3891 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3892 s
->sccipher_tobe
= c
->list
[j
];
3897 if (s
->sccipher_tobe
) {
3899 askcipher(ssh
->frontend
, s
->sccipher_tobe
->name
, 2);
3903 if (!s
->sccipher_tobe
) {
3904 bombout((ssh
,"Couldn't agree a server-to-client cipher (available: %s)",
3905 str ? str
: "(null)"));
3909 ssh2_pkt_getstring(ssh
, &str
, &len
); /* client->server mac */
3910 for (i
= 0; i
< s
->nmacs
; i
++) {
3911 if (in_commasep_string(s
->maclist
[i
]->name
, str
, len
)) {
3912 s
->csmac_tobe
= s
->maclist
[i
];
3916 ssh2_pkt_getstring(ssh
, &str
, &len
); /* server->client mac */
3917 for (i
= 0; i
< s
->nmacs
; i
++) {
3918 if (in_commasep_string(s
->maclist
[i
]->name
, str
, len
)) {
3919 s
->scmac_tobe
= s
->maclist
[i
];
3923 ssh2_pkt_getstring(ssh
, &str
, &len
); /* client->server compression */
3924 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3925 const struct ssh_compress
*c
=
3926 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
3927 if (in_commasep_string(c
->name
, str
, len
)) {
3932 ssh2_pkt_getstring(ssh
, &str
, &len
); /* server->client compression */
3933 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3934 const struct ssh_compress
*c
=
3935 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
3936 if (in_commasep_string(c
->name
, str
, len
)) {
3944 * Work out the number of bits of key we will need from the key
3945 * exchange. We start with the maximum key length of either
3951 csbits
= s
->cscipher_tobe
->keylen
;
3952 scbits
= s
->sccipher_tobe
->keylen
;
3953 s
->nbits
= (csbits
> scbits ? csbits
: scbits
);
3955 /* The keys only have 160-bit entropy, since they're based on
3956 * a SHA-1 hash. So cap the key size at 160 bits. */
3961 * If we're doing Diffie-Hellman group exchange, start by
3962 * requesting a group.
3964 if (ssh
->kex
== &ssh_diffiehellman_gex
) {
3965 logevent("Doing Diffie-Hellman group exchange");
3966 ssh
->pkt_ctx
|= SSH2_PKTCTX_DHGEX
;
3968 * Work out how big a DH group we will need to allow that
3971 s
->pbits
= 512 << ((s
->nbits
- 1) / 64);
3972 ssh2_pkt_init(ssh
, SSH2_MSG_KEX_DH_GEX_REQUEST
);
3973 ssh2_pkt_adduint32(ssh
, s
->pbits
);
3977 if (ssh
->pktin
.type
!= SSH2_MSG_KEX_DH_GEX_GROUP
) {
3978 bombout((ssh
,"expected key exchange group packet from server"));
3981 s
->p
= ssh2_pkt_getmp(ssh
);
3982 s
->g
= ssh2_pkt_getmp(ssh
);
3983 ssh
->kex_ctx
= dh_setup_group(s
->p
, s
->g
);
3984 s
->kex_init_value
= SSH2_MSG_KEX_DH_GEX_INIT
;
3985 s
->kex_reply_value
= SSH2_MSG_KEX_DH_GEX_REPLY
;
3987 ssh
->pkt_ctx
|= SSH2_PKTCTX_DHGROUP1
;
3988 ssh
->kex_ctx
= dh_setup_group1();
3989 s
->kex_init_value
= SSH2_MSG_KEXDH_INIT
;
3990 s
->kex_reply_value
= SSH2_MSG_KEXDH_REPLY
;
3993 logevent("Doing Diffie-Hellman key exchange");
3995 * Now generate and send e for Diffie-Hellman.
3997 s
->e
= dh_create_e(ssh
->kex_ctx
, s
->nbits
* 2);
3998 ssh2_pkt_init(ssh
, s
->kex_init_value
);
3999 ssh2_pkt_addmp(ssh
, s
->e
);
4003 if (ssh
->pktin
.type
!= s
->kex_reply_value
) {
4004 bombout((ssh
,"expected key exchange reply packet from server"));
4007 ssh2_pkt_getstring(ssh
, &s
->hostkeydata
, &s
->hostkeylen
);
4008 s
->f
= ssh2_pkt_getmp(ssh
);
4009 ssh2_pkt_getstring(ssh
, &s
->sigdata
, &s
->siglen
);
4011 s
->K
= dh_find_K(ssh
->kex_ctx
, s
->f
);
4013 sha_string(&ssh
->exhash
, s
->hostkeydata
, s
->hostkeylen
);
4014 if (ssh
->kex
== &ssh_diffiehellman_gex
) {
4015 sha_uint32(&ssh
->exhash
, s
->pbits
);
4016 sha_mpint(&ssh
->exhash
, s
->p
);
4017 sha_mpint(&ssh
->exhash
, s
->g
);
4019 sha_mpint(&ssh
->exhash
, s
->e
);
4020 sha_mpint(&ssh
->exhash
, s
->f
);
4021 sha_mpint(&ssh
->exhash
, s
->K
);
4022 SHA_Final(&ssh
->exhash
, s
->exchange_hash
);
4024 dh_cleanup(ssh
->kex_ctx
);
4027 debug(("Exchange hash is:\n"));
4028 dmemdump(s
->exchange_hash
, 20);
4031 s
->hkey
= ssh
->hostkey
->newkey(s
->hostkeydata
, s
->hostkeylen
);
4033 !ssh
->hostkey
->verifysig(s
->hkey
, s
->sigdata
, s
->siglen
,
4034 (char *)s
->exchange_hash
, 20)) {
4035 bombout((ssh
,"Server's host key did not match the signature supplied"));
4040 * Authenticate remote host: verify host key. (We've already
4041 * checked the signature of the exchange hash.)
4043 s
->keystr
= ssh
->hostkey
->fmtkey(s
->hkey
);
4044 s
->fingerprint
= ssh
->hostkey
->fingerprint(s
->hkey
);
4045 verify_ssh_host_key(ssh
->frontend
,
4046 ssh
->savedhost
, ssh
->savedport
, ssh
->hostkey
->keytype
,
4047 s
->keystr
, s
->fingerprint
);
4048 if (s
->first_kex
) { /* don't bother logging this in rekeys */
4049 logevent("Host key fingerprint is:");
4050 logevent(s
->fingerprint
);
4052 sfree(s
->fingerprint
);
4054 ssh
->hostkey
->freekey(s
->hkey
);
4057 * Send SSH2_MSG_NEWKEYS.
4059 ssh2_pkt_init(ssh
, SSH2_MSG_NEWKEYS
);
4063 * Expect SSH2_MSG_NEWKEYS from server.
4066 if (ssh
->pktin
.type
!= SSH2_MSG_NEWKEYS
) {
4067 bombout((ssh
,"expected new-keys packet from server"));
4072 * Create and initialise session keys.
4074 if (ssh
->cs_cipher_ctx
)
4075 ssh
->cscipher
->free_context(ssh
->cs_cipher_ctx
);
4076 ssh
->cscipher
= s
->cscipher_tobe
;
4077 ssh
->cs_cipher_ctx
= ssh
->cscipher
->make_context();
4079 if (ssh
->sc_cipher_ctx
)
4080 ssh
->sccipher
->free_context(ssh
->sc_cipher_ctx
);
4081 ssh
->sccipher
= s
->sccipher_tobe
;
4082 ssh
->sc_cipher_ctx
= ssh
->sccipher
->make_context();
4084 if (ssh
->cs_mac_ctx
)
4085 ssh
->csmac
->free_context(ssh
->cs_mac_ctx
);
4086 ssh
->csmac
= s
->csmac_tobe
;
4087 ssh
->cs_mac_ctx
= ssh
->csmac
->make_context();
4089 if (ssh
->sc_mac_ctx
)
4090 ssh
->scmac
->free_context(ssh
->sc_mac_ctx
);
4091 ssh
->scmac
= s
->scmac_tobe
;
4092 ssh
->sc_mac_ctx
= ssh
->scmac
->make_context();
4094 if (ssh
->cs_comp_ctx
)
4095 ssh
->cscomp
->compress_cleanup(ssh
->cs_comp_ctx
);
4096 ssh
->cscomp
= s
->cscomp_tobe
;
4097 ssh
->cs_comp_ctx
= ssh
->cscomp
->compress_init();
4099 if (ssh
->sc_comp_ctx
)
4100 ssh
->sccomp
->decompress_cleanup(ssh
->sc_comp_ctx
);
4101 ssh
->sccomp
= s
->sccomp_tobe
;
4102 ssh
->sc_comp_ctx
= ssh
->sccomp
->decompress_init();
4105 * Set IVs after keys. Here we use the exchange hash from the
4106 * _first_ key exchange.
4109 unsigned char keyspace
[40];
4111 memcpy(ssh
->v2_session_id
, s
->exchange_hash
,
4112 sizeof(s
->exchange_hash
));
4113 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'C',keyspace
);
4114 ssh
->cscipher
->setkey(ssh
->cs_cipher_ctx
, keyspace
);
4115 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'D',keyspace
);
4116 ssh
->sccipher
->setkey(ssh
->sc_cipher_ctx
, keyspace
);
4117 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'A',keyspace
);
4118 ssh
->cscipher
->setiv(ssh
->cs_cipher_ctx
, keyspace
);
4119 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'B',keyspace
);
4120 ssh
->sccipher
->setiv(ssh
->sc_cipher_ctx
, keyspace
);
4121 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'E',keyspace
);
4122 ssh
->csmac
->setkey(ssh
->cs_mac_ctx
, keyspace
);
4123 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'F',keyspace
);
4124 ssh
->scmac
->setkey(ssh
->sc_mac_ctx
, keyspace
);
4126 logeventf(ssh
, "Initialised %.200s client->server encryption",
4127 ssh
->cscipher
->text_name
);
4128 logeventf(ssh
, "Initialised %.200s server->client encryption",
4129 ssh
->sccipher
->text_name
);
4130 if (ssh
->cscomp
->text_name
)
4131 logeventf(ssh
, "Initialised %s compression",
4132 ssh
->cscomp
->text_name
);
4133 if (ssh
->sccomp
->text_name
)
4134 logeventf(ssh
, "Initialised %s decompression",
4135 ssh
->sccomp
->text_name
);
4138 * If this is the first key exchange phase, we must pass the
4139 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4140 * wants to see it but because it will need time to initialise
4141 * itself before it sees an actual packet. In subsequent key
4142 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4143 * it would only confuse the layer above.
4145 if (!s
->first_kex
) {
4151 * Now we're encrypting. Begin returning 1 to the protocol main
4152 * function so that other things can run on top of the
4153 * transport. If we ever see a KEXINIT, we must go back to the
4156 while (!(ispkt
&& ssh
->pktin
.type
== SSH2_MSG_KEXINIT
)) {
4159 logevent("Server initiated key re-exchange");
4160 goto begin_key_exchange
;
4166 * Add data to an SSH2 channel output buffer.
4168 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
4171 bufchain_add(&c
->v
.v2
.outbuffer
, buf
, len
);
4175 * Attempt to send data on an SSH2 channel.
4177 static int ssh2_try_send(struct ssh_channel
*c
)
4181 while (c
->v
.v2
.remwindow
> 0 && bufchain_size(&c
->v
.v2
.outbuffer
) > 0) {
4184 bufchain_prefix(&c
->v
.v2
.outbuffer
, &data
, &len
);
4185 if ((unsigned)len
> c
->v
.v2
.remwindow
)
4186 len
= c
->v
.v2
.remwindow
;
4187 if ((unsigned)len
> c
->v
.v2
.remmaxpkt
)
4188 len
= c
->v
.v2
.remmaxpkt
;
4189 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_DATA
);
4190 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
4191 ssh2_pkt_addstring_start(ssh
);
4192 ssh2_pkt_addstring_data(ssh
, data
, len
);
4194 bufchain_consume(&c
->v
.v2
.outbuffer
, len
);
4195 c
->v
.v2
.remwindow
-= len
;
4199 * After having sent as much data as we can, return the amount
4202 return bufchain_size(&c
->v
.v2
.outbuffer
);
4206 * Potentially enlarge the window on an SSH2 channel.
4208 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
)
4213 * Never send WINDOW_ADJUST for a channel that the remote side
4214 * already thinks it's closed; there's no point, since it won't
4215 * be sending any more data anyway.
4220 if (newwin
> c
->v
.v2
.locwindow
) {
4221 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4222 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
4223 ssh2_pkt_adduint32(ssh
, newwin
- c
->v
.v2
.locwindow
);
4225 c
->v
.v2
.locwindow
= newwin
;
4230 * Handle the SSH2 userauth and connection layers.
4232 static void do_ssh2_authconn(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
4234 struct do_ssh2_authconn_state
{
4236 AUTH_INVALID
, AUTH_PUBLICKEY_AGENT
, AUTH_PUBLICKEY_FILE
,
4238 AUTH_KEYBOARD_INTERACTIVE
4242 AUTH_TYPE_PUBLICKEY
,
4243 AUTH_TYPE_PUBLICKEY_OFFER_LOUD
,
4244 AUTH_TYPE_PUBLICKEY_OFFER_QUIET
,
4246 AUTH_TYPE_KEYBOARD_INTERACTIVE
,
4247 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4249 int gotit
, need_pw
, can_pubkey
, can_passwd
, can_keyb_inter
;
4250 int tried_pubkey_config
, tried_agent
, tried_keyb_inter
;
4251 int kbd_inter_running
;
4253 int num_prompts
, curr_prompt
, echo
;
4258 void *publickey_blob
;
4259 int publickey_bloblen
;
4260 unsigned char request
[5], *response
, *p
;
4264 char *pkblob
, *alg
, *commentp
;
4265 int pklen
, alglen
, commentlen
;
4266 int siglen
, retlen
, len
;
4267 char *q
, *agentreq
, *ret
;
4270 crState(do_ssh2_authconn_state
);
4272 crBegin(ssh
->do_ssh2_authconn_crstate
);
4275 * Request userauth protocol, and await a response to it.
4277 ssh2_pkt_init(ssh
, SSH2_MSG_SERVICE_REQUEST
);
4278 ssh2_pkt_addstring(ssh
, "ssh-userauth");
4280 crWaitUntilV(ispkt
);
4281 if (ssh
->pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
) {
4282 bombout((ssh
,"Server refused user authentication protocol"));
4287 * We repeat this whole loop, including the username prompt,
4288 * until we manage a successful authentication. If the user
4289 * types the wrong _password_, they can be sent back to the
4290 * beginning to try another username, if this is configured on.
4291 * (If they specify a username in the config, they are never
4292 * asked, even if they do give a wrong password.)
4294 * I think this best serves the needs of
4296 * - the people who have no configuration, no keys, and just
4297 * want to try repeated (username,password) pairs until they
4298 * type both correctly
4300 * - people who have keys and configuration but occasionally
4301 * need to fall back to passwords
4303 * - people with a key held in Pageant, who might not have
4304 * logged in to a particular machine before; so they want to
4305 * type a username, and then _either_ their key will be
4306 * accepted, _or_ they will type a password. If they mistype
4307 * the username they will want to be able to get back and
4310 s
->username
[0] = '\0';
4311 s
->got_username
= FALSE
;
4316 if (s
->got_username
&& !cfg
.change_username
) {
4318 * We got a username last time round this loop, and
4319 * with change_username turned off we don't try to get
4322 } else if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
4323 if (ssh_get_line
&& !ssh_getline_pw_only
) {
4324 if (!ssh_get_line("login as: ",
4325 s
->username
, sizeof(s
->username
), FALSE
)) {
4327 * get_line failed to get a username.
4330 logevent("No username provided. Abandoning session.");
4331 ssh
->state
= SSH_STATE_CLOSED
;
4335 int ret
; /* need not be saved across crReturn */
4336 c_write_str(ssh
, "login as: ");
4338 setup_userpass_input(ssh
, s
->username
, sizeof(s
->username
), 1);
4340 crWaitUntilV(!ispkt
);
4341 ret
= process_userpass_input(ssh
, in
, inlen
);
4345 c_write_str(ssh
, "\r\n");
4347 s
->username
[strcspn(s
->username
, "\n\r")] = '\0';
4350 strncpy(s
->username
, cfg
.username
, sizeof(s
->username
));
4351 s
->username
[sizeof(s
->username
)-1] = '\0';
4352 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
4353 stuff
= dupprintf("Using username \"%s\".\r\n", s
->username
);
4354 c_write_str(ssh
, stuff
);
4358 s
->got_username
= TRUE
;
4361 * Send an authentication request using method "none": (a)
4362 * just in case it succeeds, and (b) so that we know what
4363 * authentication methods we can usefully try next.
4365 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4367 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4368 ssh2_pkt_addstring(ssh
, s
->username
);
4369 ssh2_pkt_addstring(ssh
, "ssh-connection");/* service requested */
4370 ssh2_pkt_addstring(ssh
, "none"); /* method */
4372 s
->type
= AUTH_TYPE_NONE
;
4374 s
->we_are_in
= FALSE
;
4376 s
->tried_pubkey_config
= FALSE
;
4377 s
->tried_agent
= FALSE
;
4378 s
->tried_keyb_inter
= FALSE
;
4379 s
->kbd_inter_running
= FALSE
;
4380 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
4383 logeventf(ssh
, "Reading private key file \"%.150s\"", cfg
.keyfile
);
4384 keytype
= key_type(cfg
.keyfile
);
4385 if (keytype
== SSH_KEYTYPE_SSH2
) {
4387 ssh2_userkey_loadpub(cfg
.keyfile
, NULL
,
4388 &s
->publickey_bloblen
);
4391 logeventf(ssh
, "Unable to use this key file (%s)",
4392 key_type_to_str(keytype
));
4393 msgbuf
= dupprintf("Unable to use key file \"%.150s\""
4394 " (%s)\r\n", cfg
.keyfile
,
4395 key_type_to_str(keytype
));
4396 c_write_str(ssh
, msgbuf
);
4398 s
->publickey_blob
= NULL
;
4401 s
->publickey_blob
= NULL
;
4405 * Wait for the result of the last authentication request.
4408 crWaitUntilV(ispkt
);
4409 while (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_BANNER
) {
4413 * Don't show the banner if we're operating in
4414 * non-verbose non-interactive mode. (It's probably
4415 * a script, which means nobody will read the
4416 * banner _anyway_, and moreover the printing of
4417 * the banner will screw up processing on the
4418 * output of (say) plink.)
4420 if (flags
& (FLAG_VERBOSE
| FLAG_INTERACTIVE
)) {
4421 ssh2_pkt_getstring(ssh
, &banner
, &size
);
4423 c_write_untrusted(ssh
, banner
, size
);
4425 crWaitUntilV(ispkt
);
4427 if (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_SUCCESS
) {
4428 logevent("Access granted");
4429 s
->we_are_in
= TRUE
;
4433 if (s
->kbd_inter_running
&&
4434 ssh
->pktin
.type
== SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4436 * This is either a further set-of-prompts packet
4437 * in keyboard-interactive authentication, or it's
4438 * the same one and we came back here with `gotit'
4439 * set. In the former case, we must reset the
4440 * curr_prompt variable.
4444 } else if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_FAILURE
) {
4445 bombout((ssh
,"Strange packet received during authentication: type %d",
4453 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4454 * we can look at the string in it and know what we can
4455 * helpfully try next.
4457 if (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
) {
4460 ssh2_pkt_getstring(ssh
, &methods
, &methlen
);
4461 s
->kbd_inter_running
= FALSE
;
4462 if (!ssh2_pkt_getbool(ssh
)) {
4464 * We have received an unequivocal Access
4465 * Denied. This can translate to a variety of
4468 * - if we'd just tried "none" authentication,
4469 * it's not worth printing anything at all
4471 * - if we'd just tried a public key _offer_,
4472 * the message should be "Server refused our
4473 * key" (or no message at all if the key
4474 * came from Pageant)
4476 * - if we'd just tried anything else, the
4477 * message really should be "Access denied".
4479 * Additionally, if we'd just tried password
4480 * authentication, we should break out of this
4481 * whole loop so as to go back to the username
4484 if (s
->type
== AUTH_TYPE_NONE
) {
4486 } else if (s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
||
4487 s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_QUIET
) {
4488 if (s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
)
4489 c_write_str(ssh
, "Server refused our key\r\n");
4490 logevent("Server refused public key");
4491 } else if (s
->type
==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
) {
4492 /* server declined keyboard-interactive; ignore */
4494 c_write_str(ssh
, "Access denied\r\n");
4495 logevent("Access denied");
4496 if (s
->type
== AUTH_TYPE_PASSWORD
) {
4497 s
->we_are_in
= FALSE
;
4502 c_write_str(ssh
, "Further authentication required\r\n");
4503 logevent("Further authentication required");
4507 in_commasep_string("publickey", methods
, methlen
);
4509 in_commasep_string("password", methods
, methlen
);
4510 s
->can_keyb_inter
= cfg
.try_ki_auth
&&
4511 in_commasep_string("keyboard-interactive", methods
, methlen
);
4515 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4518 * Most password/passphrase prompts will be
4519 * non-echoing, so we set this to 0 by default.
4520 * Exception is that some keyboard-interactive prompts
4521 * can be echoing, in which case we'll set this to 1.
4525 if (!s
->method
&& s
->can_pubkey
&&
4526 agent_exists() && !s
->tried_agent
) {
4528 * Attempt public-key authentication using Pageant.
4533 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4534 ssh
->pkt_ctx
|= SSH2_PKTCTX_PUBLICKEY
;
4536 s
->tried_agent
= TRUE
;
4538 logevent("Pageant is running. Requesting keys.");
4540 /* Request the keys held by the agent. */
4541 PUT_32BIT(s
->request
, 1);
4542 s
->request
[4] = SSH2_AGENTC_REQUEST_IDENTITIES
;
4543 agent_query(s
->request
, 5, &r
, &s
->responselen
);
4544 s
->response
= (unsigned char *) r
;
4545 if (s
->response
&& s
->responselen
>= 5 &&
4546 s
->response
[4] == SSH2_AGENT_IDENTITIES_ANSWER
) {
4547 s
->p
= s
->response
+ 5;
4548 s
->nkeys
= GET_32BIT(s
->p
);
4552 sprintf(buf
, "Pageant has %d SSH2 keys", s
->nkeys
);
4555 for (s
->keyi
= 0; s
->keyi
< s
->nkeys
; s
->keyi
++) {
4560 sprintf(buf
, "Trying Pageant key #%d", s
->keyi
);
4563 s
->pklen
= GET_32BIT(s
->p
);
4565 if (s
->publickey_blob
&&
4566 s
->pklen
== s
->publickey_bloblen
&&
4567 !memcmp(s
->p
, s
->publickey_blob
,
4568 s
->publickey_bloblen
)) {
4569 logevent("This key matches configured key file");
4570 s
->tried_pubkey_config
= 1;
4572 s
->pkblob
= (char *)s
->p
;
4574 s
->alglen
= GET_32BIT(s
->pkblob
);
4575 s
->alg
= s
->pkblob
+ 4;
4576 s
->commentlen
= GET_32BIT(s
->p
);
4578 s
->commentp
= (char *)s
->p
;
4579 s
->p
+= s
->commentlen
;
4580 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4581 ssh2_pkt_addstring(ssh
, s
->username
);
4582 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4583 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4584 ssh2_pkt_addbool(ssh
, FALSE
); /* no signature included */
4585 ssh2_pkt_addstring_start(ssh
);
4586 ssh2_pkt_addstring_data(ssh
, s
->alg
, s
->alglen
);
4587 ssh2_pkt_addstring_start(ssh
);
4588 ssh2_pkt_addstring_data(ssh
, s
->pkblob
, s
->pklen
);
4591 crWaitUntilV(ispkt
);
4592 if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4593 logevent("Key refused");
4597 if (flags
& FLAG_VERBOSE
) {
4598 c_write_str(ssh
, "Authenticating with "
4600 c_write(ssh
, s
->commentp
, s
->commentlen
);
4601 c_write_str(ssh
, "\" from agent\r\n");
4605 * Server is willing to accept the key.
4606 * Construct a SIGN_REQUEST.
4608 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4609 ssh2_pkt_addstring(ssh
, s
->username
);
4610 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4611 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4612 ssh2_pkt_addbool(ssh
, TRUE
);
4613 ssh2_pkt_addstring_start(ssh
);
4614 ssh2_pkt_addstring_data(ssh
, s
->alg
, s
->alglen
);
4615 ssh2_pkt_addstring_start(ssh
);
4616 ssh2_pkt_addstring_data(ssh
, s
->pkblob
, s
->pklen
);
4618 s
->siglen
= ssh
->pktout
.length
- 5 + 4 + 20;
4619 s
->len
= 1; /* message type */
4620 s
->len
+= 4 + s
->pklen
; /* key blob */
4621 s
->len
+= 4 + s
->siglen
; /* data to sign */
4622 s
->len
+= 4; /* flags */
4623 s
->agentreq
= smalloc(4 + s
->len
);
4624 PUT_32BIT(s
->agentreq
, s
->len
);
4625 s
->q
= s
->agentreq
+ 4;
4626 *s
->q
++ = SSH2_AGENTC_SIGN_REQUEST
;
4627 PUT_32BIT(s
->q
, s
->pklen
);
4629 memcpy(s
->q
, s
->pkblob
, s
->pklen
);
4631 PUT_32BIT(s
->q
, s
->siglen
);
4633 /* Now the data to be signed... */
4634 PUT_32BIT(s
->q
, 20);
4636 memcpy(s
->q
, ssh
->v2_session_id
, 20);
4638 memcpy(s
->q
, ssh
->pktout
.data
+ 5,
4639 ssh
->pktout
.length
- 5);
4640 s
->q
+= ssh
->pktout
.length
- 5;
4641 /* And finally the (zero) flags word. */
4643 agent_query(s
->agentreq
, s
->len
+ 4, &vret
, &s
->retlen
);
4647 if (s
->ret
[4] == SSH2_AGENT_SIGN_RESPONSE
) {
4648 logevent("Sending Pageant's response");
4649 ssh2_add_sigblob(ssh
, s
->pkblob
, s
->pklen
,
4651 GET_32BIT(s
->ret
+ 5));
4657 ("Pageant failed to answer challenge");
4667 if (!s
->method
&& s
->can_pubkey
&& s
->publickey_blob
4668 && !s
->tried_pubkey_config
) {
4669 unsigned char *pub_blob
;
4670 char *algorithm
, *comment
;
4673 s
->tried_pubkey_config
= TRUE
;
4675 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4676 ssh
->pkt_ctx
|= SSH2_PKTCTX_PUBLICKEY
;
4679 * Try the public key supplied in the configuration.
4681 * First, offer the public blob to see if the server is
4682 * willing to accept it.
4685 (unsigned char *)ssh2_userkey_loadpub(cfg
.keyfile
,
4689 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4690 ssh2_pkt_addstring(ssh
, s
->username
);
4691 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4692 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4693 ssh2_pkt_addbool(ssh
, FALSE
); /* no signature included */
4694 ssh2_pkt_addstring(ssh
, algorithm
);
4695 ssh2_pkt_addstring_start(ssh
);
4696 ssh2_pkt_addstring_data(ssh
, (char *)pub_blob
,
4699 logevent("Offered public key"); /* FIXME */
4701 crWaitUntilV(ispkt
);
4702 if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4704 s
->type
= AUTH_TYPE_PUBLICKEY_OFFER_LOUD
;
4705 continue; /* key refused; give up on it */
4708 logevent("Offer of public key accepted");
4710 * Actually attempt a serious authentication using
4713 if (ssh2_userkey_encrypted(cfg
.keyfile
, &comment
)) {
4714 sprintf(s
->pwprompt
,
4715 "Passphrase for key \"%.100s\": ",
4721 c_write_str(ssh
, "Authenticating with public key \"");
4722 c_write_str(ssh
, comment
);
4723 c_write_str(ssh
, "\"\r\n");
4724 s
->method
= AUTH_PUBLICKEY_FILE
;
4728 if (!s
->method
&& s
->can_keyb_inter
&& !s
->tried_keyb_inter
) {
4729 s
->method
= AUTH_KEYBOARD_INTERACTIVE
;
4730 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4731 s
->tried_keyb_inter
= TRUE
;
4733 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4734 ssh
->pkt_ctx
|= SSH2_PKTCTX_KBDINTER
;
4736 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4737 ssh2_pkt_addstring(ssh
, s
->username
);
4738 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4739 ssh2_pkt_addstring(ssh
, "keyboard-interactive"); /* method */
4740 ssh2_pkt_addstring(ssh
, ""); /* lang */
4741 ssh2_pkt_addstring(ssh
, "");
4744 crWaitUntilV(ispkt
);
4745 if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4746 if (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
)
4748 logevent("Keyboard-interactive authentication refused");
4749 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
;
4753 s
->kbd_inter_running
= TRUE
;
4757 if (s
->kbd_inter_running
) {
4758 s
->method
= AUTH_KEYBOARD_INTERACTIVE
;
4759 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4760 s
->tried_keyb_inter
= TRUE
;
4762 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4763 ssh
->pkt_ctx
|= SSH2_PKTCTX_KBDINTER
;
4765 if (s
->curr_prompt
== 0) {
4767 * We've got a fresh USERAUTH_INFO_REQUEST.
4768 * Display header data, and start going through
4771 char *name
, *inst
, *lang
;
4772 int name_len
, inst_len
, lang_len
;
4774 ssh2_pkt_getstring(ssh
, &name
, &name_len
);
4775 ssh2_pkt_getstring(ssh
, &inst
, &inst_len
);
4776 ssh2_pkt_getstring(ssh
, &lang
, &lang_len
);
4778 c_write_untrusted(ssh
, name
, name_len
);
4779 c_write_str(ssh
, "\r\n");
4782 c_write_untrusted(ssh
, inst
, inst_len
);
4783 c_write_str(ssh
, "\r\n");
4785 s
->num_prompts
= ssh2_pkt_getuint32(ssh
);
4789 * If there are prompts remaining in the packet,
4790 * display one and get a response.
4792 if (s
->curr_prompt
< s
->num_prompts
) {
4796 ssh2_pkt_getstring(ssh
, &prompt
, &prompt_len
);
4797 if (prompt_len
> 0) {
4798 strncpy(s
->pwprompt
, prompt
, sizeof(s
->pwprompt
));
4799 s
->pwprompt
[prompt_len
< sizeof(s
->pwprompt
) ?
4800 prompt_len
: sizeof(s
->pwprompt
)-1] = '\0';
4803 "<server failed to send prompt>: ");
4805 s
->echo
= ssh2_pkt_getbool(ssh
);
4811 if (!s
->method
&& s
->can_passwd
) {
4812 s
->method
= AUTH_PASSWORD
;
4813 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4814 ssh
->pkt_ctx
|= SSH2_PKTCTX_PASSWORD
;
4815 sprintf(s
->pwprompt
, "%.90s@%.90s's password: ", s
->username
,
4822 if (!ssh_get_line(s
->pwprompt
, s
->password
,
4823 sizeof(s
->password
), TRUE
)) {
4825 * get_line failed to get a password (for
4826 * example because one was supplied on the
4827 * command line which has already failed to
4830 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
4831 ssh2_pkt_adduint32(ssh
,SSH2_DISCONNECT_BY_APPLICATION
);
4832 ssh2_pkt_addstring(ssh
, "No more passwords available"
4834 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
4836 logevent("Unable to authenticate");
4837 connection_fatal(ssh
->frontend
,
4838 "Unable to authenticate");
4839 ssh
->state
= SSH_STATE_CLOSED
;
4843 int ret
; /* need not be saved across crReturn */
4844 c_write_untrusted(ssh
, s
->pwprompt
, strlen(s
->pwprompt
));
4847 setup_userpass_input(ssh
, s
->password
,
4848 sizeof(s
->password
), s
->echo
);
4850 crWaitUntilV(!ispkt
);
4851 ret
= process_userpass_input(ssh
, in
, inlen
);
4855 c_write_str(ssh
, "\r\n");
4859 if (s
->method
== AUTH_PUBLICKEY_FILE
) {
4861 * We have our passphrase. Now try the actual authentication.
4863 struct ssh2_userkey
*key
;
4865 key
= ssh2_load_userkey(cfg
.keyfile
, s
->password
);
4866 if (key
== SSH2_WRONG_PASSPHRASE
|| key
== NULL
) {
4867 if (key
== SSH2_WRONG_PASSPHRASE
) {
4868 c_write_str(ssh
, "Wrong passphrase\r\n");
4869 s
->tried_pubkey_config
= FALSE
;
4871 c_write_str(ssh
, "Unable to load private key\r\n");
4872 s
->tried_pubkey_config
= TRUE
;
4874 /* Send a spurious AUTH_NONE to return to the top. */
4875 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4876 ssh2_pkt_addstring(ssh
, s
->username
);
4877 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4878 ssh2_pkt_addstring(ssh
, "none"); /* method */
4880 s
->type
= AUTH_TYPE_NONE
;
4882 unsigned char *pkblob
, *sigblob
, *sigdata
;
4883 int pkblob_len
, sigblob_len
, sigdata_len
;
4886 * We have loaded the private key and the server
4887 * has announced that it's willing to accept it.
4888 * Hallelujah. Generate a signature and send it.
4890 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4891 ssh2_pkt_addstring(ssh
, s
->username
);
4892 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4893 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4894 ssh2_pkt_addbool(ssh
, TRUE
);
4895 ssh2_pkt_addstring(ssh
, key
->alg
->name
);
4896 pkblob
= key
->alg
->public_blob(key
->data
, &pkblob_len
);
4897 ssh2_pkt_addstring_start(ssh
);
4898 ssh2_pkt_addstring_data(ssh
, (char *)pkblob
, pkblob_len
);
4901 * The data to be signed is:
4905 * followed by everything so far placed in the
4908 sigdata_len
= ssh
->pktout
.length
- 5 + 4 + 20;
4909 sigdata
= smalloc(sigdata_len
);
4910 PUT_32BIT(sigdata
, 20);
4911 memcpy(sigdata
+ 4, ssh
->v2_session_id
, 20);
4912 memcpy(sigdata
+ 24, ssh
->pktout
.data
+ 5,
4913 ssh
->pktout
.length
- 5);
4914 sigblob
= key
->alg
->sign(key
->data
, (char *)sigdata
,
4915 sigdata_len
, &sigblob_len
);
4916 ssh2_add_sigblob(ssh
, pkblob
, pkblob_len
,
4917 sigblob
, sigblob_len
);
4923 s
->type
= AUTH_TYPE_PUBLICKEY
;
4925 } else if (s
->method
== AUTH_PASSWORD
) {
4927 * We send the password packet lumped tightly together with
4928 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4929 * string long enough to make the total length of the two
4930 * packets constant. This should ensure that a passive
4931 * listener doing traffic analyis can't work out the length
4934 * For this to work, we need an assumption about the
4935 * maximum length of the password packet. I think 256 is
4936 * pretty conservative. Anyone using a password longer than
4937 * that probably doesn't have much to worry about from
4938 * people who find out how long their password is!
4940 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4941 ssh2_pkt_addstring(ssh
, s
->username
);
4942 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4943 ssh2_pkt_addstring(ssh
, "password");
4944 ssh2_pkt_addbool(ssh
, FALSE
);
4945 ssh2_pkt_addstring(ssh
, s
->password
);
4946 memset(s
->password
, 0, sizeof(s
->password
));
4947 ssh2_pkt_defer(ssh
);
4949 * We'll include a string that's an exact multiple of the
4950 * cipher block size. If the cipher is NULL for some
4951 * reason, we don't do this trick at all because we gain
4954 if (ssh
->cscipher
) {
4957 stringlen
= (256 - ssh
->deferred_len
);
4958 stringlen
+= ssh
->cscipher
->blksize
- 1;
4959 stringlen
-= (stringlen
% ssh
->cscipher
->blksize
);
4962 * Temporarily disable actual compression,
4963 * so we can guarantee to get this string
4964 * exactly the length we want it. The
4965 * compression-disabling routine should
4966 * return an integer indicating how many
4967 * bytes we should adjust our string length
4971 ssh
->cscomp
->disable_compression(ssh
->cs_comp_ctx
);
4973 ssh2_pkt_init(ssh
, SSH2_MSG_IGNORE
);
4974 ssh2_pkt_addstring_start(ssh
);
4975 for (i
= 0; i
< stringlen
; i
++) {
4976 char c
= (char) random_byte();
4977 ssh2_pkt_addstring_data(ssh
, &c
, 1);
4979 ssh2_pkt_defer(ssh
);
4981 ssh_pkt_defersend(ssh
);
4982 logevent("Sent password");
4983 s
->type
= AUTH_TYPE_PASSWORD
;
4984 } else if (s
->method
== AUTH_KEYBOARD_INTERACTIVE
) {
4985 if (s
->curr_prompt
== 0) {
4986 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_INFO_RESPONSE
);
4987 ssh2_pkt_adduint32(ssh
, s
->num_prompts
);
4989 if (s
->need_pw
) { /* only add pw if we just got one! */
4990 ssh2_pkt_addstring(ssh
, s
->password
);
4991 memset(s
->password
, 0, sizeof(s
->password
));
4994 if (s
->curr_prompt
>= s
->num_prompts
) {
4998 * If there are prompts remaining, we set
4999 * `gotit' so that we won't attempt to get
5000 * another packet. Then we go back round the
5001 * loop and will end up retrieving another
5002 * prompt out of the existing packet. Funky or
5007 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
5009 c_write_str(ssh
, "No supported authentication methods"
5010 " left to try!\r\n");
5011 logevent("No supported authentications offered."
5013 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
5014 ssh2_pkt_adduint32(ssh
, SSH2_DISCONNECT_BY_APPLICATION
);
5015 ssh2_pkt_addstring(ssh
, "No supported authentication"
5016 " methods available");
5017 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5019 ssh
->state
= SSH_STATE_CLOSED
;
5023 } while (!s
->we_are_in
);
5026 * Now we're authenticated for the connection protocol. The
5027 * connection protocol will automatically have started at this
5028 * point; there's no need to send SERVICE_REQUEST.
5032 * So now create a channel with a session in it.
5034 ssh
->channels
= newtree234(ssh_channelcmp
);
5035 ssh
->mainchan
= smalloc(sizeof(struct ssh_channel
));
5036 ssh
->mainchan
->ssh
= ssh
;
5037 ssh
->mainchan
->localid
= alloc_channel_id(ssh
);
5038 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN
);
5039 ssh2_pkt_addstring(ssh
, "session");
5040 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->localid
);
5041 ssh
->mainchan
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5042 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->v
.v2
.locwindow
);/* our window size */
5043 ssh2_pkt_adduint32(ssh
, 0x4000UL
); /* our max pkt size */
5045 crWaitUntilV(ispkt
);
5046 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
5047 bombout((ssh
,"Server refused to open a session"));
5049 /* FIXME: error data comes back in FAILURE packet */
5051 if (ssh2_pkt_getuint32(ssh
) != ssh
->mainchan
->localid
) {
5052 bombout((ssh
,"Server's channel confirmation cited wrong channel"));
5055 ssh
->mainchan
->remoteid
= ssh2_pkt_getuint32(ssh
);
5056 ssh
->mainchan
->type
= CHAN_MAINSESSION
;
5057 ssh
->mainchan
->closes
= 0;
5058 ssh
->mainchan
->v
.v2
.remwindow
= ssh2_pkt_getuint32(ssh
);
5059 ssh
->mainchan
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32(ssh
);
5060 bufchain_init(&ssh
->mainchan
->v
.v2
.outbuffer
);
5061 add234(ssh
->channels
, ssh
->mainchan
);
5062 logevent("Opened channel for session");
5065 * Potentially enable X11 forwarding.
5067 if (cfg
.x11_forward
) {
5068 char proto
[20], data
[64];
5069 logevent("Requesting X11 forwarding");
5070 ssh
->x11auth
= x11_invent_auth(proto
, sizeof(proto
),
5071 data
, sizeof(data
));
5072 x11_get_real_auth(ssh
->x11auth
, cfg
.x11_display
);
5073 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5074 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
5075 ssh2_pkt_addstring(ssh
, "x11-req");
5076 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5077 ssh2_pkt_addbool(ssh
, 0); /* many connections */
5078 ssh2_pkt_addstring(ssh
, proto
);
5079 ssh2_pkt_addstring(ssh
, data
);
5080 ssh2_pkt_adduint32(ssh
, x11_get_screen_number(cfg
.x11_display
));
5084 crWaitUntilV(ispkt
);
5085 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5086 unsigned i
= ssh2_pkt_getuint32(ssh
);
5087 struct ssh_channel
*c
;
5088 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5090 continue; /* nonexistent channel */
5091 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5093 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5095 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5096 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5097 bombout((ssh
,"Unexpected response to X11 forwarding request:"
5098 " packet type %d", ssh
->pktin
.type
));
5101 logevent("X11 forwarding refused");
5103 logevent("X11 forwarding enabled");
5104 ssh
->X11_fwd_enabled
= TRUE
;
5109 * Enable port forwardings.
5114 int sport
,dport
,sserv
,dserv
;
5115 char sports
[256], dports
[256], saddr
[256], host
[256];
5117 ssh
->rportfwds
= newtree234(ssh_rportcmp_ssh2
);
5118 /* Add port forwardings. */
5119 ssh
->portfwd_strptr
= cfg
.portfwd
;
5120 while (*ssh
->portfwd_strptr
) {
5121 type
= *ssh
->portfwd_strptr
++;
5124 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= '\t') {
5125 if (*ssh
->portfwd_strptr
== ':') {
5127 * We've seen a colon in the middle of the
5128 * source port number. This means that
5129 * everything we've seen until now is the
5130 * source _address_, so we'll move it into
5131 * saddr and start sports from the beginning
5134 ssh
->portfwd_strptr
++;
5136 strcpy(saddr
, sports
);
5139 if (n
< 255) sports
[n
++] = *ssh
->portfwd_strptr
++;
5142 if (*ssh
->portfwd_strptr
== '\t')
5143 ssh
->portfwd_strptr
++;
5145 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= ':') {
5146 if (n
< 255) host
[n
++] = *ssh
->portfwd_strptr
++;
5149 if (*ssh
->portfwd_strptr
== ':')
5150 ssh
->portfwd_strptr
++;
5152 while (*ssh
->portfwd_strptr
) {
5153 if (n
< 255) dports
[n
++] = *ssh
->portfwd_strptr
++;
5156 ssh
->portfwd_strptr
++;
5157 dport
= atoi(dports
);
5161 dport
= net_service_lookup(dports
);
5163 logeventf(ssh
, "Service lookup failed for destination"
5164 " port \"%s\"", dports
);
5167 sport
= atoi(sports
);
5171 sport
= net_service_lookup(sports
);
5173 logeventf(ssh
, "Service lookup failed for source"
5174 " port \"%s\"", sports
);
5177 if (sport
&& dport
) {
5179 pfd_addforward(host
, dport
, *saddr ? saddr
: NULL
,
5181 logeventf(ssh
, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5182 " forwarding to %s:%.*s%.*s%d%.*s",
5183 (int)(*saddr?
strlen(saddr
):0), *saddr?saddr
:NULL
,
5184 (int)(*saddr?
1:0), ":",
5185 (int)(sserv ?
strlen(sports
) : 0), sports
,
5186 sserv
, "(", sport
, sserv
, ")",
5188 (int)(dserv ?
strlen(dports
) : 0), dports
,
5189 dserv
, "(", dport
, dserv
, ")");
5191 struct ssh_rportfwd
*pf
;
5192 pf
= smalloc(sizeof(*pf
));
5193 strcpy(pf
->dhost
, host
);
5196 if (add234(ssh
->rportfwds
, pf
) != pf
) {
5197 logeventf(ssh
, "Duplicate remote port forwarding"
5198 " to %s:%d", host
, dport
);
5201 logeventf(ssh
, "Requesting remote port "
5202 "%.*s%.*s%.*s%.*s%d%.*s"
5203 " forward to %s:%.*s%.*s%d%.*s",
5204 (int)(*saddr?
strlen(saddr
):0),
5206 (int)(*saddr?
1:0), ":",
5207 (int)(sserv ?
strlen(sports
) : 0), sports
,
5208 sserv
, "(", sport
, sserv
, ")",
5210 (int)(dserv ?
strlen(dports
) : 0), dports
,
5211 dserv
, "(", dport
, dserv
, ")");
5212 ssh2_pkt_init(ssh
, SSH2_MSG_GLOBAL_REQUEST
);
5213 ssh2_pkt_addstring(ssh
, "tcpip-forward");
5214 ssh2_pkt_addbool(ssh
, 1);/* want reply */
5216 ssh2_pkt_addstring(ssh
, saddr
);
5217 if (cfg
.rport_acceptall
)
5218 ssh2_pkt_addstring(ssh
, "0.0.0.0");
5220 ssh2_pkt_addstring(ssh
, "127.0.0.1");
5221 ssh2_pkt_adduint32(ssh
, sport
);
5225 crWaitUntilV(ispkt
);
5226 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5227 unsigned i
= ssh2_pkt_getuint32(ssh
);
5228 struct ssh_channel
*c
;
5229 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5231 continue;/* nonexistent channel */
5232 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5234 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5236 if (ssh
->pktin
.type
!= SSH2_MSG_REQUEST_SUCCESS
) {
5237 if (ssh
->pktin
.type
!= SSH2_MSG_REQUEST_FAILURE
) {
5238 bombout((ssh
,"Unexpected response to port "
5239 "forwarding request: packet type %d",
5243 logevent("Server refused this port forwarding");
5245 logevent("Remote port forwarding enabled");
5254 * Potentially enable agent forwarding.
5256 if (cfg
.agentfwd
&& agent_exists()) {
5257 logevent("Requesting OpenSSH-style agent forwarding");
5258 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5259 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
5260 ssh2_pkt_addstring(ssh
, "auth-agent-req@openssh.com");
5261 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5265 crWaitUntilV(ispkt
);
5266 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5267 unsigned i
= ssh2_pkt_getuint32(ssh
);
5268 struct ssh_channel
*c
;
5269 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5271 continue; /* nonexistent channel */
5272 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5274 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5276 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5277 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5278 bombout((ssh
,"Unexpected response to agent forwarding request:"
5279 " packet type %d", ssh
->pktin
.type
));
5282 logevent("Agent forwarding refused");
5284 logevent("Agent forwarding enabled");
5285 ssh
->agentfwd_enabled
= TRUE
;
5290 * Now allocate a pty for the session.
5293 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5294 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
); /* recipient channel */
5295 ssh2_pkt_addstring(ssh
, "pty-req");
5296 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5297 ssh2_pkt_addstring(ssh
, cfg
.termtype
);
5298 ssh2_pkt_adduint32(ssh
, ssh
->term_width
);
5299 ssh2_pkt_adduint32(ssh
, ssh
->term_height
);
5300 ssh2_pkt_adduint32(ssh
, 0); /* pixel width */
5301 ssh2_pkt_adduint32(ssh
, 0); /* pixel height */
5302 ssh2_pkt_addstring_start(ssh
);
5303 ssh2_pkt_addstring_data(ssh
, "\0", 1); /* TTY_OP_END, no special options */
5305 ssh
->state
= SSH_STATE_INTERMED
;
5308 crWaitUntilV(ispkt
);
5309 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5310 unsigned i
= ssh2_pkt_getuint32(ssh
);
5311 struct ssh_channel
*c
;
5312 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5314 continue; /* nonexistent channel */
5315 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5317 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5319 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5320 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5321 bombout((ssh
,"Unexpected response to pty request:"
5322 " packet type %d", ssh
->pktin
.type
));
5325 c_write_str(ssh
, "Server refused to allocate pty\r\n");
5326 ssh
->editing
= ssh
->echoing
= 1;
5328 logevent("Allocated pty");
5331 ssh
->editing
= ssh
->echoing
= 1;
5335 * Start a shell or a remote command. We may have to attempt
5336 * this twice if the config data has provided a second choice
5343 if (ssh
->fallback_cmd
) {
5344 subsys
= cfg
.ssh_subsys2
;
5345 cmd
= cfg
.remote_cmd_ptr2
;
5347 subsys
= cfg
.ssh_subsys
;
5348 cmd
= cfg
.remote_cmd_ptr
;
5351 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5352 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
); /* recipient channel */
5354 ssh2_pkt_addstring(ssh
, "subsystem");
5355 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5356 ssh2_pkt_addstring(ssh
, cmd
);
5358 ssh2_pkt_addstring(ssh
, "exec");
5359 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5360 ssh2_pkt_addstring(ssh
, cmd
);
5362 ssh2_pkt_addstring(ssh
, "shell");
5363 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5367 crWaitUntilV(ispkt
);
5368 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5369 unsigned i
= ssh2_pkt_getuint32(ssh
);
5370 struct ssh_channel
*c
;
5371 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5373 continue; /* nonexistent channel */
5374 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5376 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5377 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5378 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5379 bombout((ssh
,"Unexpected response to shell/command request:"
5380 " packet type %d", ssh
->pktin
.type
));
5384 * We failed to start the command. If this is the
5385 * fallback command, we really are finished; if it's
5386 * not, and if the fallback command exists, try falling
5387 * back to it before complaining.
5389 if (!ssh
->fallback_cmd
&& cfg
.remote_cmd_ptr2
!= NULL
) {
5390 logevent("Primary command failed; attempting fallback");
5391 ssh
->fallback_cmd
= TRUE
;
5394 bombout((ssh
,"Server refused to start a shell/command"));
5397 logevent("Started a shell/command");
5402 ssh
->state
= SSH_STATE_SESSION
;
5403 if (ssh
->size_needed
)
5404 ssh_size(ssh
, ssh
->term_width
, ssh
->term_height
);
5405 if (ssh
->eof_needed
)
5406 ssh_special(ssh
, TS_EOF
);
5412 ldisc_send(ssh
->ldisc
, NULL
, 0, 0);/* cause ldisc to notice changes */
5416 s
->try_send
= FALSE
;
5418 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
5419 ssh
->pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
5422 unsigned i
= ssh2_pkt_getuint32(ssh
);
5423 struct ssh_channel
*c
;
5424 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5426 continue; /* nonexistent channel */
5427 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
5428 ssh2_pkt_getuint32(ssh
) != SSH2_EXTENDED_DATA_STDERR
)
5429 continue; /* extended but not stderr */
5430 ssh2_pkt_getstring(ssh
, &data
, &length
);
5433 c
->v
.v2
.locwindow
-= length
;
5435 case CHAN_MAINSESSION
:
5437 from_backend(ssh
->frontend
, ssh
->pktin
.type
==
5438 SSH2_MSG_CHANNEL_EXTENDED_DATA
,
5442 bufsize
= x11_send(c
->u
.x11
.s
, data
, length
);
5445 bufsize
= pfd_send(c
->u
.pfd
.s
, data
, length
);
5448 while (length
> 0) {
5449 if (c
->u
.a
.lensofar
< 4) {
5450 int l
= min(4 - c
->u
.a
.lensofar
, length
);
5451 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
,
5455 c
->u
.a
.lensofar
+= l
;
5457 if (c
->u
.a
.lensofar
== 4) {
5459 4 + GET_32BIT(c
->u
.a
.msglen
);
5460 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
5461 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
5463 if (c
->u
.a
.lensofar
>= 4 && length
> 0) {
5465 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
5467 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
,
5471 c
->u
.a
.lensofar
+= l
;
5473 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
5474 void *reply
, *sentreply
;
5476 agent_query(c
->u
.a
.message
,
5477 c
->u
.a
.totallen
, &reply
,
5482 /* Fake SSH_AGENT_FAILURE. */
5483 sentreply
= "\0\0\0\1\5";
5486 ssh2_add_channel_data(c
, sentreply
, replylen
);
5490 sfree(c
->u
.a
.message
);
5491 c
->u
.a
.lensofar
= 0;
5498 * If we are not buffering too much data,
5499 * enlarge the window again at the remote side.
5501 if (bufsize
< OUR_V2_WINSIZE
)
5502 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
5504 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_EOF
) {
5505 unsigned i
= ssh2_pkt_getuint32(ssh
);
5506 struct ssh_channel
*c
;
5508 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5510 continue; /* nonexistent channel */
5512 if (c
->type
== CHAN_X11
) {
5514 * Remote EOF on an X11 channel means we should
5515 * wrap up and close the channel ourselves.
5517 x11_close(c
->u
.x11
.s
);
5519 } else if (c
->type
== CHAN_AGENT
) {
5521 } else if (c
->type
== CHAN_SOCKDATA
) {
5522 pfd_close(c
->u
.pfd
.s
);
5525 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_CLOSE
) {
5526 unsigned i
= ssh2_pkt_getuint32(ssh
);
5527 struct ssh_channel
*c
;
5529 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5530 if (!c
|| ((int)c
->remoteid
) == -1) {
5531 bombout((ssh
,"Received CHANNEL_CLOSE for %s channel %d\n",
5532 c ?
"half-open" : "nonexistent", i
));
5534 /* Do pre-close processing on the channel. */
5536 case CHAN_MAINSESSION
:
5537 break; /* nothing to see here, move along */
5539 if (c
->u
.x11
.s
!= NULL
)
5540 x11_close(c
->u
.x11
.s
);
5547 if (c
->u
.pfd
.s
!= NULL
)
5548 pfd_close(c
->u
.pfd
.s
);
5552 if (c
->closes
== 0) {
5553 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_CLOSE
);
5554 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5557 del234(ssh
->channels
, c
);
5558 bufchain_clear(&c
->v
.v2
.outbuffer
);
5562 * See if that was the last channel left open.
5564 if (count234(ssh
->channels
) == 0) {
5567 * We used to send SSH_MSG_DISCONNECT here,
5568 * because I'd believed that _every_ conforming
5569 * SSH2 connection had to end with a disconnect
5570 * being sent by at least one side; apparently
5571 * I was wrong and it's perfectly OK to
5572 * unceremoniously slam the connection shut
5573 * when you're done, and indeed OpenSSH feels
5574 * this is more polite than sending a
5575 * DISCONNECT. So now we don't.
5577 logevent("All channels closed. Disconnecting");
5578 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
5579 ssh2_pkt_adduint32(ssh
, SSH2_DISCONNECT_BY_APPLICATION
);
5580 ssh2_pkt_addstring(ssh
, "All open channels closed");
5581 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5584 ssh
->state
= SSH_STATE_CLOSED
;
5587 continue; /* remote sends close; ignore (FIXME) */
5588 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5589 unsigned i
= ssh2_pkt_getuint32(ssh
);
5590 struct ssh_channel
*c
;
5591 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5593 continue; /* nonexistent channel */
5594 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5596 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
5597 unsigned i
= ssh2_pkt_getuint32(ssh
);
5598 struct ssh_channel
*c
;
5599 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5601 continue; /* nonexistent channel */
5602 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
5603 continue; /* dunno why they're confirming this */
5604 c
->remoteid
= ssh2_pkt_getuint32(ssh
);
5605 c
->type
= CHAN_SOCKDATA
;
5606 c
->v
.v2
.remwindow
= ssh2_pkt_getuint32(ssh
);
5607 c
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32(ssh
);
5609 pfd_confirm(c
->u
.pfd
.s
);
5612 * We have a pending close on this channel,
5613 * which we decided on before the server acked
5614 * the channel open. So now we know the
5615 * remoteid, we can close it again.
5617 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_CLOSE
);
5618 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5621 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_OPEN_FAILURE
) {
5622 unsigned i
= ssh2_pkt_getuint32(ssh
);
5623 struct ssh_channel
*c
;
5624 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5626 continue; /* nonexistent channel */
5627 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
5628 continue; /* dunno why they're failing this */
5630 logevent("Forwarded connection refused by server");
5632 pfd_close(c
->u
.pfd
.s
);
5634 del234(ssh
->channels
, c
);
5636 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_REQUEST
) {
5639 int typelen
, want_reply
;
5640 struct ssh_channel
*c
;
5642 localid
= ssh2_pkt_getuint32(ssh
);
5643 ssh2_pkt_getstring(ssh
, &type
, &typelen
);
5644 want_reply
= ssh2_pkt_getbool(ssh
);
5647 * First, check that the channel exists. Otherwise,
5648 * we can instantly disconnect with a rude message.
5650 c
= find234(ssh
->channels
, &localid
, ssh_channelfind
);
5653 sprintf(buf
, "Received channel request for nonexistent"
5654 " channel %d", localid
);
5656 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
5657 ssh2_pkt_adduint32(ssh
, SSH2_DISCONNECT_BY_APPLICATION
);
5658 ssh2_pkt_addstring(ssh
, buf
);
5659 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5661 connection_fatal("%s", buf
);
5662 ssh
->state
= SSH_STATE_CLOSED
;
5667 * Having got the channel number, we now look at
5668 * the request type string to see if it's something
5671 if (typelen
== 11 && !memcmp(type
, "exit-status", 11) &&
5672 c
== ssh
->mainchan
) {
5673 /* We recognise "exit-status" on the primary channel. */
5675 ssh
->exitcode
= ssh2_pkt_getuint32(ssh
);
5676 sprintf(buf
, "Server sent command exit status %d",
5680 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_SUCCESS
);
5681 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5686 * This is a channel request we don't know
5687 * about, so we now either ignore the request
5688 * or respond with CHANNEL_FAILURE, depending
5692 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_FAILURE
);
5693 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5697 } else if (ssh
->pktin
.type
== SSH2_MSG_GLOBAL_REQUEST
) {
5699 int typelen
, want_reply
;
5701 ssh2_pkt_getstring(ssh
, &type
, &typelen
);
5702 want_reply
= ssh2_pkt_getbool(ssh
);
5705 * We currently don't support any global requests
5706 * at all, so we either ignore the request or
5707 * respond with REQUEST_FAILURE, depending on
5711 ssh2_pkt_init(ssh
, SSH2_MSG_REQUEST_FAILURE
);
5714 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_OPEN
) {
5718 struct ssh_channel
*c
;
5719 unsigned remid
, winsize
, pktsize
;
5720 ssh2_pkt_getstring(ssh
, &type
, &typelen
);
5721 c
= smalloc(sizeof(struct ssh_channel
));
5724 remid
= ssh2_pkt_getuint32(ssh
);
5725 winsize
= ssh2_pkt_getuint32(ssh
);
5726 pktsize
= ssh2_pkt_getuint32(ssh
);
5728 if (typelen
== 3 && !memcmp(type
, "x11", 3)) {
5729 if (!ssh
->X11_fwd_enabled
)
5730 error
= "X11 forwarding is not enabled";
5731 else if (x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
,
5732 ssh
->x11auth
) != NULL
) {
5733 error
= "Unable to open an X11 connection";
5737 } else if (typelen
== 15 &&
5738 !memcmp(type
, "forwarded-tcpip", 15)) {
5739 struct ssh_rportfwd pf
, *realpf
;
5742 ssh2_pkt_getstring(ssh
, &dummy
, &dummylen
);/* skip address */
5743 pf
.sport
= ssh2_pkt_getuint32(ssh
);
5744 realpf
= find234(ssh
->rportfwds
, &pf
, NULL
);
5745 if (realpf
== NULL
) {
5746 error
= "Remote port is not recognised";
5748 char *e
= pfd_newconnect(&c
->u
.pfd
.s
, realpf
->dhost
,
5750 logeventf(ssh
, "Received remote port open request"
5751 " for %s:%d", realpf
->dhost
, realpf
->dport
);
5753 logeventf(ssh
, "Port open failed: %s", e
);
5754 error
= "Port open failed";
5756 logevent("Forwarded port opened successfully");
5757 c
->type
= CHAN_SOCKDATA
;
5760 } else if (typelen
== 22 &&
5761 !memcmp(type
, "auth-agent@openssh.com", 3)) {
5762 if (!ssh
->agentfwd_enabled
)
5763 error
= "Agent forwarding is not enabled";
5765 c
->type
= CHAN_AGENT
; /* identify channel type */
5766 c
->u
.a
.lensofar
= 0;
5769 error
= "Unsupported channel type requested";
5772 c
->remoteid
= remid
;
5774 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN_FAILURE
);
5775 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5776 ssh2_pkt_adduint32(ssh
, SSH2_OPEN_CONNECT_FAILED
);
5777 ssh2_pkt_addstring(ssh
, error
);
5778 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5782 c
->localid
= alloc_channel_id(ssh
);
5784 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5785 c
->v
.v2
.remwindow
= winsize
;
5786 c
->v
.v2
.remmaxpkt
= pktsize
;
5787 bufchain_init(&c
->v
.v2
.outbuffer
);
5788 add234(ssh
->channels
, c
);
5789 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
5790 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5791 ssh2_pkt_adduint32(ssh
, c
->localid
);
5792 ssh2_pkt_adduint32(ssh
, c
->v
.v2
.locwindow
);
5793 ssh2_pkt_adduint32(ssh
, 0x4000UL
); /* our max pkt size */
5797 bombout((ssh
,"Strange packet received: type %d", ssh
->pktin
.type
));
5802 * We have spare data. Add it to the channel buffer.
5804 ssh2_add_channel_data(ssh
->mainchan
, (char *)in
, inlen
);
5809 struct ssh_channel
*c
;
5811 * Try to send data on all channels if we can.
5813 for (i
= 0; NULL
!= (c
= index234(ssh
->channels
, i
)); i
++) {
5814 int bufsize
= ssh2_try_send(c
);
5817 case CHAN_MAINSESSION
:
5818 /* stdin need not receive an unthrottle
5819 * notification since it will be polled */
5822 x11_unthrottle(c
->u
.x11
.s
);
5825 /* agent sockets are request/response and need no
5826 * buffer management */
5829 pfd_unthrottle(c
->u
.pfd
.s
);
5841 * Handle the top-level SSH2 protocol.
5843 static void ssh2_protocol(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
5845 if (do_ssh2_transport(ssh
, in
, inlen
, ispkt
) == 0)
5847 do_ssh2_authconn(ssh
, in
, inlen
, ispkt
);
5851 * Called to set up the connection.
5853 * Returns an error message, or NULL on success.
5855 static char *ssh_init(void *frontend_handle
, void **backend_handle
,
5856 char *host
, int port
, char **realhost
, int nodelay
)
5861 ssh
= smalloc(sizeof(*ssh
));
5864 ssh
->v1_cipher_ctx
= NULL
;
5865 ssh
->crcda_ctx
= NULL
;
5866 ssh
->cscipher
= NULL
;
5867 ssh
->cs_cipher_ctx
= NULL
;
5868 ssh
->sccipher
= NULL
;
5869 ssh
->sc_cipher_ctx
= NULL
;
5871 ssh
->cs_mac_ctx
= NULL
;
5873 ssh
->sc_mac_ctx
= NULL
;
5875 ssh
->cs_comp_ctx
= NULL
;
5877 ssh
->sc_comp_ctx
= NULL
;
5879 ssh
->hostkey
= NULL
;
5881 ssh
->state
= SSH_STATE_PREPACKET
;
5882 ssh
->size_needed
= FALSE
;
5883 ssh
->eof_needed
= FALSE
;
5887 static const struct Packet empty
= { 0, 0, NULL
, NULL
, 0 };
5888 ssh
->pktin
= ssh
->pktout
= empty
;
5890 ssh
->deferred_send_data
= NULL
;
5891 ssh
->deferred_len
= 0;
5892 ssh
->deferred_size
= 0;
5893 ssh
->fallback_cmd
= 0;
5895 ssh
->x11auth
= NULL
;
5896 ssh
->v1_compressing
= FALSE
;
5897 ssh
->v2_outgoing_sequence
= 0;
5898 ssh
->ssh1_rdpkt_crstate
= 0;
5899 ssh
->ssh2_rdpkt_crstate
= 0;
5900 ssh
->do_ssh_init_crstate
= 0;
5901 ssh
->ssh_gotdata_crstate
= 0;
5902 ssh
->ssh1_protocol_crstate
= 0;
5903 ssh
->do_ssh1_login_crstate
= 0;
5904 ssh
->do_ssh2_transport_crstate
= 0;
5905 ssh
->do_ssh2_authconn_crstate
= 0;
5906 ssh
->do_ssh_init_state
= NULL
;
5907 ssh
->do_ssh1_login_state
= NULL
;
5908 ssh
->do_ssh2_transport_state
= NULL
;
5909 ssh
->do_ssh2_authconn_state
= NULL
;
5910 ssh
->mainchan
= NULL
;
5911 ssh
->throttled_all
= 0;
5912 ssh
->v1_stdout_throttling
= 0;
5914 *backend_handle
= ssh
;
5917 if (crypto_startup() == 0)
5918 return "Microsoft high encryption pack not installed!";
5921 ssh
->frontend
= frontend_handle
;
5922 ssh
->term_width
= cfg
.width
;
5923 ssh
->term_height
= cfg
.height
;
5928 ssh
->v1_throttle_count
= 0;
5929 ssh
->overall_bufsize
= 0;
5930 ssh
->fallback_cmd
= 0;
5932 ssh
->protocol
= NULL
;
5934 p
= connect_to_host(ssh
, host
, port
, realhost
, nodelay
);
5942 * Called to send data down the Telnet connection.
5944 static int ssh_send(void *handle
, char *buf
, int len
)
5946 Ssh ssh
= (Ssh
) handle
;
5948 if (ssh
== NULL
|| ssh
->s
== NULL
|| ssh
->protocol
== NULL
)
5951 ssh
->protocol(ssh
, (unsigned char *)buf
, len
, 0);
5953 return ssh_sendbuffer(ssh
);
5957 * Called to query the current amount of buffered stdin data.
5959 static int ssh_sendbuffer(void *handle
)
5961 Ssh ssh
= (Ssh
) handle
;
5964 if (ssh
== NULL
|| ssh
->s
== NULL
|| ssh
->protocol
== NULL
)
5968 * If the SSH socket itself has backed up, add the total backup
5969 * size on that to any individual buffer on the stdin channel.
5972 if (ssh
->throttled_all
)
5973 override_value
= ssh
->overall_bufsize
;
5975 if (ssh
->version
== 1) {
5976 return override_value
;
5977 } else if (ssh
->version
== 2) {
5978 if (!ssh
->mainchan
|| ssh
->mainchan
->closes
> 0)
5979 return override_value
;
5981 return (override_value
+
5982 bufchain_size(&ssh
->mainchan
->v
.v2
.outbuffer
));
5989 * Called to set the size of the window from SSH's POV.
5991 static void ssh_size(void *handle
, int width
, int height
)
5993 Ssh ssh
= (Ssh
) handle
;
5995 ssh
->term_width
= width
;
5996 ssh
->term_height
= height
;
5998 switch (ssh
->state
) {
5999 case SSH_STATE_BEFORE_SIZE
:
6000 case SSH_STATE_PREPACKET
:
6001 case SSH_STATE_CLOSED
:
6002 break; /* do nothing */
6003 case SSH_STATE_INTERMED
:
6004 ssh
->size_needed
= TRUE
; /* buffer for later */
6006 case SSH_STATE_SESSION
:
6008 if (ssh
->version
== 1) {
6009 send_packet(ssh
, SSH1_CMSG_WINDOW_SIZE
,
6010 PKT_INT
, ssh
->term_height
,
6011 PKT_INT
, ssh
->term_width
,
6012 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
6014 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
6015 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
6016 ssh2_pkt_addstring(ssh
, "window-change");
6017 ssh2_pkt_addbool(ssh
, 0);
6018 ssh2_pkt_adduint32(ssh
, ssh
->term_width
);
6019 ssh2_pkt_adduint32(ssh
, ssh
->term_height
);
6020 ssh2_pkt_adduint32(ssh
, 0);
6021 ssh2_pkt_adduint32(ssh
, 0);
6030 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6031 * can send an EOF and collect resulting output (e.g. `plink
6034 static void ssh_special(void *handle
, Telnet_Special code
)
6036 Ssh ssh
= (Ssh
) handle
;
6038 if (code
== TS_EOF
) {
6039 if (ssh
->state
!= SSH_STATE_SESSION
) {
6041 * Buffer the EOF in case we are pre-SESSION, so we can
6042 * send it as soon as we reach SESSION.
6045 ssh
->eof_needed
= TRUE
;
6048 if (ssh
->version
== 1) {
6049 send_packet(ssh
, SSH1_CMSG_EOF
, PKT_END
);
6051 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_EOF
);
6052 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
6055 logevent("Sent EOF message");
6056 } else if (code
== TS_PING
) {
6057 if (ssh
->state
== SSH_STATE_CLOSED
6058 || ssh
->state
== SSH_STATE_PREPACKET
) return;
6059 if (ssh
->version
== 1) {
6060 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
))
6061 send_packet(ssh
, SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
6063 ssh2_pkt_init(ssh
, SSH2_MSG_IGNORE
);
6064 ssh2_pkt_addstring_start(ssh
);
6072 void *new_sock_channel(void *handle
, Socket s
)
6074 Ssh ssh
= (Ssh
) handle
;
6075 struct ssh_channel
*c
;
6076 c
= smalloc(sizeof(struct ssh_channel
));
6080 c
->remoteid
= -1; /* to be set when open confirmed */
6081 c
->localid
= alloc_channel_id(ssh
);
6083 c
->type
= CHAN_SOCKDATA_DORMANT
;/* identify channel type */
6085 bufchain_init(&c
->v
.v2
.outbuffer
);
6086 add234(ssh
->channels
, c
);
6092 * This is called when stdout/stderr (the entity to which
6093 * from_backend sends data) manages to clear some backlog.
6095 static void ssh_unthrottle(void *handle
, int bufsize
)
6097 Ssh ssh
= (Ssh
) handle
;
6098 if (ssh
->version
== 1) {
6099 if (ssh
->v1_stdout_throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
6100 ssh
->v1_stdout_throttling
= 0;
6101 ssh1_throttle(ssh
, -1);
6104 if (ssh
->mainchan
&& ssh
->mainchan
->closes
== 0)
6105 ssh2_set_window(ssh
->mainchan
, OUR_V2_WINSIZE
- bufsize
);
6109 void ssh_send_port_open(void *channel
, char *hostname
, int port
, char *org
)
6111 struct ssh_channel
*c
= (struct ssh_channel
*)channel
;
6114 logeventf(ssh
, "Opening forwarded connection to %s:%d", hostname
, port
);
6116 if (ssh
->version
== 1) {
6117 send_packet(ssh
, SSH1_MSG_PORT_OPEN
,
6118 PKT_INT
, c
->localid
,
6121 //PKT_STR, <org:orgport>,
6124 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN
);
6125 ssh2_pkt_addstring(ssh
, "direct-tcpip");
6126 ssh2_pkt_adduint32(ssh
, c
->localid
);
6127 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
6128 ssh2_pkt_adduint32(ssh
, c
->v
.v2
.locwindow
);/* our window size */
6129 ssh2_pkt_adduint32(ssh
, 0x4000UL
); /* our max pkt size */
6130 ssh2_pkt_addstring(ssh
, hostname
);
6131 ssh2_pkt_adduint32(ssh
, port
);
6133 * We make up values for the originator data; partly it's
6134 * too much hassle to keep track, and partly I'm not
6135 * convinced the server should be told details like that
6136 * about my local network configuration.
6138 ssh2_pkt_addstring(ssh
, "client-side-connection");
6139 ssh2_pkt_adduint32(ssh
, 0);
6145 static Socket
ssh_socket(void *handle
)
6147 Ssh ssh
= (Ssh
) handle
;
6151 static int ssh_sendok(void *handle
)
6153 Ssh ssh
= (Ssh
) handle
;
6154 return ssh
->send_ok
;
6157 static int ssh_ldisc(void *handle
, int option
)
6159 Ssh ssh
= (Ssh
) handle
;
6160 if (option
== LD_ECHO
)
6161 return ssh
->echoing
;
6162 if (option
== LD_EDIT
)
6163 return ssh
->editing
;
6167 static void ssh_provide_ldisc(void *handle
, void *ldisc
)
6169 Ssh ssh
= (Ssh
) handle
;
6173 static void ssh_provide_logctx(void *handle
, void *logctx
)
6175 Ssh ssh
= (Ssh
) handle
;
6176 ssh
->logctx
= logctx
;
6179 static int ssh_return_exitcode(void *handle
)
6181 Ssh ssh
= (Ssh
) handle
;
6182 return ssh
->exitcode
;
6186 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6187 * that fails. This variable is the means by which scp.c can reach
6188 * into the SSH code and find out which one it got.
6190 extern int ssh_fallback_cmd(void *handle
)
6192 Ssh ssh
= (Ssh
) handle
;
6193 return ssh
->fallback_cmd
;
6196 Backend ssh_backend
= {
6203 ssh_return_exitcode
,