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 * We maintain a full _copy_ of a Config structure here, not
626 * merely a pointer to it. That way, when we're passed a new
627 * one for reconfiguration, we can check the differences and
628 * potentially reconfigure port forwardings etc in mid-session.
633 #define logevent(s) logevent(ssh->frontend, s)
635 /* logevent, only printf-formatted. */
636 static void logeventf(Ssh ssh
, char *fmt
, ...)
642 buf
= dupvprintf(fmt
, ap
);
648 #define bombout(msg) ( ssh->state = SSH_STATE_CLOSED, \
649 (ssh->s ? sk_close(ssh->s), ssh->s = NULL : 0), \
650 logeventf msg, connection_fatal msg )
652 static int ssh_channelcmp(void *av
, void *bv
)
654 struct ssh_channel
*a
= (struct ssh_channel
*) av
;
655 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
656 if (a
->localid
< b
->localid
)
658 if (a
->localid
> b
->localid
)
662 static int ssh_channelfind(void *av
, void *bv
)
664 unsigned *a
= (unsigned *) av
;
665 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
673 static int ssh_rportcmp_ssh1(void *av
, void *bv
)
675 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
676 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
678 if ( (i
= strcmp(a
->dhost
, b
->dhost
)) != 0)
679 return i
< 0 ?
-1 : +1;
680 if (a
->dport
> b
->dport
)
682 if (a
->dport
< b
->dport
)
687 static int ssh_rportcmp_ssh2(void *av
, void *bv
)
689 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
690 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
692 if (a
->sport
> b
->sport
)
694 if (a
->sport
< b
->sport
)
699 static int alloc_channel_id(Ssh ssh
)
701 const unsigned CHANNEL_NUMBER_OFFSET
= 256;
702 unsigned low
, high
, mid
;
704 struct ssh_channel
*c
;
707 * First-fit allocation of channel numbers: always pick the
708 * lowest unused one. To do this, binary-search using the
709 * counted B-tree to find the largest channel ID which is in a
710 * contiguous sequence from the beginning. (Precisely
711 * everything in that sequence must have ID equal to its tree
712 * index plus CHANNEL_NUMBER_OFFSET.)
714 tsize
= count234(ssh
->channels
);
718 while (high
- low
> 1) {
719 mid
= (high
+ low
) / 2;
720 c
= index234(ssh
->channels
, mid
);
721 if (c
->localid
== mid
+ CHANNEL_NUMBER_OFFSET
)
722 low
= mid
; /* this one is fine */
724 high
= mid
; /* this one is past it */
727 * Now low points to either -1, or the tree index of the
728 * largest ID in the initial sequence.
731 unsigned i
= low
+ 1 + CHANNEL_NUMBER_OFFSET
;
732 assert(NULL
== find234(ssh
->channels
, &i
, ssh_channelfind
));
734 return low
+ 1 + CHANNEL_NUMBER_OFFSET
;
737 static void c_write(Ssh ssh
, char *buf
, int len
)
739 if ((flags
& FLAG_STDERR
)) {
741 for (i
= 0; i
< len
; i
++)
743 fputc(buf
[i
], stderr
);
746 from_backend(ssh
->frontend
, 1, buf
, len
);
749 static void c_write_untrusted(Ssh ssh
, char *buf
, int len
)
752 for (i
= 0; i
< len
; i
++) {
754 c_write(ssh
, "\r\n", 2);
755 else if ((buf
[i
] & 0x60) || (buf
[i
] == '\r'))
756 c_write(ssh
, buf
+ i
, 1);
760 static void c_write_str(Ssh ssh
, char *buf
)
762 c_write(ssh
, buf
, strlen(buf
));
766 * Collect incoming data in the incoming packet buffer.
767 * Decipher and verify the packet when it is completely read.
768 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
769 * Update the *data and *datalen variables.
770 * Return the additional nr of bytes needed, or 0 when
771 * a complete packet is available.
773 static int ssh1_rdpkt(Ssh ssh
, unsigned char **data
, int *datalen
)
775 struct rdpkt1_state_tag
*st
= &ssh
->rdpkt1_state
;
777 crBegin(ssh
->ssh1_rdpkt_crstate
);
782 ssh
->pktin
.length
= 0;
784 for (st
->i
= st
->len
= 0; st
->i
< 4; st
->i
++) {
785 while ((*datalen
) == 0)
787 st
->len
= (st
->len
<< 8) + **data
;
788 (*data
)++, (*datalen
)--;
791 st
->pad
= 8 - (st
->len
% 8);
792 st
->biglen
= st
->len
+ st
->pad
;
793 ssh
->pktin
.length
= st
->len
- 5;
795 if (ssh
->pktin
.maxlen
< st
->biglen
) {
796 ssh
->pktin
.maxlen
= st
->biglen
;
797 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
, st
->biglen
+ APIEXTRA
);
800 st
->to_read
= st
->biglen
;
801 st
->p
= ssh
->pktin
.data
;
802 while (st
->to_read
> 0) {
803 st
->chunk
= st
->to_read
;
804 while ((*datalen
) == 0)
805 crReturn(st
->to_read
);
806 if (st
->chunk
> (*datalen
))
807 st
->chunk
= (*datalen
);
808 memcpy(st
->p
, *data
, st
->chunk
);
810 *datalen
-= st
->chunk
;
812 st
->to_read
-= st
->chunk
;
815 if (ssh
->cipher
&& detect_attack(ssh
->crcda_ctx
, ssh
->pktin
.data
,
817 bombout((ssh
,"Network attack (CRC compensation) detected!"));
822 ssh
->cipher
->decrypt(ssh
->v1_cipher_ctx
, ssh
->pktin
.data
, st
->biglen
);
824 st
->realcrc
= crc32(ssh
->pktin
.data
, st
->biglen
- 4);
825 st
->gotcrc
= GET_32BIT(ssh
->pktin
.data
+ st
->biglen
- 4);
826 if (st
->gotcrc
!= st
->realcrc
) {
827 bombout((ssh
,"Incorrect CRC received on packet"));
831 ssh
->pktin
.body
= ssh
->pktin
.data
+ st
->pad
+ 1;
833 if (ssh
->v1_compressing
) {
834 unsigned char *decompblk
;
836 zlib_decompress_block(ssh
->sc_comp_ctx
,
837 ssh
->pktin
.body
- 1, ssh
->pktin
.length
+ 1,
838 &decompblk
, &decomplen
);
840 if (ssh
->pktin
.maxlen
< st
->pad
+ decomplen
) {
841 ssh
->pktin
.maxlen
= st
->pad
+ decomplen
;
842 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
,
843 ssh
->pktin
.maxlen
+ APIEXTRA
);
844 ssh
->pktin
.body
= ssh
->pktin
.data
+ st
->pad
+ 1;
847 memcpy(ssh
->pktin
.body
- 1, decompblk
, decomplen
);
849 ssh
->pktin
.length
= decomplen
- 1;
852 ssh
->pktin
.type
= ssh
->pktin
.body
[-1];
855 log_packet(ssh
->logctx
,
856 PKT_INCOMING
, ssh
->pktin
.type
,
857 ssh1_pkt_type(ssh
->pktin
.type
),
858 ssh
->pktin
.body
, ssh
->pktin
.length
);
860 if (ssh
->pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
861 ssh
->pktin
.type
== SSH1_SMSG_STDERR_DATA
||
862 ssh
->pktin
.type
== SSH1_MSG_DEBUG
||
863 ssh
->pktin
.type
== SSH1_SMSG_AUTH_TIS_CHALLENGE
||
864 ssh
->pktin
.type
== SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
865 long stringlen
= GET_32BIT(ssh
->pktin
.body
);
866 if (stringlen
+ 4 != ssh
->pktin
.length
) {
867 bombout((ssh
,"Received data packet with bogus string length"));
872 if (ssh
->pktin
.type
== SSH1_MSG_DEBUG
) {
873 /* log debug message */
875 int stringlen
= GET_32BIT(ssh
->pktin
.body
);
876 strcpy(buf
, "Remote debug message: ");
879 memcpy(buf
+ 8, ssh
->pktin
.body
+ 4, stringlen
);
880 buf
[8 + stringlen
] = '\0';
883 } else if (ssh
->pktin
.type
== SSH1_MSG_IGNORE
) {
888 if (ssh
->pktin
.type
== SSH1_MSG_DISCONNECT
) {
889 /* log reason code in disconnect message */
891 unsigned msglen
= GET_32BIT(ssh
->pktin
.body
);
893 strcpy(buf
, "Remote sent disconnect: ");
894 nowlen
= strlen(buf
);
895 if (msglen
> sizeof(buf
) - nowlen
- 1)
896 msglen
= sizeof(buf
) - nowlen
- 1;
897 memcpy(buf
+ nowlen
, ssh
->pktin
.body
+ 4, msglen
);
898 buf
[nowlen
+ msglen
] = '\0';
899 /* logevent(buf); (this is now done within the bombout macro) */
900 bombout((ssh
,"Server sent disconnect message:\n\"%s\"", buf
+nowlen
));
907 static int ssh2_rdpkt(Ssh ssh
, unsigned char **data
, int *datalen
)
909 struct rdpkt2_state_tag
*st
= &ssh
->rdpkt2_state
;
911 crBegin(ssh
->ssh2_rdpkt_crstate
);
915 ssh
->pktin
.length
= 0;
917 st
->cipherblk
= ssh
->sccipher
->blksize
;
920 if (st
->cipherblk
< 8)
923 if (ssh
->pktin
.maxlen
< st
->cipherblk
) {
924 ssh
->pktin
.maxlen
= st
->cipherblk
;
925 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
, st
->cipherblk
+ APIEXTRA
);
929 * Acquire and decrypt the first block of the packet. This will
930 * contain the length and padding details.
932 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
933 while ((*datalen
) == 0)
934 crReturn(st
->cipherblk
- st
->i
);
935 ssh
->pktin
.data
[st
->i
] = *(*data
)++;
940 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
941 ssh
->pktin
.data
, st
->cipherblk
);
944 * Now get the length and padding figures.
946 st
->len
= GET_32BIT(ssh
->pktin
.data
);
947 st
->pad
= ssh
->pktin
.data
[4];
950 * _Completely_ silly lengths should be stomped on before they
951 * do us any more damage.
953 if (st
->len
< 0 || st
->pad
< 0 || st
->len
+ st
->pad
< 0) {
954 bombout((ssh
,"Incoming packet was garbled on decryption"));
959 * This enables us to deduce the payload length.
961 st
->payload
= st
->len
- st
->pad
- 1;
963 ssh
->pktin
.length
= st
->payload
+ 5;
966 * So now we can work out the total packet length.
968 st
->packetlen
= st
->len
+ 4;
969 st
->maclen
= ssh
->scmac ? ssh
->scmac
->len
: 0;
972 * Adjust memory allocation if packet is too big.
974 if (ssh
->pktin
.maxlen
< st
->packetlen
+ st
->maclen
) {
975 ssh
->pktin
.maxlen
= st
->packetlen
+ st
->maclen
;
976 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
,
977 ssh
->pktin
.maxlen
+ APIEXTRA
);
981 * Read and decrypt the remainder of the packet.
983 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
;
985 while ((*datalen
) == 0)
986 crReturn(st
->packetlen
+ st
->maclen
- st
->i
);
987 ssh
->pktin
.data
[st
->i
] = *(*data
)++;
990 /* Decrypt everything _except_ the MAC. */
992 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
993 ssh
->pktin
.data
+ st
->cipherblk
,
994 st
->packetlen
- st
->cipherblk
);
1000 && !ssh
->scmac
->verify(ssh
->sc_mac_ctx
, ssh
->pktin
.data
, st
->len
+ 4,
1001 st
->incoming_sequence
)) {
1002 bombout((ssh
,"Incorrect MAC received on packet"));
1005 st
->incoming_sequence
++; /* whether or not we MACed */
1008 * Decompress packet payload.
1011 unsigned char *newpayload
;
1014 ssh
->sccomp
->decompress(ssh
->sc_comp_ctx
,
1015 ssh
->pktin
.data
+ 5, ssh
->pktin
.length
- 5,
1016 &newpayload
, &newlen
)) {
1017 if (ssh
->pktin
.maxlen
< newlen
+ 5) {
1018 ssh
->pktin
.maxlen
= newlen
+ 5;
1019 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
,
1020 ssh
->pktin
.maxlen
+ APIEXTRA
);
1022 ssh
->pktin
.length
= 5 + newlen
;
1023 memcpy(ssh
->pktin
.data
+ 5, newpayload
, newlen
);
1028 ssh
->pktin
.savedpos
= 6;
1029 ssh
->pktin
.type
= ssh
->pktin
.data
[5];
1032 log_packet(ssh
->logctx
, PKT_INCOMING
, ssh
->pktin
.type
,
1033 ssh2_pkt_type(ssh
->pkt_ctx
, ssh
->pktin
.type
),
1034 ssh
->pktin
.data
+6, ssh
->pktin
.length
-6);
1036 switch (ssh
->pktin
.type
) {
1038 * These packets we must handle instantly.
1040 case SSH2_MSG_DISCONNECT
:
1042 /* log reason code in disconnect message */
1045 int reason
= GET_32BIT(ssh
->pktin
.data
+ 6);
1046 unsigned msglen
= GET_32BIT(ssh
->pktin
.data
+ 10);
1048 if (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) {
1049 buf
= dupprintf("Received disconnect message (%s)",
1050 ssh2_disconnect_reasons
[reason
]);
1052 buf
= dupprintf("Received disconnect message (unknown"
1053 " type %d)", reason
);
1057 buf
= dupprintf("Disconnection message text: %n%.*s",
1058 &nowlen
, msglen
, ssh
->pktin
.data
+ 14);
1060 bombout((ssh
,"Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1062 (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) ?
1063 ssh2_disconnect_reasons
[reason
] : "unknown",
1069 case SSH2_MSG_IGNORE
:
1071 case SSH2_MSG_DEBUG
:
1073 /* log the debug message */
1075 /* int display = ssh->pktin.body[6]; */
1076 int stringlen
= GET_32BIT(ssh
->pktin
.data
+7);
1078 strcpy(buf
, "Remote debug message: ");
1079 prefix
= strlen(buf
);
1080 if (stringlen
> (int)(sizeof(buf
)-prefix
-1))
1081 stringlen
= sizeof(buf
)-prefix
-1;
1082 memcpy(buf
+ prefix
, ssh
->pktin
.data
+ 11, stringlen
);
1083 buf
[prefix
+ stringlen
] = '\0';
1086 goto next_packet
; /* FIXME: print the debug message */
1089 * These packets we need do nothing about here.
1091 case SSH2_MSG_UNIMPLEMENTED
:
1092 case SSH2_MSG_SERVICE_REQUEST
:
1093 case SSH2_MSG_SERVICE_ACCEPT
:
1094 case SSH2_MSG_KEXINIT
:
1095 case SSH2_MSG_NEWKEYS
:
1096 case SSH2_MSG_KEXDH_INIT
:
1097 case SSH2_MSG_KEXDH_REPLY
:
1098 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1099 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1100 case SSH2_MSG_KEX_DH_GEX_INIT
:
1101 case SSH2_MSG_KEX_DH_GEX_REPLY
:
1102 case SSH2_MSG_USERAUTH_REQUEST
:
1103 case SSH2_MSG_USERAUTH_FAILURE
:
1104 case SSH2_MSG_USERAUTH_SUCCESS
:
1105 case SSH2_MSG_USERAUTH_BANNER
:
1106 case SSH2_MSG_USERAUTH_PK_OK
:
1107 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1108 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1109 case SSH2_MSG_USERAUTH_INFO_RESPONSE
:
1110 case SSH2_MSG_GLOBAL_REQUEST
:
1111 case SSH2_MSG_REQUEST_SUCCESS
:
1112 case SSH2_MSG_REQUEST_FAILURE
:
1113 case SSH2_MSG_CHANNEL_OPEN
:
1114 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
:
1115 case SSH2_MSG_CHANNEL_OPEN_FAILURE
:
1116 case SSH2_MSG_CHANNEL_WINDOW_ADJUST
:
1117 case SSH2_MSG_CHANNEL_DATA
:
1118 case SSH2_MSG_CHANNEL_EXTENDED_DATA
:
1119 case SSH2_MSG_CHANNEL_EOF
:
1120 case SSH2_MSG_CHANNEL_CLOSE
:
1121 case SSH2_MSG_CHANNEL_REQUEST
:
1122 case SSH2_MSG_CHANNEL_SUCCESS
:
1123 case SSH2_MSG_CHANNEL_FAILURE
:
1127 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1130 ssh2_pkt_init(ssh
, SSH2_MSG_UNIMPLEMENTED
);
1131 ssh2_pkt_adduint32(ssh
, st
->incoming_sequence
- 1);
1139 static void ssh1_pktout_size(Ssh ssh
, int len
)
1143 len
+= 5; /* type and CRC */
1144 pad
= 8 - (len
% 8);
1147 ssh
->pktout
.length
= len
- 5;
1148 if (ssh
->pktout
.maxlen
< biglen
) {
1149 ssh
->pktout
.maxlen
= biglen
;
1151 /* Allocate enough buffer space for extra block
1152 * for MS CryptEncrypt() */
1153 ssh
->pktout
.data
= srealloc(ssh
->pktout
.data
, biglen
+ 12);
1155 ssh
->pktout
.data
= srealloc(ssh
->pktout
.data
, biglen
+ 4);
1158 ssh
->pktout
.body
= ssh
->pktout
.data
+ 4 + pad
+ 1;
1161 static void s_wrpkt_start(Ssh ssh
, int type
, int len
)
1163 ssh1_pktout_size(ssh
, len
);
1164 ssh
->pktout
.type
= type
;
1167 static int s_wrpkt_prepare(Ssh ssh
)
1169 int pad
, len
, biglen
, i
;
1172 ssh
->pktout
.body
[-1] = ssh
->pktout
.type
;
1175 log_packet(ssh
->logctx
, PKT_OUTGOING
, ssh
->pktout
.type
,
1176 ssh1_pkt_type(ssh
->pktout
.type
),
1177 ssh
->pktout
.body
, ssh
->pktout
.length
);
1179 if (ssh
->v1_compressing
) {
1180 unsigned char *compblk
;
1182 zlib_compress_block(ssh
->cs_comp_ctx
,
1183 ssh
->pktout
.body
- 1, ssh
->pktout
.length
+ 1,
1184 &compblk
, &complen
);
1185 ssh1_pktout_size(ssh
, complen
- 1);
1186 memcpy(ssh
->pktout
.body
- 1, compblk
, complen
);
1190 len
= ssh
->pktout
.length
+ 5; /* type and CRC */
1191 pad
= 8 - (len
% 8);
1194 for (i
= 0; i
< pad
; i
++)
1195 ssh
->pktout
.data
[i
+ 4] = random_byte();
1196 crc
= crc32(ssh
->pktout
.data
+ 4, biglen
- 4);
1197 PUT_32BIT(ssh
->pktout
.data
+ biglen
, crc
);
1198 PUT_32BIT(ssh
->pktout
.data
, len
);
1201 ssh
->cipher
->encrypt(ssh
->v1_cipher_ctx
, ssh
->pktout
.data
+ 4, biglen
);
1206 static void s_wrpkt(Ssh ssh
)
1209 len
= s_wrpkt_prepare(ssh
);
1210 backlog
= sk_write(ssh
->s
, (char *)ssh
->pktout
.data
, len
);
1211 if (backlog
> SSH_MAX_BACKLOG
)
1212 ssh_throttle_all(ssh
, 1, backlog
);
1215 static void s_wrpkt_defer(Ssh ssh
)
1218 len
= s_wrpkt_prepare(ssh
);
1219 if (ssh
->deferred_len
+ len
> ssh
->deferred_size
) {
1220 ssh
->deferred_size
= ssh
->deferred_len
+ len
+ 128;
1221 ssh
->deferred_send_data
= srealloc(ssh
->deferred_send_data
,
1222 ssh
->deferred_size
);
1224 memcpy(ssh
->deferred_send_data
+ ssh
->deferred_len
, ssh
->pktout
.data
, len
);
1225 ssh
->deferred_len
+= len
;
1229 * Construct a packet with the specified contents.
1231 static void construct_packet(Ssh ssh
, int pkttype
, va_list ap1
, va_list ap2
)
1233 unsigned char *p
, *argp
, argchar
;
1234 unsigned long argint
;
1235 int pktlen
, argtype
, arglen
;
1239 while ((argtype
= va_arg(ap1
, int)) != PKT_END
) {
1242 (void) va_arg(ap1
, int);
1246 (void) va_arg(ap1
, int);
1250 (void) va_arg(ap1
, unsigned char *);
1251 arglen
= va_arg(ap1
, int);
1255 argp
= va_arg(ap1
, unsigned char *);
1256 arglen
= strlen((char *)argp
);
1257 pktlen
+= 4 + arglen
;
1260 bn
= va_arg(ap1
, Bignum
);
1261 pktlen
+= ssh1_bignum_length(bn
);
1268 s_wrpkt_start(ssh
, pkttype
, pktlen
);
1269 p
= ssh
->pktout
.body
;
1271 while ((argtype
= va_arg(ap2
, int)) != PKT_END
) {
1274 argint
= va_arg(ap2
, int);
1275 PUT_32BIT(p
, argint
);
1279 argchar
= (unsigned char) va_arg(ap2
, int);
1284 argp
= va_arg(ap2
, unsigned char *);
1285 arglen
= va_arg(ap2
, int);
1286 memcpy(p
, argp
, arglen
);
1290 argp
= va_arg(ap2
, unsigned char *);
1291 arglen
= strlen((char *)argp
);
1292 PUT_32BIT(p
, arglen
);
1293 memcpy(p
+ 4, argp
, arglen
);
1297 bn
= va_arg(ap2
, Bignum
);
1298 p
+= ssh1_write_bignum(p
, bn
);
1304 static void send_packet(Ssh ssh
, int pkttype
, ...)
1307 va_start(ap1
, pkttype
);
1308 va_start(ap2
, pkttype
);
1309 construct_packet(ssh
, pkttype
, ap1
, ap2
);
1313 static void defer_packet(Ssh ssh
, int pkttype
, ...)
1316 va_start(ap1
, pkttype
);
1317 va_start(ap2
, pkttype
);
1318 construct_packet(ssh
, pkttype
, ap1
, ap2
);
1322 static int ssh_versioncmp(char *a
, char *b
)
1325 unsigned long av
, bv
;
1327 av
= strtoul(a
, &ae
, 10);
1328 bv
= strtoul(b
, &be
, 10);
1330 return (av
< bv ?
-1 : +1);
1335 av
= strtoul(ae
, &ae
, 10);
1336 bv
= strtoul(be
, &be
, 10);
1338 return (av
< bv ?
-1 : +1);
1343 * Utility routines for putting an SSH-protocol `string' and
1344 * `uint32' into a SHA state.
1347 static void sha_string(SHA_State
* s
, void *str
, int len
)
1349 unsigned char lenblk
[4];
1350 PUT_32BIT(lenblk
, len
);
1351 SHA_Bytes(s
, lenblk
, 4);
1352 SHA_Bytes(s
, str
, len
);
1355 static void sha_uint32(SHA_State
* s
, unsigned i
)
1357 unsigned char intblk
[4];
1358 PUT_32BIT(intblk
, i
);
1359 SHA_Bytes(s
, intblk
, 4);
1363 * SSH2 packet construction functions.
1365 static void ssh2_pkt_ensure(Ssh ssh
, int length
)
1367 if (ssh
->pktout
.maxlen
< length
) {
1368 ssh
->pktout
.maxlen
= length
+ 256;
1369 ssh
->pktout
.data
= srealloc(ssh
->pktout
.data
,
1370 ssh
->pktout
.maxlen
+ APIEXTRA
);
1371 if (!ssh
->pktout
.data
)
1372 fatalbox("Out of memory");
1375 static void ssh2_pkt_adddata(Ssh ssh
, void *data
, int len
)
1377 ssh
->pktout
.length
+= len
;
1378 ssh2_pkt_ensure(ssh
, ssh
->pktout
.length
);
1379 memcpy(ssh
->pktout
.data
+ ssh
->pktout
.length
- len
, data
, len
);
1381 static void ssh2_pkt_addbyte(Ssh ssh
, unsigned char byte
)
1383 ssh2_pkt_adddata(ssh
, &byte
, 1);
1385 static void ssh2_pkt_init(Ssh ssh
, int pkt_type
)
1387 ssh
->pktout
.length
= 5;
1388 ssh2_pkt_addbyte(ssh
, (unsigned char) pkt_type
);
1390 static void ssh2_pkt_addbool(Ssh ssh
, unsigned char value
)
1392 ssh2_pkt_adddata(ssh
, &value
, 1);
1394 static void ssh2_pkt_adduint32(Ssh ssh
, unsigned long value
)
1397 PUT_32BIT(x
, value
);
1398 ssh2_pkt_adddata(ssh
, x
, 4);
1400 static void ssh2_pkt_addstring_start(Ssh ssh
)
1402 ssh2_pkt_adduint32(ssh
, 0);
1403 ssh
->pktout
.savedpos
= ssh
->pktout
.length
;
1405 static void ssh2_pkt_addstring_str(Ssh ssh
, char *data
)
1407 ssh2_pkt_adddata(ssh
, data
, strlen(data
));
1408 PUT_32BIT(ssh
->pktout
.data
+ ssh
->pktout
.savedpos
- 4,
1409 ssh
->pktout
.length
- ssh
->pktout
.savedpos
);
1411 static void ssh2_pkt_addstring_data(Ssh ssh
, char *data
, int len
)
1413 ssh2_pkt_adddata(ssh
, data
, len
);
1414 PUT_32BIT(ssh
->pktout
.data
+ ssh
->pktout
.savedpos
- 4,
1415 ssh
->pktout
.length
- ssh
->pktout
.savedpos
);
1417 static void ssh2_pkt_addstring(Ssh ssh
, char *data
)
1419 ssh2_pkt_addstring_start(ssh
);
1420 ssh2_pkt_addstring_str(ssh
, data
);
1422 static unsigned char *ssh2_mpint_fmt(Bignum b
, int *len
)
1425 int i
, n
= (bignum_bitcount(b
) + 7) / 8;
1428 fatalbox("out of memory");
1430 for (i
= 1; i
<= n
; i
++)
1431 p
[i
] = bignum_byte(b
, n
- i
);
1433 while (i
<= n
&& p
[i
] == 0 && (p
[i
+ 1] & 0x80) == 0)
1435 memmove(p
, p
+ i
, n
+ 1 - i
);
1439 static void ssh2_pkt_addmp(Ssh ssh
, Bignum b
)
1443 p
= ssh2_mpint_fmt(b
, &len
);
1444 ssh2_pkt_addstring_start(ssh
);
1445 ssh2_pkt_addstring_data(ssh
, (char *)p
, len
);
1450 * Construct an SSH2 final-form packet: compress it, encrypt it,
1451 * put the MAC on it. Final packet, ready to be sent, is stored in
1452 * ssh->pktout.data. Total length is returned.
1454 static int ssh2_pkt_construct(Ssh ssh
)
1456 int cipherblk
, maclen
, padding
, i
;
1459 log_packet(ssh
->logctx
, PKT_OUTGOING
, ssh
->pktout
.data
[5],
1460 ssh2_pkt_type(ssh
->pkt_ctx
, ssh
->pktout
.data
[5]),
1461 ssh
->pktout
.data
+ 6, ssh
->pktout
.length
- 6);
1464 * Compress packet payload.
1467 unsigned char *newpayload
;
1470 ssh
->cscomp
->compress(ssh
->cs_comp_ctx
, ssh
->pktout
.data
+ 5,
1471 ssh
->pktout
.length
- 5,
1472 &newpayload
, &newlen
)) {
1473 ssh
->pktout
.length
= 5;
1474 ssh2_pkt_adddata(ssh
, newpayload
, newlen
);
1480 * Add padding. At least four bytes, and must also bring total
1481 * length (minus MAC) up to a multiple of the block size.
1483 cipherblk
= ssh
->cscipher ? ssh
->cscipher
->blksize
: 8; /* block size */
1484 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
1487 (cipherblk
- (ssh
->pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
1488 maclen
= ssh
->csmac ? ssh
->csmac
->len
: 0;
1489 ssh2_pkt_ensure(ssh
, ssh
->pktout
.length
+ padding
+ maclen
);
1490 ssh
->pktout
.data
[4] = padding
;
1491 for (i
= 0; i
< padding
; i
++)
1492 ssh
->pktout
.data
[ssh
->pktout
.length
+ i
] = random_byte();
1493 PUT_32BIT(ssh
->pktout
.data
, ssh
->pktout
.length
+ padding
- 4);
1495 ssh
->csmac
->generate(ssh
->cs_mac_ctx
, ssh
->pktout
.data
,
1496 ssh
->pktout
.length
+ padding
,
1497 ssh
->v2_outgoing_sequence
);
1498 ssh
->v2_outgoing_sequence
++; /* whether or not we MACed */
1501 ssh
->cscipher
->encrypt(ssh
->cs_cipher_ctx
,
1502 ssh
->pktout
.data
, ssh
->pktout
.length
+ padding
);
1504 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1505 return ssh
->pktout
.length
+ padding
+ maclen
;
1509 * Construct and send an SSH2 packet immediately.
1511 static void ssh2_pkt_send(Ssh ssh
)
1515 len
= ssh2_pkt_construct(ssh
);
1516 backlog
= sk_write(ssh
->s
, (char *)ssh
->pktout
.data
, len
);
1517 if (backlog
> SSH_MAX_BACKLOG
)
1518 ssh_throttle_all(ssh
, 1, backlog
);
1522 * Construct an SSH2 packet and add it to a deferred data block.
1523 * Useful for sending multiple packets in a single sk_write() call,
1524 * to prevent a traffic-analysing listener from being able to work
1525 * out the length of any particular packet (such as the password
1528 * Note that because SSH2 sequence-numbers its packets, this can
1529 * NOT be used as an m4-style `defer' allowing packets to be
1530 * constructed in one order and sent in another.
1532 static void ssh2_pkt_defer(Ssh ssh
)
1534 int len
= ssh2_pkt_construct(ssh
);
1535 if (ssh
->deferred_len
+ len
> ssh
->deferred_size
) {
1536 ssh
->deferred_size
= ssh
->deferred_len
+ len
+ 128;
1537 ssh
->deferred_send_data
= srealloc(ssh
->deferred_send_data
,
1538 ssh
->deferred_size
);
1540 memcpy(ssh
->deferred_send_data
+ ssh
->deferred_len
, ssh
->pktout
.data
, len
);
1541 ssh
->deferred_len
+= len
;
1545 * Send the whole deferred data block constructed by
1546 * ssh2_pkt_defer() or SSH1's defer_packet().
1548 static void ssh_pkt_defersend(Ssh ssh
)
1551 backlog
= sk_write(ssh
->s
, (char *)ssh
->deferred_send_data
,
1553 ssh
->deferred_len
= ssh
->deferred_size
= 0;
1554 sfree(ssh
->deferred_send_data
);
1555 ssh
->deferred_send_data
= NULL
;
1556 if (backlog
> SSH_MAX_BACKLOG
)
1557 ssh_throttle_all(ssh
, 1, backlog
);
1561 void bndebug(char *string
, Bignum b
)
1565 p
= ssh2_mpint_fmt(b
, &len
);
1566 debug(("%s", string
));
1567 for (i
= 0; i
< len
; i
++)
1568 debug((" %02x", p
[i
]));
1574 static void sha_mpint(SHA_State
* s
, Bignum b
)
1578 p
= ssh2_mpint_fmt(b
, &len
);
1579 sha_string(s
, p
, len
);
1584 * SSH2 packet decode functions.
1586 static unsigned long ssh2_pkt_getuint32(Ssh ssh
)
1588 unsigned long value
;
1589 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< 4)
1590 return 0; /* arrgh, no way to decline (FIXME?) */
1591 value
= GET_32BIT(ssh
->pktin
.data
+ ssh
->pktin
.savedpos
);
1592 ssh
->pktin
.savedpos
+= 4;
1595 static int ssh2_pkt_getbool(Ssh ssh
)
1597 unsigned long value
;
1598 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< 1)
1599 return 0; /* arrgh, no way to decline (FIXME?) */
1600 value
= ssh
->pktin
.data
[ssh
->pktin
.savedpos
] != 0;
1601 ssh
->pktin
.savedpos
++;
1604 static void ssh2_pkt_getstring(Ssh ssh
, char **p
, int *length
)
1609 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< 4)
1611 len
= GET_32BIT(ssh
->pktin
.data
+ ssh
->pktin
.savedpos
);
1615 ssh
->pktin
.savedpos
+= 4;
1616 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< *length
)
1618 *p
= (char *)(ssh
->pktin
.data
+ ssh
->pktin
.savedpos
);
1619 ssh
->pktin
.savedpos
+= *length
;
1621 static Bignum
ssh2_pkt_getmp(Ssh ssh
)
1627 ssh2_pkt_getstring(ssh
, &p
, &length
);
1631 bombout((ssh
,"internal error: Can't handle negative mpints"));
1634 b
= bignum_from_bytes((unsigned char *)p
, length
);
1639 * Helper function to add an SSH2 signature blob to a packet.
1640 * Expects to be shown the public key blob as well as the signature
1641 * blob. Normally works just like ssh2_pkt_addstring, but will
1642 * fiddle with the signature packet if necessary for
1643 * BUG_SSH2_RSA_PADDING.
1645 static void ssh2_add_sigblob(Ssh ssh
, void *pkblob_v
, int pkblob_len
,
1646 void *sigblob_v
, int sigblob_len
)
1648 unsigned char *pkblob
= (unsigned char *)pkblob_v
;
1649 unsigned char *sigblob
= (unsigned char *)sigblob_v
;
1651 /* dmemdump(pkblob, pkblob_len); */
1652 /* dmemdump(sigblob, sigblob_len); */
1655 * See if this is in fact an ssh-rsa signature and a buggy
1656 * server; otherwise we can just do this the easy way.
1658 if ((ssh
->remote_bugs
& BUG_SSH2_RSA_PADDING
) &&
1659 (GET_32BIT(pkblob
) == 7 && !memcmp(pkblob
+4, "ssh-rsa", 7))) {
1660 int pos
, len
, siglen
;
1663 * Find the byte length of the modulus.
1666 pos
= 4+7; /* skip over "ssh-rsa" */
1667 pos
+= 4 + GET_32BIT(pkblob
+pos
); /* skip over exponent */
1668 len
= GET_32BIT(pkblob
+pos
); /* find length of modulus */
1669 pos
+= 4; /* find modulus itself */
1670 while (len
> 0 && pkblob
[pos
] == 0)
1672 /* debug(("modulus length is %d\n", len)); */
1675 * Now find the signature integer.
1677 pos
= 4+7; /* skip over "ssh-rsa" */
1678 siglen
= GET_32BIT(sigblob
+pos
);
1679 /* debug(("signature length is %d\n", siglen)); */
1681 if (len
!= siglen
) {
1682 unsigned char newlen
[4];
1683 ssh2_pkt_addstring_start(ssh
);
1684 ssh2_pkt_addstring_data(ssh
, (char *)sigblob
, pos
);
1685 /* dmemdump(sigblob, pos); */
1686 pos
+= 4; /* point to start of actual sig */
1687 PUT_32BIT(newlen
, len
);
1688 ssh2_pkt_addstring_data(ssh
, (char *)newlen
, 4);
1689 /* dmemdump(newlen, 4); */
1691 while (len
-- > siglen
) {
1692 ssh2_pkt_addstring_data(ssh
, (char *)newlen
, 1);
1693 /* dmemdump(newlen, 1); */
1695 ssh2_pkt_addstring_data(ssh
, (char *)(sigblob
+pos
), siglen
);
1696 /* dmemdump(sigblob+pos, siglen); */
1700 /* Otherwise fall through and do it the easy way. */
1703 ssh2_pkt_addstring_start(ssh
);
1704 ssh2_pkt_addstring_data(ssh
, (char *)sigblob
, sigblob_len
);
1708 * Examine the remote side's version string and compare it against
1709 * a list of known buggy implementations.
1711 static void ssh_detect_bugs(Ssh ssh
, char *vstring
)
1713 char *imp
; /* pointer to implementation part */
1715 imp
+= strcspn(imp
, "-");
1717 imp
+= strcspn(imp
, "-");
1720 ssh
->remote_bugs
= 0;
1722 if (ssh
->cfg
.sshbug_ignore1
== BUG_ON
||
1723 (ssh
->cfg
.sshbug_ignore1
== BUG_AUTO
&&
1724 (!strcmp(imp
, "1.2.18") || !strcmp(imp
, "1.2.19") ||
1725 !strcmp(imp
, "1.2.20") || !strcmp(imp
, "1.2.21") ||
1726 !strcmp(imp
, "1.2.22") || !strcmp(imp
, "Cisco-1.25")))) {
1728 * These versions don't support SSH1_MSG_IGNORE, so we have
1729 * to use a different defence against password length
1732 ssh
->remote_bugs
|= BUG_CHOKES_ON_SSH1_IGNORE
;
1733 logevent("We believe remote version has SSH1 ignore bug");
1736 if (ssh
->cfg
.sshbug_plainpw1
== BUG_ON
||
1737 (ssh
->cfg
.sshbug_plainpw1
== BUG_AUTO
&&
1738 (!strcmp(imp
, "Cisco-1.25")))) {
1740 * These versions need a plain password sent; they can't
1741 * handle having a null and a random length of data after
1744 ssh
->remote_bugs
|= BUG_NEEDS_SSH1_PLAIN_PASSWORD
;
1745 logevent("We believe remote version needs a plain SSH1 password");
1748 if (ssh
->cfg
.sshbug_rsa1
== BUG_ON
||
1749 (ssh
->cfg
.sshbug_rsa1
== BUG_AUTO
&&
1750 (!strcmp(imp
, "Cisco-1.25")))) {
1752 * These versions apparently have no clue whatever about
1753 * RSA authentication and will panic and die if they see
1754 * an AUTH_RSA message.
1756 ssh
->remote_bugs
|= BUG_CHOKES_ON_RSA
;
1757 logevent("We believe remote version can't handle RSA authentication");
1760 if (ssh
->cfg
.sshbug_hmac2
== BUG_ON
||
1761 (ssh
->cfg
.sshbug_hmac2
== BUG_AUTO
&&
1762 (wc_match("2.1.0*", imp
) || wc_match("2.0.*", imp
) ||
1763 wc_match("2.2.0*", imp
) || wc_match("2.3.0*", imp
) ||
1764 wc_match("2.1 *", imp
)))) {
1766 * These versions have the HMAC bug.
1768 ssh
->remote_bugs
|= BUG_SSH2_HMAC
;
1769 logevent("We believe remote version has SSH2 HMAC bug");
1772 if (ssh
->cfg
.sshbug_derivekey2
== BUG_ON
||
1773 (ssh
->cfg
.sshbug_derivekey2
== BUG_AUTO
&&
1774 (wc_match("2.0.0*", imp
) || wc_match("2.0.1[01]*", imp
) ))) {
1776 * These versions have the key-derivation bug (failing to
1777 * include the literal shared secret in the hashes that
1778 * generate the keys).
1780 ssh
->remote_bugs
|= BUG_SSH2_DERIVEKEY
;
1781 logevent("We believe remote version has SSH2 key-derivation bug");
1784 if (ssh
->cfg
.sshbug_rsapad2
== BUG_ON
||
1785 (ssh
->cfg
.sshbug_rsapad2
== BUG_AUTO
&&
1786 (wc_match("OpenSSH_2.[5-9]*", imp
) ||
1787 wc_match("OpenSSH_3.[0-2]*", imp
)))) {
1789 * These versions have the SSH2 RSA padding bug.
1791 ssh
->remote_bugs
|= BUG_SSH2_RSA_PADDING
;
1792 logevent("We believe remote version has SSH2 RSA padding bug");
1795 if (ssh
->cfg
.sshbug_dhgex2
== BUG_ON
) {
1797 * User specified the SSH2 DH GEX bug.
1799 ssh
->remote_bugs
|= BUG_SSH2_DH_GEX
;
1800 logevent("We believe remote version has SSH2 DH group exchange bug");
1804 static int do_ssh_init(Ssh ssh
, unsigned char c
)
1806 struct do_ssh_init_state
{
1814 crState(do_ssh_init_state
);
1816 crBegin(ssh
->do_ssh_init_crstate
);
1818 /* Search for the string "SSH-" in the input. */
1821 static const int transS
[] = { 1, 2, 2, 1 };
1822 static const int transH
[] = { 0, 0, 3, 0 };
1823 static const int transminus
[] = { 0, 0, 0, -1 };
1825 s
->i
= transS
[s
->i
];
1827 s
->i
= transH
[s
->i
];
1829 s
->i
= transminus
[s
->i
];
1834 crReturn(1); /* get another character */
1838 s
->vstring
= smalloc(s
->vstrsize
);
1839 strcpy(s
->vstring
, "SSH-");
1843 crReturn(1); /* get another char */
1844 if (s
->vslen
>= s
->vstrsize
- 1) {
1846 s
->vstring
= srealloc(s
->vstring
, s
->vstrsize
);
1848 s
->vstring
[s
->vslen
++] = c
;
1851 s
->version
[s
->i
] = '\0';
1853 } else if (s
->i
< sizeof(s
->version
) - 1)
1854 s
->version
[s
->i
++] = c
;
1855 } else if (c
== '\012')
1859 ssh
->agentfwd_enabled
= FALSE
;
1860 ssh
->rdpkt2_state
.incoming_sequence
= 0;
1862 s
->vstring
[s
->vslen
] = 0;
1863 s
->vstring
[strcspn(s
->vstring
, "\r\n")] = '\0';/* remove EOL chars */
1866 vlog
= smalloc(20 + s
->vslen
);
1867 sprintf(vlog
, "Server version: %s", s
->vstring
);
1871 ssh_detect_bugs(ssh
, s
->vstring
);
1874 * Decide which SSH protocol version to support.
1877 /* Anything strictly below "2.0" means protocol 1 is supported. */
1878 s
->proto1
= ssh_versioncmp(s
->version
, "2.0") < 0;
1879 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
1880 s
->proto2
= ssh_versioncmp(s
->version
, "1.99") >= 0;
1882 if (ssh
->cfg
.sshprot
== 0 && !s
->proto1
) {
1883 bombout((ssh
,"SSH protocol version 1 required by user but not provided by server"));
1886 if (ssh
->cfg
.sshprot
== 3 && !s
->proto2
) {
1887 bombout((ssh
,"SSH protocol version 2 required by user but not provided by server"));
1891 if (s
->proto2
&& (ssh
->cfg
.sshprot
>= 2 || !s
->proto1
)) {
1895 char verstring
[80], vlog
[100];
1896 sprintf(verstring
, "SSH-2.0-%s", sshver
);
1897 SHA_Init(&ssh
->exhashbase
);
1899 * Hash our version string and their version string.
1901 sha_string(&ssh
->exhashbase
, verstring
, strlen(verstring
));
1902 sha_string(&ssh
->exhashbase
, s
->vstring
, strcspn(s
->vstring
, "\r\n"));
1903 sprintf(vlog
, "We claim version: %s", verstring
);
1905 strcat(verstring
, "\012");
1906 logevent("Using SSH protocol version 2");
1907 sk_write(ssh
->s
, verstring
, strlen(verstring
));
1908 ssh
->protocol
= ssh2_protocol
;
1910 ssh
->s_rdpkt
= ssh2_rdpkt
;
1915 char verstring
[80], vlog
[100];
1916 sprintf(verstring
, "SSH-%s-%s",
1917 (ssh_versioncmp(s
->version
, "1.5") <= 0 ? s
->version
: "1.5"),
1919 sprintf(vlog
, "We claim version: %s", verstring
);
1921 strcat(verstring
, "\012");
1923 logevent("Using SSH protocol version 1");
1924 sk_write(ssh
->s
, verstring
, strlen(verstring
));
1925 ssh
->protocol
= ssh1_protocol
;
1927 ssh
->s_rdpkt
= ssh1_rdpkt
;
1929 ssh
->state
= SSH_STATE_BEFORE_SIZE
;
1936 static void ssh_gotdata(Ssh ssh
, unsigned char *data
, int datalen
)
1938 crBegin(ssh
->ssh_gotdata_crstate
);
1941 * To begin with, feed the characters one by one to the
1942 * protocol initialisation / selection function do_ssh_init().
1943 * When that returns 0, we're done with the initial greeting
1944 * exchange and can move on to packet discipline.
1947 int ret
; /* need not be kept across crReturn */
1949 crReturnV
; /* more data please */
1950 ret
= do_ssh_init(ssh
, *data
);
1958 * We emerge from that loop when the initial negotiation is
1959 * over and we have selected an s_rdpkt function. Now pass
1960 * everything to s_rdpkt, and then pass the resulting packets
1961 * to the proper protocol handler.
1966 while (datalen
> 0) {
1967 if (ssh
->s_rdpkt(ssh
, &data
, &datalen
) == 0) {
1968 if (ssh
->state
== SSH_STATE_CLOSED
) {
1971 ssh
->protocol(ssh
, NULL
, 0, 1);
1972 if (ssh
->state
== SSH_STATE_CLOSED
) {
1982 static int ssh_closing(Plug plug
, char *error_msg
, int error_code
,
1985 Ssh ssh
= (Ssh
) plug
;
1986 ssh
->state
= SSH_STATE_CLOSED
;
1992 /* A socket error has occurred. */
1993 logevent(error_msg
);
1994 connection_fatal(ssh
->frontend
, error_msg
);
1996 /* Otherwise, the remote side closed the connection normally. */
2001 static int ssh_receive(Plug plug
, int urgent
, char *data
, int len
)
2003 Ssh ssh
= (Ssh
) plug
;
2004 ssh_gotdata(ssh
, (unsigned char *)data
, len
);
2005 if (ssh
->state
== SSH_STATE_CLOSED
) {
2015 static void ssh_sent(Plug plug
, int bufsize
)
2017 Ssh ssh
= (Ssh
) plug
;
2019 * If the send backlog on the SSH socket itself clears, we
2020 * should unthrottle the whole world if it was throttled.
2022 if (bufsize
< SSH_MAX_BACKLOG
)
2023 ssh_throttle_all(ssh
, 0, bufsize
);
2027 * Connect to specified host and port.
2028 * Returns an error message, or NULL on success.
2029 * Also places the canonical host name into `realhost'. It must be
2030 * freed by the caller.
2032 static char *connect_to_host(Ssh ssh
, char *host
, int port
,
2033 char **realhost
, int nodelay
)
2035 static const struct plug_function_table fn_table
= {
2045 ssh
->savedhost
= smalloc(1 + strlen(host
));
2046 if (!ssh
->savedhost
)
2047 fatalbox("Out of memory");
2048 strcpy(ssh
->savedhost
, host
);
2051 port
= 22; /* default ssh port */
2052 ssh
->savedport
= port
;
2057 logeventf(ssh
, "Looking up host \"%s\"", host
);
2058 addr
= name_lookup(host
, port
, realhost
, &ssh
->cfg
);
2059 if ((err
= sk_addr_error(addr
)) != NULL
)
2067 sk_getaddr(addr
, addrbuf
, 100);
2068 logeventf(ssh
, "Connecting to %s port %d", addrbuf
, port
);
2070 ssh
->fn
= &fn_table
;
2071 ssh
->s
= new_connection(addr
, *realhost
, port
,
2072 0, 1, nodelay
, (Plug
) ssh
, &ssh
->cfg
);
2073 if ((err
= sk_socket_error(ssh
->s
)) != NULL
) {
2082 * Throttle or unthrottle the SSH connection.
2084 static void ssh1_throttle(Ssh ssh
, int adjust
)
2086 int old_count
= ssh
->v1_throttle_count
;
2087 ssh
->v1_throttle_count
+= adjust
;
2088 assert(ssh
->v1_throttle_count
>= 0);
2089 if (ssh
->v1_throttle_count
&& !old_count
) {
2090 sk_set_frozen(ssh
->s
, 1);
2091 } else if (!ssh
->v1_throttle_count
&& old_count
) {
2092 sk_set_frozen(ssh
->s
, 0);
2097 * Throttle or unthrottle _all_ local data streams (for when sends
2098 * on the SSH connection itself back up).
2100 static void ssh_throttle_all(Ssh ssh
, int enable
, int bufsize
)
2103 struct ssh_channel
*c
;
2105 if (enable
== ssh
->throttled_all
)
2107 ssh
->throttled_all
= enable
;
2108 ssh
->overall_bufsize
= bufsize
;
2111 for (i
= 0; NULL
!= (c
= index234(ssh
->channels
, i
)); i
++) {
2113 case CHAN_MAINSESSION
:
2115 * This is treated separately, outside the switch.
2119 x11_override_throttle(c
->u
.x11
.s
, enable
);
2122 /* Agent channels require no buffer management. */
2125 pfd_override_throttle(c
->u
.x11
.s
, enable
);
2132 * Username and password input, abstracted off into routines
2133 * reusable in several places - even between SSH1 and SSH2.
2136 /* Set up a username or password input loop on a given buffer. */
2137 static void setup_userpass_input(Ssh ssh
, char *buffer
, int buflen
, int echo
)
2139 ssh
->userpass_input_buffer
= buffer
;
2140 ssh
->userpass_input_buflen
= buflen
;
2141 ssh
->userpass_input_bufpos
= 0;
2142 ssh
->userpass_input_echo
= echo
;
2146 * Process some terminal data in the course of username/password
2147 * input. Returns >0 for success (line of input returned in
2148 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2149 * for inconclusive (keep waiting for more input please).
2151 static int process_userpass_input(Ssh ssh
, unsigned char *in
, int inlen
)
2156 switch (c
= *in
++) {
2159 ssh
->userpass_input_buffer
[ssh
->userpass_input_bufpos
] = 0;
2160 ssh
->userpass_input_buffer
[ssh
->userpass_input_buflen
-1] = 0;
2165 if (ssh
->userpass_input_bufpos
> 0) {
2166 if (ssh
->userpass_input_echo
)
2167 c_write_str(ssh
, "\b \b");
2168 ssh
->userpass_input_bufpos
--;
2173 while (ssh
->userpass_input_bufpos
> 0) {
2174 if (ssh
->userpass_input_echo
)
2175 c_write_str(ssh
, "\b \b");
2176 ssh
->userpass_input_bufpos
--;
2184 if (((c
>= ' ' && c
<= '~') ||
2185 ((unsigned char) c
>= 160))
2186 && ssh
->userpass_input_bufpos
< ssh
->userpass_input_buflen
-1) {
2187 ssh
->userpass_input_buffer
[ssh
->userpass_input_bufpos
++] = c
;
2188 if (ssh
->userpass_input_echo
)
2189 c_write(ssh
, &c
, 1);
2198 * Handle the key exchange and user authentication phases.
2200 static int do_ssh1_login(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
2203 unsigned char cookie
[8];
2204 struct RSAKey servkey
, hostkey
;
2205 struct MD5Context md5c
;
2206 struct do_ssh1_login_state
{
2208 unsigned char *rsabuf
, *keystr1
, *keystr2
;
2209 unsigned long supported_ciphers_mask
, supported_auths_mask
;
2210 int tried_publickey
, tried_agent
;
2211 int tis_auth_refused
, ccard_auth_refused
;
2212 unsigned char session_id
[16];
2215 void *publickey_blob
;
2216 int publickey_bloblen
;
2222 unsigned char request
[5], *response
, *p
;
2231 crState(do_ssh1_login_state
);
2233 crBegin(ssh
->do_ssh1_login_crstate
);
2238 if (ssh
->pktin
.type
!= SSH1_SMSG_PUBLIC_KEY
) {
2239 bombout((ssh
,"Public key packet not received"));
2243 logevent("Received public keys");
2245 memcpy(cookie
, ssh
->pktin
.body
, 8);
2247 i
= makekey(ssh
->pktin
.body
+ 8, &servkey
, &s
->keystr1
, 0);
2248 j
= makekey(ssh
->pktin
.body
+ 8 + i
, &hostkey
, &s
->keystr2
, 0);
2251 * Log the host key fingerprint.
2255 logevent("Host key fingerprint is:");
2256 strcpy(logmsg
, " ");
2257 hostkey
.comment
= NULL
;
2258 rsa_fingerprint(logmsg
+ strlen(logmsg
),
2259 sizeof(logmsg
) - strlen(logmsg
), &hostkey
);
2263 ssh
->v1_remote_protoflags
= GET_32BIT(ssh
->pktin
.body
+ 8 + i
+ j
);
2264 s
->supported_ciphers_mask
= GET_32BIT(ssh
->pktin
.body
+ 12 + i
+ j
);
2265 s
->supported_auths_mask
= GET_32BIT(ssh
->pktin
.body
+ 16 + i
+ j
);
2267 ssh
->v1_local_protoflags
=
2268 ssh
->v1_remote_protoflags
& SSH1_PROTOFLAGS_SUPPORTED
;
2269 ssh
->v1_local_protoflags
|= SSH1_PROTOFLAG_SCREEN_NUMBER
;
2272 MD5Update(&md5c
, s
->keystr2
, hostkey
.bytes
);
2273 MD5Update(&md5c
, s
->keystr1
, servkey
.bytes
);
2274 MD5Update(&md5c
, ssh
->pktin
.body
, 8);
2275 MD5Final(s
->session_id
, &md5c
);
2277 for (i
= 0; i
< 32; i
++)
2278 ssh
->session_key
[i
] = random_byte();
2280 s
->len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
2282 s
->rsabuf
= smalloc(s
->len
);
2284 fatalbox("Out of memory");
2287 * Verify the host key.
2291 * First format the key into a string.
2293 int len
= rsastr_len(&hostkey
);
2294 char fingerprint
[100];
2295 char *keystr
= smalloc(len
);
2297 fatalbox("Out of memory");
2298 rsastr_fmt(keystr
, &hostkey
);
2299 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
2300 verify_ssh_host_key(ssh
->frontend
,
2301 ssh
->savedhost
, ssh
->savedport
, "rsa", keystr
,
2306 for (i
= 0; i
< 32; i
++) {
2307 s
->rsabuf
[i
] = ssh
->session_key
[i
];
2309 s
->rsabuf
[i
] ^= s
->session_id
[i
];
2312 if (hostkey
.bytes
> servkey
.bytes
) {
2313 rsaencrypt(s
->rsabuf
, 32, &servkey
);
2314 rsaencrypt(s
->rsabuf
, servkey
.bytes
, &hostkey
);
2316 rsaencrypt(s
->rsabuf
, 32, &hostkey
);
2317 rsaencrypt(s
->rsabuf
, hostkey
.bytes
, &servkey
);
2320 logevent("Encrypted session key");
2323 int cipher_chosen
= 0, warn
= 0;
2324 char *cipher_string
= NULL
;
2326 for (i
= 0; !cipher_chosen
&& i
< CIPHER_MAX
; i
++) {
2327 int next_cipher
= ssh
->cfg
.ssh_cipherlist
[i
];
2328 if (next_cipher
== CIPHER_WARN
) {
2329 /* If/when we choose a cipher, warn about it */
2331 } else if (next_cipher
== CIPHER_AES
) {
2332 /* XXX Probably don't need to mention this. */
2333 logevent("AES not supported in SSH1, skipping");
2335 switch (next_cipher
) {
2336 case CIPHER_3DES
: s
->cipher_type
= SSH_CIPHER_3DES
;
2337 cipher_string
= "3DES"; break;
2338 case CIPHER_BLOWFISH
: s
->cipher_type
= SSH_CIPHER_BLOWFISH
;
2339 cipher_string
= "Blowfish"; break;
2340 case CIPHER_DES
: s
->cipher_type
= SSH_CIPHER_DES
;
2341 cipher_string
= "single-DES"; break;
2343 if (s
->supported_ciphers_mask
& (1 << s
->cipher_type
))
2347 if (!cipher_chosen
) {
2348 if ((s
->supported_ciphers_mask
& (1 << SSH_CIPHER_3DES
)) == 0)
2349 bombout((ssh
,"Server violates SSH 1 protocol by not "
2350 "supporting 3DES encryption"));
2352 /* shouldn't happen */
2353 bombout((ssh
,"No supported ciphers found"));
2357 /* Warn about chosen cipher if necessary. */
2359 askcipher(ssh
->frontend
, cipher_string
, 0);
2362 switch (s
->cipher_type
) {
2363 case SSH_CIPHER_3DES
:
2364 logevent("Using 3DES encryption");
2366 case SSH_CIPHER_DES
:
2367 logevent("Using single-DES encryption");
2369 case SSH_CIPHER_BLOWFISH
:
2370 logevent("Using Blowfish encryption");
2374 send_packet(ssh
, SSH1_CMSG_SESSION_KEY
,
2375 PKT_CHAR
, s
->cipher_type
,
2376 PKT_DATA
, cookie
, 8,
2377 PKT_CHAR
, (s
->len
* 8) >> 8, PKT_CHAR
, (s
->len
* 8) & 0xFF,
2378 PKT_DATA
, s
->rsabuf
, s
->len
,
2379 PKT_INT
, ssh
->v1_local_protoflags
, PKT_END
);
2381 logevent("Trying to enable encryption...");
2385 ssh
->cipher
= (s
->cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
2386 s
->cipher_type
== SSH_CIPHER_DES ?
&ssh_des
:
2388 ssh
->v1_cipher_ctx
= ssh
->cipher
->make_context();
2389 ssh
->cipher
->sesskey(ssh
->v1_cipher_ctx
, ssh
->session_key
);
2390 logeventf(ssh
, "Initialised %s encryption", ssh
->cipher
->text_name
);
2392 ssh
->crcda_ctx
= crcda_make_context();
2393 logevent("Installing CRC compensation attack detector");
2397 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2398 bombout((ssh
,"Encryption not successfully enabled"));
2402 logevent("Successfully started encryption");
2406 if ((flags
& FLAG_INTERACTIVE
) && !*ssh
->cfg
.username
) {
2407 if (ssh_get_line
&& !ssh_getline_pw_only
) {
2408 if (!ssh_get_line("login as: ",
2409 s
->username
, sizeof(s
->username
), FALSE
)) {
2411 * get_line failed to get a username.
2414 logevent("No username provided. Abandoning session.");
2415 ssh
->state
= SSH_STATE_CLOSED
;
2419 int ret
; /* need not be kept over crReturn */
2420 c_write_str(ssh
, "login as: ");
2423 setup_userpass_input(ssh
, s
->username
, sizeof(s
->username
), 1);
2425 crWaitUntil(!ispkt
);
2426 ret
= process_userpass_input(ssh
, in
, inlen
);
2430 c_write_str(ssh
, "\r\n");
2433 strncpy(s
->username
, ssh
->cfg
.username
, sizeof(s
->username
));
2434 s
->username
[sizeof(s
->username
)-1] = '\0';
2437 send_packet(ssh
, SSH1_CMSG_USER
, PKT_STR
, s
->username
, PKT_END
);
2439 char userlog
[22 + sizeof(s
->username
)];
2440 sprintf(userlog
, "Sent username \"%s\"", s
->username
);
2442 if (flags
& FLAG_INTERACTIVE
&&
2443 (!((flags
& FLAG_STDERR
) && (flags
& FLAG_VERBOSE
)))) {
2444 strcat(userlog
, "\r\n");
2445 c_write_str(ssh
, userlog
);
2452 if ((ssh
->remote_bugs
& BUG_CHOKES_ON_RSA
)) {
2453 /* We must not attempt PK auth. Pretend we've already tried it. */
2454 s
->tried_publickey
= s
->tried_agent
= 1;
2456 s
->tried_publickey
= s
->tried_agent
= 0;
2458 s
->tis_auth_refused
= s
->ccard_auth_refused
= 0;
2459 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
2460 if (*ssh
->cfg
.keyfile
) {
2461 if (!rsakey_pubblob(ssh
->cfg
.keyfile
,
2462 &s
->publickey_blob
, &s
->publickey_bloblen
))
2463 s
->publickey_blob
= NULL
;
2465 s
->publickey_blob
= NULL
;
2467 while (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2468 s
->pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
2470 if (agent_exists() && !s
->tried_agent
) {
2472 * Attempt RSA authentication using Pageant.
2478 logevent("Pageant is running. Requesting keys.");
2480 /* Request the keys held by the agent. */
2481 PUT_32BIT(s
->request
, 1);
2482 s
->request
[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES
;
2483 agent_query(s
->request
, 5, &r
, &s
->responselen
);
2484 s
->response
= (unsigned char *) r
;
2485 if (s
->response
&& s
->responselen
>= 5 &&
2486 s
->response
[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER
) {
2487 s
->p
= s
->response
+ 5;
2488 s
->nkeys
= GET_32BIT(s
->p
);
2492 sprintf(buf
, "Pageant has %d SSH1 keys", s
->nkeys
);
2495 for (s
->keyi
= 0; s
->keyi
< s
->nkeys
; s
->keyi
++) {
2498 sprintf(buf
, "Trying Pageant key #%d", s
->keyi
);
2501 if (s
->publickey_blob
&&
2502 !memcmp(s
->p
, s
->publickey_blob
,
2503 s
->publickey_bloblen
)) {
2504 logevent("This key matches configured key file");
2505 s
->tried_publickey
= 1;
2508 s
->p
+= ssh1_read_bignum(s
->p
, &s
->key
.exponent
);
2509 s
->p
+= ssh1_read_bignum(s
->p
, &s
->key
.modulus
);
2510 s
->commentlen
= GET_32BIT(s
->p
);
2512 s
->commentp
= (char *)s
->p
;
2513 s
->p
+= s
->commentlen
;
2514 send_packet(ssh
, SSH1_CMSG_AUTH_RSA
,
2515 PKT_BIGNUM
, s
->key
.modulus
, PKT_END
);
2517 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2518 logevent("Key refused");
2521 logevent("Received RSA challenge");
2522 ssh1_read_bignum(ssh
->pktin
.body
, &s
->challenge
);
2524 char *agentreq
, *q
, *ret
;
2527 len
= 1 + 4; /* message type, bit count */
2528 len
+= ssh1_bignum_length(s
->key
.exponent
);
2529 len
+= ssh1_bignum_length(s
->key
.modulus
);
2530 len
+= ssh1_bignum_length(s
->challenge
);
2531 len
+= 16; /* session id */
2532 len
+= 4; /* response format */
2533 agentreq
= smalloc(4 + len
);
2534 PUT_32BIT(agentreq
, len
);
2536 *q
++ = SSH1_AGENTC_RSA_CHALLENGE
;
2537 PUT_32BIT(q
, bignum_bitcount(s
->key
.modulus
));
2539 q
+= ssh1_write_bignum(q
, s
->key
.exponent
);
2540 q
+= ssh1_write_bignum(q
, s
->key
.modulus
);
2541 q
+= ssh1_write_bignum(q
, s
->challenge
);
2542 memcpy(q
, s
->session_id
, 16);
2544 PUT_32BIT(q
, 1); /* response format */
2545 agent_query(agentreq
, len
+ 4, &vret
, &retlen
);
2549 if (ret
[4] == SSH1_AGENT_RSA_RESPONSE
) {
2550 logevent("Sending Pageant's response");
2551 send_packet(ssh
, SSH1_CMSG_AUTH_RSA_RESPONSE
,
2552 PKT_DATA
, ret
+ 5, 16,
2556 if (ssh
->pktin
.type
== SSH1_SMSG_SUCCESS
) {
2558 ("Pageant's response accepted");
2559 if (flags
& FLAG_VERBOSE
) {
2560 c_write_str(ssh
, "Authenticated using"
2562 c_write(ssh
, s
->commentp
,
2564 c_write_str(ssh
, "\" from agent\r\n");
2569 ("Pageant's response not accepted");
2572 ("Pageant failed to answer challenge");
2576 logevent("No reply received from Pageant");
2579 freebn(s
->key
.exponent
);
2580 freebn(s
->key
.modulus
);
2581 freebn(s
->challenge
);
2589 if (*ssh
->cfg
.keyfile
&& !s
->tried_publickey
)
2590 s
->pwpkt_type
= SSH1_CMSG_AUTH_RSA
;
2592 if (ssh
->cfg
.try_tis_auth
&&
2593 (s
->supported_auths_mask
& (1 << SSH1_AUTH_TIS
)) &&
2594 !s
->tis_auth_refused
) {
2595 s
->pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
2596 logevent("Requested TIS authentication");
2597 send_packet(ssh
, SSH1_CMSG_AUTH_TIS
, PKT_END
);
2599 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
2600 logevent("TIS authentication declined");
2601 if (flags
& FLAG_INTERACTIVE
)
2602 c_write_str(ssh
, "TIS authentication refused.\r\n");
2603 s
->tis_auth_refused
= 1;
2606 int challengelen
= GET_32BIT(ssh
->pktin
.body
);
2607 logevent("Received TIS challenge");
2608 if (challengelen
> sizeof(s
->prompt
) - 1)
2609 challengelen
= sizeof(s
->prompt
) - 1;/* prevent overrun */
2610 memcpy(s
->prompt
, ssh
->pktin
.body
+ 4, challengelen
);
2611 /* Prompt heuristic comes from OpenSSH */
2612 strncpy(s
->prompt
+ challengelen
,
2613 memchr(s
->prompt
, '\n', challengelen
) ?
2614 "": "\r\nResponse: ",
2615 (sizeof s
->prompt
) - challengelen
);
2616 s
->prompt
[(sizeof s
->prompt
) - 1] = '\0';
2619 if (ssh
->cfg
.try_tis_auth
&&
2620 (s
->supported_auths_mask
& (1 << SSH1_AUTH_CCARD
)) &&
2621 !s
->ccard_auth_refused
) {
2622 s
->pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
2623 logevent("Requested CryptoCard authentication");
2624 send_packet(ssh
, SSH1_CMSG_AUTH_CCARD
, PKT_END
);
2626 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
2627 logevent("CryptoCard authentication declined");
2628 c_write_str(ssh
, "CryptoCard authentication refused.\r\n");
2629 s
->ccard_auth_refused
= 1;
2632 int challengelen
= GET_32BIT(ssh
->pktin
.body
);
2633 logevent("Received CryptoCard challenge");
2634 if (challengelen
> sizeof(s
->prompt
) - 1)
2635 challengelen
= sizeof(s
->prompt
) - 1;/* prevent overrun */
2636 memcpy(s
->prompt
, ssh
->pktin
.body
+ 4, challengelen
);
2637 strncpy(s
->prompt
+ challengelen
,
2638 memchr(s
->prompt
, '\n', challengelen
) ?
2639 "" : "\r\nResponse: ",
2640 sizeof(s
->prompt
) - challengelen
);
2641 s
->prompt
[sizeof(s
->prompt
) - 1] = '\0';
2644 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2645 sprintf(s
->prompt
, "%.90s@%.90s's password: ",
2646 s
->username
, ssh
->savedhost
);
2648 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2649 char *comment
= NULL
;
2652 if (flags
& FLAG_VERBOSE
)
2653 c_write_str(ssh
, "Trying public key authentication.\r\n");
2654 logeventf(ssh
, "Trying public key \"%s\"", ssh
->cfg
.keyfile
);
2655 type
= key_type(ssh
->cfg
.keyfile
);
2656 if (type
!= SSH_KEYTYPE_SSH1
) {
2657 sprintf(msgbuf
, "Key is of wrong type (%s)",
2658 key_type_to_str(type
));
2660 c_write_str(ssh
, msgbuf
);
2661 c_write_str(ssh
, "\r\n");
2662 s
->tried_publickey
= 1;
2665 if (!rsakey_encrypted(ssh
->cfg
.keyfile
, &comment
)) {
2666 if (flags
& FLAG_VERBOSE
)
2667 c_write_str(ssh
, "No passphrase required.\r\n");
2670 sprintf(s
->prompt
, "Passphrase for key \"%.100s\": ", comment
);
2675 * Show password prompt, having first obtained it via a TIS
2676 * or CryptoCard exchange if we're doing TIS or CryptoCard
2680 if (!ssh_get_line(s
->prompt
, s
->password
,
2681 sizeof(s
->password
), TRUE
)) {
2683 * get_line failed to get a password (for example
2684 * because one was supplied on the command line
2685 * which has already failed to work). Terminate.
2687 send_packet(ssh
, SSH1_MSG_DISCONNECT
,
2688 PKT_STR
, "No more passwords available to try",
2690 logevent("Unable to authenticate");
2691 connection_fatal(ssh
->frontend
, "Unable to authenticate");
2692 ssh
->state
= SSH_STATE_CLOSED
;
2696 /* Prompt may have come from server. We've munged it a bit, so
2697 * we know it to be zero-terminated at least once. */
2698 int ret
; /* need not be saved over crReturn */
2699 c_write_untrusted(ssh
, s
->prompt
, strlen(s
->prompt
));
2702 setup_userpass_input(ssh
, s
->password
, sizeof(s
->password
), 0);
2704 crWaitUntil(!ispkt
);
2705 ret
= process_userpass_input(ssh
, in
, inlen
);
2709 c_write_str(ssh
, "\r\n");
2713 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2715 * Try public key authentication with the specified
2718 s
->tried_publickey
= 1;
2721 int ret
= loadrsakey(ssh
->cfg
.keyfile
, &s
->key
, s
->password
);
2723 c_write_str(ssh
, "Couldn't load private key from ");
2724 c_write_str(ssh
, ssh
->cfg
.keyfile
);
2725 c_write_str(ssh
, ".\r\n");
2726 continue; /* go and try password */
2729 c_write_str(ssh
, "Wrong passphrase.\r\n");
2730 s
->tried_publickey
= 0;
2731 continue; /* try again */
2736 * Send a public key attempt.
2738 send_packet(ssh
, SSH1_CMSG_AUTH_RSA
,
2739 PKT_BIGNUM
, s
->key
.modulus
, PKT_END
);
2742 if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2743 c_write_str(ssh
, "Server refused our public key.\r\n");
2744 continue; /* go and try password */
2746 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2747 bombout((ssh
,"Bizarre response to offer of public key"));
2753 unsigned char buffer
[32];
2754 Bignum challenge
, response
;
2756 ssh1_read_bignum(ssh
->pktin
.body
, &challenge
);
2757 response
= rsadecrypt(challenge
, &s
->key
);
2758 freebn(s
->key
.private_exponent
);/* burn the evidence */
2760 for (i
= 0; i
< 32; i
++) {
2761 buffer
[i
] = bignum_byte(response
, 31 - i
);
2765 MD5Update(&md5c
, buffer
, 32);
2766 MD5Update(&md5c
, s
->session_id
, 16);
2767 MD5Final(buffer
, &md5c
);
2769 send_packet(ssh
, SSH1_CMSG_AUTH_RSA_RESPONSE
,
2770 PKT_DATA
, buffer
, 16, PKT_END
);
2777 if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2778 if (flags
& FLAG_VERBOSE
)
2779 c_write_str(ssh
, "Failed to authenticate with"
2780 " our public key.\r\n");
2781 continue; /* go and try password */
2782 } else if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2783 bombout((ssh
,"Bizarre response to RSA authentication response"));
2787 break; /* we're through! */
2789 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2791 * Defence against traffic analysis: we send a
2792 * whole bunch of packets containing strings of
2793 * different lengths. One of these strings is the
2794 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2795 * The others are all random data in
2796 * SSH1_MSG_IGNORE packets. This way a passive
2797 * listener can't tell which is the password, and
2798 * hence can't deduce the password length.
2800 * Anybody with a password length greater than 16
2801 * bytes is going to have enough entropy in their
2802 * password that a listener won't find it _that_
2803 * much help to know how long it is. So what we'll
2806 * - if password length < 16, we send 15 packets
2807 * containing string lengths 1 through 15
2809 * - otherwise, we let N be the nearest multiple
2810 * of 8 below the password length, and send 8
2811 * packets containing string lengths N through
2812 * N+7. This won't obscure the order of
2813 * magnitude of the password length, but it will
2814 * introduce a bit of extra uncertainty.
2816 * A few servers (the old 1.2.18 through 1.2.22)
2817 * can't deal with SSH1_MSG_IGNORE. For these
2818 * servers, we need an alternative defence. We make
2819 * use of the fact that the password is interpreted
2820 * as a C string: so we can append a NUL, then some
2823 * One server (a Cisco one) can deal with neither
2824 * SSH1_MSG_IGNORE _nor_ a padded password string.
2825 * For this server we are left with no defences
2826 * against password length sniffing.
2828 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
)) {
2830 * The server can deal with SSH1_MSG_IGNORE, so
2831 * we can use the primary defence.
2833 int bottom
, top
, pwlen
, i
;
2836 pwlen
= strlen(s
->password
);
2838 bottom
= 0; /* zero length passwords are OK! :-) */
2841 bottom
= pwlen
& ~7;
2845 assert(pwlen
>= bottom
&& pwlen
<= top
);
2847 randomstr
= smalloc(top
+ 1);
2849 for (i
= bottom
; i
<= top
; i
++) {
2851 defer_packet(ssh
, s
->pwpkt_type
,
2852 PKT_STR
, s
->password
, PKT_END
);
2854 for (j
= 0; j
< i
; j
++) {
2856 randomstr
[j
] = random_byte();
2857 } while (randomstr
[j
] == '\0');
2859 randomstr
[i
] = '\0';
2860 defer_packet(ssh
, SSH1_MSG_IGNORE
,
2861 PKT_STR
, randomstr
, PKT_END
);
2864 logevent("Sending password with camouflage packets");
2865 ssh_pkt_defersend(ssh
);
2867 else if (!(ssh
->remote_bugs
& BUG_NEEDS_SSH1_PLAIN_PASSWORD
)) {
2869 * The server can't deal with SSH1_MSG_IGNORE
2870 * but can deal with padded passwords, so we
2871 * can use the secondary defence.
2877 len
= strlen(s
->password
);
2878 if (len
< sizeof(string
)) {
2880 strcpy(string
, s
->password
);
2881 len
++; /* cover the zero byte */
2882 while (len
< sizeof(string
)) {
2883 string
[len
++] = (char) random_byte();
2888 logevent("Sending length-padded password");
2889 send_packet(ssh
, s
->pwpkt_type
, PKT_INT
, len
,
2890 PKT_DATA
, ss
, len
, PKT_END
);
2893 * The server has _both_
2894 * BUG_CHOKES_ON_SSH1_IGNORE and
2895 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2896 * therefore nothing we can do.
2899 len
= strlen(s
->password
);
2900 logevent("Sending unpadded password");
2901 send_packet(ssh
, s
->pwpkt_type
, PKT_INT
, len
,
2902 PKT_DATA
, s
->password
, len
, PKT_END
);
2905 send_packet(ssh
, s
->pwpkt_type
, PKT_STR
, s
->password
, PKT_END
);
2908 logevent("Sent password");
2909 memset(s
->password
, 0, strlen(s
->password
));
2911 if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2912 if (flags
& FLAG_VERBOSE
)
2913 c_write_str(ssh
, "Access denied\r\n");
2914 logevent("Authentication refused");
2915 } else if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2916 bombout((ssh
,"Strange packet received, type %d", ssh
->pktin
.type
));
2921 logevent("Authentication successful");
2926 void sshfwd_close(struct ssh_channel
*c
)
2930 if (c
&& !c
->closes
) {
2932 * If the channel's remoteid is -1, we have sent
2933 * CHANNEL_OPEN for this channel, but it hasn't even been
2934 * acknowledged by the server. So we must set a close flag
2935 * on it now, and then when the server acks the channel
2936 * open, we can close it then.
2938 if (((int)c
->remoteid
) != -1) {
2939 if (ssh
->version
== 1) {
2940 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
2943 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_CLOSE
);
2944 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
2948 c
->closes
= 1; /* sent MSG_CLOSE */
2949 if (c
->type
== CHAN_X11
) {
2951 logevent("Forwarded X11 connection terminated");
2952 } else if (c
->type
== CHAN_SOCKDATA
||
2953 c
->type
== CHAN_SOCKDATA_DORMANT
) {
2955 logevent("Forwarded port closed");
2960 int sshfwd_write(struct ssh_channel
*c
, char *buf
, int len
)
2964 if (ssh
->version
== 1) {
2965 send_packet(ssh
, SSH1_MSG_CHANNEL_DATA
,
2966 PKT_INT
, c
->remoteid
,
2967 PKT_INT
, len
, PKT_DATA
, buf
, len
, PKT_END
);
2969 * In SSH1 we can return 0 here - implying that forwarded
2970 * connections are never individually throttled - because
2971 * the only circumstance that can cause throttling will be
2972 * the whole SSH connection backing up, in which case
2973 * _everything_ will be throttled as a whole.
2977 ssh2_add_channel_data(c
, buf
, len
);
2978 return ssh2_try_send(c
);
2982 void sshfwd_unthrottle(struct ssh_channel
*c
, int bufsize
)
2986 if (ssh
->version
== 1) {
2987 if (c
->v
.v1
.throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
2988 c
->v
.v1
.throttling
= 0;
2989 ssh1_throttle(ssh
, -1);
2992 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
2996 static void ssh1_protocol(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
2998 crBegin(ssh
->ssh1_protocol_crstate
);
3002 while (!do_ssh1_login(ssh
, in
, inlen
, ispkt
)) {
3005 if (ssh
->state
== SSH_STATE_CLOSED
)
3008 if (ssh
->cfg
.agentfwd
&& agent_exists()) {
3009 logevent("Requesting agent forwarding");
3010 send_packet(ssh
, SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
3014 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3015 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3016 bombout((ssh
,"Protocol confusion"));
3018 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3019 logevent("Agent forwarding refused");
3021 logevent("Agent forwarding enabled");
3022 ssh
->agentfwd_enabled
= TRUE
;
3026 if (ssh
->cfg
.x11_forward
) {
3027 char proto
[20], data
[64];
3028 logevent("Requesting X11 forwarding");
3029 ssh
->x11auth
= x11_invent_auth(proto
, sizeof(proto
),
3030 data
, sizeof(data
), ssh
->cfg
.x11_auth
);
3031 x11_get_real_auth(ssh
->x11auth
, ssh
->cfg
.x11_display
);
3032 if (ssh
->v1_local_protoflags
& SSH1_PROTOFLAG_SCREEN_NUMBER
) {
3033 send_packet(ssh
, SSH1_CMSG_X11_REQUEST_FORWARDING
,
3034 PKT_STR
, proto
, PKT_STR
, data
,
3035 PKT_INT
, x11_get_screen_number(ssh
->cfg
.x11_display
),
3038 send_packet(ssh
, SSH1_CMSG_X11_REQUEST_FORWARDING
,
3039 PKT_STR
, proto
, PKT_STR
, data
, PKT_END
);
3044 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3045 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3046 bombout((ssh
,"Protocol confusion"));
3048 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3049 logevent("X11 forwarding refused");
3051 logevent("X11 forwarding enabled");
3052 ssh
->X11_fwd_enabled
= TRUE
;
3059 int sport
,dport
,sserv
,dserv
;
3060 char sports
[256], dports
[256], saddr
[256], host
[256];
3062 ssh
->rportfwds
= newtree234(ssh_rportcmp_ssh1
);
3063 /* Add port forwardings. */
3064 ssh
->portfwd_strptr
= ssh
->cfg
.portfwd
;
3065 while (*ssh
->portfwd_strptr
) {
3066 type
= *ssh
->portfwd_strptr
++;
3069 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= '\t') {
3070 if (*ssh
->portfwd_strptr
== ':') {
3072 * We've seen a colon in the middle of the
3073 * source port number. This means that
3074 * everything we've seen until now is the
3075 * source _address_, so we'll move it into
3076 * saddr and start sports from the beginning
3079 ssh
->portfwd_strptr
++;
3081 strcpy(saddr
, sports
);
3084 if (n
< 255) sports
[n
++] = *ssh
->portfwd_strptr
++;
3087 if (*ssh
->portfwd_strptr
== '\t')
3088 ssh
->portfwd_strptr
++;
3090 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= ':') {
3091 if (n
< 255) host
[n
++] = *ssh
->portfwd_strptr
++;
3094 if (*ssh
->portfwd_strptr
== ':')
3095 ssh
->portfwd_strptr
++;
3097 while (*ssh
->portfwd_strptr
) {
3098 if (n
< 255) dports
[n
++] = *ssh
->portfwd_strptr
++;
3101 ssh
->portfwd_strptr
++;
3102 dport
= atoi(dports
);
3106 dport
= net_service_lookup(dports
);
3108 logeventf(ssh
, "Service lookup failed for"
3109 " destination port \"%s\"", dports
);
3112 sport
= atoi(sports
);
3116 sport
= net_service_lookup(sports
);
3118 logeventf(ssh
, "Service lookup failed for source"
3119 " port \"%s\"", sports
);
3122 if (sport
&& dport
) {
3124 pfd_addforward(host
, dport
, *saddr ? saddr
: NULL
,
3125 sport
, ssh
, &ssh
->cfg
);
3126 logeventf(ssh
, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3127 " forwarding to %s:%.*s%.*s%d%.*s",
3128 (int)(*saddr?
strlen(saddr
):0), *saddr?saddr
:NULL
,
3129 (int)(*saddr?
1:0), ":",
3130 (int)(sserv ?
strlen(sports
) : 0), sports
,
3131 sserv
, "(", sport
, sserv
, ")",
3133 (int)(dserv ?
strlen(dports
) : 0), dports
,
3134 dserv
, "(", dport
, dserv
, ")");
3136 struct ssh_rportfwd
*pf
;
3137 pf
= smalloc(sizeof(*pf
));
3138 strcpy(pf
->dhost
, host
);
3142 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
3145 if (add234(ssh
->rportfwds
, pf
) != pf
) {
3147 "Duplicate remote port forwarding to %s:%d",
3151 logeventf(ssh
, "Requesting remote port %.*s%.*s%d%.*s"
3152 " forward to %s:%.*s%.*s%d%.*s",
3153 (int)(sserv ?
strlen(sports
) : 0), sports
,
3154 sserv
, "(", sport
, sserv
, ")",
3156 (int)(dserv ?
strlen(dports
) : 0), dports
,
3157 dserv
, "(", dport
, dserv
, ")");
3158 send_packet(ssh
, SSH1_CMSG_PORT_FORWARD_REQUEST
,
3166 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3167 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3168 bombout((ssh
,"Protocol confusion"));
3170 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3171 c_write_str(ssh
, "Server refused port"
3174 logevent("Remote port forwarding enabled");
3181 if (!ssh
->cfg
.nopty
) {
3182 send_packet(ssh
, SSH1_CMSG_REQUEST_PTY
,
3183 PKT_STR
, ssh
->cfg
.termtype
,
3184 PKT_INT
, ssh
->term_height
,
3185 PKT_INT
, ssh
->term_width
,
3186 PKT_INT
, 0, PKT_INT
, 0, PKT_CHAR
, 0, PKT_END
);
3187 ssh
->state
= SSH_STATE_INTERMED
;
3191 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3192 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3193 bombout((ssh
,"Protocol confusion"));
3195 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3196 c_write_str(ssh
, "Server refused to allocate pty\r\n");
3197 ssh
->editing
= ssh
->echoing
= 1;
3199 logevent("Allocated pty");
3201 ssh
->editing
= ssh
->echoing
= 1;
3204 if (ssh
->cfg
.compression
) {
3205 send_packet(ssh
, SSH1_CMSG_REQUEST_COMPRESSION
, PKT_INT
, 6, PKT_END
);
3209 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3210 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3211 bombout((ssh
,"Protocol confusion"));
3213 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3214 c_write_str(ssh
, "Server refused to compress\r\n");
3216 logevent("Started compression");
3217 ssh
->v1_compressing
= TRUE
;
3218 ssh
->cs_comp_ctx
= zlib_compress_init();
3219 logevent("Initialised zlib (RFC1950) compression");
3220 ssh
->sc_comp_ctx
= zlib_decompress_init();
3221 logevent("Initialised zlib (RFC1950) decompression");
3225 * Start the shell or command.
3227 * Special case: if the first-choice command is an SSH2
3228 * subsystem (hence not usable here) and the second choice
3229 * exists, we fall straight back to that.
3232 char *cmd
= ssh
->cfg
.remote_cmd_ptr
;
3234 if (ssh
->cfg
.ssh_subsys
&& ssh
->cfg
.remote_cmd_ptr2
) {
3235 cmd
= ssh
->cfg
.remote_cmd_ptr2
;
3236 ssh
->fallback_cmd
= TRUE
;
3239 send_packet(ssh
, SSH1_CMSG_EXEC_CMD
, PKT_STR
, cmd
, PKT_END
);
3241 send_packet(ssh
, SSH1_CMSG_EXEC_SHELL
, PKT_END
);
3242 logevent("Started session");
3245 ssh
->state
= SSH_STATE_SESSION
;
3246 if (ssh
->size_needed
)
3247 ssh_size(ssh
, ssh
->term_width
, ssh
->term_height
);
3248 if (ssh
->eof_needed
)
3249 ssh_special(ssh
, TS_EOF
);
3252 ldisc_send(ssh
->ldisc
, NULL
, 0, 0);/* cause ldisc to notice changes */
3254 ssh
->channels
= newtree234(ssh_channelcmp
);
3258 if (ssh
->pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
3259 ssh
->pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
3260 long len
= GET_32BIT(ssh
->pktin
.body
);
3262 from_backend(ssh
->frontend
,
3263 ssh
->pktin
.type
== SSH1_SMSG_STDERR_DATA
,
3264 (char *)(ssh
->pktin
.body
) + 4, len
);
3265 if (!ssh
->v1_stdout_throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
3266 ssh
->v1_stdout_throttling
= 1;
3267 ssh1_throttle(ssh
, +1);
3269 } else if (ssh
->pktin
.type
== SSH1_MSG_DISCONNECT
) {
3270 ssh
->state
= SSH_STATE_CLOSED
;
3271 logevent("Received disconnect request");
3273 } else if (ssh
->pktin
.type
== SSH1_SMSG_X11_OPEN
) {
3274 /* Remote side is trying to open a channel to talk to our
3275 * X-Server. Give them back a local channel number. */
3276 struct ssh_channel
*c
;
3278 logevent("Received X11 connect request");
3279 /* Refuse if X11 forwarding is disabled. */
3280 if (!ssh
->X11_fwd_enabled
) {
3281 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3282 PKT_INT
, GET_32BIT(ssh
->pktin
.body
), PKT_END
);
3283 logevent("Rejected X11 connect request");
3285 c
= smalloc(sizeof(struct ssh_channel
));
3288 if (x11_init(&c
->u
.x11
.s
, ssh
->cfg
.x11_display
, c
,
3289 ssh
->x11auth
, NULL
, -1, &ssh
->cfg
) != NULL
) {
3290 logevent("opening X11 forward connection failed");
3292 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3293 PKT_INT
, GET_32BIT(ssh
->pktin
.body
),
3297 ("opening X11 forward connection succeeded");
3298 c
->remoteid
= GET_32BIT(ssh
->pktin
.body
);
3299 c
->localid
= alloc_channel_id(ssh
);
3301 c
->v
.v1
.throttling
= 0;
3302 c
->type
= CHAN_X11
; /* identify channel type */
3303 add234(ssh
->channels
, c
);
3304 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3305 PKT_INT
, c
->remoteid
, PKT_INT
,
3306 c
->localid
, PKT_END
);
3307 logevent("Opened X11 forward channel");
3310 } else if (ssh
->pktin
.type
== SSH1_SMSG_AGENT_OPEN
) {
3311 /* Remote side is trying to open a channel to talk to our
3312 * agent. Give them back a local channel number. */
3313 struct ssh_channel
*c
;
3315 /* Refuse if agent forwarding is disabled. */
3316 if (!ssh
->agentfwd_enabled
) {
3317 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3318 PKT_INT
, GET_32BIT(ssh
->pktin
.body
), PKT_END
);
3320 c
= smalloc(sizeof(struct ssh_channel
));
3322 c
->remoteid
= GET_32BIT(ssh
->pktin
.body
);
3323 c
->localid
= alloc_channel_id(ssh
);
3325 c
->v
.v1
.throttling
= 0;
3326 c
->type
= CHAN_AGENT
; /* identify channel type */
3327 c
->u
.a
.lensofar
= 0;
3328 add234(ssh
->channels
, c
);
3329 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3330 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
3333 } else if (ssh
->pktin
.type
== SSH1_MSG_PORT_OPEN
) {
3334 /* Remote side is trying to open a channel to talk to a
3335 * forwarded port. Give them back a local channel number. */
3336 struct ssh_channel
*c
;
3337 struct ssh_rportfwd pf
;
3339 char host
[256], buf
[1024];
3341 c
= smalloc(sizeof(struct ssh_channel
));
3344 hostsize
= GET_32BIT(ssh
->pktin
.body
+4);
3345 for (h
= host
, p
= (char *)(ssh
->pktin
.body
+8);
3346 hostsize
!= 0; hostsize
--) {
3347 if (h
+1 < host
+sizeof(host
))
3352 port
= GET_32BIT(p
);
3354 strcpy(pf
.dhost
, host
);
3357 if (find234(ssh
->rportfwds
, &pf
, NULL
) == NULL
) {
3358 sprintf(buf
, "Rejected remote port open request for %s:%d",
3361 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3362 PKT_INT
, GET_32BIT(ssh
->pktin
.body
), PKT_END
);
3364 sprintf(buf
, "Received remote port open request for %s:%d",
3367 e
= pfd_newconnect(&c
->u
.pfd
.s
, host
, port
, c
, &ssh
->cfg
);
3370 sprintf(buf
, "Port open failed: %s", e
);
3373 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3374 PKT_INT
, GET_32BIT(ssh
->pktin
.body
),
3377 c
->remoteid
= GET_32BIT(ssh
->pktin
.body
);
3378 c
->localid
= alloc_channel_id(ssh
);
3380 c
->v
.v1
.throttling
= 0;
3381 c
->type
= CHAN_SOCKDATA
; /* identify channel type */
3382 add234(ssh
->channels
, c
);
3383 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3384 PKT_INT
, c
->remoteid
, PKT_INT
,
3385 c
->localid
, PKT_END
);
3386 logevent("Forwarded port opened successfully");
3390 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
) {
3391 unsigned int remoteid
= GET_32BIT(ssh
->pktin
.body
);
3392 unsigned int localid
= GET_32BIT(ssh
->pktin
.body
+4);
3393 struct ssh_channel
*c
;
3395 c
= find234(ssh
->channels
, &remoteid
, ssh_channelfind
);
3396 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
3397 c
->remoteid
= localid
;
3398 c
->type
= CHAN_SOCKDATA
;
3399 c
->v
.v1
.throttling
= 0;
3400 pfd_confirm(c
->u
.pfd
.s
);
3403 if (c
&& c
->closes
) {
3405 * We have a pending close on this channel,
3406 * which we decided on before the server acked
3407 * the channel open. So now we know the
3408 * remoteid, we can close it again.
3410 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE
,
3411 PKT_INT
, c
->remoteid
, PKT_END
);
3414 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_OPEN_FAILURE
) {
3415 unsigned int remoteid
= GET_32BIT(ssh
->pktin
.body
);
3416 struct ssh_channel
*c
;
3418 c
= find234(ssh
->channels
, &remoteid
, ssh_channelfind
);
3419 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
3420 logevent("Forwarded connection refused by server");
3421 pfd_close(c
->u
.pfd
.s
);
3422 del234(ssh
->channels
, c
);
3426 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE
||
3427 ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
) {
3428 /* Remote side closes a channel. */
3429 unsigned i
= GET_32BIT(ssh
->pktin
.body
);
3430 struct ssh_channel
*c
;
3431 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
3432 if (c
&& ((int)c
->remoteid
) != -1) {
3435 (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
1 : 2);
3437 if ((c
->closes
== 0) && (c
->type
== CHAN_X11
)) {
3438 logevent("Forwarded X11 connection terminated");
3439 assert(c
->u
.x11
.s
!= NULL
);
3440 x11_close(c
->u
.x11
.s
);
3443 if ((c
->closes
== 0) && (c
->type
== CHAN_SOCKDATA
)) {
3444 logevent("Forwarded port closed");
3445 assert(c
->u
.pfd
.s
!= NULL
);
3446 pfd_close(c
->u
.pfd
.s
);
3450 c
->closes
|= (closetype
<< 2); /* seen this message */
3451 if (!(c
->closes
& closetype
)) {
3452 send_packet(ssh
, ssh
->pktin
.type
, PKT_INT
, c
->remoteid
,
3454 c
->closes
|= closetype
; /* sent it too */
3457 if (c
->closes
== 15) {
3458 del234(ssh
->channels
, c
);
3462 bombout((ssh
,"Received CHANNEL_CLOSE%s for %s channel %d\n",
3463 ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
"" :
3464 "_CONFIRMATION", c ?
"half-open" : "nonexistent",
3467 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_DATA
) {
3468 /* Data sent down one of our channels. */
3469 int i
= GET_32BIT(ssh
->pktin
.body
);
3470 int len
= GET_32BIT(ssh
->pktin
.body
+ 4);
3471 unsigned char *p
= ssh
->pktin
.body
+ 8;
3472 struct ssh_channel
*c
;
3473 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
3478 bufsize
= x11_send(c
->u
.x11
.s
, (char *)p
, len
);
3481 bufsize
= pfd_send(c
->u
.pfd
.s
, (char *)p
, len
);
3484 /* Data for an agent message. Buffer it. */
3486 if (c
->u
.a
.lensofar
< 4) {
3487 int l
= min(4 - c
->u
.a
.lensofar
, len
);
3488 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
,
3492 c
->u
.a
.lensofar
+= l
;
3494 if (c
->u
.a
.lensofar
== 4) {
3496 4 + GET_32BIT(c
->u
.a
.msglen
);
3497 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
3498 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
3500 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
3502 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
3504 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
,
3508 c
->u
.a
.lensofar
+= l
;
3510 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
3511 void *reply
, *sentreply
;
3513 agent_query(c
->u
.a
.message
,
3514 c
->u
.a
.totallen
, &reply
,
3519 /* Fake SSH_AGENT_FAILURE. */
3520 sentreply
= "\0\0\0\1\5";
3523 send_packet(ssh
, SSH1_MSG_CHANNEL_DATA
,
3524 PKT_INT
, c
->remoteid
,
3526 PKT_DATA
, sentreply
, replylen
,
3530 sfree(c
->u
.a
.message
);
3531 c
->u
.a
.lensofar
= 0;
3534 bufsize
= 0; /* agent channels never back up */
3537 if (!c
->v
.v1
.throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
3538 c
->v
.v1
.throttling
= 1;
3539 ssh1_throttle(ssh
, +1);
3542 } else if (ssh
->pktin
.type
== SSH1_SMSG_SUCCESS
) {
3543 /* may be from EXEC_SHELL on some servers */
3544 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3545 /* may be from EXEC_SHELL on some servers
3546 * if no pty is available or in other odd cases. Ignore */
3547 } else if (ssh
->pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
3549 ssh
->exitcode
= GET_32BIT(ssh
->pktin
.body
);
3550 sprintf(buf
, "Server sent command exit status %d",
3553 send_packet(ssh
, SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
3555 * In case `helpful' firewalls or proxies tack
3556 * extra human-readable text on the end of the
3557 * session which we might mistake for another
3558 * encrypted packet, we close the session once
3559 * we've sent EXIT_CONFIRMATION.
3561 ssh
->state
= SSH_STATE_CLOSED
;
3564 bombout((ssh
,"Strange packet received: type %d", ssh
->pktin
.type
));
3569 int len
= min(inlen
, 512);
3570 send_packet(ssh
, SSH1_CMSG_STDIN_DATA
,
3571 PKT_INT
, len
, PKT_DATA
, in
, len
, PKT_END
);
3582 * Utility routine for decoding comma-separated strings in KEXINIT.
3584 static int in_commasep_string(char *needle
, char *haystack
, int haylen
)
3587 if (!needle
|| !haystack
) /* protect against null pointers */
3589 needlen
= strlen(needle
);
3592 * Is it at the start of the string?
3594 if (haylen
>= needlen
&& /* haystack is long enough */
3595 !memcmp(needle
, haystack
, needlen
) && /* initial match */
3596 (haylen
== needlen
|| haystack
[needlen
] == ',')
3597 /* either , or EOS follows */
3601 * If not, search for the next comma and resume after that.
3602 * If no comma found, terminate.
3604 while (haylen
> 0 && *haystack
!= ',')
3605 haylen
--, haystack
++;
3608 haylen
--, haystack
++; /* skip over comma itself */
3613 * SSH2 key creation method.
3615 static void ssh2_mkkey(Ssh ssh
, Bignum K
, unsigned char *H
,
3616 unsigned char *sessid
, char chr
,
3617 unsigned char *keyspace
)
3620 /* First 20 bytes. */
3622 if (!(ssh
->remote_bugs
& BUG_SSH2_DERIVEKEY
))
3624 SHA_Bytes(&s
, H
, 20);
3625 SHA_Bytes(&s
, &chr
, 1);
3626 SHA_Bytes(&s
, sessid
, 20);
3627 SHA_Final(&s
, keyspace
);
3628 /* Next 20 bytes. */
3630 if (!(ssh
->remote_bugs
& BUG_SSH2_DERIVEKEY
))
3632 SHA_Bytes(&s
, H
, 20);
3633 SHA_Bytes(&s
, keyspace
, 20);
3634 SHA_Final(&s
, keyspace
+ 20);
3638 * Handle the SSH2 transport layer.
3640 static int do_ssh2_transport(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
3642 struct do_ssh2_transport_state
{
3643 int nbits
, pbits
, warn
;
3644 Bignum p
, g
, e
, f
, K
;
3645 int kex_init_value
, kex_reply_value
;
3646 const struct ssh_mac
**maclist
;
3648 const struct ssh2_cipher
*cscipher_tobe
;
3649 const struct ssh2_cipher
*sccipher_tobe
;
3650 const struct ssh_mac
*csmac_tobe
;
3651 const struct ssh_mac
*scmac_tobe
;
3652 const struct ssh_compress
*cscomp_tobe
;
3653 const struct ssh_compress
*sccomp_tobe
;
3654 char *hostkeydata
, *sigdata
, *keystr
, *fingerprint
;
3655 int hostkeylen
, siglen
;
3656 void *hkey
; /* actual host key */
3657 unsigned char exchange_hash
[20];
3658 int n_preferred_ciphers
;
3659 const struct ssh2_ciphers
*preferred_ciphers
[CIPHER_MAX
];
3660 const struct ssh_compress
*preferred_comp
;
3663 crState(do_ssh2_transport_state
);
3665 crBegin(ssh
->do_ssh2_transport_crstate
);
3667 s
->cscipher_tobe
= s
->sccipher_tobe
= NULL
;
3668 s
->csmac_tobe
= s
->scmac_tobe
= NULL
;
3669 s
->cscomp_tobe
= s
->sccomp_tobe
= NULL
;
3677 * Set up the preferred ciphers. (NULL => warn below here)
3679 s
->n_preferred_ciphers
= 0;
3680 for (i
= 0; i
< CIPHER_MAX
; i
++) {
3681 switch (ssh
->cfg
.ssh_cipherlist
[i
]) {
3682 case CIPHER_BLOWFISH
:
3683 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_blowfish
;
3686 if (ssh
->cfg
.ssh2_des_cbc
) {
3687 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_des
;
3691 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_3des
;
3694 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_aes
;
3697 /* Flag for later. Don't bother if it's the last in
3699 if (i
< CIPHER_MAX
- 1) {
3700 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = NULL
;
3708 * Set up preferred compression.
3710 if (ssh
->cfg
.compression
)
3711 s
->preferred_comp
= &ssh_zlib
;
3713 s
->preferred_comp
= &ssh_comp_none
;
3716 * Be prepared to work around the buggy MAC problem.
3718 if (ssh
->remote_bugs
& BUG_SSH2_HMAC
)
3719 s
->maclist
= buggymacs
, s
->nmacs
= lenof(buggymacs
);
3721 s
->maclist
= macs
, s
->nmacs
= lenof(macs
);
3725 int i
, j
, cipherstr_started
;
3728 * Construct and send our key exchange packet.
3730 ssh2_pkt_init(ssh
, SSH2_MSG_KEXINIT
);
3731 for (i
= 0; i
< 16; i
++)
3732 ssh2_pkt_addbyte(ssh
, (unsigned char) random_byte());
3733 /* List key exchange algorithms. */
3734 ssh2_pkt_addstring_start(ssh
);
3735 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3736 if (kex_algs
[i
] == &ssh_diffiehellman_gex
&&
3737 (ssh
->remote_bugs
& BUG_SSH2_DH_GEX
))
3739 ssh2_pkt_addstring_str(ssh
, kex_algs
[i
]->name
);
3740 if (i
< lenof(kex_algs
) - 1)
3741 ssh2_pkt_addstring_str(ssh
, ",");
3743 /* List server host key algorithms. */
3744 ssh2_pkt_addstring_start(ssh
);
3745 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3746 ssh2_pkt_addstring_str(ssh
, hostkey_algs
[i
]->name
);
3747 if (i
< lenof(hostkey_algs
) - 1)
3748 ssh2_pkt_addstring_str(ssh
, ",");
3750 /* List client->server encryption algorithms. */
3751 ssh2_pkt_addstring_start(ssh
);
3752 cipherstr_started
= 0;
3753 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
3754 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
3755 if (!c
) continue; /* warning flag */
3756 for (j
= 0; j
< c
->nciphers
; j
++) {
3757 if (cipherstr_started
)
3758 ssh2_pkt_addstring_str(ssh
, ",");
3759 ssh2_pkt_addstring_str(ssh
, c
->list
[j
]->name
);
3760 cipherstr_started
= 1;
3763 /* List server->client encryption algorithms. */
3764 ssh2_pkt_addstring_start(ssh
);
3765 cipherstr_started
= 0;
3766 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
3767 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
3768 if (!c
) continue; /* warning flag */
3769 for (j
= 0; j
< c
->nciphers
; j
++) {
3770 if (cipherstr_started
)
3771 ssh2_pkt_addstring_str(ssh
, ",");
3772 ssh2_pkt_addstring_str(ssh
, c
->list
[j
]->name
);
3773 cipherstr_started
= 1;
3776 /* List client->server MAC algorithms. */
3777 ssh2_pkt_addstring_start(ssh
);
3778 for (i
= 0; i
< s
->nmacs
; i
++) {
3779 ssh2_pkt_addstring_str(ssh
, s
->maclist
[i
]->name
);
3780 if (i
< s
->nmacs
- 1)
3781 ssh2_pkt_addstring_str(ssh
, ",");
3783 /* List server->client MAC algorithms. */
3784 ssh2_pkt_addstring_start(ssh
);
3785 for (i
= 0; i
< s
->nmacs
; i
++) {
3786 ssh2_pkt_addstring_str(ssh
, s
->maclist
[i
]->name
);
3787 if (i
< s
->nmacs
- 1)
3788 ssh2_pkt_addstring_str(ssh
, ",");
3790 /* List client->server 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 server->client compression algorithms. */
3800 ssh2_pkt_addstring_start(ssh
);
3801 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3802 const struct ssh_compress
*c
=
3803 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
3804 ssh2_pkt_addstring_str(ssh
, c
->name
);
3805 if (i
< lenof(compressions
))
3806 ssh2_pkt_addstring_str(ssh
, ",");
3808 /* List client->server languages. Empty list. */
3809 ssh2_pkt_addstring_start(ssh
);
3810 /* List server->client languages. Empty list. */
3811 ssh2_pkt_addstring_start(ssh
);
3812 /* First KEX packet does _not_ follow, because we're not that brave. */
3813 ssh2_pkt_addbool(ssh
, FALSE
);
3815 ssh2_pkt_adduint32(ssh
, 0);
3818 ssh
->exhash
= ssh
->exhashbase
;
3819 sha_string(&ssh
->exhash
, ssh
->pktout
.data
+ 5, ssh
->pktout
.length
- 5);
3825 if (ssh
->pktin
.length
> 5)
3826 sha_string(&ssh
->exhash
, ssh
->pktin
.data
+ 5, ssh
->pktin
.length
- 5);
3829 * Now examine the other side's KEXINIT to see what we're up
3836 if (ssh
->pktin
.type
!= SSH2_MSG_KEXINIT
) {
3837 bombout((ssh
,"expected key exchange packet from server"));
3841 ssh
->hostkey
= NULL
;
3842 s
->cscipher_tobe
= NULL
;
3843 s
->sccipher_tobe
= NULL
;
3844 s
->csmac_tobe
= NULL
;
3845 s
->scmac_tobe
= NULL
;
3846 s
->cscomp_tobe
= NULL
;
3847 s
->sccomp_tobe
= NULL
;
3848 ssh
->pktin
.savedpos
+= 16; /* skip garbage cookie */
3849 ssh2_pkt_getstring(ssh
, &str
, &len
); /* key exchange algorithms */
3850 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3851 if (kex_algs
[i
] == &ssh_diffiehellman_gex
&&
3852 (ssh
->remote_bugs
& BUG_SSH2_DH_GEX
))
3854 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
3855 ssh
->kex
= kex_algs
[i
];
3859 ssh2_pkt_getstring(ssh
, &str
, &len
); /* host key algorithms */
3860 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3861 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
3862 ssh
->hostkey
= hostkey_algs
[i
];
3866 ssh2_pkt_getstring(ssh
, &str
, &len
); /* client->server cipher */
3868 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
3869 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
3873 for (j
= 0; j
< c
->nciphers
; j
++) {
3874 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3875 s
->cscipher_tobe
= c
->list
[j
];
3880 if (s
->cscipher_tobe
) {
3882 askcipher(ssh
->frontend
, s
->cscipher_tobe
->name
, 1);
3886 if (!s
->cscipher_tobe
) {
3887 bombout((ssh
,"Couldn't agree a client-to-server cipher (available: %s)",
3888 str ? str
: "(null)"));
3892 ssh2_pkt_getstring(ssh
, &str
, &len
); /* server->client cipher */
3894 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
3895 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
3899 for (j
= 0; j
< c
->nciphers
; j
++) {
3900 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3901 s
->sccipher_tobe
= c
->list
[j
];
3906 if (s
->sccipher_tobe
) {
3908 askcipher(ssh
->frontend
, s
->sccipher_tobe
->name
, 2);
3912 if (!s
->sccipher_tobe
) {
3913 bombout((ssh
,"Couldn't agree a server-to-client cipher (available: %s)",
3914 str ? str
: "(null)"));
3918 ssh2_pkt_getstring(ssh
, &str
, &len
); /* client->server mac */
3919 for (i
= 0; i
< s
->nmacs
; i
++) {
3920 if (in_commasep_string(s
->maclist
[i
]->name
, str
, len
)) {
3921 s
->csmac_tobe
= s
->maclist
[i
];
3925 ssh2_pkt_getstring(ssh
, &str
, &len
); /* server->client mac */
3926 for (i
= 0; i
< s
->nmacs
; i
++) {
3927 if (in_commasep_string(s
->maclist
[i
]->name
, str
, len
)) {
3928 s
->scmac_tobe
= s
->maclist
[i
];
3932 ssh2_pkt_getstring(ssh
, &str
, &len
); /* client->server 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
)) {
3941 ssh2_pkt_getstring(ssh
, &str
, &len
); /* server->client compression */
3942 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3943 const struct ssh_compress
*c
=
3944 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
3945 if (in_commasep_string(c
->name
, str
, len
)) {
3953 * Work out the number of bits of key we will need from the key
3954 * exchange. We start with the maximum key length of either
3960 csbits
= s
->cscipher_tobe
->keylen
;
3961 scbits
= s
->sccipher_tobe
->keylen
;
3962 s
->nbits
= (csbits
> scbits ? csbits
: scbits
);
3964 /* The keys only have 160-bit entropy, since they're based on
3965 * a SHA-1 hash. So cap the key size at 160 bits. */
3970 * If we're doing Diffie-Hellman group exchange, start by
3971 * requesting a group.
3973 if (ssh
->kex
== &ssh_diffiehellman_gex
) {
3974 logevent("Doing Diffie-Hellman group exchange");
3975 ssh
->pkt_ctx
|= SSH2_PKTCTX_DHGEX
;
3977 * Work out how big a DH group we will need to allow that
3980 s
->pbits
= 512 << ((s
->nbits
- 1) / 64);
3981 ssh2_pkt_init(ssh
, SSH2_MSG_KEX_DH_GEX_REQUEST
);
3982 ssh2_pkt_adduint32(ssh
, s
->pbits
);
3986 if (ssh
->pktin
.type
!= SSH2_MSG_KEX_DH_GEX_GROUP
) {
3987 bombout((ssh
,"expected key exchange group packet from server"));
3990 s
->p
= ssh2_pkt_getmp(ssh
);
3991 s
->g
= ssh2_pkt_getmp(ssh
);
3992 ssh
->kex_ctx
= dh_setup_group(s
->p
, s
->g
);
3993 s
->kex_init_value
= SSH2_MSG_KEX_DH_GEX_INIT
;
3994 s
->kex_reply_value
= SSH2_MSG_KEX_DH_GEX_REPLY
;
3996 ssh
->pkt_ctx
|= SSH2_PKTCTX_DHGROUP1
;
3997 ssh
->kex_ctx
= dh_setup_group1();
3998 s
->kex_init_value
= SSH2_MSG_KEXDH_INIT
;
3999 s
->kex_reply_value
= SSH2_MSG_KEXDH_REPLY
;
4002 logevent("Doing Diffie-Hellman key exchange");
4004 * Now generate and send e for Diffie-Hellman.
4006 s
->e
= dh_create_e(ssh
->kex_ctx
, s
->nbits
* 2);
4007 ssh2_pkt_init(ssh
, s
->kex_init_value
);
4008 ssh2_pkt_addmp(ssh
, s
->e
);
4012 if (ssh
->pktin
.type
!= s
->kex_reply_value
) {
4013 bombout((ssh
,"expected key exchange reply packet from server"));
4016 ssh2_pkt_getstring(ssh
, &s
->hostkeydata
, &s
->hostkeylen
);
4017 s
->f
= ssh2_pkt_getmp(ssh
);
4018 ssh2_pkt_getstring(ssh
, &s
->sigdata
, &s
->siglen
);
4020 s
->K
= dh_find_K(ssh
->kex_ctx
, s
->f
);
4022 sha_string(&ssh
->exhash
, s
->hostkeydata
, s
->hostkeylen
);
4023 if (ssh
->kex
== &ssh_diffiehellman_gex
) {
4024 sha_uint32(&ssh
->exhash
, s
->pbits
);
4025 sha_mpint(&ssh
->exhash
, s
->p
);
4026 sha_mpint(&ssh
->exhash
, s
->g
);
4028 sha_mpint(&ssh
->exhash
, s
->e
);
4029 sha_mpint(&ssh
->exhash
, s
->f
);
4030 sha_mpint(&ssh
->exhash
, s
->K
);
4031 SHA_Final(&ssh
->exhash
, s
->exchange_hash
);
4033 dh_cleanup(ssh
->kex_ctx
);
4034 ssh
->kex_ctx
= NULL
;
4037 debug(("Exchange hash is:\n"));
4038 dmemdump(s
->exchange_hash
, 20);
4041 s
->hkey
= ssh
->hostkey
->newkey(s
->hostkeydata
, s
->hostkeylen
);
4043 !ssh
->hostkey
->verifysig(s
->hkey
, s
->sigdata
, s
->siglen
,
4044 (char *)s
->exchange_hash
, 20)) {
4045 bombout((ssh
,"Server's host key did not match the signature supplied"));
4050 * Authenticate remote host: verify host key. (We've already
4051 * checked the signature of the exchange hash.)
4053 s
->keystr
= ssh
->hostkey
->fmtkey(s
->hkey
);
4054 s
->fingerprint
= ssh
->hostkey
->fingerprint(s
->hkey
);
4055 verify_ssh_host_key(ssh
->frontend
,
4056 ssh
->savedhost
, ssh
->savedport
, ssh
->hostkey
->keytype
,
4057 s
->keystr
, s
->fingerprint
);
4058 if (s
->first_kex
) { /* don't bother logging this in rekeys */
4059 logevent("Host key fingerprint is:");
4060 logevent(s
->fingerprint
);
4062 sfree(s
->fingerprint
);
4064 ssh
->hostkey
->freekey(s
->hkey
);
4067 * Send SSH2_MSG_NEWKEYS.
4069 ssh2_pkt_init(ssh
, SSH2_MSG_NEWKEYS
);
4073 * Expect SSH2_MSG_NEWKEYS from server.
4076 if (ssh
->pktin
.type
!= SSH2_MSG_NEWKEYS
) {
4077 bombout((ssh
,"expected new-keys packet from server"));
4082 * Create and initialise session keys.
4084 if (ssh
->cs_cipher_ctx
)
4085 ssh
->cscipher
->free_context(ssh
->cs_cipher_ctx
);
4086 ssh
->cscipher
= s
->cscipher_tobe
;
4087 ssh
->cs_cipher_ctx
= ssh
->cscipher
->make_context();
4089 if (ssh
->sc_cipher_ctx
)
4090 ssh
->sccipher
->free_context(ssh
->sc_cipher_ctx
);
4091 ssh
->sccipher
= s
->sccipher_tobe
;
4092 ssh
->sc_cipher_ctx
= ssh
->sccipher
->make_context();
4094 if (ssh
->cs_mac_ctx
)
4095 ssh
->csmac
->free_context(ssh
->cs_mac_ctx
);
4096 ssh
->csmac
= s
->csmac_tobe
;
4097 ssh
->cs_mac_ctx
= ssh
->csmac
->make_context();
4099 if (ssh
->sc_mac_ctx
)
4100 ssh
->scmac
->free_context(ssh
->sc_mac_ctx
);
4101 ssh
->scmac
= s
->scmac_tobe
;
4102 ssh
->sc_mac_ctx
= ssh
->scmac
->make_context();
4104 if (ssh
->cs_comp_ctx
)
4105 ssh
->cscomp
->compress_cleanup(ssh
->cs_comp_ctx
);
4106 ssh
->cscomp
= s
->cscomp_tobe
;
4107 ssh
->cs_comp_ctx
= ssh
->cscomp
->compress_init();
4109 if (ssh
->sc_comp_ctx
)
4110 ssh
->sccomp
->decompress_cleanup(ssh
->sc_comp_ctx
);
4111 ssh
->sccomp
= s
->sccomp_tobe
;
4112 ssh
->sc_comp_ctx
= ssh
->sccomp
->decompress_init();
4115 * Set IVs after keys. Here we use the exchange hash from the
4116 * _first_ key exchange.
4119 unsigned char keyspace
[40];
4121 memcpy(ssh
->v2_session_id
, s
->exchange_hash
,
4122 sizeof(s
->exchange_hash
));
4123 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'C',keyspace
);
4124 ssh
->cscipher
->setkey(ssh
->cs_cipher_ctx
, keyspace
);
4125 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'D',keyspace
);
4126 ssh
->sccipher
->setkey(ssh
->sc_cipher_ctx
, keyspace
);
4127 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'A',keyspace
);
4128 ssh
->cscipher
->setiv(ssh
->cs_cipher_ctx
, keyspace
);
4129 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'B',keyspace
);
4130 ssh
->sccipher
->setiv(ssh
->sc_cipher_ctx
, keyspace
);
4131 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'E',keyspace
);
4132 ssh
->csmac
->setkey(ssh
->cs_mac_ctx
, keyspace
);
4133 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'F',keyspace
);
4134 ssh
->scmac
->setkey(ssh
->sc_mac_ctx
, keyspace
);
4136 logeventf(ssh
, "Initialised %.200s client->server encryption",
4137 ssh
->cscipher
->text_name
);
4138 logeventf(ssh
, "Initialised %.200s server->client encryption",
4139 ssh
->sccipher
->text_name
);
4140 if (ssh
->cscomp
->text_name
)
4141 logeventf(ssh
, "Initialised %s compression",
4142 ssh
->cscomp
->text_name
);
4143 if (ssh
->sccomp
->text_name
)
4144 logeventf(ssh
, "Initialised %s decompression",
4145 ssh
->sccomp
->text_name
);
4148 * If this is the first key exchange phase, we must pass the
4149 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4150 * wants to see it but because it will need time to initialise
4151 * itself before it sees an actual packet. In subsequent key
4152 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4153 * it would only confuse the layer above.
4155 if (!s
->first_kex
) {
4161 * Now we're encrypting. Begin returning 1 to the protocol main
4162 * function so that other things can run on top of the
4163 * transport. If we ever see a KEXINIT, we must go back to the
4166 while (!(ispkt
&& ssh
->pktin
.type
== SSH2_MSG_KEXINIT
)) {
4169 logevent("Server initiated key re-exchange");
4170 goto begin_key_exchange
;
4176 * Add data to an SSH2 channel output buffer.
4178 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
4181 bufchain_add(&c
->v
.v2
.outbuffer
, buf
, len
);
4185 * Attempt to send data on an SSH2 channel.
4187 static int ssh2_try_send(struct ssh_channel
*c
)
4191 while (c
->v
.v2
.remwindow
> 0 && bufchain_size(&c
->v
.v2
.outbuffer
) > 0) {
4194 bufchain_prefix(&c
->v
.v2
.outbuffer
, &data
, &len
);
4195 if ((unsigned)len
> c
->v
.v2
.remwindow
)
4196 len
= c
->v
.v2
.remwindow
;
4197 if ((unsigned)len
> c
->v
.v2
.remmaxpkt
)
4198 len
= c
->v
.v2
.remmaxpkt
;
4199 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_DATA
);
4200 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
4201 ssh2_pkt_addstring_start(ssh
);
4202 ssh2_pkt_addstring_data(ssh
, data
, len
);
4204 bufchain_consume(&c
->v
.v2
.outbuffer
, len
);
4205 c
->v
.v2
.remwindow
-= len
;
4209 * After having sent as much data as we can, return the amount
4212 return bufchain_size(&c
->v
.v2
.outbuffer
);
4216 * Potentially enlarge the window on an SSH2 channel.
4218 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
)
4223 * Never send WINDOW_ADJUST for a channel that the remote side
4224 * already thinks it's closed; there's no point, since it won't
4225 * be sending any more data anyway.
4230 if (newwin
> c
->v
.v2
.locwindow
) {
4231 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4232 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
4233 ssh2_pkt_adduint32(ssh
, newwin
- c
->v
.v2
.locwindow
);
4235 c
->v
.v2
.locwindow
= newwin
;
4240 * Handle the SSH2 userauth and connection layers.
4242 static void do_ssh2_authconn(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
4244 struct do_ssh2_authconn_state
{
4246 AUTH_INVALID
, AUTH_PUBLICKEY_AGENT
, AUTH_PUBLICKEY_FILE
,
4248 AUTH_KEYBOARD_INTERACTIVE
4252 AUTH_TYPE_PUBLICKEY
,
4253 AUTH_TYPE_PUBLICKEY_OFFER_LOUD
,
4254 AUTH_TYPE_PUBLICKEY_OFFER_QUIET
,
4256 AUTH_TYPE_KEYBOARD_INTERACTIVE
,
4257 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4259 int gotit
, need_pw
, can_pubkey
, can_passwd
, can_keyb_inter
;
4260 int tried_pubkey_config
, tried_agent
, tried_keyb_inter
;
4261 int kbd_inter_running
;
4263 int num_prompts
, curr_prompt
, echo
;
4268 void *publickey_blob
;
4269 int publickey_bloblen
;
4270 unsigned char request
[5], *response
, *p
;
4274 char *pkblob
, *alg
, *commentp
;
4275 int pklen
, alglen
, commentlen
;
4276 int siglen
, retlen
, len
;
4277 char *q
, *agentreq
, *ret
;
4280 crState(do_ssh2_authconn_state
);
4282 crBegin(ssh
->do_ssh2_authconn_crstate
);
4285 * Request userauth protocol, and await a response to it.
4287 ssh2_pkt_init(ssh
, SSH2_MSG_SERVICE_REQUEST
);
4288 ssh2_pkt_addstring(ssh
, "ssh-userauth");
4290 crWaitUntilV(ispkt
);
4291 if (ssh
->pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
) {
4292 bombout((ssh
,"Server refused user authentication protocol"));
4297 * We repeat this whole loop, including the username prompt,
4298 * until we manage a successful authentication. If the user
4299 * types the wrong _password_, they can be sent back to the
4300 * beginning to try another username, if this is configured on.
4301 * (If they specify a username in the config, they are never
4302 * asked, even if they do give a wrong password.)
4304 * I think this best serves the needs of
4306 * - the people who have no configuration, no keys, and just
4307 * want to try repeated (username,password) pairs until they
4308 * type both correctly
4310 * - people who have keys and configuration but occasionally
4311 * need to fall back to passwords
4313 * - people with a key held in Pageant, who might not have
4314 * logged in to a particular machine before; so they want to
4315 * type a username, and then _either_ their key will be
4316 * accepted, _or_ they will type a password. If they mistype
4317 * the username they will want to be able to get back and
4320 s
->username
[0] = '\0';
4321 s
->got_username
= FALSE
;
4326 if (s
->got_username
&& !ssh
->cfg
.change_username
) {
4328 * We got a username last time round this loop, and
4329 * with change_username turned off we don't try to get
4332 } else if ((flags
& FLAG_INTERACTIVE
) && !*ssh
->cfg
.username
) {
4333 if (ssh_get_line
&& !ssh_getline_pw_only
) {
4334 if (!ssh_get_line("login as: ",
4335 s
->username
, sizeof(s
->username
), FALSE
)) {
4337 * get_line failed to get a username.
4340 logevent("No username provided. Abandoning session.");
4341 ssh
->state
= SSH_STATE_CLOSED
;
4345 int ret
; /* need not be saved across crReturn */
4346 c_write_str(ssh
, "login as: ");
4348 setup_userpass_input(ssh
, s
->username
, sizeof(s
->username
), 1);
4350 crWaitUntilV(!ispkt
);
4351 ret
= process_userpass_input(ssh
, in
, inlen
);
4355 c_write_str(ssh
, "\r\n");
4357 s
->username
[strcspn(s
->username
, "\n\r")] = '\0';
4360 strncpy(s
->username
, ssh
->cfg
.username
, sizeof(s
->username
));
4361 s
->username
[sizeof(s
->username
)-1] = '\0';
4362 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
4363 stuff
= dupprintf("Using username \"%s\".\r\n", s
->username
);
4364 c_write_str(ssh
, stuff
);
4368 s
->got_username
= TRUE
;
4371 * Send an authentication request using method "none": (a)
4372 * just in case it succeeds, and (b) so that we know what
4373 * authentication methods we can usefully try next.
4375 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4377 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4378 ssh2_pkt_addstring(ssh
, s
->username
);
4379 ssh2_pkt_addstring(ssh
, "ssh-connection");/* service requested */
4380 ssh2_pkt_addstring(ssh
, "none"); /* method */
4382 s
->type
= AUTH_TYPE_NONE
;
4384 s
->we_are_in
= FALSE
;
4386 s
->tried_pubkey_config
= FALSE
;
4387 s
->tried_agent
= FALSE
;
4388 s
->tried_keyb_inter
= FALSE
;
4389 s
->kbd_inter_running
= FALSE
;
4390 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
4391 if (*ssh
->cfg
.keyfile
) {
4393 logeventf(ssh
, "Reading private key file \"%.150s\"", ssh
->cfg
.keyfile
);
4394 keytype
= key_type(ssh
->cfg
.keyfile
);
4395 if (keytype
== SSH_KEYTYPE_SSH2
) {
4397 ssh2_userkey_loadpub(ssh
->cfg
.keyfile
, NULL
,
4398 &s
->publickey_bloblen
);
4401 logeventf(ssh
, "Unable to use this key file (%s)",
4402 key_type_to_str(keytype
));
4403 msgbuf
= dupprintf("Unable to use key file \"%.150s\""
4404 " (%s)\r\n", ssh
->cfg
.keyfile
,
4405 key_type_to_str(keytype
));
4406 c_write_str(ssh
, msgbuf
);
4408 s
->publickey_blob
= NULL
;
4411 s
->publickey_blob
= NULL
;
4415 * Wait for the result of the last authentication request.
4418 crWaitUntilV(ispkt
);
4419 while (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_BANNER
) {
4423 * Don't show the banner if we're operating in
4424 * non-verbose non-interactive mode. (It's probably
4425 * a script, which means nobody will read the
4426 * banner _anyway_, and moreover the printing of
4427 * the banner will screw up processing on the
4428 * output of (say) plink.)
4430 if (flags
& (FLAG_VERBOSE
| FLAG_INTERACTIVE
)) {
4431 ssh2_pkt_getstring(ssh
, &banner
, &size
);
4433 c_write_untrusted(ssh
, banner
, size
);
4435 crWaitUntilV(ispkt
);
4437 if (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_SUCCESS
) {
4438 logevent("Access granted");
4439 s
->we_are_in
= TRUE
;
4443 if (s
->kbd_inter_running
&&
4444 ssh
->pktin
.type
== SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4446 * This is either a further set-of-prompts packet
4447 * in keyboard-interactive authentication, or it's
4448 * the same one and we came back here with `gotit'
4449 * set. In the former case, we must reset the
4450 * curr_prompt variable.
4454 } else if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_FAILURE
) {
4455 bombout((ssh
,"Strange packet received during authentication: type %d",
4463 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4464 * we can look at the string in it and know what we can
4465 * helpfully try next.
4467 if (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
) {
4470 ssh2_pkt_getstring(ssh
, &methods
, &methlen
);
4471 s
->kbd_inter_running
= FALSE
;
4472 if (!ssh2_pkt_getbool(ssh
)) {
4474 * We have received an unequivocal Access
4475 * Denied. This can translate to a variety of
4478 * - if we'd just tried "none" authentication,
4479 * it's not worth printing anything at all
4481 * - if we'd just tried a public key _offer_,
4482 * the message should be "Server refused our
4483 * key" (or no message at all if the key
4484 * came from Pageant)
4486 * - if we'd just tried anything else, the
4487 * message really should be "Access denied".
4489 * Additionally, if we'd just tried password
4490 * authentication, we should break out of this
4491 * whole loop so as to go back to the username
4494 if (s
->type
== AUTH_TYPE_NONE
) {
4496 } else if (s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
||
4497 s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_QUIET
) {
4498 if (s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
)
4499 c_write_str(ssh
, "Server refused our key\r\n");
4500 logevent("Server refused public key");
4501 } else if (s
->type
==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
) {
4502 /* server declined keyboard-interactive; ignore */
4504 c_write_str(ssh
, "Access denied\r\n");
4505 logevent("Access denied");
4506 if (s
->type
== AUTH_TYPE_PASSWORD
) {
4507 s
->we_are_in
= FALSE
;
4512 c_write_str(ssh
, "Further authentication required\r\n");
4513 logevent("Further authentication required");
4517 in_commasep_string("publickey", methods
, methlen
);
4519 in_commasep_string("password", methods
, methlen
);
4520 s
->can_keyb_inter
= ssh
->cfg
.try_ki_auth
&&
4521 in_commasep_string("keyboard-interactive", methods
, methlen
);
4525 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4528 * Most password/passphrase prompts will be
4529 * non-echoing, so we set this to 0 by default.
4530 * Exception is that some keyboard-interactive prompts
4531 * can be echoing, in which case we'll set this to 1.
4535 if (!s
->method
&& s
->can_pubkey
&&
4536 agent_exists() && !s
->tried_agent
) {
4538 * Attempt public-key authentication using Pageant.
4543 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4544 ssh
->pkt_ctx
|= SSH2_PKTCTX_PUBLICKEY
;
4546 s
->tried_agent
= TRUE
;
4548 logevent("Pageant is running. Requesting keys.");
4550 /* Request the keys held by the agent. */
4551 PUT_32BIT(s
->request
, 1);
4552 s
->request
[4] = SSH2_AGENTC_REQUEST_IDENTITIES
;
4553 agent_query(s
->request
, 5, &r
, &s
->responselen
);
4554 s
->response
= (unsigned char *) r
;
4555 if (s
->response
&& s
->responselen
>= 5 &&
4556 s
->response
[4] == SSH2_AGENT_IDENTITIES_ANSWER
) {
4557 s
->p
= s
->response
+ 5;
4558 s
->nkeys
= GET_32BIT(s
->p
);
4562 sprintf(buf
, "Pageant has %d SSH2 keys", s
->nkeys
);
4565 for (s
->keyi
= 0; s
->keyi
< s
->nkeys
; s
->keyi
++) {
4570 sprintf(buf
, "Trying Pageant key #%d", s
->keyi
);
4573 s
->pklen
= GET_32BIT(s
->p
);
4575 if (s
->publickey_blob
&&
4576 s
->pklen
== s
->publickey_bloblen
&&
4577 !memcmp(s
->p
, s
->publickey_blob
,
4578 s
->publickey_bloblen
)) {
4579 logevent("This key matches configured key file");
4580 s
->tried_pubkey_config
= 1;
4582 s
->pkblob
= (char *)s
->p
;
4584 s
->alglen
= GET_32BIT(s
->pkblob
);
4585 s
->alg
= s
->pkblob
+ 4;
4586 s
->commentlen
= GET_32BIT(s
->p
);
4588 s
->commentp
= (char *)s
->p
;
4589 s
->p
+= s
->commentlen
;
4590 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4591 ssh2_pkt_addstring(ssh
, s
->username
);
4592 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4593 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4594 ssh2_pkt_addbool(ssh
, FALSE
); /* no signature included */
4595 ssh2_pkt_addstring_start(ssh
);
4596 ssh2_pkt_addstring_data(ssh
, s
->alg
, s
->alglen
);
4597 ssh2_pkt_addstring_start(ssh
);
4598 ssh2_pkt_addstring_data(ssh
, s
->pkblob
, s
->pklen
);
4601 crWaitUntilV(ispkt
);
4602 if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4603 logevent("Key refused");
4607 if (flags
& FLAG_VERBOSE
) {
4608 c_write_str(ssh
, "Authenticating with "
4610 c_write(ssh
, s
->commentp
, s
->commentlen
);
4611 c_write_str(ssh
, "\" from agent\r\n");
4615 * Server is willing to accept the key.
4616 * Construct a SIGN_REQUEST.
4618 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4619 ssh2_pkt_addstring(ssh
, s
->username
);
4620 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4621 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4622 ssh2_pkt_addbool(ssh
, TRUE
);
4623 ssh2_pkt_addstring_start(ssh
);
4624 ssh2_pkt_addstring_data(ssh
, s
->alg
, s
->alglen
);
4625 ssh2_pkt_addstring_start(ssh
);
4626 ssh2_pkt_addstring_data(ssh
, s
->pkblob
, s
->pklen
);
4628 s
->siglen
= ssh
->pktout
.length
- 5 + 4 + 20;
4629 s
->len
= 1; /* message type */
4630 s
->len
+= 4 + s
->pklen
; /* key blob */
4631 s
->len
+= 4 + s
->siglen
; /* data to sign */
4632 s
->len
+= 4; /* flags */
4633 s
->agentreq
= smalloc(4 + s
->len
);
4634 PUT_32BIT(s
->agentreq
, s
->len
);
4635 s
->q
= s
->agentreq
+ 4;
4636 *s
->q
++ = SSH2_AGENTC_SIGN_REQUEST
;
4637 PUT_32BIT(s
->q
, s
->pklen
);
4639 memcpy(s
->q
, s
->pkblob
, s
->pklen
);
4641 PUT_32BIT(s
->q
, s
->siglen
);
4643 /* Now the data to be signed... */
4644 PUT_32BIT(s
->q
, 20);
4646 memcpy(s
->q
, ssh
->v2_session_id
, 20);
4648 memcpy(s
->q
, ssh
->pktout
.data
+ 5,
4649 ssh
->pktout
.length
- 5);
4650 s
->q
+= ssh
->pktout
.length
- 5;
4651 /* And finally the (zero) flags word. */
4653 agent_query(s
->agentreq
, s
->len
+ 4, &vret
, &s
->retlen
);
4657 if (s
->ret
[4] == SSH2_AGENT_SIGN_RESPONSE
) {
4658 logevent("Sending Pageant's response");
4659 ssh2_add_sigblob(ssh
, s
->pkblob
, s
->pklen
,
4661 GET_32BIT(s
->ret
+ 5));
4667 ("Pageant failed to answer challenge");
4677 if (!s
->method
&& s
->can_pubkey
&& s
->publickey_blob
4678 && !s
->tried_pubkey_config
) {
4679 unsigned char *pub_blob
;
4680 char *algorithm
, *comment
;
4683 s
->tried_pubkey_config
= TRUE
;
4685 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4686 ssh
->pkt_ctx
|= SSH2_PKTCTX_PUBLICKEY
;
4689 * Try the public key supplied in the configuration.
4691 * First, offer the public blob to see if the server is
4692 * willing to accept it.
4695 (unsigned char *)ssh2_userkey_loadpub(ssh
->cfg
.keyfile
,
4699 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4700 ssh2_pkt_addstring(ssh
, s
->username
);
4701 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4702 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4703 ssh2_pkt_addbool(ssh
, FALSE
); /* no signature included */
4704 ssh2_pkt_addstring(ssh
, algorithm
);
4705 ssh2_pkt_addstring_start(ssh
);
4706 ssh2_pkt_addstring_data(ssh
, (char *)pub_blob
,
4709 logevent("Offered public key"); /* FIXME */
4711 crWaitUntilV(ispkt
);
4712 if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4714 s
->type
= AUTH_TYPE_PUBLICKEY_OFFER_LOUD
;
4715 continue; /* key refused; give up on it */
4718 logevent("Offer of public key accepted");
4720 * Actually attempt a serious authentication using
4723 if (ssh2_userkey_encrypted(ssh
->cfg
.keyfile
, &comment
)) {
4724 sprintf(s
->pwprompt
,
4725 "Passphrase for key \"%.100s\": ",
4731 c_write_str(ssh
, "Authenticating with public key \"");
4732 c_write_str(ssh
, comment
);
4733 c_write_str(ssh
, "\"\r\n");
4734 s
->method
= AUTH_PUBLICKEY_FILE
;
4738 if (!s
->method
&& s
->can_keyb_inter
&& !s
->tried_keyb_inter
) {
4739 s
->method
= AUTH_KEYBOARD_INTERACTIVE
;
4740 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4741 s
->tried_keyb_inter
= TRUE
;
4743 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4744 ssh
->pkt_ctx
|= SSH2_PKTCTX_KBDINTER
;
4746 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4747 ssh2_pkt_addstring(ssh
, s
->username
);
4748 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4749 ssh2_pkt_addstring(ssh
, "keyboard-interactive"); /* method */
4750 ssh2_pkt_addstring(ssh
, ""); /* lang */
4751 ssh2_pkt_addstring(ssh
, "");
4754 crWaitUntilV(ispkt
);
4755 if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4756 if (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
)
4758 logevent("Keyboard-interactive authentication refused");
4759 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
;
4763 s
->kbd_inter_running
= TRUE
;
4767 if (s
->kbd_inter_running
) {
4768 s
->method
= AUTH_KEYBOARD_INTERACTIVE
;
4769 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4770 s
->tried_keyb_inter
= TRUE
;
4772 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4773 ssh
->pkt_ctx
|= SSH2_PKTCTX_KBDINTER
;
4775 if (s
->curr_prompt
== 0) {
4777 * We've got a fresh USERAUTH_INFO_REQUEST.
4778 * Display header data, and start going through
4781 char *name
, *inst
, *lang
;
4782 int name_len
, inst_len
, lang_len
;
4784 ssh2_pkt_getstring(ssh
, &name
, &name_len
);
4785 ssh2_pkt_getstring(ssh
, &inst
, &inst_len
);
4786 ssh2_pkt_getstring(ssh
, &lang
, &lang_len
);
4788 c_write_untrusted(ssh
, name
, name_len
);
4789 c_write_str(ssh
, "\r\n");
4792 c_write_untrusted(ssh
, inst
, inst_len
);
4793 c_write_str(ssh
, "\r\n");
4795 s
->num_prompts
= ssh2_pkt_getuint32(ssh
);
4799 * If there are prompts remaining in the packet,
4800 * display one and get a response.
4802 if (s
->curr_prompt
< s
->num_prompts
) {
4806 ssh2_pkt_getstring(ssh
, &prompt
, &prompt_len
);
4807 if (prompt_len
> 0) {
4808 strncpy(s
->pwprompt
, prompt
, sizeof(s
->pwprompt
));
4809 s
->pwprompt
[prompt_len
< sizeof(s
->pwprompt
) ?
4810 prompt_len
: sizeof(s
->pwprompt
)-1] = '\0';
4813 "<server failed to send prompt>: ");
4815 s
->echo
= ssh2_pkt_getbool(ssh
);
4821 if (!s
->method
&& s
->can_passwd
) {
4822 s
->method
= AUTH_PASSWORD
;
4823 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4824 ssh
->pkt_ctx
|= SSH2_PKTCTX_PASSWORD
;
4825 sprintf(s
->pwprompt
, "%.90s@%.90s's password: ", s
->username
,
4832 if (!ssh_get_line(s
->pwprompt
, s
->password
,
4833 sizeof(s
->password
), TRUE
)) {
4835 * get_line failed to get a password (for
4836 * example because one was supplied on the
4837 * command line which has already failed to
4840 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
4841 ssh2_pkt_adduint32(ssh
,SSH2_DISCONNECT_BY_APPLICATION
);
4842 ssh2_pkt_addstring(ssh
, "No more passwords available"
4844 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
4846 logevent("Unable to authenticate");
4847 connection_fatal(ssh
->frontend
,
4848 "Unable to authenticate");
4849 ssh
->state
= SSH_STATE_CLOSED
;
4853 int ret
; /* need not be saved across crReturn */
4854 c_write_untrusted(ssh
, s
->pwprompt
, strlen(s
->pwprompt
));
4857 setup_userpass_input(ssh
, s
->password
,
4858 sizeof(s
->password
), s
->echo
);
4860 crWaitUntilV(!ispkt
);
4861 ret
= process_userpass_input(ssh
, in
, inlen
);
4865 c_write_str(ssh
, "\r\n");
4869 if (s
->method
== AUTH_PUBLICKEY_FILE
) {
4871 * We have our passphrase. Now try the actual authentication.
4873 struct ssh2_userkey
*key
;
4875 key
= ssh2_load_userkey(ssh
->cfg
.keyfile
, s
->password
);
4876 if (key
== SSH2_WRONG_PASSPHRASE
|| key
== NULL
) {
4877 if (key
== SSH2_WRONG_PASSPHRASE
) {
4878 c_write_str(ssh
, "Wrong passphrase\r\n");
4879 s
->tried_pubkey_config
= FALSE
;
4881 c_write_str(ssh
, "Unable to load private key\r\n");
4882 s
->tried_pubkey_config
= TRUE
;
4884 /* Send a spurious AUTH_NONE to return to the top. */
4885 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4886 ssh2_pkt_addstring(ssh
, s
->username
);
4887 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4888 ssh2_pkt_addstring(ssh
, "none"); /* method */
4890 s
->type
= AUTH_TYPE_NONE
;
4892 unsigned char *pkblob
, *sigblob
, *sigdata
;
4893 int pkblob_len
, sigblob_len
, sigdata_len
;
4896 * We have loaded the private key and the server
4897 * has announced that it's willing to accept it.
4898 * Hallelujah. Generate a signature and send it.
4900 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4901 ssh2_pkt_addstring(ssh
, s
->username
);
4902 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4903 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4904 ssh2_pkt_addbool(ssh
, TRUE
);
4905 ssh2_pkt_addstring(ssh
, key
->alg
->name
);
4906 pkblob
= key
->alg
->public_blob(key
->data
, &pkblob_len
);
4907 ssh2_pkt_addstring_start(ssh
);
4908 ssh2_pkt_addstring_data(ssh
, (char *)pkblob
, pkblob_len
);
4911 * The data to be signed is:
4915 * followed by everything so far placed in the
4918 sigdata_len
= ssh
->pktout
.length
- 5 + 4 + 20;
4919 sigdata
= smalloc(sigdata_len
);
4920 PUT_32BIT(sigdata
, 20);
4921 memcpy(sigdata
+ 4, ssh
->v2_session_id
, 20);
4922 memcpy(sigdata
+ 24, ssh
->pktout
.data
+ 5,
4923 ssh
->pktout
.length
- 5);
4924 sigblob
= key
->alg
->sign(key
->data
, (char *)sigdata
,
4925 sigdata_len
, &sigblob_len
);
4926 ssh2_add_sigblob(ssh
, pkblob
, pkblob_len
,
4927 sigblob
, sigblob_len
);
4933 s
->type
= AUTH_TYPE_PUBLICKEY
;
4935 } else if (s
->method
== AUTH_PASSWORD
) {
4937 * We send the password packet lumped tightly together with
4938 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4939 * string long enough to make the total length of the two
4940 * packets constant. This should ensure that a passive
4941 * listener doing traffic analyis can't work out the length
4944 * For this to work, we need an assumption about the
4945 * maximum length of the password packet. I think 256 is
4946 * pretty conservative. Anyone using a password longer than
4947 * that probably doesn't have much to worry about from
4948 * people who find out how long their password is!
4950 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4951 ssh2_pkt_addstring(ssh
, s
->username
);
4952 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4953 ssh2_pkt_addstring(ssh
, "password");
4954 ssh2_pkt_addbool(ssh
, FALSE
);
4955 ssh2_pkt_addstring(ssh
, s
->password
);
4956 memset(s
->password
, 0, sizeof(s
->password
));
4957 ssh2_pkt_defer(ssh
);
4959 * We'll include a string that's an exact multiple of the
4960 * cipher block size. If the cipher is NULL for some
4961 * reason, we don't do this trick at all because we gain
4964 if (ssh
->cscipher
) {
4967 stringlen
= (256 - ssh
->deferred_len
);
4968 stringlen
+= ssh
->cscipher
->blksize
- 1;
4969 stringlen
-= (stringlen
% ssh
->cscipher
->blksize
);
4972 * Temporarily disable actual compression,
4973 * so we can guarantee to get this string
4974 * exactly the length we want it. The
4975 * compression-disabling routine should
4976 * return an integer indicating how many
4977 * bytes we should adjust our string length
4981 ssh
->cscomp
->disable_compression(ssh
->cs_comp_ctx
);
4983 ssh2_pkt_init(ssh
, SSH2_MSG_IGNORE
);
4984 ssh2_pkt_addstring_start(ssh
);
4985 for (i
= 0; i
< stringlen
; i
++) {
4986 char c
= (char) random_byte();
4987 ssh2_pkt_addstring_data(ssh
, &c
, 1);
4989 ssh2_pkt_defer(ssh
);
4991 ssh_pkt_defersend(ssh
);
4992 logevent("Sent password");
4993 s
->type
= AUTH_TYPE_PASSWORD
;
4994 } else if (s
->method
== AUTH_KEYBOARD_INTERACTIVE
) {
4995 if (s
->curr_prompt
== 0) {
4996 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_INFO_RESPONSE
);
4997 ssh2_pkt_adduint32(ssh
, s
->num_prompts
);
4999 if (s
->need_pw
) { /* only add pw if we just got one! */
5000 ssh2_pkt_addstring(ssh
, s
->password
);
5001 memset(s
->password
, 0, sizeof(s
->password
));
5004 if (s
->curr_prompt
>= s
->num_prompts
) {
5008 * If there are prompts remaining, we set
5009 * `gotit' so that we won't attempt to get
5010 * another packet. Then we go back round the
5011 * loop and will end up retrieving another
5012 * prompt out of the existing packet. Funky or
5017 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
5019 c_write_str(ssh
, "No supported authentication methods"
5020 " left to try!\r\n");
5021 logevent("No supported authentications offered."
5023 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
5024 ssh2_pkt_adduint32(ssh
, SSH2_DISCONNECT_BY_APPLICATION
);
5025 ssh2_pkt_addstring(ssh
, "No supported authentication"
5026 " methods available");
5027 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5029 ssh
->state
= SSH_STATE_CLOSED
;
5033 } while (!s
->we_are_in
);
5036 * Now we're authenticated for the connection protocol. The
5037 * connection protocol will automatically have started at this
5038 * point; there's no need to send SERVICE_REQUEST.
5042 * So now create a channel with a session in it.
5044 ssh
->channels
= newtree234(ssh_channelcmp
);
5045 ssh
->mainchan
= smalloc(sizeof(struct ssh_channel
));
5046 ssh
->mainchan
->ssh
= ssh
;
5047 ssh
->mainchan
->localid
= alloc_channel_id(ssh
);
5048 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN
);
5049 ssh2_pkt_addstring(ssh
, "session");
5050 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->localid
);
5051 ssh
->mainchan
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5052 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->v
.v2
.locwindow
);/* our window size */
5053 ssh2_pkt_adduint32(ssh
, 0x4000UL
); /* our max pkt size */
5055 crWaitUntilV(ispkt
);
5056 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
5057 bombout((ssh
,"Server refused to open a session"));
5059 /* FIXME: error data comes back in FAILURE packet */
5061 if (ssh2_pkt_getuint32(ssh
) != ssh
->mainchan
->localid
) {
5062 bombout((ssh
,"Server's channel confirmation cited wrong channel"));
5065 ssh
->mainchan
->remoteid
= ssh2_pkt_getuint32(ssh
);
5066 ssh
->mainchan
->type
= CHAN_MAINSESSION
;
5067 ssh
->mainchan
->closes
= 0;
5068 ssh
->mainchan
->v
.v2
.remwindow
= ssh2_pkt_getuint32(ssh
);
5069 ssh
->mainchan
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32(ssh
);
5070 bufchain_init(&ssh
->mainchan
->v
.v2
.outbuffer
);
5071 add234(ssh
->channels
, ssh
->mainchan
);
5072 logevent("Opened channel for session");
5075 * Potentially enable X11 forwarding.
5077 if (ssh
->cfg
.x11_forward
) {
5078 char proto
[20], data
[64];
5079 logevent("Requesting X11 forwarding");
5080 ssh
->x11auth
= x11_invent_auth(proto
, sizeof(proto
),
5081 data
, sizeof(data
), ssh
->cfg
.x11_auth
);
5082 x11_get_real_auth(ssh
->x11auth
, ssh
->cfg
.x11_display
);
5083 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5084 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
5085 ssh2_pkt_addstring(ssh
, "x11-req");
5086 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5087 ssh2_pkt_addbool(ssh
, 0); /* many connections */
5088 ssh2_pkt_addstring(ssh
, proto
);
5089 ssh2_pkt_addstring(ssh
, data
);
5090 ssh2_pkt_adduint32(ssh
, x11_get_screen_number(ssh
->cfg
.x11_display
));
5094 crWaitUntilV(ispkt
);
5095 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5096 unsigned i
= ssh2_pkt_getuint32(ssh
);
5097 struct ssh_channel
*c
;
5098 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5100 continue; /* nonexistent channel */
5101 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5103 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5105 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5106 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5107 bombout((ssh
,"Unexpected response to X11 forwarding request:"
5108 " packet type %d", ssh
->pktin
.type
));
5111 logevent("X11 forwarding refused");
5113 logevent("X11 forwarding enabled");
5114 ssh
->X11_fwd_enabled
= TRUE
;
5119 * Enable port forwardings.
5124 int sport
,dport
,sserv
,dserv
;
5125 char sports
[256], dports
[256], saddr
[256], host
[256];
5127 ssh
->rportfwds
= newtree234(ssh_rportcmp_ssh2
);
5128 /* Add port forwardings. */
5129 ssh
->portfwd_strptr
= ssh
->cfg
.portfwd
;
5130 while (*ssh
->portfwd_strptr
) {
5131 type
= *ssh
->portfwd_strptr
++;
5134 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= '\t') {
5135 if (*ssh
->portfwd_strptr
== ':') {
5137 * We've seen a colon in the middle of the
5138 * source port number. This means that
5139 * everything we've seen until now is the
5140 * source _address_, so we'll move it into
5141 * saddr and start sports from the beginning
5144 ssh
->portfwd_strptr
++;
5146 strcpy(saddr
, sports
);
5149 if (n
< 255) sports
[n
++] = *ssh
->portfwd_strptr
++;
5152 if (*ssh
->portfwd_strptr
== '\t')
5153 ssh
->portfwd_strptr
++;
5155 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= ':') {
5156 if (n
< 255) host
[n
++] = *ssh
->portfwd_strptr
++;
5159 if (*ssh
->portfwd_strptr
== ':')
5160 ssh
->portfwd_strptr
++;
5162 while (*ssh
->portfwd_strptr
) {
5163 if (n
< 255) dports
[n
++] = *ssh
->portfwd_strptr
++;
5166 ssh
->portfwd_strptr
++;
5167 dport
= atoi(dports
);
5171 dport
= net_service_lookup(dports
);
5173 logeventf(ssh
, "Service lookup failed for destination"
5174 " port \"%s\"", dports
);
5177 sport
= atoi(sports
);
5181 sport
= net_service_lookup(sports
);
5183 logeventf(ssh
, "Service lookup failed for source"
5184 " port \"%s\"", sports
);
5187 if (sport
&& dport
) {
5189 pfd_addforward(host
, dport
, *saddr ? saddr
: NULL
,
5190 sport
, ssh
, &ssh
->cfg
);
5191 logeventf(ssh
, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5192 " forwarding to %s:%.*s%.*s%d%.*s",
5193 (int)(*saddr?
strlen(saddr
):0), *saddr?saddr
:NULL
,
5194 (int)(*saddr?
1:0), ":",
5195 (int)(sserv ?
strlen(sports
) : 0), sports
,
5196 sserv
, "(", sport
, sserv
, ")",
5198 (int)(dserv ?
strlen(dports
) : 0), dports
,
5199 dserv
, "(", dport
, dserv
, ")");
5201 struct ssh_rportfwd
*pf
;
5202 pf
= smalloc(sizeof(*pf
));
5203 strcpy(pf
->dhost
, host
);
5206 if (add234(ssh
->rportfwds
, pf
) != pf
) {
5207 logeventf(ssh
, "Duplicate remote port forwarding"
5208 " to %s:%d", host
, dport
);
5211 logeventf(ssh
, "Requesting remote port "
5212 "%.*s%.*s%.*s%.*s%d%.*s"
5213 " forward to %s:%.*s%.*s%d%.*s",
5214 (int)(*saddr?
strlen(saddr
):0),
5216 (int)(*saddr?
1:0), ":",
5217 (int)(sserv ?
strlen(sports
) : 0), sports
,
5218 sserv
, "(", sport
, sserv
, ")",
5220 (int)(dserv ?
strlen(dports
) : 0), dports
,
5221 dserv
, "(", dport
, dserv
, ")");
5222 ssh2_pkt_init(ssh
, SSH2_MSG_GLOBAL_REQUEST
);
5223 ssh2_pkt_addstring(ssh
, "tcpip-forward");
5224 ssh2_pkt_addbool(ssh
, 1);/* want reply */
5226 ssh2_pkt_addstring(ssh
, saddr
);
5227 if (ssh
->cfg
.rport_acceptall
)
5228 ssh2_pkt_addstring(ssh
, "0.0.0.0");
5230 ssh2_pkt_addstring(ssh
, "127.0.0.1");
5231 ssh2_pkt_adduint32(ssh
, sport
);
5235 crWaitUntilV(ispkt
);
5236 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5237 unsigned i
= ssh2_pkt_getuint32(ssh
);
5238 struct ssh_channel
*c
;
5239 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5241 continue;/* nonexistent channel */
5242 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5244 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5246 if (ssh
->pktin
.type
!= SSH2_MSG_REQUEST_SUCCESS
) {
5247 if (ssh
->pktin
.type
!= SSH2_MSG_REQUEST_FAILURE
) {
5248 bombout((ssh
,"Unexpected response to port "
5249 "forwarding request: packet type %d",
5253 logevent("Server refused this port forwarding");
5255 logevent("Remote port forwarding enabled");
5264 * Potentially enable agent forwarding.
5266 if (ssh
->cfg
.agentfwd
&& agent_exists()) {
5267 logevent("Requesting OpenSSH-style agent forwarding");
5268 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5269 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
5270 ssh2_pkt_addstring(ssh
, "auth-agent-req@openssh.com");
5271 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5275 crWaitUntilV(ispkt
);
5276 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5277 unsigned i
= ssh2_pkt_getuint32(ssh
);
5278 struct ssh_channel
*c
;
5279 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5281 continue; /* nonexistent channel */
5282 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5284 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5286 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5287 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5288 bombout((ssh
,"Unexpected response to agent forwarding request:"
5289 " packet type %d", ssh
->pktin
.type
));
5292 logevent("Agent forwarding refused");
5294 logevent("Agent forwarding enabled");
5295 ssh
->agentfwd_enabled
= TRUE
;
5300 * Now allocate a pty for the session.
5302 if (!ssh
->cfg
.nopty
) {
5303 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5304 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
); /* recipient channel */
5305 ssh2_pkt_addstring(ssh
, "pty-req");
5306 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5307 ssh2_pkt_addstring(ssh
, ssh
->cfg
.termtype
);
5308 ssh2_pkt_adduint32(ssh
, ssh
->term_width
);
5309 ssh2_pkt_adduint32(ssh
, ssh
->term_height
);
5310 ssh2_pkt_adduint32(ssh
, 0); /* pixel width */
5311 ssh2_pkt_adduint32(ssh
, 0); /* pixel height */
5312 ssh2_pkt_addstring_start(ssh
);
5313 ssh2_pkt_addstring_data(ssh
, "\0", 1); /* TTY_OP_END, no special options */
5315 ssh
->state
= SSH_STATE_INTERMED
;
5318 crWaitUntilV(ispkt
);
5319 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5320 unsigned i
= ssh2_pkt_getuint32(ssh
);
5321 struct ssh_channel
*c
;
5322 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5324 continue; /* nonexistent channel */
5325 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5327 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5329 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5330 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5331 bombout((ssh
,"Unexpected response to pty request:"
5332 " packet type %d", ssh
->pktin
.type
));
5335 c_write_str(ssh
, "Server refused to allocate pty\r\n");
5336 ssh
->editing
= ssh
->echoing
= 1;
5338 logevent("Allocated pty");
5341 ssh
->editing
= ssh
->echoing
= 1;
5345 * Start a shell or a remote command. We may have to attempt
5346 * this twice if the config data has provided a second choice
5353 if (ssh
->fallback_cmd
) {
5354 subsys
= ssh
->cfg
.ssh_subsys2
;
5355 cmd
= ssh
->cfg
.remote_cmd_ptr2
;
5357 subsys
= ssh
->cfg
.ssh_subsys
;
5358 cmd
= ssh
->cfg
.remote_cmd_ptr
;
5361 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5362 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
); /* recipient channel */
5364 ssh2_pkt_addstring(ssh
, "subsystem");
5365 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5366 ssh2_pkt_addstring(ssh
, cmd
);
5368 ssh2_pkt_addstring(ssh
, "exec");
5369 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5370 ssh2_pkt_addstring(ssh
, cmd
);
5372 ssh2_pkt_addstring(ssh
, "shell");
5373 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5377 crWaitUntilV(ispkt
);
5378 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5379 unsigned i
= ssh2_pkt_getuint32(ssh
);
5380 struct ssh_channel
*c
;
5381 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5383 continue; /* nonexistent channel */
5384 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5386 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5387 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5388 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5389 bombout((ssh
,"Unexpected response to shell/command request:"
5390 " packet type %d", ssh
->pktin
.type
));
5394 * We failed to start the command. If this is the
5395 * fallback command, we really are finished; if it's
5396 * not, and if the fallback command exists, try falling
5397 * back to it before complaining.
5399 if (!ssh
->fallback_cmd
&& ssh
->cfg
.remote_cmd_ptr2
!= NULL
) {
5400 logevent("Primary command failed; attempting fallback");
5401 ssh
->fallback_cmd
= TRUE
;
5404 bombout((ssh
,"Server refused to start a shell/command"));
5407 logevent("Started a shell/command");
5412 ssh
->state
= SSH_STATE_SESSION
;
5413 if (ssh
->size_needed
)
5414 ssh_size(ssh
, ssh
->term_width
, ssh
->term_height
);
5415 if (ssh
->eof_needed
)
5416 ssh_special(ssh
, TS_EOF
);
5422 ldisc_send(ssh
->ldisc
, NULL
, 0, 0);/* cause ldisc to notice changes */
5426 s
->try_send
= FALSE
;
5428 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
5429 ssh
->pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
5432 unsigned i
= ssh2_pkt_getuint32(ssh
);
5433 struct ssh_channel
*c
;
5434 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5436 continue; /* nonexistent channel */
5437 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
5438 ssh2_pkt_getuint32(ssh
) != SSH2_EXTENDED_DATA_STDERR
)
5439 continue; /* extended but not stderr */
5440 ssh2_pkt_getstring(ssh
, &data
, &length
);
5443 c
->v
.v2
.locwindow
-= length
;
5445 case CHAN_MAINSESSION
:
5447 from_backend(ssh
->frontend
, ssh
->pktin
.type
==
5448 SSH2_MSG_CHANNEL_EXTENDED_DATA
,
5452 bufsize
= x11_send(c
->u
.x11
.s
, data
, length
);
5455 bufsize
= pfd_send(c
->u
.pfd
.s
, data
, length
);
5458 while (length
> 0) {
5459 if (c
->u
.a
.lensofar
< 4) {
5460 int l
= min(4 - c
->u
.a
.lensofar
, length
);
5461 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
,
5465 c
->u
.a
.lensofar
+= l
;
5467 if (c
->u
.a
.lensofar
== 4) {
5469 4 + GET_32BIT(c
->u
.a
.msglen
);
5470 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
5471 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
5473 if (c
->u
.a
.lensofar
>= 4 && length
> 0) {
5475 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
5477 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
,
5481 c
->u
.a
.lensofar
+= l
;
5483 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
5484 void *reply
, *sentreply
;
5486 agent_query(c
->u
.a
.message
,
5487 c
->u
.a
.totallen
, &reply
,
5492 /* Fake SSH_AGENT_FAILURE. */
5493 sentreply
= "\0\0\0\1\5";
5496 ssh2_add_channel_data(c
, sentreply
, replylen
);
5500 sfree(c
->u
.a
.message
);
5501 c
->u
.a
.lensofar
= 0;
5508 * If we are not buffering too much data,
5509 * enlarge the window again at the remote side.
5511 if (bufsize
< OUR_V2_WINSIZE
)
5512 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
5514 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_EOF
) {
5515 unsigned i
= ssh2_pkt_getuint32(ssh
);
5516 struct ssh_channel
*c
;
5518 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5520 continue; /* nonexistent channel */
5522 if (c
->type
== CHAN_X11
) {
5524 * Remote EOF on an X11 channel means we should
5525 * wrap up and close the channel ourselves.
5527 x11_close(c
->u
.x11
.s
);
5529 } else if (c
->type
== CHAN_AGENT
) {
5531 } else if (c
->type
== CHAN_SOCKDATA
) {
5532 pfd_close(c
->u
.pfd
.s
);
5535 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_CLOSE
) {
5536 unsigned i
= ssh2_pkt_getuint32(ssh
);
5537 struct ssh_channel
*c
;
5539 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5540 if (!c
|| ((int)c
->remoteid
) == -1) {
5541 bombout((ssh
,"Received CHANNEL_CLOSE for %s channel %d\n",
5542 c ?
"half-open" : "nonexistent", i
));
5544 /* Do pre-close processing on the channel. */
5546 case CHAN_MAINSESSION
:
5547 break; /* nothing to see here, move along */
5549 if (c
->u
.x11
.s
!= NULL
)
5550 x11_close(c
->u
.x11
.s
);
5557 if (c
->u
.pfd
.s
!= NULL
)
5558 pfd_close(c
->u
.pfd
.s
);
5562 if (c
->closes
== 0) {
5563 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_CLOSE
);
5564 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5567 del234(ssh
->channels
, c
);
5568 bufchain_clear(&c
->v
.v2
.outbuffer
);
5572 * See if that was the last channel left open.
5574 if (count234(ssh
->channels
) == 0) {
5577 * We used to send SSH_MSG_DISCONNECT here,
5578 * because I'd believed that _every_ conforming
5579 * SSH2 connection had to end with a disconnect
5580 * being sent by at least one side; apparently
5581 * I was wrong and it's perfectly OK to
5582 * unceremoniously slam the connection shut
5583 * when you're done, and indeed OpenSSH feels
5584 * this is more polite than sending a
5585 * DISCONNECT. So now we don't.
5587 logevent("All channels closed. Disconnecting");
5588 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
5589 ssh2_pkt_adduint32(ssh
, SSH2_DISCONNECT_BY_APPLICATION
);
5590 ssh2_pkt_addstring(ssh
, "All open channels closed");
5591 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5594 ssh
->state
= SSH_STATE_CLOSED
;
5597 continue; /* remote sends close; ignore (FIXME) */
5598 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5599 unsigned i
= ssh2_pkt_getuint32(ssh
);
5600 struct ssh_channel
*c
;
5601 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5602 if (!c
|| c
->closes
)
5603 continue; /* nonexistent or closing channel */
5604 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5606 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
5607 unsigned i
= ssh2_pkt_getuint32(ssh
);
5608 struct ssh_channel
*c
;
5609 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5611 continue; /* nonexistent channel */
5612 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
5613 continue; /* dunno why they're confirming this */
5614 c
->remoteid
= ssh2_pkt_getuint32(ssh
);
5615 c
->type
= CHAN_SOCKDATA
;
5616 c
->v
.v2
.remwindow
= ssh2_pkt_getuint32(ssh
);
5617 c
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32(ssh
);
5619 pfd_confirm(c
->u
.pfd
.s
);
5622 * We have a pending close on this channel,
5623 * which we decided on before the server acked
5624 * the channel open. So now we know the
5625 * remoteid, we can close it again.
5627 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_CLOSE
);
5628 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5631 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_OPEN_FAILURE
) {
5632 unsigned i
= ssh2_pkt_getuint32(ssh
);
5633 struct ssh_channel
*c
;
5634 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5636 continue; /* nonexistent channel */
5637 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
5638 continue; /* dunno why they're failing this */
5640 logevent("Forwarded connection refused by server");
5642 pfd_close(c
->u
.pfd
.s
);
5644 del234(ssh
->channels
, c
);
5646 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_REQUEST
) {
5649 int typelen
, want_reply
;
5650 struct ssh_channel
*c
;
5652 localid
= ssh2_pkt_getuint32(ssh
);
5653 ssh2_pkt_getstring(ssh
, &type
, &typelen
);
5654 want_reply
= ssh2_pkt_getbool(ssh
);
5657 * First, check that the channel exists. Otherwise,
5658 * we can instantly disconnect with a rude message.
5660 c
= find234(ssh
->channels
, &localid
, ssh_channelfind
);
5663 sprintf(buf
, "Received channel request for nonexistent"
5664 " channel %d", localid
);
5666 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
5667 ssh2_pkt_adduint32(ssh
, SSH2_DISCONNECT_BY_APPLICATION
);
5668 ssh2_pkt_addstring(ssh
, buf
);
5669 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5671 connection_fatal("%s", buf
);
5672 ssh
->state
= SSH_STATE_CLOSED
;
5677 * Having got the channel number, we now look at
5678 * the request type string to see if it's something
5681 if (typelen
== 11 && !memcmp(type
, "exit-status", 11) &&
5682 c
== ssh
->mainchan
) {
5683 /* We recognise "exit-status" on the primary channel. */
5685 ssh
->exitcode
= ssh2_pkt_getuint32(ssh
);
5686 sprintf(buf
, "Server sent command exit status %d",
5690 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_SUCCESS
);
5691 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5696 * This is a channel request we don't know
5697 * about, so we now either ignore the request
5698 * or respond with CHANNEL_FAILURE, depending
5702 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_FAILURE
);
5703 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5707 } else if (ssh
->pktin
.type
== SSH2_MSG_GLOBAL_REQUEST
) {
5709 int typelen
, want_reply
;
5711 ssh2_pkt_getstring(ssh
, &type
, &typelen
);
5712 want_reply
= ssh2_pkt_getbool(ssh
);
5715 * We currently don't support any global requests
5716 * at all, so we either ignore the request or
5717 * respond with REQUEST_FAILURE, depending on
5721 ssh2_pkt_init(ssh
, SSH2_MSG_REQUEST_FAILURE
);
5724 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_OPEN
) {
5731 struct ssh_channel
*c
;
5732 unsigned remid
, winsize
, pktsize
;
5733 ssh2_pkt_getstring(ssh
, &type
, &typelen
);
5734 c
= smalloc(sizeof(struct ssh_channel
));
5737 remid
= ssh2_pkt_getuint32(ssh
);
5738 winsize
= ssh2_pkt_getuint32(ssh
);
5739 pktsize
= ssh2_pkt_getuint32(ssh
);
5740 ssh2_pkt_getstring(ssh
, &peeraddr
, &peeraddrlen
);
5741 port
= ssh2_pkt_getuint32(ssh
);
5743 if (typelen
== 3 && !memcmp(type
, "x11", 3)) {
5744 char *addrstr
= smalloc(peeraddrlen
+1);
5745 memcpy(addrstr
, peeraddr
, peeraddrlen
);
5746 peeraddr
[peeraddrlen
] = '\0';
5748 if (!ssh
->X11_fwd_enabled
)
5749 error
= "X11 forwarding is not enabled";
5750 else if (x11_init(&c
->u
.x11
.s
, ssh
->cfg
.x11_display
, c
,
5751 ssh
->x11auth
, addrstr
, port
,
5752 &ssh
->cfg
) != NULL
) {
5753 error
= "Unable to open an X11 connection";
5759 } else if (typelen
== 15 &&
5760 !memcmp(type
, "forwarded-tcpip", 15)) {
5761 struct ssh_rportfwd pf
, *realpf
;
5764 ssh2_pkt_getstring(ssh
, &dummy
, &dummylen
);/* skip address */
5765 pf
.sport
= ssh2_pkt_getuint32(ssh
);
5766 realpf
= find234(ssh
->rportfwds
, &pf
, NULL
);
5767 if (realpf
== NULL
) {
5768 error
= "Remote port is not recognised";
5770 char *e
= pfd_newconnect(&c
->u
.pfd
.s
, realpf
->dhost
,
5771 realpf
->dport
, c
, &ssh
->cfg
);
5772 logeventf(ssh
, "Received remote port open request"
5773 " for %s:%d", realpf
->dhost
, realpf
->dport
);
5775 logeventf(ssh
, "Port open failed: %s", e
);
5776 error
= "Port open failed";
5778 logevent("Forwarded port opened successfully");
5779 c
->type
= CHAN_SOCKDATA
;
5782 } else if (typelen
== 22 &&
5783 !memcmp(type
, "auth-agent@openssh.com", 3)) {
5784 if (!ssh
->agentfwd_enabled
)
5785 error
= "Agent forwarding is not enabled";
5787 c
->type
= CHAN_AGENT
; /* identify channel type */
5788 c
->u
.a
.lensofar
= 0;
5791 error
= "Unsupported channel type requested";
5794 c
->remoteid
= remid
;
5796 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN_FAILURE
);
5797 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5798 ssh2_pkt_adduint32(ssh
, SSH2_OPEN_CONNECT_FAILED
);
5799 ssh2_pkt_addstring(ssh
, error
);
5800 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5804 c
->localid
= alloc_channel_id(ssh
);
5806 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5807 c
->v
.v2
.remwindow
= winsize
;
5808 c
->v
.v2
.remmaxpkt
= pktsize
;
5809 bufchain_init(&c
->v
.v2
.outbuffer
);
5810 add234(ssh
->channels
, c
);
5811 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
5812 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5813 ssh2_pkt_adduint32(ssh
, c
->localid
);
5814 ssh2_pkt_adduint32(ssh
, c
->v
.v2
.locwindow
);
5815 ssh2_pkt_adduint32(ssh
, 0x4000UL
); /* our max pkt size */
5819 bombout((ssh
,"Strange packet received: type %d", ssh
->pktin
.type
));
5824 * We have spare data. Add it to the channel buffer.
5826 ssh2_add_channel_data(ssh
->mainchan
, (char *)in
, inlen
);
5831 struct ssh_channel
*c
;
5833 * Try to send data on all channels if we can.
5835 for (i
= 0; NULL
!= (c
= index234(ssh
->channels
, i
)); i
++) {
5838 continue; /* don't send on closing channels */
5839 bufsize
= ssh2_try_send(c
);
5842 case CHAN_MAINSESSION
:
5843 /* stdin need not receive an unthrottle
5844 * notification since it will be polled */
5847 x11_unthrottle(c
->u
.x11
.s
);
5850 /* agent sockets are request/response and need no
5851 * buffer management */
5854 pfd_unthrottle(c
->u
.pfd
.s
);
5866 * Handle the top-level SSH2 protocol.
5868 static void ssh2_protocol(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
5870 if (do_ssh2_transport(ssh
, in
, inlen
, ispkt
) == 0)
5872 do_ssh2_authconn(ssh
, in
, inlen
, ispkt
);
5876 * Called to set up the connection.
5878 * Returns an error message, or NULL on success.
5880 static char *ssh_init(void *frontend_handle
, void **backend_handle
,
5882 char *host
, int port
, char **realhost
, int nodelay
)
5887 ssh
= smalloc(sizeof(*ssh
));
5888 ssh
->cfg
= *cfg
; /* STRUCTURE COPY */
5891 ssh
->v1_cipher_ctx
= NULL
;
5892 ssh
->crcda_ctx
= NULL
;
5893 ssh
->cscipher
= NULL
;
5894 ssh
->cs_cipher_ctx
= NULL
;
5895 ssh
->sccipher
= NULL
;
5896 ssh
->sc_cipher_ctx
= NULL
;
5898 ssh
->cs_mac_ctx
= NULL
;
5900 ssh
->sc_mac_ctx
= NULL
;
5902 ssh
->cs_comp_ctx
= NULL
;
5904 ssh
->sc_comp_ctx
= NULL
;
5906 ssh
->hostkey
= NULL
;
5908 ssh
->state
= SSH_STATE_PREPACKET
;
5909 ssh
->size_needed
= FALSE
;
5910 ssh
->eof_needed
= FALSE
;
5914 static const struct Packet empty
= { 0, 0, NULL
, NULL
, 0 };
5915 ssh
->pktin
= ssh
->pktout
= empty
;
5917 ssh
->deferred_send_data
= NULL
;
5918 ssh
->deferred_len
= 0;
5919 ssh
->deferred_size
= 0;
5920 ssh
->fallback_cmd
= 0;
5922 ssh
->x11auth
= NULL
;
5923 ssh
->v1_compressing
= FALSE
;
5924 ssh
->v2_outgoing_sequence
= 0;
5925 ssh
->ssh1_rdpkt_crstate
= 0;
5926 ssh
->ssh2_rdpkt_crstate
= 0;
5927 ssh
->do_ssh_init_crstate
= 0;
5928 ssh
->ssh_gotdata_crstate
= 0;
5929 ssh
->ssh1_protocol_crstate
= 0;
5930 ssh
->do_ssh1_login_crstate
= 0;
5931 ssh
->do_ssh2_transport_crstate
= 0;
5932 ssh
->do_ssh2_authconn_crstate
= 0;
5933 ssh
->do_ssh_init_state
= NULL
;
5934 ssh
->do_ssh1_login_state
= NULL
;
5935 ssh
->do_ssh2_transport_state
= NULL
;
5936 ssh
->do_ssh2_authconn_state
= NULL
;
5937 ssh
->mainchan
= NULL
;
5938 ssh
->throttled_all
= 0;
5939 ssh
->v1_stdout_throttling
= 0;
5941 *backend_handle
= ssh
;
5944 if (crypto_startup() == 0)
5945 return "Microsoft high encryption pack not installed!";
5948 ssh
->frontend
= frontend_handle
;
5949 ssh
->term_width
= ssh
->cfg
.width
;
5950 ssh
->term_height
= ssh
->cfg
.height
;
5952 ssh
->channels
= NULL
;
5953 ssh
->rportfwds
= NULL
;
5958 ssh
->v1_throttle_count
= 0;
5959 ssh
->overall_bufsize
= 0;
5960 ssh
->fallback_cmd
= 0;
5962 ssh
->protocol
= NULL
;
5964 p
= connect_to_host(ssh
, host
, port
, realhost
, nodelay
);
5971 static void ssh_free(void *handle
)
5973 Ssh ssh
= (Ssh
) handle
;
5974 struct ssh_channel
*c
;
5975 struct ssh_rportfwd
*pf
;
5977 if (ssh
->v1_cipher_ctx
)
5978 ssh
->cipher
->free_context(ssh
->v1_cipher_ctx
);
5979 if (ssh
->cs_cipher_ctx
)
5980 ssh
->cscipher
->free_context(ssh
->cs_cipher_ctx
);
5981 if (ssh
->sc_cipher_ctx
)
5982 ssh
->sccipher
->free_context(ssh
->sc_cipher_ctx
);
5983 if (ssh
->cs_mac_ctx
)
5984 ssh
->csmac
->free_context(ssh
->cs_mac_ctx
);
5985 if (ssh
->sc_mac_ctx
)
5986 ssh
->scmac
->free_context(ssh
->sc_mac_ctx
);
5987 if (ssh
->cs_comp_ctx
)
5988 ssh
->cscomp
->compress_cleanup(ssh
->cs_comp_ctx
);
5989 if (ssh
->sc_comp_ctx
)
5990 ssh
->sccomp
->compress_cleanup(ssh
->sc_comp_ctx
);
5992 dh_cleanup(ssh
->kex_ctx
);
5993 sfree(ssh
->savedhost
);
5995 if (ssh
->channels
) {
5996 while ((c
= delpos234(ssh
->channels
, 0)) != NULL
) {
5999 if (c
->u
.x11
.s
!= NULL
)
6000 x11_close(c
->u
.x11
.s
);
6003 if (c
->u
.pfd
.s
!= NULL
)
6004 pfd_close(c
->u
.pfd
.s
);
6009 freetree234(ssh
->channels
);
6012 if (ssh
->rportfwds
) {
6013 while ((pf
= delpos234(ssh
->rportfwds
, 0)) != NULL
)
6015 freetree234(ssh
->rportfwds
);
6017 sfree(ssh
->deferred_send_data
);
6019 x11_free_auth(ssh
->x11auth
);
6020 sfree(ssh
->do_ssh_init_state
);
6021 sfree(ssh
->do_ssh1_login_state
);
6022 sfree(ssh
->do_ssh2_transport_state
);
6023 sfree(ssh
->do_ssh2_authconn_state
);
6031 * Reconfigure the SSH backend.
6033 * Currently, this function does nothing very useful. In future,
6034 * however, we could do some handy things with it. For example, we
6035 * could make the port forwarding configurer active in the Change
6036 * Settings box, and this routine could close down existing
6037 * forwardings and open up new ones in response to changes.
6039 static void ssh_reconfig(void *handle
, Config
*cfg
)
6041 Ssh ssh
= (Ssh
) handle
;
6042 ssh
->cfg
= *cfg
; /* STRUCTURE COPY */
6046 * Called to send data down the Telnet connection.
6048 static int ssh_send(void *handle
, char *buf
, int len
)
6050 Ssh ssh
= (Ssh
) handle
;
6052 if (ssh
== NULL
|| ssh
->s
== NULL
|| ssh
->protocol
== NULL
)
6055 ssh
->protocol(ssh
, (unsigned char *)buf
, len
, 0);
6057 return ssh_sendbuffer(ssh
);
6061 * Called to query the current amount of buffered stdin data.
6063 static int ssh_sendbuffer(void *handle
)
6065 Ssh ssh
= (Ssh
) handle
;
6068 if (ssh
== NULL
|| ssh
->s
== NULL
|| ssh
->protocol
== NULL
)
6072 * If the SSH socket itself has backed up, add the total backup
6073 * size on that to any individual buffer on the stdin channel.
6076 if (ssh
->throttled_all
)
6077 override_value
= ssh
->overall_bufsize
;
6079 if (ssh
->version
== 1) {
6080 return override_value
;
6081 } else if (ssh
->version
== 2) {
6082 if (!ssh
->mainchan
|| ssh
->mainchan
->closes
> 0)
6083 return override_value
;
6085 return (override_value
+
6086 bufchain_size(&ssh
->mainchan
->v
.v2
.outbuffer
));
6093 * Called to set the size of the window from SSH's POV.
6095 static void ssh_size(void *handle
, int width
, int height
)
6097 Ssh ssh
= (Ssh
) handle
;
6099 ssh
->term_width
= width
;
6100 ssh
->term_height
= height
;
6102 switch (ssh
->state
) {
6103 case SSH_STATE_BEFORE_SIZE
:
6104 case SSH_STATE_PREPACKET
:
6105 case SSH_STATE_CLOSED
:
6106 break; /* do nothing */
6107 case SSH_STATE_INTERMED
:
6108 ssh
->size_needed
= TRUE
; /* buffer for later */
6110 case SSH_STATE_SESSION
:
6111 if (!ssh
->cfg
.nopty
) {
6112 if (ssh
->version
== 1) {
6113 send_packet(ssh
, SSH1_CMSG_WINDOW_SIZE
,
6114 PKT_INT
, ssh
->term_height
,
6115 PKT_INT
, ssh
->term_width
,
6116 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
6118 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
6119 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
6120 ssh2_pkt_addstring(ssh
, "window-change");
6121 ssh2_pkt_addbool(ssh
, 0);
6122 ssh2_pkt_adduint32(ssh
, ssh
->term_width
);
6123 ssh2_pkt_adduint32(ssh
, ssh
->term_height
);
6124 ssh2_pkt_adduint32(ssh
, 0);
6125 ssh2_pkt_adduint32(ssh
, 0);
6134 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6135 * can send an EOF and collect resulting output (e.g. `plink
6138 static void ssh_special(void *handle
, Telnet_Special code
)
6140 Ssh ssh
= (Ssh
) handle
;
6142 if (code
== TS_EOF
) {
6143 if (ssh
->state
!= SSH_STATE_SESSION
) {
6145 * Buffer the EOF in case we are pre-SESSION, so we can
6146 * send it as soon as we reach SESSION.
6149 ssh
->eof_needed
= TRUE
;
6152 if (ssh
->version
== 1) {
6153 send_packet(ssh
, SSH1_CMSG_EOF
, PKT_END
);
6155 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_EOF
);
6156 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
6159 logevent("Sent EOF message");
6160 } else if (code
== TS_PING
) {
6161 if (ssh
->state
== SSH_STATE_CLOSED
6162 || ssh
->state
== SSH_STATE_PREPACKET
) return;
6163 if (ssh
->version
== 1) {
6164 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
))
6165 send_packet(ssh
, SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
6167 ssh2_pkt_init(ssh
, SSH2_MSG_IGNORE
);
6168 ssh2_pkt_addstring_start(ssh
);
6176 void *new_sock_channel(void *handle
, Socket s
)
6178 Ssh ssh
= (Ssh
) handle
;
6179 struct ssh_channel
*c
;
6180 c
= smalloc(sizeof(struct ssh_channel
));
6184 c
->remoteid
= -1; /* to be set when open confirmed */
6185 c
->localid
= alloc_channel_id(ssh
);
6187 c
->type
= CHAN_SOCKDATA_DORMANT
;/* identify channel type */
6189 bufchain_init(&c
->v
.v2
.outbuffer
);
6190 add234(ssh
->channels
, c
);
6196 * This is called when stdout/stderr (the entity to which
6197 * from_backend sends data) manages to clear some backlog.
6199 static void ssh_unthrottle(void *handle
, int bufsize
)
6201 Ssh ssh
= (Ssh
) handle
;
6202 if (ssh
->version
== 1) {
6203 if (ssh
->v1_stdout_throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
6204 ssh
->v1_stdout_throttling
= 0;
6205 ssh1_throttle(ssh
, -1);
6208 if (ssh
->mainchan
&& ssh
->mainchan
->closes
== 0)
6209 ssh2_set_window(ssh
->mainchan
, OUR_V2_WINSIZE
- bufsize
);
6213 void ssh_send_port_open(void *channel
, char *hostname
, int port
, char *org
)
6215 struct ssh_channel
*c
= (struct ssh_channel
*)channel
;
6218 logeventf(ssh
, "Opening forwarded connection to %s:%d", hostname
, port
);
6220 if (ssh
->version
== 1) {
6221 send_packet(ssh
, SSH1_MSG_PORT_OPEN
,
6222 PKT_INT
, c
->localid
,
6225 //PKT_STR, <org:orgport>,
6228 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN
);
6229 ssh2_pkt_addstring(ssh
, "direct-tcpip");
6230 ssh2_pkt_adduint32(ssh
, c
->localid
);
6231 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
6232 ssh2_pkt_adduint32(ssh
, c
->v
.v2
.locwindow
);/* our window size */
6233 ssh2_pkt_adduint32(ssh
, 0x4000UL
); /* our max pkt size */
6234 ssh2_pkt_addstring(ssh
, hostname
);
6235 ssh2_pkt_adduint32(ssh
, port
);
6237 * We make up values for the originator data; partly it's
6238 * too much hassle to keep track, and partly I'm not
6239 * convinced the server should be told details like that
6240 * about my local network configuration.
6242 ssh2_pkt_addstring(ssh
, "client-side-connection");
6243 ssh2_pkt_adduint32(ssh
, 0);
6249 static Socket
ssh_socket(void *handle
)
6251 Ssh ssh
= (Ssh
) handle
;
6255 static int ssh_sendok(void *handle
)
6257 Ssh ssh
= (Ssh
) handle
;
6258 return ssh
->send_ok
;
6261 static int ssh_ldisc(void *handle
, int option
)
6263 Ssh ssh
= (Ssh
) handle
;
6264 if (option
== LD_ECHO
)
6265 return ssh
->echoing
;
6266 if (option
== LD_EDIT
)
6267 return ssh
->editing
;
6271 static void ssh_provide_ldisc(void *handle
, void *ldisc
)
6273 Ssh ssh
= (Ssh
) handle
;
6277 static void ssh_provide_logctx(void *handle
, void *logctx
)
6279 Ssh ssh
= (Ssh
) handle
;
6280 ssh
->logctx
= logctx
;
6283 static int ssh_return_exitcode(void *handle
)
6285 Ssh ssh
= (Ssh
) handle
;
6286 return ssh
->exitcode
;
6290 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6291 * that fails. This variable is the means by which scp.c can reach
6292 * into the SSH code and find out which one it got.
6294 extern int ssh_fallback_cmd(void *handle
)
6296 Ssh ssh
= (Ssh
) handle
;
6297 return ssh
->fallback_cmd
;
6300 Backend ssh_backend
= {
6309 ssh_return_exitcode
,