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
166 #define BUG_SSH2_PK_SESSIONID 128
168 #define translate(x) if (type == x) return #x
169 #define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
170 static char *ssh1_pkt_type(int type
)
172 translate(SSH1_MSG_DISCONNECT
);
173 translate(SSH1_SMSG_PUBLIC_KEY
);
174 translate(SSH1_CMSG_SESSION_KEY
);
175 translate(SSH1_CMSG_USER
);
176 translate(SSH1_CMSG_AUTH_RSA
);
177 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE
);
178 translate(SSH1_CMSG_AUTH_RSA_RESPONSE
);
179 translate(SSH1_CMSG_AUTH_PASSWORD
);
180 translate(SSH1_CMSG_REQUEST_PTY
);
181 translate(SSH1_CMSG_WINDOW_SIZE
);
182 translate(SSH1_CMSG_EXEC_SHELL
);
183 translate(SSH1_CMSG_EXEC_CMD
);
184 translate(SSH1_SMSG_SUCCESS
);
185 translate(SSH1_SMSG_FAILURE
);
186 translate(SSH1_CMSG_STDIN_DATA
);
187 translate(SSH1_SMSG_STDOUT_DATA
);
188 translate(SSH1_SMSG_STDERR_DATA
);
189 translate(SSH1_CMSG_EOF
);
190 translate(SSH1_SMSG_EXIT_STATUS
);
191 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
);
192 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE
);
193 translate(SSH1_MSG_CHANNEL_DATA
);
194 translate(SSH1_MSG_CHANNEL_CLOSE
);
195 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
);
196 translate(SSH1_SMSG_X11_OPEN
);
197 translate(SSH1_CMSG_PORT_FORWARD_REQUEST
);
198 translate(SSH1_MSG_PORT_OPEN
);
199 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING
);
200 translate(SSH1_SMSG_AGENT_OPEN
);
201 translate(SSH1_MSG_IGNORE
);
202 translate(SSH1_CMSG_EXIT_CONFIRMATION
);
203 translate(SSH1_CMSG_X11_REQUEST_FORWARDING
);
204 translate(SSH1_CMSG_AUTH_RHOSTS_RSA
);
205 translate(SSH1_MSG_DEBUG
);
206 translate(SSH1_CMSG_REQUEST_COMPRESSION
);
207 translate(SSH1_CMSG_AUTH_TIS
);
208 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE
);
209 translate(SSH1_CMSG_AUTH_TIS_RESPONSE
);
210 translate(SSH1_CMSG_AUTH_CCARD
);
211 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE
);
212 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE
);
215 static char *ssh2_pkt_type(int pkt_ctx
, int type
)
217 translate(SSH2_MSG_DISCONNECT
);
218 translate(SSH2_MSG_IGNORE
);
219 translate(SSH2_MSG_UNIMPLEMENTED
);
220 translate(SSH2_MSG_DEBUG
);
221 translate(SSH2_MSG_SERVICE_REQUEST
);
222 translate(SSH2_MSG_SERVICE_ACCEPT
);
223 translate(SSH2_MSG_KEXINIT
);
224 translate(SSH2_MSG_NEWKEYS
);
225 translatec(SSH2_MSG_KEXDH_INIT
, SSH2_PKTCTX_DHGROUP1
);
226 translatec(SSH2_MSG_KEXDH_REPLY
, SSH2_PKTCTX_DHGROUP1
);
227 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST
, SSH2_PKTCTX_DHGEX
);
228 translatec(SSH2_MSG_KEX_DH_GEX_GROUP
, SSH2_PKTCTX_DHGEX
);
229 translatec(SSH2_MSG_KEX_DH_GEX_INIT
, SSH2_PKTCTX_DHGEX
);
230 translatec(SSH2_MSG_KEX_DH_GEX_REPLY
, SSH2_PKTCTX_DHGEX
);
231 translate(SSH2_MSG_USERAUTH_REQUEST
);
232 translate(SSH2_MSG_USERAUTH_FAILURE
);
233 translate(SSH2_MSG_USERAUTH_SUCCESS
);
234 translate(SSH2_MSG_USERAUTH_BANNER
);
235 translatec(SSH2_MSG_USERAUTH_PK_OK
, SSH2_PKTCTX_PUBLICKEY
);
236 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ
, SSH2_PKTCTX_PASSWORD
);
237 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST
, SSH2_PKTCTX_KBDINTER
);
238 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE
, SSH2_PKTCTX_KBDINTER
);
239 translate(SSH2_MSG_GLOBAL_REQUEST
);
240 translate(SSH2_MSG_REQUEST_SUCCESS
);
241 translate(SSH2_MSG_REQUEST_FAILURE
);
242 translate(SSH2_MSG_CHANNEL_OPEN
);
243 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
244 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE
);
245 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
246 translate(SSH2_MSG_CHANNEL_DATA
);
247 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA
);
248 translate(SSH2_MSG_CHANNEL_EOF
);
249 translate(SSH2_MSG_CHANNEL_CLOSE
);
250 translate(SSH2_MSG_CHANNEL_REQUEST
);
251 translate(SSH2_MSG_CHANNEL_SUCCESS
);
252 translate(SSH2_MSG_CHANNEL_FAILURE
);
258 #define GET_32BIT(cp) \
259 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
260 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
261 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
262 ((unsigned long)(unsigned char)(cp)[3]))
264 #define PUT_32BIT(cp, value) { \
265 (cp)[0] = (unsigned char)((value) >> 24); \
266 (cp)[1] = (unsigned char)((value) >> 16); \
267 (cp)[2] = (unsigned char)((value) >> 8); \
268 (cp)[3] = (unsigned char)(value); }
270 enum { PKT_END
, PKT_INT
, PKT_CHAR
, PKT_DATA
, PKT_STR
, PKT_BIGNUM
};
272 /* Coroutine mechanics for the sillier bits of the code */
273 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
276 if (!ssh->t) ssh->t = smalloc(sizeof(struct t)); \
278 #define crFinish(z) } *crLine = 0; return (z); }
279 #define crFinishV } *crLine = 0; return; }
280 #define crReturn(z) \
282 *crLine =__LINE__; return (z); case __LINE__:;\
286 *crLine=__LINE__; return; case __LINE__:;\
288 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
289 #define crStopV do{ *crLine = 0; return; }while(0)
290 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
291 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
293 typedef struct ssh_tag
*Ssh
;
295 static void ssh2_pkt_init(Ssh
, int pkt_type
);
296 static void ssh2_pkt_addbool(Ssh
, unsigned char value
);
297 static void ssh2_pkt_adduint32(Ssh
, unsigned long value
);
298 static void ssh2_pkt_addstring_start(Ssh
);
299 static void ssh2_pkt_addstring_str(Ssh
, char *data
);
300 static void ssh2_pkt_addstring_data(Ssh
, char *data
, int len
);
301 static void ssh2_pkt_addstring(Ssh
, char *data
);
302 static unsigned char *ssh2_mpint_fmt(Bignum b
, int *len
);
303 static void ssh2_pkt_addmp(Ssh
, Bignum b
);
304 static int ssh2_pkt_construct(Ssh
);
305 static void ssh2_pkt_send(Ssh
);
308 * Buffer management constants. There are several of these for
309 * various different purposes:
311 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
312 * on a local data stream before we throttle the whole SSH
313 * connection (in SSH1 only). Throttling the whole connection is
314 * pretty drastic so we set this high in the hope it won't
317 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
318 * on the SSH connection itself before we defensively throttle
319 * _all_ local data streams. This is pretty drastic too (though
320 * thankfully unlikely in SSH2 since the window mechanism should
321 * ensure that the server never has any need to throttle its end
322 * of the connection), so we set this high as well.
324 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
328 #define SSH1_BUFFER_LIMIT 32768
329 #define SSH_MAX_BACKLOG 32768
330 #define OUR_V2_WINSIZE 16384
332 const static struct ssh_kex
*kex_algs
[] = {
333 &ssh_diffiehellman_gex
,
337 const static struct ssh_signkey
*hostkey_algs
[] = { &ssh_rsa
, &ssh_dss
};
339 static void *nullmac_make_context(void)
343 static void nullmac_free_context(void *handle
)
346 static void nullmac_key(void *handle
, unsigned char *key
)
349 static void nullmac_generate(void *handle
, unsigned char *blk
, int len
,
353 static int nullmac_verify(void *handle
, unsigned char *blk
, int len
,
358 const static struct ssh_mac ssh_mac_none
= {
359 nullmac_make_context
, nullmac_free_context
, nullmac_key
,
360 nullmac_generate
, nullmac_verify
, "none", 0
362 const static struct ssh_mac
*macs
[] = {
363 &ssh_sha1
, &ssh_md5
, &ssh_mac_none
365 const static struct ssh_mac
*buggymacs
[] = {
366 &ssh_sha1_buggy
, &ssh_md5
, &ssh_mac_none
369 static void *ssh_comp_none_init(void)
373 static void ssh_comp_none_cleanup(void *handle
)
376 static int ssh_comp_none_block(void *handle
, unsigned char *block
, int len
,
377 unsigned char **outblock
, int *outlen
)
381 static int ssh_comp_none_disable(void *handle
)
385 const static struct ssh_compress ssh_comp_none
= {
387 ssh_comp_none_init
, ssh_comp_none_cleanup
, ssh_comp_none_block
,
388 ssh_comp_none_init
, ssh_comp_none_cleanup
, ssh_comp_none_block
,
389 ssh_comp_none_disable
, NULL
391 extern const struct ssh_compress ssh_zlib
;
392 const static struct ssh_compress
*compressions
[] = {
393 &ssh_zlib
, &ssh_comp_none
396 enum { /* channel types */
401 CHAN_SOCKDATA_DORMANT
/* one the remote hasn't confirmed */
405 * 2-3-4 tree storing channels.
408 Ssh ssh
; /* pointer back to main context */
409 unsigned remoteid
, localid
;
412 * In SSH1, this value contains four bits:
414 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
415 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
416 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
417 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
419 * A channel is completely finished with when all four bits are set.
423 struct ssh1_data_channel
{
426 struct ssh2_data_channel
{
428 unsigned remwindow
, remmaxpkt
;
433 struct ssh_agent_channel
{
434 unsigned char *message
;
435 unsigned char msglen
[4];
436 int lensofar
, totallen
;
438 struct ssh_x11_channel
{
441 struct ssh_pfd_channel
{
448 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
449 * 2 use this structure in different ways, reflecting SSH 2's
450 * altogether saner approach to port forwarding.
452 * In SSH 1, you arrange a remote forwarding by sending the server
453 * the remote port number, and the local destination host:port.
454 * When a connection comes in, the server sends you back that
455 * host:port pair, and you connect to it. This is a ready-made
456 * security hole if you're not on the ball: a malicious server
457 * could send you back _any_ host:port pair, so if you trustingly
458 * connect to the address it gives you then you've just opened the
459 * entire inside of your corporate network just by connecting
460 * through it to a dodgy SSH server. Hence, we must store a list of
461 * host:port pairs we _are_ trying to forward to, and reject a
462 * connection request from the server if it's not in the list.
464 * In SSH 2, each side of the connection minds its own business and
465 * doesn't send unnecessary information to the other. You arrange a
466 * remote forwarding by sending the server just the remote port
467 * number. When a connection comes in, the server tells you which
468 * of its ports was connected to; and _you_ have to remember what
469 * local host:port pair went with that port number.
471 * Hence: in SSH 1 this structure stores host:port pairs we intend
472 * to allow connections to, and is indexed by those host:port
473 * pairs. In SSH 2 it stores a mapping from source port to
474 * destination host:port pair, and is indexed by source port.
476 struct ssh_rportfwd
{
477 unsigned sport
, dport
;
490 static void ssh1_protocol(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
);
491 static void ssh2_protocol(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
);
492 static void ssh_size(void *handle
, int width
, int height
);
493 static void ssh_special(void *handle
, Telnet_Special
);
494 static int ssh2_try_send(struct ssh_channel
*c
);
495 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
, int len
);
496 static void ssh_throttle_all(Ssh ssh
, int enable
, int bufsize
);
497 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
);
498 static int ssh_sendbuffer(void *handle
);
500 struct rdpkt1_state_tag
{
501 long len
, pad
, biglen
, to_read
;
502 unsigned long realcrc
, gotcrc
;
508 struct rdpkt2_state_tag
{
509 long len
, pad
, payload
, packetlen
, maclen
;
512 unsigned long incoming_sequence
;
516 const struct plug_function_table
*fn
;
517 /* the above field _must_ be first in the structure */
519 SHA_State exhash
, exhashbase
;
526 unsigned char session_key
[32];
528 int v1_remote_protoflags
;
529 int v1_local_protoflags
;
530 int agentfwd_enabled
;
533 const struct ssh_cipher
*cipher
;
536 const struct ssh2_cipher
*cscipher
, *sccipher
;
537 void *cs_cipher_ctx
, *sc_cipher_ctx
;
538 const struct ssh_mac
*csmac
, *scmac
;
539 void *cs_mac_ctx
, *sc_mac_ctx
;
540 const struct ssh_compress
*cscomp
, *sccomp
;
541 void *cs_comp_ctx
, *sc_comp_ctx
;
542 const struct ssh_kex
*kex
;
543 const struct ssh_signkey
*hostkey
;
544 unsigned char v2_session_id
[20];
550 int echoing
, editing
;
554 int term_width
, term_height
;
556 tree234
*channels
; /* indexed by local id */
557 struct ssh_channel
*mainchan
; /* primary session channel */
564 SSH_STATE_BEFORE_SIZE
,
570 int size_needed
, eof_needed
;
573 struct Packet pktout
;
574 unsigned char *deferred_send_data
;
575 int deferred_len
, deferred_size
;
578 * Gross hack: pscp will try to start SFTP but fall back to
579 * scp1 if that fails. This variable is the means by which
580 * scp.c can reach into the SSH code and find out which one it
586 * Used for username and password input.
588 char *userpass_input_buffer
;
589 int userpass_input_buflen
;
590 int userpass_input_bufpos
;
591 int userpass_input_echo
;
593 char *portfwd_strptr
;
599 int v1_throttle_count
;
602 int v1_stdout_throttling
;
603 int v2_outgoing_sequence
;
605 int ssh1_rdpkt_crstate
;
606 int ssh2_rdpkt_crstate
;
607 int do_ssh_init_crstate
;
608 int ssh_gotdata_crstate
;
609 int ssh1_protocol_crstate
;
610 int do_ssh1_login_crstate
;
611 int do_ssh2_transport_crstate
;
612 int do_ssh2_authconn_crstate
;
614 void *do_ssh_init_state
;
615 void *do_ssh1_login_state
;
616 void *do_ssh2_transport_state
;
617 void *do_ssh2_authconn_state
;
619 struct rdpkt1_state_tag rdpkt1_state
;
620 struct rdpkt2_state_tag rdpkt2_state
;
622 void (*protocol
) (Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
);
623 int (*s_rdpkt
) (Ssh ssh
, unsigned char **data
, int *datalen
);
626 * We maintain a full _copy_ of a Config structure here, not
627 * merely a pointer to it. That way, when we're passed a new
628 * one for reconfiguration, we can check the differences and
629 * potentially reconfigure port forwardings etc in mid-session.
634 #define logevent(s) logevent(ssh->frontend, s)
636 /* logevent, only printf-formatted. */
637 static void logeventf(Ssh ssh
, char *fmt
, ...)
643 buf
= dupvprintf(fmt
, ap
);
649 #define bombout(msg) ( ssh->state = SSH_STATE_CLOSED, \
650 (ssh->s ? sk_close(ssh->s), ssh->s = NULL : 0), \
651 logeventf msg, connection_fatal msg )
653 static int ssh_channelcmp(void *av
, void *bv
)
655 struct ssh_channel
*a
= (struct ssh_channel
*) av
;
656 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
657 if (a
->localid
< b
->localid
)
659 if (a
->localid
> b
->localid
)
663 static int ssh_channelfind(void *av
, void *bv
)
665 unsigned *a
= (unsigned *) av
;
666 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
674 static int ssh_rportcmp_ssh1(void *av
, void *bv
)
676 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
677 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
679 if ( (i
= strcmp(a
->dhost
, b
->dhost
)) != 0)
680 return i
< 0 ?
-1 : +1;
681 if (a
->dport
> b
->dport
)
683 if (a
->dport
< b
->dport
)
688 static int ssh_rportcmp_ssh2(void *av
, void *bv
)
690 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
691 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
693 if (a
->sport
> b
->sport
)
695 if (a
->sport
< b
->sport
)
700 static int alloc_channel_id(Ssh ssh
)
702 const unsigned CHANNEL_NUMBER_OFFSET
= 256;
703 unsigned low
, high
, mid
;
705 struct ssh_channel
*c
;
708 * First-fit allocation of channel numbers: always pick the
709 * lowest unused one. To do this, binary-search using the
710 * counted B-tree to find the largest channel ID which is in a
711 * contiguous sequence from the beginning. (Precisely
712 * everything in that sequence must have ID equal to its tree
713 * index plus CHANNEL_NUMBER_OFFSET.)
715 tsize
= count234(ssh
->channels
);
719 while (high
- low
> 1) {
720 mid
= (high
+ low
) / 2;
721 c
= index234(ssh
->channels
, mid
);
722 if (c
->localid
== mid
+ CHANNEL_NUMBER_OFFSET
)
723 low
= mid
; /* this one is fine */
725 high
= mid
; /* this one is past it */
728 * Now low points to either -1, or the tree index of the
729 * largest ID in the initial sequence.
732 unsigned i
= low
+ 1 + CHANNEL_NUMBER_OFFSET
;
733 assert(NULL
== find234(ssh
->channels
, &i
, ssh_channelfind
));
735 return low
+ 1 + CHANNEL_NUMBER_OFFSET
;
738 static void c_write(Ssh ssh
, const char *buf
, int len
)
740 if ((flags
& FLAG_STDERR
)) {
742 for (i
= 0; i
< len
; i
++)
744 fputc(buf
[i
], stderr
);
747 from_backend(ssh
->frontend
, 1, buf
, len
);
750 static void c_write_untrusted(Ssh ssh
, const char *buf
, int len
)
753 for (i
= 0; i
< len
; i
++) {
755 c_write(ssh
, "\r\n", 2);
756 else if ((buf
[i
] & 0x60) || (buf
[i
] == '\r'))
757 c_write(ssh
, buf
+ i
, 1);
761 static void c_write_str(Ssh ssh
, const char *buf
)
763 c_write(ssh
, buf
, strlen(buf
));
767 * Collect incoming data in the incoming packet buffer.
768 * Decipher and verify the packet when it is completely read.
769 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
770 * Update the *data and *datalen variables.
771 * Return the additional nr of bytes needed, or 0 when
772 * a complete packet is available.
774 static int ssh1_rdpkt(Ssh ssh
, unsigned char **data
, int *datalen
)
776 struct rdpkt1_state_tag
*st
= &ssh
->rdpkt1_state
;
778 crBegin(ssh
->ssh1_rdpkt_crstate
);
783 ssh
->pktin
.length
= 0;
785 for (st
->i
= st
->len
= 0; st
->i
< 4; st
->i
++) {
786 while ((*datalen
) == 0)
788 st
->len
= (st
->len
<< 8) + **data
;
789 (*data
)++, (*datalen
)--;
792 st
->pad
= 8 - (st
->len
% 8);
793 st
->biglen
= st
->len
+ st
->pad
;
794 ssh
->pktin
.length
= st
->len
- 5;
796 if (ssh
->pktin
.maxlen
< st
->biglen
) {
797 ssh
->pktin
.maxlen
= st
->biglen
;
798 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
, st
->biglen
+ APIEXTRA
);
801 st
->to_read
= st
->biglen
;
802 st
->p
= ssh
->pktin
.data
;
803 while (st
->to_read
> 0) {
804 st
->chunk
= st
->to_read
;
805 while ((*datalen
) == 0)
806 crReturn(st
->to_read
);
807 if (st
->chunk
> (*datalen
))
808 st
->chunk
= (*datalen
);
809 memcpy(st
->p
, *data
, st
->chunk
);
811 *datalen
-= st
->chunk
;
813 st
->to_read
-= st
->chunk
;
816 if (ssh
->cipher
&& detect_attack(ssh
->crcda_ctx
, ssh
->pktin
.data
,
818 bombout((ssh
,"Network attack (CRC compensation) detected!"));
823 ssh
->cipher
->decrypt(ssh
->v1_cipher_ctx
, ssh
->pktin
.data
, st
->biglen
);
825 st
->realcrc
= crc32(ssh
->pktin
.data
, st
->biglen
- 4);
826 st
->gotcrc
= GET_32BIT(ssh
->pktin
.data
+ st
->biglen
- 4);
827 if (st
->gotcrc
!= st
->realcrc
) {
828 bombout((ssh
,"Incorrect CRC received on packet"));
832 ssh
->pktin
.body
= ssh
->pktin
.data
+ st
->pad
+ 1;
834 if (ssh
->v1_compressing
) {
835 unsigned char *decompblk
;
837 zlib_decompress_block(ssh
->sc_comp_ctx
,
838 ssh
->pktin
.body
- 1, ssh
->pktin
.length
+ 1,
839 &decompblk
, &decomplen
);
841 if (ssh
->pktin
.maxlen
< st
->pad
+ decomplen
) {
842 ssh
->pktin
.maxlen
= st
->pad
+ decomplen
;
843 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
,
844 ssh
->pktin
.maxlen
+ APIEXTRA
);
845 ssh
->pktin
.body
= ssh
->pktin
.data
+ st
->pad
+ 1;
848 memcpy(ssh
->pktin
.body
- 1, decompblk
, decomplen
);
850 ssh
->pktin
.length
= decomplen
- 1;
853 ssh
->pktin
.type
= ssh
->pktin
.body
[-1];
856 log_packet(ssh
->logctx
,
857 PKT_INCOMING
, ssh
->pktin
.type
,
858 ssh1_pkt_type(ssh
->pktin
.type
),
859 ssh
->pktin
.body
, ssh
->pktin
.length
);
861 if (ssh
->pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
862 ssh
->pktin
.type
== SSH1_SMSG_STDERR_DATA
||
863 ssh
->pktin
.type
== SSH1_MSG_DEBUG
||
864 ssh
->pktin
.type
== SSH1_SMSG_AUTH_TIS_CHALLENGE
||
865 ssh
->pktin
.type
== SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
866 long stringlen
= GET_32BIT(ssh
->pktin
.body
);
867 if (stringlen
+ 4 != ssh
->pktin
.length
) {
868 bombout((ssh
,"Received data packet with bogus string length"));
873 if (ssh
->pktin
.type
== SSH1_MSG_DEBUG
) {
874 /* log debug message */
876 int stringlen
= GET_32BIT(ssh
->pktin
.body
);
877 strcpy(buf
, "Remote debug message: ");
880 memcpy(buf
+ 8, ssh
->pktin
.body
+ 4, stringlen
);
881 buf
[8 + stringlen
] = '\0';
884 } else if (ssh
->pktin
.type
== SSH1_MSG_IGNORE
) {
889 if (ssh
->pktin
.type
== SSH1_MSG_DISCONNECT
) {
890 /* log reason code in disconnect message */
892 unsigned msglen
= GET_32BIT(ssh
->pktin
.body
);
894 strcpy(buf
, "Remote sent disconnect: ");
895 nowlen
= strlen(buf
);
896 if (msglen
> sizeof(buf
) - nowlen
- 1)
897 msglen
= sizeof(buf
) - nowlen
- 1;
898 memcpy(buf
+ nowlen
, ssh
->pktin
.body
+ 4, msglen
);
899 buf
[nowlen
+ msglen
] = '\0';
900 /* logevent(buf); (this is now done within the bombout macro) */
901 bombout((ssh
,"Server sent disconnect message:\n\"%s\"", buf
+nowlen
));
908 static int ssh2_rdpkt(Ssh ssh
, unsigned char **data
, int *datalen
)
910 struct rdpkt2_state_tag
*st
= &ssh
->rdpkt2_state
;
912 crBegin(ssh
->ssh2_rdpkt_crstate
);
916 ssh
->pktin
.length
= 0;
918 st
->cipherblk
= ssh
->sccipher
->blksize
;
921 if (st
->cipherblk
< 8)
924 if (ssh
->pktin
.maxlen
< st
->cipherblk
) {
925 ssh
->pktin
.maxlen
= st
->cipherblk
;
926 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
, st
->cipherblk
+ APIEXTRA
);
930 * Acquire and decrypt the first block of the packet. This will
931 * contain the length and padding details.
933 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
934 while ((*datalen
) == 0)
935 crReturn(st
->cipherblk
- st
->i
);
936 ssh
->pktin
.data
[st
->i
] = *(*data
)++;
941 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
942 ssh
->pktin
.data
, st
->cipherblk
);
945 * Now get the length and padding figures.
947 st
->len
= GET_32BIT(ssh
->pktin
.data
);
948 st
->pad
= ssh
->pktin
.data
[4];
951 * _Completely_ silly lengths should be stomped on before they
952 * do us any more damage.
954 if (st
->len
< 0 || st
->pad
< 0 || st
->len
+ st
->pad
< 0) {
955 bombout((ssh
,"Incoming packet was garbled on decryption"));
960 * This enables us to deduce the payload length.
962 st
->payload
= st
->len
- st
->pad
- 1;
964 ssh
->pktin
.length
= st
->payload
+ 5;
967 * So now we can work out the total packet length.
969 st
->packetlen
= st
->len
+ 4;
970 st
->maclen
= ssh
->scmac ? ssh
->scmac
->len
: 0;
973 * Adjust memory allocation if packet is too big.
975 if (ssh
->pktin
.maxlen
< st
->packetlen
+ st
->maclen
) {
976 ssh
->pktin
.maxlen
= st
->packetlen
+ st
->maclen
;
977 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
,
978 ssh
->pktin
.maxlen
+ APIEXTRA
);
982 * Read and decrypt the remainder of the packet.
984 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
;
986 while ((*datalen
) == 0)
987 crReturn(st
->packetlen
+ st
->maclen
- st
->i
);
988 ssh
->pktin
.data
[st
->i
] = *(*data
)++;
991 /* Decrypt everything _except_ the MAC. */
993 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
994 ssh
->pktin
.data
+ st
->cipherblk
,
995 st
->packetlen
- st
->cipherblk
);
1001 && !ssh
->scmac
->verify(ssh
->sc_mac_ctx
, ssh
->pktin
.data
, st
->len
+ 4,
1002 st
->incoming_sequence
)) {
1003 bombout((ssh
,"Incorrect MAC received on packet"));
1006 st
->incoming_sequence
++; /* whether or not we MACed */
1009 * Decompress packet payload.
1012 unsigned char *newpayload
;
1015 ssh
->sccomp
->decompress(ssh
->sc_comp_ctx
,
1016 ssh
->pktin
.data
+ 5, ssh
->pktin
.length
- 5,
1017 &newpayload
, &newlen
)) {
1018 if (ssh
->pktin
.maxlen
< newlen
+ 5) {
1019 ssh
->pktin
.maxlen
= newlen
+ 5;
1020 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
,
1021 ssh
->pktin
.maxlen
+ APIEXTRA
);
1023 ssh
->pktin
.length
= 5 + newlen
;
1024 memcpy(ssh
->pktin
.data
+ 5, newpayload
, newlen
);
1029 ssh
->pktin
.savedpos
= 6;
1030 ssh
->pktin
.type
= ssh
->pktin
.data
[5];
1033 log_packet(ssh
->logctx
, PKT_INCOMING
, ssh
->pktin
.type
,
1034 ssh2_pkt_type(ssh
->pkt_ctx
, ssh
->pktin
.type
),
1035 ssh
->pktin
.data
+6, ssh
->pktin
.length
-6);
1037 switch (ssh
->pktin
.type
) {
1039 * These packets we must handle instantly.
1041 case SSH2_MSG_DISCONNECT
:
1043 /* log reason code in disconnect message */
1046 int reason
= GET_32BIT(ssh
->pktin
.data
+ 6);
1047 unsigned msglen
= GET_32BIT(ssh
->pktin
.data
+ 10);
1049 if (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) {
1050 buf
= dupprintf("Received disconnect message (%s)",
1051 ssh2_disconnect_reasons
[reason
]);
1053 buf
= dupprintf("Received disconnect message (unknown"
1054 " type %d)", reason
);
1058 buf
= dupprintf("Disconnection message text: %n%.*s",
1059 &nowlen
, msglen
, ssh
->pktin
.data
+ 14);
1061 bombout((ssh
,"Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1063 (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) ?
1064 ssh2_disconnect_reasons
[reason
] : "unknown",
1070 case SSH2_MSG_IGNORE
:
1072 case SSH2_MSG_DEBUG
:
1074 /* log the debug message */
1076 /* int display = ssh->pktin.body[6]; */
1077 int stringlen
= GET_32BIT(ssh
->pktin
.data
+7);
1079 strcpy(buf
, "Remote debug message: ");
1080 prefix
= strlen(buf
);
1081 if (stringlen
> (int)(sizeof(buf
)-prefix
-1))
1082 stringlen
= sizeof(buf
)-prefix
-1;
1083 memcpy(buf
+ prefix
, ssh
->pktin
.data
+ 11, stringlen
);
1084 buf
[prefix
+ stringlen
] = '\0';
1087 goto next_packet
; /* FIXME: print the debug message */
1090 * These packets we need do nothing about here.
1092 case SSH2_MSG_UNIMPLEMENTED
:
1093 case SSH2_MSG_SERVICE_REQUEST
:
1094 case SSH2_MSG_SERVICE_ACCEPT
:
1095 case SSH2_MSG_KEXINIT
:
1096 case SSH2_MSG_NEWKEYS
:
1097 case SSH2_MSG_KEXDH_INIT
:
1098 case SSH2_MSG_KEXDH_REPLY
:
1099 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1100 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1101 case SSH2_MSG_KEX_DH_GEX_INIT
:
1102 case SSH2_MSG_KEX_DH_GEX_REPLY
:
1103 case SSH2_MSG_USERAUTH_REQUEST
:
1104 case SSH2_MSG_USERAUTH_FAILURE
:
1105 case SSH2_MSG_USERAUTH_SUCCESS
:
1106 case SSH2_MSG_USERAUTH_BANNER
:
1107 case SSH2_MSG_USERAUTH_PK_OK
:
1108 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1109 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1110 case SSH2_MSG_USERAUTH_INFO_RESPONSE
:
1111 case SSH2_MSG_GLOBAL_REQUEST
:
1112 case SSH2_MSG_REQUEST_SUCCESS
:
1113 case SSH2_MSG_REQUEST_FAILURE
:
1114 case SSH2_MSG_CHANNEL_OPEN
:
1115 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
:
1116 case SSH2_MSG_CHANNEL_OPEN_FAILURE
:
1117 case SSH2_MSG_CHANNEL_WINDOW_ADJUST
:
1118 case SSH2_MSG_CHANNEL_DATA
:
1119 case SSH2_MSG_CHANNEL_EXTENDED_DATA
:
1120 case SSH2_MSG_CHANNEL_EOF
:
1121 case SSH2_MSG_CHANNEL_CLOSE
:
1122 case SSH2_MSG_CHANNEL_REQUEST
:
1123 case SSH2_MSG_CHANNEL_SUCCESS
:
1124 case SSH2_MSG_CHANNEL_FAILURE
:
1128 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1131 ssh2_pkt_init(ssh
, SSH2_MSG_UNIMPLEMENTED
);
1132 ssh2_pkt_adduint32(ssh
, st
->incoming_sequence
- 1);
1140 static void ssh1_pktout_size(Ssh ssh
, int len
)
1144 len
+= 5; /* type and CRC */
1145 pad
= 8 - (len
% 8);
1148 ssh
->pktout
.length
= len
- 5;
1149 if (ssh
->pktout
.maxlen
< biglen
) {
1150 ssh
->pktout
.maxlen
= biglen
;
1152 /* Allocate enough buffer space for extra block
1153 * for MS CryptEncrypt() */
1154 ssh
->pktout
.data
= srealloc(ssh
->pktout
.data
, biglen
+ 12);
1156 ssh
->pktout
.data
= srealloc(ssh
->pktout
.data
, biglen
+ 4);
1159 ssh
->pktout
.body
= ssh
->pktout
.data
+ 4 + pad
+ 1;
1162 static void s_wrpkt_start(Ssh ssh
, int type
, int len
)
1164 ssh1_pktout_size(ssh
, len
);
1165 ssh
->pktout
.type
= type
;
1168 static int s_wrpkt_prepare(Ssh ssh
)
1170 int pad
, len
, biglen
, i
;
1173 ssh
->pktout
.body
[-1] = ssh
->pktout
.type
;
1176 log_packet(ssh
->logctx
, PKT_OUTGOING
, ssh
->pktout
.type
,
1177 ssh1_pkt_type(ssh
->pktout
.type
),
1178 ssh
->pktout
.body
, ssh
->pktout
.length
);
1180 if (ssh
->v1_compressing
) {
1181 unsigned char *compblk
;
1183 zlib_compress_block(ssh
->cs_comp_ctx
,
1184 ssh
->pktout
.body
- 1, ssh
->pktout
.length
+ 1,
1185 &compblk
, &complen
);
1186 ssh1_pktout_size(ssh
, complen
- 1);
1187 memcpy(ssh
->pktout
.body
- 1, compblk
, complen
);
1191 len
= ssh
->pktout
.length
+ 5; /* type and CRC */
1192 pad
= 8 - (len
% 8);
1195 for (i
= 0; i
< pad
; i
++)
1196 ssh
->pktout
.data
[i
+ 4] = random_byte();
1197 crc
= crc32(ssh
->pktout
.data
+ 4, biglen
- 4);
1198 PUT_32BIT(ssh
->pktout
.data
+ biglen
, crc
);
1199 PUT_32BIT(ssh
->pktout
.data
, len
);
1202 ssh
->cipher
->encrypt(ssh
->v1_cipher_ctx
, ssh
->pktout
.data
+ 4, biglen
);
1207 static void s_wrpkt(Ssh ssh
)
1210 len
= s_wrpkt_prepare(ssh
);
1211 backlog
= sk_write(ssh
->s
, (char *)ssh
->pktout
.data
, len
);
1212 if (backlog
> SSH_MAX_BACKLOG
)
1213 ssh_throttle_all(ssh
, 1, backlog
);
1216 static void s_wrpkt_defer(Ssh ssh
)
1219 len
= s_wrpkt_prepare(ssh
);
1220 if (ssh
->deferred_len
+ len
> ssh
->deferred_size
) {
1221 ssh
->deferred_size
= ssh
->deferred_len
+ len
+ 128;
1222 ssh
->deferred_send_data
= srealloc(ssh
->deferred_send_data
,
1223 ssh
->deferred_size
);
1225 memcpy(ssh
->deferred_send_data
+ ssh
->deferred_len
, ssh
->pktout
.data
, len
);
1226 ssh
->deferred_len
+= len
;
1230 * Construct a packet with the specified contents.
1232 static void construct_packet(Ssh ssh
, int pkttype
, va_list ap1
, va_list ap2
)
1234 unsigned char *p
, *argp
, argchar
;
1235 unsigned long argint
;
1236 int pktlen
, argtype
, arglen
;
1240 while ((argtype
= va_arg(ap1
, int)) != PKT_END
) {
1243 (void) va_arg(ap1
, int);
1247 (void) va_arg(ap1
, int);
1251 (void) va_arg(ap1
, unsigned char *);
1252 arglen
= va_arg(ap1
, int);
1256 argp
= va_arg(ap1
, unsigned char *);
1257 arglen
= strlen((char *)argp
);
1258 pktlen
+= 4 + arglen
;
1261 bn
= va_arg(ap1
, Bignum
);
1262 pktlen
+= ssh1_bignum_length(bn
);
1269 s_wrpkt_start(ssh
, pkttype
, pktlen
);
1270 p
= ssh
->pktout
.body
;
1272 while ((argtype
= va_arg(ap2
, int)) != PKT_END
) {
1275 argint
= va_arg(ap2
, int);
1276 PUT_32BIT(p
, argint
);
1280 argchar
= (unsigned char) va_arg(ap2
, int);
1285 argp
= va_arg(ap2
, unsigned char *);
1286 arglen
= va_arg(ap2
, int);
1287 memcpy(p
, argp
, arglen
);
1291 argp
= va_arg(ap2
, unsigned char *);
1292 arglen
= strlen((char *)argp
);
1293 PUT_32BIT(p
, arglen
);
1294 memcpy(p
+ 4, argp
, arglen
);
1298 bn
= va_arg(ap2
, Bignum
);
1299 p
+= ssh1_write_bignum(p
, bn
);
1305 static void send_packet(Ssh ssh
, int pkttype
, ...)
1308 va_start(ap1
, pkttype
);
1309 va_start(ap2
, pkttype
);
1310 construct_packet(ssh
, pkttype
, ap1
, ap2
);
1314 static void defer_packet(Ssh ssh
, int pkttype
, ...)
1317 va_start(ap1
, pkttype
);
1318 va_start(ap2
, pkttype
);
1319 construct_packet(ssh
, pkttype
, ap1
, ap2
);
1323 static int ssh_versioncmp(char *a
, char *b
)
1326 unsigned long av
, bv
;
1328 av
= strtoul(a
, &ae
, 10);
1329 bv
= strtoul(b
, &be
, 10);
1331 return (av
< bv ?
-1 : +1);
1336 av
= strtoul(ae
, &ae
, 10);
1337 bv
= strtoul(be
, &be
, 10);
1339 return (av
< bv ?
-1 : +1);
1344 * Utility routines for putting an SSH-protocol `string' and
1345 * `uint32' into a SHA state.
1348 static void sha_string(SHA_State
* s
, void *str
, int len
)
1350 unsigned char lenblk
[4];
1351 PUT_32BIT(lenblk
, len
);
1352 SHA_Bytes(s
, lenblk
, 4);
1353 SHA_Bytes(s
, str
, len
);
1356 static void sha_uint32(SHA_State
* s
, unsigned i
)
1358 unsigned char intblk
[4];
1359 PUT_32BIT(intblk
, i
);
1360 SHA_Bytes(s
, intblk
, 4);
1364 * SSH2 packet construction functions.
1366 static void ssh2_pkt_ensure(Ssh ssh
, int length
)
1368 if (ssh
->pktout
.maxlen
< length
) {
1369 ssh
->pktout
.maxlen
= length
+ 256;
1370 ssh
->pktout
.data
= srealloc(ssh
->pktout
.data
,
1371 ssh
->pktout
.maxlen
+ APIEXTRA
);
1372 if (!ssh
->pktout
.data
)
1373 fatalbox("Out of memory");
1376 static void ssh2_pkt_adddata(Ssh ssh
, void *data
, int len
)
1378 ssh
->pktout
.length
+= len
;
1379 ssh2_pkt_ensure(ssh
, ssh
->pktout
.length
);
1380 memcpy(ssh
->pktout
.data
+ ssh
->pktout
.length
- len
, data
, len
);
1382 static void ssh2_pkt_addbyte(Ssh ssh
, unsigned char byte
)
1384 ssh2_pkt_adddata(ssh
, &byte
, 1);
1386 static void ssh2_pkt_init(Ssh ssh
, int pkt_type
)
1388 ssh
->pktout
.length
= 5;
1389 ssh2_pkt_addbyte(ssh
, (unsigned char) pkt_type
);
1391 static void ssh2_pkt_addbool(Ssh ssh
, unsigned char value
)
1393 ssh2_pkt_adddata(ssh
, &value
, 1);
1395 static void ssh2_pkt_adduint32(Ssh ssh
, unsigned long value
)
1398 PUT_32BIT(x
, value
);
1399 ssh2_pkt_adddata(ssh
, x
, 4);
1401 static void ssh2_pkt_addstring_start(Ssh ssh
)
1403 ssh2_pkt_adduint32(ssh
, 0);
1404 ssh
->pktout
.savedpos
= ssh
->pktout
.length
;
1406 static void ssh2_pkt_addstring_str(Ssh ssh
, char *data
)
1408 ssh2_pkt_adddata(ssh
, data
, strlen(data
));
1409 PUT_32BIT(ssh
->pktout
.data
+ ssh
->pktout
.savedpos
- 4,
1410 ssh
->pktout
.length
- ssh
->pktout
.savedpos
);
1412 static void ssh2_pkt_addstring_data(Ssh ssh
, char *data
, int len
)
1414 ssh2_pkt_adddata(ssh
, data
, len
);
1415 PUT_32BIT(ssh
->pktout
.data
+ ssh
->pktout
.savedpos
- 4,
1416 ssh
->pktout
.length
- ssh
->pktout
.savedpos
);
1418 static void ssh2_pkt_addstring(Ssh ssh
, char *data
)
1420 ssh2_pkt_addstring_start(ssh
);
1421 ssh2_pkt_addstring_str(ssh
, data
);
1423 static unsigned char *ssh2_mpint_fmt(Bignum b
, int *len
)
1426 int i
, n
= (bignum_bitcount(b
) + 7) / 8;
1429 fatalbox("out of memory");
1431 for (i
= 1; i
<= n
; i
++)
1432 p
[i
] = bignum_byte(b
, n
- i
);
1434 while (i
<= n
&& p
[i
] == 0 && (p
[i
+ 1] & 0x80) == 0)
1436 memmove(p
, p
+ i
, n
+ 1 - i
);
1440 static void ssh2_pkt_addmp(Ssh ssh
, Bignum b
)
1444 p
= ssh2_mpint_fmt(b
, &len
);
1445 ssh2_pkt_addstring_start(ssh
);
1446 ssh2_pkt_addstring_data(ssh
, (char *)p
, len
);
1451 * Construct an SSH2 final-form packet: compress it, encrypt it,
1452 * put the MAC on it. Final packet, ready to be sent, is stored in
1453 * ssh->pktout.data. Total length is returned.
1455 static int ssh2_pkt_construct(Ssh ssh
)
1457 int cipherblk
, maclen
, padding
, i
;
1460 log_packet(ssh
->logctx
, PKT_OUTGOING
, ssh
->pktout
.data
[5],
1461 ssh2_pkt_type(ssh
->pkt_ctx
, ssh
->pktout
.data
[5]),
1462 ssh
->pktout
.data
+ 6, ssh
->pktout
.length
- 6);
1465 * Compress packet payload.
1468 unsigned char *newpayload
;
1471 ssh
->cscomp
->compress(ssh
->cs_comp_ctx
, ssh
->pktout
.data
+ 5,
1472 ssh
->pktout
.length
- 5,
1473 &newpayload
, &newlen
)) {
1474 ssh
->pktout
.length
= 5;
1475 ssh2_pkt_adddata(ssh
, newpayload
, newlen
);
1481 * Add padding. At least four bytes, and must also bring total
1482 * length (minus MAC) up to a multiple of the block size.
1484 cipherblk
= ssh
->cscipher ? ssh
->cscipher
->blksize
: 8; /* block size */
1485 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
1488 (cipherblk
- (ssh
->pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
1489 maclen
= ssh
->csmac ? ssh
->csmac
->len
: 0;
1490 ssh2_pkt_ensure(ssh
, ssh
->pktout
.length
+ padding
+ maclen
);
1491 ssh
->pktout
.data
[4] = padding
;
1492 for (i
= 0; i
< padding
; i
++)
1493 ssh
->pktout
.data
[ssh
->pktout
.length
+ i
] = random_byte();
1494 PUT_32BIT(ssh
->pktout
.data
, ssh
->pktout
.length
+ padding
- 4);
1496 ssh
->csmac
->generate(ssh
->cs_mac_ctx
, ssh
->pktout
.data
,
1497 ssh
->pktout
.length
+ padding
,
1498 ssh
->v2_outgoing_sequence
);
1499 ssh
->v2_outgoing_sequence
++; /* whether or not we MACed */
1502 ssh
->cscipher
->encrypt(ssh
->cs_cipher_ctx
,
1503 ssh
->pktout
.data
, ssh
->pktout
.length
+ padding
);
1505 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1506 return ssh
->pktout
.length
+ padding
+ maclen
;
1510 * Construct and send an SSH2 packet immediately.
1512 static void ssh2_pkt_send(Ssh ssh
)
1516 len
= ssh2_pkt_construct(ssh
);
1517 backlog
= sk_write(ssh
->s
, (char *)ssh
->pktout
.data
, len
);
1518 if (backlog
> SSH_MAX_BACKLOG
)
1519 ssh_throttle_all(ssh
, 1, backlog
);
1523 * Construct an SSH2 packet and add it to a deferred data block.
1524 * Useful for sending multiple packets in a single sk_write() call,
1525 * to prevent a traffic-analysing listener from being able to work
1526 * out the length of any particular packet (such as the password
1529 * Note that because SSH2 sequence-numbers its packets, this can
1530 * NOT be used as an m4-style `defer' allowing packets to be
1531 * constructed in one order and sent in another.
1533 static void ssh2_pkt_defer(Ssh ssh
)
1535 int len
= ssh2_pkt_construct(ssh
);
1536 if (ssh
->deferred_len
+ len
> ssh
->deferred_size
) {
1537 ssh
->deferred_size
= ssh
->deferred_len
+ len
+ 128;
1538 ssh
->deferred_send_data
= srealloc(ssh
->deferred_send_data
,
1539 ssh
->deferred_size
);
1541 memcpy(ssh
->deferred_send_data
+ ssh
->deferred_len
, ssh
->pktout
.data
, len
);
1542 ssh
->deferred_len
+= len
;
1546 * Send the whole deferred data block constructed by
1547 * ssh2_pkt_defer() or SSH1's defer_packet().
1549 static void ssh_pkt_defersend(Ssh ssh
)
1552 backlog
= sk_write(ssh
->s
, (char *)ssh
->deferred_send_data
,
1554 ssh
->deferred_len
= ssh
->deferred_size
= 0;
1555 sfree(ssh
->deferred_send_data
);
1556 ssh
->deferred_send_data
= NULL
;
1557 if (backlog
> SSH_MAX_BACKLOG
)
1558 ssh_throttle_all(ssh
, 1, backlog
);
1562 void bndebug(char *string
, Bignum b
)
1566 p
= ssh2_mpint_fmt(b
, &len
);
1567 debug(("%s", string
));
1568 for (i
= 0; i
< len
; i
++)
1569 debug((" %02x", p
[i
]));
1575 static void sha_mpint(SHA_State
* s
, Bignum b
)
1579 p
= ssh2_mpint_fmt(b
, &len
);
1580 sha_string(s
, p
, len
);
1585 * SSH2 packet decode functions.
1587 static unsigned long ssh2_pkt_getuint32(Ssh ssh
)
1589 unsigned long value
;
1590 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< 4)
1591 return 0; /* arrgh, no way to decline (FIXME?) */
1592 value
= GET_32BIT(ssh
->pktin
.data
+ ssh
->pktin
.savedpos
);
1593 ssh
->pktin
.savedpos
+= 4;
1596 static int ssh2_pkt_getbool(Ssh ssh
)
1598 unsigned long value
;
1599 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< 1)
1600 return 0; /* arrgh, no way to decline (FIXME?) */
1601 value
= ssh
->pktin
.data
[ssh
->pktin
.savedpos
] != 0;
1602 ssh
->pktin
.savedpos
++;
1605 static void ssh2_pkt_getstring(Ssh ssh
, char **p
, int *length
)
1610 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< 4)
1612 len
= GET_32BIT(ssh
->pktin
.data
+ ssh
->pktin
.savedpos
);
1616 ssh
->pktin
.savedpos
+= 4;
1617 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< *length
)
1619 *p
= (char *)(ssh
->pktin
.data
+ ssh
->pktin
.savedpos
);
1620 ssh
->pktin
.savedpos
+= *length
;
1622 static Bignum
ssh2_pkt_getmp(Ssh ssh
)
1628 ssh2_pkt_getstring(ssh
, &p
, &length
);
1632 bombout((ssh
,"internal error: Can't handle negative mpints"));
1635 b
= bignum_from_bytes((unsigned char *)p
, length
);
1640 * Helper function to add an SSH2 signature blob to a packet.
1641 * Expects to be shown the public key blob as well as the signature
1642 * blob. Normally works just like ssh2_pkt_addstring, but will
1643 * fiddle with the signature packet if necessary for
1644 * BUG_SSH2_RSA_PADDING.
1646 static void ssh2_add_sigblob(Ssh ssh
, void *pkblob_v
, int pkblob_len
,
1647 void *sigblob_v
, int sigblob_len
)
1649 unsigned char *pkblob
= (unsigned char *)pkblob_v
;
1650 unsigned char *sigblob
= (unsigned char *)sigblob_v
;
1652 /* dmemdump(pkblob, pkblob_len); */
1653 /* dmemdump(sigblob, sigblob_len); */
1656 * See if this is in fact an ssh-rsa signature and a buggy
1657 * server; otherwise we can just do this the easy way.
1659 if ((ssh
->remote_bugs
& BUG_SSH2_RSA_PADDING
) &&
1660 (GET_32BIT(pkblob
) == 7 && !memcmp(pkblob
+4, "ssh-rsa", 7))) {
1661 int pos
, len
, siglen
;
1664 * Find the byte length of the modulus.
1667 pos
= 4+7; /* skip over "ssh-rsa" */
1668 pos
+= 4 + GET_32BIT(pkblob
+pos
); /* skip over exponent */
1669 len
= GET_32BIT(pkblob
+pos
); /* find length of modulus */
1670 pos
+= 4; /* find modulus itself */
1671 while (len
> 0 && pkblob
[pos
] == 0)
1673 /* debug(("modulus length is %d\n", len)); */
1676 * Now find the signature integer.
1678 pos
= 4+7; /* skip over "ssh-rsa" */
1679 siglen
= GET_32BIT(sigblob
+pos
);
1680 /* debug(("signature length is %d\n", siglen)); */
1682 if (len
!= siglen
) {
1683 unsigned char newlen
[4];
1684 ssh2_pkt_addstring_start(ssh
);
1685 ssh2_pkt_addstring_data(ssh
, (char *)sigblob
, pos
);
1686 /* dmemdump(sigblob, pos); */
1687 pos
+= 4; /* point to start of actual sig */
1688 PUT_32BIT(newlen
, len
);
1689 ssh2_pkt_addstring_data(ssh
, (char *)newlen
, 4);
1690 /* dmemdump(newlen, 4); */
1692 while (len
-- > siglen
) {
1693 ssh2_pkt_addstring_data(ssh
, (char *)newlen
, 1);
1694 /* dmemdump(newlen, 1); */
1696 ssh2_pkt_addstring_data(ssh
, (char *)(sigblob
+pos
), siglen
);
1697 /* dmemdump(sigblob+pos, siglen); */
1701 /* Otherwise fall through and do it the easy way. */
1704 ssh2_pkt_addstring_start(ssh
);
1705 ssh2_pkt_addstring_data(ssh
, (char *)sigblob
, sigblob_len
);
1709 * Examine the remote side's version string and compare it against
1710 * a list of known buggy implementations.
1712 static void ssh_detect_bugs(Ssh ssh
, char *vstring
)
1714 char *imp
; /* pointer to implementation part */
1716 imp
+= strcspn(imp
, "-");
1718 imp
+= strcspn(imp
, "-");
1721 ssh
->remote_bugs
= 0;
1723 if (ssh
->cfg
.sshbug_ignore1
== FORCE_ON
||
1724 (ssh
->cfg
.sshbug_ignore1
== AUTO
&&
1725 (!strcmp(imp
, "1.2.18") || !strcmp(imp
, "1.2.19") ||
1726 !strcmp(imp
, "1.2.20") || !strcmp(imp
, "1.2.21") ||
1727 !strcmp(imp
, "1.2.22") || !strcmp(imp
, "Cisco-1.25")))) {
1729 * These versions don't support SSH1_MSG_IGNORE, so we have
1730 * to use a different defence against password length
1733 ssh
->remote_bugs
|= BUG_CHOKES_ON_SSH1_IGNORE
;
1734 logevent("We believe remote version has SSH1 ignore bug");
1737 if (ssh
->cfg
.sshbug_plainpw1
== FORCE_ON
||
1738 (ssh
->cfg
.sshbug_plainpw1
== AUTO
&&
1739 (!strcmp(imp
, "Cisco-1.25")))) {
1741 * These versions need a plain password sent; they can't
1742 * handle having a null and a random length of data after
1745 ssh
->remote_bugs
|= BUG_NEEDS_SSH1_PLAIN_PASSWORD
;
1746 logevent("We believe remote version needs a plain SSH1 password");
1749 if (ssh
->cfg
.sshbug_rsa1
== FORCE_ON
||
1750 (ssh
->cfg
.sshbug_rsa1
== AUTO
&&
1751 (!strcmp(imp
, "Cisco-1.25")))) {
1753 * These versions apparently have no clue whatever about
1754 * RSA authentication and will panic and die if they see
1755 * an AUTH_RSA message.
1757 ssh
->remote_bugs
|= BUG_CHOKES_ON_RSA
;
1758 logevent("We believe remote version can't handle RSA authentication");
1761 if (ssh
->cfg
.sshbug_hmac2
== FORCE_ON
||
1762 (ssh
->cfg
.sshbug_hmac2
== AUTO
&&
1763 (wc_match("2.1.0*", imp
) || wc_match("2.0.*", imp
) ||
1764 wc_match("2.2.0*", imp
) || wc_match("2.3.0*", imp
) ||
1765 wc_match("2.1 *", imp
)))) {
1767 * These versions have the HMAC bug.
1769 ssh
->remote_bugs
|= BUG_SSH2_HMAC
;
1770 logevent("We believe remote version has SSH2 HMAC bug");
1773 if (ssh
->cfg
.sshbug_derivekey2
== FORCE_ON
||
1774 (ssh
->cfg
.sshbug_derivekey2
== AUTO
&&
1775 (wc_match("2.0.0*", imp
) || wc_match("2.0.1[01]*", imp
) ))) {
1777 * These versions have the key-derivation bug (failing to
1778 * include the literal shared secret in the hashes that
1779 * generate the keys).
1781 ssh
->remote_bugs
|= BUG_SSH2_DERIVEKEY
;
1782 logevent("We believe remote version has SSH2 key-derivation bug");
1785 if (ssh
->cfg
.sshbug_rsapad2
== FORCE_ON
||
1786 (ssh
->cfg
.sshbug_rsapad2
== AUTO
&&
1787 (wc_match("OpenSSH_2.[5-9]*", imp
) ||
1788 wc_match("OpenSSH_3.[0-2]*", imp
)))) {
1790 * These versions have the SSH2 RSA padding bug.
1792 ssh
->remote_bugs
|= BUG_SSH2_RSA_PADDING
;
1793 logevent("We believe remote version has SSH2 RSA padding bug");
1796 if (ssh
->cfg
.sshbug_pksessid2
== FORCE_ON
||
1797 (ssh
->cfg
.sshbug_pksessid2
== AUTO
&&
1798 wc_match("OpenSSH_2.[0-2]*", imp
))) {
1800 * These versions have the SSH2 session-ID bug in
1801 * public-key authentication.
1803 ssh
->remote_bugs
|= BUG_SSH2_PK_SESSIONID
;
1804 logevent("We believe remote version has SSH2 public-key-session-ID bug");
1807 if (ssh
->cfg
.sshbug_dhgex2
== FORCE_ON
) {
1809 * User specified the SSH2 DH GEX bug.
1811 ssh
->remote_bugs
|= BUG_SSH2_DH_GEX
;
1812 logevent("We believe remote version has SSH2 DH group exchange bug");
1816 static int do_ssh_init(Ssh ssh
, unsigned char c
)
1818 struct do_ssh_init_state
{
1826 crState(do_ssh_init_state
);
1828 crBegin(ssh
->do_ssh_init_crstate
);
1830 /* Search for the string "SSH-" in the input. */
1833 static const int transS
[] = { 1, 2, 2, 1 };
1834 static const int transH
[] = { 0, 0, 3, 0 };
1835 static const int transminus
[] = { 0, 0, 0, -1 };
1837 s
->i
= transS
[s
->i
];
1839 s
->i
= transH
[s
->i
];
1841 s
->i
= transminus
[s
->i
];
1846 crReturn(1); /* get another character */
1850 s
->vstring
= smalloc(s
->vstrsize
);
1851 strcpy(s
->vstring
, "SSH-");
1855 crReturn(1); /* get another char */
1856 if (s
->vslen
>= s
->vstrsize
- 1) {
1858 s
->vstring
= srealloc(s
->vstring
, s
->vstrsize
);
1860 s
->vstring
[s
->vslen
++] = c
;
1863 s
->version
[s
->i
] = '\0';
1865 } else if (s
->i
< sizeof(s
->version
) - 1)
1866 s
->version
[s
->i
++] = c
;
1867 } else if (c
== '\012')
1871 ssh
->agentfwd_enabled
= FALSE
;
1872 ssh
->rdpkt2_state
.incoming_sequence
= 0;
1874 s
->vstring
[s
->vslen
] = 0;
1875 s
->vstring
[strcspn(s
->vstring
, "\r\n")] = '\0';/* remove EOL chars */
1878 vlog
= smalloc(20 + s
->vslen
);
1879 sprintf(vlog
, "Server version: %s", s
->vstring
);
1883 ssh_detect_bugs(ssh
, s
->vstring
);
1886 * Decide which SSH protocol version to support.
1889 /* Anything strictly below "2.0" means protocol 1 is supported. */
1890 s
->proto1
= ssh_versioncmp(s
->version
, "2.0") < 0;
1891 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
1892 s
->proto2
= ssh_versioncmp(s
->version
, "1.99") >= 0;
1894 if (ssh
->cfg
.sshprot
== 0 && !s
->proto1
) {
1895 bombout((ssh
,"SSH protocol version 1 required by user but not provided by server"));
1898 if (ssh
->cfg
.sshprot
== 3 && !s
->proto2
) {
1899 bombout((ssh
,"SSH protocol version 2 required by user but not provided by server"));
1903 if (s
->proto2
&& (ssh
->cfg
.sshprot
>= 2 || !s
->proto1
)) {
1907 char verstring
[80], vlog
[100];
1908 sprintf(verstring
, "SSH-2.0-%s", sshver
);
1909 SHA_Init(&ssh
->exhashbase
);
1911 * Hash our version string and their version string.
1913 sha_string(&ssh
->exhashbase
, verstring
, strlen(verstring
));
1914 sha_string(&ssh
->exhashbase
, s
->vstring
, strcspn(s
->vstring
, "\r\n"));
1915 sprintf(vlog
, "We claim version: %s", verstring
);
1917 strcat(verstring
, "\012");
1918 logevent("Using SSH protocol version 2");
1919 sk_write(ssh
->s
, verstring
, strlen(verstring
));
1920 ssh
->protocol
= ssh2_protocol
;
1922 ssh
->s_rdpkt
= ssh2_rdpkt
;
1927 char verstring
[80], vlog
[100];
1928 sprintf(verstring
, "SSH-%s-%s",
1929 (ssh_versioncmp(s
->version
, "1.5") <= 0 ? s
->version
: "1.5"),
1931 sprintf(vlog
, "We claim version: %s", verstring
);
1933 strcat(verstring
, "\012");
1935 logevent("Using SSH protocol version 1");
1936 sk_write(ssh
->s
, verstring
, strlen(verstring
));
1937 ssh
->protocol
= ssh1_protocol
;
1939 ssh
->s_rdpkt
= ssh1_rdpkt
;
1941 ssh
->state
= SSH_STATE_BEFORE_SIZE
;
1948 static void ssh_gotdata(Ssh ssh
, unsigned char *data
, int datalen
)
1950 crBegin(ssh
->ssh_gotdata_crstate
);
1953 * To begin with, feed the characters one by one to the
1954 * protocol initialisation / selection function do_ssh_init().
1955 * When that returns 0, we're done with the initial greeting
1956 * exchange and can move on to packet discipline.
1959 int ret
; /* need not be kept across crReturn */
1961 crReturnV
; /* more data please */
1962 ret
= do_ssh_init(ssh
, *data
);
1970 * We emerge from that loop when the initial negotiation is
1971 * over and we have selected an s_rdpkt function. Now pass
1972 * everything to s_rdpkt, and then pass the resulting packets
1973 * to the proper protocol handler.
1978 while (datalen
> 0) {
1979 if (ssh
->s_rdpkt(ssh
, &data
, &datalen
) == 0) {
1980 if (ssh
->state
== SSH_STATE_CLOSED
) {
1983 ssh
->protocol(ssh
, NULL
, 0, 1);
1984 if (ssh
->state
== SSH_STATE_CLOSED
) {
1994 static int ssh_closing(Plug plug
, char *error_msg
, int error_code
,
1997 Ssh ssh
= (Ssh
) plug
;
1998 ssh
->state
= SSH_STATE_CLOSED
;
2004 /* A socket error has occurred. */
2005 logevent(error_msg
);
2006 connection_fatal(ssh
->frontend
, error_msg
);
2008 /* Otherwise, the remote side closed the connection normally. */
2013 static int ssh_receive(Plug plug
, int urgent
, char *data
, int len
)
2015 Ssh ssh
= (Ssh
) plug
;
2016 ssh_gotdata(ssh
, (unsigned char *)data
, len
);
2017 if (ssh
->state
== SSH_STATE_CLOSED
) {
2027 static void ssh_sent(Plug plug
, int bufsize
)
2029 Ssh ssh
= (Ssh
) plug
;
2031 * If the send backlog on the SSH socket itself clears, we
2032 * should unthrottle the whole world if it was throttled.
2034 if (bufsize
< SSH_MAX_BACKLOG
)
2035 ssh_throttle_all(ssh
, 0, bufsize
);
2039 * Connect to specified host and port.
2040 * Returns an error message, or NULL on success.
2041 * Also places the canonical host name into `realhost'. It must be
2042 * freed by the caller.
2044 static char *connect_to_host(Ssh ssh
, char *host
, int port
,
2045 char **realhost
, int nodelay
)
2047 static const struct plug_function_table fn_table
= {
2057 ssh
->savedhost
= smalloc(1 + strlen(host
));
2058 if (!ssh
->savedhost
)
2059 fatalbox("Out of memory");
2060 strcpy(ssh
->savedhost
, host
);
2063 port
= 22; /* default ssh port */
2064 ssh
->savedport
= port
;
2069 logeventf(ssh
, "Looking up host \"%s\"", host
);
2070 addr
= name_lookup(host
, port
, realhost
, &ssh
->cfg
);
2071 if ((err
= sk_addr_error(addr
)) != NULL
)
2079 sk_getaddr(addr
, addrbuf
, 100);
2080 logeventf(ssh
, "Connecting to %s port %d", addrbuf
, port
);
2082 ssh
->fn
= &fn_table
;
2083 ssh
->s
= new_connection(addr
, *realhost
, port
,
2084 0, 1, nodelay
, (Plug
) ssh
, &ssh
->cfg
);
2085 if ((err
= sk_socket_error(ssh
->s
)) != NULL
) {
2094 * Throttle or unthrottle the SSH connection.
2096 static void ssh1_throttle(Ssh ssh
, int adjust
)
2098 int old_count
= ssh
->v1_throttle_count
;
2099 ssh
->v1_throttle_count
+= adjust
;
2100 assert(ssh
->v1_throttle_count
>= 0);
2101 if (ssh
->v1_throttle_count
&& !old_count
) {
2102 sk_set_frozen(ssh
->s
, 1);
2103 } else if (!ssh
->v1_throttle_count
&& old_count
) {
2104 sk_set_frozen(ssh
->s
, 0);
2109 * Throttle or unthrottle _all_ local data streams (for when sends
2110 * on the SSH connection itself back up).
2112 static void ssh_throttle_all(Ssh ssh
, int enable
, int bufsize
)
2115 struct ssh_channel
*c
;
2117 if (enable
== ssh
->throttled_all
)
2119 ssh
->throttled_all
= enable
;
2120 ssh
->overall_bufsize
= bufsize
;
2123 for (i
= 0; NULL
!= (c
= index234(ssh
->channels
, i
)); i
++) {
2125 case CHAN_MAINSESSION
:
2127 * This is treated separately, outside the switch.
2131 x11_override_throttle(c
->u
.x11
.s
, enable
);
2134 /* Agent channels require no buffer management. */
2137 pfd_override_throttle(c
->u
.x11
.s
, enable
);
2144 * Username and password input, abstracted off into routines
2145 * reusable in several places - even between SSH1 and SSH2.
2148 /* Set up a username or password input loop on a given buffer. */
2149 static void setup_userpass_input(Ssh ssh
, char *buffer
, int buflen
, int echo
)
2151 ssh
->userpass_input_buffer
= buffer
;
2152 ssh
->userpass_input_buflen
= buflen
;
2153 ssh
->userpass_input_bufpos
= 0;
2154 ssh
->userpass_input_echo
= echo
;
2158 * Process some terminal data in the course of username/password
2159 * input. Returns >0 for success (line of input returned in
2160 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2161 * for inconclusive (keep waiting for more input please).
2163 static int process_userpass_input(Ssh ssh
, unsigned char *in
, int inlen
)
2168 switch (c
= *in
++) {
2171 ssh
->userpass_input_buffer
[ssh
->userpass_input_bufpos
] = 0;
2172 ssh
->userpass_input_buffer
[ssh
->userpass_input_buflen
-1] = 0;
2177 if (ssh
->userpass_input_bufpos
> 0) {
2178 if (ssh
->userpass_input_echo
)
2179 c_write_str(ssh
, "\b \b");
2180 ssh
->userpass_input_bufpos
--;
2185 while (ssh
->userpass_input_bufpos
> 0) {
2186 if (ssh
->userpass_input_echo
)
2187 c_write_str(ssh
, "\b \b");
2188 ssh
->userpass_input_bufpos
--;
2196 if (((c
>= ' ' && c
<= '~') ||
2197 ((unsigned char) c
>= 160))
2198 && ssh
->userpass_input_bufpos
< ssh
->userpass_input_buflen
-1) {
2199 ssh
->userpass_input_buffer
[ssh
->userpass_input_bufpos
++] = c
;
2200 if (ssh
->userpass_input_echo
)
2201 c_write(ssh
, &c
, 1);
2210 * Handle the key exchange and user authentication phases.
2212 static int do_ssh1_login(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
2215 unsigned char cookie
[8];
2216 struct RSAKey servkey
, hostkey
;
2217 struct MD5Context md5c
;
2218 struct do_ssh1_login_state
{
2220 unsigned char *rsabuf
, *keystr1
, *keystr2
;
2221 unsigned long supported_ciphers_mask
, supported_auths_mask
;
2222 int tried_publickey
, tried_agent
;
2223 int tis_auth_refused
, ccard_auth_refused
;
2224 unsigned char session_id
[16];
2227 void *publickey_blob
;
2228 int publickey_bloblen
;
2234 unsigned char request
[5], *response
, *p
;
2243 crState(do_ssh1_login_state
);
2245 crBegin(ssh
->do_ssh1_login_crstate
);
2250 if (ssh
->pktin
.type
!= SSH1_SMSG_PUBLIC_KEY
) {
2251 bombout((ssh
,"Public key packet not received"));
2255 logevent("Received public keys");
2257 memcpy(cookie
, ssh
->pktin
.body
, 8);
2259 i
= makekey(ssh
->pktin
.body
+ 8, &servkey
, &s
->keystr1
, 0);
2260 j
= makekey(ssh
->pktin
.body
+ 8 + i
, &hostkey
, &s
->keystr2
, 0);
2263 * Log the host key fingerprint.
2267 logevent("Host key fingerprint is:");
2268 strcpy(logmsg
, " ");
2269 hostkey
.comment
= NULL
;
2270 rsa_fingerprint(logmsg
+ strlen(logmsg
),
2271 sizeof(logmsg
) - strlen(logmsg
), &hostkey
);
2275 ssh
->v1_remote_protoflags
= GET_32BIT(ssh
->pktin
.body
+ 8 + i
+ j
);
2276 s
->supported_ciphers_mask
= GET_32BIT(ssh
->pktin
.body
+ 12 + i
+ j
);
2277 s
->supported_auths_mask
= GET_32BIT(ssh
->pktin
.body
+ 16 + i
+ j
);
2279 ssh
->v1_local_protoflags
=
2280 ssh
->v1_remote_protoflags
& SSH1_PROTOFLAGS_SUPPORTED
;
2281 ssh
->v1_local_protoflags
|= SSH1_PROTOFLAG_SCREEN_NUMBER
;
2284 MD5Update(&md5c
, s
->keystr2
, hostkey
.bytes
);
2285 MD5Update(&md5c
, s
->keystr1
, servkey
.bytes
);
2286 MD5Update(&md5c
, ssh
->pktin
.body
, 8);
2287 MD5Final(s
->session_id
, &md5c
);
2289 for (i
= 0; i
< 32; i
++)
2290 ssh
->session_key
[i
] = random_byte();
2292 s
->len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
2294 s
->rsabuf
= smalloc(s
->len
);
2296 fatalbox("Out of memory");
2299 * Verify the host key.
2303 * First format the key into a string.
2305 int len
= rsastr_len(&hostkey
);
2306 char fingerprint
[100];
2307 char *keystr
= smalloc(len
);
2309 fatalbox("Out of memory");
2310 rsastr_fmt(keystr
, &hostkey
);
2311 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
2312 verify_ssh_host_key(ssh
->frontend
,
2313 ssh
->savedhost
, ssh
->savedport
, "rsa", keystr
,
2318 for (i
= 0; i
< 32; i
++) {
2319 s
->rsabuf
[i
] = ssh
->session_key
[i
];
2321 s
->rsabuf
[i
] ^= s
->session_id
[i
];
2324 if (hostkey
.bytes
> servkey
.bytes
) {
2325 rsaencrypt(s
->rsabuf
, 32, &servkey
);
2326 rsaencrypt(s
->rsabuf
, servkey
.bytes
, &hostkey
);
2328 rsaencrypt(s
->rsabuf
, 32, &hostkey
);
2329 rsaencrypt(s
->rsabuf
, hostkey
.bytes
, &servkey
);
2332 logevent("Encrypted session key");
2335 int cipher_chosen
= 0, warn
= 0;
2336 char *cipher_string
= NULL
;
2338 for (i
= 0; !cipher_chosen
&& i
< CIPHER_MAX
; i
++) {
2339 int next_cipher
= ssh
->cfg
.ssh_cipherlist
[i
];
2340 if (next_cipher
== CIPHER_WARN
) {
2341 /* If/when we choose a cipher, warn about it */
2343 } else if (next_cipher
== CIPHER_AES
) {
2344 /* XXX Probably don't need to mention this. */
2345 logevent("AES not supported in SSH1, skipping");
2347 switch (next_cipher
) {
2348 case CIPHER_3DES
: s
->cipher_type
= SSH_CIPHER_3DES
;
2349 cipher_string
= "3DES"; break;
2350 case CIPHER_BLOWFISH
: s
->cipher_type
= SSH_CIPHER_BLOWFISH
;
2351 cipher_string
= "Blowfish"; break;
2352 case CIPHER_DES
: s
->cipher_type
= SSH_CIPHER_DES
;
2353 cipher_string
= "single-DES"; break;
2355 if (s
->supported_ciphers_mask
& (1 << s
->cipher_type
))
2359 if (!cipher_chosen
) {
2360 if ((s
->supported_ciphers_mask
& (1 << SSH_CIPHER_3DES
)) == 0)
2361 bombout((ssh
,"Server violates SSH 1 protocol by not "
2362 "supporting 3DES encryption"));
2364 /* shouldn't happen */
2365 bombout((ssh
,"No supported ciphers found"));
2369 /* Warn about chosen cipher if necessary. */
2371 askcipher(ssh
->frontend
, cipher_string
, 0);
2374 switch (s
->cipher_type
) {
2375 case SSH_CIPHER_3DES
:
2376 logevent("Using 3DES encryption");
2378 case SSH_CIPHER_DES
:
2379 logevent("Using single-DES encryption");
2381 case SSH_CIPHER_BLOWFISH
:
2382 logevent("Using Blowfish encryption");
2386 send_packet(ssh
, SSH1_CMSG_SESSION_KEY
,
2387 PKT_CHAR
, s
->cipher_type
,
2388 PKT_DATA
, cookie
, 8,
2389 PKT_CHAR
, (s
->len
* 8) >> 8, PKT_CHAR
, (s
->len
* 8) & 0xFF,
2390 PKT_DATA
, s
->rsabuf
, s
->len
,
2391 PKT_INT
, ssh
->v1_local_protoflags
, PKT_END
);
2393 logevent("Trying to enable encryption...");
2397 ssh
->cipher
= (s
->cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
2398 s
->cipher_type
== SSH_CIPHER_DES ?
&ssh_des
:
2400 ssh
->v1_cipher_ctx
= ssh
->cipher
->make_context();
2401 ssh
->cipher
->sesskey(ssh
->v1_cipher_ctx
, ssh
->session_key
);
2402 logeventf(ssh
, "Initialised %s encryption", ssh
->cipher
->text_name
);
2404 ssh
->crcda_ctx
= crcda_make_context();
2405 logevent("Installing CRC compensation attack detector");
2409 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2410 bombout((ssh
,"Encryption not successfully enabled"));
2414 logevent("Successfully started encryption");
2418 if ((flags
& FLAG_INTERACTIVE
) && !*ssh
->cfg
.username
) {
2419 if (ssh_get_line
&& !ssh_getline_pw_only
) {
2420 if (!ssh_get_line("login as: ",
2421 s
->username
, sizeof(s
->username
), FALSE
)) {
2423 * get_line failed to get a username.
2426 logevent("No username provided. Abandoning session.");
2427 ssh
->state
= SSH_STATE_CLOSED
;
2431 int ret
; /* need not be kept over crReturn */
2432 c_write_str(ssh
, "login as: ");
2435 setup_userpass_input(ssh
, s
->username
, sizeof(s
->username
), 1);
2437 crWaitUntil(!ispkt
);
2438 ret
= process_userpass_input(ssh
, in
, inlen
);
2442 c_write_str(ssh
, "\r\n");
2445 strncpy(s
->username
, ssh
->cfg
.username
, sizeof(s
->username
));
2446 s
->username
[sizeof(s
->username
)-1] = '\0';
2449 send_packet(ssh
, SSH1_CMSG_USER
, PKT_STR
, s
->username
, PKT_END
);
2451 char userlog
[22 + sizeof(s
->username
)];
2452 sprintf(userlog
, "Sent username \"%s\"", s
->username
);
2454 if (flags
& FLAG_INTERACTIVE
&&
2455 (!((flags
& FLAG_STDERR
) && (flags
& FLAG_VERBOSE
)))) {
2456 strcat(userlog
, "\r\n");
2457 c_write_str(ssh
, userlog
);
2464 if ((ssh
->remote_bugs
& BUG_CHOKES_ON_RSA
)) {
2465 /* We must not attempt PK auth. Pretend we've already tried it. */
2466 s
->tried_publickey
= s
->tried_agent
= 1;
2468 s
->tried_publickey
= s
->tried_agent
= 0;
2470 s
->tis_auth_refused
= s
->ccard_auth_refused
= 0;
2471 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
2472 if (!filename_is_null(ssh
->cfg
.keyfile
)) {
2473 if (!rsakey_pubblob(&ssh
->cfg
.keyfile
,
2474 &s
->publickey_blob
, &s
->publickey_bloblen
))
2475 s
->publickey_blob
= NULL
;
2477 s
->publickey_blob
= NULL
;
2479 while (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2480 s
->pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
2482 if (agent_exists() && !s
->tried_agent
) {
2484 * Attempt RSA authentication using Pageant.
2490 logevent("Pageant is running. Requesting keys.");
2492 /* Request the keys held by the agent. */
2493 PUT_32BIT(s
->request
, 1);
2494 s
->request
[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES
;
2495 agent_query(s
->request
, 5, &r
, &s
->responselen
);
2496 s
->response
= (unsigned char *) r
;
2497 if (s
->response
&& s
->responselen
>= 5 &&
2498 s
->response
[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER
) {
2499 s
->p
= s
->response
+ 5;
2500 s
->nkeys
= GET_32BIT(s
->p
);
2504 sprintf(buf
, "Pageant has %d SSH1 keys", s
->nkeys
);
2507 for (s
->keyi
= 0; s
->keyi
< s
->nkeys
; s
->keyi
++) {
2510 sprintf(buf
, "Trying Pageant key #%d", s
->keyi
);
2513 if (s
->publickey_blob
&&
2514 !memcmp(s
->p
, s
->publickey_blob
,
2515 s
->publickey_bloblen
)) {
2516 logevent("This key matches configured key file");
2517 s
->tried_publickey
= 1;
2520 s
->p
+= ssh1_read_bignum(s
->p
, &s
->key
.exponent
);
2521 s
->p
+= ssh1_read_bignum(s
->p
, &s
->key
.modulus
);
2522 s
->commentlen
= GET_32BIT(s
->p
);
2524 s
->commentp
= (char *)s
->p
;
2525 s
->p
+= s
->commentlen
;
2526 send_packet(ssh
, SSH1_CMSG_AUTH_RSA
,
2527 PKT_BIGNUM
, s
->key
.modulus
, PKT_END
);
2529 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2530 logevent("Key refused");
2533 logevent("Received RSA challenge");
2534 ssh1_read_bignum(ssh
->pktin
.body
, &s
->challenge
);
2536 char *agentreq
, *q
, *ret
;
2539 len
= 1 + 4; /* message type, bit count */
2540 len
+= ssh1_bignum_length(s
->key
.exponent
);
2541 len
+= ssh1_bignum_length(s
->key
.modulus
);
2542 len
+= ssh1_bignum_length(s
->challenge
);
2543 len
+= 16; /* session id */
2544 len
+= 4; /* response format */
2545 agentreq
= smalloc(4 + len
);
2546 PUT_32BIT(agentreq
, len
);
2548 *q
++ = SSH1_AGENTC_RSA_CHALLENGE
;
2549 PUT_32BIT(q
, bignum_bitcount(s
->key
.modulus
));
2551 q
+= ssh1_write_bignum(q
, s
->key
.exponent
);
2552 q
+= ssh1_write_bignum(q
, s
->key
.modulus
);
2553 q
+= ssh1_write_bignum(q
, s
->challenge
);
2554 memcpy(q
, s
->session_id
, 16);
2556 PUT_32BIT(q
, 1); /* response format */
2557 agent_query(agentreq
, len
+ 4, &vret
, &retlen
);
2561 if (ret
[4] == SSH1_AGENT_RSA_RESPONSE
) {
2562 logevent("Sending Pageant's response");
2563 send_packet(ssh
, SSH1_CMSG_AUTH_RSA_RESPONSE
,
2564 PKT_DATA
, ret
+ 5, 16,
2568 if (ssh
->pktin
.type
== SSH1_SMSG_SUCCESS
) {
2570 ("Pageant's response accepted");
2571 if (flags
& FLAG_VERBOSE
) {
2572 c_write_str(ssh
, "Authenticated using"
2574 c_write(ssh
, s
->commentp
,
2576 c_write_str(ssh
, "\" from agent\r\n");
2581 ("Pageant's response not accepted");
2584 ("Pageant failed to answer challenge");
2588 logevent("No reply received from Pageant");
2591 freebn(s
->key
.exponent
);
2592 freebn(s
->key
.modulus
);
2593 freebn(s
->challenge
);
2601 if (!filename_is_null(ssh
->cfg
.keyfile
) && !s
->tried_publickey
)
2602 s
->pwpkt_type
= SSH1_CMSG_AUTH_RSA
;
2604 if (ssh
->cfg
.try_tis_auth
&&
2605 (s
->supported_auths_mask
& (1 << SSH1_AUTH_TIS
)) &&
2606 !s
->tis_auth_refused
) {
2607 s
->pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
2608 logevent("Requested TIS authentication");
2609 send_packet(ssh
, SSH1_CMSG_AUTH_TIS
, PKT_END
);
2611 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
2612 logevent("TIS authentication declined");
2613 if (flags
& FLAG_INTERACTIVE
)
2614 c_write_str(ssh
, "TIS authentication refused.\r\n");
2615 s
->tis_auth_refused
= 1;
2618 int challengelen
= GET_32BIT(ssh
->pktin
.body
);
2619 logevent("Received TIS challenge");
2620 if (challengelen
> sizeof(s
->prompt
) - 1)
2621 challengelen
= sizeof(s
->prompt
) - 1;/* prevent overrun */
2622 memcpy(s
->prompt
, ssh
->pktin
.body
+ 4, challengelen
);
2623 /* Prompt heuristic comes from OpenSSH */
2624 strncpy(s
->prompt
+ challengelen
,
2625 memchr(s
->prompt
, '\n', challengelen
) ?
2626 "": "\r\nResponse: ",
2627 (sizeof s
->prompt
) - challengelen
);
2628 s
->prompt
[(sizeof s
->prompt
) - 1] = '\0';
2631 if (ssh
->cfg
.try_tis_auth
&&
2632 (s
->supported_auths_mask
& (1 << SSH1_AUTH_CCARD
)) &&
2633 !s
->ccard_auth_refused
) {
2634 s
->pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
2635 logevent("Requested CryptoCard authentication");
2636 send_packet(ssh
, SSH1_CMSG_AUTH_CCARD
, PKT_END
);
2638 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
2639 logevent("CryptoCard authentication declined");
2640 c_write_str(ssh
, "CryptoCard authentication refused.\r\n");
2641 s
->ccard_auth_refused
= 1;
2644 int challengelen
= GET_32BIT(ssh
->pktin
.body
);
2645 logevent("Received CryptoCard challenge");
2646 if (challengelen
> sizeof(s
->prompt
) - 1)
2647 challengelen
= sizeof(s
->prompt
) - 1;/* prevent overrun */
2648 memcpy(s
->prompt
, ssh
->pktin
.body
+ 4, challengelen
);
2649 strncpy(s
->prompt
+ challengelen
,
2650 memchr(s
->prompt
, '\n', challengelen
) ?
2651 "" : "\r\nResponse: ",
2652 sizeof(s
->prompt
) - challengelen
);
2653 s
->prompt
[sizeof(s
->prompt
) - 1] = '\0';
2656 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2657 sprintf(s
->prompt
, "%.90s@%.90s's password: ",
2658 s
->username
, ssh
->savedhost
);
2660 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2661 char *comment
= NULL
;
2664 if (flags
& FLAG_VERBOSE
)
2665 c_write_str(ssh
, "Trying public key authentication.\r\n");
2666 logeventf(ssh
, "Trying public key \"%s\"",
2667 filename_to_str(&ssh
->cfg
.keyfile
));
2668 type
= key_type(&ssh
->cfg
.keyfile
);
2669 if (type
!= SSH_KEYTYPE_SSH1
) {
2670 sprintf(msgbuf
, "Key is of wrong type (%s)",
2671 key_type_to_str(type
));
2673 c_write_str(ssh
, msgbuf
);
2674 c_write_str(ssh
, "\r\n");
2675 s
->tried_publickey
= 1;
2678 if (!rsakey_encrypted(&ssh
->cfg
.keyfile
, &comment
)) {
2679 if (flags
& FLAG_VERBOSE
)
2680 c_write_str(ssh
, "No passphrase required.\r\n");
2683 sprintf(s
->prompt
, "Passphrase for key \"%.100s\": ", comment
);
2688 * Show password prompt, having first obtained it via a TIS
2689 * or CryptoCard exchange if we're doing TIS or CryptoCard
2693 if (!ssh_get_line(s
->prompt
, s
->password
,
2694 sizeof(s
->password
), TRUE
)) {
2696 * get_line failed to get a password (for example
2697 * because one was supplied on the command line
2698 * which has already failed to work). Terminate.
2700 send_packet(ssh
, SSH1_MSG_DISCONNECT
,
2701 PKT_STR
, "No more passwords available to try",
2703 logevent("Unable to authenticate");
2704 connection_fatal(ssh
->frontend
, "Unable to authenticate");
2705 ssh
->state
= SSH_STATE_CLOSED
;
2709 /* Prompt may have come from server. We've munged it a bit, so
2710 * we know it to be zero-terminated at least once. */
2711 int ret
; /* need not be saved over crReturn */
2712 c_write_untrusted(ssh
, s
->prompt
, strlen(s
->prompt
));
2715 setup_userpass_input(ssh
, s
->password
, sizeof(s
->password
), 0);
2717 crWaitUntil(!ispkt
);
2718 ret
= process_userpass_input(ssh
, in
, inlen
);
2722 c_write_str(ssh
, "\r\n");
2726 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2728 * Try public key authentication with the specified
2731 s
->tried_publickey
= 1;
2734 int ret
= loadrsakey(&ssh
->cfg
.keyfile
, &s
->key
, s
->password
);
2736 c_write_str(ssh
, "Couldn't load private key from ");
2737 c_write_str(ssh
, filename_to_str(&ssh
->cfg
.keyfile
));
2738 c_write_str(ssh
, ".\r\n");
2739 continue; /* go and try password */
2742 c_write_str(ssh
, "Wrong passphrase.\r\n");
2743 s
->tried_publickey
= 0;
2744 continue; /* try again */
2749 * Send a public key attempt.
2751 send_packet(ssh
, SSH1_CMSG_AUTH_RSA
,
2752 PKT_BIGNUM
, s
->key
.modulus
, PKT_END
);
2755 if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2756 c_write_str(ssh
, "Server refused our public key.\r\n");
2757 continue; /* go and try password */
2759 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2760 bombout((ssh
,"Bizarre response to offer of public key"));
2766 unsigned char buffer
[32];
2767 Bignum challenge
, response
;
2769 ssh1_read_bignum(ssh
->pktin
.body
, &challenge
);
2770 response
= rsadecrypt(challenge
, &s
->key
);
2771 freebn(s
->key
.private_exponent
);/* burn the evidence */
2773 for (i
= 0; i
< 32; i
++) {
2774 buffer
[i
] = bignum_byte(response
, 31 - i
);
2778 MD5Update(&md5c
, buffer
, 32);
2779 MD5Update(&md5c
, s
->session_id
, 16);
2780 MD5Final(buffer
, &md5c
);
2782 send_packet(ssh
, SSH1_CMSG_AUTH_RSA_RESPONSE
,
2783 PKT_DATA
, buffer
, 16, PKT_END
);
2790 if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2791 if (flags
& FLAG_VERBOSE
)
2792 c_write_str(ssh
, "Failed to authenticate with"
2793 " our public key.\r\n");
2794 continue; /* go and try password */
2795 } else if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2796 bombout((ssh
,"Bizarre response to RSA authentication response"));
2800 break; /* we're through! */
2802 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2804 * Defence against traffic analysis: we send a
2805 * whole bunch of packets containing strings of
2806 * different lengths. One of these strings is the
2807 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2808 * The others are all random data in
2809 * SSH1_MSG_IGNORE packets. This way a passive
2810 * listener can't tell which is the password, and
2811 * hence can't deduce the password length.
2813 * Anybody with a password length greater than 16
2814 * bytes is going to have enough entropy in their
2815 * password that a listener won't find it _that_
2816 * much help to know how long it is. So what we'll
2819 * - if password length < 16, we send 15 packets
2820 * containing string lengths 1 through 15
2822 * - otherwise, we let N be the nearest multiple
2823 * of 8 below the password length, and send 8
2824 * packets containing string lengths N through
2825 * N+7. This won't obscure the order of
2826 * magnitude of the password length, but it will
2827 * introduce a bit of extra uncertainty.
2829 * A few servers (the old 1.2.18 through 1.2.22)
2830 * can't deal with SSH1_MSG_IGNORE. For these
2831 * servers, we need an alternative defence. We make
2832 * use of the fact that the password is interpreted
2833 * as a C string: so we can append a NUL, then some
2836 * One server (a Cisco one) can deal with neither
2837 * SSH1_MSG_IGNORE _nor_ a padded password string.
2838 * For this server we are left with no defences
2839 * against password length sniffing.
2841 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
)) {
2843 * The server can deal with SSH1_MSG_IGNORE, so
2844 * we can use the primary defence.
2846 int bottom
, top
, pwlen
, i
;
2849 pwlen
= strlen(s
->password
);
2851 bottom
= 0; /* zero length passwords are OK! :-) */
2854 bottom
= pwlen
& ~7;
2858 assert(pwlen
>= bottom
&& pwlen
<= top
);
2860 randomstr
= smalloc(top
+ 1);
2862 for (i
= bottom
; i
<= top
; i
++) {
2864 defer_packet(ssh
, s
->pwpkt_type
,
2865 PKT_STR
, s
->password
, PKT_END
);
2867 for (j
= 0; j
< i
; j
++) {
2869 randomstr
[j
] = random_byte();
2870 } while (randomstr
[j
] == '\0');
2872 randomstr
[i
] = '\0';
2873 defer_packet(ssh
, SSH1_MSG_IGNORE
,
2874 PKT_STR
, randomstr
, PKT_END
);
2877 logevent("Sending password with camouflage packets");
2878 ssh_pkt_defersend(ssh
);
2880 else if (!(ssh
->remote_bugs
& BUG_NEEDS_SSH1_PLAIN_PASSWORD
)) {
2882 * The server can't deal with SSH1_MSG_IGNORE
2883 * but can deal with padded passwords, so we
2884 * can use the secondary defence.
2890 len
= strlen(s
->password
);
2891 if (len
< sizeof(string
)) {
2893 strcpy(string
, s
->password
);
2894 len
++; /* cover the zero byte */
2895 while (len
< sizeof(string
)) {
2896 string
[len
++] = (char) random_byte();
2901 logevent("Sending length-padded password");
2902 send_packet(ssh
, s
->pwpkt_type
, PKT_INT
, len
,
2903 PKT_DATA
, ss
, len
, PKT_END
);
2906 * The server has _both_
2907 * BUG_CHOKES_ON_SSH1_IGNORE and
2908 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2909 * therefore nothing we can do.
2912 len
= strlen(s
->password
);
2913 logevent("Sending unpadded password");
2914 send_packet(ssh
, s
->pwpkt_type
, PKT_INT
, len
,
2915 PKT_DATA
, s
->password
, len
, PKT_END
);
2918 send_packet(ssh
, s
->pwpkt_type
, PKT_STR
, s
->password
, PKT_END
);
2921 logevent("Sent password");
2922 memset(s
->password
, 0, strlen(s
->password
));
2924 if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2925 if (flags
& FLAG_VERBOSE
)
2926 c_write_str(ssh
, "Access denied\r\n");
2927 logevent("Authentication refused");
2928 } else if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2929 bombout((ssh
,"Strange packet received, type %d", ssh
->pktin
.type
));
2934 logevent("Authentication successful");
2939 void sshfwd_close(struct ssh_channel
*c
)
2943 if (c
&& !c
->closes
) {
2945 * If the channel's remoteid is -1, we have sent
2946 * CHANNEL_OPEN for this channel, but it hasn't even been
2947 * acknowledged by the server. So we must set a close flag
2948 * on it now, and then when the server acks the channel
2949 * open, we can close it then.
2951 if (((int)c
->remoteid
) != -1) {
2952 if (ssh
->version
== 1) {
2953 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
2956 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_CLOSE
);
2957 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
2961 c
->closes
= 1; /* sent MSG_CLOSE */
2962 if (c
->type
== CHAN_X11
) {
2964 logevent("Forwarded X11 connection terminated");
2965 } else if (c
->type
== CHAN_SOCKDATA
||
2966 c
->type
== CHAN_SOCKDATA_DORMANT
) {
2968 logevent("Forwarded port closed");
2973 int sshfwd_write(struct ssh_channel
*c
, char *buf
, int len
)
2977 if (ssh
->version
== 1) {
2978 send_packet(ssh
, SSH1_MSG_CHANNEL_DATA
,
2979 PKT_INT
, c
->remoteid
,
2980 PKT_INT
, len
, PKT_DATA
, buf
, len
, PKT_END
);
2982 * In SSH1 we can return 0 here - implying that forwarded
2983 * connections are never individually throttled - because
2984 * the only circumstance that can cause throttling will be
2985 * the whole SSH connection backing up, in which case
2986 * _everything_ will be throttled as a whole.
2990 ssh2_add_channel_data(c
, buf
, len
);
2991 return ssh2_try_send(c
);
2995 void sshfwd_unthrottle(struct ssh_channel
*c
, int bufsize
)
2999 if (ssh
->version
== 1) {
3000 if (c
->v
.v1
.throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
3001 c
->v
.v1
.throttling
= 0;
3002 ssh1_throttle(ssh
, -1);
3005 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
3009 static void ssh1_protocol(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
3011 crBegin(ssh
->ssh1_protocol_crstate
);
3015 while (!do_ssh1_login(ssh
, in
, inlen
, ispkt
)) {
3018 if (ssh
->state
== SSH_STATE_CLOSED
)
3021 if (ssh
->cfg
.agentfwd
&& agent_exists()) {
3022 logevent("Requesting agent forwarding");
3023 send_packet(ssh
, SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
3027 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3028 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3029 bombout((ssh
,"Protocol confusion"));
3031 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3032 logevent("Agent forwarding refused");
3034 logevent("Agent forwarding enabled");
3035 ssh
->agentfwd_enabled
= TRUE
;
3039 if (ssh
->cfg
.x11_forward
) {
3040 char proto
[20], data
[64];
3041 logevent("Requesting X11 forwarding");
3042 ssh
->x11auth
= x11_invent_auth(proto
, sizeof(proto
),
3043 data
, sizeof(data
), ssh
->cfg
.x11_auth
);
3044 x11_get_real_auth(ssh
->x11auth
, ssh
->cfg
.x11_display
);
3045 if (ssh
->v1_local_protoflags
& SSH1_PROTOFLAG_SCREEN_NUMBER
) {
3046 send_packet(ssh
, SSH1_CMSG_X11_REQUEST_FORWARDING
,
3047 PKT_STR
, proto
, PKT_STR
, data
,
3048 PKT_INT
, x11_get_screen_number(ssh
->cfg
.x11_display
),
3051 send_packet(ssh
, SSH1_CMSG_X11_REQUEST_FORWARDING
,
3052 PKT_STR
, proto
, PKT_STR
, data
, PKT_END
);
3057 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3058 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3059 bombout((ssh
,"Protocol confusion"));
3061 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3062 logevent("X11 forwarding refused");
3064 logevent("X11 forwarding enabled");
3065 ssh
->X11_fwd_enabled
= TRUE
;
3072 int sport
,dport
,sserv
,dserv
;
3073 char sports
[256], dports
[256], saddr
[256], host
[256];
3075 ssh
->rportfwds
= newtree234(ssh_rportcmp_ssh1
);
3076 /* Add port forwardings. */
3077 ssh
->portfwd_strptr
= ssh
->cfg
.portfwd
;
3078 while (*ssh
->portfwd_strptr
) {
3079 type
= *ssh
->portfwd_strptr
++;
3082 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= '\t') {
3083 if (*ssh
->portfwd_strptr
== ':') {
3085 * We've seen a colon in the middle of the
3086 * source port number. This means that
3087 * everything we've seen until now is the
3088 * source _address_, so we'll move it into
3089 * saddr and start sports from the beginning
3092 ssh
->portfwd_strptr
++;
3094 strcpy(saddr
, sports
);
3097 if (n
< 255) sports
[n
++] = *ssh
->portfwd_strptr
++;
3100 if (*ssh
->portfwd_strptr
== '\t')
3101 ssh
->portfwd_strptr
++;
3103 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= ':') {
3104 if (n
< 255) host
[n
++] = *ssh
->portfwd_strptr
++;
3107 if (*ssh
->portfwd_strptr
== ':')
3108 ssh
->portfwd_strptr
++;
3110 while (*ssh
->portfwd_strptr
) {
3111 if (n
< 255) dports
[n
++] = *ssh
->portfwd_strptr
++;
3114 ssh
->portfwd_strptr
++;
3115 dport
= atoi(dports
);
3119 dport
= net_service_lookup(dports
);
3121 logeventf(ssh
, "Service lookup failed for"
3122 " destination port \"%s\"", dports
);
3125 sport
= atoi(sports
);
3129 sport
= net_service_lookup(sports
);
3131 logeventf(ssh
, "Service lookup failed for source"
3132 " port \"%s\"", sports
);
3135 if (sport
&& dport
) {
3137 pfd_addforward(host
, dport
, *saddr ? saddr
: NULL
,
3138 sport
, ssh
, &ssh
->cfg
);
3139 logeventf(ssh
, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3140 " forwarding to %s:%.*s%.*s%d%.*s",
3141 (int)(*saddr?
strlen(saddr
):0), *saddr?saddr
:NULL
,
3142 (int)(*saddr?
1:0), ":",
3143 (int)(sserv ?
strlen(sports
) : 0), sports
,
3144 sserv
, "(", sport
, sserv
, ")",
3146 (int)(dserv ?
strlen(dports
) : 0), dports
,
3147 dserv
, "(", dport
, dserv
, ")");
3149 struct ssh_rportfwd
*pf
;
3150 pf
= smalloc(sizeof(*pf
));
3151 strcpy(pf
->dhost
, host
);
3155 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
3158 if (add234(ssh
->rportfwds
, pf
) != pf
) {
3160 "Duplicate remote port forwarding to %s:%d",
3164 logeventf(ssh
, "Requesting remote port %.*s%.*s%d%.*s"
3165 " forward to %s:%.*s%.*s%d%.*s",
3166 (int)(sserv ?
strlen(sports
) : 0), sports
,
3167 sserv
, "(", sport
, sserv
, ")",
3169 (int)(dserv ?
strlen(dports
) : 0), dports
,
3170 dserv
, "(", dport
, dserv
, ")");
3171 send_packet(ssh
, SSH1_CMSG_PORT_FORWARD_REQUEST
,
3179 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3180 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3181 bombout((ssh
,"Protocol confusion"));
3183 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3184 c_write_str(ssh
, "Server refused port"
3187 logevent("Remote port forwarding enabled");
3194 if (!ssh
->cfg
.nopty
) {
3195 send_packet(ssh
, SSH1_CMSG_REQUEST_PTY
,
3196 PKT_STR
, ssh
->cfg
.termtype
,
3197 PKT_INT
, ssh
->term_height
,
3198 PKT_INT
, ssh
->term_width
,
3199 PKT_INT
, 0, PKT_INT
, 0, PKT_CHAR
, 0, PKT_END
);
3200 ssh
->state
= SSH_STATE_INTERMED
;
3204 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3205 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3206 bombout((ssh
,"Protocol confusion"));
3208 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3209 c_write_str(ssh
, "Server refused to allocate pty\r\n");
3210 ssh
->editing
= ssh
->echoing
= 1;
3212 logevent("Allocated pty");
3214 ssh
->editing
= ssh
->echoing
= 1;
3217 if (ssh
->cfg
.compression
) {
3218 send_packet(ssh
, SSH1_CMSG_REQUEST_COMPRESSION
, PKT_INT
, 6, PKT_END
);
3222 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3223 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3224 bombout((ssh
,"Protocol confusion"));
3226 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3227 c_write_str(ssh
, "Server refused to compress\r\n");
3229 logevent("Started compression");
3230 ssh
->v1_compressing
= TRUE
;
3231 ssh
->cs_comp_ctx
= zlib_compress_init();
3232 logevent("Initialised zlib (RFC1950) compression");
3233 ssh
->sc_comp_ctx
= zlib_decompress_init();
3234 logevent("Initialised zlib (RFC1950) decompression");
3238 * Start the shell or command.
3240 * Special case: if the first-choice command is an SSH2
3241 * subsystem (hence not usable here) and the second choice
3242 * exists, we fall straight back to that.
3245 char *cmd
= ssh
->cfg
.remote_cmd_ptr
;
3247 if (ssh
->cfg
.ssh_subsys
&& ssh
->cfg
.remote_cmd_ptr2
) {
3248 cmd
= ssh
->cfg
.remote_cmd_ptr2
;
3249 ssh
->fallback_cmd
= TRUE
;
3252 send_packet(ssh
, SSH1_CMSG_EXEC_CMD
, PKT_STR
, cmd
, PKT_END
);
3254 send_packet(ssh
, SSH1_CMSG_EXEC_SHELL
, PKT_END
);
3255 logevent("Started session");
3258 ssh
->state
= SSH_STATE_SESSION
;
3259 if (ssh
->size_needed
)
3260 ssh_size(ssh
, ssh
->term_width
, ssh
->term_height
);
3261 if (ssh
->eof_needed
)
3262 ssh_special(ssh
, TS_EOF
);
3265 ldisc_send(ssh
->ldisc
, NULL
, 0, 0);/* cause ldisc to notice changes */
3267 ssh
->channels
= newtree234(ssh_channelcmp
);
3271 if (ssh
->pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
3272 ssh
->pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
3273 long len
= GET_32BIT(ssh
->pktin
.body
);
3275 from_backend(ssh
->frontend
,
3276 ssh
->pktin
.type
== SSH1_SMSG_STDERR_DATA
,
3277 (char *)(ssh
->pktin
.body
) + 4, len
);
3278 if (!ssh
->v1_stdout_throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
3279 ssh
->v1_stdout_throttling
= 1;
3280 ssh1_throttle(ssh
, +1);
3282 } else if (ssh
->pktin
.type
== SSH1_MSG_DISCONNECT
) {
3283 ssh
->state
= SSH_STATE_CLOSED
;
3284 logevent("Received disconnect request");
3286 } else if (ssh
->pktin
.type
== SSH1_SMSG_X11_OPEN
) {
3287 /* Remote side is trying to open a channel to talk to our
3288 * X-Server. Give them back a local channel number. */
3289 struct ssh_channel
*c
;
3291 logevent("Received X11 connect request");
3292 /* Refuse if X11 forwarding is disabled. */
3293 if (!ssh
->X11_fwd_enabled
) {
3294 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3295 PKT_INT
, GET_32BIT(ssh
->pktin
.body
), PKT_END
);
3296 logevent("Rejected X11 connect request");
3298 c
= smalloc(sizeof(struct ssh_channel
));
3301 if (x11_init(&c
->u
.x11
.s
, ssh
->cfg
.x11_display
, c
,
3302 ssh
->x11auth
, NULL
, -1, &ssh
->cfg
) != NULL
) {
3303 logevent("opening X11 forward connection failed");
3305 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3306 PKT_INT
, GET_32BIT(ssh
->pktin
.body
),
3310 ("opening X11 forward connection succeeded");
3311 c
->remoteid
= GET_32BIT(ssh
->pktin
.body
);
3312 c
->localid
= alloc_channel_id(ssh
);
3314 c
->v
.v1
.throttling
= 0;
3315 c
->type
= CHAN_X11
; /* identify channel type */
3316 add234(ssh
->channels
, c
);
3317 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3318 PKT_INT
, c
->remoteid
, PKT_INT
,
3319 c
->localid
, PKT_END
);
3320 logevent("Opened X11 forward channel");
3323 } else if (ssh
->pktin
.type
== SSH1_SMSG_AGENT_OPEN
) {
3324 /* Remote side is trying to open a channel to talk to our
3325 * agent. Give them back a local channel number. */
3326 struct ssh_channel
*c
;
3328 /* Refuse if agent forwarding is disabled. */
3329 if (!ssh
->agentfwd_enabled
) {
3330 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3331 PKT_INT
, GET_32BIT(ssh
->pktin
.body
), PKT_END
);
3333 c
= smalloc(sizeof(struct ssh_channel
));
3335 c
->remoteid
= GET_32BIT(ssh
->pktin
.body
);
3336 c
->localid
= alloc_channel_id(ssh
);
3338 c
->v
.v1
.throttling
= 0;
3339 c
->type
= CHAN_AGENT
; /* identify channel type */
3340 c
->u
.a
.lensofar
= 0;
3341 add234(ssh
->channels
, c
);
3342 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3343 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
3346 } else if (ssh
->pktin
.type
== SSH1_MSG_PORT_OPEN
) {
3347 /* Remote side is trying to open a channel to talk to a
3348 * forwarded port. Give them back a local channel number. */
3349 struct ssh_channel
*c
;
3350 struct ssh_rportfwd pf
;
3352 char host
[256], buf
[1024];
3354 c
= smalloc(sizeof(struct ssh_channel
));
3357 hostsize
= GET_32BIT(ssh
->pktin
.body
+4);
3358 for (h
= host
, p
= (char *)(ssh
->pktin
.body
+8);
3359 hostsize
!= 0; hostsize
--) {
3360 if (h
+1 < host
+sizeof(host
))
3365 port
= GET_32BIT(p
);
3367 strcpy(pf
.dhost
, host
);
3370 if (find234(ssh
->rportfwds
, &pf
, NULL
) == NULL
) {
3371 sprintf(buf
, "Rejected remote port open request for %s:%d",
3374 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3375 PKT_INT
, GET_32BIT(ssh
->pktin
.body
), PKT_END
);
3377 sprintf(buf
, "Received remote port open request for %s:%d",
3380 e
= pfd_newconnect(&c
->u
.pfd
.s
, host
, port
, c
, &ssh
->cfg
);
3383 sprintf(buf
, "Port open failed: %s", e
);
3386 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3387 PKT_INT
, GET_32BIT(ssh
->pktin
.body
),
3390 c
->remoteid
= GET_32BIT(ssh
->pktin
.body
);
3391 c
->localid
= alloc_channel_id(ssh
);
3393 c
->v
.v1
.throttling
= 0;
3394 c
->type
= CHAN_SOCKDATA
; /* identify channel type */
3395 add234(ssh
->channels
, c
);
3396 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3397 PKT_INT
, c
->remoteid
, PKT_INT
,
3398 c
->localid
, PKT_END
);
3399 logevent("Forwarded port opened successfully");
3403 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
) {
3404 unsigned int remoteid
= GET_32BIT(ssh
->pktin
.body
);
3405 unsigned int localid
= GET_32BIT(ssh
->pktin
.body
+4);
3406 struct ssh_channel
*c
;
3408 c
= find234(ssh
->channels
, &remoteid
, ssh_channelfind
);
3409 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
3410 c
->remoteid
= localid
;
3411 c
->type
= CHAN_SOCKDATA
;
3412 c
->v
.v1
.throttling
= 0;
3413 pfd_confirm(c
->u
.pfd
.s
);
3416 if (c
&& c
->closes
) {
3418 * We have a pending close on this channel,
3419 * which we decided on before the server acked
3420 * the channel open. So now we know the
3421 * remoteid, we can close it again.
3423 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE
,
3424 PKT_INT
, c
->remoteid
, PKT_END
);
3427 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_OPEN_FAILURE
) {
3428 unsigned int remoteid
= GET_32BIT(ssh
->pktin
.body
);
3429 struct ssh_channel
*c
;
3431 c
= find234(ssh
->channels
, &remoteid
, ssh_channelfind
);
3432 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
3433 logevent("Forwarded connection refused by server");
3434 pfd_close(c
->u
.pfd
.s
);
3435 del234(ssh
->channels
, c
);
3439 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE
||
3440 ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
) {
3441 /* Remote side closes a channel. */
3442 unsigned i
= GET_32BIT(ssh
->pktin
.body
);
3443 struct ssh_channel
*c
;
3444 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
3445 if (c
&& ((int)c
->remoteid
) != -1) {
3448 (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
1 : 2);
3450 if ((c
->closes
== 0) && (c
->type
== CHAN_X11
)) {
3451 logevent("Forwarded X11 connection terminated");
3452 assert(c
->u
.x11
.s
!= NULL
);
3453 x11_close(c
->u
.x11
.s
);
3456 if ((c
->closes
== 0) && (c
->type
== CHAN_SOCKDATA
)) {
3457 logevent("Forwarded port closed");
3458 assert(c
->u
.pfd
.s
!= NULL
);
3459 pfd_close(c
->u
.pfd
.s
);
3463 c
->closes
|= (closetype
<< 2); /* seen this message */
3464 if (!(c
->closes
& closetype
)) {
3465 send_packet(ssh
, ssh
->pktin
.type
, PKT_INT
, c
->remoteid
,
3467 c
->closes
|= closetype
; /* sent it too */
3470 if (c
->closes
== 15) {
3471 del234(ssh
->channels
, c
);
3475 bombout((ssh
,"Received CHANNEL_CLOSE%s for %s channel %d\n",
3476 ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
"" :
3477 "_CONFIRMATION", c ?
"half-open" : "nonexistent",
3480 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_DATA
) {
3481 /* Data sent down one of our channels. */
3482 int i
= GET_32BIT(ssh
->pktin
.body
);
3483 int len
= GET_32BIT(ssh
->pktin
.body
+ 4);
3484 unsigned char *p
= ssh
->pktin
.body
+ 8;
3485 struct ssh_channel
*c
;
3486 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
3491 bufsize
= x11_send(c
->u
.x11
.s
, (char *)p
, len
);
3494 bufsize
= pfd_send(c
->u
.pfd
.s
, (char *)p
, len
);
3497 /* Data for an agent message. Buffer it. */
3499 if (c
->u
.a
.lensofar
< 4) {
3500 int l
= min(4 - c
->u
.a
.lensofar
, len
);
3501 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
,
3505 c
->u
.a
.lensofar
+= l
;
3507 if (c
->u
.a
.lensofar
== 4) {
3509 4 + GET_32BIT(c
->u
.a
.msglen
);
3510 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
3511 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
3513 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
3515 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
3517 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
,
3521 c
->u
.a
.lensofar
+= l
;
3523 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
3524 void *reply
, *sentreply
;
3526 agent_query(c
->u
.a
.message
,
3527 c
->u
.a
.totallen
, &reply
,
3532 /* Fake SSH_AGENT_FAILURE. */
3533 sentreply
= "\0\0\0\1\5";
3536 send_packet(ssh
, SSH1_MSG_CHANNEL_DATA
,
3537 PKT_INT
, c
->remoteid
,
3539 PKT_DATA
, sentreply
, replylen
,
3543 sfree(c
->u
.a
.message
);
3544 c
->u
.a
.lensofar
= 0;
3547 bufsize
= 0; /* agent channels never back up */
3550 if (!c
->v
.v1
.throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
3551 c
->v
.v1
.throttling
= 1;
3552 ssh1_throttle(ssh
, +1);
3555 } else if (ssh
->pktin
.type
== SSH1_SMSG_SUCCESS
) {
3556 /* may be from EXEC_SHELL on some servers */
3557 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3558 /* may be from EXEC_SHELL on some servers
3559 * if no pty is available or in other odd cases. Ignore */
3560 } else if (ssh
->pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
3562 ssh
->exitcode
= GET_32BIT(ssh
->pktin
.body
);
3563 sprintf(buf
, "Server sent command exit status %d",
3566 send_packet(ssh
, SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
3568 * In case `helpful' firewalls or proxies tack
3569 * extra human-readable text on the end of the
3570 * session which we might mistake for another
3571 * encrypted packet, we close the session once
3572 * we've sent EXIT_CONFIRMATION.
3574 ssh
->state
= SSH_STATE_CLOSED
;
3577 bombout((ssh
,"Strange packet received: type %d", ssh
->pktin
.type
));
3582 int len
= min(inlen
, 512);
3583 send_packet(ssh
, SSH1_CMSG_STDIN_DATA
,
3584 PKT_INT
, len
, PKT_DATA
, in
, len
, PKT_END
);
3595 * Utility routine for decoding comma-separated strings in KEXINIT.
3597 static int in_commasep_string(char *needle
, char *haystack
, int haylen
)
3600 if (!needle
|| !haystack
) /* protect against null pointers */
3602 needlen
= strlen(needle
);
3605 * Is it at the start of the string?
3607 if (haylen
>= needlen
&& /* haystack is long enough */
3608 !memcmp(needle
, haystack
, needlen
) && /* initial match */
3609 (haylen
== needlen
|| haystack
[needlen
] == ',')
3610 /* either , or EOS follows */
3614 * If not, search for the next comma and resume after that.
3615 * If no comma found, terminate.
3617 while (haylen
> 0 && *haystack
!= ',')
3618 haylen
--, haystack
++;
3621 haylen
--, haystack
++; /* skip over comma itself */
3626 * SSH2 key creation method.
3628 static void ssh2_mkkey(Ssh ssh
, Bignum K
, unsigned char *H
,
3629 unsigned char *sessid
, char chr
,
3630 unsigned char *keyspace
)
3633 /* First 20 bytes. */
3635 if (!(ssh
->remote_bugs
& BUG_SSH2_DERIVEKEY
))
3637 SHA_Bytes(&s
, H
, 20);
3638 SHA_Bytes(&s
, &chr
, 1);
3639 SHA_Bytes(&s
, sessid
, 20);
3640 SHA_Final(&s
, keyspace
);
3641 /* Next 20 bytes. */
3643 if (!(ssh
->remote_bugs
& BUG_SSH2_DERIVEKEY
))
3645 SHA_Bytes(&s
, H
, 20);
3646 SHA_Bytes(&s
, keyspace
, 20);
3647 SHA_Final(&s
, keyspace
+ 20);
3651 * Handle the SSH2 transport layer.
3653 static int do_ssh2_transport(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
3655 struct do_ssh2_transport_state
{
3656 int nbits
, pbits
, warn
;
3657 Bignum p
, g
, e
, f
, K
;
3658 int kex_init_value
, kex_reply_value
;
3659 const struct ssh_mac
**maclist
;
3661 const struct ssh2_cipher
*cscipher_tobe
;
3662 const struct ssh2_cipher
*sccipher_tobe
;
3663 const struct ssh_mac
*csmac_tobe
;
3664 const struct ssh_mac
*scmac_tobe
;
3665 const struct ssh_compress
*cscomp_tobe
;
3666 const struct ssh_compress
*sccomp_tobe
;
3667 char *hostkeydata
, *sigdata
, *keystr
, *fingerprint
;
3668 int hostkeylen
, siglen
;
3669 void *hkey
; /* actual host key */
3670 unsigned char exchange_hash
[20];
3671 int n_preferred_ciphers
;
3672 const struct ssh2_ciphers
*preferred_ciphers
[CIPHER_MAX
];
3673 const struct ssh_compress
*preferred_comp
;
3676 crState(do_ssh2_transport_state
);
3678 crBegin(ssh
->do_ssh2_transport_crstate
);
3680 s
->cscipher_tobe
= s
->sccipher_tobe
= NULL
;
3681 s
->csmac_tobe
= s
->scmac_tobe
= NULL
;
3682 s
->cscomp_tobe
= s
->sccomp_tobe
= NULL
;
3690 * Set up the preferred ciphers. (NULL => warn below here)
3692 s
->n_preferred_ciphers
= 0;
3693 for (i
= 0; i
< CIPHER_MAX
; i
++) {
3694 switch (ssh
->cfg
.ssh_cipherlist
[i
]) {
3695 case CIPHER_BLOWFISH
:
3696 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_blowfish
;
3699 if (ssh
->cfg
.ssh2_des_cbc
) {
3700 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_des
;
3704 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_3des
;
3707 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_aes
;
3710 /* Flag for later. Don't bother if it's the last in
3712 if (i
< CIPHER_MAX
- 1) {
3713 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = NULL
;
3721 * Set up preferred compression.
3723 if (ssh
->cfg
.compression
)
3724 s
->preferred_comp
= &ssh_zlib
;
3726 s
->preferred_comp
= &ssh_comp_none
;
3729 * Be prepared to work around the buggy MAC problem.
3731 if (ssh
->remote_bugs
& BUG_SSH2_HMAC
)
3732 s
->maclist
= buggymacs
, s
->nmacs
= lenof(buggymacs
);
3734 s
->maclist
= macs
, s
->nmacs
= lenof(macs
);
3738 int i
, j
, cipherstr_started
;
3741 * Construct and send our key exchange packet.
3743 ssh2_pkt_init(ssh
, SSH2_MSG_KEXINIT
);
3744 for (i
= 0; i
< 16; i
++)
3745 ssh2_pkt_addbyte(ssh
, (unsigned char) random_byte());
3746 /* List key exchange algorithms. */
3747 ssh2_pkt_addstring_start(ssh
);
3748 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3749 if (kex_algs
[i
] == &ssh_diffiehellman_gex
&&
3750 (ssh
->remote_bugs
& BUG_SSH2_DH_GEX
))
3752 ssh2_pkt_addstring_str(ssh
, kex_algs
[i
]->name
);
3753 if (i
< lenof(kex_algs
) - 1)
3754 ssh2_pkt_addstring_str(ssh
, ",");
3756 /* List server host key algorithms. */
3757 ssh2_pkt_addstring_start(ssh
);
3758 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3759 ssh2_pkt_addstring_str(ssh
, hostkey_algs
[i
]->name
);
3760 if (i
< lenof(hostkey_algs
) - 1)
3761 ssh2_pkt_addstring_str(ssh
, ",");
3763 /* List client->server 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 server->client encryption algorithms. */
3777 ssh2_pkt_addstring_start(ssh
);
3778 cipherstr_started
= 0;
3779 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
3780 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
3781 if (!c
) continue; /* warning flag */
3782 for (j
= 0; j
< c
->nciphers
; j
++) {
3783 if (cipherstr_started
)
3784 ssh2_pkt_addstring_str(ssh
, ",");
3785 ssh2_pkt_addstring_str(ssh
, c
->list
[j
]->name
);
3786 cipherstr_started
= 1;
3789 /* List client->server MAC algorithms. */
3790 ssh2_pkt_addstring_start(ssh
);
3791 for (i
= 0; i
< s
->nmacs
; i
++) {
3792 ssh2_pkt_addstring_str(ssh
, s
->maclist
[i
]->name
);
3793 if (i
< s
->nmacs
- 1)
3794 ssh2_pkt_addstring_str(ssh
, ",");
3796 /* List server->client MAC algorithms. */
3797 ssh2_pkt_addstring_start(ssh
);
3798 for (i
= 0; i
< s
->nmacs
; i
++) {
3799 ssh2_pkt_addstring_str(ssh
, s
->maclist
[i
]->name
);
3800 if (i
< s
->nmacs
- 1)
3801 ssh2_pkt_addstring_str(ssh
, ",");
3803 /* List client->server compression algorithms. */
3804 ssh2_pkt_addstring_start(ssh
);
3805 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3806 const struct ssh_compress
*c
=
3807 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
3808 ssh2_pkt_addstring_str(ssh
, c
->name
);
3809 if (i
< lenof(compressions
))
3810 ssh2_pkt_addstring_str(ssh
, ",");
3812 /* List server->client compression algorithms. */
3813 ssh2_pkt_addstring_start(ssh
);
3814 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3815 const struct ssh_compress
*c
=
3816 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
3817 ssh2_pkt_addstring_str(ssh
, c
->name
);
3818 if (i
< lenof(compressions
))
3819 ssh2_pkt_addstring_str(ssh
, ",");
3821 /* List client->server languages. Empty list. */
3822 ssh2_pkt_addstring_start(ssh
);
3823 /* List server->client languages. Empty list. */
3824 ssh2_pkt_addstring_start(ssh
);
3825 /* First KEX packet does _not_ follow, because we're not that brave. */
3826 ssh2_pkt_addbool(ssh
, FALSE
);
3828 ssh2_pkt_adduint32(ssh
, 0);
3831 ssh
->exhash
= ssh
->exhashbase
;
3832 sha_string(&ssh
->exhash
, ssh
->pktout
.data
+ 5, ssh
->pktout
.length
- 5);
3838 if (ssh
->pktin
.length
> 5)
3839 sha_string(&ssh
->exhash
, ssh
->pktin
.data
+ 5, ssh
->pktin
.length
- 5);
3842 * Now examine the other side's KEXINIT to see what we're up
3849 if (ssh
->pktin
.type
!= SSH2_MSG_KEXINIT
) {
3850 bombout((ssh
,"expected key exchange packet from server"));
3854 ssh
->hostkey
= NULL
;
3855 s
->cscipher_tobe
= NULL
;
3856 s
->sccipher_tobe
= NULL
;
3857 s
->csmac_tobe
= NULL
;
3858 s
->scmac_tobe
= NULL
;
3859 s
->cscomp_tobe
= NULL
;
3860 s
->sccomp_tobe
= NULL
;
3861 ssh
->pktin
.savedpos
+= 16; /* skip garbage cookie */
3862 ssh2_pkt_getstring(ssh
, &str
, &len
); /* key exchange algorithms */
3863 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3864 if (kex_algs
[i
] == &ssh_diffiehellman_gex
&&
3865 (ssh
->remote_bugs
& BUG_SSH2_DH_GEX
))
3867 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
3868 ssh
->kex
= kex_algs
[i
];
3872 ssh2_pkt_getstring(ssh
, &str
, &len
); /* host key algorithms */
3873 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3874 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
3875 ssh
->hostkey
= hostkey_algs
[i
];
3879 ssh2_pkt_getstring(ssh
, &str
, &len
); /* client->server cipher */
3881 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
3882 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
3886 for (j
= 0; j
< c
->nciphers
; j
++) {
3887 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3888 s
->cscipher_tobe
= c
->list
[j
];
3893 if (s
->cscipher_tobe
) {
3895 askcipher(ssh
->frontend
, s
->cscipher_tobe
->name
, 1);
3899 if (!s
->cscipher_tobe
) {
3900 bombout((ssh
,"Couldn't agree a client-to-server cipher (available: %s)",
3901 str ? str
: "(null)"));
3905 ssh2_pkt_getstring(ssh
, &str
, &len
); /* server->client cipher */
3907 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
3908 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
3912 for (j
= 0; j
< c
->nciphers
; j
++) {
3913 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3914 s
->sccipher_tobe
= c
->list
[j
];
3919 if (s
->sccipher_tobe
) {
3921 askcipher(ssh
->frontend
, s
->sccipher_tobe
->name
, 2);
3925 if (!s
->sccipher_tobe
) {
3926 bombout((ssh
,"Couldn't agree a server-to-client cipher (available: %s)",
3927 str ? str
: "(null)"));
3931 ssh2_pkt_getstring(ssh
, &str
, &len
); /* client->server mac */
3932 for (i
= 0; i
< s
->nmacs
; i
++) {
3933 if (in_commasep_string(s
->maclist
[i
]->name
, str
, len
)) {
3934 s
->csmac_tobe
= s
->maclist
[i
];
3938 ssh2_pkt_getstring(ssh
, &str
, &len
); /* server->client mac */
3939 for (i
= 0; i
< s
->nmacs
; i
++) {
3940 if (in_commasep_string(s
->maclist
[i
]->name
, str
, len
)) {
3941 s
->scmac_tobe
= s
->maclist
[i
];
3945 ssh2_pkt_getstring(ssh
, &str
, &len
); /* client->server compression */
3946 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3947 const struct ssh_compress
*c
=
3948 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
3949 if (in_commasep_string(c
->name
, str
, len
)) {
3954 ssh2_pkt_getstring(ssh
, &str
, &len
); /* server->client compression */
3955 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3956 const struct ssh_compress
*c
=
3957 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
3958 if (in_commasep_string(c
->name
, str
, len
)) {
3966 * Work out the number of bits of key we will need from the key
3967 * exchange. We start with the maximum key length of either
3973 csbits
= s
->cscipher_tobe
->keylen
;
3974 scbits
= s
->sccipher_tobe
->keylen
;
3975 s
->nbits
= (csbits
> scbits ? csbits
: scbits
);
3977 /* The keys only have 160-bit entropy, since they're based on
3978 * a SHA-1 hash. So cap the key size at 160 bits. */
3983 * If we're doing Diffie-Hellman group exchange, start by
3984 * requesting a group.
3986 if (ssh
->kex
== &ssh_diffiehellman_gex
) {
3987 logevent("Doing Diffie-Hellman group exchange");
3988 ssh
->pkt_ctx
|= SSH2_PKTCTX_DHGEX
;
3990 * Work out how big a DH group we will need to allow that
3993 s
->pbits
= 512 << ((s
->nbits
- 1) / 64);
3994 ssh2_pkt_init(ssh
, SSH2_MSG_KEX_DH_GEX_REQUEST
);
3995 ssh2_pkt_adduint32(ssh
, s
->pbits
);
3999 if (ssh
->pktin
.type
!= SSH2_MSG_KEX_DH_GEX_GROUP
) {
4000 bombout((ssh
,"expected key exchange group packet from server"));
4003 s
->p
= ssh2_pkt_getmp(ssh
);
4004 s
->g
= ssh2_pkt_getmp(ssh
);
4005 ssh
->kex_ctx
= dh_setup_group(s
->p
, s
->g
);
4006 s
->kex_init_value
= SSH2_MSG_KEX_DH_GEX_INIT
;
4007 s
->kex_reply_value
= SSH2_MSG_KEX_DH_GEX_REPLY
;
4009 ssh
->pkt_ctx
|= SSH2_PKTCTX_DHGROUP1
;
4010 ssh
->kex_ctx
= dh_setup_group1();
4011 s
->kex_init_value
= SSH2_MSG_KEXDH_INIT
;
4012 s
->kex_reply_value
= SSH2_MSG_KEXDH_REPLY
;
4015 logevent("Doing Diffie-Hellman key exchange");
4017 * Now generate and send e for Diffie-Hellman.
4019 s
->e
= dh_create_e(ssh
->kex_ctx
, s
->nbits
* 2);
4020 ssh2_pkt_init(ssh
, s
->kex_init_value
);
4021 ssh2_pkt_addmp(ssh
, s
->e
);
4025 if (ssh
->pktin
.type
!= s
->kex_reply_value
) {
4026 bombout((ssh
,"expected key exchange reply packet from server"));
4029 ssh2_pkt_getstring(ssh
, &s
->hostkeydata
, &s
->hostkeylen
);
4030 s
->f
= ssh2_pkt_getmp(ssh
);
4031 ssh2_pkt_getstring(ssh
, &s
->sigdata
, &s
->siglen
);
4033 s
->K
= dh_find_K(ssh
->kex_ctx
, s
->f
);
4035 sha_string(&ssh
->exhash
, s
->hostkeydata
, s
->hostkeylen
);
4036 if (ssh
->kex
== &ssh_diffiehellman_gex
) {
4037 sha_uint32(&ssh
->exhash
, s
->pbits
);
4038 sha_mpint(&ssh
->exhash
, s
->p
);
4039 sha_mpint(&ssh
->exhash
, s
->g
);
4041 sha_mpint(&ssh
->exhash
, s
->e
);
4042 sha_mpint(&ssh
->exhash
, s
->f
);
4043 sha_mpint(&ssh
->exhash
, s
->K
);
4044 SHA_Final(&ssh
->exhash
, s
->exchange_hash
);
4046 dh_cleanup(ssh
->kex_ctx
);
4047 ssh
->kex_ctx
= NULL
;
4050 debug(("Exchange hash is:\n"));
4051 dmemdump(s
->exchange_hash
, 20);
4054 s
->hkey
= ssh
->hostkey
->newkey(s
->hostkeydata
, s
->hostkeylen
);
4056 !ssh
->hostkey
->verifysig(s
->hkey
, s
->sigdata
, s
->siglen
,
4057 (char *)s
->exchange_hash
, 20)) {
4058 bombout((ssh
,"Server's host key did not match the signature supplied"));
4063 * Authenticate remote host: verify host key. (We've already
4064 * checked the signature of the exchange hash.)
4066 s
->keystr
= ssh
->hostkey
->fmtkey(s
->hkey
);
4067 s
->fingerprint
= ssh
->hostkey
->fingerprint(s
->hkey
);
4068 verify_ssh_host_key(ssh
->frontend
,
4069 ssh
->savedhost
, ssh
->savedport
, ssh
->hostkey
->keytype
,
4070 s
->keystr
, s
->fingerprint
);
4071 if (s
->first_kex
) { /* don't bother logging this in rekeys */
4072 logevent("Host key fingerprint is:");
4073 logevent(s
->fingerprint
);
4075 sfree(s
->fingerprint
);
4077 ssh
->hostkey
->freekey(s
->hkey
);
4080 * Send SSH2_MSG_NEWKEYS.
4082 ssh2_pkt_init(ssh
, SSH2_MSG_NEWKEYS
);
4086 * Expect SSH2_MSG_NEWKEYS from server.
4089 if (ssh
->pktin
.type
!= SSH2_MSG_NEWKEYS
) {
4090 bombout((ssh
,"expected new-keys packet from server"));
4095 * Create and initialise session keys.
4097 if (ssh
->cs_cipher_ctx
)
4098 ssh
->cscipher
->free_context(ssh
->cs_cipher_ctx
);
4099 ssh
->cscipher
= s
->cscipher_tobe
;
4100 ssh
->cs_cipher_ctx
= ssh
->cscipher
->make_context();
4102 if (ssh
->sc_cipher_ctx
)
4103 ssh
->sccipher
->free_context(ssh
->sc_cipher_ctx
);
4104 ssh
->sccipher
= s
->sccipher_tobe
;
4105 ssh
->sc_cipher_ctx
= ssh
->sccipher
->make_context();
4107 if (ssh
->cs_mac_ctx
)
4108 ssh
->csmac
->free_context(ssh
->cs_mac_ctx
);
4109 ssh
->csmac
= s
->csmac_tobe
;
4110 ssh
->cs_mac_ctx
= ssh
->csmac
->make_context();
4112 if (ssh
->sc_mac_ctx
)
4113 ssh
->scmac
->free_context(ssh
->sc_mac_ctx
);
4114 ssh
->scmac
= s
->scmac_tobe
;
4115 ssh
->sc_mac_ctx
= ssh
->scmac
->make_context();
4117 if (ssh
->cs_comp_ctx
)
4118 ssh
->cscomp
->compress_cleanup(ssh
->cs_comp_ctx
);
4119 ssh
->cscomp
= s
->cscomp_tobe
;
4120 ssh
->cs_comp_ctx
= ssh
->cscomp
->compress_init();
4122 if (ssh
->sc_comp_ctx
)
4123 ssh
->sccomp
->decompress_cleanup(ssh
->sc_comp_ctx
);
4124 ssh
->sccomp
= s
->sccomp_tobe
;
4125 ssh
->sc_comp_ctx
= ssh
->sccomp
->decompress_init();
4128 * Set IVs after keys. Here we use the exchange hash from the
4129 * _first_ key exchange.
4132 unsigned char keyspace
[40];
4134 memcpy(ssh
->v2_session_id
, s
->exchange_hash
,
4135 sizeof(s
->exchange_hash
));
4136 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'C',keyspace
);
4137 ssh
->cscipher
->setkey(ssh
->cs_cipher_ctx
, keyspace
);
4138 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'D',keyspace
);
4139 ssh
->sccipher
->setkey(ssh
->sc_cipher_ctx
, keyspace
);
4140 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'A',keyspace
);
4141 ssh
->cscipher
->setiv(ssh
->cs_cipher_ctx
, keyspace
);
4142 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'B',keyspace
);
4143 ssh
->sccipher
->setiv(ssh
->sc_cipher_ctx
, keyspace
);
4144 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'E',keyspace
);
4145 ssh
->csmac
->setkey(ssh
->cs_mac_ctx
, keyspace
);
4146 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'F',keyspace
);
4147 ssh
->scmac
->setkey(ssh
->sc_mac_ctx
, keyspace
);
4149 logeventf(ssh
, "Initialised %.200s client->server encryption",
4150 ssh
->cscipher
->text_name
);
4151 logeventf(ssh
, "Initialised %.200s server->client encryption",
4152 ssh
->sccipher
->text_name
);
4153 if (ssh
->cscomp
->text_name
)
4154 logeventf(ssh
, "Initialised %s compression",
4155 ssh
->cscomp
->text_name
);
4156 if (ssh
->sccomp
->text_name
)
4157 logeventf(ssh
, "Initialised %s decompression",
4158 ssh
->sccomp
->text_name
);
4161 * If this is the first key exchange phase, we must pass the
4162 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4163 * wants to see it but because it will need time to initialise
4164 * itself before it sees an actual packet. In subsequent key
4165 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4166 * it would only confuse the layer above.
4168 if (!s
->first_kex
) {
4174 * Now we're encrypting. Begin returning 1 to the protocol main
4175 * function so that other things can run on top of the
4176 * transport. If we ever see a KEXINIT, we must go back to the
4179 while (!(ispkt
&& ssh
->pktin
.type
== SSH2_MSG_KEXINIT
)) {
4182 logevent("Server initiated key re-exchange");
4183 goto begin_key_exchange
;
4189 * Add data to an SSH2 channel output buffer.
4191 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
4194 bufchain_add(&c
->v
.v2
.outbuffer
, buf
, len
);
4198 * Attempt to send data on an SSH2 channel.
4200 static int ssh2_try_send(struct ssh_channel
*c
)
4204 while (c
->v
.v2
.remwindow
> 0 && bufchain_size(&c
->v
.v2
.outbuffer
) > 0) {
4207 bufchain_prefix(&c
->v
.v2
.outbuffer
, &data
, &len
);
4208 if ((unsigned)len
> c
->v
.v2
.remwindow
)
4209 len
= c
->v
.v2
.remwindow
;
4210 if ((unsigned)len
> c
->v
.v2
.remmaxpkt
)
4211 len
= c
->v
.v2
.remmaxpkt
;
4212 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_DATA
);
4213 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
4214 ssh2_pkt_addstring_start(ssh
);
4215 ssh2_pkt_addstring_data(ssh
, data
, len
);
4217 bufchain_consume(&c
->v
.v2
.outbuffer
, len
);
4218 c
->v
.v2
.remwindow
-= len
;
4222 * After having sent as much data as we can, return the amount
4225 return bufchain_size(&c
->v
.v2
.outbuffer
);
4229 * Potentially enlarge the window on an SSH2 channel.
4231 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
)
4236 * Never send WINDOW_ADJUST for a channel that the remote side
4237 * already thinks it's closed; there's no point, since it won't
4238 * be sending any more data anyway.
4243 if (newwin
> c
->v
.v2
.locwindow
) {
4244 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4245 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
4246 ssh2_pkt_adduint32(ssh
, newwin
- c
->v
.v2
.locwindow
);
4248 c
->v
.v2
.locwindow
= newwin
;
4253 * Handle the SSH2 userauth and connection layers.
4255 static void do_ssh2_authconn(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
4257 struct do_ssh2_authconn_state
{
4259 AUTH_INVALID
, AUTH_PUBLICKEY_AGENT
, AUTH_PUBLICKEY_FILE
,
4261 AUTH_KEYBOARD_INTERACTIVE
4265 AUTH_TYPE_PUBLICKEY
,
4266 AUTH_TYPE_PUBLICKEY_OFFER_LOUD
,
4267 AUTH_TYPE_PUBLICKEY_OFFER_QUIET
,
4269 AUTH_TYPE_KEYBOARD_INTERACTIVE
,
4270 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4272 int gotit
, need_pw
, can_pubkey
, can_passwd
, can_keyb_inter
;
4273 int tried_pubkey_config
, tried_agent
, tried_keyb_inter
;
4274 int kbd_inter_running
;
4276 int num_prompts
, curr_prompt
, echo
;
4281 void *publickey_blob
;
4282 int publickey_bloblen
;
4283 unsigned char request
[5], *response
, *p
;
4287 char *pkblob
, *alg
, *commentp
;
4288 int pklen
, alglen
, commentlen
;
4289 int siglen
, retlen
, len
;
4290 char *q
, *agentreq
, *ret
;
4293 crState(do_ssh2_authconn_state
);
4295 crBegin(ssh
->do_ssh2_authconn_crstate
);
4298 * Request userauth protocol, and await a response to it.
4300 ssh2_pkt_init(ssh
, SSH2_MSG_SERVICE_REQUEST
);
4301 ssh2_pkt_addstring(ssh
, "ssh-userauth");
4303 crWaitUntilV(ispkt
);
4304 if (ssh
->pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
) {
4305 bombout((ssh
,"Server refused user authentication protocol"));
4310 * We repeat this whole loop, including the username prompt,
4311 * until we manage a successful authentication. If the user
4312 * types the wrong _password_, they can be sent back to the
4313 * beginning to try another username, if this is configured on.
4314 * (If they specify a username in the config, they are never
4315 * asked, even if they do give a wrong password.)
4317 * I think this best serves the needs of
4319 * - the people who have no configuration, no keys, and just
4320 * want to try repeated (username,password) pairs until they
4321 * type both correctly
4323 * - people who have keys and configuration but occasionally
4324 * need to fall back to passwords
4326 * - people with a key held in Pageant, who might not have
4327 * logged in to a particular machine before; so they want to
4328 * type a username, and then _either_ their key will be
4329 * accepted, _or_ they will type a password. If they mistype
4330 * the username they will want to be able to get back and
4333 s
->username
[0] = '\0';
4334 s
->got_username
= FALSE
;
4339 if (s
->got_username
&& !ssh
->cfg
.change_username
) {
4341 * We got a username last time round this loop, and
4342 * with change_username turned off we don't try to get
4345 } else if ((flags
& FLAG_INTERACTIVE
) && !*ssh
->cfg
.username
) {
4346 if (ssh_get_line
&& !ssh_getline_pw_only
) {
4347 if (!ssh_get_line("login as: ",
4348 s
->username
, sizeof(s
->username
), FALSE
)) {
4350 * get_line failed to get a username.
4353 logevent("No username provided. Abandoning session.");
4354 ssh
->state
= SSH_STATE_CLOSED
;
4358 int ret
; /* need not be saved across crReturn */
4359 c_write_str(ssh
, "login as: ");
4361 setup_userpass_input(ssh
, s
->username
, sizeof(s
->username
), 1);
4363 crWaitUntilV(!ispkt
);
4364 ret
= process_userpass_input(ssh
, in
, inlen
);
4368 c_write_str(ssh
, "\r\n");
4370 s
->username
[strcspn(s
->username
, "\n\r")] = '\0';
4373 strncpy(s
->username
, ssh
->cfg
.username
, sizeof(s
->username
));
4374 s
->username
[sizeof(s
->username
)-1] = '\0';
4375 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
4376 stuff
= dupprintf("Using username \"%s\".\r\n", s
->username
);
4377 c_write_str(ssh
, stuff
);
4381 s
->got_username
= TRUE
;
4384 * Send an authentication request using method "none": (a)
4385 * just in case it succeeds, and (b) so that we know what
4386 * authentication methods we can usefully try next.
4388 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4390 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4391 ssh2_pkt_addstring(ssh
, s
->username
);
4392 ssh2_pkt_addstring(ssh
, "ssh-connection");/* service requested */
4393 ssh2_pkt_addstring(ssh
, "none"); /* method */
4395 s
->type
= AUTH_TYPE_NONE
;
4397 s
->we_are_in
= FALSE
;
4399 s
->tried_pubkey_config
= FALSE
;
4400 s
->tried_agent
= FALSE
;
4401 s
->tried_keyb_inter
= FALSE
;
4402 s
->kbd_inter_running
= FALSE
;
4403 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
4404 if (!filename_is_null(ssh
->cfg
.keyfile
)) {
4406 logeventf(ssh
, "Reading private key file \"%.150s\"",
4407 filename_to_str(&ssh
->cfg
.keyfile
));
4408 keytype
= key_type(&ssh
->cfg
.keyfile
);
4409 if (keytype
== SSH_KEYTYPE_SSH2
) {
4411 ssh2_userkey_loadpub(&ssh
->cfg
.keyfile
, NULL
,
4412 &s
->publickey_bloblen
);
4415 logeventf(ssh
, "Unable to use this key file (%s)",
4416 key_type_to_str(keytype
));
4417 msgbuf
= dupprintf("Unable to use key file \"%.150s\""
4419 filename_to_str(&ssh
->cfg
.keyfile
),
4420 key_type_to_str(keytype
));
4421 c_write_str(ssh
, msgbuf
);
4423 s
->publickey_blob
= NULL
;
4426 s
->publickey_blob
= NULL
;
4430 * Wait for the result of the last authentication request.
4433 crWaitUntilV(ispkt
);
4434 while (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_BANNER
) {
4438 * Don't show the banner if we're operating in
4439 * non-verbose non-interactive mode. (It's probably
4440 * a script, which means nobody will read the
4441 * banner _anyway_, and moreover the printing of
4442 * the banner will screw up processing on the
4443 * output of (say) plink.)
4445 if (flags
& (FLAG_VERBOSE
| FLAG_INTERACTIVE
)) {
4446 ssh2_pkt_getstring(ssh
, &banner
, &size
);
4448 c_write_untrusted(ssh
, banner
, size
);
4450 crWaitUntilV(ispkt
);
4452 if (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_SUCCESS
) {
4453 logevent("Access granted");
4454 s
->we_are_in
= TRUE
;
4458 if (s
->kbd_inter_running
&&
4459 ssh
->pktin
.type
== SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4461 * This is either a further set-of-prompts packet
4462 * in keyboard-interactive authentication, or it's
4463 * the same one and we came back here with `gotit'
4464 * set. In the former case, we must reset the
4465 * curr_prompt variable.
4469 } else if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_FAILURE
) {
4470 bombout((ssh
,"Strange packet received during authentication: type %d",
4478 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4479 * we can look at the string in it and know what we can
4480 * helpfully try next.
4482 if (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
) {
4485 ssh2_pkt_getstring(ssh
, &methods
, &methlen
);
4486 s
->kbd_inter_running
= FALSE
;
4487 if (!ssh2_pkt_getbool(ssh
)) {
4489 * We have received an unequivocal Access
4490 * Denied. This can translate to a variety of
4493 * - if we'd just tried "none" authentication,
4494 * it's not worth printing anything at all
4496 * - if we'd just tried a public key _offer_,
4497 * the message should be "Server refused our
4498 * key" (or no message at all if the key
4499 * came from Pageant)
4501 * - if we'd just tried anything else, the
4502 * message really should be "Access denied".
4504 * Additionally, if we'd just tried password
4505 * authentication, we should break out of this
4506 * whole loop so as to go back to the username
4509 if (s
->type
== AUTH_TYPE_NONE
) {
4511 } else if (s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
||
4512 s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_QUIET
) {
4513 if (s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
)
4514 c_write_str(ssh
, "Server refused our key\r\n");
4515 logevent("Server refused public key");
4516 } else if (s
->type
==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
) {
4517 /* server declined keyboard-interactive; ignore */
4519 c_write_str(ssh
, "Access denied\r\n");
4520 logevent("Access denied");
4521 if (s
->type
== AUTH_TYPE_PASSWORD
) {
4522 s
->we_are_in
= FALSE
;
4527 c_write_str(ssh
, "Further authentication required\r\n");
4528 logevent("Further authentication required");
4532 in_commasep_string("publickey", methods
, methlen
);
4534 in_commasep_string("password", methods
, methlen
);
4535 s
->can_keyb_inter
= ssh
->cfg
.try_ki_auth
&&
4536 in_commasep_string("keyboard-interactive", methods
, methlen
);
4540 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4543 * Most password/passphrase prompts will be
4544 * non-echoing, so we set this to 0 by default.
4545 * Exception is that some keyboard-interactive prompts
4546 * can be echoing, in which case we'll set this to 1.
4550 if (!s
->method
&& s
->can_pubkey
&&
4551 agent_exists() && !s
->tried_agent
) {
4553 * Attempt public-key authentication using Pageant.
4558 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4559 ssh
->pkt_ctx
|= SSH2_PKTCTX_PUBLICKEY
;
4561 s
->tried_agent
= TRUE
;
4563 logevent("Pageant is running. Requesting keys.");
4565 /* Request the keys held by the agent. */
4566 PUT_32BIT(s
->request
, 1);
4567 s
->request
[4] = SSH2_AGENTC_REQUEST_IDENTITIES
;
4568 agent_query(s
->request
, 5, &r
, &s
->responselen
);
4569 s
->response
= (unsigned char *) r
;
4570 if (s
->response
&& s
->responselen
>= 5 &&
4571 s
->response
[4] == SSH2_AGENT_IDENTITIES_ANSWER
) {
4572 s
->p
= s
->response
+ 5;
4573 s
->nkeys
= GET_32BIT(s
->p
);
4577 sprintf(buf
, "Pageant has %d SSH2 keys", s
->nkeys
);
4580 for (s
->keyi
= 0; s
->keyi
< s
->nkeys
; s
->keyi
++) {
4585 sprintf(buf
, "Trying Pageant key #%d", s
->keyi
);
4588 s
->pklen
= GET_32BIT(s
->p
);
4590 if (s
->publickey_blob
&&
4591 s
->pklen
== s
->publickey_bloblen
&&
4592 !memcmp(s
->p
, s
->publickey_blob
,
4593 s
->publickey_bloblen
)) {
4594 logevent("This key matches configured key file");
4595 s
->tried_pubkey_config
= 1;
4597 s
->pkblob
= (char *)s
->p
;
4599 s
->alglen
= GET_32BIT(s
->pkblob
);
4600 s
->alg
= s
->pkblob
+ 4;
4601 s
->commentlen
= GET_32BIT(s
->p
);
4603 s
->commentp
= (char *)s
->p
;
4604 s
->p
+= s
->commentlen
;
4605 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4606 ssh2_pkt_addstring(ssh
, s
->username
);
4607 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4608 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4609 ssh2_pkt_addbool(ssh
, FALSE
); /* no signature included */
4610 ssh2_pkt_addstring_start(ssh
);
4611 ssh2_pkt_addstring_data(ssh
, s
->alg
, s
->alglen
);
4612 ssh2_pkt_addstring_start(ssh
);
4613 ssh2_pkt_addstring_data(ssh
, s
->pkblob
, s
->pklen
);
4616 crWaitUntilV(ispkt
);
4617 if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4618 logevent("Key refused");
4622 if (flags
& FLAG_VERBOSE
) {
4623 c_write_str(ssh
, "Authenticating with "
4625 c_write(ssh
, s
->commentp
, s
->commentlen
);
4626 c_write_str(ssh
, "\" from agent\r\n");
4630 * Server is willing to accept the key.
4631 * Construct a SIGN_REQUEST.
4633 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4634 ssh2_pkt_addstring(ssh
, s
->username
);
4635 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4636 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4637 ssh2_pkt_addbool(ssh
, TRUE
);
4638 ssh2_pkt_addstring_start(ssh
);
4639 ssh2_pkt_addstring_data(ssh
, s
->alg
, s
->alglen
);
4640 ssh2_pkt_addstring_start(ssh
);
4641 ssh2_pkt_addstring_data(ssh
, s
->pkblob
, s
->pklen
);
4643 s
->siglen
= ssh
->pktout
.length
- 5 + 4 + 20;
4644 if (ssh
->remote_bugs
& BUG_SSH2_PK_SESSIONID
)
4646 s
->len
= 1; /* message type */
4647 s
->len
+= 4 + s
->pklen
; /* key blob */
4648 s
->len
+= 4 + s
->siglen
; /* data to sign */
4649 s
->len
+= 4; /* flags */
4650 s
->agentreq
= smalloc(4 + s
->len
);
4651 PUT_32BIT(s
->agentreq
, s
->len
);
4652 s
->q
= s
->agentreq
+ 4;
4653 *s
->q
++ = SSH2_AGENTC_SIGN_REQUEST
;
4654 PUT_32BIT(s
->q
, s
->pklen
);
4656 memcpy(s
->q
, s
->pkblob
, s
->pklen
);
4658 PUT_32BIT(s
->q
, s
->siglen
);
4660 /* Now the data to be signed... */
4661 if (!(ssh
->remote_bugs
& BUG_SSH2_PK_SESSIONID
)) {
4662 PUT_32BIT(s
->q
, 20);
4665 memcpy(s
->q
, ssh
->v2_session_id
, 20);
4667 memcpy(s
->q
, ssh
->pktout
.data
+ 5,
4668 ssh
->pktout
.length
- 5);
4669 s
->q
+= ssh
->pktout
.length
- 5;
4670 /* And finally the (zero) flags word. */
4672 agent_query(s
->agentreq
, s
->len
+ 4, &vret
, &s
->retlen
);
4676 if (s
->ret
[4] == SSH2_AGENT_SIGN_RESPONSE
) {
4677 logevent("Sending Pageant's response");
4678 ssh2_add_sigblob(ssh
, s
->pkblob
, s
->pklen
,
4680 GET_32BIT(s
->ret
+ 5));
4686 ("Pageant failed to answer challenge");
4696 if (!s
->method
&& s
->can_pubkey
&& s
->publickey_blob
4697 && !s
->tried_pubkey_config
) {
4698 unsigned char *pub_blob
;
4699 char *algorithm
, *comment
;
4702 s
->tried_pubkey_config
= TRUE
;
4704 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4705 ssh
->pkt_ctx
|= SSH2_PKTCTX_PUBLICKEY
;
4708 * Try the public key supplied in the configuration.
4710 * First, offer the public blob to see if the server is
4711 * willing to accept it.
4714 (unsigned char *)ssh2_userkey_loadpub(&ssh
->cfg
.keyfile
,
4718 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4719 ssh2_pkt_addstring(ssh
, s
->username
);
4720 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4721 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4722 ssh2_pkt_addbool(ssh
, FALSE
); /* no signature included */
4723 ssh2_pkt_addstring(ssh
, algorithm
);
4724 ssh2_pkt_addstring_start(ssh
);
4725 ssh2_pkt_addstring_data(ssh
, (char *)pub_blob
,
4728 logevent("Offered public key"); /* FIXME */
4730 crWaitUntilV(ispkt
);
4731 if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4733 s
->type
= AUTH_TYPE_PUBLICKEY_OFFER_LOUD
;
4734 continue; /* key refused; give up on it */
4737 logevent("Offer of public key accepted");
4739 * Actually attempt a serious authentication using
4742 if (ssh2_userkey_encrypted(&ssh
->cfg
.keyfile
, &comment
)) {
4743 sprintf(s
->pwprompt
,
4744 "Passphrase for key \"%.100s\": ",
4750 c_write_str(ssh
, "Authenticating with public key \"");
4751 c_write_str(ssh
, comment
);
4752 c_write_str(ssh
, "\"\r\n");
4753 s
->method
= AUTH_PUBLICKEY_FILE
;
4757 if (!s
->method
&& s
->can_keyb_inter
&& !s
->tried_keyb_inter
) {
4758 s
->method
= AUTH_KEYBOARD_INTERACTIVE
;
4759 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4760 s
->tried_keyb_inter
= TRUE
;
4762 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4763 ssh
->pkt_ctx
|= SSH2_PKTCTX_KBDINTER
;
4765 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4766 ssh2_pkt_addstring(ssh
, s
->username
);
4767 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4768 ssh2_pkt_addstring(ssh
, "keyboard-interactive"); /* method */
4769 ssh2_pkt_addstring(ssh
, ""); /* lang */
4770 ssh2_pkt_addstring(ssh
, "");
4773 crWaitUntilV(ispkt
);
4774 if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4775 if (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
)
4777 logevent("Keyboard-interactive authentication refused");
4778 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
;
4782 s
->kbd_inter_running
= TRUE
;
4786 if (s
->kbd_inter_running
) {
4787 s
->method
= AUTH_KEYBOARD_INTERACTIVE
;
4788 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4789 s
->tried_keyb_inter
= TRUE
;
4791 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4792 ssh
->pkt_ctx
|= SSH2_PKTCTX_KBDINTER
;
4794 if (s
->curr_prompt
== 0) {
4796 * We've got a fresh USERAUTH_INFO_REQUEST.
4797 * Display header data, and start going through
4800 char *name
, *inst
, *lang
;
4801 int name_len
, inst_len
, lang_len
;
4803 ssh2_pkt_getstring(ssh
, &name
, &name_len
);
4804 ssh2_pkt_getstring(ssh
, &inst
, &inst_len
);
4805 ssh2_pkt_getstring(ssh
, &lang
, &lang_len
);
4807 c_write_untrusted(ssh
, name
, name_len
);
4808 c_write_str(ssh
, "\r\n");
4811 c_write_untrusted(ssh
, inst
, inst_len
);
4812 c_write_str(ssh
, "\r\n");
4814 s
->num_prompts
= ssh2_pkt_getuint32(ssh
);
4818 * If there are prompts remaining in the packet,
4819 * display one and get a response.
4821 if (s
->curr_prompt
< s
->num_prompts
) {
4825 ssh2_pkt_getstring(ssh
, &prompt
, &prompt_len
);
4826 if (prompt_len
> 0) {
4827 strncpy(s
->pwprompt
, prompt
, sizeof(s
->pwprompt
));
4828 s
->pwprompt
[prompt_len
< sizeof(s
->pwprompt
) ?
4829 prompt_len
: sizeof(s
->pwprompt
)-1] = '\0';
4832 "<server failed to send prompt>: ");
4834 s
->echo
= ssh2_pkt_getbool(ssh
);
4840 if (!s
->method
&& s
->can_passwd
) {
4841 s
->method
= AUTH_PASSWORD
;
4842 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4843 ssh
->pkt_ctx
|= SSH2_PKTCTX_PASSWORD
;
4844 sprintf(s
->pwprompt
, "%.90s@%.90s's password: ", s
->username
,
4851 if (!ssh_get_line(s
->pwprompt
, s
->password
,
4852 sizeof(s
->password
), TRUE
)) {
4854 * get_line failed to get a password (for
4855 * example because one was supplied on the
4856 * command line which has already failed to
4859 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
4860 ssh2_pkt_adduint32(ssh
,SSH2_DISCONNECT_BY_APPLICATION
);
4861 ssh2_pkt_addstring(ssh
, "No more passwords available"
4863 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
4865 logevent("Unable to authenticate");
4866 connection_fatal(ssh
->frontend
,
4867 "Unable to authenticate");
4868 ssh
->state
= SSH_STATE_CLOSED
;
4872 int ret
; /* need not be saved across crReturn */
4873 c_write_untrusted(ssh
, s
->pwprompt
, strlen(s
->pwprompt
));
4876 setup_userpass_input(ssh
, s
->password
,
4877 sizeof(s
->password
), s
->echo
);
4879 crWaitUntilV(!ispkt
);
4880 ret
= process_userpass_input(ssh
, in
, inlen
);
4884 c_write_str(ssh
, "\r\n");
4888 if (s
->method
== AUTH_PUBLICKEY_FILE
) {
4890 * We have our passphrase. Now try the actual authentication.
4892 struct ssh2_userkey
*key
;
4894 key
= ssh2_load_userkey(&ssh
->cfg
.keyfile
, s
->password
);
4895 if (key
== SSH2_WRONG_PASSPHRASE
|| key
== NULL
) {
4896 if (key
== SSH2_WRONG_PASSPHRASE
) {
4897 c_write_str(ssh
, "Wrong passphrase\r\n");
4898 s
->tried_pubkey_config
= FALSE
;
4900 c_write_str(ssh
, "Unable to load private key\r\n");
4901 s
->tried_pubkey_config
= TRUE
;
4903 /* Send a spurious AUTH_NONE to return to the top. */
4904 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4905 ssh2_pkt_addstring(ssh
, s
->username
);
4906 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4907 ssh2_pkt_addstring(ssh
, "none"); /* method */
4909 s
->type
= AUTH_TYPE_NONE
;
4911 unsigned char *pkblob
, *sigblob
, *sigdata
;
4912 int pkblob_len
, sigblob_len
, sigdata_len
;
4916 * We have loaded the private key and the server
4917 * has announced that it's willing to accept it.
4918 * Hallelujah. Generate a signature and send it.
4920 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4921 ssh2_pkt_addstring(ssh
, s
->username
);
4922 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4923 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4924 ssh2_pkt_addbool(ssh
, TRUE
);
4925 ssh2_pkt_addstring(ssh
, key
->alg
->name
);
4926 pkblob
= key
->alg
->public_blob(key
->data
, &pkblob_len
);
4927 ssh2_pkt_addstring_start(ssh
);
4928 ssh2_pkt_addstring_data(ssh
, (char *)pkblob
, pkblob_len
);
4931 * The data to be signed is:
4935 * followed by everything so far placed in the
4938 sigdata_len
= ssh
->pktout
.length
- 5 + 4 + 20;
4939 if (ssh
->remote_bugs
& BUG_SSH2_PK_SESSIONID
)
4941 sigdata
= smalloc(sigdata_len
);
4943 if (!(ssh
->remote_bugs
& BUG_SSH2_PK_SESSIONID
)) {
4944 PUT_32BIT(sigdata
+p
, 20);
4947 memcpy(sigdata
+p
, ssh
->v2_session_id
, 20); p
+= 20;
4948 memcpy(sigdata
+p
, ssh
->pktout
.data
+ 5,
4949 ssh
->pktout
.length
- 5);
4950 p
+= ssh
->pktout
.length
- 5;
4951 assert(p
== sigdata_len
);
4952 sigblob
= key
->alg
->sign(key
->data
, (char *)sigdata
,
4953 sigdata_len
, &sigblob_len
);
4954 ssh2_add_sigblob(ssh
, pkblob
, pkblob_len
,
4955 sigblob
, sigblob_len
);
4961 s
->type
= AUTH_TYPE_PUBLICKEY
;
4963 } else if (s
->method
== AUTH_PASSWORD
) {
4965 * We send the password packet lumped tightly together with
4966 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4967 * string long enough to make the total length of the two
4968 * packets constant. This should ensure that a passive
4969 * listener doing traffic analyis can't work out the length
4972 * For this to work, we need an assumption about the
4973 * maximum length of the password packet. I think 256 is
4974 * pretty conservative. Anyone using a password longer than
4975 * that probably doesn't have much to worry about from
4976 * people who find out how long their password is!
4978 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4979 ssh2_pkt_addstring(ssh
, s
->username
);
4980 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4981 ssh2_pkt_addstring(ssh
, "password");
4982 ssh2_pkt_addbool(ssh
, FALSE
);
4983 ssh2_pkt_addstring(ssh
, s
->password
);
4984 memset(s
->password
, 0, sizeof(s
->password
));
4985 ssh2_pkt_defer(ssh
);
4987 * We'll include a string that's an exact multiple of the
4988 * cipher block size. If the cipher is NULL for some
4989 * reason, we don't do this trick at all because we gain
4992 if (ssh
->cscipher
) {
4995 stringlen
= (256 - ssh
->deferred_len
);
4996 stringlen
+= ssh
->cscipher
->blksize
- 1;
4997 stringlen
-= (stringlen
% ssh
->cscipher
->blksize
);
5000 * Temporarily disable actual compression,
5001 * so we can guarantee to get this string
5002 * exactly the length we want it. The
5003 * compression-disabling routine should
5004 * return an integer indicating how many
5005 * bytes we should adjust our string length
5009 ssh
->cscomp
->disable_compression(ssh
->cs_comp_ctx
);
5011 ssh2_pkt_init(ssh
, SSH2_MSG_IGNORE
);
5012 ssh2_pkt_addstring_start(ssh
);
5013 for (i
= 0; i
< stringlen
; i
++) {
5014 char c
= (char) random_byte();
5015 ssh2_pkt_addstring_data(ssh
, &c
, 1);
5017 ssh2_pkt_defer(ssh
);
5019 ssh_pkt_defersend(ssh
);
5020 logevent("Sent password");
5021 s
->type
= AUTH_TYPE_PASSWORD
;
5022 } else if (s
->method
== AUTH_KEYBOARD_INTERACTIVE
) {
5023 if (s
->curr_prompt
== 0) {
5024 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_INFO_RESPONSE
);
5025 ssh2_pkt_adduint32(ssh
, s
->num_prompts
);
5027 if (s
->need_pw
) { /* only add pw if we just got one! */
5028 ssh2_pkt_addstring(ssh
, s
->password
);
5029 memset(s
->password
, 0, sizeof(s
->password
));
5032 if (s
->curr_prompt
>= s
->num_prompts
) {
5036 * If there are prompts remaining, we set
5037 * `gotit' so that we won't attempt to get
5038 * another packet. Then we go back round the
5039 * loop and will end up retrieving another
5040 * prompt out of the existing packet. Funky or
5045 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
5047 c_write_str(ssh
, "No supported authentication methods"
5048 " left to try!\r\n");
5049 logevent("No supported authentications offered."
5051 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
5052 ssh2_pkt_adduint32(ssh
, SSH2_DISCONNECT_BY_APPLICATION
);
5053 ssh2_pkt_addstring(ssh
, "No supported authentication"
5054 " methods available");
5055 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5057 ssh
->state
= SSH_STATE_CLOSED
;
5061 } while (!s
->we_are_in
);
5064 * Now we're authenticated for the connection protocol. The
5065 * connection protocol will automatically have started at this
5066 * point; there's no need to send SERVICE_REQUEST.
5070 * So now create a channel with a session in it.
5072 ssh
->channels
= newtree234(ssh_channelcmp
);
5073 ssh
->mainchan
= smalloc(sizeof(struct ssh_channel
));
5074 ssh
->mainchan
->ssh
= ssh
;
5075 ssh
->mainchan
->localid
= alloc_channel_id(ssh
);
5076 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN
);
5077 ssh2_pkt_addstring(ssh
, "session");
5078 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->localid
);
5079 ssh
->mainchan
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5080 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->v
.v2
.locwindow
);/* our window size */
5081 ssh2_pkt_adduint32(ssh
, 0x4000UL
); /* our max pkt size */
5083 crWaitUntilV(ispkt
);
5084 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
5085 bombout((ssh
,"Server refused to open a session"));
5087 /* FIXME: error data comes back in FAILURE packet */
5089 if (ssh2_pkt_getuint32(ssh
) != ssh
->mainchan
->localid
) {
5090 bombout((ssh
,"Server's channel confirmation cited wrong channel"));
5093 ssh
->mainchan
->remoteid
= ssh2_pkt_getuint32(ssh
);
5094 ssh
->mainchan
->type
= CHAN_MAINSESSION
;
5095 ssh
->mainchan
->closes
= 0;
5096 ssh
->mainchan
->v
.v2
.remwindow
= ssh2_pkt_getuint32(ssh
);
5097 ssh
->mainchan
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32(ssh
);
5098 bufchain_init(&ssh
->mainchan
->v
.v2
.outbuffer
);
5099 add234(ssh
->channels
, ssh
->mainchan
);
5100 logevent("Opened channel for session");
5103 * Potentially enable X11 forwarding.
5105 if (ssh
->cfg
.x11_forward
) {
5106 char proto
[20], data
[64];
5107 logevent("Requesting X11 forwarding");
5108 ssh
->x11auth
= x11_invent_auth(proto
, sizeof(proto
),
5109 data
, sizeof(data
), ssh
->cfg
.x11_auth
);
5110 x11_get_real_auth(ssh
->x11auth
, ssh
->cfg
.x11_display
);
5111 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5112 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
5113 ssh2_pkt_addstring(ssh
, "x11-req");
5114 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5115 ssh2_pkt_addbool(ssh
, 0); /* many connections */
5116 ssh2_pkt_addstring(ssh
, proto
);
5117 ssh2_pkt_addstring(ssh
, data
);
5118 ssh2_pkt_adduint32(ssh
, x11_get_screen_number(ssh
->cfg
.x11_display
));
5122 crWaitUntilV(ispkt
);
5123 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5124 unsigned i
= ssh2_pkt_getuint32(ssh
);
5125 struct ssh_channel
*c
;
5126 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5128 continue; /* nonexistent channel */
5129 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5131 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5133 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5134 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5135 bombout((ssh
,"Unexpected response to X11 forwarding request:"
5136 " packet type %d", ssh
->pktin
.type
));
5139 logevent("X11 forwarding refused");
5141 logevent("X11 forwarding enabled");
5142 ssh
->X11_fwd_enabled
= TRUE
;
5147 * Enable port forwardings.
5152 int sport
,dport
,sserv
,dserv
;
5153 char sports
[256], dports
[256], saddr
[256], host
[256];
5155 ssh
->rportfwds
= newtree234(ssh_rportcmp_ssh2
);
5156 /* Add port forwardings. */
5157 ssh
->portfwd_strptr
= ssh
->cfg
.portfwd
;
5158 while (*ssh
->portfwd_strptr
) {
5159 type
= *ssh
->portfwd_strptr
++;
5162 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= '\t') {
5163 if (*ssh
->portfwd_strptr
== ':') {
5165 * We've seen a colon in the middle of the
5166 * source port number. This means that
5167 * everything we've seen until now is the
5168 * source _address_, so we'll move it into
5169 * saddr and start sports from the beginning
5172 ssh
->portfwd_strptr
++;
5174 strcpy(saddr
, sports
);
5177 if (n
< 255) sports
[n
++] = *ssh
->portfwd_strptr
++;
5180 if (*ssh
->portfwd_strptr
== '\t')
5181 ssh
->portfwd_strptr
++;
5183 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= ':') {
5184 if (n
< 255) host
[n
++] = *ssh
->portfwd_strptr
++;
5187 if (*ssh
->portfwd_strptr
== ':')
5188 ssh
->portfwd_strptr
++;
5190 while (*ssh
->portfwd_strptr
) {
5191 if (n
< 255) dports
[n
++] = *ssh
->portfwd_strptr
++;
5194 ssh
->portfwd_strptr
++;
5195 dport
= atoi(dports
);
5199 dport
= net_service_lookup(dports
);
5201 logeventf(ssh
, "Service lookup failed for destination"
5202 " port \"%s\"", dports
);
5205 sport
= atoi(sports
);
5209 sport
= net_service_lookup(sports
);
5211 logeventf(ssh
, "Service lookup failed for source"
5212 " port \"%s\"", sports
);
5215 if (sport
&& dport
) {
5217 pfd_addforward(host
, dport
, *saddr ? saddr
: NULL
,
5218 sport
, ssh
, &ssh
->cfg
);
5219 logeventf(ssh
, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5220 " forwarding to %s:%.*s%.*s%d%.*s",
5221 (int)(*saddr?
strlen(saddr
):0), *saddr?saddr
:NULL
,
5222 (int)(*saddr?
1:0), ":",
5223 (int)(sserv ?
strlen(sports
) : 0), sports
,
5224 sserv
, "(", sport
, sserv
, ")",
5226 (int)(dserv ?
strlen(dports
) : 0), dports
,
5227 dserv
, "(", dport
, dserv
, ")");
5229 struct ssh_rportfwd
*pf
;
5230 pf
= smalloc(sizeof(*pf
));
5231 strcpy(pf
->dhost
, host
);
5234 if (add234(ssh
->rportfwds
, pf
) != pf
) {
5235 logeventf(ssh
, "Duplicate remote port forwarding"
5236 " to %s:%d", host
, dport
);
5239 logeventf(ssh
, "Requesting remote port "
5240 "%.*s%.*s%.*s%.*s%d%.*s"
5241 " forward to %s:%.*s%.*s%d%.*s",
5242 (int)(*saddr?
strlen(saddr
):0),
5244 (int)(*saddr?
1:0), ":",
5245 (int)(sserv ?
strlen(sports
) : 0), sports
,
5246 sserv
, "(", sport
, sserv
, ")",
5248 (int)(dserv ?
strlen(dports
) : 0), dports
,
5249 dserv
, "(", dport
, dserv
, ")");
5250 ssh2_pkt_init(ssh
, SSH2_MSG_GLOBAL_REQUEST
);
5251 ssh2_pkt_addstring(ssh
, "tcpip-forward");
5252 ssh2_pkt_addbool(ssh
, 1);/* want reply */
5254 ssh2_pkt_addstring(ssh
, saddr
);
5255 if (ssh
->cfg
.rport_acceptall
)
5256 ssh2_pkt_addstring(ssh
, "0.0.0.0");
5258 ssh2_pkt_addstring(ssh
, "127.0.0.1");
5259 ssh2_pkt_adduint32(ssh
, sport
);
5263 crWaitUntilV(ispkt
);
5264 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5265 unsigned i
= ssh2_pkt_getuint32(ssh
);
5266 struct ssh_channel
*c
;
5267 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5269 continue;/* nonexistent channel */
5270 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5272 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5274 if (ssh
->pktin
.type
!= SSH2_MSG_REQUEST_SUCCESS
) {
5275 if (ssh
->pktin
.type
!= SSH2_MSG_REQUEST_FAILURE
) {
5276 bombout((ssh
,"Unexpected response to port "
5277 "forwarding request: packet type %d",
5281 logevent("Server refused this port forwarding");
5283 logevent("Remote port forwarding enabled");
5292 * Potentially enable agent forwarding.
5294 if (ssh
->cfg
.agentfwd
&& agent_exists()) {
5295 logevent("Requesting OpenSSH-style agent forwarding");
5296 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5297 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
5298 ssh2_pkt_addstring(ssh
, "auth-agent-req@openssh.com");
5299 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5303 crWaitUntilV(ispkt
);
5304 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5305 unsigned i
= ssh2_pkt_getuint32(ssh
);
5306 struct ssh_channel
*c
;
5307 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5309 continue; /* nonexistent channel */
5310 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5312 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5314 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5315 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5316 bombout((ssh
,"Unexpected response to agent forwarding request:"
5317 " packet type %d", ssh
->pktin
.type
));
5320 logevent("Agent forwarding refused");
5322 logevent("Agent forwarding enabled");
5323 ssh
->agentfwd_enabled
= TRUE
;
5328 * Now allocate a pty for the session.
5330 if (!ssh
->cfg
.nopty
) {
5331 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5332 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
); /* recipient channel */
5333 ssh2_pkt_addstring(ssh
, "pty-req");
5334 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5335 ssh2_pkt_addstring(ssh
, ssh
->cfg
.termtype
);
5336 ssh2_pkt_adduint32(ssh
, ssh
->term_width
);
5337 ssh2_pkt_adduint32(ssh
, ssh
->term_height
);
5338 ssh2_pkt_adduint32(ssh
, 0); /* pixel width */
5339 ssh2_pkt_adduint32(ssh
, 0); /* pixel height */
5340 ssh2_pkt_addstring_start(ssh
);
5341 ssh2_pkt_addstring_data(ssh
, "\0", 1); /* TTY_OP_END, no special options */
5343 ssh
->state
= SSH_STATE_INTERMED
;
5346 crWaitUntilV(ispkt
);
5347 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5348 unsigned i
= ssh2_pkt_getuint32(ssh
);
5349 struct ssh_channel
*c
;
5350 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5352 continue; /* nonexistent channel */
5353 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5355 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5357 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5358 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5359 bombout((ssh
,"Unexpected response to pty request:"
5360 " packet type %d", ssh
->pktin
.type
));
5363 c_write_str(ssh
, "Server refused to allocate pty\r\n");
5364 ssh
->editing
= ssh
->echoing
= 1;
5366 logevent("Allocated pty");
5369 ssh
->editing
= ssh
->echoing
= 1;
5373 * Start a shell or a remote command. We may have to attempt
5374 * this twice if the config data has provided a second choice
5381 if (ssh
->fallback_cmd
) {
5382 subsys
= ssh
->cfg
.ssh_subsys2
;
5383 cmd
= ssh
->cfg
.remote_cmd_ptr2
;
5385 subsys
= ssh
->cfg
.ssh_subsys
;
5386 cmd
= ssh
->cfg
.remote_cmd_ptr
;
5389 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5390 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
); /* recipient channel */
5392 ssh2_pkt_addstring(ssh
, "subsystem");
5393 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5394 ssh2_pkt_addstring(ssh
, cmd
);
5396 ssh2_pkt_addstring(ssh
, "exec");
5397 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5398 ssh2_pkt_addstring(ssh
, cmd
);
5400 ssh2_pkt_addstring(ssh
, "shell");
5401 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5405 crWaitUntilV(ispkt
);
5406 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5407 unsigned i
= ssh2_pkt_getuint32(ssh
);
5408 struct ssh_channel
*c
;
5409 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5411 continue; /* nonexistent channel */
5412 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5414 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5415 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5416 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5417 bombout((ssh
,"Unexpected response to shell/command request:"
5418 " packet type %d", ssh
->pktin
.type
));
5422 * We failed to start the command. If this is the
5423 * fallback command, we really are finished; if it's
5424 * not, and if the fallback command exists, try falling
5425 * back to it before complaining.
5427 if (!ssh
->fallback_cmd
&& ssh
->cfg
.remote_cmd_ptr2
!= NULL
) {
5428 logevent("Primary command failed; attempting fallback");
5429 ssh
->fallback_cmd
= TRUE
;
5432 bombout((ssh
,"Server refused to start a shell/command"));
5435 logevent("Started a shell/command");
5440 ssh
->state
= SSH_STATE_SESSION
;
5441 if (ssh
->size_needed
)
5442 ssh_size(ssh
, ssh
->term_width
, ssh
->term_height
);
5443 if (ssh
->eof_needed
)
5444 ssh_special(ssh
, TS_EOF
);
5450 ldisc_send(ssh
->ldisc
, NULL
, 0, 0);/* cause ldisc to notice changes */
5454 s
->try_send
= FALSE
;
5456 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
5457 ssh
->pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
5460 unsigned i
= ssh2_pkt_getuint32(ssh
);
5461 struct ssh_channel
*c
;
5462 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5464 continue; /* nonexistent channel */
5465 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
5466 ssh2_pkt_getuint32(ssh
) != SSH2_EXTENDED_DATA_STDERR
)
5467 continue; /* extended but not stderr */
5468 ssh2_pkt_getstring(ssh
, &data
, &length
);
5471 c
->v
.v2
.locwindow
-= length
;
5473 case CHAN_MAINSESSION
:
5475 from_backend(ssh
->frontend
, ssh
->pktin
.type
==
5476 SSH2_MSG_CHANNEL_EXTENDED_DATA
,
5480 bufsize
= x11_send(c
->u
.x11
.s
, data
, length
);
5483 bufsize
= pfd_send(c
->u
.pfd
.s
, data
, length
);
5486 while (length
> 0) {
5487 if (c
->u
.a
.lensofar
< 4) {
5488 int l
= min(4 - c
->u
.a
.lensofar
, length
);
5489 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
,
5493 c
->u
.a
.lensofar
+= l
;
5495 if (c
->u
.a
.lensofar
== 4) {
5497 4 + GET_32BIT(c
->u
.a
.msglen
);
5498 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
5499 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
5501 if (c
->u
.a
.lensofar
>= 4 && length
> 0) {
5503 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
5505 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
,
5509 c
->u
.a
.lensofar
+= l
;
5511 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
5512 void *reply
, *sentreply
;
5514 agent_query(c
->u
.a
.message
,
5515 c
->u
.a
.totallen
, &reply
,
5520 /* Fake SSH_AGENT_FAILURE. */
5521 sentreply
= "\0\0\0\1\5";
5524 ssh2_add_channel_data(c
, sentreply
, replylen
);
5528 sfree(c
->u
.a
.message
);
5529 c
->u
.a
.lensofar
= 0;
5536 * If we are not buffering too much data,
5537 * enlarge the window again at the remote side.
5539 if (bufsize
< OUR_V2_WINSIZE
)
5540 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
5542 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_EOF
) {
5543 unsigned i
= ssh2_pkt_getuint32(ssh
);
5544 struct ssh_channel
*c
;
5546 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5548 continue; /* nonexistent channel */
5550 if (c
->type
== CHAN_X11
) {
5552 * Remote EOF on an X11 channel means we should
5553 * wrap up and close the channel ourselves.
5555 x11_close(c
->u
.x11
.s
);
5557 } else if (c
->type
== CHAN_AGENT
) {
5559 } else if (c
->type
== CHAN_SOCKDATA
) {
5560 pfd_close(c
->u
.pfd
.s
);
5563 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_CLOSE
) {
5564 unsigned i
= ssh2_pkt_getuint32(ssh
);
5565 struct ssh_channel
*c
;
5567 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5568 if (!c
|| ((int)c
->remoteid
) == -1) {
5569 bombout((ssh
,"Received CHANNEL_CLOSE for %s channel %d\n",
5570 c ?
"half-open" : "nonexistent", i
));
5572 /* Do pre-close processing on the channel. */
5574 case CHAN_MAINSESSION
:
5575 break; /* nothing to see here, move along */
5577 if (c
->u
.x11
.s
!= NULL
)
5578 x11_close(c
->u
.x11
.s
);
5585 if (c
->u
.pfd
.s
!= NULL
)
5586 pfd_close(c
->u
.pfd
.s
);
5590 if (c
->closes
== 0) {
5591 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_CLOSE
);
5592 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5595 del234(ssh
->channels
, c
);
5596 bufchain_clear(&c
->v
.v2
.outbuffer
);
5600 * See if that was the last channel left open.
5602 if (count234(ssh
->channels
) == 0) {
5605 * We used to send SSH_MSG_DISCONNECT here,
5606 * because I'd believed that _every_ conforming
5607 * SSH2 connection had to end with a disconnect
5608 * being sent by at least one side; apparently
5609 * I was wrong and it's perfectly OK to
5610 * unceremoniously slam the connection shut
5611 * when you're done, and indeed OpenSSH feels
5612 * this is more polite than sending a
5613 * DISCONNECT. So now we don't.
5615 logevent("All channels closed. Disconnecting");
5616 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
5617 ssh2_pkt_adduint32(ssh
, SSH2_DISCONNECT_BY_APPLICATION
);
5618 ssh2_pkt_addstring(ssh
, "All open channels closed");
5619 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5622 ssh
->state
= SSH_STATE_CLOSED
;
5625 continue; /* remote sends close; ignore (FIXME) */
5626 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5627 unsigned i
= ssh2_pkt_getuint32(ssh
);
5628 struct ssh_channel
*c
;
5629 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5630 if (!c
|| c
->closes
)
5631 continue; /* nonexistent or closing channel */
5632 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5634 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
5635 unsigned i
= ssh2_pkt_getuint32(ssh
);
5636 struct ssh_channel
*c
;
5637 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5639 continue; /* nonexistent channel */
5640 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
5641 continue; /* dunno why they're confirming this */
5642 c
->remoteid
= ssh2_pkt_getuint32(ssh
);
5643 c
->type
= CHAN_SOCKDATA
;
5644 c
->v
.v2
.remwindow
= ssh2_pkt_getuint32(ssh
);
5645 c
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32(ssh
);
5647 pfd_confirm(c
->u
.pfd
.s
);
5650 * We have a pending close on this channel,
5651 * which we decided on before the server acked
5652 * the channel open. So now we know the
5653 * remoteid, we can close it again.
5655 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_CLOSE
);
5656 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5659 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_OPEN_FAILURE
) {
5660 unsigned i
= ssh2_pkt_getuint32(ssh
);
5661 struct ssh_channel
*c
;
5662 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5664 continue; /* nonexistent channel */
5665 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
5666 continue; /* dunno why they're failing this */
5668 logevent("Forwarded connection refused by server");
5670 pfd_close(c
->u
.pfd
.s
);
5672 del234(ssh
->channels
, c
);
5674 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_REQUEST
) {
5677 int typelen
, want_reply
;
5678 struct ssh_channel
*c
;
5680 localid
= ssh2_pkt_getuint32(ssh
);
5681 ssh2_pkt_getstring(ssh
, &type
, &typelen
);
5682 want_reply
= ssh2_pkt_getbool(ssh
);
5685 * First, check that the channel exists. Otherwise,
5686 * we can instantly disconnect with a rude message.
5688 c
= find234(ssh
->channels
, &localid
, ssh_channelfind
);
5691 sprintf(buf
, "Received channel request for nonexistent"
5692 " channel %d", localid
);
5694 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
5695 ssh2_pkt_adduint32(ssh
, SSH2_DISCONNECT_BY_APPLICATION
);
5696 ssh2_pkt_addstring(ssh
, buf
);
5697 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5699 connection_fatal("%s", buf
);
5700 ssh
->state
= SSH_STATE_CLOSED
;
5705 * Having got the channel number, we now look at
5706 * the request type string to see if it's something
5709 if (typelen
== 11 && !memcmp(type
, "exit-status", 11) &&
5710 c
== ssh
->mainchan
) {
5711 /* We recognise "exit-status" on the primary channel. */
5713 ssh
->exitcode
= ssh2_pkt_getuint32(ssh
);
5714 sprintf(buf
, "Server sent command exit status %d",
5718 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_SUCCESS
);
5719 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5724 * This is a channel request we don't know
5725 * about, so we now either ignore the request
5726 * or respond with CHANNEL_FAILURE, depending
5730 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_FAILURE
);
5731 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5735 } else if (ssh
->pktin
.type
== SSH2_MSG_GLOBAL_REQUEST
) {
5737 int typelen
, want_reply
;
5739 ssh2_pkt_getstring(ssh
, &type
, &typelen
);
5740 want_reply
= ssh2_pkt_getbool(ssh
);
5743 * We currently don't support any global requests
5744 * at all, so we either ignore the request or
5745 * respond with REQUEST_FAILURE, depending on
5749 ssh2_pkt_init(ssh
, SSH2_MSG_REQUEST_FAILURE
);
5752 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_OPEN
) {
5759 struct ssh_channel
*c
;
5760 unsigned remid
, winsize
, pktsize
;
5761 ssh2_pkt_getstring(ssh
, &type
, &typelen
);
5762 c
= smalloc(sizeof(struct ssh_channel
));
5765 remid
= ssh2_pkt_getuint32(ssh
);
5766 winsize
= ssh2_pkt_getuint32(ssh
);
5767 pktsize
= ssh2_pkt_getuint32(ssh
);
5768 ssh2_pkt_getstring(ssh
, &peeraddr
, &peeraddrlen
);
5769 port
= ssh2_pkt_getuint32(ssh
);
5771 if (typelen
== 3 && !memcmp(type
, "x11", 3)) {
5772 char *addrstr
= smalloc(peeraddrlen
+1);
5773 memcpy(addrstr
, peeraddr
, peeraddrlen
);
5774 peeraddr
[peeraddrlen
] = '\0';
5776 if (!ssh
->X11_fwd_enabled
)
5777 error
= "X11 forwarding is not enabled";
5778 else if (x11_init(&c
->u
.x11
.s
, ssh
->cfg
.x11_display
, c
,
5779 ssh
->x11auth
, addrstr
, port
,
5780 &ssh
->cfg
) != NULL
) {
5781 error
= "Unable to open an X11 connection";
5787 } else if (typelen
== 15 &&
5788 !memcmp(type
, "forwarded-tcpip", 15)) {
5789 struct ssh_rportfwd pf
, *realpf
;
5792 ssh2_pkt_getstring(ssh
, &dummy
, &dummylen
);/* skip address */
5793 pf
.sport
= ssh2_pkt_getuint32(ssh
);
5794 realpf
= find234(ssh
->rportfwds
, &pf
, NULL
);
5795 if (realpf
== NULL
) {
5796 error
= "Remote port is not recognised";
5798 char *e
= pfd_newconnect(&c
->u
.pfd
.s
, realpf
->dhost
,
5799 realpf
->dport
, c
, &ssh
->cfg
);
5800 logeventf(ssh
, "Received remote port open request"
5801 " for %s:%d", realpf
->dhost
, realpf
->dport
);
5803 logeventf(ssh
, "Port open failed: %s", e
);
5804 error
= "Port open failed";
5806 logevent("Forwarded port opened successfully");
5807 c
->type
= CHAN_SOCKDATA
;
5810 } else if (typelen
== 22 &&
5811 !memcmp(type
, "auth-agent@openssh.com", 3)) {
5812 if (!ssh
->agentfwd_enabled
)
5813 error
= "Agent forwarding is not enabled";
5815 c
->type
= CHAN_AGENT
; /* identify channel type */
5816 c
->u
.a
.lensofar
= 0;
5819 error
= "Unsupported channel type requested";
5822 c
->remoteid
= remid
;
5824 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN_FAILURE
);
5825 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5826 ssh2_pkt_adduint32(ssh
, SSH2_OPEN_CONNECT_FAILED
);
5827 ssh2_pkt_addstring(ssh
, error
);
5828 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5832 c
->localid
= alloc_channel_id(ssh
);
5834 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5835 c
->v
.v2
.remwindow
= winsize
;
5836 c
->v
.v2
.remmaxpkt
= pktsize
;
5837 bufchain_init(&c
->v
.v2
.outbuffer
);
5838 add234(ssh
->channels
, c
);
5839 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
5840 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5841 ssh2_pkt_adduint32(ssh
, c
->localid
);
5842 ssh2_pkt_adduint32(ssh
, c
->v
.v2
.locwindow
);
5843 ssh2_pkt_adduint32(ssh
, 0x4000UL
); /* our max pkt size */
5847 bombout((ssh
,"Strange packet received: type %d", ssh
->pktin
.type
));
5852 * We have spare data. Add it to the channel buffer.
5854 ssh2_add_channel_data(ssh
->mainchan
, (char *)in
, inlen
);
5859 struct ssh_channel
*c
;
5861 * Try to send data on all channels if we can.
5863 for (i
= 0; NULL
!= (c
= index234(ssh
->channels
, i
)); i
++) {
5866 continue; /* don't send on closing channels */
5867 bufsize
= ssh2_try_send(c
);
5870 case CHAN_MAINSESSION
:
5871 /* stdin need not receive an unthrottle
5872 * notification since it will be polled */
5875 x11_unthrottle(c
->u
.x11
.s
);
5878 /* agent sockets are request/response and need no
5879 * buffer management */
5882 pfd_unthrottle(c
->u
.pfd
.s
);
5894 * Handle the top-level SSH2 protocol.
5896 static void ssh2_protocol(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
5898 if (do_ssh2_transport(ssh
, in
, inlen
, ispkt
) == 0)
5900 do_ssh2_authconn(ssh
, in
, inlen
, ispkt
);
5904 * Called to set up the connection.
5906 * Returns an error message, or NULL on success.
5908 static char *ssh_init(void *frontend_handle
, void **backend_handle
,
5910 char *host
, int port
, char **realhost
, int nodelay
)
5915 ssh
= smalloc(sizeof(*ssh
));
5916 ssh
->cfg
= *cfg
; /* STRUCTURE COPY */
5919 ssh
->v1_cipher_ctx
= NULL
;
5920 ssh
->crcda_ctx
= NULL
;
5921 ssh
->cscipher
= NULL
;
5922 ssh
->cs_cipher_ctx
= NULL
;
5923 ssh
->sccipher
= NULL
;
5924 ssh
->sc_cipher_ctx
= NULL
;
5926 ssh
->cs_mac_ctx
= NULL
;
5928 ssh
->sc_mac_ctx
= NULL
;
5930 ssh
->cs_comp_ctx
= NULL
;
5932 ssh
->sc_comp_ctx
= NULL
;
5934 ssh
->kex_ctx
= NULL
;
5935 ssh
->hostkey
= NULL
;
5937 ssh
->state
= SSH_STATE_PREPACKET
;
5938 ssh
->size_needed
= FALSE
;
5939 ssh
->eof_needed
= FALSE
;
5943 static const struct Packet empty
= { 0, 0, NULL
, NULL
, 0 };
5944 ssh
->pktin
= ssh
->pktout
= empty
;
5946 ssh
->deferred_send_data
= NULL
;
5947 ssh
->deferred_len
= 0;
5948 ssh
->deferred_size
= 0;
5949 ssh
->fallback_cmd
= 0;
5951 ssh
->x11auth
= NULL
;
5952 ssh
->v1_compressing
= FALSE
;
5953 ssh
->v2_outgoing_sequence
= 0;
5954 ssh
->ssh1_rdpkt_crstate
= 0;
5955 ssh
->ssh2_rdpkt_crstate
= 0;
5956 ssh
->do_ssh_init_crstate
= 0;
5957 ssh
->ssh_gotdata_crstate
= 0;
5958 ssh
->ssh1_protocol_crstate
= 0;
5959 ssh
->do_ssh1_login_crstate
= 0;
5960 ssh
->do_ssh2_transport_crstate
= 0;
5961 ssh
->do_ssh2_authconn_crstate
= 0;
5962 ssh
->do_ssh_init_state
= NULL
;
5963 ssh
->do_ssh1_login_state
= NULL
;
5964 ssh
->do_ssh2_transport_state
= NULL
;
5965 ssh
->do_ssh2_authconn_state
= NULL
;
5966 ssh
->mainchan
= NULL
;
5967 ssh
->throttled_all
= 0;
5968 ssh
->v1_stdout_throttling
= 0;
5970 *backend_handle
= ssh
;
5973 if (crypto_startup() == 0)
5974 return "Microsoft high encryption pack not installed!";
5977 ssh
->frontend
= frontend_handle
;
5978 ssh
->term_width
= ssh
->cfg
.width
;
5979 ssh
->term_height
= ssh
->cfg
.height
;
5981 ssh
->channels
= NULL
;
5982 ssh
->rportfwds
= NULL
;
5987 ssh
->v1_throttle_count
= 0;
5988 ssh
->overall_bufsize
= 0;
5989 ssh
->fallback_cmd
= 0;
5991 ssh
->protocol
= NULL
;
5993 p
= connect_to_host(ssh
, host
, port
, realhost
, nodelay
);
6000 static void ssh_free(void *handle
)
6002 Ssh ssh
= (Ssh
) handle
;
6003 struct ssh_channel
*c
;
6004 struct ssh_rportfwd
*pf
;
6006 if (ssh
->v1_cipher_ctx
)
6007 ssh
->cipher
->free_context(ssh
->v1_cipher_ctx
);
6008 if (ssh
->cs_cipher_ctx
)
6009 ssh
->cscipher
->free_context(ssh
->cs_cipher_ctx
);
6010 if (ssh
->sc_cipher_ctx
)
6011 ssh
->sccipher
->free_context(ssh
->sc_cipher_ctx
);
6012 if (ssh
->cs_mac_ctx
)
6013 ssh
->csmac
->free_context(ssh
->cs_mac_ctx
);
6014 if (ssh
->sc_mac_ctx
)
6015 ssh
->scmac
->free_context(ssh
->sc_mac_ctx
);
6016 if (ssh
->cs_comp_ctx
)
6017 ssh
->cscomp
->compress_cleanup(ssh
->cs_comp_ctx
);
6018 if (ssh
->sc_comp_ctx
)
6019 ssh
->sccomp
->compress_cleanup(ssh
->sc_comp_ctx
);
6021 dh_cleanup(ssh
->kex_ctx
);
6022 sfree(ssh
->savedhost
);
6024 if (ssh
->channels
) {
6025 while ((c
= delpos234(ssh
->channels
, 0)) != NULL
) {
6028 if (c
->u
.x11
.s
!= NULL
)
6029 x11_close(c
->u
.x11
.s
);
6032 if (c
->u
.pfd
.s
!= NULL
)
6033 pfd_close(c
->u
.pfd
.s
);
6038 freetree234(ssh
->channels
);
6041 if (ssh
->rportfwds
) {
6042 while ((pf
= delpos234(ssh
->rportfwds
, 0)) != NULL
)
6044 freetree234(ssh
->rportfwds
);
6046 sfree(ssh
->deferred_send_data
);
6048 x11_free_auth(ssh
->x11auth
);
6049 sfree(ssh
->do_ssh_init_state
);
6050 sfree(ssh
->do_ssh1_login_state
);
6051 sfree(ssh
->do_ssh2_transport_state
);
6052 sfree(ssh
->do_ssh2_authconn_state
);
6060 * Reconfigure the SSH backend.
6062 * Currently, this function does nothing very useful. In future,
6063 * however, we could do some handy things with it. For example, we
6064 * could make the port forwarding configurer active in the Change
6065 * Settings box, and this routine could close down existing
6066 * forwardings and open up new ones in response to changes.
6068 static void ssh_reconfig(void *handle
, Config
*cfg
)
6070 Ssh ssh
= (Ssh
) handle
;
6071 ssh
->cfg
= *cfg
; /* STRUCTURE COPY */
6075 * Called to send data down the Telnet connection.
6077 static int ssh_send(void *handle
, char *buf
, int len
)
6079 Ssh ssh
= (Ssh
) handle
;
6081 if (ssh
== NULL
|| ssh
->s
== NULL
|| ssh
->protocol
== NULL
)
6084 ssh
->protocol(ssh
, (unsigned char *)buf
, len
, 0);
6086 return ssh_sendbuffer(ssh
);
6090 * Called to query the current amount of buffered stdin data.
6092 static int ssh_sendbuffer(void *handle
)
6094 Ssh ssh
= (Ssh
) handle
;
6097 if (ssh
== NULL
|| ssh
->s
== NULL
|| ssh
->protocol
== NULL
)
6101 * If the SSH socket itself has backed up, add the total backup
6102 * size on that to any individual buffer on the stdin channel.
6105 if (ssh
->throttled_all
)
6106 override_value
= ssh
->overall_bufsize
;
6108 if (ssh
->version
== 1) {
6109 return override_value
;
6110 } else if (ssh
->version
== 2) {
6111 if (!ssh
->mainchan
|| ssh
->mainchan
->closes
> 0)
6112 return override_value
;
6114 return (override_value
+
6115 bufchain_size(&ssh
->mainchan
->v
.v2
.outbuffer
));
6122 * Called to set the size of the window from SSH's POV.
6124 static void ssh_size(void *handle
, int width
, int height
)
6126 Ssh ssh
= (Ssh
) handle
;
6128 ssh
->term_width
= width
;
6129 ssh
->term_height
= height
;
6131 switch (ssh
->state
) {
6132 case SSH_STATE_BEFORE_SIZE
:
6133 case SSH_STATE_PREPACKET
:
6134 case SSH_STATE_CLOSED
:
6135 break; /* do nothing */
6136 case SSH_STATE_INTERMED
:
6137 ssh
->size_needed
= TRUE
; /* buffer for later */
6139 case SSH_STATE_SESSION
:
6140 if (!ssh
->cfg
.nopty
) {
6141 if (ssh
->version
== 1) {
6142 send_packet(ssh
, SSH1_CMSG_WINDOW_SIZE
,
6143 PKT_INT
, ssh
->term_height
,
6144 PKT_INT
, ssh
->term_width
,
6145 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
6147 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
6148 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
6149 ssh2_pkt_addstring(ssh
, "window-change");
6150 ssh2_pkt_addbool(ssh
, 0);
6151 ssh2_pkt_adduint32(ssh
, ssh
->term_width
);
6152 ssh2_pkt_adduint32(ssh
, ssh
->term_height
);
6153 ssh2_pkt_adduint32(ssh
, 0);
6154 ssh2_pkt_adduint32(ssh
, 0);
6163 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6164 * can send an EOF and collect resulting output (e.g. `plink
6167 static void ssh_special(void *handle
, Telnet_Special code
)
6169 Ssh ssh
= (Ssh
) handle
;
6171 if (code
== TS_EOF
) {
6172 if (ssh
->state
!= SSH_STATE_SESSION
) {
6174 * Buffer the EOF in case we are pre-SESSION, so we can
6175 * send it as soon as we reach SESSION.
6178 ssh
->eof_needed
= TRUE
;
6181 if (ssh
->version
== 1) {
6182 send_packet(ssh
, SSH1_CMSG_EOF
, PKT_END
);
6184 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_EOF
);
6185 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
6188 logevent("Sent EOF message");
6189 } else if (code
== TS_PING
) {
6190 if (ssh
->state
== SSH_STATE_CLOSED
6191 || ssh
->state
== SSH_STATE_PREPACKET
) return;
6192 if (ssh
->version
== 1) {
6193 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
))
6194 send_packet(ssh
, SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
6196 ssh2_pkt_init(ssh
, SSH2_MSG_IGNORE
);
6197 ssh2_pkt_addstring_start(ssh
);
6205 void *new_sock_channel(void *handle
, Socket s
)
6207 Ssh ssh
= (Ssh
) handle
;
6208 struct ssh_channel
*c
;
6209 c
= smalloc(sizeof(struct ssh_channel
));
6213 c
->remoteid
= -1; /* to be set when open confirmed */
6214 c
->localid
= alloc_channel_id(ssh
);
6216 c
->type
= CHAN_SOCKDATA_DORMANT
;/* identify channel type */
6218 bufchain_init(&c
->v
.v2
.outbuffer
);
6219 add234(ssh
->channels
, c
);
6225 * This is called when stdout/stderr (the entity to which
6226 * from_backend sends data) manages to clear some backlog.
6228 static void ssh_unthrottle(void *handle
, int bufsize
)
6230 Ssh ssh
= (Ssh
) handle
;
6231 if (ssh
->version
== 1) {
6232 if (ssh
->v1_stdout_throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
6233 ssh
->v1_stdout_throttling
= 0;
6234 ssh1_throttle(ssh
, -1);
6237 if (ssh
->mainchan
&& ssh
->mainchan
->closes
== 0)
6238 ssh2_set_window(ssh
->mainchan
, OUR_V2_WINSIZE
- bufsize
);
6242 void ssh_send_port_open(void *channel
, char *hostname
, int port
, char *org
)
6244 struct ssh_channel
*c
= (struct ssh_channel
*)channel
;
6247 logeventf(ssh
, "Opening forwarded connection to %s:%d", hostname
, port
);
6249 if (ssh
->version
== 1) {
6250 send_packet(ssh
, SSH1_MSG_PORT_OPEN
,
6251 PKT_INT
, c
->localid
,
6254 //PKT_STR, <org:orgport>,
6257 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN
);
6258 ssh2_pkt_addstring(ssh
, "direct-tcpip");
6259 ssh2_pkt_adduint32(ssh
, c
->localid
);
6260 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
6261 ssh2_pkt_adduint32(ssh
, c
->v
.v2
.locwindow
);/* our window size */
6262 ssh2_pkt_adduint32(ssh
, 0x4000UL
); /* our max pkt size */
6263 ssh2_pkt_addstring(ssh
, hostname
);
6264 ssh2_pkt_adduint32(ssh
, port
);
6266 * We make up values for the originator data; partly it's
6267 * too much hassle to keep track, and partly I'm not
6268 * convinced the server should be told details like that
6269 * about my local network configuration.
6271 ssh2_pkt_addstring(ssh
, "client-side-connection");
6272 ssh2_pkt_adduint32(ssh
, 0);
6278 static Socket
ssh_socket(void *handle
)
6280 Ssh ssh
= (Ssh
) handle
;
6284 static int ssh_sendok(void *handle
)
6286 Ssh ssh
= (Ssh
) handle
;
6287 return ssh
->send_ok
;
6290 static int ssh_ldisc(void *handle
, int option
)
6292 Ssh ssh
= (Ssh
) handle
;
6293 if (option
== LD_ECHO
)
6294 return ssh
->echoing
;
6295 if (option
== LD_EDIT
)
6296 return ssh
->editing
;
6300 static void ssh_provide_ldisc(void *handle
, void *ldisc
)
6302 Ssh ssh
= (Ssh
) handle
;
6306 static void ssh_provide_logctx(void *handle
, void *logctx
)
6308 Ssh ssh
= (Ssh
) handle
;
6309 ssh
->logctx
= logctx
;
6312 static int ssh_return_exitcode(void *handle
)
6314 Ssh ssh
= (Ssh
) handle
;
6315 return ssh
->exitcode
;
6319 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6320 * that fails. This variable is the means by which scp.c can reach
6321 * into the SSH code and find out which one it got.
6323 extern int ssh_fallback_cmd(void *handle
)
6325 Ssh ssh
= (Ssh
) handle
;
6326 return ssh
->fallback_cmd
;
6329 Backend ssh_backend
= {
6338 ssh_return_exitcode
,