18 #define logevent(s) { logevent(s); \
19 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
20 { fprintf(stderr, "%s\n", s); fflush(stderr); } }
22 /* logevent, only printf-formatted. */
23 void logeventf(char *fmt
, ...)
29 vsprintf(stuff
, fmt
, ap
);
34 #define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \
35 (s ? sk_close(s), s = NULL : 0), \
36 logeventf msg, connection_fatal msg )
38 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
39 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
40 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
41 #define SSH1_CMSG_USER 4 /* 0x4 */
42 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
43 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
44 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
45 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
46 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
47 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
48 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
49 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
50 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
51 #define SSH1_SMSG_FAILURE 15 /* 0xf */
52 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
53 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
54 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
55 #define SSH1_CMSG_EOF 19 /* 0x13 */
56 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
57 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
58 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
59 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
60 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
61 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
62 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
63 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
64 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
65 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
66 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
67 #define SSH1_MSG_IGNORE 32 /* 0x20 */
68 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
69 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
70 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
71 #define SSH1_MSG_DEBUG 36 /* 0x24 */
72 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
73 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
74 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
75 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
76 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
77 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
78 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
80 #define SSH1_AUTH_TIS 5 /* 0x5 */
81 #define SSH1_AUTH_CCARD 16 /* 0x10 */
83 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
84 /* Mask for protoflags we will echo back to server if seen */
85 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
87 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
88 #define SSH2_MSG_IGNORE 2 /* 0x2 */
89 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
90 #define SSH2_MSG_DEBUG 4 /* 0x4 */
91 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
92 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
93 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
94 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
95 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
96 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
97 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
98 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
99 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
100 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
101 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
102 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
103 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
104 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
105 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
106 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
107 #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
108 #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
109 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
110 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
111 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
112 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
113 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
114 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
115 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
116 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
117 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
118 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
119 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
120 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
121 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
122 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
125 * Packet type contexts, so that ssh2_pkt_type can correctly decode
126 * the ambiguous type numbers back into the correct type strings.
128 #define SSH2_PKTCTX_DHGROUP1 0x0001
129 #define SSH2_PKTCTX_DHGEX 0x0002
130 #define SSH2_PKTCTX_PUBLICKEY 0x0010
131 #define SSH2_PKTCTX_PASSWORD 0x0020
132 #define SSH2_PKTCTX_KBDINTER 0x0040
133 #define SSH2_PKTCTX_AUTH_MASK 0x00F0
135 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
136 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
137 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
138 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
139 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
140 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
141 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
142 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
143 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
144 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
145 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
146 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
147 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
148 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
149 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
151 static const char *const ssh2_disconnect_reasons
[] = {
153 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
154 "SSH_DISCONNECT_PROTOCOL_ERROR",
155 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
156 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
157 "SSH_DISCONNECT_MAC_ERROR",
158 "SSH_DISCONNECT_COMPRESSION_ERROR",
159 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
160 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
161 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
162 "SSH_DISCONNECT_CONNECTION_LOST",
163 "SSH_DISCONNECT_BY_APPLICATION",
164 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
165 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
166 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
167 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
170 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
171 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
172 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
173 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
175 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
178 * Various remote-bug flags.
180 #define BUG_CHOKES_ON_SSH1_IGNORE 1
181 #define BUG_SSH2_HMAC 2
182 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
183 #define BUG_CHOKES_ON_RSA 8
185 static int ssh_pkt_ctx
= 0;
187 #define translate(x) if (type == x) return #x
188 #define translatec(x,ctx) if (type == x && (ssh_pkt_ctx & ctx)) return #x
189 char *ssh1_pkt_type(int type
)
191 translate(SSH1_MSG_DISCONNECT
);
192 translate(SSH1_SMSG_PUBLIC_KEY
);
193 translate(SSH1_CMSG_SESSION_KEY
);
194 translate(SSH1_CMSG_USER
);
195 translate(SSH1_CMSG_AUTH_RSA
);
196 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE
);
197 translate(SSH1_CMSG_AUTH_RSA_RESPONSE
);
198 translate(SSH1_CMSG_AUTH_PASSWORD
);
199 translate(SSH1_CMSG_REQUEST_PTY
);
200 translate(SSH1_CMSG_WINDOW_SIZE
);
201 translate(SSH1_CMSG_EXEC_SHELL
);
202 translate(SSH1_CMSG_EXEC_CMD
);
203 translate(SSH1_SMSG_SUCCESS
);
204 translate(SSH1_SMSG_FAILURE
);
205 translate(SSH1_CMSG_STDIN_DATA
);
206 translate(SSH1_SMSG_STDOUT_DATA
);
207 translate(SSH1_SMSG_STDERR_DATA
);
208 translate(SSH1_CMSG_EOF
);
209 translate(SSH1_SMSG_EXIT_STATUS
);
210 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
);
211 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE
);
212 translate(SSH1_MSG_CHANNEL_DATA
);
213 translate(SSH1_MSG_CHANNEL_CLOSE
);
214 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
);
215 translate(SSH1_SMSG_X11_OPEN
);
216 translate(SSH1_CMSG_PORT_FORWARD_REQUEST
);
217 translate(SSH1_MSG_PORT_OPEN
);
218 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING
);
219 translate(SSH1_SMSG_AGENT_OPEN
);
220 translate(SSH1_MSG_IGNORE
);
221 translate(SSH1_CMSG_EXIT_CONFIRMATION
);
222 translate(SSH1_CMSG_X11_REQUEST_FORWARDING
);
223 translate(SSH1_CMSG_AUTH_RHOSTS_RSA
);
224 translate(SSH1_MSG_DEBUG
);
225 translate(SSH1_CMSG_REQUEST_COMPRESSION
);
226 translate(SSH1_CMSG_AUTH_TIS
);
227 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE
);
228 translate(SSH1_CMSG_AUTH_TIS_RESPONSE
);
229 translate(SSH1_CMSG_AUTH_CCARD
);
230 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE
);
231 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE
);
234 char *ssh2_pkt_type(int type
)
236 translate(SSH2_MSG_DISCONNECT
);
237 translate(SSH2_MSG_IGNORE
);
238 translate(SSH2_MSG_UNIMPLEMENTED
);
239 translate(SSH2_MSG_DEBUG
);
240 translate(SSH2_MSG_SERVICE_REQUEST
);
241 translate(SSH2_MSG_SERVICE_ACCEPT
);
242 translate(SSH2_MSG_KEXINIT
);
243 translate(SSH2_MSG_NEWKEYS
);
244 translatec(SSH2_MSG_KEXDH_INIT
, SSH2_PKTCTX_DHGROUP1
);
245 translatec(SSH2_MSG_KEXDH_REPLY
, SSH2_PKTCTX_DHGROUP1
);
246 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST
, SSH2_PKTCTX_DHGEX
);
247 translatec(SSH2_MSG_KEX_DH_GEX_GROUP
, SSH2_PKTCTX_DHGEX
);
248 translatec(SSH2_MSG_KEX_DH_GEX_INIT
, SSH2_PKTCTX_DHGEX
);
249 translatec(SSH2_MSG_KEX_DH_GEX_REPLY
, SSH2_PKTCTX_DHGEX
);
250 translate(SSH2_MSG_USERAUTH_REQUEST
);
251 translate(SSH2_MSG_USERAUTH_FAILURE
);
252 translate(SSH2_MSG_USERAUTH_SUCCESS
);
253 translate(SSH2_MSG_USERAUTH_BANNER
);
254 translatec(SSH2_MSG_USERAUTH_PK_OK
, SSH2_PKTCTX_PUBLICKEY
);
255 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ
, SSH2_PKTCTX_PASSWORD
);
256 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST
, SSH2_PKTCTX_KBDINTER
);
257 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE
, SSH2_PKTCTX_KBDINTER
);
258 translate(SSH2_MSG_GLOBAL_REQUEST
);
259 translate(SSH2_MSG_REQUEST_SUCCESS
);
260 translate(SSH2_MSG_REQUEST_FAILURE
);
261 translate(SSH2_MSG_CHANNEL_OPEN
);
262 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
263 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE
);
264 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
265 translate(SSH2_MSG_CHANNEL_DATA
);
266 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA
);
267 translate(SSH2_MSG_CHANNEL_EOF
);
268 translate(SSH2_MSG_CHANNEL_CLOSE
);
269 translate(SSH2_MSG_CHANNEL_REQUEST
);
270 translate(SSH2_MSG_CHANNEL_SUCCESS
);
271 translate(SSH2_MSG_CHANNEL_FAILURE
);
277 #define GET_32BIT(cp) \
278 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
279 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
280 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
281 ((unsigned long)(unsigned char)(cp)[3]))
283 #define PUT_32BIT(cp, value) { \
284 (cp)[0] = (unsigned char)((value) >> 24); \
285 (cp)[1] = (unsigned char)((value) >> 16); \
286 (cp)[2] = (unsigned char)((value) >> 8); \
287 (cp)[3] = (unsigned char)(value); }
289 enum { PKT_END
, PKT_INT
, PKT_CHAR
, PKT_DATA
, PKT_STR
, PKT_BIGNUM
};
291 /* Coroutine mechanics for the sillier bits of the code */
292 #define crBegin1 static int crLine = 0;
293 #define crBegin2 switch(crLine) { case 0:;
294 #define crBegin crBegin1; crBegin2;
295 #define crFinish(z) } crLine = 0; return (z)
296 #define crFinishV } crLine = 0; return
297 #define crReturn(z) \
299 crLine=__LINE__; return (z); case __LINE__:;\
303 crLine=__LINE__; return; case __LINE__:;\
305 #define crStop(z) do{ crLine = 0; return (z); }while(0)
306 #define crStopV do{ crLine = 0; return; }while(0)
307 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
308 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
310 extern char *x11_init(Socket
*, char *, void *);
311 extern void x11_close(Socket
);
312 extern int x11_send(Socket
, char *, int);
313 extern void x11_invent_auth(char *, int, char *, int);
314 extern void x11_unthrottle(Socket s
);
315 extern void x11_override_throttle(Socket s
, int enable
);
317 extern char *pfd_newconnect(Socket
* s
, char *hostname
, int port
, void *c
);
318 extern char *pfd_addforward(char *desthost
, int destport
, int port
);
319 extern void pfd_close(Socket s
);
320 extern int pfd_send(Socket s
, char *data
, int len
);
321 extern void pfd_confirm(Socket s
);
322 extern void pfd_unthrottle(Socket s
);
323 extern void pfd_override_throttle(Socket s
, int enable
);
325 static void ssh2_pkt_init(int pkt_type
);
326 static void ssh2_pkt_addbool(unsigned char value
);
327 static void ssh2_pkt_adduint32(unsigned long value
);
328 static void ssh2_pkt_addstring_start(void);
329 static void ssh2_pkt_addstring_str(char *data
);
330 static void ssh2_pkt_addstring_data(char *data
, int len
);
331 static void ssh2_pkt_addstring(char *data
);
332 static char *ssh2_mpint_fmt(Bignum b
, int *len
);
333 static void ssh2_pkt_addmp(Bignum b
);
334 static int ssh2_pkt_construct(void);
335 static void ssh2_pkt_send(void);
338 * Buffer management constants. There are several of these for
339 * various different purposes:
341 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
342 * on a local data stream before we throttle the whole SSH
343 * connection (in SSH1 only). Throttling the whole connection is
344 * pretty drastic so we set this high in the hope it won't
347 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
348 * on the SSH connection itself before we defensively throttle
349 * _all_ local data streams. This is pretty drastic too (though
350 * thankfully unlikely in SSH2 since the window mechanism should
351 * ensure that the server never has any need to throttle its end
352 * of the connection), so we set this high as well.
354 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
358 #define SSH1_BUFFER_LIMIT 32768
359 #define SSH_MAX_BACKLOG 32768
360 #define OUR_V2_WINSIZE 16384
362 const static struct ssh_kex
*kex_algs
[] = {
363 &ssh_diffiehellman_gex
,
367 const static struct ssh_signkey
*hostkey_algs
[] = { &ssh_rsa
, &ssh_dss
};
369 static void nullmac_key(unsigned char *key
)
372 static void nullmac_generate(unsigned char *blk
, int len
,
376 static int nullmac_verify(unsigned char *blk
, int len
, unsigned long seq
)
380 const static struct ssh_mac ssh_mac_none
= {
381 nullmac_key
, nullmac_key
, nullmac_generate
, nullmac_verify
, "none", 0
383 const static struct ssh_mac
*macs
[] = {
384 &ssh_sha1
, &ssh_md5
, &ssh_mac_none
386 const static struct ssh_mac
*buggymacs
[] = {
387 &ssh_sha1_buggy
, &ssh_md5
, &ssh_mac_none
390 static void ssh_comp_none_init(void)
393 static int ssh_comp_none_block(unsigned char *block
, int len
,
394 unsigned char **outblock
, int *outlen
)
398 static int ssh_comp_none_disable(void)
402 const static struct ssh_compress ssh_comp_none
= {
404 ssh_comp_none_init
, ssh_comp_none_block
,
405 ssh_comp_none_init
, ssh_comp_none_block
,
406 ssh_comp_none_disable
408 extern const struct ssh_compress ssh_zlib
;
409 const static struct ssh_compress
*compressions
[] = {
410 &ssh_zlib
, &ssh_comp_none
413 enum { /* channel types */
418 CHAN_SOCKDATA_DORMANT
/* one the remote hasn't confirmed */
422 * 2-3-4 tree storing channels.
425 unsigned remoteid
, localid
;
429 struct ssh1_data_channel
{
432 struct ssh2_data_channel
{
434 unsigned remwindow
, remmaxpkt
;
439 struct ssh_agent_channel
{
440 unsigned char *message
;
441 unsigned char msglen
[4];
442 int lensofar
, totallen
;
444 struct ssh_x11_channel
{
447 struct ssh_pfd_channel
{
454 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
455 * 2 use this structure in different ways, reflecting SSH 2's
456 * altogether saner approach to port forwarding.
458 * In SSH 1, you arrange a remote forwarding by sending the server
459 * the remote port number, and the local destination host:port.
460 * When a connection comes in, the server sends you back that
461 * host:port pair, and you connect to it. This is a ready-made
462 * security hole if you're not on the ball: a malicious server
463 * could send you back _any_ host:port pair, so if you trustingly
464 * connect to the address it gives you then you've just opened the
465 * entire inside of your corporate network just by connecting
466 * through it to a dodgy SSH server. Hence, we must store a list of
467 * host:port pairs we _are_ trying to forward to, and reject a
468 * connection request from the server if it's not in the list.
470 * In SSH 2, each side of the connection minds its own business and
471 * doesn't send unnecessary information to the other. You arrange a
472 * remote forwarding by sending the server just the remote port
473 * number. When a connection comes in, the server tells you which
474 * of its ports was connected to; and _you_ have to remember what
475 * local host:port pair went with that port number.
477 * Hence: in SSH 1 this structure stores host:port pairs we intend
478 * to allow connections to, and is indexed by those host:port
479 * pairs. In SSH 2 it stores a mapping from source port to
480 * destination host:port pair, and is indexed by source port.
482 struct ssh_rportfwd
{
483 unsigned sport
, dport
;
496 static SHA_State exhash
, exhashbase
;
498 static Socket s
= NULL
;
500 static unsigned char session_key
[32];
501 static int ssh1_compressing
;
502 static int ssh1_remote_protoflags
;
503 static int ssh1_local_protoflags
;
504 static int ssh_agentfwd_enabled
;
505 static int ssh_X11_fwd_enabled
;
506 static int ssh_remote_bugs
;
507 static const struct ssh_cipher
*cipher
= NULL
;
508 static const struct ssh2_cipher
*cscipher
= NULL
;
509 static const struct ssh2_cipher
*sccipher
= NULL
;
510 static const struct ssh_mac
*csmac
= NULL
;
511 static const struct ssh_mac
*scmac
= NULL
;
512 static const struct ssh_compress
*cscomp
= NULL
;
513 static const struct ssh_compress
*sccomp
= NULL
;
514 static const struct ssh_kex
*kex
= NULL
;
515 static const struct ssh_signkey
*hostkey
= NULL
;
516 static unsigned char ssh2_session_id
[20];
517 int (*ssh_get_line
) (const char *prompt
, char *str
, int maxlen
,
520 static char *savedhost
;
521 static int savedport
;
522 static int ssh_send_ok
;
523 static int ssh_echoing
, ssh_editing
;
525 static tree234
*ssh_channels
; /* indexed by local id */
526 static struct ssh_channel
*mainchan
; /* primary session channel */
527 static int ssh_exitcode
= -1;
529 static tree234
*ssh_rportfwds
;
533 SSH_STATE_BEFORE_SIZE
,
537 } ssh_state
= SSH_STATE_PREPACKET
;
539 static int size_needed
= FALSE
, eof_needed
= FALSE
;
541 static struct Packet pktin
= { 0, 0, NULL
, NULL
, 0 };
542 static struct Packet pktout
= { 0, 0, NULL
, NULL
, 0 };
543 static unsigned char *deferred_send_data
= NULL
;
544 static int deferred_len
= 0, deferred_size
= 0;
547 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
548 * that fails. This variable is the means by which scp.c can reach
549 * into the SSH code and find out which one it got.
551 int ssh_fallback_cmd
= 0;
553 static int ssh_version
;
554 static int ssh1_throttle_count
;
555 static int ssh_overall_bufsize
;
556 static int ssh_throttled_all
;
557 static int ssh1_stdout_throttling
;
558 static void (*ssh_protocol
) (unsigned char *in
, int inlen
, int ispkt
);
559 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
);
560 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
);
561 static void ssh_size(void);
562 static void ssh_special(Telnet_Special
);
563 static int ssh2_try_send(struct ssh_channel
*c
);
564 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
566 static void ssh_throttle_all(int enable
, int bufsize
);
567 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
);
568 static int (*s_rdpkt
) (unsigned char **data
, int *datalen
);
569 static int ssh_sendbuffer(void);
571 static struct rdpkt1_state_tag
{
572 long len
, pad
, biglen
, to_read
;
573 unsigned long realcrc
, gotcrc
;
579 static struct rdpkt2_state_tag
{
580 long len
, pad
, payload
, packetlen
, maclen
;
583 unsigned long incoming_sequence
;
586 static int ssh_channelcmp(void *av
, void *bv
)
588 struct ssh_channel
*a
= (struct ssh_channel
*) av
;
589 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
590 if (a
->localid
< b
->localid
)
592 if (a
->localid
> b
->localid
)
596 static int ssh_channelfind(void *av
, void *bv
)
598 unsigned *a
= (unsigned *) av
;
599 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
607 static int ssh_rportcmp_ssh1(void *av
, void *bv
)
609 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
610 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
612 if ( (i
= strcmp(a
->dhost
, b
->dhost
)) != 0)
613 return i
< 0 ?
-1 : +1;
614 if (a
->dport
> b
->dport
)
616 if (a
->dport
< b
->dport
)
621 static int ssh_rportcmp_ssh2(void *av
, void *bv
)
623 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
624 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
626 if (a
->sport
> b
->sport
)
628 if (a
->sport
< b
->sport
)
633 static int alloc_channel_id(void)
635 const unsigned CHANNEL_NUMBER_OFFSET
= 256;
636 unsigned low
, high
, mid
;
638 struct ssh_channel
*c
;
641 * First-fit allocation of channel numbers: always pick the
642 * lowest unused one. To do this, binary-search using the
643 * counted B-tree to find the largest channel ID which is in a
644 * contiguous sequence from the beginning. (Precisely
645 * everything in that sequence must have ID equal to its tree
646 * index plus CHANNEL_NUMBER_OFFSET.)
648 tsize
= count234(ssh_channels
);
652 while (high
- low
> 1) {
653 mid
= (high
+ low
) / 2;
654 c
= index234(ssh_channels
, mid
);
655 if (c
->localid
== mid
+ CHANNEL_NUMBER_OFFSET
)
656 low
= mid
; /* this one is fine */
658 high
= mid
; /* this one is past it */
661 * Now low points to either -1, or the tree index of the
662 * largest ID in the initial sequence.
665 unsigned i
= low
+ 1 + CHANNEL_NUMBER_OFFSET
;
666 assert(NULL
== find234(ssh_channels
, &i
, ssh_channelfind
));
668 return low
+ 1 + CHANNEL_NUMBER_OFFSET
;
671 static void c_write(char *buf
, int len
)
673 if ((flags
& FLAG_STDERR
)) {
675 for (i
= 0; i
< len
; i
++)
677 fputc(buf
[i
], stderr
);
680 from_backend(1, buf
, len
);
683 static void c_write_untrusted(char *buf
, int len
)
686 for (i
= 0; i
< len
; i
++) {
689 else if ((buf
[i
] & 0x60) || (buf
[i
] == '\r'))
694 static void c_write_str(char *buf
)
696 c_write(buf
, strlen(buf
));
700 * Collect incoming data in the incoming packet buffer.
701 * Decipher and verify the packet when it is completely read.
702 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
703 * Update the *data and *datalen variables.
704 * Return the additional nr of bytes needed, or 0 when
705 * a complete packet is available.
707 static int ssh1_rdpkt(unsigned char **data
, int *datalen
)
709 struct rdpkt1_state_tag
*st
= &rdpkt1_state
;
718 for (st
->i
= st
->len
= 0; st
->i
< 4; st
->i
++) {
719 while ((*datalen
) == 0)
721 st
->len
= (st
->len
<< 8) + **data
;
722 (*data
)++, (*datalen
)--;
725 st
->pad
= 8 - (st
->len
% 8);
726 st
->biglen
= st
->len
+ st
->pad
;
727 pktin
.length
= st
->len
- 5;
729 if (pktin
.maxlen
< st
->biglen
) {
730 pktin
.maxlen
= st
->biglen
;
731 pktin
.data
= (pktin
.data
== NULL ?
smalloc(st
->biglen
+ APIEXTRA
) :
732 srealloc(pktin
.data
, st
->biglen
+ APIEXTRA
));
734 fatalbox("Out of memory");
737 st
->to_read
= st
->biglen
;
739 while (st
->to_read
> 0) {
740 st
->chunk
= st
->to_read
;
741 while ((*datalen
) == 0)
742 crReturn(st
->to_read
);
743 if (st
->chunk
> (*datalen
))
744 st
->chunk
= (*datalen
);
745 memcpy(st
->p
, *data
, st
->chunk
);
747 *datalen
-= st
->chunk
;
749 st
->to_read
-= st
->chunk
;
752 if (cipher
&& detect_attack(pktin
.data
, st
->biglen
, NULL
)) {
753 bombout(("Network attack (CRC compensation) detected!"));
758 cipher
->decrypt(pktin
.data
, st
->biglen
);
760 st
->realcrc
= crc32(pktin
.data
, st
->biglen
- 4);
761 st
->gotcrc
= GET_32BIT(pktin
.data
+ st
->biglen
- 4);
762 if (st
->gotcrc
!= st
->realcrc
) {
763 bombout(("Incorrect CRC received on packet"));
767 pktin
.body
= pktin
.data
+ st
->pad
+ 1;
769 if (ssh1_compressing
) {
770 unsigned char *decompblk
;
772 zlib_decompress_block(pktin
.body
- 1, pktin
.length
+ 1,
773 &decompblk
, &decomplen
);
775 if (pktin
.maxlen
< st
->pad
+ decomplen
) {
776 pktin
.maxlen
= st
->pad
+ decomplen
;
777 pktin
.data
= srealloc(pktin
.data
, pktin
.maxlen
+ APIEXTRA
);
778 pktin
.body
= pktin
.data
+ st
->pad
+ 1;
780 fatalbox("Out of memory");
783 memcpy(pktin
.body
- 1, decompblk
, decomplen
);
785 pktin
.length
= decomplen
- 1;
788 pktin
.type
= pktin
.body
[-1];
790 log_packet(PKT_INCOMING
, pktin
.type
, ssh1_pkt_type(pktin
.type
),
791 pktin
.body
, pktin
.length
);
793 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
794 pktin
.type
== SSH1_SMSG_STDERR_DATA
||
795 pktin
.type
== SSH1_MSG_DEBUG
||
796 pktin
.type
== SSH1_SMSG_AUTH_TIS_CHALLENGE
||
797 pktin
.type
== SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
798 long stringlen
= GET_32BIT(pktin
.body
);
799 if (stringlen
+ 4 != pktin
.length
) {
800 bombout(("Received data packet with bogus string length"));
805 if (pktin
.type
== SSH1_MSG_DEBUG
) {
806 /* log debug message */
808 int stringlen
= GET_32BIT(pktin
.body
);
809 strcpy(buf
, "Remote: ");
812 memcpy(buf
+ 8, pktin
.body
+ 4, stringlen
);
813 buf
[8 + stringlen
] = '\0';
816 } else if (pktin
.type
== SSH1_MSG_IGNORE
) {
821 if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
822 /* log reason code in disconnect message */
824 unsigned msglen
= GET_32BIT(pktin
.body
);
826 strcpy(buf
, "Remote sent disconnect: ");
827 nowlen
= strlen(buf
);
828 if (msglen
> sizeof(buf
) - nowlen
- 1)
829 msglen
= sizeof(buf
) - nowlen
- 1;
830 memcpy(buf
+ nowlen
, pktin
.body
+ 4, msglen
);
831 buf
[nowlen
+ msglen
] = '\0';
832 /* logevent(buf); (this is now done within the bombout macro) */
833 bombout(("Server sent disconnect message:\n\"%s\"", buf
+nowlen
));
840 static int ssh2_rdpkt(unsigned char **data
, int *datalen
)
842 struct rdpkt2_state_tag
*st
= &rdpkt2_state
;
850 st
->cipherblk
= sccipher
->blksize
;
853 if (st
->cipherblk
< 8)
856 if (pktin
.maxlen
< st
->cipherblk
) {
857 pktin
.maxlen
= st
->cipherblk
;
860 NULL ?
smalloc(st
->cipherblk
+
861 APIEXTRA
) : srealloc(pktin
.data
,
865 fatalbox("Out of memory");
869 * Acquire and decrypt the first block of the packet. This will
870 * contain the length and padding details.
872 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
873 while ((*datalen
) == 0)
874 crReturn(st
->cipherblk
- st
->i
);
875 pktin
.data
[st
->i
] = *(*data
)++;
880 sccipher
->decrypt(pktin
.data
, st
->cipherblk
);
883 * Now get the length and padding figures.
885 st
->len
= GET_32BIT(pktin
.data
);
886 st
->pad
= pktin
.data
[4];
889 * This enables us to deduce the payload length.
891 st
->payload
= st
->len
- st
->pad
- 1;
893 pktin
.length
= st
->payload
+ 5;
896 * So now we can work out the total packet length.
898 st
->packetlen
= st
->len
+ 4;
899 st
->maclen
= scmac ? scmac
->len
: 0;
902 * Adjust memory allocation if packet is too big.
904 if (pktin
.maxlen
< st
->packetlen
+ st
->maclen
) {
905 pktin
.maxlen
= st
->packetlen
+ st
->maclen
;
908 NULL ?
smalloc(pktin
.maxlen
+ APIEXTRA
) : srealloc(pktin
.data
,
913 fatalbox("Out of memory");
917 * Read and decrypt the remainder of the packet.
919 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
;
921 while ((*datalen
) == 0)
922 crReturn(st
->packetlen
+ st
->maclen
- st
->i
);
923 pktin
.data
[st
->i
] = *(*data
)++;
926 /* Decrypt everything _except_ the MAC. */
928 sccipher
->decrypt(pktin
.data
+ st
->cipherblk
,
929 st
->packetlen
- st
->cipherblk
);
935 && !scmac
->verify(pktin
.data
, st
->len
+ 4,
936 st
->incoming_sequence
)) {
937 bombout(("Incorrect MAC received on packet"));
940 st
->incoming_sequence
++; /* whether or not we MACed */
943 * Decompress packet payload.
946 unsigned char *newpayload
;
948 if (sccomp
&& sccomp
->decompress(pktin
.data
+ 5, pktin
.length
- 5,
949 &newpayload
, &newlen
)) {
950 if (pktin
.maxlen
< newlen
+ 5) {
951 pktin
.maxlen
= newlen
+ 5;
954 NULL ?
smalloc(pktin
.maxlen
+
955 APIEXTRA
) : srealloc(pktin
.data
,
959 fatalbox("Out of memory");
961 pktin
.length
= 5 + newlen
;
962 memcpy(pktin
.data
+ 5, newpayload
, newlen
);
968 pktin
.type
= pktin
.data
[5];
970 log_packet(PKT_INCOMING
, pktin
.type
, ssh2_pkt_type(pktin
.type
),
971 pktin
.data
+6, pktin
.length
-6);
973 switch (pktin
.type
) {
975 * These packets we must handle instantly.
977 case SSH2_MSG_DISCONNECT
:
979 /* log reason code in disconnect message */
981 int reason
= GET_32BIT(pktin
.data
+ 6);
982 unsigned msglen
= GET_32BIT(pktin
.data
+ 10);
984 if (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) {
985 sprintf(buf
, "Received disconnect message (%s)",
986 ssh2_disconnect_reasons
[reason
]);
988 sprintf(buf
, "Received disconnect message (unknown type %d)",
992 strcpy(buf
, "Disconnection message text: ");
993 nowlen
= strlen(buf
);
994 if (msglen
> sizeof(buf
) - nowlen
- 1)
995 msglen
= sizeof(buf
) - nowlen
- 1;
996 memcpy(buf
+ nowlen
, pktin
.data
+ 14, msglen
);
997 buf
[nowlen
+ msglen
] = '\0';
999 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1001 (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) ?
1002 ssh2_disconnect_reasons
[reason
] : "unknown",
1007 case SSH2_MSG_IGNORE
:
1009 case SSH2_MSG_DEBUG
:
1011 /* log the debug message */
1013 /* int display = pktin.body[6]; */
1014 int stringlen
= GET_32BIT(pktin
.data
+7);
1016 strcpy(buf
, "Remote debug message: ");
1017 prefix
= strlen(buf
);
1018 if (stringlen
> sizeof(buf
)-prefix
-1)
1019 stringlen
= sizeof(buf
)-prefix
-1;
1020 memcpy(buf
+ prefix
, pktin
.data
+ 11, stringlen
);
1021 buf
[prefix
+ stringlen
] = '\0';
1024 goto next_packet
; /* FIXME: print the debug message */
1027 * These packets we need do nothing about here.
1029 case SSH2_MSG_UNIMPLEMENTED
:
1030 case SSH2_MSG_SERVICE_REQUEST
:
1031 case SSH2_MSG_SERVICE_ACCEPT
:
1032 case SSH2_MSG_KEXINIT
:
1033 case SSH2_MSG_NEWKEYS
:
1034 case SSH2_MSG_KEXDH_INIT
:
1035 case SSH2_MSG_KEXDH_REPLY
:
1036 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1037 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1038 case SSH2_MSG_KEX_DH_GEX_INIT
:
1039 case SSH2_MSG_KEX_DH_GEX_REPLY
:
1040 case SSH2_MSG_USERAUTH_REQUEST
:
1041 case SSH2_MSG_USERAUTH_FAILURE
:
1042 case SSH2_MSG_USERAUTH_SUCCESS
:
1043 case SSH2_MSG_USERAUTH_BANNER
:
1044 case SSH2_MSG_USERAUTH_PK_OK
:
1045 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1046 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1047 case SSH2_MSG_USERAUTH_INFO_RESPONSE
:
1048 case SSH2_MSG_GLOBAL_REQUEST
:
1049 case SSH2_MSG_REQUEST_SUCCESS
:
1050 case SSH2_MSG_REQUEST_FAILURE
:
1051 case SSH2_MSG_CHANNEL_OPEN
:
1052 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
:
1053 case SSH2_MSG_CHANNEL_OPEN_FAILURE
:
1054 case SSH2_MSG_CHANNEL_WINDOW_ADJUST
:
1055 case SSH2_MSG_CHANNEL_DATA
:
1056 case SSH2_MSG_CHANNEL_EXTENDED_DATA
:
1057 case SSH2_MSG_CHANNEL_EOF
:
1058 case SSH2_MSG_CHANNEL_CLOSE
:
1059 case SSH2_MSG_CHANNEL_REQUEST
:
1060 case SSH2_MSG_CHANNEL_SUCCESS
:
1061 case SSH2_MSG_CHANNEL_FAILURE
:
1065 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1068 ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED
);
1069 ssh2_pkt_adduint32(st
->incoming_sequence
- 1);
1077 static void ssh1_pktout_size(int len
)
1081 len
+= 5; /* type and CRC */
1082 pad
= 8 - (len
% 8);
1085 pktout
.length
= len
- 5;
1086 if (pktout
.maxlen
< biglen
) {
1087 pktout
.maxlen
= biglen
;
1089 /* Allocate enough buffer space for extra block
1090 * for MS CryptEncrypt() */
1091 pktout
.data
= (pktout
.data
== NULL ?
smalloc(biglen
+ 12) :
1092 srealloc(pktout
.data
, biglen
+ 12));
1094 pktout
.data
= (pktout
.data
== NULL ?
smalloc(biglen
+ 4) :
1095 srealloc(pktout
.data
, biglen
+ 4));
1098 fatalbox("Out of memory");
1100 pktout
.body
= pktout
.data
+ 4 + pad
+ 1;
1103 static void s_wrpkt_start(int type
, int len
)
1105 ssh1_pktout_size(len
);
1109 static int s_wrpkt_prepare(void)
1111 int pad
, len
, biglen
, i
;
1114 pktout
.body
[-1] = pktout
.type
;
1116 log_packet(PKT_OUTGOING
, pktout
.type
, ssh1_pkt_type(pktout
.type
),
1117 pktout
.body
, pktout
.length
);
1119 if (ssh1_compressing
) {
1120 unsigned char *compblk
;
1122 zlib_compress_block(pktout
.body
- 1, pktout
.length
+ 1,
1123 &compblk
, &complen
);
1124 ssh1_pktout_size(complen
- 1);
1125 memcpy(pktout
.body
- 1, compblk
, complen
);
1129 len
= pktout
.length
+ 5; /* type and CRC */
1130 pad
= 8 - (len
% 8);
1133 for (i
= 0; i
< pad
; i
++)
1134 pktout
.data
[i
+ 4] = random_byte();
1135 crc
= crc32(pktout
.data
+ 4, biglen
- 4);
1136 PUT_32BIT(pktout
.data
+ biglen
, crc
);
1137 PUT_32BIT(pktout
.data
, len
);
1140 cipher
->encrypt(pktout
.data
+ 4, biglen
);
1145 static void s_wrpkt(void)
1148 len
= s_wrpkt_prepare();
1149 backlog
= sk_write(s
, pktout
.data
, len
);
1150 if (backlog
> SSH_MAX_BACKLOG
)
1151 ssh_throttle_all(1, backlog
);
1154 static void s_wrpkt_defer(void)
1157 len
= s_wrpkt_prepare();
1158 if (deferred_len
+ len
> deferred_size
) {
1159 deferred_size
= deferred_len
+ len
+ 128;
1160 deferred_send_data
= srealloc(deferred_send_data
, deferred_size
);
1162 memcpy(deferred_send_data
+ deferred_len
, pktout
.data
, len
);
1163 deferred_len
+= len
;
1167 * Construct a packet with the specified contents.
1169 static void construct_packet(int pkttype
, va_list ap1
, va_list ap2
)
1171 unsigned char *p
, *argp
, argchar
;
1172 unsigned long argint
;
1173 int pktlen
, argtype
, arglen
;
1177 while ((argtype
= va_arg(ap1
, int)) != PKT_END
) {
1180 (void) va_arg(ap1
, int);
1184 (void) va_arg(ap1
, char);
1188 (void) va_arg(ap1
, unsigned char *);
1189 arglen
= va_arg(ap1
, int);
1193 argp
= va_arg(ap1
, unsigned char *);
1194 arglen
= strlen(argp
);
1195 pktlen
+= 4 + arglen
;
1198 bn
= va_arg(ap1
, Bignum
);
1199 pktlen
+= ssh1_bignum_length(bn
);
1206 s_wrpkt_start(pkttype
, pktlen
);
1209 while ((argtype
= va_arg(ap2
, int)) != PKT_END
) {
1212 argint
= va_arg(ap2
, int);
1213 PUT_32BIT(p
, argint
);
1217 argchar
= va_arg(ap2
, unsigned char);
1222 argp
= va_arg(ap2
, unsigned char *);
1223 arglen
= va_arg(ap2
, int);
1224 memcpy(p
, argp
, arglen
);
1228 argp
= va_arg(ap2
, unsigned char *);
1229 arglen
= strlen(argp
);
1230 PUT_32BIT(p
, arglen
);
1231 memcpy(p
+ 4, argp
, arglen
);
1235 bn
= va_arg(ap2
, Bignum
);
1236 p
+= ssh1_write_bignum(p
, bn
);
1242 static void send_packet(int pkttype
, ...)
1245 va_start(ap1
, pkttype
);
1246 va_start(ap2
, pkttype
);
1247 construct_packet(pkttype
, ap1
, ap2
);
1251 static void defer_packet(int pkttype
, ...)
1254 va_start(ap1
, pkttype
);
1255 va_start(ap2
, pkttype
);
1256 construct_packet(pkttype
, ap1
, ap2
);
1260 static int ssh_versioncmp(char *a
, char *b
)
1263 unsigned long av
, bv
;
1265 av
= strtoul(a
, &ae
, 10);
1266 bv
= strtoul(b
, &be
, 10);
1268 return (av
< bv ?
-1 : +1);
1273 av
= strtoul(ae
, &ae
, 10);
1274 bv
= strtoul(be
, &be
, 10);
1276 return (av
< bv ?
-1 : +1);
1282 * Utility routines for putting an SSH-protocol `string' and
1283 * `uint32' into a SHA state.
1286 static void sha_string(SHA_State
* s
, void *str
, int len
)
1288 unsigned char lenblk
[4];
1289 PUT_32BIT(lenblk
, len
);
1290 SHA_Bytes(s
, lenblk
, 4);
1291 SHA_Bytes(s
, str
, len
);
1294 static void sha_uint32(SHA_State
* s
, unsigned i
)
1296 unsigned char intblk
[4];
1297 PUT_32BIT(intblk
, i
);
1298 SHA_Bytes(s
, intblk
, 4);
1302 * SSH2 packet construction functions.
1304 static void ssh2_pkt_ensure(int length
)
1306 if (pktout
.maxlen
< length
) {
1307 pktout
.maxlen
= length
+ 256;
1310 NULL ?
smalloc(pktout
.maxlen
+
1311 APIEXTRA
) : srealloc(pktout
.data
,
1315 fatalbox("Out of memory");
1318 static void ssh2_pkt_adddata(void *data
, int len
)
1320 pktout
.length
+= len
;
1321 ssh2_pkt_ensure(pktout
.length
);
1322 memcpy(pktout
.data
+ pktout
.length
- len
, data
, len
);
1324 static void ssh2_pkt_addbyte(unsigned char byte
)
1326 ssh2_pkt_adddata(&byte
, 1);
1328 static void ssh2_pkt_init(int pkt_type
)
1331 ssh2_pkt_addbyte((unsigned char) pkt_type
);
1333 static void ssh2_pkt_addbool(unsigned char value
)
1335 ssh2_pkt_adddata(&value
, 1);
1337 static void ssh2_pkt_adduint32(unsigned long value
)
1340 PUT_32BIT(x
, value
);
1341 ssh2_pkt_adddata(x
, 4);
1343 static void ssh2_pkt_addstring_start(void)
1345 ssh2_pkt_adduint32(0);
1346 pktout
.savedpos
= pktout
.length
;
1348 static void ssh2_pkt_addstring_str(char *data
)
1350 ssh2_pkt_adddata(data
, strlen(data
));
1351 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
1352 pktout
.length
- pktout
.savedpos
);
1354 static void ssh2_pkt_addstring_data(char *data
, int len
)
1356 ssh2_pkt_adddata(data
, len
);
1357 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
1358 pktout
.length
- pktout
.savedpos
);
1360 static void ssh2_pkt_addstring(char *data
)
1362 ssh2_pkt_addstring_start();
1363 ssh2_pkt_addstring_str(data
);
1365 static char *ssh2_mpint_fmt(Bignum b
, int *len
)
1368 int i
, n
= (bignum_bitcount(b
) + 7) / 8;
1371 fatalbox("out of memory");
1373 for (i
= 1; i
<= n
; i
++)
1374 p
[i
] = bignum_byte(b
, n
- i
);
1376 while (i
<= n
&& p
[i
] == 0 && (p
[i
+ 1] & 0x80) == 0)
1378 memmove(p
, p
+ i
, n
+ 1 - i
);
1382 static void ssh2_pkt_addmp(Bignum b
)
1386 p
= ssh2_mpint_fmt(b
, &len
);
1387 ssh2_pkt_addstring_start();
1388 ssh2_pkt_addstring_data(p
, len
);
1393 * Construct an SSH2 final-form packet: compress it, encrypt it,
1394 * put the MAC on it. Final packet, ready to be sent, is stored in
1395 * pktout.data. Total length is returned.
1397 static int ssh2_pkt_construct(void)
1399 int cipherblk
, maclen
, padding
, i
;
1400 static unsigned long outgoing_sequence
= 0;
1402 log_packet(PKT_OUTGOING
, pktout
.data
[5], ssh2_pkt_type(pktout
.data
[5]),
1403 pktout
.data
+ 6, pktout
.length
- 6);
1406 * Compress packet payload.
1409 unsigned char *newpayload
;
1411 if (cscomp
&& cscomp
->compress(pktout
.data
+ 5, pktout
.length
- 5,
1412 &newpayload
, &newlen
)) {
1414 ssh2_pkt_adddata(newpayload
, newlen
);
1420 * Add padding. At least four bytes, and must also bring total
1421 * length (minus MAC) up to a multiple of the block size.
1423 cipherblk
= cscipher ? cscipher
->blksize
: 8; /* block size */
1424 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
1427 (cipherblk
- (pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
1428 maclen
= csmac ? csmac
->len
: 0;
1429 ssh2_pkt_ensure(pktout
.length
+ padding
+ maclen
);
1430 pktout
.data
[4] = padding
;
1431 for (i
= 0; i
< padding
; i
++)
1432 pktout
.data
[pktout
.length
+ i
] = random_byte();
1433 PUT_32BIT(pktout
.data
, pktout
.length
+ padding
- 4);
1435 csmac
->generate(pktout
.data
, pktout
.length
+ padding
,
1437 outgoing_sequence
++; /* whether or not we MACed */
1440 cscipher
->encrypt(pktout
.data
, pktout
.length
+ padding
);
1442 /* Ready-to-send packet starts at pktout.data. We return length. */
1443 return pktout
.length
+ padding
+ maclen
;
1447 * Construct and send an SSH2 packet immediately.
1449 static void ssh2_pkt_send(void)
1453 len
= ssh2_pkt_construct();
1454 backlog
= sk_write(s
, pktout
.data
, len
);
1455 if (backlog
> SSH_MAX_BACKLOG
)
1456 ssh_throttle_all(1, backlog
);
1460 * Construct an SSH2 packet and add it to a deferred data block.
1461 * Useful for sending multiple packets in a single sk_write() call,
1462 * to prevent a traffic-analysing listener from being able to work
1463 * out the length of any particular packet (such as the password
1466 * Note that because SSH2 sequence-numbers its packets, this can
1467 * NOT be used as an m4-style `defer' allowing packets to be
1468 * constructed in one order and sent in another.
1470 static void ssh2_pkt_defer(void)
1472 int len
= ssh2_pkt_construct();
1473 if (deferred_len
+ len
> deferred_size
) {
1474 deferred_size
= deferred_len
+ len
+ 128;
1475 deferred_send_data
= srealloc(deferred_send_data
, deferred_size
);
1477 memcpy(deferred_send_data
+ deferred_len
, pktout
.data
, len
);
1478 deferred_len
+= len
;
1482 * Send the whole deferred data block constructed by
1483 * ssh2_pkt_defer() or SSH1's defer_packet().
1485 static void ssh_pkt_defersend(void)
1488 backlog
= sk_write(s
, deferred_send_data
, deferred_len
);
1489 deferred_len
= deferred_size
= 0;
1490 sfree(deferred_send_data
);
1491 deferred_send_data
= NULL
;
1492 if (backlog
> SSH_MAX_BACKLOG
)
1493 ssh_throttle_all(1, backlog
);
1497 void bndebug(char *string
, Bignum b
)
1501 p
= ssh2_mpint_fmt(b
, &len
);
1502 debug(("%s", string
));
1503 for (i
= 0; i
< len
; i
++)
1504 debug((" %02x", p
[i
]));
1510 static void sha_mpint(SHA_State
* s
, Bignum b
)
1514 p
= ssh2_mpint_fmt(b
, &len
);
1515 sha_string(s
, p
, len
);
1520 * SSH2 packet decode functions.
1522 static unsigned long ssh2_pkt_getuint32(void)
1524 unsigned long value
;
1525 if (pktin
.length
- pktin
.savedpos
< 4)
1526 return 0; /* arrgh, no way to decline (FIXME?) */
1527 value
= GET_32BIT(pktin
.data
+ pktin
.savedpos
);
1528 pktin
.savedpos
+= 4;
1531 static int ssh2_pkt_getbool(void)
1533 unsigned long value
;
1534 if (pktin
.length
- pktin
.savedpos
< 1)
1535 return 0; /* arrgh, no way to decline (FIXME?) */
1536 value
= pktin
.data
[pktin
.savedpos
] != 0;
1540 static void ssh2_pkt_getstring(char **p
, int *length
)
1543 if (pktin
.length
- pktin
.savedpos
< 4)
1545 *length
= GET_32BIT(pktin
.data
+ pktin
.savedpos
);
1546 pktin
.savedpos
+= 4;
1547 if (pktin
.length
- pktin
.savedpos
< *length
)
1549 *p
= pktin
.data
+ pktin
.savedpos
;
1550 pktin
.savedpos
+= *length
;
1552 static Bignum
ssh2_pkt_getmp(void)
1558 ssh2_pkt_getstring(&p
, &length
);
1562 bombout(("internal error: Can't handle negative mpints"));
1565 b
= bignum_from_bytes(p
, length
);
1570 * Examine the remote side's version string and compare it against
1571 * a list of known buggy implementations.
1573 static void ssh_detect_bugs(char *vstring
)
1575 char *imp
; /* pointer to implementation part */
1577 imp
+= strcspn(imp
, "-");
1579 imp
+= strcspn(imp
, "-");
1582 ssh_remote_bugs
= 0;
1584 if (!strcmp(imp
, "1.2.18") || !strcmp(imp
, "1.2.19") ||
1585 !strcmp(imp
, "1.2.20") || !strcmp(imp
, "1.2.21") ||
1586 !strcmp(imp
, "1.2.22") || !strcmp(imp
, "Cisco-1.25")) {
1588 * These versions don't support SSH1_MSG_IGNORE, so we have
1589 * to use a different defence against password length
1592 ssh_remote_bugs
|= BUG_CHOKES_ON_SSH1_IGNORE
;
1593 logevent("We believe remote version has SSH1 ignore bug");
1596 if (!strcmp(imp
, "Cisco-1.25")) {
1598 * These versions need a plain password sent; they can't
1599 * handle having a null and a random length of data after
1602 ssh_remote_bugs
|= BUG_NEEDS_SSH1_PLAIN_PASSWORD
;
1603 logevent("We believe remote version needs a plain SSH1 password");
1606 if (!strcmp(imp
, "Cisco-1.25")) {
1608 * These versions apparently have no clue whatever about
1609 * RSA authentication and will panic and die if they see
1610 * an AUTH_RSA message.
1612 ssh_remote_bugs
|= BUG_CHOKES_ON_RSA
;
1613 logevent("We believe remote version can't handle RSA authentication");
1616 if (!strncmp(imp
, "2.1.0", 5) || !strncmp(imp
, "2.0.", 4) ||
1617 !strncmp(imp
, "2.2.0", 5) || !strncmp(imp
, "2.3.0", 5) ||
1618 !strncmp(imp
, "2.1 ", 4)) {
1620 * These versions have the HMAC bug.
1622 ssh_remote_bugs
|= BUG_SSH2_HMAC
;
1623 logevent("We believe remote version has SSH2 HMAC bug");
1627 static int do_ssh_init(unsigned char c
)
1630 static char version
[10];
1631 static char *vstring
;
1632 static int vstrsize
;
1638 /* Search for the string "SSH-" in the input. */
1641 static const int transS
[] = { 1, 2, 2, 1 };
1642 static const int transH
[] = { 0, 0, 3, 0 };
1643 static const int transminus
[] = { 0, 0, 0, -1 };
1654 crReturn(1); /* get another character */
1658 vstring
= smalloc(vstrsize
);
1659 strcpy(vstring
, "SSH-");
1663 crReturn(1); /* get another char */
1664 if (vslen
>= vstrsize
- 1) {
1666 vstring
= srealloc(vstring
, vstrsize
);
1668 vstring
[vslen
++] = c
;
1673 } else if (i
< sizeof(version
) - 1)
1675 } else if (c
== '\n')
1679 ssh_agentfwd_enabled
= FALSE
;
1680 rdpkt2_state
.incoming_sequence
= 0;
1683 vlog
= smalloc(20 + vslen
);
1684 vstring
[strcspn (vstring
, "\r\n")] = '\0'; /* remove end-of-line chars */
1685 sprintf(vlog
, "Server version: %s", vstring
);
1687 ssh_detect_bugs(vstring
);
1691 * Server version "1.99" means we can choose whether we use v1
1692 * or v2 protocol. Choice is based on cfg.sshprot.
1694 if (ssh_versioncmp(version
, cfg
.sshprot
== 1 ?
"2.0" : "1.99") >= 0) {
1696 * This is a v2 server. Begin v2 protocol.
1698 char verstring
[80], vlog
[100];
1699 sprintf(verstring
, "SSH-2.0-%s", sshver
);
1700 SHA_Init(&exhashbase
);
1702 * Hash our version string and their version string.
1704 sha_string(&exhashbase
, verstring
, strlen(verstring
));
1705 sha_string(&exhashbase
, vstring
, strcspn(vstring
, "\r\n"));
1706 sprintf(vlog
, "We claim version: %s", verstring
);
1708 strcat(verstring
, "\n");
1709 logevent("Using SSH protocol version 2");
1710 sk_write(s
, verstring
, strlen(verstring
));
1711 ssh_protocol
= ssh2_protocol
;
1713 s_rdpkt
= ssh2_rdpkt
;
1716 * This is a v1 server. Begin v1 protocol.
1718 char verstring
[80], vlog
[100];
1719 sprintf(verstring
, "SSH-%s-%s",
1720 (ssh_versioncmp(version
, "1.5") <= 0 ? version
: "1.5"),
1722 sprintf(vlog
, "We claim version: %s", verstring
);
1724 strcat(verstring
, "\n");
1726 if (cfg
.sshprot
== 3) {
1727 bombout(("SSH protocol version 2 required by user but not provided by server"));
1731 logevent("Using SSH protocol version 1");
1732 sk_write(s
, verstring
, strlen(verstring
));
1733 ssh_protocol
= ssh1_protocol
;
1735 s_rdpkt
= ssh1_rdpkt
;
1737 ssh_state
= SSH_STATE_BEFORE_SIZE
;
1744 static void ssh_gotdata(unsigned char *data
, int datalen
)
1749 * To begin with, feed the characters one by one to the
1750 * protocol initialisation / selection function do_ssh_init().
1751 * When that returns 0, we're done with the initial greeting
1752 * exchange and can move on to packet discipline.
1757 crReturnV
; /* more data please */
1758 ret
= do_ssh_init(*data
);
1766 * We emerge from that loop when the initial negotiation is
1767 * over and we have selected an s_rdpkt function. Now pass
1768 * everything to s_rdpkt, and then pass the resulting packets
1769 * to the proper protocol handler.
1774 while (datalen
> 0) {
1775 if (s_rdpkt(&data
, &datalen
) == 0) {
1776 if (ssh_state
== SSH_STATE_CLOSED
) {
1779 ssh_protocol(NULL
, 0, 1);
1780 if (ssh_state
== SSH_STATE_CLOSED
) {
1790 static int ssh_closing(Plug plug
, char *error_msg
, int error_code
,
1793 ssh_state
= SSH_STATE_CLOSED
;
1799 /* A socket error has occurred. */
1800 logevent(error_msg
);
1801 connection_fatal(error_msg
);
1803 /* Otherwise, the remote side closed the connection normally. */
1808 static int ssh_receive(Plug plug
, int urgent
, char *data
, int len
)
1810 ssh_gotdata(data
, len
);
1811 if (ssh_state
== SSH_STATE_CLOSED
) {
1821 static void ssh_sent(Plug plug
, int bufsize
)
1824 * If the send backlog on the SSH socket itself clears, we
1825 * should unthrottle the whole world if it was throttled.
1827 if (bufsize
< SSH_MAX_BACKLOG
)
1828 ssh_throttle_all(0, bufsize
);
1832 * Connect to specified host and port.
1833 * Returns an error message, or NULL on success.
1834 * Also places the canonical host name into `realhost'. It must be
1835 * freed by the caller.
1837 static char *connect_to_host(char *host
, int port
, char **realhost
, int nodelay
)
1839 static struct plug_function_table fn_table
= {
1844 }, *fn_table_ptr
= &fn_table
;
1853 savedhost
= smalloc(1 + strlen(host
));
1855 fatalbox("Out of memory");
1856 strcpy(savedhost
, host
);
1859 port
= 22; /* default ssh port */
1874 sprintf(buf
, "Looking up host \"%.170s\"", host
);
1877 addr
= sk_namelookup(host
, realhost
);
1878 if ((err
= sk_addr_error(addr
)))
1882 *realhost
= strdup(FWhost
);
1889 char buf
[200], addrbuf
[100];
1890 sk_getaddr(addr
, addrbuf
, 100);
1891 sprintf(buf
, "Connecting to %.100s port %d", addrbuf
, port
);
1894 s
= new_connection(addr
, *realhost
, port
, 0, 1, nodelay
, &fn_table_ptr
);
1895 if ((err
= sk_socket_error(s
))) {
1901 sk_write(s
, "connect ", 8);
1902 sk_write(s
, FWhost
, strlen(FWhost
));
1905 sprintf(buf
, " %d\n", FWport
);
1906 sk_write(s
, buf
, strlen(buf
));
1914 * Throttle or unthrottle the SSH connection.
1916 static void ssh1_throttle(int adjust
)
1918 int old_count
= ssh1_throttle_count
;
1919 ssh1_throttle_count
+= adjust
;
1920 assert(ssh1_throttle_count
>= 0);
1921 if (ssh1_throttle_count
&& !old_count
) {
1922 sk_set_frozen(s
, 1);
1923 } else if (!ssh1_throttle_count
&& old_count
) {
1924 sk_set_frozen(s
, 0);
1929 * Throttle or unthrottle _all_ local data streams (for when sends
1930 * on the SSH connection itself back up).
1932 static void ssh_throttle_all(int enable
, int bufsize
)
1935 struct ssh_channel
*c
;
1937 if (enable
== ssh_throttled_all
)
1939 ssh_throttled_all
= enable
;
1940 ssh_overall_bufsize
= bufsize
;
1943 for (i
= 0; NULL
!= (c
= index234(ssh_channels
, i
)); i
++) {
1945 case CHAN_MAINSESSION
:
1947 * This is treated separately, outside the switch.
1951 x11_override_throttle(c
->u
.x11
.s
, enable
);
1954 /* Agent channels require no buffer management. */
1957 pfd_override_throttle(c
->u
.x11
.s
, enable
);
1964 * Handle the key exchange and user authentication phases.
1966 static int do_ssh1_login(unsigned char *in
, int inlen
, int ispkt
)
1970 static unsigned char *rsabuf
, *keystr1
, *keystr2
;
1971 unsigned char cookie
[8];
1972 struct RSAKey servkey
, hostkey
;
1973 struct MD5Context md5c
;
1974 static unsigned long supported_ciphers_mask
, supported_auths_mask
;
1975 static int tried_publickey
, tried_agent
;
1976 static int tis_auth_refused
, ccard_auth_refused
;
1977 static unsigned char session_id
[16];
1978 static int cipher_type
;
1979 static char username
[100];
1980 static void *publickey_blob
;
1981 int publickey_bloblen
;
1988 if (pktin
.type
!= SSH1_SMSG_PUBLIC_KEY
) {
1989 bombout(("Public key packet not received"));
1993 logevent("Received public keys");
1995 memcpy(cookie
, pktin
.body
, 8);
1997 i
= makekey(pktin
.body
+ 8, &servkey
, &keystr1
, 0);
1998 j
= makekey(pktin
.body
+ 8 + i
, &hostkey
, &keystr2
, 0);
2001 * Log the host key fingerprint.
2005 logevent("Host key fingerprint is:");
2006 strcpy(logmsg
, " ");
2007 hostkey
.comment
= NULL
;
2008 rsa_fingerprint(logmsg
+ strlen(logmsg
),
2009 sizeof(logmsg
) - strlen(logmsg
), &hostkey
);
2013 ssh1_remote_protoflags
= GET_32BIT(pktin
.body
+ 8 + i
+ j
);
2014 supported_ciphers_mask
= GET_32BIT(pktin
.body
+ 12 + i
+ j
);
2015 supported_auths_mask
= GET_32BIT(pktin
.body
+ 16 + i
+ j
);
2017 ssh1_local_protoflags
=
2018 ssh1_remote_protoflags
& SSH1_PROTOFLAGS_SUPPORTED
;
2019 ssh1_local_protoflags
|= SSH1_PROTOFLAG_SCREEN_NUMBER
;
2022 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
2023 MD5Update(&md5c
, keystr1
, servkey
.bytes
);
2024 MD5Update(&md5c
, pktin
.body
, 8);
2025 MD5Final(session_id
, &md5c
);
2027 for (i
= 0; i
< 32; i
++)
2028 session_key
[i
] = random_byte();
2030 len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
2032 rsabuf
= smalloc(len
);
2034 fatalbox("Out of memory");
2037 * Verify the host key.
2041 * First format the key into a string.
2043 int len
= rsastr_len(&hostkey
);
2044 char fingerprint
[100];
2045 char *keystr
= smalloc(len
);
2047 fatalbox("Out of memory");
2048 rsastr_fmt(keystr
, &hostkey
);
2049 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
2050 verify_ssh_host_key(savedhost
, savedport
, "rsa", keystr
,
2055 for (i
= 0; i
< 32; i
++) {
2056 rsabuf
[i
] = session_key
[i
];
2058 rsabuf
[i
] ^= session_id
[i
];
2061 if (hostkey
.bytes
> servkey
.bytes
) {
2062 rsaencrypt(rsabuf
, 32, &servkey
);
2063 rsaencrypt(rsabuf
, servkey
.bytes
, &hostkey
);
2065 rsaencrypt(rsabuf
, 32, &hostkey
);
2066 rsaencrypt(rsabuf
, hostkey
.bytes
, &servkey
);
2069 logevent("Encrypted session key");
2072 int cipher_chosen
= 0, warn
= 0;
2073 char *cipher_string
= NULL
;
2074 for (i
= 0; !cipher_chosen
&& i
< CIPHER_MAX
; i
++) {
2075 int next_cipher
= cfg
.ssh_cipherlist
[i
];
2076 if (next_cipher
== CIPHER_WARN
) {
2077 /* If/when we choose a cipher, warn about it */
2079 } else if (next_cipher
== CIPHER_AES
) {
2080 /* XXX Probably don't need to mention this. */
2081 logevent("AES not supported in SSH1, skipping");
2083 switch (next_cipher
) {
2084 case CIPHER_3DES
: cipher_type
= SSH_CIPHER_3DES
;
2085 cipher_string
= "3DES"; break;
2086 case CIPHER_BLOWFISH
: cipher_type
= SSH_CIPHER_BLOWFISH
;
2087 cipher_string
= "Blowfish"; break;
2088 case CIPHER_DES
: cipher_type
= SSH_CIPHER_DES
;
2089 cipher_string
= "single-DES"; break;
2091 if (supported_ciphers_mask
& (1 << cipher_type
))
2095 if (!cipher_chosen
) {
2096 if ((supported_ciphers_mask
& (1 << SSH_CIPHER_3DES
)) == 0)
2097 bombout(("Server violates SSH 1 protocol by not "
2098 "supporting 3DES encryption"));
2100 /* shouldn't happen */
2101 bombout(("No supported ciphers found"));
2105 /* Warn about chosen cipher if necessary. */
2107 askcipher(cipher_string
, 0);
2110 switch (cipher_type
) {
2111 case SSH_CIPHER_3DES
:
2112 logevent("Using 3DES encryption");
2114 case SSH_CIPHER_DES
:
2115 logevent("Using single-DES encryption");
2117 case SSH_CIPHER_BLOWFISH
:
2118 logevent("Using Blowfish encryption");
2122 send_packet(SSH1_CMSG_SESSION_KEY
,
2123 PKT_CHAR
, cipher_type
,
2124 PKT_DATA
, cookie
, 8,
2125 PKT_CHAR
, (len
* 8) >> 8, PKT_CHAR
, (len
* 8) & 0xFF,
2126 PKT_DATA
, rsabuf
, len
,
2127 PKT_INT
, ssh1_local_protoflags
, PKT_END
);
2129 logevent("Trying to enable encryption...");
2133 cipher
= cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
2134 cipher_type
== SSH_CIPHER_DES ?
&ssh_des
: &ssh_3des
;
2135 cipher
->sesskey(session_key
);
2139 if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2140 bombout(("Encryption not successfully enabled"));
2144 logevent("Successfully started encryption");
2150 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
2152 if (!ssh_get_line("login as: ",
2153 username
, sizeof(username
), FALSE
)) {
2155 * get_line failed to get a username.
2158 logevent("No username provided. Abandoning session.");
2159 ssh_state
= SSH_STATE_CLOSED
;
2163 c_write_str("login as: ");
2166 crWaitUntil(!ispkt
);
2168 switch (c
= *in
++) {
2177 c_write_str("\b \b");
2184 c_write_str("\b \b");
2193 if (((c
>= ' ' && c
<= '~') ||
2194 ((unsigned char) c
>= 160))
2195 && pos
< sizeof(username
)-1) {
2196 username
[pos
++] = c
;
2202 c_write_str("\r\n");
2203 username
[strcspn(username
, "\n\r")] = '\0';
2206 strncpy(username
, cfg
.username
, 99);
2207 username
[99] = '\0';
2210 send_packet(SSH1_CMSG_USER
, PKT_STR
, username
, PKT_END
);
2212 char userlog
[22 + sizeof(username
)];
2213 sprintf(userlog
, "Sent username \"%s\"", username
);
2215 if (flags
& FLAG_INTERACTIVE
&&
2216 (!((flags
& FLAG_STDERR
) && (flags
& FLAG_VERBOSE
)))) {
2217 strcat(userlog
, "\r\n");
2218 c_write_str(userlog
);
2225 if ((ssh_remote_bugs
& BUG_CHOKES_ON_RSA
)) {
2226 /* We must not attempt PK auth. Pretend we've already tried it. */
2227 tried_publickey
= tried_agent
= 1;
2229 tried_publickey
= tried_agent
= 0;
2231 tis_auth_refused
= ccard_auth_refused
= 0;
2232 /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
2234 if (!rsakey_pubblob(cfg
.keyfile
, &publickey_blob
, &publickey_bloblen
))
2235 publickey_blob
= NULL
;
2237 publickey_blob
= NULL
;
2239 while (pktin
.type
== SSH1_SMSG_FAILURE
) {
2240 static char password
[100];
2241 static char prompt
[200];
2244 static int pwpkt_type
;
2245 pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
2247 if (agent_exists() && !tried_agent
) {
2249 * Attempt RSA authentication using Pageant.
2251 static unsigned char request
[5], *response
, *p
;
2252 static int responselen
;
2253 static int i
, nkeys
;
2254 static int authed
= FALSE
;
2258 logevent("Pageant is running. Requesting keys.");
2260 /* Request the keys held by the agent. */
2261 PUT_32BIT(request
, 1);
2262 request
[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES
;
2263 agent_query(request
, 5, &r
, &responselen
);
2264 response
= (unsigned char *) r
;
2265 if (response
&& responselen
>= 5 &&
2266 response
[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER
) {
2268 nkeys
= GET_32BIT(p
);
2272 sprintf(buf
, "Pageant has %d SSH1 keys", nkeys
);
2275 for (i
= 0; i
< nkeys
; i
++) {
2276 static struct RSAKey key
;
2277 static Bignum challenge
;
2278 static char *commentp
;
2279 static int commentlen
;
2283 sprintf(buf
, "Trying Pageant key #%d", i
);
2286 if (publickey_blob
&&
2287 !memcmp(p
, publickey_blob
, publickey_bloblen
)) {
2288 logevent("This key matches configured key file");
2289 tried_publickey
= 1;
2292 p
+= ssh1_read_bignum(p
, &key
.exponent
);
2293 p
+= ssh1_read_bignum(p
, &key
.modulus
);
2294 commentlen
= GET_32BIT(p
);
2298 send_packet(SSH1_CMSG_AUTH_RSA
,
2299 PKT_BIGNUM
, key
.modulus
, PKT_END
);
2301 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2302 logevent("Key refused");
2305 logevent("Received RSA challenge");
2306 ssh1_read_bignum(pktin
.body
, &challenge
);
2308 char *agentreq
, *q
, *ret
;
2311 len
= 1 + 4; /* message type, bit count */
2312 len
+= ssh1_bignum_length(key
.exponent
);
2313 len
+= ssh1_bignum_length(key
.modulus
);
2314 len
+= ssh1_bignum_length(challenge
);
2315 len
+= 16; /* session id */
2316 len
+= 4; /* response format */
2317 agentreq
= smalloc(4 + len
);
2318 PUT_32BIT(agentreq
, len
);
2320 *q
++ = SSH1_AGENTC_RSA_CHALLENGE
;
2321 PUT_32BIT(q
, bignum_bitcount(key
.modulus
));
2323 q
+= ssh1_write_bignum(q
, key
.exponent
);
2324 q
+= ssh1_write_bignum(q
, key
.modulus
);
2325 q
+= ssh1_write_bignum(q
, challenge
);
2326 memcpy(q
, session_id
, 16);
2328 PUT_32BIT(q
, 1); /* response format */
2329 agent_query(agentreq
, len
+ 4, &vret
, &retlen
);
2333 if (ret
[4] == SSH1_AGENT_RSA_RESPONSE
) {
2334 logevent("Sending Pageant's response");
2335 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
2336 PKT_DATA
, ret
+ 5, 16,
2340 if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
2342 ("Pageant's response accepted");
2343 if (flags
& FLAG_VERBOSE
) {
2345 ("Authenticated using RSA key \"");
2346 c_write(commentp
, commentlen
);
2347 c_write_str("\" from agent\r\n");
2352 ("Pageant's response not accepted");
2355 ("Pageant failed to answer challenge");
2359 logevent("No reply received from Pageant");
2362 freebn(key
.exponent
);
2363 freebn(key
.modulus
);
2372 if (*cfg
.keyfile
&& !tried_publickey
)
2373 pwpkt_type
= SSH1_CMSG_AUTH_RSA
;
2375 if (cfg
.try_tis_auth
&&
2376 (supported_auths_mask
& (1 << SSH1_AUTH_TIS
)) &&
2377 !tis_auth_refused
) {
2378 pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
2379 logevent("Requested TIS authentication");
2380 send_packet(SSH1_CMSG_AUTH_TIS
, PKT_END
);
2382 if (pktin
.type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
2383 logevent("TIS authentication declined");
2384 if (flags
& FLAG_INTERACTIVE
)
2385 c_write_str("TIS authentication refused.\r\n");
2386 tis_auth_refused
= 1;
2389 int challengelen
= ((pktin
.body
[0] << 24) |
2390 (pktin
.body
[1] << 16) |
2391 (pktin
.body
[2] << 8) |
2393 logevent("Received TIS challenge");
2394 if (challengelen
> sizeof(prompt
) - 1)
2395 challengelen
= sizeof(prompt
) - 1; /* prevent overrun */
2396 memcpy(prompt
, pktin
.body
+ 4, challengelen
);
2397 /* Prompt heuristic comes from OpenSSH */
2398 strncpy(prompt
+ challengelen
,
2399 memchr(prompt
, '\n', challengelen
) ?
2400 "": "\r\nResponse: ",
2401 (sizeof prompt
) - challengelen
);
2402 prompt
[(sizeof prompt
) - 1] = '\0';
2405 if (cfg
.try_tis_auth
&&
2406 (supported_auths_mask
& (1 << SSH1_AUTH_CCARD
)) &&
2407 !ccard_auth_refused
) {
2408 pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
2409 logevent("Requested CryptoCard authentication");
2410 send_packet(SSH1_CMSG_AUTH_CCARD
, PKT_END
);
2412 if (pktin
.type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
2413 logevent("CryptoCard authentication declined");
2414 c_write_str("CryptoCard authentication refused.\r\n");
2415 ccard_auth_refused
= 1;
2418 int challengelen
= ((pktin
.body
[0] << 24) |
2419 (pktin
.body
[1] << 16) |
2420 (pktin
.body
[2] << 8) |
2422 logevent("Received CryptoCard challenge");
2423 if (challengelen
> sizeof(prompt
) - 1)
2424 challengelen
= sizeof(prompt
) - 1; /* prevent overrun */
2425 memcpy(prompt
, pktin
.body
+ 4, challengelen
);
2426 strncpy(prompt
+ challengelen
,
2427 memchr(prompt
, '\n', challengelen
) ?
2428 "" : "\r\nResponse: ",
2429 sizeof(prompt
) - challengelen
);
2430 prompt
[sizeof(prompt
) - 1] = '\0';
2433 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2434 sprintf(prompt
, "%.90s@%.90s's password: ",
2435 username
, savedhost
);
2437 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2438 char *comment
= NULL
;
2441 if (flags
& FLAG_VERBOSE
)
2442 c_write_str("Trying public key authentication.\r\n");
2443 sprintf(msgbuf
, "Trying public key \"%.200s\"", cfg
.keyfile
);
2445 type
= key_type(cfg
.keyfile
);
2446 if (type
!= SSH_KEYTYPE_SSH1
) {
2447 sprintf(msgbuf
, "Key is of wrong type (%s)",
2448 key_type_to_str(type
));
2450 c_write_str(msgbuf
);
2451 c_write_str("\r\n");
2452 tried_publickey
= 1;
2455 if (!rsakey_encrypted(cfg
.keyfile
, &comment
)) {
2456 if (flags
& FLAG_VERBOSE
)
2457 c_write_str("No passphrase required.\r\n");
2460 sprintf(prompt
, "Passphrase for key \"%.100s\": ", comment
);
2465 * Show password prompt, having first obtained it via a TIS
2466 * or CryptoCard exchange if we're doing TIS or CryptoCard
2470 if (!ssh_get_line(prompt
, password
, sizeof(password
), TRUE
)) {
2472 * get_line failed to get a password (for example
2473 * because one was supplied on the command line
2474 * which has already failed to work). Terminate.
2476 send_packet(SSH1_MSG_DISCONNECT
,
2477 PKT_STR
, "No more passwords available to try",
2479 logevent("Unable to authenticate");
2480 connection_fatal("Unable to authenticate");
2481 ssh_state
= SSH_STATE_CLOSED
;
2485 /* Prompt may have come from server. We've munged it a bit, so
2486 * we know it to be zero-terminated at least once. */
2487 c_write_untrusted(prompt
, strlen(prompt
));
2491 crWaitUntil(!ispkt
);
2493 switch (c
= *in
++) {
2513 if (pos
< sizeof(password
)-1)
2514 password
[pos
++] = c
;
2518 c_write_str("\r\n");
2522 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2524 * Try public key authentication with the specified
2527 static struct RSAKey pubkey
;
2528 static Bignum challenge
, response
;
2530 static unsigned char buffer
[32];
2532 tried_publickey
= 1;
2533 i
= loadrsakey(cfg
.keyfile
, &pubkey
, password
);
2535 c_write_str("Couldn't load private key from ");
2536 c_write_str(cfg
.keyfile
);
2537 c_write_str(".\r\n");
2538 continue; /* go and try password */
2541 c_write_str("Wrong passphrase.\r\n");
2542 tried_publickey
= 0;
2543 continue; /* try again */
2547 * Send a public key attempt.
2549 send_packet(SSH1_CMSG_AUTH_RSA
,
2550 PKT_BIGNUM
, pubkey
.modulus
, PKT_END
);
2553 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2554 c_write_str("Server refused our public key.\r\n");
2555 continue; /* go and try password */
2557 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2558 bombout(("Bizarre response to offer of public key"));
2561 ssh1_read_bignum(pktin
.body
, &challenge
);
2562 response
= rsadecrypt(challenge
, &pubkey
);
2563 freebn(pubkey
.private_exponent
); /* burn the evidence */
2565 for (i
= 0; i
< 32; i
++) {
2566 buffer
[i
] = bignum_byte(response
, 31 - i
);
2570 MD5Update(&md5c
, buffer
, 32);
2571 MD5Update(&md5c
, session_id
, 16);
2572 MD5Final(buffer
, &md5c
);
2574 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
2575 PKT_DATA
, buffer
, 16, PKT_END
);
2578 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2579 if (flags
& FLAG_VERBOSE
)
2581 ("Failed to authenticate with our public key.\r\n");
2582 continue; /* go and try password */
2583 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2585 ("Bizarre response to RSA authentication response"));
2589 break; /* we're through! */
2591 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2593 * Defence against traffic analysis: we send a
2594 * whole bunch of packets containing strings of
2595 * different lengths. One of these strings is the
2596 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2597 * The others are all random data in
2598 * SSH1_MSG_IGNORE packets. This way a passive
2599 * listener can't tell which is the password, and
2600 * hence can't deduce the password length.
2602 * Anybody with a password length greater than 16
2603 * bytes is going to have enough entropy in their
2604 * password that a listener won't find it _that_
2605 * much help to know how long it is. So what we'll
2608 * - if password length < 16, we send 15 packets
2609 * containing string lengths 1 through 15
2611 * - otherwise, we let N be the nearest multiple
2612 * of 8 below the password length, and send 8
2613 * packets containing string lengths N through
2614 * N+7. This won't obscure the order of
2615 * magnitude of the password length, but it will
2616 * introduce a bit of extra uncertainty.
2618 * A few servers (the old 1.2.18 through 1.2.22)
2619 * can't deal with SSH1_MSG_IGNORE. For these
2620 * servers, we need an alternative defence. We make
2621 * use of the fact that the password is interpreted
2622 * as a C string: so we can append a NUL, then some
2625 * One server (a Cisco one) can deal with neither
2626 * SSH1_MSG_IGNORE _nor_ a padded password string.
2627 * For this server we are left with no defences
2628 * against password length sniffing.
2630 if (!(ssh_remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
)) {
2632 * The server can deal with SSH1_MSG_IGNORE, so
2633 * we can use the primary defence.
2635 int bottom
, top
, pwlen
, i
;
2638 pwlen
= strlen(password
);
2640 bottom
= 0; /* zero length passwords are OK! :-) */
2643 bottom
= pwlen
& ~7;
2647 assert(pwlen
>= bottom
&& pwlen
<= top
);
2649 randomstr
= smalloc(top
+ 1);
2651 for (i
= bottom
; i
<= top
; i
++) {
2653 defer_packet(pwpkt_type
, PKT_STR
, password
,
2656 for (j
= 0; j
< i
; j
++) {
2658 randomstr
[j
] = random_byte();
2659 } while (randomstr
[j
] == '\0');
2661 randomstr
[i
] = '\0';
2662 defer_packet(SSH1_MSG_IGNORE
,
2663 PKT_STR
, randomstr
, PKT_END
);
2666 logevent("Sending password with camouflage packets");
2667 ssh_pkt_defersend();
2669 else if (!(ssh_remote_bugs
& BUG_NEEDS_SSH1_PLAIN_PASSWORD
)) {
2671 * The server can't deal with SSH1_MSG_IGNORE
2672 * but can deal with padded passwords, so we
2673 * can use the secondary defence.
2679 len
= strlen(password
);
2680 if (len
< sizeof(string
)) {
2682 strcpy(string
, password
);
2683 len
++; /* cover the zero byte */
2684 while (len
< sizeof(string
)) {
2685 string
[len
++] = (char) random_byte();
2690 logevent("Sending length-padded password");
2691 send_packet(pwpkt_type
, PKT_INT
, len
,
2692 PKT_DATA
, s
, len
, PKT_END
);
2695 * The server has _both_
2696 * BUG_CHOKES_ON_SSH1_IGNORE and
2697 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2698 * therefore nothing we can do.
2701 len
= strlen(password
);
2702 logevent("Sending unpadded password");
2703 send_packet(pwpkt_type
, PKT_INT
, len
,
2704 PKT_DATA
, password
, len
, PKT_END
);
2707 send_packet(pwpkt_type
, PKT_STR
, password
, PKT_END
);
2710 logevent("Sent password");
2711 memset(password
, 0, strlen(password
));
2713 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2714 if (flags
& FLAG_VERBOSE
)
2715 c_write_str("Access denied\r\n");
2716 logevent("Authentication refused");
2717 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
2718 logevent("Received disconnect request");
2719 ssh_state
= SSH_STATE_CLOSED
;
2721 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2722 bombout(("Strange packet received, type %d", pktin
.type
));
2727 logevent("Authentication successful");
2732 void sshfwd_close(struct ssh_channel
*c
)
2734 if (c
&& !c
->closes
) {
2736 * If the channel's remoteid is -1, we have sent
2737 * CHANNEL_OPEN for this channel, but it hasn't even been
2738 * acknowledged by the server. So we must set a close flag
2739 * on it now, and then when the server acks the channel
2740 * open, we can close it then.
2742 if (c
->remoteid
!= -1) {
2743 if (ssh_version
== 1) {
2744 send_packet(SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
2747 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
2748 ssh2_pkt_adduint32(c
->remoteid
);
2753 if (c
->type
== CHAN_X11
) {
2755 logevent("Forwarded X11 connection terminated");
2756 } else if (c
->type
== CHAN_SOCKDATA
||
2757 c
->type
== CHAN_SOCKDATA_DORMANT
) {
2759 logevent("Forwarded port closed");
2764 int sshfwd_write(struct ssh_channel
*c
, char *buf
, int len
)
2766 if (ssh_version
== 1) {
2767 send_packet(SSH1_MSG_CHANNEL_DATA
,
2768 PKT_INT
, c
->remoteid
,
2769 PKT_INT
, len
, PKT_DATA
, buf
, len
, PKT_END
);
2771 * In SSH1 we can return 0 here - implying that forwarded
2772 * connections are never individually throttled - because
2773 * the only circumstance that can cause throttling will be
2774 * the whole SSH connection backing up, in which case
2775 * _everything_ will be throttled as a whole.
2779 ssh2_add_channel_data(c
, buf
, len
);
2780 return ssh2_try_send(c
);
2784 void sshfwd_unthrottle(struct ssh_channel
*c
, int bufsize
)
2786 if (ssh_version
== 1) {
2787 if (c
->v
.v1
.throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
2788 c
->v
.v1
.throttling
= 0;
2792 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
2796 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
)
2802 while (!do_ssh1_login(in
, inlen
, ispkt
)) {
2805 if (ssh_state
== SSH_STATE_CLOSED
)
2808 if (cfg
.agentfwd
&& agent_exists()) {
2809 logevent("Requesting agent forwarding");
2810 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
2814 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2815 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2816 bombout(("Protocol confusion"));
2818 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2819 logevent("Agent forwarding refused");
2821 logevent("Agent forwarding enabled");
2822 ssh_agentfwd_enabled
= TRUE
;
2826 if (cfg
.x11_forward
) {
2827 char proto
[20], data
[64];
2828 logevent("Requesting X11 forwarding");
2829 x11_invent_auth(proto
, sizeof(proto
), data
, sizeof(data
));
2830 if (ssh1_local_protoflags
& SSH1_PROTOFLAG_SCREEN_NUMBER
) {
2831 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING
,
2832 PKT_STR
, proto
, PKT_STR
, data
,
2833 PKT_INT
, 0, PKT_END
);
2835 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING
,
2836 PKT_STR
, proto
, PKT_STR
, data
, PKT_END
);
2841 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2842 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2843 bombout(("Protocol confusion"));
2845 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2846 logevent("X11 forwarding refused");
2848 logevent("X11 forwarding enabled");
2849 ssh_X11_fwd_enabled
= TRUE
;
2857 int sport
,dport
,sserv
,dserv
;
2858 char sports
[256], dports
[256], host
[256];
2862 ssh_rportfwds
= newtree234(ssh_rportcmp_ssh1
);
2863 /* Add port forwardings. */
2868 while (*e
&& *e
!= '\t')
2874 while (*e
&& *e
!= ':')
2884 dport
= atoi(dports
);
2888 se
= getservbyname(dports
, NULL
);
2890 dport
= ntohs(se
->s_port
);
2893 "Service lookup failed for destination port \"%s\"",
2898 sport
= atoi(sports
);
2902 se
= getservbyname(sports
, NULL
);
2904 sport
= ntohs(se
->s_port
);
2907 "Service lookup failed for source port \"%s\"",
2912 if (sport
&& dport
) {
2914 pfd_addforward(host
, dport
, sport
);
2915 sprintf(buf
, "Local port %.*s%.*s%d%.*s forwarding to"
2916 " %s:%.*s%.*s%d%.*s",
2917 sserv ?
strlen(sports
) : 0, sports
,
2918 sserv
, "(", sport
, sserv
, ")",
2920 dserv ?
strlen(dports
) : 0, dports
,
2921 dserv
, "(", dport
, dserv
, ")");
2924 struct ssh_rportfwd
*pf
;
2925 pf
= smalloc(sizeof(*pf
));
2926 strcpy(pf
->dhost
, host
);
2928 if (add234(ssh_rportfwds
, pf
) != pf
) {
2930 "Duplicate remote port forwarding to %s:%d",
2935 sprintf(buf
, "Requesting remote port %.*s%.*s%d%.*s"
2936 " forward to %s:%.*s%.*s%d%.*s",
2937 sserv ?
strlen(sports
) : 0, sports
,
2938 sserv
, "(", sport
, sserv
, ")",
2940 dserv ?
strlen(dports
) : 0, dports
,
2941 dserv
, "(", dport
, dserv
, ")");
2943 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST
,
2951 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2952 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2953 bombout(("Protocol confusion"));
2955 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2956 c_write_str("Server refused port forwarding\r\n");
2957 ssh_editing
= ssh_echoing
= 1;
2959 logevent("Remote port forwarding enabled");
2967 send_packet(SSH1_CMSG_REQUEST_PTY
,
2968 PKT_STR
, cfg
.termtype
,
2969 PKT_INT
, rows
, PKT_INT
, cols
,
2970 PKT_INT
, 0, PKT_INT
, 0, PKT_CHAR
, 0, PKT_END
);
2971 ssh_state
= SSH_STATE_INTERMED
;
2975 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2976 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2977 bombout(("Protocol confusion"));
2979 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2980 c_write_str("Server refused to allocate pty\r\n");
2981 ssh_editing
= ssh_echoing
= 1;
2983 logevent("Allocated pty");
2985 ssh_editing
= ssh_echoing
= 1;
2988 if (cfg
.compression
) {
2989 send_packet(SSH1_CMSG_REQUEST_COMPRESSION
, PKT_INT
, 6, PKT_END
);
2993 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2994 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2995 bombout(("Protocol confusion"));
2997 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2998 c_write_str("Server refused to compress\r\n");
3000 logevent("Started compression");
3001 ssh1_compressing
= TRUE
;
3002 zlib_compress_init();
3003 zlib_decompress_init();
3007 * Start the shell or command.
3009 * Special case: if the first-choice command is an SSH2
3010 * subsystem (hence not usable here) and the second choice
3011 * exists, we fall straight back to that.
3014 char *cmd
= cfg
.remote_cmd_ptr
;
3016 if (cfg
.ssh_subsys
&& cfg
.remote_cmd_ptr2
) {
3017 cmd
= cfg
.remote_cmd_ptr2
;
3018 ssh_fallback_cmd
= TRUE
;
3021 send_packet(SSH1_CMSG_EXEC_CMD
, PKT_STR
, cmd
, PKT_END
);
3023 send_packet(SSH1_CMSG_EXEC_SHELL
, PKT_END
);
3024 logevent("Started session");
3027 ssh_state
= SSH_STATE_SESSION
;
3031 ssh_special(TS_EOF
);
3033 ldisc_send(NULL
, 0, 0); /* cause ldisc to notice changes */
3035 ssh_channels
= newtree234(ssh_channelcmp
);
3039 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
3040 pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
3041 long len
= GET_32BIT(pktin
.body
);
3043 from_backend(pktin
.type
== SSH1_SMSG_STDERR_DATA
,
3044 pktin
.body
+ 4, len
);
3045 if (!ssh1_stdout_throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
3046 ssh1_stdout_throttling
= 1;
3049 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
3050 ssh_state
= SSH_STATE_CLOSED
;
3051 logevent("Received disconnect request");
3053 } else if (pktin
.type
== SSH1_SMSG_X11_OPEN
) {
3054 /* Remote side is trying to open a channel to talk to our
3055 * X-Server. Give them back a local channel number. */
3056 struct ssh_channel
*c
;
3058 logevent("Received X11 connect request");
3059 /* Refuse if X11 forwarding is disabled. */
3060 if (!ssh_X11_fwd_enabled
) {
3061 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3062 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
3063 logevent("Rejected X11 connect request");
3065 c
= smalloc(sizeof(struct ssh_channel
));
3067 if (x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
) != NULL
) {
3068 logevent("opening X11 forward connection failed");
3070 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3071 PKT_INT
, GET_32BIT(pktin
.body
),
3075 ("opening X11 forward connection succeeded");
3076 c
->remoteid
= GET_32BIT(pktin
.body
);
3077 c
->localid
= alloc_channel_id();
3079 c
->v
.v1
.throttling
= 0;
3080 c
->type
= CHAN_X11
; /* identify channel type */
3081 add234(ssh_channels
, c
);
3082 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3083 PKT_INT
, c
->remoteid
, PKT_INT
,
3084 c
->localid
, PKT_END
);
3085 logevent("Opened X11 forward channel");
3088 } else if (pktin
.type
== SSH1_SMSG_AGENT_OPEN
) {
3089 /* Remote side is trying to open a channel to talk to our
3090 * agent. Give them back a local channel number. */
3091 struct ssh_channel
*c
;
3093 /* Refuse if agent forwarding is disabled. */
3094 if (!ssh_agentfwd_enabled
) {
3095 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3096 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
3098 c
= smalloc(sizeof(struct ssh_channel
));
3099 c
->remoteid
= GET_32BIT(pktin
.body
);
3100 c
->localid
= alloc_channel_id();
3102 c
->v
.v1
.throttling
= 0;
3103 c
->type
= CHAN_AGENT
; /* identify channel type */
3104 c
->u
.a
.lensofar
= 0;
3105 add234(ssh_channels
, c
);
3106 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3107 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
3110 } else if (pktin
.type
== SSH1_MSG_PORT_OPEN
) {
3111 /* Remote side is trying to open a channel to talk to a
3112 * forwarded port. Give them back a local channel number. */
3113 struct ssh_channel
*c
;
3114 struct ssh_rportfwd pf
;
3116 char host
[256], buf
[1024];
3118 c
= smalloc(sizeof(struct ssh_channel
));
3120 hostsize
= GET_32BIT(pktin
.body
+4);
3121 for(h
= host
, p
= pktin
.body
+8; hostsize
!= 0; hostsize
--) {
3122 if (h
+1 < host
+sizeof(host
))
3127 port
= GET_32BIT(p
);
3129 strcpy(pf
.dhost
, host
);
3132 if (find234(ssh_rportfwds
, &pf
, NULL
) == NULL
) {
3133 sprintf(buf
, "Rejected remote port open request for %s:%d",
3136 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3137 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
3139 sprintf(buf
, "Received remote port open request for %s:%d",
3142 e
= pfd_newconnect(&c
->u
.pfd
.s
, host
, port
, c
);
3145 sprintf(buf
, "Port open failed: %s", e
);
3148 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3149 PKT_INT
, GET_32BIT(pktin
.body
),
3152 c
->remoteid
= GET_32BIT(pktin
.body
);
3153 c
->localid
= alloc_channel_id();
3155 c
->v
.v1
.throttling
= 0;
3156 c
->type
= CHAN_SOCKDATA
; /* identify channel type */
3157 add234(ssh_channels
, c
);
3158 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3159 PKT_INT
, c
->remoteid
, PKT_INT
,
3160 c
->localid
, PKT_END
);
3161 logevent("Forwarded port opened successfully");
3165 } else if (pktin
.type
== SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
) {
3166 unsigned int remoteid
= GET_32BIT(pktin
.body
);
3167 unsigned int localid
= GET_32BIT(pktin
.body
+4);
3168 struct ssh_channel
*c
;
3170 c
= find234(ssh_channels
, &remoteid
, ssh_channelfind
);
3171 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
3172 c
->remoteid
= localid
;
3173 c
->type
= CHAN_SOCKDATA
;
3174 c
->v
.v1
.throttling
= 0;
3175 pfd_confirm(c
->u
.pfd
.s
);
3178 if (c
&& c
->closes
) {
3180 * We have a pending close on this channel,
3181 * which we decided on before the server acked
3182 * the channel open. So now we know the
3183 * remoteid, we can close it again.
3185 send_packet(SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
3189 } else if (pktin
.type
== SSH1_MSG_CHANNEL_OPEN_FAILURE
) {
3190 unsigned int remoteid
= GET_32BIT(pktin
.body
);
3191 unsigned int localid
= GET_32BIT(pktin
.body
+4);
3192 struct ssh_channel
*c
;
3194 c
= find234(ssh_channels
, &remoteid
, ssh_channelfind
);
3195 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
3196 logevent("Forwarded connection refused by server");
3197 pfd_close(c
->u
.pfd
.s
);
3198 del234(ssh_channels
, c
);
3202 } else if (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE
||
3203 pktin
.type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
) {
3204 /* Remote side closes a channel. */
3205 unsigned i
= GET_32BIT(pktin
.body
);
3206 struct ssh_channel
*c
;
3207 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
3211 (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
1 : 2);
3212 if (!(c
->closes
& closetype
))
3213 send_packet(pktin
.type
, PKT_INT
, c
->remoteid
,
3215 if ((c
->closes
== 0) && (c
->type
== CHAN_X11
)) {
3216 logevent("Forwarded X11 connection terminated");
3217 assert(c
->u
.x11
.s
!= NULL
);
3218 x11_close(c
->u
.x11
.s
);
3221 if ((c
->closes
== 0) && (c
->type
== CHAN_SOCKDATA
)) {
3222 logevent("Forwarded port closed");
3223 assert(c
->u
.pfd
.s
!= NULL
);
3224 pfd_close(c
->u
.pfd
.s
);
3227 c
->closes
|= closetype
;
3228 if (c
->closes
== 3) {
3229 del234(ssh_channels
, c
);
3233 } else if (pktin
.type
== SSH1_MSG_CHANNEL_DATA
) {
3234 /* Data sent down one of our channels. */
3235 int i
= GET_32BIT(pktin
.body
);
3236 int len
= GET_32BIT(pktin
.body
+ 4);
3237 unsigned char *p
= pktin
.body
+ 8;
3238 struct ssh_channel
*c
;
3239 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
3244 bufsize
= x11_send(c
->u
.x11
.s
, p
, len
);
3247 bufsize
= pfd_send(c
->u
.pfd
.s
, p
, len
);
3250 /* Data for an agent message. Buffer it. */
3252 if (c
->u
.a
.lensofar
< 4) {
3253 int l
= min(4 - c
->u
.a
.lensofar
, len
);
3254 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
,
3258 c
->u
.a
.lensofar
+= l
;
3260 if (c
->u
.a
.lensofar
== 4) {
3262 4 + GET_32BIT(c
->u
.a
.msglen
);
3263 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
3264 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
3266 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
3268 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
3270 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
,
3274 c
->u
.a
.lensofar
+= l
;
3276 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
3277 void *reply
, *sentreply
;
3279 agent_query(c
->u
.a
.message
,
3280 c
->u
.a
.totallen
, &reply
,
3285 /* Fake SSH_AGENT_FAILURE. */
3286 sentreply
= "\0\0\0\1\5";
3289 send_packet(SSH1_MSG_CHANNEL_DATA
,
3290 PKT_INT
, c
->remoteid
,
3292 PKT_DATA
, sentreply
, replylen
,
3296 sfree(c
->u
.a
.message
);
3297 c
->u
.a
.lensofar
= 0;
3300 bufsize
= 0; /* agent channels never back up */
3303 if (!c
->v
.v1
.throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
3304 c
->v
.v1
.throttling
= 1;
3308 } else if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
3309 /* may be from EXEC_SHELL on some servers */
3310 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
3311 /* may be from EXEC_SHELL on some servers
3312 * if no pty is available or in other odd cases. Ignore */
3313 } else if (pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
3315 ssh_exitcode
= GET_32BIT(pktin
.body
);
3316 sprintf(buf
, "Server sent command exit status %d",
3319 send_packet(SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
3321 * In case `helpful' firewalls or proxies tack
3322 * extra human-readable text on the end of the
3323 * session which we might mistake for another
3324 * encrypted packet, we close the session once
3325 * we've sent EXIT_CONFIRMATION.
3327 ssh_state
= SSH_STATE_CLOSED
;
3330 bombout(("Strange packet received: type %d", pktin
.type
));
3335 int len
= min(inlen
, 512);
3336 send_packet(SSH1_CMSG_STDIN_DATA
,
3337 PKT_INT
, len
, PKT_DATA
, in
, len
, PKT_END
);
3348 * Utility routine for decoding comma-separated strings in KEXINIT.
3350 static int in_commasep_string(char *needle
, char *haystack
, int haylen
)
3352 int needlen
= strlen(needle
);
3355 * Is it at the start of the string?
3357 if (haylen
>= needlen
&& /* haystack is long enough */
3358 !memcmp(needle
, haystack
, needlen
) && /* initial match */
3359 (haylen
== needlen
|| haystack
[needlen
] == ',')
3360 /* either , or EOS follows */
3364 * If not, search for the next comma and resume after that.
3365 * If no comma found, terminate.
3367 while (haylen
> 0 && *haystack
!= ',')
3368 haylen
--, haystack
++;
3371 haylen
--, haystack
++; /* skip over comma itself */
3376 * SSH2 key creation method.
3378 static void ssh2_mkkey(Bignum K
, char *H
, char *sessid
, char chr
,
3382 /* First 20 bytes. */
3385 SHA_Bytes(&s
, H
, 20);
3386 SHA_Bytes(&s
, &chr
, 1);
3387 SHA_Bytes(&s
, sessid
, 20);
3388 SHA_Final(&s
, keyspace
);
3389 /* Next 20 bytes. */
3392 SHA_Bytes(&s
, H
, 20);
3393 SHA_Bytes(&s
, keyspace
, 20);
3394 SHA_Final(&s
, keyspace
+ 20);
3398 * Handle the SSH2 transport layer.
3400 static int do_ssh2_transport(unsigned char *in
, int inlen
, int ispkt
)
3402 static int i
, j
, len
, nbits
, pbits
, warn
;
3404 static Bignum p
, g
, e
, f
, K
;
3405 static int kex_init_value
, kex_reply_value
;
3406 static const struct ssh_mac
**maclist
;
3408 static const struct ssh2_cipher
*cscipher_tobe
= NULL
;
3409 static const struct ssh2_cipher
*sccipher_tobe
= NULL
;
3410 static const struct ssh_mac
*csmac_tobe
= NULL
;
3411 static const struct ssh_mac
*scmac_tobe
= NULL
;
3412 static const struct ssh_compress
*cscomp_tobe
= NULL
;
3413 static const struct ssh_compress
*sccomp_tobe
= NULL
;
3414 static char *hostkeydata
, *sigdata
, *keystr
, *fingerprint
;
3415 static int hostkeylen
, siglen
;
3416 static void *hkey
; /* actual host key */
3417 static unsigned char exchange_hash
[20];
3418 static unsigned char keyspace
[40];
3419 static int n_preferred_ciphers
;
3420 static const struct ssh2_ciphers
*preferred_ciphers
[CIPHER_MAX
];
3421 static const struct ssh_compress
*preferred_comp
;
3422 static int cipherstr_started
;
3423 static int first_kex
;
3430 * Set up the preferred ciphers. (NULL => warn below here)
3432 n_preferred_ciphers
= 0;
3433 for (i
= 0; i
< CIPHER_MAX
; i
++) {
3434 switch (cfg
.ssh_cipherlist
[i
]) {
3435 case CIPHER_BLOWFISH
:
3436 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_blowfish
;
3437 n_preferred_ciphers
++;
3440 if (cfg
.ssh2_des_cbc
) {
3441 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_des
;
3442 n_preferred_ciphers
++;
3446 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_3des
;
3447 n_preferred_ciphers
++;
3450 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_aes
;
3451 n_preferred_ciphers
++;
3454 /* Flag for later. Don't bother if it's the last in
3456 if (i
< CIPHER_MAX
- 1) {
3457 preferred_ciphers
[n_preferred_ciphers
] = NULL
;
3458 n_preferred_ciphers
++;
3465 * Set up preferred compression.
3467 if (cfg
.compression
)
3468 preferred_comp
= &ssh_zlib
;
3470 preferred_comp
= &ssh_comp_none
;
3473 * Be prepared to work around the buggy MAC problem.
3475 if (cfg
.buggymac
|| (ssh_remote_bugs
& BUG_SSH2_HMAC
))
3476 maclist
= buggymacs
, nmacs
= lenof(buggymacs
);
3478 maclist
= macs
, nmacs
= lenof(macs
);
3482 * Construct and send our key exchange packet.
3484 ssh2_pkt_init(SSH2_MSG_KEXINIT
);
3485 for (i
= 0; i
< 16; i
++)
3486 ssh2_pkt_addbyte((unsigned char) random_byte());
3487 /* List key exchange algorithms. */
3488 ssh2_pkt_addstring_start();
3489 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3490 ssh2_pkt_addstring_str(kex_algs
[i
]->name
);
3491 if (i
< lenof(kex_algs
) - 1)
3492 ssh2_pkt_addstring_str(",");
3494 /* List server host key algorithms. */
3495 ssh2_pkt_addstring_start();
3496 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3497 ssh2_pkt_addstring_str(hostkey_algs
[i
]->name
);
3498 if (i
< lenof(hostkey_algs
) - 1)
3499 ssh2_pkt_addstring_str(",");
3501 /* List client->server encryption algorithms. */
3502 ssh2_pkt_addstring_start();
3503 cipherstr_started
= 0;
3504 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3505 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3506 if (!c
) continue; /* warning flag */
3507 for (j
= 0; j
< c
->nciphers
; j
++) {
3508 if (cipherstr_started
)
3509 ssh2_pkt_addstring_str(",");
3510 ssh2_pkt_addstring_str(c
->list
[j
]->name
);
3511 cipherstr_started
= 1;
3514 /* List server->client encryption algorithms. */
3515 ssh2_pkt_addstring_start();
3516 cipherstr_started
= 0;
3517 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3518 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3519 if (!c
) continue; /* warning flag */
3520 for (j
= 0; j
< c
->nciphers
; j
++) {
3521 if (cipherstr_started
)
3522 ssh2_pkt_addstring_str(",");
3523 ssh2_pkt_addstring_str(c
->list
[j
]->name
);
3524 cipherstr_started
= 1;
3527 /* List client->server MAC algorithms. */
3528 ssh2_pkt_addstring_start();
3529 for (i
= 0; i
< nmacs
; i
++) {
3530 ssh2_pkt_addstring_str(maclist
[i
]->name
);
3532 ssh2_pkt_addstring_str(",");
3534 /* List server->client MAC algorithms. */
3535 ssh2_pkt_addstring_start();
3536 for (i
= 0; i
< nmacs
; i
++) {
3537 ssh2_pkt_addstring_str(maclist
[i
]->name
);
3539 ssh2_pkt_addstring_str(",");
3541 /* List client->server compression algorithms. */
3542 ssh2_pkt_addstring_start();
3543 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3544 const struct ssh_compress
*c
=
3545 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3546 ssh2_pkt_addstring_str(c
->name
);
3547 if (i
< lenof(compressions
))
3548 ssh2_pkt_addstring_str(",");
3550 /* List server->client compression algorithms. */
3551 ssh2_pkt_addstring_start();
3552 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3553 const struct ssh_compress
*c
=
3554 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3555 ssh2_pkt_addstring_str(c
->name
);
3556 if (i
< lenof(compressions
))
3557 ssh2_pkt_addstring_str(",");
3559 /* List client->server languages. Empty list. */
3560 ssh2_pkt_addstring_start();
3561 /* List server->client languages. Empty list. */
3562 ssh2_pkt_addstring_start();
3563 /* First KEX packet does _not_ follow, because we're not that brave. */
3564 ssh2_pkt_addbool(FALSE
);
3566 ssh2_pkt_adduint32(0);
3568 exhash
= exhashbase
;
3569 sha_string(&exhash
, pktout
.data
+ 5, pktout
.length
- 5);
3575 sha_string(&exhash
, pktin
.data
+ 5, pktin
.length
- 5);
3578 * Now examine the other side's KEXINIT to see what we're up
3581 if (pktin
.type
!= SSH2_MSG_KEXINIT
) {
3582 bombout(("expected key exchange packet from server"));
3587 cscipher_tobe
= NULL
;
3588 sccipher_tobe
= NULL
;
3593 pktin
.savedpos
+= 16; /* skip garbage cookie */
3594 ssh2_pkt_getstring(&str
, &len
); /* key exchange algorithms */
3595 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3596 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
3601 ssh2_pkt_getstring(&str
, &len
); /* host key algorithms */
3602 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3603 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
3604 hostkey
= hostkey_algs
[i
];
3608 ssh2_pkt_getstring(&str
, &len
); /* client->server cipher */
3610 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3611 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3615 for (j
= 0; j
< c
->nciphers
; j
++) {
3616 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3617 cscipher_tobe
= c
->list
[j
];
3622 if (cscipher_tobe
) {
3624 askcipher(cscipher_tobe
->name
, 1);
3628 if (!cscipher_tobe
) {
3629 bombout(("Couldn't agree a client-to-server cipher (available: %s)", str
));
3633 ssh2_pkt_getstring(&str
, &len
); /* server->client cipher */
3635 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3636 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3640 for (j
= 0; j
< c
->nciphers
; j
++) {
3641 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3642 sccipher_tobe
= c
->list
[j
];
3647 if (sccipher_tobe
) {
3649 askcipher(sccipher_tobe
->name
, 2);
3653 if (!sccipher_tobe
) {
3654 bombout(("Couldn't agree a server-to-client cipher (available: %s)", str
));
3658 ssh2_pkt_getstring(&str
, &len
); /* client->server mac */
3659 for (i
= 0; i
< nmacs
; i
++) {
3660 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
3661 csmac_tobe
= maclist
[i
];
3665 ssh2_pkt_getstring(&str
, &len
); /* server->client mac */
3666 for (i
= 0; i
< nmacs
; i
++) {
3667 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
3668 scmac_tobe
= maclist
[i
];
3672 ssh2_pkt_getstring(&str
, &len
); /* client->server compression */
3673 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3674 const struct ssh_compress
*c
=
3675 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3676 if (in_commasep_string(c
->name
, str
, len
)) {
3681 ssh2_pkt_getstring(&str
, &len
); /* server->client compression */
3682 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3683 const struct ssh_compress
*c
=
3684 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3685 if (in_commasep_string(c
->name
, str
, len
)) {
3692 * Work out the number of bits of key we will need from the key
3693 * exchange. We start with the maximum key length of either
3699 csbits
= cscipher_tobe
->keylen
;
3700 scbits
= sccipher_tobe
->keylen
;
3701 nbits
= (csbits
> scbits ? csbits
: scbits
);
3703 /* The keys only have 160-bit entropy, since they're based on
3704 * a SHA-1 hash. So cap the key size at 160 bits. */
3709 * If we're doing Diffie-Hellman group exchange, start by
3710 * requesting a group.
3712 if (kex
== &ssh_diffiehellman_gex
) {
3713 logevent("Doing Diffie-Hellman group exchange");
3714 ssh_pkt_ctx
|= SSH2_PKTCTX_DHGEX
;
3716 * Work out how big a DH group we will need to allow that
3719 pbits
= 512 << ((nbits
- 1) / 64);
3720 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST
);
3721 ssh2_pkt_adduint32(pbits
);
3725 if (pktin
.type
!= SSH2_MSG_KEX_DH_GEX_GROUP
) {
3726 bombout(("expected key exchange group packet from server"));
3729 p
= ssh2_pkt_getmp();
3730 g
= ssh2_pkt_getmp();
3731 dh_setup_group(p
, g
);
3732 kex_init_value
= SSH2_MSG_KEX_DH_GEX_INIT
;
3733 kex_reply_value
= SSH2_MSG_KEX_DH_GEX_REPLY
;
3735 ssh_pkt_ctx
|= SSH2_PKTCTX_DHGROUP1
;
3737 kex_init_value
= SSH2_MSG_KEXDH_INIT
;
3738 kex_reply_value
= SSH2_MSG_KEXDH_REPLY
;
3741 logevent("Doing Diffie-Hellman key exchange");
3743 * Now generate and send e for Diffie-Hellman.
3745 e
= dh_create_e(nbits
* 2);
3746 ssh2_pkt_init(kex_init_value
);
3751 if (pktin
.type
!= kex_reply_value
) {
3752 bombout(("expected key exchange reply packet from server"));
3755 ssh2_pkt_getstring(&hostkeydata
, &hostkeylen
);
3756 f
= ssh2_pkt_getmp();
3757 ssh2_pkt_getstring(&sigdata
, &siglen
);
3761 sha_string(&exhash
, hostkeydata
, hostkeylen
);
3762 if (kex
== &ssh_diffiehellman_gex
) {
3763 sha_uint32(&exhash
, pbits
);
3764 sha_mpint(&exhash
, p
);
3765 sha_mpint(&exhash
, g
);
3767 sha_mpint(&exhash
, e
);
3768 sha_mpint(&exhash
, f
);
3769 sha_mpint(&exhash
, K
);
3770 SHA_Final(&exhash
, exchange_hash
);
3775 debug(("Exchange hash is:\n"));
3776 dmemdump(exchange_hash
, 20);
3779 hkey
= hostkey
->newkey(hostkeydata
, hostkeylen
);
3781 !hostkey
->verifysig(hkey
, sigdata
, siglen
, exchange_hash
, 20)) {
3782 bombout(("Server's host key did not match the signature supplied"));
3787 * Authenticate remote host: verify host key. (We've already
3788 * checked the signature of the exchange hash.)
3790 keystr
= hostkey
->fmtkey(hkey
);
3791 fingerprint
= hostkey
->fingerprint(hkey
);
3792 verify_ssh_host_key(savedhost
, savedport
, hostkey
->keytype
,
3793 keystr
, fingerprint
);
3794 if (first_kex
) { /* don't bother logging this in rekeys */
3795 logevent("Host key fingerprint is:");
3796 logevent(fingerprint
);
3800 hostkey
->freekey(hkey
);
3803 * Send SSH2_MSG_NEWKEYS.
3805 ssh2_pkt_init(SSH2_MSG_NEWKEYS
);
3809 * Expect SSH2_MSG_NEWKEYS from server.
3812 if (pktin
.type
!= SSH2_MSG_NEWKEYS
) {
3813 bombout(("expected new-keys packet from server"));
3818 * Create and initialise session keys.
3820 cscipher
= cscipher_tobe
;
3821 sccipher
= sccipher_tobe
;
3824 cscomp
= cscomp_tobe
;
3825 sccomp
= sccomp_tobe
;
3826 cscomp
->compress_init();
3827 sccomp
->decompress_init();
3829 * Set IVs after keys. Here we use the exchange hash from the
3830 * _first_ key exchange.
3833 memcpy(ssh2_session_id
, exchange_hash
, sizeof(exchange_hash
));
3834 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'C', keyspace
);
3835 cscipher
->setcskey(keyspace
);
3836 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'D', keyspace
);
3837 sccipher
->setsckey(keyspace
);
3838 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'A', keyspace
);
3839 cscipher
->setcsiv(keyspace
);
3840 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'B', keyspace
);
3841 sccipher
->setsciv(keyspace
);
3842 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'E', keyspace
);
3843 csmac
->setcskey(keyspace
);
3844 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'F', keyspace
);
3845 scmac
->setsckey(keyspace
);
3848 * If this is the first key exchange phase, we must pass the
3849 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3850 * wants to see it but because it will need time to initialise
3851 * itself before it sees an actual packet. In subsequent key
3852 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3853 * it would only confuse the layer above.
3861 * Now we're encrypting. Begin returning 1 to the protocol main
3862 * function so that other things can run on top of the
3863 * transport. If we ever see a KEXINIT, we must go back to the
3866 while (!(ispkt
&& pktin
.type
== SSH2_MSG_KEXINIT
)) {
3869 logevent("Server initiated key re-exchange");
3870 goto begin_key_exchange
;
3876 * Add data to an SSH2 channel output buffer.
3878 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
3881 bufchain_add(&c
->v
.v2
.outbuffer
, buf
, len
);
3885 * Attempt to send data on an SSH2 channel.
3887 static int ssh2_try_send(struct ssh_channel
*c
)
3889 while (c
->v
.v2
.remwindow
> 0 && bufchain_size(&c
->v
.v2
.outbuffer
) > 0) {
3892 bufchain_prefix(&c
->v
.v2
.outbuffer
, &data
, &len
);
3893 if ((unsigned)len
> c
->v
.v2
.remwindow
)
3894 len
= c
->v
.v2
.remwindow
;
3895 if ((unsigned)len
> c
->v
.v2
.remmaxpkt
)
3896 len
= c
->v
.v2
.remmaxpkt
;
3897 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA
);
3898 ssh2_pkt_adduint32(c
->remoteid
);
3899 ssh2_pkt_addstring_start();
3900 ssh2_pkt_addstring_data(data
, len
);
3902 bufchain_consume(&c
->v
.v2
.outbuffer
, len
);
3903 c
->v
.v2
.remwindow
-= len
;
3907 * After having sent as much data as we can, return the amount
3910 return bufchain_size(&c
->v
.v2
.outbuffer
);
3914 * Potentially enlarge the window on an SSH2 channel.
3916 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
)
3919 * Never send WINDOW_ADJUST for a channel that the remote side
3920 * already thinks it's closed; there's no point, since it won't
3921 * be sending any more data anyway.
3926 if (newwin
> c
->v
.v2
.locwindow
) {
3927 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
3928 ssh2_pkt_adduint32(c
->remoteid
);
3929 ssh2_pkt_adduint32(newwin
- c
->v
.v2
.locwindow
);
3931 c
->v
.v2
.locwindow
= newwin
;
3936 * Handle the SSH2 userauth and connection layers.
3938 static void do_ssh2_authconn(unsigned char *in
, int inlen
, int ispkt
)
3941 AUTH_INVALID
, AUTH_PUBLICKEY_AGENT
, AUTH_PUBLICKEY_FILE
,
3943 AUTH_KEYBOARD_INTERACTIVE
3947 AUTH_TYPE_PUBLICKEY
,
3948 AUTH_TYPE_PUBLICKEY_OFFER_LOUD
,
3949 AUTH_TYPE_PUBLICKEY_OFFER_QUIET
,
3951 AUTH_TYPE_KEYBOARD_INTERACTIVE
,
3952 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
3954 static int gotit
, need_pw
, can_pubkey
, can_passwd
, can_keyb_inter
;
3955 static int tried_pubkey_config
, tried_agent
, tried_keyb_inter
;
3956 static int kbd_inter_running
;
3957 static int we_are_in
;
3958 static int num_prompts
, echo
;
3959 static char username
[100];
3960 static int got_username
;
3961 static char pwprompt
[200];
3962 static char password
[100];
3963 static void *publickey_blob
;
3964 static int publickey_bloblen
;
3969 * Request userauth protocol, and await a response to it.
3971 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
3972 ssh2_pkt_addstring("ssh-userauth");
3974 crWaitUntilV(ispkt
);
3975 if (pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
) {
3976 bombout(("Server refused user authentication protocol"));
3981 * We repeat this whole loop, including the username prompt,
3982 * until we manage a successful authentication. If the user
3983 * types the wrong _password_, they are sent back to the
3984 * beginning to try another username. (If they specify a
3985 * username in the config, they are never asked, even if they
3986 * do give a wrong password.)
3988 * I think this best serves the needs of
3990 * - the people who have no configuration, no keys, and just
3991 * want to try repeated (username,password) pairs until they
3992 * type both correctly
3994 * - people who have keys and configuration but occasionally
3995 * need to fall back to passwords
3997 * - people with a key held in Pageant, who might not have
3998 * logged in to a particular machine before; so they want to
3999 * type a username, and then _either_ their key will be
4000 * accepted, _or_ they will type a password. If they mistype
4001 * the username they will want to be able to get back and
4005 got_username
= FALSE
;
4014 if (got_username
&& !cfg
.change_username
) {
4016 * We got a username last time round this loop, and
4017 * with change_username turned off we don't try to get
4020 } else if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
4022 if (!ssh_get_line("login as: ",
4023 username
, sizeof(username
), FALSE
)) {
4025 * get_line failed to get a username.
4028 logevent("No username provided. Abandoning session.");
4029 ssh_state
= SSH_STATE_CLOSED
;
4033 c_write_str("login as: ");
4036 crWaitUntilV(!ispkt
);
4038 switch (c
= *in
++) {
4047 c_write_str("\b \b");
4054 c_write_str("\b \b");
4063 if (((c
>= ' ' && c
<= '~') ||
4064 ((unsigned char) c
>= 160))
4065 && pos
< sizeof(username
)-1) {
4066 username
[pos
++] = c
;
4073 c_write_str("\r\n");
4074 username
[strcspn(username
, "\n\r")] = '\0';
4077 strncpy(username
, cfg
.username
, 99);
4078 username
[99] = '\0';
4079 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
4080 sprintf(stuff
, "Using username \"%s\".\r\n", username
);
4084 got_username
= TRUE
;
4087 * Send an authentication request using method "none": (a)
4088 * just in case it succeeds, and (b) so that we know what
4089 * authentication methods we can usefully try next.
4091 ssh_pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4093 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4094 ssh2_pkt_addstring(username
);
4095 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4096 ssh2_pkt_addstring("none"); /* method */
4098 type
= AUTH_TYPE_NONE
;
4102 tried_pubkey_config
= FALSE
;
4103 tried_agent
= FALSE
;
4104 tried_keyb_inter
= FALSE
;
4105 kbd_inter_running
= FALSE
;
4106 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
4109 logeventf("Reading private key file \"%.150s\"", cfg
.keyfile
);
4110 keytype
= key_type(cfg
.keyfile
);
4111 if (keytype
== SSH_KEYTYPE_SSH2
)
4112 publickey_blob
= ssh2_userkey_loadpub(cfg
.keyfile
, NULL
,
4113 &publickey_bloblen
);
4116 logeventf("Unable to use this key file (%s)",
4117 key_type_to_str(keytype
));
4118 sprintf(msgbuf
, "Unable to use key file \"%.150s\" (%s)\r\n",
4119 cfg
.keyfile
, key_type_to_str(keytype
));
4120 c_write_str(msgbuf
);
4121 publickey_blob
= NULL
;
4124 publickey_blob
= NULL
;
4128 * Wait for the result of the last authentication request.
4131 crWaitUntilV(ispkt
);
4132 while (pktin
.type
== SSH2_MSG_USERAUTH_BANNER
) {
4136 * Don't show the banner if we're operating in
4137 * non-verbose non-interactive mode. (It's probably
4138 * a script, which means nobody will read the
4139 * banner _anyway_, and moreover the printing of
4140 * the banner will screw up processing on the
4141 * output of (say) plink.)
4143 if (flags
& (FLAG_VERBOSE
| FLAG_INTERACTIVE
)) {
4144 ssh2_pkt_getstring(&banner
, &size
);
4146 c_write_untrusted(banner
, size
);
4148 crWaitUntilV(ispkt
);
4150 if (pktin
.type
== SSH2_MSG_USERAUTH_SUCCESS
) {
4151 logevent("Access granted");
4156 if (kbd_inter_running
&&
4157 pktin
.type
== SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4159 * This is a further prompt in keyboard-interactive
4160 * authentication. Do nothing.
4162 } else if (pktin
.type
!= SSH2_MSG_USERAUTH_FAILURE
) {
4163 bombout(("Strange packet received during authentication: type %d",
4171 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4172 * we can look at the string in it and know what we can
4173 * helpfully try next.
4175 if (pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
) {
4178 ssh2_pkt_getstring(&methods
, &methlen
);
4179 kbd_inter_running
= FALSE
;
4180 if (!ssh2_pkt_getbool()) {
4182 * We have received an unequivocal Access
4183 * Denied. This can translate to a variety of
4186 * - if we'd just tried "none" authentication,
4187 * it's not worth printing anything at all
4189 * - if we'd just tried a public key _offer_,
4190 * the message should be "Server refused our
4191 * key" (or no message at all if the key
4192 * came from Pageant)
4194 * - if we'd just tried anything else, the
4195 * message really should be "Access denied".
4197 * Additionally, if we'd just tried password
4198 * authentication, we should break out of this
4199 * whole loop so as to go back to the username
4202 if (type
== AUTH_TYPE_NONE
) {
4204 } else if (type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
||
4205 type
== AUTH_TYPE_PUBLICKEY_OFFER_QUIET
) {
4206 if (type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
)
4207 c_write_str("Server refused our key\r\n");
4208 logevent("Server refused public key");
4209 } else if (type
== AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
) {
4210 /* server declined keyboard-interactive; ignore */
4212 c_write_str("Access denied\r\n");
4213 logevent("Access denied");
4214 if (type
== AUTH_TYPE_PASSWORD
) {
4220 c_write_str("Further authentication required\r\n");
4221 logevent("Further authentication required");
4225 in_commasep_string("publickey", methods
, methlen
);
4227 in_commasep_string("password", methods
, methlen
);
4228 can_keyb_inter
= cfg
.try_ki_auth
&&
4229 in_commasep_string("keyboard-interactive", methods
, methlen
);
4233 ssh_pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4235 if (!method
&& can_pubkey
&& agent_exists() && !tried_agent
) {
4237 * Attempt public-key authentication using Pageant.
4239 static unsigned char request
[5], *response
, *p
;
4240 static int responselen
;
4241 static int i
, nkeys
;
4242 static int authed
= FALSE
;
4245 ssh_pkt_ctx
|= SSH2_PKTCTX_PUBLICKEY
;
4249 logevent("Pageant is running. Requesting keys.");
4251 /* Request the keys held by the agent. */
4252 PUT_32BIT(request
, 1);
4253 request
[4] = SSH2_AGENTC_REQUEST_IDENTITIES
;
4254 agent_query(request
, 5, &r
, &responselen
);
4255 response
= (unsigned char *) r
;
4256 if (response
&& responselen
>= 5 &&
4257 response
[4] == SSH2_AGENT_IDENTITIES_ANSWER
) {
4259 nkeys
= GET_32BIT(p
);
4263 sprintf(buf
, "Pageant has %d SSH2 keys", nkeys
);
4266 for (i
= 0; i
< nkeys
; i
++) {
4267 static char *pkblob
, *alg
, *commentp
;
4268 static int pklen
, alglen
, commentlen
;
4269 static int siglen
, retlen
, len
;
4270 static char *q
, *agentreq
, *ret
;
4275 sprintf(buf
, "Trying Pageant key #%d", i
);
4278 pklen
= GET_32BIT(p
);
4280 if (publickey_blob
&&
4281 pklen
== publickey_bloblen
&&
4282 !memcmp(p
, publickey_blob
, publickey_bloblen
)) {
4283 logevent("This key matches configured key file");
4284 tried_pubkey_config
= 1;
4288 alglen
= GET_32BIT(pkblob
);
4290 commentlen
= GET_32BIT(p
);
4294 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4295 ssh2_pkt_addstring(username
);
4296 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4297 ssh2_pkt_addstring("publickey"); /* method */
4298 ssh2_pkt_addbool(FALSE
); /* no signature included */
4299 ssh2_pkt_addstring_start();
4300 ssh2_pkt_addstring_data(alg
, alglen
);
4301 ssh2_pkt_addstring_start();
4302 ssh2_pkt_addstring_data(pkblob
, pklen
);
4305 crWaitUntilV(ispkt
);
4306 if (pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4307 logevent("Key refused");
4311 if (flags
& FLAG_VERBOSE
) {
4313 ("Authenticating with public key \"");
4314 c_write(commentp
, commentlen
);
4315 c_write_str("\" from agent\r\n");
4319 * Server is willing to accept the key.
4320 * Construct a SIGN_REQUEST.
4322 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4323 ssh2_pkt_addstring(username
);
4324 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4325 ssh2_pkt_addstring("publickey"); /* method */
4326 ssh2_pkt_addbool(TRUE
);
4327 ssh2_pkt_addstring_start();
4328 ssh2_pkt_addstring_data(alg
, alglen
);
4329 ssh2_pkt_addstring_start();
4330 ssh2_pkt_addstring_data(pkblob
, pklen
);
4332 siglen
= pktout
.length
- 5 + 4 + 20;
4333 len
= 1; /* message type */
4334 len
+= 4 + pklen
; /* key blob */
4335 len
+= 4 + siglen
; /* data to sign */
4336 len
+= 4; /* flags */
4337 agentreq
= smalloc(4 + len
);
4338 PUT_32BIT(agentreq
, len
);
4340 *q
++ = SSH2_AGENTC_SIGN_REQUEST
;
4341 PUT_32BIT(q
, pklen
);
4343 memcpy(q
, pkblob
, pklen
);
4345 PUT_32BIT(q
, siglen
);
4347 /* Now the data to be signed... */
4350 memcpy(q
, ssh2_session_id
, 20);
4352 memcpy(q
, pktout
.data
+ 5, pktout
.length
- 5);
4353 q
+= pktout
.length
- 5;
4354 /* And finally the (zero) flags word. */
4356 agent_query(agentreq
, len
+ 4, &vret
, &retlen
);
4360 if (ret
[4] == SSH2_AGENT_SIGN_RESPONSE
) {
4361 logevent("Sending Pageant's response");
4362 ssh2_pkt_addstring_start();
4363 ssh2_pkt_addstring_data(ret
+ 9,
4371 ("Pageant failed to answer challenge");
4381 if (!method
&& can_pubkey
&& publickey_blob
4382 && !tried_pubkey_config
) {
4383 unsigned char *pub_blob
;
4384 char *algorithm
, *comment
;
4387 tried_pubkey_config
= TRUE
;
4389 ssh_pkt_ctx
|= SSH2_PKTCTX_PUBLICKEY
;
4392 * Try the public key supplied in the configuration.
4394 * First, offer the public blob to see if the server is
4395 * willing to accept it.
4397 pub_blob
= ssh2_userkey_loadpub(cfg
.keyfile
, &algorithm
,
4400 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4401 ssh2_pkt_addstring(username
);
4402 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4403 ssh2_pkt_addstring("publickey"); /* method */
4404 ssh2_pkt_addbool(FALSE
); /* no signature included */
4405 ssh2_pkt_addstring(algorithm
);
4406 ssh2_pkt_addstring_start();
4407 ssh2_pkt_addstring_data(pub_blob
, pub_blob_len
);
4409 logevent("Offered public key"); /* FIXME */
4411 crWaitUntilV(ispkt
);
4412 if (pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4414 type
= AUTH_TYPE_PUBLICKEY_OFFER_LOUD
;
4415 continue; /* key refused; give up on it */
4418 logevent("Offer of public key accepted");
4420 * Actually attempt a serious authentication using
4423 if (ssh2_userkey_encrypted(cfg
.keyfile
, &comment
)) {
4425 "Passphrase for key \"%.100s\": ",
4431 c_write_str("Authenticating with public key \"");
4432 c_write_str(comment
);
4433 c_write_str("\"\r\n");
4434 method
= AUTH_PUBLICKEY_FILE
;
4438 if (!method
&& can_keyb_inter
&& !tried_keyb_inter
) {
4439 method
= AUTH_KEYBOARD_INTERACTIVE
;
4440 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4441 tried_keyb_inter
= TRUE
;
4443 ssh_pkt_ctx
|= SSH2_PKTCTX_KBDINTER
;
4445 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4446 ssh2_pkt_addstring(username
);
4447 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4448 ssh2_pkt_addstring("keyboard-interactive"); /* method */
4449 ssh2_pkt_addstring(""); /* lang */
4450 ssh2_pkt_addstring("");
4453 crWaitUntilV(ispkt
);
4454 if (pktin
.type
!= SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4455 if (pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
)
4457 logevent("Keyboard-interactive authentication refused");
4458 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
;
4462 kbd_inter_running
= TRUE
;
4465 if (kbd_inter_running
) {
4466 method
= AUTH_KEYBOARD_INTERACTIVE
;
4467 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4468 tried_keyb_inter
= TRUE
;
4470 ssh_pkt_ctx
|= SSH2_PKTCTX_KBDINTER
;
4472 /* We've got packet with that "interactive" info
4473 dump banners, and set its prompt as ours */
4475 char *name
, *inst
, *lang
, *prompt
;
4476 int name_len
, inst_len
, lang_len
, prompt_len
;
4477 ssh2_pkt_getstring(&name
, &name_len
);
4478 ssh2_pkt_getstring(&inst
, &inst_len
);
4479 ssh2_pkt_getstring(&lang
, &lang_len
);
4481 c_write_untrusted(name
, name_len
);
4483 c_write_untrusted(inst
, inst_len
);
4484 num_prompts
= ssh2_pkt_getuint32();
4486 ssh2_pkt_getstring(&prompt
, &prompt_len
);
4487 strncpy(pwprompt
, prompt
, sizeof(pwprompt
));
4488 pwprompt
[prompt_len
< sizeof(pwprompt
) ?
4489 prompt_len
: sizeof(pwprompt
)-1] = '\0';
4492 echo
= ssh2_pkt_getbool();
4496 if (!method
&& can_passwd
) {
4497 method
= AUTH_PASSWORD
;
4498 ssh_pkt_ctx
|= SSH2_PKTCTX_PASSWORD
;
4499 sprintf(pwprompt
, "%.90s@%.90s's password: ", username
,
4506 if (!ssh_get_line(pwprompt
, password
,
4507 sizeof(password
), TRUE
)) {
4509 * get_line failed to get a password (for
4510 * example because one was supplied on the
4511 * command line which has already failed to
4514 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
4515 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
4517 ("No more passwords available to try");
4518 ssh2_pkt_addstring("en"); /* language tag */
4520 logevent("Unable to authenticate");
4521 connection_fatal("Unable to authenticate");
4522 ssh_state
= SSH_STATE_CLOSED
;
4529 c_write_untrusted(pwprompt
, strlen(pwprompt
));
4534 crWaitUntilV(!ispkt
);
4536 switch (c
= *in
++) {
4556 if (pos
< sizeof(password
)-1)
4557 password
[pos
++] = c
;
4561 c_write_str("\r\n");
4565 if (method
== AUTH_PUBLICKEY_FILE
) {
4567 * We have our passphrase. Now try the actual authentication.
4569 struct ssh2_userkey
*key
;
4571 key
= ssh2_load_userkey(cfg
.keyfile
, password
);
4572 if (key
== SSH2_WRONG_PASSPHRASE
|| key
== NULL
) {
4573 if (key
== SSH2_WRONG_PASSPHRASE
) {
4574 c_write_str("Wrong passphrase\r\n");
4575 tried_pubkey_config
= FALSE
;
4577 c_write_str("Unable to load private key\r\n");
4578 tried_pubkey_config
= TRUE
;
4580 /* Send a spurious AUTH_NONE to return to the top. */
4581 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4582 ssh2_pkt_addstring(username
);
4583 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4584 ssh2_pkt_addstring("none"); /* method */
4586 type
= AUTH_TYPE_NONE
;
4588 unsigned char *blob
, *sigdata
;
4589 int blob_len
, sigdata_len
;
4592 * We have loaded the private key and the server
4593 * has announced that it's willing to accept it.
4594 * Hallelujah. Generate a signature and send it.
4596 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4597 ssh2_pkt_addstring(username
);
4598 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4599 ssh2_pkt_addstring("publickey"); /* method */
4600 ssh2_pkt_addbool(TRUE
);
4601 ssh2_pkt_addstring(key
->alg
->name
);
4602 blob
= key
->alg
->public_blob(key
->data
, &blob_len
);
4603 ssh2_pkt_addstring_start();
4604 ssh2_pkt_addstring_data(blob
, blob_len
);
4608 * The data to be signed is:
4612 * followed by everything so far placed in the
4615 sigdata_len
= pktout
.length
- 5 + 4 + 20;
4616 sigdata
= smalloc(sigdata_len
);
4617 PUT_32BIT(sigdata
, 20);
4618 memcpy(sigdata
+ 4, ssh2_session_id
, 20);
4619 memcpy(sigdata
+ 24, pktout
.data
+ 5,
4622 key
->alg
->sign(key
->data
, sigdata
, sigdata_len
,
4624 ssh2_pkt_addstring_start();
4625 ssh2_pkt_addstring_data(blob
, blob_len
);
4630 type
= AUTH_TYPE_PUBLICKEY
;
4632 } else if (method
== AUTH_PASSWORD
) {
4634 * We send the password packet lumped tightly together with
4635 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4636 * string long enough to make the total length of the two
4637 * packets constant. This should ensure that a passive
4638 * listener doing traffic analyis can't work out the length
4641 * For this to work, we need an assumption about the
4642 * maximum length of the password packet. I think 256 is
4643 * pretty conservative. Anyone using a password longer than
4644 * that probably doesn't have much to worry about from
4645 * people who find out how long their password is!
4647 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4648 ssh2_pkt_addstring(username
);
4649 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4650 ssh2_pkt_addstring("password");
4651 ssh2_pkt_addbool(FALSE
);
4652 ssh2_pkt_addstring(password
);
4655 * We'll include a string that's an exact multiple of the
4656 * cipher block size. If the cipher is NULL for some
4657 * reason, we don't do this trick at all because we gain
4663 stringlen
= (256 - deferred_len
);
4664 stringlen
+= cscipher
->blksize
- 1;
4665 stringlen
-= (stringlen
% cscipher
->blksize
);
4668 * Temporarily disable actual compression,
4669 * so we can guarantee to get this string
4670 * exactly the length we want it. The
4671 * compression-disabling routine should
4672 * return an integer indicating how many
4673 * bytes we should adjust our string length
4676 stringlen
-= cscomp
->disable_compression();
4678 ssh2_pkt_init(SSH2_MSG_IGNORE
);
4679 ssh2_pkt_addstring_start();
4680 for (i
= 0; i
< stringlen
; i
++) {
4681 char c
= (char) random_byte();
4682 ssh2_pkt_addstring_data(&c
, 1);
4686 ssh_pkt_defersend();
4687 logevent("Sent password");
4688 type
= AUTH_TYPE_PASSWORD
;
4689 } else if (method
== AUTH_KEYBOARD_INTERACTIVE
) {
4690 ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE
);
4691 ssh2_pkt_adduint32(num_prompts
);
4692 ssh2_pkt_addstring(password
);
4693 memset(password
, 0, sizeof(password
));
4695 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4698 ("No supported authentication methods left to try!\r\n");
4700 ("No supported authentications offered. Disconnecting");
4701 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
4702 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
4704 ("No supported authentication methods available");
4705 ssh2_pkt_addstring("en"); /* language tag */
4707 ssh_state
= SSH_STATE_CLOSED
;
4711 } while (!we_are_in
);
4714 * Now we're authenticated for the connection protocol. The
4715 * connection protocol will automatically have started at this
4716 * point; there's no need to send SERVICE_REQUEST.
4720 * So now create a channel with a session in it.
4722 ssh_channels
= newtree234(ssh_channelcmp
);
4723 mainchan
= smalloc(sizeof(struct ssh_channel
));
4724 mainchan
->localid
= alloc_channel_id();
4725 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
4726 ssh2_pkt_addstring("session");
4727 ssh2_pkt_adduint32(mainchan
->localid
);
4728 mainchan
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
4729 ssh2_pkt_adduint32(mainchan
->v
.v2
.locwindow
); /* our window size */
4730 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
4732 crWaitUntilV(ispkt
);
4733 if (pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
4734 bombout(("Server refused to open a session"));
4736 /* FIXME: error data comes back in FAILURE packet */
4738 if (ssh2_pkt_getuint32() != mainchan
->localid
) {
4739 bombout(("Server's channel confirmation cited wrong channel"));
4742 mainchan
->remoteid
= ssh2_pkt_getuint32();
4743 mainchan
->type
= CHAN_MAINSESSION
;
4744 mainchan
->closes
= 0;
4745 mainchan
->v
.v2
.remwindow
= ssh2_pkt_getuint32();
4746 mainchan
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32();
4747 bufchain_init(&mainchan
->v
.v2
.outbuffer
);
4748 add234(ssh_channels
, mainchan
);
4749 logevent("Opened channel for session");
4752 * Potentially enable X11 forwarding.
4754 if (cfg
.x11_forward
) {
4755 char proto
[20], data
[64];
4756 logevent("Requesting X11 forwarding");
4757 x11_invent_auth(proto
, sizeof(proto
), data
, sizeof(data
));
4758 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4759 ssh2_pkt_adduint32(mainchan
->remoteid
);
4760 ssh2_pkt_addstring("x11-req");
4761 ssh2_pkt_addbool(1); /* want reply */
4762 ssh2_pkt_addbool(0); /* many connections */
4763 ssh2_pkt_addstring(proto
);
4764 ssh2_pkt_addstring(data
);
4765 ssh2_pkt_adduint32(0); /* screen number */
4769 crWaitUntilV(ispkt
);
4770 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4771 unsigned i
= ssh2_pkt_getuint32();
4772 struct ssh_channel
*c
;
4773 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4775 continue; /* nonexistent channel */
4776 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4778 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4780 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4781 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4782 bombout(("Unexpected response to X11 forwarding request:"
4783 " packet type %d", pktin
.type
));
4786 logevent("X11 forwarding refused");
4788 logevent("X11 forwarding enabled");
4789 ssh_X11_fwd_enabled
= TRUE
;
4794 * Enable port forwardings.
4797 static char *e
; /* preserve across crReturn */
4800 int sport
,dport
,sserv
,dserv
;
4801 char sports
[256], dports
[256], host
[256];
4805 ssh_rportfwds
= newtree234(ssh_rportcmp_ssh2
);
4806 /* Add port forwardings. */
4811 while (*e
&& *e
!= '\t')
4817 while (*e
&& *e
!= ':')
4827 dport
= atoi(dports
);
4831 se
= getservbyname(dports
, NULL
);
4833 dport
= ntohs(se
->s_port
);
4836 "Service lookup failed for destination port \"%s\"",
4841 sport
= atoi(sports
);
4845 se
= getservbyname(sports
, NULL
);
4847 sport
= ntohs(se
->s_port
);
4850 "Service lookup failed for source port \"%s\"",
4855 if (sport
&& dport
) {
4857 pfd_addforward(host
, dport
, sport
);
4858 sprintf(buf
, "Local port %.*s%.*s%d%.*s forwarding to"
4859 " %s:%.*s%.*s%d%.*s",
4860 sserv ?
strlen(sports
) : 0, sports
,
4861 sserv
, "(", sport
, sserv
, ")",
4863 dserv ?
strlen(dports
) : 0, dports
,
4864 dserv
, "(", dport
, dserv
, ")");
4867 struct ssh_rportfwd
*pf
;
4868 pf
= smalloc(sizeof(*pf
));
4869 strcpy(pf
->dhost
, host
);
4872 if (add234(ssh_rportfwds
, pf
) != pf
) {
4874 "Duplicate remote port forwarding to %s:%d",
4879 sprintf(buf
, "Requesting remote port %.*s%.*s%d%.*s"
4880 " forward to %s:%.*s%.*s%d%.*s",
4881 sserv ?
strlen(sports
) : 0, sports
,
4882 sserv
, "(", sport
, sserv
, ")",
4884 dserv ?
strlen(dports
) : 0, dports
,
4885 dserv
, "(", dport
, dserv
, ")");
4887 ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST
);
4888 ssh2_pkt_addstring("tcpip-forward");
4889 ssh2_pkt_addbool(1);/* want reply */
4890 if (cfg
.rport_acceptall
)
4891 ssh2_pkt_addstring("0.0.0.0");
4893 ssh2_pkt_addstring("127.0.0.1");
4894 ssh2_pkt_adduint32(sport
);
4898 crWaitUntilV(ispkt
);
4899 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4900 unsigned i
= ssh2_pkt_getuint32();
4901 struct ssh_channel
*c
;
4902 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4904 continue;/* nonexistent channel */
4905 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4907 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4909 if (pktin
.type
!= SSH2_MSG_REQUEST_SUCCESS
) {
4910 if (pktin
.type
!= SSH2_MSG_REQUEST_FAILURE
) {
4911 bombout(("Unexpected response to port "
4912 "forwarding request: packet type %d",
4916 logevent("Server refused this port forwarding");
4918 logevent("Remote port forwarding enabled");
4927 * Potentially enable agent forwarding.
4929 if (cfg
.agentfwd
&& agent_exists()) {
4930 logevent("Requesting OpenSSH-style agent forwarding");
4931 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4932 ssh2_pkt_adduint32(mainchan
->remoteid
);
4933 ssh2_pkt_addstring("auth-agent-req@openssh.com");
4934 ssh2_pkt_addbool(1); /* want reply */
4938 crWaitUntilV(ispkt
);
4939 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4940 unsigned i
= ssh2_pkt_getuint32();
4941 struct ssh_channel
*c
;
4942 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4944 continue; /* nonexistent channel */
4945 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4947 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4949 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4950 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4951 bombout(("Unexpected response to agent forwarding request:"
4952 " packet type %d", pktin
.type
));
4955 logevent("Agent forwarding refused");
4957 logevent("Agent forwarding enabled");
4958 ssh_agentfwd_enabled
= TRUE
;
4963 * Now allocate a pty for the session.
4966 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4967 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
4968 ssh2_pkt_addstring("pty-req");
4969 ssh2_pkt_addbool(1); /* want reply */
4970 ssh2_pkt_addstring(cfg
.termtype
);
4971 ssh2_pkt_adduint32(cols
);
4972 ssh2_pkt_adduint32(rows
);
4973 ssh2_pkt_adduint32(0); /* pixel width */
4974 ssh2_pkt_adduint32(0); /* pixel height */
4975 ssh2_pkt_addstring_start();
4976 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
4978 ssh_state
= SSH_STATE_INTERMED
;
4981 crWaitUntilV(ispkt
);
4982 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4983 unsigned i
= ssh2_pkt_getuint32();
4984 struct ssh_channel
*c
;
4985 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4987 continue; /* nonexistent channel */
4988 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4990 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4992 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4993 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4994 bombout(("Unexpected response to pty request:"
4995 " packet type %d", pktin
.type
));
4998 c_write_str("Server refused to allocate pty\r\n");
4999 ssh_editing
= ssh_echoing
= 1;
5001 logevent("Allocated pty");
5004 ssh_editing
= ssh_echoing
= 1;
5008 * Start a shell or a remote command. We may have to attempt
5009 * this twice if the config data has provided a second choice
5016 if (ssh_fallback_cmd
) {
5017 subsys
= cfg
.ssh_subsys2
;
5018 cmd
= cfg
.remote_cmd_ptr2
;
5020 subsys
= cfg
.ssh_subsys
;
5021 cmd
= cfg
.remote_cmd_ptr
;
5024 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
5025 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
5027 ssh2_pkt_addstring("subsystem");
5028 ssh2_pkt_addbool(1); /* want reply */
5029 ssh2_pkt_addstring(cmd
);
5031 ssh2_pkt_addstring("exec");
5032 ssh2_pkt_addbool(1); /* want reply */
5033 ssh2_pkt_addstring(cmd
);
5035 ssh2_pkt_addstring("shell");
5036 ssh2_pkt_addbool(1); /* want reply */
5040 crWaitUntilV(ispkt
);
5041 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5042 unsigned i
= ssh2_pkt_getuint32();
5043 struct ssh_channel
*c
;
5044 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5046 continue; /* nonexistent channel */
5047 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
5049 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5050 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5051 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5052 bombout(("Unexpected response to shell/command request:"
5053 " packet type %d", pktin
.type
));
5057 * We failed to start the command. If this is the
5058 * fallback command, we really are finished; if it's
5059 * not, and if the fallback command exists, try falling
5060 * back to it before complaining.
5062 if (!ssh_fallback_cmd
&& cfg
.remote_cmd_ptr2
!= NULL
) {
5063 logevent("Primary command failed; attempting fallback");
5064 ssh_fallback_cmd
= TRUE
;
5067 bombout(("Server refused to start a shell/command"));
5070 logevent("Started a shell/command");
5075 ssh_state
= SSH_STATE_SESSION
;
5079 ssh_special(TS_EOF
);
5084 ldisc_send(NULL
, 0, 0); /* cause ldisc to notice changes */
5087 static int try_send
;
5091 if (pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
5092 pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
5095 unsigned i
= ssh2_pkt_getuint32();
5096 struct ssh_channel
*c
;
5097 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5099 continue; /* nonexistent channel */
5100 if (pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
5101 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR
)
5102 continue; /* extended but not stderr */
5103 ssh2_pkt_getstring(&data
, &length
);
5106 c
->v
.v2
.locwindow
-= length
;
5108 case CHAN_MAINSESSION
:
5110 from_backend(pktin
.type
==
5111 SSH2_MSG_CHANNEL_EXTENDED_DATA
,
5115 bufsize
= x11_send(c
->u
.x11
.s
, data
, length
);
5118 bufsize
= pfd_send(c
->u
.pfd
.s
, data
, length
);
5121 while (length
> 0) {
5122 if (c
->u
.a
.lensofar
< 4) {
5123 int l
= min(4 - c
->u
.a
.lensofar
, length
);
5124 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
,
5128 c
->u
.a
.lensofar
+= l
;
5130 if (c
->u
.a
.lensofar
== 4) {
5132 4 + GET_32BIT(c
->u
.a
.msglen
);
5133 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
5134 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
5136 if (c
->u
.a
.lensofar
>= 4 && length
> 0) {
5138 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
5140 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
,
5144 c
->u
.a
.lensofar
+= l
;
5146 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
5147 void *reply
, *sentreply
;
5149 agent_query(c
->u
.a
.message
,
5150 c
->u
.a
.totallen
, &reply
,
5155 /* Fake SSH_AGENT_FAILURE. */
5156 sentreply
= "\0\0\0\1\5";
5159 ssh2_add_channel_data(c
, sentreply
,
5164 sfree(c
->u
.a
.message
);
5165 c
->u
.a
.lensofar
= 0;
5172 * If we are not buffering too much data,
5173 * enlarge the window again at the remote side.
5175 if (bufsize
< OUR_V2_WINSIZE
)
5176 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
5178 } else if (pktin
.type
== SSH2_MSG_DISCONNECT
) {
5179 ssh_state
= SSH_STATE_CLOSED
;
5180 logevent("Received disconnect message");
5182 } else if (pktin
.type
== SSH2_MSG_CHANNEL_EOF
) {
5183 unsigned i
= ssh2_pkt_getuint32();
5184 struct ssh_channel
*c
;
5186 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5188 continue; /* nonexistent channel */
5190 if (c
->type
== CHAN_X11
) {
5192 * Remote EOF on an X11 channel means we should
5193 * wrap up and close the channel ourselves.
5195 x11_close(c
->u
.x11
.s
);
5197 } else if (c
->type
== CHAN_AGENT
) {
5199 } else if (c
->type
== CHAN_SOCKDATA
) {
5200 pfd_close(c
->u
.pfd
.s
);
5203 } else if (pktin
.type
== SSH2_MSG_CHANNEL_CLOSE
) {
5204 unsigned i
= ssh2_pkt_getuint32();
5205 struct ssh_channel
*c
;
5207 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5209 continue; /* nonexistent channel */
5210 /* Do pre-close processing on the channel. */
5212 case CHAN_MAINSESSION
:
5213 break; /* nothing to see here, move along */
5215 if (c
->u
.x11
.s
!= NULL
)
5216 x11_close(c
->u
.x11
.s
);
5223 if (c
->u
.pfd
.s
!= NULL
)
5224 pfd_close(c
->u
.pfd
.s
);
5228 if (c
->closes
== 0) {
5229 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
5230 ssh2_pkt_adduint32(c
->remoteid
);
5233 del234(ssh_channels
, c
);
5234 bufchain_clear(&c
->v
.v2
.outbuffer
);
5238 * See if that was the last channel left open.
5240 if (count234(ssh_channels
) == 0) {
5243 * We used to send SSH_MSG_DISCONNECT here,
5244 * because I'd believed that _every_ conforming
5245 * SSH2 connection had to end with a disconnect
5246 * being sent by at least one side; apparently
5247 * I was wrong and it's perfectly OK to
5248 * unceremoniously slam the connection shut
5249 * when you're done, and indeed OpenSSH feels
5250 * this is more polite than sending a
5251 * DISCONNECT. So now we don't.
5253 logevent("All channels closed. Disconnecting");
5254 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
5255 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
5256 ssh2_pkt_addstring("All open channels closed");
5257 ssh2_pkt_addstring("en"); /* language tag */
5260 ssh_state
= SSH_STATE_CLOSED
;
5263 continue; /* remote sends close; ignore (FIXME) */
5264 } else if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5265 unsigned i
= ssh2_pkt_getuint32();
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();
5272 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
5273 unsigned i
= ssh2_pkt_getuint32();
5274 struct ssh_channel
*c
;
5275 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5277 continue; /* nonexistent channel */
5278 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
5279 continue; /* dunno why they're confirming this */
5280 c
->remoteid
= ssh2_pkt_getuint32();
5281 c
->type
= CHAN_SOCKDATA
;
5282 c
->v
.v2
.remwindow
= ssh2_pkt_getuint32();
5283 c
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32();
5284 bufchain_init(&c
->v
.v2
.outbuffer
);
5286 pfd_confirm(c
->u
.pfd
.s
);
5289 * We have a pending close on this channel,
5290 * which we decided on before the server acked
5291 * the channel open. So now we know the
5292 * remoteid, we can close it again.
5294 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
5295 ssh2_pkt_adduint32(c
->remoteid
);
5298 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN_FAILURE
) {
5299 unsigned i
= ssh2_pkt_getuint32();
5300 struct ssh_channel
*c
;
5301 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5303 continue; /* nonexistent channel */
5304 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
5305 continue; /* dunno why they're failing this */
5307 logevent("Forwarded connection refused by server");
5309 pfd_close(c
->u
.pfd
.s
);
5311 del234(ssh_channels
, c
);
5313 } else if (pktin
.type
== SSH2_MSG_CHANNEL_REQUEST
) {
5316 int typelen
, want_reply
;
5317 struct ssh_channel
*c
;
5319 localid
= ssh2_pkt_getuint32();
5320 ssh2_pkt_getstring(&type
, &typelen
);
5321 want_reply
= ssh2_pkt_getbool();
5324 * First, check that the channel exists. Otherwise,
5325 * we can instantly disconnect with a rude message.
5327 c
= find234(ssh_channels
, &localid
, ssh_channelfind
);
5330 sprintf(buf
, "Received channel request for nonexistent"
5331 " channel %d", localid
);
5333 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
5334 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
5335 ssh2_pkt_addstring(buf
);
5336 ssh2_pkt_addstring("en"); /* language tag */
5338 connection_fatal("%s", buf
);
5339 ssh_state
= SSH_STATE_CLOSED
;
5344 * Having got the channel number, we now look at
5345 * the request type string to see if it's something
5348 if (typelen
== 11 && !memcmp(type
, "exit-status", 11) &&
5350 /* We recognise "exit-status" on the primary channel. */
5352 ssh_exitcode
= ssh2_pkt_getuint32();
5353 sprintf(buf
, "Server sent command exit status %d",
5357 ssh2_pkt_init(SSH2_MSG_CHANNEL_SUCCESS
);
5358 ssh2_pkt_adduint32(c
->remoteid
);
5363 * This is a channel request we don't know
5364 * about, so we now either ignore the request
5365 * or respond with CHANNEL_FAILURE, depending
5369 ssh2_pkt_init(SSH2_MSG_CHANNEL_FAILURE
);
5370 ssh2_pkt_adduint32(c
->remoteid
);
5374 } else if (pktin
.type
== SSH2_MSG_GLOBAL_REQUEST
) {
5376 int typelen
, want_reply
;
5378 ssh2_pkt_getstring(&type
, &typelen
);
5379 want_reply
= ssh2_pkt_getbool();
5382 * We currently don't support any global requests
5383 * at all, so we either ignore the request or
5384 * respond with REQUEST_FAILURE, depending on
5388 ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE
);
5391 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN
) {
5395 struct ssh_channel
*c
;
5396 unsigned remid
, winsize
, pktsize
;
5397 ssh2_pkt_getstring(&type
, &typelen
);
5398 c
= smalloc(sizeof(struct ssh_channel
));
5400 remid
= ssh2_pkt_getuint32();
5401 winsize
= ssh2_pkt_getuint32();
5402 pktsize
= ssh2_pkt_getuint32();
5404 if (typelen
== 3 && !memcmp(type
, "x11", 3)) {
5405 if (!ssh_X11_fwd_enabled
)
5406 error
= "X11 forwarding is not enabled";
5407 else if (x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
) !=
5409 error
= "Unable to open an X11 connection";
5413 } else if (typelen
== 15 &&
5414 !memcmp(type
, "forwarded-tcpip", 15)) {
5415 struct ssh_rportfwd pf
, *realpf
;
5418 ssh2_pkt_getstring(&dummy
, &dummylen
);/* skip address */
5419 pf
.sport
= ssh2_pkt_getuint32();
5420 realpf
= find234(ssh_rportfwds
, &pf
, NULL
);
5421 if (realpf
== NULL
) {
5422 error
= "Remote port is not recognised";
5424 char *e
= pfd_newconnect(&c
->u
.pfd
.s
, realpf
->dhost
,
5427 sprintf(buf
, "Received remote port open request for %s:%d",
5428 realpf
->dhost
, realpf
->dport
);
5431 sprintf(buf
, "Port open failed: %s", e
);
5433 error
= "Port open failed";
5435 logevent("Forwarded port opened successfully");
5436 c
->type
= CHAN_SOCKDATA
;
5439 } else if (typelen
== 22 &&
5440 !memcmp(type
, "auth-agent@openssh.com", 3)) {
5441 if (!ssh_agentfwd_enabled
)
5442 error
= "Agent forwarding is not enabled";
5444 c
->type
= CHAN_AGENT
; /* identify channel type */
5445 c
->u
.a
.lensofar
= 0;
5448 error
= "Unsupported channel type requested";
5451 c
->remoteid
= remid
;
5453 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE
);
5454 ssh2_pkt_adduint32(c
->remoteid
);
5455 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED
);
5456 ssh2_pkt_addstring(error
);
5457 ssh2_pkt_addstring("en"); /* language tag */
5461 c
->localid
= alloc_channel_id();
5463 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5464 c
->v
.v2
.remwindow
= winsize
;
5465 c
->v
.v2
.remmaxpkt
= pktsize
;
5466 bufchain_init(&c
->v
.v2
.outbuffer
);
5467 add234(ssh_channels
, c
);
5468 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
5469 ssh2_pkt_adduint32(c
->remoteid
);
5470 ssh2_pkt_adduint32(c
->localid
);
5471 ssh2_pkt_adduint32(c
->v
.v2
.locwindow
);
5472 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
5476 bombout(("Strange packet received: type %d", pktin
.type
));
5481 * We have spare data. Add it to the channel buffer.
5483 ssh2_add_channel_data(mainchan
, in
, inlen
);
5488 struct ssh_channel
*c
;
5490 * Try to send data on all channels if we can.
5492 for (i
= 0; NULL
!= (c
= index234(ssh_channels
, i
)); i
++) {
5493 int bufsize
= ssh2_try_send(c
);
5496 case CHAN_MAINSESSION
:
5497 /* stdin need not receive an unthrottle
5498 * notification since it will be polled */
5501 x11_unthrottle(c
->u
.x11
.s
);
5504 /* agent sockets are request/response and need no
5505 * buffer management */
5508 pfd_unthrottle(c
->u
.pfd
.s
);
5520 * Handle the top-level SSH2 protocol.
5522 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
)
5524 if (do_ssh2_transport(in
, inlen
, ispkt
) == 0)
5526 do_ssh2_authconn(in
, inlen
, ispkt
);
5530 * Called to set up the connection.
5532 * Returns an error message, or NULL on success.
5534 static char *ssh_init(char *host
, int port
, char **realhost
, int nodelay
)
5539 if (crypto_startup() == 0)
5540 return "Microsoft high encryption pack not installed!";
5546 ssh1_throttle_count
= 0;
5547 ssh_overall_bufsize
= 0;
5548 ssh_fallback_cmd
= 0;
5550 p
= connect_to_host(host
, port
, realhost
, nodelay
);
5558 * Called to send data down the Telnet connection.
5560 static int ssh_send(char *buf
, int len
)
5562 if (s
== NULL
|| ssh_protocol
== NULL
)
5565 ssh_protocol(buf
, len
, 0);
5567 return ssh_sendbuffer();
5571 * Called to query the current amount of buffered stdin data.
5573 static int ssh_sendbuffer(void)
5577 if (s
== NULL
|| ssh_protocol
== NULL
)
5581 * If the SSH socket itself has backed up, add the total backup
5582 * size on that to any individual buffer on the stdin channel.
5585 if (ssh_throttled_all
)
5586 override_value
= ssh_overall_bufsize
;
5588 if (ssh_version
== 1) {
5589 return override_value
;
5590 } else if (ssh_version
== 2) {
5591 if (!mainchan
|| mainchan
->closes
> 0)
5592 return override_value
;
5594 return override_value
+ bufchain_size(&mainchan
->v
.v2
.outbuffer
);
5601 * Called to set the size of the window from SSH's POV.
5603 static void ssh_size(void)
5605 switch (ssh_state
) {
5606 case SSH_STATE_BEFORE_SIZE
:
5607 case SSH_STATE_PREPACKET
:
5608 case SSH_STATE_CLOSED
:
5609 break; /* do nothing */
5610 case SSH_STATE_INTERMED
:
5611 size_needed
= TRUE
; /* buffer for later */
5613 case SSH_STATE_SESSION
:
5615 if (ssh_version
== 1) {
5616 send_packet(SSH1_CMSG_WINDOW_SIZE
,
5617 PKT_INT
, rows
, PKT_INT
, cols
,
5618 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
5620 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
5621 ssh2_pkt_adduint32(mainchan
->remoteid
);
5622 ssh2_pkt_addstring("window-change");
5623 ssh2_pkt_addbool(0);
5624 ssh2_pkt_adduint32(cols
);
5625 ssh2_pkt_adduint32(rows
);
5626 ssh2_pkt_adduint32(0);
5627 ssh2_pkt_adduint32(0);
5636 * Send Telnet special codes. TS_EOF is useful for `plink', so you
5637 * can send an EOF and collect resulting output (e.g. `plink
5640 static void ssh_special(Telnet_Special code
)
5642 if (code
== TS_EOF
) {
5643 if (ssh_state
!= SSH_STATE_SESSION
) {
5645 * Buffer the EOF in case we are pre-SESSION, so we can
5646 * send it as soon as we reach SESSION.
5652 if (ssh_version
== 1) {
5653 send_packet(SSH1_CMSG_EOF
, PKT_END
);
5655 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF
);
5656 ssh2_pkt_adduint32(mainchan
->remoteid
);
5659 logevent("Sent EOF message");
5660 } else if (code
== TS_PING
) {
5661 if (ssh_state
== SSH_STATE_CLOSED
5662 || ssh_state
== SSH_STATE_PREPACKET
) return;
5663 if (ssh_version
== 1) {
5664 send_packet(SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
5666 ssh2_pkt_init(SSH2_MSG_IGNORE
);
5667 ssh2_pkt_addstring_start();
5675 void *new_sock_channel(Socket s
)
5677 struct ssh_channel
*c
;
5678 c
= smalloc(sizeof(struct ssh_channel
));
5681 c
->remoteid
= -1; /* to be set when open confirmed */
5682 c
->localid
= alloc_channel_id();
5684 c
->type
= CHAN_SOCKDATA_DORMANT
;/* identify channel type */
5686 add234(ssh_channels
, c
);
5692 * This is called when stdout/stderr (the entity to which
5693 * from_backend sends data) manages to clear some backlog.
5695 void ssh_unthrottle(int bufsize
)
5697 if (ssh_version
== 1) {
5698 if (ssh1_stdout_throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
5699 ssh1_stdout_throttling
= 0;
5703 if (mainchan
&& mainchan
->closes
== 0)
5704 ssh2_set_window(mainchan
, OUR_V2_WINSIZE
- bufsize
);
5708 void ssh_send_port_open(void *channel
, char *hostname
, int port
, char *org
)
5710 struct ssh_channel
*c
= (struct ssh_channel
*)channel
;
5713 sprintf(buf
, "Opening forwarded connection to %.512s:%d", hostname
, port
);
5716 if (ssh_version
== 1) {
5717 send_packet(SSH1_MSG_PORT_OPEN
,
5718 PKT_INT
, c
->localid
,
5721 //PKT_STR, <org:orgport>,
5724 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
5725 ssh2_pkt_addstring("direct-tcpip");
5726 ssh2_pkt_adduint32(c
->localid
);
5727 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5728 ssh2_pkt_adduint32(c
->v
.v2
.locwindow
);/* our window size */
5729 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
5730 ssh2_pkt_addstring(hostname
);
5731 ssh2_pkt_adduint32(port
);
5733 * We make up values for the originator data; partly it's
5734 * too much hassle to keep track, and partly I'm not
5735 * convinced the server should be told details like that
5736 * about my local network configuration.
5738 ssh2_pkt_addstring("client-side-connection");
5739 ssh2_pkt_adduint32(0);
5745 static Socket
ssh_socket(void)
5750 static int ssh_sendok(void)
5755 static int ssh_ldisc(int option
)
5757 if (option
== LD_ECHO
)
5759 if (option
== LD_EDIT
)
5764 static int ssh_return_exitcode(void)
5766 return ssh_exitcode
;
5769 Backend ssh_backend
= {
5776 ssh_return_exitcode
,