18 #define logevent(s) { logevent(s); \
19 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
20 { fprintf(stderr, "%s\n", s); fflush(stderr); } }
22 #define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \
23 (s ? sk_close(s), s = NULL : 0), \
24 connection_fatal msg )
26 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
27 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
28 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
29 #define SSH1_CMSG_USER 4 /* 0x4 */
30 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
31 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
32 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
33 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
34 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
35 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
36 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
37 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
38 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
39 #define SSH1_SMSG_FAILURE 15 /* 0xf */
40 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
41 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
42 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
43 #define SSH1_CMSG_EOF 19 /* 0x13 */
44 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
45 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
46 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
47 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
48 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
49 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
50 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
51 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
52 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
53 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
54 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
55 #define SSH1_MSG_IGNORE 32 /* 0x20 */
56 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
57 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
58 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
59 #define SSH1_MSG_DEBUG 36 /* 0x24 */
60 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
61 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
62 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
63 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
64 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
65 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
66 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
68 #define SSH1_AUTH_TIS 5 /* 0x5 */
69 #define SSH1_AUTH_CCARD 16 /* 0x10 */
71 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
72 /* Mask for protoflags we will echo back to server if seen */
73 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
75 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
76 #define SSH2_MSG_IGNORE 2 /* 0x2 */
77 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
78 #define SSH2_MSG_DEBUG 4 /* 0x4 */
79 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
80 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
81 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
82 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
83 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
84 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
85 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
86 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
87 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
88 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
89 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
90 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
91 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
92 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
93 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
94 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
95 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
96 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
97 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
98 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
99 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
100 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
101 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
102 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
103 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
104 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
105 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
106 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
107 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
108 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
110 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
111 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
112 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
113 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
114 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
115 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
116 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
117 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
118 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
119 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
120 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
121 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
122 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
123 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
124 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
126 static const char *const ssh2_disconnect_reasons
[] = {
128 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
129 "SSH_DISCONNECT_PROTOCOL_ERROR",
130 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
131 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
132 "SSH_DISCONNECT_MAC_ERROR",
133 "SSH_DISCONNECT_COMPRESSION_ERROR",
134 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
135 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
136 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
137 "SSH_DISCONNECT_CONNECTION_LOST",
138 "SSH_DISCONNECT_BY_APPLICATION",
139 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
140 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
141 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
142 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
145 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
146 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
147 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
148 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
150 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
153 * Various remote-bug flags.
155 #define BUG_CHOKES_ON_SSH1_IGNORE 1
156 #define BUG_SSH2_HMAC 2
158 #define GET_32BIT(cp) \
159 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
160 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
161 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
162 ((unsigned long)(unsigned char)(cp)[3]))
164 #define PUT_32BIT(cp, value) { \
165 (cp)[0] = (unsigned char)((value) >> 24); \
166 (cp)[1] = (unsigned char)((value) >> 16); \
167 (cp)[2] = (unsigned char)((value) >> 8); \
168 (cp)[3] = (unsigned char)(value); }
170 enum { PKT_END
, PKT_INT
, PKT_CHAR
, PKT_DATA
, PKT_STR
, PKT_BIGNUM
};
172 /* Coroutine mechanics for the sillier bits of the code */
173 #define crBegin1 static int crLine = 0;
174 #define crBegin2 switch(crLine) { case 0:;
175 #define crBegin crBegin1; crBegin2;
176 #define crFinish(z) } crLine = 0; return (z)
177 #define crFinishV } crLine = 0; return
178 #define crReturn(z) \
180 crLine=__LINE__; return (z); case __LINE__:;\
184 crLine=__LINE__; return; case __LINE__:;\
186 #define crStop(z) do{ crLine = 0; return (z); }while(0)
187 #define crStopV do{ crLine = 0; return; }while(0)
188 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
189 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
191 extern char *x11_init (Socket
*, char *, void *);
192 extern void x11_close (Socket
);
193 extern void x11_send (Socket
, char *, int);
194 extern void x11_invent_auth(char *, int, char *, int);
197 * Ciphers for SSH2. We miss out single-DES because it isn't
198 * supported; also 3DES and Blowfish are both done differently from
199 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
200 * endianness and different-sized keys.)
202 const static struct ssh2_ciphers
*ciphers
[] = {
208 const static struct ssh_kex
*kex_algs
[] = {
209 &ssh_diffiehellman_gex
,
210 &ssh_diffiehellman
};
212 const static struct ssh_signkey
*hostkey_algs
[] = { &ssh_rsa
, &ssh_dss
};
214 static void nullmac_key(unsigned char *key
) { }
215 static void nullmac_generate(unsigned char *blk
, int len
, unsigned long seq
) { }
216 static int nullmac_verify(unsigned char *blk
, int len
, unsigned long seq
) { return 1; }
217 const static struct ssh_mac ssh_mac_none
= {
218 nullmac_key
, nullmac_key
, nullmac_generate
, nullmac_verify
, "none", 0
220 const static struct ssh_mac
*macs
[] = {
221 &ssh_sha1
, &ssh_md5
, &ssh_mac_none
};
222 const static struct ssh_mac
*buggymacs
[] = {
223 &ssh_sha1_buggy
, &ssh_md5
, &ssh_mac_none
};
225 static void ssh_comp_none_init(void) { }
226 static int ssh_comp_none_block(unsigned char *block
, int len
,
227 unsigned char **outblock
, int *outlen
) {
230 static int ssh_comp_none_disable(void) { return 0; }
231 const static struct ssh_compress ssh_comp_none
= {
233 ssh_comp_none_init
, ssh_comp_none_block
,
234 ssh_comp_none_init
, ssh_comp_none_block
,
235 ssh_comp_none_disable
237 extern const struct ssh_compress ssh_zlib
;
238 const static struct ssh_compress
*compressions
[] = {
239 &ssh_zlib
, &ssh_comp_none
};
241 enum { /* channel types */
248 * 2-3-4 tree storing channels.
251 unsigned remoteid
, localid
;
254 struct ssh2_data_channel
{
255 unsigned char *outbuffer
;
256 unsigned outbuflen
, outbufsize
;
257 unsigned remwindow
, remmaxpkt
;
260 struct ssh_agent_channel
{
261 unsigned char *message
;
262 unsigned char msglen
[4];
263 int lensofar
, totallen
;
265 struct ssh_x11_channel
{
280 static SHA_State exhash
, exhashbase
;
282 static Socket s
= NULL
;
284 static unsigned char session_key
[32];
285 static int ssh1_compressing
;
286 static int ssh1_remote_protoflags
;
287 static int ssh1_local_protoflags
;
288 static int ssh_agentfwd_enabled
;
289 static int ssh_X11_fwd_enabled
;
290 static int ssh_remote_bugs
;
291 static const struct ssh_cipher
*cipher
= NULL
;
292 static const struct ssh2_cipher
*cscipher
= NULL
;
293 static const struct ssh2_cipher
*sccipher
= NULL
;
294 static const struct ssh_mac
*csmac
= NULL
;
295 static const struct ssh_mac
*scmac
= NULL
;
296 static const struct ssh_compress
*cscomp
= NULL
;
297 static const struct ssh_compress
*sccomp
= NULL
;
298 static const struct ssh_kex
*kex
= NULL
;
299 static const struct ssh_signkey
*hostkey
= NULL
;
300 static unsigned char ssh2_session_id
[20];
301 int (*ssh_get_line
)(const char *prompt
, char *str
, int maxlen
,
304 static char *savedhost
;
305 static int savedport
;
306 static int ssh_send_ok
;
307 static int ssh_echoing
, ssh_editing
;
309 static tree234
*ssh_channels
; /* indexed by local id */
310 static struct ssh_channel
*mainchan
; /* primary session channel */
314 SSH_STATE_BEFORE_SIZE
,
318 } ssh_state
= SSH_STATE_PREPACKET
;
320 static int size_needed
= FALSE
, eof_needed
= FALSE
;
322 static struct Packet pktin
= { 0, 0, NULL
, NULL
, 0 };
323 static struct Packet pktout
= { 0, 0, NULL
, NULL
, 0 };
324 static unsigned char *deferred_send_data
= NULL
;
325 static int deferred_len
= 0, deferred_size
= 0;
327 static int ssh_version
;
328 static void (*ssh_protocol
)(unsigned char *in
, int inlen
, int ispkt
);
329 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
);
330 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
);
331 static void ssh_size(void);
332 static void ssh_special (Telnet_Special
);
333 static void ssh2_try_send(struct ssh_channel
*c
);
334 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
, int len
);
336 static int (*s_rdpkt
)(unsigned char **data
, int *datalen
);
338 static struct rdpkt1_state_tag
{
339 long len
, pad
, biglen
, to_read
;
340 unsigned long realcrc
, gotcrc
;
346 static struct rdpkt2_state_tag
{
347 long len
, pad
, payload
, packetlen
, maclen
;
350 unsigned long incoming_sequence
;
353 static int ssh_channelcmp(void *av
, void *bv
) {
354 struct ssh_channel
*a
= (struct ssh_channel
*)av
;
355 struct ssh_channel
*b
= (struct ssh_channel
*)bv
;
356 if (a
->localid
< b
->localid
) return -1;
357 if (a
->localid
> b
->localid
) return +1;
360 static int ssh_channelfind(void *av
, void *bv
) {
361 unsigned *a
= (unsigned *)av
;
362 struct ssh_channel
*b
= (struct ssh_channel
*)bv
;
363 if (*a
< b
->localid
) return -1;
364 if (*a
> b
->localid
) return +1;
368 static int alloc_channel_id(void) {
369 const unsigned CHANNEL_NUMBER_OFFSET
= 256;
370 unsigned low
, high
, mid
;
372 struct ssh_channel
*c
;
375 * First-fit allocation of channel numbers: always pick the
376 * lowest unused one. To do this, binary-search using the
377 * counted B-tree to find the largest channel ID which is in a
378 * contiguous sequence from the beginning. (Precisely
379 * everything in that sequence must have ID equal to its tree
380 * index plus CHANNEL_NUMBER_OFFSET.)
382 tsize
= count234(ssh_channels
);
384 low
= -1; high
= tsize
;
385 while (high
- low
> 1) {
386 mid
= (high
+ low
) / 2;
387 c
= index234(ssh_channels
, mid
);
388 if (c
->localid
== mid
+ CHANNEL_NUMBER_OFFSET
)
389 low
= mid
; /* this one is fine */
391 high
= mid
; /* this one is past it */
394 * Now low points to either -1, or the tree index of the
395 * largest ID in the initial sequence.
398 unsigned i
= low
+ 1 + CHANNEL_NUMBER_OFFSET
;
399 assert(NULL
== find234(ssh_channels
, &i
, ssh_channelfind
));
401 return low
+ 1 + CHANNEL_NUMBER_OFFSET
;
404 static void c_write (char *buf
, int len
) {
405 if ((flags
& FLAG_STDERR
)) {
407 for (i
= 0; i
< len
; i
++)
409 fputc(buf
[i
], stderr
);
412 from_backend(1, buf
, len
);
415 static void c_write_untrusted(char *buf
, int len
) {
417 for (i
= 0; i
< len
; i
++) {
420 else if ((buf
[i
] & 0x60) || (buf
[i
] == '\r'))
425 static void c_write_str (char *buf
) {
426 c_write(buf
, strlen(buf
));
430 * Collect incoming data in the incoming packet buffer.
431 * Decipher and verify the packet when it is completely read.
432 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
433 * Update the *data and *datalen variables.
434 * Return the additional nr of bytes needed, or 0 when
435 * a complete packet is available.
437 static int ssh1_rdpkt(unsigned char **data
, int *datalen
)
439 struct rdpkt1_state_tag
*st
= &rdpkt1_state
;
448 for (st
->i
= st
->len
= 0; st
->i
< 4; st
->i
++) {
449 while ((*datalen
) == 0)
451 st
->len
= (st
->len
<< 8) + **data
;
452 (*data
)++, (*datalen
)--;
456 if (st
->len
== 0x52656d6f) { /* "Remo"te server has closed ... */
457 st
->len
= 0x300; /* big enough to carry to end */
461 st
->pad
= 8 - (st
->len
% 8);
462 st
->biglen
= st
->len
+ st
->pad
;
463 pktin
.length
= st
->len
- 5;
465 if (pktin
.maxlen
< st
->biglen
) {
466 pktin
.maxlen
= st
->biglen
;
467 pktin
.data
= (pktin
.data
== NULL ?
smalloc(st
->biglen
+APIEXTRA
) :
468 srealloc(pktin
.data
, st
->biglen
+APIEXTRA
));
470 fatalbox("Out of memory");
473 st
->to_read
= st
->biglen
;
475 while (st
->to_read
> 0) {
476 st
->chunk
= st
->to_read
;
477 while ((*datalen
) == 0)
478 crReturn(st
->to_read
);
479 if (st
->chunk
> (*datalen
))
480 st
->chunk
= (*datalen
);
481 memcpy(st
->p
, *data
, st
->chunk
);
483 *datalen
-= st
->chunk
;
485 st
->to_read
-= st
->chunk
;
489 cipher
->decrypt(pktin
.data
, st
->biglen
);
491 debug(("Got packet len=%d pad=%d\r\n", st
->len
, st
->pad
));
492 for (st
->i
= 0; st
->i
< st
->biglen
; st
->i
++)
493 debug((" %02x", (unsigned char)pktin
.data
[st
->i
]));
497 st
->realcrc
= crc32(pktin
.data
, st
->biglen
-4);
498 st
->gotcrc
= GET_32BIT(pktin
.data
+st
->biglen
-4);
499 if (st
->gotcrc
!= st
->realcrc
) {
500 bombout(("Incorrect CRC received on packet"));
504 pktin
.body
= pktin
.data
+ st
->pad
+ 1;
506 if (ssh1_compressing
) {
507 unsigned char *decompblk
;
512 debug(("Packet payload pre-decompression:\n"));
513 for (i
= -1; i
< pktin
.length
; i
++)
514 debug((" %02x", (unsigned char)pktin
.body
[i
]));
518 zlib_decompress_block(pktin
.body
-1, pktin
.length
+1,
519 &decompblk
, &decomplen
);
521 if (pktin
.maxlen
< st
->pad
+ decomplen
) {
522 pktin
.maxlen
= st
->pad
+ decomplen
;
523 pktin
.data
= srealloc(pktin
.data
, pktin
.maxlen
+APIEXTRA
);
524 pktin
.body
= pktin
.data
+ st
->pad
+ 1;
526 fatalbox("Out of memory");
529 memcpy(pktin
.body
-1, decompblk
, decomplen
);
531 pktin
.length
= decomplen
-1;
535 debug(("Packet payload post-decompression:\n"));
536 for (i
= -1; i
< pktin
.length
; i
++)
537 debug((" %02x", (unsigned char)pktin
.body
[i
]));
543 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
544 pktin
.type
== SSH1_SMSG_STDERR_DATA
||
545 pktin
.type
== SSH1_MSG_DEBUG
||
546 pktin
.type
== SSH1_SMSG_AUTH_TIS_CHALLENGE
||
547 pktin
.type
== SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
548 long strlen
= GET_32BIT(pktin
.body
);
549 if (strlen
+ 4 != pktin
.length
) {
550 bombout(("Received data packet with bogus string length"));
555 pktin
.type
= pktin
.body
[-1];
557 if (pktin
.type
== SSH1_MSG_DEBUG
) {
558 /* log debug message */
560 int strlen
= GET_32BIT(pktin
.body
);
561 strcpy(buf
, "Remote: ");
562 if (strlen
> 70) strlen
= 70;
563 memcpy(buf
+8, pktin
.body
+4, strlen
);
564 buf
[8+strlen
] = '\0';
567 } else if (pktin
.type
== SSH1_MSG_IGNORE
) {
572 if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
573 /* log reason code in disconnect message */
575 unsigned msglen
= GET_32BIT(pktin
.body
);
577 strcpy(buf
, "Remote sent disconnect: ");
578 nowlen
= strlen(buf
);
579 if (msglen
> sizeof(buf
)-nowlen
-1)
580 msglen
= sizeof(buf
)-nowlen
-1;
581 memcpy(buf
+nowlen
, pktin
.body
+4, msglen
);
582 buf
[nowlen
+msglen
] = '\0';
589 static int ssh2_rdpkt(unsigned char **data
, int *datalen
)
591 struct rdpkt2_state_tag
*st
= &rdpkt2_state
;
599 st
->cipherblk
= sccipher
->blksize
;
602 if (st
->cipherblk
< 8)
605 if (pktin
.maxlen
< st
->cipherblk
) {
606 pktin
.maxlen
= st
->cipherblk
;
607 pktin
.data
= (pktin
.data
== NULL ?
smalloc(st
->cipherblk
+APIEXTRA
) :
608 srealloc(pktin
.data
, st
->cipherblk
+APIEXTRA
));
610 fatalbox("Out of memory");
614 * Acquire and decrypt the first block of the packet. This will
615 * contain the length and padding details.
617 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
618 while ((*datalen
) == 0)
619 crReturn(st
->cipherblk
-st
->i
);
620 pktin
.data
[st
->i
] = *(*data
)++;
624 if (!memcmp(pktin
.data
, "Remo", 4)) {/* "Remo"te server has closed ... */
629 sccipher
->decrypt(pktin
.data
, st
->cipherblk
);
632 * Now get the length and padding figures.
634 st
->len
= GET_32BIT(pktin
.data
);
635 st
->pad
= pktin
.data
[4];
638 * This enables us to deduce the payload length.
640 st
->payload
= st
->len
- st
->pad
- 1;
642 pktin
.length
= st
->payload
+ 5;
645 * So now we can work out the total packet length.
647 st
->packetlen
= st
->len
+ 4;
648 st
->maclen
= scmac ? scmac
->len
: 0;
651 * Adjust memory allocation if packet is too big.
653 if (pktin
.maxlen
< st
->packetlen
+st
->maclen
) {
654 pktin
.maxlen
= st
->packetlen
+st
->maclen
;
655 pktin
.data
= (pktin
.data
== NULL ?
smalloc(pktin
.maxlen
+APIEXTRA
) :
656 srealloc(pktin
.data
, pktin
.maxlen
+APIEXTRA
));
658 fatalbox("Out of memory");
662 * Read and decrypt the remainder of the packet.
664 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
; st
->i
++) {
665 while ((*datalen
) == 0)
666 crReturn(st
->packetlen
+ st
->maclen
- st
->i
);
667 pktin
.data
[st
->i
] = *(*data
)++;
670 /* Decrypt everything _except_ the MAC. */
672 sccipher
->decrypt(pktin
.data
+ st
->cipherblk
,
673 st
->packetlen
- st
->cipherblk
);
676 debug(("Got packet len=%d pad=%d\r\n", st
->len
, st
->pad
));
677 for (st
->i
= 0; st
->i
< st
->packetlen
; st
->i
++)
678 debug((" %02x", (unsigned char)pktin
.data
[st
->i
]));
685 if (scmac
&& !scmac
->verify(pktin
.data
, st
->len
+4, st
->incoming_sequence
)) {
686 bombout(("Incorrect MAC received on packet"));
689 st
->incoming_sequence
++; /* whether or not we MACed */
692 * Decompress packet payload.
695 unsigned char *newpayload
;
697 if (sccomp
&& sccomp
->decompress(pktin
.data
+5, pktin
.length
-5,
698 &newpayload
, &newlen
)) {
699 if (pktin
.maxlen
< newlen
+5) {
700 pktin
.maxlen
= newlen
+5;
701 pktin
.data
= (pktin
.data
== NULL ?
smalloc(pktin
.maxlen
+APIEXTRA
) :
702 srealloc(pktin
.data
, pktin
.maxlen
+APIEXTRA
));
704 fatalbox("Out of memory");
706 pktin
.length
= 5 + newlen
;
707 memcpy(pktin
.data
+5, newpayload
, newlen
);
709 debug(("Post-decompression payload:\r\n"));
710 for (st
->i
= 0; st
->i
< newlen
; st
->i
++)
711 debug((" %02x", (unsigned char)pktin
.data
[5+st
->i
]));
720 pktin
.type
= pktin
.data
[5];
722 if (pktin
.type
== SSH2_MSG_IGNORE
|| pktin
.type
== SSH2_MSG_DEBUG
)
723 goto next_packet
; /* FIXME: print DEBUG message */
725 if (pktin
.type
== SSH2_MSG_DISCONNECT
) {
726 /* log reason code in disconnect message */
728 int reason
= GET_32BIT(pktin
.data
+6);
729 unsigned msglen
= GET_32BIT(pktin
.data
+10);
731 if (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) {
732 sprintf(buf
, "Received disconnect message (%s)",
733 ssh2_disconnect_reasons
[reason
]);
735 sprintf(buf
, "Received disconnect message (unknown type %d)", reason
);
738 strcpy(buf
, "Disconnection message text: ");
739 nowlen
= strlen(buf
);
740 if (msglen
> sizeof(buf
)-nowlen
-1)
741 msglen
= sizeof(buf
)-nowlen
-1;
742 memcpy(buf
+nowlen
, pktin
.data
+14, msglen
);
743 buf
[nowlen
+msglen
] = '\0';
750 static void ssh1_pktout_size(int len
) {
753 len
+= 5; /* type and CRC */
757 pktout
.length
= len
-5;
758 if (pktout
.maxlen
< biglen
) {
759 pktout
.maxlen
= biglen
;
761 /* Allocate enough buffer space for extra block
762 * for MS CryptEncrypt() */
763 pktout
.data
= (pktout
.data
== NULL ?
smalloc(biglen
+12) :
764 srealloc(pktout
.data
, biglen
+12));
766 pktout
.data
= (pktout
.data
== NULL ?
smalloc(biglen
+4) :
767 srealloc(pktout
.data
, biglen
+4));
770 fatalbox("Out of memory");
772 pktout
.body
= pktout
.data
+4+pad
+1;
775 static void s_wrpkt_start(int type
, int len
) {
776 ssh1_pktout_size(len
);
780 static int s_wrpkt_prepare(void) {
781 int pad
, len
, biglen
, i
;
784 pktout
.body
[-1] = pktout
.type
;
787 debug(("Packet payload pre-compression:\n"));
788 for (i
= -1; i
< pktout
.length
; i
++)
789 debug((" %02x", (unsigned char)pktout
.body
[i
]));
793 if (ssh1_compressing
) {
794 unsigned char *compblk
;
796 zlib_compress_block(pktout
.body
-1, pktout
.length
+1,
798 ssh1_pktout_size(complen
-1);
799 memcpy(pktout
.body
-1, compblk
, complen
);
802 debug(("Packet payload post-compression:\n"));
803 for (i
= -1; i
< pktout
.length
; i
++)
804 debug((" %02x", (unsigned char)pktout
.body
[i
]));
809 len
= pktout
.length
+ 5; /* type and CRC */
813 for (i
=0; i
<pad
; i
++)
814 pktout
.data
[i
+4] = random_byte();
815 crc
= crc32(pktout
.data
+4, biglen
-4);
816 PUT_32BIT(pktout
.data
+biglen
, crc
);
817 PUT_32BIT(pktout
.data
, len
);
820 debug(("Sending packet len=%d\r\n", biglen
+4));
821 for (i
= 0; i
< biglen
+4; i
++)
822 debug((" %02x", (unsigned char)pktout
.data
[i
]));
826 cipher
->encrypt(pktout
.data
+4, biglen
);
831 static void s_wrpkt(void) {
833 len
= s_wrpkt_prepare();
834 sk_write(s
, pktout
.data
, len
);
837 static void s_wrpkt_defer(void) {
839 len
= s_wrpkt_prepare();
840 if (deferred_len
+ len
> deferred_size
) {
841 deferred_size
= deferred_len
+ len
+ 128;
842 deferred_send_data
= srealloc(deferred_send_data
, deferred_size
);
844 memcpy(deferred_send_data
+deferred_len
, pktout
.data
, len
);
849 * Construct a packet with the specified contents.
851 static void construct_packet(int pkttype
, va_list ap1
, va_list ap2
)
853 unsigned char *p
, *argp
, argchar
;
854 unsigned long argint
;
855 int pktlen
, argtype
, arglen
;
859 while ((argtype
= va_arg(ap1
, int)) != PKT_END
) {
862 (void) va_arg(ap1
, int);
866 (void) va_arg(ap1
, char);
870 (void) va_arg(ap1
, unsigned char *);
871 arglen
= va_arg(ap1
, int);
875 argp
= va_arg(ap1
, unsigned char *);
876 arglen
= strlen(argp
);
877 pktlen
+= 4 + arglen
;
880 bn
= va_arg(ap1
, Bignum
);
881 pktlen
+= ssh1_bignum_length(bn
);
888 s_wrpkt_start(pkttype
, pktlen
);
891 while ((argtype
= va_arg(ap2
, int)) != PKT_END
) {
894 argint
= va_arg(ap2
, int);
895 PUT_32BIT(p
, argint
);
899 argchar
= va_arg(ap2
, unsigned char);
904 argp
= va_arg(ap2
, unsigned char *);
905 arglen
= va_arg(ap2
, int);
906 memcpy(p
, argp
, arglen
);
910 argp
= va_arg(ap2
, unsigned char *);
911 arglen
= strlen(argp
);
912 PUT_32BIT(p
, arglen
);
913 memcpy(p
+ 4, argp
, arglen
);
917 bn
= va_arg(ap2
, Bignum
);
918 p
+= ssh1_write_bignum(p
, bn
);
924 static void send_packet(int pkttype
, ...) {
926 va_start(ap1
, pkttype
);
927 va_start(ap2
, pkttype
);
928 construct_packet(pkttype
, ap1
, ap2
);
932 static void defer_packet(int pkttype
, ...) {
934 va_start(ap1
, pkttype
);
935 va_start(ap2
, pkttype
);
936 construct_packet(pkttype
, ap1
, ap2
);
940 static int ssh_versioncmp(char *a
, char *b
) {
942 unsigned long av
, bv
;
944 av
= strtoul(a
, &ae
, 10);
945 bv
= strtoul(b
, &be
, 10);
946 if (av
!= bv
) return (av
< bv ?
-1 : +1);
947 if (*ae
== '.') ae
++;
948 if (*be
== '.') be
++;
949 av
= strtoul(ae
, &ae
, 10);
950 bv
= strtoul(be
, &be
, 10);
951 if (av
!= bv
) return (av
< bv ?
-1 : +1);
957 * Utility routines for putting an SSH-protocol `string' and
958 * `uint32' into a SHA state.
961 static void sha_string(SHA_State
*s
, void *str
, int len
) {
962 unsigned char lenblk
[4];
963 PUT_32BIT(lenblk
, len
);
964 SHA_Bytes(s
, lenblk
, 4);
965 SHA_Bytes(s
, str
, len
);
968 static void sha_uint32(SHA_State
*s
, unsigned i
) {
969 unsigned char intblk
[4];
970 PUT_32BIT(intblk
, i
);
971 SHA_Bytes(s
, intblk
, 4);
975 * SSH2 packet construction functions.
977 static void ssh2_pkt_ensure(int length
) {
978 if (pktout
.maxlen
< length
) {
979 pktout
.maxlen
= length
+ 256;
980 pktout
.data
= (pktout
.data
== NULL ?
smalloc(pktout
.maxlen
+APIEXTRA
) :
981 srealloc(pktout
.data
, pktout
.maxlen
+APIEXTRA
));
983 fatalbox("Out of memory");
986 static void ssh2_pkt_adddata(void *data
, int len
) {
987 pktout
.length
+= len
;
988 ssh2_pkt_ensure(pktout
.length
);
989 memcpy(pktout
.data
+pktout
.length
-len
, data
, len
);
991 static void ssh2_pkt_addbyte(unsigned char byte
) {
992 ssh2_pkt_adddata(&byte
, 1);
994 static void ssh2_pkt_init(int pkt_type
) {
996 ssh2_pkt_addbyte((unsigned char)pkt_type
);
998 static void ssh2_pkt_addbool(unsigned char value
) {
999 ssh2_pkt_adddata(&value
, 1);
1001 static void ssh2_pkt_adduint32(unsigned long value
) {
1003 PUT_32BIT(x
, value
);
1004 ssh2_pkt_adddata(x
, 4);
1006 static void ssh2_pkt_addstring_start(void) {
1007 ssh2_pkt_adduint32(0);
1008 pktout
.savedpos
= pktout
.length
;
1010 static void ssh2_pkt_addstring_str(char *data
) {
1011 ssh2_pkt_adddata(data
, strlen(data
));
1012 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
1013 pktout
.length
- pktout
.savedpos
);
1015 static void ssh2_pkt_addstring_data(char *data
, int len
) {
1016 ssh2_pkt_adddata(data
, len
);
1017 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
1018 pktout
.length
- pktout
.savedpos
);
1020 static void ssh2_pkt_addstring(char *data
) {
1021 ssh2_pkt_addstring_start();
1022 ssh2_pkt_addstring_str(data
);
1024 static char *ssh2_mpint_fmt(Bignum b
, int *len
) {
1026 int i
, n
= (bignum_bitcount(b
)+7)/8;
1029 fatalbox("out of memory");
1031 for (i
= 1; i
<= n
; i
++)
1032 p
[i
] = bignum_byte(b
, n
-i
);
1034 while (i
<= n
&& p
[i
] == 0 && (p
[i
+1] & 0x80) == 0)
1036 memmove(p
, p
+i
, n
+1-i
);
1040 static void ssh2_pkt_addmp(Bignum b
) {
1043 p
= ssh2_mpint_fmt(b
, &len
);
1044 ssh2_pkt_addstring_start();
1045 ssh2_pkt_addstring_data(p
, len
);
1050 * Construct an SSH2 final-form packet: compress it, encrypt it,
1051 * put the MAC on it. Final packet, ready to be sent, is stored in
1052 * pktout.data. Total length is returned.
1054 static int ssh2_pkt_construct(void) {
1055 int cipherblk
, maclen
, padding
, i
;
1056 static unsigned long outgoing_sequence
= 0;
1059 * Compress packet payload.
1062 debug(("Pre-compression payload:\r\n"));
1063 for (i
= 5; i
< pktout
.length
; i
++)
1064 debug((" %02x", (unsigned char)pktout
.data
[i
]));
1068 unsigned char *newpayload
;
1070 if (cscomp
&& cscomp
->compress(pktout
.data
+5, pktout
.length
-5,
1071 &newpayload
, &newlen
)) {
1073 ssh2_pkt_adddata(newpayload
, newlen
);
1079 * Add padding. At least four bytes, and must also bring total
1080 * length (minus MAC) up to a multiple of the block size.
1082 cipherblk
= cscipher ? cscipher
->blksize
: 8; /* block size */
1083 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
1085 padding
+= (cipherblk
- (pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
1086 maclen
= csmac ? csmac
->len
: 0;
1087 ssh2_pkt_ensure(pktout
.length
+ padding
+ maclen
);
1088 pktout
.data
[4] = padding
;
1089 for (i
= 0; i
< padding
; i
++)
1090 pktout
.data
[pktout
.length
+ i
] = random_byte();
1091 PUT_32BIT(pktout
.data
, pktout
.length
+ padding
- 4);
1093 csmac
->generate(pktout
.data
, pktout
.length
+ padding
,
1095 outgoing_sequence
++; /* whether or not we MACed */
1098 debug(("Sending packet len=%d\r\n", pktout
.length
+padding
));
1099 for (i
= 0; i
< pktout
.length
+padding
; i
++)
1100 debug((" %02x", (unsigned char)pktout
.data
[i
]));
1105 cscipher
->encrypt(pktout
.data
, pktout
.length
+ padding
);
1107 /* Ready-to-send packet starts at pktout.data. We return length. */
1108 return pktout
.length
+ padding
+ maclen
;
1112 * Construct and send an SSH2 packet immediately.
1114 static void ssh2_pkt_send(void) {
1115 int len
= ssh2_pkt_construct();
1116 sk_write(s
, pktout
.data
, len
);
1120 * Construct an SSH2 packet and add it to a deferred data block.
1121 * Useful for sending multiple packets in a single sk_write() call,
1122 * to prevent a traffic-analysing listener from being able to work
1123 * out the length of any particular packet (such as the password
1126 * Note that because SSH2 sequence-numbers its packets, this can
1127 * NOT be used as an m4-style `defer' allowing packets to be
1128 * constructed in one order and sent in another.
1130 static void ssh2_pkt_defer(void) {
1131 int len
= ssh2_pkt_construct();
1132 if (deferred_len
+ len
> deferred_size
) {
1133 deferred_size
= deferred_len
+ len
+ 128;
1134 deferred_send_data
= srealloc(deferred_send_data
, deferred_size
);
1136 memcpy(deferred_send_data
+deferred_len
, pktout
.data
, len
);
1137 deferred_len
+= len
;
1141 * Send the whole deferred data block constructed by
1142 * ssh2_pkt_defer() or SSH1's defer_packet().
1144 static void ssh_pkt_defersend(void) {
1145 sk_write(s
, deferred_send_data
, deferred_len
);
1146 deferred_len
= deferred_size
= 0;
1147 sfree(deferred_send_data
);
1148 deferred_send_data
= NULL
;
1152 void bndebug(char *string
, Bignum b
) {
1155 p
= ssh2_mpint_fmt(b
, &len
);
1156 debug(("%s", string
));
1157 for (i
= 0; i
< len
; i
++)
1158 debug((" %02x", p
[i
]));
1164 static void sha_mpint(SHA_State
*s
, Bignum b
) {
1167 p
= ssh2_mpint_fmt(b
, &len
);
1168 sha_string(s
, p
, len
);
1173 * SSH2 packet decode functions.
1175 static unsigned long ssh2_pkt_getuint32(void) {
1176 unsigned long value
;
1177 if (pktin
.length
- pktin
.savedpos
< 4)
1178 return 0; /* arrgh, no way to decline (FIXME?) */
1179 value
= GET_32BIT(pktin
.data
+pktin
.savedpos
);
1180 pktin
.savedpos
+= 4;
1183 static int ssh2_pkt_getbool(void) {
1184 unsigned long value
;
1185 if (pktin
.length
- pktin
.savedpos
< 1)
1186 return 0; /* arrgh, no way to decline (FIXME?) */
1187 value
= pktin
.data
[pktin
.savedpos
] != 0;
1191 static void ssh2_pkt_getstring(char **p
, int *length
) {
1193 if (pktin
.length
- pktin
.savedpos
< 4)
1195 *length
= GET_32BIT(pktin
.data
+pktin
.savedpos
);
1196 pktin
.savedpos
+= 4;
1197 if (pktin
.length
- pktin
.savedpos
< *length
)
1199 *p
= pktin
.data
+pktin
.savedpos
;
1200 pktin
.savedpos
+= *length
;
1202 static Bignum
ssh2_pkt_getmp(void) {
1207 ssh2_pkt_getstring(&p
, &length
);
1211 bombout(("internal error: Can't handle negative mpints"));
1214 b
= bignum_from_bytes(p
, length
);
1219 * Examine the remote side's version string and compare it against
1220 * a list of known buggy implementations.
1222 static void ssh_detect_bugs(char *vstring
) {
1223 char *imp
; /* pointer to implementation part */
1225 imp
+= strcspn(imp
, "-");
1227 imp
+= strcspn(imp
, "-");
1230 ssh_remote_bugs
= 0;
1232 if (!strcmp(imp
, "1.2.18") || !strcmp(imp
, "1.2.19") ||
1233 !strcmp(imp
, "1.2.20") || !strcmp(imp
, "1.2.21") ||
1234 !strcmp(imp
, "1.2.22")) {
1236 * These versions don't support SSH1_MSG_IGNORE, so we have
1237 * to use a different defence against password length
1240 ssh_remote_bugs
|= BUG_CHOKES_ON_SSH1_IGNORE
;
1241 logevent("We believe remote version has SSH1 ignore bug");
1244 if (!strncmp(imp
, "2.1.0", 5) || !strncmp(imp
, "2.0.", 4) ||
1245 !strncmp(imp
, "2.2.0", 5) || !strncmp(imp
, "2.3.0", 5) ||
1246 !strncmp(imp
, "2.1 ", 4)) {
1248 * These versions have the HMAC bug.
1250 ssh_remote_bugs
|= BUG_SSH2_HMAC
;
1251 logevent("We believe remote version has SSH2 HMAC bug");
1255 static int do_ssh_init(unsigned char c
) {
1257 static char version
[10];
1258 static char *vstring
;
1259 static int vstrsize
;
1265 /* Search for the string "SSH-" in the input. */
1268 static const int transS
[] = { 1, 2, 2, 1 };
1269 static const int transH
[] = { 0, 0, 3, 0 };
1270 static const int transminus
[] = { 0, 0, 0, -1 };
1271 if (c
== 'S') i
= transS
[i
];
1272 else if (c
== 'H') i
= transH
[i
];
1273 else if (c
== '-') i
= transminus
[i
];
1277 crReturn(1); /* get another character */
1280 vstring
= smalloc(16);
1282 strcpy(vstring
, "SSH-");
1286 crReturn(1); /* get another char */
1287 if (vslen
>= vstrsize
-1) {
1289 vstring
= srealloc(vstring
, vstrsize
);
1291 vstring
[vslen
++] = c
;
1296 } else if (i
< sizeof(version
)-1)
1303 ssh_agentfwd_enabled
= FALSE
;
1304 rdpkt2_state
.incoming_sequence
= 0;
1307 vlog
= smalloc(20 + vslen
);
1308 sprintf(vlog
, "Server version: %s", vstring
);
1309 ssh_detect_bugs(vstring
);
1310 vlog
[strcspn(vlog
, "\r\n")] = '\0';
1315 * Server version "1.99" means we can choose whether we use v1
1316 * or v2 protocol. Choice is based on cfg.sshprot.
1318 if (ssh_versioncmp(version
, cfg
.sshprot
== 1 ?
"2.0" : "1.99") >= 0) {
1320 * This is a v2 server. Begin v2 protocol.
1322 char verstring
[80], vlog
[100];
1323 sprintf(verstring
, "SSH-2.0-%s", sshver
);
1324 SHA_Init(&exhashbase
);
1326 * Hash our version string and their version string.
1328 sha_string(&exhashbase
, verstring
, strlen(verstring
));
1329 sha_string(&exhashbase
, vstring
, strcspn(vstring
, "\r\n"));
1330 sprintf(vlog
, "We claim version: %s", verstring
);
1332 strcat(verstring
, "\n");
1333 logevent("Using SSH protocol version 2");
1334 sk_write(s
, verstring
, strlen(verstring
));
1335 ssh_protocol
= ssh2_protocol
;
1337 s_rdpkt
= ssh2_rdpkt
;
1340 * This is a v1 server. Begin v1 protocol.
1342 char verstring
[80], vlog
[100];
1343 sprintf(verstring
, "SSH-%s-%s",
1344 (ssh_versioncmp(version
, "1.5") <= 0 ? version
: "1.5"),
1346 sprintf(vlog
, "We claim version: %s", verstring
);
1348 strcat(verstring
, "\n");
1349 logevent("Using SSH protocol version 1");
1350 sk_write(s
, verstring
, strlen(verstring
));
1351 ssh_protocol
= ssh1_protocol
;
1353 s_rdpkt
= ssh1_rdpkt
;
1355 ssh_state
= SSH_STATE_BEFORE_SIZE
;
1362 static void ssh_gotdata(unsigned char *data
, int datalen
)
1367 * To begin with, feed the characters one by one to the
1368 * protocol initialisation / selection function do_ssh_init().
1369 * When that returns 0, we're done with the initial greeting
1370 * exchange and can move on to packet discipline.
1375 crReturnV
; /* more data please */
1376 ret
= do_ssh_init(*data
);
1383 * We emerge from that loop when the initial negotiation is
1384 * over and we have selected an s_rdpkt function. Now pass
1385 * everything to s_rdpkt, and then pass the resulting packets
1386 * to the proper protocol handler.
1391 while (datalen
> 0) {
1392 if ( s_rdpkt(&data
, &datalen
) == 0 ) {
1393 ssh_protocol(NULL
, 0, 1);
1394 if (ssh_state
== SSH_STATE_CLOSED
) {
1404 static int ssh_closing (Plug plug
, char *error_msg
, int error_code
, int calling_back
) {
1405 ssh_state
= SSH_STATE_CLOSED
;
1409 /* A socket error has occurred. */
1410 connection_fatal (error_msg
);
1412 /* Otherwise, the remote side closed the connection normally. */
1417 static int ssh_receive(Plug plug
, int urgent
, char *data
, int len
) {
1418 ssh_gotdata (data
, len
);
1419 if (ssh_state
== SSH_STATE_CLOSED
) {
1430 * Connect to specified host and port.
1431 * Returns an error message, or NULL on success.
1432 * Also places the canonical host name into `realhost'.
1434 static char *connect_to_host(char *host
, int port
, char **realhost
)
1436 static struct plug_function_table fn_table
= {
1439 }, *fn_table_ptr
= &fn_table
;
1448 savedhost
= smalloc(1+strlen(host
));
1450 fatalbox("Out of memory");
1451 strcpy(savedhost
, host
);
1454 port
= 22; /* default ssh port */
1467 addr
= sk_namelookup(host
, realhost
);
1468 if ( (err
= sk_addr_error(addr
)) )
1478 s
= sk_new(addr
, port
, 0, 1, &fn_table_ptr
);
1479 if ( (err
= sk_socket_error(s
)) )
1483 sk_write(s
, "connect ", 8);
1484 sk_write(s
, FWhost
, strlen(FWhost
));
1487 sprintf(buf
, " %d\n", FWport
);
1488 sk_write(s
, buf
, strlen(buf
));
1496 * Handle the key exchange and user authentication phases.
1498 static int do_ssh1_login(unsigned char *in
, int inlen
, int ispkt
)
1501 unsigned char *rsabuf
, *keystr1
, *keystr2
;
1502 unsigned char cookie
[8];
1503 struct RSAKey servkey
, hostkey
;
1504 struct MD5Context md5c
;
1505 static unsigned long supported_ciphers_mask
, supported_auths_mask
;
1506 static int tried_publickey
;
1507 static unsigned char session_id
[16];
1509 static char username
[100];
1513 if (!ispkt
) crWaitUntil(ispkt
);
1515 if (pktin
.type
!= SSH1_SMSG_PUBLIC_KEY
) {
1516 bombout(("Public key packet not received"));
1520 logevent("Received public keys");
1522 memcpy(cookie
, pktin
.body
, 8);
1524 i
= makekey(pktin
.body
+8, &servkey
, &keystr1
, 0);
1525 j
= makekey(pktin
.body
+8+i
, &hostkey
, &keystr2
, 0);
1528 * Log the host key fingerprint.
1532 logevent("Host key fingerprint is:");
1533 strcpy(logmsg
, " ");
1534 hostkey
.comment
= NULL
;
1535 rsa_fingerprint(logmsg
+strlen(logmsg
), sizeof(logmsg
)-strlen(logmsg
),
1540 ssh1_remote_protoflags
= GET_32BIT(pktin
.body
+8+i
+j
);
1541 supported_ciphers_mask
= GET_32BIT(pktin
.body
+12+i
+j
);
1542 supported_auths_mask
= GET_32BIT(pktin
.body
+16+i
+j
);
1544 ssh1_local_protoflags
= ssh1_remote_protoflags
& SSH1_PROTOFLAGS_SUPPORTED
;
1545 ssh1_local_protoflags
|= SSH1_PROTOFLAG_SCREEN_NUMBER
;
1548 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
1549 MD5Update(&md5c
, keystr1
, servkey
.bytes
);
1550 MD5Update(&md5c
, pktin
.body
, 8);
1551 MD5Final(session_id
, &md5c
);
1553 for (i
=0; i
<32; i
++)
1554 session_key
[i
] = random_byte();
1556 len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
1558 rsabuf
= smalloc(len
);
1560 fatalbox("Out of memory");
1563 * Verify the host key.
1567 * First format the key into a string.
1569 int len
= rsastr_len(&hostkey
);
1570 char fingerprint
[100];
1571 char *keystr
= smalloc(len
);
1573 fatalbox("Out of memory");
1574 rsastr_fmt(keystr
, &hostkey
);
1575 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
1576 verify_ssh_host_key(savedhost
, savedport
, "rsa", keystr
, fingerprint
);
1580 for (i
=0; i
<32; i
++) {
1581 rsabuf
[i
] = session_key
[i
];
1583 rsabuf
[i
] ^= session_id
[i
];
1586 if (hostkey
.bytes
> servkey
.bytes
) {
1587 rsaencrypt(rsabuf
, 32, &servkey
);
1588 rsaencrypt(rsabuf
, servkey
.bytes
, &hostkey
);
1590 rsaencrypt(rsabuf
, 32, &hostkey
);
1591 rsaencrypt(rsabuf
, hostkey
.bytes
, &servkey
);
1594 logevent("Encrypted session key");
1596 switch (cfg
.cipher
) {
1597 case CIPHER_BLOWFISH
: cipher_type
= SSH_CIPHER_BLOWFISH
; break;
1598 case CIPHER_DES
: cipher_type
= SSH_CIPHER_DES
; break;
1599 case CIPHER_3DES
: cipher_type
= SSH_CIPHER_3DES
; break;
1601 c_write_str("AES not supported in SSH1, falling back to 3DES\r\n");
1602 cipher_type
= SSH_CIPHER_3DES
;
1605 if ((supported_ciphers_mask
& (1 << cipher_type
)) == 0) {
1606 c_write_str("Selected cipher not supported, falling back to 3DES\r\n");
1607 cipher_type
= SSH_CIPHER_3DES
;
1608 if ((supported_ciphers_mask
& (1 << cipher_type
)) == 0) {
1609 bombout(("Server violates SSH 1 protocol by "
1610 "not supporting 3DES encryption"));
1614 switch (cipher_type
) {
1615 case SSH_CIPHER_3DES
: logevent("Using 3DES encryption"); break;
1616 case SSH_CIPHER_DES
: logevent("Using single-DES encryption"); break;
1617 case SSH_CIPHER_BLOWFISH
: logevent("Using Blowfish encryption"); break;
1620 send_packet(SSH1_CMSG_SESSION_KEY
,
1621 PKT_CHAR
, cipher_type
,
1622 PKT_DATA
, cookie
, 8,
1623 PKT_CHAR
, (len
*8) >> 8, PKT_CHAR
, (len
*8) & 0xFF,
1624 PKT_DATA
, rsabuf
, len
,
1625 PKT_INT
, ssh1_local_protoflags
,
1628 logevent("Trying to enable encryption...");
1632 cipher
= cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
1633 cipher_type
== SSH_CIPHER_DES ?
&ssh_des
:
1635 cipher
->sesskey(session_key
);
1639 if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1640 bombout(("Encryption not successfully enabled"));
1644 logevent("Successfully started encryption");
1650 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
1652 if (!ssh_get_line("login as: ",
1653 username
, sizeof(username
), FALSE
)) {
1655 * get_line failed to get a username.
1658 logevent("No username provided. Abandoning session.");
1659 ssh_state
= SSH_STATE_CLOSED
;
1663 c_write_str("login as: ");
1666 crWaitUntil(!ispkt
);
1667 while (inlen
--) switch (c
= *in
++) {
1674 c_write_str("\b \b");
1680 c_write_str("\b \b");
1689 if (((c
>= ' ' && c
<= '~') ||
1690 ((unsigned char)c
>= 160)) && pos
< 40) {
1691 username
[pos
++] = c
;
1697 c_write_str("\r\n");
1698 username
[strcspn(username
, "\n\r")] = '\0';
1701 strncpy(username
, cfg
.username
, 99);
1702 username
[99] = '\0';
1705 send_packet(SSH1_CMSG_USER
, PKT_STR
, username
, PKT_END
);
1707 char userlog
[22+sizeof(username
)];
1708 sprintf(userlog
, "Sent username \"%s\"", username
);
1710 if (flags
& FLAG_INTERACTIVE
&&
1711 (!((flags
& FLAG_STDERR
) && (flags
& FLAG_VERBOSE
)))) {
1712 strcat(userlog
, "\r\n");
1713 c_write_str(userlog
);
1720 tried_publickey
= 0;
1722 while (pktin
.type
== SSH1_SMSG_FAILURE
) {
1723 static char password
[100];
1724 static char prompt
[200];
1727 static int pwpkt_type
;
1729 * Show password prompt, having first obtained it via a TIS
1730 * or CryptoCard exchange if we're doing TIS or CryptoCard
1733 pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
1734 if (agent_exists()) {
1736 * Attempt RSA authentication using Pageant.
1738 static unsigned char request
[5], *response
, *p
;
1739 static int responselen
;
1740 static int i
, nkeys
;
1741 static int authed
= FALSE
;
1744 logevent("Pageant is running. Requesting keys.");
1746 /* Request the keys held by the agent. */
1747 PUT_32BIT(request
, 1);
1748 request
[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES
;
1749 agent_query(request
, 5, &r
, &responselen
);
1750 response
= (unsigned char *)r
;
1751 if (response
&& responselen
>= 5 &&
1752 response
[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER
) {
1754 nkeys
= GET_32BIT(p
); p
+= 4;
1755 { char buf
[64]; sprintf(buf
, "Pageant has %d SSH1 keys", nkeys
);
1757 for (i
= 0; i
< nkeys
; i
++) {
1758 static struct RSAKey key
;
1759 static Bignum challenge
;
1760 static char *commentp
;
1761 static int commentlen
;
1763 { char buf
[64]; sprintf(buf
, "Trying Pageant key #%d", i
);
1766 p
+= ssh1_read_bignum(p
, &key
.exponent
);
1767 p
+= ssh1_read_bignum(p
, &key
.modulus
);
1768 commentlen
= GET_32BIT(p
); p
+= 4;
1769 commentp
= p
; p
+= commentlen
;
1770 send_packet(SSH1_CMSG_AUTH_RSA
,
1771 PKT_BIGNUM
, key
.modulus
, PKT_END
);
1773 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
1774 logevent("Key refused");
1777 logevent("Received RSA challenge");
1778 ssh1_read_bignum(pktin
.body
, &challenge
);
1780 char *agentreq
, *q
, *ret
;
1782 len
= 1 + 4; /* message type, bit count */
1783 len
+= ssh1_bignum_length(key
.exponent
);
1784 len
+= ssh1_bignum_length(key
.modulus
);
1785 len
+= ssh1_bignum_length(challenge
);
1786 len
+= 16; /* session id */
1787 len
+= 4; /* response format */
1788 agentreq
= smalloc(4 + len
);
1789 PUT_32BIT(agentreq
, len
);
1791 *q
++ = SSH1_AGENTC_RSA_CHALLENGE
;
1792 PUT_32BIT(q
, bignum_bitcount(key
.modulus
));
1794 q
+= ssh1_write_bignum(q
, key
.exponent
);
1795 q
+= ssh1_write_bignum(q
, key
.modulus
);
1796 q
+= ssh1_write_bignum(q
, challenge
);
1797 memcpy(q
, session_id
, 16); q
+= 16;
1798 PUT_32BIT(q
, 1); /* response format */
1799 agent_query(agentreq
, len
+4, &ret
, &retlen
);
1802 if (ret
[4] == SSH1_AGENT_RSA_RESPONSE
) {
1803 logevent("Sending Pageant's response");
1804 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
1805 PKT_DATA
, ret
+5, 16, PKT_END
);
1808 if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
1809 logevent("Pageant's response accepted");
1810 if (flags
& FLAG_VERBOSE
) {
1811 c_write_str("Authenticated using RSA key \"");
1812 c_write(commentp
, commentlen
);
1813 c_write_str("\" from agent\r\n");
1817 logevent("Pageant's response not accepted");
1819 logevent("Pageant failed to answer challenge");
1823 logevent("No reply received from Pageant");
1826 freebn(key
.exponent
);
1827 freebn(key
.modulus
);
1836 if (*cfg
.keyfile
&& !tried_publickey
)
1837 pwpkt_type
= SSH1_CMSG_AUTH_RSA
;
1839 if (pktin
.type
== SSH1_SMSG_FAILURE
&&
1841 (supported_auths_mask
& (1<<SSH1_AUTH_TIS
))) {
1842 pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
1843 logevent("Requested TIS authentication");
1844 send_packet(SSH1_CMSG_AUTH_TIS
, PKT_END
);
1846 if (pktin
.type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
1847 logevent("TIS authentication declined");
1848 if (flags
& FLAG_INTERACTIVE
)
1849 c_write_str("TIS authentication refused.\r\n");
1851 int challengelen
= ((pktin
.body
[0] << 24) |
1852 (pktin
.body
[1] << 16) |
1853 (pktin
.body
[2] << 8) |
1855 logevent("Received TIS challenge");
1856 if (challengelen
> sizeof(prompt
)-1)
1857 challengelen
= sizeof(prompt
)-1; /* prevent overrun */
1858 memcpy(prompt
, pktin
.body
+4, challengelen
);
1859 prompt
[challengelen
] = '\0';
1862 if (pktin
.type
== SSH1_SMSG_FAILURE
&&
1864 (supported_auths_mask
& (1<<SSH1_AUTH_CCARD
))) {
1865 pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
1866 logevent("Requested CryptoCard authentication");
1867 send_packet(SSH1_CMSG_AUTH_CCARD
, PKT_END
);
1869 if (pktin
.type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
1870 logevent("CryptoCard authentication declined");
1871 c_write_str("CryptoCard authentication refused.\r\n");
1873 int challengelen
= ((pktin
.body
[0] << 24) |
1874 (pktin
.body
[1] << 16) |
1875 (pktin
.body
[2] << 8) |
1877 logevent("Received CryptoCard challenge");
1878 if (challengelen
> sizeof(prompt
)-1)
1879 challengelen
= sizeof(prompt
)-1; /* prevent overrun */
1880 memcpy(prompt
, pktin
.body
+4, challengelen
);
1881 strncpy(prompt
+ challengelen
, "\r\nResponse : ",
1882 sizeof(prompt
)-challengelen
);
1883 prompt
[sizeof(prompt
)-1] = '\0';
1886 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
1887 sprintf(prompt
, "%.90s@%.90s's password: ",
1888 username
, savedhost
);
1890 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
1891 char *comment
= NULL
;
1892 if (flags
& FLAG_VERBOSE
)
1893 c_write_str("Trying public key authentication.\r\n");
1894 if (!rsakey_encrypted(cfg
.keyfile
, &comment
)) {
1895 if (flags
& FLAG_VERBOSE
)
1896 c_write_str("No passphrase required.\r\n");
1899 sprintf(prompt
, "Passphrase for key \"%.100s\": ", comment
);
1904 if (!ssh_get_line(prompt
, password
, sizeof(password
), TRUE
)) {
1906 * get_line failed to get a password (for example
1907 * because one was supplied on the command line
1908 * which has already failed to work). Terminate.
1910 logevent("No more passwords to try");
1911 ssh_state
= SSH_STATE_CLOSED
;
1915 c_write_str(prompt
);
1919 crWaitUntil(!ispkt
);
1920 while (inlen
--) switch (c
= *in
++) {
1937 if (((c
>= ' ' && c
<= '~') ||
1938 ((unsigned char)c
>= 160)) && pos
< sizeof(password
))
1939 password
[pos
++] = c
;
1943 c_write_str("\r\n");
1947 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
1949 * Try public key authentication with the specified
1952 static struct RSAKey pubkey
;
1953 static Bignum challenge
, response
;
1955 static unsigned char buffer
[32];
1957 tried_publickey
= 1;
1958 i
= loadrsakey(cfg
.keyfile
, &pubkey
, password
);
1960 c_write_str("Couldn't load public key from ");
1961 c_write_str(cfg
.keyfile
);
1962 c_write_str(".\r\n");
1963 continue; /* go and try password */
1966 c_write_str("Wrong passphrase.\r\n");
1967 tried_publickey
= 0;
1968 continue; /* try again */
1972 * Send a public key attempt.
1974 send_packet(SSH1_CMSG_AUTH_RSA
,
1975 PKT_BIGNUM
, pubkey
.modulus
, PKT_END
);
1978 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1979 c_write_str("Server refused our public key.\r\n");
1980 continue; /* go and try password */
1982 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
1983 bombout(("Bizarre response to offer of public key"));
1986 ssh1_read_bignum(pktin
.body
, &challenge
);
1987 response
= rsadecrypt(challenge
, &pubkey
);
1988 freebn(pubkey
.private_exponent
); /* burn the evidence */
1990 for (i
= 0; i
< 32; i
++) {
1991 buffer
[i
] = bignum_byte(response
, 31-i
);
1995 MD5Update(&md5c
, buffer
, 32);
1996 MD5Update(&md5c
, session_id
, 16);
1997 MD5Final(buffer
, &md5c
);
1999 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
2000 PKT_DATA
, buffer
, 16, PKT_END
);
2003 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2004 if (flags
& FLAG_VERBOSE
)
2005 c_write_str("Failed to authenticate with our public key.\r\n");
2006 continue; /* go and try password */
2007 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2008 bombout(("Bizarre response to RSA authentication response"));
2012 break; /* we're through! */
2014 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2016 * Defence against traffic analysis: we send a
2017 * whole bunch of packets containing strings of
2018 * different lengths. One of these strings is the
2019 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2020 * The others are all random data in
2021 * SSH1_MSG_IGNORE packets. This way a passive
2022 * listener can't tell which is the password, and
2023 * hence can't deduce the password length.
2025 * Anybody with a password length greater than 16
2026 * bytes is going to have enough entropy in their
2027 * password that a listener won't find it _that_
2028 * much help to know how long it is. So what we'll
2031 * - if password length < 16, we send 15 packets
2032 * containing string lengths 1 through 15
2034 * - otherwise, we let N be the nearest multiple
2035 * of 8 below the password length, and send 8
2036 * packets containing string lengths N through
2037 * N+7. This won't obscure the order of
2038 * magnitude of the password length, but it will
2039 * introduce a bit of extra uncertainty.
2041 * A few servers (the old 1.2.18 through 1.2.22)
2042 * can't deal with SSH1_MSG_IGNORE. For these
2043 * servers, we need an alternative defence. We make
2044 * use of the fact that the password is interpreted
2045 * as a C string: so we can append a NUL, then some
2048 if (ssh_remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
) {
2053 len
= strlen(password
);
2054 if (len
< sizeof(string
)) {
2056 strcpy(string
, password
);
2057 len
++; /* cover the zero byte */
2058 while (len
< sizeof(string
)) {
2059 string
[len
++] = (char)random_byte();
2064 send_packet(pwpkt_type
, PKT_INT
, len
,
2065 PKT_DATA
, s
, len
, PKT_END
);
2067 int bottom
, top
, pwlen
, i
;
2070 pwlen
= strlen(password
);
2072 bottom
= 0; /* zero length passwords are OK! :-) */
2075 bottom
= pwlen
&~ 7;
2079 assert(pwlen
>= bottom
&& pwlen
<= top
);
2081 randomstr
= smalloc(top
+1);
2083 for (i
= bottom
; i
<= top
; i
++) {
2085 defer_packet(pwpkt_type
, PKT_STR
, password
, PKT_END
);
2087 for (j
= 0; j
< i
; j
++) {
2089 randomstr
[j
] = random_byte();
2090 } while (randomstr
[j
] == '\0');
2092 randomstr
[i
] = '\0';
2093 defer_packet(SSH1_MSG_IGNORE
,
2094 PKT_STR
, randomstr
, PKT_END
);
2097 ssh_pkt_defersend();
2100 send_packet(pwpkt_type
, PKT_STR
, password
, PKT_END
);
2103 logevent("Sent password");
2104 memset(password
, 0, strlen(password
));
2106 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2107 if (flags
& FLAG_VERBOSE
)
2108 c_write_str("Access denied\r\n");
2109 logevent("Authentication refused");
2110 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
2111 logevent("Received disconnect request");
2112 ssh_state
= SSH_STATE_CLOSED
;
2114 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2115 bombout(("Strange packet received, type %d", pktin
.type
));
2120 logevent("Authentication successful");
2125 void sshfwd_close(struct ssh_channel
*c
) {
2126 if (c
&& !c
->closes
) {
2127 if (ssh_version
== 1) {
2128 send_packet(SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
, PKT_END
);
2130 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
2131 ssh2_pkt_adduint32(c
->remoteid
);
2135 if (c
->type
== CHAN_X11
) {
2137 logevent("X11 connection terminated");
2142 void sshfwd_write(struct ssh_channel
*c
, char *buf
, int len
) {
2143 if (ssh_version
== 1) {
2144 send_packet(SSH1_MSG_CHANNEL_DATA
,
2145 PKT_INT
, c
->remoteid
,
2150 ssh2_add_channel_data(c
, buf
, len
);
2155 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
) {
2160 while (!do_ssh1_login(in
, inlen
, ispkt
)) {
2163 if (ssh_state
== SSH_STATE_CLOSED
)
2166 if (cfg
.agentfwd
&& agent_exists()) {
2167 logevent("Requesting agent forwarding");
2168 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
2169 do { crReturnV
; } while (!ispkt
);
2170 if (pktin
.type
!= SSH1_SMSG_SUCCESS
&& pktin
.type
!= SSH1_SMSG_FAILURE
) {
2171 bombout(("Protocol confusion"));
2173 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2174 logevent("Agent forwarding refused");
2176 logevent("Agent forwarding enabled");
2177 ssh_agentfwd_enabled
= TRUE
;
2181 if (cfg
.x11_forward
) {
2182 char proto
[20], data
[64];
2183 logevent("Requesting X11 forwarding");
2184 x11_invent_auth(proto
, sizeof(proto
), data
, sizeof(data
));
2185 if (ssh1_local_protoflags
& SSH1_PROTOFLAG_SCREEN_NUMBER
) {
2186 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING
,
2187 PKT_STR
, proto
, PKT_STR
, data
,
2191 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING
,
2192 PKT_STR
, proto
, PKT_STR
, data
,
2195 do { crReturnV
; } while (!ispkt
);
2196 if (pktin
.type
!= SSH1_SMSG_SUCCESS
&& pktin
.type
!= SSH1_SMSG_FAILURE
) {
2197 bombout(("Protocol confusion"));
2199 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2200 logevent("X11 forwarding refused");
2202 logevent("X11 forwarding enabled");
2203 ssh_X11_fwd_enabled
= TRUE
;
2208 send_packet(SSH1_CMSG_REQUEST_PTY
,
2209 PKT_STR
, cfg
.termtype
,
2210 PKT_INT
, rows
, PKT_INT
, cols
,
2211 PKT_INT
, 0, PKT_INT
, 0,
2214 ssh_state
= SSH_STATE_INTERMED
;
2215 do { crReturnV
; } while (!ispkt
);
2216 if (pktin
.type
!= SSH1_SMSG_SUCCESS
&& pktin
.type
!= SSH1_SMSG_FAILURE
) {
2217 bombout(("Protocol confusion"));
2219 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2220 c_write_str("Server refused to allocate pty\r\n");
2221 ssh_editing
= ssh_echoing
= 1;
2223 logevent("Allocated pty");
2225 ssh_editing
= ssh_echoing
= 1;
2228 if (cfg
.compression
) {
2229 send_packet(SSH1_CMSG_REQUEST_COMPRESSION
, PKT_INT
, 6, PKT_END
);
2230 do { crReturnV
; } while (!ispkt
);
2231 if (pktin
.type
!= SSH1_SMSG_SUCCESS
&& pktin
.type
!= SSH1_SMSG_FAILURE
) {
2232 bombout(("Protocol confusion"));
2234 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2235 c_write_str("Server refused to compress\r\n");
2237 logevent("Started compression");
2238 ssh1_compressing
= TRUE
;
2239 zlib_compress_init();
2240 zlib_decompress_init();
2243 if (*cfg
.remote_cmd_ptr
)
2244 send_packet(SSH1_CMSG_EXEC_CMD
, PKT_STR
, cfg
.remote_cmd_ptr
, PKT_END
);
2246 send_packet(SSH1_CMSG_EXEC_SHELL
, PKT_END
);
2247 logevent("Started session");
2249 ssh_state
= SSH_STATE_SESSION
;
2253 ssh_special(TS_EOF
);
2255 ldisc_send(NULL
, 0); /* cause ldisc to notice changes */
2257 ssh_channels
= newtree234(ssh_channelcmp
);
2261 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
2262 pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
2263 long len
= GET_32BIT(pktin
.body
);
2264 from_backend(pktin
.type
== SSH1_SMSG_STDERR_DATA
,
2266 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
2267 ssh_state
= SSH_STATE_CLOSED
;
2268 logevent("Received disconnect request");
2270 } else if (pktin
.type
== SSH1_SMSG_X11_OPEN
) {
2271 /* Remote side is trying to open a channel to talk to our
2272 * X-Server. Give them back a local channel number. */
2273 struct ssh_channel
*c
;
2275 logevent("Received X11 connect request");
2276 /* Refuse if X11 forwarding is disabled. */
2277 if (!ssh_X11_fwd_enabled
) {
2278 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2279 PKT_INT
, GET_32BIT(pktin
.body
),
2281 logevent("Rejected X11 connect request");
2283 c
= smalloc(sizeof(struct ssh_channel
));
2285 if ( x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
) != NULL
) {
2286 logevent("opening X11 forward connection failed");
2288 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2289 PKT_INT
, GET_32BIT(pktin
.body
),
2292 logevent("opening X11 forward connection succeeded");
2293 c
->remoteid
= GET_32BIT(pktin
.body
);
2294 c
->localid
= alloc_channel_id();
2296 c
->type
= CHAN_X11
; /* identify channel type */
2297 add234(ssh_channels
, c
);
2298 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
2299 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
2301 logevent("Opened X11 forward channel");
2304 } else if (pktin
.type
== SSH1_SMSG_AGENT_OPEN
) {
2305 /* Remote side is trying to open a channel to talk to our
2306 * agent. Give them back a local channel number. */
2307 struct ssh_channel
*c
;
2309 /* Refuse if agent forwarding is disabled. */
2310 if (!ssh_agentfwd_enabled
) {
2311 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2312 PKT_INT
, GET_32BIT(pktin
.body
),
2315 c
= smalloc(sizeof(struct ssh_channel
));
2316 c
->remoteid
= GET_32BIT(pktin
.body
);
2317 c
->localid
= alloc_channel_id();
2319 c
->type
= CHAN_AGENT
; /* identify channel type */
2320 c
->u
.a
.lensofar
= 0;
2321 add234(ssh_channels
, c
);
2322 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
2323 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
2326 } else if (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE
||
2327 pktin
.type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
) {
2328 /* Remote side closes a channel. */
2329 unsigned i
= GET_32BIT(pktin
.body
);
2330 struct ssh_channel
*c
;
2331 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
2334 closetype
= (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
1 : 2);
2335 if (!(c
->closes
& closetype
))
2336 send_packet(pktin
.type
, PKT_INT
, c
->remoteid
, PKT_END
);
2337 if ((c
->closes
== 0) && (c
->type
== CHAN_X11
)) {
2338 logevent("X11 connection closed");
2339 assert(c
->u
.x11
.s
!= NULL
);
2340 x11_close(c
->u
.x11
.s
);
2343 c
->closes
|= closetype
;
2344 if (c
->closes
== 3) {
2345 del234(ssh_channels
, c
);
2349 } else if (pktin
.type
== SSH1_MSG_CHANNEL_DATA
) {
2350 /* Data sent down one of our channels. */
2351 int i
= GET_32BIT(pktin
.body
);
2352 int len
= GET_32BIT(pktin
.body
+4);
2353 unsigned char *p
= pktin
.body
+8;
2354 struct ssh_channel
*c
;
2355 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
2359 x11_send(c
->u
.x11
.s
, p
, len
);
2362 /* Data for an agent message. Buffer it. */
2364 if (c
->u
.a
.lensofar
< 4) {
2365 int l
= min(4 - c
->u
.a
.lensofar
, len
);
2366 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
, l
);
2367 p
+= l
; len
-= l
; c
->u
.a
.lensofar
+= l
;
2369 if (c
->u
.a
.lensofar
== 4) {
2370 c
->u
.a
.totallen
= 4 + GET_32BIT(c
->u
.a
.msglen
);
2371 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
2372 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
2374 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
2375 int l
= min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
, len
);
2376 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
, l
);
2377 p
+= l
; len
-= l
; c
->u
.a
.lensofar
+= l
;
2379 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
2380 void *reply
, *sentreply
;
2382 agent_query(c
->u
.a
.message
, c
->u
.a
.totallen
,
2387 /* Fake SSH_AGENT_FAILURE. */
2388 sentreply
= "\0\0\0\1\5";
2391 send_packet(SSH1_MSG_CHANNEL_DATA
,
2392 PKT_INT
, c
->remoteid
,
2394 PKT_DATA
, sentreply
, replylen
,
2398 sfree(c
->u
.a
.message
);
2399 c
->u
.a
.lensofar
= 0;
2405 } else if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
2406 /* may be from EXEC_SHELL on some servers */
2407 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2408 /* may be from EXEC_SHELL on some servers
2409 * if no pty is available or in other odd cases. Ignore */
2410 } else if (pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
2411 send_packet(SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
2413 bombout(("Strange packet received: type %d", pktin
.type
));
2418 int len
= min(inlen
, 512);
2419 send_packet(SSH1_CMSG_STDIN_DATA
,
2420 PKT_INT
, len
, PKT_DATA
, in
, len
, PKT_END
);
2431 * Utility routine for decoding comma-separated strings in KEXINIT.
2433 static int in_commasep_string(char *needle
, char *haystack
, int haylen
) {
2434 int needlen
= strlen(needle
);
2437 * Is it at the start of the string?
2439 if (haylen
>= needlen
&& /* haystack is long enough */
2440 !memcmp(needle
, haystack
, needlen
) && /* initial match */
2441 (haylen
== needlen
|| haystack
[needlen
] == ',')
2442 /* either , or EOS follows */
2446 * If not, search for the next comma and resume after that.
2447 * If no comma found, terminate.
2449 while (haylen
> 0 && *haystack
!= ',')
2450 haylen
--, haystack
++;
2453 haylen
--, haystack
++; /* skip over comma itself */
2458 * SSH2 key creation method.
2460 static void ssh2_mkkey(Bignum K
, char *H
, char *sessid
, char chr
, char *keyspace
) {
2462 /* First 20 bytes. */
2465 SHA_Bytes(&s
, H
, 20);
2466 SHA_Bytes(&s
, &chr
, 1);
2467 SHA_Bytes(&s
, sessid
, 20);
2468 SHA_Final(&s
, keyspace
);
2469 /* Next 20 bytes. */
2472 SHA_Bytes(&s
, H
, 20);
2473 SHA_Bytes(&s
, keyspace
, 20);
2474 SHA_Final(&s
, keyspace
+20);
2478 * Handle the SSH2 transport layer.
2480 static int do_ssh2_transport(unsigned char *in
, int inlen
, int ispkt
)
2482 static int i
, j
, len
, nbits
, pbits
;
2484 static Bignum p
, g
, e
, f
, K
;
2485 static int kex_init_value
, kex_reply_value
;
2486 static const struct ssh_mac
**maclist
;
2488 static const struct ssh2_cipher
*cscipher_tobe
= NULL
;
2489 static const struct ssh2_cipher
*sccipher_tobe
= NULL
;
2490 static const struct ssh_mac
*csmac_tobe
= NULL
;
2491 static const struct ssh_mac
*scmac_tobe
= NULL
;
2492 static const struct ssh_compress
*cscomp_tobe
= NULL
;
2493 static const struct ssh_compress
*sccomp_tobe
= NULL
;
2494 static char *hostkeydata
, *sigdata
, *keystr
, *fingerprint
;
2495 static int hostkeylen
, siglen
;
2496 static void *hkey
; /* actual host key */
2497 static unsigned char exchange_hash
[20];
2498 static unsigned char keyspace
[40];
2499 static const struct ssh2_ciphers
*preferred_cipher
;
2500 static const struct ssh_compress
*preferred_comp
;
2501 static int first_kex
;
2508 * Set up the preferred cipher and compression.
2510 if (cfg
.cipher
== CIPHER_BLOWFISH
) {
2511 preferred_cipher
= &ssh2_blowfish
;
2512 } else if (cfg
.cipher
== CIPHER_DES
) {
2513 logevent("Single DES not supported in SSH2; using 3DES");
2514 preferred_cipher
= &ssh2_3des
;
2515 } else if (cfg
.cipher
== CIPHER_3DES
) {
2516 preferred_cipher
= &ssh2_3des
;
2517 } else if (cfg
.cipher
== CIPHER_AES
) {
2518 preferred_cipher
= &ssh2_aes
;
2520 /* Shouldn't happen, but we do want to initialise to _something_. */
2521 preferred_cipher
= &ssh2_3des
;
2523 if (cfg
.compression
)
2524 preferred_comp
= &ssh_zlib
;
2526 preferred_comp
= &ssh_comp_none
;
2529 * Be prepared to work around the buggy MAC problem.
2531 if (cfg
.buggymac
|| (ssh_remote_bugs
& BUG_SSH2_HMAC
))
2532 maclist
= buggymacs
, nmacs
= lenof(buggymacs
);
2534 maclist
= macs
, nmacs
= lenof(macs
);
2538 * Construct and send our key exchange packet.
2540 ssh2_pkt_init(SSH2_MSG_KEXINIT
);
2541 for (i
= 0; i
< 16; i
++)
2542 ssh2_pkt_addbyte((unsigned char)random_byte());
2543 /* List key exchange algorithms. */
2544 ssh2_pkt_addstring_start();
2545 for (i
= 0; i
< lenof(kex_algs
); i
++) {
2546 ssh2_pkt_addstring_str(kex_algs
[i
]->name
);
2547 if (i
< lenof(kex_algs
)-1)
2548 ssh2_pkt_addstring_str(",");
2550 /* List server host key algorithms. */
2551 ssh2_pkt_addstring_start();
2552 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
2553 ssh2_pkt_addstring_str(hostkey_algs
[i
]->name
);
2554 if (i
< lenof(hostkey_algs
)-1)
2555 ssh2_pkt_addstring_str(",");
2557 /* List client->server encryption algorithms. */
2558 ssh2_pkt_addstring_start();
2559 for (i
= 0; i
< lenof(ciphers
)+1; i
++) {
2560 const struct ssh2_ciphers
*c
= i
==0 ? preferred_cipher
: ciphers
[i
-1];
2561 for (j
= 0; j
< c
->nciphers
; j
++) {
2562 ssh2_pkt_addstring_str(c
->list
[j
]->name
);
2563 if (i
< lenof(ciphers
) || j
< c
->nciphers
-1)
2564 ssh2_pkt_addstring_str(",");
2567 /* List server->client encryption algorithms. */
2568 ssh2_pkt_addstring_start();
2569 for (i
= 0; i
< lenof(ciphers
)+1; i
++) {
2570 const struct ssh2_ciphers
*c
= i
==0 ? preferred_cipher
: ciphers
[i
-1];
2571 for (j
= 0; j
< c
->nciphers
; j
++) {
2572 ssh2_pkt_addstring_str(c
->list
[j
]->name
);
2573 if (i
< lenof(ciphers
) || j
< c
->nciphers
-1)
2574 ssh2_pkt_addstring_str(",");
2577 /* List client->server MAC algorithms. */
2578 ssh2_pkt_addstring_start();
2579 for (i
= 0; i
< nmacs
; i
++) {
2580 ssh2_pkt_addstring_str(maclist
[i
]->name
);
2582 ssh2_pkt_addstring_str(",");
2584 /* List server->client MAC algorithms. */
2585 ssh2_pkt_addstring_start();
2586 for (i
= 0; i
< nmacs
; i
++) {
2587 ssh2_pkt_addstring_str(maclist
[i
]->name
);
2589 ssh2_pkt_addstring_str(",");
2591 /* List client->server compression algorithms. */
2592 ssh2_pkt_addstring_start();
2593 for (i
= 0; i
< lenof(compressions
)+1; i
++) {
2594 const struct ssh_compress
*c
= i
==0 ? preferred_comp
: compressions
[i
-1];
2595 ssh2_pkt_addstring_str(c
->name
);
2596 if (i
< lenof(compressions
))
2597 ssh2_pkt_addstring_str(",");
2599 /* List server->client compression algorithms. */
2600 ssh2_pkt_addstring_start();
2601 for (i
= 0; i
< lenof(compressions
)+1; i
++) {
2602 const struct ssh_compress
*c
= i
==0 ? preferred_comp
: compressions
[i
-1];
2603 ssh2_pkt_addstring_str(c
->name
);
2604 if (i
< lenof(compressions
))
2605 ssh2_pkt_addstring_str(",");
2607 /* List client->server languages. Empty list. */
2608 ssh2_pkt_addstring_start();
2609 /* List server->client languages. Empty list. */
2610 ssh2_pkt_addstring_start();
2611 /* First KEX packet does _not_ follow, because we're not that brave. */
2612 ssh2_pkt_addbool(FALSE
);
2614 ssh2_pkt_adduint32(0);
2616 exhash
= exhashbase
;
2617 sha_string(&exhash
, pktout
.data
+5, pktout
.length
-5);
2621 if (!ispkt
) crWaitUntil(ispkt
);
2622 sha_string(&exhash
, pktin
.data
+5, pktin
.length
-5);
2625 * Now examine the other side's KEXINIT to see what we're up
2628 if (pktin
.type
!= SSH2_MSG_KEXINIT
) {
2629 bombout(("expected key exchange packet from server"));
2632 kex
= NULL
; hostkey
= NULL
; cscipher_tobe
= NULL
; sccipher_tobe
= NULL
;
2633 csmac_tobe
= NULL
; scmac_tobe
= NULL
; cscomp_tobe
= NULL
; sccomp_tobe
= NULL
;
2634 pktin
.savedpos
+= 16; /* skip garbage cookie */
2635 ssh2_pkt_getstring(&str
, &len
); /* key exchange algorithms */
2636 for (i
= 0; i
< lenof(kex_algs
); i
++) {
2637 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
2642 ssh2_pkt_getstring(&str
, &len
); /* host key algorithms */
2643 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
2644 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
2645 hostkey
= hostkey_algs
[i
];
2649 ssh2_pkt_getstring(&str
, &len
); /* client->server cipher */
2650 for (i
= 0; i
< lenof(ciphers
)+1; i
++) {
2651 const struct ssh2_ciphers
*c
= i
==0 ? preferred_cipher
: ciphers
[i
-1];
2652 for (j
= 0; j
< c
->nciphers
; j
++) {
2653 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
2654 cscipher_tobe
= c
->list
[j
];
2661 ssh2_pkt_getstring(&str
, &len
); /* server->client cipher */
2662 for (i
= 0; i
< lenof(ciphers
)+1; i
++) {
2663 const struct ssh2_ciphers
*c
= i
==0 ? preferred_cipher
: ciphers
[i
-1];
2664 for (j
= 0; j
< c
->nciphers
; j
++) {
2665 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
2666 sccipher_tobe
= c
->list
[j
];
2673 ssh2_pkt_getstring(&str
, &len
); /* client->server mac */
2674 for (i
= 0; i
< nmacs
; i
++) {
2675 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
2676 csmac_tobe
= maclist
[i
];
2680 ssh2_pkt_getstring(&str
, &len
); /* server->client mac */
2681 for (i
= 0; i
< nmacs
; i
++) {
2682 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
2683 scmac_tobe
= maclist
[i
];
2687 ssh2_pkt_getstring(&str
, &len
); /* client->server compression */
2688 for (i
= 0; i
< lenof(compressions
)+1; i
++) {
2689 const struct ssh_compress
*c
= i
==0 ? preferred_comp
: compressions
[i
-1];
2690 if (in_commasep_string(c
->name
, str
, len
)) {
2695 ssh2_pkt_getstring(&str
, &len
); /* server->client compression */
2696 for (i
= 0; i
< lenof(compressions
)+1; i
++) {
2697 const struct ssh_compress
*c
= i
==0 ? preferred_comp
: compressions
[i
-1];
2698 if (in_commasep_string(c
->name
, str
, len
)) {
2705 * Work out the number of bits of key we will need from the key
2706 * exchange. We start with the maximum key length of either
2712 csbits
= cscipher_tobe
->keylen
;
2713 scbits
= sccipher_tobe
->keylen
;
2714 nbits
= (csbits
> scbits ? csbits
: scbits
);
2716 /* The keys only have 160-bit entropy, since they're based on
2717 * a SHA-1 hash. So cap the key size at 160 bits. */
2718 if (nbits
> 160) nbits
= 160;
2721 * If we're doing Diffie-Hellman group exchange, start by
2722 * requesting a group.
2724 if (kex
== &ssh_diffiehellman_gex
) {
2725 logevent("Doing Diffie-Hellman group exchange");
2727 * Work out how big a DH group we will need to allow that
2730 pbits
= 512 << ((nbits
-1) / 64);
2731 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST
);
2732 ssh2_pkt_adduint32(pbits
);
2736 if (pktin
.type
!= SSH2_MSG_KEX_DH_GEX_GROUP
) {
2737 bombout(("expected key exchange group packet from server"));
2740 p
= ssh2_pkt_getmp();
2741 g
= ssh2_pkt_getmp();
2742 dh_setup_group(p
, g
);
2743 kex_init_value
= SSH2_MSG_KEX_DH_GEX_INIT
;
2744 kex_reply_value
= SSH2_MSG_KEX_DH_GEX_REPLY
;
2747 kex_init_value
= SSH2_MSG_KEXDH_INIT
;
2748 kex_reply_value
= SSH2_MSG_KEXDH_REPLY
;
2751 logevent("Doing Diffie-Hellman key exchange");
2753 * Now generate and send e for Diffie-Hellman.
2755 e
= dh_create_e(nbits
*2);
2756 ssh2_pkt_init(kex_init_value
);
2761 if (pktin
.type
!= kex_reply_value
) {
2762 bombout(("expected key exchange reply packet from server"));
2765 ssh2_pkt_getstring(&hostkeydata
, &hostkeylen
);
2766 f
= ssh2_pkt_getmp();
2767 ssh2_pkt_getstring(&sigdata
, &siglen
);
2771 sha_string(&exhash
, hostkeydata
, hostkeylen
);
2772 if (kex
== &ssh_diffiehellman_gex
) {
2773 sha_uint32(&exhash
, pbits
);
2774 sha_mpint(&exhash
, p
);
2775 sha_mpint(&exhash
, g
);
2777 sha_mpint(&exhash
, e
);
2778 sha_mpint(&exhash
, f
);
2779 sha_mpint(&exhash
, K
);
2780 SHA_Final(&exhash
, exchange_hash
);
2785 debug(("Exchange hash is:\r\n"));
2786 for (i
= 0; i
< 20; i
++)
2787 debug((" %02x", exchange_hash
[i
]));
2791 hkey
= hostkey
->newkey(hostkeydata
, hostkeylen
);
2792 if (!hostkey
->verifysig(hkey
, sigdata
, siglen
, exchange_hash
, 20)) {
2793 bombout(("Server failed host key check"));
2798 * Expect SSH2_MSG_NEWKEYS from server.
2801 if (pktin
.type
!= SSH2_MSG_NEWKEYS
) {
2802 bombout(("expected new-keys packet from server"));
2807 * Authenticate remote host: verify host key. (We've already
2808 * checked the signature of the exchange hash.)
2810 keystr
= hostkey
->fmtkey(hkey
);
2811 fingerprint
= hostkey
->fingerprint(hkey
);
2812 verify_ssh_host_key(savedhost
, savedport
, hostkey
->keytype
,
2813 keystr
, fingerprint
);
2814 if (first_kex
) { /* don't bother logging this in rekeys */
2815 logevent("Host key fingerprint is:");
2816 logevent(fingerprint
);
2820 hostkey
->freekey(hkey
);
2823 * Send SSH2_MSG_NEWKEYS.
2825 ssh2_pkt_init(SSH2_MSG_NEWKEYS
);
2829 * Create and initialise session keys.
2831 cscipher
= cscipher_tobe
;
2832 sccipher
= sccipher_tobe
;
2835 cscomp
= cscomp_tobe
;
2836 sccomp
= sccomp_tobe
;
2837 cscomp
->compress_init();
2838 sccomp
->decompress_init();
2840 * Set IVs after keys. Here we use the exchange hash from the
2841 * _first_ key exchange.
2844 memcpy(ssh2_session_id
, exchange_hash
, sizeof(exchange_hash
));
2845 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'C', keyspace
);
2846 cscipher
->setcskey(keyspace
);
2847 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'D', keyspace
);
2848 sccipher
->setsckey(keyspace
);
2849 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'A', keyspace
);
2850 cscipher
->setcsiv(keyspace
);
2851 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'B', keyspace
);
2852 sccipher
->setsciv(keyspace
);
2853 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'E', keyspace
);
2854 csmac
->setcskey(keyspace
);
2855 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'F', keyspace
);
2856 scmac
->setsckey(keyspace
);
2859 * If this is the first key exchange phase, we must pass the
2860 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
2861 * wants to see it but because it will need time to initialise
2862 * itself before it sees an actual packet. In subsequent key
2863 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
2864 * it would only confuse the layer above.
2872 * Now we're encrypting. Begin returning 1 to the protocol main
2873 * function so that other things can run on top of the
2874 * transport. If we ever see a KEXINIT, we must go back to the
2877 while (!(ispkt
&& pktin
.type
== SSH2_MSG_KEXINIT
)) {
2880 logevent("Server initiated key re-exchange");
2881 goto begin_key_exchange
;
2887 * Add data to an SSH2 channel output buffer.
2889 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
, int len
) {
2890 if (c
->v2
.outbufsize
<
2891 c
->v2
.outbuflen
+ len
) {
2893 c
->v2
.outbuflen
+ len
+ 1024;
2894 c
->v2
.outbuffer
= srealloc(c
->v2
.outbuffer
,
2897 memcpy(c
->v2
.outbuffer
+ c
->v2
.outbuflen
,
2899 c
->v2
.outbuflen
+= len
;
2903 * Attempt to send data on an SSH2 channel.
2905 static void ssh2_try_send(struct ssh_channel
*c
) {
2906 while (c
->v2
.remwindow
> 0 &&
2907 c
->v2
.outbuflen
> 0) {
2908 unsigned len
= c
->v2
.remwindow
;
2909 if (len
> c
->v2
.outbuflen
)
2910 len
= c
->v2
.outbuflen
;
2911 if (len
> c
->v2
.remmaxpkt
)
2912 len
= c
->v2
.remmaxpkt
;
2913 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA
);
2914 ssh2_pkt_adduint32(c
->remoteid
);
2915 ssh2_pkt_addstring_start();
2916 ssh2_pkt_addstring_data(c
->v2
.outbuffer
, len
);
2918 c
->v2
.outbuflen
-= len
;
2919 memmove(c
->v2
.outbuffer
, c
->v2
.outbuffer
+len
,
2921 c
->v2
.remwindow
-= len
;
2926 * Handle the SSH2 userauth and connection layers.
2928 static void do_ssh2_authconn(unsigned char *in
, int inlen
, int ispkt
)
2930 static unsigned long remote_winsize
;
2931 static unsigned long remote_maxpkt
;
2933 AUTH_INVALID
, AUTH_PUBLICKEY_AGENT
, AUTH_PUBLICKEY_FILE
, AUTH_PASSWORD
2937 AUTH_TYPE_PUBLICKEY
,
2938 AUTH_TYPE_PUBLICKEY_OFFER_LOUD
,
2939 AUTH_TYPE_PUBLICKEY_OFFER_QUIET
,
2942 static int gotit
, need_pw
, can_pubkey
, can_passwd
;
2943 static int tried_pubkey_config
, tried_agent
;
2944 static int we_are_in
;
2945 static char username
[100];
2946 static char pwprompt
[200];
2947 static char password
[100];
2952 * Request userauth protocol, and await a response to it.
2954 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
2955 ssh2_pkt_addstring("ssh-userauth");
2957 crWaitUntilV(ispkt
);
2958 if (pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
) {
2959 bombout(("Server refused user authentication protocol"));
2964 * We repeat this whole loop, including the username prompt,
2965 * until we manage a successful authentication. If the user
2966 * types the wrong _password_, they are sent back to the
2967 * beginning to try another username. (If they specify a
2968 * username in the config, they are never asked, even if they
2969 * do give a wrong password.)
2971 * I think this best serves the needs of
2973 * - the people who have no configuration, no keys, and just
2974 * want to try repeated (username,password) pairs until they
2975 * type both correctly
2977 * - people who have keys and configuration but occasionally
2978 * need to fall back to passwords
2980 * - people with a key held in Pageant, who might not have
2981 * logged in to a particular machine before; so they want to
2982 * type a username, and then _either_ their key will be
2983 * accepted, _or_ they will type a password. If they mistype
2984 * the username they will want to be able to get back and
2995 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
2997 if (!ssh_get_line("login as: ",
2998 username
, sizeof(username
), FALSE
)) {
3000 * get_line failed to get a username.
3003 logevent("No username provided. Abandoning session.");
3004 ssh_state
= SSH_STATE_CLOSED
;
3008 c_write_str("login as: ");
3011 crWaitUntilV(!ispkt
);
3012 while (inlen
--) switch (c
= *in
++) {
3019 c_write_str("\b \b");
3025 c_write_str("\b \b");
3034 if (((c
>= ' ' && c
<= '~') ||
3035 ((unsigned char)c
>= 160)) && pos
< 40) {
3036 username
[pos
++] = c
;
3043 c_write_str("\r\n");
3044 username
[strcspn(username
, "\n\r")] = '\0';
3047 strncpy(username
, cfg
.username
, 99);
3048 username
[99] = '\0';
3049 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
3050 sprintf(stuff
, "Using username \"%s\".\r\n", username
);
3056 * Send an authentication request using method "none": (a)
3057 * just in case it succeeds, and (b) so that we know what
3058 * authentication methods we can usefully try next.
3060 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
3061 ssh2_pkt_addstring(username
);
3062 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3063 ssh2_pkt_addstring("none"); /* method */
3065 type
= AUTH_TYPE_NONE
;
3069 tried_pubkey_config
= FALSE
;
3070 tried_agent
= FALSE
;
3074 * Wait for the result of the last authentication request.
3077 crWaitUntilV(ispkt
);
3078 while (pktin
.type
== SSH2_MSG_USERAUTH_BANNER
) {
3082 * Don't show the banner if we're operating in
3083 * non-verbose non-interactive mode. (It's probably
3084 * a script, which means nobody will read the
3085 * banner _anyway_, and moreover the printing of
3086 * the banner will screw up processing on the
3087 * output of (say) plink.)
3089 if (flags
& (FLAG_VERBOSE
| FLAG_INTERACTIVE
)) {
3090 ssh2_pkt_getstring(&banner
, &size
);
3092 c_write_untrusted(banner
, size
);
3094 crWaitUntilV(ispkt
);
3096 if (pktin
.type
== SSH2_MSG_USERAUTH_SUCCESS
) {
3097 logevent("Access granted");
3102 if (pktin
.type
!= SSH2_MSG_USERAUTH_FAILURE
) {
3103 bombout(("Strange packet received during authentication: type %d",
3111 * OK, we're now sitting on a USERAUTH_FAILURE message, so
3112 * we can look at the string in it and know what we can
3113 * helpfully try next.
3118 ssh2_pkt_getstring(&methods
, &methlen
);
3119 if (!ssh2_pkt_getbool()) {
3121 * We have received an unequivocal Access
3122 * Denied. This can translate to a variety of
3125 * - if we'd just tried "none" authentication,
3126 * it's not worth printing anything at all
3128 * - if we'd just tried a public key _offer_,
3129 * the message should be "Server refused our
3130 * key" (or no message at all if the key
3131 * came from Pageant)
3133 * - if we'd just tried anything else, the
3134 * message really should be "Access denied".
3136 * Additionally, if we'd just tried password
3137 * authentication, we should break out of this
3138 * whole loop so as to go back to the username
3141 if (type
== AUTH_TYPE_NONE
) {
3143 } else if (type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
||
3144 type
== AUTH_TYPE_PUBLICKEY_OFFER_QUIET
) {
3145 if (type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
)
3146 c_write_str("Server refused our key\r\n");
3147 logevent("Server refused public key");
3149 c_write_str("Access denied\r\n");
3150 logevent("Access denied");
3151 if (type
== AUTH_TYPE_PASSWORD
) {
3157 c_write_str("Further authentication required\r\n");
3158 logevent("Further authentication required");
3161 can_pubkey
= in_commasep_string("publickey", methods
, methlen
);
3162 can_passwd
= in_commasep_string("password", methods
, methlen
);
3167 if (!method
&& can_pubkey
&& agent_exists() && !tried_agent
) {
3169 * Attempt public-key authentication using Pageant.
3171 static unsigned char request
[5], *response
, *p
;
3172 static int responselen
;
3173 static int i
, nkeys
;
3174 static int authed
= FALSE
;
3179 logevent("Pageant is running. Requesting keys.");
3181 /* Request the keys held by the agent. */
3182 PUT_32BIT(request
, 1);
3183 request
[4] = SSH2_AGENTC_REQUEST_IDENTITIES
;
3184 agent_query(request
, 5, &r
, &responselen
);
3185 response
= (unsigned char *)r
;
3186 if (response
&& responselen
>= 5 &&
3187 response
[4] == SSH2_AGENT_IDENTITIES_ANSWER
) {
3189 nkeys
= GET_32BIT(p
); p
+= 4;
3190 { char buf
[64]; sprintf(buf
, "Pageant has %d SSH2 keys", nkeys
);
3192 for (i
= 0; i
< nkeys
; i
++) {
3193 static char *pkblob
, *alg
, *commentp
;
3194 static int pklen
, alglen
, commentlen
;
3195 static int siglen
, retlen
, len
;
3196 static char *q
, *agentreq
, *ret
;
3198 { char buf
[64]; sprintf(buf
, "Trying Pageant key #%d", i
);
3200 pklen
= GET_32BIT(p
); p
+= 4;
3201 pkblob
= p
; p
+= pklen
;
3202 alglen
= GET_32BIT(pkblob
);
3204 commentlen
= GET_32BIT(p
); p
+= 4;
3205 commentp
= p
; p
+= commentlen
;
3206 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
3207 ssh2_pkt_addstring(username
);
3208 ssh2_pkt_addstring("ssh-connection");/* service requested */
3209 ssh2_pkt_addstring("publickey");/* method */
3210 ssh2_pkt_addbool(FALSE
); /* no signature included */
3211 ssh2_pkt_addstring_start();
3212 ssh2_pkt_addstring_data(alg
, alglen
);
3213 ssh2_pkt_addstring_start();
3214 ssh2_pkt_addstring_data(pkblob
, pklen
);
3217 crWaitUntilV(ispkt
);
3218 if (pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
3219 logevent("Key refused");
3223 if (flags
& FLAG_VERBOSE
) {
3224 c_write_str("Authenticating with public key \"");
3225 c_write(commentp
, commentlen
);
3226 c_write_str("\" from agent\r\n");
3230 * Server is willing to accept the key.
3231 * Construct a SIGN_REQUEST.
3233 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
3234 ssh2_pkt_addstring(username
);
3235 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3236 ssh2_pkt_addstring("publickey"); /* method */
3237 ssh2_pkt_addbool(TRUE
);
3238 ssh2_pkt_addstring_start();
3239 ssh2_pkt_addstring_data(alg
, alglen
);
3240 ssh2_pkt_addstring_start();
3241 ssh2_pkt_addstring_data(pkblob
, pklen
);
3243 siglen
= pktout
.length
- 5 + 4 + 20;
3244 len
= 1; /* message type */
3245 len
+= 4 + pklen
; /* key blob */
3246 len
+= 4 + siglen
; /* data to sign */
3247 len
+= 4; /* flags */
3248 agentreq
= smalloc(4 + len
);
3249 PUT_32BIT(agentreq
, len
);
3251 *q
++ = SSH2_AGENTC_SIGN_REQUEST
;
3252 PUT_32BIT(q
, pklen
); q
+= 4;
3253 memcpy(q
, pkblob
, pklen
); q
+= pklen
;
3254 PUT_32BIT(q
, siglen
); q
+= 4;
3255 /* Now the data to be signed... */
3256 PUT_32BIT(q
, 20); q
+= 4;
3257 memcpy(q
, ssh2_session_id
, 20); q
+= 20;
3258 memcpy(q
, pktout
.data
+5, pktout
.length
-5);
3259 q
+= pktout
.length
-5;
3260 /* And finally the (zero) flags word. */
3262 agent_query(agentreq
, len
+4, &ret
, &retlen
);
3265 if (ret
[4] == SSH2_AGENT_SIGN_RESPONSE
) {
3266 logevent("Sending Pageant's response");
3267 ssh2_pkt_addstring_start();
3268 ssh2_pkt_addstring_data(ret
+9, GET_32BIT(ret
+5));
3273 logevent("Pageant failed to answer challenge");
3283 if (!method
&& can_pubkey
&& *cfg
.keyfile
&& !tried_pubkey_config
) {
3284 unsigned char *pub_blob
;
3285 char *algorithm
, *comment
;
3288 tried_pubkey_config
= TRUE
;
3291 * Try the public key supplied in the configuration.
3293 * First, offer the public blob to see if the server is
3294 * willing to accept it.
3296 pub_blob
= ssh2_userkey_loadpub(cfg
.keyfile
, &algorithm
,
3299 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
3300 ssh2_pkt_addstring(username
);
3301 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3302 ssh2_pkt_addstring("publickey");/* method */
3303 ssh2_pkt_addbool(FALSE
); /* no signature included */
3304 ssh2_pkt_addstring(algorithm
);
3305 ssh2_pkt_addstring_start();
3306 ssh2_pkt_addstring_data(pub_blob
, pub_blob_len
);
3308 logevent("Offered public key"); /* FIXME */
3310 crWaitUntilV(ispkt
);
3311 if (pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
3313 type
= AUTH_TYPE_PUBLICKEY_OFFER_LOUD
;
3314 continue; /* key refused; give up on it */
3317 logevent("Offer of public key accepted");
3319 * Actually attempt a serious authentication using
3322 if (ssh2_userkey_encrypted(cfg
.keyfile
, &comment
)) {
3323 sprintf(pwprompt
, "Passphrase for key \"%.100s\": ", comment
);
3328 c_write_str("Authenticating with public key \"");
3329 c_write_str(comment
);
3330 c_write_str("\"\r\n");
3331 method
= AUTH_PUBLICKEY_FILE
;
3335 if (!method
&& can_passwd
) {
3336 method
= AUTH_PASSWORD
;
3337 sprintf(pwprompt
, "%.90s@%.90s's password: ", username
, savedhost
);
3343 if (!ssh_get_line(pwprompt
, password
,
3344 sizeof(password
), TRUE
)) {
3346 * get_line failed to get a password (for
3347 * example because one was supplied on the
3348 * command line which has already failed to
3351 logevent("No more passwords to try");
3352 ssh_state
= SSH_STATE_CLOSED
;
3359 c_write_str(pwprompt
);
3364 crWaitUntilV(!ispkt
);
3365 while (inlen
--) switch (c
= *in
++) {
3382 if (((c
>= ' ' && c
<= '~') ||
3383 ((unsigned char)c
>= 160)) && pos
< 40)
3384 password
[pos
++] = c
;
3388 c_write_str("\r\n");
3392 if (method
== AUTH_PUBLICKEY_FILE
) {
3394 * We have our passphrase. Now try the actual authentication.
3396 struct ssh2_userkey
*key
;
3398 key
= ssh2_load_userkey(cfg
.keyfile
, password
);
3399 if (key
== SSH2_WRONG_PASSPHRASE
|| key
== NULL
) {
3400 if (key
== SSH2_WRONG_PASSPHRASE
) {
3401 c_write_str("Wrong passphrase\r\n");
3402 tried_pubkey_config
= FALSE
;
3404 c_write_str("Unable to load private key\r\n");
3405 tried_pubkey_config
= TRUE
;
3407 /* Send a spurious AUTH_NONE to return to the top. */
3408 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
3409 ssh2_pkt_addstring(username
);
3410 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3411 ssh2_pkt_addstring("none"); /* method */
3413 type
= AUTH_TYPE_NONE
;
3415 unsigned char *blob
, *sigdata
;
3416 int blob_len
, sigdata_len
;
3419 * We have loaded the private key and the server
3420 * has announced that it's willing to accept it.
3421 * Hallelujah. Generate a signature and send it.
3423 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
3424 ssh2_pkt_addstring(username
);
3425 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3426 ssh2_pkt_addstring("publickey"); /* method */
3427 ssh2_pkt_addbool(TRUE
);
3428 ssh2_pkt_addstring(key
->alg
->name
);
3429 blob
= key
->alg
->public_blob(key
->data
, &blob_len
);
3430 ssh2_pkt_addstring_start();
3431 ssh2_pkt_addstring_data(blob
, blob_len
);
3435 * The data to be signed is:
3439 * followed by everything so far placed in the
3442 sigdata_len
= pktout
.length
- 5 + 4 + 20;
3443 sigdata
= smalloc(sigdata_len
);
3444 PUT_32BIT(sigdata
, 20);
3445 memcpy(sigdata
+4, ssh2_session_id
, 20);
3446 memcpy(sigdata
+24, pktout
.data
+5, pktout
.length
-5);
3447 blob
= key
->alg
->sign(key
->data
, sigdata
, sigdata_len
, &blob_len
);
3448 ssh2_pkt_addstring_start();
3449 ssh2_pkt_addstring_data(blob
, blob_len
);
3454 type
= AUTH_TYPE_PUBLICKEY
;
3456 } else if (method
== AUTH_PASSWORD
) {
3458 * We send the password packet lumped tightly together with
3459 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
3460 * string long enough to make the total length of the two
3461 * packets constant. This should ensure that a passive
3462 * listener doing traffic analyis can't work out the length
3465 * For this to work, we need an assumption about the
3466 * maximum length of the password packet. I think 256 is
3467 * pretty conservative. Anyone using a password longer than
3468 * that probably doesn't have much to worry about from
3469 * people who find out how long their password is!
3471 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
3472 ssh2_pkt_addstring(username
);
3473 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3474 ssh2_pkt_addstring("password");
3475 ssh2_pkt_addbool(FALSE
);
3476 ssh2_pkt_addstring(password
);
3479 * We'll include a string that's an exact multiple of the
3480 * cipher block size. If the cipher is NULL for some
3481 * reason, we don't do this trick at all because we gain
3487 stringlen
= (256 - deferred_len
);
3488 stringlen
+= cscipher
->blksize
- 1;
3489 stringlen
-= (stringlen
% cscipher
->blksize
);
3492 * Temporarily disable actual compression,
3493 * so we can guarantee to get this string
3494 * exactly the length we want it. The
3495 * compression-disabling routine should
3496 * return an integer indicating how many
3497 * bytes we should adjust our string length
3500 stringlen
-= cscomp
->disable_compression();
3502 ssh2_pkt_init(SSH2_MSG_IGNORE
);
3503 ssh2_pkt_addstring_start();
3504 for (i
= 0; i
< stringlen
; i
++) {
3505 char c
= (char)random_byte();
3506 ssh2_pkt_addstring_data(&c
, 1);
3510 ssh_pkt_defersend();
3511 logevent("Sent password");
3512 type
= AUTH_TYPE_PASSWORD
;
3514 c_write_str("No supported authentication methods left to try!\r\n");
3515 logevent("No supported authentications offered. Disconnecting");
3516 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
3517 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
3518 ssh2_pkt_addstring("No supported authentication methods available");
3519 ssh2_pkt_addstring("en"); /* language tag */
3521 ssh_state
= SSH_STATE_CLOSED
;
3525 } while (!we_are_in
);
3528 * Now we're authenticated for the connection protocol. The
3529 * connection protocol will automatically have started at this
3530 * point; there's no need to send SERVICE_REQUEST.
3534 * So now create a channel with a session in it.
3536 ssh_channels
= newtree234(ssh_channelcmp
);
3537 mainchan
= smalloc(sizeof(struct ssh_channel
));
3538 mainchan
->localid
= alloc_channel_id();
3539 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
3540 ssh2_pkt_addstring("session");
3541 ssh2_pkt_adduint32(mainchan
->localid
);
3542 ssh2_pkt_adduint32(0x8000UL
); /* our window size */
3543 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
3545 crWaitUntilV(ispkt
);
3546 if (pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
3547 bombout(("Server refused to open a session"));
3549 /* FIXME: error data comes back in FAILURE packet */
3551 if (ssh2_pkt_getuint32() != mainchan
->localid
) {
3552 bombout(("Server's channel confirmation cited wrong channel"));
3555 mainchan
->remoteid
= ssh2_pkt_getuint32();
3556 mainchan
->type
= CHAN_MAINSESSION
;
3557 mainchan
->closes
= 0;
3558 mainchan
->v2
.remwindow
= ssh2_pkt_getuint32();
3559 mainchan
->v2
.remmaxpkt
= ssh2_pkt_getuint32();
3560 mainchan
->v2
.outbuffer
= NULL
;
3561 mainchan
->v2
.outbuflen
= mainchan
->v2
.outbufsize
= 0;
3562 add234(ssh_channels
, mainchan
);
3563 logevent("Opened channel for session");
3566 * Potentially enable X11 forwarding.
3568 if (cfg
.x11_forward
) {
3569 char proto
[20], data
[64];
3570 logevent("Requesting X11 forwarding");
3571 x11_invent_auth(proto
, sizeof(proto
), data
, sizeof(data
));
3572 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
3573 ssh2_pkt_adduint32(mainchan
->remoteid
);
3574 ssh2_pkt_addstring("x11-req");
3575 ssh2_pkt_addbool(1); /* want reply */
3576 ssh2_pkt_addbool(0); /* many connections */
3577 ssh2_pkt_addstring(proto
);
3578 ssh2_pkt_addstring(data
);
3579 ssh2_pkt_adduint32(0); /* screen number */
3583 crWaitUntilV(ispkt
);
3584 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
3585 unsigned i
= ssh2_pkt_getuint32();
3586 struct ssh_channel
*c
;
3587 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
3589 continue; /* nonexistent channel */
3590 c
->v2
.remwindow
+= ssh2_pkt_getuint32();
3592 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
3594 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
3595 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
3596 bombout(("Server got confused by X11 forwarding request"));
3599 logevent("X11 forwarding refused");
3601 logevent("X11 forwarding enabled");
3602 ssh_X11_fwd_enabled
= TRUE
;
3607 * Potentially enable agent forwarding.
3609 if (cfg
.agentfwd
&& agent_exists()) {
3610 logevent("Requesting OpenSSH-style agent forwarding");
3611 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
3612 ssh2_pkt_adduint32(mainchan
->remoteid
);
3613 ssh2_pkt_addstring("auth-agent-req@openssh.com");
3614 ssh2_pkt_addbool(1); /* want reply */
3618 crWaitUntilV(ispkt
);
3619 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
3620 unsigned i
= ssh2_pkt_getuint32();
3621 struct ssh_channel
*c
;
3622 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
3624 continue; /* nonexistent channel */
3625 c
->v2
.remwindow
+= ssh2_pkt_getuint32();
3627 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
3629 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
3630 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
3631 bombout(("Server got confused by agent forwarding request"));
3634 logevent("Agent forwarding refused");
3636 logevent("Agent forwarding enabled");
3637 ssh_agentfwd_enabled
= TRUE
;
3642 * Now allocate a pty for the session.
3645 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
3646 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
3647 ssh2_pkt_addstring("pty-req");
3648 ssh2_pkt_addbool(1); /* want reply */
3649 ssh2_pkt_addstring(cfg
.termtype
);
3650 ssh2_pkt_adduint32(cols
);
3651 ssh2_pkt_adduint32(rows
);
3652 ssh2_pkt_adduint32(0); /* pixel width */
3653 ssh2_pkt_adduint32(0); /* pixel height */
3654 ssh2_pkt_addstring_start();
3655 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
3657 ssh_state
= SSH_STATE_INTERMED
;
3660 crWaitUntilV(ispkt
);
3661 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
3662 unsigned i
= ssh2_pkt_getuint32();
3663 struct ssh_channel
*c
;
3664 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
3666 continue; /* nonexistent channel */
3667 c
->v2
.remwindow
+= ssh2_pkt_getuint32();
3669 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
3671 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
3672 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
3673 bombout(("Server got confused by pty request"));
3676 c_write_str("Server refused to allocate pty\r\n");
3677 ssh_editing
= ssh_echoing
= 1;
3679 logevent("Allocated pty");
3682 ssh_editing
= ssh_echoing
= 1;
3686 * Start a shell or a remote command.
3688 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
3689 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
3690 if (cfg
.ssh_subsys
) {
3691 ssh2_pkt_addstring("subsystem");
3692 ssh2_pkt_addbool(1); /* want reply */
3693 ssh2_pkt_addstring(cfg
.remote_cmd_ptr
);
3694 } else if (*cfg
.remote_cmd_ptr
) {
3695 ssh2_pkt_addstring("exec");
3696 ssh2_pkt_addbool(1); /* want reply */
3697 ssh2_pkt_addstring(cfg
.remote_cmd_ptr
);
3699 ssh2_pkt_addstring("shell");
3700 ssh2_pkt_addbool(1); /* want reply */
3704 crWaitUntilV(ispkt
);
3705 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
3706 unsigned i
= ssh2_pkt_getuint32();
3707 struct ssh_channel
*c
;
3708 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
3710 continue; /* nonexistent channel */
3711 c
->v2
.remwindow
+= ssh2_pkt_getuint32();
3713 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
3714 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
3715 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
3716 bombout(("Server got confused by shell/command request"));
3719 bombout(("Server refused to start a shell/command"));
3722 logevent("Started a shell/command");
3725 ssh_state
= SSH_STATE_SESSION
;
3729 ssh_special(TS_EOF
);
3734 ldisc_send(NULL
, 0); /* cause ldisc to notice changes */
3737 static int try_send
;
3741 if (pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
3742 pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
3745 unsigned i
= ssh2_pkt_getuint32();
3746 struct ssh_channel
*c
;
3747 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
3749 continue; /* nonexistent channel */
3750 if (pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
3751 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR
)
3752 continue; /* extended but not stderr */
3753 ssh2_pkt_getstring(&data
, &length
);
3756 case CHAN_MAINSESSION
:
3757 from_backend(pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
,
3761 x11_send(c
->u
.x11
.s
, data
, length
);
3764 while (length
> 0) {
3765 if (c
->u
.a
.lensofar
< 4) {
3766 int l
= min(4 - c
->u
.a
.lensofar
, length
);
3767 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, data
, l
);
3768 data
+= l
; length
-= l
; c
->u
.a
.lensofar
+= l
;
3770 if (c
->u
.a
.lensofar
== 4) {
3771 c
->u
.a
.totallen
= 4 + GET_32BIT(c
->u
.a
.msglen
);
3772 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
3773 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
3775 if (c
->u
.a
.lensofar
>= 4 && length
> 0) {
3776 int l
= min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
3778 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, data
, l
);
3779 data
+= l
; length
-= l
; c
->u
.a
.lensofar
+= l
;
3781 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
3782 void *reply
, *sentreply
;
3784 agent_query(c
->u
.a
.message
, c
->u
.a
.totallen
,
3789 /* Fake SSH_AGENT_FAILURE. */
3790 sentreply
= "\0\0\0\1\5";
3793 ssh2_add_channel_data(c
, sentreply
, replylen
);
3797 sfree(c
->u
.a
.message
);
3798 c
->u
.a
.lensofar
= 0;
3804 * Enlarge the window again at the remote
3805 * side, just in case it ever runs down and
3806 * they fail to send us any more data.
3808 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
3809 ssh2_pkt_adduint32(c
->remoteid
);
3810 ssh2_pkt_adduint32(length
);
3813 } else if (pktin
.type
== SSH2_MSG_DISCONNECT
) {
3814 ssh_state
= SSH_STATE_CLOSED
;
3815 logevent("Received disconnect message");
3817 } else if (pktin
.type
== SSH2_MSG_CHANNEL_REQUEST
) {
3818 continue; /* exit status et al; ignore (FIXME?) */
3819 } else if (pktin
.type
== SSH2_MSG_CHANNEL_EOF
) {
3820 unsigned i
= ssh2_pkt_getuint32();
3821 struct ssh_channel
*c
;
3823 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
3825 continue; /* nonexistent channel */
3827 if (c
->type
== CHAN_X11
) {
3829 * Remote EOF on an X11 channel means we should
3830 * wrap up and close the channel ourselves.
3832 x11_close(c
->u
.x11
.s
);
3834 } else if (c
->type
== CHAN_AGENT
) {
3837 } else if (pktin
.type
== SSH2_MSG_CHANNEL_CLOSE
) {
3838 unsigned i
= ssh2_pkt_getuint32();
3839 struct ssh_channel
*c
;
3841 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
3843 continue; /* nonexistent channel */
3844 if (c
->closes
== 0) {
3845 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
3846 ssh2_pkt_adduint32(c
->remoteid
);
3849 /* Do pre-close processing on the channel. */
3851 case CHAN_MAINSESSION
:
3852 break; /* nothing to see here, move along */
3858 del234(ssh_channels
, c
);
3859 sfree(c
->v2
.outbuffer
);
3863 * See if that was the last channel left open.
3865 if (count234(ssh_channels
) == 0) {
3866 logevent("All channels closed. Disconnecting");
3867 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
3868 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
3869 ssh2_pkt_addstring("All open channels closed");
3870 ssh2_pkt_addstring("en"); /* language tag */
3872 ssh_state
= SSH_STATE_CLOSED
;
3875 continue; /* remote sends close; ignore (FIXME) */
3876 } else if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
3877 unsigned i
= ssh2_pkt_getuint32();
3878 struct ssh_channel
*c
;
3879 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
3881 continue; /* nonexistent channel */
3882 c
->v2
.remwindow
+= ssh2_pkt_getuint32();
3884 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN
) {
3888 struct ssh_channel
*c
;
3889 ssh2_pkt_getstring(&type
, &typelen
);
3890 c
= smalloc(sizeof(struct ssh_channel
));
3892 if (typelen
== 3 && !memcmp(type
, "x11", 3)) {
3893 if (!ssh_X11_fwd_enabled
)
3894 error
= "X11 forwarding is not enabled";
3895 else if ( x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
) != NULL
) {
3896 error
= "Unable to open an X11 connection";
3900 } else if (typelen
== 22 &&
3901 !memcmp(type
, "auth-agent@openssh.com", 3)) {
3902 if (!ssh_agentfwd_enabled
)
3903 error
= "Agent forwarding is not enabled";
3905 c
->type
= CHAN_AGENT
; /* identify channel type */
3906 c
->u
.a
.lensofar
= 0;
3909 error
= "Unsupported channel type requested";
3912 c
->remoteid
= ssh2_pkt_getuint32();
3914 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE
);
3915 ssh2_pkt_adduint32(c
->remoteid
);
3916 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED
);
3917 ssh2_pkt_addstring(error
);
3918 ssh2_pkt_addstring("en"); /* language tag */
3922 c
->localid
= alloc_channel_id();
3924 c
->v2
.remwindow
= ssh2_pkt_getuint32();
3925 c
->v2
.remmaxpkt
= ssh2_pkt_getuint32();
3926 c
->v2
.outbuffer
= NULL
;
3927 c
->v2
.outbuflen
= c
->v2
.outbufsize
= 0;
3928 add234(ssh_channels
, c
);
3929 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
3930 ssh2_pkt_adduint32(c
->remoteid
);
3931 ssh2_pkt_adduint32(c
->localid
);
3932 ssh2_pkt_adduint32(0x8000UL
); /* our window size */
3933 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
3937 bombout(("Strange packet received: type %d", pktin
.type
));
3942 * We have spare data. Add it to the channel buffer.
3944 ssh2_add_channel_data(mainchan
, in
, inlen
);
3949 struct ssh_channel
*c
;
3951 * Try to send data on all channels if we can.
3953 for (i
= 0; NULL
!= (c
= index234(ssh_channels
, i
)); i
++)
3962 * Handle the top-level SSH2 protocol.
3964 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
)
3966 if (do_ssh2_transport(in
, inlen
, ispkt
) == 0)
3968 do_ssh2_authconn(in
, inlen
, ispkt
);
3972 * Called to set up the connection.
3974 * Returns an error message, or NULL on success.
3976 static char *ssh_init (char *host
, int port
, char **realhost
) {
3980 if(crypto_startup() == 0)
3981 return "Microsoft high encryption pack not installed!";
3988 p
= connect_to_host(host
, port
, realhost
);
3996 * Called to send data down the Telnet connection.
3998 static void ssh_send (char *buf
, int len
) {
3999 if (s
== NULL
|| ssh_protocol
== NULL
)
4002 ssh_protocol(buf
, len
, 0);
4006 * Called to set the size of the window from SSH's POV.
4008 static void ssh_size(void) {
4009 switch (ssh_state
) {
4010 case SSH_STATE_BEFORE_SIZE
:
4011 case SSH_STATE_PREPACKET
:
4012 case SSH_STATE_CLOSED
:
4013 break; /* do nothing */
4014 case SSH_STATE_INTERMED
:
4015 size_needed
= TRUE
; /* buffer for later */
4017 case SSH_STATE_SESSION
:
4019 if (ssh_version
== 1) {
4020 send_packet(SSH1_CMSG_WINDOW_SIZE
,
4021 PKT_INT
, rows
, PKT_INT
, cols
,
4022 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
4024 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4025 ssh2_pkt_adduint32(mainchan
->remoteid
);
4026 ssh2_pkt_addstring("window-change");
4027 ssh2_pkt_addbool(0);
4028 ssh2_pkt_adduint32(cols
);
4029 ssh2_pkt_adduint32(rows
);
4030 ssh2_pkt_adduint32(0);
4031 ssh2_pkt_adduint32(0);
4040 * Send Telnet special codes. TS_EOF is useful for `plink', so you
4041 * can send an EOF and collect resulting output (e.g. `plink
4044 static void ssh_special (Telnet_Special code
) {
4045 if (code
== TS_EOF
) {
4046 if (ssh_state
!= SSH_STATE_SESSION
) {
4048 * Buffer the EOF in case we are pre-SESSION, so we can
4049 * send it as soon as we reach SESSION.
4055 if (ssh_version
== 1) {
4056 send_packet(SSH1_CMSG_EOF
, PKT_END
);
4058 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF
);
4059 ssh2_pkt_adduint32(mainchan
->remoteid
);
4062 logevent("Sent EOF message");
4063 } else if (code
== TS_PING
) {
4064 if (ssh_state
== SSH_STATE_CLOSED
|| ssh_state
== SSH_STATE_PREPACKET
)
4066 if (ssh_version
== 1) {
4067 send_packet(SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
4069 ssh2_pkt_init(SSH2_MSG_IGNORE
);
4070 ssh2_pkt_addstring_start();
4078 static Socket
ssh_socket(void) { return s
; }
4080 static int ssh_sendok(void) { return ssh_send_ok
; }
4082 static int ssh_ldisc(int option
) {
4083 if (option
== LD_ECHO
) return ssh_echoing
;
4084 if (option
== LD_EDIT
) return ssh_editing
;
4088 Backend ssh_backend
= {