18 #define logevent(s) { logevent(s); \
19 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
20 fprintf(stderr, "%s\n", s); }
22 #define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, sk_close(s), \
23 s = NULL, connection_fatal msg )
25 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
26 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
27 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
28 #define SSH1_CMSG_USER 4 /* 0x4 */
29 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
30 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
31 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
32 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
33 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
34 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
35 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
36 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
37 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
38 #define SSH1_SMSG_FAILURE 15 /* 0xf */
39 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
40 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
41 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
42 #define SSH1_CMSG_EOF 19 /* 0x13 */
43 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
44 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
45 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
46 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
47 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
48 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
49 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
50 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
51 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
52 #define SSH1_MSG_IGNORE 32 /* 0x20 */
53 #define SSH1_MSG_DEBUG 36 /* 0x24 */
54 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
55 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
56 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
57 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
58 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
59 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
60 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
62 #define SSH1_AUTH_TIS 5 /* 0x5 */
63 #define SSH1_AUTH_CCARD 16 /* 0x10 */
65 #define SSH_AGENTC_REQUEST_RSA_IDENTITIES 1 /* 0x1 */
66 #define SSH_AGENT_RSA_IDENTITIES_ANSWER 2 /* 0x2 */
67 #define SSH_AGENTC_RSA_CHALLENGE 3 /* 0x3 */
68 #define SSH_AGENT_RSA_RESPONSE 4 /* 0x4 */
69 #define SSH_AGENT_FAILURE 5 /* 0x5 */
70 #define SSH_AGENT_SUCCESS 6 /* 0x6 */
71 #define SSH_AGENTC_ADD_RSA_IDENTITY 7 /* 0x7 */
72 #define SSH_AGENTC_REMOVE_RSA_IDENTITY 8 /* 0x8 */
74 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
75 #define SSH2_MSG_IGNORE 2 /* 0x2 */
76 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
77 #define SSH2_MSG_DEBUG 4 /* 0x4 */
78 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
79 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
80 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
81 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
82 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
83 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
84 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
85 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
86 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
87 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
88 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
89 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
90 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
91 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
92 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
93 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
94 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
95 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
96 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
97 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
98 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
99 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
100 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
101 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
102 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
103 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
105 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
106 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
107 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
108 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
109 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
110 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
111 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
112 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
113 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
114 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
115 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
117 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
118 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
119 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
120 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
122 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
124 #define GET_32BIT(cp) \
125 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
126 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
127 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
128 ((unsigned long)(unsigned char)(cp)[3]))
130 #define PUT_32BIT(cp, value) { \
131 (cp)[0] = (unsigned char)((value) >> 24); \
132 (cp)[1] = (unsigned char)((value) >> 16); \
133 (cp)[2] = (unsigned char)((value) >> 8); \
134 (cp)[3] = (unsigned char)(value); }
136 enum { PKT_END
, PKT_INT
, PKT_CHAR
, PKT_DATA
, PKT_STR
, PKT_BIGNUM
};
138 /* Coroutine mechanics for the sillier bits of the code */
139 #define crBegin1 static int crLine = 0;
140 #define crBegin2 switch(crLine) { case 0:;
141 #define crBegin crBegin1; crBegin2;
142 #define crFinish(z) } crLine = 0; return (z)
143 #define crFinishV } crLine = 0; return
144 #define crReturn(z) \
146 crLine=__LINE__; return (z); case __LINE__:;\
150 crLine=__LINE__; return; case __LINE__:;\
152 #define crStop(z) do{ crLine = 0; return (z); }while(0)
153 #define crStopV do{ crLine = 0; return; }while(0)
154 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
155 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
157 extern const struct ssh_cipher ssh_3des
;
158 extern const struct ssh_cipher ssh_3des_ssh2
;
159 extern const struct ssh_cipher ssh_des
;
160 extern const struct ssh_cipher ssh_blowfish_ssh1
;
161 extern const struct ssh_cipher ssh_blowfish_ssh2
;
164 * Ciphers for SSH2. We miss out single-DES because it isn't
165 * supported; also 3DES and Blowfish are both done differently from
166 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
167 * endianness and different-sized keys.)
169 const static struct ssh_cipher
*ciphers
[] = { &ssh_blowfish_ssh2
, &ssh_3des_ssh2
};
171 extern const struct ssh_kex ssh_diffiehellman
;
172 const static struct ssh_kex
*kex_algs
[] = { &ssh_diffiehellman
};
174 extern const struct ssh_signkey ssh_dss
;
175 const static struct ssh_signkey
*hostkey_algs
[] = { &ssh_dss
};
177 extern const struct ssh_mac ssh_md5
, ssh_sha1
, ssh_sha1_buggy
;
179 static void nullmac_key(unsigned char *key
) { }
180 static void nullmac_generate(unsigned char *blk
, int len
, unsigned long seq
) { }
181 static int nullmac_verify(unsigned char *blk
, int len
, unsigned long seq
) { return 1; }
182 const static struct ssh_mac ssh_mac_none
= {
183 nullmac_key
, nullmac_key
, nullmac_generate
, nullmac_verify
, "none", 0
185 const static struct ssh_mac
*macs
[] = {
186 &ssh_sha1
, &ssh_md5
, &ssh_mac_none
};
187 const static struct ssh_mac
*buggymacs
[] = {
188 &ssh_sha1_buggy
, &ssh_md5
, &ssh_mac_none
};
190 static void ssh_comp_none_init(void) { }
191 static int ssh_comp_none_block(unsigned char *block
, int len
,
192 unsigned char **outblock
, int *outlen
) {
195 const static struct ssh_compress ssh_comp_none
= {
197 ssh_comp_none_init
, ssh_comp_none_block
,
198 ssh_comp_none_init
, ssh_comp_none_block
200 extern const struct ssh_compress ssh_zlib
;
201 const static struct ssh_compress
*compressions
[] = {
202 &ssh_zlib
, &ssh_comp_none
};
205 * 2-3-4 tree storing channels.
208 unsigned remoteid
, localid
;
212 struct ssh_agent_channel
{
213 unsigned char *message
;
214 unsigned char msglen
[4];
215 int lensofar
, totallen
;
217 struct ssh2_data_channel
{
218 unsigned char *outbuffer
;
219 unsigned outbuflen
, outbufsize
;
220 unsigned remwindow
, remmaxpkt
;
234 static SHA_State exhash
, exhashbase
;
236 static Socket s
= NULL
;
238 static unsigned char session_key
[32];
239 static int ssh1_compressing
;
240 static int ssh_agentfwd_enabled
;
241 static const struct ssh_cipher
*cipher
= NULL
;
242 static const struct ssh_cipher
*cscipher
= NULL
;
243 static const struct ssh_cipher
*sccipher
= NULL
;
244 static const struct ssh_mac
*csmac
= NULL
;
245 static const struct ssh_mac
*scmac
= NULL
;
246 static const struct ssh_compress
*cscomp
= NULL
;
247 static const struct ssh_compress
*sccomp
= NULL
;
248 static const struct ssh_kex
*kex
= NULL
;
249 static const struct ssh_signkey
*hostkey
= NULL
;
250 int (*ssh_get_password
)(const char *prompt
, char *str
, int maxlen
) = NULL
;
252 static char *savedhost
;
253 static int savedport
;
254 static int ssh_send_ok
;
256 static tree234
*ssh_channels
; /* indexed by local id */
257 static struct ssh_channel
*mainchan
; /* primary session channel */
261 SSH_STATE_BEFORE_SIZE
,
265 } ssh_state
= SSH_STATE_PREPACKET
;
267 static int size_needed
= FALSE
, eof_needed
= FALSE
;
269 static struct Packet pktin
= { 0, 0, NULL
, NULL
, 0 };
270 static struct Packet pktout
= { 0, 0, NULL
, NULL
, 0 };
272 static int ssh_version
;
273 static void (*ssh_protocol
)(unsigned char *in
, int inlen
, int ispkt
);
274 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
);
275 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
);
276 static void ssh_size(void);
277 static void ssh_special (Telnet_Special
);
279 static int (*s_rdpkt
)(unsigned char **data
, int *datalen
);
281 static struct rdpkt1_state_tag
{
282 long len
, pad
, biglen
, to_read
;
283 unsigned long realcrc
, gotcrc
;
289 static struct rdpkt2_state_tag
{
290 long len
, pad
, payload
, packetlen
, maclen
;
293 unsigned long incoming_sequence
;
296 static int ssh_channelcmp(void *av
, void *bv
) {
297 struct ssh_channel
*a
= (struct ssh_channel
*)av
;
298 struct ssh_channel
*b
= (struct ssh_channel
*)bv
;
299 if (a
->localid
< b
->localid
) return -1;
300 if (a
->localid
> b
->localid
) return +1;
303 static int ssh_channelfind(void *av
, void *bv
) {
304 unsigned *a
= (unsigned *)av
;
305 struct ssh_channel
*b
= (struct ssh_channel
*)bv
;
306 if (*a
< b
->localid
) return -1;
307 if (*a
> b
->localid
) return +1;
311 static void c_write (char *buf
, int len
) {
312 if ((flags
& FLAG_STDERR
)) {
314 for (i
= 0; i
< len
; i
++)
316 fputc(buf
[i
], stderr
);
319 from_backend(1, buf
, len
);
323 * Collect incoming data in the incoming packet buffer.
324 * Decipher and verify the packet when it is completely read.
325 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
326 * Update the *data and *datalen variables.
327 * Return the additional nr of bytes needed, or 0 when
328 * a complete packet is available.
330 static int ssh1_rdpkt(unsigned char **data
, int *datalen
)
332 struct rdpkt1_state_tag
*st
= &rdpkt1_state
;
341 for (st
->i
= st
->len
= 0; st
->i
< 4; st
->i
++) {
342 while ((*datalen
) == 0)
344 st
->len
= (st
->len
<< 8) + **data
;
345 (*data
)++, (*datalen
)--;
349 if (st
->len
== 0x52656d6f) { /* "Remo"te server has closed ... */
350 st
->len
= 0x300; /* big enough to carry to end */
354 st
->pad
= 8 - (st
->len
% 8);
355 st
->biglen
= st
->len
+ st
->pad
;
356 pktin
.length
= st
->len
- 5;
358 if (pktin
.maxlen
< st
->biglen
) {
359 pktin
.maxlen
= st
->biglen
;
360 pktin
.data
= (pktin
.data
== NULL ?
smalloc(st
->biglen
+APIEXTRA
) :
361 srealloc(pktin
.data
, st
->biglen
+APIEXTRA
));
363 fatalbox("Out of memory");
366 st
->to_read
= st
->biglen
;
368 while (st
->to_read
> 0) {
369 st
->chunk
= st
->to_read
;
370 while ((*datalen
) == 0)
371 crReturn(st
->to_read
);
372 if (st
->chunk
> (*datalen
))
373 st
->chunk
= (*datalen
);
374 memcpy(st
->p
, *data
, st
->chunk
);
376 *datalen
-= st
->chunk
;
378 st
->to_read
-= st
->chunk
;
382 cipher
->decrypt(pktin
.data
, st
->biglen
);
384 debug(("Got packet len=%d pad=%d\r\n", st
->len
, st
->pad
));
385 for (st
->i
= 0; st
->i
< st
->biglen
; st
->i
++)
386 debug((" %02x", (unsigned char)pktin
.data
[st
->i
]));
390 st
->realcrc
= crc32(pktin
.data
, st
->biglen
-4);
391 st
->gotcrc
= GET_32BIT(pktin
.data
+st
->biglen
-4);
392 if (st
->gotcrc
!= st
->realcrc
) {
393 bombout(("Incorrect CRC received on packet"));
397 pktin
.body
= pktin
.data
+ st
->pad
+ 1;
399 if (ssh1_compressing
) {
400 unsigned char *decompblk
;
404 debug(("Packet payload pre-decompression:\n"));
405 for (i
= -1; i
< pktin
.length
; i
++)
406 debug((" %02x", (unsigned char)pktin
.body
[i
]));
409 zlib_decompress_block(pktin
.body
-1, pktin
.length
+1,
410 &decompblk
, &decomplen
);
412 if (pktin
.maxlen
< st
->pad
+ decomplen
) {
413 pktin
.maxlen
= st
->pad
+ decomplen
;
414 pktin
.data
= srealloc(pktin
.data
, pktin
.maxlen
+APIEXTRA
);
415 pktin
.body
= pktin
.data
+ st
->pad
+ 1;
417 fatalbox("Out of memory");
420 memcpy(pktin
.body
-1, decompblk
, decomplen
);
422 pktin
.length
= decomplen
-1;
424 debug(("Packet payload post-decompression:\n"));
425 for (i
= -1; i
< pktin
.length
; i
++)
426 debug((" %02x", (unsigned char)pktin
.body
[i
]));
431 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
432 pktin
.type
== SSH1_SMSG_STDERR_DATA
||
433 pktin
.type
== SSH1_MSG_DEBUG
||
434 pktin
.type
== SSH1_SMSG_AUTH_TIS_CHALLENGE
||
435 pktin
.type
== SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
436 long strlen
= GET_32BIT(pktin
.body
);
437 if (strlen
+ 4 != pktin
.length
) {
438 bombout(("Received data packet with bogus string length"));
443 pktin
.type
= pktin
.body
[-1];
445 if (pktin
.type
== SSH1_MSG_DEBUG
) {
446 /* log debug message */
448 int strlen
= GET_32BIT(pktin
.body
);
449 strcpy(buf
, "Remote: ");
450 if (strlen
> 70) strlen
= 70;
451 memcpy(buf
+8, pktin
.body
+4, strlen
);
452 buf
[8+strlen
] = '\0';
455 } else if (pktin
.type
== SSH1_MSG_IGNORE
) {
463 static int ssh2_rdpkt(unsigned char **data
, int *datalen
)
465 struct rdpkt2_state_tag
*st
= &rdpkt2_state
;
473 st
->cipherblk
= sccipher
->blksize
;
476 if (st
->cipherblk
< 8)
479 if (pktin
.maxlen
< st
->cipherblk
) {
480 pktin
.maxlen
= st
->cipherblk
;
481 pktin
.data
= (pktin
.data
== NULL ?
smalloc(st
->cipherblk
+APIEXTRA
) :
482 srealloc(pktin
.data
, st
->cipherblk
+APIEXTRA
));
484 fatalbox("Out of memory");
488 * Acquire and decrypt the first block of the packet. This will
489 * contain the length and padding details.
491 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
492 while ((*datalen
) == 0)
493 crReturn(st
->cipherblk
-st
->i
);
494 pktin
.data
[st
->i
] = *(*data
)++;
498 if (!memcmp(pktin
.data
, "Remo", 4)) {/* "Remo"te server has closed ... */
503 sccipher
->decrypt(pktin
.data
, st
->cipherblk
);
506 * Now get the length and padding figures.
508 st
->len
= GET_32BIT(pktin
.data
);
509 st
->pad
= pktin
.data
[4];
512 * This enables us to deduce the payload length.
514 st
->payload
= st
->len
- st
->pad
- 1;
516 pktin
.length
= st
->payload
+ 5;
519 * So now we can work out the total packet length.
521 st
->packetlen
= st
->len
+ 4;
522 st
->maclen
= scmac ? scmac
->len
: 0;
525 * Adjust memory allocation if packet is too big.
527 if (pktin
.maxlen
< st
->packetlen
+st
->maclen
) {
528 pktin
.maxlen
= st
->packetlen
+st
->maclen
;
529 pktin
.data
= (pktin
.data
== NULL ?
smalloc(pktin
.maxlen
+APIEXTRA
) :
530 srealloc(pktin
.data
, pktin
.maxlen
+APIEXTRA
));
532 fatalbox("Out of memory");
536 * Read and decrypt the remainder of the packet.
538 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
; st
->i
++) {
539 while ((*datalen
) == 0)
540 crReturn(st
->packetlen
+ st
->maclen
- st
->i
);
541 pktin
.data
[st
->i
] = *(*data
)++;
544 /* Decrypt everything _except_ the MAC. */
546 sccipher
->decrypt(pktin
.data
+ st
->cipherblk
,
547 st
->packetlen
- st
->cipherblk
);
550 debug(("Got packet len=%d pad=%d\r\n", st
->len
, st
->pad
));
551 for (st
->i
= 0; st
->i
< st
->packetlen
; st
->i
++)
552 debug((" %02x", (unsigned char)pktin
.data
[st
->i
]));
559 if (scmac
&& !scmac
->verify(pktin
.data
, st
->len
+4, st
->incoming_sequence
)) {
560 bombout(("Incorrect MAC received on packet"));
563 st
->incoming_sequence
++; /* whether or not we MACed */
566 * Decompress packet payload.
569 unsigned char *newpayload
;
571 if (sccomp
&& sccomp
->decompress(pktin
.data
+5, pktin
.length
-5,
572 &newpayload
, &newlen
)) {
573 if (pktin
.maxlen
< newlen
+5) {
574 pktin
.maxlen
= newlen
+5;
575 pktin
.data
= (pktin
.data
== NULL ?
smalloc(pktin
.maxlen
+APIEXTRA
) :
576 srealloc(pktin
.data
, pktin
.maxlen
+APIEXTRA
));
578 fatalbox("Out of memory");
580 pktin
.length
= 5 + newlen
;
581 memcpy(pktin
.data
+5, newpayload
, newlen
);
583 debug(("Post-decompression payload:\r\n"));
584 for (st
->i
= 0; st
->i
< newlen
; st
->i
++)
585 debug((" %02x", (unsigned char)pktin
.data
[5+st
->i
]));
594 pktin
.type
= pktin
.data
[5];
596 if (pktin
.type
== SSH2_MSG_IGNORE
|| pktin
.type
== SSH2_MSG_DEBUG
)
597 goto next_packet
; /* FIXME: print DEBUG message */
602 static void ssh1_pktout_size(int len
) {
605 len
+= 5; /* type and CRC */
609 pktout
.length
= len
-5;
610 if (pktout
.maxlen
< biglen
) {
611 pktout
.maxlen
= biglen
;
613 /* Allocate enough buffer space for extra block
614 * for MS CryptEncrypt() */
615 pktout
.data
= (pktout
.data
== NULL ?
smalloc(biglen
+12) :
616 srealloc(pktout
.data
, biglen
+12));
618 pktout
.data
= (pktout
.data
== NULL ?
smalloc(biglen
+4) :
619 srealloc(pktout
.data
, biglen
+4));
622 fatalbox("Out of memory");
624 pktout
.body
= pktout
.data
+4+pad
+1;
627 static void s_wrpkt_start(int type
, int len
) {
628 ssh1_pktout_size(len
);
632 static void s_wrpkt(void) {
633 int pad
, len
, biglen
, i
;
636 pktout
.body
[-1] = pktout
.type
;
638 if (ssh1_compressing
) {
639 unsigned char *compblk
;
642 debug(("Packet payload pre-compression:\n"));
643 for (i
= -1; i
< pktout
.length
; i
++)
644 debug((" %02x", (unsigned char)pktout
.body
[i
]));
647 zlib_compress_block(pktout
.body
-1, pktout
.length
+1,
649 ssh1_pktout_size(complen
-1);
650 memcpy(pktout
.body
-1, compblk
, complen
);
653 debug(("Packet payload post-compression:\n"));
654 for (i
= -1; i
< pktout
.length
; i
++)
655 debug((" %02x", (unsigned char)pktout
.body
[i
]));
660 len
= pktout
.length
+ 5; /* type and CRC */
664 for (i
=0; i
<pad
; i
++)
665 pktout
.data
[i
+4] = random_byte();
666 crc
= crc32(pktout
.data
+4, biglen
-4);
667 PUT_32BIT(pktout
.data
+biglen
, crc
);
668 PUT_32BIT(pktout
.data
, len
);
671 debug(("Sending packet len=%d\r\n", biglen
+4));
672 for (i
= 0; i
< biglen
+4; i
++)
673 debug((" %02x", (unsigned char)pktout
.data
[i
]));
677 cipher
->encrypt(pktout
.data
+4, biglen
);
679 sk_write(s
, pktout
.data
, biglen
+4);
683 * Construct a packet with the specified contents and
684 * send it to the server.
686 static void send_packet(int pkttype
, ...)
689 unsigned char *p
, *argp
, argchar
;
690 unsigned long argint
;
691 int pktlen
, argtype
, arglen
;
695 va_start(args
, pkttype
);
696 while ((argtype
= va_arg(args
, int)) != PKT_END
) {
699 (void) va_arg(args
, int);
703 (void) va_arg(args
, char);
707 (void) va_arg(args
, unsigned char *);
708 arglen
= va_arg(args
, int);
712 argp
= va_arg(args
, unsigned char *);
713 arglen
= strlen(argp
);
714 pktlen
+= 4 + arglen
;
717 bn
= va_arg(args
, Bignum
);
718 pktlen
+= ssh1_bignum_length(bn
);
726 s_wrpkt_start(pkttype
, pktlen
);
729 va_start(args
, pkttype
);
730 while ((argtype
= va_arg(args
, int)) != PKT_END
) {
733 argint
= va_arg(args
, int);
734 PUT_32BIT(p
, argint
);
738 argchar
= va_arg(args
, unsigned char);
743 argp
= va_arg(args
, unsigned char *);
744 arglen
= va_arg(args
, int);
745 memcpy(p
, argp
, arglen
);
749 argp
= va_arg(args
, unsigned char *);
750 arglen
= strlen(argp
);
751 PUT_32BIT(p
, arglen
);
752 memcpy(p
+ 4, argp
, arglen
);
756 bn
= va_arg(args
, Bignum
);
757 p
+= ssh1_write_bignum(p
, bn
);
766 static int ssh_versioncmp(char *a
, char *b
) {
768 unsigned long av
, bv
;
770 av
= strtoul(a
, &ae
, 10);
771 bv
= strtoul(b
, &be
, 10);
772 if (av
!= bv
) return (av
< bv ?
-1 : +1);
773 if (*ae
== '.') ae
++;
774 if (*be
== '.') be
++;
775 av
= strtoul(ae
, &ae
, 10);
776 bv
= strtoul(be
, &be
, 10);
777 if (av
!= bv
) return (av
< bv ?
-1 : +1);
783 * Utility routine for putting an SSH-protocol `string' into a SHA
787 static void sha_string(SHA_State
*s
, void *str
, int len
) {
788 unsigned char lenblk
[4];
789 PUT_32BIT(lenblk
, len
);
790 SHA_Bytes(s
, lenblk
, 4);
791 SHA_Bytes(s
, str
, len
);
795 * SSH2 packet construction functions.
797 static void ssh2_pkt_adddata(void *data
, int len
) {
798 pktout
.length
+= len
;
799 if (pktout
.maxlen
< pktout
.length
) {
800 pktout
.maxlen
= pktout
.length
+ 256;
801 pktout
.data
= (pktout
.data
== NULL ?
smalloc(pktout
.maxlen
+APIEXTRA
) :
802 srealloc(pktout
.data
, pktout
.maxlen
+APIEXTRA
));
804 fatalbox("Out of memory");
806 memcpy(pktout
.data
+pktout
.length
-len
, data
, len
);
808 static void ssh2_pkt_addbyte(unsigned char byte
) {
809 ssh2_pkt_adddata(&byte
, 1);
811 static void ssh2_pkt_init(int pkt_type
) {
813 ssh2_pkt_addbyte((unsigned char)pkt_type
);
815 static void ssh2_pkt_addbool(unsigned char value
) {
816 ssh2_pkt_adddata(&value
, 1);
818 static void ssh2_pkt_adduint32(unsigned long value
) {
821 ssh2_pkt_adddata(x
, 4);
823 static void ssh2_pkt_addstring_start(void) {
824 ssh2_pkt_adduint32(0);
825 pktout
.savedpos
= pktout
.length
;
827 static void ssh2_pkt_addstring_str(char *data
) {
828 ssh2_pkt_adddata(data
, strlen(data
));
829 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
830 pktout
.length
- pktout
.savedpos
);
832 static void ssh2_pkt_addstring_data(char *data
, int len
) {
833 ssh2_pkt_adddata(data
, len
);
834 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
835 pktout
.length
- pktout
.savedpos
);
837 static void ssh2_pkt_addstring(char *data
) {
838 ssh2_pkt_addstring_start();
839 ssh2_pkt_addstring_str(data
);
841 static char *ssh2_mpint_fmt(Bignum b
, int *len
) {
844 p
= smalloc(n
* 2 + 1);
846 fatalbox("out of memory");
848 for (i
= 0; i
< n
; i
++) {
849 p
[i
*2+1] = (b
[n
-i
] >> 8) & 0xFF;
850 p
[i
*2+2] = (b
[n
-i
] ) & 0xFF;
853 while (p
[i
] == 0 && (p
[i
+1] & 0x80) == 0)
855 memmove(p
, p
+i
, n
*2+1-i
);
859 static void ssh2_pkt_addmp(Bignum b
) {
862 p
= ssh2_mpint_fmt(b
, &len
);
863 ssh2_pkt_addstring_start();
864 ssh2_pkt_addstring_data(p
, len
);
867 static void ssh2_pkt_send(void) {
868 int cipherblk
, maclen
, padding
, i
;
869 static unsigned long outgoing_sequence
= 0;
872 * Compress packet payload.
875 debug(("Pre-compression payload:\r\n"));
876 for (i
= 5; i
< pktout
.length
; i
++)
877 debug((" %02x", (unsigned char)pktout
.data
[i
]));
881 unsigned char *newpayload
;
883 if (cscomp
&& cscomp
->compress(pktout
.data
+5, pktout
.length
-5,
884 &newpayload
, &newlen
)) {
886 ssh2_pkt_adddata(newpayload
, newlen
);
892 * Add padding. At least four bytes, and must also bring total
893 * length (minus MAC) up to a multiple of the block size.
895 cipherblk
= cipher ? cipher
->blksize
: 8; /* block size */
896 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
898 padding
+= (cipherblk
- (pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
899 pktout
.data
[4] = padding
;
900 for (i
= 0; i
< padding
; i
++)
901 pktout
.data
[pktout
.length
+ i
] = random_byte();
902 PUT_32BIT(pktout
.data
, pktout
.length
+ padding
- 4);
904 csmac
->generate(pktout
.data
, pktout
.length
+ padding
,
906 outgoing_sequence
++; /* whether or not we MACed */
909 debug(("Sending packet len=%d\r\n", pktout
.length
+padding
));
910 for (i
= 0; i
< pktout
.length
+padding
; i
++)
911 debug((" %02x", (unsigned char)pktout
.data
[i
]));
916 cscipher
->encrypt(pktout
.data
, pktout
.length
+ padding
);
917 maclen
= csmac ? csmac
->len
: 0;
919 sk_write(s
, pktout
.data
, pktout
.length
+ padding
+ maclen
);
923 void bndebug(char *string
, Bignum b
) {
926 p
= ssh2_mpint_fmt(b
, &len
);
927 debug(("%s", string
));
928 for (i
= 0; i
< len
; i
++)
929 debug((" %02x", p
[i
]));
935 static void sha_mpint(SHA_State
*s
, Bignum b
) {
938 p
= ssh2_mpint_fmt(b
, &len
);
939 sha_string(s
, p
, len
);
944 * SSH2 packet decode functions.
946 static unsigned long ssh2_pkt_getuint32(void) {
948 if (pktin
.length
- pktin
.savedpos
< 4)
949 return 0; /* arrgh, no way to decline (FIXME?) */
950 value
= GET_32BIT(pktin
.data
+pktin
.savedpos
);
954 static void ssh2_pkt_getstring(char **p
, int *length
) {
956 if (pktin
.length
- pktin
.savedpos
< 4)
958 *length
= GET_32BIT(pktin
.data
+pktin
.savedpos
);
960 if (pktin
.length
- pktin
.savedpos
< *length
)
962 *p
= pktin
.data
+pktin
.savedpos
;
963 pktin
.savedpos
+= *length
;
965 static Bignum
ssh2_pkt_getmp(void) {
970 ssh2_pkt_getstring(&p
, &length
);
974 bombout(("internal error: Can't handle negative mpints"));
977 b
= newbn((length
+1)/2);
978 for (i
= 0; i
< length
; i
++) {
981 b
[j
/2+1] |= ((unsigned char)p
[i
]) << 8;
983 b
[j
/2+1] |= ((unsigned char)p
[i
]);
985 while (b
[0] > 1 && b
[b
[0]] == 0) b
[0]--;
989 static int do_ssh_init(unsigned char c
) {
991 static char version
[10];
992 static char vstring
[80];
993 static char vlog
[sizeof(vstring
)+20];
998 /* Search for the string "SSH-" in the input. */
1001 static const int transS
[] = { 1, 2, 2, 1 };
1002 static const int transH
[] = { 0, 0, 3, 0 };
1003 static const int transminus
[] = { 0, 0, 0, -1 };
1004 if (c
== 'S') i
= transS
[i
];
1005 else if (c
== 'H') i
= transH
[i
];
1006 else if (c
== '-') i
= transminus
[i
];
1010 crReturn(1); /* get another character */
1013 strcpy(vstring
, "SSH-");
1017 crReturn(1); /* get another char */
1018 if (vsp
< vstring
+sizeof(vstring
)-1)
1024 } else if (i
< sizeof(version
)-1)
1031 ssh_agentfwd_enabled
= FALSE
;
1032 rdpkt2_state
.incoming_sequence
= 0;
1035 sprintf(vlog
, "Server version: %s", vstring
);
1036 vlog
[strcspn(vlog
, "\r\n")] = '\0';
1040 * Server version "1.99" means we can choose whether we use v1
1041 * or v2 protocol. Choice is based on cfg.sshprot.
1043 if (ssh_versioncmp(version
, cfg
.sshprot
== 1 ?
"2.0" : "1.99") >= 0) {
1045 * This is a v2 server. Begin v2 protocol.
1047 char *verstring
= "SSH-2.0-PuTTY";
1048 SHA_Init(&exhashbase
);
1050 * Hash our version string and their version string.
1052 sha_string(&exhashbase
, verstring
, strlen(verstring
));
1053 sha_string(&exhashbase
, vstring
, strcspn(vstring
, "\r\n"));
1054 sprintf(vstring
, "%s\n", verstring
);
1055 sprintf(vlog
, "We claim version: %s", verstring
);
1057 logevent("Using SSH protocol version 2");
1058 sk_write(s
, vstring
, strlen(vstring
));
1059 ssh_protocol
= ssh2_protocol
;
1061 s_rdpkt
= ssh2_rdpkt
;
1064 * This is a v1 server. Begin v1 protocol.
1066 sprintf(vstring
, "SSH-%s-PuTTY\n",
1067 (ssh_versioncmp(version
, "1.5") <= 0 ? version
: "1.5"));
1068 sprintf(vlog
, "We claim version: %s", vstring
);
1069 vlog
[strcspn(vlog
, "\r\n")] = '\0';
1071 logevent("Using SSH protocol version 1");
1072 sk_write(s
, vstring
, strlen(vstring
));
1073 ssh_protocol
= ssh1_protocol
;
1075 s_rdpkt
= ssh1_rdpkt
;
1077 ssh_state
= SSH_STATE_BEFORE_SIZE
;
1082 static void ssh_gotdata(unsigned char *data
, int datalen
)
1087 * To begin with, feed the characters one by one to the
1088 * protocol initialisation / selection function do_ssh_init().
1089 * When that returns 0, we're done with the initial greeting
1090 * exchange and can move on to packet discipline.
1095 crReturnV
; /* more data please */
1096 ret
= do_ssh_init(*data
);
1103 * We emerge from that loop when the initial negotiation is
1104 * over and we have selected an s_rdpkt function. Now pass
1105 * everything to s_rdpkt, and then pass the resulting packets
1106 * to the proper protocol handler.
1111 while (datalen
> 0) {
1112 if ( s_rdpkt(&data
, &datalen
) == 0 ) {
1113 ssh_protocol(NULL
, 0, 1);
1114 if (ssh_state
== SSH_STATE_CLOSED
) {
1124 static int ssh_receive(Socket skt
, int urgent
, char *data
, int len
) {
1126 /* Connection has closed. */
1131 ssh_gotdata (data
, len
);
1132 if (ssh_state
== SSH_STATE_CLOSED
) {
1143 * Connect to specified host and port.
1144 * Returns an error message, or NULL on success.
1145 * Also places the canonical host name into `realhost'.
1147 static char *connect_to_host(char *host
, int port
, char **realhost
)
1156 savedhost
= smalloc(1+strlen(host
));
1158 fatalbox("Out of memory");
1159 strcpy(savedhost
, host
);
1162 port
= 22; /* default ssh port */
1175 addr
= sk_namelookup(host
, realhost
);
1176 if ( (err
= sk_addr_error(addr
)) )
1186 s
= sk_new(addr
, port
, ssh_receive
);
1187 if ( (err
= sk_socket_error(s
)) )
1191 sk_write(s
, "connect ", 8);
1192 sk_write(s
, FWhost
, strlen(FWhost
));
1195 sprintf(buf
, " %d\n", FWport
);
1196 sk_write(s
, buf
, strlen(buf
));
1204 * Handle the key exchange and user authentication phases.
1206 static int do_ssh1_login(unsigned char *in
, int inlen
, int ispkt
)
1209 unsigned char *rsabuf
, *keystr1
, *keystr2
;
1210 unsigned char cookie
[8];
1211 struct RSAKey servkey
, hostkey
;
1212 struct MD5Context md5c
;
1213 static unsigned long supported_ciphers_mask
, supported_auths_mask
;
1214 static int tried_publickey
;
1215 static unsigned char session_id
[16];
1217 static char username
[100];
1221 if (!ispkt
) crWaitUntil(ispkt
);
1223 if (pktin
.type
!= SSH1_SMSG_PUBLIC_KEY
) {
1224 bombout(("Public key packet not received"));
1228 logevent("Received public keys");
1230 memcpy(cookie
, pktin
.body
, 8);
1232 i
= makekey(pktin
.body
+8, &servkey
, &keystr1
, 0);
1233 j
= makekey(pktin
.body
+8+i
, &hostkey
, &keystr2
, 0);
1236 * Log the host key fingerprint.
1240 logevent("Host key fingerprint is:");
1241 strcpy(logmsg
, " ");
1242 hostkey
.comment
= NULL
;
1243 rsa_fingerprint(logmsg
+strlen(logmsg
), sizeof(logmsg
)-strlen(logmsg
),
1248 supported_ciphers_mask
= GET_32BIT(pktin
.body
+12+i
+j
);
1249 supported_auths_mask
= GET_32BIT(pktin
.body
+16+i
+j
);
1252 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
1253 MD5Update(&md5c
, keystr1
, servkey
.bytes
);
1254 MD5Update(&md5c
, pktin
.body
, 8);
1255 MD5Final(session_id
, &md5c
);
1257 for (i
=0; i
<32; i
++)
1258 session_key
[i
] = random_byte();
1260 len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
1262 rsabuf
= smalloc(len
);
1264 fatalbox("Out of memory");
1267 * Verify the host key.
1271 * First format the key into a string.
1273 int len
= rsastr_len(&hostkey
);
1274 char fingerprint
[100];
1275 char *keystr
= smalloc(len
);
1277 fatalbox("Out of memory");
1278 rsastr_fmt(keystr
, &hostkey
);
1279 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
1280 verify_ssh_host_key(savedhost
, savedport
, "rsa", keystr
, fingerprint
);
1284 for (i
=0; i
<32; i
++) {
1285 rsabuf
[i
] = session_key
[i
];
1287 rsabuf
[i
] ^= session_id
[i
];
1290 if (hostkey
.bytes
> servkey
.bytes
) {
1291 rsaencrypt(rsabuf
, 32, &servkey
);
1292 rsaencrypt(rsabuf
, servkey
.bytes
, &hostkey
);
1294 rsaencrypt(rsabuf
, 32, &hostkey
);
1295 rsaencrypt(rsabuf
, hostkey
.bytes
, &servkey
);
1298 logevent("Encrypted session key");
1300 cipher_type
= cfg
.cipher
== CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH
:
1301 cfg
.cipher
== CIPHER_DES ? SSH_CIPHER_DES
:
1303 if ((supported_ciphers_mask
& (1 << cipher_type
)) == 0) {
1304 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1305 cipher_type
= SSH_CIPHER_3DES
;
1307 switch (cipher_type
) {
1308 case SSH_CIPHER_3DES
: logevent("Using 3DES encryption"); break;
1309 case SSH_CIPHER_DES
: logevent("Using single-DES encryption"); break;
1310 case SSH_CIPHER_BLOWFISH
: logevent("Using Blowfish encryption"); break;
1313 send_packet(SSH1_CMSG_SESSION_KEY
,
1314 PKT_CHAR
, cipher_type
,
1315 PKT_DATA
, cookie
, 8,
1316 PKT_CHAR
, (len
*8) >> 8, PKT_CHAR
, (len
*8) & 0xFF,
1317 PKT_DATA
, rsabuf
, len
,
1321 logevent("Trying to enable encryption...");
1325 cipher
= cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
1326 cipher_type
== SSH_CIPHER_DES ?
&ssh_des
:
1328 cipher
->sesskey(session_key
);
1332 if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1333 bombout(("Encryption not successfully enabled"));
1337 logevent("Successfully started encryption");
1343 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
1344 c_write("login as: ", 10);
1347 crWaitUntil(!ispkt
);
1348 while (inlen
--) switch (c
= *in
++) {
1355 c_write("\b \b", 3);
1361 c_write("\b \b", 3);
1370 if (((c
>= ' ' && c
<= '~') ||
1371 ((unsigned char)c
>= 160)) && pos
< 40) {
1372 username
[pos
++] = c
;
1379 username
[strcspn(username
, "\n\r")] = '\0';
1381 strncpy(username
, cfg
.username
, 99);
1382 username
[99] = '\0';
1385 send_packet(SSH1_CMSG_USER
, PKT_STR
, username
, PKT_END
);
1387 char userlog
[22+sizeof(username
)];
1388 sprintf(userlog
, "Sent username \"%s\"", username
);
1390 if (flags
& FLAG_INTERACTIVE
&&
1391 (!((flags
& FLAG_STDERR
) && (flags
& FLAG_VERBOSE
)))) {
1392 strcat(userlog
, "\r\n");
1393 c_write(userlog
, strlen(userlog
));
1400 tried_publickey
= 0;
1402 while (pktin
.type
== SSH1_SMSG_FAILURE
) {
1403 static char password
[100];
1404 static char prompt
[200];
1407 static int pwpkt_type
;
1409 * Show password prompt, having first obtained it via a TIS
1410 * or CryptoCard exchange if we're doing TIS or CryptoCard
1413 pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
1414 if (agent_exists()) {
1416 * Attempt RSA authentication using Pageant.
1418 static unsigned char request
[5], *response
, *p
;
1419 static int responselen
;
1420 static int i
, nkeys
;
1421 static int authed
= FALSE
;
1424 logevent("Pageant is running. Requesting keys.");
1426 /* Request the keys held by the agent. */
1427 PUT_32BIT(request
, 1);
1428 request
[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES
;
1429 agent_query(request
, 5, &r
, &responselen
);
1430 response
= (unsigned char *)r
;
1433 nkeys
= GET_32BIT(p
); p
+= 4;
1434 { char buf
[64]; sprintf(buf
, "Pageant has %d keys", nkeys
);
1436 for (i
= 0; i
< nkeys
; i
++) {
1437 static struct RSAKey key
;
1438 static Bignum challenge
;
1439 static char *commentp
;
1440 static int commentlen
;
1442 { char buf
[64]; sprintf(buf
, "Trying Pageant key #%d", i
);
1445 p
+= ssh1_read_bignum(p
, &key
.exponent
);
1446 p
+= ssh1_read_bignum(p
, &key
.modulus
);
1447 commentlen
= GET_32BIT(p
); p
+= 4;
1448 commentp
= p
; p
+= commentlen
;
1449 send_packet(SSH1_CMSG_AUTH_RSA
,
1450 PKT_BIGNUM
, key
.modulus
, PKT_END
);
1452 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
1453 logevent("Key refused");
1456 logevent("Received RSA challenge");
1457 ssh1_read_bignum(pktin
.body
, &challenge
);
1459 char *agentreq
, *q
, *ret
;
1461 len
= 1 + 4; /* message type, bit count */
1462 len
+= ssh1_bignum_length(key
.exponent
);
1463 len
+= ssh1_bignum_length(key
.modulus
);
1464 len
+= ssh1_bignum_length(challenge
);
1465 len
+= 16; /* session id */
1466 len
+= 4; /* response format */
1467 agentreq
= smalloc(4 + len
);
1468 PUT_32BIT(agentreq
, len
);
1470 *q
++ = SSH_AGENTC_RSA_CHALLENGE
;
1471 PUT_32BIT(q
, ssh1_bignum_bitcount(key
.modulus
));
1473 q
+= ssh1_write_bignum(q
, key
.exponent
);
1474 q
+= ssh1_write_bignum(q
, key
.modulus
);
1475 q
+= ssh1_write_bignum(q
, challenge
);
1476 memcpy(q
, session_id
, 16); q
+= 16;
1477 PUT_32BIT(q
, 1); /* response format */
1478 agent_query(agentreq
, len
+4, &ret
, &retlen
);
1481 if (ret
[4] == SSH_AGENT_RSA_RESPONSE
) {
1482 logevent("Sending Pageant's response");
1483 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
1484 PKT_DATA
, ret
+5, 16, PKT_END
);
1487 if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
1488 logevent("Pageant's response accepted");
1489 if (flags
& FLAG_VERBOSE
) {
1490 c_write("Authenticated using RSA key \"",
1492 c_write(commentp
, commentlen
);
1493 c_write("\" from agent\r\n", 14);
1497 logevent("Pageant's response not accepted");
1499 logevent("Pageant failed to answer challenge");
1503 logevent("No reply received from Pageant");
1506 freebn(key
.exponent
);
1507 freebn(key
.modulus
);
1516 if (*cfg
.keyfile
&& !tried_publickey
)
1517 pwpkt_type
= SSH1_CMSG_AUTH_RSA
;
1519 if (pktin
.type
== SSH1_SMSG_FAILURE
&&
1521 (supported_auths_mask
& (1<<SSH1_AUTH_TIS
))) {
1522 pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
1523 logevent("Requested TIS authentication");
1524 send_packet(SSH1_CMSG_AUTH_TIS
, PKT_END
);
1526 if (pktin
.type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
1527 logevent("TIS authentication declined");
1528 if (flags
& FLAG_INTERACTIVE
)
1529 c_write("TIS authentication refused.\r\n", 29);
1531 int challengelen
= ((pktin
.body
[0] << 24) |
1532 (pktin
.body
[1] << 16) |
1533 (pktin
.body
[2] << 8) |
1535 logevent("Received TIS challenge");
1536 if (challengelen
> sizeof(prompt
)-1)
1537 challengelen
= sizeof(prompt
)-1; /* prevent overrun */
1538 memcpy(prompt
, pktin
.body
+4, challengelen
);
1539 prompt
[challengelen
] = '\0';
1542 if (pktin
.type
== SSH1_SMSG_FAILURE
&&
1544 (supported_auths_mask
& (1<<SSH1_AUTH_CCARD
))) {
1545 pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
1546 logevent("Requested CryptoCard authentication");
1547 send_packet(SSH1_CMSG_AUTH_CCARD
, PKT_END
);
1549 if (pktin
.type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
1550 logevent("CryptoCard authentication declined");
1551 c_write("CryptoCard authentication refused.\r\n", 29);
1553 int challengelen
= ((pktin
.body
[0] << 24) |
1554 (pktin
.body
[1] << 16) |
1555 (pktin
.body
[2] << 8) |
1557 logevent("Received CryptoCard challenge");
1558 if (challengelen
> sizeof(prompt
)-1)
1559 challengelen
= sizeof(prompt
)-1; /* prevent overrun */
1560 memcpy(prompt
, pktin
.body
+4, challengelen
);
1561 strncpy(prompt
+ challengelen
, "\r\nResponse : ",
1562 sizeof(prompt
)-challengelen
);
1563 prompt
[sizeof(prompt
)-1] = '\0';
1566 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
1567 sprintf(prompt
, "%.90s@%.90s's password: ",
1568 username
, savedhost
);
1570 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
1571 char *comment
= NULL
;
1572 if (flags
& FLAG_VERBOSE
)
1573 c_write("Trying public key authentication.\r\n", 35);
1574 if (!rsakey_encrypted(cfg
.keyfile
, &comment
)) {
1575 if (flags
& FLAG_VERBOSE
)
1576 c_write("No passphrase required.\r\n", 25);
1579 sprintf(prompt
, "Passphrase for key \"%.100s\": ", comment
);
1583 if (ssh_get_password
) {
1584 if (!ssh_get_password(prompt
, password
, sizeof(password
))) {
1586 * get_password failed to get a password (for
1587 * example because one was supplied on the command
1588 * line which has already failed to work).
1591 logevent("No more passwords to try");
1592 ssh_state
= SSH_STATE_CLOSED
;
1596 c_write(prompt
, strlen(prompt
));
1600 crWaitUntil(!ispkt
);
1601 while (inlen
--) switch (c
= *in
++) {
1618 if (((c
>= ' ' && c
<= '~') ||
1619 ((unsigned char)c
>= 160)) && pos
< sizeof(password
))
1620 password
[pos
++] = c
;
1628 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
1630 * Try public key authentication with the specified
1633 static struct RSAKey pubkey
;
1634 static Bignum challenge
, response
;
1636 static unsigned char buffer
[32];
1638 tried_publickey
= 1;
1639 i
= loadrsakey(cfg
.keyfile
, &pubkey
, NULL
, password
);
1641 c_write("Couldn't load public key from ", 30);
1642 c_write(cfg
.keyfile
, strlen(cfg
.keyfile
));
1643 c_write(".\r\n", 3);
1644 continue; /* go and try password */
1647 c_write("Wrong passphrase.\r\n", 19);
1648 tried_publickey
= 0;
1649 continue; /* try again */
1653 * Send a public key attempt.
1655 send_packet(SSH1_CMSG_AUTH_RSA
,
1656 PKT_BIGNUM
, pubkey
.modulus
, PKT_END
);
1659 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1660 c_write("Server refused our public key.\r\n", 32);
1661 continue; /* go and try password */
1663 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
1664 bombout(("Bizarre response to offer of public key"));
1667 ssh1_read_bignum(pktin
.body
, &challenge
);
1668 response
= rsadecrypt(challenge
, &pubkey
);
1669 freebn(pubkey
.private_exponent
); /* burn the evidence */
1671 for (i
= 0; i
< 32; i
+= 2) {
1672 buffer
[i
] = response
[16-i
/2] >> 8;
1673 buffer
[i
+1] = response
[16-i
/2] & 0xFF;
1677 MD5Update(&md5c
, buffer
, 32);
1678 MD5Update(&md5c
, session_id
, 16);
1679 MD5Final(buffer
, &md5c
);
1681 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
1682 PKT_DATA
, buffer
, 16, PKT_END
);
1685 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1686 if (flags
& FLAG_VERBOSE
)
1687 c_write("Failed to authenticate with our public key.\r\n",
1689 continue; /* go and try password */
1690 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1691 bombout(("Bizarre response to RSA authentication response"));
1695 break; /* we're through! */
1697 send_packet(pwpkt_type
, PKT_STR
, password
, PKT_END
);
1699 logevent("Sent password");
1700 memset(password
, 0, strlen(password
));
1702 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1703 if (flags
& FLAG_VERBOSE
)
1704 c_write("Access denied\r\n", 15);
1705 logevent("Authentication refused");
1706 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
1707 logevent("Received disconnect request");
1708 ssh_state
= SSH_STATE_CLOSED
;
1710 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1711 bombout(("Strange packet received, type %d", pktin
.type
));
1716 logevent("Authentication successful");
1721 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
) {
1726 while (!do_ssh1_login(in
, inlen
, ispkt
)) {
1729 if (ssh_state
== SSH_STATE_CLOSED
)
1732 if (cfg
.agentfwd
&& agent_exists()) {
1733 logevent("Requesting agent forwarding");
1734 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
1735 do { crReturnV
; } while (!ispkt
);
1736 if (pktin
.type
!= SSH1_SMSG_SUCCESS
&& pktin
.type
!= SSH1_SMSG_FAILURE
) {
1737 bombout(("Protocol confusion"));
1739 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1740 logevent("Agent forwarding refused");
1742 logevent("Agent forwarding enabled");
1743 ssh_agentfwd_enabled
= TRUE
;
1748 send_packet(SSH1_CMSG_REQUEST_PTY
,
1749 PKT_STR
, cfg
.termtype
,
1750 PKT_INT
, rows
, PKT_INT
, cols
,
1751 PKT_INT
, 0, PKT_INT
, 0,
1754 ssh_state
= SSH_STATE_INTERMED
;
1755 do { crReturnV
; } while (!ispkt
);
1756 if (pktin
.type
!= SSH1_SMSG_SUCCESS
&& pktin
.type
!= SSH1_SMSG_FAILURE
) {
1757 bombout(("Protocol confusion"));
1759 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1760 c_write("Server refused to allocate pty\r\n", 32);
1762 logevent("Allocated pty");
1765 if (cfg
.compression
) {
1766 send_packet(SSH1_CMSG_REQUEST_COMPRESSION
, PKT_INT
, 6, PKT_END
);
1767 do { crReturnV
; } while (!ispkt
);
1768 if (pktin
.type
!= SSH1_SMSG_SUCCESS
&& pktin
.type
!= SSH1_SMSG_FAILURE
) {
1769 bombout(("Protocol confusion"));
1771 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1772 c_write("Server refused to compress\r\n", 32);
1774 logevent("Started compression");
1775 ssh1_compressing
= TRUE
;
1776 zlib_compress_init();
1777 zlib_decompress_init();
1780 if (*cfg
.remote_cmd
)
1781 send_packet(SSH1_CMSG_EXEC_CMD
, PKT_STR
, cfg
.remote_cmd
, PKT_END
);
1783 send_packet(SSH1_CMSG_EXEC_SHELL
, PKT_END
);
1784 logevent("Started session");
1786 ssh_state
= SSH_STATE_SESSION
;
1790 ssh_special(TS_EOF
);
1793 ssh_channels
= newtree234(ssh_channelcmp
);
1798 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
1799 pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
1800 long len
= GET_32BIT(pktin
.body
);
1801 from_backend(pktin
.type
== SSH1_SMSG_STDERR_DATA
,
1803 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
1804 ssh_state
= SSH_STATE_CLOSED
;
1805 logevent("Received disconnect request");
1807 } else if (pktin
.type
== SSH1_SMSG_AGENT_OPEN
) {
1808 /* Remote side is trying to open a channel to talk to our
1809 * agent. Give them back a local channel number. */
1811 struct ssh_channel
*c
;
1814 /* Refuse if agent forwarding is disabled. */
1815 if (!ssh_agentfwd_enabled
) {
1816 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
1817 PKT_INT
, GET_32BIT(pktin
.body
),
1821 for (c
= first234(ssh_channels
, &e
); c
; c
= next234(&e
)) {
1823 break; /* found a free number */
1826 c
= smalloc(sizeof(struct ssh_channel
));
1827 c
->remoteid
= GET_32BIT(pktin
.body
);
1830 c
->type
= SSH1_SMSG_AGENT_OPEN
;/* identify channel type */
1831 c
->u
.a
.lensofar
= 0;
1832 add234(ssh_channels
, c
);
1833 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
1834 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
1837 } else if (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE
||
1838 pktin
.type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
) {
1839 /* Remote side closes a channel. */
1840 unsigned i
= GET_32BIT(pktin
.body
);
1841 struct ssh_channel
*c
;
1842 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
1845 closetype
= (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
1 : 2);
1846 send_packet(pktin
.type
, PKT_INT
, c
->remoteid
, PKT_END
);
1847 c
->closes
|= closetype
;
1848 if (c
->closes
== 3) {
1849 del234(ssh_channels
, c
);
1853 } else if (pktin
.type
== SSH1_MSG_CHANNEL_DATA
) {
1854 /* Data sent down one of our channels. */
1855 int i
= GET_32BIT(pktin
.body
);
1856 int len
= GET_32BIT(pktin
.body
+4);
1857 unsigned char *p
= pktin
.body
+8;
1858 struct ssh_channel
*c
;
1859 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
1862 case SSH1_SMSG_AGENT_OPEN
:
1863 /* Data for an agent message. Buffer it. */
1865 if (c
->u
.a
.lensofar
< 4) {
1866 int l
= min(4 - c
->u
.a
.lensofar
, len
);
1867 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
, l
);
1868 p
+= l
; len
-= l
; c
->u
.a
.lensofar
+= l
;
1870 if (c
->u
.a
.lensofar
== 4) {
1871 c
->u
.a
.totallen
= 4 + GET_32BIT(c
->u
.a
.msglen
);
1872 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
1873 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
1875 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
1876 int l
= min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
, len
);
1877 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
, l
);
1878 p
+= l
; len
-= l
; c
->u
.a
.lensofar
+= l
;
1880 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
1881 void *reply
, *sentreply
;
1883 agent_query(c
->u
.a
.message
, c
->u
.a
.totallen
,
1888 /* Fake SSH_AGENT_FAILURE. */
1889 sentreply
= "\0\0\0\1\5";
1892 send_packet(SSH1_MSG_CHANNEL_DATA
,
1893 PKT_INT
, c
->remoteid
,
1895 PKT_DATA
, sentreply
, replylen
,
1899 sfree(c
->u
.a
.message
);
1900 c
->u
.a
.lensofar
= 0;
1906 } else if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
1907 /* may be from EXEC_SHELL on some servers */
1908 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1909 /* may be from EXEC_SHELL on some servers
1910 * if no pty is available or in other odd cases. Ignore */
1911 } else if (pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
1912 send_packet(SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
1914 bombout(("Strange packet received: type %d", pktin
.type
));
1919 int len
= min(inlen
, 512);
1920 send_packet(SSH1_CMSG_STDIN_DATA
,
1921 PKT_INT
, len
, PKT_DATA
, in
, len
, PKT_END
);
1932 * Utility routine for decoding comma-separated strings in KEXINIT.
1934 static int in_commasep_string(char *needle
, char *haystack
, int haylen
) {
1935 int needlen
= strlen(needle
);
1938 * Is it at the start of the string?
1940 if (haylen
>= needlen
&& /* haystack is long enough */
1941 !memcmp(needle
, haystack
, needlen
) && /* initial match */
1942 (haylen
== needlen
|| haystack
[needlen
] == ',')
1943 /* either , or EOS follows */
1947 * If not, search for the next comma and resume after that.
1948 * If no comma found, terminate.
1950 while (haylen
> 0 && *haystack
!= ',')
1951 haylen
--, haystack
++;
1954 haylen
--, haystack
++; /* skip over comma itself */
1959 * SSH2 key creation method.
1961 static void ssh2_mkkey(Bignum K
, char *H
, char chr
, char *keyspace
) {
1963 /* First 20 bytes. */
1966 SHA_Bytes(&s
, H
, 20);
1967 SHA_Bytes(&s
, &chr
, 1);
1968 SHA_Bytes(&s
, H
, 20);
1969 SHA_Final(&s
, keyspace
);
1970 /* Next 20 bytes. */
1973 SHA_Bytes(&s
, H
, 20);
1974 SHA_Bytes(&s
, keyspace
, 20);
1975 SHA_Final(&s
, keyspace
+20);
1979 * Handle the SSH2 transport layer.
1981 static int do_ssh2_transport(unsigned char *in
, int inlen
, int ispkt
)
1985 static Bignum e
, f
, K
;
1986 static const struct ssh_mac
**maclist
;
1988 static const struct ssh_cipher
*cscipher_tobe
= NULL
;
1989 static const struct ssh_cipher
*sccipher_tobe
= NULL
;
1990 static const struct ssh_mac
*csmac_tobe
= NULL
;
1991 static const struct ssh_mac
*scmac_tobe
= NULL
;
1992 static const struct ssh_compress
*cscomp_tobe
= NULL
;
1993 static const struct ssh_compress
*sccomp_tobe
= NULL
;
1994 static char *hostkeydata
, *sigdata
, *keystr
, *fingerprint
;
1995 static int hostkeylen
, siglen
;
1996 static void *hkey
; /* actual host key */
1997 static unsigned char exchange_hash
[20];
1998 static unsigned char keyspace
[40];
1999 static const struct ssh_cipher
*preferred_cipher
;
2000 static const struct ssh_compress
*preferred_comp
;
2001 static int first_kex
;
2008 * Set up the preferred cipher and compression.
2010 if (cfg
.cipher
== CIPHER_BLOWFISH
) {
2011 preferred_cipher
= &ssh_blowfish_ssh2
;
2012 } else if (cfg
.cipher
== CIPHER_DES
) {
2013 logevent("Single DES not supported in SSH2; using 3DES");
2014 preferred_cipher
= &ssh_3des_ssh2
;
2015 } else if (cfg
.cipher
== CIPHER_3DES
) {
2016 preferred_cipher
= &ssh_3des_ssh2
;
2018 /* Shouldn't happen, but we do want to initialise to _something_. */
2019 preferred_cipher
= &ssh_3des_ssh2
;
2021 if (cfg
.compression
)
2022 preferred_comp
= &ssh_zlib
;
2024 preferred_comp
= &ssh_comp_none
;
2027 * Be prepared to work around the buggy MAC problem.
2030 maclist
= buggymacs
, nmacs
= lenof(buggymacs
);
2032 maclist
= macs
, nmacs
= lenof(macs
);
2036 * Construct and send our key exchange packet.
2038 ssh2_pkt_init(SSH2_MSG_KEXINIT
);
2039 for (i
= 0; i
< 16; i
++)
2040 ssh2_pkt_addbyte((unsigned char)random_byte());
2041 /* List key exchange algorithms. */
2042 ssh2_pkt_addstring_start();
2043 for (i
= 0; i
< lenof(kex_algs
); i
++) {
2044 ssh2_pkt_addstring_str(kex_algs
[i
]->name
);
2045 if (i
< lenof(kex_algs
)-1)
2046 ssh2_pkt_addstring_str(",");
2048 /* List server host key algorithms. */
2049 ssh2_pkt_addstring_start();
2050 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
2051 ssh2_pkt_addstring_str(hostkey_algs
[i
]->name
);
2052 if (i
< lenof(hostkey_algs
)-1)
2053 ssh2_pkt_addstring_str(",");
2055 /* List client->server encryption algorithms. */
2056 ssh2_pkt_addstring_start();
2057 for (i
= 0; i
< lenof(ciphers
)+1; i
++) {
2058 const struct ssh_cipher
*c
= i
==0 ? preferred_cipher
: ciphers
[i
-1];
2059 ssh2_pkt_addstring_str(c
->name
);
2060 if (i
< lenof(ciphers
))
2061 ssh2_pkt_addstring_str(",");
2063 /* List server->client encryption algorithms. */
2064 ssh2_pkt_addstring_start();
2065 for (i
= 0; i
< lenof(ciphers
)+1; i
++) {
2066 const struct ssh_cipher
*c
= i
==0 ? preferred_cipher
: ciphers
[i
-1];
2067 ssh2_pkt_addstring_str(c
->name
);
2068 if (i
< lenof(ciphers
))
2069 ssh2_pkt_addstring_str(",");
2071 /* List client->server MAC algorithms. */
2072 ssh2_pkt_addstring_start();
2073 for (i
= 0; i
< nmacs
; i
++) {
2074 ssh2_pkt_addstring_str(maclist
[i
]->name
);
2076 ssh2_pkt_addstring_str(",");
2078 /* List server->client MAC algorithms. */
2079 ssh2_pkt_addstring_start();
2080 for (i
= 0; i
< nmacs
; i
++) {
2081 ssh2_pkt_addstring_str(maclist
[i
]->name
);
2083 ssh2_pkt_addstring_str(",");
2085 /* List client->server compression algorithms. */
2086 ssh2_pkt_addstring_start();
2087 for (i
= 0; i
< lenof(compressions
)+1; i
++) {
2088 const struct ssh_compress
*c
= i
==0 ? preferred_comp
: compressions
[i
-1];
2089 ssh2_pkt_addstring_str(c
->name
);
2090 if (i
< lenof(compressions
))
2091 ssh2_pkt_addstring_str(",");
2093 /* List server->client compression algorithms. */
2094 ssh2_pkt_addstring_start();
2095 for (i
= 0; i
< lenof(compressions
)+1; i
++) {
2096 const struct ssh_compress
*c
= i
==0 ? preferred_comp
: compressions
[i
-1];
2097 ssh2_pkt_addstring_str(c
->name
);
2098 if (i
< lenof(compressions
))
2099 ssh2_pkt_addstring_str(",");
2101 /* List client->server languages. Empty list. */
2102 ssh2_pkt_addstring_start();
2103 /* List server->client languages. Empty list. */
2104 ssh2_pkt_addstring_start();
2105 /* First KEX packet does _not_ follow, because we're not that brave. */
2106 ssh2_pkt_addbool(FALSE
);
2108 ssh2_pkt_adduint32(0);
2110 exhash
= exhashbase
;
2111 sha_string(&exhash
, pktout
.data
+5, pktout
.length
-5);
2115 if (!ispkt
) crWaitUntil(ispkt
);
2116 sha_string(&exhash
, pktin
.data
+5, pktin
.length
-5);
2119 * Now examine the other side's KEXINIT to see what we're up
2122 if (pktin
.type
!= SSH2_MSG_KEXINIT
) {
2123 bombout(("expected key exchange packet from server"));
2126 kex
= NULL
; hostkey
= NULL
; cscipher_tobe
= NULL
; sccipher_tobe
= NULL
;
2127 csmac_tobe
= NULL
; scmac_tobe
= NULL
; cscomp_tobe
= NULL
; sccomp_tobe
= NULL
;
2128 pktin
.savedpos
+= 16; /* skip garbage cookie */
2129 ssh2_pkt_getstring(&str
, &len
); /* key exchange algorithms */
2130 for (i
= 0; i
< lenof(kex_algs
); i
++) {
2131 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
2136 ssh2_pkt_getstring(&str
, &len
); /* host key algorithms */
2137 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
2138 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
2139 hostkey
= hostkey_algs
[i
];
2143 ssh2_pkt_getstring(&str
, &len
); /* client->server cipher */
2144 for (i
= 0; i
< lenof(ciphers
)+1; i
++) {
2145 const struct ssh_cipher
*c
= i
==0 ? preferred_cipher
: ciphers
[i
-1];
2146 if (in_commasep_string(c
->name
, str
, len
)) {
2151 ssh2_pkt_getstring(&str
, &len
); /* server->client cipher */
2152 for (i
= 0; i
< lenof(ciphers
)+1; i
++) {
2153 const struct ssh_cipher
*c
= i
==0 ? preferred_cipher
: ciphers
[i
-1];
2154 if (in_commasep_string(c
->name
, str
, len
)) {
2159 ssh2_pkt_getstring(&str
, &len
); /* client->server mac */
2160 for (i
= 0; i
< nmacs
; i
++) {
2161 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
2162 csmac_tobe
= maclist
[i
];
2166 ssh2_pkt_getstring(&str
, &len
); /* server->client mac */
2167 for (i
= 0; i
< nmacs
; i
++) {
2168 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
2169 scmac_tobe
= maclist
[i
];
2173 ssh2_pkt_getstring(&str
, &len
); /* client->server compression */
2174 for (i
= 0; i
< lenof(compressions
)+1; i
++) {
2175 const struct ssh_compress
*c
= i
==0 ? preferred_comp
: compressions
[i
-1];
2176 if (in_commasep_string(c
->name
, str
, len
)) {
2181 ssh2_pkt_getstring(&str
, &len
); /* server->client compression */
2182 for (i
= 0; i
< lenof(compressions
)+1; i
++) {
2183 const struct ssh_compress
*c
= i
==0 ? preferred_comp
: compressions
[i
-1];
2184 if (in_commasep_string(c
->name
, str
, len
)) {
2191 * Currently we only support Diffie-Hellman and DSS, so let's
2192 * bomb out if those aren't selected.
2194 if (kex
!= &ssh_diffiehellman
|| hostkey
!= &ssh_dss
) {
2195 bombout(("internal fault: chaos in SSH 2 transport layer"));
2200 * Now we begin the fun. Generate and send e for Diffie-Hellman.
2203 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT
);
2208 if (pktin
.type
!= SSH2_MSG_KEXDH_REPLY
) {
2209 bombout(("expected key exchange packet from server"));
2212 ssh2_pkt_getstring(&hostkeydata
, &hostkeylen
);
2213 f
= ssh2_pkt_getmp();
2214 ssh2_pkt_getstring(&sigdata
, &siglen
);
2218 sha_string(&exhash
, hostkeydata
, hostkeylen
);
2219 sha_mpint(&exhash
, e
);
2220 sha_mpint(&exhash
, f
);
2221 sha_mpint(&exhash
, K
);
2222 SHA_Final(&exhash
, exchange_hash
);
2225 debug(("Exchange hash is:\r\n"));
2226 for (i
= 0; i
< 20; i
++)
2227 debug((" %02x", exchange_hash
[i
]));
2231 hkey
= hostkey
->newkey(hostkeydata
, hostkeylen
);
2232 if (!hostkey
->verifysig(hkey
, sigdata
, siglen
, exchange_hash
, 20)) {
2233 bombout(("Server failed host key check"));
2238 * Expect SSH2_MSG_NEWKEYS from server.
2241 if (pktin
.type
!= SSH2_MSG_NEWKEYS
) {
2242 bombout(("expected new-keys packet from server"));
2247 * Authenticate remote host: verify host key. (We've already
2248 * checked the signature of the exchange hash.)
2250 keystr
= hostkey
->fmtkey(hkey
);
2251 fingerprint
= hostkey
->fingerprint(hkey
);
2252 verify_ssh_host_key(savedhost
, savedport
, hostkey
->keytype
,
2253 keystr
, fingerprint
);
2254 logevent("Host key fingerprint is:");
2255 logevent(fingerprint
);
2258 hostkey
->freekey(hkey
);
2261 * Send SSH2_MSG_NEWKEYS.
2263 ssh2_pkt_init(SSH2_MSG_NEWKEYS
);
2267 * Create and initialise session keys.
2269 cscipher
= cscipher_tobe
;
2270 sccipher
= sccipher_tobe
;
2273 cscomp
= cscomp_tobe
;
2274 sccomp
= sccomp_tobe
;
2275 cscomp
->compress_init();
2276 sccomp
->decompress_init();
2278 * Set IVs after keys.
2280 ssh2_mkkey(K
, exchange_hash
, 'C', keyspace
); cscipher
->setcskey(keyspace
);
2281 ssh2_mkkey(K
, exchange_hash
, 'D', keyspace
); cscipher
->setsckey(keyspace
);
2282 ssh2_mkkey(K
, exchange_hash
, 'A', keyspace
); cscipher
->setcsiv(keyspace
);
2283 ssh2_mkkey(K
, exchange_hash
, 'B', keyspace
); sccipher
->setsciv(keyspace
);
2284 ssh2_mkkey(K
, exchange_hash
, 'E', keyspace
); csmac
->setcskey(keyspace
);
2285 ssh2_mkkey(K
, exchange_hash
, 'F', keyspace
); scmac
->setsckey(keyspace
);
2288 * If this is the first key exchange phase, we must pass the
2289 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
2290 * wants to see it but because it will need time to initialise
2291 * itself before it sees an actual packet. In subsequent key
2292 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
2293 * it would only confuse the layer above.
2301 * Now we're encrypting. Begin returning 1 to the protocol main
2302 * function so that other things can run on top of the
2303 * transport. If we ever see a KEXINIT, we must go back to the
2308 } while (!(ispkt
&& pktin
.type
== SSH2_MSG_KEXINIT
));
2309 goto begin_key_exchange
;
2315 * Handle the SSH2 userauth and connection layers.
2317 static void do_ssh2_authconn(unsigned char *in
, int inlen
, int ispkt
)
2319 static unsigned long remote_winsize
;
2320 static unsigned long remote_maxpkt
;
2325 * Request userauth protocol, and await a response to it.
2327 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
2328 ssh2_pkt_addstring("ssh-userauth");
2330 crWaitUntilV(ispkt
);
2331 if (pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
) {
2332 bombout(("Server refused user authentication protocol"));
2337 * FIXME: currently we support only password authentication.
2338 * (This places us technically in violation of the SSH2 spec.
2339 * We must fix this.)
2343 * Get a username and a password.
2345 static char username
[100];
2346 static char password
[100];
2350 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
2351 c_write("login as: ", 10);
2354 crWaitUntilV(!ispkt
);
2355 while (inlen
--) switch (c
= *in
++) {
2362 c_write("\b \b", 3);
2368 c_write("\b \b", 3);
2377 if (((c
>= ' ' && c
<= '~') ||
2378 ((unsigned char)c
>= 160)) && pos
< 40) {
2379 username
[pos
++] = c
;
2386 username
[strcspn(username
, "\n\r")] = '\0';
2389 strncpy(username
, cfg
.username
, 99);
2390 username
[99] = '\0';
2391 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
2392 sprintf(stuff
, "Using username \"%s\".\r\n", username
);
2393 c_write(stuff
, strlen(stuff
));
2397 if (ssh_get_password
) {
2399 sprintf(prompt
, "%.90s@%.90s's password: ", username
, savedhost
);
2400 if (!ssh_get_password(prompt
, password
, sizeof(password
))) {
2402 * get_password failed to get a password (for
2403 * example because one was supplied on the command
2404 * line which has already failed to work).
2407 logevent("No more passwords to try");
2408 ssh_state
= SSH_STATE_CLOSED
;
2412 c_write("password: ", 10);
2417 crWaitUntilV(!ispkt
);
2418 while (inlen
--) switch (c
= *in
++) {
2435 if (((c
>= ' ' && c
<= '~') ||
2436 ((unsigned char)c
>= 160)) && pos
< 40)
2437 password
[pos
++] = c
;
2444 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
2445 ssh2_pkt_addstring(username
);
2446 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2447 ssh2_pkt_addstring("password");
2448 ssh2_pkt_addbool(FALSE
);
2449 ssh2_pkt_addstring(password
);
2452 crWaitUntilV(ispkt
);
2453 if (pktin
.type
!= SSH2_MSG_USERAUTH_SUCCESS
) {
2454 c_write("Access denied\r\n", 15);
2455 logevent("Authentication refused");
2461 * Now we're authenticated for the connection protocol. The
2462 * connection protocol will automatically have started at this
2463 * point; there's no need to send SERVICE_REQUEST.
2467 * So now create a channel with a session in it.
2469 mainchan
= smalloc(sizeof(struct ssh_channel
));
2470 mainchan
->localid
= 100; /* as good as any */
2471 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
2472 ssh2_pkt_addstring("session");
2473 ssh2_pkt_adduint32(mainchan
->localid
);
2474 ssh2_pkt_adduint32(0x8000UL
); /* our window size */
2475 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
2477 crWaitUntilV(ispkt
);
2478 if (pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
2479 bombout(("Server refused to open a session"));
2481 /* FIXME: error data comes back in FAILURE packet */
2483 if (ssh2_pkt_getuint32() != mainchan
->localid
) {
2484 bombout(("Server's channel confirmation cited wrong channel"));
2487 mainchan
->remoteid
= ssh2_pkt_getuint32();
2488 mainchan
->u
.v2
.remwindow
= ssh2_pkt_getuint32();
2489 mainchan
->u
.v2
.remmaxpkt
= ssh2_pkt_getuint32();
2490 mainchan
->u
.v2
.outbuffer
= NULL
;
2491 mainchan
->u
.v2
.outbuflen
= mainchan
->u
.v2
.outbufsize
= 0;
2492 logevent("Opened channel for session");
2495 * Now allocate a pty for the session.
2498 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
2499 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
2500 ssh2_pkt_addstring("pty-req");
2501 ssh2_pkt_addbool(1); /* want reply */
2502 ssh2_pkt_addstring(cfg
.termtype
);
2503 ssh2_pkt_adduint32(cols
);
2504 ssh2_pkt_adduint32(rows
);
2505 ssh2_pkt_adduint32(0); /* pixel width */
2506 ssh2_pkt_adduint32(0); /* pixel height */
2507 ssh2_pkt_addstring_start();
2508 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
2510 ssh_state
= SSH_STATE_INTERMED
;
2513 crWaitUntilV(ispkt
);
2514 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
2515 /* FIXME: be able to handle other channels here */
2516 if (ssh2_pkt_getuint32() != mainchan
->localid
)
2517 continue; /* wrong channel */
2518 mainchan
->u
.v2
.remwindow
+= ssh2_pkt_getuint32();
2520 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
2522 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
2523 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
2524 bombout(("Server got confused by pty request"));
2527 c_write("Server refused to allocate pty\r\n", 32);
2529 logevent("Allocated pty");
2534 * Start a shell or a remote command.
2536 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
2537 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
2538 if (*cfg
.remote_cmd
) {
2539 ssh2_pkt_addstring("exec");
2540 ssh2_pkt_addbool(1); /* want reply */
2541 ssh2_pkt_addstring(cfg
.remote_cmd
);
2543 ssh2_pkt_addstring("shell");
2544 ssh2_pkt_addbool(1); /* want reply */
2548 crWaitUntilV(ispkt
);
2549 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
2550 /* FIXME: be able to handle other channels here */
2551 if (ssh2_pkt_getuint32() != mainchan
->localid
)
2552 continue; /* wrong channel */
2553 mainchan
->u
.v2
.remwindow
+= ssh2_pkt_getuint32();
2555 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
2556 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
2557 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
2558 bombout(("Server got confused by shell/command request"));
2561 bombout(("Server refused to start a shell/command"));
2564 logevent("Started a shell/command");
2567 ssh_state
= SSH_STATE_SESSION
;
2571 ssh_special(TS_EOF
);
2579 static int try_send
;
2583 if (pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
2584 pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
2587 /* FIXME: be able to handle other channels here */
2588 if (ssh2_pkt_getuint32() != mainchan
->localid
)
2589 continue; /* wrong channel */
2590 if (pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
2591 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR
)
2592 continue; /* extended but not stderr */
2593 ssh2_pkt_getstring(&data
, &length
);
2595 from_backend(pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
,
2598 * Enlarge the window again at the remote side,
2599 * just in case it ever runs down and they fail
2600 * to send us any more data.
2602 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
2603 ssh2_pkt_adduint32(mainchan
->remoteid
);
2604 ssh2_pkt_adduint32(length
);
2607 } else if (pktin
.type
== SSH2_MSG_DISCONNECT
) {
2608 ssh_state
= SSH_STATE_CLOSED
;
2609 logevent("Received disconnect message");
2611 } else if (pktin
.type
== SSH2_MSG_CHANNEL_REQUEST
) {
2612 continue; /* exit status et al; ignore (FIXME?) */
2613 } else if (pktin
.type
== SSH2_MSG_CHANNEL_EOF
) {
2614 continue; /* remote sends EOF; ignore */
2615 } else if (pktin
.type
== SSH2_MSG_CHANNEL_CLOSE
) {
2616 /* FIXME: be able to handle other channels here */
2617 if (ssh2_pkt_getuint32() != mainchan
->localid
)
2618 continue; /* wrong channel */
2619 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
2620 ssh2_pkt_adduint32(mainchan
->remoteid
);
2622 /* FIXME: mark the channel as closed */
2623 if (1 /* FIXME: "all channels are closed" */) {
2624 logevent("All channels closed. Disconnecting");
2625 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
2626 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
2627 ssh2_pkt_addstring("All open channels closed");
2628 ssh2_pkt_addstring("en"); /* language tag */
2630 ssh_state
= SSH_STATE_CLOSED
;
2633 continue; /* remote sends close; ignore (FIXME) */
2634 } else if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
2635 /* FIXME: be able to handle other channels here */
2636 if (ssh2_pkt_getuint32() != mainchan
->localid
)
2637 continue; /* wrong channel */
2638 mainchan
->u
.v2
.remwindow
+= ssh2_pkt_getuint32();
2641 bombout(("Strange packet received: type %d", pktin
.type
));
2646 * We have spare data. Add it to the channel buffer.
2648 if (mainchan
->u
.v2
.outbufsize
<
2649 mainchan
->u
.v2
.outbuflen
+ inlen
) {
2650 mainchan
->u
.v2
.outbufsize
=
2651 mainchan
->u
.v2
.outbuflen
+ inlen
+ 1024;
2652 mainchan
->u
.v2
.outbuffer
= srealloc(mainchan
->u
.v2
.outbuffer
,
2653 mainchan
->u
.v2
.outbufsize
);
2655 memcpy(mainchan
->u
.v2
.outbuffer
+ mainchan
->u
.v2
.outbuflen
,
2657 mainchan
->u
.v2
.outbuflen
+= inlen
;
2662 * Try to send data on the channel if we can. (FIXME:
2663 * on _all_ channels.)
2665 while (mainchan
->u
.v2
.remwindow
> 0 &&
2666 mainchan
->u
.v2
.outbuflen
> 0) {
2667 unsigned len
= mainchan
->u
.v2
.remwindow
;
2668 if (len
> mainchan
->u
.v2
.outbuflen
)
2669 len
= mainchan
->u
.v2
.outbuflen
;
2670 if (len
> mainchan
->u
.v2
.remmaxpkt
)
2671 len
= mainchan
->u
.v2
.remmaxpkt
;
2672 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA
);
2673 ssh2_pkt_adduint32(mainchan
->remoteid
);
2674 ssh2_pkt_addstring_start();
2675 ssh2_pkt_addstring_data(mainchan
->u
.v2
.outbuffer
, len
);
2677 mainchan
->u
.v2
.outbuflen
-= len
;
2678 memmove(mainchan
->u
.v2
.outbuffer
, mainchan
->u
.v2
.outbuffer
+len
,
2679 mainchan
->u
.v2
.outbuflen
);
2680 mainchan
->u
.v2
.remwindow
-= len
;
2689 * Handle the top-level SSH2 protocol.
2691 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
)
2693 if (do_ssh2_transport(in
, inlen
, ispkt
) == 0)
2695 do_ssh2_authconn(in
, inlen
, ispkt
);
2699 * Called to set up the connection.
2701 * Returns an error message, or NULL on success.
2703 static char *ssh_init (char *host
, int port
, char **realhost
) {
2707 if(crypto_startup() == 0)
2708 return "Microsoft high encryption pack not installed!";
2713 p
= connect_to_host(host
, port
, realhost
);
2721 * Called to send data down the Telnet connection.
2723 static void ssh_send (char *buf
, int len
) {
2724 if (s
== NULL
|| ssh_protocol
== NULL
)
2727 ssh_protocol(buf
, len
, 0);
2731 * Called to set the size of the window from SSH's POV.
2733 static void ssh_size(void) {
2734 switch (ssh_state
) {
2735 case SSH_STATE_BEFORE_SIZE
:
2736 case SSH_STATE_PREPACKET
:
2737 case SSH_STATE_CLOSED
:
2738 break; /* do nothing */
2739 case SSH_STATE_INTERMED
:
2740 size_needed
= TRUE
; /* buffer for later */
2742 case SSH_STATE_SESSION
:
2744 if (ssh_version
== 1) {
2745 send_packet(SSH1_CMSG_WINDOW_SIZE
,
2746 PKT_INT
, rows
, PKT_INT
, cols
,
2747 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
2749 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
2750 ssh2_pkt_adduint32(mainchan
->remoteid
);
2751 ssh2_pkt_addstring("window-change");
2752 ssh2_pkt_addbool(0);
2753 ssh2_pkt_adduint32(cols
);
2754 ssh2_pkt_adduint32(rows
);
2755 ssh2_pkt_adduint32(0);
2756 ssh2_pkt_adduint32(0);
2765 * Send Telnet special codes. TS_EOF is useful for `plink', so you
2766 * can send an EOF and collect resulting output (e.g. `plink
2769 static void ssh_special (Telnet_Special code
) {
2770 if (code
== TS_EOF
) {
2771 if (ssh_state
!= SSH_STATE_SESSION
) {
2773 * Buffer the EOF in case we are pre-SESSION, so we can
2774 * send it as soon as we reach SESSION.
2780 if (ssh_version
== 1) {
2781 send_packet(SSH1_CMSG_EOF
, PKT_END
);
2783 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF
);
2784 ssh2_pkt_adduint32(mainchan
->remoteid
);
2787 logevent("Sent EOF message");
2788 } else if (code
== TS_PING
) {
2789 if (ssh_state
== SSH_STATE_CLOSED
|| ssh_state
== SSH_STATE_PREPACKET
)
2791 if (ssh_version
== 1) {
2792 send_packet(SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
2794 ssh2_pkt_init(SSH2_MSG_IGNORE
);
2795 ssh2_pkt_addstring_start();
2803 static Socket
ssh_socket(void) { return s
; }
2805 static int ssh_sendok(void) { return ssh_send_ok
; }
2807 Backend ssh_backend
= {