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
;
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 */
260 SSH_STATE_BEFORE_SIZE
,
264 } ssh_state
= SSH_STATE_BEFORE_SIZE
;
266 static int size_needed
= FALSE
;
268 static struct Packet pktin
= { 0, 0, NULL
, NULL
, 0 };
269 static struct Packet pktout
= { 0, 0, NULL
, NULL
, 0 };
271 static int ssh_version
;
272 static void (*ssh_protocol
)(unsigned char *in
, int inlen
, int ispkt
);
273 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
);
274 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
);
275 static void ssh_size(void);
277 static int (*s_rdpkt
)(unsigned char **data
, int *datalen
);
279 static struct rdpkt1_state_tag
{
280 long len
, pad
, biglen
, to_read
;
281 unsigned long realcrc
, gotcrc
;
287 static struct rdpkt2_state_tag
{
288 long len
, pad
, payload
, packetlen
, maclen
;
291 unsigned long incoming_sequence
;
294 static int ssh_channelcmp(void *av
, void *bv
) {
295 struct ssh_channel
*a
= (struct ssh_channel
*)av
;
296 struct ssh_channel
*b
= (struct ssh_channel
*)bv
;
297 if (a
->localid
< b
->localid
) return -1;
298 if (a
->localid
> b
->localid
) return +1;
301 static int ssh_channelfind(void *av
, void *bv
) {
302 unsigned *a
= (unsigned *)av
;
303 struct ssh_channel
*b
= (struct ssh_channel
*)bv
;
304 if (*a
< b
->localid
) return -1;
305 if (*a
> b
->localid
) return +1;
309 static void c_write (char *buf
, int len
) {
310 if ((flags
& FLAG_STDERR
)) {
312 for (i
= 0; i
< len
; i
++)
314 fputc(buf
[i
], stderr
);
317 from_backend(1, buf
, len
);
321 * Collect incoming data in the incoming packet buffer.
322 * Decipher and verify the packet when it is completely read.
323 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
324 * Update the *data and *datalen variables.
325 * Return the additional nr of bytes needed, or 0 when
326 * a complete packet is available.
328 static int ssh1_rdpkt(unsigned char **data
, int *datalen
)
330 struct rdpkt1_state_tag
*st
= &rdpkt1_state
;
339 for (st
->i
= st
->len
= 0; st
->i
< 4; st
->i
++) {
340 while ((*datalen
) == 0)
342 st
->len
= (st
->len
<< 8) + **data
;
343 (*data
)++, (*datalen
)--;
347 if (st
->len
== 0x52656d6f) { /* "Remo"te server has closed ... */
348 st
->len
= 0x300; /* big enough to carry to end */
352 st
->pad
= 8 - (st
->len
% 8);
353 st
->biglen
= st
->len
+ st
->pad
;
354 pktin
.length
= st
->len
- 5;
356 if (pktin
.maxlen
< st
->biglen
) {
357 pktin
.maxlen
= st
->biglen
;
358 pktin
.data
= (pktin
.data
== NULL ?
smalloc(st
->biglen
+APIEXTRA
) :
359 srealloc(pktin
.data
, st
->biglen
+APIEXTRA
));
361 fatalbox("Out of memory");
364 st
->to_read
= st
->biglen
;
366 while (st
->to_read
> 0) {
367 st
->chunk
= st
->to_read
;
368 while ((*datalen
) == 0)
369 crReturn(st
->to_read
);
370 if (st
->chunk
> (*datalen
))
371 st
->chunk
= (*datalen
);
372 memcpy(st
->p
, *data
, st
->chunk
);
374 *datalen
-= st
->chunk
;
376 st
->to_read
-= st
->chunk
;
380 cipher
->decrypt(pktin
.data
, st
->biglen
);
382 debug(("Got packet len=%d pad=%d\r\n", st
->len
, st
->pad
));
383 for (st
->i
= 0; st
->i
< st
->biglen
; st
->i
++)
384 debug((" %02x", (unsigned char)pktin
.data
[st
->i
]));
388 st
->realcrc
= crc32(pktin
.data
, st
->biglen
-4);
389 st
->gotcrc
= GET_32BIT(pktin
.data
+st
->biglen
-4);
390 if (st
->gotcrc
!= st
->realcrc
) {
391 bombout(("Incorrect CRC received on packet"));
395 pktin
.body
= pktin
.data
+ st
->pad
+ 1;
397 if (ssh1_compressing
) {
398 unsigned char *decompblk
;
402 debug(("Packet payload pre-decompression:\n"));
403 for (i
= -1; i
< pktin
.length
; i
++)
404 debug((" %02x", (unsigned char)pktin
.body
[i
]));
407 zlib_decompress_block(pktin
.body
-1, pktin
.length
+1,
408 &decompblk
, &decomplen
);
410 if (pktin
.maxlen
< st
->pad
+ decomplen
) {
411 pktin
.maxlen
= st
->pad
+ decomplen
;
412 pktin
.data
= srealloc(pktin
.data
, pktin
.maxlen
+APIEXTRA
);
413 pktin
.body
= pktin
.data
+ st
->pad
+ 1;
415 fatalbox("Out of memory");
418 memcpy(pktin
.body
-1, decompblk
, decomplen
);
420 pktin
.length
= decomplen
-1;
422 debug(("Packet payload post-decompression:\n"));
423 for (i
= -1; i
< pktin
.length
; i
++)
424 debug((" %02x", (unsigned char)pktin
.body
[i
]));
429 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
430 pktin
.type
== SSH1_SMSG_STDERR_DATA
||
431 pktin
.type
== SSH1_MSG_DEBUG
||
432 pktin
.type
== SSH1_SMSG_AUTH_TIS_CHALLENGE
||
433 pktin
.type
== SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
434 long strlen
= GET_32BIT(pktin
.body
);
435 if (strlen
+ 4 != pktin
.length
) {
436 bombout(("Received data packet with bogus string length"));
441 pktin
.type
= pktin
.body
[-1];
443 if (pktin
.type
== SSH1_MSG_DEBUG
) {
444 /* log debug message */
446 int strlen
= GET_32BIT(pktin
.body
);
447 strcpy(buf
, "Remote: ");
448 if (strlen
> 70) strlen
= 70;
449 memcpy(buf
+8, pktin
.body
+4, strlen
);
450 buf
[8+strlen
] = '\0';
453 } else if (pktin
.type
== SSH1_MSG_IGNORE
) {
461 static int ssh2_rdpkt(unsigned char **data
, int *datalen
)
463 struct rdpkt2_state_tag
*st
= &rdpkt2_state
;
471 st
->cipherblk
= sccipher
->blksize
;
474 if (st
->cipherblk
< 8)
477 if (pktin
.maxlen
< st
->cipherblk
) {
478 pktin
.maxlen
= st
->cipherblk
;
479 pktin
.data
= (pktin
.data
== NULL ?
smalloc(st
->cipherblk
+APIEXTRA
) :
480 srealloc(pktin
.data
, st
->cipherblk
+APIEXTRA
));
482 fatalbox("Out of memory");
486 * Acquire and decrypt the first block of the packet. This will
487 * contain the length and padding details.
489 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
490 while ((*datalen
) == 0)
491 crReturn(st
->cipherblk
-st
->i
);
492 pktin
.data
[st
->i
] = *(*data
)++;
496 if (!memcmp(pktin
.data
, "Remo", 4)) {/* "Remo"te server has closed ... */
501 sccipher
->decrypt(pktin
.data
, st
->cipherblk
);
504 * Now get the length and padding figures.
506 st
->len
= GET_32BIT(pktin
.data
);
507 st
->pad
= pktin
.data
[4];
510 * This enables us to deduce the payload length.
512 st
->payload
= st
->len
- st
->pad
- 1;
514 pktin
.length
= st
->payload
+ 5;
517 * So now we can work out the total packet length.
519 st
->packetlen
= st
->len
+ 4;
520 st
->maclen
= scmac ? scmac
->len
: 0;
523 * Adjust memory allocation if packet is too big.
525 if (pktin
.maxlen
< st
->packetlen
+st
->maclen
) {
526 pktin
.maxlen
= st
->packetlen
+st
->maclen
;
527 pktin
.data
= (pktin
.data
== NULL ?
smalloc(pktin
.maxlen
+APIEXTRA
) :
528 srealloc(pktin
.data
, pktin
.maxlen
+APIEXTRA
));
530 fatalbox("Out of memory");
534 * Read and decrypt the remainder of the packet.
536 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
; st
->i
++) {
537 while ((*datalen
) == 0)
538 crReturn(st
->packetlen
+ st
->maclen
- st
->i
);
539 pktin
.data
[st
->i
] = *(*data
)++;
542 /* Decrypt everything _except_ the MAC. */
544 sccipher
->decrypt(pktin
.data
+ st
->cipherblk
,
545 st
->packetlen
- st
->cipherblk
);
548 debug(("Got packet len=%d pad=%d\r\n", st
->len
, st
->pad
));
549 for (st
->i
= 0; st
->i
< st
->packetlen
; st
->i
++)
550 debug((" %02x", (unsigned char)pktin
.data
[st
->i
]));
557 if (scmac
&& !scmac
->verify(pktin
.data
, st
->len
+4, st
->incoming_sequence
)) {
558 bombout(("Incorrect MAC received on packet"));
561 st
->incoming_sequence
++; /* whether or not we MACed */
564 * Decompress packet payload.
567 unsigned char *newpayload
;
569 if (sccomp
&& sccomp
->decompress(pktin
.data
+5, pktin
.length
-5,
570 &newpayload
, &newlen
)) {
571 if (pktin
.maxlen
< newlen
+5) {
572 pktin
.maxlen
= newlen
+5;
573 pktin
.data
= (pktin
.data
== NULL ?
smalloc(pktin
.maxlen
+APIEXTRA
) :
574 srealloc(pktin
.data
, pktin
.maxlen
+APIEXTRA
));
576 fatalbox("Out of memory");
578 pktin
.length
= 5 + newlen
;
579 memcpy(pktin
.data
+5, newpayload
, newlen
);
581 debug(("Post-decompression payload:\r\n"));
582 for (st
->i
= 0; st
->i
< newlen
; st
->i
++)
583 debug((" %02x", (unsigned char)pktin
.data
[5+st
->i
]));
592 pktin
.type
= pktin
.data
[5];
594 if (pktin
.type
== SSH2_MSG_IGNORE
|| pktin
.type
== SSH2_MSG_DEBUG
)
595 goto next_packet
; /* FIXME: print DEBUG message */
600 static void ssh1_pktout_size(int len
) {
603 len
+= 5; /* type and CRC */
607 pktout
.length
= len
-5;
608 if (pktout
.maxlen
< biglen
) {
609 pktout
.maxlen
= biglen
;
611 /* Allocate enough buffer space for extra block
612 * for MS CryptEncrypt() */
613 pktout
.data
= (pktout
.data
== NULL ?
smalloc(biglen
+12) :
614 srealloc(pktout
.data
, biglen
+12));
616 pktout
.data
= (pktout
.data
== NULL ?
smalloc(biglen
+4) :
617 srealloc(pktout
.data
, biglen
+4));
620 fatalbox("Out of memory");
622 pktout
.body
= pktout
.data
+4+pad
+1;
625 static void s_wrpkt_start(int type
, int len
) {
626 ssh1_pktout_size(len
);
630 static void s_wrpkt(void) {
631 int pad
, len
, biglen
, i
;
634 pktout
.body
[-1] = pktout
.type
;
636 if (ssh1_compressing
) {
637 unsigned char *compblk
;
640 debug(("Packet payload pre-compression:\n"));
641 for (i
= -1; i
< pktout
.length
; i
++)
642 debug((" %02x", (unsigned char)pktout
.body
[i
]));
645 zlib_compress_block(pktout
.body
-1, pktout
.length
+1,
647 ssh1_pktout_size(complen
-1);
648 memcpy(pktout
.body
-1, compblk
, complen
);
651 debug(("Packet payload post-compression:\n"));
652 for (i
= -1; i
< pktout
.length
; i
++)
653 debug((" %02x", (unsigned char)pktout
.body
[i
]));
658 len
= pktout
.length
+ 5; /* type and CRC */
662 for (i
=0; i
<pad
; i
++)
663 pktout
.data
[i
+4] = random_byte();
664 crc
= crc32(pktout
.data
+4, biglen
-4);
665 PUT_32BIT(pktout
.data
+biglen
, crc
);
666 PUT_32BIT(pktout
.data
, len
);
669 debug(("Sending packet len=%d\r\n", biglen
+4));
670 for (i
= 0; i
< biglen
+4; i
++)
671 debug((" %02x", (unsigned char)pktout
.data
[i
]));
675 cipher
->encrypt(pktout
.data
+4, biglen
);
677 sk_write(s
, pktout
.data
, biglen
+4);
681 * Construct a packet with the specified contents and
682 * send it to the server.
684 static void send_packet(int pkttype
, ...)
687 unsigned char *p
, *argp
, argchar
;
688 unsigned long argint
;
689 int pktlen
, argtype
, arglen
;
693 va_start(args
, pkttype
);
694 while ((argtype
= va_arg(args
, int)) != PKT_END
) {
697 (void) va_arg(args
, int);
701 (void) va_arg(args
, char);
705 (void) va_arg(args
, unsigned char *);
706 arglen
= va_arg(args
, int);
710 argp
= va_arg(args
, unsigned char *);
711 arglen
= strlen(argp
);
712 pktlen
+= 4 + arglen
;
715 bn
= va_arg(args
, Bignum
);
716 pktlen
+= ssh1_bignum_length(bn
);
724 s_wrpkt_start(pkttype
, pktlen
);
727 va_start(args
, pkttype
);
728 while ((argtype
= va_arg(args
, int)) != PKT_END
) {
731 argint
= va_arg(args
, int);
732 PUT_32BIT(p
, argint
);
736 argchar
= va_arg(args
, unsigned char);
741 argp
= va_arg(args
, unsigned char *);
742 arglen
= va_arg(args
, int);
743 memcpy(p
, argp
, arglen
);
747 argp
= va_arg(args
, unsigned char *);
748 arglen
= strlen(argp
);
749 PUT_32BIT(p
, arglen
);
750 memcpy(p
+ 4, argp
, arglen
);
754 bn
= va_arg(args
, Bignum
);
755 p
+= ssh1_write_bignum(p
, bn
);
764 static int ssh_versioncmp(char *a
, char *b
) {
766 unsigned long av
, bv
;
768 av
= strtoul(a
, &ae
, 10);
769 bv
= strtoul(b
, &be
, 10);
770 if (av
!= bv
) return (av
< bv ?
-1 : +1);
771 if (*ae
== '.') ae
++;
772 if (*be
== '.') be
++;
773 av
= strtoul(ae
, &ae
, 10);
774 bv
= strtoul(be
, &be
, 10);
775 if (av
!= bv
) return (av
< bv ?
-1 : +1);
781 * Utility routine for putting an SSH-protocol `string' into a SHA
785 static void sha_string(SHA_State
*s
, void *str
, int len
) {
786 unsigned char lenblk
[4];
787 PUT_32BIT(lenblk
, len
);
788 SHA_Bytes(s
, lenblk
, 4);
789 SHA_Bytes(s
, str
, len
);
793 * SSH2 packet construction functions.
795 static void ssh2_pkt_adddata(void *data
, int len
) {
796 pktout
.length
+= len
;
797 if (pktout
.maxlen
< pktout
.length
) {
798 pktout
.maxlen
= pktout
.length
+ 256;
799 pktout
.data
= (pktout
.data
== NULL ?
smalloc(pktout
.maxlen
+APIEXTRA
) :
800 srealloc(pktout
.data
, pktout
.maxlen
+APIEXTRA
));
802 fatalbox("Out of memory");
804 memcpy(pktout
.data
+pktout
.length
-len
, data
, len
);
806 static void ssh2_pkt_addbyte(unsigned char byte
) {
807 ssh2_pkt_adddata(&byte
, 1);
809 static void ssh2_pkt_init(int pkt_type
) {
811 ssh2_pkt_addbyte((unsigned char)pkt_type
);
813 static void ssh2_pkt_addbool(unsigned char value
) {
814 ssh2_pkt_adddata(&value
, 1);
816 static void ssh2_pkt_adduint32(unsigned long value
) {
819 ssh2_pkt_adddata(x
, 4);
821 static void ssh2_pkt_addstring_start(void) {
822 ssh2_pkt_adduint32(0);
823 pktout
.savedpos
= pktout
.length
;
825 static void ssh2_pkt_addstring_str(char *data
) {
826 ssh2_pkt_adddata(data
, strlen(data
));
827 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
828 pktout
.length
- pktout
.savedpos
);
830 static void ssh2_pkt_addstring_data(char *data
, int len
) {
831 ssh2_pkt_adddata(data
, len
);
832 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
833 pktout
.length
- pktout
.savedpos
);
835 static void ssh2_pkt_addstring(char *data
) {
836 ssh2_pkt_addstring_start();
837 ssh2_pkt_addstring_str(data
);
839 static char *ssh2_mpint_fmt(Bignum b
, int *len
) {
842 p
= smalloc(n
* 2 + 1);
844 fatalbox("out of memory");
846 for (i
= 0; i
< n
; i
++) {
847 p
[i
*2+1] = (b
[n
-i
] >> 8) & 0xFF;
848 p
[i
*2+2] = (b
[n
-i
] ) & 0xFF;
851 while (p
[i
] == 0 && (p
[i
+1] & 0x80) == 0)
853 memmove(p
, p
+i
, n
*2+1-i
);
857 static void ssh2_pkt_addmp(Bignum b
) {
860 p
= ssh2_mpint_fmt(b
, &len
);
861 ssh2_pkt_addstring_start();
862 ssh2_pkt_addstring_data(p
, len
);
865 static void ssh2_pkt_send(void) {
866 int cipherblk
, maclen
, padding
, i
;
867 static unsigned long outgoing_sequence
= 0;
870 * Compress packet payload.
873 debug(("Pre-compression payload:\r\n"));
874 for (i
= 5; i
< pktout
.length
; i
++)
875 debug((" %02x", (unsigned char)pktout
.data
[i
]));
879 unsigned char *newpayload
;
881 if (cscomp
&& cscomp
->compress(pktout
.data
+5, pktout
.length
-5,
882 &newpayload
, &newlen
)) {
884 ssh2_pkt_adddata(newpayload
, newlen
);
890 * Add padding. At least four bytes, and must also bring total
891 * length (minus MAC) up to a multiple of the block size.
893 cipherblk
= cipher ? cipher
->blksize
: 8; /* block size */
894 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
896 padding
+= (cipherblk
- (pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
897 pktout
.data
[4] = padding
;
898 for (i
= 0; i
< padding
; i
++)
899 pktout
.data
[pktout
.length
+ i
] = random_byte();
900 PUT_32BIT(pktout
.data
, pktout
.length
+ padding
- 4);
902 csmac
->generate(pktout
.data
, pktout
.length
+ padding
,
904 outgoing_sequence
++; /* whether or not we MACed */
907 debug(("Sending packet len=%d\r\n", pktout
.length
+padding
));
908 for (i
= 0; i
< pktout
.length
+padding
; i
++)
909 debug((" %02x", (unsigned char)pktout
.data
[i
]));
914 cscipher
->encrypt(pktout
.data
, pktout
.length
+ padding
);
915 maclen
= csmac ? csmac
->len
: 0;
917 sk_write(s
, pktout
.data
, pktout
.length
+ padding
+ maclen
);
921 void bndebug(char *string
, Bignum b
) {
924 p
= ssh2_mpint_fmt(b
, &len
);
925 debug(("%s", string
));
926 for (i
= 0; i
< len
; i
++)
927 debug((" %02x", p
[i
]));
933 static void sha_mpint(SHA_State
*s
, Bignum b
) {
936 p
= ssh2_mpint_fmt(b
, &len
);
937 sha_string(s
, p
, len
);
942 * SSH2 packet decode functions.
944 static unsigned long ssh2_pkt_getuint32(void) {
946 if (pktin
.length
- pktin
.savedpos
< 4)
947 return 0; /* arrgh, no way to decline (FIXME?) */
948 value
= GET_32BIT(pktin
.data
+pktin
.savedpos
);
952 static void ssh2_pkt_getstring(char **p
, int *length
) {
954 if (pktin
.length
- pktin
.savedpos
< 4)
956 *length
= GET_32BIT(pktin
.data
+pktin
.savedpos
);
958 if (pktin
.length
- pktin
.savedpos
< *length
)
960 *p
= pktin
.data
+pktin
.savedpos
;
961 pktin
.savedpos
+= *length
;
963 static Bignum
ssh2_pkt_getmp(void) {
968 ssh2_pkt_getstring(&p
, &length
);
972 bombout(("internal error: Can't handle negative mpints"));
975 b
= newbn((length
+1)/2);
976 for (i
= 0; i
< length
; i
++) {
979 b
[j
/2+1] |= ((unsigned char)p
[i
]) << 8;
981 b
[j
/2+1] |= ((unsigned char)p
[i
]);
983 while (b
[0] > 1 && b
[b
[0]] == 0) b
[0]--;
987 static int do_ssh_init(unsigned char c
) {
989 static char version
[10];
990 static char vstring
[80];
991 static char vlog
[sizeof(vstring
)+20];
996 /* Search for the string "SSH-" in the input. */
999 static const int transS
[] = { 1, 2, 2, 1 };
1000 static const int transH
[] = { 0, 0, 3, 0 };
1001 static const int transminus
[] = { 0, 0, 0, -1 };
1002 if (c
== 'S') i
= transS
[i
];
1003 else if (c
== 'H') i
= transH
[i
];
1004 else if (c
== '-') i
= transminus
[i
];
1008 crReturn(1); /* get another character */
1011 strcpy(vstring
, "SSH-");
1015 crReturn(1); /* get another char */
1016 if (vsp
< vstring
+sizeof(vstring
)-1)
1022 } else if (i
< sizeof(version
)-1)
1029 ssh_agentfwd_enabled
= FALSE
;
1030 rdpkt2_state
.incoming_sequence
= 0;
1033 sprintf(vlog
, "Server version: %s", vstring
);
1034 vlog
[strcspn(vlog
, "\r\n")] = '\0';
1038 * Server version "1.99" means we can choose whether we use v1
1039 * or v2 protocol. Choice is based on cfg.sshprot.
1041 if (ssh_versioncmp(version
, cfg
.sshprot
== 1 ?
"2.0" : "1.99") >= 0) {
1043 * This is a v2 server. Begin v2 protocol.
1045 char *verstring
= "SSH-2.0-PuTTY";
1048 * Hash our version string and their version string.
1050 sha_string(&exhash
, verstring
, strlen(verstring
));
1051 sha_string(&exhash
, vstring
, strcspn(vstring
, "\r\n"));
1052 sprintf(vstring
, "%s\n", verstring
);
1053 sprintf(vlog
, "We claim version: %s", verstring
);
1055 logevent("Using SSH protocol version 2");
1056 sk_write(s
, vstring
, strlen(vstring
));
1057 ssh_protocol
= ssh2_protocol
;
1059 s_rdpkt
= ssh2_rdpkt
;
1062 * This is a v1 server. Begin v1 protocol.
1064 sprintf(vstring
, "SSH-%s-PuTTY\n",
1065 (ssh_versioncmp(version
, "1.5") <= 0 ? version
: "1.5"));
1066 sprintf(vlog
, "We claim version: %s", vstring
);
1067 vlog
[strcspn(vlog
, "\r\n")] = '\0';
1069 logevent("Using SSH protocol version 1");
1070 sk_write(s
, vstring
, strlen(vstring
));
1071 ssh_protocol
= ssh1_protocol
;
1073 s_rdpkt
= ssh1_rdpkt
;
1079 static void ssh_gotdata(unsigned char *data
, int datalen
)
1084 * To begin with, feed the characters one by one to the
1085 * protocol initialisation / selection function do_ssh_init().
1086 * When that returns 0, we're done with the initial greeting
1087 * exchange and can move on to packet discipline.
1092 crReturnV
; /* more data please */
1093 ret
= do_ssh_init(*data
);
1100 * We emerge from that loop when the initial negotiation is
1101 * over and we have selected an s_rdpkt function. Now pass
1102 * everything to s_rdpkt, and then pass the resulting packets
1103 * to the proper protocol handler.
1108 while (datalen
> 0) {
1109 if ( s_rdpkt(&data
, &datalen
) == 0 ) {
1110 ssh_protocol(NULL
, 0, 1);
1111 if (ssh_state
== SSH_STATE_CLOSED
) {
1121 static int ssh_receive(Socket skt
, int urgent
, char *data
, int len
) {
1123 /* Connection has closed. */
1128 ssh_gotdata (data
, len
);
1129 if (ssh_state
== SSH_STATE_CLOSED
) {
1140 * Connect to specified host and port.
1141 * Returns an error message, or NULL on success.
1142 * Also places the canonical host name into `realhost'.
1144 static char *connect_to_host(char *host
, int port
, char **realhost
)
1153 savedhost
= smalloc(1+strlen(host
));
1155 fatalbox("Out of memory");
1156 strcpy(savedhost
, host
);
1159 port
= 22; /* default ssh port */
1172 addr
= sk_namelookup(host
, realhost
);
1173 if ( (err
= sk_addr_error(addr
)) )
1183 s
= sk_new(addr
, port
, ssh_receive
);
1184 if ( (err
= sk_socket_error(s
)) )
1188 sk_write(s
, "connect ", 8);
1189 sk_write(s
, FWhost
, strlen(FWhost
));
1192 sprintf(buf
, " %d\n", FWport
);
1193 sk_write(s
, buf
, strlen(buf
));
1201 * Handle the key exchange and user authentication phases.
1203 static int do_ssh1_login(unsigned char *in
, int inlen
, int ispkt
)
1206 unsigned char *rsabuf
, *keystr1
, *keystr2
;
1207 unsigned char cookie
[8];
1208 struct RSAKey servkey
, hostkey
;
1209 struct MD5Context md5c
;
1210 static unsigned long supported_ciphers_mask
, supported_auths_mask
;
1211 static int tried_publickey
;
1212 static unsigned char session_id
[16];
1214 static char username
[100];
1218 if (!ispkt
) crWaitUntil(ispkt
);
1220 if (pktin
.type
!= SSH1_SMSG_PUBLIC_KEY
) {
1221 bombout(("Public key packet not received"));
1225 logevent("Received public keys");
1227 memcpy(cookie
, pktin
.body
, 8);
1229 i
= makekey(pktin
.body
+8, &servkey
, &keystr1
, 0);
1230 j
= makekey(pktin
.body
+8+i
, &hostkey
, &keystr2
, 0);
1233 * Log the host key fingerprint.
1237 logevent("Host key fingerprint is:");
1238 strcpy(logmsg
, " ");
1239 hostkey
.comment
= NULL
;
1240 rsa_fingerprint(logmsg
+strlen(logmsg
), sizeof(logmsg
)-strlen(logmsg
),
1245 supported_ciphers_mask
= GET_32BIT(pktin
.body
+12+i
+j
);
1246 supported_auths_mask
= GET_32BIT(pktin
.body
+16+i
+j
);
1249 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
1250 MD5Update(&md5c
, keystr1
, servkey
.bytes
);
1251 MD5Update(&md5c
, pktin
.body
, 8);
1252 MD5Final(session_id
, &md5c
);
1254 for (i
=0; i
<32; i
++)
1255 session_key
[i
] = random_byte();
1257 len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
1259 rsabuf
= smalloc(len
);
1261 fatalbox("Out of memory");
1264 * Verify the host key.
1268 * First format the key into a string.
1270 int len
= rsastr_len(&hostkey
);
1271 char fingerprint
[100];
1272 char *keystr
= smalloc(len
);
1274 fatalbox("Out of memory");
1275 rsastr_fmt(keystr
, &hostkey
);
1276 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
1277 verify_ssh_host_key(savedhost
, savedport
, "rsa", keystr
, fingerprint
);
1281 for (i
=0; i
<32; i
++) {
1282 rsabuf
[i
] = session_key
[i
];
1284 rsabuf
[i
] ^= session_id
[i
];
1287 if (hostkey
.bytes
> servkey
.bytes
) {
1288 rsaencrypt(rsabuf
, 32, &servkey
);
1289 rsaencrypt(rsabuf
, servkey
.bytes
, &hostkey
);
1291 rsaencrypt(rsabuf
, 32, &hostkey
);
1292 rsaencrypt(rsabuf
, hostkey
.bytes
, &servkey
);
1295 logevent("Encrypted session key");
1297 cipher_type
= cfg
.cipher
== CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH
:
1298 cfg
.cipher
== CIPHER_DES ? SSH_CIPHER_DES
:
1300 if ((supported_ciphers_mask
& (1 << cipher_type
)) == 0) {
1301 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1302 cipher_type
= SSH_CIPHER_3DES
;
1304 switch (cipher_type
) {
1305 case SSH_CIPHER_3DES
: logevent("Using 3DES encryption"); break;
1306 case SSH_CIPHER_DES
: logevent("Using single-DES encryption"); break;
1307 case SSH_CIPHER_BLOWFISH
: logevent("Using Blowfish encryption"); break;
1310 send_packet(SSH1_CMSG_SESSION_KEY
,
1311 PKT_CHAR
, cipher_type
,
1312 PKT_DATA
, cookie
, 8,
1313 PKT_CHAR
, (len
*8) >> 8, PKT_CHAR
, (len
*8) & 0xFF,
1314 PKT_DATA
, rsabuf
, len
,
1318 logevent("Trying to enable encryption...");
1322 cipher
= cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
1323 cipher_type
== SSH_CIPHER_DES ?
&ssh_des
:
1325 cipher
->sesskey(session_key
);
1329 if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1330 bombout(("Encryption not successfully enabled"));
1334 logevent("Successfully started encryption");
1340 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
1341 c_write("login as: ", 10);
1344 crWaitUntil(!ispkt
);
1345 while (inlen
--) switch (c
= *in
++) {
1352 c_write("\b \b", 3);
1358 c_write("\b \b", 3);
1367 if (((c
>= ' ' && c
<= '~') ||
1368 ((unsigned char)c
>= 160)) && pos
< 40) {
1369 username
[pos
++] = c
;
1376 username
[strcspn(username
, "\n\r")] = '\0';
1378 strncpy(username
, cfg
.username
, 99);
1379 username
[99] = '\0';
1382 send_packet(SSH1_CMSG_USER
, PKT_STR
, username
, PKT_END
);
1384 char userlog
[22+sizeof(username
)];
1385 sprintf(userlog
, "Sent username \"%s\"", username
);
1387 if (flags
& FLAG_INTERACTIVE
&&
1388 (!((flags
& FLAG_STDERR
) && (flags
& FLAG_VERBOSE
)))) {
1389 strcat(userlog
, "\r\n");
1390 c_write(userlog
, strlen(userlog
));
1397 tried_publickey
= 0;
1399 while (pktin
.type
== SSH1_SMSG_FAILURE
) {
1400 static char password
[100];
1401 static char prompt
[200];
1404 static int pwpkt_type
;
1406 * Show password prompt, having first obtained it via a TIS
1407 * or CryptoCard exchange if we're doing TIS or CryptoCard
1410 pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
1411 if (agent_exists()) {
1413 * Attempt RSA authentication using Pageant.
1415 static unsigned char request
[5], *response
, *p
;
1416 static int responselen
;
1417 static int i
, nkeys
;
1418 static int authed
= FALSE
;
1421 logevent("Pageant is running. Requesting keys.");
1423 /* Request the keys held by the agent. */
1424 PUT_32BIT(request
, 1);
1425 request
[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES
;
1426 agent_query(request
, 5, &r
, &responselen
);
1427 response
= (unsigned char *)r
;
1430 nkeys
= GET_32BIT(p
); p
+= 4;
1431 { char buf
[64]; sprintf(buf
, "Pageant has %d keys", nkeys
);
1433 for (i
= 0; i
< nkeys
; i
++) {
1434 static struct RSAKey key
;
1435 static Bignum challenge
;
1436 static char *commentp
;
1437 static int commentlen
;
1439 { char buf
[64]; sprintf(buf
, "Trying Pageant key #%d", i
);
1442 p
+= ssh1_read_bignum(p
, &key
.exponent
);
1443 p
+= ssh1_read_bignum(p
, &key
.modulus
);
1444 commentlen
= GET_32BIT(p
); p
+= 4;
1445 commentp
= p
; p
+= commentlen
;
1446 send_packet(SSH1_CMSG_AUTH_RSA
,
1447 PKT_BIGNUM
, key
.modulus
, PKT_END
);
1449 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
1450 logevent("Key refused");
1453 logevent("Received RSA challenge");
1454 ssh1_read_bignum(pktin
.body
, &challenge
);
1456 char *agentreq
, *q
, *ret
;
1458 len
= 1 + 4; /* message type, bit count */
1459 len
+= ssh1_bignum_length(key
.exponent
);
1460 len
+= ssh1_bignum_length(key
.modulus
);
1461 len
+= ssh1_bignum_length(challenge
);
1462 len
+= 16; /* session id */
1463 len
+= 4; /* response format */
1464 agentreq
= smalloc(4 + len
);
1465 PUT_32BIT(agentreq
, len
);
1467 *q
++ = SSH_AGENTC_RSA_CHALLENGE
;
1468 PUT_32BIT(q
, ssh1_bignum_bitcount(key
.modulus
));
1470 q
+= ssh1_write_bignum(q
, key
.exponent
);
1471 q
+= ssh1_write_bignum(q
, key
.modulus
);
1472 q
+= ssh1_write_bignum(q
, challenge
);
1473 memcpy(q
, session_id
, 16); q
+= 16;
1474 PUT_32BIT(q
, 1); /* response format */
1475 agent_query(agentreq
, len
+4, &ret
, &retlen
);
1478 if (ret
[4] == SSH_AGENT_RSA_RESPONSE
) {
1479 logevent("Sending Pageant's response");
1480 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
1481 PKT_DATA
, ret
+5, 16, PKT_END
);
1484 if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
1485 logevent("Pageant's response accepted");
1486 if (flags
& FLAG_VERBOSE
) {
1487 c_write("Authenticated using RSA key \"",
1489 c_write(commentp
, commentlen
);
1490 c_write("\" from agent\r\n", 14);
1494 logevent("Pageant's response not accepted");
1496 logevent("Pageant failed to answer challenge");
1500 logevent("No reply received from Pageant");
1503 freebn(key
.exponent
);
1504 freebn(key
.modulus
);
1513 if (*cfg
.keyfile
&& !tried_publickey
)
1514 pwpkt_type
= SSH1_CMSG_AUTH_RSA
;
1516 if (pktin
.type
== SSH1_SMSG_FAILURE
&&
1518 (supported_auths_mask
& (1<<SSH1_AUTH_TIS
))) {
1519 pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
1520 logevent("Requested TIS authentication");
1521 send_packet(SSH1_CMSG_AUTH_TIS
, PKT_END
);
1523 if (pktin
.type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
1524 logevent("TIS authentication declined");
1525 if (flags
& FLAG_INTERACTIVE
)
1526 c_write("TIS authentication refused.\r\n", 29);
1528 int challengelen
= ((pktin
.body
[0] << 24) |
1529 (pktin
.body
[1] << 16) |
1530 (pktin
.body
[2] << 8) |
1532 logevent("Received TIS challenge");
1533 if (challengelen
> sizeof(prompt
)-1)
1534 challengelen
= sizeof(prompt
)-1; /* prevent overrun */
1535 memcpy(prompt
, pktin
.body
+4, challengelen
);
1536 prompt
[challengelen
] = '\0';
1539 if (pktin
.type
== SSH1_SMSG_FAILURE
&&
1541 (supported_auths_mask
& (1<<SSH1_AUTH_CCARD
))) {
1542 pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
1543 logevent("Requested CryptoCard authentication");
1544 send_packet(SSH1_CMSG_AUTH_CCARD
, PKT_END
);
1546 if (pktin
.type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
1547 logevent("CryptoCard authentication declined");
1548 c_write("CryptoCard authentication refused.\r\n", 29);
1550 int challengelen
= ((pktin
.body
[0] << 24) |
1551 (pktin
.body
[1] << 16) |
1552 (pktin
.body
[2] << 8) |
1554 logevent("Received CryptoCard challenge");
1555 if (challengelen
> sizeof(prompt
)-1)
1556 challengelen
= sizeof(prompt
)-1; /* prevent overrun */
1557 memcpy(prompt
, pktin
.body
+4, challengelen
);
1558 strncpy(prompt
+ challengelen
, "\r\nResponse : ",
1559 sizeof(prompt
)-challengelen
);
1560 prompt
[sizeof(prompt
)-1] = '\0';
1563 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
1564 sprintf(prompt
, "%.90s@%.90s's password: ",
1565 username
, savedhost
);
1567 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
1568 char *comment
= NULL
;
1569 if (flags
& FLAG_VERBOSE
)
1570 c_write("Trying public key authentication.\r\n", 35);
1571 if (!rsakey_encrypted(cfg
.keyfile
, &comment
)) {
1572 if (flags
& FLAG_VERBOSE
)
1573 c_write("No passphrase required.\r\n", 25);
1576 sprintf(prompt
, "Passphrase for key \"%.100s\": ", comment
);
1580 if (ssh_get_password
) {
1581 if (!ssh_get_password(prompt
, password
, sizeof(password
))) {
1583 * get_password failed to get a password (for
1584 * example because one was supplied on the command
1585 * line which has already failed to work).
1588 logevent("No more passwords to try");
1589 ssh_state
= SSH_STATE_CLOSED
;
1593 c_write(prompt
, strlen(prompt
));
1597 crWaitUntil(!ispkt
);
1598 while (inlen
--) switch (c
= *in
++) {
1615 if (((c
>= ' ' && c
<= '~') ||
1616 ((unsigned char)c
>= 160)) && pos
< sizeof(password
))
1617 password
[pos
++] = c
;
1625 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
1627 * Try public key authentication with the specified
1630 static struct RSAKey pubkey
;
1631 static Bignum challenge
, response
;
1633 static unsigned char buffer
[32];
1635 tried_publickey
= 1;
1636 i
= loadrsakey(cfg
.keyfile
, &pubkey
, NULL
, password
);
1638 c_write("Couldn't load public key from ", 30);
1639 c_write(cfg
.keyfile
, strlen(cfg
.keyfile
));
1640 c_write(".\r\n", 3);
1641 continue; /* go and try password */
1644 c_write("Wrong passphrase.\r\n", 19);
1645 tried_publickey
= 0;
1646 continue; /* try again */
1650 * Send a public key attempt.
1652 send_packet(SSH1_CMSG_AUTH_RSA
,
1653 PKT_BIGNUM
, pubkey
.modulus
, PKT_END
);
1656 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1657 c_write("Server refused our public key.\r\n", 32);
1658 continue; /* go and try password */
1660 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
1661 bombout(("Bizarre response to offer of public key"));
1664 ssh1_read_bignum(pktin
.body
, &challenge
);
1665 response
= rsadecrypt(challenge
, &pubkey
);
1666 freebn(pubkey
.private_exponent
); /* burn the evidence */
1668 for (i
= 0; i
< 32; i
+= 2) {
1669 buffer
[i
] = response
[16-i
/2] >> 8;
1670 buffer
[i
+1] = response
[16-i
/2] & 0xFF;
1674 MD5Update(&md5c
, buffer
, 32);
1675 MD5Update(&md5c
, session_id
, 16);
1676 MD5Final(buffer
, &md5c
);
1678 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
1679 PKT_DATA
, buffer
, 16, PKT_END
);
1682 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1683 if (flags
& FLAG_VERBOSE
)
1684 c_write("Failed to authenticate with our public key.\r\n",
1686 continue; /* go and try password */
1687 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1688 bombout(("Bizarre response to RSA authentication response"));
1692 break; /* we're through! */
1694 send_packet(pwpkt_type
, PKT_STR
, password
, PKT_END
);
1696 logevent("Sent password");
1697 memset(password
, 0, strlen(password
));
1699 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1700 if (flags
& FLAG_VERBOSE
)
1701 c_write("Access denied\r\n", 15);
1702 logevent("Authentication refused");
1703 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
1704 logevent("Received disconnect request");
1705 ssh_state
= SSH_STATE_CLOSED
;
1707 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1708 bombout(("Strange packet received, type %d", pktin
.type
));
1713 logevent("Authentication successful");
1718 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
) {
1723 while (!do_ssh1_login(in
, inlen
, ispkt
)) {
1726 if (ssh_state
== SSH_STATE_CLOSED
)
1729 if (cfg
.agentfwd
&& agent_exists()) {
1730 logevent("Requesting agent forwarding");
1731 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
1732 do { crReturnV
; } while (!ispkt
);
1733 if (pktin
.type
!= SSH1_SMSG_SUCCESS
&& pktin
.type
!= SSH1_SMSG_FAILURE
) {
1734 bombout(("Protocol confusion"));
1736 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1737 logevent("Agent forwarding refused");
1739 logevent("Agent forwarding enabled");
1740 ssh_agentfwd_enabled
= TRUE
;
1745 send_packet(SSH1_CMSG_REQUEST_PTY
,
1746 PKT_STR
, cfg
.termtype
,
1747 PKT_INT
, rows
, PKT_INT
, cols
,
1748 PKT_INT
, 0, PKT_INT
, 0,
1751 ssh_state
= SSH_STATE_INTERMED
;
1752 do { crReturnV
; } while (!ispkt
);
1753 if (pktin
.type
!= SSH1_SMSG_SUCCESS
&& pktin
.type
!= SSH1_SMSG_FAILURE
) {
1754 bombout(("Protocol confusion"));
1756 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1757 c_write("Server refused to allocate pty\r\n", 32);
1759 logevent("Allocated pty");
1762 if (cfg
.compression
) {
1763 send_packet(SSH1_CMSG_REQUEST_COMPRESSION
, PKT_INT
, 6, PKT_END
);
1764 do { crReturnV
; } while (!ispkt
);
1765 if (pktin
.type
!= SSH1_SMSG_SUCCESS
&& pktin
.type
!= SSH1_SMSG_FAILURE
) {
1766 bombout(("Protocol confusion"));
1768 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1769 c_write("Server refused to compress\r\n", 32);
1771 logevent("Started compression");
1772 ssh1_compressing
= TRUE
;
1773 zlib_compress_init();
1774 zlib_decompress_init();
1777 if (*cfg
.remote_cmd
)
1778 send_packet(SSH1_CMSG_EXEC_CMD
, PKT_STR
, cfg
.remote_cmd
, PKT_END
);
1780 send_packet(SSH1_CMSG_EXEC_SHELL
, PKT_END
);
1781 logevent("Started session");
1783 ssh_state
= SSH_STATE_SESSION
;
1788 ssh_channels
= newtree234(ssh_channelcmp
);
1793 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
1794 pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
1795 long len
= GET_32BIT(pktin
.body
);
1796 from_backend(pktin
.type
== SSH1_SMSG_STDERR_DATA
,
1798 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
1799 ssh_state
= SSH_STATE_CLOSED
;
1800 logevent("Received disconnect request");
1802 } else if (pktin
.type
== SSH1_SMSG_AGENT_OPEN
) {
1803 /* Remote side is trying to open a channel to talk to our
1804 * agent. Give them back a local channel number. */
1806 struct ssh_channel
*c
;
1809 /* Refuse if agent forwarding is disabled. */
1810 if (!ssh_agentfwd_enabled
) {
1811 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
1812 PKT_INT
, GET_32BIT(pktin
.body
),
1816 for (c
= first234(ssh_channels
, &e
); c
; c
= next234(&e
)) {
1818 break; /* found a free number */
1821 c
= smalloc(sizeof(struct ssh_channel
));
1822 c
->remoteid
= GET_32BIT(pktin
.body
);
1825 c
->type
= SSH1_SMSG_AGENT_OPEN
;/* identify channel type */
1826 c
->u
.a
.lensofar
= 0;
1827 add234(ssh_channels
, c
);
1828 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
1829 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
1832 } else if (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE
||
1833 pktin
.type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
) {
1834 /* Remote side closes a channel. */
1835 unsigned i
= GET_32BIT(pktin
.body
);
1836 struct ssh_channel
*c
;
1837 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
1840 closetype
= (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
1 : 2);
1841 send_packet(pktin
.type
, PKT_INT
, c
->remoteid
, PKT_END
);
1842 c
->closes
|= closetype
;
1843 if (c
->closes
== 3) {
1844 del234(ssh_channels
, c
);
1848 } else if (pktin
.type
== SSH1_MSG_CHANNEL_DATA
) {
1849 /* Data sent down one of our channels. */
1850 int i
= GET_32BIT(pktin
.body
);
1851 int len
= GET_32BIT(pktin
.body
+4);
1852 unsigned char *p
= pktin
.body
+8;
1853 struct ssh_channel
*c
;
1854 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
1857 case SSH1_SMSG_AGENT_OPEN
:
1858 /* Data for an agent message. Buffer it. */
1860 if (c
->u
.a
.lensofar
< 4) {
1861 int l
= min(4 - c
->u
.a
.lensofar
, len
);
1862 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
, l
);
1863 p
+= l
; len
-= l
; c
->u
.a
.lensofar
+= l
;
1865 if (c
->u
.a
.lensofar
== 4) {
1866 c
->u
.a
.totallen
= 4 + GET_32BIT(c
->u
.a
.msglen
);
1867 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
1868 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
1870 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
1871 int l
= min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
, len
);
1872 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
, l
);
1873 p
+= l
; len
-= l
; c
->u
.a
.lensofar
+= l
;
1875 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
1876 void *reply
, *sentreply
;
1878 agent_query(c
->u
.a
.message
, c
->u
.a
.totallen
,
1883 /* Fake SSH_AGENT_FAILURE. */
1884 sentreply
= "\0\0\0\1\5";
1887 send_packet(SSH1_MSG_CHANNEL_DATA
,
1888 PKT_INT
, c
->remoteid
,
1890 PKT_DATA
, sentreply
, replylen
,
1894 sfree(c
->u
.a
.message
);
1895 c
->u
.a
.lensofar
= 0;
1901 } else if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
1902 /* may be from EXEC_SHELL on some servers */
1903 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1904 /* may be from EXEC_SHELL on some servers
1905 * if no pty is available or in other odd cases. Ignore */
1906 } else if (pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
1907 send_packet(SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
1909 bombout(("Strange packet received: type %d", pktin
.type
));
1914 int len
= min(inlen
, 512);
1915 send_packet(SSH1_CMSG_STDIN_DATA
,
1916 PKT_INT
, len
, PKT_DATA
, in
, len
, PKT_END
);
1927 * Utility routine for decoding comma-separated strings in KEXINIT.
1929 static int in_commasep_string(char *needle
, char *haystack
, int haylen
) {
1930 int needlen
= strlen(needle
);
1933 * Is it at the start of the string?
1935 if (haylen
>= needlen
&& /* haystack is long enough */
1936 !memcmp(needle
, haystack
, needlen
) && /* initial match */
1937 (haylen
== needlen
|| haystack
[needlen
] == ',')
1938 /* either , or EOS follows */
1942 * If not, search for the next comma and resume after that.
1943 * If no comma found, terminate.
1945 while (haylen
> 0 && *haystack
!= ',')
1946 haylen
--, haystack
++;
1949 haylen
--, haystack
++; /* skip over comma itself */
1954 * SSH2 key creation method.
1956 static void ssh2_mkkey(Bignum K
, char *H
, char chr
, char *keyspace
) {
1958 /* First 20 bytes. */
1961 SHA_Bytes(&s
, H
, 20);
1962 SHA_Bytes(&s
, &chr
, 1);
1963 SHA_Bytes(&s
, H
, 20);
1964 SHA_Final(&s
, keyspace
);
1965 /* Next 20 bytes. */
1968 SHA_Bytes(&s
, H
, 20);
1969 SHA_Bytes(&s
, keyspace
, 20);
1970 SHA_Final(&s
, keyspace
+20);
1974 * Handle the SSH2 transport layer.
1976 static int do_ssh2_transport(unsigned char *in
, int inlen
, int ispkt
)
1980 static Bignum e
, f
, K
;
1981 static const struct ssh_mac
**maclist
;
1983 static const struct ssh_cipher
*cscipher_tobe
= NULL
;
1984 static const struct ssh_cipher
*sccipher_tobe
= NULL
;
1985 static const struct ssh_mac
*csmac_tobe
= NULL
;
1986 static const struct ssh_mac
*scmac_tobe
= NULL
;
1987 static const struct ssh_compress
*cscomp_tobe
= NULL
;
1988 static const struct ssh_compress
*sccomp_tobe
= NULL
;
1989 static char *hostkeydata
, *sigdata
, *keystr
, *fingerprint
;
1990 static int hostkeylen
, siglen
;
1991 static void *hkey
; /* actual host key */
1992 static unsigned char exchange_hash
[20];
1993 static unsigned char keyspace
[40];
1994 static const struct ssh_cipher
*preferred_cipher
;
1995 static const struct ssh_compress
*preferred_comp
;
2001 * Set up the preferred cipher and compression.
2003 if (cfg
.cipher
== CIPHER_BLOWFISH
) {
2004 preferred_cipher
= &ssh_blowfish_ssh2
;
2005 } else if (cfg
.cipher
== CIPHER_DES
) {
2006 logevent("Single DES not supported in SSH2; using 3DES");
2007 preferred_cipher
= &ssh_3des_ssh2
;
2008 } else if (cfg
.cipher
== CIPHER_3DES
) {
2009 preferred_cipher
= &ssh_3des_ssh2
;
2011 /* Shouldn't happen, but we do want to initialise to _something_. */
2012 preferred_cipher
= &ssh_3des_ssh2
;
2014 if (cfg
.compression
)
2015 preferred_comp
= &ssh_zlib
;
2017 preferred_comp
= &ssh_comp_none
;
2020 * Be prepared to work around the buggy MAC problem.
2023 maclist
= buggymacs
, nmacs
= lenof(buggymacs
);
2025 maclist
= macs
, nmacs
= lenof(macs
);
2029 * Construct and send our key exchange packet.
2031 ssh2_pkt_init(SSH2_MSG_KEXINIT
);
2032 for (i
= 0; i
< 16; i
++)
2033 ssh2_pkt_addbyte((unsigned char)random_byte());
2034 /* List key exchange algorithms. */
2035 ssh2_pkt_addstring_start();
2036 for (i
= 0; i
< lenof(kex_algs
); i
++) {
2037 ssh2_pkt_addstring_str(kex_algs
[i
]->name
);
2038 if (i
< lenof(kex_algs
)-1)
2039 ssh2_pkt_addstring_str(",");
2041 /* List server host key algorithms. */
2042 ssh2_pkt_addstring_start();
2043 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
2044 ssh2_pkt_addstring_str(hostkey_algs
[i
]->name
);
2045 if (i
< lenof(hostkey_algs
)-1)
2046 ssh2_pkt_addstring_str(",");
2048 /* List client->server encryption algorithms. */
2049 ssh2_pkt_addstring_start();
2050 for (i
= 0; i
< lenof(ciphers
)+1; i
++) {
2051 const struct ssh_cipher
*c
= i
==0 ? preferred_cipher
: ciphers
[i
-1];
2052 ssh2_pkt_addstring_str(c
->name
);
2053 if (i
< lenof(ciphers
))
2054 ssh2_pkt_addstring_str(",");
2056 /* List server->client encryption algorithms. */
2057 ssh2_pkt_addstring_start();
2058 for (i
= 0; i
< lenof(ciphers
)+1; i
++) {
2059 const struct ssh_cipher
*c
= i
==0 ? preferred_cipher
: ciphers
[i
-1];
2060 ssh2_pkt_addstring_str(c
->name
);
2061 if (i
< lenof(ciphers
))
2062 ssh2_pkt_addstring_str(",");
2064 /* List client->server MAC algorithms. */
2065 ssh2_pkt_addstring_start();
2066 for (i
= 0; i
< nmacs
; i
++) {
2067 ssh2_pkt_addstring_str(maclist
[i
]->name
);
2069 ssh2_pkt_addstring_str(",");
2071 /* List server->client 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 client->server compression algorithms. */
2079 ssh2_pkt_addstring_start();
2080 for (i
= 0; i
< lenof(compressions
)+1; i
++) {
2081 const struct ssh_compress
*c
= i
==0 ? preferred_comp
: compressions
[i
-1];
2082 ssh2_pkt_addstring_str(c
->name
);
2083 if (i
< lenof(compressions
))
2084 ssh2_pkt_addstring_str(",");
2086 /* List server->client compression algorithms. */
2087 ssh2_pkt_addstring_start();
2088 for (i
= 0; i
< lenof(compressions
)+1; i
++) {
2089 const struct ssh_compress
*c
= i
==0 ? preferred_comp
: compressions
[i
-1];
2090 ssh2_pkt_addstring_str(c
->name
);
2091 if (i
< lenof(compressions
))
2092 ssh2_pkt_addstring_str(",");
2094 /* List client->server languages. Empty list. */
2095 ssh2_pkt_addstring_start();
2096 /* List server->client languages. Empty list. */
2097 ssh2_pkt_addstring_start();
2098 /* First KEX packet does _not_ follow, because we're not that brave. */
2099 ssh2_pkt_addbool(FALSE
);
2101 ssh2_pkt_adduint32(0);
2102 sha_string(&exhash
, pktout
.data
+5, pktout
.length
-5);
2105 if (!ispkt
) crWaitUntil(ispkt
);
2106 sha_string(&exhash
, pktin
.data
+5, pktin
.length
-5);
2109 * Now examine the other side's KEXINIT to see what we're up
2112 if (pktin
.type
!= SSH2_MSG_KEXINIT
) {
2113 bombout(("expected key exchange packet from server"));
2116 kex
= NULL
; hostkey
= NULL
; cscipher_tobe
= NULL
; sccipher_tobe
= NULL
;
2117 csmac_tobe
= NULL
; scmac_tobe
= NULL
; cscomp_tobe
= NULL
; sccomp_tobe
= NULL
;
2118 pktin
.savedpos
+= 16; /* skip garbage cookie */
2119 ssh2_pkt_getstring(&str
, &len
); /* key exchange algorithms */
2120 for (i
= 0; i
< lenof(kex_algs
); i
++) {
2121 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
2126 ssh2_pkt_getstring(&str
, &len
); /* host key algorithms */
2127 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
2128 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
2129 hostkey
= hostkey_algs
[i
];
2133 ssh2_pkt_getstring(&str
, &len
); /* client->server cipher */
2134 for (i
= 0; i
< lenof(ciphers
)+1; i
++) {
2135 const struct ssh_cipher
*c
= i
==0 ? preferred_cipher
: ciphers
[i
-1];
2136 if (in_commasep_string(c
->name
, str
, len
)) {
2141 ssh2_pkt_getstring(&str
, &len
); /* server->client cipher */
2142 for (i
= 0; i
< lenof(ciphers
)+1; i
++) {
2143 const struct ssh_cipher
*c
= i
==0 ? preferred_cipher
: ciphers
[i
-1];
2144 if (in_commasep_string(c
->name
, str
, len
)) {
2149 ssh2_pkt_getstring(&str
, &len
); /* client->server mac */
2150 for (i
= 0; i
< nmacs
; i
++) {
2151 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
2152 csmac_tobe
= maclist
[i
];
2156 ssh2_pkt_getstring(&str
, &len
); /* server->client mac */
2157 for (i
= 0; i
< nmacs
; i
++) {
2158 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
2159 scmac_tobe
= maclist
[i
];
2163 ssh2_pkt_getstring(&str
, &len
); /* client->server compression */
2164 for (i
= 0; i
< lenof(compressions
)+1; i
++) {
2165 const struct ssh_compress
*c
= i
==0 ? preferred_comp
: compressions
[i
-1];
2166 if (in_commasep_string(c
->name
, str
, len
)) {
2171 ssh2_pkt_getstring(&str
, &len
); /* server->client compression */
2172 for (i
= 0; i
< lenof(compressions
)+1; i
++) {
2173 const struct ssh_compress
*c
= i
==0 ? preferred_comp
: compressions
[i
-1];
2174 if (in_commasep_string(c
->name
, str
, len
)) {
2181 * Currently we only support Diffie-Hellman and DSS, so let's
2182 * bomb out if those aren't selected.
2184 if (kex
!= &ssh_diffiehellman
|| hostkey
!= &ssh_dss
) {
2185 bombout(("internal fault: chaos in SSH 2 transport layer"));
2190 * Now we begin the fun. Generate and send e for Diffie-Hellman.
2193 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT
);
2198 if (pktin
.type
!= SSH2_MSG_KEXDH_REPLY
) {
2199 bombout(("expected key exchange packet from server"));
2202 ssh2_pkt_getstring(&hostkeydata
, &hostkeylen
);
2203 f
= ssh2_pkt_getmp();
2204 ssh2_pkt_getstring(&sigdata
, &siglen
);
2208 sha_string(&exhash
, hostkeydata
, hostkeylen
);
2209 sha_mpint(&exhash
, e
);
2210 sha_mpint(&exhash
, f
);
2211 sha_mpint(&exhash
, K
);
2212 SHA_Final(&exhash
, exchange_hash
);
2215 debug(("Exchange hash is:\r\n"));
2216 for (i
= 0; i
< 20; i
++)
2217 debug((" %02x", exchange_hash
[i
]));
2221 hkey
= hostkey
->newkey(hostkeydata
, hostkeylen
);
2222 if (!hostkey
->verifysig(hkey
, sigdata
, siglen
, exchange_hash
, 20)) {
2223 bombout(("Server failed host key check"));
2228 * Expect SSH2_MSG_NEWKEYS from server.
2231 if (pktin
.type
!= SSH2_MSG_NEWKEYS
) {
2232 bombout(("expected new-keys packet from server"));
2237 * Authenticate remote host: verify host key. (We've already
2238 * checked the signature of the exchange hash.)
2240 keystr
= hostkey
->fmtkey(hkey
);
2241 fingerprint
= hostkey
->fingerprint(hkey
);
2242 verify_ssh_host_key(savedhost
, savedport
, hostkey
->keytype
,
2243 keystr
, fingerprint
);
2244 logevent("Host key fingerprint is:");
2245 logevent(fingerprint
);
2248 hostkey
->freekey(hkey
);
2251 * Send SSH2_MSG_NEWKEYS.
2253 ssh2_pkt_init(SSH2_MSG_NEWKEYS
);
2257 * Create and initialise session keys.
2259 cscipher
= cscipher_tobe
;
2260 sccipher
= sccipher_tobe
;
2263 cscomp
= cscomp_tobe
;
2264 sccomp
= sccomp_tobe
;
2265 cscomp
->compress_init();
2266 sccomp
->decompress_init();
2268 * Set IVs after keys.
2270 ssh2_mkkey(K
, exchange_hash
, 'C', keyspace
); cscipher
->setcskey(keyspace
);
2271 ssh2_mkkey(K
, exchange_hash
, 'D', keyspace
); cscipher
->setsckey(keyspace
);
2272 ssh2_mkkey(K
, exchange_hash
, 'A', keyspace
); cscipher
->setcsiv(keyspace
);
2273 ssh2_mkkey(K
, exchange_hash
, 'B', keyspace
); sccipher
->setsciv(keyspace
);
2274 ssh2_mkkey(K
, exchange_hash
, 'E', keyspace
); csmac
->setcskey(keyspace
);
2275 ssh2_mkkey(K
, exchange_hash
, 'F', keyspace
); scmac
->setsckey(keyspace
);
2278 * Now we're encrypting. Begin returning 1 to the protocol main
2279 * function so that other things can run on top of the
2280 * transport. If we ever see a KEXINIT, we must go back to the
2285 } while (!(ispkt
&& pktin
.type
== SSH2_MSG_KEXINIT
));
2286 goto begin_key_exchange
;
2292 * Handle the SSH2 userauth and connection layers.
2294 static void do_ssh2_authconn(unsigned char *in
, int inlen
, int ispkt
)
2296 static unsigned long remote_winsize
;
2297 static unsigned long remote_maxpkt
;
2302 * Request userauth protocol, and await a response to it.
2304 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
2305 ssh2_pkt_addstring("ssh-userauth");
2307 crWaitUntilV(ispkt
);
2308 if (pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
) {
2309 bombout(("Server refused user authentication protocol"));
2314 * FIXME: currently we support only password authentication.
2315 * (This places us technically in violation of the SSH2 spec.
2316 * We must fix this.)
2320 * Get a username and a password.
2322 static char username
[100];
2323 static char password
[100];
2327 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
2328 c_write("login as: ", 10);
2331 crWaitUntilV(!ispkt
);
2332 while (inlen
--) switch (c
= *in
++) {
2339 c_write("\b \b", 3);
2345 c_write("\b \b", 3);
2354 if (((c
>= ' ' && c
<= '~') ||
2355 ((unsigned char)c
>= 160)) && pos
< 40) {
2356 username
[pos
++] = c
;
2363 username
[strcspn(username
, "\n\r")] = '\0';
2366 strncpy(username
, cfg
.username
, 99);
2367 username
[99] = '\0';
2368 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
2369 sprintf(stuff
, "Using username \"%s\".\r\n", username
);
2370 c_write(stuff
, strlen(stuff
));
2374 if (ssh_get_password
) {
2376 sprintf(prompt
, "%.90s@%.90s's password: ", username
, savedhost
);
2377 if (!ssh_get_password(prompt
, password
, sizeof(password
))) {
2379 * get_password failed to get a password (for
2380 * example because one was supplied on the command
2381 * line which has already failed to work).
2384 logevent("No more passwords to try");
2385 ssh_state
= SSH_STATE_CLOSED
;
2389 c_write("password: ", 10);
2394 crWaitUntilV(!ispkt
);
2395 while (inlen
--) switch (c
= *in
++) {
2412 if (((c
>= ' ' && c
<= '~') ||
2413 ((unsigned char)c
>= 160)) && pos
< 40)
2414 password
[pos
++] = c
;
2421 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
2422 ssh2_pkt_addstring(username
);
2423 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2424 ssh2_pkt_addstring("password");
2425 ssh2_pkt_addbool(FALSE
);
2426 ssh2_pkt_addstring(password
);
2429 crWaitUntilV(ispkt
);
2430 if (pktin
.type
!= SSH2_MSG_USERAUTH_SUCCESS
) {
2431 c_write("Access denied\r\n", 15);
2432 logevent("Authentication refused");
2438 * Now we're authenticated for the connection protocol. The
2439 * connection protocol will automatically have started at this
2440 * point; there's no need to send SERVICE_REQUEST.
2444 * So now create a channel with a session in it.
2446 mainchan
= smalloc(sizeof(struct ssh_channel
));
2447 mainchan
->localid
= 100; /* as good as any */
2448 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
2449 ssh2_pkt_addstring("session");
2450 ssh2_pkt_adduint32(mainchan
->localid
);
2451 ssh2_pkt_adduint32(0x8000UL
); /* our window size */
2452 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
2454 crWaitUntilV(ispkt
);
2455 if (pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
2456 bombout(("Server refused to open a session"));
2458 /* FIXME: error data comes back in FAILURE packet */
2460 if (ssh2_pkt_getuint32() != mainchan
->localid
) {
2461 bombout(("Server's channel confirmation cited wrong channel"));
2464 mainchan
->remoteid
= ssh2_pkt_getuint32();
2465 mainchan
->u
.v2
.remwindow
= ssh2_pkt_getuint32();
2466 mainchan
->u
.v2
.remmaxpkt
= ssh2_pkt_getuint32();
2467 mainchan
->u
.v2
.outbuffer
= NULL
;
2468 mainchan
->u
.v2
.outbuflen
= mainchan
->u
.v2
.outbufsize
= 0;
2469 logevent("Opened channel for session");
2472 * Now allocate a pty for the session.
2475 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
2476 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
2477 ssh2_pkt_addstring("pty-req");
2478 ssh2_pkt_addbool(1); /* want reply */
2479 ssh2_pkt_addstring(cfg
.termtype
);
2480 ssh2_pkt_adduint32(cols
);
2481 ssh2_pkt_adduint32(rows
);
2482 ssh2_pkt_adduint32(0); /* pixel width */
2483 ssh2_pkt_adduint32(0); /* pixel height */
2484 ssh2_pkt_addstring_start();
2485 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
2487 ssh_state
= SSH_STATE_INTERMED
;
2490 crWaitUntilV(ispkt
);
2491 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
2492 /* FIXME: be able to handle other channels here */
2493 if (ssh2_pkt_getuint32() != mainchan
->localid
)
2494 continue; /* wrong channel */
2495 mainchan
->u
.v2
.remwindow
+= ssh2_pkt_getuint32();
2497 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
2499 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
2500 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
2501 bombout(("Server got confused by pty request"));
2504 c_write("Server refused to allocate pty\r\n", 32);
2506 logevent("Allocated pty");
2511 * Start a shell or a remote command.
2513 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
2514 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
2515 if (*cfg
.remote_cmd
) {
2516 ssh2_pkt_addstring("exec");
2517 ssh2_pkt_addbool(1); /* want reply */
2518 ssh2_pkt_addstring(cfg
.remote_cmd
);
2520 ssh2_pkt_addstring("shell");
2521 ssh2_pkt_addbool(1); /* want reply */
2525 crWaitUntilV(ispkt
);
2526 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
2527 /* FIXME: be able to handle other channels here */
2528 if (ssh2_pkt_getuint32() != mainchan
->localid
)
2529 continue; /* wrong channel */
2530 mainchan
->u
.v2
.remwindow
+= ssh2_pkt_getuint32();
2532 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
2533 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
2534 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
2535 bombout(("Server got confused by shell/command request"));
2538 bombout(("Server refused to start a shell/command"));
2541 logevent("Started a shell/command");
2544 ssh_state
= SSH_STATE_SESSION
;
2554 static int try_send
;
2558 if (pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
2559 pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
2562 /* FIXME: be able to handle other channels here */
2563 if (ssh2_pkt_getuint32() != mainchan
->localid
)
2564 continue; /* wrong channel */
2565 if (pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
2566 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR
)
2567 continue; /* extended but not stderr */
2568 ssh2_pkt_getstring(&data
, &length
);
2570 from_backend(pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
,
2573 * Enlarge the window again at the remote side,
2574 * just in case it ever runs down and they fail
2575 * to send us any more data.
2577 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
2578 ssh2_pkt_adduint32(mainchan
->remoteid
);
2579 ssh2_pkt_adduint32(length
);
2582 } else if (pktin
.type
== SSH2_MSG_DISCONNECT
) {
2583 ssh_state
= SSH_STATE_CLOSED
;
2584 logevent("Received disconnect message");
2586 } else if (pktin
.type
== SSH2_MSG_CHANNEL_REQUEST
) {
2587 continue; /* exit status et al; ignore (FIXME?) */
2588 } else if (pktin
.type
== SSH2_MSG_CHANNEL_EOF
) {
2589 continue; /* remote sends EOF; ignore */
2590 } else if (pktin
.type
== SSH2_MSG_CHANNEL_CLOSE
) {
2591 /* FIXME: be able to handle other channels here */
2592 if (ssh2_pkt_getuint32() != mainchan
->localid
)
2593 continue; /* wrong channel */
2594 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
2595 ssh2_pkt_adduint32(mainchan
->remoteid
);
2597 /* FIXME: mark the channel as closed */
2598 if (1 /* FIXME: "all channels are closed" */) {
2599 logevent("All channels closed. Disconnecting");
2600 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
2601 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
2602 ssh2_pkt_addstring("All open channels closed");
2603 ssh2_pkt_addstring("en"); /* language tag */
2605 ssh_state
= SSH_STATE_CLOSED
;
2608 continue; /* remote sends close; ignore (FIXME) */
2609 } else if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
2610 /* FIXME: be able to handle other channels here */
2611 if (ssh2_pkt_getuint32() != mainchan
->localid
)
2612 continue; /* wrong channel */
2613 mainchan
->u
.v2
.remwindow
+= ssh2_pkt_getuint32();
2616 bombout(("Strange packet received: type %d", pktin
.type
));
2621 * We have spare data. Add it to the channel buffer.
2623 if (mainchan
->u
.v2
.outbufsize
<
2624 mainchan
->u
.v2
.outbuflen
+ inlen
) {
2625 mainchan
->u
.v2
.outbufsize
=
2626 mainchan
->u
.v2
.outbuflen
+ inlen
+ 1024;
2627 mainchan
->u
.v2
.outbuffer
= srealloc(mainchan
->u
.v2
.outbuffer
,
2628 mainchan
->u
.v2
.outbufsize
);
2630 memcpy(mainchan
->u
.v2
.outbuffer
+ mainchan
->u
.v2
.outbuflen
,
2632 mainchan
->u
.v2
.outbuflen
+= inlen
;
2637 * Try to send data on the channel if we can. (FIXME:
2638 * on _all_ channels.)
2640 while (mainchan
->u
.v2
.remwindow
> 0 &&
2641 mainchan
->u
.v2
.outbuflen
> 0) {
2642 unsigned len
= mainchan
->u
.v2
.remwindow
;
2643 if (len
> mainchan
->u
.v2
.outbuflen
)
2644 len
= mainchan
->u
.v2
.outbuflen
;
2645 if (len
> mainchan
->u
.v2
.remmaxpkt
)
2646 len
= mainchan
->u
.v2
.remmaxpkt
;
2647 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA
);
2648 ssh2_pkt_adduint32(mainchan
->remoteid
);
2649 ssh2_pkt_addstring_start();
2650 ssh2_pkt_addstring_data(mainchan
->u
.v2
.outbuffer
, len
);
2652 mainchan
->u
.v2
.outbuflen
-= len
;
2653 memmove(mainchan
->u
.v2
.outbuffer
, mainchan
->u
.v2
.outbuffer
+len
,
2654 mainchan
->u
.v2
.outbuflen
);
2655 mainchan
->u
.v2
.remwindow
-= len
;
2664 * Handle the top-level SSH2 protocol.
2666 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
)
2668 if (do_ssh2_transport(in
, inlen
, ispkt
) == 0)
2670 do_ssh2_authconn(in
, inlen
, ispkt
);
2674 * Called to set up the connection.
2676 * Returns an error message, or NULL on success.
2678 static char *ssh_init (char *host
, int port
, char **realhost
) {
2682 if(crypto_startup() == 0)
2683 return "Microsoft high encryption pack not installed!";
2688 p
= connect_to_host(host
, port
, realhost
);
2696 * Called to send data down the Telnet connection.
2698 static void ssh_send (char *buf
, int len
) {
2699 if (s
== NULL
|| ssh_protocol
== NULL
)
2702 ssh_protocol(buf
, len
, 0);
2706 * Called to set the size of the window from SSH's POV.
2708 static void ssh_size(void) {
2709 switch (ssh_state
) {
2710 case SSH_STATE_BEFORE_SIZE
:
2711 case SSH_STATE_CLOSED
:
2712 break; /* do nothing */
2713 case SSH_STATE_INTERMED
:
2714 size_needed
= TRUE
; /* buffer for later */
2716 case SSH_STATE_SESSION
:
2718 if (ssh_version
== 1) {
2719 send_packet(SSH1_CMSG_WINDOW_SIZE
,
2720 PKT_INT
, rows
, PKT_INT
, cols
,
2721 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
2723 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
2724 ssh2_pkt_adduint32(mainchan
->remoteid
);
2725 ssh2_pkt_addstring("window-change");
2726 ssh2_pkt_addbool(0);
2727 ssh2_pkt_adduint32(cols
);
2728 ssh2_pkt_adduint32(rows
);
2729 ssh2_pkt_adduint32(0);
2730 ssh2_pkt_adduint32(0);
2738 * Send Telnet special codes. TS_EOF is useful for `plink', so you
2739 * can send an EOF and collect resulting output (e.g. `plink
2742 static void ssh_special (Telnet_Special code
) {
2743 if (code
== TS_EOF
) {
2744 if (ssh_version
== 1) {
2745 send_packet(SSH1_CMSG_EOF
, PKT_END
);
2747 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF
);
2748 ssh2_pkt_adduint32(mainchan
->remoteid
);
2751 logevent("Sent EOF message");
2752 } else if (code
== TS_PING
) {
2753 if (ssh_version
== 1) {
2754 send_packet(SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
2756 ssh2_pkt_init(SSH2_MSG_IGNORE
);
2757 ssh2_pkt_addstring_start();
2765 static Socket
ssh_socket(void) { return s
; }
2767 static int ssh_sendok(void) { return ssh_send_ok
; }
2769 Backend ssh_backend
= {