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_AUTH_TIS 39 /* 0x27 */
55 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
56 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
57 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
58 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
59 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
61 #define SSH1_AUTH_TIS 5 /* 0x5 */
62 #define SSH1_AUTH_CCARD 16 /* 0x10 */
64 #define SSH_AGENTC_REQUEST_RSA_IDENTITIES 1 /* 0x1 */
65 #define SSH_AGENT_RSA_IDENTITIES_ANSWER 2 /* 0x2 */
66 #define SSH_AGENTC_RSA_CHALLENGE 3 /* 0x3 */
67 #define SSH_AGENT_RSA_RESPONSE 4 /* 0x4 */
68 #define SSH_AGENT_FAILURE 5 /* 0x5 */
69 #define SSH_AGENT_SUCCESS 6 /* 0x6 */
70 #define SSH_AGENTC_ADD_RSA_IDENTITY 7 /* 0x7 */
71 #define SSH_AGENTC_REMOVE_RSA_IDENTITY 8 /* 0x8 */
73 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
74 #define SSH2_MSG_IGNORE 2 /* 0x2 */
75 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
76 #define SSH2_MSG_DEBUG 4 /* 0x4 */
77 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
78 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
79 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
80 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
81 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
82 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
83 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
84 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
85 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
86 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
87 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
88 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
89 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
90 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
91 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
92 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
93 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
94 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
95 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
96 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
97 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
98 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
99 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
100 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
101 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
102 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
104 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
105 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
106 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
107 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
109 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
111 #define GET_32BIT(cp) \
112 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
113 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
114 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
115 ((unsigned long)(unsigned char)(cp)[3]))
117 #define PUT_32BIT(cp, value) { \
118 (cp)[0] = (unsigned char)((value) >> 24); \
119 (cp)[1] = (unsigned char)((value) >> 16); \
120 (cp)[2] = (unsigned char)((value) >> 8); \
121 (cp)[3] = (unsigned char)(value); }
123 enum { PKT_END
, PKT_INT
, PKT_CHAR
, PKT_DATA
, PKT_STR
, PKT_BIGNUM
};
125 /* Coroutine mechanics for the sillier bits of the code */
126 #define crBegin1 static int crLine = 0;
127 #define crBegin2 switch(crLine) { case 0:;
128 #define crBegin crBegin1; crBegin2;
129 #define crFinish(z) } crLine = 0; return (z)
130 #define crFinishV } crLine = 0; return
131 #define crReturn(z) \
133 crLine=__LINE__; return (z); case __LINE__:;\
137 crLine=__LINE__; return; case __LINE__:;\
139 #define crStop(z) do{ crLine = 0; return (z); }while(0)
140 #define crStopV do{ crLine = 0; return; }while(0)
141 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
142 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
144 extern const struct ssh_cipher ssh_3des
;
145 extern const struct ssh_cipher ssh_3des_ssh2
;
146 extern const struct ssh_cipher ssh_des
;
147 extern const struct ssh_cipher ssh_blowfish_ssh1
;
148 extern const struct ssh_cipher ssh_blowfish_ssh2
;
151 * Ciphers for SSH2. We miss out single-DES because it isn't
152 * supported; also 3DES and Blowfish are both done differently from
153 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
154 * endianness and different-sized keys.)
156 const static struct ssh_cipher
*ciphers
[] = { &ssh_blowfish_ssh2
, &ssh_3des_ssh2
};
158 extern const struct ssh_kex ssh_diffiehellman
;
159 const static struct ssh_kex
*kex_algs
[] = { &ssh_diffiehellman
};
161 extern const struct ssh_hostkey ssh_dss
;
162 const static struct ssh_hostkey
*hostkey_algs
[] = { &ssh_dss
};
164 extern const struct ssh_mac ssh_md5
, ssh_sha1
, ssh_sha1_buggy
;
166 static void nullmac_key(unsigned char *key
) { }
167 static void nullmac_generate(unsigned char *blk
, int len
, unsigned long seq
) { }
168 static int nullmac_verify(unsigned char *blk
, int len
, unsigned long seq
) { return 1; }
169 const static struct ssh_mac ssh_mac_none
= {
170 nullmac_key
, nullmac_key
, nullmac_generate
, nullmac_verify
, "none", 0
172 const static struct ssh_mac
*macs
[] = {
173 &ssh_sha1
, &ssh_md5
, &ssh_mac_none
};
174 const static struct ssh_mac
*buggymacs
[] = {
175 &ssh_sha1_buggy
, &ssh_md5
, &ssh_mac_none
};
177 const static struct ssh_compress ssh_comp_none
= {
180 const static struct ssh_compress
*compressions
[] = { &ssh_comp_none
};
183 * 2-3-4 tree storing channels.
186 unsigned remoteid
, localid
;
190 struct ssh_agent_channel
{
191 unsigned char *message
;
192 unsigned char msglen
[4];
193 int lensofar
, totallen
;
195 struct ssh2_data_channel
{
196 unsigned char *outbuffer
;
197 unsigned outbuflen
, outbufsize
;
198 unsigned remwindow
, remmaxpkt
;
212 static SHA_State exhash
;
214 static Socket s
= NULL
;
216 static unsigned char session_key
[32];
217 static const struct ssh_cipher
*cipher
= NULL
;
218 static const struct ssh_cipher
*cscipher
= NULL
;
219 static const struct ssh_cipher
*sccipher
= NULL
;
220 static const struct ssh_mac
*csmac
= NULL
;
221 static const struct ssh_mac
*scmac
= NULL
;
222 static const struct ssh_compress
*cscomp
= NULL
;
223 static const struct ssh_compress
*sccomp
= NULL
;
224 static const struct ssh_kex
*kex
= NULL
;
225 static const struct ssh_hostkey
*hostkey
= NULL
;
226 int (*ssh_get_password
)(const char *prompt
, char *str
, int maxlen
) = NULL
;
228 static char *savedhost
;
229 static int savedport
;
230 static int ssh_send_ok
;
232 static tree234
*ssh_channels
; /* indexed by local id */
233 static struct ssh_channel
*mainchan
; /* primary session channel */
236 SSH_STATE_BEFORE_SIZE
,
240 } ssh_state
= SSH_STATE_BEFORE_SIZE
;
242 static int size_needed
= FALSE
;
244 static struct Packet pktin
= { 0, 0, NULL
, NULL
, 0 };
245 static struct Packet pktout
= { 0, 0, NULL
, NULL
, 0 };
247 static int ssh_version
;
248 static void (*ssh_protocol
)(unsigned char *in
, int inlen
, int ispkt
);
249 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
);
250 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
);
251 static void ssh_size(void);
253 static int (*s_rdpkt
)(unsigned char **data
, int *datalen
);
255 static struct rdpkt1_state_tag
{
256 long len
, pad
, biglen
, to_read
;
257 unsigned long realcrc
, gotcrc
;
263 static struct rdpkt2_state_tag
{
264 long len
, pad
, payload
, packetlen
, maclen
;
267 unsigned long incoming_sequence
;
270 static int ssh_channelcmp(void *av
, void *bv
) {
271 struct ssh_channel
*a
= (struct ssh_channel
*)av
;
272 struct ssh_channel
*b
= (struct ssh_channel
*)bv
;
273 if (a
->localid
< b
->localid
) return -1;
274 if (a
->localid
> b
->localid
) return +1;
277 static int ssh_channelfind(void *av
, void *bv
) {
278 unsigned *a
= (unsigned *)av
;
279 struct ssh_channel
*b
= (struct ssh_channel
*)bv
;
280 if (*a
< b
->localid
) return -1;
281 if (*a
> b
->localid
) return +1;
285 static void c_write (char *buf
, int len
) {
286 if ((flags
& FLAG_STDERR
)) {
288 for (i
= 0; i
< len
; i
++)
290 fputc(buf
[i
], stderr
);
293 from_backend(1, buf
, len
);
297 * Collect incoming data in the incoming packet buffer.
298 * Decipher and verify the packet when it is completely read.
299 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
300 * Update the *data and *datalen variables.
301 * Return the additional nr of bytes needed, or 0 when
302 * a complete packet is available.
304 static int ssh1_rdpkt(unsigned char **data
, int *datalen
)
306 struct rdpkt1_state_tag
*st
= &rdpkt1_state
;
315 for (st
->i
= st
->len
= 0; st
->i
< 4; st
->i
++) {
316 while ((*datalen
) == 0)
318 st
->len
= (st
->len
<< 8) + **data
;
319 (*data
)++, (*datalen
)--;
323 if (st
->len
== 0x52656d6f) { /* "Remo"te server has closed ... */
324 st
->len
= 0x300; /* big enough to carry to end */
328 st
->pad
= 8 - (st
->len
% 8);
329 st
->biglen
= st
->len
+ st
->pad
;
330 pktin
.length
= st
->len
- 5;
332 if (pktin
.maxlen
< st
->biglen
) {
333 pktin
.maxlen
= st
->biglen
;
334 pktin
.data
= (pktin
.data
== NULL ?
malloc(st
->biglen
+APIEXTRA
) :
335 realloc(pktin
.data
, st
->biglen
+APIEXTRA
));
337 fatalbox("Out of memory");
340 st
->to_read
= st
->biglen
;
342 while (st
->to_read
> 0) {
343 st
->chunk
= st
->to_read
;
344 while ((*datalen
) == 0)
345 crReturn(st
->to_read
);
346 if (st
->chunk
> (*datalen
))
347 st
->chunk
= (*datalen
);
348 memcpy(st
->p
, *data
, st
->chunk
);
350 *datalen
-= st
->chunk
;
352 st
->to_read
-= st
->chunk
;
356 cipher
->decrypt(pktin
.data
, st
->biglen
);
358 debug(("Got packet len=%d pad=%d\r\n", st
->len
, st
->pad
));
359 for (st
->i
= 0; st
->i
< st
->biglen
; st
->i
++)
360 debug((" %02x", (unsigned char)pktin
.data
[st
->i
]));
364 pktin
.type
= pktin
.data
[st
->pad
];
365 pktin
.body
= pktin
.data
+ st
->pad
+ 1;
367 st
->realcrc
= crc32(pktin
.data
, st
->biglen
-4);
368 st
->gotcrc
= GET_32BIT(pktin
.data
+st
->biglen
-4);
369 if (st
->gotcrc
!= st
->realcrc
) {
370 bombout(("Incorrect CRC received on packet"));
374 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
375 pktin
.type
== SSH1_SMSG_STDERR_DATA
||
376 pktin
.type
== SSH1_MSG_DEBUG
||
377 pktin
.type
== SSH1_SMSG_AUTH_TIS_CHALLENGE
||
378 pktin
.type
== SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
379 long strlen
= GET_32BIT(pktin
.body
);
380 if (strlen
+ 4 != pktin
.length
) {
381 bombout(("Received data packet with bogus string length"));
386 if (pktin
.type
== SSH1_MSG_DEBUG
) {
387 /* log debug message */
389 int strlen
= GET_32BIT(pktin
.body
);
390 strcpy(buf
, "Remote: ");
391 if (strlen
> 70) strlen
= 70;
392 memcpy(buf
+8, pktin
.body
+4, strlen
);
393 buf
[8+strlen
] = '\0';
396 } else if (pktin
.type
== SSH1_MSG_IGNORE
) {
404 static int ssh2_rdpkt(unsigned char **data
, int *datalen
)
406 struct rdpkt2_state_tag
*st
= &rdpkt2_state
;
414 st
->cipherblk
= sccipher
->blksize
;
417 if (st
->cipherblk
< 8)
420 if (pktin
.maxlen
< st
->cipherblk
) {
421 pktin
.maxlen
= st
->cipherblk
;
422 pktin
.data
= (pktin
.data
== NULL ?
malloc(st
->cipherblk
+APIEXTRA
) :
423 realloc(pktin
.data
, st
->cipherblk
+APIEXTRA
));
425 fatalbox("Out of memory");
429 * Acquire and decrypt the first block of the packet. This will
430 * contain the length and padding details.
432 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
433 while ((*datalen
) == 0)
434 crReturn(st
->cipherblk
-st
->i
);
435 pktin
.data
[st
->i
] = *(*data
)++;
439 if (!memcmp(pktin
.data
, "Remo", 4)) {/* "Remo"te server has closed ... */
444 sccipher
->decrypt(pktin
.data
, st
->cipherblk
);
447 * Now get the length and padding figures.
449 st
->len
= GET_32BIT(pktin
.data
);
450 st
->pad
= pktin
.data
[4];
453 * This enables us to deduce the payload length.
455 st
->payload
= st
->len
- st
->pad
- 1;
457 pktin
.length
= st
->payload
+ 5;
460 * So now we can work out the total packet length.
462 st
->packetlen
= st
->len
+ 4;
463 st
->maclen
= scmac ? scmac
->len
: 0;
466 * Adjust memory allocation if packet is too big.
468 if (pktin
.maxlen
< st
->packetlen
+st
->maclen
) {
469 pktin
.maxlen
= st
->packetlen
+st
->maclen
;
470 pktin
.data
= (pktin
.data
== NULL ?
malloc(pktin
.maxlen
+APIEXTRA
) :
471 realloc(pktin
.data
, pktin
.maxlen
+APIEXTRA
));
473 fatalbox("Out of memory");
477 * Read and decrypt the remainder of the packet.
479 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
; st
->i
++) {
480 while ((*datalen
) == 0)
481 crReturn(st
->packetlen
+ st
->maclen
- st
->i
);
482 pktin
.data
[st
->i
] = *(*data
)++;
485 /* Decrypt everything _except_ the MAC. */
487 sccipher
->decrypt(pktin
.data
+ st
->cipherblk
,
488 st
->packetlen
- st
->cipherblk
);
491 debug(("Got packet len=%d pad=%d\r\n", st
->len
, st
->pad
));
492 for (st
->i
= 0; st
->i
< st
->packetlen
; st
->i
++)
493 debug((" %02x", (unsigned char)pktin
.data
[st
->i
]));
500 if (scmac
&& !scmac
->verify(pktin
.data
, st
->len
+4, st
->incoming_sequence
)) {
501 bombout(("Incorrect MAC received on packet"));
504 st
->incoming_sequence
++; /* whether or not we MACed */
507 pktin
.type
= pktin
.data
[5];
509 if (pktin
.type
== SSH2_MSG_IGNORE
|| pktin
.type
== SSH2_MSG_DEBUG
)
510 goto next_packet
; /* FIXME: print DEBUG message */
515 static void s_wrpkt_start(int type
, int len
) {
518 len
+= 5; /* type and CRC */
522 pktout
.length
= len
-5;
523 if (pktout
.maxlen
< biglen
) {
524 pktout
.maxlen
= biglen
;
526 /* Allocate enough buffer space for extra block
527 * for MS CryptEncrypt() */
528 pktout
.data
= (pktout
.data
== NULL ?
malloc(biglen
+12) :
529 realloc(pktout
.data
, biglen
+12));
531 pktout
.data
= (pktout
.data
== NULL ?
malloc(biglen
+4) :
532 realloc(pktout
.data
, biglen
+4));
535 fatalbox("Out of memory");
539 pktout
.body
= pktout
.data
+4+pad
+1;
542 static void s_wrpkt(void) {
543 int pad
, len
, biglen
, i
;
546 len
= pktout
.length
+ 5; /* type and CRC */
550 pktout
.body
[-1] = pktout
.type
;
551 for (i
=0; i
<pad
; i
++)
552 pktout
.data
[i
+4] = random_byte();
553 crc
= crc32(pktout
.data
+4, biglen
-4);
554 PUT_32BIT(pktout
.data
+biglen
, crc
);
555 PUT_32BIT(pktout
.data
, len
);
558 debug(("Sending packet len=%d\r\n", biglen
+4));
559 for (i
= 0; i
< biglen
+4; i
++)
560 debug((" %02x", (unsigned char)pktout
.data
[i
]));
564 cipher
->encrypt(pktout
.data
+4, biglen
);
566 sk_write(s
, pktout
.data
, biglen
+4);
570 * Construct a packet with the specified contents and
571 * send it to the server.
573 static void send_packet(int pkttype
, ...)
576 unsigned char *p
, *argp
, argchar
;
577 unsigned long argint
;
578 int pktlen
, argtype
, arglen
;
582 va_start(args
, pkttype
);
583 while ((argtype
= va_arg(args
, int)) != PKT_END
) {
586 (void) va_arg(args
, int);
590 (void) va_arg(args
, char);
594 (void) va_arg(args
, unsigned char *);
595 arglen
= va_arg(args
, int);
599 argp
= va_arg(args
, unsigned char *);
600 arglen
= strlen(argp
);
601 pktlen
+= 4 + arglen
;
604 bn
= va_arg(args
, Bignum
);
605 pktlen
+= ssh1_bignum_length(bn
);
613 s_wrpkt_start(pkttype
, pktlen
);
616 va_start(args
, pkttype
);
617 while ((argtype
= va_arg(args
, int)) != PKT_END
) {
620 argint
= va_arg(args
, int);
621 PUT_32BIT(p
, argint
);
625 argchar
= va_arg(args
, unsigned char);
630 argp
= va_arg(args
, unsigned char *);
631 arglen
= va_arg(args
, int);
632 memcpy(p
, argp
, arglen
);
636 argp
= va_arg(args
, unsigned char *);
637 arglen
= strlen(argp
);
638 PUT_32BIT(p
, arglen
);
639 memcpy(p
+ 4, argp
, arglen
);
643 bn
= va_arg(args
, Bignum
);
644 p
+= ssh1_write_bignum(p
, bn
);
653 static int ssh_versioncmp(char *a
, char *b
) {
655 unsigned long av
, bv
;
657 av
= strtoul(a
, &ae
, 10);
658 bv
= strtoul(b
, &be
, 10);
659 if (av
!= bv
) return (av
< bv ?
-1 : +1);
660 if (*ae
== '.') ae
++;
661 if (*be
== '.') be
++;
662 av
= strtoul(ae
, &ae
, 10);
663 bv
= strtoul(be
, &be
, 10);
664 if (av
!= bv
) return (av
< bv ?
-1 : +1);
670 * Utility routine for putting an SSH-protocol `string' into a SHA
674 static void sha_string(SHA_State
*s
, void *str
, int len
) {
675 unsigned char lenblk
[4];
676 PUT_32BIT(lenblk
, len
);
677 SHA_Bytes(s
, lenblk
, 4);
678 SHA_Bytes(s
, str
, len
);
682 * SSH2 packet construction functions.
684 static void ssh2_pkt_adddata(void *data
, int len
) {
685 pktout
.length
+= len
;
686 if (pktout
.maxlen
< pktout
.length
) {
687 pktout
.maxlen
= pktout
.length
+ 256;
688 pktout
.data
= (pktout
.data
== NULL ?
malloc(pktout
.maxlen
+APIEXTRA
) :
689 realloc(pktout
.data
, pktout
.maxlen
+APIEXTRA
));
691 fatalbox("Out of memory");
693 memcpy(pktout
.data
+pktout
.length
-len
, data
, len
);
695 static void ssh2_pkt_addbyte(unsigned char byte
) {
696 ssh2_pkt_adddata(&byte
, 1);
698 static void ssh2_pkt_init(int pkt_type
) {
700 ssh2_pkt_addbyte((unsigned char)pkt_type
);
702 static void ssh2_pkt_addbool(unsigned char value
) {
703 ssh2_pkt_adddata(&value
, 1);
705 static void ssh2_pkt_adduint32(unsigned long value
) {
708 ssh2_pkt_adddata(x
, 4);
710 static void ssh2_pkt_addstring_start(void) {
711 ssh2_pkt_adduint32(0);
712 pktout
.savedpos
= pktout
.length
;
714 static void ssh2_pkt_addstring_str(char *data
) {
715 ssh2_pkt_adddata(data
, strlen(data
));
716 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
717 pktout
.length
- pktout
.savedpos
);
719 static void ssh2_pkt_addstring_data(char *data
, int len
) {
720 ssh2_pkt_adddata(data
, len
);
721 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
722 pktout
.length
- pktout
.savedpos
);
724 static void ssh2_pkt_addstring(char *data
) {
725 ssh2_pkt_addstring_start();
726 ssh2_pkt_addstring_str(data
);
728 static char *ssh2_mpint_fmt(Bignum b
, int *len
) {
731 p
= malloc(n
* 2 + 1);
733 fatalbox("out of memory");
735 for (i
= 0; i
< n
; i
++) {
736 p
[i
*2+1] = (b
[n
-i
] >> 8) & 0xFF;
737 p
[i
*2+2] = (b
[n
-i
] ) & 0xFF;
740 while (p
[i
] == 0 && (p
[i
+1] & 0x80) == 0)
742 memmove(p
, p
+i
, n
*2+1-i
);
746 static void ssh2_pkt_addmp(Bignum b
) {
749 p
= ssh2_mpint_fmt(b
, &len
);
750 ssh2_pkt_addstring_start();
751 ssh2_pkt_addstring_data(p
, len
);
754 static void ssh2_pkt_send(void) {
755 int cipherblk
, maclen
, padding
, i
;
756 static unsigned long outgoing_sequence
= 0;
759 * Add padding. At least four bytes, and must also bring total
760 * length (minus MAC) up to a multiple of the block size.
762 cipherblk
= cipher ? cipher
->blksize
: 8; /* block size */
763 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
765 padding
+= (cipherblk
- (pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
766 pktout
.data
[4] = padding
;
767 for (i
= 0; i
< padding
; i
++)
768 pktout
.data
[pktout
.length
+ i
] = random_byte();
769 PUT_32BIT(pktout
.data
, pktout
.length
+ padding
- 4);
771 csmac
->generate(pktout
.data
, pktout
.length
+ padding
,
773 outgoing_sequence
++; /* whether or not we MACed */
776 debug(("Sending packet len=%d\r\n", pktout
.length
+padding
));
777 for (i
= 0; i
< pktout
.length
+padding
; i
++)
778 debug((" %02x", (unsigned char)pktout
.data
[i
]));
783 cscipher
->encrypt(pktout
.data
, pktout
.length
+ padding
);
784 maclen
= csmac ? csmac
->len
: 0;
786 sk_write(s
, pktout
.data
, pktout
.length
+ padding
+ maclen
);
790 void bndebug(char *string
, Bignum b
) {
793 p
= ssh2_mpint_fmt(b
, &len
);
794 debug(("%s", string
));
795 for (i
= 0; i
< len
; i
++)
796 debug((" %02x", p
[i
]));
802 static void sha_mpint(SHA_State
*s
, Bignum b
) {
805 p
= ssh2_mpint_fmt(b
, &len
);
806 sha_string(s
, p
, len
);
811 * SSH2 packet decode functions.
813 static unsigned long ssh2_pkt_getuint32(void) {
815 if (pktin
.length
- pktin
.savedpos
< 4)
816 return 0; /* arrgh, no way to decline (FIXME?) */
817 value
= GET_32BIT(pktin
.data
+pktin
.savedpos
);
821 static void ssh2_pkt_getstring(char **p
, int *length
) {
823 if (pktin
.length
- pktin
.savedpos
< 4)
825 *length
= GET_32BIT(pktin
.data
+pktin
.savedpos
);
827 if (pktin
.length
- pktin
.savedpos
< *length
)
829 *p
= pktin
.data
+pktin
.savedpos
;
830 pktin
.savedpos
+= *length
;
832 static Bignum
ssh2_pkt_getmp(void) {
837 ssh2_pkt_getstring(&p
, &length
);
841 bombout(("internal error: Can't handle negative mpints"));
844 b
= newbn((length
+1)/2);
845 for (i
= 0; i
< length
; i
++) {
848 b
[j
/2+1] |= ((unsigned char)p
[i
]) << 8;
850 b
[j
/2+1] |= ((unsigned char)p
[i
]);
855 static int do_ssh_init(unsigned char c
) {
857 static char version
[10];
858 static char vstring
[80];
859 static char vlog
[sizeof(vstring
)+20];
864 /* Search for the string "SSH-" in the input. */
867 static const int transS
[] = { 1, 2, 2, 1 };
868 static const int transH
[] = { 0, 0, 3, 0 };
869 static const int transminus
[] = { 0, 0, 0, -1 };
870 if (c
== 'S') i
= transS
[i
];
871 else if (c
== 'H') i
= transH
[i
];
872 else if (c
== '-') i
= transminus
[i
];
876 crReturn(1); /* get another character */
879 strcpy(vstring
, "SSH-");
883 crReturn(1); /* get another char */
884 if (vsp
< vstring
+sizeof(vstring
)-1)
890 } else if (i
< sizeof(version
)-1)
897 rdpkt2_state
.incoming_sequence
= 0;
900 sprintf(vlog
, "Server version: %s", vstring
);
901 vlog
[strcspn(vlog
, "\r\n")] = '\0';
905 * Server version "1.99" means we can choose whether we use v1
906 * or v2 protocol. Choice is based on cfg.sshprot.
908 if (ssh_versioncmp(version
, cfg
.sshprot
== 1 ?
"2.0" : "1.99") >= 0) {
910 * This is a v2 server. Begin v2 protocol.
912 char *verstring
= "SSH-2.0-PuTTY";
915 * Hash our version string and their version string.
917 sha_string(&exhash
, verstring
, strlen(verstring
));
918 sha_string(&exhash
, vstring
, strcspn(vstring
, "\r\n"));
919 sprintf(vstring
, "%s\n", verstring
);
920 sprintf(vlog
, "We claim version: %s", verstring
);
922 logevent("Using SSH protocol version 2");
923 sk_write(s
, vstring
, strlen(vstring
));
924 ssh_protocol
= ssh2_protocol
;
926 s_rdpkt
= ssh2_rdpkt
;
929 * This is a v1 server. Begin v1 protocol.
931 sprintf(vstring
, "SSH-%s-PuTTY\n",
932 (ssh_versioncmp(version
, "1.5") <= 0 ? version
: "1.5"));
933 sprintf(vlog
, "We claim version: %s", vstring
);
934 vlog
[strcspn(vlog
, "\r\n")] = '\0';
936 logevent("Using SSH protocol version 1");
937 sk_write(s
, vstring
, strlen(vstring
));
938 ssh_protocol
= ssh1_protocol
;
940 s_rdpkt
= ssh1_rdpkt
;
946 static void ssh_gotdata(unsigned char *data
, int datalen
)
951 * To begin with, feed the characters one by one to the
952 * protocol initialisation / selection function do_ssh_init().
953 * When that returns 0, we're done with the initial greeting
954 * exchange and can move on to packet discipline.
959 crReturnV
; /* more data please */
960 ret
= do_ssh_init(*data
);
967 * We emerge from that loop when the initial negotiation is
968 * over and we have selected an s_rdpkt function. Now pass
969 * everything to s_rdpkt, and then pass the resulting packets
970 * to the proper protocol handler.
975 while (datalen
> 0) {
976 if ( s_rdpkt(&data
, &datalen
) == 0 ) {
977 ssh_protocol(NULL
, 0, 1);
978 if (ssh_state
== SSH_STATE_CLOSED
) {
988 static int ssh_receive(Socket s
, int urgent
, char *data
, int len
) {
990 /* Connection has closed. */
995 ssh_gotdata (data
, len
);
1000 * Connect to specified host and port.
1001 * Returns an error message, or NULL on success.
1002 * Also places the canonical host name into `realhost'.
1004 static char *connect_to_host(char *host
, int port
, char **realhost
)
1013 savedhost
= malloc(1+strlen(host
));
1015 fatalbox("Out of memory");
1016 strcpy(savedhost
, host
);
1019 port
= 22; /* default ssh port */
1032 addr
= sk_namelookup(host
, realhost
);
1033 if ( (err
= sk_addr_error(addr
)) )
1043 s
= sk_new(addr
, port
, ssh_receive
);
1044 if ( (err
= sk_socket_error(s
)) )
1048 sk_write(s
, "connect ", 8);
1049 sk_write(s
, FWhost
, strlen(FWhost
));
1052 sprintf(buf
, " %d\n", FWport
);
1053 sk_write(s
, buf
, strlen(buf
));
1061 * Handle the key exchange and user authentication phases.
1063 static int do_ssh1_login(unsigned char *in
, int inlen
, int ispkt
)
1066 unsigned char *rsabuf
, *keystr1
, *keystr2
;
1067 unsigned char cookie
[8];
1068 struct RSAKey servkey
, hostkey
;
1069 struct MD5Context md5c
;
1070 static unsigned long supported_ciphers_mask
, supported_auths_mask
;
1071 static int tried_publickey
;
1072 static unsigned char session_id
[16];
1074 static char username
[100];
1078 if (!ispkt
) crWaitUntil(ispkt
);
1080 if (pktin
.type
!= SSH1_SMSG_PUBLIC_KEY
) {
1081 bombout(("Public key packet not received"));
1085 logevent("Received public keys");
1087 memcpy(cookie
, pktin
.body
, 8);
1089 i
= makekey(pktin
.body
+8, &servkey
, &keystr1
, 0);
1090 j
= makekey(pktin
.body
+8+i
, &hostkey
, &keystr2
, 0);
1093 * Log the host key fingerprint.
1097 logevent("Host key fingerprint is:");
1098 strcpy(logmsg
, " ");
1099 hostkey
.comment
= NULL
;
1100 rsa_fingerprint(logmsg
+strlen(logmsg
), sizeof(logmsg
)-strlen(logmsg
),
1105 supported_ciphers_mask
= GET_32BIT(pktin
.body
+12+i
+j
);
1106 supported_auths_mask
= GET_32BIT(pktin
.body
+16+i
+j
);
1109 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
1110 MD5Update(&md5c
, keystr1
, servkey
.bytes
);
1111 MD5Update(&md5c
, pktin
.body
, 8);
1112 MD5Final(session_id
, &md5c
);
1114 for (i
=0; i
<32; i
++)
1115 session_key
[i
] = random_byte();
1117 len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
1119 rsabuf
= malloc(len
);
1121 fatalbox("Out of memory");
1124 * Verify the host key.
1128 * First format the key into a string.
1130 int len
= rsastr_len(&hostkey
);
1131 char fingerprint
[100];
1132 char *keystr
= malloc(len
);
1134 fatalbox("Out of memory");
1135 rsastr_fmt(keystr
, &hostkey
);
1136 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
1137 verify_ssh_host_key(savedhost
, savedport
, "rsa", keystr
, fingerprint
);
1141 for (i
=0; i
<32; i
++) {
1142 rsabuf
[i
] = session_key
[i
];
1144 rsabuf
[i
] ^= session_id
[i
];
1147 if (hostkey
.bytes
> servkey
.bytes
) {
1148 rsaencrypt(rsabuf
, 32, &servkey
);
1149 rsaencrypt(rsabuf
, servkey
.bytes
, &hostkey
);
1151 rsaencrypt(rsabuf
, 32, &hostkey
);
1152 rsaencrypt(rsabuf
, hostkey
.bytes
, &servkey
);
1155 logevent("Encrypted session key");
1157 cipher_type
= cfg
.cipher
== CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH
:
1158 cfg
.cipher
== CIPHER_DES ? SSH_CIPHER_DES
:
1160 if ((supported_ciphers_mask
& (1 << cipher_type
)) == 0) {
1161 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1162 cipher_type
= SSH_CIPHER_3DES
;
1164 switch (cipher_type
) {
1165 case SSH_CIPHER_3DES
: logevent("Using 3DES encryption"); break;
1166 case SSH_CIPHER_DES
: logevent("Using single-DES encryption"); break;
1167 case SSH_CIPHER_BLOWFISH
: logevent("Using Blowfish encryption"); break;
1170 send_packet(SSH1_CMSG_SESSION_KEY
,
1171 PKT_CHAR
, cipher_type
,
1172 PKT_DATA
, cookie
, 8,
1173 PKT_CHAR
, (len
*8) >> 8, PKT_CHAR
, (len
*8) & 0xFF,
1174 PKT_DATA
, rsabuf
, len
,
1178 logevent("Trying to enable encryption...");
1182 cipher
= cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
1183 cipher_type
== SSH_CIPHER_DES ?
&ssh_des
:
1185 cipher
->sesskey(session_key
);
1189 if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1190 bombout(("Encryption not successfully enabled"));
1194 logevent("Successfully started encryption");
1200 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
1201 c_write("login as: ", 10);
1204 crWaitUntil(!ispkt
);
1205 while (inlen
--) switch (c
= *in
++) {
1212 c_write("\b \b", 3);
1218 c_write("\b \b", 3);
1227 if (((c
>= ' ' && c
<= '~') ||
1228 ((unsigned char)c
>= 160)) && pos
< 40) {
1229 username
[pos
++] = c
;
1236 username
[strcspn(username
, "\n\r")] = '\0';
1239 strncpy(username
, cfg
.username
, 99);
1240 username
[99] = '\0';
1241 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
1242 sprintf(stuff
, "Sent username \"%s\".\r\n", username
);
1243 c_write(stuff
, strlen(stuff
));
1247 send_packet(SSH1_CMSG_USER
, PKT_STR
, username
, PKT_END
);
1249 char userlog
[20+sizeof(username
)];
1250 sprintf(userlog
, "Sent username \"%s\"", username
);
1257 tried_publickey
= 0;
1259 while (pktin
.type
== SSH1_SMSG_FAILURE
) {
1260 static char password
[100];
1261 static char prompt
[200];
1264 static int pwpkt_type
;
1266 * Show password prompt, having first obtained it via a TIS
1267 * or CryptoCard exchange if we're doing TIS or CryptoCard
1270 pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
1271 if (agent_exists()) {
1273 * Attempt RSA authentication using Pageant.
1275 static unsigned char request
[5], *response
, *p
;
1276 static int responselen
;
1277 static int i
, nkeys
;
1278 static int authed
= FALSE
;
1281 logevent("Pageant is running. Requesting keys.");
1283 /* Request the keys held by the agent. */
1284 PUT_32BIT(request
, 1);
1285 request
[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES
;
1286 agent_query(request
, 5, &r
, &responselen
);
1287 response
= (unsigned char *)r
;
1290 nkeys
= GET_32BIT(p
); p
+= 4;
1291 { char buf
[64]; sprintf(buf
, "Pageant has %d keys", nkeys
);
1293 for (i
= 0; i
< nkeys
; i
++) {
1294 static struct RSAKey key
;
1295 static Bignum challenge
;
1296 static char *commentp
;
1297 static int commentlen
;
1299 { char buf
[64]; sprintf(buf
, "Trying Pageant key #%d", i
);
1302 p
+= ssh1_read_bignum(p
, &key
.exponent
);
1303 p
+= ssh1_read_bignum(p
, &key
.modulus
);
1304 commentlen
= GET_32BIT(p
); p
+= 4;
1305 commentp
= p
; p
+= commentlen
;
1306 send_packet(SSH1_CMSG_AUTH_RSA
,
1307 PKT_BIGNUM
, key
.modulus
, PKT_END
);
1309 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
1310 logevent("Key refused");
1313 logevent("Received RSA challenge");
1314 ssh1_read_bignum(pktin
.body
, &challenge
);
1316 char *agentreq
, *q
, *ret
;
1318 len
= 1 + 4; /* message type, bit count */
1319 len
+= ssh1_bignum_length(key
.exponent
);
1320 len
+= ssh1_bignum_length(key
.modulus
);
1321 len
+= ssh1_bignum_length(challenge
);
1322 len
+= 16; /* session id */
1323 len
+= 4; /* response format */
1324 agentreq
= malloc(4 + len
);
1325 PUT_32BIT(agentreq
, len
);
1327 *q
++ = SSH_AGENTC_RSA_CHALLENGE
;
1328 PUT_32BIT(q
, ssh1_bignum_bitcount(key
.modulus
));
1330 q
+= ssh1_write_bignum(q
, key
.exponent
);
1331 q
+= ssh1_write_bignum(q
, key
.modulus
);
1332 q
+= ssh1_write_bignum(q
, challenge
);
1333 memcpy(q
, session_id
, 16); q
+= 16;
1334 PUT_32BIT(q
, 1); /* response format */
1335 agent_query(agentreq
, len
+4, &ret
, &retlen
);
1338 if (ret
[4] == SSH_AGENT_RSA_RESPONSE
) {
1339 logevent("Sending Pageant's response");
1340 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
1341 PKT_DATA
, ret
+5, 16, PKT_END
);
1344 if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
1345 logevent("Pageant's response accepted");
1346 if (flags
& FLAG_VERBOSE
) {
1347 c_write("Authenticated using RSA key \"",
1349 c_write(commentp
, commentlen
);
1350 c_write("\" from agent\r\n", 14);
1354 logevent("Pageant's response not accepted");
1356 logevent("Pageant failed to answer challenge");
1360 logevent("No reply received from Pageant");
1363 freebn(key
.exponent
);
1364 freebn(key
.modulus
);
1373 if (*cfg
.keyfile
&& !tried_publickey
)
1374 pwpkt_type
= SSH1_CMSG_AUTH_RSA
;
1376 if (pktin
.type
== SSH1_SMSG_FAILURE
&&
1378 (supported_auths_mask
& (1<<SSH1_AUTH_TIS
))) {
1379 pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
1380 logevent("Requested TIS authentication");
1381 send_packet(SSH1_CMSG_AUTH_TIS
, PKT_END
);
1383 if (pktin
.type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
1384 logevent("TIS authentication declined");
1385 if (flags
& FLAG_INTERACTIVE
)
1386 c_write("TIS authentication refused.\r\n", 29);
1388 int challengelen
= ((pktin
.body
[0] << 24) |
1389 (pktin
.body
[1] << 16) |
1390 (pktin
.body
[2] << 8) |
1392 logevent("Received TIS challenge");
1393 if (challengelen
> sizeof(prompt
)-1)
1394 challengelen
= sizeof(prompt
)-1; /* prevent overrun */
1395 memcpy(prompt
, pktin
.body
+4, challengelen
);
1396 prompt
[challengelen
] = '\0';
1399 if (pktin
.type
== SSH1_SMSG_FAILURE
&&
1401 (supported_auths_mask
& (1<<SSH1_AUTH_CCARD
))) {
1402 pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
1403 logevent("Requested CryptoCard authentication");
1404 send_packet(SSH1_CMSG_AUTH_CCARD
, PKT_END
);
1406 if (pktin
.type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
1407 logevent("CryptoCard authentication declined");
1408 c_write("CryptoCard authentication refused.\r\n", 29);
1410 int challengelen
= ((pktin
.body
[0] << 24) |
1411 (pktin
.body
[1] << 16) |
1412 (pktin
.body
[2] << 8) |
1414 logevent("Received CryptoCard challenge");
1415 if (challengelen
> sizeof(prompt
)-1)
1416 challengelen
= sizeof(prompt
)-1; /* prevent overrun */
1417 memcpy(prompt
, pktin
.body
+4, challengelen
);
1418 strncpy(prompt
+ challengelen
, "\r\nResponse : ",
1419 sizeof(prompt
)-challengelen
);
1420 prompt
[sizeof(prompt
)-1] = '\0';
1423 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
1424 sprintf(prompt
, "%.90s@%.90s's password: ",
1425 username
, savedhost
);
1427 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
1428 char *comment
= NULL
;
1429 if (flags
& FLAG_VERBOSE
)
1430 c_write("Trying public key authentication.\r\n", 35);
1431 if (!rsakey_encrypted(cfg
.keyfile
, &comment
)) {
1432 if (flags
& FLAG_VERBOSE
)
1433 c_write("No passphrase required.\r\n", 25);
1436 sprintf(prompt
, "Passphrase for key \"%.100s\": ", comment
);
1440 if (ssh_get_password
) {
1441 if (!ssh_get_password(prompt
, password
, sizeof(password
))) {
1443 * get_password failed to get a password (for
1444 * example because one was supplied on the command
1445 * line which has already failed to work).
1448 logevent("No more passwords to try");
1449 ssh_state
= SSH_STATE_CLOSED
;
1453 c_write(prompt
, strlen(prompt
));
1457 crWaitUntil(!ispkt
);
1458 while (inlen
--) switch (c
= *in
++) {
1475 if (((c
>= ' ' && c
<= '~') ||
1476 ((unsigned char)c
>= 160)) && pos
< sizeof(password
))
1477 password
[pos
++] = c
;
1485 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
1487 * Try public key authentication with the specified
1490 static struct RSAKey pubkey
;
1491 static Bignum challenge
, response
;
1493 static unsigned char buffer
[32];
1495 tried_publickey
= 1;
1496 i
= loadrsakey(cfg
.keyfile
, &pubkey
, NULL
, password
);
1498 c_write("Couldn't load public key from ", 30);
1499 c_write(cfg
.keyfile
, strlen(cfg
.keyfile
));
1500 c_write(".\r\n", 3);
1501 continue; /* go and try password */
1504 c_write("Wrong passphrase.\r\n", 19);
1505 tried_publickey
= 0;
1506 continue; /* try again */
1510 * Send a public key attempt.
1512 send_packet(SSH1_CMSG_AUTH_RSA
,
1513 PKT_BIGNUM
, pubkey
.modulus
, PKT_END
);
1516 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1517 c_write("Server refused our public key.\r\n", 32);
1518 continue; /* go and try password */
1520 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
1521 bombout(("Bizarre response to offer of public key"));
1524 ssh1_read_bignum(pktin
.body
, &challenge
);
1525 response
= rsadecrypt(challenge
, &pubkey
);
1526 freebn(pubkey
.private_exponent
); /* burn the evidence */
1528 for (i
= 0; i
< 32; i
+= 2) {
1529 buffer
[i
] = response
[16-i
/2] >> 8;
1530 buffer
[i
+1] = response
[16-i
/2] & 0xFF;
1534 MD5Update(&md5c
, buffer
, 32);
1535 MD5Update(&md5c
, session_id
, 16);
1536 MD5Final(buffer
, &md5c
);
1538 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
1539 PKT_DATA
, buffer
, 16, PKT_END
);
1542 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1543 if (flags
& FLAG_VERBOSE
)
1544 c_write("Failed to authenticate with our public key.\r\n",
1546 continue; /* go and try password */
1547 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1548 bombout(("Bizarre response to RSA authentication response"));
1552 break; /* we're through! */
1554 send_packet(pwpkt_type
, PKT_STR
, password
, PKT_END
);
1556 logevent("Sent password");
1557 memset(password
, 0, strlen(password
));
1559 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1560 if (flags
& FLAG_VERBOSE
)
1561 c_write("Access denied\r\n", 15);
1562 logevent("Authentication refused");
1563 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
1564 logevent("Received disconnect request");
1565 ssh_state
= SSH_STATE_CLOSED
;
1567 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1568 bombout(("Strange packet received, type %d", pktin
.type
));
1573 logevent("Authentication successful");
1578 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
) {
1583 while (!do_ssh1_login(in
, inlen
, ispkt
)) {
1586 if (ssh_state
== SSH_STATE_CLOSED
)
1589 if (cfg
.agentfwd
&& agent_exists()) {
1590 logevent("Requesting agent forwarding");
1591 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
1592 do { crReturnV
; } while (!ispkt
);
1593 if (pktin
.type
!= SSH1_SMSG_SUCCESS
&& pktin
.type
!= SSH1_SMSG_FAILURE
) {
1594 bombout(("Protocol confusion"));
1596 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1597 logevent("Agent forwarding refused");
1599 logevent("Agent forwarding enabled");
1603 send_packet(SSH1_CMSG_REQUEST_PTY
,
1604 PKT_STR
, cfg
.termtype
,
1605 PKT_INT
, rows
, PKT_INT
, cols
,
1606 PKT_INT
, 0, PKT_INT
, 0,
1609 ssh_state
= SSH_STATE_INTERMED
;
1610 do { crReturnV
; } while (!ispkt
);
1611 if (pktin
.type
!= SSH1_SMSG_SUCCESS
&& pktin
.type
!= SSH1_SMSG_FAILURE
) {
1612 bombout(("Protocol confusion"));
1614 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1615 c_write("Server refused to allocate pty\r\n", 32);
1617 logevent("Allocated pty");
1620 if (*cfg
.remote_cmd
)
1621 send_packet(SSH1_CMSG_EXEC_CMD
, PKT_STR
, cfg
.remote_cmd
, PKT_END
);
1623 send_packet(SSH1_CMSG_EXEC_SHELL
, PKT_END
);
1624 logevent("Started session");
1626 ssh_state
= SSH_STATE_SESSION
;
1631 ssh_channels
= newtree234(ssh_channelcmp
);
1636 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
1637 pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
1638 long len
= GET_32BIT(pktin
.body
);
1639 from_backend(pktin
.type
== SSH1_SMSG_STDERR_DATA
,
1641 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
1642 ssh_state
= SSH_STATE_CLOSED
;
1643 logevent("Received disconnect request");
1644 } else if (pktin
.type
== SSH1_SMSG_AGENT_OPEN
) {
1645 /* Remote side is trying to open a channel to talk to our
1646 * agent. Give them back a local channel number. */
1648 struct ssh_channel
*c
;
1650 for (c
= first234(ssh_channels
, &e
); c
; c
= next234(&e
)) {
1652 break; /* found a free number */
1655 c
= malloc(sizeof(struct ssh_channel
));
1656 c
->remoteid
= GET_32BIT(pktin
.body
);
1659 c
->type
= SSH1_SMSG_AGENT_OPEN
; /* identify channel type */
1660 c
->u
.a
.lensofar
= 0;
1661 add234(ssh_channels
, c
);
1662 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
1663 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
1665 } else if (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE
||
1666 pktin
.type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
) {
1667 /* Remote side closes a channel. */
1668 unsigned i
= GET_32BIT(pktin
.body
);
1669 struct ssh_channel
*c
;
1670 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
1673 closetype
= (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
1 : 2);
1674 send_packet(pktin
.type
, PKT_INT
, c
->remoteid
, PKT_END
);
1675 c
->closes
|= closetype
;
1676 if (c
->closes
== 3) {
1677 del234(ssh_channels
, c
);
1681 } else if (pktin
.type
== SSH1_MSG_CHANNEL_DATA
) {
1682 /* Data sent down one of our channels. */
1683 int i
= GET_32BIT(pktin
.body
);
1684 int len
= GET_32BIT(pktin
.body
+4);
1685 unsigned char *p
= pktin
.body
+8;
1686 struct ssh_channel
*c
;
1687 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
1690 case SSH1_SMSG_AGENT_OPEN
:
1691 /* Data for an agent message. Buffer it. */
1693 if (c
->u
.a
.lensofar
< 4) {
1694 int l
= min(4 - c
->u
.a
.lensofar
, len
);
1695 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
, l
);
1696 p
+= l
; len
-= l
; c
->u
.a
.lensofar
+= l
;
1698 if (c
->u
.a
.lensofar
== 4) {
1699 c
->u
.a
.totallen
= 4 + GET_32BIT(c
->u
.a
.msglen
);
1700 c
->u
.a
.message
= malloc(c
->u
.a
.totallen
);
1701 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
1703 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
1704 int l
= min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
, len
);
1705 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
, l
);
1706 p
+= l
; len
-= l
; c
->u
.a
.lensofar
+= l
;
1708 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
1709 void *reply
, *sentreply
;
1711 agent_query(c
->u
.a
.message
, c
->u
.a
.totallen
,
1716 /* Fake SSH_AGENT_FAILURE. */
1717 sentreply
= "\0\0\0\1\5";
1720 send_packet(SSH1_MSG_CHANNEL_DATA
,
1721 PKT_INT
, c
->remoteid
,
1723 PKT_DATA
, sentreply
, replylen
,
1727 free(c
->u
.a
.message
);
1728 c
->u
.a
.lensofar
= 0;
1734 } else if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
1735 /* may be from EXEC_SHELL on some servers */
1736 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1737 /* may be from EXEC_SHELL on some servers
1738 * if no pty is available or in other odd cases. Ignore */
1739 } else if (pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
1740 send_packet(SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
1742 bombout(("Strange packet received: type %d", pktin
.type
));
1747 int len
= min(inlen
, 512);
1748 send_packet(SSH1_CMSG_STDIN_DATA
,
1749 PKT_INT
, len
, PKT_DATA
, in
, len
, PKT_END
);
1760 * Utility routine for decoding comma-separated strings in KEXINIT.
1762 static int in_commasep_string(char *needle
, char *haystack
, int haylen
) {
1763 int needlen
= strlen(needle
);
1766 * Is it at the start of the string?
1768 if (haylen
>= needlen
&& /* haystack is long enough */
1769 !memcmp(needle
, haystack
, needlen
) && /* initial match */
1770 (haylen
== needlen
|| haystack
[needlen
] == ',')
1771 /* either , or EOS follows */
1775 * If not, search for the next comma and resume after that.
1776 * If no comma found, terminate.
1778 while (haylen
> 0 && *haystack
!= ',')
1779 haylen
--, haystack
++;
1782 haylen
--, haystack
++; /* skip over comma itself */
1787 * SSH2 key creation method.
1789 static void ssh2_mkkey(Bignum K
, char *H
, char chr
, char *keyspace
) {
1791 /* First 20 bytes. */
1794 SHA_Bytes(&s
, H
, 20);
1795 SHA_Bytes(&s
, &chr
, 1);
1796 SHA_Bytes(&s
, H
, 20);
1797 SHA_Final(&s
, keyspace
);
1798 /* Next 20 bytes. */
1801 SHA_Bytes(&s
, H
, 20);
1802 SHA_Bytes(&s
, keyspace
, 20);
1803 SHA_Final(&s
, keyspace
+20);
1807 * Handle the SSH2 transport layer.
1809 static int do_ssh2_transport(unsigned char *in
, int inlen
, int ispkt
)
1813 static Bignum e
, f
, K
;
1814 static const struct ssh_mac
**maclist
;
1816 static const struct ssh_cipher
*cscipher_tobe
= NULL
;
1817 static const struct ssh_cipher
*sccipher_tobe
= NULL
;
1818 static const struct ssh_mac
*csmac_tobe
= NULL
;
1819 static const struct ssh_mac
*scmac_tobe
= NULL
;
1820 static const struct ssh_compress
*cscomp_tobe
= NULL
;
1821 static const struct ssh_compress
*sccomp_tobe
= NULL
;
1822 static char *hostkeydata
, *sigdata
, *keystr
, *fingerprint
;
1823 static int hostkeylen
, siglen
;
1824 static unsigned char exchange_hash
[20];
1825 static unsigned char keyspace
[40];
1826 static const struct ssh_cipher
*preferred_cipher
;
1832 * Set up the preferred cipher.
1834 if (cfg
.cipher
== CIPHER_BLOWFISH
) {
1835 preferred_cipher
= &ssh_blowfish_ssh2
;
1836 } else if (cfg
.cipher
== CIPHER_DES
) {
1837 logevent("Single DES not supported in SSH2; using 3DES");
1838 preferred_cipher
= &ssh_3des_ssh2
;
1839 } else if (cfg
.cipher
== CIPHER_3DES
) {
1840 preferred_cipher
= &ssh_3des_ssh2
;
1842 /* Shouldn't happen, but we do want to initialise to _something_. */
1843 preferred_cipher
= &ssh_3des_ssh2
;
1847 * Be prepared to work around the buggy MAC problem.
1850 maclist
= buggymacs
, nmacs
= lenof(buggymacs
);
1852 maclist
= macs
, nmacs
= lenof(macs
);
1856 * Construct and send our key exchange packet.
1858 ssh2_pkt_init(SSH2_MSG_KEXINIT
);
1859 for (i
= 0; i
< 16; i
++)
1860 ssh2_pkt_addbyte((unsigned char)random_byte());
1861 /* List key exchange algorithms. */
1862 ssh2_pkt_addstring_start();
1863 for (i
= 0; i
< lenof(kex_algs
); i
++) {
1864 ssh2_pkt_addstring_str(kex_algs
[i
]->name
);
1865 if (i
< lenof(kex_algs
)-1)
1866 ssh2_pkt_addstring_str(",");
1868 /* List server host key algorithms. */
1869 ssh2_pkt_addstring_start();
1870 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
1871 ssh2_pkt_addstring_str(hostkey_algs
[i
]->name
);
1872 if (i
< lenof(hostkey_algs
)-1)
1873 ssh2_pkt_addstring_str(",");
1875 /* List client->server encryption algorithms. */
1876 ssh2_pkt_addstring_start();
1877 for (i
= 0; i
< lenof(ciphers
)+1; i
++) {
1878 const struct ssh_cipher
*c
= i
==0 ? preferred_cipher
: ciphers
[i
-1];
1879 ssh2_pkt_addstring_str(c
->name
);
1880 if (i
< lenof(ciphers
))
1881 ssh2_pkt_addstring_str(",");
1883 /* List server->client encryption algorithms. */
1884 ssh2_pkt_addstring_start();
1885 for (i
= 0; i
< lenof(ciphers
)+1; i
++) {
1886 const struct ssh_cipher
*c
= i
==0 ? preferred_cipher
: ciphers
[i
-1];
1887 ssh2_pkt_addstring_str(c
->name
);
1888 if (i
< lenof(ciphers
))
1889 ssh2_pkt_addstring_str(",");
1891 /* List client->server MAC algorithms. */
1892 ssh2_pkt_addstring_start();
1893 for (i
= 0; i
< nmacs
; i
++) {
1894 ssh2_pkt_addstring_str(maclist
[i
]->name
);
1896 ssh2_pkt_addstring_str(",");
1898 /* List server->client MAC algorithms. */
1899 ssh2_pkt_addstring_start();
1900 for (i
= 0; i
< nmacs
; i
++) {
1901 ssh2_pkt_addstring_str(maclist
[i
]->name
);
1903 ssh2_pkt_addstring_str(",");
1905 /* List client->server compression algorithms. */
1906 ssh2_pkt_addstring_start();
1907 for (i
= 0; i
< lenof(compressions
); i
++) {
1908 ssh2_pkt_addstring_str(compressions
[i
]->name
);
1909 if (i
< lenof(compressions
)-1)
1910 ssh2_pkt_addstring_str(",");
1912 /* List server->client compression algorithms. */
1913 ssh2_pkt_addstring_start();
1914 for (i
= 0; i
< lenof(compressions
); i
++) {
1915 ssh2_pkt_addstring_str(compressions
[i
]->name
);
1916 if (i
< lenof(compressions
)-1)
1917 ssh2_pkt_addstring_str(",");
1919 /* List client->server languages. Empty list. */
1920 ssh2_pkt_addstring_start();
1921 /* List server->client languages. Empty list. */
1922 ssh2_pkt_addstring_start();
1923 /* First KEX packet does _not_ follow, because we're not that brave. */
1924 ssh2_pkt_addbool(FALSE
);
1926 ssh2_pkt_adduint32(0);
1927 sha_string(&exhash
, pktout
.data
+5, pktout
.length
-5);
1930 if (!ispkt
) crWaitUntil(ispkt
);
1931 sha_string(&exhash
, pktin
.data
+5, pktin
.length
-5);
1934 * Now examine the other side's KEXINIT to see what we're up
1937 if (pktin
.type
!= SSH2_MSG_KEXINIT
) {
1938 bombout(("expected key exchange packet from server"));
1941 kex
= NULL
; hostkey
= NULL
; cscipher_tobe
= NULL
; sccipher_tobe
= NULL
;
1942 csmac_tobe
= NULL
; scmac_tobe
= NULL
; cscomp_tobe
= NULL
; sccomp_tobe
= NULL
;
1943 pktin
.savedpos
+= 16; /* skip garbage cookie */
1944 ssh2_pkt_getstring(&str
, &len
); /* key exchange algorithms */
1945 for (i
= 0; i
< lenof(kex_algs
); i
++) {
1946 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
1951 ssh2_pkt_getstring(&str
, &len
); /* host key algorithms */
1952 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
1953 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
1954 hostkey
= hostkey_algs
[i
];
1958 ssh2_pkt_getstring(&str
, &len
); /* client->server cipher */
1959 for (i
= 0; i
< lenof(ciphers
)+1; i
++) {
1960 const struct ssh_cipher
*c
= i
==0 ? preferred_cipher
: ciphers
[i
-1];
1961 if (in_commasep_string(c
->name
, str
, len
)) {
1966 ssh2_pkt_getstring(&str
, &len
); /* server->client cipher */
1967 for (i
= 0; i
< lenof(ciphers
)+1; i
++) {
1968 const struct ssh_cipher
*c
= i
==0 ? preferred_cipher
: ciphers
[i
-1];
1969 if (in_commasep_string(c
->name
, str
, len
)) {
1974 ssh2_pkt_getstring(&str
, &len
); /* client->server mac */
1975 for (i
= 0; i
< nmacs
; i
++) {
1976 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
1977 csmac_tobe
= maclist
[i
];
1981 ssh2_pkt_getstring(&str
, &len
); /* server->client mac */
1982 for (i
= 0; i
< nmacs
; i
++) {
1983 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
1984 scmac_tobe
= maclist
[i
];
1988 ssh2_pkt_getstring(&str
, &len
); /* client->server compression */
1989 for (i
= 0; i
< lenof(compressions
); i
++) {
1990 if (in_commasep_string(compressions
[i
]->name
, str
, len
)) {
1991 cscomp_tobe
= compressions
[i
];
1995 ssh2_pkt_getstring(&str
, &len
); /* server->client compression */
1996 for (i
= 0; i
< lenof(compressions
); i
++) {
1997 if (in_commasep_string(compressions
[i
]->name
, str
, len
)) {
1998 sccomp_tobe
= compressions
[i
];
2004 * Currently we only support Diffie-Hellman and DSS, so let's
2005 * bomb out if those aren't selected.
2007 if (kex
!= &ssh_diffiehellman
|| hostkey
!= &ssh_dss
) {
2008 bombout(("internal fault: chaos in SSH 2 transport layer"));
2013 * Now we begin the fun. Generate and send e for Diffie-Hellman.
2016 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT
);
2021 if (pktin
.type
!= SSH2_MSG_KEXDH_REPLY
) {
2022 bombout(("expected key exchange packet from server"));
2025 ssh2_pkt_getstring(&hostkeydata
, &hostkeylen
);
2026 f
= ssh2_pkt_getmp();
2027 ssh2_pkt_getstring(&sigdata
, &siglen
);
2031 sha_string(&exhash
, hostkeydata
, hostkeylen
);
2032 sha_mpint(&exhash
, e
);
2033 sha_mpint(&exhash
, f
);
2034 sha_mpint(&exhash
, K
);
2035 SHA_Final(&exhash
, exchange_hash
);
2038 debug(("Exchange hash is:\r\n"));
2039 for (i
= 0; i
< 20; i
++)
2040 debug((" %02x", exchange_hash
[i
]));
2044 hostkey
->setkey(hostkeydata
, hostkeylen
);
2045 if (!hostkey
->verifysig(sigdata
, siglen
, exchange_hash
, 20)) {
2046 bombout(("Server failed host key check"));
2051 * Expect SSH2_MSG_NEWKEYS from server.
2054 if (pktin
.type
!= SSH2_MSG_NEWKEYS
) {
2055 bombout(("expected new-keys packet from server"));
2060 * Authenticate remote host: verify host key. (We've already
2061 * checked the signature of the exchange hash.)
2063 keystr
= hostkey
->fmtkey();
2064 fingerprint
= hostkey
->fingerprint();
2065 verify_ssh_host_key(savedhost
, savedport
, hostkey
->keytype
,
2066 keystr
, fingerprint
);
2067 logevent("Host key fingerprint is:");
2068 logevent(fingerprint
);
2073 * Send SSH2_MSG_NEWKEYS.
2075 ssh2_pkt_init(SSH2_MSG_NEWKEYS
);
2079 * Create and initialise session keys.
2081 cscipher
= cscipher_tobe
;
2082 sccipher
= sccipher_tobe
;
2085 cscomp
= cscomp_tobe
;
2086 sccomp
= sccomp_tobe
;
2088 * Set IVs after keys.
2090 ssh2_mkkey(K
, exchange_hash
, 'C', keyspace
); cscipher
->setcskey(keyspace
);
2091 ssh2_mkkey(K
, exchange_hash
, 'D', keyspace
); cscipher
->setsckey(keyspace
);
2092 ssh2_mkkey(K
, exchange_hash
, 'A', keyspace
); cscipher
->setcsiv(keyspace
);
2093 ssh2_mkkey(K
, exchange_hash
, 'B', keyspace
); sccipher
->setsciv(keyspace
);
2094 ssh2_mkkey(K
, exchange_hash
, 'E', keyspace
); csmac
->setcskey(keyspace
);
2095 ssh2_mkkey(K
, exchange_hash
, 'F', keyspace
); scmac
->setsckey(keyspace
);
2098 * Now we're encrypting. Begin returning 1 to the protocol main
2099 * function so that other things can run on top of the
2100 * transport. If we ever see a KEXINIT, we must go back to the
2105 } while (!(ispkt
&& pktin
.type
== SSH2_MSG_KEXINIT
));
2106 goto begin_key_exchange
;
2112 * Handle the SSH2 userauth and connection layers.
2114 static void do_ssh2_authconn(unsigned char *in
, int inlen
, int ispkt
)
2116 static unsigned long remote_winsize
;
2117 static unsigned long remote_maxpkt
;
2122 * Request userauth protocol, and await a response to it.
2124 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
2125 ssh2_pkt_addstring("ssh-userauth");
2127 crWaitUntilV(ispkt
);
2128 if (pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
) {
2129 bombout(("Server refused user authentication protocol"));
2134 * FIXME: currently we support only password authentication.
2135 * (This places us technically in violation of the SSH2 spec.
2136 * We must fix this.)
2140 * Get a username and a password.
2142 static char username
[100];
2143 static char password
[100];
2147 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
2148 c_write("login as: ", 10);
2151 crWaitUntilV(!ispkt
);
2152 while (inlen
--) switch (c
= *in
++) {
2159 c_write("\b \b", 3);
2165 c_write("\b \b", 3);
2174 if (((c
>= ' ' && c
<= '~') ||
2175 ((unsigned char)c
>= 160)) && pos
< 40) {
2176 username
[pos
++] = c
;
2183 username
[strcspn(username
, "\n\r")] = '\0';
2186 strncpy(username
, cfg
.username
, 99);
2187 username
[99] = '\0';
2188 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
2189 sprintf(stuff
, "Using username \"%s\".\r\n", username
);
2190 c_write(stuff
, strlen(stuff
));
2194 if (ssh_get_password
) {
2196 sprintf(prompt
, "%.90s@%.90s's password: ", username
, savedhost
);
2197 if (!ssh_get_password(prompt
, password
, sizeof(password
))) {
2199 * get_password failed to get a password (for
2200 * example because one was supplied on the command
2201 * line which has already failed to work).
2204 logevent("No more passwords to try");
2205 ssh_state
= SSH_STATE_CLOSED
;
2209 c_write("password: ", 10);
2214 crWaitUntilV(!ispkt
);
2215 while (inlen
--) switch (c
= *in
++) {
2232 if (((c
>= ' ' && c
<= '~') ||
2233 ((unsigned char)c
>= 160)) && pos
< 40)
2234 password
[pos
++] = c
;
2241 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
2242 ssh2_pkt_addstring(username
);
2243 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2244 ssh2_pkt_addstring("password");
2245 ssh2_pkt_addbool(FALSE
);
2246 ssh2_pkt_addstring(password
);
2249 crWaitUntilV(ispkt
);
2250 if (pktin
.type
!= SSH2_MSG_USERAUTH_SUCCESS
) {
2251 c_write("Access denied\r\n", 15);
2252 logevent("Authentication refused");
2258 * Now we're authenticated for the connection protocol. The
2259 * connection protocol will automatically have started at this
2260 * point; there's no need to send SERVICE_REQUEST.
2264 * So now create a channel with a session in it.
2266 mainchan
= malloc(sizeof(struct ssh_channel
));
2267 mainchan
->localid
= 100; /* as good as any */
2268 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
2269 ssh2_pkt_addstring("session");
2270 ssh2_pkt_adduint32(mainchan
->localid
);
2271 ssh2_pkt_adduint32(0x8000UL
); /* our window size */
2272 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
2274 crWaitUntilV(ispkt
);
2275 if (pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
2276 bombout(("Server refused to open a session"));
2278 /* FIXME: error data comes back in FAILURE packet */
2280 if (ssh2_pkt_getuint32() != mainchan
->localid
) {
2281 bombout(("Server's channel confirmation cited wrong channel"));
2284 mainchan
->remoteid
= ssh2_pkt_getuint32();
2285 mainchan
->u
.v2
.remwindow
= ssh2_pkt_getuint32();
2286 mainchan
->u
.v2
.remmaxpkt
= ssh2_pkt_getuint32();
2287 mainchan
->u
.v2
.outbuffer
= NULL
;
2288 mainchan
->u
.v2
.outbuflen
= mainchan
->u
.v2
.outbufsize
= 0;
2289 logevent("Opened channel for session");
2292 * Now allocate a pty for the session.
2295 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
2296 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
2297 ssh2_pkt_addstring("pty-req");
2298 ssh2_pkt_addbool(1); /* want reply */
2299 ssh2_pkt_addstring(cfg
.termtype
);
2300 ssh2_pkt_adduint32(cols
);
2301 ssh2_pkt_adduint32(rows
);
2302 ssh2_pkt_adduint32(0); /* pixel width */
2303 ssh2_pkt_adduint32(0); /* pixel height */
2304 ssh2_pkt_addstring_start();
2305 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
2309 crWaitUntilV(ispkt
);
2310 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
2311 /* FIXME: be able to handle other channels here */
2312 if (ssh2_pkt_getuint32() != mainchan
->localid
)
2313 continue; /* wrong channel */
2314 mainchan
->u
.v2
.remwindow
+= ssh2_pkt_getuint32();
2316 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
2318 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
2319 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
2320 bombout(("Server got confused by pty request"));
2323 c_write("Server refused to allocate pty\r\n", 32);
2325 logevent("Allocated pty");
2330 * Start a shell or a remote command.
2332 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
2333 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
2334 if (*cfg
.remote_cmd
) {
2335 ssh2_pkt_addstring("exec");
2336 ssh2_pkt_addbool(1); /* want reply */
2337 ssh2_pkt_addstring(cfg
.remote_cmd
);
2339 ssh2_pkt_addstring("shell");
2340 ssh2_pkt_addbool(1); /* want reply */
2344 crWaitUntilV(ispkt
);
2345 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
2346 /* FIXME: be able to handle other channels here */
2347 if (ssh2_pkt_getuint32() != mainchan
->localid
)
2348 continue; /* wrong channel */
2349 mainchan
->u
.v2
.remwindow
+= ssh2_pkt_getuint32();
2351 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
2352 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
2353 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
2354 bombout(("Server got confused by shell/command request"));
2357 bombout(("Server refused to start a shell/command"));
2360 logevent("Started a shell/command");
2369 static int try_send
;
2373 if (pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
2374 pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
2377 /* FIXME: be able to handle other channels here */
2378 if (ssh2_pkt_getuint32() != mainchan
->localid
)
2379 continue; /* wrong channel */
2380 if (pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
2381 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR
)
2382 continue; /* extended but not stderr */
2383 ssh2_pkt_getstring(&data
, &length
);
2385 from_backend(pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
,
2388 * Enlarge the window again at the remote side,
2389 * just in case it ever runs down and they fail
2390 * to send us any more data.
2392 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
2393 ssh2_pkt_adduint32(mainchan
->remoteid
);
2394 ssh2_pkt_adduint32(length
);
2397 } else if (pktin
.type
== SSH2_MSG_DISCONNECT
) {
2398 ssh_state
= SSH_STATE_CLOSED
;
2399 logevent("Received disconnect message");
2400 } else if (pktin
.type
== SSH2_MSG_CHANNEL_REQUEST
) {
2401 continue; /* exit status et al; ignore (FIXME?) */
2402 } else if (pktin
.type
== SSH2_MSG_CHANNEL_EOF
) {
2403 continue; /* remote sends EOF; ignore */
2404 } else if (pktin
.type
== SSH2_MSG_CHANNEL_CLOSE
) {
2405 /* FIXME: be able to handle other channels here */
2406 if (ssh2_pkt_getuint32() != mainchan
->localid
)
2407 continue; /* wrong channel */
2408 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
2409 ssh2_pkt_adduint32(mainchan
->remoteid
);
2411 /* FIXME: mark the channel as closed */
2412 if (1 /* FIXME: "all channels are closed" */) {
2413 logevent("All channels closed. Disconnecting");
2414 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
2416 ssh_state
= SSH_STATE_CLOSED
;
2420 continue; /* remote sends close; ignore (FIXME) */
2421 } else if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
2422 /* FIXME: be able to handle other channels here */
2423 if (ssh2_pkt_getuint32() != mainchan
->localid
)
2424 continue; /* wrong channel */
2425 mainchan
->u
.v2
.remwindow
+= ssh2_pkt_getuint32();
2428 bombout(("Strange packet received: type %d", pktin
.type
));
2433 * We have spare data. Add it to the channel buffer.
2435 if (mainchan
->u
.v2
.outbufsize
<
2436 mainchan
->u
.v2
.outbuflen
+ inlen
) {
2437 mainchan
->u
.v2
.outbufsize
=
2438 mainchan
->u
.v2
.outbuflen
+ inlen
+ 1024;
2439 mainchan
->u
.v2
.outbuffer
= srealloc(mainchan
->u
.v2
.outbuffer
,
2440 mainchan
->u
.v2
.outbufsize
);
2442 memcpy(mainchan
->u
.v2
.outbuffer
+ mainchan
->u
.v2
.outbuflen
,
2444 mainchan
->u
.v2
.outbuflen
+= inlen
;
2449 * Try to send data on the channel if we can. (FIXME:
2450 * on _all_ channels.)
2452 while (mainchan
->u
.v2
.remwindow
> 0 &&
2453 mainchan
->u
.v2
.outbuflen
> 0) {
2454 unsigned len
= mainchan
->u
.v2
.remwindow
;
2455 if (len
> mainchan
->u
.v2
.outbuflen
)
2456 len
= mainchan
->u
.v2
.outbuflen
;
2457 if (len
> mainchan
->u
.v2
.remmaxpkt
)
2458 len
= mainchan
->u
.v2
.remmaxpkt
;
2459 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA
);
2460 ssh2_pkt_adduint32(mainchan
->remoteid
);
2461 ssh2_pkt_addstring_start();
2462 ssh2_pkt_addstring_data(mainchan
->u
.v2
.outbuffer
, len
);
2464 mainchan
->u
.v2
.outbuflen
-= len
;
2465 memmove(mainchan
->u
.v2
.outbuffer
, mainchan
->u
.v2
.outbuffer
+len
,
2466 mainchan
->u
.v2
.outbuflen
);
2467 mainchan
->u
.v2
.remwindow
-= len
;
2476 * Handle the top-level SSH2 protocol.
2478 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
)
2480 if (do_ssh2_transport(in
, inlen
, ispkt
) == 0)
2482 do_ssh2_authconn(in
, inlen
, ispkt
);
2486 * Called to set up the connection.
2488 * Returns an error message, or NULL on success.
2490 static char *ssh_init (char *host
, int port
, char **realhost
) {
2494 if(crypto_startup() == 0)
2495 return "Microsoft high encryption pack not installed!";
2500 p
= connect_to_host(host
, port
, realhost
);
2508 * Called to send data down the Telnet connection.
2510 static void ssh_send (char *buf
, int len
) {
2514 ssh_protocol(buf
, len
, 0);
2518 * Called to set the size of the window from Telnet's POV.
2520 static void ssh_size(void) {
2521 switch (ssh_state
) {
2522 case SSH_STATE_BEFORE_SIZE
:
2523 case SSH_STATE_CLOSED
:
2524 break; /* do nothing */
2525 case SSH_STATE_INTERMED
:
2526 size_needed
= TRUE
; /* buffer for later */
2528 case SSH_STATE_SESSION
:
2530 send_packet(SSH1_CMSG_WINDOW_SIZE
,
2531 PKT_INT
, rows
, PKT_INT
, cols
,
2532 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
2538 * Send Telnet special codes. TS_EOF is useful for `plink', so you
2539 * can send an EOF and collect resulting output (e.g. `plink
2542 static void ssh_special (Telnet_Special code
) {
2543 if (code
== TS_EOF
) {
2544 if (ssh_version
== 1) {
2545 send_packet(SSH1_CMSG_EOF
, PKT_END
);
2547 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF
);
2548 ssh2_pkt_adduint32(mainchan
->remoteid
);
2551 logevent("Sent EOF message");
2552 } else if (code
== TS_PING
) {
2553 if (ssh_version
== 1) {
2554 send_packet(SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
2556 ssh2_pkt_init(SSH2_MSG_IGNORE
);
2557 ssh2_pkt_addstring_start();
2565 static Socket
ssh_socket(void) { return s
; }
2567 static int ssh_sendok(void) { return ssh_send_ok
; }
2569 Backend ssh_backend
= {