24 #define logevent(s) { logevent(s); \
25 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
26 fprintf(stderr, "%s\n", s); }
28 #define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, closesocket(s), \
29 s = INVALID_SOCKET, connection_fatal msg )
31 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
32 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
33 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
34 #define SSH1_CMSG_USER 4 /* 0x4 */
35 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
36 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
37 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
38 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
39 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
40 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
41 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
42 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
43 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
44 #define SSH1_SMSG_FAILURE 15 /* 0xf */
45 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
46 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
47 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
48 #define SSH1_CMSG_EOF 19 /* 0x13 */
49 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
50 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
51 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
52 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
53 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
54 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
55 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
56 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
57 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
58 #define SSH1_MSG_IGNORE 32 /* 0x20 */
59 #define SSH1_MSG_DEBUG 36 /* 0x24 */
60 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
61 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
62 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
63 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
64 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
65 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
67 #define SSH1_AUTH_TIS 5 /* 0x5 */
68 #define SSH1_AUTH_CCARD 16 /* 0x10 */
70 #define SSH_AGENTC_REQUEST_RSA_IDENTITIES 1 /* 0x1 */
71 #define SSH_AGENT_RSA_IDENTITIES_ANSWER 2 /* 0x2 */
72 #define SSH_AGENTC_RSA_CHALLENGE 3 /* 0x3 */
73 #define SSH_AGENT_RSA_RESPONSE 4 /* 0x4 */
74 #define SSH_AGENT_FAILURE 5 /* 0x5 */
75 #define SSH_AGENT_SUCCESS 6 /* 0x6 */
76 #define SSH_AGENTC_ADD_RSA_IDENTITY 7 /* 0x7 */
77 #define SSH_AGENTC_REMOVE_RSA_IDENTITY 8 /* 0x8 */
79 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
80 #define SSH2_MSG_IGNORE 2 /* 0x2 */
81 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
82 #define SSH2_MSG_DEBUG 4 /* 0x4 */
83 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
84 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
85 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
86 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
87 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
88 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
89 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
90 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
91 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
92 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
93 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
94 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
95 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
96 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
97 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
98 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
99 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
100 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
101 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
102 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
103 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
104 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
105 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
106 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
107 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
108 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
110 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
111 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
112 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
113 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
115 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
117 #define GET_32BIT(cp) \
118 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
119 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
120 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
121 ((unsigned long)(unsigned char)(cp)[3]))
123 #define PUT_32BIT(cp, value) { \
124 (cp)[0] = (unsigned char)((value) >> 24); \
125 (cp)[1] = (unsigned char)((value) >> 16); \
126 (cp)[2] = (unsigned char)((value) >> 8); \
127 (cp)[3] = (unsigned char)(value); }
129 enum { PKT_END
, PKT_INT
, PKT_CHAR
, PKT_DATA
, PKT_STR
, PKT_BIGNUM
};
131 /* Coroutine mechanics for the sillier bits of the code */
132 #define crBegin1 static int crLine = 0;
133 #define crBegin2 switch(crLine) { case 0:;
134 #define crBegin crBegin1; crBegin2;
135 #define crFinish(z) } crLine = 0; return (z)
136 #define crFinishV } crLine = 0; return
137 #define crReturn(z) \
139 crLine=__LINE__; return (z); case __LINE__:;\
143 crLine=__LINE__; return; case __LINE__:;\
145 #define crStop(z) do{ crLine = 0; return (z); }while(0)
146 #define crStopV do{ crLine = 0; return; }while(0)
147 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
148 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
150 extern const struct ssh_cipher ssh_3des
;
151 extern const struct ssh_cipher ssh_3des_ssh2
;
152 extern const struct ssh_cipher ssh_des
;
153 extern const struct ssh_cipher ssh_blowfish_ssh1
;
154 extern const struct ssh_cipher ssh_blowfish_ssh2
;
157 * Ciphers for SSH2. We miss out single-DES because it isn't
158 * supported; also 3DES and Blowfish are both done differently from
159 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
160 * endianness and different-sized keys.)
162 const static struct ssh_cipher
*ciphers
[] = { &ssh_blowfish_ssh2
, &ssh_3des_ssh2
};
164 extern const struct ssh_kex ssh_diffiehellman
;
165 const static struct ssh_kex
*kex_algs
[] = { &ssh_diffiehellman
};
167 extern const struct ssh_hostkey ssh_dss
;
168 const static struct ssh_hostkey
*hostkey_algs
[] = { &ssh_dss
};
170 extern const struct ssh_mac ssh_md5
, ssh_sha1
, ssh_sha1_buggy
;
172 static void nullmac_key(unsigned char *key
) { }
173 static void nullmac_generate(unsigned char *blk
, int len
, unsigned long seq
) { }
174 static int nullmac_verify(unsigned char *blk
, int len
, unsigned long seq
) { return 1; }
175 const static struct ssh_mac ssh_mac_none
= {
176 nullmac_key
, nullmac_key
, nullmac_generate
, nullmac_verify
, "none", 0
178 const static struct ssh_mac
*macs
[] = {
179 &ssh_sha1
, &ssh_md5
, &ssh_mac_none
};
180 const static struct ssh_mac
*buggymacs
[] = {
181 &ssh_sha1_buggy
, &ssh_md5
, &ssh_mac_none
};
183 const static struct ssh_compress ssh_comp_none
= {
186 const static struct ssh_compress
*compressions
[] = { &ssh_comp_none
};
189 * 2-3-4 tree storing channels.
192 unsigned remoteid
, localid
;
196 struct ssh_agent_channel
{
197 unsigned char *message
;
198 unsigned char msglen
[4];
199 int lensofar
, totallen
;
201 struct ssh2_data_channel
{
202 unsigned char *outbuffer
;
203 unsigned outbuflen
, outbufsize
;
204 unsigned remwindow
, remmaxpkt
;
218 static SHA_State exhash
;
220 static SOCKET s
= INVALID_SOCKET
;
222 static unsigned char session_key
[32];
223 static const struct ssh_cipher
*cipher
= NULL
;
224 static const struct ssh_cipher
*cscipher
= NULL
;
225 static const struct ssh_cipher
*sccipher
= NULL
;
226 static const struct ssh_mac
*csmac
= NULL
;
227 static const struct ssh_mac
*scmac
= NULL
;
228 static const struct ssh_compress
*cscomp
= NULL
;
229 static const struct ssh_compress
*sccomp
= NULL
;
230 static const struct ssh_kex
*kex
= NULL
;
231 static const struct ssh_hostkey
*hostkey
= NULL
;
232 int (*ssh_get_password
)(const char *prompt
, char *str
, int maxlen
) = NULL
;
234 static char *savedhost
;
235 static int savedport
;
236 static int ssh_send_ok
;
238 static tree234
*ssh_channels
; /* indexed by local id */
239 static struct ssh_channel
*mainchan
; /* primary session channel */
242 SSH_STATE_BEFORE_SIZE
,
246 } ssh_state
= SSH_STATE_BEFORE_SIZE
;
248 static int size_needed
= FALSE
;
250 static struct Packet pktin
= { 0, 0, NULL
, NULL
, 0 };
251 static struct Packet pktout
= { 0, 0, NULL
, NULL
, 0 };
253 static int ssh_version
;
254 static void (*ssh_protocol
)(unsigned char *in
, int inlen
, int ispkt
);
255 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
);
256 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
);
257 static void ssh_size(void);
259 static int (*s_rdpkt
)(unsigned char **data
, int *datalen
);
261 static struct rdpkt1_state_tag
{
262 long len
, pad
, biglen
, to_read
;
263 unsigned long realcrc
, gotcrc
;
269 static struct rdpkt2_state_tag
{
270 long len
, pad
, payload
, packetlen
, maclen
;
273 unsigned long incoming_sequence
;
276 static int ssh_channelcmp(void *av
, void *bv
) {
277 struct ssh_channel
*a
= (struct ssh_channel
*)av
;
278 struct ssh_channel
*b
= (struct ssh_channel
*)bv
;
279 if (a
->localid
< b
->localid
) return -1;
280 if (a
->localid
> b
->localid
) return +1;
283 static int ssh_channelfind(void *av
, void *bv
) {
284 unsigned *a
= (unsigned *)av
;
285 struct ssh_channel
*b
= (struct ssh_channel
*)bv
;
286 if (*a
< b
->localid
) return -1;
287 if (*a
> b
->localid
) return +1;
291 static void s_write (char *buf
, int len
) {
293 int i
= send (s
, buf
, len
, 0);
296 bombout(("Lost connection while sending"));
304 static int s_read (char *buf
, int len
) {
307 int i
= recv (s
, buf
, len
, 0);
310 len
-= i
, buf
+= i
, ret
+= i
;
317 static void c_write (char *buf
, int len
) {
318 if ((flags
& FLAG_STDERR
)) {
320 for (i
= 0; i
< len
; i
++)
322 fputc(buf
[i
], stderr
);
325 from_backend(1, buf
, len
);
329 * Collect incoming data in the incoming packet buffer.
330 * Decipher and verify the packet when it is completely read.
331 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
332 * Update the *data and *datalen variables.
333 * Return the additional nr of bytes needed, or 0 when
334 * a complete packet is available.
336 static int ssh1_rdpkt(unsigned char **data
, int *datalen
)
338 struct rdpkt1_state_tag
*st
= &rdpkt1_state
;
347 for (st
->i
= st
->len
= 0; st
->i
< 4; st
->i
++) {
348 while ((*datalen
) == 0)
350 st
->len
= (st
->len
<< 8) + **data
;
351 (*data
)++, (*datalen
)--;
355 if (st
->len
== 0x52656d6f) { /* "Remo"te server has closed ... */
356 st
->len
= 0x300; /* big enough to carry to end */
360 st
->pad
= 8 - (st
->len
% 8);
361 st
->biglen
= st
->len
+ st
->pad
;
362 pktin
.length
= st
->len
- 5;
364 if (pktin
.maxlen
< st
->biglen
) {
365 pktin
.maxlen
= st
->biglen
;
366 pktin
.data
= (pktin
.data
== NULL ?
malloc(st
->biglen
+APIEXTRA
) :
367 realloc(pktin
.data
, st
->biglen
+APIEXTRA
));
369 fatalbox("Out of memory");
372 st
->to_read
= st
->biglen
;
374 while (st
->to_read
> 0) {
375 st
->chunk
= st
->to_read
;
376 while ((*datalen
) == 0)
377 crReturn(st
->to_read
);
378 if (st
->chunk
> (*datalen
))
379 st
->chunk
= (*datalen
);
380 memcpy(st
->p
, *data
, st
->chunk
);
382 *datalen
-= st
->chunk
;
384 st
->to_read
-= st
->chunk
;
388 cipher
->decrypt(pktin
.data
, st
->biglen
);
390 debug(("Got packet len=%d pad=%d\r\n", st
->len
, st
->pad
));
391 for (st
->i
= 0; st
->i
< st
->biglen
; st
->i
++)
392 debug((" %02x", (unsigned char)pktin
.data
[st
->i
]));
396 pktin
.type
= pktin
.data
[st
->pad
];
397 pktin
.body
= pktin
.data
+ st
->pad
+ 1;
399 st
->realcrc
= crc32(pktin
.data
, st
->biglen
-4);
400 st
->gotcrc
= GET_32BIT(pktin
.data
+st
->biglen
-4);
401 if (st
->gotcrc
!= st
->realcrc
) {
402 bombout(("Incorrect CRC received on packet"));
406 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
407 pktin
.type
== SSH1_SMSG_STDERR_DATA
||
408 pktin
.type
== SSH1_MSG_DEBUG
||
409 pktin
.type
== SSH1_SMSG_AUTH_TIS_CHALLENGE
||
410 pktin
.type
== SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
411 long strlen
= GET_32BIT(pktin
.body
);
412 if (strlen
+ 4 != pktin
.length
) {
413 bombout(("Received data packet with bogus string length"));
418 if (pktin
.type
== SSH1_MSG_DEBUG
) {
419 /* log debug message */
421 int strlen
= GET_32BIT(pktin
.body
);
422 strcpy(buf
, "Remote: ");
423 if (strlen
> 70) strlen
= 70;
424 memcpy(buf
+8, pktin
.body
+4, strlen
);
425 buf
[8+strlen
] = '\0';
428 } else if (pktin
.type
== SSH1_MSG_IGNORE
) {
436 static int ssh2_rdpkt(unsigned char **data
, int *datalen
)
438 struct rdpkt2_state_tag
*st
= &rdpkt2_state
;
446 st
->cipherblk
= sccipher
->blksize
;
449 if (st
->cipherblk
< 8)
452 if (pktin
.maxlen
< st
->cipherblk
) {
453 pktin
.maxlen
= st
->cipherblk
;
454 pktin
.data
= (pktin
.data
== NULL ?
malloc(st
->cipherblk
+APIEXTRA
) :
455 realloc(pktin
.data
, st
->cipherblk
+APIEXTRA
));
457 fatalbox("Out of memory");
461 * Acquire and decrypt the first block of the packet. This will
462 * contain the length and padding details.
464 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
465 while ((*datalen
) == 0)
466 crReturn(st
->cipherblk
-st
->i
);
467 pktin
.data
[st
->i
] = *(*data
)++;
471 if (!memcmp(pktin
.data
, "Remo", 4)) {/* "Remo"te server has closed ... */
476 sccipher
->decrypt(pktin
.data
, st
->cipherblk
);
479 * Now get the length and padding figures.
481 st
->len
= GET_32BIT(pktin
.data
);
482 st
->pad
= pktin
.data
[4];
485 * This enables us to deduce the payload length.
487 st
->payload
= st
->len
- st
->pad
- 1;
489 pktin
.length
= st
->payload
+ 5;
492 * So now we can work out the total packet length.
494 st
->packetlen
= st
->len
+ 4;
495 st
->maclen
= scmac ? scmac
->len
: 0;
498 * Adjust memory allocation if packet is too big.
500 if (pktin
.maxlen
< st
->packetlen
+st
->maclen
) {
501 pktin
.maxlen
= st
->packetlen
+st
->maclen
;
502 pktin
.data
= (pktin
.data
== NULL ?
malloc(pktin
.maxlen
+APIEXTRA
) :
503 realloc(pktin
.data
, pktin
.maxlen
+APIEXTRA
));
505 fatalbox("Out of memory");
509 * Read and decrypt the remainder of the packet.
511 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
; st
->i
++) {
512 while ((*datalen
) == 0)
513 crReturn(st
->packetlen
+ st
->maclen
- st
->i
);
514 pktin
.data
[st
->i
] = *(*data
)++;
517 /* Decrypt everything _except_ the MAC. */
519 sccipher
->decrypt(pktin
.data
+ st
->cipherblk
,
520 st
->packetlen
- st
->cipherblk
);
523 debug(("Got packet len=%d pad=%d\r\n", st
->len
, st
->pad
));
524 for (st
->i
= 0; st
->i
< st
->packetlen
; st
->i
++)
525 debug((" %02x", (unsigned char)pktin
.data
[st
->i
]));
532 if (scmac
&& !scmac
->verify(pktin
.data
, st
->len
+4, st
->incoming_sequence
)) {
533 bombout(("Incorrect MAC received on packet"));
536 st
->incoming_sequence
++; /* whether or not we MACed */
539 pktin
.type
= pktin
.data
[5];
541 if (pktin
.type
== SSH2_MSG_IGNORE
|| pktin
.type
== SSH2_MSG_DEBUG
)
542 goto next_packet
; /* FIXME: print DEBUG message */
547 static void ssh_gotdata(unsigned char *data
, int datalen
)
549 while (datalen
> 0) {
550 if ( s_rdpkt(&data
, &datalen
) == 0 ) {
551 ssh_protocol(NULL
, 0, 1);
552 if (ssh_state
== SSH_STATE_CLOSED
) {
560 static void s_wrpkt_start(int type
, int len
) {
563 len
+= 5; /* type and CRC */
567 pktout
.length
= len
-5;
568 if (pktout
.maxlen
< biglen
) {
569 pktout
.maxlen
= biglen
;
571 /* Allocate enough buffer space for extra block
572 * for MS CryptEncrypt() */
573 pktout
.data
= (pktout
.data
== NULL ?
malloc(biglen
+12) :
574 realloc(pktout
.data
, biglen
+12));
576 pktout
.data
= (pktout
.data
== NULL ?
malloc(biglen
+4) :
577 realloc(pktout
.data
, biglen
+4));
580 fatalbox("Out of memory");
584 pktout
.body
= pktout
.data
+4+pad
+1;
587 static void s_wrpkt(void) {
588 int pad
, len
, biglen
, i
;
591 len
= pktout
.length
+ 5; /* type and CRC */
595 pktout
.body
[-1] = pktout
.type
;
596 for (i
=0; i
<pad
; i
++)
597 pktout
.data
[i
+4] = random_byte();
598 crc
= crc32(pktout
.data
+4, biglen
-4);
599 PUT_32BIT(pktout
.data
+biglen
, crc
);
600 PUT_32BIT(pktout
.data
, len
);
603 debug(("Sending packet len=%d\r\n", biglen
+4));
604 for (i
= 0; i
< biglen
+4; i
++)
605 debug((" %02x", (unsigned char)pktout
.data
[i
]));
609 cipher
->encrypt(pktout
.data
+4, biglen
);
611 s_write(pktout
.data
, biglen
+4);
615 * Construct a packet with the specified contents and
616 * send it to the server.
618 static void send_packet(int pkttype
, ...)
621 unsigned char *p
, *argp
, argchar
;
622 unsigned long argint
;
623 int pktlen
, argtype
, arglen
;
627 va_start(args
, pkttype
);
628 while ((argtype
= va_arg(args
, int)) != PKT_END
) {
631 (void) va_arg(args
, int);
635 (void) va_arg(args
, char);
639 (void) va_arg(args
, unsigned char *);
640 arglen
= va_arg(args
, int);
644 argp
= va_arg(args
, unsigned char *);
645 arglen
= strlen(argp
);
646 pktlen
+= 4 + arglen
;
649 bn
= va_arg(args
, Bignum
);
650 pktlen
+= ssh1_bignum_length(bn
);
658 s_wrpkt_start(pkttype
, pktlen
);
661 va_start(args
, pkttype
);
662 while ((argtype
= va_arg(args
, int)) != PKT_END
) {
665 argint
= va_arg(args
, int);
666 PUT_32BIT(p
, argint
);
670 argchar
= va_arg(args
, unsigned char);
675 argp
= va_arg(args
, unsigned char *);
676 arglen
= va_arg(args
, int);
677 memcpy(p
, argp
, arglen
);
681 argp
= va_arg(args
, unsigned char *);
682 arglen
= strlen(argp
);
683 PUT_32BIT(p
, arglen
);
684 memcpy(p
+ 4, argp
, arglen
);
688 bn
= va_arg(args
, Bignum
);
689 p
+= ssh1_write_bignum(p
, bn
);
700 * Connect to specified host and port.
701 * Returns an error message, or NULL on success.
702 * Also places the canonical host name into `realhost'.
704 static char *connect_to_host(char *host
, int port
, char **realhost
)
714 savedhost
= malloc(1+strlen(host
));
716 fatalbox("Out of memory");
717 strcpy(savedhost
, host
);
720 port
= 22; /* default ssh port */
733 if ( (a
= inet_addr(host
)) == (unsigned long) INADDR_NONE
) {
734 if ( (h
= gethostbyname(host
)) == NULL
)
735 switch (WSAGetLastError()) {
736 case WSAENETDOWN
: return "Network is down";
737 case WSAHOST_NOT_FOUND
: case WSANO_DATA
:
738 return "Host does not exist";
739 case WSATRY_AGAIN
: return "Host not found";
740 default: return "gethostbyname: unknown error";
742 memcpy (&a
, h
->h_addr
, sizeof(a
));
743 *realhost
= h
->h_name
;
754 s
= socket(AF_INET
, SOCK_STREAM
, 0);
755 if (s
== INVALID_SOCKET
)
756 switch (WSAGetLastError()) {
757 case WSAENETDOWN
: return "Network is down";
758 case WSAEAFNOSUPPORT
: return "TCP/IP support not present";
759 default: return "socket(): unknown error";
763 * Bind to local address.
765 addr
.sin_family
= AF_INET
;
766 addr
.sin_addr
.s_addr
= htonl(INADDR_ANY
);
767 addr
.sin_port
= htons(0);
768 if (bind (s
, (struct sockaddr
*)&addr
, sizeof(addr
)) == SOCKET_ERROR
)
769 switch (WSAGetLastError()) {
770 case WSAENETDOWN
: return "Network is down";
771 default: return "bind(): unknown error";
775 * Connect to remote address.
777 addr
.sin_addr
.s_addr
= htonl(a
);
778 addr
.sin_port
= htons((short)port
);
779 if (connect (s
, (struct sockaddr
*)&addr
, sizeof(addr
)) == SOCKET_ERROR
)
780 switch (WSAGetLastError()) {
781 case WSAENETDOWN
: return "Network is down";
782 case WSAECONNREFUSED
: return "Connection refused";
783 case WSAENETUNREACH
: return "Network is unreachable";
784 case WSAEHOSTUNREACH
: return "No route to host";
785 default: return "connect(): unknown error";
789 send(s
, "connect ", 8, 0);
790 send(s
, FWhost
, strlen(FWhost
), 0);
793 sprintf(buf
, " %d\n", FWport
);
794 send (s
, buf
, strlen(buf
), 0);
801 static int ssh_versioncmp(char *a
, char *b
) {
803 unsigned long av
, bv
;
805 av
= strtoul(a
, &ae
, 10);
806 bv
= strtoul(b
, &be
, 10);
807 if (av
!= bv
) return (av
< bv ?
-1 : +1);
808 if (*ae
== '.') ae
++;
809 if (*be
== '.') be
++;
810 av
= strtoul(ae
, &ae
, 10);
811 bv
= strtoul(be
, &be
, 10);
812 if (av
!= bv
) return (av
< bv ?
-1 : +1);
818 * Utility routine for putting an SSH-protocol `string' into a SHA
822 static void sha_string(SHA_State
*s
, void *str
, int len
) {
823 unsigned char lenblk
[4];
824 PUT_32BIT(lenblk
, len
);
825 SHA_Bytes(s
, lenblk
, 4);
826 SHA_Bytes(s
, str
, len
);
830 * SSH2 packet construction functions.
832 static void ssh2_pkt_adddata(void *data
, int len
) {
833 pktout
.length
+= len
;
834 if (pktout
.maxlen
< pktout
.length
) {
835 pktout
.maxlen
= pktout
.length
+ 256;
836 pktout
.data
= (pktout
.data
== NULL ?
malloc(pktout
.maxlen
+APIEXTRA
) :
837 realloc(pktout
.data
, pktout
.maxlen
+APIEXTRA
));
839 fatalbox("Out of memory");
841 memcpy(pktout
.data
+pktout
.length
-len
, data
, len
);
843 static void ssh2_pkt_addbyte(unsigned char byte
) {
844 ssh2_pkt_adddata(&byte
, 1);
846 static void ssh2_pkt_init(int pkt_type
) {
848 ssh2_pkt_addbyte((unsigned char)pkt_type
);
850 static void ssh2_pkt_addbool(unsigned char value
) {
851 ssh2_pkt_adddata(&value
, 1);
853 static void ssh2_pkt_adduint32(unsigned long value
) {
856 ssh2_pkt_adddata(x
, 4);
858 static void ssh2_pkt_addstring_start(void) {
859 ssh2_pkt_adduint32(0);
860 pktout
.savedpos
= pktout
.length
;
862 static void ssh2_pkt_addstring_str(char *data
) {
863 ssh2_pkt_adddata(data
, strlen(data
));
864 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
865 pktout
.length
- pktout
.savedpos
);
867 static void ssh2_pkt_addstring_data(char *data
, int len
) {
868 ssh2_pkt_adddata(data
, len
);
869 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
870 pktout
.length
- pktout
.savedpos
);
872 static void ssh2_pkt_addstring(char *data
) {
873 ssh2_pkt_addstring_start();
874 ssh2_pkt_addstring_str(data
);
876 static char *ssh2_mpint_fmt(Bignum b
, int *len
) {
879 p
= malloc(n
* 2 + 1);
881 fatalbox("out of memory");
883 for (i
= 0; i
< n
; i
++) {
884 p
[i
*2+1] = (b
[n
-i
] >> 8) & 0xFF;
885 p
[i
*2+2] = (b
[n
-i
] ) & 0xFF;
888 while (p
[i
] == 0 && (p
[i
+1] & 0x80) == 0)
890 memmove(p
, p
+i
, n
*2+1-i
);
894 static void ssh2_pkt_addmp(Bignum b
) {
897 p
= ssh2_mpint_fmt(b
, &len
);
898 ssh2_pkt_addstring_start();
899 ssh2_pkt_addstring_data(p
, len
);
902 static void ssh2_pkt_send(void) {
903 int cipherblk
, maclen
, padding
, i
;
904 static unsigned long outgoing_sequence
= 0;
907 * Add padding. At least four bytes, and must also bring total
908 * length (minus MAC) up to a multiple of the block size.
910 cipherblk
= cipher ? cipher
->blksize
: 8; /* block size */
911 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
913 padding
+= (cipherblk
- (pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
914 pktout
.data
[4] = padding
;
915 for (i
= 0; i
< padding
; i
++)
916 pktout
.data
[pktout
.length
+ i
] = random_byte();
917 PUT_32BIT(pktout
.data
, pktout
.length
+ padding
- 4);
919 csmac
->generate(pktout
.data
, pktout
.length
+ padding
,
921 outgoing_sequence
++; /* whether or not we MACed */
924 debug(("Sending packet len=%d\r\n", pktout
.length
+padding
));
925 for (i
= 0; i
< pktout
.length
+padding
; i
++)
926 debug((" %02x", (unsigned char)pktout
.data
[i
]));
931 cscipher
->encrypt(pktout
.data
, pktout
.length
+ padding
);
932 maclen
= csmac ? csmac
->len
: 0;
934 s_write(pktout
.data
, pktout
.length
+ padding
+ maclen
);
938 void bndebug(char *string
, Bignum b
) {
941 p
= ssh2_mpint_fmt(b
, &len
);
942 debug(("%s", string
));
943 for (i
= 0; i
< len
; i
++)
944 debug((" %02x", p
[i
]));
950 static void sha_mpint(SHA_State
*s
, Bignum b
) {
953 p
= ssh2_mpint_fmt(b
, &len
);
954 sha_string(s
, p
, len
);
959 * SSH2 packet decode functions.
961 static unsigned long ssh2_pkt_getuint32(void) {
963 if (pktin
.length
- pktin
.savedpos
< 4)
964 return 0; /* arrgh, no way to decline (FIXME?) */
965 value
= GET_32BIT(pktin
.data
+pktin
.savedpos
);
969 static void ssh2_pkt_getstring(char **p
, int *length
) {
971 if (pktin
.length
- pktin
.savedpos
< 4)
973 *length
= GET_32BIT(pktin
.data
+pktin
.savedpos
);
975 if (pktin
.length
- pktin
.savedpos
< *length
)
977 *p
= pktin
.data
+pktin
.savedpos
;
978 pktin
.savedpos
+= *length
;
980 static Bignum
ssh2_pkt_getmp(void) {
985 ssh2_pkt_getstring(&p
, &length
);
989 bombout(("internal error: Can't handle negative mpints"));
992 b
= newbn((length
+1)/2);
993 for (i
= 0; i
< length
; i
++) {
996 b
[j
/2+1] |= ((unsigned char)p
[i
]) << 8;
998 b
[j
/2+1] |= ((unsigned char)p
[i
]);
1003 static int do_ssh_init(void) {
1007 char vlog
[sizeof(vstring
)+20];
1012 while (s_read(&c
, 1) == 1) {
1013 if (c
== 'S' && i
< 2) i
++;
1014 else if (c
== 'S' && i
== 2) i
= 2;
1015 else if (c
== 'H' && i
== 2) break;
1019 if (s_read(&c
,1) != 1 || c
!= 'S') return 0;
1020 if (s_read(&c
,1) != 1 || c
!= 'S') return 0;
1021 if (s_read(&c
,1) != 1 || c
!= 'H') return 0;
1023 strcpy(vstring
, "SSH-");
1025 if (s_read(&c
,1) != 1 || c
!= '-') return 0;
1028 if (s_read(&c
,1) != 1)
1030 if (vsp
< vstring
+sizeof(vstring
)-1)
1036 } else if (i
< sizeof(version
)-1)
1043 rdpkt2_state
.incoming_sequence
= 0;
1046 sprintf(vlog
, "Server version: %s", vstring
);
1047 vlog
[strcspn(vlog
, "\r\n")] = '\0';
1051 * Server version "1.99" means we can choose whether we use v1
1052 * or v2 protocol. Choice is based on cfg.sshprot.
1054 if (ssh_versioncmp(version
, cfg
.sshprot
== 1 ?
"2.0" : "1.99") >= 0) {
1056 * This is a v2 server. Begin v2 protocol.
1058 char *verstring
= "SSH-2.0-PuTTY";
1061 * Hash our version string and their version string.
1063 sha_string(&exhash
, verstring
, strlen(verstring
));
1064 sha_string(&exhash
, vstring
, strcspn(vstring
, "\r\n"));
1065 sprintf(vstring
, "%s\n", verstring
);
1066 sprintf(vlog
, "We claim version: %s", verstring
);
1068 logevent("Using SSH protocol version 2");
1069 s_write(vstring
, strlen(vstring
));
1070 ssh_protocol
= ssh2_protocol
;
1072 s_rdpkt
= ssh2_rdpkt
;
1075 * This is a v1 server. Begin v1 protocol.
1077 sprintf(vstring
, "SSH-%s-PuTTY\n",
1078 (ssh_versioncmp(version
, "1.5") <= 0 ? version
: "1.5"));
1079 sprintf(vlog
, "We claim version: %s", vstring
);
1080 vlog
[strcspn(vlog
, "\r\n")] = '\0';
1082 logevent("Using SSH protocol version 1");
1083 s_write(vstring
, strlen(vstring
));
1084 ssh_protocol
= ssh1_protocol
;
1086 s_rdpkt
= ssh1_rdpkt
;
1093 * Handle the key exchange and user authentication phases.
1095 static int do_ssh1_login(unsigned char *in
, int inlen
, int ispkt
)
1098 unsigned char *rsabuf
, *keystr1
, *keystr2
;
1099 unsigned char cookie
[8];
1100 struct RSAKey servkey
, hostkey
;
1101 struct MD5Context md5c
;
1102 static unsigned long supported_ciphers_mask
, supported_auths_mask
;
1103 static int tried_publickey
;
1104 static unsigned char session_id
[16];
1106 static char username
[100];
1110 if (!ispkt
) crWaitUntil(ispkt
);
1112 if (pktin
.type
!= SSH1_SMSG_PUBLIC_KEY
) {
1113 bombout(("Public key packet not received"));
1117 logevent("Received public keys");
1119 memcpy(cookie
, pktin
.body
, 8);
1121 i
= makekey(pktin
.body
+8, &servkey
, &keystr1
, 0);
1122 j
= makekey(pktin
.body
+8+i
, &hostkey
, &keystr2
, 0);
1125 * Log the host key fingerprint.
1129 logevent("Host key fingerprint is:");
1130 strcpy(logmsg
, " ");
1131 hostkey
.comment
= NULL
;
1132 rsa_fingerprint(logmsg
+strlen(logmsg
), sizeof(logmsg
)-strlen(logmsg
),
1137 supported_ciphers_mask
= GET_32BIT(pktin
.body
+12+i
+j
);
1138 supported_auths_mask
= GET_32BIT(pktin
.body
+16+i
+j
);
1141 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
1142 MD5Update(&md5c
, keystr1
, servkey
.bytes
);
1143 MD5Update(&md5c
, pktin
.body
, 8);
1144 MD5Final(session_id
, &md5c
);
1146 for (i
=0; i
<32; i
++)
1147 session_key
[i
] = random_byte();
1149 len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
1151 rsabuf
= malloc(len
);
1153 fatalbox("Out of memory");
1156 * Verify the host key.
1160 * First format the key into a string.
1162 int len
= rsastr_len(&hostkey
);
1163 char fingerprint
[100];
1164 char *keystr
= malloc(len
);
1166 fatalbox("Out of memory");
1167 rsastr_fmt(keystr
, &hostkey
);
1168 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
1169 verify_ssh_host_key(savedhost
, savedport
, "rsa", keystr
, fingerprint
);
1173 for (i
=0; i
<32; i
++) {
1174 rsabuf
[i
] = session_key
[i
];
1176 rsabuf
[i
] ^= session_id
[i
];
1179 if (hostkey
.bytes
> servkey
.bytes
) {
1180 rsaencrypt(rsabuf
, 32, &servkey
);
1181 rsaencrypt(rsabuf
, servkey
.bytes
, &hostkey
);
1183 rsaencrypt(rsabuf
, 32, &hostkey
);
1184 rsaencrypt(rsabuf
, hostkey
.bytes
, &servkey
);
1187 logevent("Encrypted session key");
1189 cipher_type
= cfg
.cipher
== CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH
:
1190 cfg
.cipher
== CIPHER_DES ? SSH_CIPHER_DES
:
1192 if ((supported_ciphers_mask
& (1 << cipher_type
)) == 0) {
1193 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1194 cipher_type
= SSH_CIPHER_3DES
;
1196 switch (cipher_type
) {
1197 case SSH_CIPHER_3DES
: logevent("Using 3DES encryption"); break;
1198 case SSH_CIPHER_DES
: logevent("Using single-DES encryption"); break;
1199 case SSH_CIPHER_BLOWFISH
: logevent("Using Blowfish encryption"); break;
1202 send_packet(SSH1_CMSG_SESSION_KEY
,
1203 PKT_CHAR
, cipher_type
,
1204 PKT_DATA
, cookie
, 8,
1205 PKT_CHAR
, (len
*8) >> 8, PKT_CHAR
, (len
*8) & 0xFF,
1206 PKT_DATA
, rsabuf
, len
,
1210 logevent("Trying to enable encryption...");
1214 cipher
= cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
1215 cipher_type
== SSH_CIPHER_DES ?
&ssh_des
:
1217 cipher
->sesskey(session_key
);
1221 if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1222 bombout(("Encryption not successfully enabled"));
1226 logevent("Successfully started encryption");
1232 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
1233 c_write("login as: ", 10);
1236 crWaitUntil(!ispkt
);
1237 while (inlen
--) switch (c
= *in
++) {
1244 c_write("\b \b", 3);
1250 c_write("\b \b", 3);
1259 if (((c
>= ' ' && c
<= '~') ||
1260 ((unsigned char)c
>= 160)) && pos
< 40) {
1261 username
[pos
++] = c
;
1268 username
[strcspn(username
, "\n\r")] = '\0';
1271 strncpy(username
, cfg
.username
, 99);
1272 username
[99] = '\0';
1273 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
1274 sprintf(stuff
, "Sent username \"%s\".\r\n", username
);
1275 c_write(stuff
, strlen(stuff
));
1279 send_packet(SSH1_CMSG_USER
, PKT_STR
, username
, PKT_END
);
1281 char userlog
[20+sizeof(username
)];
1282 sprintf(userlog
, "Sent username \"%s\"", username
);
1289 tried_publickey
= 0;
1291 while (pktin
.type
== SSH1_SMSG_FAILURE
) {
1292 static char password
[100];
1293 static char prompt
[200];
1296 static int pwpkt_type
;
1298 * Show password prompt, having first obtained it via a TIS
1299 * or CryptoCard exchange if we're doing TIS or CryptoCard
1302 pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
1303 if (agent_exists()) {
1305 * Attempt RSA authentication using Pageant.
1307 static unsigned char request
[5], *response
, *p
;
1308 static int responselen
;
1309 static int i
, nkeys
;
1310 static int authed
= FALSE
;
1313 logevent("Pageant is running. Requesting keys.");
1315 /* Request the keys held by the agent. */
1316 PUT_32BIT(request
, 1);
1317 request
[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES
;
1318 agent_query(request
, 5, &r
, &responselen
);
1319 response
= (unsigned char *)r
;
1322 nkeys
= GET_32BIT(p
); p
+= 4;
1323 { char buf
[64]; sprintf(buf
, "Pageant has %d keys", nkeys
);
1325 for (i
= 0; i
< nkeys
; i
++) {
1326 static struct RSAKey key
;
1327 static Bignum challenge
;
1328 static char *commentp
;
1329 static int commentlen
;
1331 { char buf
[64]; sprintf(buf
, "Trying Pageant key #%d", i
);
1334 p
+= ssh1_read_bignum(p
, &key
.exponent
);
1335 p
+= ssh1_read_bignum(p
, &key
.modulus
);
1336 commentlen
= GET_32BIT(p
); p
+= 4;
1337 commentp
= p
; p
+= commentlen
;
1338 send_packet(SSH1_CMSG_AUTH_RSA
,
1339 PKT_BIGNUM
, key
.modulus
, PKT_END
);
1341 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
1342 logevent("Key refused");
1345 logevent("Received RSA challenge");
1346 ssh1_read_bignum(pktin
.body
, &challenge
);
1348 char *agentreq
, *q
, *ret
;
1350 len
= 1 + 4; /* message type, bit count */
1351 len
+= ssh1_bignum_length(key
.exponent
);
1352 len
+= ssh1_bignum_length(key
.modulus
);
1353 len
+= ssh1_bignum_length(challenge
);
1354 len
+= 16; /* session id */
1355 len
+= 4; /* response format */
1356 agentreq
= malloc(4 + len
);
1357 PUT_32BIT(agentreq
, len
);
1359 *q
++ = SSH_AGENTC_RSA_CHALLENGE
;
1360 PUT_32BIT(q
, ssh1_bignum_bitcount(key
.modulus
));
1362 q
+= ssh1_write_bignum(q
, key
.exponent
);
1363 q
+= ssh1_write_bignum(q
, key
.modulus
);
1364 q
+= ssh1_write_bignum(q
, challenge
);
1365 memcpy(q
, session_id
, 16); q
+= 16;
1366 PUT_32BIT(q
, 1); /* response format */
1367 agent_query(agentreq
, len
+4, &ret
, &retlen
);
1370 if (ret
[4] == SSH_AGENT_RSA_RESPONSE
) {
1371 logevent("Sending Pageant's response");
1372 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
1373 PKT_DATA
, ret
+5, 16, PKT_END
);
1376 if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
1377 logevent("Pageant's response accepted");
1378 if (flags
& FLAG_VERBOSE
) {
1379 c_write("Authenticated using RSA key \"",
1381 c_write(commentp
, commentlen
);
1382 c_write("\" from agent\r\n", 14);
1386 logevent("Pageant's response not accepted");
1388 logevent("Pageant failed to answer challenge");
1392 logevent("No reply received from Pageant");
1395 freebn(key
.exponent
);
1396 freebn(key
.modulus
);
1405 if (*cfg
.keyfile
&& !tried_publickey
)
1406 pwpkt_type
= SSH1_CMSG_AUTH_RSA
;
1408 if (pktin
.type
== SSH1_SMSG_FAILURE
&&
1410 (supported_auths_mask
& (1<<SSH1_AUTH_TIS
))) {
1411 pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
1412 logevent("Requested TIS authentication");
1413 send_packet(SSH1_CMSG_AUTH_TIS
, PKT_END
);
1415 if (pktin
.type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
1416 logevent("TIS authentication declined");
1417 if (flags
& FLAG_INTERACTIVE
)
1418 c_write("TIS authentication refused.\r\n", 29);
1420 int challengelen
= ((pktin
.body
[0] << 24) |
1421 (pktin
.body
[1] << 16) |
1422 (pktin
.body
[2] << 8) |
1424 logevent("Received TIS challenge");
1425 if (challengelen
> sizeof(prompt
)-1)
1426 challengelen
= sizeof(prompt
)-1; /* prevent overrun */
1427 memcpy(prompt
, pktin
.body
+4, challengelen
);
1428 prompt
[challengelen
] = '\0';
1431 if (pktin
.type
== SSH1_SMSG_FAILURE
&&
1433 (supported_auths_mask
& (1<<SSH1_AUTH_CCARD
))) {
1434 pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
1435 logevent("Requested CryptoCard authentication");
1436 send_packet(SSH1_CMSG_AUTH_CCARD
, PKT_END
);
1438 if (pktin
.type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
1439 logevent("CryptoCard authentication declined");
1440 c_write("CryptoCard authentication refused.\r\n", 29);
1442 int challengelen
= ((pktin
.body
[0] << 24) |
1443 (pktin
.body
[1] << 16) |
1444 (pktin
.body
[2] << 8) |
1446 logevent("Received CryptoCard challenge");
1447 if (challengelen
> sizeof(prompt
)-1)
1448 challengelen
= sizeof(prompt
)-1; /* prevent overrun */
1449 memcpy(prompt
, pktin
.body
+4, challengelen
);
1450 strncpy(prompt
+ challengelen
, "\r\nResponse : ",
1451 sizeof(prompt
)-challengelen
);
1452 prompt
[sizeof(prompt
)-1] = '\0';
1455 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
1456 sprintf(prompt
, "%.90s@%.90s's password: ",
1457 username
, savedhost
);
1459 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
1460 char *comment
= NULL
;
1461 if (flags
& FLAG_VERBOSE
)
1462 c_write("Trying public key authentication.\r\n", 35);
1463 if (!rsakey_encrypted(cfg
.keyfile
, &comment
)) {
1464 if (flags
& FLAG_VERBOSE
)
1465 c_write("No passphrase required.\r\n", 25);
1468 sprintf(prompt
, "Passphrase for key \"%.100s\": ", comment
);
1472 if (ssh_get_password
) {
1473 if (!ssh_get_password(prompt
, password
, sizeof(password
))) {
1475 * get_password failed to get a password (for
1476 * example because one was supplied on the command
1477 * line which has already failed to work).
1480 logevent("No more passwords to try");
1481 ssh_state
= SSH_STATE_CLOSED
;
1485 c_write(prompt
, strlen(prompt
));
1489 crWaitUntil(!ispkt
);
1490 while (inlen
--) switch (c
= *in
++) {
1507 if (((c
>= ' ' && c
<= '~') ||
1508 ((unsigned char)c
>= 160)) && pos
< sizeof(password
))
1509 password
[pos
++] = c
;
1517 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
1519 * Try public key authentication with the specified
1522 static struct RSAKey pubkey
;
1523 static Bignum challenge
, response
;
1525 static unsigned char buffer
[32];
1527 tried_publickey
= 1;
1528 i
= loadrsakey(cfg
.keyfile
, &pubkey
, NULL
, password
);
1530 c_write("Couldn't load public key from ", 30);
1531 c_write(cfg
.keyfile
, strlen(cfg
.keyfile
));
1532 c_write(".\r\n", 3);
1533 continue; /* go and try password */
1536 c_write("Wrong passphrase.\r\n", 19);
1537 tried_publickey
= 0;
1538 continue; /* try again */
1542 * Send a public key attempt.
1544 send_packet(SSH1_CMSG_AUTH_RSA
,
1545 PKT_BIGNUM
, pubkey
.modulus
, PKT_END
);
1548 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1549 c_write("Server refused our public key.\r\n", 32);
1550 continue; /* go and try password */
1552 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
1553 bombout(("Bizarre response to offer of public key"));
1556 ssh1_read_bignum(pktin
.body
, &challenge
);
1557 response
= rsadecrypt(challenge
, &pubkey
);
1558 freebn(pubkey
.private_exponent
); /* burn the evidence */
1560 for (i
= 0; i
< 32; i
+= 2) {
1561 buffer
[i
] = response
[16-i
/2] >> 8;
1562 buffer
[i
+1] = response
[16-i
/2] & 0xFF;
1566 MD5Update(&md5c
, buffer
, 32);
1567 MD5Update(&md5c
, session_id
, 16);
1568 MD5Final(buffer
, &md5c
);
1570 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
1571 PKT_DATA
, buffer
, 16, PKT_END
);
1574 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1575 if (flags
& FLAG_VERBOSE
)
1576 c_write("Failed to authenticate with our public key.\r\n",
1578 continue; /* go and try password */
1579 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1580 bombout(("Bizarre response to RSA authentication response"));
1584 break; /* we're through! */
1586 send_packet(pwpkt_type
, PKT_STR
, password
, PKT_END
);
1588 logevent("Sent password");
1589 memset(password
, 0, strlen(password
));
1591 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1592 if (flags
& FLAG_VERBOSE
)
1593 c_write("Access denied\r\n", 15);
1594 logevent("Authentication refused");
1595 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
1596 logevent("Received disconnect request");
1597 ssh_state
= SSH_STATE_CLOSED
;
1599 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1600 bombout(("Strange packet received, type %d", pktin
.type
));
1605 logevent("Authentication successful");
1610 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
) {
1615 while (!do_ssh1_login(in
, inlen
, ispkt
)) {
1618 if (ssh_state
== SSH_STATE_CLOSED
)
1621 if (cfg
.agentfwd
&& agent_exists()) {
1622 logevent("Requesting agent forwarding");
1623 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
1624 do { crReturnV
; } while (!ispkt
);
1625 if (pktin
.type
!= SSH1_SMSG_SUCCESS
&& pktin
.type
!= SSH1_SMSG_FAILURE
) {
1626 bombout(("Protocol confusion"));
1628 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1629 logevent("Agent forwarding refused");
1631 logevent("Agent forwarding enabled");
1635 send_packet(SSH1_CMSG_REQUEST_PTY
,
1636 PKT_STR
, cfg
.termtype
,
1637 PKT_INT
, rows
, PKT_INT
, cols
,
1638 PKT_INT
, 0, PKT_INT
, 0,
1641 ssh_state
= SSH_STATE_INTERMED
;
1642 do { crReturnV
; } while (!ispkt
);
1643 if (pktin
.type
!= SSH1_SMSG_SUCCESS
&& pktin
.type
!= SSH1_SMSG_FAILURE
) {
1644 bombout(("Protocol confusion"));
1646 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1647 c_write("Server refused to allocate pty\r\n", 32);
1649 logevent("Allocated pty");
1652 if (*cfg
.remote_cmd
)
1653 send_packet(SSH1_CMSG_EXEC_CMD
, PKT_STR
, cfg
.remote_cmd
, PKT_END
);
1655 send_packet(SSH1_CMSG_EXEC_SHELL
, PKT_END
);
1656 logevent("Started session");
1658 ssh_state
= SSH_STATE_SESSION
;
1663 ssh_channels
= newtree234(ssh_channelcmp
);
1668 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
1669 pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
1670 long len
= GET_32BIT(pktin
.body
);
1671 from_backend(pktin
.type
== SSH1_SMSG_STDERR_DATA
,
1673 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
1674 ssh_state
= SSH_STATE_CLOSED
;
1675 logevent("Received disconnect request");
1676 } else if (pktin
.type
== SSH1_SMSG_AGENT_OPEN
) {
1677 /* Remote side is trying to open a channel to talk to our
1678 * agent. Give them back a local channel number. */
1680 struct ssh_channel
*c
;
1682 for (c
= first234(ssh_channels
, &e
); c
; c
= next234(&e
)) {
1684 break; /* found a free number */
1687 c
= malloc(sizeof(struct ssh_channel
));
1688 c
->remoteid
= GET_32BIT(pktin
.body
);
1691 c
->type
= SSH1_SMSG_AGENT_OPEN
; /* identify channel type */
1692 c
->u
.a
.lensofar
= 0;
1693 add234(ssh_channels
, c
);
1694 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
1695 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
1697 } else if (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE
||
1698 pktin
.type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
) {
1699 /* Remote side closes a channel. */
1700 unsigned i
= GET_32BIT(pktin
.body
);
1701 struct ssh_channel
*c
;
1702 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
1705 closetype
= (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
1 : 2);
1706 send_packet(pktin
.type
, PKT_INT
, c
->remoteid
, PKT_END
);
1707 c
->closes
|= closetype
;
1708 if (c
->closes
== 3) {
1709 del234(ssh_channels
, c
);
1713 } else if (pktin
.type
== SSH1_MSG_CHANNEL_DATA
) {
1714 /* Data sent down one of our channels. */
1715 int i
= GET_32BIT(pktin
.body
);
1716 int len
= GET_32BIT(pktin
.body
+4);
1717 unsigned char *p
= pktin
.body
+8;
1718 struct ssh_channel
*c
;
1719 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
1722 case SSH1_SMSG_AGENT_OPEN
:
1723 /* Data for an agent message. Buffer it. */
1725 if (c
->u
.a
.lensofar
< 4) {
1726 int l
= min(4 - c
->u
.a
.lensofar
, len
);
1727 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
, l
);
1728 p
+= l
; len
-= l
; c
->u
.a
.lensofar
+= l
;
1730 if (c
->u
.a
.lensofar
== 4) {
1731 c
->u
.a
.totallen
= 4 + GET_32BIT(c
->u
.a
.msglen
);
1732 c
->u
.a
.message
= malloc(c
->u
.a
.totallen
);
1733 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
1735 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
1736 int l
= min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
, len
);
1737 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
, l
);
1738 p
+= l
; len
-= l
; c
->u
.a
.lensofar
+= l
;
1740 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
1741 void *reply
, *sentreply
;
1743 agent_query(c
->u
.a
.message
, c
->u
.a
.totallen
,
1748 /* Fake SSH_AGENT_FAILURE. */
1749 sentreply
= "\0\0\0\1\5";
1752 send_packet(SSH1_MSG_CHANNEL_DATA
,
1753 PKT_INT
, c
->remoteid
,
1755 PKT_DATA
, sentreply
, replylen
,
1759 free(c
->u
.a
.message
);
1760 c
->u
.a
.lensofar
= 0;
1766 } else if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
1767 /* may be from EXEC_SHELL on some servers */
1768 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1769 /* may be from EXEC_SHELL on some servers
1770 * if no pty is available or in other odd cases. Ignore */
1771 } else if (pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
1772 send_packet(SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
1774 bombout(("Strange packet received: type %d", pktin
.type
));
1778 send_packet(SSH1_CMSG_STDIN_DATA
,
1779 PKT_INT
, inlen
, PKT_DATA
, in
, inlen
, PKT_END
);
1787 * Utility routine for decoding comma-separated strings in KEXINIT.
1789 static int in_commasep_string(char *needle
, char *haystack
, int haylen
) {
1790 int needlen
= strlen(needle
);
1793 * Is it at the start of the string?
1795 if (haylen
>= needlen
&& /* haystack is long enough */
1796 !memcmp(needle
, haystack
, needlen
) && /* initial match */
1797 (haylen
== needlen
|| haystack
[needlen
] == ',')
1798 /* either , or EOS follows */
1802 * If not, search for the next comma and resume after that.
1803 * If no comma found, terminate.
1805 while (haylen
> 0 && *haystack
!= ',')
1806 haylen
--, haystack
++;
1809 haylen
--, haystack
++; /* skip over comma itself */
1814 * SSH2 key creation method.
1816 static void ssh2_mkkey(Bignum K
, char *H
, char chr
, char *keyspace
) {
1818 /* First 20 bytes. */
1821 SHA_Bytes(&s
, H
, 20);
1822 SHA_Bytes(&s
, &chr
, 1);
1823 SHA_Bytes(&s
, H
, 20);
1824 SHA_Final(&s
, keyspace
);
1825 /* Next 20 bytes. */
1828 SHA_Bytes(&s
, H
, 20);
1829 SHA_Bytes(&s
, keyspace
, 20);
1830 SHA_Final(&s
, keyspace
+20);
1834 * Handle the SSH2 transport layer.
1836 static int do_ssh2_transport(unsigned char *in
, int inlen
, int ispkt
)
1840 static Bignum e
, f
, K
;
1841 static const struct ssh_mac
**maclist
;
1843 static const struct ssh_cipher
*cscipher_tobe
= NULL
;
1844 static const struct ssh_cipher
*sccipher_tobe
= NULL
;
1845 static const struct ssh_mac
*csmac_tobe
= NULL
;
1846 static const struct ssh_mac
*scmac_tobe
= NULL
;
1847 static const struct ssh_compress
*cscomp_tobe
= NULL
;
1848 static const struct ssh_compress
*sccomp_tobe
= NULL
;
1849 static char *hostkeydata
, *sigdata
, *keystr
, *fingerprint
;
1850 static int hostkeylen
, siglen
;
1851 static unsigned char exchange_hash
[20];
1852 static unsigned char keyspace
[40];
1853 static const struct ssh_cipher
*preferred_cipher
;
1859 * Set up the preferred cipher.
1861 if (cfg
.cipher
== CIPHER_BLOWFISH
) {
1862 preferred_cipher
= &ssh_blowfish_ssh2
;
1863 } else if (cfg
.cipher
== CIPHER_DES
) {
1864 logevent("Single DES not supported in SSH2; using 3DES");
1865 preferred_cipher
= &ssh_3des_ssh2
;
1866 } else if (cfg
.cipher
== CIPHER_3DES
) {
1867 preferred_cipher
= &ssh_3des_ssh2
;
1869 /* Shouldn't happen, but we do want to initialise to _something_. */
1870 preferred_cipher
= &ssh_3des_ssh2
;
1874 * Be prepared to work around the buggy MAC problem.
1877 maclist
= buggymacs
, nmacs
= lenof(buggymacs
);
1879 maclist
= macs
, nmacs
= lenof(macs
);
1883 * Construct and send our key exchange packet.
1885 ssh2_pkt_init(SSH2_MSG_KEXINIT
);
1886 for (i
= 0; i
< 16; i
++)
1887 ssh2_pkt_addbyte((unsigned char)random_byte());
1888 /* List key exchange algorithms. */
1889 ssh2_pkt_addstring_start();
1890 for (i
= 0; i
< lenof(kex_algs
); i
++) {
1891 ssh2_pkt_addstring_str(kex_algs
[i
]->name
);
1892 if (i
< lenof(kex_algs
)-1)
1893 ssh2_pkt_addstring_str(",");
1895 /* List server host key algorithms. */
1896 ssh2_pkt_addstring_start();
1897 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
1898 ssh2_pkt_addstring_str(hostkey_algs
[i
]->name
);
1899 if (i
< lenof(hostkey_algs
)-1)
1900 ssh2_pkt_addstring_str(",");
1902 /* List client->server encryption algorithms. */
1903 ssh2_pkt_addstring_start();
1904 for (i
= 0; i
< lenof(ciphers
)+1; i
++) {
1905 const struct ssh_cipher
*c
= i
==0 ? preferred_cipher
: ciphers
[i
-1];
1906 ssh2_pkt_addstring_str(c
->name
);
1907 if (i
< lenof(ciphers
))
1908 ssh2_pkt_addstring_str(",");
1910 /* List server->client encryption algorithms. */
1911 ssh2_pkt_addstring_start();
1912 for (i
= 0; i
< lenof(ciphers
)+1; i
++) {
1913 const struct ssh_cipher
*c
= i
==0 ? preferred_cipher
: ciphers
[i
-1];
1914 ssh2_pkt_addstring_str(c
->name
);
1915 if (i
< lenof(ciphers
))
1916 ssh2_pkt_addstring_str(",");
1918 /* List client->server MAC algorithms. */
1919 ssh2_pkt_addstring_start();
1920 for (i
= 0; i
< nmacs
; i
++) {
1921 ssh2_pkt_addstring_str(maclist
[i
]->name
);
1923 ssh2_pkt_addstring_str(",");
1925 /* List server->client MAC algorithms. */
1926 ssh2_pkt_addstring_start();
1927 for (i
= 0; i
< nmacs
; i
++) {
1928 ssh2_pkt_addstring_str(maclist
[i
]->name
);
1930 ssh2_pkt_addstring_str(",");
1932 /* List client->server compression algorithms. */
1933 ssh2_pkt_addstring_start();
1934 for (i
= 0; i
< lenof(compressions
); i
++) {
1935 ssh2_pkt_addstring_str(compressions
[i
]->name
);
1936 if (i
< lenof(compressions
)-1)
1937 ssh2_pkt_addstring_str(",");
1939 /* List server->client compression algorithms. */
1940 ssh2_pkt_addstring_start();
1941 for (i
= 0; i
< lenof(compressions
); i
++) {
1942 ssh2_pkt_addstring_str(compressions
[i
]->name
);
1943 if (i
< lenof(compressions
)-1)
1944 ssh2_pkt_addstring_str(",");
1946 /* List client->server languages. Empty list. */
1947 ssh2_pkt_addstring_start();
1948 /* List server->client languages. Empty list. */
1949 ssh2_pkt_addstring_start();
1950 /* First KEX packet does _not_ follow, because we're not that brave. */
1951 ssh2_pkt_addbool(FALSE
);
1953 ssh2_pkt_adduint32(0);
1954 sha_string(&exhash
, pktout
.data
+5, pktout
.length
-5);
1957 if (!ispkt
) crWaitUntil(ispkt
);
1958 sha_string(&exhash
, pktin
.data
+5, pktin
.length
-5);
1961 * Now examine the other side's KEXINIT to see what we're up
1964 if (pktin
.type
!= SSH2_MSG_KEXINIT
) {
1965 bombout(("expected key exchange packet from server"));
1968 kex
= NULL
; hostkey
= NULL
; cscipher_tobe
= NULL
; sccipher_tobe
= NULL
;
1969 csmac_tobe
= NULL
; scmac_tobe
= NULL
; cscomp_tobe
= NULL
; sccomp_tobe
= NULL
;
1970 pktin
.savedpos
+= 16; /* skip garbage cookie */
1971 ssh2_pkt_getstring(&str
, &len
); /* key exchange algorithms */
1972 for (i
= 0; i
< lenof(kex_algs
); i
++) {
1973 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
1978 ssh2_pkt_getstring(&str
, &len
); /* host key algorithms */
1979 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
1980 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
1981 hostkey
= hostkey_algs
[i
];
1985 ssh2_pkt_getstring(&str
, &len
); /* client->server cipher */
1986 for (i
= 0; i
< lenof(ciphers
)+1; i
++) {
1987 const struct ssh_cipher
*c
= i
==0 ? preferred_cipher
: ciphers
[i
-1];
1988 if (in_commasep_string(c
->name
, str
, len
)) {
1993 ssh2_pkt_getstring(&str
, &len
); /* server->client cipher */
1994 for (i
= 0; i
< lenof(ciphers
)+1; i
++) {
1995 const struct ssh_cipher
*c
= i
==0 ? preferred_cipher
: ciphers
[i
-1];
1996 if (in_commasep_string(c
->name
, str
, len
)) {
2001 ssh2_pkt_getstring(&str
, &len
); /* client->server mac */
2002 for (i
= 0; i
< nmacs
; i
++) {
2003 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
2004 csmac_tobe
= maclist
[i
];
2008 ssh2_pkt_getstring(&str
, &len
); /* server->client mac */
2009 for (i
= 0; i
< nmacs
; i
++) {
2010 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
2011 scmac_tobe
= maclist
[i
];
2015 ssh2_pkt_getstring(&str
, &len
); /* client->server compression */
2016 for (i
= 0; i
< lenof(compressions
); i
++) {
2017 if (in_commasep_string(compressions
[i
]->name
, str
, len
)) {
2018 cscomp_tobe
= compressions
[i
];
2022 ssh2_pkt_getstring(&str
, &len
); /* server->client compression */
2023 for (i
= 0; i
< lenof(compressions
); i
++) {
2024 if (in_commasep_string(compressions
[i
]->name
, str
, len
)) {
2025 sccomp_tobe
= compressions
[i
];
2031 * Currently we only support Diffie-Hellman and DSS, so let's
2032 * bomb out if those aren't selected.
2034 if (kex
!= &ssh_diffiehellman
|| hostkey
!= &ssh_dss
) {
2035 bombout(("internal fault: chaos in SSH 2 transport layer"));
2040 * Now we begin the fun. Generate and send e for Diffie-Hellman.
2043 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT
);
2048 if (pktin
.type
!= SSH2_MSG_KEXDH_REPLY
) {
2049 bombout(("expected key exchange packet from server"));
2052 ssh2_pkt_getstring(&hostkeydata
, &hostkeylen
);
2053 f
= ssh2_pkt_getmp();
2054 ssh2_pkt_getstring(&sigdata
, &siglen
);
2058 sha_string(&exhash
, hostkeydata
, hostkeylen
);
2059 sha_mpint(&exhash
, e
);
2060 sha_mpint(&exhash
, f
);
2061 sha_mpint(&exhash
, K
);
2062 SHA_Final(&exhash
, exchange_hash
);
2065 debug(("Exchange hash is:\r\n"));
2066 for (i
= 0; i
< 20; i
++)
2067 debug((" %02x", exchange_hash
[i
]));
2071 hostkey
->setkey(hostkeydata
, hostkeylen
);
2072 if (!hostkey
->verifysig(sigdata
, siglen
, exchange_hash
, 20)) {
2073 bombout(("Server failed host key check"));
2078 * Expect SSH2_MSG_NEWKEYS from server.
2081 if (pktin
.type
!= SSH2_MSG_NEWKEYS
) {
2082 bombout(("expected new-keys packet from server"));
2087 * Authenticate remote host: verify host key. (We've already
2088 * checked the signature of the exchange hash.)
2090 keystr
= hostkey
->fmtkey();
2091 fingerprint
= hostkey
->fingerprint();
2092 verify_ssh_host_key(savedhost
, savedport
, hostkey
->keytype
,
2093 keystr
, fingerprint
);
2094 logevent("Host key fingerprint is:");
2095 logevent(fingerprint
);
2100 * Send SSH2_MSG_NEWKEYS.
2102 ssh2_pkt_init(SSH2_MSG_NEWKEYS
);
2106 * Create and initialise session keys.
2108 cscipher
= cscipher_tobe
;
2109 sccipher
= sccipher_tobe
;
2112 cscomp
= cscomp_tobe
;
2113 sccomp
= sccomp_tobe
;
2115 * Set IVs after keys.
2117 ssh2_mkkey(K
, exchange_hash
, 'C', keyspace
); cscipher
->setcskey(keyspace
);
2118 ssh2_mkkey(K
, exchange_hash
, 'D', keyspace
); cscipher
->setsckey(keyspace
);
2119 ssh2_mkkey(K
, exchange_hash
, 'A', keyspace
); cscipher
->setcsiv(keyspace
);
2120 ssh2_mkkey(K
, exchange_hash
, 'B', keyspace
); sccipher
->setsciv(keyspace
);
2121 ssh2_mkkey(K
, exchange_hash
, 'E', keyspace
); csmac
->setcskey(keyspace
);
2122 ssh2_mkkey(K
, exchange_hash
, 'F', keyspace
); scmac
->setsckey(keyspace
);
2125 * Now we're encrypting. Begin returning 1 to the protocol main
2126 * function so that other things can run on top of the
2127 * transport. If we ever see a KEXINIT, we must go back to the
2132 } while (!(ispkt
&& pktin
.type
== SSH2_MSG_KEXINIT
));
2133 goto begin_key_exchange
;
2139 * Handle the SSH2 userauth and connection layers.
2141 static void do_ssh2_authconn(unsigned char *in
, int inlen
, int ispkt
)
2143 static unsigned long remote_winsize
;
2144 static unsigned long remote_maxpkt
;
2149 * Request userauth protocol, and await a response to it.
2151 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
2152 ssh2_pkt_addstring("ssh-userauth");
2154 crWaitUntilV(ispkt
);
2155 if (pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
) {
2156 bombout(("Server refused user authentication protocol"));
2161 * FIXME: currently we support only password authentication.
2162 * (This places us technically in violation of the SSH2 spec.
2163 * We must fix this.)
2167 * Get a username and a password.
2169 static char username
[100];
2170 static char password
[100];
2174 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
2175 c_write("login as: ", 10);
2178 crWaitUntilV(!ispkt
);
2179 while (inlen
--) switch (c
= *in
++) {
2186 c_write("\b \b", 3);
2192 c_write("\b \b", 3);
2201 if (((c
>= ' ' && c
<= '~') ||
2202 ((unsigned char)c
>= 160)) && pos
< 40) {
2203 username
[pos
++] = c
;
2210 username
[strcspn(username
, "\n\r")] = '\0';
2213 strncpy(username
, cfg
.username
, 99);
2214 username
[99] = '\0';
2215 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
2216 sprintf(stuff
, "Using username \"%s\".\r\n", username
);
2217 c_write(stuff
, strlen(stuff
));
2221 if (ssh_get_password
) {
2223 sprintf(prompt
, "%.90s@%.90s's password: ", username
, savedhost
);
2224 if (!ssh_get_password(prompt
, password
, sizeof(password
))) {
2226 * get_password failed to get a password (for
2227 * example because one was supplied on the command
2228 * line which has already failed to work).
2231 logevent("No more passwords to try");
2232 ssh_state
= SSH_STATE_CLOSED
;
2236 c_write("password: ", 10);
2241 crWaitUntilV(!ispkt
);
2242 while (inlen
--) switch (c
= *in
++) {
2259 if (((c
>= ' ' && c
<= '~') ||
2260 ((unsigned char)c
>= 160)) && pos
< 40)
2261 password
[pos
++] = c
;
2268 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
2269 ssh2_pkt_addstring(username
);
2270 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2271 ssh2_pkt_addstring("password");
2272 ssh2_pkt_addbool(FALSE
);
2273 ssh2_pkt_addstring(password
);
2276 crWaitUntilV(ispkt
);
2277 if (pktin
.type
!= SSH2_MSG_USERAUTH_SUCCESS
) {
2278 c_write("Access denied\r\n", 15);
2279 logevent("Authentication refused");
2285 * Now we're authenticated for the connection protocol. The
2286 * connection protocol will automatically have started at this
2287 * point; there's no need to send SERVICE_REQUEST.
2291 * So now create a channel with a session in it.
2293 mainchan
= malloc(sizeof(struct ssh_channel
));
2294 mainchan
->localid
= 100; /* as good as any */
2295 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
2296 ssh2_pkt_addstring("session");
2297 ssh2_pkt_adduint32(mainchan
->localid
);
2298 ssh2_pkt_adduint32(0x8000UL
); /* our window size */
2299 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
2301 crWaitUntilV(ispkt
);
2302 if (pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
2303 bombout(("Server refused to open a session"));
2305 /* FIXME: error data comes back in FAILURE packet */
2307 if (ssh2_pkt_getuint32() != mainchan
->localid
) {
2308 bombout(("Server's channel confirmation cited wrong channel"));
2311 mainchan
->remoteid
= ssh2_pkt_getuint32();
2312 mainchan
->u
.v2
.remwindow
= ssh2_pkt_getuint32();
2313 mainchan
->u
.v2
.remmaxpkt
= ssh2_pkt_getuint32();
2314 mainchan
->u
.v2
.outbuffer
= NULL
;
2315 mainchan
->u
.v2
.outbuflen
= mainchan
->u
.v2
.outbufsize
= 0;
2316 logevent("Opened channel for session");
2319 * Now allocate a pty for the session.
2322 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
2323 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
2324 ssh2_pkt_addstring("pty-req");
2325 ssh2_pkt_addbool(1); /* want reply */
2326 ssh2_pkt_addstring(cfg
.termtype
);
2327 ssh2_pkt_adduint32(cols
);
2328 ssh2_pkt_adduint32(rows
);
2329 ssh2_pkt_adduint32(0); /* pixel width */
2330 ssh2_pkt_adduint32(0); /* pixel height */
2331 ssh2_pkt_addstring_start();
2332 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
2336 crWaitUntilV(ispkt
);
2337 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
2338 /* FIXME: be able to handle other channels here */
2339 if (ssh2_pkt_getuint32() != mainchan
->localid
)
2340 continue; /* wrong channel */
2341 mainchan
->u
.v2
.remwindow
+= ssh2_pkt_getuint32();
2343 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
2345 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
2346 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
2347 bombout(("Server got confused by pty request"));
2350 c_write("Server refused to allocate pty\r\n", 32);
2352 logevent("Allocated pty");
2357 * Start a shell or a remote command.
2359 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
2360 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
2361 if (*cfg
.remote_cmd
) {
2362 ssh2_pkt_addstring("exec");
2363 ssh2_pkt_addbool(1); /* want reply */
2364 ssh2_pkt_addstring(cfg
.remote_cmd
);
2366 ssh2_pkt_addstring("shell");
2367 ssh2_pkt_addbool(1); /* want reply */
2371 crWaitUntilV(ispkt
);
2372 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
2373 /* FIXME: be able to handle other channels here */
2374 if (ssh2_pkt_getuint32() != mainchan
->localid
)
2375 continue; /* wrong channel */
2376 mainchan
->u
.v2
.remwindow
+= ssh2_pkt_getuint32();
2378 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
2379 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
2380 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
2381 bombout(("Server got confused by shell/command request"));
2384 bombout(("Server refused to start a shell/command"));
2387 logevent("Started a shell/command");
2396 static int try_send
;
2400 if (pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
2401 pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
2404 /* FIXME: be able to handle other channels here */
2405 if (ssh2_pkt_getuint32() != mainchan
->localid
)
2406 continue; /* wrong channel */
2407 if (pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
2408 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR
)
2409 continue; /* extended but not stderr */
2410 ssh2_pkt_getstring(&data
, &length
);
2412 from_backend(pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
,
2415 * Enlarge the window again at the remote side,
2416 * just in case it ever runs down and they fail
2417 * to send us any more data.
2419 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
2420 ssh2_pkt_adduint32(mainchan
->remoteid
);
2421 ssh2_pkt_adduint32(length
);
2424 } else if (pktin
.type
== SSH2_MSG_DISCONNECT
) {
2425 ssh_state
= SSH_STATE_CLOSED
;
2426 logevent("Received disconnect message");
2427 } else if (pktin
.type
== SSH2_MSG_CHANNEL_REQUEST
) {
2428 continue; /* exit status et al; ignore (FIXME?) */
2429 } else if (pktin
.type
== SSH2_MSG_CHANNEL_EOF
) {
2430 continue; /* remote sends EOF; ignore */
2431 } else if (pktin
.type
== SSH2_MSG_CHANNEL_CLOSE
) {
2432 /* FIXME: be able to handle other channels here */
2433 if (ssh2_pkt_getuint32() != mainchan
->localid
)
2434 continue; /* wrong channel */
2435 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
2436 ssh2_pkt_adduint32(mainchan
->remoteid
);
2438 /* FIXME: mark the channel as closed */
2439 if (1 /* FIXME: "all channels are closed" */) {
2440 logevent("All channels closed. Disconnecting");
2441 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
2443 ssh_state
= SSH_STATE_CLOSED
;
2447 continue; /* remote sends close; ignore (FIXME) */
2448 } else if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
2449 /* FIXME: be able to handle other channels here */
2450 if (ssh2_pkt_getuint32() != mainchan
->localid
)
2451 continue; /* wrong channel */
2452 mainchan
->u
.v2
.remwindow
+= ssh2_pkt_getuint32();
2455 bombout(("Strange packet received: type %d", pktin
.type
));
2460 * We have spare data. Add it to the channel buffer.
2462 if (mainchan
->u
.v2
.outbufsize
<
2463 mainchan
->u
.v2
.outbuflen
+ inlen
) {
2464 mainchan
->u
.v2
.outbufsize
=
2465 mainchan
->u
.v2
.outbuflen
+ inlen
+ 1024;
2466 mainchan
->u
.v2
.outbuffer
= srealloc(mainchan
->u
.v2
.outbuffer
,
2467 mainchan
->u
.v2
.outbufsize
);
2469 memcpy(mainchan
->u
.v2
.outbuffer
+ mainchan
->u
.v2
.outbuflen
,
2471 mainchan
->u
.v2
.outbuflen
+= inlen
;
2476 * Try to send data on the channel if we can. (FIXME:
2477 * on _all_ channels.)
2479 while (mainchan
->u
.v2
.remwindow
> 0 &&
2480 mainchan
->u
.v2
.outbuflen
> 0) {
2481 unsigned len
= mainchan
->u
.v2
.remwindow
;
2482 if (len
> mainchan
->u
.v2
.outbuflen
)
2483 len
= mainchan
->u
.v2
.outbuflen
;
2484 if (len
> mainchan
->u
.v2
.remmaxpkt
)
2485 len
= mainchan
->u
.v2
.remmaxpkt
;
2486 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA
);
2487 ssh2_pkt_adduint32(mainchan
->remoteid
);
2488 ssh2_pkt_addstring_start();
2489 ssh2_pkt_addstring_data(mainchan
->u
.v2
.outbuffer
, len
);
2491 mainchan
->u
.v2
.outbuflen
-= len
;
2492 memmove(mainchan
->u
.v2
.outbuffer
, mainchan
->u
.v2
.outbuffer
+len
,
2493 mainchan
->u
.v2
.outbuflen
);
2494 mainchan
->u
.v2
.remwindow
-= len
;
2503 * Handle the top-level SSH2 protocol.
2505 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
)
2507 if (do_ssh2_transport(in
, inlen
, ispkt
) == 0)
2509 do_ssh2_authconn(in
, inlen
, ispkt
);
2513 * Called to set up the connection. Will arrange for WM_NETEVENT
2514 * messages to be passed to the specified window, whose window
2515 * procedure should then call telnet_msg().
2517 * Returns an error message, or NULL on success.
2519 static char *ssh_init (HWND hwnd
, char *host
, int port
, char **realhost
) {
2523 if(crypto_startup() == 0)
2524 return "Microsoft high encryption pack not installed!";
2527 p
= connect_to_host(host
, port
, realhost
);
2532 return "Protocol initialisation error";
2534 if (hwnd
&& WSAAsyncSelect (s
, hwnd
, WM_NETEVENT
, FD_READ
| FD_CLOSE
) == SOCKET_ERROR
)
2535 switch (WSAGetLastError()) {
2536 case WSAENETDOWN
: return "Network is down";
2537 default: return "WSAAsyncSelect(): unknown error";
2544 * Process a WM_NETEVENT message. Will return 0 if the connection
2545 * has closed, or <0 for a socket error.
2547 static int ssh_msg (WPARAM wParam
, LPARAM lParam
) {
2552 * Because reading less than the whole of the available pending
2553 * data can generate an FD_READ event, we need to allow for the
2554 * possibility that FD_READ may arrive with FD_CLOSE already in
2555 * the queue; so it's possible that we can get here even with s
2556 * invalid. If so, we return 1 and don't worry about it.
2558 if (s
== INVALID_SOCKET
)
2561 if (WSAGETSELECTERROR(lParam
) != 0) {
2564 return -WSAGETSELECTERROR(lParam
);
2567 switch (WSAGETSELECTEVENT(lParam
)) {
2570 ret
= recv(s
, buf
, sizeof(buf
), 0);
2571 if (ret
< 0 && WSAGetLastError() == WSAEWOULDBLOCK
)
2573 if (ret
< 0) { /* any _other_ error */
2576 return -10000-WSAGetLastError();
2582 ssh_gotdata (buf
, ret
);
2583 if (ssh_state
== SSH_STATE_CLOSED
) {
2590 return 1; /* shouldn't happen, but WTF */
2594 * Called to send data down the Telnet connection.
2596 static void ssh_send (char *buf
, int len
) {
2597 if (s
== INVALID_SOCKET
)
2600 ssh_protocol(buf
, len
, 0);
2604 * Called to set the size of the window from Telnet's POV.
2606 static void ssh_size(void) {
2607 switch (ssh_state
) {
2608 case SSH_STATE_BEFORE_SIZE
:
2609 case SSH_STATE_CLOSED
:
2610 break; /* do nothing */
2611 case SSH_STATE_INTERMED
:
2612 size_needed
= TRUE
; /* buffer for later */
2614 case SSH_STATE_SESSION
:
2616 send_packet(SSH1_CMSG_WINDOW_SIZE
,
2617 PKT_INT
, rows
, PKT_INT
, cols
,
2618 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
2624 * Send Telnet special codes. TS_EOF is useful for `plink', so you
2625 * can send an EOF and collect resulting output (e.g. `plink
2628 static void ssh_special (Telnet_Special code
) {
2629 if (code
== TS_EOF
) {
2630 if (ssh_version
== 1) {
2631 send_packet(SSH1_CMSG_EOF
, PKT_END
);
2633 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF
);
2634 ssh2_pkt_adduint32(mainchan
->remoteid
);
2637 logevent("Sent EOF message");
2638 } else if (code
== TS_PING
) {
2639 if (ssh_version
== 1) {
2640 send_packet(SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
2642 ssh2_pkt_init(SSH2_MSG_IGNORE
);
2643 ssh2_pkt_addstring_start();
2651 static SOCKET
ssh_socket(void) { return s
; }
2653 static int ssh_sendok(void) { return ssh_send_ok
; }
2655 Backend ssh_backend
= {