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_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
105 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
106 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
107 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
108 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
109 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
110 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
111 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
112 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
113 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
114 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
116 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
117 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
118 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
119 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
121 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
123 #define GET_32BIT(cp) \
124 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
125 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
126 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
127 ((unsigned long)(unsigned char)(cp)[3]))
129 #define PUT_32BIT(cp, value) { \
130 (cp)[0] = (unsigned char)((value) >> 24); \
131 (cp)[1] = (unsigned char)((value) >> 16); \
132 (cp)[2] = (unsigned char)((value) >> 8); \
133 (cp)[3] = (unsigned char)(value); }
135 enum { PKT_END
, PKT_INT
, PKT_CHAR
, PKT_DATA
, PKT_STR
, PKT_BIGNUM
};
137 /* Coroutine mechanics for the sillier bits of the code */
138 #define crBegin1 static int crLine = 0;
139 #define crBegin2 switch(crLine) { case 0:;
140 #define crBegin crBegin1; crBegin2;
141 #define crFinish(z) } crLine = 0; return (z)
142 #define crFinishV } crLine = 0; return
143 #define crReturn(z) \
145 crLine=__LINE__; return (z); case __LINE__:;\
149 crLine=__LINE__; return; case __LINE__:;\
151 #define crStop(z) do{ crLine = 0; return (z); }while(0)
152 #define crStopV do{ crLine = 0; return; }while(0)
153 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
154 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
156 extern const struct ssh_cipher ssh_3des
;
157 extern const struct ssh_cipher ssh_3des_ssh2
;
158 extern const struct ssh_cipher ssh_des
;
159 extern const struct ssh_cipher ssh_blowfish_ssh1
;
160 extern const struct ssh_cipher ssh_blowfish_ssh2
;
163 * Ciphers for SSH2. We miss out single-DES because it isn't
164 * supported; also 3DES and Blowfish are both done differently from
165 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
166 * endianness and different-sized keys.)
168 const static struct ssh_cipher
*ciphers
[] = { &ssh_blowfish_ssh2
, &ssh_3des_ssh2
};
170 extern const struct ssh_kex ssh_diffiehellman
;
171 const static struct ssh_kex
*kex_algs
[] = { &ssh_diffiehellman
};
173 extern const struct ssh_hostkey ssh_dss
;
174 const static struct ssh_hostkey
*hostkey_algs
[] = { &ssh_dss
};
176 extern const struct ssh_mac ssh_md5
, ssh_sha1
, ssh_sha1_buggy
;
178 static void nullmac_key(unsigned char *key
) { }
179 static void nullmac_generate(unsigned char *blk
, int len
, unsigned long seq
) { }
180 static int nullmac_verify(unsigned char *blk
, int len
, unsigned long seq
) { return 1; }
181 const static struct ssh_mac ssh_mac_none
= {
182 nullmac_key
, nullmac_key
, nullmac_generate
, nullmac_verify
, "none", 0
184 const static struct ssh_mac
*macs
[] = {
185 &ssh_sha1
, &ssh_md5
, &ssh_mac_none
};
186 const static struct ssh_mac
*buggymacs
[] = {
187 &ssh_sha1_buggy
, &ssh_md5
, &ssh_mac_none
};
189 const static struct ssh_compress ssh_comp_none
= {
192 const static struct ssh_compress
*compressions
[] = { &ssh_comp_none
};
195 * 2-3-4 tree storing channels.
198 unsigned remoteid
, localid
;
202 struct ssh_agent_channel
{
203 unsigned char *message
;
204 unsigned char msglen
[4];
205 int lensofar
, totallen
;
207 struct ssh2_data_channel
{
208 unsigned char *outbuffer
;
209 unsigned outbuflen
, outbufsize
;
210 unsigned remwindow
, remmaxpkt
;
224 static SHA_State exhash
;
226 static Socket s
= NULL
;
228 static unsigned char session_key
[32];
229 static const struct ssh_cipher
*cipher
= NULL
;
230 static const struct ssh_cipher
*cscipher
= NULL
;
231 static const struct ssh_cipher
*sccipher
= NULL
;
232 static const struct ssh_mac
*csmac
= NULL
;
233 static const struct ssh_mac
*scmac
= NULL
;
234 static const struct ssh_compress
*cscomp
= NULL
;
235 static const struct ssh_compress
*sccomp
= NULL
;
236 static const struct ssh_kex
*kex
= NULL
;
237 static const struct ssh_hostkey
*hostkey
= NULL
;
238 int (*ssh_get_password
)(const char *prompt
, char *str
, int maxlen
) = NULL
;
240 static char *savedhost
;
241 static int savedport
;
242 static int ssh_send_ok
;
244 static tree234
*ssh_channels
; /* indexed by local id */
245 static struct ssh_channel
*mainchan
; /* primary session channel */
248 SSH_STATE_BEFORE_SIZE
,
252 } ssh_state
= SSH_STATE_BEFORE_SIZE
;
254 static int size_needed
= FALSE
;
256 static struct Packet pktin
= { 0, 0, NULL
, NULL
, 0 };
257 static struct Packet pktout
= { 0, 0, NULL
, NULL
, 0 };
259 static int ssh_version
;
260 static void (*ssh_protocol
)(unsigned char *in
, int inlen
, int ispkt
);
261 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
);
262 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
);
263 static void ssh_size(void);
265 static int (*s_rdpkt
)(unsigned char **data
, int *datalen
);
267 static struct rdpkt1_state_tag
{
268 long len
, pad
, biglen
, to_read
;
269 unsigned long realcrc
, gotcrc
;
275 static struct rdpkt2_state_tag
{
276 long len
, pad
, payload
, packetlen
, maclen
;
279 unsigned long incoming_sequence
;
282 static int ssh_channelcmp(void *av
, void *bv
) {
283 struct ssh_channel
*a
= (struct ssh_channel
*)av
;
284 struct ssh_channel
*b
= (struct ssh_channel
*)bv
;
285 if (a
->localid
< b
->localid
) return -1;
286 if (a
->localid
> b
->localid
) return +1;
289 static int ssh_channelfind(void *av
, void *bv
) {
290 unsigned *a
= (unsigned *)av
;
291 struct ssh_channel
*b
= (struct ssh_channel
*)bv
;
292 if (*a
< b
->localid
) return -1;
293 if (*a
> b
->localid
) return +1;
297 static void c_write (char *buf
, int len
) {
298 if ((flags
& FLAG_STDERR
)) {
300 for (i
= 0; i
< len
; i
++)
302 fputc(buf
[i
], stderr
);
305 from_backend(1, buf
, len
);
309 * Collect incoming data in the incoming packet buffer.
310 * Decipher and verify the packet when it is completely read.
311 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
312 * Update the *data and *datalen variables.
313 * Return the additional nr of bytes needed, or 0 when
314 * a complete packet is available.
316 static int ssh1_rdpkt(unsigned char **data
, int *datalen
)
318 struct rdpkt1_state_tag
*st
= &rdpkt1_state
;
327 for (st
->i
= st
->len
= 0; st
->i
< 4; st
->i
++) {
328 while ((*datalen
) == 0)
330 st
->len
= (st
->len
<< 8) + **data
;
331 (*data
)++, (*datalen
)--;
335 if (st
->len
== 0x52656d6f) { /* "Remo"te server has closed ... */
336 st
->len
= 0x300; /* big enough to carry to end */
340 st
->pad
= 8 - (st
->len
% 8);
341 st
->biglen
= st
->len
+ st
->pad
;
342 pktin
.length
= st
->len
- 5;
344 if (pktin
.maxlen
< st
->biglen
) {
345 pktin
.maxlen
= st
->biglen
;
346 pktin
.data
= (pktin
.data
== NULL ?
malloc(st
->biglen
+APIEXTRA
) :
347 realloc(pktin
.data
, st
->biglen
+APIEXTRA
));
349 fatalbox("Out of memory");
352 st
->to_read
= st
->biglen
;
354 while (st
->to_read
> 0) {
355 st
->chunk
= st
->to_read
;
356 while ((*datalen
) == 0)
357 crReturn(st
->to_read
);
358 if (st
->chunk
> (*datalen
))
359 st
->chunk
= (*datalen
);
360 memcpy(st
->p
, *data
, st
->chunk
);
362 *datalen
-= st
->chunk
;
364 st
->to_read
-= st
->chunk
;
368 cipher
->decrypt(pktin
.data
, st
->biglen
);
370 debug(("Got packet len=%d pad=%d\r\n", st
->len
, st
->pad
));
371 for (st
->i
= 0; st
->i
< st
->biglen
; st
->i
++)
372 debug((" %02x", (unsigned char)pktin
.data
[st
->i
]));
376 pktin
.type
= pktin
.data
[st
->pad
];
377 pktin
.body
= pktin
.data
+ st
->pad
+ 1;
379 st
->realcrc
= crc32(pktin
.data
, st
->biglen
-4);
380 st
->gotcrc
= GET_32BIT(pktin
.data
+st
->biglen
-4);
381 if (st
->gotcrc
!= st
->realcrc
) {
382 bombout(("Incorrect CRC received on packet"));
386 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
387 pktin
.type
== SSH1_SMSG_STDERR_DATA
||
388 pktin
.type
== SSH1_MSG_DEBUG
||
389 pktin
.type
== SSH1_SMSG_AUTH_TIS_CHALLENGE
||
390 pktin
.type
== SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
391 long strlen
= GET_32BIT(pktin
.body
);
392 if (strlen
+ 4 != pktin
.length
) {
393 bombout(("Received data packet with bogus string length"));
398 if (pktin
.type
== SSH1_MSG_DEBUG
) {
399 /* log debug message */
401 int strlen
= GET_32BIT(pktin
.body
);
402 strcpy(buf
, "Remote: ");
403 if (strlen
> 70) strlen
= 70;
404 memcpy(buf
+8, pktin
.body
+4, strlen
);
405 buf
[8+strlen
] = '\0';
408 } else if (pktin
.type
== SSH1_MSG_IGNORE
) {
416 static int ssh2_rdpkt(unsigned char **data
, int *datalen
)
418 struct rdpkt2_state_tag
*st
= &rdpkt2_state
;
426 st
->cipherblk
= sccipher
->blksize
;
429 if (st
->cipherblk
< 8)
432 if (pktin
.maxlen
< st
->cipherblk
) {
433 pktin
.maxlen
= st
->cipherblk
;
434 pktin
.data
= (pktin
.data
== NULL ?
malloc(st
->cipherblk
+APIEXTRA
) :
435 realloc(pktin
.data
, st
->cipherblk
+APIEXTRA
));
437 fatalbox("Out of memory");
441 * Acquire and decrypt the first block of the packet. This will
442 * contain the length and padding details.
444 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
445 while ((*datalen
) == 0)
446 crReturn(st
->cipherblk
-st
->i
);
447 pktin
.data
[st
->i
] = *(*data
)++;
451 if (!memcmp(pktin
.data
, "Remo", 4)) {/* "Remo"te server has closed ... */
456 sccipher
->decrypt(pktin
.data
, st
->cipherblk
);
459 * Now get the length and padding figures.
461 st
->len
= GET_32BIT(pktin
.data
);
462 st
->pad
= pktin
.data
[4];
465 * This enables us to deduce the payload length.
467 st
->payload
= st
->len
- st
->pad
- 1;
469 pktin
.length
= st
->payload
+ 5;
472 * So now we can work out the total packet length.
474 st
->packetlen
= st
->len
+ 4;
475 st
->maclen
= scmac ? scmac
->len
: 0;
478 * Adjust memory allocation if packet is too big.
480 if (pktin
.maxlen
< st
->packetlen
+st
->maclen
) {
481 pktin
.maxlen
= st
->packetlen
+st
->maclen
;
482 pktin
.data
= (pktin
.data
== NULL ?
malloc(pktin
.maxlen
+APIEXTRA
) :
483 realloc(pktin
.data
, pktin
.maxlen
+APIEXTRA
));
485 fatalbox("Out of memory");
489 * Read and decrypt the remainder of the packet.
491 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
; st
->i
++) {
492 while ((*datalen
) == 0)
493 crReturn(st
->packetlen
+ st
->maclen
- st
->i
);
494 pktin
.data
[st
->i
] = *(*data
)++;
497 /* Decrypt everything _except_ the MAC. */
499 sccipher
->decrypt(pktin
.data
+ st
->cipherblk
,
500 st
->packetlen
- st
->cipherblk
);
503 debug(("Got packet len=%d pad=%d\r\n", st
->len
, st
->pad
));
504 for (st
->i
= 0; st
->i
< st
->packetlen
; st
->i
++)
505 debug((" %02x", (unsigned char)pktin
.data
[st
->i
]));
512 if (scmac
&& !scmac
->verify(pktin
.data
, st
->len
+4, st
->incoming_sequence
)) {
513 bombout(("Incorrect MAC received on packet"));
516 st
->incoming_sequence
++; /* whether or not we MACed */
519 pktin
.type
= pktin
.data
[5];
521 if (pktin
.type
== SSH2_MSG_IGNORE
|| pktin
.type
== SSH2_MSG_DEBUG
)
522 goto next_packet
; /* FIXME: print DEBUG message */
527 static void s_wrpkt_start(int type
, int len
) {
530 len
+= 5; /* type and CRC */
534 pktout
.length
= len
-5;
535 if (pktout
.maxlen
< biglen
) {
536 pktout
.maxlen
= biglen
;
538 /* Allocate enough buffer space for extra block
539 * for MS CryptEncrypt() */
540 pktout
.data
= (pktout
.data
== NULL ?
malloc(biglen
+12) :
541 realloc(pktout
.data
, biglen
+12));
543 pktout
.data
= (pktout
.data
== NULL ?
malloc(biglen
+4) :
544 realloc(pktout
.data
, biglen
+4));
547 fatalbox("Out of memory");
551 pktout
.body
= pktout
.data
+4+pad
+1;
554 static void s_wrpkt(void) {
555 int pad
, len
, biglen
, i
;
558 len
= pktout
.length
+ 5; /* type and CRC */
562 pktout
.body
[-1] = pktout
.type
;
563 for (i
=0; i
<pad
; i
++)
564 pktout
.data
[i
+4] = random_byte();
565 crc
= crc32(pktout
.data
+4, biglen
-4);
566 PUT_32BIT(pktout
.data
+biglen
, crc
);
567 PUT_32BIT(pktout
.data
, len
);
570 debug(("Sending packet len=%d\r\n", biglen
+4));
571 for (i
= 0; i
< biglen
+4; i
++)
572 debug((" %02x", (unsigned char)pktout
.data
[i
]));
576 cipher
->encrypt(pktout
.data
+4, biglen
);
578 sk_write(s
, pktout
.data
, biglen
+4);
582 * Construct a packet with the specified contents and
583 * send it to the server.
585 static void send_packet(int pkttype
, ...)
588 unsigned char *p
, *argp
, argchar
;
589 unsigned long argint
;
590 int pktlen
, argtype
, arglen
;
594 va_start(args
, pkttype
);
595 while ((argtype
= va_arg(args
, int)) != PKT_END
) {
598 (void) va_arg(args
, int);
602 (void) va_arg(args
, char);
606 (void) va_arg(args
, unsigned char *);
607 arglen
= va_arg(args
, int);
611 argp
= va_arg(args
, unsigned char *);
612 arglen
= strlen(argp
);
613 pktlen
+= 4 + arglen
;
616 bn
= va_arg(args
, Bignum
);
617 pktlen
+= ssh1_bignum_length(bn
);
625 s_wrpkt_start(pkttype
, pktlen
);
628 va_start(args
, pkttype
);
629 while ((argtype
= va_arg(args
, int)) != PKT_END
) {
632 argint
= va_arg(args
, int);
633 PUT_32BIT(p
, argint
);
637 argchar
= va_arg(args
, unsigned char);
642 argp
= va_arg(args
, unsigned char *);
643 arglen
= va_arg(args
, int);
644 memcpy(p
, argp
, arglen
);
648 argp
= va_arg(args
, unsigned char *);
649 arglen
= strlen(argp
);
650 PUT_32BIT(p
, arglen
);
651 memcpy(p
+ 4, argp
, arglen
);
655 bn
= va_arg(args
, Bignum
);
656 p
+= ssh1_write_bignum(p
, bn
);
665 static int ssh_versioncmp(char *a
, char *b
) {
667 unsigned long av
, bv
;
669 av
= strtoul(a
, &ae
, 10);
670 bv
= strtoul(b
, &be
, 10);
671 if (av
!= bv
) return (av
< bv ?
-1 : +1);
672 if (*ae
== '.') ae
++;
673 if (*be
== '.') be
++;
674 av
= strtoul(ae
, &ae
, 10);
675 bv
= strtoul(be
, &be
, 10);
676 if (av
!= bv
) return (av
< bv ?
-1 : +1);
682 * Utility routine for putting an SSH-protocol `string' into a SHA
686 static void sha_string(SHA_State
*s
, void *str
, int len
) {
687 unsigned char lenblk
[4];
688 PUT_32BIT(lenblk
, len
);
689 SHA_Bytes(s
, lenblk
, 4);
690 SHA_Bytes(s
, str
, len
);
694 * SSH2 packet construction functions.
696 static void ssh2_pkt_adddata(void *data
, int len
) {
697 pktout
.length
+= len
;
698 if (pktout
.maxlen
< pktout
.length
) {
699 pktout
.maxlen
= pktout
.length
+ 256;
700 pktout
.data
= (pktout
.data
== NULL ?
malloc(pktout
.maxlen
+APIEXTRA
) :
701 realloc(pktout
.data
, pktout
.maxlen
+APIEXTRA
));
703 fatalbox("Out of memory");
705 memcpy(pktout
.data
+pktout
.length
-len
, data
, len
);
707 static void ssh2_pkt_addbyte(unsigned char byte
) {
708 ssh2_pkt_adddata(&byte
, 1);
710 static void ssh2_pkt_init(int pkt_type
) {
712 ssh2_pkt_addbyte((unsigned char)pkt_type
);
714 static void ssh2_pkt_addbool(unsigned char value
) {
715 ssh2_pkt_adddata(&value
, 1);
717 static void ssh2_pkt_adduint32(unsigned long value
) {
720 ssh2_pkt_adddata(x
, 4);
722 static void ssh2_pkt_addstring_start(void) {
723 ssh2_pkt_adduint32(0);
724 pktout
.savedpos
= pktout
.length
;
726 static void ssh2_pkt_addstring_str(char *data
) {
727 ssh2_pkt_adddata(data
, strlen(data
));
728 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
729 pktout
.length
- pktout
.savedpos
);
731 static void ssh2_pkt_addstring_data(char *data
, int len
) {
732 ssh2_pkt_adddata(data
, len
);
733 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
734 pktout
.length
- pktout
.savedpos
);
736 static void ssh2_pkt_addstring(char *data
) {
737 ssh2_pkt_addstring_start();
738 ssh2_pkt_addstring_str(data
);
740 static char *ssh2_mpint_fmt(Bignum b
, int *len
) {
743 p
= malloc(n
* 2 + 1);
745 fatalbox("out of memory");
747 for (i
= 0; i
< n
; i
++) {
748 p
[i
*2+1] = (b
[n
-i
] >> 8) & 0xFF;
749 p
[i
*2+2] = (b
[n
-i
] ) & 0xFF;
752 while (p
[i
] == 0 && (p
[i
+1] & 0x80) == 0)
754 memmove(p
, p
+i
, n
*2+1-i
);
758 static void ssh2_pkt_addmp(Bignum b
) {
761 p
= ssh2_mpint_fmt(b
, &len
);
762 ssh2_pkt_addstring_start();
763 ssh2_pkt_addstring_data(p
, len
);
766 static void ssh2_pkt_send(void) {
767 int cipherblk
, maclen
, padding
, i
;
768 static unsigned long outgoing_sequence
= 0;
771 * Add padding. At least four bytes, and must also bring total
772 * length (minus MAC) up to a multiple of the block size.
774 cipherblk
= cipher ? cipher
->blksize
: 8; /* block size */
775 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
777 padding
+= (cipherblk
- (pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
778 pktout
.data
[4] = padding
;
779 for (i
= 0; i
< padding
; i
++)
780 pktout
.data
[pktout
.length
+ i
] = random_byte();
781 PUT_32BIT(pktout
.data
, pktout
.length
+ padding
- 4);
783 csmac
->generate(pktout
.data
, pktout
.length
+ padding
,
785 outgoing_sequence
++; /* whether or not we MACed */
788 debug(("Sending packet len=%d\r\n", pktout
.length
+padding
));
789 for (i
= 0; i
< pktout
.length
+padding
; i
++)
790 debug((" %02x", (unsigned char)pktout
.data
[i
]));
795 cscipher
->encrypt(pktout
.data
, pktout
.length
+ padding
);
796 maclen
= csmac ? csmac
->len
: 0;
798 sk_write(s
, pktout
.data
, pktout
.length
+ padding
+ maclen
);
802 void bndebug(char *string
, Bignum b
) {
805 p
= ssh2_mpint_fmt(b
, &len
);
806 debug(("%s", string
));
807 for (i
= 0; i
< len
; i
++)
808 debug((" %02x", p
[i
]));
814 static void sha_mpint(SHA_State
*s
, Bignum b
) {
817 p
= ssh2_mpint_fmt(b
, &len
);
818 sha_string(s
, p
, len
);
823 * SSH2 packet decode functions.
825 static unsigned long ssh2_pkt_getuint32(void) {
827 if (pktin
.length
- pktin
.savedpos
< 4)
828 return 0; /* arrgh, no way to decline (FIXME?) */
829 value
= GET_32BIT(pktin
.data
+pktin
.savedpos
);
833 static void ssh2_pkt_getstring(char **p
, int *length
) {
835 if (pktin
.length
- pktin
.savedpos
< 4)
837 *length
= GET_32BIT(pktin
.data
+pktin
.savedpos
);
839 if (pktin
.length
- pktin
.savedpos
< *length
)
841 *p
= pktin
.data
+pktin
.savedpos
;
842 pktin
.savedpos
+= *length
;
844 static Bignum
ssh2_pkt_getmp(void) {
849 ssh2_pkt_getstring(&p
, &length
);
853 bombout(("internal error: Can't handle negative mpints"));
856 b
= newbn((length
+1)/2);
857 for (i
= 0; i
< length
; i
++) {
860 b
[j
/2+1] |= ((unsigned char)p
[i
]) << 8;
862 b
[j
/2+1] |= ((unsigned char)p
[i
]);
864 while (b
[0] > 1 && b
[b
[0]] == 0) b
[0]--;
868 static int do_ssh_init(unsigned char c
) {
870 static char version
[10];
871 static char vstring
[80];
872 static char vlog
[sizeof(vstring
)+20];
877 /* Search for the string "SSH-" in the input. */
880 static const int transS
[] = { 1, 2, 2, 1 };
881 static const int transH
[] = { 0, 0, 3, 0 };
882 static const int transminus
[] = { 0, 0, 0, -1 };
883 if (c
== 'S') i
= transS
[i
];
884 else if (c
== 'H') i
= transH
[i
];
885 else if (c
== '-') i
= transminus
[i
];
889 crReturn(1); /* get another character */
892 strcpy(vstring
, "SSH-");
896 crReturn(1); /* get another char */
897 if (vsp
< vstring
+sizeof(vstring
)-1)
903 } else if (i
< sizeof(version
)-1)
910 rdpkt2_state
.incoming_sequence
= 0;
913 sprintf(vlog
, "Server version: %s", vstring
);
914 vlog
[strcspn(vlog
, "\r\n")] = '\0';
918 * Server version "1.99" means we can choose whether we use v1
919 * or v2 protocol. Choice is based on cfg.sshprot.
921 if (ssh_versioncmp(version
, cfg
.sshprot
== 1 ?
"2.0" : "1.99") >= 0) {
923 * This is a v2 server. Begin v2 protocol.
925 char *verstring
= "SSH-2.0-PuTTY";
928 * Hash our version string and their version string.
930 sha_string(&exhash
, verstring
, strlen(verstring
));
931 sha_string(&exhash
, vstring
, strcspn(vstring
, "\r\n"));
932 sprintf(vstring
, "%s\n", verstring
);
933 sprintf(vlog
, "We claim version: %s", verstring
);
935 logevent("Using SSH protocol version 2");
936 sk_write(s
, vstring
, strlen(vstring
));
937 ssh_protocol
= ssh2_protocol
;
939 s_rdpkt
= ssh2_rdpkt
;
942 * This is a v1 server. Begin v1 protocol.
944 sprintf(vstring
, "SSH-%s-PuTTY\n",
945 (ssh_versioncmp(version
, "1.5") <= 0 ? version
: "1.5"));
946 sprintf(vlog
, "We claim version: %s", vstring
);
947 vlog
[strcspn(vlog
, "\r\n")] = '\0';
949 logevent("Using SSH protocol version 1");
950 sk_write(s
, vstring
, strlen(vstring
));
951 ssh_protocol
= ssh1_protocol
;
953 s_rdpkt
= ssh1_rdpkt
;
959 static void ssh_gotdata(unsigned char *data
, int datalen
)
964 * To begin with, feed the characters one by one to the
965 * protocol initialisation / selection function do_ssh_init().
966 * When that returns 0, we're done with the initial greeting
967 * exchange and can move on to packet discipline.
972 crReturnV
; /* more data please */
973 ret
= do_ssh_init(*data
);
980 * We emerge from that loop when the initial negotiation is
981 * over and we have selected an s_rdpkt function. Now pass
982 * everything to s_rdpkt, and then pass the resulting packets
983 * to the proper protocol handler.
988 while (datalen
> 0) {
989 if ( s_rdpkt(&data
, &datalen
) == 0 ) {
990 ssh_protocol(NULL
, 0, 1);
991 if (ssh_state
== SSH_STATE_CLOSED
) {
1001 static int ssh_receive(Socket s
, int urgent
, char *data
, int len
) {
1003 /* Connection has closed. */
1008 ssh_gotdata (data
, len
);
1009 if (ssh_state
== SSH_STATE_CLOSED
) {
1020 * Connect to specified host and port.
1021 * Returns an error message, or NULL on success.
1022 * Also places the canonical host name into `realhost'.
1024 static char *connect_to_host(char *host
, int port
, char **realhost
)
1033 savedhost
= malloc(1+strlen(host
));
1035 fatalbox("Out of memory");
1036 strcpy(savedhost
, host
);
1039 port
= 22; /* default ssh port */
1052 addr
= sk_namelookup(host
, realhost
);
1053 if ( (err
= sk_addr_error(addr
)) )
1063 s
= sk_new(addr
, port
, ssh_receive
);
1064 if ( (err
= sk_socket_error(s
)) )
1068 sk_write(s
, "connect ", 8);
1069 sk_write(s
, FWhost
, strlen(FWhost
));
1072 sprintf(buf
, " %d\n", FWport
);
1073 sk_write(s
, buf
, strlen(buf
));
1081 * Handle the key exchange and user authentication phases.
1083 static int do_ssh1_login(unsigned char *in
, int inlen
, int ispkt
)
1086 unsigned char *rsabuf
, *keystr1
, *keystr2
;
1087 unsigned char cookie
[8];
1088 struct RSAKey servkey
, hostkey
;
1089 struct MD5Context md5c
;
1090 static unsigned long supported_ciphers_mask
, supported_auths_mask
;
1091 static int tried_publickey
;
1092 static unsigned char session_id
[16];
1094 static char username
[100];
1098 if (!ispkt
) crWaitUntil(ispkt
);
1100 if (pktin
.type
!= SSH1_SMSG_PUBLIC_KEY
) {
1101 bombout(("Public key packet not received"));
1105 logevent("Received public keys");
1107 memcpy(cookie
, pktin
.body
, 8);
1109 i
= makekey(pktin
.body
+8, &servkey
, &keystr1
, 0);
1110 j
= makekey(pktin
.body
+8+i
, &hostkey
, &keystr2
, 0);
1113 * Log the host key fingerprint.
1117 logevent("Host key fingerprint is:");
1118 strcpy(logmsg
, " ");
1119 hostkey
.comment
= NULL
;
1120 rsa_fingerprint(logmsg
+strlen(logmsg
), sizeof(logmsg
)-strlen(logmsg
),
1125 supported_ciphers_mask
= GET_32BIT(pktin
.body
+12+i
+j
);
1126 supported_auths_mask
= GET_32BIT(pktin
.body
+16+i
+j
);
1129 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
1130 MD5Update(&md5c
, keystr1
, servkey
.bytes
);
1131 MD5Update(&md5c
, pktin
.body
, 8);
1132 MD5Final(session_id
, &md5c
);
1134 for (i
=0; i
<32; i
++)
1135 session_key
[i
] = random_byte();
1137 len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
1139 rsabuf
= malloc(len
);
1141 fatalbox("Out of memory");
1144 * Verify the host key.
1148 * First format the key into a string.
1150 int len
= rsastr_len(&hostkey
);
1151 char fingerprint
[100];
1152 char *keystr
= malloc(len
);
1154 fatalbox("Out of memory");
1155 rsastr_fmt(keystr
, &hostkey
);
1156 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
1157 verify_ssh_host_key(savedhost
, savedport
, "rsa", keystr
, fingerprint
);
1161 for (i
=0; i
<32; i
++) {
1162 rsabuf
[i
] = session_key
[i
];
1164 rsabuf
[i
] ^= session_id
[i
];
1167 if (hostkey
.bytes
> servkey
.bytes
) {
1168 rsaencrypt(rsabuf
, 32, &servkey
);
1169 rsaencrypt(rsabuf
, servkey
.bytes
, &hostkey
);
1171 rsaencrypt(rsabuf
, 32, &hostkey
);
1172 rsaencrypt(rsabuf
, hostkey
.bytes
, &servkey
);
1175 logevent("Encrypted session key");
1177 cipher_type
= cfg
.cipher
== CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH
:
1178 cfg
.cipher
== CIPHER_DES ? SSH_CIPHER_DES
:
1180 if ((supported_ciphers_mask
& (1 << cipher_type
)) == 0) {
1181 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1182 cipher_type
= SSH_CIPHER_3DES
;
1184 switch (cipher_type
) {
1185 case SSH_CIPHER_3DES
: logevent("Using 3DES encryption"); break;
1186 case SSH_CIPHER_DES
: logevent("Using single-DES encryption"); break;
1187 case SSH_CIPHER_BLOWFISH
: logevent("Using Blowfish encryption"); break;
1190 send_packet(SSH1_CMSG_SESSION_KEY
,
1191 PKT_CHAR
, cipher_type
,
1192 PKT_DATA
, cookie
, 8,
1193 PKT_CHAR
, (len
*8) >> 8, PKT_CHAR
, (len
*8) & 0xFF,
1194 PKT_DATA
, rsabuf
, len
,
1198 logevent("Trying to enable encryption...");
1202 cipher
= cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
1203 cipher_type
== SSH_CIPHER_DES ?
&ssh_des
:
1205 cipher
->sesskey(session_key
);
1209 if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1210 bombout(("Encryption not successfully enabled"));
1214 logevent("Successfully started encryption");
1220 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
1221 c_write("login as: ", 10);
1224 crWaitUntil(!ispkt
);
1225 while (inlen
--) switch (c
= *in
++) {
1232 c_write("\b \b", 3);
1238 c_write("\b \b", 3);
1247 if (((c
>= ' ' && c
<= '~') ||
1248 ((unsigned char)c
>= 160)) && pos
< 40) {
1249 username
[pos
++] = c
;
1256 username
[strcspn(username
, "\n\r")] = '\0';
1259 strncpy(username
, cfg
.username
, 99);
1260 username
[99] = '\0';
1261 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
1262 sprintf(stuff
, "Sent username \"%s\".\r\n", username
);
1263 c_write(stuff
, strlen(stuff
));
1267 send_packet(SSH1_CMSG_USER
, PKT_STR
, username
, PKT_END
);
1269 char userlog
[20+sizeof(username
)];
1270 sprintf(userlog
, "Sent username \"%s\"", username
);
1277 tried_publickey
= 0;
1279 while (pktin
.type
== SSH1_SMSG_FAILURE
) {
1280 static char password
[100];
1281 static char prompt
[200];
1284 static int pwpkt_type
;
1286 * Show password prompt, having first obtained it via a TIS
1287 * or CryptoCard exchange if we're doing TIS or CryptoCard
1290 pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
1291 if (agent_exists()) {
1293 * Attempt RSA authentication using Pageant.
1295 static unsigned char request
[5], *response
, *p
;
1296 static int responselen
;
1297 static int i
, nkeys
;
1298 static int authed
= FALSE
;
1301 logevent("Pageant is running. Requesting keys.");
1303 /* Request the keys held by the agent. */
1304 PUT_32BIT(request
, 1);
1305 request
[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES
;
1306 agent_query(request
, 5, &r
, &responselen
);
1307 response
= (unsigned char *)r
;
1310 nkeys
= GET_32BIT(p
); p
+= 4;
1311 { char buf
[64]; sprintf(buf
, "Pageant has %d keys", nkeys
);
1313 for (i
= 0; i
< nkeys
; i
++) {
1314 static struct RSAKey key
;
1315 static Bignum challenge
;
1316 static char *commentp
;
1317 static int commentlen
;
1319 { char buf
[64]; sprintf(buf
, "Trying Pageant key #%d", i
);
1322 p
+= ssh1_read_bignum(p
, &key
.exponent
);
1323 p
+= ssh1_read_bignum(p
, &key
.modulus
);
1324 commentlen
= GET_32BIT(p
); p
+= 4;
1325 commentp
= p
; p
+= commentlen
;
1326 send_packet(SSH1_CMSG_AUTH_RSA
,
1327 PKT_BIGNUM
, key
.modulus
, PKT_END
);
1329 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
1330 logevent("Key refused");
1333 logevent("Received RSA challenge");
1334 ssh1_read_bignum(pktin
.body
, &challenge
);
1336 char *agentreq
, *q
, *ret
;
1338 len
= 1 + 4; /* message type, bit count */
1339 len
+= ssh1_bignum_length(key
.exponent
);
1340 len
+= ssh1_bignum_length(key
.modulus
);
1341 len
+= ssh1_bignum_length(challenge
);
1342 len
+= 16; /* session id */
1343 len
+= 4; /* response format */
1344 agentreq
= malloc(4 + len
);
1345 PUT_32BIT(agentreq
, len
);
1347 *q
++ = SSH_AGENTC_RSA_CHALLENGE
;
1348 PUT_32BIT(q
, ssh1_bignum_bitcount(key
.modulus
));
1350 q
+= ssh1_write_bignum(q
, key
.exponent
);
1351 q
+= ssh1_write_bignum(q
, key
.modulus
);
1352 q
+= ssh1_write_bignum(q
, challenge
);
1353 memcpy(q
, session_id
, 16); q
+= 16;
1354 PUT_32BIT(q
, 1); /* response format */
1355 agent_query(agentreq
, len
+4, &ret
, &retlen
);
1358 if (ret
[4] == SSH_AGENT_RSA_RESPONSE
) {
1359 logevent("Sending Pageant's response");
1360 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
1361 PKT_DATA
, ret
+5, 16, PKT_END
);
1364 if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
1365 logevent("Pageant's response accepted");
1366 if (flags
& FLAG_VERBOSE
) {
1367 c_write("Authenticated using RSA key \"",
1369 c_write(commentp
, commentlen
);
1370 c_write("\" from agent\r\n", 14);
1374 logevent("Pageant's response not accepted");
1376 logevent("Pageant failed to answer challenge");
1380 logevent("No reply received from Pageant");
1383 freebn(key
.exponent
);
1384 freebn(key
.modulus
);
1393 if (*cfg
.keyfile
&& !tried_publickey
)
1394 pwpkt_type
= SSH1_CMSG_AUTH_RSA
;
1396 if (pktin
.type
== SSH1_SMSG_FAILURE
&&
1398 (supported_auths_mask
& (1<<SSH1_AUTH_TIS
))) {
1399 pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
1400 logevent("Requested TIS authentication");
1401 send_packet(SSH1_CMSG_AUTH_TIS
, PKT_END
);
1403 if (pktin
.type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
1404 logevent("TIS authentication declined");
1405 if (flags
& FLAG_INTERACTIVE
)
1406 c_write("TIS authentication refused.\r\n", 29);
1408 int challengelen
= ((pktin
.body
[0] << 24) |
1409 (pktin
.body
[1] << 16) |
1410 (pktin
.body
[2] << 8) |
1412 logevent("Received TIS challenge");
1413 if (challengelen
> sizeof(prompt
)-1)
1414 challengelen
= sizeof(prompt
)-1; /* prevent overrun */
1415 memcpy(prompt
, pktin
.body
+4, challengelen
);
1416 prompt
[challengelen
] = '\0';
1419 if (pktin
.type
== SSH1_SMSG_FAILURE
&&
1421 (supported_auths_mask
& (1<<SSH1_AUTH_CCARD
))) {
1422 pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
1423 logevent("Requested CryptoCard authentication");
1424 send_packet(SSH1_CMSG_AUTH_CCARD
, PKT_END
);
1426 if (pktin
.type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
1427 logevent("CryptoCard authentication declined");
1428 c_write("CryptoCard authentication refused.\r\n", 29);
1430 int challengelen
= ((pktin
.body
[0] << 24) |
1431 (pktin
.body
[1] << 16) |
1432 (pktin
.body
[2] << 8) |
1434 logevent("Received CryptoCard challenge");
1435 if (challengelen
> sizeof(prompt
)-1)
1436 challengelen
= sizeof(prompt
)-1; /* prevent overrun */
1437 memcpy(prompt
, pktin
.body
+4, challengelen
);
1438 strncpy(prompt
+ challengelen
, "\r\nResponse : ",
1439 sizeof(prompt
)-challengelen
);
1440 prompt
[sizeof(prompt
)-1] = '\0';
1443 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
1444 sprintf(prompt
, "%.90s@%.90s's password: ",
1445 username
, savedhost
);
1447 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
1448 char *comment
= NULL
;
1449 if (flags
& FLAG_VERBOSE
)
1450 c_write("Trying public key authentication.\r\n", 35);
1451 if (!rsakey_encrypted(cfg
.keyfile
, &comment
)) {
1452 if (flags
& FLAG_VERBOSE
)
1453 c_write("No passphrase required.\r\n", 25);
1456 sprintf(prompt
, "Passphrase for key \"%.100s\": ", comment
);
1460 if (ssh_get_password
) {
1461 if (!ssh_get_password(prompt
, password
, sizeof(password
))) {
1463 * get_password failed to get a password (for
1464 * example because one was supplied on the command
1465 * line which has already failed to work).
1468 logevent("No more passwords to try");
1469 ssh_state
= SSH_STATE_CLOSED
;
1473 c_write(prompt
, strlen(prompt
));
1477 crWaitUntil(!ispkt
);
1478 while (inlen
--) switch (c
= *in
++) {
1495 if (((c
>= ' ' && c
<= '~') ||
1496 ((unsigned char)c
>= 160)) && pos
< sizeof(password
))
1497 password
[pos
++] = c
;
1505 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
1507 * Try public key authentication with the specified
1510 static struct RSAKey pubkey
;
1511 static Bignum challenge
, response
;
1513 static unsigned char buffer
[32];
1515 tried_publickey
= 1;
1516 i
= loadrsakey(cfg
.keyfile
, &pubkey
, NULL
, password
);
1518 c_write("Couldn't load public key from ", 30);
1519 c_write(cfg
.keyfile
, strlen(cfg
.keyfile
));
1520 c_write(".\r\n", 3);
1521 continue; /* go and try password */
1524 c_write("Wrong passphrase.\r\n", 19);
1525 tried_publickey
= 0;
1526 continue; /* try again */
1530 * Send a public key attempt.
1532 send_packet(SSH1_CMSG_AUTH_RSA
,
1533 PKT_BIGNUM
, pubkey
.modulus
, PKT_END
);
1536 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1537 c_write("Server refused our public key.\r\n", 32);
1538 continue; /* go and try password */
1540 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
1541 bombout(("Bizarre response to offer of public key"));
1544 ssh1_read_bignum(pktin
.body
, &challenge
);
1545 response
= rsadecrypt(challenge
, &pubkey
);
1546 freebn(pubkey
.private_exponent
); /* burn the evidence */
1548 for (i
= 0; i
< 32; i
+= 2) {
1549 buffer
[i
] = response
[16-i
/2] >> 8;
1550 buffer
[i
+1] = response
[16-i
/2] & 0xFF;
1554 MD5Update(&md5c
, buffer
, 32);
1555 MD5Update(&md5c
, session_id
, 16);
1556 MD5Final(buffer
, &md5c
);
1558 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
1559 PKT_DATA
, buffer
, 16, PKT_END
);
1562 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1563 if (flags
& FLAG_VERBOSE
)
1564 c_write("Failed to authenticate with our public key.\r\n",
1566 continue; /* go and try password */
1567 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1568 bombout(("Bizarre response to RSA authentication response"));
1572 break; /* we're through! */
1574 send_packet(pwpkt_type
, PKT_STR
, password
, PKT_END
);
1576 logevent("Sent password");
1577 memset(password
, 0, strlen(password
));
1579 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1580 if (flags
& FLAG_VERBOSE
)
1581 c_write("Access denied\r\n", 15);
1582 logevent("Authentication refused");
1583 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
1584 logevent("Received disconnect request");
1585 ssh_state
= SSH_STATE_CLOSED
;
1587 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1588 bombout(("Strange packet received, type %d", pktin
.type
));
1593 logevent("Authentication successful");
1598 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
) {
1603 while (!do_ssh1_login(in
, inlen
, ispkt
)) {
1606 if (ssh_state
== SSH_STATE_CLOSED
)
1609 if (cfg
.agentfwd
&& agent_exists()) {
1610 logevent("Requesting agent forwarding");
1611 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
1612 do { crReturnV
; } while (!ispkt
);
1613 if (pktin
.type
!= SSH1_SMSG_SUCCESS
&& pktin
.type
!= SSH1_SMSG_FAILURE
) {
1614 bombout(("Protocol confusion"));
1616 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1617 logevent("Agent forwarding refused");
1619 logevent("Agent forwarding enabled");
1623 send_packet(SSH1_CMSG_REQUEST_PTY
,
1624 PKT_STR
, cfg
.termtype
,
1625 PKT_INT
, rows
, PKT_INT
, cols
,
1626 PKT_INT
, 0, PKT_INT
, 0,
1629 ssh_state
= SSH_STATE_INTERMED
;
1630 do { crReturnV
; } while (!ispkt
);
1631 if (pktin
.type
!= SSH1_SMSG_SUCCESS
&& pktin
.type
!= SSH1_SMSG_FAILURE
) {
1632 bombout(("Protocol confusion"));
1634 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1635 c_write("Server refused to allocate pty\r\n", 32);
1637 logevent("Allocated pty");
1640 if (*cfg
.remote_cmd
)
1641 send_packet(SSH1_CMSG_EXEC_CMD
, PKT_STR
, cfg
.remote_cmd
, PKT_END
);
1643 send_packet(SSH1_CMSG_EXEC_SHELL
, PKT_END
);
1644 logevent("Started session");
1646 ssh_state
= SSH_STATE_SESSION
;
1651 ssh_channels
= newtree234(ssh_channelcmp
);
1656 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
1657 pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
1658 long len
= GET_32BIT(pktin
.body
);
1659 from_backend(pktin
.type
== SSH1_SMSG_STDERR_DATA
,
1661 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
1662 ssh_state
= SSH_STATE_CLOSED
;
1663 logevent("Received disconnect request");
1665 } else if (pktin
.type
== SSH1_SMSG_AGENT_OPEN
) {
1666 /* Remote side is trying to open a channel to talk to our
1667 * agent. Give them back a local channel number. */
1669 struct ssh_channel
*c
;
1671 for (c
= first234(ssh_channels
, &e
); c
; c
= next234(&e
)) {
1673 break; /* found a free number */
1676 c
= malloc(sizeof(struct ssh_channel
));
1677 c
->remoteid
= GET_32BIT(pktin
.body
);
1680 c
->type
= SSH1_SMSG_AGENT_OPEN
; /* identify channel type */
1681 c
->u
.a
.lensofar
= 0;
1682 add234(ssh_channels
, c
);
1683 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
1684 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
1686 } else if (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE
||
1687 pktin
.type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
) {
1688 /* Remote side closes a channel. */
1689 unsigned i
= GET_32BIT(pktin
.body
);
1690 struct ssh_channel
*c
;
1691 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
1694 closetype
= (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
1 : 2);
1695 send_packet(pktin
.type
, PKT_INT
, c
->remoteid
, PKT_END
);
1696 c
->closes
|= closetype
;
1697 if (c
->closes
== 3) {
1698 del234(ssh_channels
, c
);
1702 } else if (pktin
.type
== SSH1_MSG_CHANNEL_DATA
) {
1703 /* Data sent down one of our channels. */
1704 int i
= GET_32BIT(pktin
.body
);
1705 int len
= GET_32BIT(pktin
.body
+4);
1706 unsigned char *p
= pktin
.body
+8;
1707 struct ssh_channel
*c
;
1708 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
1711 case SSH1_SMSG_AGENT_OPEN
:
1712 /* Data for an agent message. Buffer it. */
1714 if (c
->u
.a
.lensofar
< 4) {
1715 int l
= min(4 - c
->u
.a
.lensofar
, len
);
1716 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
, l
);
1717 p
+= l
; len
-= l
; c
->u
.a
.lensofar
+= l
;
1719 if (c
->u
.a
.lensofar
== 4) {
1720 c
->u
.a
.totallen
= 4 + GET_32BIT(c
->u
.a
.msglen
);
1721 c
->u
.a
.message
= malloc(c
->u
.a
.totallen
);
1722 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
1724 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
1725 int l
= min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
, len
);
1726 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
, l
);
1727 p
+= l
; len
-= l
; c
->u
.a
.lensofar
+= l
;
1729 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
1730 void *reply
, *sentreply
;
1732 agent_query(c
->u
.a
.message
, c
->u
.a
.totallen
,
1737 /* Fake SSH_AGENT_FAILURE. */
1738 sentreply
= "\0\0\0\1\5";
1741 send_packet(SSH1_MSG_CHANNEL_DATA
,
1742 PKT_INT
, c
->remoteid
,
1744 PKT_DATA
, sentreply
, replylen
,
1748 free(c
->u
.a
.message
);
1749 c
->u
.a
.lensofar
= 0;
1755 } else if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
1756 /* may be from EXEC_SHELL on some servers */
1757 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1758 /* may be from EXEC_SHELL on some servers
1759 * if no pty is available or in other odd cases. Ignore */
1760 } else if (pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
1761 send_packet(SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
1763 bombout(("Strange packet received: type %d", pktin
.type
));
1768 int len
= min(inlen
, 512);
1769 send_packet(SSH1_CMSG_STDIN_DATA
,
1770 PKT_INT
, len
, PKT_DATA
, in
, len
, PKT_END
);
1781 * Utility routine for decoding comma-separated strings in KEXINIT.
1783 static int in_commasep_string(char *needle
, char *haystack
, int haylen
) {
1784 int needlen
= strlen(needle
);
1787 * Is it at the start of the string?
1789 if (haylen
>= needlen
&& /* haystack is long enough */
1790 !memcmp(needle
, haystack
, needlen
) && /* initial match */
1791 (haylen
== needlen
|| haystack
[needlen
] == ',')
1792 /* either , or EOS follows */
1796 * If not, search for the next comma and resume after that.
1797 * If no comma found, terminate.
1799 while (haylen
> 0 && *haystack
!= ',')
1800 haylen
--, haystack
++;
1803 haylen
--, haystack
++; /* skip over comma itself */
1808 * SSH2 key creation method.
1810 static void ssh2_mkkey(Bignum K
, char *H
, char chr
, char *keyspace
) {
1812 /* First 20 bytes. */
1815 SHA_Bytes(&s
, H
, 20);
1816 SHA_Bytes(&s
, &chr
, 1);
1817 SHA_Bytes(&s
, H
, 20);
1818 SHA_Final(&s
, keyspace
);
1819 /* Next 20 bytes. */
1822 SHA_Bytes(&s
, H
, 20);
1823 SHA_Bytes(&s
, keyspace
, 20);
1824 SHA_Final(&s
, keyspace
+20);
1828 * Handle the SSH2 transport layer.
1830 static int do_ssh2_transport(unsigned char *in
, int inlen
, int ispkt
)
1834 static Bignum e
, f
, K
;
1835 static const struct ssh_mac
**maclist
;
1837 static const struct ssh_cipher
*cscipher_tobe
= NULL
;
1838 static const struct ssh_cipher
*sccipher_tobe
= NULL
;
1839 static const struct ssh_mac
*csmac_tobe
= NULL
;
1840 static const struct ssh_mac
*scmac_tobe
= NULL
;
1841 static const struct ssh_compress
*cscomp_tobe
= NULL
;
1842 static const struct ssh_compress
*sccomp_tobe
= NULL
;
1843 static char *hostkeydata
, *sigdata
, *keystr
, *fingerprint
;
1844 static int hostkeylen
, siglen
;
1845 static unsigned char exchange_hash
[20];
1846 static unsigned char keyspace
[40];
1847 static const struct ssh_cipher
*preferred_cipher
;
1853 * Set up the preferred cipher.
1855 if (cfg
.cipher
== CIPHER_BLOWFISH
) {
1856 preferred_cipher
= &ssh_blowfish_ssh2
;
1857 } else if (cfg
.cipher
== CIPHER_DES
) {
1858 logevent("Single DES not supported in SSH2; using 3DES");
1859 preferred_cipher
= &ssh_3des_ssh2
;
1860 } else if (cfg
.cipher
== CIPHER_3DES
) {
1861 preferred_cipher
= &ssh_3des_ssh2
;
1863 /* Shouldn't happen, but we do want to initialise to _something_. */
1864 preferred_cipher
= &ssh_3des_ssh2
;
1868 * Be prepared to work around the buggy MAC problem.
1871 maclist
= buggymacs
, nmacs
= lenof(buggymacs
);
1873 maclist
= macs
, nmacs
= lenof(macs
);
1877 * Construct and send our key exchange packet.
1879 ssh2_pkt_init(SSH2_MSG_KEXINIT
);
1880 for (i
= 0; i
< 16; i
++)
1881 ssh2_pkt_addbyte((unsigned char)random_byte());
1882 /* List key exchange algorithms. */
1883 ssh2_pkt_addstring_start();
1884 for (i
= 0; i
< lenof(kex_algs
); i
++) {
1885 ssh2_pkt_addstring_str(kex_algs
[i
]->name
);
1886 if (i
< lenof(kex_algs
)-1)
1887 ssh2_pkt_addstring_str(",");
1889 /* List server host key algorithms. */
1890 ssh2_pkt_addstring_start();
1891 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
1892 ssh2_pkt_addstring_str(hostkey_algs
[i
]->name
);
1893 if (i
< lenof(hostkey_algs
)-1)
1894 ssh2_pkt_addstring_str(",");
1896 /* List client->server encryption algorithms. */
1897 ssh2_pkt_addstring_start();
1898 for (i
= 0; i
< lenof(ciphers
)+1; i
++) {
1899 const struct ssh_cipher
*c
= i
==0 ? preferred_cipher
: ciphers
[i
-1];
1900 ssh2_pkt_addstring_str(c
->name
);
1901 if (i
< lenof(ciphers
))
1902 ssh2_pkt_addstring_str(",");
1904 /* List server->client encryption algorithms. */
1905 ssh2_pkt_addstring_start();
1906 for (i
= 0; i
< lenof(ciphers
)+1; i
++) {
1907 const struct ssh_cipher
*c
= i
==0 ? preferred_cipher
: ciphers
[i
-1];
1908 ssh2_pkt_addstring_str(c
->name
);
1909 if (i
< lenof(ciphers
))
1910 ssh2_pkt_addstring_str(",");
1912 /* List client->server MAC algorithms. */
1913 ssh2_pkt_addstring_start();
1914 for (i
= 0; i
< nmacs
; i
++) {
1915 ssh2_pkt_addstring_str(maclist
[i
]->name
);
1917 ssh2_pkt_addstring_str(",");
1919 /* List server->client MAC algorithms. */
1920 ssh2_pkt_addstring_start();
1921 for (i
= 0; i
< nmacs
; i
++) {
1922 ssh2_pkt_addstring_str(maclist
[i
]->name
);
1924 ssh2_pkt_addstring_str(",");
1926 /* List client->server compression algorithms. */
1927 ssh2_pkt_addstring_start();
1928 for (i
= 0; i
< lenof(compressions
); i
++) {
1929 ssh2_pkt_addstring_str(compressions
[i
]->name
);
1930 if (i
< lenof(compressions
)-1)
1931 ssh2_pkt_addstring_str(",");
1933 /* List server->client compression algorithms. */
1934 ssh2_pkt_addstring_start();
1935 for (i
= 0; i
< lenof(compressions
); i
++) {
1936 ssh2_pkt_addstring_str(compressions
[i
]->name
);
1937 if (i
< lenof(compressions
)-1)
1938 ssh2_pkt_addstring_str(",");
1940 /* List client->server languages. Empty list. */
1941 ssh2_pkt_addstring_start();
1942 /* List server->client languages. Empty list. */
1943 ssh2_pkt_addstring_start();
1944 /* First KEX packet does _not_ follow, because we're not that brave. */
1945 ssh2_pkt_addbool(FALSE
);
1947 ssh2_pkt_adduint32(0);
1948 sha_string(&exhash
, pktout
.data
+5, pktout
.length
-5);
1951 if (!ispkt
) crWaitUntil(ispkt
);
1952 sha_string(&exhash
, pktin
.data
+5, pktin
.length
-5);
1955 * Now examine the other side's KEXINIT to see what we're up
1958 if (pktin
.type
!= SSH2_MSG_KEXINIT
) {
1959 bombout(("expected key exchange packet from server"));
1962 kex
= NULL
; hostkey
= NULL
; cscipher_tobe
= NULL
; sccipher_tobe
= NULL
;
1963 csmac_tobe
= NULL
; scmac_tobe
= NULL
; cscomp_tobe
= NULL
; sccomp_tobe
= NULL
;
1964 pktin
.savedpos
+= 16; /* skip garbage cookie */
1965 ssh2_pkt_getstring(&str
, &len
); /* key exchange algorithms */
1966 for (i
= 0; i
< lenof(kex_algs
); i
++) {
1967 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
1972 ssh2_pkt_getstring(&str
, &len
); /* host key algorithms */
1973 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
1974 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
1975 hostkey
= hostkey_algs
[i
];
1979 ssh2_pkt_getstring(&str
, &len
); /* client->server cipher */
1980 for (i
= 0; i
< lenof(ciphers
)+1; i
++) {
1981 const struct ssh_cipher
*c
= i
==0 ? preferred_cipher
: ciphers
[i
-1];
1982 if (in_commasep_string(c
->name
, str
, len
)) {
1987 ssh2_pkt_getstring(&str
, &len
); /* server->client cipher */
1988 for (i
= 0; i
< lenof(ciphers
)+1; i
++) {
1989 const struct ssh_cipher
*c
= i
==0 ? preferred_cipher
: ciphers
[i
-1];
1990 if (in_commasep_string(c
->name
, str
, len
)) {
1995 ssh2_pkt_getstring(&str
, &len
); /* client->server mac */
1996 for (i
= 0; i
< nmacs
; i
++) {
1997 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
1998 csmac_tobe
= maclist
[i
];
2002 ssh2_pkt_getstring(&str
, &len
); /* server->client mac */
2003 for (i
= 0; i
< nmacs
; i
++) {
2004 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
2005 scmac_tobe
= maclist
[i
];
2009 ssh2_pkt_getstring(&str
, &len
); /* client->server compression */
2010 for (i
= 0; i
< lenof(compressions
); i
++) {
2011 if (in_commasep_string(compressions
[i
]->name
, str
, len
)) {
2012 cscomp_tobe
= compressions
[i
];
2016 ssh2_pkt_getstring(&str
, &len
); /* server->client compression */
2017 for (i
= 0; i
< lenof(compressions
); i
++) {
2018 if (in_commasep_string(compressions
[i
]->name
, str
, len
)) {
2019 sccomp_tobe
= compressions
[i
];
2025 * Currently we only support Diffie-Hellman and DSS, so let's
2026 * bomb out if those aren't selected.
2028 if (kex
!= &ssh_diffiehellman
|| hostkey
!= &ssh_dss
) {
2029 bombout(("internal fault: chaos in SSH 2 transport layer"));
2034 * Now we begin the fun. Generate and send e for Diffie-Hellman.
2037 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT
);
2042 if (pktin
.type
!= SSH2_MSG_KEXDH_REPLY
) {
2043 bombout(("expected key exchange packet from server"));
2046 ssh2_pkt_getstring(&hostkeydata
, &hostkeylen
);
2047 f
= ssh2_pkt_getmp();
2048 ssh2_pkt_getstring(&sigdata
, &siglen
);
2052 sha_string(&exhash
, hostkeydata
, hostkeylen
);
2053 sha_mpint(&exhash
, e
);
2054 sha_mpint(&exhash
, f
);
2055 sha_mpint(&exhash
, K
);
2056 SHA_Final(&exhash
, exchange_hash
);
2059 debug(("Exchange hash is:\r\n"));
2060 for (i
= 0; i
< 20; i
++)
2061 debug((" %02x", exchange_hash
[i
]));
2065 hostkey
->setkey(hostkeydata
, hostkeylen
);
2066 if (!hostkey
->verifysig(sigdata
, siglen
, exchange_hash
, 20)) {
2067 bombout(("Server failed host key check"));
2072 * Expect SSH2_MSG_NEWKEYS from server.
2075 if (pktin
.type
!= SSH2_MSG_NEWKEYS
) {
2076 bombout(("expected new-keys packet from server"));
2081 * Authenticate remote host: verify host key. (We've already
2082 * checked the signature of the exchange hash.)
2084 keystr
= hostkey
->fmtkey();
2085 fingerprint
= hostkey
->fingerprint();
2086 verify_ssh_host_key(savedhost
, savedport
, hostkey
->keytype
,
2087 keystr
, fingerprint
);
2088 logevent("Host key fingerprint is:");
2089 logevent(fingerprint
);
2094 * Send SSH2_MSG_NEWKEYS.
2096 ssh2_pkt_init(SSH2_MSG_NEWKEYS
);
2100 * Create and initialise session keys.
2102 cscipher
= cscipher_tobe
;
2103 sccipher
= sccipher_tobe
;
2106 cscomp
= cscomp_tobe
;
2107 sccomp
= sccomp_tobe
;
2109 * Set IVs after keys.
2111 ssh2_mkkey(K
, exchange_hash
, 'C', keyspace
); cscipher
->setcskey(keyspace
);
2112 ssh2_mkkey(K
, exchange_hash
, 'D', keyspace
); cscipher
->setsckey(keyspace
);
2113 ssh2_mkkey(K
, exchange_hash
, 'A', keyspace
); cscipher
->setcsiv(keyspace
);
2114 ssh2_mkkey(K
, exchange_hash
, 'B', keyspace
); sccipher
->setsciv(keyspace
);
2115 ssh2_mkkey(K
, exchange_hash
, 'E', keyspace
); csmac
->setcskey(keyspace
);
2116 ssh2_mkkey(K
, exchange_hash
, 'F', keyspace
); scmac
->setsckey(keyspace
);
2119 * Now we're encrypting. Begin returning 1 to the protocol main
2120 * function so that other things can run on top of the
2121 * transport. If we ever see a KEXINIT, we must go back to the
2126 } while (!(ispkt
&& pktin
.type
== SSH2_MSG_KEXINIT
));
2127 goto begin_key_exchange
;
2133 * Handle the SSH2 userauth and connection layers.
2135 static void do_ssh2_authconn(unsigned char *in
, int inlen
, int ispkt
)
2137 static unsigned long remote_winsize
;
2138 static unsigned long remote_maxpkt
;
2143 * Request userauth protocol, and await a response to it.
2145 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
2146 ssh2_pkt_addstring("ssh-userauth");
2148 crWaitUntilV(ispkt
);
2149 if (pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
) {
2150 bombout(("Server refused user authentication protocol"));
2155 * FIXME: currently we support only password authentication.
2156 * (This places us technically in violation of the SSH2 spec.
2157 * We must fix this.)
2161 * Get a username and a password.
2163 static char username
[100];
2164 static char password
[100];
2168 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
2169 c_write("login as: ", 10);
2172 crWaitUntilV(!ispkt
);
2173 while (inlen
--) switch (c
= *in
++) {
2180 c_write("\b \b", 3);
2186 c_write("\b \b", 3);
2195 if (((c
>= ' ' && c
<= '~') ||
2196 ((unsigned char)c
>= 160)) && pos
< 40) {
2197 username
[pos
++] = c
;
2204 username
[strcspn(username
, "\n\r")] = '\0';
2207 strncpy(username
, cfg
.username
, 99);
2208 username
[99] = '\0';
2209 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
2210 sprintf(stuff
, "Using username \"%s\".\r\n", username
);
2211 c_write(stuff
, strlen(stuff
));
2215 if (ssh_get_password
) {
2217 sprintf(prompt
, "%.90s@%.90s's password: ", username
, savedhost
);
2218 if (!ssh_get_password(prompt
, password
, sizeof(password
))) {
2220 * get_password failed to get a password (for
2221 * example because one was supplied on the command
2222 * line which has already failed to work).
2225 logevent("No more passwords to try");
2226 ssh_state
= SSH_STATE_CLOSED
;
2230 c_write("password: ", 10);
2235 crWaitUntilV(!ispkt
);
2236 while (inlen
--) switch (c
= *in
++) {
2253 if (((c
>= ' ' && c
<= '~') ||
2254 ((unsigned char)c
>= 160)) && pos
< 40)
2255 password
[pos
++] = c
;
2262 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
2263 ssh2_pkt_addstring(username
);
2264 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2265 ssh2_pkt_addstring("password");
2266 ssh2_pkt_addbool(FALSE
);
2267 ssh2_pkt_addstring(password
);
2270 crWaitUntilV(ispkt
);
2271 if (pktin
.type
!= SSH2_MSG_USERAUTH_SUCCESS
) {
2272 c_write("Access denied\r\n", 15);
2273 logevent("Authentication refused");
2279 * Now we're authenticated for the connection protocol. The
2280 * connection protocol will automatically have started at this
2281 * point; there's no need to send SERVICE_REQUEST.
2285 * So now create a channel with a session in it.
2287 mainchan
= malloc(sizeof(struct ssh_channel
));
2288 mainchan
->localid
= 100; /* as good as any */
2289 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
2290 ssh2_pkt_addstring("session");
2291 ssh2_pkt_adduint32(mainchan
->localid
);
2292 ssh2_pkt_adduint32(0x8000UL
); /* our window size */
2293 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
2295 crWaitUntilV(ispkt
);
2296 if (pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
2297 bombout(("Server refused to open a session"));
2299 /* FIXME: error data comes back in FAILURE packet */
2301 if (ssh2_pkt_getuint32() != mainchan
->localid
) {
2302 bombout(("Server's channel confirmation cited wrong channel"));
2305 mainchan
->remoteid
= ssh2_pkt_getuint32();
2306 mainchan
->u
.v2
.remwindow
= ssh2_pkt_getuint32();
2307 mainchan
->u
.v2
.remmaxpkt
= ssh2_pkt_getuint32();
2308 mainchan
->u
.v2
.outbuffer
= NULL
;
2309 mainchan
->u
.v2
.outbuflen
= mainchan
->u
.v2
.outbufsize
= 0;
2310 logevent("Opened channel for session");
2313 * Now allocate a pty for the session.
2316 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
2317 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
2318 ssh2_pkt_addstring("pty-req");
2319 ssh2_pkt_addbool(1); /* want reply */
2320 ssh2_pkt_addstring(cfg
.termtype
);
2321 ssh2_pkt_adduint32(cols
);
2322 ssh2_pkt_adduint32(rows
);
2323 ssh2_pkt_adduint32(0); /* pixel width */
2324 ssh2_pkt_adduint32(0); /* pixel height */
2325 ssh2_pkt_addstring_start();
2326 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
2328 ssh_state
= SSH_STATE_INTERMED
;
2331 crWaitUntilV(ispkt
);
2332 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
2333 /* FIXME: be able to handle other channels here */
2334 if (ssh2_pkt_getuint32() != mainchan
->localid
)
2335 continue; /* wrong channel */
2336 mainchan
->u
.v2
.remwindow
+= ssh2_pkt_getuint32();
2338 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
2340 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
2341 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
2342 bombout(("Server got confused by pty request"));
2345 c_write("Server refused to allocate pty\r\n", 32);
2347 logevent("Allocated pty");
2352 * Start a shell or a remote command.
2354 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
2355 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
2356 if (*cfg
.remote_cmd
) {
2357 ssh2_pkt_addstring("exec");
2358 ssh2_pkt_addbool(1); /* want reply */
2359 ssh2_pkt_addstring(cfg
.remote_cmd
);
2361 ssh2_pkt_addstring("shell");
2362 ssh2_pkt_addbool(1); /* want reply */
2366 crWaitUntilV(ispkt
);
2367 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
2368 /* FIXME: be able to handle other channels here */
2369 if (ssh2_pkt_getuint32() != mainchan
->localid
)
2370 continue; /* wrong channel */
2371 mainchan
->u
.v2
.remwindow
+= ssh2_pkt_getuint32();
2373 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
2374 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
2375 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
2376 bombout(("Server got confused by shell/command request"));
2379 bombout(("Server refused to start a shell/command"));
2382 logevent("Started a shell/command");
2385 ssh_state
= SSH_STATE_SESSION
;
2395 static int try_send
;
2399 if (pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
2400 pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
2403 /* FIXME: be able to handle other channels here */
2404 if (ssh2_pkt_getuint32() != mainchan
->localid
)
2405 continue; /* wrong channel */
2406 if (pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
2407 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR
)
2408 continue; /* extended but not stderr */
2409 ssh2_pkt_getstring(&data
, &length
);
2411 from_backend(pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
,
2414 * Enlarge the window again at the remote side,
2415 * just in case it ever runs down and they fail
2416 * to send us any more data.
2418 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
2419 ssh2_pkt_adduint32(mainchan
->remoteid
);
2420 ssh2_pkt_adduint32(length
);
2423 } else if (pktin
.type
== SSH2_MSG_DISCONNECT
) {
2424 ssh_state
= SSH_STATE_CLOSED
;
2425 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
);
2442 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
2443 ssh2_pkt_addstring("All open channels closed");
2444 ssh2_pkt_addstring("en"); /* language tag */
2446 ssh_state
= SSH_STATE_CLOSED
;
2449 continue; /* remote sends close; ignore (FIXME) */
2450 } else if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
2451 /* FIXME: be able to handle other channels here */
2452 if (ssh2_pkt_getuint32() != mainchan
->localid
)
2453 continue; /* wrong channel */
2454 mainchan
->u
.v2
.remwindow
+= ssh2_pkt_getuint32();
2457 bombout(("Strange packet received: type %d", pktin
.type
));
2462 * We have spare data. Add it to the channel buffer.
2464 if (mainchan
->u
.v2
.outbufsize
<
2465 mainchan
->u
.v2
.outbuflen
+ inlen
) {
2466 mainchan
->u
.v2
.outbufsize
=
2467 mainchan
->u
.v2
.outbuflen
+ inlen
+ 1024;
2468 mainchan
->u
.v2
.outbuffer
= srealloc(mainchan
->u
.v2
.outbuffer
,
2469 mainchan
->u
.v2
.outbufsize
);
2471 memcpy(mainchan
->u
.v2
.outbuffer
+ mainchan
->u
.v2
.outbuflen
,
2473 mainchan
->u
.v2
.outbuflen
+= inlen
;
2478 * Try to send data on the channel if we can. (FIXME:
2479 * on _all_ channels.)
2481 while (mainchan
->u
.v2
.remwindow
> 0 &&
2482 mainchan
->u
.v2
.outbuflen
> 0) {
2483 unsigned len
= mainchan
->u
.v2
.remwindow
;
2484 if (len
> mainchan
->u
.v2
.outbuflen
)
2485 len
= mainchan
->u
.v2
.outbuflen
;
2486 if (len
> mainchan
->u
.v2
.remmaxpkt
)
2487 len
= mainchan
->u
.v2
.remmaxpkt
;
2488 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA
);
2489 ssh2_pkt_adduint32(mainchan
->remoteid
);
2490 ssh2_pkt_addstring_start();
2491 ssh2_pkt_addstring_data(mainchan
->u
.v2
.outbuffer
, len
);
2493 mainchan
->u
.v2
.outbuflen
-= len
;
2494 memmove(mainchan
->u
.v2
.outbuffer
, mainchan
->u
.v2
.outbuffer
+len
,
2495 mainchan
->u
.v2
.outbuflen
);
2496 mainchan
->u
.v2
.remwindow
-= len
;
2505 * Handle the top-level SSH2 protocol.
2507 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
)
2509 if (do_ssh2_transport(in
, inlen
, ispkt
) == 0)
2511 do_ssh2_authconn(in
, inlen
, ispkt
);
2515 * Called to set up the connection.
2517 * Returns an error message, or NULL on success.
2519 static char *ssh_init (char *host
, int port
, char **realhost
) {
2523 if(crypto_startup() == 0)
2524 return "Microsoft high encryption pack not installed!";
2529 p
= connect_to_host(host
, port
, realhost
);
2537 * Called to send data down the Telnet connection.
2539 static void ssh_send (char *buf
, int len
) {
2543 ssh_protocol(buf
, len
, 0);
2547 * Called to set the size of the window from SSH's POV.
2549 static void ssh_size(void) {
2550 switch (ssh_state
) {
2551 case SSH_STATE_BEFORE_SIZE
:
2552 case SSH_STATE_CLOSED
:
2553 break; /* do nothing */
2554 case SSH_STATE_INTERMED
:
2555 size_needed
= TRUE
; /* buffer for later */
2557 case SSH_STATE_SESSION
:
2559 if (ssh_version
== 1) {
2560 send_packet(SSH1_CMSG_WINDOW_SIZE
,
2561 PKT_INT
, rows
, PKT_INT
, cols
,
2562 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
2564 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
2565 ssh2_pkt_adduint32(mainchan
->remoteid
);
2566 ssh2_pkt_addstring("window-change");
2567 ssh2_pkt_addbool(0);
2568 ssh2_pkt_adduint32(cols
);
2569 ssh2_pkt_adduint32(rows
);
2570 ssh2_pkt_adduint32(0);
2571 ssh2_pkt_adduint32(0);
2579 * Send Telnet special codes. TS_EOF is useful for `plink', so you
2580 * can send an EOF and collect resulting output (e.g. `plink
2583 static void ssh_special (Telnet_Special code
) {
2584 if (code
== TS_EOF
) {
2585 if (ssh_version
== 1) {
2586 send_packet(SSH1_CMSG_EOF
, PKT_END
);
2588 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF
);
2589 ssh2_pkt_adduint32(mainchan
->remoteid
);
2592 logevent("Sent EOF message");
2593 } else if (code
== TS_PING
) {
2594 if (ssh_version
== 1) {
2595 send_packet(SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
2597 ssh2_pkt_init(SSH2_MSG_IGNORE
);
2598 ssh2_pkt_addstring_start();
2606 static Socket
ssh_socket(void) { return s
; }
2608 static int ssh_sendok(void) { return ssh_send_ok
; }
2610 Backend ssh_backend
= {