18 #define logevent(s) { logevent(s); \
19 if (!(flags & FLAG_CONNECTION) && (flags & FLAG_VERBOSE)) \
20 fprintf(stderr, "%s\n", s); }
22 #define SSH1_MSG_DISCONNECT 1
23 #define SSH1_SMSG_PUBLIC_KEY 2
24 #define SSH1_CMSG_SESSION_KEY 3
25 #define SSH1_CMSG_USER 4
26 #define SSH1_CMSG_AUTH_RSA 6
27 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7
28 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8
29 #define SSH1_CMSG_AUTH_PASSWORD 9
30 #define SSH1_CMSG_REQUEST_PTY 10
31 #define SSH1_CMSG_WINDOW_SIZE 11
32 #define SSH1_CMSG_EXEC_SHELL 12
33 #define SSH1_CMSG_EXEC_CMD 13
34 #define SSH1_SMSG_SUCCESS 14
35 #define SSH1_SMSG_FAILURE 15
36 #define SSH1_CMSG_STDIN_DATA 16
37 #define SSH1_SMSG_STDOUT_DATA 17
38 #define SSH1_SMSG_STDERR_DATA 18
39 #define SSH1_CMSG_EOF 19
40 #define SSH1_SMSG_EXIT_STATUS 20
41 #define SSH1_CMSG_EXIT_CONFIRMATION 33
42 #define SSH1_MSG_IGNORE 32
43 #define SSH1_MSG_DEBUG 36
44 #define SSH1_CMSG_AUTH_TIS 39
45 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40
46 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41
48 #define SSH1_AUTH_TIS 5
50 #define SSH2_MSG_DISCONNECT 1
51 #define SSH2_MSG_IGNORE 2
52 #define SSH2_MSG_UNIMPLEMENTED 3
53 #define SSH2_MSG_DEBUG 4
54 #define SSH2_MSG_SERVICE_REQUEST 5
55 #define SSH2_MSG_SERVICE_ACCEPT 6
56 #define SSH2_MSG_KEXINIT 20
57 #define SSH2_MSG_NEWKEYS 21
58 #define SSH2_MSG_KEXDH_INIT 30
59 #define SSH2_MSG_KEXDH_REPLY 31
60 #define SSH2_MSG_USERAUTH_REQUEST 50
61 #define SSH2_MSG_USERAUTH_FAILURE 51
62 #define SSH2_MSG_USERAUTH_SUCCESS 52
63 #define SSH2_MSG_USERAUTH_BANNER 53
64 #define SSH2_MSG_USERAUTH_PK_OK 60
65 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60
66 #define SSH2_MSG_GLOBAL_REQUEST 80
67 #define SSH2_MSG_REQUEST_SUCCESS 81
68 #define SSH2_MSG_REQUEST_FAILURE 82
69 #define SSH2_MSG_CHANNEL_OPEN 90
70 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91
71 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92
72 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93
73 #define SSH2_MSG_CHANNEL_DATA 94
74 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95
75 #define SSH2_MSG_CHANNEL_EOF 96
76 #define SSH2_MSG_CHANNEL_CLOSE 97
77 #define SSH2_MSG_CHANNEL_REQUEST 98
78 #define SSH2_MSG_CHANNEL_SUCCESS 99
79 #define SSH2_MSG_CHANNEL_FAILURE 100
81 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1
82 #define SSH2_OPEN_CONNECT_FAILED 2
83 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3
84 #define SSH2_OPEN_RESOURCE_SHORTAGE 4
85 #define SSH2_EXTENDED_DATA_STDERR 1
87 #define GET_32BIT(cp) \
88 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
89 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
90 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
91 ((unsigned long)(unsigned char)(cp)[3]))
93 #define PUT_32BIT(cp, value) { \
94 (cp)[0] = (unsigned char)((value) >> 24); \
95 (cp)[1] = (unsigned char)((value) >> 16); \
96 (cp)[2] = (unsigned char)((value) >> 8); \
97 (cp)[3] = (unsigned char)(value); }
99 enum { PKT_END
, PKT_INT
, PKT_CHAR
, PKT_DATA
, PKT_STR
, PKT_BIGNUM
};
101 /* Coroutine mechanics for the sillier bits of the code */
102 #define crBegin1 static int crLine = 0;
103 #define crBegin2 switch(crLine) { case 0:;
104 #define crBegin crBegin1; crBegin2;
105 #define crFinish(z) } crLine = 0; return (z)
106 #define crFinishV } crLine = 0; return
107 #define crReturn(z) \
109 crLine=__LINE__; return (z); case __LINE__:;\
113 crLine=__LINE__; return; case __LINE__:;\
115 #define crStop(z) do{ crLine = 0; return (z); }while(0)
116 #define crStopV do{ crLine = 0; return; }while(0)
117 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
118 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
120 extern struct ssh_cipher ssh_3des
;
121 extern struct ssh_cipher ssh_3des_ssh2
;
122 extern struct ssh_cipher ssh_des
;
123 extern struct ssh_cipher ssh_blowfish
;
125 /* for ssh 2; we miss out single-DES because it isn't supported */
126 struct ssh_cipher
*ciphers
[] = { &ssh_3des_ssh2
, &ssh_blowfish
};
128 extern struct ssh_kex ssh_diffiehellman
;
129 struct ssh_kex
*kex_algs
[] = { &ssh_diffiehellman
};
131 extern struct ssh_hostkey ssh_dss
;
132 struct ssh_hostkey
*hostkey_algs
[] = { &ssh_dss
};
134 extern struct ssh_mac ssh_sha1
;
138 static void nullmac_key(unsigned char *key
) { }
139 static void nullmac_generate(unsigned char *blk
, int len
, unsigned long seq
) { }
140 static int nullmac_verify(unsigned char *blk
, int len
, unsigned long seq
) { return 1; }
141 struct ssh_mac ssh_mac_none
= {
142 nullmac_key
, nullmac_key
, nullmac_generate
, nullmac_verify
, "none", 0
144 struct ssh_mac
*macs
[] = { &ssh_sha1
, &ssh_mac_none
};
146 struct ssh_compress ssh_comp_none
= {
149 struct ssh_compress
*compressions
[] = { &ssh_comp_none
};
151 static SOCKET s
= INVALID_SOCKET
;
153 static unsigned char session_key
[32];
154 static struct ssh_cipher
*cipher
= NULL
;
155 static struct ssh_cipher
*cscipher
= NULL
;
156 static struct ssh_cipher
*sccipher
= NULL
;
157 static struct ssh_mac
*csmac
= NULL
;
158 static struct ssh_mac
*scmac
= NULL
;
159 static struct ssh_compress
*cscomp
= NULL
;
160 static struct ssh_compress
*sccomp
= NULL
;
161 static struct ssh_kex
*kex
= NULL
;
162 static struct ssh_hostkey
*hostkey
= NULL
;
163 int (*ssh_get_password
)(const char *prompt
, char *str
, int maxlen
) = NULL
;
165 static char *savedhost
;
166 static int ssh_send_ok
;
169 SSH_STATE_BEFORE_SIZE
,
173 } ssh_state
= SSH_STATE_BEFORE_SIZE
;
175 static int size_needed
= FALSE
;
177 static void s_write (char *buf
, int len
) {
179 int i
= send (s
, buf
, len
, 0);
182 fatalbox("Lost connection while sending");
188 static int s_read (char *buf
, int len
) {
191 int i
= recv (s
, buf
, len
, 0);
194 len
-= i
, buf
+= i
, ret
+= i
;
201 static void c_write (char *buf
, int len
) {
202 if (!(flags
& FLAG_CONNECTION
)) {
204 for (i
= 0; i
< len
; i
++)
206 fputc(buf
[i
], stderr
);
222 static struct Packet pktin
= { 0, 0, NULL
, NULL
, 0 };
223 static struct Packet pktout
= { 0, 0, NULL
, NULL
, 0 };
225 static int ssh_version
;
226 static void (*ssh_protocol
)(unsigned char *in
, int inlen
, int ispkt
);
227 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
);
228 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
);
229 static void ssh_size(void);
231 static int (*s_rdpkt
)(unsigned char **data
, int *datalen
);
234 * Collect incoming data in the incoming packet buffer.
235 * Decipher and verify the packet when it is completely read.
236 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
237 * Update the *data and *datalen variables.
238 * Return the additional nr of bytes needed, or 0 when
239 * a complete packet is available.
241 static int ssh1_rdpkt(unsigned char **data
, int *datalen
)
243 static long len
, pad
, biglen
, to_read
;
244 static unsigned long realcrc
, gotcrc
;
245 static unsigned char *p
;
255 for (i
= len
= 0; i
< 4; i
++) {
256 while ((*datalen
) == 0)
258 len
= (len
<< 8) + **data
;
259 (*data
)++, (*datalen
)--;
263 if (len
== 0x52656d6f) { /* "Remo"te server has closed ... */
264 len
= 0x300; /* big enough to carry to end */
270 pktin
.length
= len
- 5;
272 if (pktin
.maxlen
< biglen
) {
273 pktin
.maxlen
= biglen
;
274 pktin
.data
= (pktin
.data
== NULL ?
malloc(biglen
+APIEXTRA
) :
275 realloc(pktin
.data
, biglen
+APIEXTRA
));
277 fatalbox("Out of memory");
282 while (to_read
> 0) {
285 while ((*datalen
) == 0)
287 if (chunk
> (*datalen
))
289 memcpy(p
, *data
, chunk
);
297 cipher
->decrypt(pktin
.data
, biglen
);
299 pktin
.type
= pktin
.data
[pad
];
300 pktin
.body
= pktin
.data
+ pad
+ 1;
302 realcrc
= crc32(pktin
.data
, biglen
-4);
303 gotcrc
= GET_32BIT(pktin
.data
+biglen
-4);
304 if (gotcrc
!= realcrc
) {
305 fatalbox("Incorrect CRC received on packet");
308 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
309 pktin
.type
== SSH1_SMSG_STDERR_DATA
||
310 pktin
.type
== SSH1_MSG_DEBUG
||
311 pktin
.type
== SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
312 long strlen
= GET_32BIT(pktin
.body
);
313 if (strlen
+ 4 != pktin
.length
)
314 fatalbox("Received data packet with bogus string length");
317 if (pktin
.type
== SSH1_MSG_DEBUG
) {
318 /* log debug message */
320 int strlen
= GET_32BIT(pktin
.body
);
321 strcpy(buf
, "Remote: ");
322 if (strlen
> 70) strlen
= 70;
323 memcpy(buf
+8, pktin
.body
+4, strlen
);
324 buf
[8+strlen
] = '\0';
327 } else if (pktin
.type
== SSH1_MSG_IGNORE
) {
335 static int ssh2_rdpkt(unsigned char **data
, int *datalen
)
337 static long len
, pad
, payload
, packetlen
, maclen
;
339 static int cipherblk
;
340 static unsigned long incoming_sequence
= 0;
350 cipherblk
= cipher
->blksize
;
356 if (pktin
.maxlen
< cipherblk
) {
357 pktin
.maxlen
= cipherblk
;
358 pktin
.data
= (pktin
.data
== NULL ?
malloc(cipherblk
+APIEXTRA
) :
359 realloc(pktin
.data
, cipherblk
+APIEXTRA
));
361 fatalbox("Out of memory");
365 * Acquire and decrypt the first block of the packet. This will
366 * contain the length and padding details.
368 for (i
= len
= 0; i
< cipherblk
; i
++) {
369 while ((*datalen
) == 0)
370 crReturn(cipherblk
-i
);
371 pktin
.data
[i
] = *(*data
)++;
375 if (!memcmp(pktin
.data
, "Remo", 4)) {/* "Remo"te server has closed ... */
380 sccipher
->decrypt(pktin
.data
, cipherblk
);
383 * Now get the length and padding figures.
385 len
= GET_32BIT(pktin
.data
);
389 * This enables us to deduce the payload length.
391 payload
= len
- pad
- 1;
393 pktin
.length
= payload
+ 5;
396 * So now we can work out the total packet length.
399 maclen
= scmac ? scmac
->len
: 0;
402 * Adjust memory allocation if packet is too big.
404 if (pktin
.maxlen
< packetlen
) {
405 pktin
.maxlen
= packetlen
;
406 pktin
.data
= (pktin
.data
== NULL ?
malloc(packetlen
+APIEXTRA
) :
407 realloc(pktin
.data
, packetlen
+APIEXTRA
));
409 fatalbox("Out of memory");
413 * Read and decrypt the remainder of the packet.
415 for (i
= cipherblk
; i
< packetlen
+ maclen
; i
++) {
416 while ((*datalen
) == 0)
417 crReturn(packetlen
+ maclen
- i
);
418 pktin
.data
[i
] = *(*data
)++;
421 /* Decrypt everything _except_ the MAC. */
423 sccipher
->decrypt(pktin
.data
+ cipherblk
, packetlen
- cipherblk
);
426 debug(("Got packet len=%d pad=%d\r\n", len
, pad
));
427 for (i
= 0; i
< packetlen
; i
++)
428 debug((" %02x", (unsigned char)pktin
.data
[i
]));
435 if (scmac
&& !scmac
->verify(pktin
.data
, len
+4, incoming_sequence
))
436 fatalbox("Incorrect MAC received on packet");
437 incoming_sequence
++; /* whether or not we MACed */
440 pktin
.type
= pktin
.data
[5];
442 if (pktin
.type
== SSH2_MSG_IGNORE
|| pktin
.type
== SSH2_MSG_DEBUG
)
443 goto next_packet
; /* FIXME: print DEBUG message */
448 static void ssh_gotdata(unsigned char *data
, int datalen
)
450 while (datalen
> 0) {
451 if ( s_rdpkt(&data
, &datalen
) == 0 ) {
452 ssh_protocol(NULL
, 0, 1);
453 if (ssh_state
== SSH_STATE_CLOSED
) {
461 static void s_wrpkt_start(int type
, int len
) {
464 len
+= 5; /* type and CRC */
468 pktout
.length
= len
-5;
469 if (pktout
.maxlen
< biglen
) {
470 pktout
.maxlen
= biglen
;
472 /* Allocate enough buffer space for extra block
473 * for MS CryptEncrypt() */
474 pktout
.data
= (pktout
.data
== NULL ?
malloc(biglen
+12) :
475 realloc(pktout
.data
, biglen
+12));
477 pktout
.data
= (pktout
.data
== NULL ?
malloc(biglen
+4) :
478 realloc(pktout
.data
, biglen
+4));
481 fatalbox("Out of memory");
485 pktout
.body
= pktout
.data
+4+pad
+1;
488 static void s_wrpkt(void) {
489 int pad
, len
, biglen
, i
;
492 len
= pktout
.length
+ 5; /* type and CRC */
496 pktout
.body
[-1] = pktout
.type
;
497 for (i
=0; i
<pad
; i
++)
498 pktout
.data
[i
+4] = random_byte();
499 crc
= crc32(pktout
.data
+4, biglen
-4);
500 PUT_32BIT(pktout
.data
+biglen
, crc
);
501 PUT_32BIT(pktout
.data
, len
);
504 cipher
->encrypt(pktout
.data
+4, biglen
);
506 s_write(pktout
.data
, biglen
+4);
510 * Construct a packet with the specified contents and
511 * send it to the server.
513 static void send_packet(int pkttype
, ...)
516 unsigned char *p
, *argp
, argchar
;
517 unsigned long argint
;
518 int pktlen
, argtype
, arglen
;
523 va_start(args
, pkttype
);
524 while ((argtype
= va_arg(args
, int)) != PKT_END
) {
527 (void) va_arg(args
, int);
531 (void) va_arg(args
, char);
535 (void) va_arg(args
, unsigned char *);
536 arglen
= va_arg(args
, int);
540 argp
= va_arg(args
, unsigned char *);
541 arglen
= strlen(argp
);
542 pktlen
+= 4 + arglen
;
545 bn
= va_arg(args
, Bignum
);
547 while ( i
> 0 && (bn
[i
/16+1] >> (i
%16)) == 0 )
549 pktlen
+= 2 + (i
+7)/8;
557 s_wrpkt_start(pkttype
, pktlen
);
560 va_start(args
, pkttype
);
561 while ((argtype
= va_arg(args
, int)) != PKT_END
) {
564 argint
= va_arg(args
, int);
565 PUT_32BIT(p
, argint
);
569 argchar
= va_arg(args
, unsigned char);
574 argp
= va_arg(args
, unsigned char *);
575 arglen
= va_arg(args
, int);
576 memcpy(p
, argp
, arglen
);
580 argp
= va_arg(args
, unsigned char *);
581 arglen
= strlen(argp
);
582 PUT_32BIT(p
, arglen
);
583 memcpy(p
+ 4, argp
, arglen
);
587 bn
= va_arg(args
, Bignum
);
589 while ( i
> 0 && (bn
[i
/16+1] >> (i
%16)) == 0 )
591 *p
++ = (i
>> 8) & 0xFF;
596 *p
++ = bn
[i
/2+1] >> 8;
598 *p
++ = bn
[i
/2+1] & 0xFF;
610 * Connect to specified host and port.
611 * Returns an error message, or NULL on success.
612 * Also places the canonical host name into `realhost'.
614 static char *connect_to_host(char *host
, int port
, char **realhost
)
624 savedhost
= malloc(1+strlen(host
));
626 fatalbox("Out of memory");
627 strcpy(savedhost
, host
);
630 port
= 22; /* default ssh port */
642 if ( (a
= inet_addr(host
)) == (unsigned long) INADDR_NONE
) {
643 if ( (h
= gethostbyname(host
)) == NULL
)
644 switch (WSAGetLastError()) {
645 case WSAENETDOWN
: return "Network is down";
646 case WSAHOST_NOT_FOUND
: case WSANO_DATA
:
647 return "Host does not exist";
648 case WSATRY_AGAIN
: return "Host not found";
649 default: return "gethostbyname: unknown error";
651 memcpy (&a
, h
->h_addr
, sizeof(a
));
652 *realhost
= h
->h_name
;
663 s
= socket(AF_INET
, SOCK_STREAM
, 0);
664 if (s
== INVALID_SOCKET
)
665 switch (WSAGetLastError()) {
666 case WSAENETDOWN
: return "Network is down";
667 case WSAEAFNOSUPPORT
: return "TCP/IP support not present";
668 default: return "socket(): unknown error";
672 * Bind to local address.
674 addr
.sin_family
= AF_INET
;
675 addr
.sin_addr
.s_addr
= htonl(INADDR_ANY
);
676 addr
.sin_port
= htons(0);
677 if (bind (s
, (struct sockaddr
*)&addr
, sizeof(addr
)) == SOCKET_ERROR
)
678 switch (WSAGetLastError()) {
679 case WSAENETDOWN
: return "Network is down";
680 default: return "bind(): unknown error";
684 * Connect to remote address.
686 addr
.sin_addr
.s_addr
= htonl(a
);
687 addr
.sin_port
= htons((short)port
);
688 if (connect (s
, (struct sockaddr
*)&addr
, sizeof(addr
)) == SOCKET_ERROR
)
689 switch (WSAGetLastError()) {
690 case WSAENETDOWN
: return "Network is down";
691 case WSAECONNREFUSED
: return "Connection refused";
692 case WSAENETUNREACH
: return "Network is unreachable";
693 case WSAEHOSTUNREACH
: return "No route to host";
694 default: return "connect(): unknown error";
698 send(s
, "connect ", 8, 0);
699 send(s
, FWhost
, strlen(FWhost
), 0);
702 sprintf(buf
, " %d\n", FWport
);
703 send (s
, buf
, strlen(buf
), 0);
710 static int ssh_versioncmp(char *a
, char *b
) {
712 unsigned long av
, bv
;
714 av
= strtoul(a
, &ae
, 10);
715 bv
= strtoul(b
, &be
, 10);
716 if (av
!= bv
) return (av
< bv ?
-1 : +1);
717 if (*ae
== '.') ae
++;
718 if (*be
== '.') be
++;
719 av
= strtoul(ae
, &ae
, 10);
720 bv
= strtoul(be
, &be
, 10);
721 if (av
!= bv
) return (av
< bv ?
-1 : +1);
727 * Utility routine for putting an SSH-protocol `string' into a SHA
731 void sha_string(SHA_State
*s
, void *str
, int len
) {
732 unsigned char lenblk
[4];
733 PUT_32BIT(lenblk
, len
);
734 SHA_Bytes(s
, lenblk
, 4);
735 SHA_Bytes(s
, str
, len
);
739 * SSH2 packet construction functions.
741 void ssh2_pkt_adddata(void *data
, int len
) {
742 pktout
.length
+= len
;
743 if (pktout
.maxlen
< pktout
.length
) {
744 pktout
.maxlen
= pktout
.length
+ 256;
745 pktout
.data
= (pktout
.data
== NULL ?
malloc(pktout
.maxlen
+APIEXTRA
) :
746 realloc(pktout
.data
, pktout
.maxlen
+APIEXTRA
));
748 fatalbox("Out of memory");
750 memcpy(pktout
.data
+pktout
.length
-len
, data
, len
);
752 void ssh2_pkt_addbyte(unsigned char byte
) {
753 ssh2_pkt_adddata(&byte
, 1);
755 void ssh2_pkt_init(int pkt_type
) {
757 ssh2_pkt_addbyte((unsigned char)pkt_type
);
759 void ssh2_pkt_addbool(unsigned char value
) {
760 ssh2_pkt_adddata(&value
, 1);
762 void ssh2_pkt_adduint32(unsigned long value
) {
765 ssh2_pkt_adddata(x
, 4);
767 void ssh2_pkt_addstring_start(void) {
768 ssh2_pkt_adduint32(0);
769 pktout
.savedpos
= pktout
.length
;
771 void ssh2_pkt_addstring_str(char *data
) {
772 ssh2_pkt_adddata(data
, strlen(data
));
773 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
774 pktout
.length
- pktout
.savedpos
);
776 void ssh2_pkt_addstring_data(char *data
, int len
) {
777 ssh2_pkt_adddata(data
, len
);
778 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
779 pktout
.length
- pktout
.savedpos
);
781 void ssh2_pkt_addstring(char *data
) {
782 ssh2_pkt_addstring_start();
783 ssh2_pkt_addstring_str(data
);
785 char *ssh2_mpint_fmt(Bignum b
, int *len
) {
788 p
= malloc(n
* 2 + 1);
790 fatalbox("out of memory");
792 for (i
= 0; i
< n
; i
++) {
793 p
[i
*2+1] = (b
[n
-i
] >> 8) & 0xFF;
794 p
[i
*2+2] = (b
[n
-i
] ) & 0xFF;
797 while (p
[i
] == 0 && (p
[i
+1] & 0x80) == 0)
799 memmove(p
, p
+i
, n
*2+1-i
);
803 void ssh2_pkt_addmp(Bignum b
) {
806 p
= ssh2_mpint_fmt(b
, &len
);
807 ssh2_pkt_addstring_start();
808 ssh2_pkt_addstring_data(p
, len
);
811 void ssh2_pkt_send(void) {
812 int cipherblk
, maclen
, padding
, i
;
813 static unsigned long outgoing_sequence
= 0;
816 * Add padding. At least four bytes, and must also bring total
817 * length (minus MAC) up to a multiple of the block size.
819 cipherblk
= cipher ? cipher
->blksize
: 8; /* block size */
820 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
822 padding
+= (cipherblk
- (pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
823 pktout
.data
[4] = padding
;
824 for (i
= 0; i
< padding
; i
++)
825 pktout
.data
[pktout
.length
+ i
] = random_byte();
826 PUT_32BIT(pktout
.data
, pktout
.length
+ padding
- 4);
828 csmac
->generate(pktout
.data
, pktout
.length
+ padding
,
830 outgoing_sequence
++; /* whether or not we MACed */
833 debug(("Sending packet len=%d\r\n", pktout
.length
+padding
));
834 for (i
= 0; i
< pktout
.length
+padding
; i
++)
835 debug((" %02x", (unsigned char)pktout
.data
[i
]));
840 cscipher
->encrypt(pktout
.data
, pktout
.length
+ padding
);
841 maclen
= csmac ? csmac
->len
: 0;
843 s_write(pktout
.data
, pktout
.length
+ padding
+ maclen
);
847 void bndebug(char *string
, Bignum b
) {
850 p
= ssh2_mpint_fmt(b
, &len
);
851 debug(("%s", string
));
852 for (i
= 0; i
< len
; i
++)
853 debug((" %02x", p
[i
]));
859 void sha_mpint(SHA_State
*s
, Bignum b
) {
862 p
= ssh2_mpint_fmt(b
, &len
);
863 sha_string(s
, p
, len
);
868 * SSH2 packet decode functions.
870 unsigned long ssh2_pkt_getuint32(void) {
872 if (pktin
.length
- pktin
.savedpos
< 4)
873 return 0; /* arrgh, no way to decline (FIXME?) */
874 value
= GET_32BIT(pktin
.data
+pktin
.savedpos
);
878 void ssh2_pkt_getstring(char **p
, int *length
) {
880 if (pktin
.length
- pktin
.savedpos
< 4)
882 *length
= GET_32BIT(pktin
.data
+pktin
.savedpos
);
884 if (pktin
.length
- pktin
.savedpos
< *length
)
886 *p
= pktin
.data
+pktin
.savedpos
;
887 pktin
.savedpos
+= *length
;
889 Bignum
ssh2_pkt_getmp(void) {
894 ssh2_pkt_getstring(&p
, &length
);
898 fatalbox("internal error: Can't handle negative mpints");
899 b
= newbn((length
+1)/2);
900 for (i
= 0; i
< length
; i
++) {
903 b
[j
/2+1] |= ((unsigned char)p
[i
]) << 8;
905 b
[j
/2+1] |= ((unsigned char)p
[i
]);
910 static int do_ssh_init(void) {
914 char vlog
[sizeof(vstring
)+20];
919 while (s_read(&c
, 1) == 1) {
920 if (c
== 'S' && i
< 2) i
++;
921 else if (c
== 'S' && i
== 2) i
= 2;
922 else if (c
== 'H' && i
== 2) break;
926 if (s_read(&c
,1) != 1 || c
!= 'S') return 0;
927 if (s_read(&c
,1) != 1 || c
!= 'S') return 0;
928 if (s_read(&c
,1) != 1 || c
!= 'H') return 0;
930 strcpy(vstring
, "SSH-");
932 if (s_read(&c
,1) != 1 || c
!= '-') return 0;
935 if (s_read(&c
,1) != 1)
937 if (vsp
< vstring
+sizeof(vstring
)-1)
943 } else if (i
< sizeof(version
)-1)
951 sprintf(vlog
, "Server version: %s", vstring
);
952 vlog
[strcspn(vlog
, "\r\n")] = '\0';
955 if (ssh_versioncmp(version
, "2.0" /* FIXME: "1.99" */ ) >= 0) {
957 * This is a v2 server. Begin v2 protocol.
959 char *verstring
= "SSH-2.0-PuTTY";
962 * Hash our version string and their version string.
964 sha_string(&exhash
, verstring
, strlen(verstring
));
965 sha_string(&exhash
, vstring
, strcspn(vstring
, "\r\n"));
966 sprintf(vstring
, "%s\n", verstring
);
967 sprintf(vlog
, "We claim version: %s", verstring
);
969 logevent("Using SSH protocol version 2");
970 s_write(vstring
, strlen(vstring
));
971 ssh_protocol
= ssh2_protocol
;
973 s_rdpkt
= ssh2_rdpkt
;
976 * This is a v1 server. Begin v1 protocol.
978 sprintf(vstring
, "SSH-%s-PuTTY\n",
979 (ssh_versioncmp(version
, "1.5") <= 0 ? version
: "1.5"));
980 sprintf(vlog
, "We claim version: %s", vstring
);
981 vlog
[strcspn(vlog
, "\r\n")] = '\0';
983 logevent("Using SSH protocol version 1");
984 s_write(vstring
, strlen(vstring
));
985 ssh_protocol
= ssh1_protocol
;
987 s_rdpkt
= ssh1_rdpkt
;
994 * Handle the key exchange and user authentication phases.
996 static int do_ssh1_login(unsigned char *in
, int inlen
, int ispkt
)
999 unsigned char *rsabuf
, *keystr1
, *keystr2
;
1000 unsigned char cookie
[8];
1001 struct RSAKey servkey
, hostkey
;
1002 struct MD5Context md5c
;
1003 static unsigned long supported_ciphers_mask
, supported_auths_mask
;
1004 static int tried_publickey
;
1005 static unsigned char session_id
[16];
1010 if (!ispkt
) crWaitUntil(ispkt
);
1012 if (pktin
.type
!= SSH1_SMSG_PUBLIC_KEY
)
1013 fatalbox("Public key packet not received");
1015 logevent("Received public keys");
1017 memcpy(cookie
, pktin
.body
, 8);
1019 i
= makekey(pktin
.body
+8, &servkey
, &keystr1
, 0);
1020 j
= makekey(pktin
.body
+8+i
, &hostkey
, &keystr2
, 0);
1023 * Hash the host key and print the hash in the log box. Just as
1024 * a last resort in case the registry's host key checking is
1025 * compromised, we'll allow the user some ability to verify
1029 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
1030 MD5Final(session_id
, &md5c
);
1034 logevent("Host key MD5 is:");
1035 strcpy(logmsg
, " ");
1036 for (i
= 0; i
< 16; i
++)
1037 sprintf(logmsg
+strlen(logmsg
), "%02x", session_id
[i
]);
1041 supported_ciphers_mask
= GET_32BIT(pktin
.body
+12+i
+j
);
1042 supported_auths_mask
= GET_32BIT(pktin
.body
+16+i
+j
);
1045 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
1046 MD5Update(&md5c
, keystr1
, servkey
.bytes
);
1047 MD5Update(&md5c
, pktin
.body
, 8);
1048 MD5Final(session_id
, &md5c
);
1050 for (i
=0; i
<32; i
++)
1051 session_key
[i
] = random_byte();
1053 len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
1055 rsabuf
= malloc(len
);
1057 fatalbox("Out of memory");
1060 * Verify the host key.
1064 * First format the key into a string.
1066 int len
= rsastr_len(&hostkey
);
1067 char *keystr
= malloc(len
);
1069 fatalbox("Out of memory");
1070 rsastr_fmt(keystr
, &hostkey
);
1071 verify_ssh_host_key(savedhost
, keystr
);
1075 for (i
=0; i
<32; i
++) {
1076 rsabuf
[i
] = session_key
[i
];
1078 rsabuf
[i
] ^= session_id
[i
];
1081 if (hostkey
.bytes
> servkey
.bytes
) {
1082 rsaencrypt(rsabuf
, 32, &servkey
);
1083 rsaencrypt(rsabuf
, servkey
.bytes
, &hostkey
);
1085 rsaencrypt(rsabuf
, 32, &hostkey
);
1086 rsaencrypt(rsabuf
, hostkey
.bytes
, &servkey
);
1089 logevent("Encrypted session key");
1091 cipher_type
= cfg
.cipher
== CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH
:
1092 cfg
.cipher
== CIPHER_DES ? SSH_CIPHER_DES
:
1094 if ((supported_ciphers_mask
& (1 << cipher_type
)) == 0) {
1095 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1096 cipher_type
= SSH_CIPHER_3DES
;
1098 switch (cipher_type
) {
1099 case SSH_CIPHER_3DES
: logevent("Using 3DES encryption"); break;
1100 case SSH_CIPHER_DES
: logevent("Using single-DES encryption"); break;
1101 case SSH_CIPHER_BLOWFISH
: logevent("Using Blowfish encryption"); break;
1104 send_packet(SSH1_CMSG_SESSION_KEY
,
1105 PKT_CHAR
, cipher_type
,
1106 PKT_DATA
, cookie
, 8,
1107 PKT_CHAR
, (len
*8) >> 8, PKT_CHAR
, (len
*8) & 0xFF,
1108 PKT_DATA
, rsabuf
, len
,
1112 logevent("Trying to enable encryption...");
1116 cipher
= cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish
:
1117 cipher_type
== SSH_CIPHER_DES ?
&ssh_des
:
1119 cipher
->sesskey(session_key
);
1123 if (pktin
.type
!= SSH1_SMSG_SUCCESS
)
1124 fatalbox("Encryption not successfully enabled");
1126 logevent("Successfully started encryption");
1130 static char username
[100];
1133 if (!(flags
& FLAG_CONNECTION
) && !*cfg
.username
) {
1134 c_write("login as: ", 10);
1136 crWaitUntil(!ispkt
);
1137 while (inlen
--) switch (c
= *in
++) {
1144 c_write("\b \b", 3);
1150 c_write("\b \b", 3);
1159 if (((c
>= ' ' && c
<= '~') ||
1160 ((unsigned char)c
>= 160)) && pos
< 40) {
1161 username
[pos
++] = c
;
1168 username
[strcspn(username
, "\n\r")] = '\0';
1171 strncpy(username
, cfg
.username
, 99);
1172 username
[99] = '\0';
1173 if (flags
& FLAG_VERBOSE
) {
1174 sprintf(stuff
, "Sent username \"%s\".\r\n", username
);
1175 c_write(stuff
, strlen(stuff
));
1179 send_packet(SSH1_CMSG_USER
, PKT_STR
, username
, PKT_END
);
1181 char userlog
[20+sizeof(username
)];
1182 sprintf(userlog
, "Sent username \"%s\"", username
);
1189 tried_publickey
= 0;
1191 while (pktin
.type
== SSH1_SMSG_FAILURE
) {
1192 static char password
[100];
1195 static int pwpkt_type
;
1197 * Show password prompt, having first obtained it via a TIS
1198 * exchange if we're doing TIS authentication.
1200 pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
1201 if (*cfg
.keyfile
&& !tried_publickey
)
1202 pwpkt_type
= SSH1_CMSG_AUTH_RSA
;
1204 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
&& !FLAG_WINDOWED
) {
1206 sprintf(prompt
, "%s@%s's password: ", cfg
.username
, savedhost
);
1207 if (!ssh_get_password(prompt
, password
, sizeof(password
))) {
1209 * get_password failed to get a password (for
1210 * example because one was supplied on the command
1211 * line which has already failed to work).
1214 logevent("No more passwords to try");
1215 ssh_state
= SSH_STATE_CLOSED
;
1220 if (pktin
.type
== SSH1_SMSG_FAILURE
&&
1222 (supported_auths_mask
& (1<<SSH1_AUTH_TIS
))) {
1223 pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
1224 logevent("Requested TIS authentication");
1225 send_packet(SSH1_CMSG_AUTH_TIS
, PKT_END
);
1227 if (pktin
.type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
1228 logevent("TIS authentication declined");
1229 c_write("TIS authentication refused.\r\n", 29);
1231 int challengelen
= ((pktin
.body
[0] << 24) |
1232 (pktin
.body
[1] << 16) |
1233 (pktin
.body
[2] << 8) |
1235 logevent("Received TIS challenge");
1236 c_write(pktin
.body
+4, challengelen
);
1239 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
)
1240 c_write("password: ", 10);
1241 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
1242 if (flags
& FLAG_VERBOSE
)
1243 c_write("Trying public key authentication.\r\n", 35);
1244 if (!rsakey_encrypted(cfg
.keyfile
)) {
1245 if (flags
& FLAG_VERBOSE
)
1246 c_write("No passphrase required.\r\n", 25);
1249 c_write("passphrase: ", 12);
1254 crWaitUntil(!ispkt
);
1255 while (inlen
--) switch (c
= *in
++) {
1272 if (((c
>= ' ' && c
<= '~') ||
1273 ((unsigned char)c
>= 160)) && pos
< sizeof(password
))
1274 password
[pos
++] = c
;
1283 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
1285 * Try public key authentication with the specified
1288 static struct RSAKey pubkey
;
1289 static Bignum challenge
, response
;
1291 static unsigned char buffer
[32];
1293 tried_publickey
= 1;
1294 i
= loadrsakey(cfg
.keyfile
, &pubkey
, password
);
1296 c_write("Couldn't load public key from ", 30);
1297 c_write(cfg
.keyfile
, strlen(cfg
.keyfile
));
1298 c_write(".\r\n", 3);
1299 continue; /* go and try password */
1302 c_write("Wrong passphrase.\r\n", 19);
1303 tried_publickey
= 0;
1304 continue; /* try again */
1308 * Send a public key attempt.
1310 send_packet(SSH1_CMSG_AUTH_RSA
,
1311 PKT_BIGNUM
, pubkey
.modulus
, PKT_END
);
1314 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1315 if (flags
& FLAG_VERBOSE
)
1316 c_write("Server refused our public key.\r\n", 32);
1317 continue; /* go and try password */
1319 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
)
1320 fatalbox("Bizarre response to offer of public key");
1321 ssh1_read_bignum(pktin
.body
, &challenge
);
1322 response
= rsadecrypt(challenge
, &pubkey
);
1323 freebn(pubkey
.private_exponent
); /* burn the evidence */
1325 for (i
= 0; i
< 32; i
+= 2) {
1326 buffer
[i
] = response
[16-i
/2] >> 8;
1327 buffer
[i
+1] = response
[16-i
/2] & 0xFF;
1331 MD5Update(&md5c
, buffer
, 32);
1332 MD5Update(&md5c
, session_id
, 16);
1333 MD5Final(buffer
, &md5c
);
1335 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
1336 PKT_DATA
, buffer
, 16, PKT_END
);
1339 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1340 if (flags
& FLAG_VERBOSE
)
1341 c_write("Failed to authenticate with our public key.\r\n",
1343 continue; /* go and try password */
1344 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1345 fatalbox("Bizarre response to RSA authentication response");
1348 break; /* we're through! */
1350 send_packet(pwpkt_type
, PKT_STR
, password
, PKT_END
);
1352 logevent("Sent password");
1353 memset(password
, 0, strlen(password
));
1355 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1356 if (flags
& FLAG_VERBOSE
)
1357 c_write("Access denied\r\n", 15);
1358 logevent("Authentication refused");
1359 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
1360 logevent("Received disconnect request");
1361 ssh_state
= SSH_STATE_CLOSED
;
1363 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1364 fatalbox("Strange packet received, type %d", pktin
.type
);
1368 logevent("Authentication successful");
1373 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
) {
1378 while (!do_ssh1_login(in
, inlen
, ispkt
)) {
1381 if (ssh_state
== SSH_STATE_CLOSED
)
1385 send_packet(SSH1_CMSG_REQUEST_PTY
,
1386 PKT_STR
, cfg
.termtype
,
1387 PKT_INT
, rows
, PKT_INT
, cols
,
1388 PKT_INT
, 0, PKT_INT
, 0,
1391 ssh_state
= SSH_STATE_INTERMED
;
1392 do { crReturnV
; } while (!ispkt
);
1393 if (pktin
.type
!= SSH1_SMSG_SUCCESS
&& pktin
.type
!= SSH1_SMSG_FAILURE
) {
1394 fatalbox("Protocol confusion");
1395 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1396 c_write("Server refused to allocate pty\r\n", 32);
1398 logevent("Allocated pty");
1401 if (*cfg
.remote_cmd
)
1402 send_packet(SSH1_CMSG_EXEC_CMD
, PKT_STR
, cfg
.remote_cmd
, PKT_END
);
1404 send_packet(SSH1_CMSG_EXEC_SHELL
, PKT_END
);
1405 logevent("Started session");
1407 ssh_state
= SSH_STATE_SESSION
;
1415 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
1416 pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
1417 long len
= GET_32BIT(pktin
.body
);
1418 c_write(pktin
.body
+4, len
);
1419 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
1420 ssh_state
= SSH_STATE_CLOSED
;
1421 logevent("Received disconnect request");
1422 } else if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
1423 /* may be from EXEC_SHELL on some servers */
1424 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1425 /* may be from EXEC_SHELL on some servers
1426 * if no pty is available or in other odd cases. Ignore */
1427 } else if (pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
1428 send_packet(SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
1430 fatalbox("Strange packet received: type %d", pktin
.type
);
1433 send_packet(SSH1_CMSG_STDIN_DATA
,
1434 PKT_INT
, inlen
, PKT_DATA
, in
, inlen
, PKT_END
);
1442 * Utility routine for decoding comma-separated strings in KEXINIT.
1444 int in_commasep_string(char *needle
, char *haystack
, int haylen
) {
1445 int needlen
= strlen(needle
);
1448 * Is it at the start of the string?
1450 if (haylen
>= needlen
&& /* haystack is long enough */
1451 !memcmp(needle
, haystack
, needlen
) && /* initial match */
1452 (haylen
== needlen
|| haystack
[needlen
] == ',')
1453 /* either , or EOS follows */
1457 * If not, search for the next comma and resume after that.
1458 * If no comma found, terminate.
1460 while (haylen
> 0 && *haystack
!= ',')
1461 haylen
--, haystack
++;
1464 haylen
--, haystack
++; /* skip over comma itself */
1469 * SSH2 key creation method.
1471 void ssh2_mkkey(Bignum K
, char *H
, char chr
, char *keyspace
) {
1473 /* First 20 bytes. */
1476 SHA_Bytes(&s
, H
, 20);
1477 SHA_Bytes(&s
, &chr
, 1);
1478 SHA_Bytes(&s
, H
, 20);
1479 SHA_Final(&s
, keyspace
);
1480 /* Next 20 bytes. */
1483 SHA_Bytes(&s
, H
, 20);
1484 SHA_Bytes(&s
, keyspace
, 20);
1485 SHA_Final(&s
, keyspace
+20);
1489 * Handle the SSH2 transport layer.
1491 static int do_ssh2_transport(unsigned char *in
, int inlen
, int ispkt
)
1495 static Bignum e
, f
, K
;
1496 static struct ssh_cipher
*cscipher_tobe
= NULL
;
1497 static struct ssh_cipher
*sccipher_tobe
= NULL
;
1498 static struct ssh_mac
*csmac_tobe
= NULL
;
1499 static struct ssh_mac
*scmac_tobe
= NULL
;
1500 static struct ssh_compress
*cscomp_tobe
= NULL
;
1501 static struct ssh_compress
*sccomp_tobe
= NULL
;
1502 static char *hostkeydata
, *sigdata
, *keystr
;
1503 static int hostkeylen
, siglen
;
1504 static unsigned char exchange_hash
[20];
1505 static unsigned char keyspace
[40];
1512 * Construct and send our key exchange packet.
1514 ssh2_pkt_init(SSH2_MSG_KEXINIT
);
1515 for (i
= 0; i
< 16; i
++)
1516 ssh2_pkt_addbyte((unsigned char)random_byte());
1517 /* List key exchange algorithms. */
1518 ssh2_pkt_addstring_start();
1519 for (i
= 0; i
< lenof(kex_algs
); i
++) {
1520 ssh2_pkt_addstring_str(kex_algs
[i
]->name
);
1521 if (i
< lenof(kex_algs
)-1)
1522 ssh2_pkt_addstring_str(",");
1524 /* List server host key algorithms. */
1525 ssh2_pkt_addstring_start();
1526 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
1527 ssh2_pkt_addstring_str(hostkey_algs
[i
]->name
);
1528 if (i
< lenof(hostkey_algs
)-1)
1529 ssh2_pkt_addstring_str(",");
1531 /* List client->server encryption algorithms. */
1532 ssh2_pkt_addstring_start();
1533 for (i
= 0; i
< lenof(ciphers
); i
++) {
1534 ssh2_pkt_addstring_str(ciphers
[i
]->name
);
1535 if (i
< lenof(ciphers
)-1)
1536 ssh2_pkt_addstring_str(",");
1538 /* List server->client encryption algorithms. */
1539 ssh2_pkt_addstring_start();
1540 for (i
= 0; i
< lenof(ciphers
); i
++) {
1541 ssh2_pkt_addstring_str(ciphers
[i
]->name
);
1542 if (i
< lenof(ciphers
)-1)
1543 ssh2_pkt_addstring_str(",");
1545 /* List client->server MAC algorithms. */
1546 ssh2_pkt_addstring_start();
1547 for (i
= 0; i
< lenof(macs
); i
++) {
1548 ssh2_pkt_addstring_str(macs
[i
]->name
);
1549 if (i
< lenof(macs
)-1)
1550 ssh2_pkt_addstring_str(",");
1552 /* List server->client MAC algorithms. */
1553 ssh2_pkt_addstring_start();
1554 for (i
= 0; i
< lenof(macs
); i
++) {
1555 ssh2_pkt_addstring_str(macs
[i
]->name
);
1556 if (i
< lenof(macs
)-1)
1557 ssh2_pkt_addstring_str(",");
1559 /* List client->server compression algorithms. */
1560 ssh2_pkt_addstring_start();
1561 for (i
= 0; i
< lenof(compressions
); i
++) {
1562 ssh2_pkt_addstring_str(compressions
[i
]->name
);
1563 if (i
< lenof(compressions
)-1)
1564 ssh2_pkt_addstring_str(",");
1566 /* List server->client compression algorithms. */
1567 ssh2_pkt_addstring_start();
1568 for (i
= 0; i
< lenof(compressions
); i
++) {
1569 ssh2_pkt_addstring_str(compressions
[i
]->name
);
1570 if (i
< lenof(compressions
)-1)
1571 ssh2_pkt_addstring_str(",");
1573 /* List client->server languages. Empty list. */
1574 ssh2_pkt_addstring_start();
1575 /* List server->client languages. Empty list. */
1576 ssh2_pkt_addstring_start();
1577 /* First KEX packet does _not_ follow, because we're not that brave. */
1578 ssh2_pkt_addbool(FALSE
);
1580 ssh2_pkt_adduint32(0);
1581 sha_string(&exhash
, pktout
.data
+5, pktout
.length
-5);
1584 if (!ispkt
) crWaitUntil(ispkt
);
1585 sha_string(&exhash
, pktin
.data
+5, pktin
.length
-5);
1588 * Now examine the other side's KEXINIT to see what we're up
1591 if (pktin
.type
!= SSH2_MSG_KEXINIT
) {
1592 fatalbox("expected key exchange packet from server");
1594 kex
= NULL
; hostkey
= NULL
; cscipher_tobe
= NULL
; sccipher_tobe
= NULL
;
1595 csmac_tobe
= NULL
; scmac_tobe
= NULL
; cscomp_tobe
= NULL
; sccomp_tobe
= NULL
;
1596 pktin
.savedpos
+= 16; /* skip garbage cookie */
1597 ssh2_pkt_getstring(&str
, &len
); /* key exchange algorithms */
1598 for (i
= 0; i
< lenof(kex_algs
); i
++) {
1599 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
1604 ssh2_pkt_getstring(&str
, &len
); /* host key algorithms */
1605 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
1606 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
1607 hostkey
= hostkey_algs
[i
];
1611 ssh2_pkt_getstring(&str
, &len
); /* client->server cipher */
1612 for (i
= 0; i
< lenof(ciphers
); i
++) {
1613 if (in_commasep_string(ciphers
[i
]->name
, str
, len
)) {
1614 cscipher_tobe
= ciphers
[i
];
1618 ssh2_pkt_getstring(&str
, &len
); /* server->client cipher */
1619 for (i
= 0; i
< lenof(ciphers
); i
++) {
1620 if (in_commasep_string(ciphers
[i
]->name
, str
, len
)) {
1621 sccipher_tobe
= ciphers
[i
];
1625 ssh2_pkt_getstring(&str
, &len
); /* client->server mac */
1626 for (i
= 0; i
< lenof(macs
); i
++) {
1627 if (in_commasep_string(macs
[i
]->name
, str
, len
)) {
1628 csmac_tobe
= macs
[i
];
1632 ssh2_pkt_getstring(&str
, &len
); /* server->client mac */
1633 for (i
= 0; i
< lenof(macs
); i
++) {
1634 if (in_commasep_string(macs
[i
]->name
, str
, len
)) {
1635 scmac_tobe
= macs
[i
];
1639 ssh2_pkt_getstring(&str
, &len
); /* client->server compression */
1640 for (i
= 0; i
< lenof(compressions
); i
++) {
1641 if (in_commasep_string(compressions
[i
]->name
, str
, len
)) {
1642 cscomp_tobe
= compressions
[i
];
1646 ssh2_pkt_getstring(&str
, &len
); /* server->client compression */
1647 for (i
= 0; i
< lenof(compressions
); i
++) {
1648 if (in_commasep_string(compressions
[i
]->name
, str
, len
)) {
1649 sccomp_tobe
= compressions
[i
];
1655 * Currently we only support Diffie-Hellman and DSS, so let's
1656 * bomb out if those aren't selected.
1658 if (kex
!= &ssh_diffiehellman
|| hostkey
!= &ssh_dss
)
1659 fatalbox("internal fault: chaos in SSH 2 transport layer");
1662 * Now we begin the fun. Generate and send e for Diffie-Hellman.
1665 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT
);
1670 if (pktin
.type
!= SSH2_MSG_KEXDH_REPLY
) {
1671 fatalbox("expected key exchange packet from server");
1673 ssh2_pkt_getstring(&hostkeydata
, &hostkeylen
);
1674 f
= ssh2_pkt_getmp();
1675 ssh2_pkt_getstring(&sigdata
, &siglen
);
1679 sha_string(&exhash
, hostkeydata
, hostkeylen
);
1680 sha_mpint(&exhash
, e
);
1681 sha_mpint(&exhash
, f
);
1682 sha_mpint(&exhash
, K
);
1683 SHA_Final(&exhash
, exchange_hash
);
1686 debug(("Exchange hash is:\r\n"));
1687 for (i
= 0; i
< 20; i
++)
1688 debug((" %02x", exchange_hash
[i
]));
1692 hostkey
->setkey(hostkeydata
, hostkeylen
);
1693 if (!hostkey
->verifysig(sigdata
, siglen
, exchange_hash
, 20))
1694 fatalbox("Server failed host key check");
1697 * Expect SSH2_MSG_NEWKEYS from server.
1700 if (pktin
.type
!= SSH2_MSG_NEWKEYS
)
1701 fatalbox("expected new-keys packet from server");
1704 * Authenticate remote host: verify host key. (We've already
1705 * checked the signature of the exchange hash.)
1707 keystr
= hostkey
->fmtkey();
1708 verify_ssh_host_key(savedhost
, keystr
);
1712 * Send SSH2_MSG_NEWKEYS.
1714 ssh2_pkt_init(SSH2_MSG_NEWKEYS
);
1718 * Create and initialise session keys.
1720 cscipher
= cscipher_tobe
;
1721 sccipher
= sccipher_tobe
;
1724 cscomp
= cscomp_tobe
;
1725 sccomp
= sccomp_tobe
;
1727 * Set IVs after keys.
1729 ssh2_mkkey(K
, exchange_hash
, 'C', keyspace
); cscipher
->setcskey(keyspace
);
1730 ssh2_mkkey(K
, exchange_hash
, 'D', keyspace
); cscipher
->setsckey(keyspace
);
1731 ssh2_mkkey(K
, exchange_hash
, 'A', keyspace
); cscipher
->setcsiv(keyspace
);
1732 ssh2_mkkey(K
, exchange_hash
, 'B', keyspace
); sccipher
->setsciv(keyspace
);
1733 ssh2_mkkey(K
, exchange_hash
, 'E', keyspace
); csmac
->setcskey(keyspace
);
1734 ssh2_mkkey(K
, exchange_hash
, 'F', keyspace
); scmac
->setsckey(keyspace
);
1737 * Now we're encrypting. Begin returning 1 to the protocol main
1738 * function so that other things can run on top of the
1739 * transport. If we ever see a KEXINIT, we must go back to the
1744 } while (!(ispkt
&& pktin
.type
== SSH2_MSG_KEXINIT
));
1745 goto begin_key_exchange
;
1751 * SSH2: remote identifier for the main session channel.
1753 static unsigned long ssh_remote_channel
;
1756 * Handle the SSH2 userauth and connection layers.
1758 static void do_ssh2_authconn(unsigned char *in
, int inlen
, int ispkt
)
1760 static unsigned long remote_winsize
;
1761 static unsigned long remote_maxpkt
;
1766 * Request userauth protocol, and await a response to it.
1768 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
1769 ssh2_pkt_addstring("ssh-userauth");
1771 crWaitUntilV(ispkt
);
1772 if (pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
)
1773 fatalbox("Server refused user authentication protocol");
1776 * FIXME: currently we support only password authentication.
1777 * (This places us technically in violation of the SSH2 spec.
1778 * We must fix this.)
1782 * Get a username and a password.
1784 static char username
[100];
1785 static char password
[100];
1789 if ((flags
& FLAG_CONNECTION
) && !*cfg
.username
) {
1790 c_write("login as: ", 10);
1792 crWaitUntilV(!ispkt
);
1793 while (inlen
--) switch (c
= *in
++) {
1800 c_write("\b \b", 3);
1806 c_write("\b \b", 3);
1815 if (((c
>= ' ' && c
<= '~') ||
1816 ((unsigned char)c
>= 160)) && pos
< 40) {
1817 username
[pos
++] = c
;
1824 username
[strcspn(username
, "\n\r")] = '\0';
1827 strncpy(username
, cfg
.username
, 99);
1828 username
[99] = '\0';
1829 if (flags
& FLAG_VERBOSE
) {
1830 sprintf(stuff
, "Using username \"%s\".\r\n", username
);
1831 c_write(stuff
, strlen(stuff
));
1835 if (!(flags
& FLAG_WINDOWED
)) {
1837 sprintf(prompt
, "%s@%s's password: ", cfg
.username
, savedhost
);
1838 if (!ssh_get_password(prompt
, password
, sizeof(password
))) {
1840 * get_password failed to get a password (for
1841 * example because one was supplied on the command
1842 * line which has already failed to work).
1845 logevent("No more passwords to try");
1846 ssh_state
= SSH_STATE_CLOSED
;
1850 c_write("password: ", 10);
1854 crWaitUntilV(!ispkt
);
1855 while (inlen
--) switch (c
= *in
++) {
1872 if (((c
>= ' ' && c
<= '~') ||
1873 ((unsigned char)c
>= 160)) && pos
< 40)
1874 password
[pos
++] = c
;
1881 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
1882 ssh2_pkt_addstring(username
);
1883 ssh2_pkt_addstring("ssh-connection"); /* service requested */
1884 ssh2_pkt_addstring("password");
1885 ssh2_pkt_addbool(FALSE
);
1886 ssh2_pkt_addstring(password
);
1889 crWaitUntilV(ispkt
);
1890 if (pktin
.type
!= SSH2_MSG_USERAUTH_SUCCESS
) {
1891 c_write("Access denied\r\n", 15);
1892 logevent("Authentication refused");
1898 * Now we're authenticated for the connection protocol. The
1899 * connection protocol will automatically have started at this
1900 * point; there's no need to send SERVICE_REQUEST.
1904 * So now create a channel with a session in it.
1906 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
1907 ssh2_pkt_addstring("session");
1908 ssh2_pkt_adduint32(100); /* as good as any */
1909 ssh2_pkt_adduint32(0xFFFFFFFFUL
); /* very big window which we ignore */
1910 ssh2_pkt_adduint32(0xFFFFFFFFUL
); /* very big max pkt size */
1912 crWaitUntilV(ispkt
);
1913 if (pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
1914 fatalbox("Server refused to open a session");
1915 /* FIXME: error data comes back in FAILURE packet */
1917 if (ssh2_pkt_getuint32() != 100) {
1918 fatalbox("Server's channel confirmation cited wrong channel");
1920 ssh_remote_channel
= ssh2_pkt_getuint32();
1921 remote_winsize
= ssh2_pkt_getuint32();
1922 remote_maxpkt
= ssh2_pkt_getuint32();
1923 logevent("Opened channel for session");
1926 * Now allocate a pty for the session.
1928 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
1929 ssh2_pkt_adduint32(ssh_remote_channel
); /* recipient channel */
1930 ssh2_pkt_addstring("pty-req");
1931 ssh2_pkt_addbool(1); /* want reply */
1932 ssh2_pkt_addstring(cfg
.termtype
);
1933 ssh2_pkt_adduint32(cols
);
1934 ssh2_pkt_adduint32(rows
);
1935 ssh2_pkt_adduint32(0); /* pixel width */
1936 ssh2_pkt_adduint32(0); /* pixel height */
1937 ssh2_pkt_addstring_start();
1938 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
1941 do { /* FIXME: pay attention to these */
1942 crWaitUntilV(ispkt
);
1943 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
1945 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
1946 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
1947 fatalbox("Server got confused by pty request");
1949 c_write("Server refused to allocate pty\r\n", 32);
1951 logevent("Allocated pty");
1957 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
1958 ssh2_pkt_adduint32(ssh_remote_channel
); /* recipient channel */
1959 ssh2_pkt_addstring("shell");
1960 ssh2_pkt_addbool(1); /* want reply */
1962 do { /* FIXME: pay attention to these */
1963 crWaitUntilV(ispkt
);
1964 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
1965 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
1966 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
1967 fatalbox("Server got confused by shell request");
1969 fatalbox("Server refused to start a shell");
1971 logevent("Started a shell");
1981 if (pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
1982 pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
1985 if (ssh2_pkt_getuint32() != 100)
1986 continue; /* wrong channel */
1987 if (pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
1988 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR
)
1989 continue; /* extended but not stderr */
1990 ssh2_pkt_getstring(&data
, &length
);
1992 c_write(data
, length
);
1993 } else if (pktin
.type
== SSH2_MSG_DISCONNECT
) {
1994 ssh_state
= SSH_STATE_CLOSED
;
1995 logevent("Received disconnect request");
1996 } else if (pktin
.type
== SSH2_MSG_CHANNEL_REQUEST
) {
1997 continue; /* exit status et al; ignore (FIXME?) */
1998 } else if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
1999 continue; /* ignore for now (FIXME!) */
2001 fatalbox("Strange packet received: type %d", pktin
.type
);
2004 /* FIXME: for now, ignore window size */
2005 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA
);
2006 ssh2_pkt_adduint32(ssh_remote_channel
);
2007 ssh2_pkt_addstring_start();
2008 ssh2_pkt_addstring_data(in
, inlen
);
2017 * Handle the top-level SSH2 protocol.
2019 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
)
2021 if (do_ssh2_transport(in
, inlen
, ispkt
) == 0)
2023 do_ssh2_authconn(in
, inlen
, ispkt
);
2027 * Called to set up the connection. Will arrange for WM_NETEVENT
2028 * messages to be passed to the specified window, whose window
2029 * procedure should then call telnet_msg().
2031 * Returns an error message, or NULL on success.
2033 static char *ssh_init (HWND hwnd
, char *host
, int port
, char **realhost
) {
2037 if(crypto_startup() == 0)
2038 return "Microsoft high encryption pack not installed!";
2041 p
= connect_to_host(host
, port
, realhost
);
2046 return "Protocol initialisation error";
2048 if (hwnd
&& WSAAsyncSelect (s
, hwnd
, WM_NETEVENT
, FD_READ
| FD_CLOSE
) == SOCKET_ERROR
)
2049 switch (WSAGetLastError()) {
2050 case WSAENETDOWN
: return "Network is down";
2051 default: return "WSAAsyncSelect(): unknown error";
2058 * Process a WM_NETEVENT message. Will return 0 if the connection
2059 * has closed, or <0 for a socket error.
2061 static int ssh_msg (WPARAM wParam
, LPARAM lParam
) {
2066 * Because reading less than the whole of the available pending
2067 * data can generate an FD_READ event, we need to allow for the
2068 * possibility that FD_READ may arrive with FD_CLOSE already in
2069 * the queue; so it's possible that we can get here even with s
2070 * invalid. If so, we return 1 and don't worry about it.
2072 if (s
== INVALID_SOCKET
)
2075 if (WSAGETSELECTERROR(lParam
) != 0)
2076 return -WSAGETSELECTERROR(lParam
);
2078 switch (WSAGETSELECTEVENT(lParam
)) {
2081 ret
= recv(s
, buf
, sizeof(buf
), 0);
2082 if (ret
< 0 && WSAGetLastError() == WSAEWOULDBLOCK
)
2084 if (ret
< 0) /* any _other_ error */
2085 return -10000-WSAGetLastError();
2090 ssh_gotdata (buf
, ret
);
2091 if (ssh_state
== SSH_STATE_CLOSED
) {
2098 return 1; /* shouldn't happen, but WTF */
2102 * Called to send data down the Telnet connection.
2104 static void ssh_send (char *buf
, int len
) {
2105 if (s
== INVALID_SOCKET
)
2108 ssh_protocol(buf
, len
, 0);
2112 * Called to set the size of the window from Telnet's POV.
2114 static void ssh_size(void) {
2115 switch (ssh_state
) {
2116 case SSH_STATE_BEFORE_SIZE
:
2117 case SSH_STATE_CLOSED
:
2118 break; /* do nothing */
2119 case SSH_STATE_INTERMED
:
2120 size_needed
= TRUE
; /* buffer for later */
2122 case SSH_STATE_SESSION
:
2124 send_packet(SSH1_CMSG_WINDOW_SIZE
,
2125 PKT_INT
, rows
, PKT_INT
, cols
,
2126 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
2132 * Send Telnet special codes. TS_EOF is useful for `plink', so you
2133 * can send an EOF and collect resulting output (e.g. `plink
2136 static void ssh_special (Telnet_Special code
) {
2137 if (code
== TS_EOF
) {
2138 if (ssh_version
= 1) {
2139 send_packet(SSH1_CMSG_EOF
, PKT_END
);
2141 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF
);
2142 ssh2_pkt_adduint32(ssh_remote_channel
);
2152 * Read and decrypt one incoming SSH packet.
2153 * (only used by pSCP)
2155 static void get_packet(void)
2157 unsigned char buf
[4096], *p
;
2164 while ((to_read
= s_rdpkt(&p
, &len
)) > 0) {
2165 if (to_read
> sizeof(buf
)) to_read
= sizeof(buf
);
2166 len
= s_read(buf
, to_read
);
2167 if (len
!= to_read
) {
2179 * Receive a block of data over the SSH link. Block until
2180 * all data is available. Return nr of bytes read (0 if lost connection).
2181 * (only used by pSCP)
2183 int ssh_scp_recv(unsigned char *buf
, int len
)
2185 static int pending_input_len
= 0;
2186 static unsigned char *pending_input_ptr
;
2189 if (pending_input_len
>= to_read
) {
2190 memcpy(buf
, pending_input_ptr
, to_read
);
2191 pending_input_ptr
+= to_read
;
2192 pending_input_len
-= to_read
;
2196 if (pending_input_len
> 0) {
2197 memcpy(buf
, pending_input_ptr
, pending_input_len
);
2198 buf
+= pending_input_len
;
2199 to_read
-= pending_input_len
;
2200 pending_input_len
= 0;
2203 if (s
== INVALID_SOCKET
)
2205 while (to_read
> 0) {
2207 if (s
== INVALID_SOCKET
)
2209 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
) {
2210 int plen
= GET_32BIT(pktin
.body
);
2211 if (plen
<= to_read
) {
2212 memcpy(buf
, pktin
.body
+ 4, plen
);
2216 memcpy(buf
, pktin
.body
+ 4, to_read
);
2217 pending_input_len
= plen
- to_read
;
2218 pending_input_ptr
= pktin
.body
+ 4 + to_read
;
2221 } else if (pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
2222 int plen
= GET_32BIT(pktin
.body
);
2223 fwrite(pktin
.body
+ 4, plen
, 1, stderr
);
2224 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
2225 logevent("Received disconnect request");
2226 } else if (pktin
.type
== SSH1_SMSG_SUCCESS
||
2227 pktin
.type
== SSH1_SMSG_FAILURE
) {
2229 } else if (pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
2231 sprintf(logbuf
, "Remote exit status: %d", GET_32BIT(pktin
.body
));
2233 send_packet(SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
2234 logevent("Closing connection");
2238 fatalbox("Strange packet received: type %d", pktin
.type
);
2246 * Send a block of data over the SSH link.
2247 * Block until all data is sent.
2248 * (only used by pSCP)
2250 void ssh_scp_send(unsigned char *buf
, int len
)
2252 if (s
== INVALID_SOCKET
)
2254 send_packet(SSH1_CMSG_STDIN_DATA
,
2255 PKT_INT
, len
, PKT_DATA
, buf
, len
, PKT_END
);
2259 * Send an EOF notification to the server.
2260 * (only used by pSCP)
2262 void ssh_scp_send_eof(void)
2264 if (s
== INVALID_SOCKET
)
2266 send_packet(SSH1_CMSG_EOF
, PKT_END
);
2270 * Set up the connection, login on the remote host and
2271 * start execution of a command.
2272 * Returns an error message, or NULL on success.
2273 * (only used by pSCP)
2275 char *ssh_scp_init(char *host
, int port
, char *cmd
, char **realhost
)
2280 if (crypto_startup() == 0)
2281 return "Microsoft high encryption pack not installed!";
2284 p
= connect_to_host(host
, port
, realhost
);
2291 return "Protocol initialisation error";
2293 /* Exchange keys and login */
2296 if (s
== INVALID_SOCKET
)
2297 return "Connection closed by remote host";
2298 } while (!do_ssh1_login(NULL
, 0, 1));
2300 if (ssh_state
== SSH_STATE_CLOSED
) {
2303 return "Session initialisation error";
2306 /* Execute command */
2307 sprintf(buf
, "Sending command: %.100s", cmd
);
2309 send_packet(SSH1_CMSG_EXEC_CMD
, PKT_STR
, cmd
, PKT_END
);
2314 static SOCKET
ssh_socket(void) { return s
; }
2316 static int ssh_sendok(void) { return ssh_send_ok
; }
2318 Backend ssh_backend
= {