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
;
168 SSH_STATE_BEFORE_SIZE
,
172 } ssh_state
= SSH_STATE_BEFORE_SIZE
;
174 static int size_needed
= FALSE
;
176 static void s_write (char *buf
, int len
) {
178 int i
= send (s
, buf
, len
, 0);
181 fatalbox("Lost connection while sending");
187 static int s_read (char *buf
, int len
) {
190 int i
= recv (s
, buf
, len
, 0);
193 len
-= i
, buf
+= i
, ret
+= i
;
200 static void c_write (char *buf
, int len
) {
201 if (!(flags
& FLAG_CONNECTION
)) {
203 for (i
= 0; i
< len
; i
++)
205 fputc(buf
[i
], stderr
);
221 static struct Packet pktin
= { 0, 0, NULL
, NULL
, 0 };
222 static struct Packet pktout
= { 0, 0, NULL
, NULL
, 0 };
224 static void (*ssh_protocol
)(unsigned char *in
, int inlen
, int ispkt
);
225 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
);
226 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
);
227 static void ssh_size(void);
229 static int (*s_rdpkt
)(unsigned char **data
, int *datalen
);
232 * Collect incoming data in the incoming packet buffer.
233 * Decipher and verify the packet when it is completely read.
234 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
235 * Update the *data and *datalen variables.
236 * Return the additional nr of bytes needed, or 0 when
237 * a complete packet is available.
239 static int ssh1_rdpkt(unsigned char **data
, int *datalen
)
241 static long len
, pad
, biglen
, to_read
;
242 static unsigned long realcrc
, gotcrc
;
243 static unsigned char *p
;
253 for (i
= len
= 0; i
< 4; i
++) {
254 while ((*datalen
) == 0)
256 len
= (len
<< 8) + **data
;
257 (*data
)++, (*datalen
)--;
261 if (len
== 0x52656d6f) { /* "Remo"te server has closed ... */
262 len
= 0x300; /* big enough to carry to end */
268 pktin
.length
= len
- 5;
270 if (pktin
.maxlen
< biglen
) {
271 pktin
.maxlen
= biglen
;
272 pktin
.data
= (pktin
.data
== NULL ?
malloc(biglen
+APIEXTRA
) :
273 realloc(pktin
.data
, biglen
+APIEXTRA
));
275 fatalbox("Out of memory");
280 while (to_read
> 0) {
283 while ((*datalen
) == 0)
285 if (chunk
> (*datalen
))
287 memcpy(p
, *data
, chunk
);
295 cipher
->decrypt(pktin
.data
, biglen
);
297 pktin
.type
= pktin
.data
[pad
];
298 pktin
.body
= pktin
.data
+ pad
+ 1;
300 realcrc
= crc32(pktin
.data
, biglen
-4);
301 gotcrc
= GET_32BIT(pktin
.data
+biglen
-4);
302 if (gotcrc
!= realcrc
) {
303 fatalbox("Incorrect CRC received on packet");
306 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
307 pktin
.type
== SSH1_SMSG_STDERR_DATA
||
308 pktin
.type
== SSH1_MSG_DEBUG
||
309 pktin
.type
== SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
310 long strlen
= GET_32BIT(pktin
.body
);
311 if (strlen
+ 4 != pktin
.length
)
312 fatalbox("Received data packet with bogus string length");
315 if (pktin
.type
== SSH1_MSG_DEBUG
) {
316 /* log debug message */
318 int strlen
= GET_32BIT(pktin
.body
);
319 strcpy(buf
, "Remote: ");
320 if (strlen
> 70) strlen
= 70;
321 memcpy(buf
+8, pktin
.body
+4, strlen
);
322 buf
[8+strlen
] = '\0';
325 } else if (pktin
.type
== SSH1_MSG_IGNORE
) {
333 static int ssh2_rdpkt(unsigned char **data
, int *datalen
)
335 static long len
, pad
, payload
, packetlen
, maclen
;
337 static int cipherblk
;
338 static unsigned long incoming_sequence
= 0;
348 cipherblk
= cipher
->blksize
;
354 if (pktin
.maxlen
< cipherblk
) {
355 pktin
.maxlen
= cipherblk
;
356 pktin
.data
= (pktin
.data
== NULL ?
malloc(cipherblk
+APIEXTRA
) :
357 realloc(pktin
.data
, cipherblk
+APIEXTRA
));
359 fatalbox("Out of memory");
363 * Acquire and decrypt the first block of the packet. This will
364 * contain the length and padding details.
366 for (i
= len
= 0; i
< cipherblk
; i
++) {
367 while ((*datalen
) == 0)
368 crReturn(cipherblk
-i
);
369 pktin
.data
[i
] = *(*data
)++;
373 if (!memcmp(pktin
.data
, "Remo", 4)) {/* "Remo"te server has closed ... */
378 sccipher
->decrypt(pktin
.data
, cipherblk
);
381 * Now get the length and padding figures.
383 len
= GET_32BIT(pktin
.data
);
387 * This enables us to deduce the payload length.
389 payload
= len
- pad
- 1;
391 pktin
.length
= payload
+ 5;
394 * So now we can work out the total packet length.
397 maclen
= scmac ? scmac
->len
: 0;
400 * Adjust memory allocation if packet is too big.
402 if (pktin
.maxlen
< packetlen
) {
403 pktin
.maxlen
= packetlen
;
404 pktin
.data
= (pktin
.data
== NULL ?
malloc(packetlen
+APIEXTRA
) :
405 realloc(pktin
.data
, packetlen
+APIEXTRA
));
407 fatalbox("Out of memory");
411 * Read and decrypt the remainder of the packet.
413 for (i
= cipherblk
; i
< packetlen
+ maclen
; i
++) {
414 while ((*datalen
) == 0)
415 crReturn(packetlen
+ maclen
- i
);
416 pktin
.data
[i
] = *(*data
)++;
419 /* Decrypt everything _except_ the MAC. */
421 sccipher
->decrypt(pktin
.data
+ cipherblk
, packetlen
- cipherblk
);
424 debug(("Got packet len=%d pad=%d\r\n", len
, pad
));
425 for (i
= 0; i
< packetlen
; i
++)
426 debug((" %02x", (unsigned char)pktin
.data
[i
]));
433 if (scmac
&& !scmac
->verify(pktin
.data
, len
+4, incoming_sequence
))
434 fatalbox("Incorrect MAC received on packet");
435 incoming_sequence
++; /* whether or not we MACed */
438 pktin
.type
= pktin
.data
[5];
440 if (pktin
.type
== SSH2_MSG_IGNORE
|| pktin
.type
== SSH2_MSG_DEBUG
)
441 goto next_packet
; /* FIXME: print DEBUG message */
446 static void ssh_gotdata(unsigned char *data
, int datalen
)
448 while (datalen
> 0) {
449 if ( s_rdpkt(&data
, &datalen
) == 0 ) {
450 ssh_protocol(NULL
, 0, 1);
451 if (ssh_state
== SSH_STATE_CLOSED
) {
459 static void s_wrpkt_start(int type
, int len
) {
462 len
+= 5; /* type and CRC */
466 pktout
.length
= len
-5;
467 if (pktout
.maxlen
< biglen
) {
468 pktout
.maxlen
= biglen
;
470 /* Allocate enough buffer space for extra block
471 * for MS CryptEncrypt() */
472 pktout
.data
= (pktout
.data
== NULL ?
malloc(biglen
+12) :
473 realloc(pktout
.data
, biglen
+12));
475 pktout
.data
= (pktout
.data
== NULL ?
malloc(biglen
+4) :
476 realloc(pktout
.data
, biglen
+4));
479 fatalbox("Out of memory");
483 pktout
.body
= pktout
.data
+4+pad
+1;
486 static void s_wrpkt(void) {
487 int pad
, len
, biglen
, i
;
490 len
= pktout
.length
+ 5; /* type and CRC */
494 pktout
.body
[-1] = pktout
.type
;
495 for (i
=0; i
<pad
; i
++)
496 pktout
.data
[i
+4] = random_byte();
497 crc
= crc32(pktout
.data
+4, biglen
-4);
498 PUT_32BIT(pktout
.data
+biglen
, crc
);
499 PUT_32BIT(pktout
.data
, len
);
502 cipher
->encrypt(pktout
.data
+4, biglen
);
504 s_write(pktout
.data
, biglen
+4);
508 * Construct a packet with the specified contents and
509 * send it to the server.
511 static void send_packet(int pkttype
, ...)
514 unsigned char *p
, *argp
, argchar
;
515 unsigned long argint
;
516 int pktlen
, argtype
, arglen
;
521 va_start(args
, pkttype
);
522 while ((argtype
= va_arg(args
, int)) != PKT_END
) {
525 (void) va_arg(args
, int);
529 (void) va_arg(args
, char);
533 (void) va_arg(args
, unsigned char *);
534 arglen
= va_arg(args
, int);
538 argp
= va_arg(args
, unsigned char *);
539 arglen
= strlen(argp
);
540 pktlen
+= 4 + arglen
;
543 bn
= va_arg(args
, Bignum
);
545 while ( i
> 0 && (bn
[i
/16+1] >> (i
%16)) == 0 )
547 pktlen
+= 2 + (i
+7)/8;
555 s_wrpkt_start(pkttype
, pktlen
);
558 va_start(args
, pkttype
);
559 while ((argtype
= va_arg(args
, int)) != PKT_END
) {
562 argint
= va_arg(args
, int);
563 PUT_32BIT(p
, argint
);
567 argchar
= va_arg(args
, unsigned char);
572 argp
= va_arg(args
, unsigned char *);
573 arglen
= va_arg(args
, int);
574 memcpy(p
, argp
, arglen
);
578 argp
= va_arg(args
, unsigned char *);
579 arglen
= strlen(argp
);
580 PUT_32BIT(p
, arglen
);
581 memcpy(p
+ 4, argp
, arglen
);
585 bn
= va_arg(args
, Bignum
);
587 while ( i
> 0 && (bn
[i
/16+1] >> (i
%16)) == 0 )
589 *p
++ = (i
>> 8) & 0xFF;
594 *p
++ = bn
[i
/2+1] >> 8;
596 *p
++ = bn
[i
/2+1] & 0xFF;
608 * Connect to specified host and port.
609 * Returns an error message, or NULL on success.
610 * Also places the canonical host name into `realhost'.
612 static char *connect_to_host(char *host
, int port
, char **realhost
)
622 savedhost
= malloc(1+strlen(host
));
624 fatalbox("Out of memory");
625 strcpy(savedhost
, host
);
628 port
= 22; /* default ssh port */
640 if ( (a
= inet_addr(host
)) == (unsigned long) INADDR_NONE
) {
641 if ( (h
= gethostbyname(host
)) == NULL
)
642 switch (WSAGetLastError()) {
643 case WSAENETDOWN
: return "Network is down";
644 case WSAHOST_NOT_FOUND
: case WSANO_DATA
:
645 return "Host does not exist";
646 case WSATRY_AGAIN
: return "Host not found";
647 default: return "gethostbyname: unknown error";
649 memcpy (&a
, h
->h_addr
, sizeof(a
));
650 *realhost
= h
->h_name
;
661 s
= socket(AF_INET
, SOCK_STREAM
, 0);
662 if (s
== INVALID_SOCKET
)
663 switch (WSAGetLastError()) {
664 case WSAENETDOWN
: return "Network is down";
665 case WSAEAFNOSUPPORT
: return "TCP/IP support not present";
666 default: return "socket(): unknown error";
670 * Bind to local address.
672 addr
.sin_family
= AF_INET
;
673 addr
.sin_addr
.s_addr
= htonl(INADDR_ANY
);
674 addr
.sin_port
= htons(0);
675 if (bind (s
, (struct sockaddr
*)&addr
, sizeof(addr
)) == SOCKET_ERROR
)
676 switch (WSAGetLastError()) {
677 case WSAENETDOWN
: return "Network is down";
678 default: return "bind(): unknown error";
682 * Connect to remote address.
684 addr
.sin_addr
.s_addr
= htonl(a
);
685 addr
.sin_port
= htons((short)port
);
686 if (connect (s
, (struct sockaddr
*)&addr
, sizeof(addr
)) == SOCKET_ERROR
)
687 switch (WSAGetLastError()) {
688 case WSAENETDOWN
: return "Network is down";
689 case WSAECONNREFUSED
: return "Connection refused";
690 case WSAENETUNREACH
: return "Network is unreachable";
691 case WSAEHOSTUNREACH
: return "No route to host";
692 default: return "connect(): unknown error";
696 send(s
, "connect ", 8, 0);
697 send(s
, FWhost
, strlen(FWhost
), 0);
700 sprintf(buf
, " %d\n", FWport
);
701 send (s
, buf
, strlen(buf
), 0);
708 static int ssh_versioncmp(char *a
, char *b
) {
710 unsigned long av
, bv
;
712 av
= strtoul(a
, &ae
, 10);
713 bv
= strtoul(b
, &be
, 10);
714 if (av
!= bv
) return (av
< bv ?
-1 : +1);
715 if (*ae
== '.') ae
++;
716 if (*be
== '.') be
++;
717 av
= strtoul(ae
, &ae
, 10);
718 bv
= strtoul(be
, &be
, 10);
719 if (av
!= bv
) return (av
< bv ?
-1 : +1);
725 * Utility routine for putting an SSH-protocol `string' into a SHA
729 void sha_string(SHA_State
*s
, void *str
, int len
) {
730 unsigned char lenblk
[4];
732 PUT_32BIT(lenblk
, len
);
733 if (!fp
) fp
= fopen("h:\\statham\\windows\\putty\\data","wb");
734 fwrite(lenblk
, 4, 1, fp
);
735 SHA_Bytes(s
, lenblk
, 4);
736 fwrite(str
, len
, 1, fp
);
738 SHA_Bytes(s
, str
, len
);
742 * SSH2 packet construction functions.
744 void ssh2_pkt_adddata(void *data
, int len
) {
745 pktout
.length
+= len
;
746 if (pktout
.maxlen
< pktout
.length
) {
747 pktout
.maxlen
= pktout
.length
+ 256;
748 pktout
.data
= (pktout
.data
== NULL ?
malloc(pktout
.maxlen
+APIEXTRA
) :
749 realloc(pktout
.data
, pktout
.maxlen
+APIEXTRA
));
751 fatalbox("Out of memory");
753 memcpy(pktout
.data
+pktout
.length
-len
, data
, len
);
755 void ssh2_pkt_addbyte(unsigned char byte
) {
756 ssh2_pkt_adddata(&byte
, 1);
758 void ssh2_pkt_init(int pkt_type
) {
760 ssh2_pkt_addbyte((unsigned char)pkt_type
);
762 void ssh2_pkt_addbool(unsigned char value
) {
763 ssh2_pkt_adddata(&value
, 1);
765 void ssh2_pkt_adduint32(unsigned long value
) {
768 ssh2_pkt_adddata(x
, 4);
770 void ssh2_pkt_addstring_start(void) {
771 ssh2_pkt_adduint32(0);
772 pktout
.savedpos
= pktout
.length
;
774 void ssh2_pkt_addstring_str(char *data
) {
775 ssh2_pkt_adddata(data
, strlen(data
));
776 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
777 pktout
.length
- pktout
.savedpos
);
779 void ssh2_pkt_addstring_data(char *data
, int len
) {
780 ssh2_pkt_adddata(data
, len
);
781 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
782 pktout
.length
- pktout
.savedpos
);
784 void ssh2_pkt_addstring(char *data
) {
785 ssh2_pkt_addstring_start();
786 ssh2_pkt_addstring_str(data
);
788 char *ssh2_mpint_fmt(Bignum b
, int *len
) {
791 p
= malloc(n
* 2 + 1);
793 fatalbox("out of memory");
795 for (i
= 0; i
< n
; i
++) {
796 p
[i
*2+1] = (b
[n
-i
] >> 8) & 0xFF;
797 p
[i
*2+2] = (b
[n
-i
] ) & 0xFF;
800 while (p
[i
] == 0 && (p
[i
+1] & 0x80) == 0)
802 memmove(p
, p
+i
, n
*2+1-i
);
806 void ssh2_pkt_addmp(Bignum b
) {
809 p
= ssh2_mpint_fmt(b
, &len
);
810 ssh2_pkt_addstring_start();
811 ssh2_pkt_addstring_data(p
, len
);
814 void ssh2_pkt_send(void) {
815 int cipherblk
, maclen
, padding
, i
;
816 static unsigned long outgoing_sequence
= 0;
819 * Add padding. At least four bytes, and must also bring total
820 * length (minus MAC) up to a multiple of the block size.
822 cipherblk
= cipher ? cipher
->blksize
: 8; /* block size */
823 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
825 padding
+= (cipherblk
- (pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
826 pktout
.data
[4] = padding
;
827 for (i
= 0; i
< padding
; i
++)
828 pktout
.data
[pktout
.length
+ i
] = random_byte();
829 PUT_32BIT(pktout
.data
, pktout
.length
+ padding
- 4);
831 csmac
->generate(pktout
.data
, pktout
.length
+ padding
,
833 outgoing_sequence
++; /* whether or not we MACed */
836 debug(("Sending packet len=%d\r\n", pktout
.length
+padding
));
837 for (i
= 0; i
< pktout
.length
+padding
; i
++)
838 debug((" %02x", (unsigned char)pktout
.data
[i
]));
843 cscipher
->encrypt(pktout
.data
, pktout
.length
+ padding
);
844 maclen
= csmac ? csmac
->len
: 0;
846 s_write(pktout
.data
, pktout
.length
+ padding
+ maclen
);
850 void bndebug(char *string
, Bignum b
) {
853 p
= ssh2_mpint_fmt(b
, &len
);
854 debug(("%s", string
));
855 for (i
= 0; i
< len
; i
++)
856 debug((" %02x", p
[i
]));
862 void sha_mpint(SHA_State
*s
, Bignum b
) {
865 p
= ssh2_mpint_fmt(b
, &len
);
866 sha_string(s
, p
, len
);
871 * SSH2 packet decode functions.
873 unsigned long ssh2_pkt_getuint32(void) {
875 if (pktin
.length
- pktin
.savedpos
< 4)
876 return 0; /* arrgh, no way to decline (FIXME?) */
877 value
= GET_32BIT(pktin
.data
+pktin
.savedpos
);
881 void ssh2_pkt_getstring(char **p
, int *length
) {
883 if (pktin
.length
- pktin
.savedpos
< 4)
885 *length
= GET_32BIT(pktin
.data
+pktin
.savedpos
);
887 if (pktin
.length
- pktin
.savedpos
< *length
)
889 *p
= pktin
.data
+pktin
.savedpos
;
890 pktin
.savedpos
+= *length
;
892 Bignum
ssh2_pkt_getmp(void) {
897 ssh2_pkt_getstring(&p
, &length
);
901 fatalbox("internal error: Can't handle negative mpints");
902 b
= newbn((length
+1)/2);
903 for (i
= 0; i
< length
; i
++) {
906 b
[j
/2+1] |= ((unsigned char)p
[i
]) << 8;
908 b
[j
/2+1] |= ((unsigned char)p
[i
]);
913 static int do_ssh_init(void) {
917 char vlog
[sizeof(vstring
)+20];
922 while (s_read(&c
, 1) == 1) {
923 if (c
== 'S' && i
< 2) i
++;
924 else if (c
== 'S' && i
== 2) i
= 2;
925 else if (c
== 'H' && i
== 2) break;
929 if (s_read(&c
,1) != 1 || c
!= 'S') return 0;
930 if (s_read(&c
,1) != 1 || c
!= 'S') return 0;
931 if (s_read(&c
,1) != 1 || c
!= 'H') return 0;
933 strcpy(vstring
, "SSH-");
935 if (s_read(&c
,1) != 1 || c
!= '-') return 0;
938 if (s_read(&c
,1) != 1)
940 if (vsp
< vstring
+sizeof(vstring
)-1)
946 } else if (i
< sizeof(version
)-1)
954 sprintf(vlog
, "Server version: %s", vstring
);
955 vlog
[strcspn(vlog
, "\r\n")] = '\0';
958 if (ssh_versioncmp(version
, "2.0" /* FIXME: "1.99" */ ) >= 0) {
960 * This is a v2 server. Begin v2 protocol.
962 char *verstring
= "SSH-2.0-PuTTY";
965 * Hash our version string and their version string.
967 sha_string(&exhash
, verstring
, strlen(verstring
));
968 sha_string(&exhash
, vstring
, strcspn(vstring
, "\r\n"));
969 sprintf(vstring
, "%s\n", verstring
);
970 sprintf(vlog
, "We claim version: %s", verstring
);
972 logevent("Using SSH protocol version 2");
973 s_write(vstring
, strlen(vstring
));
974 ssh_protocol
= ssh2_protocol
;
975 s_rdpkt
= ssh2_rdpkt
;
978 * This is a v1 server. Begin v1 protocol.
980 sprintf(vstring
, "SSH-%s-PuTTY\n",
981 (ssh_versioncmp(version
, "1.5") <= 0 ? version
: "1.5"));
982 sprintf(vlog
, "We claim version: %s", vstring
);
983 vlog
[strcspn(vlog
, "\r\n")] = '\0';
985 logevent("Using SSH protocol version 1");
986 s_write(vstring
, strlen(vstring
));
987 ssh_protocol
= ssh1_protocol
;
988 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 send_packet(SSH1_CMSG_EXEC_SHELL
, PKT_END
);
1402 logevent("Started session");
1404 ssh_state
= SSH_STATE_SESSION
;
1411 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
1412 pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
1413 long len
= GET_32BIT(pktin
.body
);
1414 c_write(pktin
.body
+4, len
);
1415 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
1416 ssh_state
= SSH_STATE_CLOSED
;
1417 logevent("Received disconnect request");
1418 } else if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
1419 /* may be from EXEC_SHELL on some servers */
1420 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1421 /* may be from EXEC_SHELL on some servers
1422 * if no pty is available or in other odd cases. Ignore */
1423 } else if (pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
1424 send_packet(SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
1426 fatalbox("Strange packet received: type %d", pktin
.type
);
1429 send_packet(SSH1_CMSG_STDIN_DATA
,
1430 PKT_INT
, inlen
, PKT_DATA
, in
, inlen
, PKT_END
);
1438 * Utility routine for decoding comma-separated strings in KEXINIT.
1440 int in_commasep_string(char *needle
, char *haystack
, int haylen
) {
1441 int needlen
= strlen(needle
);
1444 * Is it at the start of the string?
1446 if (haylen
>= needlen
&& /* haystack is long enough */
1447 !memcmp(needle
, haystack
, needlen
) && /* initial match */
1448 (haylen
== needlen
|| haystack
[needlen
] == ',')
1449 /* either , or EOS follows */
1453 * If not, search for the next comma and resume after that.
1454 * If no comma found, terminate.
1456 while (haylen
> 0 && *haystack
!= ',')
1457 haylen
--, haystack
++;
1460 haylen
--, haystack
++; /* skip over comma itself */
1465 * SSH2 key creation method.
1467 void ssh2_mkkey(Bignum K
, char *H
, char chr
, char *keyspace
) {
1469 /* First 20 bytes. */
1472 SHA_Bytes(&s
, H
, 20);
1473 SHA_Bytes(&s
, &chr
, 1);
1474 SHA_Bytes(&s
, H
, 20);
1475 SHA_Final(&s
, keyspace
);
1476 /* Next 20 bytes. */
1479 SHA_Bytes(&s
, H
, 20);
1480 SHA_Bytes(&s
, keyspace
, 20);
1481 SHA_Final(&s
, keyspace
+20);
1485 * Handle the SSH2 transport layer.
1487 static int do_ssh2_transport(unsigned char *in
, int inlen
, int ispkt
)
1491 static Bignum e
, f
, K
;
1492 static struct ssh_cipher
*cscipher_tobe
= NULL
;
1493 static struct ssh_cipher
*sccipher_tobe
= NULL
;
1494 static struct ssh_mac
*csmac_tobe
= NULL
;
1495 static struct ssh_mac
*scmac_tobe
= NULL
;
1496 static struct ssh_compress
*cscomp_tobe
= NULL
;
1497 static struct ssh_compress
*sccomp_tobe
= NULL
;
1498 static char *hostkeydata
, *sigdata
, *keystr
;
1499 static int hostkeylen
, siglen
;
1500 static unsigned char exchange_hash
[20];
1501 static unsigned char keyspace
[40];
1508 * Construct and send our key exchange packet.
1510 ssh2_pkt_init(SSH2_MSG_KEXINIT
);
1511 for (i
= 0; i
< 16; i
++)
1512 ssh2_pkt_addbyte((unsigned char)random_byte());
1513 /* List key exchange algorithms. */
1514 ssh2_pkt_addstring_start();
1515 for (i
= 0; i
< lenof(kex_algs
); i
++) {
1516 ssh2_pkt_addstring_str(kex_algs
[i
]->name
);
1517 if (i
< lenof(kex_algs
)-1)
1518 ssh2_pkt_addstring_str(",");
1520 /* List server host key algorithms. */
1521 ssh2_pkt_addstring_start();
1522 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
1523 ssh2_pkt_addstring_str(hostkey_algs
[i
]->name
);
1524 if (i
< lenof(hostkey_algs
)-1)
1525 ssh2_pkt_addstring_str(",");
1527 /* List client->server encryption algorithms. */
1528 ssh2_pkt_addstring_start();
1529 for (i
= 0; i
< lenof(ciphers
); i
++) {
1530 ssh2_pkt_addstring_str(ciphers
[i
]->name
);
1531 if (i
< lenof(ciphers
)-1)
1532 ssh2_pkt_addstring_str(",");
1534 /* List server->client encryption algorithms. */
1535 ssh2_pkt_addstring_start();
1536 for (i
= 0; i
< lenof(ciphers
); i
++) {
1537 ssh2_pkt_addstring_str(ciphers
[i
]->name
);
1538 if (i
< lenof(ciphers
)-1)
1539 ssh2_pkt_addstring_str(",");
1541 /* List client->server MAC algorithms. */
1542 ssh2_pkt_addstring_start();
1543 for (i
= 0; i
< lenof(macs
); i
++) {
1544 ssh2_pkt_addstring_str(macs
[i
]->name
);
1545 if (i
< lenof(macs
)-1)
1546 ssh2_pkt_addstring_str(",");
1548 /* List server->client MAC algorithms. */
1549 ssh2_pkt_addstring_start();
1550 for (i
= 0; i
< lenof(macs
); i
++) {
1551 ssh2_pkt_addstring_str(macs
[i
]->name
);
1552 if (i
< lenof(macs
)-1)
1553 ssh2_pkt_addstring_str(",");
1555 /* List client->server compression algorithms. */
1556 ssh2_pkt_addstring_start();
1557 for (i
= 0; i
< lenof(compressions
); i
++) {
1558 ssh2_pkt_addstring_str(compressions
[i
]->name
);
1559 if (i
< lenof(compressions
)-1)
1560 ssh2_pkt_addstring_str(",");
1562 /* List server->client compression algorithms. */
1563 ssh2_pkt_addstring_start();
1564 for (i
= 0; i
< lenof(compressions
); i
++) {
1565 ssh2_pkt_addstring_str(compressions
[i
]->name
);
1566 if (i
< lenof(compressions
)-1)
1567 ssh2_pkt_addstring_str(",");
1569 /* List client->server languages. Empty list. */
1570 ssh2_pkt_addstring_start();
1571 /* List server->client languages. Empty list. */
1572 ssh2_pkt_addstring_start();
1573 /* First KEX packet does _not_ follow, because we're not that brave. */
1574 ssh2_pkt_addbool(FALSE
);
1576 ssh2_pkt_adduint32(0);
1577 sha_string(&exhash
, pktout
.data
+5, pktout
.length
-5);
1580 if (!ispkt
) crWaitUntil(ispkt
);
1581 sha_string(&exhash
, pktin
.data
+5, pktin
.length
-5);
1584 * Now examine the other side's KEXINIT to see what we're up
1587 if (pktin
.type
!= SSH2_MSG_KEXINIT
) {
1588 fatalbox("expected key exchange packet from server");
1590 kex
= NULL
; hostkey
= NULL
; cscipher_tobe
= NULL
; sccipher_tobe
= NULL
;
1591 csmac_tobe
= NULL
; scmac_tobe
= NULL
; cscomp_tobe
= NULL
; sccomp_tobe
= NULL
;
1592 pktin
.savedpos
+= 16; /* skip garbage cookie */
1593 ssh2_pkt_getstring(&str
, &len
); /* key exchange algorithms */
1594 for (i
= 0; i
< lenof(kex_algs
); i
++) {
1595 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
1600 ssh2_pkt_getstring(&str
, &len
); /* host key algorithms */
1601 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
1602 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
1603 hostkey
= hostkey_algs
[i
];
1607 ssh2_pkt_getstring(&str
, &len
); /* client->server cipher */
1608 for (i
= 0; i
< lenof(ciphers
); i
++) {
1609 if (in_commasep_string(ciphers
[i
]->name
, str
, len
)) {
1610 cscipher_tobe
= ciphers
[i
];
1614 ssh2_pkt_getstring(&str
, &len
); /* server->client cipher */
1615 for (i
= 0; i
< lenof(ciphers
); i
++) {
1616 if (in_commasep_string(ciphers
[i
]->name
, str
, len
)) {
1617 sccipher_tobe
= ciphers
[i
];
1621 ssh2_pkt_getstring(&str
, &len
); /* client->server mac */
1622 for (i
= 0; i
< lenof(macs
); i
++) {
1623 if (in_commasep_string(macs
[i
]->name
, str
, len
)) {
1624 csmac_tobe
= macs
[i
];
1628 ssh2_pkt_getstring(&str
, &len
); /* server->client mac */
1629 for (i
= 0; i
< lenof(macs
); i
++) {
1630 if (in_commasep_string(macs
[i
]->name
, str
, len
)) {
1631 scmac_tobe
= macs
[i
];
1635 ssh2_pkt_getstring(&str
, &len
); /* client->server compression */
1636 for (i
= 0; i
< lenof(compressions
); i
++) {
1637 if (in_commasep_string(compressions
[i
]->name
, str
, len
)) {
1638 cscomp_tobe
= compressions
[i
];
1642 ssh2_pkt_getstring(&str
, &len
); /* server->client compression */
1643 for (i
= 0; i
< lenof(compressions
); i
++) {
1644 if (in_commasep_string(compressions
[i
]->name
, str
, len
)) {
1645 sccomp_tobe
= compressions
[i
];
1651 * Currently we only support Diffie-Hellman and DSS, so let's
1652 * bomb out if those aren't selected.
1654 if (kex
!= &ssh_diffiehellman
|| hostkey
!= &ssh_dss
)
1655 fatalbox("internal fault: chaos in SSH 2 transport layer");
1658 * Now we begin the fun. Generate and send e for Diffie-Hellman.
1661 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT
);
1666 if (pktin
.type
!= SSH2_MSG_KEXDH_REPLY
) {
1667 fatalbox("expected key exchange packet from server");
1669 ssh2_pkt_getstring(&hostkeydata
, &hostkeylen
);
1670 f
= ssh2_pkt_getmp();
1671 ssh2_pkt_getstring(&sigdata
, &siglen
);
1675 sha_string(&exhash
, hostkeydata
, hostkeylen
);
1676 sha_mpint(&exhash
, e
);
1677 sha_mpint(&exhash
, f
);
1678 sha_mpint(&exhash
, K
);
1679 SHA_Final(&exhash
, exchange_hash
);
1682 debug(("Exchange hash is:\r\n"));
1683 for (i
= 0; i
< 20; i
++)
1684 debug((" %02x", exchange_hash
[i
]));
1688 hostkey
->setkey(hostkeydata
, hostkeylen
);
1689 if (!hostkey
->verifysig(sigdata
, siglen
, exchange_hash
, 20))
1690 fatalbox("Server failed host key check");
1693 * Expect SSH2_MSG_NEWKEYS from server.
1696 if (pktin
.type
!= SSH2_MSG_NEWKEYS
)
1697 fatalbox("expected new-keys packet from server");
1700 * Authenticate remote host: verify host key. (We've already
1701 * checked the signature of the exchange hash.)
1703 keystr
= hostkey
->fmtkey();
1704 verify_ssh_host_key(savedhost
, keystr
);
1708 * Send SSH2_MSG_NEWKEYS.
1710 ssh2_pkt_init(SSH2_MSG_NEWKEYS
);
1714 * Create and initialise session keys.
1716 cscipher
= cscipher_tobe
;
1717 sccipher
= sccipher_tobe
;
1720 cscomp
= cscomp_tobe
;
1721 sccomp
= sccomp_tobe
;
1723 * Set IVs after keys.
1725 ssh2_mkkey(K
, exchange_hash
, 'C', keyspace
); cscipher
->setcskey(keyspace
);
1726 ssh2_mkkey(K
, exchange_hash
, 'D', keyspace
); cscipher
->setsckey(keyspace
);
1727 ssh2_mkkey(K
, exchange_hash
, 'A', keyspace
); cscipher
->setcsiv(keyspace
);
1728 ssh2_mkkey(K
, exchange_hash
, 'B', keyspace
); sccipher
->setsciv(keyspace
);
1729 ssh2_mkkey(K
, exchange_hash
, 'E', keyspace
); csmac
->setcskey(keyspace
);
1730 ssh2_mkkey(K
, exchange_hash
, 'F', keyspace
); scmac
->setsckey(keyspace
);
1733 * Now we're encrypting. Begin returning 1 to the protocol main
1734 * function so that other things can run on top of the
1735 * transport. If we ever see a KEXINIT, we must go back to the
1740 } while (!(ispkt
&& pktin
.type
== SSH2_MSG_KEXINIT
));
1741 goto begin_key_exchange
;
1747 * Handle the SSH2 userauth and connection layers.
1749 static void do_ssh2_authconn(unsigned char *in
, int inlen
, int ispkt
)
1751 static unsigned long their_channel
;
1752 static unsigned long remote_winsize
;
1753 static unsigned long remote_maxpkt
;
1758 * Request userauth protocol, and await a response to it.
1760 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
1761 ssh2_pkt_addstring("ssh-userauth");
1763 crWaitUntilV(ispkt
);
1764 if (pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
)
1765 fatalbox("Server refused user authentication protocol");
1768 * FIXME: currently we support only password authentication.
1769 * (This places us technically in violation of the SSH2 spec.
1770 * We must fix this.)
1774 * Get a username and a password.
1776 static char username
[100];
1777 static char password
[100];
1781 if ((flags
& FLAG_CONNECTION
) && !*cfg
.username
) {
1782 c_write("login as: ", 10);
1784 crWaitUntilV(!ispkt
);
1785 while (inlen
--) switch (c
= *in
++) {
1792 c_write("\b \b", 3);
1798 c_write("\b \b", 3);
1807 if (((c
>= ' ' && c
<= '~') ||
1808 ((unsigned char)c
>= 160)) && pos
< 40) {
1809 username
[pos
++] = c
;
1816 username
[strcspn(username
, "\n\r")] = '\0';
1819 strncpy(username
, cfg
.username
, 99);
1820 username
[99] = '\0';
1821 if (flags
& FLAG_VERBOSE
) {
1822 sprintf(stuff
, "Using username \"%s\".\r\n", username
);
1823 c_write(stuff
, strlen(stuff
));
1827 if (!(flags
& FLAG_WINDOWED
)) {
1829 sprintf(prompt
, "%s@%s's password: ", cfg
.username
, savedhost
);
1830 if (!ssh_get_password(prompt
, password
, sizeof(password
))) {
1832 * get_password failed to get a password (for
1833 * example because one was supplied on the command
1834 * line which has already failed to work).
1837 logevent("No more passwords to try");
1838 ssh_state
= SSH_STATE_CLOSED
;
1842 c_write("password: ", 10);
1846 crWaitUntilV(!ispkt
);
1847 while (inlen
--) switch (c
= *in
++) {
1864 if (((c
>= ' ' && c
<= '~') ||
1865 ((unsigned char)c
>= 160)) && pos
< 40)
1866 password
[pos
++] = c
;
1873 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
1874 ssh2_pkt_addstring(username
);
1875 ssh2_pkt_addstring("ssh-connection"); /* service requested */
1876 ssh2_pkt_addstring("password");
1877 ssh2_pkt_addbool(FALSE
);
1878 ssh2_pkt_addstring(password
);
1881 crWaitUntilV(ispkt
);
1882 if (pktin
.type
!= SSH2_MSG_USERAUTH_SUCCESS
) {
1883 c_write("Access denied\r\n", 15);
1884 logevent("Authentication refused");
1890 * Now we're authenticated for the connection protocol. The
1891 * connection protocol will automatically have started at this
1892 * point; there's no need to send SERVICE_REQUEST.
1896 * So now create a channel with a session in it.
1898 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
1899 ssh2_pkt_addstring("session");
1900 ssh2_pkt_adduint32(100); /* as good as any */
1901 ssh2_pkt_adduint32(0xFFFFFFFFUL
); /* very big window which we ignore */
1902 ssh2_pkt_adduint32(0xFFFFFFFFUL
); /* very big max pkt size */
1904 crWaitUntilV(ispkt
);
1905 if (pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
1906 fatalbox("Server refused to open a session");
1907 /* FIXME: error data comes back in FAILURE packet */
1909 if (ssh2_pkt_getuint32() != 100) {
1910 fatalbox("Server's channel confirmation cited wrong channel");
1912 their_channel
= ssh2_pkt_getuint32();
1913 remote_winsize
= ssh2_pkt_getuint32();
1914 remote_maxpkt
= ssh2_pkt_getuint32();
1915 logevent("Opened channel for session");
1918 * Now allocate a pty for the session.
1920 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
1921 ssh2_pkt_adduint32(their_channel
); /* recipient channel */
1922 ssh2_pkt_addstring("pty-req");
1923 ssh2_pkt_addbool(1); /* want reply */
1924 ssh2_pkt_addstring(cfg
.termtype
);
1925 ssh2_pkt_adduint32(cols
);
1926 ssh2_pkt_adduint32(rows
);
1927 ssh2_pkt_adduint32(0); /* pixel width */
1928 ssh2_pkt_adduint32(0); /* pixel height */
1929 ssh2_pkt_addstring_start();
1930 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
1933 do { /* FIXME: pay attention to these */
1934 crWaitUntilV(ispkt
);
1935 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
1937 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
1938 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
1939 fatalbox("Server got confused by pty request");
1941 c_write("Server refused to allocate pty\r\n", 32);
1943 logevent("Allocated pty");
1949 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
1950 ssh2_pkt_adduint32(their_channel
); /* recipient channel */
1951 ssh2_pkt_addstring("shell");
1952 ssh2_pkt_addbool(1); /* want reply */
1954 do { /* FIXME: pay attention to these */
1955 crWaitUntilV(ispkt
);
1956 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
1957 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
1958 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
1959 fatalbox("Server got confused by shell request");
1961 fatalbox("Server refused to start a shell");
1963 logevent("Started a shell");
1972 if (pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
1973 pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
1976 if (ssh2_pkt_getuint32() != 100)
1977 continue; /* wrong channel */
1978 if (pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
1979 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR
)
1980 continue; /* extended but not stderr */
1981 ssh2_pkt_getstring(&data
, &length
);
1983 c_write(data
, length
);
1984 } else if (pktin
.type
== SSH2_MSG_DISCONNECT
) {
1985 ssh_state
= SSH_STATE_CLOSED
;
1986 logevent("Received disconnect request");
1987 } else if (pktin
.type
== SSH2_MSG_CHANNEL_REQUEST
) {
1988 continue; /* exit status et al; ignore (FIXME?) */
1989 } else if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
1990 continue; /* ignore for now (FIXME!) */
1992 fatalbox("Strange packet received: type %d", pktin
.type
);
1995 /* FIXME: for now, ignore window size */
1996 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA
);
1997 ssh2_pkt_adduint32(their_channel
);
1998 ssh2_pkt_addstring_start();
1999 ssh2_pkt_addstring_data(in
, inlen
);
2008 * Handle the top-level SSH2 protocol.
2010 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
)
2012 if (do_ssh2_transport(in
, inlen
, ispkt
) == 0)
2014 do_ssh2_authconn(in
, inlen
, ispkt
);
2018 * Called to set up the connection. Will arrange for WM_NETEVENT
2019 * messages to be passed to the specified window, whose window
2020 * procedure should then call telnet_msg().
2022 * Returns an error message, or NULL on success.
2024 static char *ssh_init (HWND hwnd
, char *host
, int port
, char **realhost
) {
2028 if(crypto_startup() == 0)
2029 return "Microsoft high encryption pack not installed!";
2032 p
= connect_to_host(host
, port
, realhost
);
2037 return "Protocol initialisation error";
2039 if (hwnd
&& WSAAsyncSelect (s
, hwnd
, WM_NETEVENT
, FD_READ
| FD_CLOSE
) == SOCKET_ERROR
)
2040 switch (WSAGetLastError()) {
2041 case WSAENETDOWN
: return "Network is down";
2042 default: return "WSAAsyncSelect(): unknown error";
2049 * Process a WM_NETEVENT message. Will return 0 if the connection
2050 * has closed, or <0 for a socket error.
2052 static int ssh_msg (WPARAM wParam
, LPARAM lParam
) {
2057 * Because reading less than the whole of the available pending
2058 * data can generate an FD_READ event, we need to allow for the
2059 * possibility that FD_READ may arrive with FD_CLOSE already in
2060 * the queue; so it's possible that we can get here even with s
2061 * invalid. If so, we return 1 and don't worry about it.
2063 if (s
== INVALID_SOCKET
)
2066 if (WSAGETSELECTERROR(lParam
) != 0)
2067 return -WSAGETSELECTERROR(lParam
);
2069 switch (WSAGETSELECTEVENT(lParam
)) {
2072 ret
= recv(s
, buf
, sizeof(buf
), 0);
2073 if (ret
< 0 && WSAGetLastError() == WSAEWOULDBLOCK
)
2075 if (ret
< 0) /* any _other_ error */
2076 return -10000-WSAGetLastError();
2081 ssh_gotdata (buf
, ret
);
2082 if (ssh_state
== SSH_STATE_CLOSED
) {
2089 return 1; /* shouldn't happen, but WTF */
2093 * Called to send data down the Telnet connection.
2095 static void ssh_send (char *buf
, int len
) {
2096 if (s
== INVALID_SOCKET
)
2099 ssh_protocol(buf
, len
, 0);
2103 * Called to set the size of the window from Telnet's POV.
2105 static void ssh_size(void) {
2106 switch (ssh_state
) {
2107 case SSH_STATE_BEFORE_SIZE
:
2108 case SSH_STATE_CLOSED
:
2109 break; /* do nothing */
2110 case SSH_STATE_INTERMED
:
2111 size_needed
= TRUE
; /* buffer for later */
2113 case SSH_STATE_SESSION
:
2115 send_packet(SSH1_CMSG_WINDOW_SIZE
,
2116 PKT_INT
, rows
, PKT_INT
, cols
,
2117 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
2123 * (Send Telnet special codes)
2125 static void ssh_special (Telnet_Special code
) {
2131 * Read and decrypt one incoming SSH packet.
2132 * (only used by pSCP)
2134 static void get_packet(void)
2136 unsigned char buf
[4096], *p
;
2143 while ((to_read
= s_rdpkt(&p
, &len
)) > 0) {
2144 if (to_read
> sizeof(buf
)) to_read
= sizeof(buf
);
2145 len
= s_read(buf
, to_read
);
2146 if (len
!= to_read
) {
2158 * Receive a block of data over the SSH link. Block until
2159 * all data is available. Return nr of bytes read (0 if lost connection).
2160 * (only used by pSCP)
2162 int ssh_scp_recv(unsigned char *buf
, int len
)
2164 static int pending_input_len
= 0;
2165 static unsigned char *pending_input_ptr
;
2168 if (pending_input_len
>= to_read
) {
2169 memcpy(buf
, pending_input_ptr
, to_read
);
2170 pending_input_ptr
+= to_read
;
2171 pending_input_len
-= to_read
;
2175 if (pending_input_len
> 0) {
2176 memcpy(buf
, pending_input_ptr
, pending_input_len
);
2177 buf
+= pending_input_len
;
2178 to_read
-= pending_input_len
;
2179 pending_input_len
= 0;
2182 if (s
== INVALID_SOCKET
)
2184 while (to_read
> 0) {
2186 if (s
== INVALID_SOCKET
)
2188 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
) {
2189 int plen
= GET_32BIT(pktin
.body
);
2190 if (plen
<= to_read
) {
2191 memcpy(buf
, pktin
.body
+ 4, plen
);
2195 memcpy(buf
, pktin
.body
+ 4, to_read
);
2196 pending_input_len
= plen
- to_read
;
2197 pending_input_ptr
= pktin
.body
+ 4 + to_read
;
2200 } else if (pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
2201 int plen
= GET_32BIT(pktin
.body
);
2202 fwrite(pktin
.body
+ 4, plen
, 1, stderr
);
2203 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
2204 logevent("Received disconnect request");
2205 } else if (pktin
.type
== SSH1_SMSG_SUCCESS
||
2206 pktin
.type
== SSH1_SMSG_FAILURE
) {
2208 } else if (pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
2210 sprintf(logbuf
, "Remote exit status: %d", GET_32BIT(pktin
.body
));
2212 send_packet(SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
2213 logevent("Closing connection");
2217 fatalbox("Strange packet received: type %d", pktin
.type
);
2225 * Send a block of data over the SSH link.
2226 * Block until all data is sent.
2227 * (only used by pSCP)
2229 void ssh_scp_send(unsigned char *buf
, int len
)
2231 if (s
== INVALID_SOCKET
)
2233 send_packet(SSH1_CMSG_STDIN_DATA
,
2234 PKT_INT
, len
, PKT_DATA
, buf
, len
, PKT_END
);
2238 * Send an EOF notification to the server.
2239 * (only used by pSCP)
2241 void ssh_scp_send_eof(void)
2243 if (s
== INVALID_SOCKET
)
2245 send_packet(SSH1_CMSG_EOF
, PKT_END
);
2249 * Set up the connection, login on the remote host and
2250 * start execution of a command.
2251 * Returns an error message, or NULL on success.
2252 * (only used by pSCP)
2254 char *ssh_scp_init(char *host
, int port
, char *cmd
, char **realhost
)
2259 if (crypto_startup() == 0)
2260 return "Microsoft high encryption pack not installed!";
2263 p
= connect_to_host(host
, port
, realhost
);
2270 return "Protocol initialisation error";
2272 /* Exchange keys and login */
2275 if (s
== INVALID_SOCKET
)
2276 return "Connection closed by remote host";
2277 } while (!do_ssh1_login(NULL
, 0, 1));
2279 if (ssh_state
== SSH_STATE_CLOSED
) {
2282 return "Session initialisation error";
2285 /* Execute command */
2286 sprintf(buf
, "Sending command: %.100s", cmd
);
2288 send_packet(SSH1_CMSG_EXEC_CMD
, PKT_STR
, cmd
, PKT_END
);
2293 SOCKET
ssh_socket(void) { return s
; }
2295 Backend ssh_backend
= {