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];
734 PUT_32BIT(lenblk
, len
);
735 if (!fp
) fp
= fopen("h:\\statham\\windows\\putty\\data","wb");
736 fwrite(lenblk
, 4, 1, fp
);
737 SHA_Bytes(s
, lenblk
, 4);
738 fwrite(str
, len
, 1, fp
);
740 SHA_Bytes(s
, str
, len
);
744 * SSH2 packet construction functions.
746 void ssh2_pkt_adddata(void *data
, int len
) {
747 pktout
.length
+= len
;
748 if (pktout
.maxlen
< pktout
.length
) {
749 pktout
.maxlen
= pktout
.length
+ 256;
750 pktout
.data
= (pktout
.data
== NULL ?
malloc(pktout
.maxlen
+APIEXTRA
) :
751 realloc(pktout
.data
, pktout
.maxlen
+APIEXTRA
));
753 fatalbox("Out of memory");
755 memcpy(pktout
.data
+pktout
.length
-len
, data
, len
);
757 void ssh2_pkt_addbyte(unsigned char byte
) {
758 ssh2_pkt_adddata(&byte
, 1);
760 void ssh2_pkt_init(int pkt_type
) {
762 ssh2_pkt_addbyte((unsigned char)pkt_type
);
764 void ssh2_pkt_addbool(unsigned char value
) {
765 ssh2_pkt_adddata(&value
, 1);
767 void ssh2_pkt_adduint32(unsigned long value
) {
770 ssh2_pkt_adddata(x
, 4);
772 void ssh2_pkt_addstring_start(void) {
773 ssh2_pkt_adduint32(0);
774 pktout
.savedpos
= pktout
.length
;
776 void ssh2_pkt_addstring_str(char *data
) {
777 ssh2_pkt_adddata(data
, strlen(data
));
778 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
779 pktout
.length
- pktout
.savedpos
);
781 void ssh2_pkt_addstring_data(char *data
, int len
) {
782 ssh2_pkt_adddata(data
, len
);
783 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
784 pktout
.length
- pktout
.savedpos
);
786 void ssh2_pkt_addstring(char *data
) {
787 ssh2_pkt_addstring_start();
788 ssh2_pkt_addstring_str(data
);
790 char *ssh2_mpint_fmt(Bignum b
, int *len
) {
793 p
= malloc(n
* 2 + 1);
795 fatalbox("out of memory");
797 for (i
= 0; i
< n
; i
++) {
798 p
[i
*2+1] = (b
[n
-i
] >> 8) & 0xFF;
799 p
[i
*2+2] = (b
[n
-i
] ) & 0xFF;
802 while (p
[i
] == 0 && (p
[i
+1] & 0x80) == 0)
804 memmove(p
, p
+i
, n
*2+1-i
);
808 void ssh2_pkt_addmp(Bignum b
) {
811 p
= ssh2_mpint_fmt(b
, &len
);
812 ssh2_pkt_addstring_start();
813 ssh2_pkt_addstring_data(p
, len
);
816 void ssh2_pkt_send(void) {
817 int cipherblk
, maclen
, padding
, i
;
818 static unsigned long outgoing_sequence
= 0;
821 * Add padding. At least four bytes, and must also bring total
822 * length (minus MAC) up to a multiple of the block size.
824 cipherblk
= cipher ? cipher
->blksize
: 8; /* block size */
825 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
827 padding
+= (cipherblk
- (pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
828 pktout
.data
[4] = padding
;
829 for (i
= 0; i
< padding
; i
++)
830 pktout
.data
[pktout
.length
+ i
] = random_byte();
831 PUT_32BIT(pktout
.data
, pktout
.length
+ padding
- 4);
833 csmac
->generate(pktout
.data
, pktout
.length
+ padding
,
835 outgoing_sequence
++; /* whether or not we MACed */
838 debug(("Sending packet len=%d\r\n", pktout
.length
+padding
));
839 for (i
= 0; i
< pktout
.length
+padding
; i
++)
840 debug((" %02x", (unsigned char)pktout
.data
[i
]));
845 cscipher
->encrypt(pktout
.data
, pktout
.length
+ padding
);
846 maclen
= csmac ? csmac
->len
: 0;
848 s_write(pktout
.data
, pktout
.length
+ padding
+ maclen
);
852 void bndebug(char *string
, Bignum b
) {
855 p
= ssh2_mpint_fmt(b
, &len
);
856 debug(("%s", string
));
857 for (i
= 0; i
< len
; i
++)
858 debug((" %02x", p
[i
]));
864 void sha_mpint(SHA_State
*s
, Bignum b
) {
867 p
= ssh2_mpint_fmt(b
, &len
);
868 sha_string(s
, p
, len
);
873 * SSH2 packet decode functions.
875 unsigned long ssh2_pkt_getuint32(void) {
877 if (pktin
.length
- pktin
.savedpos
< 4)
878 return 0; /* arrgh, no way to decline (FIXME?) */
879 value
= GET_32BIT(pktin
.data
+pktin
.savedpos
);
883 void ssh2_pkt_getstring(char **p
, int *length
) {
885 if (pktin
.length
- pktin
.savedpos
< 4)
887 *length
= GET_32BIT(pktin
.data
+pktin
.savedpos
);
889 if (pktin
.length
- pktin
.savedpos
< *length
)
891 *p
= pktin
.data
+pktin
.savedpos
;
892 pktin
.savedpos
+= *length
;
894 Bignum
ssh2_pkt_getmp(void) {
899 ssh2_pkt_getstring(&p
, &length
);
903 fatalbox("internal error: Can't handle negative mpints");
904 b
= newbn((length
+1)/2);
905 for (i
= 0; i
< length
; i
++) {
908 b
[j
/2+1] |= ((unsigned char)p
[i
]) << 8;
910 b
[j
/2+1] |= ((unsigned char)p
[i
]);
915 static int do_ssh_init(void) {
919 char vlog
[sizeof(vstring
)+20];
924 while (s_read(&c
, 1) == 1) {
925 if (c
== 'S' && i
< 2) i
++;
926 else if (c
== 'S' && i
== 2) i
= 2;
927 else if (c
== 'H' && i
== 2) break;
931 if (s_read(&c
,1) != 1 || c
!= 'S') return 0;
932 if (s_read(&c
,1) != 1 || c
!= 'S') return 0;
933 if (s_read(&c
,1) != 1 || c
!= 'H') return 0;
935 strcpy(vstring
, "SSH-");
937 if (s_read(&c
,1) != 1 || c
!= '-') return 0;
940 if (s_read(&c
,1) != 1)
942 if (vsp
< vstring
+sizeof(vstring
)-1)
948 } else if (i
< sizeof(version
)-1)
956 sprintf(vlog
, "Server version: %s", vstring
);
957 vlog
[strcspn(vlog
, "\r\n")] = '\0';
960 if (ssh_versioncmp(version
, "2.0" /* FIXME: "1.99" */ ) >= 0) {
962 * This is a v2 server. Begin v2 protocol.
964 char *verstring
= "SSH-2.0-PuTTY";
967 * Hash our version string and their version string.
969 sha_string(&exhash
, verstring
, strlen(verstring
));
970 sha_string(&exhash
, vstring
, strcspn(vstring
, "\r\n"));
971 sprintf(vstring
, "%s\n", verstring
);
972 sprintf(vlog
, "We claim version: %s", verstring
);
974 logevent("Using SSH protocol version 2");
975 s_write(vstring
, strlen(vstring
));
976 ssh_protocol
= ssh2_protocol
;
978 s_rdpkt
= ssh2_rdpkt
;
981 * This is a v1 server. Begin v1 protocol.
983 sprintf(vstring
, "SSH-%s-PuTTY\n",
984 (ssh_versioncmp(version
, "1.5") <= 0 ? version
: "1.5"));
985 sprintf(vlog
, "We claim version: %s", vstring
);
986 vlog
[strcspn(vlog
, "\r\n")] = '\0';
988 logevent("Using SSH protocol version 1");
989 s_write(vstring
, strlen(vstring
));
990 ssh_protocol
= ssh1_protocol
;
992 s_rdpkt
= ssh1_rdpkt
;
999 * Handle the key exchange and user authentication phases.
1001 static int do_ssh1_login(unsigned char *in
, int inlen
, int ispkt
)
1004 unsigned char *rsabuf
, *keystr1
, *keystr2
;
1005 unsigned char cookie
[8];
1006 struct RSAKey servkey
, hostkey
;
1007 struct MD5Context md5c
;
1008 static unsigned long supported_ciphers_mask
, supported_auths_mask
;
1009 static int tried_publickey
;
1010 static unsigned char session_id
[16];
1015 if (!ispkt
) crWaitUntil(ispkt
);
1017 if (pktin
.type
!= SSH1_SMSG_PUBLIC_KEY
)
1018 fatalbox("Public key packet not received");
1020 logevent("Received public keys");
1022 memcpy(cookie
, pktin
.body
, 8);
1024 i
= makekey(pktin
.body
+8, &servkey
, &keystr1
, 0);
1025 j
= makekey(pktin
.body
+8+i
, &hostkey
, &keystr2
, 0);
1028 * Hash the host key and print the hash in the log box. Just as
1029 * a last resort in case the registry's host key checking is
1030 * compromised, we'll allow the user some ability to verify
1034 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
1035 MD5Final(session_id
, &md5c
);
1039 logevent("Host key MD5 is:");
1040 strcpy(logmsg
, " ");
1041 for (i
= 0; i
< 16; i
++)
1042 sprintf(logmsg
+strlen(logmsg
), "%02x", session_id
[i
]);
1046 supported_ciphers_mask
= GET_32BIT(pktin
.body
+12+i
+j
);
1047 supported_auths_mask
= GET_32BIT(pktin
.body
+16+i
+j
);
1050 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
1051 MD5Update(&md5c
, keystr1
, servkey
.bytes
);
1052 MD5Update(&md5c
, pktin
.body
, 8);
1053 MD5Final(session_id
, &md5c
);
1055 for (i
=0; i
<32; i
++)
1056 session_key
[i
] = random_byte();
1058 len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
1060 rsabuf
= malloc(len
);
1062 fatalbox("Out of memory");
1065 * Verify the host key.
1069 * First format the key into a string.
1071 int len
= rsastr_len(&hostkey
);
1072 char *keystr
= malloc(len
);
1074 fatalbox("Out of memory");
1075 rsastr_fmt(keystr
, &hostkey
);
1076 verify_ssh_host_key(savedhost
, keystr
);
1080 for (i
=0; i
<32; i
++) {
1081 rsabuf
[i
] = session_key
[i
];
1083 rsabuf
[i
] ^= session_id
[i
];
1086 if (hostkey
.bytes
> servkey
.bytes
) {
1087 rsaencrypt(rsabuf
, 32, &servkey
);
1088 rsaencrypt(rsabuf
, servkey
.bytes
, &hostkey
);
1090 rsaencrypt(rsabuf
, 32, &hostkey
);
1091 rsaencrypt(rsabuf
, hostkey
.bytes
, &servkey
);
1094 logevent("Encrypted session key");
1096 cipher_type
= cfg
.cipher
== CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH
:
1097 cfg
.cipher
== CIPHER_DES ? SSH_CIPHER_DES
:
1099 if ((supported_ciphers_mask
& (1 << cipher_type
)) == 0) {
1100 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1101 cipher_type
= SSH_CIPHER_3DES
;
1103 switch (cipher_type
) {
1104 case SSH_CIPHER_3DES
: logevent("Using 3DES encryption"); break;
1105 case SSH_CIPHER_DES
: logevent("Using single-DES encryption"); break;
1106 case SSH_CIPHER_BLOWFISH
: logevent("Using Blowfish encryption"); break;
1109 send_packet(SSH1_CMSG_SESSION_KEY
,
1110 PKT_CHAR
, cipher_type
,
1111 PKT_DATA
, cookie
, 8,
1112 PKT_CHAR
, (len
*8) >> 8, PKT_CHAR
, (len
*8) & 0xFF,
1113 PKT_DATA
, rsabuf
, len
,
1117 logevent("Trying to enable encryption...");
1121 cipher
= cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish
:
1122 cipher_type
== SSH_CIPHER_DES ?
&ssh_des
:
1124 cipher
->sesskey(session_key
);
1128 if (pktin
.type
!= SSH1_SMSG_SUCCESS
)
1129 fatalbox("Encryption not successfully enabled");
1131 logevent("Successfully started encryption");
1135 static char username
[100];
1138 if (!(flags
& FLAG_CONNECTION
) && !*cfg
.username
) {
1139 c_write("login as: ", 10);
1141 crWaitUntil(!ispkt
);
1142 while (inlen
--) switch (c
= *in
++) {
1149 c_write("\b \b", 3);
1155 c_write("\b \b", 3);
1164 if (((c
>= ' ' && c
<= '~') ||
1165 ((unsigned char)c
>= 160)) && pos
< 40) {
1166 username
[pos
++] = c
;
1173 username
[strcspn(username
, "\n\r")] = '\0';
1176 strncpy(username
, cfg
.username
, 99);
1177 username
[99] = '\0';
1178 if (flags
& FLAG_VERBOSE
) {
1179 sprintf(stuff
, "Sent username \"%s\".\r\n", username
);
1180 c_write(stuff
, strlen(stuff
));
1184 send_packet(SSH1_CMSG_USER
, PKT_STR
, username
, PKT_END
);
1186 char userlog
[20+sizeof(username
)];
1187 sprintf(userlog
, "Sent username \"%s\"", username
);
1194 tried_publickey
= 0;
1196 while (pktin
.type
== SSH1_SMSG_FAILURE
) {
1197 static char password
[100];
1200 static int pwpkt_type
;
1202 * Show password prompt, having first obtained it via a TIS
1203 * exchange if we're doing TIS authentication.
1205 pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
1206 if (*cfg
.keyfile
&& !tried_publickey
)
1207 pwpkt_type
= SSH1_CMSG_AUTH_RSA
;
1209 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
&& !FLAG_WINDOWED
) {
1211 sprintf(prompt
, "%s@%s's password: ", cfg
.username
, savedhost
);
1212 if (!ssh_get_password(prompt
, password
, sizeof(password
))) {
1214 * get_password failed to get a password (for
1215 * example because one was supplied on the command
1216 * line which has already failed to work).
1219 logevent("No more passwords to try");
1220 ssh_state
= SSH_STATE_CLOSED
;
1225 if (pktin
.type
== SSH1_SMSG_FAILURE
&&
1227 (supported_auths_mask
& (1<<SSH1_AUTH_TIS
))) {
1228 pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
1229 logevent("Requested TIS authentication");
1230 send_packet(SSH1_CMSG_AUTH_TIS
, PKT_END
);
1232 if (pktin
.type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
1233 logevent("TIS authentication declined");
1234 c_write("TIS authentication refused.\r\n", 29);
1236 int challengelen
= ((pktin
.body
[0] << 24) |
1237 (pktin
.body
[1] << 16) |
1238 (pktin
.body
[2] << 8) |
1240 logevent("Received TIS challenge");
1241 c_write(pktin
.body
+4, challengelen
);
1244 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
)
1245 c_write("password: ", 10);
1246 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
1247 if (flags
& FLAG_VERBOSE
)
1248 c_write("Trying public key authentication.\r\n", 35);
1249 if (!rsakey_encrypted(cfg
.keyfile
)) {
1250 if (flags
& FLAG_VERBOSE
)
1251 c_write("No passphrase required.\r\n", 25);
1254 c_write("passphrase: ", 12);
1259 crWaitUntil(!ispkt
);
1260 while (inlen
--) switch (c
= *in
++) {
1277 if (((c
>= ' ' && c
<= '~') ||
1278 ((unsigned char)c
>= 160)) && pos
< sizeof(password
))
1279 password
[pos
++] = c
;
1288 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
1290 * Try public key authentication with the specified
1293 static struct RSAKey pubkey
;
1294 static Bignum challenge
, response
;
1296 static unsigned char buffer
[32];
1298 tried_publickey
= 1;
1299 i
= loadrsakey(cfg
.keyfile
, &pubkey
, password
);
1301 c_write("Couldn't load public key from ", 30);
1302 c_write(cfg
.keyfile
, strlen(cfg
.keyfile
));
1303 c_write(".\r\n", 3);
1304 continue; /* go and try password */
1307 c_write("Wrong passphrase.\r\n", 19);
1308 tried_publickey
= 0;
1309 continue; /* try again */
1313 * Send a public key attempt.
1315 send_packet(SSH1_CMSG_AUTH_RSA
,
1316 PKT_BIGNUM
, pubkey
.modulus
, PKT_END
);
1319 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1320 if (flags
& FLAG_VERBOSE
)
1321 c_write("Server refused our public key.\r\n", 32);
1322 continue; /* go and try password */
1324 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
)
1325 fatalbox("Bizarre response to offer of public key");
1326 ssh1_read_bignum(pktin
.body
, &challenge
);
1327 response
= rsadecrypt(challenge
, &pubkey
);
1328 freebn(pubkey
.private_exponent
); /* burn the evidence */
1330 for (i
= 0; i
< 32; i
+= 2) {
1331 buffer
[i
] = response
[16-i
/2] >> 8;
1332 buffer
[i
+1] = response
[16-i
/2] & 0xFF;
1336 MD5Update(&md5c
, buffer
, 32);
1337 MD5Update(&md5c
, session_id
, 16);
1338 MD5Final(buffer
, &md5c
);
1340 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
1341 PKT_DATA
, buffer
, 16, PKT_END
);
1344 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1345 if (flags
& FLAG_VERBOSE
)
1346 c_write("Failed to authenticate with our public key.\r\n",
1348 continue; /* go and try password */
1349 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1350 fatalbox("Bizarre response to RSA authentication response");
1353 break; /* we're through! */
1355 send_packet(pwpkt_type
, PKT_STR
, password
, PKT_END
);
1357 logevent("Sent password");
1358 memset(password
, 0, strlen(password
));
1360 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1361 if (flags
& FLAG_VERBOSE
)
1362 c_write("Access denied\r\n", 15);
1363 logevent("Authentication refused");
1364 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
1365 logevent("Received disconnect request");
1366 ssh_state
= SSH_STATE_CLOSED
;
1368 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1369 fatalbox("Strange packet received, type %d", pktin
.type
);
1373 logevent("Authentication successful");
1378 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
) {
1383 while (!do_ssh1_login(in
, inlen
, ispkt
)) {
1386 if (ssh_state
== SSH_STATE_CLOSED
)
1390 send_packet(SSH1_CMSG_REQUEST_PTY
,
1391 PKT_STR
, cfg
.termtype
,
1392 PKT_INT
, rows
, PKT_INT
, cols
,
1393 PKT_INT
, 0, PKT_INT
, 0,
1396 ssh_state
= SSH_STATE_INTERMED
;
1397 do { crReturnV
; } while (!ispkt
);
1398 if (pktin
.type
!= SSH1_SMSG_SUCCESS
&& pktin
.type
!= SSH1_SMSG_FAILURE
) {
1399 fatalbox("Protocol confusion");
1400 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1401 c_write("Server refused to allocate pty\r\n", 32);
1403 logevent("Allocated pty");
1406 if (*cfg
.remote_cmd
)
1407 send_packet(SSH1_CMSG_EXEC_CMD
, PKT_STR
, cfg
.remote_cmd
, PKT_END
);
1409 send_packet(SSH1_CMSG_EXEC_SHELL
, PKT_END
);
1410 logevent("Started session");
1412 ssh_state
= SSH_STATE_SESSION
;
1420 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
1421 pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
1422 long len
= GET_32BIT(pktin
.body
);
1423 c_write(pktin
.body
+4, len
);
1424 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
1425 ssh_state
= SSH_STATE_CLOSED
;
1426 logevent("Received disconnect request");
1427 } else if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
1428 /* may be from EXEC_SHELL on some servers */
1429 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1430 /* may be from EXEC_SHELL on some servers
1431 * if no pty is available or in other odd cases. Ignore */
1432 } else if (pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
1433 send_packet(SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
1435 fatalbox("Strange packet received: type %d", pktin
.type
);
1438 send_packet(SSH1_CMSG_STDIN_DATA
,
1439 PKT_INT
, inlen
, PKT_DATA
, in
, inlen
, PKT_END
);
1447 * Utility routine for decoding comma-separated strings in KEXINIT.
1449 int in_commasep_string(char *needle
, char *haystack
, int haylen
) {
1450 int needlen
= strlen(needle
);
1453 * Is it at the start of the string?
1455 if (haylen
>= needlen
&& /* haystack is long enough */
1456 !memcmp(needle
, haystack
, needlen
) && /* initial match */
1457 (haylen
== needlen
|| haystack
[needlen
] == ',')
1458 /* either , or EOS follows */
1462 * If not, search for the next comma and resume after that.
1463 * If no comma found, terminate.
1465 while (haylen
> 0 && *haystack
!= ',')
1466 haylen
--, haystack
++;
1469 haylen
--, haystack
++; /* skip over comma itself */
1474 * SSH2 key creation method.
1476 void ssh2_mkkey(Bignum K
, char *H
, char chr
, char *keyspace
) {
1478 /* First 20 bytes. */
1481 SHA_Bytes(&s
, H
, 20);
1482 SHA_Bytes(&s
, &chr
, 1);
1483 SHA_Bytes(&s
, H
, 20);
1484 SHA_Final(&s
, keyspace
);
1485 /* Next 20 bytes. */
1488 SHA_Bytes(&s
, H
, 20);
1489 SHA_Bytes(&s
, keyspace
, 20);
1490 SHA_Final(&s
, keyspace
+20);
1494 * Handle the SSH2 transport layer.
1496 static int do_ssh2_transport(unsigned char *in
, int inlen
, int ispkt
)
1500 static Bignum e
, f
, K
;
1501 static struct ssh_cipher
*cscipher_tobe
= NULL
;
1502 static struct ssh_cipher
*sccipher_tobe
= NULL
;
1503 static struct ssh_mac
*csmac_tobe
= NULL
;
1504 static struct ssh_mac
*scmac_tobe
= NULL
;
1505 static struct ssh_compress
*cscomp_tobe
= NULL
;
1506 static struct ssh_compress
*sccomp_tobe
= NULL
;
1507 static char *hostkeydata
, *sigdata
, *keystr
;
1508 static int hostkeylen
, siglen
;
1509 static unsigned char exchange_hash
[20];
1510 static unsigned char keyspace
[40];
1517 * Construct and send our key exchange packet.
1519 ssh2_pkt_init(SSH2_MSG_KEXINIT
);
1520 for (i
= 0; i
< 16; i
++)
1521 ssh2_pkt_addbyte((unsigned char)random_byte());
1522 /* List key exchange algorithms. */
1523 ssh2_pkt_addstring_start();
1524 for (i
= 0; i
< lenof(kex_algs
); i
++) {
1525 ssh2_pkt_addstring_str(kex_algs
[i
]->name
);
1526 if (i
< lenof(kex_algs
)-1)
1527 ssh2_pkt_addstring_str(",");
1529 /* List server host key algorithms. */
1530 ssh2_pkt_addstring_start();
1531 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
1532 ssh2_pkt_addstring_str(hostkey_algs
[i
]->name
);
1533 if (i
< lenof(hostkey_algs
)-1)
1534 ssh2_pkt_addstring_str(",");
1536 /* List client->server encryption algorithms. */
1537 ssh2_pkt_addstring_start();
1538 for (i
= 0; i
< lenof(ciphers
); i
++) {
1539 ssh2_pkt_addstring_str(ciphers
[i
]->name
);
1540 if (i
< lenof(ciphers
)-1)
1541 ssh2_pkt_addstring_str(",");
1543 /* List server->client encryption algorithms. */
1544 ssh2_pkt_addstring_start();
1545 for (i
= 0; i
< lenof(ciphers
); i
++) {
1546 ssh2_pkt_addstring_str(ciphers
[i
]->name
);
1547 if (i
< lenof(ciphers
)-1)
1548 ssh2_pkt_addstring_str(",");
1550 /* List client->server MAC algorithms. */
1551 ssh2_pkt_addstring_start();
1552 for (i
= 0; i
< lenof(macs
); i
++) {
1553 ssh2_pkt_addstring_str(macs
[i
]->name
);
1554 if (i
< lenof(macs
)-1)
1555 ssh2_pkt_addstring_str(",");
1557 /* List server->client MAC algorithms. */
1558 ssh2_pkt_addstring_start();
1559 for (i
= 0; i
< lenof(macs
); i
++) {
1560 ssh2_pkt_addstring_str(macs
[i
]->name
);
1561 if (i
< lenof(macs
)-1)
1562 ssh2_pkt_addstring_str(",");
1564 /* List client->server compression algorithms. */
1565 ssh2_pkt_addstring_start();
1566 for (i
= 0; i
< lenof(compressions
); i
++) {
1567 ssh2_pkt_addstring_str(compressions
[i
]->name
);
1568 if (i
< lenof(compressions
)-1)
1569 ssh2_pkt_addstring_str(",");
1571 /* List server->client compression algorithms. */
1572 ssh2_pkt_addstring_start();
1573 for (i
= 0; i
< lenof(compressions
); i
++) {
1574 ssh2_pkt_addstring_str(compressions
[i
]->name
);
1575 if (i
< lenof(compressions
)-1)
1576 ssh2_pkt_addstring_str(",");
1578 /* List client->server languages. Empty list. */
1579 ssh2_pkt_addstring_start();
1580 /* List server->client languages. Empty list. */
1581 ssh2_pkt_addstring_start();
1582 /* First KEX packet does _not_ follow, because we're not that brave. */
1583 ssh2_pkt_addbool(FALSE
);
1585 ssh2_pkt_adduint32(0);
1586 sha_string(&exhash
, pktout
.data
+5, pktout
.length
-5);
1589 if (!ispkt
) crWaitUntil(ispkt
);
1590 sha_string(&exhash
, pktin
.data
+5, pktin
.length
-5);
1593 * Now examine the other side's KEXINIT to see what we're up
1596 if (pktin
.type
!= SSH2_MSG_KEXINIT
) {
1597 fatalbox("expected key exchange packet from server");
1599 kex
= NULL
; hostkey
= NULL
; cscipher_tobe
= NULL
; sccipher_tobe
= NULL
;
1600 csmac_tobe
= NULL
; scmac_tobe
= NULL
; cscomp_tobe
= NULL
; sccomp_tobe
= NULL
;
1601 pktin
.savedpos
+= 16; /* skip garbage cookie */
1602 ssh2_pkt_getstring(&str
, &len
); /* key exchange algorithms */
1603 for (i
= 0; i
< lenof(kex_algs
); i
++) {
1604 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
1609 ssh2_pkt_getstring(&str
, &len
); /* host key algorithms */
1610 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
1611 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
1612 hostkey
= hostkey_algs
[i
];
1616 ssh2_pkt_getstring(&str
, &len
); /* client->server cipher */
1617 for (i
= 0; i
< lenof(ciphers
); i
++) {
1618 if (in_commasep_string(ciphers
[i
]->name
, str
, len
)) {
1619 cscipher_tobe
= ciphers
[i
];
1623 ssh2_pkt_getstring(&str
, &len
); /* server->client cipher */
1624 for (i
= 0; i
< lenof(ciphers
); i
++) {
1625 if (in_commasep_string(ciphers
[i
]->name
, str
, len
)) {
1626 sccipher_tobe
= ciphers
[i
];
1630 ssh2_pkt_getstring(&str
, &len
); /* client->server mac */
1631 for (i
= 0; i
< lenof(macs
); i
++) {
1632 if (in_commasep_string(macs
[i
]->name
, str
, len
)) {
1633 csmac_tobe
= macs
[i
];
1637 ssh2_pkt_getstring(&str
, &len
); /* server->client mac */
1638 for (i
= 0; i
< lenof(macs
); i
++) {
1639 if (in_commasep_string(macs
[i
]->name
, str
, len
)) {
1640 scmac_tobe
= macs
[i
];
1644 ssh2_pkt_getstring(&str
, &len
); /* client->server compression */
1645 for (i
= 0; i
< lenof(compressions
); i
++) {
1646 if (in_commasep_string(compressions
[i
]->name
, str
, len
)) {
1647 cscomp_tobe
= compressions
[i
];
1651 ssh2_pkt_getstring(&str
, &len
); /* server->client compression */
1652 for (i
= 0; i
< lenof(compressions
); i
++) {
1653 if (in_commasep_string(compressions
[i
]->name
, str
, len
)) {
1654 sccomp_tobe
= compressions
[i
];
1660 * Currently we only support Diffie-Hellman and DSS, so let's
1661 * bomb out if those aren't selected.
1663 if (kex
!= &ssh_diffiehellman
|| hostkey
!= &ssh_dss
)
1664 fatalbox("internal fault: chaos in SSH 2 transport layer");
1667 * Now we begin the fun. Generate and send e for Diffie-Hellman.
1670 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT
);
1675 if (pktin
.type
!= SSH2_MSG_KEXDH_REPLY
) {
1676 fatalbox("expected key exchange packet from server");
1678 ssh2_pkt_getstring(&hostkeydata
, &hostkeylen
);
1679 f
= ssh2_pkt_getmp();
1680 ssh2_pkt_getstring(&sigdata
, &siglen
);
1684 sha_string(&exhash
, hostkeydata
, hostkeylen
);
1685 sha_mpint(&exhash
, e
);
1686 sha_mpint(&exhash
, f
);
1687 sha_mpint(&exhash
, K
);
1688 SHA_Final(&exhash
, exchange_hash
);
1691 debug(("Exchange hash is:\r\n"));
1692 for (i
= 0; i
< 20; i
++)
1693 debug((" %02x", exchange_hash
[i
]));
1697 hostkey
->setkey(hostkeydata
, hostkeylen
);
1698 if (!hostkey
->verifysig(sigdata
, siglen
, exchange_hash
, 20))
1699 fatalbox("Server failed host key check");
1702 * Expect SSH2_MSG_NEWKEYS from server.
1705 if (pktin
.type
!= SSH2_MSG_NEWKEYS
)
1706 fatalbox("expected new-keys packet from server");
1709 * Authenticate remote host: verify host key. (We've already
1710 * checked the signature of the exchange hash.)
1712 keystr
= hostkey
->fmtkey();
1713 verify_ssh_host_key(savedhost
, keystr
);
1717 * Send SSH2_MSG_NEWKEYS.
1719 ssh2_pkt_init(SSH2_MSG_NEWKEYS
);
1723 * Create and initialise session keys.
1725 cscipher
= cscipher_tobe
;
1726 sccipher
= sccipher_tobe
;
1729 cscomp
= cscomp_tobe
;
1730 sccomp
= sccomp_tobe
;
1732 * Set IVs after keys.
1734 ssh2_mkkey(K
, exchange_hash
, 'C', keyspace
); cscipher
->setcskey(keyspace
);
1735 ssh2_mkkey(K
, exchange_hash
, 'D', keyspace
); cscipher
->setsckey(keyspace
);
1736 ssh2_mkkey(K
, exchange_hash
, 'A', keyspace
); cscipher
->setcsiv(keyspace
);
1737 ssh2_mkkey(K
, exchange_hash
, 'B', keyspace
); sccipher
->setsciv(keyspace
);
1738 ssh2_mkkey(K
, exchange_hash
, 'E', keyspace
); csmac
->setcskey(keyspace
);
1739 ssh2_mkkey(K
, exchange_hash
, 'F', keyspace
); scmac
->setsckey(keyspace
);
1742 * Now we're encrypting. Begin returning 1 to the protocol main
1743 * function so that other things can run on top of the
1744 * transport. If we ever see a KEXINIT, we must go back to the
1749 } while (!(ispkt
&& pktin
.type
== SSH2_MSG_KEXINIT
));
1750 goto begin_key_exchange
;
1756 * SSH2: remote identifier for the main session channel.
1758 static unsigned long ssh_remote_channel
;
1761 * Handle the SSH2 userauth and connection layers.
1763 static void do_ssh2_authconn(unsigned char *in
, int inlen
, int ispkt
)
1765 static unsigned long remote_winsize
;
1766 static unsigned long remote_maxpkt
;
1771 * Request userauth protocol, and await a response to it.
1773 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
1774 ssh2_pkt_addstring("ssh-userauth");
1776 crWaitUntilV(ispkt
);
1777 if (pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
)
1778 fatalbox("Server refused user authentication protocol");
1781 * FIXME: currently we support only password authentication.
1782 * (This places us technically in violation of the SSH2 spec.
1783 * We must fix this.)
1787 * Get a username and a password.
1789 static char username
[100];
1790 static char password
[100];
1794 if ((flags
& FLAG_CONNECTION
) && !*cfg
.username
) {
1795 c_write("login as: ", 10);
1797 crWaitUntilV(!ispkt
);
1798 while (inlen
--) switch (c
= *in
++) {
1805 c_write("\b \b", 3);
1811 c_write("\b \b", 3);
1820 if (((c
>= ' ' && c
<= '~') ||
1821 ((unsigned char)c
>= 160)) && pos
< 40) {
1822 username
[pos
++] = c
;
1829 username
[strcspn(username
, "\n\r")] = '\0';
1832 strncpy(username
, cfg
.username
, 99);
1833 username
[99] = '\0';
1834 if (flags
& FLAG_VERBOSE
) {
1835 sprintf(stuff
, "Using username \"%s\".\r\n", username
);
1836 c_write(stuff
, strlen(stuff
));
1840 if (!(flags
& FLAG_WINDOWED
)) {
1842 sprintf(prompt
, "%s@%s's password: ", cfg
.username
, savedhost
);
1843 if (!ssh_get_password(prompt
, password
, sizeof(password
))) {
1845 * get_password failed to get a password (for
1846 * example because one was supplied on the command
1847 * line which has already failed to work).
1850 logevent("No more passwords to try");
1851 ssh_state
= SSH_STATE_CLOSED
;
1855 c_write("password: ", 10);
1859 crWaitUntilV(!ispkt
);
1860 while (inlen
--) switch (c
= *in
++) {
1877 if (((c
>= ' ' && c
<= '~') ||
1878 ((unsigned char)c
>= 160)) && pos
< 40)
1879 password
[pos
++] = c
;
1886 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
1887 ssh2_pkt_addstring(username
);
1888 ssh2_pkt_addstring("ssh-connection"); /* service requested */
1889 ssh2_pkt_addstring("password");
1890 ssh2_pkt_addbool(FALSE
);
1891 ssh2_pkt_addstring(password
);
1894 crWaitUntilV(ispkt
);
1895 if (pktin
.type
!= SSH2_MSG_USERAUTH_SUCCESS
) {
1896 c_write("Access denied\r\n", 15);
1897 logevent("Authentication refused");
1903 * Now we're authenticated for the connection protocol. The
1904 * connection protocol will automatically have started at this
1905 * point; there's no need to send SERVICE_REQUEST.
1909 * So now create a channel with a session in it.
1911 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
1912 ssh2_pkt_addstring("session");
1913 ssh2_pkt_adduint32(100); /* as good as any */
1914 ssh2_pkt_adduint32(0xFFFFFFFFUL
); /* very big window which we ignore */
1915 ssh2_pkt_adduint32(0xFFFFFFFFUL
); /* very big max pkt size */
1917 crWaitUntilV(ispkt
);
1918 if (pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
1919 fatalbox("Server refused to open a session");
1920 /* FIXME: error data comes back in FAILURE packet */
1922 if (ssh2_pkt_getuint32() != 100) {
1923 fatalbox("Server's channel confirmation cited wrong channel");
1925 ssh_remote_channel
= ssh2_pkt_getuint32();
1926 remote_winsize
= ssh2_pkt_getuint32();
1927 remote_maxpkt
= ssh2_pkt_getuint32();
1928 logevent("Opened channel for session");
1931 * Now allocate a pty for the session.
1933 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
1934 ssh2_pkt_adduint32(ssh_remote_channel
); /* recipient channel */
1935 ssh2_pkt_addstring("pty-req");
1936 ssh2_pkt_addbool(1); /* want reply */
1937 ssh2_pkt_addstring(cfg
.termtype
);
1938 ssh2_pkt_adduint32(cols
);
1939 ssh2_pkt_adduint32(rows
);
1940 ssh2_pkt_adduint32(0); /* pixel width */
1941 ssh2_pkt_adduint32(0); /* pixel height */
1942 ssh2_pkt_addstring_start();
1943 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
1946 do { /* FIXME: pay attention to these */
1947 crWaitUntilV(ispkt
);
1948 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
1950 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
1951 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
1952 fatalbox("Server got confused by pty request");
1954 c_write("Server refused to allocate pty\r\n", 32);
1956 logevent("Allocated pty");
1962 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
1963 ssh2_pkt_adduint32(ssh_remote_channel
); /* recipient channel */
1964 ssh2_pkt_addstring("shell");
1965 ssh2_pkt_addbool(1); /* want reply */
1967 do { /* FIXME: pay attention to these */
1968 crWaitUntilV(ispkt
);
1969 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
1970 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
1971 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
1972 fatalbox("Server got confused by shell request");
1974 fatalbox("Server refused to start a shell");
1976 logevent("Started a shell");
1986 if (pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
1987 pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
1990 if (ssh2_pkt_getuint32() != 100)
1991 continue; /* wrong channel */
1992 if (pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
1993 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR
)
1994 continue; /* extended but not stderr */
1995 ssh2_pkt_getstring(&data
, &length
);
1997 c_write(data
, length
);
1998 } else if (pktin
.type
== SSH2_MSG_DISCONNECT
) {
1999 ssh_state
= SSH_STATE_CLOSED
;
2000 logevent("Received disconnect request");
2001 } else if (pktin
.type
== SSH2_MSG_CHANNEL_REQUEST
) {
2002 continue; /* exit status et al; ignore (FIXME?) */
2003 } else if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
2004 continue; /* ignore for now (FIXME!) */
2006 fatalbox("Strange packet received: type %d", pktin
.type
);
2009 /* FIXME: for now, ignore window size */
2010 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA
);
2011 ssh2_pkt_adduint32(ssh_remote_channel
);
2012 ssh2_pkt_addstring_start();
2013 ssh2_pkt_addstring_data(in
, inlen
);
2022 * Handle the top-level SSH2 protocol.
2024 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
)
2026 if (do_ssh2_transport(in
, inlen
, ispkt
) == 0)
2028 do_ssh2_authconn(in
, inlen
, ispkt
);
2032 * Called to set up the connection. Will arrange for WM_NETEVENT
2033 * messages to be passed to the specified window, whose window
2034 * procedure should then call telnet_msg().
2036 * Returns an error message, or NULL on success.
2038 static char *ssh_init (HWND hwnd
, char *host
, int port
, char **realhost
) {
2042 if(crypto_startup() == 0)
2043 return "Microsoft high encryption pack not installed!";
2046 p
= connect_to_host(host
, port
, realhost
);
2051 return "Protocol initialisation error";
2053 if (hwnd
&& WSAAsyncSelect (s
, hwnd
, WM_NETEVENT
, FD_READ
| FD_CLOSE
) == SOCKET_ERROR
)
2054 switch (WSAGetLastError()) {
2055 case WSAENETDOWN
: return "Network is down";
2056 default: return "WSAAsyncSelect(): unknown error";
2063 * Process a WM_NETEVENT message. Will return 0 if the connection
2064 * has closed, or <0 for a socket error.
2066 static int ssh_msg (WPARAM wParam
, LPARAM lParam
) {
2071 * Because reading less than the whole of the available pending
2072 * data can generate an FD_READ event, we need to allow for the
2073 * possibility that FD_READ may arrive with FD_CLOSE already in
2074 * the queue; so it's possible that we can get here even with s
2075 * invalid. If so, we return 1 and don't worry about it.
2077 if (s
== INVALID_SOCKET
)
2080 if (WSAGETSELECTERROR(lParam
) != 0)
2081 return -WSAGETSELECTERROR(lParam
);
2083 switch (WSAGETSELECTEVENT(lParam
)) {
2086 ret
= recv(s
, buf
, sizeof(buf
), 0);
2087 if (ret
< 0 && WSAGetLastError() == WSAEWOULDBLOCK
)
2089 if (ret
< 0) /* any _other_ error */
2090 return -10000-WSAGetLastError();
2095 ssh_gotdata (buf
, ret
);
2096 if (ssh_state
== SSH_STATE_CLOSED
) {
2103 return 1; /* shouldn't happen, but WTF */
2107 * Called to send data down the Telnet connection.
2109 static void ssh_send (char *buf
, int len
) {
2110 if (s
== INVALID_SOCKET
)
2113 ssh_protocol(buf
, len
, 0);
2117 * Called to set the size of the window from Telnet's POV.
2119 static void ssh_size(void) {
2120 switch (ssh_state
) {
2121 case SSH_STATE_BEFORE_SIZE
:
2122 case SSH_STATE_CLOSED
:
2123 break; /* do nothing */
2124 case SSH_STATE_INTERMED
:
2125 size_needed
= TRUE
; /* buffer for later */
2127 case SSH_STATE_SESSION
:
2129 send_packet(SSH1_CMSG_WINDOW_SIZE
,
2130 PKT_INT
, rows
, PKT_INT
, cols
,
2131 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
2137 * Send Telnet special codes. TS_EOF is useful for `plink', so you
2138 * can send an EOF and collect resulting output (e.g. `plink
2141 static void ssh_special (Telnet_Special code
) {
2142 if (code
== TS_EOF
) {
2143 if (ssh_version
= 1) {
2144 send_packet(SSH1_CMSG_EOF
, PKT_END
);
2146 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF
);
2147 ssh2_pkt_adduint32(ssh_remote_channel
);
2157 * Read and decrypt one incoming SSH packet.
2158 * (only used by pSCP)
2160 static void get_packet(void)
2162 unsigned char buf
[4096], *p
;
2169 while ((to_read
= s_rdpkt(&p
, &len
)) > 0) {
2170 if (to_read
> sizeof(buf
)) to_read
= sizeof(buf
);
2171 len
= s_read(buf
, to_read
);
2172 if (len
!= to_read
) {
2184 * Receive a block of data over the SSH link. Block until
2185 * all data is available. Return nr of bytes read (0 if lost connection).
2186 * (only used by pSCP)
2188 int ssh_scp_recv(unsigned char *buf
, int len
)
2190 static int pending_input_len
= 0;
2191 static unsigned char *pending_input_ptr
;
2194 if (pending_input_len
>= to_read
) {
2195 memcpy(buf
, pending_input_ptr
, to_read
);
2196 pending_input_ptr
+= to_read
;
2197 pending_input_len
-= to_read
;
2201 if (pending_input_len
> 0) {
2202 memcpy(buf
, pending_input_ptr
, pending_input_len
);
2203 buf
+= pending_input_len
;
2204 to_read
-= pending_input_len
;
2205 pending_input_len
= 0;
2208 if (s
== INVALID_SOCKET
)
2210 while (to_read
> 0) {
2212 if (s
== INVALID_SOCKET
)
2214 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
) {
2215 int plen
= GET_32BIT(pktin
.body
);
2216 if (plen
<= to_read
) {
2217 memcpy(buf
, pktin
.body
+ 4, plen
);
2221 memcpy(buf
, pktin
.body
+ 4, to_read
);
2222 pending_input_len
= plen
- to_read
;
2223 pending_input_ptr
= pktin
.body
+ 4 + to_read
;
2226 } else if (pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
2227 int plen
= GET_32BIT(pktin
.body
);
2228 fwrite(pktin
.body
+ 4, plen
, 1, stderr
);
2229 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
2230 logevent("Received disconnect request");
2231 } else if (pktin
.type
== SSH1_SMSG_SUCCESS
||
2232 pktin
.type
== SSH1_SMSG_FAILURE
) {
2234 } else if (pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
2236 sprintf(logbuf
, "Remote exit status: %d", GET_32BIT(pktin
.body
));
2238 send_packet(SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
2239 logevent("Closing connection");
2243 fatalbox("Strange packet received: type %d", pktin
.type
);
2251 * Send a block of data over the SSH link.
2252 * Block until all data is sent.
2253 * (only used by pSCP)
2255 void ssh_scp_send(unsigned char *buf
, int len
)
2257 if (s
== INVALID_SOCKET
)
2259 send_packet(SSH1_CMSG_STDIN_DATA
,
2260 PKT_INT
, len
, PKT_DATA
, buf
, len
, PKT_END
);
2264 * Send an EOF notification to the server.
2265 * (only used by pSCP)
2267 void ssh_scp_send_eof(void)
2269 if (s
== INVALID_SOCKET
)
2271 send_packet(SSH1_CMSG_EOF
, PKT_END
);
2275 * Set up the connection, login on the remote host and
2276 * start execution of a command.
2277 * Returns an error message, or NULL on success.
2278 * (only used by pSCP)
2280 char *ssh_scp_init(char *host
, int port
, char *cmd
, char **realhost
)
2285 if (crypto_startup() == 0)
2286 return "Microsoft high encryption pack not installed!";
2289 p
= connect_to_host(host
, port
, realhost
);
2296 return "Protocol initialisation error";
2298 /* Exchange keys and login */
2301 if (s
== INVALID_SOCKET
)
2302 return "Connection closed by remote host";
2303 } while (!do_ssh1_login(NULL
, 0, 1));
2305 if (ssh_state
== SSH_STATE_CLOSED
) {
2308 return "Session initialisation error";
2311 /* Execute command */
2312 sprintf(buf
, "Sending command: %.100s", cmd
);
2314 send_packet(SSH1_CMSG_EXEC_CMD
, PKT_STR
, cmd
, PKT_END
);
2319 static SOCKET
ssh_socket(void) { return s
; }
2321 static int ssh_sendok(void) { return ssh_send_ok
; }
2323 Backend ssh_backend
= {