18 #define logevent(s) { logevent(s); \
19 if (IS_SCP && (scp_flags & SCP_VERBOSE) != 0) \
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
;
164 int (*ssh_get_password
)(const char *prompt
, char *str
, int maxlen
) = NULL
;
166 static char *savedhost
;
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);
183 fatalbox("Lost connection while sending");
190 static int s_read (char *buf
, int len
) {
193 int i
= recv (s
, buf
, len
, 0);
197 len
-= i
, buf
+= i
, ret
+= i
;
204 static void c_write (char *buf
, int len
) {
206 if (len
> 0 && buf
[len
-1] == '\n') len
--;
207 if (len
> 0 && buf
[len
-1] == '\r') len
--;
208 if (len
> 0) { fwrite(buf
, len
, 1, stderr
); fputc('\n', stderr
); }
224 static struct Packet pktin
= { 0, 0, NULL
, NULL
, 0 };
225 static struct Packet pktout
= { 0, 0, NULL
, NULL
, 0 };
227 static void (*ssh_protocol
)(unsigned char *in
, int inlen
, int ispkt
);
228 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
);
229 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
);
230 static void ssh_size(void);
232 static int (*s_rdpkt
)(unsigned char **data
, int *datalen
);
235 * Collect incoming data in the incoming packet buffer.
236 * Decipher and verify the packet when it is completely read.
237 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
238 * Update the *data and *datalen variables.
239 * Return the additional nr of bytes needed, or 0 when
240 * a complete packet is available.
242 static int ssh1_rdpkt(unsigned char **data
, int *datalen
)
244 static long len
, pad
, biglen
, to_read
;
245 static unsigned long realcrc
, gotcrc
;
246 static unsigned char *p
;
256 for (i
= len
= 0; i
< 4; i
++) {
257 while ((*datalen
) == 0)
259 len
= (len
<< 8) + **data
;
260 (*data
)++, (*datalen
)--;
264 if (len
== 0x52656d6f) { /* "Remo"te server has closed ... */
265 len
= 0x300; /* big enough to carry to end */
271 pktin
.length
= len
- 5;
273 if (pktin
.maxlen
< biglen
) {
274 pktin
.maxlen
= biglen
;
275 pktin
.data
= (pktin
.data
== NULL ?
malloc(biglen
+APIEXTRA
) :
276 realloc(pktin
.data
, biglen
+APIEXTRA
));
278 fatalbox("Out of memory");
283 while (to_read
> 0) {
286 while ((*datalen
) == 0)
288 if (chunk
> (*datalen
))
290 memcpy(p
, *data
, chunk
);
298 cipher
->decrypt(pktin
.data
, biglen
);
300 pktin
.type
= pktin
.data
[pad
];
301 pktin
.body
= pktin
.data
+ pad
+ 1;
303 realcrc
= crc32(pktin
.data
, biglen
-4);
304 gotcrc
= GET_32BIT(pktin
.data
+biglen
-4);
305 if (gotcrc
!= realcrc
) {
306 fatalbox("Incorrect CRC received on packet");
309 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
310 pktin
.type
== SSH1_SMSG_STDERR_DATA
||
311 pktin
.type
== SSH1_MSG_DEBUG
||
312 pktin
.type
== SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
313 long strlen
= GET_32BIT(pktin
.body
);
314 if (strlen
+ 4 != pktin
.length
)
315 fatalbox("Received data packet with bogus string length");
318 if (pktin
.type
== SSH1_MSG_DEBUG
) {
319 /* log debug message */
321 int strlen
= GET_32BIT(pktin
.body
);
322 strcpy(buf
, "Remote: ");
323 if (strlen
> 70) strlen
= 70;
324 memcpy(buf
+8, pktin
.body
+4, strlen
);
325 buf
[8+strlen
] = '\0';
328 } else if (pktin
.type
== SSH1_MSG_IGNORE
) {
336 static int ssh2_rdpkt(unsigned char **data
, int *datalen
)
338 static long len
, pad
, payload
, packetlen
, maclen
;
340 static int cipherblk
;
341 static unsigned long incoming_sequence
= 0;
351 cipherblk
= cipher
->blksize
;
357 if (pktin
.maxlen
< cipherblk
) {
358 pktin
.maxlen
= cipherblk
;
359 pktin
.data
= (pktin
.data
== NULL ?
malloc(cipherblk
+APIEXTRA
) :
360 realloc(pktin
.data
, cipherblk
+APIEXTRA
));
362 fatalbox("Out of memory");
366 * Acquire and decrypt the first block of the packet. This will
367 * contain the length and padding details.
369 for (i
= len
= 0; i
< cipherblk
; i
++) {
370 while ((*datalen
) == 0)
371 crReturn(cipherblk
-i
);
372 pktin
.data
[i
] = *(*data
)++;
376 if (!memcmp(pktin
.data
, "Remo", 4)) {/* "Remo"te server has closed ... */
381 sccipher
->decrypt(pktin
.data
, cipherblk
);
384 * Now get the length and padding figures.
386 len
= GET_32BIT(pktin
.data
);
390 * This enables us to deduce the payload length.
392 payload
= len
- pad
- 1;
394 pktin
.length
= payload
+ 5;
397 * So now we can work out the total packet length.
400 maclen
= scmac ? scmac
->len
: 0;
403 * Adjust memory allocation if packet is too big.
405 if (pktin
.maxlen
< packetlen
) {
406 pktin
.maxlen
= packetlen
;
407 pktin
.data
= (pktin
.data
== NULL ?
malloc(packetlen
+APIEXTRA
) :
408 realloc(pktin
.data
, packetlen
+APIEXTRA
));
410 fatalbox("Out of memory");
414 * Read and decrypt the remainder of the packet.
416 for (i
= cipherblk
; i
< packetlen
+ maclen
; i
++) {
417 while ((*datalen
) == 0)
418 crReturn(packetlen
+ maclen
- i
);
419 pktin
.data
[i
] = *(*data
)++;
422 /* Decrypt everything _except_ the MAC. */
424 sccipher
->decrypt(pktin
.data
+ cipherblk
, packetlen
- cipherblk
);
427 debug(("Got packet len=%d pad=%d\r\n", len
, pad
));
428 for (i
= 0; i
< packetlen
; i
++)
429 debug((" %02x", (unsigned char)pktin
.data
[i
]));
436 if (scmac
&& !scmac
->verify(pktin
.data
, len
+4, incoming_sequence
))
437 fatalbox("Incorrect MAC received on packet");
438 incoming_sequence
++; /* whether or not we MACed */
441 pktin
.type
= pktin
.data
[5];
443 if (pktin
.type
== SSH2_MSG_IGNORE
|| pktin
.type
== SSH2_MSG_DEBUG
)
444 goto next_packet
; /* FIXME: print DEBUG message */
449 static void ssh_gotdata(unsigned char *data
, int datalen
)
451 while (datalen
> 0) {
452 if ( s_rdpkt(&data
, &datalen
) == 0 ) {
453 ssh_protocol(NULL
, 0, 1);
454 if (ssh_state
== SSH_STATE_CLOSED
) {
462 static void s_wrpkt_start(int type
, int len
) {
465 len
+= 5; /* type and CRC */
469 pktout
.length
= len
-5;
470 if (pktout
.maxlen
< biglen
) {
471 pktout
.maxlen
= biglen
;
473 /* Allocate enough buffer space for extra block
474 * for MS CryptEncrypt() */
475 pktout
.data
= (pktout
.data
== NULL ?
malloc(biglen
+12) :
476 realloc(pktout
.data
, biglen
+12));
478 pktout
.data
= (pktout
.data
== NULL ?
malloc(biglen
+4) :
479 realloc(pktout
.data
, biglen
+4));
482 fatalbox("Out of memory");
486 pktout
.body
= pktout
.data
+4+pad
+1;
489 static void s_wrpkt(void) {
490 int pad
, len
, biglen
, i
;
493 len
= pktout
.length
+ 5; /* type and CRC */
497 pktout
.body
[-1] = pktout
.type
;
498 for (i
=0; i
<pad
; i
++)
499 pktout
.data
[i
+4] = random_byte();
500 crc
= crc32(pktout
.data
+4, biglen
-4);
501 PUT_32BIT(pktout
.data
+biglen
, crc
);
502 PUT_32BIT(pktout
.data
, len
);
505 cipher
->encrypt(pktout
.data
+4, biglen
);
507 s_write(pktout
.data
, biglen
+4);
511 * Construct a packet with the specified contents and
512 * send it to the server.
514 static void send_packet(int pkttype
, ...)
517 unsigned char *p
, *argp
, argchar
;
518 unsigned long argint
;
519 int pktlen
, argtype
, arglen
;
524 va_start(args
, pkttype
);
525 while ((argtype
= va_arg(args
, int)) != PKT_END
) {
528 (void) va_arg(args
, int);
532 (void) va_arg(args
, char);
536 (void) va_arg(args
, unsigned char *);
537 arglen
= va_arg(args
, int);
541 argp
= va_arg(args
, unsigned char *);
542 arglen
= strlen(argp
);
543 pktlen
+= 4 + arglen
;
546 bn
= va_arg(args
, Bignum
);
548 while ( i
> 0 && (bn
[i
/16+1] >> (i
%16)) == 0 )
550 pktlen
+= 2 + (i
+7)/8;
558 s_wrpkt_start(pkttype
, pktlen
);
561 va_start(args
, pkttype
);
562 while ((argtype
= va_arg(args
, int)) != PKT_END
) {
565 argint
= va_arg(args
, int);
566 PUT_32BIT(p
, argint
);
570 argchar
= va_arg(args
, unsigned char);
575 argp
= va_arg(args
, unsigned char *);
576 arglen
= va_arg(args
, int);
577 memcpy(p
, argp
, arglen
);
581 argp
= va_arg(args
, unsigned char *);
582 arglen
= strlen(argp
);
583 PUT_32BIT(p
, arglen
);
584 memcpy(p
+ 4, argp
, arglen
);
588 bn
= va_arg(args
, Bignum
);
590 while ( i
> 0 && (bn
[i
/16+1] >> (i
%16)) == 0 )
592 *p
++ = (i
>> 8) & 0xFF;
597 *p
++ = bn
[i
/2+1] >> 8;
599 *p
++ = bn
[i
/2+1] & 0xFF;
611 * Connect to specified host and port.
612 * Returns an error message, or NULL on success.
613 * Also places the canonical host name into `realhost'.
615 static char *connect_to_host(char *host
, int port
, char **realhost
)
625 savedhost
= malloc(1+strlen(host
));
627 fatalbox("Out of memory");
628 strcpy(savedhost
, host
);
631 port
= 22; /* default ssh port */
643 if ( (a
= inet_addr(host
)) == (unsigned long) INADDR_NONE
) {
644 if ( (h
= gethostbyname(host
)) == NULL
)
645 switch (WSAGetLastError()) {
646 case WSAENETDOWN
: return "Network is down";
647 case WSAHOST_NOT_FOUND
: case WSANO_DATA
:
648 return "Host does not exist";
649 case WSATRY_AGAIN
: return "Host not found";
650 default: return "gethostbyname: unknown error";
652 memcpy (&a
, h
->h_addr
, sizeof(a
));
653 *realhost
= h
->h_name
;
664 s
= socket(AF_INET
, SOCK_STREAM
, 0);
665 if (s
== INVALID_SOCKET
)
666 switch (WSAGetLastError()) {
667 case WSAENETDOWN
: return "Network is down";
668 case WSAEAFNOSUPPORT
: return "TCP/IP support not present";
669 default: return "socket(): unknown error";
673 * Bind to local address.
675 addr
.sin_family
= AF_INET
;
676 addr
.sin_addr
.s_addr
= htonl(INADDR_ANY
);
677 addr
.sin_port
= htons(0);
678 if (bind (s
, (struct sockaddr
*)&addr
, sizeof(addr
)) == SOCKET_ERROR
)
679 switch (WSAGetLastError()) {
680 case WSAENETDOWN
: return "Network is down";
681 default: return "bind(): unknown error";
685 * Connect to remote address.
687 addr
.sin_addr
.s_addr
= htonl(a
);
688 addr
.sin_port
= htons((short)port
);
689 if (connect (s
, (struct sockaddr
*)&addr
, sizeof(addr
)) == SOCKET_ERROR
)
690 switch (WSAGetLastError()) {
691 case WSAENETDOWN
: return "Network is down";
692 case WSAECONNREFUSED
: return "Connection refused";
693 case WSAENETUNREACH
: return "Network is unreachable";
694 case WSAEHOSTUNREACH
: return "No route to host";
695 default: return "connect(): unknown error";
699 send(s
, "connect ", 8, 0);
700 send(s
, FWhost
, strlen(FWhost
), 0);
703 sprintf(buf
, " %d\n", FWport
);
704 send (s
, buf
, strlen(buf
), 0);
711 static int ssh_versioncmp(char *a
, char *b
) {
713 unsigned long av
, bv
;
715 av
= strtoul(a
, &ae
, 10);
716 bv
= strtoul(b
, &be
, 10);
717 if (av
!= bv
) return (av
< bv ?
-1 : +1);
718 if (*ae
== '.') ae
++;
719 if (*be
== '.') be
++;
720 av
= strtoul(ae
, &ae
, 10);
721 bv
= strtoul(be
, &be
, 10);
722 if (av
!= bv
) return (av
< bv ?
-1 : +1);
728 * Utility routine for putting an SSH-protocol `string' into a SHA
732 void sha_string(SHA_State
*s
, void *str
, int len
) {
733 unsigned char lenblk
[4];
735 PUT_32BIT(lenblk
, len
);
736 if (!fp
) fp
= fopen("h:\\statham\\windows\\putty\\data","wb");
737 fwrite(lenblk
, 4, 1, fp
);
738 SHA_Bytes(s
, lenblk
, 4);
739 fwrite(str
, len
, 1, fp
);
741 SHA_Bytes(s
, str
, len
);
745 * SSH2 packet construction functions.
747 void ssh2_pkt_adddata(void *data
, int len
) {
748 pktout
.length
+= len
;
749 if (pktout
.maxlen
< pktout
.length
) {
750 pktout
.maxlen
= pktout
.length
+ 256;
751 pktout
.data
= (pktout
.data
== NULL ?
malloc(pktout
.maxlen
+APIEXTRA
) :
752 realloc(pktout
.data
, pktout
.maxlen
+APIEXTRA
));
754 fatalbox("Out of memory");
756 memcpy(pktout
.data
+pktout
.length
-len
, data
, len
);
758 void ssh2_pkt_addbyte(unsigned char byte
) {
759 ssh2_pkt_adddata(&byte
, 1);
761 void ssh2_pkt_init(int pkt_type
) {
763 ssh2_pkt_addbyte((unsigned char)pkt_type
);
765 void ssh2_pkt_addbool(unsigned char value
) {
766 ssh2_pkt_adddata(&value
, 1);
768 void ssh2_pkt_adduint32(unsigned long value
) {
771 ssh2_pkt_adddata(x
, 4);
773 void ssh2_pkt_addstring_start(void) {
774 ssh2_pkt_adduint32(0);
775 pktout
.savedpos
= pktout
.length
;
777 void ssh2_pkt_addstring_str(char *data
) {
778 ssh2_pkt_adddata(data
, strlen(data
));
779 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
780 pktout
.length
- pktout
.savedpos
);
782 void ssh2_pkt_addstring_data(char *data
, int len
) {
783 ssh2_pkt_adddata(data
, len
);
784 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
785 pktout
.length
- pktout
.savedpos
);
787 void ssh2_pkt_addstring(char *data
) {
788 ssh2_pkt_addstring_start();
789 ssh2_pkt_addstring_str(data
);
791 char *ssh2_mpint_fmt(Bignum b
, int *len
) {
794 p
= malloc(n
* 2 + 1);
796 fatalbox("out of memory");
798 for (i
= 0; i
< n
; i
++) {
799 p
[i
*2+1] = (b
[n
-i
] >> 8) & 0xFF;
800 p
[i
*2+2] = (b
[n
-i
] ) & 0xFF;
803 while (p
[i
] == 0 && (p
[i
+1] & 0x80) == 0)
805 memmove(p
, p
+i
, n
*2+1-i
);
809 void ssh2_pkt_addmp(Bignum b
) {
812 p
= ssh2_mpint_fmt(b
, &len
);
813 ssh2_pkt_addstring_start();
814 ssh2_pkt_addstring_data(p
, len
);
817 void ssh2_pkt_send(void) {
818 int cipherblk
, maclen
, padding
, i
;
819 static unsigned long outgoing_sequence
= 0;
822 * Add padding. At least four bytes, and must also bring total
823 * length (minus MAC) up to a multiple of the block size.
825 cipherblk
= cipher ? cipher
->blksize
: 8; /* block size */
826 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
828 padding
+= (cipherblk
- (pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
829 pktout
.data
[4] = padding
;
830 for (i
= 0; i
< padding
; i
++)
831 pktout
.data
[pktout
.length
+ i
] = random_byte();
832 PUT_32BIT(pktout
.data
, pktout
.length
+ padding
- 4);
834 csmac
->generate(pktout
.data
, pktout
.length
+ padding
,
836 outgoing_sequence
++; /* whether or not we MACed */
839 debug(("Sending packet len=%d\r\n", pktout
.length
+padding
));
840 for (i
= 0; i
< pktout
.length
+padding
; i
++)
841 debug((" %02x", (unsigned char)pktout
.data
[i
]));
846 cscipher
->encrypt(pktout
.data
, pktout
.length
+ padding
);
847 maclen
= csmac ? csmac
->len
: 0;
849 s_write(pktout
.data
, pktout
.length
+ padding
+ maclen
);
853 void bndebug(char *string
, Bignum b
) {
856 p
= ssh2_mpint_fmt(b
, &len
);
857 debug(("%s", string
));
858 for (i
= 0; i
< len
; i
++)
859 debug((" %02x", p
[i
]));
865 void sha_mpint(SHA_State
*s
, Bignum b
) {
868 p
= ssh2_mpint_fmt(b
, &len
);
869 sha_string(s
, p
, len
);
874 * SSH2 packet decode functions.
876 unsigned long ssh2_pkt_getuint32(void) {
878 if (pktin
.length
- pktin
.savedpos
< 4)
879 return 0; /* arrgh, no way to decline (FIXME?) */
880 value
= GET_32BIT(pktin
.data
+pktin
.savedpos
);
884 void ssh2_pkt_getstring(char **p
, int *length
) {
886 if (pktin
.length
- pktin
.savedpos
< 4)
888 *length
= GET_32BIT(pktin
.data
+pktin
.savedpos
);
890 if (pktin
.length
- pktin
.savedpos
< *length
)
892 *p
= pktin
.data
+pktin
.savedpos
;
893 pktin
.savedpos
+= *length
;
895 Bignum
ssh2_pkt_getmp(void) {
900 ssh2_pkt_getstring(&p
, &length
);
904 fatalbox("internal error: Can't handle negative mpints");
905 b
= newbn((length
+1)/2);
906 for (i
= 0; i
< length
; i
++) {
909 b
[j
/2+1] |= ((unsigned char)p
[i
]) << 8;
911 b
[j
/2+1] |= ((unsigned char)p
[i
]);
916 static int do_ssh_init(void) {
920 char vlog
[sizeof(vstring
)+20];
925 while (s_read(&c
, 1) == 1) {
926 if (c
== 'S' && i
< 2) i
++;
927 else if (c
== 'S' && i
== 2) i
= 2;
928 else if (c
== 'H' && i
== 2) break;
932 if (s_read(&c
,1) != 1 || c
!= 'S') return 0;
933 if (s_read(&c
,1) != 1 || c
!= 'S') return 0;
934 if (s_read(&c
,1) != 1 || c
!= 'H') return 0;
936 strcpy(vstring
, "SSH-");
938 if (s_read(&c
,1) != 1 || c
!= '-') return 0;
941 if (s_read(&c
,1) != 1)
943 if (vsp
< vstring
+sizeof(vstring
)-1)
949 } else if (i
< sizeof(version
)-1)
957 sprintf(vlog
, "Server version: %s", vstring
);
958 vlog
[strcspn(vlog
, "\r\n")] = '\0';
961 if (ssh_versioncmp(version
, "2.0" /* FIXME: "1.99" */ ) >= 0) {
963 * This is a v2 server. Begin v2 protocol.
965 char *verstring
= "SSH-2.0-PuTTY";
968 * Hash our version string and their version string.
970 sha_string(&exhash
, verstring
, strlen(verstring
));
971 sha_string(&exhash
, vstring
, strcspn(vstring
, "\r\n"));
972 sprintf(vstring
, "%s\n", verstring
);
973 sprintf(vlog
, "We claim version: %s", verstring
);
975 logevent("Using SSH protocol version 2");
976 s_write(vstring
, strlen(vstring
));
977 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
;
991 s_rdpkt
= ssh1_rdpkt
;
997 * Handle the key exchange and user authentication phases.
999 static int do_ssh1_login(unsigned char *in
, int inlen
, int ispkt
)
1002 unsigned char *rsabuf
, *keystr1
, *keystr2
;
1003 unsigned char cookie
[8];
1004 struct RSAKey servkey
, hostkey
;
1005 struct MD5Context md5c
;
1006 static unsigned long supported_ciphers_mask
, supported_auths_mask
;
1007 static int tried_publickey
;
1008 static unsigned char session_id
[16];
1013 if (!ispkt
) crWaitUntil(ispkt
);
1015 if (pktin
.type
!= SSH1_SMSG_PUBLIC_KEY
)
1016 fatalbox("Public key packet not received");
1018 logevent("Received public keys");
1020 memcpy(cookie
, pktin
.body
, 8);
1022 i
= makekey(pktin
.body
+8, &servkey
, &keystr1
, 0);
1023 j
= makekey(pktin
.body
+8+i
, &hostkey
, &keystr2
, 0);
1026 * Hash the host key and print the hash in the log box. Just as
1027 * a last resort in case the registry's host key checking is
1028 * compromised, we'll allow the user some ability to verify
1032 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
1033 MD5Final(session_id
, &md5c
);
1037 logevent("Host key MD5 is:");
1038 strcpy(logmsg
, " ");
1039 for (i
= 0; i
< 16; i
++)
1040 sprintf(logmsg
+strlen(logmsg
), "%02x", session_id
[i
]);
1044 supported_ciphers_mask
= GET_32BIT(pktin
.body
+12+i
+j
);
1045 supported_auths_mask
= GET_32BIT(pktin
.body
+16+i
+j
);
1048 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
1049 MD5Update(&md5c
, keystr1
, servkey
.bytes
);
1050 MD5Update(&md5c
, pktin
.body
, 8);
1051 MD5Final(session_id
, &md5c
);
1053 for (i
=0; i
<32; i
++)
1054 session_key
[i
] = random_byte();
1056 len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
1058 rsabuf
= malloc(len
);
1060 fatalbox("Out of memory");
1063 * Verify the host key.
1067 * First format the key into a string.
1069 int len
= rsastr_len(&hostkey
);
1070 char *keystr
= malloc(len
);
1072 fatalbox("Out of memory");
1073 rsastr_fmt(keystr
, &hostkey
);
1074 verify_ssh_host_key(savedhost
, keystr
);
1078 for (i
=0; i
<32; i
++) {
1079 rsabuf
[i
] = session_key
[i
];
1081 rsabuf
[i
] ^= session_id
[i
];
1084 if (hostkey
.bytes
> servkey
.bytes
) {
1085 rsaencrypt(rsabuf
, 32, &servkey
);
1086 rsaencrypt(rsabuf
, servkey
.bytes
, &hostkey
);
1088 rsaencrypt(rsabuf
, 32, &hostkey
);
1089 rsaencrypt(rsabuf
, hostkey
.bytes
, &servkey
);
1092 logevent("Encrypted session key");
1094 cipher_type
= cfg
.cipher
== CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH
:
1095 cfg
.cipher
== CIPHER_DES ? SSH_CIPHER_DES
:
1097 if ((supported_ciphers_mask
& (1 << cipher_type
)) == 0) {
1098 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1099 cipher_type
= SSH_CIPHER_3DES
;
1101 switch (cipher_type
) {
1102 case SSH_CIPHER_3DES
: logevent("Using 3DES encryption"); break;
1103 case SSH_CIPHER_DES
: logevent("Using single-DES encryption"); break;
1104 case SSH_CIPHER_BLOWFISH
: logevent("Using Blowfish encryption"); break;
1107 send_packet(SSH1_CMSG_SESSION_KEY
,
1108 PKT_CHAR
, cipher_type
,
1109 PKT_DATA
, cookie
, 8,
1110 PKT_CHAR
, (len
*8) >> 8, PKT_CHAR
, (len
*8) & 0xFF,
1111 PKT_DATA
, rsabuf
, len
,
1115 logevent("Trying to enable encryption...");
1119 cipher
= cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish
:
1120 cipher_type
== SSH_CIPHER_DES ?
&ssh_des
:
1122 cipher
->sesskey(session_key
);
1126 if (pktin
.type
!= SSH1_SMSG_SUCCESS
)
1127 fatalbox("Encryption not successfully enabled");
1129 logevent("Successfully started encryption");
1133 static char username
[100];
1136 if (!IS_SCP
&& !*cfg
.username
) {
1137 c_write("login as: ", 10);
1139 crWaitUntil(!ispkt
);
1140 while (inlen
--) switch (c
= *in
++) {
1147 c_write("\b \b", 3);
1153 c_write("\b \b", 3);
1162 if (((c
>= ' ' && c
<= '~') ||
1163 ((unsigned char)c
>= 160)) && pos
< 40) {
1164 username
[pos
++] = c
;
1171 username
[strcspn(username
, "\n\r")] = '\0';
1174 strncpy(username
, cfg
.username
, 99);
1175 username
[99] = '\0';
1177 sprintf(stuff
, "Sent username \"%s\".\r\n", username
);
1178 c_write(stuff
, strlen(stuff
));
1182 send_packet(SSH1_CMSG_USER
, PKT_STR
, username
, PKT_END
);
1184 char userlog
[20+sizeof(username
)];
1185 sprintf(userlog
, "Sent username \"%s\"", username
);
1192 tried_publickey
= 0;
1194 while (pktin
.type
== SSH1_SMSG_FAILURE
) {
1195 static char password
[100];
1198 static int pwpkt_type
;
1200 * Show password prompt, having first obtained it via a TIS
1201 * exchange if we're doing TIS authentication.
1203 pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
1204 if (*cfg
.keyfile
&& !tried_publickey
)
1205 pwpkt_type
= SSH1_CMSG_AUTH_RSA
;
1207 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
&& IS_SCP
) {
1209 sprintf(prompt
, "%s@%s's password: ", cfg
.username
, savedhost
);
1210 if (!ssh_get_password(prompt
, password
, sizeof(password
))) {
1212 * get_password failed to get a password (for
1213 * example because one was supplied on the command
1214 * line which has already failed to work).
1217 logevent("No more passwords to try");
1218 ssh_state
= SSH_STATE_CLOSED
;
1223 if (pktin
.type
== SSH1_SMSG_FAILURE
&&
1225 (supported_auths_mask
& (1<<SSH1_AUTH_TIS
))) {
1226 pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
1227 logevent("Requested TIS authentication");
1228 send_packet(SSH1_CMSG_AUTH_TIS
, PKT_END
);
1230 if (pktin
.type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
1231 logevent("TIS authentication declined");
1232 c_write("TIS authentication refused.\r\n", 29);
1234 int challengelen
= ((pktin
.body
[0] << 24) |
1235 (pktin
.body
[1] << 16) |
1236 (pktin
.body
[2] << 8) |
1238 logevent("Received TIS challenge");
1239 c_write(pktin
.body
+4, challengelen
);
1242 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
)
1243 c_write("password: ", 10);
1244 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
1245 c_write("Trying public key authentication.\r\n", 35);
1246 if (!rsakey_encrypted(cfg
.keyfile
)) {
1247 c_write("No passphrase required.\r\n", 25);
1250 c_write("passphrase: ", 12);
1255 crWaitUntil(!ispkt
);
1256 while (inlen
--) switch (c
= *in
++) {
1273 if (((c
>= ' ' && c
<= '~') ||
1274 ((unsigned char)c
>= 160)) && pos
< sizeof(password
))
1275 password
[pos
++] = c
;
1284 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
1286 * Try public key authentication with the specified
1289 static struct RSAKey pubkey
;
1290 static Bignum challenge
, response
;
1292 static unsigned char buffer
[32];
1294 tried_publickey
= 1;
1295 i
= loadrsakey(cfg
.keyfile
, &pubkey
, password
);
1297 c_write("Couldn't load public key from ", 30);
1298 c_write(cfg
.keyfile
, strlen(cfg
.keyfile
));
1299 c_write(".\r\n", 3);
1300 continue; /* go and try password */
1303 c_write("Wrong passphrase.\r\n", 19);
1304 tried_publickey
= 0;
1305 continue; /* try again */
1309 * Send a public key attempt.
1311 send_packet(SSH1_CMSG_AUTH_RSA
,
1312 PKT_BIGNUM
, pubkey
.modulus
, PKT_END
);
1315 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
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 c_write("Failed to authenticate with our public key.\r\n", 45);
1341 continue; /* go and try password */
1342 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1343 fatalbox("Bizarre response to RSA authentication response");
1346 break; /* we're through! */
1348 send_packet(pwpkt_type
, PKT_STR
, password
, PKT_END
);
1350 logevent("Sent password");
1351 memset(password
, 0, strlen(password
));
1353 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1354 c_write("Access denied\r\n", 15);
1355 logevent("Authentication refused");
1356 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
1357 logevent("Received disconnect request");
1358 ssh_state
= SSH_STATE_CLOSED
;
1360 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1361 fatalbox("Strange packet received, type %d", pktin
.type
);
1365 logevent("Authentication successful");
1370 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
) {
1375 while (!do_ssh1_login(in
, inlen
, ispkt
)) {
1378 if (ssh_state
== SSH_STATE_CLOSED
)
1382 send_packet(SSH1_CMSG_REQUEST_PTY
,
1383 PKT_STR
, cfg
.termtype
,
1384 PKT_INT
, rows
, PKT_INT
, cols
,
1385 PKT_INT
, 0, PKT_INT
, 0,
1388 ssh_state
= SSH_STATE_INTERMED
;
1389 do { crReturnV
; } while (!ispkt
);
1390 if (pktin
.type
!= SSH1_SMSG_SUCCESS
&& pktin
.type
!= SSH1_SMSG_FAILURE
) {
1391 fatalbox("Protocol confusion");
1392 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1393 c_write("Server refused to allocate pty\r\n", 32);
1395 logevent("Allocated pty");
1398 send_packet(SSH1_CMSG_EXEC_SHELL
, PKT_END
);
1399 logevent("Started session");
1401 ssh_state
= SSH_STATE_SESSION
;
1408 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
1409 pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
1410 long len
= GET_32BIT(pktin
.body
);
1411 c_write(pktin
.body
+4, len
);
1412 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
1413 ssh_state
= SSH_STATE_CLOSED
;
1414 logevent("Received disconnect request");
1415 } else if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
1416 /* may be from EXEC_SHELL on some servers */
1417 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1418 /* may be from EXEC_SHELL on some servers
1419 * if no pty is available or in other odd cases. Ignore */
1420 } else if (pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
1421 send_packet(SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
1423 fatalbox("Strange packet received: type %d", pktin
.type
);
1426 send_packet(SSH1_CMSG_STDIN_DATA
,
1427 PKT_INT
, inlen
, PKT_DATA
, in
, inlen
, PKT_END
);
1435 * Utility routine for decoding comma-separated strings in KEXINIT.
1437 int in_commasep_string(char *needle
, char *haystack
, int haylen
) {
1438 int needlen
= strlen(needle
);
1441 * Is it at the start of the string?
1443 if (haylen
>= needlen
&& /* haystack is long enough */
1444 !memcmp(needle
, haystack
, needlen
) && /* initial match */
1445 (haylen
== needlen
|| haystack
[needlen
] == ',')
1446 /* either , or EOS follows */
1450 * If not, search for the next comma and resume after that.
1451 * If no comma found, terminate.
1453 while (haylen
> 0 && *haystack
!= ',')
1454 haylen
--, haystack
++;
1457 haylen
--, haystack
++; /* skip over comma itself */
1462 * SSH2 key creation method.
1464 void ssh2_mkkey(Bignum K
, char *H
, char chr
, char *keyspace
) {
1466 /* First 20 bytes. */
1469 SHA_Bytes(&s
, H
, 20);
1470 SHA_Bytes(&s
, &chr
, 1);
1471 SHA_Bytes(&s
, H
, 20);
1472 SHA_Final(&s
, keyspace
);
1473 /* Next 20 bytes. */
1476 SHA_Bytes(&s
, H
, 20);
1477 SHA_Bytes(&s
, keyspace
, 20);
1478 SHA_Final(&s
, keyspace
+20);
1482 * Handle the SSH2 transport layer.
1484 static int do_ssh2_transport(unsigned char *in
, int inlen
, int ispkt
)
1488 static Bignum e
, f
, K
;
1489 static struct ssh_cipher
*cscipher_tobe
= NULL
;
1490 static struct ssh_cipher
*sccipher_tobe
= NULL
;
1491 static struct ssh_mac
*csmac_tobe
= NULL
;
1492 static struct ssh_mac
*scmac_tobe
= NULL
;
1493 static struct ssh_compress
*cscomp_tobe
= NULL
;
1494 static struct ssh_compress
*sccomp_tobe
= NULL
;
1495 static char *hostkeydata
, *sigdata
, *keystr
;
1496 static int hostkeylen
, siglen
;
1497 static unsigned char exchange_hash
[20];
1498 static unsigned char keyspace
[40];
1505 * Construct and send our key exchange packet.
1507 ssh2_pkt_init(SSH2_MSG_KEXINIT
);
1508 for (i
= 0; i
< 16; i
++)
1509 ssh2_pkt_addbyte((unsigned char)random_byte());
1510 /* List key exchange algorithms. */
1511 ssh2_pkt_addstring_start();
1512 for (i
= 0; i
< lenof(kex_algs
); i
++) {
1513 ssh2_pkt_addstring_str(kex_algs
[i
]->name
);
1514 if (i
< lenof(kex_algs
)-1)
1515 ssh2_pkt_addstring_str(",");
1517 /* List server host key algorithms. */
1518 ssh2_pkt_addstring_start();
1519 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
1520 ssh2_pkt_addstring_str(hostkey_algs
[i
]->name
);
1521 if (i
< lenof(hostkey_algs
)-1)
1522 ssh2_pkt_addstring_str(",");
1524 /* List client->server encryption algorithms. */
1525 ssh2_pkt_addstring_start();
1526 for (i
= 0; i
< lenof(ciphers
); i
++) {
1527 ssh2_pkt_addstring_str(ciphers
[i
]->name
);
1528 if (i
< lenof(ciphers
)-1)
1529 ssh2_pkt_addstring_str(",");
1531 /* List server->client encryption algorithms. */
1532 ssh2_pkt_addstring_start();
1533 for (i
= 0; i
< lenof(ciphers
); i
++) {
1534 ssh2_pkt_addstring_str(ciphers
[i
]->name
);
1535 if (i
< lenof(ciphers
)-1)
1536 ssh2_pkt_addstring_str(",");
1538 /* List client->server MAC algorithms. */
1539 ssh2_pkt_addstring_start();
1540 for (i
= 0; i
< lenof(macs
); i
++) {
1541 ssh2_pkt_addstring_str(macs
[i
]->name
);
1542 if (i
< lenof(macs
)-1)
1543 ssh2_pkt_addstring_str(",");
1545 /* List server->client MAC algorithms. */
1546 ssh2_pkt_addstring_start();
1547 for (i
= 0; i
< lenof(macs
); i
++) {
1548 ssh2_pkt_addstring_str(macs
[i
]->name
);
1549 if (i
< lenof(macs
)-1)
1550 ssh2_pkt_addstring_str(",");
1552 /* List client->server compression algorithms. */
1553 ssh2_pkt_addstring_start();
1554 for (i
= 0; i
< lenof(compressions
); i
++) {
1555 ssh2_pkt_addstring_str(compressions
[i
]->name
);
1556 if (i
< lenof(compressions
)-1)
1557 ssh2_pkt_addstring_str(",");
1559 /* List server->client compression algorithms. */
1560 ssh2_pkt_addstring_start();
1561 for (i
= 0; i
< lenof(compressions
); i
++) {
1562 ssh2_pkt_addstring_str(compressions
[i
]->name
);
1563 if (i
< lenof(compressions
)-1)
1564 ssh2_pkt_addstring_str(",");
1566 /* List client->server languages. Empty list. */
1567 ssh2_pkt_addstring_start();
1568 /* List server->client languages. Empty list. */
1569 ssh2_pkt_addstring_start();
1570 /* First KEX packet does _not_ follow, because we're not that brave. */
1571 ssh2_pkt_addbool(FALSE
);
1573 ssh2_pkt_adduint32(0);
1574 sha_string(&exhash
, pktout
.data
+5, pktout
.length
-5);
1577 if (!ispkt
) crWaitUntil(ispkt
);
1578 sha_string(&exhash
, pktin
.data
+5, pktin
.length
-5);
1581 * Now examine the other side's KEXINIT to see what we're up
1584 if (pktin
.type
!= SSH2_MSG_KEXINIT
) {
1585 fatalbox("expected key exchange packet from server");
1587 kex
= NULL
; hostkey
= NULL
; cscipher_tobe
= NULL
; sccipher_tobe
= NULL
;
1588 csmac_tobe
= NULL
; scmac_tobe
= NULL
; cscomp_tobe
= NULL
; sccomp_tobe
= NULL
;
1589 pktin
.savedpos
+= 16; /* skip garbage cookie */
1590 ssh2_pkt_getstring(&str
, &len
); /* key exchange algorithms */
1591 for (i
= 0; i
< lenof(kex_algs
); i
++) {
1592 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
1597 ssh2_pkt_getstring(&str
, &len
); /* host key algorithms */
1598 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
1599 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
1600 hostkey
= hostkey_algs
[i
];
1604 ssh2_pkt_getstring(&str
, &len
); /* client->server cipher */
1605 for (i
= 0; i
< lenof(ciphers
); i
++) {
1606 if (in_commasep_string(ciphers
[i
]->name
, str
, len
)) {
1607 cscipher_tobe
= ciphers
[i
];
1611 ssh2_pkt_getstring(&str
, &len
); /* server->client cipher */
1612 for (i
= 0; i
< lenof(ciphers
); i
++) {
1613 if (in_commasep_string(ciphers
[i
]->name
, str
, len
)) {
1614 sccipher_tobe
= ciphers
[i
];
1618 ssh2_pkt_getstring(&str
, &len
); /* client->server mac */
1619 for (i
= 0; i
< lenof(macs
); i
++) {
1620 if (in_commasep_string(macs
[i
]->name
, str
, len
)) {
1621 csmac_tobe
= macs
[i
];
1625 ssh2_pkt_getstring(&str
, &len
); /* server->client mac */
1626 for (i
= 0; i
< lenof(macs
); i
++) {
1627 if (in_commasep_string(macs
[i
]->name
, str
, len
)) {
1628 scmac_tobe
= macs
[i
];
1632 ssh2_pkt_getstring(&str
, &len
); /* client->server compression */
1633 for (i
= 0; i
< lenof(compressions
); i
++) {
1634 if (in_commasep_string(compressions
[i
]->name
, str
, len
)) {
1635 cscomp_tobe
= compressions
[i
];
1639 ssh2_pkt_getstring(&str
, &len
); /* server->client compression */
1640 for (i
= 0; i
< lenof(compressions
); i
++) {
1641 if (in_commasep_string(compressions
[i
]->name
, str
, len
)) {
1642 sccomp_tobe
= compressions
[i
];
1648 * Currently we only support Diffie-Hellman and DSS, so let's
1649 * bomb out if those aren't selected.
1651 if (kex
!= &ssh_diffiehellman
|| hostkey
!= &ssh_dss
)
1652 fatalbox("internal fault: chaos in SSH 2 transport layer");
1655 * Now we begin the fun. Generate and send e for Diffie-Hellman.
1658 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT
);
1663 if (pktin
.type
!= SSH2_MSG_KEXDH_REPLY
) {
1664 fatalbox("expected key exchange packet from server");
1666 ssh2_pkt_getstring(&hostkeydata
, &hostkeylen
);
1667 f
= ssh2_pkt_getmp();
1668 ssh2_pkt_getstring(&sigdata
, &siglen
);
1672 sha_string(&exhash
, hostkeydata
, hostkeylen
);
1673 sha_mpint(&exhash
, e
);
1674 sha_mpint(&exhash
, f
);
1675 sha_mpint(&exhash
, K
);
1676 SHA_Final(&exhash
, exchange_hash
);
1679 debug(("Exchange hash is:\r\n"));
1680 for (i
= 0; i
< 20; i
++)
1681 debug((" %02x", exchange_hash
[i
]));
1685 hostkey
->setkey(hostkeydata
, hostkeylen
);
1686 if (!hostkey
->verifysig(sigdata
, siglen
, exchange_hash
, 20))
1687 fatalbox("Server failed host key check");
1690 * Expect SSH2_MSG_NEWKEYS from server.
1693 if (pktin
.type
!= SSH2_MSG_NEWKEYS
)
1694 fatalbox("expected new-keys packet from server");
1697 * Authenticate remote host: verify host key. (We've already
1698 * checked the signature of the exchange hash.)
1700 keystr
= hostkey
->fmtkey();
1701 verify_ssh_host_key(savedhost
, keystr
);
1705 * Send SSH2_MSG_NEWKEYS.
1707 ssh2_pkt_init(SSH2_MSG_NEWKEYS
);
1711 * Create and initialise session keys.
1713 cscipher
= cscipher_tobe
;
1714 sccipher
= sccipher_tobe
;
1717 cscomp
= cscomp_tobe
;
1718 sccomp
= sccomp_tobe
;
1720 * Set IVs after keys.
1722 ssh2_mkkey(K
, exchange_hash
, 'C', keyspace
); cscipher
->setcskey(keyspace
);
1723 ssh2_mkkey(K
, exchange_hash
, 'D', keyspace
); cscipher
->setsckey(keyspace
);
1724 ssh2_mkkey(K
, exchange_hash
, 'A', keyspace
); cscipher
->setcsiv(keyspace
);
1725 ssh2_mkkey(K
, exchange_hash
, 'B', keyspace
); sccipher
->setsciv(keyspace
);
1726 ssh2_mkkey(K
, exchange_hash
, 'E', keyspace
); csmac
->setcskey(keyspace
);
1727 ssh2_mkkey(K
, exchange_hash
, 'F', keyspace
); scmac
->setsckey(keyspace
);
1730 * Now we're encrypting. Begin returning 1 to the protocol main
1731 * function so that other things can run on top of the
1732 * transport. If we ever see a KEXINIT, we must go back to the
1737 } while (!(ispkt
&& pktin
.type
== SSH2_MSG_KEXINIT
));
1738 goto begin_key_exchange
;
1744 * Handle the SSH2 userauth and connection layers.
1746 static void do_ssh2_authconn(unsigned char *in
, int inlen
, int ispkt
)
1748 static unsigned long their_channel
;
1749 static unsigned long remote_winsize
;
1750 static unsigned long remote_maxpkt
;
1755 * Request userauth protocol, and await a response to it.
1757 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
1758 ssh2_pkt_addstring("ssh-userauth");
1760 crWaitUntilV(ispkt
);
1761 if (pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
)
1762 fatalbox("Server refused user authentication protocol");
1765 * FIXME: currently we support only password authentication.
1766 * (This places us technically in violation of the SSH2 spec.
1767 * We must fix this.)
1771 * Get a username and a password.
1773 static char username
[100];
1774 static char password
[100];
1778 if (!IS_SCP
&& !*cfg
.username
) {
1779 c_write("login as: ", 10);
1781 crWaitUntilV(!ispkt
);
1782 while (inlen
--) switch (c
= *in
++) {
1789 c_write("\b \b", 3);
1795 c_write("\b \b", 3);
1804 if (((c
>= ' ' && c
<= '~') ||
1805 ((unsigned char)c
>= 160)) && pos
< 40) {
1806 username
[pos
++] = c
;
1813 username
[strcspn(username
, "\n\r")] = '\0';
1816 strncpy(username
, cfg
.username
, 99);
1817 username
[99] = '\0';
1819 sprintf(stuff
, "Using username \"%s\".\r\n", username
);
1820 c_write(stuff
, strlen(stuff
));
1826 sprintf(prompt
, "%s@%s's password: ", cfg
.username
, savedhost
);
1827 if (!ssh_get_password(prompt
, password
, sizeof(password
))) {
1829 * get_password failed to get a password (for
1830 * example because one was supplied on the command
1831 * line which has already failed to work).
1834 logevent("No more passwords to try");
1835 ssh_state
= SSH_STATE_CLOSED
;
1839 c_write("password: ", 10);
1843 crWaitUntilV(!ispkt
);
1844 while (inlen
--) switch (c
= *in
++) {
1861 if (((c
>= ' ' && c
<= '~') ||
1862 ((unsigned char)c
>= 160)) && pos
< 40)
1863 password
[pos
++] = c
;
1870 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
1871 ssh2_pkt_addstring(username
);
1872 ssh2_pkt_addstring("ssh-connection"); /* service requested */
1873 ssh2_pkt_addstring("password");
1874 ssh2_pkt_addbool(FALSE
);
1875 ssh2_pkt_addstring(password
);
1878 crWaitUntilV(ispkt
);
1879 if (pktin
.type
!= SSH2_MSG_USERAUTH_SUCCESS
) {
1880 c_write("Access denied\r\n", 15);
1881 logevent("Authentication refused");
1887 * Now we're authenticated for the connection protocol. The
1888 * connection protocol will automatically have started at this
1889 * point; there's no need to send SERVICE_REQUEST.
1893 * So now create a channel with a session in it.
1895 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
1896 ssh2_pkt_addstring("session");
1897 ssh2_pkt_adduint32(100); /* as good as any */
1898 ssh2_pkt_adduint32(0xFFFFFFFFUL
); /* very big window which we ignore */
1899 ssh2_pkt_adduint32(0xFFFFFFFFUL
); /* very big max pkt size */
1901 crWaitUntilV(ispkt
);
1902 if (pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
1903 fatalbox("Server refused to open a session");
1904 /* FIXME: error data comes back in FAILURE packet */
1906 if (ssh2_pkt_getuint32() != 100) {
1907 fatalbox("Server's channel confirmation cited wrong channel");
1909 their_channel
= ssh2_pkt_getuint32();
1910 remote_winsize
= ssh2_pkt_getuint32();
1911 remote_maxpkt
= ssh2_pkt_getuint32();
1912 logevent("Opened channel for session");
1915 * Now allocate a pty for the session.
1917 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
1918 ssh2_pkt_adduint32(their_channel
); /* recipient channel */
1919 ssh2_pkt_addstring("pty-req");
1920 ssh2_pkt_addbool(1); /* want reply */
1921 ssh2_pkt_addstring(cfg
.termtype
);
1922 ssh2_pkt_adduint32(cols
);
1923 ssh2_pkt_adduint32(rows
);
1924 ssh2_pkt_adduint32(0); /* pixel width */
1925 ssh2_pkt_adduint32(0); /* pixel height */
1926 ssh2_pkt_addstring_start();
1927 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
1930 do { /* FIXME: pay attention to these */
1931 crWaitUntilV(ispkt
);
1932 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
1934 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
1935 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
1936 fatalbox("Server got confused by pty request");
1938 c_write("Server refused to allocate pty\r\n", 32);
1940 logevent("Allocated pty");
1946 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
1947 ssh2_pkt_adduint32(their_channel
); /* recipient channel */
1948 ssh2_pkt_addstring("shell");
1949 ssh2_pkt_addbool(1); /* want reply */
1951 do { /* FIXME: pay attention to these */
1952 crWaitUntilV(ispkt
);
1953 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
1954 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
1955 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
1956 fatalbox("Server got confused by shell request");
1958 fatalbox("Server refused to start a shell");
1960 logevent("Started a shell");
1969 if (pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
1970 pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
1973 if (ssh2_pkt_getuint32() != 100)
1974 continue; /* wrong channel */
1975 if (pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
1976 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR
)
1977 continue; /* extended but not stderr */
1978 ssh2_pkt_getstring(&data
, &length
);
1980 c_write(data
, length
);
1981 } else if (pktin
.type
== SSH2_MSG_DISCONNECT
) {
1982 ssh_state
= SSH_STATE_CLOSED
;
1983 logevent("Received disconnect request");
1984 } else if (pktin
.type
== SSH2_MSG_CHANNEL_REQUEST
) {
1985 continue; /* exit status et al; ignore (FIXME?) */
1986 } else if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
1987 continue; /* ignore for now (FIXME!) */
1989 fatalbox("Strange packet received: type %d", pktin
.type
);
1992 /* FIXME: for now, ignore window size */
1993 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA
);
1994 ssh2_pkt_adduint32(their_channel
);
1995 ssh2_pkt_addstring_start();
1996 ssh2_pkt_addstring_data(in
, inlen
);
2005 * Handle the top-level SSH2 protocol.
2007 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
)
2009 if (do_ssh2_transport(in
, inlen
, ispkt
) == 0)
2011 do_ssh2_authconn(in
, inlen
, ispkt
);
2015 * Called to set up the connection. Will arrange for WM_NETEVENT
2016 * messages to be passed to the specified window, whose window
2017 * procedure should then call telnet_msg().
2019 * Returns an error message, or NULL on success.
2021 static char *ssh_init (HWND hwnd
, char *host
, int port
, char **realhost
) {
2025 if(crypto_startup() == 0)
2026 return "Microsoft high encryption pack not installed!";
2029 p
= connect_to_host(host
, port
, realhost
);
2034 return "Protocol initialisation error";
2036 if (WSAAsyncSelect (s
, hwnd
, WM_NETEVENT
, FD_READ
| FD_CLOSE
) == SOCKET_ERROR
)
2037 switch (WSAGetLastError()) {
2038 case WSAENETDOWN
: return "Network is down";
2039 default: return "WSAAsyncSelect(): unknown error";
2046 * Process a WM_NETEVENT message. Will return 0 if the connection
2047 * has closed, or <0 for a socket error.
2049 static int ssh_msg (WPARAM wParam
, LPARAM lParam
) {
2054 * Because reading less than the whole of the available pending
2055 * data can generate an FD_READ event, we need to allow for the
2056 * possibility that FD_READ may arrive with FD_CLOSE already in
2057 * the queue; so it's possible that we can get here even with s
2058 * invalid. If so, we return 1 and don't worry about it.
2060 if (s
== INVALID_SOCKET
)
2063 if (WSAGETSELECTERROR(lParam
) != 0)
2064 return -WSAGETSELECTERROR(lParam
);
2066 switch (WSAGETSELECTEVENT(lParam
)) {
2069 ret
= recv(s
, buf
, sizeof(buf
), 0);
2070 if (ret
< 0 && WSAGetLastError() == WSAEWOULDBLOCK
)
2072 if (ret
< 0) /* any _other_ error */
2073 return -10000-WSAGetLastError();
2078 ssh_gotdata (buf
, ret
);
2079 if (ssh_state
== SSH_STATE_CLOSED
) {
2086 return 1; /* shouldn't happen, but WTF */
2090 * Called to send data down the Telnet connection.
2092 static void ssh_send (char *buf
, int len
) {
2093 if (s
== INVALID_SOCKET
)
2096 ssh_protocol(buf
, len
, 0);
2100 * Called to set the size of the window from Telnet's POV.
2102 static void ssh_size(void) {
2103 switch (ssh_state
) {
2104 case SSH_STATE_BEFORE_SIZE
:
2105 case SSH_STATE_CLOSED
:
2106 break; /* do nothing */
2107 case SSH_STATE_INTERMED
:
2108 size_needed
= TRUE
; /* buffer for later */
2110 case SSH_STATE_SESSION
:
2112 send_packet(SSH1_CMSG_WINDOW_SIZE
,
2113 PKT_INT
, rows
, PKT_INT
, cols
,
2114 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
2120 * (Send Telnet special codes)
2122 static void ssh_special (Telnet_Special code
) {
2128 * Read and decrypt one incoming SSH packet.
2129 * (only used by pSCP)
2131 static void get_packet(void)
2133 unsigned char buf
[4096], *p
;
2142 while ((to_read
= s_rdpkt(&p
, &len
)) > 0) {
2143 if (to_read
> sizeof(buf
)) to_read
= sizeof(buf
);
2144 len
= s_read(buf
, to_read
);
2145 if (len
!= to_read
) {
2157 * Receive a block of data over the SSH link. Block until
2158 * all data is available. Return nr of bytes read (0 if lost connection).
2159 * (only used by pSCP)
2161 int ssh_scp_recv(unsigned char *buf
, int len
)
2163 static int pending_input_len
= 0;
2164 static unsigned char *pending_input_ptr
;
2169 if (pending_input_len
>= to_read
) {
2170 memcpy(buf
, pending_input_ptr
, to_read
);
2171 pending_input_ptr
+= to_read
;
2172 pending_input_len
-= to_read
;
2176 if (pending_input_len
> 0) {
2177 memcpy(buf
, pending_input_ptr
, pending_input_len
);
2178 buf
+= pending_input_len
;
2179 to_read
-= pending_input_len
;
2180 pending_input_len
= 0;
2183 if (s
== INVALID_SOCKET
)
2185 while (to_read
> 0) {
2187 if (s
== INVALID_SOCKET
)
2189 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
) {
2190 int plen
= GET_32BIT(pktin
.body
);
2191 if (plen
<= to_read
) {
2192 memcpy(buf
, pktin
.body
+ 4, plen
);
2196 memcpy(buf
, pktin
.body
+ 4, to_read
);
2197 pending_input_len
= plen
- to_read
;
2198 pending_input_ptr
= pktin
.body
+ 4 + to_read
;
2201 } else if (pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
2202 int plen
= GET_32BIT(pktin
.body
);
2203 fwrite(pktin
.body
+ 4, plen
, 1, stderr
);
2204 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
2205 logevent("Received disconnect request");
2206 } else if (pktin
.type
== SSH1_SMSG_SUCCESS
||
2207 pktin
.type
== SSH1_SMSG_FAILURE
) {
2209 } else if (pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
2211 sprintf(logbuf
, "Remote exit status: %d", GET_32BIT(pktin
.body
));
2213 send_packet(SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
2214 logevent("Closing connection");
2218 fatalbox("Strange packet received: type %d", pktin
.type
);
2226 * Send a block of data over the SSH link.
2227 * Block until all data is sent.
2228 * (only used by pSCP)
2230 void ssh_scp_send(unsigned char *buf
, int len
)
2233 if (s
== INVALID_SOCKET
)
2235 send_packet(SSH1_CMSG_STDIN_DATA
,
2236 PKT_INT
, len
, PKT_DATA
, buf
, len
, PKT_END
);
2240 * Send an EOF notification to the server.
2241 * (only used by pSCP)
2243 void ssh_scp_send_eof(void)
2246 if (s
== INVALID_SOCKET
)
2248 send_packet(SSH1_CMSG_EOF
, PKT_END
);
2252 * Set up the connection, login on the remote host and
2253 * start execution of a command.
2254 * Returns an error message, or NULL on success.
2255 * (only used by pSCP)
2257 char *ssh_scp_init(char *host
, int port
, char *cmd
, char **realhost
)
2264 if (crypto_startup() == 0)
2265 return "Microsoft high encryption pack not installed!";
2268 p
= connect_to_host(host
, port
, realhost
);
2275 return "Protocol initialisation error";
2277 /* Exchange keys and login */
2280 if (s
== INVALID_SOCKET
)
2281 return "Connection closed by remote host";
2282 } while (!do_ssh1_login(NULL
, 0, 1));
2284 if (ssh_state
== SSH_STATE_CLOSED
) {
2287 return "Session initialisation error";
2290 /* Execute command */
2291 sprintf(buf
, "Sending command: %.100s", cmd
);
2293 send_packet(SSH1_CMSG_EXEC_CMD
, PKT_STR
, cmd
, PKT_END
);
2299 Backend ssh_backend
= {