16 #define SSH_MSG_DISCONNECT 1
17 #define SSH_SMSG_PUBLIC_KEY 2
18 #define SSH_CMSG_SESSION_KEY 3
19 #define SSH_CMSG_USER 4
20 #define SSH_CMSG_AUTH_PASSWORD 9
21 #define SSH_CMSG_REQUEST_PTY 10
22 #define SSH_CMSG_EXEC_SHELL 12
23 #define SSH_CMSG_STDIN_DATA 16
24 #define SSH_SMSG_STDOUT_DATA 17
25 #define SSH_SMSG_STDERR_DATA 18
26 #define SSH_SMSG_SUCCESS 14
27 #define SSH_SMSG_FAILURE 15
28 #define SSH_SMSG_EXITSTATUS 20
29 #define SSH_MSG_IGNORE 32
30 #define SSH_CMSG_EXIT_CONFIRMATION 33
31 #define SSH_MSG_DEBUG 36
32 #define SSH_CMSG_AUTH_TIS 39
33 #define SSH_SMSG_AUTH_TIS_CHALLENGE 40
34 #define SSH_CMSG_AUTH_TIS_RESPONSE 41
36 #define SSH_AUTH_TIS 5
38 /* Coroutine mechanics for the sillier bits of the code */
39 #define crBegin1 static int crLine = 0;
40 #define crBegin2 switch(crLine) { case 0:;
41 #define crBegin crBegin1; crBegin2;
42 #define crFinish(z) } crLine = 0; return (z)
43 #define crFinishV } crLine = 0; return
46 crLine=__LINE__; return (z); case __LINE__:;\
50 crLine=__LINE__; return; case __LINE__:;\
52 #define crStop(z) do{ crLine = 0; return (z); }while(0)
53 #define crStopV do{ crLine = 0; return; }while(0)
62 static SOCKET s
= INVALID_SOCKET
;
64 static unsigned char session_key
[32];
65 static struct ssh_cipher
*cipher
= NULL
;
67 static char *savedhost
;
70 SSH_STATE_BEFORE_SIZE
,
74 } ssh_state
= SSH_STATE_BEFORE_SIZE
;
76 static int size_needed
= FALSE
;
78 static void s_write (char *buf
, int len
) {
80 int i
= send (s
, buf
, len
, 0);
86 static int s_read (char *buf
, int len
) {
89 int i
= recv (s
, buf
, len
, 0);
91 len
-= i
, buf
+= i
, ret
+= i
;
98 static void c_write (char *buf
, int len
) {
100 int new_head
= (inbuf_head
+ 1) & INBUF_MASK
;
101 if (new_head
!= inbuf_reap
) {
102 inbuf
[inbuf_head
] = *buf
++;
103 inbuf_head
= new_head
;
117 static struct Packet pktin
= { 0, 0, 0, NULL
, 0 };
118 static struct Packet pktout
= { 0, 0, 0, NULL
, 0 };
120 static void ssh_protocol(unsigned char *in
, int inlen
, int ispkt
);
121 static void ssh_size(void);
123 static void ssh_gotdata(unsigned char *data
, int datalen
) {
124 static long len
, biglen
, to_read
;
125 static unsigned char *p
;
130 for (i
= len
= 0; i
< 4; i
++) {
133 len
= (len
<< 8) + *data
;
138 if (len
== 0x52656d6f) { /* "Remo"te server has closed ... */
139 len
= 0x300; /* big enough to carry to end */
147 len
-= 5; /* type and CRC */
150 if (pktin
.maxlen
< biglen
) {
151 pktin
.maxlen
= biglen
;
152 pktin
.data
= (pktin
.data
== NULL ?
malloc(biglen
) :
153 realloc(pktin
.data
, biglen
));
155 fatalbox("Out of memory");
158 p
= pktin
.data
, to_read
= biglen
;
159 while (to_read
> 0) {
166 memcpy(p
, data
, chunk
);
174 cipher
->decrypt(pktin
.data
, biglen
);
176 pktin
.type
= pktin
.data
[pad
];
177 pktin
.body
= pktin
.data
+pad
+1;
179 if (pktin
.type
== SSH_MSG_DEBUG
) {
181 } else if (pktin
.type
== SSH_MSG_IGNORE
) {
184 ssh_protocol(NULL
, 0, 1);
189 static void s_wrpkt_start(int type
, int len
) {
192 len
+= 5; /* type and CRC */
196 pktout
.length
= len
-5;
197 if (pktout
.maxlen
< biglen
) {
198 pktout
.maxlen
= biglen
;
199 pktout
.data
= (pktout
.data
== NULL ?
malloc(biglen
+4) :
200 realloc(pktout
.data
, biglen
+4));
202 fatalbox("Out of memory");
206 pktout
.body
= pktout
.data
+4+pad
+1;
209 static void s_wrpkt(void) {
210 int pad
, len
, biglen
, i
;
213 len
= pktout
.length
+ 5; /* type and CRC */
217 pktout
.body
[-1] = pktout
.type
;
218 for (i
=0; i
<pad
; i
++)
219 pktout
.data
[i
+4] = random_byte();
220 crc
= crc32(pktout
.data
+4, biglen
-4);
222 pktout
.data
[biglen
+0] = (unsigned char) ((crc
>> 24) & 0xFF);
223 pktout
.data
[biglen
+1] = (unsigned char) ((crc
>> 16) & 0xFF);
224 pktout
.data
[biglen
+2] = (unsigned char) ((crc
>> 8) & 0xFF);
225 pktout
.data
[biglen
+3] = (unsigned char) (crc
& 0xFF);
227 pktout
.data
[0] = (len
>> 24) & 0xFF;
228 pktout
.data
[1] = (len
>> 16) & 0xFF;
229 pktout
.data
[2] = (len
>> 8) & 0xFF;
230 pktout
.data
[3] = len
& 0xFF;
233 cipher
->encrypt(pktout
.data
+4, biglen
);
235 s_write(pktout
.data
, biglen
+4);
238 static int ssh_versioncmp(char *a
, char *b
) {
240 unsigned long av
, bv
;
242 av
= strtoul(a
, &ae
, 10);
243 bv
= strtoul(b
, &be
, 10);
244 if (av
!= bv
) return (av
< bv ?
-1 : +1);
245 if (*ae
== '.') ae
++;
246 if (*be
== '.') be
++;
247 av
= strtoul(ae
, &ae
, 10);
248 bv
= strtoul(be
, &be
, 10);
249 if (av
!= bv
) return (av
< bv ?
-1 : +1);
253 static int do_ssh_init(void) {
257 char vlog
[sizeof(vstring
)+20];
262 while (s_read(&c
, 1) == 1) {
263 if (c
== 'S' && i
< 2) i
++;
264 else if (c
== 'S' && i
== 2) i
= 2;
265 else if (c
== 'H' && i
== 2) break;
269 if (s_read(&c
,1) != 1 || c
!= 'S') return 0;
270 if (s_read(&c
,1) != 1 || c
!= 'S') return 0;
271 if (s_read(&c
,1) != 1 || c
!= 'H') return 0;
273 strcpy(vstring
, "SSH-");
275 if (s_read(&c
,1) != 1 || c
!= '-') return 0;
278 if (s_read(&c
,1) != 1)
280 if (vsp
< vstring
+sizeof(vstring
)-1)
286 } else if (i
< sizeof(version
)-1)
294 sprintf(vlog
, "Server version: %s", vstring
);
295 vlog
[strcspn(vlog
, "\r\n")] = '\0';
298 sprintf(vstring
, "SSH-%s-PuTTY\n",
299 (ssh_versioncmp(version
, "1.5") <= 0 ? version
: "1.5"));
300 sprintf(vlog
, "We claim version: %s", vstring
);
301 vlog
[strcspn(vlog
, "\r\n")] = '\0';
303 s_write(vstring
, strlen(vstring
));
307 static void ssh_protocol(unsigned char *in
, int inlen
, int ispkt
) {
309 unsigned char session_id
[16];
310 unsigned char *rsabuf
, *keystr1
, *keystr2
;
311 unsigned char cookie
[8];
312 struct RSAKey servkey
, hostkey
;
313 struct MD5Context md5c
;
314 static unsigned long supported_ciphers_mask
, supported_auths_mask
;
317 extern struct ssh_cipher ssh_3des
;
318 extern struct ssh_cipher ssh_des
;
319 extern struct ssh_cipher ssh_blowfish
;
328 if (pktin
.type
!= SSH_SMSG_PUBLIC_KEY
)
329 fatalbox("Public key packet not received");
331 logevent("Received public keys");
333 memcpy(cookie
, pktin
.body
, 8);
335 i
= makekey(pktin
.body
+8, &servkey
, &keystr1
);
337 j
= makekey(pktin
.body
+8+i
, &hostkey
, &keystr2
);
340 * Hash the host key and print the hash in the log box. Just as
341 * a last resort in case the registry's host key checking is
342 * compromised, we'll allow the user some ability to verify
346 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
347 MD5Final(session_id
, &md5c
);
351 logevent("Host key MD5 is:");
353 for (i
= 0; i
< 16; i
++)
354 sprintf(logmsg
+strlen(logmsg
), "%02x", session_id
[i
]);
358 supported_ciphers_mask
= ((pktin
.body
[12+i
+j
] << 24) |
359 (pktin
.body
[13+i
+j
] << 16) |
360 (pktin
.body
[14+i
+j
] << 8) |
361 (pktin
.body
[15+i
+j
]));
363 supported_auths_mask
= ((pktin
.body
[16+i
+j
] << 24) |
364 (pktin
.body
[17+i
+j
] << 16) |
365 (pktin
.body
[18+i
+j
] << 8) |
366 (pktin
.body
[19+i
+j
]));
370 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
371 MD5Update(&md5c
, keystr1
, servkey
.bytes
);
372 MD5Update(&md5c
, pktin
.body
, 8);
374 MD5Final(session_id
, &md5c
);
377 session_key
[i
] = random_byte();
379 len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
381 rsabuf
= malloc(len
);
383 fatalbox("Out of memory");
385 verify_ssh_host_key(savedhost
, &hostkey
);
387 for (i
=0; i
<32; i
++) {
388 rsabuf
[i
] = session_key
[i
];
390 rsabuf
[i
] ^= session_id
[i
];
393 if (hostkey
.bytes
> servkey
.bytes
) {
394 rsaencrypt(rsabuf
, 32, &servkey
);
395 rsaencrypt(rsabuf
, servkey
.bytes
, &hostkey
);
397 rsaencrypt(rsabuf
, 32, &hostkey
);
398 rsaencrypt(rsabuf
, hostkey
.bytes
, &servkey
);
401 logevent("Encrypted session key");
403 cipher_type
= cfg
.cipher
== CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH
:
404 cfg
.cipher
== CIPHER_DES ? SSH_CIPHER_DES
:
406 if ((supported_ciphers_mask
& (1 << cipher_type
)) == 0) {
407 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
408 cipher_type
= SSH_CIPHER_3DES
;
410 switch (cipher_type
) {
411 case SSH_CIPHER_3DES
: logevent("Using 3DES encryption"); break;
412 case SSH_CIPHER_DES
: logevent("Using single-DES encryption"); break;
413 case SSH_CIPHER_BLOWFISH
: logevent("Using Blowfish encryption"); break;
416 s_wrpkt_start(SSH_CMSG_SESSION_KEY
, len
+15);
417 pktout
.body
[0] = cipher_type
;
418 memcpy(pktout
.body
+1, cookie
, 8);
419 pktout
.body
[9] = (len
*8) >> 8;
420 pktout
.body
[10] = (len
*8) & 0xFF;
421 memcpy(pktout
.body
+11, rsabuf
, len
);
422 pktout
.body
[len
+11] = pktout
.body
[len
+12] = 0; /* protocol flags */
423 pktout
.body
[len
+13] = pktout
.body
[len
+14] = 0;
425 logevent("Trying to enable encryption...");
429 cipher
= cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish
:
430 cipher_type
== SSH_CIPHER_DES ?
&ssh_des
:
432 cipher
->sesskey(session_key
);
434 do { crReturnV
; } while (!ispkt
);
436 if (pktin
.type
!= SSH_SMSG_SUCCESS
)
437 fatalbox("Encryption not successfully enabled");
439 logevent("Successfully started encryption");
443 static char username
[100];
446 if (!*cfg
.username
) {
447 c_write("login as: ", 10);
449 do { crReturnV
; } while (ispkt
);
450 while (inlen
--) switch (c
= *in
++) {
472 if (c
>= ' ' && c
<= '~' && pos
< 40) {
480 username
[strcspn(username
, "\n\r")] = '\0';
483 strncpy(username
, cfg
.username
, 99);
485 sprintf(stuff
, "Sent username \"%s\".\r\n", username
);
486 c_write(stuff
, strlen(stuff
));
488 s_wrpkt_start(SSH_CMSG_USER
, 4+strlen(username
));
490 char userlog
[20+sizeof(username
)];
491 sprintf(userlog
, "Sent username \"%s\"", username
);
494 pktout
.body
[0] = pktout
.body
[1] = pktout
.body
[2] = 0;
495 pktout
.body
[3] = strlen(username
);
496 memcpy(pktout
.body
+4, username
, strlen(username
));
500 do { crReturnV
; } while (!ispkt
);
502 while (pktin
.type
== SSH_SMSG_FAILURE
) {
503 static char password
[100];
506 static int pwpkt_type
;
509 * Show password prompt, having first obtained it via a TIS
510 * exchange if we're doing TIS authentication.
512 pwpkt_type
= SSH_CMSG_AUTH_PASSWORD
;
513 if (pktin
.type
== SSH_SMSG_FAILURE
&&
515 (supported_auths_mask
& (1<<SSH_AUTH_TIS
))) {
516 pwpkt_type
= SSH_CMSG_AUTH_TIS_RESPONSE
;
517 logevent("Requested TIS authentication");
518 s_wrpkt_start(SSH_CMSG_AUTH_TIS
, 0);
520 do { crReturnV
; } while (!ispkt
);
521 if (pktin
.type
!= SSH_SMSG_AUTH_TIS_CHALLENGE
) {
522 logevent("TIS authentication declined");
523 c_write("TIS authentication refused.\r\n", 29);
525 int challengelen
= ((pktin
.body
[0] << 24) |
526 (pktin
.body
[1] << 16) |
527 (pktin
.body
[2] << 8) |
529 logevent("Received TIS challenge");
530 c_write(pktin
.body
+4, challengelen
);
533 if (pwpkt_type
== SSH_CMSG_AUTH_PASSWORD
)
534 c_write("password: ", 10);
538 do { crReturnV
; } while (ispkt
);
539 while (inlen
--) switch (c
= *in
++) {
556 if (c
>= ' ' && c
<= '~' && pos
< 40)
562 s_wrpkt_start(pwpkt_type
, 4+strlen(password
));
563 pktout
.body
[0] = pktout
.body
[1] = pktout
.body
[2] = 0;
564 pktout
.body
[3] = strlen(password
);
565 memcpy(pktout
.body
+4, password
, strlen(password
));
567 logevent("Sent password");
568 memset(password
, 0, strlen(password
));
569 do { crReturnV
; } while (!ispkt
);
570 if (pktin
.type
== 15) {
571 c_write("Access denied\r\n", 15);
572 logevent("Authentication refused");
573 } else if (pktin
.type
!= 14) {
574 fatalbox("Strange packet received, type %d", pktin
.type
);
578 logevent("Authentication successful");
581 i
= strlen(cfg
.termtype
);
582 s_wrpkt_start(SSH_CMSG_REQUEST_PTY
, i
+5*4+1);
583 pktout
.body
[0] = (i
>> 24) & 0xFF;
584 pktout
.body
[1] = (i
>> 16) & 0xFF;
585 pktout
.body
[2] = (i
>> 8) & 0xFF;
586 pktout
.body
[3] = i
& 0xFF;
587 memcpy(pktout
.body
+4, cfg
.termtype
, i
);
589 pktout
.body
[i
++] = (rows
>> 24) & 0xFF;
590 pktout
.body
[i
++] = (rows
>> 16) & 0xFF;
591 pktout
.body
[i
++] = (rows
>> 8) & 0xFF;
592 pktout
.body
[i
++] = rows
& 0xFF;
593 pktout
.body
[i
++] = (cols
>> 24) & 0xFF;
594 pktout
.body
[i
++] = (cols
>> 16) & 0xFF;
595 pktout
.body
[i
++] = (cols
>> 8) & 0xFF;
596 pktout
.body
[i
++] = cols
& 0xFF;
597 memset(pktout
.body
+i
, 0, 9); /* 0 pixwidth, 0 pixheight, 0.b endofopt */
599 ssh_state
= SSH_STATE_INTERMED
;
600 do { crReturnV
; } while (!ispkt
);
601 if (pktin
.type
!= SSH_SMSG_SUCCESS
&& pktin
.type
!= SSH_SMSG_FAILURE
) {
602 fatalbox("Protocol confusion");
603 } else if (pktin
.type
== SSH_SMSG_FAILURE
) {
604 c_write("Server refused to allocate pty\r\n", 32);
606 logevent("Allocated pty");
609 s_wrpkt_start(SSH_CMSG_EXEC_SHELL
, 0);
611 logevent("Started session");
613 ssh_state
= SSH_STATE_SESSION
;
620 if (pktin
.type
== SSH_SMSG_STDOUT_DATA
||
621 pktin
.type
== SSH_SMSG_STDERR_DATA
) {
623 for (i
= 0; i
< 4; i
++)
624 len
= (len
<< 8) + pktin
.body
[i
];
625 c_write(pktin
.body
+4, len
);
626 } else if (pktin
.type
== SSH_MSG_DISCONNECT
) {
627 ssh_state
= SSH_STATE_CLOSED
;
628 logevent("Received disconnect request");
629 } else if (pktin
.type
== SSH_SMSG_SUCCESS
) {
630 /* may be from EXEC_SHELL on some servers */
631 } else if (pktin
.type
== SSH_SMSG_FAILURE
) {
632 /* may be from EXEC_SHELL on some servers
633 * if no pty is available or in other odd cases. Ignore */
634 } else if (pktin
.type
== SSH_SMSG_EXITSTATUS
) {
635 s_wrpkt_start(SSH_CMSG_EXIT_CONFIRMATION
, 0);
638 fatalbox("Strange packet received: type %d", pktin
.type
);
641 s_wrpkt_start(SSH_CMSG_STDIN_DATA
, 4+inlen
);
642 pktout
.body
[0] = (inlen
>> 24) & 0xFF;
643 pktout
.body
[1] = (inlen
>> 16) & 0xFF;
644 pktout
.body
[2] = (inlen
>> 8) & 0xFF;
645 pktout
.body
[3] = inlen
& 0xFF;
646 memcpy(pktout
.body
+4, in
, inlen
);
655 * Called to set up the connection. Will arrange for WM_NETEVENT
656 * messages to be passed to the specified window, whose window
657 * procedure should then call telnet_msg().
659 * Returns an error message, or NULL on success.
661 * Also places the canonical host name into `realhost'.
663 static char *ssh_init (HWND hwnd
, char *host
, int port
, char **realhost
) {
672 savedhost
= malloc(1+strlen(host
));
674 fatalbox("Out of memory");
675 strcpy(savedhost
, host
);
687 if ( (a
= inet_addr(host
)) == (unsigned long) INADDR_NONE
) {
688 if ( (h
= gethostbyname(host
)) == NULL
)
689 switch (WSAGetLastError()) {
690 case WSAENETDOWN
: return "Network is down";
691 case WSAHOST_NOT_FOUND
: case WSANO_DATA
:
692 return "Host does not exist";
693 case WSATRY_AGAIN
: return "Host not found";
694 default: return "gethostbyname: unknown error";
696 memcpy (&a
, h
->h_addr
, sizeof(a
));
697 *realhost
= h
->h_name
;
706 port
= 22; /* default ssh port */
711 s
= socket(AF_INET
, SOCK_STREAM
, 0);
712 if (s
== INVALID_SOCKET
)
713 switch (WSAGetLastError()) {
714 case WSAENETDOWN
: return "Network is down";
715 case WSAEAFNOSUPPORT
: return "TCP/IP support not present";
716 default: return "socket(): unknown error";
720 * Bind to local address.
722 addr
.sin_family
= AF_INET
;
723 addr
.sin_addr
.s_addr
= htonl(INADDR_ANY
);
724 addr
.sin_port
= htons(0);
725 if (bind (s
, (struct sockaddr
*)&addr
, sizeof(addr
)) == SOCKET_ERROR
)
726 switch (WSAGetLastError()) {
727 case WSAENETDOWN
: return "Network is down";
728 default: return "bind(): unknown error";
732 * Connect to remote address.
734 addr
.sin_addr
.s_addr
= htonl(a
);
735 addr
.sin_port
= htons((short)port
);
736 if (connect (s
, (struct sockaddr
*)&addr
, sizeof(addr
)) == SOCKET_ERROR
)
737 switch (WSAGetLastError()) {
738 case WSAENETDOWN
: return "Network is down";
739 case WSAECONNREFUSED
: return "Connection refused";
740 case WSAENETUNREACH
: return "Network is unreachable";
741 case WSAEHOSTUNREACH
: return "No route to host";
742 default: return "connect(): unknown error";
746 send(s
, "connect ", 8, 0);
747 send(s
, FWhost
, strlen(FWhost
), 0);
750 sprintf(buf
, " %d\n", FWport
);
751 send (s
, buf
, strlen(buf
), 0);
756 return "Protocol initialisation error";
758 if (WSAAsyncSelect (s
, hwnd
, WM_NETEVENT
, FD_READ
| FD_CLOSE
) == SOCKET_ERROR
)
759 switch (WSAGetLastError()) {
760 case WSAENETDOWN
: return "Network is down";
761 default: return "WSAAsyncSelect(): unknown error";
768 * Process a WM_NETEVENT message. Will return 0 if the connection
769 * has closed, or <0 for a socket error.
771 static int ssh_msg (WPARAM wParam
, LPARAM lParam
) {
775 if (s
== INVALID_SOCKET
) /* how the hell did we get here?! */
778 if (WSAGETSELECTERROR(lParam
) != 0)
779 return -WSAGETSELECTERROR(lParam
);
781 switch (WSAGETSELECTEVENT(lParam
)) {
783 ret
= recv(s
, buf
, sizeof(buf
), 0);
784 if (ret
< 0 && WSAGetLastError() == WSAEWOULDBLOCK
)
786 if (ret
< 0) /* any _other_ error */
787 return -10000-WSAGetLastError();
790 return 0; /* can't happen, in theory */
792 ssh_gotdata (buf
, ret
);
796 ssh_state
= SSH_STATE_CLOSED
;
799 return 1; /* shouldn't happen, but WTF */
803 * Called to send data down the Telnet connection.
805 static void ssh_send (char *buf
, int len
) {
806 if (s
== INVALID_SOCKET
)
809 ssh_protocol(buf
, len
, 0);
813 * Called to set the size of the window from Telnet's POV.
815 static void ssh_size(void) {
817 case SSH_STATE_BEFORE_SIZE
:
818 case SSH_STATE_CLOSED
:
819 break; /* do nothing */
820 case SSH_STATE_INTERMED
:
821 size_needed
= TRUE
; /* buffer for later */
823 case SSH_STATE_SESSION
:
825 s_wrpkt_start(11, 16);
826 pktout
.body
[0] = (rows
>> 24) & 0xFF;
827 pktout
.body
[1] = (rows
>> 16) & 0xFF;
828 pktout
.body
[2] = (rows
>> 8) & 0xFF;
829 pktout
.body
[3] = rows
& 0xFF;
830 pktout
.body
[4] = (cols
>> 24) & 0xFF;
831 pktout
.body
[5] = (cols
>> 16) & 0xFF;
832 pktout
.body
[6] = (cols
>> 8) & 0xFF;
833 pktout
.body
[7] = cols
& 0xFF;
834 memset(pktout
.body
+8, 0, 8);
841 * (Send Telnet special codes)
843 static void ssh_special (Telnet_Special code
) {
847 Backend ssh_backend
= {