16 /* Coroutine mechanics for the sillier bits of the code */
17 #define crBegin1 static int crLine = 0;
18 #define crBegin2 switch(crLine) { case 0:;
19 #define crBegin crBegin1; crBegin2;
20 #define crFinish(z) } crLine = 0; return (z)
21 #define crFinishV } crLine = 0; return
24 crLine=__LINE__; return (z); case __LINE__:;\
28 crLine=__LINE__; return; case __LINE__:;\
30 #define crStop(z) do{ crLine = 0; return (z); }while(0)
31 #define crStopV do{ crLine = 0; return; }while(0)
40 static SOCKET s
= INVALID_SOCKET
;
42 static unsigned char session_key
[32];
43 static struct ssh_cipher
*cipher
= NULL
;
45 static char *savedhost
;
48 SSH_STATE_BEFORE_SIZE
,
52 } ssh_state
= SSH_STATE_BEFORE_SIZE
;
54 static int size_needed
= FALSE
;
56 static void s_write (char *buf
, int len
) {
58 int i
= send (s
, buf
, len
, 0);
64 static int s_read (char *buf
, int len
) {
67 int i
= recv (s
, buf
, len
, 0);
69 len
-= i
, buf
+= i
, ret
+= i
;
76 static void c_write (char *buf
, int len
) {
78 int new_head
= (inbuf_head
+ 1) & INBUF_MASK
;
79 if (new_head
!= inbuf_reap
) {
80 inbuf
[inbuf_head
] = *buf
++;
81 inbuf_head
= new_head
;
95 static struct Packet pktin
= { 0, 0, 0, NULL
, 0 };
96 static struct Packet pktout
= { 0, 0, 0, NULL
, 0 };
98 static void ssh_protocol(unsigned char *in
, int inlen
, int ispkt
);
99 static void ssh_size(void);
101 static void ssh_gotdata(unsigned char *data
, int datalen
) {
102 static long len
, biglen
, to_read
;
103 static unsigned char *p
;
108 for (i
= len
= 0; i
< 4; i
++) {
111 len
= (len
<< 8) + *data
;
116 if (len
== 0x52656d6f) { /* "Remo"te server has closed ... */
117 len
= 0x300; /* big enough to carry to end */
125 len
-= 5; /* type and CRC */
128 if (pktin
.maxlen
< biglen
) {
129 pktin
.maxlen
= biglen
;
130 pktin
.data
= (pktin
.data
== NULL ?
malloc(biglen
) :
131 realloc(pktin
.data
, biglen
));
133 fatalbox("Out of memory");
136 p
= pktin
.data
, to_read
= biglen
;
137 while (to_read
> 0) {
144 memcpy(p
, data
, chunk
);
152 cipher
->decrypt(pktin
.data
, biglen
);
154 pktin
.type
= pktin
.data
[pad
];
155 pktin
.body
= pktin
.data
+pad
+1;
157 if (pktin
.type
== 36) { /* SSH_MSG_DEBUG */
159 } else if (pktin
.type
== 32) { /* SSH_MSG_IGNORE */
162 ssh_protocol(NULL
, 0, 1);
167 static void s_wrpkt_start(int type
, int len
) {
170 len
+= 5; /* type and CRC */
174 pktout
.length
= len
-5;
175 if (pktout
.maxlen
< biglen
) {
176 pktout
.maxlen
= biglen
;
177 pktout
.data
= (pktout
.data
== NULL ?
malloc(biglen
+4) :
178 realloc(pktout
.data
, biglen
+4));
180 fatalbox("Out of memory");
184 pktout
.body
= pktout
.data
+4+pad
+1;
187 static void s_wrpkt(void) {
188 int pad
, len
, biglen
, i
;
191 len
= pktout
.length
+ 5; /* type and CRC */
195 pktout
.body
[-1] = pktout
.type
;
196 for (i
=0; i
<pad
; i
++)
197 pktout
.data
[i
+4] = random_byte();
198 crc
= crc32(pktout
.data
+4, biglen
-4);
200 pktout
.data
[biglen
+0] = (unsigned char) ((crc
>> 24) & 0xFF);
201 pktout
.data
[biglen
+1] = (unsigned char) ((crc
>> 16) & 0xFF);
202 pktout
.data
[biglen
+2] = (unsigned char) ((crc
>> 8) & 0xFF);
203 pktout
.data
[biglen
+3] = (unsigned char) (crc
& 0xFF);
205 pktout
.data
[0] = (len
>> 24) & 0xFF;
206 pktout
.data
[1] = (len
>> 16) & 0xFF;
207 pktout
.data
[2] = (len
>> 8) & 0xFF;
208 pktout
.data
[3] = len
& 0xFF;
211 cipher
->encrypt(pktout
.data
+4, biglen
);
213 s_write(pktout
.data
, biglen
+4);
216 static int ssh_versioncmp(char *a
, char *b
) {
218 unsigned long av
, bv
;
220 av
= strtoul(a
, &ae
, 10);
221 bv
= strtoul(b
, &be
, 10);
222 if (av
!= bv
) return (av
< bv ?
-1 : +1);
223 if (*ae
== '.') ae
++;
224 if (*be
== '.') be
++;
225 av
= strtoul(ae
, &ae
, 10);
226 bv
= strtoul(be
, &be
, 10);
227 if (av
!= bv
) return (av
< bv ?
-1 : +1);
231 static int do_ssh_init(void) {
239 while (s_read(&c
, 1) == 1) {
240 if (c
== 'S' && i
< 2) i
++;
241 else if (c
== 'S' && i
== 2) i
= 2;
242 else if (c
== 'H' && i
== 2) break;
246 if (s_read(&c
,1) != 1 || c
!= 'S') return 0;
247 if (s_read(&c
,1) != 1 || c
!= 'S') return 0;
248 if (s_read(&c
,1) != 1 || c
!= 'H') return 0;
250 if (s_read(&c
,1) != 1 || c
!= '-') return 0;
253 if (s_read(&c
,1) != 1)
259 } else if (i
< sizeof(version
)-1)
266 sprintf(vstring
, "SSH-%s-PuTTY\n",
267 (ssh_versioncmp(version
, "1.5") <= 0 ? version
: "1.5"));
268 s_write(vstring
, strlen(vstring
));
272 static void ssh_protocol(unsigned char *in
, int inlen
, int ispkt
) {
274 unsigned char session_id
[16];
275 unsigned char *rsabuf
, *keystr1
, *keystr2
;
276 unsigned char cookie
[8];
277 struct RSAKey servkey
, hostkey
;
278 struct MD5Context md5c
;
279 unsigned long supported_ciphers_mask
;
282 extern struct ssh_cipher ssh_3des
;
283 extern struct ssh_cipher ssh_des
;
284 extern struct ssh_cipher ssh_blowfish
;
294 fatalbox("Public key packet not received");
296 memcpy(cookie
, pktin
.body
, 8);
300 i
= makekey(pktin
.body
+8, &servkey
, &keystr1
);
302 j
= makekey(pktin
.body
+8+i
, &hostkey
, &keystr2
);
304 supported_ciphers_mask
= (pktin
.body
[12+i
+j
] << 24) |
305 (pktin
.body
[13+i
+j
] << 16) |
306 (pktin
.body
[14+i
+j
] << 8) |
307 (pktin
.body
[15+i
+j
]);
309 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
310 MD5Update(&md5c
, keystr1
, servkey
.bytes
);
311 MD5Update(&md5c
, pktin
.body
, 8);
313 MD5Final(session_id
, &md5c
);
316 session_key
[i
] = random_byte();
318 len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
320 rsabuf
= malloc(len
);
322 fatalbox("Out of memory");
324 verify_ssh_host_key(savedhost
, &hostkey
);
326 for (i
=0; i
<32; i
++) {
327 rsabuf
[i
] = session_key
[i
];
329 rsabuf
[i
] ^= session_id
[i
];
332 if (hostkey
.bytes
> servkey
.bytes
) {
333 rsaencrypt(rsabuf
, 32, &servkey
);
334 rsaencrypt(rsabuf
, servkey
.bytes
, &hostkey
);
336 rsaencrypt(rsabuf
, 32, &hostkey
);
337 rsaencrypt(rsabuf
, hostkey
.bytes
, &servkey
);
340 cipher_type
= cfg
.cipher
== CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH
:
341 cfg
.cipher
== CIPHER_DES ? SSH_CIPHER_DES
:
343 if ((supported_ciphers_mask
& (1 << cipher_type
)) == 0) {
344 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
345 cipher_type
= SSH_CIPHER_3DES
;
348 s_wrpkt_start(3, len
+15);
349 pktout
.body
[0] = cipher_type
;
350 memcpy(pktout
.body
+1, cookie
, 8);
351 pktout
.body
[9] = (len
*8) >> 8;
352 pktout
.body
[10] = (len
*8) & 0xFF;
353 memcpy(pktout
.body
+11, rsabuf
, len
);
354 pktout
.body
[len
+11] = pktout
.body
[len
+12] = 0; /* protocol flags */
355 pktout
.body
[len
+13] = pktout
.body
[len
+14] = 0;
360 cipher
= cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish
:
361 cipher_type
== SSH_CIPHER_DES ?
&ssh_des
:
363 cipher
->sesskey(session_key
);
365 do { crReturnV
; } while (!ispkt
);
367 if (pktin
.type
!= 14)
368 fatalbox("Encryption not successfully enabled");
372 static char username
[100];
375 if (!*cfg
.username
) {
376 c_write("login as: ", 10);
378 do { crReturnV
; } while (ispkt
);
379 while (inlen
--) switch (c
= *in
++) {
401 if (c
>= ' ' && c
<= '~' && pos
< 40) {
409 username
[strcspn(username
, "\n\r")] = '\0';
412 strncpy(username
, cfg
.username
, 99);
414 sprintf(stuff
, "Sent username \"%s\".\r\n", username
);
415 c_write(stuff
, strlen(stuff
));
417 s_wrpkt_start(4, 4+strlen(username
));
418 pktout
.body
[0] = pktout
.body
[1] = pktout
.body
[2] = 0;
419 pktout
.body
[3] = strlen(username
);
420 memcpy(pktout
.body
+4, username
, strlen(username
));
424 do { crReturnV
; } while (!ispkt
);
426 while (pktin
.type
== 15) {
427 static char password
[100];
430 c_write("password: ", 10);
433 do { crReturnV
; } while (ispkt
);
434 while (inlen
--) switch (c
= *in
++) {
451 if (c
>= ' ' && c
<= '~' && pos
< 40)
457 s_wrpkt_start(9, 4+strlen(password
));
458 pktout
.body
[0] = pktout
.body
[1] = pktout
.body
[2] = 0;
459 pktout
.body
[3] = strlen(password
);
460 memcpy(pktout
.body
+4, password
, strlen(password
));
462 memset(password
, 0, strlen(password
));
463 do { crReturnV
; } while (!ispkt
);
464 if (pktin
.type
== 15) {
465 c_write("Access denied\r\n", 15);
466 } else if (pktin
.type
!= 14) {
467 fatalbox("Strange packet received, type %d", pktin
.type
);
472 i
= strlen(cfg
.termtype
);
473 s_wrpkt_start(10, i
+5*4+1);
474 pktout
.body
[0] = (i
>> 24) & 0xFF;
475 pktout
.body
[1] = (i
>> 16) & 0xFF;
476 pktout
.body
[2] = (i
>> 8) & 0xFF;
477 pktout
.body
[3] = i
& 0xFF;
478 memcpy(pktout
.body
+4, cfg
.termtype
, i
);
480 pktout
.body
[i
++] = (rows
>> 24) & 0xFF;
481 pktout
.body
[i
++] = (rows
>> 16) & 0xFF;
482 pktout
.body
[i
++] = (rows
>> 8) & 0xFF;
483 pktout
.body
[i
++] = rows
& 0xFF;
484 pktout
.body
[i
++] = (cols
>> 24) & 0xFF;
485 pktout
.body
[i
++] = (cols
>> 16) & 0xFF;
486 pktout
.body
[i
++] = (cols
>> 8) & 0xFF;
487 pktout
.body
[i
++] = cols
& 0xFF;
488 memset(pktout
.body
+i
, 0, 9); /* 0 pixwidth, 0 pixheight, 0.b endofopt */
490 ssh_state
= SSH_STATE_INTERMED
;
491 do { crReturnV
; } while (!ispkt
);
492 if (pktin
.type
!= 14 && pktin
.type
!= 15) {
493 fatalbox("Protocol confusion");
494 } else if (pktin
.type
== 15) {
495 c_write("Server refused to allocate pty\r\n", 32);
499 s_wrpkt_start(12, 0);
502 ssh_state
= SSH_STATE_SESSION
;
509 if (pktin
.type
== 17 || pktin
.type
== 18) {
511 for (i
= 0; i
< 4; i
++)
512 len
= (len
<< 8) + pktin
.body
[i
];
513 c_write(pktin
.body
+4, len
);
514 } else if (pktin
.type
== 1) {
515 /* SSH_MSG_DISCONNECT */
516 ssh_state
= SSH_STATE_CLOSED
;
517 } else if (pktin
.type
== 14) {
518 /* SSH_MSG_SUCCESS: may be from EXEC_SHELL on some servers */
519 } else if (pktin
.type
== 15) {
520 /* SSH_MSG_FAILURE: may be from EXEC_SHELL on some servers
521 * if no pty is available or in other odd cases. Ignore */
522 } else if (pktin
.type
== 20) {
524 s_wrpkt_start(33, 0);
527 fatalbox("Strange packet received: type %d", pktin
.type
);
530 s_wrpkt_start(16, 4+inlen
);
531 pktout
.body
[0] = (inlen
>> 24) & 0xFF;
532 pktout
.body
[1] = (inlen
>> 16) & 0xFF;
533 pktout
.body
[2] = (inlen
>> 8) & 0xFF;
534 pktout
.body
[3] = inlen
& 0xFF;
535 memcpy(pktout
.body
+4, in
, inlen
);
544 * Called to set up the connection. Will arrange for WM_NETEVENT
545 * messages to be passed to the specified window, whose window
546 * procedure should then call telnet_msg().
548 * Returns an error message, or NULL on success.
550 * Also places the canonical host name into `realhost'.
552 static char *ssh_init (HWND hwnd
, char *host
, int port
, char **realhost
) {
561 savedhost
= malloc(1+strlen(host
));
563 fatalbox("Out of memory");
564 strcpy(savedhost
, host
);
576 if ( (a
= inet_addr(host
)) == (unsigned long) INADDR_NONE
) {
577 if ( (h
= gethostbyname(host
)) == NULL
)
578 switch (WSAGetLastError()) {
579 case WSAENETDOWN
: return "Network is down";
580 case WSAHOST_NOT_FOUND
: case WSANO_DATA
:
581 return "Host does not exist";
582 case WSATRY_AGAIN
: return "Host not found";
583 default: return "gethostbyname: unknown error";
585 memcpy (&a
, h
->h_addr
, sizeof(a
));
586 *realhost
= h
->h_name
;
595 port
= 22; /* default ssh port */
600 s
= socket(AF_INET
, SOCK_STREAM
, 0);
601 if (s
== INVALID_SOCKET
)
602 switch (WSAGetLastError()) {
603 case WSAENETDOWN
: return "Network is down";
604 case WSAEAFNOSUPPORT
: return "TCP/IP support not present";
605 default: return "socket(): unknown error";
609 * Bind to local address.
611 addr
.sin_family
= AF_INET
;
612 addr
.sin_addr
.s_addr
= htonl(INADDR_ANY
);
613 addr
.sin_port
= htons(0);
614 if (bind (s
, (struct sockaddr
*)&addr
, sizeof(addr
)) == SOCKET_ERROR
)
615 switch (WSAGetLastError()) {
616 case WSAENETDOWN
: return "Network is down";
617 default: return "bind(): unknown error";
621 * Connect to remote address.
623 addr
.sin_addr
.s_addr
= htonl(a
);
624 addr
.sin_port
= htons((short)port
);
625 if (connect (s
, (struct sockaddr
*)&addr
, sizeof(addr
)) == SOCKET_ERROR
)
626 switch (WSAGetLastError()) {
627 case WSAENETDOWN
: return "Network is down";
628 case WSAECONNREFUSED
: return "Connection refused";
629 case WSAENETUNREACH
: return "Network is unreachable";
630 case WSAEHOSTUNREACH
: return "No route to host";
631 default: return "connect(): unknown error";
635 send(s
, "connect ", 8, 0);
636 send(s
, FWhost
, strlen(FWhost
), 0);
639 sprintf(buf
, " %d\n", FWport
);
640 send (s
, buf
, strlen(buf
), 0);
645 return "Protocol initialisation error";
647 if (WSAAsyncSelect (s
, hwnd
, WM_NETEVENT
, FD_READ
| FD_CLOSE
) == SOCKET_ERROR
)
648 switch (WSAGetLastError()) {
649 case WSAENETDOWN
: return "Network is down";
650 default: return "WSAAsyncSelect(): unknown error";
657 * Process a WM_NETEVENT message. Will return 0 if the connection
658 * has closed, or <0 for a socket error.
660 static int ssh_msg (WPARAM wParam
, LPARAM lParam
) {
664 if (s
== INVALID_SOCKET
) /* how the hell did we get here?! */
667 if (WSAGETSELECTERROR(lParam
) != 0)
668 return -WSAGETSELECTERROR(lParam
);
670 switch (WSAGETSELECTEVENT(lParam
)) {
672 ret
= recv(s
, buf
, sizeof(buf
), 0);
673 if (ret
< 0 && WSAGetLastError() == WSAEWOULDBLOCK
)
675 if (ret
< 0) /* any _other_ error */
676 return -10000-WSAGetLastError();
679 return 0; /* can't happen, in theory */
681 ssh_gotdata (buf
, ret
);
685 ssh_state
= SSH_STATE_CLOSED
;
688 return 1; /* shouldn't happen, but WTF */
692 * Called to send data down the Telnet connection.
694 static void ssh_send (char *buf
, int len
) {
695 if (s
== INVALID_SOCKET
)
698 ssh_protocol(buf
, len
, 0);
702 * Called to set the size of the window from Telnet's POV.
704 static void ssh_size(void) {
706 case SSH_STATE_BEFORE_SIZE
:
707 case SSH_STATE_CLOSED
:
708 break; /* do nothing */
709 case SSH_STATE_INTERMED
:
710 size_needed
= TRUE
; /* buffer for later */
712 case SSH_STATE_SESSION
:
714 s_wrpkt_start(11, 16);
715 pktout
.body
[0] = (rows
>> 24) & 0xFF;
716 pktout
.body
[1] = (rows
>> 16) & 0xFF;
717 pktout
.body
[2] = (rows
>> 8) & 0xFF;
718 pktout
.body
[3] = rows
& 0xFF;
719 pktout
.body
[4] = (cols
>> 24) & 0xFF;
720 pktout
.body
[5] = (cols
>> 16) & 0xFF;
721 pktout
.body
[6] = (cols
>> 8) & 0xFF;
722 pktout
.body
[7] = cols
& 0xFF;
723 memset(pktout
.body
+8, 0, 8);
730 * (Send Telnet special codes)
732 static void ssh_special (Telnet_Special code
) {
736 Backend ssh_backend
= {