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
,
51 } ssh_state
= SSH_STATE_BEFORE_SIZE
;
53 static int size_needed
= FALSE
;
55 static void s_write (char *buf
, int len
) {
57 int i
= send (s
, buf
, len
, 0);
63 static int s_read (char *buf
, int len
) {
66 int i
= recv (s
, buf
, len
, 0);
68 len
-= i
, buf
+= i
, ret
+= i
;
75 static void c_write (char *buf
, int len
) {
77 int new_head
= (inbuf_head
+ 1) & INBUF_MASK
;
78 int c
= (unsigned char) *buf
;
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 c
, *p
;
105 static char padding
[8];
106 static unsigned char word
[4];
110 for (i
= len
= 0; i
< 4; i
++) {
113 len
= (len
<< 8) + *data
;
121 len
-= 5; /* type and CRC */
124 if (pktin
.maxlen
< biglen
) {
125 pktin
.maxlen
= biglen
;
126 pktin
.data
= (pktin
.data
== NULL ?
malloc(biglen
) :
127 realloc(pktin
.data
, biglen
));
129 fatalbox("Out of memory");
132 p
= pktin
.data
, to_read
= biglen
;
133 while (to_read
> 0) {
140 memcpy(p
, data
, chunk
);
148 cipher
->decrypt(pktin
.data
, biglen
);
150 pktin
.type
= pktin
.data
[pad
];
151 pktin
.body
= pktin
.data
+pad
+1;
153 if (pktin
.type
== 36) { /* SSH_MSG_DEBUG */
156 ssh_protocol(NULL
, 0, 1);
161 static void s_wrpkt_start(int type
, int len
) {
164 len
+= 5; /* type and CRC */
168 pktout
.length
= len
-5;
169 if (pktout
.maxlen
< biglen
) {
170 pktout
.maxlen
= biglen
;
171 pktout
.data
= (pktout
.data
== NULL ?
malloc(biglen
) :
172 realloc(pktout
.data
, biglen
));
174 fatalbox("Out of memory");
178 pktout
.body
= pktout
.data
+4+pad
+1;
181 static void s_wrpkt(void) {
182 int pad
, len
, biglen
, i
;
185 len
= pktout
.length
+ 5; /* type and CRC */
189 pktout
.body
[-1] = pktout
.type
;
190 for (i
=0; i
<pad
; i
++)
191 pktout
.data
[i
+4] = random_byte();
192 crc
= crc32(pktout
.data
+4, biglen
-4);
194 pktout
.data
[biglen
+0] = (unsigned char) ((crc
>> 24) & 0xFF);
195 pktout
.data
[biglen
+1] = (unsigned char) ((crc
>> 16) & 0xFF);
196 pktout
.data
[biglen
+2] = (unsigned char) ((crc
>> 8) & 0xFF);
197 pktout
.data
[biglen
+3] = (unsigned char) (crc
& 0xFF);
199 pktout
.data
[0] = (len
>> 24) & 0xFF;
200 pktout
.data
[1] = (len
>> 16) & 0xFF;
201 pktout
.data
[2] = (len
>> 8) & 0xFF;
202 pktout
.data
[3] = len
& 0xFF;
205 cipher
->encrypt(pktout
.data
+4, biglen
);
207 s_write(pktout
.data
, biglen
+4);
210 static int do_ssh_init(void) {
218 while (s_read(&c
, 1) == 1) {
219 if (c
== 'S' && i
< 2) i
++;
220 else if (c
== 'S' && i
== 2) i
= 2;
221 else if (c
== 'H' && i
== 2) break;
225 if (s_read(&c
,1) != 1 || c
!= 'S') return 0;
226 if (s_read(&c
,1) != 1 || c
!= 'S') return 0;
227 if (s_read(&c
,1) != 1 || c
!= 'H') return 0;
229 if (s_read(&c
,1) != 1 || c
!= '-') return 0;
232 if (s_read(&c
,1) != 1)
238 } else if (i
< sizeof(version
)-1)
245 sprintf(vstring
, "SSH-%s-7.7.7\n",
246 (strcmp(version
, "1.5") <= 0 ? version
: "1.5"));
247 s_write(vstring
, strlen(vstring
));
250 static void ssh_protocol(unsigned char *in
, int inlen
, int ispkt
) {
252 unsigned char session_id
[16];
253 unsigned char *rsabuf
, *keystr1
, *keystr2
;
254 unsigned char cookie
[8];
255 struct RSAKey servkey
, hostkey
;
256 struct MD5Context md5c
;
258 extern struct ssh_cipher ssh_3des
;
268 fatalbox("Public key packet not received");
270 memcpy(cookie
, pktin
.body
, 8);
274 i
= makekey(pktin
.body
+8, &servkey
, &keystr1
);
276 j
= makekey(pktin
.body
+8+i
, &hostkey
, &keystr2
);
278 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
279 MD5Update(&md5c
, keystr1
, servkey
.bytes
);
280 MD5Update(&md5c
, pktin
.body
, 8);
282 MD5Final(session_id
, &md5c
);
285 session_key
[i
] = random_byte();
287 len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
289 rsabuf
= malloc(len
);
291 fatalbox("Out of memory");
293 verify_ssh_host_key(savedhost
, &hostkey
);
295 for (i
=0; i
<32; i
++) {
296 rsabuf
[i
] = session_key
[i
];
298 rsabuf
[i
] ^= session_id
[i
];
301 if (hostkey
.bytes
> servkey
.bytes
) {
302 rsaencrypt(rsabuf
, 32, &servkey
);
303 rsaencrypt(rsabuf
, servkey
.bytes
, &hostkey
);
305 rsaencrypt(rsabuf
, 32, &hostkey
);
306 rsaencrypt(rsabuf
, hostkey
.bytes
, &servkey
);
309 s_wrpkt_start(3, len
+15);
310 pktout
.body
[0] = 3; /* SSH_CIPHER_3DES */
311 memcpy(pktout
.body
+1, cookie
, 8);
312 pktout
.body
[9] = (len
*8) >> 8;
313 pktout
.body
[10] = (len
*8) & 0xFF;
314 memcpy(pktout
.body
+11, rsabuf
, len
);
315 pktout
.body
[len
+11] = pktout
.body
[len
+12] = 0; /* protocol flags */
316 pktout
.body
[len
+13] = pktout
.body
[len
+14] = 0;
322 cipher
->sesskey(session_key
);
324 do { crReturnV
; } while (!ispkt
);
326 if (pktin
.type
!= 14)
327 fatalbox("Encryption not successfully enabled");
331 static char username
[100];
334 if (!*cfg
.username
) {
335 c_write("login as: ", 10);
337 do { crReturnV
; } while (ispkt
);
338 while (inlen
--) switch (c
= *in
++) {
360 if (c
>= ' ' && c
<= '~' && pos
< 40) {
368 username
[strcspn(username
, "\n\r")] = '\0';
371 strncpy(username
, cfg
.username
, 99);
373 sprintf(stuff
, "Sent username \"%s\".\r\n", username
);
374 c_write(stuff
, strlen(stuff
));
376 s_wrpkt_start(4, 4+strlen(username
));
377 pktout
.body
[0] = pktout
.body
[1] = pktout
.body
[2] = 0;
378 pktout
.body
[3] = strlen(username
);
379 memcpy(pktout
.body
+4, username
, strlen(username
));
383 do { crReturnV
; } while (!ispkt
);
385 while (pktin
.type
== 15) {
386 static char password
[100];
389 c_write("password: ", 10);
392 do { crReturnV
; } while (ispkt
);
393 while (inlen
--) switch (c
= *in
++) {
410 if (c
>= ' ' && c
<= '~' && pos
< 40)
416 s_wrpkt_start(9, 4+strlen(password
));
417 pktout
.body
[0] = pktout
.body
[1] = pktout
.body
[2] = 0;
418 pktout
.body
[3] = strlen(password
);
419 memcpy(pktout
.body
+4, password
, strlen(password
));
421 memset(password
, 0, strlen(password
));
422 do { crReturnV
; } while (!ispkt
);
423 if (pktin
.type
== 15) {
424 c_write("Access denied\r\n", 15);
425 } else if (pktin
.type
!= 14) {
426 fatalbox("Strange packet received, type %d", pktin
.type
);
430 i
= strlen(cfg
.termtype
);
431 s_wrpkt_start(10, i
+5*4+1);
432 pktout
.body
[0] = (i
>> 24) & 0xFF;
433 pktout
.body
[1] = (i
>> 16) & 0xFF;
434 pktout
.body
[2] = (i
>> 8) & 0xFF;
435 pktout
.body
[3] = i
& 0xFF;
436 memcpy(pktout
.body
+4, cfg
.termtype
, i
);
438 pktout
.body
[i
++] = (rows
>> 24) & 0xFF;
439 pktout
.body
[i
++] = (rows
>> 16) & 0xFF;
440 pktout
.body
[i
++] = (rows
>> 8) & 0xFF;
441 pktout
.body
[i
++] = rows
& 0xFF;
442 pktout
.body
[i
++] = (cols
>> 24) & 0xFF;
443 pktout
.body
[i
++] = (cols
>> 16) & 0xFF;
444 pktout
.body
[i
++] = (cols
>> 8) & 0xFF;
445 pktout
.body
[i
++] = cols
& 0xFF;
446 memset(pktout
.body
+i
, 0, 9); /* 0 pixwidth, 0 pixheight, 0.b endofopt */
448 ssh_state
= SSH_STATE_INTERMED
;
449 do { crReturnV
; } while (!ispkt
);
450 if (pktin
.type
!= 14 && pktin
.type
!= 15) {
451 fatalbox("Protocol confusion");
452 } else if (pktin
.type
== 15) {
453 c_write("Server refused to allocate pty\r\n", 32);
456 s_wrpkt_start(12, 0);
459 ssh_state
= SSH_STATE_SESSION
;
466 if (pktin
.type
== 17 || pktin
.type
== 18) {
468 for (i
= 0; i
< 4; i
++)
469 len
= (len
<< 8) + pktin
.body
[i
];
470 c_write(pktin
.body
+4, len
);
471 } else if (pktin
.type
== 1) {
472 /* SSH_MSG_DISCONNECT: do nothing */
473 } else if (pktin
.type
== 14) {
474 /* SSH_MSG_SUCCESS: may be from EXEC_SHELL on some servers */
475 } else if (pktin
.type
== 15) {
476 /* SSH_MSG_FAILURE: may be from EXEC_SHELL on some servers
477 * if no pty is available or in other odd cases. Ignore */
478 } else if (pktin
.type
== 20) {
480 s_wrpkt_start(33, 0);
483 fatalbox("Strange packet received: type %d", pktin
.type
);
486 s_wrpkt_start(16, 4+inlen
);
487 pktout
.body
[0] = (inlen
>> 24) & 0xFF;
488 pktout
.body
[1] = (inlen
>> 16) & 0xFF;
489 pktout
.body
[2] = (inlen
>> 8) & 0xFF;
490 pktout
.body
[3] = inlen
& 0xFF;
491 memcpy(pktout
.body
+4, in
, inlen
);
500 * Called to set up the connection. Will arrange for WM_NETEVENT
501 * messages to be passed to the specified window, whose window
502 * procedure should then call telnet_msg().
504 * Returns an error message, or NULL on success.
506 * Also places the canonical host name into `realhost'.
508 static char *ssh_init (HWND hwnd
, char *host
, int port
, char **realhost
) {
517 savedhost
= malloc(1+strlen(host
));
519 fatalbox("Out of memory");
520 strcpy(savedhost
, host
);
532 if ( (a
= inet_addr(host
)) == (unsigned long) INADDR_NONE
) {
533 if ( (h
= gethostbyname(host
)) == NULL
)
534 switch (WSAGetLastError()) {
535 case WSAENETDOWN
: return "Network is down";
536 case WSAHOST_NOT_FOUND
: case WSANO_DATA
:
537 return "Host does not exist";
538 case WSATRY_AGAIN
: return "Host not found";
539 default: return "gethostbyname: unknown error";
541 memcpy (&a
, h
->h_addr
, sizeof(a
));
542 *realhost
= h
->h_name
;
551 port
= 22; /* default ssh port */
556 s
= socket(AF_INET
, SOCK_STREAM
, 0);
557 if (s
== INVALID_SOCKET
)
558 switch (WSAGetLastError()) {
559 case WSAENETDOWN
: return "Network is down";
560 case WSAEAFNOSUPPORT
: return "TCP/IP support not present";
561 default: return "socket(): unknown error";
565 * Bind to local address.
567 addr
.sin_family
= AF_INET
;
568 addr
.sin_addr
.s_addr
= htonl(INADDR_ANY
);
569 addr
.sin_port
= htons(0);
570 if (bind (s
, (struct sockaddr
*)&addr
, sizeof(addr
)) == SOCKET_ERROR
)
571 switch (WSAGetLastError()) {
572 case WSAENETDOWN
: return "Network is down";
573 default: return "bind(): unknown error";
577 * Connect to remote address.
579 addr
.sin_addr
.s_addr
= htonl(a
);
580 addr
.sin_port
= htons((short)port
);
581 if (connect (s
, (struct sockaddr
*)&addr
, sizeof(addr
)) == SOCKET_ERROR
)
582 switch (WSAGetLastError()) {
583 case WSAENETDOWN
: return "Network is down";
584 case WSAECONNREFUSED
: return "Connection refused";
585 case WSAENETUNREACH
: return "Network is unreachable";
586 case WSAEHOSTUNREACH
: return "No route to host";
587 default: return "connect(): unknown error";
591 send(s
, "connect ", 8, 0);
592 send(s
, FWhost
, strlen(FWhost
), 0);
595 sprintf(buf
, " %d\n", FWport
);
596 send (s
, buf
, strlen(buf
), 0);
601 return "Protocol initialisation error";
603 if (WSAAsyncSelect (s
, hwnd
, WM_NETEVENT
, FD_READ
| FD_CLOSE
) == SOCKET_ERROR
)
604 switch (WSAGetLastError()) {
605 case WSAENETDOWN
: return "Network is down";
606 default: return "WSAAsyncSelect(): unknown error";
613 * Process a WM_NETEVENT message. Will return 0 if the connection
614 * has closed, or <0 for a socket error.
616 static int ssh_msg (WPARAM wParam
, LPARAM lParam
) {
620 if (s
== INVALID_SOCKET
) /* how the hell did we get here?! */
623 if (WSAGETSELECTERROR(lParam
) != 0)
624 return -WSAGETSELECTERROR(lParam
);
626 switch (WSAGETSELECTEVENT(lParam
)) {
628 ret
= recv(s
, buf
, sizeof(buf
), 0);
629 if (ret
< 0 && WSAGetLastError() == WSAEWOULDBLOCK
)
631 if (ret
< 0) /* any _other_ error */
632 return -10000-WSAGetLastError();
635 return 0; /* can't happen, in theory */
637 ssh_gotdata (buf
, ret
);
643 return 1; /* shouldn't happen, but WTF */
647 * Called to send data down the Telnet connection.
649 static void ssh_send (char *buf
, int len
) {
650 if (s
== INVALID_SOCKET
)
653 ssh_protocol(buf
, len
, 0);
657 * Called to set the size of the window from Telnet's POV.
659 static void ssh_size(void) {
661 case SSH_STATE_BEFORE_SIZE
:
662 break; /* do nothing */
663 case SSH_STATE_INTERMED
:
664 size_needed
= TRUE
; /* buffer for later */
666 case SSH_STATE_SESSION
:
667 s_wrpkt_start(11, 16);
668 pktout
.body
[0] = (rows
>> 24) & 0xFF;
669 pktout
.body
[1] = (rows
>> 16) & 0xFF;
670 pktout
.body
[2] = (rows
>> 8) & 0xFF;
671 pktout
.body
[3] = rows
& 0xFF;
672 pktout
.body
[4] = (cols
>> 24) & 0xFF;
673 pktout
.body
[5] = (cols
>> 16) & 0xFF;
674 pktout
.body
[6] = (cols
>> 8) & 0xFF;
675 pktout
.body
[7] = cols
& 0xFF;
676 memset(pktout
.body
+8, 0, 8);
682 * (Send Telnet special codes)
684 static void ssh_special (Telnet_Special code
) {
688 Backend ssh_backend
= {