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
;
118 if (len
== 0x52656d6f) { /* "Remo"te server has closed ... */
119 len
= 0x300; /* big enough to carry to end */
127 len
-= 5; /* type and CRC */
130 if (pktin
.maxlen
< biglen
) {
131 pktin
.maxlen
= biglen
;
132 pktin
.data
= (pktin
.data
== NULL ?
malloc(biglen
) :
133 realloc(pktin
.data
, biglen
));
135 fatalbox("Out of memory");
138 p
= pktin
.data
, to_read
= biglen
;
139 while (to_read
> 0) {
146 memcpy(p
, data
, chunk
);
154 cipher
->decrypt(pktin
.data
, biglen
);
156 pktin
.type
= pktin
.data
[pad
];
157 pktin
.body
= pktin
.data
+pad
+1;
159 if (pktin
.type
== 36) { /* SSH_MSG_DEBUG */
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
) :
178 realloc(pktout
.data
, biglen
));
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 do_ssh_init(void) {
224 while (s_read(&c
, 1) == 1) {
225 if (c
== 'S' && i
< 2) i
++;
226 else if (c
== 'S' && i
== 2) i
= 2;
227 else if (c
== 'H' && i
== 2) break;
231 if (s_read(&c
,1) != 1 || c
!= 'S') return 0;
232 if (s_read(&c
,1) != 1 || c
!= 'S') return 0;
233 if (s_read(&c
,1) != 1 || c
!= 'H') return 0;
235 if (s_read(&c
,1) != 1 || c
!= '-') return 0;
238 if (s_read(&c
,1) != 1)
244 } else if (i
< sizeof(version
)-1)
251 sprintf(vstring
, "SSH-%s-7.7.7\n",
252 (strcmp(version
, "1.5") <= 0 ? version
: "1.5"));
253 s_write(vstring
, strlen(vstring
));
256 static void ssh_protocol(unsigned char *in
, int inlen
, int ispkt
) {
258 unsigned char session_id
[16];
259 unsigned char *rsabuf
, *keystr1
, *keystr2
;
260 unsigned char cookie
[8];
261 struct RSAKey servkey
, hostkey
;
262 struct MD5Context md5c
;
264 extern struct ssh_cipher ssh_3des
;
274 fatalbox("Public key packet not received");
276 memcpy(cookie
, pktin
.body
, 8);
280 i
= makekey(pktin
.body
+8, &servkey
, &keystr1
);
282 j
= makekey(pktin
.body
+8+i
, &hostkey
, &keystr2
);
284 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
285 MD5Update(&md5c
, keystr1
, servkey
.bytes
);
286 MD5Update(&md5c
, pktin
.body
, 8);
288 MD5Final(session_id
, &md5c
);
291 session_key
[i
] = random_byte();
293 len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
295 rsabuf
= malloc(len
);
297 fatalbox("Out of memory");
299 verify_ssh_host_key(savedhost
, &hostkey
);
301 for (i
=0; i
<32; i
++) {
302 rsabuf
[i
] = session_key
[i
];
304 rsabuf
[i
] ^= session_id
[i
];
307 if (hostkey
.bytes
> servkey
.bytes
) {
308 rsaencrypt(rsabuf
, 32, &servkey
);
309 rsaencrypt(rsabuf
, servkey
.bytes
, &hostkey
);
311 rsaencrypt(rsabuf
, 32, &hostkey
);
312 rsaencrypt(rsabuf
, hostkey
.bytes
, &servkey
);
315 s_wrpkt_start(3, len
+15);
316 pktout
.body
[0] = 3; /* SSH_CIPHER_3DES */
317 memcpy(pktout
.body
+1, cookie
, 8);
318 pktout
.body
[9] = (len
*8) >> 8;
319 pktout
.body
[10] = (len
*8) & 0xFF;
320 memcpy(pktout
.body
+11, rsabuf
, len
);
321 pktout
.body
[len
+11] = pktout
.body
[len
+12] = 0; /* protocol flags */
322 pktout
.body
[len
+13] = pktout
.body
[len
+14] = 0;
328 cipher
->sesskey(session_key
);
330 do { crReturnV
; } while (!ispkt
);
332 if (pktin
.type
!= 14)
333 fatalbox("Encryption not successfully enabled");
337 static char username
[100];
340 if (!*cfg
.username
) {
341 c_write("login as: ", 10);
343 do { crReturnV
; } while (ispkt
);
344 while (inlen
--) switch (c
= *in
++) {
366 if (c
>= ' ' && c
<= '~' && pos
< 40) {
374 username
[strcspn(username
, "\n\r")] = '\0';
377 strncpy(username
, cfg
.username
, 99);
379 sprintf(stuff
, "Sent username \"%s\".\r\n", username
);
380 c_write(stuff
, strlen(stuff
));
382 s_wrpkt_start(4, 4+strlen(username
));
383 pktout
.body
[0] = pktout
.body
[1] = pktout
.body
[2] = 0;
384 pktout
.body
[3] = strlen(username
);
385 memcpy(pktout
.body
+4, username
, strlen(username
));
389 do { crReturnV
; } while (!ispkt
);
391 while (pktin
.type
== 15) {
392 static char password
[100];
395 c_write("password: ", 10);
398 do { crReturnV
; } while (ispkt
);
399 while (inlen
--) switch (c
= *in
++) {
416 if (c
>= ' ' && c
<= '~' && pos
< 40)
422 s_wrpkt_start(9, 4+strlen(password
));
423 pktout
.body
[0] = pktout
.body
[1] = pktout
.body
[2] = 0;
424 pktout
.body
[3] = strlen(password
);
425 memcpy(pktout
.body
+4, password
, strlen(password
));
427 memset(password
, 0, strlen(password
));
428 do { crReturnV
; } while (!ispkt
);
429 if (pktin
.type
== 15) {
430 c_write("Access denied\r\n", 15);
431 } else if (pktin
.type
!= 14) {
432 fatalbox("Strange packet received, type %d", pktin
.type
);
436 i
= strlen(cfg
.termtype
);
437 s_wrpkt_start(10, i
+5*4+1);
438 pktout
.body
[0] = (i
>> 24) & 0xFF;
439 pktout
.body
[1] = (i
>> 16) & 0xFF;
440 pktout
.body
[2] = (i
>> 8) & 0xFF;
441 pktout
.body
[3] = i
& 0xFF;
442 memcpy(pktout
.body
+4, cfg
.termtype
, i
);
444 pktout
.body
[i
++] = (rows
>> 24) & 0xFF;
445 pktout
.body
[i
++] = (rows
>> 16) & 0xFF;
446 pktout
.body
[i
++] = (rows
>> 8) & 0xFF;
447 pktout
.body
[i
++] = rows
& 0xFF;
448 pktout
.body
[i
++] = (cols
>> 24) & 0xFF;
449 pktout
.body
[i
++] = (cols
>> 16) & 0xFF;
450 pktout
.body
[i
++] = (cols
>> 8) & 0xFF;
451 pktout
.body
[i
++] = cols
& 0xFF;
452 memset(pktout
.body
+i
, 0, 9); /* 0 pixwidth, 0 pixheight, 0.b endofopt */
454 ssh_state
= SSH_STATE_INTERMED
;
455 do { crReturnV
; } while (!ispkt
);
456 if (pktin
.type
!= 14 && pktin
.type
!= 15) {
457 fatalbox("Protocol confusion");
458 } else if (pktin
.type
== 15) {
459 c_write("Server refused to allocate pty\r\n", 32);
462 s_wrpkt_start(12, 0);
465 ssh_state
= SSH_STATE_SESSION
;
472 if (pktin
.type
== 17 || pktin
.type
== 18) {
474 for (i
= 0; i
< 4; i
++)
475 len
= (len
<< 8) + pktin
.body
[i
];
476 c_write(pktin
.body
+4, len
);
477 } else if (pktin
.type
== 1) {
478 /* SSH_MSG_DISCONNECT: do nothing */
479 } else if (pktin
.type
== 14) {
480 /* SSH_MSG_SUCCESS: may be from EXEC_SHELL on some servers */
481 } else if (pktin
.type
== 15) {
482 /* SSH_MSG_FAILURE: may be from EXEC_SHELL on some servers
483 * if no pty is available or in other odd cases. Ignore */
484 } else if (pktin
.type
== 20) {
486 s_wrpkt_start(33, 0);
489 fatalbox("Strange packet received: type %d", pktin
.type
);
492 s_wrpkt_start(16, 4+inlen
);
493 pktout
.body
[0] = (inlen
>> 24) & 0xFF;
494 pktout
.body
[1] = (inlen
>> 16) & 0xFF;
495 pktout
.body
[2] = (inlen
>> 8) & 0xFF;
496 pktout
.body
[3] = inlen
& 0xFF;
497 memcpy(pktout
.body
+4, in
, inlen
);
506 * Called to set up the connection. Will arrange for WM_NETEVENT
507 * messages to be passed to the specified window, whose window
508 * procedure should then call telnet_msg().
510 * Returns an error message, or NULL on success.
512 * Also places the canonical host name into `realhost'.
514 static char *ssh_init (HWND hwnd
, char *host
, int port
, char **realhost
) {
523 savedhost
= malloc(1+strlen(host
));
525 fatalbox("Out of memory");
526 strcpy(savedhost
, host
);
538 if ( (a
= inet_addr(host
)) == (unsigned long) INADDR_NONE
) {
539 if ( (h
= gethostbyname(host
)) == NULL
)
540 switch (WSAGetLastError()) {
541 case WSAENETDOWN
: return "Network is down";
542 case WSAHOST_NOT_FOUND
: case WSANO_DATA
:
543 return "Host does not exist";
544 case WSATRY_AGAIN
: return "Host not found";
545 default: return "gethostbyname: unknown error";
547 memcpy (&a
, h
->h_addr
, sizeof(a
));
548 *realhost
= h
->h_name
;
557 port
= 22; /* default ssh port */
562 s
= socket(AF_INET
, SOCK_STREAM
, 0);
563 if (s
== INVALID_SOCKET
)
564 switch (WSAGetLastError()) {
565 case WSAENETDOWN
: return "Network is down";
566 case WSAEAFNOSUPPORT
: return "TCP/IP support not present";
567 default: return "socket(): unknown error";
571 * Bind to local address.
573 addr
.sin_family
= AF_INET
;
574 addr
.sin_addr
.s_addr
= htonl(INADDR_ANY
);
575 addr
.sin_port
= htons(0);
576 if (bind (s
, (struct sockaddr
*)&addr
, sizeof(addr
)) == SOCKET_ERROR
)
577 switch (WSAGetLastError()) {
578 case WSAENETDOWN
: return "Network is down";
579 default: return "bind(): unknown error";
583 * Connect to remote address.
585 addr
.sin_addr
.s_addr
= htonl(a
);
586 addr
.sin_port
= htons((short)port
);
587 if (connect (s
, (struct sockaddr
*)&addr
, sizeof(addr
)) == SOCKET_ERROR
)
588 switch (WSAGetLastError()) {
589 case WSAENETDOWN
: return "Network is down";
590 case WSAECONNREFUSED
: return "Connection refused";
591 case WSAENETUNREACH
: return "Network is unreachable";
592 case WSAEHOSTUNREACH
: return "No route to host";
593 default: return "connect(): unknown error";
597 send(s
, "connect ", 8, 0);
598 send(s
, FWhost
, strlen(FWhost
), 0);
601 sprintf(buf
, " %d\n", FWport
);
602 send (s
, buf
, strlen(buf
), 0);
607 return "Protocol initialisation error";
609 if (WSAAsyncSelect (s
, hwnd
, WM_NETEVENT
, FD_READ
| FD_CLOSE
) == SOCKET_ERROR
)
610 switch (WSAGetLastError()) {
611 case WSAENETDOWN
: return "Network is down";
612 default: return "WSAAsyncSelect(): unknown error";
619 * Process a WM_NETEVENT message. Will return 0 if the connection
620 * has closed, or <0 for a socket error.
622 static int ssh_msg (WPARAM wParam
, LPARAM lParam
) {
626 if (s
== INVALID_SOCKET
) /* how the hell did we get here?! */
629 if (WSAGETSELECTERROR(lParam
) != 0)
630 return -WSAGETSELECTERROR(lParam
);
632 switch (WSAGETSELECTEVENT(lParam
)) {
634 ret
= recv(s
, buf
, sizeof(buf
), 0);
635 if (ret
< 0 && WSAGetLastError() == WSAEWOULDBLOCK
)
637 if (ret
< 0) /* any _other_ error */
638 return -10000-WSAGetLastError();
641 return 0; /* can't happen, in theory */
643 ssh_gotdata (buf
, ret
);
649 return 1; /* shouldn't happen, but WTF */
653 * Called to send data down the Telnet connection.
655 static void ssh_send (char *buf
, int len
) {
656 if (s
== INVALID_SOCKET
)
659 ssh_protocol(buf
, len
, 0);
663 * Called to set the size of the window from Telnet's POV.
665 static void ssh_size(void) {
667 case SSH_STATE_BEFORE_SIZE
:
668 break; /* do nothing */
669 case SSH_STATE_INTERMED
:
670 size_needed
= TRUE
; /* buffer for later */
672 case SSH_STATE_SESSION
:
673 s_wrpkt_start(11, 16);
674 pktout
.body
[0] = (rows
>> 24) & 0xFF;
675 pktout
.body
[1] = (rows
>> 16) & 0xFF;
676 pktout
.body
[2] = (rows
>> 8) & 0xFF;
677 pktout
.body
[3] = rows
& 0xFF;
678 pktout
.body
[4] = (cols
>> 24) & 0xFF;
679 pktout
.body
[5] = (cols
>> 16) & 0xFF;
680 pktout
.body
[6] = (cols
>> 8) & 0xFF;
681 pktout
.body
[7] = cols
& 0xFF;
682 memset(pktout
.body
+8, 0, 8);
688 * (Send Telnet special codes)
690 static void ssh_special (Telnet_Special code
) {
694 Backend ssh_backend
= {