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 int c = (unsigned char) *buf;
80 if (new_head != inbuf_reap) {
81 inbuf[inbuf_head] = *buf++;
82 inbuf_head = new_head;
96 static struct Packet pktin = { 0, 0, 0, NULL, 0 };
97 static struct Packet pktout = { 0, 0, 0, NULL, 0 };
99 static void ssh_protocol(unsigned char *in, int inlen, int ispkt);
100 static void ssh_size(void);
102 static void ssh_gotdata(unsigned char *data, int datalen) {
103 static long len, biglen, to_read;
104 static unsigned char c, *p;
106 static char padding[8];
107 static unsigned char word[4];
111 for (i = len = 0; i < 4; i++) {
114 len = (len << 8) + *data;
119 if (len == 0x52656d6f) { /* "Remo"te server has closed ... */
120 len = 0x300; /* big enough to carry to end */
128 len -= 5; /* type and CRC */
131 if (pktin.maxlen < biglen) {
132 pktin.maxlen = biglen;
133 pktin.data = (pktin.data == NULL ? malloc(biglen) :
134 realloc(pktin.data, biglen));
136 fatalbox("Out of memory");
139 p = pktin.data, to_read = biglen;
140 while (to_read > 0) {
147 memcpy(p, data, chunk);
155 cipher->decrypt(pktin.data, biglen);
157 pktin.type = pktin.data[pad];
158 pktin.body = pktin.data+pad+1;
160 if (pktin.type == 36) { /* SSH_MSG_DEBUG */
163 ssh_protocol(NULL, 0, 1);
168 static void s_wrpkt_start(int type, int len) {
171 len += 5; /* type and CRC */
175 pktout.length = len-5;
176 if (pktout.maxlen < biglen) {
177 pktout.maxlen = biglen;
178 pktout.data = (pktout.data == NULL ? malloc(biglen+4) :
179 realloc(pktout.data, biglen+4));
181 fatalbox("Out of memory");
185 pktout.body = pktout.data+4+pad+1;
188 static void s_wrpkt(void) {
189 int pad, len, biglen, i;
192 len = pktout.length + 5; /* type and CRC */
196 pktout.body[-1] = pktout.type;
197 for (i=0; i<pad; i++)
198 pktout.data[i+4] = random_byte();
199 crc = crc32(pktout.data+4, biglen-4);
201 pktout.data[biglen+0] = (unsigned char) ((crc >> 24) & 0xFF);
202 pktout.data[biglen+1] = (unsigned char) ((crc >> 16) & 0xFF);
203 pktout.data[biglen+2] = (unsigned char) ((crc >> 8) & 0xFF);
204 pktout.data[biglen+3] = (unsigned char) (crc & 0xFF);
206 pktout.data[0] = (len >> 24) & 0xFF;
207 pktout.data[1] = (len >> 16) & 0xFF;
208 pktout.data[2] = (len >> 8) & 0xFF;
209 pktout.data[3] = len & 0xFF;
212 cipher->encrypt(pktout.data+4, biglen);
214 s_write(pktout.data, biglen+4);
217 static int do_ssh_init(void) {
225 while (s_read(&c, 1) == 1) {
226 if (c == 'S' && i < 2) i++;
227 else if (c == 'S' && i == 2) i = 2;
228 else if (c == 'H' && i == 2) break;
232 if (s_read(&c,1) != 1 || c != 'S') return 0;
233 if (s_read(&c,1) != 1 || c != 'S') return 0;
234 if (s_read(&c,1) != 1 || c != 'H') return 0;
236 if (s_read(&c,1) != 1 || c != '-') return 0;
239 if (s_read(&c,1) != 1)
245 } else if (i < sizeof(version)-1)
252 sprintf(vstring, "SSH-%s-7.7.7\n",
253 (strcmp(version, "1.5") <= 0 ? version : "1.5"));
254 s_write(vstring, strlen(vstring));
258 static void ssh_protocol(unsigned char *in, int inlen, int ispkt) {
260 unsigned char session_id[16];
261 unsigned char *rsabuf, *keystr1, *keystr2;
262 unsigned char cookie[8];
263 struct RSAKey servkey, hostkey;
264 struct MD5Context md5c;
266 extern struct ssh_cipher ssh_3des;
276 fatalbox("Public key packet not received");
278 memcpy(cookie, pktin.body, 8);
282 i = makekey(pktin.body+8, &servkey, &keystr1);
284 j = makekey(pktin.body+8+i, &hostkey, &keystr2);
286 MD5Update(&md5c, keystr2, hostkey.bytes);
287 MD5Update(&md5c, keystr1, servkey.bytes);
288 MD5Update(&md5c, pktin.body, 8);
290 MD5Final(session_id, &md5c);
293 session_key[i] = random_byte();
295 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
297 rsabuf = malloc(len);
299 fatalbox("Out of memory");
301 verify_ssh_host_key(savedhost, &hostkey);
303 for (i=0; i<32; i++) {
304 rsabuf[i] = session_key[i];
306 rsabuf[i] ^= session_id[i];
309 if (hostkey.bytes > servkey.bytes) {
310 rsaencrypt(rsabuf, 32, &servkey);
311 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
313 rsaencrypt(rsabuf, 32, &hostkey);
314 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
317 s_wrpkt_start(3, len+15);
318 pktout.body[0] = 3; /* SSH_CIPHER_3DES */
319 memcpy(pktout.body+1, cookie, 8);
320 pktout.body[9] = (len*8) >> 8;
321 pktout.body[10] = (len*8) & 0xFF;
322 memcpy(pktout.body+11, rsabuf, len);
323 pktout.body[len+11] = pktout.body[len+12] = 0; /* protocol flags */
324 pktout.body[len+13] = pktout.body[len+14] = 0;
330 cipher->sesskey(session_key);
332 do { crReturnV; } while (!ispkt);
334 if (pktin.type != 14)
335 fatalbox("Encryption not successfully enabled");
339 static char username[100];
342 if (!*cfg.username) {
343 c_write("login as: ", 10);
345 do { crReturnV; } while (ispkt);
346 while (inlen--) switch (c = *in++) {
368 if (c >= ' ' && c <= '~' && pos < 40) {
376 username[strcspn(username, "\n\r")] = '\0';
379 strncpy(username, cfg.username, 99);
381 sprintf(stuff, "Sent username \"%s\".\r\n", username);
382 c_write(stuff, strlen(stuff));
384 s_wrpkt_start(4, 4+strlen(username));
385 pktout.body[0] = pktout.body[1] = pktout.body[2] = 0;
386 pktout.body[3] = strlen(username);
387 memcpy(pktout.body+4, username, strlen(username));
391 do { crReturnV; } while (!ispkt);
393 while (pktin.type == 15) {
394 static char password[100];
397 c_write("password: ", 10);
400 do { crReturnV; } while (ispkt);
401 while (inlen--) switch (c = *in++) {
418 if (c >= ' ' && c <= '~' && pos < 40)
424 s_wrpkt_start(9, 4+strlen(password));
425 pktout.body[0] = pktout.body[1] = pktout.body[2] = 0;
426 pktout.body[3] = strlen(password);
427 memcpy(pktout.body+4, password, strlen(password));
429 memset(password, 0, strlen(password));
430 do { crReturnV; } while (!ispkt);
431 if (pktin.type == 15) {
432 c_write("Access denied\r\n", 15);
433 } else if (pktin.type != 14) {
434 fatalbox("Strange packet received, type %d", pktin.type);
439 i = strlen(cfg.termtype);
440 s_wrpkt_start(10, i+5*4+1);
441 pktout.body[0] = (i >> 24) & 0xFF;
442 pktout.body[1] = (i >> 16) & 0xFF;
443 pktout.body[2] = (i >> 8) & 0xFF;
444 pktout.body[3] = i & 0xFF;
445 memcpy(pktout.body+4, cfg.termtype, i);
447 pktout.body[i++] = (rows >> 24) & 0xFF;
448 pktout.body[i++] = (rows >> 16) & 0xFF;
449 pktout.body[i++] = (rows >> 8) & 0xFF;
450 pktout.body[i++] = rows & 0xFF;
451 pktout.body[i++] = (cols >> 24) & 0xFF;
452 pktout.body[i++] = (cols >> 16) & 0xFF;
453 pktout.body[i++] = (cols >> 8) & 0xFF;
454 pktout.body[i++] = cols & 0xFF;
455 memset(pktout.body+i, 0, 9); /* 0 pixwidth, 0 pixheight, 0.b endofopt */
457 ssh_state = SSH_STATE_INTERMED;
458 do { crReturnV; } while (!ispkt);
459 if (pktin.type != 14 && pktin.type != 15) {
460 fatalbox("Protocol confusion");
461 } else if (pktin.type == 15) {
462 c_write("Server refused to allocate pty\r\n", 32);
466 s_wrpkt_start(12, 0);
469 ssh_state = SSH_STATE_SESSION;
476 if (pktin.type == 17 || pktin.type == 18) {
478 for (i = 0; i < 4; i++)
479 len = (len << 8) + pktin.body[i];
480 c_write(pktin.body+4, len);
481 } else if (pktin.type == 1) {
482 /* SSH_MSG_DISCONNECT */
483 ssh_state = SSH_STATE_CLOSED;
484 } else if (pktin.type == 14) {
485 /* SSH_MSG_SUCCESS: may be from EXEC_SHELL on some servers */
486 } else if (pktin.type == 15) {
487 /* SSH_MSG_FAILURE: may be from EXEC_SHELL on some servers
488 * if no pty is available or in other odd cases. Ignore */
489 } else if (pktin.type == 20) {
491 s_wrpkt_start(33, 0);
494 fatalbox("Strange packet received: type %d", pktin.type);
497 s_wrpkt_start(16, 4+inlen);
498 pktout.body[0] = (inlen >> 24) & 0xFF;
499 pktout.body[1] = (inlen >> 16) & 0xFF;
500 pktout.body[2] = (inlen >> 8) & 0xFF;
501 pktout.body[3] = inlen & 0xFF;
502 memcpy(pktout.body+4, in, inlen);
511 * Called to set up the connection. Will arrange for WM_NETEVENT
512 * messages to be passed to the specified window, whose window
513 * procedure should then call telnet_msg().
515 * Returns an error message, or NULL on success.
517 * Also places the canonical host name into `realhost'.
519 static char *ssh_init (HWND hwnd, char *host, int port, char **realhost) {
528 savedhost = malloc(1+strlen(host));
530 fatalbox("Out of memory");
531 strcpy(savedhost, host);
543 if ( (a = inet_addr(host)) == (unsigned long) INADDR_NONE) {
544 if ( (h = gethostbyname(host)) == NULL)
545 switch (WSAGetLastError()) {
546 case WSAENETDOWN: return "Network is down";
547 case WSAHOST_NOT_FOUND: case WSANO_DATA:
548 return "Host does not exist";
549 case WSATRY_AGAIN: return "Host not found";
550 default: return "gethostbyname: unknown error";
552 memcpy (&a, h->h_addr, sizeof(a));
553 *realhost = h->h_name;
562 port = 22; /* default ssh port */
567 s = socket(AF_INET, SOCK_STREAM, 0);
568 if (s == INVALID_SOCKET)
569 switch (WSAGetLastError()) {
570 case WSAENETDOWN: return "Network is down";
571 case WSAEAFNOSUPPORT: return "TCP/IP support not present";
572 default: return "socket(): unknown error";
576 * Bind to local address.
578 addr.sin_family = AF_INET;
579 addr.sin_addr.s_addr = htonl(INADDR_ANY);
580 addr.sin_port = htons(0);
581 if (bind (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
582 switch (WSAGetLastError()) {
583 case WSAENETDOWN: return "Network is down";
584 default: return "bind(): unknown error";
588 * Connect to remote address.
590 addr.sin_addr.s_addr = htonl(a);
591 addr.sin_port = htons((short)port);
592 if (connect (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
593 switch (WSAGetLastError()) {
594 case WSAENETDOWN: return "Network is down";
595 case WSAECONNREFUSED: return "Connection refused";
596 case WSAENETUNREACH: return "Network is unreachable";
597 case WSAEHOSTUNREACH: return "No route to host";
598 default: return "connect(): unknown error";
602 send(s, "connect ", 8, 0);
603 send(s, FWhost, strlen(FWhost), 0);
606 sprintf(buf, " %d\n", FWport);
607 send (s, buf, strlen(buf), 0);
612 return "Protocol initialisation error";
614 if (WSAAsyncSelect (s, hwnd, WM_NETEVENT, FD_READ | FD_CLOSE) == SOCKET_ERROR)
615 switch (WSAGetLastError()) {
616 case WSAENETDOWN: return "Network is down";
617 default: return "WSAAsyncSelect(): unknown error";
624 * Process a WM_NETEVENT message. Will return 0 if the connection
625 * has closed, or <0 for a socket error.
627 static int ssh_msg (WPARAM wParam, LPARAM lParam) {
631 if (s == INVALID_SOCKET) /* how the hell did we get here?! */
634 if (WSAGETSELECTERROR(lParam) != 0)
635 return -WSAGETSELECTERROR(lParam);
637 switch (WSAGETSELECTEVENT(lParam)) {
639 ret = recv(s, buf, sizeof(buf), 0);
640 if (ret < 0 && WSAGetLastError() == WSAEWOULDBLOCK)
642 if (ret < 0) /* any _other_ error */
643 return -10000-WSAGetLastError();
646 return 0; /* can't happen, in theory */
648 ssh_gotdata (buf, ret);
652 ssh_state = SSH_STATE_CLOSED;
655 return 1; /* shouldn't happen, but WTF */
659 * Called to send data down the Telnet connection.
661 static void ssh_send (char *buf, int len) {
662 if (s == INVALID_SOCKET)
665 ssh_protocol(buf, len, 0);
669 * Called to set the size of the window from Telnet's POV.
671 static void ssh_size(void) {
673 case SSH_STATE_BEFORE_SIZE:
674 case SSH_STATE_CLOSED:
675 break; /* do nothing */
676 case SSH_STATE_INTERMED:
677 size_needed = TRUE; /* buffer for later */
679 case SSH_STATE_SESSION:
681 s_wrpkt_start(11, 16);
682 pktout.body[0] = (rows >> 24) & 0xFF;
683 pktout.body[1] = (rows >> 16) & 0xFF;
684 pktout.body[2] = (rows >> 8) & 0xFF;
685 pktout.body[3] = rows & 0xFF;
686 pktout.body[4] = (cols >> 24) & 0xFF;
687 pktout.body[5] = (cols >> 16) & 0xFF;
688 pktout.body[6] = (cols >> 8) & 0xFF;
689 pktout.body[7] = cols & 0xFF;
690 memset(pktout.body+8, 0, 8);
697 * (Send Telnet special codes)
699 static void ssh_special (Telnet_Special code) {
703 Backend ssh_backend = {