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;
265 unsigned long supported_ciphers_mask;
268 extern struct ssh_cipher ssh_3des;
269 extern struct ssh_cipher ssh_blowfish;
279 fatalbox("Public key packet not received");
281 memcpy(cookie, pktin.body, 8);
285 i = makekey(pktin.body+8, &servkey, &keystr1);
287 j = makekey(pktin.body+8+i, &hostkey, &keystr2);
289 supported_ciphers_mask = (pktin.body[12+i+j] << 24) |
290 (pktin.body[13+i+j] << 16) |
291 (pktin.body[14+i+j] << 8) |
292 (pktin.body[15+i+j]);
294 MD5Update(&md5c, keystr2, hostkey.bytes);
295 MD5Update(&md5c, keystr1, servkey.bytes);
296 MD5Update(&md5c, pktin.body, 8);
298 MD5Final(session_id, &md5c);
301 session_key[i] = random_byte();
303 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
305 rsabuf = malloc(len);
307 fatalbox("Out of memory");
309 verify_ssh_host_key(savedhost, &hostkey);
311 for (i=0; i<32; i++) {
312 rsabuf[i] = session_key[i];
314 rsabuf[i] ^= session_id[i];
317 if (hostkey.bytes > servkey.bytes) {
318 rsaencrypt(rsabuf, 32, &servkey);
319 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
321 rsaencrypt(rsabuf, 32, &hostkey);
322 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
325 cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH :
327 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
328 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
329 cipher_type = SSH_CIPHER_3DES;
332 s_wrpkt_start(3, len+15);
333 pktout.body[0] = cipher_type;
334 memcpy(pktout.body+1, cookie, 8);
335 pktout.body[9] = (len*8) >> 8;
336 pktout.body[10] = (len*8) & 0xFF;
337 memcpy(pktout.body+11, rsabuf, len);
338 pktout.body[len+11] = pktout.body[len+12] = 0; /* protocol flags */
339 pktout.body[len+13] = pktout.body[len+14] = 0;
344 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish :
346 cipher->sesskey(session_key);
348 do { crReturnV; } while (!ispkt);
350 if (pktin.type != 14)
351 fatalbox("Encryption not successfully enabled");
355 static char username[100];
358 if (!*cfg.username) {
359 c_write("login as: ", 10);
361 do { crReturnV; } while (ispkt);
362 while (inlen--) switch (c = *in++) {
384 if (c >= ' ' && c <= '~' && pos < 40) {
392 username[strcspn(username, "\n\r")] = '\0';
395 strncpy(username, cfg.username, 99);
397 sprintf(stuff, "Sent username \"%s\".\r\n", username);
398 c_write(stuff, strlen(stuff));
400 s_wrpkt_start(4, 4+strlen(username));
401 pktout.body[0] = pktout.body[1] = pktout.body[2] = 0;
402 pktout.body[3] = strlen(username);
403 memcpy(pktout.body+4, username, strlen(username));
407 do { crReturnV; } while (!ispkt);
409 while (pktin.type == 15) {
410 static char password[100];
413 c_write("password: ", 10);
416 do { crReturnV; } while (ispkt);
417 while (inlen--) switch (c = *in++) {
434 if (c >= ' ' && c <= '~' && pos < 40)
440 s_wrpkt_start(9, 4+strlen(password));
441 pktout.body[0] = pktout.body[1] = pktout.body[2] = 0;
442 pktout.body[3] = strlen(password);
443 memcpy(pktout.body+4, password, strlen(password));
445 memset(password, 0, strlen(password));
446 do { crReturnV; } while (!ispkt);
447 if (pktin.type == 15) {
448 c_write("Access denied\r\n", 15);
449 } else if (pktin.type != 14) {
450 fatalbox("Strange packet received, type %d", pktin.type);
455 i = strlen(cfg.termtype);
456 s_wrpkt_start(10, i+5*4+1);
457 pktout.body[0] = (i >> 24) & 0xFF;
458 pktout.body[1] = (i >> 16) & 0xFF;
459 pktout.body[2] = (i >> 8) & 0xFF;
460 pktout.body[3] = i & 0xFF;
461 memcpy(pktout.body+4, cfg.termtype, i);
463 pktout.body[i++] = (rows >> 24) & 0xFF;
464 pktout.body[i++] = (rows >> 16) & 0xFF;
465 pktout.body[i++] = (rows >> 8) & 0xFF;
466 pktout.body[i++] = rows & 0xFF;
467 pktout.body[i++] = (cols >> 24) & 0xFF;
468 pktout.body[i++] = (cols >> 16) & 0xFF;
469 pktout.body[i++] = (cols >> 8) & 0xFF;
470 pktout.body[i++] = cols & 0xFF;
471 memset(pktout.body+i, 0, 9); /* 0 pixwidth, 0 pixheight, 0.b endofopt */
473 ssh_state = SSH_STATE_INTERMED;
474 do { crReturnV; } while (!ispkt);
475 if (pktin.type != 14 && pktin.type != 15) {
476 fatalbox("Protocol confusion");
477 } else if (pktin.type == 15) {
478 c_write("Server refused to allocate pty\r\n", 32);
482 s_wrpkt_start(12, 0);
485 ssh_state = SSH_STATE_SESSION;
492 if (pktin.type == 17 || pktin.type == 18) {
494 for (i = 0; i < 4; i++)
495 len = (len << 8) + pktin.body[i];
496 c_write(pktin.body+4, len);
497 } else if (pktin.type == 1) {
498 /* SSH_MSG_DISCONNECT */
499 ssh_state = SSH_STATE_CLOSED;
500 } else if (pktin.type == 14) {
501 /* SSH_MSG_SUCCESS: may be from EXEC_SHELL on some servers */
502 } else if (pktin.type == 15) {
503 /* SSH_MSG_FAILURE: may be from EXEC_SHELL on some servers
504 * if no pty is available or in other odd cases. Ignore */
505 } else if (pktin.type == 20) {
507 s_wrpkt_start(33, 0);
510 fatalbox("Strange packet received: type %d", pktin.type);
513 s_wrpkt_start(16, 4+inlen);
514 pktout.body[0] = (inlen >> 24) & 0xFF;
515 pktout.body[1] = (inlen >> 16) & 0xFF;
516 pktout.body[2] = (inlen >> 8) & 0xFF;
517 pktout.body[3] = inlen & 0xFF;
518 memcpy(pktout.body+4, in, inlen);
527 * Called to set up the connection. Will arrange for WM_NETEVENT
528 * messages to be passed to the specified window, whose window
529 * procedure should then call telnet_msg().
531 * Returns an error message, or NULL on success.
533 * Also places the canonical host name into `realhost'.
535 static char *ssh_init (HWND hwnd, char *host, int port, char **realhost) {
544 savedhost = malloc(1+strlen(host));
546 fatalbox("Out of memory");
547 strcpy(savedhost, host);
559 if ( (a = inet_addr(host)) == (unsigned long) INADDR_NONE) {
560 if ( (h = gethostbyname(host)) == NULL)
561 switch (WSAGetLastError()) {
562 case WSAENETDOWN: return "Network is down";
563 case WSAHOST_NOT_FOUND: case WSANO_DATA:
564 return "Host does not exist";
565 case WSATRY_AGAIN: return "Host not found";
566 default: return "gethostbyname: unknown error";
568 memcpy (&a, h->h_addr, sizeof(a));
569 *realhost = h->h_name;
578 port = 22; /* default ssh port */
583 s = socket(AF_INET, SOCK_STREAM, 0);
584 if (s == INVALID_SOCKET)
585 switch (WSAGetLastError()) {
586 case WSAENETDOWN: return "Network is down";
587 case WSAEAFNOSUPPORT: return "TCP/IP support not present";
588 default: return "socket(): unknown error";
592 * Bind to local address.
594 addr.sin_family = AF_INET;
595 addr.sin_addr.s_addr = htonl(INADDR_ANY);
596 addr.sin_port = htons(0);
597 if (bind (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
598 switch (WSAGetLastError()) {
599 case WSAENETDOWN: return "Network is down";
600 default: return "bind(): unknown error";
604 * Connect to remote address.
606 addr.sin_addr.s_addr = htonl(a);
607 addr.sin_port = htons((short)port);
608 if (connect (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
609 switch (WSAGetLastError()) {
610 case WSAENETDOWN: return "Network is down";
611 case WSAECONNREFUSED: return "Connection refused";
612 case WSAENETUNREACH: return "Network is unreachable";
613 case WSAEHOSTUNREACH: return "No route to host";
614 default: return "connect(): unknown error";
618 send(s, "connect ", 8, 0);
619 send(s, FWhost, strlen(FWhost), 0);
622 sprintf(buf, " %d\n", FWport);
623 send (s, buf, strlen(buf), 0);
628 return "Protocol initialisation error";
630 if (WSAAsyncSelect (s, hwnd, WM_NETEVENT, FD_READ | FD_CLOSE) == SOCKET_ERROR)
631 switch (WSAGetLastError()) {
632 case WSAENETDOWN: return "Network is down";
633 default: return "WSAAsyncSelect(): unknown error";
640 * Process a WM_NETEVENT message. Will return 0 if the connection
641 * has closed, or <0 for a socket error.
643 static int ssh_msg (WPARAM wParam, LPARAM lParam) {
647 if (s == INVALID_SOCKET) /* how the hell did we get here?! */
650 if (WSAGETSELECTERROR(lParam) != 0)
651 return -WSAGETSELECTERROR(lParam);
653 switch (WSAGETSELECTEVENT(lParam)) {
655 ret = recv(s, buf, sizeof(buf), 0);
656 if (ret < 0 && WSAGetLastError() == WSAEWOULDBLOCK)
658 if (ret < 0) /* any _other_ error */
659 return -10000-WSAGetLastError();
662 return 0; /* can't happen, in theory */
664 ssh_gotdata (buf, ret);
668 ssh_state = SSH_STATE_CLOSED;
671 return 1; /* shouldn't happen, but WTF */
675 * Called to send data down the Telnet connection.
677 static void ssh_send (char *buf, int len) {
678 if (s == INVALID_SOCKET)
681 ssh_protocol(buf, len, 0);
685 * Called to set the size of the window from Telnet's POV.
687 static void ssh_size(void) {
689 case SSH_STATE_BEFORE_SIZE:
690 case SSH_STATE_CLOSED:
691 break; /* do nothing */
692 case SSH_STATE_INTERMED:
693 size_needed = TRUE; /* buffer for later */
695 case SSH_STATE_SESSION:
697 s_wrpkt_start(11, 16);
698 pktout.body[0] = (rows >> 24) & 0xFF;
699 pktout.body[1] = (rows >> 16) & 0xFF;
700 pktout.body[2] = (rows >> 8) & 0xFF;
701 pktout.body[3] = rows & 0xFF;
702 pktout.body[4] = (cols >> 24) & 0xFF;
703 pktout.body[5] = (cols >> 16) & 0xFF;
704 pktout.body[6] = (cols >> 8) & 0xFF;
705 pktout.body[7] = cols & 0xFF;
706 memset(pktout.body+8, 0, 8);
713 * (Send Telnet special codes)
715 static void ssh_special (Telnet_Special code) {
719 Backend ssh_backend = {