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 = {